Isolation, purification, characterization and applications of serine protease from Bacillus megaterium

Bacillus megaterium isolated from poultry farm soil was identified by standard biochemical tests and screened for the production of serine protease. Production of serine protease was done using 5 different medias by varying the type of amino acid added. The purification was done by salt precipitation, dialysis and DEAEcellulose ion exchange chromatography. The proline containing media obtained the highest fold purification out of the five different medias (leucine, lysine, proline, tryptophan and methionine cotaining media). The enzyme showedan optimal activity at the temperature 37°C and the pH 6 which are known as its optimum temperature and pH respectively. The enzyme was proved as a Mn2+ dependent serine protease as it was activated by Mn2+ ions and inhibited by PMSF. The molecular weight of the enzyme was determined by SDS-PAGE technique as around 30kDa. It showed an excellent detergent activity on the blood stains and a very good stability in presence of locally available detrgents. The enzyme acted on the keratin protein of the chicken feather and showed a degrading capacity on the protein. So it was proved that the recently studied serine protease has a keratinase activity also. From these datas I conclude that the protease isolated from Bacillus megaterium is a Mn2+ dependent serine protease which has both keratinase and detergent activity

Assessment of Physicochemical parameters and Water Quality Index of Vishwamitri River, Gujarat, India

Development and industrialisation exert pressure on the riverine system deteriorating the serenity of the rivers. The present study was carried out in Small River flowing through Vadodara city viz., Vishwamitri River. The study revealed better water quality before its entry into the urban area. Despite of presence of STPs, there is poor water quality affecting the aquatic life and ecology. The paper throws light on pollution aspect and need to develop decentralised treatment system to tackle the river pollution problem

In situ carbon coated Li2MnSiO4/C composites as cathodes for enhanced performance li-ion batteries

An in-situ carbon coated Li2MnSiO4/C composite was synthesized by a nanocomposite gel precursor route using starch as the carbon source. Our approach enabled a uniform coating of amorphous carbon on Li 2MnSiO4 with an orthorhombic crystalline structure, which was confirmed by electron microscopy, X-ray diffraction and Raman studies. Conducting-atomic force microscopy (C-AFM) images also revealed the presence of high current interconnected domains in the composite, indicating the ability of the carbon coating to facilitate electron movement. Galvanostatic charge-discharge studies demonstrated outstanding initial charge and discharge capacities, respectively, of 330 and 195 mAh g-1 at 0.05 C-rate for the composite, and after 30 cycles a reversible capacity of 115 mAh g -1 was retained. The electrochemical performance of the neat silicate was dismal (10.6 mAh g-1 at 0.05 C-rate), which again reiterated the role of carbon in improving the conduction and Li-ion storage capacity of the silicate. An insignificant change in charge transfer resistance, with cycling, as inferred from impedance spectroscopy illustrated that charge transfer and transport processes remain facile with cycling, thus demonstrating Li 2MnSiO4/C to be promising cathode Li-ion batteries

Mott Transition of MnO under Pressure: Comparison of Correlated Band Theories

The electronic structure, magnetic moment, and volume collapse of MnO under pressure are obtained from four different correlated band theory methods; local density approximation + Hubbard U (LDA+U), pseudopotential self-interaction correction (pseudo-SIC), the hybrid functional (combined local exchange plus Hartree-Fock exchange), and the local spin density SIC (SIC-LSD) method. Each method treats correlation among the five Mn 3d orbitals (per spin), including their hybridization with three O $2p$ orbitals in the valence bands and their changes with pressure. The focus is on comparison of the methods for rocksalt MnO (neglecting the observed transition to the NiAs structure in the 90-100 GPa range). Each method predicts a first-order volume collapse, but with variation in the predicted volume and critical pressure. Accompanying the volume collapse is a moment collapse, which for all methods is from high-spin to low-spin (5/2 to 1/2), not to nonmagnetic as the simplest scenario would have. The specific manner in which the transition occurs varies considerably among the methods: pseudo-SIC and SIC-LSD give insulator-to-metal, while LDA+U gives insulator-to-insulator and the hybrid method gives an insulator-to-semimetal transition. Projected densities of states above and below the transition are presented for each of the methods and used to analyze the character of each transition. In some cases the rhombohedral symmetry of the antiferromagnetically ordered phase clearly influences the character of the transition.Comment: 14 pages, 9 figures. A 7 institute collaboration, Updated versio

Superconductivity and Lattice Instability in Compressed Lithium from Fermi Surface Hot Spots

The highest superconducting temperature T$_c$ observed in any elemental metal (Li with T$_c$ ~ 20 K at pressure P ~ 40 GPa) is shown to arise from critical (formally divergent) electron-phonon coupling to the transverse T$_1$ phonon branch along intersections of Kohn anomaly surfaces with the Fermi surface. First principles linear response calculations of the phonon spectrum and spectral function $\alpha^2 F(\omega)$ reveal (harmonic) instability already at 25 GPa. Our results imply that the fcc phase is anharmonically stabilized in the 25-38 GPa range.Comment: 4 pages, 3 embedded figure

Simulations of an OSNR-limited all-optical wavelength conversion scheme

We present simulations of a scheme to perform wavelength conversion of signals that eliminates phase-noise transfer from the pump to the converted signal. Nondegenerate four-wave mixing in a semiconductor optical amplifier is used to convert the signal to a new wavelength; and if an optical comb generator is used as the multiple-pump source, then the signal can be converted without incurring any phase-noise transfer from the pumps. We highlight the capabilities of this scheme by simulating the conversion of 16-QAM signals at 10 Gbaud and showing that errors due to phase-noise accumulation are eliminated thus enabling conversion whose only impairment would be the total additive optical noise

U.S. adolescent and adult women\u27s experiences accessing and using toilets in schools, workplaces, and public spaces: A multi-site focus group study to inform future research in bladder health

The World Health Organization recognizes access to clean and safe toilets as crucial for public health. This study explored U.S. adolescent and adult cisgender women\u27s lived experiences accessing toilets in schools, workplaces, and public spaces. As part of the Prevention of Lower Urinary Tract Symptoms (PLUS) Research Consortium, we conducted 44 focus groups with female participants (n = 360; ages 11-93). Focus groups were stratified by age (11-14, 15-17, 18-25, 26-44, 45-64, 65+) and conducted across 7 geographically diverse U.S. sites from July 2017-April 2018. Using a transdisciplinary approach, we conducted conventional qualitative coding informed by our PLUS conceptual framework and used content analysis processes to identify salient themes. Across settings, toilet access was restricted by gatekeepers (i.e., individuals who control access to toilets). In contrast, self-restricting toilet use (deciding not to use the toilet despite biologic need to urinate) was based on internalized norms to prioritize school and job responsibilities over urination. In public spaces, self-restricting use was largely in response to lack of cleanliness. Across the life course, participants perceived gender disparities in the ability to easily access public toilets. Further research is needed to determine if and how these factors impact bladder health across the life course

Spironolactone for People Age 70 Years and Older With Osteoarthritic Knee Pain:A Proof‐of‐Concept Trial

Objective: To determine whether spironolactone could benefit older people with osteoarthritis (OA), based on a previous study showing that spironolactone improved quality of life. Methods: This parallel-group, randomized, placebo-controlled, double-blind trial randomized community-dwelling people ages ≥70 years with symptomatic knee OA to 12 weeks of 25 mg daily oral spironolactone or matching placebo. The primary outcome was between-group difference in change in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale scores. Secondary outcomes included WOMAC stiffness and physical function subscores, EuroQol 5-domain (EQ-5D) 3L score, and mechanistic markers. Analysis was by intent to treat, using mixed-model regression, adjusting for baseline values of test variables. Results: A total of 421 people had eligibility assessed, and 86 were randomized. Mean ± SD age was 77 ± 5 years and 53 of 86 (62%) were women. Adherence to study medication was 99%, and all participants completed the 12-week assessment. No significant improvement was seen in the WOMAC pain score (adjusted treatment effect 0.5 points [95% confidence interval (95% CI) - 0.3, 1.3]; P = 0.19). No improvement was seen in WOMAC stiffness score (0.2 points [95% CI -0.6, 1.1]; P = 0.58), WOMAC physical function score (0.0 points [95% CI -0.7, 0.8]; P = 0.98), or EQ-5D 3L score (0.04 points [95% CI -0.04, 0.12]; P = 0.34). Cortisol, matrix metalloproteinase 3, and urinary C-telopeptide of type II collagen were not significantly different between groups. More minor adverse events were noted in the spironolactone group (47 versus 32), but no increase in death or hospitalization was evident. Conclusion: Spironolactone did not improve symptoms, physical function, or health-related quality of life in older people with knee OA

Following Natures Lead: On the Construction of Membrane-Inserted Toxins in Lipid Bilayer Nanodiscs

Bacterial toxin or viral entry into the cell often requires cell surface binding and endocytosis. The endosomal acidification induces a limited unfolding/refolding and membrane insertion reaction of the soluble toxins or viral proteins into their translocation competent or membrane inserted states. At the molecular level, the specific orientation and immobilization of the pre-transitioned toxin on the cell surface is often an important prerequisite prior to cell entry. We propose that structures of some toxin membrane insertion complexes may be observed through procedures where one rationally immobilizes the soluble toxin so that potential unfolding ↔ refolding transitions that occur prior to membrane insertion orientate away from the immobilization surface in the presence of lipid micelle pre-nanodisc structures. As a specific example, the immobilized prepore form of the anthrax toxin pore translocon or protective antigen can be transitioned, inserted into a model lipid membrane (nanodiscs), and released from the immobilized support in its membrane solubilized form. This particular strategy, although unconventional, is a useful procedure for generating pure membrane-inserted toxins in nanodiscs for electron microscopy structural analysis. In addition, generating a similar immobilized platform on label-free biosensor surfaces allows one to observe the kinetics of these acid-induced membrane insertion transitions. These platforms can facilitate the rational design of inhibitors that specifically target the toxin membrane insertion transitions that occur during endosomal acidification. This approach may lead to a new class of direct anti-toxin inhibitors