Radii of starlikeness associated with the lemniscate of Bernoulli and the left-half plane

A normalized analytic function f defined on the open unit disk in the complex plane is in the class SL if zf′(z)/f(z) lies in the region bounded by the right-half of the lemniscate of Bernoulli given by ∣w² − 1∣ < 1. In the present investigation, the SL-radii for certain well-known classes of functions are obtained. Radius problems associated with the left-half plane are also investigated for these classes.     

Catalysis by Amberlite IR-120 resin: a rapid and green method for the synthesis of phenols from arylboronic acids under metal, ligand, and base-free conditions

A clean process has been developed for the ipso-hydroxylation of aryl and heteroaryl boronic acids to the corresponding phenols using commercially available and recyclable Amberlite IR-120 resin and aqueous hydrogen peroxide as an oxidizing agent. The ion-exchange sulfonic acid resin catalyst could be readily recycled by filtration and directly reused at least four times without any significant loss of activity.     

An efficient synthesis and structural aspects of hexakis(arylseleno)benzenes and hexakis(arylselenomethyl)benzenes

An efficient synthesis and structural aspects of a novel class of selenium bearing hexa-hosts by the reaction of hexafluorobenzene or hexakis(bromomethyl) benzene with RSe⁻ ions is demonstrated. However, under identical reaction conditions, our attempts to prepare tellurium analogues by the reaction of RTe⁻ (R = Ph or p-CH₃C₆H₄-) with hexafluorobenzene or hexakis(bromomethyl)benzene to obtain (RTe)₆C₆ and (RTeCH₂)₆C₆ proved to be difficult.     

Synthesis and antimicrobial activity of 6,6′‐arylidene‐bis‐[5‐hydroxy‐9‐methyl‐2,3‐diaryl thieno[3,2‐g‐]thiocoumarins]

A variety of novel 6,6′‐arylidene‐bis‐[5‐hydroxy‐9‐methyl‐2,3‐diaryl‐thieno[3,2‐g]thiocoumarins] 3a‐d , 4a‐d , 5a‐d , and 6a‐d were obtained by a reaction between 5‐hydroxy‐9‐methyl‐2,3‐diarylthieno[3,2‐g]thiocoumarins 1a‐d with aromatic aldehydes 2a‐d in isopropyl alcohol. The synthesized compounds were tested for their antimicrobial activity.     

In Vitro Antiviral Activity of α-Mangostin against Dengue Virus Serotype-2 (DENV-2)

Dengue virus (DENV), a member of the family Flaviviridae, is a threat for global health as it infects more than 100 million people yearly. Approved antiviral therapies or vaccines for the treatment or prevention of DENV infections are not available. In the present study, natural compounds were screened for their antiviral activity against DENV by in vitro cell line-based assay. α-Mangostin, a xanthanoid, was observed to exert antiviral activity against DENV-2 under pre-, co- and post-treatment testing conditions. The antiviral activity was determined by foci forming unit (FFU) assay, quantitative RT-PCR and cell-based immunofluorescence assay (IFA). A complete inhibition of DENV-2 was observed at 8 µM under the co-treatment condition. The possible inhibitory mechanism of α-Mangostin was also determined by docking studies. The molecular docking experiments indicate that α-Mangostin can interact with multiple DENV protein targets such as the NS5 methyltransferase, NS2B-NS3 protease and the glycoprotein E. The in vitro and in silico findings suggest that α-Mangostin possesses the ability to suppress DENV-2 production at different stages of its replication cycle and might act as a prophylactic/therapeutic agent against DENV-2.     

Neoteric Advances in Oxygen Bridged Triaryl Boron-based Delayed Fluorescent Materials for Organic Light Emitting Diodes

Since their first demonstration, thermally activated delayed fluorescence (TADF) materials have been emerged as the most promising emitters because of their promising applications in optoelectronics, typified by organic light-emitting diodes (OLEDs). In which, the rigid oxygen bridged boron acceptor-featured ( DOBNA ) emitters have gained tremendous impetus for OLEDs, which is ascribed to their excellent external quantum efficiency (EQE). However, these materials often displayed severe efficiency roll-off and poor operational stability. Therefore, there needs to be a comprehensive understanding of the aspect of the molecular design and structure-property relationship. To the best of our knowledge, there is no detailed review on the structure-function outlook of DOBNA -based emitters emphasizing the effect of the nature of donor units, their number density, and substitution pattern on the physicochemical properties, excited state dynamics and OLED performance were reported. To fill this gap, herein we presented the recent advancements in DOBNA -based acceptor featured TADF materials by classifying them into several subgroups based on the molecular design i. e. donor-acceptor (D−A), D−A-D, A−D-A, and multi-resonant TADF (MR-TADF) emitters. The detailed design concepts, along with their respective physicochemical and OLED performances were summarized. Finally, the prospective of this class of materials in forthcoming OLED displays is also discussed.     

Synthesis of 1D β-MnO2 for high-performance supercapacitor application

Journal of Solid State Electrochemistry - Electrochemical supercapacitors (ESs) still need to overcome development obstacles in order to realize their full potential while being acknowledged as a...     

Electrokinetic demixing of aqueous two-phase polymer/salt systems

Electrokinetic demixing of aqueous two-phase polymer/salt systems is demonstrated, resulting in significant enhancement in demixing rates by about 1-4-fold. The effect of field polarity, field strength, volume ratio, and phase composition on phase demixing has been studied. Further the influence of these parameters on phase demixing could be explained based on the hydrodynamic flow-electroosmotic flow (HEF) model.     

5-hydroxyuracil can form stable base pairs with all four bases in a DNA duplex

NMR studies, UV-monitored melting experiments, and ab initio calculations show that 5-hydroxyuracil, produced by the oxidative de-amination of cytosines by reactive oxygen species, can form stable base-pairs with dA, dG, dC and dT residues in a DNA duplex, providing a basis for the in-vivo incorporation of 5-hydroxyuracil during DNA replication.     

Formal synthesis of 14-membered unsymmetrical bis-macrolactone, (−)-colletodiol

Formal synthesis of 14-membered unsymmetrical bis-macrolactone, (?)-colletodiol was accomplished from homopropargylic alcohol derivative. Building of the two different hydroxy acid fragments from the same intermediate of homoallylic alcohol was particularly advantageous. A Sharpless asymmetric dihydroxylation, homologation of carbon chain, a Pinnick oxidation, and a macrolactonization to assemble the 14-membered macrodiolide were the additional salient features of this convergent synthesis.