Publications by authors named "Qiumei Chen"

BACKGROUND Patients with urolithiasis often undergo transurethral ureteroscopic holmium laser lithotripsy, a procedure that can be affected by perioperative thermal management. This study examines the impact of compound thermal insulation management on patient recovery and comfort during transurethral ureteroscopic holmium laser lithotripsy. MATERIAL AND METHODS In this study, 551 patients who underwent transurethral ureteroscopic holmium laser lithotripsy from April 2019 to December 2022 were randomly assigned to either an observation group (n=276) or control group (n=275).

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Extracting polyphenolic bioactive compounds from Pinus elliottii needles, a forestry residue, promises economic and environmental benefits, however, relevant experimental data are lacking. Herein, a comprehensive investigation of the polyphenolic composition of pine needles (PNs) was carried out. Ultrasound-Assisted Extraction (UAE) was applied to extract the polyphenolic compounds of pine needles.

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Okra pod is sensitive to low temperature, which results in chilling injury under improper low-temperature storage. This study aimed to evaluate the effect of different concentrations of methyl jasmonate (MeJA) treatment on okra pod stored at 4 ± 1°C for 12 days and illuminate the mechanism of MeJA alleviating chilling injury. Compared to the control, MeJA treatments maintained lower relative electric conductivity (REC), chilling injury (CI) degree, and lignin content, as well as higher total soluble solids, total soluble sugar, pectin content, and chlorophyll content.

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Bound solitons have become a hot topic in the field of nonlinear optics due to their potential applications in optical communication, information processing and radar systems. However, the trapping of the cascaded bound soliton is still a major challenge up to now. Here, we propose and experimentally demonstrate a multi-pulse bound soliton fiber laser based on MoTe saturable absorber.

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Background: Circulating angiogenic cells (CACs) are peripheral blood cells whose functional capacity inversely correlates with cardiovascular risk and that have therapeutic benefits in animal models of cardiovascular disease. However, donor age and disease state influence the efficacy of autologous cell therapy. We sought to determine whether age or coronary artery disease (CAD) impairs the therapeutic potential of CACs for myocardial infarction (MI) and whether the use of ex vivo gene therapy to overexpress endothelial nitric oxide (NO) synthase (eNOS) overcomes these defects.

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The zinc tetrathiolate (ZnS4) cluster is an important structural feature of endothelial nitric oxide synthase (eNOS). The cluster is located on the dimeric interface and four cysteine residues (C94 and C99 from two adjacent subunits) form a cluster with a Zn ion in the center of a tetrahedral configuration. Due to its high sensitivity to oxidants this cluster is responsible for eNOS dimer destabilization during periods of redox stress.

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Introduction: We sought to determine the effects of brief exposures to low concentrations of tobacco secondhand smoke (SHS) on arterial flow-mediated dilation (FMD, a nitric oxide-dependent measure of vascular endothelial function), in a controlled animal model never before exposed to smoke. In humans, SHS exposure for 30 min impairs FMD. It is important to gain a better understanding of the acute effects of exposure to SHS at low concentrations and for brief periods of time.

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Nitric oxide (NO) exerts a wide range of cellular effects in the cardiovascular system. NO is short lived, but S-nitrosoglutathione (GSNO) functions as a stable intracellular bioavailable NO pool. Accordingly, increased levels can facilitate NO-mediated processes, and conversely, catabolism of GSNO by the regulatory enzyme GSNO reductase (GSNOR) can impair these processes.

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Background: Chronic or severe acute elevations in plasma glucose are associated with decreases in the number and function of circulating angiogenic cells (CACs). However, less is known about whether fasting plasma glucose levels (FPG) within the normal or pre-diabetic range among healthy individuals are associated with decreased CAC function. Establishing this relationship is an important step in developing a line of research that may ultimately lead to preventative lifestyle interventions intended to maximize endogenous CAC function and reduce cardiometabolic disease risk.

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Objective: Circulating angiogenic cells (CACs), also termed endothelial progenitor cells, play an integral role in vascular repair and are functionally impaired in coronary artery disease (CAD). The role of nitric oxide (NO) in CAC function is poorly understood. We hypothesized that CAC migration toward angiogenic signals is modulated by both NO synthase (NOS) expression and functional response to NO.

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The frequency of intrinsic pulsatile GnRH secretion from endogenous GnRH neurons and GT1 GnRH cell lines is stimulated by increased intracellular cAMP levels. The downstream molecules comprising the cAMP signaling pathway are organized in microdomains by a family of scaffolding proteins, A-kinase anchoring proteins (AKAPs). These molecules tether protein kinase A, cAMP-specific phosphodiesterases, phosphatases to known substrates.

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In humans, endothelial vasodilator function serves as a surrogate marker for cardiovascular health and is measured as changes in conduit artery diameter after temporary ischemia [flow-mediated dilation (FMD)]. Here we present an FMD-related approach to study femoral artery (FA) vasodilation in anesthetized rats. Diameter and Doppler flow were monitored in the FA.

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Recent studies have shown the involvement of Fas/Fas ligand (FasL) system and nitric oxide (NO) in ovarian follicle atresia. Here we asked whether Fas/Fas ligand system interacts with NO using rat granulosa cell culture. Soluble recombinant Fas ligand (rFasL), at 100 ng/ml, significantly decreased cell viability, as measured by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt (MTS) assay, in the presence of 200 U/ml interferon-gamma, whereas the concurrent addition of a caspase inhibitor, Z-VAD-FMK, at 20 microm, significantly inhibited rFasL-induced cytotoxicity.

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