Chemical composition of precipitation in a forest area of Chongqing,Southwest China

Experiments were carried.out in Chongging-a city seriously damaged by acid precipitation in southwest China — to explore chemical compositions of open bulk precipitation, throughfall and stemflow in a Masson pine (Pinus massoniana) forest. The results showed that annual mean pH values of and annual ion depositions in the three types of rain water were 4.47 and 50.6 g m^?2, 3.82 and 69.7 g m^?2, and 2.92 and 0.215 g m^?2 respectively. pH values demonstrated an obvious seasonal variation; they were lower in winter than in the rest of the year. Ca²⁺ and NH _inf4 ^sup+ together made up more than 80% of the total cation, while SO _in4 ^sup2? alone contributed over 90% to the total anion. This high level of SO _in4 ^sup2? in rain water in Chongqing, which outran those found in other cities in China, was closely related to the combustion of locally produced coal that contains 3 to 5% sulphur. Thus, acid precipitation in Chongqing is of a typical sulphuric-acid type.     

Quality Control and Its Constraints during the Preparatory-Phase Activities of the Acid Deposition Monitoring Network in East Asia (EANET)

Participating countries of the Acid Deposition Monitoring Network in East Asia (EANET) launched the preparatory-phase activities from April 1998. For the recognition and improvement of the analytical precision and accuracy, the Interim Network Center (INC) carried out the inter-laboratory comparison on the analysis of artificial rainwater samples and soil samples. Relevant laboratories submitted their analytical data to the INC for the evaluation. Submitted data were summarized and evaluated in terms of precision and accuracy, and were compared with the Data Quality Objectives (DQOs) of EANET. These inter-laboratory comparisons made clear the present conditions of laboratories as well as the major constraints that should be solved in the future.     

Structure-activity relationships of flavonoids as potential inhibitors of glycogen phosphorylase

Flavonoids are ubiquitous components in vegetables, fruits, tea, and wine. Therefore, they are often consumed in large quantities in our daily diet. Several flavonoids have been shown to have potential as antidiabetic agents. In the present study, we focused on inhibition of glycogen phosphorylase (GP) by flavonoids. 6-Hydroxyluteolin, hypolaetin, and quercetagetin were identified as good inhibitors of dephosphorylated GP (GPb), with IC 50 values of 11.6, 15.7, and 9.7 microM, respectively. Furthermore, a structure-activity relationship study revealed that the presence of the 3' and 4' OH groups in the B-ring and double bonds between C2 and C3 in flavones and flavonols are important factors for enzyme recognition and binding. Quercetagetin inhibited GPb in a noncompetitive manner, with a K i value of 3.5 microM. Multiple inhibition studies by Dixon plots suggested that quercetagetin binds to the allosteric site. In primary cultured rat hepatocytes, quercetagetin and quercetin suppressed glucagon-stimulated glycogenolysis, with IC 50 values of 66.2 and 68.7 microM, respectively. These results suggested that as a group of novel GP inhibitors, flavonoids have potential to contribute to the protection or improvement of control of diabetes type II.     

Seasonal Variations of Nitrogen Isotopic Ratios of Ammonium and Nitrate in Precipitations Collected in the Yahiko–Kakuda Mountains Area in Niigata Prefecture,Japan

Water, Air, & Soil Pollution - Precipitation was collected from May 15, 2001 to November 18, 2002, at the mountain top (620 m a.s.l.) and mountain foot (47 m a.s.l.) of the...     

Races of <Emphasis Type="Italic">Phytophthora infestans</Emphasis> isolated from potato in Hokkaido,Japan

The virulence of 29 isolates of Phytophthora infestans collected in potato fields in Hokkaido, Japan, in 2013 and 2014, was tested for race identification. Thirteen different races were identified, each of which had five to eight virulence factors. All of the isolates caused a virulent reaction against plants with R1 and R7, and most of the isolates caused a virulent reaction against plants with R3, R4, R10, and R11. On the other hand, no isolate was virulent against plants with R9. These results demonstrate that the current Japanese P. infestans population is more complex than the population in the 1990s from the viewpoint of race.     

Comparison of scytalone dehydratase activities between scytalone dehydratase inhibitor-sensitive and inhibitor-resistant Magnaporthe oryzae isolates

Journal of Plant Diseases and Protection - Magnaporthe oryzae is the causal agent of blast disease of cereals such as rice. Recently, fungal isolates resistant to the melanin biosynthesis...     

Acute Phase Pulmonary Responses to a Single Intratracheal Spray Instillation of Magnetite (Fe3O4) Nanoparticles in Fischer 344 Rats

Iron nanomaterials are of considerable interest for application to nanotechnology-related fields including environmental catalysis, biomedical imaging, drug delivery and hyperthermia, because of their superparamagnetic characteristics and high catalytic abilities. However, information about potential risks of iron nanomaterials is limited. The present study assessed pulmonary responses to a single intratracheal spray instillation of triiron tetraoxide nanoparticles (magnetite) in rats. Ten-week-old male and female Fischer 344 rats (n=5/group) were exposed to a single intratracheal spray instillation of 0 (vehicle), 5.0, 15.0 or 45.0 mg/kg body weight (BW) of magnetite. After 14 days, the rats were sacrificed, and biological consequences were investigated. The lung weights of the 15.0 and 45.0 mg/kg BW male and female groups were significantly higher than those of the control groups. The lungs of treated rats showed enlargement and black patches originating from the color of magnetite. The typical histopathological changes in the lungs of the treated rats included infiltration of macrophages phagocytosing magnetite, inflammatory cell infiltration, granuloma formation and an increase of goblet cells in the bronchial epithelium. The results clearly show that instilled magnetite causes foreign body inflammatory and granulating lesions in the lung. These pulmonary responses occur in a dose-dependent manner in association with the increase in lung weight.