全文获取类型
收费全文 | 40417篇 |
免费 | 2636篇 |
国内免费 | 97篇 |
专业分类
耳鼻咽喉 | 464篇 |
儿科学 | 1461篇 |
妇产科学 | 978篇 |
基础医学 | 5047篇 |
口腔科学 | 623篇 |
临床医学 | 6597篇 |
内科学 | 7106篇 |
皮肤病学 | 418篇 |
神经病学 | 3796篇 |
特种医学 | 836篇 |
外国民族医学 | 1篇 |
外科学 | 3768篇 |
综合类 | 368篇 |
一般理论 | 49篇 |
预防医学 | 5637篇 |
眼科学 | 420篇 |
药学 | 2470篇 |
中国医学 | 44篇 |
肿瘤学 | 3067篇 |
出版年
2024年 | 33篇 |
2023年 | 331篇 |
2022年 | 455篇 |
2021年 | 862篇 |
2020年 | 619篇 |
2019年 | 958篇 |
2018年 | 1116篇 |
2017年 | 835篇 |
2016年 | 871篇 |
2015年 | 964篇 |
2014年 | 1358篇 |
2013年 | 2149篇 |
2012年 | 3106篇 |
2011年 | 3288篇 |
2010年 | 1744篇 |
2009年 | 1584篇 |
2008年 | 2869篇 |
2007年 | 2856篇 |
2006年 | 2798篇 |
2005年 | 2761篇 |
2004年 | 2535篇 |
2003年 | 2257篇 |
2002年 | 2160篇 |
2001年 | 287篇 |
2000年 | 233篇 |
1999年 | 323篇 |
1998年 | 455篇 |
1997年 | 359篇 |
1996年 | 276篇 |
1995年 | 223篇 |
1994年 | 223篇 |
1993年 | 220篇 |
1992年 | 177篇 |
1991年 | 150篇 |
1990年 | 139篇 |
1989年 | 147篇 |
1988年 | 129篇 |
1987年 | 123篇 |
1986年 | 122篇 |
1985年 | 104篇 |
1984年 | 129篇 |
1983年 | 92篇 |
1982年 | 98篇 |
1981年 | 112篇 |
1980年 | 76篇 |
1979年 | 85篇 |
1978年 | 52篇 |
1977年 | 50篇 |
1976年 | 33篇 |
1975年 | 45篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
Miriam Stewart Linda Reutter Edward Makwarimba Irving Rootman Deanna Williamson Kim Raine Doug Wilson Janet Fast Rhonda Love Sharon McFall Deana Shorten Nicole Letourneau Karen Hayward Jeff Masuda William Rutakumwa 《Revue canadienne de recherche en sciences infirmières》2005,37(3):104-131
Poverty influences health status, life expectancy, health behaviours, and use of health services. This study examined factors influencing the use of health-related services by people living in poverty. In the first phase, 199 impoverished users of health-related services in 2 large Canadian cities were interviewed by their peers. In the second phase, group interviews with people living in poverty (n = 52) were conducted. Data were analyzed using thematic content analysis. Diverse health-related services were used to meet basic and health needs, to maintain human contact, and to cope with life's challenges. Use of services depended on proximity, affordability, convenience, information, and providers' attitudes and behaviours. Use was impeded by inequities based on income status. To promote the health of people living in poverty, nurses and other health professionals can enhance the accessibility and quality of services, improve their interactions with people living in poverty, provide information about available programs, offer coordinated community-based services, collaborate with other sectors, and advocate for more equitable services and policies. 相似文献
23.
Dorit Naot Usha Bava Brya Matthews Karen E Callon Gregory D Gamble Michael Black Sarah Song Rocco P Pitto Tim Cundy Jill Cornish Ian R Reid 《Journal of bone and mineral research》2007,22(2):298-309
Paget's disease is a focal condition of bone. To study changes in cells within pagetic lesions, we cultured osteoblasts and stromal cells from 22 patients and compared gene expression in these cells to cells from healthy bone. We identified several differentially regulated genes, and we suggest that these changes could lead to the formation of the lesions. INTRODUCTION: Paget's disease is a focal condition of bone of unknown cause. Although it is regarded as primarily an osteoclast disorder, the tight coupling of the activity of osteoclasts and osteoblasts suggests that the osteoblast could play a key role in its pathogenesis. The aim of the study was to identify possible changes in pagetic osteoblasts and stromal cells that might contribute to the development of pagetic lesions. MATERIALS AND METHODS: Candidate genes were identified based on known bone cell regulators, supplemented with microarray analysis. Gene expression was determined by real-time PCR in primary cultures of osteoblasts and bone marrow stromal cells from pagetic patients and control subjects. Concentrations of secreted proteins were determined by ELISA. RESULTS: Dickkopf1 mRNA and protein levels were increased in both pagetic osteoblast and stromal cell cultures, and interleukin (IL)-1 and IL-6 were overexpressed in pagetic osteoblasts. These changes parallel recent findings in myeloma bone disease, which shares some clinical similarities with Paget's disease. Alkaline phosphatase was overexpressed, and bone sialoprotein and osteocalcin were underexpressed in pagetic osteoblasts, consistent with their circulating levels in pagetic patients. It is hypothesized that overexpression of Dickkopf1, IL-1, and IL-6 would result in stimulation of osteoclast proliferation and inhibition of osteoblast growth, leading to the development of the characteristic lytic bone lesions. By stimulating osteoblast differentiation, Dickkopf1 and IL-6 may also promote mineralization, leading to the conversion of lytic lesions to sclerotic. CONCLUSIONS: These findings suggest that dysregulated gene expression in pagetic osteoblasts could cause the changes in bone cell number and function characteristic of Paget's disease. 相似文献
24.
25.
Karen L Klemme 《Rehabilitation nursing》2003,28(2):40-41
This experience was very well suited to rehabilitation nursing, demanding specialized knowledge and care. Our talents can be used in unique situations. We can make a difference in the lives of persons who have altered functional abilities to promote optional function--no matter what the location. 相似文献
26.
27.
D Lundgren H Rylander M Andersson C Johansson T Albrektsson 《Clinical oral implants research》1992,3(3):136-143
The aim of these animal experiments was to characterize and evaluate the healing-in of root analogue titanium implants fitting with high precision to the alveolar wall. Four beagle dogs were used in the study. The roots of the 3rd and 4th mandibular premolars in both quadrants of 3 dogs and in 1 quadrant of 1 dog (dog 4) were extracted after hemisection. Each root was machine-copied to 1 titanium analogue. In dog 4, however, 2 titanium analogues were fabricated from each of the 4 extracted roots. This enabled insertion of analogues also into the contralateral sockets obtained by extraction of the corresponding roots immediately before implant installation, which was undertaken 2 weeks after the first extractions. Thus, in all, 32 analogues were implanted in their respective (or contralateral) sockets following ridge incision and elevation of mucoperiosteal flaps. The analogues were carefully covered by the repositioned flaps. In dog 4, 2 analogues from the immediate sockets and 2 from the 2-week sockets were surgically exposed and supplied with titanium crowns after a healing period of 2 months. The healing after implantation was evaluated by clinical, radiographic and histological measures after 2, 12 or 36 months. Two analogues (6%) were lost due to early (during the 1st week) exposure to the oral cavity. Another 2 analogues (6%) were, although not exposed, encapsulated by soft tissue and were easily removed with a surgical forceps. Twenty-eight analogues (88%) were healed-in by contact between bone and implant (osseointegration).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
28.
Barry W McColl Ailsa L McGregor Andrew Wong Julian D Harris Andrea Amalfitano Sandra Magnoni Andrew H Baker George Dickson Karen Horsburgh 《Journal of cerebral blood flow and metabolism》2007,27(3):477-487
Apolipoprotein E (apoE, protein; APOE, gene) is the major lipid-transport protein in the brain and plays an important role in modulating the outcome and regenerative processes after acute brain injury. The aim of the present study was to determine if gene transfer of the epsilon3 form of APOE improves outcome in a murine model of transient focal cerebral ischaemia. Mice received an intrastriatal injection of vehicle, a second-generation adenoviral vector containing the green fluorescent protein gene (Ad-GFP) or a vector containing the APOE epsilon3 gene (Ad-APOE) 3 days before 60 mins focal ischaemia. Green fluorescent protein expression was observed in cells throughout the striatum and subcortical white matter indicating successful gene transfer and expression. ApoE levels in the brain were significantly increased after Ad-APOE compared with Ad-GFP or vehicle treatment. Ad-APOE treatment reduced the volume of ischaemic damage by 50% compared with Ad-GFP or vehicle treatment (13+/-3 versus 29+/-4 versus 27+/-5 mm(3)). The extent of postischaemic apoE immunoreactivity was enhanced in Ad-APOE compared with Ad-GFP or vehicle treated mice. These results show the ability of APOE gene transfer to markedly improve outcome after cerebral ischaemia and suggest that modulating apoE levels may be a potential strategy in human stroke therapy. 相似文献
29.
30.
Christopher B. O'Brien Barbara S. Henzel Larry Wolfe Karen Gutekunst Dilip Moonka 《Digestive diseases and sciences》1997,42(5):1087-1093
Reports suggest that response tointerferon-alpha therapy is influenced by both hepatitisC viral genotype and titer. Our aim was to determine ifdirect, automated, cycle sequencing of the PCR productfrom an HCV RNA detection assay could be used toreliably determine HCV genotype. In addition, theapproach was used to determine the HCV genotypedistribution in our patient population and to learn ifthere was a correlation between HCV genotype and RNAtiter that could be used to predict response totreatment. In all 143 consecutive patients were testedfor both HCV RNA titer and genotype. Automated, cycle sequencing of PCR product was highly effectiveand failed to yield a genotype in only 3 (2%) patients.The distribution of HCV genotypes was: 1a (40%), 1b(39%), 2a (2%), 2b (6%), 3a (4%). There were significant differences in the median HCV RNA titersbetween genotypes 1, 2, and 3. 6 High HCV RNA titers>4.4 × 106 copies/ml were only seenin genotype 1. However, the HCV RNA level should not beused as a surrogate marker of genotype because of a significantoverlap of titers within the genotypes. 相似文献