6,896 research outputs found

    The Empirical Research about the Impact of Seller Reputation on C2C Online Trading: The Case of Taobao

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    With the improvement of China\u27s Internet penetration and a shift in consumption consciousness, user scale and market size of online trading reached a new height, and C2C e-commerce has the most rapid development. As the seller and buyer of online transaction in a state of isolation in time and space, there is serious information asymmetry. So the reputation problems that exist in the online trading have become the concern of many people. The seller reputation can evaluate the past behavior of seller. Hence, the higher reputation can reduce the potential risk of the transaction and increase the transaction tendencies and actions of buyers. Due to the biggest market share of the C2C e-commerce platform in China and a higher awareness of user groups, Taobao.com is selected as research subject. We collected 1379 useful seller reputation information from five merchandise categories. Then, hypotheses about the influence of online sales volume and price were put forward, and the research model was established. Next, correlation analysis and linear regression analysis was employed to test hypotheses and the research model in the C2C online trading environment. The results showed that reputation rating and reputation score has a significant positive effect on sales volume and price, and there is a negative impact on the sales of the existence of violation. Match degree of description, seller attitude and delivery speed in the dynamic rating have a greater impact on sales price than volume. Match degree of description and delivery speed has a promoting role. Freight borne by the seller has a positive impact on sales volume

    Posterior-only spinal fusion without rib head resection for treating type I neurofibromatosis with intra-canal rib head dislocation

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    OBJECTIVES: Patients with Type I neurofibromatosis scoliosis with intra-canal rib head protrusion are extremely rare. Current knowledge regarding the diagnosis and treatment for this situation are insufficient. The purpose of this study is to share our experience in the diagnosis and surgical treatments for such unique deformities. METHODS: Six patients with Type I neurofibromatosis scoliosis with rib head dislocation into the spinal canal were diagnosed at our institution. Posterior instrumentation and spinal fusion without intra-canal rib head resection via a posterior-only approach was performed for deformity correction and rib head extraction. The efficacy and outcomes of the surgery were evaluated by measurements before, immediately and 24 months after the surgery using the following parameters: coronal spinal Cobb angle, apex rotation and kyphosis of the spine and the intra-canal rib head position. Post-operative complications, surgery time and blood loss were also evaluated. RESULTS: Patients were followed up for at least 24 months post-operatively. The three dimensional spinal deformity was significantly improved and the intra-canal rib head was significantly extracted from the canal immediately after the surgery. At follow-up 24 months after surgery, solid fusions were achieved along the fusion segments, and the deformity corrections and rib head positions were well maintained. There were no surgery-related complications any time after the surgery. CONCLUSIONS: Systematic examinations are needed to identify patients with Type I neurofibromatosis scoliosis with rib head dislocation into the canal who can be treated by posterior-only spinal fusion without rib head resection

    Finite-dimensionality of attractors for wave equations with degenerate nonlocal damping

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    In this paper we study the fractal dimension of global attractors for a class of wave equations with (single-point) degenerate nonlocal damping. Both the equation and its linearization degenerate into linear wave equations at the degenerate point and the usual approaches to bound the dimension of the entirety of attractors do not work directly. Instead, we develop a new process concerning the dimension near the degenerate point individually and show the finite dimensionality of the attractor.Comment: 33 page

    Post-synthetic and site-specific modification of endocyclic nitrogen atoms of purines in DNA and its potential for biological and structural studies

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    Site-specific modification of the N1-position of purine was explored at the nucleoside and oligomer levels. 2'-Deoxyinosine was converted into an N1-2,4-dinitrophenyl derivative 2 that was readily transformed to the desired N1-substituted 2'-deoxyinosine analogues. This approach was used to develop a post-synthetic method for the modification of the endocyclic N1-position of purine at the oligomer level. The phosphoramidite monomer of N1-(2,4-dinitrophenyl)-2'-deoxyinosine 9 was prepared from 2'-deoxyinosine in four steps and incorporated into oligomers using an automated DNA synthesizer. The modified base, N1-(2,4-dinitrophenyl)-hypoxanthine, in synthesized oligomers, upon treatment with respective agents, was converted into corresponding N1-substituted hypoxanthines, including N1-15N-hypoxanthine, N1-methylhypoxanthine and N1-(2-aminoethyl)-hypoxanthine. These modified oligomers can be easily separated and high purity oligomers obtained. Melting curve studies show the oligomer containing N1-methylhypoxanthine or N1-(2-aminoethyl)-hypoxanthine has a reduced thermostability with no particular pairing preference to either cytosine or thymine. The developed method could be adapted for the preparation of oligomers containing mutagenic N1-ß-hydroxyalkyl-hypoxanthines and the availability of the rare base-modified oligomers should offer novel tools for biological and structural studies
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