排序方式： 共有64条查询结果，搜索用时 562 毫秒
31.
Carugo D Ankrett DN Glynne-Jones P Capretto L Boltryk RJ Zhang X Townsend PA Hill M 《Biomicrofluidics》2011,5(4):44108-4410815
Sonoporation is a useful biophysical mechanism for facilitating the transmembrane delivery of therapeutic agents from the extracellular to the intracellular milieu. Conventionally, sonoporation is carried out in the presence of ultrasound contrast agents, which are known to greatly enhance transient poration of biological cell membranes. However, in vivo contrast agents have been observed to induce capillary rupture and haemorrhage due to endothelial cell damage and to greatly increase the potential for cell lysis in vitro. Here, we demonstrate sonoporation of cardiac myoblasts in the absence of contrast agent (CA-free sonoporation) using a low-cost ultrasound-microfluidic device. Within this device an ultrasonic standing wave was generated, allowing control over the position of the cells and the strength of the acoustic radiation forces. Real-time single-cell analysis and retrospective post-sonication analysis of insonated cardiac myoblasts showed that CA-free sonoporation induced transmembrane transfer of fluorescent probes (CMFDA and FITC-dextran) and that different mechanisms potentially contribute to membrane poration in the presence of an ultrasonic wave. Additionally, to the best of our knowledge, we have shown for the first time that sonoporation induces increased cell cytotoxicity as a consequence of CA-free ultrasound-facilitated uptake of pharmaceutical agents (doxorubicin, luteolin, and apigenin). The US-microfluidic device designed here provides an in vitro alternative to expensive and controversial in vivo models used for early stage drug discovery, and drug delivery programs and toxicity measurements. 相似文献
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Daniele Broccolo Lorenzo Marcon Franco Maria Nardini Raffaele Perego Fabrizio Silvestri 《Information processing & management》2012
This paper proposes an efficient and effective solution to the problem of choosing the queries to suggest to web search engine users in order to help them in rapidly satisfying their information needs. By exploiting a weak function for assessing the similarity between the current query and the knowledge base built from historical users’ sessions, we re-conduct the suggestion generation phase to the processing of a full-text query over an inverted index. The resulting query recommendation technique is very efficient and scalable, and is less affected by the data-sparsity problem than most state-of-the-art proposals. Thus, it is particularly effective in generating suggestions for rare queries occurring in the long tail of the query popularity distribution. The quality of suggestions generated is assessed by evaluating the effectiveness in forecasting the users’ behavior recorded in historical query logs, and on the basis of the results of a reproducible user study conducted on publicly-available, human-assessed data. The experimental evaluation conducted shows that our proposal remarkably outperforms two other state-of-the-art solutions, and that it can generate useful suggestions even for rare and never seen queries. 相似文献
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This qualitative constructivist research study employed a unique professional case-based pedagogy to investigate how concurrent Education undergraduate students made sense of the complex dilemmas inherent in the cases and in particular, the factors that influenced their critical thinking processes. The paper identifies three core categories that emerged in participants' critical reflections. Further, it discusses the process of participant engagement as they reflected upon the complexities of each case to arrive at new levels of awareness regarding their professional conduct, responsibilities, and behaviour in view of the Standards of Professional Practice. Last, it elaborates upon the progression of participants' thinking processes via this multi-modal approach. 相似文献
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Francesca Boem Lorenzo Sabattini Cristian Secchi 《Journal of The Franklin Institute》2019,356(2):860-882
The paper proposes a decentralized state estimation method for the control of network systems, where a cooperative objective has to be achieved. The nodes of the network are partitioned into independent nodes, providing the control inputs, and dependent nodes, controlled by local interaction laws. The proposed state estimation algorithm allows the independent nodes to estimate the state of the dependent nodes in a completely decentralized way. To do that, it is necessary for each independent node of the network to estimate the control input components computed by the other independent nodes, without requiring communication among the independent nodes. The decentralized state estimator, including an input estimator, is developed and the convergence properties are studied. Simulation results show the effectiveness of the proposed approach. 相似文献
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Matteo Calabrese Nicoletta Odisio Lorenzo Appolonia Andrea Bernagozzi Jean Marc Christille Annie Glarey 《文物保护研究》2018,63(5):43-50
ABSTRACTForecasting the dynamics of alteration in materials, in particular the timescale of degradation, is relevant to preventive conservation, and great deal of effort has gone into developing new models for the kinetics of physical and chemical phenomena affecting materials. Creating monitoring systems able to assess the evolution of degradation processes that inform intervention programs is necessary to ensure the protection of historical and artistic heritage. The Research Unit for Integrated and Predictive Systems (SIP) is presented: it develops new tools and algorithms to study the alteration of materials using non-invasive techniques and passive monitoring, as well as new mathematical models to predict how the surfaces of materials degrade with time. The paper focuses on the Arch of Augustus and presents initial results from two virtual sensors used to ‘monitor’ environmental conditions outdoors. These systems do not need a permanent, invasive network of sensors in situ. They rely instead on local infrastructure for measuring air quality, and adopt smart information fusion algorithms to predict the environment around the cultural heritage site. Virtual sensors can provide an effective control system that highlights specific conditions linked to specific forms of alteration. 相似文献
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Naomi Datson Matthew Weston Barry Drust Warren Gregson Lorenzo Lolli 《Journal of sports sciences》2020,38(11-12):1313-1319
ABSTRACT Talent identification and development programmes have received broad attention in the last decades, yet evidence regarding the predictive utility of physical performance in female soccer players is limited. Using a retrospective design, we appraised the predictive value of performance-related measures in a sample of 228 youth female soccer players previously involved in residential Elite Performance Camps (age range: 12.7–15.3 years). With 10-m sprinting, 30-m sprinting, counter-movement jump height, and Yo-Yo Intermittent Recovery Test Level 1 (IR1) distance as primary predictor variables, the Akaike Information Criterion (AIC) assessed the relative quality of four penalised logistic regression models for determining future competitive international squads U17–U20 level selection. The model including Yo-Yo IR1 was the best for predicting career outcome. Predicted probabilities of future selection to the international squad increased with higher Yo-Yo IR1 distances, from 4.5% (95% confidence interval, 0.8 to 8.2%) for a distance lower than 440 m to 64.7% (95% confidence interval, 47.3 to 82.1%) for a score of 2040 m. The present study highlights the predictive utility of high-intensity endurance capacity for informing career progression in elite youth female soccer and provides reference values for staff involved in the talent development of elite youth female soccer players. 相似文献
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Lorenzo Righetto Alessandro Spelta Emanuele Rabosio Fabio Pammolli 《Journal of Informetrics》2019,13(2):583-592
Within the perimeter of patent collaboration networks, the average distance of collaborations and the number of countries involved per each collaboration have been shown to have increased steadily in time. Less attention, though, has been devoted to assessing whether this growth of cross-country collaborations is stable in time. To address this scientific question we focus on the identification of long-term correlations (i.e. temporal persistence). Our data set consists of time series of yearly average collaboration radii and of cross-border links in the Euro-American subsystem of the global collaboration network for the period 1978–2014. To investigate the fundamental persistence properties of these time series, we use Detrended Fluctuation Analysis, a method that allows us to measure long-term correlations in detrended signals. Also, we devise a general and original procedure to assess the statistical significance of results for short time series. Our results, showing that long-term correlations do exist in the majority of our signals, reinforce the hypothesis of a diminishing role of geographical distance in technological collaborations. Results at national level show that a significant degree of heterogeneity in persistence parameters can be detected within Europe, irrespectively of the efforts towards the set-up of an integrated European Research Area. 相似文献
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Developmental Trajectories of Acculturation: Links With Family Functioning and Mental Health in Recent‐Immigrant Hispanic Adolescents 
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下载免费PDF全文 Seth J. Schwartz Jennifer B. Unger Byron L. Zamboanga David Córdova Craig A. Mason Shi Huang Lourdes Baezconde‐Garbanati Elma I. Lorenzo‐Blanco Sabrina E. Des Rosiers Daniel W. Soto Juan A. Villamar Monica Pattarroyo Karina M. Lizzi José Szapocznik 《Child development》2015,86(3):726-748
The present study was designed to examine acculturative changes, and their effects on mental health and family functioning, in recent‐immigrant Hispanic adolescents. A sample of 302 Hispanic adolescents was assessed five times over a 2½‐year period. Participants completed measures of Hispanic and U.S. practices, collectivist and individualist values, and ethnic and U.S. identity at each time point. Baseline and Time 5 levels of mental health and family functioning were also assessed. Latent class growth analyses produced two‐class solutions for practices, values, and identifications. Adolescents who increased over time in practices and values reported the most adaptive mental health and family functioning. Adolescents who did not change in any acculturation domain reported the least favorable mental health and family functioning. 相似文献