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Early prediction of paroxysmal atrial fibrillation based on short-term heart rate variability

Narin, Ali | İşler, Yalçın | Özer, Mahmut | Perc, Matjaž

Article | 2018 | Physica A: Statistical Mechanics and its Applications509 , pp.56 - 65

Atrial fibrillation (AF) is the most common arrhythmia type and its early stage is paroxysmal atrial fibrillation (PAF). PAF affects negatively the quality of life by causing dyspnea, chest pain, feeling of excessive fatigue, and dizziness. In this study, our aim is to predict the onset of paroxysmal atrial fibrillation (PAF) events so that patients can take precautions to prevent PAF events. We use an open data from Physionet, Atrial Fibrillation Prediction Database. We construct our approach based on the heart rate variability (HRV) analysis. Short-term HRV analysis requires 5-minute data so that each dataset was divided into 5-mi . . .nute data segments. HRV features for each segment are calculated from time-domain measures and frequency-domain measures using power spectral density estimations of fast Fourier transform, Lomb–Scargle, and wavelet transform methods. Different combinations of these HRV features are selected by Genetic Algorithm and then applied to k-nearest neighbors classification algorithm. We compute the classifier performances by the 10-fold cross-validation method. The proposed approach results in 92% sensitivity, 88% specificity and 90% accuracy in the 2.5–7.5 min time interval priors to PAF event. The proposed method results in better classification performance than the similar studies in literature. Comparing the existing studies, we propose that our approach provide better tool to predict PAF events. © 2018 Elsevier B.V Daha fazlası Daha az

Solid phase microextraction method using a novel polystyrene oleic acid imidazole polymer in micropipette tip of syringe system for speciation and determination of antimony in environmental and food samples

Panhwar, Abdul Haleem | Tüzen, Mustafa | Hazer, Baki | Kazi, Tasneem Gul

Article | 2018 | Talanta184 , pp.115 - 121

A simple, rapid and sensitive solid phase microextraction method was used for the speciation of inorganic antimony (Sb) by using a novel synthesized polymeric material in micropipette tip of syringe system. In present methodology, the specie of Sb (III) made hydrophobic complex with diethyl dithiocarbamate (DDTC) at pH 5.5 and subsequently adsorbed on polystyrene oleic acid imidazole polymer (POIP), whereas Sb(V) did not made complex and adsorbed on the polymer, remained in aqueous solutions. The strategy of multivariate was carried out to screen out the different variables and assessed the optimum values of their experimental value . . .s for the extraction efficiency of analyte. Then the analyte was sorbed on the polymer in micropipette tip of syringe system was quantitatively eluted by different types of acids at different levels for 2–6 aspirating/dispensing cycles. The extracted Sb(III) ions with modifiers were directed into the graphite furnace atomic absorption spectrometry for analysis. The limit of detection (LOD), limit of quantification (LOQ) and preconcentration factor (PF) for Sb(III) was found to be 6 ng L-1, 20 ng L-1 and 100. The RSD value was found to be 4.2%. The standard addition method and certified reference materials were checked for accuracy and validity of method. The developed method was effectively applied for the determination of total and inorganic species of Sb(III) and Sb(V) in different types of water samples, whereas only total Sb was determined in acid digested soil, Tuna fish, rice, spinach, black tea, mixed fruit juice and ice tea samples. © 2018 Elsevier B.V Daha fazlası Daha az

Comment on “Miocene to Quaternary tectonostratigraphic evolution of the middle section of the Burdur-Fethiye Shear Zone, south-western Turkey: Implications for the wide inter-plate shear zones. Tectonophysics 690, 336–354”

Alçiçek, M. Cihat | van den Hoek Ostende L.W. | Saraç, Gerçek | Tesakov, Alison S. | Murray A.M. | Hakyemez, H.Yavuz | Göktaş, Fikret

Editorial | 2018 | Tectonophysics722 , pp.595 - 600

[No abstract available]

Galectin-3: A Novel Biomarker Predicts Sudden Cardiac Death in Hypertrophic Cardiomyopathy

Emet S. | Dadashov M. | Sonsoz M.R. | Cakir M.O. | Yilmaz M. | Elitok A. | Bilge A.K.

Article | 2018 | American Journal of the Medical Sciences356 ( 6 ) , pp.537 - 543

Background: Hypertrophic cardiomyopathy is a primary cardiac disease characterized by left ventricular hypertrophy, myocyte hypertrophy and irregularities and interstitial fibrosis in the absence of any cardiac or systemic diseases and may lead to sudden cardiac death (SCD). Galectin-3 is a ß-galactoside-binding lectin that has been associated with cardiac fibrosis and inflammation. In this study, we aimed to investigate the relationship between serum galectin-3 levels and the criteria for 5-year sudden death risk, recently defined in the European Society of Cardiology guidelines (2014), in patients with hypertrophic cardiomyopathy. . . . Materials and Methods: A total of 52 hypertrophic cardiomyopathy patients were enrolled in the study. Patients were questioned for sudden death risk predictors as outlined in the 2014 European Society of Cardiology guideline. A standardized clinical evaluation was carried out on the basis of previously described prognostic variables to calculate the 5-year risk of SCD. Blood samples were taken from all patients to measure serum galectin-3 levels. A statistical significance level of P < 0.05 was accepted in all tests. Results: We found that there was a significant correlation between the estimated 5-year risk of SCD and serum levels of galectin-3. Conclusions: Galectin-3 may be an inexpensive and easily accessible parameter to predict arrhythmia risk. In addition, it can be used to determine antiarrhythmic prophylaxis as a predictor of an arrhythmia storm in implantable cardioverter defibrillator-implanted patients who are not available for magnetic resonance imaging. © 2018 Southern Society for Clinical Investigatio Daha fazlası Daha az

IL28B, IL29 and micro-RNA 548 in subacute sclerosing panencephalitis as a rare disease

Cakmak Genc G. | Dursun A. | Karakas Celik S. | Calik M. | Kokturk F. | Piskin I.E.

Article | 2018 | Gene678 , pp.73 - 78

Subacute sclerosing panencephalitis (SSPE) is a progressive neurodegenerative disease which affects children and young adults, caused by a persistent infection of defective measles virus. IFN-?s (IL-28A, IL-28B and IL-29) are a group of cytokines mediating antiviral responses. It has been shown that IL-29 levels are significantly higher in infected cells with defective measles virus. IL-29 expression is thought to be regulated at post-transcriptional level and miRNA-548 family targets the 3'UTR of the IFNL1 gene. Impaired immune system has an important role as well as viral factors in SSPE. The aim of our study investigates whether . . .IL-28B, IL-29 levels and gene polymorphisms contribute to the damaged immune response leading to the development of SSPE. Also possible association of miR-548 family with IL-29 and SSPE is explored. Frequencies of rs12979860, rs8099917, rs30461, serum levels of IL-28B, IL-29 and expression levels of miR-548b, miR-548c, miR-548i are determined at 64 SSPE patients and 68 healthy controls. Serum IL-29 levels are statistically significant higher in SSPE patients. Allele frequencies of rs8099917 are statistically significant higher in SSPE patients and resulted G allele is found to increase 2.183-fold risk of SSPE. The expression levels of miR-548b-5p, miR-548c-5p and miR-548i are found to be statistically significant higher in SSPE patients. Dramatically increased level of IL-29 seen in patient group indicates that the elevated miR-548 expression is compensatory result of the over-activated immune system response. Further studies referred to IL28, IL29 and related miRNA's will be enlightened the pathogenesis of SSPE. © 201 Daha fazlası Daha az

Lipase-based on starch material as a development matrix with magnetite cross-linked enzyme aggregates and its application

Mehde A.A. | Mehdi W.A. | Severgün O. | Çakar S. | Özacar M.

Article | 2018 | International Journal of Biological Macromolecules120 , pp.1533 - 1543

The Fe 3 O 4 magnetic nanoparticles were prepared by precipitating ferrous ion (Fe 2+ ) and ferric ion (Fe 3+ ) in alkaline solution. The Fe 3 O 4 magnetic nanoparticles were modified by tannic acid. After functionalization process, two methods were used to immobilize Lipase on Fe 3 O 4 magnetic nanoparticles. In the first method, novel tannic acid magnetic cross-linked enzyme aggregates of lipase (TA-MNPs-CLEAs) were synthesized by cross-linking of lipase aggregates and starch as co-feeder with Fe 3 O 4 magnetic nanoparticles improved by tannic acid (TA-MNPs). In the second method, the lipase was successfully immobilized on the sur . . .face of TA-MNPs. The properties of Fe 3 O 4 and its modified forms were examined by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), scanning electron microscopy (SEM) and zeta potential measurements. Novel TA-MNPs-lipase and TA-MNPs-CLEAs-starch-lipase were enhanced and provided an effective method to improve the activity and stability of lipase for biodiesel production. Using 1% TA-MNPs-lipase and TA-MNPs-CLEAs-starch (w/w of oil) conversions around 67.87, and 85.88%, respectively, were obtained at 40 °C after 2 h of reaction. Furthermore, the immobilized enzyme was easily recovered from the reaction mixture and reused. The obtained results suggest that TA-MNPs-lipase and TA-MNPs-CLEAs-starch-lipase can become a powerful biocatalyst for biodiesel production. © 2018 Elsevier B.V Daha fazlası Daha az

Does Type 2 Diabetes Mellitus Affect the Healing of Bell's Palsy in Adults?

Şevik Eliçora S. | Erdem D.

Article | 2018 | Canadian Journal of Diabetes42 ( 4 ) , pp.433 - 436

Objectives: Bell's palsy (BP) is defined as an acute facial weakness of unknown cause. Many factors affecting the healing of BP have been identified; 1 factor commonly considered relevant is the presence of type 2 diabetes mellitus. Our aim was to investigate the effects of diabetes on the healing of BP. Methods: Sixty patients with BP were followed up for 1 to 3 years and were divided into 2 groups, those with and those without type 2 diabetes. All were prescribed prednisone (initially 1 mg/kg per day, with a tapered dose reduction) and acyclovir (200 mg orally every 4 h, 5 times daily, for 5 days). Their recovery times were compar . . .ed. Results: The healing times of the patients with and without diabetes did not differ. Conclusions: Diabetes does not affect the severity, recovery rate from or healing of BP. © 2017 Diabetes CanadaObjectifs: La paralysie de Bell (PB) se caractérise par une faiblesse faciale soudaine dont la cause est inconnue. Parmi les nombreux facteurs qui nuisent à la guérison de la PB, le facteur généralement jugé pertinent est la présence du diabète sucré de type 2. Notre objectif était d'examiner les répercussions du diabète sur la guérison de la PB. Méthodes: Nous avons suivi 60 patients atteints de PB durant 1 à 3 ans et les avons répartis en 2 groupes : les patients atteints du diabète de type 2 et les patients non atteints. Tous se sont fait prescrire de la prednisone (ordonnance initiale de 1 mg/kg par jour, suivie d'une réduction progressive de la dose) et de l'acyclovir (200 mg par voie orale toutes les 4 heures, 5 fois par jour, durant 5 jours). Nous avons comparé leur vitesse de guérison. Résultats: La vitesse de guérison des patients diabétiques ou non diabétiques ne différait pas. Conclusions: Le diabète n'a pas de répercussions sur la gravité le taux de rétablissement ou la guérison de la PB Daha fazlası Daha az

Adsorption and interactions of the bovine serum albumin-double walled carbon nanotube system

Kopac T. | Bozgeyik K. | Flahaut E.

Article | 2018 | Journal of Molecular Liquids252 , pp.1 - 8

Adsorption and interactions of Bovine Serum Albumin (BSA) with Double Walled Carbon Nanotubes (DWNT) prepared by catalytic chemical vapor deposition (CCVD) synthesis were studied. Adsorption kinetics and equilibrium were investigated by means of in situ UV-spectroscopy. The extent of adsorption at different temperatures was determined at the end of a 420-min adsorption period. The adsorption equilibrium experiments were performed using various amounts of nanotubes at pH 4 and 40 °C, and the adsorption parameters were evaluated comparing the experimental data with models such as the Freundlich and Langmuir isotherms. The maximum prot . . .ein adsorption capacity (Q0) of DWNT was determined as 1221 mg·g- 1. The effect of temperature on the adsorption rate experiments was investigated for constant amount of adsorbent at pH 4. Adsorption kinetics followed the pseudo-first-order rate. Zeta potential measurements were performed with respect to solution pH for understanding the protein-surface interactions. The interactions between positively charged BSA molecules with negatively charged DWNT at pH 4 were found to be electrostatic attractions. Thermodynamic parameters, ?H0 and ?S0 were found as 9.40 kJ·mol- 1 and 321.5 J·mol- 1 K- 1, respectively. ?H0 value indicated that BSA adsorption on DWNT was a physisorption process. © 2017 Elsevier B.V Daha fazlası Daha az

Conformational and vibrational studies of arachidonic acid, light and temperature effects on ATR-FTIR spectra

Gocen T. | Bayari S.H. | Guven M.H.

Article | 2018 | Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy203 , pp.263 - 272

Arachidonic acid (AA) (cis,cis,cis,cis-5,8,11,14-Eicosatetraenoic acid) is an omega-6 polyunsaturated fatty acid (PUFA) constituent of the phospholipids of cell membranes. The conformational behavior of AA in the gas phase was investigated by means of density functional theory (DFT) using B3LYP method with 6-311++G(d,p) basis set. Theoretical calculations on the structures and infrared spectra of monomer conformers and dimer form of the most stable monomer conformer of AA were performed. Vibrational assignment of the fundamental modes was made based on calculated potential energy distribution (PED). Attenuated Total Reflectance Four . . .ier Transform Infrared (ATR-FTIR) spectrum of AA in liquid phase was recorded in the region 4000–450 cm-1. The theoretical spectrum of dimer AA in gas phase is in reasonably good agreement with the experimental liquid phase spectrum. The double bonds in unsaturated fatty acids are prone to oxidation. Oxidized PUFAs lead to adverse health effects. The effects of daylight and temperature on the oxidative stability of AA were investigated using ATR-FTIR spectroscopy. The analysis reveals that the light and thermal treatment induce cis-trans isomerization in AA. © 2018 Elsevier B.V Daha fazlası Daha az

Structural insights of RmXyn10A – A prebiotic-producing GH10 xylanase with a non-conserved aglycone binding region

Aronsson A. | Güler F. | Petoukhov M.V. | Crennell S.J. | Svergun D.I. | Linares-Pastén J.A. | Nordberg Karlsson E.

Article | 2018 | Biochimica et Biophysica Acta - Proteins and Proteomics1866 ( 2 ) , pp.292 - 306

Hydrolysis of arabinoxylan (AX) by glycoside hydrolase family 10 (GH10) xylanases produces xylo- and arabinoxylo-oligosaccharides ((A)XOS) which have shown prebiotic effects. The thermostable GH10 xylanase RmXyn10A has shown great potential to produce (A)XOS. In this study, the structure of RmXyn10A was investigated, the catalytic module by homology modelling and site-directed mutagenesis and the arrangement of its five domains by small-angle X-ray scattering (SAXS). Substrate specificity was explored in silico by manual docking and molecular dynamic simulations. It has been shown in the literature that the glycone subsites of GH10 . . .xylanases are well conserved and our results suggest that RmXyn10A is no exception. The aglycone subsites are less investigated, and the modelled structure of RmXyn10A suggests that loop ß6?6 in the aglycone part of the active site contains a non-conserved ?-helix, which blocks the otherwise conserved space of subsite +2. This structural feature has only been observed for one other GH10 xylanase. In RmXyn10A, docking revealed two alternative binding regions, one on either side of the ?-helix. However, only one was able to accommodate arabinose-substitutions and the mutation study suggests that the same region is responsible for binding XOS. Several non-conserved structural features are most likely to be responsible for providing affinity for arabinose-substitutions in subsites +1 and +2. The SAXS rigid model of the modular arrangement of RmXyn10A displays the catalytic module close to the cell-anchoring domain while the carbohydrate binding modules are further away, likely explaining the observed lack of contribution of the CBMs to activity. © 2017 The Author Daha fazlası Daha az

Bituminous coal seams from underground mines in the Zonguldak Basin (NW Turkey): Insights from mineralogy, coal petrography, Rock-Eval pyrolysis, and meso-and microporosity

Karayiğit A.İ. | Mastalerz M. | Oskay R.G. | Buzkan İ.

Article | 2018 | International Journal of Coal Geology199 , pp.91 - 112

The Zonguldak Basin contains the main bituminous coal reserves of Turkey (ca 1.4 Gt), and several coal seams are mined in underground coal mines within the basin. This study focuses on coal petrography, mineralogy, Rock-Eval pyrolysis, and the meso-and microporosity characteristics of the coal samples collected from several Late Carboniferous (Pennsylvanian) bituminous coal seams in the basin. Forty channel samples were collected from various coal seams in underground mines at the Armutçuk, Zonguldak, and Amasra coalfields in the Zonguldak Basin. The studied coal samples have low total moisture contents (avg. 2.3%, on as-received ba . . .sis), low total S contents (avg. 0.5%, on dry basis), and relatively high ash yields (avg. 21.2%, on dry basis). The random vitrinite reflectance values (0.69–1.21%) and gross calorific values (avg. 33.0 MJ/kg, on dry, ash-free basis) indicate that the coal samples are of high-volatile C bituminous to medium-volatile bituminous coal. Minerals identified by XRD in bulk coal samples are clay minerals (mainly kaolinite and rarely illite and chlorite), quartz, and carbonates (calcite, dolomite, and siderite). In a few samples, pyrite and feldspar were also identified. The SEM-EDX analyses performed on the carbon-coated polished blocks imply that the carbonate minerals are mainly epigenetic, whereas the silicate minerals are generally syngenetic in origin. The results of low-pressure N2 adsorption analysis indicate that the BET surface areas (1.1–5.5 m2/g) and mesopore volumes (0.003–0.011 cm3/g) vary within a wide range. The results of the low-pressure CO2 adsorption analyses show that micropores are abundant in the coal samples; however, the BET surface areas (10.41–78.11 m2/g) and micropore volumes (0.010–0.049 cm3/g) vary widely among the three coal mines and different coal seams. Our results suggest that variations in the mesopore characteristics are mainly controlled by mineral matter, while microporosity is controlled by a combination of organic matter (maceral compositions) and coal rank of the studied coal seams. © 2018 Elsevier B.V Daha fazlası Daha az

Structural and mechanical properties of hypereutectic AlSiFe powders and a new method for determination of sintering temperature

Ergen S. | Yılmaz F. | Gul S. | Kolemen U. | Kilicaslan M.F. | Uzun O.

Article | 2018 | Advanced Powder Technology29 ( 3 ) , pp.563 - 572

In this study, the effect of Si amount on the microstructure, crystal structure and some mechanical properties of Al-(20,25,30 wt%)Si–5Fe powder mixtures produced by high energy ball milling method was investigated by determining the sintering temperature. In the X-ray diffraction analysis, no inter-metallic phases were found except for the Al, Si and Fe phases of the powder mixtures. The X-ray diffraction patterns were analyzed by the Rietveld method to determine amounts of the Al, Si and Fe elements in the powder mixtures. From the scanning electron microscopy analysis, it is seen that as the amount of Si increases, there is a mar . . .ked decrease in the grain size of powders. In the micro-indentation tests performed at room temperature, the hardness and elastic modulus values of the pelletized powders were found to increase with the amount of Si. It was also found that the Al-20Si-5Fe powder mixture with the lowest Si content had the highest damping capability. The high temperature micro-indentation tests showed that the resulting Al-(20,25,30 wt%) Si-5 Fe powder mixtures started to consolidation at 200 °C and completed the consolidation at 400 °C. This method can be used as an alternative method in the determination of the sintering temperature of materials. © 201 Daha fazlası Daha az

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