a label-free electrochemical nucleic acid aptasensor for the detection of methamphetamine (ma) by the immobilization of thiolated self-assembled dna sequences on a gold nanoparticles-chitosan modified electrode is constructed. when ma was complexed specifically to the aptamer, the configuration of the nucleic acid aptamer switched to a locked structure and the interface of the biosensor changed...

BACKGROUND The aim of the study was to answer the question of whether earplugs provide sufficient protection in the exposure to impulse noise generated during metalworking processes. MATERIAL AND METHODS The noise generated by die forging hammer and punching machine was characterized. Using an acoustic test fixture, noise parameters (LCpeak, LAmax) under 24 earplugs, foam, winged and no-roll,...

We present preliminary results concerning amplitude saturation in β Cephei models. Using nonlinear approach we have investigated amplitude limitation mechanism in β Cephei stars. In our approach radial modes have been treated as representative for all acoustic oscillations. We have studied pulsation properties of several models (7–20 M ⊙ , Z = 0.02, 0.015) using radiative Lagrangean hydrocodes ...

The occupational exposure limit for acrylonitrile (AN) has been set by many organizations on the basis of its carcinogenicity. However, recent epidemiological studies do not afford evidence supporting the hypothesis that AN is carcinogenic to humans. Review of the 18 published cohort studies revealed that, although there is not adequate evidence in humans for carcinogenicity of AN, the possibil...

The aim of this review was to assess current knowledge related to the occupational exposure limit (OEL) for fluid aerosols including either mineral or chemical oil that are generated in metalworking operations, and to discuss whether their OEL can be appropriately used to prevent several health risks that may vary among metalworking fluid (MWF) types. The OEL (time-weighted average; 5 mg/m(3), ...

Abstract Objective To estimate the prevalence of hand-arm vibration (HAV) in Australian workplaces. Methods The Workplace Exposure Survey (AWES)—Hearing was a cross-sectional telephone survey workers conducted 2016–2017. Respondents were asked about time spent using tools or performing tasks known to be associated with HAV during their most recent working day. We created library magnitude level...

introduction: nickel (ni) is one of the toxic heavy metals that exposure to it has been connected with chronic respiratory complications such as asthma, chronic bronchitis, lung cancer and heart disease. in this research, original studies that investigated occupational or environmental exposure to nickel and  measured nickel levels in human tissues were reviewed. materials and methods: in this ...

glutaraldehyde is commonly used in endoscopy labs to clean and disinfect instruments. it can cause direct irritation of the skin and the upper and lower airways. health care workers are also at risk for the development of irritant-induced or sensitizer-induced occupational asthma when exposed to this chemical. herein, we report on a patient who had frequent exposures to glutaraldehyde over one ...

in this research, air sampling of workplaces was carried out by two methods (long - time and short - time). the mean formaldehyde concentration with long - time method in pathology labs, surgery and endoscopy sections were 0.96 0.25 and 0.13 ppm and with short - time method, 8 hours, was 3, 0.3 and 0.2 ppm. the mean formaldehyde concentration in pathology labs was above the standard values (tlv...