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   4717篇
  免费   276篇
  国内免费   40篇
耳鼻咽喉   41篇
儿科学   102篇
妇产科学   103篇
基础医学   677篇
口腔科学   108篇
临床医学   412篇
内科学   1111篇
皮肤病学   91篇
神经病学   247篇
特种医学   95篇
外科学   732篇
综合类   90篇
一般理论   3篇
预防医学   422篇
眼科学   118篇
药学   357篇
中国医学   53篇
肿瘤学   271篇
  2024年   7篇
  2023年   55篇
  2022年   171篇
  2021年   239篇
  2020年   128篇
  2019年   195篇
  2018年   203篇
  2017年   123篇
  2016年   148篇
  2015年   128篇
  2014年   188篇
  2013年   278篇
  2012年   419篇
  2011年   454篇
  2010年   205篇
  2009年   158篇
  2008年   262篇
  2007年   290篇
  2006年   202篇
  2005年   197篇
  2004年   184篇
  2003年   150篇
  2002年   162篇
  2001年   50篇
  2000年   57篇
  1999年   50篇
  1998年   32篇
  1997年   16篇
  1996年   18篇
  1995年   19篇
  1994年   18篇
  1993年   12篇
  1992年   25篇
  1991年   19篇
  1990年   12篇
  1989年   18篇
  1988年   15篇
  1987年   15篇
  1986年   12篇
  1985年   8篇
  1984年   9篇
  1983年   7篇
  1979年   9篇
  1978年   7篇
  1974年   10篇
  1972年   6篇
  1971年   5篇
  1969年   5篇
  1968年   5篇
  1967年   6篇
排序方式: 共有5033条查询结果,搜索用时 15 毫秒
1.
2.
The present investigation was aimed at studying the possible role of curcumin against N-nitrosodiethylamine (NDEA)-induced toxicity in albino rats. Administration of NDEA to rats at a concentration of 0.1 mg/ml in drinking water ad libitum for 21 days produced toxicity in them, which was evident from histopathological changes in the rat livers, and increased levels of blood serum enzyme markers, i.e. aspartate transaminase, alanine transaminase, alkaline phosphatase, and lactate dehydrogenase. In addition, the levels of oxidative stress markers like lipid peroxidation (LPO), protein carbonyl (PCC), and glutathione-S-transferase (GST) activity were elevated and the total glutathione (GSH) content was reduced in the livers. The administration of curcumin to rats at concentrations of 10, 20, and 40 mg/ml in drinking water along with 0.1 mg/ml of NDEA for 21 days effectively suppressed NDEA-induced toxicity and also resulted in a dose-dependent reduction in the levels of blood serum enzyme markers (AST, ALT, ALP, and LDH). Moreover, LPO, PCC, and GST activity were reduced and the GSH level was increased upon the administration of curcumin along with NDEA. The results obtained for the comet assay in rat hepatocytes and blood lymphocytes showed a significant dose-dependent decrease in the mean tail length. The micronucleus assay performed on rat hepatocytes also showed a dose-dependent reduction in the frequency of micronucleated cells along with curcumin administration. These results suggest that curcumin has a protective role against NDEA-induced toxicity in albino rats.  相似文献   
3.
New-onset refractory status epilepticus (NORSE) is a drug-resistant status epilepticus that often has a catastrophic outcome. Our patient was diagnosed with NORSE and had an EEG reading that showed status epilepticus persisting for 8 months in general anesthesia. After autoimmune workup showed positive antiphospholipid antibodies, his seizure was controlled, and he was discharged with good condition apart from moderate cognitive impairment. However, he later developed schizophrenia. Although psychiatric disorders have been associated with antiphospholipid syndrome, to the best of our knowledge, it has not been reported to be associated with status epilepticus. We recommend vigilance of psychological complications of refractory status epilepticus’ patients for early psychiatric referral, diagnosis, and treatment.

New-onset refractory status epilepticus (NORSE) is a syndrome of new-onset drug-resistant status epilepticus that often has a catastrophic outcome. Epilepsy is usually associated with psychiatric disorders of different manifestations of which psychosis is an example.1 However, not much is found in the literature review regarding psychiatric disorders following NORSE although a recent study concluded 32% of NORSE patients ended up with altered behavioral states like aggression.2 Schizophrenia following NORSE like in the rare presentation of this case has not been reported in the literature review before, although an association between schizophrenia and autoimmune disorders like APS has been reported.3  相似文献   
4.
Circulating immune complexes (CIC), adult schistosome antibody, and total immunoglobulin concentrations were estimated in sera from 35 chronic Schistosoma mansoni patients with different infection intensities and different pathological complications. High CIC levels were present in about one-third (10/35) of the sera. Most of the patients (9/10) with elevated CIC levels also had hepatomegaly or hepatosplenomegaly. This finding is significant in the pathogenesis of schistosomal liver fibrosis and may also apply to other liver diseases, especially cirrhosis. No correlation was found between infection intensity as judged by stool egg counts and CIC levels. A reverse relationship was observed between the level of anti-adult worm IgG and CIC levels. CIC levels were elevated within 7 and 28 days after treatment in most patients. Hypergammaglobulinaemia was detected in most sera.  相似文献   
5.
Small bowel transplantation (SBT) is associated with poorly understood enteric dysfunction. The study of SBT in mice is hindered by the technical difficulty of orthotopic SBT in the mouse. Our aim was to develop an easy preparation of extrinsic denervation of the entire jejunoileum in mice as a model of orthotopic SBT. All neurolymphatic tissues accompanying the superior mesenteric artery (SMA) and vein (SMV) were ligated just distal to the middle colic vessels. The SMA and SMV were then stripped of investing adventitia, and the mesentery to jejunum and colon were transected radially. Jejunum and colon were not transected and reanastomosed. To confirm extrinsic denervation 1, 3, and 6 months later, segments of small bowel were stained for protein gene product 9.5 (PGP9.5) and tyrosine hydroxylase (TH). Tyrosine hydroxylase immunoreactive intensity was then quantified using a semiquantitative analysis. Immunohistochemical fluorescence showed persistence of PGP9.5 immunoreactivity confirming enteric nerves in jejunoileum; however, there was no TH immunoreactivity in jejunoileum in denervated mice despite the expected preservation of TH immunoreactivity in the still-innervated duodenum at 1 month. At 3 months, sparse immunoreactivity for TH was present, and by 6 months, reinnervation of TH-containing nerves appeared similar to controls. Quantification of intensity at each time-point further confirmed this trend. This technique in the mouse accomplishes a complete extrinsic denervation of jejunoileum early postoperatively (1 and 3 months); reinnervation occurs by 6 months. This is an easily learned murine model of orthotopic SBT. Presented at the American Gastroenterological Association during Digestive Disease Week in Los Angeles, CA, as a poster presentation on May 23 2006. Abstract published in GastroenterologyE 2006; 130:A604.  相似文献   
6.
We have treated 39 infants and children with congenital heart disease with extracorporeal membrane oxygenation during the past 5 years. Thirty-six were treated for low cardiac output or pulmonary vasoreactive crisis after repair of congenital heart defects. Twenty-two (61%) survived. Most patients were cannulated from the neck via the right internal jugular vein and the right common carotid artery. Six patients were cannulated from the chest, including three who had separate drainage of the left side of the heart with a left atrial cannula. Two of these patients survived and were the only survivors of the nine patients cannulated in the operating room because they could not be weaned from cardiopulmonary bypass after open cardiac operations. We also reviewed 312 patients (the predictor study series) having open cardiac operations before the availability of extracorporeal membrane oxygenation; 27 of these patients died. Data were collected at 1 and 8 hours postoperatively to determine if any parameters might predict early mortality. With these parameters used as criteria, patients who went on extracorporeal membrane oxygenation were as sick as those who died before extracorporeal membrane oxygenation was available. The most common complication was bleeding related to heparinization. The mean transfusion requirement in survivors was 1.50 +/- 1.13 ml/kg/hr, 5.63 +/- 7.0 ml/kg/hr in the nonsurvivors, and 7.46 +/- 8.29 ml/kg/hr in those cannulated in the operating room because they could not be weaned from bypass. Four children had intracranial hemorrhage, and two of them died. There was one late death. Nine of the 22 survivors are entirely normal. All survivors who do not have Down's syndrome are considered to have normal central nervous system function. We conclude that extracorporeal membrane oxygenation can improve survival in patients with both pulmonary artery hypertension and low cardiac output after operations for congenital heart disease.  相似文献   
7.
D A Warrell  J Shaheen  P D Hillyard  D Jones 《Toxicon》1991,29(10):1263-1265
A young woman was bitten on the shoulder by a female Steatoda nobilis spider, in Worthing on the south coast of England. She noticed intense radiating pain, local sweating (indicating parasympathetic stimulation) and feverishness. This immigrant species from the Canary Islands has established itself along the south coast of England in recent years. Like the related Mediterranean species S. paykulliana, S. nobilis may be of medical importance and deserves further study.  相似文献   
8.
Waldenstrom's macroglobulinemia (WM) is an uncommon low-grade lymphoma. Cognitive impairment due to central nervous system infiltration by lymphoplasmocytoid cells (Bing-Neel syndrome) has been rarely reported. We describe a 54-year-old man who was referred to a memory disorder clinic with a 9-month history of clinically obvious nonfluent aphasia and WM. He underwent extensive neuropsychological testing, clinical examination and structural and functional brain imaging. The diagnosis of the diffuse form of the Bing-Neel syndrome was supported by abnormal lymphoid cells found in the cerebrospinal fluid. Structural and functional brain imaging revealed impairment of brain areas due to white matter changes and subsequent functional deficits mimicking the neuropsychological syndrome encountered in progressive nonfluent aphasia. The diffuse form of Bing-Neel syndrome and neurological deficits are assumed to be the result of leptomeningeal infiltration by malignant cells and/or neoplastic vascular obstruction.  相似文献   
9.
10.
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