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   215088篇
  免费   5202篇
  国内免费   3036篇
耳鼻咽喉   1695篇
儿科学   7046篇
妇产科学   3317篇
基础医学   20419篇
口腔科学   2148篇
临床医学   17607篇
内科学   35516篇
皮肤病学   1246篇
神经病学   18221篇
特种医学   10442篇
外国民族医学   16篇
外科学   32661篇
综合类   11336篇
现状与发展   17篇
一般理论   2篇
预防医学   21186篇
眼科学   3625篇
药学   13954篇
  57篇
中国医学   3596篇
肿瘤学   19219篇
  2024年   154篇
  2023年   635篇
  2022年   1634篇
  2021年   2357篇
  2020年   1919篇
  2019年   1411篇
  2018年   23328篇
  2017年   18764篇
  2016年   20741篇
  2015年   2987篇
  2014年   3405篇
  2013年   3336篇
  2012年   10424篇
  2011年   24729篇
  2010年   21493篇
  2009年   13745篇
  2008年   21886篇
  2007年   23912篇
  2006年   2618篇
  2005年   3978篇
  2004年   4539篇
  2003年   5442篇
  2002年   3323篇
  2001年   1035篇
  2000年   1030篇
  1999年   693篇
  1998年   501篇
  1997年   514篇
  1996年   342篇
  1995年   317篇
  1994年   264篇
  1993年   151篇
  1992年   162篇
  1991年   196篇
  1990年   219篇
  1989年   174篇
  1988年   117篇
  1987年   98篇
  1986年   86篇
  1985年   70篇
  1984年   51篇
  1983年   30篇
  1982年   31篇
  1980年   40篇
  1938年   60篇
  1937年   25篇
  1935年   22篇
  1934年   30篇
  1932年   56篇
  1930年   46篇
排序方式: 共有10000条查询结果,搜索用时 218 毫秒
11.
Advancing nanomedicines from concept to clinic requires integration of new science with traditional pharmaceutical development. The medical and commercial success of nanomedicines is greatly facilitated when those charged with developing nanomedicines are cognizant of the unique opportunities and technical challenges that these products present. These individuals must also be knowledgeable about the processes of clinical and product development, including regulatory considerations, to maximize the odds for successful product registration. This article outlines these topics with a goal to accelerate the combination of academic innovation with collaborative industrial scientists who understand pharmaceutical development and regulatory approval requirements—only together can they realize the full potential of nanomedicines for patients.  相似文献   
12.
13.
While peer support has been investigated in multiple clinical contexts, its application to the postpartum setting is unknown. The aim was to assess acceptability of a postpartum peer support program for women with diabetes. Observational survey-based needs assessment of forty low-income women with diabetes, receiving care at a major medical institution. Mean age and gravidity were 30.7 years and 3.15 ± 1.67 respectively. 45 % expressed interest in a “buddy.” There was no significant difference between groups desiring and not desiring this program. A majority of respondents desired telephone, text messaging, and in-person contacts (79.2, 72.1, 83.8 %), with 72.5 % of patients desiring diabetes-related activities during clinic waiting time. Many women desire a postpartum diabetes reciprocal peer program for support outside of clinician visits. Patients are receptive to educational services during their wait and outside of clinic time, a potentially valuable opportunity to share important health information.  相似文献   
14.
By means of the ultrasonic surface impact (amplitude of 30 μm, strike number of 48,000 times/mm2), nanograins have been achieved in the surfaces of both Ti6Al4V(TC4) and Ti3Zr2Sn3Mo25Nb(TLM) titanium alloys, mainly because of the dislocation motion. Many mechanical properties are improved, such as hardness, residual stress, and roughness. The rotating–bending fatigue limits of TC4 and TLM subjected to ultrasonic impact are improved by 13.1% and 23.7%, separately. Because of the bending fatigue behavior, which is sensitive to the surface condition, cracks usually initiate from the surface defects under high stress amplitude. By means of an ultrasonic impact tip with the size of 8 mm, most of the inner cracks present at the zone with a depth range of 100~250 μm in the high life region. The inner crack core to TC4 usually appears as a deformed long and narrow α-phase, while the cracks in TLM specimens prefer to initiate at the triple grain boundary junctions. This zone crosses the grain refined layer and the deformed coarse grain layer. With the gradient change of elastic parameters, the model shows an increase of normal stress at this zone. Combined with the loss of plasticity and toughness, it is easy to understand these fatigue behaviors.  相似文献   
15.
16.
Stellate ganglion (SG) modification has been investigated for arrhythmia treatment. In this study, transesophageal SG imaging and intervention were explored using a homemade 30F integrated focused ultrasonic catheter in healthy mongrel canines in vivo. Anatomic details of SGs were ultrasonically imaged and evaluated. SG had a heterogeneous echoic structure and characteristic profiles sketched by hyper-echoic outlines in an ultrasonogram. Left SGs in the experimental group were successfully ablated through the esophagus under ultrasonic guidance provided by the catheter itself. Two weeks after the ablation, the QT and QTc of the experimental group decreased compared with those of the sham group and at baseline (both p values < 0.001). Histologic examination revealed that left SGs were destroyed. No major complications were observed. This approach may be further explored as a method for ganglia remodeling evaluation and as a strategy of ganglia modification for arrhythmia and for other diseases.  相似文献   
17.
目的研究晚期肺癌化疗患者发生医院感染的病原学特点,分析其危险因素,降低晚期肺癌化疗患者医院感染率。方法选择2012年1月-2015年12月收治的532例晚期肺癌化疗患者为研究对象,采集患者痰液或呼吸道分泌物标本进行细菌培养,应用SAS 9.3软件进行统计分析,并分析晚期肺癌化疗患者发生医院感染的危险因素。结果 125例晚期肺癌化疗患者发生医院感染,感染率为23.50%,其主要感染部位为呼吸道、胃肠道、口腔黏膜,分别占52.00%、15.20%、14.40%;共分离病原菌104株,其中革兰阴性菌51株占49.04%、革兰阳性菌30株占28.85%、真菌23株占22.11%;logistics回归显示,住院时间长、接受侵入性操作、使用抗菌药物是晚期肺癌化疗患者发生医院感染的危险因素。结论晚期肺癌化疗患者医院感染率较高,主要病原菌以革兰阴性菌为主,通过缩短患者住院时间、减少侵入性操作、合理使用抗菌药物等措施,降低晚期肺癌化疗患者医院感染的发生。  相似文献   
18.
19.
Objective To observe the clinical characteristics and prognosis of patients with rapidly progressive glomerulonephritis (RPGN) caused by lupus nephritis, antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis, or primary glomerulonephritis who were treated with peritoneal dialysis (PD) and then withdrew PD because of renal recovery. Methods Data of the above patients were retrospectively analyzed. The patients were diagnosed as RPGN and received PD therapy in Kidney Disease Center, the First Affiliated Hospital, College of Medicine, Zhejiang University from February 2009 to August 2018. The patients were divided into early withdrawal group (PD time≤183 days, n=24) and late withdrawal group (PD time>183 day, n=24). The differences of clinical characteristics between the two groups were compared. The cumulative incidence of adverse events in both groups was analyzed using Kaplan-Meier curves. Cox proportional hazards model was used to analyze the risk factors influencing the prognosis of patients. Results Forty-eight RPGN patients were included. The median time of maintaining PD was 178(76, 378) days. Compared with the late withdrawal group, the patients in early withdrawal group had lower levels of urine volume, serum albumin and parathyroid hormone, and lower rates of gross hematuria and hypertension at the beginning of PD, and received higher rates of methylprednisolone impulse, combined immunosuppressive agents, and hemodialysis or continuous renal replacement therapy (all P<0.05). At the time of PD withdrawal, the levels of serum creatinine, serum calcium, serum albumin and parathyroid hormone in the early withdrawal group were significantly lower than those in the late withdrawal group (all P<0.05). The Kaplan-Meier curves showed that there was no significant difference in the cumulative survival of patients in both groups (log-rank test χ2=3.485, P=0.062). Cox regression analysis revealed serum creatinine≥209 μmol/L at the time of PD withdrawal was an independent risk factor for poor prognosis (HR=5.253,95%CI 1.757-15.702, P=0.003). Conclusions PD can be used for RPGN patients caused by lupus nephritis, ANCA-associated vasculitis and primary nephritis. Serum creatinine≥209 μmol/L at the time of PD withdrawal is an independent risk factor for poor prognosis.  相似文献   
20.
高校医学生会利用假期时间对将要学习的科目进行预习,力求提前了解或掌握,以利于日后对知识的充分理解。预习对于医学科目学习有一定必要性,然而传统的假期预习模式常存在缺乏引导、效率难以提升等问题。目前,慕课在医学教育领域的应用有所发展。对于医学生,其自主学习的模式、课程设计等契合医学课程的预习需求和假期学习的特点,有助于提升医学生的学习能力和假期预习效果。医学生将慕课作为假期预习资源可有多种学习模式选择。慕课平台的功能拓展和学校教师的辅助可以有效深入慕课在医学生假期预习中的应用,为医学生带来更合理的假期学习安排。  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