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   679篇
  免费   61篇
  国内免费   2篇
耳鼻咽喉   9篇
儿科学   27篇
妇产科学   26篇
基础医学   102篇
口腔科学   8篇
临床医学   117篇
内科学   133篇
皮肤病学   7篇
神经病学   55篇
特种医学   13篇
外科学   65篇
综合类   5篇
预防医学   73篇
眼科学   5篇
药学   54篇
中国医学   7篇
肿瘤学   36篇
  2023年   12篇
  2022年   30篇
  2021年   41篇
  2020年   19篇
  2019年   35篇
  2018年   44篇
  2017年   27篇
  2016年   25篇
  2015年   22篇
  2014年   33篇
  2013年   43篇
  2012年   66篇
  2011年   62篇
  2010年   28篇
  2009年   24篇
  2008年   52篇
  2007年   28篇
  2006年   40篇
  2005年   22篇
  2004年   22篇
  2003年   27篇
  2002年   20篇
  2001年   2篇
  1999年   1篇
  1998年   1篇
  1997年   5篇
  1996年   1篇
  1995年   2篇
  1994年   2篇
  1992年   2篇
  1988年   1篇
  1985年   1篇
  1983年   1篇
  1979年   1篇
排序方式: 共有742条查询结果,搜索用时 15 毫秒
91.
The authors report the case of a patient who developed small bowel obstruction after laparoscopic gastric bypass. Imaging revealed an obstruction at the enteroenterostomy resulting in dilation of the bypassed stomach and proximal small bowel. The bypassed stomach was percutaneously drained using CT guidance, leading to resolution of the small bowel obstruction. Biliopancreatic limb obstructions can be successfully treated non-operatively after gastric bypass.  相似文献   
92.
Purpose: To evaluate the safety and feasibility of self‐expandable stents (OptiMed) for treatment of abdominal aortic stenosis in the situations in which the aortic stenosis locates near the origin of celiac, superior mesenteric, renal and inferior mesenteric arteries. Methods: Five consecutive patients scheduled for endovascular treatment of abdominal aortic stenosis by self‐expandable nitinol stent (Sinus‐Aorta/OptiMed) implantation. The diameter of the stent was chosen as 10–30% more than that of the normal portion of the aorta above the stenosis. Long stents of 60 mm or longer were chosen. After stent deployment, balloon postdilation was performed with a balloon in patients with residual gradient > 5 mm Hg. Results: All patients were successfully treated with the OptiMed stents. The balloon predilation was performed in one patient due to severe stenosis. The mean diameter and length of the stents deployed were 20.4 ± 2.9 (range, 16–24 mm) and 64 ± 8.9 (range, 60–80 mm), respectively. The balloon postdilation was performed in all cases. The mean diameter of the balloons was 13.6 ± 1.5 (range, 12–15 mm). The mean diameter of stenosis increased from 4.8 ± 1.9 to 14.4 ± 1.8 mm after stent placement. The mean peak systolic gradient decreased from 46.8 ± 31.5 mm Hg to 0.8 ± 1.8 mm Hg. During follow‐up (22.8 ± 14.3 months), none of the patients had restenosis within the stent, occlusion of any branches of the aorta, or other related complications. Conclusions: In our small series, we observed that abdominal aortic stenosis can be successfully and effectively treated with OptiMed stents in the situations in which the stenotic segment is located next to the origins of the main visceral branches of abdominal aorta. © 2009 Wiley‐Liss, Inc.  相似文献   
93.
Having identified renin in cardiac mast cells, we assessed whether its release leads to cardiac dysfunction. In Langendorff-perfused guinea pig hearts, mast cell degranulation with compound 48/80 released Ang I-forming activity. This activity was blocked by the selective renin inhibitor BILA2157, indicating that renin was responsible for Ang I formation. Local generation of cardiac Ang II from mast cell-derived renin also elicited norepinephrine release from isolated sympathetic nerve terminals. This action was mediated by Ang II-type 1 (AT1) receptors. In 2 models of ischemia/reperfusion using Langendorff-perfused guinea pig and mouse hearts, a significant coronary spillover of renin and norepinephrine was observed. In both models, this was accompanied by ventricular fibrillation. Mast cell stabilization with cromolyn or lodoxamide markedly reduced active renin overflow and attenuated both norepinephrine release and arrhythmias. Similar cardioprotection was observed in guinea pig hearts treated with BILA2157 or the AT1 receptor antagonist EXP3174. Renin overflow and arrhythmias in ischemia/reperfusion were much less prominent in hearts of mast cell-deficient mice than in control hearts. Thus, mast cell-derived renin is pivotal for activating a cardiac renin-angiotensin system leading to excessive norepinephrine release in ischemia/reperfusion. Mast cell-derived renin may be a useful therapeutic target for hyperadrenergic dysfunctions, such as arrhythmias, sudden cardiac death, myocardial ischemia, and congestive heart failure.  相似文献   
94.
Chronic liver disease has a significant impact on the survival of renal transplant recipients with an incidence rate of 4-38%. Approximately, 8-28% of renal transplant recipients die due to chronic liver disease. Hepatitis C seems to be the leading cause of chronic liver disease in kidney recipients. Hepatitis C virus (HCV) infection has a wide range of prevalence (2.6-66%) among renal transplant recipients living in different countries with great genotype diversity in different parts of the world. Nowadays, antiviral drugs are used for the management of hepatitis C. Because of graft-threatening effects of some antiviral drugs used in HCV-infected renal transplant recipients, we specifically focused on HCV treatment after renal transplantation. Treatment of post-renal transplantation chronic liver disease with INF and ribavirin remains controversial. Anecdotal reports on post-renal transplantation hepatitis C demonstrate encouraging findings. This review summarises the most current information on diagnosis, treatment, prognosis, complications as well as the new aspects of treatment in HCV-infected renal transplant recipients. HCV belongs to the family of Flaviviridae, genus Hepacivirus.  相似文献   
95.
Novel antileishmanials are urgently required to overcome emergence of drug resistance, cytotoxic effects, and difficulties in oral delivery. Toward this, we investigated a series of novel 4-aminoquinaldine derivatives, a new class of molecules, as potential antileishmanials. 4-Aminoquinaldine derivatives presented inhibitory effects on L. donovani promastigotes and amastigotes (50% inhibitory concentration range, 0.94 to 127 μM). Of these, PP-9 and PP-10 were the most effective in vitro and demonstrated strong efficacies in vivo through the intraperitoneal route. They were also found to be effective against both sodium antimony gluconate-sensitive and -resistant Leishmania donovani strains in BALB/c mice when treated orally, resulting in more than 95% protection. Investigation of their mode of action revealed that killing by PP-10 involved moderate inhibition of dihydrofolate reductase and elicitation of the apoptotic cascade. Our studies implicate that PP-10 augments reactive oxygen species generation, evidenced from decreased glutathione levels and increased lipid peroxidation. Subsequent disruption of Leishmania promastigote mitochondrial membrane potential and activation of cytosolic proteases initiated the apoptotic pathway, resulting in DNA fragmentation and parasite death. Our results demonstrate that PP-9 and PP-10 are promising lead compounds with the potential for treating visceral leishmaniasis (VL) through the oral route.  相似文献   
96.
Despite different studies on the reliability of pelvic floor muscle assessment, there is still no general consensus on the most valid and reliable method. The purpose of this study was to investigate the intra-rater (within-day and between-days) reliability of perineometer in the assessment of pelvic floor muscle strength and endurance. Following ethical approval, 15 healthy women aged from 22 to 50-years old, with no history of low back pain were recruited. The Peritron perineometer instrument was used to measure pelvic floor muscle strength and endurance. Two measurements were taken on the same day with an hour interval to assess within-day reliability and the third measurement was taken five days later to determine between-days reliability. Intraclass Correlation Coefficients (ICCs) and the level of agreement between measurements were used for data analysis. The high ICC values (0.95 for strength and 0.94 for endurance) and high level of agreement between measurements indicated high within-day reliability for pelvic floor muscle strength and endurance. The perineometer was also shown to be reliable for between-days measurements with high ICC (0.88 for strength and 0.83 for endurance) and high level of agreement between measurements. The results demonstrated that the perineometer appears to be a highly reliable method of measuring pelvic floor muscle strength and endurance when measurements are taken in healthy subject by the same investigator.  相似文献   
97.
The adipocytokine apelin is a peptide that was isolated from a bovine stomach for the first time. This peptide and its receptor are abundantly expressed in the nervous and cardiovascular systems. According to previous studies, apelin-13 protects cardiomyocytes from ischemic injury as well as apoptosis. In addition, this peptide has a neuroprotective effect on hippocampal and cultured mouse cortical neurons against NMDA receptor-mediated excitotoxicity. The present study was conducted to determine whether apelin-13 provides protection in transient focal cerebral ischemia. Focal ischemia was induced by 60-min middle cerebral artery occlusion (MCAO), followed by 23-h reperfusion. Saline as a vehicle and apelin-13 at doses of 25, 50, and 100 μg were injected intracerebroventriculary (ICV) at the beginning of ischemia. Infarct volume ,brain edema, motor dysfunction, and apoptosis were assessed 24 h after MCAO. Treatment with apelin-13 at doses of 50 and 100 μg ICV markedly reduced total infarct volumes by 45 and 55 %, respectively (P?P?>?0.05). In addition, apelin-13 at doses of 50 and 100 μg reduced brain edema (P?P?P?>?0.05).  相似文献   
98.
99.

Background

Most diseases are thought to arise from interactions between environmental factors and the host genotype. To detect gene–environment interactions in the development of lifestyle-related diseases, and especially cancer, the Japan Multi-institutional Collaborative Cohort (J-MICC) Study was launched in 2005.

Methods

We initiated a cross-sectional study to examine associations of genotypes with lifestyle and clinical factors, as assessed by questionnaires and medical examinations. The 4519 subjects were selected from among participants in the J-MICC Study in 10 areas throughout Japan. In total, 108 polymorphisms were chosen and genotyped using the Invader assay.

Results

The study group comprised 2124 men and 2395 women with a mean age of 55.8 ± 8.9 years (range, 35–69 years) at baseline. Among the 108 polymorphisms examined, 4 were not polymorphic in our study population. Among the remaining 104 polymorphisms, most variations were common (minor allele frequency ≥0.05 for 96 polymorphisms). The allele frequencies in this population were comparable with those in the HapMap-JPT data set for 45 Japanese from Tokyo. Only 5 of 88 polymorphisms showed allele-frequency differences greater than 0.1. Of the 108 polymorphisms, 32 showed a highly significant difference in minor allele frequency among the study areas (P < 0.001).

Conclusions

This comprehensive data collection on lifestyle and clinical factors will be useful for elucidating gene–environment interactions. In addition, it is likely to be an informative reference tool, as free access to genotype data for a large Japanese population is not readily available.Key words: allele frequency, cross-sectional studies, gene–environment interactions, Japan Multi-institutional Collaborative Cohort Study, polymorphism  相似文献   
100.
Today, cardiovascular diseases remain a leading cause of morbidity and mortality worldwide. Endothelial to mesenchymal transition (EndMT) does not only play a major role in the course of development but also contributes to several cardiovascular diseases in adulthood. EndMT is characterized by down-regulation of the endothelial proteins and highly up-regulated fibrotic specific genes and extracellular matrix-forming proteins. EndMT is also a transforming growth factor-β-driven (TGF-β) process in which endothelial cells lose their endothelial characteristics and acquire a mesenchymal phenotype with expression of α-smooth muscle actin (α-SMA), fibroblast-specific protein 1, etc. EndMT is a vital process during cardiac development, thus disrupted EndMT gives rise to the congenital heart diseases, namely septal defects and valve abnormalities. In this review, we have discussed the main signaling pathways and mechanisms participating in the process of EndMT such as TGF-β and Bone morphogenetic protein (BMP), Wnt#, and Notch signaling pathway and also studied the role of EndMT in physiological cardiovascular development and pathological conditions including myocardial infarction, pulmonary arterial hypertension, congenital heart defects, cardiac fibrosis, and atherosclerosis. As a perspective view, having a clear understanding of involving cellular and molecular mechanisms in EndMT and conducting Randomized controlled trials (RCTs) with a large number of samples for involving pharmacological agents may guide us into novel therapeutic approaches of congenital disorders and heart diseases.  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