825 results on '"Lars Berglund"'
Search Results
152. Nanostructural Effects in High Cellulose Content Thermoplastic Nanocomposites with a Covalently Grafted Cellulose-Poly(methyl methacrylate) Interface
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Farhan Ansari, Assya Boujemaoui, and Lars Berglund
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Materials science ,Thermoplastic ,Polymers and Plastics ,Polymer nanocomposite ,Nanofibers ,Bioengineering ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Nanocomposites ,Biomaterials ,chemistry.chemical_compound ,Materials Chemistry ,Polymethyl Methacrylate ,Cellulose ,Methyl methacrylate ,chemistry.chemical_classification ,Nanocomposite ,Polymer ,021001 nanoscience & nanotechnology ,Poly(methyl methacrylate) ,0104 chemical sciences ,Monomer ,chemistry ,Chemical engineering ,visual_art ,visual_art.visual_art_medium ,0210 nano-technology - Abstract
A critical aspect in materials design of polymer nanocomposites is the nature of the nanoparticle/polymer interface. The present study investigates the effect of manipulation of the interface between cellulose nanofibrils (CNF) and poly(methyl methacrylate) (PMMA) on the optical, thermal, and mechanical properties of the corresponding nanocomposites. The CNF/PMMA interface is altered with a minimum of changes in material composition so that interface effects can be analyzed. The hydroxyl-rich surface of CNF fibrils is exploited to modify the CNF surface via an epoxide-hydroxyl reaction. CNF/PMMA nanocomposites are then prepared with high CNF content (∼38 wt %) using an approach where a porous CNF mat is impregnated with monomer or polymer. The nanocomposite interface is controlled by either providing PMMA grafts from the modified CNF surface or by solvent-assisted diffusion of PMMA into a CNF network (native and modified). The high content of CNF fibrils of ∼6 nm diameter leads to a strong interface and polymer matrix distribution effects. Moisture uptake and mechanical properties are measured at different relative humidity conditions. The nanocomposites with PMMA molecules grafted to cellulose exhibited much higher optical transparency, thermal stability, and hygro-mechanical properties than the control samples. The present modification and preparation strategies are versatile and may be used for cellulose nanocomposites of other compositions, architectures, properties, and functionalities.
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- 2018
153. Polymer photonics and nano-materials for optical communication
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Yuanyuan Li, Aleksandrs Marinins, Aleksejs Udalcovs, Oskars Ozolins, Elena Vasileva, Max Yan, Lars Berglund, Sergei Popov, and Ilya Sychugov
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chemistry.chemical_classification ,Materials science ,business.industry ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,Optical communication ,Physics::Optics ,Nanotechnology ,Optical polarization ,02 engineering and technology ,Polymer ,Laser ,Nanomaterials ,law.invention ,020210 optoelectronics & photonics ,chemistry ,law ,Compatibility (mechanics) ,0202 electrical engineering, electronic engineering, information engineering ,Photonics ,Polymer waveguide ,business - Abstract
Polymer materials offer process compatibility, design flexibility, and low cost technology as a multi-functional platform for optical communication and photonics applications. Design and thermal reflowing technology of low loss polymer waveguides, as well as demonstration of transparent wood laser are presented in this paper.
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- 2018
154. Non-HDL-C levels and residual cardiovascular risk: Do population-specific precision approaches offer any advantages?
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Byambaa Enkhmaa, Lars Berglund, and Nishant Prakash
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Adult ,Male ,HDL ,Health Status ,Clinical Decision-Making ,Clinical Sciences ,Comorbidity ,Cardiorespiratory Medicine and Haematology ,030204 cardiovascular system & hematology ,Residual ,Bioinformatics ,Risk Assessment ,Article ,03 medical and health sciences ,0302 clinical medicine ,HDL cholesterol ,Risk Factors ,Population specific ,Medicine ,Humans ,Longitudinal Studies ,030212 general & internal medicine ,Aged ,Dyslipidemias ,business.industry ,Anticholesteremic Agents ,Populations ,Non hdl c ,Cholesterol, HDL ,Cholesterol, LDL ,Middle Aged ,Atherosclerosis ,Cardiovascular risk ,Lipids ,Good Health and Well Being ,Treatment Outcome ,Cholesterol ,Cardiovascular System & Hematology ,Cardiovascular Diseases ,Practice Guidelines as Topic ,Female ,Cardiology and Cardiovascular Medicine ,business ,Goals ,Biomarkers ,Brazil - Abstract
Non-high-density lipoprotein cholesterol (non-HDL-C) goals are defined as 30 mg/dL (0.78 mmol/L) higher than the respective low-density lipoprotein cholesterol (LDL-C) goals. This definition, however, do not consider the population distribution of non-HDL-C, which could represent a more appropriate individual goal when both markers are discordant. The aim of this study is to establish non-HDL-C goals at the same population percentiles of LDL-C.Non-HDL-C values were assigned at the same percentiles correspondent to the LDL-C treatment goals for 14,837 participants from the Longitudinal Study of Adult Health (ELSA-Brasil) with triglycerides levels ≤ 400 mg/dL (4.52 mmol/L). We also assessed the frequency of reclassification, defined as the number of subjects with LDL-C levels in the recommended therapeutic category, but with non-HDL-C levels above or below the category.The non-HDL-C values, based on correspondent LDL-C population percentiles, were 92 (2.38), 122 (3.16), 156 (4.04), 191 (4.95), and 223 mg/dL (5.78 mmol/L). Among participants with LDL-C70 mg/dL (1.81 mmol/L), 22.8% were reclassified in a higher category according to the guidelines-based non-HDL-C cut-off and 30.1% according to the population percentile-based cut-off; 25.6% and 64.1%, respectively, if triglycerides concurrently 150-199 mg/dL (1.69-2.25 mmol/L).Our results demonstrated that non-HDL-C percentiles-based goals were up to 8 mg/dL (0.21 mmol/L) lower than the guidelines recommended goal and had a profound impact on the reclassification of participants, notably when LDL-C was100 mg/dL (2.56 mmol/L), the treatment goal for high risk patients. Therefore, non-HDL-C goals should be changed for reduction of residual risk.
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- 2018
155. Construction and validation of a prediction model to minimize twin rates at preserved high live birth rates after IVF
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Thomas Brodin, Lars Berglund, Johanna Tilly, Nermin Hadziosmanovic, Katarina Kebbon Vaegter, and Jan Holte
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Adult ,medicine.medical_specialty ,Offspring ,Perinatal outcome ,Fertilization in Vitro ,Biology ,Embryo Culture Techniques ,Pregnancy ,Transfer (computing) ,medicine ,Single Embryo Transfer ,Humans ,Blastocyst ,Birth Rate ,Obstetrics ,Obstetrics and Gynecology ,Embryo ,Embryo culture ,Models, Theoretical ,medicine.disease ,medicine.anatomical_structure ,Reproductive Medicine ,Pregnancy, Twin ,Female ,Live birth ,Live Birth ,Developmental Biology - Abstract
Research question Elective single-embryo transfer (eSET) at blastocyst stage is widely used to reduce the frequency of multiple pregnancies after IVF. There are, however, concerns about increased risks for the offspring with prolonged embryo culture. Is it possible to select embryos for transfer at the early cleavage stage and still achieve low twin rates at preserved high live birth rates? Design A prediction model (PM) was developed to optimize eSET based on variables known 2 days after oocyte retrieval (fresh day 2 embryo transfers; double-embryo transfers 1999–2002 (n=2846) and SET 1999–2003 (n=945); n total=3791). Seventy-five variables were analysed for association with pregnancy chance and twin risk and combined for PM construction. This PM was validated in 2004–2016 including frozen-thawed transfers (FET), to compare cumulative live birth rate (CLBR) and twin rate before (1999–2002 fresh embryo transfers plus FET from the same oocyte retrievals until the end of 2007, n=3495) and after (2004–2011 fresh embryo transfers plus FET from the same oocyte retrievals until the end of 2016, n=11195) implementing the model. Results The PM was constructed from four independent variables: female age, embryo score, ovarian sensitivity and treatment history. The calibration, i.e. the fit of observed versus predicted results, was excellent both at construction and at validation. Without compromising CLBR, twin rate was reduced from 25.2% to 3.8%, accompanied by profound improvements in perinatal outcome. Conclusion The results provide the first successful construction, validation and impact analysis of a day 2 transfer PM to reduce multiple pregnancies.
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- 2018
156. Well‐dispersed polyurethane/cellulose nanocrystal nanocomposites synthesized by a solvent‐free procedure in bulk
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Lars Berglund, Vojtěch Kupka, Qi Zhou, Hu Tang, Lucy Vojtová, Josef Jančář, Miroslav Šlouf, and Farhan Ansari
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Materials science ,Solvent free ,Nanocomposite ,Polymers and Plastics ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Amorphous solid ,Matrix (chemical analysis) ,chemistry.chemical_compound ,Cellulose nanocrystals ,chemistry ,Nanocrystal ,Materials Chemistry ,Ceramics and Composites ,Cellulose ,Composite material ,0210 nano-technology ,Polyurethane - Abstract
Polyurethane (PU) nanocomposites utilizing cellulose nanocrystals (CNCs) as nanofiller and amorphous PU matrix were synthesized in a novel solvent-free bulk process. A green nanofiller, CNCs, was s ...
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- 2018
157. The utility of coagulation activity for prediction of risk of mortality and cardiovascular events in guideline-treated myocardial infarction patients
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Agneta Siegbahn, Lars Berglund, Bertil Lindahl, Jonas Oldgren, and Christina Christersson
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Adult ,Male ,Risk ,medicine.medical_specialty ,Myocardial Infarction ,lcsh:Medicine ,heart failure ,Hemorrhage ,030204 cardiovascular system & hematology ,Fibrin Fibrinogen Degradation Products ,03 medical and health sciences ,0302 clinical medicine ,Thrombin ,Internal medicine ,D-dimer ,medicine ,Risk of mortality ,Humans ,Cardiac and Cardiovascular Systems ,030212 general & internal medicine ,Myocardial infarction ,Aged ,Aged, 80 and over ,Kardiologi ,business.industry ,lcsh:R ,General Medicine ,Guideline ,Original Articles ,Middle Aged ,thromboembolism ,medicine.disease ,thrombin ,Stroke ,myocardial infarction ,Coagulation ,Heart failure ,Cardiology ,Female ,business ,medicine.drug - Abstract
Background: Despite improved treatment of myocardial infarction (MI), real-world patients still suffer substantial risk for subsequent cardiovascular events. Little is known about coagulation activity shortly after MI and whether coagulation activity markers may identify patients at increased risk despite contemporary treatment. Objective: To evaluate D-dimer concentration and thrombin generation potential shortly after discharge after MI and evaluate if these markers could predict the risk of future cardiovascular and bleeding events. Methods: Unselected MI patients (n = 421) were included in the observational REBUS study (NCT01102933) and followed for two years. D-dimer concentrations, thrombin peak, and endogenous thrombin potential (ETP) were analyzed at inclusion (3–5 days after MI) and at early follow-up (after 2–3 weeks). Results: Seventy-five patients (17.8%) experienced the composite endpoint (all-cause death, MI, congestive heart failure, or all-cause stroke), and 31 patients (7.4%) experienced a clinically relevant bleeding event. D-dimer concentrations at early follow-up were associated with the composite endpoint (HR [per SD increase] 1.51 [95% CI 1.22–1.87]) and with clinically relevant bleeding (HR [per SD increase] 1.80 [95% CI 1.32–2.44]). Thrombin generation potential was not significantly associated with either the composite endpoint or with clinically relevant bleeding. Higher thrombin peak and ETP at early follow-up were both inversely associated with stroke (HR [per SD increase] 0.50 [95% CI 0.30–0.81] and 0.43 [95% CI 0.22–0.83], respectively). Conclusion: In unselected MI patients treated according to contemporary guidelines, D-dimer measurements may identify patients at increased risk of new cardiovascular and bleeding events. The inverse association of thrombin generation potential and risk of stroke has to be further investigated.
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- 2018
158. Prevalence and consequences of injuries in powerlifting : a cross-sectional study
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Kajsa Gilenstam, Lars Berglund, Edit Strömbäck, and Ulrika Aasa
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medicine.medical_specialty ,sports injury ,Sports injury ,Cross-sectional study ,education ,Squat ,Bench press ,Article ,03 medical and health sciences ,0302 clinical medicine ,Övrig annan medicin och hälsovetenskap ,Medicine ,risk factors ,Orthopedics and Sports Medicine ,Sjukgymnastik ,Physiotherapy ,low back pain ,Sport and Fitness Sciences ,030222 orthopedics ,business.industry ,Idrottsvetenskap ,Resistance training ,030229 sport sciences ,Other Medical Sciences not elsewhere specified ,Physical therapy ,resistance training ,business - Abstract
Background:Powerlifting consists of the squat, bench press, and dead lift, and extreme loads are lifted during training and competitions. Previous studies, which have defined an injury as an event that causes an interruption in training or competitions, have reported a relatively low frequency of powerlifting injuries (1.0-4.4 injuries/1000 hours of training). No previous study has investigated the prevalence of injuries, defined as a condition of pain or impairment of bodily function that affects powerlifters’ training, in a balanced sample of men and women, and no studies have established possible risk factors for an injury.Purpose:To investigate the prevalence, localization, and characterization of injuries among Swedish subelite classic powerlifters, with an emphasis on differences between men and women, and to investigate whether training and lifestyle factors are associated with an injury.Study Design:Cross-sectional study; Level of evidence, 3.Methods:A total of 53 female and 51 male Swedish subelite powerlifters answered an online questionnaire including questions about background characteristics, training habits, and lifestyle factors. The main part of the questionnaire included questions about injuries and their consequences. An injury was defined as a condition of pain or impairment of bodily function that affects powerlifters’ training.Results:Seventy percent (73/104) of participants were currently injured, and 87% (83/95) had experienced an injury within the past 12 months. The lumbopelvic region, shoulder, and hip were the most commonly injured areas for both sexes. Women experienced a significantly greater frequency of injuries in the neck and thoracic region than men. Injuries seemed to occur during training, although only 16% (11/70) of those currently injured had to completely refrain from training. Training frequency, greater personal best in the dead lift, injury onset during bench-press and dead-lift training, use of straps, alcohol consumption, and dietary issues were associated with current injuries.Conclusion:Injuries are very common in subelite powerlifters. Men and women report similar injury frequencies but different anatomic locations. These injuries do not prevent powerlifters from training and competing, but they may change the content of training sessions. Why powerlifters develop injuries is still unclear; however, it is likely that the management of training loads and optimization of the lifting technique during the squat, bench press, and dead lift are of importance.
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- 2018
159. The use of a pilot-scale continuous paper process for fire retardant cellulose-kaolinite nanocomposites
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Daniele Oliveira Castro, Lars Wågberg, Lilian Medina, Zoheb Karim, Daniel Söderberg, Federico Carosio, Lars Berglund, J. O Häggström, and Anna Svedberg
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Materials science ,Mechanical properties ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Nanocellulose ,chemistry.chemical_compound ,Engineering (all) ,Kaolinite ,Cellulose ,Composite material ,Nanocomposite ,General Engineering ,Pilot scale ,021001 nanoscience & nanotechnology ,Hybrid ,0104 chemical sciences ,chemistry ,Microfibrillated cellulose ,Scientific method ,Ceramics and Composites ,Biocomposite ,0210 nano-technology ,Fire retardant - Abstract
Nanostructured materials are difficult to prepare rapidly and at large scale. Melt-processed polymer-clay nanocomposites are an exception, but the clay content is typically below 5 wt%. An approach ...
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- 2018
160. Effects of sauna bath on heart failure : A systematic review and meta-analysis
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Miikka Källström, Tomoko Ichiki, Lars Berglund, Jari A. Laukkanen, Inga Soveri, Jonas Oldgren, Hans Hägglund, Mark Timmerman, and Chuwa Tei
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Cardiac function curve ,Male ,medicine.medical_specialty ,Infrared Rays ,saunominen ,heart failure ,Review ,030204 cardiovascular system & hematology ,Cochrane Library ,sydämen vajaatoiminta ,Ventricular Function, Left ,Steam Bath ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,Waon therapy ,terveysvaikutukset ,Natriuretic Peptide, Brain ,medicine ,Infrared sauna ,Humans ,Cardiac and Cardiovascular Systems ,030212 general & internal medicine ,Aged ,Heart Failure ,Ejection fraction ,Kardiologi ,business.industry ,meta-analyysi ,Stroke Volume ,General Medicine ,architecture.style ,Recovery of Function ,Middle Aged ,medicine.disease ,Blood pressure ,Treatment Outcome ,architecture ,Heart failure ,Finnish Sauna ,Cardiology ,sydän- ja verisuonitaudit ,sauna bath ,Female ,Cardiology and Cardiovascular Medicine ,business ,Biomarkers - Abstract
Background: Sauna bath has potential as a lifestyle treatment modality for heart failure (HF). It is important to analyze the current evidence to help suggest paths of future study and potential for clinical application. Hypothesis: Sauna bath has a positive effect on HF patients. Methods: PubMed, Cochrane Library, and CINAHL databases were searched to identify randomized and nonrandomized controlled studies to compare effects of sauna bath with no sauna bath. Studies were searched for both infrared sauna bath and Finnish sauna bath. The strength of evidence was rated using a modified GRADE approach. Out of 1444 studies, nine met the inclusion criteria and were included in this review. Seven of these nine studies were included in the meta‐analysis. Only studies with infrared sauna bath met the inclusion criteria. Results: In the meta‐analysis, exposure to an infrared sauna bath in 60°C for 15 minutes, followed by a 30‐minute rest in warm environment, five times a week for 2 to 4 weeks, was associated with a significant reduction in B‐type natriuretic peptide, cardiothoracic ratio, and an improvement in left‐ventricular ejection fraction. There was no significant effect on left‐ventricular end‐diastolic diameter, left atrial diameter, systolic blood pressure, or diastolic blood pressure. The strength of evidence varied from moderate to insufficient. Conclusion: Infrared sauna bath was associated with short‐term improvement in cardiac function. More evidence is needed about long‐term effects of sauna bath and the effects of a Finnish sauna on cardiovascular health among patients with HF or other cardiovascular diseases. peerReviewed
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- 2018
161. Light Scattering by Structurally Anisotropic Media : A Benchmark with Transparent Wood
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Yuanyuan Li, Elena Vasileva, Ilya Sychugov, Lars Berglund, Max Yan, Sergei Popov, and Hui Chen
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Materials science ,Atom and Molecular Physics and Optics ,Optical transmittance ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Light scattering ,Nanocellulose ,transparent wood ,Composite material ,Anisotropy ,nanocellulose ,biocomposites ,anisotropic scattering ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,Anisotropic scattering ,hierarchical structure ,Benchmark (computing) ,Atom- och molekylfysik och optik ,Biocomposite ,0210 nano-technology ,Den kondenserade materiens fysik - Abstract
Transparent wood (TW) is a biocomposite material with hierarchical structure, which exhibits high optical transmittance and anisotropic light scattering. Here, the relation between anisotropic scattering and the internal structure of transparent wood is experimentally studied and the dependence of scattering anisotropy on material thickness, which characterizes the fraction of ballistic photons in the propagating light, is shown. The limitations of the conven-tional haze, as it is implemented to isotropic materials, are discussed, and a modified characteristic parameter of light scattering—the degree of aniso-tropic scattering is defined. This parameter together with the transport mean free path value is more practical and convenient for characterization of the material scattering properties. It is believed that the generic routine described in this paper can be applied for scattering characterization and comparison of other TW materials of either different thickness, optical quality or based on various wood species. QC 20181126
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- 2018
162. Optically Transparent Wood: Recent Progress, Opportunities, and Challenges
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Yuanyuan Li, Elena Vasileva, Ilya Sychugov, Sergei Popov, Lars Berglund
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- 2018
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163. A comparison between micro- and nanocellulose-filled composite adhesives for oil paintings restoration
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Flavio Deflorian, Annalisa Cataldi, Lars Berglund, and Alessandro Pegoretti
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Thermoplastic ,Materials science ,Composite number ,Mechanical properties ,02 engineering and technology ,Cellulose, Nanocomposites, Mechanical properties, Adhesion, Cultural heritage ,Nanocomposites ,Nanocellulose ,Materials Chemistry ,Composite material ,Cellulose ,Elastic modulus ,chemistry.chemical_classification ,Nanocomposite ,020502 materials ,Mechanical Engineering ,021001 nanoscience & nanotechnology ,Casting ,0205 materials engineering ,chemistry ,Mechanics of Materials ,Adhesion ,Cultural heritage ,Ceramics and Composites ,Adhesive ,0210 nano-technology ,Glass transition - Abstract
Cellulose nanocrystals (CNC) and microcrystals (CMC) were selected as reinforcing fillers for poly(2-ethyl-2-oxazoline), a water-soluble thermoplastic adhesive widely used in the restoration of oil paintings. Thin composite films containing 5, 10, and 30 wt% of CNC or CMC were produced by solution mixing and casting. UV-vis spectroscopy showed how CNC preserved the adhesive transparency even at the highest CNC content, while for CMC, a progressive loss of transparency was observed. Thermal analysis evidenced a progressive increase of the glass transition temperature of the polymer matrix induced by CNC, while no effects were observed for CMC. Both micro- and nanocellulose were able to improve the elastic modulus and reduce the thermal expansion coefficient and creep compliance of the adhesive, with effects more pronounced for CNC nanoparticles. Finally, single-lap shear test on bonded ancient oil painting substrates confirmed the improved dimensional stability of the joint imparted by CNC in the a...
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- 2015
164. Strong reinforcing effects from galactoglucomannan hemicellulose on mechanical behavior of wet cellulose nanofiber gels
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Kasinee Prakobna, Victor Kisonen, Chunlin Xu, and Lars Berglund
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Materials science ,Nanocomposite ,Mechanical Engineering ,Cellulose binding ,Cellulose microfibril ,chemistry.chemical_compound ,chemistry ,Mechanics of Materials ,Wet strength ,Nanofiber ,General Materials Science ,Hemicellulose ,Cellulose ,Composite material ,Galactoglucomannan - Abstract
Softwood hemicelluloses could potentially be combined with cellulose and used in packaging materials. In the present study, galactoglucomannan (GGM) is adsorbed to wood cellulose nanofibers (CNF) and filtered and dried or hot-pressed to form nanocomposite films. The CNF/GGM fibril diameters are characterized by AFM, and the colloidal behavior by dynamic light scattering. Mechanical properties are measured in uniaxial tension for wet gels, dried films, and hot-pressed films. The role of GGM is particularly important for the wet gels. The wet gels of CNF/GGM exhibit remarkable improvement in mechanical properties. FE-SEM fractography and moisture sorption studies are carried out to interpret the results for hygromechanical properties. The present study shows that GGM may find use as a molecular scale cellulose binding agent, causing little sacrifice in mechanical properties and improving wet strength.
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- 2015
165. Bright white light therapy in depression: A critical review of the evidence
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Lisa Ekselius, Lars Berglund, Björn Mårtensson, and Agneta Pettersson
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Light therapy ,Depressive Disorder ,medicine.medical_treatment ,Seasonal Affective Disorder ,PsycINFO ,Phototherapy ,Checklist ,law.invention ,Psychiatry and Mental health ,Clinical Psychology ,Treatment Outcome ,Randomized controlled trial ,law ,Rating scale ,Strictly standardized mean difference ,Statistical significance ,medicine ,Humans ,Psychology ,Depression (differential diagnoses) ,Clinical psychology - Abstract
Background Light therapy is an accepted treatment option, at least for seasonal affective disorder (SAD). Our aim was to critically evaluate treatment effects of bright white light (BWL) on the depressive symptoms in both SAD and non-seasonal depression. Methods The systematic review was performed according to the PRISMA guidelines. PubMed, Embase, and PsycINFO were searched (December 1974 through June 2014) for randomized controlled trials published in peer-reviewed journals. Study quality was assessed with a checklist developed by the Swedish Council on Technology Assessment in Health Care. Only studies with high or medium quality were used in the meta-analyses. Results Eight studies of SAD and two studies of non-seasonal depression met inclusion and quality criteria. Effects on SAD were estimated in two meta-analyses. In the first, week by week, BWL reached statistical significance only at two and three weeks of treatment (Standardized Mean Difference, SMD: −0.50 (−CI 0.94, −0.05); −0.31 (−0.59, −0.03) respectively). The second meta-analysis, of endpoint data only, showed a SMD of −0.54 (CI: −0.95, −0.13), which indicates an advantage for BWL. No meta-analysis was performed for non-seasonal depression due to heterogeneity between studies. Limitations This analysis is restricted to short-term effects of BWL measured as mean changes in scores derived from SIGH-SAD, SIGH-SAD self-report, or HDRS rating scales. Conclusions Most studies of BWL have considerable methodological problems, and the results of published meta-analyses are highly dependent on the study selection. Even though quality criteria are introduced in the selection procedures of studies, when the results are carefully scrutinized, the evidence is not unequivocal.
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- 2015
166. Biocomposites from Natural Rubber: Synergistic Effects of Functionalized Cellulose Nanocrystals as Both Reinforcing and Cross-Linking Agents via Free-Radical Thiol–ene Chemistry
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Lars Berglund, Qi Zhou, Mauro Claudino, Bipinbal Parambath Kanoth, and Mats Johansson
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Stress (mechanics) ,Cellulose nanocrystals ,Nanocomposite ,Materials science ,Natural rubber ,Chemical engineering ,visual_art ,Polymer chemistry ,visual_art.visual_art_medium ,General Materials Science ,Thiol ene chemistry - Abstract
Natural rubber/cellulose nanocrystals (NR/CNCs) form true biocomposites from renewable resources and are demonstrated to show significantly improved thermo-mechanical properties and reduced stress-softening. The nanocomposites were prepared from chemically functionalized CNCs bearing thiols. CNCs served as both reinforcing and cross-linking agents in the NR matrix, and the study was designed to prove the cross-linking function of modified CNCs. CNCs were prepared from cotton, and the cross-linkable mercapto-groups were introduced onto the surface of CNCs by esterification. Nanocomposite films were prepared by dispersing the modified CNCs (m-CNCs) in NR matrix by solution casting. The cross-links at the filler-matrix (m-CNCs-NR) interface were generated by photochemically initiated thiol-ene reactions as monitored by real-time FTIR analysis. The synergistic effects of reinforcement and chemical cross-linking at the m-CNCs-NR interface on structure, thermo-mechanical, and stress-softening behavior were investigated. Methods included field emission scanning electron microscopy (FE-SEM), swelling tests, dynamic mechanical analysis, and tensile tests. Compared to biocomposites from NR with unmodified CNCs, the NR/m-CNCs nanocomposites showed 2.4-fold increase in tensile strength, 1.6-fold increase in strain-to-failure, and 2.9-fold increase in work-of-fracture at 10 wt % of m-CNCs in NR.
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- 2015
167. Nanocellulose–Zeolite Composite Films for Odor Elimination
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Farid Akhtar, Farshid Mashayekhy Rad, Amber Mace, Neda Keshavarzi, Farhan Ansari, Lennart Bergström, Ulrika Nilsson, and Lars Berglund
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Volatile Organic Compounds ,Thermogravimetric analysis ,Nanocomposite ,Materials science ,Nanoporous ,Ethanethiol ,Composite number ,Propanethiol ,Solid-phase microextraction ,Nanocomposites ,Nanocellulose ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Odorants ,Zeolites ,Organic chemistry ,General Materials Science ,Colloids ,Sulfhydryl Compounds ,Cellulose - Abstract
Free standing and strong odor-removing composite films of cellulose nanofibrils (CNF) with a high content of nanoporous zeolite adsorbents have been colloidally processed. Thermogravimetric desorption analysis (TGA) and infrared spectroscopy combined with computational simulations showed that commercially available silicalite-1 and ZSM-5 have a high affinity and uptake of volatile odors like ethanethiol and propanethiol, also in the presence of water. The simulations showed that propanethiol has a higher affinity, up to 16%, to the two zeolites compared with ethanethiol. Highly flexible and strong free-standing zeolite-CNF films with an adsorbent loading of 89 w/w% have been produced by Ca-induced gelation and vacuum filtration. The CNF-network controls the strength of the composite films and 100 μm thick zeolite-CNF films with a CNF content of less than 10 vol % displayed a tensile strength approaching 10 MPa. Headspace solid phase microextraction (SPME) coupled to gas chromatography-mass spectroscopy (GC/MS) analysis showed that the CNF-zeolite films can eliminate the volatile thiol-based odors to concentrations below the detection ability of the human olfactory system. Odor removing zeolite-cellulose nanofibril films could enable improved transport and storage of fruits and vegetables rich in odors, for example, onion and the tasty but foul-smelling South-East Asian Durian fruit.
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- 2015
168. Diverging trajectory patterns of systemic versus vascular inflammation over age in healthy Caucasians and African-Americans
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Wei Zhang, Lars Berglund, Kyoungmi Kim, Byambaa Enkhmaa, and Erdembileg Anuurad
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Adult ,Male ,Vasculitis ,Time Factors ,Adolescent ,Composite score ,Inflammation ,Disease ,California ,White People ,Article ,Age Distribution ,Risk Factors ,medicine ,Humans ,Child ,Vascular inflammation ,business.industry ,Age Factors ,Healthy subjects ,Health Status Disparities ,Middle Aged ,Prognosis ,Inflammatory biomarkers ,Healthy Volunteers ,Black or African American ,Cross-Sectional Studies ,Immunology ,Female ,Inflammation Mediators ,medicine.symptom ,Cardiology and Cardiovascular Medicine ,business ,Biomarkers - Abstract
Age and inflammation are risk factors for cardiovascular disease but the impact of inflammation on cardiovascular risk across the lifespan is not understood. We investigated whether an inflammatory burden is modulated by age in healthy subjects.Caucasian and African-American families were recruited from the general population (age range: 6-74 years, n = 267). Systemic inflammation was assessed by C-reactive protein (CRP), serum amyloid A (SAA), fibrinogen, haptoglobin and α-acid glycoprotein, and vascular inflammation was assessed by pentraxin-3 (PTX-3), soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM). To collectively assess systemic or vascular factors across the age spectrum, a composite z-score for each marker category was calculated.There was a contrasting pattern in systemic versus vascular inflammatory burden over age with an increase in systemic but a decrease in vascular markers in both ethnic groups. The results remained unchanged after adjustments for the covariates and covariance. When looking at individual markers to examine which markers are most contributing factors to the composite scores, CRP and SAA were significantly and positively associated with age, while PTX-3 and sVCAM were significantly and negatively associated with age in both ethnic groups.The composite z-score for systemic inflammation increased with age, while the composite z-score for vascular inflammation declined with age, irrespective of ethnicity. The findings illustrate a regulatory relationship between age and inflammation, and suggest that a perceived elevation of vascular markers among the very young may be an indication of physiological changes rather than reflecting a disease process.
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- 2015
169. Influence of processing routes on morphology and low strain stiffness of polymer/nanofibrillated cellulose composites
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Sylvain Galland, Christopher J. G. Plummer, Yves Leterrier, Farhan Ansari, Jan-Anders E. Månson, Pierre-Etienne Bourban, and Lars Berglund
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chemistry.chemical_classification ,Materials science ,Nanocomposite ,Thermoplastic ,Polymers and Plastics ,General Chemical Engineering ,Composite number ,Modulus ,Polymer ,chemistry.chemical_compound ,chemistry ,Materials Chemistry ,Ceramics and Composites ,Extrusion ,Cellulose ,Composite material ,Glass transition - Abstract
The morphology of polymer/nanofibrillated cellulose (NFC) composite sheets produced using different techniques and its influence on low strain stiffness were assessed by optical and transmission electron microscopy. Solvent processing led to relatively homogeneous NFC dispersions and significant reinforcement of the in-plane Young's modulus. The continuous cellular networks obtained by wet comingling of polylactide powder or latex with NFC also provided efficient and essentially scale independent reinforcement, in spite of the extensive agglomeration of the NFC. However, the irreversible nature of these networks is incompatible with low pressure thermoplastic processing routes such as physical foaming, and while they may be broken up by e.g. extrusion, this led to substantial loss in reinforcement, particularly at temperatures above the glass transition temperature of the matrix, consistent with the observation of isolated low aspect ratio NFC aggregates in the extruded specimens.
- Published
- 2015
170. Rhesus monkey (Macaca mulatta) lipoprotein(a) and apolipoprotein(a): high frequency of small size apolipoprotein(a) isoforms
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Adnan Abbuthalha, Wei Zhang, Lars Berglund, Alice F. Tarantal, Erdembileg Anuurad, and Byambaa Enkhmaa
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medicine.medical_specialty ,Apolipoprotein B ,Old World monkey ,Article ,Species Specificity ,Internal medicine ,Genetic variation ,Genotype ,medicine ,Animals ,Humans ,Protein Isoforms ,Genetic variability ,Allele ,Alleles ,Apolipoprotein A-I ,General Veterinary ,biology ,Genetic Variation ,Lipoprotein(a) ,biology.organism_classification ,Macaca mulatta ,Endocrinology ,Immunology ,biology.protein ,lipids (amino acids, peptides, and proteins) ,Animal Science and Zoology ,Lipoprotein - Abstract
Background Levels of lipoprotein(a), Lp(a), a genetically regulated independent cardiovascular risk factor present in humans and Old World monkeys, are impacted by the apolipoprotein(a), apo(a), gene. Allele-specific apo(a) levels, taking both the apo(a) genotypic and phenotypic characteristics into account, are useful markers to determine atherosclerotic cardiovascular risk. Methods We determined (i) the genetic variability of apo(a), (ii) Lp(a) levels, and (iii) allele-specific apo(a) levels in rhesus monkeys (n = 95). Results Lp(a) levels differed substantially between animals (range: 4–247 nmol/l) with a skewed distribution toward lower levels. Lp(a) and allele-specific apo(a) levels were inversely related to the number of apo(a) Kringle 4 (K4) repeats. The median apo(a) size was 23 K4 repeats, and the prevalence of a small size apo(a) (≤22 K4) was 43%. Conclusions Distribution of Lp(a) and allele-specific apo(a) levels in rhesus monkeys reflected the corresponding human patterns, but with a high prevalence of smaller apo(a) sizes.
- Published
- 2015
171. Relation between Cardiovascular Disease Risk Markers and Brain Infarcts Detected by Magnetic Resonance Imaging in an Elderly Population
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Per Venge, Lars Johansson, Lars Berglund, Lars Lind, Håkan Ahlström, Johan Ärnlöv, Ruta Nylander, Bertil Lindahl, Elna-Marie Larsson, Johan Wikström, and Anders Larsson
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Brain Infarction ,Male ,medicine.medical_specialty ,Pathology ,medicine.drug_class ,Population ,Blood Pressure ,Risk Factors ,Internal medicine ,Troponin I ,medicine ,Natriuretic peptide ,Humans ,cardiovascular diseases ,education ,Stroke ,Aged ,education.field_of_study ,medicine.diagnostic_test ,biology ,business.industry ,Rehabilitation ,Brain ,Magnetic resonance imaging ,Odds ratio ,medicine.disease ,Magnetic Resonance Imaging ,Confidence interval ,Cystatin C ,Cardiovascular Diseases ,Cardiology ,biology.protein ,Female ,Surgery ,Neurology (clinical) ,Cardiology and Cardiovascular Medicine ,business ,Biomarkers - Abstract
Background: Established cardiovascular risk markers, such as hypertension, are associated with increased risk of brain infarcts. The newer markers N-terminal pro-brain natriuretic peptide, troponin I, C-reactive protein, and cystatin C may affect the risk of cardiovascular events and potentially, thereby, also stroke. We investigated the association between established and new risk markers for cardiovascular disease and brain infarcts detected by magnetic resonance imaging (MRI) at age 75. Methods: Four hundred six randomly selected subjects from the Prospective Investigation of the Vasculature in Uppsala Seniors study were examined with MRI of the brain at age 75. Blood samples, measurements, and dedicated questionnairesatage70wereusedforanalysisofriskmarkers.Ahistoryofdiseaseshadbeen obtained at age 70 and 75. MRI was evaluated regarding lacunar and cortical infarcts. Univariate associations between outcomes and risk markers were assessed with logistic regression models. Results: One or more infarcts were seen in 23% of the subjects (20% had only lacunar infarcts, 1% had only cortical infarcts, and 2% had both). Hypertension (odds ratio [OR] 2.6, 95% confidence interval [CI] 1.4, 4.7) and obesity (OR 1.3; CI 1.0, 1.8) were significantly associated with increased risk of brain infarction. The newer risk markers were not significantly associated with the brain infarcts. Conclusions: The new markers were not associated with the predominantly lacunar infarcts in our 75-year-old population, why troponin I and NT-proBNP may be associated mainly with cardioembolic infarcts as shown
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- 2015
172. On the use of nanocellulose as reinforcement in polymer matrix composites
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Yvonne Aitomäki, Alexander Bismarck, Kristiina Oksman, Lars Berglund, and Koon-Yang Lee
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chemistry.chemical_classification ,A. Nanocomposites ,Materials science ,A. Polymer–matrix composites (PMCs) ,General Engineering ,Bio based ,Polymer ,C. Modelling ,Nanocellulose ,chemistry ,Ceramics and Composites ,Composite material ,Reinforcement ,A. Short-fibre composites ,Engineering(all) - Abstract
Nanocellulose is often being regarded as the next generation renewable reinforcement for the production of high performance biocomposites. This feature article reviews the various nanocellulose reinforced polymer composites reported in literature and discusses the potential of nanocellulose as reinforcement for the production of renewable high performance polymer nanocomposites. The theoretical and experimentally determined tensile properties of nanocellulose are also reviewed. In addition to this, the reinforcing ability of BC and NFC is juxtaposed. In order to analyse the various cellulose-reinforced polymer nanocomposites reported in literature, Cox–Krenchel and rule-of-mixture models have been used to elucidate the potential of nanocellulose in composite applications. There may be potential for improvement since the tensile modulus and strength of most cellulose nanocomposites reported in literature scale linearly with the tensile modulus and strength of the cellulose nanopaper structures. Better dispersion of individual cellulose nanofibres in the polymer matrix may improve composite properties.
- Published
- 2014
173. Omentectomy in addition to gastric bypass surgery and influence on insulin sensitivity: A randomized double blind controlled trial
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Anders Thorell, Anders Thörne, Peter Arner, P. Löfgren, Veronica Qvisth, Lars Berglund, Erik Näslund, Johan Hoffstedt, Sven Bringman, Eva Toft, Ulf Risérus, Mikael Wirén, and Daniel P. Andersson
- Subjects
Adult ,Blood Glucose ,medicine.medical_specialty ,Gastric Bypass ,Adipose tissue ,Intra-Abdominal Fat ,Critical Care and Intensive Care Medicine ,medicine.disease_cause ,Gastroenterology ,Body Mass Index ,law.invention ,Young Adult ,Insulin resistance ,Double-Blind Method ,Randomized controlled trial ,Risk Factors ,law ,Weight loss ,Internal medicine ,Weight Loss ,medicine ,Humans ,Obesity ,Dual-energy X-ray absorptiometry ,Nutrition and Dietetics ,medicine.diagnostic_test ,Gastric bypass surgery ,business.industry ,Middle Aged ,medicine.disease ,Surgery ,Clinical trial ,Omentectomy ,Treatment Outcome ,Glucose Clamp Technique ,Female ,Insulin Resistance ,medicine.symptom ,business ,Omentum - Abstract
Summary Background & aims Accumulation of visceral adipose tissue is associated with insulin resistance and cardio-vascular disease. The aim of this study was to elucidate whether removal of a large amount of visceral fat by omentectomy in conjunction with Roux en-Y gastric bypass operation (RYGB) results in enhanced improvement of insulin sensitivity compared to gastric bypass surgery alone. Methods Eighty-one obese women scheduled for RYGB were included in the study. They were randomized to RYGB or RYGB in conjunction with omentectomy. Insulin sensitivity was measured by hyperinsulinemic euglycemic clamp before operation and sixty-two women were also reexamined 2 years post-operatively. The primary outcome measure was insulin sensitivity and secondary outcome measures included cardio-metabolic risk factors. Results Two-year weight loss was profound but unaffected by omentectomy. Before intervention, there were no clinical or metabolic differences between the two groups. The difference in primary outcome measure, insulin sensitivity, was not significant between the non-omentectomy (6.7 ± 1.6 mg/kg body weight/minute) and omentectomy groups (6.6 ± 1.5 mg/kg body weight/minute) after 2 years. Nor did any of the cardio-metabolic risk factors that were secondary outcome measures differ significantly. Conclusion Addition of omentectomy to gastric bypass operation does not give an incremental effect on long term insulin sensitivity or cardio-metabolic risk factors. The clinical usefulness of omentectomy in addition to gastric bypass operation is highly questionable. Clinical Trial Registration number: NCT01785134 .
- Published
- 2014
174. Transparent Wood Smart Windows: Polymer Electrochromic Devices Based on Poly(3,4-Ethylenedioxythiophene):Poly(Styrene Sulfonate) Electrodes
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Augustus W, Lang, Yuanyuan, Li, Michel, De Keersmaecker, D Eric, Shen, Anna M, Österholm, Lars, Berglund, and John R, Reynolds
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electrochemistry ,thin films ,Full Paper ,Construction Materials ,Polymers ,electrochromism ,Polystyrenes ,Color ,Full Papers ,Bridged Bicyclo Compounds, Heterocyclic ,Electrodes ,Wood - Abstract
Transparent wood composites, with their high strength and toughness, thermal insulation, and excellent transmissivity, offer a route to replace glass for diffusely transmitting windows. Here, conjugated‐polymer‐based electrochromic devices (ECDs) that switch on‐demand are demonstrated using transparent wood coated with poly(3,4‐ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) as a transparent conducting electrode. These ECDs exhibit a vibrant magenta‐to‐clear color change that results from a remarkably colorless bleached state. Furthermore, they require low energy and power inputs of 3 mWh m−2 at 2 W m−2 to switch due to a high coloration efficiency (590 cm2 C−1) and low driving voltage (0.8 V). Each device component is processed with high‐throughput methods, which highlights the opportunity to apply this approach to fabricate mechanically robust, energy‐efficient smart windows on a large scale.
- Published
- 2017
175. Transparent wood for functional and structural applications
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Xuan Yang, Lars Berglund, Yuanyuan Li, and Qiliang Fu
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Engineering ,Other Engineering and Technologies ,New horizons ,General Mathematics ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,General Physics and Astronomy ,Physics::Optics ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,7. Clean energy ,01 natural sciences ,Preparation method ,transparent wood ,Annan teknik ,optical performance ,Building automation ,business.industry ,General Engineering ,functionalization and application ,Articles ,021001 nanoscience & nanotechnology ,mechanical performance ,0104 chemical sciences ,Improved performance ,13. Climate action ,Photonics ,0210 nano-technology ,business ,Realization (systems) - Abstract
Optically transparent wood combines mechanical performance with optical functionalities is an emerging candidate for applications in smart buildings and structural optics and photonics. The present review summarizes transparent wood preparation methods, optical and mechanical performance, and functionalization routes, and discusses potential applications. The various challenges are discussed for the purpose of improved performance, scaled-up production and realization of advanced applications. This article is part of a discussion meeting issue ‘New horizons for cellulose nanotechnology’.
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- 2017
176. The roles of apo(a) size, phenotype, and dominance pattern in PCSK9-inhibition-induced reduction in Lp(a) with alirocumab[S]
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Lars Berglund, Wei Zhang, Erdembileg Anuurad, Byambaa Enkhmaa, Ching-Shang Li, and Kun Yue
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medicine.medical_specialty ,Familial hypercholesterolemia ,QD415-436 ,030204 cardiovascular system & hematology ,Antibodies, Monoclonal, Humanized ,Apoprotein(a) ,Biochemistry ,03 medical and health sciences ,0302 clinical medicine ,Endocrinology ,Internal medicine ,medicine ,Humans ,Protein Isoforms ,Protease Inhibitors ,030212 general & internal medicine ,clinical studies ,Research Articles ,Dominance (genetics) ,Alirocumab ,biology ,PCSK9 ,lipoprotein (a) ,PCSK9 Inhibitors ,Antibodies, Monoclonal ,drug therapy/hypolipidemic drugs ,Cell Biology ,Lipoprotein(a) ,apolipoprotein (a) ,medicine.disease ,Proprotein convertase ,lipoproteins ,Phenotype ,Gene Expression Regulation ,biology.protein ,Kexin ,lipids (amino acids, peptides, and proteins) ,apolipoproteins ,Lipoprotein - Abstract
An elevated level of lipoprotein (a) [Lp(a)] is a risk factor for CVD. Alirocumab, a monoclonal antibody to proprotein convertase subtilisin/kexin type 9, is reported to reduce Lp(a) levels. The relationship of Lp(a) reduction with apo(a) size polymorphism, phenotype, and dominance pattern and LDL cholesterol (LDL-C) reduction was evaluated in a pooled analysis of 155 hypercholesterolemic patients (75 with heterozygous familial hypercholesterolemia) from two clinical trials. Alirocumab significantly reduced total Lp(a) (pooled median: −21%, P = 0.0001) and allele-specific apo(a), an Lp(a) level carried by the smaller (median: −18%, P = 0.002) or the larger (median: −37%, P = 0.0005) apo(a) isoform, at week 8 versus baseline. The percent reduction in Lp(a) level with alirocumab was similar across apo(a) phenotypes (single vs. double bands) and carriers and noncarriers of a small size apo(a) (≤22 kringles). The percent reduction in LDL-C correlated significantly with the percent reduction in Lp(a) level (r = 0.407, P < 0.0001) and allele-specific apo(a) level associated with the smaller (r = 0.390, P < 0.0001) or larger (r = 0.270, P = 0.0183) apo(a) sizes. In conclusion, alirocumab-induced Lp(a) reduction was independent of apo(a) phenotypes and the presence or absence of a small size apo(a).
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- 2017
177. Bioinspired Wood Nanotechnology for Functional Materials
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Lars Berglund and Ingo Burgert
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Materials science ,Mechanics of Materials ,Mechanical Engineering ,General Materials Science ,Nanotechnology ,02 engineering and technology ,Bioinspiration ,010402 general chemistry ,021001 nanoscience & nanotechnology ,0210 nano-technology ,01 natural sciences ,7. Clean energy ,0104 chemical sciences - Abstract
It is a challenging task to realize the vision of hierarchically structured nanomaterials for large-scale applications. Herein, the biomaterial wood as a large-scale biotemplate for functionalization at multiple scales is discussed, to provide an increased property range to this renewable and CO2 -storing bioresource, which is available at low cost and in large quantities. The Progress Report reviews the emerging field of functional wood materials in view of the specific features of the structural template and novel nanotechnological approaches for the development of wood-polymer composites and wood-mineral hybrids for advanced property profiles and new functions.
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- 2017
178. Angels or Sirens? Questions of Performance and Reception in Roman Church Music around 1650
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Lars Berglund
- Published
- 2017
179. Reduced live-birth rates after IVF/ICSI in women with previous unilateral oophorectomy: results of a multicentre cohort study
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Elizabeth Nedstrand, Kenny A. Rodriguez-Wallberg, Jan I. Olofsson, Johannes Gudmundsson, Tekla Lind, Lars Berglund, Jan Holte, Mikael Lood, and Nermin Hadziosmanovic
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0301 basic medicine ,Infertility ,Adult ,medicine.medical_specialty ,Ovarian surgery ,Ovariectomy ,Ovary ,Fertilization in Vitro ,Cohort Studies ,03 medical and health sciences ,0302 clinical medicine ,Ovulation Induction ,Pregnancy ,medicine ,Humans ,Sperm Injections, Intracytoplasmic ,reproductive and urinary physiology ,Retrospective Studies ,Sweden ,030219 obstetrics & reproductive medicine ,urogenital system ,Obstetrics ,business.industry ,Rehabilitation ,Pregnancy Outcome ,Obstetrics and Gynecology ,Unilateral Oophorectomy ,Ivf icsi ,medicine.disease ,female genital diseases and pregnancy complications ,030104 developmental biology ,medicine.anatomical_structure ,Reproductive Medicine ,embryonic structures ,Female ,business ,Live birth ,therapeutics ,Cohort study - Abstract
Is there a reduced live-birth rate (LBR) after IVF/ICSI treatment in women with a previous unilateral oophorectomy (UO)?A significantly reduced LBR after IVF/ICSI was found in women with previous UO when compared with women with intact ovaries in this large multicentre cohort, both crudely and after adjustment for age, BMI, fertility centre and calendar period and regardless of whether the analysis was based on transfer of embryos in the fresh cycle only or on cumulative results including transfers using frozen-thawed embryos.Similar pregnancy rates after IVF/ICSI have been previously reported in case-control studies and small cohort studies of women with previous UO versus women without ovarian surgery. In all previous studies multiple embryos were transferred. No study has previously evaluated LBR in a large cohort of women with a history of UO.This research was a multicentre cohort study, including five reproductive medicine centres in Sweden: Carl von Linné Clinic (A), Karolinska University Hospital (B), Uppsala University Hospital (C), Linköping University Hospital (D) and Örebro University Hospital (E). The women underwent IVF/ICSI between January 1999 and November 2015. Single embryo transfer (SET) was performed in approximately 70% of all treatments, without any significant difference between UO exposed women versus controls (68% versus 71%), respectively (P = 0.32), and a maximum of two embryos were transferred in the remaining cases. The dataset included all consecutive treatments and fresh and frozen-thawed cycles.The exposed cohort included 154 women with UO who underwent 301 IVF/ICSI cycles and the unexposed control cohort consisted of 22 693 women who underwent 41 545 IVF/ICSI cycles. Overall, at the five centres (A-E), the exposed cohort underwent 151, 34, 35, 41 and 40 treatments, respectively, and they were compared with controls of the same centre (18 484, 8371, 5575, 4670 and 4445, respectively). The primary outcome was LBR, which was analysed per started cycle, per ovum pick-up (OPU) and per embryo transfer (ET). Secondary outcomes included the numbers of oocytes retrieved and supernumerary embryos obtained, the Ovarian Sensitivity Index (OSI), embryo quality scores and cumulative pregnancy rates. We used a Generalized Estimating Equation (GEE) model for statistical analysis in order to account for repeated treatments.The exposed (UO) and control women's groups were comparable with regard to age and performance of IVF or ICSI. Significant differences in LBR, both crude and age-adjusted, were observed between the UO and control groups: LBR per started cycle (18.6% versus 25.4%, P = 0.007 and P = 0.014, respectively), LBR/OPU (20.3% versus 27.1%, P = 0.012 and P = 0.015, respectively) and LBR/ET (23.0% versus 29.7%, P = 0.022 and P = 0.025, respectively). The differences in LBR remained significant after inclusion of both fresh and frozen-thawed transfers (both crude and age-adjusted data): LBR/OPU (26.1% versus 34.4%, P = 0.005 and P = 0.006, respectively) and LBR/ET (28.3% versus 37.1%, P = 0.006 and P = 0.006, respectively). The crude cancellation rate was significantly higher among women with a history of UO than in controls (18.9% versus 14.5%, P = 0.034 and age-adjusted, P = 0.178). In a multivariate GEE model, the cumulative odds ratios for LBR (fresh and frozen-thawed)/OPU (OR 0.70, 95% CI 0.52-0.94, P = 0.016) and LBR (fresh and frozen-thawed)/ET (OR 0.68, 95% CI 0.51-0.92, P = 0.012) were approximately 30% lower in the group of women with UO when adjusted for age, BMI, reproductive centre, calendar period and number of embryos transferred when appropriate. The OSI was significantly lower in women with a history of UO than in controls (3.6 versus 6.0) and the difference was significant for both crude and age-adjusted data (P =0.001 for both). Significantly fewer oocytes were retrieved in treatments of women with UO than in controls (7.2 versus 9.9, P =0.001, respectively).Due to the nature of the topic, this is a retrospective analysis, with all its inherent limitations. Furthermore, the cause for UO was not possible to obtain in all cases. A diagnosis of endometriosis was also more common in the UO group, i.e. a selection bias in terms of poorer patient characteristics in the UO group cannot be completely ruled out. However, adjustment for all known confounders did not affect the general results.To date, this is the largest cohort investigated and the first study indicating an association of achieving reduced live birth after IVF/ICSI in women with previous UO. These findings are novel and contradict the earlier notion that IVF/ICSI treatment is not affected, or is only marginally affected by previous UO.None.Not applicable.
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- 2017
180. Lignin-Retaining Transparent Wood
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Yuanyuan Li, Qiliang Fu, Ramiro Rojas, Min Yan, Martin Lawoko, and Lars Berglund
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delignification ,building materials ,Optical Phenomena ,Full Paper ,energy saving ,lignin ,Green Chemistry Technology ,Kompositmaterial och -teknik ,Full Papers ,Wood ,Composite Science and Engineering ,Lignans ,wood - Abstract
Optically transparent wood, combining optical and mechanical performance, is an emerging new material for light-transmitting structures in buildings with the aim of reducing energy consumption. One of the main obstacles for transparent wood fabrication is delignification, where around 30wt% of wood tissue is removed to reduce light absorption and refractive index mismatch. This step is time consuming and not environmentally benign. Moreover, lignin removal weakens the wood structure, limiting the fabrication of large structures. A green and industrially feasible method has now been developed to prepare transparent wood. Up to 80wt% of lignin is preserved, leading to a stronger wood template compared to the delignified alternative. After polymer infiltration, a high-lignin-content transparent wood with transmittance of 83%, haze of 75%, thermal conductivity of 0.23WmK(-1), and work-tofracture of 1.2MJm(-3) (a magnitude higher than glass) was obtained. This transparent wood preparation method is efficient and applicable to various wood species. The transparent wood obtained shows potential for application in energy-saving buildings. QC 20171024
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- 2017
181. Enhancing strength and toughness of cellulose nanofibril network structures with an adhesive peptide
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Hu Tang, Eliane Trovatti, Qijun Meng, Lars Berglund, Alessandro Gandini, Qi Zhou, and Alireza Hajian
- Subjects
Toughness ,Materials science ,Polymers and Plastics ,Nanofibers ,Network structure ,Peptide ,02 engineering and technology ,010402 general chemistry ,Microscopy, Atomic Force ,01 natural sciences ,Cyclic N-Oxides ,chemistry.chemical_compound ,X-Ray Diffraction ,Adhesives ,Tensile Strength ,Materials Testing ,Spectroscopy, Fourier Transform Infrared ,Materials Chemistry ,Amino Acid Sequence ,Cellulose ,Composite material ,chemistry.chemical_classification ,Nanocomposite ,Organic Chemistry ,Temperature ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Amino acid ,chemistry ,Adhesive ,Adsorption ,0210 nano-technology ,Peptides ,Oxidation-Reduction - Abstract
The mechanical properties of cellulose nanofibrils network structure are essential for their applications in functional materials. In this work, an adhesive peptide consisting of just 11 amino acid residues with a hydrophobic core sequence of FLIVI (F - phenylalanine, L - leucine, I - isoleucine, V - valine) flanked by three lysine (K) residues was adsorbed to 2,2,6,6-Tetramethyl-1-piperidinyloxy radical (TEMPO) oxidized cellulose nanofibrils (TO-CNF). Composite films were prepared by solution casting from water suspensions of TO-CNF adsorbed with the adhesive peptide. The nanofibrils network structure of the composite was characterized by atomic force microscopy (AFM). The structure of the peptide in the composites and the interactions between TO-CNF and the peptide were studied by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The mechanical properties of the composites were characterized by tensile tests and dynamic mechanical analysis (DMA). With 6.3wt.% adhesive peptide adsorbed onto TO-CNF, the composite showed a modulus of 12.5±1.4GPa, a tensile strength of 344.5±(15.3)MPa, and a strain to failure of 7.8±0.4%, which are 34.4%, 48.8%, and 23.8% higher than those for neat TO-CNF, respectively. This resulted in significantly improved toughness (work to fracture) for the composite, 77% higher than that for the neat TO-CNF.
- Published
- 2017
182. High-Strength Nanocomposite Aerogels of Ternary Composition: Poly(vinyl alcohol), Clay, and Cellulose Nanofibrils
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Lilian Medina, Lars Berglund, and Andong Liu
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Vinyl alcohol ,Nanocomposite ,Materials science ,Aerogel ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,Montmorillonite ,Compressive strength ,chemistry ,General Materials Science ,Fourier transform infrared spectroscopy ,Composite material ,0210 nano-technology ,Ternary operation ,Porosity - Abstract
Clay aerogels are foam-like materials with potential to combine high mechanical performance with fire retardancy. However, the compression strength of these aerogels is much lower than theoretically predicted values. High-strength aerogels with more than 95% porosity were prepared from a ternary material system based on poly(vinyl alcohol), montmorillonite clay platelets, and cellulose nanofibrils. A hydrocolloidal suspension of the three components was subjected to freeze-drying so that a low-density aerogel foam was formed. Cell structure was studied by field-emission scanning electron microscopy. Interactions at the molecular scale were observed by X-ray diffraction and Fourier transform infrared spectroscopy. Cross-linking was carried out using glutaraldehyde or borax, and moisture stability was investigated. These biobased ternary aerogels showed compression strength much better than that of previously studied materials and also showed strength higher than that of high-performance sandwich foam cores such as cross-linked polyvinyl chloride foams.
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- 2017
183. Lasing from Organic Dye Molecules Embedded in Transparent Wood
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Elena Vasileva, Yuanyuan Li, Ilya Sychugov, Mounir Mensi, Lars Berglund, Sergei Popov
- Published
- 2017
- Full Text
- View/download PDF
184. Transparent Wood: Luminescent Transparent Wood (Advanced Optical Materials 1/2017)
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Jan Linnros, Jonathan G. C. Veinot, Lars Berglund, Shun Yu, Ilya Sychugov, and Yuanyuan Li
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Materials science ,Quantum dot ,business.industry ,Optical materials ,Optoelectronics ,Luminescence ,business ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials - Published
- 2017
185. Luminescent Transparent Wood
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Yuanyuan Li, Shun Yu, Jonathan G. C. Veinot, Jan Linnros, Lars Berglund, Ilya Sychugov
- Published
- 2017
- Full Text
- View/download PDF
186. Impact of Nationwide Antibiotic Administrative Programmes on Antibiotic Usage and Antibacterial Resistance for Clinical Isolates Over a Two-year Period in 14 Chinese and 5 Swedish Tertiary Hospitals
- Author
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Lars Berglund, Yonghong Xiao, Qing Yan, Hua Yu, Staffan Sylvan, XiaoqiangYang, and Yong Yu
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Antibiotic resistance ,Antibacterial resistance ,Resistance pattern ,medicine.drug_class ,business.industry ,Environmental health ,Antibiotics ,Nosocomial pathogens ,medicine ,Medical prescription ,Antibiotic use ,business - Abstract
The aims of this 2-year multicentre study are to systematically evaluate and establish a reference baseline for the resistance of clinically relevant bacterial isolates in 14 tertiary hospitals in China and 5 Swedish hospitals and to characterise the current use of antibiotics in these hospitals. We also aimed to assess the impact of national antibiotic administrative policies on antibiotic use and resistance patterns of the leading nosocomial pathogens in the hospitals. The present study was done at a time when Chinese health authorities launched a campaign to discourage over prescription of antibiotics. At present, it seems their efforts are having a meaningful impact. Following the implementation of the intensive control programme in Chinese tertiary hospitals, we found that the consumption levels of parenteral antimicrobials were reduced and accompanied by a significant increase in susceptibility patterns of both Gram-positive and Gram-negative bacteria, including ESBL-producing organisms. During the 2-year study period, no significant change in the level of resistance to commonly used antibiotic groups could be noted in the clinical isolates from the five Swedish tertiary hospitals.
- Published
- 2017
187. Sustained Effects of a Nurse Coaching Intervention via Telehealth to Improve Health Behavior Change in Diabetes
- Author
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Lars Berglund, Heather M. Young, Deborah Ward, Yajarayma J. Tang-Feldman, Sheridan Miyamoto, and Madan Dharmar
- Subjects
Rural Population ,Male ,Health Behavior ,Motivational interviewing ,Rural Health ,Telehealth ,Coaching ,telenursing ,7.1 Individual care needs ,Health Information Management ,Surveys and Questionnaires ,Medicine ,Original Research ,diabetes ,Behavior change ,General Medicine ,Middle Aged ,Self Efficacy ,Telemedicine ,Patient Satisfaction ,technology ,Public Health and Health Services ,Female ,Adult ,medicine.medical_specialty ,telehealth ,education ,Biomedical Engineering ,Health Informatics ,Motivational Interviewing ,behavioral health ,Patient satisfaction ,Library and Information Studies ,Nursing ,Clinical Research ,Behavioral and Social Science ,Diabetes Mellitus ,Humans ,Metabolic and endocrine ,Aged ,Nutrition ,Self-efficacy ,business.industry ,Prevention ,Good Health and Well Being ,Telenursing ,Physical therapy ,Management of diseases and conditions ,Nurse-Patient Relations ,business ,Mind and Body ,Medical Informatics - Abstract
Background: Diabetes educators and self-management programs are scarce in rural communities, where diabetes is the third highest-ranking health concern. The goal of this study was to evaluate the benefits of nurse telehealth coaching for persons with diabetes living in rural communities through a person-centered approach using motivational interviewing (MI) techniques. Materials and Methods: A randomized experimental study design was used to assign participants to receive either nurse telehealth coaching for five sessions (intervention group) or usual care (control group). Outcomes were measured in both groups using the Diabetes Empowerment Scale (DES), SF-12, and satisfaction surveys. Mean scores for each outcome were compared at baseline and at the 9-month follow-up for both groups using a Student's t test. We also evaluated the change from baseline by estimating the difference in differences (pre- and postintervention) using regression methods. Results: Among the 101 participants included in the analysis, 51 received nurse telehealth coaching, and 50 received usual care. We found significantly higher self-efficacy scores in the intervention group compared with the control group based on the DES at 9 months (4.03 versus 3.64, respectively; p
- Published
- 2014
188. Superior mechanical performance of highly porous, anisotropic nanocellulose–montmorillonite aerogels prepared by freeze casting
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Ulrike G. K. Wegst, Andong Liu, Lars Berglund, and Amalie E. Donius
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Toughness ,Hot Temperature ,Materials science ,Isotropy ,Composite number ,Nanofibers ,Biomedical Engineering ,Modulus ,Aerogel ,Nanocellulose ,Biomaterials ,chemistry.chemical_compound ,Compressive strength ,Montmorillonite ,chemistry ,Mechanics of Materials ,Freezing ,Bentonite ,Anisotropy ,Nanotechnology ,Composite material ,Cellulose ,Gels ,Porosity ,Mechanical Phenomena - Abstract
Directionally solidified nanofibrillated cellulose (NFC)–sodium-montmorillonite (MMT) composite aerogels with a honeycomb-like pore structure were compared with non-directionally frozen aerogels with equiaxed pore structure and identical composition and found to have superior functionalities. To explore structure-property correlations, three different aerogel compositions of 3 wt% MMT, and 0.4 wt%, 0.8 wt%, and 1.2 wt% NFC, respectively, were tested. Young׳s modulus, compressive strength and toughness were found to increase with increasing NFC content for both architectures. The modulus increased from 25.8 kPa to 386 kPa for the isotropic and from 2.13 MPa to 3.86 MPa for the anisotropic aerogels, the compressive yield strength increased from 3.3 kPa to 18.0 kPa for the isotropic and from 32.3 kPa to 52.5 kPa for the anisotropic aerogels, and the toughness increased from 6.3 kJ/m3 to 24.1 kJ/m3 for the isotropic and from 22.9 kJ/m3 to 46.2 kJ/m3 for the anisotropic aerogels. The great range of properties, which can be achieved through compositional as well as architectural variations, makes these aerogels highly attractive for a large range of applications, for which either a specific composition, or a particular pore morphology, or both are required. Finally, because NFC is flammable, gasification experiments were performed, which revealed that the inclusion of MMT increased the heat endurance and shape retention functions of the aerogels dramatically up to 800 °C while the mechanical properties were retained up to 300 °C.
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- 2014
189. Cellulose nanofiber network for moisture stable, strong and ductile biocomposites and increased epoxy curing rate
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Mats Johansson, Farhan Ansari, Chris Plummer, Lars Berglund, and Sylvain Galland
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B. Cure behavior ,B. Interface ,Materials science ,Nanocomposite ,Cure behavior ,Moisture ,Epoxy ,Interface ,chemistry.chemical_compound ,Nano-structures ,chemistry ,Mechanics of Materials ,A. Nano-structures ,Nanofiber ,visual_art ,Acetone ,visual_art.visual_art_medium ,Ceramics and Composites ,Composite material ,Cellulose ,Porosity ,Curing (chemistry) ,Nanocellulose biocomposite - Abstract
Nanocomposites with high volume fractions (15-50 vol%) of nanofibrillated cellulose (NFC) were prepared by impregnation of a wet porous NFC network with acetone/epoxy/amine solution. Infrared spectroscopy studies revealed a significant increase in curing rate of epoxy (EP) in the presence of NFC. The NFC provided extremely efficient reinforcement (at 15 vol%: 3-fold increase in stiffness and strength to 5.9 GPa and 109 MPa, respectively), and ductility was preserved. Besides, the glass transition temperature increased with increasing NFC content (from 68 degrees C in neat epoxy to 86 degrees C in 50 vol% composite). Most interestingly, the moisture sorption values were low and even comparable to neat epoxy for the 15 vol% NFC/EP. This material did not change mechanical properties at increased relative humidity (90% RH). Thus, NFC/EP provides a unique combination of high strength, modulus, ductility, and moisture stability for a cellulose-based biocomposite. Effects from nanostructural and interfacial tailoring are discussed. (C) 2014 The Authors. Published by Elsevier Ltd.
- Published
- 2014
- Full Text
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190. Preparation of Double Pickering Emulsions Stabilized by Chemically Tailored Nanocelluloses
- Author
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Isabelle Capron, Bernard Cathala, Jean-Bruno Mougel, Ana G. Cunha, Lars Berglund, Unité de recherche sur les Biopolymères, Interactions Assemblages (BIA), Institut National de la Recherche Agronomique (INRA), and Royal Institute of Technology in Stockholm (KTH)
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Nanostructure ,Materials science ,Surface Properties ,Nanoparticle ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Nanocellulose ,chemistry.chemical_compound ,Electrochemistry ,General Materials Science ,Particle Size ,Cellulose ,Spectroscopy ,[CHIM.ORGA]Chemical Sciences/Organic chemistry ,Chemical modification ,Surfaces and Interfaces ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Pickering emulsion ,Nanostructures ,0104 chemical sciences ,chemistry ,Nanofiber ,Emulsions ,Particle size ,0210 nano-technology - Abstract
International audience; Nanocelluloses are bio-based nanoparticles of interest as stabilizers for oil-in-water (o/w) Pickering emulsions. In this work, the surface chemistry of nanocelluloses of different length, nanofibrillated cellulose (NFC, long) and cellulose nanocrystals (CNC, short), was successfully tailored by chemical modification with lauroyl chloride (C12). The resulting nanofibers were less hydrophilic than the original and able to stabilize water-in-oil (w/o) emulsions. The combination of the two types of nanocelluloses (C12-modified and native) led to new surfactant-free oil-in-water-in-oil (o/w/o) double emulsions stabilized by nanocellulose at both interfaces. Characterization was performed with respect to droplet size distribution, droplet stability over time, and stability after centrifugation. Nanocellulose-based Pickering emulsions can be designed with a substantial degree of control, as demonstrated by the stability of the chemically tailored NFC double emulsions. Furthermore, it was demonstrated that increased nanofiber length leads to increased stability.
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- 2014
191. Nanofibrillated cellulose reinforced acetylated arabinoxylan films
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Farhan Ansari, Agnes Stépán, Lars Berglund, and Paul Gatenholm
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Nanocomposite ,Materials science ,Scanning electron microscope ,Composite number ,General Engineering ,Plasticizer ,chemistry.chemical_compound ,chemistry ,Ultimate tensile strength ,Arabinoxylan ,Ceramics and Composites ,Hemicellulose ,Cellulose ,Composite material - Abstract
In this study, acetylated rye arabinoxylan (AcAX) films were reinforced with nanofibrillated cellulose from spruce (NFC) ranging from I to 10 wt% of the total composition. Free-standing composite films were casted without the use of any plasticizers. The homogeneous dispersion of NFC in the films was confirmed with scanning electron microscopy. The ultimate strength and the Young's modulus determined by tensile tests increased from 65 MPa and 2190 MPa for neat AcAX films to 93 MPa and 3360 MPa for the 10% composite films, respectively. The elongation to break of the 10% NFC composite film was a remarkable 10.5%. The moisture absorbed was still less than 8 wt% for the films with 10% NFC content at 97% relative humidity at room temperature, which is low for hemicellulose-based films. The addition of NFC decreased the water permeability of the films at low NFC contents, which was studied in diffusion cells using radioactive labeled water. Thus NFC can be used in an unmodified form as reinforcement in AcAX films to prepare films or coatings that are more water and humidity resistant than neat hemicellulose-based films. (C) 2014 Elsevier Ltd. All rights reserved.
- Published
- 2014
192. Cellulose Nanofiber/Nanocrystal Reinforced Capsules: A Fast and Facile Approach Toward Assembly of Liquid-Core Capsules with High Mechanical Stability
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Jens Risbo, Christian Wohnhaas, Max Bernhardt, Gunnar Glasser, Anna Musyanovych, Michael Kappl, Katharina Landfester, Lars Berglund, and Anna J. Svagan
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Materials science ,Molecular Structure ,Polymers and Plastics ,Surface Properties ,Nanofibers ,Capsule ,Capsules ,Bioengineering ,Nanotechnology ,Biomaterials ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Nanocrystal ,Nanofiber ,Materials Chemistry ,Nanoparticles ,Particle size ,Particle Size ,Cellulose ,Layer (electronics) ,Elastic modulus ,Polyurea - Abstract
Liquid-core capsules of high mechanical stability open up for many solid state-like applications where functionality depending on liquid mobility is vital. Herein, a novel concept for fast and facile improvement of the mechanical properties of walls of liquid-core capsules is reported. By imitating nature's own way of enhancing the mechanical properties in liquid-core capsules, the parenchyma plant cells found in fruits and vegetables, a blend of short cellulose nanofibers (1 μm, NFC) and nanocrystals (CNC) was exploited in the creation of the capsule walls. The NFC/CNC blend was prepared from a new version of the classical wood pulp hydrolysis. The capsule shell consisted of a covalently (by aromatic diisocyanate) cross-linked NFC/CNC structure at the outer capsule wall and an inner layer dominated by aromatic polyurea. The mechanical properties revealed an effective capsule elastic modulus of 4.8 GPa at 17 wt % NFC/CNC loading, about six times higher compared to a neat aromatic polyurea capsule (0.79 GPa) and 3 orders of magnitude higher than previously reported capsules from regenerated cellulose (0.0074 GPa). The outstanding mechanical properties are ascribed to the dense nanofiber structure, present in the outer part of the capsule wall, that is formed by oriented NFC/CNC of high average aspect ratio (L/d ∼ 70) and held together by both covalent (urethane bonds) and physical bonds (hydrogen bonds).
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- 2014
193. Wood cell wall mimicking for composite films of spruce nanofibrillated cellulose with spruce galactoglucomannan and arabinoglucuronoxylan
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Kirsi S. Mikkonen, Maija Tenkanen, Lars Berglund, Chunlin Xu, Jasna S. Stevanic, and Lennart Salmén
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Vinyl alcohol ,Materials science ,Moisture ,Mechanical Engineering ,Composite number ,Mixing (process engineering) ,Sorption ,Cell wall ,chemistry.chemical_compound ,chemistry ,Mechanics of Materials ,General Materials Science ,Composite material ,Cellulose ,Galactoglucomannan - Abstract
Two hemicelluloses (HCs), galactoglucomannan (GGM) and arabinoglucuronoxylan (AGX), and nanofibrillated cellulose (NFC) were isolated from spruce wood and used for the preparation of composite films containing high amounts of cellulose, i.e. 85 and 80 wt% of NFC, respectively. The films were prepared in two ways: (i) by the pre-sorption of HCs on NFC and (ii) by the mixing of components in the usual way. Pre-sorption was applied in an attempt to mimic the carbohydrate biosynthesis pattern during wood cell wall development, where HCs were deposited on the cellulose fibrils prior to lignification taking place. It was assumed that pre-sorption would result in a better film-forming as well as stronger and denser composite films. The mechanical, thermal, structural, moisture sorption and oxygen barrier characteristics of such composite films were tested in order to examine whether the performance of composite films prepared by pre-sorption was better, when compared to the performance of composite films prepared by mixing. The performance of composite films was also tested with respect to the HCs used. All the films showed quite similar barrier and mechanical properties. In general, stiff, strong and quite ductile films were produced. The moisture sorption of the films was comparably low. The oxygen barrier properties of the films were in the range of commercially used poly ethylene vinyl alcohol films. However, the pre-sorption procedure for the preparation of composite films resulted in no additional improvement in the performance of the films compared to the corresponding composite films that had been prepared using the mixing process. Almost certainly, the applied mixing process led to an optimal mixing of components for the film performance achieved. The GGM contributed to a somewhat better film performance than the AGX did. Indications were observed for stronger interactions between the GGM and NFC than that for the AGX and NFC.
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- 2014
194. Cellulose Nanocomposites by Melt Compounding of TEMPO-Treated Wood Fibers in Thermoplastic Starch Matrix
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Lars Berglund, Aline Cobut, and Houssine Sehaqui
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chemistry.chemical_classification ,Environmental Engineering ,Thermoplastic ,Materials science ,Nanocomposite ,Starch ,Extrusion ,Pulp (paper) ,lcsh:Biotechnology ,Bioengineering ,Mechanical properties ,engineering.material ,Nanocomposites ,chemistry.chemical_compound ,chemistry ,Compounding ,Amylopectin ,lcsh:TP248.13-248.65 ,engineering ,Cellulose nanofibrils ,Cellulose ,Composite material ,Waste Management and Disposal ,Thermoplastic starch - Abstract
To facilitate melt compounding of cellulose nanofibrils (CNF) based composites, wood pulp fibers were subjected to a chemical treatment whereby the fibers were oxidized using 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO). This treatment introduced negatively charged carboxylate groups to the fibers. TEMPO-treated fibers (TempoF) were added to a mixture of amylopectin starch, glycerol, and water. Granules were prepared from this mixture and processed into CNF composites by extrusion. TempoF were easier to process into composites as compared with non-treated pulp fibers (PF). SEM revealed partial disintegration of TempoF during melt processing. Consequently, TempoF gave composites with much better mechanical properties than those of conventional composites prepared from pulp fibers and TPS. Particularly, at 20 wt% TempoF content in the composite, the modulus and strength were much improved. Such a continuous melt processing route, as an alternative to laboratory solvent casting techniques, may promote large-scale production of CNF-based composites as an environmentally friendly alternative to synthetic plastics/composites.
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- 2014
195. Analysis of intraosseous samples in endotoxemic shock - an experimental study in the anaesthetised pig
- Author
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Lars Berglund, Miklos Lipcsey, Anders Larsson, Gunnar Strandberg, and Mats Eriksson
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medicine.medical_specialty ,Anesthesiology and Pain Medicine ,business.industry ,Shock (circulatory) ,Emergency medicine ,medicine ,General Medicine ,medicine.symptom ,Intensive care medicine ,business ,Emergency situations ,Blood sampling - Abstract
BackgroundIntraosseous (IO) access is used in emergency situations to allow rapid initiation of treatment. IO access is also sometimes used for blood sampling, although data on accuracy of such sam ...
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- 2014
196. Highly Conducting, Strong Nanocomposites Based on Nanocellulose-Assisted Aqueous Dispersions of Single-Wall Carbon Nanotubes
- Author
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Andreas Fall, Lars Wågberg, Fredrik Lundell, Karl Håkansson, Michaela Salajkova, Lars Berglund, Alireza Hajian, and Mahiar Hamedi
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chemistry.chemical_classification ,Nanocomposite ,Materials science ,Nanotubes, Carbon ,Electric Conductivity ,Nanofibers ,General Engineering ,Water ,General Physics and Astronomy ,Nanotechnology ,Polymer ,Carbon nanotube ,Exfoliation joint ,Nanocomposites ,Nanocellulose ,law.invention ,chemistry ,law ,Advanced composite materials ,General Materials Science ,Self-assembly ,Cellulose ,Dispersion (chemistry) ,Mechanical Phenomena - Abstract
It is challenging to obtain high-quality dispersions of single-wall nanotubes (SWNTs) in composite matrix materials, in order to reach the full potential of mechanical and electronic properties. The most widely used matrix materials are polymers, and the route to achieving high quality dispersions of SWNT is mainly chemical functionalization of the SWNT. This leads to increased cost, a loss of strength and lower conductivity. In addition full potential of colloidal self-assembly cannot be fully exploited in a polymer matrix. This may limit the possibilities for assembly of highly ordered structural nanocomposites. Here we show that nanofibrillated cellulose (NFC) can act as an excellent aqueous dispersion agent for as-prepared SWNTs, making possible low-cost exfoliation and purification of SWNTs with dispersion limits exceeding 40 wt %. The NFC:SWNT dispersion may also offer a cheap and sustainable alternative for molecular self-assembly of advanced composites. We demonstrate semitransparent conductive films, aerogels and anisotropic microscale fibers with nanoscale composite structure. The NFC:SWNT nanopaper shows increased strength at 3 wt % SWNT, reaching a modulus of 13.3 GPa, and a strength of 307 MPa. The anisotropic microfiber composites have maximum conductivities above 200 S cm(-1) and current densities reaching 1400 A cm(-2).
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- 2014
197. Molecular dynamics simulation of strong interaction mechanisms at wet interfaces in clay–polysaccharide nanocomposites
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Yaoquan Tu, Hans Ågren, Jakob Wohlert, Lars Berglund, and Yan Wang
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chemistry.chemical_classification ,Nanocomposite ,Materials science ,Renewable Energy, Sustainability and the Environment ,Nanotechnology ,General Chemistry ,Adhesion ,Polymer ,Molecular dynamics ,chemistry.chemical_compound ,Montmorillonite ,Adsorption ,Chemical engineering ,chemistry ,Molecule ,General Materials Science ,Material properties - Abstract
Bio-composites comprised of the polysaccharide xyloglucan (XG) and montmorillonite (MTM) clay has potential as a ‘green’ replacement of conventional petroleum-derived polymers in the packaging industry. These materials have been shown to possess excellent material properties, even in high relative humidity. Although interfacial interaction between XG and MTM, and the molecular structure of XG can be identified as key parameters for the complex formation process and the resulting tensile properties, these properties are usually difficult to address using experimental methods. Here we use molecular dynamics (MD) simulations to study the adsorption of fully atomistic models of both native and chemically modified XG to MTM clay surfaces in explicit water. We show that the driving force for adsorption is a favorable change in enthalpy, and furthermore that native XG adsorbs stronger than modified XG. This highlights the importance of molecular structure details to molecular adhesion. The present study provides insights into the molecular scale adsorption mechanisms and can therefore help in designing routes for further improvements of bio-composite materials.
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- 2014
198. Water-soluble hemicelluloses for high humidity applications – enzymatic modification of xyloglucan for mechanical and oxygen barrier properties
- Author
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Joby J. Kochumalayil and Lars Berglund
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chemistry.chemical_classification ,Polymer ,engineering.material ,Pollution ,Xyloglucan ,Hildebrand solubility parameter ,Oxygen permeability ,Oxygen transmission rate ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,engineering ,Environmental Chemistry ,Organic chemistry ,Relative humidity ,Biopolymer ,Solubility - Abstract
Bio-based polymers are of increasing interest in packaging applications as alternatives to petroleum-based polymers. Xyloglucan (XG) derived from tamarind seed waste was recently explored as a high performance biopolymer for packaging applications. Xyloglucan films have high strength, stiffness and oxygen barrier performance, but suffer from limitations in properties under high humidity conditions. This aspect is addressed in the present work using XG modification by enzymatic removal of side chain galactose residues. The modified XG was characterized using carbohydrate analysis and MALDI-TOF MS analysis for sugar and oligosaccharide compositions respectively. The consequence of galactose removal for XG chain packing was theoretically predicted using a group contribution method and the estimation of Hansen's solubility parameters. The properties of films made from modified XG in terms of tensile, oxygen transmission rate, and thermo-mechanical behaviour were measured and related to the structure of modified XGs. Modified XG films preserved the Young's modulus at high humidity at a level of 4.3 GPa at 92% relative humidity. Moreover, the oxygen permeability of modified XG samples was very low and was about 1.5 cc μm [m2 day]−1 kPa−1 at 80% relative humidity, more than 80% lower than that for native XG. The main reason is that modified XG absorbs less moisture, due to a decreased solubility. Decreased free volume may also contribute, as galactose residues are removed and XG branches become shorter.
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- 2014
199. Controlled deposition of magnetic particles within the 3-D template of wood: making use of the natural hierarchical structure of wood
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Valter Ström, Richard T. Olsson, Stacy Trey, Lars Berglund, and Mats Johansson
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Template ,Chemistry ,General Chemical Engineering ,technology, industry, and agriculture ,Magnetic nanoparticles ,Deposition (phase transition) ,Nanotechnology ,General Chemistry ,equipment and supplies ,complex mixtures ,human activities ,Nanomaterials - Abstract
Process of modifying wood veneer samples with metal salts to result in magnetic particle modified wood and images of the cross section of a wood sample lumen cell wall unmodified and modified with the deposition of magnetic particles.
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- 2014
200. Lipid Lowering with Soluble Dietary Fiber
- Author
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Prasanth Surampudi, Byambaa Enkhmaa, Lars Berglund, and Erdembileg Anuurad
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0301 basic medicine ,Dietary Fiber ,Glucose control ,030209 endocrinology & metabolism ,Inflammation ,Blood Pressure ,Health benefits ,Soluble dietary fiber ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Weight loss ,medicine ,Animals ,Humans ,Food science ,Lipoprotein cholesterol ,030109 nutrition & dietetics ,Triglyceride ,business.industry ,food and beverages ,Lipids ,chemistry ,Cardiovascular Diseases ,Lipid lowering ,medicine.symptom ,Cardiology and Cardiovascular Medicine ,business ,Risk Reduction Behavior - Abstract
Consumption of dietary soluble fibers has been associated with health benefits such as reduced lipid levels, lower blood pressure, improved blood glucose control, weight loss, improved immune function, and reduced inflammation. Many of these health benefits relate to a reduced risk of developing cardiovascular disease. In this paper, we have reviewed recent studies on the hypocholesterolemic effects of dietary soluble fibers as well as fiber-rich foods. Findings include the following: (a) consumption of water-soluble, viscous-forming fibers can reduce total and low-density lipoprotein cholesterol levels by about 5–10 %; (b) minimal changes of high-density lipoprotein cholesterol or triglyceride levels were observed; (c) cholesterol-lowering properties of soluble fibers depend on their physical and chemical properties; and (d) medium to high molecular weight fibers are more effective in reducing lipid levels. Hypocholesterolemic benefits were also observed with some fiber-rich foods, such as whole oats, whole barley, legumes, peas, beans, flax seeds, apples, and citrus foods.
- Published
- 2016
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