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排序方式: 共有1301条查询结果,搜索用时 15 毫秒
1.
BS Kendrick BS Chang T Arakawa B Peterson TW Randolph MC Manning JF Carpenter 《Canadian Metallurgical Quarterly》1997,94(22):11917-11922
Understanding the mechanism for sucrose-induced protein stabilization is important in many diverse fields, ranging from biochemistry and environmental physiology to pharmaceutical science. Timasheff and Lee [Lee, J. C. & Timasheff, S. N. (1981) J. Biol. Chem. 256, 7193-7201] have established that thermodynamic stabilization of proteins by sucrose is due to preferential exclusion of the sugar from the protein's surface, which increases protein chemical potential. The current study measures the preferential exclusion of 1 M sucrose from a protein drug, recombinant interleukin 1 receptor antagonist (rhIL-1ra). It is proposed that the degree of preferential exclusion and increase in chemical potential are directly proportional to the protein surface area and that, hence, the system will favor the protein state with the smallest surface area. This mechanism explains the observed sucrose-induced restriction of rhIL-1ra conformational fluctuations, which were studied by hydrogen-deuterium exchange and cysteine reactivity measurements. Furthermore, infrared spectroscopy of rhlL-1ra suggested that a more ordered native conformation is induced by sucrose. Electron paramagnetic resonance spectroscopy demonstrated that in the presence of sucrose, spin-labeled cysteine 116 becomes more buried in the protein's interior and that the hydrodynamic diameter of the protein is reduced. The preferential exclusion of sucrose from the protein and the resulting shift in the equilibrium between protein states toward the most compact conformation account for sucrose-induced effects on rhIL-1ra. 相似文献
2.
T Noda M Arakawa T Takaya T Nagano K Kagawa H Miwa S Hirakawa 《Canadian Metallurgical Quarterly》1993,14(7):876-884
To evaluate right atrial (RA) contractile performance in patients with myocardial infarction, we validated a cineangiographic method of RA volume measurement, and investigated RA volume change in 'normal' individuals and patients with a previous myocardial infarction. Sixteen silicone rubber RA casts made from human cadavers were filmed in the postero-anterior and left lateral projections. The cast volumes calculated following Simpson's rule were in good agreement with those measured by water replacement (r = 0.992, P < 0.01). At cardiac catheterization, biplane RA cineangiography was performed in 19 'normal' individuals (N group), in 14 patients with a previous antero-septal infarction (AMI group) and in seven patients with a previous inferior infarction (IMI group). The RA volume-time curve was constructed at 20-40 ms intervals for one cardiac cycle. RA volume at the beginning of the atrial contraction (RAVd), which was defined as the 'preload' of the RA, tended to be larger in both the AMI and IMI groups compared with 'normal' individuals. The RA ejection volume was significantly larger in both the AMI (18.4 +/- 2.1 ml.m-2, P < 0.01) and IMI groups (19.4 +/- 2.8, P < 0.01) than in the N group (14.5 +/- 1.9), even for a comparable level of RAVd (range from 26 to 36 ml.m-2) (18.6 +/- 2.1, P < 0.01, 18.2 +/- 2.0, P < 0.01, 14.7 +/- 1.9, respectively). These results suggest that RA contraction increases in patients with myocardial infarction by increasing both the 'preload' and 'contractility' of the RA. 相似文献
3.
Masaru Kadoshima Masahiko HirataniYasuhiro Shimamoto Kazuyoshi ToriiHiroshi Miki Shinichiro KimuraToshihide Nabatame 《Thin solid films》2003,424(2):224-228
We investigated rutile-type titanium dioxide (TiO2) films for possible use as a high-k gate insulator. The TiO2 thin films were directly deposited on Si substrates using a RF magnetron sputtering method with a sintered oxide target. A single phase of rutile-type TiO2 whose dielectric constant of approximately 75 was obtained when the film was deposited in an inert gas atmosphere and annealed at 800 °C in an oxidizing gas atmosphere. The oxygen ions were deficient in the as-deposited film, and consequently, a sufficient oxygen supply was needed to crystallize the film to a single phase of rutile during the post-annealing. However, the interfacial SiO2 layer between the TiO2 and the Si substrate simultaneously grew thicker than 2 nm. As the interfacial SiO2 grew, the leakage current was decreased and the equivalent oxide thickness was increased, in the Au/rutile-type TiO2/Si capacitor. Therefore, we concluded that the growth of the interfacial SiO2 layer thicker than 2 nm is inevitable to form the single phase of rutile-type TiO2 and to decrease the leakage. 相似文献
4.
Infrared (IR) detecting elements were prepared using positive temperature coefficient (PTC) thermistors with large temperature
coefficients of resistivity (α). Their compositions were denoted as Ba1−x
Sr
x
Nb0.003Ti0.997O3 + 1 mol % TiO2 + 0.07 mol %MnO (x=0, 0.2), and their temperature coefficients of resistivity were 78 and 50% K−1, respectively. Their IR sensing properties were measured under the self-regulating heating conditions, and were compared
with those of a detector with small α (18 % K−1). It was shown that large α was effective for controlling the element temperature by self-regulating heating and for improving
sensitivity. The responsivity,R
v
of the element withx=0.2 was 980 VW−1, and was as large as those of pyroelectric detectors. Expressions which normalize the sensitivity and the thermal time constant
were derived. From these expressions, criteria for improving some IR sensing properties were obtained. 相似文献
5.
A novel signal processing technique based on fuzzy rules is proposed for estimating nonstationary signals, such as image signals, contaminated with additive random noises. In this filter, fuzzy rules concerning the relationship between signal characteristics and filter design are utilized to set the filter parameters, taking the local characteristics of the signal into consideration. The fuzzy rules are found to be quite effective, since the rules to set the filter parameters are usually expressed in an ambiguous style. The high performance of this filter is demonstrated in noise reduction of a 1-D test signal and a natural image with various training signals 相似文献
6.
Nobuo Masaki Tetsuo Yoshida Masaru Miyagawa Iawo Ohshima Kikuo Matsuzawa 《Electrical Engineering in Japan》1992,112(2):58-70
A second-generation model of cubicletype gas-insulated switchgear (C-GIS) with composite insulation incorporating SF6 gas has been developed. The design does not require a gas process in field assembly; it has high reliability and its installation is more rapid; and a further reduction in size is achieved. The design principles are described in detail. 相似文献
7.
Recently, progress has been made in the Generalized Multi-Protocol Label Switching (GMPLS) and Automatic Switched Optical
Networks (ASON) standardizations. These technologies realize construction of large-scaled optical networks, interconnections
among single-domain Wavelength Division Multiplexing (WDM) networks, and direct communication over multi-domain WDM networks.
Meanwhile, it is known that the topology of the Internet exhibits the power-law attribute. Since the topology of the Internet,
which is constructed by interconnecting ASs, exhibits the power-law, there is a possibility that large-scale WDM networks,
which are constructed by interconnecting WDM networks, will also exhibit the power-law attribute. One of the structural properties
of a topology that adheres to the power-law is that most nodes have just a few links, although some have a tremendous number
of them. Another property is that the average distance between nodes is smaller than in a mesh-like network. A natural question
is how such a structural property performs in WDM networks. In this paper, we first investigate the property of the power-law
attribute of physical topologies for WDM networks. We compare the performance of WDM networks with mesh-like and power-law
topologies, and show that links connected to high-degree nodes are bottlenecks in power-law topologies. To relax this, we
introduce a concept of virtual fiber, which consists of two or more fibers, and propose its configuration method to utilize
wavelength resources more effectively. We compare performances of power-law networks with and without our method by computer
simulations. The results show that our method reduces the blocking probabilities by more than one order of magnitude. 相似文献
8.
9.
10.
Uchiyama K. Arakawa F. Narita S. Aoki H. Kawasaki I. Matsui S. Yamamoto M. Nakagawa N. Kudo I. 《Micro, IEEE》1993,13(5):12-22
The Gmicro/500, which features a RISC-like dual-pipeline structure for high-speed execution of basic instructions and represents a significant advance for the TRON architecture, is presented. Upwardly-object-compatible with earlier members of the Gmicro series, this microprocessor uses resident dedicated branch buffers to greatly enhance branch instruction execution speed. Its microprograms simultaneously use dual execution blocks to execute high-level language instructions effectively. Fabricated with a 0.6-μm CMOS technology on a 10.9-mm×16-mm die, the chip operates at 50/66 MHz and achieves a processing rate of 100/132 MIPS 相似文献