Extraction of bioavailable phosphorus in soils and sediments using an ultrasonic washing machine.

For improving the management of watershed eutrophication, methods for measuring bioavailable phosphorus (BAP) are more important than measurements of total phosphorus (TP). BAP in particulate form (P-BAP) is an important substance that promotes eutrophication, especially during rainy seasons. Only a portion of particulate phosphorus (PP) is taken up by algae that contribute to eutrophication.

Ultra-sensitive HPLC-photochemical reaction-luminol chemiluminescence method for the measurement of secondary amines after nitrosation.

A novel method for the determination of secondary amines at the nanomolar level was developed. The method is based on the nitrosation reaction of secondary amines, with the generated N-nitrosamines being measured using an HPLC separation, photochemical reaction, and chemiluminescence detection system. The efficient nitrosation of secondary amines was performed using sodium nitrite (200 mM) and acetic acid (0.

Rapid method for monitoring N-nitrosodimethylamine in drinking water at the ng/L level without pre-concentration using high-performance liquid chromatography-chemiluminescence detection.

As a contaminant in drinking water, N-nitrosodimethylamine (NDMA) is of great concern because of its carcinogenicity; it has been limited to levels of ng/L by regulatory bodies worldwide. Consequently, a rapid and sensitive method for monitoring NDMA in drinking water is urgently required. In this study, we report an improvement of our previously proposed HPLC-based system for NDMA determination.

Fluorescent character of Cu(I/II) complexes with bisquinoline-based ligands and fluorometric detection of reductants.

The fluorescence ligands N,N'-bis(2-methylquinolyl)dimethylethylenediamine (BQDMEN) and N,N'-bis(2-methylquinolyl)dimethyl-1,3-propanediamine (BQDMPN) were synthesized. [Cu(II)(bqdmen)](2+) and [Cu(II)(bqdmpn)](2+) were prepared, and their reduction to [Cu(I)(bqdmen)](+) and [Cu(I)(bqdmpn)](+) was confirmed by the observed UV-Vis spectral change. Then, the fluorescence of [Cu(I/II)(bqdmen)](+/2+) and [Cu(I/II)(bqdmpn)](+/2+) in aqueous solution was characterized; [Cu(I)(bqdmen)](+) and [Cu(I)(bqdmpn)](+) were found to fluoresce in aqueous solution, whereas the fluorescence of [Cu(II)(bqdmen)](2+) and [Cu(II)(bqdmpn)](2+) was completely quenched.

Aldosterone inhibits endothelial morphogenesis and angiogenesis through the downregulation of vascular endothelial growth factor receptor-2 expression subsequent to peroxisome proliferator-activated receptor gamma.

Angiogenesis plays a pivotal role in cardiovascular diseases such as ischemic heart disease, limb ischemia and heart failure, and has recently been shown to mediate various biological activities related to the pathogenesis of these diseases. In the present study, we evaluated the role of aldosterone in angiogenesis. Tube formation assay on Matrigel using human umbilical vein endothelial cells (HUVEC) revealed that aldosterone inhibited endothelial morphogenesis in a manner sensitive to eplerenone, a selective mineralocorticoid receptor antagonist.