Reduced dimer production in solar-simulator-pumped continuous wave iodine lasers based on model simulations and scaling and pumping studies

A numerical rate equation model for a continuous wave iodine laser with longitudinally flowing gaseous lasant is validated by approximating two experiments that compare the perfluoroalkyl iodine lasants n-C3F7I and t-C4F9I. The salient feature of the simulations is that the production rate of the dimer (C4F9)2 is reduced by one order of magnitude relative to the dimer (C3F7)2. The model is then used to investigate the kinetic effects of this reduced dimer production, especially how it improves output power. Related parametric and scaling studies are also presented. When dimer production is reduced, more monomer radicals (t-C4F9) are available to combine with iodine ions, thus enhancing depletion of the laser lower level and reducing buildup of the principal quencher, molecular iodine. Fewer iodine molecules result in fewer downward transitions from quenching and more transitions from stimulated emission of lasing photons. Enhanced depletion of the lower level reduces the absorption of lasing photons. The combined result is more lasing photons and proportionally increased output power

Immunologic status of agricultural workers in the region of Lombardy, Northern Italy

Purpose. Farming is associated with a wide variety of hazardous exposures including physical, chemicals and biological agents. Animal farmers are exposed to dust which contains microorganisms, mycotoxins, endotoxins, animal feed particles, allergens and chemical agents. Organic dust exposure is known to cause allergic and non-allergic rhinitis, and organic dust toxic syndrome. This study was undertaken to evaluate the relationship between occupational health hazards and serum pro-inflammatory cytokines among agricultural workers, in particular we investigated whether animal breeders react differently to biological agents than non breeder farmers. Methods. One hundred subjects working in agricultural enterprises in the region of Lombardy, were enrolled into the study in 2010. Serum cytokines including interleukin (IL)-6, IL-8, IL-10, IFN\u3b3 and tumor necrosis factor-\u3b1 (TNF\u3b1) were measured. Cytokines were assessed by commercially available enzyme-linked-immunosorbent assay (ELISA). Results of the study. Compared to control subjects, increased TNF-\u3b1, IL-8, and IL-10 levels were found in animal breeders, and a statistically significant relationship between type of job (breeder/non breeder workers) and increased serum pro-inflammatory cytokines. Results suggest that animal breeders might be at higher risk of occupational diseases and biological hazards than other farmers with less contact to animals

Occupational exposure to biohazards and endotoxins among agricultural workers in the region of Lombardy, Northern Italy

Purpose. Farming is associated with a wide variety of hazardous exposures including physical, chemicals and biological agents. Animal farmers are exposed to dust, which contains microorganisms, mycotoxins, endotoxins, animal feed particles, allergens and chemical agents. Organic dust exposure is known to cause allergic and non-allergic rhinitis, and organic dust toxic syndrome. Measurements of serum cytokine levels have been performed as biomarkers and strong predictors of diseases in many epidemiologic studies. This study was undertaken to evaluate the relationship between occupational health hazards and serum pro-inflammatory cytokines among agricultural workers in north of Italy. Methods. A pilot study was conducted in 2010 and One hundred subjects working in agricultural enterprises in the region of Lombardy were enrolled into the study. Serum cytokines including interleukin IL-6, IL-8, IL-10, IFN gamma and tumor necrosis factor alpha were measured. Cytokines were assessed by commercially available enzyme-linked-immunosorbent assay (ELISA). Results of the study. Compared to control subjects, increased TNF-alpha, IL-8 and IL-10 levels were found in animal breeders, with a statistically significant relationship between type of job (breeder/non breeder workers) and increased serum pro-inflammatory cytokines. Results suggest that animal breeders might be at higher risk of biological hazards than other farmers with less contact to animals. Blood cytokine assay may also be useful to identify individual responsiveness to endotoxins at work place. The relationship between exposure to organic dust, microorganisms, endotoxins and other chemicals in the work place and disease needs further research