全文获取类型
收费全文 | 1434011篇 |
免费 | 96073篇 |
国内免费 | 2375篇 |
专业分类
耳鼻咽喉 | 20490篇 |
儿科学 | 48073篇 |
妇产科学 | 42591篇 |
基础医学 | 207577篇 |
口腔科学 | 40055篇 |
临床医学 | 120249篇 |
内科学 | 278971篇 |
皮肤病学 | 30224篇 |
神经病学 | 108944篇 |
特种医学 | 59023篇 |
外国民族医学 | 459篇 |
外科学 | 221048篇 |
综合类 | 27448篇 |
现状与发展 | 1篇 |
一般理论 | 301篇 |
预防医学 | 105930篇 |
眼科学 | 32631篇 |
药学 | 108765篇 |
3篇 | |
中国医学 | 2599篇 |
肿瘤学 | 77077篇 |
出版年
2018年 | 15037篇 |
2017年 | 12482篇 |
2016年 | 12931篇 |
2015年 | 15852篇 |
2014年 | 19677篇 |
2013年 | 27226篇 |
2012年 | 42017篇 |
2011年 | 39885篇 |
2010年 | 23031篇 |
2009年 | 23310篇 |
2008年 | 36641篇 |
2007年 | 40197篇 |
2006年 | 40930篇 |
2005年 | 47735篇 |
2004年 | 47789篇 |
2003年 | 42666篇 |
2002年 | 37685篇 |
2001年 | 61262篇 |
2000年 | 60819篇 |
1999年 | 54869篇 |
1998年 | 14641篇 |
1997年 | 13012篇 |
1996年 | 13344篇 |
1995年 | 12630篇 |
1994年 | 12010篇 |
1992年 | 46116篇 |
1991年 | 45676篇 |
1990年 | 45384篇 |
1989年 | 43951篇 |
1988年 | 40943篇 |
1987年 | 40055篇 |
1986年 | 38157篇 |
1985年 | 36146篇 |
1984年 | 26660篇 |
1983年 | 23014篇 |
1982年 | 13143篇 |
1981年 | 11522篇 |
1979年 | 25598篇 |
1978年 | 17713篇 |
1977年 | 15101篇 |
1976年 | 14175篇 |
1975年 | 16095篇 |
1974年 | 19099篇 |
1973年 | 18239篇 |
1972年 | 17481篇 |
1971年 | 16351篇 |
1970年 | 15253篇 |
1969年 | 14711篇 |
1968年 | 13758篇 |
1967年 | 12230篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Torbj?rn Karlsson 《Upsala journal of medical sciences》2015,120(4):257-262
Background. Haemophagocytic lymphohistiocytosis (HLH) is a rare clinical syndrome characterized by fever, hepatosplenomegaly, cytopenia, and progressive multiple-organ failure. HLH in adults is often secondary to autoimmune diseases, cancer, or infections in contrast to familial HLH. Treatment of secondary HLH is directed against the triggering disease in addition to immunosuppressive therapy, the latter commonly according to the HLH-2004 protocol.Methods. We conducted a retrospective study to identify triggering diseases, disease-specific and immunosuppressive therapy administered, and prognosis in adult patients with secondary HLH. Patient data were collected from October 2010 to January 2015.Results. Ten adult patients with secondary HLH were identified. Seven were men, and the median age at diagnosis was 62 years. Five cases were triggered by malignant disease and five by infection. The median patient fulfilled five of the eight HLH-2004 diagnostic criteria. All patients fulfilled the criteria fever, cytopenia, and ferritin >500 µg/L. Median time from hospital admission to HLH diagnosis was 20 days. Four patients received immunosuppressive therapy according to the HLH-2004 protocol. The prognosis was dismal, especially for the patients with malignancy-associated HLH, of whom all died.Conclusion. HLH should be suspected in patients who present with fever, cytopenia, and ferritin >500 µg/L. Secondary HLH has a dismal prognosis. None of the patients with HLH triggered by malignancy survived. Achieving remission of the triggering disease seems to be important for a favourable outcome as, in all surviving patients, the haemophagocytic syndrome resolved after remission of the underlying infection. 相似文献
52.
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
53.
54.
55.
Turnbull Chris D. Stockley James A. Madathil Shyam Huq Syed S. A. Cooper Brendan G. Ali Asad Wharton Simon Stradling John R. Heitmar Rebekka 《Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie》2022,260(7):2129-2139
Graefe's Archive for Clinical and Experimental Ophthalmology - Retinal microvascular endothelial dysfunction is thought to be of importance in the development of ocular vascular diseases.... 相似文献
56.
M. Zamparas V.C. Kapsalis G.L. Kyriakopoulos K.G. Aravossis A.E. Kanteraki A. Vantarakis I.K. Kalavrouziotis 《Sustainable Chemistry and Pharmacy》2019
At this study a multi-criteria model was developed to examine the available procedures, techniques and methods of handling infectious waste in the large healthcare unit of University Regional General Hospital of Patras, Western Greece. Particularly, this study examined the: a) current legislation and Directives issued for medical waste management at Greece and among the other EU-members, b) contribution of healthcare wastes (HCW) generation rate on social and economic parameters in selected European countries, c) available procedures, techniques, and methods upon the disposal of infectious wastes at the healthcare studied, and, d) propositions for integrated management of such hazardous wastes. Specifically, the Analytic Hierarchy Process (AHP) methodology was applied under pair wise comparison matrices in two stages: 1) the scale factors and the indicators, and 2) the criteria and their sub–criteria. The assessment of these pair wise matrices included the indicators and the sub–criteria. Subsequently, two pair wise comparison matrices, upon a) the “Fulfillment of environmental objectives” indicator and b) the “Energy consumption” sub criterion, were denoted. The AHP methodology yielded good results; however there is still space of improving the environmental performance. The normalized relative weights obtained for the criteria and sub criteria motivated specific actions that have to be handled. Particularly, the results indicated a very good value in environmental management criteria due the values obtained for the commitment towards the environmental policy standards and the waste management procedures. However, further improvements on staff awareness (such as development programs to enhance sensitivity) and more green purchasing suppliers, should be further addressed. 相似文献
57.
58.
Anastasiia Panfilova Sarah E. Shelton Cristina Caresio Ruud J.G. van Sloun Filippo Molinari Hessel Wijkstra Paul A. Dayton Massimo Mischi 《Ultrasound in medicine & biology》2019,45(2):539-548
Dynamic contrast-enhanced ultrasound (DCE-US) has been proposed as a powerful tool for cancer diagnosis by estimation of perfusion and dispersion parameters reflecting angiogenic vascular changes. This work was aimed at identifying which vascular features are reflected by the estimated perfusion and dispersion parameters through comparison with acoustic angiography (AA). AA is a high-resolution technique that allows quantification of vascular morphology. Three-dimensional AA and 2-D DCE-US bolus acquisitions were used to monitor the growth of fibrosarcoma tumors in nine rats. AA-derived vascular properties were analyzed along with DCE-US perfusion and dispersion to investigate the differences between tumor and control and their evolution in time. AA-derived microvascular density and DCE-US perfusion exhibited good agreement, confirmed by their spatial distributions. No vascular feature was correlated with dispersion. Yet, dispersion provided better cancer classification than perfusion. We therefore hypothesize that dispersion characterizes vessels that are smaller than those visible with AA. 相似文献
59.
Willy Baccaglini Felipe A. Glina Cristiano Linck Pazeto Luis G. Medina Fernando Korkes Wanderley M. Bernardo Rene Sotelo Sidney Glina Giancarlo Marra Marco Moschini Xavier Cathelineau Rafael Sanchez-Salas 《Clinical genitourinary cancer》2021,19(1):3-11.e1
This meta-analysis focuses on the accuracy of upgrading to clinically significant prostate cancer (PCa) by multiparametric magnetic resonance imaging-targeted biopsy (MRI-TB) versus systematic biopsy (SB). We searched the Medline, Embase, Cochrane Central Register of Controlled Trials, Web of Science, Scopus, and Literatura Latino Americana em Ciências da Saúde databases through January 2020 for comparative, retrospective/prospective, paired-cohort, and randomized clinical trials with paired comparisons. The population consisted of patients with low-risk PCa in active surveillance with at least 1 index lesion on imaging. We evaluated the quality of evidence by using the Quality Assessment of Diagnostic Accuracy Studies-2 score. Group comparisons considered the differences between the area under the curve summary receiver operating characteristic curve in a 2-tailed method. We also compared the positive predictive value of the best single method (MRI-TB or SB) and the referral study test (combined biopsy, a combination of MRI-TB and SB). The meta-analysis included 6 studies enrolling 741 patients. The pooled sensitivity for the 2 groups was 0.79 (95% confidence interval, 0.74-0.83; I2 = 75%) and 0.67 (95% confidence interval, 0.63-0.74; I2 = 55.4%), respectively. The area under the curve for the MRI-TB and SB groups were 0.99 and 0.92 (P < .001), respectively. The positive predictive value for the MRI-TB and combined biopsy groups were similar. The accumulated evidence suggests better results for MRI-TB compared with SB. Therefore, use of MRI-TB alone may be preferable in patients in active surveillance harboring low-risk PCa. 相似文献
60.
Adequate postoperative analgesia is a key element of enhanced recovery programmes. Thoracic epidural analgesia is associated with superior postoperative analgesia but can lead to complications. Rectus sheath catheter analgesia may provide an alternative. In a nested qualitative study (within a two-year randomised controlled trial) focussing on the acceptability, expectations and experiences of receiving the interventions, participants (n = 20) were interviewed 4 weeks post-intervention using a grounded theory approach. Constant comparative analysis, with patient and public involvement, enabled emerging findings to be pursued through subsequent data collection. We found no notable differences regarding postoperative acceptability or the experience of pain management. Pre-operatively, however, thoracic epidural analgesia was a source of anticipatory fear and anxiety. Both interventions resulted in some experienced adverse events (proportionately more with thoracic epidural analgesia). Participants had negative experiences of the insertion of thoracic epidural analgesia; others receiving the rectus sheath catheter lacked confidence in staff members' ability to manage the local anaesthetic infusion pump. The anticipation of the technique of thoracic epidural analgesia, and concerns about its impact on mobility, represented an additional, unpleasant experience for patients already managing an illness experience, anticipating a life-changing operation and dealing with concerns about the future. The anticipation of rectus sheath catheter analgesia was not associated with such anxieties. Patients' experiences start far earlier than the experience of the intervention itself through anticipatory anxieties and fears about receiving a technique and its potential implications. Complex pain packages can take on greater meaning than their actual efficacy in relieving postoperative pain. Future research into patient acceptability and experience should not focus solely on efficacy of pain relief but should include anticipatory fears, anxieties and experiences. 相似文献