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111.
112.
[structure: see text] 8,11-Dideoxytetrodotoxin, an unnatural tetrodotoxin analogue, was synthesized in a highly stereoselective manner from a common intermediate in our synthetic studies on tetrodotoxin. The synthesis features neighboring group participation of trichloroacetamide for stereoselective hydroxylation, protection of ortho ester, and guanidine installation with Boc-protected isothiourea. 相似文献
113.
Electronic states of P donors in Si nanocrystals (nc-Si) embedded in insulating glass matrices have been studied by electron spin resonance. Doping of P donors into nc-Si was demonstrated by the observation of optical absorption in the infrared region due to intraconduction band transitions. P hyperfine structure (hfs) was successfully observed at low temperatures. The observed splitting of the hfs was found to be much larger than that of the bulk Si:P and depended strongly on the size of nc-Si. The observed strong size dependence indicates that the enhancement of the hyperfine splitting is caused by the quantum confinement of P donors in nc-Si. 相似文献
114.
Itaru Hibino Minoru Okita Takayuki Inoue Yasuhiro Banno Masahiro Hoso 《Physical Therapy Research》2008,11(1):1-6
Immobilization is often associated with decreased muscle elasticity. This condition is known as muscle contracture; however, the mechanism remains unclear. The purpose of this study was to clarify the mechanism governing muscle contracture in rat soleus muscle by identifying changes in ankle joint mobility, insoluble collagen concentration and type I and type III collagen isoforms following 1- and 3-week immobilizations. Following a 1-week immobilization, range of motion (ROM) of dorsiflexion declined to 90% of the control value; additionally, ROM dropped to 67.5% of the control value after a 3-week immobilization. This finding suggested that ankle joint mobility decreases in conjunction with extended periods of immobilization. Insoluble collagen concentration in soleus muscles, which was unchanged after 1 week of immobilization, increased 3 weeks after immobilization. These results may be indicative of collagen fibers with strong intermolecular cross-links contained in the muscle was made increased relatively by 3 weeks of immobilization. Therefore, the change in intermolecular cross-links may be significant in terms of progress of muscle contracture with longer periods of immobilization. On the other hand, the ratio of type III to type I collagen isoforms in muscular tissue increased following a 1-week immobilization; moreover, this ratio remained constant after 3 weeks of immobilization. These data suggested that muscle immobilization may induce type III collagen isoform expression. The increase in the ratio of type III to type I collagen isoforms do not change in parallel with the increase in the limitation in ROM; however, this phenomenon probably is not closely related to the progress of muscle contracture. The change of collagen isoform in immobilized muscle may be involved in the mechanism governing the progression of muscle fibrosis. 相似文献
115.
Hiroshi Maejima Yuji Kanetada Hitoshi Sunahori Azusa Murase Takuya Otani Nozomi Sakamoto Osamu Yoshimura Yoshiko Tobimatsu 《Physical Therapy Research》2008,11(1):7-13
The objective of this study was to assess the effect of comprehensive exercise program widely accepted as a community-based physical intervention for the prevention of falling in the elderly persons on their controlling standing balance. Twenty-six community-dwelling elderly persons (13 males and females; 69.8 ± 2.8 years old) participated in this study. Daily exercise was comprised of walking for more than 30 min, stretching, muscle strengthening and balance exercise without exercise equipments. The intervention was continued for three months. Indicators of standing balance related to static balance, dynamic balance and postural response were measured before and after the intervention. As an effect of the intervention on static balance, the sway of center of pressure (COP) in the static stance significantly increased. In the dynamic balance, significant improvements were observed in one leg standing time, the 10-m gait time, functional reach. Additionally, the maximal movable length of COP which subjects can move voluntarily to right and left significantly increased. In the postural response, the integrated electromyography (IEMG) induced by postural response for sudden postural perturbation significantly decreased in the lower leg muscles. Since less muscular activities were sufficient to maintain posture, it was suggested that postural response was elicited more efficiently following the intervention. This study suggested that the comprehensive exercise program, which has been widely introduced as community-based interventions for the prevention of falling, have extensive effects on the control of standing balance covering static balance, dynamic balance and postural response in the elderly persons. 相似文献
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117.
Minoru Kumakura Masaru Yoshida Isao Kaetsu 《Applied biochemistry and biotechnology》1978,3(3):175-183
The immobilization ofStreptomyces phaeochromogenes cells was studied by the radiation-induced polymerization of various hydrophobic glass-forming monomers at low temperatures. The glucose isomerase activity of cells immobilized in hydrophobic polymers showed no decrease in activity with repeated use (batch enzyme reaction). Activity increased with increasing monomer concentration in contrast to results with the immobilized enzyme. The hydrophobic polymer composite was microspheric in form. The particle diameter of the composite increased with the increasing monomer concentration.K m values of the immobilized cells were close to that of intact cells. It was deduced that the cells were trapped on the surface part of the hydrophobic polymer ready to react with the substrate, and not within the matrix where diffusion would play an important role in reaction rates. 相似文献
118.
Acyclic asymmetric induction was achieved in >99 % formation via coordinated intermediate () in the heteroconjugate addition ( to ); the heteroatom in the adduct being used for elongation of the carbon chain toward maytansine ). 相似文献
119.
Koichi Funazo Takayuki Hirashima Minoru Tanaka Toshiyuki Shono 《Fresenius' Journal of Analytical Chemistry》1982,311(1):27-29
Summary A method is described for the determination of sulphide ion in aqueous samples by gas chromatography. Sulphide is ethylated with diethyl sulphate and the resulting diethyl sulphide is extracted with chloroform and determined with a gas chromatograph equipped with a flame ionization or a flame photometric detector. In the case of a flame photometric detector, the detection limit for sulphide ion is 0.05 g/ml. Other anions commonly found with sulphide ion do not interfere. Sulphide ion in spring waters was analysed by this new method and for comparison also by colorimetry (methylene blue). The results revealed the reliability of the new method.
Bestimmung von Sulfidspuren durch Ethylierung und Gas-Chromatographie
Zusammenfassung Sulfid wird mit Diethylsulfat ethyliert, das gebildete Diethylsulfid mit Chloroform extrahiert und gaschromatographisch mit Hilfe eines Flammenionisationsoder eines flammenphotometrischen Detektors bestimmt. Die Nachweisgrenze beträgt 0,05 g S/ml für den FPD. Anionen, die üblicherweise mit Sulfid zusammen vorkommen, stören nicht. Das Verfahren wurde, im Vergleich mit der colorimetrischen Methylenblaumethode, auf Quellwasser angewendet. Es wurde gute Übereinstimmung der Ergebnisse erzielt.相似文献
120.