Green tea extract supplementation ameliorates CCl4-induced hepatic oxidative stress, fibrosis, and acute-phase protein expression in rat

Background/PurposeWe evaluated the long-term effects of green tea extract (GTE) supplementation on oxidative stress, biliary acute phase protein expression, and liver function in CCl4-induced chronic liver injury.MethodsWe evaluated the antioxidant activity of GTE in comparison with those of vitamin C, vitamin E, and β-carotene in vitro by using an ultrasensitive chemiluminescence analyzer. Chronic liver injury was induced by intraperitoneally administering carbon tetrachloride (CCl4) (1mL/kg body weight, twice weekly) to female Wistar rats for 8 weeks. The effects of low (4mg/kg body weight per day) and high (20mg/kg body weight per day) doses of intragastric GTE on CCl4-induced liver dysfunction and fibrosis were examined by measuring the bile and blood reactive oxygen species levels and biochemical parameters by using Western blot and two-dimensional polyacrylamide gel electrophoresis techniques.ResultsGTE has greater scavenging activity against O2–, H2O2, and Hypochlorous acid (HOCl) in vitro than vitamin C, vitamin E, and β-carotene do. In vivo, CCl4 markedly increased bile and blood reactive oxygen species production, lipid accumulation, number of infiltrated leukocytes, fibrosis, hepatic hydroxyproline content, and plasma alanine aminotransferase and aspartate aminotransferase activities, and reduced plasma albumin levels. Two-dimensional polyacrylamide gel electrophoresis revealed that CCl4 increased the acute-phase expression of six biliary proteins and decreased hepatic B-cell lymphoma 2 (Bcl-2), catalase, and CuZn superoxide dismutase protein expression. GTE supplementation attenuated CCl4-enhanced oxidative stress, levels of biochemical parameters, pathology, and acute-phase protein secretion, and preserved antioxidant/antiapoptotic protein expression.ConclusionGTE supplementation attenuates CCl4-induced hepatic oxidative stress, fibrosis, acute phase protein excretion, and hepatic dysfunction via the antioxidant and antiapoptotic defense mechanisms

Numerical Simulation of Epidemic Prevention and Ventilation Efficiency in Indoor Spaces with Partitions and an Air curtain

In this study, computational fluid dynamics (CFD) were used to simulate the effect of a partition and air curtain on the concentration of a pollution source in an indoor space with different ventilation configurations. First, in the partition simulation, the performances of six different ventilation configurations were compared. Based on the results obtained, air curtain simulations were then carried out. In this study, carbon dioxide was chosen as the tracer gas in all simulations, and the realizable k − ε turbulence model was selected. In the partition simulation, a front-and-back ventilation configuration with ventilation inlets/outlets near the side walls (in diagonal) showed the best performance. This configuration was adopted for the air curtain simulation so as to investigate the effect of different air inlet velocities and air curtain velocities. It was found that as the height of the partition increases, although it has a higher chance of blocking the Covid-19 virus, it lowers the ventilation efficiency, resulting in the increase of carbon dioxide concentration in the indoor space. When the partition was replaced with an air curtain, it was found that the higher the height of the air curtain, the lower the carbon dioxide concentration in the indoor space. Compared with the partition, the air curtain can reduce the carbon dioxide concentration by up to 74.6%, indicating that the introduction of the air curtain can have an improving effect on the ventilation in the indoor space

All-trans retinoic acid ameliorates glycemic control in diabetic mice via modulating pancreatic islet production of vascular endothelial growth factor-A.

Patients with type 1 diabetes mellitus are associated with impairment in vitamin A metabolism. This study evaluated whether treatment with retinoic acid, the biologically active metabolite of vitamin A, can ameliorate diabetes. All-trans retinoic acid (atRA) was used to treat streptozotocin (STZ)-induced diabetic mice which revealed atRA administration ameliorated blood glucose levels of diabetic mice. This hyperglycemic amelioration was accompanied by an increase in the amount of β cells co-expressed Pdx1 and insulin and by restoration of the vascular laminin expression. The atRA-induced production of vascular endothelial growth factor-A from the pancreatic islets was possibly the key factor that mediated the restoration of islet vascularity and recovery of β-cell mass. Furthermore, the combination of islet transplantation and atRA administration significantly rescued hyperglycemia in diabetic mice. These findings suggest that vitamin A derivatives can potentially be used as a supplementary treatment to improve diabetes management and glycemic control

Using nomogram of the Barcelona Clinic Liver Cancer system for treatment selection in patients with stage C hepatocellular carcinoma

Abstract Background The nomogram of the Barcelona Clinic Liver Cancer (BCLC) for hepatocellular carcinoma (HCC) has been used for outcome prediction. Patients with BCLC stage C HCC often undergo anti-cancer therapy against current treatment guidelines in real world practice. We aimed to use the nomogram to provide guidance on treatment selection for BCLC stage C patients. Methods A total of 1317 patients with stage C HCC were retrospectively analyzed and divided into four groups by nomogram points. One-to-one matched pairs between patients receiving different treatments were generated by the propensity score with matching model within these groups. Survival analysis was performed by Kaplan-Meier method with log-rank test. Results Patients with higher nomogram points were more often treated with targeted or supportive therapies (p  15, there was no significant difference in survival between patients receiving two different treatment strategies. Conclusions The nomogram of BCLC system is a feasible tool to help stage C HCC patients to select primary anti-cancer treatment in pursuance of better overall survival.https://deepblue.lib.umich.edu/bitstream/2027.42/142787/1/12885_2018_Article_4202.pd

Photothermal responsivity of van der Waals material-based nanomechanical resonators

Nanomechanical resonators made from van der Waals materials (vdW NMRs) provide a new tool for sensing absorbed laser power. The photothermal response of vdW NMRs, quantified from the resonant frequency shifts induced by optical absorption, is enhanced when incorporated in a Fabry-Perot (FP) interferometer. Along with the enhancement comes the dependence of the photothermal response on NMR displacement, which lacks investigation. Here, we address the knowledge gap by studying electromotively driven niobium diselenide drumheads fabricated on highly reflective substrates. We use a FP-mediated absorptive heating model to explain the measured variations of the photothermal response. The model predicts a higher magnitude and tuning range of photothermal responses on few-layer and monolayer NbSe$_{2}$ drumheads, which outperform other clamped vdW drum-type NMRs at a laser wavelength of $532\,$nm. Further analysis of the model shows that both the magnitude and tuning range of NbSe$_{2}$ drumheads scale with thickness, establishing a displacement-based framework for building bolometers using FP-mediated vdW NMRs.Comment: 7 pages, 4 figure

Receptor compaction and GTPase rearrangement drive SRP-mediated cotranslational protein translocation into the ER

The conserved signal recognition particle (SRP) cotranslationally delivers ~30% of the proteome to the eukaryotic endoplasmic reticulum (ER). The molecular mechanism by which eukaryotic SRP transitions from cargo recognition in the cytosol to protein translocation at the ER is not understood. Here, structural, biochemical, and single-molecule studies show that this transition requires multiple sequential conformational rearrangements in the targeting complex initiated by guanosine triphosphatase (GTPase)–driven compaction of the SRP receptor (SR). Disruption of these rearrangements, particularly in mutant SRP54G226E linked to severe congenital neutropenia, uncouples the SRP/SR GTPase cycle from protein translocation. Structures of targeting intermediates reveal the molecular basis of early SRP-SR recognition and emphasize the role of eukaryote-specific elements in regulating targeting. Our results provide a molecular model for the structural and functional transitions of SRP throughout the targeting cycle and show that these transitions provide important points for biological regulation that can be perturbed in genetic diseases

Fabry-Perot Interferometric Calibration of 2D Nanomechanical Plate Resonators

Displacement calibration of nanomechanical plate resonators presents a challenging task. Large nanomechanical resonator thickness reduces the amplitude of the resonator motion due to its increased spring constant and mass, and its unique reflectance. Here, we show that the plate thickness, resonator gap height, and motional amplitude of circular and elliptical drum resonators, can be determined in-situ by exploiting the fundamental interference phenomenon in Fabry-Perot cavities. The proposed calibration scheme uses optical contrasts to uncover thickness and spacer height profiles, and reuse the results to convert the photodetector signal to the displacement of drumheads that are electromotively driven in their linear regime. Calibrated frequency response and spatial mode maps enable extraction of the modal radius, effective mass, effective driving force, and Young's elastic modulus of the drumhead material. This scheme is applicable to any configuration of Fabry-Perot cavities, including plate and membrane resonators