全文获取类型
收费全文 | 25923篇 |
免费 | 1757篇 |
国内免费 | 51篇 |
专业分类
耳鼻咽喉 | 213篇 |
儿科学 | 898篇 |
妇产科学 | 712篇 |
基础医学 | 3236篇 |
口腔科学 | 391篇 |
临床医学 | 3979篇 |
内科学 | 4685篇 |
皮肤病学 | 317篇 |
神经病学 | 2584篇 |
特种医学 | 536篇 |
外科学 | 2154篇 |
综合类 | 277篇 |
一般理论 | 64篇 |
预防医学 | 3746篇 |
眼科学 | 348篇 |
药学 | 1464篇 |
1篇 | |
中国医学 | 33篇 |
肿瘤学 | 2093篇 |
出版年
2023年 | 94篇 |
2022年 | 142篇 |
2021年 | 448篇 |
2020年 | 308篇 |
2019年 | 476篇 |
2018年 | 576篇 |
2017年 | 449篇 |
2016年 | 458篇 |
2015年 | 518篇 |
2014年 | 818篇 |
2013年 | 1275篇 |
2012年 | 1845篇 |
2011年 | 1955篇 |
2010年 | 1050篇 |
2009年 | 927篇 |
2008年 | 1778篇 |
2007年 | 1871篇 |
2006年 | 1839篇 |
2005年 | 1884篇 |
2004年 | 1800篇 |
2003年 | 1713篇 |
2002年 | 1571篇 |
2001年 | 206篇 |
2000年 | 159篇 |
1999年 | 264篇 |
1998年 | 349篇 |
1997年 | 246篇 |
1996年 | 238篇 |
1995年 | 224篇 |
1994年 | 192篇 |
1993年 | 182篇 |
1992年 | 122篇 |
1991年 | 114篇 |
1990年 | 88篇 |
1989年 | 105篇 |
1988年 | 88篇 |
1987年 | 81篇 |
1986年 | 79篇 |
1985年 | 88篇 |
1984年 | 118篇 |
1983年 | 119篇 |
1982年 | 135篇 |
1981年 | 121篇 |
1980年 | 115篇 |
1979年 | 63篇 |
1978年 | 64篇 |
1977年 | 64篇 |
1976年 | 51篇 |
1975年 | 45篇 |
1974年 | 43篇 |
排序方式: 共有10000条查询结果,搜索用时 281 毫秒
81.
82.
Nancy I Thomas Norman DePaul Brown Linda C Hodges Jay Gandy Louanne Lawson Janet E Lord David K Williams 《AAOHN journal》2006,54(1):24-31
The Central Arkansas Veterans Healthcare System (CAVHS) spends $1 million annually on occupational illnesses and injuries. To address the problem of injuries among hospital employees, a retrospective case-control study was conducted to examine select risk factors for work-related injuries (WRI) among CAVHS employees. Study methods included a review of employee health charts and computer and manual databases from 1997 to 2002 (N = 2,050). The researchers found that WRI increased with age; WRI occurred more often in women than in men; WRI was greater among maintenance and custodial staff compared to direct caregivers, and less among clerical staff; WRI occurred less often in part-time than full-time staff; and WRI increased with increasing body mass index. Developing standards, guidelines, and policies for preplacement screening, preventive measures, training, and education may help to minimize WRI and associated costs. 相似文献
83.
We compared several pharmacological and enzymatic effects induced by 11 snake venoms from seven species, six of them from different geographic areas of Antioquia and Choco, north-west of Colombia, South America (Bothrops atrox, B. nasutus, B. schlegelii, B. punctatus, Lachesis muta, Micrurus mipartitus), and Crotalus durissus terrificus venom, from specimens captured in other provinces of the country (Tolima, Huila, Meta and Atlantico). Differences were observed in edema-forming, hemorrhage, defibrination, indirect hemolysis, myonecrosis, proteolysis and lethal activity between venoms from different genera or species, as well as according to the geographic area of origin in B. atrox and B. nasutus snake venoms. Bothrops venoms, in particular B. atrox and L. muta, produced major local effects. All of the venoms, including M. mipartitus, had myotoxic effects. The most defibrinating venoms were B. atrox, L. muta, B. punctatus and C. d. terrificus. All of the venoms had indirect hemolytic activity; the venom of M. mipartitus being greatest. The most lethal venoms were those of C. d. terrificus and M. mipartitus. Within Bothrops species, the venom of B. schlegelii was the least active in terms of local and systemic pathologic effects. 相似文献
84.
85.
Jun Gu Yang O Huh Feng Jiang Nancy P Caraway Jorge E Romaguera Tanweer M Zaidi Ricardo L Fernandez Huazhong Zhang Issa F Khouri Ruth L Katz 《Modern pathology》2004,17(5):553-560
Mantle cell lymphoma is non-Hodgkin's B-cell lymphoma characterized by the t(11;14)(q13;q32) translocation. Peripheral blood involvement of mantle cell lymphoma is usually associated with a poor prognosis and therefore, its identification is clinically important. In this study, we performed cyclin D1/IgH-probe fusion fluorescence in situ hybridization analysis on 223 peripheral blood samples: 185 from 125 mantle cell lymphoma patients, and 38 normal controls. The cutoff values for the test were established using normal controls. Flow cytometry on peripheral blood and corresponding bone marrow samples was used to evaluate this test. In all, 26% of the 185 peripheral blood samples and 27% of the 161 corresponding bone marrow samples were flow cytometry positive for mantle cell lymphoma. The mean numbers of single and- double-fusion signals and the mean number of CD5/CD19-positive cells, absolute blood lymphocyte count, and white blood cell count were significantly higher in peripheral blood and corresponding bone marrow samples with mantle cell lymphoma-positive flow cytometry. Double-fusion signals were more specific than single-fusion ones. Fluorescence in situ hybridization was far more likely to be positive for mantle cell lymphoma when the peripheral blood and the corresponding bone marrow samples had positive flow cytometry results or morphology (P<0.01). Our study indicates that cyclin D1/IgH-fusion fluorescence in situ hybridization analysis could be used to determine the presence and character of circulating mantle cell lymphoma cells in peripheral blood, thus enhancing our ability to evaluate leukemic mantle cell lymphoma and minimum residual disease. 相似文献
86.
87.
Nancy J Keuthen Nikos Makris John E Schlerf Brian Martis Cary R Savage Katherine McMullin Larry J Seidman Jeremy D Schmahmann David N Kennedy Steven M Hodge Scott L Rauch 《Neuropsychopharmacology》2007,61(3):374-381
BACKGROUND: Limited knowledge exists regarding the neurobiology of trichotillomania (TTM). Cerebellum (CBM) volumes were explored, given its role in complex, coordinated motor sequences. METHODS: Morphometric magnetic resonance imaging (MRI) scans were obtained for 14 female subjects with DSM-IV diagnoses of TTM and 12 age-, education-, and gender-matched normal control (NC) participants. Parcellation was performed utilizing a recently developed methodology to measure subterritory volumes of the CBM. Regions were defined based on knowledge of the structural and functional subunits of the CBM. RESULTS: As predicted, significant group differences were reported for CBM raw cortical volumes (p = .008) that survived correction for total brain volume (TBV; p = .037) and head circumference (HC; p = .011). A priori and post hoc group raw volume comparisons for CBM subterritories and functional clusters revealed many significant differences. However, most differences failed to withstand correction for total CBM volumes (TCV). Smaller volumes were consistently reported for the TTM versus NC cohorts. Total Massachusetts General Hospital Hair Pulling Scale (MGHHPS) scores were significantly inversely correlated with left primary sensorimotor cluster volumes (p = .008), with smaller volumes associated with more severe TTM symptoms. CONCLUSIONS: These findings implicate the CBM in the neurobiology of TTM, with reduced subterritory volumes reported for the TTM versus NC groups. 相似文献
88.
89.
BACKGROUND: Little information is available nationally about critical care units and nurses. What is known about nurses in hospitals is generally not broken down among all the specialties. OBJECTIVES: To describe issues of workforce, compensation, and care specific to critical care units and nurses who work in them. METHODS: The American Association of Critical-Care Nurses conducted a survey of randomly selected facilities with critical care units in the United States. Facilities were solicited via e-mail to respond to a survey on the World Wide Web and provide information on operations, evaluations, nursing staff reimbursement and incentives, staffing, and quality indicators. Responding facilities also provided contact information for units in the facilities. Those units were surveyed about operations, acuity systems, staffing, policies on visitation and end-of-life care, administrative structure, documentation, certification, professional advancement, vacancy/floating, staff satisfaction, orientation, association membership, wages, advanced practice nursing, and quality indicators. RESULTS: The initial response rate (120 of 658 eligible facilities) was 18.2%, and 300 of 576 solicited units nominated by the facilities responded, yielding a 52.1% response rate for the second phase. CONCLUSIONS: These survey data define the scope and intensity of services offered and provide more specific figures about staffing issues and unit practices than has been accessible before. Healthcare providers may use this information for benchmarking purposes, especially for instances in which the tables provide data for each particular type of critical care unit. 相似文献
90.