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Effect of a disposable endoscope precleaning kit in the cleaning procedure of gastrointestinal endoscope:A multi-center observational study 被引量:1
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作者 Yi-Fan Wang Yu Wu +10 位作者 Xiao-Wei Liu Jian-Guo Li Yan-Qiong Zhan Bin Liu Wen-Ling Fan Zi-Heng Peng Jin-Tao Xiao Bing-Bing Li Jian He Jun Yi Zhao-Xia Lu 《World Journal of Gastrointestinal Endoscopy》 2023年第12期705-714,共10页
BACKGROUND Precleaning is a key step in endoscopic reprocessing.AIM To develop an effective and economic endoscope cleaning method by using a disposable endoscope bedside precleaning kit.METHODS Altogether,228 used ga... BACKGROUND Precleaning is a key step in endoscopic reprocessing.AIM To develop an effective and economic endoscope cleaning method by using a disposable endoscope bedside precleaning kit.METHODS Altogether,228 used gastrointestinal endoscopes were selected from five high-volume endoscopy units and precleaned by a traditional precleaning bucket(group T)or a disposable endoscope bedside precleaning kit(group D).Each group was further subdivided based on the replacement frequency of the cleaning solution,which was replaced every time in subgroups T1 and D1 and every several times in subgroups Ts and Ds.The adenosine triphosphate(ATP)level and residual proteins were measured three times:Before and after precleaning and after manual cleaning.RESULTS After precleaning,the precleaning kit significantly reduced the ATP levels(P=0.034)and has a more stable ATP clearance rate than the traditional precleaning bucket.The precleaning kit also saved a quarter of the cost of enzymatic detergent used during the precleaning process.After manual cleaning,the ATP levels were also significantly lower in the precleaning kit group than in the traditional precleaning bucket group(P<0.05).Meanwhile,the number of uses of the cleaning solution(up to four times)has no significant impact on the cleaning effect(P>0.05).CONCLUSION Considering its economic cost and cleaning effect,the use of a disposable endoscope bedside precleaning kit can be an optimal option in the precleaning stage with the cleaning solution being replaced several times in the manual cleaning stage. 展开更多
关键词 Cleaning effect Economic cost ENDOSCOPE multi-center study Precleaning
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Theoretical study of(e,2e) triple differential cross section of 1b3g orbital of ethylene by vibrational multi-center distorted-wave method
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作者 王振鹏 宫毛毛 +2 位作者 李星宇 张松斌 陈向军 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第11期306-312,共7页
The vibrational motions are usually neglected when calculating(e,2e) triple differential cross sections(TDCSs) of molecules. Here, multi-center distorted-wave method(MCDW) has been modified by including molecular vibr... The vibrational motions are usually neglected when calculating(e,2e) triple differential cross sections(TDCSs) of molecules. Here, multi-center distorted-wave method(MCDW) has been modified by including molecular vibrations. This vibrational MCDW method is employed to calculate the TDCSs of 1b3gorbital of ethylene at low(100 eV) and medium(250 eV) incident electron energies in coplanar asymmetric kinematic condition. The results show that molecular vibrations significantly influence the angular distributions of the TDCSs, especially in the binary region along momentum transfer near the Bethe ridge. 展开更多
关键词 (e 2e) multi-center distorted-wave method(MCDW) vibrational effect
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CLINICAL REPORT ON MULTI-CENTER RANDOMIZED CONTROLLED TRIAL OF TREATMENT OF MIGRAINE BY ELECTRO-ACUPUNCTURE AT QI■X■(丘墟GB40) 被引量:1
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作者 贾春生 马小顺 +10 位作者 石晶 王耀民 李永方 袁军 李梅 郑利星 张祥建 王少锦 高建英 李晓峰 霍永利 《World Journal of Acupuncture-Moxibustion》 2008年第1期1-9,共9页
Objective To observe the therapeutic effect of electro acupuncture at QIǖXǖ(丘墟GB40) for treating migraine and provide clinical study for Acupoints Dictionary of People's Republic of China. Methods Multi-center ... Objective To observe the therapeutic effect of electro acupuncture at QIǖXǖ(丘墟GB40) for treating migraine and provide clinical study for Acupoints Dictionary of People's Republic of China. Methods Multi-center (3 First-Class hospitals) study was adopted, and the involved 3 hospitals did clinical observation according to the requirements of the project. The methods are as follows. All cases were randomized into treatment group and control group according to their sequence. QIǖXǖ(丘墟GB40) was selected in treatment group, while Tiānshū (天枢 ST25) was selected in control group. Both groups were performed electro acupuncture, and syndromes indexes of migraine and 5-HT were observed before and after treatment. All data were analyzed by statistic software SPSS11.5. Results There was significant difference of VAS margin between two groups in each center and the combined center (u= -3. 362, P=0. 001 ). There was significant difference of therapeutic effect of 4-week treatment between two groups in each clinical center and the combined center. The therapeutic effect of 3-month treatment between two groups in No. 1 and No. 3 hospitals, showed significant difference, the treatment group was better; while that of No. 2 hospital had no obvious difference. The therapeutic effect of 6-month treatment between two groups in each center and the combined center had significant difference, the treatment group was better. Conclusion The therapy of electro acupuncture at QIǖXǖ(丘墟GB40) is effective for migraine. 展开更多
关键词 QIǖXǖ(丘墟GB40) Electro acupuncture Migraine multi-center clinical observation
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Probing the structure of multi-center molecules with odd–even high harmonics 被引量:4
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作者 Ning Su Shujuan Yu +2 位作者 Weiyan Li Shiping Yang Yanjun Chen 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第5期274-280,共7页
We study high-order harmonic generation(HHG)from multi-center asymmetric linear molecules numerically and analytically.Our simulations show that odd and even HHG spectra of the asymmetric multi-center system respond d... We study high-order harmonic generation(HHG)from multi-center asymmetric linear molecules numerically and analytically.Our simulations show that odd and even HHG spectra of the asymmetric multi-center system respond differently to the change of the molecular structure.Specifically,when the internuclear distances between these nuclei of the molecule have a small change,the odd spectra usually do not change basically,but the even spectra differ remarkably.Based on this phenomenon,a simple procedure is proposed to probe the positions of these nuclei with odd–even HHG.Our results shed light on attosecond probing of the structure of multi-center molecules using HHG. 展开更多
关键词 odd-even harmonics multi-center asymmetric molecules molecular structure
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Minimum MSE Weights of Adjusted Summary Estimator of Risk Difference in Multi-Center Studies 被引量:1
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作者 Chukiat Viwatwongkasem Jirawan Jitthavech +1 位作者 Dankmar Bohning Vichit Lorchirachoonkul 《Open Journal of Statistics》 2012年第1期48-59,共12页
The simple adjusted estimator of risk difference in each center is easy constructed by adding a value c on the number of successes and on the number of failures in each arm of the proportion estimator. Assessing a tre... The simple adjusted estimator of risk difference in each center is easy constructed by adding a value c on the number of successes and on the number of failures in each arm of the proportion estimator. Assessing a treatment effect in multi-center studies, we propose minimum MSE (mean square error) weights of an adjusted summary estimate of risk difference under the assumption of a constant of common risk difference over all centers. To evaluate the performance of the proposed weights, we compare not only in terms of estimation based on bias, variance, and MSE with two other conventional weights, such as the Cochran-Mantel-Haenszel weights and the inverse variance (weighted least square) weights, but also we compare the potential tests based on the type I error probability and the power of test in a variety of situations. The results illustrate that the proposed weights in terms of point estimation and hypothesis testing perform well and should be recommended to use as an alternative choice. Finally, two applications are illustrated for the practical use. 展开更多
关键词 Minimum MSE WEIGHTS Optimal WEIGHTS Cochran-Mantel-Haenszel WEIGHTS Inverse Variance WEIGHTS multi-center STUDIES Risk Difference
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External blast flow field evolution and response mechanism of single-layer reticulated dome structure 被引量:3
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作者 Shao-bo Qi Guang-yan Huang +1 位作者 Xu-dong Zhi Feng Fan 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第6期241-253,共13页
Single-layer reticulated dome structure are commonly high-profile building in the public and can be attractive targets for terrorist bombings,so the public can benefit from enhanced safety with a stronger understandin... Single-layer reticulated dome structure are commonly high-profile building in the public and can be attractive targets for terrorist bombings,so the public can benefit from enhanced safety with a stronger understanding of the behavior of single-layer reticulated dome structure under explosion.This paper investigates the fluid-structure interaction process and the dynamic response performance of the singlelayer reticulated dome under external blast load.Both experimental and numerical results shown that structural deformation is remarkably delayed compared with the velocity of blast wave,which advises the dynamic response of large-span reticulated dome structure has a negligible effect on the blast wave propagation under explosion.Four failure modes are identified by comparing the plastic development of each ring and the residual spatial geometric of the structure,i.e.,minor vibration,local depression,severe damage,and overall collapse.The plastic deformation energy and the displacement potential energy of the structure are the main consumers of the blast energy.In addition,the stress performance of the vertex member and the deep plastic ratio of the whole structure can serve as qualitative indicators to distinguish different failure modes. 展开更多
关键词 External blast loading Reticulated dome structure Fluid-structure interaction Dynamic response mode Response mechanism
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南极Dome A地区低温低压环境下智能照明控制技术探索
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作者 李仲元 郝洛西 汪统岳 《照明工程学报》 2023年第3期106-112,共7页
南极内陆Dome A地区极端恶劣的环境对科考人员的生理极限及作业效率构成了严峻挑战,而无人观测站可突破人类生理限制,持续高效工作,其关键运维技术,包括智能照明控制技术等越发受到各国重视。本文在总结Dome A地区遥远、低温、极夜、白... 南极内陆Dome A地区极端恶劣的环境对科考人员的生理极限及作业效率构成了严峻挑战,而无人观测站可突破人类生理限制,持续高效工作,其关键运维技术,包括智能照明控制技术等越发受到各国重视。本文在总结Dome A地区遥远、低温、极夜、白化天等不利影响因素的基础上,探索适应该区域极端环境、满足科考人员工作需求、便于远程及现场操作的智能照明系统运维模式,进行满足极昼极夜环境下无人观测站室内监测及维护需求的智能照明适宜技术选型。通过对铱星传输模块、Wi-Fi无线网关等子系统的组合,提出可耐受Dome A地区低温低压环境的现场照明监控设备控制方案,对南极无人站区的建设及相关智能照明控制技术的发展具有指导意义。 展开更多
关键词 dome A 无人观测站 智能照明控制技术 铱星传输模块 Wi-Fi无线网关
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Theoretical study of (e,2e) triple differential cross sections of pyrimidine and tetrahydrofurfuryl alcohol molecules using multi-center distorted-wave method
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作者 Yiao Wang Zhenpeng Wang +2 位作者 Maomao Gong Chunkai Xu Xiangjun Chen 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第1期118-123,共6页
We report theoretical studies of electron impact triple differential cross sections of two bio-molecules,pyrimidine and tetrahydrofurfuryl alcohol,in the coplanar asymmetric kinematic conditions with the impact energy... We report theoretical studies of electron impact triple differential cross sections of two bio-molecules,pyrimidine and tetrahydrofurfuryl alcohol,in the coplanar asymmetric kinematic conditions with the impact energy of 250 eV and ejected electron energy of 20 eV at three scattering angles of-5°,-10°,and-15°.Present multi-center distorted-wave method well describes the experimental data,which was obtained by performing(e,2e)experiment.The calculations show that the secondary electron produced by the primary impact electron is strongly influenced by the molecular ionic multi-center potential,which must be considered when the low energy electron interacts with DNA analogues. 展开更多
关键词 (E 2E) bio-molecules multi-center distorted-wave method(MCDW)
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Multi-Order and Multi-Center Metallogenic Zoning of Yinshan Cu-Au Polymetallic Ore Deposit,Jiangxi Province,China
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作者 Mo Cehui Liu Danying Feng Zhiwen Xia WeflwaChina University of Geosciences , Wuhan 430074 《Journal of Earth Science》 SCIE CAS CSCD 1993年第1期70-73,共4页
Yinshan anticline is the product of tectono-dynamic deformation - metamorphism .Along the axis of the anticline exists a brittle-ductile shearing zone which obviously controls the ore-formation . Mineralization occurs... Yinshan anticline is the product of tectono-dynamic deformation - metamorphism .Along the axis of the anticline exists a brittle-ductile shearing zone which obviously controls the ore-formation . Mineralization occurs along the axis of the anticline in a width of about 1000m .In the mining area .volcano- subvolcanic rocks of Early Yanshan period are divided into three cycles :Ⅰ intermediate acidic dacite lava and dacite porphyry ;Ⅱ acidic amphibole liparite and quartz porphyry;Ⅲ intermediate andesite porphyrite . Among them activities of ⅠandⅡ cycles are more intensive and are intimately related to the mineralization . Yinshan ore deposit is the result of combinative processes of tectono -dynamic and volcano -magmatic hydrothermal fluids, so that mere are two centers of metallogenic zoning, one being the axial strain zone of Yinshan anticline which is the center of first order, and the other being porphyry stock , 2nd order. 展开更多
关键词 Yinshan polymetallic deposit multi-order and multi-center metallogenic zoning brittle-ductile shearing zone porphyry stock .
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The Volume Effect and Safety of 6% Hydroxyethyl Starch 130/0.4 in Patients Undergoing Major Elective Surgery: An Uncontrolled, Open-Labeled, Multi-Center Study
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作者 Nobutada Morioka Makoto Ozaki +6 位作者 Michiaki Yamakage Hiroshi Morimatsu Yasuyuki Suzuki Frank Bepperling Hideki Miyao Akiyoshi Namiki Kiyoshi Morita 《Open Journal of Anesthesiology》 2013年第7期326-337,共12页
Purpose: The primary aim of this study was to investigate volume effect and safety of up to 50 mL/kg BW 6% hydroxyethyl starch (HES) 130/0.4 in adult and pediatric patients undergoing major elective surgery. The need ... Purpose: The primary aim of this study was to investigate volume effect and safety of up to 50 mL/kg BW 6% hydroxyethyl starch (HES) 130/0.4 in adult and pediatric patients undergoing major elective surgery. The need to infuse human albumin may be reduced or avoided in Japan if these large doses 6% HES 130/0.4 can be infused. Methods: The study was an uncontrolled, open-labeled, multi-center trial. Fifteen adult and 5 pediatric patients undergoing major elective surgery received 6% HES 130/0.4 (Voluven&#174) with a maximum dose of 50 mL/kg from the start of surgery until 2 hours after the end of surgery according to a treatment algorithm. The primary efficacy endpoint was the volume effect of 6% HES 130/0.4 determined by the volume of saved albumin during the investigational period and the time course of hemodynamic stability in adult and pediatric patients. Safety parameters were fluid balance, hemodynamic and laboratory parameters ECG, local and systemic tolerance and adverse events. Results: Adult patients received a mean of 32.0 mL/kg of 6% HES 130/0.4. For 12 out of 15 adult patients an average amount of 1033.8 mL (18.6 mL/kg) albumin could be saved. The other 3 adult patients did not receive more than 1000 mL of HES 130/0.4. All pediatric patients received approximately 50 mL/kg of HES 130/0.4;for these patients an average amount of 39.9 mL/kg body weight albumin could be saved. The majority of adult patients, and all pediatric patients were hemodynamically stable at all 3 time points. The observed changes of the assessed laboratory parameters including hematological and coagulation parameters or in any other safety parameter determined did not reveal any safety concern related to the administration of 6% HES 130/0.4 up to doses of 50 mL/kg body weight. Conclusion: The study results indicate that 6% HES 130/0.4 has a reliable volume effect, could contribute to significant human albumin savings and was safe and well tolerated up to a maximum dose of 50 mL/kg body weight in adult and pediatric patients undergoing major elective surgery. 展开更多
关键词 High DOSE Volume Effect SAFETY 6% Hydroxyethyl STARCH 130/0.4 ELECTIVE Surgery multi-center Study
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青少年高度近视Dome征伴黄斑区视网膜下积液的多模式影像特征
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作者 王若宜 赵玥 姚进 《国际眼科杂志》 CAS 北大核心 2023年第11期1920-1924,共5页
目的:观察青少年高度近视圆顶样黄斑(简称Dome征)伴黄斑区视网膜下积液(SRF)的多模式影像特征,探讨其典型特征与鉴别方法。方法:回顾性研究。选取2021-01/2022-05于我院确诊为高度近视Dome征伴黄斑区SRF的青少年患者21例39眼,行彩色眼... 目的:观察青少年高度近视圆顶样黄斑(简称Dome征)伴黄斑区视网膜下积液(SRF)的多模式影像特征,探讨其典型特征与鉴别方法。方法:回顾性研究。选取2021-01/2022-05于我院确诊为高度近视Dome征伴黄斑区SRF的青少年患者21例39眼,行彩色眼底照相(CFP)、眼底自发荧光(FAF)、频域光学相干断层扫描(SD-OCT)、光学相干断层扫描血管成像(OCTA)及眼电图(EOG)检查,其中18例36眼患者行荧光素眼底血管造影(FFA)检查,随访12mo,记录中心凹下视网膜厚度(CMT)变化情况。结果:眼底检查可见患眼均呈高度近视豹纹状改变,中心凹可见颗粒样物质沉积;SD-OCT检查显示黄斑区全层呈圆顶样隆起,中心凹下神经上皮层局限性脱离,外界膜内表面可见中高反射附着,视网膜色素上皮(RPE)层反射不均匀;FAF检查显示黄斑区呈轻度“牛眼征”改变;FFA检查显示黄斑区拱环周围环绕颗粒状透见荧光;OCTA检查的En face图中可见清晰的神经上皮脱离区边界,切线对应椭圆体带-RPE分层面,可见神经上皮脱离区内散在大小不一的颗粒状高反射,未见明显脉络膜新生血管(CNV)形成,OCTA检查随访可见黄斑区SRF可存在无规律的自行增多或吸收;EOG检查显示光峰与暗谷(LP/DT,或称Arden比)比值正常,均>1.55。基线、随访1、3、6、12mo,纳入患者CMT(246.95±11.46、247.10±13.03、246.62±12.23、248.05±14.00、247.92±11.66μm)无显著差异(F=0.144,P=0.965)。结论:多模式影像检查有助于青少年高度近视Dome征伴黄斑区SRF的临床诊断,并且在与典型Best病病变前期的鉴别诊断中发挥重要作用。 展开更多
关键词 病理性近视 圆顶样黄斑(dome征) 视网膜下积液 卵黄样黄斑营养不良 光相干断层扫描血管成像 影像特征
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Sensitivity analysis and probability modelling of the structural response of a single-layer reticulated dome subjected to an external blast loading
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作者 Shao-bo Qi Guang-yan Huang +1 位作者 Xu-dong Zhi Feng Fan 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第5期152-163,共12页
The structural response of a single-layer reticulated dome to external explosions is shaped by many variables,and the associated uncertainties imply non-deterministic results.Existing deterministic methods for predict... The structural response of a single-layer reticulated dome to external explosions is shaped by many variables,and the associated uncertainties imply non-deterministic results.Existing deterministic methods for predicting the consequences of specific explosions do not account for these uncertainties.Therefore,the impact of the uncertainties associated with these input variables on the structures’response needs to be studied and quantified.In this study,a parametric uncertainty analysis was conducted first.Then,local and global sensitivity analyses were carried out to identify the drivers of the structural dynamic response.A probabilistic structural response model was established based on sensitive variables and a reasonable sample size.Furthermore,some deterministic empirical methods for explosion-resistance design,including the plane blast load model of CONWEP,the curved blast load model under the 50%assurance level,and the 20%mass-increased method,were used for evaluating their reliability.The results of the analyses revealed that the structural response of a single-layer reticulated dome to an external blast loading is lognormally distributed.Evidently,the MB0.5 method based on the curved reflector load model yielded results with a relatively stable assurance rate and reliability,but CONWEP did not;thus,the 1.2MB0.5 method can be used for making high-confidence simple predictions.In addition,the results indicated that the structural response is very sensitive to the explosion parameters.Based on these results,it is suggested that for explosion proofing,setting up a defensive barrier is more effective than structural strengthening. 展开更多
关键词 dome structure Blast load uncertainty Sensitivity analysis Probabilistic investigation Reliability evaluation
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Xi-Feng-Hua-Shi granules for diarrhea-predominant irritable bowel syndrome:protocol for a randomized,double-blind,placebo-controlled multi-center clinical trial
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作者 Hui Li Kai-Li Luo +13 位作者 Dan Wang Yun Huang Xiao-Mei Xu Xue Zou Ren-Jing Qiu Ting Chen Chuan-Wang Zhu Jie Li Yong-Shuang Wang Han-Lin Wang Zu Yang Yong-Yue Wei Yao-Zhou Tian Xu-Dong Tang 《Clinical Research Communications》 2022年第2期15-21,共7页
Background:Irritable bowel syndrome(IBS)is a common functional bowel disorder that can severely affect the quality of life of patients.Limited drugs have been reported for modern medical IBS treatment.The advantages o... Background:Irritable bowel syndrome(IBS)is a common functional bowel disorder that can severely affect the quality of life of patients.Limited drugs have been reported for modern medical IBS treatment.The advantages of traditional Chinese medicine(TCM)treatment are gradually becoming prominent.Xi-Feng-Hua-Shi granules have been clinically used for diarrhea-predominant IBS(IBS-D)treatment for many years in TCM practice.Thus,this study aimed to further verify the effectiveness and safety of Xi-Feng-Hua-Shi(XFHS)granules in IBS-D treatment through a randomized,double-blind,placebo-controlled multi-center clinical trial and provide high-quality evidence for its effectiveness and safety in treatment,as well as provide a basis for clinical rational drug use and explore new clinical IBS-D treatment plans.Methods:A randomized,double-blind,placebo-controlled multi-center clinical trial will be performed in 23 hospitals.A total of 300 participants will be randomly divided into the experimental group(prescribed with XFHS granules)and the control group(prescribed with the placebo granules),with 150 participants in each group.The appearance,shape,color,and taste of the placebo granules are the same as those of XFHS granules.All participants will receive a 4-week treatment and a 6-month follow-up.The primary outcome is the overall clinical efficacy;the secondary outcomes are the IBS-Symptom Severity Score(IBS-SSS),TCM Syndrome Evaluation,and the IBS-Quality of Life(IBS-QoL)score,mental state assessment,and recurrence rate.Outcome measures(including primary and secondary outcome measures)are collected at baseline,as well as 2,4,16,and 28 weeks post-intervention.Discussion:This randomized,placebo-controlled,multi-center trial may provide high-quality evidence for the clinical XFHS granule efficacy in IBS-D treatment.Additionally,this study will conduct safety evaluations to provide a basis for clinical rational drug use. 展开更多
关键词 Xi-Feng-Hua-Shi granules diarrhea-predominant irritable bowel syndrome Randomized double-blind placebo-controlled multi-center clinical trial protocol
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Minimally invasive perventricular VSD closure without cardiopulmonary bypass mid-term results from multi-centers
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作者 邢泉生 《外科研究与新技术》 2011年第3期170-171,共2页
Objective Transesophageal echocardiography (TEE) guided,minimally invasive perventricular device occlusion of ventricular septal defects (VSDs) without cardiopulmonary bypass (CPB) has been applied in multiple centers... Objective Transesophageal echocardiography (TEE) guided,minimally invasive perventricular device occlusion of ventricular septal defects (VSDs) without cardiopulmonary bypass (CPB) has been applied in multiple centers. We reported experiences and the mid-term results. Methods Four hundred and thirty-two cases from 4 cardiac centers were involved in the study. There were 235 maled and 197 females,aged from 3 months to 15 years,with a body weight varying from 4.0 to 26.0 kg. 展开更多
关键词 VSD Minimally invasive perventricular VSD closure without cardiopulmonary bypass mid-term results from multi-centers
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大跨度索穹顶结构半主动振动控制分析 被引量:1
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作者 韩庆华 张晓龙 +1 位作者 芦燕 罗奇星 《东南大学学报(自然科学版)》 EI CAS CSCD 北大核心 2024年第1期17-24,共8页
为了实现大跨空间结构半主动振动控制,提出了一种基于模糊控制算法的半主动振动控制方法.以某体育馆大跨度索穹顶屋盖为分析对象,建立了基于台站与地震信息的地震动记录选择集,采用研发的新型压电摩擦阻尼器,开展索穹顶结构被动控制研究... 为了实现大跨空间结构半主动振动控制,提出了一种基于模糊控制算法的半主动振动控制方法.以某体育馆大跨度索穹顶屋盖为分析对象,建立了基于台站与地震信息的地震动记录选择集,采用研发的新型压电摩擦阻尼器,开展索穹顶结构被动控制研究.将地面加速度和结构变形量2个指标作为控制参数,进行索穹顶结构半主动振动控制分析.结果表明:被动控制时不同地震动强度下结构峰值加速度、最大相对变形量的最小减振率平均值仅分别为3.7%和-1.6%;半主动控制下的压电摩擦阻尼器能够适应不同强度地震动,有效降低结构的峰值加速度和峰值位移,且峰值加速度减振率平均值为20.0%~41.9%,最大相对变形量减振率平均值为12.0%~19.0%. 展开更多
关键词 压电摩擦阻尼器 索穹顶 半主动控制 地震响应 模糊控制
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南极冰穹A的天文台址测量进展 被引量:1
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作者 商朝晖 胡义 《极地研究》 CAS CSCD 北大核心 2024年第1期1-11,共11页
越来越多的观测证据表明,昆仑站所在的冰穹A地区在光学、红外和太赫兹等波段都有着地面最佳的天文观测条件。它具有优异的自由大气视宁度,极低的可沉降水汽含量,非常暗的夜天光背景,以及连续数月的极夜可观测时间等。通过对最近17年的... 越来越多的观测证据表明,昆仑站所在的冰穹A地区在光学、红外和太赫兹等波段都有着地面最佳的天文观测条件。它具有优异的自由大气视宁度,极低的可沉降水汽含量,非常暗的夜天光背景,以及连续数月的极夜可观测时间等。通过对最近17年的工作总结,着重介绍冰穹A全面的台址测量工作,并展示测量结果以及最新的进展。 展开更多
关键词 天文 选址 光学 红外 冰穹A
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基于向量式有限元的网壳结构地震易损性分析 被引量:1
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作者 曲激婷 宋嘉诚 霍林生 《世界地震工程》 北大核心 2024年第1期96-106,共11页
为解决网壳结构地震易损性研究中,增量动力分析(incremental dynamic analysis,IDA)所面临的结构非线性分析耗时长且求解困难的问题,提出了一种基于向量式有限元的IDA方法。首先,以一个Kiewitt-8型单层球面网壳为例,验证了向量式有限元... 为解决网壳结构地震易损性研究中,增量动力分析(incremental dynamic analysis,IDA)所面临的结构非线性分析耗时长且求解困难的问题,提出了一种基于向量式有限元的IDA方法。首先,以一个Kiewitt-8型单层球面网壳为例,验证了向量式有限元方法求解结构地震响应的准确性,其次选取12个不同参数的Kiewitt-8型单层球面网壳为研究对象,并考虑材料不确定性进行IDA分析,以地震峰值加速度与结构最大节点位移比为参数,绘制了结构在地震作用下的IDA曲线和轻微破坏、严重破坏及倒塌这三种性态下的易损性曲线。结果表明:向量式有限元能高效且准确的求解网壳结构的地震响应,屋面质量和矢跨比的增加均会增加三种性态点的超越概率;对于本文的网壳结构算例,求解时间仅为传统有限元方法的1/15,误差在3%以内,屋面质量和矢跨比的改变导致地震危险性最大增加了75%。 展开更多
关键词 增量动力分析 单层球面网壳 向量式有限元法 非线性分析 地震易损性分析
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交替提升与张拉的索穹顶结构施工优化方法
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作者 姜正荣 苏延 +3 位作者 石开荣 李之吉 魏德敏 梁霖 《西南交通大学学报》 EI CSCD 北大核心 2024年第3期663-669,共7页
为确保索穹顶结构施工成型前索杆内力的平稳变化,提出了交替提升内拉环与张拉最外圈斜索的施工优化方法.首先,以施工过程中的平均结构应变能最小为优化目标,对内拉环的逐级提升高度进行优化;其次,通过仿真分析得到施工过程中的索杆内力... 为确保索穹顶结构施工成型前索杆内力的平稳变化,提出了交替提升内拉环与张拉最外圈斜索的施工优化方法.首先,以施工过程中的平均结构应变能最小为优化目标,对内拉环的逐级提升高度进行优化;其次,通过仿真分析得到施工过程中的索杆内力和节点位移,并与仅张拉最外圈斜索的施工方法进行对比.结果表明:交替提升内拉环与张拉最外圈斜索的施工优化方法可有效减小施工过程中的索杆内力,降幅最大达61.83%,避免了施工成型前索杆内力的大幅波动,且结构位形变化较平缓,相邻施工步的竖向位移差最大为1.43 m,平均结构应变能较低,仅为55.03%,优化效果显著,验证了该优化方法对索穹顶结构施工模拟的适用性. 展开更多
关键词 索穹顶结构 交替提升与张拉 施工仿真 施工优化
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江西彭山穹隆构造成因及地质意义
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作者 史洪峰 刘明军 +2 位作者 孙强 朱延辉 张景 《东华理工大学学报(自然科学版)》 CAS 北大核心 2024年第4期301-311,共11页
为探讨彭山穹隆成因及时代,在彭山地区开展了野外地质调查、构造解析和年代学等研究工作。结果表明,彭山穹隆为构造穹隆,形态为短轴背斜,其及周边存在稳定的印支期近SN向古构造应力场,伴生NNE向走滑断层,其东侧发育东倾的逆断层。切穿... 为探讨彭山穹隆成因及时代,在彭山地区开展了野外地质调查、构造解析和年代学等研究工作。结果表明,彭山穹隆为构造穹隆,形态为短轴背斜,其及周边存在稳定的印支期近SN向古构造应力场,伴生NNE向走滑断层,其东侧发育东倾的逆断层。切穿穹隆的断层被霏细斑岩脉贯入,霏细斑岩脉的锆石U-Pb年龄为(123.0±1.0) Ma,隐伏黑云母花岗岩的U-Pb年龄为(123.0±1.4) Ma,古应力场同期断层中断层泥的伊利石K-Ar年龄为(228.1±10.3)~(233.2±6.5) Ma,因此认为彭山穹隆形成时间为印支期或更早。 展开更多
关键词 穹隆 构造年代学 江南造山带 彭山
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考虑下部结构单层球面网壳的地震动参数与易损性分析
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作者 韩庆华 孙明阳 徐杰 《地震工程与工程振动》 CSCD 北大核心 2024年第3期29-40,共12页
目前大跨空间球面网壳结构的地震动参数研究与易损性分析多关注于上部结构,忽视了下部支承体系对整体结构的影响。为选取适于评估带下部结构肋环斜杆型单层球面网壳响应的地震动参数,以6个不同矢跨比、不同下部结构的单层球面网壳为模型... 目前大跨空间球面网壳结构的地震动参数研究与易损性分析多关注于上部结构,忽视了下部支承体系对整体结构的影响。为选取适于评估带下部结构肋环斜杆型单层球面网壳响应的地震动参数,以6个不同矢跨比、不同下部结构的单层球面网壳为模型,研究下部支承体系对球面网壳动力特性的影响,选取多条三维地震动作为输入对模型进行增量动力分析,从相关性、有效性和充分性三个方面对18个地震动参数进行分析评估。并基于大量算例失效时刻的特征响应,建立了考虑下部结构的单层球面网壳的地震损伤模型。结果表明:有无下部支承对结构基频影响较大,随着下部结构高度的增加,结构基频不断减小,无支承柱结构与带10 m支承柱结构的基频相差高达24%;加速度谱强度、峰值加速度与结构地震响应的相关性、有效性及充分性均优于其它地震动参数,可作为考虑下部结构肋环斜杆型单层球面网壳易损性分析的地震动参数。与此同时,在下部支承结构相同时,矢跨比小的网壳结构抗震性能更好,所致结构倒塌的临界荷载更大;支承高度对网壳抗震性能的影响并非呈线性关系,因此,在结构设计时应合理选取下部支承结构高度。 展开更多
关键词 下部结构 肋环斜杆型 球面网壳 地震动参数 损伤模型 易损性分析
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