1000 hertz exposure

INTRODUCTION: The consequence of an exposure to intense sounds can be a temporary or permanent hearing loss and even with a rapid therapeutic management, severe sensorineural sequelae may persist. METHODS: the authors report a retrospective study about 64 patients followed for an acute acoustic trauma during a period of 8 years (2006 to 2013). For all the cases, a clinical examination associated to a pure-tone audiometry was conducted. Hearing levels were measured at the frequencies 500, 1000, 2000 and 3000 Hertz...

BACKGROUND: Gene-environment interactions have been investigated for diseases such as asthma, chronic obstructive pulmonary disease, cancer etc. but acute disease like bronchitis has rarely been studied. We investigated interactions between air pollution (polycyclic aromatic hydrocarbons (PAH) and particulate matter <2.5 μm (PM2.5)) and single nucleotide polymorphisms (SNP) in EPHX1, IL10, STAT4 and XPC genes in relation to bronchitis in children aged 0-2 years. METHODS: A stratified random sample of 1133 Czech children, born between 1994 and 1998 in two districts, were followed since birth, of which 626 were genotyped...

This study determined the body burden of PBDEs in 100 California children, and evaluated associations with sociodemographic, household, and dietary factors. In national and international comparisons, California dust, breast milk, and human serum samples contain higher concentrations of PBDEs. Higher levels in children suggest exposure pathways depend upon age. Plasma samples were analyzed for PBDEs using GC/MS. Circulating levels of PBDEs were 10-to 1000-fold higher than similar aged populations in Mexico and Europe, 5-times higher than similar aged children across the U...

OBJECTIVES: To measure the prevalence of hearing aid use among older adults with hearing loss and to identify factors associated with those currently using hearing aids. DESIGN: Population-based cohort study. SETTING: The south-central Wisconsin community of Beaver Dam. PARTICIPANTS: A total of 1629 adults, aged 48 to 92 years, who have hearing loss and are participating in the Epidemiology of Hearing Loss Study and the Beaver Dam Eye Study...

The effects of misoprostol, a prostaglandin E1 analog, and prostaglandin E2 on proteoglycan biosynthesis and loss were studied in unloaded and mechanically loaded mature bovine articular cartilage explants. The prostaglandins were administered daily at dosages of 0, 10, 100 and 1000 eta g/ml for up to seven days, and proteoglycan biosynthesis determined by measurement of radiolabelled sulfate incorporation. The presence of misoprostol lead to a significant (p < 0.001) dose-dependent inhibition (30%-50%) in proteoglycan biosynthesis which was also dependent on exposure time (p < 0...

Tissue effects of the mid-IR Holmium laser (emitting at a wave-length of 2130 nm) were evaluated. This wavelength is attractive because it combines high water absorption and easy transmission through standard optical fibres. The laser was pulsed with pulse durations in the range of 100 microseconds and repetition rates between 2 and 6 Hertz. For all experiments a repetition rate of 2 Hertz was used. The laser beam was coupled into waterfree quartz fibers with core diameters of 200 and 800 microns with an efficiency of 70 and 80%, respectively...