Enhanced Photocatalytic and Antibacterial Activities of ZnSe Nanoparticles

Water and microbial contamination is a serious issues to aquatic system and human health. The metal selenide has a tremendous technique to degrade the dyes and bacteria.The present work reports the synthesis of ZnSe nanoparticles in a simple co-precipitation method. The synthesized samples were analyzed by structural, optical, morphological, catalytic and biological activity. The size and bandgap by annealing temperature tuning which are confirm by X-ray Diffraction and UV–Visible spectrometer. The quasi-spherical shapes were confirmed by Scanning Electron Microscope and Transmission Electron Microscope.The photo excited electrons have trapped the metals and promoting the degradation system. The release of ions to the surface was acknowledged by Photo Luminescence spectroscopy. The photocatalytic dye degradation of the Methyl Orange showed that the enhanced activity in high temperature. The photocatalytic dye degradation activity suggested that the temperature change the production of free radicals and ROS formation. The hydroxyl radicals were slewing the dye molecules and bacteria. The obtained results giving the information of ZnSe nanoparticles are one of the fascinating research areas in the current research world. Because of its large application in different field it acts as a promoting catalytic and biological application.

Graphical Abstract

     

Computing median and antimedian sets in median graphs

The median (antimedian) set of a profile π=(u ₁,…,u _k ) of vertices of a graph G is the set of vertices x that minimize (maximize) the remoteness ∑ _i d(x,u _i ). Two algorithms for median graphs G of complexity O(n idim(G)) are designed, where n is the order and idim(G) the isometric dimension of G. The first algorithm computes median sets of profiles and will be in practice often faster than the other algorithm which in addition computes antimedian sets and remoteness functions and works in all partial cubes.     

High‐performance electromagnetic interference shielding material based on an effective mixing protocol

A facile and economic method is developed for the fabrication of new lightweight materials with high electromagnetic interference (EMI) shielding performance, good mechanical properties and low electrical percolation threshold through melt mixing. Electrical properties, DC conductivity, EMI shielding performance and mechanical properties of poly(trimethylene terephthalate) (PTT)/multiwalled carbon nanotube (MWCNT) nanocomposites with varying filler loading of MWCNTs were investigated. High‐resolution transmission electron microscopy was used to determine the distribution of MWCNTs in the PTT matrix. The newly developed nanocomposites show excellent dielectric and EMI shielding properties. Theoretical electrical percolation threshold was achieved at 0.21 wt% loading of MWCNTs, due to the high aspect ratio and the three‐dimensional network formation of MWCNTs. Experimental DC conductivity values were compared with those of theoretical models such as the Voet, Bueche and Scarisbrick models, which showed good agreement. The PTT/3% MWCNT composite showed an EMI shielding value of ～38 dB (99.99% attenuation) with a sample thickness of 2 mm. Power balance was used to determine the actual contribution of reflection, absorption and transmission loss to the total EMI shielding value. The nanocomposites showed good tensile and impact properties and the composite with 2% MWCNTs exhibited an improvement in tensile strength of as much as 96%. © 2018 Society of Chemical Industry     

Feature selection techniques in the context of big data: taxonomy and analysis

Applied Intelligence - Recent advancements in Information Technology (IT) have engendered the rapid production of big data, as enormous volumes of data with high dimensional features grow...     

Enantioselective Organocatalyzed Oxa‐Michael–Aldol Cascade Reactions: Construction of Chiral 4H‐Chromenes with a Trifluoromethylated Tetrasubstituted Carbon Stereocenter

The first organocatalytic asymmetric synthesis of 4H‐chromenes bearing a trifluoromethylated tetrasubstituted carbon center is presented. Chiral secondary amines promote the oxa‐Michael–aldol cascade reaction between alkynals and 2‐trifluoroacetylphenols via iminium–allenamine activation to produce pharmaceutically important heterocycles with excellent enantioselectivities. The proposed reaction can be scaled‐up easily with maintenance of the excellent enantioselectivity.

     

Neuroendocrine Tumor‐Targeted Upconversion Nanoparticle‐Based Micelles for Simultaneous NIR‐Controlled Combination Chemotherapy and Photodynamic Therapy,and Fluorescence Imaging

Although neuroendocrine tumors (NETs) are slow growing, they are frequently metastatic at the time of discovery and no longer amenable to curative surgery, emphasizing the need for the development of other treatments. In this study, multifunctional upconversion nanoparticle (UCNP)‐based theranostic micelles are developed for NET‐targeted and near‐infrared (NIR)‐controlled combination chemotherapy and photodynamic therapy (PDT), and bioimaging. The theranostic micelle is formed by individual UCNP functionalized with light‐sensitive amphiphilic block copolymers poly(4,5‐dimethoxy‐2‐nitrobenzyl methacrylate)‐polyethylene glycol (PNBMA‐PEG) and Rose Bengal (RB) photosensitizers. A hydrophobic anticancer drug, AB3, is loaded into the micelles. The NIR‐activated UCNPs emit multiple luminescence bands, including UV, 540 nm, and 650 nm. The UV peaks overlap with the absorption peak of photocleavable hydrophobic PNBMA segments, triggering a rapid drug release due to the NIR‐induced hydrophobic‐to‐hydrophilic transition of the micelle core and thus enabling NIR‐controlled chemotherapy. RB molecules are activated via luminescence resonance energy transfer to generate ¹O₂ for NIR‐induced PDT. Meanwhile, the 650 nm emission allows for efficient fluorescence imaging. KE108, a true pansomatostatin nonapeptide, as an NET‐targeting ligand, drastically increases the tumoral uptake of the micelles. Intravenously injected AB3‐loaded UCNP‐based micelles conjugated with RB and KE108—enabling NET‐targeted combination chemotherapy and PDT—induce the best antitumor efficacy.     

An enhanced high-speed multi-digit BCD adder using quantum-dot cellular automata

The advent of development of high-performance, low-power digital circuits is achieved by a suitable emerging nanodevice called quantum-dot cellular automata(QCA). Even though many efficient arithmetic circuits were designed using QCA, there is still a challenge to implement high-speed circuits in an optimized manner. Among these circuits, one of the essential structures is a parallel multi-digit decimal adder unit with significant speed which is very attractive for future environments. To achieve high speed, a new correction logic formulation method is proposed for single and multi-digit BCD adder. The proposed enhanced single-digit BCD adder(ESDBA) is 26% faster than the carry flow adder(CFA)-based BCD adder. The multi-digit operations are also performed using the proposed ESDBA, which is cascaded innovatively. The enhanced multi-digit BCD adder(EMDBA) performs two 4-digit and two 8-digit BCD addition 50% faster than the CFA-based BCD adder with the nominal overhead of the area. The EMDBA performs two 4-digit BCD addition 24% faster with 23% decrease in the area, similarly for 8-digit operation the EMDBA achieves 36% increase in speed with 21% less area compared to the existing carry look ahead(CLA)-based BCD adder design. The proposed multi-digit adder produces significantly less delay of(N-1)+3.5 clock cycles compared to the N*One digit BCD adder delay required by the conventional BCD adder method. It is observed that as per our knowledge this is the first innovative proposal for multi-digit BCD addition using QCA.     

Symmetry‐Directed Self‐Assembly of a Tetrahedral Protein Cage Mediated by de Novo‐Designed Coiled Coils

The organization of proteins into new hierarchical forms is an important challenge in synthetic biology. However, engineering new interactions between protein subunits is technically challenging and typically requires extensive redesign of protein–protein interfaces. We have developed a conceptually simple approach, based on symmetry principles, that uses short coiled‐coil domains to assemble proteins into higher‐order structures. Here, we demonstrate the assembly of a trimeric enzyme into a well‐defined tetrahedral cage. This was achieved by genetically fusing a trimeric coiled‐coil domain to its C terminus through a flexible polyglycine linker sequence. The linker length and coiled‐coil strength were the only parameters that needed to be optimized to obtain a high yield of correctly assembled protein cages.     

Tuning mesoporous molecular sieve SBA-15 for the immobilization of α-amylase

The present work describes the immobilization of α-amylase over well ordered mesoporous molecular sieve SBA-15 with different pore diameters synthesized by post synthesis treatment (PST) hydrothermally after reaction at 40°C. The materials were characterized by N₂ adsorption–desorption studies, small angle X-ray diffraction, scanning electron microscopy and high resolution transmission electron microscopy. Since α-amylase obtained from Bacillus subtilis has dimensions of 35 × 40 × 70 Å it is expected that the protein have access to the pore of SBA-15 (PST-120°C) with diameter 74 Å. The pore dimension is appropriate to prevent considerable leaching. The rate of adsorption of the enzyme on silica of various pore sizes revealed the influence of morphology, pore diameter, pore volume and pH.     

Investigation of the antenna characteristics with the impact of hexagonal metamaterial

Antenna miniaturization is a typical trend in contemporary wireless systems, notably for current wireless technology, to meet multiband needs while preserving high transmission qualities. The terahertz (THz) regime is helpful in advanced applications and significantly impacts wireless technology. This paper proposes a double-layered hexagonal split ring resonator (HSRR) based on a microstrip patch antenna (MPA) and analyzes the simulated characteristics. The HSRR width is varied for different thickness “w” values and compares the analysis of with and without HSRR in the antenna. Due to the impact of metamaterials, the optimized antenna produces −44.02-dB return loss, 1.012 voltage standing wave ratio (VSWR), 6.47-dBi gain, and 4.78-dB directivity at 1.8-THz frequency. This proposed antenna is suitable for THz applications, which include high-speed data rate in wireless communication, bio-medical field, and THz spectrometer.