Metal ion sensing and light activated antimicrobial activity of aloe-vera derived carbon dots

Carbon dots (CDs) have emerged out as a potential material amongst the carbon family for a wide range of applications including chemical/biological sensing, photocatalysis, bioimaging, etc. The green synthesis of these CDs from natural sources is gaining the significant interest of peer community for their wide utility. Herein, we present a facile one-step pyrolysis method for CDs synthesis from Aloe-Vera extract, which show bright blue luminescence under UV light with a quantum yield of 12.3%. Further, ex-situ morphological, structural and optical characterizations reveal their high quality and excitation independent emission behavior with the presence of carboxyl, hydroxyl functional groups. Furthermore, these CDs were studied for Fe(III) sensing in water without any surface modifications and assessed for their light activated antibacterial activity against E.Coli and Staphylococcus aureus.     

Capsaicin pretreatment enhanced the bioavailability of fexofenadine in rats by P-glycoprotein modulation: in vitro,in situ and in vivo evaluation

Background and objective: Capsaicin is the main pungent principle present in chili peppers has been found to possess P-glycoprotein (P-gp) inhibition activity in vitro, which may have the potential to modulate bioavailability of P-gp substrates. Therefore, purpose of this study was to evaluate the effect of capsaicin on intestinal absorption and bioavailability of fexofenadine, a P-gp substrate in rats.

Methods: The mechanistic evaluation was determined by non-everted sac and intestinal perfusion studies to explore the intestinal absorption of fexofenadine. These results were confirmed by an in vivo pharmacokinetic study of oral administered fexofenadine in rats.

Results: The intestinal transport and apparent permeability (P_app) of fexofenadine were increased significantly by 2.8 and 2.6 fold, respectively, in ileum of capsaicin treated rats when compared to control group. Similarly, absorption rate constant (K_a), fraction absorbed (F_ab) and effective permeability (P_eff) of fexofenadine were increased significantly by 2.8, 2.9 and 3.4 fold, respectively, in ileum of rats pretreated with capsaicin when compared to control group. In addition, maximum plasma concentration (C_max) and area under the concentration-time curve (AUC) were increased significantly by 2.3 and 2.4 fold, respectively, in rats pretreated with capsaicin as compared to control group. Furthermore, obtained results in rats pretreated with capsaicin were comparable to verapamil (positive control) treated rats.

Conclusions: Capsaicin pretreatment significantly enhanced the intestinal absorption and bioavailability of fexofenadine in rats likely by inhibition of P-gp mediated cellular efflux, suggesting that the combined use of capsaicin with P-gp substrates may require close monitoring for potential drug interactions.     

Need of Alcohol Reference Materials and Reliable Measurement of Alcohol Content by Breath Alcohol Analyzer in India: An Overview

Breath alcohol analyser is used to detect alcohol content in end-expiratory breaths in order to enforce driving regulations under the influence of alcohol legislation. The accuracy and reliability of the routine measurements of alcohol content performed with breath alcohol analyser can be achieved by the calibration of the breath alcohol analyser using standards traceable to SI reference material. Proper calibration is essential for transparency in legal verification for which reference material is needed. At international level, a number of NMIs are active to address this important measurement issue of providing accurate measurements. Several international key comparison programs have been organized so far for the determination of ethanol content in aqueous and in nitrogen/air matrix. NIST, USA; BAM, Germany; IRMM, Belgium, Portugal, INMETRO, Brazil, LGC, UK etc. have developed certain reference materials of ethanol in water solution/air with different concentration ranges. However, no such reference material is introduced in India as an indigenous standard, rather, being procured from abroad or using high purity alcohol for calibration purposes. CSIR-NPL, India, being the NMI is now focusing on establishing the calibration facility and development of SI traceable aqueous alcohol standard to provide test reliability for the testing in breath alcohol analyser. This program has a societal impact which contributes to human health and regulatory needs for the nation.     

An efficient 146-line 3D sensitivity analysis code of stress-based topology optimization written in MATLAB

Optimization and Engineering - This paper presents an efficient and compact MATLAB code for three-dimensional stress-based sensitivity analysis. The 146 lines code includes the finite element...     

Creep behavior of nuclear grade 316LN austenitic stainless steel at 873 K and 923 K

Mechanics of Time-Dependent Materials - Creep deformation and rupture behavior of nitrogen-alloyed (0.14 wt.%) nuclear grade 316LN austenitic stainless steel were investigated for the varying...     

Uniplanar Y and L shaped ACS fed multiband and wideband compact printed antenna for advanced wireless communication systems

Microsystem Technologies - In this paper, a very small size (14 × 20 mm2), tunable printed antenna consisting of Asymmetric Coplanar Strip (ACS) feedline with three...     

Modelling of Chevron electrothermal actuator and its performance analysis

Microsystem Technologies - In this work, a Chevron electrothermal actuator is designed and its analytical model is developed. Chevron actuator works on the principle of Joules heating effect and...     

An IND-CCA2 Secure Certificateless Hybrid Signcryption

This article proposes a hybrid certificateless signcryption scheme that is secure against adaptive chosen ciphertext adversary in the random oracle model. The scheme combines an asymmetric encryption which is one way against chosen plaintext attack and any One-Time secure symmetric encryption scheme, combined using Fujisaki–Okamoto transformation. Uncommon to many Fujisaki–Okamoto based constructions which ensure message integrity alone, this scheme provides entity authentication in addition. By the choice of a hash function that utilizes the advantage of sponge based construction, the scheme enables the user to incorporate any One-Time secure symmetric encryption by re-configuring the input/output parameters. Fujisaki–Okamoto transformation, which is currently a standard in hybrid constructions, guarantees the indistinguishability against adaptive chosen ciphertext attack. The provision for choosing symmetric encryption in the scheme enables it to be implemented in all sort of cryptographic requirements including those in wireless communication.

     

Well-Balanced Nodal Discontinuous Galerkin Method for Euler Equations with Gravity

We present a well-balanced nodal discontinuous Galerkin (DG) scheme for compressible Euler equations with gravity. The DG scheme makes use of discontinuous Lagrange basis functions supported at Gauss–Lobatto–Legendre (GLL) nodes together with GLL quadrature using the same nodes. The well-balanced property is achieved by a specific form of source term discretization that depends on the nature of the hydrostatic solution, together with the GLL nodes for quadrature of the source term. The scheme is able to preserve isothermal and polytropic stationary solutions upto machine precision on any mesh composed of quadrilateral cells and for any gravitational potential. It is applied on several examples to demonstrate its well-balanced property and the improved resolution of small perturbations around the stationary solution.