536 research outputs found

    Highly Sensitive Singlet Oxygen Spectroscopic System Using InGaAs PIN Photodiode

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    The spectrum of 1O2 was measured by the InGaAs photodiode for an optical communication system with charge integration amplifier (InGaAs-CIA). The photo-excited current is charged in photodiode junction capacitance itself. The current is changed to the voltage about 1012 times without feedback resistance. The minimum detectable power of InGaAs CIA system with liquid nitrogen was achieved 0.1 fW of 10 sec integration time at the wavelength of 1.28 μm. The optical band pass filter-based system for ultra–low-level light detection was succeeded in spectrum measurement of 1O2 by 13-LOOH with cytochrome c. The 8 channel InGaAs-CIA array system enables to achieve optical multichannel detection for ultra-low level light at 10−13 W from 10−15 W level in the near-infrared region. The optical resolution was about 200 nm by 1 channel. The spectrum of 1O2 by mixing NaOCl and H2O2 was demonstrated. The shape of spectrum by 1O2 was matched to that of measured by the spectrometer. The system was succeeded in instantaneous 1O2 spectrum measurement without moving the wavelength dispersion device. The generation of 1O2 by photo-excited Rose Bengal was fabricated to develop food antioxidant chemistry or source reagent of cosmetic product. The system uses super luminosity LED for excitation light source and InGaAs CIA. The 1O2 generation will be controlled by the InGaAs-CIA monitoring system. The system will be used in the chemical plant of primary material production

    Allergic inflammation, its development mechanism and per­meability of cell membrane

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    The ascitic monocytes and subcutaneous cells and tissues of sensitized animals have been observed after exposing to antigen for the purpose of revealing the disintegration processes of the cells related with inflammation and it has been proved that the permeability of the cell membrane increases markedly resulting in the swelling of the cells at the moment when the cells come in contact with antigen. The localization of the antigen in the Arthus' phenomenon will be the results of the gelatination of the inter-cellular tissues and the swelling of cells. And it is indicated that the cell death accompanied by an allergic inflammation is caused by the increased permeability of the cell membrane which will result in the activation of the intra-cellular enzymes followed by the acute disintegration of the molecular structure of the cell and release of the so-called inflammatory substances.</p

    Non-Breaking Undular Hydraulic Jump

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    The discusser performed a large number of experiments on undular hydraulic jumps (CHANSON 1993, 1995a). Most results were reported in CHANSON and MONTES (1995) and CHANSON (1995b, 1995c). The discusser wishes to stress several aspects of undular jump flows and he will show that the work of REINAUER and HAGER did not bring really new information

    Differential regulation of proopiomelanocortin (POMC) mRNA expression in hypothalamus and anterior pituitary following repeated cyanamide with ethanol administration

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    Background/Aim. We have investigated proopiomelanocortin (POMC) mRNA expression in the arcuate nucleus of the hypothalamus (ARC) and the anterior lobe of the pituitary (AL) following repeated cyanamide-ethanol reaction (CER). Methods. Adult male Sprague -Dawley rats (250 −290 gr) were housed in a temperature and humidity controlled environment with free access to food and water. Four experimental groups were used as follows: saline (as control), cyanamide alone, ethanol alone and ethanol with cyanamide. The animals received daily intraperitoneal injections (i.p.) of cyanamide (10mg/kg, 60 min before ethanol dosing) with or without ethanol (1g/kg) for 5 consecutive days, and were sacrificed 60 min after the last dosing of ethanol. The results were presented as the mean ± SEM for each group. All groups within each data set were compared by one-way ANOVA followed by Fisher PLSD test for multiple comparisons. A value of p&lt;0.05 was considered significant. Results. The POMC mRNA levels in ARC were significantly decreased with cyanamide compared to the control and ethanol alone (p&lt;0.05 and p&lt;0.05 respectively), but increased in AL following repeated CER. Conclusion. We speculate that this differential regulation of POMC mRNA expression may be partially involved in the preventive effects on alcohol intake in response to CER

    Hydraulic Condition for Undular Jump Formations. (Discussion)

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    An undular hydraulic jump is characterised a series of steady, stationary free-surface undulations developing downstream of the jump toe. During their classical experiments in the Canal de Bourgogne, Pont-aqueduc de Roquefavour and Pont-aqueduc de Crau, DARCY and BAZIN (1865) observed undular jumps with marked undulations extending over lengths of up to 150 m. While there might be recreational applications, design engineers tend to avoid undular hydraulic jump formation in natural channels because of higher required embankment heights to prevent overtopping and because of the risks of bed scour and large bed form formation (CHANSON 1995, 2000). The propagation of freesurface undulations and waves may impose additional impact loads, perturbations and vibrations on downstream canal structures : e.g., gates, locks, weirs. In one case, the occurrence of an undular jump immediately upstream of the intake perturbed the pump operation. Similarly undular tidal bores are well-known navigation disturbances. It is therefore essential to predict accurately the limiting conditions for free-surface undulations, and the writers' contribution is important

    Effects of Insecticides on Spiracle Movements in Insect

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    We studied the effects of permethrin and DDVP on thoracic spiracle movements of the male cockroach. Permethrin increased, rather than decreased, the average open time of thoracic valve 1 in low or lethal doses, with no large change in the frequency of the opening and closing. In thoracic spiracle 2, the average open time was reduced by 1/3 of the control, but the opening frequency was markedly increased. DDVP had a similar effect on thoracic spiracle 1. The action of DDVP was only transiently and partially antagonized by atropine. These results suggest that the thoracic spiracle 1 valve tends to open, probably by a peripheral control mechanism, rather than to close, during permethrin or DDVP poisoning in insects

    Less contribution of the nicotinic cholinergic and α2-adrenergic action of high acetaldehyde concentration on the inhibition of intestinal ethanol absorption

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    In the present study, we investigated the effects of hexamethonium, a ganglionic nicotinic receptor blocking agents and yohimbine, an α2-adrenergic antagonist, on reduction of ethanol absorption in presence of high acetaldehyde concentration. Hexamethonium had no effect, whereas yohimbine by itself reduced ethanol absorption, but no additional effects were observed with presence of high acetaldehyde. Propionaldehyde had an inhibitory action on intestinal 1-propanol absorption. As both yohimbine and propionaldehyde are associated with vagus nerve activation, these results indirectly support the hypothesis that a cholinergic mechanism through vagus nerve activation is responsible for the inhibition of intestinal ethanol absorption by acetaldehyde

    Surgery for Irradiation Damage to the Digestive Tract.

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    The surgical outcome of radiation injury to the gut was evaluated on the basis of clinical experience. The main affected gut was the rectum in frequency. In most cases, colostomy was selected and the affected gut was left as it was. Some suffered from bleeding episode and 4 had carcinoma arising from radiation injury. In conclusion, early resection of affected guts associated with clinical symptoms is recommended as the treatment of radiation-injured gut

    A liquid crystalline phase in spermidine-condensed DNA

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    Over a large range of salt and spermidine concentrations, short DNA fragments precipitated by spermidine (a polyamine) sediment in a pellet from a dilute isotropic supernatant. We report here that the DNA-condensed phase consists of a cholesteric liquid crystal in equilibrium with a more concentrated phase. These results are discussed according to Flory's theory for the ordering of rigid polymers. The liquid crystal described here corresponds to an ordering in the presence of attractive interactions, in contrast with classical liquid crystalline DNA. Polyamines are often used in vitro to study the functional properties of DNA. We suggest that the existence of a liquid crystalline state in spermidine-condensed DNA is relevant to these studies

    Contribution of renal angiotensin II type I receptor to gene expressions in hypertension-induced renal injury

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    Contribution of renal angiotensin II type I receptor to gene expressions in hypertension-induced renal injury. Recent evidence indicates that transforming growth factor-β1 (TGF-β1) plays an important role in renal fibrosis via stimulation of extracellular matrix synthesis. The present study was undertaken to investigate the role of angiotensin II type I receptor (AT1 receptor) in hypertension-induced renal injury. Twenty-two-week-old stroke-prone spontaneously hypertensive rats (SHRSP), which had established hypertension and moderate renal damage, were orally given TCV-116, a selective non-peptide AT1 receptor antagonist (0.1, 1 or 10 mg/kg/day), enalapril (10 mg/kg/day) or vehicle once a day for 10 weeks. At the end point of the treatment, we examined renal function, the gene expressions of TGF-β1 and extracellular matrix components in the interstitium [collagen types I (COI) and III (COIII), fibronectin (FN)] and the basement membrane (COIV and laminin), and renal microscopic morphology in rats aged 32 weeks. In vehicle-treated 32 week-old SHRSP with renal dysfunction and nephrosclerosis, renal mRNA levels for TGF-β1, COI, COIII, FN, COIV were all several-fold higher than in WKY. Thus, renal TGF-β1 gene expression was enhanced in SHRSP, which may contribute to the increased renal expressions of COI, COIII, FN, COIV in SHRSP. Treatment with TCV-116 (0.1 mg/kg/day) in SHRSP, in spite of no reduction of blood pressure, decreased renal mRNA levels for TGF-β1, COI, COIII, FN, COIV, being accompanied by the significant decrease in urinary protein and albumin excretion, blood urea nitrogen and plasma creatinine. Treatment with TCV-116 (10 mg/kg/day) in SHRSP decreased mRNAs for TGF-β1, COI, COIII, FN and COIV to almost the same levels as WKY, being associated with normalization of urinary protein and albumin excretion and the prevention of nephrosclerosis, as judged by microscopic histological observations. On the other hand, the effects of enalapril (10 mg/kg/day) on the above mentioned mRNA levels, renal function and renal morphology were weaker than those of TCV-116 (10 mg/kg/day) and were as much as TCV-116 (1 mg/kg/day). These results suggest that independently of hypotensive action, AT1 receptor antagonist has a potent renal protective effect by inhibiting the gene expression of renal TGF-β1 and extracellular matrix components
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