首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   19837篇
  免费   1094篇
  国内免费   350篇
耳鼻咽喉   142篇
儿科学   430篇
妇产科学   107篇
基础医学   1507篇
口腔科学   129篇
临床医学   1788篇
内科学   1199篇
皮肤病学   59篇
神经病学   240篇
特种医学   976篇
外科学   7766篇
综合类   2494篇
预防医学   1211篇
眼科学   20篇
药学   1728篇
  11篇
中国医学   946篇
肿瘤学   528篇
  2024年   24篇
  2023年   360篇
  2022年   773篇
  2021年   934篇
  2020年   836篇
  2019年   827篇
  2018年   773篇
  2017年   651篇
  2016年   732篇
  2015年   745篇
  2014年   1520篇
  2013年   1218篇
  2012年   1275篇
  2011年   1362篇
  2010年   1059篇
  2009年   1101篇
  2008年   1016篇
  2007年   999篇
  2006年   793篇
  2005年   760篇
  2004年   573篇
  2003年   429篇
  2002年   349篇
  2001年   311篇
  2000年   274篇
  1999年   202篇
  1998年   172篇
  1997年   144篇
  1996年   111篇
  1995年   106篇
  1994年   85篇
  1993年   78篇
  1992年   74篇
  1991年   72篇
  1990年   50篇
  1989年   43篇
  1988年   54篇
  1987年   51篇
  1986年   30篇
  1985年   40篇
  1984年   37篇
  1983年   48篇
  1982年   31篇
  1981年   34篇
  1980年   28篇
  1979年   26篇
  1978年   14篇
  1977年   19篇
  1975年   8篇
  1973年   9篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
BackgroundIncreased hip adduction and internal rotation can lead to excessive patellofemoral joint stress and contribute to patellofemoral pain development. The gluteus maximus acts as a hip extensor, abductor, and external rotator. Improving hip extensor use by increasing one’s forward trunk lean in the sagittal plane may improve frontal and transverse plane hip kinematics during stair ascent.Research questionDoes increasing forward trunk lean during stair ascent affect peak hip adduction and internal rotation?MethodsTwenty asymptomatic females performed five stair ascent trials (96 steps/min) on an instrumented stair using their self-selected and forward trunk lean postures. Three-dimensional kinematics (200 Hz) and kinetics (2000 Hz) were recorded during the stance phase of stair ascent. Biomechanical dependent variables were calculated during the stance phase of stair ascent and included peak forward trunk lean, hip flexion, hip adduction, hip internal rotation angles, and the average hip extensor moment.ResultsDuring the forward trunk lean condition, decreases were observed for peak hip adduction (MD = 2.8˚; 95% CI = 1.9, 3.8; p < 0.001) and peak hip internal rotation (MD = 1.1˚; 95% CI = 0.1, 2.2; p = 0.04). In contrast, increases were observed during the forward trunk lean condition for the peak forward trunk lean angle (MD = −34.7˚; 95% CI = −39.1, −30.3; p < 0.001), average hip extensor moment (MD = −0.5 N·m/kg; 95% CI = −0.5, −0.4; p < 0.001), and stance time duration (MD = −0.02 s; 95% CI = −0.04, 0.00; p = 0.017).SignificanceIncreasing forward trunk lean and hip extensor use during stair ascent decreased peak hip adduction and internal rotation in asymptomatic females. Future studies should examine the effects of increasing forward trunk lean on hip kinematics, self-reported pain, and function in individuals with patellofemoral pain.  相似文献   
3.
4.
5.
6.
BackgroundPost-operative elderly hip fracture patients require significant rehabilitation. Nandrolone is an anabolic steroid used to promote muscle growth. This study aims to examine the effect of nandrolone in improving rehabilitation and quality of life in elderly female patients with hip fractures undergoing hemiarthroplasty.MethodsThis is a double-blinded prospective randomized-controlled-trial consisting of female patients above the age of 65 with an isolated neck of femur fracture planned for a hip hemiarthroplasty. Participants were randomized into two arms of the study – 50 mg intramuscular nandrolone vs normal saline placebo administered on post-operative day 0, and weeks 2, 6 and 12. The participants were followed up across a 1-year period following the surgery. Clinical outcomes such as time taken to achieve rehabilitation milestones, distance of ambulation and thigh muscle girth, and functional scoring with SF-36 questionnaire were recorded at intervals of 2, 6 and 12 weeks, 6 months and 1 year following the surgery.ResultsThere were a total of 23 subjects with 11 in the steroid group and 12 in the placebo group. There was no significant difference in demographics and injury patterns between both groups. There was no significant difference for time taken to achieve various rehabilitation milestones and distance of ambulation. SF-36 scores on discharge and at 1-year follow-up mark were comparable. There was no difference in the complication rate between both groups.ConclusionIntra-muscular Nandrolone after hip surgery in elderly female patients does not result in short to mid-term improved rehabilitation or functional outcomes. Nandrolone did not result in increased short-term complications after hip surgery.Level of evidenceI.  相似文献   
7.
BACKGROUND Surgery for gastric cancer is a complex procedure and lymphadenectomy is often mandatory.Postoperative mortality and morbidity after curative gastric cancer surgery is not insignificant.AIM To evaluate the factors determining mortality and morbidity in a population of patients undergoing R0 resection and D2 lymphadenectomy for gastric cancer.METHODS A retrospective analysis of clinical data and pathological characteristics(age,sex,primary site of the tumor,Lauren histotype,number of positive lymph nodes resected,number of negative lymph nodes resected,and depth of invasion as defined by the standard nomenclature)was conducted in patients with gastric cancer.For each patient we calculated the Kattan’s score.We arbitrarily divided the study population of patients into two groups based on the nomogram score(<100 points or≥100 points).Prespecified subgroups in these analyses were defined according to age(≤65 years or>65 years),and number of lymph nodes retrieved(≤35 lymph nodes or>35 lymph nodes).Uni-and multivariate analysis of clinical and pathological findings were performed to identify the factors affecting postoperative mortality and morbidity.RESULTS One-hundred and eighty-six patients underwent a curative R0 resection with D2 lymphadenectomy.Perioperative mortality rate was 3.8%(7 patients);a higher mortality rate was observed in patients aged>65 years(P=0.002)and in N+patients(P=0.04).Following univariate analysis,mortality was related to a Kattan’s score≥100 points(P=0.04)and the presence of advanced gastric cancer(P=0.03).Morbidity rate was 21.0%(40 patients).Surgical complications were observed in 17 patients(9.1%).A higher incidence of morbidity was observed in patients where more than 35 lymph nodes were harvested(P=0.0005).CONCLUSION Mortality and morbidity rate are higher in N+and advanced gastric cancer patients.The removal of more than 35 lymph nodes does not lead to an increase in mortality.  相似文献   
8.
9.
《Pancreatology》2022,22(8):1175-1180
BackgroundHepatic steatosis has been described as a common finding in adults following total pancreatectomy with islet autotransplantation (TPIAT) but it is unknown if this occurs in children and adolescents.ObjectivesTo define the frequency of post-TPIAT hepatic steatosis in a sample of children and adolescents and to identify clinical predictors of incident steatosis post-TPIAT.MethodsIn this prospective study, consecutive participants at least 1-month post-TPIAT underwent a liver MRI with proton density fat fraction (PDFF) and blood draw at our pediatric academic medical center between April 2021 and January 2022. Comparison clinical pre-TPIAT liver MRI or ultrasound and insulin use and graft function data were extracted from the medical record. T-tests were used for the comparison of means across continuous variables between participants with and without post-TPIAT steatosis.ResultsA total of 20 participants (mean: 13 ± 4 years; 12 female) were evaluated. Mean liver PDFF at research MRI was 7.4 ± 6.2% (range: 2–25%). Seven participants (35%) had categorical hepatic steatosis (PDFF>5%) post-TPIAT, five of whom had pre-TPIAT steatosis, reflecting a 13% (2/15; 95% CI: 2–40%) incidence of post-TPIAT steatosis. Participant characteristics were not significantly different between subgroups with and without post-TPIAT steatosis. Mean PDFF at research MRI was not different between graft function subgroups (7.5% optimal/good vs. 7.3% marginal/failure; p = .96).ConclusionOur study shows a moderate prevalence but low incidence of hepatic steatosis in a small sample of children and adolescents post-TPIAT. This study raises questions about a causal relationship between TPIAT and hepatic steatosis.  相似文献   
10.
BackgroundPeriprosthetic tibial fractures in Total Knee Arthroplasty are much less commonly seen than femoral fractures, and there is a paucity of available literature and management recommendation for these fractures. We aimed to identify the relevant and up-to-date literature on this subject to analyse the incidence, risk factors, and management recommendations.MethodsA literature search was done on the databases of PubMed and SCOPUS using appropriate keywords. All the published literature in the English language was included for this review.ResultsWe included 21 studies comprising 260 tibial periprosthetic fractures (91 intra-operative (35%) and 169 (65%) post-operative or delayed fractures). Only 5.9% of these fractures were managed conservatively. Whereas 98 cases (58%) were managed with open reduction and internal fixation (ORIF) with plating, 19 (11.2%) were managed with revision TKA. Seventeen cases (10%) were managed with minimally invasive percutaneous plate osteosynthesis (MIPPO), and 8 (4.7%) were managed with intramedullary nailing. Less than 6% of cases were managed with other means, viz. megaprosthesis (n = 4), arthrodesis (n = 5), amputation (n = 1), and external fixator (n = 1).ConclusionIntraoperative fractures accounted for one-third of the fractures in our review. A majority of the delayed periprosthetic fractures were treated with surgical intervention. The most preferred surgical treatment method was ORIF of fractures using locking plates (either open or MIPPO). Revision TKA or megaprosthesis was used in cases with the loosened implants in association with the fracture.Level of evidenceIV  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号