全文获取类型
收费全文 | 87篇 |
免费 | 6篇 |
出版年
2023年 | 2篇 |
2021年 | 1篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 2篇 |
2017年 | 2篇 |
2015年 | 3篇 |
2014年 | 4篇 |
2013年 | 6篇 |
2012年 | 4篇 |
2011年 | 4篇 |
2010年 | 3篇 |
2009年 | 3篇 |
2008年 | 12篇 |
2007年 | 5篇 |
2006年 | 2篇 |
2005年 | 7篇 |
2004年 | 7篇 |
2003年 | 1篇 |
2002年 | 5篇 |
1999年 | 1篇 |
1997年 | 2篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 4篇 |
1990年 | 2篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1981年 | 1篇 |
1937年 | 1篇 |
排序方式: 共有93条查询结果,搜索用时 546 毫秒
81.
Tringali MD Seyoum S Carney SL Davis MC Rodriguez-Lopez MA Reynolds Iii JE Haubold E 《Molecular ecology resources》2008,8(2):328-331
Here we describe 18 polymorphic microsatellite loci for Trichechus manatus latirostris (Florida manatee), isolated using a polymerase chain reaction‐based technique. The number of alleles at each locus ranged from two to four (mean = 2.5) in specimens from southwest (n = 58) and northeast (n = 58) Florida. Expected and observed heterozygosities ranged from 0.11 to 0.67 (mean = 0.35) and from 0.02 to 0.78 (mean = 0.34), respectively. Departures from Hardy–Weinberg equilibrium occurred at two loci. There was no evidence of genotypic disequilibrium for any pair of loci. For individual identification, mean random‐mating and θ‐corrected match probabilities were 9.36 × 10?7 and 1.95 × 10?6, respectively. 相似文献
82.
Lee YC Block G Chen H Folch-Puy E Foronjy R Jalili R Jendresen CB Kimura M Kraft E Lindemose S Lu J McLain T Nutt L Ramon-Garcia S Smith J Spivak A Wang ML Zanic M Lin SH 《Protein expression and purification》2008,62(2):223-229
We have developed a simple method for isolating and purifying plasma membrane proteins from various cell types. This one-step affinity-chromatography method uses the property of the lectin concanavalin A (ConA) and the technique of magnetic bead separation to obtain highly purified plasma membrane proteins from crude membrane preparations or cell lines. ConA is immobilized onto magnetic beads by binding biotinylated ConA to streptavidin magnetic beads. When these ConA magnetic beads were used to enrich plasma membranes from a crude membrane preparation, this procedure resulted in 3.7-fold enrichment of plasma membrane marker 5′-nucleotidase activity with 70% recovery of the activity in the crude membrane fraction of rat liver. In agreement with the results of 5′-nucleotidase activity, immunoblotting with antibodies specific for a rat liver plasma membrane protein, CEACAM1, indicated that CEACAM1 was enriched about threefold relative to that of the original membranes. In similar experiments, this method produced 13-fold enrichment of 5′-nucleotidase activity with 45% recovery of the activity from a total cell lysate of PC-3 cells and 7.1-fold enrichment of 5′-nucleotidase activity with 33% recovery of the activity from a total cell lysate of HeLa cells. These results suggest that this one-step purification method can be used to isolate total plasma membrane proteins from tissue or cells for the identification of membrane biomarkers. 相似文献
83.
PP2A regulates the pro-apoptotic activity of FOXO1 总被引:1,自引:0,他引:1
84.
As part of a comprehensive bay scallop restoration plan in Florida, we implemented a genetic monitoring program to evaluate the impact of shellfish restoration. Restoration involved the deployment of hatchery-produced scallops in cages (the restoration stock), which created spawner aggregations in locations that exhibited low densities of wild scallops. The success of the restorations was evaluated by comparing the genetic composition of wild scallops before (pre-restoration samples) and after (assessment samples) each deployment. The effectiveness of this approach in determining the contribution of the restoration stock relied on a two-part mitochondrial DNA (mtDNA) assay developed to differentiate between scallops produced by the restoration stock and those produced by the remnant wild population. Assessment scallops were sequenced initially for a 417 base-pair fragment (segment 2), and if the mtDNA sequence was found to be identical to that of any restoration-stock scallop, the assessment scallop was sequenced for an additional 462 base pairs (segment 1). We screened assessment samples from six locations in west-central Florida for evidence of a significant contribution from the restoration stock to the wild population, manifested as a significant increase in the frequency of the haplotypes diagnostic of the restoration stock. In the 3 years of monitoring, 23 of 512, 13 of 600, and 19 of 991 assessment- sample scallops collected from the vicinities of the three restoration locations had haplotypes identical to those of restoration-stock individuals. In all years, the assessment-sample frequencies of haplotypes characteristic of the restoration stock were not significantly different from prerestoration-sample frequencies. This absence of a detectable contribution based on genetic data contrasts with abundance data from one location, which suggests a dramatic increase in the abundance of scallops following the restoration effort. 相似文献
85.
A whole-cell biotransformation system for the conversion of d-fructose to d-mannitol was developed in Escherichia coli by constructing a recombinant oxidation/reduction cycle. First, the mdh gene, encoding mannitol dehydrogenase of Leuconostoc pseudomesenteroides ATCC 12291 (MDH), was expressed, effecting strong catalytic activity of an NADH-dependent reduction of d-fructose to d-mannitol in cell extracts of the recombinant E. coli strain. By contrast whole cells of the strain were unable to produce d-mannitol from d-fructose. To provide a source of reduction equivalents needed for d-fructose reduction, the fdh gene from Mycobacterium vaccae N10 (FDH), encoding formate dehydrogenase, was functionally co-expressed. FDH generates the NADH used for d-fructose reduction by dehydrogenation of formate to carbon dioxide. These recombinant E. coli cells were able to form d-mannitol from d-fructose in a low but significant quantity (15 mM). The introduction of a further gene, encoding the glucose facilitator protein of Zymomonas mobilis (GLF), allowed the cells to efficiently take up d-fructose, without simultaneous phosphorylation. Resting cells of this E. coli strain (3 g cell dry weight/l) produced 216 mM d-mannitol in 17 h. Due to equimolar formation of sodium hydroxide during NAD+-dependent oxidation of sodium formate to carbon dioxide, the pH value of the buffered biotransformation system increased by one pH unit within 2 h. Biotransformations conducted under pH control by formic-acid addition yielded d-mannitol at a concentration of 362 mM within 8 h. The yield Y
D-mannitol/D-fructosewas 84 mol%. These results show that the recombinant strain of E. coli can be utilized as an efficient biocatalyst for d-mannitol formation. 相似文献
86.
Silva TD da Cunha Aguiar LC Leta J Santos DO Cardoso FS Cabral LM Rodrigues CR Castro HC 《Cell biology education》2004,3(4):235-240
In this study, we analyze the contribution of the undergraduate student who participates in the process of generating scientific data and developing a research project using Brazilian research as an example. Historically, undergraduate students have performed the critical role of research assistants in developing countries. This aspect has been underappreciated as a means of generating scientific data in Brazilian research facilities. Brazilian educational institutions are facing major age-related generational changes among the science faculty within the next 5-10 yr. A lack of adequate support for graduate students leads to a concern that undergraduates will not be interested in choosing research assistant programs and, subsequently, academic research careers. To remedy this situation it is important to focus on ways to encourage new research careers and enhance university-industry collaborations. 相似文献
87.
Molecular Ecology Resources Primer Development Consortium Andris M Arias MC Barthel BL Bluhm BH Bried J Canal D Chen XM Cheng P Chiappero MB Coelho MM Collins AB Dash M Davis MC Duarte M Dubois MP Françoso E Galmes MA Gopal K Jarne P Kalbe M Karczmarski L Kim H Martella MB McBride RS Negri V Negro JJ Newell AD Piedade AF Puchulutegui C Raggi L Samonte IE Sarasola JH See DR Seyoum S Silva MC Solaro C Tolley KA Tringali MD Vasemägi A Xu LS Zanón-Martínez JI 《Molecular ecology resources》2012,12(4):779-781
This article documents the addition of 171 microsatellite marker loci and 27 pairs of single nucleotide polymorphism (SNP) sequencing primers to the Molecular Ecology Resources Database. Loci were developed for the following species: Bombus pauloensis, Cephalorhynchus heavisidii, Cercospora sojina, Harpyhaliaetus coronatus, Hordeum vulgare, Lachnolaimus maximus, Oceanodroma monteiroi, Puccinia striiformis f. sp. tritici, Rhea americana, Salmo salar, Salmo trutta, Schistocephalus solidus, Sousa plumbea and Tursiops aduncus. These loci were cross-tested on the following species: Aquila heliaca, Bulweria bulwerii, Buteo buteo, Buteo swainsoni, Falco rusticolus, Haliaeetus albicilla, Halobaena caerulea, Hieraaetus fasciatus, Oceanodroma castro, Puccinia graminis f. sp. Tritici, Puccinia triticina, Rhea pennata and Schistocephalus pungitii. This article also documents the addition of 27 sequencing primer pairs for Puffinus baroli and Bulweria bulwerii and cross-testing of these loci in Oceanodroma castro, Pelagodroma marina, Pelecanoides georgicus, Pelecanoides urinatrix, Thalassarche chrysostoma and Thalassarche melanophrys. 相似文献
88.
89.
Steffen LS Guyon JR Vogel ED Howell MH Zhou Y Weber GJ Zon LI Kunkel LM 《Developmental biology》2007,309(2):180-192
90.
Effects of dietary fracture toughness and dental wear on chewing efficiency in geladas (Theropithecus gelada) 下载免费PDF全文
Julia Fritz Marcus Clauss Chalachew Seyoum Nga Nguyen Peter J. Fashing 《American journal of physical anthropology》2014,155(1):17-32
Chewing efficiency has been associated with fitness in mammals, yet little is known about the behavioral, ecological, and morphological factors that influence chewing efficiency in wild animals. Although research has established that dental wear and food material properties independently affect chewing efficiency, few studies have addressed the interaction among these factors. We examined chewing efficiency, measured as mean fecal particle size, as a function of seasonal shifts in diet (and corresponding changes in food fracture toughness) in a single breeding population of a grazing primate, the gelada monkey, at Guassa, Ethiopia. We also measured dental topographic traits (slope, angularity, and relief index) and relative two‐ and three‐dimensional shearing crest lengths in a cross‐sectional wear series of gelada molars. Chewing efficiency decreased during the dry season, a pattern corresponding to the consumption of foods with higher fracture toughness. Older individuals experienced the most pronounced decreases in chewing efficiency between seasons, implicating dental wear as a causal factor. This pattern is consistent with our finding that dental topographic metrics and three‐dimensional relative shearing crest lengths were lowest at the last stage of wear. Integrating these lines of behavioral, ecological, and morphological evidence provides some of the first empirical support for the hypothesis that food fracture toughness and dental wear together contribute to chewing efficiency. Geladas have the highest chewing efficiencies measured thus far in primates, and may be analogous to equids in their emphasis on dental design as a means of particle size reduction in the absence of highly specialized digestive physiology. Am J Phys Anthropol 155:17–32, 2014. © 2014 Wiley Periodicals, Inc. 相似文献