全文获取类型
收费全文 | 245篇 |
免费 | 15篇 |
出版年
2017年 | 2篇 |
2016年 | 6篇 |
2015年 | 8篇 |
2014年 | 7篇 |
2013年 | 5篇 |
2012年 | 10篇 |
2011年 | 9篇 |
2010年 | 10篇 |
2009年 | 9篇 |
2008年 | 19篇 |
2007年 | 8篇 |
2006年 | 5篇 |
2005年 | 9篇 |
2004年 | 5篇 |
2003年 | 8篇 |
2002年 | 13篇 |
2001年 | 9篇 |
2000年 | 14篇 |
1999年 | 7篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1993年 | 4篇 |
1992年 | 4篇 |
1991年 | 7篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1987年 | 6篇 |
1986年 | 8篇 |
1985年 | 8篇 |
1984年 | 7篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 4篇 |
1979年 | 1篇 |
1977年 | 4篇 |
1976年 | 2篇 |
1974年 | 1篇 |
1973年 | 2篇 |
1972年 | 4篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1966年 | 2篇 |
1965年 | 1篇 |
排序方式: 共有260条查询结果,搜索用时 31 毫秒
241.
Structure of von Willebrand factor-cleaving protease (ADAMTS13), a metalloprotease involved in thrombotic thrombocytopenic purpura 总被引:32,自引:0,他引:32
Zheng X Chung D Takayama TK Majerus EM Sadler JE Fujikawa K 《The Journal of biological chemistry》2001,276(44):41059-41063
Thrombotic thrombocytopenic purpura is associated with acquired or congenital deficiency of a plasma von Willebrand factor-cleaving protease (VWFCP). Based on partial amino acid sequence, VWFCP was identified recently as a new member of the ADAMTS family of metalloproteases and designated ADAMTS13. The 4.6-kilobase pair cDNA sequence for VWFCP has now been determined. By Northern blotting, full-length VWFCP mRNA was detected only in liver. VWFCP consists of 1427 amino acid residues and has a signal peptide, a short propeptide terminating in the sequence RQRR, a reprolysin-like metalloprotease domain, a disintegrin-like domain, a thrombospondin-1 repeat, a Cys-rich domain, an ADAMTS spacer, seven additional thrombospondin-1 repeats, and two CUB domains. VWFCP apparently is made as a zymogen that requires proteolytic activation, possibly by furin intracellularly. Sites for Zn(2+) and Ca(2+) ions are conserved in the protease domain. The Cys-rich domain contains an RGDS sequence that could mediate integrin-dependent binding to platelets or other cells. Alternative splicing gives rise to at least seven potential variants that truncate the protein at different positions after the protease domain. Alternative splicing may have functional significance, producing proteins with distinct abilities to interact with cofactors, connective tissue, platelets, and von Willebrand factor. 相似文献
242.
Djie Tjwan Thung Joep de Ligt Lisenka EM Vissers Marloes Steehouwer Mark Kroon Petra de Vries Eline P Slagboom Kai Ye Joris A Veltman Jayne Y Hehir-Kwa 《Genome biology》2014,15(10)
Mobile elements are major drivers in changing genomic architecture and can cause disease. The detection of mobile elements is hindered due to the low mappability of their highly repetitive sequences. We have developed an algorithm, called Mobster, to detect non-reference mobile element insertions in next generation sequencing data from both whole genome and whole exome studies. Mobster uses discordant read pairs and clipped reads in combination with consensus sequences of known active mobile elements. Mobster has a low false discovery rate and high recall rate for both L1 and Alu elements. Mobster is available at http://sourceforge.net/projects/mobster.
Electronic supplementary material
The online version of this article (doi:10.1186/s13059-014-0488-x) contains supplementary material, which is available to authorized users. 相似文献243.
Marie-Aurélie Bruno Audrey Vanhaudenhuyse Caroline Schnakers Mélanie Boly Olivia Gosseries Athena Demertzi Steve Majerus Gustave Moonen Roland Hustinx Steven Laureys 《BMC neurology》2010,10(1):35
Background
Assessment of visual fixation is commonly used in the clinical examination of patients with disorders of consciousness. However, different international guidelines seem to disagree whether fixation is compatible with the diagnosis of the vegetative state (i.e., represents "automatic" subcortical processing) or is a sufficient sign of consciousness and higher order cortical processing.Methods
We here studied cerebral metabolism in ten patients with chronic post-anoxic encephalopathy and 39 age-matched healthy controls. Five patients were in a vegetative state (without fixation) and five presented visual fixation but otherwise showed all criteria typical of the vegetative state. Patients were matched for age, etiology and time since insult and were followed by repeated Coma Recovery Scale-Revised (CRS-R) assessments for at least 1 year. Sustained visual fixation was considered as present when the eyes refixated a moving target for more than 2 seconds as defined by CRS-R criteria.Results
Patients without fixation showed metabolic dysfunction in a widespread fronto-parietal cortical network (with only sparing of the brainstem and cerebellum) which was not different from the brain function seen in patients with visual fixation. Cortico-cortical functional connectivity with visual cortex showed no difference between both patient groups. Recovery rates did not differ between patients without or with fixation (none of the patients showed good outcome).Conclusions
Our findings suggest that sustained visual fixation in (non-traumatic) disorders of consciousness does not necessarily reflect consciousness and higher order cortical brain function.244.
A fast, cost-efficient, sensitive and accurate assay method for zearalenone in edible oils is described, as an alternative
to gel permeation chromatography (GPC). Oil samples were extracted with an alkaline mixture of methanol and water (methanol
+10 g/l aqueous ammonium carbaminate solution, pH 9; 9 + 1, v+v). The pH of the extract was neutralized with hydrochloric
acid and then concentrated to dryness. The residue was dissolved with HPLC solvent, and zearalenone was determined by high-performance
liquid chromatography with fluorometric detection (HPLC-FLD). The method was successfully validated for two matrices, maize
oil and rapeseed oil. The recovery rate was 87%, and the coefficient of variation was 2.8% in a rapeseed oil sample contaminated
with 27 μg zearalenone/kg. At a signal-to-noise ratio of 3:1, the method detection limit was 10 μg/kg, which was considered
to be adequate in view of the present European Union maximum level of 400 μg/kg. 相似文献
245.
Iron toxicity occurs under flooded conditions such as those prevailing in lowland rice fields and is due to an excess of ferrous ions. Ferritin is a multimeric protein responsible for Fe sequestration and storage, playing a key role in Fe homeostasis. Our aim was to study the modalities of overall ferritin synthesis in different organs of young seedlings from the African rice species (Oryza glaberrima) in relation to the putative involvement of abscisic acid (ABA) and oxidative stress in signalling processes. Seedlings from a moderately resistant to iron toxicity cultivar were grown in hydroponic culture for 2 weeks and treated with 500 mg l?1 Fe2+ in the presence or in the absence of 200?µM ABA, 50?µM methylviologen or 50?µM fluridone. Iron treatment increased iron and malondialdehyde concentration in all organs as well as ABA in roots and laminae. Although ferritin protein was detected in controls plants, iron treatment strongly reinforced its accumulation in sheaths and laminae after 24 h and 72 h. Ferritin mRNA was induced as early as 24 h after the beginning of the Fe-treatment in sheaths and, to a higher extent, in laminae. In the absence of iron treatment, exogenous ABA increased ferritin mRNA in laminae only but did not lead to further ferritin accumulation. Unexpectedly, it decreased ferritin mRNA levels in the sheaths of iron-treated plants and may thus have a dual influence depending on the considered organ. The inhibitor of ABA synthesis fluridone reduced endogenous ABA but did not compromise ferritin gene expression or ferritin synthesis, whatever the iron dose. Methyviologen application induced obvious oxidative damages but reduced ferritin synthesis. It is suggested that the signalling pathway leading to ferritin synthesis in the semi-aquatic African rice species may involve other components than those reported for typical terrestrial plants. 相似文献
246.
Male-killing endosymbionts have been widely reported in the invertebrates and are highly prevalent in the Coccinellidae. The
presence of male-killers can lead to extreme bias in host population sex ratios and may have important and far-reaching consequences
for the life-history and evolution of their hosts. Male-killers may have direct and indirect effects on host fitness and reproductive
behaviour, as well as affecting the host genome, either via strong selection pressure imposed by highly female-biased population
sex ratios or by selective sweeps caused as a male-killer conferring an advantage to infected individuals spreads through
a population. Criteria used to predict which species are liable to male-killer invasion, based on a variety of ecological
factors, have been produced. In summary male-killers are predicted to occur in aphidophageous species, that lay eggs in clutches,
show sibling egg consumption and are liable to neonatal larval mortality due to starvation. We assayed 30 species of Coccinellid
for the presence of such male-killers to assess the predictive accuracy of the criteria. Male-killers were identified in 8
species in which they were predicted to occur and were absent from all 10 species predicted not to harbor them. Analysis of
the remaining 12 species, where male-killers were predicted by the original criteria, but where they were not found, allowed
us to identify areas where the criteria can be refined and improved. We conclude that whilst the original criteria give a
reasonably accurate prediction, there are refinements and improvements, concerning details of host diet and life-history,
which make them more robust, especially in the light of discoveries of male-killing suppressors and when incorporated give
a better fit to our findings from field samples. 相似文献
247.
K van Oers A W Santure I De Cauwer N EM van Bers R PMA Crooijmans B C Sheldon M E Visser J Slate M AM Groenen 《Heredity》2014,112(3):307-316
Linking variation in quantitative traits to variation in the genome is an important, but
challenging task in the study of life-history evolution. Linkage maps provide a valuable
tool for the unravelling of such trait−gene associations. Moreover, they give
insight into recombination landscapes and between-species karyotype evolution. Here we
used genotype data, generated from a 10k single-nucleotide polymorphism (SNP) chip, of
over 2000 individuals to produce high-density linkage maps of the great tit (Parus
major), a passerine bird that serves as a model species for ecological and
evolutionary questions. We created independent maps from two distinct populations: a
captive F2-cross from The Netherlands (NL) and a wild population from the United Kingdom
(UK). The two maps contained 6554 SNPs in 32 linkage groups, spanning 2010 cM and
1917 cM for the NL and UK populations, respectively, and were similar in size and
marker order. Subtle levels of heterochiasmy within and between chromosomes were
remarkably consistent between the populations, suggesting that the local departures from
sex-equal recombination rates have evolved. This key and surprising result would have been
impossible to detect if only one population was mapped. A comparison with zebra finch
Taeniopygia guttata, chicken Gallus gallus and the green anole lizard
Anolis carolinensis genomes provided further insight into the evolution of
avian karyotypes. 相似文献
248.
We have previously shown that aspirin irreversibly inhibits prostaglandin synthetase (cyclo-oxygenase) by acetylating the active site of the enzyme. By utilizing 14C-labeled indomethacin and a close analogue, we now show that indomethacin, unlike aspirin, does not covalently modify cyclo-oxygenase. Furthermore, indomethacin binding to the enzyme may be reversible since even though indomethacin can inhibit acetylation by aspirin, when enzyme inhibited by indomethacin (1 micronM) is treated with 200 micronM aspirin 3 times for 1 hour each, complete acetylation of cyclo-oxygenase is achieved. 相似文献
249.