2,930 research outputs found
A New Low Radiation Wireless Transmission System in Mobile Phone Application Based on Magnetic Resonant Coupling
published_or_final_versio
Numerical Investigation of Magnetic Resonant Coupling Technique in Inter-Chip Communication via Electromagnetics-TCAD Coupled Simulation
published_or_final_versio
A New Low Radiation Wireless Transmission System in Mobile Phone Application Based on Magnetic Resonant Coupling
published_or_final_versio
To the Dolls' House: Children's Reading and Playing in Victorian and Edwardian England
This thesis explores the construction of upper- and middle-class children as readers and consumers in Victorian and Edwardian England, a period which witnessed the Golden Age of children’s literature and major reforms in education. Through the examination of dolls’ house play and representations of dolls’ houses in English children’s literature from the 1860s to the 1920s, as well as autobiographical accounts of childhood reading and playing in adult women’s memoirs, this thesis engages with recent scholarship on children’s literature, material culture and gender to demonstrate the relevance of dolls’ house play to children’s everyday life and their roles as readers, players, and consumers. The first part of the thesis gives an overview of dolls’ houses in history, looking at dolls’ houses in museum collections throughout Europe, from the seventeenth-century Nuremberg houses to Queen Mary’s dolls’ house now on display at Windsor Castle. Part Two examines dolls’ house play as represented in and inspired by children’s books and children’s reading practices. Drawing from children’s magazines, toy-making guides, and picture books featuring dolls’ house making, furnishing, and playing, I argue that playing with dolls’ houses and making their own toys enabled children to balance work and play, labour and leisure. I also show how dolls’ house play was important in the period’s development of pedagogical theories, of a children’s book and toy market, and in the construction of children as consumers. Part Three explores works by Edith Nesbit, Beatrix Potter, and Frances Hodgson Burnett, alongside other non-canonical children’s fiction that makes the dolls’ house a setting for fantasies about miniature worlds. I discuss the dolls’ house as a perfect domestic household in miniature and an enchanting miniaturised spectacle and argue that imagination and play contribute to girls’ learning and negotiating with domestic roles and domestic space
The effect of the support on the surface composition of PtCu alloy nanocatalysts: In situ XPS and HS-LEIS studies
Pt是一类高效、稳定的催化剂, 但Pt资源短缺且价格昂贵, 限制了其广泛商业化应用. 合金化可以使Pt的用量大为减少,; 且往往能显著提高其催化性能, 因而广泛应用于多相催化和电催化. 其中PtCu合金是一类很有前景的催化剂, Cu资源丰富、价格低廉,; 不仅降低了成本, 而且由于合金效应提高了催化剂的活性和稳定性. 由于合金的粒径、形状、组成及结构是影响其催化性能的重要因素,; 目前研究大多关注这些特征的可控合成.然而, 大多工业金属催化剂都是负载于氧化物上以提高催化性能,; 合金纳米粒子的形貌以及表面组成因与载体作用而发生改变, 也就是所谓的载体效应. 这体现在金属/氧化物界面处,; 能够促进金属粒子分散、改变其形貌甚至化学态、进而改变其催化性能, 其中最具代表性的金属-载体强相互作用. 因此,; 研究不同氧化物载体上合金催化剂的分散度、表面组成、化学态, 特别是不同气氛的影响, 对明确影响催化剂性能的关键控制因素非常重要.; 但是由于多相催化剂的复杂性, 且表面灵敏的测试手段很少, 目前相关报道还不多.; 近年发展起来的高灵敏度低能离子散射谱(HS-LEIS)是表面层灵敏的测试技术,; 可以测定最表面层的组成和含量.本文采用溶剂热共还原法成功制备了均一单相、粒径分布较窄的PtCu_x合金纳米颗粒,; 并运用浸渍法将其负载在TiO_2载体上, 以保证载体上纳米粒子组成的均一性.; 应用准原位X-射线光电子能谱(XPS)和高HS-LEIS对负载的PtCu合金纳米催化剂在不同条件处理后的表面组成和化学状态进行表征,; 发现催化剂的表面组成、分布、形貌和化学状态显著受到载体和处理条件的影响, 同时得到负载和未负载的催化剂表面组成与体相组成关系的相图. 结果表明,; PtCu_x/TiO_2催化剂在连续氧化过程中, Cu被氧化并较好在载体表面铺展, Pt-Cu合金状态被破坏,; Pt可能主要形成单一金属的纳米粒子, 并在界面处形成Ptd+. 在连续还原过程中, 部分被还原的Cu, 与Pt形成富Pt合金粒子.; 催化剂表面层主要是Cu, Pt很少, 与体相组成有很大差别, 说明载体对Cu的分散起到重要作用.Supported PtCu alloys have been broadly applied in heterogeneous catalysis and electrocatalysis owing to their excellent catalytic performance and high CO tolerance. It is important to analyze the outermost surface composition of the supported alloy nanoparticles to understand the nature of the catalytically active sites. In this paper, homogeneous face-centered cubic PtCu nanoparticles with a narrow particle size distribution were successfully fabricated and dispersed on a high-surface-area TiO2 powder support. The samples were oxidized and reduced in situ and then introduced into the ultrahigh vacuum chamber to measure the topmost surface composition by high-sensitivity low-energy ion scattering spectroscopy, and to determine the oxidation states of the elements by X-ray photoelectron spectroscopy. The surface composition and morphology, elemental distribution, and oxidation states of the components were found to be significantly affected by the support and treatment conditions. The PtCu is de-alloyed upon oxidation with CuO wetting on the TiO2 surface and re-alloyed upon reduction. Phase diagrams of the surface composition and the bulk composition were plotted and compared for the supported and unsupported materials. (C) 2017, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.National Basic Research Program of China (973 Program) [2013CB933102];; National Natural Science Foundation of China [21273178, 21573180,; 91545204]; Xiamen-Zhuoyue Biomass Energy Co. Ltd
Identification of Cellular Targets of MicroRNA-181a in HepG2 Cells: A New Approach for Functional Analysis of MicroRNAs
<div><p>MicroRNAs (miRNAs) are known to play a part in regulating important cellular processes. They generally perform their regulatory function through their binding with mRNAs, ultimately leading to a repression of target protein expression levels. However, their roles in cellular processes are poorly understood due to the limited understanding of their specific cellular targets. Aberrant levels of miRNAs have been found in hepatocellular carcinoma (HCC) including miR-181a. Using bioinformatics analysis, cyclin-dependent kinase inhibitor 1B (CDKN1β) and transcriptional factor E2F7 were identified as potential targets of miR-181a. Validation analysis using surface plasmon resonance (SPR) showed a positive binding between miR-181a and the 3’UTRs of these two potential mRNA targets. <i>In vivo</i> luciferase assay further confirmed the positive miR-181a:mRNA bindings, where a significant decrease in luciferase activity was detected when HepG2 cells were co-transfected with the 3’UTR-containing reporter plasmids and miR-181a. The potential impact of miR-181a binding to its specific targets on the general cellular behavior was further investigated. Results showed that miR-181a significantly activated the MAPK/JNK pathway which regulates cell proliferation, supporting our recently reported findings. Inhibition of miR-181a, on the other hand, abolished the observed activation. Our findings open up a new approach in designing targeted functional analysis of miRNAs in cellular processes, through the identification of their cellular targets.</p></div
Biological impacts of 'hot-spot' mutations of hepatitis B virus X proteins are genotype B and C differentiated
AIM: To investigate the biological impacts of “hot-spot” mutations on genotype B and C HBV X proteins (HBx).
METHODS: Five types of “hot-spot” mutations of genotype B or C HBV X genes, which sequentially lead to the amino acid substitutions of HBx as I127T, F132Y, K130M+V131I, I127T+K130M+V131I, or K130M+V131I+F132Y, respectively, were generated by means of site-directed mutagenesis. To evaluate the anti-proliferative effects, HBx or related mutants’ expression vectors were transfected separately to the Chang cells by lipofectamine, and the cells were cultured in hygromycin selective medium for 14 d, drug-resistant colonies were fixed with cold methanol, stained with Giemsa dyes and scored (increase of the colonies indicated the reduction of the anti-proliferation activity, and vice versa). Different types of HBx expression vectors were co-transfected separately with the reporter plasmid pCMVβ to Chang cells, which were lysed 48 h post-transfection and the intra-cellular β-galactosidase activities were monitored (increase of the β-galactosidase activities indicated the reduction of the transactivation activity, and vice versa). All data obtained were calculated by paired-samples t-test.
RESULTS: As compared to standard genotype B HBx, mutants of I127T and I127T+K130M+V131I showed higher transactivation and anti-proliferative activities, while the mutants of F132Y, K130M+V131I, and K130M+V131I+F132Y showed lower activities. As compared to standard genotype C HBx, I127T mutant showed higher transactivation activity, while the other four types of mutants showed no differences. With regard to anti-proliferative activity, compared to standard genotype C HBx, F132Y and K130M+V131I mutants showed lower activities, and K130M+V131I +F132Y mutant, on the other hand, showed higher activity, while the mutants of I127T and I127T+K130M+V131I showed no differences.
CONCLUSION: “Hot-spot” mutations affect the anti-proliferation and transactivation activities of genotype B and/or C HBx, and the biological impacts of most “hot-spot” mutations on HBx are genotype B and C differentiated.published_or_final_versio
Assessment of median nerve mobility by ultrasound dynamic imaging in carpal tunnel syndrome diagnosis
2013 Joint UffC, EFTF and PFM SymposiumCarpal tunnel syndrome (CTS) is a common entrapment neuropathy. Nerve conduction studies (NCS) have been used as a standard for CTS diagnosis. Complementing NCS, ultrasound imaging provides anatomic information on pathologic changes of the median nerve, such as the reduced median nerve mobility. Motion of median nerve is dependent on mechanical characteristics, and body movements. The purpose of this study was therefore to measure transverse sliding patterns of the median nerve during fingers flexion and extension in ultrasound B-mode images for distinguishing healthy from CTS subjects, and to investigate any correlation between NCS severity and median nerve motion. Transverse ultrasound images were acquired from 19 normal, 15 mild, and 10 severe CTS subjects confirmed by NCS. In two-second acquisition, their fingers were initially in natural position; the median nerve was then moved toward the ulnar side and radius side in fingers flexion and extension, respectively. The displacements of the median nerve were calculated by the multilevel block-matching pyramid algorithm and averaged. All the average displacements at different acquisition times were then accumulated to obtain cumulative displacements, which were curve-fitted by polynomial function. To differentiate the normal from CTS cases, the R-squared, curvature, and amplitude of the fitted curves were computed, to evaluate the goodness, variation, and maximum value of the fit, respectively. Compared to the CTS patients, the normal subjects had higher R-square, curvature, and amplitude estimates. The three parameters were then inputted to a fuzzy c-means algorithm to classify normal cases and CTS ones. The diagnostic efficiency had an accuracy of 93.2%, a specificity of 100%, and a sensitivity of 88%. Further study includes measuring mechanical strain and stress at different neural sites to provide elasticity of the median nerve. © 2013 IEEE.published_or_final_versio
Clinical characteristics and therapeutic outcomes of nosocomial super-infection in adult bacterial meningitis
<p>Abstract</p> <p>Background</p> <p>Super-infection in adult bacterial meningitis (ABM) is a condition wherein the cerebrospinal fluid (CSF) grows new pathogen(s) during the therapeutic course of meningitis. It is an uncommon but clinically important condition rarely examined in literature.</p> <p>Methods</p> <p>Twenty-seven episodes of super-infection states in 21 ABM patients collected in a 9.5-year study period (January 2001 to June 2010) were evaluated. The clinical characteristics, implicated pathogens, results of antimicrobial susceptibility tests, and therapeutic outcomes were analyzed.</p> <p>Results</p> <p>Twenty-one patients (13 men, 8 women) aged 25-73 years (median, 45 years) had post-neurosurgical state as the preceding event and nosocomial infection. The post-neurosurgical states included spontaneous intracranial hemorrhage (ICH) with craniectomy or craniotomy with extra-ventricular drainage (EVD) or ventriculo-peritoneal shunt (VPS) in 10 patients, traumatic ICH with craniectomy or craniotomy with EVD or VPS in 6 patients, hydrocephalus s/p VPS in 2 patients, and one patient each with cerebral infarct s/p craniectomy with EVD, meningeal metastasis s/p Omaya implant, and head injury. All 21 patients had EVD and/or VP shunt and/or Omaya implant during the whole course of ABM. Recurrent fever was the most common presentation and the implicated bacterial pathogens were protean, many of which were antibiotic resistant. Most patients required adjustment of antibiotics after the pathogens were identified but even with antimicrobial therapy, 33.3% (7/21) died. Morbidity was also high among survivors.</p> <p>Conclusions</p> <p>Super-infection in ABM is usually seen in patients with preceding neurosurgical event, especially insertion of an external drainage device. Repeat CSF culture is mandatory for diagnostic confirmation because most of the implicated bacterial strains are non-susceptible to common antibiotics used. Unusual pathogens like anaerobic bacteria and fungi may also appear. Despite antimicrobial therapy, prognosis remains poor.</p
Elastic differential evolution for automatic data clustering
In many practical applications, it is crucial to perform automatic data clustering without knowing the number of clusters in advance. The evolutionary computation paradigm is good at dealing with this task, but the existing algorithms encounter several deficiencies, such as the encoding redundancy and the cross-dimension learning error. In this article, we propose a novel elastic differential evolution algorithm to solve automatic data clustering. Unlike traditional methods, the proposed algorithm considers each clustering layout as a whole and adapts the cluster number and cluster centroids inherently through the variable-length encoding and the evolution operators. The encoding scheme contains no redundancy. To enable the individuals of different lengths to exchange information properly, we develop a subspace crossover and a two-phase mutation operator. The operators employ the basic method of differential evolution and, in addition, they consider the spatial information of cluster layouts to generate offspring solutions. Particularly, each dimension of the parameter vector interacts with its correlated dimensions, which not only adapts the cluster number but also avoids the cross-dimension learning error. The experimental results show that our algorithm outperforms the state-of-the-art algorithms that it is able to identify the correct number of clusters and obtain a good cluster validation value
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