Valley Pseudospin Polarized Evanescent Coupling between Microwave Ring Resonator and Waveguide in Phononic Topological Insulators.

A coupled ring-waveguide structure is at the core of bosonic wave-based information processing systems, enabling advanced wave manipulations such as filtering, routing, and multiplexing. However, its miniaturization is challenging due to momentum conservation issues in rings with larger curvature that induce significant backscattering and radiation leakage and hampering stable operation. Here, we address it by taking an alternative approach of using topological technology in wavelength-scale and microwave ring-waveguide coupled systems built in nanoengineered phononic crystals. Our approach, which leverages pseudospin conservation in valley topological systems, eliminates phonon backscattering and achieves directional evanescent coupling. The resultant hypersonic waves in the tiny ring exhibit robust transport and resonant circulation. Furthermore, the ring-waveguide hybridization enables critical coupling, where valley-dependent ring-waveguide interference blocks the transmission. Our findings reveal the capability of topological phenomena for managing ultrahigh-frequency phonons in nano/microscale structures and pave the way for advanced phononic circuits in classical and quantum signal processing applications.

Green upgrading of SPring-8 to produce stable, ultrabrilliant hard X-ray beams.

SPring-8-II is a major upgrade project of SPring-8 that was inaugurated in October 1997 as a third-generation synchrotron radiation light source. This upgrade project aims to achieve three goals simultaneously: achievement of excellent light source performance, refurbishment of aged systems, and significant reduction in power consumption for the entire facility. A small emittance of 50 pm rad will be achieved by (1) replacing the existing double-bend lattice structure with a five-bend achromat one, (2) lowering the stored beam energy from 8 to 6 GeV, (3) increasing the horizontal damping partition number from 1 to 1.3, and (4) enhancing horizontal radiation damping by installing damping wigglers in long straight sections. The use of short-period in-vacuum undulators allows ultrabrilliant X-rays to be provided while keeping a high-energy spectral range even at the reduced electron-beam energy of 6 GeV. To reduce power consumption, the dedicated, aged injector system has been shut down and the high-performance linear accelerator of SACLA, a compact X-ray free-electron laser (XFEL) facility, is used as the injector of the ring in a time-shared manner. This allows the simultaneous operation of XFEL experiments at SACLA and full/top-up injection of the electron beam into the ring. This paper overviews the concept of the SPring-8-II project, the system design of the light source and the details of the accelerator component design.

Observation of Acoustically Induced Dressed States of Rare-Earth Ions.

Acoustically induced dressed states of long-lived erbium ions in a crystal are demonstrated. These states are formed by rapid modulation of two-level systems via strain induced by surface acoustic waves whose frequencies exceed the optical linewidth of the ion ensemble. Multiple sidebands and the reduction of their intensities appearing near the surface are evidence of a strong interaction between the acoustic waves and the ions. This development allows for on-chip control of long-lived ions and paves the way to highly coherent hybrid quantum systems with telecom photons, acoustic phonons, and electrons.

Fission Dynamics of a Ferrofluid Droplet on a Smooth Plate under a Nonuniform Magnetic Field.

A ferrofluid droplet on a plate undergoes interesting fission under a magnetic field. In this article, a recently developed simplified multiphase lattice Boltzmann method coupled with a self-correction solution for the magnetic potential equation is employed to explore this complex flow phenomenon. It is found that the droplet fission follows a four-pattern process under a nonuniform magnetic field. The mechanisms behind this behavior are influenced by the strength and gradient of the magnetic field, surface tension, droplet size, and the wetting boundary condition. These findings provide valuable insights into the application of ferrofluids in droplet microfluidics and contribute to advancements in this field.

Prognostic factors based on histological categorization of desmoplastic reactions in pancreatic cancer.

BACKGROUND/PURPOSE: In colorectal cancer, the morphological categorization of fibrotic cancer stroma in the invasive frontal zone of the primary tumor is well reflected in the prognosis. Conversely, the histological characteristics of pancreatic cancer (PC) reveal fibrotic hyperplasia of stroma known as desmoplasia; however, its characterization is unknown. Therefore, this study aimed to evaluate the prognostic factors according to the histological categorization of desmoplastic reactions in PC. METHODS: We retrospectively enrolled 167 patients who underwent curative resection for PC. The desmoplastic pattern was histologically classified as mature, intermediate, or immature. Clinicopathological features were evaluated, and disease-free and overall survival (OS) were analyzed in the three groups. Prognostic factors were assessed using univariate and multivariate analyses. RESULTS: In total, 19 mature, 87 intermediate, and 61 immature desmoplastic patterns were evaluated. Jaundice decompression, white blood cell count, and platelet/lymphocyte ratio were significantly different among the groups. The mature group had a better disease-free survival (DFS) prognosis than the other two groups; however, OS did not differ between the groups. Desmoplastic patterns showed significant differences between the three groups for DFS. CONCLUSIONS: Desmoplastic patterns are a prognostic factor of DFS for PC, with mature desmoplastic reactions associated with good prognosis. Thus, they may aid in individualized therapeutic approaches in patients with PC.

Bioremediation of Hazardous Pollutants Using Enzyme-Immobilized Reactors.

Bioremediation uses the degradation abilities of microorganisms and other organisms to remove harmful pollutants that pollute the natural environment, helping return it to a natural state that is free of harmful substances. Organism-derived enzymes can degrade and eliminate a variety of pollutants and transform them into non-toxic forms; as such, they are expected to be used in bioremediation. However, since enzymes are proteins, the low operational stability and catalytic efficiency of free enzyme-based degradation systems need improvement. Enzyme immobilization methods are often used to overcome these challenges. Several enzyme immobilization methods have been applied to improve operational stability and reduce remediation costs. Herein, we review recent advancements in immobilized enzymes for bioremediation and summarize the methods for preparing immobilized enzymes for use as catalysts and in pollutant degradation systems. Additionally, the advantages, limitations, and future perspectives of immobilized enzymes in bioremediation are discussed.

Essential roles of the hypothalamic A11 region and the medullary raphe nuclei in regulation of colorectal motility in rats.

The supraspinal brain regions controlling defecation reflex remain to be elucidated. The purpose of this study was to determine the roles of the hypothalamic A11 region and the medullary raphe nuclei in regulation of defecation. For chemogenetic manipulation of specific neurons, we used the double virus vector infection method in rats. hM3Dq or hM4Di was expressed in neurons of the A11 region and/or the raphe nuclei that send output to the lumbosacral defecation center. Immunohistological and functional experiments revealed that both the A11 region and the raphe nuclei directly connected with the lumbosacral spinal cord through descending pathways composed of stimulatory monoaminergic neurons. Stimulation of the hM3Dq-expressing neurons in the A11 region or the raphe nuclei enhanced colorectal motility only when GABAergic transmission in the lumbosacral spinal cord was blocked by bicuculline. Experiments using inhibitory hM4Di-expressing rats revealed that enhancement of colorectal motility caused by noxious stimuli in the colon is mediated by both the A11 region and the raphe nuclei. Furthermore, suppression of the A11 region and/or the raphe nuclei significantly inhibited water avoidance stress-induced defecation. These findings demonstrate that the A11 region and the raphe nuclei play an essential role in the regulation of colorectal motility. This is important because brain regions that mediate both intracolonic noxious stimuli-induced defecation and stress-induced defecation have been clarified for the first time.NEW & NOTEWORTHY The A11 region and the raphe nuclei, constituting descending pain inhibitory pathways, are related to both intracolonic noxious stimuli-induced colorectal motility and stress-induced defecation. Our findings may provide an explanation for the concurrent appearance of abdominal pain and defecation disorders in patients with irritable bowel syndrome. Furthermore, overlap of the pathway controlling colorectal motility with the pathway mediating stress responses may explain why stress exacerbates bowel symptoms.

Clinical and laboratory characteristics of complex febrile seizures in the acute phase: a case-series study in Japan.

BACKGROUND: Patients with complex febrile seizures (CFS) often display abnormal laboratory results, unexpectedly prolonged seizures, and/or altered consciousness after admission. However, no standardized values have been established for the clinical and laboratory characteristics of CFS in the acute phase, making the management of CFS challenging. This study aimed to determine the clinical and laboratory characteristics of children with CFS during the acute phase. In particular, the duration of impaired consciousness and the detailed distribution of blood test values were focused. METHODS: We retrospectively reviewed medical records of a consecutive pediatric cohort aged 6-60 months who were diagnosed with CFS and admitted to Kobe Children's Hospital between October 2002 and March 2017. During the study period, 486 seizure episodes with confirmed CFS were initially reviewed, with 317 seizure episodes included in the analysis. Detailed clinical and laboratory characteristics were summarized. RESULTS: Among 317 seizure episodes (296 children with CFS), 302 required two or fewer anticonvulsants to be terminated. In 296 episodes showing convulsive seizures, median seizure duration was 30.5 min. The median time from onset to consciousness recovery was 175 min. Impaired consciousness lasting > 6, 8, and 12 h was observed in 13.9%, 7.6%, and 1.9% patients with CFS, respectively. Additionally, the distribution of aspartate aminotransferase, lactate dehydrogenase, creatinine, and glucose were clarified with 3, 10, 50, 90, and 97 percentile values. CONCLUSION: This study detailed the clinical and laboratory findings of acute-phase CFS using the data of the largest 15-year consecutive cohort of children with CFS. These results provide important information for appropriate acute management of CFS.

Time course of serum cytokine level changes within 72 h after onset in children with acute encephalopathy and febrile seizures.

BACKGROUND: Cytokine levels have been measured in acute encephalopathy (AE) to determine its pathology or as a diagnostic biomarker to distinguish it from febrile seizures (FS); however, the dynamics of cytokine level changes have not yet been fully captured in these two neurological manifestations. Thus, we aimed to explore the time course of serum cytokine level changes within 72 h after onset in AE and FS. METHODS: We retrospectively measured cytokine level in residual serum samples at multiple timepoints in seven children whose final diagnoses were AE or FS. RESULTS: The levels of 13 cytokines appeared to increase immediately after onset and peaked within 12-24 h after onset: interleukin (IL)-1ß, IL-4 IL-5, IL-6, IL-8, IL-10, IL-17, eotaxin, fibroblast growth factor, granulocyte colony-stimulating factor, interferon gamma, interferon-inducible protein-10, and macrophage chemoattractant protein-1. There were no dynamic changes in the levels of three cytokines (IL-1 receptor agonist, macrophage inflammatory protein-1α, and platelet-derived growth factor-bb) 72 h after onset. Levels of some cytokines decreased to around control levels within 48 h after onset: IL-1ß, IL-4, IL-5, IL-17, fibroblast growth factor, and interferon gamma. The levels of most cytokines appeared to be higher in AE, especially in hemorrhagic shock encephalopathy syndrome, than in FS. CONCLUSIONS: Cytokine levels in both AE and FS change dynamically, such as the levels of several cytokines increased within a few hours after onset and decreased at 12-24 h after onset. Therefore, it will be desirable to make clinical decisions regarding the administration of anti-inflammatory therapy in 24 h after onset in AE.

Glenoid wear after humeral head replacement with using a single implant in patients with cuff tear arthropathy more than five years.

BACKGROUND: The aim of this study was to investigate glenoid wear in patients with humeral head replacement with a smaller humeral head, who were observed for >5 years, and to examine the relationship between radiographic changes and clinical outcome. METHODS: In this study, 41 shoulders of 41 patients (13 men, 28 women) were followed up for >5 years. The mean patient age at the time of surgery was 70.5 years. The average follow-up period at short-term was 26.0 months, and intermediate-term was 66.5 months. We classified glenoid wear into four grades (i.e., Grade 0 to Grade 3). Age, sex, clinical scores, and range of motion were investigated in relation to the grade of glenoid wear. Radiographs of glenoid wear evaluated in the short-term were subsequently compared to radiographs obtained in the intermediate-term period. RESULTS: At the final follow-up, 16 (39%) patients had Grade 0 wear, 11 (27%) patients had Grade 1 wear, 10 (24%) patients had Grade 2 wear, and 4 (10%) patients had Grade 3 wear. The University of California-Los Angeles score, Japanese Orthopaedic Association score, and active forward flexion were significantly lower in the Grade 3 patients; however, Grade 3 patients did not have significant pain. No significant difference in age, sex, Constant score, active external rotation, and active internal rotation in relation to the grade of glenoid wear was observed. In total, 25 (61%) patients showed a progression of glenoid wear. Cases in which glenoid wear progressed after 4 years after surgery were rare. Two patients of Grade 3 underwent total shoulder arthroplasty revision at 16 months and 38 months, respectively. CONCLUSIONS: Glenoid wear occurred in 61% of patients at 5 years follow-up. Pain of Grade 3 patients was mild, therefore, if pain is not severe, revision surgery may not be necessary.

Pancreatic hamartoma: detection of harbouring NAB2::STAT6 fusion gene.

Hamartomas in the pancreas are rare and are often histologically and morphologically similar to solitary fibrous tumours (SFTs). We examined the differences between hamartomas and SFTs at the molecular level. METHODS AND RESULTS: Thirteen patients histopathologically diagnosed with pancreatic hamartoma were included in the study. We also performed STAT6 immunohistochemistry (IHC), which is used in the diagnosis of SFT. Furthermore, for the three cases in which RNA was extracted, reverse transcription polymerase chain reaction to search for NAB2::STAT6 fusions was used. Macroscopically, 13 patients had well-demarcated tumour lesions. Histologically, no islets of Langerhans were observed in the lesions, acinar tissue and ducts were unevenly distributed and elastic fibres were not observed around the ducts by Elastica van Gieson staining. One case contained a lipomatous hamartoma composed mainly of adipose tissue. Seven of the 13 cases demonstrated expression of STAT6 in the nuclei of intervening spindle cells. NAB2::STAT6 fusions were observed in two of the three cases in which RNA was extracted. These two cases also demonstrated STAT6 expression in spindle cells using STAT6 IHC. In one case of lipomatous hamartoma, we did not confirm NAB2::STAT6 fusion or STAT6 expression in STAT6 IHC. CONCLUSION: Of the 13 patients histopathologically diagnosed with hamartoma, two demonstrated NAB2::STAT6 fusions, suggesting the existence of pancreatic hamartomas with molecular-level components identical to those of SFT.

A protein identification method for proteomics using amino acid composition analysis with IoT-based remote control.

In the present study, we developed a protein identification method using low-cost and easy-to-operate amino acid composition analysis. The identification program automatically compares the quantitative result for each amino acid concentration obtained from the amino acid analysis to the amino acid composition data retrieved from the UniProt protein database. We found that the accuracy of protein identification using amino acid composition analysis was comparable to that of mass spectrometry analysis. The method was able to distinguish and identify differences in amino acid substitutions of several residues between proteins with high sequence homology. The identification accuracy of proteins was also improved by correcting the concentrations in the program for Cys, Trp, and Ile residues, which cannot be quantified by general sample preparation for amino acid analysis. Moreover, the amino acid analyzer was remotely controlled in accordance with the growing demand for remote work. The measured amino acid data were automatically uploaded to the IoT portal within a few minutes of each measurement, allowing researchers to download data and analyze them using the identification program anywhere and at any time by connecting to a network. The results indicated that the present method is useful for protein identification.

Serum cardiac troponin I is a candidate biomarker for cardiomyopathy in Duchenne and Becker muscular dystrophies.

INTRODUCTION/AIMS: Serum cardiac troponin I (cTnI), its relation to cardiomyopathy, and the contribution of the ACTN3 genotype to serum levels of cTnI in Duchenne and Becker muscular dystrophy (DMD and BMD, respectively) remain unknown. In this study we aimed to reveal the characteristics of cTnI, assess whether cTnI is a biomarker for cardiomyopathy in these dystrophinopathies, and evaluate the contribution of the ACTN3 genotype to the serum levels of cTnI in DMD patients. METHODS: Serum cTnI values obtained from 127 DMD and 47 BMD patients were analyzed retrospectively. The relationship between cTnI and echocardiography data or the ACTN3 XX genotype was assessed. RESULTS: The cTnI levels and proportion of patients with abnormal cTnI levels were significantly higher among DMD patients than BMD, especially in the second decade of life. In DMD, the cTnI level reached a maximum at 13 years, and left ventricular ejection fraction (LVEF) became abnormal approximately 1 year subsequently. In BMD, the cTnI level peaked at the age of 14 years, and LVEF became abnormal 3 years later. Decreased LVEF was observed after cTnI elevation in both populations. cTnI levels by age in DMD patients with the ACTN3 XX genotype tended to increase significantly and early. DISCUSSION: Myocardial injury indicated by cTnI elevation was more common and severe in DMD patients. cTnI elevation preceding cardiac dysfunction may represent an early phase of cardiomyopathy progression and may be a biomarker for early detection of cardiomyopathy in these dystrophinopathies. The ACTN3 XX genotype may be a risk factor for early myocardial injury.

Maximum Spreading of Impacting Ferrofluid Droplets under the Effect of Nonuniform Magnetic Field.

This article investigates the maximum spreading of ferrofluid droplets impacting on a hydrophobic surface under nonuniform magnetic fields. A generalized model for scaling the maximum spreading is developed. It is observed that, if the magnetic field strength is zero, a ferrofluid droplet not only demonstrates similar spreading dynamics as the water droplet but also obeys the same scaling law for the maximum spreading factor. Therefore, this article emphasizes the effects of magnetic field strength. In this regard, a dimensionless parameter (Nm) is introduced as the ratio between inertial force and Kelvin force, with an assumption that the kinetic energy mainly transforms to thermal energy. This parameter allows us to rescale all experimental data on a single curve with the Padé approximant, which is applicable to a wide range of impact velocities and magnetic field strengths.

Prognostic effects of treatment protocols for febrile convulsive status epilepticus in children.

BACKGROUND: Febrile status epilepticus is the most common form of status epilepticus in children. No previous reports compare the effectiveness of treatment strategies using fosphenytoin (fPHT) or phenobarbital (PB) and those using anesthetics as second-line anti-seizure medication for benzodiazepine-resistant convulsive status epilepticus (CSE). We aimed to examine the outcomes of various treatment strategies for febrile convulsive status epilepticus (FCSE) in a real-world setting while comparing the effects of different treatment protocols and their presence or absence. METHODS: This was a single-center historical cohort study that was divided into three periods. Patients who presented with febrile convulsive status epilepticus for ≥60 min even after the administration of at least one anticonvulsant were included. During period I (October 2002-December 2006), treatment was performed at the discretion of the attending physician, without a protocol. During period II (January 2007-February 2013), barbiturate coma therapy (BCT) was indicated for FCSE resistant to benzodiazepines. During period III (March 2013-April 2016), BCT was indicated for FCSE resistant to fPHT or PB. RESULTS: The rate of electroencephalogram monitoring was lower in period I than period II+III (11.5% vs. 85.7%, p<0.01). Midazolam was administered by continuous infusion more often in period I than period II+III (84.6% vs. 25.0%, p<0.01), whereas fPHT was administered less often in period I than period II+III (0% vs. 27.4%, p<0.01). The rate of poor outcome, which was determined using the Pediatric Cerebral Performance Category scale, was higher in period I than period II+III (23.1% vs. 7.1%, p=0.03). The rate of poor outcome did not differ between periods II and III (4.2% vs. 11.1%, p=0.40). CONCLUSIONS: While the presence of a treatment protocol for FCSE in children may improve outcomes, a treatment protocol using fPHT or PB may not be associated with better outcomes.

Epidemiological impact of universal varicella vaccination on consecutive emergency department visits for varicella and its economic impact among children in Kobe City, Japan.

INTRODUCTION: Previous studies reported a dramatic decline in the incidence of varicella and varicella-related deaths after implementing universal varicella vaccination (VarV). Although previous studies reported the effectiveness and economic impact of VarV, they were unknown in the emergency department (ED) setting. METHODS: To determine the effectiveness and economic impact of VarV in the ED, Kobe, Japan, we retrospectively reviewed the clinical database of consecutive patients younger than 16 years presenting to our primary ED from 2011 to 2019. RESULTS: Of the 265,191 children presenting to our ED, 3,092 patients were clinically diagnosed with varicella. The number of patients with varicella was approximately 500 annually, before introducing the universal two-dose VarV for children aged 1 to <3 years in October 2014, in the Japanese national immunization program, and decreased to approximately 200 in 2019. The number of patients with varicella younger than 1 year (ineligible for the vaccination) also decreased. Regarding the economic impact, the medical cost in our ED reduced after the introduction of VarV was JPY 4.1 million (US$ 40,049) annually. From the central data, approximately 95% of children were vaccinated after October 2014; however, a relatively large percentage of infected unvaccinated children (59.0%) presented to ED in this study. After the implementation of the universal VarV, infection was mainly observed in older children (i.e., the unvaccinated generation). CONCLUSIONS: Our data showed the effectiveness and economic impact of VarV in the ED setting. Additionally, our data suggested that the public vaccination program should include older unvaccinated children and other unvaccinated individuals.

Elevated cytokine, chemokine, and growth and differentiation factor-15 levels in hemorrhagic shock and encephalopathy syndrome: A retrospective observational study.

Patients with hemorrhagic shock and encephalopathy syndrome (HSES) have a high early mortality rate, which may be caused by a 'cytokine storm'. However, there is little information on how cytokines and chemokines change over time in these patients. We aimed to describe the characteristics of HSES by examining changes in serum biomarker levels over time. Six patients with HSES were included. We retrospectively evaluated their clinical course and imaging/laboratory data. We measured serum levels of multiple cytokines [interleukin 1ß (IL-1ß), IL-2, IL-4, IL-6, IL-10, IL-17, interferon-gamma, and tumor necrosis factor alpha], chemokines (IL-8, monocyte chemoattractant protein-1, interferon-inducible protein-10), and growth and differentiation factor (GDF)-15. The highest cytokine and chemokine levels were noted in the first 24 h, and decreased thereafter. The GDF-15 level was markedly high. Cytokine, chemokine, and GDF-15 levels were significantly higher in patients with HSES than in controls in the first 24 h, except for IL-2 and IL-4. Patients with HSES have high inflammatory cytokine and chemokine levels, a high GDF-15 level in the first 24 h, and high lactate levels. Our study provides new insights on the pathophysiology of HSES, a detailed clinical picture of patients with HSES, and potential biomarkers.

Rare-Earth-Mediated Optomechanical System in the Reversed Dissipation Regime.

Strain-mediated interaction between phonons and telecom photons is demonstrated using excited states of erbium ions embedded in a mechanical resonator. Owing to the extremely long-lived nature of rare-earth ions, the dissipation rate of the optical resonance falls below that of the mechanical one. Thus, a "reversed dissipation regime" is achieved in the optical frequency region. We experimentally demonstrate an optomechanical coupling rate g_{0}=2π×21.7 Hz, and numerically reveal that the interaction causes stimulated excitation of erbium ions. Numerical analyses further indicate the possibility of g_{0} exceeding the dissipation rates of erbium and mechanical systems, thereby leading to single-photon strong coupling. This strain-mediated interaction, moreover, involves the spin degree of freedom, and has a potential to be extended to highly coherent opto-electro-mechanical hybrid systems in the reversed dissipation regime.

Neuroendocrine carcinoma of the common bile duct associated with congenital bile duct dilatation: a case report.

BACKGROUND: Cholangiocarcinoma is frequently observed in patients with congenital bile duct dilatation (CBDD). Most cholangiocarcinomas are adenocarcinomas. Other types, especially neuroendocrine carcinomas (NECs), are rare. To the best of our knowledge, this is the third reported case of an NEC of the common bile duct associated with CBDD and the first to receive adjuvant chemotherapy for advanced disease. CASE PRESENTATION: A 29-year-old woman presented with upper abdominal pain. Preoperative imaging indicated marked dilatation of the common bile duct and a tumor in the middle portion of the common bile duct. She was suspected of having distal cholangiocarcinoma associated with CBDD and underwent pylorus-preserving pancreaticoduodenectomy. Pathological and immunohistological findings led to a final diagnosis of large-cell NEC (pT3aN1M0 pStageIIB). The postoperative course was uneventful, and she was administered cisplatin and irinotecan every 4 weeks (four cycles) as adjuvant chemotherapy. She has remained recurrence-free for 16 months. CONCLUSIONS: NEC might be a differential diagnosis in cases of cholangial tumor associated with congenital bile duct dilatation. This presentation is rare and valuable, and to establish better treatment for NEC, further reports are necessary.

Multivariate analysis of the impact of weather and air pollution on emergency department visits for unprovoked seizure among children: A retrospective clinical observational study.

BACKGROUND: An unprovoked seizure is a seizure or a cluster of seizures occurring within 24 h in a patient older than 1 month of age without precipitating factors. Recent studies have reported that extrinsic factors, such as meteorological conditions and air pollutants, may be important in seizure occurrence. Thus, this study aimed to examine the association between the number of visits to the emergency department (ED) by children for nighttime unprovoked seizures and exposure to multi-faceted factors, such as meteorological conditions and air pollution. METHODS: We conducted a clinical observational analysis and reviewed consecutive patients younger than 16 years of age who visited the primary ED center in Kobe City, Japan, during nighttime (7:30 p.m.-7:00 a.m.) between January 1, 2011 and December 31, 2015. We investigated the effects of meteorological factors and air pollutants on the number of patients with unprovoked seizures using multivariate analysis of Poisson regression estimates. RESULTS: In total, 151,119 children visited the ED, out of which 97 patients presented with unprovoked seizures. The mean age of the patients was 4.7 years (range, 1 month to 15.3 years), and 54.6% of them were boys. The total number of patients with unprovoked seizures showed no significant changes with the seasons; however, there were dominant peaks during the fall and fewer visits during the summer. The multivariate analysis of Poisson regression estimates revealed a significant positive relationship between the number of patients presenting with unprovoked seizures and precipitation (+1 patient/87 mm; p = 0.03) and methane (+1 patient/0.14 ppm; p = 0.03) levels and a negative relationship between the number of patients presenting with unprovoked seizures and nitrogen dioxide level (-1 patient/0.02 ppm; p = 0.04). CONCLUSIONS: The present study is the first to evaluate the association between the number of children who presented to the ED with nighttime unprovoked seizures and environmental factors after controlling for confounding factors.