bluuebunny/crossref_metadata_2025 huggingface dataset:
Imported case of human tungiasis in Hungary
Authors: Kucsera István , Vincze Ildikó , Danka József , Szénási Zsuzsanna
Published: October 2007

A tungiasis a homoki bolhának –
Tunga penetrans
(Linnaeus, 1758) – a gazda bőrébe behatoló nősténye által okozott bőrbetegség.
Esetismertetés
: 39 éves férfi beteg 2005 májusában jelentkezett vizsgálatra a bal láb I. ujján kialakult elváltozás miatt a Szent Rókus Kórház Bőr- és Nemibeteg Gondozójában (Budapest). A lábon jelentkező elváltozás keletkezésekor Brazíliában, a tengerparton tartózkodott, ahol gyakran sétált mezítláb a homokban. Ott-tartózkodása 6–7. napján, a bal láb I. ujján, kb. 6–7 mm átmérőjű, szélén vizenyős, középen barna pontozottságot mutató elváltozást észlelt. Vizsgálatkor a bal láb I. ujjának mediális felszínén 6 mm átmérőjű, kiemelkedő, klinikailag pustulának tűnő elváltozás volt látható, kb. 2 mm-es hyperaemiás szegéllyel. Az elváltozás megnyitásakor határozott nyomásra kb. 4 mm átmérőjű fehéres színű, nem feszes falú tok buggyant elő. A féreggyanús képletet az Országos Epidemiológiai Központ Parazitológiai Osztályán (Budapest)
Tunga penetrans
ként azonosították.
Következtetés:
Esetismertetésünkkel a hazai szakemberek figyelmét kívánjuk felhívni erre a Magyarországra is behurcolható egzotikus betegségre. Tudomásunk szerint ez Magyarországon az első diagnosztizált behurcolt humán tungiasis eset.
The therapeutical efficiency of the newest extracorporal elimination procedure (Prometheus® treatment) in acute liver failure caused by intoxication
Authors: Bakos Ágnes , Rikker Csaba , Tóvárosi Szilveszter , Kárteszi †Mihály
Published: October 2007

Az akut májelégtelenség mortalitása az intenzív terápia ellenére májtranszplantáció nélkül 60–90%. Az átültethető szervek korlátozott száma miatt azonban a betegek jelentős része a várólistán exitál. A mortalitás csökkentése érdekében számos próbálkozás történt a májelégtelenségben felhalmozódó albuminhoz kötött és vízoldékony méreganyagok eltávolítására, elősegítve ezzel a máj spontán regenerációját, illetve a beteg életben tartását a májtranszplantációig. A Prometheus®-kezelés egy viszonylag új technika, a frakcionált plazmaszeparáció és -adszorpció (FPSA) és egy high-flux dialízis kombinációja. Az eljárás során a beteg saját, szeparált, albuminban gazdag plazmája speciális adszorbereken halad keresztül, lehetővé téve az albuminhoz kötött toxinok eliminációját, miközben a vízoldékony toxinok eltávolítása hemodialízissel történik.
Célkitűzés:
A szerzők szándéka az volt, hogy a Prometheus®-kezelés hatékonyságát igazolják mérgezés okozta akut májelégtelenségben.
Betegek és módszer:
A Prometheus®-kezelést három, konzervatív kezeléssel nem uralható akut májelégtelenségben szenvedő, súlyos, paracetamol-, káliumpermanganát- és Amanita phalloides-mérgezett beteg esetében alkalmazták.
Eredmények:
A három nőbetegnél 10 kezelés történt. Súlyos szövődményt nem észleltek. A kezelések során az albuminhoz kötött (indirekt bilirubin
p
= 0,048; epesav
p
= 0,001) és a vízoldékony (direkt bilirubin
p
= 0,002; kreatinin
p
= 0,007) toxinok szignifikáns csökkenését tapasztalták. Az ammónia, a karbamid, a fibrinogén és az antitrombin III szint szignifikánsan nem változott. Mindhárom beteg májtranszplantáció nélkül meggyógyult.
Következtetés:
A Prometheus®-kezelés hatékonyan távolítja el az akut májelégtelenségben akkumulálódó toxinokat. Biztonságos eljárás. Konzervatív terápiával nem uralható esetekben lehetővé teszi a beteg életben tartását a máj spontán regenerációjáig vagy a májtranszplantációig.
The recurrence of hepatitis C virus after liver transplantation
Authors: Nemes Balázs , Sárváry Enikő , Gerlei Zsuzsa , Fazakas János , Doros Attila , Németh Andrea , Görög Dénes , Fehérvári Imre , Máthé Zoltán , Gálffy Zsuzsa , Pár Alajos , Schuller János , Telegdy László , Fehér János , Lotz Gábor , Schaff Zsuzsa , Nagy Péter , Járay Jenő , Lengyel Gabriella
Published: October 2007

A hazai májátültetési programban magas a hepatitis C-vírus (HCV) okozta végstádiumú májbetegség miatt végzett májátültetések aránya.
Célkitűzés:
A szerzők dolgozatukban elemzik a C-hepatitis miatt májátültetésen átesett betegek adatait.
Módszer:
Az 1995 óta végzett 295 primer májátültetés adatainak retrospektív elemzése: donor- és recipiens-, valamint perioperatív és túlélési adatok, szérumvírus-RNS-titer, percutan májbiopsziák szövettani eredményei.
Eredmények:
A műtét 111 betegnél történt HCV-fertőzés miatt, ez az elvégzett májátültetések 37,6%-a. A vizsgált 111 beteg közül 22 beteg (20%) a posztoperatív időszakban, a vírus kiújulásának észlelése előtt, egyéb okból meghalt. A 89 beteg közül 16 esetben (18%) a vírus visszatérését még nem észlelték, 73 betegnél (82%) azonban a vírus kiújulása szövettanilag igazolható volt. Negyven betegnél (56%) a C-vírus okozta hepatitis kiújulását egy éven belül észlelték, közülük 28 esetben (39%) 6 hónapon belül, 12 esetben hat hónapon túl, de 1 éven belül (17%), és 32 betegnél (44%) egy éven túl. A végstádiumú C-cirrhosis miatt májátültetett betegek kumulatív 1, 3, 5 és 10 éves túlélése 73%, 67%, 56% és 49% volt. A HCV-negatív, májátültetett betegeknél ezek az értékek 80%, 74%, 70% és 70%, a különbség szignifikáns. A májgraft kumulatív túlélése HCV-pozitív betegeknél 72%, 66%, 56% és 49% volt, míg HCV-negatív betegeknél 76%, 72%, 68% és 68%, itt nem szignifikáns a különbség. Korai kiújulás esetén szignifikánsan magasabb szérumvírus-RNS-titert mértek az első 6 hónapban májátültetés után. A májátültetés után 6 hónappal vett protokollbiopszia korai kiújulás esetén magasabb Knodell-pontszámot eredményezett, mint késői kiújuláskor. A fibrosisindex esetében ez fordítva volt. A májátültetéstől az első antivirális kezelésig eltelt idő 1995–2002 között átlagosan 20 hónap volt, 2003 óta 8 hónap.
Következtetések:
Az idősebb donorokból származó, marginális májgraftok magasabb vértranszfúzió-igény mellett történő beültetése előrevetíti a hamarabb bekövetkező vírusrekurrenciát. Ezt a tendenciát erősíti a posztoperatív akut rejectio és az emiatt adott szteroid boluskezelés. A kombinált antivirális kezelés protokollja különbözik az általánosan alkalmazottól: az ún. „stopszabály” nem érvényes. Vírusnegatívvá a betegek csak kevesebb mint 10%-a válik, melynek a fenntartott immunszuppresszió az oka. A májátültetés után korán, akár fél éven belül elkezdett antivirális kezelés a beteg- és grafttúlélést pozitívan befolyásolja, és feltehetően csökkenti a HCV-reinfekció miatti retranszplantációk számát. A második májátültetésnél akkor várhatók jó eredmények, ha időben történik, a recipiens még megfelelő fizikai állapota mellett. Ennek megítélésében a MELD-score segít.
Briefing: Structural failures—the importance of learning from experience
Authors: Carpenter John
Published: October 2007

Major structural failures continue to occur worldwide. John Carpenter of the ICE/IStructE/HSE Standing Committee on Structural Safety—which has just published its latest biennial report—says design engineers must continue to share and learn from each other's experiences.
Central Park station—engineering a new leaf for Manchester
Authors: Nicholls Nigel , Jones Steve
Published: October 2007

Central Park Metrolink station canopy is a dramatic tension structure at the gateway to a new urban regeneration business park in Manchester, UK. Resembling a giant leaf suspended from its stem, it serves both as a transport shelter and an architectural landmark. This paper reports on the organic structure's challenging design and construction, which required the use of sophisticated non-linear analysis techniques as well as two separate wind-tunnel investigations to determine wind loads and likely dynamic behaviour. A complex 16-stage construction sequence also had to be developed and analysed to achieve the required level of cable prestress and to ensure nothing was overstressed during erection.
Climate change and civil engineering challenges
Authors: Hunt Julian
Published: October 2007

The greatest challenge facing civil engineers today is how mitigate and adapt to climate change. However, as discussed in this paper, there are still considerable uncertainties about the trends of some critical aspects of climate change and thus doubts about the mechanisms controlling them. In developing future strategies, a major contribution of civil engineers will be through providing practical and financial evidence about projects and systems which work and do not work. Engineers also know about risk, which is intimately related to system design. The paper concludes that the UK engineering profession needs to be more closely involved in developing effective integrated policies, working with scientists, business and government agencies.
Engineering design in the time of Thomas Telford
Authors: Addis Bill
Published: October 2007

Thomas Telford, the Institution of Civil Engineers' first president, was born 250 years ago this year. His career spanned a half-century that saw some of the most remarkable changes in the way European engineers approached the design of buildings, bridges and machines. This paper reviews the development of engineering design, science and education during Telford's era, revealing that Britain was then far behind France, Germany and other European countries. Through the work of Telford and others, Britain's engineers embraced the practical experimental approach that scientists throughout Europe had developed in the eighteenth century to generate new engineering knowledge and understanding. By the early nineteenth century Britain was emerging as a leading engineering nation.
Catenary action in steel-framed buildings
Authors: Byfield M. , Paramasivam S.
Published: October 2007

The current paper is of relevance to engineers engaged in the design of buildings in which severe column damage resulting from malicious actions is a design scenario. The tying force method as used for providing robustness to steel-framed buildings relies upon catenary action to redistribute loads following column damage. Fortunately severe column damage is extremely rare and for this reason it is not well understood if this load redistribution mechanism is reliable. The current paper presents results of an investigation into the tying force method by way of a case study of a steel-framed building in which support to a perimeter column is removed. Results indicate that industry standard beam–column connections possess insufficient ductility to accommodate the large floor displacements that occur during catenary action and the factor of safety against collapse is shown to be less than 0·2.
Shear of prestressed concrete beams with steel fibres
Authors: Thomas J. , Ramaswamy A.
Published: October 2007

This study outlines the details of non-linear analysis using the modified compression field theory (MCFT) of 11 shear–critical partially prestressed concrete T-beams having steel fibres over partial or full depth. Prestressed T-beams having a shear span-to-depth ratio of 2·65 and 1·59 that failed in shear have been analysed using Response-2000. Response-2000 is an implementation of MCFT within the framework of sectional analysis originally developed for reinforced concrete beams having no fibres. The modelling of the various effects of fibre in the concrete matrix using Response-2000 has been illustrated in the current study. The MCFT-based model used for the present analysis accounts for the non-linearities, such as effect of addition of fibres in the post-peak regime of the compressive stress–strain response, the post-cracking tensile stiffness and response of concrete. The load sustenance through the bridging action of steel fibres at the crack interface has been accounted for in the model. The reinforcements such as deformed bars, prestressing wires and steel fibres have been modelled discretely. The capability of the model to capture cracking behaviour, loads and deflections in various types of shear failures in prestressed concrete beams has been illustrated.
6-[2-(4-arylpiperazin-1-yl)ethyl]-4-halo-1,3-dihydro-2h-benzimidazole-2-thiones: Synthesis and pharmacological evaluation
Authors: Andric Deana , Tovilovic Gordana , Roglic Goran , Soskic Vukic , Tomic Mirko , Kostic-Rajacic Sladjana
Published: October 2007

Eight new compounds with halogen atom introduced into the benzimidazole- 2-thione dopaminergic pharmacophore of 5-[2-(4-arylpiperazin-1-yl)ethyl]-1,3-dihydro- 2H-benzimidazole-2-thiones with the arylpiperazine part of the molecule being selected according to known structure-affinity requirements, have been synthesized. All the new compounds were evaluated for the in vitro binding affinity at the dopamine (DA) D1 and D2 and serotonin 5-HT1A receptors by the competitive radioassays, performed on synaptosomal membranes prepared from fresh bovine caudate nuclei and hippocampi. All the new compounds were strong competitors for the binding of the radioligands to the D2 and 5-HT1A receptors, with the most active of them having 34 and 170 time higher affinity than non-halogenated congeners in the D2 DA receptor radioassays (compounds 9.1b and 9.2b, respectively). Divergently, these compounds were without significant affinities for the D1 DA receptors. .
Interferences from titanium and zirconium during calcium determination by flame spectrometry
Authors: Stojanovic Dimitrije , Milinovic Jelena , Nikolic-Mandic Snezana
Published: October 2007

Titration methods based on an inhibition effect were used to investigate the interferences from Ti and Zr in the determination of Ca by atomic absorption and flame emission spectrometry using an air-acetylene flame. Changes either in the absorption or emission signal of Ca were continuously registered on a computer display and characteristic titration curves were obtained. The mole ratios between Ti or Zr and Ca at characteristic points on titration curves were used to explain the quantitative changes occurring in the solution being titrated and aspirated into the flame. In order to investigate procedures for eliminating these interferences, a method of atomic absorption inhibition release titration was used. For this purpose, a solution of La, as a releasing agent with a very low Ca concentration, used as an indicator, was continuously titrated with the solution of Ti as inhibitor. A comparative study of the activity of Ba, Sr and La as releasing agents was investigated during titration of Ca with Zr solution. Based on the calculated mole ratios between Zr and Ba, Sr or La, the effectiveness of these agents in eliminating the interferences was determined. Possible reactions occurring during evaporation of the aerosol in the air-acetylene flame are represented by chemical equations. .
Mean heat transfer coefficients during the evaporation of 1,1,1,2-tetrafluoroethane (R-134a) in a plate heat exchanger
Authors: Djordjevic Emila , Kabelac Stephan , Serbanovic Slobodan
Published: October 2007

In this study the transfer coefficient of evaporation heat of the refrigerant 1,1,1,2-tetrafluoroethane (R-134a) in a vertical plate heat exchanger was experimentally investigated. The results are presented as the dependancy of the mean heat transfer coefficient for the whole heat exchanger on the mean vapor quality. The influences of mass flux, heat flux and flow configuration on the heat transfer coefficient were also taken into account and a comparison with previously published experimental data and literature correlations was made. .
Ozone absorption in a mechanically stirred reactor
Authors: Takic Ljiljana , Veljkovic Vlada , Lazic Miodrag , Pejanovic Srdjan
Published: October 2007

Ozone absorption in water was investigated in a mechanically stirred reactor, using both the semi-batch and continuous mode of operation. A model for the precise determination of the volumetric mass transfer coefficient in open tanks without the necessity of the measurement the ozone concentration in the outlet gas was developed. It was found that slow ozone reactions in the liquid phase, including the decomposition of ozone, can be regarded as one pseudo-first order reaction. Under the examined operating conditions, the liquid phase was completely mixed, while mixing in a gas phase can be described as plug flow. The volumetric mass transfer coefficient was found to vary with the square of the impeller speed. .
Crystalline forms of silver iodide II: Determination of phase transformations
Authors: Vukic Marija , Veselinovic Dragan , Markovic Vesna
Published: October 2007

In order to obtain appropriate forms of AgI (?- and ?-), a procedure was developed to synthesize AgI at room temperature (23?C), whereby samples of varying crystallographic purity and of varying crystallographic contents of the different forms were obtained. This paper presents the results of investigations of the influence of the manner of preparation of ?-AgI and ?-AgI samples and the sample heating rate on the phase transformations and their temperatures. During the heating of non-ground, ground and pressed synthesized AgI samples, the phase transformations and the corresponding temperatures for one ?-AgI and four ?-AgI samples with different ?-AgI contents (representing a crystallographic impurity) were identified. The following phase transformations were observed for the non-ground AgI samples: ?-AgI ? ?-AgI at 149.6?C (for the ?-AgI sample) and ?-AgI ? ?-AgI at 148.7?C or 148.2?C for the ?-AgI samples with a minimum content of ?-AgI (less than 7 %), as a crystallographic impurity. The phase transition ?-AgI ? ?-AgI was irreversible because ?-AgI was obtained whenever the samples were heated up to 260?C. Manual sample grinding, as well as pressing at p1 = 650 MPa and p2 = 900 MPa resulted in the ?-AgI ? ?-AgI phase transition in all the investigated cases. .
Properties and efficiency of a Pt/Al2O3 catalyst applied in a solid fuel thermo-accumulating furnace
Authors: Belosevic Srdjan , Mladenovic Rastko , Dakic Dragoljub , Paprika Milijana , Eric Aleksandar , Djurovic Dejan , Komatina Mirko , Grbic Bosko , Radic Nenad
Published: October 2007

A prototype of a solid fuel thermo-accumulating furnace has been developed. In order to achieve a higher combustion efficiency, a Pt/Al2O3 catalyst in the form of 3 ? 0.3 mm spheres was applied, which enabled further combustion of flue gases within the furnace. Experimental investigation of the influence of the catalyst on the conversion of CO has been done for different operation regimes and positions of the catalyst. Paper presents selected results regarding CO emission during wood and coal combustion. Investigations suggest a considerable effect of the catalyst and a strong influence of the catalyst position to CO emission reduction. The microstructure of the catalyst beads, characterized by selective chemisorption of CO, has shown the decrease of the number of Pt sites as a consequence of blockage by coke deposits formed during the combustion of solid fuel. .
Headspace solid phase microextraction in the analysis of pesticide residues: Kinetics and quantification prior to the attainment of partition equilibrium
Authors: Djurovic Rada , Markovic Mirjana , Markovic Dragan
Published: October 2007

A new theoretical approach to the headspace/solid phase microextraction (HS/SPME) process is proposed and tested by the analysis of pesticide residues of water samples. The new approach focuses on mass transfer at the sample/gas phase and gas phase/SPME polymer interfaces. The presented model provides a directly proportional relationship between the amount of analytes sorbed by the SPME fiber and their initial concentrations in the sample. Also, the expression indicates that quantification is possible before partition equilibrium is attained. Experimental data for pesticides belonging to various classes of organic compounds were successfully interpreted by the developed model. Additionally, a linear dependence of the amount of pesticide sorbed on the initial analyte concentration in aqueous solution was obtained for a sampling time shorter than that required to reach sorption equilibrium.
The characteristics of the air pollution of a transition economy city: The example of Belgrade
Authors: Zujic Aleksandra , Radak Bojan , Markovic Dragan
Published: October 2007

The results of sulphur dioxide (SO2), nitrogen dioxide (NO2) and black smoke (BS) levels in the Belgrade metropolitan area, the only pollutants measured at almost all 20 monitoring stations set up in the area, were critically analyzed, the most reliable ones select and the pollution characteristics were defined in these terms. Belgrade was found to have pollution typical for a city in economical transition - still high SO2 and BS levels, with seasonal variation, while moderate NO2 levels. This is discussed in terms of sources, as well as spatial and temporal distribution. .
Voltammetric study of the interaction between oxacillin sodium and cysteine in the presence and absence of Mn(II)ions in neutral buffer solution
Authors: Biçer Ender , Coşkun Emine
Published: October 2007

In this study, the voltammetric behaviour of the interaction of oxacillin sodium (OXA) and OXA-cysteine (RSH) was studied by square-wave voltammetry, cyclic voltammetry in Britton-Robinson (B-R) buffer (pH 7.0). OXA gave two peaks at -0.248 and -1.224 V. For the interaction, the peak of mercurous cysteine thiolate (Hg2(SR)2) was selected. It was found that the peak currents corresponding to Hg2(SR)2 significantly decreased, while the peak potential shifted to more positive potentials upon the addition of OXA. The observed phenomena are due to the interaction of OXA with RSH on the surface of the mercury electrode. When OXA was added to the electrochemical cell along with Mn(II), new peaks at -0.146 and -0.608 V were observed. These peaks were due to the catalytic activity of OXA on the reduction of Mn(II) and could be attributed to the formation of Mn(II) complexes with different metal/ligand ratios. On the other hand, in the presence of RSH, the peak at -0.608 V vanished and a reduction peak was observed at -0.662 V. The catalytic reduction peak potential of Mn(II) at -0.662 V indicated that RSH slightly prevented the catalysis process of OXA due to their mutual interaction. .
Pressure drop during evaporation of 1,1,1,2-tetrafluoroethane (R-134a)in a plate heat exchanger
Authors: Djordjevic Emila , Kabelac Stephan , Serbanovic Slobodan
Published: October 2007

Experimental results for the pressure drop during the evaporation of the refrigerant 1,1,1,2-tetrafluoroethane (R-134a) in a vertical plate heat exchanger are presented in this paper. The influences of mass flux, heat flux and vapor quality on the two-phase pressure drop are specially analyzed and compared with previously published experimental data and literature correlations. All results are given in graphical form as the dependency of the frictional pressure drop on the mean vapor quality. .
The use of image analysis for the study of interfacial bonding in solid composite propellant
Authors: Dostanic Jasmina , Uscumlic Gordana , Volkov-Husovic Tatjana , Jancic-Heinemann Radmila , Mijin Dusan
Published: October 2007

In the framework of this research, the program Image Pro Plus was applied for determining the polymer-oxidizer interactions in HTPB-based composite propellants. In order to improve the interactions, different bonding agents were used, and their efficiency was analyzed. The determination of the quantity, area and radius of non-bonded oxidizer crystals is presented. The position of formed cracks in the specimen and their area have a great influence on the mechanical properties of composite propellant. The preparation of the composite propellant in order to enable the photographing of their structure by means of stereoscopic and metallographic microscopes with the digital camera is also described as well. .
Biochemical changes in cuttings of Robinia pseudoacacia after treatment with naphthenate
Authors: Kevresan Slavko , Kovacevic Branislav , Cirin-Novta Vera , Kuhajda Ksenija , Kandrac Julijan , Pavlovic Ksenija , Grbovic Ljubica
Published: October 2007

Naphthenic acids were isolated from gas oil fractions (distillation interval 168-290?C) of Vojvodina crude oil "Velebit", characterized and their biological activity evaluated by the biochemical changes in cuttings of Robinia pseudoacacia after treatment with naphthenate. The activities of IAA peroxidase, total peroxidases and amylase, as well as the contents of reducing sugars and total proteins, were determined in the basal parts of soft wood cuttings of black locust after treatment with sodium naphthenate or the sodium salt of 1-naphthaleneacetic acid (NAA), concentration 10-7 mol dm-3 for 3 or 6 h. High activities of IAA oxidase and amylase, together with a low activity of peroxidase (which is known as being stimulatory for the initiation and activation of primordia) were obtained after the three-hour treatment with sodium naphthenate. Six-hour treatment had an inhibitory effect on the examined biochemical markers. The effects of three- and six-hour treatments with NAA were between those of the corresponding treatment with naphthenic acids. .
The McClelland approximation and the distribution of π-electron molecular orbital energy levels
Authors: Gutman Ivan
Published: October 2007

The total ?-electron energy E of a conjugated hydrocarbon with n carbon atoms and m carbon-carbon bonds can be approximately calculated by means of the McClelland formula E ? g 2mn, where g is an empirical fitting constant, g ? 0.9. It was claimed that the good quality of the McClelland approximation is a consequence of the fact that the ?-electron molecular orbital energy levels are distributed in a nearly uniform manner. It will now be shown that the McClelland approximation does not depend on the nature of the distribution of energy levels, i.e., that it is compatible with a large variety of such distributions. .
Spectrophotometric study of Co(II), Ni(II), Cu(II), Zn(II), Pd(II) and Hg(II) complexes with isatin-β-thiosemicarbazone
Authors: Konstantinovic Sandra , Radovanovic Blaga , Todorovic Zoran , Ilic Slavica
Published: October 2007

The composition and stability of the complexes of isatin-?-thiosemicarbazone with Co(II), Ni(II), Cu(II), Zn(II), Pd(II) and Hg(II) have been investigated using spectrophotometric method at 30?C and constant ionic strength of 0.1 mol dm-3 (KNO3) in 70 % ethanol. Experimental results indicate the formation of MeL and MeL2 complexes for Ni(II) and Co(II), and MeL for Cu(II), Zn(II), Pd(II) and Hg(II) complexes, whose stability constants, ?n, have been calculated using a computerized iterative method of successive approximation.
The possibility to use home bleach solutions for root canal irrigation
Authors: Karadzic Branislav , Manojlovic Dragica
Published: October 2007

Nowadays, sodium hypochlorite is the irrigant of choice in endodontic therapy because of its characteristics. In the dental practice, the most often used are commercial solutions of different concentrations. The aim of this study was to investigate the possibility of using some home bleach solutions as possible agents for root canal irrigation. Sneznik (Panonija AD Pancevo) and Brekin ( Briskol Chemical Industry Vrsac ) were used as the materials in this study. The presence and concentration of hard metals were detected using atomic absorption spectrophotometry (AAS). The results have shown that the concentration of hard metals in the tested solutions, Sneznik and Berekin, was below maximum allowed concentrations for tap water. Tested solutions could be recommended for root canal irrigation but only after hard metal concentration is checked.
Management and complications of anesthesia for transvenous electrical cardioversion of atrial fibrillation in horses: 62 cases (2002–2006)
Authors: Bellei Maria Helena M. , Kerr Carolyn , McGurrin M. Kimberly J. , Kenney Daniel G. , Physick-Sheard Peter
Published: October 2007

Objective—To describe management of anesthesia for transvenous electrical cardioversion (TVEC) in horses and report perianesthetic complications.

Design—Retrospective case series.

Animals—62 horses with atrial fibrillation and without underlying cardiac disease and 60 horses without atrial fibrillation.

Procedures—Medical records of horses with atrial fibrillation anesthetized for TVEC were reviewed, as were records of horses without atrial fibrillation anesthetized for magnetic resonance imaging (MRI). The TVEC group horses were compared with MRI group horses for incidence of intraoperative bradycardia and use of inotropic drugs. Data obtained included patient signalment, weight, duration of anesthesia, heart rate and arterial blood pressure during anesthesia, anesthetic drugs administered, mode of ventilation, perioperative complications, and quality of recovery.

Results—The TVEC group horses were > 1 year of age and were predominantly Standardbreds. The TVEC group horses underwent a total of 76 anesthetic episodes. For 40 (52.6%) anesthetic episodes, horses received xylazine only for premedication, and for 26 (34.2%) anesthetic episodes, horses received xylazine and butorphanol. Induction of anesthesia consisted of ketamine administration in various combinations with diazepam and guaifenesin for 74 (97.4%) anesthetic episodes and ketamine alone for 2 (2.6%). Bradycardia in horses was encountered during 15 of 76 (19.7%) anesthetic episodes. Minor signs of possible postanesthetic myopathy occurred following 6 (7.9%) anesthetic episodes. No significant difference was found between TVEC and MRI group horses regarding incidence of bradycardia and inotropic drug administration.

Conclusions and Clinical Relevance—Short-duration anesthesia for TVEC of atrial fibrillation in horses without underlying cardiac disease was a safe procedure.
Potential impact of an introduction of foot-and-mouth disease into the California State Fair
Authors: Carpenter Tim E. , Christiansen Lasse E. , Dickey Bradley F. , Thunes Clair , Hullinger Pamela J.
Published: October 2007

Objective—To estimate the potential spread of foot-and-mouth disease (FMD) if infected livestock had been exhibited at the 2005 California State Fair.

Design—Epidemic model.

Animals—Dairy cattle, dairy goats, and pygmy goats exhibited between August 24 and August 28 by 195 exhibitors.

Procedures—2 stochastic models were used to simulate epidemics of FMD that might originate from 1, 3, 5, 7, or 10 index cases at the state fair. Data obtained from state fair exhibitors were used to determine the spatial distribution and types of herds to which livestock visiting the state fair returned.

Results—Mean estimated numbers of latently infected animals on day 5 were 12.3 and 75.9, respectively, when it was assumed that there were 1 and 10 index cases. Regardless of the number of index cases, mean estimated numbers of subclinically infected and clinically infected animals were low throughout the 5-day study period. Mean estimated duration of the resulting epidemic ranged from 111 to 155 days, mean number of infected premises ranged from 33 to 244, and mean probability that at least 1 animal that became infected with FMD would subsequently leave the state ranged from 28% to 96% as the number of index cases increased from 1 to 10, respectively.

Conclusions and Clinical Relevance—Results suggested that following introduction of FMD at the California State Fair, infection would likely go undetected until after animals left the fair and that the subsequent outbreak would spread rapidly.
Finite-Volume Solvers for a Multilayer Saint-Venant System
Authors: Audusse Emmanuel , Bristeau Marie-Odile
Published: October 2007

Finite-Volume Solvers for a Multilayer Saint-Venant System

We consider the numerical investigation of two hyperbolic shallow water models. We focus on the treatment of the hyperbolic part. We first recall some efficient finite volume solvers for the classical Saint-Venant system. Then we study their extensions to a new multilayer Saint-Venant system. Finally, we use a kinetic solver to perform some numerical tests which prove that the 2D multilayer Saint-Venant system is a relevant alternative to 3D hydrostatic Navier-Stokes equations.
Genuinely Multi-Dimensional Non-Dissipative Finite-Volume Schemes for Transport
Authors: Després Bruno , Lagoutière Frédéric
Published: October 2007

Genuinely Multi-Dimensional Non-Dissipative Finite-Volume Schemes for Transport

We develop a new multidimensional finite-volume algorithm for transport equations. This algorithm is both stable and non-dissipative. It is based on a reconstruction of the discrete solution inside each cell at every time step. The proposed reconstruction, which is genuinely multidimensional, allows recovering sharp profiles in both the direction of the transport velocity and the transverse direction. It constitutes an extension of the one-dimensional reconstructions analyzed in (Lagoutière, 2005; Lagoutière, 2006).
Analysis of Patch Substructuring Methods
Authors: Gander Martin , Halpern Laurence , Magoulès Frédéric , Roux François-Xavier
Published: October 2007

Analysis of Patch Substructuring Methods

Patch substructuring methods are non-overlapping domain decomposition methods like classical substructuring methods, but they use information from geometric patches reaching into neighboring subdomains, condensated on the interfaces, to enhance the performance of the method, while keeping it non-overlapping. These methods are very convenient to use in practice, but their convergence properties have not been studied yet. We analyze geometric patch substructuring methods for the special case of one patch per interface. We show that this method is equivalent to an overlapping Schwarz method using Neumann transmission conditions. This equivalence is obtained by first studying a new, algebraic patch method, which is equivalent to the classical Schwarz method with Dirichlet transmission conditions and an overlap corresponding to the size of the patches. Our results motivate a new method, the Robin patch method, which is a linear combination of the algebraic and the geometric one, and can be interpreted as an optimized Schwarz method with Robin transmission conditions. This new method has a significantly faster convergence rate than both the algebraic and the geometric one. We complement our results by numerical experiments.
A Level Set Method in Shape and Topology Optimization for Variational Inequalities
Authors: Fulmański Piotr , Laurain Antoine , Scheid Jean-Francois , Sokołowski Jan
Published: October 2007

A Level Set Method in Shape and Topology Optimization for Variational Inequalities

The level set method is used for shape optimization of the energy functional for the Signorini problem. The boundary variations technique is used in order to derive the shape gradients of the energy functional. The conical differentiability of solutions with respect to the boundary variations is exploited. The topology modifications during the optimization process are identified by means of an asymptotic analysis. The topological derivatives of the energy shape functional are employed for the topology variations in the form of small holes. The derivation of topological derivatives is performed within the framework proposed in (Sokołowski and Żochowski, 2003). Numerical results confirm that the method is efficient and gives better results compared with the classical shape optimization techniques.
Transit Ridership, Auto Gas Prices, and World Events
Authors: Currie Graham , Phung Justin
Published: October 2007

U.S. transit ridership research covers a wide field of traveler response factors but is surprisingly limited concerning the impact of auto gas prices. This situation is unfortunate, because gas prices have driven unprecedented growth in transit demand over the past 2 years. The research literature concerning cross-modal market effects of auto gas prices on transit demand is reviewed, including an outline of modeling work conducted in Australia. An analysis of U.S. national transit demand and auto gas trends is presented: the cross-elasticity of demand (e) is modeled in aggregate and separately for U.S. heavy rail, light rail, and commuter rail, and bus. Results indicate that, in aggregate, U.S. transit demand is at the low to medium end of sensitivity to auto gas prices for countries that have a low mode share. This finding is consistent with the lower cost of gas in the United States compared with other countries. The aggregate e has been measured as 0.12 and indicates that total U.S. transit demand will increase by 1.2% for every 10% increase in gas prices. U.S. light rail is particularly sensitive to gas prices, with e values of 0.27 to 0.38. Bus ridership is only slightly sensitive to gas prices (e = 0.04), and heavy rail is higher (0.17), consistent with most international evidence. A longitudinal model of trends has suggested some acceleration in transit mode sensitivity as world events have continuously affected prices; however, the model suggests that the effects since Hurricane Katrina (August 2005) have softened.
Impact of Rising Fuel Prices on U.S. Transit Ridership
Authors: Haire Ashley R. , Machemehl Randy B.
Published: October 2007

As gasoline prices have risen to unprecedented levels over the past 2 years, many transit agencies have claimed that higher fuel prices have driven ridership growth. It is determined first whether such a correlation is substantiated by the available data and then, if such correlation exists, the nature of this relationship. Five U.S. cities were selected for analysis on the basis of their level of automobile orientation and the extent and variety of transit services: Atlanta, Georgia; Dallas, Texas; Los Angeles, California; San Francisco, California; and Washington, D.C. Most of the transit systems in the five cities analyzed have experienced ridership growth since early 2004. Exceptions include the Atlanta bus and heavy rail systems and the San Francisco bus systems. With the use of time series analysis, seasonal indices, and correlation coefficients, ridership trends are evaluated and compared with corresponding national fuel prices. With the exceptions of the modes cited above and the Virginia Railway Express commuter rail in Washington, D.C., the correlation between ridership and fuel prices is statistically significant for all systems. This finding indicates that fuel price increases have indeed played a role in encouraging transit use in historically automobile-oriented American cities. Finally, the empirical relationships between fuel price and transit demand are explored. Results indicate that, on average, as fuel price increases by 1%, transit demand increases on the order of 0.24%; in other words, ridership increases approximately 0.09% for each $0.01 increase in fuel price.
Maturity of Key Technologies Provides More Options for Transit and Paratransit Planners
Authors: Bruun Eric C.
Published: October 2007

Travel needs and patterns within metropolitan regions are becoming increasingly more complex. Community pressure to use limited operations budgets in the most effective and efficient manner is also increasing, even though these requirements often conflict. Ideally, in response, service planners should be able to explore a wide range of service design options, unencumbered by technological constraints. A service planning concept based on a spectrum of possible service designs ranging from pure fixed route to pure demand responsive, with many intermediate options, is described. Intelligent transportation system technologies and scheduling software have matured to the point that this concept is now realistic. How these technologies enable a highly integrated system in which numerous service designs can be operated simultaneously is explained. Likely benefits are presented from several perspectives: planning latitude given by time of day, by change of season, and for efficient vehicle use and adaptation to changes in service area character over the years. Some requirements for reorganization by typical transit agencies are discussed. Potential benefits from better coordination or the merger with outside agencies are outlined. Vendors have been cautious to date and are unlikely to complete the technological integration needed without firm commitments. Thus, a funded research project at an appropriate volunteer site would be required.
Quantifying Position Accuracy of Multimodal Data from Global Positioning System–Enabled Cell Phones
Authors: Aguilar David P. , Barbeau Sean J. , Labrador Miguel A. , Perez Alfredo J. , Perez Rafael A. , Winters Philip L.
Published: October 2007

The emergence of cell phones with embedded Global Positioning System (GPS) chips provides opportunities to push personalized real-time travel information subject to an individual's current location. One such application, a travel assistant device, notifies cognitively disabled public transportation users when it is time to request a stop and exit the vehicle. GPS-enabled cell phones must provide highly accurate real-time location data for this type of service. The components used in the data-collection process are identified, and a quantitative analysis of real-time GPS data obtained with a cell phone while walking, driving a vehicle, and riding public transportation is provided. The expectation was that position accuracy would suffer when the GPS signal was obstructed by a vehicle or the user's clothing. The obtained data demonstrate the results of location fix attempts over different transportation modes in an urban environment. The highest percentage of GPS fixes (79.0%) was obtained by users walking with the cell phone open and unobstructed; walking also produced valid GPS data (i.e., location data estimated to be accurate within 30 m of the true position) 66.2% of the time. For bus trips, GPS and valid fix percentages were 71.7% and 66.1%, respectively, when the phone was held near the window; when the phone was placed in the traveler's lap, these numbers fell to 51.3% and 27.8%, respectively. Car trips provided higher numbers: 77.7% and 71.6%, respectively. Location-based transportation applications are feasible using current technology, but predictive algorithms may be required to deliver highly accurate and timely location-aware services to cell phone users in highly obstructed environments.
Where Does Carsharing Work?
Authors: Celsor Christine , Millard-Ball Adam
Published: October 2007

A tool to assess the market potential for new carsharing operations in urban communities is examined and applied. The research is based on the analysis conducted for TCRP Report 108: Carsharing: Where and How It Succeeds. Geographic market segments in urban areas are analyzed. A geographic information system (GIS)–based analysis of 13 U.S. regions finds that neighborhood and transportation characteristics are more important indicators for carsharing success than the individual demographics of carsharing members. Results indicate that low vehicle ownership has the strongest, most consistent correlation to the amount of carsharing service in a neighborhood. Thresholds based on analysis results are outlined for low service (i.e., carsharing may be viable but limited growth can be expected) and high service (i.e., carsharing is likely to flourish). This tool to identify neighborhoods that can support carsharing is applied to a community seeking to establish a carsharing program: Austin, Texas. The analysis finds that several Austin neighborhoods have the characteristics to support carsharing (e.g., low vehicle ownership rates and high percentages of one-person households), but few Austin neighborhoods could support a high level of carsharing service.
Accuracy and Precision of the Transit Tracker System
Authors: Crout David T.
Published: October 2007

The accuracy and the precision of Transit Tracker, the Internet- and telephone-based real-time arrival information system of the Tri-County Metropolitan Transportation District of Oregon (TriMet), are analyzed. Although Transit Tracker estimates the arrival times of both bus and rail vehicles, this analysis is limited to bus vehicles. Archived data from TriMet's automatic vehicle location (AVL) and automatic passenger counter systems were used to compare actual bus arrival times with Transit Tracker estimates drawn from logs created in the estimation process. Accuracy was evaluated primarily by calculating the mean of the difference between the actual bus arrival times and the arrival times estimated by Transit Tracker. Precision was determined largely by the degree of variation in the estimates and measured by the standard deviation of the difference between the actual bus arrival times and the arrival times estimated by Transit Tracker. Finally, an arrival estimation error model was developed to test the effects of a series of factors on the degree of estimation error.
Use of Archived Bus Location, Dispatch, and Ridership Data for Transit Analysis
Authors: Golani Hina
Published: October 2007

Some of the novel ways archived computer-aided dispatch (CAD), automatic vehicle location (AVL), and automatic passenger counter (APC) information have been used by the Champaign–Urbana Mass Transit District in Illinois in the past year are described. Geographic information system (GIS) tools were used to visualize and understand schedule deviation and passenger flow information for a bus route experiencing regular delays, and various ridership and operational performance analyses were performed. GIS made it easy to identify the problem blocks (bus assignments) and trips while allowing data visualization regarding spatial location and passenger flow. Another innovative application has used the archived screen messages in the CAD-AVL system to analyze the response times of dispatchers in the control room when an operator has initiated a request to talk to a supervisor. A Visual Basic script was developed to parse the extensive data, calculate response times for all requests, determine whether any requests were not answered at all, and identify vehicles in which attempts to establish contact were unsuccessful. This application helped verify operator complaints regarding delayed or absent responses, monitor dispatcher efficiency, and identify problems with the radio equipment.
Emergency Evacuation Planning and Preparedness of Transit Facilities
Authors: Elmitiny Noor , Ramasamy Shankar , Radwan Essam
Published: October 2007

The growing need for evacuation planning is addressed by using a computer-based model of traffic simulation. The VISSIM traffic simulation tool was used to evaluate a current plan and alternative plans for the deployment of transit during an emergency situation in a transit facility such as a bus depot. Different strategies were simulated to study the effect of evacuation on the surrounding traffic network as well as to help the local transit company (LYNX) evaluate its evacuation plan and consider different possibilities without the risk and cost of actual evacuation drills. Nine evacuation scenarios were simulated and analyzed to reach the best evacuation strategy for the LYNX company's main bus depot. Evacuation strategies evaluated include traffic diversion, bus signal optimization, access restriction, different destinations, and evacuation of pedestrians. Total network delay for each scenario was compared with the base case, and results indicate that pedestrian evacuation was better than using buses. Traffic rerouting also could potentially reduce delays and evacuation clearance time.