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   11300篇
  免费   496篇
  国内免费   62篇
耳鼻咽喉   71篇
儿科学   416篇
妇产科学   166篇
基础医学   1521篇
口腔科学   227篇
临床医学   983篇
内科学   2582篇
皮肤病学   150篇
神经病学   1251篇
特种医学   345篇
外科学   1174篇
综合类   73篇
一般理论   10篇
预防医学   761篇
眼科学   88篇
药学   1033篇
中国医学   22篇
肿瘤学   985篇
  2024年   45篇
  2023年   113篇
  2022年   168篇
  2021年   295篇
  2020年   194篇
  2019年   259篇
  2018年   260篇
  2017年   200篇
  2016年   230篇
  2015年   264篇
  2014年   330篇
  2013年   470篇
  2012年   663篇
  2011年   713篇
  2010年   390篇
  2009年   359篇
  2008年   632篇
  2007年   662篇
  2006年   606篇
  2005年   644篇
  2004年   602篇
  2003年   561篇
  2002年   560篇
  2001年   216篇
  2000年   226篇
  1999年   191篇
  1998年   132篇
  1997年   120篇
  1996年   107篇
  1995年   76篇
  1994年   63篇
  1993年   54篇
  1992年   129篇
  1991年   114篇
  1990年   89篇
  1989年   102篇
  1988年   84篇
  1987年   89篇
  1986年   82篇
  1985年   100篇
  1984年   67篇
  1983年   56篇
  1982年   41篇
  1981年   33篇
  1979年   50篇
  1977年   36篇
  1975年   37篇
  1972年   36篇
  1970年   35篇
  1969年   35篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Objective::Pancreatic cancer (PC) is an aggressive cancer with ineffective treatment. Inhibition of stearoyl-CoA desaturase 1 (SCD1) suppresses cancer prolifera...  相似文献   
62.
Journal of Neuro-Oncology - Magmas (mitochondria-associated protein involved in granulocyte–macrophage colony-stimulating factor signal transduction) is a nuclear gene that encodes the...  相似文献   
63.
64.
65.
Summary Petroleum benzine is one of the mixtures of organic solvents containing n-hexane. The occurrence of polyneuropathy in the workers using petroleum benzines is attributed mainly to n-hexane, though other hydrocarbons present are also suspected of having some neurotoxicity or some potential which could modify the neurotoxicity of n-hexane. The present experiment was performed in order to clarify the toxicity of petroleum benzine to the peripheral nerve and compare it with that of n-hexane.Forty rats were randomly divided into five groups. The groups were exposed to 200 ppm n-hexane, 500 ppm n-hexane, and petroleum benzine vapor containing 200 ppm n-hexane or 500 ppm n-hexane, together with aliphatic and aromatic hydrocarbons for 12 h a day for 24 weeks. The body weight, motor nerve conduction velocity, motor distal latency, and mixed nerve conduction velocities were measured before exposure and every 4 weeks of exposure. A rat from each exposed group was histopathologically examined after 24 weeks' exposure.The function of the peripheral nerve was conspicuously impaired by 500 ppm n-hexane, slightly impaired by 200 ppm n-hexane and petroleum benzine containing 500 ppm n-hexane, and even less impaired by petroleum benzine containing 200 ppm n-hexane. Degenerations of the myelin sheaths and axons were demonstrated in all exposed groups upon examination of the raveled tail nerves. Thus, the experiment revealed that petroleum benzine could impair the peripheral nerves, while some components of petroleum benzine were considered to inhibit the neurotoxicity of n-hexane.This investigation was partly supported by a grant for scientific research from the Chiyoda Mutual Life Foundation in 1980–1981  相似文献   
66.
Skin lesions and clinically normal skin from 10 patients with systemic lupus erythematosus (SLE) were examined by immunofluorescence for the presence of C3 and its control protein, β1H globulin. β1H was always found in association with deposited C3; in the instance where C3 deposits were not found β1H was also not found. Granular deposits of C3 and β1H were found in the dermal-epidermal junction (DEJ) in all of the 5 nonlesional skins studied. In the lesional skin, C3 was found in 4 of 5; in 2 of these 4, β1H was also found. As previously demonstrated for in vitro systems, β1H also binds in vivo to fragments of C3, presumably C3b, generated during activation of the complement system.  相似文献   
67.
BACKGROUND: When comparing with early-onset Alzheimer's disease (EO-AD) and late-onset Alzheimer's disease (LO-AD), some symptomatological differences in clinical features can be seen between them. Rapid progression, more severe language problems or visuospatial dysfunction occur more often in EO-AD patients. However, there have been very few reports about the differences in behavioral and psychological symptoms between these two groups. AIM: The aim of this study was to demonstrate the differences in behavioral symptoms between EO-AD and LO-AD groups. METHOD: Three hundred and seven consecutive outpatients with AD were put into an EO-AD group (46 patients) or a LO-AD group (261 patients). Comprehensive assessment batteries, including the Neuropsychiatric Inventory (NPI), were administered at the first medical assessment. RESULTS: Significant differences were found between the EO-AD and LO-AD groups in terms of NPI total score (EO-AD: 10.3 +/- 10.9, LO-AD: 17.8 +/- 17.0, p = 0.004) and number of patients who experienced each NPI subscale score (delusion; EO-AD: 13.0%, LO-AD: 50.6%, p < 0.001). There were no differences in cognitive functions or dementia severity between two groups. CONCLUSION: In EO-AD, behavioral and psychological symptoms are relatively fewer than LO-AD at the first medical assessment. Copyright (c) 2007 John Wiley & Sons, Ltd.  相似文献   
68.
Smoking cessation after a cancer diagnosis can significantly improve a person’s prognosis, treatment efficacy and safety, and quality of life. In 2012, Cancer Care Ontario (now part of Ontario Health) introduced a Framework for Smoking Cessation, to be implemented for new ambulatory cancer patients at the province’s 14 Regional Cancer Centres (RCCs). Over time, the program has evolved to become more efficient, use data for robust performance management, and broaden its focus to include new patient populations and additional data collection. In 2017, the framework was revised from a 5As to a 3As brief intervention model, along with an opt-out approach to referrals. The revised model was based on emerging evidence, feedback from stakeholders, and an interim program evaluation. Results showed an initial increase in referrals to cessation services. Two indicators (tobacco use screening and acceptance of a referral) are routinely monitored as part of Ontario Health’s system-wide performance management approach, which has been identified as a key driver of change among RCCs. Due to the COVID-19 pandemic, many RCCs reported a decrease in these indicators. RCCs that were able to maintain a high level of smoking cessation activities during the pandemic offer valuable lessons, including the opportunity to swiftly leverage virtual care. Future directions for the program include capturing data on cessation outcomes and expanding the intervention to new populations. A focus on system recovery from COVID-19 will be paramount. Smoking cessation must remain a core element of high-quality cancer care, so that patients achieve the best possible health benefits from their treatments.  相似文献   
69.
Although the mortality rates of gastric cancer (GC) are gradually declining, gastric cancer is still the fourth leading cause of cancer-related death worldwide. This may be due to the high rate of patients who are diagnosed with GC at advanced stages. However, in countries such as Japan with endoscopic screening systems, more than half of GCs are discovered at an early stage, enabling endoscopic resection (ER). Especially after the introduction of endoscopic submucosal dissection (ESD) in Japan around 2000, a high en bloc resection rate allowing pathological assessment of margin and depth has become possible. While ER is a diagnostic method of treatment and may not always be curative, it is widely accepted as standard treatment because it is less invasive than surgery and can provide an accurate diagnosis for deciding whether additional surgery is necessary. The curability of ER is currently assessed by the completeness of primary tumor removal and the possibility of lymph node metastasis. This review introduces methods, indications, and curability criteria for ER of EGC. Despite recent advances, several problems remain unsolved. This review will also outline the latest evidence concerning future issues.  相似文献   
70.
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