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Staphylococcus aureus is one of the main causative bacteria for polyurethane catheter and artificial graft infection. Recently, we developed a unique technique for coating diamond-like carbon (DLC) inside the luminal resin structure of polyurethane tubes. This study aimed to elucidate the infection-preventing effects of diamond-like carbon (DLC) coating on a polyurethane surface against S. aureus. We applied DLC to polyurethane tubes and rolled polyurethane sheets with our newly developed DLC coating technique for resin tubes. The DLC-coated and uncoated polyurethane surfaces were tested in smoothness, hydrophilicity, zeta-potential, and anti-bacterial properties against S. aureus (biofilm formation and bacterial attachment) by contact with bacterial fluids under static and flow conditions. The DLC-coated polyurethane surface was significantly smoother, more hydrophilic, and had a more negative zeta-potential than did the uncoated polyurethane surface. Upon exposure to bacterial fluid under both static and flow conditions, DLC-coated polyurethane exhibited significantly less biofilm formation than uncoated polyurethane, based on absorbance measurements. In addition, the adherence of S. aureus was significantly lower for DLC-coated polyurethane than for uncoated polyurethane under both conditions, based on scanning electron microscopy. These results show that applying DLC coating to the luminal resin of polyurethane tubes may impart antimicrobial effects against S. aureus to implantable medical polyurethane devices, such as vascular grafts and central venous catheters.

We repot a case of type A aortic dissection after thoracic endovascular aortic repair (TEVAR) for type B aortic dissection. A 70-year-old man underwent TEVAR for type B aortic dissection. Seven months after TEVAR, follow-up computed tomography revealed type A aortic dissection. We urgently performed total arch replacement with open stent graft. Although TEVAR is currently recommended as the 1st-line treatment for complicated type B aortic dissection with malperfusion or dilatation, retrograde type A aortic dissection might occur as a rare but life-threatening complication. Fragility of the aortic wall and disease progression combined with stent grafting-related injury contribute to its occurrence. Open stent graft technique is useful in such a case.

100V aluminum electrolytic capacitors with high performance are strongly demanded from the market. Silica or aluminosilicate ethylene glycol sols in combination with three kinds of organo-phosphorous acids were added into a quaternary alkylammonium salt-based electrolyte solution to increase its sustaining voltage while keeping its high electrolytic conductivity and high thermal stability. In addition to the ordinary life evaluation test, investigation of initial electric properties and assessment for sustaining voltage of capacitors using those electrolyte solutions during dc-load life tests at 378K were performed. Consequently, we observed that the combination between aluminosilicate ethylene glycol sol and dibutyl phosphate gives the most promising performance. The capacitors using the optimized electrolyte afforded less than one-half ESR at 233K and more than twice the durability compared with those using a conventional electrolyte solution. These results demonstrate the possibility to apply quaternary ammonium salt-based electrolyte solutions for 100V aluminum electrolytic capacitors.

The sustaining voltage of aluminum electrolytic capacitors can be enhanced by the addition of colloidal silica into their operating nonaqueous electrolyte solutions. A systematic study on the effects of colloidal silica on the scintillation voltage of aluminum electrolytic capacitors was carried out using silica organo-sols dispersed in ethylene glycol and quaternary ammonium carboxylate/γ-butyrolactone solutions. It was confirmed that maintaining the dispersed state of nano-particles in electrolytes so as not to cause gelation is the prime requirement as a sustaining voltage booster. The synergetic effect of organo-phosphorous acids was also examined.

Kommerell diverticulum (KD) with left aberrant subclavian artery is a rare congenital variation of vascular structure, and it can be asymptomatic or symptomatic owing to mass effect. Surgical intervention is recommended in symptomatic patients or asymptomatic patients with a large diverticulum because of possible dissection and rupture of Kommerell diverticulum. We report a case of right-sided aorta, KD, and left aberrant subclavian artery in a 74- year-old man. He had no symptoms with KD.