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   1523篇
  免费   42篇
耳鼻咽喉   3篇
儿科学   76篇
妇产科学   29篇
基础医学   184篇
口腔科学   21篇
临床医学   97篇
内科学   330篇
皮肤病学   81篇
神经病学   99篇
特种医学   89篇
外科学   231篇
综合类   2篇
一般理论   1篇
预防医学   50篇
眼科学   37篇
药学   90篇
中国医学   2篇
肿瘤学   143篇
  2021年   9篇
  2020年   8篇
  2018年   9篇
  2015年   14篇
  2014年   18篇
  2013年   24篇
  2012年   86篇
  2011年   106篇
  2010年   37篇
  2009年   41篇
  2008年   121篇
  2007年   134篇
  2006年   111篇
  2005年   103篇
  2004年   88篇
  2003年   88篇
  2002年   50篇
  2001年   14篇
  2000年   31篇
  1999年   22篇
  1998年   11篇
  1997年   10篇
  1996年   18篇
  1995年   6篇
  1994年   7篇
  1993年   9篇
  1992年   13篇
  1991年   19篇
  1990年   12篇
  1989年   17篇
  1988年   25篇
  1987年   17篇
  1986年   15篇
  1985年   18篇
  1984年   12篇
  1983年   19篇
  1982年   6篇
  1981年   8篇
  1980年   10篇
  1979年   15篇
  1978年   10篇
  1977年   13篇
  1975年   9篇
  1974年   22篇
  1973年   23篇
  1972年   24篇
  1971年   15篇
  1970年   13篇
  1969年   8篇
  1968年   11篇
排序方式: 共有1565条查询结果,搜索用时 281 毫秒
51.
52.
OBJECTIVES: Given that obsessive-compulsive disorder (OCD) and schizophrenia may share clinical symptoms as well as functional brain abnormalities, this study was designed to clarify common and different morphological abnormalities in OCD and schizophrenia. METHODS: Volumes of the hippocampus, the amygdala, and the thalamus were measured in three age and sex matched groups of 22 patients with OCD, 22 patients with schizophrenia, and 22 normal subjects using three dimensional magnetic resonance imaging. Volume tracing was performed manually on serial coronal slices with the references of sagittal or axial planes using internal landmarks. RESULTS: Hippocampal volume was bilaterally reduced in both OCD and schizophrenic patients versus the normal controls. Left amygdala volume was significantly enlarged in patients with OCD but not in patients with schizophrenia versus the normal controls. The thalamus did not show any volumetric group differences. CONCLUSIONS: Non-specific hippocampal reduction in both the OCD and schizophrenic groups is likely to link to a clinical overlap between the two illnesses, whereas the left amygdala enlargement observed only in the OCD patients seems to be suggestive of a unique role for the amygdala in the pathophysiology of OCD.  相似文献   
53.
54.
The protein flotillin-1 is associated with the 'lipid rafts', that is, membrane microdomains that are enriched in cholesterol and sphingolipids. We compared flotillin-1 immunoreactivity in the hippocampus, amygdala and isocortex (Brodmann area 22) of six controls and 13 Alzheimer's disease (AD) cases (10 sporadic and three familial). A diffuse labelling of the neuropil was observed in most of the samples. The intensity of this labelling was not correlated with the density of neurofibrillary tangles (NFT) or of senile plaques. Some neuronal cell bodies were diffusely labelled in patients as in controls. Immunostained granular bodies were found in the cell body of a few neurones. The density of neuronal profiles containing large granular bodies (diameter > or =2 microm) was significantly higher in AD cases and was correlated with the density of NFTs in the three regions that were studied. Sections stained by double immunofluorescence methods and examined with confocal microscopy suggested that flotillin-1 accumulated most often in tangle-bearing neurones (76% of flotillin-1-positive neurones contained a NFT). Flotillin-1 immunoreactivity, even when found in a tangle-bearing neurone, was not colocalized with tau protein indicating that the two proteins were not in close contact and probably in different subcellular compartments. Flotillin-1-positive granular bodies were also found in neurones containing Pin1-positive vesicles but were not colocalized with them. Flotillin-1 immunoreactivity was colocalized with cathepsin D, a lysosomal marker. These data indicate that flotillin-1, a marker of rafts, accumulates in lysosomes of tangle-bearing neurones in the course of AD.  相似文献   
55.
Background Hailey‐Hailey disease (HHD) or familial benign chronic pemphigus is a rare autosomal dominant inherited skin disorder, characterized by flaccid vesicles and erosions on the intertriginous areas. Current treatments are not particularly effective. We report 6 cases dramatically improving with doxycycline. Case reports 6 patients, aged from 33 to 77 years old, presented with a variable 4 to 40 year history of severe treatment‐resistant HHD. All 6 patients were then treated successfully with doxycycline 100 mg per day for at least 3 months. Discussion An improvement was observed in all 6 patients from 1 week to 3 months after the beginning of treatment. Relapses were observed after various periods. Maintenance half‐dose therapy seemed to be beneficial in patients experiencing recurrence. Only one patient developed gastro‐intestinal intolerance. No other side effects were reported. Currently, 2 patients have improved and present a decreased number of exacerbations, 2 others are in complete remission after more than 5 years of follow‐up. Treatment efficiency is difficult to evaluate in HHD as it is a rare condition. No controlled studies have been published. Local treatments may improve inflammation but do not treat the underlying cause, targeted systemic therapies exist but there is little evidence supporting their use, physical treatments are cumbersome. Besides their antibiotic potential, tetracycline antibiotics also have anti‐inflammatory properties and anticollagenase activity via inhibition of matrix metalloproteinases. Conclusions Doxycycline appears to be an interesting therapeutic option in Hailey‐Hailey disease.  相似文献   
56.
57.
BACKGROUND: Phase III study comparing the effect of oral ibandronate and intravenous zoledronic acid on bone markers. PATIENTS AND METHODS: Breast cancer patients with bone metastases received ibandronate 50 mg/day (n = 137) or zoledronic acid 4 mg every 4 weeks (n = 138) for 12 weeks. The primary end point was mean percentage change in serum levels of cross-linked C-terminal telopeptide of type I collagen (S-CTX) at week 12. Urinary CTX (U-CTX), bone alkaline phosphatase (ALP), amino-terminal procollagen propeptide of type I collagen (PINP) and osteocalcin (OC) were also measured and bone pain and safety assessed. RESULTS: Both bisphosphonates significantly reduced S-CTX (mean ibandronate 76% +/- 29 (SD) versus mean zoledronic acid 73% +/- 47; P < 0.001 for both versus baseline) and U-CTX (ibandronate 78% +/- 50 versus zoledronic acid 86% +/- 17; P < 0.001). The difference in S-CTX between treatments was 0.6% (confidence interval -1.7% to 3.0%), which was within the prespecified noninferiority margin. Bone ALP, PINP and OC decreased by 26%-47% compared with baseline with both bisphosphonates. Compared with zoledronic acid, ibandronate patients reported fewer adverse events overall (65.0% versus 75.9%), and on days 1-3 (8.0% versus 47.5%), including less pyrexia (overall incidence 0% versus 16.8%) and bone pain (5.8% versus 12.4%). CONCLUSIONS: Oral ibandronate was well tolerated and statistically noninferior to zoledronic acid for percentage change in the bone resorption marker, S-CTX.  相似文献   
58.
Prophylactic cranial irradiation (PCI) has become part of the standard treatment in patients with small cell lung cancer (SCLC) in complete remission. Not only does it decrease the risk of brain recurrence by almost 50%, it has a significant positive effect on survival (5.4 percent increase at 3 years). As the prognosis of patients with locally advanced non-small cell lung cancer (NSCLC) has improved with combined modality treatment, brain metastases have also become an important cause of failure (10 to 30%, approaching 50% in certain studies as in SCLC). Survival after treatment of brain metastases is poor and impact on quality of life of patients is important. As in SCLC, 4 randomised evaluating PCI in NSCLC have been carried out in the seventies and early eighties. If 3 out of 4 trials have shown a significant decrease of brain metastases, none of them demonstrated any impact on survival. Thus PCI cannot be recommended as standard treatment in NSCLC, however new trials would be needed.  相似文献   
59.
60.
Phosphoinositide-specific phospholipase C (PLC) is a key enzyme in the regulation of Ca(2+) release from inositol 1,4,5-triphosphate-sensitive stores. U73122 (1-(6-((17beta-3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione) has been extensively used as a pharmacological inhibitor of PLC to elucidate the importance of this enzyme family in signal transduction pathways. U73122 has an electrophilic maleimide group, which readily reacts with nucleophiles such as thiols and amines. In the current study the conjugation of U73122 to common components of cell culture medium, namely l-glutamine, glutathione, and bovine serum albumin (BSA), was demonstrated. The half-life of U73122 on incubation with phosphate-buffered saline (PBS), Hanks' buffered saline solution (with 2 mM glutamine), optimized basal nutrient medium (MCDB131, without BSA), complete medium, Dulbecco's modified Eagle's medium (with 2 mM l-glutamine) was approximately 150, 60, 32, 30, and 18 min, respectively. However, U73122 was not recoverable from medium supplemented with 0.5% BSA. U73122 underwent hydrolysis of the maleimide group when incubated with PBS. Glutamine conjugates of U73122 were identified in cell culture medium. Furthermore, the inhibition of epidermal growth factor-stimulated Ca(2+) release in a human epidermoid carcinoma cell line (A431) by U73122 was substantially reduced by the presence of BSA in a time-dependent manner. In complex cellular assays, the availability of U73122 to inhibit PLC may be limited by its chemical reactivity and lead to the misinterpretation of results in pharmacological assays.  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