944 research outputs found

    Estimates of Discharge Coefficient in Levee Breach Under Two Different Approach Flow Types

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    The amount of released water (discharge) in a levee breach is a primary input variable to establish an emergency action plan for the area next to the levee. However, although several studies have been conducted, there is still no widely applicable discharge coefficient formula; this needs to be known to estimate discharge amount through an opening caused by a levee breach. Sometimes, the discharge coefficient developed for a sharp crested side weir is used to rate the discharge, but, in case of a levee breach, the resulting geometry and flow types are similar to that over a broad crested weir. Thus, in this study, two different openingsā€”rectangular and trapezoidal shapeā€”are constructed in the center of a levee at a height of 0.6m to replicate levee breach scenarios, and the effect of two different approach flow typesā€”the river type approach and reservoir type approachā€”are explored to suggest a discharge coefficient formula applicable for discharge rating for a levee breach. The results show that the ratio of head above the bottom of an opening and the opening width is a key variable for calculating the discharge coefficient of a reservoir type, but the approach Froude number should also be considered for a river type approach. The measured data are used to improve rating equations and will be useful in the future to validate computational fluid dynamics simulations of wave propagation during levee failure into the inundation area

    miRNA regulation of cytotoxic effects in mouse Sertoli cells exposed to nonylphenol

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    Background: It is known that some environmental chemicals affect the human endocrine system. The harmful effects of endocrine disrupting chemical (EDC) nonylphenol (NP) have been studied since the 1980s. It is known that NP adversely affects physiological functions by mimicking the natural hormone 17 beta-estradiol. In the present study, we analyzed the expression of miRNAs and their target genes in mouse Sertoli TM4 cells to better understand the regulatory roles of miRNAs on Sertoli cells after NP exposure. Methods: Mouse TM4 Sertoli cells were treated with NP for 3 or 24 h, and global gene and miRNA expression were analyzed using Agilent mouse whole genome and mouse miRNA v13 arrays. Results: We identified genes that were > 2-fold differentially expressed in NP-treated cells and control cells (P < 0.05) and analyzed their functions through Gene Ontology analysis. We also identified miRNAs that were differentially expressed in NP-treated and control cells. Of the 186 miRNAs the expression of which differed between NP-treated and control cells, 59 and 147 miRNAs exhibited 1.3-fold increased or decreased expression at 3 and 24 h, respectively. Network analysis of deregulated miRNAs suggested that Ppara may regulate the expression of certain miRNAs, including miR-378, miR-125a-3p miR-20a, miR-203, and miR-101a, after exposure to NP. Additionally, comprehensive analysis of predicted target genes for miRNAs showed that the expression of genes with roles in cell proliferation, the cell cycle, and cell death were regulated by miRNA in NP-treated TM4 cells. Levels of expression of the miRNAs miR-135a* and miR-199a-5p were validated by qRT-PCR. Finally, miR-135a* target gene analysis suggests that the generation of reactive oxygen species (ROS) following exposure to NP exposure may be mediated by miR-135a* through regulation of the Wnt/beta-catenin signaling pathway. Conclusions: Collectively, these data help to determine NP's actions on mouse TM4 Sertoli cells and increase our understanding of the molecular mechanisms underlying the adverse effects of xenoestrogens on the reproductive system.This work was supported an Eco-Technopia 21 project grant from the Ministry of Environment (Development of Decision Method of Chromosomal Abnormality in Reproductive System by Toxic Substances at the Korea Institute of Toxicology)

    Bone-Loading Physical Activity and Alcohol Intake but not BMI Affect Areal Bone Mineral Density in Young College-Aged Korean Women: A Cross-Sectional Study.

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    The purpose of this cross-sectional study was to determine the differences in areal bone mineral density (aBMD) based on alcohol consumption behaviors, bone-loading history as assessed by a bone-specific physical activity questionnaire (BPAQ), and the body mass index (BMI). College-aged female students (N = 112) were recruited from the universities in Seoul and Gyeonggi province, South Korea. The aBMD of the lumbar spine and non-dominant side of the proximal femur (total hip, TH; femoral neck, FN; femoral trochanter, FT) were measured using dual energy X-ray absorptiometry (DXA). Alcohol consumption was determined by the frequency and amount of alcohol intake during the past 12 months using a self-reported questionnaire. The X-scan plus II was used to measure height (cm), body mass (kg), fat-free mass (FFM, kg), and % body fat. Drinking two or more times alcohol per week was associated with greater aBMD of the TH (p = 0.04ā€“0.002) and FN (p = 0.043) compared to a lower frequency of alcohol consumption and 2ā€“4 times per month, respectively. Based on the drinking amount per occasion, there were no significant group differences (p \u3e 0.05) in aBMD at any of the sites. The highest group of total BPAQ had greater aBMD of the TH, FN, and FT versus the lowest (p = 0.023ā€“0.009) and mid of total BPAQ groups (p = 0.004ā€“0.009). Additionally, the highest group had greater aBMD of the lumbar spine compared to the mid group (p = 0.001). No significant group differences in aBMD at any of the sites were noted based on the BMI (p \u3e 0.05). Young college-aged women with greater bone-loading physical activity showed greater aBMD at the TH, FN, FT, and lumbar spine, while a moderate alcohol intake was associated with greater aBMD of the TH and FN. These findings have clinical implications for young women who may not participate in high-impact physical activity and are binge drinkers

    A Score-Based Evaluation Model for Rehabilitation of Existing Pumped Storage Hydropower Plant Construction

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    As the proportion of new and renewable energy increases, power control demands are becoming more frequent due to variability in power generation. As a complementary means against this, the pumped storage hydropower plants (PSHP) are attracting attention as energy storage systems (ESS), but it has high construction costs. Therefore, this study aims to improve the economic feasibility by developing the evaluation model of the existing infrastructure into an upper/lower dam suitable for PSHP. The concept of upper dam capacity is newly defined, and the evaluation index is constructed using normalization. A new evaluation system is presented for five factors: environment, stability, energy, capacity, and economy. Finally, it is tested in the pilot area in Korea. Several candidates, including the PSHP in operation, are found to have been distributed with higher scores. These results will help to satisfy the selection of candidates during the preliminary feasibility study phase, and programming them will enable more accurate and rapid assessment

    Clinical and Pathological Characteristics of Four Korean Patients with Limb-Girdle Muscular Dystrophy type 2B

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    Limb-girdle muscular dystrophy type 2B (LGMD2B), a subtype of autosomal recessive limb-girdle muscular dystrophy (ARLGMD), is characterized by a relatively late onset and slow progressive course. LGMD2B is known to be caused by the loss of the dysferlin protein at sarcolemma in muscle fibers. In this study, the clinical and pathological characteristics of Korean LGMD2B patients were investigated. Seventeen patients with ARLGMD underwent muscle biopsy and the histochemical examination was performed. For the immunocytochemistry, a set of antibodies against dystrophin, Ī±, Ī², Ī³, Ī“-sarcoglycans, dysferlin, caveolin-3, and Ī²-dystroglycan was used. Four patients (24%) showed selective loss of immunoreactivity against dysferlin at the sarcolemma on the muscle specimens. Therefore, they were classified into the LGMD2B category. The age at the onset of disease ranged from 9 yr to 33 yr, and none of the patients was wheelchair bound at the neurological examination. The serum creatine kinase (CK) was high in all the patients (4010-5310 IU/L). The pathologic examination showed mild to moderate dystrophic features. These are the first Korean LGMD2B cases with a dysferlin deficiency confirmed by immunocytochemistry. The clinical, pathological, and immunocytochemical findings of the patients with LGMD2B in this study were in accordance with those of other previous reports

    Impact of Controlling Nutritional Status score on short-term outcomes after carotid endarterectomy: a retrospective cohort study

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    Background Malnutrition and impaired immune responses significantly affect the clinical outcomes of patients with atherosclerotic stenosis. The Controlling Nutritional Status (CONUT) score has recently been utilized to evaluate perioperative immunonutritional status. This study aimed to evaluate the relationship between immunonutritional status, indexed by CONUT score, and postoperative complications in patients undergoing carotid endarterectomy (CEA). Methods We retrospectively evaluated 188 patients who underwent elective CEA between January 2010 and December 2019. The preoperative CONUT score was calculated as the sum of the serum albumin concentration, total cholesterol level, and total lymphocyte count. The primary outcome was postoperative complications within 30 days after CEA, including major adverse cardiovascular events, pulmonary complications, stroke, renal failure, sepsis, wounds, and gastrointestinal complications. Cox proportional hazards regression analysis was used to estimate the factors associated with postoperative complications during the 30-day follow-up period. Results Twenty-five patients (13.3%) had at least one major complication. The incidence of postoperative complications was identified more frequently in the high CONUT group (12 of 27, 44.4% vs. 13 of 161, 8.1%; p<0.001). Multivariate analyses showed that a high preoperative CONUT score was independently associated with 30-day postoperative complications (hazard ratio, 5.98; 95% confidence interval, 2.56ā€“13.97; p<0.001). Conclusion Our results showed that the CONUT score, a simple and readily available parameter using only objective laboratory values, is independently associated with early postoperative complications

    Complication Rate and Pitfalls of Temporary Bridging External Fixator in Periarticular Communited Fractures

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    BACKGROUND: A second staged operation using temporary bridging external fixation (TBEF) has been widely used in patients with periarticular complex fracture, yet few papers have been published on the related complications. The purpose of this study was to report the complication rate and pitfalls directly related to TBEF through a retrospective study and to suggest some solutions. METHODS: Fifty-nine cases that were treated by using TBEF were studied among 195 periarticular complex fractures. We retrospectively collected the clinical and radiological data and then the study data was evaluated for 1) cases with unsatisfactory restoration of length, 2) cases with deep infection caused by half pins invading the zone of definitive fixation, and 3) neurovascular injuries related to half pins. RESULTS: Complications were observed in 7/59 cases (11%). Problems related to the achievement of length were observed in one case of distal tibia fracture and 2 cases of distal femur fracture. Half pin related infection was observed in 2 cases of distal femur fracture. Neurovascular injury (medial calcaneal nerve injury in a distal tibia fracture) was observed in 2 cases. Among 7 complications, four were related to using TBEF in distal femur fracture. This is because the abundant leg muscles have strong deforming force and infection might be increased due to frequent irritation by the half pins. CONCLUSIONS: TBEF is a simple procedure with several advantages. However, complications might be observed if certain principles are not followed. It is thought that many complications due to TBEF can be reduced if the half pins are not inserted in the zone of injury, restoration of length is fully achieved and the neurovascular characteristics are carefully considered. In particular, much more caution is needed in the distal femur, which has abundant muscles surrounding it.ope

    Good Glycemic Control Is Associated with Better Survival in Diabetic Patients on Peritoneal Dialysis: A Prospective Observational Study

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    BACKGROUND: The effect of glycemic control after starting peritoneal dialysis (PD) on the survival of diabetic PD patients has largely been unexplored, especially in Asian population. METHODS: We conducted a prospective observational study, in which 140 incident PD patients with diabetes were recruited. Patients were divided into tertiles according to the means of quarterly HbA1C levels measured during the first year after starting PD. We examined the association between HbA1C and all-cause mortality using Cox proportional hazards models. RESULTS: The mean age was 58.7 years, 59.3% were male, and the mean follow-up duration was 3.5 years (range 0.4-9.5 years). The mean HbA1C levels were 6.3%, 7.1%, and 8.5% in the 1(st), 2(nd), and 3(rd) tertiles, respectively. Compared to the 1(st) tertile, the all-cause mortality rates were higher in the 2(nd) [hazard ratio (HR), 4.16; 95% confidence interval (CI), 0.91-18.94; pā€Š=ā€Š0.065] and significantly higher in the 3(rd) (HR, 13.16; 95% CI, 2.67-64.92; pā€Š=ā€Š0.002) tertiles (p for trendā€Š=ā€Š0.005), after adjusting for confounding factors. Cardiovascular mortality, however, did not differ significantly among the tertiles (p for trendā€Š=ā€Š0.682). In contrast, non-cardiovascular deaths, most of which were caused by infection, were more frequent in the 2(nd) (HR, 7.67; 95% CI, 0.68-86.37; pā€Š=ā€Š0.099) and the 3(rd) (HR, 51.24; 95% CI, 3.85-681.35; pā€Š=ā€Š0.003) tertiles than the 1(st) tertile (p for trendā€Š=ā€Š0.007). CONCLUSIONS: Poor glycemic control is associated with high mortality rates in diabetic PD patients, suggesting that better glycemic control may improve the outcomes of these patients

    Dual Roles of Quercetin in Platelets: Phosphoinositide-3-Kinase and MAP Kinases Inhibition, and cAMP-Dependent Vasodilator-Stimulated Phosphoprotein Stimulation

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    Background. Progressive diseases including cancer, metabolic, and cardiovascular disorders are marked by platelet activation and chronic inflammation. Studies suggest that dietary flavonoids such as quercetin possess antioxidant, anti-inflammatory, and antiplatelet properties, which could prevent various chronic diseases including atherosclerosis and thrombosis. However, the mechanism and the signaling pathway that links quercetin's antiplatelet activity with its anti-inflammatory property is limited and thus further exploration is required. The aim of this paper was to examine the link between antiplatelet and anti-inflammatory roles of quercetin in agonist-induced platelet activation. Methods. Quercetin effects on agonist-activated platelet-aggregation, granule-secretion, [Ca2+]i, and glycoprotein-IIb/IIIa activation were examined. Its effects on PI3K/Akt, VASP, and MAPK phosphorylations were also studied on collaged-activated platelets. Results. Quercetin dose dependently suppressed collagen, thrombin, or ADP-induced platelet aggregation. It significantly inhibited collagen-induced ATP release, P-selectin expression, [Ca2+]i mobilization, integrin-Ī±IIbĪ²3 activation, and augmented cAMP and VASP levels. Moreover, quercetin attenuated PI3K, Akt, ERK2, JNK1, and p38 MAPK activations, which were supported by platelet-aggregation inhibition with the respective kinase inhibitors. Conclusion. Quercetin-mediated antiplatelet activity involves PI3K/Akt inactivation, cAMP elevation, and VASP stimulation that, in turn, suppresses MAPK phosphorylations. This result suggests quercetin may have a potential to treat cardiovascular diseases involving aberrant platelet activation and inflammation
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