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   1098篇
  免费   90篇
  国内免费   4篇
耳鼻咽喉   36篇
儿科学   20篇
妇产科学   7篇
基础医学   157篇
口腔科学   15篇
临床医学   121篇
内科学   178篇
皮肤病学   169篇
神经病学   58篇
特种医学   75篇
外科学   182篇
综合类   5篇
预防医学   45篇
眼科学   5篇
药学   65篇
肿瘤学   54篇
  2023年   5篇
  2022年   10篇
  2021年   19篇
  2020年   11篇
  2019年   11篇
  2018年   22篇
  2017年   17篇
  2016年   25篇
  2015年   30篇
  2014年   27篇
  2013年   31篇
  2012年   46篇
  2011年   56篇
  2010年   31篇
  2009年   31篇
  2008年   44篇
  2007年   43篇
  2006年   32篇
  2005年   48篇
  2004年   55篇
  2003年   43篇
  2002年   45篇
  2001年   32篇
  2000年   24篇
  1999年   26篇
  1998年   28篇
  1997年   14篇
  1996年   18篇
  1995年   21篇
  1994年   20篇
  1993年   10篇
  1992年   20篇
  1991年   16篇
  1990年   28篇
  1989年   16篇
  1988年   23篇
  1987年   25篇
  1986年   22篇
  1985年   25篇
  1984年   22篇
  1983年   11篇
  1982年   12篇
  1981年   5篇
  1980年   7篇
  1977年   9篇
  1976年   5篇
  1970年   9篇
  1969年   7篇
  1968年   8篇
  1967年   4篇
排序方式: 共有1192条查询结果,搜索用时 15 毫秒
1.
Although malignant fibrous histiocytoma (MFH) is the most common soft tissue sarcoma of adult life, it is fairly rare in the head and neck region (3-6%). Between 1983 and 1991 8 patients with MFH in the head and neck region have been observed and treated at the ENT-department of the University of Tübingen. 5 patients have been operated (laryngopharyngeal localization), 2 patients underwent irradiation (unresectable fast growing T4-tumors of the pharynx and thyroid) and one female patient refused further therapy after two resections elsewhere. Operated patients showed no evidence of disease 2-8 years after resection (all margins have been controlled histologically). Both irradiated patients died 4 respectively 2 months after full (70 Gy) and incomplete (17 Gy) radiotherapy without visible positive effects. Both patients developed pulmonary metastasis. Since MFH can grow in thin layers along musculaoponeurotic structures the exact size is not always demonstrable by ultrasound, CT or MR scans. Metastasis occur in up to 40%, preferentially in regionary lymph nodes, in lung, liver and skeletal system. These phenomenon requires a full pretherapeutic staging. Histologically MFH is sometimes hard to distinguish from other tumors as for example various sarcomas and pleomorphic carcinoma. Therefore, immunohistochemical (mesenchymal markers) and electron microscopical investigations are advised. Resection with exact histological controll of all margins is the therapy of choice. We experienced that laryngeal MFH (n = 3) can be resected without laryngectomy under certain circumstances. Although unsuccessfull in our two cases, according to the literature, radiotherapy should be administered in unresectable cases. Depending on localization and size of MFH long survival, in single cases healing, of this disease is possible by surgical treatment.  相似文献   
2.
3.
The location of cholinergic neurons was studied during the development of the chick embryo spinal cord. A comparison between choline acetyltransferase (ChAT) immunocytochemistry and acetylcholinesterase (AChE) histochemistry was performed. ChAT-positive neurons could be detected only from embryonic day 9 (E9) onwards by the FITC technique and from E12 onwards by the PAP technique. These neurons were located mainly in the medial and lateral motor columns in the ventral horn of the gray matter and some of them were observed in the intermediate region of the spinal cord. AChE-containing cell bodies were much more numerous than the ChAT immunoreactive ones and were distributed in the ventral horn of the gray matter, the intermediate gray region and mostly off the apical part of the dorsal horn. ChAT should provide a reliable and specific marker for cholinergic neurons.  相似文献   
4.
Summary Infection of Aedes albopictus cells with Semliki Forest virus (SFV) leads to polykaryocyte formation below pH 6.2. This syncytium formation is accompanied by a decrease of the cellular ATP level. Addition of inhibitors of oxidative phosphorylation leads to a rapid, total depletion of ATP in infected cells at pH 6 and results in an inhibition of polykaryocyte formation. However, when cells were exposed for only a few minutes to pH 6 in the presence of the inhibitors and then kept at pH 7.2, the ATP level partially recovered to values sufficient for syncytium formation. Similar results were obtained after ATP depletion induced by 2-deoxyglucose. Thus, it can be concluded that SFV-induced syncytium formation is an ATP-dependent event.With 6 Figures  相似文献   
5.
6.
Active-specific immunotherapy for melanoma   总被引:1,自引:0,他引:1  
Twenty-five patients with metastatic melanoma were treated with a therapeutic vaccine ("theraccine") consisting of allogeneic melanoma lysates and a novel adjuvant, DETOX (Ribi ImmunoChem Research, Inc, Hamilton, MT). Each patient received 200 antigenic units (20 x 10(6) tumor cell equivalents) subcutaneously on weeks 1, 2, 3, 4, and 6. Clinical responses included one complete remission, three partial remissions, and a long-term (17-month) stability. Two other patients had mixed responses, with partial remissions of numerous subcutaneous nodules. Sites of responsive disease included primarily the skin, but ileal, breast, and a liver metastasis also responded. Removal of residual lesions in patients with partial remissions, whose other lesions had disappeared during treatment, led to long disease-free survivals. The median duration of remission was 17 months, with four of the five responders alive for at least 24 months after treatment. An increase in precursors of cytolytic T cells (CTLs) correlated with clinical outcome, when complete, partial, and mixed responses and long-term stability were considered. The CTLs recognized melanoma-associated antigens on many cell lines, but not other types of tumor or normal lymphocytes. Skin-test reactivity to melanoma antigens and serum antibodies against the melanoma cells was unrelated to clinical response. Toxicity was minimal, restricted largely to minor soreness at the site of injection. Only five patients, four of whom were treated with repeated courses, developed severe granulomas. These results confirm that active-specific immunization with allogeneic lysates of melanoma administered with the adjuvant DETOX can induce immunity to melanoma, and can induce regressions of disease in a proportion of patients with metastatic disease with little toxicity.  相似文献   
7.
目的 探讨盐酸喹那普利 (QuinaprilHydrochloride)治疗轻、中度原发性高血压的有效性和安全性。方法 全国 6家医院参加的一项多中心、随机、双盲、平行组间对照研究。结果  113例原发性高血压病人治疗 8周后 ,总有效率达 85 84% ,统计学有显著性差异。盐酸喹那普利副反应较轻 ,对肾脏、肝脏、造血系统和心脏未见有害作用。结论 盐酸喹那普利是一种安全、疗效好、副反应小的治疗轻、中度原发性高血压的有效药物。  相似文献   
8.
Motile properties of outer hair cells (OHCs) may contribute to sharp tuning and amplification in the mammalian cochlea. Shape changes of isolated OHCs in response to various physical and chemical influences have been investigated intensively. However, determinations of shape may have been influenced by unanticipated effects of preparation and preservation of the OHCs investigated. Thus, in a first step, lengths of freshly isolated OHCs from the guinea pig cochlea were determined using a video-enhancing magnification system. The cuticular plate/cell axis angle (CP/CA angle) was then measured in native cells and under the influence of potassium chloride and potassium gluconate incubation. To show the influence of glutaraldehyde (GA) fixation on the isolated OHCs, fixative dependent changes on cell length and CP/CA angle were recorded in native and preincubated OHCs. In these experiments, the cell length of vital isolated OHCs was between 41.5 m, in the basal turn, and 103.7 m, in the apical turn. The average CP/CA angle was 106° ± 4.2° (n = 324 cells, turns 1–4) with no statistically significant differences for the four turns. Under the influence of potassium chloride, cell length was reduced by 8.1%. Potassium gluconate incubation led to a shortening of cell length, followed by a 5.3% increase after 5 min. The CP/CA angle under potassium chloride was decreased (97.0°) and was then increased under the influence of potassium gluconate (110.7°) as a result of cuticular plate tilting. Cell shrinkage after fixation depended on the fixative's osmolarity and on the GA concentration. Increased GA levels amplified cell shrinkage from 34% for hypo-osmolar solutions to 15% in iso-osmolar and 29% in hyperosmolar solutions. The CP/CA angle of native and incubated OHCs was not different from those fixed with GA. The present data provide a rational basis for isolated OHC shape parameters. Moreover, functionally induced changes can be better interpreted when OHCs are influenced by fixatives, as shown in the GA experiments.  相似文献   
9.
It has been proposed that -blocker therapy reverses metabolic and cardiovascular disorders in acute theophylline poisoning. We present a case of acute theophylline overdose treated with esmolol under haemodynamic control. Haemodynamic monitoring was useful in determining the appropriate duration of administration of esmolol and in deciding on treatment with fluids.  相似文献   
10.
The authors present a case of intramural hematoma of the small intestines during anticoagulant treatment. With reference to this case, they study the frequency, etiopathogenesis and anatomy of this hematoma and particularly look at the radiological manifestations. In this respect they distinguish three stages in the evolution. The first, when the straight X-ray of the abdomen and barium followthrough demonstrate an axial stenosis of the small intestines with dilation of the proximal loops; the second (between the 7th and 20th days) when the loop affected by the hematoma takes on a characteristic "palissade" or "spring" -like sausage appearance; finally the third (after the 3rd week), when only thickening of the haustrations persists with progressive return to normal. The radiological diagnosis is discussed, not only with intramural hematomas of the small intestines of other etiologies (traumatic, during pancreatitis, during disorders in hemostatis), but also with conditions giving rise to similar radiological pictures: malabsorption, inflammatory conditions, etc.  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