检索结果-南通市图书馆

Surface plasmon enhancement of photoluminescence in photo-chemically synthesized graphene quantum dot and Au nanosphere

引用

Nano Research 2016年第6期9卷 1866-1875页

作者： Byeongho park Sun jun Kim Ji Soo Sohn Min Sik Nam Shinill Kang Seong Chan jun School of Mechanical Engineering Yonsei University 50 Yonsei-ro Seodaemun-gu Seou1120-749 Republic of Korea

Graphene quantum dots （GQDs） are promising candidates for potential applications such as novel optoelectronic devices and bio-imaging. However, insufficient light absorption to exhibit their intriguing characteristics. The strong confinement of light caused by the Au nanoparticles as an antenna can considerably boost the light absorption. With the assistance of ultraviolet irradiation, we prepared bluish-green luminescent nanospheres by the hybridiza- tion of GQD and Au nanoparticles （GQD/Au）. These nanospheres showed a photoluminescence quantum yield of up to 26.9%. The GQD/Au nanospheres were synthesized using a solution of GQDs and HAuC14 by a photochemical method with the reduction of GQDs and the formation of metallic Au. The GQDs and Au nanopartides self-assembled and aggregated into nanospheres via aurophilicity and hydrogen bonding interactions. The average size of the GQD/Au nanospheres was found to be in the range of 150-170 nm, which is much larger than that of the pristine GQDs （4-7 nm）. The GQD/Au nanospheres exhibited an absorption band at 541 nm, which indicates the presence of Au in the nanospheres. The typical absorbance features of GQDs were observed near 236 and 303 nrn. The photoluminescence characteristics were investigated using the excitation and emission spectra. The GQD/Au nanospheres exhibited two emission peaks at 468 and 529 nm in the visible range. The green fluorescent peak located at 529 nm was newly generated by the hybridization. The GQD/Au nanospheres showed an emission efficiency which was two times more than that of the intrinsic GQDs. The reason for this increase was the surface plasmon resonance from the Au particles, which improved the fluorescence property of the resulting nanospheres. These nanospheres can be perceived as outstanding candidates for applications such as displays, optoelectronic devices, and imaging of the biological samples with high emission intensity.

关键词： graphene quantum dot gold nanosphere photoluminescence UV irradiation

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Serum cytokine levels in chronic hepatitis B patients receiving peginterferon alpha-2a therapy

引用

Hepatobiliary & Pancreatic Diseases International 2012年第5期11卷 499-506页

作者： Yongjung park jun Yong park Kwang-Hyub Han Hyon-Suk Kim Department of Laboratory Medicine Yonsei University College of Medicine Department of Internal Medicine Institute of GastroenterologyYonsei University College of Medicine

BACKGROUND: The relationship between cytokines and responses to peginterferon α-2a treatment in chronic hepatitis B patients has not yet been fully elucidated. We analyzed the serum levels of interleukin (IL)-1α, IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, vascular endothelial growth factor, interferon-γ, tumor necrosis factor-α, monocyte chemotactic protein-1 (MCP1) and epidermal growth factor during the treatment with peginterferon α-2a. METHODS: Ninety-three serum samples from 20 chronic hepatitis B patients were collected before, during and after 48 weeks of peginterferon therapy and were assayed for 12 cytokines. The patients were categorized as either virologic responders (VRs) or non-responders (NRs) according to their HBV DNA levels taken at 6th month during treatment. The Evidence Investigator (Randox, Antrim, UK), a protein chip analyzer, was used to quantify cytokines. RESULTS: Among the 12 cytokines, the levels of MCP1 were increased and the levels of IL-4 were decreased during the treatment in VRs. However these cytokines were not significantly changed in NRs in the treatment phases. Area under the receiver operating characteristic curve (AUROC) value of HBV DNA measured before the treatment was 0.81 in predicting VRs, and that of the baseline MCP1 was 0.76. IL-6 levels at 3rd and 6th months during the treatment also showed AUROC values 0.85 and 0.78 respectively in predicting sustained VRs. CONCLUSION: Serum cytokine levels reflect the pathological differences of individual treatment phases and could also be useful in monitoring responses to peginterferon treatment in chronic hepatitis B patients.

关键词： chronic hepatitis B cytokine hepatitis B virus peginterferon protein chip array

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Polysaccharide from Astragalus membranaceus promotes the activation of human peripheral blood and mouse spleen dendritic cells

引用

Chinese Journal of Natural Medicines 2021年第1期19卷 56-62页

作者： Lim Seong-Min park Hae-Bin Jin jun-O Department of Medical Biotechnology Yeungnam UniversityGyeongsan 38541South Korea Shanghai Public Health Clinical Center Shanghai Medical CollegeFudan UniversityShanghai201508China

Astragalus membranaceus(***)is a widely used traditional herb in China and *** polysaccharides(AMP),which make up a major part of the root extract,have been shown to modulate immune modulations,especially activation of bone marrow-derived dendritic cells(BMDCs)and T ***,the immune stimulatory effect of AMP in the mouse in vivo and human peripheral blood DCs(PBDCs)has not been well *** this study,we found that intravenous(i.v.)injection of AMP in C57 BL/6 mice induced remarkable elevations in co-stimulatory and MHC class I and II molecule levels in the splenic DCs and its *** stimulatory effect of DCs by AMP was elevated 6 h after treatment,which rapidly decreased 18 h after ***,AMP promoted intracellular production of pro-inflammatory cytokines in spleen DC subsets,which contributed elevation of serum cytokine ***,the AMP promoted PBDC ***,these results demonstrate that AMP can be used as an immune stimulatory molecules in human and mouse.

关键词： Astragalus membranaceus polysaccharide Spleen dendritic cell Human peripheral blood dendritic cell

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

High-concentration dispersions of exfoliated MoS2 sheets stabilized by freeze-dried silk fibroin powder

引用

Nano Research 2016年第6期9卷 1709-1722页

作者： HeungBo Sim JiYong Lee Byeongho park Sun jun Kirn Shinill Kang ,WonHyoung Ryu Seong Chan jun School of Mechanical Engineering Yonsei University Seoul 120-749 Republic of Korea

Liquid-phase exfoliation （LPE） is an attractive method for the scaling-up of exfoliated MoS2 sheets compared to chemical vapor deposition and mechanical cleavage. However, the MoS2 nanosheet yield from LPE is too small for practical applications. We report a facile method for the scaling-up of exfoliated MoS2 nanosheets using freeze-dried silk fibroin powders. Compared to MoS2 dispersion in the absence of silk fibroin powder, sonicated MoS2 dispersions with silk fibroin powder （MoSJSilk dispersion） show noticeably higher exfoliated MoS2 nanosheet yields, with suspended MoS2 concentrations in MoS2/Silk dispersions sonicated for 2 and 5 h of 1.03 and 1.39 ***-1, respectively. The MoS2 concentration in the MoS2/Silk dispersion after centrifugation above 10,000 rpm is more than four times that without the silk fibroin. The size of the dispersed silk fibroin is controlled by the change of centrifugation rate, showing the removal of silk fibroin above tens of micrometers in size after centrifugation at 2,000 rpm. Size-controlled silk fibroin biomolecules combined with MoS2 nanosheets are expected to increase the practical use of such materials in fields related to tissue engineering, biosensors and electrochemical electrodes. Atomic force microscopy and Raman spectroscopy provide the height of the MoS2 nanosheets spin-cast from MoS2/Silk dispersions, showing thicknesses of 3--6 nm. X-ray photoelectron spectroscopy and X-ray diffraction indicate that the outermost surface layer of the hydrophobic MoS2 crystals interact with oxygen-containing functional groups that exist in the hydrophobic part of silk fibroins. The amphiphilic properties of silk fibroin combined with the MoS2 nanosheets stabilize dispersions by enhancing solvent-material interactions. The large quantities of exfoliated MoS2 nanosheets suspended in the as-synthesized dispersions can be utilized for the fabrication of vapor and electrochemical devices requiring high MoS2 nanosheets contents.

关键词： MoS2 nanosheet liquid-phase exfoliation freeze-dried silk fibroin powder amount of suspended MoB2 sheet stabilized dispersion

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Multi-Agent Deep Reinforcement Learning-Based Resource Allocation in HPC/AI Converged Cluster

引用

Computers, Materials & Continua 2022年第9期72卷 4375-4395页

作者： Jargalsaikhan Narantuya jun-Sik Shin Sun park JongWon Kim Department of Cloud Kakao Enterprise CorpSeongnam13494Korea AI Graduate School Gwangju Institute of Science and Technology(GIST)Gwangju61005Korea

As the complexity of deep learning(DL)networks and training data grows enormously,methods that scale with computation are becoming the future of artificial intelligence(AI)*** this regard,the interplay between machine learning(ML)and high-performance computing(HPC)is an innovative paradigm to speed up the efficiency of AI research and ***,building and operating an HPC/AI converged system require broad knowledge to leverage the latest computing,networking,and storage ***,an HPC-based AI computing environment needs an appropriate resource allocation and monitoring strategy to efficiently utilize the system *** this regard,we introduce a technique for building and operating a high-performance AI-computing environment with the latest ***,an HPC/AI converged system is configured inside Gwangju Institute of Science and Technology(GIST),called GIST AI-X computing cluster,which is built by leveraging the latest Nvidia DGX servers,high-performance storage and networking devices,and various open source ***,it can be a good reference for building a small or middlesized HPC/AI converged system for research and educational *** addition,we propose a resource allocation method for DL jobs to efficiently utilize the computing resources with multi-agent deep reinforcement learning(mDRL).Through extensive simulations and experiments,we validate that the proposed mDRL algorithm can help the HPC/AI converged cluster to achieve both system utilization and power consumption *** deploying the proposed resource allocation method to the system,total job completion time is reduced by around 20%and inefficient power consumption is reduced by around 40%.

关键词： Deep learning HPC/AI converged cluster reinforcement learning

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Regular moderate aerobic exercise improves high-fat diet-induced nonalcoholic fatty liver disease via monoacylglycerol O-acyltransferase 1 pathway suppression

引用

Journal of Sport and Health Science 2020年第5期9卷 472-478页

作者： Kyung-Wan Baek Jeong-An Gim jung-jun park Division of Sport Science Pusan National UniversityBusan 46241Korea Department of Biological Sciences College of Natural SciencesPusan National UniversityBusan 46241Korea

Purpose:Monoacylglycerol O-acyltransferase 1(MGAT1)is reported to play a key role in the development of diet-induced nonalcoholic fatty liver disease(NAFLD).Thus,this study investigated the effect of exercise on suppression of the MGAT1 pathway in NAFLD tissue of high-fat diet(HFD)-induced obese ***:Male Sprague-Dawley rats were fed an HFD containing 45%fat for 6 *** confirmation that NAFLD had been induced in the obese animals,they were divided into HFD-fed groups provided with exercise(HFD+EXE)or without exercise(HFD)and a group given dietary adjustment(DA)only,for a further 6 weeks of intervention *** 6-week regular moderate aerobic exercise consisted of an accommodation phase with increasing *** accumulation in the liver tissue was determined by Oil Red O *** MGAT1 and liver lipogenic gene mRNA levels were measured by qPCR,and their protein levels by western blot ***:Oil Red O staining showed that NAFLD was successfully induced by *** gene expression of MGAT1 was significantly lower in HFD+EXE than ***,there was no significant difference between HFD+EXE and *** protein expression of MGAT1 was significantly lower in HFD+EXE than both HFD and *** RNA and protein expression of other lipogenic genes were not different among *** data indicate that exercise suppresses MGAT1 pathway regardless of HFD feeding;in part,this effect could be greater than ***:Our data suggest that exercise can improve NAFLD,which is probably due to suppression of MGAT1 pathway.

关键词： Exercise High-fat diet Monoacylglycerol O-acyltransferase 1 Nonalcoholic fatty liver disease Obesity

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Free radical scavenger effect of rebamipide in sperm processing and cryopreservation

引用

Asian Journal of Andrology 2003年第3期5卷 195-201页

作者： Nam Cheol park Hyun jun park Kyeong Mi Lee Dong Gil Shin Department of Urology College of Medicine Pusan National University Busan 602 739 KoreaDepartment of Urology College of Medicine Pusan National University Busan 602 739 KoreaDepartment of Urology College of Medicine Pusan National University Busan 602 739 KoreaDepartment of Urology College of Medicine Pusan National University Busan 602 739 Korea

Aim: To study the effect of rebamipide added to semen samples and cryoprotectant on reactive oxygen species (ROS) production. Methods: Semen samples from 30 fertile and healthy volunteers were collected by masturbation after 2 days - 3 days of abstinence. After liquefaction, the specimens were diluted with sperm wash media to a uniform density of 20×106/mL. Rebamipide was added to semen samples and cryoprotectant to a final concentration of 10 μmol/L, 30 μmol/L, 100 μmol/L or 300 μmol/L. Specimens were incubated at 37 ℃ in a 0.5 % CO2 incubator for 1 h or cryopreserved at -196 ℃ LN2 for 3 days. The sperm motility and viability and the levels of ROS and lipid peroxidation of sperm membrance were assessed before and after incubation and cryopreservation by means of computer assisted semen analyzer, eosin-nigrosin stain, chemiluminescence and thiobarbituric acid assay, respectively. Results: The sperm motility was significantly increased after incubation with 100 μmol/L and 300 μmol/L rebamipide (P0.05). The levels of ROS and lipid peroxidation in semen were significantly decreased in proportion to the concentrations of rebamipide both after incubation and cryopreservation (P<0.05). Conclusion: Rebamipide is an effective free radical scavenger in semen in vitro.

关键词： male infertility reactive oxygen species rebamipide

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

以建设成效为导向的海绵城市评价体系研究

引用

中国给水排水 2024年第4期40卷 13-18页

作者：陈俊宇厦门市城市规划设计研究院有限公司福建厦门361012

落实海绵城市理念的优质建设项目能够产生示范效应,有助于推动海绵设施质量不断提升。基于管控制度、设施功能、设施外观、示范效应四项因素,以建设成效为导向,采用层次分析法,构建了基于建设项目尺度的海绵城市评价体系。评价结果表明... 详细信息

落实海绵城市理念的优质建设项目能够产生示范效应,有助于推动海绵设施质量不断提升。基于管控制度、设施功能、设施外观、示范效应四项因素,以建设成效为导向,采用层次分析法,构建了基于建设项目尺度的海绵城市评价体系。评价结果表明,现阶段建设项目尺度上的海绵城市建设,在设计变更管控、运维制度建立方面存在欠缺,普遍存在竖向控制不够精细以及设计、施工中各专业衔接配合不足、景观营造与海绵设施功能不够融合等问题,除公园类项目外,其他各类项目在理念宣传、共同缔造方面有待提升。

关键词：海绵城市建设成效评价体系层次分析法

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Fingerprint inspired advanced end-effector and its applications

引用

Friction 2022年第10期10卷 1739-1750页

作者： Sung Ho LEE Hyo Sung KIM Han jun park Moon Kyu KWAK Department of Electrical Engineering and Computer Science University of MichiganAnn Arbor 48109USA Department of Mechanical Engineering Kyungpook National UniversityDaegu 41566Republic of Korea

The human fingertip consists of a fingerprint with many micro-grating *** main roles of the fingerprint could be divided into two purposes,namely,the enhancement of the frictional force and the effective transmittance of the *** this study,we present the fingerprint-inspired end-effector that has not only admirable frictional force but also electric *** end-effector is composed of fluorocarbon rubber,one of the famous materials to achieve high frictional force and *** various experiments,the novel performance of micro structured fluorocarbon rubber end-effector(MSFE)is characterized by comparing with a macroscale patterned sample(MPS),which has been already used in real industrial *** results are analyzed ***,as feasible applications,we suggest two applications based on the role of the *** is the conductive astronaut glove with high frictional force,and the other one is a non-slip pad for the next-generation glass transfer *** these experiments,we successfully observe the enhanced system performance and confirm the possibility of using the MSFE as feasible *** believe that the MSFE could be a useful and powerful alternative as an end-effector,not only in the aerospace industry but also in display manufacturing processes.

关键词： fingerprint end-effector fluorocarbon rubber(FKM) glass transfer system spacesuit

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Self-expandable metal stents for choledocholithiasis in Billroth II gastrectomy patients

引用

Hepatobiliary & Pancreatic Diseases International 2018年第6期17卷 546-552页

作者： Min-Gui Han Eunae Cho Chang-Hwan park Chung-Hwan jun Seon-Young park Division of Gastroenterology Department of Internal MedicineChonnam National University Hospital42Jaebong-roDong-KuGwangju 61482Korea

Background: Efficient ampullary intervention is essential for endoscopic retrograde cholangiopancreatography(ERCP) in patients with a prior Billroth II gastrectomy. We retrospectively evaluated the safety and effectiveness of ampullary intervention using fully covered self-expandable metal stents(FCSEMSs) for the management of common bile duct(CBD) stones in a subset of patients with a history of Billroth II gastrectomy. Methods: This retrospective analysis involved patients with a prior Billroth II gastrectomy who underwent ampullary intervention with FCSEMSs for the management of CBD stones. The factors associated with FCSEMSs placement, treatment success, and procedural complications were analyzed. Results: A group of 15 patients(10 males; median age, 78 years) underwent biliary metal stent placement for high degree of CBD angulation(6), small or flat papilla with unclear margin(5), current use of double antiplatelet agents or an anticoagulant(2), unwanted instrumentation of the cystic duct(1), and insecure position of the scope(1). Ampullary intervention with FCSEMSs was successful in all patients. After dilating the ampulla of Vater and building a durable conduit with FCSEMSs immediately, CBD stones were removed successfully from all patients in a single session. A mild post-ERCP pancreatitis occurred in one patient, who recovered without complications. Conclusion: Ampullary intervention with FCSEMSs is safe and effective for the management of CBD stones in a subset of patients with a history of Billroth II gastrectomy.

关键词： Common bile duct stone Endoscopic retrograde cholangiopancreatography Stent placement Stone extraction

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：