Optical Response of PDMS Surface Diffraction Gratings under Exposure to Volatile Organic Compounds.

Monitoring volatile organic compounds (VOCs) in indoor air is significantly gaining importance due to their adverse effects on human health. Among the diverse detection methods is optical sensing, which employs materials sensitive to the presence of gases in the environment. In this work, we investigate polydimethylsiloxane (PDMS), one of the materials utilized for gas sensing, in a novel transducer: a surface relief diffraction grating.

[A comparative assessment of microbiocenosis of saliva and oropharynx in patients with migraine].

Objective: To identify changes in the microbiome of saliva and to compare it with the microbiome of the oropharynx of patients with migraine.

Material And Methods: Sixty patients with migraine (21-56 years old), were examined using a headache diary, MIDAS and VAS. A microbiological examination of saliva and smear from the mucosa of the posterior wall of the oropharynx with evaluation by the method of mass spectrometry of microbial markers (MSMM) with the determination of 57 microorganisms was performed.

Holographic Recording of Unslanted Volume Transmission Gratings in Acrylamide/Propargyl Acrylate Hydrogel Layers: Towards Nucleic Acids Biosensing.

The role of volume hydrogel holographic gratings as optical transducers in sensor devices for point-of-care applications is increasing due to their ability to be functionalized for achieving enhanced selectivity. The first step in the development of these transducers is the optimization of the holographic recording process. The optimization aims at achieving gratings with reproducible diffraction efficiency, which remains stable after reiterative washings, typically required when working with analytes of a biological nature or several step tests.

Color-Changing Reflection Hologram for Quality Assurance of Therapeutic Ultrasound Systems.

The acoustic output of clinical therapeutic ultrasound equipment requires regular quality assurance (QA) testing to ensure the safety and efficacy of the treatment and that any potentially harmful deviations from the expected output power density are detected as soon as possible. A hologram, consisting of a reflection grating fabricated in an acrylate photopolymer film, has been developed to produce an immediate, visible, and permanent change in the color of the reconstructed hologram from red to green in response to incident ultrasound energy. The influence of the therapeutic ultrasound insonation parameters (exposure time, ultrasound power density, and proximity to the point of maximum acoustic pressure) on the hologram's response has been investigated for two types of therapeutic ultrasound systems: a sonoporation system and an ultrasound physiotherapy system.