N\'eel-Dimer Transition in Antiferromagnetic Heisenberg Model and Deconfinement of Spinons at the Critical Point

Quantum phase transition from the N\'eel to the dimer states in an antiferromagnetic(AF) Heisenberg model on square lattice is studied. We introduce a control parameter $\alpha$ for the exchange coupling which connects the N\'eel ($\alpha=0$) and the dimer ($\alpha=1$) states. We employ the $CP^1$ (the Schwinger boson) representation of the $s={1\over 2}$ spin operator and integrate out the half of the $CP^1$ variables at odd sites and we obtain a $CP^1$ nonlinear $\sigma$ model. The effective coupling constant is a function of $\alpha$ and at $\alpha=0$ the $CP^1$ model is in the ordered phase which corresponds to the N\'eel state of the AF Heisenberg model. A phase transition to the dimer state occurs at a certain critical value of $\alpha_C$ as $\alpha$ increases. In the N\'eel state, the dynamical composite U(1) gauge field in the $CP^1$ model is in a Higgs phase and low-energy excitations are gapless spin wave. In the dimer phase, a confinement phase of the gauge theory is realized and low-energy excitations are $s=1$ magnons. For the critical point, we argue that a deconfinement phase, which is similar to the Coulomb phase in 3 spatial dimensions, is realized and $s={1\over 2}$ spinons appear as low-energy excitations

A Mixed Optimal Control Approach for Upstream Fish Migration

This paper proposes a simple mathematical model forupstream fish migration along rivers. The model describes the fish migration along a river based on a mixed optimal control approach having swimming velocity, school size, and stopping time of migration as control variables. The optimization problem reduces to a variational inequality. Its explicit “viscosity” solution is presented with the dependence of the fish migration on river environment. To prove uniqueness of the solution to the variational inequality requires a constructive argument not based on the conventional theorems. A novel finite difference scheme for solving the variational inequality is also proposed with its convergence results. An application example of the model discusses the upstream migration of Plecoglossus altivelis (Ayu) in Japan, which evaluates the dependence of the fish migration on the habitat quality and provides recommendations for managing river environment. This is an interdisciplinary research between environmental and mathematical fields

Successful surgical resection of infected left atrial myxoma in a case complicated with disseminated intravascular coagulation and multiple cerebral infarctions: case report

Cardiac myxoma is the most common primary cardiac tumour, but infected cardiac myxoma is relatively rare. Infected cardiac myxoma is very fragile, and has a potential to lead to catastrophic disorder with systemic bacteremia, systemic mycotic embolism, and disseminated intravascular coagulation (DIC)

A Review of Evidence for a Therapeutic Application of Traditional Japanese Kampo Medicine for Oral Diseases/Disorders

Kampo medicines prescribed by specialized medical practitioners and Japanese physicians have gradually reemerged in Japan as alternatives to Western medications. Kampo formulations are composed of several plant extracts and, as such, the broad variety of phytochemicals they contain likely act synergistically to provide their beneficial effects. Kampo medicines have traditionally been prescribed for a number of health conditions, including chronic hepatitis, bronchial asthma, anemia, etc. The aim of this article is to review the beneficial effects of Kampos with respect to oral health. Pertinent papers published between 1970 and 2017 were retrieved by searching in PubMed, ScienceDirect, Web of Science, and Scopus using key words followed by evaluation of the relevant articles. In vitro studies have identified a number of properties that give credence to the potential of Kampos for treating or preventing oral diseases/disorders. Given their anti-microbial and anti-inflammatory properties, they may be promising agents for controlling periodontal diseases, oral mucositis, xerostomia, and drug-induced gingival overgrowth. Since some oral diseases have a complex etiology that involves microbial pathogens and the host immune response, agents with dual functionality such as Kampo phytochemicals may offer a therapeutic advantage

Effectiveness of an oral care tablet containing kiwifruit powder in reducing oral bacteria in tongue coating : A crossover trial

Objectives: The aim of this study was to investigate the effect of an oral care tablet containing kiwifruit powder on oral bacteria in tongue coating compared with tongue brushing. Material and methods: Thirty‐two healthy, young adults were enrolled, and a crossover clinical trial was conducted. The volatile sulfur compound (VSC) concentration, Winkel tongue‐coating index (WTCI), and the number of total bacteria in addition to Fusobacterium nucleatum in tongue coating were measured. We instructed subjects to remove tongue coating by tongue brush for Intervention I, to keep the oral care tablet containing kiwifruit powder on the tongue dorsum and to let it dissolve naturally for Intervention II, and three oral care tablets 1 day before the measurement for Intervention III. Results: There were significant differences in terms of the level of H2S, VSC, and WTCI at Intervention I and all evaluation values at Intervention II. There were significant differences in terms of the level of H2S, VSC, WTCI, the number of total bacteria, and F. nucleatum at Intervention III. The value of WTCI, the number of bacteria, and F. nucleatum decreased significantly after taking the oral care tablets than after tongue brushing. When compared with Interventions I and III, Intervention III showed the effective results; there were significant differences in the number of total bacteria and F. nucleatum between tongue brushing and taking tablets. Conclusions: These results suggested that the oral care tablet containing kiwifruit powder could be effective in reducing total bacteria and F. nucleatum in tongue coating when compared with tongue brushing

Central venous pulse pressure analysis using an R-synchronized pressure measurement system

Objective. The information derived from central venous catheters is underused. We developed an EKG-R synchronization and averaging system to obtained distinct CVP waveforms and analyzed components of these. Methods. Twenty-five paralyzed surgical patients undergoing CVP monitoring under mechanical ventilation were studied. CVP and EKG signals were analyzed employing our system, the mean CVP and CVP at end-diastole during expiration were compared, and CVP waveform components were measured using this system. Results. CVP waveforms were clearly visualized in all patients. They showed the a peak to be 1.8+/- 0.7 mmHg, which was the highest of three peaks, and the x trough to be lower than the y trough (-1.6+/- 0.7mmHgand-0.9+/- 0.5mmHg, respectively), with a mean pulse pressure of 3.4mm Hg.The difference between the mean CVP and CVP at end-diastole during expiration was 0.58+/- 0.81 mmHg. Conclusions. The mean CVP can be used as an index of right ventricular preload in patients under mechanical ventilation with regular sinus rhythm. Our newly developed system is useful for clinical monitoring and for education in circulatory physiology

Oral care tablet containing kiwifruit powder affects tongue coating microbiome

Objectives: Tongue coating, a kind of biofilm formed on the tongue dorsum, is the cause of various clinical conditions, such as oral halitosis and periodontal diseases, because Fusobacterium nucleatum acts as a bridge between other oral bacteria and periodontopathogenic bacteria in biofilm formation. Our previous clinical study revealed that taking oral care tablets containing kiwifruit powder significantly reduced not only tongue‐coating index and volatile sulfur compounds but also total bacteria and F. nucleatum in tongue coating. In this study, we analyzed the microbiome of tongue coating samples obtained before and after oral care tablets intake to clarify whether this tablet is a useful tool for daily tongue care. Methods: Thirty‐two healthy young adults were enrolled, and a crossover clinical trial was conducted. We instructed subjects to remove tongue coating by tongue brush for intervention I, to keep the oral care tablet containing kiwifruit powder on the tongue dorsum and to let it dissolve naturally for intervention II. Microbial DNA was isolated from the collected tongue coating samples in each subject, then 16S rRNA next‐generation sequencing, operational taxonomic unit clustering, and statistical analysis were performed. Results: The microbiome analysis revealed that the oral care tablet in intervention II prompted a significant change in the tongue microbiota composition, a significant reduction in the relative abundance of Prevotella and Porphyromonas, and an increase in Firmicutes/Bacteroidetes ratio when compared to that in intervention I. Conclusion: These results suggested that the oral care tablet might contribute to the improvement of the oral condition due to its good influence on the tongue coating microbiome

Current status of collaborative relationships between dialysis facilities and dental facilities in Japan : results of a nationwide survey

Background: Recent studies have reported an association between periodontal disease and mortality among dialysis patients. Therefore, preventive dental care should be considered very important for this population. In Japan, no systematic education has been undertaken regarding the importance of preventive dental care for hemodialysis patients—even though these individuals tend to have oral and dental problems. The aim of this study was to investigate the current state of collaborative relationships between hemodialysis facilities and dental services in Japan and also to identify strategies to encourage preventive dental visits among hemodialysis outpatients. Methods: A nationwide questionnaire on the collaborative relationship between dialysis facilities and dental facilities was sent by mail to all medical facilities in Japan offering outpatient hemodialysis treatment. Results: Responses were obtained from 1414 of 4014 facilities (35.2%). Among the 1414 facilities, 272 (19.2%) had a dental service department. Approximately 100,000 dialysis outpatients were receiving treatment at these participating facilities, which amounts to one-third of all dialysis patients in Japan. Of those patients, 82.9% received hemodialysis at medical facilities without dental departments. Only 87 of 454 small clinics without in-house dental departments (19.2%) had collaborative registered dental clinics. Medical facilities with registered dental clinics demonstrated a significantly more proactive attitude to routine collaboration on dental matters than facilities lacking such clinics. Conclusions: Our nationwide survey revealed that most dialysis facilities in Japan have neither an in-house dental department nor a collaborative relationship with a registered dental clinic. Registration of dental clinics appears to promote collaboration with dental facilities on a routine basis, which would be beneficial for oral health management in hemodialysis patients