Enhancing Efficiency in Carbon Nanotube Electrode-Based Perovskite Solar Cells through Interface and Thickness Optimization

Gao Shan Shan(고산산),Seong Sik Shin(신성식) 한국태양에너지학회 2024 한국태양에너지학회 학술대회논문집 Vol.2024 No.4

Compact Band Notched Slot Antenna for Ultra-Wideband (UWB) Applications Based on Strong Couplings Slots

Shan Shan Gao,Jia-Lin Li,Hui Min Qiao 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.5

A planar slot antenna operating at 2.75–9.75 GHz is studied for ultra-wideband (UWB) applications, where three controllable notched bands centered at 4, 5.9 and 8.45 GHz are further introduced to avoid some potential interferences. The elliptical slots and coplanar waveguide feeding lines are incorporated to achieve desired UWB operation. By introducing a V-shaped and two U-shaped slots on the CPW signal line, three notched bands are implemented, and each notch band can be adjusted independently. Measurements on the developed demonstrator match with the numerical simulations.

Contact toxicity and transcriptomic analysis of terpinen-4-ol exposure in Tribolium castaneum

Shan-shan Gao,Yong-lei Zhang,Kun-peng Zhang,Wang Xing-yun,Qing-bo Tang,Yuan-chen Zhang 한국응용곤충학회 2022 Journal of Asia-Pacific Entomology Vol.25 No.3

The terpene, terpinen-4-ol (T4ol), exhibits contact toxicity in Tribolium castaneum. However, the molecular mechanisms underlying this toxicity have not been elucidated. This study examined changes in the expression of four classic enzymes after exposure of T. castaneum to T4ol. Acetylcholinesterase and glutathione S-transferase activities were markedly inhibited after exposure to T4ol, while that of the detoxifying enzyme cytochrome oxidase P450 increased markedly. Carboxylesterase activity did not show significant changes. Furthermore, RNA sequencing revealed 260 differentially expressed genes (DEG) between the T4ol-treated and control samples, and qRT-PCR was used to validate the RNA-Seq data. The Gene Ontology analysis classified the DEGs into 36 functional groups, including the immune system processes, response to stimulus, and developmental processes. T4ol altered the response to stimulus and the immune system process of beetles by inducing the expression of the genes Stabilin-1, Attacin 1, and Defensin 1. Furthermore, the DEGs receptor tyrosine kinase Torso-like protein (RTKTsl), Frizzled 4 (Fz4), Protein Wnt-5b, Ecdysone-induced protein 78C (E78), Zinc finger protein GLIS1 (ZFPGLIS1) were classified as participating in beetle development, and Fz4 and Protein Wnt-5b also mapped to the Wnt signaling pathway. This indicated that pathways associated with development are inhibited after exposure to T4ol. T4ol also induced CYP9Z6/GSTs7 overexpression, and RNAi targeting these genes significantly increased larvae mortality on T4ol exposure, supporting the participation of CYP9Z6/GSTs7 in the response to T4ol in T. castaneum. The results of this study will facilitate understanding of the toxic mechanisms of T4ol and provide a basis for controlling the pests of stored products.

Compact Dual-Mode Balun Bandpass Filter with Improved Out-of-Band Performance

Gao Shan Shan,Yi Gang Yu,Sun Sheng 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.4

A compact dual-mode balun bandpass fi lter with improved out-of-band performance is proposed based on a ring resonator. In order to excite the two degenerate modes and obtain fi ltering balun performance, three parallel-coupled lines are placed at three excitation ports along the ring resonator. By properly arranging the angles between the excitation arms, four transmission zeros can be realized to improve stopband performance. Finally, a prototype of the designed balun bandpass fi lter is implemented and fabricated. The measured results show a good agreement with those obtained from the simulation, thus verifying our proposal with good in-band fi ltering and out-of-band performance.

A sigma class glutathione S-transferase gene regulated by the CncC pathway is required for phytochemical tolerance in the red flour beetle, Tribolium castaneum

Gao Shan-shan,Li Dong-yu,Huo Zhuang-kun,Zhang Yong-lei,Cao Yi-zhuo,Tan Yue-yao,Guo Xin-long,Zhang Jia-hao,Zhang Kun-peng,Li Rui-min 한국응용곤충학회 2022 Journal of Asia-Pacific Entomology Vol.25 No.4

Insect glutathione S-transferases (GSTs) play a crucial role in the detoxification of exogenous compounds, especially insecticides and plant allelochemicals. A sigma class GST gene, TcGSTS7, mediates the response to eugenol in Tribolium castaneum. However, the mechanism underlying this effect remains largely unknown. In this study, TcGSTS7, which exhibits a structural motif and domain organization characteristic of GSTs, was cloned from the T. castaneum genome. Spatiotemporal expression analysis revealed that TcGSTS7 was most highly expressed at the late larva stage and was mainly expressed in the fat body and epidermis of larvae and adults, suggesting that TcGSTS7 may play a potential role in the protection against toxic xenobiotics in T. castaneum. Furthermore, the expression of TcGSTS7 was significantly induced after exposure to eugenol, while RNA inter ference (RNAi) targeting TcGSTS7 enhanced the sensitivity of the beetle to eugenol, indicating that TcGSTS7 is involved in the tolerance of T. castaneum to this insecticide. Interestingly, the depletion of TcCncC, which encodes a transcription factor of the CncC pathway that has been associated with the regulation of detoxification-related genes in insects, led to a reduction in the TcGSTS7 transcript level following exposure to eugenol, which suggests that TcGSTS7 acts downstream of the CncC pathway. Combined, these results indicated that TcGSTS7 partici pates in the tolerance of T. castaneum to phytochemicals in a CncC pathway-dependent manner. These findings have implications for the development of novel drugs for use in pest control.

Actions and mechanisms of reactive oxygen species and antioxidative system in semen

Shan Gao,Chunjin Li,Lu Chen,Xu Zhou,X. Zhou 대한독성 유전단백체 학회 2017 Molecular & cellular toxicology Vol.13 No.2

Oxidative stress caused by the production of reactive oxygen species (ROS) in excess of the defense capability of the body’s antioxidative system is one of the primary reasons of sperm dysfunction. ROS, including free radicals, oxygen ions, and peroxides, are by-products of normal cellular metabolism. These molecules are important in physiological processes and cellular signaling pathways. Moderate amounts of ROS are indispensable for sperm physiology, such as capacitation, hyperactivation, and sperm-egg fusion. However, relatively high level of ROS can disrupt the integrity of sperm DNA and limit the fertilizing potential because of the compromised lipids and proteins in the sperm membrane. The antioxidative system of semen is composed of enzymatic and non-enzymatic antioxidants which interact with each other to maintain an intricate balance between ROS production and scavenging system. This review highlights the mechanisms of ROS production and elimination as well as the physiological and pathological effects on spermatozoa.

Oxidative stress increases the risk of pancreatic <i>β</i> cell damage in chronic renal hypertensive rats

Gao, Shan,Park, Byung M.,Cha, Seung A.,Bae, Ui J.,Park, Byung H.,Park, Woo H.,Kim, Suhn H. John Wiley and Sons Inc. 2016 Physiological reports Vol.4 No.16

<P><B>Abstract</B></P><P>Hypertension often occurs in conjunction with insulin resistance. The purpose of this study was to evaluate whether sustained renal hypertension increases the risk of diabetes mellitus in rats, and to define the underlying mechanisms. Two‐kidney, one‐clip hypertensive (2K1C) rats received captopril (50 mg/kg/day), <I>α</I>‐lipoic acid (100 mg/kg/day), or vehicle treatment for 3 months after surgery. Blood pressure was measured by tail cuff plethysmography. Oral glucose tolerance test (OGTT), immunohistochemistry, and western blotting were performed. In addition, insulin secretion from islet cells was measured. OGTT yielded abnormal results, and the number of islet cells and the size of pancreatic <I>β</I>/<I>α</I> cells were decreased in 2K1C rats. Basal insulin levels were also reduced in the plasma. Insulin secretion from pancreatic islet cells in response to high glucose was also attenuated in 2K1C rats compared with sham rats. The levels of oxidative stress markers, including 8‐hydroxydeoxyguanosine and NADPH oxidase‐4, were increased in pancreatic tissue and pancreatic islets in 2K1C rats. The abnormalities observed in 2K1C rats were improved by captopril or <I>α</I>‐lipoic acid treatment. These findings indicate that sustained renal hypertension may lead to pancreatic dysfunction, increasing oxidative stress in pancreatic islets.</P>

Progressive Collapse Analysis of 20-storey Building Considering Composite Action of Floor Slab

Shan Gao,Lanhui Guo 한국강구조학회 2015 International Journal of Steel Structures Vol.15 No.2

Until now, the prototypes for finite element modeling are usually practice buildings or designed by researchers themselves which means there is no uniform standard for evaluation and comparison of progressive collapse analysis results. In this paper, using software Abaqus, a 3-D model of 20-storey building considering composite action of floor slab is developed to simulate and evaluate the behavior of high-rise composite building under sudden column failure. The methodology for the modeling techniques which could improve the computational efficiency is validated by the results from a progressive collapse test. The 20-storey benchmark building considering composite action of floor slab designed to meet American seismic code has adequate load paths and redundancy to resist the spread of local collapse due to sudden column removal. The column failure in where the column size changes does not influence the behavior of structures too much. The results of progressive collapse analysis adopting 20-storey benchmark model provide important information for standardization design to prevent progressive collapse.

Urotensin II receptor antagonist attenuates monocrotaline-induced cardiac hypertrophy in rats

Gao, Shan,Oh, Young-Bin,Shah, Amin,Park, Woo Hyun,Chung, Myoung Ja,Lee, Young-Ho,Kim, Suhn Hee American Physiological Society 2010 American journal of physiology, Heart and circulat Vol.299 No.6

<P> Urotensin II (UII) is a vasoactive peptide with potent cardiovascular effects through a G protein-coupled receptor. Hypoxia stimulates the secretion of UII and atrial natriuretic peptide (ANP). However, the effect of UII on hypoxia-induced cardiac hypertrophy is still controversial. The present study was conducted to determine whether human UII (hUII)-mediated ANP secretion influences hypoxia-induced cardiac hypertrophy using in vitro and in vivo models. Hypoxia caused an increase in ANP secretion and a decrease in atrial contractility in isolated perfused beating rat atria. hUII (0.01 and 0.1 nM) attenuated hypoxia-induced ANP secretion without changing the atrial contractility, and the hUII effect was mediated by the UII receptor signaling involving phospholipase C, inositol 1,3,4 trisphosphate receptor, and protein kinase C. Rats treated with monocrotaline (MCT, 60 mg/kg) showed right ventricular hypertrophy with increases in pulmonary arterial pressure and its diameter and plasma levels of UII and ANP that were attenuated by the pretreatment with an UII receptor antagonist, urantide. An acute administration of hUII (5 μM injection plus 2.5 μM infusion for 15 min) decreased the plasma ANP level in MCT-treated rats but increased the plasma ANP level in MCT plus urantide-treated and sham-operated rats. These results suggest that hUII may deteriorate MCT-induced cardiac hypertrophy mainly through a vasoconstriction of the pulmonary artery and partly through the suppression of ANP secretion. </P>

Development of an Ultra-Slim System in Package (SiP)

Gao, Shan,Hong, Ju-Pyo,Kim, Jin-Su,Yoo, Do-Jae,Jeong, Tae-Sung,Choi, Seog-Moon,Yi, Sung The Korean Microelectronics and Packaging Society 2008 마이크로전자 및 패키징학회지 Vol.15 No.1

This paper reviews the current development of an ultra-slim SiP for Radio Frequency (RF) application, in which three flip chips, additional passive components and Surface Acoustic Wave (SAW) filters are integrated side-by-side. A systematic investigation is carried out for the design optimization, process and reliability improvement of the package, which comprises several aspects: a design study based on the 3D thermo-mechanical finite element analysis of the packaging, the determination of stress, warpage distribution, critical failure zones, and the figuration of the effects of material properties, process conditions on the reliability of package. The optimized material sets for manufacturing process were determined which can reduce the number of testing samples from 75 to 2. In addition the molded underfilling (MUF) process is proposed which not only saves one manufacturing process, but also improves the thermo-mechanical performance of the package compared with conventional epoxy underfilling process. In the end, JEDEC's moisture sensitivity test, thermal cycle test and pressure cooker tests have also been carried out for reliability evaluation. The test results show that the optimized ultra-slim SiP has a good reliability performance.