Synthesis and Characterization of a Conductive Polymer Blend Based on PEDOT:PSS and Its Electromagnetic Applications.

The purpose of this study is to prepare a resistive lossy material using conducting polymers for electromagnetic wave absorbers. This paper presents a conductive paste largely composed of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) with a polyurethane binder. The various secondary compounds are added in small amounts to an aqueous blended solution in order to enhance the electrical and mechanical properties of the conductive thin film. The synthesized conductive paste is characterized through electrical, chemical, and morphological analyses. The electrical conductivity of the thin film is measured using a four-point probe and surface profiler. The chemical and morphological changes are studied in various experiments using a Raman microscope, X-ray photoelectron spectroscopy, a scanning electron microscope, and an atomic force microscope. In order to verify the applicability of the synthesized conductive paste, which is composed of 70 wt% PEDOT:PSS, 30 wt% polyurethane, and secondary additives (DMAE 0.4 wt%, A-187 0.5 wt%, DMSO 7 wt%, Dynol 604 0.1 wt%, PUR 40 2.5 wt%), the Salisbury screen absorber is fabricated and evaluated in the X-band. According to the results, the absorber resonates at 9.7 GHz, the reflection loss is -38.6 dB, and the 90% absorption bandwidth is 3.4 GHz (8.2 to 11.6 GHz). Through this experiment, the applicability of the PEDOT:PSS-based conductive paste is sufficiently verified and it is found that excellent radar-absorbing performance can be realized.

An Electroactive, Tunable, and Frequency Selective Surface Utilizing Highly Stretchable Dielectric Elastomer Actuators Based on Functionally Antagonistic Aperture Control.

An active, frequency selective surface utilizing a silver-nanowire-coated dielectric elastomer with a butterfly-shaped aperture pattern is realized by properly exploiting the electroactive control of two antagonistic functions (stretching vs compression) on a patterned dielectric elastomer actuator.

Silk fibroin hydrolysate exerts an anti-diabetic effect by increasing pancreatic ß cell mass in C57BL/KsJ-db/db mice.

Components of silk including silk fibroin have long been used as anti-diabetic remedies in oriental medicine. However, detailed mechanisms underlying these antidiabetic effects remain unclear. In this study, we examined the anti-diabetic activity of silk fibroin hydrolysate (SFH) in C57BL/KsJ db/db (db/db) mice, a well-known animal model of non-insulin dependent diabetes mellitus. When the db/db mice were administered SFH in drinking water for 6 weeks, hyperglycemia in the animals gradually disappeared and the level of glycosylated hemoglobin decreased, indicating that SFH plays important role in reducing the symptoms of diabetes. In addition, SFH-treated db/db mice exhibited improved glucose tolerance with increased plasma insulin levels. Immunohistochemical and morphological analyses showed that SFH up-regulated insulin production by increasing pancreatic ß cell mass in the mice. In summary, our results suggest that SFH exerts anti-diabetic effects by increasing pancreatic ß cell mass in a non-insulin dependent diabetes mellitus mouse model.

Erosion of embolization coils and guidewires from the kidney to the colon: delayed complication from coil and guidewire occlusion of renal arteriovenous malformation.

Percutaneous transarterial embolization is a useful, nondrastic, valuable, and commonly used therapeutic option for the treatment of renal arteriovenous malformation (AVM). Compared with partial or total nephrectomy, transarterial embolization is more conservative and preserves renal function. However, it has some limitations and complications that could cause renal infarction and progression of hypertension, renal insufficiency, and pulmonary embolism. Large-sized AVM and multiplicity of abnormal vessels also limit the use of the embolization technique. The authors experienced erosion of the coils and guidewires that were used for embolization of renal AVM from kidney to descending colon. Coil embolization is practiced extensively, but a complication such as this does not appear to have been described.