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91.
Bright Walker Arnold Tamayo Duc T. Duong Xuan‐Dung Dang Chunki Kim Jimmy Granstrom Thuc‐Quyen Nguyen 《Liver Transplantation》2011,1(2):221-229
The solubilities of 3,6‐bis(5‐(benzofuran‐2‐yl)thiophen‐2‐yl)‐2,5‐bis(2‐ethylhexyl)pyrrolo[3,4‐c]pyrrole‐1,4‐dione ( DPP(TBFu)2 ) and [6,6]‐phenyl‐C71‐butyric acid methyl ester ( PC71BM ) in a series of solvents are measured, and this data is used to calculate the Hansen solubility parameters of the two materials. The dispersion, polar, and H‐bonding parameters of DPP(TBFu)2 and PC71BM were found to be (19.3, 4.8, 6.3) and (20.2, 5.4, 4.5) MPa1/2, respectively, with an error of ± 0.8 MPa1/2. Based on the solubility properties of the two materials, three new solvents (thiophene, trichloroethylene and carbon disulfide) were utilized for the DPP(TBFu)2 : PC71BM system which, after device optimization, led to power conversion efficiencies up to 4.3%. 相似文献
92.
Jaime A. Ocampo‐Hernndez Fernando Tamayo‐Mejía Patricia Tamez‐Guerra Yulin Gao Ariel W. Guzmn‐Franco 《Journal of Applied Entomology》2019,143(9):984-991
Bactericera cockerelli (Sulc.) is a serious pest of solanaceous crops and a vector of the plant pathogen Candidatus Liberibacter psyllaurous. Entomopathogenic fungi are the most important biological control alternatives for this pest. Host plant species, however, can modify the outcomes of insect–pathogen interactions. We conducted laboratory experiments to quantify the virulence of two isolates of the entomopathogenic fungus Beauveria bassiana (Bals. [Vuill.]), BB40 and BB42, against third instar B. cockerelli nymphs maintained on chilli pepper plants. Owing to the lack of difference in virulence against B. cockerelli nymphs on chilli pepper between the two B. bassiana isolates, only BB42 was used to: compare virulence against nymphs maintained on either chilli pepper, potato or tomato; and in vivo conidia production from nymphs maintained on different host plants. Virulence of the two B. bassiana isolates against B. cockerelli nymphs was similar. Bactericera cockerelli nymphs maintained on tomato were more susceptible to B. bassiana than nymphs maintained on potato or chilli peppers. Infected nymphs maintained on chilli peppers produced the greatest number of conidia followed by infected nymphs maintained on tomato and potato. Host plant affected the susceptibility of B. cockerelli to B. bassiana isolate BB42 and subsequent conidia production. The implications of our results for microbial control of B. cockerelli by B. bassiana are discussed. 相似文献
93.
Advances in culture and genetic modification approaches to lipid biosynthesis for biofuel production and in silico analysis of enzymatic dominions in proteins related to lipid biosynthesis in algae 下载免费PDF全文
Yahaira J. Tamayo‐Ordóñez Benjamin A. Ayil‐Gutiérrez Felipe L. Sánchez‐Teyer Erika A. De la Cruz‐Arguijo Francisco A. Tamayo‐Ordóñez Atl Victor Córdova‐Quiroz Maria C. Tamayo‐Ordóñez 《Phycological Research》2017,65(1):14-28
Biofuels have been shown to be a promising and highly attractive alternative for minimizing the use of fossil fuels, and microalgae have positioned themselves as potential candidates for production of lipids and other substances of commercial interest. We briefly review recent advances made in microalgae culture conditions and genetic manipulation for improving lipid yields for biofuel production – with both approaches showing similar yields of triacylglycerides, indicating that more work is required for improving lipid yield and accumulation in algae. Aiming at gaining knowledge of algae genetic manipulation and exploring future use of this information for modifying the lipid biosynthesis pathway, we investigated whether some characteristics of enzymes involved in lipid biosynthesis could relate to lipid yield and accumulation in algae. We made an in silico analysis of amino acid sequence of enzymatic domains and modeled tertiary structure of three proteins involved in the biosynthesis of lipids in microalgae: acetyl‐CoA carboxylase, Acyl‐CoA: diacylglycerol acyltransferase, and glycerol‐3‐phosphate acyltransferase. Our results suggest that, based on primary amino acid sequences and tertiary structure of proteins shared by certain algae, it is likely that these proteins may relate to lipid yield and accumulation, which makes bioinformatics a powerful tool for in silico study of proteins and for selecting genes involved in lipid biosynthesis that could be useful for heterologous transformation in algae with the long term objective of improving their yield, accumulation, and fatty acid composition by genetic engineering. 相似文献
94.
Modification of cellular functions by overexpression of genes is being increasingly practiced for tissue engineering. In the present study, we investigated whether transfection efficiency could be enhanced by magnetofection that involves the use of plasmid DNA (pDNA)/magnetite cationic liposomes (MCLs) complexes (pDNA/MCL) and magnetic force. The transfection efficiencies of the magnetofection technique by pDNA/MCL in fibroblasts and keratinocytes using reporter genes were 36- and 10-fold higher, respectively, than those of a lipofection technique by cationic liposomes. Moreover, in vitro construction of three-dimensional (3D) tissues is an important challenge. We recently proposed a novel technique termed "magnetic force-based tissue engineering" (Mag-TE) to produce 3D tissues. Since the fibroblasts after magnetofection incorporated both magnetite nanoparticles and pDNA, we investigated whether multilayered heterotypic cell sheets expressing transgene could be fabricated by Mag-TE. First, the fibroblasts were seeded onto an ultra-low attachment culture plate. When a magnet was placed under the plate, the cells accumulated at the bottom of the culture plate. After 24 h of culture, the transgene-expressing cells formed a multilayered cell sheet-like structure. These results indicated that MCLs are a potent biomanipulation tool for both gene transfer and 3D tissue construction, suggesting that these techniques are useful for tissue engineering. 相似文献
95.
96.
Fernández JL Cartelle M Muriel L Santiso R Tamayo M Goyanes V Gosálvez J Bou G 《Applied and environmental microbiology》2008,74(19):5925-5933
Chromosomal DNA fragmentation may be a direct or indirect outcome of cell death. Unlike DNA fragmentation in higher eukaryotic cells, DNA fragmentation in microorganisms is rarely studied. We report an adaptation of a diffusion-based assay, developed as a kit, which allows for simple and rapid discrimination of bacteria with fragmented DNA. Intact cells were embedded in an agarose microgel on a slide, incubated in a lysis buffer to partially remove the cell walls, membranes, and proteins, and then stained with a DNA fluorochrome, SYBR Gold. Identifying cells with fragmented DNA uses peripheral diffusion of DNA fragments. Cells without DNA fragmentation show only limited spreading of DNA fiber loops. These results have been seen in several gram-negative and gram-positive bacteria, as well as in yeasts. Detection of DNA fragmentation was confirmed by fluoroquinolone treatment and by DNA breakage detection-fluorescence in situ hybridization. Proteus mirabilis with spontaneously fragmented DNA during exponential and stationary growth or Escherichia coli with DNA damaged after exposure to hydrogen peroxide or antibiotics, such as ciprofloxacin or ampicillin, was clearly detected. Similarly, fragmented DNA was detected in Saccharomyces cerevisiae after amphotericin B treatment. Our assay may be useful for the simple and rapid evaluation of DNA damage and repair as well as cell death, either spontaneous or induced by exogenous stimuli, including antimicrobial agents or environmental conditions. 相似文献
97.
Leila M. Reyes Ruiz Kathleen A. King Christian Agosto-Burgos Isabella S. Gamez Nicole C. Gadda Elizabeth M. Garrett Rita Tamayo 《PLoS pathogens》2022,18(7)
The opportunistic nosocomial pathogen Clostridioides difficile exhibits phenotypic heterogeneity through phase variation, a stochastic, reversible process that modulates expression. In C. difficile, multiple sequences in the genome undergo inversion through site-specific recombination. Two such loci lie upstream of pdcB and pdcC, which encode phosphodiesterases (PDEs) that degrade the signaling molecule c-di-GMP. Numerous phenotypes are influenced by c-di-GMP in C. difficile including cell and colony morphology, motility, colonization, and virulence. In this study, we aimed to assess whether PdcB phase varies, identify the mechanism of regulation, and determine the effects on intracellular c-di-GMP levels and regulated phenotypes. We found that expression of pdcB is heterogeneous and the orientation of the invertible sequence, or ‘pdcB switch’, determines expression. The pdcB switch contains a promoter that when properly oriented promotes pdcB expression. Expression is augmented by an additional promoter upstream of the pdcB switch. Mutation of nucleotides at the site of recombination resulted in phase-locked strains with significant differences in pdcB expression. Characterization of these mutants showed that the pdcB locked-ON mutant has reduced intracellular c-di-GMP compared to the locked-OFF mutant, consistent with increased and decreased PdcB activity, respectively. These alterations in c-di-GMP had concomitant effects on multiple known c-di-GMP regulated processes, indicating that phase variation of PdcB allows C. difficile to coordinately diversify multiple phenotypes in the population to enhance survival. 相似文献
98.
miRNA profiling of human naive CD4 T cells links miR‐34c‐5p to cell activation and HIV replication 下载免费PDF全文
99.