background: hairdressers are occupationally exposed to a number of agents in their workplace that result in respiratory symptoms and changes in pulmonary function. objective: to evaluate associations between occupational exposure and respiratory function and reported symptoms in a group of hairdressers compared to a control group. methods: a questionnaire on respiratory symptoms and workplace c...

this study aimed to examine the effectiveness of combined microwave-ultrasonic pasteurization system on escherichia coli and vitamin c content in sour cherry juice (scj). based on the findings, microwave output power, ultrasound power, and ultrasonic exposure time as well as the microwave-induced temperature were the most effective factors in reducing e. coli and vitamin c content. in addition,...

background  & aim: case-crossover  studies are the case-control  version of crossover studies. in these studies, cases and controls are the same subjects. the term crossover is applied for designs that all subjects pass through both treatment (exposure) and placebo (non-exposure) phases. in fact they are  crossover  of  subjects  between  periods  of  exposure  and  non-exposure.  this  design ...