全文获取类型
收费全文 | 471篇 |
免费 | 36篇 |
出版年
2022年 | 23篇 |
2021年 | 16篇 |
2020年 | 8篇 |
2019年 | 11篇 |
2018年 | 8篇 |
2017年 | 8篇 |
2016年 | 19篇 |
2015年 | 23篇 |
2014年 | 22篇 |
2013年 | 18篇 |
2012年 | 41篇 |
2011年 | 29篇 |
2010年 | 17篇 |
2009年 | 21篇 |
2008年 | 13篇 |
2007年 | 13篇 |
2006年 | 21篇 |
2005年 | 15篇 |
2004年 | 19篇 |
2003年 | 14篇 |
2002年 | 10篇 |
2001年 | 10篇 |
2000年 | 5篇 |
1999年 | 6篇 |
1998年 | 11篇 |
1996年 | 11篇 |
1995年 | 3篇 |
1994年 | 5篇 |
1993年 | 3篇 |
1992年 | 5篇 |
1991年 | 2篇 |
1990年 | 5篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1987年 | 4篇 |
1986年 | 5篇 |
1985年 | 4篇 |
1984年 | 9篇 |
1983年 | 4篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1977年 | 2篇 |
1960年 | 2篇 |
1945年 | 1篇 |
1931年 | 1篇 |
1929年 | 1篇 |
1912年 | 1篇 |
1910年 | 1篇 |
排序方式: 共有507条查询结果,搜索用时 31 毫秒
171.
Joseph Hughes Richard C. Allen Marc Baguelin Katie Hampson Gregory J. Baillie Debra Elton J. Richard Newton Paul Kellam James L. N. Wood Edward C. Holmes Pablo R. Murcia 《PLoS pathogens》2012,8(12)
The ability of influenza A viruses (IAVs) to cross species barriers and evade host immunity is a major public health concern. Studies on the phylodynamics of IAVs across different scales – from the individual to the population – are essential for devising effective measures to predict, prevent or contain influenza emergence. Understanding how IAVs spread and evolve during outbreaks is critical for the management of epidemics. Reconstructing the transmission network during a single outbreak by sampling viral genetic data in time and space can generate insights about these processes. Here, we obtained intra-host viral sequence data from horses infected with equine influenza virus (EIV) to reconstruct the spread of EIV during a large outbreak. To this end, we analyzed within-host viral populations from sequences covering 90% of the infected yards. By combining gene sequence analyses with epidemiological data, we inferred a plausible transmission network, in turn enabling the comparison of transmission patterns during the course of the outbreak and revealing important epidemiological features that were not apparent using either approach alone. The EIV populations displayed high levels of genetic diversity, and in many cases we observed distinct viral populations containing a dominant variant and a number of related minor variants that were transmitted between infectious horses. In addition, we found evidence of frequent mixed infections and loose transmission bottlenecks in these naturally occurring populations. These frequent mixed infections likely influence the size of epidemics. 相似文献
172.
173.
Schneider MV Walter P Blatter MC Watson J Brazas MD Rother K Budd A Via A van Gelder CW Jacob J Fernandes P Nyrönen TH De Las Rivas J Blicher T Jimenez RC Loveland J McDowall J Jones P Vaughan BW Lopez R Attwood TK Brooksbank C 《Briefings in bioinformatics》2012,13(3):383-389
Funding bodies are increasingly recognizing the need to provide graduates and researchers with access to short intensive courses in a variety of disciplines, in order both to improve the general skills base and to provide solid foundations on which researchers may build their careers. In response to the development of 'high-throughput biology', the need for training in the field of bioinformatics, in particular, is seeing a resurgence: it has been defined as a key priority by many Institutions and research programmes and is now an important component of many grant proposals. Nevertheless, when it comes to planning and preparing to meet such training needs, tension arises between the reward structures that predominate in the scientific community which compel individuals to publish or perish, and the time that must be devoted to the design, delivery and maintenance of high-quality training materials. Conversely, there is much relevant teaching material and training expertise available worldwide that, were it properly organized, could be exploited by anyone who needs to provide training or needs to set up a new course. To do this, however, the materials would have to be centralized in a database and clearly tagged in relation to target audiences, learning objectives, etc. Ideally, they would also be peer reviewed, and easily and efficiently accessible for downloading. Here, we present the Bioinformatics Training Network (BTN), a new enterprise that has been initiated to address these needs and review it, respectively, to similar initiatives and collections. 相似文献
174.
Shvedova AA Kapralov AA Feng WH Kisin ER Murray AR Mercer RR St Croix CM Lang MA Watkins SC Konduru NV Allen BL Conroy J Kotchey GP Mohamed BM Meade AD Volkov Y Star A Fadeel B Kagan VE 《PloS one》2012,7(3):e30923
Advancement of biomedical applications of carbonaceous nanomaterials is hampered by their biopersistence and pro-inflammatory action in vivo. Here, we used myeloperoxidase knockout B6.129X1-MPO (MPO k/o) mice and showed that oxidation and clearance of single walled carbon nanotubes (SWCNT) from the lungs of these animals after pharyngeal aspiration was markedly less effective whereas the inflammatory response was more robust than in wild-type C57Bl/6 mice. Our results provide direct evidence for the participation of MPO - one of the key-orchestrators of inflammatory response - in the in vivo pulmonary oxidative biodegradation of SWCNT and suggest new ways to control the biopersistence of nanomaterials through genetic or pharmacological manipulations. 相似文献
175.
Lucinda Hazell Fiona Allan Aidan M. Emery Michael R. Templeton 《PLoS neglected tropical diseases》2021,15(7)
BackgroundSchistosomiasis is a parasitic disease that is transmitted by skin contact with waterborne schistosome cercariae. Mass drug administration with praziquantel is an effective control method, but it cannot prevent reinfection if contact with cercariae infested water continues. Providing safe water for contact activities such as laundry and bathing can help to reduce transmission. In this study we examine the direct effect of UV light on Schistosoma mansoni cercariae using ultraviolet light-emitting diodes (UV LEDs) and a low-pressure (LP) mercury arc discharge lamp.MethodologyS. mansoni cercariae were exposed to UV light at four peak wavelengths: 255 nm, 265 nm, 285 nm (UV LEDs), and 253.7 nm (LP lamp) using bench scale collimated beam apparatus. The UV fluence ranged from 0–300 mJ/cm2 at each wavelength. Cercariae were studied under a stereo-microscope at 0, 60, and 180 minutes post-exposure and the viability of cercariae was determined by assessing their motility and morphology.ConclusionVery high UV fluences were required to kill S. mansoni cercariae, when compared to most other waterborne pathogens. At 265 nm a fluence of 247 mJ/cm2 (95% confidence interval (CI): 234–261 mJ/cm2) was required to achieve a 1-log10 reduction at 0 minutes post-exposure. Cercariae were visibly damaged at lower fluences, and the log reduction increased with time post-exposure at all wavelengths. Fluences of 127 mJ/cm2 (95% CI: 111–146 mJ/cm2) and 99 mJ/cm2 (95% CI: 85–113 mJ/cm2) were required to achieve a 1-log10 reduction at 60 and 180 minutes post-exposure at 265 nm. At 0 minutes post-exposure 285 nm was slightly less effective, but there was no statistical difference between 265 nm and 285 nm after 60 minutes. The least effective wavelengths were 255 nm and 253.7 nm. Due to the high fluences required, UV disinfection is unlikely to be an energy- or cost-efficient water treatment method against schistosome cercariae when compared to other methods such as chlorination, unless it can be demonstrated that UV-damaged cercariae are non-infective using alternative assay methods or there are improvements in UV LED technology. 相似文献
176.
177.
178.
Genome‐wide association of functional traits linked with Campylobacter jejuni survival from farm to fork
下载免费PDF全文
![点击此处可从《Environmental microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Koji Yahara Guillaume Méric Aidan J. Taylor Stefan P. W. de Vries Susan Murray Ben Pascoe Leonardos Mageiros Alicia Torralbo Ana Vidal Anne Ridley Sho Komukai Helen Wimalarathna Alison J. Cody Frances M. Colles Noel McCarthy David Harris James E. Bray Keith A. Jolley Martin C. J. Maiden Stephen D. Bentley Julian Parkhill Christopher D. Bayliss Andrew Grant Duncan Maskell Xavier Didelot David J. Kelly Samuel K. Sheppard 《Environmental microbiology》2017,19(1):361-380
Campylobacter jejuni is a major cause of bacterial gastroenteritis worldwide, primarily associated with the consumption of contaminated poultry. C. jejuni lineages vary in host range and prevalence in human infection, suggesting differences in survival throughout the poultry processing chain. From 7343 MLST‐characterised isolates, we sequenced 600 C. jejuni and C. coli isolates from various stages of poultry processing and clinical cases. A genome‐wide association study (GWAS) in C. jejuni ST‐21 and ST‐45 complexes identified genetic elements over‐represented in clinical isolates that increased in frequency throughout the poultry processing chain. Disease‐associated SNPs were distinct in these complexes, sometimes organised in haplotype blocks. The function of genes containing associated elements was investigated, demonstrating roles for cj1377c in formate metabolism, nuoK in aerobic survival and oxidative respiration, and cj1368‐70 in nucleotide salvage. This work demonstrates the utility of GWAS for investigating transmission in natural zoonotic pathogen populations and provides evidence that major C. jejuni lineages have distinct genotypes associated with survival, within the host specific niche, from farm to fork. 相似文献
179.
Bacterial α2-macroglobulins: colonization factors acquired by horizontal gene transfer from the metazoan genome?
下载免费PDF全文
![点击此处可从《Genome biology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Background
Invasive bacteria are known to have captured and adapted eukaryotic host genes. They also readily acquire colonizing genes from other bacteria by horizontal gene transfer. Closely related species such as Helicobacter pylori and Helicobacter hepaticus, which exploit different host tissues, share almost none of their colonization genes. The protease inhibitor α2-macroglobulin provides a major metazoan defense against invasive bacteria, trapping attacking proteases required by parasites for successful invasion. 相似文献180.
Liesbeth Van Der Velde Aidan K Curran James J Filiano Robert A Darnall Donald Bartlett J C Leiter 《Journal of applied physiology》2003,94(5):1883-1895
We tested the hypothesis that inhibition of neurons within the rostral ventral medulla (RVM) would prolong the laryngeal chemoreflex (LCR), a putative stimulus in the sudden infant death syndrome (SIDS). We studied the LCR in 19 piglets, age 3-16 days, by injecting 0.05 ml of saline or water into the larynx during wakefulness, non-rapid eye movement (NREM) sleep, and REM sleep, before and after 1 or 10 mM muscimol dialysis in the RVM. Muscimol prolonged the LCR (P < 0.05), and the prolongation was greater when the LCR was stimulated with water compared with saline (P < 0.02). The LCR was longer during NREM sleep than during wakefulness and longest during REM sleep (REM compared with wakefulness). Muscimol had no effect on the likelihood of arousal from sleep after LCR stimulation. We conclude that the RVM provides a tonic facilitatory drive to ventilation that limits the duration of the LCR, and loss of this drive may contribute to the SIDS when combined with stimuli that inhibit respiration. 相似文献