278 research outputs found

    A Multi-Criteria Group Decision-Making Method with Possibility Degree and Power Aggregation Operators of Single Trapezoidal Neutrosophic Numbers

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    Single valued trapezoidal neutrosophic numbers (SVTNNs) are very useful tools for describing complex information, because of their advantage in describing the information completely, accurately and comprehensively for decision-making problems. In the paper, a method based on SVTNNs is proposed for dealing with multi-criteria group decision-making (MCGDM) problems. Firstly, the new operations SVTNNs are developed for avoiding evaluation information aggregation loss and distortion

    Investigation of folate-conjugated fluorescent silica nanoparticles for targeting delivery to folate receptor-positive tumors and their internalization mechanism

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    Multifunctionalized nanoparticles (NPs) are emerging as ideal tools for gene/drug delivery, bioimaging, labeling, or intracellular tracking in biomedical applications, and have attracted considerable attention owing to their unique advantages. In this study, fluorescent silica NPs were synthesized by a modified Stöber method using conjugates of 3-mercaptopropyltrimethoxysilane (MPS) and maleimide-fluorescein isothiocyanate (maleimide-FITC). Mean diameters of the NPs were controlled between 212–2111 nm by regulating MPS concentration in the reaction mixture. Maleimide-FITC molecules were doped into NPs or conjugated to the surface of NPs through the chemical reaction of maleimide and thiol groups. The data showed that the former NPs are better than the latter by comparing their fluorescence intensity. Furthermore, folate molecules were linked to the FITC-doped silica NPs by using polyethylene glycol (PEG) (NH2-PEG-maleimide) as a spacer, thus forming folate receptor targeting fluorescent NPs, referred to as NPs(FITC)-PEG-Folate. The quantitative analysis of cellular internalization into different cancer cells showed that the delivery efficiency of KB cells (folate receptor-positive cells) is more than six-fold higher than that of A549 cells (folate receptor-negative cells). The delivery efficiency of KB cells decreased significantly after free folate addition to the cell culture medium because the folate receptors were occupied by the free folate. The NPs endocytosis mechanism was also investigated. It was shown that clathrin, an inhibitor of cell phagocytosis, markedly decreased the NPs uptake into KB cells, suggesting that it plays an important role in NPs cellular internalization. These results demonstrated that the novel particles of NPs(FITC)-PEG-Folate are promising for fluorescent imaging or targeting delivery to folate receptor-positive tumors

    The Design of High Performance, High Resolution Two-Order Delta-Sigma Modulator

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    The design of single loop two-order Delta-Sigma modulator with feed forward structure is presented in this thesis. Oversampled analog-to-digital converters based on second-order delta-sigma modulation are attractive for VLSI implementation because they are especially tolerant of circuit nonidealities and component mismatch. The noise shaping and oversampling are used in this modulator, the oversampling rate (OSR) is 256 and the resolution could be reached 14 bits. The integrally design of Delta-Sigma modulator is argued in deep in the paper, since the behavior model is tested efficiently by Simulink, the time of design has been cut to the bone. As the fully differential structure is used, the system to inhibit the ability of common-mode interference improved and the sampling rate is also raised, the fully differential switching capacity structure is used in the circuit design of modulator. And because of the fully differential structure, the input noise is reduced, the output slewrate of op-amp is greatly improved and the whole circuit is more stable. The 0.5 ?m CMOS process is used in simulation of circuit, the results of simulation are shown that the amplifier gain is 82.3 dB, the Phase Margin is 71.34°, the output slewrate of op-amp is 202 V/?s, the unit GainBandWidth is 102 MHz. the whole circuit of modulator is tested with 10.24 MHz of the clock frequency, the SNDR reached to 93.2 dB, the Dynamic Range (DR) is 100 dB. In summary, this Delta-Sigma modulator could be used in Portable, Audio system and so on

    Scaffold Structural Microenvironmental Cues to Guide Tissue Regeneration in Bone Tissue Applications

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    In the process of bone regeneration, new bone formation is largely affected by physico-chemical cues in the surrounding microenvironment. Tissue cells reside in a complex scaffold physiological microenvironment. The scaffold should provide certain circumstance full of structural cues to enhance multipotent mesenchymal stem cell (MSC) differentiation, osteoblast growth, extracellular matrix (ECM) deposition, and subsequent new bone formation. This article reviewed advances in fabrication technology that enable the creation of biomaterials with well-defined pore structure and surface topography, which can be sensed by host tissue cells (esp., stem cells) and subsequently determine cell fates during differentiation. Three important cues, including scaffold pore structure (i.e., porosity and pore size), grain size, and surface topography were studied. These findings improve our understanding of how the mechanism scaffold microenvironmental cues guide bone tissue regeneration

    Immunohistochemical localization of mu opioid receptor in the marginal division with comparison to patches in the neostriatum of the rat brain

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    <p>Abstract</p> <p>Background</p> <p>Mu opioid receptor (MOR), which plays key roles in analgesia and also has effects on learning and memory, was reported to distribute abundantly in the patches of the neostriatum. The marginal division (MrD) of the neostriatum, which located at the caudomedial border of the neostriatum, was found to stain for enkephalin and substance P immunoreactivities and this region was found to be involved in learning and memory in our previous study. However, whether MOR also exists in the MrD has not yet been determined.</p> <p>Methods</p> <p>In this study, we used western blot analysis and immunoperoxidase histochemical methods with glucose oxidase-DAB-nickel staining to investigate the expression of MOR in the MrD by comparison to the patches in the neostriatum.</p> <p>Results</p> <p>The results from western blot analyses revealed that the antibody to MOR detected a 53 kDa protein band, which corresponded directly to the molecular weight of MOR. Immunohistochemical results showed that punctate MOR-immunoreacted fibers were observed in the "patch" areas in the rostrodorsal part of the neostriatum but these previous studies showed neither labelled neuronal cell bodies, nor were they shown in the caudal part of the neostriatum. Dorsoventrally oriented dark MOR-immunoreactive nerve fibers with individual labelled fusiform cell bodies were firstly observed in the band at the caudomedial border, the MrD, of the neostriatum. The location of the MOR-immunoreactivity was in the caudomedial border of the neostriatum. The morphology of the labelled fusiform neuronal somatas and the dorsoventrally oriented MOR-immunoreacted fibers in the MrD was distinct from the punctate MOR-immunoreactive diffuse mosaic-patterned patches in the neostriatum.</p> <p>Conclusions</p> <p>The results indicated that MOR was expressed in the MrD as well as in patches in the neostriatum of the rat brain, but with different morphological characteristics. The punctate MOR-immunoreactive and diffuse mosaic-patterned patches were located in the rostrodorsal part of the neostriatum. By contrast, in the MrD, the dorsoventrally parallel oriented MOR-immunoreactive fibers with individual labelled fusiform neuronal somatas were densely packed in the caudomedial border of the neostriatum. The morphological difference in MOR immunoreactivity between the MrD and the patches indicated potential functional differences between them. The MOR most likely plays a role in learning and memory associated functions of the MrD.</p
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