Oxymetholone and methasterone are anabolic androgenic steroids prohibited by the World Anti-Doping Agency (WADA) for both in-competition and out-of-competition use. Detecting metabolites of exogenous steroids is crucial for establishing doping violations, making the study of these metabolites essential in antidoping efforts. This study investigated the urinary metabolic profiles of oxymetholone and methasterone using gas chromatography-orbitrap high-resolution mass spectrometry (GC-Orbitrap-HRMS) in nanogram level by utilizing a novel multiplex nontargeted framework protocol.
View Article and Find Full Text PDFRationale: Stanozolol, an anabolic androgenic steroid listed in Part S1 of the World Anti-Doping Agency Prohibited List, exhibits a low response and significant matrix interference in urine samples when using liquid-liquid extraction-gas chromatography-mass spectrometry (GC-MS). Enhancing sample preparation techniques remains essential for the effective detection of stanozolol and its metabolites.
Methods: A method for determining stanozolol and its metabolites (3'-OH-stanozolol, 4β-OH-stanozolol, and 16β-OH-stanozolol) in human urine was developed and validated using GC-Orbitrap high-resolution MS combined with optimized mixed-mode solid-phase extraction (SPE).
Unlabelled: AICAR (5-amino-4-imidazolecarboxyamide ribonucleoside), as a metabolic modulator, is classified in the S4 category by the World Anti-Doping Agency (WADA). Carbon Isotope Ratio Mass Spectrometry (CIR) is the mainstream method for distinguishing the endogenous and exogenous sources of AICAR in urine due to the significant individual difference in the concentration. The purpose of this study is to establish a gas chromatography combustion Isotope Ratio Mass Spectrometry (GC/C/IRMS) method for AICAR based on efficient two-dimensional liquid chromatography (2D-HPLC) separation.
View Article and Find Full Text PDFDesigning suitable anion exchange ionomers is critical to improving the performance and in situ durability of anion exchange membrane water electrolyzers (AEMWEs) as one of the promising devices for producing green hydrogen. Herein, highly gas-permeable and dimensionally stable anion exchange ionomers (QC6xBA and QC6xPA) are developed, in which bulky cyclohexyl (C6) groups are introduced into the polymer backbones. QC6BA-2.
View Article and Find Full Text PDFOver the past few decades, anabolic androgenic steroids (AASs) have been abused in and out of competition for their performance-enhancing and muscle-building properties. Traditionally, AASs were commonly detected using gas chromatography-mass spectrometry in the initial testing procedure for doping control purposes. Gas chromatography-Orbitrap high-resolution mass spectrometry (GC-Orbitrap-HRMS) is a new technology that has many advantages in comparison with GC-MS (e.
View Article and Find Full Text PDFThe rhizotoxicity of protons (H+) in acidic soils is a fundamental constraint that results in serious yield losses. However, the mechanisms underlying H+-mediated inhibition of root growth are poorly understood. In this study, we revealed that H+-induced root growth inhibition in Arabidopsis depends considerably on excessive iron deposition in the root apoplast.
View Article and Find Full Text PDFThe design and development of efficient catalysts for electrochemical nitrogen reduction reaction (ENRR) under ambient conditions are critical for the alternative ammonia (NH ) synthesis from N and H O, wherein iron-based electrocatalysts exhibit outstanding NH formation rate and Faradaic efficiency (FE). Here, the synthesis of porous and positively charged iron oxyhydroxide nanosheets by using layered ferrous hydroxide as a starting precursor, which undergoes topochemical oxidation, partial dehydrogenated reaction, and final delamination, is reported. As the electrocatalyst of ENRR, the obtained nanosheets with a monolayer thickness and 10-nm mesopores display exceptional NH yield rate (28.
View Article and Find Full Text PDFComput Methods Programs Biomed
April 2023
Background And Objectives: Compressed sensing (CS) is often used to accelerate magnetic resonance image (MRI) reconstruction from undersampled k-space data. A novelty deeply unfolded networks (DUNs) based method, designed by unfolding a traditional CS-MRI optimization algorithm into deep networks, can provide significantly faster reconstruction speeds than traditional CS-MRI methods while improving image quality.
Methods: In this paper, we propose a High-Throughput Fast Iterative Shrinkage Thresholding Network (HFIST-Net) for reconstructing MR images from sparse measurements by combining traditional model-based CS techniques and data-driven deep learning methods.
Two-dimensional (2D) black phosphorus (BP) has been reported to have appealing semiconducting properties as the sensing channel in field-effect transistor (FET) sensors. However, the intrinsic instability of BP in water greatly hinders its application, and little is known about its sensing performance and mechanism in aqueous medium. Herein, a water-stable BP FET sensor for antibiotic detection is reported.
View Article and Find Full Text PDFDisinfection byproducts (DBPs), as an emerging water pollutant, present increasing concern and risk in public health and water safety. Due to their low concentration levels and inherent similarity in molecular structures, sensitive and accurate determination of DBPs is still a challenge especially for onsite or online detection. Herein, a self-regulated fluorescent probe based on the Ag nanoprism-modified lanthanide metal-organic framework (AgNPR@EuMOF) is designed for trichloroacetic acid (TCAA) detection.
View Article and Find Full Text PDFAnion-exchange membranes (AEMs) with high conductivity are crucial for realizing next-generation energy storage and conversion systems in an alkaline environment, promising a huge advantage in cost reduction without using precious platinum group metal catalysts. Layered double hydroxide (LDH) nanosheets, exhibiting a remarkably high hydroxide ion (OH) conductivity approaching 10 S cm along the in-plane direction, may be regarded as an ideal candidate material for the fabrication of inorganic solid AEMs. However, two-dimensional anisotropy results in a substantially low conductivity of 10 S cm along the cross-plane direction, which poses a hurdle to achieve fast ion conduction across the membrane comprising restacked nanosheets.
View Article and Find Full Text PDFObjectives: Transauricular vagal nerve stimulation (taVNS) at 40 Hz attenuates hippocampal amyloid load in 6-month-old amyloid precursor protein/presenilin 1 (APP/PS1) transgenic mice, but it is unclear whether 40-Hz taVNS can improve cognition in these mice. Moreover, the underlying mechanisms are still unclear.
Materials And Methods: 6-month-old C57BL/6 (wild type [WT]) and APP/PS1 mice were subjected to 40-Hz taVNS.
Despite the critical need to monitor HS, a hazardous gas, in environmental and medical settings, there are currently no reliable methods for rapid and sufficiently discriminative HS detection in real-world humid environments. Herein, targeted hybridizing of TiCT MXene with Ag nanoparticles on a field-effect transistor (FET) platform has led to a step change in MXene sensing performance down to ppb levels, and enabled the very high selectivity and fast response/recovery time under room temperature for HS detection in humid conditions. For the first time, we present a novel relative humidity (RH) self-calibration strategy for the accurate detection of HS.
View Article and Find Full Text PDFNRT1.1 is the first nitrate transport protein cloned in plants and has both high- and low-affinity functions. It imports and senses nitrate, which is modulated by the phosphorylation on Thr101 (T101).
View Article and Find Full Text PDFNovel hypercross-linked β-cyclodextrin nanospheres are rapidly synthesized with 4-amino-6-hydroxy-2-mercaptopyrimidine as a cross-linker within 5 min at a low temperature of 60 °C in the open water phase, thereby radically simplifying and accelerating the conventional time-consuming and environmentally harsh synthesis of cyclodextrin-containing polymers. The nanospheres demonstrate excellent and controllable performance as alkali-responsive nanocarriers and selective adsorbents for antibiotics.
View Article and Find Full Text PDFJ Am Coll Cardiol
December 2020
Background: An increasing number of bicuspid aortic valve (BAV) patients are undergoing transcatheter aortic valve replacement (TAVR), but the risk of brain injury in diffusion-weighted magnetic resonance imaging (DW-MRI) is currently unknown.
Objectives: This study sought to evaluate the risk of brain injury in BAV patients following TAVR.
Methods: A total of 204 consecutive severe aortic stenosis patients who underwent TAVR were enrolled.
K and NO are the major forms of potassium and nitrogen that are absorbed by the roots of most terrestrial plants. In this study, we observed that a close relationship between NO and K in Arabidopsis () is mediated by NITRATE TRANSPORTER1.1 (NRT1.
View Article and Find Full Text PDFHigh mobility group box-1 (HMGB1) plays an important role in various liver injuries. In the case of acute liver injury, it leads to aseptic inflammation and other reactions, and also regulates specific cell death responses in chronic liver injury. HMGB1 has been demonstrated to be a good therapeutic target for treating liver failure.
View Article and Find Full Text PDFTransition metal and nanocarbon-based composites with high activity and stability draw great attention in electro-Fenton system for organic pollutants removal. In this study, HKUST-1-derived Cu@C nanoparticles embedded within three-dimensional reduced graphene oxide (rGO) network (denoted as 3DG/Cu@C) is synthesized through a simple strategy. The prepared catalyst shows ordered 3D porous carbon structure and Cu@C NPs are uniformly dispersed in the matrix.
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