Short-term Samples Research Articles

A novel method for determining the time-temperature superposition relationship of SBS modified bitumen: Effects of bitumen source, modifier type and aging

The time-temperature superposition principle (TTSP) is frequently applied in rheological characterization of styrene-butadiene−styrene triblock copolymer (SBS) modified bitumen (SBSMB). The time-temperature superposition relationship is traditionally determined through optimizing the horizontal displacement of isothermal curves to minimize the errors between measured and predicted rheological data. Different from traditional method, the newly proposed method can determine the time-temperature superposition relationship of SBSMB according to its special points of phase angle plateau regions in isochronal curves. Nevertheless, the validity of this new method is only demonstrated for limited sources of SBSMB in previous study. In present paper, the effects of bitumen source, modifier type and aging on validity of the newly proposed method for determining the time-temperature superposition relationship of SBSMB were investigated. The results indicated that the shape of phase angle plateau region can be totally sorted into “convex” and “S” two types for all kinds of SBSMB samples. Although the rheological properties of SBSMB are affected by different bitumen sources and modifier types, the proposed method is demonstrated to be applicable to SBSMB samples prepared by different bitumen sources and modifier types. The proposed method cannot be applied to short-term or long-term aged SBSMB samples due to disappearance of phase angle plateau region. And the shift factors of original SBSMB obtained from the newly proposed method are no longer suitable for its aged SBSMB samples.

Predicting metabolisable energy intake by free-ranging cattle using multiple short-term breath samples and applied to a pasture case-study

Context Research into improving feed efficiency by ruminant animals grazing pastures has historically been restrained by an inability to measure feed intake by large numbers of individual animals. Recent advances in portable breath measurement technology could be useful for this purpose but methodologies need to be developed. Aims To evaluate predictive models for metabolisable energy intake (MEI) by free-ranging cattle using multiple short-term breath samples and then apply these to predict MEI by free-ranging cattle in a historic grazing experiment with cattle genetically divergent for residual feed intake (feed efficiency). Methods Predictive models for MEI were developed using bodyweight (BW) data, and carbon dioxide production rate (CPR) and methane production rate (MPR) from multiple short-term breath measurements, from an experiment with long-fed Angus steers on a grain-based diet, and an experiment with short-fed Angus heifers on a roughage diet. Heat production was calculated using CPR and MPR. Energy retained (ER) in body tissue gain by steers was calculated from BW, ADG, initial and final subcutaneous fat depths, and for both groups using feeding-standards equations. Key results Metabolic mid-test BW (MBW) explained 49 and 47% of the variation in MEI in the steer and heifer experiment, respectively, and for the steers adding ADG and then subcutaneous fat gain resulted in the models accounting for 60 and then 65% of the variation in MEI. In the steer experiment, MBW with CPR explained 57% of the variation in MEI, and including MPR did not account for any additional variation. In the heifer experiment, MBW with CPR explained 50%, and with MPR accounted for 52% of the variation in MEI. Heat production plus ER explained 60, 35 and 85% of the variation in MEI in the steer and the heifer experiments, and in the pooled data from both experiments, respectively. Conclusions Multiple short-term breath measurements, together simple BW data, can be used to predict MEI by free-ranging cattle in studies in which animals do not have feed-intake or ADG recorded. Implications This methodology can be used for research into improving feed efficiency by farm animals grazing pastures.

Drug repositioning of antiretroviral ritonavir for combinatorial therapy in glioblastoma

Abstract Background The protease inhibitor ritonavir (RTV) is a clinical-stage inhibitor of the human immunodeficiency virus. In a drug repositioning approach, we here exhibit the additional potential of RTV to augment current treatment of glioblastoma, the most aggressive primary brain tumour of adulthood. Methods We explored the antitumour activity of RTV and mechanisms of action in a broad spectrum of short-term expanded clinical cell samples from primary and recurrent glioblastoma and in a cohort of conventional cell lines and non-tumour human neural controls in vitro. To validate RTV efficacy in monotherapeutic and in combinatorial settings, we used patient-derived xenograft models in a series of in vivo studies. Results RTV monotherapy induced a selective antineoplastic response and demonstrated cytostatic and anti-migratory activity at clinical plasma peak levels. Additional exposure to temozolomide or irradiation further enhanced the effects synergistically, fostered by mechanisms of autophagy and increased endoplasmic reticulum stress. In xenograft models, we consequently observed increasing overall survival under the combinatorial effect of RTV and temozolomide. Conclusions Our data establish RTV as a valuable repositioning candidate for further exploration as an adjunct therapeutic in the clinical care of glioblastoma.

Effect of ghrelin on growth performance, carcass quality, and selected serum parameters in broiler chickens

The aim of present study was to investigate the short-term and long-term effect of the peripheral administration of ghrelin on the growth performance (feed intake, weight gain, and feed conversion ratio), carcass quality, and selected serum biochemical (glucose, total cholesterol, triglyceride, and total protein) and hormonal (T 3 , T 4 , and corticostrone) indices in broiler chickens. 240 one-day-old broiler chickens were selected, and divided into three treatment groups (control and two experimental groups). On day-21 of the experimental rearing period, three experimental groups were subjected to peripheral ghrelin administration. The control consisted of birds without any administration of peptide or solution, groups G50 and G100; included birds with Ip-injection of 50 and 100 (ng/100g BW) ghrelin peptide, respectively. The peripheral administration of exogenous ghrelin during the rearing period did not affect feed intake, body weight gain (BWG), feed conversion ratio (FCR) and carcass characteristics in broiler chickens. In short-term samples taken 12h after ghrelin infusion, the glucose level was increased in ghrelin-treated groups (162 and 151 mg/dl in compared with 117 mg/dl in control; P< 0.01) and there were significant declines for TC, triglyceride, and TP in the ghrelin-treated groups (G50 and G100) compared with the control. Similarly, with short-term samples, long-term glucose level was at a greater level in G50 and G100 (182 and 200.66 mg/dl in compared with control: 133.60 mg/dl; P< 0.01). A significant decline was observed for TC and triglyceride in the ghrelin-treated groups (P<0.05). There is no significant change between groups for TP in both samples. There was a significant increase for T4 in ghrelin-treated groups (G50 and G100) compared with the control (4.55 and 4.57 ng/ml in compared with 4.20 ng/ml; P< 0.05) in long-term. In conclusion, the peripheral administration of ghrelin in broiler chickens, during the commercial rearing period did not affect the overall growth performance, carcass quality and feed conversion ratio. The infusion of exogenous ghrelin may increase the levels of serum glucose, decrease total cholesterol and triglyceride, and T 4 is increased in the long-term (and not in the short-term or 12h after administration). The effect of endogenous chicken ghrelin needs further studies.

Comparison of short-term (saliva) and long-term (hair) cortisol levels in out-patients with melancholic and non-melancholic major depression.

Major depressive episodes (MDEs) show diverse cortisol level alterations. Heterogeneity in symptom profiles, symptom severity and cortisol specimens may explain these heterogeneous results. Less severely ill out-patients with a non-melancholic MDE (NM-MDE) may have a variation in the rhythm of cortisol secretion rather than in its concentration. Cortisol measures were taken (a) over a short-term period (12 h) by measuring daily salivary output using the area under the curve with respect to the ground (AUCg) and (b) over a long-term period (3 months) in hair. Additionally, cortisol reactivity measures in saliva - the cortisol awakening response and the 30 min delta cortisol secretion after awakening (DELTA) - were investigated in 19 patients with a melancholic MDE (M-MDE) and 52 with a NM-MDE, and in 40 matched controls who were recruited from the UK and Chile. Depression severity scores were correlated with different cortisol measures. The NM-MDE group showed a decreased AUCg in comparison with controls (P = 0.02), but normal cortisol reactivity and long-term cortisol levels. The M-MDE group did not exhibit any significant cortisol alterations nor an association with depression severity scores. Higher Hamilton Rating Scale for Depression score was linked with decreased hair cortisol concentration (HCC, P = 0.05) and higher DELTA (P = 0.04) in NM-MDEs, whereas decreased HCC was the sole alteration associated with out-patients with severe M-MDEs. The contrasting short- and long-term cortisol output results are compatible with an alteration in the rhythm of cortisol secretion in NM-MDEs. This alteration may consist of large and/or intense episodes of hypercortisolaemia in moderate NM-MDEs and frequent, but brief and sharp early-morning DELTAs in its severe form. These changes may reflect the effects of environmental factors or episodes of nocturnal hypercortisolaemia that were not measured by the short-term samples used in this study.

Effect of ghrelin peripheral administration on growth performance, carcass quality, and selected serum parameters in broiler chickens

The aim of present study was to investigate the short-term and long-term effect of the peripheral administration of ghrelin on the growth performance (feed intake, weight gain, and feed conversion ratio), carcass quality, and selected serum biochemical (glucose, total cholesterol, triglyceride, and total protein) and hormonal (T3, T4, and corticostrone) indices in broiler chickens. 240 one-day-old broiler chickens were selected, and allocated into three treatment groups (control and two experimental groups). On day-21 of the rearing period, ghrelin was peripherally administrated to three experimental groups. The control group contained birds without any administration of peptide or solution, groups G50 and G100; included birds with Ip-injection of 50 and 100 (ng/100g BW) ghrelin peptide, respectively. The peripheral administration of exogenous ghrelin did not affect feed intake, body weight gain (BWG), feed conversion ratio (FCR) and carcass characteristics in broiler chickens. In short-term samples taken 12h after ghrelin infusion, the glucose level was increased in ghrelin-treated groups (162 and 151 mg/dl in G50 and G100 compared with 117 mg/dl in control; P&lt; 0.01) and there were significant declines for TC, triglyceride, and TP in the ghrelin-treated groups (G50 and G100) compared with the control. In addition, long-term glucose level has a greater value in G50 and G100 (182 and 200.66 mg/dl) compared with control (133.60 mg/dl) group (P&lt; 0.01). A significant decline was also observed for TC and triglyceride content in the ghrelin-treated groups (P&lt;0.05). There was no significant difference among groups for TP in short-term and long-term samples. There was a significant increase for T4 in ghrelin-treated groups (G50 and G100) compared with the control (4.55 and 4.57 ng/ml vs 4.20 ng/ml respectively; P&lt; 0.05) in long-term samples. In conclusion, the peripheral administration of ghrelin in broiler chickens, during the commercial rearing period did not affect the overall growth performance, carcass quality and feed conversion ratio. The infusion of exogenous ghrelin may increase the levels of serum glucose, decrease total cholesterol and triglyceride, and T4 levels are increased in the long-term (and not in the short-term or 12h after administration).

Longitudinal examination of youth readmission to mental health inpatient units.

Significant barriers exist for youth in obtaining mental health services. These barriers are exacerbated by growing demand, attributed partially to children and adolescents who have repeat hospital admissions. The purpose of this study was to identify demographic, socioeconomic and clinical predictors of readmission to inpatient psychiatric services in New Brunswick, Canada. Key demographic, support and clinical predictors of readmission were identified. The New Brunswick Discharge Abstract Database (DAD) was used to compile a cohort of all children and adolescents ages 3-19years with psychiatric hospital admissions between 1 April 2003 and 31 March 2014 (N=3825). Primary analyses consisted of Kaplan-Meier survival methods with log-rank tests to assess time-to-readmission variability, and Cox regression to identify significant predictors of readmission. In total, 27.8% of admitted children and adolescents experienced at least one readmission within the 10-year period, with 57.3% readmitted to hospital within 90days following discharge. Bivariate results indicated that male, upper-middle socioeconomic status (SES) youths aged 11-15years from nonrural communities were most likely to be readmitted. Notable predictors of increased readmission likelihood were older age, being male, higher SES, referral to care by medical practitioner, discharge to another health facility, psychosis, and previous psychiatric admission. A significant portion of the variance in readmission was accounted for by youth demographic characteristics (i.e. age, SES, geographic location) and various support structures, including referrals to inpatient care and aftercare support services. Readmission to inpatient psychiatric care among youth is affected by a number of multifaceted risk factors across individual, environmental and clinical domains. This study used provincial population-scale longitudinal administrative data to demonstrate the influence of various individual and demographic factors on likelihood of readmission, which is notably absent from the majority of studies that make use of smaller, short-term data samples. Ensuring that multiple factors outside of the clinical context are considered when examining readmission among youth may contribute to a more thorough understanding of youth hospitalization patterns.

High expression of GLI1 is associated withbetter survival in advanced SCLC.

Aberrant Sonic hedgehog (Shh) pathway signaling has been described in small cell lung cancer (SCLC), as well discrepancies, when analyzing expression of pathway components in SCLC cell lines vs tumor biopsies. Shh key component GLI1was evaluated in advanced SCLC and data correlated with patient survival. GLI1expression was analyzed by quantitative real-time polymerase chain reaction in pre-treatment fresh frozen tumor biopsies of 12advanced SCLC patients and mRNA level of GLI1was compared in short-term vs long-term survivor's samples (stratified by median survival, independent samples t-test). Expression of GLI1 mRNA was significantly higher in long-term (> 9.6months, n = 6) survivor's biopsies than in short-term (≤ 9.6months, n = 6) survivors (p = 0.0196, 95%CI: 0.000016to0.000147, two-tailed independent samples t-test). High GLI1mRNA expression in SCLC was found to be positive prognostic marker associated with longer survival. Further research is needed for validation of these results due to the small number of patients in the study.

Extraction of polycyclic aromatic compounds (PAC) and the influence on the mechanical and chemical properties of asphalt binder

As a part of Aromatics fraction in asphalt binder, polycyclic aromatic compounds (PAC) is chemical group, including some different kinds of several thousand individual compounds, which have a negative impact on the environment and human health. PAC in asphalt binder is potentially hazardous due to volatile components and leakages; therefore measurements and analyses of PAC in asphalt binder are recommended. The common method of separating asphalt binders is impractical for the analysis of PAC, thus an innovative method is proposed. Four binders are studied with their short-term and long-term aged samples. Based on the measurement of the PAC and asphaltenes contents, effects of various aging processes on the components of PAC are investigated in this paper. Furthermore, the influence of PAC on the mechanical and chemical properties of binders is studied. The results show that the PAC exhibit significant differences before and after ageing processes. Compared with the asphaltenes compound, PAC has an opposing effect on the mechanical properties of asphalt binders. On the other hand, the chemical properties of PAC is studied to explore the mechanism of the softening effect. In addition, four binary functions with PAC and asphaltenes contents are established in this study.

Intermediate structural state for maximizing the rejuvenation effect in metallic glass via thermo-cycling treatment

Annealing of metallic glasses (MGs) at temperature near glass transition temperature (Tg) triggers relaxation and often hampers their performances in service. Rejuvenation treatment of MGs by thermal cycling is recently intensively investigated. However, the mechanism responsible for the structural rejuvenation still remains elusive. In this work, we present a systematic study on the rejuvenation effect of a Zr46Cu38Al8Ag8 MG annealed at 0.9Tg for various durations, subjected to thermo-cycling treatment. It is found that well relaxed samples after long-term annealing are almost unaffected, while short-term annealed samples exhibit large rejuvenation effect by thermo-cycling treatment. Using synchrotron X-ray diffraction, we find that thermal cycling results in a disordering at the short-range scale, where the rejuvenation effect is large in a heterogeneous sample. More interestingly, the thermo-cycling treatment on intermediate structure with 20 h-annealed sample relatively exhibits a high degree rejuvenation effect, as compared to shorter- and longer-term annealed samples. This finding indicates that the activation barrier for rejuvenation strongly depends on the original structural states, e.g., free volume, inherent stress and structural heterogeneity.

Effect of short-term formaldehyde fixation on Raman spectral parameters of bone quality.

Medical knowledge of the skeleton including its structures has improved constantly over the past decades. Advanced imaging methods, mechanical testing and optical techniques have revealed insights into bone architecture and composition. Most of these advancements were possible due to the ex vivo investigation of biological tissues. Investigations of fresh tissue are generally preferred over preserved or fixed samples. However, chemical fixation is sometimes inevitable due to histological procedures or logistical reasons. The aim of this study was to investigate whether short-term chemical fixation with formaldehyde affects bone quality parameters obtained from Raman spectroscopy and if these effects last for intermediate sample storage of several hours. As formaldehyde induces cross-links to the organic components in bone tissue, we hypothesized that collagen-related parameters are particularly affected. Femurs of eight 17-week-old C57BL/6 mice were extracted and divided into two groups (N = 8 / group). Samples of the first group were fixed by immersion in 4% formaldehyde (PFA-solution) for 12h at 4°C (fixed group) while samples of the second group were left untreated (unfixed group). Raman spectroscopy was performed, and repeated after 4h, to assess whether intermediate storage time influenced the obtained results. Based on resultant spectra, mineral-to-matrix ratio, carbonate-to-phosphate ratio, carbonate-to-amide I ratio, mineral crystallinity and collagen maturity were determined. Carbonate-to-phosphate ratio was the only parameter showing a significant difference between the first and the subsequent measurements. For both groups, ratios showed a decrease in carbonate substitution compared to the first measurement (percentage decrease: 3.1% in fixed, 4.7% in unfixed). Collagen maturity of samples, which were short-term fixed with formaldehyde, was significantly lower than of fresh, unfixed samples (percentage difference: 3.8%). Our study shows that Raman spectroscopy is able to detect changes in collagen structure initiated by formaldehyde and that changes in short-term fixed samples are minimally influencing bone material properties measured with Raman spectroscopy.

Influence of graphite on the physical and rheological properties of bituminous binder before and after short-term ageing

Bitumen is commonly used as a binder in the surface course of the flexible pavement. Failures in flexible pavement are mainly due to rutting and cracking distresses that occurs during the service life of the pavement at high and low temperature respectively. To minimize these distresses, there is a need to improve the quality of the bitumen binder. In this study, graphite is considered as potential modifier of the bitumen. The objective of this paper is to investigate the effect of graphite powder on the physical and rheological properties of the bitumen binder before and after being subjected to short-term ageing. Graphite powder was blended in the bitumen in variegated percentages from 5 to 20% with an increment of 5% by weight of bitumen. The samples were simulated to short-term ageing using rolling thin film oven test. Penetration, softening point, rotational viscosity and dynamic shear rheometer tests were performed on these unaged and short-term aged samples. The result indicates an improvement in physical and rheological properties of the bitumen binder as illustrated through decrease in penetration value along with increase in softening point, viscosity and rutting resistance parameter with increase of additive content for both unaged as well as short-term aged samples. The temperature susceptibility and stripping properties of the modified binder also gets improved. However, the addition of graphite resulted in an increase in mixing and compaction temperature. Also, the addition of graphite reduced the degree of ageing of the bitumen binder as indicated through lower penetration ageing ratio, lower softening point increment, lower viscosity ageing index, lower ageing index of rutting factor and an increase in ageing index of loss tangent with increased additive content. The recommended content of graphite as modifier is 8%.

Robust Visual Tracking via Multi-Scale Spatio-Temporal Context Learning

In order to tackle the incomplete and inaccurate of the samples in most tracking-by-detection algorithms, this paper presents an object tracking algorithm, termed as multi-scale spatio-temporal context (MSTC) learning tracking. MSTC collaboratively explores three different types of spatio-temporal contexts, named the long-term historical targets, the medium-term stable scene (i.e., a short continuous and stable video sequence), and the short-term overall samples to improve the tracking efficiency and reduce the drift phenomenon. Different from conventional multi-timescale tracking paradigm that chooses samples in a fixed manner, MSTC formulates a low-dimensional representation named fast perceptual hash algorithm to update long-term historical targets and the medium-term stable scene dynamically with image similarity. MSTC also differs from most tracking-by-detection algorithms that label samples as positive or negative, it investigates a fusion salient sample detection to fuse weights of the samples not only by the distance information, but also by the visual spatial attention, such as color, intensity, and texture. Numerous experimental evaluations with most state-of-the-art algorithms on the standard 50 video benchmark demonstrate the superiority of the proposed algorithm.

Performance of Waste Cooking Oil on Aged Asphalt Mixture

Asphaltic concrete pavement is popular worldwide, but this type of pavement requires frequent maintenance and rehabilitation as it cannot cope up with the increasing number of traffic vehicles and loads. Therefore, modifying asphalt pavement to reduce the damages and defects is necessary, thereby enhancing the serviceability of pavement. This study presents the effect of waste cooking oil on asphalt mixture at different ageing conditions. A 60/70 penetration-grade asphalt binder was used, and 5% of this binder was replaced with untreated and treated waste cooking oil. Asphalt mixtures were prepared at the selected 5% optimum bitumen content and under two tests, i.e. Marshall stability and resilient modulus. The findings showed the better stability and resilient modulus of long-term aged samples incorporated with treated waste cooking oil than the unaged and short-term aged samples. The incorporation of untreated waste cooking oil caused reduced performance compared with the controlled and long-term aged samples. This result can be attributed to the high acid value of waste cooking oil. Therefore, treated waste cooking oil can be used as a binder replacement given its significantly higher performance at the mentioned ageing condition than the controlled mixture.

Warm and Humidified Versus Cold and Dry CO2 Pneumoperitoneum in Minimally Invasive Colon Resection: A Randomized Controlled Trial.

Peritoneal insufflation with warm-humidified (WH) CO2 gas during minimally invasive surgical procedures is purported to prevent hypothermia and peritoneal desiccation and is associated with decreased postoperative IL-6 levels. This randomized study's purpose was to determine the clinical impact of WH versus cold-dry (CD) CO2 in minimally invasive colon resection (MICR), and to assess perioperative plasma levels of IL-6, TIMP-1, sVEGF-R1, and HSP-70 after MICR. Operative and short-term clinical data plus perioperative blood samples were collected on MICR patients randomized to receive either WH (36.7°C, 95% humidity) or CD (room temperature, 0% humidity) CO2 perioperatively. Peritoneal biopsies were taken at the start and end of surgery. Outcomes tracked included core temperature, postoperative in-hospital pain levels, analgesia requirements, and standard recovery parameters. Preoperative and postoperative days (PODs) 1 and 3 plasma protein levels were determined via ELISA. A total of 101 patients were randomized to WH CO2 (50) or CD CO2 (51). The WH group contained more diabetics ( P = .03). There were no differences in indication, minimally invasive surgical method used, or core temperature. Pain scores were similar; however, the WH patients required less narcotics on PODs 1 to 3 ( P < .05), and less ketorolac on PODs 1 and 2 ( P < .03). No differences in length of stay, complication rates, or time to flatus/diet tolerance were noted. Plasma levels of the 4 proteins were similar postoperatively. Though insignificant, the WH group had less marked histologic changes on "end-of-case" peritoneal biopsies. This study found significantly lower pain medication requirements for PODs 1 to 3 for the WH group; however, because there were no differences in the pains scores between the groups, firm conclusions regarding WH CO2 cannot be made.

Evaluation of Drinking Water Disinfectant Byproducts Compliance Data as an Indirect Measure for Short-Term Exposure in Humans.

In the absence of shorter term disinfectant byproducts (DBPs) data on regulated Trihalomethanes (THMs) and Haloacetic acids (HAAs), epidemiologists and risk assessors have used long-term annual compliance (LRAA) or quarterly (QA) data to evaluate the association between DBP exposure and adverse birth outcomes, which resulted in inconclusive findings. Therefore, we evaluated the reliability of using long-term LRAA and QA data as an indirect measure for short-term exposure. Short-term residential tap water samples were collected in peak DBP months (May–August) in a community water system with five separate treatment stations and were sourced from surface or groundwater. Samples were analyzed for THMs and HAAs per the EPA (U.S. Environmental Protection Agency) standard methods (524.2 and 552.2). The measured levels of total THMs and HAAs were compared temporally and spatially with LRAA and QA data, which showed significant differences (p < 0.05). Most samples from surface water stations showed higher levels than LRAA or QA. Significant numbers of samples in surface water stations exceeded regulatory permissible limits: 27% had excessive THMs and 35% had excessive HAAs. Trichloromethane, trichloroacetic acid, and dichloroacetic acid were the major drivers of variability. This study suggests that LRAA and QA data are not good proxies of short-term exposure. Further investigation is needed to determine if other drinking water systems show consistent findings for improved regulation.

Thermodynamic Simulation of Reduced Activation Ferritic–Martensitic Eurofer-97 Steel

Reduced-activation ferritic-martensitic (RAFM) steels are potential candidates for structural applications in future nuclear fusion power plants. A Ta-containing Fe-based commercial thermodynamic database was employed to calculate the phase volume fractions and their chemical compositions in Eurofer-97 RAFM steel. Results of the calculations were compared to those obtained from transmission electron microscopy, atom probe tomography and dilatometric experiments performed on short-term annealed samples. Despite minor discrepancies between experimental and calculation data, our findings suggest that the employed database is effective for calculating the phase equilibrium fields for Ta-containing steels.

Diacetyl and 2,3-pentanedione in breathing zone and area air during large-scale commercial coffee roasting, blending and grinding processes.

Recently described scientific literature has identified the airborne presence of 2,3-butanedione (diacetyl) and 2,3-pentanedione at concentrations approaching or potentially exceeding the current American Conference of Industrial Hygienists' (ACGIH) Threshold Limit Values (TLVs) at commercial coffee roasting and production facilities. Newly established National Institutes of Occupational Safety and Health (NIOSH) Recommended Exposure Limits for diacetyl and 2,3-pentanedione are even more conservative. Chronic exposure to these alpha-diketones at elevated airborne concentrations has been associated with lung damage, specifically bronchiolitis obliterans, most notably in industrial food processing facilities. Workers at a large commercial coffee roaster were monitored for both eight-hour and task-based, short-term, 15-min sample durations for airborne concentrations of these alpha-diketones during specific work processes, including the coffee bean roasting, blending and grinding processes, during two separate 8-h work periods. Additionally, the authors performed real-time Fourier transform infrared spectroscopy (FTIR) analysis of the workers' breathing zone as well as the area workplace air for the presence of organic compounds to determine the sources, as well as quantitate and identify various organic compounds proximal to the roasting and grinding processes. Real-time FTIR measurements provided both the identification and quantitation of diacetyl and 2,3-pentanedione, as well as other organic compounds generated during coffee bean roasting and grinding operations. Airborne concentrations of diacetyl in the workers' breathing zone, as eight-hour time-weighted averages were less than the ACGIH TLVs for diacetyl, while concentrations of 2,3-pentanedione were below the limit of detection in all samples. Short-term breathing zone samples revealed airborne concentrations for diacetyl that exceeded the ACGIH short-term exposure limit of 0.02 parts per million (ppm) in two samples collected on a grinder operator. FTIR analysis of air samples collected from both the workers' breathing zone and area air samples revealed low concentrations of various organics with diacetyl and 2,3-pentanedione at concentrations less than the limit of detection for the FTIR methods. Neither the breathing zone nor area air samples measured using the FTIR reflected airborne concentrations of organic compounds that, when detected, approached the ACGIH TLVs or regulatory standards, when available. FTIR analysis of headspace of ground coffee beans revealed ppm concentrations of expected alpha diketones, carbon monoxide and other volatile organic compounds (VOCs). Coffee roasting and grinding, with adequate building ventilation and typical roasted bean handling and grinding, appears to generate very low, if any, concentrations of diacetyl and 2,3-pentanedione in the workers' breathing zones. This study also confirmed via FTIR that roasted coffee beans naturally generate alpha-diketones and other organic compounds as naturally occurring compounds resultant of the roasting and then released during the grinding process.

Measurement and Impact Assessment of PM&amp;lt;sub&amp;gt;10&amp;lt;/sub&amp;gt; in Ambient Air of BSCIC Bagerhat

The study measured the concentration of coarse particulate matter (PM10) in the ambient air of Bangladesh Small and Cottage Industries Corporation (BSCIC) Bagerhat in order to evaluate its impact on workers’ health. 14 known-volume air samples were obtained through Envirotech APM 541 PM10 Particulate Sampler. The short-term (6 hours) samples were taken from 9 industrial units in the winter season of October, 2015 to January, 2016. Simple gravimetric analysis showed large variations in concentrations in distinct industrial units. The minimum concentration was found 33.61 μ/m3 in the outdoor premises of a coconut oil mill and the maximum was found 471.38 μ/m3 in the house of a rice mill. The pollutant sources were detected as cabinless husking machines and soot from boilers and fryers. A questionnaire survey was conducted to evaluate the mostly occurring symptoms of Chronic Obstructive Pulmonary Diseases (COPD) and bronchoconstriction among workers. The highest prevalence of symptoms of bronchoconstriction (OR = 7.1; 95% CI = 2.3 - 21.9) was found among workers in rice mills and eye disturbances (OR = 2.7; 95% CI = 0.9 - 8.6) had the highest prevalence in coconut mills. Monitoring of air quality, providing personal respiratory prevention and improvement in machineries were required in the study area for a healthy environment.

Estimation of personal exposure to asbestos of brake repair workers.

Exposure assessments are key tools to conduct epidemiological studies. Since 2010, 28 riveters from 18 brake repair shops with different characteristics and workloads were sampled for asbestos exposure in Bogotá, Colombia. Short-term personal samples collected during manipulation activities of brake products, and personal samples collected during non-manipulation activities were used to calculate 103 8-h TWA PCM-equivalent personal asbestos concentrations. The aims of this study are to identify exposure determinant variables associated with the 8-h TWA personal asbestos concentrations among brake mechanics, and propose different models to estimate potential asbestos exposure of brake mechanics in an 8-h work-shift. Longitudinal-based multivariate linear regression models were used to determine the association between personal asbestos concentrations in a work-shift with different variables related to work tasks and workload of the mechanics, and some characteristics of the shops. Monte Carlo simulations were used to estimate the 8-h TWA PCM-Eq personal asbestos concentration in work-shifts that had manipulations of brake products or cleaning activities of the manipulation area, using the results of the sampling campaigns. The simulations proposed could be applied for both current and retrospective studies to determine personal asbestos exposures of brake mechanics, without the need of sampling campaigns or historical data of air asbestos concentrations.