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91.
The MRP gene contributes to one form of multidrug resistance. To identify drugs interacting with MRP, we measured MRP mRNA expression by quantitative PCR in 60 cell lines of the National Cancer Institute Anticancer Drug Screen. Expression was detected in all cell lines (highest in lung carcinomas and central nervous system tumors) with a range of 14-fold. A mean graph of MRP mRNA levels was constructed to determine Pearson correlation coefficients (PCCs) with mean graphs of >40,000 compounds using the COMPARE analysis. Only 20 compounds had PCCs of >/=0.500. The PCCs for VP-16, doxorubicin, and vincristine were 0.008, 0.13, and 0.257, respectively. Initially, 36 compounds with PCCs of >/=0.428 were analyzed using two MRP-overexpressing cell lines; low levels of cross-resistance was demonstrated for 23 compounds (1.3-9.4-fold). Twenty-four compounds also were available for further studies. Using a fluorescence activated cell sorter assay to measure competition of calcein efflux from MRP-overexpressing cells, 10 compounds were found to increase calcein retention by >/=2-fold. Ten compounds also were able to reduce ATP-dependent [3H]LTC4 transport into vesicles from MRP-overexpressing cells. These results contrast with previous studies with MDR-1 in which high correlations were found and confirmed for a large number of compounds. Although other assays may be more revealing, in these unselected cell lines, MRP mRNA expression was a poor predictor of drug sensitivity. This raises the possibility that other factors, including conjugating enzymes, glutathione levels, or other transporters, confound the MRP effect.  相似文献   
92.
Early in development, murine B-lineage progenitor cells express two classes of IgG Fc receptors (FcgammaR) designated as FcgammaRII (CD32) and FcgammaRIII (CD16), but mature B lymphocytes only express FcgammaRII (CD32), which functions as an inhibitor of B-cell activation when it is induced to associate with mIgM. The functions of CD16 and CD32 on B-lineage precursor cells have not previously been investigated. To search for FcgammaR functions on developing B-lineage cells, normal murine bone marrow cells were cultured in the presence of 2.4G2, a rat monoclonal antibody that binds to CD16 and CD32, or in the presence of control normal rat IgG, and then the B-lineage compartment was analyzed for effects. Cultures that contained 2.4G2 showed enhanced growth and differentiation of B-lineage cells compared with control cultures. The enhancing effect of 2.4G2 also occurred when fluorescence-activated cell-sorted B-cell precursors (B220(+), sIgM-, HSAhigh, FcgammaR+) from normal bone marrow were cocultured with BMS2, a bone marrow stromal cell line, but not when they were cultured in BMS2-conditioned media. The enhancement of B-lineage development induced by 2.4G2 was CD16-dependent and CD32-dependent, because 2.4G2 did not effect B-lineage growth or differentiation in cultures of bone marrow from mice in which either the gene encoding CD16 or CD32 had been disrupted. Analysis of fresh bone marrow from the CD16 gene-disrupted mice showed normal numbers and distribution of cells within the B-cell compartment, but in CD32 gene-disrupted mice, the B-cell compartment was significantly enlarged. These experiments provide several lines of evidence that the FcgammaR expressed on murine B-cell precursors can influence their growth and differentiation.  相似文献   
93.
Virtual objects can be visualized inside real objects using augmented reality (AR). This visualization is called AR X-ray because it gives the impression of seeing through the real object. In standard AR, virtual information is overlaid on top of the real world. To position a virtual object inside an object, AR X-ray requires partially occluding the virtual object with visually important regions of the real object. In effect, the virtual object becomes less legible compared to when it is completely unoccluded. Legibility is an important consideration for various applications of AR X-ray. In this research, we explored legibility in two implementations of AR X-ray, namely, edge-based and saliency-based. In our first experiment, we explored on the tolerable amounts of occlusion to comfortably distinguish small virtual objects. In our second experiment, we compared edge-based and saliency-based AR X-ray methods when visualizing virtual objects inside various real objects. Moreover, we benchmarked the legibility of these two methods against alpha blending. From our experiments, we observed that users have varied preferences for proper amounts of occlusion cues for both methods. The partial occlusions generated by the edge-based and saliency-based methods need to be adjusted depending on the lighting condition and the texture complexity of the occluding object. In most cases, users identify objects faster with saliency-based AR X-ray than with edge-based AR X-ray. Insights from this research can be directly applied to the development of AR X-ray applications.  相似文献   
94.
This paper focuses on the present and near-future possibilities and technologies for wearable augmented reality. The paper provides an overview of the concept of wearable augmented reality and describes a current state-of-the-art system Tinmith. A number of benefits are presented, such as in situ information presentation, hands-free operation, ability to multitask, and navigation aids. The following five major application domains are examined as a means of highlighting the effectiveness of this technology: consumer help, entertainment, manufacturing, medicine, and navigation. The article provides some insights into technological hurdles yet to be overcome.  相似文献   
95.
Der S  Chan A  Nasrabadi N  Kwon H 《Applied optics》2004,43(2):333-348
We describe an algorithm for the detection and clutter rejection of military vehicles in forward-looking infrared (FLIR) imagery. The detection algorithm is designed to be a prescreener that selects regions for further analysis and uses a spatial anomaly approach that looks for target-sized regions of the image that differ in texture, brightness, edge strength, or other spatial characteristics. The features are linearly combined to form a confidence image that is thresholded to find likely target locations. The clutter rejection portion uses target-specific information extracted from training samples to reduce the false alarms of the detector. The outputs of the clutter rejecter and detector are combined by a higher-level evidence integrator to improve performance over simple concatenation of the detector and clutter rejecter. The algorithm has been applied to a large number of FLIR imagery sets, and some of these results are presented here.  相似文献   
96.
(1) The failure of ;Slow-K' tablets to disintegrate prevents rapid release but allows them to be trapped by their bulk in the intestine.(2) Two cases are reported. In the first the tablet was trapped in a caecal diverticulum and the patient developed an abcess. In the second, abdominal pain developed which subsided when ;Slow-K' was stopped. Later ;Slow-K' was again started and the patient developed dysphagia.(3) The possibility of abdominal complications with this treatment should be remembered.(4) Effervescent KC1 preparations may replace ;Slow-K' but KC1 supplementation may be necessary only in cardiac disease.  相似文献   
97.
    
The scope of this paper is to present the proof-of-concept and functional verification of a Wireless-SpaceWire bridge (High-Throughput Wireless-SpaceWire Bridge for Intra-Satellite Transmissions [HiSAT] bridge) designed to replace the wired SpaceWire (SpW) connections for intraspacecraft communications. To provide proper data handling and conversion, the proposed solution implements two main components: (1) the SpW Converter, which provides the SpW interface, and (2) the Wireless Converter, which provides the multiantenna radio frequency (RF) front-end. High-end research infrastructure is used in the solution implementation. STAR-Dundee SpW products emulate real spacecraft instrumentation and implement the SpW links and interfaces. Xilinx FPGA ZCU102 boards are used for the implementation of the hardware/software communication stack of the SpW Converter. A comprehensive National Instruments USRP Software Defined Radio platform is used to implement the Wireless Converter. End-to-end laboratory tests are run to evaluate the performance of the proposed solution in terms of average end-to-end delay, average data rate, and packet success rate and to assess the technology readiness. The results demonstrate that the HiSAT bridge is TRL4 and that the technological approach (i.e., using FPGAs and OFDM transmissions) can successfully replace an on-board intraspacecraft SpW link.  相似文献   
98.
    
There have been an increasing number of materials developed that show multifunctional chromogenic properties (such as electrochromism, electrofluorochromism, or photochromism), but to date, few materials have shown all three properties. Materials that are electrochemically and optically active are attractive for a diverse set of applications that include smart-windows, lighting, sensing, energy production, and conservation. This is especially attractive for building developers interested in adaptive or environmentally responsive façades. Achieving systems made from cost-effective, readily synthesized materials will make them easy to utilize in a variety of fields. Low-cost devices are developed using water-soluble, chromogenic thiazolo(5,4-d)thiazole (TTz) dyes that show high device performance in three areas: electrochromism, electrofluorochromism, and photochromism and are all contained within a highly fluorescent aqueous polyvinyl alcohol/borax hydrogel device. The dyes incorporate a rigid, heterocyclic TTz structure that enables the development of devices with excellent reversibility and stable cycling for 250 cycles. The TTz hydrogel-containing devices also exhibit photochromism under illumination, which can be electrochemically cycled back to the colorless state. In addition, coupling photochromism with electrochromism lowers the power necessary for a comparable electrochromic color change. Last, the hydrogel-containing devices also show electrofluorochromism, where fluorescence can be turned off by > 90%.  相似文献   
99.
We have proposed a new explanation for the photo-induced volume changes in chalcogenide glasses. We have found that the covalent bond breaking occurs in these glasses with excited electrons, whereas holes contribute to the formation of inter-chain bonds. We have calculated the charge distribution in a-Se, too.  相似文献   
100.
PVC has a significant tendency to degrade under γ irradiation. Therefore, considerable efforts have been made to improve its γ-radiation stability. The purpose of this review is to summarize recent results in this area, with a special emphasis on the improvement of color stability of PVC-based materials used in medical applications.  相似文献   
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