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151.
T Tamada K Kitadokoro Y Higuchi K Inaka A Yasui PE de Ruiter AP Eker K Miki 《Canadian Metallurgical Quarterly》1997,4(11):887-891
Micronutrient deficiencies probably have few direct effects on the functioning of immune cells. The main effect appears to be a reduction in cell mass that may indirectly affect immune cell function, particularly where T helper cell numbers are reduced. Results of many human studies are contradictory. Some of this contradiction may be accounted for by the fact that disease may lower concentrations of micronutrients in plasma that may be misinterpreted as deficiency. Low plasma vitamin A concentrations however appear to impair immune responsiveness and have deleterious effects on membrane integrity and mucosal function. Zinc may have similar effects on gut integrity and appears to be particularly useful in the treatment of acute diarrhoea. Low concentrations of other nutrients such as ascorbate and iron, may not necessarily impair immune function. Low plasma ascorbate may assist the removal of iron from plasma and low iron concentrations appear to increase the cytotoxicity of macrophages. 相似文献
152.
John A. Rose Mitsunori Takano Masami Hagiya Akira Suyama 《Genetic Programming and Evolvable Machines》2003,4(2):139-152
An in vitro domainal shuffling strategy for protein evolution was proposed in (J. Kolkman and W. Stemmer, Nat. Biotech.
19 (423) 2001). Due to backhybridization, however this method appears unlikely to be an efficient means of iteratively generating
massive libraries of combinatorially shuffled genes. Recombination at the domain level (30–300 residues) also appears too
coarse to support the evolution of proteins with substantially new folds. In this work, the module (10–25 residues long) and
pseudomodule are adopted as the fundamental units of protein structure. Each protein is modelled as an N to C-terminal tour
of a digraph composed of pseudomodules. An in vitro method based on PNA-mediated Whiplash PCR (PWPCR), RNA-protein fusion, and restriction-based recombination, XWPCR is then
presented for evolving proteins with a high affinity for a given motif, subject to the constraint that each corresponds to
a walk on the pseudomodule digraph of interest. Simulations predict that PWPCR is an efficient method of producing massive,
shuffled gene libraries encoding for proteins as long as roughly 600 residues. 相似文献
153.
An ultra thin layer of germanium oxide with mono-atomic order thickness was prepared by chemical vapor deposition (CVD) of germanium alkoxide on γ-alumina; the structure was analyzed by benzaldehyde-ammonia titration, extended X-ray absorption fine structure (EXAFS) and infrared spectroscopy. The mono-atomic layer showed Brønsted acidity, like the silica monolayer. 相似文献
154.
K Shiraki M Moriwaki M Matsumoto N Yanagihara T Yasunari T Miki 《Canadian Metallurgical Quarterly》1997,21(5):245-253
BACKGROUND: The severe types of central serous chorioretinopathy (CSC) have a chronic nature, suggesting that a pathological process persists subclinically. Indocyanine green (ICG) angiography recently revealed intrachoroidal dye leakage and its static nature in CSC. As the intrachoroidal dye leakage was suspected to be relevant to the disease process, the long-term persistence of intrachoroidal ICG leakage was examined in four patients of the severe types of CSC. METHODS: ICG angiography was performed periodically over more than three years in three patients and two years in one patient. One patient had CSC with bullous retinal detachment, and the other three had chronic CSC or diffuse retinal pigment epitheliopathy. RESULTS: Intrachoroidal ICG leakage persisted in all the patients. However, a change in location of persistent intrachoroidal leakage or disappearance of intrachoroidal leakage regardless of no progression of retinal pigment epithelial alteration was noted in one eye of two patients. CONCLUSIONS: Pathology causing intrachoroidal ICG leakage persisted subclinically for a long period. However, location and extent of the intrachoroidal leakage could change during a long-term follow-up period. 相似文献
155.
Here we identify a 65 kDa protein (N-WASP) from brain that binds the SH3 domains of Ash/Grb2. The sequence is homologous to Wiskott-Aldrich syndrome protein (WASP). N-WASP has several functional motifs, such as a pleckstrin homology (PH) domain and cofilin-homologous region, through which N-WASP depolymerizes actin filaments. When overexpressed in COS 7 cells, the wild-type N-WASP causes several surface protrusions where N-WASP co-localizes with actin filaments. Epidermal growth factor (EGF) treatment induces the complex formation of EGF receptors and N-WASP, and produces microspikes. On the other hand, two mutants, C38W (a point mutation in the PH domain) and deltaVCA (deletion of the actin binding domain), localize predominantly in the nucleus and do not cause a change in the cytoskeleton, irrespective of EGF treatment. Interestingly, the C38W PH domain binds less effectively to phosphatidylinositol 4,5-bisphosphate (PIP2) than the wild-type PH domain. These results suggest the importance of the PIP2 binding ability of the PH domain and the actin binding for retention in membranes. Collectively, we conclude that N-WASP transmits signals from tyrosine kinases to cause a polarized rearrangement of cortical actin filaments dependent on PIP2. 相似文献
156.
Our analog fuzzy processor features an inference speed of more than 1 million fuzzy logical inferences per second, excluding defuzzification. A rule chip processes fuzzy inferences while a second chip handles defuzzification, a functional division that facilitates flexible system configuration. The chips are compact fuzzy systems that save chip area and are suitable for built-in applications. They process high-speed fuzzy logic operations in parallel mode and, during execution of fuzzy inferences, feature an adaptable fuzzy system based on a rule set 相似文献
157.
A low-complexity pseudo-analog speech transmission scheme is proposed for portable communications. It uses a speech coder based on adaptive differential pulse code modulation (ADPCM) in combination with a multilevel digital modulation technique such as M -ary DPSK or M -ary FSK and features low quantization noise, bandwidth efficiency, and robustness to transmission errors. A nonsymmetric M -ary DPSK scheme called skewed M -ary DPSK is proposed to enhance the noisy channel performance. Comparison to conventional analog FM and a digital speech transmission scheme using adaptive predictive coding and forward error correction (FEC) based on convolutional coding shows that the pseudo-analog system has the best objective signal-to-noise ratio performance under most channel conditions. Informal subjective evaluations rate the digital system superior to the pseudo-analog scheme for bad channels and conversely for good channels. It is concluded that the pseudo-analog system can be designed with low delay and high speech quality for good channels with high spectral efficiency 相似文献
158.
Miki T. 《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》1993,81(11):1594-1609
The key technologies required for the development of optical transport networks, namely, optical fiber transmission and digital transport, which includes transmission signal multiplexing, transport nodes, and network operation functions, are highlighted. The trends in transport technology, the impact of synchronous digital hierarchy (SDH) and asynchronous transfer mode (ATM), the role of telecommunications management networks, and network integrity enhancement techniques are elucidated. It is demonstrated that these technologies have brought about a great change in transport network design and performance. Further innovations are required to fully realize a high-performance computer communication network, a cost-effective nationwide B-ISDN, and local networks for video distribution. These include the realization of an optical access transport network and the extension of trunk network capabilities which will be possible with optical path layer technologies 相似文献
159.
Through laboratory simulation tests and field experiments in the Tokyo metropolitan area, 16 kbit/s Gaussian filtered minimum shift keying (GMSK) transmission performance has been experimentally clarified in the 920 MHz land mobile radio environment. The experimental results agree closely with theory, and they show that fast multipath fading severely degrades average bit error rate (BER) performance in GMSK transmission. However, a space diversity reception technique using a postdetection selection combining scheme is able to efficiently mitigate the fast multipath fading. 相似文献
160.
M Mizuta T Kurose T Miki Y Shoji-Kasai M Takahashi S Seino S Matsukura 《Canadian Metallurgical Quarterly》1997,46(12):2002-2006
Pancreatic beta-cells secrete insulin by Ca2+-triggered exocytosis of insulin-containing large dense-core vesicles. Synaptotagmin is a Ca2+/phospholipid-binding protein and is a good candidate for the Ca2+ sensor for exocytosis of synaptic vesicles in neurons. In the present study, we generated a polyclonal antibody against synaptotagmin III, and found that synaptotagmin III immunoreactivity was present at high levels in insulin-containing pancreatic islet cells and insulin-secreting clonal MIN6 cells. In subcellular fractionations of MIN6 cells, synaptotagmin III was recovered in the vesicular fractions containing both insulin and vesicle-associated membrane protein-2 (VAMP-2), but not in synaptophysin-positive fractions. The secretory vesicles immunoprecipitated by anti-VAMP-2 antibody contained synaptotagmin III and insulin. In addition, treatment of streptolysin-O-permeabilized MIN6 cells with anti-synaptotagmin III antibody significantly inhibited Ca2+-triggered insulin secretion. These results indicate that synaptotagmin III is localized in insulin-containing dense-core vesicles in pancreatic beta-cells, and further strongly suggest that synaptotagmin III is the Ca2+ sensor in the exocytosis of insulin secretory vesicles. 相似文献