Confirmation of anatoxin-a(s), in the cyanobacterium Anabaena lemmermannii, as the cause of bird kills in Danish lakes

Cyanobacterial blooms were implicated in bird kills at lakes in Denmark in July 1993 and June-July 1994. These blooms were dominated by Anabaena lemmermannii and were shown to contain a neurotoxin with anticholinesterase activity. In this study, the toxin was isolated by mouse lethality guided column chromatographies from the field sample collected at Lake Knud s? in 1993. Various spectroscopic data indicated that the toxin was anatoxin-a(s), an irreversible anticholinesterase, first reported in Anabaena flos-aquae. Chemical detection of the same toxin in cultured A. lemmermannii also confirmed this species as the cause of the deaths of the wild birds.     

Rapid and comprehensive indicator for evaluation of performance of treatment processes and of river waters.

Naturally occurring UV active compounds, commonly present in almost all source waters, can be rapidly monitored by their ultraviolet absorbance at 260 nm (E260). Herein, the extent of correlation between the E260 and the removal efficiency of the hazardous contaminants, endocrine disrupters and dioxins, were investigated using various treatment and river source waters. The detection of various types of hazardous contaminants using sophisticated analytical methods, such as high resolution gas chromatography (HRGC)/high resolution mass spectrometry (HRMS) and high performance liquid chromatography (HPLC)/inductively coupled plasma (ICP)/mass spectrometry (MS), as well as various short-term bioassays, can require hours or even days for results to be obtained. The removal of the E260 correlated well with those of individual contaminants, such as endocrine disruptor chemicals and dioxins, with the various treatment processes employed. In the plots of the endocrine disrupters against the DOC/E260, a correlation was found with the endocrine activity of the Korean/Japanese river waters employed in this study.     

EFFICIENCY OF PETROLEUM CONCENTRATION IN MAJOR PETROLIFEROUS BASINS

The ratio of the concentration (barrels of oil equivalent/sq. km) of accumulated oil in the richest sedimentary basin to that in the poorest basin, among those basins containing "giant" and "super-giant" fields, is more than 500 to 1. By contrast, the ratio of the richest to the poorest petroliferous basin in terms of average organic concentration may be less than 20 to 1. Such a large discrepancy between these two ratios suggests that organic concentration alone cannot account, for petroleum concentration in commercial reservoirs, because significant quantities of petroleum may be lost to the surface and be disseminated throughout the sedimentary sequence if the trapping conditions are not suitable. Most of this disseminated petroleum cannot be produced economically using present-day technology.
For a more accurate petroleum assessment, the Author stresses the importance of the efficiency of petroleum accumulation and preservation in commercial reservoirs: this may be evaluated as combining (a) the organic concentration of the source rock, (b) the duration of oil generation, (c) the thickness of the oil-generating "window", (d) the total geologic age involved, and (e) the fluid expulsion rate, and the presence or absence of undercompacted intervals.
Other parameters, such as the trap, reservoir and cap rock, and also the types of organic matter in the source rock, may have a great influence on the efficiency of petroleum concentrations in commercial reservoirs. However, most of these factors are of local significance, and thus are more difficult to generalise than those mentioned above in the context of the global distribution and concentration of oil reserves.     

p53 alteration, proliferating cell nuclear antigen, and nucleolar organizer regions in thymic epithelial tumors

We examined p53 protein expression, p53 gene mutation, proliferating cell nuclear antigen (PCNA), and argyrophilic nuclear organizer regions (AgNOR), in 30 patients with surgically-treated thymic tumors (26 thymoma and 4 thymic carcinoma cases). p53 expression ratio with DO-1 was divided as p53 negative (0% positivity), low expressor (<10% positivity), high expressor (>10% positivity). The incidence of p53 low and high expressor in thymoma were 19% (5/26) and 8% (2/26), respectively. p53 immunopositivity in thymoma was significantly correlated with PCNA labeling index (LI). p53 expression ratio in invasive thymoma (33%) tended to be higher than that in non-invasive thymoma (18%). p53 expression was detected in one of the thymic carcinoma. There were no p53 gene mutations in 15 invasive thymoma, although one of four (25%) thymic carcinomas showed two point mutations. p53 gene alterations seem to be associated with malignant activity of tumor cells, and therefore detection of p53 gene mutations is useful as a diagnostic factor.     

Repeatedly foldable AMOLED display

In this study, a 5.9‐inch foldable active‐matrix organic light emitting diode (AMOLED) display was developed. A folding test was performed repeatedly. The display survived the folding test (100,000 folds) with a curvature radius of 2 mm. To protect an organic light emitting diode (OLED) against moisture, inorganic passivation layers are provided on the upper and lower sides of the flexible display. Using our transfer technology, high density passivation layers can be obtained. The measured water vapor transmission rate of the layer is 7 × 10^?6 g/m²?day or less, which improves OLED reliability. With these techniques, we have developed a book‐type display, which is repeatedly foldable like a book, and a tri‐fold display including a display area, which is foldable in three.     

Effect of heparin on high glucose induced proliferation and expression of matrix metalloproteinases in normal human mesangial cells

Background The pathogenesis of diabetic nephropathy (DN) is a complex pathophysiological process. Its precise mechanism is not fully known. In recent years it has been recognized that synthesis of various extracelluar matrix (ECM) components may increase, and that degradation of ECM may decrease in DN. It was reported heparin could inhibit mesangial cells proliferation in vitro. The main aim of this study is to explore whether heparin inhibits proliferation of mesangial cells grown in high glucose concentration and to measure the effect of heparin on matrix metalloproteinases (MMPs) expression in mesangial cells. Methods The medium contained either low glucose (5 mmol/L) or high glucose (25 mmol/L). The concentrations of heparin in the culture medium were 0, 25, 50, 100, 200 or 400 μg/mL. A metabolic (WST-1) assay was used to measure mesangial cell proliferation and Western blot analysis was used to measure MMPs expression of mesangial cells. Results Normal human mesangial cell (NHMC) proliferation was higher in high glucose (HG) medium than in low glucose (LG) medium. They showed a 1.93 fold expansion after 72 h in high glucose in contrast to a 1.63 fold expansion in low glucose. In the presence of heparin, mesangial cells proliferation was inhibited, which was more obvious at high glucose concentrations than at low glucose concentrations. In high glucose, with heparin concentration of 50, 100, 200 and 400 μg/mL, the mesangial cells showed a 0.61 fold, 0.52 fold, 0.52 fold and 0.41 fold reductions in cell number compared to cells grown without heparin. In low glucose, only concentrations of 200 μg/mL and 400 μg/mL showed reduction in cell number, namely 0.54 fold and 0.45 fold, when compared to cells grown without heparin. In Western blot analysis, MMP₁, MMP₂, MMP₃ and MMP₉ was expressed by mesangial cells expressed in both high and low glucose concentrations, which was more prominent in high glucose medium. Incubation of heparin further increased expression of MMP₁, MMP₂, MMP₃ and MMP₉. Conclusions This study suggests that glucose can accelerate mesangial cell proliferation while heparin can reduce proliferation, being more obvious at high glucose concentrations. Higher glucose concentrations led to increased MMP expression, which may take part in the regulation of mesangial matrix synthesis and degradation. Addition of heparin resulted in a corresponding increase in MMP expression, most notably at high glucose concentrations, indicating a potentially renoprotective role in DN. Foundation item: Project (30370663) supported by the National Natural Science Foundation of China     

Fabrication of (Pb,La)(Zr,Ti)O/sub 3/ thin-film arrayed waveguide grating

The design and fabrication of an 8-ch, 500 GHz-spacing arrayed waveguide grating on (Pb,La)(Zr,Ti)O₃ has been successfully achieved for the first time. An insertion loss of 22.1 dB, including a 10 dB coupling loss, and an adjacent crosstalk of -23.1 dB have been obtained. The device is expected to be monolithically integrated into high-speed optical switches to form integrated chips such as a reconfigurable add-drop multiplexer     

Absolute Configuration of β- and α-Asymmetric Carbons within β-O-4-Structures in Hardwood Lignin

In this study, we investigated the proportion of erythro- and threo-forms of β-O-4-ether structures and their enantiomeric compositions in hardwood lignin by applying the ozonation method to birch wood meal. Optical activity was not substantially observed in either the erythronic or threonic acids obtained as the ozonation products of β-O-4-structures in birch wood meal. The proportions of the four stereoisomeric forms {(αS,βR)-erythro, (αR,βR)-threo, (αS,βS)-threo, and (αR,βS)-erythro forms} were estimated to be 37-38%, 13-14%, 12-13%, and 36-37% based on the yields of erythronic and threonic acids, and on their optical activities. The proportions suggest that the entire components of β-O-4-ether structures in birch wood lignin have R- and S-configurations at the β-carbon in approximately the same quantities {(βR)-β-O-4-structure: (βS)-β-O-4-structure = 50–52:48–50}; i.e., that the β-ether structures are essentially racemic. This estimation implies that, during lignin biosynthesis, an equal number of enantiomeric forms of β-O-4-bonded quinone methides were formed by radical coupling reactions.     

The use of a virtual city model for assessing equity in access to views

The development of virtual city models has provided novel possibilities for analyses that require consideration of building heights in urban areas. The study was undertaken to explore these possibilities by using the virtual Kyoto model to examine equity in access to views in the Japanese city. A sample of just over 5000 residences was selected by stratifying for population age and affluence. A series of viewsheds were computed to quantify the visibility of a range of environmental amenities (greenspaces, water bodies, historical buildings, mountains) and disamenities (factories and roads). Evidence of inequity in visual amenity was identified, whereby homes in areas with many old people were much less likely to have views of greenspaces and water bodies, although they were also less likely to see factories and roads and were more likely to view mountains. Homes in more affluent areas had better views of greenspaces, historical buildings, and mountains, and were less likely to see factories and water bodies. We discuss the potential of virtual city models for furthering analyses of the urban environment and raise some caveats regarding their use.     

Synthesis and antiallergic activity of dimethyl-2-(phenylcarbamoyl)ethylsulfonium p-toluenesulfonate derivatives

The derivatives of dimethyl-2-(phenylcarbamoyl)ethylsulfonium p-toluenesulfonates were synthesized and evaluated for antiallergic activity. The 2,3-dihydroxyethoxy group was introduced to the phenyl ring from the standpoint of lipophilicity and electronic effects of substituent. The IgE-induced rat passive cutaneous anaphylaxis (PCA) was inhibited by oral administration of several substituted 2-[(4-propoxyphenyl)carbamoyl]ethyldimethylsulfonium p-toluenesulfonate derivatives. Among them (+/-)-2-[N-[4-(3-ethoxy-2-hydroxypropoxy)phenyl]carbamoyl]ethyldimeth ylsulfonium p-toluenesulfonate (1a, IPD-1151T) was found to possess considerable activity in the PCA test, and it was launched as Suplatast tosilate in Japan.