2,386 research outputs found
Concentration dependence of the up- and down-conversion emission colours of Er3+-doped Y2O3: a time-resolved spectroscopy analysis
Er3+ energy transfer mechanisms and their influence on the dynamics and emission colours are considered for upconversion and downconversion regimes.</jats:p
Use of strontium-enriched bioactive bone cement in enhancing tendon osteointegration in a rabbit anterior cruciate ligament reconstruction model
Conference Theme: Defying the Aging Spine: Our Mission ContinuesConcurrent Free Papers 5 - Sports: no. 5.17Introduction: It was hypothesised that strontium led to accelerated healing of strontium-enriched calcium phosphate
cement (Sr-CPC)–treated soft tissue tendon graft within the bone tunnel in anterior cruciate ligament (ACL) reconstruction.
This hypothesis was tested in a rabbit ACL reconstruction model using Achilles tendon allograft.
Methods: A total of 30 bilateral ACL reconstructions were performed in 15 rabbits. The graft on the tested limb was treated
with Sr-CPC, while that on the contralateral limb was treated with CPC. Three were sacrificed for histomorphometric
analysis respectively at 3, 6, 9, 12, and 24 weeks after the index operation. Histomorphometric analysis of the healing of
graft was done by 2 independent observers in 42 histological zones per animal using a scoring system of 0 to 9. The data
were analysed by Mann-Whitney U test.
Results: Accelerated healing of the graft within bone tunnel was noted in the strontium-treated limb at 3, 6, 9, and 12 weeks
after the operation (p < 0.001) when compared with the CPC-treated limb. Complete healing of the graft by Sharpey’s fibre
formation at 9 weeks and early evidence of remodelling into normal ACL insertion site at 12 weeks were noted in the SrCPC
group. The healing of the graft in the CPC-treated limb was noted 3 to 6 weeks slower than the Sr-CPC group.
Conclusion: Strontium is the main contributing factor leading to accelerated healing of Sr-CPC–treated soft tissue tendon
graft in a rabbit ACL reconstruction model.postprin
Local Application of Strontium in a Calcium Phosphate Cement System Accelerates Healing of Soft Tissue Tendon Grafts in Anterior Cruciate Ligament Reconstruction: Experiment Using a Rabbit Model
Background: The healing of soft tissue tendon graft within the bone tunnel in anterior cruciate ligament (ACL) reconstruction is known to be slower than that of bone-patellar tendon-bone graft. There are attempts in accelerating the healing of the graft within the bone tunnel. One of the methods is the use of strontium-enriched calcium phosphate bone cement (Sr-CPC). The early result in animal study was encouraging, though it was not known whether the accelerated healing was solely due to the effect of the strontium within the cement, or due to the calcium phosphate cement (CPC) itself. Hypothesis: There would be differences between a strontium-enriched calcium phosphate cement (Sr-CPC) and a conventional calcium phosphate cement (CPC) in terms of the effect on soft tissue tendon graft healing within the bone tunnels in anterior cruciate ligament (ACL) reconstruction. Study Design: Controlled laboratory study. Methods: Thirty single bundle ACL reconstruction procedures were performed in 15 rabbits with the use of an Achilles tendon allograft. The graft on the left limb was coated with Sr-CPC, while that on the right limb was coated with CPC. Three animals were sacrificed for histological and histomorphometric analysis at 3, 6, 9, 12 and 24 weeks post-operation. Results: In the Sr-CPC group, early Sharpey fiber formation was present at 6 weeks post-operation while early remodeling of a graft-fibrocartilage-bone junction was noted at 12weeks. In the CPC group, early Sharpey fiber formation was only found at 9 to 12 weeks post-operation. At 24 weeks, a direct enthesis was found in both groups. According to histomorphometric score, graft healing in the Sr-CPC group took place 3 weeks faster than that in the CPC group at and before 12 weeks, but there was no difference at 24 weeks. Conclusion: The local application of strontium in a CPC system leads to accelerated graft healing within the bone tunnels. Clinical Relevance: The use of Sr-CPC to enhance graft-bone healing may improve the clinical results of ACL reconstruction using soft tissue tendon graft. Keywords: anterior cruciate ligament (ACL); strontium; calcium phosphate cementpostprin
Flowering of kiwifruit (Actinidia deliciosa) is reduced by long photoperiods
Mature kiwifruit (Actinidia deliciosa ‘Hayward’) vines grown under standard orchard management were exposed to 16-h photoperiods from the longest day in summer until after leaf fall in autumn. Photoperiod extension was achieved with tungsten halogen lamps that produced 2–8 µmols m–2 s–1 photosynthetically active radiation. Long day treatments did not affect fruit dry matter or fruit weight at harvest during the growing season that the treatments were applied or during the following growing season. However, flowering was reduced by 22% during the spring following treatment application. As this reduction in flowering was not accompanied by a decrease in budbreak, the long day effect is not consistent with a delay in the onset of winter chilling. It is suggested therefore, that the observed reduction in flowering may be because of a diminution of floral evocation
Visibility-based coverage of mobile sensors in non-convex domains
The area coverage problem of mobile sensor networks has attracted much attention recently, as mobile sensors find many important applications in remote and hostile environments. However, the deployment of mobile sensors in a non-convex domain is nontrivial due to the more general shape of the domain and the attenuation of sensing capabilities caused by the boundary walls or obstacles. We consider the problem of exploration and coverage by mobile sensors in an unknown non-convex domain. We propose the definition of 'visibility-based Voronoi diagram' and extend the continuous-time Lloyd's method, which only works for convex domains, to deploy the mobile sensors in the unknown environments in a distributed manner. Our simulations show the effectiveness of the proposed algorithms. © 2011 IEEE.published_or_final_versionThe 8th International Symposium on Voronoi Diagrams in Science and Engineering (ISVD2011), Qingdao, China, 28-30 June 2011. In Proceedings of the 8th ISVD, 2011, p. 105-11
Global Optimization of Centroidal Voronoi Tessellation with Monte Carlo Approach
published_or_final_versio
Use of strontium-enriched bioactive bone cement in enhancing tendon osteointegration in a rabbit anterior cruciate ligament reconstruction model
Conference Theme: Defying the Aging Spine: Our Mission ContinuesConcurrent Free Papers 5 - Sports: no. 5.17Introduction: It was hypothesised that strontium led to accelerated healing of strontium-enriched calcium phosphate
cement (Sr-CPC)–treated soft tissue tendon graft within the bone tunnel in anterior cruciate ligament (ACL) reconstruction.
This hypothesis was tested in a rabbit ACL reconstruction model using Achilles tendon allograft.
Methods: A total of 30 bilateral ACL reconstructions were performed in 15 rabbits. The graft on the tested limb was treated
with Sr-CPC, while that on the contralateral limb was treated with CPC. Three were sacrificed for histomorphometric
analysis respectively at 3, 6, 9, 12, and 24 weeks after the index operation. Histomorphometric analysis of the healing of
graft was done by 2 independent observers in 42 histological zones per animal using a scoring system of 0 to 9. The data
were analysed by Mann-Whitney U test.
Results: Accelerated healing of the graft within bone tunnel was noted in the strontium-treated limb at 3, 6, 9, and 12 weeks
after the operation (p < 0.001) when compared with the CPC-treated limb. Complete healing of the graft by Sharpey’s fibre
formation at 9 weeks and early evidence of remodelling into normal ACL insertion site at 12 weeks were noted in the SrCPC
group. The healing of the graft in the CPC-treated limb was noted 3 to 6 weeks slower than the Sr-CPC group.
Conclusion: Strontium is the main contributing factor leading to accelerated healing of Sr-CPC–treated soft tissue tendon
graft in a rabbit ACL reconstruction model.postprin
Impurity effects on charge transport and magnetoconductance in a single layer poly(3-hexyl-thiophene) device
received: 2016-01-10 accepted: 2016-05-05 published: 2016-05-17The work was supported by the China Scholarship Council and Engineering (HG, SC, HL, TZ, JH), National Science Foundation of China, 61574095, and Physical Sciences Research Council Grant Nos. EP/J50029X/1, EP/K004484/1, and EP/L020114/1
Solving the riddle of codon usage preferences: a test for translational selection
Translational selection is responsible for the unequal usage of synonymous codons in protein coding genes in a wide variety of organisms. It is one of the most subtle and pervasive forces of molecular evolution, yet, establishing the underlying causes for its idiosyncratic behaviour across living kingdoms has proven elusive to researchers over the past 20 years. In this study, a statistical model for measuring translational selection in any given genome is developed, and the test is applied to 126 fully sequenced genomes, ranging from archaea to eukaryotes. It is shown that tRNA gene redundancy and genome size are interacting forces that ultimately determine the action of translational selection, and that an optimal genome size exists for which this kind of selection is maximal. Accordingly, genome size also presents upper and lower boundaries beyond which selection on codon usage is not possible. We propose a model where the coevolution of genome size and tRNA genes explains the observed patterns in translational selection in all living organisms. This model finally unifies our understanding of codon usage across prokaryotes and eukaryotes. Helicobacter pylori, Saccharomyces cerevisiae and Homo sapiens are codon usage paradigms that can be better understood under the proposed model
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