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711.
Central nervous system (CNS) diseases are difficult to treat because of the blood-brain barrier (BBB), which prevents most drugs from entering into the brain. Intranasal (IN) administration is a promising approach for drug delivery to the brain, bypassing the BBB; however, its application has been restricted to particularly potent substances and it does not offer localized delivery to specific brain sites. Focused ultrasound (FUS) in combination with microbubbles can deliver drugs to the brain at targeted locations. The present study proposed to combine these two different platform techniques (FUS+IN) for enhancing the delivery efficiency of intranasally administered drugs at a targeted location. After IN administration of 40 kDa fluorescently-labeled dextran as the model drug, FUS targeted at one region within the caudate putamen of mouse brains was applied in the presence of systemically administered microbubbles. To compare with the conventional FUS technique, in which intravenous (IV) drug injection is employed, FUS was also applied after IV injection of the same amount of dextran in another group of mice. Dextran delivery outcomes were evaluated using fluorescence imaging of brain slices. The results showed that FUS+IN enhanced drug delivery within the targeted region compared with that achieved by IN only. Despite the fact that the IN route has limited drug absorption across the nasal mucosa, the delivery efficiency of FUS+IN was not significantly different from that of FUS+IV. As a new drug delivery platform, the FUS+IN technique is potentially useful for treating CNS diseases. 相似文献
712.
Economic analysis of uricase production under uncertainty: Contrast of chromatographic purification and aqueous two‐phase extraction (with and without PEG recycle) 下载免费PDF全文
Mario A. Torres‐Acosta José M. Aguilar‐Yáñez Marco Rito‐Palomares Nigel J. Titchener‐Hooker 《Biotechnology progress》2016,32(1):126-133
Uricase is the enzyme responsible for the breakdown of uric acid, the key molecule leading to gout in humans, into allantoin, but it is absent in humans. It has been produced as a PEGylated pharmaceutical where the purification is performed through three sequential chromatographic columns. More recently an aqueous two‐phase system (ATPS) was reported that could recover Uricase with high yield and purity. Although the use of ATPS can decrease cost and time, it also generates a large amount of waste. The ability, therefore, to recycle key components of ATPS is of interest. Economic modelling is a powerful tool that allows the bioprocess engineer to compare possible outcomes and find areas where further research or optimization might be required without recourse to extensive experiments and time. This research provides an economic analysis using the commercial software BioSolve of the strategies for Uricase production: chromatographic and ATPS, and includes a third bioprocess that uses material recycling. The key parameters that affect the process the most were located via a sensitivity analysis and evaluated with a Monte Carlo analysis. Results show that ATPS is far less expensive than chromatography, but that there is an area where the cost of production of both bioprocesses overlap. Furthermore, recycling does not impact the cost of production. This study serves to provide a framework for the economic analysis of Uricase production using alternative techniques. © 2015 American Institute of Chemical Engineers Biotechnol. Prog., 32:126–133, 2016 相似文献
713.
We studied the diet of 50 individuals of Hyalella sp. collected in the karstic headwaters of a high‐altitude Andean river (3817 m a.s.l. Peru) in four different habitats: macrophytes, bryophytes, leaf litter, and layers of travertine. The gut content analysis showed a dominance of fine particulate organic matter (FPOM) in most habitats – layers of travertine (69.5%), Myriophylum (58.5%) and bryophytes (56.8%) – except for individuals collected in leaf litter where coarse particulate organic matter (CPOM) represented 68% of gut content, which indicates a high trophic flexibility of Hyalella sp. Likewise, in an experiment with feeding chambers in situ during three days, twenty individuals of Hyalella sp. presented a higher consumption of leaf litter of native species (Polylepis sp.) (0.025 mg/day) than those of an introduced species (Eucalyptus globulus) (0.008 mg/day). (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
714.
Bia D Pessana F Armentano R Pérez H Graf S Zócalo Y Saldías M Perez N Alvarez O Silva W Machin D Sueta P Ferrin S Acosta M Alvarez I 《Cell and tissue banking》2006,7(3):183-194
The viscoelastic and inertial properties of the arterial wall are responsible for the arterial functional role in the cardiovascular
system. Cryopreservation is widely used to preserve blood vessels for vascular reconstruction but it is controversially suspected
to affect the dynamic behaviour of these allografts. The aim of this work was to assess the cryopreservation's effects on
human arteries mechanical properties. Common carotid artery (CCA) segments harvested from donors were divided into two groups:
Fresh (n = 18), tested for 24–48 h after harvesting, and Cryopreserved (n = 18) for an average time of 30 days in gas-nitrogen phase, and finally defrosted. Each segment was tested in a circulation
mock, and its pressure and diameter were registered at similar pump frequency, pulse and mean pressure levels, including those
of normotensive and hipertensive conditions. A compliance transfer function (diameter/pressure) derived from a mathematical
adaptive modelling was designed for the on line assessment of the arterial wall dynamics and its frequency response. Assessment
of arterial wall dynamics was made by measuring its viscous (η), inertial (M) and elastic (E) properties, and creep and stress relaxation time constant (τC and τSR, respectively). The frequency response characterization allowed to evaluate the arterial wall filter or buffer function.
Results showed that non-significant differences exist between wall dynamics and buffer function of fresh and cryopreserved
segments of human CCA. In conclusion, our cryopreservation method maintains arterial wall functional properties, close to
their fresh values. 相似文献
715.
Environmental Implications of Resource Use:Environmental Input-Output Analyses for Germany 总被引:1,自引:0,他引:1
In a German case study, environmental input-output analyses (eIOA) combined with NAMEA-type tables were conducted for eleven selected environmental pressure variables. (NAMEA is an acronym for national accounts matrix including environmental accounts.) The analyses were conducted to derive the production-cycle-wide resource use and environmental impact potentials of final-demand product groups. The methodology permits identification and preliminary ranking of 10 product chains along which about two-thirds of German production-born environmental pressures arise. The most relevant product groups are construction work, food, motor vehicles, basic metals, and electricity. The ten product groups are characterized by both high resource requirements and high residual outputs (air emissions, wastes). The EU policy areas of integrated product policy and sustainable use of natural resources may address these product chains as a priority in order to identify and explore the possibility of reducing the environmental impacts from products throughout their life cycles and to decouple environmental impacts from resource use. 相似文献
716.
Acosta F Ellis AE Vivas J Padilla D Acosta B Déniz S Bravo J Real F 《Fish & shellfish immunology》2006,20(5):709-717
A virulent strain of Photobacterium damselae subsp. piscicida (Pdp) was grown without (C form) or with (C+ form) glucose supplementation, the latter to enhance capsule formation. Both forms were resistant to killing by normal serum of seabream, red porgy and seabass. However, the C form was killed by immune serum of all three fish species while the C+ form was killed only by seabream and red porgy sera and to a lesser extent than the C form. Both C and C+ forms consumed complement in normal serum and this consumption was enhanced by precoating the bacteria in specific fish antibody. Complement consumption was greatest in seabass serum, especially with antibody-coated C+ form yet in this case the bacteria were not killed. The killing of the C form in immune serum of all three fish species was completely inhibited by EGTA/Mg(2+), indicating that the mechanism of complement activation leading to killing of the bacteria was by the classical pathway. The results suggest that immune serum killing by the classical complement pathway may provide some degree of protection against pasteurellosis, but enhanced expression of the capsule by Pdp in vivo may restrict complement-mediated killing, especially in immunised seabass. 相似文献
717.
Vodovar N Vallenet D Cruveiller S Rouy Z Barbe V Acosta C Cattolico L Jubin C Lajus A Segurens B Vacherie B Wincker P Weissenbach J Lemaitre B Médigue C Boccard F 《Nature biotechnology》2006,24(6):673-679
Pseudomonas entomophila is an entomopathogenic bacterium that, upon ingestion, kills Drosophila melanogaster as well as insects from different orders. The complete sequence of the 5.9-Mb genome was determined and compared to the sequenced genomes of four Pseudomonas species. P. entomophila possesses most of the catabolic genes of the closely related strain P. putida KT2440, revealing its metabolically versatile properties and its soil lifestyle. Several features that probably contribute to its entomopathogenic properties were disclosed. Unexpectedly for an animal pathogen, P. entomophila is devoid of a type III secretion system and associated toxins but rather relies on a number of potential virulence factors such as insecticidal toxins, proteases, putative hemolysins, hydrogen cyanide and novel secondary metabolites to infect and kill insects. Genome-wide random mutagenesis revealed the major role of the two-component system GacS/GacA that regulates most of the potential virulence factors identified. 相似文献
718.
Fauqia Fahmeed Yaima Arocha Rosete Karel Acosta Pérez Eric Boa John Lucas 《Journal of Phytopathology》2009,157(10):639-641
Nearby fruit and vegetable fields in Islamabad, Pakistan were surveyed for phytoplasma infection. ' Candidatus Phytoplasma asteris' (Group 16SrI) was found infecting mango, citrus, loquat, geranium, periwinkle, radish, blackberry and potato. Results suggest that a polyphagous vector may be involved in phytoplasma transmission to these plant species, which are first host records of 16SrI phytoplasma infection in Pakistan. 相似文献
719.
720.
Ezeamama AE McGarvey ST Hogan J Lapane KL Bellinger DC Acosta LP Leenstra T Olveda RM Kurtis JD Friedman JF 《PLoS neglected tropical diseases》2012,6(5):e1634