Resveratrol as a new type of DNA-cleaving agent

The first demonstration of DNA cleavage by resveratrol '3,5,4'-trihydroxy-trans-stilbene' is presented. Resveratrol mediated relaxation of pBR322 at micromolar concentrations in the presence of Cu2+. Evidence is provided that resveratrol is capable of binding to DNA, and that the Cu(2+)-dependent DNA damage is more likely caused by a copper-peroxide complex rather than by a freely diffusible oxygen species.     

MR imaging of hepatocellular carcinoma following microwave coagulation therapy

MRI was performed in 13 patients who had microwave coagulation therapy (MCT) for hepatocellular carcinoma. Six of them underwent surgery after MRI. The area (including tumor) treated by MCT showed low to high intensity on T1WI, and low to isointensity on T2WI. No enhancement was obtained on dynamic MRI. Histologically, this area was supposed to be coagulation necrosis. On T1WI, only tumor showed high intensity within the MCT area in 8 patients, and nearly uniform intensity was observed in 5 patients. Histologically, residual cell nuclei were observed in the former, and nearly uniform coagulation necrosis in the latter. The marginal part of the MCT area exhibited low intensity on T1WI, and high intensity on T2WI. Strong enhancement was obtained on dynamic MRI, and histologically, granulation tissue was noted. In the hepatic parenchyma around the MCT area, a ring-or wedge-shaped high intensity part was observed in 7 patients on T2WI, and that part was enhanced on dynamic MRI. This finding was considered to reflect changes such as hepatic hyperperfusion. In terms of the capability of visualizing residual tumor after MCT, MRI was superior to CT. Furthermore, a clear distinction was seen between the MCT area and non-MCT area on T2WI and dynamic MRI. Thus, MRI was useful in the determination of additional therapy.     

Concomitant cardiac and pulmonary operation, the profits of not using cardio-pulmonary bypass

We performed off pump CABG (coronary artery bypass grafting) and right upper lobectomy with R2a lymph nodes dissection on the patient suffered from both lung cancer in the right S1 and stenotic lesion in the left anterior descending artery. Because the coronary lesion was long-segmented one, it was not suitable for percutaneous transluminal coronary angioplasty. To perform absolutely curative operation for the lung cancer, CABG was undergone simultaneously under off pump condition. It is generally feared that the cardiovascular surgery under CPB may have adverse effect for the patient with malignant lesion. Off pump CABG is expected to avoid such disadvantage of CPB, and thought to be suitable method for such a patient as we present above.     

Effects of cigarette smoking on electrodermal orienting reflexes to stimulus change and stimulus significance

Skin conductance responses (SCRs) evoked by novel, signal, and frequent tone stimuli were measured in 20 male heavy smokers and 10 male nonsmokers over two sessions. All smokers abstained from smoking for 12 hr prior to each session. Half of the smokers smoked a cigarette of their preferred brand prior to SCR measurement in the first session, whereas the remaining smokers smoked in the second session. Nonsmokers did not smoke. Results combined across the two sessions indicated that abstinence was associated with selective depression of SCRs to the novel tone. Separate analyses of results from each session revealed that, in the second session, SCRs to both novel and signal tones were depressed in abstinent smokers, partially replicating previous findings. By contrast, first session results showed no significant effects of smoking or abstinence. Results were interpreted in terms of nicotine's effects on nonspecific arousal, with some reservations.     

Conversion of allylic hydroxy oleate to conjugated linoleic acid and methoxy oleate by acid-catalyzed methylation procedures

Conjugated linoleic acid (CLA), a term describing a group of conjugated octadecadienoic acids that are both naturally occurring and formed during food processing, is the subject of considerable current research because of the recently reported antioxidant and anticarcinogenic properties of these compounds. Allylic hydroxy oleates (AHOs), secondary products of lipid autoxidation, have also been found in foods. By means of high-performance liquid chromatography with ultraviolet detection, gas chromatography/mass spectrometry and gas chromatography/matrix isolation/Fourier transform infrared spectroscopy, we determined that currently used acid-catalyzed methylation procedures convert AHOs to CLA and other products that potentially yield high values in determination of CLA in foods. A mixture of AHOs, containing mainly (8- and 11-)hydroxy-9-octadecadecenoates, was synthesized and tested by methylation procedures with the following catalysts: BF₃, HCl, NaOMe and tetramethylguanidine. Both the BF₃ and the HCl procedures converted AHOs to CLA. The base-catalyzed procedures did not convert AHOs to CLA.     

Micromechanics approach to the indentation hardness of glass matrix particulate composites

A theoretical analysis is made of the indentation hardness of glass matrix, particulate composites. It is hypothesized that glass is an elastic-plastic solid on a microscopic scale. Based upon the Marsh theory of indentation, expressions are formulated for indentation hardness of two-phase composites containing spherical particles. When hard particles are dispersed in a soft glass matrix, the overall hardness depends upon the matrix hardness, the volume-fraction of dispersed phase, the elastic properties of the two phases and also the matrix flow stress. On the other hand, when soft particles are dispersed in a hard glass matrix, the hardness and the elastic moduli vary in parallel with the volume-fraction of dispersed phase. Furthermore, the present analysis indicates that the hardness of a composite is independent of the particle size and interparticle spacing if the volume-fraction of the particles is kept constant. Experimental results of the Vickers hardness of phase-separated glasses as well as published hardness data for a glass-ceramic are used for the verification of the theory. The proposed theory explains well the hardness behaviour of such glass matrix composites in terms of the properties and amounts of the individual phases and the microstructural effects.     

Development of the new polymer insulating materials for HVDC cable

The properties of modified HDPE, selected from various polymer materials by evaluations of DC characteristics, were examined in both sheet and cable samples. It was found that the modification, which introduced a small amount of polar group into HDPE, considerably enhanced DC breakdown strength to as high as 1.5-2.0 times those of XLPE (cross-linked polyethylene). Under a poling voltage of up to 30 kV/mm, the modified HDPE exhibits particular behavior, with its space charge decreasing as stress is increasing. In addition, the additives in HDPE have a large influence on space-charge characteristics, thereby affecting the DC breakdown strength. The evaluation of cable insulated with optimum modified HDPE was conducted to determine the breakdown strength under various voltage applications. Compared with the XLPE cable, modified HDPE cable exhibited excellent characteristics under all kinds of voltage applications, particularly DC dielectric breakdown strength, which was almost twice that of XLPE     

Low-temperature polysilicon TFT with two-layer gate insulator usingphoto-CVD and APCVD SiO2

The performance of polysilicon thin-film transistors (TFTs) formed by a 600°C process was improved using a two-layer gate insulator of photochemical-assisted vapor deposition (photo-CVD) SiO₂ and atmospheric-pressure chemical vapor deposition (APCVD) SiO₂. The photo-CVD SiO₂, 100 Å thick, was deposited on polysilicon and followed by APCVD SiO₂ of 1000 Å thickness. The TFT had a threshold voltage of 8.3 V and a field-effect mobility of 35 cm²/V-s, which were higher than those of the conventional TFT with a single-layer gate SiO₂ of APCVD. Hydrogenation by hydrogen plasma was more effective for the new TFT than for the conventional device