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   1496篇
  免费   87篇
  国内免费   24篇
耳鼻咽喉   1篇
儿科学   37篇
妇产科学   21篇
基础医学   224篇
口腔科学   41篇
临床医学   161篇
内科学   421篇
皮肤病学   28篇
神经病学   97篇
特种医学   27篇
外科学   198篇
综合类   10篇
预防医学   93篇
眼科学   18篇
药学   107篇
中国医学   1篇
肿瘤学   122篇
  2023年   7篇
  2022年   18篇
  2021年   26篇
  2020年   41篇
  2019年   19篇
  2018年   32篇
  2017年   23篇
  2016年   33篇
  2015年   27篇
  2014年   54篇
  2013年   58篇
  2012年   89篇
  2011年   105篇
  2010年   40篇
  2009年   45篇
  2008年   68篇
  2007年   85篇
  2006年   79篇
  2005年   57篇
  2004年   56篇
  2003年   60篇
  2002年   57篇
  2001年   49篇
  2000年   44篇
  1999年   36篇
  1998年   20篇
  1997年   23篇
  1996年   22篇
  1995年   15篇
  1994年   19篇
  1993年   16篇
  1992年   45篇
  1991年   25篇
  1990年   24篇
  1989年   18篇
  1988年   24篇
  1987年   21篇
  1986年   17篇
  1985年   20篇
  1984年   15篇
  1983年   9篇
  1981年   4篇
  1979年   5篇
  1977年   7篇
  1976年   7篇
  1974年   5篇
  1973年   4篇
  1972年   6篇
  1967年   4篇
  1966年   5篇
排序方式: 共有1607条查询结果,搜索用时 15 毫秒
31.
The combined effect of Peroxisome proliferator-activated receptor gamma (PPARG) Pro/Ala and interleukin-6 G174C gene variants, was evaluated in 429 Caucasian subjects in order to determine whether subjects carrying both variants were at different risk for obesity. In particular, the combined contribution of these two variants (both independent and interaction effects) to the total variation of obesity-related factors was estimated. All subjects were genotyped for codon 12 Pro/Ala locus variability and for the interleukin-6-174 C/G promoter polymorphism. Subjects with the Ala variant had significantly lower BMI, insulin resistance, triglyceride levels than those without. Furthermore, subjects with Ala variant had significantly lower IL-6 levels (0.88 +/- 0.9 vs 1.61 +/- 2.25 pg/ml; p = 0.041). In contrast, the IL6-C variant was significantly associated with lower plasma IL-6 and with lower total cholesterol levels but was not significantly associated with any other obesity risk factors. Indeed, subjects carrying both PPARG and IL-6 gene variants, had a clearly more favourable profile of obesity related risk factors than subjects with one variant, having Ala+/C+ carriers lower BMI (22.8 +/- 2.3 vs 24.14 +/- 1.9; f = 5.31; p < 0.005), insulin resistance (1.49 +/- 0.70 vs 2.13 +/- 0.92; f = 4.342; p = 0.038) and triglyceride levels (79.15 +/- 32.9 vs 98 +/- 6.73 mg/dl; f = 3.120; p < 0.005). These findings suggest that the effect of the two genetic variants on 'obesity related' factors is additive.  相似文献   
32.
The European Working Group on Clinical Cell Analysis (EWGCCA) has, in preparation for a multicentre peripheral blood stem cell clinical trial, developed a single-platform flow cytometric protocol for the enumeration of CD34+ stem cells. Using this protocol, stabilized blood and targeted training, the EWGCCA have attempted to standardize CD34+ stem cell enumeration across 24 clinical sites. Results were directly compared with participants in the UK National External Quality Assessment Scheme (NEQAS) for CD34+ Stem Cell Quantification that analysed the same specimens using non-standardized methods. Two bead-counting systems, Flow-Count and TruCount, were also evaluated by the EWGCCA participants during trials 2 and 3. Using Flow-Count, the intralaboratory coefficient of variation (CV) was 相似文献   
33.
Di Napoli M  Papa F 《Hypertension》2003,42(6):1117-1123
Among patients with acute stroke, high blood pressure (BP) and higher levels of circulating C-reactive protein (CRP) at the entry are often associated with poor outcome, although the reason is unclear. If the link between BP and stroke outcome is indeed mediated by inflammatory response, one would expect to see positive associations between BP and CRP. In a prospective observational stroke data bank involving 535 first-ever ischemic stroke patients, we studied the association between BP and baseline concentrations of CRP within 24 hours after stroke onset. The association between BP components and the odds of having an elevated CRP level (> or =1.5 mg/dL) was assessed by logistic regression analysis. An increase in systolic BP (SBP), diastolic BP (DBP), mean arterial pressure (MAP), or pulse pressure (PP) was significantly associated with an increase in the odds of having an elevated CRP level, independent of other associated study factors. For each 10 mm Hg increase in SBP, DBP, MAP, or PP, the odds of having a high CRP level increased by 72% (P<0.0001), 10% (P<0.0001), 21% (P<0.0001), and 10% (P<0.0001), respectively. When the same model was rerun, adjusting for all considered BP components, only SBP significantly increased the odds of an elevated CRP level by 77% (P<0.0001). Increased SBP was significantly associated with elevated levels of circulating CRP in ischemic stroke patients. These findings support a possible role of acute hypertension after stroke as an inflammatory stimulus contributing to ischemic brain inflammation.  相似文献   
34.
Autoimmune hemolytic anemia followed by myelomonocytic leukemia.   总被引:1,自引:0,他引:1  
  相似文献   
35.
To determine physician characteristics associated with the use of bone densitometry (BD), we conducted a cross-sectional survey of primary care practitioners in an urban community hospital. Participants were internists, geriatricians, and family practitioners. Seventy-two percent of the physicians never used BD. There was no association between physician or practice characteristics and BD use. Bone densitometry users were more likely than nonusers to treat their patients with osteoporosis or at risk of developing it. Self-reported barriers to use included cost, unfamiliarity with guidelines, uncertainty with clinical applicability, minimal impact on treatment decisions, and availability. In conclusion, although it has been shown that osteoporotic women who are aware of their BD results are more likely to accept treatment, further attention should be paid to primary care practitioners' attitudes, knowledge, and behavior regarding the use of BD in the management of osteoporosis.
KEY WORDS: bone densitometry; osteoporosis; physician knowledge; attitudes; behaviors.  相似文献   
36.
Dobrava-Belgrade virus (DOBV) is a human pathogen that has evolved in, and is hosted by, mice of several species of the genus Apodemus. We propose a subdivision of the species Dobrava-Belgrade virus into four related genotypes – Dobrava, Kurkino, Saaremaa, and Sochi – that show characteristic differences in their phylogeny, specific host reservoirs, geographical distribution, and pathogenicity for humans.  相似文献   
37.
Epidemics of West Nile virus (WNV) occurred for two consecutive years in Greece (in 2010 and 2011). A total of 16,116 adult Culex pipiens mosquitoes collected in two peripheries, Central Macedonia and Thessaly, were tested for WNV infection. WNV lineage 2 was detected in 6/296 mosquito pools, three in each year. The H249P substitution in the NS3 protein, previously associated with increased pathogenicity and thermotolerance, was detected in all six WNV-positive mosquito pools. When 21 individual C. pipiens mosquitoes were tested for the locus CQ11 to distinguish between the two C. pipiens forms, pipiens and molestus, 71.4 % were identified as pipiens, 4.7 % as molestus, and 19 % as hybrid pipiens/molestus, giving the first evidence that both C. pipiens biotypes are present in Greece, with a significant proportion being hybrids. The exact role of the C. pipiens forms and hybrids in the WNV epidemiology, in combination or not with the H249P substitution in the virus genome, remains to be elucidated.  相似文献   
38.
39.
Familial dilated cardiomyopathy (DCM) is a heterogeneous disease; although 30 disease genes have been discovered, they explain only no more than half of all cases; in addition, the causes of intra-familial variability in DCM have remained largely unknown. In this study, we exploited the use of whole-exome sequencing (WES) to investigate the causes of clinical variability in an extended family with 14 affected subjects, four of whom showed particular severe manifestations of cardiomyopathy requiring heart transplantation in early adulthood. This analysis, followed by confirmative conventional sequencing, identified the mutation p.K219T in the lamin A/C gene in all 14 affected patients. An additional variant in the gene for titin, p.L4855F, was identified in the severely affected patients. The age for heart transplantation was substantially less for LMNA:p.K219T/TTN:p.L4855F double heterozygotes than that for LMNA:p.K219T single heterozygotes. Myocardial specimens of doubly heterozygote individuals showed increased nuclear length, sarcomeric disorganization, and myonuclear clustering compared with samples from single heterozygotes. In conclusion, our results show that WES can be used for the identification of causal and modifier variants in families with variable manifestations of DCM. In addition, they not only indicate that LMNA and TTN mutational status may be useful in this family for risk stratification in individuals at risk for DCM but also suggest titin as a modifier for DCM.  相似文献   
40.

Background:

Oesophageal atresia is a neonatal emergency surgery whose prognosis has improved significantly in industrialised countries in recent decades. In sub-Saharan Africa, this malformation is still responsible for a high morbidity and mortality. The objective of this study was to analyse the diagnostic difficulties and its impact on the prognosis of this malformation in our work environment.

Patients and Methods:

We conducted a retrospective study over 4 years on 49 patients diagnosed with esophageal atresia in the 2 Paediatric Surgery Departments in Dakar.

Results:

The average age was 4 days (0-10 days), 50% of them had a severe pneumonopathy. The average time of surgical management was 27 h (6-96 h). In the series, we noted 10 preoperative deaths. The average age at surgery was 5.7 days with a range of 1-18 days. The surgery mortality rate is 28 patients (72%) including 4 late deaths.

Conclusion:

The causes of death were mainly sepsis, cardiac decompensation and anastomotic leaks.Key words: Esophageal atresia, Diagnosis, Prognosis, Sub-Saharan Africa  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