Evidence of robust 2D transport and Efros-Shklovskii variable range hopping in disordered topological insulator (Bi2Se3) nanowires

We report the experimental observation of variable range hopping conduction in focused-ion-beam (FIB) fabricated ultra-narrow nanowires of topological insulator (Bi2Se3). The value of the exponent in the hopping equation was extracted as ~ 1/2 for different widths of nanowires, which is the proof of the presence of Efros-Shklovskii hopping transport mechanism in a strongly disordered system. High localization lengths (0.5nm, 20nm) were calculated for the devices. A careful analysis of the temperature dependent fluctuations present in the magnetoresistance curves, using the standard Universal Conductance Fluctuation theory, indicates the presence of 2D topological surface states. Also, the surface state contribution to the conductance was found very close to one conductance quantum. We believe that our experimental findings shed light on the understanding of quantum transport in disordered topological insulator based nanostructures.Comment: 14pages, 4 figure

Recent Trends in Development of Metal Nitride Nanocatalysts for Water Electrolysis Application

Nanocatalysts for sustainable water electrolysis is strongly desirable to promote the commercialization of H2 as the alternate clean energy source for the future. The goal is cheaper hydrogen production from sea and low grade water by minimizing the energy consumption and using low cost cell components & non-noble metal catalysts. The conductivity of metal nitrides and their ability to carry out Hydrogen Evolution Reaction and Oxygen Evolution Reaction at relatively low overpotential render these one of the frontline candidates to be potentially utilized as the catalyst for low cost H2 production via electrolysis. In this chapter, the potential of metal nitride catalyst towards fulfilling the above objective is discussed. The synthesis of various metal nitride catalysts, their efficiency towards electrode half reactions and the effectiveness of these class of nanocatalyst for electrolysis of sea water is elaborated. A review of recent literature with special reference to the catalyst systems based on non-noble metals will be provided to assess the likelihood of these nanocatalyst to serve as a commercial grade electrode material for sea water electrolysis

Post COVID-19 multisystem inflammatory syndrome in adults: a new clinical challenge

The spectrum of novel coronavirus disease (COVID-19) continues to evolve since its outbreak in November 2019. Although COVID-19 most commonly causes substantial respiratory pathology, it can also result in several extra pulmonary manifestations. Association between COVID-19 disease and a multisystem inflammatory syndrome in children (MIS-C) and adolescents has now been well defined. However, case reports describing a similar phenomenon in adults are sparse. We presented a case of 42 year old male who presented 3 weeks after initial COVID-19 infection with acute ST elevation myocardial infarction, splenic artery thrombosis, generalized anasarca, with hepatic and renal dysfunction, but minimal respiratory symptoms. He had a turbulent hospital course. However timely suspicion of presence of multisystem inflammatory syndrome in adult (MIS-A) and use of hemoadsorption filters helped to save his life

Human genomic DNA quantitation system, H-Quant: Development and validation for use in forensic casework

The human DNA quantification (H-Quant) system, developed for use in human identification, enables quantitation of human genomic DNA in biological samples. The assay is based on real-time amplification of AluYb8 insertions in hominoid primates. The relatively high copy number of subfamily-specific Alu repeats in the human genome enables quantification of very small amounts of human DNA. The oligonucleotide primers present in H-Quant are specific for human DNA and closely related great apes. During the real-time PCR, the SYBR® Green I dye binds to the DNA that is synthesized by the human-specific AluYb8 oligonucleotide primers. The fluorescence of the bound SYBR® Green I dye is measured at the end of each PCR cycle. The cycle at which the fluorescence crosses the chosen threshold correlates to the quantity of amplifiable DNA in that sample. The minimal sensitivity of the H-Quant system is 7.6 pg/μL of human DNA. The amplicon generated in the H-Quant assay is 216 bp, which is within the same range of the common amplifiable short tandem repeat (STR) amplicons. This size amplicon enables quantitation of amplifiable DNA as opposed to a quantitation of degraded or nonamplifiable DNA of smaller sizes. Development and validation studies were performed on the 7500 real-time PCR system following the Quality Assurance Standards for Forensic DNA Testing Laboratories. Copyright © 2006 by American Academy of Forensic Sciences

Metabolic fingerprinting of joint tissue of collagen-induced arthritis (CIA) rat

Rheumatoid arthritis (RA) is a systemic autoimmune disease whose major characteristics persistent joint inflammation that results in joint destruction and failure of the function. Collagen-induced arthritis (CIA) rat is an autoimmune disease model and in many ways shares features with RA. The CIA is associated with systemic manifestations, including alterations in the metabolism. Nuclear magnetic resonance (NMR) spectroscopy-based metabolomics has been successfully applied to the perchloric acid extract of the joint tissue of CIA rat and control rat for the analysis of aqueous metabolites. GPC (Glycerophosphocholine), carnitine, acetate, and creatinine were important discriminators of CIA rats as compared to control rats. Level of lactate (significance; p = 0.004), alanine (p = 0.025), BCA (Branched-chain amino acids) (p = 0.006) and creatinine (p = 0.023) was significantly higher in CIA rats as compared to control rats. Choline (p = 0.038) and GPC (p = 0.009) were significantly reduced in CIA rats as compared to control rats. Choline to GPC correlation was good and negative (Pearson correlation = -0.63) for CIA rats as well as for control rats (Pearson correlation = -0.79). All these analyses collectively considered as metabolic fingerprinting of the joint tissue of CIA rat as compared to control rat. The metabolic fingerprinting of joint tissue of CIA rats was different as compared to control rats. The metabolic fingerprinting reflects inflammatory disease activity in CIA rats with synovitis, demonstrating that underlying inflammatory process drives significant changes in metabolism that can be measured in the joint tissue. Therefore, the outcome of this study may be helpful for understanding the mechanism of metabolic processes in RA. This may be also helpful for the development of advanced diagnostic methods and therapy for RA

Production of Hydrogen via Water Splitting Using Photocatalytic and Photoelectrocatalytic Route

Hydrogen has been intensively explored recently as an energy carrier to meet the growing demand for green energy across the globe. One of the most difficult and significant subjects in hydrogen energy technology is efficiently creating hydrogen from water by utilizing renewable resources such as solar light. Solar-based hydrogen production comprises several routes, namely, photocatalytic, photoelectrocatalytic, and photobiological decomposition. An efficient photocatalyst is desired to accomplish the above objective by utilizing the first two routes with a minimal rate of recombination of photo-generated charge carriers. In this chapter, strategies for preventing recombination of charge carriers in photocatalysts and the development of photocatalysts have been focused on, and its utilization in the procedure for the production of hydrogen via photocatalytic and photoelectrocatalytic processes is described

Adsorbed Natural Gas Storage for Vehicular Applications

The use of adsorbed natural gas (ANG) as a transportation fuel is a relatively cleaner alternative compared to that of gasoline and is important from the perspective of environmental safety. However, unlike gasoline and diesel, natural gas requires compression, liquefaction, and adsorption techniques for its storage, as it has a very low volumetric energy density. Among all storage techniques, adsorption-based natural gas (ANG) storage is considered as more economical and relatively safe technology due to its mild temperature and pressure conditions for the storage. This chapter will summarize the recent advances in the area of ANG with reference to various synthetic storage materials recently developed for the purpose and their efficiency towards storage and deliverability of natural gas. Particular emphasis will be given to adsorbents based on porous carbon materials, metal organic frameworks, and covalent organic frameworks for the said application. The synthetic procedure for the above adsorbents, followed by their efficiency to store and deliver natural gas, will be discussed. Finally, in the conclusion, the future scope of the technology will be summarized

Multiplex polymerase chain reaction for simultaneous quantitation of human nuclear, mitochondrial, and male Y-chromosome DNA: Application in human identification

Human forensic casework requires sensitive quantitation of human nuclear (nDNA), mitochondrial (mtDNA), and male Y-chromosome DNA from complex biomaterials. Although many such systems are commercially available, no system is capable of simultaneously quantifying all three targets in a single reaction. Most available methods either are not multiplex compatible or lack human specificity. Here, we report the development of a comprehensive set of human-specific, target-specific multiplex polymerase chain reaction (PCR) assays for DNA quantitation. Using TaqMan-MGB probes, our duplex qPCR for nDNA/mtDNA had a linear quantitation range of 100 ng to 1 pg, and our triplex qPCR assay for nDNA/mtDNA/male Y DNA had a linear range of 100-0.1 ng. Human specificity was demonstrated by the accurate detection of 0.05 and 5% human DNA from a complex source of starting templates. Target specificity was confirmed by the lack of cross-amplification among targets. A high-throughput alternative for human gender determination was also developed by multiplexing the male Y primer/probe set with an X-chromosome-based system. Background cross-amplification with DNA templates derived from 14 other species was negligible aside from the male Y assay which produced spurious amplifications from other nonhuman primate templates. Mainstream application of these assays will undoubtedly benefit forensic genomics. © 2004 Elsevier Inc. All rights reserved