Publications by authors named "Hiroyuki Kawaura"

Article Synopsis
  • In Japan, doctor cars are specialized emergency medical vehicles staffed by physicians, designed to provide advanced trauma care before patients reach the hospital.
  • A nationwide study analyzed data from over 372,000 trauma patients to assess the impact of doctor cars compared to non-physician-staffed emergency services on survival rates.
  • The results indicate that patients treated by doctor cars have a significantly higher chance of survival in the hospital, suggesting that these units could enhance trauma care strategies in Japan.
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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.

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Chemically 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).

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Comprehensive 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.

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Werner'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.

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The 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.

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Hard 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.

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Article Synopsis
  • After endovascular abdominal aortic aneurysm repair (EVAR), patients often experience a significant inflammatory response marked by high fever and increased C-reactive protein (CRP), impacting recovery.
  • A study evaluated the effects of administering steroids, specifically intravenous methylprednisolone, on this postoperative inflammatory response by comparing 25 patients receiving steroids (Group S) against 65 patients who did not (Group C).
  • The results showed that patients in Group S had lower CRP levels and maximum body temperatures in the early days after surgery, suggesting that steroid pretreatment can help reduce inflammation without raising the risk of infections.
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We 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.

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  • - Functional tricuspid regurgitation (FTR) negatively impacts long-term survival in patients with mitral valve disease, and tricuspid annuloplasty (TAP) with an MC3 ring is commonly performed during left-sided heart surgeries to address this issue.
  • - A study comparing two techniques found that the septal adjustment technique (SAT) resulted in significantly lower postoperative tricuspid regurgitation (TR) grades and greater TR area reduction compared to the conventional technique.
  • - The early outcomes suggest that using SAT during TAP provides better control over postoperative TR, potentially improving patient results after surgery.
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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.

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Severe 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.

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Article Synopsis
  • The antero-lateral partial sternotomy (ALPS) approach is introduced as a less invasive surgical technique for treating extensive thoracic arch aneurysms compared to the traditional median sternotomy (MS) method.
  • A study involving 18 patients undergoing the ALPS approach showed no hospital mortality and minimal postoperative complications when compared to 22 patients treated with the MS approach.
  • The ALPS method allows for better surgical access and accuracy in the distal anastomosis, as indicated by a significantly lower vertebral level for the anastomosis in the ALPS group.
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  • A less invasive alternative called thoracic endovascular aortic repair (TEVAR) has shown success in treating AEF, as demonstrated in three patient cases, two of whom survived long-term without infection.
  • TEVAR should be promptly considered for patients with advanced esophageal cancer showing early signs of AEF, such as chest discomfort or irregular findings on CT scans.
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