Evidence for Adenosine Triphosphate (ATP) as an Excitatory Neurotransmitter in Guinea-Pig Gastric Antrum

Tong Mook Kang,Wenxie Xu,Sung Joon Kim,Seung Cheol Ahn,Young Chul Kim,Insuk So,Myoung Kyu Park,Dae-Yong Uhm,Ki Whan Kim 대한생리학회-대한약리학회 1999 The Korean Journal of Physiology & Pharmacology Vol.3 No.2

<P> We explore the question of whether adenosine 5 -triphosphate (ATP) acts as an excitatory neurotransmitter in guinea-pig gastric smooth muscle. In an organ bath system, isometric force of the circular smooth muscle of guinea-pig gastric antrum was measured in the presence of atropine and guanethidine. Under electrical field stimulation (EFS) at high frequencies (>20 Hz), NO-mediated relaxation during EFS was followed by a strong contraction after the cessation of EFS (a "rebound-contraction"). Exogenous ATP mimicked the rebound-contraction. A known P<SUB>2Y</SUB>-purinoceptor antagonist, reactive blue 2 (RB-2), blocked the rebound-contraction while selective desensitization of P<SUB>2X</SUB>-purinoceptor with α,β-MeATP did not affect it. ATP and 2-MeSATP induced smooth muscle contraction, which was effectively blocked by RB-2 and suramin, a nonselective P<SUB>2</SUB>-purinoceptor antagonist. Particularly, in the presence of RB-2, exogenous ATP and 2-MeSATP inhibited spontaneous phasic contractions, suggesting the existence of different populations of purinoceptors. Both the rebound-contraction and the agonist-induced contraction were not inhibited by indomethacin. The rank orders of agonists potency were 2-MeSATP > ATP ≥ UTP for contraction and α,β-MeATP ≥ β,γ-MeATP for inhibition of the phasic contraction, that accord with the commonly accepted rank order of the classical P<SUB>2Y</SUB>-purinoceptor subtypes. Electrical activities of smooth muscles were only slightly influenced by ATP and 2-MeSATP, whereas α,β-MeATP attenuated slow waves with membrane hyperpolarization. From the above results, it is suggested that ATP acts as an excitatory neurotransmitter, which mediates the rebound-contraction via P<SUB>2Y</SUB>-purinoceptor in guinea-pig gastric antrum.

Colonic Dysmotility in Murine Partial Colonic Obstruction Due to Functional Changes in Interstitial Cells

Qianqian Wang,Jingyu Zang,Xu Huang,Hongli Lu,Wenxie Xu,Jie Chen 대한소화기 기능성질환∙운동학회 2019 Journal of Neurogastroenterology and Motility (JNM Vol.25 No.4

Background/Aims Interstitial cells play important roles in gastrointestinal (GI) neuro-smooth muscle transmission. The underlying mechanisms of colonic dysmotility have not been well illustrated. We established a partial colon obstruction (PCO) mouse model to investigate the changes of interstitial cells and the correlation with colonic motility. Methods Western blot technique was employed to observe the protein expressions of Kit, platelet-derived growth factor receptor-α (Pdgfra), Ca2+-activated Cl− (Ano1) channels, and small conductance Ca2+- activated K+ (SK) channels. Colonic migrating motor complexes (CMMCs) and isometric force measurements were employed in control mice and PCO mice. Results PCO mice showed distended abdomen and feces excretion was significantly reduced. Anatomically, the colon above the obstructive silicone ring was obviously dilated. Kit and Ano1 proteins in the colonic smooth muscle layer of the PCO colons were significantly decreased, while the expression of Pdgfra and SK3 proteins were significantly increased. The effects of a nitric oxide synthase inhibitor (L-NAME) and an Ano1 channel inhibitor (NPPB) on CMMC and colonic spontaneous contractions were decreased in the proximal and distal colons of PCO mice. The SK agonist, CyPPA and antagonist, apamin in PCO mice showed more effect to the CMMCs and colonic smooth muscle contractions. Conclusions Colonic transit disorder may be due to the downregulation of the Kit and Ano1 channels and the upregulation of SK3 channels in platelet-derived growth factor receptor-α positive (PDGFRα+) cells. The imbalance between interstitial cells of Cajal-Ano1 and PDGFRα-SK3 distribution might be a potential reason for the colonic dysmotility. Background/Aims Interstitial cells play important roles in gastrointestinal (GI) neuro-smooth muscle transmission. The underlying mechanisms of colonic dysmotility have not been well illustrated. We established a partial colon obstruction (PCO) mouse model to investigate the changes of interstitial cells and the correlation with colonic motility. Methods Western blot technique was employed to observe the protein expressions of Kit, platelet-derived growth factor receptor-α (Pdgfra), Ca2+-activated Cl− (Ano1) channels, and small conductance Ca2+- activated K+ (SK) channels. Colonic migrating motor complexes (CMMCs) and isometric force measurements were employed in control mice and PCO mice. Results PCO mice showed distended abdomen and feces excretion was significantly reduced. Anatomically, the colon above the obstructive silicone ring was obviously dilated. Kit and Ano1 proteins in the colonic smooth muscle layer of the PCO colons were significantly decreased, while the expression of Pdgfra and SK3 proteins were significantly increased. The effects of a nitric oxide synthase inhibitor (L-NAME) and an Ano1 channel inhibitor (NPPB) on CMMC and colonic spontaneous contractions were decreased in the proximal and distal colons of PCO mice. The SK agonist, CyPPA and antagonist, apamin in PCO mice showed more effect to the CMMCs and colonic smooth muscle contractions. Conclusions Colonic transit disorder may be due to the downregulation of the Kit and Ano1 channels and the upregulation of SK3 channels in platelet-derived growth factor receptor-α positive (PDGFRα+) cells. The imbalance between interstitial cells of Cajal-Ano1 and PDGFRα-SK3 distribution might be a potential reason for the colonic dysmotility.

Colonic Transit Disorder Mediated by Downregulation of Interstitial Cells of Cajal/Anoctamin-1 in Dextran Sodium Sulfate-induced Colitis Mice

Chen Lu,Hongli Lu,Xu Huang,Shaohua Liu,Jingyu Zang,Yujia Li,Jie Chen,Wenxie Xu 대한소화기 기능성질환∙운동학회 2019 Journal of Neurogastroenterology and Motility (JNM Vol.25 No.2

Background/Aims Interstitial cells of Cajal (ICC) and their special calcium-activated chloride channel, anoctamin-1 (ANO1) play pivotal roles in regulating colonic transit. This study is designed to investigate the role of ICC and the ANO1 channel in colonic transit disorder in dextran sodium sulfate (DSS)-treated colitis mice. Methods Colonic transit experiment, colonic migrating motor complexes (CMMCs), smooth muscle spontaneous contractile experiments, intracellular electrical recordings, western blotting analysis, and quantitative polymerase chain reaction were applied in this study. Results The mRNA and protein expressions of c-KIT and ANO1 channels were significantly decreased in the colons of DSS-colitis mice. The colonic artificial fecal-pellet transit experiment in vitro was significantly delayed in DSS-colitis mice. The CMMCs and smooth muscle spontaneous contractions were significantly decreased by 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB), an ANO1 channel blocker, and NG-Nitro-L-arginine methyl ester hydrochloride (L-NAME), an inhibitor of nitric oxide synthase activity, in DSS-colitis mice compared with that of control mice. Intracellular electrical recordings showed that the amplitude of NPPB-induced hyperpolarization was more positive in DSS-colitis mice. The electric field stimulation-elicited nitric-dependent slow inhibitory junctional potentials were also more positive in DSS-colitis mice than those of control mice. Conclusion The results suggest that colonic transit disorder is mediated via downregulation of the nitric oxide/ICC/ANO1 signalling pathway in DSS-colitis mice.

China-ASEAN Police Cooperation on Combating Transnational Crime

Wenxi Bian 아시아사회과학학회 2023 Jornal of Asia Social Science Vol.11 No.1

The long-term police cooperation practices between China and ASEAN have accumulated a deep foundation of win-win resources to combat the transnational crime. Many efforts has directed by China and ASEAN member countries to combat the transnational crime. Even though there is a a great achievement in combating telecommunication and online fraud, the police cooperation have not reached up to expectations because of different laws, deceitfulness and concealment of transnational criminal groups, transferring of criminal hidden place and the new change of the criminal organization. Determined to protect the regional peace and tranquility, China and ASEAN would strengthen police cooperation in following aspects: making a comprehensive strategic road-map, promoting the integration of multi-layer cooperation mechanisms, giving full play of governmental and non-governmental organizations, and to established a China-ASEAN Information Fusion Center Against Transnational Crime.

The Effects of Government Environmental Subsidies and Corporate Environmental Investments on ESG Scores and Values of Chinese Firms

Wenxi Li(리원시),Sunghwan(김성환) 한국환경정책학회 2022 한국환경정책학회 학술대회논문집 Vol.2022 No.2

Global problems such as environmental pollution are becoming more and more serious, and countries around the world pay more attention to sustainable development. Together with the development of the economy and the improvement of the requirements for development quality, ESG factors have become an important basis for market participants such as investors, corporate managers and financial institutions to consider the sustainable development ability of enterprises. Environmental, social, and governance (ESG) scores have emerged as an important element of corporate social responsibility for the development of sustainable strategies that will impact the financial performance of multinational firms with the rapid development of Chinese economy and the improvement of its people"s income level, more and more ordinary people have entered the financial market to participate in investment and transactions. In 2019, the sudden outbreak of COVID-19 and the delisting and trading suspensions of companies in China"s capital market in recent years have caused volatility in the capital market and brought heavy losses to investors. Therefore, more investors have begun to pay attention to companies governance, accountability and the sustainability of investments in addition to their return on investment. As the traditional high input, low efficiency, and environmental polluting production method are promoted, their limitations of such policies have been pointed out for a long time. The level of personal income increased due to economic growth, Chinese people have became more aware of the seriousness of environmental problems than before. Nowadays, environmental issues are facing severe challenges and have been incorporated into the national macro-development strategy and have been highly valued by the government. The government continues to increase investment in environmental protection. Firms receive financial support from the government, which will also prompt them to pay more attention to environmental protection and pollution control, take the initiative to solve environmental problems, and use government environmental subsidies to improve their environmental performance. This study investigates the short-term and long-term effects of environmental investments and environmental subsidies on ESG scores and firm values by Chinese firms. with firm-level data of 17,042 observations (year-firms), listed on Shanghai Stock and Shenzhen Stock Exchanges for 10 years from 2010 to 2019 and report following regression results. First, environmental subsidies have a significant positive short-term effect on ESG scores. Second, environmental investments have a significant positive effect on ESG scores during the year, whose effects last for about 4 years. Third, environmental investments show a significant negative effect on all firms, and global firms on firm values for 3 years from the year. We have used to firm-level data to study the persistence of such effects. Without any prior studies in this topic, our findings are unique and intriguing and provide insights to firms, the governments, local and central, and the public in the sense of ESG, especially regarding the environment management of firms and the society, as a whole.

The Role of Short Chain Fatty Acids in Irritable Bowel Syndrome

Wenxi Jian,Jiali Wu,Shefeng Zhu,Linying Xin,Chaohui Yu,Zhe Shen 대한소화기 기능성질환∙운동학회 2022 Journal of Neurogastroenterology and Motility (JNM Vol.28 No.4

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder that is characterized by abdominal pain and disordered bowel habits. The etiology of IBS is multifactorial, including abnormal gut-brain interactions, visceral hypersensitivity, altered colon motility, and psychological factors. Recent studies have shown that the intestinal microbiota and its metabolites short chain fatty acids (SCFAs) may be involved in the pathogenesis of IBS. SCFAs play an important role in the pathophysiology of IBS. We discuss the underlying mechanisms of action of SCFAs in intestinal inflammation and immunity, intestinal barrier integrity, motility, and the microbiota-gut-brain axis. Limited to previous studies, further studies are required to investigate the mechanisms of action of SCFAs in IBS and provide more precise therapeutic strategies for IBS.

Thermometry and interpretation of body temperature

Wenxi Chen 대한의용생체공학회 2019 Biomedical Engineering Letters (BMEL) Vol.9 No.1

This article reviews the historical development and up-to-date state of thermometric technologies for measuring human bodytemperature (BT) from two aspects: measurement methodology and signifi cance interpretation. Since the fi rst systematic andcomprehensive study on BT and its relation to human diseases was conducted by Wunderlich in the late 19th century, BThas served as one of the most fundamental vital signs for clinical diagnosis and daily healthcare. The physiological implicationof BT set point and thermoregulatory mechanisms are briefl y outlined. Infl uential determinants of BT measurement areinvestigated thoroughly. Three types of BT measurement, i.e., core body temperature, surface body temperature and basalbody temperature, are categorized according to its measurement position and activity level. With the comparison of temperaturemeasurement in industrial fi elds, specialties in technological and biological aspects in BT measurement are mentioned. Methodologies used in BT measurement are grouped into instrumental methods and mathematical methods. Instrumentalmethods utilize results of BT measurements directly from temperature-sensitive transducers and electronic instrumentationsby the combination of actual and predictive measurement, invasive and noninvasive measurement. Mathematical methodsuse several numerical models, such as multiple regression model, autoregressive model, thermoregulatory mechanism-basedmodel and the Kalman fi lter-based method to estimate BT indirectly from some relevant vital signs and environmental factors. Thermometry modalities are summarized on the dichotomies into invasive and noninvasive, contact and noncontact,direct and indirect, free and restrained, 1-D and n-D. Comprehensive interpretation of BT has an equal importance as themeasurement of BT. Two modes to apply BT are classifi ed into real-time applications and long-term applications. With rapidadvancement in IoT infrastructure, big data analytics and AI platforms, prospects for future development in thermometryand interpretation of BT are discussed.

Novel Five-Level Three-Phase Hybrid-Clamped Converter with Reduced Components

Bin Chen,Wenxi Yao,Zhengyu Lu 전력전자학회 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.6

This study proposes a novel five-level three-phase hybrid-clamped converter composed of only six switches and one flying capacitor (FC) per phase. The capacitor-voltage-drift phenomenon of the converter under the classical sinusoidal pulse width modulation (SPWM) strategy is comprehensively analyzed. The average current, which flows into the FC, is a function of power factor and modulation index and does not remain at zero. Thus, a specific modulation strategy based on space vector modulation (SVM) is developed to balance the voltage of DC-link and FCs by injecting a common-mode voltage. This strategy applies the five-segment method to synthesize the voltage vector, such that switching losses are reduced while optional vector sequences are increased. The best vector sequence is then selected on the basis of the minimized cost function to suppress the divergence of the capacitor voltage. This study further proposes a startup method that charges the DC-link and FCs without any additional circuits. Simulation and experimental results verify the validity of the proposed converter, modulation strategy, and precharge method.

Parallelization and application of SACOS for whole core thermal-hydraulic analysis

Minyang Gui,Wenxi Tian,Di Wu,Ronghua Chen,Mingjun Wang,G.H. Su 한국원자력학회 2021 Nuclear Engineering and Technology Vol.53 No.12

SACOS series of subchannel analysis codes have been developed by XJTU-NuTheL for many years and arebeing used for the thermal-hydraulic safety analysis of various reactor cores. To achieve fine whole corepin-level analysis, the input preprocessing and parallel capabilities of the code have been developed inthis study. Preprocessing is suitable for modeling rectangular and hexagonal assemblies with less errorprone input; parallelization is established based on the domain decomposition method with the hybridof MPI and OpenMP. For domain decomposition, a more flexible method has been proposed which candetermine the appropriate task division of the core domain according to the number of processors of theserver. By performing the calculation time evaluation for the several PWR assembly problems, the codeparallelization has been successfully verified with different number of processors. Subsequent analysisresults for rectangular- and hexagonal-assembly core imply that the code can be used to model andperform pin-level core safety analysis with acceptable computational efficiency

The Effects of Government Environmental Subsidies and Corporate Environmental Investments on Carbon Emissions of Chinese Firms

Sunghwan Kim,Wenxi Li,Yongshang Liu 한국환경정책학회 2021 環境政策 Vol.29 No.특별호