74 research outputs found

    Intranasal Immunization with Recombinant HA and Mast Cell Activator C48/80 Elicits Protective Immunity against 2009 Pandemic H1N1 Influenza in Mice

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    Pandemic influenza represents a major threat to global health. Vaccination is the most economic and effective strategy to control influenza pandemic. Conventional vaccine approach, despite being effective, has a number of major deficiencies including limited range of protection, total dependence on embryonated eggs for production, and time consuming for vaccine production. There is an urgent need to develop novel vaccine strategies to overcome these deficiencies.The major objective of this work was to develop a novel vaccine strategy combining recombinant haemagglutinin (HA) protein and a master cell (MC) activator C48/80 for intranasal immunization. We demonstrated in BALB/c mice that MC activator C48/80 had strong adjuvant activity when co-administered with recombinant HA protein intranasally. Vaccination with C48/80 significantly increased the serum IgG and mucosal surface IgA antibody responses against HA protein. Such increases correlated with stronger and durable neutralizing antibody activities, offering protection to vaccinated animals from disease progression after challenge with lethal dose of A/California/04/2009 live virus. Furthermore, protected animals demonstrated significant reduction in lung virus titers, minimal structural alteration in lung tissues as well as higher and balanced production of Th1 and Th2 cytokines in the stimulated splenocytes when compared to those without C48/80.The present study demonstrates that the novel vaccine approach of combining recombinant HA and mucosal adjuvant C48/80 is safe and effective in eliciting protective immunity in mice. Future studies on the mechanism of action of C48/80 and potential combination with other vaccine strategies such as prime and boost approach may help to induce even more potent and broad immune responses against viruses from various clades

    Rapid Turnover of 2-LTR HIV-1 DNA during Early Stage of Highly Active Antiretroviral Therapy

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    BACKGROUND: Despite prolonged treatment with highly active antiretroviral therapy (HAART), the infectious HIV-1 continues to replicate and resides latently in the resting memory CD4+ T lymphocytes, which blocks the eradication of HIV-1. The viral persistence of HIV-1 is mainly caused by its proviral DNA being either linear nonintegrated, circular nonintegrated, or integrated. Previous reports have largely focused on the dynamics of HIV-1 DNA from the samples collected with relatively long time intervals during the process of disease and HAART treatment, which may have missed the intricate changes during the intervals in early treatment. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we investigated the dynamics of HIV-1 DNA in patients during the early phase of HARRT treatment. Using optimized real time PCR, we observed significant changes in 2-LTR during the first 12-week of treatment, while total and integrated HIV-1 DNA remained stable. The doubling time and half-life of 2-LTR were not correlated with the baseline and the rate of changes in plasma viral load and various CD4+ T-cell populations. Longitudinal analyses on 2-LTR sequences and plasma lipopolysaccharide (LPS) levels did not reveal any significant changes in the same treatment period. CONCLUSIONS/SIGNIFICANCE: Our study revealed the rapid changes in 2-LTR concentration in a relatively large number of patients during the early HAART treatment. The rapid changes indicate the rapid infusion and clearance of cells bearing 2-LTR in the peripheral blood. Those changes are not expected to be caused by the blocking of viral integration, as our study did not include the integrase inhibitor raltegravir. Our study helps better understand the dynamics of HIV-DNA and its potential role as a biomarker for the diseases and for the treatment efficacy of HAART

    Multi-Scale Feature Pair Based R-CNN Method for Defect Detection

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    The traditional defect detection algorithms based on image registration, image contrast and other image processing algorithms are only limited to a single defect. Though deep-learning-based object detection algorithms can be used to detect a variety of different defects, the state-of-the-art deep-learning-based object detection algorithms still have low detection accuracy on small size defects. Basing on Cascade R-CNN in this paper, a new multi-scale feature extraction method-the Multi-Scale Feature Pair-is proposed and is used to establish a defect detection model for metal can products of an enterprise. Experimental results show that the accuracy ([email protected]) of our improved model is 6.1% higher than Cascade R-CNN

    Preparation of poly (ethylene glycol) acrylate grafted polystyrene resin for solid-phase peptide synthesis

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    The solid-phasesynthesisresin with high loading capacity was prepared through grafting poly (ethyleneglycol) acrylate monomer from Merrifield resins via activators generated by electron transfer atom transfer radical polymerization. The graftedresins demonstrate well-swellability in both polar and nonpolar solvent such as dichloromethane, dimethylformamide, ethanol, tetrahydrofuran, acetonitrile, methanol and water. Particularly, the swelling ability of the graftedresin has reached two-fold of Merrifield resin in the polar solvent such as acetonitrile, methanol and water, and it enable high functional loadings up to 0.51.2 mmol g(-1) compared with the conventional polystyrene-grafting-poly (ethyleneglycol) (0.150.25 mmol g(-1)). This resin was derived to be used for synthesis of a difficult sequence-acyl carrier protein fragment 65-74 (ACP 65-74). The quantity and purity of peptide obtained from the graftedresin were higher than when the commercial Wang resin was used. The synthesis efficiency enhanced with the increase of grafting chains length within the range of hydroxyl capacity at 0.51.0 mmol g-1. It was relative that the longer grafting chains were favor to suppress the hydrophobicity of the Merrifield resin

    Enhanced inhibition of murine prostatic carcinoma growth by immunization with or administration of viable human umbilical vein endothelial cells and CRM197

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    Vaccination with xenogeneic and syngeneic endothelial cells is effective for inhibiting tumor growth. Nontoxic diphtheria toxin (CRM197), as an immunogen or as a specific inhibitor of heparin-binding EGF-like growth factor, has shown promising antitumor activity. Therefore, immunization with or administration of viable human umbilical vein endothelial cells (HUVECs) combined with CRM197 could have an enhanced antitumor effect. Six-week-old C57BL/6J male mice were vaccinated with viable HUVECs, 1 x 10(6) viable HUVECs combined with 100 μg CRM197, or 100 μg CRM197 alone by ip injections once a week for 4 consecutive weeks. RM-1 cells (5 x 10(5)) were inoculated by sc injection as a preventive procedure. During the therapeutic procedure, 6-week-old male C57BL/6J mice were challenged with 1 x 10(5) RM-1 cells, then injected sc with 1 x 10(6) viable HUVECs, 1 x 10(6) viable HUVECs + 100 μg CRM197, and 100 μg CRM197 alone twice a week for 4 consecutive weeks. Tumor volume and life span were monitored. We also investigated the effects of immunization with HUVECs on the aortic arch wall and on wound healing. Vaccination with or administration of viable HUVECs+CRM197 enhanced the inhibition of RM-1 prostatic carcinoma by 24 and 29%, respectively, and prolonged the life span for 3 and 4 days, respectively, compared with those of only vaccination or administration with viable HUVECs of tumor-bearing C57BL/6J mice. Furthermore, HUVEC immunization caused some damage to the aortic arch wall but did not have remarkable effects on the rate of wound healing; the wounds healed in approximately 13 days. Treatment with CRM197 in combination with viable HUVECs resulted in a marked enhancement of the antitumor effect in the preventive or therapeutic treatment for prostatic carcinoma in vivo, suggesting a novel combination for anti-cancer therapy

    Effects of the Microbubble Generation Mode on Hydrodynamic Parameters in Gas–Liquid Bubble Columns

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    The hydrodynamics parameters of microbubbles in a bubble column were studied in an air–water system with a range of superficial gas velocity from 0.013 to 0.100 m/s using a differential pressure transmitter, double probe optical fiber probe, and electrical resistance tomography (ERT) technique. Two kinds of microbubble generators (foam gun, sintered plate) were used to generate microbubbles in the bubble column with a diameter of 90 mm, and to compare the effects of different foaming methods on the hydrodynamics parameters in the bubble column. The hydrodynamic behavior of the homogeneous regime and the transition regime was also studied. The results show that, by changing the microbubble-generating device, the hydrodynamic parameters in the column are changed, and both microbubble-generating devices can obtain a higher gas holdup and a narrower chord length distribution. When the foam gun is used as the gas distributor, a higher gas holdup and a narrower average bubble chord length can be obtained than when the sintered plate is used as the gas distributor. In addition, under different operating conditions, the relative frequency distribution of the chord length at different radial positions is mainly concentrated in the interval of 0–5 mm, and it is the highest in the center of the column

    Detailed exploration of structure formation of an epoxy-based monolith with three-dimensional bicontinuous structure

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    To explore a clear formation mechanism of a three-dimensional (3D) bicontinuous skeleton and control the structure of an epoxy-based monolith, we have prepared the monolith using a mixture of good and poor solvents. The influences of reaction and phase separation parameters, such as molecular weights and content of porogenic poor solvents, porogenic good solvent concentration, equivalent ratio of epoxy group to amine and reaction temperature on the final morphology are systematically studied by monitoring the reaction process with differential scanning calorimetry (DSC) and observing the cloud points (CP). Depending on the above parameters, the resultant morphology can be varied ranging from closed pore structure to globules aggregated structure, which was controlled by the competitive kinetics between the domain coarsening and the structure freezing. The optimized monoliths with uniform and controllable pores have great potential for application in chromatographic separation, membrane filters, and membrane emulsification.</p

    An environmentally friendly acylation reaction of 2-methylnaphthalene in solvent-free condition in a micro-channel reactor

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    An efficient and solvent-free acylation of 2-methylnaphthalene (2-MN) is presented using acid chloride as both the acylating agent and solvent in a micro channel reactor. The effect of the catalyst, reactant ratio, mixing temperature, reaction temperature and reaction time on the product yield and selectivity was investigated. At room temperature with a reaction time of only 15 min, the target product, 2-methyl-6-propionylnaphthalene (2,6-MPN), was obtained in 72.3% yield with 73.8% selectivity, and 2-methyl-6-acetylnaphthalene (2,6-MAN) was obtained in 54.1% yield with 55.4% selectivity. The route of synthesis provides a more environmentally friendly and efficient method to prepare 2,6-MPN with no other toxic solvents and efficient mass transfer and heat transfer

    Protein Expr. Purif.

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    Novel GSH-AP (phenoxyl agarose coated gigaporous polystyrene, Agap-co-PSt) microspheres were successfully prepared by introducing GSH ligand into hydrophilic AP microspheres pre-activated with 1,4-butanediol diglycidyl ether. The gigaporous structure and chromatographic properties of GSH-AP medium were evaluated and compared with commercial GSH Sepharose FF (GSH-FF) medium. The macropores (100-500 nm) of gigaporous PSt microspheres were well maintained after coating with agarose and functionalized with GSH ligand. Hydrodynamic experiments showed that GSH-AP column had less backpressure and plate height than those of GSH-FF column at high flow velocity, which was beneficial for its use in high-speed chromatography. The presence of flow-through pores in GSH-AP microspheres also accelerated the mass transfer rate of biomolecules induced by convective flow, leading to high protein resolution and high dynamic binding capacity (DEC) of glutathione S-transferase (GST) at high flow velocity. High purity of GST and GST-tagged recombinant human interleukin-1 receptor antagonist (rhIL-1RA) were obtained from crude extract with an acceptable recovery yield within 1.5 min at a velocity up to 1400 cm/h. GSH-AP medium is promising for high-speed affinity chromatography for the purification of GST and GST-tagged proteins. (C) 2013 Elsevier Inc. All rights reserved.Novel GSH-AP (phenoxyl agarose coated gigaporous polystyrene, Agap-co-PSt) microspheres were successfully prepared by introducing GSH ligand into hydrophilic AP microspheres pre-activated with 1,4-butanediol diglycidyl ether. The gigaporous structure and chromatographic properties of GSH-AP medium were evaluated and compared with commercial GSH Sepharose FF (GSH-FF) medium. The macropores (100-500 nm) of gigaporous PSt microspheres were well maintained after coating with agarose and functionalized with GSH ligand. Hydrodynamic experiments showed that GSH-AP column had less backpressure and plate height than those of GSH-FF column at high flow velocity, which was beneficial for its use in high-speed chromatography. The presence of flow-through pores in GSH-AP microspheres also accelerated the mass transfer rate of biomolecules induced by convective flow, leading to high protein resolution and high dynamic binding capacity (DEC) of glutathione S-transferase (GST) at high flow velocity. High purity of GST and GST-tagged recombinant human interleukin-1 receptor antagonist (rhIL-1RA) were obtained from crude extract with an acceptable recovery yield within 1.5 min at a velocity up to 1400 cm/h. GSH-AP medium is promising for high-speed affinity chromatography for the purification of GST and GST-tagged proteins. (C) 2013 Elsevier Inc. All rights reserved

    R-PCNN Method to Rapidly Detect Objects on THz Images in Human Body Security Checks

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    Terahertz human body security images have low resolution and a low signal-to-noise ratio. In the traditional method, image segmentation, positioning, and identification are applied to detect objects carried by humans in the THz images. However, it is difficult to satisfy the requirements of detection accuracy and speed with this approach. The current research presents a faster detection framework (R-PCNN) combining the preprocessing and structure optimization of Faster R-CNN. The experiment results show that this method can effectively improve the accuracy and speed of object detection in human body THz images. A detection accuracy of 84.5% can be achieved in dense flow scenes, with an average detection time of less than 20 milliseconds for each image
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