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I would like to out-line the Hawking radiation phenomenon from a macroscopic black hole using the Schwinger pair production mechanism established in quantum field theory. The underlying scenario is revisited with a higher form (Kalb–Ramond) dynamics in presence of a background pure de Sitter in a U(1) gauge theory on a D4-brane. The absorption of higher form quanta, by the vacuum/black hole in a pair production scenario, is addressed appropriately when the three form field strength is replaced with a gauge connection to construct a new covariant derivative. The emergent quantum gravity is shown to be described by a geometric torsion curvature in a second order formalism. We obtain quantum de Sitter and anti de Sitter patches, and their geometric projection, in a brane window on a vacuum created pair of 4-brane and anti 4-brane. We perform thermal analysis and discuss some aspects of the Schwarzschild de Sitter tunnelling to a Nariai vacuum.

Topological quantum phase transitions (TQPTs) in a material induced by external perturbations are often characterized by band touching points in the Brillouin zone. The low-energy excitations near the degenerate band touching points host different types of fermions while preserving the topological protection of surface states. An interplay of different tunable topological phases offers an insight into the evolution of the topological character. In this paper, we study the occurrence of TQPTs as a function of hydrostatic pressure in CdGeSb$_2$ and CdSnSb$_2$ chalcopyrites, using the first-principles calculations. At ambient pressure, both materials are topological insulators having a finite band gap with inverted order of Sb-$s$ and Sb-$p_x$,$p_y$ orbitals of valence bands at the $\Gamma$ point. On the application of hydrostatic pressure the band gap reduces, and at the critical point of the phase transition, these materials turn into Dirac semimetals. On further increasing the pressure beyond the critical point, the band inversion is reverted making them trivial insulators. The pressure-induced change in band topology from non-trivial to trivial phase is also captured by L\"{u}ttinger model Hamiltonian calculations. Our model demonstrates the critical role played by a pressure-induced anisotropy in frontier bands in driving the phase transitions. These theoretical findings of peculiar coexistence of multiple topological phases in the same material provide a realistic and promising platform for the experimental realization of the TQPT., Comment: 7 pages, 7 figures

High-temperature stable transition metal carbides are one of the promising classes of materials for next-generation energy applications such as water splitting catalysis and electrodes for energy storage devices. Herein, origami-like molybdenum carbide flakes with interfacially connected structures in various orientations using an easily scalable chemical vapor deposition method are synthesized. Interestingly, each individual flake of similar orientation is interconnected across different planes. The interconnected architectures are found to be highly elastic and behave in a sponge-like manner. In addition, the surface energy of each plane is calculated using the first-principle density functional theory. The molybdenum carbide shows excellent activity for the hydrogen evolution reaction, with the onset over potential occurring around ?16 to ?25 mV with high stability. The material is used as an electrode for supercapacitors as a second demonstration. The supercapacitor constructed with polypyrrole reaches the specific capacitance of ?279 F g?1 at a current density of 0.5 A g?1., by Ryota Koizumi, Sehmus Ozden, Atanu Samanta, Ana Paula P. Alves, Avanish Mishra, Gonglan Ye, Glaura G. Silva, Robert Vajtai, Abhishek K. Singh, Chandra S. Tiwary and Pulickel M. Ajayan

I briefly review an emergent gravity scenario underlying a stringy pair production of brane/anti-brane universe by a KR field quanta on a \(D_4\)- barne. We obtain a generic family of ’quantum’ degenerate black holes in the emergent gravity underlying a dynamical Neveu-Schwarz (NS) field on a vacuum created stringy pair of a \((3{\bar{3}})\)-brane. In a low energy (GTR) limit the degeneracy disappear and the reduced vauca describe the Kerr family of macroscopic black holes in 4D.

Late-transition-metal-doped Pt clusters are prevalent in CO oxidation catalysis, as they exhibit better catalytic activity than pure Pt, while reducing the effective cost and poisoning. However, completely eliminating the critical problem of Pt poisoning still poses a big challenge. Here, we report for the first time that, among the bimetallic clusters ((Pt3M where M = Co, Ni, and Cu)/MgO(100)), the CO adsorption site inverts for Pt3Co/MgO(100) from Pt to Co, due to the complete uptake of Pt d-states by lattice oxygen. While this resolves the problem of Pt poisoning, good reaction kinetics are predicted through low barriers for Langmuir–Hinshelwood and Mars van Krevelen (MvK) mechanisms of CO oxidation for Pt3Co/MgO(100) and Li-doped MgO(100), respectively. Li doping in MgO(100) compensates for the charge imbalance caused by a spontaneous oxygen vacancy formation. Pt3Co/Li-doped MgO(100) stands out as an exceptional CO oxidation catalyst, giving an MvK reaction barrier as low as 0.11 eV. We thereby propos...

By combining first principles density functional theory and electronic as well as lattice Boltzmann transport calculations, we unravel the excellent thermoelectric properties of Zintl phase compounds ACd2Sb2 (where, A = Ca, Ba, Sr). The calculated electronic structures of these compounds show charge carrier pockets and heavy light bands near the band edge, which lead to a large power factor. Furthermore, we report large Grüneisen parameters and low phonon group velocity indicating essential strong anharmonicity in these compounds, which resulted in low lattice thermal conductivity. The combination of low thermal conductivity and the excellent transport properties give a high ZT value of ∼1.4-1.9 in CaCd2Sb2 and BaCd2Sb2 at moderate p and n-type doping. Our results indicate that well optimized Cd-based Zintl phase compounds have the potential to match the performance of conventional thermoelectric materials.

Hydrogen storage capacity of Tin-1B (n = 3-7) clusters is studied and compared with that of the pristine Ti-n (n = 3-7), using density functional theory (DFT) based calculations. Among these clusters, Ti3B shows the most significant enhancement in the storage capacity by adsorbing 12 H-2, out of which three are dissociated and the other nine are stored as dihydrogen via Kubas-interaction. The best storage in Ti3B is owed to a large charge transfer from Ti to B along with the largest distance of Ti empty d-states above the Fermi level, which is a distinct feature of this particular cluster. Furthermore, the effect of substrates on the storage capacity of Ti3B was assessed by calculating the number of adsorbed H-2 on Ti-3 cluster anchored onto B atoms in the B-doped graphene, BC3, and BN substrates. Similar to free-standing Ti3B, Ti-3 anchored onto boron atom in BC3, stores nine di-hydrogen via Kubas interaction, at the same time eliminating the total number of non-useful dissociated hydrogen. Gibbs energy of adsorption as a function of H-2 partial pressure, indicated that at 250 K and 300 K the di-hydrogens on Ti-3@BC3 adsorb and desorb at ambient pressures. Importantly, Ti-3@BC3 avoids the clustering, hence meeting the criteria for efficient and reversible hydrogen storage media. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

There is great interest in developing promising candidate materials for high-capacity, low cost, environmentally friendly, longer cycle life anodes for lithium ion batteries. Due to better Li adsorption properties than graphene, boron doped graphene has been considered to be an attractive anode material for Li-ion batteries. Using first principles density functional theory calculations, we investigate the effect of increasing boron concentration on the gravimetric capacity of monolayered boron doped carbon sheets. The calculations are performed for uniformly boron doped carbon sheets, BC

A strategic approach toward functionalization can change properties: effect of the “oxidizer of oxygen” on hexagonal boron nitride., We report the fluorination of electrically insulating hexagonal boron nitride (h-BN) and the subsequent modification of its electronic band structure to a wide bandgap semiconductor via introduction of defect levels. The electrophilic nature of fluorine causes changes in the charge distribution around neighboring nitrogen atoms in h-BN, leading to room temperature weak ferromagnetism. The observations are further supported by theoretical calculations considering various possible configurations of fluorinated h-BN structure and their energy states. This unconventional magnetic semiconductor material could spur studies of stable two-dimensional magnetic semiconductors. Although the high thermal and chemical stability of h-BN have found a variety of uses, this chemical functionalization approach expands its functionality to electronic and magnetic devices.

Monoclinic materials viz. quartz, lithium niobate and lithium tantalate are among the most abundant materials, finding numerous applications throughout the technological world. Moreover, the presence of irregularity, initial stresses, anisotropy and heterogeneity in a material medium is obvious. These facts motivate the study of magnetoelastic SH-wave propagation in an irregular monoclinic sandwiched layer between a heterogeneous isotropic layer and an isotropic half space, all under initial stress. The heterogeneity in the uppermost layer is caused due to exponential variation in rigidity, density and initial stress in terms of space variable pointing vertically downward. The dispersion relation has been obtained using first-order perturbation technique. The substantial effect of wave number, anisotropy, irregularity, width ratio of the layers, horizontal compressive/tensile initial stresses, heterogeneity and monoclinic-magnetoelastic coupling parameter associated with sandwiched layer on phase velocity of SH-wave has been studied and depicted by means of graph. Comparative study made for the case when pre-stressed irregular sandwiched layer is monoclinic-magnetoelastic to the case when it is isotropic magnetoelastic layer is one of the major highlights of the current study.

Among the large number of promising two-dimensional (2D) atomic layer crystals, true metallic layers are rare. Using combined theoretical and experimental approaches, we report on the stability and successful exfoliation of atomically thin "gallenene" sheets on a silicon substrate, which has two distinct atomic arrangements along crystallographic twin directions of the parent ?-gallium. With a weak interface between solid and molten phases of gallium, a solid-melt interface exfoliation technique is developed to extract these layers. Phonon dispersion calculations show that gallenene can be stabilized with bulk gallium lattice parameters. The electronic band structure of gallenene shows a combination of partially filled Dirac cone and the nonlinear dispersive band near the Fermi level, suggesting that gallenene should behave as a metallic layer. Furthermore, it is observed that the strong interaction of gallenene with other 2D semiconductors induces semiconducting to metallic phase transitions in the latter, paving the way for using gallenene as promising metallic contacts in 2D devices., by Vidya Kochat, Atanu Samanta, Yuan Zhang, Sanjit Bhowmick, Praveena Manimunda, Syed Asif S. Asif, Anthony S.Stender, Robert Vajtai, Abhishek K. Singh, Chandra S. Tiwary and Pulickel M. Ajayan

The presence of ferroelectric polarization in 2D materials is extremely rare due to the effect of the surface depolarizing field. Here, we use first-principles calculations to show the largest out-of-plane polarization observed in a monolayer in functionalized MXenes (Sc2CO2). The switching of polarization in this new class of ferroelectric materials occurs through a previously unknown intermediate antiferroelectric structure, thus establishing three states for applications in low-dimensional nonvolatile memory. We show that the armchair domain interface acts as an 1D metallic nanowire separating two insulating domains. In the case of the van der Waals bilayer we observe, interestingly, the presence of an ultrathin 2D electron/hole gas (2DEG) on the top/bottom layers, respectively, due to the redistrubution of charge carriers. The 2DEG is nondegenerate due to spin–orbit coupling, thus paving the way for spin–orbitronic devices. The coexistence of ferroelectricity, antiferroelectricity, 2DEG, and spin–orbi...

A new class of twinned amphiphiles was developed by conjugating a pair of hydrophilic head groups from mPEG chains (Mn : 350 or 1000) and a pair of hydrophobic segments from linear alkyl chains (C11 or C18 ) through a novel spacer synthesized from glycerol and p-hydroxybenzoic acid. The aggregation phenomena of the amphiphiles were proven by DLS and fluorescence experiments, whereas size and morphology of the aggregates were evaluated by cryo-TEM. The measurements proved the formation of globular, thread-like or rod-like micelles as well as planar double-layer assemblies, depending on the amphiphile's molecular structure. The applicability of these non-ionic amphiphilic systems as nanocarriers for hydrophobic guest molecules was demonstrated by encapsulating a hydrophobic dye, Nile Red, and a hydrophobic drug, Nimodipine. The transport capacity results for both Nimodipine and Nile Red prove them as a promising candidate for drug delivery.

The first aim of this paper is to present the issue of apparel retailing in India with the simultaneous determination of barriers to positioning strategy implementation. Second, measure the causality, comparative strength and network structure of the barriers in the way of successful strategy implementation. Key barriers identified with the help of literature review from peer-reviewed papers and validated by experts. Grey theory employed to refine the opinions collected from experts then employed DEMATEL to quantitatively calculate the importance, causality, comparative strength and effect in the interaction among barriers. This paper has identified 17 implementation barriers of competitive positioning strategy which hinders successful implementation of strategy in the apparel retail stores. Further, cause/effect relationships among these barriers have been developed using grey-DEMATEL approach. This research is highly noteworthy for apparel retailers to position their stores in the competitive market and eradicate the main barriers with the help of systematic approach.

Purpose: In India, head and neck cancer contributes to about 35% of all malignancies. Among head and neck squamous cell cancers, buccal mucosa and tongue are the most common subsites. Reconstruction of defects after resection of primary in these subsites with acceptable cosmetic and functional outcomes remains a challenging task. In the era of free flaps, many pedicled flaps are being overlooked. Infrahyoid flap (IHF) is one among them. This study discusses the feasibility of IHF in reconstruction of small and medium-sized defects in subsites of the oral cavity. Materials and Methods: This study is a retrospective analysis of 23 patients who underwent IHF and reconstruction after excision of primary in a case of oral cavity squamous cell carcinoma from January 2010 till November 2017 with a median follow-up of 15 months. Patients who were diagnosed as a case of squamous cell carcinoma in oral cavity subsites (T1–T3 and N0/N1–N2) and in whom the anticipated defect size was small to medium were included. The evaluation was then done based on the possibility to reach recipient site, vitality after transposition, definitive integration, and clinical outcome. Results: Out of 23 patients, 5 patients had flap-related complications of which 1 patient had total skin paddle necrosis and 4 patients had partial skin paddle necrosis at distal end. However, no patient developed oro-cutaneous fistula or required corrective surgery. The maximum flap dimension was 9 × 4 cm and average flap dimension was 6 × 4 cm. The postoperative outcome of all patients remained uneventful. Conclusion: The infrahyoid myocutaneous flap is a reliable and convenient flap which can be used as a good alternative for free flaps in small and medium-sized defects of the oral cavity.

Controlling the band gap by tuning the lattice structure through pressure engineering is a relatively new route for tailoring the optoelectronic properties of two-dimensional (2D) materials. Here, we investigate the electronic structure and lattice vibrational dynamics of the distorted monolayer 1T-MoS2 (1T') and the monolayer 2H-MoS2 via a diamond anvil cell (DAC) and density functional theory (DFT) calculations. The direct optical band gap of the monolayer 2H-MoS2 increases by 11.7% from 1.85 to 2.08 eV, which is the highest reported for a 2D transition metal dichalcogenide (TMD) material. DFT calculations reveal a subsequent decrease in the band gap with eventual metallization of the monolayer 2H-MoS2, an overall complex structure-property relation due to the rich band structure of MoS2. Remarkably, the metastable 1T'-MoS2 metallic state remains invariant with pressure, with the J2, A1g, and E2g modes becoming dominant at high pressures. This substantial reversible tunability of the electronic and vibrational properties of the MoS2 family can be extended to other 2D TMDs. These results present an important advance toward controlling the band structure and optoelectronic properties of monolayer MoS2 via pressure, which has vital implications for enhanced device applications.

Infectious diseases and the development of their resistance to antimicrobial agents are alarming issues worldwide and consistent efforts are being made to develop efficient antimicrobial agents. In this perspective, a series of novel ammonium and amide derivatives of pyranocoumarin and coumarin were synthesized and evaluated for their antimicrobial activity. Among them, six compounds exhibited significant activity against gram-positive bacteria Bacillus cereus (MTCC 430) and Bacillus subtilis (MTCC 121) and a gram-negative bacterium Pseudomonas aeruginosa (MTCC 741). The compound N,N,N-triethyl-10-(4,8,8-trimethyl-2-oxo-2,6,7,8-tetrahydropyrano[3,2-g]chromen-10-yloxy)decan-1-aminium bromide (16) exhibited the highest antibacterial activity with MIC value of 5 μg/ml in MDA. Compounds 17 and 18 exhibited modest antifungal activity with MIC of 6.25 μg/ml against Trichophyton rubrum (clinical isolate) in MDA. Haemolytic assay results demonstrated that three out of six compounds were safe at their respective MIC values. These results provide insights for further optimization of the scaffolds for designing the next generation of compounds as lead antimicrobial agents.

To evaluate first and second order responses on multifocal electroretinogram (mfERG) and with retinal nerve fibre layer thickness (RNFL) on Cirrus spectral domain optical coherence tomography (SD-OCT) in glaucoma.Patients (old and new) diagnosed with primary open angle glaucoma, primary angle closure glaucoma or normal tension glaucoma attending glaucoma services from November 2012 to January 2013 were screened. Ninety-seven eyes fulfilling inclusion criteria were evaluated by Humphrey visual field, Cirrus SD-OCT imaging and mfERG (Veris Science 5.1.10X; EDI, Redwood City, California, USA) for this observational cross-sectional study. The global and averaged quadrant-wise peak-to-trough amplitudes and peak implicit times of the first trough (N1), the first peak (P1) and the second trough (N2) of the mfERG were compared with average RNFL-full circle (FC) or quadrant RNFL thickness in early (mean deviation (MD)-6 dB), moderate (MD -6 to -12 dB) and advanced glaucoma (MD-12 dB).The RNFL-FC correlated with P1N2 amplitude on univariate analysis (r=0.7, p=0.004) and N2 amplitude (r=-0.4, p0.001). Comparing relationships in different stages of glaucoma, P1N2 amplitude correlated significantly with RNFL-FC and superotemporal quadrant, RNFL-superior temporal (ST), in early and moderate glaucoma only. In contrast, the implicit time of P1N2 correlated significantly with RNFL-FC and RNFL-ST only in severe glaucoma while in earlier stages, this relationship did not hold true. On multivariate analysis, P1N2 amplitude correlated with age (β=-0.2, p0.001), RNFL-FC (β=0.05, p=0.05), RNFL-ST (β=0.06, p=0.01) and cup-disc ratio (β=-3.2, p=0.006).Of all responses on mfERG, P1N2 amplitude correlates well with RNFL-FC and RNFL-ST on SD-OCT and can be used for monitoring early and moderate glaucoma. Diffuse structural changes may best be reflected by changes in P1N2 implicit time owing to ceiling effect of the amplitude in all regions in severe glaucoma.

Due to the ease of modification of electronic structure upon analyte adsorption, semiconductors have been the preferred materials as chemical sensors. At reduced dimension, however, the sensitivity of semiconductor-based sensors deteriorates significantly due to passivation, and often by increased band gap caused by quantum confinement. Using first-principles density functional theory combined with Boltzmann transport calculations, we demonstrate semiconductor-like sensitivity toward chemical species in ultrathin gold nanowires (AuNWs). The sensing mechanism is governed by the modification of the electronic structure of the AuNW as well as scattering of the charge carriers by analyte adsorption. Most importantly, the sensitivity exhibits a linear relationship with the electron affinities of the respective analytes. Based on this relationship, we propose an empirical parameter, which can predict an analyte-specific sensitivity of a AuNW, rendering them as effective sensors for a wide range of chemical anal...

A detailed understanding of structure and stability of nanowires is critical for applications. Atomic resolution imaging of ultrathin single crystalline Au nanowires using aberration-corrected microscopy reveals an intriguing relaxation whereby the atoms in the close-packed atomic planes normal to the growth direction are displaced in the axial direction leading to wrinkling of the (111) atomic plane normal to the wire axis. First-principles calculations of the structure of such nanowires confirm this wrinkling phenomenon, whereby the close-packed planes relax to form saddle-like surfaces. Molecular dynamics studies of wires with varying diameters and different bounding surfaces point to the key role of surface stress on the relaxation process. Using continuum mechanics arguments, we show that the wrinkling arises due to anisotropy in the surface stresses and in the elastic response, along with the divergence of surface-induced bulk stress near the edges of a faceted structure. The observations provide new understanding on the equilibrium structure of nanoscale systems and could have important implications for applications in sensing and actuation.

Herein, we report on the synthesis of PEG-1000-diethyl ester and 2-azido-propane-1,3-diol-based copolymers utilizing Novozym 435 (Candida antarctica lipase) using a biocatalytic method. The linear base copolymer was then functionalized with polyglycerol-based regular [G1.0] and [G2.0] dendrons and C12/C14 hydrophobic alkyl chains via an efficient “Click approach.” The resulting amphiphilic dendronized polymers form well-defined micelles in aqueous solutions. The transport behavior of these polymers was studied by using Nile red as a fluorescent model dye. The cytotoxicity profiles of a few representative polymers were evaluated, and the effect of hydrophobic alkyl chain length as well as the hydrophilic polyglycerol dendron's generation on the biocompatibility of polymeric systems was studied. Copyright © 2014 John Wiley & Sons, Ltd.

Using first principles calculations, we show that the storage capacity as well as desorption temperature of MOFs can be significantly enhanced by decorating pyridine (a common linker in MOFs) by metal atoms. The storage capacity of metal-pyridine complexes are found to be dependent on the type of decorating metal atom. Among the 3d transition metal atoms, Sc turns out to be the most efficient storing unto four H 2 molecules. Most importantly, Sc does not suffer dimerisation on the surface of pyridine, keeping the storage capacity of every metal atom intact. Based on these findings, we propose a metal-decorated pyridine-based MOFs, which has potential to meet the required H 2 storage capacity for vehicular usage.

Inhibition mechanism(s) of protein kinase B/Akt1 and its consequences on related cell signaling were investigated in human neuroblastoma SH-SY5Y cells exposed to 4-hydroxy-trans-2-nonenal (4-HNE), one of the most reactive aldehyde by-products of lipid peroxidation. In silico data indicate that 4-HNE interacts with kinase domain of Akt1 with the total docking score of 6.0577 and also forms H-bond to Glu234 residue similar to highly potent Akt1 inhibitor imidazopiperidine analog 8b, in which the protonated imidazole nitrogen involves in two hydrogen bonds between Glu234 and Asp292. The strong hydrogen bonding with Glu234 and hydrophobic interactions with several residues, namely Leu156, Gly157, Val164, Ala177, Tyr229, Ala230, Met281 and Thr291, at the vicinity which is normally occupied by the ribose of ATP, appear to be the main causes of Akt1 inhibition and lead to the significant conformational change on this region of protein. Results of mutational docking prove that Glu234 plays a major role in 4-HNE-mediated Akt1 inhibition. In silico data on Akt inhibition were further validated by observing the down-regulated levels of phosphorylated (Thr308/Ser493) Akt1 as well as the altered levels of the downstream targets of pAkt, namely downregulated levels of pGSK3β (Ser9), β-catenin, Bcl2 and upregulated levels of pro-apoptotic markers, namely Bad, Bax, P(53) and caspase-9/3. The cellular fate of such pAkt inhibition was evidenced by increased reactive oxygen species, degraded nuclei, transferase dUTP nick end labeling positive cells and upregulated levels of pJNK1/2. We identified that 4-HNE-mediated Akt1 inhibition was due to the competitive inhibition of ATP by 4-HNE at the kinase domain of ATP binding sites.

Solution processable poly[2,5-bis(3-tetradecylthiophen-2-yl)thieno[3,2-b]thiophene] (PBTTT- C14) organic polymer-light based field effect transistor (O-L-FET) has been developed for low-cost and large-area electronics applications. We have fabricated and studied the electrical as well as the optical performance of a p-channel PBTTT-C14 organic polymer-based thin film transistor under dark and steady-state illumination. Also, a model has been developed for understanding the device physics particularly, focusing on the impact of illumination on polymer/dielectric and metal-polymer interface. It has been intended to investigate the effect of green light on organic thin film transistor. An enhancement in the photogenerated charge carrier in the organic channel under green light (550 nm) illumination was observed, which is attributed to the absorption of photons and photogeneration of excitons followed by their diffusion and dissociation. A comprehensive study on PBTTT-C14 channel has been carried out by thorough optoelectronic characterization of the device. Also, the impact of illumination on the apparent threshold voltage shift from 11.83 V to 8.68 V has been explained on the basis of the mechanism of operation of the device under illumination.

Background: Antibiotic policy and appropriate antibiotic prophylaxis cannot be designed unless data is available about bacteria colonizing the bile associated with gall bladder disease. Authors aim was to assess the clinical profile and pattern of bacterial isolates from bile aspirates of cholecystectomy patients seeking care at a tertiary care teaching hospital.Methods: Patients who underwent cholecystectomy for various hepatobiliary ailments during year 2017-18 formed the study population. Bile aspirates were collected during cholecystectomy and sent to the microbiology laboratory. Ultrasonography, computed tomography and MRCP were done to confirm the gall bladder pathology before surgery.Results: Out of total eighty-six patients, bacterial growth was observed in 28 (32.56%) subjects. As per division of bile samples, maximum number of study participants (39.29%) having bactibilia were seen in Group II. Group with second highest number of patients showing bactibilia was Group III with 9 subjects (32.14%). Eight subjects (28.57%) exhibited bacterial growth in bile aspirates in Group I subjects. Three patients (10.71%) showed bile infected with multiple bacteria i.e. polymicrobial infection. The gram-negative preponderance was seen in all the three groups with Escherichia coli being most common in group I and II. Pseudomonas aeruginosa was isolated in majority of the patients in group II and III.Conclusions: It is advised that all patients undergoing cholecystectomy must have their bile aspirated during cholecystectomy and sent for microbiological examination and culture. It will help in choosing appropriate antibiotic to prevent infection.

Background: A good and an effective empirical treatment of SBP is not possible unless bacteriological spectrum and their antibiogram is clear. This becomes more important in country like India due to high antibiotic resistance. Authors aim was to assess the prevalence of SBP, clinical and microbiological profile of its variants, in patients with cirrhosis seeking care at a tertiary care teaching hospital.Methods: Patients of liver cirrhosis with ascites seeking care at study subject during January- December 2018 formed the study population. Diagnosis was based on clinical examination, biochemical investigation and ultrasonography. Diagnostic abdominal paracentesis was performed on subjects within 24 hours of admission. Ascitic fluid was aspirated. It was sent for microbiological examination.Results: Prevalence of SBP was 16.12%. Out of total ten subjects with Spontaneous Bacterial Peritonitis (SBP), six subjects were of Culture Negative Neutrocytic Ascites (CNNA). Thus most common (60%), variant of Spontaneous Bacterial Peritonitis (SBP) was Culture Negative Neutrocytic Ascites (CNNA). Prevalence of Mono-microbial Non-neutrocytic Bacterascites (MNBA) and Classic-Spontaneous Bacterial Peritonitis (C-SBP) was 20%. Two subjects found positive for MNBA, Staphylococcus aureus and Acinitobacter spp. was detected in each patient. Klebseila pneumonia, Escherichia coli and Coagulase negative Staphylococcus were found in ascitic fluid culture of C-SBP. In clinical variants of SBP, 80% subject’s complaint about abdominal pain. Hepatic-encephalopathy and fever was seen in 7(70%) patients. Rebound tenderness was seen among 60%.Conclusions: Diagnostic paracentesis should be advised to all cirrhotic patients with ascites. Ascitic fluid analysis should be sent for better selection of antibiotics thus better outcome of cirrhotic patients.

Background: It is common for patients with type 2 diabetes mellitus (T2DM) to have vitamin D deficiency. Aim of the study is to determine the metabolic effects of oral vitamin D supplementation in a cohort of T2DM subjects.Methods: Subjects with T2DM were divided into two groups. Group A (Control) included subjects who received the standard treatment (conventional antidiabetic drugs). Group B (Intervention), apart from the standard treatment (conventional antidiabetic drugs), was also supplemented with Vitamin D3. All the patients were followed up at baseline, 6 months, 12 months and 18 months.Results: Vitamin D deficiency was noted down in all the study subjects. Even after 18 months of supplementation, all subjects remained vitamin D deficient. There was a significant improvement in the circulating levels of 25-hydroxyvitamin D. Improvement in the lipid profile of subjects was observed as evidenced by a decrease in total cholesterol (5.0±0.92 mmol/l) as compared to baseline (5.5±1.6 mmol/l). HOMA-IR changed significantly after 18 months of supplementation from baseline (7.0±1.06 vs 10.8±1.96 nmol/l).Conclusions: Supplementation to achieve higher levels of vitamin D remains a promising adjuvant therapy for T2DM patients. Additionally, the intervention brought out a favourable change in HDL/LDL ratio among study subjects.

Background Andaman and Nicobar Island is a group of 572 islands with a population of 3,80,500. The only service hospital as well as govt hospital is situated at its capital, Portblair. The islands are interconnected only by sea passage and to reach the capital by this route it sometimes takes two days. Methods The objective of this study is to assess the spectrum of different ocular diseases in remote islands of Andaman and Nicobar. Author had conducted various camps on these remote islands as a community outreach programme over two years. Results Top eye diseases found were refractive error (35%), cataract (22%), conjunctival infammatory disease (15%), glaucoma cases (07%), pterygium (07%), NLDO (02%) and uveitis (02%). Out of total 132 cataract patients screened, 32 patients (approximately 24%) were operated in INHS Dhanvantari at free of cost with help of NPCB (National Programme for Control of Blindness). Conclusion This was the first kind of study conducted on these remote islands to know the prevalence of different ocular diseases. The important point to be seen in this study was unawareness of glaucoma and cataract load. No optometrist was posted in the PHCs to provide primary eye care like prescribing glasses, which is also a big concern.

Background. The aim of the present paper was to study the expression and overexpression of EGFR in oral leukoplakia and cancer and at the same time assess the expression of EGFR in various histological grades of oral leukoplakia and OSCC in the Indian subcontinent. Methods. The study was conducted with routine H&E and IHC staining on 40 archival tissues. Results. Positive EGFR staining was present in all the cases 100% (30/30) out of which 7 (46.7%) cases of OSCC showed >75% EGFR expression and 8 (53.3%) cases of oral leukoplakia showed 25% EGFR expression. A statistically significant correlation was found in OSCC, OL and controls. Conclusions. EGFR may represent a promising target for novel molecular cancer therapies. EGFR expression levels in the premalignant lesion appear to be a sensitive factor in predicting the neoplastic potential of dysplastic tissues. This suggests that EGFR may serve as a biological marker to identify high-risk subgroups and guide prophylactic therapy.

A non-perturbation formalism underlying a quantum theory of gravity is revisited by exploiting a two form in a non-linear U ( 1 ) gauge theory on a D 4 -brane. In particular, we explore two different gauge choices for a two form underlying the dynamics of a higher dimensional geometric torsion in a second order formalism. We obtain two non-extremal quantum Kerr geometries in five dimensions on a pair of ( D D ¯ ) 4 -brane in a type IIA superstring theory. In the gauge choice, the quantum vacua may seen to underlie a non-propagating torsion on a non-BPS brane. It is argued that the quantum Kerr vacua undergo tunneling and lead to a five dimensional Einstein Kerr black hole in a low energy limit.

Silicene, a graphene analogue of silicon, has been generating immense interest due to its potential for applications in miniaturized devices. Unlike planar graphene, silicene prefers a buckled structure. Here we explore the possibility of stabilizing the planar form of silicene by Ni doping using first principles density functional theory based calculations. It is found that planar as well as buckled structure is stable for Ni-doped silicene, but the buckled sheet has slightly lower total energy. The planar silicene sheet has unstable phonon modes. A comparative study of the mechanical properties reveals that the in-plane stiffness of both the pristine and the doped planar silicene is higher compared to that of the buckled silicene. This suggests that planar silicene is mechanically more robust. Electronic structure calculations of the planar and buckled Ni-doped silicene show that the energy bands at the Dirac point transform from linear behavior to parabolic dispersion. Furthermore, we extend our study to Ge and Sn sheets that are also stable and the trends of comparable mechanical stability of the planar and buckled phases remain the same.

Stone–Wales (SW) defects in materials having hexagonal lattice are the most common topological defects that affect the electronic and mechanical properties. Using first principles density functional theory based calculations, we study the formation energy and kinetic barrier of SW-defect in infinite and finite sheets of silicene. The formation energies as well as the barriers in both the cases are significantly lower than those of graphene. Furthermore, compared with the infinite sheets, the energy barriers and formation energies are lower for finite sheets. However, due to low barriers these defects are expected to heal out of the finite sheets.

Using first principles density functional theory, we report for CrSi2, a linear relationship between thermodynamic charge state transition levels of defects and maxima of thermopower Tm, thus proposing a unique way of tuning thermoelectric properties. We show for doped CrSi2 that the peak of thermopower occurs at the temperature which corresponds to the position of the defect transition level. Therefore, by modifying the defect transition level, a thermoelectric material with a given operational temperature can be designed.

A complete finite element analysis on the effect of the Darcy number for heat-flow visualization (via heatlines) and entropy generation due to heat transfer (S?) and fluid friction (S?) within inclined porous cavities is presented. Heatlines are obtained via solution of the Poisson equation using the finite element method. Strong features on conductive and convective heat fluxes were found for high Darcy number flows. Generalized formulations on finite element basis functions are used to calculate all derivatives (S? and S?) for entropy generation within tilted cavities for all tilted angles (?). On the basis of the entropy generation minimization approach, it has been concluded that the cavities with inclination angles ? ? 30 for lower Pr fluid (Pr = 0.025) and ? = 15 for higher Pr (Pr = 998) may be an efficient strategy for optimal thermal processing. � 2013 American Chemical Society.

Bisphosphonates (BPs), in the past erroneously referred to as diphosphonates, were first synthesized in Germany, in 1865. BPs are stable analogs of pyrophosphate that are naturally occurring modulators of bone metabolism and have been synthesized and used since the 19th century; However, their in-vitro ability to inhibit the precipitation of calcium phosphate was applied clinically in the 1960s. Since then, the main clinical application was in the treatment of certain resorptive bone diseases (osteoporosis, Paget’s disease, and hypercalcemia associated with certain malignancies such as multiple myeloma and bone metastasis from the breast or prostate). Later on, in 2002, the Food and Drug Administration reviewed some cases of osteonecrosis of the jaw in cancer patients who had undergone BP therapy. In 2003, Marx introduced this clinical condition in the medical literature. BP-induced osteonecrosis of the jaw is related to the development of avascular necrosis or dead jaw bones and cannot easily be treated with conventional medical and/or surgical intervention. Because of the poor treatment outcomes, many studies focused on its preventive measures. In this study, we review the different risk factors and associated preventive measures against BRONJ. Egypt J Oral Maxillofac Surg 4:23–26 c 2013 The Egyptian Association of Oral & Maxillofacial Surgeons.

While ${\mathrm{SnS}}_{2}$ is an earth-abundant large-band-gap semiconductor material, the indirect nature of the band gap limits its applications in light harvesting or detection devices. Here, using density functional theory in combination with the many-body perturbation theory, we report indirect-to-direct band-gap transition in bulk ${\mathrm{SnS}}_{2}$ under moderate, $2.98%$ uniform biaxial tensile (BT) strain. Further enhancement of the BT strain up to $9.75%$ leads to a semiconductor-to-metal transition. The strain-induced weakening of the interaction of the in-plane orbitals modifies the dispersion as well as the character of the valence- and the conduction-band edges, leading to the transition. A quasiparticle direct band gap of 2.17 eV at the $\mathrm{\ensuremath{\Gamma}}$ point is obtained at $2.98%$ BT strain. By solving the Bethe-Salpeter equation to include excitonic effects on top of the partially self-consistent ${\mathrm{GW}}_{0}$ calculation, we study the dielectric functions, optical oscillator strength, and exciton binding energy as a function of the applied strain. At $2.98%$ BT strain, our calculations show the relatively high exciton binding energy of 170 meV, implying strongly coupled excitons in ${\mathrm{SnS}}_{2}$. The effect of strain on vibrational properties, including Raman spectra, is also investigated. The Raman shift of both in-plane (${E}_{2g}^{1}$) and out-of plane (${A}_{1g}$) modes decreases with the applied BT strain, which can be probed experimentally. Furthermore, ${\mathrm{SnS}}_{2}$ remains dynamically stable up to $9.75%$ BT strain, at which it becomes metallic. A strong coupling between the applied strain and the electronic and optical properties of ${\mathrm{SnS}}_{2}$ can significantly broaden the applications of this material in strain-detection and optoelectronic devices.

Herein, an optimized method for 100 g scale synthesis of glycerol oligomers using a microwave multimode source and the low priced K2CO3 as catalyst is reported. This method allows the complete conversion of glycerol to its oligomers in only 30 min, yielding molecular weights up to 1000 g mol−1. Furthermore, a simple iterative purification process, involving the precipitation of the crude product in acetone and methanol, affords a final product composed of larger oligomers with a narrow dispersity (D < 1.5).

Using first-principles calculations, we report a large band-gap opening in the van der Waals heterostructure of graphene and graphane (hydrogenated graphene) under normal compressive (NC) strain. In the presence of graphane, interlayer charge transfer from graphene to graphane triggers the intralayer charge redistribution in graphene, breaking the equivalence of the two sublattices. This chiral symmetry breaking, however, is not strong enough to split the Dirac cone. The application of the NC strain enhances the inter- and intralayer charge transfer leading to a splitting of the Dirac cone, reflected as a redshift of the $G$ peak in Raman spectra. With strain, the band gap increases monotonically and attains a maximum of 0.74 eV at 20% strain, which is the largest ever reported splitting of a Dirac cone in graphene. Tight-binding analysis demonstrates that the applied strain changes the on-site interactions of carbon atoms belonging to a particular sublattice of graphene, thereby breaking the chiral symmetry leading to the opening of a band gap. A sufficiently large band gap with linear dispersion of Dirac bands in the graphene/graphane heterostructure constitutes promising features for room-temperature electronic and optical devices.

MXene, a two-dimensional layer of transition metal carbides/nitrides, showed great promise for energy storage, sensing, and electronic applications. MXene are chemically exfoliated from the bulk MAX phase; however, mechanistic understanding of exfoliation and subsequent functionalization of these technologically important materials is still lacking. Here, using density-functional theory we show that exfoliation of Ti3C2 MXene proceeds via HF insertion through edges of Ti3AlC2 MAX phase. Spontaneous dissociation of HF and subsequent termination of edge Ti atoms by H/F weakens Al-MXene bonds. Consequent opening of the interlayer gap allows further insertion of HF that leads to the formation of AlF3 and H2, which eventually come out of the MAX, leaving fluorinated MXene behind. Density of state and electron localization function shows robust binding between F/OH and Ti, which makes it very difficult to obtain controlled functionalized or pristine MXene. Analysis of the calculated Gibbs free energy (ΔG) shows fully fluorinated MXene to be lowest in energy, whereas the formation of pristine MXene is thermodynamically least favorable. In the presence of water, mixed functionalized Ti3C2Fx(OH)1-x (x ranges from 0 to 1) MXene can be obtained. The ΔG values for the mixed functionalized MXenes are very close in energy, indicating the random and nonuniform functionalization of MXene. The microscopic understanding gained here unveils the challenges in exfoliation and controlling the functionalization of MXene, which is essential for its practical application.

A cleaner and greener method has been developed and used to synthesize 14 different functionalized oligomer derivatives of glycerol in moderate 29%–39% yields over three steps. After successive regioselective enzymatic acylation of the primary hydroxyl groups, etherification or esterification of the secondary hydroxyl groups and chemoselective enzymatic saponification, the target compounds can efficiently be used as versatile building blocks in organic and supramolecular chemistry.

This study is all about the significant issue of CSR and its link with the PR in the present era of LPG (Liberalization, Privatization and Globalization). Effective CSR is very important for building brand image of the organization to maximize customers trust by promoting the social responsibility as a corporate duty of the corporate sector for human welfare and social development by enhancing the knowledge of audience, their interests and expectations, and ethical practices for communicating information. This paper attempted to review various companies in Indian corporate society and measure the value of public relations functions for the social awareness by effective communication. The purpose of this review is to constructively analyze the effectiveness of MNC’s CSR and Public Relations through various recent examples. The methodology adopted in this study is secondary.

While pressure-induced changes in the electronic, magnetic, and optical properties of Cu-Cl hybrid perovskites have been studied intensively, the correlation between these properties and pressure-induced structural changes is still vaguely understood. Here, by first-principles calculations on a model system (EDBE)[CuCl4] (EDBE = 2,2'-(ethylenedioxy)bis(ethylammonium)) (a Cu-Cl hybrid perovskite), we correlate the evolution of a series of exciting physical properties with pressure while resolving some of the long-standing debates on the fundamental electronic nature of this important class of material. The material shows two structural phase transitions and an anisotropy in compressibility with increasing pressure. After a critical pressure of 17 GPa, the structure becomes highly symmetric, thereby suppressing the Jahn-Teller distortions. At zero pressure, mapping the optical transitions with the Laporte selection rules, lower and higher energy excitations are found to be of Mott-Hubbard (MH) and charge transfer (CT) type, respectively, signifying the material to be a Mott insulator. The material shows a red shift in the charge transfer band edge with increasing pressure and temperature, demonstrating the piezochromism and the thermochromism, respectively. Piezochromism originates from the changes in mixing of Cl-Cu p-d states, while thermochromism is due to broadening of conduction band states, thereby showing different electronic and structural evolution with pressure and temperature. Furthermore, the magnetic ordering in the material was found to be stable up to higher pressures, making pressure a tool to tune the electronic property without perturbing the magnetic property.