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   1275142篇
  免费   94110篇
  国内免费   1984篇
耳鼻咽喉   18186篇
儿科学   42257篇
妇产科学   37812篇
基础医学   186985篇
口腔科学   35380篇
临床医学   108103篇
内科学   251436篇
皮肤病学   26498篇
神经病学   99170篇
特种医学   49981篇
外国民族医学   366篇
外科学   197579篇
综合类   26513篇
现状与发展   1篇
一般理论   300篇
预防医学   92580篇
眼科学   29056篇
药学   97755篇
  1篇
中国医学   2496篇
肿瘤学   68781篇
  2018年   11808篇
  2015年   11610篇
  2014年   15994篇
  2013年   24343篇
  2012年   33540篇
  2011年   35936篇
  2010年   21208篇
  2009年   20014篇
  2008年   34973篇
  2007年   37941篇
  2006年   38498篇
  2005年   37792篇
  2004年   36376篇
  2003年   35367篇
  2002年   34915篇
  2001年   58093篇
  2000年   59583篇
  1999年   50687篇
  1998年   14232篇
  1997年   12809篇
  1996年   13071篇
  1995年   12345篇
  1994年   11757篇
  1993年   10860篇
  1992年   40984篇
  1991年   40358篇
  1990年   39885篇
  1989年   38706篇
  1988年   36108篇
  1987年   35349篇
  1986年   33723篇
  1985年   32134篇
  1984年   23922篇
  1983年   20818篇
  1982年   12377篇
  1981年   10927篇
  1980年   10204篇
  1979年   22635篇
  1978年   15877篇
  1977年   13729篇
  1976年   12970篇
  1975年   14201篇
  1974年   16682篇
  1973年   16076篇
  1972年   15318篇
  1971年   14229篇
  1970年   13214篇
  1969年   12731篇
  1968年   11978篇
  1967年   10478篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Summary Aspergillosis belongs to the group of mycotic diseases of paranasal sinuses. The invasive forms, and particularly the fulminant forms, are potentially fatal. Isolated aspergillosis of the sphenoid sinus or the clivus is a difficult diagnosis, since the often misleading clinical manifestations of this rare disease develop late. These patients become apparent by neurological signs such as cavernous sinus syndrome, pseudotumor of the pituitary or the orbit. Diagnosis is often made intra-operatively or on histological examination. We report a case of invasive aspergillosis uniquely involving the sellar area revealed by clinical features suggesting a pseudotumor of the pituitary. Although such lesions are almost always seen in immune suppressed subjects, in our case, the patient was immune competent and had no past history of sinusitis. The question of whether, and when to perform limited or extensive surgery remains an issue for discussion, owing to the rarity of this disease honed by lack of experience. It depends on several factors: the kind of disease, the immunity, the subtype of invasive fungal sinusitis and the degree of tissue invasion.  相似文献   
992.
993.
The antitumor activity of 5-(5′,6′-benzocoumaro-3′-yl)methylaminouracil (BCMU) and its liposomal medicinal form was studied in comparison to 5-fluorouracil (5-FU), a well-known antitumor drug widely used in oncological practice. The half-lethal dose of BCMU is 14.8 ± 4.2 mg/kg, while the optimum effective dose of the drug is 6 mg/kg. In this dose, BCMU combines low toxicity with significant antitumor activity, which is manifested by increased tumor growth inhibition (TGI) at a 19% increase in the lifetime (LT) of experimental animals. The antitumor activity of the liposomal form of BCMU is quantitatively and qualitatively superior to that of the nonmodified compound and 5-FU, which is manifested by the most pronounced TGI value and by a significant LT increase. __________ Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 40, No. 6, pp. 6–7, June, 2006.  相似文献   
994.
We targeted the MVNP gene to the OCL lineage in transgenic mice. These mice developed abnormal OCLs and bone lesions similar to those found in Paget's patients. These results show that persistent expression of MVNP in OCLs can induce pagetic-like bone lesions in vivo. INTRODUCTION: Paget's disease (PD) of bone is the second most common bone disease. Both genetic and viral factors have been implicated in its pathogenesis, but their exact roles in vivo are unclear. We previously reported that transfection of normal human osteoclast (OCL) precursors with the measles virus nucleocapsid (MVNP) or measles virus (MV) infection of bone marrow cells from transgenic mice expressing a MV receptor results in formation of pagetic-like OCLs. MATERIALS AND METHODS: Based on these in vitro studies, we determined if the MVNP gene from either an Edmonston-related strain of MV or a MVNP gene sequence derived from a patient with PD (P-MVNP), when targeted to cells in the OCL lineage of transgenic mice with the TRACP promoter (TRACP/MVNP mice), induced changes in bone similar to those found in PD. RESULTS: Bone marrow culture studies and histomorphometric analysis of bones from these mice showed that their OCLs displayed many of the features of pagetic OCLs and that they developed bone lesions that were similar to those in patients with PD. Furthermore, IL-6 seemed to be required for the development of the pagetic phenotype in OCLs from TRACP/MVNP mice. CONCLUSIONS: These results show that persistent expression of the MVNP gene in cells of the OCL lineage can induce pagetic-like bone lesions in vivo.  相似文献   
995.
The present study investigated the role of central metabotropic glutamate receptors (mGluRs) in interleukin-1beta (IL-1beta)-induced mechanical allodynia and mirror-image mechanical allodynia in the orofacial area. Experiments were carried out on male Sprague-Dawley rats weighing 230 to 280 g. After administration of 0.01, 0.1, 1, or 10 pg of IL-1beta into a subcutaneous area of the vibrissa pad, we examined the withdrawal behavioral responses produced by 10 successive trials of an air-puff ramp pressure applied ipsilaterally or contralaterally to the IL-1beta injection site. Subcutaneous injection of IL-1beta produced mechanical allodynia and mirror-image mechanical allodynia in the orofacial area. Intracisternal administration of CPCCOEt, a mGluR1 antagonist, or MPEP, a mGluR5 antagonist, reduced IL-1beta-induced mechanical allodynia and mirror-image mechanical allodynia. Intracisternal administration of APDC, a group II mGluR agonist, or L-AP4, a group III mGluR agonist, reduced both IL-1beta-induced mechanical allodynia and mirror-image mechanical allodynia. The antiallodynic effect, induced by APDC or L-AP4, was blocked by intracisternal pretreatment with LY341495, a group II mGluR antagonist, or CPPG, a group III mGluR antagonist. These results suggest that groups I, II, and III mGluRs differentially modulated IL-1beta-induced mechanical allodynia, as well as mirror-image mechanical allodynia, in the orofacial area. PERSPECTIVE: Central group I mGluR antagonists and groups II and III mGluR agonists modulate IL-1beta-induced mechanical allodynia and mirror-image mechanical allodynia in the orofacial area. Therefore, the central application of group I mGluR antagonists or groups II and III mGluR agonists might be of therapeutic value in treating pain disorder.  相似文献   
996.
This study presents the case of a patient with necrobiosis or necrosing fascitis of the inguinal region, secondary to a complicated Amyand’s hernia with a concomitant ipsilateral Richter’s hernia. The patient was treated with open trans-abdominal surgery and hernia repair through the pre-peritoneal approach, plus anti-microbians, and thrice-daily wound cleansing and dressings to the inguinal region. Evolution was satisfactory. There are no reports in the literature of a case such as this.  相似文献   
997.
The general management of patients with chronic obstructive pulmonary disease and asthma is discussed. Pathophysiological mechanisms of bronchial obstruction and inflammation are briefly described. The importance of preventive measures is emphasized. Medicine prescribed in chronic obstructive pulmonary disease and asthma, their relative place in treatment schedules and route of administration are reviewed. Finally, the importance of maximal bronchodilatation in exacerbations is stressed and the few indications for antibiotic treatment are discussed.  相似文献   
998.
It has been claimed that carcinoma of the large intestine is extremely rare in the indigenous black population in Africa. Furthermore, the incidence of colorectal carcinoma in black Africans is said to increase when they abandon their customary diet and adopt a more westernised diet. Although colorectal carcinoma is not a common condition in our region, our experience at Mpilo Hospital over the last eight years suggest that it is by no means a rare condition. During this period we treated 90 black patients giving an average admission rate of 11.25 new cases a year. Virtually all our patients would have been on their customary high roughage diet because they either came from rural areas (55.7 percent) or if they lived in town (44.3 percent) they belonged to the working class.  相似文献   
999.
1000.
A sample of 110 consecutive first admission young schizophrenic patients treated between 1964 and 1967 was rediagnosed in 1981. Among 92 survivors, 27 could be labelled as paraphrenics. From information available at inception 97 variables were coded covering such areas as personality, previous disturbances, age and type of onset, and symptoms around admission. Sixty-three out of 97 variables were hypothesized to differentiate, at admission, future paraphrenics from the rest of the sample. Paraphrenics were found to have had less contact disturbance, better self-esteem, less neurotic symptoms in adolescence and childhood, and less complaints of unhappiness when growing up. They had more regressive and paranoid symptoms at admission, were older at onset of the disease, which was more acute, more often connected with precipitating events, and confusion. Certain non-regressive symptoms such as brooding, anhedonia and concentration difficulties were less common. A discriminant analysis yielded a proportion of correct predictions = 0.64 (p less than 0.05). The results are in accordance with the theory of more favourable energetic and organizational capacity in paranoid schizophrenics as compared with non-paranoids.  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