全文获取类型
收费全文 | 5076篇 |
免费 | 318篇 |
国内免费 | 18篇 |
专业分类
耳鼻咽喉 | 42篇 |
儿科学 | 119篇 |
妇产科学 | 84篇 |
基础医学 | 944篇 |
口腔科学 | 93篇 |
临床医学 | 517篇 |
内科学 | 1057篇 |
皮肤病学 | 184篇 |
神经病学 | 575篇 |
特种医学 | 220篇 |
外科学 | 422篇 |
综合类 | 35篇 |
一般理论 | 3篇 |
预防医学 | 336篇 |
眼科学 | 62篇 |
药学 | 349篇 |
中国医学 | 8篇 |
肿瘤学 | 362篇 |
出版年
2023年 | 26篇 |
2022年 | 53篇 |
2021年 | 118篇 |
2020年 | 70篇 |
2019年 | 83篇 |
2018年 | 91篇 |
2017年 | 79篇 |
2016年 | 98篇 |
2015年 | 175篇 |
2014年 | 184篇 |
2013年 | 210篇 |
2012年 | 370篇 |
2011年 | 421篇 |
2010年 | 234篇 |
2009年 | 212篇 |
2008年 | 386篇 |
2007年 | 417篇 |
2006年 | 336篇 |
2005年 | 375篇 |
2004年 | 315篇 |
2003年 | 318篇 |
2002年 | 280篇 |
2001年 | 38篇 |
2000年 | 21篇 |
1999年 | 44篇 |
1998年 | 71篇 |
1997年 | 58篇 |
1996年 | 42篇 |
1995年 | 41篇 |
1994年 | 34篇 |
1993年 | 24篇 |
1992年 | 18篇 |
1991年 | 17篇 |
1990年 | 14篇 |
1989年 | 7篇 |
1988年 | 11篇 |
1987年 | 10篇 |
1986年 | 11篇 |
1985年 | 11篇 |
1984年 | 12篇 |
1983年 | 10篇 |
1982年 | 7篇 |
1981年 | 10篇 |
1980年 | 9篇 |
1979年 | 6篇 |
1978年 | 4篇 |
1977年 | 5篇 |
1975年 | 5篇 |
1973年 | 3篇 |
1972年 | 3篇 |
排序方式: 共有5412条查询结果,搜索用时 15 毫秒
101.
Ségolène Billot Dominique Hervé Hasan O. Akman Roseline Froissart Christiane Baussan Kristl G. Claeys Monique Piraud Frédéric Sedel Fanny Mochel Pascal Laforêt 《Journal of the neurological sciences》2013,324(1-2):179-182
Adult polyglucosan body disease (APBD) is a metabolic disorder usually caused by glycogen branching enzyme (GBE) deficiency. APBD associates progressive walking difficulties, bladder dysfunction and, in about 50% of the cases, cognitive decline. APBD is characterized by a recognizable leukodystrophy on brain MRI. We report here a novel presentation of this disease in a 35-year old woman who presented with an acute deterioration followed by an unexpected recovery. Enzymatic analysis displayed decreased GBE activity in leukocytes. Molecular analyses revealed that only one mutated allele was expressed, bearing a p.Arg515His mutation. This is the first observation reporting acute and reversible neurological symptoms in APBD. These findings emphasize the importance of searching GBE deficiency in patients presenting with a leukodystrophy and acute neurological symptoms mimicking a stroke, in the absence of cardiovascular risk factors. 相似文献
102.
Multiple sclerosis (MS) is the most common inflammatory demyelinating disease of the central nervous system. Traditionally, demyelinating lesions in the white matter have been regarded as the most important pathological feature in MS, but recent pathological and imaging studies confirmed substantial changes in grey matter and normal-appearing white matter. MS lesions are characterized by inflammation, demyelination, axonal damage and astrogliosis. During early MS lesion formation acute axonal injury is extensive and correlates with inflammation. In addition to focal lesions, diffuse wide-spread changes including neuroaxonal degeneration and compartmentalized inflammation are likely to contribute to increasing disability in progressive MS. Neuromyelitis optica (NMO) is classically characterized by severe transverse myelitis and optic neuritis, but brain lesions are also present in the majority of NMO patients. The discovery of the NMO-specific antibody demonstrated that NMO is a disease entity distinct from MS. This antibody binds to aquaporin-4 expressed in astrocytes and ependymal cells. NMO lesions are characterized by inflammation, demyelination, axonal damage and a marked loss of aquaporin-4. Early NMO lesions demonstrate a pronounced humoral inflammatory response and astrocytic cell death with loss of aquaporin-4, followed by inflammatory demyelination and axonal damage. These recent findings contribute to a better understanding of different mechanisms leading to inflammatory demyelination. 相似文献
103.
104.
105.
106.
107.
Breloer M Kretschmer B Lüthje K Ehrlich S Ritter U Bickert T Steeg C Fillatreau S Hoehlig K Lampropoulou V Fleischer B 《European journal of immunology》2007,37(3):634-648
The transmembrane glycoprotein CD83 has been described as a specific maturation marker for dendritic cells and several lines of evidence suggest that CD83 regulates thymic T cell maturation as well as peripheral T cell activation. Here we show for the first time that CD83 is involved also in the regulation of B cell function. CD83 is up-regulated on activated B cells in vivo, specifically in the draining lymph nodes of Leishmania major-infected mice. The ubiquitous transgenic (Tg) expression of CD83 interferes with Leishmania-specific T cell-dependent and with T cell-independent antibody production. This defect is restricted to the B cell population since the antigen-specific T cell response of CD83Tg mice to L. major infection is unchanged. The defective immunoglobulin (Ig) response is due to Tg expression of CD83 on the B cells because wild-type B cells display normal antigen-specific responses in CD83Tg hosts and CD83Tg B cells do not respond to immunization in a mixed wild-type/CD83Tg bone marrow chimera. Finally, the treatment of non-Tg C57BL/6 mice with anti-CD83 mAb induces a dramatic increase in the antigen-specific IgG response to immunization, thus demonstrating a regulatory role for naturally induced CD83 on wild-type B cells. 相似文献
108.
Katrin Christiane Reber Hans-Helmut König André Hajek 《Journal of occupational medicine and toxicology (London, England)》2018,13(1):33
Background
So far, studies within the occupational field have largely concentrated on working conditions and job stressors and staff members’ or subordinate health. Only a few have focused on managers in this context, but studies are missing that explicitly look at the relation between leadership position and health care use (HCU). Thus, the purpose of this study was to examine the potential effects of a change in leadership position on HCU in women and men longitudinally.Methods
Data were drawn from a nationally representative longitudinal study in Germany (German Socio-Economic Panel, GSOEP). Data from 2009 and 2013 were used. Leadership position was divided into (i) top management, (ii) middle management, (iii) lower management, and (iv) a highly qualified specialist position. The number of physician visits in the preceding 3 months were used to quantify HCU (n?=?2140 observations in regression analysis; 69% male).Results
Adjusting for various potential confounders (e.g., age, self-rated health, chronic conditions, and personality factors), Poisson FE regression analysis revealed that changes from a highly qualified specialist position to the top management were associated with a decrease in the number of physician visits in men (β?=?.47, p?<?.05), but not in women. Gender differences (gender x leadership position) were significant.Conclusions
Findings of this study emphasize the impact of leadership positions on the number of physician visits in men. Further study is required to elucidate the underlying mechanisms.109.
Nicolas Cabanel Christiane Bouchier Minoarisoa Rajerison Elisabeth Carniel 《International journal of antimicrobial agents》2018,51(2):249-254
The emergence of antibiotic-resistant Yersinia pestis strains represents a public health concern. Two antibiotic-resistant Y. pestis strains isolated from Madagascar have been previously identified and characterised. Both strains carried conjugative plasmids that conferred resistance to streptomycin or to multiple antibacterial drugs, respectively. Here we characterised a novel Y. pestis strain (IP2180H) that exhibited resistance to doxycycline. This strain was isolated from a rat in Antananarivo (Madagascar) in 1998. Resistance was carried by a conjugative plasmid (pIP2180H) homologous to pB71 from Salmonella enterica. The plasmid of the previously identified streptomycin-resistant Y. pestis strain was also sequenced and it was found that the three antibiotic resistance Y. pestis plasmids sequenced until now are genetically unrelated and are also unrelated to multidrug resistance plasmids from the phylogenetically close bacterial species Yersinia pseudotuberculosis. The fact that the three antibiotic-resistant Malagasy Y. pestis strains were isolated from different hosts, at different times, from distant locations, and carried unrelated plasmids indicates independent horizontal acquisition of genetic material and further demonstrates the capacity of Y. pestis to acquire antibiotic resistance plasmids under natural conditions. Since these resistance plasmids can frequently carry or easily trap antibiotic resistance cassettes, the emergence of new multidrug-resistant Y. pestis strains may be expected and would represent a major health threat. 相似文献
110.
Evidence-based intervention programs have become highly important in recent years, especially in educational contexts. However, transferring these programs into practice and into the wider field of public policy often fails. As a consequence, the field of implementation research has emerged, several implementation frameworks have been developed, and implementation studies conducted. However, intervention research and implementation research have not yet been connected systematically and different traditions and research groups are involved. Implementation researchers are mostly given mandates by politicians to take on the implementation of already existing interventions. This might be one of the key reasons why there are still many problems in translating programs into widespread community practice. In this paper, we argue for a systematic integration of intervention and implementation research (“I3-Approach”) and recommend a six-step procedure (PASCIT). This requires researchers to design and develop intervention programs using a field-oriented and participative approach. In particular, the perspective of policymakers has to be included as well as an analysis of which factors support or hinder evidence-based policy in contrast to opinion-based policy. How this systematic connection between intervention and implementation research can be realized, is illustrated by means of the development and implementation of the ViSC school program, which intends to reduce aggressive behavior and bullying and to foster social and intercultural competencies. 相似文献