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   12501篇
  免费   1317篇
  国内免费   537篇
耳鼻咽喉   109篇
儿科学   238篇
妇产科学   225篇
基础医学   1393篇
口腔科学   299篇
临床医学   1382篇
内科学   1804篇
皮肤病学   366篇
神经病学   789篇
特种医学   582篇
外国民族医学   12篇
外科学   1557篇
综合类   1770篇
一般理论   1篇
预防医学   743篇
眼科学   334篇
药学   1192篇
  9篇
中国医学   591篇
肿瘤学   959篇
  2024年   12篇
  2023年   154篇
  2022年   241篇
  2021年   464篇
  2020年   453篇
  2019年   380篇
  2018年   396篇
  2017年   361篇
  2016年   374篇
  2015年   533篇
  2014年   639篇
  2013年   690篇
  2012年   1027篇
  2011年   944篇
  2010年   763篇
  2009年   588篇
  2008年   768篇
  2007年   810篇
  2006年   728篇
  2005年   590篇
  2004年   528篇
  2003年   535篇
  2002年   474篇
  2001年   365篇
  2000年   282篇
  1999年   230篇
  1998年   109篇
  1997年   108篇
  1996年   84篇
  1995年   62篇
  1994年   63篇
  1993年   51篇
  1992年   83篇
  1991年   57篇
  1990年   62篇
  1989年   45篇
  1988年   35篇
  1987年   22篇
  1986年   29篇
  1985年   31篇
  1984年   19篇
  1982年   16篇
  1981年   10篇
  1979年   10篇
  1978年   9篇
  1977年   9篇
  1975年   12篇
  1974年   15篇
  1972年   9篇
  1968年   10篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Recent epidemiological studies suggested that proton pump inhibitor (PPI) use was associated with an increased risk of biliary tract cancer (BTC), however, confounders were not adequately controlled. Our study aimed to evaluate PPI use and subsequent risk of BTC and its subtypes in three well-established cohorts. We conducted a pooled analysis of the subjects free of cancers in UK Biobank (n = 463 643), Nurses' Health Study (NHS, n = 80 235) and NHS II (n = 95 869). Propensity score weighted Cox models were used to estimate marginal HRs of PPIs use on BTC risk, accounting for potential confounders. We documented 284 BTC cases in UK Biobank (median follow-up: 7.6 years), and 91 cases in NHS and NHS II cohorts (median follow-up: 15.8 years). In UK biobank, PPI users had a 96% higher risk of BTC compared to nonusers in crude model (HR 1.96, 95% CI 1.44-2.66), but the effect was attenuated to null after adjusting for potential confounders (HR 0.95, 95% CI 0.60-1.49). PPI use was not associated with risk of BTC in the pooled analysis of three cohorts (HR 0.93, 95% CI 0.60-1.43). We also observed no associations between PPI use with risk of intrahepatic (HR 1.00, 95% CI 0.49-2.04), extrahepatic bile duct (HR 1.09, 95% CI 0.52-2.27) and gallbladder cancers (HR 0.66, 95% CI 0.26-1.66) in UK Biobank. In summary, regular use of PPIs was not associated with the risk of BTC and its subtypes.  相似文献   
2.
3.
患者于2000年无明显诱因发现下腹部游走性包块,20年来多次就诊,未明确病因。2020年8月11日发现包块游走于左侧腋前,微创手术取出不完整白色虫体3段,用宏基因组学测序鉴定虫体,明确诊断为曼氏裂头蚴病。2021年10月21日经手术取出完整虫体,患者康复出院;随访患者身体状况良好,全身未发现新包块。  相似文献   
4.
Hepatitis E virus (HEV) is the most common cause of acute liver failure (LF) and one of the most common factors causing acute injury in acute-on-chronic LF (ACLF). When HEV-related LF occurs, a series of changes take place in both the intrahepatic environment and extrahepatic microenvironment. The changed types and distribution of immune cells (infiltrating macrophages and increased lymphocytes) in liver tissue, as well the increased proinflammatory cytokines and chemokines in the blood, indicate that the occurrence and progression of HEV-related LF are closely related to immune imbalance. The clinical features and immune reaction in the body during HEV-related acute LF (ALF) and ACLF are complicated. This review highlights recent progress in elucidating the clinical manifestations of HEV-associated ALF and ACLF and discusses the corresponding systemic immune changes and possible regulatory mechanisms.  相似文献   
5.
We aim to assess the safety and efficacy of proxalutamide, a novel androgen receptor antagonist, for men with metastatic castration-resistant prostate cancer (mCRPC) in a multicenter, randomized, open-label, phase 2 trial. In our study, the enrolled mCRPC patients were randomized to 100, 200 and 300 mg dose groups at 1:1:1. The primary efficacy endpoint was prostate-specific antigen (PSA) response rate. The secondary endpoints included objective response rate (ORR), disease control rate (DCR) and time to PSA and radiographic progression. Safety and pharmacokinetics were also assessed. Finally, there were 108 patients from 17 centers being enrolled. By week 16, there were 13 (35.1%), 12 (36.4%) and 15 (42.9%) patients with confirmed 50% or greater PSA decline in 100 mg (n = 37), 200 mg (n = 33) and 300 mg (n = 35) groups, respectively. Among the 19 patients with target lesions at study entry, three (15.8%) had a partial response and 12 (63.2%) had stable disease. The ORRs of 20.0%, 22.2%, 0% and DCRs of 80.0%, 88.9%, 60.0% were, respectively, achieved in 100, 200 and 300 mg groups. By the maximum follow-up time of 24 weeks, there were 42.6% and 10.2% of cases experiencing PSA progression and radiographic progression, respectively. Overall, adverse events (AEs) were experienced by 94.4% of patients, most of which were mild or moderate. There were 28 patients experiencing ≥grade 3 AEs. The most common AEs were fatigue (17.6%), anemia (14.8%), elevated AST (14.8%) and ALT (13.0%), decreased appetite (13.0%). These findings preliminarily showed the promising antitumor activity of proxalutamide in patients with mCRPC with a manageable safety profile. The proxalutamide dose of 200 mg daily is recommended for future phase 3 trial (Clinical trial registration no. CTR20170177).  相似文献   
6.
7.
8.

Objecive

To clarify the neuroimaging findings of children with acute flaccid myelitis during an outbreak of EV-D68 infection.

Methods

We performed a detailed review of the spinal and cranial MRI results of 54 children with acute flaccid myelitis. We focused on the range of longitudinal lesions, the localization and appearance of lesions within a horizontal section, Gadolinium-enhancement, and changes over time.

Results

All children had longitudinal spinal lesions involving central gray matter. Twenty-six children had lesions spanning the entire spine. Six of them had weakness in all limbs, whereas seven had weakness of only one limb. Thirty-eight children had lesions in both gray and white matter and limb weakness tended to be more severe in these children. During the acute period, spinal lesions showed bilateral ill-defined widespread T2 hyperintensity. During the subacute period, lesions were well defined and confined to the anterior horn. The distribution of limb weakness was correlated with the appearance of lesions during the subacute period. Gadolinium enhancement was performed in 37 children, and enhancement was seen in the cauda equina in 29 children. Enhancement was infrequent within 2?days after onset but was seen in almost all children thereafter. Twenty-two children had brainstem lesions continuous with spinal lesions.

Conclusion

Extensive longitudinal spinal lesions were characteristic in children with acute flaccid myelitis. Lesions were usually bilateral and widespread during the acute period, whereas localization to the anterior horn could become obvious. Although enhancement of the cauda equina was often observed, its appearance was sometimes delayed.  相似文献   
9.
10.
The term ‘lupus erythematosus’ refers to a range of related disorders, and types of lupus affecting the skin are collectively known as cutaneous lupus erythematosus (CLE). CLE can cause several different types of rashes. Many of these are often seen in areas of the body that are exposed to the sun. CLE patients can suffer from fatigue, pain, scarring, hair loss, and even sensitivity to the sun, all of which have been shown to negatively affect quality of life (QoL). Because of how subjective most of these symptoms are, it is important to use appropriate measures that can adequately examine the QoL in patients. Therefore, this study, from the U.S.A., aimed to demonstrate the ‘reliability’ and ‘validity’ of the cutaneous lupus erythematosus quality of life (CLEQoL) measure, which is a tool that allows patients to describe how CLE affects their QoL. Reliability means that if you take the same test multiple times, you should get roughly the same results every time, while validity broadly means that the test measures what it's supposed to. The CLEQoL was found to have sufficient reliability and validity in assessing the QoL in patients with CLE. Our findings show that CLEQoL is a practical and useful tool in examining QoL in CLE patients and could be considered for use in future drug development and clinical trials, as well as in clinical practice for routine monitoring of patients’ well-being.  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