Machine Learning Study of Methane Activation by O-Centered Radicals over Metal Oxide Clusters.

Methane activation, a "holy grail" in chemistry, is crucial for producing value-added chemicals. Metal oxide clusters (MOCs) that activate methane through oxygen-centered radicals (O) have been extensively studied. However, a systematic and quantitative understanding of the electronic factors that govern the reactivity of the O radicals toward methane is still missing.

Decreased bromate formation but inadvertently increased toxicity in the chloramination-ozonation process: Essential roles of halamines in generating halogenated and nitrogenous byproducts.

The prechloramination followed by post-ozonation (NHCl-O) process has been widely recognized for its effectiveness in suppressing bromate (BrO) formation. However, the presence of bromide (Br) during NHCl treatment results in the formation of various halamines. This study reveals that while the NHCl-O process reduces BrO formation, it leads to a substantial increase in overall cytotoxicity (from 2.

Effects of Different Types of Microplastics on Cold Seep Microbial Diversity and Function.

The massive production and widespread use of plastics have resulted in a growing marine plastic pollution problem. Cold seep ecosystems are maintained by microorganisms related to nitrogen and carbon cycling that occur in deep-sea areas, where cold hydrocarbon-rich water seeps from the ocean floor. Little is known about plastic pollution in this ecosystem.

[Efficacy analysis of 3D printing prefixed nail path model assisted lumbar and sacral hemivertebra orthopaedic surgery].

Objective: To analyze the safety and effectiveness of 3D printing prefabricated nail path model assisted lumbosacral hemivertebra orthopaedic surgery.

Methods: A retrospective analysis was performed on 8 patients with lumbosacral hemivertebra deformity admitted from January 2016 to July 2021, including 3 males and 5 females, aged 6 to 15 at the time of surgery. The hemivertebra of 4 cases located on the left side and 4 cases on the right side.

Methane seepage leads to a specific microplastic aging process in the simulated cold seep environment.

Marine microplastics pose a significant threat to ecosystems, and deep-sea regions serve as critical sinks for these pollutants. Among these regions, cold seeps harbor relatively high concentrations of microplastics. However, research on the aging of microplastics under low-temperature, dark, methane-abundant, and high-pressure conditions remains limited.

Exploring optimal incubation conditions and characteristics of methane oxidizing organisms in deep-sea environments.

Anaerobic methanotrophic archaea (ANME) play key roles in buffering the methane budget in the deep-sea environment. This study aimed to explore the optimal environmental conditions for ANME enrichment. The result showed that the sample at 10.

Nonlinear differential equations and their application to evaluating the integrated impacts of multiple parameters on the biochemical safety of drinking water.

The present study aimed to narrow such gaps by applying nonlinear differential equations to biostability in drinking water. Biostability results from the integrated dynamics of nutrients and disinfectants. The linear dynamics of biostability have been well studied, while there remain knowledge gaps concerning nonlinear effects.

Exploring carbon content variation in microplastics sequestrated from seawater to sediment in the Haima cold seep area.

In the decades since plastic has become widely used, deep-sea areas, specifically cold seeps, have developed into plastic sinks. Cold seeps contain clean energy natural gas hydrates and act as a barrier reducing methane migration to the upper water column. However, the impacts of microplastics (MPs) on the carbon content in the cold seep remain unclear.

On the performance of the M-C (M = Fe, Ru, Os) unit toward methane activation.

Gas-phase reactions of [MC] (M = Os and Ru) with methane at ambient temperature have been studied by using quadrupole-ion trap (Q-IT) mass spectrometry combined with quantum chemical calculations. Theoretical calculations reveal the influence of electronic signatures and that it is the energy gap of the associated frontier molecular orbitals that dominates the ability of the cluster in the initial HC-H bond breaking. By extension, a theoretical consideration upon changing the ligand from carbide to carbyne and eventually to carbene reveals that the reactivities of the M-complex (M = Os, Ru and Fe) are determined by the energy gap of the involved orbitals.

Methane Activation by [OsC]: Implications for Catalyst Design.

Gas-phase reactions of [OsC] with methane at ambient temperature have been studied by using quadrupole-ion trap mass spectrometry combined with quantum chemical calculations. The comparison of [OsC] with the product clusters revealed significant changes in cluster reactivity. In particular, with different ligands, the cluster may produce multiple products or, alternatively, just a single product.

Tracing the Century-Long Evolution of Microplastics Deposition in a Cold Seep.

Microplastic (MP) pollution is one of the greatest threats to marine ecosystems. Cold seeps are characterized by methane-rich fluid seepage fueling one of the richest ecosystems on the seafloor, and there are approximately more than 900 cold seeps globally. While the long-term evolution of MPs in cold seeps remains unclear.

Iridium Dimer Anion-Mediated C≡C Triple Bond Cleavage and Successive Dehydrogenation of Acetylene in the Gas Phase.

The reactions of the iridium dimer anion [Ir] with acetylene have been studied by mass spectrometry in the gas phase, which indicate that the [Ir] anion can consecutively react with CH molecules to form the [IrC] ( = 1, 2) and [IrCH] ( = 3-5) anions as major products with the successive release of H molecules at room temperature. The reactions are confirmed by the reactions of the mass-selected product [IrC] anion with CH to produce [IrC] and [IrCH] ( = 3-5). Photoelectron spectra and quantum chemistry calculations confirm that the [IrC] ( = 1, 2) product anions possess cyclic [Ir(μ-C)Ir] and [Ir(μ-C)(μ-C)Ir] structures, implying that the robust C≡C triple bond of acetylene can be completely cleaved by the [Ir] anion.

Quadruple C-H Bond Activations of Methane by Dinuclear Rhodium Carbide Cation [RhC].

The structure of the [RhC] ion and its reaction with CH in the gas phase have been studied by infrared photodissociation spectroscopy and mass spectrometry in conjunction with quantum chemical calculations. The [RhC] ion is characterized to have an unsymmetrical linear [Rh-C-C-C-Rh] structure existing in two nearly isoenergetic spin states. The [RhC] ion reacts with CH at room temperature to form [RhC] + CH and [RhCH] + CH as the major products.

Survival analysis for older patients with epidermal growth factor receptor mutation-positive advanced non-small cell lung cancer after progression of first-line gefitinib.

Aim: Currently, little studies focus on treatment strategies and survival after progression of gefitinib in older patients with epidermal growth factor receptor )EGFR( mutant advanced non-small-cell lung cancer (NSCLC). The aim of this study was to investigate the influence of different treatment modalities on survival after progression of gefitinib in older patients.

Methods: This is a retrospective analysis included 62 consecutively recruited EGFR-mutant advanced NSCLC patients aged over 70 years who failed first-line gefitinib between 2008 and 2018.

Reactions of Transition-Metal Carbyne Cations with Ethylene in the Gas Phase.

The reactions of iridium- and osmium-carbyne hydride cations [HIrCH] and [HOsCH] with ethylene have been studied using mass spectrometry with isotopic-labeling in the gas phase. The carbyne reactivity is compared with that of the rhodium, cobalt, and iron analogues [TMCH] (TM = Fe, Co, and Rh), which were determined to have the carbene structures. Besides the cycloaddition/dehydrogenation reaction in forming the [TMCH] + H (TM = Ir and Os) products, a second reaction pathway producing the [TMCH] ion and CH via triple hydrogen atom transfer reactions to the carbyne carbon is observed to be the major channel.

Methylation of transcription factor YY2 regulates its transcriptional activity and cell proliferation.

Yin Yang 1 (YY1) is a multifunctional DNA-binding transcription factor shown to be critical in a variety of biological processes, and its activity and function have been shown to be regulated by multitude of mechanisms, which include but are not limited to post-translational modifications (PTMs), its associated proteins and cellular localization. YY2, the paralog of YY1 in mouse and human, has been proposed to function redundantly or oppositely in a context-specific manner compared with YY1. Despite its functional importance, how YY2's DNA-binding activity and function are regulated, particularly by PTMs, remains completely unknown.

Striking Doping Effects on Thermal Methane Activation Mediated by the Heteronuclear Metal Oxides [XAlO ] (X=V, Nb, and Ta).

The thermal reactivity of the heteronuclear metal-oxide cluster cations [XAlO ] (X=V, Nb, and Ta) towards methane has been studied by using mass spectrometry in conjunction with quantum mechanical calculations. Experimentally, a hydrogen-atom transfer (HAT) from methane is mediated by all the three oxide clusters at ambient conditions. However, [VAlO ] is unique in that this cluster directly transforms methane into formaldehyde.

A Tin Analogue of Carbenoid: Isolation and Reactivity of a Lithium Bis(imidazolin-2-imino)stannylenoid.

The lithium bis(imino)stannylenoid (NIPr)2 Sn(Li)Cl (1; NIPr=bis(2,6-diisopropylphenyl)imidazolin-2-imino) was prepared by the reaction of LiNIPr with 0.5 equiv of SnCl2 ⋅diox (diox=1,4-dioxane) and the ambiphilic character of the compound was demonstrated by investigations into its reactivity. Treatment of 1 with I2 or MeI yielded the oxidative addition products (NIPr)2 SnI2 and (NIPr)2 Sn(Me)I, respectively.