全文获取类型
收费全文 | 1935篇 |
免费 | 112篇 |
出版年
2022年 | 30篇 |
2021年 | 45篇 |
2020年 | 23篇 |
2019年 | 22篇 |
2018年 | 32篇 |
2017年 | 33篇 |
2016年 | 48篇 |
2015年 | 97篇 |
2014年 | 105篇 |
2013年 | 156篇 |
2012年 | 153篇 |
2011年 | 146篇 |
2010年 | 84篇 |
2009年 | 67篇 |
2008年 | 104篇 |
2007年 | 104篇 |
2006年 | 81篇 |
2005年 | 81篇 |
2004年 | 84篇 |
2003年 | 67篇 |
2002年 | 69篇 |
2001年 | 34篇 |
2000年 | 35篇 |
1999年 | 19篇 |
1998年 | 21篇 |
1997年 | 16篇 |
1996年 | 19篇 |
1995年 | 14篇 |
1994年 | 9篇 |
1993年 | 16篇 |
1992年 | 13篇 |
1991年 | 25篇 |
1990年 | 14篇 |
1989年 | 15篇 |
1988年 | 11篇 |
1987年 | 14篇 |
1986年 | 8篇 |
1985年 | 11篇 |
1984年 | 21篇 |
1983年 | 9篇 |
1982年 | 10篇 |
1981年 | 8篇 |
1980年 | 5篇 |
1979年 | 8篇 |
1976年 | 3篇 |
1974年 | 7篇 |
1973年 | 4篇 |
1972年 | 5篇 |
1967年 | 3篇 |
1949年 | 3篇 |
排序方式: 共有2047条查询结果,搜索用时 218 毫秒
981.
Domino Determann Ida J. Korfage Mattijs S. Lambooij Michiel Bliemer Jan Hendrik Richardus Ewout W. Steyerberg Esther W. de Bekker-Grob 《PloS one》2014,9(7)
Background
Preventive measures are essential to limit the spread of new viruses; their uptake is key to their success. However, the vaccination uptake in pandemic outbreaks is often low. We aim to elicit how disease and vaccination characteristics determine preferences of the general public for new pandemic vaccinations.Methods
In an internet-based discrete choice experiment (DCE) a representative sample of 536 participants (49% participation rate) from the Dutch population was asked for their preference for vaccination programs in hypothetical communicable disease outbreaks. We used scenarios based on two disease characteristics (susceptibility to and severity of the disease) and five vaccination program characteristics (effectiveness, safety, advice regarding vaccination, media attention, and out-of-pocket costs). The DCE design was based on a literature review, expert interviews and focus group discussions. A panel latent class logit model was used to estimate which trade-offs individuals were willing to make.Results
All above mentioned characteristics proved to influence respondents’ preferences for vaccination. Preference heterogeneity was substantial. Females who stated that they were never in favor of vaccination made different trade-offs than males who stated that they were (possibly) willing to get vaccinated. As expected, respondents preferred and were willing to pay more for more effective vaccines, especially if the outbreak was more serious (€6–€39 for a 10% more effective vaccine). Changes in effectiveness, out-of-pocket costs and in the body that advises the vaccine all substantially influenced the predicted uptake.Conclusions
We conclude that various disease and vaccination program characteristics influence respondents’ preferences for pandemic vaccination programs. Agencies responsible for preventive measures during pandemics can use the knowledge that out-of-pocket costs and the way advice is given affect vaccination uptake to improve their plans for future pandemic outbreaks. The preference heterogeneity shows that information regarding vaccination needs to be targeted differently depending on gender and willingness to get vaccinated. 相似文献982.
Robine Hofman Esther W. de Bekker-Grob Jan Hendrik Richardus Harry J. de Koning Marjolein van Ballegooijen Ida J. Korfage 《PloS one》2014,9(8)
Objectives
To assess how girls'' preferences have changed almost 3 years after the much debated start of the human papillomavirus (HPV) vaccination program.Methods
A discrete choice experiment (DCE) was conducted among girls aged 11–15 years who were invited, or were not yet invited, to get vaccinated. A panel latent class model was used to determine girls'' preferences for vaccination based on five characteristics: degree of protection against cervical cancer; duration of protection; risk of mild side-effects; age of vaccination; and the number of required doses of the vaccine.Results
The response rate was 85% (500/592). Most girls preferred vaccination at age 14 years (instead of at age 9 years) and a 2-dose scheme (instead of the current 3-dose scheme). Girls were willing to trade-off 7% (CI: 3.2% to 10.8%) of the degree of protection to have 10% less risk of mild side-effects, and 4% (CI: 1.2% to 5.9%) to receive 2 doses instead of 3 doses. Latent class analyses showed that there was preference heterogeneity among girls, i.e., higher educated girls and HPV vaccinated girls had a higher probability to opt for HPV vaccination at a higher age than lower educated girls or non-vaccinated girls.Conclusions
Three years after the start of HPV vaccination program the risk of mild side-effects and age at vaccination seem to have become less important. For the Dutch national immunization program, we recommend not to lower the current target age of 12 years. A 2-dose scheme may result in a higher uptake and we recommend that if this scheme is introduced, it needs to receive adequate publicity. 相似文献983.
Thomas Heilskov-Hansen Susanne Wulff Svendsen Jane Fr?lund Thomsen Sigurd Mikkelsen Gert-?ke Hansson 《PloS one》2014,9(11)
Objectives
Sex differences in occupational biomechanical exposures may be part of the explanation why musculoskeletal complaints and disorders tend to be more common among women than among men. We aimed to determine possible sex differences in task distribution and task-specific postures and movements of the upper extremities among Danish house painters, and to establish sex-specific task exposure matrices.Methods
To obtain task distributions, we sent out a questionnaire to all members of the Painters'' Union in Denmark (N = 9364), of whom 53% responded. Respondents reported their task distributions in a typical week. To obtain task exposures, postures and movements were measured in 25 male and 25 female house painters for one whole working day per person. We used goniometers on the wrists, and inclinometers on the forehead and the upper arms. Participants filled in a logbook allowing task-specific exposures to be identified. Percentiles and % time with non-neutral postures were used to characterise postures. Velocity, range of motion, repetitiveness, and variation were used as measures of movement. Cochran-Mantel-Haenszel statistics and unpaired double-sided t-tests with post-hoc Bonferroni correction were used to evaluate sex differences.Results
Statistically significant (p<0.05) sex differences were revealed in task proportions, but the proportions differed by less than 4%. For task exposures, no statistically significant sex differences were found.Conclusions
Only minor sex differences were found in task distribution and task exposures regarding postures and movements among Danish house painters. Sex-specific task exposure matrices were established. 相似文献984.
Hunt JA Kallashi F Ruzek RD Sinclair PJ Ita I McCormick SX Pivnichny JV Hop CE Kumar S Wang Z O'Keefe SJ O'Neill EA Porter G Thompson JE Woods A Zaller DM Doherty JB 《Bioorganic & medicinal chemistry letters》2003,13(3):467-470
We have synthesized a series of C7-piperidine- and 4-aminopiperidine-substituted naphthyridinones, quinolinones, and dihydroquinazolinones that are highly potent inhibitors of both p38MAP kinase activity and TNF-alpha release. The 4-aminopentamethylpiperidine naphthyridinone 5, which was designed to block metabolism at major 'hot spots', combined excellent inhibitory potency with good oral bioavailability in the rat. 相似文献
985.
986.
Membrane remodeling is an important aspect in organelle biogenesis. We show that different peroxisome membrane proteins that play a role in organelle biogenesis and proliferation (Pex8, Pex10, Pex14, Pex25 and Pex11) are subject to spatiotemporal behavior during organelle development. Using fluorescence microscopy analysis of Hansenula polymorpha dnm1 cells that are blocked in the normal fission process, we show that green fluorescent protein (GFP) fusions of Pex8, Pex10, Pex14 and Pex25 show enhanced fluorescence at the organelle extensions that are formed in budding cells. In contrast, Pex11 fluorescence is enriched at the base of this extension on the mother organelle. A fusion protein of GFP with the transporter Pmp47, used as a control, did not show enhanced fluorescence at any specific region of the organelle. The concentration of specific peroxins at the peroxisome surface was lost upon deletion of PEX11 or the N-terminal domain of Pex11 that is involved in membrane remodeling. Comparable distribution patterns as in dnm1 cells were observed in wild-type cells where Pex8, Pex10, Pex14 and Pex25, but not Pex11, were especially present at newly formed organelles that migrated to the bud. We speculate that peroxin reorganization events result in enhanced levels of peroxins involved in peroxisome biogenesis in nascent organelles. 相似文献
987.
Opaliński Ł Veenhuis M van der Klei IJ 《The international journal of biochemistry & cell biology》2011,43(6):847-851
Peroxisomes are ubiquitous organelles surrounded by a single membrane that display a variety of metabolic functions. These vary with the organism in which they occur and with environmental conditions. Peroxisomes multiply by division of existing organelles and can be formed from ER. The peroxisomal membrane, akin to the organelle itself, is a very dynamic structure that obtains building blocks from the ER. It can form diverse organized structures - lipid domains - that can be involved in regulation of various vesicle fusion processes. Additionally, this membrane may undergo extensive changes in lipid composition. We recently showed that upon proliferation the peroxisomal membrane changes its curvature in response to the activity of the peroxisomal membrane protein Pex11. Tubulation of the organelle may be important for efficient recruitment of GTPases from the dynamin protein family that is involved in organelle fission. 相似文献
988.
Fetal and adult multipotent mesenchymal stromal cells are killed by different pathways 总被引:1,自引:0,他引:1
Background aimsMultipotent mesenchymal stromal cells, also known as mesenchymal stem cells (MSC), can be isolated from adult and fetal tissues. Recently, there has been considerable interest in MSC because they have features favorable for transplantation, namely their multipotency and non-immunogenic properties.MethodsWe analyzed how human MSC derived from first-trimester fetal liver and adult bone marrow interact with naive and activated innate natural killer (NK) cells. NK cell function was studied by measuring killing of MSC, as well as degranulation (CD107a) induced by MSC. To assess the importance of NK cell killing, expression of surface epitopes was analyzed by flow cytometry on MSC before and after stimulation with interferon (IFN)γ.ResultsFetal and adult MSC express several ligands to activating NK cell receptors as well as low levels of HLA class I, with large inter-individual variation. Naive peripheral blood NK cells did not lyse fetal or adult MSC, whereas interleukin (IL)2 activated allogeneic as well as autologous NK cells did. Pre-incubation of MSC with IFN-γ increased their levels of HLA class I, protecting them from NK cell recognition. Fetal and adult MSC were preferably killed via the tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) and Fas ligand (FasL) pathways, respectively. Blocking NKG2D reduced NK cell degranulation in both fetal and adult MSC.ConclusionsFetal and adult MSC differ in their interactions with NK cells. Both fetal and adult MSC are susceptible to lysis by activated NK cells, which may have implications for the use of MSC in cell therapy. 相似文献
989.
990.
Church DM Schneider VA Graves T Auger K Cunningham F Bouk N Chen HC Agarwala R McLaren WM Ritchie GR Albracht D Kremitzki M Rock S Kotkiewicz H Kremitzki C Wollam A Trani L Fulton L Fulton R Matthews L Whitehead S Chow W Torrance J Dunn M Harden G Threadgold G Wood J Collins J Heath P Griffiths G Pelan S Grafham D Eichler EE Weinstock G Mardis ER Wilson RK Howe K Flicek P Hubbard T 《PLoS biology》2011,9(7):e1001091