〈Original Papers〉Diurnal and seasonal variation of air temperature profile in the mountain forest at Sugadaira, central Japan

Air temperature profiles were observed for a year with micro-climate observation in and around the mixed mountain forest. The shading effects of tree crown, depending on the solar elevation angle and abscission of broad leaf species, controlled the diurnal and seasonal variation of radiation budget and temperature gradients in the forest. Vertical mixing of air in the forest was infrequent even the wind speed over the forest was high. Sasa albo-marginata served as another important daytime heat source at the forest floor in snow-free season. In the forest, weak but clear diurnal wind variation was observed on fair summer days indicating prevailing of daytime up-slope winds and nocturnal gravity currents. After leaf abscission, the nocturnal temperature inversion prevailed in and out of the forest. The importance of the local winds blowing through the forest and their effect on the data from the station in an open space are discussed with regard to the long-term assessment of mountain meteorological and forest phonological data

Risk of chronic periodontitis in patients with obstructive sleep apnea in Korea: a nationwide retrospective cohort study

OBJECTIVES The aim of this study was to determine whether the development of chronic periodontitis is more likely among patients who have been newly diagnosed with obstructive sleep apnea (OSA) through an analysis of representative data from the general population. METHODS A nationwide, population-based, retrospective cohort study was conducted using patient records from the Korean National Health Insurance Service database. For the period 2004-2019, patient data were categorized into 2 groups: a diagnosis of OSA (747 subjects) and no diagnosis of OSA (1,494 subjects). Subsequently, 1:2 propensity score matching was performed to ensure the homogeneity of the 2 groups. To analyze the risk of incident chronic periodontitis, a Cox proportional-hazards model was used to calculate hazard ratios (HRs) with 95% confidence intervals (CIs). RESULTS In the Kaplan-Meier curve, the disease-free probability was significantly lower in the OSA group than in the non-OSA group (p for log-rank test=0.001). The crude HR for the association between OSA and chronic periodontitis was 1.29 (95% CI, 1.16 to 1.43). The multivariable-adjusted HR was calculated at 1.28 (95% CI, 1.15 to 1.42). CONCLUSIONS This study confirmed a relationship between OSA and chronic periodontitis. Therefore, OSA patients require oral care to prevent the progression of chronic periodontitis from mild to severe

The risk of stroke according to statin medication compliance in older people with chronic periodontitis: an analysis using the Korea National Health Insurance Service-Senior Cohort Database

OBJECTIVES We investigated the risk of stroke according to statin medication compliance in older people with chronic periodontitis. METHODS Chronic periodontitis patients were extracted from the National Health Insurance Service-Senior Cohort Database from 2002 to 2014. Among 255,056 chronic periodontitis patients, 41,412 patients with statin prescriptions for 28 days or more were included. The study population was divided into the top 25% of medication compliance group (TSG) and the lower 25% of medication compliance group (BSG). After 1:1 propensity score matching was performed, the final number of patients in the BSG and TSG was 6,172 each. To analyze the risk of stroke, a Cox proportional hazard model was performed to calculate hazard ratios (HRs) and 95% confidence intervals (95% CIs) after adjusting for age, sex, income level, hypertension, diabetes, and Charlson comorbidity index. RESULTS In the Kaplan-Meier curve, the disease-free probability was prominently lower in the BSG than in the TSG (p for log-rank= 0.001). The HR in the multivariable-adjusted model for stroke occurrence in the TSG compared to the BSG was 0.79 (95% CI, 0.67 to 0.92; p=0.002). Subgroup analyses showed significant associations between compliance to statin medication and stroke, especially in female, people 85 years or older, and patients with comorbidities. CONCLUSIONS Increasing compliance to statins may reduce stroke risk in older adults with chronic periodontitis. Therefore, in order to increase medication compliance among older people with chronic periodontitis, it is necessary for medical staff to make efforts to provide effective medication guidance

Risk of dementia according to the severity of chronic periodontitis in Korea: a nationwide retrospective cohort study

OBJECTIVES We investigated the risk of dementia in older adults with chronic periodontitis according to the severity of periodontitis. METHODS Data on patients with chronic periodontitis were extracted from the National Health Insurance Service-Senior cohort database from 2002 to 2014. Among 52,728 subjects eligible for inclusion, 11,953 subjects had newly diagnosed mild chronic periodontitis (MCP), and 40,775 subjects had newly diagnosed severe chronic periodontitis (SCP). Two 1:1 propensity score matched cohorts were created with 8,624 patients each in the MCP and SCP groups. To analyze the risk of dementia, a Cox proportional-hazard model was used to calculate hazard ratios with 95% confidence intervals (CIs). RESULTS In the Kaplan-Meier curve, the disease-free probability was significantly lower in the SCP group than in the MCP group (p for log-rank=0.001). In the multivariable-adjusted model, the HR for the occurrence of dementia in the SCP group compared to the MCP group was 1.15 (95% CI, 1.04 to 1.27; p=0.009). A subgroup analysis revealed a significant association between dementia and the severity of periodontitis, especially in subjects who were male, aged ≥70 years, and had comorbidities. CONCLUSIONS Reducing the severity of chronic periodontitis can help to reduce the risk of dementia. Therefore, it is necessary to aggressively conduct early dementia-prevention programs for males under the age of 70 that include dental health to prevent the progression of periodontitis from mild to severe

Long-Term Survival and Kidney Function in Pediatric Patients Following Liver Transplantation: A 15-Year Retrospective Cohort Study

Long-term preservation of kidney function after liver transplantation (LT) has not been well studied. We thus evaluated the rates of kidney function preservation and long-term survival after pediatric LT. We also investigated the risk factors associated with the progression of chronic kidney disease (CKD). We conducted a retrospective study of 184 pediatric patients who had undergone LT from 2003 to 2018 at a university hospital. We collected demographics, primary indications for LT, liver disease scores, renal function test results, immunosuppressive drug prescriptions, and diagnosis of post-LT complications. The 15-year survival rate was 90.8%. Furthermore, the rate of kidney function preservation at 14 years post-LT in patients at high risk of renal disease was 79.3%, and that in those with less risk of kidney diseases was 96.0%. Arterial hypertension was an independent risk factor associated with CKD progression. However, when arterial hypertension was excluded, the use of cyclosporine and liver disease with renal involvement were risk factors for CKD progression. We found that kidney function after pediatric LT was well preserved. We encourage the early detection of underlying kidney involvement, routine monitoring of renal function for high-risk patients, active control of hypertension, and appropriate immunosuppressive regimens for pediatric patients with LT

Effect of technology convergence for tablet PC on potential environmental impacts from heavy metals

<p>The technology convergence integrating multiple devices into a single one is now a distinct trend in electronic industry. This trend can lead to a decrease in the use of rare and toxic heavy metals due to resource sharing, or an increase due to the application of new and auxiliary technology. This study investigates the effect of technology convergence for tablet PC on hazardous waste, resource depletion, and toxicity potentials from heavy metals in electronic devices, considering how many single devices (i.e., netbook computer, electronic dictionary, mp3 player, digital camera, cell phone, and vehicle GPS system) can be displaced by a tablet PC depending on users. The hazardous waste potential from heavy metals is examined with existing U.S. federal and California state regulations, and the resource depletion and toxicity potentials from heavy metals are evaluated based on life cycle impact assessments. The potentials of a specific tablet PC are compared to the total of those of displaced single products. Overall, the tablet PC has lower hazardous waste, resource depletion, and toxicity potentials from heavy metals. However, in case the tablet PC displaces only two or three single devices, it requires more gold, molybdenum, and vanadium. Therefore, technology convergence should take into account materials consumption and user behavior to develop more sustainable products.</p

A Comparative Immunohistochemical Study of Wound Healing after Dental Diode Laser Treatment in the Rat Oral Mucosa

This study aimed to examine the differences in healing patterns using two types of diode laser devices (laser A and laser B) and a steel scalpel for periodontal surgery through histological and immunohistochemical methods. Twenty 12-week-old male rats were assigned to three groups (3, 7, and 14 days). Square-shaped erosion wounds (2 &times; 2 mm2 diameter) were created on the hard palate of each rat. Two wounds were created using Laser A and a steel scalpel (Bard-Parker No. 15) on the right palate and using Laser B and a steel scalpel on the left side. Rats were sacrificed after 3, 7, and 14 days. Tissues were collected with a margin of 1 mm from the border of the erosional wound of the maxillary hard palate. Histological and immunohistochemical analyses were performed on the tissue samples after 3, 7, and 14 days. The tissue healing pattern and expression of inducible nitric oxide synthase (iNOS) and cluster of differentiation (CD) were observed under a light microscope. Statistical analysis was conducted using the Kruskal&ndash;Wallis H test for comparison among the groups (&alpha; = 0.05). In comparison to the wounds made with the scalpel, wounds treated with lasers A and B showed delayed healing patterns. There was no significant difference between the two laser treatment groups (p &gt; 0.05). The expression of iNOS and CD68 was not significantly different among the three groups after 3 and 7 days (p &gt; 0.05). On day 14, the groups treated with the dental diode lasers showed higher expression than the group treated with the steel scalpel, but no significant difference was observed (p &gt; 0.05). Laser-induced wounds tended to heal slower than surgical wounds performed using a steel scalpel, but histological and immunohistochemical results showed no significant difference between the dental diode laser and scalpel groups