Preparation of a Crosslinked Poly(imide-siloxane) for Application to Transistor Insulation.

Insulated gate bipolar transistor (IGBT) is an important power device for the conversion, control, and transmission of semiconductor power, and is used in various industrial fields. The IGBT module currently uses silicone gel as an insulating layer. Since higher power density and more severe temperature applications have become the trend according to the development of electronic device industry, insulating materials with improved heat resistance and insulation performances should be developed.

Transparent Self-Cleaning Coatings Based on Colorless Polyimide/Silica Sol Nanocomposite.

We herein report transparent self-cleaning coatings based on polyimide-fluorinated silica sol (PIFSS) nanocomposite. Polyamic acid-silica sol (PASS) suspensions were synthesized by adding four different amounts of a silica sol suspension to each end-capped polyamic acid solution. The PASS suspensions were spin-coated on glass slides, thermally imidized and treated with triethoxy-1,1,2,2-perfluorodecylsilane (TEFDS) to prepare PIFSS coatings.

Flexible Transparent Electrode Characteristics of Graphene Oxide/Cysteamine/AgNP/AgNW Structure.

Graphene oxide (GO)-cysteamine-Ag nanoparticles (GCA)-silver nanowire (AgNW) fabricated by depositing GCA over sprayed AgNWs on PET films were proposed for transparent and flexible electrodes, and their optical, electrical, and mechanical properties were analyzed by energy-dispersive X-ray spectroscopy, Fourier-transform infrared spectroscopy, Raman spectroscopy, atomic force microscopy, scanning electron microscopy, transmission electron microscopy, current-voltage measurements, and bending test. GCA-AgNW electrodes show optical transmittance of >80% at 550 nm and exhibit a high figure-of-merit value of up to 116.13 in the samples with sheet resistances of 20-40 Ω/◻.

Polyimide-Based PolyHIPEs Prepared via Pickering High Internal Phase Emulsions.

Pyromellitic dianhydride (PMDA) and 4,4'-oxydianiline (ODA) oligoimide particles and PMDA-ODA poly(amic acid) salt (PAAS) were synthesized and used as stabilizers to prepare oil-in-water Pickering high internal phase emulsions (HIPEs). The stability of the Pickering HIPEs was investigated by dispersion stability analysis. Polyimide-based polyHIPEs could be prepared through freeze-drying and subsequent thermal imidization of the Pickering HIPEs.

An Oligoimide Particle as a Pickering Emulsion Stabilizer.

A pyromellitic dianhydride (PMDA) and 4,4'-oxydianiline (ODA)-based oligoimide (PMDA-ODA) was synthesized by a one-step procedure using water as a solvent. The PMDA-ODA particles showed excellent partial wetting properties and were stably dispersed in both water and oil phases. A stable dispersion was not obtained with comparison PMDA-ODA particles that were synthesized by a conventional two-step method using an organic solvent.

Preparation of Polyimide/Graphene Oxide Nanocomposite and Its Application to Nonvolatile Resistive Memory Device.

2,6-Diaminoanthracene (AnDA)-functionalized graphene oxide (GO) (AnDA-GO) was prepared and used to synthesize a graphene oxide-based polyimide (PI-GO) by the in-situ polymerization method. A PI-GO nanocomposite thin film was prepared and characterized by infrared (IR) spectroscopy, thermogravimetric analysis (TGA) and UV-visible spectroscopy. The PI-GO film was used as a memory layer in the fabrication of a resistive random access memory (RRAM) device with aluminum (Al) top and indium tin oxide (ITO) bottom electrodes.

Enhancement of the Mechanical Properties of Polyimide Film by Microwave Irradiation.

Polyimide films have conventionally been prepared by thermal imidization of poly(amic acid)s (PAAs). Here we report that the improvement of tensile strength while increasing (or maintaining) film flexibility of polyimide films was accomplished by simple microwave (MW) irradiation of the PAAs. This improvement in mechanical properties can be attributed to the increase in molecular weight of the polyimides by MW irradiation.

Low-Temperature Self-Healing of a Microcapsule-Type Protective Coating.

Low-temperature self-healing capabilities are essential for self-healing materials exposed to cold environments. Although low-temperature self-healing concepts have been proposed, there has been no report of a microcapsule-type low-temperature self-healing system wherein the healing ability was demonstrated at low temperature. In this work, low-temperature self-healing of a microcapsule-type protective coating was demonstrated.

Trifolin induces apoptosis via extrinsic and intrinsic pathways in the NCI-H460 human non-small cell lung-cancer cell line.

Background: Trifolin (kaempferol-3-O-galactoside), which is a galactose-conjugated flavonol, exhibits antifungal and anticancer effects. However, the mechanisms underlying its anticancer activities have not yet been examined.

Purpose: In this study, the anticancer effects of trifolin were examined in human lung cancer cells.

Complete atrioventricular block-induced Torsade de pointes, manifested by epilepsy.

Complete atrioventricular (AV) block is frequently regarded as a cause of informed syncopal attacks, even though the escape rhythm is maintained. Torsade de pointes (TdP) may be a significant complication of AV block associated with QT prolongation. Here, we report the case of a 42-year-old female who was referred to our hospital due to recurrent seizure-like attacks while taking anti-convulsant drugs at a psychiatric hospital.

The significance of repetitive ventricular responses induced by radiofrequency energy application for idiopathic left ventricular tachycardia.

In radiofrequency (RF) ablation for idiopathic left ventricular tachycardia (ILVT), the termination of tachycardia during RF ablation is considered a hallmark of success. However, in cases of patients with difficulty of induction of ventricular tachycardia (VT), the evaluation of procedural success can be problematic. We have observed thermal responses reflected as ventricular rhythm change to RF energy delivered on sinus rhythm for ILVT.

Effects of combined therapy with ezetimibe plus simvastatin after drug-eluting stent implantation in a porcine coronary restenosis model.

The aim of this study was to examine the anti-proliferative and anti-inflammatory effects of ezetimibe/simvastatin (E/S) after drug-eluting stent (DES) implantation in a porcine coronary restenosis model. Pigs were randomized into two groups in which the coronary arteries (23 pigs) had DES. Stents were deployed with oversizing (stent/artery ratio 1.

Complete fracture of sirolimus-eluting stent in a saphenous vein graft to left anterior descending artery.

Coronary stent fractures have been suggested as a potential new mechanism of restenosis. The mechanical properties of stents were designed not only to prevent vessel recoil, but also to resist the mechanical stress of vessel movement over millions of cardiac cycles. We present a case in which mechanical stress may have contributed to the fracture of a stent implanted in a saphenous vein graft (SVG) to the left coronary artery.

Successful radiofrequency catheter ablation for wolff-Parkinson-white syndrome within the neck of a coronary sinus diverticulum.

Posteroseptal accessory pathways are often associated with coronary sinus diverticula. These diverticula contain myocardial coats which serve as a bypass tract. We report a 54-year-old woman who underwent radiofrequency (RF) catheter ablation for Wolff-Parkinson-White (WPW) syndrome.

Acute changes in cardiac synchrony and output according to RV pacing sites in Koreans with normal cardiac function.

Introduction: The synchrony of the pacing heart can be affected by the right ventricular (RV) pacing site and is crucial to cardiac function in pacemaker recipients. We evaluated the acute changes in cardiac synchrony according to the RV pacing sites in normal systolic functioning subjects with normal QRS.

Methods: We conducted this study with 30 patients with the pacing in the RV apex (RVA), RV septum (RVS), and RV outflow tract (RVOT) in a sequential manner.

A case of congenital bilateral coronary-to-right ventricle fistula coexisting with variant angina.

A coronary arteriovenous (AV) fistula consists of a communication between a coronary artery and a cardiac chamber, a great artery or the vena cava. It is the most common anomaly that can affect coronary perfusion. Yet bilateral involvement of a coronary fistula, constitutes an uncommon subgroup of coronary AV fistulas.

Hemorrhagic pericarditis with cardiac tamponade after percutaneous coronary intervention associated with the use of abciximab.

Glycoprotein (GP) IIb/IIIa inhibitors, such as abciximab, are used as adjunctive therapy for percutaneous coronary intervention (PCI) in high-risk non-ST-elevation myocardial infarction (NSTEMI) and in ST-elevation myocardial infarction (STEMI), although their effects when used for STEMI are less clear. As the use of GP IIb/IIIa inhibitors becomes more widespread, determining the risks associated with them becomes more important. The major risks associated with the use of GP IIb/IIIa inhibitors are the potential for major bleeding and thrombocytopenia.

Adenosine Tc-99m tetrofosmin SPECT in differentiation of ischemic from nonischemic cardiomyopathy in patients with LV systolic dysfunction.

Background: The noninvasive differentiation of ischemic from nonischemic cardiomyopathy is clinically important. However, whether adenosine Tc-99m tetrofosmin SPECT can offer clear and accurate information was not known. The aim of this study is to investigate the usefulness of adenosine Tc-99m tetrofosmin SPECT in differentiation of ischemic from nonischemic etiology in patients with mild to severe LV systolic dysfunction and to compare the relationship between patients with mild LV systolic dysfunction and those with severe LV systolic dysfunction.

The association between current Helicobacter pylori infection and coronary artery disease.

Background: The role of Helicobacter pylori (H. pylori) in the pathogenesis of coronary artery disease (CAD) is still controversial, and the relation between current H. pylori infection and CAD has not been fully examined.

Digitized QT dispersion by the Valsalva maneuver in hypertensive patients.

Background: Hypertension is an important risk factor for sudden cardiac death, of which the incidence increases with increases in blood pressure. Prolonged QT dispersion has been identified to indicate increased risk of life-threatening ventricular arrhythmia and sudden cardiac death. In this study, QT dispersion was investigated in hypertensive patients during the strain phase of the Valsalva maneuver.

Aspergillus infection in a large thrombus of a permanent ventricular pacing lead.

Pacemaker lead infection is a rare but a dangerous complication. Diagnosis can usually be established by the clinical picture and blood cultures. Transesophageal two dimensional echocardiography might be crucial in the diagnosis by visualizing pacing lead vegetations.