1,217 research outputs found

    Visualizing the hotspots and emerging trends of 3D printing through scientometrics

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    Purpose - 3D printing is believed to be driving the third industrial revolution. A comprehensive understanding of the hotspots and trends of 3D printing may promote the theory development of 3D printing, help researchers to determine the research direction, and provide a reference for enterprises and government to plan the development of 3D printing industry. However, a scientometric visualizing of 3D printing research and an exploration its hotspots and emerging trends are lacking. Therefore, it was necessary to carry out this relevant research. Design/methodology/approach – Based on the theory of scientometrics, 2769 literatures on the 3D printing theme were found in the Web of Science Core Collection’ SCI indexes between 1995-2016. These were analyzed to explore the research hotspots and emerging trends of 3D printing with the software CiteSpaceIII. Findings – (1) hotspots appeared first in 1993, grow rapidly from 2005, and peaked in 2013; (2) hotspots in the "medical field" appeared earliest and have remained extremely active; (3) hotspots have evolved from “drug”, "printer", "rapid prototyping" and "3D printing" in the 1990s, through "laser-induced consolidation", "scaffolds", "sintering" and "metal matrix composites" in the 2000s, to the current hotspots of "stereolithography", "laser additive manufacturing", "medical images", etc.; (4) "3D bioprinting",“titanium”, “stem cell” and "chemical reaction" were the emerging hotspots in recent years; (5) "commercial operation" and "fusion with emerging technology such as big data" may create future hotspots. Research limitations/implications - It is hard to avoid the possibility of missing important research results on 3D printing. The relevant records could be missing if the query phrases for topic search do not appear in records. Besides, in order to improve the quality of data, this study selected articles and reviews as the research objects, which may also omit some records. Originality/value - First, this is the first paper visualizing the hotspots and emerging trends of 3D printing using scientometric tools. Second, not only "burst reference" and "burst keywords", but also "cluster" and "landmark article" are also selected as the evaluation factors to judge the hotspots and trends of a domain comprehensively. Third, overall perspective of hotspots and trends of 3D printing is put forward for the first time

    Cannabinoids help to unravel etiological aspects in common and bring hope for the treatment of autism and epilepsy

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    Desde 1843 que as propriedades anticonvulsivantes da Cannabis sĂŁo conhecidas pela ciĂȘncia ocidental. Em 1980, ensaios clĂ­nicos demonstraram que canabidiol possui atividade antiepilĂ©tica em pacientes de epilepsia refratĂĄria, sendo sonolĂȘncia o Ășnico efeito colateral. O embargo imposto pela proibição do uso medicinal da Cannabis, no entanto, prejudicou imensamente o desenvolvimento cientĂ­fico e a exploração dessas propriedades. Multiplicam-se, contudo, os casos bem sucedidos de uso ilegal e sem orientação para o tratamento de sĂ­ndromes caracterizadas por epilepsia e autismo regressivo. Os resultados corroboram evidĂȘncias cientĂ­ficas que indicam a existĂȘncia de processos etiolĂłgicos comuns entre o autismo e a epilepsia. Estudos em modelos animais confirmam envolvimento do sistema endocanabinoide. Esses avanços apontam o inĂ­cio de uma revolução no entendimento e tratamento desses transtornos.Since 1843 the anticonvulsant properties of Cannabis are known by the Western science. In 1980, clinical trials have shown that cannabidiol has antiepileptic activity in refractory epilepsy patients, with drowsiness as the only side effect. The embargo imposed by banning medicinal Cannabis use, however, harmed scientific development and the exploration of these properties. However, there is a growing number of successful cases of illegal use without guidance for the treatment of syndromes characterized by epilepsy and regressive autism. The results corroborate scientific evidence that indicates the existence of common etiological aspects between autism and epilepsy. Studies in animal models have confirmed involvement of the endocannabinoid system. These advances indicate the beginning of a revolution in the understanding and treatment of these disorders

    Collaborative mental health care : changing the landscape of mental health care?

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    In this thesis two major changes in the organization of mental health care delivery are explored. The first is collaborative mental health care in primary care, developed as an alternative way to treat common mental health disorders compared to the traditional referral and treatment practice. The collaborative care program followed the principles of stepped care. The first and least intensive treatment step was provided within the collaborative care program in the primary care setting. Treatment intensity was only stepped up through referral to specialized mental health care for patients who did not sufficiently respond to the first step. The traditional practice was direct referral and treatment within specialized care. In several studies we investigated effectiveness, short- and long-term efficiency, cost-effectiveness and whether the stepped care approach was appropriate for all patients instead of the matched care approach. The second change was the integration of eHealth in the collaborative care treatment model. In this study, implementation factors that could either inhibit or promote the uptake and utilization of blended collaborative care by mental health professionals and patients were assessed

    Kenya: West Kenya postmarks

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    HiWATER: The Multi-Scale Observation Experiment on Evapotranspiration over heterogeneous land surfaces (MUSOEXE) Dataset - Flux Observation Matrix (stable isotopic observations

    The time-depth of Corded Ware burial landscapes: A comparative study of Single Grave and Battle Axe burial alignments in Denmark, The Netherlands and Sweden

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    Barrow landscapes appeared in the third and second millennia BC throughout North-Western Europe; these first barrows were constructed by people of the Corded Ware culture and placed in alignments. This thesis is an interregional comparative study, to determine whether there is a pattern in the time-depths of the burial alignments of Trehuse-Sjþrup-Dollerup in Denmark, Angelso-Emmerhout in The Netherlands and Lilla Beddinge in Sweden. The analysis is conducted by means of a literature study and the application of typochronologies. In recent research, the Corded Ware ‘culture’ is still seen as a widespread, unified social phenomenon that is the result of migration, but more emphasis is placed on the regional variability of this phenomenon. Regional variability is also what we see in the three case-studies; in fact, perhaps one may better speak of ‘local variability’, as each case-study reveals a remarkable variety even within one alignment. Even though there do seem to be interregionally shared traits, these are expressed in local practices. Despite the limitations of establishing a time-depth by means of typochronologies, all three alignments reveal a long use-life; even in the Bronze and Iron Ages, prehistoric people buried their dead here. Temporality seems to have been an important aspect of the ‘Corded Ware’ burial landscape

    High Density Frequency Patterns and Phase Mapping in Human Persistent Atrial Fibrillation

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    Atrial fibrillation (AF) is the most common cardiac arrhythmia in clinical practice, and it increases the chance of stroke fivefold. The mechanisms underlying the initiation and preparation of AF are still not clearly understood. Dominant frequency (DF) analysis has been widely used as a feature for the analysis of atrial electrograms. Atrial regions that contain high DF (HDF) signals are believed to correspond to the underlying AF drivers. HDF sites have been proven largely unstable in time and space. However, cyclic behaviours of HDF reappearance were noticed in the LA during persAF, suggesting that AF is not totally random. Similarly, re-entrant activity, also known as ‘rotors’ or spiral waves, have been shown to exist in atrial arrhythmias, and are believed to drive AF. Recently, drifting and unstable rotor behaviours were observed in persAF. The current work aims to develop techniques and tools to better track important features, especially when they are spatiotemporal unstable, such as HDF and phase singularities (PSs), to study the underlying AF mechanisms. In this work, a novel interactive graphic user interface was implemented, compatible with a commercial electro-anatomical mapping system (EnSite, St Jude Medical), providing additional features that are not currently available in commercial systems, to guide catheter ablation of persAF. In addition, a new algorithm has been developed to identify reappearing HDF patterns, and these recurring patterns showed high organisation, which could be important atrial sites for ablation. This is the first algorithm that could track recurrent patterns in DF analysis. Lastly, the performance of state-of-art PS detection methods was firstly investigated in non-contact mapping, suggesting that PS detection are method-dependent. Optimised parameters of the methods were proposed to increase detection accuracy for PSs detection in AF

    Essays in Behavioral and Computational Finance

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    This thesis consists of two essays on behavioral finance and financial market microstructure with computational approaches. Chapter 2 investigates the effects of steroid hormones and trader composition on financial markets in a mathematical model. We focus on the composition of traders in financial markets, namely, female traders and male traders, as risk preferences change in different ways with the mediation of steroid hormones. Firstly, we examine the effects of testosterone on financial risk preferences and market stability in the model. The results from simulation show that the effects of a more balanced gender composition are more nuanced. An increase in the proportion of female traders may actually increase the volatility of returns; however, the chances of extreme events are reduced. Secondly, we analyze the effects of cortisol on traders' risk preference and market behavior in our model with traders' risk preferences influenced by market uncertainty via the mediation of cortisol. Results from our model show that concerns about heightened market uncertainty mitigate traders' excessive risk-taking behaviors and performance of traders is largely affected by market sentiment. In the third part of Chapter 2, we examine the overall effect of testosterone and cortisol on market behavior with traders having heterogeneous behavioral and physiological responses to trading outcomes and market uncertainty. Results from simulation show that male-dominated market is less volatile as the effect of concerns about market uncertainty outweighs the effect of trading outcomes on traders' behavior. Chapter 3 examines the impact of two different types of information on high frequency market microstructure. We present a dynamic trading game in the limit order market with computerized traders and human traders trading in one risky asset, where traders might have lags in observing the contemporaneous fundamental value and the order book status. Optimal strategies and market characteristics are determined through a unique numerical technique. Our results show that these two types of information have different values for traders with information on contemporaneous fundamental value being more valuable than the information on contemporaneous limit order book status

    Enantioselective Vinylogous Michael–Michael Cascade Reactions of 3‑Alkylidene Oxindoles and Nitroolefin Enoates

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    A novel bifunctional squaramide catalyzed vinylogous Michael–Michael cascade reaction of 3-alkylidene oxindoles with nitroolefin enoates was developed. This convenient, one-pot cascade reaction serves as a powerful tool for the enantioselective construction of potential bioactive chiral chromans, which have three continuous tertiary stereocenters, in moderate to good yields (up to 85%) with excellent stereoselectivities (up to >19:1 dr and >99% ee)

    Molecular Dynamics Simulations Using a Capacitance–Polarizability Force Field

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    We present molecular dynamics (MD) simulations using a capacitance–polarizability force field. This force field allows an atomistic description of charge migration within a particle and hence the image charge effects at the interface of such a particle. By employing atomic capacitance and polarizability as the key parameters that describe fluctuating charges and dipoles, we can thus explore the effect of charge migration on the structural dynamics. We illustrate the method by exploring gold nanoparticles in aqueous solutions and compare with previous simulation work. We reach the conclusion that the capacitance–polarizability force field MD method serves as a promising tool for simulating gold–water systems, indicating probable extensions to other metal solutions and for studies of more complicated systems provided that a proper parametrization of the capacitance force field can be made. For the particular system studied, it is found that the water molecules interact with the surface through oxygen atoms, leading to more hydrogen-bond donors than acceptors at the gold–water interface. A prominent shoulder peak is found in the radial distribution of oxygen atoms with respect to the gold surface, due to the fact that the oxygen atoms adsorbed at the on-top sites of the gold nanoparticle. The surface of the aqueous gold nanoparticle carries negative charge, which is balanced by the positive charge in the second outermost layer

    MicroRNAs expression profile of C4-2B cells with/without metformin treatment

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    <p>MicroRNA array was performed with total RNA from C4-2B cells (n=3) treated with or without metformin (final concentration=5 mM) for 48h.</p
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