Role of Vortical Structures on the Forced Convective Heat Transfer in Oscillation-Controlled Coaxial-Pipe Heat Exchanger

A numerical simulation of an oscillation-controlled heat-transport coaxial pipe is carried out for studying the flow structure and heat transport characteristics. The heat-transport pipe connects the hot and cold reservoirs, and the cold and hot fluids are discharged with the anti-phase reciprocal waves through circular and annular openings at the ends of the chamber, respectively. By changing the diameter ratio of the circular opening to the inner tube, a unidirectionally circulating flow is observed to develop spontaneously. The flow rate of the unidirectional current is found to be approximately inversely-proportional to the diameter ratio. While the amount of transported heat increases with the flow rate of the unidirectional current (especially when generating strong vortices at the edge of the inner tube) for both cases of thermally-insulated and fully-conductive inner wall, the optimal heat transport performance is attained (not in association with the strongest unidirectional flow) when making zero-averaged vorticity in the cold-end region. For the case of the conductive inner wall, the heat loss across the wall is suppressed with decreasing the diameter ratio, due to the development of the strong jet and radially surrounding shear layer that separate the outer hot fluid from the inner cold fluid.This is a pre-copyedited, author-produced PDF of an article accepted for publication in Journal of Enhanced Heat Transfer following peer review

Relationships of obesity and diabetes mellitus to other primary cancers in surgically treated gastric cancer patients

AbstractBackgroundOther primary cancers (OPC) have been reported in gastric cancer (GC) patients. Recent studies have shown relationships of obesity and diabetes mellitus to cancer development in several organs. The purpose of this study was to investigate the relationships of obesity and diabetes mellitus (DM) to the prevalence of OPC in GC patients.MethodsWe reviewed 435 GC patients who were treated surgically and followed their outcomes after surgery. Patients with body mass index (BMI) ≥ 25 kg/m2 were defined as obese. Fasting plasma glucose (FPG) and HbA1c levels were examined before surgery.ResultsOPC was observed in 109 GC patients (25.1%): 40 (9.2%) with synchronous OPC and 76 (18.2%) with metachronous OPC. The most common OPC was colorectal cancer (22.8%). OPC was frequently observed in patients with DM (p = 0.0022), and DM was an independent risk factor for the occurrence of OPC (odds ratio, 2.215; 95% confidence interval, 1.2007–4.0850; p = 0.011). Synchronous OPC was frequently observed in patients with obesity (p = 0.025), and obesity was an independent risk factor for the occurrence of synchronous OPC (odds ratio, 2.354; 95% confidence interval, 1.1246–4.9279; p = 0.023). Metachronous OPC was frequently observed in patients with DM (p = 0.0071), and DM was an independent risk factor for the occurrence of OPC (odds ratio, 2.680; 95% confidence interval, 1.0291–6.9780; p = 0.044).ConclusionThere is a need to be aware of the possibility of OPC in GC patients with DM/obesity. They should undergo intensive screening for OPC before and after gastrectomy

Association between oral condition and subjective psychological well-being among older adults attending a university hospital dental clinic: A cross-sectional study

Positive psychological well-being has a favorable impact on survival rates in both healthy and unhealthy populations. Oral health is also associated with psychological well-being, is multidimensional in nature, and includes physical, psychological, emotional, and social domains that are integral to overall health and well-being. This study aimed to identify the associations between individual and environmental characteristics, oral condition and nutritional status in relation to subjective well-being among older adults using the Wilson and Cleary conceptual model. The participants were older adults (age >= 60 years) attending a university hospital. Subjective well-being was assessed using the World Health Organization-5 Well-Being Index, oral condition was assessed based on the number of bacteria in the tongue coating, oral wettability, tongue pressure, occlusal force, oral diadochokinesis, and masticatory ability, and subjective swallowing function was assessed using the Eating Assessment Tool, number of remaining teeth, and number of functional teeth. In addition, factors related to well-being, including social networks, life-space mobility, nutritional status, smoking history, drinking history, and medical history were assessed. In the analysis, structural equation modeling was used to investigate the association between oral condition and subjective well-being. Confirmatory factor analysis revealed oral condition as a latent variable, including tongue pressure, oral diadochokinesis /pa/, /ta/, /ka/, occlusal force, masticatory ability, subjective swallowing function, and number of functional teeth. Structural Equation Modeling revealed that oral condition was positively correlated with nutritional status, and nutritional status was positively correlated with the World Health Organization-5 Well-Being Index. These findings suggest that oral condition may influence subjective well-being via nutritional status or social environmental factors

Association between the incidence of early childhood caries and attending childcare among toddlers in a rural area of Japan: a prospective cohort study

Objective The purpose of this study was to investigate the association between the incidence of early childhood caries (ECC) and factors of the daytime childcare environment among toddlers in a rural area of Japan. Material and methods This was a prospective cohort study. Data collected from 2011 to 2015 were obtained for initially caries-free, 18-month-old toddlers (N = 640). Dentists recorded the numbers of decayed, missing and filled teeth (caries incidence) of toddlers at baseline (age 18 months) and follow-up (age 3 years). In addition, a questionnaire survey was conducted on guardians at baseline to record data on lifestyle. Results In total, 159 (24.8%) toddlers had newly identified ECC at follow-up. Logistic regression analyses indicated that the incidence of ECC was significantly associated with receiving daytime care at a nursery school (odds ratio [OR], 1.55; 95% confidence interval [CI], 1.05–2.30; p = .029), prolonged breastfeeding (OR, 1.71; 95%CI, 1.15–2.55; p = .008), and snacking ≥3 times a day (OR, 2.39; 95%CI, 1.53–3.74; p  Conclusion These findings suggest that receiving daytime care at a nursery school, prolonged breastfeeding, and frequent snacking are associated with an increased risk of ECC among Japanese toddlers in rural areas

Oral Factors as Predictors of Frailty in Community-Dwelling Older People: A Prospective Cohort Study

The purpose of this prospective cohort study was to identify predictors for frailty among possible oral factors in community-dwelling older people. Ninety-seven participants (>= 60 years old) without frailty at baseline were included and assigned to either the robust or the frailty group after 2-year follow-up. The frailty was defined using the Japan Cardiovascular Health Study index. The numbers of present and functional teeth and periodontal disease severity were recorded. Bacterial counts on the dorsum of the tongue, oral moisture, tongue pressure, occlusal force, masticatory ability, and the oral diadochokinesis (ODK) rate were measured. Swallowing function, along with psychosocial status, relationships with communities and people, nutritional status, medical history, and comorbidities were evaluated using a questionnaire. The newly identified frailty group at follow-up showed significantly lower values in the number of teeth present, ODK/ta/sound and ODK/ka/sound rates, and clinical attachment level at baseline compared to the robust group. A logistic regression model showed a significantly negative association between the ODK/ta/sound rate at baseline and the incidence of frailty. Articulatory oral motor skill was found to be a predictor of frailty after two years

Faint warm debris disks around nearby bright stars explored by AKARI and IRSF

Context: Debris disks are important observational clues for understanding planetary-system formation process. In particular, faint warm debris disks may be related to late planet formation near 1 AU. A systematic search of faint warm debris disks is necessary to reveal terrestrial planet formation. Aims: Faint warm debris disks show excess emission that peaks at mid-IR wavelengths. Thus we explore debris disks using the AKARI mid-IR all-sky point source catalog (PSC), a product of the second generation unbiased IR all-sky survey. Methods : We investigate IR excess emission for 678 isolated main-sequence stars for which there are 18 micron detections in the AKARI mid-IR all-sky catalog by comparing their fluxes with the predicted fluxes of the photospheres based on optical to near-IR fluxes and model spectra. The near-IR fluxes are first taken from the 2MASS PSC. However, 286 stars with Ks<4.5 in our sample have large flux errors in the 2MASS photometry due to saturation. Thus we have measured accurate J, H, and Ks band fluxes, applying neutral density (ND) filters for Simultaneous InfraRed Imager for Unbiased Survey (SIRIUS) on IRSF, the \phi 1.4 m near-IR telescope in South Africa, and improved the flux accuracy from 14% to 1.8% on average. Results: We identified 53 debris-disk candidates including eight new detections from our sample of 678 main-sequence stars. The detection rate of debris disks for this work is ~8%, which is comparable with those in previous works by Spitzer and Herschel. Conclusion: The importance of this study is the detection of faint warm debris disks around nearby field stars. At least nine objects have a large amount of dust for their ages, which cannot be explained by the conventional steady-state collisional cascade model.Comment: 17 pages, 21 figures, accepted for publication in Astronomy and Astrophysic