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81.
To ascertain the natural outcome of idiopathic macular holes, we studied 186 eyes with the disorder: stages 1 (48 eyes), 2 (30 eyes), 3 (71 eyes), and 4 (37 eyes), which were followed for over twelve months. In 11 (23%) eyes with stage 1 lesions full-thickness macular hole developed during the follow-up period, and in 12 (25%) eyes visual acuity decreased two or more Snellen lines. Twenty-five (83%) and 21 (70%) eyes with stage 2 lesions, 39 (55%) and 22 (31%) eyes with stage 3 lesions, and 7 (19%) and 5 (14%) eyes with stage 4 lesions had enlarged macular holes and decreased visual acuity during the follow-up, respectively. The present results suggest that different stages of macular holes have different natural outcomes and the treatment should be based on their stages. 相似文献
82.
K Akasaka Y Akiba Y Ishii S Fujiuchi S Osanai H Nakano H Yamashita K Kikuchi 《Canadian Metallurgical Quarterly》1997,35(1):16-21
This study compared ligand densities on antigen-presenting cells (APCs) needed for in vitro restimulation of in vivo primed T cells and for in vitro assessed T cell effector function. Spleen cells of lymphocytic choriomeningitis virus (LCMV)-primed mice were restimulated in vitro with graded amounts of virus-derived peptides using macrophages or a cloned dendritic cell line as APCs. To test for effector function of these cytotoxic T cells, the same APCs pulsed with graded amounts of the peptides were used as target cells in an in vitro 51Cr release assay. The same peptide concentration that rendered an APC restimulatory for primed cytotoxic T lymphocytes (CTLs) also rendered it susceptible for lysis by the same CTLs. In addition, the same peptide concentrations that made macrophages susceptible for CTL-mediated lysis induced proliferative responses in vitro of in vivo primed memory CTLs. Thus, restimulation of in vivo primed T cells--measured by either proliferation or cytotoxic effector function--or sensibilization of target cells for lysis requires similar ligand densities on APCs and is therefore, contrary to expectations, governed by similar overall avidity thresholds. These results have implications for CTL memory. 相似文献
83.
Israel's situation during the Persian Gulf War, which caused shock and put the country in a state of emergency, is described in this article. Radio was the dominant medium of communication. Even as the fighting was going on, many complaints were lodged against mental health professionals, mostly psychologists, who began to appear on the radio in an attempt to help the population cope with the situation. In this article, reality (the frequency of the appearance of experts, their specialties, and the contents of their messages) is contrasted with the fantastic claims made against the professionals. It is suggested that most of the claims were invalid and that the appearances of the professionals were adequate in both quantity and quality. A hypothesis is offered to explain the gap between the claims and the findings. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
84.
H Teraoka H Akiba R Takai T Taneike T Hiraga A Ohga 《Canadian Metallurgical Quarterly》1997,28(2):237-243
Cleavage of tubulin at tryptophan residues yielded several peptides, one of which strongly interacted with aldolase as determined by inhibition of aldolase activity. This peptide was identified as the C-terminal, residues 408-451, of the alpha-subunit of tubulin. Peptides with identical sequences to the C-terminal regions of the alpha- and beta-subunits of tubulin were synthesized to further characterize interactions with glycolytic enzymes. A 43-amino-acid C-terminal peptide from alpha-tubulin (residues 409-451) was found to have binding properties similar to those of native tubulin and was designated the tubulin glycolytic enzyme binding domain (T-GEBD-43mer). 相似文献
85.
J. Linke M. Akiba T. Ando J. P. Coad S. Deschka E. Wallura 《International Journal of Refractory Metals and Hard Materials》1992,11(6):357-365
The plasma facing components in future thermonuclear confinement experiments have to withstand high stationary heat loads during normal operation and severe thermal shocks during off-normal conditions (so-called disruptions). In these transient events on the first wall, energy depositions up to 2 MJ m−2 can occur with pulse durations of the order of 1 ms. To improve the performance of the plasma and to protect it against high-Z impurities from metallic structures, boron carbide coatings have been used successfully in different fusion experiments. Thick coatings of this material have been prepared by plasma spraying, a technique which also offers potential for in-situ repair of damaged coatings inside the torus.
Coatings with thicknesses of several hundred micrometers on different substrates (graphites, carbon fiber composites, stainless steel and refractory metals) have been tested in high heat flux test facilities at heat loads simulating the normal operation and disruption conditions. In addition, a limited number of coated tiles have been installed in fusion relevant tokamak experiments such as TEXTOR, JET or JT-60U. 相似文献
86.
随着大城市网络带宽需求的增加和技术的发展,城域网产品作为一个独立的产品系列已经脱颖而出。本针对NEC公司的产品,对城域网的构成及其应用提出了自己的观点。 相似文献
87.
88.
The charge-integration readout circuit was fabricated to achieve an ultralow-noise preamplifier for photoelectrons generated in an avalanche photodiode with linear mode operation at 77 K. To reduce the various kinds of noise, the capacitive transimpedance amplifier was used and consisted of low-capacitance circuit elements that were cooled with liquid nitrogen. As a result, the readout noise is equal to 3.0 electrons averaged for a period of 40 ms. We discuss the requirements for avalanche photodiodes to achieve photon-number-resolving detectors below this noise level. 相似文献
89.
Shinobu Yoshimura Kei Kobayashi Hiroshi Akiba Satoru Suzuki Masao Ogino 《Journal of Nuclear Science and Technology》2013,50(4):546-567
This paper presents the three-dimensional finite element seismic response analysis of full-scale boiling water reactor BWR5 at Kashiwazaki-Kariwa Nuclear Power Station subjected to the Niigata-ken Chuetsu-Oki earthquake that occurred on 16 July 2007. During the earthquake, the automatic shutdown system of the reactors was activated successfully. Although the monitored seismic acceleration significantly exceeded the design level, it was found that there were no significant damages of the reactor cores or other important systems, structures and components through in-depth investigation. In the seismic design commonly used in Japan, a lumped mass model is employed to evaluate the seismic response of structures and components. Although the lumped mass model has worked well so far for a seismic proof design, it is still needed to develop more precise methods for the visual understanding of response behaviors. In the present study, we propose the three-dimensional finite element seismic response analysis of the full-scale and precise BWR model in order to directly visualize its dynamic behaviors. Through the comparison between both analysis results, we discuss the characteristics of both models. The stress values were also found to be generally under the design value. 相似文献
90.
The option to use the beam down optics of a solar tower system for large-scale and grid-connected concentrated photovoltaic (PV) cells is examined. The rationale is to use this system to split the solar spectrum. Part of the spectrum can be utilized for PV cells. For instance, but not limited to, mono-crystalline silicon cells can convert the 600–900 nm band to electricity at an efficiency of 55–60%. The rest of the spectrum remains concentrated and it can be used thermally to generate electricity in Rankine–Brayton cycles or to operate chemical processes. Two optical approaches for a large-scale system are described and analyzed. In the first concept, the hyperboloid-shaped tower reflector is used as the spectrum splitter. Its mirrors can be made of transparent fused silica glass, coated with a dielectric layer, functioning as a band-pass filter. The transmitted band reaches the upper focal zone, where an array of PV modules is placed. The location of these modules and their interconnections depend on the desirable concentration level and the uniformity of the flux distribution. The reflected band is directed to the second focal zone near the ground, where a compound parabolic concentrator is required to recover and enhance the concentration to a level depending on the operating temperature at this target. In the second approach, the total solar spectrum is reflected down by the tower reflector. Before reaching the lower focal plane, the spectrum is split and filtered. One band can be reflected and directed horizontally to a PV array and, in this case, the rest of the spectrum is transmitted to the lower focal plane. To illustrate the feasibility of these options, commercial silicon cells with antireflective coating, intended to operate under concentrated solar radiation in the range of 200–800 suns, were chosen. The results show that 6.5 MWe from the PV array and 11.1 MWe from a combined cycle can be generated starting from a solar heat input of 55.6 MW. 相似文献