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排序方式: 共有174条查询结果,搜索用时 281 毫秒
81.
Jssyca BandeiraCorrêa Brbara PezziniMoreira Larissa Lohmanm Lucas MachadoSulzbacher Analú BenderdosSantos Antonieta Ruiz Mirna StelaLudwig Gabriela Elisa Hirsch Cledir Santos Ilaine Teresinha SeibelGehrke Thiago GomesHeck 《化学与生物多样性》2019,16(1)
Schinus lentiscifolius Marchand has been used in folk medicine to treat immunoinflammatory related diseases, which are marked by OS and altered HSR. Our study aimed to evaluate OS and HSR in lymphocytes treated with S. lentiscifolius bark extracts. S. lentiscifolius barks were partitioned with solvents to obtain hexane (SL‐HEX), ethyl acetate (SL‐ACOET) and methanol (SL‐MEOH) extracts, and the presence of bioactive compounds was evaluated by thin layer chromatography. Total phenols were measured by the Folin–Ciocalteu method and flavonoids were identified by HPLC‐DAD‐ESI‐MS/MS. Antioxidant capacity was verified by DPPH method, cell viability by Trypan Blue method, lipid peroxidation by TBARS and HSP70 by immunoblotting. The SL‐ACOET extract presented higher content of phenolic compounds and antioxidant activity in vitro. It was able to reduce lipid peroxidation levels in lymphocytes induced by H2O2 and improved cell viability. The SL‐ACOET extract inhibited HSR by a decrease in both intracellular content and release of 70 kDa heat shock proteins (HSP70) and also by decrease extra‐to‐intracellular HSP70 ratio in lymphocytes submitted to heat shock (2 h, 41 °C). S. lentiscifolius bark extract has antioxidant activity and inhibitory effect on HSR probably due to the presence of polyphenols as the flavonoids quercetin and kaempferol. 相似文献
82.
Ibrahim M. Moustafa Victoria K. Korboukh Jamie J. Arnold Eric D. Smidansky Laura L. Marcotte David W. Gohara Xiaorong Yang María Antonieta Sánchez-Farrán David Filman Janna K. Maranas David D. Boehr James M. Hogle Coray M. Colina Craig E. Cameron 《The Journal of biological chemistry》2014,289(52):36229-36248
RNA viruses encoding high- or low-fidelity RNA-dependent RNA polymerases (RdRp) are attenuated. The ability to predict residues of the RdRp required for faithful incorporation of nucleotides represents an essential step in any pipeline intended to exploit perturbed fidelity as the basis for rational design of vaccine candidates. We used x-ray crystallography, molecular dynamics simulations, NMR spectroscopy, and pre-steady-state kinetics to compare a mutator (H273R) RdRp from poliovirus to the wild-type (WT) enzyme. We show that the nucleotide-binding site toggles between the nucleotide binding-occluded and nucleotide binding-competent states. The conformational dynamics between these states were enhanced by binding to primed template RNA. For the WT, the occluded conformation was favored; for H273R, the competent conformation was favored. The resonance for Met-187 in our NMR spectra reported on the ability of the enzyme to check the correctness of the bound nucleotide. Kinetic experiments were consistent with the conformational dynamics contributing to the established pre-incorporation conformational change and fidelity checkpoint. For H273R, residues comprising the active site spent more time in the catalytically competent conformation and were more positively correlated than the WT. We propose that by linking the equilibrium between the binding-occluded and binding-competent conformations of the nucleotide-binding pocket and other active-site dynamics to the correctness of the bound nucleotide, faithful nucleotide incorporation is achieved. These studies underscore the need to apply multiple biophysical and biochemical approaches to the elucidation of the physical basis for polymerase fidelity. 相似文献
83.
Winston Rojas Omer Campo María Antonieta Caro Juan Guillermo Lopera William Arias Constanza Duque Andrés Naranjo Jharley García Candelaria Vergara Jaime Lopera Erick Hernandez Ana Valencia Yuri Caicedo Mauricio Cuartas Javier Gutiérrez Sergio López Andrés Ruiz‐Linares Gabriel Bedoya 《American journal of physical anthropology》2010,143(1):13-20
Colombia is a country with great geographic heterogeneity and marked regional differences in pre‐Columbian native population density and in the extent of past African and European immigration. As a result, Colombia has one of the most diverse populations in Latin America. Here we evaluated ancestry in over 1,700 individuals from 24 Colombian populations using biparental (autosomal and X‐Chromosome), maternal (mtDNA), and paternal (Y‐chromosome) markers. Autosomal ancestry varies markedly both within and between regions, confirming the great genetic diversity of the Colombian population. The X‐chromosome, mtDNA, and Y‐chromosome data indicate that there is a pattern across regions indicative of admixture involving predominantly Native American women and European and African men. Am J Phys Anthropol 143:13–20, 2010. © 2010 Wiley‐Liss, Inc. 相似文献
84.
F. Grassi M. Labra S. Imazio R. Ocete Rubio O. Failla A. Scienza F. Sala 《Conservation Genetics》2006,7(6):837-845
The distribution of Vitis vinifera subsp. silvestris, the wild grapevine subspecies of Vitis vinifera L., has been dramatically reduced in its major sites of diffusion, at first by the spread, over the last 150 years, of pathogens from North America and, more recently, with fragmentation of habitat and disbranching by humans. In this work, 418 wild grapevine samples, belonging to 78 populations, were collected in their main Mediterranean distribution areas, including the Caucasus area, and the extent of their genetic variability evaluated by analysing plastid microsatellite DNA polymorphism. Results show low haplotype diversity value, with five haplotypes detected within the analysed populations. The highest within-population haplotypic diversity, with the presence of all five detected haplotypes, was found in the Caucasus regions and in the central regions of Italy. The distribution of all detected haplotypes suggests the Caucasian region as the possible center of origin of Vitis vinifera subsp. silvestris. A principal plastid lineage was found to be fixed in several locations, in the Northernmost European countries and in the Southern island of Sardinia. These results draw attention to two different refugium sites in the Mediterranean basin and suggest that conservation priority should be given to grapevine populations still preserved in hotspots of these regions. 相似文献
85.
Three human cases having mutations in the glycine N-methyltransferase (GNMT) gene have been reported. This enzyme transfers a methyl group from S-adenosylmethionine (SAM) to glycine to form S-adenosylhomocysteine (SAH) and N-methylglycine (sarcosine) and is believed to be involved in the regulation of methylation. All three cases have mild liver
disease but they seem otherwise unaffected. To study this further, gnmt deficient mice were generated for the first time. This resulted in the complete absence of GNMT protein and its activity
in livers of homozygous mice. Compared to WT animals the absence of GNMT resulted in up to a 7-fold increase of free methionine
and up to a 35-fold increase of SAM. The amount of SAH was significantly decreased (3 fold) in the homozygotes compared to
WT. The ratio of SAM/SAH increased from 3 in WT to 300 in livers of homozygous transgenic mice. This suggests a possible significant
change in methylation in the liver and other organs where GNMT is expressed. 相似文献
86.
Belen Guijarro Inmaculada Larena Paloma Melgarejo Antonieta De Cal 《Biocontrol Science and Technology》2006,16(3):257-269
The effects of drying methods (freeze-, spray-, and fluid bed-drying) on viability of Penicillium frequentans conidia were compared. Viability, estimated by germination of fluid bed- and freeze-dried conidia, was similar to that of fresh conidia. Skimmed milk alone, or in combination with other protectants, was added to conidia before freeze-drying. After the freeze-drying process, all protectants used, except glycerol improved conidial viability. Freeze-dried P. frequentans conidia did not maintain viability after 30 days of storage at room temperature, while conidia dried by fluid bed-drying showed 28% viability following 180 days after drying. This work also demonstrated a relationship between conidial viability after 1 year of storage at room temperature, moisture content after fluid bed-drying and initial weight of sample. Conidial moisture contents must be reduced to 5-15% for optimal storage at room temperature. P. frequentans conidia dried by fluid bed-drying were as effective as fresh conidia in controlling brown rot of peaches. 相似文献
87.
M. Del Rocío Ba?os-Lara Arpita Ghosh Antonieta Guerrero-Plata 《Journal of virology》2013,87(2):1242-1251
Human metapneumovirus (hMPV) is a respiratory paramyxovirus of global clinical relevance. Despite the substantial knowledge generated during the last 10 years about hMPV infection, information regarding the activation of the immune response against this virus remains largely unknown. In this study, we demonstrated that the helicase melanoma differentiation-associated gene 5 (MDA5) is essential to induce the interferon response after hMPV infection in human and mouse dendritic cells as well as in an experimental mouse model of infection. Our findings in vitro and in vivo showed that MDA5 is required for the expression and activation of interferon (IFN) regulatory factors (IRFs). hMPV infection induces activation of IRF-3, and it regulates the expression of IRF-7. However, both IRF-3 and IRF-7 are critical for the production of type I and type III IFNs. In addition, our in vivo studies in hMPV-infected mice indicated that MDA5 alters viral clearance, enhances disease severity and pulmonary inflammation, and regulates the production of cytokines and chemokines in response to hMPV. These findings are relevant for a better understanding of the pathogenesis of hMPV infection. 相似文献
88.
Silvia Federici Andrea Galimberti Fabrizio Bartolucci Ilaria Bruni Fabrizio De mattia Pierluigi Cortis Massimo Labra 《Botanical journal of the Linnean Society. Linnean Society of London》2013,171(4):687-699
We evaluated the utility of the core barcode regions (matK and rbcL) and the plastid intergenic spacer trnH‐psbA to distinguish between Thymus spp. This is a taxonomically complex group that has been investigated so far mainly using morphological approaches. Thirty‐six samples representing nine different morphospecies were collected and used for molecular analysis. The three markers showed clear amplification and sequencing. However, the genetic variation and the resulting haplotype networks showed that only Thymus capitatus forms a well‐defined ‘barcoding gap’ compared with the other taxa. The identification problems observed in the other Thymus spp. may be related to reduced gene flow among populations, resulting in high intraspecific and low interspecific genetic variation. This situation does not permit the definition of species‐specific barcodes. A second hypothesis suggests that morphological traits used for the delimitation of Thymus spp. do not reflect real biological and molecular species boundaries. If this is the case, the taxonomy of Thymus should be revised through extensive sampling and analyses with different tools (i.e. molecular variability, morphology, geographical distribution, etc.) to define the natural units at the species level. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013 , 171 , 687–699. 相似文献
89.
Arias-Rodriguez L Indy JR Ahumada-Hernández RI Barragán-Cupido H Avalos-Lázaro AA Páramo-Delgadillo S 《Revista de biología tropical》2011,59(2):683-692
The common snook Centropomus undecimalis inhabits marine, brackish and freshwater habitats in the Western Central Atlantic Ocean, including the Gulf of Mexico. Common snook is an economically important fish in many localities, nevertheless the number of studies on its biology and genetics are still few. The present study attempts to establish the cytogenetic profiles of the specimens collected in Paraiso Municipality Tabasco, Mexico. Tissue of five females and eight male organisms were processed by conventional cytological techniques to obtain chromosome slides of high quality in order to assemble the karyotype. The results from the kidney tissue analysis showed that 85.1% of 288 mitosis had a 2n = 48 chromosomes, and 52.8% of 104 meiosis exhibited the haploid number 1n = 24. The diploid karyotype showed 48 monoarmed chromosomes of the telocentric (T) type. There was no chromosome heteromorphism between females and males. The diploid karyotype was very similar to that observed in the majority of marine fishes. 相似文献
90.
Michael J. Griffiths Jennifer V. Lemon Ajit Rayamajhi Prakash Poudel Pramina Shrestha Vijay Srivastav Rachel Kneen Antonieta Medina-Lara Rupa R. Singh Tom Solomon 《PLoS neglected tropical diseases》2013,7(9)