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   20182篇
  免费   1555篇
  国内免费   80篇
耳鼻咽喉   127篇
儿科学   546篇
妇产科学   304篇
基础医学   3252篇
口腔科学   547篇
临床医学   1813篇
内科学   4603篇
皮肤病学   579篇
神经病学   2122篇
特种医学   511篇
外科学   2301篇
综合类   183篇
一般理论   12篇
预防医学   1628篇
眼科学   386篇
药学   1291篇
  1篇
中国医学   48篇
肿瘤学   1563篇
  2023年   131篇
  2022年   262篇
  2021年   685篇
  2020年   382篇
  2019年   501篇
  2018年   563篇
  2017年   445篇
  2016年   494篇
  2015年   526篇
  2014年   665篇
  2013年   879篇
  2012年   1315篇
  2011年   1419篇
  2010年   787篇
  2009年   670篇
  2008年   1135篇
  2007年   1179篇
  2006年   1032篇
  2005年   1007篇
  2004年   962篇
  2003年   803篇
  2002年   748篇
  2001年   346篇
  2000年   269篇
  1999年   271篇
  1998年   176篇
  1997年   166篇
  1996年   106篇
  1995年   118篇
  1994年   94篇
  1993年   86篇
  1992年   253篇
  1991年   217篇
  1990年   228篇
  1989年   189篇
  1988年   168篇
  1987年   194篇
  1986年   180篇
  1985年   195篇
  1984年   138篇
  1983年   114篇
  1981年   93篇
  1979年   129篇
  1978年   92篇
  1977年   84篇
  1975年   85篇
  1974年   95篇
  1973年   108篇
  1970年   81篇
  1969年   89篇
排序方式: 共有10000条查询结果,搜索用时 156 毫秒
51.
The immunohistochemical occurrence of the high affinity neurotrophin (NT) receptors trkA, trkB, and trkC is shown in the pre-term newborn, infant, and adult human post-mortem cerebellum. Immunoreactive neuronal perikarya and processes were observed in all specimens examined, where they appeared unevenly distributed in the cerebellar cortical layers and deep nuclei, and showed regional differences among cerebellar lobules and folia. The trk receptor-antibodies, tested by Western blot on human cerebellum homogenates, revealed multiple immunoreactive bands for trkA and single bands for trkB and trkC. The results obtained show the tissue localization of the trk receptor-like immunoreactivity in the human cerebellum from prenatal to adult age. The analysis for codistribution of the receptors with the relevant ligand and among the receptors in discrete cortical and deep nuclei tissue fields shows a wide variety of conditions, from a good similarity in terms of type and density of labeled structures, to a lack of correspondence, and suggests the possibility of colocalization of trk receptors with the relevant neurotrophin and among them in the cerebellar cortex. These results sustain the concept that the neurotrophin trophic system participates in the development, differentiation, and maintenance of the human cerebellar connectivity and support the possibility of a multifactorial trophic support for the neurotrophins through target-derived and local mechanisms.  相似文献   
52.
We studied blood pressure and natriuretic responses to acute salt loading, and the effect of non-steroidal anti-inflammatory agents on these responses, in five healthy normotensive women aged 65 to 71 years. Five women aged 25 to 31 years acted as controls. Intravenous saline loading, with and without prior ingestion of ibuprofen, was 15 ml/kg/h for 3 h. Baseline blood pressures were higher in the elderly. Saline infusion without ibuprofen raised systolic blood pressure (SBP) by about 25 mmHg in the older group only. Ibuprofen increased baseline SBP in the elderly (129 +/- 6 vs. 116 +/- 5 mmHg, p < 0.05). Saline loading after ibuprofen again raised blood pressure by about 25 mmHg in the elderly only. The elderly group showed markedly increased sodium excretion during saline loading, but this was reduced by ibuprofen. Ibuprofen had no effect on SBP or sodium excretion in controls. Ageing appears to increase susceptibility to salt retention and hypertension from non-steroidal anti-inflammatory agents.   相似文献   
53.
The liver is distinguished from other tissues by (a) its detoxifying function, (b) its resistance to apoptosis, and (c) its regenerative response to damage. Hepatocellular carcinoma arises when chronic insults, such as hepatitis or iron overload, constitutively activate this regenerative program. Here, we propose that the proliferative response of the liver to damage underlies the resistance of hepatocellular carcinoma to cytotoxic therapy, and that hepatocellular carcinoma growth should therefore be more readily controlled by using a networked combination of noncytotoxic interventions to interrupt the damage-inducible regenerative pathway. To this end, hepatocellular carcinoma boasts a wealth of potential drug targets, including viral replication, the antiapoptotic immunosuppressant alpha-fetoprotein, hepatic iron overload, inflammatory signaling, extracellular proteases, and growth factors. By blocking these positive feedback loops in parallel, and so returning the host environment to a more normal state, epigenetic repression of tumor-suppressor gene function may be reversed and tumor dormancy restored. Noncytotoxic maneuvers that short circuit damage resistance loops may thus represent an indirect form of gene therapy meriting incorporation into hepatocellular carcinoma clinical trials.  相似文献   
54.
N E Epstein  J A Epstein  D Nardi  M Osipoff 《Spine》1987,12(6):618-619
Marcaine applied to irritated nerve roots during extradural spinal surgery may attenuate sympathetically mediated and somatosensory (pain)-related hypertensive and tachycardic crises.  相似文献   
55.
56.
Metatarsal head resection for rheumatoid deformities of the forefoot   总被引:1,自引:0,他引:1  
Thirty-five feet in 21 patients, who had had metatarsal head resection for painful rheumatoid forefoot deformities, were analyzed retrospectively. All patients but one were allowed to ambulate 48 hours after surgery. The follow-up period averaged 29 months. A grading system was devised to assess the clinical results based upon pain relief, capacity to ambulate, shoe wear, cosmesis, and use of walking aids. Using this system, the results were 46% excellent, 34% good, 17% fair, and 3% poor. One patient developed a superficial wound infection, which healed uneventfully. Bony impingement was observed on follow-up roentgenograms of 67% of the resectional arthroplasties. This finding was generally asymptomatic, and it did not correlate with the clinical outcome. Smooth wire fixation was used in some of the feet, but it did not improve the results either roentgenographically or clinically.  相似文献   
57.
The clinical and electrophysiological features of a truncal myoclonus in a 55-year-old man are described. The electromyographic characteristics point toward propriospinal myoclonus. It is suggested that a myoclonic generator was released after use of ciprofloxacin, by antagonising the gamma-aminobutyric acid metabolism.  相似文献   
58.
Proteins were extracted from corneocytes of skin of 2-day-old rats and fractionated by gel filtration and cation exchange column chromatography. The different protein fractions were tested for direct inactivation of herpes simplex virus infectivity as determined by reduction of plaque formation. The most effective protein fractions against herpes simplex virus were a neutral pH buffer soluble and mol. wts. ranging from 20 K to 30 K. Amino acid composition of the proteins were virtually identical to epidermal histidine-rich proteins. The activity was significantly (P less than 0.001) stronger against type-2 than type-1. The activity was most stable at pH 7.2 and the rate of inhibition increased in a time-dependent manner up to 4 h. The 50% effective dose was estimated as 1.1 micrograms protein/ml.  相似文献   
59.
The results of the first 3 year' collaboration of the Italian Registry of Paediatric Chronic Peritoneal Dialysis (CPD) (1986–1988) are presented. This Registry acquired data on the majority of the paediatric patients treated with CPD in Italy, thus providing a national picture in a field where few nationwide surveys are available. Patients of less than 15 years of age at the start of dialysis were enrolled and clinical data collected until the age of 19 years. The number of nephrological paediatric centres participating in the Registry increased from 7 in 1986 to 11 in 1988. The total number of patients on CPD was 70 and the percentage of dialysed children treated with CPD ranged from 40.2% to 43.6%. Data on 89 peritoneal catheters were collected: during 1417 dialysis-months 70 catheter-related complications were observed (1:20.8 dialysis-months); actuarial catheter survival was 92.7% at 6 months, 84.8% at 1 year and 68.8% at 2 years. The incidence of peritonitis changed from 1 episode every 10.9 patient-months in 1986 to 1 every 19.8 in 1988. Abdominal hernias were the other main clinical complication observed. The survival of patients was 92.5% at 3 years, while the technique survival at the same time was 84%.  相似文献   
60.
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