2,804 results on '"alternative methods"'
Search Results
2. Air–Liquid Interface Exposure of Lung Epithelial Cells to Low Doses of Nanoparticles to Assess Pulmonary Adverse Effects
- Author
-
Silvia Diabaté, Lucie Armand, Sivakumar Murugadoss, Marco Dilger, Susanne Fritsch-Decker, Christoph Schlager, David Béal, Marie-Edith Arnal, Mathilde Biola-Clier, Selina Ambrose, Sonja Mülhopt, Hanns-Rudolf Paur, Iseult Lynch, Eugenia Valsami-Jones, Marie Carriere, and Carsten Weiss
- Subjects
cerium dioxide ,zirconium-doping ,titanium dioxide ,nanotoxicology ,alternative methods ,Chemistry ,QD1-999 - Abstract
Reliable and predictive in vitro assays for hazard assessments of manufactured nanomaterials (MNMs) are still limited. Specifically, exposure systems which more realistically recapitulate the physiological conditions in the lung are needed to predict pulmonary toxicity. To this end, air-liquid interface (ALI) systems have been developed in recent years which might be better suited than conventional submerged exposure assays. However, there is still a need for rigorous side-by-side comparisons of the results obtained with the two different exposure methods considering numerous parameters, such as different MNMs, cell culture models and read outs. In this study, human A549 lung epithelial cells and differentiated THP-1 macrophages were exposed under submerged conditions to two abundant types of MNMs i.e., ceria and titania nanoparticles (NPs). Membrane integrity, metabolic activity as well as pro-inflammatory responses were recorded. For comparison, A549 monocultures were also exposed at the ALI to the same MNMs. In the case of titania NPs, genotoxicity was also investigated. In general, cells were more sensitive at the ALI compared to under classical submerged conditions. Whereas ceria NPs triggered only moderate effects, titania NPs clearly initiated cytotoxicity, pro-inflammatory gene expression and genotoxicity. Interestingly, low doses of NPs deposited at the ALI were sufficient to drive adverse outcomes, as also documented in rodent experiments. Therefore, further development of ALI systems seems promising to refine, reduce or even replace acute pulmonary toxicity studies in animals.
- Published
- 2020
- Full Text
- View/download PDF
3. Non-thermal atmospheric pressure plasma: An alternative method to enhance the seed quality in long bean-KPN (Vigna unguiculate L.) seeds
- Author
-
Bandula Ranaweera, D.A.S. Amarasinghe, Thisara Sandanuwan, Malki Lalanka, Sampath Weragoda, Kamani Ratnayake, Nayanathara Hendeniya, and Dinesh Attygalle
- Subjects
Alternative methods ,Vigna ,Horticulture ,Control specimen ,biology ,Germination ,Chemistry ,food and beverages ,Plasma treatment ,Atmospheric-pressure plasma ,General Medicine ,biology.organism_classification ,Quality enhancement - Abstract
Non-thermal atmospheric pressure plasma treatment has emerged as a promising potential seed quality enhancement method over recent years. This study focuses on the effect of atmospheric pressure plasma treatment on seed germination and growth of Long Bean-KPN (Vigna unguiculata L.) seeds under laboratory conditions. In this study, the Long Bean seeds were exposed to a dry air non-thermal atmospheric pressure plasma for different periods between 4 and 10 min to study its effect on seed germination and growth behavior. It was observed that Germination percentage and Seed Vigor Index were negatively affected by plasma treatment for more than 6 min. The performance of seeds treated for 4 min had a slight improvement in germination over the control specimen, while it showed a significant improvement in average seed vigor index. The study confirmed that non-thermal atmospheric pressure plasma treatment can be stimulatory for seed germination and growth of Vigna unguiculate L. seeds if exposed to plasma for periods less than 4 min and it can be inhibitory for the purpose if exposure time exceeds 6 min.
- Published
- 2022
- Full Text
- View/download PDF
4. Friction stir cladding of copper on aluminium substrate
- Author
-
Adarsh Kumar, Mohd Zaheer Khan Yusufzai, Mithlesh Kumar Mahto, Meghanshu Vashista, and Avinash Ravi Raja
- Subjects
Alternative methods ,Materials science ,chemistry ,Aluminium ,chemistry.chemical_element ,Friction stir welding ,Substrate (electronics) ,Composite material ,Cladding (fiber optics) ,Copper ,Indentation hardness ,Layer (electronics) ,Industrial and Manufacturing Engineering - Abstract
Thick cladding of copper is required for diverse applications, however, only a handful of processes can be used for bulk material cladding. This study has been undertaken to suggest a better alternative method for cladding thick layer of copper on aluminium substrate. Cladding of 3 mm thick layer of copper on 6 mm thick aluminium substrate has been successfully performed using friction stir welding process (FSW). Detailed microscopic study, XRD and microhardness evaluation of the samples proved the quality of clad layer. Interestingly even after three FSW passes no substrate material could reach near the top of clad layer.
- Published
- 2022
- Full Text
- View/download PDF
5. Ruminal Degradability and Bypass Nutrients of Alkaline or Steam-Treated Cassava Chip and Corn Grain
- Author
-
Chantira Wongnen, Wuttikorn Srakaew, C. Wachirapakorn, and A. Cherdthong
- Subjects
Alternative methods ,General Veterinary ,cassava chips ,Starch ,food and beverages ,Treatment method ,Carbohydrate ,SF1-1100 ,CORN GRAIN ,Animal culture ,corn grain ,chemistry.chemical_compound ,Animal science ,Nutrient ,chemistry ,steam treatment ,Animal Science and Zoology ,NaOH treatment ,bypass starch ,Chemical composition ,Completely randomized design - Abstract
Modification of starches in high-energy feeds using various treatment methods led to the diverse effects on ruminal degradation and bypass protein and starch. Thus, the objectives of the present experiment were to investigate the effects of modification methods applied to high-starch energy feed sources on ruminal degradability and bypass nutrients determined using in situ and in vitro gas production techniques. This experiment was designed using a 2×4 factorial arrangement in a completely randomized design (CRD). The first factor was high-starch energy feed consisted of two levels, i.e., corn grain and cassava chips. The second factor was the treating method consisted of four levels, i.e., no treatment, steam treatment, NaOH treatment, and steam with NaOH treatment. Chemical composition, ruminal in situ disappearance, bypass of crude protein (CP) and non-fiber carbohydrate (NFC), and gas production characteristics were measured in pre-treated and post-treated samples. The results showed that significant interactions (p0.05) in cassava chips and corn grain. DMD, ED, and EP of treated cassava chips were lower, while bypass CP and bypass NFC of treated cassava chips were higher than untreated cassava chips (p
- Published
- 2021
- Full Text
- View/download PDF
6. Vineyard weed control using alternative methods compared to glyphosate-based herbicide
- Author
-
Mario Lešnik, Nuša Turk, and Andrej Paušič
- Subjects
Alternative methods ,vinograd ,Field experiment ,Agriculture ,Biology ,Weed control ,Vineyard ,law.invention ,herbicidi ,chemistry.chemical_compound ,pleveli ,Animal science ,chemistry ,law ,Glyphosate ,Yield (wine) ,stroški ,ožiganje ,General Agricultural and Biological Sciences ,Weed ,košnja ,Essential oil ,Water Science and Technology - Abstract
In a two-year field experiment, six different weed control methods were studied. The methods were: use of the herbicide glyphosate (GL), use of herbicides based on acetic acid (AA), pelargonic acid (PA) and citrus essential oil (EO), mowing weeds with a thread trimmer (TT) and flaming of weeds with fire (FL). Alternative methods of weed control were significantly less effective than the use of herbicide glyphosate. Due to the lower efficiency of alternative methods, large yield losses have occurred, on average, 31 % at AA, 30.6 % at PA, 22.7 % at EO, 5.4 % at TT and 12.9 % at FL in two years. The cost of carrying out controls with alternative methods was significantly higher than the cost of GL. AA it was higher by 3.2-times, in PA by 7.1-times, in EO by 3.8-times, in TT by 3.8- times and in FL by 5.8-times on average in two years. To achieve a comparable control efficiency of GL, five applications of alternative preparations per year have to be performed, or four times mowing of weeds or five weed flaming operations per year.
- Published
- 2021
7. Field Validation of a Non-logging Alternative Method for the Prediction of the Location of Water-Cresting in Horizontal Wells for Water-Drive Reservoirs
- Author
-
Li Lifeng, Joseph Y. Fu, Xiang'an Yue, and Lijuan Zhang
- Subjects
Alternative methods ,Horizontal wells ,Field (physics) ,General Chemical Engineering ,Soil science ,General Chemistry ,Article ,Water production ,Wellbore ,Chemistry ,Permeability (earth sciences) ,Trajectory ,QD1-999 ,Geology ,Pressure gradient - Abstract
A previously reported method for a non-logging alternative method for the prediction of the location of water-cresting in horizontal wells for water-drive reservoirs is validated in a field test for the first time in this study. Using this method, the wellbore trajectory, variation in the reservoir permeability, and the pressure gradient data were used to calculate what is called the breakthrough coefficient for the different segments along the length of a set horizontal well with the largest calculated breakthrough coefficient corresponding to the most likely location of the actual water-cresting occurrence. This method was field-validated and found to be in good agreement with log testing for a group of seven wells in an oilfield in Northern China. Another calculated parameter derived from the breakthrough coefficient which is called the variation of the breakthrough coefficients that characterize the effect of the variation of water production along the length of the horizontal well due to the effect of the variation of the wellbore trajectory, permeability, and pressure gradient on the oil production is also introduced. This field validation found variation of the breakthrough coefficients to be weakly and inversely correlated to the oil production in application to a group of 27 wells in the same field.
- Published
- 2021
- Full Text
- View/download PDF
8. Microwave Assisted Reduction for Screening Banned Aromatic Amines in Azo Dyes
- Author
-
Munawwer Rasheed, Sarwat Jahan Mahboob, Muhammad Kashif Pervez, Kehkashan Khan, Farman Ahmed, and Rajkumar Dewani
- Subjects
Reduction (complexity) ,Alternative methods ,Sodium dithionite ,Green chemistry ,Absorbance ,chemistry.chemical_compound ,Materials science ,chemistry ,Spectroscopy ,Microwave assisted ,Reduction methods ,Nuclear chemistry - Abstract
The study proposes a simple, novel and green alternative for the efficient reduction of azo dyes by the standard method, EN 14362-1:2012 (Annex. F) for detection of harmful aromatic amines in colorants, by incorporating microwave heating in place of convective heating. Basic dye response to reduction methods was explored by UV-visible spectroscopy and the results were confirmed through GC-MS and HPLC-DAD. Four azo dyes namely Acid red 1 (AR-1), Direct blue 15 (DB-15), Direct red 28 (DR-28) and Direct red 7 (DR-7) were reduced with sodium dithionite at 70 °C for 30 min in a buffered solution at pH 6.0, serving as a reference method. The decline in dye absorbance after their reduction was explored by UV-visible spectroscopy with carefully chosen bands of maximum absorbance from 300 to 700 nm. The alternative method exposed dye solutions to short microwave heating (10 s) and immediate cooling, in cycles till the desired duration of microwave heating was achieved. Results obtained from reference method were used for comparison with MAR (experimental method 1). Most prominent results of MAR were observed in the case of DR-28 dye. Hence DR-28 was further subjected to the conditions of experimental method 2, which was simply EN 14362-1:2012 (F) method modified with MAR. For standard method and experimental method 2, amines were analysed by GC-MS and HPLC-DAD. MAR methods were compared with reference and standard reduction methods for efficiencies. The total saving with MAR in terms of time and energy was ~70% and ~92% respectively.
- Published
- 2021
- Full Text
- View/download PDF
9. Does microwave disinfection affect the dimensional stability of denture base acrylic resins? A systematic review
- Author
-
Rodrigo Moreira Bringel da Costa, Joel Ferreira Santiago Júnior, Ana Paula Chappuis-Chocano, Helena Sandrini Venante, Vinícius Carvalho Porto, Mariana Domingues Pordeus, and Karin Hermana Neppelenbroek
- Subjects
Denture Bases ,medicine.medical_treatment ,Acrylic Resins ,Dentistry ,Chemical disinfection ,chemistry.chemical_compound ,Materials Testing ,medicine ,Humans ,Microwaves ,General Dentistry ,Acrylic resin ,Alternative methods ,business.industry ,Chlorhexidine ,REVISÃO SISTEMÁTICA ,Disinfection ,chemistry ,visual_art ,Sodium hypochlorite ,visual_art.visual_art_medium ,Denture base ,Geriatrics and Gerontology ,Dentures ,business ,Microwave ,medicine.drug - Abstract
OBJECTIVE To systematically evaluate the effect of microwave disinfection on the dimensional stability of denture base acrylic resins. BACKGROUND Microwave disinfection has been considered as an alternative method for disinfecting complete dentures to help prevent and treat denture stomatitis. However, data on the impact of microwave disinfection on the dimensional stability of acrylic resins are still scarce. METHODS The PubMed/Medline, SCOPUS and EMBASE databases were searched in order to assess articles published in English up to January 2021 (CRD42021212267). We included studies that have assessed the effect of microwave disinfection, on the dimensional stability of acrylic resins, comparing them with negative or positive controls. RESULTS A total of seven in vitro studies were included. The qualitative synthesis demonstrated that, in general, microwave disinfection produced more distortion on the materials than do immersion in sodium hypochlorite, chloride solution, chlorhexidine, and water immersion. However, considering the dimensional stability of the specimens, microwave disinfection at 500 W for 3 minutes, and at 450 W for 5 minutes, produced similar or better outcomes than did control groups. CONCLUSION In general, microwave disinfection promotes changes in the dimensional stability of denture base acrylic resins, and should thus be used with caution. However, microwave disinfection protocols at lower power settings (500 and 450 W) and exposure times (3 and 5 minutes) produces similar or less distortion than chemical disinfection. More studies are still required in order to evaluate the clinical and long-term implications of microwave disinfection.
- Published
- 2021
- Full Text
- View/download PDF
10. Recent Applications of the Huynh Electronic Parameter (HEP)
- Author
-
Han Vinh Huynh
- Subjects
Alternative methods ,Metal ,13c nmr spectroscopy ,Chemistry ,Ligand ,Computational chemistry ,visual_art ,visual_art.visual_art_medium ,General Chemistry - Abstract
The Huynh electronic parameter (HEP) is a modern alternative method to determine ligand donor strengths by 13C NMR spectroscopy of metal NHC complexes containing the ligand of interest. Using the H...
- Published
- 2021
- Full Text
- View/download PDF
11. Ozone as an alternative method to control postharvest diseases on apples
- Author
-
Pierre-Yves Cotter, S. Gabioud Rebeaud, and Danilo Christen
- Subjects
Alternative methods ,chemistry.chemical_compound ,Horticulture ,Ozone ,chemistry ,Postharvest ,Environmental science - Published
- 2021
- Full Text
- View/download PDF
12. An efficient and metal-free synthesis of 5,7-dimethylcyclopentenon[2,3-c]coumarin
- Author
-
Thirupathi Reddy Yerramreddy and Alexandros Yiannikouris
- Subjects
Alternative methods ,chemistry.chemical_classification ,chemistry.chemical_compound ,Aflatoxin ,chemistry ,Metal free ,Molecularly imprinted polymer ,General Chemistry ,Polymer ,Molecular imprinting ,Coumarin ,Combinatorial chemistry - Abstract
An improved and alternative method for the metal-free synthesis of 5,7-dimethylcyclopentenon[2,3- c]coumarin as a possible useful aflatoxin template in the production of molecular imprinting polymers with affinity toward natural aflatoxin molecules is reported. A synthesis of 5,7-dimethylcyclopentenon[2,3- c]coumarin from 3,5-dimethoxyphenol via a Pechmann condensation involved five steps and represents an alternative commercially viable approach over existing synthetic protocols in the literature. Operational simplicity, inexpensive key raw materials, short reaction times, and excellent yields are remarkable features of this approach. The aflatoxin template was provided in 55%–67% overall yield from 3,5-dimethoxyphenol with >99% purity, evaluated by high-performance liquid chromatography, 1H NMR, 13C NMR, high-resolution mass spectrometry, and liquid chromatography–mass spectrometry.
- Published
- 2021
- Full Text
- View/download PDF
13. An Environmentally Friendly Method for the Identification of Microplastics Using Density Analysis
- Author
-
Symiah Barnett, Robert Evans, Belén Quintana, Guido Pietroluongo, and Anastasia Miliou
- Subjects
chemistry.chemical_classification ,Alternative methods ,Microplastics ,business.industry ,Health, Toxicology and Mutagenesis ,Polymer ,Environmentally friendly ,Identification (information) ,chemistry ,Density analysis ,Environmental Chemistry ,Environmental science ,Process engineering ,business ,Analysis method - Abstract
Current methodologies for microplastic polymer identification such as Fourier-transform infrared and differential scanning calorimetry are neither cost-efficient nor practical in fieldwork. Density analysis is an inexpensive and readily transportable alternative method. However, current density analysis methods use many different hazardous solutions to carry out separation and identification of plastics. We demonstrate the use of water, sucrose, and ethanol solutions for the density analysis of microplastics. The method developed was able to successfully distinguish between and identify 8 polymers commonly found in microplastic pollution. Environ Toxicol Chem 2021;40:3299-3305. © 2021 SETAC.
- Published
- 2021
- Full Text
- View/download PDF
14. Biotechnological methods for the production of ginsenosides
- Author
-
Arpita Roy, Soumya Pandit, Ritika Luthra, and Ram Prasad
- Subjects
0106 biological sciences ,chemistry.chemical_classification ,Alternative methods ,business.industry ,Plant Science ,Biology ,01 natural sciences ,Suspension culture ,0104 chemical sciences ,Biotechnology ,010404 medicinal & biomolecular chemistry ,chemistry ,Callus ,Hairy root culture ,business ,Literature survey ,Short duration ,010606 plant biology & botany ,Triterpenoid saponin - Abstract
Demand for compounds from natural sources are increasing day by day. Ginsenosides are secondary metabolites, belonging to triterpenoid saponin groups which are present in Panax species. Ginsenosides possess wide range of therapeutic activities which includes anti-aging, anti-oxidative, anti-cancerous, etc. Cultivation of plants containing ginsenosides requires a long duration of time, ranging from five to seven years, along with extensive efforts for controlling the quality despite of the unfavorable environmental conditions. Isolation and production of ginsenosides is also time-consuming and not feasible, when exploiting the conventional methods. Therefore, an alternative method is required for its enhanced production. Biotechnological methods such as shoot culture, cell suspension culture, root culture and hairy root culture are largely being executed for enhanced production of ginsenosides. Bioreactors are also utilized for scaling up the production of ginsenosides. Therefore, this review provides a comprehensive information about pharmaceutical applications of ginsenosides, different biotechnological approaches (shoot, root, hairy root and callus/cell suspension culture) that are used for the production of ginsenosides and scale up strategies for large scale production. Information about different in vitro systems has also been compiled after a panoramic literature survey and last twenty years data has been taken into consideration for this review.
- Published
- 2021
- Full Text
- View/download PDF
15. Treating protracted corneal ulcers with UVA corneal collagen crosslinking: clinical cases
- Author
-
E. V. Yani, E. N. Iomdina, V. V. Pozdniakova, V. A. Golikova, and K. E. Seliverstova
- Subjects
medicine.medical_specialty ,Visual acuity ,genetic structures ,ultraviolet crosslinking ,chemistry.chemical_compound ,Cornea ,Ophthalmology ,medicine ,Process outcome ,New device ,Fluorescein ,Alternative methods ,treatment ,business.industry ,RE1-994 ,corneal ulcer ,medicine.disease ,eye diseases ,Clinical Practice ,medicine.anatomical_structure ,chemistry ,sense organs ,medicine.symptom ,business ,device for local corneal collagen crosslinking - Abstract
It has recently been proposed to use ultraviolet (UVA) corneal collagen crosslinking as an alternative method of treating bacterial ulcerative lesions of the cornea. Ambivalent results regarding the efficacy and safety of this method of treatment limit its implementation in clinical practice so far.The purpose of this work is to analyze three clinical cases involving the use of a new device for local UVA crosslinking in the complex treatment of bacterial corneal protracted-course ulcers with the suspected development of mixed fungal infection.Material and methods. For a dynamic follow-up of patients, we used biomicroscopy with a fluorescein test, photo registration and optical coherence tomography of the anterior part of the eye. Inflammatory changes were assessed using a point scale.Results. 3–5 procedures of local UVA exposure (with instillations of 0.1% riboflavin solution) lasting 3–5 minutes each and given with an interval of 2–4 days ensured stable and fast epithelialization of the cornea and a significant increase in visual acuity in the inflammatory process outcome.Conclusion. The first results of treating bacterial corneal ulcers using a new portable device for local UVA crosslinking have shown its high therapeutic efficiency and good prospects for further use in clinical practice.
- Published
- 2021
16. Complete intra-laboratory validation of a LAL assay for bacterial endotoxin determination in EBV-specific cytotoxic T lymphocytes
- Author
-
Francesca Timoneri, Maria Concetta Niotta, Davide Sottile, Mariangela Di Bella, Bruno Douradinha, Chiara Di Bartolo, Giuseppina Di Martino, Danilo D'Apolito, Salvatore Pasqua, Monica Miele, Pier Giulio Conaldi, and Nicola Cuscino
- Subjects
endotoxins ,Pharmacology ,QH426-470 ,law.invention ,Microbiology ,chemistry.chemical_compound ,EBV-Specific Cytotoxic T-Lymphocyte ,failure mode and effects analysis ,law ,Genetics ,Medicine ,Potency ,qualification ,Molecular Biology ,ATMPs ,FMEA ,Alternative methods ,QH573-671 ,business.industry ,Chemistry ,Limulus amebocyte lysate ,GMP ,Correction ,advanced therapy medicinal products ,method validation ,LAL ,good manufacturing practices ,Molecular Medicine ,Original Article ,Bacterial endotoxin ,Pharmacopoeia ,ATMP ,business ,Cytology ,Intra-laboratory - Abstract
Endotoxin content is a critical factor that affects the safety of biological pharmaceutical products. International pharmacopoeias describe several reference methods to determine endotoxin levels in advanced therapy medicinal product (ATMP) preparations. Administration of ATMPs must be done as rapidly as possible to ensure complete viability and potency of the cellular product. To evaluate the endotoxin content in the shortest time possible, we chose to validate an alternative method based on the use of the Charles River Portable Testing System (PTS) and FDA-approved cartridges, compliant with the requirements of the European Pharmacopoeia and providing results in, Graphical abstract, Endotoxin assessment is crucial to ensure that ATMP administration to patients can be done as soon and as safely as possible. The use of PTS allows us to obtain fast, robust, and reproducible results, and its application simplifies the related procedures in a time- and money-saving manner.
- Published
- 2021
17. The Art of Inducing Hypoxia
- Author
-
Helen Rinderknecht, Sabrina Ehnert, Tina Histing, Caren Linnemann, Bianca Braun, and Andreas K. Nussler
- Subjects
Alternative methods ,chemistry.chemical_classification ,hypoxia induction ,hematoma ,chemistry.chemical_element ,Inflammation ,Bone healing ,Hypoxia (medical) ,bone ,fracture healing ,Oxygen ,cytokines ,In vitro ,Cell biology ,Enzyme ,chemistry ,Cell culture ,medicine ,medicine.symptom - Abstract
Many cells in the human body strongly react on decreased oxygen concentrations, generally defined as hypoxia. Therefore, inducing hypoxia in vitro is essential for research. Classically, hypoxia is induced using a hypoxia chamber, but alternative methods exist that do not require special equipment. Here, we compared three different methods to induce hypoxia without a hypoxia chamber: the chemical stabilization of HIF-1α by CoCl2, the decrease in pericellular oxygen concentrations by increased media height, and the consumption of oxygen by an enzymatic system. Hypoxia induction was further analyzed within three different cell culture systems: 2D (adherent) osteoprogenitor cells, monocytic (suspension) cells, and in a 3D in vitro fracture hematoma model. The different methods were analyzed within the scope of fracture healing regarding inflammation and differentiation. We could show that all three induction methods were feasible for hypoxia induction within adherent cells. Increased media heights did not stimulate a hypoxic response within suspension cells and in the 3D system. Chemical stabilization of HIF-1α showed limitations when looking at the expression of cytokines in osteoprogenitors and monocytes. Enzymatic reduction of oxygen proofed to be most effective within all three systems inducing inflammation and differentiation.
- Published
- 2021
- Full Text
- View/download PDF
18. Application and utility of alternative methods in isolation of pure cells from forensic biological mixtures in modern-day: a review
- Author
-
Priyanka Kshirsagar, Maya S Nair, P Jayakrishna, Suneel Prajapati, Mukul Meshram, and Poonam Rajmane
- Subjects
Alternative methods ,Isolation (health care) ,Chemistry ,Biochemical engineering - Abstract
Development of genetic profiles from the biological mixtures has remained challenging, although modern-day technologies may help forensic scientists to attain a reliable genetic profile in the identification of the accused. In the case of rape, vaginal swab exhibits usually contain epithelial cells of victims and sperm cells of accused, such samples are more challenging when there is more than one contributor. In such cases, separation of distinct cells from a mixture that includes blood cells, epithelial cells and sperm cells for their single genetic profile is important. In the last ten decades several new techniques were developed and invented for the separation of single cell from the biological mixture that includes differential lysis, laser micro-dissection, cell sorting (FACS), sieve-based filtration, (vi) micro-fluidic devices or immunomagnetic beads cell separation of fresh samples, and the magnetic activated cell sorting (MACS). Out of them, some techniques have been commonly applied for cell separation in forensic biology. Each technique has its own limitation. Some recent studies showed, magnetic activated cell sorting (MACS), laser capture microdissection (LCM), DEPArray technology and fluorescence activated cell sorting (FACS) has proved to be effective in separation of single cell from cell mixtures. Therefore, in this review we have evaluated these four alternative methods and their potential application in the modern-day over the others for the separation of a single cell from the mixture. In this review we also discuss the advantage of these methods and their modern–day applicability and acceptance in the forensic world.
- Published
- 2021
- Full Text
- View/download PDF
19. Comparison of feather mercury concentrations in live-caught vs. found-dead chick carcasses of Gentoo Penguins (Pygoscelis papua)
- Author
-
Rebecka L. Brasso, David Schutt, Alan M. Vajda, and Michael B. Wunder
- Subjects
Alternative methods ,animal structures ,food and beverages ,Zoology ,chemistry.chemical_element ,Biology ,biology.organism_classification ,Mercury (element) ,Specimen collection ,chemistry ,Feather ,visual_art ,embryonic structures ,visual_art.visual_art_medium ,Ecotoxicology ,General Agricultural and Biological Sciences ,Pygoscelis papua - Abstract
There is limited direct empirical evidence to evaluate the efficacy of using opportunistically found bird carcasses as proxies for estimating pollutant exposure in populations of live birds for avian ecotoxicology studies. In this study, we analyzed total mercury concentrations in feathers collected from live Gentoo Penguin (Pygoscelis papua) chicks and from Gentoo Penguin chick carcasses found at the same breeding colonies. Distributions of mercury concentrations for feathers from live-caught chicks and from found-dead chicks broadly overlap and, for our study, feathers from found-dead penguin chicks provide similar information about exposure to mercury as do feathers from live penguin chicks from the same locations. Our results suggest that, when mercury is estimated to be below adverse effect levels, the common practice of sampling from opportunistically found chick carcasses is a suitable and less-invasive alternative method of specimen collection in penguin colonies.
- Published
- 2021
- Full Text
- View/download PDF
20. A Computational Metabolic Model for Engineered Production of Resveratrol in Escherichia coli
- Author
-
Michael Cotner, Jixun Zhan, and Zhen Zhang
- Subjects
Alternative methods ,Biomedical Engineering ,General Medicine ,Resveratrol ,Stilbene synthase ,medicine.disease_cause ,Biochemistry, Genetics and Molecular Biology (miscellaneous) ,chemistry.chemical_compound ,Metabolic Model ,chemistry ,Plant production ,Yield (chemistry) ,medicine ,Production (economics) ,Biochemical engineering ,Escherichia coli - Abstract
Although engineered microbial production of natural compounds provides a promising alternative method to plant production and extraction, the process can be inefficient and ineffective in terms of time and cost. To render microbial systems profitable and viable, the process must be optimized to produce as much product as possible. To this end, this work illustrates the construction of a new probabilistic computational model to simulate the microbial production of a well-known cardioprotective molecule, resveratrol, and the implementation of the model to enhance the yield of the product in Escherichia coli. This model identified stilbene synthase as the limiting enzyme and informed the effects on changes in concentration and source of this enzyme. These parameters, when employed in a laboratory system, were able to improve the titer from 62.472 mg/L to 172.799 mg/L, demonstrating the model's ability to produce a useful simulation of a dynamic microbial resveratrol production system.
- Published
- 2021
- Full Text
- View/download PDF
21. Manufacture of non-thrombogenic polymer surfaces by gamma irradiation to induce simultaneous grafting and heparinization of thin PVC films
- Author
-
Selma Matheus Loureiro Guedes, Andreia de Araújo Morandim-Giannetti, and Luz Consuelo Gonzalez Alonso Panzarini
- Subjects
chemistry.chemical_classification ,Alternative methods ,Materials science ,Polymers and Plastics ,Platelet adhesion ,Bioengineering ,Context (language use) ,02 engineering and technology ,Polymer ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Grafting ,01 natural sciences ,0104 chemical sciences ,Biomaterials ,chemistry ,Chemical engineering ,Materials Chemistry ,Copolymer ,Blood compatibility ,0210 nano-technology ,Gamma irradiation - Abstract
Investigations regarding alternative methods for producing polymeric materials with hydrophilic properties have increased considerably. In this context, polymeric biomaterials with hemocompatible surface properties have been successfully obtained by grafting hydrophilic monomers onto commercial polymer films by simultaneous irradiation processes. In this study, simultaneous irradiation and grafting were used to produce a copolymer PVC-co-DMAEMA-co-heparin with hemocompatible surface properties. Characterization by FTIR of the graft copolymer indicates that the increase in monomer grafting levels inhibits the bonding sites to heparin. FTIR-PAS analyses of the graft copolymers showed that the highest graft levels were obtained for the irradiated samples containing 45% of monomer. Heparin, however, could only be detected in the irradiated samples containing 30% of DMAEMA. The analysis of the micrographs, on the other hand, showed that increasing the monomer concentration enhances surface roughness of the graft copolymers. Roughness however decreased with heparin addition. It was possible to verify that an excess of surface roughness of the graft copolymers inhibits anticoagulant properties of heparin, triggering thrombus formation. Platelet adhesion, on its turn, was not significantly affected by the presence of heparin when PVC-co-DMAEMA and PVC-co-DMAEMA-co-heparin, obtained from the systems containing 45% of monomer, are compared. The addition of heparin in the systems containing 30% of DMAEMA resulted in fewer thrombogenic surfaces.
- Published
- 2021
- Full Text
- View/download PDF
22. Triarylboranes in the Activation of Azo‐Containing Compounds
- Author
-
Mashael M. Alharbi, Rebecca L. Melen, Theodore A. Gazis, and Jamie L. Carden
- Subjects
Alternative methods ,chemistry.chemical_compound ,Main group element ,Transition metal ,chemistry ,Computational chemistry ,Molecule ,chemistry.chemical_element ,Diazo ,Nitrogen - Abstract
The field of nitrogen activation has traditionally been dominated by transition metals. However, concerns around the availability, environmental impact, and toxicity of some metals, in addition to renewed interest into the chemical reactivity of main group elements, have led chemists to investigate alternative methods of nitrogen activation. In particular, the use of boron-containing compounds has been prevalent in the activation of nitrogen-containing compounds. In this article, we aim to highlight how triarylboranes have been employed in the activation of azo-containing molecules, including diazo compounds, hydrazines, azides, and diazenes.
- Published
- 2021
- Full Text
- View/download PDF
23. Permeability of carbon refractory materials used in a blast furnace hearth
- Author
-
Janusz Tomala, Krzysztof Szyszkiewicz-Warzecha, Rafał Smulski, Stanisław Nagy, Robert Filipek, and Jakub Stec
- Subjects
010302 applied physics ,Alternative methods ,Blast furnace ,Materials science ,Annealing (metallurgy) ,Process Chemistry and Technology ,chemistry.chemical_element ,02 engineering and technology ,Microporous material ,021001 nanoscience & nanotechnology ,01 natural sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Permeability (earth sciences) ,Infiltration (hydrology) ,chemistry ,0103 physical sciences ,Materials Chemistry ,Ceramics and Composites ,Permeability measurements ,Composite material ,0210 nano-technology ,Carbon - Abstract
Permeability of experimental and standard micropore carbon materials, before and after the heat treatment at 1550 °C, was investigated using gas permeability measurements (GP) and mercury intrusion porosimetry (MIP). Permeability of both materials increased after the annealing. Experimental micropore carbon material was less permeable than standard one, both before and after the heat treatment. Measured gas permeabilities were compared with permeabilities determined based on MIP measurements using two different models: Hagen−Poiseuille and Carman−Kozeny equation. Using the inverse problem approach, for the first time Carman−Kozeny constant was determined for micropore carbon materials. Carman−Kozeny model gave more accurate results (i.e. close to gas permeability measurements) than Hagen−Poiseuille model. Performed investigations showed that mercury intrusion porosimetry might be alternative method to investigate infiltration resistance of low permeable materials.
- Published
- 2021
- Full Text
- View/download PDF
24. Development and Validation of a Spectrophotometric Method in the UV-Vis Region to Evaluate the Interactions of Estrogens with Humic Substances in an Aqueous Environment
- Author
-
Adriano Gonçalves Viana, Rômulo Domingues, Sheisa Fin Dantas Sierpinski, Laís M. França, Elizabeth Weinhardt de Oliveira Scheffer, Aline Jorge, Vitor da Silveira Freitas, and Giovana K. Wiecheteck
- Subjects
Alternative methods ,Aqueous solution ,Chromatography ,humic substances ,Materials Science (miscellaneous) ,General Chemical Engineering ,Science ,Estrone ,General Chemistry ,Sulfanilamide ,Bioavailability ,chemistry.chemical_compound ,Chemistry ,Ultraviolet visible spectroscopy ,endocrine disruptors ,chemistry ,Reagent ,medicine ,QD1-999 ,medicine.drug ,Hormone ,estrogens - Abstract
Natural and synthetic sex hormones are potent endocrine disruptors (EDs) that have been detected in aquatic environments on all continents. Studies show that humic substances (HS) are the main compounds capable of interacting with hormones, interfering in the bioavailability processes. In the present work, a methodology based on the colorimetric properties of the azo-compounds was developed and validated using diazotized sulfanilamide as a reagent to study the interactions with HS of estrogens: estrone (E1), 17β-estradiol (E2) and 17α-ethinylestradiol (EE2). As an alternative method to quantify hormones during interactions, ultraviolet-visible molecular absorption spectroscopy was employed. An analytical curve was constructed for concentrations ranging from 10.0 to 28.0 μg mL-1. The results were compatible with chromatography, also applied in this work. For the study of the interaction, samples of the hormone standard and HS solution were used under constant agitation. The reduction in the concentration of estrogens has been detected since the beginning of the process, with EE2 being the best result. In the aliquot removed from the system after 48 hours of agitation, 51.1% EE2 was removed in the presence of 10.0 μg mL-1 of the HS and 75.8% at 20 μg mL-1. Simulations can predict the behavior of hormones in natural aquatic environments rich in HS. DOI: http://dx.doi.org/10.17807/orbital.v13i2.1546
- Published
- 2021
25. Correction of the Deepened Labiomental Groove Using Silicone Implants in Advancement Genioplasty
- Author
-
Jungil Hwang and Bumjin Park
- Subjects
Male ,Chin ,medicine.medical_treatment ,Facial profile ,Silicones ,Esthetics, Dental ,Genioplasty ,Prosthesis ,chemistry.chemical_compound ,Silicone ,medicine ,Humans ,Groove (engineering) ,Dental Implants ,Alternative methods ,Orthodontics ,business.industry ,General Medicine ,Sulcus ,medicine.anatomical_structure ,Otorhinolaryngology ,chemistry ,Female ,Surgery ,business - Abstract
Advancement genioplasty is performed to aesthetically improve the lower third of the facial profile. Excessive chin advancement alone may lead to deepened labiomental sulcus and deformed aesthetic results. The purpose of this study was to assess the efficacy of silicone prosthesis placement as an alternative method for effacing an excessively deepened labiomental groove after advancement genioplasty. Three hundred and seventy-six patients underwent genioplasty between January 2014 and October 2017. Among these were 216 cases of advancement genioplasty, of which 79 (62 females and 17 males) underwent advancement procedures using silicone implants. Inserting the silicone implant at the sulcus easily removes the deepened groove. This procedure could be an easy and reliable method for attaining an aesthetically pleasing result in excessive advancement genioplasty.
- Published
- 2021
- Full Text
- View/download PDF
26. Comparison of Survey and Interview Methods for Collecting Recent Caffeine and Alcohol Use Data in College Students
- Author
-
Kathryn Polak, Enkelejda Ngelina, and Dace S. Svikis
- Subjects
Pharmacology ,Alternative methods ,Physiology ,Public Health, Environmental and Occupational Health ,Alcohol ,Biochemistry ,chemistry.chemical_compound ,chemistry ,Interview methods ,Benchmark data ,Caffeine ,Psychology ,Food Science ,Clinical psychology - Abstract
Background: The present study collected benchmark data on alternative methods for collecting quantity and frequency information about caffeine, alcohol, and caffeine and alcohol combined (CAFF+ALC)...
- Published
- 2021
- Full Text
- View/download PDF
27. Feasibility study on the use of near-infrared spectroscopy for rapid and nondestructive determination of gossypol content in intact cottonseeds
- Author
-
Bangsong Su, Tianlun Zhao, Cheng Li, Jinhong Chen, Cong Li, and Shuijin Zhu
- Subjects
Alternative methods ,Chromatography ,Chemistry ,010401 analytical chemistry ,Near-infrared spectroscopy ,Gossypol ,Plant culture ,04 agricultural and veterinary sciences ,040401 food science ,01 natural sciences ,Agricultural and Biological Sciences (miscellaneous) ,Biochemistry, Genetics and Molecular Biology (miscellaneous) ,High-performance liquid chromatography ,0104 chemical sciences ,Intact cottonseed ,SB1-1110 ,Cottonseed ,chemistry.chemical_compound ,0404 agricultural biotechnology ,Partial least squares regression ,Content (measure theory) ,Chemometrics ,Scatter correction - Abstract
Background Gossypol found in cottonseeds is toxic to human beings and monogastric animals and is a primary parameter for the integrated utilization of cottonseed products. It is usually determined by the techniques relied on complex pretreatment procedures and the samples after determination cannot be used in the breeding program, so it is of great importance to predict the gossypol content in cottonseeds rapidly and nondestructively to substitute the traditional analytical method. Results Gossypol content in cottonseeds was investigated by near-infrared spectroscopy (NIRS) and high-performance liquid chromatography (HPLC). Partial least squares regression, combined with spectral pretreatment methods including Savitzky-Golay smoothing, standard normal variate, multiplicative scatter correction, and first derivate were tested for optimizing the calibration models. NIRS technique was efficient in predicting gossypol content in intact cottonseeds, as revealed by the root-mean-square error of cross-validation (RMSECV), root-mean-square error of prediction (RMSEP), coefficient for determination of prediction (Rp2), and residual predictive deviation (RPD) values for all models, being 0.05∼0.07, 0.04∼0.06, 0.82∼0.92, and 2.3∼3.4, respectively. The optimized model pretreated by Savitzky-Golay smoothing + standard normal variate + first derivate resulted in a good determination of gossypol content in intact cottonseeds. Conclusions Near-infrared spectroscopy coupled with different spectral pretreatments and partial least squares (PLS) regression has exhibited the feasibility in predicting gossypol content in intact cottonseeds, rapidly and nondestructively. It could be used as an alternative method to substitute for traditional one to determine the gossypol content in intact cottonseeds.
- Published
- 2021
28. Moving toward generalizable NZ-1 labeling for 3D structure determination with optimized epitope-tag insertion
- Author
-
Kenji Iwasaki, Yoshinori Akiyama, Toru Ekimoto, Mika K. Kaneko, Terukazu Nogi, Yukinari Kato, Rika Oi, Takuya Miyake, Rie Aruga, Mitsunori Ikeguchi, Yohei Hizukuri, Mika Hirose, and Risako Tamura-Sakaguchi
- Subjects
Models, Molecular ,Protein Conformation ,medicine.drug_class ,Stereochemistry ,Complex formation ,Insertion site ,Crystallography, X-Ray ,Monoclonal antibody ,Antibody labeling ,Epitope ,Epitopes ,Immunoglobulin Fab Fragments ,antibody-assisted structural analysis ,Structural Biology ,protein crystallography ,medicine ,Alternative methods ,electron microscopy ,Chemistry ,Rigid structure ,Antibodies, Monoclonal ,Structural property ,Research Papers ,Microscopy, Electron ,Docking (molecular) ,Biophysics ,epitope insertion ,antibody labeling - Abstract
Antibody labeling has been conducted extensively for structure determination using both X-ray crystallography and electron microscopy (EM). However, establishing target-specific antibodies is a prerequisite for applying antibody-assisted structural analysis. To expand the applicability of this strategy, an alternative method has been developed to prepare an antibody complex by inserting an exogenous epitope into the target. It has already been demonstrated that the Fab of the NZ-1 monoclonal antibody can form a stable complex with a target containing a PA12 tag as an inserted epitope. Nevertheless, it was also found that complex formation through the inserted PA12 tag inevitably caused structural changes around the insertion site on the target. Here, an attempt was made to improve the tag-insertion method, and it was consequently discovered that an alternate tag (PA14) could replace various loops on the target without inducing large structural changes. Crystallographic analysis demonstrated that the inserted PA14 tag adopts a loop-like conformation with closed ends in the antigen-binding pocket of the NZ-1 Fab. Due to proximity of the termini in the bound conformation, the more optimal PA14 tag had only a minor impact on the target structure. In fact, the PA14 tag could also be inserted into a sterically hindered loop for labeling. Molecular-dynamics simulations also showed a rigid structure for the target regardless of PA14 insertion and complex formation with the NZ-1 Fab. Using this improved labeling technique, negative-stain EM was performed on a bacterial site-2 protease, which enabled an approximation of the domain arrangement based on the docking mode of the NZ-1 Fab., タンパク質の抗体ラベリング技術を改良し、構造解析をアシスト --電子顕微鏡やX線結晶解析による構造決定を加速化--. 京都大学プレスリリース. 2021-04-20.
- Published
- 2021
- Full Text
- View/download PDF
29. Highly Regioselective and Chemoselective [3 + 3] Annulation of Enaminones with ortho-Fluoronitrobenzenenes: Divergent Synthesis of Aposafranones and Their N-Oxides
- Author
-
Xue-Bing Chen, Fuchao Yu, Li Yang, Shun-Tao Huang, Qi Yang, and Jie Li
- Subjects
Alternative methods ,Annulation ,Scope (project management) ,010405 organic chemistry ,Chemistry ,Organic Chemistry ,Regioselectivity ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Combinatorial chemistry ,0104 chemical sciences ,chemistry.chemical_compound ,Nitro ,Organic synthesis ,Physical and Theoretical Chemistry ,Divergent synthesis - Abstract
A base-promoted unprecedented strategy for the regioselective and chemoselective divergent synthesis of highly functionalized aposafranones and their N-oxides has been developed from the [3 + 3] annulation of enaminones with o-fluoronitrobenzenenes. This novel synthetic strategy offers an alternative method for the construction of aposafranones and their N-oxides are meaningful in the fields of both biology and organic synthesis. The established protocol explores the annulation scope of enaminones, and it expands the application of nitro-based cyclization.
- Published
- 2021
- Full Text
- View/download PDF
30. Castration and alternatives in pig: advantages and disadvantages
- Author
-
Terézia Hegerová and Peter Juhás
- Subjects
Alternative methods ,Boar taint ,Animal Welfare (journal) ,business.industry ,Entire male ,Feed conversion ratio ,chemistry.chemical_compound ,Castration ,Animal science ,chemistry ,Medicine ,Animal Science and Zoology ,Christian ministry ,business ,Quality characteristics ,Agronomy and Crop Science ,Food Science - Abstract
Article Details: Received: 2020-07-07 | Accepted: 2020-11-05 | Available online: 2021-03-31 https://doi.org/10.15414/afz.2021.24.01.60-63 This article reviews the advantages and disadvantages of various alternatives to the surgical castration of piglets. Producers use castrations against boar taint which is present in the meat. Alternative methods could be immunocastration, production with entire male pigs or castration with anesthesia and/or analgesia. Production with entire male pigs means to feed pigs to lower carcasses, as the boar taint is very low at that time. But this method is not suitable for all especially If pigs need to be fattened up to 180-200 kg. Castration with anesthesia and analgesia reduces pain and is suitable for welfare but the cost of anesthesia and analgesia is high for some producers. The expense of immunocastration is also higher than for entire pigs but advantages of this method are higher meat percentage, better carcass quality, improved feed conversion ratio. Keywords: castration, immunocastration, boar taint, entire male pigs, castration with anesthesia or analgesia References Adam, J.L. (1977). Boar odour in entire males after slaughter. Agricultural Research in the New Zealand Ministry of Agriculture and Fisheries Annual Report of the Research Division, 1976–1977. Giffin, B. J., Allison, J. R., Martin, S., Ward, P. and Tschopp, A. (2008). Consumer acceptance of the use of vaccination to control boar taint. Proceedings 20th Int Pig Vet Soc Cong, Durban, South Africa. Aluwe, M., Langendries, K. C. M., Bekaert, K. M., Tuyttens, F. A. M., De Brabander, D. L., De Smet, S. and Millet, S. (2013). Effect of surgical castration, immunocastration and chicory-diet on the meat quality and palatability of boars. Meat Science, 94(3), 402–407. doi: https://doi.org/10.1016/j.meatsci.2013.02.015 Aluwe, M., Tuyttens, F. A. M. and Millet, S. (2015). Field experience with surgical castration with anaesthesia, analgesia, immunocastration and production of entire male pigs: performance, carcass traits and boar taint prevalence. Animal: an international journal of animal bioscience, 9(3), 500. doi: https://doi.org/10.1017/s1751731114002894 Aluwe, M., Vanhonacker, F., Millet, S. and Tuyttens, A. M. (2015). Influence of hands-on experience on pig farmers‘ attitude towards alternatives for surgical castration of male piglets. Research in Veterinary Science, 103, 80–86. doi: https://doi.org/10.1016/j.rvsc.2015.09.019 Batorek, N., Candek-Potokar, M., Bonneau, M. and Van Milgen, J. (2012). Meta-analysis of the effect of immunocastration on production performance, reproductive organs and boar taint compounds in pigs. Animal: an international journal of animal bioscience, 6(8), 1330. doi: https://doi.org/10.1017/s1751731112000146 Bee, G., Chevillon, P. and Bonneau, M. (2015). Entire male pig production in Europe. Animal Production Science, 55(12), 1347–1359. doi: https://doi.org/10.1071/an15279 Bohrer, B. M., Flowers, W. L., Kyle, J. M., Johnson, S. S., King, V. L., Spruill, J. L. and Boler, D. D. (2014). Effect of gonadotropin releasing factor suppression with an immunological on growth performance, estrus activity, carcass characteristics, and meat quality of market gilts. Journal of animal science, 92(10), 4719–4724. doi: https://doi.org/10.2527/jas.2014-7756 Brunius, C., Zamaratskaia, G., Andersson, K., Chen, G., Norrby, M., Madej, A. and Lundstrom, K. (2011). Early immunocastration of male pigs with Improvac® – Effect on boar taint, hormones and reproductive organs. Vaccine, 29(51), 9514–9520. doi: https://doi.org/10.1016/j.vaccine.2011.10.014 Candek-Potokar, M., Skrlep, M. and Zamaratskaia, G. (2017). Immunocastration as alternative to surgical castration in pigs. Theriogenology, 6, 109–126. doi: https://doi.org/10.5772/intechopen.68650 D’Souza, D. N. and Mullan, B. P. (2003). The effect of genotype and castration method on the eating quality characteristics of pork from male pigs. Animal Science, 77(1), 67–72. doi: https://doi.org/10.1017/s1357729800053650 Dostalova, A., Koucký, M. and Průsova, V. (2008). Výkrm kanecků v podminkach ekologickeho zemědělstvi. Mudrik, Z., Dvorak, J. Metodika zemědělskeho poradenskeho systemu. Dunshea, F. R., Colantoni, C., Howard, K., McCauley, I., Jackson, P., Long, K. A. and Hennessy, D. P. (2001). Vaccination of boars with a GnRH vaccine (Improvac) eliminates boar taint and increases growth performance. Journal of animal science, 79(10), 2524–2535. doi: https://doi.org/10.2527/2001.79102524x Fredriksen, B., Johnsen, A. M. S. and Skuterud, E. (2011). Consumer attitudes towards castration of piglets and alternatives to surgical castration. Research in veterinary science, 90(2), 352–357. doi: https://doi.org/10.1016/j.rvsc.2010.06.018 Hennessy, D. and Newbold, R. (2004). Consumer attitudes to a boar taint vaccine, Improvac (R)–A qualitative study. In Proceedings of the 18th IPVS congress, Hamburg, Germany, 612 p. Holinger, M., Fruh, B. and Hillmann, E. (2015). Group composition for fattening entire male pigs under enriched housing conditions – Influences on behaviour, injuries and boar taint compounds. Applied Animal Behaviour Science, 165, 47–56. doi: https://doi.org/10.1016/j.applanim.2015.01.016 Holinger, M., Fruh, B., Stoll, P., Graage, R., Wirth, S., Bruckmaier, R. and Hillmann, E. (2018). Chronic intermittent stress exposure and access to grass silage interact differently in their effect on behaviour, gastric health and stress physiology of entire or castrated male growing-finishing pigs. Physiology & behavior, 195, 58–68. doi: https://doi.org/10.1016/j.physbeh.2018.07.01 Huber-Eicher, B. and Spring, P. (2008). Attitudes of Swiss consumers towards meat from entire or immunocastrated boars: A representative survey. Research in veterinary science, 85(3), 625–627. doi: https://doi.org/10.1016/j.rvsc.2008.03.002 Viske, D., Lagerkvist, C. J. and Carlsson, F. (2006). Swedish consumer preferences for animal welfare and biotech: a choice experiment. AgBioForum 9(1), 51–58. Mellor, D. J. and Stafford, K. J. (2004). Animal welfare implications of neonatal mortality and morbidity in farm animals. The veterinary journal, 168(2), 118–133. doi: https://doi.org/10.1016/j.tvjl.2003.08.004 Mellor, D. J. and Gregory, N. G. (2003). Responsiveness, behavioural arousal and awareness in fetal and newborn lambs: experimental, practical and therapeutic implications. New Zealand veterinary journal, 51(1), 2–13. doi: https://doi.org/10.1080/00480169.2003.36323 Moberg, G. P. (2000). Biological response to stress: implications for animal welfare. The biology of animal stress: basic principles and implications for animal welfare, 1, 21. doi: https://doi.org/10.1079/9780851993591.0001 Needham, T. and Hoffman, L. C. (2015). Physical meat quality and chemical composition of the Longissimus thoracis of entire and immunocastrated pigs fed varying dietary protein levels with and without ractopamine hydrochloride. Meat science, 110, 101–108. doi: https://doi.org/10.1016/j.meatsci.2015.06.01 Nemethova, S. (2018). Vplyv trieslovin na kvalitu a nutricne zloženie masa kancekov. Nitra: SPU. Prunier, A., Bonneau, M., Von Borell, E. H., Cinotti, S., Gunn, M., Fredriksen, B. and Velarde, A. (2006). A review of the welfare consequences of surgical castration in piglets and the evaluation of non-surgical methods. Animal Welfare Journal, Universities Federation for Animal Welfare, 15, 277–289. Seiquer, I., Palma-Granados, P., Haro, A., Lara, L., Lachica, M., Fernandez-Figares, I. and Nieto, R. (2019). Meat quality traits in longissimus lumborum and gluteus medius muscles from immunocastrated and surgically castrated Iberian pigs. Meat science, 150, 77–84. doi: https://doi.org/10.1016/j.meatsci.2018.12.004 Telles, F. G., Luna, S. P. L., Teixeira, G. and Berto, D. A. (2016). Long-term weight gain and economic impact in pigs castrated under local anaesthesia. Veterinary and Animal Science, 1, 36–39. doi: https://doi.org/10.1016/j.vas.2016.11.003 Tuyttens, F. A., Vanhonacker, F., Langendries, K., Aluwe, M., Millet, S., Bekaert, K. and Verbeke, W. (2011). Effect of information provisioning on attitude toward surgical castration of male piglets and alternative strategies for avoiding boar taint. Research in Veterinary Science, 91(2), 327–332. doi: https://doi.org/10.1016/j.rvsc.2011.01.005 Tuyttens, F. A., Vanhonacker, F., Verhille, B., De Brabander, D. and Verbeke, W. (2012). Pig producer attitude towards surgical castration of piglets without anaesthesia versus alternative strategies. Research in Veterinary Science, 92(3), 524– 530. doi: https://doi.org/10.1016/j.rvsc.2011.02.017 Von Borell, E., Baumgartner, J., Giersing, M., Jaggin, N., Prunier, A., Tuyttens, F. A. M. and Edwards, S. A. (2009). Animal welfare implications of surgical castration and its alternatives in pigs. Animal, 3(11), 1488–1496. doi: https://doi.org/10.1017/s1751731109004728
- Published
- 2021
- Full Text
- View/download PDF
31. Biotransformation of sesquiterpenoids: a recent insight
- Author
-
Zaima Azira, Nurul Iman Aminudin, Deny Susanti, Zainal Abidin, and Munirah Ridzuan
- Subjects
Pharmacology ,Alternative methods ,Molecular Structure ,010405 organic chemistry ,Chemistry ,Organic Chemistry ,High selectivity ,Pharmaceutical Science ,General Medicine ,01 natural sciences ,0104 chemical sciences ,Analytical Chemistry ,010404 medicinal & biomolecular chemistry ,Complementary and alternative medicine ,Biotransformation ,Drug Discovery ,Molecular Medicine ,Organic chemistry ,Sesquiterpenes - Abstract
Sesquiterpenoids have been identified as natural compounds showing remarkable biological activities found in medicinal plants. There is great interest in developing methods to obtain sesquiterpenoids derivatives and biotransformation is one of the alternative methods for structural modification of complex sesquiterpenes structures. Biotransformation is a great drug design tool offering high selectivity and green method. The present review describes a comprehensive summary of biotransformation products of sesquiterpenoids and its structural modification utilizing a variety of biocatalysts including microorganisms, plant tissue culture and enzymes. This review covers recent literatures from 2007 until 2020 and highlights the experimental conditions for each biotransformation process.
- Published
- 2021
- Full Text
- View/download PDF
32. Synthesis of Fused Diaziridine Derivatives from Cyclic Secondary Amines by Utilizing N-Bromosulfonamides as an Aminating Reagent
- Author
-
Yuuki Kiyosu, Shino Tanaka, Kensuke Kiyokawa, Sota Okumura, and Satoshi Minakata
- Subjects
Alternative methods ,chemistry.chemical_classification ,Diaziridine ,Base (chemistry) ,010405 organic chemistry ,Chemistry ,Organic Chemistry ,010402 general chemistry ,01 natural sciences ,Combinatorial chemistry ,Catalysis ,0104 chemical sciences ,chemistry.chemical_compound ,Reagent - Abstract
The synthesis of a series of fused diaziridines, which are difficult to access by existing methods, was achieved by the reaction of cyclic secondary amines with p-toluenesulfonamide in the presence of N-bromosuccinimide (NBS) and a suitable base. This oxidation system enables the efficient in situ formation of the key intermediates, which are N-bromoamines (a precursor of cyclic imines) and N-bromosulfonamides. In addition, an alternative method using N-bromo-N-sodio-p-toluenesulfonamide (bromamine-T) in the presence of a catalytic amount of CF3CO2H for the synthesis of fused diaziridines is also reported.
- Published
- 2021
- Full Text
- View/download PDF
33. Evaluation of a commercial loop-mediated isothermal amplification assay, 3MTM Molecular Detection Assay 2 – Campylobacter, for the detection of Campylobacter from poultry matrices
- Author
-
R. Rajagopal, C. A. Barnes, J. M. David, and J. Goseland
- Subjects
Alternative methods ,Chromatography ,genetic structures ,Foodborne pathogen ,040301 veterinary sciences ,Chemistry ,Campylobacter ,technology, industry, and agriculture ,0402 animal and dairy science ,Loop-mediated isothermal amplification ,04 agricultural and veterinary sciences ,General Medicine ,medicine.disease_cause ,040201 dairy & animal science ,Rapid detection ,0403 veterinary science ,medicine ,Animal Science and Zoology ,Food Science - Abstract
1. The objective of this study was to evaluate performance of a commercial loop-mediated isothermal amplification (LAMP) method as an alternative method for the detection of Campylobacter spp. in p...
- Published
- 2021
- Full Text
- View/download PDF
34. Commercial raw materials from algaculture and natural stocks of Ulva spp
- Author
-
Ana Carolina Calheiros, Diana Negrão Cavalcanti, Lucas Pedra Maravilha Sales, Beatriz Castelar, Renata Perpetuo Reis, and Annibal Duarte Pereira Netto
- Subjects
0106 biological sciences ,chemistry.chemical_classification ,Alternative methods ,biology ,business.industry ,010604 marine biology & hydrobiology ,fungi ,food and beverages ,Biomass ,Lactuca ,Algaculture ,Plant Science ,Aquatic Science ,Raw material ,biology.organism_classification ,01 natural sciences ,Aquaculture ,chemistry ,Algae ,Agronomy ,Environmental science ,business ,Essential amino acid ,010606 plant biology & botany - Abstract
Ulva species have potential uses in several industrial sectors as they are rich in proteins, vitamins, fibers, and minerals. They also produce the essential amino acid tryptophan, which can act as an anxiolytic. With the increasing use of bioactive compounds obtained from algal species for commercial purposes, it will be necessary to evaluate the best methods for obtaining them, whether harvesting from natural beds or seaweed cultivation. Aquaculture has been indicated as an alternative method of acquiring algal biomass that avoids the harvesting and depredation of natural beds. To assess the feasibility of harvesting natural stocks of Ulva spp. (U. lactuca and U. flexuosa), algal biomass and relative species abundances were quantified at three sites in southeastern Brazil during 14 sampling periods. The results of those field biomass analyses allowed us to estimate their annual productions and compare them with projected productions of Ulva spp. under algaculture conditions. Tryptophan production by cultivated U. lactuca (as a high value-added product) was compared with the tryptophan concentrations of Ulva spp. from natural beds. No consistent patterns of total biomass production or relative abundances of the Ulva spp. were obtained during the sampling periods, making it impossible to accurately estimate sustainable biomass production for commercial uses. We diagnosed greater production sustainability in algaculture than in algal beds. The concentration of tryptophan produced by U. lactuca in algaculture was 60% higher than that from natural stocks. Tryptophan was quantified for the first time here in U. flexuosa.
- Published
- 2021
- Full Text
- View/download PDF
35. Radical Borylative Cyclization of Isocyanoarenes with N-Heterocyclic Carbene Borane: Synthesis of Borylated Aza-arenes
- Author
-
Jia-Qiang Wu, Zhi-Shu Huang, Ji-Lin Li, Yao Liu, Xu-Ge Liu, Qingjiang Li, and Honggen Wang
- Subjects
Reaction conditions ,Alternative methods ,010405 organic chemistry ,Organic Chemistry ,Borane ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Combinatorial chemistry ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Organic synthesis ,Physical and Theoretical Chemistry ,Carbene - Abstract
Borylated aza-arenes are of great importance in the area of organic synthesis. A radical borylative cyclization of isocyanoarenes with N-heterocyclic carbene borane (NHC-BH3) under metal-free conditions was developed. The reaction allows the efficient assembly of several types of borylated aza-arenes (phenanthridines, benzothiazoles, etc.), which are difficult to access using alternative methods. Mild reaction conditions, a good functional-group tolerance, and generally good efficiencies were observed. The utility of these products is demonstrated, and the mechanism is discussed.
- Published
- 2021
- Full Text
- View/download PDF
36. The clinical potential of prm-PASEF mass spectrometry
- Author
-
Antoine Lesur and Gunnar Dittmar
- Subjects
Proteomics ,0301 basic medicine ,Alternative methods ,030102 biochemistry & molecular biology ,Chemistry ,Proteins ,Computational biology ,Mass spectrometry ,Sensitivity and Specificity ,Biochemistry ,Mass Spectrometry ,03 medical and health sciences ,Targeted proteomics ,030104 developmental biology ,Humans ,Biomarker (medicine) ,Peptides ,Molecular Biology - Abstract
The continuous technical improvement in sensitivity and specificity placed mass spectrometry as an alternative method for analyzing clinical samples. In parallel to the rapid development of discovery proteomics, targeted acquisition has been implemented as a complementary option for measuring a small set of proteins with high sensitivity and robustness in a large sample cohort. The combination of trapped ion mobility with a rapid time-of-flight (TOF) mass spectrometer improves the sensitivity even further and triggers the development of prm-PASEF.This article discusses the development of prm-PASEF and its advantages over the existing targeted and discovery methods for analyzing clinical samples. We are also highlighting the different requirements for the use of prm-PASEF on clinical samples.prm-PASEF takes advantage of a dual ion-mobility trap enabling highly multiplexed targeted acquisition. It allows the implementation of a short chromatographic separation setup without sacrificing the number of targeted peptides. Analyzing clinical samples by prm-PASEF holds the promise to significantly improve throughput while maintaining sensitivity to detect the selected target proteins.
- Published
- 2021
- Full Text
- View/download PDF
37. Direct Poly(β-alanine) Synthesis via Polycondensation in Ionic Liquids
- Author
-
Martine Tessier, Shaodong Zhang, Alain Fradet, Herve Lefebvre, Brigitte Rousseau, and Leslie Dias Goncalves
- Subjects
Inorganic Chemistry ,Alternative methods ,chemistry.chemical_compound ,Condensation polymer ,Materials science ,Polymers and Plastics ,chemistry ,Organic Chemistry ,Polymer chemistry ,Ionic liquid ,Materials Chemistry ,Alanine synthesis ,Organic chemistry - Abstract
Poly(β-alanine) was successfully synthesized by an alternative method, which is the direct polyamidation of β-alanine in ionic liquids with triphenylphosphite as a condensing agent. It was found that 1,3-dimethylimidazolium dimethylphosphate was the most suitable reaction medium, in which a number-average degree of polymerization up to 49.5 was obtained. It was shown that the method is also applicable to the direct synthesis of polypeptides, for example, poly(l-valine) and poly(l-isoleucine).
- Published
- 2022
38. Accuracy of the dimethylmethylene blue spectrophotometric assay in measuring the amount of encapsulated pentosan polysulfate into nanoparticles
- Author
-
Hanin Abdel-Haq
- Subjects
Alternative methods ,Chromatography ,General Chemical Engineering ,education ,Nanoparticle ,Dimethylmethylene blue ,02 engineering and technology ,General Chemistry ,Pentosan polysulfate ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Biochemistry ,Industrial and Manufacturing Engineering ,0104 chemical sciences ,Chitosan ,chemistry.chemical_compound ,Capillary electrophoresis ,chemistry ,Materials Chemistry ,medicine ,0210 nano-technology ,health care economics and organizations ,medicine.drug - Abstract
Dimethylmethylene blue (DMMB) spectrophotometric assay was used to estimate the amount of pentosan polysulfate (PPS), a heparin-like glycosaminoglycan (GAG), encapsulated in chitosan-based nanoparticles (NPs) as an alternative method for capillary zone electrophoresis (CZE) that has been shown to lack sensitivity. The analytical performance of the DMMB method was evaluated, which revealed the response of PPS is linear in the investigated concentration range (R2 = 0.9996). The detection and quantification limits were
- Published
- 2021
- Full Text
- View/download PDF
39. High pressure switchable water: an alternative method for separating organic products from water
- Author
-
Huilin Yang, Philip G. Jessop, and Igor Cunha
- Subjects
Alternative methods ,Organic product ,business.industry ,Fossil fuel ,Biomass ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Pulp and paper industry ,7. Clean energy ,Pollution ,6. Clean water ,chemistry.chemical_compound ,020401 chemical engineering ,chemistry ,13. Climate action ,High pressure ,Acetone ,Environmental Chemistry ,Environmental science ,0204 chemical engineering ,0210 nano-technology ,business ,Reverse osmosis ,Bar (unit) - Abstract
Biomass conversion to organic products is expected to be a core technology for the future sustainable society. Still, published studies show that the energy cost and environmental impact of making organic products from biomass are often worse than making those products from fossil fuels. The problematic step in biomass conversion is the removal of water. Unless the environmental and energetic costs of separating water from organic products can be lowered, bio-derived products will struggle to be greener and cheaper than fossil-derived products. We propose a new method for separating organic products from water: high pressure switchable water (HPSW). HPSW is a process that combines two known phenomena: CO2 expansion of liquids (CXL) and CO2-switchable water (SW). HPSW takes advantage of the benefits of changing the polarity of organic liquids at high CO2 pressures and the repulsive amine-solute interactions that occur after SW amines are exposed to CO2, both contributing to the removal of the organics from water. Each process alone can trigger the separation of some organics from water, but individually they are not efficient for removing hydrophilic organic solutes. We hypothesised that CXL and SW, if performed simultaneously, would act synergistically and promote more efficient and cleaner separations. For test mixtures of acetone and water, we demonstrated that several amine ionogens could promote phase separation of the acetone from water at lower pressures than CXL alone. 2,6,10-Trimethyl-2,6,10-triazaundecane (TMTAD) was one of the best amines tested, decreasing the separation pressure to 3 bar of CO2 compared to 30 bar without an ionogen. In addition, 93% of the initial TMTAD added to the mixture was recovered using reverse osmosis (RO). If HPSW can reduce the energy consumption of separations, the current separation issues faced by the biomass conversion sector might be overcome.
- Published
- 2021
- Full Text
- View/download PDF
40. A Review: Alternative Methods of Preparing 1, 4- Dihydropyridine Derivatives by Hantzsch Reaction
- Author
-
Sandhya Patil and Leena Sarkar
- Subjects
Alternative methods ,Chemistry ,1 4 dihydropyridine derivatives ,Combinatorial chemistry - Published
- 2021
- Full Text
- View/download PDF
41. Determination of Mogroside V in Luohanguo Extract for Daily Quality Control Operation Using Relative Molar Sensitivity to Single-Reference Caffeine
- Author
-
Hiroshi Matsufuji, Miho Kuroe, Yuzo Nishizaki, Masahiko Numata, Naoko Masumoto, Naoki Sugimoto, Kyoko Ishizuki, Kyoko Sato, Taichi Yamazaki, and Takashi Ohtsuki
- Subjects
Quality Control ,Alternative methods ,Magnetic Resonance Spectroscopy ,Chromatography ,Plant Extracts ,Significant difference ,General Chemistry ,General Medicine ,Mogroside V ,High-performance liquid chromatography ,Triterpenes ,Quantitative determination ,Cucurbitaceae ,chemistry.chemical_compound ,Certified reference materials ,Japan ,chemistry ,Mogroside ,Caffeine ,Drug Discovery ,Food Additives ,Sensitivity (electronics) ,Chromatography, High Pressure Liquid - Abstract
Mogroside V is one of the characteristic and effective components of luohanguo extract, a food additive used as a sweetener in Japan as per Japan's Standards and Specifications for Food Additives (JSFA; 9th ed.). JSFA stipulates that the quantitative determination for mogroside V content in luohanguo extract applies HPLC using analytical standard mogroside V. However, no mogroside V reagents with proven purities are commercially available. Therefore the current JSFA determination method is not particularly suited for daily quality control operations involving luohanguo extract. In this study, we applied an alternative quantitative method using a single reference with relative molar sensitivity (RMS). It was possible to calculate the accurate RMS by an offline combination of 1H-quantitative NMR spectroscopy (1H-qNMR) and an HPLC/variable-wavelength detector (VWD). Using the RMS of mogroside V to a commercial certified reference material grade caffeine, the mogroside V contents in luohanguo extracts could be determined using HPLC/VWD without analytical standard mogroside V. There was no significant difference between the mogroside V contents in luohanguo extracts determined using the method employing single-reference caffeine with the RMS and using the JSFA method. The absolute calibration curve for the latter was prepared using an analytical standard mogroside V whose purity was determined by 1H-qNMR. These results demonstrate that our proposed method using a single reference with RMS is suitable for quantitative determination of mogroside V in luohanguo extract and can be used as an alternative method to the current assay method in JSFA.
- Published
- 2021
- Full Text
- View/download PDF
42. Synthesis of (η6-arene)tricarbonylchromium derivatives of 1,4-dihydro-3,1-benzoxazines
- Author
-
Yu. A. Zaytseva, N. Yu. Grishina, Nikolay V. Somov, E. V. Sazonova, N. A. Aksenova, V. I. Faerman, A. A. Timofeeva, and A. N. Artemov
- Subjects
Alternative methods ,1h nmr spectroscopy ,010405 organic chemistry ,chemistry.chemical_element ,Alcohol ,General Chemistry ,010402 general chemistry ,Mass spectrometry ,01 natural sciences ,Medicinal chemistry ,High-performance liquid chromatography ,0104 chemical sciences ,chemistry.chemical_compound ,Chromium ,chemistry - Abstract
A series of (η6-arene)tricarbonylchromium derivatives of 1,4-dihydro-3,1-benzoxazines was synthesized and characterized. The compounds were obtained by two alternative methods, namely, by the reaction of triammine(tricarbonyl)chromium with 1,4-dihydro-3,1-benzoxazines (method A) and by the condensation of (η6-2-aminobenzyl alcohol)tricarbonylchromium with various aldehydes and ketones (method B). The composition and structure of obtained compounds were established by different physicochemical methods of analysis, such as HPLC, UV, IR, 1H NMR spectroscopy, mass spectrometry, and X-ray diffraction.
- Published
- 2021
- Full Text
- View/download PDF
43. Special Topic Commentary
- Author
-
Jacek R. Wiśniewski
- Subjects
Proteomics ,chemistry.chemical_classification ,Alternative methods ,Absolute quantification ,Quantitative proteomics ,Proteins ,Pharmaceutical Science ,Peptide ,02 engineering and technology ,Computational biology ,Reference Standards ,021001 nanoscience & nanotechnology ,Mass spectrometry ,030226 pharmacology & pharmacy ,Mass Spectrometry ,03 medical and health sciences ,0302 clinical medicine ,chemistry ,Sample Type ,Peptides ,0210 nano-technology - Abstract
Determination of abundances of proteins involved in uptake, distribution, metabolism and excretion of xenobiotics is a prerequisite to understand and predict elimination mechanisms in tissue. Mass spectrometry promises simple and accurate measurements of individual proteins in complex mixtures using isotopically labeled peptide standards. However, comparisons of measurements performed in different laboratories have shown considerable discrepancies in the data generated. Even when very similar approaches are compared, the results differ significantly. An alternative method of measuring protein titers is global proteomics. Depending on sample type, this allows quantification of hundreds to thousands of proteins in a single analysis. It enables system-wide insights by providing protein copy numbers and cell sizes. Regardless of differences, the workflows of both the labeled standard-based and the proteomic approach share several steps. Each can be critical. Selection of optimal techniques is the prerequisite for accurate and reproducible protein quantification. (C) 2020 American Pharmacists Association (R). Published by Elsevier Inc. All rights reserved.
- Published
- 2021
- Full Text
- View/download PDF
44. Sulfonyl radical-induced regioselective cyclization of 3-aza-1,5-enynes with sulfonyl chlorides to produce 1,2-dihydropyridines by copper catalysis
- Author
-
Ran Ding, Hai-Yu Tian, Jian-Ming Fu, Nian-Shou Chen, Yu Guo, Pei-Long Wang, and Lei Liu
- Subjects
Alternative methods ,Sulfonyl ,chemistry.chemical_classification ,010405 organic chemistry ,Chemistry ,Regioselectivity ,chemistry.chemical_element ,General Chemistry ,010402 general chemistry ,01 natural sciences ,Combinatorial chemistry ,Copper ,Catalysis ,0104 chemical sciences ,Present method ,Materials Chemistry - Abstract
A Cu-catalyzed regioselective cyclization of 3-aza-1,5-enynes with sulfonyl chlorides for the synthesis of 1,2-dihydropyridines is described. This present method provided a new pathway for the construction of 1,2-dihydropyridines from 3-aza-1,5-enynes in reasonable yields and an alternative method for the synthesis of 3-functionalized multi-substituted pyridines.
- Published
- 2021
- Full Text
- View/download PDF
45. Chemosensors based on N-heterocyclic dyes: advances in sensing highly toxic ions such as CN− and Hg2+
- Author
-
María-Camila Ríos, Christian-Camilo Sánchez, Nestor-Fabian Bravo, and Jaime Portilla
- Subjects
Alternative methods ,Human health ,Biocompatibility ,Aqueous medium ,Chemistry ,General Chemical Engineering ,Monitoring system ,General Chemistry ,Combinatorial chemistry ,Fluorescence ,Ion - Abstract
CN− and Hg2+ ions are harmful to both the environment and human health, even at trace levels. Thus, alternative methods for their detection and quantification are highly desirable given that the traditional monitoring systems are expensive and require qualified personnel. Optical chemosensors (probes) have revolutionized the sensing of different species due to their high specificity and sensitivity, corresponding with their modular design. They have also been used in aqueous media and different pH ranges, facilitating their applications in various samples. The design of molecular probes is based on organic dyes, where the key species are N-heterocyclic compounds (NHCs) due to their proven photophysical properties, biocompatibility, and synthetic versatility, which favor diverse applications. Accordingly, this review aims to provide an overview of the reports from 2016 to 2021, in which fluorescent probes based on five- and six-membered N-heterocycles are used for the detection of CN− and Hg2+ ions.
- Published
- 2021
- Full Text
- View/download PDF
46. Metal-catalysed C–Het (F, O, S, N) and C–C bond arylation
- Author
-
Zhuangzhi Shi, Lutz Ackermann, Binlin Zhao, and Torben Rogge
- Subjects
Alternative methods ,010405 organic chemistry ,Negishi coupling ,Chemistry ,Bond ,Sonogashira coupling ,General Chemistry ,010402 general chemistry ,01 natural sciences ,Combinatorial chemistry ,0104 chemical sciences ,Metal ,Chemical bond ,visual_art ,visual_art.visual_art_medium ,Molecule - Abstract
The formation of C-aryl bonds has been the focus of intensive research over the last decades for the construction of complex molecules from simple, readily available feedstocks. Traditionally, these strategies involve the coupling of organohalides (I, Br, Cl) with organometallic reagents (Mg, Zn, B, Si, Sn,…) such as Kumada-Corriu, Negishi, Suzuki-Miyaura, Hiyama and Sonogashira cross-couplings. More recently, alternative methods have provided access to these products by reactions with less reactive C-Het (F, O, S, N) and C-C bonds. Compared to traditional methods, the direct cleavage and arylation of these chemical bonds, the essential link in accessible feedstocks, has become increasingly important from the viewpoint of step-economy and functional-group compatibility. This comprehensive review aims to outline the development and advances of this topic, which was organized into (1) C-F bond arylation, (2) C-O bond arylation, (3) C-S bond arylation, (4) C-N bond arylation, and (5) C-C bond arylation. Substantial attention has been paid to the strategies and mechanistic investigations. We hope that this review can trigger chemists to discover more efficient methodologies to access arylation products by cleavage of these C-Het and C-C bonds.
- Published
- 2021
- Full Text
- View/download PDF
47. The application of aptamer Apt-236 targeting PvpA protein in the detection of antibodies against Mycoplasma gallisepticum
- Author
-
Qiao Xilan, Yunke Zhang, Feng Wang, Ping Fu, Xinbo Yan, Wenyan Zhou, Yuewei Zhang, and Wenxue Wu
- Subjects
Alternative methods ,Mycoplasma gallisepticum ,0303 health sciences ,biology ,Chemistry ,General Chemical Engineering ,Aptamer ,010401 analytical chemistry ,General Engineering ,biology.organism_classification ,01 natural sciences ,Virology ,0104 chemical sciences ,Analytical Chemistry ,03 medical and health sciences ,Elisa kit ,chemistry.chemical_compound ,Antibody response ,biology.protein ,Antibody ,DNA ,030304 developmental biology - Abstract
Mycoplasma gallisepticum (M. gallisepticum) is the primary agent of chronic respiratory disease causing important economic losses in the poultry industry. Compared to antibodies, aptamers used to diagnose M. gallisepticum have many advantages, such as being chemically, animal-free produced and easily modifiable without affecting their affinity. Herein, a single-stranded DNA (ssDNA) aptamer Apt-236 which can specifically bind to PvpA protein of M. gallisepticum with a Kd of 1.30 ± 0.18 nM was selected successfully. An indirect blocking ELAA (ib-ELAA) for M. gallisepticum antibodies detection was also developed using Apt-236, in which M. gallisepticum antibodies would block the binding-position of aptamers. Therefor positive sera would prevent color development whereas negative sera will allow a strong color reaction. The ib-ELAA was consistent with other three widely used assays in terms of the growth and decline of the antibody response to M. gallisepticum, and showed substantial agreement with the results obtained using a commercial ELISA kit in clinical chicken sera samples. Therefore, the ib-ELAA developed in this study was a new format for aptamer application and would be an alternative method for the surveillance of M. gallisepticum.
- Published
- 2021
- Full Text
- View/download PDF
48. Overcoming lithium analysis difficulties with a simple colorimetric/spectrophotometric method
- Author
-
Alceu T. Silveira, Henrique E. Toma, and Lucas Fonseca Quartarolli
- Subjects
Ions ,Alternative methods ,Materials science ,Chromatography ,Chromogenic ,Iron ,General Chemical Engineering ,Routine work ,General Engineering ,chemistry.chemical_element ,FLUORESCÊNCIA ,Lithium ,Fluorescence ,Analytical Chemistry ,law.invention ,chemistry ,Spectrophotometry ,law ,Smartphone app ,Colorimetry ,Atomic absorption spectroscopy ,Filtration - Abstract
The analytical determination of lithium ions is usually performed by atomic absorption and X-ray fluorescence methods. Chemical analysis based on polyfluoroporphyrin chromogenic methods is also being employed, especially for biological samples. However, all existing methods are expensive and not suitable for routine work or field assays. The alternative method proposed here is based on the formation of a LiKFe(IO6) compound which is converted into a tris(1,10-phenanthroline)iron(II) complex and monitored by spectrophotometric or colorimetric methods, the latter using a smartphone app. Under similar conditions, these two methods proved superior to the X-ray fluorescence method. A one pot analysis of lithium ions is also described, using an Eppendorf microtube previously modified for performing reaction, filtration and detection. This method is simple and very convenient for didactic and field assays.
- Published
- 2021
- Full Text
- View/download PDF
49. Recent advances in the transition-metal-free synthesis of quinoxalines
- Author
-
L. Raju Chowhan and Biplob Borah
- Subjects
Synthetic drugs ,Alternative methods ,chemistry.chemical_compound ,Engineering ,chemistry ,business.industry ,General Chemical Engineering ,Optoelectronic materials ,Organic synthesis ,General Chemistry ,Biochemical engineering ,business - Abstract
Quinoxalines, also known as benzo[a]pyrazines, constitute an important class of nitrogen-containing heterocyclic compounds as a result of their widespread prevalence in natural products, biologically active synthetic drug candidates, and optoelectronic materials. Owing to their importance and chemists' ever-increasing imagination of new transformations of these products, tremendous efforts have been dedicated to finding more efficient approaches toward the synthesis of quinoxaline rings. The last decades have witnessed a marvellous outburst in modifying organic synthetic methods to create them sustainable for the betterment of our environment. The exploitation of transition-metal-free catalysis in organic synthesis leads to a new frontier to access biologically active heterocycles and provides an alternative method from the perspective of green and sustainable chemistry. Despite notable developments achieved in transition-metal catalyzed synthesis, the high cost involved in the preparation of the catalyst, toxicity, and difficulty in removing it from the final products constitute disadvantageous effects on the atom economy and eco-friendly nature of the transformation. In this review article, we have summarized the recent progress achieved in the synthesis of quinoxalines under transition-metal-free conditions and cover the reports from 2015 to date. This aspect is presented alongside the mechanistic rationalization and limitations of the reaction methodologies. The scopes of future developments are also highlighted.
- Published
- 2021
- Full Text
- View/download PDF
50. Sunlight-mediated [3 + 2] cycloaddition of azobenzenes with arynes: an approach toward the carbazole skeleton
- Author
-
Hongji Li, Pinhua Li, Lei Wang, Wenjie Zhang, and Jiahui Bu
- Subjects
Alternative methods ,Trimethylsilyl ,010405 organic chemistry ,Carbazole ,Organic Chemistry ,010402 general chemistry ,Photochemistry ,01 natural sciences ,Aryne ,Cycloaddition ,0104 chemical sciences ,chemistry.chemical_compound ,Transition metal ,chemistry - Abstract
A sunlight-mediated [3 + 2] cycloaddition of azobenzenes with arynes that are in situ generated from ortho-(trimethylsilyl)phenyl triflates has been developed in the absence of transition metals or photocatalysts. This strategy provides an alternative method for the efficient construction of the carbazole backbone.
- Published
- 2021
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.