The effect of stress ratio on functional behavior and structural fatigue of pseudoelastic niti alloy

The influence of stress ratio on functional behavior and structural fatigue of pseudoelastic NiTi alloy are studied. With the change of the stress ratio from 0 to 0.5 the residual strain in the first and next cycles increases significantly even at lower values of maximal stress. The fatigue life of NiTi alloy increases with the decrease of stress ratio from 0.5 to 0 in the case of presenting the results depending on the stress range

Occupation, smoking, and chronic obstructive respiratory disorders: a cross sectional study in an industrial area of Catalonia, Spain

BACKGROUND: Few studies have investigated the independent effects of occupational exposures and smoking on chronic bronchitis and airflow obstruction. We assessed the association between lifetime occupational exposures and airflow obstruction in a cross-sectional survey in an urban-industrial area of Catalonia, Spain. METHODS: We interviewed 576 subjects of both sexes aged 20–70 years (response rate 80%) randomly selected from census rolls, using the ATS questionnaire. Forced spirometry was performed by 497 subjects according to ATS normative. RESULTS: Lifetime occupational exposure to dust, gases or fumes was reported by 52% of the subjects (63% in men, 41% in women). Textile industry was the most frequently reported job in relation to these exposures (39%). Chronic cough, expectoration and wheeze were more prevalent in exposed subjects with odds ratios ranging from 1.7 to 2.0 being highest among never-smokers (2.1 to 4.3). Lung function differences between exposed and unexposed subjects were dependent on duration of exposure, but not on smoking habits. Subjects exposed more than 15 years to dusts, gases or fumes had lower lung function values (FEV(1 )-80 ml, 95% confidence interval (CI) -186 to 26; MMEF -163 ml, CI -397 to 71; FEV(1)/FVC ratio -1.7%, CI -3.3 to -0.2) than non-exposed. CONCLUSION: Chronic bronchitis symptoms and airflow obstruction are associated with occupational exposures in a population with a high employment in the textile industry. Lung function impairment was related to the duration of occupational exposure, being independent of the effect of smoking

Analysis of nitrogen oxides (NOx) in the exhaled breath condensate (EBC) of subjects with asthma as a complement to exhaled nitric oxide (FeNO) measurements: a cross-sectional study

<p>Abstract</p> <p>Background</p> <p>The study of pulmonary biomarkers with noninvasive methods, such as the analysis of exhaled breath condensate (EBC), provides a useful approach to the pathophysiology of asthma. Although many recent publications have applied such methods, numerous methodological pitfalls remain. The first stage of our study consisted of validating methods for the collection, storage and analysis of EBC; we next sought to clarify the utility of analysing nitrogen oxides (NOx) in the EBC of asthmatics, as a complement to measuring exhaled nitric oxide (FeNO).</p> <p>Methods</p> <p>This hospital-based cross-sectional study included 23 controls matched with 23 asthmatics. EBC and FeNO were performed and respiratory function measured. Intra-assay and intra-subject reproducibility were assessed for the analysis of NOx in the EBC of 10 healthy subjects.</p> <p>Results</p> <p>The intraclass correlation coefficient (ICC) was excellent for intra-assay reproducibility and was moderate for intra-subject reproducibility (Fermanian's classification). NOx was significantly higher in asthmatics (geometric mean [IQR] 14.4 μM [10.4 - 19.7] vs controls 9.9 μM [7.5 - 15.0]), as was FeNO (29.9 ppb [17.9 - 52.4] vs controls 9.6 ppb [8.4 - 14.2]). FeNO also increased significantly with asthma severity.</p> <p>Conclusions</p> <p>We validated the procedures for NOx analysis in EBC and confirmed the need for assays of other biomarkers to further our knowledge of the pathophysiologic processes of asthma and improve its treatment and control.</p

Optimization of Polycrystalline CVD Diamond Seeding with the Use of sp³/sp² Raman Band Ratio

The influence of various nanodiamond colloids used for seeding nondiamond substrates in microwave plasma enhanced chemical vapour deposition diamond process was investigated. Colloids based on deionized water, isopropanol alcohol and dimethyl sulfoxide (DMSO) were used with different grain size dispersion: 150, 400 and 35 nm, respectively. The influence of growth time was also taken into consideration and bias enhanced nucleation. Microcrystalline diamond films were deposited on the seeded substrates in microwave plasma chemical vapour deposition using hydrogen-methane gas mixture. Seeding efficiency was investigated by means of scanning electron microscopy and Raman spectroscopy. Authors defined the new factor called as diamond ideality factor (di) which can give a quick estimation of quality of film and relative sp³ content. Few main peaks were identified at the following wave numbers: diamond sp³ peak 1332 $cm^{-1}$, D band peak 1355 $cm^{-1}$, C-H bending peak 1440-1480 $cm^{-1}$ and G band peak 1560 $cm^{-1}$. The best di was achieved for DMSO based colloid in all cases. The application of bias enhanced nucleation increases the diamond crystals size and the sp³/sp² ratio

Carbon nanowalls: a new versatile graphene based interface for the laser desorption/ionization-mass spectrometry detection of small compounds in real samples

International audienc

Method validation of nanoparticle tracking analysis to measure pulmonary nanoparticle content : the size distribution in exhaled breath condensate depends on occupational exposure.

Aparticle exposure assessment based on the dose deposited in the lungs would be the gold standard for the evaluation of any resulting health effects. Measuring particles in exhaled breath condensate (EBC)?a matrix containing water and airway lining fluid?could help to evaluate particle retention in the lungs. This study aimed to (1) validate a nanoparticle tracking analysis (NTA) method for determining the particle number concentration and their hydrodynamic size distribution in EBC, and (2) apply this method to EBC collected from workers exposed to soapstone (n?=?55) or quartz dust (n?=?12) and controls (n?=?11). A standard latex bead solution was used to determine the linear range, limit of detection (LOD), repeatability (coefficient of variation,CV), and bias in spiked EBC. An LM10 NanoSight instrument withNTAversion 3.1 software was used for measurement. RTubes? were used for field collection of EBC. The repeatability obtained for aD50 size distribution in EBC showed less than8%variability, with a bias<7%. The particle concentration was linear in the range 2.5?108 particles ml?1 with aLODof 4?106 particles ml?1. A recovery of 117???20% at 6.2?107 particles ml?1 was obtained with aCV<10% and a bias<20%. EBC from workers exposed to quartz, who experienced the largest exposure to silica particles, consistently exhibited a statistically significant (p?<?0.01) higher concentration of particles in their EBC, with a size distribution shift towards larger values than the other groups. Results showed that theNTAtechnique performed well for characterizing the size distribution and concentrations of particles in EBC. The technique needs to be corroborated with a larger population of workers

Silica exposure and disease in semi-precious stone craftsmen, Minas Gerais, Brazil.

Background Brazil is an exporter of precious stones and craftsmen often work in poor conditions. We assessed silica-related diseases among crystal craftsmen and the complexity of its control. Methods Case-series including 118 subjects evaluated from 2006 to 2015, based on medical interviews, chest X-rays, spirometry, and respirable silica samples. Results Median age and length of exposure were 32 and 13 years, respectively. Silicosis, with 1/0 as a threshold, was diagnosed radiologically in 57 individuals (48.3%). Respirable silica concentrations were 0.9?29.3 times greater than the Brazilian occupational exposure limit. A Receiver Operating Characteristic (ROC) curve with the same diagnosis threshold showed best discrimination at a cut point of 12.5 years of exposure, corresponding to 4.85 mg-y/m3 of cumulative silica exposure. There was a significant decline in FEV1 across radiological and cumulative silica exposure categories. Eleven individuals (9.3%) had mycobacterial diseases at baseline or follow-up. Conclusion Crystal craftsmen continue to suffer from silicosis, lung function impairment, comorbidity, and death due to silicosis. To date collective protection in some work sheds has not diminished silica levels. Long-term follow-up is needed to evaluate further improvements in preventive measures