Synthesis and Characteristic Valuation of a Thermoplastic Polyurethane Electrode Binder for In-Mold Coating.

A polyurethane series (PHEI-PU) was prepared via a one-shot bulk polymerization method using hexamethylene diisocyanate (HDI), polycarbonate diol (PCD), and isosorbide derivatives (ISBD) as chain extenders. The mechanical properties were evaluated using a universal testing machine (UTM), and the thermal properties were evaluated using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The PHEI-PU series exhibited excellent mechanical properties with an average tensile strength of 44.71 MPa and an elongation at break of 190%. To verify the applicability of different proportions of PU as an electrode binder, PU and Ag flakes were mixed (30/70 wt%) and coated on PCT substrates, the electrodes were evaluated by four-point probe before and after 50% elongation, and the dispersion was evaluated by scanning electron microscopy (SEM). The electrical resistance change rate of PHEI-PU series was less than 20%, and a coating layer with well-dispersed silver flakes was confirmed even after stretching. Therefore, it exhibited excellent physical properties, heat resistance, and electrical resistance change rate, confirming its applicability as an electrode binder for in-mold coating.

Giant Brunner's Gland Adenoma of the Proximal Jejunum Presenting as Iron Deficiency Anemia and Mimicking Intussusceptions

Brunner's gland adenoma is a rare benign proliferative lesion developing most commonly in the posterior wall of the duodenum. It is usually small in size and asymptomatic. Depending on its size or location, however, the clinical manifestations of this tumor may be variable from nonspecific symptoms to gastrointestinal bleeding or obstruction. Brunner's gland adenoma in the proximal jejunum is extremely rare. We report a very rare case of giant Brunner's gland adenoma developing in the proximal jejunum which presented as iron deficiency anemia and mimicked intussusceptions on radiologic studies.

Usefulness of Stent Implantation for Treatment of Intracranial Atherosclerotic Stenoses / 신경중재치료의학

PURPOSE: We evaluated the usefulness of intracranial stent implantation for treating patients with atherosclerotic stenosis and with recurrent, ischemic, neurological symptoms despite having undergone medical therapy. MATERIALS AND METHODS: Between March 2004 and April 2010, we attempted intracranial, stent-assisted angioplasty in 77 patients with 85 lesions (anterior circulation 73 cases, posterior circulation 12 cases) and who had ischemic neurological symptoms with more than 50% major cerebral artery stenosis. We analyzed the results regarding the technical success rate, complication rate, and restenosis rate during the mean 29.4 month follow-up period. RESULTS: Intracranial stent implantation was successfully performed in 74 cases (87.1%). In nine cases among the 11, failed cases, stent implantation failure was due to the tortuosity of the target vessel. One patient experienced middle cerebral artery rupture during the procedure, and we embolized the vessel using a microcoil. Five patients developed cerebral infarction in three weeks after the procedure, three of whom improved using conservative management, although the other, two patients expired. The mean number of residual stenoses decreased from 72.3% to 14.7%. Three patients demonstrated significant in-stent restenosis, i.e. more than 50%, during the follow-up period. CONCLUSION: As stent-assisted angioplasty in intracranial, atherosclerotic stenosis is effective and relatively safe, it can be considered as an alternative treatment for patients with recurrent, ischemic, neurologic symptoms despite having undergone medical therapy.