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   14727篇
  免费   1582篇
  国内免费   274篇
耳鼻咽喉   51篇
儿科学   142篇
妇产科学   1756篇
基础医学   897篇
口腔科学   239篇
临床医学   1380篇
内科学   944篇
皮肤病学   164篇
神经病学   448篇
特种医学   574篇
外国民族医学   1篇
外科学   804篇
综合类   2559篇
预防医学   3422篇
眼科学   162篇
药学   1510篇
  11篇
中国医学   459篇
肿瘤学   1060篇
  2024年   23篇
  2023年   197篇
  2022年   415篇
  2021年   593篇
  2020年   535篇
  2019年   448篇
  2018年   500篇
  2017年   537篇
  2016年   636篇
  2015年   594篇
  2014年   1122篇
  2013年   1129篇
  2012年   1028篇
  2011年   1117篇
  2010年   826篇
  2009年   772篇
  2008年   712篇
  2007年   709篇
  2006年   646篇
  2005年   547篇
  2004年   526篇
  2003年   380篇
  2002年   335篇
  2001年   290篇
  2000年   239篇
  1999年   210篇
  1998年   172篇
  1997年   146篇
  1996年   112篇
  1995年   115篇
  1994年   112篇
  1993年   102篇
  1992年   124篇
  1991年   98篇
  1990年   89篇
  1989年   73篇
  1988年   72篇
  1987年   38篇
  1986年   38篇
  1985年   50篇
  1984年   30篇
  1983年   26篇
  1982年   29篇
  1981年   14篇
  1980年   24篇
  1979年   16篇
  1978年   9篇
  1977年   10篇
  1976年   6篇
  1974年   3篇
排序方式: 共有10000条查询结果,搜索用时 250 毫秒
11.
Caudal regression syndrome (CRS) is a rare congenital malformation with varying degrees of early gestational developmental failure. It is characterized by agenesis of the sacrum and lumbar spine, with lower limb neurological deficit and accompanying deformities of the pelvis, lower extremities, genitourinary, and gastrointestinal systems. We report a case of CRS associated with rare complex congenital heart defect, that is, heterotaxy syndrome, diagnosed prenatally.  相似文献   
12.
董微  张博  邵超 《西部医学》2019,31(5):679-682+688
【摘要】目的 探讨鲜天南星水提取物对小鼠子宫纤维瘤的抑制作用及对小鼠雌激素水平的影响。方法 选取SD健康雌性小鼠30只,随机分为正常组、模型组、实验组3组,每组各10只,对模型组、实验组进行子宫纤维瘤模型建立,正常组不作处理。实验组小鼠予以鲜天南星水提取物进行干预,正常组、模型组小鼠注射等体积生理盐水。对小鼠子宫重及子宫系数进行统计计算,酶联免疫吸附试验法检测雌二醇(Estradiol,E2)、孕酮(Progesterone,P)、卵泡刺激素(Follicle stimulating hormone,FSH)、黄体生成激素(Luteinizing Hormone,LH)水平。结果 干预后,模型组及实验组小鼠子宫重及子宫系数均高于正常组,实验组小鼠子宫重及子宫系数均低于模型组(P<0.05);干预后,模型组及实验组小鼠血清E2、P、FSH、LH水平均高于正常组,但实验组小鼠血清E2、P、FSH、LH水平均低于模型组(P<0.05)。结论 鲜天南星水提取物可对小鼠子宫纤维瘤起到一定的抑制作用,并能对E2、P、FSH、LH等激素水平进行调控,为子宫纤维瘤的临床治疗提供一定的理论依据,值得临床借鉴。  相似文献   
13.
Evaluation of the ossification of the medial clavicular epiphysis plays a key role in forensic age estimation. The purpose of the present study was to assess a new numerical cut-off at the age of 18 years, taking into consideration Magnetic Resonance (MR) images of the medial clavicular epiphysis. We analyzed 163 MR scans of Italian subjects aged between 14 and 25 years. Using the data obtained we calculated two ratios: REM-1 (ratio between the length of the whole epiphysis and the length of the metaphysis) and REM-2 (ratio between the length of epiphyseal-metaphyseal fusion and the length of the metaphysis). In 68 out of 163 cases it was not possible to measure REM-2. The reproducibility was demonstrated using the Intraclass Correlation Coefficient (ICC) (Cronbach’s alpha > 0.80). REM-1 and REM-2 were compared in each category of age (adult and minor) by the Wilcoxon signed-rank test. The cut-off points for measurements of REM-1 and REM-2 were determined by logistic regression. For REM-1, the cut-off scores were 0.83 for all individuals (accuracy = 94.77%) and males (accuracy = 96.05%), and 0.86 for females (accuracy = 92.30%). For REM-2, the cut-off values were 0.40 for all individuals and males (accuracy = 100.00%), and 0.41 for females (accuracy = 100.00%). Finally, receiver operating characteristic (ROC) curves for age classification based on REM-1 and REM-2 were constructed, showing that REM-2 had the highest discriminative power. Thus, a new cut-off model for predicting the age of majority has been introduced, conducting a quantitative analysis thanks to the use of a high-resolution imaging tool.  相似文献   
14.
目的:探讨孕期亲密伴侣暴力(IPV)与小于胎龄儿(SGA)的关联,并分析孕晚期就寝-晨起规律在其关联中的作用。方法:从2015年3月-2019年6月在合肥市三家医院的产科门诊招募孕妇4908名,使用WHO多国妇女健康和家庭暴力研究小组总结而来的清单式问卷进行调查,并采用多元logistic回归模型进行分析。结果:孕期精神暴力、躯体暴力、性暴力和总IPV发生率分别为9.1%、1.4%、0.9%和9.7%,SGA发生率为7.1%。回归分析结果显示,孕期IPV与SGA正向关联(OR=1.59);分别按就寝时间和晨起时间分层,7∶00后起床、22∶00-23∶00和23∶00后就寝组的IPV与SGA正向关联(OR=2.85、2.18、1.98);按就寝-晨起规律分层,非早睡早起组的IPV和IPV组的非早睡早起与SGA正向关联(OR=2.15、3.32)。结论:孕期遭受IPV(尤其是精神暴力)会增加SGA的风险,而就寝-晨起规律会使IPV与SGA的关联在不同的规律下增强或减弱。  相似文献   
15.
BackgroundMalnutrition measured by the geriatric nutritional risk index (GNRI) was reported to be associated with poor prognosis for patients with peripheral artery disease (PAD). However, the optimal cut-off value of preprocedural GNRI for critical limb ischemia (CLI) and intermittent claudication (IC) is unknown. We aimed to determine its optimal cut-off value for CLI or IC patients requiring endovascular revascularization.MethodsWe explored data of 2246 patients (CLI: n = 1061, IC: n = 1185) registered in the Tokyo-taMA peripheral vascular intervention research COmraDE (TOMA-CODE) registry, which prospectively enrolled consecutive PAD patients who underwent endovascular revascularization in 34 hospitals in Japan from August 2014 to August 2016. The optimal cut-off values of GNRI were assessed by the survival classification and regression tree (CART) analyses, and the survival curve analyses for major adverse cardiovascular and limb events (MACLEs) were performed for these cut-off values.ResultsIn addition to the first cut-off value of 96.2 in CLI and 85.6 in IC, the survival CART provided an additional cut-off value of 78.2 in CLI and 106.0 in IC for further risk stratification. The survival curve was significantly stratified by the GNRI-based malnutrition status in both CLI [high risk: 47.7% (51/107), moderate: 30.1% (118/392), and low: 10.2% (53/520), log–rank p < 0.001] and IC [high risk: 14.3% (7/49), moderate: 4.5% (29/646), and low: 0.5% (2/407), log–rank p < 0.001]. The multivariate Cox-proportional hazard analysis showed that a higher GNRI was significantly associated with a better outcome in both CLI [hazard ratio (HR) per 1-point increase: 0.97, 95% CI: 0.96–0.98, p < 0.001] and IC (HR: 0.94, 95% CI: 0.91–0.97, p < 0.001).ConclusionsPreprocedural nutritional status significantly stratified future events in patients with PAD. Given that the optimal cut-off value of GNRI in CLI was almost 10-points lower than that of IC, using a disease-specific cut-off value is important for risk stratification.  相似文献   
16.
目的探讨2型糖尿病患者病耻感现状,并分析病耻感的影响因素。方法2018年8月—2020年3月期间,采用便利抽样法,对该院就诊的135例2型糖尿病患者进行问卷调查。调查工具为一般情况调查表、2型糖尿病病耻感评估表。对病耻感的影响因素进行单因素分析和多因素分析。结果所有患者平均病耻感得分为(54.22±10.65)分。不同年龄、文化水平、是否接受胰岛素治疗、是否合并并发症等4个因素的单因素亚组分析显示,组间病耻感得分差异有统计学意义(P<0.05);采用逐步多元线性回归分析显示,只有年龄、是否合并并发症、文化水平是影响病耻感的独立因素。结论该次调查显示2型糖尿病患者普遍存在病耻感,年龄低、具有糖尿病并发症和文化水平较高的患者具有更明显的病耻感,应引起医务人员的重视,并及时给予治疗干预。  相似文献   
17.
Estimating stature based on body/limb parts can help define the characteristics of unidentified bodies. The most studied upper limb part is the hand, although few studies have examined whether stature can be estimated using fingers plus other hand dimensions. Moreover, there is paucity in anthropometric studies that determined whether bilateral whole limb parts (e.g., arms, forearms, and hands) are related to stature among the living subjects.This prospective cross-sectional study aimed to evaluate the relationship between different upper limb measurements and the stature of Saudi men. Furthermore, I assessed whether upper limb asymmetry was present, and developed regression models to estimate stature based on different available measurements. Stature and 13 upper limb parameters were measured for 100 right-handed Saudi men who were 18 to 24 years old.All measurements were positively correlated with stature (P < .001), and the best single predictor was the bilateral ulnar length. Asymmetry was more pronounced in the hand measurements. A multiparameter model provided reasonable predictive accuracy (±3.77–5.68 cm) and was more accurate than single-parameter models. Inclusion of the right-side fingers improved the model''s accuracy.This study developed potential models for estimating stature during the identification of bodies of Saudi men.  相似文献   
18.
ObjectiveDiagnosis of gastric intestinal metaplasia (GIM) relies on gastroscopy and histopathologic biopsy, but their application in screening for GIM is limited. We aimed to identify serological biomarkers of GIM via screening in Guangdong, China.MethodsCross-sectional field and questionnaire data, demographic information, past medical history, and other relevant data were collected. Blood samples were collected for pepsinogen (PG)I, PGII, gastrin-17, and Helicobacter pylori antibody testing, and gastroscopy and histopathologic biopsy were performed. Single factor and logistic regression analyses were used to evaluate the correlation between these indicators and GIM, and decision tree models were used to determine the cut-off points between indicators.ResultsOf 443 participants enrolled, 87 (19.6%) were diagnosed with GIM. Single factor analysis showed that pepsin indicators (PGI, PGII, and PGI/PGII ratio) and the factors Mandarin as native language, urban residency, hyperlipidemia, and age were associated with GIM. Logistic regression analysis showed that PGI and age were associated with GIM.ConclusionsAge is an important factor for predicting GIM progression; age >60 years increased its risk. Detection of GIM was higher in individuals with PGI levels >127.20 ng/mL, which could be used as a threshold indicating the need to perform gastroscopy and histopathologic biopsy.  相似文献   
19.
目的 探讨超声引导下经皮经肝胆囊穿刺置管引流术(Percutaneous Transhepatic Gallbladder Drainage,PTGD)术后发生继发性脓肿(Secondary abscess,SA)的发生率及其危险因素。方法 回顾性分析南京医科大学附属无锡人民医院2010年1月至2017年12月间410例经超声引导下PTGD患者的临床资料,采用单因素和多因素Logistic回归分析相关危险因素。结果 12例(2.93%,12/410)患者PTGD术后出现SA,再次针对SA穿刺引流的成功率100%。对良性疾病梗阻、基础疾病、胆囊大小、腹水、凝血功能、血小板、糖化血红蛋白(HbA1C)、短期内引流管脱落/自行拔出等混杂因素进行校正后,Logistic回归分析表明短期内引流管脱落/自行拔出(OR=6.64,95%Cl:3.34~13.81,P=0.03)和HbA1C>9.0%(OR=3.38,95%Cl:1.22~7.95,P=0.04)是引起术后SA的独立危险因素。结论 SA是超声引导下PTGD术后罕见的并发症,再次穿刺引流是治疗SA有效和安全的方法。临床可通过加强对穿刺引流管的保护和应用降血糖药物,降低PTGD术后SA的发生。  相似文献   
20.
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