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   5648篇
  免费   263篇
  国内免费   11篇
耳鼻咽喉   48篇
儿科学   219篇
妇产科学   139篇
基础医学   568篇
口腔科学   61篇
临床医学   338篇
内科学   1394篇
皮肤病学   115篇
神经病学   419篇
特种医学   276篇
外科学   1091篇
综合类   155篇
一般理论   1篇
预防医学   178篇
眼科学   266篇
药学   393篇
中国医学   15篇
肿瘤学   246篇
  2023年   39篇
  2022年   75篇
  2021年   186篇
  2020年   87篇
  2019年   124篇
  2018年   158篇
  2017年   108篇
  2016年   147篇
  2015年   166篇
  2014年   220篇
  2013年   255篇
  2012年   412篇
  2011年   427篇
  2010年   244篇
  2009年   200篇
  2008年   332篇
  2007年   355篇
  2006年   327篇
  2005年   281篇
  2004年   297篇
  2003年   244篇
  2002年   212篇
  2001年   118篇
  2000年   100篇
  1999年   75篇
  1998年   53篇
  1997年   31篇
  1996年   23篇
  1995年   21篇
  1994年   18篇
  1993年   20篇
  1992年   44篇
  1991年   38篇
  1990年   44篇
  1989年   35篇
  1988年   28篇
  1987年   31篇
  1986年   36篇
  1985年   26篇
  1984年   34篇
  1983年   26篇
  1982年   20篇
  1979年   14篇
  1978年   16篇
  1977年   15篇
  1975年   13篇
  1974年   13篇
  1973年   13篇
  1968年   13篇
  1967年   13篇
排序方式: 共有5922条查询结果,搜索用时 15 毫秒
101.

Background

Emergency departments rely on CT scans to manage trauma victims, especially for head injuries. Although the detection of an undisplaced fracture on a CT scan of the head without significant intracranial findings may be insignificant for a clinician, such cases are of paramount importance for medico-legal purposes because they help ascertain the nature, manner, and cause of the head injury.

Aims

The study was conducted with the objective of knowing the sensitivity and specificity of ante-mortem CT scan findings indicating the presence or absence of skull fractures.

Methods

Findings were confirmed during post-mortem examination of the subjects who had died during management but who had not had any surgical intervention. A comparative study of ante-mortem CT scan and autopsy findings with respect to fracture in traumatic head injuries was undertaken on 60 deceased individuals brought in for medico-legal post-mortem examination over a period of two years.

Results

Considering the autopsy findings as the gold standard, we have concluded that 14.6 per cent of the fractures were missed on CT scan findings compared to fractures found during autopsy. The sensitivity of CT scan for skull fractures was found to be 85.4 per cent and specificity was 100 per cent. Kappa was 0.787, which shows good agreement with p<0.001, which was highly significant.

Conclusion

In developing countries, images are interpreted in the axial plane only on a CT scan of the head, which may be due to a lack of financial and human resources. For better delineation of fractures, the use of techniques like multi-detector CT with sagittal and coronal reformations should be considered in the routine interpretation of a CT scan of the head.  相似文献   
102.
103.
Variant Creutzfeldt-Jakob disease (vCJD) is a rare, fatal prion disease resulting from transmission to humans of the infectious agent of bovine spongiform encephalopathy. We describe the clinical presentation of a recent case of vCJD in the United States and provide an update on diagnostic testing. The location of this patient’s exposure is less clear than those in the 3 previously reported US cases, but strong evidence indicates that exposure to contaminated beef occurred outside the United States more than a decade before illness onset. This case exemplifies the persistent risk for vCJD acquired in unsuspected geographic locations and highlights the need for continued global surveillance and awareness to prevent further dissemination of vCJD.  相似文献   
104.
Clinical Rheumatology - This study aims to assess rheumatologists’ perceptions, utilization patterns, and attitudes towards the modified New York (mNY) criteria for ankylosing spondylitis...  相似文献   
105.
Glanzmann thrombasthenia (GT) is an autosomal recessive platelet function disorder characterized by mucocutaneous bleeding as the most common clinical phenotype. Patients with GT have normal platelet counts, platelet morphology but reduced platelet aggregation in response to various agonists. Homozygosity or compound heterozygosity for variants in the ITGA2B/ITGB3 genes is the genetic basis for GT. Establishing a molecular diagnosis is definitive and is important for predictive testing. Using multi-gene panels is an accurate, faster, and cost-effective mode as compared to Sanger sequencing in large genes. We used a targeted resequencing based approach to identify pathogenic variants in eight cases in seven families. These variants were validated using Sanger sequencing in patients as well as family members and were predicted probably pathogenic using in-silico prediction tools. The variants include three missense (3/7 = 43%) (ITGA2B:c.1028 T > C, ITGA2B:c.1186G > A, ITGB3:c.1388G > C), two deletions (ITGA2B:c.559delG, ITGA2B:c.3092delT), one duplication (ITGA2B:c.1424_1427dupAGGT) and nonsense variant (ITGA2B:c.2578C > T, p.Gln860Ter). Except for one case which was compound heterozygous, the rest of the cases were homozygous. We found two novel variants that are reported for the first time in GT. The targeted resequencing based approach revealed varied genetic variants in North Indian patients, including two novels ones. The high yield of our panel indicates its suitability for usage in larger cohorts for the genetic diagnosis of GT patients. This approach is cost-effective and less cumbersome as compared to Sanger sequencing for these large size genes with multiple exons. The information so obtained is helpful in prenatal testing, carrier analysis, and genetic counseling.  相似文献   
106.
107.
108.
Alveolar haemorrhage is a catastrophic though rare complication of systemic lupus erythematosus (SLE) and is associated with a high mortality rate with most studies showing a mortality of 23–92%. The treatment modalities available for such complications are pulse cyclophosphamide therapy with steroids and plasmapheresis in patients who do no respond to the above treatment. We report here a case of SLE with alveolar haemorrhage that despite being on immunomodulatory therapy developed alveolar haemorrhage and did not respond to plasmapheresis.  相似文献   
109.
The alterations in serum levels of T3, T4, TSH and TBG, TSH response to 100 mug iv TRH, and urinary excretion of T3 and T4 were studied in 8 healthy men at sea level (SL), on days 1, 2, 4, 8 and 16 after arrival by air at high altitude (3,700 m, HA), and during days 5 to 7 after their return to SL. No significant alterations in serum levels of TSH and TBG or TSH response to TRH were observed during exposure to HA or on return to SL. There was, however, an acute elevation in both serum total T3 and T4. Serum total T3 from a mean basal+/-SE value of 128+/-13 ng/dl increased to 320+/-18 on day 1 and remained significantly elevated at 225+/-48 up to day 8 after arrival at high altitude. Similarly serum total T4 increased from basal level of 9+/-0.92 mug/dl to 15.2+/-1.2 and remained elevated till day 16 and it was 11+/-1.19 mug/dl during days 5 to 7 after return to SL. The urinary excretion of both T3 and T4 was decreased. These changes perhaps were the result of complex physiologic adjustments on acute exposure to high altitude, like shrinkage of the T3 and T4 distribution pools, altered binding capacities of thyroid hormones binding proteins, and a reduction in clearance of thyroid hormones from the plasma compartment; and were probably not suggestive of an enhanced thyroid activity. Their actual significance in high altitude adaptation in man is not clearly understood.  相似文献   
110.
GOALS: To report the use of pH-impedance testing in evaluating patients with suspected gastroesophageal reflux disease (GERD) with atypical symptoms. BACKGROUND: Although the role of acid reflux in causing atypical GERD symptoms is generally accepted, the role, if any, of nonacid reflux is controversial, largely because until recently it has not been possible to detect nonacid reflux. The advent of intraluminal combined pH impedance testing (MII-pH), to detect nonacid reflux has heightened interest in its possible contribution to atypical symptoms. STUDY: Fifty consecutive patients referred for MII-pH testing to evaluate the cause of atypical symptoms presumed due to GERD were evaluated. The symptoms were either refractory to acid inhibition therapy or so atypical that further work up was desired by the referring physician. Patients underwent MII-pH testing to determine whether reflux was present, and, if so, if it was due to acid, nonacid, or gas. RESULTS: Only 16%, 22%, and 2% patients were found to have symptoms due to acid reflux, nonacid reflux, or both, respectively. Ten percent of these patients had gas reflux. MII-pH testing was useful in redirecting the management of patients who did not have reflux as the cause of their symptoms. CONCLUSIONS: MII-pH testing is useful in determining whether gastroesophageal reflux is present in patients with atypical symptoms that have not responded to proton pump inhibitor therapy. It also distinguishes between reflux due to acid, nonacid, and gas, with consequences for management.  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