210 research outputs found
GaN-based Semiconductor devices with Multichannel Structures
Semiconductor junctions, for example, pn-intersection and Schottky intersection have been very significant as essential components for different semiconductor gadgets. The break-down voltage of the junction PN-intersection relies upon the polluting influence fixations in semiconductors. An opposite voltage is supported in the exhaustion layer thickness which is corresponding to the square of base voltage. The breakdown happens, when the electric field with an intersection arrives at the semiconductor regardless of whether the consumption layer can be extended substantially. To accomplish higher go down voltage, a wide band hole semiconductor, for example, silicon carbide has been examined. The electron gadgets utilizing silicon carbide may undergo serious issues. In any case, the breakdown system of the intersection utilizing silicon carbide is as yet equivalent to that of the conventional junctions. As of late, GaN utilized electron gadgets have developed as cutting-edge high force exchanging gadgets inferable from their high breakdown field. A few papers have revealed that GaN-based HFETs is directly expanded by expanding the junction dividing between the door and channel electrodes. This conduct is unique in relation to that of the customary junctions
PHYTOCHEMICAL STUDIES AND PHARMACOGNOSTICAL EVALUATION OF ZINGIBER CASSUMUNAR ROXB
  Objective: Zingiber Cassumunar Roxb is a well known medicinal plant employed to cure various diseases were reported to possess good medicinal value in traditional system of medicine. The present investigation deals with microscopic, macroscopic and preliminary phytochemical investigation of rhizome to give clear standards for identification of the drug.Method: For the microscopic evaluation, the powder was soaked in a solution of 20% chloral hydrate and then mounted on a glass slide with the help of glycerine. The mounted slides were then observed under a photographic microscope. Microscopic sections were cut by free hand sectioning.Result: The research paper study revealed that the yellow colour inside the rhizome is the main characteristic feature. The presence of central cylinder region containing yellow coloured oleo-resin and oil cells in cortex are the main characteristic feature. The presence irregularly rounded, ovoid starch grains and oil globulues situtated inside the parenchyma are the distinguishing features and can be used as anatomical markers. Rhizome powder showed some of the characteristic features such as starch grains with a rounded shape situated at narrow end and parenchymatous cells with characteristically wrinkled wall, air spaces. Cork, cortex, cork cells, and floem fibres also shows pharmacognostical characteristics of Z. cassumunar Roxb. Preliminary phytochemical analysis of the rhizomes revealed the presence of glycosides, sterols, triterpenes, saponins, tannins, flavonoids, amino acids and volatile oils.Conclusion:The present study signifies the use of TLC (Thin layer chromatography) profiles for determining the identity of active chemical constituents
AutoCure: Automated Tabular Data Curation Technique for ML Pipelines
Machine learning algorithms have become increasingly prevalent in multiple
domains, such as autonomous driving, healthcare, and finance. In such domains,
data preparation remains a significant challenge in developing accurate models,
requiring significant expertise and time investment to search the huge search
space of well-suited data curation and transformation tools. To address this
challenge, we present AutoCure, a novel and configuration-free data curation
pipeline that improves the quality of tabular data. Unlike traditional data
curation methods, AutoCure synthetically enhances the density of the clean data
fraction through an adaptive ensemble-based error detection method and a data
augmentation module. In practice, AutoCure can be integrated with open source
tools, e.g., Auto-sklearn, H2O, and TPOT, to promote the democratization of
machine learning. As a proof of concept, we provide a comparative evaluation of
AutoCure against 28 combinations of traditional data curation tools,
demonstrating superior performance and predictive accuracy without user
intervention. Our evaluation shows that AutoCure is an effective approach to
automating data preparation and improving the accuracy of machine learning
models
Natural Products in Drug Discovery
Drug discovery using natural products is a challenging task for designing new leads. It describe the bioactive compounds derived from natural resources, its phytochemical analysis, characterization and pharmacological investigation. It focuses on the success of these resources in the process of finding and discovering new and effective drug compounds that can be useful for human resources. From many years, natural products have been acting as a source of therapeutic agents and have shown beneficial uses. Only natural product drug discovery plays an important role to develop the scientific evidence of these natural resources. Research in drug discovery needs to develop robust and viable lead molecules, which step forward from a screening hit to a drug candidate through structural elucidation and structure identification through GC–MS, NMR, IR, HPLC, and HPTLC. The development of new technologies has revolutionized the screening of natural products in discovering new drugs. Utilizing these technologies gives us an opportunity to perform research in screening new molecules using a software and database to establish natural products as a major source for drug discovery. It finally leads to lead structure discovery. Powerful new technologies are revolutionizing natural herbal drug discovery
The Critically Endangered Forest Owlet Heteroglaux Blewitti is Nested Within the Currently Recognized Athene Clade: A Century-Old Debate Addressed
Range-restricted species generally have specific niche requirements and may often have unique evolutionary histories. Unfortunately, many of these species severely lack basic research, resulting in poor conservation strategies. The phylogenetic relationship of the Critically Endangered Forest Owlet Heteroglaux blewitti has been the subject of a century-old debate. The current classifications based on non-phylogenetic comparisons of morphology place the small owls of Asia into three genera, namely, Athene, Glaucidium, and Heteroglaux. Based on morphological and anatomical data, H. blewitti has been alternatively hypothesized to belong within Athene, Glaucidium, or its own monotypic genus Heteroglaux. To test these competing hypotheses, we sequenced six loci (~4300 bp data) and performed phylogenetic analyses of owlets. Mitochondrial and nuclear trees were not congruent in their placement of H. blewitti. However, both mitochondrial and nuclear combined datasets showed strong statistical support with high maximum likelihood bootstrap (\u3e/ = 90) and Bayesian posterior probability values (\u3e/ = 0.98) for H. blewitti being nested in the currently recognized Athene group, but not sister to Indian A. brama. The divergence of H. blewitti from its sister taxa was between 4.3 and 5.7 Ma coinciding with a period of drastic climatic changes in the Indian subcontinent. This study presented the first genetic analysis of H. blewitti, a Critically Endangered species, and addressed the long debate on the relationships of the Athene-Heteroglaux-Glaucidium complex. We recommend further studies with more data and complete taxon sampling to understand the biogeography of Indian Athene species
In Silico Derivation of HLA-Specific Alloreactivity Potential from Whole Exome Sequencing of Stem Cell Transplant Donors and Recipients: Understanding the Quantitative Immuno-biology of Allogeneic Transplantation
Donor T cell mediated graft vs. host effects may result from the aggregate
alloreactivity to minor histocompatibility antigens (mHA) presented by the HLA
in each donor-recipient pair (DRP) undergoing stem cell transplantation (SCT).
Whole exome sequencing has demonstrated extensive nucleotide sequence variation
in HLA-matched DRP. Non-synonymous single nucleotide polymorphisms (nsSNPs) in
the GVH direction (polymorphisms present in recipient and absent in donor) were
identified in 4 HLA-matched related and 5 unrelated DRP. The nucleotide
sequence flanking each SNP was obtained utilizing the ANNOVAR software package.
All possible nonameric-peptides encoded by the non-synonymous SNP were then
interrogated in-silico for their likelihood to be presented by the HLA class I
molecules in individual DRP, using the Immune-Epitope Database (IEDB) SMM
algorithm. The IEDB-SMM algorithm predicted a median 18,396 peptides/DRP which
bound HLA with an IC50 of <500nM, and 2254 peptides/DRP with an IC50 of <50nM.
Unrelated donors generally had higher numbers of peptides presented by the HLA.
A similarly large library of presented peptides was identified when the data
was interrogated using the Net MHCPan algorithm. These peptides were uniformly
distributed in the various organ systems. The bioinformatic algorithm presented
here demonstrates that there may be a high level of minor histocompatibility
antigen variation in HLA-matched individuals, constituting an HLA-specific
alloreactivity potential. These data provide a possible explanation for how
relatively minor adjustments in GVHD prophylaxis yield relatively similar
outcomes in HLA matched and mismatched SCT recipients.Comment: Abstract: 235, Words: 6422, Figures: 7, Tables: 3, Supplementary
figures: 2, Supplementary tables:
Effects of heat treatment on the atomic structure and surface energy of rutile and anatase TiO2 nanoparticles under vacuum and water environments
Nanomaterials have become a widely used group of materials in many chemical engineering applications owing to their ability to provide an enhanced level of functional properties compared to their crystalline and bulk counterparts. Here we report fundamental level advancements on how the anatase and rutile phase of TiO2 nanoparticles chemo-thermally respond between room temperature and the melting temperature under both vacuum and water environments. The current study is based on using molecular dynamics (MD) simulations. We present results on the equilibrium crystal morphology of these phases, structural and surface energy of TiO2 nanoparticles in the size range of 2-6 nm under different temperatures. Thermodynamic and structural properties, in the form of potential energy and Radial Distribution Functions (RDF’s) respectively, are calculated for both forms of TiO2 nanoparticles. The temperature associated with the melting transition increased with an increase in the particle size in both the phases. The potential energy change associated with the melting transition for anatase was seen to be less than that for rutile nanoparticles. Also the temperature at which the RDF’s began to stretch and broaden was observed to be lower for the case of anatase than rutile, suggesting that rutile attains the most thermal stable phase for the nano particle sizes considered in this study. Structural changes in anatase and rutile nanoparticles under different temperatures revealed that non-spherical (rod-like) rutile nanoparticles tend to be thermodynamically more stable. Surface energy influences the shape of TiO2 nanoparticles at different temperatures. The increase in the surface energy of nanoparticles under vacuum when compared with that of water environment is higher for the anatase phase than the rutile phase of nanoparticle sizes studied here. The fundamental level simulation results reported here provide a strong platform for potentially accounting for the effects of atomic-scale phase characteristics of TiO2 nanoparticles and surface energy under different temperature fields in nano processing applications and related multi-scale modelling approaches in future
Determining the Quantitative Principles of T Cell Response to Antigenic Disparity in Stem Cell Transplantation
Alloreactivity compromising clinical outcomes in stem cell transplantation is observed despite HLA matching of donors and recipients. This has its origin in the variation between the exomes of the two, which provides the basis for minor histocompatibility antigens (mHA). The mHA presented on the HLA class I and II molecules and the ensuing T cell response to these antigens results in graft vs. host disease. In this paper, results of a whole exome sequencing study are presented, with resulting alloreactive polymorphic peptides and their HLA class I and HLA class II (DRB1) binding affinity quantified. Large libraries of potentially alloreactive recipient peptides binding both sets of molecules were identified, with HLA-DRB1 generally presenting a greater number of peptides. These results are used to develop a quantitative framework to understand the immunobiology of transplantation. A tensor-based approach is used to derive the equations needed to determine the alloreactive donor T cell response from the mHA-HLA binding affinity and protein expression data. This approach may be used in future studies to simulate the magnitude of expected donor T cell response and determine the risk for alloreactive complications in HLA matched or mismatched hematopoietic cell and solid organ transplantation
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