Estimation of transport distance of fine particulate organic matter in relation to channel morphology in tailwaters of the Lake Biwa and reservoir dams

Knowledge on transport and deposition of fine particulate organic matter (FPOM) from reservoir dams is increasingly required for habitat management and restoration of dam tailwater ecosystems. Variations in the transport distance of FPOM, however, have never been studied well, particularly in relation to channel morphology, due to channel size restrictions of artificial tracers such as corn pollen when applied to larger river channels. This study aims to show the relations between FPOM retention efficiency and channel morphology in dam tailwaters using lentic plankters as tracers. We estimated the mean transport distance, S _p, by calculating downstream reduction ratios of lentic tracer plankters and calculated the deposition velocity, v _dep. Suspended FPOM samples were collected in tailwaters of two river channels below reservoir dams and two artificial canals below Lake Biwa in the Yodo River system. The longest S _p (19.2 km) and the shortest one (2.2 km) were recorded in the deep canal and shallow canal, respectively, showing a positive correlation with channel hydraulic radius. The values of v _dep were 4.7–6.4 times higher in river channels than in artificial canals. These results indicate that increasing complexity of bed morphology can minimize S _p, whereas bed degradation and armored bed materials may lead to increased S _p. Advantages of lentic plankters as tracers for estimating distance ranges of reservoir dam impact on river ecosystems are also discussed.     

Evaluating the novel parameters for assessing the LAA function and thrombus formation with nonvalvular atrial fibrillation

The dysfunction of left atrial appendage (LAA) is prone to form thrombus when atrial fibrillation (AF) sustained more than 48 h. Traditional 2D-TEE (transesophageal echocardiography) can not accurate evaluate the function of LAA. The purpose of this study is to analyze the relationship of LAA function parameters and thrombus formation in patients with non-valvular atrial fibrillation (NVAF) by real-time three-dimensional transesophageal echocardiography (RT-3D-TEE). High risk patients can be identified according to the characteristics of ultrasonic index in patients with left atrial appendage thrombosis, which has important clinical value and significance in the risk assessment, guiding treatment and judging prognosis. We examined the relationship between the echocardiographic parameters of LAA function and the incidence of thrombus in 102 NVAF patients. They underwent RT-3D-TEE and left atrial appendage thrombus (LAAT)/severe spontaneous echocardiographic contrast (SSEC) was found in 67 patients (thrombus group) but absent in the remaining 35 patients (non-thrombus group). After measured by QLAB software, the LAA functional parameters were significantly associated with LAAT/SEC formation. Univariate analysis indicated that AF time, LAD, LVEF, LAA-OAmax, LAAVmax, LAAVI and LAAEF demonstrated a positive association (P < 0.05). However, logistic regression analysis identified that AF time (OR:1.73, P < 0.05)、LAAEF (OR:4.09, P < 0.01)and LAAVI (OR:3.28, P < 0.01) were independent predictors of LAAT/SSEC. In patients with nonvalvular atrial fibrillation, echocardiographic parameters of LAA function are significantly associated with LAAT/SSEC.     

Development of a risk scoring system for patients with papillary thyroid cancer

As the importance of personalized therapeutics in aggressive papillary thyroid cancer (PTC) increases, accurate risk stratification is required. To develop a novel prognostic scoring system for patients with PTC (n = 455), we used mRNA expression and clinical data from The Cancer Genome Atlas. We performed variable selection using Network‐Regularized high‐dimensional Cox‐regression with gene network from pathway databases. The risk score was calculated using a linear combination of regression coefficients and mRNA expressions. The risk score and clinical variables were assessed by several survival analyses. The risk score showed high discriminatory power for the prediction of event‐free survival as well as the presence of metastasis. In multivariate analysis, the risk score and presence of metastasis were significant risk factors among the clinical variables that were examined together. In the current study, we developed a risk scoring system that will help to identify suitable therapeutic options for PTC.     

Comparison of estrogen and genistein in their antigenotoxic effects, apoptosis and signal transduction protein expression patterns

The antigenotoxic effects of estrogen and genistein (isoflavones) were compared by measuring the degree of protection against plasmid DNA strand breakage induced by peroxyl free radicals using the DNA strand scission assay with pBR322 DNA. Isoflavones decreased DNA strand breakage by AAPH radical treatment at the all of three concentrations tested (0.5, 1.0, 1.5 microg/ml) with the range of 89.5% to 99.6%. Compared to genistein, estrogen was not as effective as genistein showing 46.9% to 29.6% protection, and this protective effect was decreased as estrogen concentrations increased from 0.1 to 0.3 microg/ml. DNA ladder experiments showed that genistein induced apoptosis in cultured cell lines, whereas estrogen did not induce any apoptosis. The effects of cell signal trandsduction protein expression patterns were compared between estrogen and genistein. The increased expression of cyclin B1 by estrogen was tampered by genistein at the highest concentration. Antigenotoxic and antiproliferative effects of genistein shown in this study support the hypothesis that it has a chemopreventive effect against particular types of cancers.