Production of ceramics from coal fly ash

Dense ceramics are produced from fly ash from REK Bitola, Republic of Macedonia. Four types of fly ash from electro filters and one from the collected zone with particles < 0.063 mm were the subject of this research. Consolidation was achieved by pressing (P= 133 MPa) and sintering (950, 1000, 1050 and 11000C and heating rates of 3 and 100/min). Densification was realized by liquid phase sintering and solid state reaction where diopside [Ca(Mg,Al)(Si,Al)2O6] was formed. Ceramics with optimal properties (porosity 2.96±0.5%, bending strength - 47.01±2 MPa, compressive strength - 170 ±5 MPa) was produced at 1100ºC using the heating rate of 10ºC/min

Respiratorni simptomi u radnica na preradi riba na obali Jadrana u Hrvatskoj

This article describes respiratory symptoms and lung function in 98 fish processing female workers employed in a fish processing plant located on the Croatian Adriatic coast and 95 matching controls. The study included chronic and acute respiratory symptoms which developed during the shifts. Lung function measurements included forced vital capacity (FVC), one-second forced expiratory volume (FEV1) and maximal expiratory rates at 50 % and the last 25 % (FEF50, FEF25). Chronic respiratory symptoms were significantly dominant in fish processing workers compared to controls. The most common chronic symptoms were hoarseness (57.1 %), nasal catarrh (51.0 %), chronic cough (42.9 %), chronic phlegm (34.7 %), and frequent chest cold (35.7 %). Exposed smokers and nonsmokers had a similar prevalence of chronic respiratory symptoms. Acute symptoms over the work shift were high, with headache in lead (smokers: 62.5 %; nonsmokers: 56.1 %). Most of the ventilatory capacity parameters were significantly lower than predicted, FEF25 in particular, indicating obstructive changes predominantly in the smaller airways. These findings suggest that fish processing workers are prone to developing acute and chronic respiratory symptoms as well as to lung function changes. This calls for medical and technical preventive measures to be introduced in the work environment of the fi sh processing plant.Cilj je ovoga istraživanja bio ispitati respiratorne simptome i plućnu funkciju radnica zaposlenih na preradi riba u industriji na obali Jadranskog mora u Hrvatskoj. U istraživanje je uključeno 98 radnica zaposlenih na preradi riba i 95 žena neizložene kontrolne skupine. Ispitivani su kronični i akutni respiratorni simptomi koji se razvijaju tijekom radne smjene. Mjerena je plućna funkcija registriranjem forsiranoga vitalnog kapaciteta (FVC), forsiranoga ekspiracijskog volumena u prvoj sekundi (FEV1) te maksimalnoga ekspiracijskog protoka pri 50 % i zadnjih 25 % forsiranoga vitalnog kapaciteta (FEF50, FEF25) na krivulji maksimalni ekspiracijski protok-volumen (MEPV). Učestalost većine kroničnih respiracijskih simptoma bila je značajno viša u eksponiranih u usporedbi s kontrolnom skupinom. U eksponiranih radnica utvrđena je i visoka prevalencija akutnih simptoma koji se razvijaju tijekom radne smjene, posebno za promuklost (57,1 %) i katar nosa (51 %), potom slijedi kronični kašalj (42,9 %), kronični iskašljaj (34,7 %), upale sinusa (32 %) i česte prehlade (35,7 %). S obzirom na naviku pušenja pušači i nepušači imali su sličnu prevalenciju kroničnih respiratornih simptoma. Izložene radnice imale su visoku prevalenciju akutnih simptoma tijekom radne smjene i to naročito za glavobolju (pušači 62,5 %; nepušači 56,1 %). Ventilacijska funkcija pluća bila je značajno smanjena u usporedbi s predviđenim normalnim vrijednostima posebice za FEF25 % upućujući na opstruktivne promjene pretežno u manjim dišnim putovima. Naši podaci upućuju na opasnost razvoja kroničnih i akutnih respiracijskih simptoma i promjena plućne funkcije u radnika koji rade u industriji na preradi riba. Medicinske i tehničke preventivne mjere u radnom okolišu treba preporučiti u industriji prerade riba

Effect of spirometry on intra-thoracic pressures

Due to the high intra-thoracic pressures associated with forced vital capacity manoeuvres, spirometry is contraindicated for vulnerable patients. However, the typical pressure response to spirometry has not been reported. Eight healthy, recreationally-active men performed spirometry while oesophageal pressure was recorded using a latex balloon-tipped catheter. Peak oesophageal pressure during inspiration was - 47 ± 9 cmH O (37 ± 10% of maximal inspiratory pressure), while peak oesophageal pressure during forced expiration was 102 ± 34 cmH O (75 ± 17% of maximal expiratory pressure). The deleterious consequences of spirometry might be associated with intra-thoracic pressures that approach maximal values during forced expiration

Use of forced vital capacity and forced expiratory volume in 1 second quality criteria for determining a valid test

The 2005 American Thoracic Society (ATS)/European Respiratory Society (ERS) spirometry guidelines define valid tests as having three acceptable blows and a repeatable forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1). The aim of this study was to determine how reviewer and computer-determined ATS/ERS quality could affect population reference values for FVC and FEV1. Spirometry results from 7777 normal subjects aged 8–80 years (NHANES (National Health and Nutrition Examination Survey) III) were assigned quality grades A to F for FVC and FEV1 by a computer and one reviewer (reviewer 1). Results from a subgroup of 1466 Caucasian adults (aged 19–80 years) were reviewed by two additional reviewers. Mean deviations from NHANES III predicted for FVC and FEV1 were examined by quality grade (A to F). Reviewer 1 rejected (D and F grade) 5.2% of the 7777 test sessions and the computer rejected ∼16%, primarily due to end-of-test (EOT) failures. Within the subgroup, the computer rejected 11.5% of the results and the three reviewers rejected 3.7–5.9%. Average FEV1 and FVC were minimally influenced by grades A to C allocated by reviewer 1. Quality assessment of individual blows including EOT assessments should primarily be used as an aid to good quality during testing rather than for subsequently disregarding data. Reconsideration of EOT criteria and its application, and improved grading standards and training in over-reading are required. Present EOT criteria results in the exclusion of too many subjects while having minimal impact on predicted values

Smallest detectable change in volume differs between mass flow sensor and pneumotachograph

<p>Abstract</p> <p>Background</p> <p>To assess a pulmonary function change over time the mass flow sensor and the pneumotachograph are widely used in commercially available instruments. However, the smallest detectable change for both devices has never been compared. Therefore, the aim of this study is to determine the smallest detectable change in vital capacity (VC) and single-breath diffusion parameters measured by mass flow sensor and or pneumotachograph.</p> <p>Method</p> <p>In 28 healthy pulmonary function technicians VC, transfer factor for carbon monoxide (DLCO) and alveolar volume (VA) was repeatedly (10×) measured. The smallest detectable change was calculated by 1.96 x Standard Error of Measurement ×√2.</p> <p>Findings</p> <p>The mean (range) of the smallest detectable change measured by mass flow sensor and pneumotachograph respectively, were for VC (in Liter): 0.53 (0.46-0.65); 0.25 (0.17-0.36) (<it>p </it>= 0.04), DLCO (in mmol*kPa^-1*min^-1): 1.53 (1.26-1.7); 1.18 (0.84-1.39) (<it>p </it>= 0.07), VA (in Liter): 0.66. (0.53-0.82); 0.43 (0.34-0.53) (<it>p </it>= 0.04) and DLCO/VA (in mmol*kPa^-1*min^-1*L^-1): 0.22 (0.19-0.28); 0.19 (0.14-0.22) (<it>p </it>= 0.79).</p> <p>Conclusions</p> <p>Smallest detectable significant change in VC and VA as measured by pneumotachograph are smaller than by mass flow sensor. Therefore, the pneumotachograph is the preferred instrument to estimate lung volume change over time in individual patients.</p

Exhaled nitric oxide and clinical phenotypes of childhood asthma

Whether exhaled NO helps to identify a specific phenotype of asthmatic patients remains debated. Our aims were to evaluate whether exhaled NO (FENO0.05) is independently associated (1) with underlying pathophysiological characteristics of asthma such as airway tone (bronchodilator response) and airway inflammation (inhaled corticosteroid [ICS]-dependant inflammation), and (2) with clinical phenotypes of asthma

Exhaled nitric oxide and clinical phenotypes of childhood asthma

Whether exhaled NO helps to identify a specific phenotype of asthmatic patients remains debated. Our aims were to evaluate whether exhaled NO (FENO0.05) is independently associated (1) with underlying pathophysiological characteristics of asthma such as airway tone (bronchodilator response) and airway inflammation (inhaled corticosteroid [ICS]-dependant inflammation), and (2) with clinical phenotypes of asthma

Evaluation of the global lung function initiative 2012 reference values for spirometry in a Swedish population sample

Background: The Global Lung Function Initiative 2012 (GLI) reference values are currently endorsed by several respiratory societies but evaluations of applicability for adults resident in European countries are lacking. The aim of this study was to evaluate if the GLI reference values are appropriate for an adult Caucasian Swedish population. Methods: During 2008-2013, clinical examinations including spirometry were performed on general population samples in northern Sweden, in which 501 healthy Caucasian non-smokers were identified. Predicted GLI reference values and Z-scores were calculated for each healthy non-smoking subject and the distributions and mean values for FEV1, FVC and the FEV1/FVC ratio were examined. The prevalence of airway obstruction among these healthy non-smokers was calculated based on the Lower Limit of normal (LLN) criterion (lower fifth percentile) for the FEV1/FVC ratio. Thus, by definition, a prevalence of 5% was expected. Results: The Z-scores for FEV1, FVC and FEV1/FVC were reasonably, although not perfectly, normally distributed, but not centred on zero. Both predicted FEV1 and, in particular, FVC were lower compared to the observed values in the sample. The deviations were greater among women compared to men. The prevalence of airway obstruction based on the LLN criterion for the FEV1/FVC ratio was 9.4% among women and 2.7% among men. Conclusions: The use of the GLI reference values may produce biased prevalence estimates of airway obstruction in Sweden, especially among women. These results demonstrate the importance of validating the GLI reference values in different countries.Peer reviewe

Physical Activity Characteristics across GOLD Quadrants Depend on the Questionnaire Used

BACKGROUND:The GOLD multidimensional classification of COPD severity combines the exacerbation risk with the symptom experience, for which 3 different questionnaires are permitted. This study investigated differences in physical activity (PA) in the different GOLD quadrants and patient's distribution in relation to the questionnaire used. METHODS:136 COPD patients (58±21% FEV1 predicted, 34F/102M) completed COPD assessment test (CAT), clinical COPD questionnaire (CCQ) and modified Medical Research Council (mMRC) questionnaire. Exacerbation history, spirometry and 6MWD were collected. PA was objectively measured for 2 periods of 1 week, 6 months apart, in 5 European centres; to minimise seasonal and clinical variation the average of these two periods was used for analysis. RESULTS:GOLD quadrants C+D had reduced PA compared with A+B (3824 [2976] vs. 5508 [4671] steps.d-1, p<0.0001). The choice of questionnaire yielded different patient distributions (agreement mMRC-CAT κ = 0.57; CCQ-mMRC κ = 0.71; CCQ-CAT κ = 0.72) with different clinical characteristics. PA was notably lower in patients with an mMRC score ≥2 (3430 [2537] vs. 5443 [3776] steps.d-1, p <0.001) in both the low and high risk quadrants. CONCLUSIONS:Using different questionnaires changes the patient distribution and results in different clinical characteristics. Therefore, standardization of the questionnaire used for classification is critical to allow comparison of different studies using this as an entry criterion. CLINICAL TRIAL REGISTRATION:ClinicalTrials.gov NCT01388218