检索结果-南通市图书馆

Engineered polycaprolactone–magnesium hybrid biodegradable porous scaffold for bone tissue engineering

Progress in Natural Science:Materials International 2014年第5期24卷 561-567页

作者： Hoi Man Wong Paul k.Chu Frankie k.L.Leung kenneth M.C.Cheung keith d.k.luk kelvin W.k.Yeung department of Orthopaedics and Traumatology The University of Hong Kong Shenzhen key Laboratory for Innovative Technology in Orthopaedic Trauma The University of Hong Kong Shenzhen Hospital department of Physics and Materials Science City University of Hong Kong Peking University Shenzhen Institution

In this paper, we describe the fabrication of a new biodegradable porous scaffold composed of polycaprolactone(PCL) and magnesium(Mg)micro-particles. The compressive modulus of PCL porous scaffold was increased to at least 150% by incorporating 29% Mg particles with the porosity of 74% using Micro-CT analysis. Surprisingly, the compressive modulus of this scaffold was further increased to at least 236% when the silane-coupled Mg particles were added. In terms of cell viability, the scaffold modified with Mg particles significantly convinced the attachment and growth of osteoblasts as compared with the pure PCL scaffold. In addition, the hybrid scaffold was able to attract the formation of apatite layer over its surface after 7 days of immersion in normal culture medium, whereas it was not observed on the pure PCL scaffold. This in vitro result indicated the enhanced bioactivity of the modified scaffold. Moreover, enhanced bone forming ability was also observed in the rat model after 3 months of implantation. Though bony in-growth was found in all the implanted scaffolds. High volume of new bone formation could be found in the Mg/PCL hybrid scaffolds when compared to the pure PCL scaffold. Both pure PCL and Mg/PCL hybrid scaffolds were degraded after 3 months. However, no tissue inflammation was observed. In conclusion, these promising results suggested that the incorporation of Mg micro-particles into PCL porous scaffold could significantly enhance its mechanical and biological properties. This modified porous bio-scaffold may potentially apply in the surgical management of large bone defect fixation.

关键词： Magnesium Polycaprolactone Biodegradability Biocompatibility Mechanical properties

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

磁共振弥散张量成像对脊髓型颈椎病患者术后神经功能恢复的预测作用

引用

中国脊柱脊髓杂志 2019年第5期29卷 385-393页

作者：李翔陆瓞骥胡勇香港大学深圳医院骨科深圳市创伤骨科新技术重点实验室广东省深圳市518053 香港大学矫形及创伤外科学系香港特别行政区

目的:探讨磁共振弥散张量成像(diffusion tensor imaging,dTI)在预测脊髓型颈椎病(cervical spondylotic myelopathy,CSM)患者术后神经功能恢复中的作用。方法:前瞻性分析50例行手术治疗的CSM患者的临床资料,患者年龄43~86岁(64.3±11.2... 详细信息

目的:探讨磁共振弥散张量成像(diffusion tensor imaging,dTI)在预测脊髓型颈椎病(cervical spondylotic myelopathy,CSM)患者术后神经功能恢复中的作用。方法:前瞻性分析50例行手术治疗的CSM患者的临床资料,患者年龄43~86岁(64.3±11.2岁)。以19例年龄50~62岁(54.6±4.2岁)的健康志愿者作为对照组。应用3.0T磁共振dTI成像序列,观察患者术前各神经纤维束感兴趣区(包括整个颈髓、颈髓前束、侧束及后束)中的各向异性分数(fractional anisotropy,FA)、平均弥散率(mean diffusivity,Md)、轴向弥散系数(axial diffusivity,Ad)及径向弥散系数(radial diffusivity,Rd),将患者按术后神经功能日本骨科协会(Japanese Orthopedic Association,JOA)评分改善率(recovery rate,RR)分为3组:优良疗效组(RR>0.7)、中等疗效组(RR 0.4~0.7)和一般疗效组(RRdTI参数值的差异,分析CSM患者脊髓神经束感兴趣区中的FA、Md、Ad和Rd值与神经功能改善率的相关性,并比较年龄、术前JOA评分、发病时间、MRI T2加权像脊髓高信号及dTI参数在预测CSM患者手术预后中的效果。结果:3个患者组的年龄、发病时间及术前JOA评分均无显著性差异(P>0.05)。除优良疗效组整个颈髓的FA值外,3个患者组的FA、Md和Rd值与对照组比较均存在显著性差异(Pd值外,CSM患者所有脊髓神经束感兴趣区中的FA、Md和Rd值均与神经功能改善率有显著相关性(Pd和Rd值与神经功能改善率呈负相关(PdTI参数值,尤其是脊髓后束及侧束FA值,在预测患者术后神经功能康复程度中表现出优于临床及传统影像学指标的特性,具有潜在的临床应用前景。

关键词：脊髓型颈椎病弥散张量成像手术预后

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

diabetic peripheral neuropathy and neuromodulation techniques:a systematic review of progress and prospects

引用

Neural Regeneration Research 2025年第8期20卷 2218-2230页

作者： Rahul Mittal keelin Mckenna Grant keith Evan Mckenna Joana R.N.Lemos Jeenu Mittal khemraj Hirani diabetes Research Institute University of Miami Miller School of MedicineMiamiFLUSA department of Otolaryngology University of Miami Miller School of MedicineMiamiFLUSA Herbert Wertheim College of Medicine Florida International UniversityMiamiFLUSA School of Medicine and Public Health University of WisconsinMadisonWIUSA

Neuromodulation for diabetic peripheral neuropathy represents a significant area of interest in the management of chronic pain associated with this *** peripheral neuropathy,a common complication of diabetes,is characterized by nerve damage due to high blood sugar levels that lead to symptoms,such as pain,tingling,and numbness,primarily in the hands and *** aim of this systematic review was to evaluate the efficacy of neuromodulatory techniques as potential therapeutic interventions for patients with diabetic peripheral neuropathy,while also examining recent developments in this *** investigation encompassed an array of neuromodulation methods,including frequency rhythmic electrical modulated systems,dorsal root ganglion stimulation,and spinal cord *** systematic review suggests that neuromodulatory techniques may be useful in the treatment of diabetic peripheral *** the advantages of these treatments will enable physicians and other healthcare providers to offer additional options for patients with symptoms refractory to standard pharmacologic *** these efforts,we may improve quality of life and increase functional capacity in patients suffering from complications related to diabetic neuropathy.

关键词： diabetes mellitus diabetic peripheral neuropathy neuromodulation neurostimulation therapy non-pharmacological treatment pain management

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Prognostic factors for a favorable outcome after varicocele repair in adolescents and adults

引用

Asian Journal of Andrology 2016年第2期18卷 217-221,J0004页

作者： Mary k Samplaski keith A Jarvi Institute of Urology University of Southern California Los Angeles CA USA division of Urology Department of Surgery Mount Sinai Hospital University of TorontoToronto Ontario Canada.

The effect of varicocele repair on male fertility remains controversial. It would be helpful to determined which men would benefit most from varicocele repair, and target repair efforts at those individuals. A detailed review of the literature on prognostic factors for varicocele repair was performed using the PubMed NLM database. We found that the best predictor of postvaricocelectomy semen parameters is the preoperative semen parameters. The greatest improvements in semen parameters were found in men with larger varicoceles. While there is controversy, higher testosterone, younger age and larger testis size, in some studies predict for improvements in semen parameters postvaricocelectomy. A nomogram has been developed to predict the postvaricocelectomy semen parameters based on the preoperative semen parameters, varicocele grade and the age of the man （***. com）. Limited data consistently demonstrates the greatest improvements in dNA fragmentation rates in men with higher baseline dNA fragmentation rates. With respect to reproductive outcomes, higher baseline sperm density consistently predicts for natural pregnancy or assisted reproductive technology （ART） pregnancy rates. In addition, varicocele repair does seem to reduce the need for more invasive modalities of ART. In conclusion, we can now start to use specific parameters such as baseline semen quality, varicocele grade and patient age to predict post-repair semen oualitv and fertility potential following varicocelectomy.

关键词： prediction prognosis varicocelectomy varicoceles

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Classification and management of the tandem ossification of the posterior longitudinal ligament and flaval ligament

引用

Chinese Medical Journal 2009年第2期122卷 219-224页

作者： GUO Jiong-jiong YANG Hui-lin kenneth M.C. Cheung TANG Tian-si keith d.k. luk department of Orthopaedics the First Affiliated Hospital of Soochow University Suzhou Jiangsu 215006 China department of Orthopaedics and Traumatology the University of Hong Kong Hong Kong SAR China

Objective To provide appropriate guidelines for treatment of tandem ossification of the posterior longitudinal ligament （OPLL） and flaval ligament （OFL）. data sources Published articles about OPLL and OFL were selected using Medline and Embase electronic databases. Study selection An English literature search from January 1980 to december 2006 was conducted. Because many reported cases were incorporated in OFL studies, the key words for search were OFL or OFL and OPLL. The first step revealed 93 studies of which 13 reports of tandem OPLL and OFL （tandem ossification） were selected. Results All studies were case series or case report and advocated that the primary therapy for tandem ossification should be operative. The clinical outcomes of surgery were evaluated in most reports, predominantly using the JOA scores. Gender is the only factor which has prognostic value. A higher proportion of women was found in the failure group A two- stage classification of tandem ossification was developed to relate diagnosis to outcome. Conclusions All patients with suspected ossification of the spinal ligaments should undergo routine MRI screening of the whole spine. The correlation of the classification with surgical treatments needs further studies to validate its usefulness. Chin Med J 2009; 122（2）：219-224

关键词： ossification posterior longitudinal ligament flaval ligament ligamentum flavum, tandem

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Attribution of Fano resonant features to plasmonic particle size, lattice constant, and dielectric wavenumber in square nanoparticle lattices

引用

Photonics Research 2014年第1期2卷 15-23页

作者： drew deJarnette Justin Norman d.keith Roper Microelectronics and Photonics Graduate Program University of ArkansasFayettevilleArkansas 72701USA department of Chemical Engineering University of ArkansasFayettevilleArkansas 72701USA

Fano resonances between plasmons and diffracted light offer tunable energies and locales,but attribution of Fano resonance features to geometry and physicochemistry of metal nanostructures and adjacent dielectrics has been confounded by complexity and computational *** work shows predictable modal shifts of Fano resonance in square lattices of plasmonic nanostructures can be attributed directly to changes in medium wavenumber,particle size,and lattice constant that alter plasmon polarizability and diffractive *** 45 to 80 nm radius particles,a window of lattice constants that support Fano resonances is identified in a range from 500 to 900 *** constants that support high intensity resonances are determined by individual particle polarizability and medium *** resonance wavelengths redshift from diffracted photon energies as local refractive index(RI)changes due to coupling with particle polarizability in the *** sensitivities for quadrupole,dipole,and Fano resonances are 150,348,and 541 nm,respectively,per RI *** resonance intensity may be enhanced more than tenfold by selecting nanoparticle sizes and lattice *** quantitative effects of such parametric changes are rapidly and intuitively distinguished using a semi-analytic approach,consisting of an exact expression for particle polarizability,a trigonometric description of diffraction,and a semianalytical coupled dipole approximation.

关键词： lattice particle wave

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

ANALYZING MARkET COMPETITION BETWEEN AIRBUS ANd BOEING USING A dUO HIERARCHICAL GRAPH MOdEL FOR CONFLICT RESOLUTION

引用

Journal of Systems Science and Systems Engineering 2017年第6期26卷 683-710页

作者： Shawei He keith W. Hipel d. Marc kilgour 1.College of Economics & Management Nanjing University of Aeronautics and Astronautics Nanjing 211106 China 2.Department of Systems Design Engineering University of Waterloo Waterloo Ontario Canada N2L 3G1 3.Centre for International Governance Innovation Waterloo Ontario Canada N2L 6C2 4.Balsillie School of International Affairs Waterloo Ontario Canada N2L 6C2 5.Department of Mathematics Wilfrid Laurier University Waterloo Ontario Canada N2L 3C5

A duo hierarchical graph model for conflict resolution is developed to investigate market competition between Airbus and Boeing over aircraft sales in the Asia Pacific region. The duo hierarchical graph model, a significant extension of the graph model for conflict resolution methodology, contains two common decision makers, who take part in two related subconflicts, as well as local decision makers, who participate in only one subconflict. New stability definitions are proposed to describe forms of sanction unique to the hierarchical model. The interrelationships between stabilities in the overall graph model and in the two local models are investigated. Then the duo hierarchical graph model is applied to the competition between Airbus and Boeing in both the wide and narrow body markets in the Asia-Pacific region. The two types of Asian airlines have different operating strategies, so that the two markets constitute sub-competitions that can be modelled naturally using the duo hierarchical graph model. The stability results indicate a resolution for all decision makers that implies marketing strategies for the aircraft manufacturers and guidelines for aircraft purchase by the airlines. Thus, this model provides decision makers with a comprehensive understanding of the dynamics of the comoetition and guidance in identifving beneficial actions.

关键词： Hierarchical Graph Model Airbus and Boeing stability results strategic resolutions

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Complementary Physical and Mechanical Techniques to Characterise Tooth: A Bone-like Tissue

引用

Journal of Bionic Engineering 2006年第1期3卷 19-31页

作者： Peter Zioupos keith d. Rogers Centre for Photo-manipulation and Photo-analysis of Materials Cranfield University Shrivenham SN 6 8LA UK Centre for Materials Science and Engineering Cranfield University Postgraduate Medical School Shrivenham SN 6 8LA UK

Bone like tissues are biocomposites comprising an organic matrix （mostly collagen） and a reinforcement phase in the form of mineral crystals （poorly stoichiometric apatite）. The composite properties are a result of the material characteristics of the two phases, their interaction, the relative composition, the orientation and the micro-architecture of the structure. The inherent spatial heterogeneity of these tissues （a result of evolutionary and functional requirements） and their exposure to various environmental and mechanical influences result in highly variable properties on the microscale, which can only be characterised by modern microanalytical methods. We present here results obtained by the complementary use of the modem nanoindentation and micro-X-ray diffraction techniques, which were used to probe the properties and structure of human dentine and enamel of primary molar teeth. The results show that both the addition and the higher organization of mineral within the organic matrix produce stiffer and harder tissue and that the examination of properties within small tissue volumes can be reliably achieved by use of these two methods in parallel. This opens new avenues in the study of biomaterial in general, and for the local characterisation of regions of teeth that suffered bacterial attack, mechanical wear, fluoridisation, chemical bleaching, or dental treatment such as laser ablation or drilling.

关键词： biogenic composites teeth nanoindentation hardness X-ray diffraction

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Investigation of the unstable flow phenomenon in a pump turbine

引用

Science China(Physics,Mechanics & Astronomy) 2014年第6期57卷 1119-1127页

作者： YIN JunLian WANG deZhong WALTERS d.keith WEI XianZhu School of Mechanical Engineering Shanghai Jiaotong University department of Mechanical Engineering Mississippi State University State key Laboratory of Hydropower Equipment

Instability of pump turbine with S-shaped curve is characterized by large fluctuations of rotational speed during the transient *** investigating this phenomenon,a numerical model based on the dynamic sliding mesh method(dSSM)is presented and used to numerically solve the 3d transient flow which is characterized by the variable rotation speed of *** method is validated by comparison with measured data for a load rejection process in a prototype pump *** results show that the calculated rotation speed agrees well with the experimental *** on the validated model,simulations were performed for the runaway process using an artificially assumed operating condition under which the unstable rotation speed is expected to *** results confirm that the instability of runner rotational speed can be effectively captured with the proposed *** results include the time history profiles of unit flow rate and unit rotating *** internal flow characteristics in a typical unstable period are discussed in detail and the mechanism of the unstable hydraulic phenomenon is ***,the results suggest that the method presented here can be a viable alternative to predict the dynamic characteristics of pump turbines during transient processes.

关键词： pump turbine transient process dynamic sliding mesh flow stability

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

ROBUSTNESS OF EQUILIBRIA IN THE GRAPH MOdEL FOR CONFLICT RESOLUTION

引用

Journal of Systems Science and Systems Engineering 2015年第4期24卷 450-465页

作者： Yasser T.Matbouli d.Marc kilgour keith W.Hipel department of Industrial Engineering King Abdulaziz University department of Systems design Engineering University of Waterloo department of Mathematics Wilfrid Laurier University Centre for International Governance Innovation(CIGI)

A novel approach for assessing the robustness of an equilibrium in conflict resolution is presented. Roughly, an equilibrium is robust if it is resilient, or resistant to deviation. Robustness assessment is based on a new concept called Level of Freedom, which evaluates the relative freedom of a decision maker to escape an equilibrium. Resolutions of a conflict can be affected by changes in decision makers＇ preferences, which may destabilize an equilibrium, causing the conflict to evolve. Hence, a conflict may become long-term and thereby continue to evolve, even after reaching an equilibrium. The new robustness measure is used to rank equilibria based on robustness, to facilitate distinguishing equiiibria that are relatively sustainable. An absolutely robust equilibrium is a special case in which the level of freedom is at an absolute minimum for each individual stability definition.

关键词： Robustness equilibria level of freedom conflict evolution graph model

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：