Antimicrobial surface processing of polymethyl methacrylate denture base resin using a novel silica-based coating technology.

OBJECTIVES: This study investigated the surface characteristics of denture base resin coatings prepared using a novel silica-based film containing hinokitiol and assessed the effect of this coating on Candida albicans adhesion and growth. METHODS: Silica-based coating solutions (control solution; CS) and CS containing hinokitiol (CS-H) were prepared. C. albicans biofilm formed on denture base specimens coated with each solution and these uncoated specimens (control) were analyzed using colony-forming unit (CFU) assay, fluorescence microscopy, and scanning electron microscopy (SEM). Specimen surfaces were analyzed by measuring the surface roughness and wettability and with Fourier-transform infrared (FT-IR) and proton nuclear magnetic resonance (1H NMR). Stability of coated specimens was assessed via immersion in water for 1 week for each group (control-1w, CS-1w, and CS-H-1w) followed by CFU assay, measurement of surface roughness and wettability, and FT-IR. RESULTS: CS-H and CS-H-1w contained significantly lower CFUs than those present in the control and control-1w, which was also confirmed via SEM. Fluorescence microscopy from the CS-H group identified several dead cells. The values of surface roughness from coating groups were significantly less than those from the control and control-1w. The surface wettability from all coating groups exhibited high hydrophobicity. FT-IR analyses demonstrated that specimens were successfully coated, and 1H NMR analyses showed that hinokitiol was incorporated inside CS-H. CONCLUSIONS: A silica-based denture coating that incorporates hinokitiol inhibits C. albicans growth on denture. CLINICAL RELEVANCE: We provide a novel antifungal denture coating which can be helpful for the treatment of denture stomatitis.

Heavy water recycling for producing deuterium compounds.

Deuterium oxide (D2O) is a special variety of water that serves as a crucial resource in a range of applications, but it is a costly and unusual resource. We therefore developed a new D2O concentration system that combines a polymer electrolyte water electrolyzer and a catalytic combustor for recycling used D2O. In this study, 1.6 L of used D2O, with a concentration of 93.1%, was electrolyzed for 13.6 h to obtain 0.62 L of D2O, with a concentration of 99.3%. In addition, the recombined water obtained by burning electrolytic gas using the catalytic combustor was also electrolyzed for 8.8 h to obtain 0.22 L of D2O, with a concentration of 99.0%. The estimated separation factor of this electrolyzer at 25 °C was 3.6, which is very close to the equilibrium constant of the water/hydrogen isotope exchange reaction. Recycled D2O was used as a deuterium source for the deuteration reaction of sodium octanoate, and 93.6% deuterated sodium octanoate was obtained. It is concluded that there were no impurities in the recycled D2O that interfered with the deuteration reaction. These results can lead to the development of a cost-effective deuteration method for these materials.

Direct Probe of the Ferromagnetic Proximity Effect at the Interface of SnTe/Fe Heterostructure by Polarized Neutron Reflectometry.

Introducing magnetic order into a topological insulator (TI) system has attracted much attention with an expectation of realizing exotic phenomena such as the quantum anomalous Hall effect (QAHE) and axion insulator states. The magnetic proximity effect (MPE) is one of the promising schemes to induce the magnetic order on the surface of a TI without introducing disorder accompanied by doping magnetic impurities in the TI. In this study, we investigate the MPE at the interface of a heterostructure consisting of the topological crystalline insulator (TCI) SnTe and Fe by employing polarized neutron reflectometry. The ferromagnetic order penetrates ∼2.2 nm deep into the SnTe layer from the interface with Fe, which persists up to room temperature. This is induced by the MPE on the surface of the TCI preserving the coherent topological states without introducing the disorder by doping magnetic impurities. This would open up a way for realizing next-generation spintronics and quantum computational devices.

Surface Functionalization of Non-Woven Fabrics Using a Novel Silica-Resin Coating Technology: Antiviral Treatment of Non-Woven Fabric Filters in Surgical Masks.

Masks are effective for preventing the spread of COVID-19 and other respiratory infections. If antimicrobial properties can be applied to the non-woven fabric filters in masks, they can become a more effective countermeasure against human-to-human and environmental infections. We investigated the possibilities of carrying antimicrobial agents on the fiber surfaces of non-woven fabric filters by applying silica-resin coating technology, which can form silica-resin layers on such fabrics at normal temperature and pressure. Scanning electron microscopy and electron probe microanalysis showed that a silica-resin layer was formed on the fiber surface of non-woven fabric filters. Bioassays for coronavirus and quantitative reverse transcription-polymerase chain reactions (RT-PCR) revealed that all antimicrobial agents tested loaded successfully onto non-woven fabric filters without losing their inactivation effects against the human coronavirus (inhibition efficacy: >99.999%). These results indicate that this technology could be used to load a functional substance onto a non-woven fabric filter by vitrifying its surface. Silica-resin coating technology also has the potential of becoming an important breakthrough not only in the prevention of infection but also in various fields, such as prevention of building aging, protection of various cultural properties, the realization of a plastic-free society, and prevention of environmental pollution.

Protocol: Prospective observational study aiming for micro-elimination of hepatitis C virus in Nagawa town: The Nagawa Project.

BACKGROUND: The World Health Organization has set a goal of hepatitis C virus (HCV) elimination by the year 2030. However, no regions in Japan have succeeded in eradicating HCV. Micro-elimination is an approach to attain hepatitis C eradication in which national eradication goals are applied to specific populations so that viral treatment and control efforts can move forward quickly and efficiently. In order to eradicate HCV from Japan, this study aims to achieve HCV micro-elimination in the town of Nagawa. METHODS AND DESIGN: The Nagawa Project is an ongoing, prospective, multiple-institution, observational study running from April 1, 2021, to March 31, 2024. All residents of Nagawa town, excluding those under 20 years of age, not consenting to the study, or unable to undergo health check-ups due to nursing care needs, will be included. If found to be HCV antibody-positive, the participant will be recommended to see a doctor in consideration of MAC-2 binding protein glycosylation isomer values. Then, the participant will undergo serum HCV RNA measurement with the real-time polymerase chain reaction by an attending physician. If the participant is HCV RNA-positive, he or she will be referred to a hepatologist for further evaluation. In the case of a definitive diagnosis of chronic hepatitis C, direct acting antiviral treatment will be initiated. Through this process, HCV will be systematically micro-eliminated from the region. DISCUSSION: The Nagawa Project will reveal the prevalence of chronic HCV in addition to the HCV eradication rate in Nagawa town towards achieving HCV micro-elimination. TRIAL REGISTRATION: This study is performed by Shinshu University School of Medicine and was registered as UMIN 000044114 on May 6, 2021.

Fine-Structure Analysis of Perhydropolysilazane-Derived Nano Layers in Deep-Buried Condition Using Polarized Neutron Reflectometry.

A large background scattering originating from the sample matrix is a major obstacle for fine-structure analysis of a nanometric layer buried in a bulk material. As polarization analysis can decrease undesired scattering in a neutron reflectivity (NR) profile, we performed NR experiments with polarization analysis on a polypropylene (PP)/perhydropolysilazane-derived SiO2 (PDS)/Si substrate sample, having a deep-buried layer of SiO2 to elucidate the fine structure of the nano-PDS layer. This method offers unique possibilities for increasing the amplitude of the Kiessig fringes in the higher scattering vector (Qz) region of the NR profiles in the sample by decreasing the undesired background scattering. Fitting and Fourier transform analysis results of the NR data indicated that the synthesized PDS layer remained between the PP plate and Si substrate with a thickness of approximately 109 Å. Furthermore, the scattering length density of the PDS layer, obtained from the background subtracted data appeared to be more accurate than that obtained from the raw data. Although the density of the PDS layer was lower than that of natural SiO2, the PDS thin layer had adequate mechanical strength to maintain a uniform PDS layer in the depth-direction under the deep-buried condition.

Continuous Mesoporous Aluminum Oxide Film with Perpendicularly Oriented Mesopore Channels.

Mesoporous aluminum oxide (MAO) films with perpendicularly oriented cylindrical mesopores (pore diameter: ca. 10 nm) were successfully deposited on a glass substrate by a surfactant-templating approach using aluminum nitrate as an aluminum source. The perpendicular orientation of mesopores was confirmed by grazing-incidence small-angle X-ray scattering and neutron reflection experiments. The thickness of the MAO film was around 100 nm, with a surface roughness of less than 6 nm. Since the inner surface of MAO pores was positively charged, negatively charged glucose oxidase molecules could be densely loaded into the cylindrical mesopores without significant loss of enzymatic activity. The present MAO film is potentially useful as an inorganic host material for an enzyme toward the development of a biocatalytic system.

Design and characterization of a 2-(2'-hydroxyphenyl)benzimidazole-based Sr2+-selective fluorescent probe in organic and micellar solution systems.

A novel Sr2+ fluorescent probe, N-(2-hydroxy-3-(1H-benzimidazol-2-yl)-phenyl)-1-aza-18-crown-6-ether (BIC), was synthesized and its fluorescence properties, equilibria, and local structure in solution were studied in detail. The fluorescence intensity of BIC in DMSO was enhanced selectively upon addition of Sr2+ but not Na+, K+, Mg2+, Ca2+, and Ba2+. To employ this rather hydrophobic BIC probe in aqueous media, a sodium laurate (LaNa) micellar solution was used as a good solvent. The detection limit of said LaNa micelle-BIC system (2.02 µM) is lower than that of the H2O system (309 µM), but higher than that of the DMSO system (0.04 µM). Therefore, it is clear that the LaNa micelles have an effect on the detection of Sr2+ by BIC in aqueous solutions. Further structural studies by extended X-ray absorption fine structure and speciation analyses revealed that BIC undergoes complexation equilibria corresponding to the formation of [Sr(BIC)]+ species in all solution types. It was concluded that the changes in the Sr2+-BIC fluorescence in solution are attributed to the formation of such [Sr(BIC)]+ complexes.

Birch-Type Reduction of Arenes in 2-Propanol Catalyzed by Zero-Valent Iron and Platinum on Carbon.

Catalytic arene reduction was effectively realized by heating in 2-propanol/water in the presence of Pt on carbon (Pt/C) and metallic Fe. 2-Propanol acted as a hydrogen source, obviating the need for flammable (and hence, dangerous and hard-to-handle) hydrogen gas, while metallic Fe acted as an essential co-catalyst to promote reduction. The chemical states of Pt and Fe in the reaction mixture were determined by X-ray absorption near-edge structure analysis, and the obtained results were used to suggest a plausible reaction mechanism, implying that catalytic reduction involved Pt- and Fe-mediated single-electron transfer and the dehydrogenation of 2-propanol.

Controlled deuterium labelling of imidazolium ionic liquids to probe the fine structure of the electrical double layer using neutron reflectometry.

We combined the deuterium labeling and neutron reflectivity techniques to determine the fine structure of the electric double layer structure in an imidazolium ionic liquid (IL). For this, a simple and large scale deuteration method for imidazolium ILs was developed, where the deuteration level can be systematically controlled.

Usefulness of scintigraphy to predict electrical storms in severe idiopathic dilated cardiomyopathy.

BACKGROUND: Although several predictors of an electrical storm (ES) are indicated in patients with idiopathic dilated cardiomyopathy (IDCM), whether the severity of the myocardial tissue damage (SMTD) evaluated by myocardial perfusion SPECT (MPS) has an association with an ES remains unclear. The purpose of this study was to elucidate the clinical significance of SMTD for the prediction of ES in IDCM patients with an ICD. METHODS: Thirty-seven (27 men, mean age 58 ± 15 years) IDCM patients receiving ICD implantations for secondary prevention with preoperative MPS were enrolled in this study. The medical history, physical and laboratory findings, electrocardiograms, echocardiograms and MPS findings were evaluated. The SMTD was assessed by the summed scores of 17 segments using a 4-point system (0, normal ~3, severe defect). RESULTS: During a mean follow-up of 43.9 ± 30.7 months, an ES developed in 12/37 (32.4 %) patients. The SMTD score predicted an ES with a 92 % sensitivity and 56 % specificity, at a cut-off score of 10. In addition, a multivariate analysis showed that the SMTD score remained an independent predictor of an ES (HR 1.09/score 1 increase, 95 % CI 1.01-1.19, p = 0.02). The SMTD score was significantly associated with three indices of late potentials on the signal-averaged electrocardiograms, and was significantly higher in patients with positive late potentials (p = 0.0006). CONCLUSION: SMTD score assessed by MPS has a strong correlation to the late potentials and higher SMTD score may increase the risk of ES among patients with IDCM and an ICD.

Incessant monomorphic ventricular tachycardia induced by the proarrhythmic effect of amiodarone.

This case report describes incessant monomorphic ventricular tachycardia (VT), not torsade de pointes, induced by intravenous amiodarone in a 48-year-old woman with dilated cardiomyopathy. VT was reproducibly triggered by short coupled premature ventricular complex (PVC) with different morphology from VT. After amiodarone infusion, the coupling interval of initiating PVC was prolonged, and moreover, the morphology of initiating PVC became the same as that of VT. Though amiodarone has become the first line drug to treat ventricular tachyarrhythmias in patients with cardiac dysfunction, it is important to be aware of its proarrhythmic effect, which may lead to an electrical storm of monomorphic VT.

Clinical characteristics of focal atrial tachycardias arising from the atrial appendages during childhood.

BACKGROUND: Focal atrial tachycardias (ATs) arising from the atrial appendages (AAT) are uncommon in adults. On the other hand, we frequently encounter AATs during childhood. However, the topographic distribution and clinical characteristics of focal ATs during childhood have not yet been clearly revealed. The aim of this study was to investigate the clinical characteristics of AATs in childhood. METHODS: The study population consisted of 16 consecutive pediatric patients with focal AT enrolled between March 1991 and June 2009. A retrospective analysis was performed. The patients with focal AT were divided into two groups: the AAT group and other AT (OAT) group, in which the foci arose from other atrial sites. RESULTS: Fifty percent had AAT. The AAT patients consisted of more males (88% vs 25%; P < 0.05), were more often asymptomatic at the initial visit (75% vs 25%; P < 0.05), and more often presented with an incessant form of the AT (88% vs 25%; P < 0.05) than the OAT patients. Second-degree atrioventricular block during slow ATs of <120 beats per minute were more often observed in the AAT patients (63% vs 13%; P < 0.05). The incidence of tachycardia-mediated cardiomyopathy was 19% out of all our subjects and 38% of the AAT patients. CONCLUSIONS: The AATs are the major source of focal ATs in pediatric patients that are typically incessant. These characteristics probably explain why a much higher percentage of the patients are presented with TMC.

Augmented ST-segment elevation during recovery from exercise predicts cardiac events in patients with Brugada syndrome.

OBJECTIVES: The goal of this study was to evaluate the prevalence and the clinical significance of ST-segment elevation during recovery from exercise testing. BACKGROUND: During recovery from exercise testing, ST-segment elevation is reported in some patients with Brugada syndrome (BrS). METHODS: Treadmill exercise testing was conducted for 93 patients (91 men), 46 ± 14 years of age, with BrS (22 documented ventricular fibrillation, 35 syncope alone, and 36 asymptomatic); and for 102 healthy control subjects (97 men), 46 ± 17 years of age. Patients were routinely followed up. The clinical end point was defined as the occurrence of sudden cardiac death, ventricular fibrillation, or sustained ventricular tachyarrhythmia. RESULTS: Augmentation of ST-segment elevation ≥0.05 mV in V(1) to V(3) leads compared with baseline was observed at early recovery (1 to 4 min at recovery) in 34 BrS patients (37% [group 1]), but was not observed in the remaining 59 BrS patients (63% [group 2]) or in the 102 control subjects. During 76 ± 38 months of follow-up, ventricular fibrillation occurred more frequently in group 1 (15 of 34, 44%) than in group 2 (10 of 59, 17%; p = 0.004). Multivariate Cox regression analysis showed that in addition to previous episodes of ventricular fibrillation (p = 0.005), augmentation of ST-segment elevation at early recovery was a significant and independent predictor for cardiac events (p = 0.007), especially among patients with history of syncope alone (6 of 12 [50%] in group 1 vs. 3 of 23 [13%] in group 2) and among asymptomatic patients (3 of 15 [20%] in group 1 vs. 0 of 21 [0%] in group 2). CONCLUSIONS: Augmentation of ST-segment elevation during recovery from exercise testing was specific in patients with BrS, and can be a predictor of poor prognosis, especially for patients with syncope alone and for asymptomatic patients.

Clinical effect of implantable cardioverter defibrillator replacements: when should you resume driving after an implantable cardioverter defibrillator replacement?

BACKGROUND: The intervals of the driving restrictions after an implantable cardioverter defibrillator (ICD) replacement vary across the different countries around the world. However, little is known regarding the appropriate duration for driving restrictions after an ICD replacement. The aim of this study was to investigate the clinical effect of ICD replacements and to elucidate when to resume driving an automobile after an ICD replacement. METHODS AND RESULTS: The study reviewed 139 consecutive patients with an ICD replacement in order to evaluate the incidence of ICD therapies before and after ICD replacements, and to assess the time-dependence of the ICD therapies after the ICD replacement. There was no significant difference in the incidence of ICD therapies delivered during durations of 3 months and 6 months before and after the ICD replacement (P=0.28, and 1.0, respectively). ICD therapies after the replacements were observed in 8.6% of the patients who were legally eligible to drive according to the Japanese guidelines at 1 year, and that was associated with a relatively low annual risk of death or injury to others. CONCLUSIONS: Implantable cardioverter defibrillator replacements did not affect the future ICD therapies under similar algorithms. The appropriate interval for driving restrictions after an ICD replacement is recommended to be a week or so, with a system integrity check performed before resumption of driving.

Predictors of electrical storm in patients with idiopathic dilated cardiomyopathy--how to stratify the risk of electrical storm.

BACKGROUND: Electrical storm (ES) is a serious problem in patients with an implantable cardioverter defibrillator (ICD). However, insufficient reports have indicated the predictors of ES in ICD patients with idiopathic dilated cardiomyopathy (DCM). The purpose of this study was to clarify the predictors of ES for risk stratification in DCM patients with an ICD. METHODS AND RESULTS: Of 446 ICD patients, 53 DCM patients were included in this study. During a mean follow-up of 55+/-36 months, ES (> or =3 times appropriate ICD therapy within 24 h) occurred in 18/53 (34%) patients. According to multivariate Cox proportional hazard regression analysis, a duration of the terminal low amplitude signals of <40 microV (LAS40) (HR 1.4/10 ms increase, 95% confidence interval (CI) 1.1-2.1; P=0.0049) or root mean square voltage of the last 40 ms of the QRS complex (RMS40) (HR 0.88/1 microV, 95%CI 0.77-0.96; P=0.001) on the signal averaged electrocardiogram, and a history of atrial fibrillation (AF) before ICD implantation (HR 2.3, 95%CI 1.2-5.0; P=0.013) were independently associated with an increased risk of ES. CONCLUSIONS: Our data indicated that a longer LAS40, lower RMS40 and history of AF before ICD implantation could strongly predict ES, and the combination of those parameters could effectively stratify the risk of ES in DCM patients.

Relationship between oral amiodarone and inappropriate therapy from an implantable cardioverter defibrillator.

BACKGROUND: This study evaluated the efficacy of amiodarone for avoiding inappropriate therapies by implantable cardioverter defibrillators (ICDs). METHODS AND RESULTS: A total of 232 patients with structural heart disease (58+/-13 years; 78% males) who underwent an initial ICD implantation were retrospectively investigated to compare baseline characteristics and event rates of inappropriate ICD therapy delivery between patients with oral amiodarone therapy (amiodarone group, n=116) and those without (non-amiodarone group, n=116). During a mean follow-up of 29+/-21 months, inappropriate therapies occurred less frequently in the amiodarone group than in the non-amiodarone group (12% vs 27%, P=0.0068). As a cause of inappropriate ICD therapy, only atrial fibrillation (AF) significantly differed between the groups (3% vs 12%, P=0.01). The results of multivariate logistic regression analysis showed that amiodarone therapy (odds ratio (OR) 0.38, 95% confidence interval (CI) 0.19-0.77, P=0.0073) and no history of spontaneous AF (OR 0.27, 95%CI 0.13-0.57, P=0.0007) were independent predictors of a lower risk of inappropriate ICD therapy. CONCLUSIONS: In the present group of ICD patients with structural heart disease, inappropriate therapy delivery occurred predominantly in those with spontaneous AF and/or without amiodarone.

The positional relationship between the coronary sinus musculature and the atrioventricular septal junction.

AIMS: The atrioventricular (AV) septal junction includes the coronary sinus (CS) and the compact part of the AV node and its posterior extensions. It has been recognized as the target site for ablation therapy of the AV nodal reentrant tachycardia and its variant forms. Despite the clinical significance of this region, the arrangement of the musculature in the AV septal junction, including the CS, has not fully been elucidated. We tried to explore the histological muscular diversity within the AV septal junction. METHODS AND RESULTS: Sixteen autopsied human hearts (seven women), mean age 59.8 years, without structural anomalies, were studied. We removed the whole AV septum, including the CS opening after the macroscopic measurements, and prepared serial sections parallel to mitral and tricuspid annuli (short-axis style) to elucidate the positional relationships between the compact AV node and the CS musculature. Out of 16 hearts, the CS musculature extended deeply into the AV septal junction in eight hearts. In the other eight hearts, the CS musculature was located above the AV septal junction. In the former group, we found that the offset of both annuli was wide (mean 3.8 +/- 1.4 vs. 2.4 +/- 1.1 mm), the distance between CS opening and membranous septum was long (mean 14.8 +/- 1.6 vs. 12.3 +/- 2.2 mm), and the CS opening level was lower and closer to the His bundle level (mean 2.8 +/- 1.9 vs. 5.8 +/- 2.9 mm) (P < 0.05). CONCLUSION: The deep extension of CS musculature into the AV septal junction seems to increase the tissue non-uniformity in this area.

Radiofrequency catheter ablation of parasystole originating from the inferior vena cava.

A 76-year-old man with a history of atrial septal defect repair underwent radiofrequency (RF) ablation of typical atrial flutter. During electrophysiological study, incessant sharp potentials were recorded, originating from the ostium of the inferior vena cava (IVC), and dissociated from atrial activity. During sinus rhythm, these potentials propagated to the atria and caused premature complexes when falling beyond the atrial refractory period. Electro-anatomical mapping revealed the presence of the earliest potential in the postero-lateral ostium of the IVC, propagating to the septal region. After RF isolation of the IVC, the patient has remained arrhythmia-free over a 5-year follow-up.

Neurally mediated syncope as a cause of syncope in patients with Brugada electrocardiogram.

INTRODUCTION: Patients with type 1 Brugada electrocardiogram (ECG) and an episode of syncope are diagnosed as symptomatic Brugada syndrome; however, all episodes of syncope may not be due to ventricular tachyarrhythmia. METHODS AND RESULTS: Forty-six patients with type 1 Brugada ECG (all males, 51 +/- 13 years, 29 spontaneous, 17 Ic-drug induced), 20 healthy control subjects (all males, 35 +/- 11 years), and 15 patients with suspected neurally mediated syncope (NMS; 9 males, 54 +/- 22 years) underwent the head-up tilt (HUT) test. During the HUT test, 12-lead ECGs were recorded in all patients, and the heart rate variability was investigated in some patients. Sixteen (35%) of 46 patients with Brugada ECG, 2 (10%) of 20 control subjects, and 10 (67%) of 15 patients with suspected NMS showed positive responses to the HUT test. Although no significant differences were observed in HUT-positive rate among Brugada patients with documented VT (7/14; 50%), syncope (5/19; 26%) and asymptomatic patients (4/13; 31%), the HUT-positive rate was significantly higher in patients with documented VT (50%) and those with VT or no symptoms (11/27, 41%) compared to that in control subjects (10%) (P < 0.05). Augmentation of ST-segment amplitude (> or =0.05 mV) in leads V1-V3 was observed in 11 (69%) of 16 HUT-positive patients with Brugada ECG during vasovagal responses, and was associated with augmentation of parasympathetic tone following sympathetic withdrawal. CONCLUSION: Thirty-five percent of patients with Brugada ECG showed vasovagal responses during the HUT test, suggesting that some Brugada patients have impaired balance of autonomic nervous system, which may relate to their syncopal episodes.