全文获取类型
收费全文 | 467篇 |
免费 | 50篇 |
国内免费 | 3篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 37篇 |
妇产科学 | 2篇 |
基础医学 | 80篇 |
口腔科学 | 6篇 |
临床医学 | 71篇 |
内科学 | 119篇 |
皮肤病学 | 5篇 |
神经病学 | 24篇 |
特种医学 | 9篇 |
外科学 | 39篇 |
综合类 | 1篇 |
一般理论 | 1篇 |
预防医学 | 29篇 |
眼科学 | 3篇 |
药学 | 35篇 |
中国医学 | 3篇 |
肿瘤学 | 47篇 |
出版年
2024年 | 3篇 |
2023年 | 1篇 |
2022年 | 8篇 |
2021年 | 19篇 |
2020年 | 11篇 |
2019年 | 11篇 |
2018年 | 12篇 |
2017年 | 13篇 |
2016年 | 9篇 |
2015年 | 15篇 |
2014年 | 21篇 |
2013年 | 24篇 |
2012年 | 41篇 |
2011年 | 47篇 |
2010年 | 26篇 |
2009年 | 15篇 |
2008年 | 22篇 |
2007年 | 26篇 |
2006年 | 23篇 |
2005年 | 22篇 |
2004年 | 27篇 |
2003年 | 23篇 |
2002年 | 20篇 |
2001年 | 7篇 |
2000年 | 4篇 |
1999年 | 8篇 |
1998年 | 5篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 6篇 |
1994年 | 7篇 |
1993年 | 2篇 |
1992年 | 8篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 5篇 |
1987年 | 1篇 |
1985年 | 3篇 |
1983年 | 1篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1978年 | 2篇 |
1967年 | 1篇 |
1966年 | 1篇 |
1963年 | 1篇 |
1945年 | 1篇 |
1933年 | 1篇 |
1928年 | 1篇 |
排序方式: 共有520条查询结果,搜索用时 15 毫秒
1.
Elizabeth Landerholm 《Early child development and care》1994,101(1):13-22
The computer use of two classrooms of kindergarten aged children in private school in Chicago were compared for variance in terms of the age and sex of the children, for variance by classroom, and for variance in the software selected. The major statistical method used was analysis of variance. There were two dependent variables: total frequency of computer use and the difference between the frequency in the first half and that in the second half (in order to examine the changing pattern of computer use in the two classrooms). There was no significant difference in computer use by sex or age, but there was a significant difference in the frequency of computer by classroom in the second half of the project compared to the first half. There was no significant difference in the software selected. 相似文献
2.
C von Kalle J Wolf A Becker A Sckaer M Munck A Engert U Kapp C Fonatsch D Komitowski W Feaux de Lacroix 《International journal of cancer. Journal international du cancer》1992,52(6):887-891
No animal model exists for the in vivo growth of Hodgkin's-lymphoma-derived cells. Neither unmanipulated Hodgkin's-disease(HD)-derived cell lines nor primary biopsy tissue could be grown in nude mice. Since the severe combined immunodeficient (SCID) mouse has been reported to be a better recipient for transplanted human lymphatic tissue than the nude mouse, we tested whether SCID mice provide suitable conditions for the in vivo growth of HD cell lines. Tumorigenicity of HD cells was tested in untreated and pre-treated SCID mice and in another combined immunodeficient mouse strain, beige/nude/X-linked immunodeficient (BNX) mouse. SCID mice supported in vivo growth of the 6 HD cell lines tested (L428, L540, L591, DEV, HD-LM2, KM-H2). Only one of the 6 lines (DEV) was tumorigenic in BNX mice. No HD cell line proliferated in T-cell-deficient nude mice. Thus, in vivo growth of HD cell lines appeared to be related to the degree of host immunodeficiency. Additional growth supportive treatments such as fibrosarcoma co-transplantation, intraperitoneal mineral oil injection or immunosuppressive pre-treatment (anti-asialo-GMI-antibody injection) permitted growth of 3 additional HD cell lines in BNX mice. The immunophenotype and karyotype of explanted graft cells were identical to the original cell lines. Our experiments describe an effective and reproducible xenograft model for growth of Hodgkin's-disease-derived cell lines. This may be of value for elucidating the growth characteristics of Hodgkin's-lymphoma-derived cells as well as for testing new therapeutic regimens. 相似文献
3.
4.
A mouse model for alpha-methylacyl-CoA racemase deficiency: adjustment of bile acid synthesis and intolerance to dietary methyl-branched lipids 总被引:2,自引:0,他引:2
Savolainen K Kotti TJ Schmitz W Savolainen TI Sormunen RT Ilves M Vainio SJ Conzelmann E Hiltunen JK 《Human molecular genetics》2004,13(9):955-965
alpha-Methylacyl-CoA racemase (Amacr) deficiency in humans leads to sensory motor neuronal and liver abnormalities. The disorder is recessively inherited and caused by mutations in the AMACR gene, which encodes Amacr, an enzyme presumed to be essential for bile acid synthesis and to participate in the degradation of methyl-branched fatty acids. To generate a model to study the pathophysiology in Amacr deficiency we inactivated the mouse Amacr gene. As per human Amacr deficiency, the Amacr(-/-) mice showed accumulation (44-fold) of C27 bile acid precursors and decreased (over 50%) primary (C24) bile acids in bile, serum and liver, however the Amacr(-/-) mice were clinically symptomless. Real-time quantitative PCR analysis showed that, among other responses, the level of mRNA for peroxisomal multifunctional enzyme type 1 (pMFE-1) was increased 3-fold in Amacr(-/-) mice. This enzyme can be placed, together with CYP3A11 and CYP46A1, to make an Amacr-independent pathway for the generation of C24 bile acids. Exposure of Amacr(-/-) mice to a diet supplemented with phytol, a source for branched-chain fatty acids, triggered the development of a disease state with liver manifestations, redefining the physiological significance of Amacr. Amacr is indispensable for the detoxification of dietary methyl-branched lipids and, although it contributes normally to bile acid synthesis from cholesterol, the putative pMFE-1-mediated cholesterol degradation can provide for generation of bile acids, allowing survival without Amacr. Based upon our mouse model, we propose elimination of phytol from the diet of patients suffering from Amacr deficiency. 相似文献
5.
6.
Enhanced film-forming properties for ethyl cellulose and starch acetate using n-alkenyl succinic anhydrides as novel plasticizers 总被引:4,自引:0,他引:4
Maarit Tarvainen Riitta Sutinen Soili Peltonen Hannu Mikkonen Jaana Maunus Kalle Vh-Heikkil Vesa-Pekka Lehto Petteri Paronen 《European journal of pharmaceutical sciences》2003,19(5):363-371
Purpose: The aim of this study was to investigate the ability of n-alkenyl succinic anhydrides (n-ASAs) to improve the film-forming characteristics of a novel coating polymer, potato starch acetate degree of substitution 2.8 (SA). n-ASAs were also applied to improve the otherwise brittle properties of ethyl cellulose (EC) aqueous dispersion (Aquacoat®) and EC solvent-based films. Methods: The effectiveness of two n-ASAs, 2-octenyl succinic anhydride (OSA) and 2-dodecen-1-ylsuccinic anhydride were evaluated as plasticizers. Mechanical properties, both water vapor and drug permeabilities, and glass transition temperatures of the cast free films were measured. Triethyl citrate and dibutyl sebacate were used as reference plasticizers. Results: The long hydrocarbon chain of n-ASA, with its accessible carbonyl groups, enabled a strong plasticization effect on the tested polymers. Due to the excellent mechanical properties (i.e., a tough film structure with considerable flexibility) and low permeability of the plasticized films, n-ASAs, and especially OSA proved to be an ideal plasticizer particularly for EC based coatings. Also, the EC aqueous dispersion plasticized with n-ASAs resulted in a markedly enhanced coalescence of the colloidal polymer particles, even at low drying temperatures. Conclusions: In applications where a coating with high flexibility is required, n-ASAs can be used as plasticizers at moderately high concentrations (up to 60–70%, w/w) without losing the high tensile strength, excellent toughness and low permeability of EC and SA films. 相似文献
7.
Teachers for the twenty-first century for the global world need to be proficient in technology and skilled as reflective practitioners. They need to be able to reflect on diversity in myriad ways: learning styles, special needs, cultural differences, racial differences, developmentally appropriate differences, teaching styles and personality differences of children, teachers, parents, community members and administrators. The paradigni shift of the twenty-first century is that teachers need to be team players who are skilled at operating in a variety of collaborative partnerships.
The Early Childhood Program Faculty, at NEIU, with the help of a Teacher Quality Education grant, developed with six universities in Illinois called Illinois Professionals Learning Partnerships (IPLP), set out to adapt the NEIU/ECED program for the twenty-first century in a global world by focusing on four goals: (1) increasing technology and writing skills across the curriculum, (2) developing reflective skills and understanding of diversity (special needs, multicultural/international cultures), (3) developing student experience working in collaborative partnerships and (4) increasing clinical experiences.
The IPLP grant enabled the ECED program to: (1) spend intensive time on changing the curriculum in two retreats a year, (2) develop a faculty cohort including tenure track faculty, visiting lecturers and adjuncts, (3) develop a combined program of research and program development, (4) recruit and hire three new tenure track international faculty, (5) develop professional development schools and intensive field experiences, (6) combine resources for many grants, (7) develop short-term international experiences and faculty exchange programs and (8) increase technology skills of students and faculty through action laboratories on using video technology, digital cameras, reflective email discussions and videography. 相似文献
The Early Childhood Program Faculty, at NEIU, with the help of a Teacher Quality Education grant, developed with six universities in Illinois called Illinois Professionals Learning Partnerships (IPLP), set out to adapt the NEIU/ECED program for the twenty-first century in a global world by focusing on four goals: (1) increasing technology and writing skills across the curriculum, (2) developing reflective skills and understanding of diversity (special needs, multicultural/international cultures), (3) developing student experience working in collaborative partnerships and (4) increasing clinical experiences.
The IPLP grant enabled the ECED program to: (1) spend intensive time on changing the curriculum in two retreats a year, (2) develop a faculty cohort including tenure track faculty, visiting lecturers and adjuncts, (3) develop a combined program of research and program development, (4) recruit and hire three new tenure track international faculty, (5) develop professional development schools and intensive field experiences, (6) combine resources for many grants, (7) develop short-term international experiences and faculty exchange programs and (8) increase technology skills of students and faculty through action laboratories on using video technology, digital cameras, reflective email discussions and videography. 相似文献
8.
Wen Zhong Swapnali Barde Nicholas Mitsios Csaba Adori Per Oksvold Kalle von Feilitzen Liam OLeary Lszl Csiba Tibor Hortobgyi Pter Szocsics Naguib Mechawar Zsfia Maglczky va Renner Mikls Palkovits Mathias Uhln Jan Mulder Tomas Hkfelt 《Proceedings of the National Academy of Sciences of the United States of America》2022,119(33)
9.
10.
Kalle Hakala Pekka Luukkonen Matti Vuoristo Heikki Järvinen Tatu A. Miettinen 《Journal of hepatology》1997,26(6):1306-1312
Background: Previous studies suggest only minor changes in bile acid metabolism after panproctocolectomy with ileal pouch construction.Aims/Methods: To investigate these changes further, we studied cholesterol absorption and serum, biliary and fecal non-cholesterol sterols and lipids in 12 ileal pouch patients and 10 controls.Results: In patients, cholesterol absorption was markedly reduced and was associated with low serum total and LDL cholesterol and LDL triglyceride levels, but surprisingly, cholesterol synthesis, as indicated by sterol-balance data or serum cholesterol precursor levels, was within low normal limits. The high proportions of serum plant sterol to cholesterol, particularly that of campesterol, were not related to cholesterol absorption, but were attributable to a markedly reduced biliary cholesterol secretion. Interestingly, in these patients the fractional absorption of campesterol was normal, whereas that of sitosterol, like cholesterol, was reduced and was positively related to the intestinal influx of cholesterol. The patients' serum cholestanol proportion was normal, but the proportion of the cholestanol formed during intestinal passage was significantly reduced (17.9% vs 65.2% in controls).Conclusions: Thus ileal pouch patients are characterized by sterol malabsorption, lowered serum total and LDL-cholesterol levels, but unexpectedly without any increase in cholesterol synthesis. The lack of high serum cholestanol, shown earlier frequently in unoperated patients with ulcerative colitis, may indicate reversible cholestasis, a finding deserving further exploration. 相似文献