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101.
The mucin MUC1 is overexpressed and aberrantly glycosylated by many epithelial cancer cells manifested by truncated O‐linked saccharides. Although tumor‐associated MUC1 has generated considerable attention because of its potential for the development of a therapeutic cancer vaccine, it has been difficult to design constructs that consistently induce cytotoxic T‐lymphocytes (CTLs) and ADCC‐mediating antibodies specific for the tumor form of MUC1. We have designed, chemically synthesized, and immunologically examined vaccine candidates each composed of a glycopeptide derived from MUC1, a promiscuous Thelper peptide, and a TLR2 (Pam3CysSK4) or TLR9 (CpG‐ODN 1826) agonist. It was found that the Pam3CysSK4‐containing compound elicits more potent antigenic and cellular immune responses, resulting in a therapeutic effect in a mouse model of mammary cancer. It is thus shown, for the first time, that the nature of an inbuilt adjuvant of a tripartite vaccine can significantly impact the quality of immune responses elicited against a tumor‐associated glycopeptide. The unique adjuvant properties of Pam3CysSK4, which can reduce the suppressive function of regulatory T cells and enhance the cytotoxicity of tumor‐specific CTLs, are likely responsible for the superior properties of the vaccine candidate 1 .  相似文献   
102.
Molybdenum‐doped cordierite ceramics have been fabricated through facile combined techniques, coprecipitation followed by solid state. XRD results revealed that α‐cordierite phase is predominated with increasing Mo6+ ion content. The density measurements showed that the bulk density reduced to the minimum value of 0.61 g/cm3, which corresponds to the maximum porosity of about 76.8% at 5% Mo6+ ion. The dielectric permittivity (ε) of pure cordierite is decreased with increasing Mo6+ ion content. The minimum dielectric loss of Mo‐doped cordierite at 1 MHz was equal 0.008 with 10% Mo6+, while at 1 GHz was equal 0.03 with 5% Mo6+.  相似文献   
103.
Construction of low-income housing projects is a recurring process and is associated with uncertainties that arise from the unavailability of resources. This paper presents a case study that discusses how computer simulation and optimisation are used to aid government agencies and/or contractors in planning of such projects. It illustrates the optimisation of project objectives, taking into consideration the interaction amongst involved resources. As such, total duration and the associated total costs, including direct and indirect costs, can be estimated and optimised. One Youth Habitation project that is executed in 6th of October City in Egypt is analysed in a step-by-step procedure to demonstrate the capability of proposed computer simulation and optimisation prototype (named LIHouse{_}Sim) in the modelling construction of low-income housing projects using bearing block walls with hollow core technique. The presented tool proves its practicality to contractors in estimating the time and costs of the recurring process of low-income housing construction, considering complex interdependencies between construction resources and the uncertainties associated with construction activities. The LIHouse{_}Sim prototype is used to perform a wide analysis for the alternative of the effective optimisation criteria in the bearing block walls/hollow core technique and for the genetic algorithm optimisation approach elements.  相似文献   
104.
The efficiency of data transmission over fading channels in orthogonal frequency division multiplexing (OFDM) systems depends on the employed interleaving method. In this study, we propose an improved chaotic interleaving scheme which aims to improve the performance of OFDM system under fading channel. In the proposed scheme, the binary data is interleaved with chaotic Baker map prior to the modulation process. In the sequel, significant degree of encryption is being added during data transmission. The performance of the proposed approach is tested on the conventional fast Fourier transform OFDM, discrete wavelet transform OFDM, and discrete cosine transform OFDM with and without chaotic interleaving. Furthermore, an expectation–maximization (EM) algorithm is proposed for improving channel impulse response (CIR) estimation based on a maximum likelihood principle. The proposed scheme makes use of EM algorithm to update the channel estimates until convergence is reached. The simulation results show the efficiency of the proposed algorithms under Rayleigh fading environments where the symbol error rate essentially coincides with that of the perfect channel case after the fifth EM iteration.  相似文献   
105.
In this paper, we address the problem of cooperation among vehicles in VANET using QoS-OLSR protocol in the presence of selfish nodes. QoS-OLSR is a proactive protocol that considers the Quality of Service (QoS) of the nodes while electing the cluster-heads and selecting the Multi-Point Relay (MPRs) nodes. Cluster-heads and MPRs might misbehave on the roads by over-speeding or under-speeding. Classical and generous Tit-for-Tats are proposed to analyze the interaction among vehicles. However, both strategies are not able to enforce the cooperation due the fact that they (1) count on individual watchdogs monitoring, (2) rely on the node-to-node cooperation decision, (3) and ignore the high mobility and packet collisions. Therefore, we propose a Dempster–Shafer based Tit-for-Tat strategy that is able to improve the decision and regulate the cooperation in the vehicular network. This is done by (1) launching a cooperative watchdogs monitoring, (2) correlating the observations of the different watchdogs using Dempster–Shafer theory, and (3) propagating the decisions among clusters. Thereafter, we compare the Dempster–Shafer based strategy with several strategies derived from the original Tit-for-Tat. Simulation results prove that the Dempster–Shafer based strategy is able to maintain the survivability of the vehicular network in the presence of high mobility and packet collisions with minimal time and overhead.  相似文献   
106.
107.
A novel temperature-dependent model for Yb3+-Er3+-codoped fiber amplifier (EYDFA) based on the energy transfer from Yb3+ to Er3+ is established. Using appropriate fiber and energy transfer parameters, the coupled rate equations is numerically solved at 25 and 40 °C. The pumping powers are 100 and 200 mW at a pump wavelength of 1060 nm. The signal gain and noise characteristics of a 0.3 m erbium/ytterbium co-doped fiber (EYDF) in a single-pass configuration are investigated by using 1, 10 and 100 μW signals at 1535 nm. A maximum signal gain of 40.5 dB and a corresponding noise figure of 3.65 dB at the temperature of 25 °C are achieved.  相似文献   
108.
Oh SS  Ahmad KM  Cho M  Kim S  Xiao Y  Soh HT 《Analytical chemistry》2011,83(17):6883-6889
The generation of nucleic acid aptamers with high affinity typically entails a time-consuming, iterative process of binding, separation, and amplification. It would therefore be beneficial to develop an efficient selection strategy that can generate these high-quality aptamers rapidly, economically, and reproducibly. Toward this goal, we have developed a method that efficiently generates DNA aptamers with slow off-rates. This methodology, called VDC-MSELEX, pairs the volume dilution challenge process with microfluidic separation for magnetic bead-assisted aptamer selection. This method offers improved aptamer selection efficiencies through the application of highly stringent selection conditions: it retrieves a small number (<10(6)) of magnetic beads suspended in a large volume (>50 mL) and concentrates them into a microfluidic chamber (8 μL) with minimal loss for continuous washing. We performed three rounds of the VDC-MSELEX using streptavidin (SA) as the target and obtained new DNA aptamer sequences with low nanomolar affinity that specifically bind to the SA proteins.  相似文献   
109.
BACKGROUND: The etiology of retinal venous occlusion in young patients is not well understood although thrombosis does occur histologically. A search for the risk factors that may lead to thrombosis is highly desirable may contribute to our understanding of the pathogenesis of this complication and may improve our therapeutic strategies. METHODS: We studied 17 patients with retinal venous occlusion. All patients were under 45 years of age (mean 37.8 +/- 7.1). Antiphospholipid antibodies (APAs) and certain hemostatic factors were determined. The results obtained in these patients were compared to those of normal controls. RESULTS: We found APAs in 8 out of 17 patients compared to 5 out of 60 controls (p = 0.0002). In patients with major trunk occlusion, there was a trend for the presence of APAs in those with poor visual acuity at presentation. Deficiencies of the coagulation inhibitor proteins C and S and antithrombin III activities were detected in 6 patients, and reduced levels of Factor XII were found in 4 patients. Levels of hematocrit, erythrocyte sedimentation rate. Fibrinogen, alpha 1-globulin, and alpha 2-globulin were significantly higher in patients compared to the controls (p = 0.019; 0.014; 0.0001; 0.011; 0.047), indicating increased blood viscosity in patients with retinal venous occlusion. CONCLUSION: Prothrombotic changes in the form of APAs and/or deficiencies of coagulation inhibitors and Factor XII may contribute to the etiology of retinal venous occlusion in young adults. Young patients with retinal venous occlusion should be evaluated for these prothrombotic states.  相似文献   
110.
In the present study, the removal and immobilization of 137Cs from aqueous waste solutions and a simulated waste was investigated. Two inorganic ion‐exchange complexes: di‐potassium hexacyanocobalt(II)‐ferrate(II), K2CoFe(CN)xH2O (KCFC), and ammonium‐12‐molybdophosphate [(NH4)3PMo12O40·aq] (AMP), were charged separately into porous nylon bags (sorption bags) of 5 µm pore diameter. The first complex (KCFC) was prepared in our laboratory. The second (AMP) was used for comparison. Easy handling and increased potential for reuse characterize the sorption bag technique. The KCFC complex was investigated by thermal gravimetric analysis (TGA) and differential thermal analysis (DTA), porosity, infra‐red (IR) and X‐ray powder diffraction (XRD). The chemical and structural investigations revealed that the KCFC complex has adequate ion‐exchange capacity and high affinity for 137Cs. The sorption bag technique showed promising results for the removal of 137Cs from aqueous waste solutions. The KCFC bags showed the highest 137Cs removal (~0.91 g g?1), at pH 8.5; AMP bags gave the highest 137Cs removal (~0.97 g g?1) in 0.1 N HNO3 and 1.5 N HNO3, both with a waste: sorbent ratio of 80 cm3 g?1. Sorption data for both KCFC and AMP revealed a good fit to the Freundlich sorption isotherm. To assess the potential of sorption bags, the used bags were regenerated in different leachants and reused in further sorption investigations. 137Cs recovery from the used sorbents was ~0.46 g g?1 using 6 N HCl as leachant for AMP, compared with ~0.253 g g?1 for KCFC using 6 N NaCl. These results indicated stronger cesium immobilization in the KCFC complex. Copyright © 2003 Society of Chemical Industry  相似文献   
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