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In this paper, thermal buckling and free vibration of a rectangular plate reinforced with carbon nanotubes (CNT) are investigated within the framework of third-order shear deformation theory (TSDT). CNT distribution along the thickness direction of the plate is uniformly or functionally graded. The equivalent properties of the reinforced composite plate are calculated based on the extended rule of mixture. Governing equations of motion are derived using the Hamilton principle. Obtained governing differential equations are analyzed by utilizing Fourier series expansion along the longitudinal and latitudinal direction for simply supported edges boundary conditions whereas for other edges boundary conditions we used the differential quadrature method (DQM) to solve numerically. Validation of the present formulation is assessed by comparing the results with those reported in the open literature. The effect of CNT volume fraction, the different patterns of CNT distribution, temperature difference, aspect ratio, and thickness-to-length ratio on buckling and vibration behavior of carbon nanotube-reinforced composite (CNTRC) plate is studied. The numerical illustration reveals that in the FG-X pattern of CNT distribution natural frequency and thermal buckling load is more significant compared with the other patterns of CNT distribution. [ABSTRACT FROM AUTHOR]

The control problem of a three-degree-of-freedom (3-DOF) X-Z inverted pendulum as an unstable, multi-input-multi-output, under-actuated and high-order nonlinear system is facing many challenges. In this paper, a Fuzzy Adaptive Hierarchical Sliding-Mode Controller (FAHSMC) is optimally designed for the X-Z inverted pendulum system utilizing the Multi-Objective Genetic Algorithm (MOGA). To this end, at first, the state variables of this system are converted to the new state variables via five steps of a forward transformation process. In this transformation, the dynamical equations of the X-Z inverted pendulum system are reorganized to an appropriate form for control implementations. Then, the novel FAHSMC is designed for stabilization and tracking control of the system, and the stability analysis of the controller is proved via the Lyapunov stability theory. After that, the state and control variables of the X-Z inverted pendulum are computed through six steps of a backward transformation process. Ultimately, the MOGA is exerted for Pareto optimal design of the proposed control approach applied on the regarded X-Z inverted pendulum system. The tracking error of the cart position in the X-direction, the tracking error of the cart position in the Z-direction and the angle error of the pendulum are selected as three inconsistent objective functions for multi-objective optimization operations. Numerical results and diagrams illustrate that the proposed approaches can accurately converge the system states to the desirable trajectories in a short time and yield superior Pareto optimal fronts in comparison with the Hierarchical Sliding-Mode Controller (HSMC) and the Adaptive Hierarchical Sliding-Mode Controller (AHSMC). [ABSTRACT FROM AUTHOR]

The endohedral functionalization of carbon nanotubes (CNTs) with nanowires (NWs), i.e., NWs@CNTs, has been the center of attention in a lot of research due to the applications of NWs@CNTs in nanoelectronic devices, heterogeneous catalysis, and electromagnetic wave absorption. To this end, based on the classical molecular dynamics (MD) simulations, the effect of four pentagonal structures of encapsulated metallic nanowires (mNWs), namely the eclipsed pentagon (E), the deformed staggered pentagon (Ds), staggered pentagon (S), and staggered pentagonal structure without the monatomic chain passing through the centers of the parallel pentagons (R) configurations on the vibrational behavior of CNTs, is investigated. Also, the effects of geometrical parameters such as length and radius of CNTs on the natural frequencies of simulated models are explored. The results illustrate that by increasing the length, the natural frequency of pure CNTs and mNWs@CNTs decreases. In a similar length, mNWs@CNTs possess lower natural frequencies compared to the pure CNTs. According to the results, the highest and lowest natural frequencies are calculated by inserting the S structure of sodium NW and Ds structure of aluminum NW inside their proper armchair CNT, i.e., Na-S NW@ (9,9) CNT and Al-Ds NW@ (7,7) CNT, respectively. [ABSTRACT FROM AUTHOR]

Molecular dynamics (MD) simulations have been performed to determine the reinforcing role of two-dimensional (2D) nanosheets on Young's and shear moduli of nanosheet-strengthened polylactic acid (PLA). Various volume fractions of nanosheets in addition to different kinds of nanosheets, that is, graphene (GR), silicon carbide nanosheet (SiCNS), and boron-nitride nanosheet (BNNS), are regarded as affecting parameters on the mechanical response. Uniaxial tensile and shear tests are conducted and related stress–strain diagrams are achieved to be used for exploring mechanical properties. It is found that the incorporation of 2D nanosheets into PLA has a noticeable impact on the mechanical behavior of the polymer. In a desired percentage of volume fraction (${\rm v}_{\rm f}$ v f ), GR and SiCNS have performed the greatest and least roles in augmenting the mechanical properties of PLA nanocomposites, respectively. Compared to those, the reinforcing effect of the BNNS comes in between. Also, the results show that there is a growing trend in longitudinal and transverse Young's moduli (${\rm E}_{\rm x}$ E x and ${\rm E}_{\rm y}$ E y ) and the XY-plane shear modulus (${\rm G}_{{\rm xy}}$ G xy ) of nanocomposites as the ${\rm v}_{\rm f}$ v f of nanosheets increases. [ABSTRACT FROM AUTHOR]

Herein, the interfacial properties of new three-dimensional (3D) configurations of metallic carbon, namely T6 and T14, incorporated to different polymer matrices (T6 and T14@polymers) are studied using molecular dynamics (MD) simulations. The effects of two types of shape models for T6 and T14, i.e. beam- and plate-like models, various square cross-sectional areas for the reinforcements, pull-out velocity and polymer structure on the interaction energy and pull-out force of final system are investigated. The results reveal that the interfacial resistance of the system is improved by imposing a high pull-out velocity to the nanofillers. For each pull-out velocity, the effect of beam-like T6 and T14@polycarbonate (beam-like T6 and T14@PC) on increasing average pull-out force is more remarkable than that of similar models surrounded by polypropylene (PP). The beam- and plate-like structures@polymers possess the lowest and highest interfacial resistance, respectively. As the aspect ratio (length-to-width ratio) of nanofillers changes from the lowest value to the highest one, the average pull-out force decreases. The average pull-out force of plate-like T6@polymers is higher than their plate-like T14 counterparts. Besides, higher absolute values of interaction energy in plate-like T6 and T14@polymers in comparison with others imply that the load-carrying capacity from the surrounding matrix to the plate-like nanofillers is significantly increased. Image 1 • Studying the interfacial properties of T6 and T14 structures incorporated to different polymer matrices (T6 and T14@polymers) using MD simulations • Using two types of configurations for T6 and T14 (beam- and plate-like models) • Investigating effects of square cross-sectional areas for the reinforcements, pull-out velocity and polymer structure on the pull-out force and interaction energy [ABSTRACT FROM AUTHOR]

Information systems (ISs) are one of the most widely used systems in different organizations especially hospitals. Improving the performance of a hospital information system (HIS) is one of the most important tasks for patient satisfaction and health. To do this, a mixed sustainability-resilience framework for evaluating HISs is proposed in this study in order to enhance their performance from a mixed sustainability-resilience view. First, a comprehensive framework including suitable sustainable and resilience indicators for performance enhancement of HISs is provided. Then, the importance weight of each indicator is achieved by using the best-worst method (BWM). Required data is obtained through a standard questionnaire. A data envelopment analysis (DEA) is applied to evaluate HIS performance in different departments of a real case study. Additionally, improvement actions are obtained by considering the effect of each selected indicator on the HIS performance through a sensitivity analysis. Also, appropriate strategies for improving the resilience and sustainability aspects of the HIS are presented using strengths-weaknesses-opportunities-threats (SWOT) matrix. Using the results, designers can build more intelligent HISs from both sustainability and resilience perspectives. [ABSTRACT FROM AUTHOR]

Experimental investigation was conducted to measure the convective heat transfer coefficient and thermal performance of plate fins and plate cubic pin-fins heat sinks, under natural convection regime. The investigation was conducted for Rayleigh number from 8 × 10 6 to 9.5 × 10 6 and input heat of 10 W to 120 W. The fin spacing and fin numbers are varied between 5–12 mm and 5–9, respectively. The results demonstrated that plate cubic pin-fins heat sinks have lower thermal resistance and higher heat transfer, compared to plate fins heat sinks. Heat transfer enhancement of new-designed heat sinks is about 10–41.6% higher, compared to normal pin-fins. Increasing fin spaces in all types of studied heat sinks cause lower thermal resistance. But, increasing fin numbers does not cause better heat transfer. The best heat sink design was a plate cubic pin–fin heat sink with 7 fins and 8.5 mm fin spacing. Finally, empirical equations have been developed to correlate the average Nusselt number as a function of number of fin plates, fin spacing to height ratio as well as Rayleigh (and consequently Grashof) number. [ABSTRACT FROM AUTHOR]

Ti and Ti-TiB composite materials were produced by selective laser melting (SLM). Ti showed an α΄ microstructure, whereas the Ti-TiB composite revealed a distribution of needle-like TiB particles across an α-Ti matrix. Hardness ( H ) and reduced elastic modulus ( E r ) were investigated by nanoindentation using loads of 2, 5 and 10 mN. The results showed higher H and E r values for the Ti-TiB than Ti due to the hardening and stiffening effects of the TiB reinforcements. On increasing the nanoindentation load, H and E r were decreased. Comparison of the nanoindentation results with those derived from conventional hardness and compression tests indicated that 5 mN is the most suitable nanoindentation load to assess the elastic modulus and hardness properties. The wear resistance of the samples was related to their corresponding H/E r and H 3 /E r 2 ratios obtained by nanoindentation. These investigations showed that there is a high degree of consistency between the characterization using nanoindentation and the wear evaluation from conventional wear tests. [ABSTRACT FROM AUTHOR]

A group of Ti xNb 7Fe (x = 0, 1, 4, 6, 9, 11 wt.%) alloys was designed and produced by cold crucible levitation melting process. The microstructural characteristic of the alloys with Nb addition and its effect on their mechanical properties as well as wear resistance were investigated. Microscopic and phase analysis results show that all the alloys, except for the Ti 11Nb 7Fe, exhibit orthorhombic α“ and body-centred cubic β phases, while Ti 11Nb 7Fe alloy consists of only β phase. It is proposed that increasing the Nb content enhances β phase stability and its proportion in the microstructure of the designed alloys. Depending on the proportion of β and α” phases, Ti xNb 7Fe alloys show varied hardness (3.57–5.92 GPa) and compressive strength (1990–2093 MPa). Additionally, they present wear rates in the range of 3 × 10 − 15 –1 × 10 − 13 m 3 /m which correlates well with the changes in the corresponding microstructures and mechanical properties. Among the studied alloys, Ti 11Nb 7Fe with β phase microstructure, presents the lowest elastic modulus (86 GPa) and the highest compressive strain (41.5%) along with high compressive strength, hardness and wear resistance. Therefore, it is suggested that this β-type Ti 11Nb 7Fe alloy is a promising candidate, more suitable than the commercially used CP Ti and Ti 6Al 4V, for orthopedic applications. [ABSTRACT FROM AUTHOR]

This paper proposes a novel hybrid BSC-DEA framework for performance evaluation in sustainable supply chains. The proposed DEA model is capable of dealing with both qualitative and quantitative indicators while accounting for desirable and undesirable indicators. A tailored network DEA model involving a set of comprehensive sustainability indicators is applied to rank different supply chains from sustainability viewpoint to find the efficient and benchmarked units at each echelon. Then, sustainability indicators are classified into four groups according to BSC perspectives to help policy makers and top managers to have a more comprehensive and thorough understanding of the sustainability with respect to the long- and short term strategies. Finally, a number of sensitivity analyses are performed to identify the effective factors and strengths and weaknesses of each supply chain are identified based on BSC perspectives. To demonstrate the capabilities of the proposed approach, this framework is implemented for performance evaluation of plastic recycling companies in Mazandaran and Golestan provinces of Iran and some helpful managerial insights are derived from the numerical results. [ABSTRACT FROM AUTHOR]

This study presents an integrated approach for analyzing the impact of macro-ergonomics factors in healthcare supply chain (HCSC) by data envelopment analysis (DEA). The case of this study is the supply chain (SC) of a real hospital. Thus, healthcare standards and macro-ergonomics factors are considered to be modeled by the mathematical programming approach. Over 28 subsidiary SC divisions with parallel missions and objectives are evaluated by analyzing inputs and outputs through DEA. Each division in this HCSC is considered as decision making unit (DMU). This approach can analyze the impact of macro-ergonomics factors on supply chain management (SCM) in healthcare sector. Also, this method ranks the relevant performance efficiencies of each HCSC. In this study by using proposed method, the most effective macro-ergonomics factor on HCSC is identified as "teamwork" issue. Also, this study would help managers to identify the areas of weaknesses in their SCM system and set improvement target plan for the related SCM system in healthcare industry. To the best of our knowledge, this is the first study for macro-ergonomics optimization of HCSC. [ABSTRACT FROM AUTHOR]

A two-stage molecular dynamics (MD)-finite element (FE) modeling method is developed based on the concepts of representative volume element (RVE) and equivalent solid fibers (ESFs) containing functionalized carbon nanotubes (ESFs-fCNTs). First, the influences of nanotubes' chirality, different percent of functionalization ( P func ), various functional atoms, and polymers on the tensile and shear properties of the fCNTs inserted into the polymer matrix (fCNTs/polymer) are discovered using MD simulations. Then, using MD information as input data, the effective Young's modulus of polymeric unit cell strengthened by ESFs-fCNTs (ESFs-fCNTs/polymer) is explored through FE modeling. The ratio of effective Young's modulus of the unit cell ( E UC ) to Young's modulus of the polymeric cube ( E P ) is reported and all findings ( E UC E P ) are compared to the ESFs-pure CNTs/polymer results as well. It is found that longitudinal Young's modulus ( E x ) of nanofillers/polymer RVEs affects remarkably the E UC E P of the ESFs-nanofillers/polymer nanocomposites. The E x decreases by increasing the P func. Generally, the reinforcing impact of zigzag nanotubes compared to armchair ones on the E x of polymer RVEs is more considerable. Additionally, FE-based results illustrate that as the volume fraction of ESFs ( v f ESF ) increases, the E UC E P is enhanced. At a specific P func , the reinforcing effect of the ESFs-armchair and zigzag fCNTs is more in favor of polyethylene nanocomposites than that of the polypropylene systems. [ABSTRACT FROM AUTHOR]

This paper introduces an approach based on stochastic data envelopment analysis (SDEA) for performance assessment of electricity distribution units. A new approach is applied for assessment of Iranian distribution units from 2001 to 2011 in this paper. There are usually incomplete and stochastic data or lack of data with respect to electricity distribution companies. Due to lack of information about some parameters, theory of probability is imported to the model. Different Iranian distribution units are considered as decision making units (DMUs). Network length, transport capacity and the number of employees are chosen as inputs while number of customers and total electricity sales are chosen as stochastic outputs. Then, the best electricity distributions units are selected with respect to efficiency scores in stochastic environment. Also, SDEA model is performed for each input, separately to identify the most important input indicators by comparing the results of associated efficiencies with SDEA model. The empirical results show that network length is the most important and influential input factor in this particular case study. To the best of our knowledge this is the first paper that examines stochastic outputs for assessment of electricity distribution units by SDEA in Iran. [ABSTRACT FROM AUTHOR]

This work aimed to investigate the effect of Fe and Ta contents on the β → α″ martensitic transformation as well as the microstructure and mechanical properties of the as-cast designed Ti– x Fe– y Ta ( x = 8, 9, 10 wt% and y = 0, 2, 5, 8, 9, 10 wt%) alloys. The microstructure of all alloys substantially consists of β and α″ phases. However, the addition of more Fe and Ta β-stabilizers to Ti–8Fe alloy reduced the likelihood to form α″ martensite during quenching, hence decreasing the volume fraction of α″ phase and finally reaching 3% in Ti–10Fe–10Ta alloy. The microstructural studies results revealed that except for Ti–8Fe and Ti–9Fe–2Ta, all alloys with high Ta content present a dendritic microstructure. It is noteworthy noting that all alloys possess higher Vickers hardness and compressive yield stress values than those of CP-Ti and Ti–6Al–4V. However, Ti–10Fe–10Ta alloy with the least amount of α″ martensite phase and dominant β phase structure exhibits the lowest elastic modulus and highest plasticity. It was concluded that further decrease in modulus of elasticity can be achieved through stabilizing single β phase by designing composition of Ti–Fe–Ta alloy. [ABSTRACT FROM AUTHOR]

Introduction: Peptic ulcer disease (PUD) is representative of a group of ulcerative disorders of the upper gastrointestinal tract, mainly involving the stomach and duodenum. Free radicals and oxidative stress have been proposed to be involved in the pathogenesis of peptic ulcer. To inactivate reactive oxygen species cells biosynthesize several antioxidant enzymes, one of which is catalase which converts H2O2 to H2O and O2. Objectives: This study aimed to examine an association of Catalase -262C>T polymorphism with PUD. Materials and Methods: The study included 84 patients with PUD and 70 healthy individuals. Genomic DNA was isolated from bioptic tissues. Genotype and allele frequencies were determined in patients and controls using Tetra-Primer ARMS-PCR. Statistical analysis was performed using the MedCalc program. Results: The prevalence of genotype frequencies of the CC, CT and TT in patients with PUD were %35.7, %41.6 and %22.6, respectively, while in healthy volunteers were %71.4, %21.4 and %7.1, respectively. Statistical analysis indicated a significant association between the polymorphism of catalase and peptic ulcer disease (P=0.0001). Conclusion: The presence of the T allele at position -262 C>T catalase gene might be as a risk factor for PUD in the study population. However, further studies of CAT polymorphism are needed to understand the role of CAT gene polymorphisms in the development of PUD. Conflict of interest: non declared [ABSTRACT FROM AUTHOR]

Diabetic retinopathy (DR) is the most common microvascular complication of diabetes and the leading cause of blindness in industrialized countries. Oxidative stress plays an important role in the development of microangiopathic complications in diabetes. Manganese superoxide dismutase (MnSOD) is a key mitochondrial antioxidant enzyme in the cellular defense against agents that induce oxidative stress. The aim of the present study was to assess whether the MnSOD A16V (C47T) polymorphism is associated with Diabetic retinopathy in northern Iran. 140 patients with Diabetic retinopathy and 140 healthy individuals, aged 30 to 75 years old, participated in this study. For genotyping of the MnSOD A16V polymorphism the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was used. The prevalence of genotype frequencies AA, AV, VV in Diabetic retinopathy subjects were 5.71, 71.43 and 22.86%, respectively, while in controls they were 21.43, 38.57 and 40%, respectively. A significantly increased frequency of the AV genotype was observed in patients as compared with controls (OR = 6.94, 95% CI = 2.98-16.20, P < 0.0001). In conclusion, it is suggested that the MnSOD A16V polymorphism may be associated with the risk of Diabetic retinopathy in northern Iran. However, larger population-based studies are needed for clarifying the relation between Diabetic retinopathy and the MnSOD A16V polymorphism. [ABSTRACT FROM AUTHOR]

In this paper, the free vibration of hybrid carbon boron-nitride heteronanotubes (CBNNTs) is analyzed through molecular dynamics (MD) simulations. In the vibration analysis, various CBNNTs (C x ∣ (BN) y and C-BN models) according to two geometrical arrangements of constituent segments are considered. By introducing vacancy defects in nanotubes, the influence of defects on the vibrational response is studied in terms of the weight percentage and distribution pattern. The highest vibration frequency is reported and CBNNTs' results are compared with those of carbon nanotubes (CNTs) and boron-nitride nanotubes (BNNTs). It is observed that CBNNTs possess natural frequencies which lie between the values for CNTs and BNNTs. The natural frequency is found to be reduced by increasing the defect percentage. At each defect percentage, the defective C-(BN) model I and C 1.5 ∣ (BN) 1.5 experience almost the same natural frequency in both distribution patterns. Vibration frequencies of defective C-(BN) model II and C 4.5 ∣ (BN) 4.5 are nearly close together at a defined percentage of defects. Despite the minor differences between natural frequencies in either distribution pattern, regularly defected CNTs tend to have a bit higher frequency than randomly defected CNTs, however, the results are opposite in the regularly and randomly defected BNNTs. Moreover, the C-(BN) model II vibrates at a higher natural frequency than that of the C-(BN) model I. It is found that the vibrational behavior of the C-(BN) model I is mostly affected by the BN segment than the C segment. Further, the natural frequency's drop in the defected C 1.5 ∣ (BN) 4.5 is found to be more significant than other CBNNTs by rising the defect percentage. C-(BN) model I and defective C-(BN) model I experience higher deformations in comparison with the C x ∣ (BN) y configurations when vibrating at their natural frequency. [Display omitted] • Vibrations of hybrid CBNNTs are analyzed using MD simulations. • Vacancy defects are considered in the analysis. • Natural frequencies of CBNNTs are between those of CNTs and BNNTs. • Natural frequency is decreased by introducing the defect sites. [ABSTRACT FROM AUTHOR]

Introduction: Different studies on evaluation of the outcome of multiple trauma patients have found many influential factors. The aim of this study was to determine the relationship of axilary body temperature with mortality in patients with multiple traumas hospitalized in the intensive care units and other clinical and paraclinical factors. Materials and Methods: This is a cohort study. All the patients between 16 and 75 years old with multiple traumas who were admitted to the ICU of Rasoul Akram Hospital from 21st of March 2008 till 20th of March 2009 were included in the study. Axillary temperature in the first and 2nd days of admission, Glasgow cola scale (GCS), systolic blood pressure, serum glucose levels and white blood cell counts of all patients at the first day were recorded and their relationships with each other and with the outcome were analyzed. Results: 93 patients were included in the study. Axillary body temperature in the first and second days showed a statistically significant relationship with mortality and GCS. Lower body temperature was led to an increase in mortality, less GCS and systolic blood pressure. Conclusion: Our results show that axillary body temperature in the first day of multiple trauma patients can be a reliable indicator of their final outcome. Patients with higher body temperature will experience better outcome than those with lower body temperature. [ABSTRACT FROM AUTHOR]

Highlights: [•] A mathematical model was developed to describe naphtha thermal cracking. [•] A comparison between mathematical and plant data show an acceptable agreement. [•] The diluting media changed to carbon dioxide and the model was run with CO2. [•] Using carbon dioxide enhances production yields and decrease coke deposition. [•] Using CO2 increases the run length of reactor from 80 to 100 days. [Copyright &y& Elsevier]

Abstract: A proportion of healthy siblings of multiple sclerosis (MS) patients have an oligoclonal immunological reaction in their cerebrospinal fluid (CSF) termed the “MS oligoclonal trait”. The CSF levels of the major myelin glycosphingolipid sulfatide and serum antibodies against the glycosphingolipids sulfatide and galactosylceramide were recently reported to be increased in MS patients. We studied the levels of these substances in pairs of 46 patients and their 46 healthy siblings and 50 unrelated healthy blood donors (HBD). The sulfatide concentration in CSF was assayed by thin layer chromatography and immunostaining, and the concentration of galactosylceramide by densitometry after thin layer chromatography. Anti-glycosphingolipid antibody levels were assayed by ELISA. In the healthy siblings, the CSF sulfatide concentrations were markedly increased (p<0.001, age adjusted p=0.025), and the serum IgM anti-GalCer antibodies were increased in healthy siblings compared with HBD (p=0.02). The increased sulfatide or antibody levels did not co-segregate with the “MS oligoclonal trait” or the HLA-DR15 phenotype. In conclusion, a proportion of healthy siblings of MS patients have increased CSF sulfatide and anti-glycosphingolipid antibody levels, which may, analogous to the “MS oligoclonal trait”, constitute an “MS glycosphingolipid endophenotype”. Endophenotypes could potentially simplify the genetics of complex disorders. [Copyright &y& Elsevier]

Abstract: In present work, ethylene and hydrogen production is investigated through thermal cracking of ethane in domestic petrochemical plant. In the thermal cracking process, a mixture of ethane and steam is introduced into radiant tubes located vertically in a furnace. The use of steam is mainly due to the partial removal of coke which has undesirable effects on the process. The coke deposition along the tubes causes high pressure drops and also reduction in production yield. In this study, the ethane thermal cracking process of this company is modeled and solved numerically. A comparison between model results and experimental data shows that the model can predict the process accurately. In addition, the effects of using carbon dioxide instead of steam are investigated on coke deposition. According to the results of two cases, the thermal cracking process in presence of CO2 is superior to the conventional process because of higher ethylene and hydrogen productions and less coke thickness. The simulation results reveal that the run length of the reactor in presence of CO2 becomes as twice as the one in presence of steam. [Copyright &y& Elsevier]

Nano-ZnO is reported as an extremely efficient heterogeneous catalyst for the synthesis of tetrahydrobenzo[b]pyrans. A three-component one-pot reaction of arylaldehydes, activated methylenes, and 1,3-diketones took place in water to afford the corresponding tetrahydrobenzo[b]pyrans in good to high yields in the presence of nano-ZnO. Furthermore, the catalyst could be reused for several times without any significant loss of its catalytic activity. [ABSTRACT FROM AUTHOR]

Haghighi S, Lekman A, Nilsson S, Blomqvist M, Andersen O. Myelin glycosphingolipid immunoreactivity and CSF levels in multiple sclerosis. Acta Neurol Scand: 2012: 125: 64-70. © 2011 John Wiley & Sons A/S. Objectives - Patients with multiple sclerosis were reported to harbour antibodies not only against proteins and glycoproteins but also against glycolipids, including sulfatide and galactosylceramide (GalCer), the two major glycosphingolipids of myelin. However, previous results were inconsistent concerning glycosphingolipid levels, antibody type, dominance of serum or Cerebrospinal fluid compartments and relationship to the multiple sclerosis (MS) course. Results - We hereby report that the cerebrospinal fluid levels of sulfatide were increased in patients with MS ( n = 46) compared with controls ( n = 50, P < 0.001). In addition, patients had higher serum IgM anti-glycosphingolipid titres than controls ( P = 0.03 for sulfatide, <0.001 for GalCer), while the anti-glycosphingolipid IgM antibodies in the cerebrospinal fluid were essentially normal. However, in seven of 46 patients cerebrospinal fluid IgG antibodies against GalCer ( P = 0.004) could be detected, which was not found in any of the control individuals, and this finding might mirror the occurrence of more specific B-cell clones behind the blood-brain barrier. Conclusions - The IgM immunoreactivity in serum did not show any relationship to the type of course or severity of MS, arguing against a phenomenon secondary to myelin damage. Thus, the IgM antibody findings are compatible with an early antigen challenge or autoimmunity associated with natural antibodies. [ABSTRACT FROM AUTHOR]

Although aminoglycosides antibiotics are used in children and adult commonly, they have serious side effects such as nephrotoxicity and ototoxicity. In clinical practice, for renal function, the levels of serum creatinine and blood urea nitrogen routinely are measured. Since these parameters have limitations such as unreliability, insensitivity, and nonspecificity, the rapid assessment of renal function based on these patients is very important. Increase in N-acetyl-β-D-glucosaminidase (NAG), a hydrolytic lysosomal enzyme, suggests proximal tubular cell damage. In this study, 32 children aged 2 months through 2 years, treated with gentamicin and amikacin for suspected infections at the pediatric ward of Alborz hospital from September 2006 to February 2007, were enrolled. Serum and fresh urine before and after drug infusion were obtained on the 1st, 3rd, and 5th days of antibiotic treatment. Serum urea and creatinine with urinary creatinine, albumin, NAG, lactate dehydrogenase (LDH) and alkaline phosphatase (AP) activity were then determined. A statistically significant increase in urinary NAG, LDH, and AP on 5th day was found compared with before gentamicin administration (P < 0.001, P < 0.01, P < 0.05, respectively). The urinary NAG activity may be a useful indicator of renal injury in children treated with aminoglycosides drugs compared with other routine clinical indicators. [ABSTRACT FROM AUTHOR]

We analysed HLA haplotypes in pairs of 78 sporadic multiple sclerosis (MS) patients and 78 healthy siblings. The presence of 2 oligoclonal IgG bands, detected by immunoblotting of the cerebrospinal fluid in healthy siblings, has previously been defined as MS immunopathic trait (MSIT), based on a cut-off derived from healthy unrelated volunteers. The frequency of MSIT was 17.9% (n=14/78 siblings). The HLA-DR(15)2 allelle was present in 21.4% (n=3/14) of the siblings with MSIT, in 40.6% (n=26/64) of the siblings without MSIT, and in 59% (n=46/78) of the patients with clinically-definite (CD) MS. The distribution of zero, one or two HLA-DR(2)15 alleles was significantly skewed towards a lower allelle count in the siblings with MSIT compared with the group of unrelated siblings with MS (P=0.002), and also lower than their related siblings with MS (P=0.1). These results suggest that the MS susceptibility gene, HLA-DR(2)15 type, does not induce MSIT, and conceivably these are two separate risk factors in the development of MS. The effect of HLADR( 2)15 and MSIT in sporadic MS appears to be synergistic. [ABSTRACT FROM AUTHOR]

We studied two extended families in which not only multiple sclerosis (MS) segregates, but also approximately 18% of the cerebrospinal fluid (CSF) investigated blood relatives have 'MS immunopathic trait', an oligoclonal CSF immunopathy similar to that seen in MS, but with no neurological symptoms. Both families fit a genetic model for autosomal dominant inheritance for MS immunopathic trait, although with reduced penetrance in family A. In order to identify genetic factors of importance for the development of MS immunopathic trait, we performed a genome scan using the CHLC/Weber Screening Set (ver 6A), with 285 successful markers, to test the hypothesis that a single gene is causing the MS immunopathic trait in these families. Using a parametric method, we identified regions with suggestive linkage at chromosome 6q12 with a LOD-score of 2.4, putative linkage with LOD-score 1.5 at chromosome 6p21 (HLA region), putative linkage at chromosome 12q24 with a LOD-score of 1.7 and suggestive linkage at chromosome 19q13.2 with a LOD-score of 1.8. The LOD-score at chromosome 19q13.2 increased to 2.2 when only family A was analysed. In family A, all MS patients and two of five individuals with MS immunopathic trait had HLA DRB1*(15) and in family B, all blood relatives had the rare HLA type DRB1*0103, which is associated with other autoimmune diseases. We suggest that DRB1*0103 is a necessary but not sufficient condition for the susceptibility for MS immunopathic trait in this family. [ABSTRACT FROM AUTHOR]

Haghighi S, Frisén L, Odén A, Andersen O. Multiple sclerosis siblings with cerebrospinal fluid immunopathy but without any indication of neuronal damage. Acta Neurol Scand 2003 DOI: 10.1046/j.1600-0404.2003.00130.x © Blackwell Munksgaard 2003. In a previous study, we found that nine of the 47 siblings to multiple sclerosis (MS) patients with a normal neurologic examination carry an intrathecal oligoclonal immunopathy with limited specificity, a condition we termed MS immunopathic trait. Here we searched for neurological dysfunction with increased sensitivity. We used high-pass resolution perimetry, which reveals visual pathway lesions by their impaired neural effective capacity (EC) in early MS cases even without optic neuritis. These nine individuals with MS immunopathic trait did not differ from nine healthy controls with normal cerebrospinal fluid regarding their EC. This is further evidence that a group of MS immunopathic trait individuals, siblings to MS patients, are essentially free from the central nervous system functional loss typically found in MS. [ABSTRACT FROM AUTHOR]

STUDY DESIGN:: A case report of psychogenic paraplegia following a motor vehicle accident was clinically diagnosed using median (MN) and posterior tibial nerves (PTN) somatosensory evoked potentials (SSEPs). OBJECTIVE:: To report an unusual case of paraplegia in spite of normal electrophysiological and non-compromising radiographic spine findings. SUMMARY OF BACKGROUND DATA:: Conversion disorder with motor system symptoms or deficit is a subtype which includes symptoms such as impaired motor coordination or balance, paraplegia, muscle weakness, difficulty in swallowing, and urinary retention. METHODS:: The SSEPs were performed by each PTN at the ankle region behind the medial malleolus or the MN at the wrist using square wave pulses in 15 mA intensity. The SSEPs revealed well-developed somatosensory peaks for all extremities. RESULTS:: Well-resolved MN-SSEPs were seen with stimulation of either arm. The principal peaks of N20 and P22 were 17 and 21 ms for both upper extremities. The principal peaks of P37 and N45 were 35 and 46 ms for both lower extremities. No side-to-side latency difference was noted. The MRI scan finding was a non-displaced L1 fracture without spinal canal compromise. CONCLUSIONS:: In spite of an apparent paraplegia, contradictory clinical findings, normal neurophysiologic tests, and normal neuroradiologic findings are positive criteria for paraplegia/quadriplegia with psychogenic etiology.Spinal Cord (2001) 39, 664–667. [ABSTRACT FROM AUTHOR]

STUDY DESIGN:&EMSP;:An experimental study was conducted to evaluate the effects of methylprednisolone and MK-801 after the compressive injury of spinal cord in rats. OBJECTIVES:&EMSP;:To investigate the effect of methylprednisolone and non-competitive NMDA antagonist MK-801 in long-term functional outcome after spinal cord injury (SCI). METHODS:&EMSP;:A randomized group A of Sprague-Dawley rats were treated with MK-801 (1.0 mg/kg, n=10; Group A) after a compression injury. A group of methylprednisolone (MP)-treated (30 mg/kg, n=10; Group B) and non-treated animals (n=9; Group C) were included for comparison. The functional motor outcome such as inclined plane (IP), toe spreading reflex (TSR), and modified Tarlov scale (TS) were measured in each animal at regular time points up to 8 weeks post-treatment. Histologically the injury site was scored in four groups and immunohistochemically Wallerian Degeneration (WD), astrocytosis and expression of β-amyloid protein was identified. RESULTS:&EMSP;:In examining the IP data, no significant difference was recognized between the group means (P-value>0.5). For the TSR, there were no differences in the group responses. For the TS, the differences were not statistically significant. Only group B showed significance in cavitation scores compared to group A (P>0.0094), WD was significantly different than group C (P>0.03), astrocytosis was significantly higher than group A (P>0.001) and modest presence of β-amyloid protein. CONCLUSION:&EMSP;:Our data indicate that one time bolus administration of MK-801 lacks any significant effect on axonal function in chronically injured rats. Daily bolus administration of MP at 30 mg/kg also did not ensure a better functional outcome. Immunohistochemically we have been able to show significant differences in WD, astrocytosis and small insignificant changes in β-amyloid protein.Spinal Cord (2000) 38, 733–740. [ABSTRACT FROM AUTHOR]

The tensile properties and fracture mechanism of hydroxyl-functionalized silicon carbide nanotubes (O-fSiCNTs) inserted into polymer matrices are explored and the outcomes are compared to results for the hydroxyl-functionalized carbon nanotubes (O-fCNTs) incorporated in similar matrices. The molecular dynamics (MD) method is used and the simulations are based on the notion of representative volume elements (RVEs). The incorporation of chemisorbed nanotubes in polymers has a profound effect on the enhancement of their mechanical properties. The O-fSiCNTs inside the polyethylene (PE) and polypropylene (PP) (O-fSiCNTs/PE and O-fSiCNTs/PP) possess lower Young's modulus, maximum stress, and strain energy as compared to the O-fCNTs/PE and O-fCNTs/PP. The zigzag O-fSiCNTs/polymer experiences lower bearable maximum strains in response to imposed loads in comparison with the O-fCNTs/polymer which is opposite to what occurs in the armchair O-fSiCNTs and O-fCNTs/polymer. The more the functionalization degree is, the weaker the structure is and its stiffness, tensile strength, tolerable strain before fracture, and ability to absorption of internal energy decline. Not only are the zigzag O-fSiCNTs/polymer stiffer than the armchair O-fSiCNTs/polymer in every percent of functionalization, but also as compared to the armchair ones, they show a lower decrease in the variation of Young's modulus with increasing the functionalization percentage. [ABSTRACT FROM AUTHOR]

Haghighi S, Andersen O, Odén A, Rosengren L. Cerebrospinal fluid markers in MS patients and their healthy siblings. Acta Neurol Scand 2003 DOI: 10.1046/j.1600-0404.2003.00197.x © Blackwell Munksgaard 2003. In a previous study we found that nine of 47 siblings to multiple sclerosis (MS) patients with a normal neurological examination carry an intrathecal oligoclonal immunopathy with limited specificity, a condition we termed MS immunopathic trait. The purpose of this study is to further characterize the MS immunopathic trait phenotype. We found that the neurofilament light protein (NFL) and glial fibrillary acidic protein (GFAp) concentrations were increased in the group of patients with clinically definite MS ( n = 47) in latent or slowly progressive phases. There was no increase in GFAp and NFL in cerebrospinal fluid in the healthy siblings of MS patients ( n = 47), nor in the subgroup of these siblings with MS immunopathic trait ( n = 9) compared with a group of healthy control subjects ( n = 50). Thus, there was no indication of presymptomatic CNS parenchymal involvement in MS immunopathic trait. [ABSTRACT FROM AUTHOR]

The average pull-out force and interaction energy of polyethylene (PE) cross-linked functionalized carbon nanotubes (cfCNTs) embedded in polymer matrices (PE-cfCNTs@polymers) was studied using molecular dynamics (MD) simulations. Accordingly, the pull-out process of PE-cfCNTs from inside polymer matrices, i.e., Aramid and PE, was performed under displacement control. The results obtained were compared with those of pure carbon nanotube (CNT) incorporated into polymer matrices (pure CNT@polymers). The influence on the pull-out force and interaction energy between the CNT and polymer of the structure of polymer matrices, the weight percentage and two types of distribution patterns of cross-linked PE chains, namely mapped and wrapped, was investigated. The results indicate that the structure of the polymers and distribution patterns of cross-linked PE chains strongly affect important parameters related to interfacial properties. The average pull-out force of mapped and wrapped PE-cfCNTs@polymers increases as the weight of attached PE chains on the CNT surface increases. The effect of wrapped structures on increasing the pull-out force is greater than that of the mapped configurations. Also, the PE-cfCNTs@polymers show higher average pull-out forces than those of their pure counterparts. As the CNT pulls out from the polymer matrix, an approximately linear reduction in the absolute value of interaction energy with the pull-out displacement is observed. However, this trend is changed to some extent by imposing instability through the wrapped PE-cfCNTs. [ABSTRACT FROM AUTHOR]

Commercially pure titanium, as a widely used metallic biomaterial, was fabricated using dissimilar additive manufacturing (AM) methods, namely selective laser melting (SLM), laser engineered net shaping (LENS) and wire arc additive manufacturing (WAAM). Microstructures as well as mechanical and wear properties of the produced titanium samples were studied. Diverse microstructural features were related to the different linear energy densities and cooling rates induced by each AM method. Tensile testing evaluation indicated the highest yield and ultimate tensile strengths as well as elastic energy for titanium produced by SLM. However, the maximum ductility was obtained in the WAAM-fabricated titanium due to its larger grain size and slightly higher densification. All the mechanical properties obtained were either superior or comparable to those of cast and powder metallurgy produced titanium. Fracture surface analysis showed the presence of mainly coarse and fine dimples for WAAM and SLM-produced samples, respectively. This was consistent with the grain size of each sample. Wear performances and mechanisms were also examined and the results were in agreement with the values obtained from the hardness to elastic modulus ratios (H/E and H 3 /E 2 ). [ABSTRACT FROM AUTHOR]

This paper presents a unique intelligent algorithm to identify and optimize factors affecting the productivity of upstream oil projects. Oil industry is the most important economic sector in the world and upstream projects play an important role in this industry. The proposed algorithm is composed of analysis of variance (ANOVA), data envelopment analysis (DEA), artificial neural network (ANN), adaptive network based fuzzy inference system (ANFIS), conventional regression (CR), and fuzzy regression (FR). In addition, each stage of the algorithm is equipped with verification and validation mechanism. First, a standard questionnaire containing productivity factors is designed and completed by experts of actual upstream oil projects. Then, DEA is used to identify the weights of all influential factors. The relationships between the influential factors and each of the criteria of productivity are then evaluated by ANN, ANFIS, CR and FR through relative error. Finally, ANFIS is selected as the preferred methods for optimization of the actual case of this study according to mean absolute error (MAE). Health, safety and environment (HSE), economic and management are determined as the most influential factors through sensitivity analysis. This is the first study that presents an intelligent algorithm for determination and optimization of productivity factors in an actual upstream oil projects. It can be used as a continuous improvement solution for upstream oil projects. [ABSTRACT FROM AUTHOR]

A correction to the article "'Nano-ZnO as Heterogeneous Catalyst for Three-component One-pot Synthesis of Tetrahydrobenzo pyrans in Water" in the December 2012 issue is presented which apologizes for the error in the name of the second author in the said article.

A simple, efficient and environmentally benign three-component one-pot synthesis of tetrahydrobenzopyran derivatives is developed. [ABSTRACT FROM AUTHOR]

The buckling behavior of cross-linked functionalized carbon nanotubes (CNTs) with polyethylene (PE) chains under physical adsorption of polymers (cfCNTs/polymer) is studied by classical molecular dynamics (MD) simulations, and the results are compared with those for the pure CNTs under the physical adsorption of polymers. Considering non-covalent functionalization, the effect of type of functional group, i.e. aramid and PE chains, on the interactions between polymers and cfCNTs is investigated. Based on the results, the gyration radius of cfCNTs/polymer increases by raising the weight percentage of non-covalent polymer chains. Also, the simulation results for most cases demonstrate that the gyration radius of cfCNTs/polymer is larger than that of pure CNTs/polymer for the similar weight percentage of non-covalent polymer chains. Moreover, the critical buckling force and the critical buckling strain of the cfCNTs/polymer are lower than those of pure CNT/polymer for the similar weight percentage of non-covalent polymer chains, although some exceptions can be observed. Besides, by raising the weight percentage of non-covalent polymer chains, the critical buckling force cfCNTs/polymer increases for a specific weight percentage of cross-linked PE chains. [ABSTRACT FROM AUTHOR]

Fabrication of novel metallic and stable three-dimensional (3D) forms of carbon, i.e. T6 and T14, has recently attracted a lot of interest due to their various potential applications. In the present work, the vibrational behaviors of T6 and T14 with interlocking hexagons are studied via molecular dynamics (MD) simulations. The natural frequencies and mode shapes of T6 and T14 are obtained for beam- and plate-like models. Moreover, the effects of different geometrical parameters such as length, width and cross-sectional area on the vibrational behaviors of these nanostructures are investigated. Also, the natural frequency of models is compared to that of single-walled carbon nanotubes (SWCNTs) with relatively similar dimensions. The results indicate that the natural frequency is strongly sensitive to the geometry, especially in the models with shorter lengths. Furthermore, it is observed that the natural frequency of 3D metallic carbon nanostructures is smaller than that of SWCNTs. [ABSTRACT FROM AUTHOR]

Reactive oxygen species (ROS) play a critical role in peptic ulcer disease (PUD). Due to the high rate of ROS production and limited capacity for DNA repair within mitochondria, mtDNA is susceptible to oxidative damage and mutations. mtDNA deletion Δ4977 is one of the most common deletion events identified in mitochondria. We examined the association of 4977-bp mtDNA deletion with PUD. Genotypes were determined in bioptic samples of 150 PUD patients and 190 controls. The 4977-bp mtDNA deletion was found more frequently among patients with PUD (52%) than among controls (22.63%). The strong association between the mtDNA 4977-bp deletion and PUD was confirmed (OR = 3.7; 95% CI, 2.32-5.91; P = 0.0001). The 4977-bp deletion in mitochondrial DNA may be a risk factor for PUD, or may reflect an increase in oxidative stress that commonly accompanies underlying PUD disease. Larger population-based studies are needed to uncover the possible causal relationship between this deletion and peptic ulcer disease. [ABSTRACT FROM AUTHOR]

Economic crisis have created certain challenges for large factories. This has intensified the need for being resilient in face of such disruption. During economic crisis, factories are faced with significant threats in their financial performance and survivorship. In this paper, the performance of an aluminum production plant has been investigated by integrated resilient engineering (IRE). For assessing IRE performance in economic crisis of the case of this study, first a questionnaire based on IRE factors in context of economic crisis is distributed among all expert managers and staff. Afterwards, the Cronbach’s alpha test is used to investigate the reliability of the questionnaire’s data. Then, best fitted data envelopment analysis (DEA) is used to examine resilience engineering factors in context of economic crisis performance. To validate and verify the results, principle component analysis (PCA) and numerical taxonomy (NT) are utilized. It is found that self-organization, reporting culture, flexibility and learning have the greatest effect on performance. Also, it is shown that integrated resilient engineering is more efficient than resilient engineering. It is proven that the aluminum factory can be more resilient in cases of economic crisis by improving the above factors. The framework of this study may be used for all types of industrial units to identify the most important resilient factors in times of economic crisis. This is the first study that presents an integrated framework for performance optimization of an aluminum factory in economic crisis. [ABSTRACT FROM AUTHOR]

Nonlinear thermo free vibration and instability of viscose fluid-conveying double-walled carbon nanocones (DWCNCs) are studied using Hamilton's principle and differential quadrature method (DQM). The small-size effects on bulk viscosity and slip boundary conditions of nanoflow through Knudsen number (Kn) is considered. The nanocone is simulated as a clamped-clamped Euler-Bernoulli's beam embedded in an elastic foundation of the Winkler and Pasternak type. The van der Waals (vdW) forces between the inner and outer nanocones are taken into account. The detailed parametric study is conducted, focusing on the combined effects of the nonlocal parameter, apex angles, aspect ratio, temperature change, fluid viscosity, boundary conditions and the elastic medium coefficient on the dimensionless frequency and critical fluid velocity of DWCNCs. The results show that the small-size effect on flow field is remarkable on frequency and critical fluid velocity of DWCNC. Also, the nonlinear frequency and critical flow velocity decrease with increasing the nonlocal parameter and cone semi-vertex angle. The results are in good agreement with the previous researches. [ABSTRACT FROM AUTHOR]

Background Cell and animal experiments have shown that β-site APP-cleaving enzyme 1 (BACE1) may be involved in myelination. Objective Here, we assess the association of cerebrospinal fluid (CSF) BACE1 activity with multiple sclerosis (MS). Methods BACE1 activity and levels of secreted amyloid precursor protein (APP) and amyloid-β (Aβ) isoforms were analyzed in CSF from 100 patients with MS and 114 neurologically healthy controls. Patients with systemic lupus erythematosus (SLE), 26 with and 41 without cerebral engagement, were also included to enable comparisons with regards to another autoimmune disease. A subset of patients with MS and controls underwent a second lumbar puncture after 10 years. Results MS patients had lower CSF BACE1 activity than controls (P = 0.03) and patients with cerebral SLE (P < 0.001). Patients with cerebral SLE had higher BACE1 activity than any other group (P < 0.05 for all comparisons). BACE1 activity correlated with the different amyloid markers in all study groups. BACE1 activity decreased over 10 years in the MS group (P = 0.039) and correlated weakly with clinical disease severity scores in an inverse manner. Conclusions These results suggest an involvement of BACE1 in the MS disease process. [ABSTRACT FROM AUTHOR]

The mechanical characteristics of reinforced polymer nanocomposites with Hydrogen (H)- and Fluorine (F)-functionalized silicon carbide nanotubes (H-and F-fSiCNTs) are investigated herein using molecular dynamics (MD) simulations. The effects of covalent functionalization and chirality of SiCNT, and diverse polymer materials on Young's modulus, maximum stress, and strain to the failure point, as well as strain energy are studied. The results reveal that by increasing the functionalization degree, the maximum stress, maximum strain, elastic modulus, and strain energy decrease. The tensile strength of polymer nanocomposites containing SiCNT is higher than that of pure polymer and polymers containing functionalized silicon carbide nanotubes (fSiCNTs). It is also found that the incorporation of fSiCNT into the polymer matrix (fSiCNT/polymer) gives rise to a considerable improvement in the ultimate strength of nanocomposites compared to the pure polymer. Polymer nanocomposites reinforced by armchair SiCNTs and fSiCNTs withstand higher maximum stresses and possess less longitudinal Young's modulus as compared to the same systems comprising zigzag nanotubes. In every percent of functionalization, the zigzag F-fSiCNT/polymer tends to have a higher Young's modulus as compared to the zigzag H-fSiCNT/polymer. Similarly, the armchair F-fSiCNTs incorporated into the polyethylene (PE) matrix (F-fSiCNTs/PE) are stiffer than the armchair H-fSiCNTs/PE in each weight of functionalization. Moreover, the armchair fSiCNTs/polymer nanocomposites show higher storage of strain energy in comparison with their zigzag counterparts. [Display omitted] • Mechanical properties of H- and F-fSiCNTs incorporated inside polymer matrices are studied using MD simulations based on the concept of RVE unit cells. • Effects of chemical functionalization of reinforcements, nanotube's chirality and polymer type on the mechanical properties are investigated. • Armchair SiCNT@polymer experiences higher maximum stresses before rupturing than zigzag SiCNT@polymer. • Young's modulus of zigzag fSiCNTs@polymer is obtained more than that of armchair ones. • The peak strain of the armchair fSiCNT@PE and fSiCNT@PP are larger than that of zigzag counterparts in every desired P func. [ABSTRACT FROM AUTHOR]

Abstract: In this study the cold pressure welding between the aluminum powder and internal surface of aluminum tube was evaluated. The aluminum powder was compacted into the aluminum tube using the punch. The bond shear strength between the green compact disc and internal surface of tube at different amount of normal pressure of compaction was investigated. The effect of pressure on the cold bonding between the green compact disc and the inner surface of aluminum tube was investigated by SEM. The results of this study indicate that the discontinuity regions at the interface of the green compact disc and the inner surface of aluminum tube decreased and the bond shear strength increased with increasing compact pressure. [Copyright &y& Elsevier]

Abstract: Biological markers would provide valuable tools for tracking disease activity, immunopathological processes or therapeutic efficacy in MS. In this study we analysed a panel of Th1/Th2 cytokines and the chemokine CCL2 in serum and CSF from MS patients and healthy controls. Increased levels of IL-6 (p <0.05) and decreased levels of CCL2 (p <0.001), with the lowest levels during acute relapses, was found in CSF from patients with relapsing–remitting MS. CSF levels of CCL2 correlated with indices for intrathecal IgG production and the CSF level of the neurofilament light protein, a marker for axonal damage, indicating a immunopathogenic role for CCL2. [Copyright &y& Elsevier]

Molecular dynamics (MD) simulations are used to investigate the tensile properties and fracture behavior of Hydrogen (H)- and Fluorine (F)-chemisorbed single-walled silicon carbide nanotubes (SWSiCNTs). Stress-strain curves are obtained and Young's modulus, toughness, tensile strength, as well as maximum strain of nanotubes are determined through stress-strain profiles. The results are compared to those of single-walled carbon nanotubes (SWCNTs) and a detailed analysis of the tensile fracture behavior of both nanotubes, i.e., SWSiCNTs and SWCNTs, is made. It is found that the functionalized nanotubes possess lower stress and strain at the breaking point than those of their pure counterparts (SWSiCNTs 0% and SWCNTs 0%). The increase of functionalization weight leads to reduced Young's modulus, toughness, and tensile strength. Concerning fluorination and hydrogenation, the fluorination of nanotubes has less influence on the weakening of Young's modulus in every functionalization degree when the findings of F-functionalized SWSiCNTs and SWCNTs (F-fSWSiCNTs and F-fSWCNTs) are compared to those of pure nanotubes. Fluorinated and hydrogenated armchair SWSiCNTs experience a nearly equal value of toughness in each weight of functionalization. Similar results are seen in the zigzag fSWSiCNTs which means that the absorption ability of strain energy in the zigzag H- and F-fSWSiCNTs is almost the same. As the weight of functionalization increases from the minimum value to the maximum one, the variation of ultimate stress with the degree of functionalization for the H-fSWCNTs and zigzag H-fSWSiCNT undergoes more reduction in comparison with their F-functionalized counterparts. Also, the armchair functionalized nanotubes are proved to be more capable of withstanding a larger fracture strain than that of their zigzag counterparts in each desired weight of functionalization. Regarding the fracture behavior of nanotubes, the rupture propagation tends to happen in a benzene ring that has at least three functional atoms and one of its grafts has been broken before. [Display omitted] • Maximum stress and strain of CNTs and fCNTs are larger than those of SiCNTs and fSiCNTs. • Young's modulus, toughness and tensile strength decrease as degree of functionalization increases. • Armchair fSWSiCNTs are tougher than zigzag fSWSiCNTs. • Effects of chemical functionalization with H and F atoms on toughness of SiCNTs are approximately similar. • Armchair SiCNTs and CNTs possess larger ultimate stress and strain as compared to zigzag ones. [ABSTRACT FROM AUTHOR]

Abstract Young's modulus and the fracture of gold nanowires (GNWs) encapsulated inside single-walled carbon nanotubes (SWCNTs) are studied using molecular dynamics (MD) simulations. To investigate the mechanical behavior, two important parameters, i.e. ultimate tensile force and strain, are calculated. The obtained results from aforementioned nanostructures are compared with those of pure GNWs and SWCNTs. The results illustrate that SWCNTs filled with GNWs (GNWs@SWCNTs) and pure GNWs possess lower Young's moduli than those of pure SWCNTs in a similar length. As the length increases, Young's modulus of pure GNWs and GNWs@SWCNTs is reduced. In a particular length, the highest and lowest ultimate forces belong to the multishell GNWs@SWCNTs and pure multishell GNWs, respectively. Moreover, it is found that pure SWCNTs have the highest ultimate strains. Also, by rising the length, the ultimate tensile strain increases. To study the effect of selected boundaries on the tensile characteristics, the tensile loads are applied to the boundaries of surrounding SWCNTs instead of whole configuration (B model). The obtained results demonstrated that in the similar length, Young's modulus and ultimate force for B model are higher than those of A model, i.e. the model that the whole system is under the tensile loads. By contrast, in the particular length, B model shows lower ultimate strain compared to that of A model. Graphical abstract Unlabelled Image Highlights • Studying Young's modulus and fracture of GNWs@ SWCNTs by MD simulations • Calculating ultimate tensile force and strain • Considering effects of length and various cross-sectional area of GNWs • Comparing the results with those of pure GNWs and SWCNTs [ABSTRACT FROM AUTHOR]