Uncatalyzed Diboron Activation by a Strained Hydrocarbon: Experimental and Theoretical Study of [1.1.1]Propellane Diborylation.

The synthesis of strained carbocyclic building blocks is relevant for Medicinal Chemistry, and methylenecyclobutanes are particularly challenging with current synthetic technology. Careful inspection of the reactivity of [1.1.

Effects of electroacupuncture combined with paliperidone palmitate long-acting injection on withdrawal symptoms and neurotransmitters in methamphetamine addicts.

Objective: To investigate the effects of electroacupuncture combined with paliperidone palmitate long-acting injection (PP-LAI) on withdrawal symptoms and neurotransmitters in methamphetamine (MA) addicts.

Materials And Methods: A total of 109 methamphetamine addicts, who were treated in the hospital from October 2021 to October 2022, were selected. According to the random number table, the patients were divided into the study group (n=54) and the control group (n=55), in which the control group was treated with PP-LAI and the study group was treated with electroacupuncture on the basis of the control group; the methamphetamine withdrawal symptom score scale was used to assess the therapeutic effect before treatment and within 12 months after treatment; the changes of brain neurotransmitters dopamine, γ-aminobutyric acid, serotonin, acetylcholine values were compared between the two groups.

Life disturbance and hospital visit experiences among Chinese patients with benign prostatic hyperplasia: a qualitative study.

Background: The impact of lower urinary tract symptoms (LUTS) on the quality of life of patients with benign prostatic hyperplasia (BPH) has been rarely reported. Additionally, the challenges faced by these patients in seeking medical care have often been overlooked. In order to explore the personal struggles caused by LUTS and the difficulties or barriers experienced by Chinese patients with BPH when seeking help, we conducted a qualitative interview study.

The energetics of N reduction by vanadium containing nitrogenase.

The main class of nitrogenases has a molybdenum in its cofactor. A mechanism for Mo-nitrogenase has recently been described. In the present study, another class of nitrogenases has been studied, the one with a vanadium instead of a molybdenum in its cofactor.

ARID1A Inactivation Increases Expression of circ0008399 and Promotes Cisplatin Resistance in Bladder Cancer.

Objective: Cisplatin (CDDP)-based chemotherapy is a first-line, drug regimen for muscle-invasive bladder cancer (BC) and metastatic bladder cancer. Clinically, resistance to CDDP restricts the clinical benefit of some bladder cancer patients. AT-rich interaction domain 1A (ARID1A) gene mutation occurs frequently in bladder cancer; however, the role of CDDP sensitivity in BC has not been studied.

A Mechanism for Nitrogenase Including Loss of a Sulfide.

Nitrogenase is the only enzyme in nature that can fix N from the air. The active cofactor of the leading form of this enzyme contains seven irons and one molybdenum connected by sulfide bridges. In several recent experimental studies, it has been suggested that the cofactor is very flexible, and might lose one of its sulfides during catalysis.

The active E4 structure of nitrogenase studied with different DFT functionals.

The present study concerns the technical aspects of obtaining the energetics for the E4 state of nitrogenase, the enzyme that fixes N in nature. EPR experiments have shown that the critical E4 structure that activates N should contain two bridging hydrides in the FeMo-cofactor. It is furthermore in equilibrium with a structure where the two hydrides have been released and N binds.

Computational Understanding of the Selectivities in Metalloenzymes.

Metalloenzymes catalyze many different types of biological reactions with high efficiency and remarkable selectivity. The quantum chemical cluster approach and the combined quantum mechanics/molecular mechanics methods have proven very successful in the elucidation of the reaction mechanism and rationalization of selectivities in enzymes. In this review, recent progress in the computational understanding of various selectivities including chemoselectivity, regioselectivity, and stereoselectivity, in metalloenzymes, is discussed.

Deciphering the chemoselectivity of nickel-dependent quercetin 2,4-dioxygenase.

The reaction mechanism and chemoselectivity of nickel-dependent quercetin 2,4-dioxygenase (2,4-QueD) have been investigated using the QM/MM approach. The protonation state of the Glu74 residue, a first-shell ligand of Ni, has been considered to be either neutral or deprotonated. QM/MM calculations predict that Glu74 must be deprotonated to rationalize the chemoselectivity and steer the 2,4-dioxygenolytic cleavage of quercetin, which harvests the experimentally-observed product, 2-protocatechuoylphloroglucinol carboxylic acid, coupled with the release of carbon monoxide.

Iron-Catalyzed Regiospecific Intermolecular Radical Cyclization of Anilines: Strategy for Assembly of 2,2-Disubstituted Indolines.

The first regiospecific catalytic intermolecular assembly of 2,2-disubstituted indolines has been developed. This protocol is based on a ligand and directing group free, iron-catalyzed radical [3 + 2] process, allowing efficient coupling of different N-sulfonylanilines with various α-substituted styrenes. Preliminary mechanistic studies elucidated the radical mechanism involving a reactive and versatile anilino radical and the importance of iron complex as a Lewis acid, rendering both the reactivity and regiospecificity of this transformation.

Nonredox Metal Ions Promoted Olefin Epoxidation by Iron(II) Complexes with HO: DFT Calculations Reveal Multiple Channels for Oxygen Transfer.

Nonredox metal ions play significant roles in a wide range of biological and chemical oxidations in which they can modulate the oxidative reactivity of those redox metal ions. With environmentally benign HO as oxidant, the influence of nonredox metal ions on an iron(II) complex mediated olefin epoxidation was investigated through experimental studies and theoretical calculations. It was found that adding nonredox metal ions like Sc can substantially improve the oxygen transfer efficiency of the iron(II) complex toward cyclooctene epoxidation even in the presence of certain amount of water.

Theoretical Study of the Mechanism of the Nonheme Iron Enzyme EgtB.

EgtB is a nonheme iron enzyme catalyzing the C-S bond formation between γ-glutamyl cysteine (γGC) and N-α-trimethyl histidine (TMH) in the ergothioneine biosynthesis. Density functional calculations were performed to elucidate and delineate the reaction mechanism of this enzyme. Two different mechanisms were considered, depending on whether the sulfoxidation or the S-C bond formation takes place first.

Mutant huntingtin downregulates myelin regulatory factor-mediated myelin gene expression and affects mature oligodendrocytes.

Growing evidence indicates that non-neuronal mutant huntingtin toxicity plays an important role in Huntington's disease (HD); however, whether and how mutant huntingtin affects oligodendrocytes, which are vitally important for neural function and axonal integrity, remains unclear. We first verified the presence of mutant huntingtin in oligodendrocytes in HD140Q knockin mice. We then established transgenic mice (PLP-150Q) that selectively express mutant huntingtin in oligodendrocytes.

Musashi-1 maintains blood-testis barrier structure during spermatogenesis and regulates stress granule formation upon heat stress.

In mouse testes, Musashi-1 (Msi-1) was predominantly expressed in the cytoplasm and nuclei of Sertoli cells. Here we demonstrate that knockdown of Msi-1 in Sertoli cells altered the levels and distribution of blood-testis barrier (BTB)-associated proteins. Moreover, Msi-1 knockdown in vivo disrupted BTB functional structure and spermatogenesis.

Cellular expression profile of RhoA in rats with spinal cord injury.

RhoA, a small GTPase, is involved in a wide array of cellular functions in the central nervous system, such as cell motility, cytoskeleton rearrangement, transcriptional regulation, phagocytosis and cell growth. It is not known how spinal cord injury (SCI) affects the expression of RhoA in different nerve cells. In the present study, we investigated the changes of RhoA expression in remote areas of the injury at the 3rd, 7th and 30th day after SCI, which was established by T10 contusion method.

Inhibition of cardiomyocytes differentiation of mouse embryonic stem cells by CD38/cADPR/Ca2+ signaling pathway.

Cyclic adenosine diphosphoribose (cADPR) is an endogenous Ca(2+) mobilizing messenger that is formed by ADP-ribosyl cyclases from nicotinamide adenine dinucleotide (NAD). The main ADP-ribosyl cyclase in mammals is CD38, a multi-functional enzyme and a type II membrane protein. Here we explored the role of CD38-cADPR-Ca(2+) in the cardiomyogenesis of mouse embryonic stem (ES) cells.

Tris[4-chloro-2-(2-furylmethyl-imino-meth-yl)phenolato-κO,N]iron(III).

The title complex, [Fe(C(12)H(9)ClNO(2))(3)], is a mononuclear Schiff base iron(III) compound. The Fe atom is six-coordinated by three phenolic O and three imine N atoms from three Schiff base ligands in an octa-hedral geometry.

[Comparison of long- term efficacy between preoperative radiotherapy or radiochemotherapy followed by lower-anterior resection and Miles abdominoperineal resection in patients with low rectal cancer].

Objective: To compare the long-term efficiency between preoperative radiotherapy or radiochemotherapy followed by lower-anterior resection and abdominoperineal resection (APR) for lower and locally advanced rectal cancer.

Methods: From January 1983 to December 2000, 157 consecutive patients suffering from lower rectal cancer were enrolled in the study, which included 69 cases of clinical stage II and 88 cases of stage III respectively. All patients were divided in to three groups.