Fabrication of high aspect ratio patterns with an aspect ratio larger than 10 is attempted by nano imprint lithography. A fine mold using a chemical vapor deposition (CVD) diamond layer is newly developed by electron cyclotron resonance (ECR) using Cl 2 -O 2 gas. Narrow grooves less than 100 nm in width and 1.0 mm in depth are successfully obtained. Using medium molecular weight PMMA (M w ¼ 350 k) and with slow advance of the cooling sequence in the imprint process, the fatal error of the polymer fracture is eliminated at the mold release process. Based on the advanced process, we first demonstrate the fabrication of high aspect ratio patterns over 20 with 80 nm line width, however, the polymer might be stretched during the mold release process.

We measured force–distance curves of polystyrene (PS)/poly (vinyl methyl ether) (PVME) blend thin films using atomic force microscopy (AFM) in order to pursue the possible usage of AFM as a tool for detecting viscoelastic properties of polymeric materials from a nanoscopic point of view. In quasi-static measurements of force–distance curves for a sample whose PS content equals 100%, both adhesive force and capillary force were measured separately. A phenomenon possibly assigned to pulling off of polymer chains by an AFM tip could also be observed for a sample whose PS content equals 60%. By changing the velocity of the AFM tip acting on a blend sample whose PS content equals 40%, we confirmed that the law of time–temperature reducibility holds even on such a nanoscopic scale. This blend sample behaved as a viscous fluid at room temperature, while its behavior became glassy when faster movements of the AFM tip were applied. A discussion on the future development of a new field of research which should be called “nanorheology" was also presented.

Objectives-To find whether concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in serum increased in workers at municipal incinerators that burn continuously. Methods-30 Workers employed at three municipal waste incineration plants (incinerator workers) and 30 control workers were studied. The incinerator workers had worn dust masks or airline masks during the periodic repair work inside the incinerators. Previous job, dietary habit, smoking habit, distance from residence to the incineration plant, and body weight and height were obtained from a questionnaire

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