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A Versatile Flow-Profile Engineering Method in the Stokes Flow Regime for Complex-Shaped Flows

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Engineering 2021年第5期7卷 655-662页

作者： Zhenyu Yang lang nan Ho Cheung Shum Department of Mechanical Engineering The University of Hong KongHong Kong 999077China

Flow profiles are frequently engineered in microfluidic channels for enhanced mixing,reaction control,and material ***,flow profiles are engineered by inducing inertial secondary flow to redistribute the streams,which can hardly be reproduced in microfluidic environments with negligible inertial *** employed symmetric channel structures also limit the variety of achievable flow ***,each of the flow profiles specifically corresponds to a strictly defined flow condition and cannot be generalized to other flow *** address these issues,we present a systematic method to engineer the flow profile using inertialess secondary *** flow is manipulated in the Stokes regime by deploying a cascaded series of microsteps with various morphologies inside a microchannel to shape the flow *** tuning the shapes of the microsteps,arbitrary outflow profiles can be customized.A numerical profile-transformation program is developed for rapid prediction of the output profiles of arbitrary sequences of predefined *** proposed method allows the engineering of stable flow profiles,including asymmetric ones,over a wide range of flow conditions for complex microfluidic environmental prediction and design.

关键词： Microfluidics Flow profile Stokes flow Hydrodynamic focusing Flow shaping

Oil-mediated high-throughput generation and sorting of water-in-water droplets

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Microsystems & nanoengineering 2020年第1期6卷 484-493页

作者： lang nan Yang Cao Shuai Yuan Ho Cheung Shum Department of Mechanical Engineering The University of Hong KongPokfulam RoadHong KongChina Department of Electrical and Electronic Engineering The University of Hong KongPokfulam RoadHong KongChina

Aqueous two-phase system(ATPS)droplets have demonstrated superior compatibility over conventional water-in-oil droplets for various biological ***,the ultralow interfacial tension hampers efficient and stable droplet generation,limiting further development and more extensive use of such ***,we present a simple strategy to employ oil as a transient medium for ATPS droplet *** methods based on passive flow focusing and active pico-injection are demonstrated to generate water-water-oil double emulsions,achieving a high generation frequency of~2.4 *** evaporation of the oil to break the double emulsions,the aqueous core can be released to form uniform-sized water-in-water ***,this technique can be used to fabricate aqueous microgels,and the introduction of the oil medium enables integration of droplet sorting to produce single-cell-laden hydrogels with a harvest rate of over 90%.We believe that the demonstrated high-throughput generation and sorting of ATPS droplets represent an important tool to advance droplet-based tissue engineering and single-cell analyses.

关键词： limiting sized compatibility

A new potential risk factor in patients with erectile dysfunction and premature ejaculation： folate deficiency

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Asian Journal of Andrology 2014年第6期16卷 902-906页

作者： Wen-Jie Yan nan Yu Tai-lang Yin Yu-]ie Zou Jing Yang Reproductive Medical Center Renmin Hospital of Wuhan University Wuhan China.

We investigated serum folic acid （FA） levels in patients with erectile dysfunction （ED） and/or premature ejaculation （PE）. Fasting serum samples were obtained from 42 patients with ED, 36 with PE, 25 ED patients with PE, and 30 healthy men; the mean intravaginal ejaculation latency time （IELT） was measured during a 4 weeks baseline period. Levels of sex hormones （follicle-stimulating hormone, luteinizing hormone, total testosterone）, homocysteine （Hcys）, and FA were measured using chemiluminescent immunoassays. The sexual functions of PE patients and normal control men were evaluated using the Chinese Index of Premature Ejaculation （CIPE）. The abridged Intemational Index of Erectile Function-5 （IIEF-5） questionnaire was used to gauge erectile quality for ED patients and for normal controls. Serum FA concentrations were lower in ED （7.61 ~ 3.97 ng ml-1）, PE （9.37 ＋ 3.40 ng ml-1）, and ED/PE （8.84 ＋ 4.28 ng m1-1） patients than in healthy men （12.23 ~ 5.76 ng ml-z, P〈 0.05）. No significant differences in sex hormone levels were found between patients with sexual dysfunction and healthy controls （P 〉 0.05）. There were positive correlations between serum FA concentrations and ClPE scores （r= 0.530, P〈 0.01）, IIEF-5 scores （r= 0.589, P〈 0.01）, and IELT （r= 0.445, P〈 0.01）; negative correlations with Hcys concentrations （r= -0.487, P〈 0.01） were found in all participants. These findings showed a strong relationship between serum FA levels and sexual dysfunction, possibly due to an effect of FA on the metabolism of nitric oxide, Hcys, and 5-hydroxytryptamine.

关键词： 5-hydroxytryptamine erectile dysfunction folic acid homocysteine nitric oxide premature ejaculation

Can Vitamin D supplementation be used as adjunctive treatment for oligozoospermia or asthenozoospermia accompanied with Vitamin D deficiency？

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Asian Journal of Andrology 2015年第1期17卷 165-167页

作者： Wen-Jie Yan nan Yu Tai-lang Yin Liu Liu Jing Yang Reproductive Medical Center Renmin Hospital of Wuhan University Wuhan 430060Hubei China.

Dear Editor, We read the paper by Hammoud et al. in the issue of Asian Journal of Andrology with great interests. This paper revealed that sperm concentration, sperm progressive motility, sperm morphology, and total progressively motile sperm count were lower in men with 25（OH） D 〉 50 ng ml-1 when compared with men with 20 ng m1-1 -〈 25（OH） D 〈 50 ng ml-2. Total sperm count and total progressive motile sperm count were lower in men with 25（OH） D 〈 20 ng ml-1 when compared to men with 20 ng ml 1-〈 25（OH） D 〈 50 ng ml-1. Therefore, they draw the conclusion that serum Vitamin D （VD） levels at high and low levels can be negatively associated with semen parameters.

关键词： Can Vitamin supplementation adjunctive treatment

A Foodborne Bongkrekic Acid Poisoning Incident--Heilongjiang Province,2020

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China CDC weekly 2020年第51期2卷 975-978页

作者： Yuan Yuan Rui Gao Qiang Liang Li Song Jun Huang nan lang Jing Zhou National Institute for Occupational Health and Poison Control China CDCBeijingChina Chinese Center for Disease Control and Prevention BeijingChina Jixi Center for Disease Control and Prevention Jixi CityHeilongjiang ProvinceChina The Second Hospital of Heilongjiang Province HarbinChina

What is already known on this topic?Poisoning incidents caused by bongkrekic acid(BA),one of the metabolites of Burkholderia gladioli pathovar cocovenenans(***),have been reported in Indonesia,Mozambique,and *** reported case fatality rates averaged 60%,32%,and 26.5%,*** China,*** is often called Pseudomonas cocovenenans *** is added by this report?In October 2020,9 persons in Jidong County,Heilongjiang Province died after consuming a homemade fermented corn flour product—sour soup—with a case fatality rate of 100%.BA was detected in both food samples and biological samples with a content of 330 mg/kg and 3 mg/L,*** doses of BA consumed by the cases were approximately 22-33 times the lethal dose in *** are the implications for public health practice?The consumption of fermented corn flour products,deteriorated fresh tremella,or black fungus and metamorphic starch products may cause BA *** education should be strengthened so that homemade-starch-fermented food should be avoided and foods that have been kept for a long time should not be ***,training and emergency capacity building for primary healthcare workers should be strengthened to provide timely diagnosis and response.

关键词： strengthened consuming Heilongjiang

中国股市高频波动率的特征、预测模型以及预测精度比较

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系统工程理论与实践 2013年第2期33卷 296-307页

作者：陈浪南杨科中山大学岭南学院经济研究所广州510275 华南农业大学经济管理学院广州510642

在HAR-GARCH模型和HAR-CJ模型的基础上构建了自适应的不对称性HAR-CJ-DFIGARCH模型,并用以对中国股市高频波动率进行了预测,然后利用上证综指2000年至2008年的高频数据实证检验了中国股市高频波动率的特征,最后运用SPA检验评价和比较了... 详细信息

在HAR-GARCH模型和HAR-CJ模型的基础上构建了自适应的不对称性HAR-CJ-DFIGARCH模型,并用以对中国股市高频波动率进行了预测,然后利用上证综指2000年至2008年的高频数据实证检验了中国股市高频波动率的特征,最后运用SPA检验评价和比较了构建的模型与其他6类高频波动率模型的样本外预测能力.结果表明:中国股市高频波动率同时具有长记忆性、结构突变、不对称性和周内效应等特征;结构突变仅部分解释其长记忆性;高频波动率连续性成分的长记忆性很强,而跳跃性成分的长记忆性非常弱.相比于其他6类模型,自适应的不对称性HAR-CJ-D-FIGARCH模型对样本内数据的拟合效果最好,同时也是样本外预测性能最好的模型.

关键词：高频波动率预测自适应的不对称性HAR-CJ—D—FIGARCH模型 SPA检验

人民币汇率波动影响我国外汇储备变动的理论模型和实证研究

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系统工程理论与实践 2012年第7期32卷 1452-1463页

作者：陈浪南黄寿峰中山大学岭南学院经济研究所广州510275 厦门大学财政系厦门361005

本文在综合考虑国际收支和外汇储备需求的基础上构建了人民币汇率波动影响外汇储备的理论模型,并利用相关数据实证检验了人民币汇率波动对外汇储备的影响.模型结果表明:规模变量、进口倾向、国外收入及汇率因素对外汇储备需求的影响取... 详细信息

本文在综合考虑国际收支和外汇储备需求的基础上构建了人民币汇率波动影响外汇储备的理论模型,并利用相关数据实证检验了人民币汇率波动对外汇储备的影响.模型结果表明:规模变量、进口倾向、国外收入及汇率因素对外汇储备需求的影响取决于这些变量各自对外汇储备瞬时变化的确定性部分μ的影响.实证结果表明:长期上,规模变量、进口倾向、名义有效汇率、实际有效汇率对外汇储备变动都具有显著正效应;而储备增长自身波动、实际有效汇率波动及汇率制度对外汇储备变动均呈明显负影响;国外收入、中美实际利差、名义有效汇率波动对外汇储备变动的影响不明显.短期内,名义有效汇率及实际有效汇率变动对外汇储备变动都呈明显负效应,国外收入具有显著正影响,而其它变量的变化对外汇储备影响不明显.

关键词：人民币汇率外汇储备随机存货模型

Mushroom Poisoning Outbreaks -China, 2022

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China CDC weekly 2023年第3期5卷 45-50,I0001-I0005页

作者： Haijiao Li Yizhe Zhang Hongshun Zhang Jing Zhou Jiaqi Liang Yu Yin Qian He Shaofeng Jiang Yutao Zhang Yuan Yuan nan lang Bowen Cheng Mei Wang Chengye Sun National Institute of Occupational Health and Poison Control Chinese Center for Disease Control and PreventionBeijingChina

Mushroom poisoning has become a serious food safety issue in *** the support of the government,over the past decade,China has gradually established a mushroom poisoning prevention and treatment system involving experts in disease prevention and control,clinical diagnosis and treatment,fungal classification,and basic medicine(1–3).

关键词： prevention diagnosis treatment

Mushroom Poisoning Outbreaks — China, 2021

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China CDC weekly 2022年第3期4卷 35-40,I0001-I0003页

作者： Haijiao Li Hongshun Zhang Yizhe Zhang Jing Zhou Yu Yin Qian He Shaofeng Jiang Peibin Ma Yutao Zhang Yuan Yuan nan lang Bowen Cheng Mei Wang Chengye Sun National Institute of Occupational Health and Poison Control Chinese Center for Disease Control and PreventionBeijingChina

Summary What is already known about this topic?Mushroom poisoning is one of the most serious food safety issues in *** poisoning incidents resulted from eating mushrooms causing gastroenteritis and psycho-neurological disorder from which patients usually could fully *** deaths resulted from species causing acute liver failure and rhabdomyolysis,and the remaining deaths were attributed to acute renal failure and *** is added by this report?In 2021,the total number of investigations was 327 from 25 provincial-level administrative divisions,involving 923 patients and 20 deaths,and the overall mortality was 2.17%.Overall,74 poisonous mushrooms causing 6 different clinical syndromes were successfully identified,15 of which were newly recorded in China as poisonous *** are the implications for public health practice?Considering the potential huge risks for collecting and eating wild mushrooms,we strongly advise not collecting and eating unfamiliar wild *** knowledge about poisonous mushrooms is essential and urgent to reduce mushroom *** species identification timely after mushroom poisoning is important for appropriate diagnosis and *** deaths were ascribed to delayed hospitalization.

关键词： diagnosis attributed poisoning