Towards microfluidic reactors for in situ synchrotron infrared studies.

Anodically bonded etched silicon microfluidic devices that allow infrared spectroscopic measurement of solutions are reported. These extend spatially well-resolved in situ infrared measurement to higher temperatures and pressures than previously reported, making them useful for effectively time-resolved measurement of realistic catalytic processes. A data processing technique necessary for the mitigation of interference fringes caused by multiple reflections of the probe beam is also described.

Development of multistage distillation in a microfluidic chip.

Although there has been a lot of work on the development of microchemical processing systems such as micro-reactors and micro-sensors, little attention has been paid to micro-separation units, and in particular, microscale distillation. In this paper, various silicon-glass microscale distillation chips with different channel configurations were fabricated and tested. A temperature gradient was setup across the chip by heating and cooling the two ends. The feed was located at the middle of the microchannel. Arrays of micropillars were incorporated in order to guide the liquid flow. It was found that the separation performance was promoted by increasing the length of the microchannel. However, this created an imbalance of the liquid flows at the two sides of the microchannel and caused flooding. This hydrodynamic limitation was addressed by incorporating micropillars on both sides of the channel. The most efficient microdistillation chip consisted of a microchannel with 600 microns width and 40 cm length. Experimental results showed high efficiency for the separation of a 50 mol% acetone-water mixture when the heating and cooling temperature were 95 °C and 42 °C respectively. The concentrations of acetone were 3 mol% in the bottom stream and 95 mol% in the distillate, which was equivalent to at least 4 equilibrium stages at total reflux conditions. Furthermore, a 50 mol% methanol-toluene mixture was separated into nearly pure toluene in the bottom stream and 75 mol% methanol in the distillate. The performance of the microdistillation unit was reproducible in repeated tests.

The effects of environmental pollution on the respiratory system of children in western Macedonia, Greece.

The indoor and outdoor environmental pollution effects on the respiratory system of 3,559 children aged 9-12 were studied. It was a cross-sectional and interlocal (geographical differentiation) study. The research was conducted during the period between 2000-2001 in five cities of Western Macedonia and more particularly: 1046 children from Ptolemaida, 1249 children from Kozani, 466 from Florina, 419 from Kastoria and 379 from Grevena. The study was performed by means of a questionnaire for the detection of respiratory diseases during childhood, plus spirometry and rhinomanometry measurements. The diachronic quantitative analysis of environmental pollutants was conducted by The Laboratory of Physics of the Atmosphere of the Aristotle University of Thessaloniki. The environmental pollution was found to have a detrimental effect on the respiratory system of children, mainly attributable to the occurrence of rhinitis and infectious bronchitis. The highest prevalence of rhinitis (40.3%) and infectious bronchitis (12.1%) was observed in Ptolemaida, which is a highly polluted region, whereas the lowest (21.2% and 6.7%, respectively) was seen in Grevena, a non-polluted area. As for the indoor pollution, maternal smoking was found to increase the prevalence of respiratory problems in children. Finally, the father's educational level and a past history of nursery school attendance increase the prevalence of respiratory diseases during childhood.

Prevalence of chronic obstructive pulmonary disease and rhinitis in northern Greece.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) constitutes one of the main factors responsible for morbidity and mortality worldwide. Rhinitis has a high prevalence, but its relationship to COPD has not been determined. OBJECTIVES: To estimate the prevalence of COPD and rhinitis in northern Greece and to examine their correlation. PATIENTS AND METHODS: Of a total of 8,151 subjects (aged 21-80 years, from three regions of northern Greece) invited to participate in the study, 6,112 (75%) were included. The regions studied were: (a) Thessaloniki (1,733 study participants, 52.7 +/- 18.6 years old), an urban area with particulate air pollution frequently exceeding the acceptable limit, (b) Eordea (3,537 study participants, 51.4 +/- 15.5 years old), a typical industrial area with particulate air pollution with daily values exceeding the acceptable limit and (c) Grevena (842 study participants, 55.6 +/- 15.4 years old), a mountainous area without pollution. The study participants filled in the questionnaire on respiratory symptoms of the Committee on Environmental and Occupational Health of the Medical Research Council and underwent spirometry and rhinomanometry tests. RESULTS: The prevalence of COPD was 5.6% (8.2% in men and 2.5% in women) and that of rhinitis 24.7% (27.4% in men and 21.4% in women). COPD and rhinitis are related to common predisposing factors (smoking, age and sex). Moreover, rhinitis is related to particulate air pollution levels. CONCLUSIONS: The prevalence of COPD and rhinitis in northern Greece does not differentiate from that found in other industrial countries. A functional relationship between upper and lower airways is speculated.

Comparison of sport achievement orientation of male professional, amateur, and wheelchair basketball athletes.

To examine the differences in sport achievement orientation among 35 professional, 36 amateur, and 35 wheelchair basketball athletes, these men completed three subscales of Competitiveness, Win orientation, and Goal orientation of the 25-item Sport Orientation Questionnaire. A multivariate analysis of variance indicated significant differences among groups. Win orientation was the factor, through discriminant function analysis, that significantly separated the athletes into the three groups. The highest win score was obtained by the professional, followed by the amateur and wheelchair groups. Replication study is necessary to confirm the present findings.