A quartz crystal microbalance simulation to examine the effect of ultraviolet light treatment on characteristics of polyethylene surface

The effect of ultraviolet light irradiation on the characteristics of the polyethylene (PE) surface was investigated by the quartz crystal microbalance (QCM) technique. The PE film was prepared on the gold electrodes of the QCM by spin-coating from the solution and then was treated by the excimer UV lamp in ambient air. The changes in the hydrophilic properties, moisture adsorption, and water retention of the PE film due to the UV irradiation were determined from the frequency change of the QCM. To evaluate the detergency of the PE film, stearic acid as model oily soil was deposited onto the PE film formed on the QCM by the Langmuir-Blodgett (LB) technique, and was ultrasonically cleaned in aqueous detergent solutions containing ethanol or surfactant. The removal efficiency obtained from the frequency change of the QCM was found to increase considerably after the UV irradiation. From independently determined contact angles and the surface free energy components of the PE film, the free energy change resulting from the penetration of the detergent solution between stearic acid and PE in the zone of contact was calculated. Good relation was found between the removal efficiency and the free energy change, indicating that the increase in the detergency of the PE surface by UV irradiation was explained by surface energetics.     

Pheromone Analysis of Wild Female Moths with a PBAN C-Terminal Peptide Injection for an Estimation of Assortative Mating in Adzuki Bean Borer, Ostrinia scapulalis

The adzuki bean borer, Ostrinia scapulalis, has distinct genetic variation in the blend of two sex pheromone components, (E)- and (Z)-11-tetradecenyl acetates. This variation is largely controlled by a single autosomal locus with two alleles, E and Z. E-type (EE) females produce a pheromone with a mean E:Z ratio at 99:1 whereas Z-type (ZZ) and I-type (ZE) produce pheromones with mean of 3:97 and 64:36, respectively. Interestingly, in many natural populations of O. scapulalis in Japan, this pheromone polymorphism appears to be stably maintained. We tried to predict the changes in relative abundance of each pheromone type by estimating the pheromone production genotype of wild females and their male mates. The pheromone titer in the wild, mated females was increased without changing the blend ratio by an injection of a peptide with pheromone biosynthesis activating activity (TKYFSPRL-NH2). The frequencies of E-, I-, and Z-types at Matsudo were 15, 52, and 33%, respectively, and did not deviate from the Hardy-Weinberg expectations. The estimated mating patterns were concordant with the assumption that no assortative mating was occurring in this population, and this is suggested as a cause of sustained polymorphism at Matsudo.     

Cupric ion-dependent inhibition of lysosomal acid cholesteryl ester hydrolase in the presence of hydroxylamine

In the presence of hydroxylamine or ascorbic acid, the inhibitory effects of Cu²⁺ on lysosomal acid cholesteryl ester hydrolase (acid CEH) partially purified from rat liver were studied. Hydroxylamine stimulated the inhibition of acid CEH activity by Cu²⁺ but not that by Zn²⁺, Fe²⁺, Co²⁺, Mn²⁺, Ca²⁺, Mg²⁺ and Hg²⁺. This Cu²⁺-dependent inhibition of acid cholesterol ester hydrolase (CEH) activity was completely prevented by ethylenediamine tetraacetic acid (EDTA), EGTA and o-phenanthroline, a chelator with a stability constant for Cu²⁺, and also by sulfhydryl agents and cytoplasmic reducing agents such as cysteine, glutathione and mercaptoethanol. In addition, the stimulative effects of hydroxylamine on Cu²⁺-dependent inhibition were maintained even after preincubation of Cu²⁺ with hydroxylamine. On the other hand, ascorbic acid was found to replace the stimulation by hydroxylamine of the Cu²⁺-dependent inhibition of acid CEH activity but the effects of ascorbic acid progressively became smaller with prolongation of the preincubation time. Moreover, addition of chemical radical scavengers to the reaction mixture did not prevent the Cu²⁺-dependent inhibition of acid CEH activity in the presence of ascorbic acid. These results suggest that Cu²⁺ causes inhibition of lysosomal acid CEH activity through the formation of Cu¹⁺ in a reductive medium.     

Radiation-induced grafting of N,N-dimethylacrylamide onto polytetrafluoroethylene

Grafting of N,N-dimethylacrylamide (DMAA) onto polytetrafluoroethylene (PTFE) has been carried out by using gamma rays from a ⁶⁰Co source. Degree of grafting was affected by grafting conditions. Especially, solvent for the grafting was found to be a very significant parameter to obtain a higher grafting yield. When ethylacetate or acetone was used as the solvent, grafting yield greater than 5% was obtainable while the graftcopolymerization scarcely occurred in the presence of other kinds of solvent such as ethanol or water. Apparent activation energy of the grafting in ethylacetate was calculated to be 7.90 Kcal/mol, and initial grafting rate of it was proportional to 0.55 power of dose rate.     

Direct intracerebral invasion from skull metastasis of large cell lung cancer

A 56-year-old Japanese woman was referred to us for the treatment of lung cancer. On admission, the patient showed multiple bone metastases, including the skull, without brain metastasis. During chemoradiotherapy for the primary tumor and bone metastasis involving the thoracic spine, she suffered a fatal intracerebral hemorrhage. Since the patient had no risk factors for intracerebral hemorrhage, the skull bone metastasis was thought to be responsible for this event. At autopsy, penetration of the metastatic tumor from the skull bone into the dura, with direct invasion of the brain tissue, was confirmed histologically. A hematoma also was identified at the same site adjacent to the skull bone metastasis. To our knowledge, direct tumor invasion to the brain from a skull metastasis of non-small cell lung cancer has not been previously reported.