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   28911篇
  免费   2292篇
  国内免费   252篇
耳鼻咽喉   357篇
儿科学   722篇
妇产科学   5002篇
基础医学   1426篇
口腔科学   350篇
临床医学   2949篇
内科学   3763篇
皮肤病学   342篇
神经病学   1193篇
特种医学   344篇
外科学   4917篇
综合类   2523篇
现状与发展   1篇
一般理论   4篇
预防医学   4137篇
眼科学   138篇
药学   1893篇
  17篇
中国医学   266篇
肿瘤学   1111篇
  2024年   56篇
  2023年   829篇
  2022年   1174篇
  2021年   1851篇
  2020年   1691篇
  2019年   1711篇
  2018年   1653篇
  2017年   1502篇
  2016年   1393篇
  2015年   1221篇
  2014年   2232篇
  2013年   2456篇
  2012年   1473篇
  2011年   1634篇
  2010年   1186篇
  2009年   1366篇
  2008年   1176篇
  2007年   1089篇
  2006年   988篇
  2005年   792篇
  2004年   690篇
  2003年   521篇
  2002年   414篇
  2001年   350篇
  2000年   336篇
  1999年   240篇
  1998年   225篇
  1997年   188篇
  1996年   137篇
  1995年   128篇
  1994年   108篇
  1993年   80篇
  1992年   58篇
  1991年   56篇
  1990年   44篇
  1989年   40篇
  1988年   38篇
  1987年   32篇
  1986年   18篇
  1985年   50篇
  1984年   36篇
  1983年   25篇
  1982年   31篇
  1981年   20篇
  1980年   19篇
  1979年   16篇
  1978年   21篇
  1977年   14篇
  1975年   13篇
  1973年   8篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
The peri-implantation period of pregnancy is critical for conceptus development, implantation, and signaling for establishment of pregnancy. This study evaluated the effects of bisphenol A (BPA) on proliferation, adhesion, and migration of porcine trophectoderm (pTr2) cells, expression of transporters of arginine and synthesis of amino acids. All concentrations of BPA decreased proliferation and adhesion of pTr2 cells after 96 h compared to the control group. Lower concentrations of BPA (1 × 10−9, 1 × 10-8, 10-7M) increased (P < 0.05), but higher concentrations of BPA (1 × 10-5, 1 × 10-4 M) decreased migration of pTr2 cells. BPA increased expression of SLC7A1 mRNA at lower concentrations (1 × 10−9 to 1 × 10-6M) and SL7A6, another cationic acid transporter, at higher concentrations (1 × 10-5, 1 × 10-4 M). BPA also down-regulated the expression of IGF1 and IGF1 receptor at concentrations of 1 × 10-7 to 1 × 10-4 M compared to the control group. The expression of mRNAs for aquaporins (AQP) 3 and 4 were reduced at all concentrations of BPA, but at lower concentrations of BPA, (1 × 10−9 to 1 × 10-8M) expression of AQP9 mRNA increased and the expression of AQP11 was not affected by BPA (P > 0.05). There was an inhibitory effect of BPA on the release of synthesis of asparagine, threonine, taurine, tryptophan, and ornithine into the culture medium by pTr2 cells. Collectively, BPA adversely affected the expression of transporters for cationic amino acids like arginine, as well as AQPs, IGF1, and IGF1R associated with proliferation, migration, and adhesion of pTr2 cells. Those adverse effects would likely increase pregnancy losses during the peri-implantation period of pregnancy.  相似文献   
42.
43.
《Enfermería clínica》2020,30(6):411-418
ObjectiveTo describe perceptions and wishes regarding childbirth in a group of full-term pregnant women in Zamora.MethodQualitative study of phenomenological character. Participants and scope of study: pregnant women (37-38 weeks), Zamora Sur and Santa Elena health centres (Zamora, Spain). Data collection: semi-structured interviews, until data saturation (16 interviews). Data analysis: analysis of thematic content.ResultsThe maternal feelings varied from joy to fear or stress. The interviewees said they did not feel capable of enduring the pain of childbirth. The needs that they felt most important were having support and accompaniment during delivery (especially of their partner) and receiving good treatment from the healthcare workers.ConclusionsThe importance and repercussion of childbirth for women are not only biological, but also largely mental, emotional and social. It is conditioned by multiple factors: maternal feelings, their ability to deal with the pain of childbirth, their needs, the changes they have made, the support they have and the health professionals who care for them.  相似文献   
44.
目的:探讨妊娠早期血清学指标糖化血红蛋白(glycohemoglobin,HbA1c)联合妊娠相关血浆蛋白A(pregnancy-associated plasma protein A,PAPP-A)对妊娠期糖尿病(gestational diabetes mellitus,GDM)的预测意义。方法:随机选取2018年12月1日-2019年7月30日孕11~13+6周于我院门诊产检的妊娠妇女,进行临床资料采集并记录妊娠早期(11~13+6周)空腹血糖(fasting plasma glucose,FPG)、HbA1c、PAPP-A中位数倍数(multiple of the median,MoM)水平,根据孕24~28周进行的75 g口服葡萄糖耐量试验(oral glucose tolerance test,OGTT)结果将研究对象分为研究组和对照组,统计分析妊娠早期血清学指标预测GDM的最佳截断值并得出最适宜的联合预测方案。结果:多因素Logistic回归分析显示,高水平FPG和HbA1c、低水平PAPP-A、受孕方式采用辅助生殖技术、有家族糖尿病史以及妊娠早期体质量指数(BMI)为超重或肥胖均是GDM发生的独立危险因素。有糖尿病家族史和使用辅助生殖技术受孕发生GDM的风险显著增高(OR分别为7.206和47.512,均P<0.001)。分析不同预测指标的受试者工作特征(receiver operating characteristic,ROC)曲线及曲线下面积(area under the curve,AUC)显示,PAPP-A MoM联合HbA1c及FPG诊断时AUC最大(0.728),其后依次为PAPPA MoM联合HbA1c(0.721)、HbA1c联合FPG(0.717),均大于HbA1c(0.707)和FPG(0.647),而PAPP-A MoM的AUC为0.380,对GDM没有诊断意义。结论:具有高风险因素的孕妇,推荐在妊娠早期联合检测HbA1c与PAPPA MoM,以早期预测GDM。  相似文献   
45.
46.
Background: Little is known of stroke outcomes in low- and middle-income countries with limited formal stroke rehabilitation services and of homebased-stroke services delivered within the primary health care (PHC) context by community health workers (CHWs).

Objectives: To describe and analyze the outcomes of patients with stroke from a rural PHC setting in the Western Cape, South Africa.

Methods: In a longitudinal survey, 93 stroke patients, referred to home and community-based care services (HCBC) between June 2015 and December 2017, were assessed at baseline, one month and three months. Changes in function (Barthel Index (BI)), caregiver strain (Caregiver Strain Index (CSI)), impact of environmental factors and satisfaction with stroke care were measured.

Results: HCBC was delayed, fragmented and brief (median session duration 20 minutes (IQR 15.0–30.0)). Although function improved significantly, dependence remained high: median BI score changed from 40.0 (IQR 15.0–70.0) to 62.5 (IQR 30.0–81.25) (p = .019). A third (33.0% (30/91)) of caregivers initially experienced strain and the median CSI score remained 3.0 (IQR 0.0–7.0) (p = .672). Overall, patient and caregiver satisfaction with HCBC was low with only 46.9% (31/66) of caregivers and 17.4% (12/69) of patients satisfied with all aspects of care. Only 47.6% of assistive product needs were met. Environmental factors negatively impacted on patient function and caregiving.

Conclusions: Clinical practice pathways and referral guidelines should be developed for the HCBC platform. Specific training of CHWs, focusing on how to educate, support and train family caregivers, provide assistive devices and refer to health services is needed.  相似文献   

47.
48.
49.
50.
《The Journal of arthroplasty》2022,37(9):1793-1798
BackgroundDespite numerous advances in the implant design and surgical technique, improvement in patient satisfaction following total knee arthroplasty (TKA) has plateaued. Various TKA alignment strategies have been introduced that impact the coronal positioning of the tibial component relative to the native joint line. This study aims to analyze if postoperative variance of the joint line from preoperative native alignment is correlated with changes in patient-reported outcomes following primary TKA.MethodsA retrospective review of an academic center’s patient population identified all primary TKAs between 2013 and 2021 with full-length, standing radiographs and patient-reported outcome measures (PROMs) data. These measures included the Knee injury and Osteoarthritis Outcome Score for Joint Replacement, Patient-Reported Outcome Measurement Information System, and Veterans RAND 12 scores. Preoperative and postoperative radiographic measurements for hip-knee angle, tibia-metaphyseal angle, tibial-axis orientation angle, and joint-line obliquity angle were recorded. Three-month, 1-year, and 2-year PROM scores were correlated with the change in degrees for each of the angles using a Spearman’s correlation. A Mann-Whitney U-test was used to compare angular changes with a change in PROM scores.ResultsOne hundred and ninety nine patients (204 knees) with a mean age of 67 years were included. Average follow-up was 23 months. Three-month, 1-year, and 2-year follow-up rates were 93%, 64%, and 34%, respectively. Improvements were seen across all PROMs regardless of an angular change.ConclusionThere were no clear correlations between PROMs and variation in joint line obliquity in the coronal plane. These data suggest that the magnitude of the variation in coronal tibial alignment from native alignment does not impact PROMs. Further study is indicated to correlate an angular change with functional measures.  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