Impact of Lactate Clearance on Clinical and Neurological Outcomes of Patients With Out-of-Hospital Cardiac Arrest Treated With Extracorporeal Cardiopulmonary Resuscitation: A Secondary Data Analysis.

OBJECTIVES: Serial evaluations of lactate concentration may be more useful in predicting outcomes in patients with out-of-hospital cardiac arrest (OHCA) than a single measurement. This study aimed to evaluate the impact of lactate clearance (LC) on clinical and neurologic outcomes in patients with OHCA who underwent extracorporeal cardiopulmonary resuscitation (ECPR). DESIGN: Retrospective multicenter observational study. SETTING: Patients with OHCA receiving ECPR at 36 hospitals in Japan between January 1, 2013, and December 31, 2018. PATIENTS: This study evaluated 1227 patients, with lactate initial assessed upon emergency department admission and lactate second measured subsequently. To adjust for the disparity in the time between lactate measurements, the modified 6-hour LC was defined as follows: ([lactate initial -lactate second ]/lactate initial ) × 100 × (6/the duration between the initial and second measurements [hr]). The patients were divided into four groups according to the modified 6-hour LC with an equivalent number of patients among LC quartiles: Q1 (LC < 18.8), Q2 (18.8 < LC < 59.9), Q3 (60.0 < LC < 101.2), and Q4 (101.2 < LC). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The 30-day survival rates increased as the 6-hour LC increased (Q1, 21.2%; Q2, 36.8%; Q3, 41.4%; Q4, 53.6%; p for trend < 0.001). In the multivariate analysis, the modified 6-hour LC was significantly associated with a 30-day survival rate (adjusted odds ratio [AOR], 1.003; 95% CI, 1.001-1.005; p < 0.001) and favorable neurologic outcome (AOR, 1.002; 95% CI, 1.000-1.004; p = 0.027). CONCLUSIONS: In patients with OHCA who underwent ECPR, an increase in the modified 6-hour LC was associated with favorable clinical and neurologic outcome. Thus, LC can be a criterion to assess whether ECPR should be continued.

Prognostic Significance of Signs of Life in Out-of-Hospital Cardiac Arrest Patients Undergoing Extracorporeal Cardiopulmonary Resuscitation.

OBJECTIVES: Signs of life (SOLs) during cardiac arrest (gasping, pupillary light reaction, or any form of body movement) are suggested to be associated with favorable neurologic outcomes in out-of-hospital cardiac arrest (OHCA). While data has demonstrated that extracorporeal cardiopulmonary resuscitation (ECPR) can improve outcomes in cases of refractory cardiac arrest, it is expected that other contributing factors lead to positive outcomes. This study aimed to investigate whether SOL on arrival is associated with neurologic outcomes in patients with OHCA who have undergone ECPR. DESIGN: Retrospective multicenter registry study. SETTING: Thirty-six facilities participating in the Study of Advanced life support for Ventricular fibrillation with Extracorporeal circulation in Japan II (SAVE-J II). PATIENTS: Consecutive patients older than 18 years old who were admitted to the Emergency Department with OHCA between January 1, 2013, and December 31, 2018, and received ECPR. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Patients were classified into two groups according to the presence or absence of SOL on arrival. The primary outcome was a favorable neurologic outcome (Cerebral Performance Category 1 or 2) at discharge. Of the 2157 patients registered in the SAVE-J II database, 1395 met the inclusion criteria, and 250 (17.9%) had SOL upon arrival. Patients with SOL had more favorable neurologic outcomes than those without SOL (38.0% vs. 8.1%; p < 0.001). Multivariate analysis showed that SOL on arrival was independently associated with favorable neurologic outcomes (odds ratio, 5.65 [95% CI, 3.97-8.03]; p < 0.001). CONCLUSIONS: SOL on arrival was associated with favorable neurologic outcomes in patients with OHCA undergoing ECPR. In patients considered for ECPR, the presence of SOL on arrival can assist the decision to perform ECPR.

Prophylactic distal perfusion catheter and survival in patients with out-of-hospital cardiac arrest: Secondary analysis of the SAVE-J II study.

PURPOSE: The effect of a prophylactic distal perfusion catheter (DPC) after extracorporeal cardiopulmonary resuscitation (ECPR) in patients with out-of-hospital cardiac arrest (OHCA) remains unclear. Therefore, we aimed to clarify the association between prophylactic DPC and prognosis in patients with OHCA undergoing ECPR. MATERIALS AND METHODS: A secondary analysis of the Study of Advanced Life Support for Ventricular Fibrillation with Extracorporeal Circulation in Japan (SAVE-J II) database was performed to compare groups of patients with and without prophylactic DPCs. A multivariate analysis of survival at discharge was performed using factors that were significant in the two-arm comparison. RESULTS: A total of 2044 patients were included in the analysis after excluding those who met the exclusion criteria. Survival at discharge was observed in 548 (26.9%) patients. In total, 100 (4.9%) patients developed limb ischemia, among whom 14 (0.7%) required therapeutic intervention. Multivariate analysis showed that prophylactic DPC did not result in a significant difference in survival at discharge (odds ratio: 0.898 [0.652-1.236], p = 0.509). CONCLUSIONS: The implementation of prophylactic DPC after ECPR for patients with OHCA may not contribute to survival at discharge.

Optimal chest compression for cardiac arrest until the establishment of ECPR: Secondary analysis of the SAVE-J II study.

INTRODUCTION: The widespread incorporation of extracorporeal cardiopulmonary resuscitation (ECPR) for out-of-hospital cardiac arrest requires the delivery of effective and high-quality chest compressions prior to the initiation of ECPR. The aim of this study was to evaluate and compare the effectiveness of mechanical and manual chest compressions until the initiation of ECPR. METHODS: This study was a secondary analysis of the Japanese retrospective multicenter registry "Study of Advanced Life Support for Ventricular Fibrillation by Extracorporeal Circulation II (SAVE-J II)". Patients were divided into two groups, one receiving mechanical chest compressions and the other receiving manual chest compressions. The primary outcome measure was mortality at hospital discharge, while the secondary outcome was the cerebral performance category (CPC) score at discharge. RESULTS: Of the 2157 patients enrolled in the SAVE-J II trial, 453 patients (329 in the manual compression group and 124 in the mechanical compression group) were included in the final analysis. Univariate analysis showed a significantly higher mortality rate at hospital discharge in the mechanical compression group compared to the manual compression group (odds ratio [95% CI] = 2.32 [1.34-4.02], p = 0.0026). Multivariate analysis showed that mechanical chest compressions were an independent factor associated with increased mortality at hospital discharge (adjusted odds ratio [95% CI] = 2.00 [1.11-3.58], p = 0.02). There was no statistically significant difference in CPC between the two groups. CONCLUSION: For patients with out-of-hospital cardiopulmonary arrest who require ECPR, extreme caution should be used when performing mechanical chest compressions.

Low-flow time and outcomes in out-of-hospital cardiac arrest patients treated with extracorporeal cardiopulmonary resuscitation.

INTRODUCTION: In out-of-hospital cardiac arrest (OHCA) patients with extracorporeal cardiopulmonary resuscitation (ECPR), the association between low-flow time, the duration between the initiation of conventional cardiopulmonary resuscitation and the establishment of ECPR, and outcomes has not been clearly determined. METHODS: This was a secondary analysis of the retrospective multicenter registry in Japan. This study registered patients ≥18 years old who were admitted to the emergency department for OHCA and underwent ECPR between January, 2013 and December, 2018. Low-flow time was defined as the time from initiation of conventional cardiopulmonary resuscitation to the establishment of ECPR, and patients were categorized into two groups according to the visualized association of the restricted cubic spline curve. The primary outcome was survival discharge. Cubic spline analyses and multivariable logistic regression analyses were performed to assess the nonlinear associations between low-flow time and outcomes. RESULTS: A total of 1,524 patients were included. The median age was 60 years, and the median low-flow time was 52 (42-53) mins. The overall survival at hospital discharge and favorable neurological outcomes were 27.8% and 14.2%, respectively. The cubic spline analysis showed a decreased trend of survival discharge rates and favorable neurological outcomes with shorter low-flow time between 20 and 60 mins, with little change between the following 60 and 80 mins. The multivariable logistic regression analyses showed that patients with long low-flow time (>40 mins) compared to those with short low-flow time (0-40 mins) had significantly worse survival (adjusted odds ratio 0.42; 95% confidence intervals, 0.31-0.57) and neurological outcomes (0.65; 0.45-0.95, respectively). CONCLUSIONS: The survival discharge and neurological outcomes of patients with low-flow time shorter than 40 min are better than those of patients with longer low-flow time.

The role of torsional stress in the development of subchondral insufficiency fracture of the femoral head: A finite element model analysis.

BACKGROUND: Subchondral insufficiency fracture of the femoral head generally occurs without evidence of trauma or with a history of minor trauma. Insufficient bone quality is considered one cause; however, the detailed mechanism of fracture development at the subchondral area (SA) is not understood. The aim of this study was to clarify the directions of force that cause subchondral fracture using finite element model analysis. METHODS: Two types of finite element models were generated from the CT data of femurs obtained from three individuals without osteoporosis (normal models) and another three with osteoporosis (osteoporosis models). Three directions of force, including compressive, shearing, and torsional, were applied to the femoral head. The distribution of von Mises stress (Mises stress) was evaluated at the SA, principal compressive trabeculae (PC), and principal tensile trabeculae. RESULTS: Under compressive force, the mean Mises stress value was greatest at the PC in both the normal and osteoporosis models. Under shearing force, the mean Mises stress value tended to be greatest at the SA in the normal model and at the PC in the osteoporosis model. Under torsional force, the mean Mises stress value was greatest at the SA in both types of models. CONCLUSIONS: The torsional force showed the greatest Mises stress at the SA in both the normal and osteoporosis models, suggesting the importance of torsion as a possible force responsible for subchondral insufficiency fracture development.

Side-to-side variability in the femoral neck anteversion angle: A study of the Japanese population with osteonecrosis of the femoral head.

BACKGROUND: Side-to-side variability in the femoral neck anteversion angle (FA) reportedly varies from 0.0° to 17.3°. To investigate the side-to-side variability in the FA and the relationship between the FA and the morphology of the acetabulum in the Japanese population, we performed a three-dimensional computed tomography (CT)-based study involving patients with osteonecrosis of the femoral head (ONFH). METHODS: CT data were obtained from 170 nondysplastic hips of 85 patients with ONFH. The FA and acetabular coverage parameters, including the acetabular anteversion angle, acetabular inclination angle, and acetabular sector angle in the anterior, superior, and posterior directions, were measured using three-dimensional CT. The distribution of the side-to-side variability in the FA was evaluated separately for each of the five degrees. RESULTS: The mean side-to-side variability in the FA was 6.7° ± 5.3° (range, 0.2°-26.2°). The distribution of the side-to-side variability in the FA was 0.0°-5.0° in 41 patients (48.2%), 5.1°-10.0° in 25 patients (29.4%), 10.1°-15.0° in 13 patients (15.3%), 15.1°-20.0° in 4 patients (4.7%), and >20.1° in 2 patients (2.4%). There was a weak negative correlation between the FA and anterior acetabular sector angle (r = -0.282, P < 0.001) and a very weak positive correlation between the FA and acetabular anteversion angle (r = 0.181, P < 0.018). CONCLUSIONS: The mean side-to-side variability in the FA was 6.7° ± 5.3° (range, 0.2°-26.2°) in Japanese nondysplastic hips, and about 20% of the patients had a side-to-side variability of >10°.

Wider Dissemination of Simplified Chest Compression-Only Cardiopulmonary Resuscitation Training Combined With Conventional Cardiopulmonary Resuscitation Training and 10-Year Trends in Cardiopulmonary Resuscitation Performed by Bystanders in a City.

BACKGROUND: Little is known about how to effectively increase bystander cardiopulmonary resuscitation (CPR), so we evaluated the 10-year trend of the proportion of bystander CPR in an area with wide dissemination of chest compression-only CPR (CCCPR) training combined with conventional CPR training.Methods and Results: We conducted a descriptive study after a community intervention, using a prospective cohort from September 2010 to December 2019. The intervention consisted of disseminating CCCPR training combined with conventional CPR training in Toyonaka City since 2010. We analyzed all non-traumatic out-of-hospital cardiac arrest (OHCA) patients resuscitated by emergency medical service personnel. The primary outcome was the trend of the proportion of bystander CPR. We conducted multivariate logistic regression models and assessed the adjusted odds ratio (AOR) using a 95% confidence interval (CI) to determine bystander CPR trends. Since 2010, we have trained 168,053 inhabitants (41.9% of the total population of Toyonaka City). A total of 1,508 OHCA patients were included in the analysis. The proportion of bystander CPR did not change from 2010 (43.3%) to 2019 (40.0%; 1-year incremental AOR 1.02 [95% CI: 0.98-1.05]). CONCLUSIONS: The proportion of bystander CPR did not increase even after wider dissemination of CPR training. In addition to continuing wider dissemination of CPR training, other strategies such as the use of technology are necessary to increase bystander CPR.

Prevalence, reasons, and timing of decisions to withhold/withdraw life-sustaining therapy for out-of-hospital cardiac arrest patients with extracorporeal cardiopulmonary resuscitation.

BACKGROUND: Extracorporeal cardiopulmonary resuscitation (ECPR) is rapidly becoming a common treatment strategy for patients with refractory cardiac arrest. Despite its benefits, ECPR raises a variety of ethical concerns when the treatment is discontinued. There is little information about the decision to withhold/withdraw life-sustaining therapy (WLST) for out-of-hospital cardiac arrest (OHCA) patients after ECPR. METHODS: We conducted a secondary analysis of data from the SAVE-J II study, a retrospective, multicenter study of ECPR in Japan. Adult patients who underwent ECPR for OHCA with medical causes were included. The prevalence, reasons, and timing of WLST decisions were recorded. Outcomes of patients with or without WLST decisions were compared. Further, factors associated with WLST decisions were examined. RESULTS: We included 1660 patients in the analysis; 510 (30.7%) had WLST decisions. The number of WLST decisions was the highest on the first day and WSLT decisions were made a median of two days after ICU admission. Reasons for WLST were perceived unfavorable neurological prognosis (300/510 [58.8%]), perceived unfavorable cardiac/pulmonary prognosis (105/510 [20.5%]), inability to maintain extracorporeal cardiopulmonary support (71/510 [13.9%]), complications (10/510 [1.9%]), exacerbation of comorbidity before cardiac arrest (7/510 [1.3%]), and others. Patients with WLST had lower 30-day survival (WLST vs. no-WLST: 36/506 [7.1%] vs. 386/1140 [33.8%], p < 0.001). Primary cerebral disorders as cause of cardiac arrest and higher severity of illness at intensive care unit admission were associated with WLST decisions. CONCLUSION: For approximately one-third of ECPR/OHCA patients, WLST was decided during admission, mainly because of perceived unfavorable neurological prognoses. Decisions and neurological assessments for ECPR/OHCA patients need further analysis.

Femoral nerve status during the anterolateral approach for total hip arthroplasty: Motor-evoked potential analysis and an influencing factor.

BACKGROUND: Femoral nerve palsy is an uncommon but serious complication during the anterolateral approach for total hip arthroplasty. One of the reported reasons for femoral nerve palsy is retractor-induced intraoperative damage after retractor placement on the anterior wall of the acetabulum. The present study aimed to clarify the femoral nerve status during anterolateral approach total hip arthroplasty using motor-evoked potential analysis and to identify risk factors influencing the nerve status. METHODS: From June 2019 to September 2020, 32 hips in 31 patients underwent primary total hip arthroplasty via the anterolateral approach. The integrity of the femoral nerve was tested by the motor-evoked potential at three time points: preoperatively as a control (first period), immediately after retractor placement on the anterior wall of the acetabulum (second period), and after the procedure (third period). In the second period, the hips were divided into the following two groups: a <50% femoral nerve amplitude group and a ≥50% group. The iliopsoas muscle volume was evaluated by measuring the muscle cross-sectional area on preoperative computed tomography images, and compared between the two groups. RESULTS: The mean amplitude of the femoral nerve was significantly reduced from 100% in the first period to 35% in the second period (p < 0.01), but then significantly recovered to 54% in the third period (p < 0.01). In 26 (81%) hips, the femoral nerve amplitude was <50% in the second period. The muscle cross-sectional area of the iliopsoas muscle in the <50% group was significantly smaller than that in the ≥50% group (p < 0.05). CONCLUSIONS: The mean amplitude of the femoral nerve was significantly reduced to 35% in the second period, and the iliopsoas muscle volume was considered to influence this femoral nerve status.

Laypersons' Psychological Barriers Against Rescue Actions in Emergency Situations　- A Questionnaire Survey.

BACKGROUND: Although bystanders' performance is important to improve outcomes of patients after cardiac arrests, few studies have investigated the barriers of bystanders, including those who could not perform cardiopulmonary resuscitation or any other rescue actions in emergency situations. This study aimed to assess the relationship between the psychological barriers of laypersons who encountered emergency situations and their rescue actions.Methods and Results:A questionnaire survey was conducted and this included laypersons who had encountered emergency situations during the last 5 years. Six questions were about the psychological barriers and 8 questions were about the laypersons' rescue actions. The primary outcome was any rescue actions performed by laypersons in an actual emergency situation. Overall, 7,827 (92.8%) of 8,430 laypersons responded; of them, 1,361 (16.1%) had encountered emergency situations during the last 5 years, and 1,220 (14.5%) were eligible for inclusion in the analyses. Of the 6 psychological barriers, "fear of approaching a collapsed person" (adjusted odds ratio [AOR] 0.50; 95% confidence interval [95% CI] 0.32-0.79) and "difficulties in judging whether to perform any rescue action" (AOR 0.63; 95% CI 0.40-0.99) were significantly associated with performing any rescue actions. CONCLUSIONS: The fear of approaching a collapsed person and difficulties in judging whether to take any actions were identified as the psychological barriers in performing any rescue actions by laypersons who encountered emergency situations.

Incidence of genitourinary injuries in pelvic fractures: A 12-year single-center retrospective study.

OBJECTIVE: This study aimed to determine the epidemiology of genitourinary injuries in pelvic fractures and elucidate the clinical outcomes of patients with pelvic fractures with and without genitourinary injuries at a tertiary trauma center in Japan. METHODS: Patients with pelvic fractures in our tertiary trauma center between May 2009 and April 2021 were retrospectively assessed. The patients' demographics, mechanism of injury, and hospital course details were collected. The outcomes of patients with pelvic fractures with and without genitourinary injuries were compared. RESULTS: Of 402 patients with pelvic fractures, 18 (4.5%) had genitourinary injuries. Falls were the most common mechanisms of injury for all pelvic fractures The incidence of bladder, kidney, urethral, and testis injuries were 2.0%, 1.2%, 1.2%, and 0.5%, respectively. Patients with genitourinary injuries were significantly younger (median age, 26 vs. 51 years; p < 0.001), had a higher rate of intensive care unit admission (94% vs. 58%; p = 0.002), remained hospitalized longer (median duration, 82 vs. 45 days; p < 0.001), and had a longer intensive care unit stay (median duration, 6 vs. 2 days; p < 0.001) when compared to patients without genitourinary injuries. Genitourinary injuries were not associated with in-hospital mortality. CONCLUSIONS: The incidence of genitourinary injuries with pelvic fractures was 4.5%. The presence of genitourinary injuries was associated with a higher rate of intensive care unit admission, longer hospital stay, and longer intensive care unit stay, but it was not associated with in-hospital mortality.

Extracorporeal cardiopulmonary resuscitation in adult patients with out-of-hospital cardiac arrest: a retrospective large cohort multicenter study in Japan.

BACKGROUND: The prevalence of extracorporeal cardiopulmonary resuscitation (ECPR) in patients with out-of-hospital cardiac arrest (OHCA) has been increasing rapidly worldwide. However, guidelines or clinical studies do not provide sufficient data on ECPR practice. The aim of this study was to provide real-world data on ECPR for patients with OHCA, including details of complications. METHODS: We did a retrospective database analysis of observational multicenter cohort study in Japan. Adult patients with OHCA of presumed cardiac etiology who received ECPR between 2013 and 2018 were included. The primary outcome was favorable neurological outcome at hospital discharge, defined as a cerebral performance category of 1 or 2. RESULTS: A total of 1644 patients with OHCA were included in this study. The patient age was 18-93 years (median: 60 years). Shockable rhythm in the initial cardiac rhythm at the scene was 69.4%. The median estimated low flow time was 55 min (interquartile range: 45-66 min). Favorable neurological outcome at hospital discharge was observed in 14.1% of patients, and the rate of survival to hospital discharge was 27.2%. The proportions of favorable neurological outcome at hospital discharge in terms of shockable rhythm, pulseless electrical activity, and asystole were 16.7%, 9.2%, and 3.9%, respectively. Complications were observed during ECPR in 32.7% of patients, and the most common complication was bleeding, with the rates of cannulation site bleeding and other types of hemorrhage at 16.4% and 8.5%, respectively. CONCLUSIONS: In this large cohort, data on the ECPR of 1644 patients with OHCA show that the proportion of favorable neurological outcomes at hospital discharge was 14.1%, survival rate at hospital discharge was 27.2%, and complications were observed during ECPR in 32.7%.

Roles of excess minority carrier recombination and chemisorbed O2 species at SiO2/Si interfaces in Si dry oxidation: Comparison between p-Si(001) and n-Si(001) surfaces.

This study provides experimental evidence for the following: (1) Excess minority carrier recombination at SiO2/Si interfaces is associated with O2 dissociative adsorption; (2) the x-ray induced enhancement of SiO2 growth is not caused by the band flattening resulting from the surface photovoltaic effect but by the electron-hole pair creation resulting from core level photoexcitation for the spillover of bulk Si electronic states toward the SiO2 layer; and (3) a metastable chemisorbed O2 species plays a decisive role in combining two types of the single- and double-step oxidation reaction loops. Based on experimental results, the unified Si oxidation reaction model mediated by point defect generation [S. Ogawa et al., Jpn. J. Appl. Phys., Part 1 59, SM0801 (2020)] is extended from the viewpoints of (a) the excess minority carrier recombination at the oxidation-induced vacancy site and (b) the trapping-mediated adsorption through the chemisorbed O2 species at the SiO2/Si interface.

Mechanical Influence of Pubic Nonunion on the Stress Distribution After Curved Periacetabular Osteotomy: Patient-Specific Three-Dimensional Finite Element Analysis.

BACKGROUND: Pubic nonunion after curved periacetabular osteotomy (CPO) reportedly occurs in 1%-17% of patients and causes pubic pain in 21%. Furthermore, pubic nonunion is associated with a risk of ischial ramus stress fracture, but the mechanical influence of pubic nonunion has not been fully clarified. METHODS: Patient-specific finite element (FE) analysis was performed using Mechanical Finder software. Three FE models (pre-CPO, union, and nonunion models) were constructed from preoperative and postoperative computed tomographic data. The contact area (mm2) and contact pressure (MPa) in the hip joint as well as the equivalent stress (MPa) at the ischial ramus were evaluated among the 3 FE models. RESULTS: Patient-specific FE models were generated using 18 consecutive hips treated with CPO. The mean contact pressure in the hip joint was not significantly different between the union and nonunion models (0.50 ± 0.10 vs 0.50 ± 0.09 MPa, P = .88). However, the mean equivalent stress at the ischial ramus in the nonunion models was 1.7 times higher than that in the union models (1.13 ± 0.77 vs 0.64 ± 0.45 MPa, P < .01). CONCLUSION: FE analysis revealed that pubic nonunion did not affect the mechanical distribution in the hip joint itself but increased the mean equivalent stress at the ischial ramus. This finding suggests the importance of achieving pubic union after CPO to avoid the risk of ischial ramus stress fracture.

High reactivity of H2O vapor on GaN surfaces.

Understanding the process of oxidation on the surface of GaN is important for improving metal-oxide-semiconductor (MOS) devices. Real-time X-ray photoelectron spectroscopy was used to observe the dynamic adsorption behavior of GaN surfaces upon irradiation of H2O, O2, N2O, and NO gases. It was found that H2O vapor has the highest reactivity on the surface despite its lower oxidation power. The adsorption behavior of H2O was explained by the density functional molecular dynamic calculation including the spin state of the surfaces. Two types of adsorbed H2O molecules were present on the (0001) (+c) surface: non-dissociatively adsorbed H2O (physisorption), and dissociatively adsorbed H2O (chemisorption) molecules that were dissociated with OH and H adsorbed on Ga atoms. H2O molecules attacked the back side of three-fold Ga atoms on the (0001̅) (-c) GaN surface, and the bond length between the Ga and N was broken. The chemisorption on the (101̅0) m-plane of GaN, which is the channel of a trench-type GaN MOS power transistor, was dominant, and a stable Ga-O bond was formed due to the elongated bond length of Ga on the surface. In the atomic layer deposition process of the Al2O3 layer using H2O vapor, the reactions caused at the interface were more remarkable for p-GaN. If unintentional oxidation can be resulted in the generation of the defects at the MOS interface, these results suggest that oxidant gases other than H2O and O2 should be used to avoid uncontrollable oxidation on GaN surfaces.

Impact of the COVID-19 pandemic on a trauma center of a university hospital in Japan.

BACKGROUND: The Coronavirus disease 2019 pandemic caused the Japanese government to declare a State of Emergency on April 7, 2020. The aim of this study is to provide an overview of the effects of the pandemic on surgical cases at a university hospital trauma center. METHODS: An observational study was performed at a trauma center in a tertiary hospital in Tokyo, Japan. The number of surgeries was compared between two periods: a historical control period (Tuesday April 9 to Monday May 27, 2019) and the period of the Japan State of Emergency due to COVID-19 (Tuesday April 7-Monday May 25, 2020). Information on patient age, gender, and surgical diagnosis, site, and procedure was collected for cases operated on in each period. The number of trauma surgeries was compared between the two periods. Data from the two periods were compared statistically. RESULTS: The total number of surgical cases was 151 in the control period and 83 in the COVID-19 period (including no cases with COVID-19), a decrease of 45.0%. There were significantly more surgeries for patients with hip fractures in the COVID-19 period (9 vs. 19, P < 0.001 by Fisher exact test). CONCLUSIONS: During the State of Emergency in Japan, the number of operations for trauma patients at the trauma center decreased, but surgeries for hip fracture increased.

Serum D-dimer level as a predictor of neurological functional prognosis in cases of head injuries caused by road traffic accidents.

BACKGROUND: The number of traffic fatalities is declining in Japan; however, a large proportion of head injuries are still attributable to traffic accidents. Severe head trauma may cause progressive and devastating coagulopathy owing to exacerbated coagulation and fibrinolysis, which results in massive bleeding and poor patient outcomes. D-dimer is a fibrinolytic marker, which remarkably increases in severe coagulopathy due to the exacerbated fibrinolytic system. Because the degree of coagulopathy is associated with patient outcomes, the D-dimer level is a useful prognostic predictor in patients with head trauma. However, the usefulness of D-dimer in cases of head trauma caused by road traffic accidents remains inadequately explored. In this study, we investigated the relationship between D-dimer levels and outcomes in head injuries caused by traffic accidents. METHODS: We extracted data on traffic injuries from Japan Neuro-Trauma Data Bank Project 2015, which is a prospective multicenter registry of head injuries. The analysis included 335 individuals with no missing data. The outcome variable was the score of the Glasgow Outcome Scale (GOS), a neurological outcome index. The participants were categorized into the favorable outcome (GOS score ≥ 4) and poor outcome (GOS score ≤ 3) groups. The serum D-dimer levels at the time of admission were divided into four categories at the quartiles, and the reference category was less than the first quartile (< 17.4 µg/mL). We performed a logistic regression analysis with GOS as the dependent variable and D-dimer as a predictor and performed a multivariate analysis that was adjusted for 10 physiological parameters. RESULTS: In the univariate analysis, all groups with serum D-dimer values ≥ 17.4 µg/dL showed significantly poorer outcomes than those of the reference group. In the multivariate analysis, after adjusting for other factors, D-dimer levels ≥ 89.3 µg/dL were an independent predictor of poor outcome. CONCLUSION: After adjusting for physiological parameters, high serum D-dimer levels can be an independent factor for predicting neurological prognosis in head trauma caused by road traffic accidents.

2020 International Consensus on First Aid Science With Treatment Recommendations.

This is the summary publication of the International Liaison Committee on Resuscitation's 2020 International Consensus on First Aid Science With Treatment Recommendations. It addresses the most recent published evidence reviewed by the First Aid Task Force science experts. This summary addresses the topics of first aid methods of glucose administration for hypoglycemia; techniques for cooling of exertional hyperthermia and heatstroke; recognition of acute stroke; the use of supplementary oxygen in acute stroke; early or first aid use of aspirin for chest pain; control of life-threatening bleeding through the use of tourniquets, hemostatic dressings, direct pressure, or pressure devices; the use of a compression wrap for closed extremity joint injuries; and temporary storage of an avulsed tooth. Additional summaries of scoping reviews are presented for the use of a recovery position, recognition of a concussion, and 6 other first aid topics. The First Aid Task Force has assessed, discussed, and debated the certainty of evidence on the basis of Grading of Recommendations, Assessment, Development, and Evaluation criteria and present their consensus treatment recommendations with evidence-to-decision highlights and identified priority knowledge gaps for future research.

Oxidation of Anatase TiO2(001) Surface Using Supersonic Seeded Oxygen Molecular Beam.

We investigated the oxidation of oxygen vacancies at the surface of anatase TiO2(001) using a supersonic seeded molecular beam (SSMB) of oxygen. The oxygen vacancies at the top surface and subsurface could be eliminated by the supply of oxygen using an SSMB. Oxygen vacancies are present on the surface of anatase TiO2(001) when it is untreated before transfer to a vacuum chamber. These vacancies, which are stable in the as-grown condition, could also be effectively eliminated by using the oxygen SSMB.