全文获取类型
收费全文 | 20703篇 |
免费 | 1278篇 |
国内免费 | 30篇 |
专业分类
耳鼻咽喉 | 205篇 |
儿科学 | 734篇 |
妇产科学 | 612篇 |
基础医学 | 2498篇 |
口腔科学 | 174篇 |
临床医学 | 3960篇 |
内科学 | 3519篇 |
皮肤病学 | 361篇 |
神经病学 | 1814篇 |
特种医学 | 336篇 |
外科学 | 1772篇 |
综合类 | 173篇 |
一般理论 | 34篇 |
预防医学 | 2777篇 |
眼科学 | 197篇 |
药学 | 1333篇 |
3篇 | |
中国医学 | 7篇 |
肿瘤学 | 1502篇 |
出版年
2024年 | 41篇 |
2023年 | 138篇 |
2022年 | 187篇 |
2021年 | 441篇 |
2020年 | 297篇 |
2019年 | 437篇 |
2018年 | 529篇 |
2017年 | 436篇 |
2016年 | 451篇 |
2015年 | 500篇 |
2014年 | 668篇 |
2013年 | 1003篇 |
2012年 | 1517篇 |
2011年 | 1517篇 |
2010年 | 847篇 |
2009年 | 768篇 |
2008年 | 1393篇 |
2007年 | 1529篇 |
2006年 | 1480篇 |
2005年 | 1390篇 |
2004年 | 1362篇 |
2003年 | 1246篇 |
2002年 | 1161篇 |
2001年 | 173篇 |
2000年 | 104篇 |
1999年 | 157篇 |
1998年 | 236篇 |
1997年 | 187篇 |
1996年 | 184篇 |
1995年 | 159篇 |
1994年 | 160篇 |
1993年 | 118篇 |
1992年 | 82篇 |
1991年 | 76篇 |
1990年 | 77篇 |
1989年 | 56篇 |
1988年 | 76篇 |
1987年 | 60篇 |
1986年 | 67篇 |
1985年 | 59篇 |
1984年 | 61篇 |
1983年 | 45篇 |
1982年 | 67篇 |
1981年 | 72篇 |
1980年 | 64篇 |
1979年 | 33篇 |
1978年 | 40篇 |
1977年 | 31篇 |
1974年 | 23篇 |
1973年 | 25篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
21.
Pascal Derkinderen MD PhD Kathleen M Shannon MD Patrik Brundin MD PhD 《Movement disorders》2014,29(8):976-979
Strong epidemiologic evidence suggests that smokers and coffee drinkers have a lower risk of Parkinson's disease (PD). The explanation for this finding is still unknown, and the discussion has focused on two main hypotheses. The first suggests that PD patients have premorbid personality traits associated with dislike for coffee‐drinking and smoking. The second posits that caffeine and nicotine are neuroprotective. We propose an alternative third hypothesis, in which both cigarette and coffee consumption change the composition of the microbiota in the gut in a way that mitigates intestinal inflammation. This, in turn, would lead to less misfolding of the protein alpha‐synuclein in enteric nerves, reducing the risk of PD by minimizing propagation of the protein aggregates to the central nervous system, where they otherwise can induce neurodegeneration. © 2014 International Parkinson and Movement Disorder Society 相似文献
22.
23.
24.
John S. Hwang Anokhi D. Mehta Richard S. Yoon Kathleen S. Beebe 《Journal of orthopaedics and traumatology》2014,15(2):81-86
In 1943, Austin Moore developed the first endoprosthesis fashioned from Vitallium, providing the first alternative to traditional amputation as primary treatment of bone tumors. The success of the Vitallium endoprosthesis has since then led to the development of new materials and designs further advancing limb salvage and reconstructive surgery. Combined with the advent of chemotherapy use and imaging advances, conservative treatment of musculoskeletal tumors has expanded greatly. As the implantable options increased with the development of the Lewis expandable adjustable prosthesis and the noninvasive Phenix Growing prosthesis, receiving the diagnosis of a bone tumor no longer equates to automatic limb loss. Our review details the history and development of endoprostheses throughout orthopedic oncology in the treatment of musculoskeletal tumors. 相似文献
25.
26.
27.
Anai S Goodison S Shiverick K Hirao Y Brown BD Rosser CJ 《Molecular cancer therapeutics》2007,6(1):101-111
Expression of the proto-oncogene Bcl-2 is associated with tumor progression. Bcl-2's broad expression in tumors, coupled with its role in resistance to chemotherapy and radiation therapy-induced apoptosis, makes it a rational target for anticancer therapy. Antisense Bcl-2 oligodeoxynucleotide (ODN) reagents have been shown to be effective in reducing Bcl-2 expression in a number of systems. We investigated whether treating human prostate cancer cells with antisense Bcl-2 ODN (G3139, oblimersen sodium, Genasense) before irradiation would render them more susceptible to radiation effects. Two prostate cancer cell lines expressing Bcl-2 at different levels (PC-3-Bcl-2 and PC-3-Neo) were subjected to antisense Bcl-2 ODN, reverse control (CTL), or mock treatment. Antisense Bcl-2 ODN alone produced no cytotoxic effects and was associated with G(1) cell cycle arrest. The combination of antisense Bcl-2 ODN with irradiation sensitized both cell lines to the killing effects of radiation. Both PC-3-Bcl-2 and PC-3-Neo xenografts in mice treated with the combination of antisense Bcl-2 ODN and irradiation were more than three times smaller by volume compared with xenografts in mice treated with reverse CTL alone, antisense Bcl-2 ODN alone, irradiation alone, or reverse CTL plus radiotherapy (P = 0.0001). Specifically, PC-3-Bcl-2 xenograft tumors treated with antisense Bcl-2 ODN and irradiation had increased rates of apoptosis and decreased rates of angiogenesis and proliferation. PC-3-Neo xenograft tumors had decreased proliferation only. This is the first study which shows that therapy directed at Bcl-2 affects tumor vasculature. Together, these findings warrant further study of this novel combination of Bcl-2 reduction and radiation therapy, as well as Bcl-2 reduction and angiogenic therapy. 相似文献
28.
Graça Cardadeiro Fátima Baptista Kathleen F. Janz Luís A. Rodrigues Luís B. Sardinha 《Journal of bone and mineral metabolism》2014,32(2):174-183
Differences in skeletal geometry may generate different patterns of mechanical loading to bone. Impact and muscle loading during physical activity have been shown to influence skeletal geometry. The purpose of this study was to compare geometric measures of the pelvis and proximal femur (PF) of young children and to analyze the contribution and potential interaction of these geometric measures with physical activity on PF bone mass distribution. Participants were 149 girls and 145 boys, aged 10–11 years. Total body and left hip DXA scans were used to derive pelvic and PF geometric measures and PF bone mineral density (BMD) at the femoral neck (FN), trochanter (TR), and intertrochanter (IT). These subregions were used to represent bone mass distribution via three BMD ratios: FN:PF, TR:PF, and IT:PF. Physical activity was objectively measured using accelerometry, and maturity was estimated as the years of distance from peak height velocity. When compared to boys, girls had a wider pelvic diameter and greater interacetabular distances (p < 0.001), lower BMD at FN, TR, and IT (p < 0.05), and higher TR:PF (p < 0.001). After controlling for maturity, body height, and lean body mass, the interacetabular distance in girls explained 21.1 % (β = 0.713, p < 0.001) in TR:PF and 2.9 % (β = ?0.179, p = 0.031) in the IT:PF. Neck–shaft angle explained 5.6 % (β = ?0.265, p = 0.001) of the IT:PF and 3.1 % (β = 0.194, p = 0.018) of the FN:PF. In boys, FN axis length explained 2.9 % (β = 0.195, p = 0.040) of TR:PF. There was no main effect of physical activity or interaction effect with pelvic geometry in explaining BMD differences among the subregions of the PF. Even before sexual dimorphism, girls have a wider pelvis than boys, which accounted for proportionally greater BMD of the TR than other subregions of the PF. 相似文献
29.
Patusky KL 《International journal of older people nursing》2007,2(3):171-179
Aims and objectives. The proposed model of event-generated dependence characterizes dependence in older adults as an emergent phenomenon that may arise from interaction between the older adult with compromised health and the social environment, resulting in altered reciprocity.
Background. Pejorative characterizations of dependence in older adults influence nursing care negatively. Concept analyses recommend the recognition that dependence is interactive in nature, not an inherent trait of the individual, and that dependence involves changes in interpersonal reciprocity.
Conclusions. The model provides a testable causal path between dependence and psychological outcomes.
Relevance to clinical practice. The event generated dependence model can sensitize nurses to an alternative view of dependence. It is important for nurses to recognize their role in determining the social environment of care, attend to the promotion of reciprocity with older adults as care is provided, and incorporate changes in their attitudes toward inequitable reciprocity. 相似文献
Background. Pejorative characterizations of dependence in older adults influence nursing care negatively. Concept analyses recommend the recognition that dependence is interactive in nature, not an inherent trait of the individual, and that dependence involves changes in interpersonal reciprocity.
Conclusions. The model provides a testable causal path between dependence and psychological outcomes.
Relevance to clinical practice. The event generated dependence model can sensitize nurses to an alternative view of dependence. It is important for nurses to recognize their role in determining the social environment of care, attend to the promotion of reciprocity with older adults as care is provided, and incorporate changes in their attitudes toward inequitable reciprocity. 相似文献
30.
Kathleen M. Nokes 《Journal of nursing scholarship》1989,21(3):172-175
Many nursing studies on moral reasoning and ethics have used Kohlberg's theory of moral development. The body of knowledge that resulted from these studies indicated that nurses and nursing students had consistently lower than expected levels of moral reasoning. Educational offerings were developed to assist nurses to improve their moral reasoning. This article explores the cognitive-developmental theory of moral development as one way of determining the moral development of nurses. Since this theory of moral reasoning focuses on the rational thought of the individual and does not consider the impact of the environment, it is of limited applicability in nursing. A new theory of morality needs to be developed—a more holistic one that will include both universal principles and contextual issues. 相似文献