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41.
Anas A Paul S Jayaprakash NS Philip R Bright Singh IS 《Diseases of aquatic organisms》2005,67(1-2):177-179
Chitosan is a biocompatible and biodegradable natural polymer with established antimicrobial properties against specific microorganisms. The present study demonstrates its antibacterial activity against 48 isolates of Vibrio species from prawn larval rearing systems. The antibacterial activity had a positive correlation with the concentration of chitosan. This work opens up avenues for using chitosan as a prophylactic biopolymer for protecting prawn larvae from vibriosis. 相似文献
42.
43.
Thomas?PresselEmail author Anas?Bouguecha Ute?Vogt Andrea?Meyer-Lindenberg Bernd-Arno?Behrens Ingo?Nolte Henning?Windhagen 《Biomedical engineering online》2005,4(1):66
After the publication of this work [1], we became aware of the fact that the frequency of the ultrasound transmitter that we used for determining the elastic moduli
of the trabecular bone specimens was not correctly specified. The oscillation frequency of the ultrasound transmitter was
2 MHz (and not 100 MHz as stated in our work) while we used a sampling rate of 100 MHz. In our publication, the oscillation
frequency and sampling rate were confounded. Therefore also the statement in the discussion that we might have determined
elastic moduli of trabecular bone tissue rather than the elastic properties of whole specimens because we used an ultrasound
frequency > 2 MHz is wrong and has to be omitted. 相似文献
44.
Pressel T Bouguecha A Vogt U Meyer-Lindenberg A Behrens BA Nolte I Windhagen H 《Biomedical engineering online》2005,4(1):17
Background
Studying mechanical properties of canine trabecular bone is important for a better understanding of fracture mechanics or bone disorders and is also needed for numerical simulation of canine femora. No detailed data about elastic moduli and degrees of anisotropy of canine femoral trabecular bone has been published so far, hence the purpose of this study was to measure the elastic modulus of trabecular bone in canine femoral heads by ultrasound testing and to assess whether assuming isotropy of the cancellous bone in femoral heads in dogs is a valid simplification. 相似文献45.
Moustafa AH Haggam RA Younes ME El Ashry ES 《Nucleosides, nucleotides & nucleic acids》2005,24(10-12):1885-1894
Reaction of L-tartaric acid with thiocarbohydcrazide afforded (1R, 2S)-1,2-bis(4-amino-5-mercapto-1,2,4-triazol-3-yl)-ethane-1,2-diol (3). The functional groups in 3 allowed the construction of fused heterocycles on the 1,2,4-triazole rings, mainly of the 1,2,4-triazolo[3,4-b][1,3,4]thiadiazine type as in 4, 5, 7, 10, 13 and 1,2,4-triazolo[3,4-b][1,3,4]thiadiazole type as in 14. 相似文献
46.
Maaroufi Y de Bruyne JM Duchateau V Scheen R Crokaert F 《FEMS immunology and medical microbiology》2006,48(2):183-191
A major pitfall in most published genomic amplification methods for the detection and identification of human pathogens is that they do not include an internal amplification control in order to achieve an acceptable level of confidence for the absence of false-negative results. By applying composite primer technology, a single multiple internal amplification control DNA molecule was constructed to detect and quantify the hepatitis B virus, human polyomavirus, Epstein-Barr virus, Toxoplasma gondii and cytomegalovirus using real-time PCR. The multiple internal amplification control contains all forward and reverse primer binding regions targeted in the five distinct duplex PCRs, but with a unique probe hybridization site. Multiple internal amplification control detection sensitivity, assessed by Probit analysis, was 58 copies per PCR, associated with an extremely wide dynamic range (8 log(10) units). Moreover, in testing 614 patient samples, PCR inhibition occurred at a frequency of 0-8.8%. Similar multiple internal amplification controls for quantitative PCR-based assays could be designed to accommodate any infectious profiles in a particular institution as they are easy to make and inexpensive. 相似文献
47.
Fabienne Meier-Abt Younes Mokrab Kenji Mizuguchi 《The Journal of membrane biology》2006,208(3):213-227
Organic anion-transporting polypeptides (human, OATPs; other animals, Oatps; gene symbol, SLCO/Slco) form a transport protein superfamily that mediates the translocation of amphipathic substrates across the plasma membrane
of animal cells. So far, OATPs/Oatps have been identified in human, rat and mouse tissues. In this study, we used bioinformatic
tools to detect new members of the OATP/SLCO superfamily in nonmammalian species and to build models for the three-dimensional structure of OATPs/Oatps. New OATP/SLCO superfamily members, some of which form distinct novel families, were identified in chicken, zebrafish, frog, fruit fly and
worm species. The lack of OATP/SLCO superfamily members in plants, yeast and bacteria suggests the emergence of an ancient Oatp protein in an early ancestor
of the animal kingdom. Structural models were generated for the representative members OATP1B3 and OATP2B1 based on the known
structures of the major facilitator superfamily of transport proteins. A model was also built for the large extracellular
region between transmembrane helices 9 and 10, following the identification of a novel homology with the Kazal-type serine
protease inhibitors. Along with the electrostatic potential and the conservation of key amino acid residues, we propose a
common transport mechanism for all OATPs/Oatps, whereby substrates are translocated through a central, positively charged
pore in a rocker-switch type of mechanism. Several amino acid residues were identified that may play crucial roles in the
proposed transport mechanism.
Electronic Supplementary Material Electronic Supplementary material is available for this article at
and accessible for authorised users. 相似文献
48.
We present a parametric family of regression models for interval-censored event-time (survival) data that accomodates both fixed (e.g. baseline) and time-dependent covariates. The model employs a three-parameter family of survival distributions that includes the Weibull, negative binomial, and log-logistic distributions as special cases, and can be applied to data with left, right, interval, or non-censored event times. Standard methods, such as Newton-Raphson, can be employed to estimate the model and the resulting estimates have an asymptotically normal distribution about the true values with a covariance matrix that is consistently estimated by the information function. The deviance function is described to assess model fit and a robust sandwich estimate of the covariance may also be employed to provide asymptotically robust inferences when the model assumptions do not apply. Spline functions may also be employed to allow for non-linear covariates. The model is applied to data from a long-term study of type 1 diabetes to describe the effects of longitudinal measures of glycemia (HbA1c) over time (the time-dependent covariate) on the risk of progression of diabetic retinopathy (eye disease), an interval-censored event-time outcome. 相似文献
49.
Sulieman Ibraheem Shelash Al-Hawary Anas Yahya Ali Yasser Fakri Mustafa Ria Margiana Shamsutdinova Maksuda Ilyasovna Montather F. Ramadan Sami G. Almalki Marim Alwave Safa Alkhayyat Ali Alsalamy 《Biotechnology progress》2023,39(6):e3383
Altered expression of multiple miRNAs was found to be extensively involved in the pathogenesis of different neurological disorders including Alzheimer's disease, Parkinson's disease, stroke, epilepsy, multiple sclerosis, amyotrophic lateral sclerosis, and Huntington's disease. One of the biggest concerns within gene-based therapy is the delivery of the therapeutic microRNAs to the intended place, which is obligated to surpass the biological barriers without undergoing degradation in the bloodstream or renal excretion. Hence, the delivery of modified and unmodified miRNA molecules using excellent vehicles is required. In this light, mesenchymal stem cells (MSCs) have attracted increasing attention. The MSCs can be genetically modified to express or overexpress a particular microRNA aimed with promote neurogenesis and neuroprotection. The current review has focused on the therapeutic capabilities of microRNAs-overexpressing MSCs to ameliorate functional deficits in neurological conditions. 相似文献
50.
Chokri A El Abida K Zegzouti YF Ben Cheikh R 《Canadian journal of physiology and pharmacology》2012,90(5):607-616
The vasodilatory effect of Globularia alypum L. (GA) extract was evaluated in rat mesenteric arterial bed pre-contracted by continuous infusion of phenylephrine (2-4 ng/mL). Bolus injections of GA elicited dose-response vasodilation, which was abolished after endothelium removal. Addition of a nitric oxide synthase inhibitor, N(G)-nitro-l-arginine methyl ester (100 μmol/L), alone or in the presence of a cyclooxygenase inhibitor, indomethacin (10 μmol/L), did not significantly affect the vasodilation of the mesenteric arterial bed in response to GA extract. These results suggest that GA-induced vasodilation is endothelium dependent but nitric oxide and prostacyclin independent. In the presence of high K(+) (60 mmol/L), the GA vasodilatory effect was completely abolished, suggesting that the vasodilation effect is mediated by hyperpolarization of the vascular cells. Also, pre-treatment with atropine (a muscarinic receptors antagonist) antagonized the GA-induced vasodilation, suggesting that the vasodilatory effect is mainly mediated by the endothelium-derived hyperpolarizing factor through activation of endothelial muscarinic receptors. 相似文献