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Background: Homologous recombination deficiency (HRD) is one of the crucial hallmarks of cancer. It is associated with a favorable response to platinum-based chemotherapy. We explored the distinctive clinicopathological features of gastric cancer (GC) with HRD and the clinical significance of HRD in platinum-based first-line chemotherapy for unresectable metastatic GC., Methods: We enrolled 160 patients with GC in this study. Their tumor samples were subjected to genomic profiling utilizing targeted tumor sequencing. HRD was defined as the presence of alterations in any of 16 HR genes (BARD1, BLM, BRCA1, BRCA2, BRIP1, MRE11A, NBN, PALB2, PARP1, POLD1, RAD50, RAD51, RAD51C, RAD51D, WRN, and XRCC2). The clinicopathological features and treatment outcomes of first-line chemotherapy for unresectable metastatic GC were compared between HRD and non-HRD groups., Results: Forty-seven patients (29.4%) were classified into the HRD group. This group had a significantly lower proportion of macroscopic type 3 or 4 tumors and higher TMB than the non-HRD group. Among patients who underwent platinum-based first-line chemotherapy, the HRD group had a greater response rate and longer progression-free survival after treatment (median 8.0 months vs. 3.0 months, P = 0.010), with an adjusted hazard ratio of 0.337 (95% confidence interval 0.151-0.753). HRD status was not associated with treatment outcomes in patients who did not undergo platinum-based chemotherapy., Conclusions: Low proportion of macroscopic type 3 or 4 tumors and a high TMB are distinctive features of GC with HRD. HRD status is a potential predictive marker in platinum-based first-line chemotherapy for unresectable metastatic GC., (© 2024. The Author(s) under exclusive licence to The International Gastric Cancer Association and The Japanese Gastric Cancer Association.)

The incidence and type distribution of human adenovirus (HAdV) infections among children with pharyngoconjunctival fever (PCF) in Osaka, Japan between 2019 and 2023 were analyzed to assess the effect of the coronavirus disease 2019 (COVID-19) pandemic. The number of reported PCF cases in Osaka decreased from 2020 to 2022, followed by an unprecedented increase in 2023. HAdV-C strains, including types C1, C2, and C5, were detected in throughout the study period. Conversely, HAdV-B3 was not detected for 2 years and 9 months from March 2020 to December 2022, but the number of detections increased from July 2023. Overall, HAdV-B3 was the most frequently detected type (27 of 52 strains), and genetic analysis of its hexon hypervariable regions showed that, except for one strain, the HAdV-B3 strains identified after 2022 had different amino acid substitutions to those identified in 2019 and 2020. These results suggest that the PCF epidemic in 2023 was predominantly caused by variant strains of HAdV-B3, and that children were susceptible owing to a lack of exposure to HAdV-B3 between 2020 and 2022. Ongoing surveillance is needed to evaluate the impact of COVID-19 on the prevalence of HAdV infection.

Objectives: Opioid availability for the palliative care of patients with advanced cancer is increasing globally. However, opioid availability remains extremely low in Japan. We investigated whether pain is appropriately controlled by low-dose opioid prescriptions in patients with advanced cancer in Japan., Methods: A web-based nationwide survey for caregivers from 2000 community comprehensive support care centers was performed in Japan to assess details about pain in the 30 days before patients died of end-stage cancer. Separately, the data for opioid prescription doses and medical services in the 90 days before the death of patients with cancer were extracted from a health insurance claim database., Results: Responses from 1034 responders were retrieved and 665 patients were included. In total, 254 patients (38.2%) complained of severe-to-intolerable cancer-related pain. The median cumulative prescription dose of opioids in the 90 days before patient death was 311.0 mg by oral morphine equivalent doses. Multiple regression analyses across prefectures revealed that the proportion of patients with severe-to-intolerable cancer-related pain was negatively associated with the cumulative opioid consumption expressed as morphine-equivalent doses within 90 days before death., Conclusions: The very low availability of opioids for patients with end-stage cancer could result in high rate of severe-to-intolerable cancer-related pain patients. There were several limitations in this study, and the interpretations of the findings should be carefully. However, the increase in the absolute dose of opioids could improve the palliative care framework to the pain control levels of the global standard., (© 2024 The Authors. Neuropsychopharmacology Reports published by John Wiley & Sons Australia, Ltd on behalf of The Japanese Society of Neuropsychopharmacology.)

Objective: To investigate the opioid prescription status around clinical events among patients with breast cancer in Japan using a comprehensive claims database., Methods: This was a retrospective cohort study using the National Database (April 2009-March 2020). The target patients had a first breast cancer diagnosis in April 2010 or later. The percentages of patients prescribed opioids before and after surgery, before and after bone metastasis, and before death with a breast cancer diagnosis in the same month were analyzed by month and by clinical facility characteristics and location., Results: We identified 1 085 388 target patients, including 216 503, 72 645, and 70 832 patients with data for the events of surgery, bone metastasis, and death, respectively. The percentage of patients prescribed opioids in the month of surgery was the highest of the entire study period at ≥70%. The percentage of patients prescribed opioids increased before bone metastasis, peaked 1 month later, and decreased thereafter while remaining higher than that before the event. The percentage of patients who were prescribed opioids before death increased over time, peaking at 33.4% 1 month before death. Prescriptions differed by facility characteristics and facility location around surgery; no differences by facility characteristics, including location, were noted around the other events. The percentage of patients prescribed opioids was consistently lower than that reported in other countries for all events., Conclusions: We showed the opioid prescription status around clinical events, including some distinct patterns depending on facility characteristics for the period around surgery, among patients with breast cancer in Japan., (© The Author(s) 2024. Published by Oxford University Press.)

Ni/Co-free high-energy positive electrode materials are of great importance to ensure the sustainability of Li-ion battery production and its supply chain in addition to minimizing environmental impact. Here, nanostructured LiMnO 2 with both orthorhombic/monoclinic layered domains is synthesized, and its lithium storage properties and mechanism are examined. High-energy mechanical milling is used to convert the metastable and nanosized LiMnO 2 adopting the cation-disordered rocksalt structure to an optimal domain-segregated layered LiMnO 2 . This positive electrode produces an energy density of 820 W h kg -1 , achieved by harnessing a large reversible capacity with relatively small voltage hysteresis on electrochemical cycles. Moreover, voltage decay for cycling, as observed for Li-excess Mn-based electrode materials, is effectively mitigated. Furthermore, by determining the structure-property relationships of different LiMnO 2 polymorphs, LiMnO 2 with similar domain structure and surface area is successfully synthesized with an alternative and simpler method, without the metastable precursor and high-energy mechanical milling. The cyclability of domain-containing LiMnO 2 is also improved with the use of a highly concentrated electrolyte coupled with a lithium phosphate coating due to the suppression of Mn dissolution. These findings maximize the possibility of the development of high-energy, low-cost, and practical rechargeable batteries made from sustainable and abundant Mn sources without Ni/Co., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

Neoadjuvant chemotherapy(NAC)is prescribed for resectable esophagogastric junctional cancer on the basis of esophageal invasion length, lymph node metastasis, and pathological diagnosis. Due to a lack of consensus in Japan, however, discussion regarding its use is necessary. This study comprised 6 patients who underwent surgical resection after receiving NAC in our department from 2018 to 2022. All the patients were male, with a median age of 67 years. Three patients underwent SP therapy, 2 received SOX therapy, and 1 received both SOX and HER therapy. A total gastrectomy was performed in 3 cases, a fundectomy in 1 case, and a subtotal esophagectomy with gastric tube reconstruction in 2 cases. The histological types were tub2 in 3 cases; and tub1 plus pap, por1 plus pap, and NEC in 1 case each, respectively. One case was ypStage ⅠA, 2 cases were ⅠB, 1 was ⅡA, 1 was ⅡB and 1 was pCR. Currently, all the patients remain alive and without recurrence. NAC has, therefore, been demonstrated to be an effective therapeutic strategy for esophagogastric junctional cancer in this study. However, further research with a larger sample size is required.

Background: The association between inactivated influenza vaccination and viral load in young children remains unclear., Methods: During the 2013/2014 to 2017/2018 influenza seasons in Japan, children under 6 years of age with pre-defined influenza-like illness and influenza-positive status by real-time RT-PCR were recruited at pediatric clinics for this observational study. Influenza viral load was measured for the most predominant subtype/lineage in each season. Using median dichotomized viral load as an outcome, a multilevel logistic regression model was applied to estimate the multivariable adjusted odds ratio (MOR) and 95% confidence interval (CI) for higher viral load., Results: A total of 1,185 influenza-positive children were analyzed. The median log 10 viral load copy number (copies per milliliter) was 5.5 (interquartile range, 4.6 to 6.1) and did not differ by vaccination status: 5.5 for unvaccinated, 5.7 for one dose, and 5.5 for two doses (p = 0.67). The MOR of vaccinated (one or two doses) versus unvaccinated children was 1.19 (95% CI: 0.86-1.64). Other factors showing significant associations with higher viral load were positive results for A(H1N1)pdm09 and A(H3N2) in comparison with B/Yamagata. The respective MORs were 3.25 (95% CI: 2.28-4.64) and 1.81 (95% CI: 1.32-2.49). Significantly elevated MORs against higher viral load were also observed for higher body temperature at influenza diagnosis and shorter duration from fever onset to specimen collection., Conclusion: No association was observed between inactivated-influenza vaccination and viral load at influenza-positive diagnosis. Influenza subtype/lineage, body temperature, and time elapsed since fever onset were significantly associated with viral load., (© 2023 The Authors. Influenza and Other Respiratory Viruses published by John Wiley & Sons Ltd.)

Sulfide glasses can exhibit notable ionic conductivity because of annealing-associated crystallization. One well-known example is Li 7 P 3 S 11 . Our research showed that adding bromine (Br) to Li 3 PS 4 sulfide glass results in a similar crystal structure and high ionic conductivity comparable to that of another compound Li 10 GeP 2 S 12 . This structure differs from the PS 4 anion framework of Li 3 PS 4 . In addition, the ionic conductivity decreases owing to a structural transition to the β-phase. Herein, we present our findings on the local structure of Li 3 PS 4 sulfide glass and its crystallized glass ceramic with the addition of Br. This analysis relies on the pair distribution function analysis obtained from high-energy X-ray diffraction. Moreover, using the bond valence sum method, we verified that incorporating Br promotes the formation of Li ionic conduction pathways. Our results indicate that precise control over the anion molecular structure by introducing halogens holds promise for achieving high Li-ion conductivity., (© 2023. Springer Nature Limited.)

Pancreatic ductal adenocarcinoma (PDAC) is a type of cancer with a high mortality rate. Current treatments for PDACs often have side effects, and drug resistance in cancer stem cells (CSCs) would be also a problem. Cyclic guanosine monophosphate (cGMP) suppresses the mitochondrial function of PDACs and inhibits their CSC properties. Metabolic regulation plays a crucial role in the maintenance of CSC phenotype, and we hypothesized that cGMP induction suppresses cancer stem cell properties in the cancer cell through energy-related signaling pathways. We demonstrated that induction of cGMP upregulated the PPARα/PDK4 pathway and suppressed CSC properties in PDAC, and patients with pancreatic cancer with high PDK4 gene expression had a better prognosis than those with low gene expression. Therefore, these mechanisms may provide new therapeutic targets for the eradication of pancreatic CSCs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Introduction: During the recent coronavirus disease 2019 (COVID-19) pandemic, preferences for factors associated with vaccines have been evaluated. Three oral antiviral drugs have been approved in Japan for patients with mild-to-moderate I COVID-19 symptoms. Although preferences for the drugs may also depend on various factors, these have not been fully evaluated., Methods: A conjoint analysis was performed based on an online survey in August 2022 to estimate the intangible costs of factors associated with oral antiviral drugs for COVID-19. Respondents were individuals aged 20-69 across Japan. The attributes included the company (Japanese/foreign) that developed the drug, formulation and size of the drug, frequency of administration per day, number of tablets/capsules per dose, number of days until no longer infectious to others, and out-of-pocket expenses. A logistic regression model was applied to estimate the utility of each level for each attribute. The intangible costs were calculated by comparing the utility to the out-of-pocket attribute., Results: Responses were collected from 11,303 participants. The difference between levels was the largest for companies that developed a drug; the intangible costs were JPY 5390 higher for the foreign company than for the Japanese company. The next largest difference was in the number of days until one is no longer infectious. For the same formulation, the intangible cost was lower for small sizes than large sizes. For similar-sized tablets and capsules, the intangible cost was lower for tablets than capsules. These tendencies were similar regardless of COVID-19 infection history and the presence of risk factors for severe COVID-19 in the respondents., Conclusion: Intangible costs for factors associated with oral antiviral drugs among the Japanese population were estimated. The results may change as the number of people with a history of COVID-19 infection increases and significant progress is made regarding treatments., (© 2023. The Author(s).)

Purpose: Breast cancer is the most common cancer among Japanese women and often yields a better prognosis than other cancers. However, few studies have been conducted on pain control using opioids in Japan. In this study, we aimed to examine actual opioid use among breast cancer patients., Methods: Breast cancer patients were defined as female patients with a first breast cancer diagnosis during the observational period in an acute care hospital database (April 2008 - February 2020). We examined the percentage of patients prescribed opioids, the opioid amount per patient, and the opioid dosage per day around surgery, bone metastasis diagnosis, or death., Results: Overall, 217,722 breast cancer patients were identified. The percentage of patients prescribed opioids and the average amount of opioids per patient were highest in the month of surgery, 78% and 27 morphine milligram equivalents (MMEs), respectively. The average opioid dosage increased with time after surgery from 19 to 28 MMEs. Around bone metastasis, the percentage of patients prescribed opioids and the average opioid amount per patient peaked one month after the diagnosis, 31% and 371 MMEs, respectively. The average opioid dosage gradually increased from 22 to 35 MMEs in succeeding days after a bone metastasis diagnosis. The percentage of patients prescribed opioids and the average opioid amount per patient increased as the month of death approached., Conclusion: We investigated opioid prescription trends around clinical events in breast cancer patients on a large scale in Japan. These results may be useful to control cancer pain among breast cancer patients., (© 2023. The Author(s).)

To study vaccine-induced neutralizing antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants isolated in Osaka, Japan, microneutralization tests were performed on serum samples from 32subjects who received a second dose of vaccination, and 10 of those who received the third dose of vaccination. Geometric mean titres (GMTs) for the D614G strain, Alpha variant, Delta variant, and Omicron BA.1 of the subjects after the second dose of vaccination were 19.5, 21.8, 6.3 and 2.0, respectively. The GMT for the Delta variant was significantly lower than that for the D614G strain and Alpha variant, and the GMT for the Omicron BA.1 was significantly lower than that for the Delta variant. Among the subjects who received three doses of vaccination, the GMTs for the Omicron BA.1 (62.8) and BA.2 (38.6) were significantly higher than that for the Omicron BA.1 after the second dose. Thus, in the present study, the second dose of vaccination induced neutralizing antibodies against SARS-CoV-2 strains, and the reactivity of neutralizing antibodies to the variants was thought to be enhanced by the third dose of vaccination. The serum samples used in this study will be useful in evaluating the reactivity of vaccine-induced antibodies to newly emerging variants., Competing Interests: The authors declare that there are no conflicts of interest., (© 2023 The Authors.)

Delivering inherently stable lithium-ion batteries is a key challenge. Electrochemical lithium insertion and extraction often severely alters the electrode crystal chemistry, and this contributes to degradation with electrochemical cycling. Moreover, electrodes do not act in isolation, and this can be difficult to manage, especially in all-solid-state batteries. Therefore, discovering materials that can reversibly insert and extract large quantities of the charge carrier (Li + ), that is, high capacity, with inherent stability during electrochemical cycles is necessary. Here lithium-excess vanadium oxides with a disordered rocksalt structure are examined as high-capacity and long-life positive electrode materials. Nanosized Li 8/7 Ti 2/7 V 4/7 O 2 in optimized liquid electrolytes deliver a large reversible capacity of over 300 mAh g -1 with two-electron V 3+ /V 5+ cationic redox, reaching 750 Wh kg -1 versus metallic lithium. Critically, highly reversible Li storage and no capacity fading for 400 cycles were observed in all-solid-state batteries with a sulfide-based solid electrolyte. Operando synchrotron X-ray diffraction combined with high-precision dilatometry reveals excellent reversibility and a near dimensionally invariable character during electrochemical cycling, which is associated with reversible vanadium migration on lithiation and delithiation. This work demonstrates an example of an electrode/electrolyte couple that produces high-capacity and long-life batteries enabled by multi-electron transition metal redox with a structure that is near invariant during cycling., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)

The dynamic structure factorS(Q,E), where Q and E are momentum and energy transfer, respectively, has been measured for liquid Eu 8 Ga 16 Ge 30 (EGG), using inelastic x-ray scattering. The excitation energy of the longitudinal acoustic mode in the liquid was scaled to that in liquid Ba 8 Ga 16 Sn 30 (BGS) with the effective mass. This result means that the local structure in both liquids are similar. The longitudinal acoustic excitation energy of type-I clathrate compound EGG disperses faster than that in the liquid, suggesting that the interatomic force is weakened on melting. The lower energy excitation was observed in both liquid EGG and liquid BGS. In comparison with the longitudinal phonon dispersion in crystalline clathrate compound EGG obtained by density functional theory-based calculations, the lower energy in the liquid was found to be near the optical mode energy. The result indicates that the lower energy mode arises from the relative motion between Eu and (Ga, Ge) atoms., (© 2023 IOP Publishing Ltd.)

Aims: To investigate the preferences of the Japanese population for government policies expected to address infectious disease outbreaks and epidemics., Methods: We performed a conjoint analysis based on survey data in December 2022 (registration number: UMIN000049665). The attributes for the conjoint analysis were policies: tests, vaccines, therapeutic drugs, behavior restrictions (e.g. self-restraint or restrictions on the gathering or travel of individuals and the hours of operation or serving of alcoholic beverages in food/beverage establishments), and entry restrictions (from abroad), and monetary attribute: an increase in the consumption tax from the current 10%, to estimate the monetary value of the policies. A logistic regression model was used for the analysis., Results: Data were collected from 2,185 respondents. The accessibility of tests, vaccines, and therapeutic drugs was preferred regardless of the accessibility level. The value for accessibility of drugs to anyone at any medical facility was estimated at 4.80% of a consumption tax rate, equivalent to JPY 10.5 trillion, which was the highest among the policies evaluated in this study. The values for implementing behavior or entry restrictions were negative or lower than those for tests, vaccines, and drugs., Limitations: Respondents chosen from an online panel were not necessarily representative of the Japanese population. Because the study was conducted in December 2022, a period during the coronavirus disease 2019 (COVID-19) pandemic, the results may reflect the situation at that time and potentially be subject to rapid change., Conclusions: Among the policy options evaluated in this study, the most preferred option was easily accessible therapeutic drugs and their monetary value was substantial. Wider accessibility of tests, vaccines, and drugs was preferred over behavior and entry restrictions. We believe that the results provide information for policymaking to prepare for future infectious disease epidemics and for assessing the response to COVID-19 in Japan.

Background: Acute exacerbation is an essential prognostic factor in idiopathic pulmonary fibrosis (IPF) and is the leading cause of death in Japanese patients with IPF. Its epidemiology, treatment status, and effect on IPF progression have been insufficiently investigated. We examined the incidence of acute exacerbation and treatment status before and after the onset of acute exacerbation in Japanese patients with IPF to provide basic information for treatment strategies., Methods: A Japanese claims database (April 2008-March 2019) from acute-care hospitals was analyzed. Incidence of acute exacerbation, time to the next event, and percentages of patients who received each treatment by the year before and after the onset of acute exacerbation were examined in patients diagnosed with IPF at least once. Acute exacerbation was defined according to the use of steroid pulse therapy., Results: We identified 9961 patients with IPF and 2629 acute exacerbations (average age at the time of acute exacerbation: 74.8 years, percentage of men: 79%). The annual incidence of acute exacerbation was approximately 10% between 2010 and 2018. The time to the next acute exacerbation shortened with increasing number of these events. The percentage of patients receiving antifibrotic drugs remained constant (30%-40%) throughout the period. The percentages of patients receiving steroid therapy, immunosuppressive drugs, and oxygen therapy increased after the onset of acute exacerbation compared with before the onset., Conclusions: The annual incidence of acute exacerbation was approximately 10% in recent years. It is suggested that acute exacerbation worsens respiratory function in patients with IPF., Competing Interests: Conflict of Interest Sakae Homma received lecture fees from Nippon Boehringer Ingelheim Co., Ltd. Takafumi Suda received lecture fees from Nippon Boehringer Ingelheim Co., Ltd. and AstraZeneca K.K. and received research funding from Nippon Boehringer Ingelheim Co., Ltd., Novartis Pharma K.K., Ono Pharmaceutical Co., Ltd., and AstraZeneca K.K. He also received subsidies or donations from Astellas Pharma Inc., Ono Pharmaceutical Co., Ltd., Daiichi Sankyo Company Limited, Taiho Pharmaceutical Co., Ltd., Takeda Pharmaceutical Company Limited, Novartis Pharma K.K., Pfizer Japan Inc., and Nippon Boehringer Ingelheim Co Ltd. Yoshie Hongo, Manami Yoshida, and Shinzo Hiroi are employees of Shionogi & Co., Ltd., and own shares in Shionogi & Co., Ltd. Kosuke Iwasaki and Tomomi Takeshima are employees of Milliman Inc., which received consultancy fees from Shionogi & Co., Ltd. Yasuhiro Kondoh received lecture fees from Nippon Boehringer Ingelheim Co., Ltd., and Shionogi & Co., Ltd., (Copyright © 2022 [The Author/The Authors]. Published by Elsevier B.V. All rights reserved.)

Background: Treatment for idiopathic pulmonary fibrosis (IPF) has changed over the past decades. Understanding the actual status of IPF treatment and evaluating the consistency of the guidelines are important for improving the treatment strategy. However, the relevant information is insufficient in Japan. Therefore, this study investigated the treatment status and changes in the treatment of patients with IPF in Japan., Methods: This retrospective claims-based study used a Japanese claims database that included data from acute care hospitals (April 2008-March 2019). Patients with at least one record of definitive IPF diagnosis were classified as patients with IPF. We determined the percentage of patients who received each treatment type by the year., Results: We analyzed 9961 patients with IPF. The mean (standard deviation) age at first diagnosis was 74.4 (9.3) years, and 74.9% of the patients were men. The number of patients who did not take any drug treatment tended to decrease over the years. Nevertheless, approximately 30% of the patients did not take any drug treatment in recent years. The number of patients who received antifibrotic drugs increased over time, and it became the most popular treatment for ≥40% of the patients in and after 2017. Although steroid prescriptions tended to decrease over time, they were still administered to one-third of the patients with IPF who received drug treatment in and after 2017., Conclusions: Our findings suggest that changes in the IPF treatment reflect changes in guideline recommendations as well as the availability of treatment in clinical settings in Japan., Competing Interests: Conflict of Interest Takafumi Suda has received lecture fees from Nippon Boehringer Ingelheim Co., Ltd., and AstraZeneca K.K., and received research funding from Nippon Boehringer Ingelheim Co., Ltd., Novartis PharmaK.K., Ono Pharmaceutical Co., Ltd., and AstraZenecaK.K. He also received subsidies or donations from Astellas Pharma Inc., Ono Pharmaceutical Co., Ltd., Daiichi Sankyo Company Limited, Taiho Pharmaceutical Co., Ltd., Takeda Pharmaceutical Company Limited, Novartis Pharma K.K., Pfizer Japan Inc., and Nippon Boehringer Ingelheim Co Ltd. Yasuhiro Kondoh has received lecture fees from Nippon Boehringer Ingelheim Co., Ltd., and Shionogi & Co., Ltd. Yoshie Hongo, Manami Yoshida, and Shinzo Hiroi are employees of Shionogi & Co., Ltd., and own shares in Shionogi & Co Ltd. Kosuke Iwasaki and Tomomi Takeshima are employees of Milliman Inc., which has received consultancy fees from Shionogi & Co., Ltd. Sakae Homma has received lecture fees from Nippon Boehringer Ingelheim Co., Ltd., (Copyright © 2022 [The Author/The Authors]. Published by Elsevier B.V. All rights reserved.)

Intensive research is underway to further enhance the performance of lithium-ion batteries (LIBs). To increase the capacity of positive electrode materials, Li-rich layered oxides (LLO) are attracting attention but have not yet been put to practical use. The structural mechanisms through which LLO materials exhibit higher capacity than conventional materials remain unclear because their disordered phases make it difficult to obtain structural information by conventional analysis. The X-ray total scattering analysis reveals a disordered structure consisting of metal ions in octahedral and tetrahedral sites of Li layers as a result of cation mixing after the extraction of Li ions. Metal ions in octahedral sites act as rigid pillars. The metal ions move to the tetrahedral site of the Li layer, which functions as a Li-layer pillar during Li extraction, and returns to the metal site during Li insertion, facilitating Li diffusion as an adaptive pillar. Adaptive pillars are the specific structural features that differ from those of the conventional layered materials, and their effects are responsible for the high capacity of LLO materials. An essential understanding of the pillar effects will contribute to design guidelines for intercalation-type positive electrodes for next-generation LIBs., (© 2022 The Authors. Small published by Wiley-VCH GmbH.)

Background/aim: We previously reported three items that preoperatively predicted complicated appendicitis (body temperature, C-reactive protein, and fluid retention around the appendix). In this study, we aimed to compare other predictors to confirm the usefulness of our predictors with those of previous reports on the items as predictors of complicated appendicitis preoperatively (criteria A which consist of 8 items, criteria B which consist of 7 items)., Patients and Methods: We retrospectively evaluated 417 adult patients who underwent surgery for acute appendicitis between January 2013 and December 2019 and compared our items with criteria A and criteria B according to the results of the area under the receiver operating characteristic curve (AUC), homogeneity, discriminatory ability, and Akaike information criterion (AIC)., Results: The AUC for the sensitivity to diagnose complicated appendicitis according to according to our criteria, as well as criteria A, and criteria B was 0.823, 0.839, and 0.856, respectively. The discriminatory ability linear trend χ 2 of our criteria and those of criteria A and B were 128.9, 121.1, and 142.5, respectively. The homogeneity likelihood ratios χ 2 calculated using the Cox regression model, which indicate homogeneity, were 146.4, 143.6, and 172.8, respectively. The AIC of each criterion was 397.0, 345.8, and 369.0, respectively., Conclusion: Although the criteria B were the best, it was possible to predict complicated appendicitis preoperatively by all criteria. Above all, our criteria have only three items, therefore they have the advantage of making it possible to make decisions quickly with a certain degree of accuracy, regardless of the degree of experience., (Copyright © 2022, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Medical practices for influenza virus infection vary among countries. In Japan, treatment with anti-influenza drugs is recommended for patients diagnosed with influenza. This health claims database study provides quantitative information aimed at describing the actual medical practices, including diagnostic testing and medication use, for managing influenza in Japan. Most patients diagnosed with influenza underwent diagnostic tests and were prescribed anti-influenza drugs. Meanwhile, the majority of patients prescribed anti-influenza drugs had undergone diagnostic testing. However, an increase in the percentage of anti-influenza prescriptions without diagnostic testing was observed during the 2019-2020 influenza season, which may be associated with the COVID-19 pandemic., (© 2022 The Authors. Influenza and Other Respiratory Viruses published by John Wiley & Sons Ltd.)

Bimodal behavior in the translational order of silicon's second shell in SiO 2 liquid at high temperatures and high pressures has been recognized in theoretical studies, and the fraction of the S state with high tetrahedrality is considered as structural origin of the anomalous properties. However, it has not been well identified in experiment. Here we show experimental evidence of a bimodal behavior in the translational order of silicon's second shell in SiO 2 glass under pressure. SiO 2 glass shows tetrahedral symmetry structure with separation between the first and second shells of silicon at low pressures, which corresponds to the S state structure reported in SiO 2 liquid. On the other hand, at high pressures, the silicon's second shell collapses onto the first shell, and more silicon atoms locate in the first shell. These observations indicate breaking of local tetrahedral symmetry in SiO 2 glass under pressure, as well as SiO 2 liquid., (© 2022. The Author(s).)

Introduction: Certain drug characteristics, including dosage and form, are associated with either convenience or inconvenience for the patients taking them, and any inconvenience can be considered as a "cost" in disease treatment. Multiple antivirals are available for influenza in Japan, with various dosages and forms. This study evaluated the inconvenience costs associated with influenza antivirals for pediatric patients by using conjoint analysis on responses from their parents., Methods: An online survey (May 2021) was conducted for parents whose child took antivirals for influenza at 6-11 years during the 3 years until March 2021. Attributes of the conjoint analysis were administration routes and formulation (tablet, capsule, dry syrup, or inhalant), duration of administration, frequency of administration per day, and out-of-pocket expenses. We assumed the efficacy and safety to be equivalent among the antivirals. A logistic regression model was applied to the analysis. We also asked parents about their recent experiences with antiviral treatment for their child., Results: We collected responses from 3161 eligible individuals. The mean age (standard deviation) of the children when taking the antivirals and percentage of female children were 8.27 (1.63) years old and 53.2%, respectively. The tablet was the most preferred formulation; the inconvenience costs for each administration route and formulation, relative to the tablet as zero, were Japanese yen (JPY) 515 (US dollar 4.61, as of October 2021) for the inhalant, JPY 775 for the capsule, and JPY 804 for the dry syrup. The inconvenience costs for 5 days relative to 1 day and for twice a day relative to once a day were JPY 2150 and JPY 399, respectively., Conclusion: Based on the conjoint analysis, a single-dose tablet antiviral was suggested to have the lowest inconvenience cost for pediatric patients., Trial Registration: UMIN000044243., (© 2022. The Author(s).)

Background: Idiopathic pulmonary fibrosis (IPF) is a cryptogenic chronic interstitial pneumonia with progressive fibrosis and a poor prognosis. A substantial number of epidemiological studies have been conducted in Europe and the United States (US). In contrast, in Japan, only one study reported the prevalence of IPF (10.0 per 100,000 population) using clinical data (2003-2007) from one prefecture; thus, the nationwide prevalence of IPF remains unknown. This study aimed to estimate the nationwide prevalence of IPF in Japan using a nationwide claims database., Methods: We extracted data from a Japanese claims database provided by Medical Data Vision (MDV database, April 2008-March 2019) containing data from approximately 28 million patients from 385 acute-care hospitals. Patients with IPF (those diagnosed with IPF at least once) from April 2017 to March 2018 were identified in the MDV database. The number of patients in the MDV database was extrapolated nationwide using the fourth NDB Open Data (April 2017-March 2018), and the prevalence was estimated using demographic data as denominators. The prevalence in the US, considering the same definition of IPF, was also calculated and compared with that in Japan., Result: The number of patients with IPF in the MDV database was 4278. The estimated nationwide number of patients in Japan was estimated to be 34,040 (mean age: 73 years, percentage of men: 73%), and the prevalence was 27 per 100,000 population. In comparison with that in the US, the prevalence was similar in men and relatively lower in women until the age of 75-79 years, and it was notably lower in both sexes aged ≥ 80 years., Conclusions: We report the nationwide IPF prevalence in Japan using data from claims databases for the first time. The prevalence estimated in this study was higher than that reported in a previous study. The difference might be due to differences in study settings and definitions of IPF. Further research should be performed to determine the prevalence more accurately and compare it with those in other countries., (© 2022. The Author(s).)

Mixed neuroendocrine non-neuroendocrine neoplasm (MiNEN) of the pancreas is a rare entity, and obtaining a preoperative diagnosis is difficult. We present a 70-year-old man in whom the possibility of MiNEN was successfully discovered preoperatively by endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). Immunostaining revealed positive results for the neuroendocrine markers chromogranin A and synaptophysin. We considered the possibility for MiNEN before surgery. He underwent distal pancreatectomy with splenectomy. Immunohistochemical examination of the tumor cells showed a wide range of positivity for trypsin as well as for chromogranin A and synaptophysin. Considering that ≥ 30% tumors ware positive for both acinar and neuroendocrine markers, the patient was diagnosed with MiNEN. MiNEN is a malignant tumor that requires early detection and treatment but is a rare disease for which no method has been established. We found that EUS-FNA and immunostaining are effective diagnostic methods for MiNEN., (© 2021. Japanese Society of Gastroenterology.)

Introduction: Thrombocytopenia, a common complication of chronic liver disease (CLD), adversely affects the treatment in patients requiring invasive procedures. Multiple pathophysiological mechanisms contribute to the development of thrombocytopenia; thus, its incidence could differ among CLD etiologies. We investigated the risk of decline in platelet counts and developing thrombocytopenia across different CLDs in a real-world Japanese setting., Methods: A Japanese claims database including 25 million patients (April 2008-August 2018) was used. Patients with at least one CLD diagnosis were classified into nine mutually exclusive categories: hepatitis B, hepatitis C, hepatitis B and C, unspecified viral hepatitis, autoimmune hepatitis, toxin/drug-induced hepatitis, alcoholic hepatitis, nonalcoholic steatohepatitis, and others. A random effects model was used to estimate the changes in platelet counts; proportional hazard analyses were used to examine factors associated with the incidence of thrombocytopenia based on the diagnosis. Patients with laboratory test data as variables were included in each analysis., Results: The simulation included 68,536 patients. The mean values representing changes in the platelet count were significantly negative in the hepatitis C patients and negative, though non-significant, in the hepatitis B, toxin/drug-induced hepatitis, alcoholic hepatitis, and nonalcoholic steatohepatitis patients. In the proportional hazard analysis, 708 of 22,728 patients had thrombocytopenia. The hazard ratio (HR) was significantly high for patients with hepatitis B (HR, 2.879; p < 0.001), hepatitis C (HR, 1.876; p < 0.001), and hepatitis B and C (HR, 2.992; p < 0.001)., Conclusion: A decreasing tendency in platelet counts was observed in most CLD etiologies, with hepatitis C showing a significant decrease. The incidence of thrombocytopenia was mostly associated with hepatitis B and/or C. Further research is warranted to elucidate the discrepancy between the decline in platelet counts and thrombocytopenia diagnosis, considering the factors relevant to the diagnosis, such as the frequency of outpatient visits and CLD treatment., (© 2021. The Author(s).)

Aims: To estimate the cost of antiviral medication guidance and/or support from the perspective of healthcare professionals by administration route (oral or inhalant)., Methods: An online survey (December 2020) was conducted among physicians, pharmacists, and certified care workers. Those aged 20-64 years working in workplaces with experience of prescribing (physicians) or dispensing (pharmacists) antivirals for influenza, or having care service recipients who took antivirals (certified care workers) since October 2018, were selected through screening questions. The time required for guidance and/or support for drug administration was asked, and its monetary value was calculated by applying the Japanese average wage. Respondents who had a fear of infection while providing guidance and/or support were asked about the monetary value of this fear; the cost of fear was estimated from their responses and the percentage who reported such a fear., Results: Responses were collected from 1,000 physicians, 1,000 pharmacists, and 642 certified care workers. The cost of the time for guidance and/or support in the entire workplace was estimated as JPY 244 (USD 2.14, as of October 2021) for oral antivirals and JPY 289 for inhalants among physicians, JPY 260 and JPY 428 among pharmacists, and JPY 555 and JPY 557 among certified care workers. The cost of fear was estimated to be JPY 965 for oral and JPY 1,361 for inhalants among physicians, JPY 756 and JPY 2,711 among pharmacists, and JPY 2,419 and JPY 2,837 among certified care workers., Limitations: Respondents might not be representative of Japanese society. The reliability of the results depends on whether the respondents accurately understood the questions and their truthfulness., Conclusions: Higher costs for guidance and/or support were suggested for inhalant antivirals in physicians and pharmacists compared to oral antivirals. For certified care workers, almost no difference in costs was suggested between administration routes.

Introduction: Thrombocytopenia can increase the bleeding risk in patients with chronic liver disease (CLD) undergoing invasive procedures. Prophylactic platelet transfusion (PT) is often performed to increase platelet counts in patients with CLD undergoing invasive procedures to prevent bleeding. Lusutrombopag, a small-molecule thrombopoietin receptor agonist, is expected to be an alternative therapy to prophylactic PT. This study aimed to compare the effects between lusutrombopag and PT., Methods: Data were obtained from a Japanese administrative database (April 2008-May 2019). Patients aged ≥ 18 years who underwent planned invasive procedures after the first CLD diagnosis and were observed for ≥ 30 days prior to invasive procedures were considered eligible. Patients who underwent planned invasive procedures with lusutrombopag prescription at 5-30 days before the procedure were categorized as the lusutrombopag group, whereas those who received PT at 1 day before and/or on the same day as the procedure, without lusutrombopag prescription, were classified as the PT group. Outcomes, including bleeding frequency during hospitalization and average medical costs (costs for prophylactic treatment and total costs between the day of the invasive procedure and 30 days after the invasive procedure), were compared between the groups after matching., Results: Among 738,878 patients with CLD, 379 cases for each group were identified after matching. The incidence of bleeding events was lower in the lusutrombopag group than in the PT group (3.7% vs. 8.2%, p < 0.001). Average medical costs were lower in the lusutrombopag group than in the PT group ($6667 as of August 2021 vs. $7170, p = 0.011)., Conclusion: Lusutrombopag is suggested to be effective as a prophylactic treatment for bleeding prevention in patients with CLD undergoing planned invasive procedures., (© 2021. The Author(s).)

Background: Although annual influenza vaccination is an important strategy used to prevent influenza-related morbidity and mortality, some studies have reported the negative influence of prior vaccination on vaccine effectiveness (VE) for current seasons. Currently, the influence of prior vaccination is not conclusive, especially in children., Methods: We evaluated the association between current-season VE and prior season vaccination using a test-negative design in children aged 1-5 years presenting at nine outpatient clinics in Japan during the 2016/17 and 2017/18 influenza seasons. Children with influenza-like illness were enrolled prospectively and tested for influenza using real-time RT-PCR. Their recent vaccination history was categorized into six groups according to current vaccination doses (0/1/2) and prior vaccination status (unvaccinated = 0 doses/vaccinated = 1 dose or 2 doses): (1) 0 doses in the current season and unvaccinated in prior seasons (reference group); (2) 0 doses in the current season and vaccinated in a prior season; (3) 1 dose in the current season and unvaccinated in a prior season; (4) 1 dose in the current season and vaccinated in a prior season; (5) 2 doses in the current season and unvaccinated in a prior season, and (6) 2 doses in the current season and vaccinated in a prior season., Results: A total of 799 cases and 1196 controls were analyzed. The median age of the subjects was 3 years, and the proportion of males was 54%. Overall, the vaccination rates (any vaccination in the current season) in the cases and controls were 36% and 53%, respectively. The VEs of the groups were: (2) 29% (95% confidence interval: -25% to 59%); (3) 53% (6% to 76%); (4) 70% (45% to 83%); (5) 56% (32% to 72%), and (6) 61% (42% to 73%). The one- and two-dose VEs of the current season were significant regardless of prior vaccination status. The results did not differ when stratified by influenza subtype/lineage., Conclusion: Prior vaccination did not attenuate the current-season VE in children aged 1 to 5 years, supporting the annual vaccination strategy.

The crystal structure, which intrinsically affects the properties of solids, is determined by the constituent elements and composition of solids. Therefore, it cannot be easily controlled beyond the phase diagram because of thermodynamic limitations. Here, we demonstrate the first example of controlling the crystal structures of a solid-solution nanoparticle (NP) entirely without changing its composition and size. We synthesized face-centered cubic (fcc) or hexagonal close-packed (hcp) structured Pd x Ru 1- x NPs ( x = 0.4, 0.5, and 0.6), although they cannot be synthesized as bulk materials. Crystal-structure control greatly improves the catalytic properties; that is, the hcp-Pd x Ru 1- x NPs exceed their fcc counterparts toward the oxygen evolution reaction (OER) in corrosive acid. These NPs only require an overpotential (η) of 200 mV at 10 mA cm -2 , can maintain the activity for more than 20 h, greatly outperforming the fcc-Pd 0.4 Ru 0.6 NPs (η = 280 mV, 9 min), and are among the most efficient OER catalysts reported. Synchrotron X-ray-based spectroscopy, atomic-resolution electron microscopy, and density functional theory (DFT) calculations suggest that the enhanced OER performance of hcp-PdRu originates from the high stability against oxidative dissolution., Competing Interests: The authors declare no competing financial interest., (© 2021 The Authors. Published by American Chemical Society.)

We report a total x-ray scattering (TXS) system for structural analysis of crystalline particle materials at the BL15XU NIMS beamline of SPring-8 in Japan. To achieve a high angular resolution over a high Q region up to 25 Å -1 , the TXS system was capable of measuring to 120° at an x-ray energy of 29.02 keV with five CdTe pin detectors. The sample alignment and measuring system were controlled by LabView software. The x-ray pair distribution function (PDF) results for Ni bulk powder and Pt and AgRh nanoparticles were successfully simulated by the PDFgui program. In addition, Rietveld refinement results were also obtained from x-ray diffraction patterns, reflecting long-range order in the Pt nanoparticles. We expect that this TXS system may be useful for understanding structural information of crystalline nanoparticles, including amorphous features at their surface region.

Identification and profiling of molecular fragments generated over the lifespan of halide perovskite solar cells are needed to overcome the stability issues associated with these devices. Herein, we report the characterization of buried CH 3 NH 3 PbI 3- x Cl x (HaP)-transport layer (TL) interfaces. By using hard X-ray photoelectron spectroscopy in conjunction with transmission electron microscopy, we reveal that the chemical decomposition of HaP is TL-dependent. With NiO 1-δ , phenyl-C 61 -butyric acid methyl ester (PCBM), or poly(bis(4-phenyl) (2,4,6-trimethylphenyl)amine) (PTAA) as TLs, probing depth analysis shows that the degradation takes place at the interface (HaP/TL) rather than the HaP bulk area. From core-level data analysis, we identified iodine migration toward the PCBM- and PTAA-TLs. Unexpected diffusion of nitrogen inside NiO 1-δ -TL was also found for the HaP/NiO 1-δ sample. With a HaP/PCBM junction, HaP is dissociated to PbI 2 , whereas HaP/PTAA contact favored the formation of CH 3 I. The low stability of HaP solar cells in the PTAA-TL system is attributed to the formation of CH 3 I and iodide ion vacancies. Improved stability observed with NiO 1-δ -TL is related to weak dissociation of stoichiometric HaP. Here, we provide a new insight to further distinguish different mechanisms of degradation to improve the long-term stability and performance of HaP solar cells.

Since the coronavirus disease 2019 (COVID-19) outbreak, laboratory diagnosis has mainly been conducted using reverse-transcription polymerase chain reaction (RT-PCR). Detecting the presence of an infectious virus in the collected sample is essential to analyze if a person can transmit infectious severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, there have been no quantitative investigations conducted for infectious SARS-CoV-2 in clinical samples. Therefore, in the present study, a rapid and simple focus-forming assay using the peroxidase-antiperoxidase technique was developed to quantify infectious SARS-CoV-2 titers in 119 samples (n = 52, nasopharyngeal swabs [NPS]; n = 67, saliva) from patients with COVID-19. Furthermore, the study findings were compared with the cycle threshold (Ct) values of real-time RT-PCR. The infectious virus titers in NPS samples and Ct values were inversely correlated, and no infectious virus could be detected when the Ct value exceeded 30. In contrast, a low correlation was observed between the infectious virus titers in saliva and Ct values (r = -0.261, p = 0.027). Furthermore, the infectious virus titers in the saliva were significantly lower than those in the NPS samples. Ten days after the onset of COVID-19 symptoms, the infectious virus was undetectable, and Ct values were more than 30 in NSP and saliva samples. The results indicate that patients whose symptoms subsided 10 days after onset, with Ct values more than 30 in NSP and saliva samples, were less likely to infect others., (© 2021 The Authors. Journal of Medical Virology published by Wiley Periodicals LLC.)

Since 1970, people have been making every endeavor to reduce toxic emissions from automobiles. After the development of a three-way catalyst (TWC) that concurrently converts three harmful gases, carbon monoxide (CO), hydrocarbons (HCs), and nitrogen oxides (NO x ), Rh became an essential element in automobile technology because only Rh works efficiently for catalytic NO x reduction. However, due to the sharp price spike in 2007, numerous efforts have been made to replace Rh in TWCs. Nevertheless, Rh remains irreplaceable, and now, the price of Rh is increasing significantly again. Here, it is demonstrated that PdRuM ternary solid-solution alloy nanoparticles (NPs) exhibit highly durable and active TWC performance, which will result in a significant reduction in catalyst cost compared to Rh. This work provides insights into the design of highly durable and efficient functional alloy NPs, guiding how to best take advantage of the configurational entropy in addition to the mixing enthalpy., (© 2021 Wiley-VCH GmbH.)

Water is the only available fossil-free source of hydrogen. Splitting water electrochemically is among the most used techniques, however, it accounts for only 4% of global hydrogen production. One of the reasons is the high cost and low performance of catalysts promoting the oxygen evolution reaction (OER). Here, we report a highly efficient catalyst in acid, that is, solid-solution Ru‒Ir nanosized-coral (RuIr-NC) consisting of 3 nm-thick sheets with only 6 at.% Ir. Among OER catalysts, RuIr-NC shows the highest intrinsic activity and stability. A home-made overall water splitting cell using RuIr-NC as both electrodes can reach 10 mA cm -2 geo at 1.485 V for 120 h without noticeable degradation, which outperforms known cells. Operando spectroscopy and atomic-resolution electron microscopy indicate that the high-performance results from the ability of the preferentially exposed {0001} facets to resist the formation of dissolvable metal oxides and to transform ephemeral Ru into a long-lived catalyst.

In Japan, respiratory syncytial virus (RSV) infection generally has occurred during autumn and winter. However, a possible change in the seasonal trend of RSV infection has been observed recently. The current study was conducted to determine whether the epidemic season of RSV infection in Japan has indeed changed significantly. We used expectation-based Poisson scan statistics to detect periods with high weekly reported RSV cases (epidemic cluster), and the epidemic clusters were detected between September and December in the 2012-2016 seasons while those were detected between July and October in the 2017-2019 seasons. Non-linear and linear ordinary least squares regression models were built to evaluate whether there is a difference in year trend in the epidemic seasonality, and the epidemic season was shifted to earlier in the year in 2017-2019 compared to that in 2012-2016. Although the reason for the shift is unclear, this information may help in clinical practice and public health.

Aims: Estimating the monetary value of the convenience of using influenza antivirals approved in Japan from a patient perspective using a conjoint analysis., Methods: An online survey (August 2020) was performed on individuals aged 20-64 years living in Japan who had taken oral or inhalant antivirals for influenza treatment in the 2018/19 or 2019/20 seasons. Efficacy and safety were assumed to be equivalent among the antivirals. The attributes for the conjoint analysis included route (oral or inhalant), duration, frequency of administration, and out-of-pocket expenses. A conditional logit model was applied as a baseline model. The monetary value of each attribute was calculated by comparing the same utility of the linearly interpolated level of the out-of-pocket attribute. Another survey to determine the experiences of the latest antiviral intake was also conducted on the same respondents., Results: Of the respondents, 1,550 were men and 1,587 were women. The monetary value for oral antivirals was estimated to be higher, saving JPY 741 (USD 7.06, as of August 2020), compared with inhalant. Regarding the length and frequency of administration, five days corresponds to an increase of JPY 2,072, compared with one day, and twice a day corresponds to a JPY 574 increase compared to once a day., Conclusions: The results suggest that - among the antivirals approved in Japan - the monetary value of the utility is the highest in the single dose oral antiviral, baloxavir marboxil (baloxavir). Although the drug cost was highest in baloxavir among the brand antivirals, the difference in the value of utility for influenza patient was estimated to be larger than the difference in the drug costs., Limitations: Although individuals with diverse attributes from all over the country were included in the survey, they are not necessarily a representative population of the Japanese society.

After the first case of coronavirus disease 2019 (COVID-19) in Japan on 15 January 2020, multiple nationwide COVID-19 clusters were identified by the end of February. The Japanese government focused on mitigating the emerging COVID-19 clusters by conducting active nationwide epidemiological surveillance. However, an increasing number of cases continued to appear until early April 2020, many with unclear infection routes and no recent history of travel outside Japan. We aimed to evaluate the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genome sequences from the COVID-19 cases that appeared until early April 2020 and to characterize their genealogical networks in order to demonstrate possible routes of spread in Japan. Nasopharyngeal specimens were collected from patients, and reverse transcription-quantitative PCR tests for SARS-CoV-2 were performed. Positive RNA samples were subjected to whole-genome sequencing, and a haplotype network analysis was performed. Some of the primary clusters identified during January and February 2020 in Japan descended directly from the Wuhan-Hu-1-related isolates from China and other distinct clusters. Clusters were almost contained until mid-March; the haplotype network analysis demonstrated that the COVID-19 cases from late March through early April may have created an additional large cluster related to the outbreak in Europe, leading to additional spread within Japan. In conclusion, genome surveillance has suggested that there were at least two distinct SARS-CoV-2 introductions into Japan from China and other countries. IMPORTANCE This study aimed to evaluate the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genome sequences from COVID-19 cases and to characterize their genealogical networks to demonstrate possible routes of spread in Japan. We found that there were at least two distinct SARS-CoV-2 introductions into Japan, initially from China and subsequently from other countries, including Europe. Our findings can help understand how SARS-CoV-2 entered Japan and contribute to increased knowledge of SARS-CoV-2 in Asia and its association with implemented stay-at-home/shelter-in-place/self-restraint/lockdown measures. This study suggested that it is necessary to formulate a more efficient containment strategy using real-time genome surveillance to support epidemiological field investigations in order to highlight potential infection linkages and mitigate the next wave of COVID-19 in Japan., (Copyright © 2020 Sekizuka et al.)