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Objective @# To investigate the effect of micro/nano hierarchical structures on the adhesion and proliferation of MC3T3-E1 cells, evaluate the drug delivery potential of titanium surfaces, and provide a reference for the modification of selected areas of titanium surfaces to enhance drug delivery and slow drug release. @*Methods @# Pure titanium samples (10 mm in diameter and 2.5 mm in thickness) were randomly divided into a polished group (T), anodized group (TO), and micro/nano hierarchical structure group (FTO) according to the surface treatment of the titanium. The T group was polished, the TO group was treated with anodic oxidation technology, and the FTO group was treated by femtosecond laser etching combined with anodic oxidation technology. The three surface morphologies were observed by scanning electron microscopy (SEM), the wettability of the surface was measured by the contact angle, and the surface chemical composition was analyzed by X-ray energy dispersive spectroscopy (EDS). The depth of the FTO structure and the surface roughness were measured by confocal laser scanning microscopy (CLSM). MC3T3-E1 cell adhesion proliferation and differentiation on the surface of each group of samples was assessed by immunofluorescence staining, CCK-8, and semiquantitative analysis of Alizarin staining. A freeze-drying method was applied to load recombinant human bone morphogenetic protein-2 (rhBMP-2), and an enzyme-linked immunosorbent assay (ELISA) was used to assess the drug-loading potential of different surface structures. @* Results@#SEM revealed that the surface of T group titanium plates showed uniform polishing marks in the same direction. The surface of the TO group was a nanoscale honeycomb-like titanium dioxide (TiO2) nanotube structure, and the FTO group formed a regular and ordered micro/nano layered structure. The contact angle of the FTO group was the smallest at 32° ± 1.7°. Its wettability was the best. The average depth of the first-level structure circular pores was 93.6 μm, and the roughness was 1.5-2 μm. The TO and FTO groups contained a high percentage of oxygen, suggesting TiO2 nanotube formation. The FTO group had the most significant surface cell proliferation (P<0.001) and the largest cell adhesion surface area (P<0.05). rhBMP-2 was slowly released for 14 d after loading in the FTO group and promoted extracellular matrix mineralization (P<0.001). @*Conclusion @#Titanium surface microprepared hierarchical structure has the effect of promoting MC3T3-E1 cell adhesion, proliferation, and osteogenic differentiation with drug loading potential, which is a new method of titanium surface treatment.
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The purpose of this paper was to introduce how to reasonably analyze the multiple Logistic regression models in combination with the multilevel model analysis. Firstly， four basic concepts related to the multilevel model analysis were introduced. Secondly， three steps for building a multilevel model were given. Thirdly， through an example of a multicenter drug clinical trial， the whole process of how to use SAS software for the analysis was presented. The contests were as follows： ① testing whether the odds ratios of each center were homogenous； ② building the multiple Logistic regression model after generating dummy variables for the trial center； ③ constructing a multiple Logistic regression model with the trial center as a stratified variable； ④ building a random intercept multilevel multiple Logistic regression model； ⑤ constructing a random intercept and random slope multilevel multiple Logistic regression model. The conclusion was that when there were differences among the data at different hierarchies with binary outcome variables， the most appropriate approach was to build a multilevel multiple Logistic regression model.
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OBJECTIVES@#This study was performed to fabricate a bionic coating with titanium (Ti) phosphate to promote the osseointegration of Ti substrate implants.@*METHODS@#Phosphorylated micro/nanocoating was prepared on the surface of pure titanium (i.e., TiP-Ti) by hydrothermal process under special pressure, and the untreated smooth pure titanium (cp-Ti) was selected as the control. To evaluate the characteristics of the coating surface, scanning electron microscopy, X-ray diffraction, atomic force microscopy, and contact-angle measurement were performed. In addition, the effects of TiP-Ti on the proliferation, adhesion, and differentiation of rat bone marrow mesenchymal stem cells (BMSCs) were investigated by using @*RESULTS@#The TiP-Ti surface presented a bionic structure with coexisting nanoscale 3D spatial structure and microscale pores. @*CONCLUSIONS@#A bionic structure with TiP-Ti micro/nanoscale coating was successfully fabricated, indicating a promising method for modifying the surface of implants.
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Animals , Rats , Dental Implants , Osseointegration , Osteogenesis , Oxides , Phosphates , Surface Properties , TitaniumABSTRACT
Abstract Purpose In the present study, we aimed to integrate unidimensional and multidimensional perspectives of the construct of the fear of personal death (FOPD). It has been assumed that (a) there is one general factor of FOPD, reflecting the unidimensional perspective and that (b) FOPD assumes a hierarchical structure reflecting the multidimensional perspective. Methods We administered the Death and Dying Anxiety Inventory (FVTS, Ochsmann, 1993) to 1217 Polish participants (602 women and 615 men) aged between 18 and 89 ( M Age = 31.13; SD Age = 12.65). Results The results of the bi-factor model of the confirmatory factor analysis proved the existence of a FOPD general factor. Using the bass-ackwards approach, we provided evidence on the hierarchical structure of FOPD, which stresses that specific types of FOPD distinguished in the FVTS, which, on a higher level, make up the factors of threats to self-fulfilling existence, threats to well-being and threats of physical destruction, which in turn depend on the subject's perspective: the physical self and/or the symbolic self. Conclusion The current study demonstrates that unidimensional and multidimensional approaches to FOPD do not necessarily exclude one another. The unidimensional approach to FOPD seems to be most appropriate for studying the intensity of FOPD, while the multidimensional approach seems to be more suitable for studying the individual differences in how people give meaning to FOPD.
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Humans , Male , Female , Adolescent , Adult , Middle Aged , Aged , Aged, 80 and over , Psychometrics , Attitude to Death , Surveys and Questionnaires , Factor Analysis, Statistical , Fear/psychology , PolandABSTRACT
As the main organ of the body, the load-bearing ability of bone is closely connected to its biomechanical properties. Bone is a complex hierarchical biomaterial, whose biomechanical properties are determined by its own structure and biological characteristics. Because of its mechanical adaptability, bone tissues represent different biomechanical properties under different mechanical loading. To quantify the complicated properties of bone and provide an accurate theoretical basis for clinical research, it is necessary to give insight into the biomechanical properties of bone at different levels and the constitutive relationships of bone tissues. In this review, relative researches on constitutive relationships in recent years were summarized based on its hierarchical biomechanical properties.
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As the main organ of the body, the load-bearing ability of bone is closely connected to its biomechanical properties. Bone is a complex hierarchical biomaterial, whose biomechanical properties are determined by its own structure and biological characteristics. Because of its mechanical adaptability, bone tissues represent different biomechanical properties under different mechanical loading. To quantify the complicated properties of bone and provide an accurate theoretical basis for clinical research, it is necessary to give insight into the biomechanical properties of bone at different levels and the constitutive relationships of bone tissues. In this review, relative researches on constitutive relationships in recent years were summarized based on its hierarchical biomechanical properties.
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Cortical bone is a kind of natural biological composite materials, which is mainly composed of tropocollagen molecules and nanoscale hydroxyapatite mineral crystals. It possesses high strength, stiffness and fracture toughness and has the ability to tolerate damage and self-heal. In the long process of evolution, bone tissues form the biomechanical strength and toughness to meet its functional needs. The excellent mechanical properties of cortical bone are closely related to its hierarchical microstructure. This paper reviewed the hierarchical microstructure of cortical bone and its toughening mechanisms, which would contribute to understanding the diagnosis, prevention and treatment of aging-related osteoporosis and the pathological mechanism of bone diseases.
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The facile and efficient synthetic route for Ag dendritic nanostructures on Indium tin oxide ( ITO) via electrodeposition was reported. The results showed that the Raman intensities of rhodamine 6G ( R6G) decreased with decreasing the loading concentration, and even at a low concentration of 10-10 mol/L, the signatures of R6G in Raman spectrum were still clearly observed. It indicated that the Ag dendritic nanostructures exhibited high surface-enhanced Raman scattering ( SERS) sensitivity. Moreover, the relative standard deviation ( RSD ) of band at 610 cm-1 was calculated to be 12 . 1%, 12 . 0%, 11 . 7%, 10 . 9%, 13. 2% and 14. 3%, respectively, corresponding with the concentration of R6G from 10-5 mol/L to 10-10 mol/L, which revealed that the Ag dendritic nanostructures could provide abundant hot spots and exhibited excellent reproducibility. In addition, the SERS spectrum of 3-mercaptopropionic acid (3MPA) also could be detected when its concentration was 10-5 mol/L. This method offers an easy and low-cost way to prepare Ag dendritic substrates and makes SERS detection more practicable.
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Objective:To compare the effect of three different titanium alloy surface topographies on the biological character fibro-blasts.Methods:Three different titanium alloy Ti6Al4V surface topographies were created by machining(M),direct current electro-chemical etching(DC)and alternating current electrochemical etching(AC)respectively,and standard sized samples were prepared. The surface topographies were observed field emission scanning electron microscopy(FE-SEM).Mouse L929 fibroblasts were cultured on different surfaces.The attachment of cells was examined by acridine orange staining and observed under fluorescent microscope.The proliferation of cells was measured using MTT assay.Results:Tubles with the diamete of 5 -20 μm were observed on the surface of the sample of group DC,and more evenly distributed tubles on that of group AC.Micro-sulci were observed and no microtuble was found on the sample surface of group M.L929 cells were attached on the surface of all the samples in the 3 groups.More adhered and better strached cells were observed on AC treated surface.The proliferation of fibroblasts on AC and DC surfaces was superior to that on M treated surface and at the 3 -5 day the proliferation of fibroblasts on the AC surface was higher than that on DC treated surface.Con-clusion:AC treated surface with the micro-submicro-nano hierarchical topography of titanium alloy has a superior biocompatibility and can promote the early attachment and proliferation of the fibroblasts.
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Zinc oxide nanowires were hydrothermally synthesized on the surface of an Au cylindrical spiral formed by manually spiraling an Au fiber around an optical fiber core, glucose oxidase was immobilized on these nanowires by physical adsorption, and then a spirally hierarchical structure-based glucose enzymatic electrode was obtained. The surface morphologies of the spirally hierarchical structures and corresponding enzymatic electrodes were extracted, and the electrochemical performances of the enzymatic electrodes were characterized. It was concluded that the synthesizing parameters of zinc oxide nanowires significantly affected the surface morphologies and glucose oxidase immobilization on the spirally hierarchical structures, and further the performances of related glucose sensors. With Zn2﹢concentration of the growth solution set at 25 mmol/L, the roughness of surface morphology was determined to be 0. 10 μm and correlation length 0. 29 μm, resulting in a better immobilization of glucose oxidase upon zinc oxide nanowires. In this case the sensitivity of the glucose sensor was determined to be 2. 15 μA/(mmol/L·cm2), the linear range was 0-4. 50 mmol/L, the low detection limit was 9. 20 μmol/L and Michaelis-Menten constant was 3. 68 mmol/L. The results not only benefit the batch production of the spirally hierarchical structure-based enzymatic electrodes, but also significantly improve the performances of the glucose sensors.
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Objective To investigate the scale and educational-level composition of nursing education in Guangdong Province,identify the issues in the development process,and provide suggestions accordingly.Methods Data on the scale and education level of nursing education were obtained from the Ministry of Education of China.Results Scale of nursing education at three levels for entering nursing (secondary diploma,advanced diploma,and baccalaureate degree) expanded rapidly during 2006～2010 in Guangdong,with 25.6 thousand recruitments totally in 2010,which as 2.05 times as in 2006.The portion of students recruited in secondary diploma programs had increased gradually,resulted in 83.53％ in 2010 (9.41％ for recruitments in advanced diploma programs and 7.06％ for baccalaureate degree programs).179 and 16 students were recruited in master's and doctoral programs in Guangdong,respectively,during 2006～ 2010.Conclusions The current scale and composition of nursing education in Guangdong should be improved according to the dynamic supply-need relationship of nursing workforce.Initial nursing education should be upgraded by increasing the recruitments of advanced diploma and baccalaureate programs and decreasing the recruitments of secondary diploma programs,expand graduate education,and ensure the quality of education.
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Este estudo tem como objectivo principal a análise da estrutura hierárquica do autoconceito em adolescentes e, adicionalmente, a comparação dessa estrutura em alunos com e sem repetência no seu passado escolar. Participaram no estudo 943 alunos portugueses do 7º, 9º e 11º ano de escolaridade, que responderam a uma escala de autoconceito e de auto-estima. Os resultados obtidos sustentam a ideia de uma organização hierárquica do autoconceito e um modelo que subdivide o autoconceito em quatro factores de ordem superior. Os resultados sugerem, ainda, uma associação entre a dimensão comportamento e diferentes dimensões de ordem superior, nomeadamente as duas dimensões do autoconceito académico e o autoconceito social. Os resultados divergem quando tomamos alunos com maior e menor sucesso escolar, justificando maior atenção na investigação e na intervenção a este aspecto.
The main goal of this research is to analyze the hierarchical structure of self-concept in adolescents and, additionally, to compare this structure in students who have failed in their academic career and in those who have not. Nine hundred and forty-three Portuguese students from the 7th, 9th and 11th grades participated in the research. They completed self-concept and self-esteem scales. Results support the assertion that self-concept is hierarchically structured, and also support a model that subdivides self-concept into four higher order factors. Results also suggest an association between the behavioral dimension and various different higher order dimensions, namely, the two academic self-concept dimensions and the social self-concept one. However, they show divergences when the structure of self-concept between achievers and underachievers is compared. This aspect needs to be examined with greater attention on future researches and interventions.
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Humans , Male , Female , Adolescent , Students/psychology , Self Concept , UnderachievementABSTRACT
Recently, it becomes conspicuous that the network should have enough communication bandwidth and be organized with steadiness to operate and support hospital information system successfully. Seoul National University Hospital completed to reconstruct legacy network which had been used since 1995. We had a consultation to diagnose the current problems and reconstructed the network according to the consultation. The design of network architecture was mainly focused on the circuit route in case of error condition and the suitable bandwidth for the easy communication. We also regulated the use of unsuitable protocols which might broadcast inappropriate data packets over the whole network. After 6 months of operation we evaluated the performance of newly constructed network. The average traffic rate from the input port of main servers was 0.5% and that from the output port was 6% separately. The average traffic rate on the overall ATM backbone showed around 1 %.From the result, we concluded that the newly constructed network had such an enough capability supporting hospital information system without any interruption. Furthermore, we expect that it will be sufficient to support the additional traffic increment by PACS and group ware applications.