期刊文献+
共找到76,621篇文章
< 1 2 250 >
每页显示 20 50 100
Association of anxiety- depressive disorders with irritable bowel syndrome among patients attending a rural family practice center: a comparative cross- sectional study 被引量:2
1
作者 Alaa Adel Mohammed Heba Ahmed Moustafa +1 位作者 Hebatallah Nour-Eldein Rabab Atta Saudi 《General Psychiatry》 CSCD 2021年第6期16-23,共8页
Background Comorbidity of irritable bowel syndrome(IBS)and psychiatric disorders is common,and the prevalence of at least one psychiatric disorder has been reported as high as 80%among patients with IBS.Aims To explor... Background Comorbidity of irritable bowel syndrome(IBS)and psychiatric disorders is common,and the prevalence of at least one psychiatric disorder has been reported as high as 80%among patients with IBS.Aims To explore the association of anxiety-depressive disorders with IBS and its different subtypes,and to evaluate the associations of lifestyle habits,dietary habits and sleeping quality with IBS.Methods A comparative cross-sectional study was conducted at the AL-Mahsama Family Practice Center,Ismailia,Egypt.It was carried out between October 2019 and October 2020.Participants were categorised into 175 patients with IBS,diagnosed using the Rome IV criteria,and 175 patients without IBS.A semistructured questionnaire was used to collect data on sociodemographic characteristics,lifestyle habits,dietary habits and sleep quality from both groups.The Hamilton Anxiety Rating Scale was used to assess anxiety symptoms,whereas the Beck Depression Inventory Second Edition was used to assess depression symptoms.Results There was a high statistically significant difference between both groups with regard to age,education,occupation and socioeconomic status(SES),being a smoker,being physically inactive,having sleep disturbance and having irregular meals;being either obese or overweight was more reported in the IBS group.There was a high statistically significant difference in the rate of anxiety and depression between patients with and without IBS.Mild,moderate and severe anxiety were reported in 37.1%,42.9%and 20.0%of patients with IBS while most(80.0%)of the patients without IBS reported mild anxiety.Regarding depression,mild,moderate and severe depression were reported in 60.0%,14.3%and 25.7%of the patients with IBS while most(82.9%)of the non-IBS participants reported mild depression.Conclusions The study shows a significant association between anxiety-depressive disorders and IBS,but no significant associations between anxiety-depressive disorders and IBS subtypes. 展开更多
关键词 PATIENTS DISORDERS sectional
下载PDF
Dyslipidemia in Adults with Type 2 Diabetes in a Rural Community in Ganadougou, Mali: A Cross-Sectional Study
2
作者 Abdoulaye Diawara Djibril Mamadou Coulibaly +22 位作者 Drissa Kone Mama A. Traore Drissa Konaté Dicko S. Bazi Oumar Kassogue Djeneba Sylla Fatoumata Gniné Fofana Oudou Diabaté Mariam Traore Ibrahim Antoine Nieantao Kaly Keїta Mamadou Diarra Olivia Smith Jian Li Cheickna Cisse Talib Yusuf Abbas Crystal Zheng Segun Fatumo Kassim Traore Mamadou Wele Mahamadou Diakité Seydou O. Doumbia Jeffrey G. Shaffer 《Journal of Diabetes Mellitus》 CAS 2024年第2期133-152,共20页
Dyslipidemia is a disorder where abnormally lipid concentrations circulate in the bloodstream. The disorder is common in type 2 diabetics (T2D) and is linked with T2D comorbidities, particularly cardiovascular disease... Dyslipidemia is a disorder where abnormally lipid concentrations circulate in the bloodstream. The disorder is common in type 2 diabetics (T2D) and is linked with T2D comorbidities, particularly cardiovascular disease. Dyslipidemia in T2D is typically characterized by elevated plasma triglyceride and low high-density lipoprotein cholesterol (HDL-C) levels. There is a significant gap in the literature regarding dyslipidemia in rural parts of Africa, where lipid profiles may not be captured through routine surveillance. This study aimed to characterize the prevalence and demo-graphic profile of dyslipidemia in T2D in the rural community of Ganadougou, Mali. We performed a cross-sectional study of 104 subjects with T2D in Ganadougou between November 2021 and March 2022. Demographic and lipid profiles were collected through cross-sectional surveys and serological analyses. The overall prevalence of dyslipidemia in T2D patients was 87.5% (91/104), which did not differ by sex (P = .368). High low-density lipoprotein cholesterol (LDL-C) was the most common lipid abnormality (78.9%, [82/104]). Dyslipidemia was associated with age and hypertension status (P = .013 and.036, respectively). High total and high LDL-C parameters were significantly associated with hypertension (P = .029 and .006, respectively). In low-resource settings such as rural Mali, there is a critical need to improve infrastructure for routine dyslipidemia screening to guide its prevention and intervention approaches. The high rates of dyslipidemia observed in Gandadougou, consistent with concomitant increases in cardiovascular diseases in Africa suggest that lipid profile assessments should be incorporated into routine medical care for T2D patients in African rural settings. 展开更多
关键词 CHOLESTEROL cross-sectional Study DYSLIPIDEMIA LIPIDS MALI Type 2 Diabetes
下载PDF
Patterns of Infertility and Abortion in Saudi Arabia: A Cross-Sectional Study
3
作者 Majed Saeed Alshahrani 《Open Journal of Obstetrics and Gynecology》 2024年第6期911-922,共12页
Background: Infertility and abortion are significant reproductive health concerns globally, impacting individuals' well-being and healthcare systems. In Saudi Arabia, cultural, social, and religious factors influe... Background: Infertility and abortion are significant reproductive health concerns globally, impacting individuals' well-being and healthcare systems. In Saudi Arabia, cultural, social, and religious factors influence perceptions and management of these issues, necessitating research to understand the patterns and associated factors. Study Aim: This cross-sectional study aimed to investigate the patterns of infertility and abortion among 458 women in Saudi Arabia, focusing on demographic profiles, reproductive histories, medical conditions, and lifestyle factors. Methodology: Participants were recruited from healthcare facilities, and data on age, BMI, reproductive history, medical conditions, assisted reproduction methods, and lifestyle behaviors were collected. Statistical analyses, including chi-square tests, were conducted to examine associations between variables. Results: The majority of participants were aged 30 - 39 years (47.4%), with 76.9% experiencing secondary infertility. Among those with offspring (76.9%), 31% reported using assisted reproduction methods, primarily ovarian stimulators (54.2%). Abortion history was reported by 39.5% of participants. Significant associations were found between age and infertility type (X2 = 5.8, p = 0.054), having offspring and infertility type (X2 = 458.0, p = 0.001), menstrual irregularity and infertility type (X2 = 11.4, p = 0.001), and abortion history and delayed fertility (X2 = 10.4, p = 0.001). Conclusion: Our study reveals significant associations between demographic, medical, and lifestyle factors with infertility patterns and abortion history among Saudi women. These findings emphasize the need for tailored interventions addressing medical conditions, age-related factors, and access to reproductive healthcare services. 展开更多
关键词 INFERTILITY ABORTION Saudi Arabia Reproductive Health Assisted Reproduction cross-sectional Study
下载PDF
Associations of Perchlorate,Nitrate,and Thiocyanate with Sex Hormones among Children:A Nationally Representative Cross-sectional Study in U.S.
4
作者 Yiwen Wang Guodong Ding +1 位作者 Peipei Hu Yongjun Zhang 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2024年第6期666-671,共6页
Nitrates,thiocyanates,and perchlorates are ubiquitous in the environment and can be introduced to the public through various dietary and environmental sources.Nitrates,thiocyanates,and perchlorates mainly affect healt... Nitrates,thiocyanates,and perchlorates are ubiquitous in the environment and can be introduced to the public through various dietary and environmental sources.Nitrates,thiocyanates,and perchlorates mainly affect health via the same mechanism.These toxins may act as endocrine disrupters and can result in decreased levels of thyroid hormones^([1]). 展开更多
关键词 mechanism sectional PERCHLORATE
下载PDF
First Born Double Differential Cross-Section for Ionization of H (3d) by Incident Electron Impact
5
作者 Sushmita Banerjee Sunil Dhar 《Open Journal of Microphysics》 2024年第2期67-77,共11页
Double differential cross section (DDCS) of First-Born approximation is calcu-lated for the ionization of metastable 3d-state hydrogen atoms by electron impact energy at 150 eV and 250 eV. A multiple scattering theory... Double differential cross section (DDCS) of First-Born approximation is calcu-lated for the ionization of metastable 3d-state hydrogen atoms by electron impact energy at 150 eV and 250 eV. A multiple scattering theory is applied in the present study. The present results are compared with the other related the-oretical results for the ionization of hydrogen atoms from different metastable states and ground-state experimental results. The findings demonstrate a strong qualitative agreement with the existing results. The obtained results have an extensive scope for further study of such an ionization process. 展开更多
关键词 Electron IONIZATION cross-section SCATTERING
下载PDF
Correlation between psychological resilience and burnout among female employees in a shopping mall in Xi Xian new area,China:A cross-sectional survey-Retraction
6
《Journal of Integrative Nursing》 2024年第1期70-70,共1页
In the article titled“Correlation between psychological resilience and burnout among female employees in a shopping mall in Xi Xian New Area,China:A cross-sectional survey”by Zhang Q and Liu L(J Integr Nurs 2021;3(3... In the article titled“Correlation between psychological resilience and burnout among female employees in a shopping mall in Xi Xian New Area,China:A cross-sectional survey”by Zhang Q and Liu L(J Integr Nurs 2021;3(3):117-121.doi:10.4103/jin.jin_14_21),[1]the content and results data of this article was questioned by International database(Web of Science)institution.This article was then investigated by the publisher and Journal of Integrative Nursing(JIN). 展开更多
关键词 SHOPPING database sectional
下载PDF
Experimental and Numerical Investigation of the Performance of Turbulent Heat Transfer in Tubes with Different Cross-Sectioned Wire Coils
7
作者 Ali Shokor Golam 《Frontiers in Heat and Mass Transfer》 EI 2024年第2期633-653,共21页
The thermal-hydraulic performance of plain tubes with and without wire coils in turbulent regimes is investigated experimentally and numerically.The effects of wire coil distribution(circular cross section)within the ... The thermal-hydraulic performance of plain tubes with and without wire coils in turbulent regimes is investigated experimentally and numerically.The effects of wire coil distribution(circular cross section)within the tube were explored experimentally,and water was employed as the working fluid.The numerical simulation was carried out using software programmer ANSYS Fluent 2019 R3 using the finite-volume approach.In the turbulent regime,six cross-sectionedwire coilswere analyzed,including:circular,rectangular,hexagonal,square,star shape,and triangle.The utilization of a tube with a wire coil has been shown to increase heat transfer rate and pump consumption.The results indicate a high level of concurrence,as the deviations are all below 8%.Compared with plain tube,the wire coils,according to the arrangement(TWD),gave the best PEC.The heat transfer enhancement ability of different cross sections follows the following order:StCS>RCS>HCS>SqCS>CCS>TCS.Also,the sequence of pump consumption for each cross section is as follows:RCS>StCS>SqCS>HCS>CCS>TCS. 展开更多
关键词 Wire coil performance evaluation criterion friction factor circular tube cross section
下载PDF
Influence of Cross-Sectional Flow Area of Annular Volute Casing on Transient Characteristics of Ceramic Centrifugal Pump 被引量:5
8
作者 Yi Tao Shouqi Yuan +1 位作者 Jianrui Liu Fan Zhang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2019年第1期161-173,共13页
The annular volute is typically used in a slurry pump to reduce the collisions between solid particles and the volute tongue and to achieve a better resistance to blocking. However, only limited studies regarding annu... The annular volute is typically used in a slurry pump to reduce the collisions between solid particles and the volute tongue and to achieve a better resistance to blocking. However, only limited studies regarding annular volutes are available, and there is no systematic design method for annular volutes. In this study, the influence of volute casing cross-sectional flow area on the hydraulic loss, pressure pulsations, and radial force under varying working conditions in a centrifugal ceramic pump are discussed in detail. Experimental tests were conducted to validate the numerical results. The results indicated that, when the volute casing flow area increases, the hydraulic performance decreases marginally under the rated working conditions, but increases at the o-design points, specifically under large flow condition. However, the volute casing with a larger flow area has a wider high-e ciency region. In addition, the increase in the volute casing flow area will decrease the pressure pulsations in the volute, regardless of the working condition, and decrease the radial force on the shaft, therefore, providing an improved pump operational stability. It is anticipated that this study will be of benefit during the design of annular volutes. 展开更多
关键词 ANNULAR VOLUTE Centrifugal pump Cross section Transient characteristics Pressure PULSATION Radial force
下载PDF
A Cross-sectional Survey Assessing Carriage of Streptococcus pneumoniae in a Healthy Population in Xinjiang Uygur Autonomous Region of China 被引量:15
9
作者 XIE Na CHEN Zhao Yun +7 位作者 CHEN Tao ZHU Bing Qing XU Li GAO Yuan ZHANG Ai Yu ZHAO Pan LIU Ji Wen SHAO Zhu Jun 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2018年第3期233-237,共5页
The carriage rate and serotype distribution of Streptococcus pneumoniae(S.pneumoniae)in a healthy population in China remains unclear.In this study,we collected the oropharyngeal swabs from513 individuals in Xinjian... The carriage rate and serotype distribution of Streptococcus pneumoniae(S.pneumoniae)in a healthy population in China remains unclear.In this study,we collected the oropharyngeal swabs from513 individuals in Xinjiang,China.Real-time PCR targeting the lytA gene and 12 serotypes were assessed to identify S.pneumoniae carriage. 展开更多
关键词 cross-sectional survey Streptococcus pneumoniae carriage Real-time PCR XINJIANG China
下载PDF
Principle and Experimental Verification of Caudal-fin-type Piezoelectric-stack Pump with Variable-cross-section Oscillating Vibrator 被引量:12
10
作者 HU Xiaoqi ZHANG Jianhui +3 位作者 HUANG Yi XIA Qixiao HUANG Weiqing ZHAO Chunsheng 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2012年第1期128-136,共9页
In the traditional flow-resistance-differential (FRD) type valve-less piezoelectric pump, the generated outflow and pressure are discontinuous because of the inherent periodicity and fluctuation of the pump. To overco... In the traditional flow-resistance-differential (FRD) type valve-less piezoelectric pump, the generated outflow and pressure are discontinuous because of the inherent periodicity and fluctuation of the pump. To overcome these drawbacks, utilizing the bending vibration of piezoelectric bimorph to drive fluid was conducted. However, our investigation on the current status of this piezoelectric bimorph pump shows that larger driving force and vibration amplitude are required for fluid pumping; the pumping can be realized through the centrifugal force; and the mechanism of fluid pumping is no longer further studied. Based on these cases, the paper designed a piezoelectric-stack pump with variable-cross-section oscillating (VCSO) vibrator by imitating the swing of the caudal-fin of tuna, and the pump is neither the rotating type nor the volumetric type according to the taxonomy. The interaction between the oscillating vibrator and the fluid parcel is firstly analyzed from the viewpoint of momentum conservation, and the analytical expression of pump flow rate is obtained. Then the modal and harmonic response analyses on the vibrator immerged in water are carried out. From the analyses the first two orders resonance frequencies are 832 Hz and 1 939 Hz, respectively, and the peak value of the tip amplitude is 0.6 mm. Laser Doppler vibrometer is used to measure both the frequency and vibration amplitude, and the determined first two orders resonance frequencies are 617 Hz and 1 356 Hz, respectively. The measured tip amplitude reaches to the peak value of 0.3 mm. At last, experimental measurement for the flow rates with different driving frequencies is conducted. The results show that the flow rate can reach 560 mL/min at 1 370 Hz when the pump runs under the backpressure of 30 mm water column. And the flow rate is as much as 560% of that of experiment results carried out by researchers from Brazil. The proposed pump innovates in both theory and taxonomy; in addition, the pump overcomes the drawbacks such as large flow fluctuation and low flow rate in the traditional FRD type pumps, which will help to broaden the application of the valve-less piezoelectric pump. 展开更多
关键词 caudal-fin-type variable-cross-section piezoelectric-stack valve-less pump
下载PDF
Influences of the Helical Strake Cross-Section Shape on Vortex-Induced Vibrations Suppression for A Long Flexible Cylinder 被引量:10
11
作者 XU Wan-hai LUAN Ying-sen +1 位作者 LIU Li-qin WU Ying-xiang 《China Ocean Engineering》 SCIE EI CSCD 2017年第4期438-446,共9页
An experimental study on a bare flexible cylinder as well as cylinders fitted with two types of cross-sectioned helical strakes was carried out in a towing tank. The main purpose of this paper is to investigate the ef... An experimental study on a bare flexible cylinder as well as cylinders fitted with two types of cross-sectioned helical strakes was carried out in a towing tank. The main purpose of this paper is to investigate the effects of strakes’ cross-section on the vortex-induced vibrations (VIV) suppression of a flexible cylinder. The square-sectioned and round-sectioned helical strakes were selected in the experimental tests. The uniform current was generated by towing the cylinder models along the tank using a towing carriage. The Reynolds number was in the range of 800–16000. The strain responses were measured by the strain gages in cross-flow (CF) and in-line (IL) directions. A modal analysis method was adopted to obtain the displacement responses using the strain signals in different measurement positions. The comparison of the experimental results among the bare cylinder, square-sectioned straked cylinder and round-sectioned straked cylinder was performed. The helical strakes can effectively reduce the strain amplitude, displacement amplitude, response frequencies and dominant modes of a flexible cylinder excited by VIV. And the mean drag coefficients of straked cylinders were approximately consistent with each other. In addition, the square-sectioned and round-sectioned strakes nearly share the similar VIV reduction behaviors. Sometimes, the strakes with round-section represent more excellent effects on the VIV suppression of response frequency than those with square-section. 展开更多
关键词 helical strakes VIV suppression cross-section shape flexible cylinder
下载PDF
Relationship between sonographically measured median nerve cross-sectional area and presence of peripheral neuropathy in diabetic subjects 被引量:8
12
作者 Fredrick ANDrew Attah Christianah Mopelola Asaleye +3 位作者 Adeleye Dorcas Omisore Babatope Ayodeji Kolawole Adeniyi Sunday Aderibigbe Mathew Alo 《World Journal of Diabetes》 SCIE CAS 2019年第1期47-56,共10页
BACKGROUND Neuropathy is a common complication of diabetes mellitus resulting from direct damage by hyperglycemia to the nerves and/or ischemia by microvascular injury to the endoneurial vessels which supply the nerve... BACKGROUND Neuropathy is a common complication of diabetes mellitus resulting from direct damage by hyperglycemia to the nerves and/or ischemia by microvascular injury to the endoneurial vessels which supply the nerves. Median nerve is one of the peripheral nerves commonly affected in diabetic neuropathy. The median nerve size has been studied in non-Nigerian diabetic populations. In attempt to contribute to existing literature, a study in a Nigerian population is needed.AIM To evaluate the cross-sectional area(CSA) of the median nerve using B-mode ultrasonography(USS) and the presence of peripheral neuropathy(PN) in a cohort of adult diabetic Nigerians.METHODS Demographic and anthropometric data of 85 adult diabetes mellitus(DM) and 85 age-and sex-matched apparently healthy control(HC) subjects were taken. A complete physical examination was performed on all study subjects to determine the presence of PN and modified Michigan Neuropathy Screening Instrument(MNSI) was used to grade its severity. Venous blood was taken from the study subjects for fasting lipid profile(FLP), fasting blood glucose(FBG) and glycated haemoglobin(HbA1 c) while their MN CSA was evaluated at a point 5 cm proximal to(5 cmCATL) and at the carpal tunnel(CATL) by high-resolution Bmode USS. Data was analysed using SPSS version 22.RESULTS The mean MN CSA was significantly thicker in DM subjects compared to the HC at 5 cmCATL(P < 0.01) and at the CATL(P < 0.01) on both sides. The presence of diabetic peripheral neuropathy(DPN) further increased the MN CSA at the CATL(P < 0.05) but not at 5 cmCATL(P > 0.05). However, the severity of DPN had no additional effect on MN CSA 5 cm proximal to and at the CATL. There was no significant association between MN CSA and duration of DM and glycemic control.CONCLUSION Thickening of the MN CSA at 5 cmCATL and CATL is seen in DM. Presence of DPN is associated with worse thickening of the MN CSA at the CATL but not at5 cmCATL. Severity of DPN, duration of DM, and glycemic control had no additional effect on the MN CSA. 展开更多
关键词 MEDIAN nerve cross-sectionAL area SONOGRAPHY DIABETICS Peripheral NEUROPATHY
下载PDF
Awareness of and attitudes towards infertility and its treatment: a cross-sectional survey of men in a United States primary care population 被引量:7
13
作者 Robert S Gerhard Chad WM Ritenour +2 位作者 Michael Goodman Dipak Vashi Wayland Hsiao 《Asian Journal of Andrology》 SCIE CAS CSCD 2014年第6期858-863,共6页
Previous studies have described racial and socioeconomic disparities in the treatment of infertility. Patient factors such as attitudes and awareness may be contributing factors. Since primary care is often the settin... Previous studies have described racial and socioeconomic disparities in the treatment of infertility. Patient factors such as attitudes and awareness may be contributing factors. Since primary care is often the setting that serves as an entry into other areas of medicine, we sought to evaluate men's attitudes and awareness of male infertility in the primary care setting. To do this, we performed a cross-sectional survey of men's attitudes toward men's health issues in 210 men from two primary care clinic waiting rooms in Atlanta, Georgia. The survey was self-administered with closed-ended question items and was approximately 20 min in length. Of the 310 men approached, 210 agreed to participate and returned completed surveys. Overall, 52% of men said they were "very" or "somewhat" familiar with infertility and 25% were familiar with treatments for infertility. Some men had heard of surgery (21%) and medication (35%) as treatments for male infertility. Awareness and familiarity with the condition was greater in high socioeconomic status men (i.e. college graduates or those with income 〉$100 k per year) but did not differ by race on multivariate analysis. Attitudes toward infertility varied by race with non-Caucasian men being more likely to indicate that infertility is a serious condition, to be concerned about infertility, and to believe it decreases a man's quality-of-life. Therefore, a lack of awareness, but not negative attitudes, may contribute to previously-described disparities in the treatment of infertility. 展开更多
关键词 cross-sectional study health disparities INFERTILITY patient attitudes and awareness SURVEY
下载PDF
Nonfatal Child Pedestrian Injury in Two Urban Cities of Guangdong Province,China:Results from a Cross-sectional Survey 被引量:4
14
作者 MA WenJun NIE ShaoPing +3 位作者 XU HaoFeng XU YanJun XIE HuiYan ZHANG YuRun 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2011年第4期335-342,共8页
Objective To describe the epidemiological characteristics of nonfatal child pedestrian injuries and provide information to help understand an important public-health problem.Methods This was a school-based,cross-secti... Objective To describe the epidemiological characteristics of nonfatal child pedestrian injuries and provide information to help understand an important public-health problem.Methods This was a school-based,cross-sectional questionnaire survey.The sample (42 750 children) was obtained from two urban cities of Guangdong Province,China,using multi-stage randomized sampling.Information was collected by the respondents self-reporting in the classroom.Results The incidence rate of nonfatal child pedestrian injuries in the cities was 2.0%.Boys had a higher incidence rate (2.6%) than girls (1.4%).Compared to other children,those aged 10 years are at the highest risk.The primary places of occurrence were sidewalks,residential roads,and crosswalks.High-risk behavior of the children immediately prior to injury included mid-block crossings,playing on roads,and crossing on red lights.The major vehicles that caused pedestrian injuries were bicycles,car or vans,and motorcycles.Bruises,fractures,and injuries to the internal organs were the top three types of injuries.Almost 40% of victims were hospitalized,and nearly 30% of the victims suffered long-term disabilities.Conclusion This study shows that nonfatal child pedestrian injuries are a very serious public-health problem in the urban cities of Guangdong.Based on the epidemiological characteristics,prevention strategies and further research should be carried out to reduce the occurrence of injuries. 展开更多
关键词 CHILDREN PEDESTRIAN INJURY cross-sectional study
下载PDF
Tea Consumption is Associated with Increased Risk of Kidney Stones in Northern Chinese: A Cross-sectional Study 被引量:7
15
作者 WU Zhong Biao JIANG Tian +8 位作者 LIN Guo Bing WANG You Xin ZHOU Yong CHEN Zhen Qian XU Yong Ming YE Hai Bo CHEN Bo Jun BAO Xiao Zhao ZHANG Cun Ming 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2017年第12期922-926,共5页
Kidney stones are a common urinary system condition that can progress to kidney disease. Previous studies on the association between tea consumption and kidney stones are inconsistent. A cross-sectional study to inves... Kidney stones are a common urinary system condition that can progress to kidney disease. Previous studies on the association between tea consumption and kidney stones are inconsistent. A cross-sectional study to investigate the association between tea consumption and kidney stones was conducted from 2013 to 2014 and recruited 9,078 northern Chinese adults. A total of 8,807 participants were included in the final analysis. Participants' prevalence of kidney stones was 1.07%, 1.73%, and 2.25% based on their tea consumption frecluencv of never, occasionally, 展开更多
关键词 Increased Risk of Kidney Stones Northern Chinese cross-sectional Study
下载PDF
Dynamic caustics test of blast load impact on neighboring different cross-section roadways 被引量:6
16
作者 Guo Dongming Zhou Baowei +2 位作者 Liu Kang Yang Renshu Yan Pengyang 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2016年第5期803-808,共6页
Using digital laser dynamic caustics experimental system and conducting simulation experiment researched the influence rule of blasting excavation of a new roadway on neighboring existed different cross-section roadwa... Using digital laser dynamic caustics experimental system and conducting simulation experiment researched the influence rule of blasting excavation of a new roadway on neighboring existed different cross-section roadways. The experimental results show that the influence of blast load on adjacent roadway has a good relationship with the cross-section of roadway. The expansion distance of precrack existed in circular, arch-wall, rectangular roadway is respectively 1.76, 1.61 and 0 cm under blast load.At the same time, the direct-blast side of rectangular roadway has more obvious damage compared with circular and arch-wall roadway. It explains that plane reflects more stress wave than arc, so that it exerts more tensile failure in the direct-blast side, which leads to less stress wave diffracting to the precrack in the back-blast side. When the precrack extends, higher value dynamic stress intensity factor in circular roadway works longer than that of arch-wall roadway. Indirectly, it explains that plane's weakening function on stress wave is significantly stronger than arc. Stress wave brings about self-evident influence on the upper and bottom endpoints of the rectangular roadway, and it respectively extends 1.03, 2.06 cm along the line link direction of the center of the blasthole and the upper and bottom endpoints on the right wall. 展开更多
关键词 Dynamic caustics Blast load Different cross-section roadways Precrack Dynamic stress intensity factor
下载PDF
An analytical model for the prediction of cross-section profile and mean roll radius in alloy bar rolling 被引量:8
17
作者 Yonggang Dong Wenzhi Zhang Jianfeng Song 《Journal of University of Science and Technology Beijing》 CSCD 2008年第3期344-351,共8页
In a round-oval-round pass rolling sequence, the cross-section profile of an outgoing workpiece was predicted first after getting the maximum spread. The concept "critical point on the contact boundary" was proposed... In a round-oval-round pass rolling sequence, the cross-section profile of an outgoing workpiece was predicted first after getting the maximum spread. The concept "critical point on the contact boundary" was proposed and the coordinates of the critical point were solved. The equivalent contact section area was represented and the mean roll radius was determined. The validity of this model was examined by alloy bar rolling experiment and rigid-plastic FEM simulation. Compared with the existing models, the mean roll radius obtained by this model is similar to experiment data. 展开更多
关键词 alloy steel critical point cross-section profile mean roll radius round-oval-round
下载PDF
Deformation Calculation of Cross-section Based on Virtual Force in Thin-walled Tube Bending Process 被引量:5
18
作者 LIU Jingyao TANG Chengtong NING Ruxin 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2009年第5期696-701,共6页
Cross-section deformation is one of important factors affecting the quality of tube formation, and the tube's capability of transporting liquid and gas will be reduced because of the cross-section ellipse deformation... Cross-section deformation is one of important factors affecting the quality of tube formation, and the tube's capability of transporting liquid and gas will be reduced because of the cross-section ellipse deformation due to the effect of shear load in plastic bending process. When the tube is bent, the extrados-wall bears the tension stress and the intrados-wall bears the compression stress, synchronously the cross-section is affected by the circumferential stress. According to the above, the distribution function and curve of tangential stress can be obtained according to force balance differential equations on circumferential direction and Trasca rule. Subsequently the real state and virtual state moment equations were established, a new method was presented adopting the virtual principle of deformation system to calculate the x-axis and y-axis displacement of arbitrary point on cross-section. So the major and minor axes of deformed cross-section can be calculated according to the displacements of each point, and the variety value of major and minor axes will be obtained further. Finally the theoretical calculating result is compared with NC tube rotary-bending experiment results to verify the rationality of theoretical analysis, and the cross-section deformation rule of thin-walled tube can be received. 展开更多
关键词 thin-walled tube stress analysis major and minor axes cross-section deformation virtual force
下载PDF
Cross-sectional survey of the relationship of symptomatology, disability and family burden among patients with schizophrenia in Sichuan, China 被引量:6
19
作者 Zhuoqiu ZHANG Hong DENG Ying CHEN Shuiying LI Qian ZHOU Hua LAI Lifang LIU Ling LIU wenwu SHEN 《上海精神医学》 2014年第1期22-29,共8页
关键词 精神分裂症 财政负担 横断面调查 家庭 症状 患者 中国 四川
下载PDF
Analysis of the mass of behind-armor debris generated by RHA subjected to normal penetration of variable cross-section EFP 被引量:4
20
作者 Boyang Xing Dongjiang Zhang +7 位作者 Zhenyan Guo Yunhui Hou Rui Guo Rongzhong Liu Liang Chen Hao Zhou Yongliang Yang Jianhua Luo 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2019年第3期390-397,共8页
Analyzing the mass of behind-armor debris (BAD) generated by Rolled Homogeneous Armor (RHA) subjected to normal penetration of variable cross-section Explosively Formed Projectile (EFP) is the purpose of this paper. S... Analyzing the mass of behind-armor debris (BAD) generated by Rolled Homogeneous Armor (RHA) subjected to normal penetration of variable cross-section Explosively Formed Projectile (EFP) is the purpose of this paper. So theoretical analysis, numerical simulation and experimental data are combined to analyze the influence of variable cross-section characteristic on the time history of crater radius. Moreover the relationships between time history of crater radius (as well as mass of BAD) and the thickness of RHA (from 30mm to 70 mm) and the impact velocity of EFP (1650 m/s to 1860 m/s) are also investigated. The results indicate that: 1) being compared to the variable cross-section characteristic is ignored, the theoretical time history of crater radius is in better agreement with the simulation results when the variable cross-section characteristic is considered;2) being compared to the other three conditions of plug, the theoretical mass of BAD is in the best agreement with the simulation results when the shape of plug is frustum of a cone and the angle between generatrix and bottom is 45- and the axial length of mushroom is considered. 展开更多
关键词 Explosively formed PROJECTILE Behind-armor DEBRIS Variable cross-section characteristic Shape of plug Axial length of MUSHROOM Theoretical model
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部