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   11985篇
  免费   1080篇
  国内免费   20篇
耳鼻咽喉   100篇
儿科学   271篇
妇产科学   243篇
基础医学   1539篇
口腔科学   196篇
临床医学   1645篇
内科学   2252篇
皮肤病学   167篇
神经病学   989篇
特种医学   570篇
外科学   1819篇
综合类   296篇
一般理论   19篇
预防医学   1367篇
眼科学   169篇
药学   916篇
  1篇
中国医学   13篇
肿瘤学   513篇
  2023年   67篇
  2022年   97篇
  2021年   186篇
  2020年   120篇
  2019年   184篇
  2018年   212篇
  2017年   161篇
  2016年   193篇
  2015年   201篇
  2014年   273篇
  2013年   386篇
  2012年   561篇
  2011年   618篇
  2010年   388篇
  2009年   358篇
  2008年   539篇
  2007年   547篇
  2006年   507篇
  2005年   562篇
  2004年   550篇
  2003年   449篇
  2002年   409篇
  2001年   406篇
  2000年   397篇
  1999年   417篇
  1998年   191篇
  1997年   143篇
  1996年   155篇
  1995年   137篇
  1994年   119篇
  1993年   99篇
  1992年   299篇
  1991年   268篇
  1990年   228篇
  1989年   255篇
  1988年   237篇
  1987年   215篇
  1986年   196篇
  1985年   186篇
  1984年   128篇
  1983年   145篇
  1982年   83篇
  1981年   82篇
  1979年   124篇
  1978年   63篇
  1977年   88篇
  1974年   91篇
  1973年   83篇
  1972年   78篇
  1971年   83篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
Our objective was to test the hypothesis that internal medicine residents can be trained to screen for abdominal aortic aneurysm (AAA) using personal ultrasound imagers. We trained 5 randomly chosen internal medicine residents to image the abdominal aorta for patients with risk factors for AAAs using personal ultrasound imagers. Residents were trained in 3 or 4 one-on-one sessions with an instructor. To be eligible, patients had to be older than 65 years and have hypertension. After training, each of the 5 residents studied 3 patients independently. In 12 of the residents' 15 unsupervised studies, their abdominal aorta measurements were within 5 mm of the instructor's measurements with standard echocardiography (mean difference 3 mm, range 0-6 mm). Residents detected 3 previously unknown AAAs measuring 5.2, 4.2, and 3.9 cm in diameter. We conclude residents can be trained to image the abdominal aorta with personal ultrasound imagers and to identify AAAs in patients at risk.  相似文献   
32.
33.
34.
PURPOSE: Elective cosmetic surgery is expanding in the UK in both the public and private sectors. Because resources are constrained, many cosmetic procedures are being excluded within the National Health Service. If guidelines on who can receive such surgery are to be evidence-based, information is needed about the level of dysfunction in patients referred for elective surgery and whether this is related to their degree of physical abnormality. METHOD: Consecutive patients referred to a regional plastic surgery and burns unit for assessment for elective cosmetic surgery completed standardised measures of physical and psychosocial dysfunction, and indicated their perception of the degree of their abnormality and their preoccupation with it. We distinguished between patients referred for physical reasons or appearance reasons only, and compared levels of physical and psychosocial dysfunction in each with published values for community and clinical samples. Surgeons indicated patients' degree of objective abnormality, and we identified the relationship of dysfunction with perceived and objective abnormality and preoccupation. RESULTS: Whether patients sought surgery for physical or appearance reasons, physical function was normal. Those seeking surgery for appearance reasons only had moderate psychosocial dysfunction, but were not as impaired as clinical groups with psychological problems. Patients seeking the correction of minor skin lesions for purely appearance reasons reported excellent physical and psychosocial function. Level of function was related (negatively) to patients' preoccupation with abnormality rather than to their perceived or objective abnormality. CONCLUSIONS: In general, patients referred for elective cosmetic surgery did not present with significant levels of dysfunction. Moreover, levels of functioning were related to preoccupation rather than to objective abnormality. Therefore, for most patients, whether surgical treatment is generally appropriate is questionable. Future guidelines must seek to identify the small minority who do have a clinical need for surgery.  相似文献   
35.
Melanocytic lesions of uncertain malignant potential (MUMP) is a term which is useful in identifying melanocytic tumours where the distinction between benign and malignant is a histological problem. Sentinel node biopsy is recognised to provide unmatched prognostic information in melanoma patients, but has recently been advocated for diagnostic purposes in MUMP. We present the case of a seven-year-old girl who presented with a six-month history of a changing pigmented lesion on her left upper arm. Excision biopsy not only showed a melanocytic lesion with some spitzoid features but also marked atypia making it appropriate to use the term MUMP. Sentinel node biopsy was undertaken. This case demonstrates that sentinel node biopsy can be performed safely in children. Given the low morbidity of the procedure we advocate that this technique should be considered in this difficult diagnostic situation to further the management of these patients.  相似文献   
36.
Intracerebral vascular reactivity induced by the nitric oxide (NO) donor isosorbide dinitrate (IDN, 5 mg sublingually) is more major and longer-lasting in migraine patients who develop delayed headache in response to the drug. The headache is purportedly due to neuronally-mediated vascular mechanisms. Indomethacin inhibits prostaglandin synthesis, which is involved in NO generation. Indomethacin also decreases cerebral blood flow by constricting precapillary resistance vessels. In the present study, the hemodynamic effects of indomethacin were evaluated in migraine patients and healthy controls by means of transcranial Doppler monitoring. Indomethacin caused a significant decrease in mean flow velocity in the middle cerebral artery. This was an additional effect to the mean velocity decrease induced by IDN. The interactions between the two drugs suggest that their effects on cerebral hemodynamics (and pain) may be of relevance both in understanding the role of NO in migraine pathogenesis and in evaluating symptomatic treatments for migraine attacks.  相似文献   
37.
38.
The incidence (%) of hyperbilirubinemia (serum bilirubin ≥257 μmol/l) was similar in neonates with a combination of ABO incompatibility and glucose-6-phosphate dehydrogenase (G-6-PD) deficiency (45%), with ABO incompatibility (54%) or G-6-PD deficiency (37%), alone (ns). Carboxyhemoglobin values, corrected for inspired CO, were similarly elevated in all three groups (0.87 ± 0.32%, 0.82 ± 0.29%, 0.76 ± 0.18%, respectively, ns), but correlated with bilirubin only in those with ABO incompatibility alone. ABO-incompatible/G-6-PD-deficient neonates, compared with those with either condition alone, are not at increased risk for hemolysis or hyperbilirubinemia.  相似文献   
39.
Multiple sclerosis is a demyelinating disease of the central nervous system with genetic, viral and autoimmune characteristics. Myelin basic protein (MBP) is a suspected target autoantigen since it induces experimental autoimmune encephalomyelitis, an animal model closely resembling multiple sclerosis. The disease is mediated by Class II restricted, MBP-reactive T cells possessing the T helper/inducer phenotype. In the present study, we have isolated MBP-reactive T cell clones from the peripheral blood of a chronic progressive multiple sclerosis patient. The clones displayed blastogenic memory responses when rechallenged with the autoantigen and irradiated autologous lymphocytes. MBP recognition by the autoantigen-reactive T lymphocytes was restricted by major histocompatibility complex Class II antigens. Both CD4+8- and CD4-8+ MBP-reactive T cell clones were obtained.  相似文献   
40.
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