Background, aim, and scope Feedstock recycling has received attention as an effective method to recycle waste plastics. However, estimating the reduction potential by life cycle assessment using coke oven and blast furnace in steel works has been a challenging task due to the complex structure of energy flow in steel works. Municipal waste plastics consist of several plastic resins. Previous studies have generally disregarded the composition of waste plastics, which varies significantly depending on the geographical area. If the reduction potentials by using each plastic resin in steel works can be quantified, the potential of municipal waste plastics (mixtures of plastic resins) can be estimated by summing up the potential of each resin multiplied by the composition of each resin in municipal waste plastics. Therefore, the goal of this study is to investigate the reduction potentials of CO 2 emissions by using individual plastic resins (polyethylene (PE), polypropylene (PP), polystyrene (PS), polyethylene terephthalate (PET)) and those for municipal waste plastics in the coke oven and blast furnace. Materials and methods A model was developed to clarify the energy flow in steel works. In order to estimate the changes in energy and material balance in coke ovens when waste plastics are charged, the equations to calculate the coke product yield, gas product yield, and oil product yields of each plastic resin were derived from previous studies. The Rist model was adopted to quantify the changes in the inputs and outputs when plastics were fed into a blast furnace. Then, a matrix calculation method was used to calculate the change in energy balance before and after plastics are fed into a coke oven. Results It was confirmed that product yields of municipal waste plastics (mixtures of plastic resins) could be estimated by summing up the product yield of each plastic resin multiplied by the composition of each resin in municipal waste plastics. In both cases of coke oven and blast furnace feedstock recycling, the reduction potential of CO 2 emissions varies significantly depending on the plastic resins. For example, in the case of coke oven chemical feedstock recycling, the reduction potential of PS and PP is larger than that of PE. On the other hand, in the case of blast furnace feedstock recycling, PE has the largest CO 2 emissions reduction potential, whereas the CO 2 emission reduction potential of PP is smaller than those of PE and PS. In both cases, PET has negative CO 2 emission reduction potentials, i.e., there is an increase of CO 2 emissions. In addition, the reduction potentials of CO 2 emissions are slightly different in each city. Discussions The differences in the reduction potentials of CO 2 emissions by coke oven chemical feedstock recycling of each plastic resin is attributable to the differences in calorific values and coke product yields of each plastic resin. On the other hand, the difference in the CO 2 emission reduction potential for each plastic resin in blast furnace feedstock recycling is att...
To examine physical activity at work and during leisure-time as well as other factors related to blood pressure (BP) in Japanese-Americans living in Hilo, Hawaii, USA, we performed a population-based cross-sectional study with a sample of 238 participants aged 42-64 years old. This survey was carried out between 19 February and 1 March 2000 in Hilo. All participants were invited to Hilo Medical Center for a free physical examination and experimental tests including an examination of blood and urine samples. A self-administered health questionnaire was used that included items related to demographics, smoking, alcohol consumption, and habitual physical activity at work and during leisure-time. A summary score of physical activity (PA) was calculated. BP was measured using an automated BP measurement system (Khi machine, VINE Co., Ltd., Kyoto, Japan). The results showed the following. 1) Mean (SD) PA scores at work (WPA) and during leisure-time (LTPA) were 2.9 (0.5) and 2.5 (0.5) in men, and 3.0 (0.5) and 2.4 (0.3) in women, respectively; 2) Pearson correlation analyses (adjustment for age) indicated that WPA and LTPA in men show significant negative associations with SBP and DBP (p<0.05 and p<0.01), while LTPA shows significant negative associations with SBP and DBP in women (p<0.05 and p<0.01). After further adjustment for education, occupation, smoking, and alcohol consumption status, LTPA continued to show significant and negative associations with both SBP and DBP in men (p<0.01) and with DBP alone in women (p <0.01). 3) Hypertensive subjects had significantly lower mean LTPA scores than normotensive men (2.39 vs. 2.61, p<0.05) and women (2.32 vs. 2.45, p<0.05). 4) Body mass index and the ratio of sodium to potassium excretion showed significant and positive associations with SBP and DBP in multiple linear regression analyses. In conclusion, the results further emphasize that the health benefits of LTPA, control of body weight, and reduction in salt intake should continually receive strong attention in population-based high BP control.
In the past decade, it has increasingly been reported that epigallocatechin-3-gallate (EGCG), a major catechin derivative extracted from Green tea, has various bioactivities, including a cell-protective action on mammalian cells and tissues. In this study, we have tested a commercial preservation solution containing EGCG (Theliokeep(®)) in both two- and three-dimensional cultures of human periosteal sheets, which have been used as an osteogenic grafting material for periodontal regenerative therapy. When periosteal sheets were 3D-cultured on collagen mesh, cell viability was maintained for 2 days using the hypothermic EGCG preservation solution. Replenishment of EGCG solution with 2-day intervals prevented the time-dependent decline in cell viability at 3 days and later. As observed in nonpreserved control cultures, most cells were positive for proliferating cell-nuclear antigen (PCNA) in the cultures preserved at 4°C in the EGCG solution, whereas PCNA-negative cells were increased in the cultures preserved at 4°C in the MesenPRO medium. In periosteal sheets 2D-cultured in plastic dishes, the EGCG solution occasionally was associated with vacuole formation in the cytoplasm, but cells could again expand in the culture medium at 37°C. As observed in the nonpreserved periosteal sheets control, the osteogenic induction upregulated alkaline phosphatase in those cells and tissues preserved in the EGCG solution. The EGCG solution protected cells from the cold shock-induced membrane phospholipid peroxidation. Our data suggest that the EGCG solution acts as an antioxidant to protect periosteal cells from cold shock and preserves cells under chilled conditions. The limited period of preservation time could be expanded by repeating replenishment of the EGCG solution or by optimizing the formula to be more favorable for human periosteal sheets without sacrificing cell viability. This methodology of preserving human cultured periosteal sheets with EGCG would be expected to support and spread the clinical use of regenerative therapy with autologous periosteal sheets.
Background and objectives: The safety of electrohydraulic lithotripsy (EHL) in older adults remains unclear. We aimed to investigate the efficacy and safety of EHL using peroral cholangioscopy (POCS) under endoscopic retrograde cholangiopancreatography (ERCP) guidance in older adults aged ≥80 years. Materials and Methods: This retrospective clinical study was conducted at a single center. Fifty patients with common bile duct stones who underwent EHL using POCS under ERCP guidance at our institution, between April 2017 and September 2022, were enrolled in this study. The eligible patients were divided into an elderly group (n = 21, age ≥80 years) and a non-elderly group (n = 29, age ≤79 years), and were analyzed. Results: A total of 33 and 40 EHL procedures were performed in the elderly and non-elderly groups, respectively. After excluding cases in which stone removal was performed at other institutions, complete removal of common bile duct stones was confirmed in 93.8% and 100% of the elderly and non-elderly groups, respectively (p = 0.20). The mean number of ERCPs required for complete removal of bile duct stones was 2.9 and 4.3 in the elderly and non-elderly groups, respectively (p = 0.17). In the EHL session, the overall occurrence of adverse events was eight and seven in the elderly (24.2%) and non-elderly (17.5%) groups, respectively; however, the difference was insignificant (p = 0.48). Conclusions: EHL using POCS under ERCP guidance is effective in patients aged ≥80 years and there was no significant increase in adverse event rates compared to those aged ≤79 years.
A 64-year-old woman was diagnosed with emphysematous cholecystitis. An open cholecystectomy was performed immediately. After the cholecystectomy, jaundice and multiple bile duct strictures that were not present preoperatively appeared. The patient was diagnosed with sclerosing cholangitis secondary to emphysematous cholecystitis. Endoscopic biliary stenting and endoscopic biliary balloon dilatation were performed. However, jaundice did not improve. She developed candidemia 75 days after cholecystectomy. The patient died of multiple organ failures 92 days after cholecystectomy. Although rare, secondary sclerosing cholangitis occurred after emphysematous cholecystitis, and endoscopic treatment was ineffective in this case.
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