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51.
Claudia Calabrese Marina Mangiulli Caterina Manzari Anna Maria Paluscio Mariano Francesco Caratozzolo Flaviana Marzano Ivana Kurelac Anna Maria D’Erchia Domenica D’Elia Flavio Licciulli Sabino Liuni Ernesto Picardi Marcella Attimonelli Giuseppe Gasparre Anna Maria Porcelli Graziano Pesole Elisabetta Sbisà Apollonia Tullo 《BMC genomics》2013,14(1)
52.
Shiga toxin 1 (Stx1) catalyses the removal of a specific adenine from 28S rRNA within ribosomes (RNA-N-glycosylase activity) and the removal of multiple adenines from DNA (DNA-glycosylase activity). For the in vitro activity the toxin requires activation by trypsin, urea and DTT which releases the enzymatically active A1 fragment. We show that activated Stx1 acts on DNA as a heat-stable enzyme. Moreover, heat-treatment of the pro-enzyme at acidic pH turns it into an enzymatically active species which efficiently depurinates DNA. Although the effect of this treatment is centred on the enzyme and not on DNA, we found no evidence for covalent modification of the holotoxin. We suggest that high temperatures and acidic buffer induce unfolding of the holotoxin allowing the substrate to gain access to the active site. Possible practical applications (rapid assay for Stx1 detection, use of the toxin for DNA sequencing) are discussed. 相似文献
53.
Currò M Marini H Alibrandi A Ferlazzo N Condello S Polito F Adamo EB Atteritano M D'Anna R Altavilla D Bitto A Squadrito F Ientile R Caccamo D 《The Journal of steroid biochemistry and molecular biology》2011,127(3-5):413-417
Multiple factors may contribute to the pathogenesis of postmenopausal osteoporosis including environmental, life-style and genetic factors. Common variants in ESR2 gene encoding for ER-beta, highly expressed in bone tissue, have recently been proposed as candidates for affecting bone phenotype at the population level, particularly in postmenopausal women. In this study, we examined the genetic background at ESR2 AluI (rs4986938, 1730G>A) locus in 89 osteopenic, postmenopausal women (age range 49-56 years) together with BMD at lumbar spine and femoral neck sites as well as variations in plasma levels of bone metabolism and turnover markers. Genotyping for ESR2 G1730A polymorphism showed that the frequency of A mutated allele accounted for 0.4 in our cohort of postmenopausal women; moreover, the GA1730 heterozygous individuals were the most represented (50.6%) compared with GG (37.8%) and AA homozygous ones (14.6%). A regression analysis showed that lumbar spine BMD values were significantly associated with both ESR2 AA1730 genotype (p=0.044) and time since the onset of menopause (p=0.031), while no significant association was detected between biochemical markers and genetic background. Interestingly, 85% of patients with AA1730 genotype presented the smallest lumbar spine BMD values. These findings first indicate a worsening effect of ESR2 AluI polymorphism on lumbar spine BMD reduction in postmenopause, suggesting that the detection of this ESR2 variant should be recommended in postmenopausal women, particularly in populations with a high prevalence of ESR2 AA1730 homozygous genotype. 相似文献
54.
Angelica Del Giudice Domenica R. Massardo Filomena Manna Natalia Koltovaya Hans Hartings Luigi Del Giudice Klaus Wolf 《Current microbiology》1997,34(6):382-384
In previous papers (Del Giudice et al. Curr Genet
8:493–497, 1984; Massardo et al. Curr Genet 17:455–457, 1985) we have shown
that strains of Saccharomyces cerevisiae that are devoid of
mitochondrial DNA (rho
o) are resistant to the alkaloid
lycorine isolated from Amaryllis plants, whereas strains containing
mitochondrial DNA (rho
−
, mit
−
,
or rho
+
) are sensitive to this drug. In addition, we were
able to show that the so-called hypersuppressive petites, whose mitochondrial
genomes consist of short regions of DNA containing an ori sequence,
show intermediate resistance. In this paper, we demonstrate that the degree
of suppressiveness of a rho
− mutant correlates with the
degree of resistance to lycorine.
Received: 20 September 1996 / Accepted: 10 January 1997 相似文献
55.
Biancamaria Farina Annarita Del Gatto Daniela Comegna Sonia Di Gaetano Domenica Capasso Carla Isernia Michele Saviano Roberto Fattorusso Laura Zaccaro Luigi Russo 《Journal of peptide science》2019,25(5)
Integrins are heterodimeric cell‐surface proteins that play important roles during developmental and pathological processes. Diverse human pathologies involve integrin adhesion including thrombotic diseases, inflammation, tumour progression, fibrosis, and infectious diseases. Although in the past decade, novel integrin‐inhibitor drugs have been developed for integrin‐based medical applications, the structural determinants modulating integrin‐ligands recognition mechanisms are still poorly understood, reducing the number of integrin subtype exclusive antagonists. In this scenario, we have very recently showed, by means of chemical and biological assays, that a chimeric peptide (named RGDechi), containing a cyclic RGD motif linked to an echistatin C‐terminal fragment, is able to interact with the components of integrin family with variable affinities, the highest for αvβ3. Here, in order to understand the mechanistic details driving the molecular recognition mechanism of αvβ3 by RGDechi, we have performed a detailed structural and dynamics characterization of the free peptide by natural abundance nuclear magnetic resonance (NMR) spectroscopy. Our data indicate that RGDechi presents in solution an heterogeneous conformational ensemble characterized by a more constrained and rigid pentacyclic ring and a largely unstructured acyclic region. Moreover, we propose that the molecular recognition of αvβ3 integrin by RGDechi occurs by a combination of conformational selection and induced fit mechanisms. Finally, our study indicates that a detailed NMR characterization, by means of natural abundance 15N and 13C, of a mostly unstructured bioactive peptide may provide the molecular basis to get essential structural insights into the binding mechanism to the biological partner. 相似文献
56.
Discovery and structure–activity relationship of a novel spirocarbamate series of NPY Y5 antagonists
Colin P. Leslie Jonathan Bentley Matteo Biagetti Stefania Contini Romano Di Fabio Daniele Donati Thorsten Genski Sebastien Guery Angelica Mazzali Giancarlo Merlo Domenica A. Pizzi Fabiola Sacco Catia Seri Michela Tessari Laura Zonzini Laura Caberlotto 《Bioorganic & medicinal chemistry letters》2010,20(20):6103-6107
A novel series of trans-8-aminomethyl-1-oxa-3-azaspiro[4.5]decan-2-one derivatives was identified with potent NPY Y5 antagonist activity. Optimization of the original lead furnished compounds 23p and 23u, which combine sub-nanomolar Y5 activity with metabolic stability, oral bioavailability, brain penetration and strong preclinical profile for development. Both compounds significantly inhibited the food intake induced by a Y5 selective agonist with minimal effective doses of 3 mg/kg po. 相似文献
57.
Kozarov E Sweier D Shelburne C Progulske-Fox A Lopatin D 《Microbes and infection / Institut Pasteur》2006,8(3):687-693
This is the first study to analyze atheromatous plaques for the presence of bacterial DNA from ten species, including periodontal species and Chlamydia pneumoniae. We examined 129 samples of DNA extracted from atheromas from 29 individuals for the presence of bacterial 16S rDNA sequences from ten different species: Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans (A.a.), Tannerella forsythensis, Eikenella corrodens, Prevotella intermedia, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus mutans, Treponema denticola and C. pneumoniae. All determinations were made using real-time quantitative polymerase chain reaction (PCR) methods employing SYBR Green. Species from the Bacteroides family were found in about 17% of the young but approximately 80% in elderly patients. Almost half of the samples contained DNA from A. a. and C. pneumoniae, although the proportion of the latter was minimal. S. aureus and S. epidermidis were found with the lowest frequency, 5 and 10%, respectively. S. mutans was found in approximately 20% of the samples. The proportions of each bacterial species were calculated relative to the total amount of prokaryotic DNA. The data support our previous findings of an association between periodontal organisms and vascular inflammation. We conclude that DNA from oral infectious agents is commonly found in atheromas from young but especially from elderly subjects, and that the contribution of C. pneumoniae to the inflammation may be minimal. 相似文献
58.
59.
Herbert Marini Monica Currò Elena B. Adamo Francesca Polito Nadia Ferlazzo Alessandra Bitto Marco Atteritano Rosario D'Anna Angela Alibrandi Domenica Altavilla Francesco Squadrito Riccardo Ientile Daniela Caccamo 《Gene》2012
The incidence of cardiovascular disease (CVD) and resultant morbidity and mortality are highly increased in postmenopausal women. Recent observations indicate the involvement of estrogen receptor beta in the pathogenesis of CVD, and the potential role of ESR2 gene polymorphisms as independent risk factors for CVD. We aimed to investigate the possible association between the ESR2 AluI 1730G>A gene polymorphism (rs4986938) with different CVD risk markers, such as body mass index (BMI), blood fibrinogen, glucose and insulin, homeostasis model assessment of insulin resistance and urinary F2-isoprostanes, in 89 postmenopausal women. Genotyping for ESR2 1730G>A polymorphism showed the higher prevalence of heterozygous GA1730 genotype than either wild-type GG1730 or homozygously mutated AA1730 genotype (50.6 vs 34.8 or 14.6%, respectively). Statistical analysis of between-group variability revealed that mean levels of the examined CVD risk markers, except BMI and fibrinogen, were within the normal range in all subjects grouped to different ESR2 1730G>A genotypes. Interestingly, only fibrinogen levels were statistically different in AA1730 carriers compared with other genotypes. The analysis of genotype relative risk showed a significant elevation of plasma fibrinogen in AA1730 carriers compared with GG + GA ones. The present data strongly indicate that genotyping for the ESR2 AluI 1730G>A gene variant should be included in a screening panel for assessment of cardiovascular risk in menopausal women. 相似文献
60.
Beatriz Gonçalves Odrade Nougué Florian Jabbour Céline Ridel Halima Morin Patrick Laufs Domenica Manicacci Catherine Damerval 《The Plant journal : for cell and molecular biology》2013,76(2):223-235
Flower architecture mutants provide a unique opportunity to address the genetic origin of flower diversity. Here we study a naturally occurring floral dimorphism in Nigella damascena (Ranunculaceae), involving replacement of the petals by numerous sepal‐like and chimeric sepal/stamen organs. We performed a comparative study of floral morphology and floral development, and characterized the expression of APETALA3 and PISTILLATA homologs in both morphs. Segregation analyses and gene silencing were used to determine the involvement of an APETALA3 paralog (NdAP3–3) in the floral dimorphism. We demonstrate that the complex floral dimorphism is controlled by a single locus, which perfectly co‐segregates with the NdAP3–3 gene. This gene is not expressed in the apetalous morph and exhibits a particular expression dynamic during early floral development in the petalous morph. NdAP3–3 silencing in petalous plants perfectly phenocopies the apetalous morph. Our results show that NdAP3–3 is fully responsible for the complex N. damascena floral dimorphism, suggesting that it plays a role not only in petal identity but also in meristem patterning, possibly through regulation of perianth organ number and the perianth/stamen boundary. 相似文献