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1.
Seed Development in Phaseolus vulgaris L. cv Seminole: I. Developmental Independence of Seed Maturation 下载免费PDF全文
Phaseolus vulgaris L. cv Seminole pods removed from the plant continued their development when incubated in suitable conditions. Seeds continued to grow and develop and pods and seeds passed through an apparently normal developmental sequence to dryness. Seed growth was at the expense of pod dry weight (DW) reserves. Losses of pod DW paralleled DW gains by seeds in detached pods and in pod cylinders containing a seed. The transfer activity was apparent only within the period 10 to 30 days after anthesis (DAA) with maximal activity between 15 to 20 DAA. This period corresponds to maximum pod growth and the attainment of maximal DW. Seeds are in only the early phase of seed growth at this time. No DW transfer was observed at developmental stages beyond 30 to 35 DAA when normal senescence DW losses in pods became evident and seeds were in the later phase of seed fill. Pods or pod cylinders remained green and succulent over the transfer period, later passing through yellowing and drying phases characteristic of normal development. DW transfer was dependent on funicle integrity and was readily detectable in pod cylinders after 7 days incubation. The DW transfer activity may contribute to continuing nutrition of seeds under conditions where the normal assimilate supply to seeds becomes limiting. Defoliation and water stress treatments applied to Phaseolus plants reduced seed yields but allowed persistence of seed maturation processes such that all seeds developing to dryness were capable of germination. 相似文献
2.
Michael W. Fountain Robert Chiovetti Henri Kercret David O. Parrish Jere P. Segrest 《生物化学与生物物理学报:生物膜》1980,596(3):420-425
A method has been developed for the rapid separation of cells in suspension from non-cell associated lipid vesicles in various assays for vesicle-cell interaction. Separation is achieved on a discontinuous Ficoll-Paque gradient. Cells and free vesicles are totally separated, as evidenced by both radiolabelled vesicles, and vesicles containing the fluorescent dye 6-carboxyfluorescein. The main advantages of this method are the rapidity, efficacy, and gentleness of the separation. Viability of the cells remains consistently high (greater than 96%) throughout the separation. Since this method involves a one-step centrifugation, it precludes the necessity for repeated washings of cells which have been incubated with lipid vesicles. 相似文献
3.
Phosphatidylcholine (PC) liposomes inhibited the proliferative response of bovine lymphocytes to the mitogen phytohemagglutinin (PHA). PC liposomes containing a soluble antigen extract ofBrucella abortus (BASA) reversed the suppression caused by PC liposomes. PC liposomes containing lipopolysaccharide (LPS) fromEscherichia coli, Salmonella abortus equi, orSerratia marcescens also reversed the suppression of PC liposomes. No detectable BASA protein was associated into PC liposomes. Detectable LPS from BASA,E. coli, S. abortus equi, andS. marcescens was associated into the PC liposomes. The reversal by BASA of PC liposome suppression appears to be due to the LPS present in BASA, since LPS of several other bacteria was also able to reverse suppression. The possible mechanism of reversal of suppression by LPS is discussed. 相似文献
4.
Fountain KJ Kloss A Garibyan I Blitshteyn B Brezzani A Kyostio-Moore S Zuk A Sacchiero R Cohen AS 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2007,846(1-2):245-251
An ion exchange high performance liquid chromatography method was developed for determining creatinine levels in both mouse and rat serum samples. Separation of creatinine from other serum components was achieved in 10 min using a 100 x 4.1-mm, 10 microm strong cation exchange column following acetonitrile precipitation of serum proteins. Incorporation of a guard cartridge placed in-line prior to the analytical column was employed to prevent interference from compounds used in renal disease animal trials. Creatinine levels in normal and diseased animals were accurately determined in the 0.01-10 mg/dL range, and average recovery of the method was approximately 85% for both mouse and rat serum. Addition of 0.5-1.0% acetic acid to the acetonitrile used for protein precipitation significantly improved creatinine recovery to above 97% in mouse serum. The method was used for routine preclinical diagnosis of rat and mouse model renal function, and for the evaluation of renal disease treatment efficacy. 相似文献
5.
6.
Physical mapping of the von Recklinghausen neurofibromatosis region on chromosome 17 总被引:6,自引:9,他引:6 下载免费PDF全文
Jane W. Fountain Margaret R. Wallace Anne M. Brereton Peter O''''Connell Raymond L. White Donna C. Rich David H. Ledbetter Robin J. Leach R. E. Keith Fournier Anil G. Menon James F. Gusella David Barker Karen Stephens Francis S. Collins 《American journal of human genetics》1989,44(1):58-67
The von Recklinghausen neurofibromatosis (NF1) locus has been linked to chromosome 17, and recent linkage analyses place the gene on the proximal long arm. NF1 probably resides in 17q11.2, since two unrelated NF1 patients have been identified who possess constitutional reciprocal translocations involving 17q11.2 with chromosomes 1 and 22. We have used a somatic-cell hybrid from the t(17;22) individual, along with other hybrid cell lines, to order probes around the NF1 locus. An additional probe, 17L1, has been isolated from a NotI linking library made from flow-sorted chromosome 17 material and has been mapped to a region immediately proximal to the translocation breakpoint. While neither NF1 translocation breakpoint has yet been identified by pulse-field gel analysis, an overlap between two probes, EW206 and EW207, has been detected. Furthermore, we have identified the breakpoint in a non-NF1 translocation, SP-3, on the proximal side of the NF1 locus. This breakpoint has been helpful in creating a 1,000-kb pulsed-field map, which includes the closely linked NF1 probes HHH202 and TH17.19. The combined somatic-cell hybrid and pulsed-field gel analysis we report here favors the probe order D17Z1-HHH202-TH17.19-CRYB1-17L1-NF1- (EW206, EW207, EW203, L581, L946)-(ERBB2, ERBA1). The agreement in probe ordering between linkage analysis and physical mapping is excellent, and the availability of translocation breakpoints in NF1 should now greatly assist the cloning of this locus. 相似文献
7.
Megan M Rolf Dorian J Garrick Tara Fountain Holly R Ramey Robert L Weaber Jared E Decker E John Pollak Robert D Schnabel Jeremy F Taylor 《遗传、选种与进化》2015,47(1)
Background
While several studies have examined the accuracy of direct genomic breeding values (DGV) within and across purebred cattle populations, the accuracy of DGV in crossbred or multi-breed cattle populations has been less well examined. Interest in the use of genomic tools for both selection and management has increased within the hybrid seedstock and commercial cattle sectors and research is needed to determine their efficacy. We predicted DGV for six traits using training populations of various sizes and alternative Bayesian models for a population of 3240 crossbred animals. Our objective was to compare alternate models with different assumptions regarding the distributions of single nucleotide polymorphism (SNP) effects to determine the optimal model for enhancing feasibility of multi-breed DGV prediction for the commercial beef industry.Results
Realized accuracies ranged from 0.40 to 0.78. Randomly assigning 60 to 70% of animals to training (n ≈ 2000 records) yielded DGV accuracies with the smallest coefficients of variation. Mixture models (BayesB95, BayesCπ) and models that allow SNP effects to be sampled from distributions with unequal variances (BayesA, BayesB95) were advantageous for traits that appear or are known to be influenced by large-effect genes. For other traits, models differed little in prediction accuracy (~0.3 to 0.6%), suggesting that they are mainly controlled by small-effect loci.Conclusions
The proportion (60 to 70%) of data allocated to training that optimized DGV accuracy and minimized the coefficient of variation of accuracy was similar to large dairy populations. Larger effects were estimated for some SNPs using BayesA and BayesB95 models because they allow unequal SNP variances. This substantially increased DGV accuracy for Warner-Bratzler Shear Force, for which large-effect quantitative trait loci (QTL) are known, while no loss in accuracy was observed for traits that appear to follow the infinitesimal model. Large decreases in accuracy (up to 0.07) occurred when SNPs that presumably tag large-effect QTL were over-regressed towards the mean in BayesC0 analyses. The DGV accuracies achieved here indicate that genomic selection has predictive utility in the commercial beef industry and that using models that reflect the genomic architecture of the trait can have predictive advantages in multi-breed populations.Electronic supplementary material
The online version of this article (doi:10.1186/s12711-015-0106-8) contains supplementary material, which is available to authorized users. 相似文献8.
Zhang H Rider SD Henderson JT Fountain M Chuang K Kandachar V Simons A Edenberg HJ Romero-Severson J Muir WM Ogas J 《The Journal of biological chemistry》2008,283(33):22637-22648
CHD3 proteins are ATP-dependent chromatin remodelers that contribute to repression of developmentally regulated genes in both animal and plant systems. In animals, this repression has been linked to a multiple subunit complex, Mi-2/NuRD, whose constituents include a CHD3 protein, a histone deacetylase, and a methyl-CpG-binding domain protein. In Arabidopsis, PICKLE (PKL) codes for a CHD3 protein that acts during germination to repress expression of seed-associated genes. Repression of seed-associated traits is promoted in pkl seedlings by the plant growth regulator gibberellin (GA). We undertook a microarray analysis to determine how PKL and GA act to promote the transition from seed to seedling. We found that PKL and GA act in separate pathways to repress expression of seed-specific genes. Comparison of genomic datasets revealed that PKL-dependent genes are enriched for trimethylation of histone H3 lysine 27 (H3K27me3), a repressive epigenetic mark. Chromatin immunoprecipitation studies demonstrate that PKL promotes H3K27me3 in both germinating seedlings and in adult plants but do not identify a connection between PKL-dependent expression and acetylation levels. Taken together, our analyses illuminate a new pathway by which CHD3 remodelers contribute to repression in eukaryotes. 相似文献
9.
The purpose of this study was to examine the effects of catecholamines on in vitro growth of a range of bacterial species, including anaerobes. Bacteria tested included: Porphyromonas gingivalis, Bacteriodes fragilis, Shigella boydii, Shigella sonnie, Enterobacter Sp, and Salmonella choleraesuis. The results of the current study indicated that supplementation of bacterial cultures in minimal medium with norepinephrine or epinephrine did not result in increased growth of bacteria. Positive controls involving treatment of Escherichia coli with catecholamines did result in increased growth of that bacterial species. The results of the present study extend previous observations that showed differential capability of catecholamines to enhance bacterial growth in vitro. 相似文献
10.
Fliih, a gelsolin-related cytoskeletal regulator essential for early mammalian embryonic development 下载免费PDF全文
Campbell HD Fountain S McLennan IS Berven LA Crouch MF Davy DA Hooper JA Waterford K Chen KS Lupski JR Ledermann B Young IG Matthaei KI 《Molecular and cellular biology》2002,22(10):3518-3526
The Drosophila melanogaster flightless I gene is required for normal cellularization of the syncytial blastoderm. Highly conserved homologues of flightless I are present in Caenorhabditis elegans, mouse, and human. We have disrupted the mouse homologue Fliih by homologous recombination in embryonic stem cells. Heterozygous Fliih mutant mice develop normally, although the level of Fliih protein is reduced. Cultured homozygous Fliih mutant blastocysts hatch, attach, and form an outgrowing trophoblast cell layer, but egg cylinder formation fails and the embryos degenerate. Similarly, Fliih mutant embryos initiate implantation in vivo but then rapidly degenerate. We have constructed a transgenic mouse carrying the complete human FLII gene and shown that the FLII transgene is capable of rescuing the embryonic lethality of the homozygous targeted Fliih mutation. These results confirm the specific inactivation of the Fliih gene and establish that the human FLII gene and its gene product are functional in the mouse. The Fliih mouse mutant phenotype is much more severe than in the case of the related gelsolin family members gelsolin, villin, and CapG, where the homozygous mutant mice are viable and fertile but display alterations in cytoskeletal actin regulation. 相似文献