全文获取类型
收费全文 | 295185篇 |
免费 | 41679篇 |
国内免费 | 3045篇 |
学科分类
医药卫生 | 339909篇 |
出版年
2024年 | 561篇 |
2023年 | 5352篇 |
2022年 | 1860篇 |
2021年 | 5742篇 |
2020年 | 7771篇 |
2019年 | 4863篇 |
2018年 | 10501篇 |
2017年 | 9696篇 |
2016年 | 11142篇 |
2015年 | 11582篇 |
2014年 | 19990篇 |
2013年 | 21855篇 |
2012年 | 15653篇 |
2011年 | 16278篇 |
2010年 | 16308篇 |
2009年 | 19733篇 |
2008年 | 15668篇 |
2007年 | 14639篇 |
2006年 | 16527篇 |
2005年 | 14121篇 |
2004年 | 12827篇 |
2003年 | 11326篇 |
2002年 | 10854篇 |
2001年 | 5134篇 |
2000年 | 4034篇 |
1999年 | 4679篇 |
1998年 | 5636篇 |
1997年 | 4980篇 |
1996年 | 4671篇 |
1995年 | 4379篇 |
1994年 | 3016篇 |
1993年 | 2617篇 |
1992年 | 2103篇 |
1991年 | 2147篇 |
1990年 | 1634篇 |
1989年 | 1746篇 |
1988年 | 1554篇 |
1987年 | 1395篇 |
1986年 | 1361篇 |
1985年 | 1231篇 |
1984年 | 1166篇 |
1983年 | 1070篇 |
1982年 | 1252篇 |
1981年 | 1094篇 |
1980年 | 948篇 |
1979年 | 666篇 |
1978年 | 680篇 |
1977年 | 781篇 |
1976年 | 549篇 |
1975年 | 554篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
71.
72.
73.
Anders Elm Pedersen Esben Gjerløff Wedebye Schmidt Jesper Freddie Sørensen Carsten Faber Boye Schnack Nielsen Kim Holmstrøm Silje Haukali Omland Peter Tougaard Søren Skov Bo Bang 《APMIS : acta pathologica, microbiologica, et immunologica Scandinavica》2015,123(7):547-555
TL1A is a TNF‐like cytokine which has been shown to co‐stimulate TH1 and TH17 responses during chronic inflammation. The expression of this novel cytokine has been investigated in inflammatory disorders like rheumatoid arthritis and inflammatory bowel disease, but little is known about expression and induction in psoriasis. Indeed, the pathogenesis in psoriasis is still not fully understood and it is speculated that cytokines other than TNF‐α are important in subsets of patients. Also, for patients with severe disease that are treated with systemic anti‐TNF‐α blockade, novel candidates to be used as disease and response biomarkers are of high interest. Here, we demonstrate TL1A expression in biopsies from psoriatic lesions. Also, we investigated spontaneous and induced TL1A secretion from PBMCs and blood levels from a cohort of psoriasis patients. Here, increased spontaneous secretion from PBMCs was observed as compared to healthy controls and a small subset of patients had highly elevated TL1A in the blood. Interestingly, activation of PBMCs with various cytokines showed a decreased sensitivity for TL1A activation in psoriasis patients compared to healthy controls.TL1A levels in blood and biopsies could not be correlated with disease activity with this patient cohort. Thus, additional large‐scale studies are warranted to investigate TL1A as a biomarker. 相似文献
74.
Breast Elastography: How to Perform and Integrate Into a “Best-Practice” Patient Treatment Algorithm
Breast elastography has been available for more than 15 years but is not widely incorporated into clinical practice. Many publications report extremely high accuracy for various breast elastographic techniques. However, results in the literature are extremely variable. This variability is most likely due to variations in technique, a relatively steep learning curve, and variability in methods between vendors. This article describes our protocol for performing breast elastography using both strain elastography and shear wave elastography, which produces high sensitivity and specificity. Additionally, we will describe the most commonly known false-positive and false-negative lesions as well as how to detect them. 相似文献
75.
76.
Accuracy and Precision of Acetabular Component Placement With Imageless Navigation in Obese Patients
Leonard T. Buller Alexander S. McLawhorn Jose A. Romero Peter K. Sculco David J. Mayman 《The Journal of arthroplasty》2019,34(4):693-699
Background
Obesity is a risk factor for acetabular component malposition when total hip arthroplasty is performed with manual techniques. The utility of imageless navigation in obese patients remains unknown. This study compared the accuracy and precision of imageless navigation for component orientation between obese and nonobese patients.Methods
A total of 459 total hip arthroplasties performed for osteoarthritis using imageless navigation were reviewed from a single surgeon’s institutional review board–approved database. Einzel-Bild-Roentgen Analyse determined component orientation on 6-week postoperative anteroposterior radiographs. Mean orientation error (accuracy) and precision were compared between obese (body mass index ≥ 30 kg/m2) and nonobese patients. Regression analysis evaluated the influence of obesity on component position.Results
The difference in mean inclination and anteversion between obese and nonobese groups was 1.1° (43.0° ± 3.5°; range, 35.8°-57.8° vs 41.9° ± 4.4°; range, 33.0°-57.1° and 24.9° ± 6.3°; range, 14.2°-44.3° vs 23.8° ± 6.6°; range, 7.0°-38.6°, respectively). Inclination precision was better for nonobese patients. No difference in inclination accuracy or anteversion accuracy or precision was detected between groups. And 83% of components were placed within the target range. There was no relationship between obesity (dichotomized) and component placement outside the target ranges for inclination, anteversion, or both. As a continuous variable, increased body mass index correlated with higher odds of inclination outside the target zone (odds ratio, 1.06; P = .001).Conclusion
Using imageless navigation, inclination orientation was less precise for obese patients, but the observed difference is likely not clinically relevant. Accurate superficial registration of landmarks in obese patients is achievable, and the use of imageless navigation similarly improves acetabular component positioning in obese and nonobese patients.Level of Evidence
Therapeutic Level IV. 相似文献77.
78.
The term “oligometastatic prostate cancer” refers to a heterogeneous group of disease states currently defined solely on the basis of clinical features. Oligorecurrent disease, de novo oligometastases, and oligoprogressive disease likely have unique biologic underpinnings and natural histories. Evidence suggesting the existence of a subset of patients who harbor prostate cancer with limited metastatic potential currently includes disparate and overwhelmingly retrospective reports. Nevertheless, emerging prospective data have corroborated the “better-than-expected,” retrospectively observed outcomes, particularly in the setting of oligorecurrent prostate cancer. Improved functional imaging with prostate-specific membrane antigen-targeted strategies may enhance the identification of patients with oligometastatic prostate cancer in the short term. In the long term, refinement of the oligometastatic case definition likely will require biologic risk-stratification schemes. To determine optimal treatment strategies and identify patients most likely to benefit from metastasis-directed therapy, future efforts should focus on conducting high-quality, prospective trials with much-needed molecular correlative studies. 相似文献
79.
80.