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The escalating demand for energy storage underscores the significance of supercapacitors as devices with extended lifespans, high energy densities, and rapid charge-discharge capabilities. Ceria (CeO2), known for its exceptional properties and dual oxidation states, emerges as a potent material for supercapacitor electrodes. This study enhances its capacitance by integrating it with Metal-Organic Frameworks (MOFs), carbon-rich compounds noted for their good conductivity. In our research, hollow ceria (h-ceria) is synthesized via hydrothermal methods and amalgamated with Ce-MOF, employing 2,6-dinaphthalene dicarboxylic acid as a ligand, to fabricate Ce-MOF@h-CeO2 composites. The structural and morphological characteristics of the composite are methodically examined using X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), and Fourier-Transform Infrared (FT-IR) spectroscopy. The band gap of the materials is ascertained through UV-Diffuse Reflectance Spectroscopy (UV-DRS). Electrochemical behavior and redox properties of the Ce-MOF composites are explored using Cyclic Voltammetry (CV), Galvanostatic Charge and Discharge (GCD), and Electrochemical Impedance Spectroscopy (EIS), providing insights into the material's stability. Electrochemical characterization of the composite reveals maximum specific capacitance, energy density and power density are 2643.78 F g-1 at a scan rate of 10 mV s-1, 249.22 W h kg-1, and 7.9 kW kg-1, respectively. Additionally, the specific capacitance of Ce-MOF synthesized with a 2,6-dinaphthalene dicarboxylic acid (NDC) ligand reaches 995.59 F g-1, surpassing that of Ce-MOF synthesized using a 1,3,5-tricarboxylic acid (H3BTC) ligand. These findings highlight the promising economic potential of high-performance, environmentally sustainable, and cost-effective energy storage devices. The innovative Ce-MOF@h-CeO2 composite materials at the core of this research pave the way for advancing the field of energy storage solutions.
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In recent years, heat stress has affected potato production more frequently, resulting in lower marketable yields and reduced tuber quality. In order to develop heat-tolerant potatoes, it is necessary to select under heat-stress conditions and consider traits affected by heat stress. The Texas A&M Potato Breeding Program has selected potatoes under high-temperature stress for several decades. Ten potato cultivars, representing heat tolerant and sensitive clones based on past performance in Texas, were included in field trials for three years at the two main locations used by the Texas Breeding Program (Dalhart and Springlake, TX) to assess if the Texas field locations are suitable for heat tolerance screening. Both locations were confirmed as appropriate for heat stress screening. However, Springlake was a more stressful location since it had significantly lower yields of marketable tubers and increased percentages of tuber defects. Planting time did not have a significant effect at the most stressful location. The same ten potato clones were included in greenhouse experiments with contrasting temperatures (normal versus heat stress). There was confirmation that heat stress conditions resulted in significantly lower marketable yields, specific gravity, dormancy, and significantly higher percentages of tuber defects; however, significant differences existed between potato clones. Under heat stress conditions, Russet Burbank had a high percent of tubers with external defects, whereas Atlantic showed the highest percentage of internal defects (mainly internal heat necrosis). Vanguard Russet produced the highest marketable yield while maintaining a low percentage of external and internal defects. Russet Burbank and Atlantic were heat-sensitive controls for external and internal tuber defects, respectively. In contrast, Vanguard Russet can be used as a reliable heat-tolerant control. Including appropriate controls in heat stress studies will help identify clones with heat tolerance.
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The surge in interest surrounding energy storage solutions, driven by the demand for electric vehicles and the global energy crisis, has spotlighted the effectiveness of carbon-based supercapacitors in meeting high-power requirements. Concurrently, metal-organic frameworks (MOFs) have gained attention as a template for their integration with graphene oxide (GO) in composite materials which have emerged as a promising avenue for developing high-power supercapacitors, elevating smart supercapacitor efficiency, cyclic stability, and durability, providing crucial insights for overcoming contemporary energy storage obstacles. The identified combination leverages the strengths of both materials, showcasing significant potential for advancing energy storage technologies in a sustainable and efficient manner. In this research, an in-depth review has been presented, in which properties, rationale and integration of MOF/GO composites have been critically examined. Various fabrication techniques have been thoroughly analyzed, emphasizing the specific attributes of MOFs, such as high surface area and modifiable porosity, in tandem with the conductive and stabilizing features of graphene oxide. Electrochemical characterizations and physicochemical mechanisms underlying MOF/GO composites have been examined, emphasizing their synergistic interaction, leading to superior electrical conductivity, mechanical robustness, and energy storage capacity. The article concludes by identifying future research directions, emphasizing sustainable production, material optimization, and integration strategies to address the persistent challenges in the field of energy storage. In essence, this research article aims to offer a concise and insightful resource for researchers engaged in overcoming the pressing energy storage issues of our time through the exploration of MOF/GO composites in smart supercapacitors.
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Hydroxyapatite (HAp) with the chemical formula Ca10(PO4)6(OH)2 is an inorganic material that exhibits morphology and composition similar to those of human bone tissues, making it highly desirable for bone regeneration applications. As one of the most biocompatible materials currently in use, HAp has undergone numerous attempts to enhance its mechanical strength. This research focuses on investigating the influence of magnesium (Mg) incorporation on the structural and mechanical properties of synthesized magnesium-doped hydroxyapatite (MgHAp) samples. Apart from its biocompatibility, Mg possesses a density and elasticity comparable to those of human bone. Therefore, incorporating Mg into HAp can be pivotal for improving bone formation. Previous studies have not extensively explored the structural changes induced by Mg substitution in HAp, which motivated us to revisit this issue. Hydrothermal synthesis technique was used to synthesize MgHAp samples with varying molar concentrations (x = 0, 0.5, 1.0, and 1.5). Theoretical simulation of HAp and MgHAp for obtaining 3D structures has been done, and theoretical X-ray diffraction (XRD) data have been compared with the experimental XRD data. Rietveld analysis revealed the alteration and deviation of lattice parameters with an increase in the Mg content, which ultimately affect the structure as well the mechanical properties of prepared samples. The findings revealed an increase in compressive stress and fracture toughness as the Mg concentration in the composition increased. Furthermore, using a finite-element analysis technique and modeling of the mechanical testing data, the von Mises stress distribution and Young's modulus values were calculated, demonstrating the similarity of the prepared samples to human cortical bone. Biocompatibility assessments using NIH-3T3 fibroblast cells confirmed the biocompatible and bioactive nature of the synthesized samples. MgHAp exhibits great potential for biomedical applications in the dental, orthopedic, and tissue engineering research fields.
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Durapatita , Magnésio , Humanos , Durapatita/química , Magnésio/química , Materiais Biocompatíveis/química , Osso e Ossos , Próteses e ImplantesRESUMO
Heat stress during the potato growing season reduces tuber marketable yield and quality. Tuber quality deterioration includes external (heat sprouts, chained tubers, knobs) and internal (vascular discoloration, hollow heart, internal heat necrosis) tuber defects, as well as a reduction in their specific gravity and increases in reducing sugars that result in suboptimal (darker) processed products (french fries and chips). Successfully cultivating potatoes under heat-stress conditions requires planting heat-tolerant varieties that can produce high yields of marketable tubers, few external and internal tuber defects, high specific gravity, and low reducing sugars (in the case of processing potatoes). Heat tolerance is a complex trait, and understanding its genetic basis will aid in developing heat-tolerant potato varieties. A panel of 217 diverse potato clones was evaluated for yield and quality attributes in Dalhart (2019 and 2020) and Springlake (2020 and 2021), Texas, and genotyped with the Infinium 22 K V3 Potato Array. A genome-wide association study was performed to identify genomic regions associated with heat-tolerance traits using the GWASpoly package. Quantitative trait loci were identified on chromosomes 1, 3, 4, 6, 8, and 11 for external defects and on chromosomes 1, 2, 3, 10, and 11 for internal defects. Yield-related quantitative trait loci were detected on chromosomes 1, 6, and 10 pertaining to the average tuber weight and tuber number per plant. Genomic-estimated breeding values were calculated using the StageWise package. Clones with low genomic-estimated breeding values for tuber defects were identified as donors of good traits to improve heat tolerance. The identified genomic regions associated with heat-tolerance attributes and the genomic-estimated breeding values will be helpful to develop new potato cultivars with enhanced heat tolerance in potatoes.
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Starch-based biofilms with embedded nanoparticles (NPs) are used to wrap food in biodegradable packaging system that has high antibacterial action against a variety of microorganisms. In this study, ZnO NPs were synthesised using both a green synthesis approach utilising Azadirachta indica (Neem) and a chemical synthesis approach using the sol-gel technique. The structural and morphological properties of all synthesized NPs were characterized through XRD, UV-VIS, UV-DRS, FTIR, and FESEM analysis. Further, these NPs were employed in the development of starch-based biodegradable films. A meticulous comparative analysis was performed to evaluate the functional properties of the nanocomposites, encompassing crucial parameters such as film thickness, moisture content, swelling index, opacity, solubility, water vapor permeability, and tensile strength. In comparison to films embedded with chemically synthesised NPs (F1), nanocomposite with green synthesised NPs (F2) showed 15.27% greater inhibition against Escherichia coli growth and 22.05% stronger inhibition against Staphylococcus aureus bacterial strains. Based on the biodegradability analysis, the nanocomposite film-F2 showed a 53.33% faster degradation rate compared to the film-F1. The developed films were utilized to assess the quality of both wrapped and unwrapped grapes, leading to the generalization of the research for the development of starch-based antibacterial and environmentally friendly food packaging material. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-023-05834-9.
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This study explores influence of charge transfer and X-ray absorption characteristics in aluminum (Al) and copper (Cu) co-doped zinc oxide (ZnO) nanostructures for perovskite solar cell electrodes. Sol-gel technique was employed to synthesize the nanostructures, and their optical and morphological properties were investigated. X-ray diffraction (XRD) analysis confirmed high crystallinity and also single-phase composition of all the samples, particularly up to 5% Al co-doping. Field emission scanning electron microscopy (FESEM) exhibited the formation of pseudo-hexagonal wurtzite nanostructure and the transition to nanorods at 5% Al co-doping. Diffuse reflectance spectroscopy indicated a reduction in the optical band gap of co-doped zinc oxide from 3.11 to 2.9 eV with increasing Al doping. Photoluminescence spectra (PL) exhibited a decrease in peak intensity, suggesting enhanced conductivity in ZnO, also confirmed from I-V measurements. Near-edge X-ray absorption fine structure (NEXAFS) analysis depicts that charge transfer from Al to oxygen (O) species enhanced the photosensing properties of the nanostructure, which was supported by FESEM micrographs and PL spectra. Furthermore, the study discovered that 5% Al co-doping significantly reduced the density of emission defects (deep-level) in Cu-ZnO nanostructure. These findings highlight the potential of Cu and Al co-doped ZnO materials for perovskite solar cell electrodes, as their improved optical and morphological properties resulting from charge transfer could enhance device performance. The investigation of charge transfer and X-ray absorption characteristics provides valuable insights into the underlying mechanisms and behaviors of the co-doped ZnO nanostructures. However, further research is required to delve into the intricate hybridization resulting from charge transfer and explore the broader impact of co-doping on other properties of the nanostructures, enabling a comprehensive understanding of their potential applications in perovskite solar cells.
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Highly nanocrystalline carbonated hydroxyapatite (CHAp) is synthesized by hydrothermal technique with four different stoichiometric compositions for microstructural and mechanical analysis. HAp is one of the most biocompatible material and addition of carbonate ions lead to increase in fracture toughness highly required in biomedical applications. The structural properties and its purity as single phase is confirmed by X-ray diffraction. Lattice imperfections and structural defects is investigated using XRD pattern model simulation, i.e. Rietveld's analysis. The substitution of CO32- in HAp structure leads to a decrease in crystallinity which ultimately lessens crystallite size of sample as verified by XRD analysis. FE-SEM micrographs confirms the formation of nanorods with cuboidal morphology and porous structure of HAp and CHAp samples. The particle size distribution histogram validates the constant decrease in size due to carbonate addition. The mechanical testing of prepared samples revealed the increase in mechanical strength from 6.12 MPa to 11.52 MPa due to the addition of carbonate content, which leads to a rise in fracture toughness, a significant property of an implant material from 2.93 kN to 4.22 kN. The cumulative effect of CO32- substitution on HAp structure and mechanical properties has been generalized for the application as biomedical implant material or biomedical smart materials.
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Durapatita , Nanocompostos , Durapatita/química , Materiais Biocompatíveis/química , Difração de Raios X , Carbonatos/química , Nanocompostos/químicaRESUMO
Potato is the most consumed vegetable worldwide. Potato tubers contain water, starch, proteins, minerals, and vitamins. The amounts of these chemicals depend on the cultivar and growing location. When potatoes are exposed to high temperatures during the growing period, tuber yield and quality are detrimentally affected; however, there is limited knowledge about the influence of high temperatures on tuber chemical composition. With temperatures rising around the globe, the reaction of potato cultivars to high temperatures is increasingly important, and heat-induced changes, including changes in the chemical composition of tubers, should be considered. The Texas A&M University Potato Breeding Program has been selecting potato clones under high-temperature conditions for many years. Several released cultivars are considered heat-tolerant based on high marketable yields and low internal and external tuber defects. In this study, we used Raman spectroscopy (RS), an analytical tool, to determine whether heat stress causes changes in the chemical composition of tubers of ten potato cultivars. RS is a non-invasive method that requires less time and labor than conventional chemical analysis. We found drastic changes in the intensities of vibrational bands that originate from carbohydrates in the spectra acquired from tubers of heat-stressed plants compared to tubers produced by potato plants grown under normal conditions. These results demonstrate that RS could be used as a replacement or complement to conventional chemical analysis to inspect the effect of heat stress on tuber chemical composition.
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Malnutrition is a major public health concern in many parts of the world. Among other nutrients, minerals are necessary in the human diet. Potato tubers are a good source of minerals; they contribute 18% of the recommended dietary allowance of potassium; 6% of copper, phosphorus, and magnesium; and 2% of calcium and zinc. Increased public interest in improving the nutritional value of foods has prompted the evaluation of mineral content in tubers of advanced genotypes from the Texas A&M Potato Breeding Program and the investigation of the genetics underlying mineral composition in tubers. The objectives of this study were to i) assess phenotypic variation for mineral content in tubers of advanced potato genotypes, ii) identify genomic regions associated with tuber mineral content, and iii) obtain genomic-estimated breeding values. A panel of 214 advanced potato genotypes and reference varieties was phenotyped in three field environments in Texas for the content of 12 minerals in tubers and genotyped using the Infinium Illumina 22K V3 single nucleotide polymorphism (SNP) Array. There was significant variation between potato genotypes for all minerals evaluated except iron. As a market group, red-skinned potatoes had the highest amount of minerals, whereas russets had the lowest mineral content. Reds had significantly higher P, K, S, and Zn than russets and significantly higher P and Mg than chippers. Russets had significantly higher Ca, Mg, and Na than chippers. However, the chippers had significantly higher K than the russets. A genome-wide association study for mineral content using GWASpoly identified three quantitative trait loci (QTL) associated with potassium and manganese content on chromosome 5 and two QTL associated with zinc content on chromosome 7. The loci identified will contribute to a better understanding of the genetic basis of mineral content in potatoes. Genomic-estimated breeding values for mineral macro and micronutrients in tubers obtained with StageWise will guide the selection of parents and the advancement of genotypes in the breeding program to increase mineral content in potato tubers.
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Graphene oxide (GO) nano-powder is synthesized by the modified Hummer's method, and further thin films are deposited by using the water solution of GO through spin-coating. These films are thermally reduced along with the synthesized GO nano-powder at 50 to 200 °C in a high vacuum. Microstructural, electrical, and optical properties are expectedly controlled by thermal reduction. The electronic properties of GO are investigated by X-ray photoelectron spectroscopy and near-edge X-ray absorption fine structure. The reduction is confirmed by Raman spectroscopy. The work function and band gap of GO are tuned with the thermal reduction. The changes in properties of GO are not linear, and anomalous changes are observed for the reduction around 150 °C. Pristine and reduced GO nano-powder is incorporated into TiO2 paste to be the photoanode for dye-sensitized solar cells (DSSCs). It is observed that the performance of the fabricated cells is significantly enhanced for the GO reduced at 150 °C, and the cell exhibited a significant increment of â¼23% for the power conversion efficiency in comparison to DSSC based on an unmodified TiO2 photoanode.
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Carrier dynamics affects photocatalytic systems, but direct and real-time observations in an element-specific and energy-level-specific manner are challenging. In this study, we demonstrate that the dynamics of photo-generated holes in metal oxides can be directly probed by using femtosecond X-ray absorption spectroscopy at an X-ray free-electron laser. We identify the energy level and life time of holes with a long life time (230 pico-seconds) in nano-crystal materials. We also observe that trapped holes show an energy distribution in the bandgap region with a formation time of 0.3 pico-seconds and a decay time of 8.0 pico-seconds at room temperature. We corroborate the dynamics of the electrons by using X-ray absorption spectroscopy at the metal L-edges in a consistent explanation with that of the holes.
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Metal-organic frameworks (MOFs) are broadly known as porous coordination polymers, synthesized by metal-based nodes and organic linkers. MOFs are used in various fields like catalysis, energy storage, sensors, drug delivery etc., due to their versatile properties (tailorable pore size, high surface area, and exposed active sites). This review presents a detailed discussion of MOFs as an electrochemical sensor and their enhancement in the selectivity and sensitivity of the sensor. These sensors are used for the detection of heavy metal ions like Cd2+, Pb2+, Hg2+, and Cu2+ from groundwater. Various types of organic pollutants are also detected from the water bodies using MOFs. Furthermore, electrochemical sensing of antibiotics, phenolic compounds, and pesticides has been explored. In addition to this, there is also a detailed discussion of metal nano-particles and metal-oxide based composites which can sense various compounds like glucose, amino acids, uric acid etc. The review will be helpful for young researchers, and an inspiration to future research as challenges and future opportunities of MOF-based electrochemical sensors are also reported.
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Poluentes Ambientais , Estruturas Metalorgânicas , Metais Pesados , Catálise , Íons , Metais Pesados/químicaRESUMO
BACKGROUND: Diabetes is a major metabolic aggressive disease that has exponentially increased around the globe, including both developed and developing countries. The significant change in the lifestyle of people, attributed to the fast-paced living style and dietary conditions, are a few of the core reasons behind the disease. Multiple studies conducted in various developing countries conclude that patient education, along with adhered practices and attitudinal outlook, can significantly help in deterring the ill effects of diabetes mellitus. OBJECTIVE: The review aimed at understanding the impact of KAP on the management of diabetes mellitus in emerging economies. METHODS: Multi-central analytical cross-sectional and prospective studies were conducted for research in multiple countries with median per capita income of ~$4,000 (developing countries - Ethiopia, Bangladesh, Iraq, Iran, Nigeria, etc.), wherein significant difference was witnessed in the outlook of patients and related stakeholders, who had a decent score of KAP relative to ones with lower scores, towards type 2 diabetes mellitus. RESULTS: Among all the three variables that are capable of managing diabetes - knowledge, attitude and practice (KAP) - knowledge attained a high degree of importance as it served as the initial step to control DM. In developing countries, the ratio of people with knowledge - relating to disease - is significantly dependent on age, socio-economic status and education. As per the previous studies and their corresponding results, educational awareness is of utmost importance in order to eradicate myths and wrong information around the same. CONCLUSION: The review concludes the importance of patient counseling to modify their KAP towards the disease will be highly effective in countries like India, where the count of diabetes mellitus patients is increasing aggressively. Investment in patient counselling to improve their KAP score will significantly help in palliating the effect of this disease.
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Diabetes Mellitus Tipo 2 , Estudos Transversais , Países em Desenvolvimento , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/terapia , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Estudos Prospectivos , Inquéritos e QuestionáriosRESUMO
INTRODUCTION: Psychoactive substance use among medical students is common. This may not only pose a threat to their health and academic performance but may have medico-legal and ethical ramifications. The aim of this study was to find out the prevalence of six psychoactive substances (alcohol, tobacco, cannabis, cocaine, benzodiazepines, opioids) among second year and third year medical students. METHODS: A descriptive cross-sectional study was done in a medical college. Whole sampling was done and ethical approval was taken from the Institutional Review Committee (Reference Number: 54-074/075). The study was conducted from May 2018 to June 2018. A semi-structured self-administered questionnaire modified and adapted from World Health Organization's guidelines for student substance use survey was used to collect data from second year and third year medical students. Statistical Package for Social Sciences version 16.0 was used for analysis. Point estimate at 95% Confidence Interval was calculated along with frequency and proportion for binary data. RESULTS: Out of 226 total respondents, 95 (42.0%) (35.55- 48.45 at 95% Confidence Interval) reported current use of one or more psychoactive substances. Most frequently used substance was alcohol with current use prevalence of 87 (38.5%), followed by smoking 39 (17.3%) and cannabis 27 (11.9%). Cocaine, benzodiazepines and opioids were the least consumed substances with current use prevalence of 2 (0.9%) each. CONCLUSIONS: Almost half of the students were currently using one or more psychoactive substances which is concerning, and therefore strategies must be adopted to alleviate such use.
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Estudantes de Medicina , Transtornos Relacionados ao Uso de Substâncias , Estudos Transversais , Humanos , Prevalência , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , UniversidadesRESUMO
High temperature (heat) stress reduces tuber yield and quality of potatoes. Screening potatoes for heat tolerance is increasingly important, considering the climate change scenario and expansion of potatoes to countries where heat stress is an issue. In vitro screening for tolerance to abiotic stresses offers several advantages, including quick evaluation of numerous genotypes (clones) in reduced space, controlled environmental conditions (temperature and photoperiod), and free from confounding variables inherent to greenhouse and field conditions. In this study, we explored the feasibility of using a temporary immersion bioreactor system for heat tolerance screening of potatoes. We determined the best hormone-free microtuberizing media for this system (MSG with 8% sucrose) to enhance microtuber number and size. Comparisons of microtubers produced at 30°C as heat treatment, with 16°C as normal condition, allowed to identify heat tolerant and susceptible potato clones. The use of bioreactors allowed distinguishing well-formed (non-deformed) from deformed microtubers. Heat stress increased the total biomass of plant tissues in all the clones. However, the effect of heat stress on microtuber number and weight varied among the clones. Incubation at 30°C decreased the weight and number of non-deformed microtubers in all the clones except for Reveille Russet in which the weight of non-deformed microtubers was significantly increased and the count of non-deformed microtubers was not affected. The potato variety Reveille Russet, which was selected under high-temperature field conditions in Texas, had many non-deformed microtubers per explant and the highest microtuber weight among four clones evaluated under heat stress. We described a faster and reliable in vitro microtuberization system for abiotic stress tolerance screening, identified Reveille Russet as a promising heat-tolerant potato variety, and confirmed Russet Burbank and Atlantic as susceptible heat-tolerant checks.
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There is a momentous surge in the development of stem cell technology, such as therapeutic and diagnostic tools. Stem cell-derived cells are currently used in various clinical trials. However, key issues and challenges faced involve the low differentiation efficiency, integration and functioning of transplanted stem cells-derived cells. Extraction of bone marrow, adipose or other mesenchymal stem cells (MSCs) involves invasive methods, specialized skills and expensive technologies. Urine-derived cells, on the other hand, are obtained by non-invasive methods; samples can be obtained repeatedly from patients of any age. Urine-derived cells are used to generate reprogrammed or induced pluripotent stem cells (iPSCs) which can be cultured and differentiated into various types of cell lineages for biomedical investigations and drug testing in vitro or in vivo using model animals of human diseases. Urine cells-derived iPSCs (UiPSCs) have emerged as a major area of research having immense therapeutic significance. Given that preliminary preclinical studies are successful in terms of safety and as a regenerative tool, the UiPSCs will pave the way to the development of various types of autologous stem cell therapies.
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Células-Tronco Pluripotentes Induzidas , Células-Tronco Mesenquimais , Tecido Adiposo , Animais , Diferenciação Celular , Humanos , Medicina RegenerativaRESUMO
We report a case of pulmonary tuberculosis with transaminitis during the presentation but without any pre-existing liver disease or hepatotoxic drug use. This is a fairly common scenario seen in tuberculosis endemic areas; however, this is an under reported condition in the literature and guidelines for its management has not been established. Many clinicians including the authors have treated such cases with modified liver friendly regimens in fear of increasing the hepatotoxicity with standard drugs. However, the modified regimens may not be optimal in treating the underlying tuberculosis. In this report, we gave full dose standard antitubercular drugs, and the liver injury resolved evidenced by normalization of transaminases.
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The hydrogen economy is the key solution to secure a long-term energy future. Hydrogen production, storage, transportation, and its usage completes the unit of an economic system. These areas have been the topics of discussion for the past few decades. However, its storage methods have conflicted for on-board hydrogen applications. In this review, the promising systems based on solid-state hydrogen storage are discussed. It works generally on the principles of chemisorption and physisorption. The usage of hydrogen packing material in the system enhances volumetric and gravimetric densities of the system and helps in improving ambient conditions and system kinetics. Numerous aspects like pore size, surface area ligand functionalization and pore volume of the materials are intensively discussed. This review also examines the newly developed research based on MOF (Metal-Organic Frameworks). These hybrid clusters are employed for nano-confinement of hydrogen at elevated temperatures. A combination of the various methodologies may give another course to a wide scope in the area of energy storage materials later in the future.
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A Li-rich layered oxide (LLO) cathode with morphology-dependent electrochemical performance with the composition Li1.23Mn0.538Ni0.117Co0.114O2 in three different microstructural forms, namely, randomly shaped particles, platelets, and nanofibers, is synthesized through the solid-state reaction (SSR-LLO), hydrothermal method (HT-LLO), and electrospinning process (ES-LLO), respectively. Even though the cathodes possess different morphologies, structurally they are identical. The elemental dispersion studies using energy-dispersive X-ray spectroscopy mapping in scanning transmission electron microscopy show uniform distribution of elements. However, SSR-LLO and ES-LLO nanofibers show slight Co-rich regions. The electrochemical studies of LLO cathodes are evaluated in terms of charging/discharging, C-rate capability, and cyclic stability performances. A high reversible capacity of 275 mA h g-1 is achieved in the fibrous LLO cathode which also demonstrates good high-rate capability (80 mA h g-1 at 10 C-rate). These capacities and rate capabilities are superior to those of SSR-LLO [210.5 mA h g-1 (0.1 C-rate) and 4 mA h g-1 (3 C-rate)] and HT-LLO [242 mA h g-1 (0.1 C-rate) and 22 mA h g-1 (10 C-rate)] cathodes. The ES-LLO cathode exhibits 88% capacity retention after 100 cycles at 1 C-rate. A decrease in voltage on cycling is found to be common in all three cathodes; however, minimal voltage decay and capacity loss are observed in ES-LLO upon cycling. Well-connected small LLO particles constituting fibrous microstructural forms in ES-LLO provide an enhanced electrolyte/cathode interfacial area and reduced diffusion path length for Li+. This, in turn, facilitates superior electrochemical performance of the electrospun Co-low LLO cathode suitable for quick charge battery applications.