检索结果-南通市图书馆

Extraction and Purification of Depigmenting Agents from Chinese Plants

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2006年第2期22卷 162-167页

作者： AHN So-young ROW kyung-ho kim Eun-ki School of Chemical and Biological Engineering Center for Advanced Bioseparation Technology Inha University Nam-Ku Incheon 402-751 Korea

Depigmenting agents were solvent-extracted and purified by preparative and analytical HPLC from three Chinese plants; Chrysanthemum morifolium Ramat（ Xizang Caijuhua）, Rhodiola sachalinensis, and Terminalia chebula Retzius. Four fractions obtained from the ethyl ether layer of C. m. Rama and two fractions from the ethyl acetate layer of Rhodiola salientness show depigmenting effects. At 8 200, the ethyl acetate layers of Chrysanthemum morifolium Ramat, Rhodiola sachalinensis and the methanol extract of Terminalia chebula Retzius, can inhibit the melanin production of mouse B16 melanoma cells by 92%, 60% and 90%, respectively, whereas 46% inhibition was observed by commercially available depigmenting agents（arbutin）. These results show the potential of these three Chinese plants as a novel resource for depigmenting agents in the cosmetic industry.

关键词： Chrysanthemum Morifolium Ramat Rhodiola Sachalinensis Terminalia Chebula Retzius Melanin Inhibitory Effect HPLC

Expression of apoptosis-related factors in chronic cyclosporine nephrotoxicity after cyclosporine withdrawal

在线全文

学校读者我要写书评

暂无评论

Acta Pharmacologica Sinica 2004年第4期25卷 3-13页

作者： Sun-woo LIM,bo-kyung SUN,Bum-soon CHOI,Sylvia GLOWACKA,Alison J COX,Darren J KELLY,Yong-soo kim,Jin kim,Byung-kee BANG,Chul-woo YANG Departments of Internal Medicine the Catholic University of Korea Seoul137-040 Korea Departments of Internal Medicine the Catholic University of Korea Seoul137-040 Korea Departments of Internal Medicine the Catholic University of Korea Seoul137-040 Korea Department of Medicine St Vincent’s Hospital Fitzroy University of Melbourne Australia Department of Medicine St Vincent’s Hospital Fitzroy University of Melbourne Australia Department of Medicine St Vincent’s Hospital Fitzroy University of Melbourne Australia Departments of Internal Medicine the Catholic University of Korea Seoul137-040 Korea Departments of Anatomy the Catholic University of Korea Seoul137-040 Korea Departments of Internal Medicine the Catholic University of Korea Seoul137-040 Korea Departments of Internal Medicine the Catholic University of Korea Seoul137-040 Korea MD PhD

AIM: To examine whether the reversibility of chronic cyclosporine A (CsA) nephrotoxicity is associated with apoptotic cell death and its regulatory factors. METHODS: Chronic CsA nephrotoxicity was induced in Sprague- Dawley rats by administering CsA (15 mg/kg, sc) for 5 weeks, and then withdrawing it for 5 or 10 weeks. The effect of CsA withdrawal on apoptotic cell death was evaluated by an in situ TdT-mediated deoxyuridine triphos- phate-biotin nick end-labeling (TUNEL) assay and the expression of pro-apoptotic [(transforming growth factor- beta1 (TGF-β1) and Fas] and anti-apoptotic [epidermal growth factors (EGF) and Bcl-2] factors. RESULTS: Discontinuation of CsA induced significant decreases in TUNEL-positive cells in a time-dependent manner and the reduction in TUNEL-positive cells was correlated with the tubulointerstitial fibrosis score (r=0.919, P<0.01). Upregulation of TGF-β1 and Fas expression in CsA-treated rat kidneys was decreased significantly after with- drawal of CsA. In contrast, downregulated EGF and Bcl-2 expression returned to normal or supernormal levels. CONCLUSION: CsA withdrawal is associated with a decrease in apoptotic cell death and with changes in the expression of pro-apoptotic and anti-apoptotic molecules involved in renal wound repair. This may constitute one of the mechanisms underlying the reversibility of chronic CsA nephrotoxicity.

关键词： cyclosporine apoptosis bcl-2 fas epidermal growth factor transforming growth factor-beta fibrosis

Optimization of post-warranty sequential inspection for second-hand products

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2017年第4期28卷 793-800页

作者： Dae-kyung kim Jae-Hak Lim Dong Ho Park Department of Statistics Chonbuk National University Department of Management & Accounting Hanbat National University Industry Academic Cooperation Foundation Hallym University

This paper considers an optimal sequential inspection schedule for a second-hand product after that the free nonrenewable warranty is expired. The length of warranty is prespecified and during the warranty period, the product is minimally repaired by the dealer when it fails. Following the expiration of the non-renewing warranty, the product is inspected and upgraded sequentially a fixed number of times at the expenses of the *** each inspection, the failure rate of the product is reduced proportionally so that the product is upgraded. The product is assumed to deteriorate as it ages and the replacement of the product occurs when a fixed number of inspections are rendered. In addition,the intervals between two successive inspections are assumed to decrease monotonically. The main objective of this paper is to determine the optimal improvement level to upgrade the product at each inspection so that the expected maintenance cost during the life cycle of the product is minimized from the perspective of the customer. Under the given cost structures, we derive an explicit formula to obtain the expected maintenance cost incurred during the life cycle of the product and discuss the method to find the optimal level of the improvement analytically in case the failure times follow the Weibull distribution. Numerical results are analyzed to observe the impact of relevant parameters on the optimal solution.

关键词： second-hand product sequential inspection upgrade action life cycle of the product expected maintenance cost free non-renewable warranty

TinyML-Based Classification in an ECG Monitoring Embedded System

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2023年第4期75卷 1751-1764页

作者： Eunchan kim Jaehyuk kim Juyoung Park Haneul Ko Yeunwoong kyung Department of Intelligence and Information Seoul National UniversitySeoul08826Korea Nexon Korea Cop. SeongnamKyungki13487Korea Advanced CP Lab.Samsung Electronics SuwonKyungki16677Korea Department of Electronic Engineering Kyung Hee UniversityYonginKyungki17104Korea Division of Information&Communication Engineering Kongju National UniversityCheonanChungcheongnam31080Korea

Recently, the development of the Internet of Things (IoT) hasenabled continuous and personal electrocardiogram (ECG) monitoring. In theECG monitoring system, classification plays an important role because it canselect useful data (i.e., reduce the size of the dataset) and identify abnormaldata that can be used to detect the clinical diagnosis and guide furthertreatment. Since the classification requires computing capability, the ECGdata are usually delivered to the gateway or the server where the classificationis performed based on its computing resource. However, real-time ECG datatransmission continuously consumes battery and network resources, whichare expensive and limited. To mitigate this problem, this paper proposes atiny machine learning (TinyML)-based classification (i.e., TinyCES), wherethe ECG monitoring device performs the classification by itself based onthe machine-learning model, which can reduce the memory and the networkresource usages for the classification. To demonstrate the feasibility, afterwe configure the convolutional neural networks (CNN)-based model usingECG data from the Massachusetts Institute of Technology (MIT)-Beth IsraelHospital (BIH) arrhythmia and the Physikalisch Technische Bundesanstalt(PTB) diagnostic ECG databases, TinyCES is validated using the TinyMLsupportedArduino prototype. The performance results show that TinyCEScan have an approximately 97% detection ratio, which means that it has greatpotential to be a lightweight and resource-efficient ECG monitoring system.

关键词： Holter ECG arduino internet of things(IoT) TinyML

Miniaturized Twin-legged Robot with an Electromagnetic Oscillatory Actuator

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Bionic Engineering 2018年第1期15卷 106-113页

作者： Buhyun Shin Youngshik kim Jamie Paik kyung-min Lee Department of Mechanical Engineering Hanbat National University 125 Dongseodaero Yuseong-gu Daejeon 34158 Republic of Korea The Institute of Mechanical Engineering EPFL BM 4118 Station 17 1015-Lausanne Switzerland School of Mechanical Engineering Yeungnam University 280 Daehak-Ro Gyeongsan Gyeongbuk 38541 Republic of Korea

There have been many studies on the moving mechanism of micro robots, such as stick-slip, inchworm like motion, and impact drive. Novel actuators like lead zirconate titanate （PZT）, Shape Memory Alloy （SMA）, magnetostrictive materials, electromagnetic actuators, electoractive polymers, ultrasonic linear motors, and dielectric elastomers are utilized to realize the moving mechanism. The use of a conventional electromagnetic actuator is unfavorable, because of a few drawbacks, such as generation of stray magnetic fields, hard to miniaturize to the millimeter scale because of 3D integration and a scaling law, and power consumption to maintain a certain position. This research presents a micro robot that uses an electromagnetic actuator customized and developed for micro robot. The electromagnetic actuator is designed from a Brushless Direct Current （BLDC） motor to overcome the drawbacks mentioned above. The developed robot is composed of two electromagnetic actuators. The overall size of the robot is 20 mm × 11 mm× 9 mm （length × height × width） and the weight is 3 g. The developed robot is able to move bidirectionally with a maximum moving speed of 15.76 mm·s︿-1 （0.79 body-length per second）. The optimal conditions of an input signal are calculated theoretically and verified with experiments.

关键词： electromagnetic actuator oscillatory actuator bionic micro robot stick-slip brushless DC motor

How to deliver palliative care for patients with management in decompensated cirrhosis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Hepatobiliary Surgery and Nutrition 2023年第4期12卷 576-579页

作者： Beom kyung kim Department of Internal medicine Yonsei University College of MedicineSeoulRepublic of Korea Institute of Gastroenterology Yonsei University College of MedicineSeoulRepublic of Korea Yonsei Liver Center Severance HospitalSeoulRepublic of Korea

Palliative care is defined as multidisciplinary,specialized medical care that meets the needs of patients with serious illnesses and their caregivers from the standpoints of the physical,spiritual,and emotional levels(1).Nowadays,it is also considered to be one of the fundamental care programs for patients with decompensated cirrhosis,as has also been demonstrated in the field of other cancers(2).Recently,the guidance regarding“palliative care and symptom-based management in decompensated cirrhosis”had been published in 2022 by the American Association for the Study of Liver Diseases(AASLD)(3).

关键词： Palliative care decompensation cirrhosis

A GIS-Based Framework for Real-Time Debris-Flow Hazard Assessment for Expressways in Korea

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Disaster Risk Science 2016年第3期7卷 293-311页

作者： Han-Saem kim Choong-Ki Chung Sang-Rae kim kyung-Suk kim Earthquake Research Center Korea Institute of Geoscience and Mineral Resources Department of Civil and Environmental Engineering Seoul National University Department of Civil and Environmental Engineering Northwestern University Expressway and Transportation Research Institute Korea Expressway Corporation

Debris flows caused by heavy rainfall in mountain areas near expressways lead to severe social and economic losses and sometimes result in ***, the development of a real-time system for debris-flow hazard assessment is necessary to provide preliminary information for rapid decision making about evacuations or restoration measures, as well as to prevent secondary disasters caused by debris flows. Recently,various map-based approaches have been proposed using multi-attribute criteria and assessment methods for debrisflow susceptibilities. For the macrozonation of debris-flow hazard at a national scale, a simplified method such as the Korea Expressway Corporation(KEC) debris-flow hazard assessment method can be applied for systematic analysis based on geographic information systems(GIS) and monitoring networks. In this study, a GIS-based framework of real-time debris-flow hazard assessment for expressway sections is proposed based on the KEC debris-flow hazard assessment method. First, the KEC-based method was standardized in a systematic fashion using Arc GIS,enabling the objective and quantitative acquisition of various attribute datasets. The quantification of rainfall criteria also was considered. A safety management system for debris-flow hazard was developed based on the GIS platform. Finally, the method was applied and verified on three expressway sections in Korea. The grading standard for each individual influencing attribute was subsequently modified to more accurately assess the debris-flow hazards.

关键词： Debris-flow hazard Expressway management GIS Korea Real-time hazard assessment

Ex vivo relaxation effect of Cuscuta chinensis extract on rabbit corpus cavernosum

在线全文

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2013年第1期15卷 134-137页

作者： Kai Sun Chen Zhao Xiang-Feng Chen Hye-kyung kim bo-Ram Choi Yi-Ran Huang Jong-Kwan Park Department of Urology Renji Hospital Shanghai Jiao Tong University School of Medicine and Shanghai Institute of Andrology Shanghai 200127 China Department of Urology Chonbuk National University and Research Institute of Clinical Medicine and Clinical Trial Center of Medical Device of Chonbuk National University Hospital Jeonju 561-712 South Korea

The effect of Cuscuta chinensis extract on the rabbit penile corpus cavernosum （PCC） was evaluated in the present study. Penises obtained from healthy male New Zealand white rabbits （2.5-3.0 kg） were precontracted with phenylephrine （Phe, 10 pmol I^-1） and then treated with various concentrations of Cuscuta chinensis extract （1, 2, 3, 4 and 5 mg ml^-1）. The change in penile tension was recorded, and cyclic nucleotides in the PCC were measured by radioimmunoassay （RIA）. The interaction between Cuscuta chinensis and sildenafil was also evaluated. The result indicated that the PCC relaxation induced by Cuscuta chinensis extract was concentration-dependent. Pre-treatment with an nitric oxide synthase （NOS） inhibitor （No〉 nitro-L-arginine-methyl ester, L-NAME）, a guanylyl cyclase inhibitor （1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-l-one, ODQ）, or a protein kinase A inhibitor （KT 5720） did not completely inhibit the relaxation. Incubation of penile cavernous tissue with the Cuscuta chinensis extract significantly increased cyclic guanosine monophosphate （cGMP） and cyclic adenosine monophosphate （cAMP） in the PCC. Moreover, the Cuscuta chinensis extract significantly enhanced sildenafil-induced PCC relaxation. In conclusion, the Cuscuta chinensis extract exerts a relaxing effect on penile cavernous tissue in part by activating the NO-cGMP pathway, and it may improve erectile dysfunction （ED）, which does not completely respond to sildenafil citrate.

关键词： Cuscuta chinensis erectile dysfunction (ED) NO-cGMP pathway penile corpus cavernosum (PCC) sildenafil

K2Ti6O13 Nanoparticle-Loaded Porous rGO Crumples for Supercapacitors

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano-Micro Letters 2020年第1期12卷 115-123页

作者： Chongmin Lee Sun kyung kim Hankwon Chang Hee Dong Jang Department of Nanomaterials Science and Engineering University of Science and TechnologyYuseong‑guDaejeon 34113Republic of Korea Resources Utilization Research Center Korea Institute of Geoscience and Mineral ResourcesYuseong‑guDaejeon 34132Republic of Korea

One-dimensional alkali metal titanates containing potassium,sodium,and lithium are of great concern owing to their high ion mobility and high specific surface *** those titanates are combined with conductive materials such as graphene,carbon nanotube,and carbon nanofiber,they are able to be employed as efficient electrode materials for *** hexa-titanate(K2Ti6O13,KTO),in particular,has shown superior electrochemical properties compared to other alkali metal titanates because of their large lattice parameters induced by the large radius of potassium ***,we present porous rGO crumples(PGC)decorated with KTO nanoparticles(NPs)for application to *** KTO NP/PGC composites were synthesized by aerosol spray pyrolysis and post-heat *** NPs less than 10 nm in diameter were loaded onto PGCs ranging from 3 to 5μ*** porous structure of the composites was obtained by the activation of rGO by adding an excessive amount of KOH to the *** KTO NP/PGC composite electrodes fabricated at the GO/KOH/TiO2 ratio of 1:3:0.25 showed the highest performance(275 F g−1)in capacitance with different KOH concentrations and cycling stability(83%)after 2000 cycles at a current density of 1 A g−1.

关键词： Potassium hexa-titanate Porous graphene crumples Supercapacitors