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Geometrical transition properties of vortex cavitation and associated flow-choking characteristics in poppet valves

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第6期25卷 455-469页

作者： Liang LU Zhongdong LIANG Yuming LIU Zhipeng WANG shohei RYU School of Mechanical Engineering Tongji UniversityShanghai 201804China Frontiers Science Center for Intelligent Autonomous Systems Tongji UniversityShanghai 201210China Technical Research Laboratory Hitachi Construction Machinery Co.Ltd.Tsuchiura 300-0013Japan

Poppet valves have become increasingly significant in ensuring precise digital flow rate and pressure control in hydraulic systems,necessitating a more profound understanding of the geometrical properties of cavitation in them,as well as associated flow-choking *** a comparative analysis with experimentally observed cavity images,we found that large eddy simulation(LES)turbulence modeling effectively replicates the geometrical properties of cavitation in these *** analysis demonstrated that cavitation is generated from vortices that result from the interaction between the notch contracta flow and the surrounding fluid *** in the internal or external vena contracta conditions result in fixed or discrete cavities,and the length-to-diameter ratio serves as a measure of the transition between internal and external vena contracta flow *** study establishes a threshold length-to-diameter ratio of approximately 2 for the tested poppet *** specifically,in notch structures with a smaller valve opening,longer sealing length,and smaller throttling angle(corresponding to a larger length-to-diameter ratio),the liquid-to-vapor transfer process is more evident than that in the reverse direction.A long-standing vapor cavity becomes fixed inside the notch,leading to a more pronounced flow-choking *** contrast,for structures with a smaller length-to-diameter ratio,the cavitation process for discrete vapor cavities is more complete,ensuring fluid flow continuity and significantly reducing the occurrence of the flow-choking phenomenon.

关键词： Poppet valves Vena contracta Vortex flow Vapor cavity Flow-choking

锥阀漩涡空化几何形态变迁与流量饱和特性（英文）

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第6期 455-469页

作者：陆亮梁中栋刘禹明王志鹏 shohei RYU 同济大学机械与能源工程学院同济大学教育部自主智能无人系统前沿科学中心日立建机株式会社技术研究实验室

目的：伴随数字阀在流体控制中日益体现的高端品质，锥阀作为数字阀的主要阀芯结构，其空化与流量饱和问题日益受到重视。本文借助实验与仿真手段，旨在揭示漩涡空化成形机理及其伴随孔口长径比形态变迁的物理规律，以及大尺度空化对流... 详细信息

目的：伴随数字阀在流体控制中日益体现的高端品质，锥阀作为数字阀的主要阀芯结构，其空化与流量饱和问题日益受到重视。本文借助实验与仿真手段，旨在揭示漩涡空化成形机理及其伴随孔口长径比形态变迁的物理规律，以及大尺度空化对流量饱和的影响特性，为高品质锥阀结构设计提供基础依据。创新点：1.应用流束收缩理论定义锥阀固定型与离散型空化的漩涡成型机理与形态变迁规律；2.使用大涡模拟合理复现空化形态并揭示空化对流量饱和的影响规律。方法：1.通过可视化实验，获得锥阀空化的几何形态，并验证数值模型的合理性；2.通过数值计算，研究空化形态随锥阀结构的变化规律；3.利用阀口开度、密封长度和阀芯半锥角三个参数定义长径比无量纲指标，衡量空化形态与流量饱和特性的变化规律。结论：1.锥阀阀口流束内外收缩性质的不同，导致阀口内部固定漩涡与阀口下游离散漩涡的差异，进而形成固定漩涡空化和离散漩涡空化的形态区别。2.使用阀口开度、密封长度和阀芯半锥角定义阀口等效长径比，可用于评价空化几何形态的变迁规律。3.固定漩涡空化对流量饱和的影响程度较大；离散漩涡空化因完整的溃灭过程而对流量饱和影响较小。

关键词：锥阀流束收缩漩涡流动蒸汽空穴流量饱和

“互联网+”集中群组干预模式在孕晚期初产妇中的应用研究

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中华护理教育 2023年第8期20卷 957-962页

作者：胡颖周明芳陈世华钟俊雅范尧俞丽丽大城昌平顾寿智重庆城市管理职业学院智慧康养学院重庆市401331 重庆医科大学附属第三医院妇产中心重庆医科大学公共卫生学院圣隶克里斯托弗大学康复学院日本静冈县滨松市433-8558

目的探讨“互联网+”集中群组干预模式(远程团体产前教育模式)对孕晚期初产妇孕产期心理的影响。方法招募120例定期在院胎心监护室检查的孕晚期初产妇,随机分为试验组(n=60)与对照组(n=60),两组均给予医院常规健康教育(每次产前检查时... 详细信息

目的探讨“互联网+”集中群组干预模式(远程团体产前教育模式)对孕晚期初产妇孕产期心理的影响。方法招募120例定期在院胎心监护室检查的孕晚期初产妇,随机分为试验组(n=60)与对照组(n=60),两组均给予医院常规健康教育(每次产前检查时的医护宣教、助产士门诊健康宣教等),在此基础上,对照组给予孕妇学校的线下孕晚期课程;试验组则给予以孕晚期保健知识、分娩应对、临产指导、产后护理为核心内容的“互联网+”集中群组保健模式的干预。试验组59例初产妇、对照组57例初产妇完成了研究。比较干预前后两组初产妇的妊娠压力及分娩期望。结果干预后,试验组的妊娠压力总均分为0.53(0.26,0.70),对照组的为0.70(0.35,1.13),差异有统计学意义(Z=2.233,P=0.026);试验组的医疗环境、配偶支持因子得分高于对照组(P<0.05)。结论运用“互联网+”集中群组干预模式对孕晚期初产妇进行远程教育,能降低孕妇的产前妊娠压力,提高其对医疗环境与配偶支持的分娩期望,是线下健康教育的有益补充。

关键词：孕妇同侪集群健康教育教育,远程

Effects of elafibranor on liver fibrosis and gut barrier function in a mouse model of alcohol-associated liver disease

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World Journal of Gastroenterology 2024年第28期30卷 3428-3446页

作者： Aritoshi Koizumi Kosuke Kaji Norihisa Nishimura shohei Asada Takuya Matsuda Misako Tanaka Nobuyuki Yorioka Yuki Tsuji Koh Kitagawa Shinya Sato Tadashi Namisaki Takemi Akahane Hitoshi Yoshiji Department of Gastroenterology Nara Medical UniversityKashihara 634-8521Japan

BACKGROUND Alcohol-associated liver disease(ALD)is a leading cause of liver-related morbidity and mortality,but there are no therapeutic targets and modalities to prevent ALD-related liver *** proliferator activated receptor(PPAR)α and δ play a key role in lipid metabolism and intestinal barrier homeostasis,which are major contributors to the pathological progression of ***,elafibranor(EFN),which is a dual PPARαand PPARδagonist,has reached a phase III clinical trial for the treatment of metabolic dysfunctionassociated steatotic liver disease and primary biliary ***,the benefits of EFN for ALD treatment is *** To evaluate the inhibitory effects of EFN on liver fibrosis and gut-intestinal barrier dysfunction in an ALD mouse *** ALD-related liver fibrosis was induced in female C57BL/6J mice by feeding a 2.5% ethanol(EtOH)-containing Lieber-DeCarli liquid diet and intraperitoneally injecting carbon tetrachloride thrice weekly(1 mL/kg)for 8 ***(3 and 10 mg/kg/day)was orally administered during the experimental *** and molecular analyses were performed to assess the effect of EFN on steatohepatitis,fibrosis,and intestinal barrier *** EFN effects on HepG2 lipotoxicity and Caco-2 barrier function were evaluated by cell-based *** The hepatic steatosis,apoptosis,and fibrosis in the ALD mice model were significantly attenuated by EFN *** promoted lipolysis and β-oxidation and enhanced autophagic and antioxidant capacities in EtOH-stimulated HepG2 cells,primarily through PPARα***,EFN inhibited the Kupffer cell-mediated inflammatory response,with blunted hepatic exposure to lipopolysaccharide(LPS)and toll like receptor 4(TLR4)/nuclear factor kappa B(NF-κB)*** improved intestinal hyperpermeability by restoring tight junction proteins and autophagy and by inhibiting apoptosis and proinflammatory *** protective effect on intestinal bar

关键词： Liver fibrosis Ethanol Gut barrier function Apoptosis Autophagy Peroxisome proliferator activated receptor

Himalayas as a global hot spot of springtime stratospheric intrusions:Insight from isotopic signatures in sulfate aerosols

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Research in Cold and Arid Regions 2024年第1期16卷 5-13页

作者： Kun Wang ShiChang Kang Mang Lin PengFei Chen ChaoLiu Li XiuFeng Yin shohei Hattori Teresa L.Jackson JunHua Yang YiXi Liu Naohiro Yoshida Mark HThiemens State Key Laboratory of Cryospheric Science Northwest Institute of Eco-Environment and ResourcesChinese Academy of Sciences(CAS)LanzhouGansu 730000China State Key Laboratory of Isotope Geochemistry Guangzhou Institute of GeochemistryCASGuangzhouGuangdong 510640China University of Chinese Academy of Sciences Beijing 100049China International Center for Isotope Effects Research(ICIER) School of Earth Sciences and EngineeringNanjing UniversityNanjingJiangsu 210023China Frontiers Science Center for Critical Earth Material Cycling State Key Laboratory for Mineral Deposits ResearchSchool of Earth Sciences and EngineeringNanjing UniversityNanjingJiangsu 210023China Department of Chemical Science and Engineering School of Materials and Chemical TechnologyTokyo Institute of Technology4259 Nagatsuta-choMidori-kuYokohamaKanagawa 226-8502Japan Department of Chemistry and Biochemistry University of California San DiegoLa JollaCA 92093-0021USA Earth-Life Science Institute Tokyo Institute of TechnologyMeguro-kuTokyo 152-8551Japan National Institute of Information and Communications Technology KoganeiTokyo 184-8795Japan

Downward transport of stratospheric air into the troposphere(identified as stratospheric intrusions)could potentially modify the radiation budget and chemical of the Earth's surface *** the highest and largest plateau on earth,the Tibetan Plateau including the Himalayas couples to global climate,and has attracted widespread attention due to rapid warming and cryospheric *** studies recognized strong stratospheric intrusions in the Himalayas but are poorly understood due to limited direct evidences and the complexity of the meteorological dynamics of the third ***^(35)S is a radioactive isotope predominately produced in the lower stratosphere and has been demonstrated as a sensitive chemical tracer to detect stratospherically sourced air mass in the planetary boundary ***,we report 6-month(April–September 2018)observation of^(35)S in atmospheric sulfate aerosols(^(35)SO_(4)^(2-))collected from a remote site in the Himalayas to reveal the stratospheric intrusion phenomenon as well as its potential impacts in this *** the sampling campaign,the^(35)SO_(4)^(2-)concentrations show an average of 1,070±980 atoms/m^(3).In springtime,the average is 1,620±730 atoms/m^(3),significantly higher than the global existing data measured so *** significant enrichments of^(35)SO_(4)^(2-)measured in this study verified the hypothesis that the Himalayas is a global hot spot of stratospheric intrusions,especially during the springtime as a consequence of its unique geology and atmospheric *** combined with the ancillary evidences,e.g.,oxygen-17 anomaly in sulfate and modeling results,we found that the stratospheric intrusions have a profound impact on the surface ozone concentrations over the study region,and potentially have the ability to constrain how the mechanisms of sulfate oxidation are affected by a change in plateau atmospheric properties and *** study provides new observational constraints on stra

关键词： Himalayas Stratospheric intrusions Cosmogenic^(35)SO_(4)^(2-) Ozone Atmospheric oxidation

A preliminary study on rectal dose reduction associated with hyaluronic acid implantation in brachytherapy for prostate cancer

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Asian Journal of Urology 2024年第2期11卷 286-293页

作者： Tairo Kashihara Yuka Urago Hiroyuki Okamoto Mihiro Takemori Hiroki Nakayama shohei Mikasa Tetsu Nakaichi Kotaro Iijima Takahito Chiba Junichi Kuwahara Satoshi Nakamura Weishan Chang Yoshiyuki Matsui Hiroshi Igaki Department of Radiation Oncology National Cancer Center Hospital5-1-1 TsukijiChuo-kuTokyoJapan Radiation Safety and Quality Assurance Division National Cancer Center Hospital5-1-1 TsukijiChuo-kuTokyoJapan Department of Radiological Sciences Graduate School of Human Health SciencesTokyo Metropolitan University7-2-10 Higashi-OguArakawa-kuTokyoJapan Department of Radiological Technology National Cancer Center Hospital5-1-1 TsukijiChuo-kuTokyoJapan Department of Urological Oncology National Cancer Center Hospital5-1-1 TsukijiChuo-kuTokyoJapan

Objectives: Hydrogel spacer (HS) was developed to reduce rectal toxicities caused by radiotherapy, but has been reported to cause major adverse events. Our institute has attempted to introduce a hyaluronic acid (HA) as an alternative spacer. This study aimed to compare rectal doses and geometric distributions between the HS and HA implantation in prostate ***: HS and HA were inserted in 20 and 18 patients undergoing high-dose brachytherapy, respectively. The rectum spacer volumes injected were 10 mL and 22 mL, respectively. In the treatment planning system, 13.5 Gy was administered with common catheter positions. The rectal dose indices were assessed between the spacer groups for dosimetry evaluation. Distances between the prostate and rectum and configurations of the spacers were ***: The mean doses irradiated to 0.1 and 2 mL of the rectum were 10.45 Gy and 6.71 Gy for HS, and 6.73 Gy and 4.90 Gy for HA (p<0.001). The mean minimum distances between the prostate and rectum were 1.23 cm and 1.79 cm for HS and HA, respectively (p<0.05). Geometrical configuration comparisons revealed that HA has a higher ability to expand the space than ***: The rectal dose reduction ability of HA is significantly greater than that of HS, suggesting its potential as a new spacer.

关键词： Brachytherapy Hyaluronicacid Hydrogel Prostaticneoplasm Radiotherapy

孕晚期“互联网+”集中群组化保健课程的构建

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中华护理教育 2021年第9期18卷 855-859页

作者：胡颖周明芳范尧俞丽丽大城昌平顾寿智圣隶克里斯托弗大学康复学院日本静冈县滨松市433-8558 重庆医科大学附属第三医院重庆医科大学公共卫生管理学院

目的构建针对孕晚期孕妇的“互联网+”集中群组化保健课程,为开展孕晚期孕妇线上健康教育提供参考。方法通过查阅文献及专家论证,初步形成孕晚期“互联网+”集中群组化保健课程相关内容,并于2020年2月—6月,运用德尔菲法对北京、上海、... 详细信息

目的构建针对孕晚期孕妇的“互联网+”集中群组化保健课程,为开展孕晚期孕妇线上健康教育提供参考。方法通过查阅文献及专家论证,初步形成孕晚期“互联网+”集中群组化保健课程相关内容,并于2020年2月—6月,运用德尔菲法对北京、上海、四川、湖南、湖北、重庆6个省份的临床、教学领域的专家进行2轮函询。结果2轮函询问卷的回收率分别为94%和100%,专家权威系数为0.863;专家意见协调系数分别为0.33、0.58(均P<0.05),变异系数为0.02~0.21。最终课程包括4个模块(一级条目)、18个项目(二级条目)。结论“互联网+”集中群组化孕晚期保健课程具有很好的科学性及可靠性,可用于孕晚期孕妇的线上健康教育。

关键词：孕妇教育远程同侪集群课程

Utility of plasma D-dimer for diagnosis of venous thromboembolism after hepatectomy

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World Journal of Clinical Cases 2024年第2期12卷 276-284页

作者： Taiichiro Miyake Hiroaki Yanagimoto Daisuke Tsugawa Masayuki Akita Riki Asakura Keisuke Arai Toshihiko Yoshida Shinichi So Jun Ishida Takeshi Urade Yoshihide Nanno Kenji Fukushima Hidetoshi Gon shohei Komatsu Sadaki Asari Hirochika Toyama Masahiro Kido Tetsuo Ajiki Takumi Fukumoto Division of Hepato-Biliary-Pancreatic Surgery Department of SurgeryKobe University Graduate School of MedicineKobe 650-0017HyogoJapan

BACKGROUND Venous thromboembolism(VTE)is a potentially fatal complication of *** use of postoperative prophylactic anticoagulation in patients who have undergone hepatectomy is controversial because of the risk of postoperative ***,we hypothesized that monitoring plasma D-dimer could be useful in the early diagnosis of VTE after *** To evaluate the utility of monitoring plasma D-dimer levels in the early diagnosis of VTE after *** The medical records of patients who underwent hepatectomy at our institution between January 2017 and December 2020 were retrospectively *** were divided into two groups according to whether or not they developed VTE after hepatectomy,as diagnosed by contrast-enhanced computed tomography and/or ultrasonography of the lower *** factors,including demographic data and perioperative D-dimer values,were compared between the two *** operating characteristic curve analysis was performed to determine the D-dimer cutoff *** and multivariate analyses were performed using logistic regression analysis to identify significant *** In total,234 patients who underwent hepatectomy were,of whom(5.6%)were diagnosed with VTE following hepatectomy.A comparison between the two groups showed significant differences in operative time(529 vs 403 min,P=0.0274)and blood loss(530 vs 138 mL,P=0.0067).The D-dimer levels on postoperative days(POD)1,3,5,7 were significantly higher in the VTE group than in the non-VTE *** the multivariate analysis,intraoperative blood loss of>275 mL[odds ratio(OR)=5.32,95%confidence interval(CI):1.05-27.0,P=0.044]and plasma D-dimer levels on POD 5≥21μg/mL(OR=10.1,95%CI:2.04-50.1,P=0.0046)were independent risk factors for VTE after *** Monitoring of plasma D-dimer levels after hepatectomy is useful for early diagnosis of VTE and may avoid routine prophylactic anticoagulation in the

关键词： Hepatectomy Malignant tumor Postoperative complication D-dimer Early diagnosis Venous thromboembolism

Broadly tunable lens-coupled nonlinear quantum cascade lasers in the sub-THz to THz frequency range

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Photonics Research 2022年第3期10卷 703-710页

作者： Kazuue Fujita shohei Hayashi Akio Ito Tatsuo Dougakiuchi Masahiro Hitaka Atsushi Nakanishi Central Research Laboratory Hamamatsu Photonics K.K.5000 HirakuchiHamakita WardHamamatsu 434-8601Japan

Room-temperature terahertz(THz)quantum cascade laser sources with intracavity difference-frequency nonlinear mixing are electrically pumped monolithic semiconductor laser sources operating in the 0.6–6 THz spectral *** report widely tunable,low-frequency THz quantum cascade laser sources using a lens-coupled Cherenkov waveguide *** on a watt-class high-power,λ∼13.7μm quantum cascade laser,the monolithic THz source is strongly coupled with a high-resistivity silicon lens,which causes a major increase in the THz coupling efficiency and demonstrates significant performance improvements.A room-temperature 1.5 THz device produces a 0.2 mW peak output power with a high-quality beam *** THz outcoupling efficiency using the lens-coupled scheme enabled the demonstration of a high-performance external-cavity semiconductor THz source that is tunable from 420 GHz to 2 *** external-cavity,lens-coupled device configuration can technically be assembled into a butterfly-style package for a thumb-sized,widely frequency tunable THz semiconductor source.

关键词： tunable waveguide pumped