全文获取类型
收费全文 | 3015篇 |
免费 | 207篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 34篇 |
儿科学 | 92篇 |
妇产科学 | 120篇 |
基础医学 | 416篇 |
口腔科学 | 61篇 |
临床医学 | 461篇 |
内科学 | 537篇 |
皮肤病学 | 40篇 |
神经病学 | 362篇 |
特种医学 | 46篇 |
外科学 | 268篇 |
综合类 | 27篇 |
一般理论 | 2篇 |
预防医学 | 325篇 |
眼科学 | 113篇 |
药学 | 162篇 |
中国医学 | 3篇 |
肿瘤学 | 167篇 |
出版年
2023年 | 15篇 |
2022年 | 35篇 |
2021年 | 86篇 |
2020年 | 49篇 |
2019年 | 51篇 |
2018年 | 79篇 |
2017年 | 55篇 |
2016年 | 74篇 |
2015年 | 84篇 |
2014年 | 105篇 |
2013年 | 157篇 |
2012年 | 210篇 |
2011年 | 215篇 |
2010年 | 118篇 |
2009年 | 118篇 |
2008年 | 178篇 |
2007年 | 182篇 |
2006年 | 199篇 |
2005年 | 187篇 |
2004年 | 191篇 |
2003年 | 180篇 |
2002年 | 155篇 |
2001年 | 38篇 |
2000年 | 34篇 |
1999年 | 39篇 |
1998年 | 39篇 |
1997年 | 28篇 |
1996年 | 19篇 |
1995年 | 22篇 |
1994年 | 20篇 |
1993年 | 19篇 |
1992年 | 13篇 |
1991年 | 18篇 |
1990年 | 19篇 |
1989年 | 17篇 |
1988年 | 15篇 |
1987年 | 9篇 |
1986年 | 10篇 |
1985年 | 9篇 |
1984年 | 16篇 |
1983年 | 22篇 |
1982年 | 10篇 |
1981年 | 7篇 |
1980年 | 13篇 |
1979年 | 7篇 |
1978年 | 7篇 |
1977年 | 8篇 |
1976年 | 12篇 |
1974年 | 7篇 |
1967年 | 7篇 |
排序方式: 共有3236条查询结果,搜索用时 234 毫秒
21.
22.
23.
Kazunori Yoneda Tetsuya Yamamoto Eisaku Ueta Tokio Osaki 《Journal of clinical immunology》1992,12(4):289-299
Lymphokine-activated killer (LAK) cells were induced with low-dose recombinant interleukin 2 (rIL-2) and recombinant interferon- (IFN-) in 28 oral carcinoma patients. The patients received daily intravenous injections of rIL-2 (1.2×105 U/m2) and rIFN- (7.0×104 U/m2), and both natural killer (NK) and LAK activities were periodically examined. A significant increase in CD16+CD57+ and CD16+CD57– NK subsets was observed after the induction. An increase in the T-cell population was also found, with a significant increase in CD3+HLA-DR+, CD8+Leu8–, and CD4+Leu8– cells. Significant increases in NK activity, from the original level of 32.0±13.7 to 49.9±15.2%, and LAK activity, from 4.8±3.5 to 11.0±6.1%, at Day 7 were observed. Both activities were maintained at high levels during the cytokine injections, but greater enhancement of the killing activities could not be obtained subsequently. When NK and LAK activities were investigated in each subpopulation of CD3– and CD16– cells, no remarkable cytotoxic activity could be observed before induction in any subset without NK activity in CD3– cells (31.1±14.3%). At Day 7, NK activity of CD16– cells increased up to 21.4±14.9%, accompanied by an increase in CD3–-cell activity (54.5±20.6%). LAK activities of both subsets were also enhanced, with activity at Day 7 of 6.5±5.6 and 9.4±6.6% in CD16– and CD3– cells, respectively. These increased activities were maintained at the same level during the induction. Phorbol myristate acetate-induced polymorphonuclear leukocyte (PMNL) O
2
–
generation was significantly increased, from the original 81.1±28.1 to 95.6±34.9 pmol/min/104 cells, after 1 week of treatment. Protein kinase C activity in the cytosol decreased, and the activity in the membrane fraction conversely increased. No remarkable adverse effects except for mild fever were observed. Together with LAK induction ability and PMNL enhancement, with scarce toxicity, a combination of low-dose rIL-2 and rIFN- is thought to be useful in cancer treatments. 相似文献
24.
Kainz Elena Stuff Karin Kahl Ursula Wiessner Christian Yu Yuanyuan von Breunig Franziska Nitzschke Rainer Haese Alexander Graefen Markus Fischer Marlene 《Quality of life research》2022,31(8):2397-2410
Quality of Life Research - The objective of this study was to determine the influence of postanesthesia care unit (PACU) delirium on self-reported cognitive function and perceived health... 相似文献
25.
Juliana F. W. Cohen Amelie A. Hecht Gabriella M. McLoughlin Lindsey Turner Marlene B. Schwartz 《Nutrients》2021,13(3)
The school environment plays an important role in children’s diets and overall health, and policies for universal free school meals have the potential to contribute to positive child health outcomes. This systematic review evaluates studies examining the association between universal free school meals and students’ school meal participation rates, diets, attendance, academic performance, and Body Mass Index (BMI), as well as school finances. The search was conducted in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA). A search for studies published in economically developed countries published through December 2020 was performed in PubMed, Education Resources Information Center (ERIC), Thomson Reuters’ Web of Science, and Academic Search Ultimate, followed by examining the references in the resultant literature. A total of 47 studies were identified and the Newcastle-Ottawa Scale (NOS) was applied to assess bias. Nearly all studies examining universal free school meals found positive associations with school meal participation. Most studies examining universal free school meals that included free lunch found positive associations with diet quality, food security, and academic performance; however, the findings of studies examining only universal free breakfast were mixed. Research findings were similarly mixed when examining attendance as an outcome. Concerns about adverse outcomes on student BMI were not supported by the literature; in fact, several studies detected a potentially protective effect of universal free school meals on BMI. Research examining the impact of universal free meals on school finances was limited, but suggest that lower-income school districts in the U.S. may have positive financial outcomes from participation in universal free school meal provisions. Additionally, providing free meals to students may be associated with improved household incomes, particularly among lower-income families with children. Further research is needed to examine the financial implications of universal free meals for both school districts and families. Overall, universal free school meals may have multiple benefits for students and countries should consider universal free school meal provisions with strong nutrition guidelines. (PROSPERO registration: CRD42020221782). 相似文献
26.
Marlene Fabiola Escobedo-Monge María Carmen Torres-Hinojal Enrique Barrado María Antonieta Escobedo-Monge Jos Manuel Marugn-Miguelsanz 《Nutrients》2021,13(4)
Background: Zinc is an essential trace element for the normal growth and development of human beings. The main objective was to evaluate the nutritional status of zinc and its association with nutritional indicators in a series of children with chronic diseases. Methods: The prevalence of patients with dietary zinc deficiency or deficit zinc intake (<80% DRI: dietary reference intake) was analyzed through prospective 72 h dietary surveys, and serum zinc deficiency or hypozincemia (≤70 µg/dL in children under 10 years of age in both sexes and in females older than 10 years and <74 μg/dL in males older than 10 years) was measured through atomic absorption spectrophotometry. The participants were classified according to their nutritional status by body mass index (BMI). Results: Mean serum zinc level in obese (87 µg/dL), undernourished (85 µg/dL), and eutrophic children (88 µg/dL) were normal, but in the undernutrition (60% DRI) and eutrophic (67% DRI) groups the mean dietary zinc intake was low compared to that in the obesity group (81% DRI). There were different associations between nutritional parameters, dietary zinc intake, and serum zinc. All patients with hypozincemia had dietary zinc deficiency. Conclusions: In the whole series, 69% of participants showed a zinc intake lower than recommended and might be at high risk of zinc deficiency. 相似文献
27.
Die Anaesthesiologie - Die intraoperative Dosierung von Opioiden stellt eine Herausforderung im anästhesiologischen Alltag dar; insbesondere, da potenzielle Effekte einer intraoperativen... 相似文献
28.
Lisa Marlene Krassuski Sibylle Kautz-Freimuth Vera Vennedey Kerstin Rhiem Rita K. Schmutzler Stephanie Stock 《Geburtshilfe und Frauenheilkunde》2021,81(6):679
Introduction Women with a pathogenic BRCA1/2 mutation have a markedly increased lifetime risk of developing breast and/or ovarian cancer. The current preventive treatment alternatives that are offered are an intensified breast cancer screening programme and risk-reducing operations. Before deciding on one option, medical and personal factors such as life situation and individual preferences must be weighed carefully. Decision aids are used internationally to support BRCA1/2 mutation carriers during their decision-making process. In this study these are analysed structurally for the first time and their applicability to the German context is examined. Material and Methods A systematic literature search in five electronic databases and a manual search were performed. The identified decision aids were evaluated with regard to formal criteria, medical content and quality. The qualitative assessment used the criteria of the International Patient Decision Aid Standards Collaboration (IPDASi v4.0), which examined various dimensions (e.g., information, probabilities, values). Results Twenty decision aids, which were published between 2003 and 2019 in Australia (n = 4), the United Kingdom (n = 3), Canada (n = 2), the Netherlands (n = 2) and the USA (n = 9), were included. Nine focus on BRCA1/2 mutation carriers and eleven include other risk groups. Eighteen include risk-reducing operations as decision options, 14 list screening methods for breast and/or ovarian cancer, and 13 describe the possibility of pharmacological prevention by means of selective oestrogen receptor modulators or aromatase inhibitors. Nine of the 20 decision aids meet fundamental quality criteria (IPDASi v4.0 qualification criteria). Conclusion International decision aids can serve formally as a basis for a German decision aid for BRCA1/2 mutation carriers. Some of them differ markedly in content from the recommendations of German guidelines. Only a few achieve a high quality. Key words: BRCA1, BRCA2, decision aid, familial breast cancer, familial ovarian cancer 相似文献
29.
30.