The effect of bariatric-metabolic surgery on selected components of metabolic syndrome and visceral adipose tissue - the pilot study.

The aim of this study was to monitor changes in the components of the metabolic syndrome defined by Adult Treatment Panel III and the risk of adipose tissue. The study population consisted of 45 patients (30 women, 15 men) who underwent one bariatric procedure - partial jejuno-ileal derivation (n=17), sleeve resection (n=14) or laparoscopic gastric - plication (n=14). Components of metabolic syndrome such as waist circumference, morning glycemia/antihypertension, TAG, HDL cholesterol and blood pressure (BP)/antihypertension were monitored in probands. In addition, Dual Energy X-Ray Absorciometry measurements were performed. Parameters were monitored over the course of one year. The study shows that it is an effective method of weight reduction for the study population with metabolic effects in the risk components of metabolic syndrome - fasting glycemia, increase in HDL cholesterol and reduction in triacylglycerols in the blood, reduction in waist circumference and BP or direct disappearance of metabolic syndrome. Significantly, of the entire cohort, 68.9 % of the probands studied showed signs of metabolic syndrome when measured before the intervention. At the end of follow-up, only 22.2 % of probands showed metabolic syndrome. It was also found that if the amount of visceral fat was reduced, the overall risk of metabolic syndrome was also reduced. The study demonstrates a significant positive effect of bariatric surgery on parameters of metabolic syndrome. The study also showed a positive effect of reduced visceral fat volume on the components of metabolic syndrome.

Dispersion of light and heavy pollutants in urban scale models: CO(2) laser photoacoustic studies.

The distribution of pollutants in two urban scale models (point emission source and street canyon with extensive transport) was investigated by means of CO(2) laser photoacoustic spectroscopy in the region of the atmospheric window (9-10 mum). The experimental results of physical modeling are in a good agreement with the numerical calculations performed in the frame of computational fluid dynamic (CFD) modeling. Methanol, ethanol, and ozone (examples of light pollutants), as well as sulfur hexafluoride and 1,2 dichlorethane (examples of heavy pollutants), were selected on the basis of their high resolution spectra acquired by Fourier transform and laser diode spectroscopy.

GaSb based lasers operating near 2.3 microm for high resolution absorption spectroscopy.

The paper describes results obtained with a new type of GaSb based semiconductor distributed feedback multiple quantum well lasers operating in continuous wave mode well above room temperature. The lasers show good tunability both by current and temperature from 0 to +60 degrees C and current from threshold up to 120 mA. They all operate in high power (1-3 mW) single mode regime and can be tuned in the methane and ammonia overtone absorption spectral range over up to 12 cm(-1) and can be used for the detection of these and other gases.

Laser diode photoacoustic detection in the infrared and near infrared spectral ranges.

A new technique for high resolution photoacoustic detection based on application of laser diodes has been developed. This method was tested and compared using identical photoacoustic instrumentation (cell and microphone) to study gas absorption in three different spectral regions, namely: the infrared range near 2100 cm(-1), CO and OCS fundamental band absorption; the ranges near 4200 and 4350 cm(-1), CH4, NH3 and N2O overtone and combination band absorption; the near infrared range near 6500 cm(-1), CO, CO2 and NH3 overtone absorption. Several types of diode laser operating at room temperature or at liquid nitrogen temperature were compared. The optimum gas pressures for the maximum sensitivity of the photoacoustic signals were found and the detection limits were estimated for all of the gases studied. The best sensitivity was achieved for NH3 at 100 ppbv. The sensitivity of the developed system was tested on detection of traces of NH3 and CO2 gases from car exhaust.