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21.
Ifey Alio Mirja Gudzuhn Pablo Pérez García Dominik Danso Marie Charlotte Schoelmerich Uwe Mamat Ulrich E. Schaible J?rg Steinmann Daniel Yero Isidre Gibert Thomas A. Kohl Stefan Niemann Matthias I. Gr?schel Johanna Haerdter Thomas Hackl Christel Vollstedt Mechthild B?meke Richard Egelkamp Rolf Daniel Anja Poehlein Wolfgang R. Streit 《Applied and environmental microbiology》2020,86(24)
22.
Kathleen B?rner Dominik Niopek Gabriella Cotugno Michaela Kaldenbach Teresa Pankert Joschka Willemsen Xian Zhang Nina Schürmann Stefan Mockenhaupt Andrius Serva Marie-Sophie Hiet Ellen Wiedtke Mirco Castoldi Vytaute Starkuviene Holger Erfle Daniel F. Gilbert Ralf Bartenschlager Michael Boutros Marco Binder Konrad Streetz Hans-Georg Kr?usslich Dirk Grimm 《Nucleic acids research》2013,41(21):e199
As the only mammalian Argonaute protein capable of directly cleaving mRNAs in a small RNA-guided manner, Argonaute-2 (Ago2) is a keyplayer in RNA interference (RNAi) silencing via small interfering (si) or short hairpin (sh) RNAs. It is also a rate-limiting factor whose saturation by si/shRNAs limits RNAi efficiency and causes numerous adverse side effects. Here, we report a set of versatile tools and widely applicable strategies for transient or stable Ago2 co-expression, which overcome these concerns. Specifically, we engineered plasmids and viral vectors to co-encode a codon-optimized human Ago2 cDNA along with custom shRNAs. Furthermore, we stably integrated this Ago2 cDNA into a panel of standard human cell lines via plasmid transfection or lentiviral transduction. Using various endo- or exogenous targets, we demonstrate the potential of all three strategies to boost mRNA silencing efficiencies in cell culture by up to 10-fold, and to facilitate combinatorial knockdowns. Importantly, these robust improvements were reflected by augmented RNAi phenotypes and accompanied by reduced off-targeting effects. We moreover show that Ago2/shRNA-co-encoding vectors can enhance and prolong transgene silencing in livers of adult mice, while concurrently alleviating hepatotoxicity. Our customizable reagents and avenues should broadly improve future in vitro and in vivo RNAi experiments in mammalian systems. 相似文献
23.
Degradation kinetics of biochar from pyrolysis and hydrothermal carbonization in temperate soils 总被引:2,自引:0,他引:2
Mo Bai Burkhard Wilske Franz Buegger Jürgen Esperschütz Claudia Irene Kammann Christian Eckhardt Martin Koestler Philipp Kraft Martin Bach Hans-Georg Frede Lutz Breuer 《Plant and Soil》2013,372(1-2):375-387
Background and Aims
Estimates of biochar residence times in soils range over three orders of magnitude. We present the first direct comparison between the biodegradation of a char from hydrothermal carbonization (htcBC) and pyrolysis (pyrBC) with high temporal resolution.Methods
Mineralization of the biochars and their shared Miscanthus feedstock in three soils was determined directly by the 13CO2 efflux using a novel method incorporating wavelength scanned cavity ring-down spectroscopy. Biochar half-life (t1/2) was estimated with three empirical models.Results
(1) The htcBC was readily biodegradable, whereas pyrBC was more recalcitrant. (2) Cumulative degradation of both biochars increased with soil organic carbon and nitrogen content. (3) The corrected Akaike information criterion (AICC) showed an overall preference for the double exponential model (DEM) reflecting a labile and a recalcitrant C-pool, over the first-order degradation model (FODM) and a logarithmic model. (4) The DEM resulted in t1/2 ranging from 19.7–44.5, 0.7–2.1 and 0.8–1.3 years for pyrBC, htcBC and feedstock, respectively.Conclusion
The degradation was rather similar between feedstock and htcBC but one order of magnitude slower for pyrBC. The AICC preferred FODM in two cases, where the DEM parameters indicated no distinction between a labile and recalcitrant carbon pool. 相似文献24.
Gary Strobel Eric Booth George Schaible Morgan Tess Mends Joe Sears Brad Geary 《Biotechnology letters》2013,35(4):539-552
The construction and testing of a unique instrument, the Paleobiosphere, which mimics some of the conditions of the ancient earth, is described. The instrument provides an experimental testing system for determining if certain microbes, when provided an adequate environment, can degrade biological materials to produce fuel-like hydrocarbons in a relatively short time frame that become trapped by the shale. The conditions selected for testing included a particulate Montana shale (serving as the “Trap Shale”), plant materials (leaves and stems of three extant species whose origins are in the late Cretaceous), a water-circulating system, sterile air, and a specially designed Carbotrap through which all air was passed as exhaust and volatile were hydrocarbons trapped. The fungus for initial testing was Annulohypoxylon sp., isolated as an endophyte of Citrus aurantifolia. It produces, in solid and liquid media, a series of hydrocarbon-like molecules. Some of these including 1,8-cineole, 2-butanone, propanoic acid, 2-methyl-, methyl ester, benzene (1-methylethyl)-, phenylethyl alcohol, benzophenone and azulene, 1,2,3,5,6,7,8,8a-octahydro-1,4-dimethyl-7-(1-methylethenyl), [1S-(1α,7α,8aβ)]. These were the key signature compounds used in an initial Paleobiosphere test. After 3 weeks, incubation, the volatiles associated with the harvested “Trap Shale” included each of the signature substances as well as other fungal-associated products: some indanes, benzene derivatives, some cyclohexanes, 3-octanone, naphthalenes and others. The fungus thus produced a series of “Trap Shale” products that were representative of each of the major classes of hydrocarbons in diesel fuel (Mycodiesel). Initial tests with the Paleobiosphere offer some evidence for a possible origin of hydrocarbons trapped in bentonite shale. Thus, with modifications, numerous other tests can also be designed for utilization in the Paleobiosphere. 相似文献
25.
26.
Unlike humans, certain adult vertebrates such as newts and zebrafish possess extraordinary abilities to functionally regenerate lost appendages and injured organs, including cardiac muscle. Here, we present new evidence that a remodeled extracellular matrix (ECM) directs cell activities essential for cardiac muscle regeneration. Comprehensive mining of DNA microarrays and Gene Ontology term enrichment analyses for regenerating newt and zebrafish hearts revealed that distinct ECM components and ECM-modifying proteases are among the most significantly enriched genes in response to local injury. In contrast, data analyses for mammalian cardiac injury models indicated that inflammation and metabolic processes are the most significantly activated gene groups. In the regenerating newt heart, we show dynamic spatial and temporal changes in tenascin-C, hyaluronic acid, and fibronectin ECM distribution as early as 3 days postamputation. Linked to distinct matrix remodeling, we demonstrate a myocardium-wide proliferative response and radial migration of progenitor cells. In particular, we report dramatic upregulation of a regeneration-specific matrix in the epicardium that precedes the accumulation and migration of progenitor cells. For the first time, we show that the regenerative ECM component tenascin-C significantly increases newt cardiomyocyte cell cycle reentry in vitro. Thus, the engineering of nature-tested extracellular matrices may provide new strategic opportunities for the enhancement of regenerative responses in mammals. 相似文献
27.
The global trade in ornamental fish involves c. 125 countries worldwide and is worth c. US $15–30 billion each year. This total is dominated (90%) by freshwater fishes, most of which are sourced from breeding facilities located in developing countries, typically in Asia or South America, but also in Israel, USA and Europe. Some fish are still obtained from natural (wild) sources, but the exact percentage of wild-caught fish is difficult to quantify given a lack of reliable data. Although c. 1000 species of freshwater fishes are widely available (from a total of > 5300 on sale), the most dominant freshwater fishes in the market comprise only 30 species from the orders Cyprinodontiformes, Perciformes, Characiformes and Siluriformes. In this perspectives review paper, illustrative example case studies of wild-fish collecting (Barcelos and Rio Xingu, Brazil) and breeding projects (Java, Indonesia) are described. In addition, wild-collecting expeditions to West Papua, Indonesia are discussed, focused on discovering novel species of rainbowfish (Melanotaeniidae) for breeding in captivity. Sustainability of the aquarium industry is considered in its broadest sense. The aquarium industry has been portrayed as both a major threat to natural ecosystems, but also as being part of the solution in terms of helping to maintain species when they have gone extinct in the wild or offering an income to impoverished citizens who might otherwise engage in much more destructive practices. 相似文献
28.
Exclusion of galectin 9 as a candidate gene for hyperuricosuria in the Dalmatian dog 总被引:2,自引:0,他引:2
All Dalmatian dogs have an inherited defect in purine metabolism leading to high levels of uric acid excretion in their urine (hyperuricosuria) rather than allantoin, the normal end product of purine metabolism in all other breeds of dog. Transplantation experiments have demonstrated that the defect is intrinsic to the liver and not the kidney. Uricase, the enzyme involved in the breakdown of urate into allantoin, has been shown to function in Dalmatian liver cells. Therefore, candidate genes for this defect include transporters of urate, a salt of uric acid, across cell membranes. We excluded one such urate transporter candidate, galectin 9, using a Dalmatian x Pointer backcross in which hyperuricosuria was segregating. 相似文献
29.
The pancreatic amylase (AMY2, E.C. 3.2.1.1) polymorphism has been studied in 2346 individuals from south-central and south-eastern Bulgaria. The allele frequencies have been determined as AMY2*1 = 0.9520 and AMY2*2 = 0.0480. The neighbor joining tree of seven subpopulations revealed only small genetic distances. Compared with other populations, the Bulgarian sample clustered with samples from Romania, Hungary, Germany and Switzerland, with larger distances to Albania, Greece and Macedonia. 相似文献
30.
Pep5 is a cationic pore-forming lantibiotic produced by Staphylococcus epidermidis strain 5. The producer strain protects itself from the lethal action of its own bacteriocin through the 69-amino-acid immunity peptide PepI. The N-terminal segment of PepI contains a 20-amino-acid stretch of apolar residues, whereas the C terminus is very hydrophilic, with a net positive charge. We used green fluorescent protein (GFP)-PepI fusions to obtain information on its localization in vivo. PepI was found to occur outside the cytoplasm and to accumulate at the membrane-cell wall interface. The extracellular localization appeared essential for conferring immunity. We analyzed the functional role of the specific segments by constructing various mutant peptides, which were also fused to GFP. When the hydrophobic N-terminal segment of PepI was disrupted by introducing charged amino acids, the export of PepI was blocked and clones expressing such mutant peptides were Pep5 sensitive. When PepI was successively shortened at the C terminus, in contrast, its export properties remained unchanged whereas its ability to confer immunity was gradually reduced. The results show that the N-terminal part is required for the transport of PepI and that the C-terminal part is important for conferring the immunity phenotype. A concept based on target shielding is proposed for the PepI immunity mechanism. 相似文献