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91.
Tao Q  Yokota C  Puck H  Kofron M  Birsoy B  Yan D  Asashima M  Wylie CC  Lin X  Heasman J 《Cell》2005,120(6):857-871
Wnt signaling pathways play essential roles in patterning and proliferation of embryonic and adult tissues. In many organisms, this signaling pathway directs axis formation. Although the importance of intracellular components of the pathway, including beta-catenin and Tcf3, has been established, the mechanism of their activation is uncertain. In Xenopus, the initiating signal that localizes beta-catenin to dorsal nuclei has been suggested to be intracellular and Wnt independent. Here, we provide three lines of evidence that the pathway specifying the dorsal axis is activated extracellularly in Xenopus embryos. First, we identify Wnt11 as the initiating signal. Second, we show that activation requires the glycosyl transferase X.EXT1. Third, we find that the EGF-CFC protein, FRL1, is also essential and interacts with Wnt11 to activate canonical Wnt signaling.  相似文献   
92.
Phytochemical studies on the ethanolic extract of the roots of Buxus sempervirens of Turkish origin have resulted in the isolation of two new triterpenoidal alkaloids, (+)-16a, 31-diacetylbuxadine (1), (-)-Nb-demethylcyclomikuranine (2) along with three known natural products, (-)-cyclomikuranine (3), (-)-cyclobuxophylline-K (4) and (+)-buxaquamarine (5) isolated for the first time from this species of genus Buxus. The structures of these new natural products were established on the basis of extensive spectroscopic studies. Compound 1 exhibited antibacterial activity against human pathogenic bacteria and weak phytotoxic activity against Lemna minor Linn.  相似文献   
93.
Length–weight relationship parameters of the form W = aLb are presented for 24 fish species from the North Aegean Sea: Scyliorhinus canicula, Mustelus mustelus, Squalus acanthias, Torpedo marmorata, Dipturus oxyrinchus, Raja clavata, R. miraletus, Dasyatis pastinaca, Gymnura altavela, Myliobatis aquila, Chimaera monstrosa, Conger conger, Argentina sphyraena, Chlorophthalmus agassizi, Caelorinchus caelorhincus, Gadiculus argenteus argenteus, Phycis blennoides, Hoplostethus mediterraneus, Capros aper, Macroramphosus scolopax, Helicolenus dactylopterus, Peristedion cataphractum, Lesueurigobius friesii and Lepidopus caudatus.  相似文献   
94.
A fimbrial adhesin, designated F1845, was found to be responsible for the diffuse HEp-2 cell adherence of a diarrheal Escherichia coli isolate. The genetic determinant of F1845 was cloned, and the order of the genes necessary for production of F1845 was determined by maxicell analysis. Five polypeptides with apparent sizes of 10, 95, 27, 15.5, and 14.3 kilodaltons (kDa) were found to be encoded in that order by the F1845 determinant. The nucleotide sequence of the 14.3-kDa subunit gene was determined and found to share extensive homology in its signal sequence with the gene encoding the structural subunit of the AFA-1 hemagglutinin of a uropathogenic E. coli strain (A. Labigne-Roussel, M.A. Schmidt, W. Walz, and S. Falkow, J. Bacteriol. 162:1285-1292, 1985) but not in the region encoding the mature protein. Southern blot hybridizations indicated that the F1845 determinants are of chromosomal origin. Hybridization studies using a probe from the region encoding the 95-kDa polypeptide indicated that related sequences may be plasmid associated in some strains and chromosomal in others. Additional hybridization studies of E. coli isolates possessing sequence homology to the F1845 determinant suggest that the sequences in the 5' region of the F1845 structural subunit gene are more highly conserved than sequences in the 3' region.  相似文献   
95.
Gagea genus, which is native to the Mediterranean and Black Sea regions, has attracted significant attention due to its biodiversity and potential health benefits. In this study, the biochemical composition and biological activities of methanol extracts from various parts of G. taurica were investigated, along with their anatomical and morphological characteristics. The best antimicrobial activity was found to be MeOH extracts of corm and leaf against several Candida strains with MIC=640 μg/mL. The highest level of phenolics together with significant results of antioxidant activities were observed in flowers extracts. The α-amylase inhibition assay results showed that the highest inhibition percentage was observed with acarbose (59 %), followed by leaf extract (43 %). Leaf exhibited the most effective inhibitory activity in AChE inhibition assay, whereas flower demonstrated the most significant inhibitory activity in BChE inhibition assay. Hesperidin was found as 1621.0001 ng/ml value in flower extract and 283.9339 ng/ml value leaf.  相似文献   
96.
Objective: To test whether a commercial weight loss program promotes greater weight loss in overweight or obese women compared with control conditions and to describe the effect on plasma lipids, carotenoids, hormones, and fitness. Research Methods and Procedures: Overweight or obese women were randomized to commercial weight loss program or control conditions (n = 35 each). Results: At randomization, participants were 41.1 (11.4) (mean [standard deviation]) years, BMI 34.0 (3.5) kg/m2, and weight 92.0 (11.1) kg. At 6 months, change in weight by intent‐to‐treat (ITT) analysis was ?7.2 (6.7) kg and ?7.8% (7.2%) in the intervention group vs. ?0.3 (3.9) kg and ?0.3% (4.5%) in the control group (n = 35 for each; p < 0.01). One‐year ITT analysis revealed significantly greater change in weight, percent weight, BMI, and waist and hip circumferences in the intervention vs. control group. Completers at 1 year exhibited change in weight of ?7.3 (10.4) kg for the intervention group (n = 32) vs. ?0.7 (5.6) kg for controls (n = 33) (p < 0.01), and ?7.8% (11.1%) weight change for the intervention group vs. ?0.7% (6.2%) for controls (p < 0.01). High‐density lipoprotein (HDL) cholesterol concentration increased significantly in the intervention group. Fasting serum insulin decreased in the intervention but increased in the control group at 6 months (p < 0.01), remaining different at 1 year (p = 0.05). Discussion: The commercial program successfully facilitated weight loss, which was notably maintained at 1 year, and promoted favorable changes in plasma lipid and hormone concentrations.  相似文献   
97.

Background  

Independently derived expression profiles of the same biological condition often have few genes in common. In this study, we created populations of expression profiles from publicly available microarray datasets of cancer (breast, lymphoma and renal) samples linked to clinical information with an iterative machine learning algorithm. ROC curves were used to assess the prediction error of each profile for classification. We compared the prediction error of profiles correlated with molecular phenotype against profiles correlated with relapse-free status. Prediction error of profiles identified with supervised univariate feature selection algorithms were compared to profiles selected randomly from a) all genes on the microarray platform and b) a list of known disease-related genes (a priori selection). We also determined the relevance of expression profiles on test arrays from independent datasets, measured on either the same or different microarray platforms.  相似文献   
98.
The main function of vitamin K1 is to act a co-factor for gamma-glutamyl carboxylase. However, it has also been shown to lessen oxidative stress. This study was aimed to evaluate the effect of vitamin K1 supplementation on vascular responsiveness and oxidative status in rats that underwent femoral osteotomy. Twenty-four male rats were divided into three groups to serve as sham, osteotomy and vitamin K1 groups. Indices of oxidative stress (catalase), and oxidative damage (malondialdehyde) were analysed in erythrocytes. In order to evaluate vascular reactivity, concentration-response curves to phenylephrine, angiotensin II, 5-hydroxytryptamine, bradykinin and histamine were constructed. The findings of this study clearly show that oxidative stress clearly increases after femoral osteotomy in rats. Also, this operation causes a significant depression in vascular responsiveness to contracting agents and endothelium-dependent vasodilators. However, vitamin K1 supplementation prevents vascular hyporeactivity by reducing oxidative stress and may represent a novel approach during osteotomy healing.  相似文献   
99.
We investigated the effects of paraoxonase (PON1) 192 polymorphism on serum PON1 activity and the impact of phenotypic expression on the risk and prognosis of Turkish children with membranoproliferative glomerulonephritis (MPGN). Eighteen children with biopsy-proven Type I MPGN (10 boys, 8 girls) and age-matched 53 healthy controls were included in the study. PCR (polymerase chain reaction), RFLP (restriction fragment length polymorphism) and agarose gel electrophoresis techniques were used to determine the PON1 192 genotype. PON1 activity was measured by spectrophotometric assay of p-nitrophenol production following addition of paraoxon. We found that PON1 192 genotype distribution (AA, AB, BB) in MPGN patients were 61.1%, 22.3%, 16.6% and 15.1%, 35.8%, 49.1% in controls, respectively. The frequency of AA genotypes was significantly higher in the MPGN group (0.611) compared with the healthy controls (0.151) (p < 0.001). Although the serum PON1 activity was lower in MPGN patients (103.3 +/- 55.2 U/l) than the healthy controls (130.9 +/- 71.2 U/mol), the difference was not statistically significant (p = 0.0563). In the genotypes of patients and controls classified according to PON1 A/B polymorphism; serum PON1 activities were significantly increased (p < 0.001, ANOVA) in the order of PON1 AA, AB and BB in both MPGN patients (82.4, 91.7 and 173.6 U/l) and healthy controls (85.9, 119.9 and 193.1 U/l), respectively. There was a significant relationship between the poor prognosis and having AA genotype and low PON1 activity. Of the 8 patients with poor prognosis, 7 had genotype AA and the remaining one was AB heterozygote. Our results suggest that homozygosity for the A allele might have an important role on the risk for developing MPGN and may also be associated with the poor prognosis of disease. In conclusion, we suggest that the PON1 activities are affected by PON1 genetic variability in Turkish patients with MPGN.  相似文献   
100.
In the current study, 33 isoquinoline alkaloids belonging to protopine-, benzylisoquinoline-, benzophenanthridine-, spirobenzylisoquinoline-, phthalideisoquinoline-, aporphine-, protoberberine-, cularine-, and isoquinolone-types as well as 7 derivatives of them obtained from some Fumaria and Corydalis species growing in Turkey have been evaluated for their in vitro antiviral and antimicrobial activities. Both DNA virus Herpes simplex (HSV) and RNA virus Parainfluenza (PI-3) were employed for antiviral assessment of the compounds using Madine-Darby bovine kidney and Vero cell lines and their maximum non-toxic concentrations (MNTC) and cytopathogenic effects (CPE) were determined using acyclovir and oseltamivir as the references. Antibacterial and antifungal activities of the alkaloids were tested against Escherichia coli, Pseudomonas aeruginosa, Proteus mirabilis, Klebsiella pneumoniae, Acinetobacter baumannii, Staphylococcus aureus, Bacillus subtilis, and Candida albicans by the microdilution method and compared to ampicilline, ofloxacine, and ketocanazole as the references. The alkaloids did not present any notable antibacterial effect, while they had significant antifungal activity at 8 microg/ml concentration. On the other hand, the alkaloids were found to have selective inhibition against the PI-3 virus ranging between 0.5 and 64 microg/ml as minimum and maximum CPE inhibitory concentrations, whereas they were completely inactive towards HSV.  相似文献   
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