40 results on '"Ying-Liang Wu"'
Search Results
2. Never‑in‑mitosis A‑related kinase 8, a novel target of von‑Hippel‑Lindau tumor suppressor protein, promotes gastric cancer cell proliferation
- Author
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Guang Chen, Jun Zhou, Xiao‑Fei Ding, Jie Chen, and Ying‑Liang Wu
- Subjects
0301 basic medicine ,NEK8 ,Cancer Research ,tumor progression ,urologic and male genital diseases ,03 medical and health sciences ,ubiquitin ,Von Hippel–Lindau tumor suppressor ,medicine ,Oncogene ,biology ,gastric cancer ,Cancer ,Articles ,Cell cycle ,medicine.disease ,female genital diseases and pregnancy complications ,never-in-mitosis A-related kinase 8 ,Ubiquitin ligase ,030104 developmental biology ,Oncology ,Tumor progression ,von-Hippel-Lindau tumor suppressor ,biology.protein ,Cancer research ,Proteasome inhibitor ,medicine.drug - Abstract
Previous research has revealed that the von-Hippel-Lindau tumor suppressor protein (pVHL) may downregulate never-in-mitosis A-related kinase 8 (NEK8) via hypoxia-inducible factor-α (HIF-α). The HIF-independent functions of pVHL also serve an important role in its tumor-suppressor action. In the present study, the association between pVHL and NEK8 was demonstrated in the human gastric cancer cell line, SGC-7901, indicating a direct interaction of pVHL with NEK8. Subsequently, it was reported that MG-132, a specific proteasome inhibitor, may attenuate pVHL overexpression-induced reductions in NEK8 protein expression levels. In addition, the present study revealed that pVHL may stimulate the rapid degradation of NEK8 protein and promote its ubiquitination. The association between the expression profile of NEK8 and the survival status of patients with gastric cancer was analyzed from an online database. Kaplan-Meier survival plots indicated that higher expression levels of NEK8 may lead to poor survival, as suggested by the transcriptomic data of 1,065 patients with gastric cancer. It was found that NEK8-knockdown mediated by RNA interference inhibited SGC-7901 and SNU-1 proliferation, colony formation and migration in vitro, and tumor growth in vivo. Collectively, the present study proposed that NEK8 may be a novel target of pVHL as a ubiquitin E3 ligase, and may serve a role as a potential oncoprotein in human gastric cancer.
- Published
- 2018
3. VHL loss predicts response to Aurora kinase A inhibitor in renal cell carcinoma cells
- Author
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Guang Chen, Jun Zhou, Xiao‑Fei Ding, and Ying‑Liang Wu
- Subjects
Cancer Research ,endocrine system diseases ,Cell ,Mice, Nude ,urologic and male genital diseases ,Biochemistry ,chemistry.chemical_compound ,Mice ,Cell Line, Tumor ,Genetics ,medicine ,Animals ,Humans ,neoplasms ,Molecular Biology ,Carcinoma, Renal Cell ,Protein Kinase Inhibitors ,Aurora Kinase A ,Gene knockdown ,Mice, Inbred BALB C ,Oncogene ,Chemistry ,Azepines ,Cell cycle ,Molecular medicine ,Xenograft Model Antitumor Assays ,female genital diseases and pregnancy complications ,Kidney Neoplasms ,Gene Expression Regulation, Neoplastic ,medicine.anatomical_structure ,Pyrimidines ,Oncology ,Cell culture ,Von Hippel-Lindau Tumor Suppressor Protein ,Alisertib ,Cancer research ,Molecular Medicine - Abstract
The majority of molecular targets of anticancer agents are limited to a subset of patients, and therefore identification of more specific biomarkers that can be used to improve clinical outcomes is of increasing interest. The present study showed that von Hippel‑Lindau tumor suppressor (VHL) tumor‑suppressor activity may influence the therapeutic response to Aurora kinase A (AURKA) inhibitors in human renal cell carcinoma (RCC). VHL protein (pVHL) expression was evaluated by immunoblotting in the human RCC cell lines CAKI, ACHN, 786‑O, 769‑P and A498. The anti‑tumor activities of alisertib, an AURKA‑specific chemical inhibitor, were detected by Cell Counting Kit‑8 assay in vitro and mouse xenograft model in vivo. Additionally, the VHL‑mediated anti‑tumor activity was assessed in 769‑P and CAKI cells via the loss or gain of VHL. The results revealed that VHL‑deficient 786‑O, 769‑P and A498 cells were sensitive to alisertib. By contrast, alisertib‑resistant CAKI and ACHN cells expressed the wild type VHL gene. In addition, rescue or knockdown of VHL was observed to increase or decrease alisertib anti‑proliferation activity, respectively, in RCC cells. The inverse correlation between the VHL gene expression profile and alisertib sensitivity was further confirmed in human cancer xenografts models. Taken together, these results suggested that VHL loss could potentially serve as a biomarker for predicting the efficacy of AURKA inhibitors.
- Published
- 2017
4. Research on Social Commerce basing on Social Network Analysis
- Author
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Xin Hu, Jiong-En Xiao, and Ying-liang Wu
- Subjects
Information management ,Electronic business ,Social network analysis (criminology) ,Business ,Marketing ,Social commerce - Published
- 2017
5. The scorpions of Hainan Island, China (Arachnida: Scorpiones)
- Author
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Lin Zhu, Zhiyong Di, Ying-Liang Wu, Wen-Xin Li, Hui Liu, and Zhi-Jian Cao
- Subjects
Geography ,biology ,Hemiscorpiidae ,Ecology ,Buthidae ,Fauna ,biology.organism_classification ,China - Published
- 2013
6. Study on the Safety of Mineral and Synthetic Oil Added Commonly Used Extreme Pressure Additives
- Author
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Long Long Feng, Bao Liang Li, Ying Liang Wu, Jin Jin Yue, Zhuo Jun Chen, and Zhen Ning Dai
- Subjects
chemistry.chemical_classification ,Chromatography ,Materials science ,Phosphorus ,General Engineering ,Base oil ,chemistry.chemical_element ,Acute toxicity ,chemistry.chemical_compound ,Polyol ,chemistry ,Toxicity ,medicine ,Organic chemistry ,Synthetic oil ,Lubricant ,Mineral oil ,medicine.drug - Abstract
This article use the Sulphide Isobutene (T321), Five Sufides Dialkyl(RC2540) and Star of Phosphorus(P110) as the additives,Neopentyl Polyol Ester(NPE) and mineral oil N32 as base oil. Compound above additives and base oil for the four levels. A sample: adding 4% T321 additive in NPE. B sample: adding 4% T321 additive in N32. C sample: adding 4% RC2540 additive in NPE. D sample: adding RC2540, T321 and P110 additives in NPE (all is mass fraction). The oral acute toxicity test, eye mucous stimulation test, skin hypersensitive test, soaking tail toxicity tests were conducted in above samples. The test results show that. The mineral oil, it’s not only toxic then synthetic oil but also has a poor lubricating ability compare with the same percent additive in synthetic oil. In oral acute toxicity test, eye mucous stimulation test, skin hypersensitive test, soaking tail toxicity tests, Toxic reaction of mineral N32+4%wt Sulphide Isobutene (T321) obviously from other oil samples.
- Published
- 2012
7. Effects of acute and chronic administration of MK-801 on c-Fos protein expression in mice brain regions implicated in schizophrenia with or without clozapine
- Author
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Haifeng Wang, Dai-Ying Zuo, Yue Cao, Ying-Liang Wu, and Lan Zhang
- Subjects
Male ,medicine.medical_specialty ,Psychosis ,Gene Expression ,Mice ,Internal medicine ,Cortex (anatomy) ,medicine ,Animals ,Prefrontal cortex ,Clozapine ,Biological Psychiatry ,Brain Chemistry ,Pharmacology ,business.industry ,Glutamate receptor ,Genes, fos ,medicine.disease ,Immunohistochemistry ,Dizocilpine ,Endocrinology ,medicine.anatomical_structure ,Posterior cingulate ,Schizophrenia ,NMDA receptor ,Dizocilpine Maleate ,business ,Excitatory Amino Acid Antagonists ,Proto-Oncogene Proteins c-fos ,Antipsychotic Agents ,medicine.drug - Abstract
This study investigated the effects of acute and chronic administration of the non-competitive NMDA receptor antagonists MK-801 on c-Fos protein expression in different brain regions of mice with or without clozapine. MK-801 (0.6 mg/kg) acute administration produced a significant increase in the expression of c-Fos protein in the layers III-IV of posterior cingulate and retrosplenial (PC/RS) cortex, which was consistent with the previous reports. Moreover, we presented a new finding that MK-801 (0.6 mg/kg) chronic administration for 8 days produced a significant increase of c-Fos protein expression in the PC/RS cortex, prefrontal cortex (PFC) and hypothalamus of mice. Among that, c-Fos protein expression in the PC/RS cortex of mice was most significant. Compared to acute administration, we found that MK-801 chronic administration significantly increased the expression of c-Fos protein in the PC/RS cortex, PFC and hypothalamus. Furthermore, pretreatment of mice with clozapine significantly decreased the expression of c-Fos protein induced by MK-801 acute and chronic administration. These results suggest that c-Fos protein, the marker of neuronal activation, might play an important role in the chronic pathophysiological process of schizophrenic model induced by NMDA receptor antagonist.
- Published
- 2009
8. Unique interactions between scorpion toxins and small conductance Ca(2+)-activated potassium channels
- Author
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Fan, Yang, Zong-Yun, Chen, and Ying-Liang, Wu
- Subjects
Scorpions ,Neuronal Plasticity ,Memory ,Small-Conductance Calcium-Activated Potassium Channels ,Animals ,Scorpion Venoms - Abstract
Small conductance Ca(2+)-activated potassium channels (SK channels) distributing in the nervous system play an important role in learning, memory and synaptic plasticity. Most pharmacological properties of them are determined by short-chain scorpion toxins. Different from most voltage-gated potassium channels and large-conductance Ca(2+)-activated potassium channels, SK channels are only inhibited by a small quantity of scorpion toxins. Recently, a novel peptide screener in the extracellular pore entryway of SK channels was considered as the structural basis of toxin selective recognition. In this review, we summarized the unique interactions between scorpion toxins and SK channels, which is crucial not only in deep-researching for physiological function of SK channels, but also in developing drugs for SK channel-related diseases.
- Published
- 2015
9. Effect of acute and chronic MK-801 administration on extracellular glutamate and ascorbic acid release in the prefrontal cortex of freely moving mice on line with open-field behavior
- Author
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Chun-Fu Wu, Masatoshi Tanaka, Ying-Liang Wu, Dai-Ying Zuo, Yue Cao, and Ya-Hong Zhang
- Subjects
Male ,Microdialysis ,Glutamic Acid ,Prefrontal Cortex ,Ascorbic Acid ,Motor Activity ,Pharmacology ,Drug Administration Schedule ,General Biochemistry, Genetics and Molecular Biology ,Open field ,Mice ,Animals ,General Pharmacology, Toxicology and Pharmaceutics ,Prefrontal cortex ,Behavior, Animal ,Dose-Response Relationship, Drug ,Chemistry ,Antagonist ,Glutamate receptor ,General Medicine ,Glutamic acid ,Ascorbic acid ,Dose–response relationship ,Dizocilpine Maleate ,Excitatory Amino Acid Antagonists - Abstract
The present study was designed to investigate the effects of acute and chronic administration of MK-801 (0.6 mg/kg), a noncompetitive NMDA-receptor antagonist on extracellular glutamate (Glu) and ascorbic acid (AA) release in the prefrontal cortex (PFC) of freely moving mice using in vivo microdialysis with open-field behavior. In line with earlier studies, acute administration of MK-801 induced an increase of Glu in the PFC. We also observed single MK-801 treatment increased AA release in the PFC. In addition, our results indicated that the basal AA levels in the PFC after MK-801 administration for 7 consecutive days were significantly decreased, and basal Glu levels also had a decreased tendency. After chronic administration (0.6 mg/kg, 7 days), MK-801 (0.6 mg/kg) challenge significantly decreased dialysate levels of AA and Glu. Our study also found that both acute and chronic administration of MK-801 induced hyperactivity in mice, but the intensity of acute administration was more than that of chronic administration. Furthermore, in all acute treatment mice, individual changes in Glu dialysate concentrations and the numbers of locomotion were positively correlated. In conclusion, this study may provide new evidence that a single MK-801 administration induces increases of dialysate AA and Glu concentrations in the PFC of freely moving mice, which are opposite to those induced by repeated MK-801 administration, with an unknown mechanism. Our results suggested that redox-response might play an important role in the model of schizophrenic symptoms induced by MK-801.
- Published
- 2006
10. [Primary co-culture of cortical neurons and astrocytes of new-born SD rats]
- Author
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Cheng-na, Wang, Li, Lin, Zhen-fang, Duan, Fei, Zhong, Dai-ying, Zuo, and Ying-liang, Wu
- Subjects
Cerebral Cortex ,Male ,Neurons ,Rats, Sprague-Dawley ,Animals, Newborn ,Astrocytes ,Primary Cell Culture ,Animals ,Female ,Cells, Cultured ,Coculture Techniques ,Rats - Abstract
This study is to establish a simple and practical co-culture method of cortical neurons and astrocytes of rats. The cortex of the new-born SD rats was digested by 0.125% pancreatic enzyme, and the differential adherence was applied to obtain the mixed cell suspension of neurons and astrocytes. A low concentration of cytarabine was used to inhibit the astrocytes in a moderate way to get neuronal and astrocyte co-culture. The morphological characteristics of the cells in different times were observed under the inverted microscope. The cells began to adhere the wall 2 h after the inoculation. Neurons and astrocytes grew in a good condition under the inverted microscope 9 days after the inoculation. The results of the immunofluorescence staining and Rosenfeld's staining indicated that the co-culture of neurons and astrocytes was successful and the ratio of neurons and astrocytes was close to 1:1. A new neurons and astrocytes co-culture method, which is simple and convenient, was successfully established. It will be an efficient method for the related researches about neuronal and astrocyte co-culture in vitro.
- Published
- 2014
11. Open conformation of hERG channel turrets revealed by a specific scorpion toxin BmKKx2
- Author
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Jing Jing Wei, Yi Mei Du, Tian Li, Ying Liang Wu, Wenxin Li, Jun Hu, You Tian Hu, Jing Feng, and Zhi Jian Cao
- Subjects
congenital, hereditary, and neonatal diseases and abnormalities ,Mesobuthus martensii ,Mutant ,hERG ,Pharmacology ,medicine.disease_cause ,Turret ,General Biochemistry, Genetics and Molecular Biology ,Molecular mechanism ,BmKKx2 ,medicine ,cardiovascular diseases ,Alanine ,Scorpion toxin ,biology ,Chemistry ,Toxin ,Research ,Mutagenesis ,hERG channel ,biology.organism_classification ,Potassium channel ,Biophysics ,biology.protein ,Pore region - Abstract
Background The human ether-a-go-go-related gene potassium channel (hERG) has an unusual long turret, whose role in recognizing scorpion toxins remains controversial. Here, BmKKx2, the first specific blocker of hERG channel derived from scorpion Mesobuthus martensii, was identified and the turret role of hERG channel was re-investigated using BmKKx2 as a molecular probe. Results BmKKx2 was found to block hERG channel with an IC50 of 6.7 ± 1.7 nM and share similar functional surface with the known hERG channel inhibitor BeKm-1. The alanine-scanning mutagenesis data indicate that different residue substitutions on hERG channel by alanine decreased the affinities of toxin BmKKx2 by about 10-fold compared with that of wild-type hERG channel, which reveals that channel turrets play a secondary role in toxin binding. Different from channel turret, the pore region of hERG channel was found to exert the conserved and essential function for toxin binding because the mutant hERG-S631A channel remarkably decreased toxin BmKKx2 affinity by about 104-fold. Conclusions Our results not only revealed that channel turrets of hERG channel formed an open conformation in scorpion toxin binding, but also enriched the diversity of structure-function relationships among the different potassium channel turrets.
- Published
- 2014
12. Effects of Acute and Chronic Administration of MCI-225, a New Selective Noradrenaline Reuptake Inhibitor With 5-HT3 Receptor Blocking Action, on Extracellular Noradrenaline Levels in the Hypothalamus of Stressed Rats
- Author
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Hideo Ishii, Kiminori Koga, Masatoshi Tanaka, Ying-Liang Wu, Masami Yoshida, and Hiroyuki Emoto
- Subjects
Pharmacology ,medicine.medical_specialty ,biology ,medicine.drug_class ,Chemistry ,behavioral disciplines and activities ,Anxiolytic ,5-HT3 receptor ,Basal (phylogenetics) ,Endocrinology ,Hypothalamus ,Internal medicine ,mental disorders ,medicine ,Systemic administration ,Extracellular ,biology.protein ,Antidepressant ,Reuptake inhibitor - Abstract
In the present study, we investigated the effects of acute and chronic systemic administration of MCI-225 (4-(2-fluorophenyl)-6-methyl-2-(1-piperazinyl)thieno[2,3-d]pyrimidine monohydrate hydrochloride), a newly-developed selective noradrenaline (NA) reuptake inhibitor with 5-HT3-receptor-blocking action, on extracellular NA levels in the hypothalamus of stressed and non-stressed rats by utilizing intracerebral microdialysis. Acute administration of MCI-225 (3 and 10 mg/kg, p.o.) significantly and dose-dependently increased extracellular NA levels in the hypothalamus in non-stressed rats. Footshock for 20 min also significantly increased NA levels in the hypothalamus of both groups of rats pretreated with vehicle and MCI-225. Although chronic administration of MCI-225 (3 or 10 mg/kg, p.o. for 14 days) did not alter the basal extracellular NA levels in the hypothalamus, the stress-induced increases in extracellular NA levels were significantly lower in rats chronically treated with MCI-225 (10 mg/kg) than those of rats pretreated with vehicle for the same period. The increase in extracellular NA levels induced by MCI-225 challenge (3 or 10 mg/kg, p.o.) were not different between rats chronically treated with MCI-225 or vehicle. These results suggest that MCI-225 enhances extracellular NA levels in the hypothalamus in both non-stressed and stressed rats by inhibiting NA uptake and that chronic systemic administration of MCI-225 did not alter basal extracellular NA levels, but reduced the increase in NA release caused by footshock stress. These data suggest the possibility that MCI-225 might possess anxiolytic and/or antidepressant properties.
- Published
- 2000
13. TOPSIS-based synthetic evaluation method for customer satisfaction
- Author
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Xing-Yan Zhu and Ying-Liang Wu
- Subjects
Service quality ,Voice of the customer ,Knowledge management ,Process management ,Standardization ,business.industry ,Computer science ,Information system ,Entropy (information theory) ,Service level objective ,Customer satisfaction ,TOPSIS ,business - Abstract
Quantitative evaluation of service quality is very important in modern service industry, so there has important theoretical and practical significance of studying comprehensive evaluation method of customer satisfaction. This paper discusses customer satisfaction concept and constructs evaluation index system for customer satisfaction oriented information service, then describes the theories and procedures of TOPSIS evaluation method and entropy weighted method. Finally, this paper takes university library-a typical kind of information service industry for example, using TOPSIS method to evaluate the library's reader satisfaction, discusses the evaluation results and gives suggestions for improving its information service quality and level based on the results.
- Published
- 2011
14. Research on the E-Commerce-oriented solution of reengineering and operating of business model of specialized market in China: With the case of SJQ.cn
- Author
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Ying-Liang Wu and Yuqiong Yang
- Subjects
Structure (mathematical logic) ,Distributed database ,business.industry ,Computer science ,media_common.quotation_subject ,E-commerce ,Business process reengineering ,Modular design ,Business model ,Manufacturing engineering ,The Internet ,Marketing ,business ,Function (engineering) ,media_common - Abstract
This paper systematically analyzed specialized market's demands and business models of E-Commerce, made a research on the construction of E-Commerce platform for specialized market, and presented the general system structure. On this basis, a modular and integrate function structure was proposed by structural system design. Finally we used a specific case to provide a feasible solution for the development of E-Commerce platform for specialized market.
- Published
- 2011
15. [Correlation between the refractory periods and threshold potentials and the spike programming in cortical neurons]
- Author
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Na, Chen, Ying-Liang, Wu, and Jin-Hui, Wang
- Subjects
Cerebral Cortex ,Neurons ,Rats, Sprague-Dawley ,Patch-Clamp Techniques ,Animals, Newborn ,Refractory Period, Electrophysiological ,Interneurons ,Pyramidal Cells ,Action Potentials ,Animals ,Differential Threshold ,Synaptic Transmission ,Rats - Abstract
To investigate the intrinsic mechanisms underlying spike programming at pyramidal neurons and interneurons in layer II/III of sensorimotor cortex.Electrical signals at the cortical neurons were recorded in current clamp model with multi-clamp700B Amplifiers. Signals were inputted into pClamp and Origin for data acquisition and analyses.Compared to pyramidal neurons, interneurons express the higher capacity of spikes and the more stability of spike programming, which are mechanistically caused by lower threshold potentials and shorter refractory periods.The refractory periods and threshold potentials directly influence the programming of sequential spikes.
- Published
- 2010
16. Research on the Wiki & HIS-Based Application Mode of Hospital Knowledge Management
- Author
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Ying-liang Wu and Chuan-yang Wang
- Subjects
Hospital information system ,Information management ,InformationSystems_GENERAL ,Knowledge management ,Mode (computer interface) ,business.industry ,Computer science ,Data management ,Information system ,Informatization ,Construct (philosophy) ,business ,Requirements analysis - Abstract
Through the requirement analysis of hospital management, the paper elaborates the necessity and feasibility of hospital informatization from the traditional information management to knowledge management based on the hospital information system (HIS hereafter). With the discussion of knowledge management mechanisms and characteristics of Wiki, a Wiki & HIS-based application mode of hospital knowledge management is put forward with a case of the clinician combined with his practical application. This solution can organically match the e-commerce service mode and the techniques of Web2.0 to the requirement of hospital knowledge management, and is helpful to construct the new dynamic, open, distributed and service-oriented hospital information system.
- Published
- 2010
17. The Industry Information Oriented Construction and Operating of E-Exchange
- Author
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Ying-liang Wu, Chen Han, and Cheng-zhou Wu
- Subjects
Industry classification ,Commerce ,Electronic business ,business.industry ,Software construction ,Information system ,Information revolution ,Business ,E-commerce ,Business model ,Industrial organization ,Plastics industry - Abstract
The main role of E-Business in the information revolution concentrates on reconstructing and optimizing the traditional business model and the mechanism of value-creating. With the development of the industry information, many types of e-markets have been emerging, and E-exchange is just one of them. On the background of Guangdong Plastics Exchange’s practical program construction, the article summarizes and analyses the concept and characters of E-exchange on the basic of the construction of the plastics exchange e-market, and describes all its functions, as well as opens out the business model and operation mechanism. Finally, it points out that developing and constructing staple commodity exchange e-markets that orient to different industries, would be an important prospect of the industry information in future in China.
- Published
- 2010
18. Research on the Knowledge Management Solution for Learning Organizations
- Author
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Yu-qiong Yang and Ying-liang Wu
- Subjects
Software ,Knowledge management ,business.industry ,Computer science ,Data management ,Organizational learning ,Knowledge engineering ,Personal knowledge management ,Knowledge value chain ,Domain knowledge ,Learning organization ,business - Abstract
This paper carried on an analysis to the knowledge management requirements of learning organizations. Based on the requirements and the knowledge management methods, a new knowledge management solution on the learning organizations has been proposed, and the functions of the new solution have been pointed out concretely.
- Published
- 2010
19. Research on the Evaluation Method for Enterprise Knowledge Management Performance Based on Triangular Fuzzy Number
- Author
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Ying-liang Wu and Xing-Yan Zhu
- Subjects
Index (economics) ,Empirical research ,Knowledge management ,Order (exchange) ,Computer science ,business.industry ,Capital (economics) ,Fuzzy set ,Fuzzy number ,business ,Fuzzy logic ,Intellectual capital - Abstract
To evaluate exactly the performance of knowledge management (KM) is an important part of the construction of enterprise knowledge management systems. Based on enterprise capital, a performance evaluation index system has designed by using intellectual capital, organization capital and market capital as subjects in this paper. In order to realize quantitative calculation for qualitative index, a fuzzy calculation method, that is triangular fuzzy number (TFN) evaluation method is proposed. Then the method’s theory and steps are discussed. Finally, the empirical study has been done on three IT enterprises, use TFN method to evaluate their KM performance, and some improvement suggestions are given based on evaluation results.
- Published
- 2010
20. Research on the Security Solution of the Industry Oriented E-Exchange
- Author
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Ying-Liang Wu and Xing-Yan Zhu
- Subjects
Security engineering ,ITIL security management ,Commerce ,Cloud computing security ,Security service ,Risk analysis (engineering) ,Computer science ,Software security assurance ,Security convergence ,Sherwood Applied Business Security Architecture ,Network security policy ,Information security ,Computer security model - Abstract
The development of industry informationization and electronic commerce (e-commerce) promote the emergence of electronic market (e-market). One called electronic exchange (e-exchange) is a typical business model. It requires a higher security level for the business operating system. This paper systematically studies the e-exchange security problems from the view of e-commerce security, analyzes the security requirements of e-exchange and discusses the security mechanism and service. Basing on these, the paper proposes a security solution of the e-exchange. Finally the paper elaborates the realization and application of this solution combined with the case of Guangdong Plastics Exchange (GDPE.com).
- Published
- 2009
21. A Knowledge Management Solution Based on Enterprise Information Portal
- Author
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Xue Wang and Ying-Liang Wu
- Subjects
Knowledge management ,Process management ,Enterprise architecture management ,business.industry ,Computer science ,Enterprise integration ,Enterprise architecture ,Integrated enterprise modeling ,Enterprise application integration ,Enterprise information system ,business ,Enterprise planning system ,Enterprise software - Abstract
Knowledge management (KM) is a new problem for e- commerce and enterprise application integration (EAI) , and it has become one of the research front and hotspots in management science and engineering. In this paper, the requirements and key problems of e-commerce application oriented enterprise KM are discussed, a enterprise information portal(EIP) based KM solution is presented, the key techniques for implementation are pointed. At last, a case of Midea is studied, in addition, the developing trends and foreground of KM are discussed also.
- Published
- 2009
22. Research on the Performance Measurement of Knowledge Management Based on Principal Component Analysis
- Author
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Ying-Liang Wu, Hao-Su Wu, and Xue Wang
- Subjects
Information management ,Knowledge management ,Index system ,business.industry ,Computer science ,Organizational learning ,Principal component analysis ,Performance measurement ,Learning organization ,business ,Maturity (finance) ,Case analysis - Abstract
As an important part of knowledge management (KM), the KM performance evaluation tries to find out the key factors restraining the enhancement of the enterprises' performance. In this paper, some primary factors of the performance of enterprises KM are analyzed and an index system of KM performance is established by considering some aspects, such as marketing capability, information management, maturity degree of the learning organizations, and knowledge stocks. A principal component analysis and the arithmetic steps for principal component analysis are presented to evaluate the KM performance. The case analysis shows that the principal component analysis method is efficient and practical for the KM performance evaluation.
- Published
- 2009
23. [Apoptosis induced by NNAMB, a novel polyamine conjugate, in human erythroleukemia K562 cells and its mechanism]
- Author
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Song-Qiang, Xie, Ying-Liang, Wu, Guang-Chao, Liu, Peng-Fei, Cheng, Min-Wei, Wang, Yuan-Fang, Ma, Jin, Zhao, and Chao-Jie, Wang
- Subjects
Anthracenes ,Membrane Potential, Mitochondrial ,Caspase 8 ,Caspase 3 ,Spermidine ,Cell Cycle ,Polyamines ,Cytochromes c ,Humans ,Apoptosis ,K562 Cells ,Caspase 9 ,Cell Proliferation - Abstract
To investigate the apoptosis-inducing effects of NNAMB, a novel polyamine conjugate, in erythroleukemia K562 cells and its molecular mechanism.Cell viability was assessed by MTT assay and trypan blue dye exclusion method. The cell morphology was observed by fluorescence microscopy. The cell cycle distribution, apoptosis and mitochondrial membrane potential were measured by flow cytometry. The expression of caspase-3, -8, -9, cytochrome c in the K562 cells was detected by Western blot.NNAMB inhibited the proliferation of K562 cells. The cells treated with NNAMB showed a typical apoptotic morphology, Sub-G1 peak and loss of mitochondrial membrane potential. Western blot assay showed that NNAMB increased the expression of caspase-3, -9, cytochrome c but not caspase-8 in a dose-and time-dependent manner.NNAMB induces apoptosis via mitochondrial pathway in K562 cells.
- Published
- 2008
24. Chronic organophosphate (OP)-induced neuropsychiatric disorder is a withdrawal syndrome
- Author
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Chun-Feng Lu, Shuangqing Peng, De-Hong Tan, Chang-Hui Yan, Yi-Mei Wang, and Ying-Liang Wu
- Subjects
Pediatrics ,medicine.medical_specialty ,Mental Disorders ,Organophosphate ,General Medicine ,Substance Withdrawal Syndrome ,chemistry.chemical_compound ,Neuropsychiatric disorder ,Organophosphorus Compounds ,chemistry ,Anesthesia ,medicine ,Cholinergic ,Humans ,Withdrawal syndrome ,Psychology - Abstract
Chronic organophosphate-induced neuropsychiatric disorder is a less well-characterized syndrome, which is usually delay-occurred, persists long and is similar to the symptom of cholinergic deficit, its mechanism is unclear. The characteristics of chronic organophosphate-induced neuropsychiatric disorder are somewhat opposite to the direct action of OP pesticide, since withdrawal effect is usually opposite to the original effect of a drug, hypothesis that chronic organophosphate-induced neuropsychiatric disorder is a kind of withdrawal syndrome is suggested.
- Published
- 2008
25. Research on the Overall Framework of Knowledge Management
- Author
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Jing-Jing Pang and Ying-Liang Wu
- Subjects
Information management ,Process management ,Knowledge management ,business.industry ,Computer science ,Program management ,Data management ,Knowledge engineering ,Knowledge value chain ,Mathematical knowledge management ,computer.software_genre ,Technology management ,Systems management ,Organizational learning ,Personal knowledge management ,Enterprise relationship management ,Domain knowledge ,business ,Digital firm ,Management process ,computer - Abstract
Dispute about conception and research area of knowledge management exists always. In order to distinguish and evaluate about the influence factor of the success or failure of knowledge management project, it is necessary to understand it in the point of system thought and to design an integrated entirely knowledge management framework model that is accepted at large. Firstly, this article starts with the research on the present knowledge management and the analysis of different views, discussing the system framework, connotation and extension of knowledge management with systemic viewpoint. Then the paper will develop a knowledge management framework model and propose a system framework of knowledge management system and its practical application.
- Published
- 2008
26. Study on Knowledge Acquisition of the Telecom Customers' Consuming Behaviour Based on Data Mining
- Author
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Chunfang Zhao, Haijun Gao, and Ying-Liang Wu
- Subjects
Customer knowledge ,Voice of the customer ,Customer retention ,business.industry ,computer.software_genre ,Customer advocacy ,Customer Service Assurance ,Customer reference program ,Data mining ,Customer intelligence ,Telecommunications ,business ,Customer to customer ,computer - Abstract
As the reform development of telecom industry and the entrance of WTO, the competition among the telecom enterprises is becoming tougher. Nowadays, "customer-oriented" is the new principle of telecom market competition. As the enterprises in telecom industry have much more customers and customer data than those in other industries, the application of customer relationship management (CRM) in telecom industry becomes one of the hottest topics on enterprise informationlization. The thesis discusses the discovery of telecom customer knowledge based on data-mining. In this paper, a customer analysis model is founded by the method of data mining, including customer segmentation analysis, customer churn analysis, customer owing and fraud analysis. In the end, the thesis introduces a real case of a customer segmentation project in a mobile communication company and illustrates the application detail of customer intelligence in this company. In this case, the author uses SPSS Clementine to conduct data-mining. Meanwhile, diverse marketing strategy is also proposed based on the customer segmentation knowledge.
- Published
- 2008
27. Research on the Model of Knowledge Audit
- Author
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Ying-Liang Wu and Yi-Hua Li
- Subjects
Strategic planning ,Knowledge management ,business.industry ,Computer science ,Knowledge value chain ,Audit ,Intellectual capital ,Knowledge-based systems ,Workflow ,Internal audit ,Organizational learning ,Personal knowledge management ,Information technology audit ,business - Abstract
Knowledge management (KM) system includes KM strategic planning, technique, culture foundation, knowledge resource, process of knowledge transformation and exterior circumstance. Whether the definitude of KM stratagem or the early requirement design of KM implement, it must to evaluate the KM performance, to audit the KM requirement and program and to fulfill the KM process positive and feedback closed loop system. Organizations can set down KM strategy and programming and implement effectively no other than understanding its own knowledge stock, processes and requirement; can optimize KM no other than timely evaluating and auditing KM. This article introduce the concept of knowledge capital which root in intellectual capital as the object of the knowledge audit, thus the research fruit of intellectual capital could be used to study knowledge audit. Based on that, this article put forwards the integrity conception of KM audit, constitutes a conception model of knowledge audit and presents the workflow and currently methods of implementing knowledge audit.
- Published
- 2008
28. A Management Object Oriented Solution of Knowledge Management System
- Author
-
Bo Zhou and Ying-Liang Wu
- Subjects
Information management ,Structure of Management Information ,Knowledge management ,Computer science ,business.industry ,Data management ,Knowledge engineering ,Knowledge value chain ,Risk management information systems ,Document management system ,Mathematical knowledge management ,computer.software_genre ,Knowledge-based systems ,Knowledge extraction ,Knowledge base ,Organizational learning ,Personal knowledge management ,Information system ,Domain knowledge ,business ,Management process ,computer ,Digital firm - Abstract
With the development of information system, there is an urgent need for enterprises to change from information management to knowledge management. In the network-computing environment, enterprises need to apply the complex, dynamic and integrated, object-oriented knowledge management system. First, this paper analyzed the essence of knowledge and knowledge management, discussed the concept and characteristics of enterprise knowledge portal. On this basis, the article proposed a management object oriented solution of knowledge management system, focusing on the framework of the system, mode of operation and the value of application with a case study. Such a solution can help enterprises to establish open, dynamic and integrated information and knowledge management systems.
- Published
- 2008
29. A Fuzzy Information Retrieval Method Based on the Vector-Correlative Model
- Author
-
Ying-liang Wu and Bo Zhou
- Subjects
Structure (mathematical logic) ,Computer science ,business.industry ,Fuzzy set ,Knowledge engineering ,Information processing ,Construct (python library) ,computer.software_genre ,Machine learning ,Fuzzy logic ,Algorithm design ,Data mining ,Artificial intelligence ,Precision and recall ,business ,computer - Abstract
The VCM (Vector-Correlative Model) is one of the currently popular models for information searching. In this paper, author inducted Fuzzy Sets theory and approach for to construct information searching models, and presented a new VCM, which is called Fuzzy Vector-correlative Model (FVCM). So, its theory structure and user's searching quizzing mode has been dimming improved. We have show with some fringe experimentation that the new model has overcome some intrinsic defects of the exciting ones, and has raised the precision and recall of information search system.
- Published
- 2008
30. [Process of HIV-1 reverse transcription and its detection by using PCR]
- Author
-
Wen-Xue, Yao, Ying-Liang, Wu, and Ying, Guo
- Subjects
DNA Replication ,DNA, Viral ,HIV-1 ,RNA, Viral ,Reverse Transcription ,Polymerase Chain Reaction ,HIV Reverse Transcriptase - Abstract
Human immunodeficiency virus (HIV) is a retrovirus, belongs to Lentiviridae family. As long as viral genetic material entering into host cytoplasm, double-strand DNAs synthesis occurs which is catalyzed by reverse transcriptase (RT) with viral plus-strand RNA as template. This reverse transcription is a key link of HIV-1 life cycle and an important target for anti-HIV drug development. The process of reverse transcription can be divided into several steps: formation of minus-strand strong-stop DNA; the first translocation; initiation of plus-strand DNA synthesis; and, the second translocation and the completion of both strands. These steps can be detected individually by using polymerase chain reaction (PCR) according to the amplified products on the region of R/U5, U3, U5/PBS and the sequence between LTR and Gag. In this review, we summarize the principle for detecting stages of HIV-1 reverse transcription by using PCR.
- Published
- 2008
31. A Research of Value-Net Based Business Model and Operating of M-Commerce
- Author
-
Haosu Wu, Chin E. Lin, and Ying-Liang Wu
- Subjects
Engineering management ,Process modeling ,Process management ,Electronic business ,New business development ,Artifact-centric business process model ,Mobile business development ,Consumer-to-business ,Business ,Business process modeling ,Business model - Abstract
Recent advances in Internet and e-commerce have led industry to reengineer their organizational structures and value chains. One of the most prominent trends in this change is to conduct work and operation in the distributed or virtual environments. A new kind of business model, termed as value-net, is emerging. In this paper, the business and system mode from the value-net system is studied and proposed. The feature of this business model suitable for Mobile Commerce (M-Commerce) is analyzed on the basis of value-net. The ecosystems (ecology system) model based on value-net is presented for the M-Commerce with systematic structure, collaborate mode and working mechanism. A modified value-net based ecosystem for M-Commerce operators is proposed in this paper with practical case analysis.
- Published
- 2007
32. Molecular cloning and electrophysiological studies on the first K(+) channel toxin (LmKTx8) derived from scorpion Lychas mucronatus
- Author
-
Geliang Gan, Ying Liang Wu, Zhijian Cao, Yibao Ma, Shijin Yin, Wenxin Li, Ruiming Zhao, Wenlan Wu, and Jiuping Ding
- Subjects
Models, Molecular ,Subfamily ,DNA, Complementary ,Patch-Clamp Techniques ,Physiology ,Recombinant Fusion Proteins ,Molecular Sequence Data ,Scorpion Venoms ,Peptide ,Venom ,Biology ,Molecular cloning ,medicine.disease_cause ,Biochemistry ,law.invention ,Cell Line ,Scorpions ,Cellular and Molecular Neuroscience ,Endocrinology ,law ,medicine ,Potassium Channel Blockers ,Animals ,Humans ,Amino Acid Sequence ,Cloning, Molecular ,DNA Primers ,chemistry.chemical_classification ,Kv1.3 Potassium Channel ,Base Sequence ,Sequence Homology, Amino Acid ,Toxin ,cDNA library ,HEK 293 cells ,Molecular biology ,Electrophysiology ,Molecular Weight ,chemistry ,Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ,Recombinant DNA - Abstract
LmKTx8, the first toxic gene isolated from the venom of scorpion Lychas mucronatus by constructing cDNA library method, was expressed and characterized physiologically. The mature peptide has 40 residues including six conserved cysteines, and is classified as one of α-KTx11 subfamily. Using patch-clamp recording, the recombinant LmKTx8 (rLmKTx8) was used to test the effect on voltage-gated K+ channels (Kv1.3) stably expressed in COS7 cells and large conductance-Ca2+-activated K+ (BK) channels expressed in HEK293. The results of electrophysiological experiments showed that the rLmKTx8 was a potent inhibitor of Kv1.3 channels with an IC50 = 26.40 ± 1.62 nM, but 100 nM rLmKTx8 did not block the BK currents. LmKTx8 or its analogs might serve as a potential candidate for the development of new drugs for autoimmune diseases.
- Published
- 2007
33. Synergistic antitumor effects of anthracenylmethyl homospermidine and alpha-difluoromethylornithine on promyelocytic leukemia HL60 cells
- Author
-
Songqiang Xie, Chaojie Wang, Min-wei Wang, Jin Zhao, Ying-liang Wu, Yuanfang Ma, Bian-sheng Ji, Guangchao Liu, and Peng-fei Cheng
- Subjects
Eflornithine ,Spermidine ,Blotting, Western ,Antineoplastic Agents ,Apoptosis ,HL-60 Cells ,Toxicology ,Flow cytometry ,Membrane Potentials ,medicine ,Humans ,MTT assay ,Enzyme Inhibitors ,Caspase ,Cell Proliferation ,Fluorescent Dyes ,Anthracenes ,medicine.diagnostic_test ,biology ,Cell growth ,Cytochrome c ,Cell Cycle ,Cytochromes c ,Drug Synergism ,General Medicine ,Cell cycle ,medicine.disease ,Flow Cytometry ,Molecular biology ,Caspase Inhibitors ,Leukemia ,Caspases ,Mitochondrial Membranes ,biology.protein ,Apoptosis Regulatory Proteins ,Fluorescein-5-isothiocyanate - Abstract
The present study was designed to assess the synergistic antitumor effects of anthracenylmethyl homospermidine (ANTMHspd), a novel polyamine conjugate, with alpha-difluoromethylornithine (DFMO) and to elucidate the mechanism of these effects on human leukemia HL60 cells. Cell proliferation was assessed by the MTT assay. Cell cycle, apoptosis and mitochondria membrane potential (MMP) were evaluated by flow cytometry. Caspases and cytochrome c were detected by Western Blot analysis. The combination treatment strongly inhibited cell proliferation, induced cell apoptosis and caused an accumulation in the G1 phase with an accompaniment decrease in S phase. Moreover, reduction of MMP, release of cytochrome c and activation of caspase-3 and caspase-9 but not caspase-8 were observed during the combination-mediated apoptosis. All these findings demonstrated that the combination treatment with DFMO and ANTMHspd resulted in synergistic antitumor effects on HL60 cells.
- Published
- 2007
34. Effect of MK-801 and ketamine on hydroxyl radical generation in the posterior cingulate and retrosplenial cortex of free-moving mice, as determined by in vivo microdialysis
- Author
-
Dai-Ying Zuo, Masatoshi Tanaka, Wen-Xue Yao, Ying-Liang Wu, Yue Cao, and Chunfu Wu
- Subjects
Cingulate cortex ,Male ,medicine.medical_specialty ,Microdialysis ,Psychosis ,Clinical Biochemistry ,Catechols ,Toxicology ,Biochemistry ,Gyrus Cinguli ,Behavioral Neuroscience ,Mice ,Internal medicine ,medicine ,Hydroxybenzoates ,Animals ,Ketamine ,Biological Psychiatry ,Pharmacology ,Cerebral Cortex ,Behavior, Animal ,Chemistry ,Hydroxyl Radical ,Neurotoxicity ,medicine.disease ,Dizocilpine ,Endocrinology ,Posterior cingulate ,Anesthesia ,NMDA receptor ,Dizocilpine Maleate ,Stereotyped Behavior ,Extracellular Space ,Excitatory Amino Acid Antagonists ,medicine.drug - Abstract
This study investigated the effect of MK-801 and ketamine, N-methyl-D-aspartate (NMDA) receptor antagonists which can induce schizophrenic symptoms and have neurotoxicity in human and animals, on hydroxyl radical (*OH) generation in the posterior cingulate and retrosplenial (PC/RS) cortex of free-moving mice using the salicylic acid trapping technique. MK-801 (0.6 mg/kg) or ketamine (50 mg/kg) acute administration significantly increased *OH levels in mouse PC/RS cortex. The basal *OH levels after MK-801 and ketamine administrations for 7 consecutive days were significantly increased compared with the naive basal levels. MK-801 (0.6 mg/kg) or ketamine (50 mg/kg) challenge after chronic administration further significantly increased dialysate levels of *OH. Our study also found that the release of *OH was secondary to stereotyped behavior, and the intensity of stereotyped behavior induced by MK-801 was more than that induced by ketamine. The results suggested that NMDA receptor antagonists participate in the generation of *OH in the PC/RS cortex of mouse, and oxidative stress, derived from the formation of free radicals, might play an important role in the pathophysiology of these two models of schizophrenia.
- Published
- 2005
35. Neuroprotective effects of Polygonum multiflorum on nigrostriatal dopaminergic degeneration induced by paraquat and maneb in mice
- Author
-
Ying-Liang Wu, Yukihisa Murakami, Kinzo Matsumoto, Xia Li, Yasuhiro Tezuka, and Shigetoshi Kadota
- Subjects
Male ,Paraquat ,medicine.medical_specialty ,Tyrosine 3-Monooxygenase ,Dopamine ,Clinical Biochemistry ,Maneb ,Nigrostriatal pathway ,Substantia nigra ,Striatum ,Biology ,Motor Activity ,Toxicology ,Biochemistry ,Plant Roots ,Antiparkinson Agents ,Levodopa ,Behavioral Neuroscience ,chemistry.chemical_compound ,Mice ,Neurochemical ,Internal medicine ,medicine ,Animals ,Parkinson Disease, Secondary ,Biological Psychiatry ,Chromatography, High Pressure Liquid ,Pharmacology ,Tyrosine hydroxylase ,Herbicides ,Dopaminergic ,Immunohistochemistry ,Fungicides, Industrial ,Mice, Inbred C57BL ,Neostriatum ,Substantia Nigra ,medicine.anatomical_structure ,Endocrinology ,Neuroprotective Agents ,nervous system ,chemistry ,Nerve Degeneration ,3,4-Dihydroxyphenylacetic Acid ,Polygonum ,medicine.drug ,Phytotherapy - Abstract
The neuroprotective effects of Polygonum multiflorum extract (PME) and its two fractions, ethanol-soluble PME (PME-I) and -insoluble PME (PME-II), on the degeneration of nigrostriatal dopaminergic neurons induced by a combination of paraquat and maneb (PQMB) were investigated in male C57BL/6 mice. The mice were treated twice a week for 6 weeks with intraperitoneal injections of PQMB. This combination caused a reduction of spontaneous locomotor activity, motor incoordination, and declines of dopamine level in the striatum and tyrosine hydroxylase-positive neurons in the substantia nigra. Administration of PME and PME-I once daily for 47 days during 6 weeks of PQMB treatment and last 8 days after PQMB significantly attenuated the impairment of behavioral performance and the decrease in striatal dopamine level and substantia nigral tyrosine hydroxylase-positive neurons in the PQMB-treated animals, whereas the administration of PME-II had no effect on these behavioral, neurochemical and histological indices. The present findings suggest that PME has a beneficial influence on parkinsonism induced by PQMB and that the effects of PME are attributable to some substance(s) included in the ethanol-soluble fraction of PME (PME-I).
- Published
- 2005
36. Psychological stress selectively increases extracellular dopamine in the 'shell', but not in the 'core' of the rat nucleus accumbens: a novel dual-needle probe simultaneous microdialysis study
- Author
-
Masami Yoshida, Ying-Liang Wu, Hiroyuki Emoto, and Masatoshi Tanaka
- Subjects
Male ,Microdialysis ,General Neuroscience ,Dopamine ,Nucleus accumbens ,Nucleus Accumbens ,Rats ,chemistry.chemical_compound ,Neurochemical ,chemistry ,Basal ganglia ,medicine ,Catecholamine ,Extracellular ,Biophysics ,Animals ,Rats, Wistar ,Neurotransmitter ,Extracellular Space ,Neuroscience ,Stress, Psychological ,medicine.drug - Abstract
In order to compare psychological stress-induced dopamine (DA) release in two subterritories (e.g. shell and core) of the nucleus accumbens of the same animal, a novel dual-needle microdialysis probe has been developed. The two needles were placed in the ipsilateral shell and core subterritories of the nucleus accumbens under pentobarbital anesthesia and 24 h later the microdialysis was started. Basal DA output was not significantly different between the shell and the core. Psychological stress for 20 min significantly increased extracellular DA levels in the shell of the nucleus accumbens, however, the levels of dopamine remained almost unaltered in the core. This finding suggests that DA transmission in the shell of the nucleus accumbens was selectively activated during psychological stress, and that the shell plays an important role in emotional responses. The results further show that microdialysis using the novel dual-needle probe could be very useful to differentiate neurochemical changes occurring in neighboring areas in the brain.
- Published
- 1999
37. Psychological stress selectively increases extracellular dopamine in the 'shell' as compared with the 'core of the rat nucleus accumbens
- Author
-
Hiroyuki Emoto, Ying-Liang Wu, Masatoshi Tanaka, and Masami Yoshida
- Subjects
Pharmacology ,Core (optical fiber) ,Chemistry ,medicine ,Biophysics ,Shell (structure) ,Psychological stress ,Nucleus accumbens ,medicine.disease_cause ,Extracellular dopamine - Published
- 1999
38. The effect of maternal deprivation to GABA A receptors in the prefrontal cortex of adult rats
- Author
-
Masami Yoshida, Masatoshi Tanaka, Miho Matsui, Ying-Liang Wu, and Hiroyuki Emoto
- Subjects
Pharmacology ,medicine.medical_specialty ,Maternal deprivation ,Endocrinology ,GABAA receptor ,Internal medicine ,medicine ,Biology ,Prefrontal cortex ,Receptor - Published
- 1999
39. NMDA- and MK801-induced changes in dopamine release are attenuated in kainic acid-lesioned nucleus accumbens of conscious rat
- Author
-
Kiminori Koga, Miho Matsui, Masatoshi Tanaka, Hiroyuki Emoto, Masami Yoshida, and Ying-Liang Wu
- Subjects
Pharmacology ,medicine.medical_specialty ,Kainic acid ,chemistry.chemical_compound ,Endocrinology ,Chemistry ,Dopamine ,Internal medicine ,medicine ,NMDA receptor ,Nucleus accumbens ,medicine.drug - Published
- 1999
40. Studies on potentiometric stripping analysis
- Author
-
Ying Liang Wu, De Yu Li, and Tuen Chi Chau
- Subjects
Detection limit ,Metal ,Chemistry ,visual_art ,Potentiometric titration ,Complex formation ,visual_art.visual_art_medium ,Analytical chemistry ,chemistry.chemical_element ,Analytical Chemistry ,Ion ,Mercury (element) - Abstract
Theoretical and experimental investigations have been made on the method of potentiometric stripping analysis. By solving Fick's second law of diffusion for the metal in the amalgam, it was found that tau = C(0)(R)l/k[Ox], where tau is the elapsed time, l is the thickness of the mercury film, C(0)(R) is the concentration of the metal in the amalgam, [Ox] is the concentration of the oxidant in the solution and k is a constant. Since C(0)(R) is proportional to the concentration of that particular ion in the solution under given pre-electrolysis conditions, the relations given by the equation above can all be verified experimentally. The equation of the potential-time curve and the effect of complex formation on the elapsed time were also investigated and discussed. In the absence of complexation reactions in the solution and with proper control of the concentration of the oxidant, the lowest limit of detection for Pb was found to be 10(-12)M for a 4-min pre-electrolysis, with dissolved oxygen as oxidant.
- Published
- 1982
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