全文获取类型
收费全文 | 5252篇 |
免费 | 679篇 |
国内免费 | 361篇 |
专业分类
耳鼻咽喉 | 71篇 |
儿科学 | 38篇 |
妇产科学 | 49篇 |
基础医学 | 564篇 |
口腔科学 | 52篇 |
临床医学 | 838篇 |
内科学 | 751篇 |
皮肤病学 | 85篇 |
神经病学 | 256篇 |
特种医学 | 202篇 |
外科学 | 533篇 |
综合类 | 802篇 |
现状与发展 | 3篇 |
一般理论 | 1篇 |
预防医学 | 415篇 |
眼科学 | 151篇 |
药学 | 607篇 |
6篇 | |
中国医学 | 351篇 |
肿瘤学 | 517篇 |
出版年
2024年 | 33篇 |
2023年 | 144篇 |
2022年 | 340篇 |
2021年 | 402篇 |
2020年 | 300篇 |
2019年 | 266篇 |
2018年 | 221篇 |
2017年 | 211篇 |
2016年 | 207篇 |
2015年 | 297篇 |
2014年 | 368篇 |
2013年 | 260篇 |
2012年 | 405篇 |
2011年 | 397篇 |
2010年 | 243篇 |
2009年 | 182篇 |
2008年 | 294篇 |
2007年 | 250篇 |
2006年 | 201篇 |
2005年 | 212篇 |
2004年 | 115篇 |
2003年 | 106篇 |
2002年 | 115篇 |
2001年 | 87篇 |
2000年 | 88篇 |
1999年 | 115篇 |
1998年 | 91篇 |
1997年 | 71篇 |
1996年 | 52篇 |
1995年 | 44篇 |
1994年 | 41篇 |
1993年 | 19篇 |
1992年 | 28篇 |
1991年 | 16篇 |
1990年 | 19篇 |
1989年 | 9篇 |
1988年 | 10篇 |
1987年 | 10篇 |
1986年 | 7篇 |
1985年 | 6篇 |
1984年 | 1篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 2篇 |
排序方式: 共有6292条查询结果,搜索用时 15 毫秒
101.
102.
A homogenization-based five-step multi-scale finite element (FsMsFE) simulation framework is developed to describe the time-temperature-dependent viscoelastic behavior of 3D braided four-directional composites. The current analysis was performed via three-scale finite element models, the fiber/matrix (microscopic) representative unit cell (RUC) model, the yarn/matrix (mesoscopic) representative unit cell model, and the macroscopic solid model with homogeneous property. Coupling the time-temperature equivalence principle, multi-phase finite element approach, Laplace transformation and Prony series fitting technology, the character of the stress relaxation behaviors at three scales subject to variation in temperature is investigated, and the equivalent time-dependent thermal expansion coefficients (TTEC), the equivalent time-dependent thermal relaxation modulus (TTRM) under micro-scale and meso-scale were predicted. Furthermore, the impacts of temperature, structural parameters and relaxation time on the time-dependent thermo-viscoelastic properties of 3D braided four-directional composites were studied. 相似文献
103.
Gongwei Zhai Ang Li Binfeng Liu Dongbo Lv Jingyi Zhang Weichao Sheng Guang Yang YanZheng Gao 《Medicine》2021,100(16)
To identify the risk factors of the secondary fractures for osteoporotic vertebral compression fractures (OVCFs) after percutaneous vertebroplasty (PVP).We conducted a search of relevant articles using Cochrane Library, PubMed, Medline, Science Direct, Embase, the Web of Science and other databases. The time range we retrieved from establishment of the electronic database to November 2017. Gray studies were found in the references of included literature reports. STATA version 11.0 (Stata Corporation, College Station, Texas) was used to analyze the pooled data.Fourteen studies involving 1910 patients, 395 of whom had fracture secondary to the surgery were included in this meta-analysis. The result of meta-analyses showed the risk factors of the secondary fractures for OVCFs after PVP was related to bone mineral density (BMD) [95%CI (−0.650, −0.164), SMD=−0.407, P=.001], cement leakage ((RR=0.596, 95%CI (0.444,0.798), P = .001)), and kyphosis after primary operation ((SMD=0.741, 95%CI (0.449,1.032), P = .000)), but not to gender, age, body mass index, cement volume, thoracolumbar spine, and cement injection approaches.Bone mineral density, cement leakage, and kyphosis after primary operation are the risk factors closely correlative to the secondary fracture after PVP. There have not been enough evidences to support the association between the secondary fracture and gender, age, body mass index, cement volume, thoracolumbar spine, and cement injection approaches. 相似文献
104.
Introduction:Subchromosomal deletions and duplications could currently be detected by noninvasive preliminary screening (NIPS). However, NIPS is a screening test that requires further diagnosis. Here we report a fetus with an autosomal abnormality revealed by NIPS and conventional karyotype combined with copy number variations sequencing (CNV-seq) confirmed the fetus with an unbalanced translocation.Patient concern:This was the fourth pregnancy of a 30-year-old woman who underwent 2 spontaneous abortions and gave birth to a child with a normal phenotype. The woman and her husband were healthy and nonconsanguineous. NIPS indicated a repeat of about 19-Mb fragment at the region of 16q22.1-q22.4 at 17-week gestation.Diagnoses:The combination of traditional karyotype and CNV-seq could better locate the abnormal chromosomal region and further identify the source of fetal chromosomal abnormalities. Simultaneously, we evaluated the fetal morphology by ultrasound examination. The karyotype of the fetus was 46,XX,der(7)t(7;16)(p22;q23) and CNV-seq results showed an approximately 20.96-Mb duplication in 16q22.1-q24.3 (69200001-90160000) and an approximately 3.86-Mb deletion in 7p22.3-p22.2 (40001-3900000). Prenatal ultrasound revealed the fetal micrognathia. The paternal karyotype was 46,XY, t (7;16) (p22;q23), while the maternal was normal. The fetus inherited an abnormal chromosome 7 from its father.Interventions:No treatment for the fetus.Outcomes:Pregnancy was terminated.Conclusions:To our knowledge, the occurrence of de novo partial trisomy 16q (16q22.1-qter) and partial monosomy 7p (7p22.2-pter) has not previously been reported up to now. Here, we present the perinatal findings of such a case and a review of the literatures. CNV-seq combined with karyotype is a useful tool for chromosomal abnormalities indicated by NIPS. 相似文献
105.
某高校临床医学“+”专业医学统计学试卷分析 《医学教育管理》2019,5(6):552-556
目的 通过分析某高校临床医学“5+3”专业学生《医学统计学》考试试卷,了解学生学习情况,改善试卷质量,为进一步教学改革提供依据。方法 采用教育测量学的原理与方法对试卷的难度、区分度、信度(Cronbach α 系数)和覆盖度及考试成绩进行分析。结果 147 名八年制临床医学学生《医学统计学》试卷的平均成绩为78.25±11.70 分,最低分为42.5 分,最高分为98.5 分,及格率为91.2%;选择题平均得分率85%,名词解释题平均得分率87.2%,填空题平均得分率78%,简答题平均得分率74.1%,计算题平均得分率76.3%;试卷难度系数为0.22,区分度为0.28,;试卷的Cronbach α 系数为0.846,题目间的相关系数< 0.2的占89%。结论 本次考试学生成绩优良;试卷难度稍显偏低,总体区分度一般,信度良好,试题覆盖面较广,试卷整体质量优良,能够反映学生掌握知识的水平,今后的教学中应开展多元统计相关知识及统计软件的操作,提高学生的科研素质。 相似文献
106.
107.
研究围绝经期女性骨质疏松症的相关因素,为及时进行干预防治提供方向。
采用多级分层随机抽样方法,对上海市浦东新区高桥社区内围绝经期女性进行问卷调查、骨密度测量和重要激素水平的检测。
共收集有效问卷720份。在接受调查的720名围绝经期女性中,骨质疏松173人,非骨质疏松547人。单因素分析显示,不同围绝经期女性骨质疏松患者甲状旁腺素(PTH)水平、雌二醇(E2)水平、体重指数(BMI)、年龄、末次月经时间、绝经等差异有统计学意义
绝经、PTH水平的异常升高是影响女性骨质疏松患病的危险因素;围绝经期女性应加强骨密度监测,对骨量减少和骨质疏松者及时采取相应的干预和必要的治疗措施。
108.
Caiyi Lu Shiwen Wang Yuxiao Zhang Qiao Xue Cangsong Xiao Wei Gao Jinwen Tian Lei Gao Shenhua Zhou Jinyue Zhai Rui Chen Zhongren Zhao Cangqing Gao Ming Yang Yang Wu Gang Wang Qi Zhou 《老年心脏病学杂志》2008,5(3):186-189
A 69-year old female patient was admitted because of 3 days of worsened chest pain.Coronary angiography showed 60% stenosis of distal left main stem,chronic total occlusion of left anterior descending (LAD),70% stenosis at the ostium of a small left circumflex,70-90% stenosis at the paroxysmal and middle part of a dominant right coronary artery (RCA),and a normal left internal mammary artery (LIMA) with normal origination and orientation.Percutaneous intervention was attempted but failed on the occluded lesion of LAD.The patient received minimally invasive direct coronary artery bypass (MIDCAB) with left LIMA isolation by Davinci robot.Eleven days later,the RCA lesion was treated by Sirolimus Rapamicin eluting stents implantation percutaneously.Then the patient was discharged uneventfully after 3 days hospitalization.Our experience suggests that two stop shops of hybrid technique be feasible and safe in the treatment of elderly patient with multiple coronary diseases. 相似文献
109.
精神分裂症患者的家庭负担研究 总被引:19,自引:0,他引:19
目的评价精神分裂症患者的家庭负担和家庭功能。方法采用家庭负担量表(FBS)和家庭关怀度指数问卷(APGAR),对350例符合DSM-Ⅳ诊断标准的精神分裂症患者的家庭负担进行评定,从家庭的角度评价精神分裂症的疾病负担。结果精神分裂症患者FBS的家庭经济负担、家庭日常活动、家庭休闲娱乐活动、家庭成员心理健康4个因子的阳性回答率较高(均高于60%),家庭成员生理健康、家庭关系两个因子的阳性回答率较低(均低于40%);农村患者的家庭经济负担因子评分显著高于城镇患者(P<0.01),而家庭成员心理健康因子评分显著低于城镇患者(P<0.05)。结论精神分裂症造成严重的家庭负担,应作为干预的对象。 相似文献
110.
Long Xiaoqing Zhai Yaling Wang Yingzi Dou Yanna Cheng Genyang Xiao Jing Zhao Zhanzheng Wen Xuejun. 《中华肾脏病杂志》2018,34(12):887-892
Objective To sum up and analyze the clinical and pathological characteristics in patients with both IgA nephropathy (IgAN) and diabetes mellitus. Methods A total of 500 patients were recruited, including 25 patients with both IgAN and diabetes mellitus, and 475 patients with IgAN only, who were diagnosed by renal-biopsy during Jan 2015 to Jan 2017 at the First Affiliated Hospital of Zhengzhou University. The clinical and pathological data were collected and analyzed using SPSS 22.0. Propensity Score Matching was used to match and select the patients in the both groups, and thereafter the depth of the basement membrane from the matched patients were compared using electron microscopy. The data of the patients whose follow-up time was ≥3 months were retrospectively collected, and Kaplan-Meier analysis was used to compare the difference of the prognosis. Results Compared to the patients with IgAN only, patients with both IgAN and diabetes mellitus were older [(46.36±13.49) years vs (34.00±13.80) years, P<0.001], had higher level of serum triglyceride [2.06(1.52, 3.11) mmol/L vs 1.51(1.01, 2.25) mmol/L, P=0.012] and thicker basement membrane [(384.33±61.20) nm vs (346.72±52.65) nm, P=0.044]. The patients with both IgAN and diabetes mellitus were more prone to reach the composite endpoint [4/7(57.14%) vs 25/265(9.33%), P<0.001] and had worse prognosis (Log-Rank test, P=0.004). Conclusions IgAN patients with diabetes mellitus have different clinical, pathological characteristics and prognosis from patients with IgAN alone. These patients need to be closely monitored and actively treated. 相似文献