全文获取类型
收费全文 | 2577篇 |
免费 | 136篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 56篇 |
儿科学 | 110篇 |
妇产科学 | 51篇 |
基础医学 | 227篇 |
口腔科学 | 55篇 |
临床医学 | 250篇 |
内科学 | 500篇 |
皮肤病学 | 23篇 |
神经病学 | 204篇 |
特种医学 | 69篇 |
外国民族医学 | 7篇 |
外科学 | 533篇 |
综合类 | 37篇 |
一般理论 | 2篇 |
预防医学 | 179篇 |
眼科学 | 54篇 |
药学 | 188篇 |
中国医学 | 2篇 |
肿瘤学 | 174篇 |
出版年
2023年 | 21篇 |
2022年 | 42篇 |
2021年 | 81篇 |
2020年 | 58篇 |
2019年 | 71篇 |
2018年 | 90篇 |
2017年 | 74篇 |
2016年 | 69篇 |
2015年 | 65篇 |
2014年 | 100篇 |
2013年 | 125篇 |
2012年 | 232篇 |
2011年 | 222篇 |
2010年 | 110篇 |
2009年 | 87篇 |
2008年 | 162篇 |
2007年 | 172篇 |
2006年 | 148篇 |
2005年 | 121篇 |
2004年 | 135篇 |
2003年 | 96篇 |
2002年 | 99篇 |
2001年 | 36篇 |
2000年 | 25篇 |
1999年 | 27篇 |
1998年 | 16篇 |
1997年 | 4篇 |
1996年 | 21篇 |
1995年 | 13篇 |
1994年 | 7篇 |
1993年 | 6篇 |
1992年 | 23篇 |
1991年 | 19篇 |
1990年 | 12篇 |
1989年 | 12篇 |
1988年 | 20篇 |
1987年 | 14篇 |
1986年 | 9篇 |
1985年 | 7篇 |
1984年 | 6篇 |
1983年 | 6篇 |
1982年 | 6篇 |
1981年 | 5篇 |
1979年 | 9篇 |
1977年 | 3篇 |
1975年 | 8篇 |
1972年 | 3篇 |
1971年 | 3篇 |
1968年 | 4篇 |
1965年 | 3篇 |
排序方式: 共有2721条查询结果,搜索用时 15 毫秒
41.
Laila M. Elmaghawry Ibtesam I. El-Dosouky Nader T. Kandil Ahmad Mohammad Sayyid-Ahmad Sayyid-Ahmad 《The international journal of cardiovascular imaging》2018,34(4):523-529
It is frequent to see pulmonary hypertension (PH) in patients with mitral stenosis (MS) secondary to increased pulmonary vascular resistance (PVR), data about the effect of PVR on the results of percutaneous balloon mitral valvotomy (PBMV) are insufficient. To detect the role of PVR in predicting residual PH immediately after PBMV. This prospective study comprised 49 consecutive patients with moderate to severe MS who were investigated pre and within 48 h post a successful PBMV for the first time. Echocardiography was used to assess the mitral valve area (MVA), mean transmitral pressure gradient (MPG), mitral valve resistance (MVR), right ventricular systolic pressure (RVSP) and PVR. Patients were classified into two groups according to the pre PVR (≥?1.6 WU as group I and < 1.6 as group II). At baseline compared to group II (32 patients), Group I (17 patients) had higher MPG (13.6?±?5.2 vs. 11.7?±?3.7 mmHg, P?<?0.05), RVSP (45.6 vs. 37.9 mmHg, P?<?0.001) and PVR (2.2?±?0.1 vs. 1.2?±?0.1WU, P?<?0.001) with no significant difference regarding age, gender, MVS, MVA and MVR. Patients of group I had comparatively lower improvement immediate post procedural of RVSP and PVR with no significant difference in immediate post procedural improvement in NYHA classification, MVA, MPG and MVR. Basal PVR?>?1.8WU was proved to be a highly specific (91%), a good predictor (AUC 0.78) of persistent elevation of RVSP?>?50 mmHg post PMV. Pathological rise of PVR that associates MS had provided a strong and an independent predictor of persistent pulmonary hypertension post PBMV and by this aspect it could be used as a valuable tool as MVA and MPG to send patients earlier for PBMV even with less severe MS. PVR?>?1.81 WU could be used as a noninvasive parameter for predicting regression of PH immediately after PBMV. 相似文献
42.
43.
Nawal D. Alqarni Joanna Wysocka Nader El-Bagoury Jacek Ryl Mohammed A. Amin Rabah Boukherroub 《RSC advances》2018,8(34):19289
The electrochemical and corrosion (uniform and localized) behavior of a binary Ni52Ti48 shape memory alloy (SMA) and two ternary Ni52Ti48−xCox (x = 1.5 and 4.0 wt%) SMAs were studied. Measurements were conducted in 0.9% NaCl solution at 37 °C employing various electrochemical methods. These include: linear polarization resistance (LPR), linear sweep voltammetry (LSV), chronoamperometry and dynamic electrochemical impedance spectroscopy (DEIS). Such measurements were complemented with scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) analysis. Results revealed that the addition of alloyed Co to NiTi significantly reduced the uniform corrosion rate of the studied SMA and greatly enhanced its pitting corrosion resistance. XPS measurements evidenced high stability of the passive layer and limited adsorption of chloride ions. Additionally, it was found that the passive layer remained primarily composed of titanium oxides. Microstructure changes accompanying the addition of Co were also used to account for its role in improving the corrosion resistance of these materials.The electrochemical and corrosion (uniform and localized) behavior of a binary Ni52Ti48 shape memory alloy (SMA) and two ternary Ni52Ti48−xCox (x = 1.5 and 4.0 wt%) SMAs were studied. 相似文献
44.
Salari Nader Kazeminia Mohsen Shohaimi Shamarina Mohammadi Masoud 《Clinical rheumatology》2021,40(11):4511-4525
Clinical Rheumatology - Rheumatoid arthritis is a chronic inflammatory and systemic autoimmune disease associated with synovial fluid inflammatory lesions and articular changes. The aim of the... 相似文献
45.
Aman Mahsa Saffari Hosseinzadeh Mahdi Nokhodchi Nader Bondi Danilo Pietrangelo Tiziana Sardroodian Mahta 《Sport Sciences for Health》2022,18(2):329-339
Sport Sciences for Health - The purpose of this study is to investigate the Bottom–Up Rise Strength Transfer (BURST) induced by massed vs. distributed-rehabilitative exercise training.... 相似文献
46.
47.
Devika Nair Kemberlee Bonnet Marcus G. Wild Ebele M. Umeukeje Rachel B. Fissell Marquetta L. Faulkner Nader S. Bahri Marino A. Bruce David G. Schlundt Kenneth A. Wallston Kerri L. Cavanaugh 《Journal of pain and symptom management》2021,61(1):32-41.e2
ContextPsychological distress is associated with adverse health outcomes in serious illness and magnified among patients of low socioeconomic status. Aspects of one's culture, such as religion and spirituality, can influence these patients' coping response to distress. Advanced chronic kidney disease (CKD) is a serious illness that disproportionately affects patients of low socioeconomic status, but a theory-based understanding of this group's lived experience of CKD is lacking.ObjectivesWe explored the cognitions, emotions, and coping behaviors of patients with CKD with emphasis on those of low socioeconomic status. We further inquired into any influences of religion or spirituality.MethodsWe interviewed 50 English-speaking or Spanish-speaking adults with advanced CKD from three medical centers in Nashville, Tennessee. Analyses occurred with isolation of themes; development of a coding system; and creation of a conceptual framework using an inductive-deductive approach.ResultsMedian age was 65 years; median annual income was $17,500 per year; and 48% of participants had not progressed beyond high school. Key beliefs (awareness of mortality and lack of control) influenced patients' emotions (existential distress in the form of death anxiety, prognostic uncertainty, and hopelessness) and coping behaviors (acceptance, avoidance, emotion regulation via spirituality, and seeking social support via a religious community).ConclusionIndividuals with advanced CKD and low socioeconomic status lack control over disease progression, experience death anxiety and existential distress, and emphasize spirituality to cope. Our study identifies novel components for a psychotherapeutic intervention for patients with advanced CKD at high risk for adverse health outcomes. 相似文献
48.
49.
Fabio D'Aguiar Mataveli Sang Won Han Helena Bonciani Nader Aline Mendes Rose Kanishiro Paulo Tucci 《Growth factors (Chur, Switzerland)》2013,31(1):22-31
Background. Cardiac remodeling is ultimately regulated by components of the extracellular matrix (ECM). We investigated the important role that growth factors play in the regulation of ECM remodeling that occurs as a consequence of myocardium damage.Methods and results. Rats were submitted to the ligation of the left anterior coronary artery and pcDNA3-vascular endothelial growth factor (VEGF)165 was immediately injected intramyocardially in the treated group. The animals were divided into large size myocardium infarction (LMI) and small size myocardium infarction, with or without gene transfer. The plasmid-containing DNA encoding VEGF165 was injected into the cardiac muscle and its effect was observed on the ECM components. Glycosaminoglycans were identified and quantified by agarose gel based electrophoresis and ELISA as well as immunocytochemistry to examine specific cathepsin B, heparanase, and syndecan-4 changes. The amounts of hyaluronic acid (HA; p < 0.005), DS, chondroitin sulfate, and heparan sulfate (p < 0.001) were significantly increased in the LMI treated group in comparison to the other groups, which correlates with the decrease in the expression of heparanase. A decrease in the molecular mass of HA was found in the scar tissue of treated group.Conclusions. The data obtained strongly support the idea that changes in the ECM and its components are important determinants of cardiac remodeling after myocardium infarct and may be essential for inflammatory response and attempt to stabilize the damage and provide a compensatory mechanisms to maintain cardiac output since the ECM components analyzed are involved with angiogenesis, cell proliferation and differentiation. 相似文献
50.
Mohammad Abd Alkhalik Basha Hossam M. Abdelrahman Maha Ibrahime Metwally Nader Ali Alayouty Nesreen Mohey Mohamed M.A. Zaitoun Hosam Nabil Almassry Hala Y. Yousef Ahmed A. El Sammak Sameh Abdelaziz Aly Hesham Youssef Algazzar Mohamed Abd El‐Aziz Mohamed Farag Walid Mosallam Waleed S. Abo Shanab Safaa A. Ibrahim Ekramy A. Mohamed Abd El Motaleb Mohamed Amira Hamed Mohamed Afifi Ola A. Harb Taghreed M. Azmy 《Journal of magnetic resonance imaging : JMRI》2021,53(1):292-304