Modulating Triplet Excited States of Organic Semiconductors via Tuning Molecular Conformation for Dual-ratiometric Thermometers.

The dual-ratiometric thermometry is one of highly accurate methods for microscopic thermal measurement in biological systems. Herein, a series of chromone derivatives with noncovalently intramolecular interactions (NIIs) were designed and synthesized for ratiometric thermometers. The triplet states of these organic compounds were systematically tuned upon regulating the conformation with NIIs to yield efficient room temperature phosphorescence and large wavelength difference between fluorescence and phosphorescence simultaneously. As a result, an unprecedent organic 3D dual-ratiometric thermometer was established based on the intensity ratio and lifetime ratio of fluorescence/phosphorescence vs temperature, which was used for in vitro and in vivo bio-thermometry with high accuracy. This work provides a novel method to achieve organic dual ratiometric thermometers via tuning the triplet excited states.

Er-Based Luminescent Nanothermometer to Explore the Real-Time Temperature of Cells under External Stimuli.

Temperature as a typical parameter, which influences the status of living creatures, is essential to life activities and indicates the initial cellular activities. In recent years, the rapid development of nanotechnology provides a new tool for studying temperature variation at the micro- or nano-scales. In this study, an important phenomenon is observed at the cell level using luminescent probes to explore intracellular temperature changes, based on Yb-Er doping nanoparticles with special upconversion readout mode and intensity ratio signals (I525 and I545 ). Further optimization of this four-layer core-shell ratio nanothermometer endows it with remarkable characteristics: super photostability, sensitivity, and protection owing to the shell. Thus this kind of thermal probe has the property of anti-interference to the complex chemical environment, responding exclusively to temperature, when it is used in liquid and cells to reflect external temperature changes at the nanoscale. The intracellular temperature of living RAW and CAOV3 cells are observed to have a resistance mechanism to external stimuli and approach a more favorable temperature, especially for CAOV3 cells with good heat resistance, with the intracellular temperature 4.8 °C higher than incubated medium under 5 °C environment, and 4.4 °C lower than the medium under 60 °C environment.

Coumarin-based fluorescent probes toward viscosity in mitochondrion/lysosome.

Viscosity is an important microenvironmental indicator that plays an important role in the process of information transmission in various regions. Herein, two coumarin-based viscosity-sensitive fluorescent probes (CHB, CHN) were synthesized and the photophysical properties of the two probes were studied. The fluorescence quantum yields of CHB and CHN in glycerol can be as high as 25.2% and 18.3% respectively. The two probes can linearly detect viscosity in the viscosity logarithm range of 0.83-2.07, which is not interfered with pH, metal ions, anions and biomolecules. Fluorescent confocal cell experiments show CHB and CHN have good targeting ability to mitochondrion, lysosome, Endoplasmic reticulum and Golgi apparatus, and can be used to detect viscosity in mitochondrion/lysosome.

Alcohol Exposure and Disease Associations: A Mendelian Randomization and Meta-Analysis on Weekly Consumption and Problematic Drinking.

Alcohol consumption significantly impacts disease burden and has been linked to various diseases in observational studies. However, comprehensive meta-analyses using Mendelian randomization (MR) to examine drinking patterns are limited. We aimed to evaluate the health risks of alcohol use by integrating findings from MR studies. A thorough search was conducted for MR studies focused on alcohol exposure. We utilized two sets of instrumental variables-alcohol consumption and problematic alcohol use-and summary statistics from the FinnGen consortium R9 release to perform de novo MR analyses. Our meta-analysis encompassed 64 published and 151 de novo MR analyses across 76 distinct primary outcomes. Results show that a genetic predisposition to alcohol consumption, independent of smoking, significantly correlates with a decreased risk of Parkinson's disease, prostate hyperplasia, and rheumatoid arthritis. It was also associated with an increased risk of chronic pancreatitis, colorectal cancer, and head and neck cancers. Additionally, a genetic predisposition to problematic alcohol use is strongly associated with increased risks of alcoholic liver disease, cirrhosis, both acute and chronic pancreatitis, and pneumonia. Evidence from our MR study supports the notion that alcohol consumption and problematic alcohol use are causally associated with a range of diseases, predominantly by increasing the risk.

Tunable Afterglow System via Controllable Photoenergy Storage and Release.

Afterglow luminescence has garnered significant attention due to its excellent optical properties. Currently, most afterglow phenomena are produced by persistent luminescence following cessation of the excitation light. However, it remains a challenge to control the afterglow luminescence process due to rapid photophysical or photochemical changes. Here, we develop a new strategy to control the afterglow luminescence process by introducing pyridones as singlet oxygen (1O2) storage reagents (OSRs), where 1O2 can be stored in covalent bonds at relatively low temperatures and released upon heating. The afterglow luminescence properties, including afterglow intensity, decay rate, and decay process, can be tuned flexibly by regulating temperature or OSR structures. Based on the controllable luminescence properties, we devise a new strategy for information security. We believe that such an excellent luminescent system also holds remarkable potential for applications in many other fields.

Green Tea Polyphenols Alleviate Hydrogen Peroxide-Induced Oxidative Stress, Inflammation, and Apoptosis in Bovine Mammary Epithelial Cells by Activating ERK1/2-NFE2L2-HMOX1 Pathways.

Oxidative stress (OS) is one of the main limiting factors affecting the length of lactation and milk quality in dairy cows. For high-producing dairy cows, the OS of mammary glands is a serious problem. Green tea polyphenols (GTP), found mainly in tea, are a combination of many phenols. GTP have a good effect on antioxidation, inflammation resistance, obesity, fat cell metabolism improvement, and lowering of blood lipid. Therefore, we studied the role of GTP on OS in dairy cows and further investigated whether GTP alleviates oxidative damage of bovine mammary epithelial cells (BMECs) induced by hydrogen peroxide (H2O2) and its underlying molecular mechanism. In this study, 500 µM of H2O2 for 12 h incubation was chosen as the condition of the OS model of BMECs. In addition, the present results found that treatment with GTP alleviated the oxidative damage induced by H2O2 [the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) were significantly increased, and the contents of malondialdehyde (MDA), 8-isoprostaglandin (8-iso-PG), 8-oxo-deoxyguanosine (8-OHdG), and protein carbonyl (PC) and caspase-3 and caspase-9 activities were significantly reduced]. These effects are related to the activation of the erythrocyte-derived nuclear factor 2-like protein 2 (NFE2L2) signaling pathway and the inactivation of the caspase/Bcl-2 apoptotic pathway. When NFE2L2 short interfering RNA (siRNA) was used to downregulate the expression of NFE2L2 in cultured BMECs, NFE2L2-siRNA transfection abolished the protective effect of GTP on H2O2-induced intracellular reactive oxygen species (ROS) accumulation and apoptosis. In addition, the mitogen-activated protein kinase (MAPK) inhibition test further proved that GTP relieved H2O2-induced oxidative damage by activating the NFE2L2 signaling pathway, which was achieved by activating the extracellular-regulated kinase 1/2 (ERK1/2) signaling pathway. Overall, the results indicate that GTP has a beneficial effect on the redox balance of BMECs. In addition, GTP might be a latent antioxidant in vivo, which can be administered to ruminants during stressful periods such as the perinatal period.