Calorimetric thermoelectric gas sensor for the detection of hydrogen, methane and mixed gases.

A novel miniaturized calorimeter-type sensor device with a dual-catalyst structure was fabricated by integrating different catalysts on the hot (Pd/θ-Al2O3) and cold (Pt/α-Al2O3) ends of the device. The device comprises a calorimeter with a thermoelectric gas sensor (calorimetric-TGS), combining catalytic combustion and thermoelectric technologies. Its response for a model fuel gas of hydrogen and methane was investigated with various combustor catalyst compositions. The calorimetric-TGS devices detected H2, CH4, and a mixture of the two with concentrations ranging between 200 and 2000 ppm at temperatures of 100-400 °C, in terms of the calorie content of the gases. It was necessary to reduce the much higher response voltage of the TGS to H2 compared to CH4. We enhanced the H2 combustion on the cold side so that the temperature differences and response voltages to H2 were reduced. The device response to H2 combustion was reduced by 50% by controlling the Pt concentration in the Pt/α-Al2O3 catalyst on the cold side to 3 wt%.

A novel synthesized tyrosinase inhibitor: (E)-2-((2,4-dihydroxyphenyl)diazenyl)phenyl 4-methylbenzenesulfonate as an azo-resveratrol analog.

We synthesized a novel series of (E)-2-((substituted phenyl)diazenyl)phenyl 4-methylbenzenesulfonate derivatives (2 and 3) and (E)-2-((substituted phenyl)diazenyl)phenol derivatives (4 and 5), and conducted an evaluation in order to determine their inhibitory effects on mushroom tyrosinase, with the aim of discovering a tyrosinase inhibitor. Most of the compounds (3-5) exhibited higher inhibitory effects than kojic acid (IC(50) = 49.08 µM), a representative tyrosinase inhibitor. A novel synthesized compound, (E)-2-((2,4-dihydroxyphenyl)diazenyl)phenyl 4-methylbenzenesulfonate (3), showed the best results with an IC(50) of 17.85 µM, and showed competitive inhibition on Lineweaver-Burk plots, as further confirmed by the docking results. In addition, active compounds 3-5 were not cytotoxic to cultured B16F10 cells at the concentrations tested, and inhibited both tyrosinase and melanin synthesis. Therefore the active compounds (3-5) might be considered excellent candidates for use in the development of therapeutic agents for diseases associated with hyperpigmentation.

Asymptomatic ruptured sinus of valsalva aneurysm combined with perimembranous ventricular septal defect, and bicuspid aortic valve in adult patient.

We report the case of an adult patient with the unusual combination of a perimembranous (PM) ventricular septal defect (VSD), asymptomatic ruptured sinus of Valsalva communicating with the right ventricle, and a bicuspid aortic valve. Bulged sinus of Valsalva might conceal the small PM VSD, therefore the patient had no symptom-associated VSD until grown up. However, when aortic valve regurgitation associated with prolapsed right aortic cusp worsened and ruptured sinus of Valsalva was found by echocardiogram, the patient underwent aortic valve replacement with anatomical surgical correction of the aortic sinus and VSD.

Impact of home-based exercise training with wireless monitoring on patients with acute coronary syndrome undergoing percutaneous coronary intervention.

Recent studies have suggested a favorable effect of cardiac rehabilitation (CR) on patients with cardiovascular disease. This study aimed to evaluate the impact of home-based exercise training with wireless monitoring on acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI). A total of 55 ACS patients undergoing PCI were randomly divided into home based exercise training with wireless monitoring cardiac rehabilitation (CR, n = 26) and usual care (UC, n = 29). Exercise capacity and quality of life (QOL) were evaluated at baseline and after 12 weeks. Change of metabolic equivalent of the tasks, maximal exercise time and QOL were significantly increased (+2.47 vs +1.43, P = 0.021; +169.68 vs +88.31 sec, P = 0.012; and +4.81 vs +0.89, P = 0.022, respectively), and the change of submaximal rate pressure product, and of submaximal rate of perceived exertion were significantly decreased (-28.24 vs -16.21, P = 0.013; and -1.92 vs -1.62, P = 0.018, respectively) in the CR group compared to the UC group after 12 weeks. CR using home-based exercise training with wireless monitoring led to improvement of exercise capacity and QOL relative to conventional care in ACS patients undergoing PCI. Our findings suggest that early scheduled CR may be considered in ACS patients undergoing PCI.

The antibacterial activity of various saturated and unsaturated fatty acids against several oral pathogens.

The antibacterial activity of various saturated fatty acids (SFA) and unsaturated fatty acids (USFA) against different oral pathogens which are implicated in the cause of dental caries, stomatitis, gingivitis, and periodontitis was examined. The saturated fatty acids Pa, StA and ArA, and the unsaturated omega-7 fatty acids PLA and omega-9 fatty acids OA showed either none to low antimicrobial activity against all of the 12 oral pathogenic strains used in this study. In contrast, the omega-3 PUFAs, ALA, SDA, EPA and DHA, and the omega-6 PUFAs, LA, GLA, and AA showed considerable antimicrobial activity against 8, 7, 6 and 5 strains, and 6, 10 and 5 strains, respectively. In particular, the omega-3 and omega-6 PUFAs showed strong antimicrobial activity against Porphyromonas gingivalis KCTC 381, the cause of periodontitis, and against Aggregatibacter segnis KCTC 5968, Fusobacterium nucleatum subsp. Polymorphum KCTC 5172 and Prevotella intermedia KCTC 25611, all organisms implicated in the cause of gingivitis. To date, no bacterial resistance to free fatty acids has been encountered and no resistance phenotype has emerged. Therefore, these results suggest that PUFAs may be useful in the development of therapeutic agents for oral diseases, and in particular, in the development of agents that have minimal side effects and against which there is no bacterial resistance.

Type 2 diabetes in urban and rural districts in Korea: factors associated with prevalence difference.

The purpose of this study was to examine the urban-rural differences in the prevalence and associated factors with type 2 diabetes mellitus (T2DM) in Korean adults. A total of 1,060 adults >30 yr of age from urban (189 males and 331 females) and rural districts (219 males and 321 females) were recruited. Anthropometric measures, blood pressure, lipid profiles, and fasting and 2-hr after 75-g oral glucose load blood glucose were obtained. The crude- and age-standardized prevalence of T2DM was 15.4% and 14.5%, and 11.7% and 8.6% in urban and rural districts, respectively. Diabetic subjects were older and obese, and had a higher triglyceride level, and systolic blood pressure compared to non-diabetes in both population. Multivariate regression analysis revealed that older age, high triglyceride levels, central obesity, and hypertension were significantly associated with T2DM in both areas. Low monthly incomes were significantly associated with T2DM in urban population, while a family history of T2DM was significantly associated with T2DM in rural area. T2DM is more prevalent in urban than in rural population, and low economic status or genetic factor is differently associated with T2DM in both population, respectively.

The effects of medication adherence and health literacy on health-related quality of life in older people with hypertension.

AIM AND OBJECTIVE: This study investigated the effects of medication adherence and health literacy on health-related quality of life in vulnerable older people with hypertension. BACKGROUND: Health literacy is particularly critical for providing accurate information regarding correct medication intake to improve medication adherence. Additionally, health-related quality of life is directly related to impairment from chronic disease. DESIGN: A descriptive, cross-sectional study design was used. The participants were 160 low-income older people with hypertension registered in 16 public health centres in Busan, South Korea. They had received "visiting nursing services" for at least 6 months until the latest date and had belonged to the priority group of visiting nursing services. METHODS: The Morisky Medication Adherence Scale, the Newest Vital Signs and EuroQol-5 Dimensions were used to assess medication adherence, health literacy and health-related quality of life, respectively. RESULTS: Medication adherence and health literacy were significantly associated with health-related quality of life in vulnerable older people with hypertension, although exercise and subjective health were more significant factors affecting health-related quality of life than medical adherence and health literacy. Level of education, monthly income and employment status were not associated with health-related quality of life. CONCLUSIONS: To effectively promote health-related quality of life in this population, medication adherence and health literacy of patients should be considered when developing health interventions, including subjective health and exercise. IMPLICATIONS FOR PRACTICE: To effectively promote health-related quality of life in vulnerable older people, medication adherence and health literacy of patients should be assessed, and patient-centred intervention strategies that consider their individual differences should be developed.

Effects of the weight management program based self-efficacy for body composition, blood lipid profile, weight self-efficacy lifestyles, depression in middle-aged obese women.

PURPOSE: This study was done to determine the effects of weight management program using self-efficacy in middle-aged obese women. The study also attempted to measure the effects of the program on the weight efficacy lifestyle, body composition, and depression. METHOD: The research design of this study was a nonequivalent control group pretest-posttest design. The experimental group consisted of 21 middle-aged obese women and another 21 middle-aged obese women in the control group. The women in the experimental group participated in the weight management program for 12 weeks using self-efficacy. The weight management program using self-efficacy included education on effects of exercise for weight control, aerobic exercise program, muscle training and counseling through the telephone. RESULTS: After 12 weeks of participation in the program, BMI (p<.0001), body fat % (p<.0001), abdominal fat (p<.0001), in the experimental group were significantly decreased compared to the control group. Weight self-efficacy lifestyle (p<.0001) and depression (p=.006) in the experimental group were significantly improved after the program compared to the control group. According to these findings, weight management program self-efficacy for middle-aged obese women could increase weight efficacy lifestyle, and decrease depression, BMI, body fat, and abdominal fat. CONCLUSION: The result also suggested that the increasing weight efficacy and lifestyle help the obese women to perform and continue exercise. This program could be used in the community such as public health center for weight care and mental health promotion of middle-aged obese women.

[A comparative study on family perception between abused children and normal children by Kinetic Family Drawing].

PURPOSE: The study attempted to find family perception differences between abused children and normal children by Kinetic Family Drawing. METHOD: The subjects of the study consisted of two groups, 143 abused who were in the upper 25th percentile, and 150 normal who were in the lower 25th percentile. Collected Kinetic Family Drawings were divided into five dimensions such as actions, human figure characteristics, dynamics, styles and symbols, and they was analyzed with SPSS/WIN 10.0. RESULTS: In the perception about their family in action dimension, their family in figure characteristics dimension, their family in dynamics dimensions, and their family in symbols dimension, there is a sharp contrast between the two groups. CONCLUSION: Putting these results together, abused children feel lower self-esteem and feel more sense of alienation in their family than normal children do. In addition, abused children perceive their parents as negative and aggressive people.

Process of change, decisional balance, self-efficacy and depression across the stages of change for exercise among middle aged women in Korea.

PURPOSE: The purpose of this study was to differentiate the change in exercise behavior into different stages and to investigate differences in the process of change, self efficacy, decisional balances and depression according to the stages of exercise behavior change among middle aged women in Korea by using the transtheoretical Model. METHODS: A convenience sample of 434 middle aged women (40-64 years) completed measures of all transtheoretical model constructs involved in exercise behaviors (stages and processes of exercise behaviors change, self efficacy and decisional balance) and depression. The data were analyzed by using the SPSS 10.0 program including descriptive statistics, and one-way ANOVA. RESULTS: The subjects were distributed in each stage of change in exercise behaviors: pre-contemplation (n=106; 24.4%), contemplation (n=126; 29%), preparation (n=88; 20.3%), action (n=51; 11.8%), and maintenance (n=63; 14.5%). The processes of change, pros(advantages of behaviors), self-efficacy and depression were significantly differentiated across the stages of exercise behavior change. Cons(disadvantage of behaviors) was not significantly differentiated across the stages of exercise behavior change. CONCLUSIONS: Results of this study suggested that discriminating of processes of change, self-efficacy, decisional balance, and depression could provide positive information to people about the stages of change in exercise behavior. Therefore, in designing interventions, the stage of a client's exercise behaviors change needs to be assessed prior to application of intervention programs in order to increase and maintain exercise behavior in middle aged women.

Atrial standstill in suspected isolated cardiac sarcoidosis.

Most of the abnormal cardiac conduction system findings are atrial tachyarrhythmias in cardiac sarcoidosis. However, atrial standstill as a sick-sinus syndrome could be complicated in the case of diffuse atrial fibrosis. Herein, we present an interesting and valuable case of atrial standstill with suspected isolated cardiac sarcoidosis. .

Imbalance in Cardiovascular Surgery Medical Service Use Between Regions.

BACKGROUND: This study uses the relevance index to understand the condition of regional medical service use for cardiovascular surgery and to identify the medical service use imbalance between regions. METHODS: This study calculated the relevance index of 16 metropolitan cities and provinces using resident registration address data from the Ministry of Government Administration and Home Affairs and the 2010-2014 health insurance, medical care assistance, and medical benefits claims data from the Health Insurance Review and Assessment Service. We identified developments over the 5-year time period and analyzed the level of regional imbalance regarding cardiovascular surgery through the relative comparison of relevance indexes between cardiovascular and other types of surgery. RESULTS: The relevance index was high in large cities such as Seoul, Daegu, and Gwangju, but low in regions that were geographically far from the capital area, such as the Gangwon and Jeju areas. Relevance indexes also fell as the years passed. Cardiovascular surgery has a relatively low relevance index compared to key types of surgery of other fields, such as neurosurgery and colorectal surgery. CONCLUSION: This study identified medical service use imbalance between regions for cardiovascular surgery. Results of this study demonstrate the need for political intervention to enhance the accessibility of necessary special treatment, such as cardiovascular surgery.

The Association Between Treatment Frequency and Treatment Outcome for Cardiovascular Surgeries.

BACKGROUND: This study analyzed the association between the volume of heart surgeries and treatment outcomes for hospitals in the last five years. METHODS: Hospitals that perform heart surgeries were chosen throughout Korea as subjects using from the Health Insurance Review and Assessment Service. The treatment outcome of the heart surgeries was defined as the mortality within 30 postoperative days, while the annual volume of the surgeries was categorized. Logistic regression was used as the statistical analysis method, and the impacts of the variables on the heart surgery treatment outcomes were then analyzed. RESULTS: The chance of death of patients who received surgery in a hospital that performed 50 or more surgeries annually was noticeably lower than patients receiving operations from hospitals that performed fewer than 50 surgeries annually, indicating that the chance of death decreases as the annual volume of heart surgeries in the hospital increases. In particular, the mortality rate in hospitals that performed more than 200 surgeries annually was less than half of that in hospitals that performed 49 or fewer surgeries annually. CONCLUSION: These results indicate that accumulation of a certain level of heart surgery experience is critical in improving or maintaining the quality of heart surgeries. In order to improve the treatment outcomes of small hospitals, a support policy must be implemented that allows for cooperation with experienced professionals.

Projections of Demand for Cardiovascular Surgery and Supply of Surgeons.

BACKGROUND: While demand for cardiovascular surgery is expected to increase gradually along with the rapid increase in cardiovascular diseases with respect to the aging population, the supply of thoracic and cardiovascular surgeons has been continuously decreasing over the past 10 years. Consequently, this study aims to achieve guidance in establishing health care policy by analyzing the supply and demand for cardiovascular surgeries in the medical service area of Korea. METHODS: After investigating the actual number of cardiovascular surgeries performed using the National Health Insurance claim data of the Health Insurance Review and Assessment Service, as well as drawing from national statistics concerning the elderly population aged 65 and over, this study estimated the number of future cardiovascular surgeries by using a cell-based model. To be able to analyze the supply and demand of surgeons, the recent status of new surgeons specializing in thoracic and cardiovascular surgeries and the ratio of their subspecialties in cardiovascular surgeries were investigated. Then, while taking three different scenarios into account, the number of cardiovascular surgeons expected be working in 5-year periods was projected. RESULTS: The number of cardiovascular surgeries, which was recorded at 10,581 cases in 2014, is predicted to increase consistently to reach a demand of 15,501 cases in 2040-an increase of 46.5%. There was a total of 245 cardiovascular surgeons at work in 2014. Looking at 5 year spans in the future, the number of surgeons expected to be supplied in 2040 is 184, to retire is 249, and expected to be working is 309-an increase of -24.9%, 1.6%, and 26.1%, respectively compared to those in 2014. This forecasts a demand-supply imbalance in every scenario. CONCLUSION: Cardiovascular surgeons are the most central resource in the medical service of highly specialized cardiovascular surgeries, and fostering the surgeons requires much time, effort, and resources; therefore, by analyzing the various factors affecting the supply of cardiovascular surgeons, an active intervention of policies can be prescribed for the areas that have failed to meet the appropriate market distributions.

Development of Models for Regional Cardiac Surgery Centers.

BACKGROUND: This study aimed to develop the models for regional cardiac surgery centers, which take regional characteristics into consideration, as a policy measure that could alleviate the concentration of cardiac surgery in the metropolitan area and enhance the accessibility for patients who reside in the regions. METHODS: To develop the models and set standards for the necessary personnel and facilities for the initial management plan, we held workshops, debates, and conference meetings with various experts. RESULTS: After partitioning the plan into two parts (the operational autonomy and the functional comprehensiveness), three models were developed: the 'independent regional cardiac surgery center' model, the 'satellite cardiac surgery center within hospitals' model, and the 'extended cardiac surgery department within hospitals' model. Proposals on personnel and facility management for each of the models were also presented. A regional cardiac surgery center model that could be applied to each treatment area was proposed, which was developed based on the anticipated demand for cardiac surgery. The independent model or the satellite model was proposed for Chungcheong, Jeolla, North Gyeongsang, and South Gyeongsang area, where more than 500 cardiac surgeries are performed annually. The extended model was proposed as most effective for the Gangwon and Jeju area, where more than 200 cardiac surgeries are performed annually. CONCLUSION: The operation of regional cardiac surgery centers with high caliber professionals and quality resources such as optimal equipment and facility size, should enhance regional healthcare accessibility and the quality of cardiac surgery in South Korea.

Rapid Synthesis and Formation Mechanism of Core-Shell-Structured La-Doped SrTiO3 with a Nb-Doped Shell.

To provide a convenient and practical synthesis process for metal ion doping on the surface of nanoparticles in an assembled nanostructure, core-shell-structured La-doped SrTiO3 nanocubes with a Nb-doped surface layer were synthesized via a rapid synthesis combining a rapid sol-precipitation and hydrothermal process. The La-doped SrTiO3 nanocubes were formed at room temperature by a rapid dissolution of NaOH pellets during the rapid sol-precipitation process, and the Nb-doped surface (shell) along with Nb-rich edges formed on the core nanocubes via the hydrothermal process. The formation mechanism of the core-shell-structured nanocubes and their shape evolution as a function of the Nb doping level were investigated. The synthesized core-shell-structured nanocubes could be arranged face-to-face on a SiO2/Si substrate by a slow evaporation process, and this nanostructured 10 µm thick thin film showed a smooth surface.

Surgical outcome of the maze procedure for atrial fibrillation in mitral valve disease: rheumatic versus degenerative.

BACKGROUND: The results of the maze procedure are known to be less satisfactory in rheumatic mitral disease than in nonrheumatic mitral valve disease. The aim of this study was to determine whether the etiology of mitral valve disease affected surgical outcome. METHODS: From July 1997 to January 2001, 129 consecutive patients with chronic atrial fibrillation associated with mitral valve disease had mitral valve operations with the maze procedure. The underlying mitral pathology was rheumatic in 86 patients (group R) and degenerative in 43 (group D). Echocardiograms and electrocardiograms were performed immediately and then repeated 3 months and 6 months postoperatively. RESULTS: The mean age, duration of atrial fibrillation, and preoperative left atrial size were similar between the groups. There was no operative mortality and no significant difference in cardiopulmonary bypass and aortic cross-clamp times. The sinus conversion rate at 7 days postoperatively was 86% in both groups, and at 6 months it was 95.3% in group R and 97.7% in group D (p > 0.05). The transmitral A wave detection rates in groups R and D at 7 days and 6 months postoperatively were, respectively, 63.1% versus 67.4% and 90.4% versus 91.9% (p > 0.05). The transmitral A wave velocity (cm/second) at the same times (7 days and 6 months postoperatively) was 41.9 +/- 41.6 versus 45.5 +/- 37.7 and 67.8 +/- 38.2 versus 69.8 +/- 35.8 in groups R and D, respectively (p > 0.05). CONCLUSIONS: The maze procedure is equally effective in treating chronic atrial fibrillation in patients with either rheumatic or nonrheumatic mitral valve disease in terms of sinus conversion rate and left atrial transport function.

Excellent results for atrial fibrillation surgery in the presence of giant left atrium and mitral valve disease.

OBJECTIVE: The incidence of sinus conversion in the enlarged left atrium after atrial fibrillation surgery is reported to be low. The purpose of the current study was to investigate the effects of atrial fibrillation surgery on mitral valve disease associated with a giant left atrium (GLA). METHOD: From July of 1997 to February of 2002, 188 patients received mitral valve and atrial fibrillation surgery. The patients were placed in either GLA group (n = 94), or NGLA group (n = 94), based on LA size. The presence and onset of sinus rhythm and the incidence and velocity of transmitral A waves were monitored during the early postoperative period and throughout the follow up period of 42 months. RESULTS: The onset of postoperative sinus rhythm was slightly earlier in the NGLA group than in the GLA group at 1.3+/-0.4 days versus 3.1+/-1.2 days, respectively, (P = 0.008). The sinus conversion rates in the GLA and the NGLA groups were 91.5 and 97.9% in the early postoperative period, and 94.7 and 95.7% at 6 months after surgery, respectively. A wave appearance rates in the early postoperative period in the GLA and the NGLA groups were 62.2 and 71.7%, and continued to improve over time to 94 and 95% by 36 months, respectively. Peak A wave velocities in the early postoperative period in GLA and NGLA groups were 67.4+/-34.0 and 61.1+/-29.5 cm/s without significant change during the follow up. CONCLUSION: The results suggest that atrial fibrillation surgery is effective at inducing sinus rhythm and restoring left atrial contractile function after concomitant mitral valve surgery regardless of LA size.

Heart transplantation. A retrospective analysis of the long-term results.

Long-term results of orthotopic heart transplantation vary among different institutions. The purpose of the present study was to assess the factors, which might affect long-term survival and complications. Between November 1992 and July 2003, 112 heart transplantations (M/F=89:23) were performed. The standard technique was used in the first 57 patients and the bicaval technique in the latter 55 patients. Indications for transplantation in decreasing order of frequency were dilated cardiomyopathy (75%), ischemic cardiomyopathy (7%), and others (18%). The mean follow up duration was 51.8 +/- 31.3 months with 98 patients remaining alive. Preoperatively, all patients were either in NYHA functional class III or IV. Postoperatively, all patients showed improvement to functional class II or I, except 3 patients that remained in NYHA class III. The mean number of rejection cases within the first year was 0.6 +/- 0.8, with humoral rejection noted in 3 cases. The graft vascular disease (GVD)-free survival at 3 and 5 years was 96% and 83%, respectively. The 7-year survival after heart transplantation was 84%. There were 16 deaths, of which infection (n=4) was the most common followed by rejection (n=3), and malignancy (n=2). The present long-term results, were relatively superior to those seen in western countries. The relatively low GVD-free survival rate is thought to have contributed. The complications encountered after transplantation were mostly immunosuppressive drug related, suggesting further potentials for improvement in long-term survival.