全文获取类型
收费全文 | 1604篇 |
免费 | 143篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 32篇 |
儿科学 | 46篇 |
妇产科学 | 18篇 |
基础医学 | 159篇 |
口腔科学 | 35篇 |
临床医学 | 163篇 |
内科学 | 326篇 |
皮肤病学 | 19篇 |
神经病学 | 85篇 |
特种医学 | 73篇 |
外科学 | 358篇 |
综合类 | 17篇 |
预防医学 | 90篇 |
眼科学 | 53篇 |
药学 | 92篇 |
中国医学 | 4篇 |
肿瘤学 | 199篇 |
出版年
2023年 | 7篇 |
2022年 | 15篇 |
2021年 | 33篇 |
2020年 | 23篇 |
2019年 | 42篇 |
2018年 | 36篇 |
2017年 | 38篇 |
2016年 | 35篇 |
2015年 | 60篇 |
2014年 | 66篇 |
2013年 | 72篇 |
2012年 | 99篇 |
2011年 | 120篇 |
2010年 | 63篇 |
2009年 | 63篇 |
2008年 | 79篇 |
2007年 | 92篇 |
2006年 | 92篇 |
2005年 | 89篇 |
2004年 | 82篇 |
2003年 | 82篇 |
2002年 | 56篇 |
2001年 | 50篇 |
2000年 | 37篇 |
1999年 | 27篇 |
1998年 | 18篇 |
1997年 | 20篇 |
1996年 | 16篇 |
1995年 | 11篇 |
1994年 | 11篇 |
1993年 | 11篇 |
1992年 | 28篇 |
1991年 | 17篇 |
1990年 | 19篇 |
1989年 | 13篇 |
1988年 | 11篇 |
1987年 | 12篇 |
1986年 | 16篇 |
1985年 | 9篇 |
1984年 | 9篇 |
1983年 | 10篇 |
1982年 | 7篇 |
1981年 | 5篇 |
1980年 | 9篇 |
1979年 | 6篇 |
1977年 | 10篇 |
1976年 | 8篇 |
1975年 | 7篇 |
1974年 | 7篇 |
1972年 | 6篇 |
排序方式: 共有1769条查询结果,搜索用时 62 毫秒
51.
Amidolytic assay of human factor XI in plasma: comparison with a coagulant assay and a new rapid radioimmunoassay 总被引:6,自引:0,他引:6
The traditional coagulant assay for plasma factor XI suffers from a relatively high coefficient of variation, the need for rare congenitally deficient plasma, and a poor correlation between precision and sensitivity. We have developed a simple functional amidolytic assay for factor XI in plasma using the chromogenic substrate PyrGlu-Pro-Arg- p-nitroanilide (S-2366). After inactivation of alpha 1-antitrypsin, CI inhibitor, and other plasma protease inhibitors with CHCI3, plasma was incubated with kaolin, in the absence of added calcium, which limited the enzymes formed to those dependent on contact activation. Soybean trypsin inhibitor was used to minimize the action of kallikrein on the substrate. Once the reaction was complete, corn trypsin inhibitor was used to inactive factor XIIa, the enzyme generated by exposure of plasma to negatively charged surfaces, which had activated the factor XI. The assay is highly specific for factor XI, since plasma totally deficient in that zymogen yielded only 1%-3% of the enzymatic activity in normal plasma under identical conditions. The requirements for complete conversion of factor XI to XIa in plasma within 60 min were, respectively, factor XII, 0.6 U/ml, and high molecular weight kininogen, 0.2 U/ml. Prekallikrein was not an absolute requirement for complete activation but did accelerate the reaction. The intraassay coefficient of variation was 3.4%, and the mean of 35 normal plasmas was 1.00 U +/- 0.24 SD. In addition, a new rapid radioimmunoassay was devised using staphylococcal protein A as the precipitating agent for a complex of factor XI antigen with monospecific rabbit antibody. The mean was 1.01 U +/- 0.30 SD. The correlation coefficients for amidolytic versus coagulant and amidolytic versus radioimmunoassay were r = 0.95 for the former and 0.96 for the latter. Thus, a simple, accurate amidolytic assay and a radioimmunoassay have been devised for measuring factor XI in plasma that correlate well with the coagulant activity of factor XI, as determined in our laboratory. 相似文献
52.
53.
54.
Mariacristina Scoto Thomas Cullup Sebahattin Cirak Shu Yau Adnan Y Manzur Lucy Feng Thomas S Jacques Glenn Anderson Stephen Abbs Caroline Sewry Heinz Jungbluth Francesco Muntoni 《European journal of human genetics : EJHG》2013,21(11):1249-1252
Recessive nebulin (NEB) mutations are a common cause of nemaline myopathy (NM), typically characterized by generalized weakness of early-onset and nemaline rods on muscle biopsy. Exceptional adult cases with additional cores and an isolated distal weakness have been reported. The large NEB gene with 183 exons has been an obstacle for the genetic work-up. Here we report a childhood-onset case with distal weakness and a core-rod myopathy, associated with recessive NEB mutations identified by next generation sequencing (NGS). This 6-year-old boy presented with a history of gross-motor difficulties following a normal early development. He had distal leg weakness with bilateral foot drop, as well as axial muscle weakness, scoliosis and spinal rigidity; additionally he required nocturnal respiratory support. Muscle magnetic resonance (MR) imaging showed distal involvement in the medial and anterior compartment of the lower leg. A muscle biopsy featured both rods and cores. Initial targeted testing identified a heterozygous Nebulin exon 55 deletion. Further analysis using NGS revealed a frameshifting 4 bp duplication, c.24372_24375dup (P.Val8126fs), on the opposite allele. This case illustrates that NEB mutations can cause childhood onset distal NM, with additional cores on muscle biopsy and proves the diagnostic utility of NGS for myopathies, particularly when large genes are implicated. 相似文献
55.
56.
57.
Alan M. Rathbun Elizabeth A. Stuart Michelle Shardell Michelle S. Yau Mona Baumgarten Marc C. Hochberg 《Arthritis care & research》2018,70(1):80-88
Objective
To estimate the dynamic causal effects of depressive symptoms on osteoarthritis (OA) knee pain.Methods
Marginal structural models were used to examine dynamic associations between depressive symptoms and pain over 48 months among older adults (n = 2,287) with radiographic knee OA (Kellgren/Lawrence grade 2 or 3) in the Osteoarthritis Initiative. Depressive symptoms at each annual visit were assessed (threshold ≥16) using the Center for Epidemiologic Studies Depression Scale. OA knee pain was measured using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale, rescaled to range from 0 to 100.Results
Depressive symptoms at each visit were generally not associated with greater OA knee pain at subsequent time points. Causal mean differences in WOMAC pain score comparing depressed to nondepressed patients ranged from 1.78 (95% confidence interval [95% CI] ?0.73, 4.30) to 2.58 (95% CI 0.23, 4.93) within the first and fourth years, and the depressive symptoms by time interaction were not statistically significant (P = 0.94). However, there was a statistically significant dose‐response relationship between the persistence of depressive symptoms and OA knee pain severity (P = 0.002). Causal mean differences in WOMAC pain score comparing depressed to nondepressed patients were 0.89 (95% CI ?0.17, 1.96) for 1 visit with depressive symptoms, 2.35 (95% CI 0.64, 4.06) for 2 visits with depressive symptoms, and 3.57 (95% CI 0.43, 6.71) for 3 visits with depressive symptoms.Conclusion
The causal effect of depressive symptoms on OA knee pain does not change over time, but pain severity significantly increases with the persistence of depressed mood.58.
59.
Risk factors for seizures and antiepileptic drug‐associated adverse effects in high‐grade glioma patients: A multicentre,retrospective study in Hong Kong
下载免费PDF全文
![点击此处可从《Surgical Practice》网站下载免费的PDF全文](/ch/ext_images/free.gif)
60.
Weiland BJ Nigg JT Welsh RC Yau WY Zubieta JK Zucker RA Heitzeg MM 《Alcoholism, clinical and experimental research》2012,36(8):1355-1364