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291.
Juliana Bello Baron Maurer Antony Bacic Adaucto Bellarmino Pereira-Netto Lucélia Donatti Selma Faria Zawadzki-Baggio Filomena Angela Pettolino 《Phytochemistry》2010,71(11-12):1400-1409
Arabinogalactan-proteins (AGPs), found in the culture medium of suspension cells of Araucaria angustifolia grown in plant growth regulator-free and plant growth regulator-containing BM media, BM0 and BM2, respectively, were evaluated quantitatively and qualitatively. The concentrated extracellular fractions (CEFs), obtained from suspension cell cultures grown for 20 days in BM0 and BM2 media yielded two fractions, CEF-0 and CEF-2, respectively. CEF-0 and CEF-2 was submitted to selective precipitation using the β-glucosyl Yariv reagent (β-GlcY) to isolate AGPs for structural characterization; this yielded fractions designated CEF-0YPF and CEF-2YPF, respectively. The monosaccharide composition analysis established that samples were composed of Rha, Ara, Gal and uronic acid in a molar ratio 3:37:55:5 (CEF-0YPF) and 1:37:58:4 (CEF-2YPF), although trace amounts (<0.5 mol%) of Xyl were also found. Methylation analysis of CEF-YPF fractions showed similar results for both CEF-0YPF and CEF-2YPF, with non-reducing terminal units of Araf, Arap, Galp, Rhap and Xylp, as well as 3-O-substituted and 5-O-substituted Araf units and 3-O-substituted, 6-O-substituted and 3,6-di-O-susbtituted Galp units. The amino acid composition analysis established Ser, Ala, and Hyp as major amino acids in both samples. In conclusion, this investigation has shown that CEF-0YPF and CEF-2YPF contain macromolecules having typical AGP characteristics, including a Hyp/Ala/Ser-rich protein moiety, a (1 → 3) and/or (1 → 6) linked β-d-galactopyranosyl main chain substituted by Gal, Ara, Rha and Xyl residues, and binding affinity for β-GlcY and monoclonal anti-AGP antibodies. 相似文献
292.
Vilardo Mde C Thomé JD Esteves WT Filgueiras AL de Oliveira SS 《Memórias do Instituto Oswaldo Cruz》2006,101(5):499-501
A multiplex polymerase chain reaction (PCR) assay was performed on 167 thermophilic campylobacters isolated from non-human primates. Samples were first identified by phenotypic methods resulting in 64 Campylobacter jejuni and 103 C. coli strains. Four strains identified biochemically as C. coli, were then determined to be C. jejuni by PCR. Comparison of methodologies showed that the main discrepancies were attributed to the hippurate hydrolysis test and sensitivity to cephalothin and nalidixic acid. Analysis of data showed that the application of phenotypic methods should be supplemented by a molecular method to offer a more reliable Campylobacter identification. 相似文献
293.
294.
Diego F. Muniz-Da-Silva Juliana Passos Dustin S. Siegel Selma M. Almeida-Santos 《Acta zoologica》2020,101(1):69-77
Sperm storage is common in the oviducts of female snakes and results in the decoupling of mating from ovulation and fertilization. In the majority of female snakes examined, sperm storage occurs in receptacles of the infundibular regions of the oviducts. In pitvipers (Viperida, Crotalinae), the storage of sperm was described in the caudal regions of the oviducts (utero-vaginal junction) through a mechanism termed uterine muscular twisting (UMT). Uterine muscular twisting was described as a twisting of the oviducts after copulation because of uterine contractions. The twisting remains until ovulation at which time the oviducts straighten and sperm migrate cranially to fertilize ovulated ova. Here, we demonstrate that the UMT is not formed by twisting (rotation around axis) of the oviducts of Crotalus durissus but rather coils formed by the inner layers of the oviducts at the utero-vaginal junction. Contrary to previous findings, coiling of the oviducts is present in females throughout the year, not only in the postcopulatory period; however, the degree of coiling is variable and may be linked to the seasonal reproductive cycle of C. durissus. We categorize the degree of coiling as pronounced coil, discreet coil or absent coil. 相似文献
295.
Structured RNAs traverse complex energy landscapes that include valleys representing misfolded intermediates. In Neurospora crassa and Saccharomyces cerevisiae, efficient splicing of mitochondrial group I and II introns requires the DEAD box proteins CYT-19 and Mss116p, respectively, which promote folding transitions and function as general RNA chaperones. To test the generality of RNA misfolding and the activities of DEAD box proteins in vitro, here we measure native folding of a small group I intron ribozyme from the bacterium Azoarcus by monitoring its catalytic activity. To develop this assay, we first measure cleavage of an oligonucleotide substrate by the prefolded ribozyme. Substrate cleavage is rate-limited by binding and is readily reversible, with an internal equilibrium near unity, such that the amount of product observed is less than the amount of native ribozyme. We use this assay to show that approximately half of the ribozyme folds readily to the native state, whereas the other half forms an intermediate that transitions slowly to the native state. This folding transition is accelerated by urea and increased temperature and slowed by increased Mg(2+) concentration, suggesting that the intermediate is misfolded and must undergo transient unfolding during refolding to the native state. CYT-19 and Mss116p accelerate refolding in an ATP-dependent manner, presumably by disrupting structure in the intermediate. These results highlight the tendency of RNAs to misfold, underscore the roles of CYT-19 and Mss116p as general RNA chaperones, and identify a refolding transition for further dissection of the roles of DEAD box proteins in RNA folding. 相似文献
296.
Marinho Fde A Gonçalves KC Oliveira SS Oliveira AC Bellio M d'Avila-Levy CM Santos AL Branquinha MH 《Memórias do Instituto Oswaldo Cruz》2011,106(4):507-509
In the current study, we evaluated the mechanism of action of miltefosine, which is the first effective and safe oral treatment for visceral leishmaniasis, in Leishmania amazonensis promastigotes. Miltefosine induced a process of programmed cell death, which was determined by the externalization of phosphatidylserine, the incorporation of propidium iodide, cell-cycle arrest at the sub-G0/G1 phase and DNA fragmentation into oligonucleosome-sized fragments. Despite the intrinsic variation that is detected in Leishmania spp, our results indicate that miltefosine causes apoptosis-like death in L. amazonensis promastigote cells using a similar process that is observed in Leishmania donovani. 相似文献
298.
Selma B de Nijs Niki Fens Rene Lutter Erica Dijkers Frans H Krouwels Barbara S Smids-Dierdorp Reindert P van Steenwijk Peter J Sterk 《Respiratory research》2011,12(1):11
Background
Eosinophilic airway inflammation has successfully been used to tailor anti-inflammatory therapy in chronic obstructive pulmonary disease (COPD). Airway hyperresponsiveness (AHR) by indirect challenges is associated with airway inflammation. We hypothesized that AHR to inhaled mannitol captures eosinophilia in induced sputum in COPD.Methods
Twenty-eight patients (age 58 ± 7.8 yr, packyears 40 ± 15.5, post-bronchodilator FEV1 77 ± 14.0%predicted, no inhaled steroids ≥4 wks) with mild-moderate COPD (GOLD I-II) completed two randomized visits with hypertonic saline-induced sputum and mannitol challenge (including sputum collection). AHR to mannitol was expressed as response-dose-ratio (RDR) and related to cell counts, ECP, MPO and IL-8 levels in sputum.Results
There was a positive correlation between RDR to mannitol and eosinophil numbers (r = 0.47, p = 0.03) and level of IL-8 (r = 0.46, p = 0.04) in hypertonic saline-induced sputum. Furthermore, significant correlations were found between RDR and eosinophil numbers (r = 0.71, p = 0.001), level of ECP (r = 0.72, p = 0.001), IL-8 (r = 0.57, p = 0.015) and MPO (r = 0.64, p = 0.007) in sputum collected after mannitol challenge. ROC-curves showed 60% sensitivity and 100% specificity of RDR for >2.5% eosinophils in mannitol-induced sputum.Conclusions
In mild-moderate COPD mannitol hyperresponsiveness is associated with biomarkers of airway inflammation. The high specificity of mannitol challenge suggests that the test is particularly suitable to exclude eosinophilic airways inflammation, which may facilitate individualized treatment in COPD.Trial registration
Netherlands Trial Register (NTR): NTR1283 相似文献299.
de Souza PA Matheus SM Castan EP Campos DH Cicogna AC Carvalho RF Dal-Pai-Silva M 《Journal of molecular histology》2011,42(6):557-565
HF is syndrome initiated by a reduction in cardiac function and it is characterized by the activation of compensatory mechanisms.
Muscular fatigue and dyspnoea are the more common symptoms in HF; these may be due in part to specific skeletal muscle myopathy
characterized by reduced oxidative capacity, a shift from slow fatigue resistant type I to fast less fatigue resistant type
II fibers and downregulation of myogenic regulatory factors (MRFs) gene expression that can regulate gene expression of nicotinic
acetylcholine receptors (nAChRs). In chronic heart failure, skeletal muscle phenotypic changes could influence the maintenance
of the neuromuscular junction morphology and nAChRs gene expression during this syndrome. Two groups of rats were studied:
control (CT) and Heart Failure (HF), induced by a single intraperitoneal injection of monocrotaline (MCT). At the end of the
experiment, HF was evaluated by clinical signs and animals were sacrificed. Soleus (SOL) muscles were removed and processed
for morphological, morphometric and molecular NMJ analyses. Our major finding was an up-regulation in the gene expression
of the alpha1 and epsilon subunits of nAChR and a spot pattern of nAChR in SOL skeletal muscle in this acute monocrotaline
induced HF. Our results suggest a remodeling of nAChR alpha1 and epsilon subunit during heart failure and may provide valuable
information for understanding the skeletal muscle myopathy that occurs during this syndrome. 相似文献
300.
Selma Waaijers Vincent Portegijs Jana Kerver Bennie B. L. G. Lemmens Marcel Tijsterman Sander van den Heuvel Mike Boxem 《Genetics》2013,195(3):1187-1191
The generation of genetic mutants in Caenorhabditis elegans has long relied on the selection of mutations in large-scale screens. Directed mutagenesis of specific loci in the genome would greatly speed up analysis of gene function. Here, we adapt the CRISPR/Cas9 system to generate mutations at specific sites in the C. elegans genome. 相似文献