bluuebunny/crossref_metadata_2025_split huggingface dataset:
Severity of scleroderma lung disease is related to alveolar concentration of nitric oxide
Authors: Tiev K. P. , Cabane J. , Aubourg F. , Kettaneh A. , Ziani M. , Mouthon L. , Duong-Quy S. , Fajac I. , Guillevin L. , Dinh-Xuan A. T. 
Published: April 2007

The alveolar concentration of exhaled nitric oxide (CA,NO) is increased in patients with systemic sclerosis (SSc), but whether this increase is related to the severity of interstitial lung disease (ILD) in SSc has not yet been investigated.In total, 58 SSc patients prospectively underwent pulmonary function tests (PFTs), echocardiogram and fibrosis scoring on pulmonary computed tomography (CT). Patients were divided into two groups according to the presence (or not) of ILD. Measurements of CA,NOwere assessed in all SSc patients and compared with those obtained in 19 healthy volunteers. Relationships were sought between CA,NOPFTs and CT scan fibrosis scores.Overall, CA,NOwas significantly increased in SSc patients (median (range) 6.2 (3.8–9.9) ppb) as compared with controls (2.0 (1.2–3.0) ppb). Among SSc patients, CA,NOwas significantly higher in patients with ILD compared with patients without ILD (n = 33, 7.5 (5.2–11.9) ppbversusn = 25, 4.9 (3.1–7.0) ppb, respectively). CA,NOwas inversely related to total lung capacity (r =  −0.34) and the diffusing capacity of the lung for carbon monoxide (r =  −0.37) and was directly related to CT scan fibrosis scores (r = 0.36).An increased alveolar concentration of exhaled nitric oxide could, at least in part, either reflect or contribute to the severity of lung disease and could be used to noninvasively assess the extent of interstitial lung disease in systemic sclerosis.
Reduced mitochondrial density in the vastus lateralis muscle of patients with COPD
Authors: Gosker H. R. , Hesselink M. K. C. , Duimel H. , Ward K. A. , Schols A. M. W. J. 
Published: April 2007

Skeletal muscle dysfunction is a well-recognised hallmark of chronic obstructive pulmonary disease (COPD) leading to exercise intolerance. The vastus lateralis of COPD patients is characterised by reduced mitochondrial enzyme activity; however, this is not the case in the tibialis anterior. It is, however, unclear whether the compromised oxidative capacity in the vastus is due to reduced mitochondrial volume density.Muscle biopsies were obtained from the vastus lateralis of six COPD patients and four healthy age-matched controls, and from the tibialis anterior of another six COPD patients and six controls. Mitochondrial number, fractional area and morphometry, as well as Z-line width (as a surrogate marker of fibre type), were analysed using transmission electron microscopy.Mitochondrial number (0.34versus0.63 n·µm−2) and fractional area (1.95versus4.25%) were reduced in the vastus of COPD patients compared with controls. Despite a reduced mitochondrial number (0.65versus0.88 n·µm−2), the mitochondrial fractional area was maintained in the tibialis of COPD patients compared with controls.It can be concluded that the reduced mitochondrial fractional area is likely to contribute to the decreased oxidative capacity in the vastus of chronic obstructive pulmonary disease patients, whereas the maintained mitochondrial fractional area in the tibialis may explain the normal oxidative capacity.
A new paradigm of mechanical energy dissipation. Part 1: Theoretical aspects and practical solutions
Authors: Eroshenko V A 
Published: April 2007

Although fluid viscosity and speed are still most widely used for dissipating mechanical energy, current research and development on conventional dampers is beginning to saturate; creative design initiatives to obtain higher performance with conventional passive dampers are limited. In order to provide new levels of comfort, reliability, and dissipative power of damping, the present author suggests using the repulsive forces acting within interfaces between capillary-porous solids with high specific surface and non-wetting liquids. When placed in working chambers and subjected to periodical compression-expansion processes, such working media demonstrate pronounced hysteresis phenomena in pressure-volume coordinates, which characterize dissipated energy with specific (volumetric) values 10–100 times greater than that of conventional dampers. Furthermore, it is possible to design a damper where the force may depend insignificantly on the speed of rod displacement (the damping coefficient tending to zero) within a wide range of speed values. In this way, there is a new solution to the ‘comfort-road holding’ trade-off; reliable wheel-road adhesion is possible even for zero damping coefficient (perfect comfort). This new paradigm of mechanical energy dissipation substantially improves damper performance qualitatively and quantitatively and extends its scope of application. The search for such a concept, its thermodynamic substantiation, and practical construction are the main objectives of this paper.
An experimental study to assess the potential of homogeneous charge compression ignition diesel combustion with various fuels for light-duty engines
Authors: Wagner U , Wiemer S , Velji A , Spicher U 
Published: April 2007

Single-cylinder engine tests were carried out to assess the potential of homogeneous charge compression ignition (HCCI) diesel combustion compared to the conventional heterogeneous operation mode. For the experiments a single-cylinder engine with a cylinder volume of 0.421 litre was used. Besides the comparison of conventional operation and HCCI operation of the same engine special emphasis was put on the utilization of synthetic fuels such as gas-to-liquid (GtL) or biomass-to-liquid (BtL) fuels. Therefore, in addition to a standard winter diesel, a fuel with mid-sized n-alkanes and mixtures of n-alkanes and aromatic hydrocarbons was used to investigate the influence of different ignitabilities and boiling curves on the combustion. A great advantage of synthetic fuels is the possibility to design them according to the combustion process requirements. In addition, these GtL or BtL fuels will lead to a higher independence from fossil fuels. To assess the potential of HCCI combustion compared to conventional diesel combustion the engine must have the capability to run in both modes. While using the different fuels several engine operation parameters like injection timing and splitting were varied in order to obtain information about their effect on combustion as well as on engine out-emissions. Furthermore, full-load curves for the different fuels were identified to find out where HCCI operation can be applied in an engine map.
Bayesian Estimation of Bid Sequences in Internet Auctions Using a Generalized Record-Breaking Model
Authors: Bradlow Eric T. , Park Young-Hoon 
Published: April 2007

A sequence of bids in Internet auctions can be viewed as record-breaking events in which only those data points that break the current record are observed. We investigate stochastic versions of the classical record-breaking problem for which we apply Bayesian estimation to predict observed bids and bid times in Internet auctions. Our approach to addressing this type of data is through data augmentation in which we assume that participants (bidders) have dynamically changing valuations for the auctioned item, but the latent number of bidders “competing” in those events is unseen. We use data from notebook auctions provided by one of the largest Internet auction sites in Korea. We find significant variation in the number of latent bidders across auctions. Our other primary findings are as follows: (1) the latent bidders are significant in number relative to observed bidders, (2) the latent number of remaining bidders is considerably smaller than that of new entrants to the auction after a given bid, and (3) larger bid and time increments significantly influence the bidding participation behavior of the remaining bidders. As part of our substantive contribution, we highlight the model’s ability to understand brand equity in an Internet auction context through a brand’s ability to simultaneously bring in bidders, higher bid amounts, and faster bidding.
Study of Gas/Condensate Reservoir Exploitation Using Neurosimulation
Authors: Ayala Luis F. , Ertekin Turgay , Adewumi Michael 
Published: April 2007

Summary
Gas/condensate reservoirs have been the subject of intensive research throughout the years because they represent an important class of the world's hydrocarbon reserves. Their exploitation for maximum hydrocarbon recovery involves additional complexities that cast them as a different class of reservoirs, apart from dry-gas, wet-gas, and oil reservoirs. Gas/condensate reservoirs are good candidates for compositional-simulation studies because their depletion performance is highly influenced by changes in fluid composition. Often, highly sophisticated and computationally intensive compositional simulations are needed for the accurate modeling of their performance, phase behavior, and fluid-flow characteristics. The desired outcome of a simulation study for gas/condensate reservoirs is the identification and development of the best operational production schemes that maximize hydrocarbon recovery with a minimum loss of condensate at reservoir conditions. However, compositional simulations are demanding in terms of computational overhead, manpower, and software and hardware requirements. Artificial-neural-network (ANN) technology (soft-computing) has proved instrumental in establishing expert systems capable of learning the existing vaguely understood relationships between the input parameters and output responses of highly sophisticated hard-computing protocols such as compositional simulation of gas/condensate reservoirs. In this study, we conduct parametric studies that identify the most influential reservoir and fluid characteristics in the establishment of optimum production protocols for the exploitation of gas/condensate reservoirs. During the training phase of the ANN, an internal mapping is created that accurately estimates the corresponding output for a range of input parameters. In this paper, a powerful screening and optimization tool for the production of gas/condensate reservoirs is presented. This tool is capable of screening the eligibility of different gas/condensate reservoirs for exploitation as well as assisting in designing the optimized exploitation scheme for a particular reservoir under consideration for development.
The Effect of Wettability and Pore Geometry on Foamed-Gel-Blockage Performance
Authors: Romero-Zerón Laura , Kantzas Apostolos 
Published: April 2007

SummaryExcessive gas and/or water production is a common problem encountered throughout the lifetime of oil-producing wells. High-producing gas/oil or water/oil ratios are normally responsible for both rapid productivity decline and increased operating costs caused by gas or water processing. The result is often a premature shut-in of wells because production has become uneconomical. Foamed gels have been used as selective barriers to counteract disproportionate gas/oil and/or water/oil ratios in oil production. However, research on the effects of critical parameters such as wettability of the porous medium and pore geometry on foamed-gel-blockage performance remains incomplete.In this work, microscale experiments, which involve the magnified observation of flowing and trapped foamed gel in etched-glass micromodels, were performed. The purpose of this research is to provide new insights into the sensitivity of foamed-gel-blockage performance as a function of porous-media wettability (strongly water-wet or strongly oil-wet systems) and pore geometry.The experimental results indicate that foamed gels presented higher blocking efficiency in strongly oil-wet systems than in strongly water-wet systems. Under these experimental conditions, foamed gels exhibited higher blocking efficiency at lower pore-body-/pore-throat-size aspect ratios. The plugging treatment exhibited stability after subsequent steps of gas and brine injection. Ultimately, these results indicate that the combination of foam and gel systems has technical advantages that make foamed gels superior mobility-control and plugging agents.
Study of intragastric administration of doxycycline: pharmacokinetics including body fluid, endometrial and minimum inhibitory concentrations
Authors: Bryant J. E. , Brown M. P. , Gronwall R. R. , Merritt K. A. 
Published: April 2007

SummaryThe objectives of this study were to determine the pharmacokinetics and tissue concentrations of doxycycline after repeated intragastric administration, and to determine the minimum inhibitory concentrations (MIC) for equine pathogenic bacteria. Inexperiment 1, 2 mares received a single intragastric dose of doxycycline hyclate (3 mg/kg bwt). Mean peak serum concentration was 0.22 μg/ml 1 h postadministration. Inexperiment 2, 5 doses of doxycycline hyclate (10 mg/kg bwt), dissolved in water, were administered to each of 6 mares via nasogastric tube at 12 h intervals. The mean ± s.e. peak serum doxycycline concentration was 0.32 ± 0.16 μg/ml 1 h after the first dose and 0.42 ± 0.05 μg/ml 2 h after the fifth dose. The mean trough serum concentrations were ≥ 0.16 μg/ml. Highest mean synovial concentration was 0.46 ± 0.13 μg/ml and highest mean peritoneal concentration was 0.43 ± 0.07 μg/ml, both 2 h after the fifth dose. Highest urine concentration was mean ± s.e. 145 ± 25.4 μg/ml 2 h after the last dose. Highest endometrial concentration was mean ± s.e. 1.30 ± 0.36 μg/ml 3 h after the fifth dose. Doxycycline was not detected in any of the CSF samples. Mean ± s.e. Vdareawas 25.3 ± 5.0 l/kg and mean t1/2was 8.7 ± 1.6 h. Inexperiment 3, minimum inhibitory concentrations of doxycycline were determined for 168 equine bacterial culture specimens. The MIC90was ≤ 1.0 μg/ml forStreptococcus zooepidemicusand 0.25 μg/ml forStaphylococcus aureus.Based on drug concentrations achieved in the serum, synovial and peritoneal fluids and endometrial tissues and MIC values determined in the present study, doxycycline at a dose of 10 mg/kg bwtper osevery 12 h may be appropriate for the treatment of infections caused by susceptible (MIC ≤ 0.25 μg/ml) Gram‐ positive organisms in horses.
Influence of bacitracin on microbial functions in the gastrointestinal tract of horses
Authors: Collinder E. , Berge G. N. , Grønvold B. , Lindholm A. , Midtvedt T. , Norin E. 
Published: April 2007

SummaryThis study investigated the influence of zinc bacitracin on the intestinal flora of horses. The functionally active intestinal flora was examined in 6 horses during treatment with zinc bacitracin. Utilising gas chromatography, spectrophotometry, gel electrophoresis and paper chromatography, samples were analysed on biochemical markers reflecting the action of parts of the intestinal flora. The following 5 flora‐related functions were studied in faecal samples and intestinal samples from different sections of the hindgut: conversion of cholesterol to coprostanol and of bilirubin to urobilinogens, degradation of mucin and of β‐aspartylglycine and inactivation of tryptic activity. Conversion to coprostanol, conversion to urobilinogens and degradation of mucin were affected by treatment of zinc bacitracin and conversion to coprostanol was most sensitive. All functions were normalised in a short time, in contrast to man and rats. Differences in environmental exposures are probably the reason for a more rapid normalisation of the intestinal flora functions in horses.
The forelimb in walking horses: 2. Net joint moments and joint powers
Authors: Clayton H. M. , Hodson E. , Lanovaz J. L. 
Published: April 2007

SummaryThe objective was to measure the net joint moments and joint powers for the joints of the equine forelimb during the walk. Videographic and force data were combined with morphometric information using an inverse dynamics method. During stance phase the predominant joint moment was on the palmar aspect of all forelimb joints except the shoulder, where the peak moment was considerably higher than at any other joint. The entire forelimb showed net energy absorption in both stance and swing phases. The elbow was the only joint that showed net generation of energy, which was used to maintain the limb in extension in early stance as the horse's body vaults over the limb and to drive protraction and retraction of the limb during swing. The carpus aligned the limb into a supportive strut, but did not play an important role in energy absorption or generation. A small burst of positive work on the flexor aspect at the start of breakover indicated that the carpus played an active role in initiating breakover during walking. The fetlock functioned elastically to store and release strain energy during stance. The coffin joint acted as an energy damper during most of stance with a small burst of energy generation on the flexor aspect as the joint flexed during breakover. The magnitude of the peak joint power during swing decreased in a proximal to distal sequence. It is concluded that the elbow joint is the main site of energy generation. The shoulder and coffin joints act as energy dampers during stance. The distal joints had very low joint powers and appeared to be driven by inertial forces during the swing phase. This information will be applied to derscribe how horses compensate for different lamenesses in terms of redistributing the functions of energy generation and absorption between joints.
Effect of water restriction on equine behaviour and physiology
Authors: Houpt K. A. , Eggleston A. , Kunkle K. , Houpt T. R. 
Published: April 2007

SummarySix pregnant mares were used to determine what level of water restriction causes physiological and/or behavioural changes indicative of stress. Nonlegume hay was fedad libitum.During the first week of restriction, 5 l water/100 kg bwt was available, during the second week 4 l/100 kg bwt and, during the third week, 3 l/100 kg bwt.Ad libitumwater intake was 6.9 l/100 kg bwt; at 3 l/100 kg bwt water intake was 42% of this. Daily hay intake fell significantly with increasing water restriction from 12.9 ± 0.75 kg to 8.3 ± 0.54 kg; bodyweight fell significantly for a total loss of 48.5 ± 8.3 kg in 3 weeks.Daily blood samples were analysed; osmolality rose significantly with increasing water restriction from 282 ± 0.7 mosmols/kg to 293.3 ± 0.8 mosmols/kg bwt, but plasma protein and PCV did not change significantly. Cortisol concentrations fell from 8.1 ng/ml to 6.4 ng/ml over the 3 week period. Aldosterone fell from 211.3 ± 74.2 pg/ml to 92.5 ± 27.5 pg/ml at the end of the first week. The behaviour of 4 of the 6 mares was recorded 24 h/day for the duration of the study. The only significant difference was in time spent eating, which decreased with increasing water restriction from 46 ± 3% to 30 ± 3%. It is concluded that water restriction to 4 l/100 kg bwt dehydrates pregnant mares and may diminish their welfare, but is not life‐ or pregnancy‐threatening.
The effects of frusemide on racing times of Standardbred pacers
Authors: Soma L. R. , Birks E. K. , Uboh C. E. , May L. , Teleis D. , Martini J. 
Published: April 2007

SummarySeven hundred and eighty‐eight Standardbred pacers competing in 8378 races at one racetrack were analysed to determine the effects of the administration of prerace frusemide on racing times (RT). Frusemide was administered i.v. 4 h before the race to pacers diagnosed with exercise‐induced pulmonary haemorrhage (EIPH). Of the pacers, starting in the 1997 racing season, 32.5% received prerace frusemide. This study demonstrated that administration of frusemide prior to racing significantly decreased RT. There was an overall significant decrease (P<0.00001) in RT of 0.67 s. The overall RT for horses, geldings, and females, were mean ± s.e 117.91 ± 0.06, 118.20 ± 0.03 and 118.86 ± 0.04, respectively. RT progressively decreased until age 6 and increased thereafter. Horses, geldings and females ran a mean of 0.46, 0.31 and 0.74 s faster, respectively, with prerace administration of frusemide. This decrease in RT following prerace administration was most pronounced in younger pacers. In this study, a greater percentage of older pacers received prerace frusemide; however, the effect of frusemide on RT was decreasing with age.Prerace venous acid‐base screening was performed in 2729 of the pacers competing. Pennsylvania Harness Racing Commission Regulations disqualify Standardbreds from racing with a base excess of over 10 and 12 mmol/l for Standardbreds without and with prerace administration of frusemide. The prerace venous acid‐base levels were not significantly related to RT and, forthose Standardbreds also sampled following the race, there was no correlation between pre‐ and postrace acid‐base status.
A comparison of the haemodynamic effects of isoflurane and halothane anaesthesia in horses
Authors: Raisis A. L. , Young L. E. , Blissitt K. J. , Brearley J. C. , Meire H. B. , Taylor P. M. , Lekeux P. 
Published: April 2007

SummaryThe purpose of this study was to compare the haemodynamic effects of equipotent isoflurane and halothane anaesthesia. Six adult horses were investigated on two separate occasions at least 4 weeks apart. On both occasions anaesthesia was induced by ketamine 2.2 mg/kg bwt given 5 min after i.v. administration 100 μg/kg bwt romifidine. Anaesthesia was maintained either by halothane or isoflurane (end‐tidal concentrations 0.9–1.0% and 1.3–1.4%, respectively). Horses were ventilated by intermittent positive pressure to maintain PaCO2between 40–50 mmHg. Haemodynamic variables were measured using catheter‐mounted strain gauge transducers in the left and right ventricle, aorta, and right atrium. Cardiac output (CO), velocity time integral (VTI), maximal aortic blood flow velocity (Vmax) and acceleration (dv/dtmax), left ventricular pre‐ejection period (PEP) and ejection time (ET) were measured from aortic blood flow velocity waveforms obtained by transoesophageal Doppler echocardiography. Flow velocity waveforms were recorded from the femoral arteries and veins using low pulse repetition frequency Doppler ultrasound. Time‐averaged mean velocity (TAV), velocity of component a (TaVa), velocity of component b (TaVb) and early diastolic deceleration slope (EDDS) were measured. Pulsatility index (PI) and volumetric flow were calculated. Microvascular blood flow was measured in the left and right semimembranosus muscles by laser Doppler flowmetry.Maximal rate of rise of LV pressure (LVdp/dtmax), CO, Vmax, dv/dtmax, ET, VTI were significantly higher at all time points during isoflurane anaesthesia compared to halothane anaesthesia. Pre‐ejection period and diastolic aortic blood pressure were significantly less throughout isoflurane anaesthesia compared to halothane. Isoflurane anaesthesia was associated with significantly lower systemic vascular resistance than halothane anaesthesia. Femoral arterial and venous blood flow were significantly higher and EDDS and PI were significantly lower during isoflurane anaesthesia compared to halothane anaesthesia. In addition during both halothane and isoflurane anaesthesia, femoral arterial flow was higher and EDDS and PI lower in the left (dependent) artery compared to the right (nondependent) artery.This study supports previous work demonstrating improved left ventricular systolic function during isoflurane compared to halothane anaesthesia. This improvement was still evident after premedication with a potent‐long acting α2‐adrenoreceptor agonist, romifidine, and induction of anaesthesia with ketamine. There was also evidence of increased hindlimb blood flow during isoflurane anaesthesia. However, there were differences observed in flow between the left and right hindlimb during maintenance of anaesthesia with each agent, suggesting that there were differences in regional perfusion in anaesthetised horses caused by factors unrelated to agents administered.