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241.
ObjectiveThe present study aims to simulate an alarm system for online detecting normal electrocardiogram (ECG) signals from abnormal ECG so that an individual's heart condition can be accurately and quickly monitored at any moment, and any possible serious dangers can be prevented.Materials and methodsFirst, the data from Physionet database were used to analyze the ECG signal. The data were collected equally from both males and females, and the data length varied between several seconds to several minutes. The heart rate variability (HRV) signal, which reflects heart fluctuations in different time intervals, was used due to the low spatial accuracy of ECG signal and its time constraint, as well as the similarity of this signal with the normal signal in some diseases. In this study, the proposed algorithm provided a return map as well as extracted nonlinear features of the HRV signal, in addition to the application of the statistical characteristics of the signal. Then, artificial neural networks were used in the field of ECG signal processing such as multilayer perceptron (MLP) and support vector machine (SVM), as well as optimal features, to categorize normal signals from abnormal ones.ResultsIn this paper, the area under the curve (AUC) of the ROC was used to determine the performance level of introduced classifiers. The results of simulation in MATLAB medium showed that AUC for MLP and SVM neural networks was 89.3% and 94.7%, respectively. Also, the results of the proposed method indicated that the more nonlinear features extracted from the ECG signal could classify normal signals from the patient.ConclusionThe ECG signal representing the electrical activity of the heart at different time intervals involves some important information. The signal is considered as one of the common tools used by physicians to diagnose various cardiovascular diseases, but unfortunately the proper diagnosis of disease in many cases is accompanied by an error due to limited time accuracy and hiding some important information related to this signal from the physicians' vision leading to the risks of irreparable harm for patients. Based on the results, designing the proposed alarm system can help physicians with higher speed and accuracy in the field of diagnosing normal people from patients and can be used as a complementary system in hospitals. 相似文献
242.
S. M. Hosseini M. Fazilati F. Moulavi M. Foruzanfar M. Hajian P. Abedi N. Nasiri A. K. Kaveh A. H. Shahverdi M. R. Hemami M. H. Nasr-Esfahani 《European Journal of Wildlife Research》2009,55(3):239-246
Although the potential use of reproductive biotechnology for safeguarding of endangered wildlife species is undoubted, initial
evaluation of the genetic and reproductive relationship between the endangered mammals and those closely related species is
indispensable. Isfahan mouflon Ovis orientalis isphahanica is now considered as a threatened species by International Union for the Conservation of Nature. Therefore, little is known
about the biology of this species. This study was carried out to investigate the possible reproductive potential of domestic
sheep for ex situ conservation of the Isfahan mouflon. Somatic cell cultures were taken from ear biopsies of the wild and
domestic sheep and were used for karyotype analysis. Semen samples were collected by electroejaculator from the wild and domestic
rams. The spermatological characteristics of the collected semen samples were determined and used for both cryopreservation
and cross-insemination of the synchronized wild and domestic female sheep. To establish a cryobank for the threatened species
biomaterials, freezed samples of the somatic cells and semen were transferred to a cryotank. The result suggested that Isfahan
mouflon has conserved its chromosomal integrity as previously observed and contains the same chromosomal number as the domestic
sheep (2n = 54). The semen samples of both species revealed similar cryoviability (>35% gross motility postthawing). Cross-insemination
of both species resulted in successful pregnancy. It was suggested that domestic sheep possesses the required biological characteristics
to be considered for safeguarding of the Isfahan mouflon. 相似文献
243.
Topical non-iontophoretic application of acetylcholine and nitroglycerin via a translucent patch: a new means for assessing microvascular reactivity
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Schonberger RB Worden WS Shahmohammadi K Menn K Silverman TJ Stout RG Shelley KH Silverman DG 《The Yale journal of biology and medicine》2006,79(1):1-7
Objective: Assessments of endothelial cell function with acetylcholine have typically used systemic, regional intra-arterial, or iontophoretic delivery of drug. Each of these techniques induces systemic and/or local changes that compromise their safety or effectiveness. Using translucent drug preparations applied under laser Doppler flowmetry (LDF) probes, we tested whether local vasodilation can be induced with non-iontophoretic transdermal delivery of acetylcholine and how such dilation would compare to the dilation achieved with topical nitroglycerin in healthy volunteers. Methods: Ten subjects without known vascular disease were recruited for LDF monitoring at sites of drug application for this preliminary investigation. Topical acetylcholine chloride, nitroglycerin, and placebo were applied via translucent patches to the forehead directly below LDF probes. Results: LDF readings increased by 406 percent (245 percent to 566 percent) and 36 percent (26 percent to 46 percent), respectively, at the acetylcholine and placebo sites (p = .005 by Wilcoxon Signed Rank Test (WSRT) for acetylcholine vs. placebo); and they increased by 365 percent (179 percent to 550 percent) at the nitroglycerin site (p = .005 by WSRT for nitroglycerin vs. placebo; p = .6 vs. acetylcholine). Conclusion: Transdermal delivery of acetylcholine can induce significant local vasodilatory responses comparable to those achieved with nitroglycerin without requiring iontophoresis. The means of transdermal delivery and monitoring described herein may constitute a new minimally invasive way to interrogate the microvasculature and thereby assess the microcirculatory changes induced by various disorders and therapeutic interventions. 相似文献
244.
O'Brien TJ Jiang G Chun G Mandel HG Westphal CS Kahen K Montaser A States JC Patierno SR 《Mutation research》2006,610(1-2):85-92
Some hexavalent chromium [Cr(VI)]-containing compounds are lung carcinogens. Once within cells, Cr(VI) is reduced to trivalent chromium [Cr(III)] which displays an affinity for both DNA bases and the phosphate backbone. A diverse array of genetic lesions is produced by Cr including Cr-DNA monoadducts, DNA interstrand crosslinks (ICLs), DNA-Cr-protein crosslinks (DPCs), abasic sites, DNA strand breaks and oxidized bases. Despite the large amount of information available on the genotoxicity of Cr, little is known regarding the molecular mechanisms involved in the removal of these lesions from damaged DNA. Recent work indicates that nucleotide excision repair (NER) is involved in the processing of Cr-DNA adducts in human and rodent cells. In order to better understand this process at the molecular level and begin to identify the Cr-DNA adducts processed by NER, the incision of CrCl(3) [Cr(III)]-damaged plasmid DNA was studied using a thermal-resistant UvrABC NER endonuclease from Bacillus caldotenax (Bca). Treatment of plasmid DNA with Cr(III) (as CrCl(3)) increased DNA binding as a function of dose. For example, at a Cr(III) concentration of 1 microM we observed approximately 2 Cr(III)-DNA adducts per plasmid. At this same concentration of Cr(III) we found that approximately 17% of the plasmid DNA contained ICLs ( approximately 0.2 ICLs/plasmid). When plasmid DNA treated with Cr(III) (1 microM) was incubated with Bca UvrABC we observed approximately 0.8 incisions/plasmid. The formation of endonuclease IV-sensitive abasic lesions or Fpg-sensitive oxidized DNA bases was not detected suggesting that the incision of Cr(III)-damaged plasmid DNA by UvrABC was not related to the generation of oxidized DNA damage. Taken together, our data suggest that a sub-fraction of Cr(III)-DNA adducts is recognized and processed by the prokaryotic NER machinery and that ICLs are not necessarily the sole lesions generated by Cr(III) that are substrates for NER. 相似文献
245.
12 new heterocyclic compounds containing methoxy groups and/or amine side chain residues have been synthesized and 1 had some activity in an antiimplantation assay. The compounds included 7 4-(substituted aminomethyl)5,6,7-trimethoxy phthalid methiodides and 5 1-N-aminoacetylbenz[1,6]diazocin-5-ones. 50% anti-implantational activity was observed on a morpholino compound, 4-(4-morpholinomethyl)-5,6,7-trimethoxy phthalid methiodide. 相似文献
246.
Light-induced Changes in the Pattern of Protein Synthesis during the Early Stages of Greening of Etiolated Maize Leaves 总被引:4,自引:3,他引:1
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The effect of light on protein synthesis during the early stages of greening of etiolated maize (Zea mays) leaves was studied using double labeling with leucine and fractionation of proteins by gel filtration and acrylamide gel electrophoresis. The incorporation of labeled leucine into a relatively small number of plastid proteins is effected within the first 30 to 60 minutes of illumination. These proteins do not accumulate with time. When illumination is prolonged, additional proteins are effected. 相似文献
247.
Polyamine oxidase (EC 1.5.3.3) activity has not been detected previously in cells of dicotyledonous plants, although it has been characterized extensively in monocotyledonous plants. Evidence is presented in this report for the occurrence of polyamine oxidase in dialyzed crude extracts of the dicotyledonous plant, Medicago sativa L. (alfalfa). Three enzyme assays were used to quantitate the formation of the three products of the reaction catalyzed by polyamine oxidase. 1-Pyrroline formation was measured colorimetrically as a yellow quinazolinium complex with o-aminobenzaldehyde. Hydrogen peroxide formation was measured spectrophotometrically with a coupled peroxidase assay system by peroxidative oxidation of guaiacol. [3H]1,3-Diaminopropane formation was measured by using [1,8-3H]spermidine as the substrate and separating the radiolabelled reaction product from the substrate by paper electrophoresis. This latter assay provided evidence that a polyamine oxidase of type [EC 1.5.3.3] catalyzed the cleavage reaction between a secondary nitrogen atom and an adjacent carbon of the butyl moiety of spermidine. Significant polyamine oxidase activity was detected in floral tissues, cortex tissues of the root, young leaves, and young germinated seedlings of alfalfa. The occurrence of polyamine oxidase in alfalfa accounts for the formation of the essential substrate, 1,3-diaminopropane, required for the biosynthesis of the uncommon polyamines, norspermidine and norspermine, which we have recently detected in alfalfa.Abbreviations PAO
polyamine oxidase
- MOPS
[3-(N-morpholino)propanesulfonic acid]
- MES
[2-(N-morpholino)ethanesulfonic acid]
- TES
[N-tris (hydroxymethyl)methyl-2-aminoethanesulfonic acid]
- BICINE
[N,N-bis (2-hydroxyethyl)glycine]
- DTC
diethyldithiocarbamic acid
- Rm
the distance of migration of a polyamine relative to putrescine after electrophoresis on paper 相似文献
248.
The effects of 0, 2.5, 5.0, and 10.0 mg(Cd2+) m-3 [Cd(NO3)2×4 H2O] and 0 and 10.0 mg m-3 gibberellin on certain parameters of photosynthesis and growth in soybean (Glycine max L. cv. Pershing) plants were studied. With increasing Cd2+ concentration in the Hoagland nutrient solution, the contents of chlorophyll and CO2 compensation concentration decreased. The addition of 10 mg m-3 gibberellin reduced the negative effects of Cd2+ in shoot and root growth. With increasing of Cd2+ concentration in the culture medium, the dry matter production in both the roots and shoots decreased as shown by the decline in growth rate (PGR), net assimilation rate (NAR), and leaf area ratio. The addition of gibberellin caused a partial elimination of the Cd effects on the roots and shoots and the PGR and NAR and it increased leaf area and length of stem. 相似文献
249.
Ghaffari A Li Y Karami A Ghaffari M Tredget EE Ghahary A 《Journal of cellular biochemistry》2006,98(2):383-393
Termination of wound-healing process requires a fine balance between connective tissue deposition and its hydrolysis. Previously, we have demonstrated that keratinocyte-releasable stratifin, also known as 14-3-3 sigma protein, stimulates collagenase (MMP-1) expression in dermal fibroblasts. However, role of extracellular stratifin in regulation of extracellular matrix (ECM) factors and other matrix metalloproteinases (MMPs) in dermal fibroblast remains unexplored. To address this question, large-scale ECM gene expression profile were analyzed in human dermal fibroblasts co-cultured with keratinocytes or treated with recombinant stratifin. Superarray pathway-specific microarrays were utilized to identify upregulation or downregulation of 96 human ECM and adhesion molecule genes. RT-PCR and Western blot were used to validate microarray expression profiles of selected genes. Comparison of gene profiles with the appropriate controls showed a significant (more than twofold) increase in expression of collagenase-1, stromelysin-1 and -2, neutrophil collagenase, and membrane type 5 MMP in dermal fibroblasts treated with stratifin or co-cultured with keratinocytes. Expression of type I collagen and fibronectin genes decreased in the same fibroblasts. The results of a dose-response experiment showed that stratifin stimulates the expression of stromelysin-1 (MMP-3) mRNA by dermal fibroblasts in a concentration-dependent fashion. Furthermore, Western blot analysis of fibroblast-conditioned medium showed a peak in MMP-3 protein levels 48 h following treatment with recombinant stratifin. In a lasting-effect study, MMP-3 protein was detected in fibroblast-condition medium for up to 72 h post removal of stratifin. In conclusion, our results suggest that keratinocyte-releasable stratifin plays a major role in induction of ECM degradation by dermal fibroblasts through stimulation of key MMPs, such as MMP-1 and MMP-3. Therefore, stratifin protein may prove to be a useful target for clinical intervention in controlling excessive wound healing in fibrotic conditions. 相似文献
250.
Design, synthesis, and biological evaluation of substituted 3-alkylthio-4,5-diaryl-4H-1,2,4-triazoles as selective COX-2 inhibitors 总被引:1,自引:0,他引:1
Navidpour L Shafaroodi H Abdi K Amini M Ghahremani MH Dehpour AR Shafiee A 《Bioorganic & medicinal chemistry》2006,14(8):2507-2517
A new type of 4,5-diaryl-4H-1,2,4-triazole, possessing C-3 thio and alkylthio (SH, SMe or SEt) substituents, was designed and synthesized for evaluation as selective cyclooxygenase-2 (COX-2) inhibitors with in vivo anti-inflammatory activity. The compound, 3-ethylthio-5-(4-fluorophenyl)-4-(4-methylsulfonylphenyl)-4H-1,2,4-triazole (10d), exhibited a high in vitro selectivity (COX-1 IC50=20.5 nM; COX-2 IC50=1.8 nM; SI=11.39) relative to the reference drug celecoxib (COX-1 IC50=3.7 nM; COX-2 IC50=2.2 nM; SI=1.68) and also showed good anti-inflammatory activity compared to celecoxib in a carrageenan-induced rat paw edema assay. 相似文献