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   1328篇
  免费   93篇
  国内免费   14篇
耳鼻咽喉   6篇
儿科学   40篇
妇产科学   11篇
基础医学   154篇
口腔科学   5篇
临床医学   68篇
内科学   318篇
皮肤病学   11篇
神经病学   311篇
特种医学   30篇
外科学   221篇
综合类   7篇
预防医学   27篇
眼科学   12篇
药学   75篇
肿瘤学   139篇
  2023年   15篇
  2022年   16篇
  2021年   29篇
  2020年   26篇
  2019年   17篇
  2018年   28篇
  2017年   34篇
  2016年   24篇
  2015年   37篇
  2014年   66篇
  2013年   50篇
  2012年   91篇
  2011年   110篇
  2010年   41篇
  2009年   41篇
  2008年   85篇
  2007年   76篇
  2006年   95篇
  2005年   97篇
  2004年   76篇
  2003年   85篇
  2002年   98篇
  2001年   11篇
  2000年   9篇
  1999年   20篇
  1998年   19篇
  1997年   19篇
  1996年   12篇
  1995年   6篇
  1994年   6篇
  1993年   12篇
  1992年   8篇
  1991年   11篇
  1990年   9篇
  1989年   9篇
  1988年   7篇
  1987年   5篇
  1986年   4篇
  1985年   3篇
  1984年   3篇
  1983年   3篇
  1982年   3篇
  1980年   4篇
  1979年   4篇
  1976年   1篇
  1975年   1篇
  1974年   3篇
  1972年   1篇
  1971年   1篇
  1928年   1篇
排序方式: 共有1435条查询结果,搜索用时 31 毫秒
1.
2.
From April 1989 to December 2004, we performed liver biopsy on 475 patients and obtained biopsy proven 35 cases of non-alcoholic fatty liver. Among them, 18 cases were diagnosed as non-alcoholic steatohepatitis (NASH). During the last three years, we have tried to detect NASH using ultrasonography and elevated value of serum ferritin (> 300 ng/ml). All of the eligible 7 cases biopsied during the course were diagnosed as NASH. In these 7 cases, ALT levels improved after the body weight loss accompanied by the parallel decrease of serum ferritin levels. Measurement of serum ferritin is useful in the detection of NASH but the normal value of ferritin cannot rule out the possibility of NASH.  相似文献   
3.
The enzyme O6-methylguanine-DNA methyltransferase repairs alkylation- induced DNA damage, O6-methylguanine and O4-methylthymine, the former being formed more frequently. Previously, by means of gene targeting, we generated mice in which alleles for methyltransferase were disrupted. We now use these mouse lines, which are totally deficient in methyltransferase activity, to examine protective effects of the enzyme against tumor formation. In gene-targeted female mice given an i.p. injection of 5 mg/kg of dimethylnitrosamine, a larger number of liver and lung tumors occurred, as compared with normal female mice treated in the same manner. In male mice given a lower dose of carcinogen, the difference between normal and gene-targeted mice was statistically insignificant although more tumors did form in the gene-targeted mice. Methyltransferase apparently afforded protection from nitrosamine- induced tumorigenesis.   相似文献   
4.
5.
This report concerns a notable case of progressive supranuclear palsy exhibiting asymmetric dentate nucleus and thalamic degeneration with numerous torpedoes. The neuronal loss in the ventral lateral nucleus of the thalamus was predominant on the right side, while in the cerebellum, a quantitative study revealed the contralateral predominance of the neuronal loss in the dentate nuclei and torpedo formation, with preserved Purkinje cells. The abnormal tau-protein-related profiles in the two nuclei did not show any laterality in their distribution, indicating that the dentatothalamic tract may have been affected in a non-specific way in this case. In addition, the fact that the prominent sites of torpedo formation and loss of dentate nucleus neurons are identical supports the hypothesis that the torpedoes may be formed in association with neuronal loss in the dentate nucleus because of a plausible metabolic change in Purkinje cells through synaptic detachment of their axon terminals. Received: 4 January 1996 / Revised: 27 March 1996 / Accepted: 5 April 1996  相似文献   
6.
The in vitro proliferation of peripheral blood lymphocytes (PBLs) without any mitogenic stimulation is one of the hallmarks of human T lymphotropic virus type I (HTLV-I) infection. Recent evidence suggests a difference in the degree of the phenomenon between HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and asymptomatic HTLV-I carriers (AC). In this article, we demonstrated several alterations in the features of the in vitro transformed lymphocytes between patients with HAM/TSP (n = 16) and AC (n = 8). The percentages of total CD8+ and CD8+CD28+ cells were significantly increased in the in vitro proliferating T lymphocytes derived from the patients with HAM/TSP when compared to those from AC. HAM/TSP was segregated from AC by the high degree of the proliferation of CD8+CD28+ cells. The expression of HTLV-I-specific antigens on the cultured PBLs was detected only in the subjects which showed low CD8+CD28+/CD4+ ratio of the in vitro proliferating lymphocytes. These findings suggest that this phenomenon distinguishes HAM/TSP from AC, not only in quantity but also in quality.  相似文献   
7.
As a model system for mucocutaneous lymph node syndrome (MCLS), we have advocated and used mice which had been rendered tolerant to Streptococcus pyogenes-associated antigens by neonatal infection with group A fteta-hemolytic streptococci, because these mice have shown a variety of peculiar bioimmunological characteristics bearing a striking resemblance to those of MCLS patients. The results of our current investigations reaffirmed the reliability of the animal model by indicating that mice subjected to neonatal infection with 5. pyogenes , or inoculation with streptococcal pyrogenic exotoxin (SPE) in Freund's adjuvant, were perfect counterparts of patients with MCLS on account of their platelet activation and hyperaggregability in response to provocative treatment, which are familiar findings in this disease.  相似文献   
8.
A 66-year-old man died of massive gastrointestinal hemorrhage caused by a fistula between the third portion of the duodenum and the abdominal aorta. An autopsy revealed that duodenal tuberculosis had resulted in the development of a fistula into the aorta with no pathological changes, and no active pulmonary tuberculosis was found. Duodenal tuberculosis and primary aortoduodenal fistula (ADF) without an aneurysm are both extremely rare. Thus, we report herein a unique case of primary aortoduodenal fistula without an abdominal aortic aneurysm, but associated with duodenal tuberculosis, and review the current literature.  相似文献   
9.
Summary Only one peptide of CD4 (amino acid residues 70–132) among 16 synthetic peptide fragments selectively inhibited HIV-1 replication and HIV-1-induced syncytium formation. Several smaller peptides within this region did not show any activity, except for the peptide (86–132) which showed somewhat lower activity.  相似文献   
10.
We report the first case of early-onset Parkinson's disease (EOP) with the PTEN-induced kinase 1 (PINK1) gene deletion in 62 years old Japanese female. The symptoms were started with unstable gait at the age 38. Parkinsonian symptoms became apparent in 45 years old. L-Dopa was markedly effective on her parkinsonian symptoms. However, equinovarus foot induced by L-Dopa intake appeared three months prior to the admission. On admission, she presented with mild cognitive impairment, severe depression, marked retropulsion, resting tremor in the left upper limb and mild hyperreflexia in the four limbs. Rigidity was not present. Mutational analysis revealed homozygous deletion from exon 6 to 8 in the PINK1 gene. An ethnic diversity in PINK1 mutation is suggested.  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