全文获取类型
收费全文 | 2157篇 |
免费 | 172篇 |
国内免费 | 46篇 |
专业分类
耳鼻咽喉 | 14篇 |
儿科学 | 78篇 |
妇产科学 | 26篇 |
基础医学 | 285篇 |
口腔科学 | 59篇 |
临床医学 | 245篇 |
内科学 | 523篇 |
皮肤病学 | 28篇 |
神经病学 | 92篇 |
特种医学 | 166篇 |
外科学 | 269篇 |
综合类 | 85篇 |
预防医学 | 143篇 |
眼科学 | 85篇 |
药学 | 171篇 |
1篇 | |
中国医学 | 20篇 |
肿瘤学 | 85篇 |
出版年
2023年 | 27篇 |
2022年 | 46篇 |
2021年 | 70篇 |
2020年 | 44篇 |
2019年 | 65篇 |
2018年 | 63篇 |
2017年 | 36篇 |
2016年 | 72篇 |
2015年 | 65篇 |
2014年 | 89篇 |
2013年 | 117篇 |
2012年 | 152篇 |
2011年 | 140篇 |
2010年 | 109篇 |
2009年 | 92篇 |
2008年 | 102篇 |
2007年 | 104篇 |
2006年 | 88篇 |
2005年 | 86篇 |
2004年 | 83篇 |
2003年 | 63篇 |
2002年 | 53篇 |
2001年 | 38篇 |
2000年 | 39篇 |
1999年 | 43篇 |
1998年 | 47篇 |
1997年 | 40篇 |
1996年 | 43篇 |
1995年 | 28篇 |
1994年 | 39篇 |
1993年 | 27篇 |
1992年 | 16篇 |
1991年 | 11篇 |
1990年 | 13篇 |
1989年 | 22篇 |
1988年 | 31篇 |
1987年 | 19篇 |
1986年 | 18篇 |
1985年 | 18篇 |
1984年 | 13篇 |
1983年 | 9篇 |
1982年 | 16篇 |
1981年 | 15篇 |
1980年 | 17篇 |
1979年 | 7篇 |
1978年 | 10篇 |
1977年 | 3篇 |
1976年 | 9篇 |
1975年 | 9篇 |
1974年 | 4篇 |
排序方式: 共有2375条查询结果,搜索用时 15 毫秒
51.
Clarice A. D. Caiuby Akbar Ali Vinicius T. Santana Francisco W. de S. Lucas Marilia S. Santos Arlene G. Corrêa Otaciro R. Nascimento Hao Jiang Mrcio W. Paixo 《RSC advances》2018,8(23):12879
The combination of visible-light and tris(trimethylsilyl)silane promoting intramolecular reductive cyclization protocol for the synthesis of functionalized indolines and 2,3-dihydrobenzofurans has been developed. The transformations occur in the absence of transition metal and additional photocatalyst. In addition, quantum yield (Φ) was determined and electron paramagnetic resonance spectroscopy was performed to better understand the reaction pathway.The combination of visible-light and tris(trimethylsilyl)silane promoting intramolecular reductive cyclization protocol for the synthesis of functionalized indolines and 2,3-dihydrobenzofurans has been developed. 相似文献
52.
Khezri Mehrdad Shokoohi Mostafa Mirzazadeh Ali Tavakoli Fatemeh Ghalekhani Nima Mousavian Ghazal Mehmandoost Soheil Kazerooni Parvin Afsar Haghdoost Ali Akbar Karamouzian Mohammad Sharifi Hamid 《AIDS and behavior》2022,26(9):2831-2843
AIDS and Behavior - Injection drug use has been the leading route of HIV transmission in Iran. We assessed HIV prevalence, risk behaviors, and uptake of prevention services among people who inject... 相似文献
53.
Glycyrrhizin enhances interleukin-10 production by liver dendritic cells in mice with hepatitis 总被引:4,自引:0,他引:4
Background Glycyrrhizin (GL), an aqueous extract of licorice root, is known to have various immune-modulating and biological response-modifier activities. GL is used in patients with hepatitis to reduce the activity of liver inflammation; however, the mechanism underlying the anti-inflammatory activity of GL is poorly understood. As antigen-presenting dendritic cells (DC) in the tissue play a major role in the regulation of the inflammatory mucosal milieu during tissue inflammation, we studied whether the function of liver DC was altered by GL therapy in a murine model of concanavalin-A (Con A)-induced hepatitis.Methods Liver DC were propagated from control mice or mice with Con-A-induced hepatitis, and the effect of GL on liver DC was evaluated in vivo and in vitro.Results The levels of interleukin (IL)-10 produced by liver DC were significantly lower in mice with Con-A-induced hepatitis compared with control mice. However, treatment with GL caused increased production of IL-10 in mice with Con A-induced hepatitis. The increased production of IL-10 by mice with Con A-induced hepatitis was also confirmed in vitro by culturing liver DC with GL.Conclusions This study indicates that increased production of IL-10 by liver DC due to GL administration may be involved in downregulation of the levels of liver inflammation in mice with Con A-induced hepatitis. 相似文献
54.
55.
JD Roberts JC Herkert J Rutberg SM Nikkel ACP Wiesfeld D Dooijes RM Gow JP van Tintelen MH Gollob 《Clinical genetics》2013,83(5):452-456
Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited myocardial disease that predominantly affects the right ventricle and is associated with ventricular arrhythmias that may lead to sudden cardiac death. Mutations within at least seven separate genes have been identified to cause ARVC, however a genetic culprit remains elusive in approximately 50% of cases. Although negative genetic testing may be secondary to pathogenic mutations within undiscovered genes, an alternative explanation may be the presence of large deletions or duplications involving known genes. These large copy number variants may not be detected with standard clinical genetic testing which is presently limited to direct DNA sequencing. We describe two cases of ARVC possessing large deletions involving plakophilin‐2 (PKP2) identified with microarray analysis and/or multiplex ligation‐dependent probe amplification (MLPA) that would have been classified as genotype negative with standard clinical genetic testing. A deletion of the entire coding region of PKP2 excluding exon 1 was identified in patient 1 and his son. In patient 2, MLPA analysis of PKP2 revealed deletion of the entire gene with subsequent microarray analysis demonstrating a de novo 7.9 Mb deletion of chromosome 12p12.1p11.1. These findings support screening for large copy number variants in clinically suspected ARVC cases without clear disease causing mutations following initial sequencing analysis. 相似文献
56.
Asma Akbar Ladak Sonia Sandhu Ahmed Itrat 《Journal of stroke and cerebrovascular diseases》2021,30(6):105728
ObjectivesOur review aims to present existing data on the safety of Intravenous thrombolysis (IVT) use in acute ischemic stroke (AIS) patients with concomitant central nervous system or systemic malignancies, with attention to special circumstances pertaining to specific cancer subtypes to help in acute decision making, especially for neurologists and emergency medicine physicians.MethodsA literature search was conducted on electronic databases inclusive of Medline, EMBASE and CINAHL for articles published or available in English between January 1, 2000 to June 1, 2020 using the following search terms: “acute ischemic stroke,” “cerebrovascular disease,” “Intravenous thrombolysis,” “tissue plasminogen activator,” “cancer patients,” and “neoplasm”.ConclusionRecognition of stroke symptoms in patients with active cancer, in particularly those involving the brain, requires astute clinical judgement. Decision-making can be improved by understanding baseline functional status, cancer prognosis and expected disability from stroke, as well as utilizing diagnostic modalities such acute MRI where needed. While this article does not encourage use of IVT in patients with all malignancies, it lays the groundwork for decision making should thrombolysis be a consideration in a patient with AIS in a cancer patient. 相似文献
57.
Mohammad Akrami Kim Craig Mahdieh Dibaj Akbar A. Javadi Abdelmalek Benattayallah 《Journal of medical engineering & technology》2013,37(7):546-552
AbstractA three-dimensional hip model was created from the MRI scans of one human subject based on constructing the entire pelvis and femur. The ball and socket joint was modelled between the hip’s acetabulum and the femoral head to analyse the multiaxial loads applied in the hip joint. The three key ligaments that reinforce the external surface of the hip to help to stabilise the joint were also modelled which are the iliofemoral, the pubofemoral and ischiofemoral ligaments. Each of these ligaments wraps around the joint connection to form a seal over the synovial membrane, a line of attachment around the head of the femur. This model was tested for different loading and boundary conditions to analyse their sensitivities on the cortical and cancellous tissues of the human hip bones. The outcomes of a one-legged stance finite element analysis revealed that the maximum of 0.056?mm displacement occurred. The stress distribution varied across the model which the majority occurring in the cortical femur and dissipating through the cartilage. The maximum stress value occurring in the joint was 110.1?MPa, which appeared at the free end of the proximal femur. This developed finite element model was validated against the literature data to be used as an asset for further research in investigating new methods of total hip arthroplasty, to minimise the recurrence of dislocations and discomfort in the hip joint, as well as increasing the range of movement available to a patient after surgery. 相似文献
58.
The merits of surgical treatment of fractures of the mandibular condyle versus non-surgical management remains highly controversial, despite a large volume of literature dedicated to this topic. One reason the controversy remains, is because most of the outcomes in the literature are not directly comparable. The disparate range of condylar fracture classifications used is one of the reasons that studies are not comparable. We sought to review classification systems for condylar fractures used in the recent scientific literature.Review of the literature from 2016 to 2019, looking for papers relating to fractures of the mandibular condyle. Papers identified were assessed for type of study, focus of study, classification system used.88 studies were identified, including prospective and retrospective cohort studies, randomised and non-randomised prospective studies, randomised controlled trials and case series. More studies focussed on epidemiological factors than surgical access, fixation or outcomes. 31 used no classification system, whilst 17 used unique classification systems and 40 used previously referenced classification systems.Classification systems are used to help separate clinical problems into distinguishable groups, where there is a difference in management or outcome depending on the distinguishing features.There is currently a wide diversity of classification systems used for condyle fractures, and as a result, comparisons of surgical access, fixation and outcomes are difficult to make. Having a single classification system across the published literature would allow easier comparison and the classification proposed by the AO group is recommended for future use. 相似文献
59.
Numerical and In Vitro Investigation of a Novel Mechanical Circulatory Support Device Installed in the Descending Aorta 下载免费PDF全文
Mohammad Amin Rezaienia Akbar Rahideh Borhan Alhosseini Hamedani Dawid Emanuel Maximilian Bosak Silviya Zustiak Theodosios Korakianitis 《Artificial organs》2015,39(6):502-513
Traditional implantation techniques of assist devices from the apex of left ventricle to the ascending or descending aorta are highly invasive and carry substantial complications for end‐stage heart failure patients. This study has shown that the descending aorta can be a promising location to install an implantable mechanical circulatory support with minimally invasive surgery. Herein, the hemodynamic effect of an in‐house prototyped pump implanted in the descending aorta was investigated numerically as well as experimentally. The objective of the experimental study is met by using the in‐house simulator of the cardiovascular loop replicating congestive heart failure conditions. The objective of the numerical study was met by using the modified version of the concentrated lumped parameter model developed by the same team. The results show that the pump placement in the descending aorta can lead to an improvement in pulsatility. The pressure drop, generated at the upstream of the pump, facilitates the cardiac output as a result of after‐load reduction, but at the same time, it induces a slight drop in the carotid as well as the coronary perfusion. The pressure rise, generated at the downstream of the pump, improves the blood perfusion in the renal circulation. 相似文献
60.
Hematopoietic growth factor expression and ATRA sensitivity in acute promyelocytic blast cells 总被引:1,自引:0,他引:1
Dubois C; Schlageter MH; de Gentile A; Guidez F; Balitrand N; Toubert ME; Krawice I; Fenaux P; Castaigne S; Najean Y 《Blood》1994,83(11):3264-3270
Acute promyelocytic leukemia (APL) is a homogeneous subgroup of acute myeloid leukemias (AMLs) characterized by the presence of the t(15,17) translocation and the resulting promyelocytic myeloid leukemia/retinoic acid receptor alpha (PML/RAR alpha) fusion proteins. To date APL is the only AML that is sufficiently sensitive to all-trans retinoic acid's (ATRA) differentiating effect. In vivo ATRA alone achieves complete remission in most APL patients. However, failure or partial responses are observed and the molecular basis of the absence of ATRA response in these patients has not been determined. To gain insights in the cell growth and differentiation of APL cells, expression of hematopoietic growth factors (HGF) shown to be produced by leukemic cells (interleukin-1 beta [IL-1 beta], IL-6, tumor necrosis factor alpha (TNF alpha), granulocyte colony-stimulating factor [G-CSF], granulocyte- macrophage colony-stimulating factor [GM-CSF], and IL-3) was studied in 16 APL samples. Twelve APL cases expressed IL-1 beta, IL-6, and TNF alpha, but not G-CSF, GM-CSF, and IL-3. These cases achieved complete remission with ATRA therapy. The four remaining patients (either TNF alpha negative or G-CSF, GM-CSF or IL-3 positive) did not achieve complete remission with ATRA. In all cases, in vivo response to ATRA therapy was correlated to the in vitro differentiation effect of all- trans retinoic acid 10(-6) mol/L. Thus, ATRA differentiation induction was strongly correlated to the HGF expression (P < .0001). These results suggest that the presence or absence of HGF's expression by APL cells may contribute to the therapeutic effect of ATRA in this disease. 相似文献