Data-Based Prediction of Redox Potentials via Introducing Chemical Features into the Transformer Architecture.

Rapid and accurate prediction of basic physicochemical parameters of molecules will greatly accelerate the target-orientated design of novel reactions and materials but has been long challenging. Herein, a chemical language model-based deep learning method, TransChem, has been developed for the prediction of redox potentials of organic molecules. Embedding an effective molecular characterization (combining spatial and electronic features), a nonlinear molecular messaging approach (Mol-Attention), and a perturbation learning method, TransChem, shows high accuracy in predicting the redox potential of organic radicals comprising over 100,000 data ( > 0.

Nucleophilicity Prediction Using Graph Neural Networks.

The quantitative description between chemical reaction rates and nucleophilicity parameters plays a crucial role in organic chemistry. In this regard, the formula proposed by Mayr et al. and the constructed reactivity database are important representatives.

DFT insights into the Ni-catalyzed regioselective hydrocarboxylation of unsaturated alkenes with CO.

The nickel-catalyzed hydrocarboxylation of alkenes using carbon dioxide has recently become an appealing method to prepare functionalized carboxylic acids with high efficiency and regioselectivity. Herein, density functional theory (DFT) calculations were conducted on the Ni-catalyzed hydrocarboxylation of aryl-/alkyl-substituted alkenes with CO. The α- and β-carboxylation of aromatic and aliphatic olefins originate from distinct catalytic cycles: H-transfer-carboxylation and carboxylation-H-transfer pathways.

Catalytic asymmetric reductive hydroalkylation of enamides and enecarbamates to chiral aliphatic amines.

To increase the reliability and success rate of drug discovery, efforts have been made to increase the C(sp) fraction and avoid flat molecules. sp-Rich enantiopure amines are most frequently encountered as chiral auxiliaries, synthetic intermediates for pharmaceutical agents and bioactive natural products. Streamlined construction of chiral aliphatic amines has long been regarded as a paramount challenge.

A mechanistic study on Cu(i) catalyzed carboxylation of the C-F bond with CO: a DFT study.

The Cu(i) catalyzed carboxylation of the C-F bond recently reported by Yu and co-workers is an excellent method for the construction of complex fluoroacrylate compounds with high regioselectivity. In the present study, theoretical calculations were carried out to investigate the detailed mechanism of the catalytic cycle and the origin of regioselectivity. The calculation results reveal that the overall catalytic cycle proceeds via the migratory insertion of difluoroalkene on the boryl-Cu(i) species, synβ-F elimination, transmetalation, and carboxylation steps.

Micro-Lensed Fiber Laser Desorption Mass Spectrometry Imaging Reveals Subcellular Distribution of Drugs within Single Cells.

The visualization of temporal and spatial changes in the intracellular environment has great significance for chemistry and bioscience research. Mass spectrometry imaging (MSI) plays an important role because of its unique advantages, such as being label-free and high throughput, yet it is a challenge for laser-based techniques due to limited lateral resolution. Here, we develop a simple, reliable, and economic nanoscale MSI approach by introducing desorption laser with a micro-lensed fiber.

Surface Modification with Chondroitin Sulfate Targets Nanoparticles to the Neuronal Cell Membrane in the Substantia Nigra.

Localizing nanoparticles on or near cell membranes remains a big challenge. We present a cell membrane targeting complex based on chondroitin sulfate (CS)-conjugated superparamagnetic iron oxide nanoparticles (CS-SPIONs). After SPIONs were injected into the substantia nigra of rats, the subcellular distributions of SPIONs with and without CS modification have been evaluated by transmission electron microscopy (TEM) analysis.

Subcellular distributions of iron oxide nanoparticles in rat brains affected by different surface modifications.

The impact of the surface modification on the subcellular distribution of nanoparticles in the brain remains elusive. The nanoparticles prepared by conjugating polyethylene glycol and maleic anhydride-coated superparamagnetic iron oxide nanoparticles (Mal-SPIONs) with bovine serum albumin (BSA/Mal-SPIONs) and with Arg-Gly-Asp peptide (RGD/Mal-SPIONs) were injected into the rat substantia nigra. Observation of transmission electron microscopy (TEM) samples obtained 24 h after perfusion showed that abundant RGD/Mal-SPIONs accumulated in the myelin sheath, dendrites, axon terminals and mitochondria, and on cell membranes in the brain tissue near the injection site.

Glutathione-s-transferase A 4 (GSTA4) suppresses tumor growth and metastasis of human hepatocellular carcinoma by targeting AKT pathway.

Hepatocellular carcinoma (HCC) is one of the most lethal malignancies of cancers and its prognosis remains dismal due to the paucity of effective therapeutic targets. Up-regulation of glutathione-s-transferase A 4 (GSTA4) is associated with poor prognosis of HCC, but its functional mechanism in HCC remains unclear. In this study, we investigated the roles of GSTA4 in tumor growth and metastasis of HCC and found that GSTA4 was frequently up-regulated in HCC tissues.

Endovascular Treatment for Acute Type B Aortic Dissection Involving a Right-sided Aortic Arch and Kommerell's Diverticulum: A Case Report and Review of the Literature.

Background: Aortic dissection involving a right-sided aortic arch (RAA) associated with Kommerell's diverticulum is extremely rare and remains a complicated entity for surgical therapy because of its anatomical characteristics. Fewer than 40 cases have been reported in the English language literature to date.

Methods: We reported a case of 69-year-old male patient who presented with acute type B aortic dissection involving an RAA associated with Kommerell's diverticulum, a stent-graft was accurately deployed and embolization of the left subclavian artery.