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Study on growing thick AlGaN layer on c-plane sapphire substrate and free-standing GaN substrate

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Science China(Physics,Mechanics & Astronomy) 2012年第12期55卷 2383-2388页

作者： WANG DangHui ZHOU Hao ZHANG JinCheng XU ShengRui ZHANG LinXia MENG FanNa ai shan HAO Yue State Key Lab.of Fundamental Science on Wide Band-Gap Semiconductor Technology School of MicroelectronicsXidian UniversityXi'an 710071China School of Materials Science and Engineering of Xi'an ShiYou University Xi'an 710065China

In this study,the thick AlGaN epilayers have been grown on the c-plane sapphire substrate and the free-standing GaN substrate using low-temperature AlN nucleation layers by low-pressure metal-organic chemical vapor deposition(LPMOCVD).High resolution X-ray diffraction(HRXRD),atom force microscopy(AFM),scanning electron microscopy(SEM),photoluminescence(PL) and Raman scattering measurements have been employed to study the crystal quality,threading dislocation density,surface morphology,optical properties and phonon properties of thick AlGaN *** results indicate that AlGaN epifilms crystal quality can be improved greatly when grown on the free-standing GaN *** calculated the threading dislocation density and found that thick AlGaN epifilm grown on the free-standing GaN substrate is much lower in total threading dislocation density than that grown on the sapphire substrate,although the surface morphology is rougher than that of sapphire substrate.

关键词： metal-organic chemical vapor deposition crystal quality surface morphology AlN nucleation layer

Design of weak current measurement system and research on temperature impact

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Nuclear Science and Techniques 2024年第4期35卷 46-56页

作者： Chu-xiang Zhao San-Gang Li Rong-Rong Su Li Yang Ming-Zhe Liu Qing-Yue Xue shan Liao Zhi Zhou Qing-shan Tan xian-Guo Tuo Yi Cheng College of Nuclear Technology and Automation Engineering Chengdu University of Technology1#DongsanluErxianqiaoChengdu 610059China Applied Nuclear Technology in Geosciences Key Laboratory of Sichuan Province Chengdu University of Technology1#DongsanluErxianqiaoChengdu 610059China University of Science and Technology of China Hefei 230026China School of Physics and Electronic Engineering Sichuan University of Science and EngineeringZigong 643000China

A dedicated weak current measurement system was designed to measure the weak currents generated by the neutron ionization *** system incorporates a second-order low-pass filter circuit and the Kalman filtering algorithm to effectively filter out noise and minimize interference in the measurement *** conducted under normal temperature conditions has demonstrated the system's high precision ***,it was observed that temperature variations can affect the measurement *** were collected across temperatures ranging from -20 to 70℃,and a temperature correction model was established through linear regression fitting to address this *** feasibility of the temperature correction model was confirmed at temperatures of -5 and 40℃,where relative errors remained below 0.1% after applying the temperature *** research indicates that the designed measurement system exhibits excellent temperature adaptability and high precision,making it particularly suitable for measuring weak currents.

关键词： Weak current measurement system Neutron ionization chamber Kalman filter algorithm Temperature correction model

Effects of rhein on intestinal epithelial tight junction in IgA nephropathy

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World Journal of Gastroenterology 2013年第26期19卷 4137-4145页

作者： Sheng-Nan Peng Hui-Hong Zeng ai-xiang Fu Xiao-Wen Chen Qing-xian Zhu Graduate School Medical College of Nanchang University Department of Clinical Medicine Science and Technology School of Jiangxi Traditional Chinese Medicine College Department of Histology and Embryology Medical College of Nanchang University

aiM: To investigate the effects of rhein on intestinal epithelial tight junction proteins in rats with IgA nephropathy (IgAN). METHODS: Twenty-eight female Sprague-Dawley rats were randomly divided into four groups (7 per group): Control, IgAN, Rhein-treated, and Rheinprevented. Bovine serum albumin, lipopolysaccharide and CCl4 were used to establish the rat model of IgA nephropathy. The Rhein-treated group was given rhein from week 7 until the rats were sacrificed. The Rheinprevented group was given rhein from week 1. Animals were sacrificed at the end of week 10. We observed the changes in the intestinal epithelial tight junctions using transmission electron microscopy, and expression of intestinal epithelial tight junction proteins zona occludens protein (ZO)-1 and occludin by immunofluorescence using laser confocal microscopy. Changes in mRNA and protein expression of ZO-1 and occludin were measured by reverse transcriptase polymerase chain reaction and Western blotting. The ratio of urinary lactulose/mannitol was measured by high performance liquid chromatography (HPLC) for assessing the intestinal permeability. RESULTS: In the control group, the tight junctions lied between epithelial cells on the top of the outer side of the cell membrane, and appeared in dense dotted crystal structures, the neighboring cells were binded tightly with no significant gap, and the tight junction protein ZO-1 and occludin were evenly distributed in the intestinal epithelial cells at the top of the junction. Compared with the control group, in the IgAN group, the structure of the tight junction became obscured and the dotted crystal structures had disappeared; the fluorescence of ZO-1 and occludin was uneven and weaker (5.37 ± 1.27 vs 10.03 ± 1.96, P < 0.01; 4.23 ± 0.85 vs 12.35 ± 4.17, P < 0.01); the mRNA expression of ZO-1 and occludin decreased (0.42 ± 0.19 vs 0.92 ± 0.24, P < 0.01; 0.40 ± 0.15 vs 0.97 ± 0.25, P < 0.01); protein expression of ZO-1 and occludin was decreased (0.

关键词： Intestine Tight junction Rhein IgA nephropathy Rat

Prior transfusion of umbilical cord mesenchymal stem cells can effectively alleviate symptoms of motion sickness in mice through interleukin 10 secretion

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World Journal of Stem Cells 2021年第2期13卷 177-192页

作者： Hua-Su Zhu Dong Li Cong Li Jin-xian Huang shan-shan Chen Lan-Bo Li Qing Shi Xiu-Li Ju Department of Pediatrics Qilu HospitalCheeloo College of MedicineShandong UniversityJinan 250012Shandong ProvinceChina Stem Cell and Regenerative Medicine Research Center Qilu HospitalCheeloo College of MedicineShandong UniversityJinan 250012Shandong ProvinceChina Department of Animal Laboratory Qilu HospitalCheeloo College of MedicineShandong UniversityJinan 250012Shandong ProvinceChina Department of Pediatrics Qilu Hospital of Shandong UniversityJinan 250012Shandong ProvinceChina

BACKGROUND Motion sickness(MS)is a disease that occurs during unbalanced movement,characterized by gastrointestinal symptoms and autonomic nervous system *** clinical treatments for MS are *** evidence indicates that the levels of pro-inflammatory cytokines increase during MS and are associated with an inner ear immune *** the present study,mesenchymal stem cells(MSCs)have been shown to exert strong immunosuppressive *** To explore whether umbilical cord-derived mesenchymal stem cells(UC-MSCs)can prevent the occurrence of MS,and the underlying mechanism regulated by MSCs in a mouse model of *** A total of 144(equal numbers of males and females)5wkold BALB/c mice were randomly divided into five groups:Normal group(n=16),MS group(n=32),MSCs group(n=32),MS+MSCs group(n=32),and MS+AS101/MSCs group(n=32).The MSCs group(n=32),MS+MSCs group(n=32),and MS+AS101/MSCs group(n=32)were preventively transplanted with UC-MSCs or AS101-treated UC-MSCs(1×106 cells/mouse).Mice in the MS(n=32),MS+MSCs,and MS+AS101/MSCs groups were subjected to rotation on a centrifuge for 10 min at 8×g/min for MS model establishment on days 3,5,8,and 10 after UC-MSCs *** Morris water maze(MWM)test was used to observe the symptom of ***-linked immunosorbent assay(ELISA)and reverse transcription-quantitative polymerase chain reaction(RT-qPCR)were used to detect the levels of inflammatory cytokines in mice peripheral blood and the petrous part of the temporal bone *** blot analysis was performed to analyze the JAK2/STAT3 signaling pathway in the cochlear *** examination was performed by hematoxylin and eosin(HE)staining for conventional morphological evaluation in the petrous part of temporal bone *** The MWM test demonstrated that UC-MSCs improved the symptoms of *** MS+MSCs group was faster than the MS group on days 3 and 5(P=0.036 and P=0.002,respectively).ELISA and RT-qPCR showed that

关键词： Mesenchymal stem cell Motion sickness Inflammation Immune microenvironment Interleukin-10 JAK2/STAT3

Chidamide based combination regimen for treatment of monomorphic epitheliotropic intestinal T cell lymphoma following radical operation:Two case reports

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World Journal of Clinical Cases 2020年第7期8卷 1278-1286页

作者： Ting-Zhi Liu Yi-Jia Zheng Zhan-Wen Zhang shan-shan Li Jiao-Ting Chen ai-Hua Peng Ren-Wei Huang Department of Hematology The Sixth Affiliated Hospital of Sun Yat-Sen UniversityGuangzhou 510655Guangdong ProvinceChina Department of Nuclear Medicine The Sixth Affiliated Hospital of Sun Yat-Sen UniversityGuangzhou 510655Guangdong ProvinceChina Department of Oncology The Sixth Affiliated Hospital of Sun Yat-Sen UniversityGuangzhou 510655Guangdong ProvinceChina

BACKGROUND Monomorphic epitheliotropic intestinal T cell lymphoma(MEITL)is a rare extranodal T-cell lymphoma that has uniformly aggressive features with a poor *** standardized treatment protocols have been *** experience has demonstrated favorable outcomes with combination chemotherapy followed by autologous hematopoietic stem cell ***,many patients are unable to tolerate the *** is a new histone deacetylase inhibitor that has shown preferential efficacy in mature T-cell *** SUMMARY We herein present two cases of MEITL who were both intermediate risk according to enteropathy-associated T cell lymphoma prognostic *** one was a 61-year-old *** complained of upper abdominal pain and intermittent black stool for 2 *** examination revealed that the intestinal wall was *** received a partial excision of the small intestine.A chidamidebased combination regimen was given *** months later,he presented with recurrence in the bilateral *** passed away 15 mo after his *** two was a 35-year-old woman who complained of abdominal distention for 1 *** emission tomography/computed tomography demonstrated wall thickening of the small intestine and upper sigmoid *** perforation and septic shock occurred on the fourth day of her *** was treated by sigmoid ***-based combination therapy was then *** was recurrence-free for 6 mo until lesions were found in the bilateral brain and lived for 17 mo since her *** to historical data,chidamide seems to improve the prognosis of MEITL *** MEITL is a type of aggressive *** is a new promising approach for the treatment of MEITL.

关键词： Monomorphic epitheliotropic intestinal T cell lymphoma Histone deacetylase inhibitor Chidamide Intensive chemotherapy Stem cell transplantation Case report

Microstructural Evolution, Mechanical Properties and Thermal Stability of Gradient Structured Pure Nickel

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Acta Metallurgica Sinica(English Letters) 2019年第8期32卷 951-960页

作者： Xiao Li Bo Guan Yun-Fei Jia Yun-Chang Xin Cheng-Cheng Zhang xian-Cheng Zhang shan-Tung Tu Key Laboratory of Pressure Systems and Safety Ministry of EducationSchool of Mechanical and Power EngineeringEast China University of Science and TechnologyShanghai 200237China School of Materials Science and Engineering Chongqing UniversityChongqing 400044China AECC Commercial aircraft Engine Co.LTD Shanghai Engineering Research Center for Commercial Aircraft EngineShanghai 20110&China

The microstructural evolution of pure nickel treated by deep rolling(DR)technique with different indent depths was investigated by means of optical microscopy and transmission electron *** surface roughness,hardness and residual stress distribution along the depth from surface were ***,the DR-treated sample was annealed at temperatures from 300 to 700℃for 2 *** results reveal that dislocation movements are the fundamental mechanisms of gradient grain refinement during the DR *** increasing indent depth of the DR,the gradient microhardness on the cross section of sample significantly increases,the maximum compressive residual stress decreases,and the affecting region of residual stress *** results of thermal stability depict that the microstructure can be stable as temperature up to 300℃,and the abnormal grain growth and annealing twins are observed at 600℃.

关键词： Deep rolling Pure nickel-Microstructural evolution Mechanical properties Thermal stability

Electrodeposition of SnO_2 nanocrystalline thin film using butyl-rhodamine B as a structure-directing agent

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Chinese Chemical Letters 2010年第12期21卷 1505-1508页

作者： Jing Yang Shou Li Bai Rui xian Luo ai Fan Chen Yuan Lin Jing Bo Zhang State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical Technology Beijing 100029 China Beijing National Laboratory for Molecular Sciences Key Laboratory of Photochemistry Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China

Porous SnO2 nanocrystalline thin films were successfully electrodeposited from an oxygen-saturated acid aqueous solution of SnCl2 containing different concentrations of butyl-rhodamine B（BRhB） at 70℃.BRhB with substitute of amidocyanogen can be dissolved in the acid deposition solution,where HCl was added to suppress hydrolysis of *** it was used as a structure-directing agent to promote the crystal growth of SnO_*** formed porous morphology and tetragonal rutile crystalline structure of the electrodeposited thin films were controlled by the addition of BRhB with different amounts.

关键词： Nanocrystalline SnO2 thin film Electrodeposition Butyl-rhodamine B Structure-directing agent

Influence of grain size on the small fatigue crack initiation and propagation behaviors of a nickel-based superalloy at 650℃

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Journal of Materials Science & Technology 2019年第8期35卷 1607-1617页

作者： Xumin Zhu Congyang Gong Yun-Fei Jia Runzi Wang Chengcheng Zhang Yao Fu shan-Tung Tu xian-Cheng Zhang Key Laboratory of Pressure Systems and Safety Ministry of Education School of Mechanical and Power Engineering East China University of Science and Technology Shanghai 200237 China AECC Commercial aircraft Engine Co. LTD Shanghai Engineering Research Center for Commercial Aircraft Engine Shanghai 201108 China

GH4169 at 650℃ in atmosphere was investigated by using single edge notch tensile specimens. The number of main cracks and crack initiation mechanisms at the notch surface strongly depended on the grain size. The crack initiation life accounted for more percentages of the total fatigue life for the alloy with smaller grain size. The fatigue life generally increased with increasing crack initiation life. The small crack transited to long crack when its length reached 10 times the grain size.

关键词： Fatigue crack initiation Small crack Crack growth rate Grain size effect High temperature

Emodin and baicalein inhibit pancreatic stromal derived factor-1 expression in rats with acute pancreatitis

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Hepatobiliary & Pancreatic Diseases International 2009年第2期8卷 201-208页

作者： Li, Zong-Fang Xia, xian-Ming Huang, Chen Zhang, Shu Zhang, Jian Zhang, ai-Jun Xi An Jiao Tong Univ Sch Med Affiliated Hosp 2 Dept Surg Xian 710004 Peoples R China Xi An Jiao Tong Univ Minist Educ Key Lab Environm & Genes Related Dis Xian 710004 Peoples R China Wannan Med Coll Yijishan Hosp Dept Surg Wuhu 241001 Peoples R China

BACKGROUND: Stromal derived factor-1 (SDF-1) is an efficacious leukocyte chemoattractant, which can attract lymphocytes and mononuclear cells from bloodstream into the site of inflammation. Emodin., an anthraquinone derivative from Radix et Rhizoma Rhei, and baicalein, a flavone from Scutellaria baicalensis Georgi, both have been reported to possess anti-inflammatory activities. The expression pattern of SDF-1 in experimental acute pancreatitis (AP) and the effect of emodin or baicalein on that are not well defined. The present study aimed to investigate the effects of emodin and baicalein on pancreatic myeloperoxidase (MPO) activity (reflecting leukocyte sequestration) and cytokine production, as well as tissue SDF-1 expression in the setting of AP. METHODS: A :rat model of AP was induced by administration (of 5% sodium taurocholate through the biliopancreatic duct. The level of tumor necrosis factor-a (TNF-alpha), interleukin-6 (IL-6) and MPO in the pancreas, and serum amylase were tested by immunohistochemistry, ELISA and chromatometry. The expressions of SDF-1 alpha and SDF-1 beta were detected by real-time PCR, Western blotting, and immunohistochemistry. RESULT: Combination of emodin and baicalein significantly reduced pancreatic TNIP-alpha, IL-6 and MPO, and also inhibited pancreatic SDF-1 expression. CONCLUSIONS: The inhibition of SDF-1 expression by emodin and baicalein might contribute, in part at least, to the amelioration of pancreatic inflammation. The present study also shows benefits of simultaneous treatment of AP.

关键词： acute pancreatitis stromal derived factor-1 myeloperoxidase traditional Chinese medicine