全文获取类型
收费全文 | 717篇 |
免费 | 67篇 |
出版年
2022年 | 4篇 |
2021年 | 13篇 |
2019年 | 4篇 |
2018年 | 6篇 |
2017年 | 5篇 |
2016年 | 17篇 |
2015年 | 32篇 |
2014年 | 44篇 |
2013年 | 39篇 |
2012年 | 45篇 |
2011年 | 52篇 |
2010年 | 27篇 |
2009年 | 23篇 |
2008年 | 36篇 |
2007年 | 35篇 |
2006年 | 28篇 |
2005年 | 39篇 |
2004年 | 34篇 |
2003年 | 33篇 |
2002年 | 41篇 |
2001年 | 8篇 |
2000年 | 14篇 |
1999年 | 8篇 |
1998年 | 7篇 |
1997年 | 9篇 |
1996年 | 9篇 |
1995年 | 13篇 |
1994年 | 8篇 |
1993年 | 5篇 |
1992年 | 7篇 |
1990年 | 6篇 |
1988年 | 7篇 |
1987年 | 5篇 |
1986年 | 4篇 |
1985年 | 4篇 |
1984年 | 4篇 |
1983年 | 4篇 |
1978年 | 5篇 |
1976年 | 5篇 |
1974年 | 4篇 |
1973年 | 6篇 |
1969年 | 3篇 |
1968年 | 5篇 |
1965年 | 4篇 |
1964年 | 3篇 |
1963年 | 4篇 |
1962年 | 4篇 |
1960年 | 3篇 |
1959年 | 3篇 |
1949年 | 5篇 |
排序方式: 共有784条查询结果,搜索用时 31 毫秒
141.
Basic Domains Target Protein Subunits of the RNase MRP Complex to the Nucleolus Independently of Complex Association 总被引:6,自引:0,他引:6
下载免费PDF全文
![点击此处可从《Molecular biology of the cell》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Hans van Eenennaam Annemarie van der Heijden Rolf J. R. J. Janssen Walther J. van Venrooij Ger J. M. Pruijn 《Molecular biology of the cell》2001,12(11):3680-3689
The RNase MRP and RNase P ribonucleoprotein particles both function as endoribonucleases, have a similar RNA component, and share several protein subunits. RNase MRP has been implicated in pre-rRNA processing and mitochondrial DNA replication, whereas RNase P functions in pre-tRNA processing. Both RNase MRP and RNase P accumulate in the nucleolus of eukaryotic cells. In this report we show that for three protein subunits of the RNase MRP complex (hPop1, hPop4, and Rpp38) basic domains are responsible for their nucleolar accumulation and that they are able to accumulate in the nucleolus independently of their association with the RNase MRP and RNase P complexes. We also show that certain mutants of hPop4 accumulate in the Cajal bodies, suggesting that hPop4 traverses through these bodies to the nucleolus. Furthermore, we characterized a deletion mutant of Rpp38 that preferentially associates with the RNase MRP complex, giving a first clue about the difference in protein composition of the human RNase MRP and RNase P complexes. On the basis of all available data on nucleolar localization sequences, we hypothesize that nucleolar accumulation of proteins containing basic domains proceeds by diffusion and retention rather than by an active transport process. The existence of nucleolar localization sequences is discussed. 相似文献
142.
143.
Therese Pluess Vojtěch Jaro?ík Petr Py?ek Ray Cannon Jan Pergl Annemarie Breukers Sven Bacher 《PloS one》2012,7(10)
Although issues related to the management of invasive alien species are receiving increasing attention, little is known about which factors affect the likelihood of success of management measures. We applied two data mining techniques, classification trees and boosted trees, to identify factors that relate to the success of management campaigns aimed at eradicating invasive alien invertebrates, plants and plant pathogens. We assembled a dataset of 173 different eradication campaigns against 94 species worldwide, about a half of which (50.9%) were successful. Eradications in man-made habitats, greenhouses in particular, were more likely to succeed than those in (semi-)natural habitats. In man-made habitats the probability of success was generally high in Australasia, while in Europe and the Americas it was higher for local infestations that are easier to deal with, and for international campaigns that are likely to profit from cross-border cooperation. In (semi-) natural habitats, eradication campaigns were more likely to succeed for plants introduced as an ornamental and escaped from cultivation prior to invasion. Averaging out all other factors in boosted trees, pathogens, bacteria and viruses were most, and fungi the least likely to be eradicated; for plants and invertebrates the probability was intermediate. Our analysis indicates that initiating the campaign before the extent of infestation reaches the critical threshold, starting to eradicate within the first four years since the problem has been noticed, paying special attention to species introduced by the cultivation pathway, and applying sanitary measures can substantially increase the probability of eradication success. Our investigations also revealed that information on socioeconomic factors, which are often considered to be crucial for eradication success, is rarely available, and thus their relative importance cannot be evaluated. Future campaigns should carefully document socioeconomic factors to enable tests of their importance. 相似文献
144.
Reconstructions from serial sections reveal that the digestive system consists of a pharynx esophagus, crop, midgut, and rectum. Two main stems from the branched enteral diverticula are connected to the lateral regions of the crop by right rind left arms. Glandular tissue surrounds the enteral diverticula proximally. A strong sphincter separates the crop and midgut, whereas the midgut and rectum are separated by a weak sphincter. Cuboidal epithelium lines the pharynx, esophagus, crop, and rectum, whereas cuboidal and club-shaped epithelia line the midgut. The cuboidal cells possess elongated nuclei and numerous vacuoles, suggesting that absorption takes place in the midgut. 相似文献
145.
Grosser Annemarie Kundtner-Schwarzkopf Hanne Bernhauer Konrad 《Archives of microbiology》1950,15(2):236-246
Zusammenfassung Es wird gezeigt, daß sich die Farbstoffbildung der Penicillium-arten in recht erheblichem Ausmaß durch die Züchtungsbedingungen beeinflussen läßt. Bereits bei der vergleichenden Kultivierung der Pilze in der Oberflächen- und Submerskultur können auffallende Unterschiede beobachtet werden. Ferner konnte durch den Zusatz von Asparagin, Glutaminsäure und Zinksulfat besonders in der Submerskultur die Farbstoffbildung recht erheblich geändert werden. Dabei verhielten sich allerdings die einzelnen Pilze individuell außerordentlich verschieden, so daß keine allgemein gültigen Gesetzmäßigkeiten über die Beeinflußbarkeit des Prozesses abgeleitet werden können. Wohl aber können bestimmte Typen von Fällen aufgestellt werden, denen jeweils eine Reihe von Penicillien zuzuordnen ist.Aus dem vormaligen Institut für Biochemie u. Nahrungsmittelchemie der Deutschen Technischen Hochschule in Prag. — Vgl. auch Diplom-Arbeit H. Kundtner, Prag, März 1945. 相似文献
146.
Annemarie Toth 《Protoplasma》1951,40(1):187-194
Zusammenfassung Die festen Anthocyanausfällungen im Blütenblatt vonPelargonium zonale Meteor wurden auf ihre physikalischen und chemischen Eigenschaften geprüft.Mit Hilfe des Mikromanipulators konnte festgestellt werden, daß es sich um eine spröde, aber auch irgendwie zähe homogene Masse handelt, die der Nadel ausweicht und, einmal angestochen, in Teilstücke mit zackigem Bruch zerfällt, wobei keine Spur von Farbstoff austritt. Zellsaft von kugellosen Zellen entmischt sich beim Austritt aus der Zelle, während der Zellsaft kugelhältiger Zellen diese Entmischung nicht gibt,Die Frage, ob das feste Anthocyan, abgesehen von seinem Aggregatzustand, mit dem in der Zelle gelösten vollkommen übereinstimmt, muß auf Grund der mikrochemischen Untersuchungen verneint werden. Das Anthocyan der schwarzroten Kugeln zeigt andere chemische Eigenschaften als das im Zellsaft gelöste.Das Verhalten der Kugeln in HNO3 und Millons Reagens läßt annehmen, daß das Anthocyan hier an einen eiweißreichen Grundkörper gebunden ist. Man könnte dann auch in diesem Falle wie beiGunnera undErythraea von Anthocyanophoren sprechen. 相似文献
147.
Annemarie Samuels 《The journal of the Royal Anthropological Institute》2016,22(4):809-825
The devastating Indian Ocean tsunami of 26 December 2004 caused massive destruction to coastal Aceh, Indonesia, and left countless numbers of people dead or wounded. This article focuses on the embodied narratives of three Acehnese women who survived the disaster and, like many others in Aceh, told their stories ‘through’ their bodies. A detailed ethnographic account of their narratives reveals how the body stretches temporally between the ‘narrated event’ and the ‘narrative event’, both through the representation of the body in narratives and through the embodied performance of narratives. Moving beyond meaning‐centred analyses of narratives, I argue that the central accomplishment of these narratives is that they convey poignant bodily experiences to others and thereby create a shared, post‐disaster, world. Ultimately, through these embodied narratives of disaster people remake their world, with others, in the wake of its ‘unmaking’. 相似文献
148.
Numerical abundance and biodiversity of below-ground taxocenes along a pH gradient across the Netherlands 总被引:8,自引:0,他引:8
Christian Mulder Harm J. Van Wijnen Annemarie P. Van Wezel 《Journal of Biogeography》2005,32(10):1775-1790
Aim Taxocenes are regulated by different kinds of predictors, but can broad‐scale patterns of prokaryotes (bacteria) and eukaryotes (such as fungi and invertebrates) be ascribed to soil acidity? We sought to test for relationships between the numerical abundances of bacteria, microfungi, nematodes and arthropods along a pH gradient. Location 284 agro‐ecosystems on Pleistocene sand across the Netherlands. Methods Generalized Linear Models (GLM) and stepwise regressions were applied, using soil‐ and leaf‐litter organisms sampled from a land‐cover network. Results The major variation in the numerical abundance of the organisms belonging to the investigated taxocenes could be ascribed to soil acidity. Contrary to expectations, the effects of temperature on numerical abundance were significant only for Fungi and Nematoda (P < 0.0001). Geographical co‐ordinates always play a minor role. The often‐suggested close correlation between the numerical abundance of eukaryotes and their local taxonomic diversity applied only to Arthropoda and Fungi (P < 0.00001). Only the number of bacterial DNA bands seemed to reflect the taxa–area relationship (F‐value = 22.45, P < 0.0001). Main conclusions There were strong relationships between the numerical abundances of all the investigated taxocenes and the field‐measured soil acidity (P < 0.0001). The largest effects were detected in the Fungi, which tended to be much more acid‐tolerant than Bacteria. These patterns imply ecological shifts in the detrital soil food web and deserve further investigation. 相似文献
149.
150.
Machielsen R Leferink NG Hendriks A Brouns SJ Hennemann HG Daussmann T van der Oost J 《Extremophiles : life under extreme conditions》2008,12(4):587-594
There is considerable interest in the use of enantioselective alcohol dehydrogenases for the production of enantio- and diastereomerically
pure diols, which are important building blocks for pharmaceuticals, agrochemicals and fine chemicals. Due to the need for
a stable alcohol dehydrogenase with activity at low-temperature process conditions (30°C) for the production of (2S,5S)-hexanediol,
we have improved an alcohol dehydrogenase from the hyperthermophilic archaeon Pyrococcus furiosus (AdhA). A stable S-selective alcohol dehydrogenase with increased activity at 30°C on the substrate 2,5-hexanedione was generated
by laboratory evolution on the thermostable alcohol dehydrogenase AdhA. One round of error-prone PCR and screening of ∼1,500
mutants was performed. The maximum specific activity of the best performing mutant with 2,5-hexanedione at 30°C was tenfold
higher compared to the activity of the wild-type enzyme. A 3D-model of AdhA revealed that this mutant has one mutation in
the well-conserved NADP(H)-binding site (R11L), and a second mutation (A180V) near the catalytic and highly conserved threonine
at position 183. 相似文献