<p>Shiv Nadar University is a comprehensive, multidisciplinary, research-focused, and student-centric University offering a full range of academic programs at the undergraduate, postgraduate and doctoral level. With state-of-the-art infrastructure, the University comprises of academic wings, sophisticated labs, international standard sports facilities, amphitheaters, auditorium, conference rooms and smart classrooms. The University&rsquo;s goal is to become internationally recognized for the quality of its research and creative endeavors and their applicability to improving quality of life, generating new insights and expanding the boundaries of human knowledge creativity. Committed to excellence in teaching, research and service, the University aims to serve the higher education needs of India and the world beyond.</p>

Shiv Nadar University

(SoNS) School of Natural Sciences

In this review article, we provide an overview of skyrmion dynamics in the transport behavior of skyrmions based on the existing theoretical and experimental works in addition to the device applications. Swirling spin textures, namely, skyrmions are expected to play extremely important role in future energy efficient spintronic devices. We emphasize specifically on the electrical control of the skyrmion dynamics from the fundamental to application point of view. To begin with, we discuss the role of antisymmetric exchange interaction, namely, the Dzyaloshinskii-Moriya interaction which has its origin in spin-orbit coupling and symmetry breaking at the interface in stabilizing the skyrmion. In-depth understanding of the role of in-plane and out of plane spin torque in governing the skyrmion dynamics is discussed. Importantly, the skyrmion Hall effect, voltage control of skyrmion dynamics, and various important experimental techniques for generating and detecting skyrmion have been elaborated. Given the delicate physics involved with the manipulation and detection of skyrmion, the crucial understanding of the experimental results and theory from the perspective of electrical transport are discussed. Finally, the application of skyrmions in various devices e.g., magnetic memory, transistors and logic gates along with challenges involved are summarized briefly. © 2022 The Electrochemical Society (“ECS”). Published on behalf of ECS by IOP Publishing Limited.

Physics

World University root node

ECS Journal of Solid State Science and Technology

Review—Magnetic Skyrmions in Chiral Ferromagnets: Electrical Transport Properties and Device Applications

The adaptability of the active site to amplify the secondary function is supposed to be the fundamental cause of the promiscuity and the evolution of new functions in enzymes. In most cases, mutations occur close to the active site and/or in the catalytic site to change the active site plasticity to accommodate the non-native substrate. In the present study, using MD simulations and hybrid QM/MM calculations, we have shown a way to enhance the promiscuity, i. e., the allostery-driven promiscuity. Using a case study of the AEE enzyme where the capping loop recognizes the substrate, herein, we show that a single site mutation (D321G) far from the capping loop can induce a large conformational change in the capping loop to recognize different substrates for different functions. The QM/MM calculations for the WT and mutated enzyme provide a first validation of the mechanism of 1,1-proton transfer and dehydration by the AEE enzyme. Since AEE epimerase possesses a highly conserved TIM-barrel fold, we believe that our study provides a crucial lead to understanding the mechanism of emergence of secondary function which can be useful to repurpose ancient enzymes for modern usage. © 2022 Wiley-VCH GmbH.

Chemistry

Fulltext

Chemistry - An Asian Journal

Combined MD and QM/MM Calculations Reveal Allostery-Driven Promiscuity in Dipeptide Epimerases of Enolase Family

The emergence of antimicrobial resistance has raised great concern for public health in many lower-income countries including India. Socio-economic determinants like poverty, health expenditure and awareness accelerate this emergence by influencing individuals' attitudes and healthcare practices such as self-medication. This self-medication practice is highly prevalent in many countries, where antibiotics are available without prescriptions. Thus, complex dynamics of drug- resistance driven by economy, human behaviour, and disease epidemiology poses a serious threat to the community, which has been less emphasized in prior studies. Here, we formulate a game-theoretic model of human choices in self-medication integrating economic growth and disease transmission processes. We show that this adaptive behaviour emerges spontaneously in the population through a self-reinforcing process and continual feedback from the economy, resulting in the emergence of resistance as externalities of human choice under resource constraints situations. We identify that the disparity between social-optimum and individual interest in self-medication is primarily driven by the effectiveness of treatment, health awareness and public health interventions. Frequent multiple-peaks of resistant strains are also observed when individuals imitate others more readily and self-medication is more likely. Our model exemplifies that timely public health intervention for financial risk protection, and antibiotic stewardship policies can improve the epidemiological situation and prevent economic collapse. © 2022 The Authors.

Mathematics

Royal Society Open Science

Disparity in socio-economic status explains the pattern of self-medication of antibiotics in India: Understanding from game-theoretic perspective

Industrial applications of the upcoming class of high-performance biobased polybenzoxazines are currently impeded by the requirement of high polymerization temperatures. Valorization of elemental sulfur (S8), petroleum waste, has provided attractive technological opportunities. However, achieving sulfur copolymers at a low temperature remains a challenging task. Here, a unique facile synthetic strategy was adopted to form a fully sustainable solution-processable benzoxazine-sulfur copolymer via a ring-opening polymerization reaction of isoeugenol-furfurylamine (IE-fa, sourced from naturally abundant biobased feedstocks) and S8at room temperature. The IE-fa benzoxazine monomer was synthesized under neat conditions and reacted with varying percentages of S8as sodium polysulfide (Na2Sx) at unprecedented low temperatures (25 and 50 °C) under catalyst-free conditions. The covalent fixation of sulfur (90 wt %), via inverse vulcanization, within ring-opened benzoxazine resulted in an amorphous copolymer as supported by various techniques. The formation of S-rich and Bz-rich domains in the copolymers is governed by the feed-in ratio of monomers and reaction temperature. Copolymers exhibited high glass transition temperatures (10-86 °C) due to the synergistic effects induced by H-bonded ring-opened benzoxazine structures. The present work demonstrates the first example of benzoxazine as a comonomer to form low-temperature solution-processable benzoxazine sulfur benign random copolymers with mid-wave infrared transparency and may advance benzoxazine chemistry toward transparent optics. © 2022 American Chemical Society. All rights reserved.

ACS Sustainable Chemistry and Engineering

Facile Strategy for Room Temperature Knitting of Sulfur in Polybenzoxazine: A New Class of Solution Processable Copolymers

Large collections of molecules (chemical libraries) are nowadays routinely screened in the process of designing drugs for specific ailments. Chemical and structural similarities between these molecules can be quantified using molecular descriptors, and these similarities can in turn be used to represent any chemical library as an undirected network called a chemical space network (CSN). Here we study different CSNs using conventional graph measures as well as random matrix theory (RMT). For the conventional graph measures, we focus on the average degree, average path length, graph diameter, degree assortativity, transitivity, average clustering coefficient and modularity. For the RMT analyses, we examine the eigenvalue spectra of adjacency matrices constructed from the molecular similarities for different CSNs, and examine their local fluctuation properties, contrasting them with the predictions of RMT. Changes in the conventional graph measures and RMT statistics with the network structure are examined for three different chemical libraries by varying the edge density (fraction of the actual to the maximum possible number of edges) of the networks. It is found that the assortativity among the conventional graph measures, and long-range fluctuation statistics of RMT in eigenvalue space respond to the changes in global network structure as well as the chemical space. We expect that this investigation of the network characteristics of different kinds of chemical libraries will provide guidance in the design of high-throughput screening libraries for different drug design applications. © 2022, The Author(s), under exclusive licence to Springer Nature Switzerland AG.

Journal of Mathematical Chemistry

Investigation of chemical space networks using graph measures and random matrix theory

We investigate the (1 + 1)-dimensional position-dependent mass Dirac equation within the confines of so(2, 1) potential algebra by utilizing the character of a spatial varying Fermi velocity. We examine the combined effects of the two when the Dirac equation is equipped with an external pseudoscalar potential. Solutions of the three cases induced by so(2, 1) are explored by profitably making use of a point canonical transformation. © 2022 IOP Publishing Ltd.

Journal of Physics A: Mathematical and Theoretical

so(2, 1) algebra, local Fermi velocity, and position-dependent mass Dirac equation

This work reports a detailed and systematic theoretical study of the anisotropic thermoelectric properties of bulk Germanium Sulfide (GeS) in its orthorhombic Pnma phase. Density functional theory (DFT), employing the generalized gradient approximation (GGA), has been used to examine the structural and electronic band structure properties of bulk GeS. Electronic transport properties have been studied by solving semiclassical Boltzmann transport equations. A machine-learning approach has been used to estimate the temperature-dependent lattice part of thermal conductivity. The study reveals that GeS has a direct band gap of 1.20 eV. Lattice thermal conductivity is lowest along crystallographic a-direction, with a minimum of ∼0.98 Wm −1 K −1 at 700 K. We have obtained the maximum figure of merit (ZT) ∼ 0.73 at 700 K and the efficiency ∼7.86% in a working temperature range of 300 K-700 K for pristine GeS along crystallographic a-direction. © 2022 IOP Publishing Ltd.

Physica Scripta

A study of anisotropic thermoelectric properties of bulk Germanium Sulfide in its Pnma phase: a combined first-principles and machine-learning approach

A direct functionalization of numerous 1,4-quinones with various aryl boronic acids is reported under blue light-emitting diodes (LEDs). This reaction occurs at room temperature in an open flask without any catalysts, base, and oxidants in acetonitrile (ACN) and is scalable in grams. With diverse 1,4-quinones like 1,4-benzo-, naphtho-, anthra-, and 4-bromonaphthoquinones as substrates, facile cross coupling reactions occur with aryl and alkyl boronic acids without assistance from any photocatalysts. 2-Alkylated cyclohexene-1,4-diones were obtained when the 1,4-quinones were reacted with alkyl boronic acids under standard reaction conditions. However, slight warming of the reaction mixture afforded the desired alkylated 1,4-quinones. The reaction is believed to proceed through the blue LED-induced radical formation of the aryl rings assisted by the 1,4-quinones. © 2022 American Chemical Society. All rights reserved.

Journal of Organic Chemistry

Blue Light-Emitting Diode-Induced Direct C-H Functionalization of 1,4-Quinones with Aryl and Alkyl Boronic Acids

Colorectal cancer typically begins from a nonmalignant polyp formation in the large intestine that, over time, develops into colorectal cancer. The growth of benign polyps can be checked if detected in the early stages of the disease. Doctors usually recommend colonoscopy to average and high-risk individuals for colorectal cancer screening. Elevated carcinoembryonic antigen (CEA) is a broadly used biomarker for colorectal cancer. The genetic and epigenetic alteration of genes such as p53, BRAF, APC, and PIK3CA is also correlated with colorectal cancer in various clinical studies. In general, tissue biopsy is most frequently used for colorectal cancer diagnosis, but the whole tumor heterogeneity cannot be accessed by this technique. Furthermore, such a highly invasive technique is not suitable for repeated testing. Recently, extracellular vesicles (EVs), lipid bilayer enclosed sacs secreted from colorectal cancer cells, are emerging as a diagnostic tool for colon cancer detection. The major advantages of using EVs for colon cancer diagnosis are (i) EVs can be isolated in a noninvasive manner from the body fluid and (ii) EV incorporated cargoes (mostly RNAs) reveal various aspects of colorectal cancer. EV-RNAs are also implicated in tumor invasion and influence the immune system for the further spread of tumors. However, due to the lack of standardized EV detection strategies, diagnostic applicability is limited. Herein, we review the recent literature on the pathobiological dependence of colorectal cancer on EV-RNAs. Further, we present the advantages of identification and characterization of EV-RNAs to explore the connection between differential expression of extracellular vesicle incorporated RNAs and colorectal cancer. How this approach may potentially translate into point of care colorectal cancer diagnostics is also discussed. © 2022 by the Author(s).

ACS Bio and Med Chem Au

Importance of Extracellular Vesicle Derived RNAs as Critical Colorectal Cancer Biomarkers

Vanadium Diselenide (VSe2) is a prominent candidate in the 2D transition metal dichalcogenides family for energy storage applications. Herein, we report the experimental and theoretical investigations on the effect of cobalt doping in 1T-VSe2. The energy storage performance in terms of specific capacitance, stability and energy and power density is studied. It is observed that 3% Co doped VSe2 exhibits better energy storage performance as compared to other concentrations, with a specific capacitance of 1/4193 F g-1 in a two-electrode symmetric configuration. First-principles Density Functional Theory based simulations support the experimental findings by suggesting an enhanced quantum capacitance value after the Co doping in the 1T-VSe2. By making use of the advantages of the specific electrode materials, a solid state asymmetric supercapacitor (SASC) is also assembled with MoS2 as the negative electrode. The assembled Co-VSe2//MoS2 SASC device shows excellent energy storage performance with a maximum energy density of 33.36 Wh kg-1 and a maximum power density of 5148 W kg-1 with a cyclic stability of 90% after 5000 galvano static charge discharge cycles. © 2022 IOP Publishing Ltd.