Broadly Applicable Strategy for the Fluorescence Based Detection and Differentiation of Glutathione and Cysteine/Homocysteine: Demonstration in Vitro and in Vivo.

Glutathione (GSH), cysteine (Cys), and homocysteine (Hcy) are small biomolecular thiols that are present in all cells and extracellular fluids of healthy mammals. It is well-known that each plays a separate, critically important role in human physiology and that abnormal levels of each are predictive of a variety of different disease states. Although a number of fluorescence-based methods have been developed that can detect biomolecules that contain sulfhydryl moieties, few are able to differentiate between GSH and Cys/Hcy. In this report, we demonstrate a broadly applicable approach for the design of fluorescent probes that can achieve this goal. The strategy we employ is to conjugate a fluorescence-quenching 7-nitro-2,1,3-benzoxadiazole (NBD) moiety to a selected fluorophore (Dye) through a sulfhydryl-labile ether linkage to afford nonfluorescent NBD-O-Dye. In the presence of GSH or Cys/Hcy, the ether bond is cleaved with the concomitant generation of both a nonfluorescent NBD-S-R derivative and a fluorescent dye having a characteristic intense emission band (B1). In the special case of Cys/Hcy, the NBD-S-Cys/Hcy cleavage product can undergo a further, rapid, intramolecular Smiles rearrangement to form a new, highly fluorescent NBD-N-Cys/Hcy compound (band B2); because of geometrical constraints, the GSH derived NBD-S-GSH derivative cannot undergo a Smiles rearrangement. Thus, the presence of a single B1 or double B1 + B2 signature can be used to detect and differentiate GSH from Cys/Hcy, respectively. We demonstrate the broad applicability of our approach by including in our studies members of the Flavone, Bodipy, and Coumarin dye families. Particularly, single excitation wavelength could be applied for the probe NBD-OF in the detection of GSH over Cys/Hcy in both aqueous solution and living cells.

Job-related factors associated with tobacco use among Chinese food delivery riders: A cross-sectional survey.

INTRODUCTION: Food delivery drivers represent a rapidly growing occupational group in China in recent years. Their unique work patterns such as a complex work environment and high time-pressure may subject them to more severe tobacco use issues compared to other professions. This study aims to investigate the prevalence of tobacco use within this group and examine the underlying reasons behind it. METHODS: A cross-sectional, multistage sampling design was conducted to select 1879 food delivery riders from Guangzhou and Shenzhen. A self-administered questionnaire was used to collect the data from August to December 2022. Chi-squared analysis and binary logistic regression analysis, adjusted for factors including gender, education level, type of employment, alcohol use, job-related uncertainty stress, and emotional exhaustion, were used to explore the key factors associated with smoking among this occupational group. RESULTS: Altogether, 65.5% of individuals in this sample were smokers, with 69.5% among males and 26.2% among females. Factors found to be significantly associated with smoking behavior were male sex (AOR=5.48; 95% CI: 3.74-8.02), education level of junior high school or lower (AOR=1.60; 95% CI: 1.21-2.11), education level of senior high school (AOR=1.52; 95% CI: 1.18-1.95), full-time job (AOR=1.39; 95% CI: 1.18-1.80), alcohol use (AOR=3.91; 95% CI: 3.14-4.87), moderate level of job-related uncertainty stress (AOR=0.58; 95% CI: 0.42-0.81), high level of emotional exhaustion (AOR=1.57; 95% CI: 1.17-2.10) and moderate level of emotional exhaustion (AOR=1.52; 95% CI: 1.00-2.30). CONCLUSIONS: Demographic factors like gender, education level, job type, and substance use should be considered in designing smoking cessation campaigns for this group. Improving work conditions, reducing emotional exhaustion, and managing stress may also reduce smoking and enhance the well-being of these riders.

Learning Visual Affordance Grounding From Demonstration Videos.

Visual affordance grounding aims to segment all possible interaction regions between people and objects from an image/video, which benefits many applications, such as robot grasping and action recognition. Prevailing methods predominantly depend on the appearance feature of the objects to segment each region of the image, which encounters the following two problems: 1) there are multiple possible regions in an object that people interact with and 2) there are multiple possible human interactions in the same object region. To address these problems, we propose a hand-aided affordance grounding network (HAG-Net) that leverages the aided clues provided by the position and action of the hand in demonstration videos to eliminate the multiple possibilities and better locate the interaction regions in the object. Specifically, HAG-Net adopts a dual-branch structure to process the demonstration video and object image data. For the video branch, we introduce hand-aided attention to enhance the region around the hand in each video frame and then use the long short-term memory (LSTM) network to aggregate the action features. For the object branch, we introduce a semantic enhancement module (SEM) to make the network focus on different parts of the object according to the action classes and utilize a distillation loss to align the output features of the object branch with that of the video branch and transfer the knowledge in the video branch to the object branch. Quantitative and qualitative evaluations on two challenging datasets show that our method has achieved state-of-the-art results for affordance grounding. The source code is available at: https://github.com/lhc1224/HAG-Net.

Red-emitting boron difluoride complexes with a mega-large Stokes shift and unexpectedly high fluorescence quantum yield.

Introduction of a tetrahydroquinoxaline donor into boron difluoride complexes largely extended their emissions (617-684 nm), highly improved their fluorescence quantum yields (up to 0.68) and greatly increased their Stokes shifts (up to 209 nm). These new fluorescent dyes showed reversible ratiometric solid-state fluorescence changes upon switched acid/base fumings. Significantly, these boron difluoride complexes were successfully utilized as imaging agents in living cells and zebrafish.