474,113 research outputs found
Pleurospermum tripartitum sp nov (Umbelliferae) from western Yunnan, China
No full textPleurospermum tripartitum Pu, R. Li & H. Li, a new species of Umbelliferae from western Yunnan, China, is described and illustrated. It is closely similar to P. macrochlaenum K. T. Fu & Y. C. Ho, but differs by having unbranched stem, conspicuous calyx teeth, and white petals
Ligusticum gongshanense sp nov (Umbelliferae) from western Yunnan, China
No full textLigusticum gongshanense Pu, R. Li & H. Li, a new species of Umbelliferae from western Yunnan, China, is described and illustrated. It is closely similar to L. franchetii H. de Boissieu, but differs by having unbranched and light yellow stem, white petals, and styles shorter than stylopodium
Study on the Mg-Li-Zn ternary alloy system with improved mechanical properties, good degradation performance and different responses to cells
No full textNovel Mg-(3.5, 6.5wt%)Li-(0.5, 2, 4wt%)Zn ternary alloys were developed as new kinds of biodegradable metallic materials with potential for stent application. Their mechanical properties, degradation behavior, cytocompatibility and hemocompatibility were studied. These potential biomaterials showed higher ultimate tensile strength than previously reported binary Mg-Li alloys and ternary Mg-Li-X (X=Al, Y, Ce, Sc, Mn and Ag) alloys. Among the alloys studied, the Mg-3.5Li-2Zn and Mg-6.5Li-2Zn alloys exhibited comparable corrosion resistance in Hank's solution to pure magnesium and better corrosion resistance in a cell culture medium than pure magnesium. Corrosion products observed on the corroded surface were composed of Mg(OH)2, MgCO3 and Ca-free Mg/P inorganics and Ca/P inorganics. In vitro cytotoxicity assay revealed different behaviors of Human Umbilical Vein Endothelial Cells (HUVECs) and Human Aorta Vascular Smooth Muscle Cells (VSMCs) to material extracts. HUVECs showed increasing nitric oxide (NO) release and tolerable toxicity, whereas VSMCs exhibited limited decreasing viability with time. Platelet adhesion, hemolysis and coagulation tests of these Mg-Li-Zn alloys showed different degrees of activation behavior, in which the hemolysis of the Mg-3.5Li-2Zn alloy was lower than 5%. These results indicated the potential of the Mg-Li-Zn alloys as good candidate materials for cardiovascular stent applications. Statement of significance: Mg-Li alloys are promising as absorbable metallic biomaterials, which however have not received significant attention since the low strength, controversial corrosion performance and the doubts in Li toxicity. The Mg-Li-Zn alloy in the present study revealed much improved mechanical properties higher than most reported binary Mg-Li and ternary Mg-Li-X alloys, with superior corrosion resistance in cell culture media. Surprisingly, the addition of Li and Zn showed increased nitric oxide release. The present study indicates good potential of Mg-Li-Zn alloy as absorbable cardiovascular stent material.Accepted Author ManuscriptBiomaterials & Tissue Biomechanic
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Structural Changes in Li2MnO3 Cathode Material for Li-Ion Batteries
No full textStructural changes in Li2MnO3 cathode material for rechargeable Li-ion batteries are investigated during the first and 33 rd cycles. It is found that both the participation of oxygen anions in redox processes and Li+-H+ exchange play an important role in the electrochemistry of Li2MnO3. During activation, oxygen removal from the material along with Li gives rise to the formation of a layered MnO2-type structure, while the presence of protons in the interslab region, as a result of electrolyte oxidation and Li+-H+ exchange, alters the stacking sequence of oxygen layers. Li re-insertion by exchanging already present protons reverts the stacking sequence of oxygen layers. The re-lithiated structure closely resembles the parent Li2MnO3, except that it contains less Li and O. Mn4+ ions remain electrochemically inactive at all times. Irreversible oxygen release occurs only during activation of the material in the first cycle. During subsequent cycles, electrochemical processes seem to involve unusual redox processes of oxygen anions of active material along with the repetitive, irreversible oxidation of electrolyte species. The deteriorating electrochemical performance of Li2MnO3 upon cycling is attributed to the structural degradation caused by repetitive shearing of oxygen layers. Structural changes in Li2MnO3 provide evidence for the unusual electrochemical processes such as Li+-H+ exchange and the participation of oxygen anions in redox reactions. The observed decline in the electrochemical performance of the material upon cycling, mainly attributed to the Li+-H+ exchange and associated structural changes, also provides a global explanation for the reported cycling behavior of Li2MnO3-containing Li-rich cathode materials. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
Full text linkBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
LI R 9.3 m/s
No full textSimulation vs experimental testing output comparison for the Hybrid III head form linear impacts (LI) impact location R 9.3 m/s
LI R 5.5 m/s
No full textSimulation vs experimental testing output comparison for the Hybrid III head form linear impacts (LI) impact location R 5.5 m/s
KWB-R/pkgmeta: pkgmeta (v0.2.2): R Package for meta-analysis of KWB-R packages on GitHub
No full text<h2>What's Changed</h2>
<ul>
<li>Bump version by @mrustl in https://github.com/KWB-R/pkgmeta/pull/14</li>
<li>Dev by @mrustl in https://github.com/KWB-R/pkgmeta/pull/15</li>
<li>Do not eval vignettes on R universe by @mrustl in https://github.com/KWB-R/pkgmeta/pull/16</li>
<li>Dev by @mrustl in https://github.com/KWB-R/pkgmeta/pull/17</li>
<li>Release v0.2.2 by @mrustl in https://github.com/KWB-R/pkgmeta/pull/18</li>
</ul>
<p><strong>Full Changelog</strong>: https://github.com/KWB-R/pkgmeta/compare/v0.2.1...v0.2.2</p>
LI R 7.4 m/s
No full textSimulation vs experimental testing output comparison for the Hybrid III head form linear impacts (LI) impact location R 7.4 m/s
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