Shorter-wavelength lithography utilizing MRS-type negative resists

New negative photoresists, called MRS-type resists, are successfully applied to deep-UV 1:1 projection printing and 365 nm 10:1 reduction projection printing. The MRS-type resists are characterized by intense absorption of exposure light and absence of swelling in aqueous developer solutions. They resolve steep profile submicron images in a 1.0 μ thick film. They are not adversely affected by reflected light from water surfaces. In order to use MRS-type resists with broader development latitude, optimizing the extent of light absorption is important because the resist profiles strongly depend on development conditions due to increasing solubility towards the resist bottom.     

Identification of two palmitoyl groups in octopus rhodopsin

We determined the structure and site of fatty acid incorporated in octopus rhodopsin using a combination of fluorescence label and enzymatic cleavage methods in conjunction with fast-atom bombardment (FAB) mass spectrometry. A single peptide containing two adjacent cysteines, Cys337 and Cys338, was successfully isolated using the fluorescence from a dye conjugated to Cys345. The FAB mass spectrometric analysis of the peptide (323Phe-340Phe) revealed that two palmitoyl groups are linked to Cys337 and Cys338 via thioester bonds in octopus rhodopsin as in bovine rhodopsin.     

Effect of oxygen on the wettability of sapphire by liquid palladium

The surface tension of liquid palladium and the contact angle between liquid palladium and sapphire have been measured at 1833 K as a function of oxygen pressure by the sessile drop method. Oxygen acted as a surface-active element on the surface of liquid palladium and at the interface between liquid palladium and sapphire, resulting in the decrease of the surface tension and the contact angle. The work of adhesion calculated from their values increased with increasing oxygen pressure, and had a constant value above 400 Pa. The maximum excess concentration of oxygen was estimated to be 7.3×10^–6 mol m^–2 for the surface and 6.9×10^–6 mol m^–2 for the interface.     

Photoinduced Formation of Small Gold Particles in Silica Gels

AuCl⁻₄ ions in sol-gel-derived silica gels (Au/silica gels) were photoreduced by ultraviolet light irradiation at room temperature. In the presence of ethylene glycol in the silica gels, small Au particles were effectively formed by the irradiation. When the storage temperature of the gels was increased in the dark after the irradiation, the surface plas-mon resonance absorption peak of the Au particles was shifted to longer wavelengths, indicating that the Au particles became large. At a storage temperature below 9°C, Au particles could not be observed in the silica gels. The apparent activation energy of Au particle formation was estimated to be 17. 3 kcal·tmol⁻¹.     

Analysis of enoyl-coenzyme A hydratase activity and its stereospecificity using high-performance liquid chromatography equipped with chiral separation column

Enoyl-coenzyme A (CoA) hydratase catalyzes the hydration of trans-2-enoyl-CoA to yield 3-hydroxyacyl-CoA during fatty acid degradation (β-oxidation). Although much research has focused on the stereospecificities of 2-enoyl-CoA hydratases, a direct quantification of the production of 3(R)- and 3(S)-hydroxyacyl-CoA has not yet been established. Therefore, we developed a method of concurrently quantifying 3(R)- and 3(S)-hydroxyacyl-CoA using high-performance liquid chromatography (HPLC) equipped with a chiral separation column. The optimized conditions for the separation of 3(R)-, 3(S)-hydroxyhexadecanoyl-CoA and trans-2-hexadecenoyl-CoA, were determined to be as follows: mobile phase of 35/65 (v/v) of 50 mM phosphate buffer (pH 5.0)/methanol; flow rate of 0.5 mL/min; detection at 260 nm; and column temperature of 25°C. This method was applied to subcellular fractions of rat liver; the results directly confirmed that 3(S)-hydroxyhexadecanoyl-CoA is the dominant product obtained from the heat-stable enoyl-CoA hydratase-catalyzed reaction of trans-2-hexadecenoyl-CoA. Finally, the stereospecificities of L-bifunctional protein (L-BP) and D-bifunctional protein (D-BP) were reinvestigated using this method, and it was confirmed that L- and D-BP yielded 3(S)- and 3(R)-hydroxyhexadecanoyl-CoA were yielded from trans-2-hexadecenoyl-CoA, respectively. 3(R)-Hydroxyacyl-CoA is a peroxisomal β-oxidation-specific intermediate. Therefore, this method is potentially useful not only studies regarding the stereochemistry of enoyl-CoA hydratase but also for the diagnosis of diseases caused by defects of peroxisomal enoyl-CoA hydratase.     

A new family of heparin-binding growth/differentiation factors: increased midkine expression in Wilms' tumor and other human carcinomas

Midkine (MK) and heparin-binding growth-associated molecule/pleiotrophin form a new family of heparin-binding growth/differentiation factors. We studied MK gene expression in human tumors. In normal human reference tissues, MK was highly expressed in the mucosal tissue of the small intestine, moderately in the thyroid, weakly in the tissues of the lung, colon, stomach, kidney, and spleen, and not at all in the liver. All of 6 surgically removed specimens of Wilms' tumor highly expressed MK. Also, a moderate to intense level of MK expression was noted in the majority of surgically removed hepatocellular carcinomas. The MK mRNA level was analyzed in a number of cultured and nude mice-transplanted lines of human tumors. In stomach, colon, pancreatic, lung, and esophageal carcinomas, a moderate to high level of MK expression was found in the majority of them. These results suggest an important role of MK in the development and/or biological behavior of tumors and raised a possibility to use MK as a diagnostic marker. Heparin-binding growth associated molecule/pleiotrophin mRNA was low or scarcely detectable in samples analyzed thus far except for significant levels of the expression that were observed in PA-1 teratocarcinoma cells and in some surgical specimens of Wilms' tumor.     

Ultrathin Organic Electrochemical Transistor with Nonvolatile and Thin Gel Electrolyte for Long‐Term Electrophysiological Monitoring

Skin‐based electrical‐signal monitoring is one of the basic and noninvasive diagnostic methods for observing vital signals that contain valuable information about the dynamic status of the inner body. Soft bioelectronic devices are developed for the acquisition of high‐quality biosignals by taking advantage of their inherent thin and soft bodies. Among these devices, the organic electrochemical transistor (OECT) is a promising local transducing amplifier because of its key advantages, such as low operating voltage, high transconductance, and biocompatibility. However, the transistor's direct electrolyte‐gated operation limits its ability to measure biosignals only when the electrolyte exists. Here, an ultrathin OECT‐based wearable electrophysiological sensor based on a thin (≈6 µm) and nonvolatile gel electrolyte is reported, which can operate on dry biological surfaces. This sensor can measure biopotentials with a high mechanical stability and high signal‐to‐noise ratio (24 dB) even from dry surfaces of the human body and also shows stable performance during long‐term continuous monitoring and multiple reuse in a test that lasted more than a week.     

Recombination of Spin Polarized Atomic Hydrogen Adsorbed on a Dilute 3He-4He Mixture

We have been searching for two-dimensional (2-D) superfluidity of spin-polarized atomic hydrogen (H) adsorbed on liquid helium surface. We have investigated H adsorbed on ³ He- ⁴ He mixtures instead of pure ⁴ He because the thermal coupling of H to the mixtures is stronger than ⁴ He. ESR at 129 GHz was carried out to detect H at 4.5 T by using the Fabri-Perot confocal cavity with the cold spot located at the confocal point and thus the 2-D H signal was effectively detected. We investigated the two-body bulk and surface recombination processes of H on a 3% ³ He ³ He- ⁴ He mixture film. From the analysis of the surface recombination process, we found the adsorption energy of H was a 0.6 K for the mixture film in the temperature range between 120 mK and 250 mK, greater than the 0.3–0.4 K found previously for pure ³ He and a 67% ³ He ³ He- ⁴ He mixture.     

Risk hedging against the fuel price fluctuation in energy service business

Energy service business, or energy service company (ESCO), is expanding among industrial users as a means of energy saving. The ESCO business normally tends to become a long-term operation. During the operation, fluctuations of fuel and electricity costs significantly impact on the stability of the profit from ESCO business. Therefore, it is essential to reduce the risk of fuel and electricity cost fluctuations. Generally, a transaction called “financial derivative” is used as a measure of hedging against the fuel price fluctuation. In the case of ESCO business, it is necessary to manage the risk of both electricity and fuel price fluctuations because the variation in electricity price strongly affects the profit from ESCO as that in fuel price does.