Topology optimization of a waveguide acoustic black hole for enhanced wave focusing.

The waveguide acoustic black hole (WAB) effect is a promising approach for controlling wave propagation in various applications, especially for attenuating sound waves. While the wave-focusing effect of structural acoustic black holes has found widespread applications, the classical ribbed design of waveguide acoustic black holes (WABs) acts more as a resonance absorber than a true wave-focusing device. In this study, we employ a computational design optimization approach to achieve a conceptual design of a WAB with enhanced wave-focusing properties.

How the waveguide acoustic black hole works: A study of possible damping mechanisms.

The acoustic black hole (ABH) effect in waveguides is studied using frequency-domain finite element simulations of a cylindrical waveguide with an embedded ABH termination composed of retarding rings. This design is adopted from an experimental study in the literature, which surprisingly showed, contrary to the structural counterpart, that the addition of damping material to the end of the waveguide does not significantly reduce the reflection coefficient any further. To investigate this unexpected behavior, we model different damping mechanisms involved in the attenuation of sound waves in this setup.

Tumor Therapy with Novel Immunotoxin Containing Programmed Cell Death Protein-1 and Diphtheria Toxin.

Immunotoxins, as a class of antitumor agents, consist of tumor-selective ligands linked to highly toxic protein molecules. This type of modified antibody has been designed for the therapy of cancers and a few viral infections. In this study, we designed immunotoxin consisting of mouse programmed cell death protein-1 (PD1), which genetically fused to diphtheria toxin (DT) subunit A (DT386).

Developing hyaluronic acid microgels for sustained delivery of platelet lysate for tissue engineering applications.

Platelet lysate (PL), a blood product that contains high concentrations of growth factors (GFs), can be considered as a cost-effective source of multiple GFs. In this study, hyaluronic acid (HA) based microgels were developed for delivery of PL proteins. Spherical microgel were prepared using a water in oil emulsion method.

An injectable platelet lysate-hyaluronic acid hydrogel supports cellular activities and induces chondrogenesis of encapsulated mesenchymal stem cells.

Developing scaffolds that can provide cells and biological cues simultaneously in the defect site is of interest in tissue engineering field. In this study, platelet lysate (PL) as an autologous and inexpensive source of growth factors was incorporated into a cell-laden injectable hyaluronic acid-tyramine (HA-TA) hydrogel. Subsequently, the effect of platelet lysate on cell attachment, viability and differentiation of human mesenchymal stem cell (hMSCs) toward chondrocytes was investigated.

Development and adaptation of Iranian youth reproductive health questionnaire.

Iran is a young country, and sexual behavior is shaped in this period. This research aimed to provide an assessment tool to evaluate Iranian youth reproductive health. This multistage research was conducted to design a valid questionnaire in the domains of knowledge, attitude, and behavior of the youth in order to evaluate behavior change programs.