204 research outputs found

    Auricular Reconstruction Using a Porous Polyethylene Framework

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    AbstractObjectiveTo report utility of Medpor frameworks in auricular reconstruction and management of frameworks protrusion.MethodsRetrorespectively analysis of clinical information in 31 patients who underwent auricular reconstruction from April 2000 to October 2002.ResultsAll 31 reconstructed auricles were in good condition at two weeks postoperatively. Framework protrusion occurred later in 11 patients. The framework was retained in 8 of these cases after secondary repair, but had to be removed in 3 patients. In 27 patients, the reconstructed auricle was rated as esthetically succesful.ConclusionMedpor framework protrusion is likely to occur when skin tension is high with minimal soft tissue coverage over the framework and can result from impact by strong external force. Despite the concern of protrusion, Medpor frameworks can be used in place of autologous cartilaginous graft in auricular reconstruction

    Bis(2-amino-6-methyl­pyridinium) tetra­chloridocuprate(II)

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    The title compound, (C6H9N2)2[CuCl4], contains a distorted tetra­hedral [CuCl4]2− anion and two protonated amino­pyridinium cations. The geometries of the protonated amino­pyridinium cations reveal amine–imine tautomerism. The crystal packing is influenced by N—H⋯Cl and C—H⋯Cl hydrogen bonds and π–π stacking inter­actions [centroid–centroid distances = 3.635 (4) and 3.642 (4)°]

    2-Amino-3-methyl­pyridinium 2-amino-5-methyl­pyridinium sulfate monohydrate

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    The asymmetric unit of the title compound, 2C6H9N2 +·SO4 2−·H2O, contains two isomeric protonated amino­methyl­pyridine cations, a sulfate anion and a solvent water mol­ecule. The cations are in the iminium tautomeric form. In the crystal structure, inter­molecular O—H⋯O, N—H⋯O and weak C—H⋯O hydrogen bonds link the components into a three-dimensional network. Additional stabilization is provided by weak π–π stacking inter­actions, with centroid–centroid distances of 3.758 (2) and 3.774 (1) Å

    Cognitive Non-Orthogonal Multiple Access with Cooperative Relaying:A New Wireless Frontier for 5G Spectrum Sharing

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    Two emerging technologies toward 5G wireless networks, namely non-orthogonal multiple access (NOMA) and cognitive radio (CR), will provide more efficient utilization of wireless spectrum in the future. In this article, we investigate the integration of NOMA with CR into a holistic system, namely a cognitive NOMA network, for more intelligent spectrum sharing. Design principles of cognitive NOMA networks are perfectly aligned to functionality requirements of 5G wireless networks, such as high spectrum efficiency, massive connectivity, low latency, and better fairness. Three different cognitive NOMA architectures are presented, including underlay NOMA networks, overlay NOMA networks, and CR-inspired NOMA networks. To address inter-network and intra-network interference, which largely degrade the performance of cognitive NOMA networks, cooperative relaying strategies are proposed. For each cognitive NOMA architecture, our proposed cooperative relaying strategy shows its potential to significantly lower outage probabilities. We discuss open challenges and future research directions on implementation of cognitive NOMA networks

    Influencing factors and clinical significance of the metastatic lymph nodes ratio in gastric adenocarcinoma

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    <p>Abstract</p> <p>Background</p> <p>To investigate influencing factors of the metastatic lymph nodes ratio (MLR) and whether it is related to survival in patients with gastric adenocarcinoma.</p> <p>Methods</p> <p>We retrospectively evaluated the clinical features of 121 patients with gastric adenocarcinoma enrolled in our hospital between 2000 and 2007. The receiver operating characteristic (ROC) curve was used to determine the cutoff of the MLR, and CK20 immunohistochemical staining was used to detect micrometastasis of the lymph nodes.</p> <p>Results</p> <p>The areas under the ROC curve of MLR used to predict the death of 3-year and 5-year postoperative patients were 0.826 ± 0.053 and 0.896 ± 0.046. Thus MLR = 30.95% and MLR = 3.15% were designated as cutoffs. The MLR was then classified into three groups: MLR<sub>1 </sub>(MLR<3.15%); MLR<sub>2</sub>(3.15% ≤ MLR ≤ 30.95%); and MLR<sub>3 </sub>(MLR>30.95%). We found that patients with a higher MLR demonstrated a much poorer survival period after radical operation than those patients with a lower MLR (P = 0.000). The COX model showed that MLR was an independent prognostic factor (P = 0.000). The MLR could also discriminate between subsets of patients with different 5-year survival periods within the same N stage (P < 0.05). The MLR has been shown to be 34.7% (242/697) by HE staining and 43.5% (303/697) by CK staining (P = 0.001). The clinicopathological characteristics of lymph vessel invasion and the depth of invasion could significantly affect the MLR.</p> <p>Conclusion</p> <p>MLR is an independent prognostic factor in gastric cancer. The combined ROC curve with MLR is an effective strategy to produce a curve to predict the 3-year and 5-year survival rates.</p

    Silicic ash beds bracket Emeishan Large Igneous Province to < 1 m.y. at ~ 260 Ma

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    This research was supported by the Open Fund (PLC201404) of State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation (Chengdu University of Technology), the National Natural Science Foundation of China (41502109), Project funded by China Postdoctoral Science Foundation (2015 M582528) and the Fundamental Research Funds for the Central Universities, Chengdu University of Technology.Claystone beds directly below and above the Emeishan basalts in SW China formed around the Guadalupian-Lopingian (G-L) boundary. Zircons from both levels give U–Pb ages of ~ 260 Ma, and are identical within-error to ages reported for the Emeishan Large Igneous Province (LIP). The claystones lack Nb-Ta anomalies on primitive mantle normalized elemental diagrams; zircons from these claystones have a geochemical affinity to within-plate-type magmas. These features, combined with the strong negative Eu anomalies in the zircons and high Al2O3/TiO2 ratios, indicate that claystones around the G-L boundary have a silicic volcanic component related to Emeishan LIP. Zircons from the underlying claystone bed have much higher U/Yb and Th/Nb ratios and lower εHf(t) values than those overlying the LIP, suggesting that early-stage silicic volcanic rocks had a higher crustal contamination or assimilation during magmatic processes. In terms of stratigraphic correlation, our data demonstrate that silicic eruptions occurred not only at the end, but also at the beginning of the Emeishan LIP, and the overall duration of the main basaltic phase was short (< 1 m.y).PostprintPeer reviewe

    Cooperative Non-Orthogonal Layered Multicast Multiple Access for Heterogeneous Networks

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    This paper proposes a novel design of cooperative non-orthogonal layered multicast multiple access in a heterogeneous network, where the information is encoded into the messages of high-priority (HP) and low-priority (LP). Two types of multicast users coexist in the network: 1) regular users (RUs), which are located far away from the base-station (BS) and expect to decode only the HP message (due to the weak channels); 2) advanced users (AUs), which are located close to the BS and expect to decode both HP and LP messages. To improve the reliability of layered multicast, we consider that the successful AUs (those AUs who successfully decode the HP and LP messages) serve as potential relays to assist other AUs/RUs. Based on this idea, two novel cooperation strategies are proposed for different cases of channel information availability. For each proposed strategy, we derive closed-form exact outage probabilities of AUs and RUs, and then further analyze their diversity orders. Moreover, considering that the layered multicast is outage-constrained, we theoretically evaluate the energy consumption of both strategies and demonstrate their energy saving gains over the direct non-orthogonal multiple access for layered multicast. Finally, our theoretical analysis is verified by numerical results, and the advantages of the proposed strategies are also demonstrated
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