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51.
Wensen Liu Na Xu Hongyan Yuan Songyan Li Linna Liu Zhaoyang Pu Jiayu Wan Huiwen Wang Yaping Chang Ruisheng Li 《International journal of molecular sciences》2013,14(6):12401-12410
Ricin toxin binding subunit B (RTB) is one of the subunits of the ricin protein. RTB has been used as adjuvant, but little is known about its mechanism. In this study, we found that RTB increased not only nitric oxide (NO) release, but also tumor necrosis factor (TNF)-α and interleukin (IL)-6 production in mouse macrophage cell line RAW264.7 cells. They subsequently exhibited enhanced ConA-induced T-cell and LPS-induced B-cell proliferative responses. We also examined the cytokines that were produced from splenocytes following in vitro RTB administration. Increased levels of IL-2, interferon (IFN)-γ and TNF-α were observed, while IL-4 and IL-5 were unaffected. These results demonstrate that recombinant RTB can act on the immune system and activate T-cells by introducing a Th1 immune response. Th1 cells might be the primary cellular target affected by RTB. Our results suggest that the recombinant RTB can promote the activation of macrophages and has a beneficial effect on immunomodulatory activity. 相似文献
52.
[60]Fullerene (C60) was mono-substituted with well-defined poly(methyl methacrylate) (PMMA-b-C60) using the atom transfer radical polymerization (ATRP) technique. The self-assembly behaviors of PMMA-b-C60 in ethyl acetate (EA) and decalin mixtures were studied using laser light scattering (LLS) and transmission electron microscopy (TEM). Homogeneous solutions of PMMA-b-C60 can be obtained in the solvent mixtures containing more than 40 wt% EA, where the molar ratio of decalin to EA is close to 1. For each solvent mixture, unimers coexist with micelles and large aggregates. The sizes of PMMA-b-C60 micelles and aggregates are independent of polymer concentration, confirming that they are produced via the closed association mechanism. For the various solvent mixtures, the weight-averaged molecular weights, Mw of the PMMA-b-C60 aggregates range from 4.1×107 to 12.5×107 g/mol. The hydrodynamic radii of the large aggregate, Rh, vary from 90 to 136 nm, while the z-averaged radii of gyration, Rg, range from 210 to 311 nm. The Rg/Rh value for each solvent mixture is ∼2.3, which is independent of decalin contents in the mixed solvents. The morphological study using the transmission electron microscope suggests that the large aggregates are composed of porous large compound micelles (LCM) in solution. 相似文献
53.
Analysis of Intestinal Injuries Induced by Ricin in Vitro Using SPR Technology and MS Identification
Linna Liu Hongwei Gao Jiping Li Ying Dong Ning Liu Jiayu Wan Wensen Liu Yucheng Sun Ming Xu 《International journal of molecular sciences》2009,10(5):2431-2439
The present study found that ricin toxicity did not only manifest itself as inhibition of protein synthesis, but also induced apoptosis of immune cells and played an extremely significant role in intestinal injury. In this report, we describe a novel method to estimate binding events occurring on intestinal brush border membranes (BBM) based on SPR technology in an attempt to mimic the real intestinal surface capable of interacting physically and/or actively with certain biological molecules. Combined with HPCE-ESI-MS indentification, we obtained 28 kinds of proteins in BBM that interacted with ricin. 相似文献
54.
The Okinawan folks in Japan use Ficus pumila L. as a beverage or herbal medicine to treat diabetes and high blood pressure. Four flavonoid glycosides were isolated and identified as rutin (1 and 3), apigenin 6-neohesperidose (2), kaempferol 3-robinobioside (4) and kaempferol 3-rutinoside (5). Among these compounds, rutin exhibited the strongest antioxidant activity in DPPH radical scavenging assay and superoxide radical inhibition assay. The preparation of Ooitabi leaves in water provide sufficient amount of flavonoid glycosides to the Okinawan although 50% of aqueous ethanol extracted these flavonoid glycosides more effectively. These results show the potential of Ooitabi leaves as a natural source of antioxidant for health management. 相似文献
55.
Dielectric loss tangent and permittivity of polytetrafluoroethylene (Teflon), high-density (HD) polyethylene, and cross-linked polystyrene (Rexolite) were measured at temperature range from 28 to 84 K and frequency of approximately 18 GHz. The material properties were determined by measurements of the resonant frequency and the Q factor of a TE011 mode cylindrical superconducting cavity containing a sample under test. It has been demonstrated that these materials exhibit very low losses at cryogenic temperatures (2×10-6 for Teflon, 5×10-5 for HD polyethylene and 1.1×10-4 for Rexolite). Due to low losses, these materials can be useful in construction of various high-Q factor microwave devices for operation at cryogenic temperatures 相似文献
56.
为解决由行人姿态、环境等复杂因素导致的行人特征表达能力弱、识别率低等问题,本文通过对AlignedReID++模型进行改进,提出了基于跨纬度交互注意力机制的行人重识别方法.首先,在特征提取部分,将跨纬度交互注意力Triplet At?tention模块嵌入到ResNet50网络中,捕获空间维度和通道维度之间跨纬度的交互... 相似文献
57.
A new transient two-dimensional model with non-constant condensing pressure for a zeolite/water adsorption cooling cycle is proposed in this paper. This numerical model focuses on the heat and mass transfer behaviors in the adsorber and is solved by the control volume method. Due to the heat transfer limitation in the condenser, the simulated pressure during the isobaric generation phase of the cycle is not constant and will decrease with time. Compared with the model for constant condensing pressure, the cycle duration and cycled adsorbate for the base case are increased. Furthermore, the effect of mass flow rate of condenser cooling water on system performance is also investigated. It is found that both COP and SCP increase with an increase in the mass flow rate of cooling water in the condenser. 相似文献
58.
Miyamoto R.Y. Leong K.M.K.H. Seong-Sik Jeon Yuanxun Wang Yongxi Qian Itoh T. 《Vehicular Technology, IEEE Transactions on》2003,52(5):1181-1188
A wireless sensor server is developed based on a reconfigurable active smart-antenna/retrodirective array. The system can serve as both a retrodirective array transponder and a smart-antenna receiver simply by changing the frequency of the local oscillator applied to the mixers, enabling it to utilize its hardware best to suit its communication environment. When operating as a direct-conversion receiver, the receiver array successfully demodulates a quaternary phase-shift keying (QPSK) modulated signal with circuit gain of 7 dB, and E/sub b//N/sub 0/ for BER=10/sup -4/ is approximately 12 dB without any error correction. In the retrodirective array mode, the system provides 20 dB circuit gain and 20 dB radio-frequency/intermediate-frequency isolation at the center frequency as well as phase conjugation, exhibiting excellent retrodirectivity. The mixers perform phase conjugation and modulation simultaneously, enabling the transmission of locally stored data. The local data is successfully extracted by an interrogator. 相似文献
59.
Network-attached storage (NAS) and storage area network (SAN) are the enterprise storage architectures that are commonly deployed in data centers. However, as storage demands escalate over time, none of these storage networks support aggressive concurrency and per-server throughput requirements for the applications on highly scalable computing clusters. In recent times, efforts have been set to incorporate the strengths of existing storage architectures into a unique framework that accomplished the performance, scalability, manageability, and a high level of data security. The approach has led to the design of novel storage architecture that support next generation object-based storage technology. 相似文献
60.
Di Wu Bang Lin Li Qianwen Zhao Qian Liu Dong Wang Binfeng He Zhenghua Wei David Tai Leong Guansong Wang Hang Qian 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(19)
DNA nanostructures as scaffolds for drug delivery, biosensing, and bioimaging are hindered by its vulnerability in physiological settings, less favorable of incorporating arbitrary guest molecules and other desirable functionalities. Noncanonical self‐assembly of DNA nanostructures with small molecules in an alternative system is an attractive strategy to expand their applications in multidisciplinary fields and is rarely explored. This work reports a nitrogen‐enriched carbon dots (NCDs)‐mediated DNA nanostructure self‐assembly strategy. Given the excellent photoluminescence and photodynamic properties of NCDs, the obtained DNA/NCDs nanocomplex holds great potential for bioimaging and anticancer therapy. NCDs can mediate DNA nanoprism (NPNCD) self‐assembly isothermally at a large temperature and pH range in a magnesium‐free manner. To explore the suitability of NPNCD in potential biomedical applications, the cytotoxicity and cellular uptake efficiency of NPNCD are evaluated. NPNCD with KRAS siRNA (NPNCDK) is further conjugated for KRAS‐mutated nonsmall cell lung cancer therapy. The NPNCDK shows excellent gene knockdown efficiency and anticancer effect in vitro. The current study suggests that conjugating NCDs with programmable DNA nanostructures is a powerful strategy to endow DNA nanostructures with new functionalities, and NPNCD may be a potential theranostic platform with further fine‐tuned properties of CDs such as near‐red fluorescence or photothermal activities. 相似文献