全文获取类型
收费全文 | 18006篇 |
免费 | 1736篇 |
国内免费 | 52篇 |
专业分类
耳鼻咽喉 | 227篇 |
儿科学 | 698篇 |
妇产科学 | 449篇 |
基础医学 | 2220篇 |
口腔科学 | 224篇 |
临床医学 | 2594篇 |
内科学 | 3539篇 |
皮肤病学 | 217篇 |
神经病学 | 1762篇 |
特种医学 | 352篇 |
外科学 | 1834篇 |
综合类 | 246篇 |
一般理论 | 16篇 |
预防医学 | 2329篇 |
眼科学 | 424篇 |
药学 | 1105篇 |
中国医学 | 44篇 |
肿瘤学 | 1514篇 |
出版年
2024年 | 16篇 |
2023年 | 151篇 |
2022年 | 238篇 |
2021年 | 635篇 |
2020年 | 436篇 |
2019年 | 732篇 |
2018年 | 710篇 |
2017年 | 560篇 |
2016年 | 587篇 |
2015年 | 638篇 |
2014年 | 822篇 |
2013年 | 1138篇 |
2012年 | 1410篇 |
2011年 | 1531篇 |
2010年 | 897篇 |
2009年 | 734篇 |
2008年 | 1170篇 |
2007年 | 1178篇 |
2006年 | 1115篇 |
2005年 | 1003篇 |
2004年 | 886篇 |
2003年 | 867篇 |
2002年 | 750篇 |
2001年 | 113篇 |
2000年 | 92篇 |
1999年 | 106篇 |
1998年 | 147篇 |
1997年 | 108篇 |
1996年 | 83篇 |
1995年 | 85篇 |
1994年 | 80篇 |
1993年 | 62篇 |
1992年 | 68篇 |
1991年 | 63篇 |
1990年 | 45篇 |
1989年 | 46篇 |
1988年 | 48篇 |
1987年 | 37篇 |
1986年 | 29篇 |
1985年 | 36篇 |
1984年 | 36篇 |
1983年 | 25篇 |
1982年 | 32篇 |
1981年 | 34篇 |
1980年 | 35篇 |
1979年 | 18篇 |
1977年 | 16篇 |
1976年 | 15篇 |
1974年 | 15篇 |
1972年 | 14篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Kathryn E Merkel Karen L Schmidt Rachel M Levenstein Jessie M VanSwearingen Barbara C Bentley 《Otolaryngology--head and neck surgery》2007,137(1):100-104
OBJECTIVES: Positive affect in individuals with a facial movement disorder may promote lip corner movement (zygomaticus major) during smiling. We investigated whether a positive affect marker (orbicularis oculi activity) observed in an initial clinic visit of individuals with facial movement disorder (N = 28) predicted increased lip corner movement at a subsequent visit. STUDY DESIGN AND SETTING: In this clinical outcomes study, lip corner movement was assessed with the use of automated facial analysis. Asymmetry of movement was compared in individuals who smiled with or without the positive affect marker at an initial clinic visit. RESULTS: The positive affect marker at the initial visit was associated with a reduction in the asymmetry of the lip corner movement at the second visit. CONCLUSION: Positive affect predicts improved facial movement outcomes in patients with facial movement disorders. SIGNIFICANCE: Positive emotion in facial movement patients may be an important factor in recovery of facial movement during therapy. 相似文献
82.
Robin M Carter-Visscher Amy E Naugle Kathryn M Bell Michael K Suvak 《Journal of trauma & dissociation》2007,8(3):27-55
This study examined ethical concerns related to exposing participants with childhood victimization histories to both trauma-specific and non-trauma-specific stimuli. We asked participants questions about childhood victimization experiences and exposed participants to a negatively-arousing experimental condition. Following each of these procedures and at a one-week follow-up session, participants completed a measure designed to asses their reactions to participation. The measure included several questions to assess reactions including questions about distress, benefit, and willingness to participate in the study again. Overall, participants reported low levels of distress and described their participation experience as interesting, enjoyable, and somewhat beneficial. Participants also indicated that they would be willing to participate in the study again with the knowledge of what participation was actually like. Participants with childhood trauma histories and PTSD symptoms reported more distress during the childhood maltreatment screening compared to other participants. However, the level of distress they experienced was mild and transitory. Our findings add to the emerging data indicating that individuals find their participation in trauma-related research to be a positive experience overall, rather than a harmful one. 相似文献
83.
Novel Mechanisms of Antiprogestin Action 总被引:10,自引:0,他引:10
Kathryn B. Horwitz 《Acta oncologica (Stockholm, Sweden)》1996,35(2):129-140
84.
Carol Smillie B.N. B.Ed. M.S.C. Katherine Coffin B.A. ME.D. Kathryn Porter B.A. Brenda Ryan B.A. M.B.A. 《Journal of community health》1988,13(3):156-170
The International Conference on Primary Health Care, meeting in Alma-Ata, in the Soviet Union, September 12, 1978, expressed the need for urgent action by all governments, all health and development workers and the world community, to protect and promote the health of all people of the world. The world was caught by the phrase which emerged from this conference, Health For All by the Year 2000 and many have examined the articles of the Alma-Ata declaration and tried to implement them in their corner of the world. This paper describes a community-based smoking-cessation program which was implemented in the province of Nova Scotia, Canada, during the years 1980–1984. Primary to this project was the belief that people have the right and the duty to participate individually and collectively in planning and implementing their health care. This paper describes one community's effort in putting this belief into practice.Carol Smillie, B.N. BE.d. M.S.c. is an Assistant Professor at the School of Nursing, Dalhousie University, Halifax, Nova Scotia, Canada B3H 3J5, Katherine Coffin, BA, MEd is the Program Officer, Nova Scotia Office, Health Promotion Directorate Health and Welfare Canada, 5251 Duke Street, Halifax, Nova Scotia. Canada B3J 1P3. Kathryn Porter, B.A. (Gen)., is the Information and Education Coordinator, Nova Scotia Division Canadian Cancer Society. Brenda Ryan, B.A., M.B.A. is Program Evaluation Analysist, Nova Scotia Department of Health, 6088 Hollis Street, Halifax. Nova Scotia, Canada. This Project was funded by Health and Welfare Canada, Nova Scotia Department of Health, Nova Scotia Division Canadian Cancer Society, Requests for reprints should be addressed to: Professor Carol Smillie. 相似文献
85.
Scrub typhus vaccine candidate Kp r56 induces humoral and cellular immune responses in cynomolgus monkeys
下载免费PDF全文
![点击此处可从《Infection and immunity》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Chattopadhyay S Jiang J Chan TC Manetz TS Chao CC Ching WM Richards AL 《Infection and immunity》2005,73(8):5039-5047
A truncated recombinant 56-kDa outer membrane protein of the Karp strain of Orientia tsutsugamushi (Kp r56) was evaluated in cynomolgus monkeys (Macaca fascicularis) for immunogenicity and safety as a vaccine candidate for the prevention of scrub typhus. This recombinant antigen induced strong humoral and cellular immune responses in two monkeys and was found to be well tolerated. Antigen-specific immunoglobulin M (IgM) and IgG were produced to almost maximal levels within 1 week of a single immunization. Peripheral blood mononuclear cells from vaccinated animals showed an induction of antigen-specific proliferation and gamma interferon production. The Kp r56 was not as efficient as infection with live organisms in preventing reinfection but was able to reduce the inflammation produced at the site of challenge. This report describes the results of the first systematic study of the immunogenicity of a recombinant scrub typhus vaccine candidate in a nonhuman primate model. 相似文献
86.
Karen W. Gripp Lindsey A. Morse Marni Axelrad Kathryn C. Chatfield Aaron Chidekel William Dobyns Daniel Doyle Bronwyn Kerr Angela E. Lin David D. Schwartz Barbara J. Sibbles Dawn Siegel Suma P. Shankar David A. Stevenson Mihir M. Thacker K. Nicole Weaver Sue M. White Katherine A. Rauen 《American journal of medical genetics. Part A》2019,179(9):1725-1744
Costello syndrome (CS) is a RASopathy caused by activating germline mutations in HRAS. Due to ubiquitous HRAS gene expression, CS affects multiple organ systems and individuals are predisposed to cancer. Individuals with CS may have distinctive craniofacial features, cardiac anomalies, growth and developmental delays, as well as dermatological, orthopedic, ocular, and neurological issues; however, considerable overlap with other RASopathies exists. Medical evaluation requires an understanding of the multifaceted phenotype. Subspecialists may have limited experience in caring for these individuals because of the rarity of CS. Furthermore, the phenotypic presentation may vary with the underlying genotype. These guidelines were developed by an interdisciplinary team of experts in order to encourage timely health care practices and provide medical management guidelines for the primary and specialty care provider, as well as for the families and affected individuals across their lifespan. These guidelines are based on expert opinion and do not represent evidence‐based guidelines due to the lack of data for this rare condition. 相似文献
87.
Napolitano LA Burt TD Bacchetti P Barrón Y French AL Kovacs A Anastos K Young M McCune JM Greenblatt RM 《Journal of acquired immune deficiency syndromes (1999)》2005,40(5):581-584
Sex-based differences in CD4 T-cell (CD4) counts are well recognized, but the basis for these differences has not been identified. Conceivably, homeostatic factors may play a role in this process by regulating T-cell maintenance and repletion. Interleukin (IL)-7 is essential for normal T-cell production and homeostasis. We hypothesized that differences in IL-7 might contribute to sex-based differences in CD4 counts. Circulating IL-7 levels were analyzed in 299 HIV-1-infected women and men. Regression analysis estimated that IL-7 levels were 40% higher in women than in men (P = 0.0032) after controlling for CD4 count, age, and race. Given the important role of IL-7 in T-cell development and homeostasis, these findings suggest that higher IL-7 levels may contribute to higher CD4 counts in women. 相似文献
88.
Jun Kai Kao Yin Tzu Hsue Ching Yuang Lin 《Journal of microbiology, immunology, and infection》2007,40(5):419-427
BACKGROUND AND PURPOSE: Rheumatoid arthritis (RA) is a CD4(+)-dependent chronic systemic inflammatory disease with autoimmune features. Autoreactive CD4(+) T-cell activation can result in autoimmune diseases. One of the key regulators is the CD4(+)CD25(high) regulatory T (Treg) cell. In an animal arthritis model, CD11c(+)CD8(+) T cells were found to be elevated, and could suppress pathogenic CD4(+) T cells after cross-linking with CD137. The purpose of this study was to compare the expression of CD137, CD4(+)CD25(high) Treg cells, and CD11c(+)CD8(+) in the peripheral blood T lymphocytes of RA patients during active and remissive states, and evaluate the correlation with disease activity. METHODS: Thirty nine RA patients treated at the rheumatology outpatient clinic at the Changhua Christian Hospital were assessed clinically for disease activity and classified as either highly active or remissive by the Disease Activity Score 28. Peripheral blood mononuclear cells were isolated from these patients and compared against normal controls. RESULTS: The presence of CD11c(+)CD8(+) T cells or the expression of CD137 molecules in peripheral blood cells was not related to disease activity. In contrast, CD4(+)CD25(high) Treg cell levels were increased significantly in patients with active RA compared with patients with remissive RA or controls (p<0.05). These lymphocytes were intact, without evidence of apoptosis. CONCLUSIONS: Our results indicate that CD4(+)CD25(high) Treg cells play an important role in modulating RA disease activity and can serve as a parameter of disease activity. 相似文献
89.
Summary Neural crest cells are motile and mitotic, whereas their neuronal derivatives are terminally post-mitotic and consist of stationary cell body from which processes grow. The present study documents changes in the cytoskeleton that occur during neurogenesis in cultures of avian neural crest cells. The undifferentiated neural crest cells contain dense bundles of actin filaments throughout their cytoplasm, and a splayed array of microtubules attached to the centrosome. In newly differentiating neurons, the actin bundles are disrupted and most of the remaining actin filaments are reorganized into a cortical layer underlying the plasma membrane of the cell body and processes. Microtubules are more abundant in newly-differentiating neurons than in the undifferentiated cells, and individual microtubules can be seen dissociated from the centrosome. Neuron-specific -III tubulin appears in some crest cells prior to cessation of motility and cell division, and expression increases with total microtubule levels during neurogenesis. To investigate how these early cytoskeletal changes might contribute to alterations in morphology during neurogenesis, we have disrupted the cytoskeleton with pharmacologic agents. Microfilament disruption by cytochalasin immediately arrests the movement of neural crest cells and causes them to round-up, but does not significantly change the morphology of the immature neurons. Microtubule depolymerization by nocodazole slows the movement of undifferentiated cells and causes retraction of processes extended by the immature neurons. These results suggest that changes in the actin and microtubule arrays within neural crest cells govern distinct aspects of their morphogenesis into neurons. 相似文献
90.
Bojian Zheng Ming-Liang He King-Ling Wong Ching Tung Lum Leo L M Poon Ying Peng Yi Guan Marie C M Lin Hsiang-Fu Kung 《Journal of interferon & cytokine research》2004,24(7):388-390
We sought to investigate the anti-severe acute respiratory syndrome (SARS)-associated coronavirus (SCoV) activities of type I (alpha and beta) and type II (gamma) interferons (IFN) in vitro. Type I IFNs protected cells from cytopathic effects (CPE) induced by SCoV, and inhibited viral genomic RNA replication in FRhk-4 cells (measured by quantitative RT-PCR) in a dose-dependent manner. Intracellular viral RNA copies were reduced 50% by IFN-alpha at a concentration of 25 U/ml and by IFN-beta at a concentration of 14 U/ml. IFN-gamma had fewer effects on inhibition of viral infection and replication. The type I IFN receptor signaling pathway in host cells is mainly involved in the inhibition of SCoV infection and replication. Type I IFNs could be used as potential agents for anti-SARS treatment. 相似文献