Mean Exposure Time Research Articles

Esophageal Hypomotility Is Associated with Rejection Post Lung Transplantation

Introduction: Gastroesophageal reflux is a known contributor to rejection after lung transplantation; however, the impact of esophageal dysmotility on graft survival is unknown. The aim of our study is to assess the impact of esophageal dysmotility on lung transplant rejection. Methods: 41 Lung transplant recipients who had high-resolution esophageal manometry (HRM) performed at our institution between 6/2013 and 1/2016 were included. HRM data according to the Chicago Classification, available pH and pH-impedance reports, and transplant outcome data were reviewed. Rejection was determined based on documentation of chronic or acute rejection as defined by transbronchial biopsy or poor FEV1 response post-transplant. Rejection was compared in 4 motility subgroups: 1) hypomotility - all HRM studies with 50% or more failed peristalsis, weak peristalsis, or large breaks, 2) other dysmotility -comprised of achalasia, Jackhammer and esophagogastric junction outflow obstruction (EGJOO), 3) all dysmotility, and 4) normal. We compared mean acid exposure time (AET), DeMeester score (DM), bolus exposure time (BET), and total reflux events across rejection outcome and by motility subgroup in the 38 patients that had both HRM and reflux testing. Results: For our rejection analysis, 23 and 22 patients with pre-transplant HRM and reflux data, respectively, were included. Demographics and clinical data are displayed in table 1. Table 2a displays odds ratios for rejection in the different motility subgroups. A significant difference in rejection was found between the hypomotility group vs all others (odds-ratio 9, p=0.02). Table 2b shows reflux parameters in motility subgroups and by rejection outcome. Of the reflux parameters, elevated total reflux events correlated with rejection in off-PPI studies (p=0.03). All reflux measures were worst in the hypomotility group with the exception of AET, which was highest in the normals. Significant differences in all measures were found between hypomotility and other dysmotility groups.Table 2: Motility and Reflux ResultsConclusion: Hypomotility on pre-transplant HRM is associated with rejection after lung transplantation. This effect is independent of AET and DM and correlates closest with BET and total reflux events. EGJOO without weak peristalsis and hypercontraction appear to have a good prognosis after transplant.Table 1: Clinical Data

Socio-Demographic and Clinical Characteristics of Turkish Workers with Pneumoconiosis

Pneumoconiosis is caused by inhaling dust. The aim of the study was to analyze 208 cases of workers' pneumoconiosis. Patients' files were used for the descriptive study. All patients were male aged 38.82±13 years. The most important symptom was breathlessness. Patients were denim sandblasters (50.5%), dental technicians (12%), coal miners (6.7%), and others. The mean exposure time before pneumoconiosis occurred was shorter in denim sandblasters and teflon kitchenware producers compared to other occupations (5.4±4.2 and 4.5±3.3 years, respectively). Profusion (76.5%) was more than 1/2 by the International Labour Organization (ILO) classification. Pulmonary function tests were negatively correlated with profusion. Denim sandblasters and teflon kitchenware producers have less exposure time before pneumoconiosis occurs and they become symptomatic earlier. As Turkish workers suffering from pneumoconiosis are younger, measures to prevent pneumoconiosis must be the priority of the healthcare authorities.

Exposure to pesticides and pulmonary function impairment in a rural population in northwest of Rio de Janeiro State, Brazil.

Introduction: Excessive use of pesticides in agriculture is a major risk to respiratory health, especially for rural population. São José de Ubá (SJU) is a small community and has its economy based on family farming with tomato cultivation and intensive use of pesticides. Objective: To evaluate pulmonary function in rural workers and family members involved in agricultural production in SJU. Methods: Cross-sectional study with a convenience sample conducted during the harvest (2014) with 45 rural workers and 27 relatives. Linear regressions were performed considering exposure variables to pesticides (identified in previous interview) and percentages of predicted values found in spirometry (according to Brazilian Society of Pneumology – SBPT) with significant P value (confidence intervals: 95%). Results: Rural workers and their relatives are exposed to pesticides from early age, whether working or helping in cultivation. Majority of individuals has never been trained to handle pesticides and is exposed occupationally and domestically. The mean age and exposure time (in years) were 42.9 and 30.2 years for rural workers and 45.7 and 18.8 years for relatives. Although most individuals affirmed to use personal protective equipment, we did not find any individual wearing complete equipment or using respiratory protection. Changes in Forced Expiratory Flow (FEF25-75%) were associated with the fact of being a producer (p = 0.008), handling pesticides regularly (p = 0.034) and hours worked per day (p = 0.003). Changes in Forced Expiratory Volume in 1st second/Forced Vital Capacity (FEV1/FVC ratio) were associated with the fact of being a producer (p = 0.04) and hours worked per day (p = 0.02), but lost its significance when adjusted for smoking. Conclusions: The rural population studied presented lung function impairment associated with pesticide exposure. Findings suggest the importance of implementation of public policies and training to reduce risk and health effects.

Exposure-time based modeling of nonlinear reactive transport in porous media subject to physical and geochemical heterogeneity

Transport of reactive solutes in groundwater is affected by physical and chemical heterogeneity of the porous medium, leading to complex spatio-temporal patterns of concentrations and reaction rates. For certain cases of bioreactive transport, it could be shown that the concentrations of reactive constituents in multi-dimensional domains are approximately aligned with isochrones, that is, lines of identical travel time, provided that the chemical properties of the matrix are uniform. We extend this concept to combined physical and chemical heterogeneity by additionally considering the time that a water parcel has been exposed to reactive materials, the so-called exposure time. We simulate bioreactive transport in a one-dimensional domain as function of time and exposure time, rather than space. Subsequently, we map the concentrations to multi-dimensional heterogeneous domains by means of the mean exposure time at each location in the multi-dimensional domain. Differences in travel and exposure time at a given location are accounted for as time difference. This approximation simplifies reactive-transport simulations significantly under conditions of steady-state flow when reactions are restricted to specific locations. It is not expected to be exact in realistic applications because the underlying assumption, such as neglecting transverse mixing altogether, may not hold. We quantify the error introduced by the approximation for the hypothetical case of a two-dimensional, binary aquifer made of highly-permeable, non-reactive and low-permeable, reactive materials releasing dissolved organic matter acting as electron donor for aerobic respiration and denitrification. The kinetically controlled reactions are catalyzed by two non-competitive bacteria populations, enabling microbial growth. Even though the initial biomass concentrations were uniform, the interplay between transport, non-uniform electron-donor supply, and bio-reactions led to distinct spatial patterns of the two types of biomass at late times. Results obtained by mapping the exposure-time based results to the two-dimensional domain are compared with simulations based on the two-dimensional, spatially explicit advection-dispersion-reaction equation. Once quasi-steady state has been reached, we find a good agreement in terms of the chemical-compound concentrations between the two approaches inside the reactive zones, whereas the exposure-time based model is not able to capture reactions occurring in the zones with zero electron-donor release. We conclude that exposure-time models provide good approximations of nonlinear bio-reactive transport when transverse mixing is not the overall controlling process and all reactions are essentially restricted to distinct reactive zones.

PWE-083 Behavioural Gastro-Oesophageal Reflux Disease Caused by Supragastric Belching

Introduction Supragastric belching (SGB) is considered to be a behavioural phenomenon, thus gastro-oesophageal reflux disease (GORD) caused by SGB can be considered as behavioural GORD. Behavioural GORD may necessitate differential treatment to ‘classical’ GORD and therefore requires diagnosis as a distinct clinical entity. This study aims to establish the prevalence of GOR events caused by SGB and evaluate the associated demographic features, symptoms and oesophageal motility abnormalities. Methods The Oesophageal Physiology Laboratory, Guy’s Hospital, patient database was retrospectively searched for patients diagnosed with GORD in whom SGB was observed. Patient demographic information, symptoms and oesophageal motility abnormalities were collected. The 24 hour pH-impedance studies were analysed for SGB. GORD events closely following SGB (within 6 seconds) were quantified and the acid exposure time and acid/non-acid reflux events occurring after a SGB were calculated when upright and recumbent. Results Forty-six patients with a diagnosis of GORD and SGB were identified (48% female, mean age 50.5 years (range: 29–75), male mean age 52.5 years (29–79)). Ninety-five percent of patients reported heartburn and/or epigastric pain, 81.8% suffered from excessive belching, 63.6% reported regurgitation and 54.5% reported dysphagia. Forty-three percent of patients had a hypotensive lower oesophageal sphincter (LOS). SGB preceded 22.7% of all reflux events (24.9% upright and 6.6% recumbent) and 26.5% of acid reflux events. On average, over 24 hours, 16.3 reflux events were associated with SGB (13.0 acid and 4.1 non-acid) corresponding to a mean acid exposure time of 17.8 minutes. In this cohort SGB accounted for 17% of acid exposure time (22% upright and 7.4% recumbent). SGB had no effect on the total number of reflux events or the total acid exposure time in 3 patients and in 3 further patients SGB had no effect on the total acid exposure time. SGB caused ≥50% of the total number of reflux events in 3 patients and ≥50% of the total acid exposure time in 5 patients. Patients with a hypotensive LOS did not have a significantly higher total number of reflux events (p = 0.88) or total acid exposure time (p = 0.86). No relationships were seen between the presence of a hiatus hernia and the total number of reflux events (p = 0.43) or acid exposure time (p = 0.16) associated with SGB. Conclusion SGB induced a considerable proportion of reflux events and acid exposure time. In 8 patients SGB caused ≥50% of the total reflux events or overall acid exposure time, and hence these patients may be considered as having behavioural GORD. Behavioural GORD should be diagnosed and treated separately to ‘classical’ GORD. Further work is required to elucidate the cause and pathophysiology of SGB. Disclosure of Interest None Declared

Establishment of local diagnostic reference levels for quality control in intraoral radiography

ObjectiveTo investigate the dosage and imaging conditions for patients undergoing intraoral radiography at Meikai University Hospital and establish assurance and quality control data.MethodsTube voltage, exposure time, and air kinetic energy released per unit mass (air kerma) of three intraoral radiography units were measured. To calculate the patient entrance dose (PED) for each radiograph using Insight film, we extracted data for 1063 patients from their exposure records. The PED was compared with the diagnostic reference level (DRL) from the European Commission and the UK.ResultsThe tube voltage of the three units was maintained at 60 ± 2 kV. Differences in exposure time were less than 1.7 % for all units. The air kerma rates were well maintained within a 4.2 % error. Based on the patient data, there were no significant differences in the mean exposure times for males and females for all anatomical sites. The mean PED ranged from 1.09 ± 0.31 mGy for the mandibular incisors to 2.42 ± 0.33 mGy for the maxillary molars. The mean PED at the mandibular molars using InSight film was 1.59 ± 0.20 mGy, being less than the recommended value based on the DRL for intraoral radiography in the UK.ConclusionsWe concluded that radiographic conditions at the hospital have been properly maintained. This basic quality control data may assist other dental radiation facilities to reduce patient dosage.

Growth dynamics of the seagrass Zostera japonica at its upper and lower distributional limits in the intertidal zone

The seagrass Zostera japonica occurs mainly in the intertidal zone and is thus exposed to widely varying environmental conditions affecting its growth and distribution compared to subtidal seagrasses. The growth dynamics of Z. japonica at its upper and lower distributional limits in the intertidal zone were investigated in Koje Bay on the southern coast of Korea to examine the environmental stresses and limiting factors on the growth of intertidal seagrasses. The shoot density and morphology, biomass, and leaf productivity of Z. japonica were measured in relation to coincident measurements of environmental factors at its upper and lower distributional limits and in an intermediate zone of the intertidal area. The mean exposure time to the atmosphere during low tide in the upper intertidal zone was approximately 1.5- and 1.9-fold longer than that in the intermediate and lower intertidal zones, respectively. Shoot density and biomass were significantly higher in the intermediate zone than at the upper and lower distributional limits. Longer emersion leading to a various of environmental stresses appeared to reduce Z. japonica growth in the upper intertidal zone, whereas interspecific competitive interactions related to irradiance seemed to affect Z. japonica growth in the lower intertidal zone. Shoot size, density, biomass, and leaf productivity were lower in the upper than in the lower zone, implying that emersion-associated stresses in the upper zone had a greater detrimental effect on Z. japonica growth than did stresses occurring in the lower zone. The productivity of Z. japonica showed strong positive correlations with air and water temperature, suggesting enhancement of Z. japonica production at higher temperatures. Thus, the predicted increases in air and water temperature associated with global climate change might have positive effects on the growth and extension in distributional range of this species.

Photo inactivation of virus particles in microfluidic capillary systems.

It has long been established that UVC light is a very effective method for inactivating pathogens in a fluid, yet the application of UVC irradiation to modern biotechnological processes is limited by the intrinsic short penetration distance of UVC light in optically dense protein solutions. This experimental and numerical study establishes that irradiating a fluid flowing continuously in a microfluidic capillary system, in which the diameter of the capillary is tuned to the depth of penetration of UVC light, uniquely treats the whole volume of the fluid to UVC light, resulting in fast and effective inactivation of pathogens, with particular focus to virus particles. This was demonstrated by inactivating human herpes simplex virus type-1 (HSV-1, a large enveloped virus) on a dense 10% fetal calf serum solution in a range of fluoropolymer capillary systems, including a 0.75 mm and 1.50 mm internal diameter capillaries and a high-throughput MicroCapillary Film with mean hydraulic diameter of 206 μm. Up to 99.96% of HSV-1 virus particles were effectively inactivated with a mean exposure time of up to 10 s, with undetectable collateral damage to solution proteins. The kinetics of virus inactivation matched well the results from a new mathematical model that considers the parabolic flow profile in the capillaries, and showed the methodology is fully predictable and scalable and avoids both the side effect of UVC light to proteins and the dilution of the fluid in current tubular UVC inactivation systems. This is expected to speed up the industrial adoption of non-invasive UVC virus inactivation in clinical biotechnology and biomanufacturing of therapeutic molecules. Biotechnol. Bioeng. 2016;113: 1481-1492. © 2015 Wiley Periodicals, Inc.

Arsenic acute toxicity assessment on select freshwater organism species in Malaysia

Recently, arsenic has contaminated the aquatic ecosystem, raising government and public environmental concern. In this study, four freshwater organisms were used to evaluate arsenic toxicity levels. Two types of fish, namely Poecilia reticulata (guppy) (Poeciliidae) and Rasbora Sumatrana (Cyprinidae), an aquatic worm species Tubifex tubifex (Oligochaeta) and diptera midge larvae Chironomus javanus (Chironomidae) were exposed for a 4-day (96 h) period in laboratory conditions to a range of arsenic (As) concentrations. Mortality was assessed and median lethal times (LT50) and concentrations (LC50) were calculated. The objective of this study is to determine the acute toxicity of arsenic concentration on Poecilia reticula, Rasbora sumatrana, Tubifex tubifex and Chironomus javanus. Results showed that LT50 and LC50 increase with the decrease in mean exposure concentrations and times. Results indicated that Tubifex tubifex was most sensitive to arsenic toxicity compared to other organisms used in this study in this order; Tubifex tubifex > Chironomus javanus > Rasbora sumatrana > Poecilia reticulata.

Theoretical estimates of exposure timescales of protein binding sites on DNA regulated by nucleosome kinetics.

It is being increasingly realized that nucleosome organization on DNA crucially regulates DNA–protein interactions and the resulting gene expression. While the spatial character of the nucleosome positioning on DNA has been experimentally and theoretically studied extensively, the temporal character is poorly understood. Accounting for ATPase activity and DNA-sequence effects on nucleosome kinetics, we develop a theoretical method to estimate the time of continuous exposure of binding sites of non-histone proteins (e.g. transcription factors and TATA binding proteins) along any genome. Applying the method to Saccharomyces cerevisiae, we show that the exposure timescales are determined by cooperative dynamics of multiple nucleosomes, and their behavior is often different from expectations based on static nucleosome occupancy. Examining exposure times in the promoters of GAL1 and PHO5, we show that our theoretical predictions are consistent with known experiments. We apply our method genome-wide and discover huge gene-to-gene variability of mean exposure times of TATA boxes and patches adjacent to TSS (+1 nucleosome region); the resulting timescale distributions have non-exponential tails.

Positioning of earphones and variations in auditory thresholds

IntroductionOne of the problems observed in pure-tone audiometry tonal has been the variation in test results of a same individual, particularly at frequencies of 4kHz, 6kHz and/or 8kHz. Improper placement of headphones is one of the factors that can cause alterations in results. ObjectiveTo compare differences in auditory thresholds using earphones positioned by the examiner and by the worker. MethodsClinical and experimental study conducted in 2009, with 324 workers aged between 19 and 61 years, with a mean of 33.29 years and mean exposure time of 7.67 years. All subjects were familiar with audiometry procedures. Auditory thresholds were obtained at frequencies of 0.25–8kHz, with earphones positioned by the examiners, and at frequencies of 4, 6 and 8kHz, with earphones placed by workers in a comfortable position, following the examiner's instructions. The thresholds obtained in these two situations were compared. ResultsThe three frequencies exhibited better responses with earphones placed by the workers themselves (p<0.001). At a frequency of 8kHz a greater difference was found (p<0.001), with a mean of 13.89dB and standard deviation of 6.07dB. ConclusionEarphone placement by the workers themselves under supervision of the examiner results in improved mean auditory thresholds at frequencies of 4, 6 and 8kHz, the last one significantly higher than the other two.

Cardiology News / Recent Literature Review / Second Quarter 2015

ESC Congress : London, 29/8-2/9/2015 TCT Meeting 2015: San Francisco, 11-15/10/2015 HCS Congress: Thessaloniki, 29-31/10/2015 AHA Scientific Sessions: Orlando, 7-11/11/2015 DAPT Study: Continuation of Dual Antiplatelet Therapy After PCI in Patients With and Without Acute Myocardial Infarction Beyond 1 Year Reduced Ischemic Events, but Increased Bleeding Compared With Treatment With Aspirin Alone Among 11,648 randomized patients (9,961 treated with drug-eluting stents, 1,687 with bare-metal stents), 30.7% presenting with MI, between 12 and 30 months, continued thienopyridine reduced stent thrombosis compared with placebo in patients with and without MI at presentation (MI group, 0.5% vs 1.9%, p< 0.001; no MI group, 0.4% vs. 1.1%, p< 0.001). The reduction in major adverse cardiovascular and cerebrovascular events (MACCE) for continued thienopyridine was greater for patients with MI (3.9% vs 6.8%; p< 0.001 for MI; 4.4% vs 5.3%; p= 0.08 for no MI). In both groups, continued thienopyridine reduced MI (2.2% vs 5.2%, p< 0.001 for MI; 2.1% vs 3.5%, p< 0.001 for no MI) but increased bleeding (1.9% vs 0.8%, p= 0.005 for MI; 2.6% vs 1.7%, p= 0.007 for no MI). The authors concluded that extended dual antiplatelet therapy reduced the risk of stent thrombosis and MI in patients with and without MI, but increased bleeding (Yeh RW et al, J Am Coll Cardiol 2015;65:2211-2221). Metaanalysis: Dual Antiplatelet Therapy (DAPT) is Associated With Protection Against Stent Thrombosis but Increases Risk of Bleeding in Patients With Drug Eluting Stents (DES) / Benefit of Extended DAPT for Patients With First-Generation DES, but not for Second-Generation DES Metaanalysis of 10 randomized controlled trials (N = 32,135) indicated that compared to longer duration DAPT (L-DAPT; mean exposure time 20.3 months for second-generation DES and 28 months for first-generation DES), shorter duration DAPT (S-DAPT; mean exposure time 7.8 months for second-generation DES and 10.9 months for first-generation DES) had an overall higher rate of stent thrombosis (odds ratio - OR: 1.71; p = 0.001). The effect of S-DAPT on stent thrombosis was attenuated with the use of second-generation DES (OR: 1.54) compared with first-generation DES (OR: 3.94; p for interaction = 0.008). S-DAPT had an overall significantly lower risk of bleeding (OR: 0.63; p < 0.001). Finally, a numerically lower all-cause mortality rate was observed with S-DAPT (OR: 0.87; p = 0.073). The authors concluded that S-DAPT had overall lower rates of bleeding yet higher rates of stent thrombosis compared with L-DAPT; the latter effect was significantly attenuated with the use of second-generation DES. All-cause mortality was higher (not statistically) with L-DAPT (Giustino G et al, J Am Coll Cardiol 2015;65:1298-1310)... (excerpt)

Effects of Popularity-Based News Recommendations (“Most-Viewed”) on Users' Exposure to Online News

This experimental study (N = 107) aims at investigating how the “most-viewed” recommendation features of online news affect users' news story choices, by employing an unobtrusive measurement for news exposure. The major findings clearly support the thesis that the presence of recommendations influences users' selection of news stories. First, the participants' self-reported assessment of the reasons for their story choices indicates that the incorporation of recommendations heightened their awareness of formal salience features. Second, these recommendations decreased the time for website exploration, and therefore increased the time available for reading news articles. Third, when the recommender system was available, approximately 50% of the participants' total story exposures came through the recommendation features. Fourth, those participants who were in the recommendation condition selected a larger number of the most-viewed stories featured in the recommender system than their counterparts in the no-recommendation condition; and a majority (about 80%) of the former group's access to those most-viewed stories was via the recommender system, in terms of either number or time. Last, the mean exposure time per recommended story did not differ across either recommendation conditions (with vs. without) or access routes (recommender system vs. front/topical sections).

Bacterial Contamination in Tips of Electrocautery Devices During Total Hip Arthroplasty

Surgical equipment can become contaminated during surgery. It is unknown if electrocautery tips can become contaminated in clean orthopedic procedures despite the produced heat. Therefore, we conducted a prospective study to address this concern. The tips from 25 primary and 25 aseptic revision THAs were collected and an additional 5 sterile tips served as negative controls. Aerobic and anaerobic cultures were incubated for a minimum of 3days. There were 3 positive cultures (6%); one in primary THA (4%) with Lactobacillus and Enterococcus faecalis; two among revisions (8%), one with E. faecalis and another one with alpha hemolytic streptococci and coagulase negative Staphylococcus. The mean exposure time of the contaminated tips was 132.3minutes. Patients were followed for 90days postoperatively and none of them developed surgical site infection. This is the first study to demonstrate that electrosurgical devices can become contaminated during THA in laminar flow equipped operating rooms.

Association Between Baseline Impedance Values and Response Proton Pump Inhibitors in Patients With Heartburn

Esophageal impedance measurements have been proposed to indicate the status of the esophageal mucosa, and might be used to study the roles of the impaired mucosal integrity and increased acid sensitivity in patients with heartburn. We compared baseline impedance levels among patients with heartburn who did and did not respond to proton pump inhibitor (PPI) therapy, along with the pathophysiological characteristics of functional heartburn (FH). In a case-control study, we collected data from January to December 2013 on patients with heartburn and normal findings from endoscopy who were not receiving PPI therapy and underwent impedance pH testing at hospitals in Italy. Patients with negative test results were placed on an 8-week course of PPI therapy (84 patients received esomeprazole and 36 patients received pantoprazole). Patients with more than 50% symptom improvement were classified as FH/PPI responders and patients with less than 50% symptom improvement were classified as FH/PPI nonresponders. Patients with hypersensitive esophagus and healthy volunteers served as controls. In all patients and controls, we measured acid exposure time, number of reflux events, baseline impedance, and swallow-induced peristaltic wave indices. FH/PPI responders had higher acid exposure times, numbers of reflux events, and acid refluxes compared with FH/PPI nonresponders (P < .05). Patients with hypersensitive esophagus had mean acid exposure times and numbers of reflux events similar to those of FH/PPI responders. Baseline impedance levels were lower in FH/PPI responders and patients with hypersensitive esophagus, compared with FH/PPI nonresponders and healthy volunteers (P < .001). Swallow-induced peristaltic wave indices were similar between FH/PPI responders and patients with hypersensitive esophagus. Patients with FH who respond to PPI therapy have impedance pH features similar to those of patients with hypersensitive esophagus. Baseline impedance measurements might allow for identification of patients who respond to PPIs but would be classified as having FH based on conventional impedance-pH measurements.

A longitudinal comparison of hemodynamics and intraluminal thrombus deposition in abdominal aortic aneurysms.

Abdominal aortic aneurysm (AAA) is often accompanied by in traluminal thrombus (ILT), which complicates AAA progression and risk of rupture. Patient-specific computational fluid dynamics modeling of 10 small human AAA was performed to investigate relations between hemodynamics and ILT progression. The patients were imaged using magnetic resonance twice in a 2- to 3-yr interval. Wall content data were obtained by a planar T1-weighted fast spin echo black-blood scan, which enabled quantification of thrombus thickness at midaneurysm location during baseline and followup. Computational simulations with patient-specific geometry and boundary conditions were performed to quantify the hemodynamic parameters of time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), and mean exposure time at baseline. Spatially resolved quantifications of the change in ILT thickness were compared with the different hemodynamic parameters. Regions of low OSI had the strongest correlation with ILT growth and demonstrated a statistically significant correlation coefficient. Prominent regions of high OSI (>0.4) and low TAWSS (<1 dyn/cm(2)) did not appear to coincide with locations of thrombus deposition.

Hearing Loss in Relation to Sound Exposure of Professional Symphony Orchestra Musicians

The objectives of this study were to: (1) estimate the hearing status of classical symphony orchestra musicians and (2) investigate the hypothesis that occupational sound exposure of symphony orchestra musicians leads to elevated hearing thresholds. The study population comprised all the musicians from five symphony orchestras. Questionnaires were filled in by 337 subjects, and 212 subjects performed an audiometric test. For a group of 182 musicians (363 ears) the results of the audiometry was analyzed in relation to the individual exposure, which was estimated on the basis of sound measurements and questionnaire data regarding the exposure time. The mean hearing threshold at the frequencies 3, 4, and 6 kHz, corrected for age and sex, was used as outcome. The musician ears with the highest exposure (29 of 363) had an additional threshold shift of 6.3 dB compared with the 238 ears with lowest exposure. The observed hearing loss of musicians was smaller compared with the noise-induced permanent threshold shift (NIPTS) predicted from ISO1999. A remaining confounding effect of age after ISO7029 age corrections could be observed to explain the difference in observed and predicted NIPTS. However, the observed hearing loss difference between the left and the right ear of musicians was 2.5 dB (95% confidence interval 1.5-3.6), which was similar to the NIPTS predicted from ISO1999. Most of the musicians had better hearing at 3, 4, and 6 kHz for age than expected, however, 29 ears with the highest exposure above 90.4 dBA with a mean exposure time of 41.7 years had significantly elevated hearing thresholds. Trumpet players and the left ear of first violinists had significantly elevated hearing thresholds compared with other musicians. Most of the symphony orchestra musicians had better hearing than expected but they had a work-related risk of developing additional noise-induced hearing loss. The additional NITPS of the left ear compared with the right ear was at the expected level based on the cumulated sound exposure and ISO1999, indicating that performing music may induce hearing loss to the same extent as industrial noise.

Delayed polyneuropathy in farm sprayers due to chronic low dose pesticide exposure.

Background:The use of organophosphates (OPs) in developing countries is rising in large quantities and non-secure methods. This problem not only causes acute poisoning but also may lead to chronic diseases such as polyneuropathy. In Iran, 60% of pesticides are organophosphate compounds that may lead to delayed polyneuropathy.Objectives:The purpose of the current study was to evaluate delayed polyneuropathy in farm sprayers due to chronic low dose pesticide exposure.Patients and Methods:In our cross-sectional study, non-randomized sampling method was performed and 100 farm sprayers (cases) and 100 hospital personnel (controls) after precise systemic and neurological examination were recruited to this study from June 2011 to august 2011. The nerve conduction studies were performed and these indices were recorded: Compound Muscle Action Potential (CMAP), amplitude and Distal Latency (DL) and Nerve Conduction Velocity (NCV) of common peroneal nerve, Peak Latency (PL) and amplitude of Sensory Nerve Action Potential (SNAP) and Nerve Conduction Velocity (NCV) of sural and radial sensory nerves.Results:Among 100 cases, 55 farm sprayers complained of non-neurological problems including: ophthalmologic, dermatologic and pulmonary complications. The ophthalmologic complaints (44%) were the most. The mean peroneal CMAP amplitude and NCV, sural PL, radial SNAP amplitude, PL and NCV in the case group were significantly different compared to control group. Mean exposure time to OPs in farm sprayers without neurological problem (40%) was 11.81 ± 5.84 years but in farm sprayers with neurological problems (60%) was 15.70 ± 9.08 years, which represents the effect of OPs exposure duration on neurologic problems.Conclusions:Chronic low dose pesticide exposure could lead to delayed peripheral neuropathy as well as systemic (skin, eyes and lungs) complications. In farm sprayers electrodiagnostic indices were significantly abnormal as compared to control group. The normal indices did not rule out neurologic involvement and it seems that measurement of these indices at the beginning of the farm sprayers employment and intermittently during their work is helpful for detecting delayed polyneuropathy.

Superior bactericidal activity of N-bromine compounds compared to their N-chlorine analogues can be reversed under protein load.

To investigate and compare the bactericidal activity (BA) of active bromine and chlorine compounds in the absence and presence of protein load. Quantitative killing tests against Escherichia coli and Staphylococcus aureus were performed both in the absence and in the presence of peptone with pairs of isosteric active chlorine and bromine compounds: hypochlorous and hypobromous acid (HOCl and HOBr), dichloro- and dibromoisocyanuric acid, chlorantine and bromantine (1,3-dibromo- and 1,3 dichloro-5,5-dimethylhydantoine), chloramine T and bromamine T (N-chloro- and N-bromo-4-methylbenzenesulphonamide sodium), and N-chloro- and N-bromotaurine sodium. To classify the bactericidal activities on a quantitative basis, an empirical coefficient named specific bactericidal activity (SBA), founded on the parameters of killing curves, was defined: SBA= mean log reductions/(mean exposure times x concentration) [mmol 1(-1) min (-1)]. In the absence of peptone, tests with washed micro-organisms revealed a throughout higher BA of bromine compounds with only slight differences between single substances. This was in contrast to chlorine compounds, whose killing times differed by a factor of more than four decimal powers. As a consequence, also the isosteric pairs showed according differences. In the presence of peptone, however, bromine compounds showed an increased loss of BA, which partly caused a reversal of efficacy within isosteric pairs. In medical practice, weakly oxidizing active chlorine compounds like chloramines have the highest potential as topical anti-infectives in the presence of proteinaceous material (mucous membranes, open wounds). Active bromine compounds, on the other hand, have their chance at insensitive body regions with low organic matter, for example skin surfaces. The expected protein load is one of the most important parameters for selection of a suited active halogen compound.

Aging of solar absorber materials under highly concentrated solar fluxes

This article introduces an experimental approach to study the aging of absorber materials used in the receivers of CSP power plants. The term ‘aging’ is discussed in the case of solar absorber materials and a definition is suggested. A two-layer material (metal+paint coating) that is commonly used in solar tower receivers is studied. Accelerated aging tests are performed on this material with the Solar Accelerated Aging Facility (SAAF) available at PROMES laboratory (Odeillo, France). To evaluate the aging state of the samples after being solar-treated, the thermoradiative and thermophysical properties that characterize the aging of the coating are estimated with two experimental devices. The results show the influence of the mean irradiance, amplitude, period, and exposure time of the radiative cycles on the estimated properties. The absorptance appears to be the most sensitive property causing the thermal performance to decrease. Particular attention should be paid to the application of the paint coating which needs to be vitrified carefully in order to obtain optimal and stable absorption properties.