Macroporous Thick Tin Foil Negative Electrode via Chemical Etching for Lithium-ion Batteries (화학적 식각을 통해 제조한 리튬이온 이차전지용 고용량 다공성 주석후막 음극)
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- Journal of the Korean Electrochemical Society
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- v.22 no.1
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- pp.36-42
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- 2019
A macroporous Sn thick film as a high capacity negative electrode for a lithium ion secondary battery was prepared by using a chemical etching method using nitric acid for a Sn film having a thickness of
Purpose: The aim of this study was to determine if preoperative temporary discontinuation of antiplatelet medication (aspirin, clopidogrel, or cilostazol) is a safe procedure that does not increase early postoperative bleeding and allogenic blood transfusion after a total knee arthroplasty. Materials and Methods: A retrospective analysis was conducted among consecutive patients who underwent navigation assisted primary total knee arthroplasty performed by a single surgeon, from January 2013 to December 2016. A total of 369 patients enrolled in this study were divided into two groups, 271 patients with no history of antiplatelet therapy and 98 patients who underwent 7 days of temporary withdrawal of antiplatelet therapy. Comparative analysis between the two groups, on the variation of hemoglobin and hematocrit during the first and second postoperative days, was conducted to determine the amount of early postoperative bleeding and the frequency of allogenic blood transfusion during hospitalization. Results: The variation of hemoglobin, hematocrit during the first and second postoperative days and the frequency of allogenic blood transfusion between no history of antiplatelet medication and discontinuation antiplatelet medication before 7 days from surgery were similar in both groups. Of the 369 patients, 149 patients received a blood transfusion during their hospitalization. Compared to patients who did not receive a blood transfusion, those who did received blood transfusion were significantly older in age, smaller in height, lighter in weight, and showed significantly lower preoperative hemoglobin and hematocrit values. No statistically significant differences in sex, preoperative American Society of Anesthesiologists scores, and the history of antiplatelet medication until 7 days prior to surgery were observed between the two groups according to blood transfusion. Conclusion: Compared to patients with no history of antiplatelet medication, the temporary discontinuation of antiplatelet medication 7 days prior to surgery in patients undergoing antiplatelet medication did not increase the amount of postoperative bleeding or the need for allogenic blood transfusion.
In this study, the mechanical stability of red mud was improved for its commercial use as a catalyst to effectively decompose HFC-134a, one of the seven major greenhouse gases. Red mud is an industrial waste discharged from aluminum production, but it can be used for the decomposition of HFC-134a. Red mud can be manufactured into a catalyst via the crushing-preparative-compression molding-firing process, and it is possible to improve the catalyst performance and secure mechanical stability through calcination. In order to determine the optimal heat treatment conditions, pellet-shaped compressed red mud samples were calcined at 300, 600, 800 ℃ using a muffle furnace for 5 hours. The mechanical stability was confirmed by the weight loss rate before and after ultra-sonication after the catalyst was immersed in distilled water. The catalyst calcined at 800 ℃ (RM 800) was found to have the best mechanical stability as well as the most catalytic activity. The catalyst performance and durability tests that were performed for 100 hours using the RM 800 catalyst showed thatmore than 99% of 1 mol% HFC-134a was degraded at 650 ℃, and no degradation in catalytic activity was observed. XRD analysis showed tri-calcium aluminate and gehlenite crystalline phases, which enhance mechanical strength and catalytic activity due to the interaction of Ca, Si, and Al after heat treatment at 800 ℃. SEM/EDS analysis of the durability tested catalysts showed no losses in active substances or shape changes due to HFC-134a abasement. Through this research, it is expected that red mud can be commercialized as a catalyst for waste refrigerant treatment due to its high economic feasibility, high decomposition efficiency and mechanical stability.
To investigate the effect of eating habits and lifestyle on the food intake of university students in Daejeon, 104 male students(26.75%) and 282 female students(73.75%) were surveyed about their food intake, eating habits, and lifestyle using the questionnaire. The major food served as breakfast was steamed rice(76.05%) and there was a little significant difference between male and female. The major food served as lunch was also steamed rice(73.77%) and male students ate it more than female ones. According to the survey, 41.95% of the subjects had breakfast regularly, and 24.35% seldom, which showed no significant difference between male and female. In case of lunch, the percentile of subjects(54.55%) who had regularly eaten lunch was more than that of breakfast, and there was a little significant difference between male and female. The survey said most subjects(49.22%) had eaten dinner irregularly, which rate was higher in male students. The meal skipped usually was the breakfast(24.35%), which rate was higher in female students. The reason why the subjects skipped the meal was mainly due to the lack of sufficient time for breakfast and lunch, and for dinner to the weight loss. Among the subjects, 80% said they were non-smokers; 96.44% in female students and 35.58% in male ones. In case of drinking, most subjects said they sometimes drank(67.19%) and the frequency of drinking was once or twice a month(51.99%), which showed the significant difference between male and female. In the aspects of effects of drinking and smoking on the food intake, the drinking practice after eating was shown to be the highest(55.98%); smoking generally affected the food intake, which showed the difference between male and female. Food intake during the examination period didn't show any differences to the usual one or increased a little bit, which showed a difference between male and female. Losing appetite during the examination period was shown mainly in the female students. When they felt blue or tired, the food intake decreased, which showed a significant difference between male and female was shown. When feeling good, the food intake significantly increased, which showed a significant difference between male and female. Therefore, there was a significant difference between male and female in the actual eating habits and in the aspects of food intake.
This study was designed to compare the nutritional intake and iron nutritional status between urban and rural middle school girls. Along with a questionnaire, blood samples were obtained from 311 middle school girls (urban 129 girls, rural 182 girls). Nutrient intakes were measured with a convenient method, and clinical symptoms relating anemia was investigated by 4-point Likert scale. For the nutrient intake, the total energy intake was 1722.2 kcal (82.0% of RDA) for the urban group and 1649.5 kcal (78.6% of RDA) for rural group. The rural group showed significantly lower level than the urban group in all nutrients except fat, carbohydrate and total energy intake. Regarding the food frequency, students from the rural group marked significantly lower intake of milk (p<0.00l), kimchi (p<0.05), fruit (p<0.05), tofu, bean (p<0.00l) than the urban group. For every clinical finding regarding anemia, the rural group marked higher value than the urban group but the difference was not significant. The hemoglobin concentration of urban group was 13.28 g/dL, and rural group showed 12.51 g/dL which was significantly lower than urban group (p<0.00l). The hematocrit rate was 37.82% for the urban group and 38.13% for the rural group and there was no significant difference between two groups. The red blood cell (RBC) count of the rural group was significantly lower than the urban group (p<0.00l). Evaluating with the iron deficiency standard which is less than 12 g/dL, the urban group was 6.2% and the rural group was 34.6% thus the deficiency rate was significantly higher in the rural group. This study showed that nutrient and iron status of the girls of rural group is not as good as the urban group. As middle school girls require high level of iron absorption due to blood loss which occurs during abrupt physical growth and menstruation, dietary counselling is required to enhance the iron status. When iron deficiency is serious, they need to take more positive action such as iron supplement in addition to food-iron fortification.
Lung cancer study group at Asan Medical Center has conducted the second prospective study to determine the efficacy and feasibility of MVP chemotherapy with concurrent hyperfractionated radiotherapy for Patients with stage III unresectable non-small cell lung cancer(NSCLC). All eligible Patients with stage III unresectable NSCLC were treated with hyperfractionated radiotherapy(120 cGy/fx BID. 6480 cGy/54fx) and concurrent 2 cycles of MVP(Mitomycin C
The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70
The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70
Background : Pulmonary aspergillomas usually arise from colonization and proliferation of Aspergillus in preexisting cavitary lung disease of any cause. About 15% of patients with tuberculous pulmonary cavities were found to have aspergilloma. We analyzed the clinical features and course of 91 patients with pulmonary aspergilloma. Method : During the ten-year period from June 1986 to May 1996, 91 patients whose condition was diagnosed as pulmonary aspergilloma at 4 university hospitals in Taegu city were reviewed. All patients fulfilled one of the following criteria : 1) histologic evidence of aspergilloma within abnormal air space in tissue sections, or 2) a positive Aspergillus serum precipitin test with the radiologic finding of a fungus ball. The histological diagno-sis was established in 81 patients(89.0%) and clinical diagnosis in 10 patients(11.0%). Results : 1) The age range was 22 to 65 years, with an average of 45 years. A male and female ratio was 1.7 : 1 (57 men and 34 women). 2) Hemoptysis was far the most frequent symptom(89%), followed by cough, dyspnea, weakness, weight loss, fever, chest pain. 3) In all but 14 cases(15.4%) there had been associated conditions. Pulmonary tuberculosis was far the most frequent underlying condition found(74.7%), followed by bronchiectasis (6.6%), cavitary neoplasm(2.2%), pulmonary sequestration(1.1%). 4) The involved area was usually in the upper lobes; the right upper lobe was involved in 39(42.9%), the left upper lobe in 31(34.1%), the left lower lobe in 13(14.3%), the right lower lobe in 7(7.7%), and the right middle lobe in 1(1.1%). 5) On standard chest roent geno gram the classic "bell-like" image of a fungus ball was found in 62.6% of the subjects. On CT scan, 88.1% of the subjects in which they were done. 6) The surgical therapy was undertaken in 76 patients, and medical therapy in 15 patients, including 4 patients with intracavitary instillation of amphotericin B. 7) The surgical modality was lobectomy in 55 patients(72.4%), segmentectomy in 16 patients(21.1%), pneumonectomy in 4 patients(5.3%), wedge resection in 1 patient(1.3%). The mortality rate was 3.9% (3 patients) ; 2 patients died of sepsis and 1 died of hemoptysis. The postoperative complications were encountered in 6 patients (7.9%), including each one patient with respiratory failure, bleeding, bronchopleural fistula, empyema, and vocal cord paralysis. 8) In the follow-up cases, each 2 patients of 71 patients with surgical treatment and 10 patients with medical treatment had recurrent hemoptysis. Conclusion : During follow-up of the chronic pulmonary disease with abnormal air space, if the standard chest roentgenograms are insufficient to detect a fungus ball, computed tomographic scan and serum precipitin test are likely to aid the diagnosis of patients with suspected pulmonary aspergilloma. A reasonable recommendation for management of a patient with aspergilloma would be to reserve surgical resection for those patients who have had severe, recurrent hemoptysis. And a well controlled cooperative study to the medical treatment such as intracavitary antifungal therapy is further needed.