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181.
Miguel Del Corral JM Castro MA Lucena Rodri Guez M Chamorro P Cuevas C San Feliciano A 《Bioorganic & medicinal chemistry》2007,15(17):5760-5774
Diterpenylquinone/hydroquinone derivatives were prepared through Diels-Alder cycloaddition between natural myrcecommunic acid or its methyl ester and p-benzoquinone (p-BQ), using BF(3).Et(2)O as catalyst or under microwave (Mw) irradiation. Acetyl, methyl and benzyl derivatives of several diterpenylnaphthohydroquinone were prepared from cycloadducts following two basic synthetic strategies, either protection before aromatisation or viceversa. Some of them were further functionalised at the B-ring of the decaline core. Most of the new compounds were evaluated and some of them resulted cytotoxic against several tumour cell lines with IC(50) values under the microM level. 相似文献
182.
Salcedo M Cuevas C Alonso JL Otero G Faircloth G Fernandez-Sousa JM Avila J Wandosell F 《Apoptosis : an international journal on programmed cell death》2007,12(2):395-409
The isolation of new molecules from marine sources opens the door to their possible therapeutic use against tumors and other
pathological conditions. Indeed, we recently defined the cytotoxicity of ES 285, obtained from the clam Mactromeris polynima, and its affects on the cells microfilament but not the microtubule network. Considering the analogy between ES 285 and sphingosine-related
lipids, we wondered whether ES 285 might affect the activity of PKC at the intracellular level. While we anticipated that
ES 285 might inhibit PKC, it turns out that in contrast it serves to activate PKC at the cellular level. Indeed, like other
sphingosine-related lipids, ES 285 induces the phosphorylation of MARCKS. Additionally, we further examined the cytotoxicity
of ES 285 to elucidate the molecular mechanisms through which this compound triggers apoptosis. When the influence of ES 285
on “cell death markers” was assessed, it became clear that ES285 activates caspase 3 and 12, and that it modified the phosphorylation
of p53. In contrast, ES 285 does not affect other pathways widely implicated in regulating cell survival/apoptosis, such as
JNK, Erks or Akt. Thus, these data suggest that ES 285-triggers an atypical cell death program when compared to other sphingosine-dependent
apoptosis pathways. 相似文献
183.
Germ cells in many vertebrate and invertebrate species initiate gametogenesis by forming groups of interconnected cells known as germline cysts. Recent studies using Xenopus, mouse and Drosophila are beginning to uncover the cellular and molecular mechanisms that control germline cyst formation and, in conjunction with morphological evidence, suggest that the process is highly conserved during evolution. This article discusses these recent findings and argues that cysts play an important and general role in germ line development. 相似文献
184.
Savannah E. Sanchez Daniel A. Cuevas Jason E. Rostron Tiffany Y. Liang Cullen G. Pivaroff Matthew R. Haynes Jim Nulton Ben Felts Barbara A. Bailey Peter Salamon Robert A. Edwards Alex B. Burgin Anca M. Segall Forest Rohwer 《Journal of visualized experiments : JoVE》2015,(100)
Current investigations into phage-host interactions are dependent on extrapolating knowledge from (meta)genomes. Interestingly, 60 - 95% of all phage sequences share no homology to current annotated proteins. As a result, a large proportion of phage genes are annotated as hypothetical. This reality heavily affects the annotation of both structural and auxiliary metabolic genes. Here we present phenomic methods designed to capture the physiological response(s) of a selected host during expression of one of these unknown phage genes. Multi-phenotype Assay Plates (MAPs) are used to monitor the diversity of host substrate utilization and subsequent biomass formation, while metabolomics provides bi-product analysis by monitoring metabolite abundance and diversity. Both tools are used simultaneously to provide a phenotypic profile associated with expression of a single putative phage open reading frame (ORF). Representative results for both methods are compared, highlighting the phenotypic profile differences of a host carrying either putative structural or metabolic phage genes. In addition, the visualization techniques and high throughput computational pipelines that facilitated experimental analysis are presented. 相似文献
185.
186.
José M Bueno Juan C Cuevas José M Fiandor Silvestre García-Ochoa Federico Gómez de las Heras 《Bioorganic & medicinal chemistry letters》2002,12(2):121-124
A number of novel 3',4'-fused dioxolane and dioxane sordarin derivatives were synthesised for structure-activity relationship studies. Many of these derivatives exhibit high activity against Candida spp. and Cryptococcus neoformans. 相似文献
187.
Background
Cancer and other disorders are due to genomic lesions. SNP-microarrays are able to measure simultaneously both genotype and copy number (CN) at several Single Nucleotide Polymorphisms (SNPs) along the genome. CN is defined as the number of DNA copies, and the normal is two, since we have two copies of each chromosome. The genotype of a SNP is the status given by the nucleotides (alleles) which are present on the two copies of DNA. It is defined homozygous or heterozygous if the two alleles are the same or if they differ, respectively. Loss of heterozygosity (LOH) is the loss of the heterozygous status due to genomic events. 相似文献188.
Background
Paracoccidioides brasiliensis (Eukaryota, Fungi, Ascomycota) is a thermodimorphic fungus, the etiological agent of paracoccidioidomycosis, the most important systemic mycoses in Latin America. Three isolates corresponding to distinct phylogenetic lineages of the Paracoccidioides species complex had their genomes sequenced. In this study the identification and characterization of class II transposable elements in the genomes of these fungi was carried out.Results
A genomic survey for DNA transposons in the sequence assemblies of Paracoccidioides, a genus recently proposed to encompass species P. brasiliensis (harboring phylogenetic lineages S1, PS2, PS3) and P. lutzii (Pb01-like isolates), has been completed. Eight new Tc1/mariner families, referred to as Trem (Tr ansposable e lement m ariner), labeled A through H were identified. Elements from each family have 65-80% sequence similarity with other Tc1/mariner elements. They are flanked by 2-bp TA target site duplications and different termini. Encoded DDD-transposases, some of which have complete ORFs, indicated that they could be functionally active. The distribution of Trem elements varied between the genomic sequences characterized as belonging to P. brasiliensis (S1 and PS2) and P. lutzii. TremC and H elements would have been present in a hypothetical ancestor common to P. brasiliensis and P. lutzii, while TremA, B and F elements were either acquired by P. brasiliensis or lost by P. lutzii after speciation. Although TremD and TremE share about 70% similarity, they are specific to P. brasiliensis and P. lutzii, respectively. This suggests that these elements could either have been present in a hypothetical common ancestor and have evolved divergently after the split between P. brasiliensis and P. Lutzii, or have been independently acquired by horizontal transfer.Conclusions
New families of Tc1/mariner DNA transposons in the genomic assemblies of the Paracoccidioides species complex are described. Families were distinguished based on significant BLAST identities between transposases and/or TIRs. The expansion of Trem in a putative ancestor common to the species P. brasiliensis and P. lutzii would have given origin to TremC and TremH, while other elements could have been acquired or lost after speciation had occurred. The results may contribute to our understanding of the organization and architecture of genomes in the genus Paracoccidioides. 相似文献189.
Bott R Saldajeno M Cuevas W Ward D Scheffers M Aehle W Karkehabadi S Sandgren M Hansson H 《Biochemistry》2008,47(21):5746-5754
The three-dimensional structure of a complete Hypocrea jecorina glucoamylase has been determined at 1.8 A resolution. The presented structure model includes the catalytic and starch binding domains and traces the course of the 37-residue linker segment. While the structures of other fungal and yeast glucoamylase catalytic and starch binding domains have been determined separately, this is the first intact structure that allows visualization of the juxtaposition of the starch binding domain relative to the catalytic domain. The detailed interactions we see between the catalytic and starch binding domains are confirmed in a second independent structure determination of the enzyme in a second crystal form. This second structure model exhibits an identical conformation compared to the first structure model, which suggests that the H. jecorina glucoamylase structure we report is independent of crystal lattice contact restraints and represents the three-dimensional structure found in solution. The proposed starch binding regions for the starch binding domain are aligned with the catalytic domain in the three-dimensional structure in a manner that supports the hypothesis that the starch binding domain serves to target the glucoamylase at sites where the starch granular matrix is disrupted and where the enzyme might most effectively function. 相似文献
190.
Sebastián Sánchez Vicente Bravo Juan Francisco García Nicolás Cruz Manuel Cuevas 《World journal of microbiology & biotechnology》2008,24(5):709-716
The fermentation of d-glucose and d-xylose mixtures by the yeast Candida tropicalis NBRC 0618 has been studied under the most favourable operation conditions for the culture, determining the most adequate
initial proportion in these sugars for xylitol production. In all the experiments a synthetic culture medium was used, with
an initial total substrate concentration of 25 g L−1, a constant pH of 5.0 and a temperature of 30 °C. From the experimental results, it was deduced that the highest values of
specific rates of production and of overall yield in xylitol were achieved for the mixtures with the highest percentage of
d-xylose, specifically in the culture with the initial d-glucose and d-xylose concentrations of 1 and 24 g L−1, respectively, with an overall xylitol yield of 0.28 g g−1. In addition, the specific rates of xylitol production declined over the time course of the culture and the formation of
this bioproduct was favoured by the presence of small quantities of d-glucose. The sum of the overall yield values in xylitol and ethanol for all the experiments ranged from 0.26 to 0.56 g bioproduct/g
total substrate. 相似文献