The detailed mechanism of the cobalt(<sc>ii</sc>/<sc>iii</sc>)-catalyzed C–H oxidation has been investigated by using both theoretical and experimental methods.

A polyoxometalate-templated silver thiolate nanocluster, [Ag62(StBu)40(Mo20O66)(Mo6O19)3(CH3CN)2]·(CF3SO3)4 (1), has been isolated, in which a giant peanut-like silver(I)-thiolate cluster [Ag62(StBu)40]22+ encapsulates an unprecedented [Mo20O66]12− polyoxoanion core. It opens new approach for the synthesis of both elusive polyoxometalates and high-nuclearity nanoclusters.

Abstract The multiple possible pathways of high‐valent cobalt catalyzed C−H activation/annulation 2‐benzamidopyridine 1‐oxide with terminal alkyne were investigated in this combined theoretical and experimental study. calculated results indicated that Co III activation occurs via a concerted‐metalation deprotonation (CMD) process the subsequent annulation involves IV intermediate generated through proton‐coupled electron transfer (PCET) DMSO solvent or an intermolecular single (SET)...

A new and selective C–N bond oxidative cleavage method to 3-acylated indoles by Pd-catalyzed cross coupling of with α-amino carbonyl compounds has been developed; moreover, one-pot synthesis from 2-ethynylanilines also established. Importantly, the products can be used construct polyheterocyclic compound, which employed as efficient probes for Hg2+ Fe3+.

The construction of steel pipe piles combined with side grouting is regarded as an effective way to improve the uplift bearing capacity for transmission towers in rugged mountainous areas. This new piling technology involves injection grout into annular space between pile and boundary pre-dug hole, which aims properties soil-pile interface. However, date, there are few studies on interface property failure model this kind grouting. In study, shear soil plate were investigated, then compared...

As widely used Lewis acidic metals, Cu and Zn possess distinct redox properties coordination modes, potentially leading to different radical addition mechanisms. Achieving precise control over the stereoselectivity of...

Background The incidence of primary lung cancer (LC) in children and adolescence was rare. We analyzed data from a SEER database to better define the incidence, clinical characters, pathology, treatment, outcomes rare malignant pulmonary tumors childhood adolescence. Methods Patients were chosen (SEER*Stat 8.4.0 software) 2000 2019 all patients pathologically diagnosed with bronchus. Demographic characteristics (age, gender, race, site, laterality, location, differentiation grade, operation...

The mechanisms and chemo- stereo-selectivities of PBu3-catalyzed intramolecular cyclizations N-allylic substituted α-amino nitriles leading to functionalized pyrrolidines (5-endo-trig cyclization, Mechanism A) their competing reaction another kind pyrrolidine (5-exo-trig B) have been investigated using density functional theory (DFT). Multiple possible pathways associated with four different isomers (RR, SR, RS, SS) for A, two (R S) B studied. calculated results indicate that the Gibbs free...

In recent years, the N-protonated chiral oxazaborolidine has been utilized as Lewis acid catalyst for asymmetric insertion reaction, which is one of most challenging topics in current organic chemistry. Nevertheless, reaction mechanism, stereoselectivity, and regioselectivity this novel are still unsettled to date. present work, density functional theory (DFT) investigation performed interrogate mechanisms stereoselectivities formal C-C/H between benzaldehyde methyl α-benzyl diazoester...

Background: This study assesses immune checkpoint inhibitors' efficacy for non-small-cell lung cancer (NSCLC) with brain metastases (BM) and explores the role of cranial radiation therapy (CRT) in immunotherapy era. Methods: The retrospective analysis screened NSCLC patients BMs from July 2018 to December 2021. Treatment involved chemotherapy combined inhibitors as first-line, divided into CRT non-CRT groups. Overall survival (OS), progression-free intracranial were calculated compared....

The mechanism and stereoselectivity of a Lewis acid catalyzed carbonyl–ene reaction trifluoropyruvates with arylpropenes have been investigated using DFT method.

A novel metal-free iodine-mediated intramolecular oxidative cyclization protocol is presented, which allows for the preparation of various 2-substituted benzothiazoles.

Compared with other structures, steel structures have many advantages, such as high strength, small weight, large ductility, good seismic performance, fast construction progress, flexible layout and reusable construction. However, the problem of fire resistance is its fatal flaw. Because material properties changed significantly temperature rising, especially structure cracks, which brought considerable losses to people's lives property. Therefore, considering temperature, we introduced load...

A new strategy for the synthesis of 3-methylene-2,3-dihydro-1<i>H</i>-pyrazoles is presented by Ni-catalyzed oxidative cyclotrimerization α-amino ketones. This unprecedented method allows three ketones to undergo sequential multiple deprotonations and deamination through two C–C bonds one N–N bond formation cascade.

Background Limited evidence exists regarding the comparative effectiveness of lobectomy (L) and sublobar resection (sub-L) for early-stage small cell lung cancer (SCLC).Methods We identified patients with stage I (pT1-T2aN0M0) SCLC who underwent definitive surgery from Surveillance, Epidemiology, End Results (SEER) database between 2004 2019. Overall survival (OS) cancer-specific death (LCSD) were assessed using Kaplan-Meier analysis, Cox regression model competing risk analysis. Propensity...

Determination of rock mass deformation modulus (Erm) is an important but very challenging task in mechanics and engineering. Direct measurements Erm by in-situ tests are expensive, time-consuming, sometimes even impossible. Since the nondestructive easy geophysical method commonly used to measure P-wave velocity (Vp) field, study has developed empirical correlation between Vp based on 834 collected datasets considering both inherent transformation uncertainties. The information criteria...

The detailed mechanisms of the Lewis acid‐catalyzed transesterification β‐oxodithioesters at a solvent‐free condition were studied using density functional theory. Five possible reaction pathways, including one noncatalyzed (channel 1) and four channels (SnCl 2 ‐catalyzed 3 SnCl ·2H O‐catalyzed 4 5), investigated. Our calculated results indicate that energy barriers catalyzed are significantly lower than channel 1. Channel 5, which has an barrier 33.70 kcal/mol as B3LYP/[6‐31G(d, p)+LANL2DZ]...

A novel, regioselective protocol for the synthesis of diphenylmethane derivatives has been developed by using iron-­catalyzed Friedel-Crafts reaction arenes with benzyl thiocyanates. In presence FeBr3, a variety thiocyanates underwent to selectively afford corresponding diarylmethane in moderate high yields.

This study takes a new Shidao tunnel where the left line constructing in weak rock mass as case study, and effect of on existed are studied by numerical analysis. High-precision field investigations conducted to provide accurate parameters for model. The modified generalized Zhang-Zhu (GZZ) constitutive model is applied, analysis results containing horizontal convergence displacement side walls longitudinal crack validated real-time monitoring. vertical vault, adjacent wall, plastic zone...

Deep learning can effectively learn the characteristics of data, which is great significance to development artificial intelligence. This article first outlines deep learning, then describes four typical algorithms, and presents progress current in optimization algorithms After a review, it finally discusses advantages disadvantages data analysis, model building, algorithm optimization, as well problems that need be further studied resolved.

Compared with other structures, steel structures have many advantages, such as high strength, small weight, large ductility, good seismic performance, fast construction progress, flexible layout and reusable construction. However, the problem of fire resistance is its fatal flaw. Because material properties changed significantly temperature rising, especially structure cracks, which brought considerable losses to people's lives property. Therefore, considering temperature, we introduced load...