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   1404篇
  免费   55篇
  国内免费   12篇
耳鼻咽喉   27篇
儿科学   52篇
妇产科学   46篇
基础医学   88篇
口腔科学   35篇
临床医学   152篇
内科学   329篇
皮肤病学   17篇
神经病学   110篇
特种医学   40篇
外国民族医学   1篇
外科学   270篇
综合类   34篇
一般理论   1篇
预防医学   40篇
眼科学   40篇
药学   107篇
中国医学   5篇
肿瘤学   77篇
  2024年   2篇
  2023年   17篇
  2022年   50篇
  2021年   81篇
  2020年   47篇
  2019年   65篇
  2018年   59篇
  2017年   29篇
  2016年   32篇
  2015年   43篇
  2014年   74篇
  2013年   95篇
  2012年   111篇
  2011年   147篇
  2010年   82篇
  2009年   62篇
  2008年   103篇
  2007年   91篇
  2006年   69篇
  2005年   63篇
  2004年   58篇
  2003年   38篇
  2002年   28篇
  2001年   4篇
  2000年   3篇
  1999年   2篇
  1998年   4篇
  1997年   1篇
  1996年   2篇
  1995年   2篇
  1994年   1篇
  1993年   1篇
  1992年   1篇
  1991年   1篇
  1989年   1篇
  1986年   1篇
  1982年   1篇
排序方式: 共有1471条查询结果,搜索用时 15 毫秒
81.
82.

Background

Clear cell renal cell carcinoma (ccRCC) is known to occur across the adult lifetime traversing the spectrum of age-related organismal changes. Little is known as to how the aging process may affect the course of renal cell carcinoma (RCC) and the repertoire of genes involved.

Methods

Using The Cancer Genome Atlas (n?=?436) and Cancer Genomics of the Kidney (n?=?89) datasets, we applied regression analysis to examine associations between patient age and gene expression profiles in ccRCC tumors and normal kidney tissues. Pathway enrichment analysis was performed to identify cellular process that is affected by aging in ccRCC. Moreover, connectivity mapping analysis was used to predict age-dependent response to drug treatments.

Results

Our analysis revealed different age-dependent gene expression spectra in ccRCC and normal kidney tissues. These findings were significant and independently reproducible in both datasets examined. Age up-regulated genes, showing higher expression in older patients, were significantly enriched (false discovery rate <0.05) in normal tissues for pathways associated with immune response and extracellular matrix organization, whereas age up-regulated genes in tumors were enriched for metabolism and oxidation pathways. Strikingly, age down-regulated genes in normal cells were also enriched for metabolism and oxidation, while those in tumors were enriched for extracellular matrix organization. Further in silico analysis of potential drug targets predicted preferential efficacy of Phosphoinositide 3-kinase inhibitor or immunotherapy in association with age.

Conclusion

We report on previously unrecognized associations between age and molecular underpinnings of RCC, including age-associated expression of genes implicated in RCC development or treatment.  相似文献   
83.

Aim

To compare the value of Procalcitonin (PCT) as a marker of surgical site infection to other inflammatory markers, including C-Reactive Protein (CRP), White Cell Count (WCC) and Erythrocyte Sedimentation Rate (ESR) in patients undergoing a number of spinal procedures. This study also aims to describe the biokinetic profile of the above-named markers in patients developing surgical site infection and those remaining infection-free post-operatively.

Methods

200 patients undergoing four routine elective spinal procedures were included for analysis. All patients had blood specimens taken at baseline, day 1, 2, 3, 4 and 5 post-operatively for analysis of PCT, CRP, ESR and WCC levels. All patients were monitored for early surgical site infection. Patients with other sources of infection in the early postoperative period were excluded.

Results

Procalcitonin was the most sensitive and specific marker for the detection of surgical site infection in the immediate post-operative period with sensitivity and specificity of 100% and 95.2% respectively. Although Procalcitonin is an inflammatory marker, extent of surgical physiological insult did not alter its biokinetics as opposed to the other inflammatory markers making it a valuable marker of infection.

Conclusion

Procalcitonin was found to be superior to the other inflammatory markers investigated in this study as a marker for early surgical site infection in patients undergoing spinal surgery.  相似文献   
84.
85.
We describe a case of pulmonary thromboembolism in a 61-year-old woman with beta-thalassemia intermedia and no other risk factors for thrombosis. Thromboembolism was documented by perfusion lung scan. We review the literature on this uncommon complication of thalassemia intermedia and discuss the pathogenesis and treatment options. A significant relationship between pulmonary thromboembolism and pulmonary hypertension in these patients was noted.  相似文献   
86.
PURPOSE: To investigate the ocular penetration of acyclovir and its prodrugs following systemic administration and to elucidate the mechanism of penetration. METHODS: Hydrophilic peptide prodrugs of acyclovir were infused intravenously in New Zealand albino rabbits over 45 min at a dose equivalent to 30 mmoles/kg acyclovir. Aqueous and vitreous humor samples were obtained utilizing ocular microdialysis and blood samples were obtained from the mid ear vein using a cannula. RESULTS: The plasma bioavailability for acyclovir, valacyclovir and val-valacyclovir were similar with area under curve values being 896.24 (+/-143.58), 776.54 (+/-197.52), 824.69 (+/-217.43) min x micromoles/L respectively. Anterior segment area under curve values were 53.70 (+/-35.58), 139.85 (+/-9.43) and 291.05 (+/-88.13) min x micromoles/L respectively while the mean residence time values were 46.47 (+/-24.94), 76.30 (+/-7.24) and 188.39 (+/-80.73) min respectively. Vitreous levels of the prodrugs were not measurable. CONCLUSIONS: The valine and valine-valine ester prodrugs of ACV penetrated the anterior segment of the eye much better than acyclovir alone, probably via a carrier mediated transport mechanism.  相似文献   
87.
There are two main ways in which physicians will be urged to improve the outcome for their patients suffering from rheumatic diseases in the coming era, these are, early diagnosis and timely effective therapy. Current reserch suggests that in rheumatoid arthritis joint damage occurs early, often within the first 2 years and even in the absence of associating severe symptoms, is a call for action for primary care physicians as well as rheumatologists. Similarly in SLE patients, sometimes the treatments are ineffective or too toxic with sepsis or opportunistic infections often limiting their use or resulting in the death of the patient. As primary care physicians are the clinicians most frequently visited by patients with initial symptoms of the disease, they first need to learn when to suspect it as well as its complications, and when to refer the patient appropriately. Rheumatologists need to determine when and how to prescribe the most appropriate treatment, as well as how to incorporate the new drugs which are emerging on the scene. At the same time, earlier initiation of combination therapy with the disease modifying anti-rheumatic therapy holds an area of continued exploration. This new information has modified our approach to patients' management. The age of "wait and see" is over.  相似文献   
88.
Khazaal Y  Zullino DF 《Swiss medical weekly》2003,133(27-28):398-399
A high variety of factors have been implicated in the emergence of depersonalisation and derealisation episodes, including different drugs. A case abruptly induced by two applications of reboxetine, a selective and specific norepinephrine reuptake inhibitor, is reported occurring in a 50-year-old woman treated for a major depressive episode. The episode rapidly remitted after discontinuation of reboxetine. Previous data having indicated a role of the serotonin system in the pathophysiology of the phenomenon, a noradrenaline induced serotonin liberation of Raphe neurons is suggested as possible underlying mechanism.  相似文献   
89.
90.
The neuronal ceroid-lipofuscinoses (NCL) are the most common group of progressive neurodegenerative diseases in children, with an incidence as high as one in 12,500 live births. The main features of this disease are failure of psychomotor development, impaired vision, seizures, and premature death. Many biochemical and physiological studies have been initiated to determine the cellular defect underlying the disease, although only a few traits have been truly associated with the disorders. One of the paradox's of the NCL-diseases is the characteristic accumulation of autofluorescent hydrophobic material in the lysosomes of neurons and other cell types. However, the accumulation of this lysosomal storage material, which no doubt contributes to the neurologic disease, does not apparently lead to disease outside the CNS, and how these cellular alterations relate to the neurodegeneration in NCLs is unknown. Mutations have been identified in six distinct genes/proteins, namely CLN1, which encodes PPT1, a protein thiolesterase; CLN2, which encodes TPP1, a serine protease; and CLN3, CLN5, CLN6, and CLN8, which encode novel transmembrane proteins. Mutation in any one of these CLN-proteins results in a distinct type of NCL-disease. However, there are many shared similarities in the pathology of these diseases. The most obvious connection between PPT1, TPP1, CLN3, CLN5, CLN6, and CLN8 is their subcellular localization. To date, three of the four proteins whose subcellular localization has been confirmed, namely PPT1, TPP1, and CLN3, reside in the lysosome. We review the function of the CLN-proteins and discuss the possibility that a disruption in a common biological process leads to an NCL-disease.  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