Fragment Aligned Molecular Orbital Analysis: An Innovative Tool for Analyzing Atypical Chemical Bonding.

In chemical research, it is a common practice to carry out quantum chemical calculations and analyze the canonical molecular orbitals (CMOs) obtained to study electronic structures of chemical systems. However, extensive orbital mixing of CMOs especially in molecular clusters significantly complicates our understanding of the electronic structures. In this paper, we have developed an innovative tool called fragment aligned molecular orbital (FAMO) analysis, which reconstructs our modular chemical picture by making use of the Procrustes analysis in statistical theory to align the occupied molecular orbitals of a molecular species against the occupied (molecular) orbitals of the constituting fragments of the cluster, and results in a set of chemically intuitive semilocalized orbitals.

Metal-Centered Boron-Wheel Cluster of Y©B with Rare Symmetry.

Molecules with high point-group symmetry are interesting prototype species in the textbook. As transition metal-centered boron clusters tend to have highly symmetric structures to fulfill multicenter bonding and high stability, new boron clusters with rare point-group symmetry may be viable. Through in-depth scrutiny over the structures of experimentally already observed transition metal-centered boron-wheel complexes, geometric and electronic design principles are summarized, based on which we studied M©B ( = Y, La; Zr, Hf; = 1, 2) clusters and found that a Y©B boron-wheel complex has an unprecedented point-group symmetry.

Palladium-Catalyzed Sequential Cross-Coupling/Annulation of -Vinyl Bromobenzene with Aryl Bromide: Bimetallic Pathway versus Pd(II)-Pd(IV) Pathway: A DFT Investigation.

The palladium-catalyzed sequential cross-coupling/annulation of -vinyl bromobenzenes with aryl bromides generating phenanthrenes was characterized by density functional theory (DFT). The Pd(II)-Pd(IV) pathway (Path V) is shown to be less probable than the bimetallic pathway (Path I), the latter proceeding via the following six steps: oxidative addition, vinyl-C(sp)-H activation, Pd(II)-Pd(II) transmetalation, C-C coupling, aryl-C(sp)-H activation, and reductive elimination. The aryl-C(sp)-H activation process acts as the rate-determining step (RDS) of the entire chemical transformation, with an activation free energy barrier of ca.

Vagus nerve stimulation-induced stromal cell-derived factor-l alpha participates in angiogenesis and repair of infarcted hearts.

Aims: We aim to explore the role and mechanism of vagus nerve stimulation (VNS) in coronary endothelial cells and angiogenesis in infarcted hearts.

Methods And Results: Seven days after rat myocardial infarction (MI) was prepared by ligation of the left anterior descending coronary artery, the left cervical vagus nerve was treated with electrical stimulation 1 h after intraperitoneal administration of the α7-nicotinic acetylcholine inhibitor mecamylamine or the mAChR inhibitor atropine or 3 days after local injection of Ad-shSDF-1α into the infarcted heart. Cardiac tissue acetylcholine (ACh) and serum ACh, tumour necrosis factor α (TNF-α), interleukin 1β (IL-1β) and interleukin 6 (IL-6) levels were detected by ELISA to determine whether VNS was successful.

Pd-NHC catalysed regioselective activation of B(3,6)-H of -carborane - a synergy between experiment and theory.

Regioselective B-H activation of -carboranes is an effective way for constructing -carborane derivatives, which have broad applications in medicine, catalysis and the wider chemical industry. However, the mechanistic basis for the observed selectivities remains unresolved. Herein, a series of density functional theory (DFT) calculations were employed to characterise the palladium N-heterocyclic carbene (Pd-NHC) catalysed regioselective B(3,6)-diarylation of -carboranes.

The spatiotemporal matching pattern of Ezrin/Periaxin involved in myoblast differentiation and fusion and Charcot-Marie-Tooth disease-associated muscle atrophy.

Background: Clinically, Charcot-Marie-Tooth disease (CMT)-associated muscle atrophy still lacks effective treatment. Deletion and mutation of L-periaxin can be involved in CMT type 4F (CMT4F) by destroying the myelin sheath form, which may be related to the inhibitory role of Ezrin in the self-association of L-periaxin. However, it is still unknown whether L-periaxin and Ezrin are independently or interactively involved in the process of muscle atrophy by affecting the function of muscle satellite cells.

Continuous exposure to isoprenaline reduced myotube size by delaying myoblast differentiation and fusion through the NFAT-MEF2C signaling pathway.

We aimed to explore whether superfluous sympathetic activity affects myoblast differentiation, fusion, and myofiber types using a continuous single-dose isoprenaline exposure model in vitro and to further confirm the role of distinct NFATs in ISO-mediated effects. Compared with delivery of single and interval single, continuous single-dose ISO most obviously diminished myotube size while postponing myoblast differentiation/fusion in a time- and dose-dependent pattern, accompanied by an apparent decrease in nuclear NFATc1/c2 levels and a slight increase in nuclear NFATc3/c4 levels. Overexpression of NFATc1 or NFATc2, particularly NFATc1, markedly abolished the inhibitory effects of ISO on myoblast differentiation/fusion, myotube size and Myh7 expression, which was attributed to a remarkable increase in the nuclear NFATc1/c2 levels and a reduction in the nuclear NFATc4 levels and the associated increase in the numbers of MyoG and MEF2C positive nuclei within more than 3 nuclei myotubes, especially in MEF2C.

Bonding Nature of "Ionic Carbenes" in [M(μ-CH)]-Containing Compounds: The Covalent Interaction.

While a series of trinuclear rare-earth metal methylene (divalent >CH) complexes with the so-called "ionic carbene" have been known for decades, the nature of metal-carbene interactions in this class of compounds remains elusive. Herein, a quantum chemical investigation has been performed to reveal the bonding nature in typical trimetallic "ionic carbene" species with the [M(μ-CH)] (M = Sc, Y, La, and Ac) cluster core. Through various chemical bonding analyses, we have demonstrated that there exists a non-negligible covalent interaction between μ-CH and M moieties, and the chemical bonding can be accounted for with two three-center two-electron (3c-2e) bonds.

Uncovering mechanisms of RT-LAMP colorimetric SARS-CoV-2 detection to improve assay reliability.

Improved diagnostics are needed to manage the ongoing COVID-19 pandemic. In this study, we enhanced the color changes and sensitivity of colorimetric SARS-CoV-2 RT-LAMP assays based on triarylmethane dyes. We determined a mechanism for the color changes and obtained sensitivities of 10 RNA copies per microliter.

Histone Lysine Methylation and Long Non-Coding RNA: The New Target Players in Skeletal Muscle Cell Regeneration.

Satellite stem cell availability and high regenerative capacity have made them an ideal therapeutic approach for muscular dystrophies and neuromuscular diseases. Adult satellite stem cells remain in a quiescent state and become activated upon muscular injury. A series of molecular mechanisms succeed under the control of epigenetic regulation and various myogenic regulatory transcription factors myogenic regulatory factors, leading to their differentiation into skeletal muscles.

The water extracts of Euonymus alatus (Thunb.) Siebold attenuate diabetic retinopathy by mediating angiogenesis.

Ethnopharmacological Relevance: Euonymus alatus (Thunb.) Siebold (family Celastraceae) is a deciduous woody shrub that is recorded in ShenNong BenCaoJing. It has been widely used for diabetes in traditional Chinese medicine.

Rod-Shaped Silver Supercluster Unveiling Strong Electron Coupling between Substituent Icosahedral Units.

The first linear silver supercluster based on icosahedral Ag units has been constructed via bridging of dpa ligands: Ag(dpa)(SbF) (Hdpa = dipyridylamine) (). Single-crystal X-ray diffraction reveals that this rod-shaped cluster consists of four vertex-sharing Ag icosahedra in a linear arrangement. This cluster represents the longest one-dimensional metal nanocluster with a resolved structure.

Spatio-temporal model of Meox1 expression control involvement of Sca-1-positive stem cells in neointima formation through the synergistic effect of Rho/CDC42 and SDF-1α/CXCR4.

Aims: Neointimal hyperplasia remains a major obstacle in vascular regeneration. Sca-1-positive progenitor cells residing within the vascular adventitia play a crucial role in the assemblage of vascular smooth muscle cell (VSMC) and the formation of the intimal lesion. However, the underlying mechanisms during vascular injury are still unknown.

Superatomic Ligand-Field Splitting in Ligated Gold Nanoclusters.

Gold nanoclusters are attractive because of their electronic and optical properties. Many theoretical models have been proposed to explain their electronic structures through an electron-counting approach. However, subtle features may not be well explained by electron-counting rules.

Principal interacting spin orbital: understanding the fragment interactions in open-shell systems.

Due to the recent rise in the interest and research efforts on first-row transition metal catalysis and other radical-related reactions, open-shell systems play a much more important role in modern chemistry. However, the development of bonding analysis tools for open-shell systems is still lagging behind. In this work, we present the principal interacting spin orbital (PISO) analysis, which is an analysis framework developed based on our previously reported principal interacting orbital (PIO) analysis.

[Comparative study on chronic multiple organ injury in normal rats caused by high dose of Tripterygium Glycosides Tablets from 6 different manufacturers].

The aim of this paper was to compare different effects of Tripterygium Glycosides Tablets from 6 different manufacturers on multiple organ injuries in rats and to explore mechanism of hepatotoxicity preliminarily from the perspective of apoptosis and oxidative stress. Rats were randomly divided into the groups normal, Zhejiang, Hunan, Hubei, Shanghai, Jiangsu and Fujian(7 groups with 16 rats in each group, sex in half). Rats were given Tripterygium Glycosides Tablets at 144 mg·kg~(-1)·d~(-1)(16 times the clinical equivalent dose) once a day according to its corresponding group like rats in Zhejiang group was given Tripterygium Glycosides Tablets from Zhejiang manufactures continuously for 20 days with the life and death situation of mice to be observed, then rats were executed to detect various indicators.

[Effects of Tripterygium Glycosides Tablets from 6 different manufacturers on acute liver injury of normal mice].

The aim of this paper was to compare the performance of acute liver injury in mice induced by Tripterygium Glycosides Tablets from 6 different manufacturers,and to explore the toxicity mechanism from the perspective of oxidative stress and apoptosis preliminarily. Male or female mice were randomly divided into normal group,Zhejiang group,Hunan group,Hubei group,Shanghai group,Jiangsu group and Fujian group. Mice in Tripgerygium Glycosides Tablets groups were given 16 times the clinical equivalent dose( 300 mg·kg-1) Tripgerygium Glycosides Tablets by oral administration for one time,mice were executed in 24 h after lavaged.

Inter-ligand delocalisations in transition metal complexes containing multiple non-innocent ligands.

Systematic bonding analysis has been carried out for transition metal complexes containing more than one redox-active/non-innocent ligand. These complexes include tetralithio spiroaromatic palladole, dicupra[10]annulene, highly reduced nickel cyclooctadiene complex and tris(dithiolene)vanadium(iv). Our detailed bonding analysis reveals a common inter-ligand delocalisation pattern in these cases.

Synthesis, structure and DFT calculations of mononuclear cyclic (alkyl)(amino) carbene supported titanium(ii) complexes.

The mononuclear cyclic (alkyl)(amino)carbene (cAAC) supported titanium(iii) chloride complex [(cAAC)2TiCl3] has been synthesized by treatment of free cAAC with TiCl3(THF)3. Further reduction of (cAAC)2TiCl3 with potassium graphite (KC8) afforded the desired (cAAC)2TiCl2 complex, which features a small S-T energy gap. Both complexes were structurally characterized and represent the first cAAC supported Ti complexes.

[Expression Levels of JARID1B, Hes1 and MMP-9 Genes in CML Patients Treated with Imatinib Mesylate].

Objective: To explore the relationship between the expression levels of JARID1B,Hes1 and MMP-9 genes and the stages of chronic myelogenous leukemia(CML) and the curative effect of imatinib mesylate (IM).

Methods: Peripheral blood samples of 15 cases of CML in chronic phase and 10 cases of CML in progressive phase were collected from the Hematology Department of Taihe Hospital affiliated to Hubei University of Medicine and 15 cases of healthy people in the Physical Examination Center. CML patients were divided into effective group and ineffective group based on the efficacy after treatment with IM, then real-time PCR was used to detect the expression levels of JARID1B, Hes1 and MMP-9 mRNA, finally, the differences in the level of gene expression and their correlations with CML stages and IM curative efficacy were analysed.

Effect of 2″--Rhamnosyl Icariside II, Baohuoside I and Baohuoside II in Herba Epimedii on Cytotoxicity Indices in HL-7702 and HepG2 Cells.

Herba Epimedii, a commonly used Chinese medicine, has attracted much attention recently because of its potential hepatotoxic effects. 2″--Rhamnosyl icariside II, baohuoside I and baohuoside II are the main components of Herba Epimedii, and previous research indicates that these three compounds are related to the hepatotoxicity of Herba Epimedii. To test this idea, in this study, HL-7702 and HepG2 cells were chosen as the in vitro models and the influences of these three compounds on a series of cytotoxicity indices, including ALT, AST, LDH, SOD, GSH, MDA, ROS and MMP, were determined.

Continuous exposure of isoprenaline inhibits myoblast differentiation and fusion through PKA/ERK1/2-FOXO1 signaling pathway.

Aim: The objective of this study is to determine if exuberant sympathetic nerve activity is involved in muscle satellite cell differentiation and myoblast fusion.

Methods And Results: By using immunoassaying and western blot analyses, we found that β1 and β2-adrenergic receptors (AdR) were expressed in C2C12 cells. The differentiated satellite cells exhibited an increased expression of β2-AdR, as compared with the proliferating cells.

Remote Bonding in Clusters [PdGeR]: Modular Bonding Model for Large Clusters via Principal Interacting Orbital Analysis.

Main group cluster compounds have attracted increasing attention in the past decades. Despite recent developments in their synthesis, the description of their electronic structures is usually limited to simply applying Wade's rule originally developed for borane compounds. This traditional approach is once again challenged by two recently reported group 14 metalloid clusters in the form of [PdGeR].