Cation exchange of surface protons on silica gel with cupric ions

The exchange of surface protons on silica gel with cupric ions was investigated under two different conditions. The equilibrium constant was determined and the mechanism of the exchange was suggested. In ammonia water, two protons exchange with one tetrammine cupric ion and formed two ammonium ions. In acidic solution, where one proton exchanges with one cupric ion, the apparent equilibrium constant increases with an increase in the amount of copper loading. The structure of surface species on silica gel was suggested from the mechanism of the exchange and from ESR study. The surface species prepared in acidic solution is changed into the one prepared in ammonia water by exposure to ammonia. The change in the structure of surface species by the adsorption of foreign molecules was also studied.     

Acute effect of ethanol on 7-hydroperoxycholesterol in muscle and liver

We tested the hypotheses that ethanol sensitivities of muscle and liver can be discerned in the initial periods of ethanol exposure, especially when acetaldehyde levels are markedly raised with cyanamide, an aldehyde dehydrogenase inhibitor. To test this, we measured cholesterol hydroperoxides in soleus (Type I) and plantaris (Type II) muscle in four groups of rats acutely (i.e., 2.5 h) exposed to: [S] saline (control), [Cy] cyanamide, [EtOH] ethanol, or [Cy+EtOH] cyanamide+ ethanol. Comparative reference was also made to the response of the liver. After 2.5 h, ethanol alone significantly increased 7α-hydroperoxycholest-5-en-3β-ol (7α-OOH) and 7β-hydroperoxycholest-5-en-3β-ol (7β-OOH) levels in plantaris muscle. Identical qualitative effects were seen in rats treated with cyanamide+ethanol, but there was no discernible difference between groups [LtOH] and [Cy+EtOH]. In both the soleus muscle and liver, none of the treatments with either ethanol or cyanamide+ethanol had any effect on any of the measured parameters. This is the first report of a differential response of 7α-OOH and 7β-OOH in Type II, compared to Type I predominant muscles, and the first time that muscle has been shown to be more sensitive than the liver in terms of its lipid marker response to oxidative stress. Perturbations in the muscle membrane lipid domain may contribute to impaiment of muscle in alcoholism.     

Environmentally acceptable nuclear fuel cycle development of a new reprocessing system

The aim of the present study is to establish a new reprocessing system for spent nuclear fuel, which would overcome the environmental problems in the nuclear fuel cycle. In order to achieve this, the following subjects have to be conquered: recoveries of high ratios of uranium and trans uranium elements from spent nuclear fuel, separations of strong radioactive elements, such as Sr and Cs, and assurance of the extreme safety during operation. The last subjects might be of particular importance in order to avoid any potential danger. Therefore, in the present system all processes were performed under mild aqueous conditions. Experiments were carried out for a simulated spent fuel solution, which was calculated from the ORIGEN CODE containing uranium and 17 major elements. The system consists of the following processes: 1. dissolution of spent UO₂ fuel involving off-gas treatment of I and Ru; 2. neutralization of the dissolved fuel solution with NaHCO₃---Na₂CO₃ mixed solution to be slightly basic at pH about 9 followed by the separation of precipitated fission products by centrifugation; 3. separation of Cs by a precipitation method using tetraphenylborate ion; 4. recovery of U, Np and Pu as precipitates of hydrolyzed compounds from alkaline solution; 5. separation of Am and Cm from lanthanide elements. The concentration of residual uranium in the final solution was measured to be ppm order, indicating that the decontamination factor of U was as large as 10⁴. Other hexa-valent actinide ions, NpO₂²⁺ and PuO₂²⁺, also have extremely large stability constants for the complex formation with carbonate ion, and are expected to behave similarly with UO₂²⁺. In conclusion, the present reprocessing system enables us to recover U, Pu and Np from spent nuclear fuel by means of a simple precipitation method in much higher ratios compared with other reprocessing methods, to separate hazardous Cs and Sr from high-level waste, and to exclude any potential danger owing to chemical processes under mild aqueous conditions.     

Detection of recombinant DNA from genetically modified papaya

A method using polymerase chain reaction (PCR) was developed to detect the genetically modified (GM) papaya (55-1 line), of which the mandatory safety assessment has not been finished in Japan because of insufficient data. The papaya intrinsic papain gene was used as an internal control. The results of PCR amplification of the papain gene segment indicated that a commercial silica membrane type kit (QIAGEN DNeasy plant mini) was useful for extraction of DNA from papaya fruit, but not for extraction from canned papaya fruit. On the other hand, a commercial ion-exchange type kit (QIAGEN Genomic-tip) provided enough purified DNA for PCR from canned papaya fruit. Compared with the parental line and other commercial non-GM papayas, the DNA from GM papaya fruit provided specific amplification bands in PCR with five primer pairs (Nos. 2-6) including beta-glucuronidase and neomycin phosphotransferase II gene-specific ones. On the other hand, the primer pairs recognizing these genes showed false-positive results when we used DNAs from canned papaya. Therefore, we recommend that the primer pairs (Nos. 5 and 6) recognizing the sequences derived from two different species of organism should be used in order to detect specifically the GM papaya in canned fruits.     

Auraptene regulates gene expression involved in lipid metabolism through PPARα activation in diabetic obese mice

Scope: Peroxisome proliferator‐activated receptor‐α (PPARα) is a key regulator of circulating lipid level. Thus, various food‐derived compounds that activate PPARα as agonists have been screened and characterized. Methods and results: We investigated the effects of auraptene, a citrus‐derived compound serving as a PPARα agonist in vitro, on abnormalities in lipid and glucose metabolisms. In high‐fat‐diet (HFD)‐fed KK‐Ay diabetic obese mice, auraptene treatment suppressed hyperlipidemia and triglyceride accumulation in the liver and skeletal muscle, and increased the mRNA expression levels of the PPARα target genes involved in fatty acid oxidation in the liver and skeletal muscle. Moreover, the adipocyte size in the auraptene‐treated mice was significantly smaller than that in the control HFD‐fed mice resulting in the improvement of HFD‐induced hyperglycemia and abnormalities in glucose tolerance. Conclusions: These findings indicate that auraptene activates PPARα also in vivo and its treatment may improve abnormalities in lipid and glucose metabolisms, suggesting that auraptene is a valuable food‐derived compound for managing metabolic disorders.     

Physiological and psychological evaluations in low- and high-frequency noise using near-infrared spectroscopy

This study aims to evaluate physiological and psychological states using near infrared spectroscopy in noise environments with low or high frequencies. Our system assumes that noise affects brain activity in the frontal lobe. In order to evaluate the subject’s states in a noise environment, we constructed an experimental system that measures the subject’s states. The experimental method adopted here was borrowed from our previous studies. In the present study, we collected experimental data about the subject’s unpleasant or pleasant experiences by producing a noise environment with low and high frequencies. We conclude that noises with low or high frequencies affect our psychological states as well as brain activity in the frontal lobe.