Implications of Unitarity and Charge Breaking Minima in Left-Right Symmetric Model

We examine the usefulness of the unitarity conditions in Left-Right symmetric model which can translate into giving a stronger constraint on the model parameters together with the criteria derived from vacuum stability and perturbativity. In this light, we demonstrate the bounds on the masses of the physical scalars present in the model and find the scenario where multiple scalar modes are in the reach of Large Hadron Collider. We also analyse the additional conditions that can come from charge breaking minima in this context.Comment: v2: Accepted for publication in Phys. Rev. D, reference added, minor change in the text, 16 pages, 2 figure

Genetic Signatures in the Envelope Glycoproteins of HIV-1 that Associate with Broadly Neutralizing Antibodies

A steady increase in knowledge of the molecular and antigenic structure of the gp120 and gp41 HIV-1 envelope glycoproteins (Env) is yielding important new insights for vaccine design, but it has been difficult to translate this information to an immunogen that elicits broadly neutralizing antibodies. To help bridge this gap, we used phylogenetically corrected statistical methods to identify amino acid signature patterns in Envs derived from people who have made potently neutralizing antibodies, with the hypothesis that these Envs may share common features that would be useful for incorporation in a vaccine immunogen. Before attempting this, essentially as a control, we explored the utility of our computational methods for defining signatures of complex neutralization phenotypes by analyzing Env sequences from 251 clonal viruses that were differentially sensitive to neutralization by the well-characterized gp120-specific monoclonal antibody, b12. We identified ten b12-neutralization signatures, including seven either in the b12-binding surface of gp120 or in the V2 region of gp120 that have been previously shown to impact b12 sensitivity. A simple algorithm based on the b12 signature pattern was predictive of b12 sensitivity/resistance in an additional blinded panel of 57 viruses. Upon obtaining these reassuring outcomes, we went on to apply these same computational methods to define signature patterns in Env from HIV-1 infected individuals who had potent, broadly neutralizing responses. We analyzed a checkerboard-style neutralization dataset with sera from 69 HIV-1-infected individuals tested against a panel of 25 different Envs. Distinct clusters of sera with high and low neutralization potencies were identified. Six signature positions in Env sequences obtained from the 69 samples were found to be strongly associated with either the high or low potency responses. Five sites were in the CD4-induced coreceptor binding site of gp120, suggesting an important role for this region in the elicitation of broadly neutralizing antibody responses against HIV-1

ACE Inhibitory Peptides from Bellamya bengalensis Protein Hydrolysates: In Vitro and In Silico Molecular Assessment

Bellamya bengalensis muscle meat is known for ethnopharmacological benefits. The present study focuses on the identification of ACE inhibitory peptides from the proteolytic digests of muscle protein of Bellamya bengalensis and its underlying mechanism. After ultrafiltration of 120 min alcalase hydrolysates (BBPHA120) to isolate the small peptide fraction (<3 kDa), in vitro ACE inhibitory activity was analyzed. The IC50 value of the 120 min hydrolysate ultrafiltered fraction was 86.74 ± 0.575 µg/mL, while the IC50 of lisinopril was 0.31 ± 0.07 µg/mL. This fraction was assessed in a MALDI-ToF mass spectrometer and five peptides were identified from the mass spectrum based on their intensity (>1 × 104 A.U.). These peptides were sequenced via de novo sequencing. Based on the apparent hydrophobicity (%), the IIAPTPVPAAH peptide was selected for further analysis. The sequence was commercially synthesized by solid-phase standard Fmoc chemistry (purity 95–99.9%; by HPLC). The synthetic peptide (IC50 value 8.52 ± 0.779 µg/mL) was used to understand the thermodynamics of the inhibition by checking the binding affinity of the peptide to ACE by isothermal titration calorimetry compared with lisinopril, and the results were further substantiated by in silico site-specific molecular docking analysis. The results demonstrate that this peptide sequence (IIAPTPVPAAH) can be used as a nutraceutical with potent ACE inhibition

Probing the compound effect of spatially varying intrinsic defects and doping on mechanical properties of hybrid graphene monolayers

Doping in pristine 2D materials brings about the advantage of modulating wide range of mechanical properties simultaneously. However, intrinsic defects (such as Stone-Wales and nanopore) in such hybrid materials are inevitable due to complex manufacturing and synthesis processes. Besides that, defects and irregularities can be intentionally induced in a pristine nanostructure for multi-synchronous modulation of various multi-functional properties. Whatever the case may be, in order to realistically analyse a doped graphene sheet, it is of utmost importance to investigate the compound effect of doping and defects in such 2D monolayers. Here we present a molecular dynamics based investigation for probing mechanical properties (such as Young's modulus, post-elastic behaviour, failure strength and strain) of doped graphene (C14 and Si) coupling the effect of inevitable defects. Spatial sensitivity of defect and doping are systematically analyzed considering different rational instances. The study reveals the effects of individual defects and doping along with their possible compounded influences on the failure stress, failure strain, Young's modulus and constitutive relations beyond the elastic regime. Such detailed mechanical characterization under the practically relevant compound effects would allow us to access the viability of adopting doped graphene in various multifunctional nanoelectromechanical devices and systems in a realistic situation.</p

Efficient lightweight design of FRP bridge deck

An efficient yet simple response surface-based technique is proposed for the design of lightweight fibre-reinforced plastic (FRP) composite bridge deck panels. To achieve a lightweight FRP bridge deck, the total volume of the structure was optimised under the constraint of deflection limit, stresses, buckling and different failure criteria. Central composite design was employed in conjunction with a constrained multivariable non-linear optimisation algorithm to minimise the weight of the FRP bridge deck. Top/bottom plate thickness, web thickness, overall depth and number of webs were considered as design variables. The results obtained for different bridge deck configurations using the proposed response surface-based optimisation technique were validated with the results of conventional optimisation methods. Sensitivity analysis was also carried out to study the influence of different design variables towards deflection, stress and buckling behaviour of the bridge deck.</p

Nonlinear stability of curved multi-phase composite panels: influence of agglomeration in randomly distributed carbon nanotubes with non-uniform in-plane loads

The nonlinear stability characteristics of doubly curved panels made of three-phase composites with randomly dispersed carbon nanotubes (RD-CNTRFC) subjected to practically-relevant non-uniform in-plane loads are investigated in this study. Carbon nanotubes, when mixed with resin polymer, may give rise to bundles, termed as agglomerations, which can have a profound impact on the effective material properties. There exists a strong rationale to investigate the influence of such agglomeration on the nonlinear equilibrium path of panels, which can subsequently be included in the structural stability design process to enhance operational safety. A multi-stage bottom-up numerical framework is developed here to probe the nonlinear stability characteristics. The effective material properties of RD-CNTRFC panels are determined using the Eshelby-Mori-Tanaka approach and the Chamis method of homogenization. By considering von-Kármán non-linearity and Reddy's higher-order shear deformation theory, strain-displacement relations are established for the non-linear stability analysis. The governing partial differential equations are simplified into nonlinear algebraic relations using Galerkin's method. Subsequently, by reducing the stiffness matrix neglecting the non-linear terms and solving the Eigenvalue problem, we obtain critical load and non-linear stability path of shell panels based on arc-length approach. In the present study, various shell geometries such as cylindrical, elliptical, spherical and hyperbolic shapes are modeled along with the flat plate-like geometry to investigate the non-linear equilibrium paths, wherein a geometry-dependent programmable softening and hardening behavior emerges

Poly(thieno[3,4-b]furan), a New Low Band Gap Polymer: Experiment and Theory

A new optically transparent, near-infrared-absorbing low energy gap conjugated polymer, poly (thieno[3,4-b]furan) (PT34bF), with promising attributes for photovoltaics is reported herein. PT34bF was prepared electrochemically, and upon redox cycling, doping was found to be anion dominant. The energy gap of the polymer was found to be 1.04 eV as calculated from the low-energy edge of the absorption spectrum of the neutral polymer at -0.6 V and 1.03 eV for the chemically neutralized polymer using hydrazine. The polymer is pale blue in the neutral form and a more transparent pale blue in the oxidized conducting state with photopic transmittances of 62% and 72% (ITO glass substrate not subtracted), indicating the possibility of application as a transparent conductor or an ion-storage layer for electronic devices. Density functional theory (DFT) calculations using B3PW91 hybrid functional have been carried out for possible connections between the three open alpha-positions. In addition to optimizing geometry, band structure properties such as band (energy) gaps, band widths, and effective masses were calculated for each connection. Calculations show that 4-6 connectivity is the most probable and dominant structure for the polymer resulting from T34bF, and the calculated energy gap of 1.01 eV for polymerization via this connection corresponds well with the experimentally observed value of 1.04 eV