Si anodes have attracted considerable attention for their potential application in next-generation lithium-ion batteries because of their high specific capacity (LiSi, 3579 mAh g) and elemental abundance. However, Si anodes have not yet been practically applied in lithium-ion batteries because the volume change associated with lithiation and delithiation degrades their capacity during cycling. Instead of considering the active material, we focused on the structural design and developed a scalable process for producing Si anodes with excellent cycle characteristics while precisely controlling the morphology.
View Article and Find Full Text PDFChemically modified carbon supports for the cathode catalyst layers of polymer electrolyte fuel cells (PEFCs) show considerable promise for boosting the oxygen reduction reaction. This study evaluated the ionomer distribution of Nafion ionomer thin films on nitrogen (N)-modified carbon surfaces along their depth direction. Neutron reflectivity (NR) measurements performed using the double-contrast technique with HO and DO revealed that the introduction of N functional groups to carbon thin films promoted ionomer adsorption onto the surface under wet conditions (22 °C, 85% relative humidity).
View Article and Find Full Text PDFComprehensive analyses were performed using neutron reflectivity and hard X-ray photoelectron spectroscopy to understand the structure and composition of the solid electrolyte interphase (SEI) layer during charge-discharge processes and because of the addition of lithium bis(oxalate)borate (LiBOB) to improve the battery performance. The chemical composition of the SEI was assessed using these methods, and the amount of Li intercalated in the anode during the electrochemical reaction was evaluated. The results demonstrated that LiCO was produced initially but later decomposed to LiCO on the first charge cycle.
View Article and Find Full Text PDFWerner's syndrome (WS) is a genetic disorder presenting with premature senility. In the present study, we performed minimally invasive cardiac surgery (MICS)-aortic valve replacement (AVR) on a patient with Werner's syndrome who presented with aortic stenosis. The patient, a 49-year-old Japanese man, was brought to the emergency room with dyspnea during exercise.
View Article and Find Full Text PDFThe patient was a 31-year-old pregnant woman who gave birth to her first child by vaginal delivery 7 years ago. She was diagnosed with Marfan's syndrome based on physical findings; however, the condition was not diagnosed before the onset. The patient developed acute aortic dissection at 28 weeks of pregnancy.
View Article and Find Full Text PDFHard X-ray photoelectron spectroscopy at multiple photon energies is used to investigate the surface structure of carbon coatings on silicon materials destined for use as negative electrodes in lithium-ion batteries. The photoelectron intensity from the carbon coatings decreases with an increase in the kinetic energy of the photoelectron. By fitting the photoelectron intensity versus energy to numerically derived curves, the thickness and coverage of the carbon coatings can be obtained.
View Article and Find Full Text PDFWe report the first operando measurement of solid electrolyte interphase (SEI) formation at an electrode using in situ neutron reflectometry. The results revealed the growth of the SEI and intercalation of ions during the charge reaction. Furthermore, we propose a way of evaluating the charge used for the SEI formation.
View Article and Find Full Text PDFGen Thorac Cardiovasc Surg
May 2015
Asian Cardiovasc Thorac Ann
December 2013
Kommerell's diverticulum causes compression of the esophagus between the aberrant origin of the left subclavian artery and ascending aorta, leading to dysphagia or dyspnea. We describe 3 cases of successful surgical treatment of right aortic arch with Kommerell's diverticulum and aberrant origin of the left subclavian artery, using a right anterolateral partial sternotomy. This allows both resection of the Kommerell's diverticulum as well as reconstruction of the aberrant origin of the left subclavian artery anatomically.
View Article and Find Full Text PDFSevere aortic stenosis was found by preoperative echocardiography in a 79-year-old female patient with sigmoid colon cancer. Staged operation was planned. First, bioprosthetic aortic valve replacement was performed by minimally invasive cardiac surgery.
View Article and Find Full Text PDFInteract Cardiovasc Thorac Surg
March 2013