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      • KCI등재

        Rapid Increase in Marrow Fat Content and Decrease in Marrow Perfusion in Lumbar Vertebra Following Bilateral Oophorectomy: An MR Imaging-Based Prospective Longitudinal Study

        Yi-Xiáng J Wáng,James F Griffith,Min Deng,David KW Yeung,Jing Yuan 대한영상의학회 2015 Korean Journal of Radiology Vol.16 No.1

        Bilateral oophorectomy leads to reduced bone mineral density (BMD), and reduced BMD is associated with increased marrow fat and reduced marrow perfusion. Purpose of this study was to investigate how soon these changes occur following surgical oophorectomy. Six patients who underwent hysterectomy and bilateral salpingo-oophorectomy were studied. At baseline, mean patient age was 49.5 years (range: 45–54 years). Third lumbar vertebral body BMD measurement using quantitative CT, marrow fat fraction (FF) using MR spectroscopy and marrow perfusion using dynamic contrast enhanced MRI were conducted immediately prior to surgery and at 3, 9, and 21 months after surgery. Reduced BMD, increased marrow FF, and reduced marrow perfusion occurred synchronously post-oophorectomy. There was a sharp decrease of 12.5 ± 7.2% in BMD (n = 6), a sharp increase of 92.2 ± 46.3% (n = 6) in FF, a sharp decrease of 23.6 ± 3.9% in maximum contrast enhancement (n = 5), and of 45.4 ± 7.7% for enhancement slope (n = 5) during the initial 3 months post surgery. BMD and marrow perfusion continued to decrease, and marrow FF continued to increase at a slower rate during the following 18 months. Friedman test showed a significant trend for these changes (p < 0.05). Bilateral oophorectomy leads to a rapid decrease in lumbar BMD, an increase in marrow fat content, and a decrease in marrow blood perfusion.

      • FA/Mel@ZnO nanoparticles as drug self-delivery systems for RPE protection against oxidative stress

        Yi, Caixia,Yu, Zhihai,Sun, Xin,Zheng, Xi,Yang, Shuangya,Liu, Hengchuan,Song, Yi,Huang, Xiao Techno-Press 2022 Advances in nano research Vol.13 No.1

        Drug self-delivery systems can easily realize combination drug therapy and avoid carrier-induced toxicity and immunogenicity because they do not need non-therapeutic carrier materials. So, designing appropriate drug self-delivery systems for specific diseases can settle most of the problems existing in traditional drug delivery systems. Retinal pigment epithelium is very important for the homeostasis of retina. However, it is vulnerable to oxidative damage and difficult to repair. Worse still, the antioxidants can hardly reach the retina by non-invasive administration routes due to the ocular barriers. Herein, the targeted group (folic acid) and antioxidant (melatonin) have been grafted on the surface of ZnO quantum dots to fabricate a new kind of drug self-delivery systems as a protectant via eyedrops. In this study, the negative nanoparticles with size ranging in 4~6 nm were successfully synthesized. They could easily and precisely deliver drugs to retinal pigment epithelium via eyedrops. And they realized acid degradation to controlled release of melatonin and zinc in retinal pigment epithelium cells. Consequently, the structure of retinal pigment epithelium cells were stabilized according to the expression of ZO-1 and β-catenin. Moreover, the antioxidant capacity of retinal pigment epithelium were enhanced both in health mice and photic injury mice. Therefore, such new drug self-delivery systems have great potential both in prevention and treatment of oxidative damage induced retinal diseases.

      • KCI등재

        Transarterial Chemoembolization Using Gelatin Sponges or Microspheres Plus Lipiodol-Doxorubicin versus Doxorubicin-Loaded Beads for the Treatment of Hepatocellular Carcinoma

        Yi-Sheng Liu,Ming-Ching Ou,Yi-Shan Tsai,Xi-Zhang Lin,Chien-Kuo Wang,Hong-Ming Tsai,Ming-Tsung Chuang 대한영상의학회 2015 Korean Journal of Radiology Vol.16 No.1

        To retrospectively compare treatment of hepatocellular carcinoma (HCC) with transarterial chemoembolization (TACE) using gelatin sponges or microspheres plus lipiodol-doxorubicin vs. doxorubicin-loaded drug-eluting beads (DEB). A total of 158 patients with HCC received TACE from November 2010 to November 2011 were enrolled in this study, including 64 (40.5%) received TACE with lipiodol-doxorubicin and gelatin sponges (group A), 41 (25.9%) received TACE with lipiodol-doxorubicin and microspheres (group B), and 53 (33.5%) received TACE with doxorubicin-loaded DEB (group C). Tumor response and adverse events (AEs) were evaluated. No significant difference was found at baseline among the three groups. The doxorubicin dosage in group C wassignificantly (p < 0.001) higher compared to the dose used in groups A or B (median, 50 mg vs. 31 mg or 25 mg). Significantly (p < 0.001) more patients in group C achieved complete response compared to those in groups A or B (32.1% vs. 6.3% or 2.4%). Significantly (p < 0.001) less patients in group C had progressive disease compared to those in groups A or B (34.0% vs. 57.8% or 68.3%). Minor AEs were more common in groups A and B compared to group C, with rates of 54.7%, 34.1%, and 5.7%, respectively. In patients with HCC, TACE with DEB offers better safety and efficacy profiles compared to either TACE with gelatin sponges or TACE with microspheres.

      • KCI등재
      • Research of Adaptive Fault-Tolerant Control based on T-S Fuzzy Model for EMB System

        Yi-Nan Xi 호서대학교 공업기술연구소 2014 공업기술연구 논문집 Vol.33 No.1

        In the electro mechanical brake (EMB) system, an improvement of the fault-tolerant control, like invalid protecticais of sensors and electric systems are the key problems to the development of electric vehicles. The adaptive fault-tolerant control in this paper is focus on the descriptor nonlinear system A^iich contains double time-delays and parameter uncertainties. In fault detection and estimatic»i, cxmstruct the controlled system model wliich contains multi-sensor, double time-delays and parameter uncertainties based on T-S fuzzy model, then design the observer to realize fault detection and estimation in real-time. In building the fault-tolerant control model, the first step is to choose an appropriate sliding surface, and combine the algorithm of sliding control with adaptive generic model control. Then apply the state observer to the designed sliding adaptive generic model, and build the decision model with dynamic fault reconfiguration. And the goal of this paper about the adaptive robust fault-tolerant control for the complex nonlinear controller system is achieved. Numerical SIMULINK simulation examples are given to illustrate the application and the effectiveness of the proposed design method.

      • KCI등재

        A New Method for Elimination of Zero-Sequence Voltage in Dual Three-Level Inverter Fed Open-End Winding Induction Motors

        Yi-Wen Geng,Chen-Xi Wei,Rui-Cheng Chen,Liang Wang,Jia-Bin Xu,Shuang-Cheng Hao 전력전자학회 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.1

        Due to the excessive zero-sequence voltage in dual three-level inverter fed open-end winding induction motor systems, zero-sequence circumfluence which is harmful to switching devices and insulation is then formed when operating in a single DC voltage source supplying mode. Traditionally, it is the mean value instead of instantaneous value of the zero-sequence voltage that is eliminated, through adjusting the durations of the operating vectors. A new strategy is proposed for zero-sequence voltage elimination, which utilizes unified voltage modulation and a decoupled SVPWM strategy to achieve two same-sized equivalent vectors for an angle of 120°, generated by two inverters independently. Both simulation and experimental results have verified its efficiency in the instantaneous value elimination of zero-sequence voltage.

      • KCI등재

        Exogenous Glucose Promotes Growth and Pectinase Activity of Bacillus licheniformis DY2 Through Frustrating the TCA Cycle

        Xi Du,Donghuang Wang,Di Yin,Yi Guan,Xiuyun Ye 한국생물공학회 2019 Biotechnology and Bioprocess Engineering Vol.24 No.6

        Microbial pectinases are important sources due to the ease of production and unique physicochemical properties. Here, DY2, a strain of Bacillus licheniformis, was identified from 14 strains of bacteria as a pectinaseproducing bacterium with good application potential. Optimized carbon sources of submerged fermentation led to the identification of glucose as an ideal carbon source for activity and production of P-DY2, the pectinase produced by DY2. GC-MS based metabolomics was used to explore metabolic mechanisms mediated by glucose, showing the frustrated TCA cycle is necessary to elevate the activity and production of P-DY2. Decreased activity of α-ketoglutaric dehydrogenase and succinate dehydrogenase of DY2 in glucose-treated samples supports the conclusion that P-DY2 production is the TCA cycle-independent. These results reveal a metabolic mechanism of high-activity pectinase mediated by exogenous glucose. These findings highlight the way to understand metabolic mechanisms and promote pectinase yield through metabolomics approach and metabolic modulation, respectively.

      • Toward the AI-enabled digital financial services innovation: The role of positive emotional interactions with users

        Xi Chen,Cheng Chen,Yi Cheng 한국지능정보시스템학회 2022 한국지능정보시스템학회 학술대회논문집 Vol.2022 No.6

        Purpose: Advancements in the AI-enabled technology have made the mobile and online the dominant place for launching financial services innovation. The existing literatures have revealed that online environment is easy to arouse users’ emotions and promote emotional behavior, but still lack evidence how emotions affect the use of digital financial services. This study then develops a research model and two experiments to investigate whether and how the afforance of positive emotions through AI-enabled digital financial services innovation will enhance user’s services adoption. Design/methodology/approach: This paper used a mixed-methods approach to empirically study the role of emotions on users’ adoption of digital financial services then providing the evidence to the value of positive emotions arousal through AI-enabled interaction. An convenience nonprobability sampling approach with total of 280 responses were collected to examine the model and two behavioral experiment with total of 121 and 140 participants respectively, as well as the partial least squares technique and paired sample mean t-test were utilized for data analysis. Findings: Positive emotions promote users’ intentions to continue to use digital financial services and also exert a significant positive role through the intermediary effect of trust and satisfaction(Study 1). The users’ perceptions of the value rises in the state of positive emotional arousal and perception of the risk of financial loss decreases (Study 2). The anthropomorphic artificial intelligence service assistant can effectively evoke user’s positive emotions in service recommendations, improve their willingness of adoption and value perception and reduce perceived risk(Study 3). Originality/value: Based on emotion theory and expectation confirmation theory (ECT), this study reveals that as features, positive emotions interaction help improve users’ value perception and adoption intention, also help us further understand the role of user’s emotions arousal in digital financial service This research has practical importance in terms of understanding the affordance of positive emotional interaction through AI-enabaled service is a valuable way to carry out service innovation in digital financial platform.

      • KCI등재

        Antithrombotic Effect of Fermented Ophiopogon japonicus in Thrombosis-Induced Rat Models

        Yi-Lin Zhang,Mei-Zhu Xi,최영빈,이복희 한국식품영양과학회 2017 Journal of medicinal food Vol.20 No.7

        In this study, the antithrombotic and thrombolytic ability of second fermented extract of Ophiopogon japonicus (FEOJ) was verified in thrombosis-induced rats. Thrombosis was induced by oral administration of 2% carrageenan for 4 weeks. Five experimental groups (n = 9/group) involved in the study were control group, thrombosis group, low-dose FEOJ group (2 mL/kg, low-dose Ophiopogon japonicus [LOJ]), middle-dose FEOJ group (6 mL/kg, medium-dose Ophiopogon japonicus [MOJ]), and high-dose FEOJ group (12 mL/kg, high-dose Ophiopogon japonicus [HOJ]). The clotting time (CT), bleeding time (BT), prothrombin time (PT), activated partial thromboplastin time (APTT), and fibrinogen (FBG) were assessed in blood samples, and histological studies were performed on liver and lung tissues. The results demonstrated delayed CT only in MOJ and HOJ groups and delayed BT in all FEOJ groups compared with those in thrombosis and control groups (P < .05). Similarly, APTT was significantly delayed only in MOJ and HOJ groups, and PT was significantly delayed in all FEOJ groups, compared with those in control and thrombosis groups (P < .05). Although concentrations of FBG were similar in control, thrombosis, and LOJ groups, the tendency for decreased concentration of FBG (statistically nonsignificant) in MOJ and HOJ groups has been observed. Histological examination of livers and lungs revealed that thrombosis was partially improved in FEOJ group compared with the thrombosis group. In conclusion, CT, BT, PT, and APTT were prolonged in FEOJ group more than in control and thrombosis groups, thereby, depicting antithrombotic and thrombolytic effects. However, concentration-dependent effects of FEOJ were more prominent in MOJ and HOJ groups than in the LOJ group.

      • KCI등재

        Mesenchymal Stem Cells on a Decellularized Cartilage Matrix for Cartilage Tissue Engineering

        Xi-Fu Zheng,Shi-Bi Lu,Wei-Guo Zhang,Shu-Yun Liu,Jing-Xiang Huang,Quan-Yi Guo 한국생물공학회 2011 Biotechnology and Bioprocess Engineering Vol.16 No.3

        An ideal scaffold for cartilage tissue engineering should be biomimetic in not only its biochemical composition, but also in the morphological structure of the scaffold. In this study, we fabricated a scaffold with an oriented structure using a nanofibrous articular cartilage extracellular matrix (ACECM), in which the ACECM was used to mimic the biochemical composition and oriented structure of articular cartilage. Histology analysis showed that the scaffold contained cartilage ECM (GAGs and collagen II). Scanning electron microscopy (SEM) indicated that the scaffolds were composed of nanofibers and possessed vertical microtubules. Chondrogenic differentiation-induced mesenchymal stem cells (MSCs) were seeded on the scaffold in vitro. SEM showed that MSCs proliferated well and aligned along the vertical microtubules,which mimicked the orientation of deep zone articular cartilage. A cell proliferation assay and live/dead cell staining demonstrated that the ACECM possessed good cell affinity, which favored cell adherence and proliferation. The MSCs that had been labeled with the fluorescent dye PKH26 and seeded on scaffolds were implanted into nude mice. The differentiated cells/ACECM implants formed cartilage-like tissue 4 weeks after implantation, and stained positive for collagen type II and toluidine blue. In addition,the in vivo fluorescent images verified that the MSCs in the implants were the labeled MSCs. These results demonstrated that the oriented ACECM scaffolds hold great promise for use in cartilage tissue engineering applications.

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