Anisotropic Adhesion of Micropillars with Spatula Pads

Natural gecko adhesive structures consisting of angled setae, branched into thin spatulas, have remarkable properties including easily attachable and releasable anisotropic adhesion. The geometrically asymmetric structures lead to anisotropic adhesive properties. Inspired by the gecko, we fabricated an array of micropillars with asymmetric spatula pads from elastomeric materials. This paper describes the anisotropic properties of the micropillars with spatula pads as established by experimental measurements and observation together with finite element analysis. The results indicate that the structural difference of the spatula pad at one edge of the micropillar provides the anisotropic adhesive properties

Nanosized Ultrasound Enhanced-Contrast Agent for in Vivo Tumor Imaging via Intravenous Injection

To enhance the detection limit of ultrasound (US) imaging, ultrasound enhanced-contrast agents (UECAs) that can go preferentially to the target tissue such as a tumor and amplify the US signal have been developed. However, nanosized UECAs among various UECAs developed are very limited to clearly demonstrate proper ability for selective tumor detection by US imaging upon their intravenous injection. In this study, we prepared CaCO₃ nanoparticles that were formed inside a flexible and biocompatible pluronic-based nanocarrier. This nanosized UECA was stable in serum-containing media and generated CO₂, more preferentially at low pH; thus, it could be detected by US imaging. After intravenous injection into tumor-bearing mice, this nanosized UECA showed a significant US contrast enhancement at the tumor site in 1 h, in contrast to no change in the liver, followed by a rapid clearance from the body in 24 h. Therefore, the present nanosized UECA could be applied as an effective diagnostic modality for in vivo tumor imaging by ultrasonography

Poly-adenine-Coupled LAMP Barcoding to Detect <i>Apple Scar Skin Viroid</i>

<i>Apple Scar Skin Viroid</i> (ASSVd), a nonprotein coding, circular RNA pathogen is relatively difficult to detect by immunoassay. We report here a one-step reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay to improve selectivity for diagnostic use in detecting ASSVd in plants. ASSVd RT-LAMP was accelerated using loop primers and was found to be highly sensitive with a detection limit of 10⁴ copies of cDNA-ASSVd within 30 min. Real-time LAMP and melting curve analysis could differentiate between the true-positive LAMP amplicons and false-positive nonspecific primer amplification products. The optimized RT-LAMP was then followed by the addition of nonthiolated AuNP:poly-adenine (A10)-ASSVd LAMP barcodes, showing a high authentication capacity with colorimetric changes. This type of barcoding assay is a potential alternative for rapid and multiple viroid diagnosis, providing for visible sensing in the field that can be applied to viroid-free planting

Heterologous Production of 4‑<i>O</i>‑Demethylbarbamide, a Marine Cyanobacterial Natural Product

Heterologous expression of the barbamide biosynthetic gene cluster, obtained from the marine cyanobacterium <i>Moorea producens</i>, in the terrestrial actinobacterium <i>Streptomyces venezuelae</i>, resulted in the production of a new barbamide congener 4-<i>O</i>-demethylbarbamide, demonstrating the potential of this approach for investigating the assembly and tailoring of complex marine natural products