Gradient-index rod lens with a high acceptance angle for color use by Na(+) for Li(+) exchange

The relationship between the characteristics of gradient-index rod lenses obtained by ion exchange and their mother glass compositions is studied. It is observed that Li(2)O content, R(2)O (Li(2)O + Na(2)O) content, and the Li(2)O/Na(2)O ratio are important factors in attaining a high acceptance angle and a small field curvature. Thus the gradient-index lens array is fabricated by the use of a newly developed glass composition and its optical performance; the modulation transfer function, luminous intensity, and chromatic aberration are precisely evaluated. The array is found to have a sufficiently high performance to be applicable for color use.     

Heparan sulfate proteoglycan on endothelium efficiently induces integrin-mediated T cell adhesion by immobilizing chemokines in patients with rheumatoid synovitis

OBJECTIVE: To clarify the role of heparan sulfate proteoglycan (HSPG) and chemokines in integrin-mediated T cell adhesion to endothelial cells in the synovium of patients with rheumatoid arthritis (RA). METHODS: Endothelial cells were purified from RA synovium. Expression of heparan sulfate, chemokines, and adhesion molecules on the endothelium was assessed by immunohistochemical analysis or flow cytometry. The effects of chemokines and heparan sulfate on T cell adhesion to RA endothelium were estimated with relevant antibodies and signaling inhibitors. Production of chemokines from synovial T cells was detected by Northern blotting and enzyme-linked immunosorbent assay. RESULTS: The endothelium in RA synovium highly expressed HSPG. The soluble form of chemokines, macrophage inflammatory protein 1beta (MIP-1beta), induced T cell adhesion to the endothelial cells. When MIP-lalpha and MIP-1beta were immobilized on RA endothelial cells, a more efficient integrin-mediated adhesion of T cells was induced compared with their soluble form. The induced T cell adhesion was reduced by pretreatment with either heparitinase, anti-MIP-lalpha antibody, or anti-MIP-lbeta antibody, indicating that these chemokines were bound to heparan sulfate on the cells. T cell adhesion was also inhibited by pertussis toxin, wortmannin, and cytochalasin B. MIP-lalpha and MIP-1beta were found on vessels in RA synovium in vivo, which were spontaneously produced from T cells purified from RA synovium. CONCLUSION: Endothelial cells in RA synovium characteristically express HSPG, which is involved in T cell integrin triggering by "posting" chemokines, which are produced by synovial T cells, and by "relaying" them to their receptors on T cells, which activate G protein-dependent phosphoinositide 3-kinase and actin-dependent integrin triggering.     

Quantitative determination of cardiac glycosides in Digitalis lanata leaves by reversed-phase thin-layer chromatography

We have recently chosen to undertake a comprehensive evaluation of the modulation of gene expression by oxidative stress, using mRNA as a marker. Our model system is HA-1 hamster fibroblasts, using conditions under which we observe an adaptive response. Under these conditions, the HA-1 cells respond to a minimally toxic "pretreatment" dose of hydrogen peroxide by synthesizing RNAs and proteins that protect them against subsequent exposure to a highly cytotoxic concentration of hydrogen peroxide. Using the differential display technique to screen for modulated RNAs, we have recently reported an RNA species, adapt15/gadd7, whose steady-state level is significantly induced by a pretreatment dose of hydrogen peroxide (D. R. Crawford, G. P. Schools, S. L. Salmon, and K. J. A. Davies (1996) Arch. Biochem. Biophys. 325, 256-264). Here we report a second induced mRNA, designated adapt33. Two homologous adapt33 mRNAs were revealed by Northern blot hybridization. Both of these species were inducible by hydrogen peroxide, and they were sized at 1.46 and 0.99 kb. These inductions appeared to be dependent upon calcium, occurred as early as 90 min, and were maximal at 5 h. Cell fractionation revealed that a significant proportion of adapt33 RNA is associated with active translation. adapt33 is a novel sequence, as determined by cloning, sequencing, and GenBank analysis. adapt33 represents a new oxidant-inducible RNA and marker of cellular oxidative stress and a potential aid in the study, detection, and possible therapy of oxidant-related disorders.     

Designing high-level decision making systems based on fuzzy if–then rules for a point-to-point car racing game

In this paper, fuzzy rule-based systems are applied to a point-to-point car racing game. In the point-to-point car racing game, two car agents compete with each other for taking waypoints. There are three waypoints in the car racing field, each of which is assigned a number that indicates the order to take. The control process of car agents is modeled as a non-holonomic system where there are two input variables (acceleration and steering) for controlling the position, angle and velocity of the car agents. Fuzzy rule-based systems are used to make a high-level decision where the target waypoint to take is determined. Since a fuzzy rule-based system for the high-level decision making is generated in the manner of supervised learning, a set of training patterns should be given for the construction of the fuzzy rule-based systems. In this paper we examine two methods to obtain such a set of training patterns. We also examine two representations of input vectors for the fuzzy rule-based systems. We discuss the effect of obtained training patterns and the input representation on the performance of the fuzzy rule-based systems. After discussing and analyzing the experimental results, we present an adaptive framework of fuzzy rule-based systems. The performance of adaptive fuzzy rule-based systems is then examined based on the results of their non-adaptive version. A series of computational experiments are performed to show the learning ability of the adaptive fuzzy rule-based systems.     

Japanese/English Cross-Language Information Retrieval: Exploration of Query Translation and Transliteration

Cross-language information retrieval (CLIR), where queriesand documents are in different languages, has of late become one ofthe major topics within the information retrieval community. Thispaper proposes a Japanese/English CLIR system, where we combine aquery translation and retrieval modules. We currently target theretrieval of technical documents, and therefore the performance of oursystem is highly dependent on the quality of the translation oftechnical terms. However, the technical term translation is stillproblematic in that technical terms are often compound words, and thusnew terms are progressively created by combining existing basewords. In addition, Japanese often represents loanwords based on itsspecial phonogram. Consequently, existing dictionaries find itdifficult to achieve sufficient coverage. To counter the firstproblem, we produce a Japanese/English dictionary for base words, andtranslate compound words on a word-by-word basis. We also use aprobabilistic method to resolve translation ambiguity. For the secondproblem, we use a transliteration method, which corresponds wordsunlisted in the base word dictionary to their phonetic equivalents inthe target language. We evaluate our system using a test collectionfor CLIR, and show that both the compound word translation andtransliteration methods improve the system performance.     

A novel chromatographic separation technique using tertiary pyridine resin for the partitioning of trivalent actinides and lanthanides

A novel chromatographic separation technique using a tertiary pyridine type resin has been applied to the partitioning of the trivalent actinides (An) and lanthanides (Ln) and several successful results have been shown. In an alcoholic hydrochloric acid system, the trivalent An were clearly separated from the Ln, while no such group separation was achieved in an alcoholic nitric acid system. On the other hand, the nitric acid system was more effective for the intragroup (i.e. individual) separation of the trivalent An and the Ln than the hydrochloric acid system. On the basis of these results, a novel concept for the partitioning of the trivalent An and Ln using the present separation technique and its flowchart have been proposed with its advantages and disadvantages.     

SCARA型机械手的鲁棒防振控制

对ＳＣＡＲＡ型机械手的防振控制进行研究，提出了两自由度鲁棒控制法，应用μ控制理论设计鲁棒反馈控制器，保证了系统的鲁棒稳定性及鲁棒性能指标；基于模型匹配法设计前馈控制器，组成两自由度控制系统，进一步改善了闭环系统的跟踪特性。仿真研究表明，与传统的ＰＤ控制相比，该控制系统能对机械手前端的残留振支进行有效的抑制，取得较好的轨迹跟踪特性。     

Narrow-beam divergence 1.3-μm multiple-quantum-well laser diodeswith monolithically integrated tapered thickness waveguide

This paper describes the optimum design, fabrication, and performance of a 1.3-μm multiple-quantum-well (MQW) laser diode monolithically integrated with a tapered thickness spot-size transformer. The dependence of the lasing characteristics on the thickness distribution of the core layer and on the current injection profile of the device were analyzed. This integrated laser with its optimized structure performed at a low threshold current of 22.2 mA, even at 85°C. The integrated spot-size transformer effectively reduced the lateral and vertical far-field FWHM's to 8° and 9°, respectively. A very long lifetime of over 1×10⁵ h was estimated at 85°C and 8 mW under CW operation     

Effect of atomic oxygen exposure on bubble formation in aluminum alloy

In order to investigate the effect of atomic oxygen exposure of an aluminum alloy on bubble formation during welding, electron beam welding was performed on the samples exposed to atomic oxygen produced by the oxygen plasma method. The change in the aluminum surface due to the exposure was analyzed by auger electron spectroscopy. Due to the exposure of atomic oxygen, the thickness of the aluminum oxide film increases on the surface, and pores are formed during welding. The pores can be formed by the formation of the Al₂O gas through the reaction between the aluminum oxide and aluminum in a high vacuum.