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排序方式: 共有316条查询结果,搜索用时 46 毫秒
81.
Stmerin D, a pressurized metered dose inhaler (MDI) for treatment of asthma, contains CFCs (chlorofluorocarbons) as a propellant. For the CFC replacement study, two formulations were prepared using hydrofluoroalkanes (HFA-134a and HFA-227) and the effect of storage on the spray performance was investigated under accelerated stress conditions. Drug stability, moisture content and spray performances such as the emitted dose uniformity and aerodynamic particle size distribution were evaluated. Drug content did not change after 3 months storage at 40 degrees C/75% RH. However, the emitted dose uniformity varied and the respirable fraction (RF) was reduced remarkably. While stored at 40 degrees C/ambient for 3 months, no change was observed in either drug content or spray performances. This study clarified that the moisture content in the canister played an important role on the spray performance, and it changed not only the emitted dose uniformity but also the particle size distribution. Consequently, in order to improve the stability of the spray performance of aerosol prepared with HFAs, moisture permeation into the canister must be controlled. 相似文献
82.
Neya S Imai K Hiramatsu Y Kitagawa T Hoshino T Hata M Funasaki N 《Inorganic chemistry》2006,45(10):4238-4242
The iron complex of a new type of corrphycene bearing two ethoxycarbonyl (-CO2C2H5) groups on the bipyrrole moiety was introduced into apomyoglobin. The reconstituted ferric myoglobin has a coordinating water molecule that deprotonates to hydroxide with a pK(a) value of 7.3 and exhibits 3-10-fold higher affinities for anionic ligands when compared with a counterpart myoglobin with the same substituents on the dipyrroethene moiety. In the ferrous state, the oxygen affinity of the new myoglobin was decreased to 1/410 of the native protein. The anomalies in the ligand binding, notably dependent on the side-chain location, were interpreted in terms of a characteristic core shape of corrphycene that produces the longer and shorter Fe-N(pyrrole) bonds. The spin-state equilibrium analysis of the ferric azide myoglobin containing the new iron corrphycene supported the nonequivalence of the Fe-N(pyrrole) bonds. These results demonstrate that the trapezoidal molecular shape of corrphycene exerts functional significance when the iron complex is placed in a protein pocket. 相似文献
83.
84.
Satoshi Takeuchi Saburo Endo Taizo Irie 《Journal of Physics and Chemistry of Solids》1985,46(8):887-893
Near infrared absorption spectra of n-type CuIn5S8 single crystals were measured. Two structures were found in the spectra in the photon energy range from ?ω ? 0.3 eV?1.2 eV. One of them is the free carrier absorption below 0.6 eV in which the absorption coefficient increases as the third power of the wavelength. It was found that this absorption was associated with the multiple scattering mechanisms. Another structure seems, from its temperature and carrier-concentration dependences, to be associated with an absorption due to a transition from a lower lying conduction band to an upper one. 相似文献
85.
Y. Homma M. Nakada A. Nakamura S. Nasu D. Aoki H. Sakai S. Ikeda E. Yamamoto Y. Haga Y. Ōnuki Y. Shiokawa 《Hyperfine Interactions》2006,168(1-3):1175-1179
57Fe and 237Np Mössbauer ōmeasurements have been performed for NpFeGa5, which is one of the so-called neptunium 1-1-5 compounds. The 57Fe Mössbauer spectra below T N = 118 K show the magnetically ordered state. The magnitude of the hyperfine magnetic field at the 57Fe nucleus is determined to be 1.98 ± 0.05 T at 10 K. From the 237Np Mössbauer spectrum at 10 K, the hyperfine magnetic field at the 237Np nucleus is 203 T and the hyperfine coupling constant is determined to be 237 T/μB using the Np atomic magnetic moment of 0.86 μB determined by the neutron diffraction study. 相似文献
86.
Shoji Kitamura Saburo Endo Taizo Irie 《Journal of Physics and Chemistry of Solids》1985,46(8):881-885
The electrical resistivity and Hall coefficient of n-type CuIn5S8 single crystals were measured in the temperature range from 80 K–500 K. The energy gap at 0 K was determined to be 1.4 eV. The donor levels at 0.017 eV and 0.09 eV below the conduction band are identified. The mobility data are analysed assuming scatterings by acoustic and polar optical phonons and ionized impurities. 相似文献
87.
Shoichi Hayashida Saburo Imamura 《Journal of polymer science. Part A, Polymer chemistry》1995,33(1):55-62
The molecular structure of the hydrolyzate, and of the prepolymers and polymerization products of phenyltrichlorosilane and diphenyldichlorosilane are investigated. 29Si-NMR measurements reveal the kinds of component units and their ratio in each synthesis step. The molecular structure of the prepolymer chain end and the polymerization product are also discussed in relation to the change in the NMR spectra. © 1995 John Wiley & Sons, Inc. 相似文献
88.
Makoto Masuda Satoru Takamatsu Noriyuki Nishimura Saburo Komatsubara Tetsuya Tosa 《Applied biochemistry and biotechnology》1992,37(3):255-265
Serratia marcescens T-2000 was previously reported to be an l-threonine-producing strain that harbors the recombinant plasmid carrying the mutant-type
threonine operon. This strain produced 55 g of l-threonine/L of the medium containing urea as a nitrogen source after 72 h
of cultivation. In the urea-containing medium, transitory stop of the growth was observed during the early period of cultivation
when the entire amount of ammonium ion formed from urea via heat decomposition disappeared in the medium. This indicated that
the shortage of ammonium supply in cells might delay both the cell growth and the l-threonine production. The use of ammonia
water as a nitrogen source for l-threonine production was therefore studied, because microbial cells generally assimilate
this source more readily than urea. When ammonia water was automatically fed to the medium so as to maintain the pH of the
medium at around 7, the growth was accelerated, and the l-threonine production reached a maximum of 65 g/L at 48 h. Under
these conditions, sucrose, a carbon source, was continuously fed to the medium, resulting in the production of 100 g of l-threonine/L
at 96 h. Thus, the l-threonine productivity of the recombinant l-threonine-producing strain could be increased by devising
the method for supply of a nitrogen source. 相似文献
89.
90.
Yoshtnori Shichida Takayoshi Kobayashi Hiroyuki Ohtani Tôru Yoshizawa Saburo Nagakura 《Photochemistry and photobiology》1978,27(3):335-341
Abstract. Squid rhodopsin extracted with 2% digitonin (pH 10.5 or 7.0) was excited with a 347 nm light pulse from a mode-locked ruby laser at room temperature. Within 19 ps after the excitation, absorbance at 430 nm due to hypsorhodopsin increased and subsequently decreased with a decay time of 45 ± 10 ps. Absorbance at 550 nm due to bathorhodopsin increased with a rise time of 50 ± 10 ps. These results are the first observations of hypsorhodopsin at room temperature and clearly show that hypsorhodopsin is a precursor of bathorhodopsin which has been considered to be the earliest photoproduct in the photobleaching process of rhodopsin.
Hypsorhodopsin appeared with a rise time of 70 ± 10 ps at 421 nm at liquid nitrogen temperature without any bathorhodopsin being observed during the formation of hypsorhodopsin. An experiment using an N2 laser showed that squid bathorhodopsin converted to lumirhodopsin with a decay time of about 300 ns at room temperature. 相似文献
Hypsorhodopsin appeared with a rise time of 70 ± 10 ps at 421 nm at liquid nitrogen temperature without any bathorhodopsin being observed during the formation of hypsorhodopsin. An experiment using an N