全文获取类型
收费全文 | 516篇 |
免费 | 46篇 |
出版年
2023年 | 3篇 |
2022年 | 6篇 |
2021年 | 10篇 |
2020年 | 11篇 |
2019年 | 4篇 |
2018年 | 18篇 |
2017年 | 6篇 |
2016年 | 11篇 |
2015年 | 17篇 |
2014年 | 18篇 |
2013年 | 26篇 |
2012年 | 31篇 |
2011年 | 31篇 |
2010年 | 14篇 |
2009年 | 24篇 |
2008年 | 33篇 |
2007年 | 21篇 |
2006年 | 19篇 |
2005年 | 15篇 |
2004年 | 21篇 |
2003年 | 19篇 |
2002年 | 20篇 |
2001年 | 13篇 |
2000年 | 18篇 |
1999年 | 20篇 |
1998年 | 11篇 |
1997年 | 9篇 |
1996年 | 3篇 |
1995年 | 4篇 |
1994年 | 4篇 |
1993年 | 5篇 |
1992年 | 5篇 |
1991年 | 7篇 |
1990年 | 3篇 |
1989年 | 5篇 |
1988年 | 8篇 |
1987年 | 4篇 |
1986年 | 8篇 |
1985年 | 4篇 |
1984年 | 5篇 |
1983年 | 3篇 |
1981年 | 3篇 |
1979年 | 4篇 |
1978年 | 4篇 |
1976年 | 2篇 |
1974年 | 6篇 |
1973年 | 2篇 |
1966年 | 2篇 |
1942年 | 2篇 |
1936年 | 2篇 |
排序方式: 共有562条查询结果,搜索用时 78 毫秒
61.
Pichler H Baumgartner S Freudenschuss M Palme S Binder EM Krska R 《Mycotoxin Research》2001,17(2):202-205
Enzyme-linked immunosorbent assays (ELISA) proved to be a fast and simple method for the detection of mycotoxins and other undesired contaminants in food and feed. The present study is focused on the optimisation and exploitation of the egg yolk antibody technology in order to develop competitive ELISAs for the detection of mycotoxins in cereals. Due to its importance as one of the most relevant Fusarium mycotoxins, the trichothecene deoxynivalenol (DON) was selected as representative. Chickens were immunised with different protein conjugates performing varying booster intervals. The antibodies were isolated by the poly(ethylene glycol) precipitation method according to Polson. By use of these antibodies an indirect competitive ELISA was developed for the detection of DON. First investigations of naturally contaminated wheat samples showed a good correspondence with results obtained by GC-ECD when calibration in blank wheat extracts was performed. 相似文献
62.
63.
Marc Stadler Manuela Baumgartner Klaus Ide Andreas Popp Hartmund Wollweber 《Mycological Progress》2002,1(1):31-42
Representative specimens of fifteen Daldinia spp. were studied for ultrastructural characteristics of their ascospores by scanning electron microscopy (SEM). The ornamentation
of their outermost spore layers was found to be species-consistent, confirming the results of concurrent studies on the morphology
of their teleomorphs and anamorphs, secondary metabolite profiles and PCR-based genetic fingerprints. Daldinia spp. may either show smooth or transversally striated ascospores. The spores of the species within the latter group are always
ellipsoid-equilateral to ellipsoid-inequilateral with narrowly rounded ends. Smooth, broadly ellipsoid to cylindrical ascospores
were observed in all species (D. caldariorum, D. fissa and D. loculata) that are known to produce their stromata on substrates damaged by fire. The ascospores of D. concentrica differed from those of D. childiae (i.e., the cosmopolitan taxon previously regarded as D. concentrica ss. auct.) and other Daldinia spp. in showing a very faint ornamentation, which only became visible at 10000× magnification by SEM. A specimen collected
on the isle of Jersey (Channel Islands, UK) showed morphological similarities to the pantropical D. eschscholzii, but its ascospores appeared smooth by SEM, and it may therefore represent a previously undescribed species.
Dedicated to Professor Yoshinori Asakawa, Tokushima, Japan, on the occasion of his 60th birthday
PH-R Life Science Center Natural Products 相似文献
64.
Shawn G Dunkirk Mark A Wallert Matt L Baumgartner Joseph J Provost 《Protein expression and purification》2002,24(1):1-12
A 66-kDa molecular weight protein with phospholipase D activity was solubilized and partially purified from rat liver plasma membrane. The activity and regulation of this phospholipase D have been characterized. Immunoblot analyses indicated that the enzyme was distinct from hPLD1 and PLD2, but was recognized by an antibody to the 12 terminal amino acids of PLD1. PLD activity was stimulated by 1-100 microM Ca(2+) and Mg(2+) and displayed a pH optimum of 7.5. Activity was inhibited by both saturated and unsaturated fatty acids. This PLD was activated in an ATP-independent manner by the PKC isozymes alpha and betaII but not activated by other PKC isozymes. It was also stimulated by the small G-proteins RhoA and ARF. RhoA stimulated the greatest activation, followed by ARF and PKC(alpha). This enzyme was further activated in a synergistic manner when combinations of PKC(alpha) and RhoA or ARF were used. This enzyme displayed a greater response activation by RhoA than to activation by ARF. While a potential breakdown product of PLD1, activation by RhoA indicates that the PLD characterized here is distinct from the other PLDs cloned or isolated to date. 相似文献
65.
Conrad J. Baumgartner 《The Western journal of medicine》1950,73(6):466-472
The embryonic origin of lateral cysts and fistulas remains controversial. They are, however, located in the general anatomic pattern of the embryonic thymic duct, which starts in the lateral pharyngeal wall and passes under the sternomastoid muscle to enter the mediastinum. The cyst is a unilocular, semiattached, non-translucent mass which has a tendency to become infected in 30 per cent of cases.The preauricular sinus occurs in front of the ear and is due either to a branchial cleft or an inclusion of one of the six primitive buds which form the external ear.Cystic hygroma is due to sequestrated lymphatic channels. These are always multilocular and rather invasive and may extend into mediastinum and arms.Diagnosis and treatment are considered in this presentation. 相似文献
66.
Diet and feeding habits of predatory fishes upstream and downstream of a low-level weir 总被引:2,自引:0,他引:2
L. J. Baumgartner 《Journal of fish biology》2007,70(3):879-894
A study investigating the influence of a low-level weir on the diets of three migratory percithyid species was undertaken on the Murrumbidgee River, Australia. A combination of fish community sampling and stomach flushing determined that Yanco Weir substantially impacted upon the abundance and feeding habits of golden perch Macquaria ambigua , Murray cod Maccullochella peelii peelii and trout cod Maccullochella macquariensis . The relative abundance of all three species was significantly greater downstream of the weir, where individuals attempting upstream migrations were obstructed. In areas of fish aggregations, some species displayed altered feeding strategies and exploited different prey taxa upstream and downstream of the weir. Diet overlap, and the proportion of individuals with empty stomachs, was also substantially greater from downstream zones. These results suggest that competition among species may be greater in areas of increased predator abundance and some species could be partitioning resources to minimize competitive interactions. Reducing accumulations of predatory species, by providing suitable fish passage facilities, would be an effective means to prevent such trophic interactions occurring at other low-level weirs. 相似文献
67.
68.
The Nck-interacting kinase NIK increases Arp2/3 complex activity by phosphorylating the Arp2 subunit
Lawrence L. LeClaire Manish Rana Martin Baumgartner Diane L. Barber 《The Journal of cell biology》2015,208(2):161-170
The nucleating activity of the Arp2/3 complex promotes the assembly of branched actin filaments that drive plasma membrane protrusion in migrating cells. Arp2/3 complex binding to nucleation-promoting factors of the WASP and WAVE families was previously thought to be sufficient to increase nucleating activity. However, phosphorylation of the Arp2 subunit was recently shown to be necessary for Arp2/3 complex activity. We show in mammary carcinoma cells that mutant Arp2 lacking phosphorylation assembled with endogenous subunits and dominantly suppressed actin filament assembly and membrane protrusion. We also report that Nck-interacting kinase (NIK), a MAP4K4, binds and directly phosphorylates the Arp2 subunit, which increases the nucleating activity of the Arp2/3 complex. In cells, NIK kinase activity was necessary for increased Arp2 phosphorylation and plasma membrane protrusion in response to epidermal growth factor. NIK is the first kinase shown to phosphorylate and increase the activity of the Arp2/3 complex, and our findings suggest that it integrates growth factor regulation of actin filament dynamics. 相似文献
69.
70.
The room temperature co-precipitation of ferrous and ferric iron under alkaline conditions typically yields superparamagnetic magnetite nanoparticles below a size of 20 nm. We show that at pH = 9 this method can be tuned to grow larger particles with single stable domain magnetic (> 20–30 nm) or even multi-domain behavior (> 80 nm). The crystal growth kinetics resembles surprisingly observations of magnetite crystal formation in magnetotactic bacteria. The physicochemical parameters required for mineralization in these organisms are unknown, therefore this study provides insight into which conditions could possibly prevail in the biomineralizing vesicle compartments (magnetosomes) of these bacteria. 相似文献