4,666 research outputs found

    A Loss-Free Micropayment Protocol for Multimedia Services

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    A micropayment scheme is proposed to enable transactions of different denominations and to eliminate possibilities that either the vendor or the user in a payment system misbehaves to get illegal profit. The proposed offers a solution while keeping transactions efficient

    Greater Privacy Protection for Online Credit Card Payment

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    Privacy is always one of the primary concerns in electronic commerce. Consumers must have the right to keep their buying habits and personal information confidential, especially when it comes to on-line credit card payment. Not just only because this payment method has been becoming the trend of modern consuming practice, but also it involves the sensitivity of privacy information. Based on the need-to-know principle, transaction information should be distributed properly among participants to be against aggregation and analysis. In this paper, the privacy required for on-line credit card payment is described, and the privacy protection on three common payment protocols such as SSL, SET and 3D SET are also analyzed in detail. Two solutions are then proposed to enhance privacy protection for cardholder

    {Bis[4-(2-pyrid­yl)pyrimidin-2-yl]sulfane}dichloridocobalt(II)

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    The asymmetric unit of the title compound, [CoCl2(C18H12N6S)], contains one half-mol­ecule situated on a twofold rotation axis which passes through the Co and S atoms. The metal centre is in a distorted octahedral CoCl2N4 coordination with the Cl atoms in the axial positions. In the crystal structure, inter­molecular C—H⋯Cl inter­actions help to establish the packing

    The State-of-the-Art Practices of the Internet Banking in Taiwan

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    This paper reports an investigation into the state-of-the-art practices of Internet banking in Taiwan. Emphasis is focused on the adoption of security technology. Three kinds of security utilities—SSL, SET, and Non-SET—are compared in terms of risks and supported functions. The author also analyzes factors that influence the development of Internet banking. The Ministry of Finance of the Taiwanese government has adopted a policy that fosters the development of Internet banking. However, understanding security technologies demands in-depth expert knowledge, and goes beyond the capacity of general citizens. The authors suggest that the first priority is given to the authority’s promulgation of laws and guidelines. Second, the banking industry needs to integrate the security mechanisms of Internet banking services with the existing environment. Finally, a risk allotment policy would help to remove fear and doubt from customer’s minds

    Comparison of the protein acetylome of endothelial cells upon shear flow and resveratrol treatment

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    Background: Posttranslational acetylation/deacetylation known as the acetylome is important in regulating protein activity. Shear flow (SF) and resveratrol (RSV) are two stimuli that represent physical and chemical signal separately. The acetylome co-regulated by these two stimuli remain unclear. Methods: Human umbilical cord vein endothelial cells (HUVECs) were subjected to either SF of 12 dynes/cm2 or 10 μM RSV. The purified acetylated peptides were labeled by isobaric tags for relative and absolute quantitation (iTRAQ) analysis. The signaling cascades of the identified acetylome were predicted by ingenuity pathway analysis (IPA). Co-immunoprecipitation was applied to confirm the acetylation status of proteins. Results: Five groups of proteins showed an increased acetylation upon SF and RSV treatment. After algorithm, 628 proteins with increased acetylation and 22 proteins with decreased acetylation were identified in the SF acetylome. For the acetylome regulated by RSV, 145 proteins with increased acetylation and 23 proteins with decreased acetylation were identified. Compared these two acetylomes, 129 proteins with increased acetylation and 2 proteins with decreased acetylation were co-regulated by both SF and RSV treatments. IPA analysis showed that this co-regulated acetylome was involved in heat shock response, and the signals of eNOS, STAT3, JAK/STAT and ERK/MAPK. Co-immunoprecipitation analysis further confirmed the acetylated status of mitochondrial HSP60 and mitochondrial citrate synthase. Conclusions: This study indicated that physical signal is more complicated than chemical signal in the case of acetylome. The co-regulated proteins are worthy for further study in discussing synergetic effect between physical and chemical signal in cardioprotection

    Investigation of thin films of organic-based magnets grown by physical vapor deposition

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    Thin films of organic-based magnet, V[TCNE]x (TCNE: tetracyanoethylene), were deposited by physical vapor deposition (PVD) based reactive evaporation. The growth conditions were studied in detail. A saturated composition of V[TCNE]???1.9 was determined by optimizing the growth condition. Two sets of films with different V to TCNE ratios were characterized. Both films were magnetic ordered up to 400 K and held coercive field of 60 Oe at room temperature. With the presence of excess vanadium within the film, the increase of defects created by PVD results in significant change in electronic property.open0

    Room-temperature organic-based spin polarizer

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    We report a magnetic tunnel junction operating at room-temperature with organic magnetic semiconductor V[TCNE](x) (x similar to 2, TCNE: tetracyanoethylene) and Fe as the spin polarizer and analyzer while 10 mu rubrene layer serves as the tunnel barrier between them. At room-temperature, the magnetoresistance (MR) presents 16.7% of its peak value at 100K. We observed sign inversion of MR with increasing temperature, while the sign of the MR is independent of the polarity of the bias voltages. Our results suggest that V[TCNE](x) is a promising material for room-temperature spintronic applications.open5

    Prevascularization of 3D printed bone scaffolds by bioactive hydrogels and cell co-culture

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    Vascularization is a fundamental prerequisite for large bone construct development and remains one of the main challenges of bone tissue engineering. Our current study presents the combination of 3D printing technique with a hydrogel-based prevascularization strategy to generate prevascularized bone constructs. Human adipose derived mesenchymal stem cells (ADMSC) and human umbilical vein endothelial cells (HUVEC) were encapsulated within our bioactive hydrogels, and the effects of culture conditions on in vitro vascularization were determined. We further generated composite constructs by forming 3D printed polycaprolactone/hydroxyapatite scaffolds coated with cell-laden hydrogels and determined how the co-culture affected vascularization and osteogenesis. It was demonstrated that 3D co-cultured ADMSC-HUVEC generated capillary-like networks within the porous 3D printed scaffold. The co-culture systems promoted in vitro vascularization, but had no significant effects on osteogenesis. The prevascularized constructs were subcutaneously implanted into nude mice to evaluate the in vivo vascularization capacity and the functionality of engineered vessels. The hydrogel systems facilitated microvessel and lumen formation and promoted anastomosis of vascular networks of human origin with host murine vasculature. These findings demonstrate the potential of prevascularized 3D printed scaffolds with anatomical shape for the healing of larger bone defects
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