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Inflammatory Bowel Disease and Dementia:Evidence Triangulation from a Meta-Analysis of Observational Studies and Mendelian Randomization Study
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作者 Di Liu Meiling Cao +9 位作者 Shanshan Wu Bingli Li Yiwen Jiang Tengfei Lin Fuxiao Li Weijie Cao Jinqiu Yuan Feng Sha Zhirong Yang Jinling Tang 《Biomedical and Environmental Sciences》 2025年第1期56-66,共11页
Objective Observational studies have found associations between inflammatory bowel disease(IBD)and the risk of dementia,including Alzheimer’s dementia(AD)and vascular dementia(VD);however,these findings are inconsist... Objective Observational studies have found associations between inflammatory bowel disease(IBD)and the risk of dementia,including Alzheimer’s dementia(AD)and vascular dementia(VD);however,these findings are inconsistent.It remains unclear whether these associations are causal.Methods We conducted a meta-analysis by systematically searching for observational studies on the association between IBD and dementia.Mendelian randomization(MR)analysis based on summary genome-wide association studies(GWASs)was performed.Genetic correlation and Bayesian colocalization analyses were used to provide robust genetic evidence.Results Ten observational studies involving 80,565,688 participants were included in this metaanalysis.IBD was significantly associated with dementia(risk ratio[RR]=1.36,95%CI=1.04-1.78;I2=84.8%)and VD(RR=2.60,95%CI=1.18-5.70;only one study),but not with AD(RR=2.00,95%CI=0.96-4.13;I^(2)=99.8%).MR analyses did not supported significant causal associations of IBD with dementia(dementia:odds ratio[OR]=1.01,95%CI=0.98-1.03;AD:OR=0.98,95%CI=0.95-1.01;VD:OR=1.02,95%CI=0.97-1.07).In addition,genetic correlation and co-localization analyses did not reveal any genetic associations between IBD and dementia.Conclusion Our study did not provide genetic evidence for a causal association between IBD and dementia risk.The increased risk of dementia observed in observational studies may be attributed to unobserved confounding factors or detection bias. 展开更多
关键词 DEMENTIA Inflammatory bowel disease META-ANALYSIS Observational studies Mendelian randomization Genetic evidence Evidence triangulation
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Research on the Training Model of“Foreign Languages+Area Studies”Interdisciplinary Talent Development:A Case Study of China’s Talent Training for International Ocean Affairs
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作者 GUO Rui 《Sino-US English Teaching》 2025年第1期22-27,共6页
This paper proposes an interdisciplinary talent training model that combines foreign language education with area studies.The model aims to cultivate international ocean affairs professionals with cross-cultural commu... This paper proposes an interdisciplinary talent training model that combines foreign language education with area studies.The model aims to cultivate international ocean affairs professionals with cross-cultural communication skills,in-depth regional and country knowledge,and practical expertise in ocean affairs.Additionally,the paper presents specific training pathways and policy recommendations for implementing this model. 展开更多
关键词 foreign languages area studies talent development for international ocean affairs educational reform
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Study on English Translations of“The Little Prince”from the Perspective of Descriptive Translation Studies
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作者 Xianting Yi 《Journal of Contemporary Educational Research》 2025年第9期358-365,共8页
In modern society,the globalization of literary works is evident,with exceptional literary pieces from various countries spreading worldwide.Among these,children’s literature,due to the specificity of its target audi... In modern society,the globalization of literary works is evident,with exceptional literary pieces from various countries spreading worldwide.Among these,children’s literature,due to the specificity of its target audience,imposes distinct requirements on children’s books,compelling translators to approach the text from a child’s perspective.“The Little Prince”has renowned both within and outside of China,and a careful reading of this work can provide us with much inspiration.To this end,the present study adopts the perspective of Gideon Toury’s Descriptive Translation Studies to conduct an in-depth analysis of the different English and Chinese translations in conjunction with the original French novel.This approach aims to better guide literary research and explores translation methods for children’s literature through the analysis of translation norms and rules. 展开更多
关键词 Gideon toury Descriptive translation studies “The Little Prince” Children’s literature
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Ethical awareness and issues in gastrointestinal endoscopy practice:A survey study
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作者 Yi Qin Ming-Yang Shi 《World Journal of Gastroenterology》 2026年第1期151-157,共7页
BACKGROUND Gastrointestinal endoscopy technology has significantly improved the diagnostic accuracy and the successful treatment of gastrointestinal diseases.However,a series of ethical issues have emerged,such as exp... BACKGROUND Gastrointestinal endoscopy technology has significantly improved the diagnostic accuracy and the successful treatment of gastrointestinal diseases.However,a series of ethical issues have emerged,such as expanding treatment indications,which affect the fair distribution of medical resources.There is limited research on ethical issues in the field of digestive endoscopy.AIM To investigate the level of ethical awareness among gastrointestinal endoscopy practitioners and analyze the ethical issues involved in gastrointestinal endoscopy technology.METHODS A questionnaire survey was performed to collect relevant data(gender,age,degree of education,professional title,personnel category,the level of understanding medical ethical principles,ethics training and its learning pathways)from gastrointestinal endoscopy practitioners at the Second Hospital of Dalian Medical University and Dalian Friendship Hospital,including licensed physicians and nurses(including trainees and graduate students).RESULTS The majority of gastrointestinal endoscopy practitioners have received training on ethics,but there is still considerable room for improvement in their ethical awareness.Different learning pathways may affect the mastery of ethical principles, and understanding of ethical principles is more easily achieved through hospital ethics institutions.CONCLUSIONTo address the ethical issues in gastrointestinal endoscopy technology, it is necessary to enhance the humanisticeducation of gastrointestinal endoscopy practitioners, incorporate ethical standards into the technology assessmentprocess, and establish a patient-centered diagnostic and treatment model to improve the ethical awareness of practitionersand achieve a balance between technology and ethics. 展开更多
关键词 Gastrointestinal endoscopy Ethical awareness Ethical issues Medical ethics Survey study
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Residential greenness,air pollution,and incident age-related macular degeneration:A prospective cohort study
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作者 Jiali Wang Yinyan Gao +2 位作者 Yijuan Lin Irene X.Y.Wu Fang Xiao 《Journal of Environmental Sciences》 2026年第1期242-249,共8页
Existing evidence suggests residential greenness is beneficial to human,while no research to date explored the associations of greenness with age-related macular degeneration(AMD).To evaluate the association of greenn... Existing evidence suggests residential greenness is beneficial to human,while no research to date explored the associations of greenness with age-related macular degeneration(AMD).To evaluate the association of greenness with AMD,modification and mediation effect of air pollution,we conducted this prospective study.We con-structed weighted quantile sum(WQS)index as co-exposure to nitrogen oxides(NO_(x)),particulate matter<2.5μm(PM_(2.5)),particulate matter<10μm(PM10).Stratified Cox regression models were applied to test the effect of exposure.Effect modification of air pollution was assessed.Stratified Cox models through the indirect method and Aalen additive risk models were used in mediation analysis.Over median follow-up of 11.67 years,4596 AMD events were ascertained.Hazard ratios(HRs)and 95%confidence intervals(95%CIs)of incident AMD for pollution per interquartile range(IQR)increment were 1.10(1.04–1.16)for nitrogen dioxide(NO_(2)),1.09(1.03–1.15)for NO_(x),1.14(1.05–1.24)for PM_(2.5),1.13(1.05–1.21)for PM10.The HR(95%CI)of AMD associated with greenness 1000 m buffer per IQR increment was 0.91(0.86–0.97),300 m buffer was 0.94(0.89–0.99).The as-sociation between greenness 1000 m and AMD was 28.59%,44.77%,35.59%,32.31%and 27.08%mediated by the decreased WQS index,NO_(2),NO_(x),PM_(2.5) and PM10,respectively.Increased greenness was associated with lower AMD incidence,and air pollution partly mediate it,which implies that interventions aimed at improving air quality and increasing greenness could have a dual benefit in mitigating AMD risk. 展开更多
关键词 Age-related macular degeneration(AMD) Residential greenness Ambient air pollution Mediation effect Prospective cohort study
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Profiling vaccine attitudes and subsequent uptake in 1·1 million people in England:a nationwide cohort study
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作者 Matthew Whitaker 《四川生理科学杂志》 2026年第1期216-216,共1页
Background:Despite highly effective vaccines against SARS-CoV-2,COVID-19 vaccine hesitancy persisted in some populations in England during the pandemic,with rates and motivations for hesitancy varying by demographic g... Background:Despite highly effective vaccines against SARS-CoV-2,COVID-19 vaccine hesitancy persisted in some populations in England during the pandemic,with rates and motivations for hesitancy varying by demographic group.Addressing the drivers of vaccine hesitancy through targeted interventions in hesitant groups is a public health priority for better and more rapid control of disease spread.We aimed to characterise the determinants and subtypes of vaccine hesitancy and identify more persistent forms of hesitancy via analysis of vaccine uptake in a large cross-sectional cohort with linked National Health Service(NHS)data. 展开更多
关键词 vaccine hesitancy demographic group targeted interventions vaccine uptake vaccine attitudes SARS CoV public health priority nationwide cohort study
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Early GLP-1 Agonist Use and Cancer Risk in Type 2 Diabetes:A Real-World Data Cohort Study
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作者 Cheng-Hsun Chuang Ping-Kun Tsai +2 位作者 Shih-Wen Kao Yu-Hsun Wang Chao-Bin Yeh 《Oncology Research》 2026年第1期237-253,共17页
Background:To determine whether initiating a glucagon-like peptide-1 receptor agonist(GLP-1 RA)within 3 months of type 2 diabetes(T2DM)diagnosis alters the subsequent risk of overall and site-specific cancer and wheth... Background:To determine whether initiating a glucagon-like peptide-1 receptor agonist(GLP-1 RA)within 3 months of type 2 diabetes(T2DM)diagnosis alters the subsequent risk of overall and site-specific cancer and whether this association differs by baseline body-mass index(BMI).Methods:This retrospective cohort study used electronic health records from the TriNetX U.S.research network.Adults aged 20 years or older diagnosed with T2DM between 2016 and 2024 were included if they received any hypoglycemic agents within 3 months before and after diagnosis.Following 1:1 propensity score matching,both the GLP-1 RA user and non-user groups included 183,264 patients.The study outcome was defined as a diagnosis of malignant neoplasms.Hazard ratios(HRs)for overall and site-specific cancer risk were estimated using Cox proportional hazards models.Kaplan–Meier analysis and stratified analysis by BMI were performed.Results:Early GLP-1 RA use demonstrated a modest but significant association with reduced overall cancer risk(HR 0.93;95%CI:0.90–0.96).Reduced risks were noted for cancers of the digestive(HR 0.81),respiratory(HR 0.66),and female genital(HR 0.87)systems.In stratified analysis,benefits were more pronounced in patients with BMI≥30,particularly for pancreatic and colorectal cancers.Conclusion:Early initiation of GLP-1 receptor agonists in patients with diagnosed T2DM was associated with a modest reduction in overall cancer risk,particularly among individuals with obesity.These findings highlight the dual metabolic and oncologic value of prompt GLP-1 RA therapy. 展开更多
关键词 Glucagon-like peptide-1(GLP-1)receptor agonists type 2 diabetes mellitus cancer risk OBESITY cohort study
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Comparative Studies on Tourist Satisfaction of World Heritage Sites——A Case Study of Huangshan Mountain,Lushan Mountain and Wuyi Mountain
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作者 顾晓艳 《Journal of Landscape Research》 2009年第4期85-90,共6页
Through the questionnaire survey and comparative studies on tourist satisfaction of tourism services among three world heritage sites,i.e.Huangshan Mountain,Lushan Mountain and Wuyi Mountain,this study pointed out the... Through the questionnaire survey and comparative studies on tourist satisfaction of tourism services among three world heritage sites,i.e.Huangshan Mountain,Lushan Mountain and Wuyi Mountain,this study pointed out the problems in tourism services of three scenic areas and then put forward relevant countermeasures for the management of scenic areas. 展开更多
关键词 World HERITAGE SITES TOURIST SATISFACTION COMPARATIVE study Huangshan MOUNTAIN Lushan MOUNTAIN Wuyi MOUNTAIN
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A comparison study of the start-up of a MnO_x filter for catalytic oxidative removal of ammonium from groundwater and surface water 被引量:6
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作者 Ya Cheng Ye Li +3 位作者 Tinglin Huang Yuankui Sun Xinxin Shi Yuezong Shao 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2018年第3期327-334,共8页
As an efficient method for ammonium(NH4~+)removal,contact catalytic oxidation technology has drawn much attention recently,due to its good low temperature resistance and short start-up period.Two identical filters ... As an efficient method for ammonium(NH4~+)removal,contact catalytic oxidation technology has drawn much attention recently,due to its good low temperature resistance and short start-up period.Two identical filters were employed to compare the process for ammonium removal during the start-up period for ammonium removal in groundwater(Filter-N)and surface water(Filter-S)treatment.Two types of source water(groundwater and surface water)were used as the feed waters for the filtration trials.Although the same initiating method was used,Filter-N exhibited much better ammonium removal performance than Filter-S.The differences in catalytic activity among these two filters were probed using X-ray diffraction(XRD),scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS),and compositional analysis.XRD results indicated that different manganese oxide species were formed in Filter-N and Filter-S.Furthermore,the Mn3p XPS spectra taken on the surface of the filter films revealed that the average manganese valence of the inactive manganese oxide film collected from Filter-S(FS-MnOx)was higher than in the film collected from Filter-N(FN-MnOx).Mn(IV)was identified as the predominant oxidation state in FS-MnOxand Mn(III)was identified as the predominant oxidation state in FN-MnOx.The results of compositional analyses suggested that polyaluminum ferric chloride(PAFC)used during the surface water treatment was an important factor in the mineralogy and reactivity of MnOx.This study provides the theoretical basis for promoting the wide application of the technology and has great practical significance. 展开更多
关键词 Ammonium removal Surface water Underground water start-up Catalytic oxidation FILTRATION
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Pressure-flow studies in patients with benign prostatic hyperplasia:a study comparing suprapubic and transurethral methods 被引量:2
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作者 Shan-Chao Zhao Shao-Bin Zheng Wan-Long Tan Peng Zhang Huan Qi 《Asian Journal of Andrology》 SCIE CAS CSCD 2006年第6期731-735,共5页
Aim: To compare the use of the suprapubic puncture method versus the transurethral method in pressure-flow studies in patients with benign prostatic hyperplasia. Methods: Twenty-three men with benign prostatic hyper... Aim: To compare the use of the suprapubic puncture method versus the transurethral method in pressure-flow studies in patients with benign prostatic hyperplasia. Methods: Twenty-three men with benign prostatic hyperplasia underwent both suprapubic and transurethral pressure-flow studies during a single session. Standard pressure-flow variables were recorded in all patients with both methods, enabling calculation of obstruction using commonly used grading systems, such as the urethral resistance algorithm, the Abrams-Griffith (AG) number and the Schaefer linear nomogram. Results: There were statistically significant differences between the methods in the mean values of maximum flow rate (P 〈 0.05), detrusor pressure at the maximum flow (P 〈 0.01), urethral resistance algorithm (P 〈 0.01), AG number (P 〈 0.01) and maximum cystic capacity (P 〈 0.01). Of the men in the study, 10 (43.5%) remained in the same Schaefer class with both methods and 18 (78.3%) in the same AG number area. Using the transurethral method, 12 (52.2%) men increased their Schaefer class by one and 1 (4.3%) by two. There were also differences between the suprapubic and transurethral methods using the AG number: 4 (17.4%) men moved from a classification of equivocal to obstructed and 1 (4.3%) from unobstructed to equivocal. Conclusion: The differences between the techniques for measuring intravesical pressure alter the grading of obstruction determined by several of the commonly used classifications. An 8 F transurethral catheter significantly increases the likelihood of a diagnosis of bladder outlet obstruction when compared with the suprapubic method. 展开更多
关键词 URODYNAMICS pressure-flow study SUPRAPUBIC TRANSURETHRAL benign prostatic hyperplasia bladder outlet obstruction
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Molecular Dynamics Study of Star Polymer Melts under Start-up Shear 被引量:1
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作者 Dong-Dong Wang Kai-Feng Yu +1 位作者 Xiao-Lei Xu Wen-Sheng Xu 《Chinese Journal of Polymer Science》 SCIE EI CAS CSCD 2022年第7期807-816,共10页
It has been established that star polymers with a large number of arms display both the conventional chain relaxation and a slower interchain relaxation due to the formation of hard cores,which is called the local str... It has been established that star polymers with a large number of arms display both the conventional chain relaxation and a slower interchain relaxation due to the formation of hard cores,which is called the local structural relaxation.Here,we demonstrate that this unique relaxation property of multi-arm stars leads to unusual rheological behaviors.We study the response of star polymer melts with various arm numbers to start-up shear flow via nonequilibrium molecular dynamics simulation.Our simulation results indicate that the stress-strain response of multi-arm star polymer melts differs from that of star polymers with a small number of arms in both quantitative and qualitative manners.While the multi-arm star polymer melts exhibit an overshoot peak in the stress-strain curve both at relatively small and sufficiently large shear rates,two overshoot peaks appear when the flow strength is comparable to the relaxation time of the star polymers.This double stress overshoot is absent in linear polymers and star polymers with a small number of arms and is evidently related to the presence of the local structural relaxation in star polymers with a large number of arms.We present a detailed analysis of the conformational and dynamical properties of star polymer melts under start-up shear to gain a molecular understanding of their stress response. 展开更多
关键词 SIMULATION Star polymer start-up shear
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Study on durability of Pt supported on graphitized carbon under simulated start-up/shut-down conditions for polymer electrolyte membrane fuel cells 被引量:2
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作者 Won Suk Jung 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2018年第1期326-334,共9页
The primary issue for the commercialization of proton exchange membrane fuel cell(PEMFC) is the carbon corrosion of support under start-up/shut-down conditions. In this study, we employ the nanostructured graphitize... The primary issue for the commercialization of proton exchange membrane fuel cell(PEMFC) is the carbon corrosion of support under start-up/shut-down conditions. In this study, we employ the nanostructured graphitized carbon induced by heat-treatment. The degree of graphitization starts to increase between 900 and 1300 ℃ as evidenced by the change of specific surface area, interlayer spacing, and ID/IG value. Pt nanoparticles are deposited on fresh carbon black(Pt/CB) and carbon heat-treated at 1700 ℃(Pt/HCB17) with similar particle size and distribution. Electrochemical characterization demonstrates that the Pt/HCB17 shows higher activity than the Pt/CB due to the inefficient microporous structure of amorphous carbon for the oxygen reduction reaction. An accelerating potential cycle between 1.0 and 1.5 V for the carbon corrosion is applied to examine durability at a single cell under the practical start-up/shutdown conditions. The Pt/HCB17 catalyst shows remarkable durability after 3000 potential cycles. The Pt/HCB17 catalyst exhibits a peak power density gain of 3%, while the Pt/CB catalyst shows 65% loss of the initial peak power density. As well, electrochemical surface area and mass activity of Pt/HCB17 catalyst are even more stable than those of the Pt/CB catalyst. Consequently, the high degree of graphitization is essential for the durability of fuel cells in practical start-up/shut-down conditions due to enhancing the strong interaction of Pt and π-bonds in graphitized carbon. 展开更多
关键词 Polymer electrolyte membrane fuel ceils Membrane electrolyte assembly Carbon corrosion start-up/shut-down Durability
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Coffee consumption and risk of type 2 diabetes mellitus in Asians:A meta-epidemiological study of population-based cohort studies 被引量:1
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作者 Jong-Myon Bae 《World Journal of Diabetes》 SCIE 2021年第6期908-915,共8页
BACKGROUND Previous systematic reviews have consistently reported that coffee consumption has a preventive effect on the occurrence of type 2 diabetes mellitus(T2DM).However,further evaluations between coffee consumpt... BACKGROUND Previous systematic reviews have consistently reported that coffee consumption has a preventive effect on the occurrence of type 2 diabetes mellitus(T2DM).However,further evaluations between coffee consumption and the risk of T2DM in Asian populations are needed.AIM To conduct a meta-epidemiological study on systematic reviews evaluating the association between coffee consumption and the risk of T2DM in Asian people.METHODS The selection criterion was defined as a population-based prospective cohort study evaluating the association between coffee consumption and the risk of T2DM in Asian populations,reporting the adjusted relative risk(RR)and its 95%confidence interval(CI)for potential confounders.A fixed-effect model metaanalysis was applied to calculate the summary RR and its 95%CI in less than 50%of the I2 value indicating the level of heterogeneity.A two-stage fixed-effects doseresponse meta-analysis(DRMA)was performed to calculate the risk per unit dose(a cup per day).RESULTS A total of seven studies were selected in this meta-epidemiological study.The risk of T2DM in Asian populations was significantly reduced in the highest to the lowest dose group(summary RR=0.73,95%CI:0.66-0.82;I2 value=0.0%).The DRMA showed that drinking one cup of coffee per day reduced the risk of T2DM in Asian populations by 8%(RR=0.92,95%CI:0.90-0.95).CONCLUSION These findings support the conclusion that coffee consumption has a protective effect on the occurrence of T2DM in Asian men and women. 展开更多
关键词 COFFEE Diabetes mellitus Cohort studies META-ANALYSIS Systematic reviews
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A Comparative Study of Of Studies and Wang Zuoliang's Translated Version
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作者 陈健飞 《海外英语》 2014年第21期139-140,152,共3页
Of Studies is an important one in The Essays of Francis Bacon, of which words are concise and refining, reasoning is profound and logic. Wang Zuoliang's translated version is so efficient and smooth with classical... Of Studies is an important one in The Essays of Francis Bacon, of which words are concise and refining, reasoning is profound and logic. Wang Zuoliang's translated version is so efficient and smooth with classical Chinese style that it perfectly reveals the original text, turning out to be the best version among all the translation of Of Studies. This thesis compares Of Studies and Wang Zuoliang's translated version to analyze their linguistic feature in terms of diction, sentence and figures of speech. 展开更多
关键词 Of Studies translated VERSION DICTION SENTENCE FIG
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Study design in evidence-based surgery:What is the role of case-control studies?
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作者 Amy M Cao Michael R Cox Guy D Eslick 《World Journal of Methodology》 2016年第1期101-104,共4页
Randomized controlled trials(RCTs) are the gold standard in terms of study design, however, in the surgical setting conducting RCTs can often be unethical or logistically impossible. Case-control studies should become... Randomized controlled trials(RCTs) are the gold standard in terms of study design, however, in the surgical setting conducting RCTs can often be unethical or logistically impossible. Case-control studies should become the major study design used in surgical research when RCTs are unable to be conducted and definitely replacing case series which offer little insight into surgical outcomes and disease processes. 展开更多
关键词 Research STUDIES CASE-CONTROL STUDIES RANDOMIZED CLINICAL trials BIAS SAMPLE size
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Numerical study of plasmas start-up by electron cyclotron waves in NCST spherical tokamak and CN-H1 stellarator
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作者 刘亿卓行 郑平卫 +4 位作者 龚学余 尹岚 陈小昌 钟翊君 杨文军 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第7期12-22,共11页
According to the physics of tokamak start-up,this study constructs a zero-dimensional(0D)model applicable to electron cyclotron(EC)wave assisted start-up in NCST spherical torus(spherical tokamak)and CN-H1 stellarator... According to the physics of tokamak start-up,this study constructs a zero-dimensional(0D)model applicable to electron cyclotron(EC)wave assisted start-up in NCST spherical torus(spherical tokamak)and CN-H1 stellarators.Using the constructed 0D model,the results obtained in this study under the same conditions are compared and validated against reference results for pure hydrogen plasma start-up in tokamak.The results are in good agreement,especially regarding electron temperature,ion temperature and plasma current.In the presence of finite Ohmic electric field in the spherical tokamak,a study on the EC wave assisted start-up of the NCST plasma at frequency of 28 GHz is conducted.The impact of the vertical magnetic field B_(v)on EC wave assisted start-up,the relationship between EC wave injection power P_(inj),Ohmic electric field E,and initial hydrogen atom density n_(H0)are explored separately.It is found that under conditions of Ohmic electric field lower than ITER(~0.3 V m^(-1)),EC wave can expand the operational space to achieve better plasma parameters.Simulating the process of28 GHz EC wave start-up in the CN-H1 stellarator plasma,the plasma current in the zerodimensional model is replaced with the current in the poloidal coil of the stellarator.Plasma startup can be successfully achieved at injection powers in the hundreds of kilowatts range,resulting in electron densities on the order of 10^(17)-10^(18)m^(-3). 展开更多
关键词 spherical torus STELLARATOR electron cyclotron wave start-up 0D model
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Numerical study on ignition start-up process of an underwater solid rocket motor across a wide depth range
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作者 Deyou WANG Shipeng LI +3 位作者 Ge JIN Ruyao WANG Dian GUAN Ningfei WANG 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2024年第10期136-157,共22页
Solid rocket motors have important applications in the propulsion of trans-media vehicles and underwater launched rockets.In this paper,the ignition start-up process of an underwater solid rocket motor across a wide d... Solid rocket motors have important applications in the propulsion of trans-media vehicles and underwater launched rockets.In this paper,the ignition start-up process of an underwater solid rocket motor across a wide depth range has been numerically studied.A novel multi-domain integrated model has been developed by combining the solid propellant ignition and combustion model with the volume of fluid multiphase model.This integrated model enables the coupled simulation of the propellant combustion and gas flow inside the motor,along with the gas jet evolution in the external water environment.The detailed flow field developments in the combustion chamber,nozzle,and wake field are carefully analyzed.The variation rules of the internal ballistics and thrust performance are also obtained.The effects of environmental medium and operating depth on the ignition start-up process are systematically discussed.The results show that the influence of the operating environment on the internal ballistic characteristics is primarily reflected in the initial period after the nozzle closure opens.The development of the gas jet in water lags significantly compared with that in air.As the water depth increases,the ignition delay time of the motor is shortened,and the morphology evolution of the gas jet is significantly compressed and accelerated.Furthermore,the necking and bulging of the jet boundary near the nozzle outlet and the consequent shock oscillations are intensified,resulting in stronger fluctuations in the wake pressure field and motor thrust. 展开更多
关键词 Underwater propulsion Solid rocket motor Ignition start-up process Underwater gas jet Thrust oscillation
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STUDIES ON DOPAMINE RECEPTORS AND TETRAHYDROPROTOBERBERINES.Ⅲ.3D-QSAR STUDY ON TETRAHYDROPROTOBERBERINES USING COMFA APPROACH
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作者 Yun TANG Kai Xian CHEN +2 位作者 Hua Liang JIANG Guo Zhang JIN Ru Yun JI(Shanghai Institute of Materia Medica. Chinese Academy of Sciences,294 Taiyuan Road, Shanghai 200031) 《Chinese Chemical Letters》 SCIE CAS CSCD 1996年第3期249-252,共4页
Using comparative molecular field analysis approach, the interaction of 17 tetrahydroprotdederines to D1 reccptor and15 ones to D2 reccptor have ben studied by 3D-QsAR. respectively. The results indicated that the int... Using comparative molecular field analysis approach, the interaction of 17 tetrahydroprotdederines to D1 reccptor and15 ones to D2 reccptor have ben studied by 3D-QsAR. respectively. The results indicated that the interactions of THPBs withdopamine receplors were primarily clectrostatic interactions. with more positive charge in lignnd and more negative in receptor. 展开更多
关键词 QSAR study APPROACH AND
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Geological Studies to Support the Tourism Site: A Case Study in the <i>Rafflesia</i>Trail, Near Kampung Jedip, Lojing Highlands, Kelantan, Malaysia
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作者 Dony Adriansyah Nazaruddin Nur Syazwani Md. Fadilah +2 位作者 Zurfarahin Zulkarnain Sharifah Aisyah Syed Omar Mohamad Khidzir Mohd Ibrahim 《International Journal of Geosciences》 2014年第8期835-851,共17页
Some geological studies were performed in the Rafflesia Trail, near Kampung Jedip, in Lojing Highlands, Kelantan. This area is famous for its Rafflesia and has become one of the tourism attractions in Kelantan. Howeve... Some geological studies were performed in the Rafflesia Trail, near Kampung Jedip, in Lojing Highlands, Kelantan. This area is famous for its Rafflesia and has become one of the tourism attractions in Kelantan. However, the recent development of agricultural activities has significant effects on the area. The objective of these studies is to give substantial geological information including geomorphology, lithology, structural features, geohazard potentials, and water quality analysis in the study area. Desk study was conducted by reviewing some literatures related to the topic and the study area. Field work was organized during a scientific expedition in January 2014, to collect data, samples, and photographs. Geomorphologically, the study area is a mountainous area which mostly consists of mountain ridges and mountain valleys. Some fluvial features occur in the study area, such as waterfalls, cascades, rapids, runs, pools, potholes, lateral bars, and point bars. This area is composed of granitic rocks, mostly granite porphyry, and covered by superficial deposits of Quaternary age. The geological structure that is commonly found in the study area is joints, where they divide the rock body into large, roughly angular blocks, which is called as brecciation. The potential geohazard in the study area is landslides, where some of them are composed of soil only and others are mixtures of rock and soil. The water quality analysis has managed to identify that the stream water in this area generally has the quality of Class III (according to INWQS for Malaysia). These studies recommend that this area should be supported as a sustainable tourism site in Lojing Highlands. 展开更多
关键词 GEOLOGICAL STUDIES Sustainable Tourism Site The Rafflesia TRAIL Lojing HIGHLANDS Kelantan
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