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Search Results: 1 - 10 of 15145 matches for " Andrea Sz. Kishne "
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Vibration-Induced Conductivity Fluctuation (VICOF) Testing of Soils
Laszlo B. Kish,Cristine L. S. Morgan,Andrea Sz. Kishne
Physics , 2005, DOI: 10.1142/S0219477506003501
Abstract: In this Letter, we propose and experimentally demonstrate a simple method to provide additional in-formation by conductivity measurements of soils. The AC electrical conductance of the soil is measured while it is exposed to a periodic vibration. The vibration-induced density fluctuation implies a corresponding conductivity fluctuation that can be seen as combination frequency components, the sum and the difference of the mean AC frequency and the double of vibration frequency, in the current response. The method is demonstrated by measurements on clayey and sandy soils.
Vibration-Induced Conductivity Fluctuation Measurement for Soil Bulk Density Analysis
Andrea Sz. Kishne,Cristine L. S. Morgan,Hung-Chih Chang,Laszlo B. Kish
Physics , 2007, DOI: 10.1117/12.724667
Abstract: Soil bulk density affects water storage, water and nutrient movement, and plant root activity in the soil profile. Its measurement is difficult in field conditions. Vibration-induced conductivity fluctuation was investigated to quantify soil bulk density with possible field applications in the future. The AC electrical conductivity of soil was measured using a pair of blade-like electrodes while exposing the soil to periodic vibration. The blades were positioned longitudinally and transversally to the direction of the induced vibration to enable the calculation of a normalized index. The normalized index was expected to provide data independent from the vibration strength and to reduce the effect of soil salinity and water content. The experiment was conducted on natural and salinized fine sand at two moisture conditions and four bulk densities. The blade-shaped electrodes improved electrode-soil contact compared to cylindrical electrodes, and thereby, reduced measurement noise. Simulations on a simplified resistor lattice indicate that the transversal effect increases as soil bulk density decreases. Measurement of dry sand showed a negative correlation between the normalized conductivity fluctuation and soil bulk density for both longitudinal and transversal settings. The decrease in the transversal signal was smaller than expected. The wet natural and salinized soils performed very similarly as hypothesized, but their normalized VICOF response was not significant to bulk density changes.
Theory and Techniques for Vibration-Induced Conductivity Fluctuation testing of Soils
Hung-Chih Chang,Laszlo B. Kish,Andrea Kishne,Cristine Morgan,Chiman Kwan
Physics , 2009, DOI: 10.1142/S021947750800443X
Abstract: First we present and theoretically analyze the phenomenological physical picture behind Vibration-Induced Conductivity Fluctuations. We identify the relevant tensors characterizing the electromechanical response against the vibrations for both longitudinal and transversal responses. We analyze the conductivity response with acceleration type vibrations and a new scheme, measurements with more advantageous compression type vibrations that are first introduced here. Compression vibrations provide sideband spectral lines shifted by the frequency of the vibration instead of its second harmonics; moreover the application of this method is less problematic with loose electrodes. Concerning geometry and electrodes, the large measurement errors in earlier experiment indicated electrode effects which justify using four-electrode type measurements. We propose and analyze new arrangements for the longitudinal and transversal measurements with both compression vibration and acceleration vibration for laboratory and field conditions.
Potentially harmful advantage to athletes: a putative connection between UGT2B17 gene deletion polymorphism and renal disorders with prolonged use of anabolic androgenic steroids
Nawed Deshmukh, Andrea Petróczi, James Barker, Andrea D Székely, Iltaf Hussain, Declan P Naughton
Substance Abuse Treatment, Prevention, and Policy , 2010, DOI: 10.1186/1747-597x-5-7
Abstract: The major deactivation and elimination pathway of AASs is through glucuronide conjugation, chiefly catalyzed by the UGT2B17 enzyme, followed by excretion in urine. Excretion of steroids is affected in individuals with a deletion mutation in the UGT2B17 gene. We hypothesize that UGT2B17 deficient individuals are more vulnerable to developing renal disorders with prolonged use of AAS owing to increases in body mass index and possible direct toxic effects of steroids on the kidneys. Elevated serum levels of biologically active steroids due to inadequate elimination can lead to prolonged muscle build up. An increase in body mass index may cause renal injuries due to sustained elevated glomerular pressure and flow rate.In the absence of controlled clinical trials in humans, observational studies can be carried out. Real time PCR with allelic discrimination should be employed to examine the prevalence of different UGT2B17 genotypes in patients with impaired renal function and AAS abuse. In individuals with the UGT2B17 deletion polymorphism, blood tests, biofluid analyses, urinalysis, and hair analyses following the administration of an anabolic steroid can be used to determine the fate of the substance once in the body.If the hypothesis is upheld, anabolic steroid users with a deletion mutation in the UGT2B17 gene may be exposed to an increased risk of developing renal disorders. In the current detecting - sanctioning anti-doping system, athletes motivated by the potential to evade detection owing to their unique genetic make-up could subject themselves to a serious health consequence. More research on AAS metabolism in the presence of UGT2B17 gene deletion is required. Benefit - harm evaluations in therapeutic use of anabolic steroids should also consider this potential link between UGT2B17 gene deletion polymorphism and renal disorders."The purposes of the World Anti-Doping Code and the World Anti-Doping Program which supports it are: i) to protect the Athletes' fundame
Determination of stanozolol and 3′-hydroxystanozolol in rat hair, urine and serum using liquid chromatography tandem mass spectrometry
Nawed IK Deshmukh, Gergely Zachar, Andrea Petróczi, Andrea D Székely, James Barker, Declan P Naughton
Chemistry Central Journal , 2012, DOI: 10.1186/1752-153x-6-162
Abstract: For method development, spiked drug free rat hair, blood and urine samples were used. The newly developed method was then applied to hair, urine and serum samples from five brown Norway rats after treatment (intraperitoneal) with stanozolol for six consecutive days at 5.0?mg/kg/day. The assay for each matrix was linear within the quantification range with determination coefficient (r2) values above 0.995. The respective assay was capable of detecting 0.125?pg/mg stanozolol and 0.25?pg/mg 3′-hydroxystanozolol with 50?mg hair; 0.063?ng/mL stanozolol and 0.125?ng/mL 3′-hydroxystanozolol with 100 μL of urine or serum. The accuracy, precision and extraction recoveries of the assays were satisfactory for the detection of both compounds in all three matrices. The average concentrations of stanozolol and 3′-hydroxystanozolol, were as follows: hair?=?70.18?±?22.32?pg/mg and 13.01?±?3.43?pg/mg; urine?=?4.34?±?6.54?ng/mL and 9.39?±?7.42?ng/mL; serum?=?7.75?±?3.58?ng/mL and 7.16?±?1.97?ng/mL, respectively.The developed methods are sensitive, specific and reproducible for the determination of stanozolol and 3′-hydroxystanozolol in rat hair, urine and serum. These methods can be used for in vivo studies further investigating stanozolol metabolism, but also could be extended for doping testing. Owing to the complementary nature of these tests, with urine and serum giving information on recent drug use and hair providing retrospective information on habitual use, it is suggested that blood or urine tests could accompany hair analysis and thus avoid false doping results.Laboratory statistics of the World Anti-doping Agency (WADA) show that anabolic-androgenic steroids (AAS) account for around 53.6% (average from 2005 to 2010) of all adverse analytical findings in sports [1-6]. Among these, stanozolol is one of the most frequently identified AAS. Stanozolol is a synthetic derivative of the male sex hormone testosterone. According to ‘The 2013 Prohibition List’ of the WADA code, stano
Experiences about the integrated fruit and grape cultivation target programme in the micro-region of Gy ngy s
Cecília Gonda,Antónia Sz?cs,Andrea Ambrus,Sebestyén Dr Tóth
Agrárinformatika Folyóirat , 2011,
Abstract: The most popular target programme of the agricultural-environmental programme advertised by the New Hungary Rural Development Programme in the period between 2010-2014 was the integrated fruit and grape cultivation target programme in the micro-region of Gy ngy s. In the course of our research we were curious how the farms were prepared for it (professional knowledge, technology etc.) whether they were able to adapt to the rules and at the same time how it could take effect on the financial positions of the farms.
Analyses of the Large Subunit Histidine-Rich Motif Expose an Alternative Proton Transfer Pathway in [NiFe] Hydrogenases
Emma Sz?ri-Dorogházi, Gergely Maróti, Milán Sz?ri, Andrea Nyilasi, Gábor Rákhely, Kornél L. Kovács
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0034666
Abstract: A highly conserved histidine-rich region with unknown function was recognized in the large subunit of [NiFe] hydrogenases. The HxHxxHxxHxH sequence occurs in most membrane-bound hydrogenases, but only two of these histidines are present in the cytoplasmic ones. Site-directed mutagenesis of the His-rich region of the T. roseopersicina membrane-attached Hyn hydrogenase disclosed that the enzyme activity was significantly affected only by the replacement of the His104 residue. Computational analysis of the hydrogen bond network in the large subunits indicated that the second histidine of this motif might be a component of a proton transfer pathway including Arg487, Asp103, His104 and Glu436. Substitutions of the conserved amino acids of the presumed transfer route impaired the activity of the Hyn hydrogenase. Western hybridization was applied to demonstrate that the cellular level of the mutant hydrogenases was similar to that of the wild type. Mostly based on theoretical modeling, few proton transfer pathways have already been suggested for [NiFe] hydrogenases. Our results propose an alternative route for proton transfer between the [NiFe] active center and the surface of the protein. A novel feature of this model is that this proton pathway is located on the opposite side of the large subunit relative to the position of the small subunit. This is the first study presenting a systematic analysis of an in silico predicted proton translocation pathway in [NiFe] hydrogenases by site-directed mutagenesis.
SZáSZ Tibor
Debreceni M?szaki K?zlemények , 2010,
Abstract: There has been an extensive discussion on sustainable development, which is likely to go on in the future. For this reason our only aim is to offer a summary of sustainable development for those who wish to gain an overview of the topic.
SZáSZ Tibor
Debreceni M?szaki K?zlemények , 2008,
Abstract: This study compares the optimum criteria of the use of the natural resources under different assumptions by the help of mathematical modeling. In case of non-renewable natural resources, we seek to find out how the intertemporal optimum conditions of the use of resources differ from the optimum conditions for producible goods, and whether the price of natural resources reflect their intertemporal scarcity. In case of renewable resources, the study examines the necessary conditions of a sustainable and profit-maximizing use, which is followed by a discussion of the problems associated with free goods, and with the need for a regulation of their utilization.
Pantoprazole before Endoscopy in Patients with Gastroduodenal Ulcer Bleeding: Does the duration of Infusion and Ulcer Location Influence the Effects?
Istvan Rácz,Milan Szalai,Nora Dancs,Tibor Kárász,Andrea Szabó,Mihaly Cs?ndes,Zoltan Horváth
Gastroenterology Research and Practice , 2012, DOI: 10.1155/2012/561207
Abstract: The aim of this study was to investigate the effect of preemptive pantoprazole infusion on early endoscopic findings in patients with acute ulcer bleeding. Records of 333 patients admitted with acute ulcer bleeding were analyzed. Ulcer bleeders were given either 80?mg bolus of pantoprazole followed by continuous infusion of 8?mg per hour or saline infusion until endoscopy. In 93 patients saline infusion whereas in 240 patients bolus plus infusion of pantoprazole was administrated with mean (±SD) durations of hours and hours, respectively ( ). Actively bleeding ulcers were detected in 46/240 (19.2%) of cases in the pantoprazole group as compared with 23/93 (24.7%) in the saline infusion group ( ). Different durations of pantoprazole infusion (0–4 hours, 4 hours, and 6 hours) had no significant effect on endoscopic and clinical outcome parameters in duodenal ulcer bleeders. Gastric ulcer bleeders on pantoprazole infusion longer than 4 and 6 hours before endoscopy had actively bleeding ulcers in 4.3% and 5% compared to the 19.5% active bleeding rate in the saline group ( and ). Preemptive infusion of high-dose pantoprazole longer than 4 hours before endoscopy decreased the ratio of active bleeding only in gastric but not in duodenal ulcer patients. 1. Introduction In patients with bleeding peptic ulcers infusion of high-dose proton pump inhibitor (PPI) after endoscopic hemostasis reduces recurrent bleeding and improves clinical outcomes [1–6]. High-dose proton pump inhibitors administered intravenously increase and maintain gastric pH above 6, which is thought to be beneficial for platelet aggregation and clot formation over bleeding vessels [7–9]. Recent studies have shown that not only postendoscopic but also preendoscopic high-dose proton pump inhibitor therapy significantly reduces the proportion of patients with high-risk stigmata of recent hemorrhage (active bleeding, nonbleeding visible vessel, and adherent clot) at early endoscopy and decreases the need for endoscopic intervention [10, 11]. However, almost no data exist about the minimally required duration of PPI infusion before endoscopy, whose results downstage the endoscopic lesions and decrease the need for endoscopic intervention [12]. We hypothesized that patients undergoing endoscopy almost immediately after PPI administration may likely utilize only few benefits whereas longer duration of preendoscopic PPI infusion more likely generates clinical benefits. The aim of our retrospective case control study was to investigate the effects of preemptive infusion of pantoprazole before endoscopy
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