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   2567篇
  免费   238篇
  国内免费   2篇
耳鼻咽喉   31篇
儿科学   84篇
妇产科学   105篇
基础医学   283篇
口腔科学   98篇
临床医学   354篇
内科学   381篇
皮肤病学   57篇
神经病学   229篇
特种医学   72篇
外科学   382篇
综合类   138篇
一般理论   4篇
预防医学   311篇
眼科学   21篇
药学   167篇
中国医学   1篇
肿瘤学   89篇
  2021年   43篇
  2019年   53篇
  2018年   56篇
  2017年   46篇
  2016年   45篇
  2015年   42篇
  2014年   67篇
  2013年   56篇
  2012年   108篇
  2011年   114篇
  2010年   94篇
  2009年   72篇
  2008年   79篇
  2007年   76篇
  2006年   114篇
  2005年   106篇
  2004年   95篇
  2003年   105篇
  2002年   85篇
  2001年   72篇
  2000年   74篇
  1999年   65篇
  1998年   23篇
  1997年   33篇
  1996年   29篇
  1995年   21篇
  1994年   23篇
  1992年   43篇
  1991年   48篇
  1990年   47篇
  1989年   32篇
  1988年   45篇
  1987年   45篇
  1986年   45篇
  1985年   47篇
  1984年   31篇
  1983年   27篇
  1982年   23篇
  1979年   28篇
  1978年   27篇
  1977年   19篇
  1976年   23篇
  1974年   26篇
  1973年   20篇
  1972年   20篇
  1971年   19篇
  1970年   19篇
  1969年   26篇
  1968年   24篇
  1966年   30篇
排序方式: 共有2807条查询结果,搜索用时 0 毫秒
101.
102.
BACKGROUND: The PI3K/AKT/mTOR pathway is central to prostate cancer progression. A preliminary investigation of immuno-histochemical expression of mammalian target of rapamycin (mTOR) pathway markers was undertaken to identify patterns of expression in prostate tissue. METHODS: Immunohistochemistry was performed on a custom-made prostate tissue array. Mean long scores and variability of long scores for each marker were recorded for normal lumenal cells, prostate intraepithelial neoplasia (PIN), and cancer. RESULTS: Expression of PTEN decreased and mTOR signaling pathway markers increased in PIN and in cancer as compared to normal cells in the majority of samples. Overexpression of 4E-BP1 and p-4E-BP1 was observed in PIN and cancer. However, in cancer, the overexpression of 4E-BP1 was significantly higher than with any other marker. DISCUSSION: Results suggest that 4E-BP1 overexpression is strongly associated with prostate cancer, especially when combined with PTEN and mTOR expression data. Hierarchical clustering analysis utilizing PTEN, mTOR, and 4E-BP1 separated normal from cancer cell populations in most cases.  相似文献   
103.
In the management of children with acute lymphoblastic leukemia, L-asparaginase has become established as an effective drug in the usual multi-agent therapy; and the significance of pancreatitis as a complication of this drug is well recognized. Less well appreciated, however, is the progression of such pancreatitis in some patients to pseudocyst formation and the possible necessity for surgical management. Two adolescent girls who developed pancreatic pseudocysts while being treated with L-asparaginase are described in this report. Both were being treated for acute lymphoblastic leukemia for periods of 18 and 4 months, respectively, prior to the onset of pancreatitis. Both were in remission of their leukemic disease when typical clinical and laboratory manifestations of acute pancreatitis developed. In one girl, a pancreatic pseudocyst became apparent 2 weeks following the diagnosis of acute pancreatitis and in the other girl, this complication developed over a period of 8 weeks. The usual nonsurgical management of pancreatitis over protracted periods of time was ineffective in the treatment of the pseudocysts. Surgical drainage (internal in one and external in the other) was successful in both in eradicating the pseudocyst, and in neither did further evidence of pancreatic disease subsequently occur. In both resumption of chemotherapy, omitting L-asparaginase, was well tolerated. One has been in remission of leukemia and in good health for a 3-year period of follow-up observation, while the other subsequently had a relapse of leukemia and died 18 months following the onset of pancreatitis.  相似文献   
104.
105.
Idiopathic orbital inflammation (IOI) is defined as a benign non-infective clinical syndrome characterized by features of non-specific inflammation of the orbit without identifiable local or systemic causes. This can be called orbital myositis if the inflammation is predominantly in the orbital muscles. It is a diagnosis of exclusion based on clinical, radiological, and if necessary, histological findings. The most commons symptoms are swelling, ptosis, proptosis and painful eye movements. To our knowledge, this patient is the first with IOI to demonstrate relapsing flitting bilateral involvement of several individual extra-ocular muscles.  相似文献   
106.
Objective: To determine the SNOT 22 score in a normal population. Study design: Analysis of SNOT 22 scores participants with no sinonasal disease. Setting: Bath, UK. Participants: 116 participants from a local hospital and tennis club. Results: Results were obtained from 54 men and 62 women with a mean age of 40 (range 19–75). SNOT score ranged from 0–50 with a mean score of 9.3 (95% confidence interval range of 7.5–11.1). The modal score was 0 and the median score 7 (95% confidence interval range of 5–8). Conclusion: Due to the scewed nature of the data, the median score (7) is taken as the normal SNOT 22 score. We recommend that in an clincial situation a SNOT 22 score of 7 be used a a guide for “normal”, and that care should be taken when suggesting treatment on patients with a score below this level.  相似文献   
107.
We report a prospective study of clinical observed performance evaluation (COPE) for 197 medical students in the pre-qualification year of clinical education. Psychometric quality was the main endpoint. Students were assessed in groups of 5 in 40-min patient encounters, with each student the focus of evaluation for 8 min. Each student had a series of assessments in a 25-week teaching programme. Over time, several clinicians from a pool of 16 surgical consultants and registrars evaluated each student by direct observation. A structured rating form was used for assessment data. Variance component analysis (VCA), internal consistency and inter-rater agreement were used to estimate reliability. The predictive and convergent validity of COPE in relation to summative OSCE, long case, and overall final examination was estimated. Median number of COPE assessments per student was 7. Generalisability of a mean score over 7 COPE assessments was 0.66, equal to that of an 8 × 7.5 min station final OSCE. Internal consistency was 0.88–0.97 and inter-rater agreement 0.82. Significant correlations were observed with OSCE performance (R = 0.55 disattenuated) and long case (R = 0.47 disattenuated). Convergent validity was 0.81 by VCA. Overall final examination performance was linearly related to mean COPE score with standard error 3.7%. COPE permitted efficient serial assessment of a large cohort of final year students in a real world setting. Its psychometric quality compared well with conventional assessments and with other direct observation instruments as reported in the literature. Effect on learning, and translation to clinical care, are directions for future research.  相似文献   
108.
Peshin  R.  O&#;Neill  L.  Browne  P.  O&#;Connell  P.  Kearns  G. 《Clinical rheumatology》2009,28(1):31-34
Interstitial lung disease is an important cause of mortality and morbidity in patients with systemic sclerosis (SSc). There are currently no recommended guidelines for management of these patients. This is probably due to the rarity of this condition, as well as clinical trials with only a small number of cases. There are published case report and case series along with the two main trials, viz. Scleroderma Lung Study and the Fibrosing Alveolitis Study, but again, there is no consensus on treatment protocols. In this report, we present a case of aggressive interstitial lung disease in a patient with SSc, which improved dramatically on treatment with intra-venous cyclophosphamide and high dose prednisolone therapy.  相似文献   
109.
110.
Exposure to cigarette smoke is a major risk factor for sudden infant death syndrome (SIDS). We tested the hypothesis that nicotine increases expression of the nicotinic acetylcholine receptor (nAChR) subunits α7 and β2 in a piglet model. Piglets exposed to 2 mg/kg/day nicotine for 14 days postnatally (n = 14) were compared to non-exposed controls (n = 14), (equal gender proportions). Immunohistochemistry was performed to identify and quantify changes in, α7 and β2 nAChR subunits in 8 nuclei of the medulla at both the rostral and caudal levels. Compared to controls, nicotine exposed piglets had decreased α7 in the rostral dorsal motor nucleus of the vagus (rDMNV) (p = 0.01), and increased β2 in the caudal DMNV (cDMNV) (p = 0.05), caudal nucleus of the spinal trigeminal tract (cNSTT) (p = 0.03) and caudal nucleus of the solitary tract (cNTS) (p = 0.04). Analysis by gender showed that in the control group, compared to males, females had higher β2 in the caudal hypoglossal (cXII) (p < 0.01) and caudal inferior olivary (p = 0.04) nuclei, while in the nicotine group females had higher β2 in the cDMNV (p = 0.02). Compared to control males, nicotine exposed males had lower β2 in the cXII (p < 0.01). Overall, changes in α7 were specific to nicotine exposure with no gender differentiation. Changes in β2 were more widespread but showed gender-specific effects. These findings provide evidence that early postnatal exposure to nicotine significantly affects nAChR subunit expressions in the developing brainstem.  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