Time-restricted feeding protects against cisplatin-induced acute kidney injury in mice.

Background: Time-restricted feeding (TRF), devoid of calorie restriction, is acknowledged for promoting metabolic health and mitigating various chronic metabolic diseases. While TRF exhibits widespread benefits across multiple tissues, there is limited exploration into its impact on kidney function. In this study, our aim was to investigate the potential ameliorative effects of TRF on kidney damage in a mouse model of cisplatin-induced acute kidney injury (AKI). Methods: Cisplatin-induced AKI was induced through intraperitoneal injection of cisplatin into C57BL/6 male mice. Mice undergoing TRF were provided unrestricted access to standard chow daily but were confined to an 8-hour feeding window during the dark cycle for 2 weeks before cisplatin injection. The mice were categorized into four groups: control, TRF, cisplatin, and TRF + cisplatin. Results: The tubular damage score and serum creatinine levels were significantly lower in the TRF + cisplatin group compared to the cisplatin group. The TRF + cisplatin group exhibited reduced expression of phosphorylated nuclear factor kappa B, inflammatory cytokines, and F4/80-positive macrophages compared to the cisplatin group. Furthermore, oxidative stress markers for DNA, protein, and lipid were markedly decreased in the TRF + cisplatin group compared to the cisplatin group. TUNEL-positive tubular cells, cleaved caspase-3 expression, and the Bax/Bcl-2 ratio in the TRF + cisplatin group were lower than those in the cisplatin group. Conclusion: TRF, without calorie restriction, effectively mitigated kidney damage by suppressing inflammatory reactions, oxidative stress, and tubular apoptosis in a mouse model of cisplatin-induced AKI. TRF holds promise as a novel dietary intervention for preventing cisplatin-induced AKI.

Association between smoking cessation and obstructive spirometry pattern among Korean adults aged 40-79 years.

Smoking cessation aids in restoring lung function. However, whether long-term cessation can fully restore lung function has not been studied thoroughly, especially in Asian countries. This study aimed to evaluate the association between smoking cessation status and obstructive spirometry pattern among Koreans aged 40-79 years. In total, 6298 men and 8088 women aged 40-79 years from the Korea National Health and Nutrition Examination Survey (2015-2019) were analyzed for smoking cessation status, including the duration after quitting. Current-smokers showed a higher likelihood of having an obstructive spirometry pattern than never-smokers among both men (odds ratio [OR]: 3.15, 95% confidence interval [CI]: 2.32-4.29) and women (OR: 2.60, 95% CI: 1.59-4.23). In men, the effect tended to decrease with longer duration after cessation, but male ex-smokers who had quit smoking ≥ 20 years ago still showed a higher likelihood of having an obstructive spirometry pattern than male never-smokers (OR: 1.40, 95% CI: 1.05-1.89). In female ex-smokers, there was no significant association with the obstructive spirometry pattern, compared to that in female never-smokers. This study emphasizes the benefits of smoking cessation, possibility of long-lasting harm to lung function due to tobacco smoking, and importance of smoking prevention.

Effects of Seed Layer Coating and Oxygen Plasma Treatment on the Growth of ZnO Nanorods for UV Photodetector Applications.

Dark current in optical sensors has been one of their issues. The performance of these sensors can be improved by reducing their dark current. In this study, we investigated UV sensors based on ZnO nanorods (ZNRs), in particular, their current-voltage characteristics, response and recovery times, on-off current ratio, and responsivity as a function of the device process conditions. The number of seed layer coatings was changed and an oxygen (O2) plasma treatment was applied to ZNRs. A microwave-assisted growth (MAG) method was used to grow ZNRs. The MAG method is one way to shorten device manufacturing time. The small number of seed layer coating processes played a role in reducing the dark current of the sensor. The O2 plasma treatment further reduced the dark current. The crystal quality of ZNRs was affected by changes in the sensor fabrication process. Although the O2 plasma treated device had an increased on-off current ratio, the response time was increased.

Combustible Gas Classification Modeling using Support Vector Machine and Pairing Plot Scheme.

Combustible gases, such as CH4 and CO, directly or indirectly affect the human body. Thus, leakage detection of combustible gases is essential for various industrial sites and daily life. Many types of gas sensors are used to identify these combustible gases, but since gas sensors generally have low selectivity among gases, coupling issues often arise which adversely affect gas detection accuracy. To solve this problem, we built a decoupling algorithm with different gas sensors using a machine learning algorithm. Commercially available semiconductor sensors were employed to detect CH4 and CO, and then support vector machine (SVM) applied as a supervised learning algorithm for gas classification. We also introduced a pairing plot scheme to more effectively classify gas type. The proposed model classified CH4 and CO gases 100% correctly at all levels above the minimum concentration the gas sensors could detect. Consequently, SVM with pairing plot is a memory efficient and promising method for more accurate gas classification.

Operational Characteristics of Various AlGaN/GaN High Electron Mobility Transistor Structures Concerning Self-Heating Effect.

This study investigated DC characteristics of AlGaN/GaN high electron mobility transistors (HEMTs) considering self-heating effect (SHE) with basic T-gate (BT), drain-side extended T-gate (DSET), and source-bridge FP (SBFP) structures. We analyzed threshold voltage, transconductance, drain saturation current, and breakdown voltage of each structure for device optimization. Experimental data were initially matched with simulated data for the BT structure, then DC characteristics were compared with the drift-diffusion, coupled drift-diffusion and self-heating models for basic T-gate HEMT devices. Breakdown voltages were measured to identify the optimum DSET structure length, while increasing drain-side gate head to 3 µm. An SBFP was also employed where the DSET device showed highest breakdown voltage. Therefore, DC characteristics were compared for three structures and contrasted to reduce SHE. Hot spot and overall temperature were also analyzed for each structure.

Thermal Analysis and Operational Characteristics of an AlGaN/GaN High Electron Mobility Transistor with Copper-Filled Structures: A Simulation Study.

In this study, we investigated the operational characteristics of AlGaN/GaN high electron mobility transistors (HEMTs) by applying the copper-filled trench and via structures for improved heat dissipation. Therefore, we used a basic T-gate HEMT device to construct the thermal structures. To identify the heat flow across the device structure, a thermal conductivity model and the heat transfer properties corresponding to the GaN, SiC, and Cu materials were applied. Initially, we simulated the direct current (DC) characteristics of a basic GaN on SiC HEMT to confirm the self-heating effect on AlGaN/GaN HEMT. Then, to verify the heat sink effect of the copper-filled thermal structures, we compared the DC characteristics such as the threshold voltage, transconductance, saturation current, and breakdown voltage. Finally, we estimated and compared the lattice temperature of a two-dimensional electron gas channel, the vertical lattice temperature near the drain-side gate head edge, and the transient thermal analysis for the copper-filled thermal trench and via structures. Through this study, we could optimize the operational characteristics of the device by applying an effective heat dissipation structure to the AlGaN/GaN HEMT.

DC Characteristics of AlGaN/GaN High-Electron Mobility Transistor with a Bottom Plate Connected to Source-Bridged Field Plate Structure.

We investigate DC characteristics of AlGaN/GaN high-electron mobility transistors by using a source-bridged field plate and additional bottom plate (BP) structure. The analysis of experimental data was performed with a two-dimensional simulator. Source connected BP structure stabilized threshold voltage and transconductance regardless of various drain voltages. The effect of BP location was also analyzed, which had optimal DC values because of the dependence of breakdown voltage and drain current of the device on BP position between gate and drain. Finally, the optimum distance of 0.8 µm from drain side gate head edge to BP was achieved for optimum DC characteristics and the highest breakdown voltage of 341 V.