Size and Morphology Dependent Activity of Cu Clusters for CO Activation and Reduction: A First Principles Investigation.

Various Cu-based materials in diverse forms have been investigated as efficient catalysts for electrochemical reduction of CO; however, they suffer from issues such as higher over potential and poor selectivity. The activity and selectivity of CO electro reduction have been shown to change significantly when the surface morphology (steps, kinks, and edges) of these catalysts is altered. In light of this, size and morphology dependent activity of selected copper clusters, Cu (n=2-20) have been evaluated for the activation and reduction of CO molecule.

Bioinspired Diiron Complex with Proton Shuttling and Redox-Active Ligand for Electrocatalytic Hydrogen Evolution.

A μ-oxo diiron complex, featuring the pyridine-2,6-dicarboxamide-based thiazoline-derived redox-active ligand, HL (HL = N,N-bis(4,5-dihydrothiazol-2-yl)pyridine-2,6-dicarboxamide), was synthesized and thoroughly characterized. showed electrocatalytic hydrogen evolution reaction activity in the presence of different organic acids of varying p values in dimethylformamide. Through electrochemical analysis, we found that is a precatalyst that undergoes concerted two-electron reduction to generate an active catalyst.

Optimizing the NRR activity of single and double boron atom catalysts using a suitable support: a first principles investigation.

Designing cost effective transition-metal free electrocatalysts for nitrogen fixation under ambient conditions is highly appealing from an industrial point of view. Using density functional theory calculations in combination with the computational hydrogen electrode model, we investigate the N activation and reduction activity of ten different model catalysts obtained by supporting single and double boron atoms on five different substrates ( GaN, graphene, graphyne, MoS and g-CN). Our results demonstrate that the single/double boron atom catalysts bind favourably on these substrates, leading to a considerable change in the electronic structure of these materials.

Implications of the Pore Size of Graphitic Carbon Nitride Monolayers on the Selectivity of Dual-Boron Atom Catalysts for the Reduction of N to Urea and Ammonia: A Computational Investigation.

The formation of urea by electrocatalytic means remains a great challenge due to the lack of a suitable catalyst that is capable of not only activating inert N and CO molecules but also circumventing the complexity associated with subsequent reaction steps leading to urea formation. Herein, by means of comprehensive density functional theory simulations, we investigate the catalytic activity of highly stable transition-metal-free dual-boron atom-doped graphitic carbon-nitride monolayers with different pore sizes toward urea production under ambient conditions. As per the results, dual boron atoms impregnated in g-CN and g-CN monolayers with large pore diameters can successfully activate the N molecule and lead to the spontaneous formation of the *NCO*N intermediate, which is the most crucial step for urea formation via direct coupling of N and CO.

Probing the Site-Specific Reactivity and Catalytic Activity of Ag ( = 15-20) Silver Clusters.

Density functional theory calculations within the framework of generalized gradient approximation (GGA), meta-GGA, and local functionals were carried out to investigate the reactivity and catalytic activity of Ag ( = 15-20) clusters. Our results reveal that all the Ag clusters in this size range, except Ag, adsorb O preferably in the bridged mode with enhanced binding energy as compared to the atop mode. The O binding energies range from 0.

Role of magnetization on catalytic pathways of non-oxidative methane activation on neutral iron carbide clusters.

Methane has emerged as a promising fuel due to its abundance and clean combustion properties. It is also a raw material for various value-added chemicals. However, the conversion of methane to other chemicals such as olefins, aromatics, and hydrocarbons is a difficult task.

Comparison of percutaneous nephrolithotomy under epidural anesthesia versus general anesthesia: A randomized prospective study.

Introduction: PCNL has revolutionized the treatment of renal calculi putting almost an end to the era of open stone surgery. The procedure can safely be carried out under general anesthesia (GA) or regional anesthesia viz. spinal anesthesia (SA), epidural anesthesia (EA) or combined spinal and epidural anesthesia (CSE).

Surface functionalization: an efficient alternative for promoting the catalytic activity of closed shell gold clusters.

Surface functionalization through adsorption of ligands or non-metal atoms is considered to be an interesting and viable approach for tuning the physicochemical properties of gold clusters. Highly stable and magic numbered electronic configurations of thiolate protected gold clusters such as Au25(SR)18, Au38(SR)24etc. with intriguing properties are the direct manifestation of the rich chemistry of the Au-S interface.

Molecular and Dissociative Adsorption of Oxygen on Au-Pd Bimetallic Clusters: Role of Composition and Spin State of the Cluster.

Utilization of molecular oxygen as an oxidizing agent in industrially important reactions is the ultimate goal to design environmentally benign processes under ambient conditions. However, the high thermal stability and a large O-O dissociation barrier in O molecule pose a great challenge toward its successful application in the oxidative chemistry. To achieve this goal, different catalysts based on monometallic and bimetallic clusters have been developed over the years to promote binding and dissociation of molecular oxygen.

Coloplasty Neorectum versus Straight Anastomosis in Low Rectal Cancers.

Introduction. Patients with the diagnosis of carcinoma rectum after random allocation were assigned to 2 groups. One group was subjected to total mesorectal excision with coloplasty neorectum reconstruction and another group to total mesorectal excision with straight anastomosis.

Cyclin D1 G870A polymorphism and risk of colorectal cancer: a case control study.

The present study aimed to analyse the role of cyclin D1 A870G polymorphism in modulating the susceptibility to colorectal cancer (CRC) in the Kashmiri population. The genotype distribution of the cyclin D1 gene in 130 CRC cases in comparison with 160 healthy controls was investigated. No direct significant association between cyclin D1 genotypes and CRC was observed; however, the AG and AA genotypes were found to be associated with an increased risk of CRC compared to the GG genotype, with an almost 2-fold increase in OR.

Biliary ascariasis as a cause of post-cholecystectomy syndrome in an endemic area.

Background: Post-cholecystectomy syndrome encompasses numerous biliary, pancreatic and other entities. Biliary ascariasis is a common cause of adult biliary disease in an endemic area. Post-cholecystectomy biliary ascariasis, a cause of post- cholecystectomy syndrome although not yet defined is frequently seen in this part of the world.

Surgical management of splenic hydatidosis.

Purpose: This study was conducted to evaluate the surgical management of splenic hydatidosis in an area where the disease is endemic.

Method: Over a period of 16 years, 26 patients with splenic hydatidosis underwent surgery in our department. Preoperative investigations included plain abdominal X-ray, serology, ultrasonography, and computed tomography.

Ascariasis-induced empyema of gallbladder: report of a case.

A rare case of a 52-year-old woman with empyema of the gallbladder due to ascariasis causing an obstruction in the cystic duct is presented. She was admitted on September 20, 2000, and on September 23 an emergency cholecystectomy was performed. Ultrasonography is a highly sensitive and specific method for diagnosing gallbladder ascariasis, and a cholecystectomy is considered mandatory for the treatment of empyema of the gallbladder.