1,581 research outputs found

    Antioxidant and antibacterial activity of Toddalia asiatica (Linn) Lam root extracts

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    Background: Toddalia asiatica (Linn) Lam is a woody vine that is used medicinally in China, India, and East Africa. The aim of the present study was to examine the antioxidant and antibacterial activity of the roots of Toddalia asiatica (Linn) Lam (TA).Materials and Methods: The antioxidant capacity of TA roots was determined using 1,1 iphenyl-2-picrylhydrazyl (DPPH), 2,2´-azino-bis (3-ethylbenzo-thiazoline-6-sulfonicacid) (ABTS), and the ferric reducing antioxidant potential (FRAP) assay. The antimicrobial activity of TA against Staphylococcus aureus (SA), methicillin-resistant S. aureus (MRSA), and extended spectrum β-lactamase positive S. aureus (ESBLs-SA) was screened.Results: Methanol and ethyl acetate extracts of TA exhibited strong antioxidant activity. The methanol extract had the highest antioxidant activity (DPPH, IC50=41.45 μg/mL; ABTS, IC50=8.34 μg/mL; FRAP=1304.8 ± 60.38 μmol Trolox equivalent (TE)/g), which was close to that of the positive control, butylated hydroxytoluene (BHT). The petroleum ether extract of TA showed the highest antimicrobial activity (SA, minimum inhibitory concentration (MIC) = 250 μg/disc; MRSA, MIC=125 μg/disc) when compared with that of ethyl acetate extract (SA, MIC=250 μg/disc) and methanol extract.Conclusions: Investigation of methanol, petroleum ether, and ethyl acetate extracts of TA root revealed robust antioxidant activity in methanol extracts and strong antimicrobial activity against SA and MRSA in petroleum ether extracts.Keywords: Toddalia asiatica (Linn) Lam; antioxidant; antibacteria

    The Biological Function of Kupffer Cells in Liver Disease

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    Kupffer cells, which have a characteristic morphology and a kind of phenotype, are the resident macrophages in liver, serve as the largest population mononuclear phagocytes in the body, and are localized in the periportal zone. They have phagocytosis capacity and release all kinds of cytokines, chemokines, and soluble biological mediators. Owing to the different functions of Kupffer cells, they play an important role in liver diseases. In this chapter, we review the role of Kupffer cells in infectious disease, fatty liver disease, liver fibrosis, liver ischemia-reperfusion injury, liver transplantation immunology, as well as liver cancer and metastases

    Learning Sparse Representations for Fruit Fly Gene Expression Pattern Image Annotation and Retreival

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    Background: Fruit fly embryogenesis is one of the best understood animal development systems, and the spatiotemporal gene expression dynamics in this process are captured by digital images. Analysis of these high-throughput images will provide novel insights into the functions, interactions, and networks of animal genes governing development. To facilitate comparative analysis, web-based interfaces have been developed to conduct image retrieval based on body part keywords and images. Currently, the keyword annotation of spatiotemporal gene expression patterns is conducted manually. However, this manual practice does not scale with the continuously expanding collection of images. In addition, existing image retrieval systems based on the expression patterns may be made more accurate using keywords. Results: In this article, we adapt advanced data mining and computer vision techniques to address the key challenges in annotating and retrieving fruit fly gene expression pattern images. To boost the performance of image annotation and retrieval, we propose representations integrating spatial information and sparse features, overcoming the limitations of prior schemes. Conclusions: We perform systematic experimental studies to evaluate the proposed schemes in comparison with current methods. Experimental results indicate that the integration of spatial information and sparse features lead to consistent performance improvement in image annotation, while for the task of retrieval, sparse features alone yields better results

    Learning Sparse Representations for Fruit Fly Gene Expression Pattern Image Annotation and Retreival

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    Background: Fruit fly embryogenesis is one of the best understood animal development systems, and the spatiotemporal gene expression dynamics in this process are captured by digital images. Analysis of these high-throughput images will provide novel insights into the functions, interactions, and networks of animal genes governing development. To facilitate comparative analysis, web-based interfaces have been developed to conduct image retrieval based on body part keywords and images. Currently, the keyword annotation of spatiotemporal gene expression patterns is conducted manually. However, this manual practice does not scale with the continuously expanding collection of images. In addition, existing image retrieval systems based on the expression patterns may be made more accurate using keywords. Results: In this article, we adapt advanced data mining and computer vision techniques to address the key challenges in annotating and retrieving fruit fly gene expression pattern images. To boost the performance of image annotation and retrieval, we propose representations integrating spatial information and sparse features, overcoming the limitations of prior schemes. Conclusions: We perform systematic experimental studies to evaluate the proposed schemes in comparison with current methods. Experimental results indicate that the integration of spatial information and sparse features lead to consistent performance improvement in image annotation, while for the task of retrieval, sparse features alone yields better results

    Experimental study of a new type of floating breakwater

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    A new type of floating breakwater (FB) is proposed in this paper. Its hydrodynamic performance has been tested. The structure of the new breakwater named cylindrical floating breakwater (CFB) consists of two parts: a main body of rigid cylinders, and a flexible mesh cage containing a number of suspending balls that are intended to absorb the wave energy into their mechanical energy. A series of experiments were carried out on the new floating breakwater and traditional double pontoons and box floating breakwaters to compare their performances. A two-dimensional wave flume was used in the experiment; the incident and transmitted waves, the tensions on the mooring lines and the motion responses of the floating breakwaters were measured. Results showed that the new floating breakwater had a better performance than the traditional double pontoons and the box floating breakwaters: wave transmission was significantly reduced by the mesh cage with the balls, especially for long waves

    Theoretical and numerical estimation of ship-to-ship hydrodynamic interaction effects

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    The main objective of this paper is to investigate theoretically and numerically how much interactions are expected between two ships travelling in waves. The theoretical estimation is based on asymptotic far-field wave patterns produced by a translating and oscillating source. The far-field wave pattern is governed by the parameter τ=ωeu0/g; For values of the parameter τ>0.25 there exist a fan-shaped quiescent region in front of the vessel. As τ increases, the range of the fan-shaped quiescent region will be expanded. The critical line between the quiescent and wake region can be estimated by the asymptotic expressions theoretically. It is expected that there is no hydrodynamic interaction if the two ships are located in each other's fan-shaped quiescent region. But due to the near-field local waves produced by the 3-D ships, the critical line could be different from that estimated from asymptotic wave pattern. Therefore, we developed a 3-D panel method based on Rankine-type Green function to investigate the hydrodynamic interaction effects for several combinations of parameters, including oscillation frequency, forward speed and transverse distance between two ships. Finally, the critical line calculated numerically was presented and compared to the theoretical estimation

    Moisture susceptibility of warm mix asphalt (WMA) with an organic wax additive based on X-ray computed tomography (CT) technology

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    The warm mix asphalt was fabricated with different moisture contents (0%, 1%, 2%, and 3%) of limestone aggregates using the Superpave gyratory compactor. The moisture susceptibility of asphalt mixtures with an organic wax additive RH was studied. The samples were compacted and tested using the modified Lottman test AASHTO T283, and the X-ray computed tomography technology was used to capture the internal structure images before and after the freeze-thaw cycles. The test results show that the air voids were distributed in the size range of 0–5 mm3 and 5–10 mm3. The number of air voids decreased with the increase of air void size and increased after freeze-thaw cycles. The air void content can be influenced by the residual moisture in aggregates. The higher the moisture content of aggregates is, the larger the air void content is. So, the air void content is likely to be sensitive to moisture damage. The increase ratio of the air void and moisture content of aggregates had good correlation with the indirect tensile strength and tensile strength ratio of the samples. The indirect tensile strength and tensile strength ratio of the samples decreased linearly, and the samples were sensitive to the moisture damage with the increases of increase ratio of the air void/moisture content in aggregates
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