Polyester μ-assay chip for stem cell studies     

Francesco Piraino  ?eila Selimovi?  Marco Adamo  Alessandro Pero  Sam Manoucheri  Sang Bok Kim  Danilo Demarchi  Ali Khademhosseini 《Biomicrofluidics》2012,6(4)

The application of microfluidic technologies to stem cell research is of great interest to biologists and bioengineers. This is chiefly due to the intricate ability to control the cellular environment, the reduction of reagent volume, experimentation time and cost, and the high-throughput screening capabilities of microscale devices. Despite this importance, a simple-to-use microfluidic platform for studying the effects of growth factors on stem cell differentiation has not yet emerged. With this consideration, we have designed and characterized a microfluidic device that is easy to fabricate and operate, yet contains several functional elements. Our device is a simple polyester-based microfluidic chip capable of simultaneously screening multiple independent stem cell culture conditions. Generated by laser ablation and stacking of multiple layers of polyester film, this device integrates a 10 × 10 microwell array for cell culture with a continuous perfusion system and a non-linear concentration gradient generator. We performed numerical calculations to predict the gradient formation and calculate the shear stress acting on the cells inside the device. The device operation was validated by culturing murine embryonic stem cells inside the microwells for 5 days. Furthermore, we showed the ability to maintain the pluripotency of stem cell aggregates in response to concentrations of leukemia inhibitory factor ranging from 0 to ∼1000 U/ml. Given its simplicity, fast manufacturing method, scalability, and the cell-compatible nature of the device, it may be a useful platform for long-term stem cell culture and studies.  相似文献   

Skilled migration and innovation in European industries     

Claudio Fassio  Fabio Montobbio  Alessandra Venturini 《Research Policy》2019,48(3):706-718

This paper studies the effects of skilled migration on innovation –proxied by patent citations- in European industries between 1994 and 2005, using the French and the UK Labour Force Surveys and the German Microcensus. Highly-educated migrants have a positive effect on innovation, but the effect differs across industries. It is stronger in industries with low levels of overeducation, high levels of FDIs and openness to trade and, finally, in industries with higher ethnic diversity. The aggregate effect of the skilled immigrant is about one third the one of the skilled natives. We tackle the endogeneity of migrants with a set of external and internal instruments.  相似文献   

Modelling the joint impact of R&D and ICT on productivity: A frontier analysis approach     

Fabio Pieri  Michela Vecchi  Francesco Venturini 《Research Policy》2018,47(9):1842-1852

This study explores the channels through which technological investments affect productivity performance of industrialized economies. Using a Stochastic Frontier Model (SFM) we estimate the productivity effects of R&D and ICT for a large sample of OECD industries between 1973 and 2007, identifying four channels of transmission: input accumulation, technological change, technical efficiency and spillovers. Our results show that ICT has been particularly effective in reducing production inefficiency and in generating inter-industry spillovers, while R&D has raised the rate of technical change and favoured knowledge spillovers within sectors. We also quantify the contribution of technological investments to output and total factor productivity growth documenting that R&D and ICT accounted for almost 95% of productivity growth in the OECD area.  相似文献   

Telecommunications and Transnationalism: The Polarization of Social Space     

Francesco Stolfi  Gerald Sussman 《The Information Society》2001,17(1):49-62

This article critically assesses the policy orientation, social impacts, and linkages of telecommunications in the United States within a government deregulated policy environment and an increasingly globalized economy. Deregulation has been driven by both ideological and technological demands, stemming from several political and economic transformations in the world economy, the collapse of state socialism in eastern Europe and the former Soviet Union, and greater oligopolistic competition among transnational corporations. An expanded infrastructure of new digital information and communications technology (ICT) is the foundation of a worldwide political economic regime of accumulation. ICT increases command and control capabilities of large corporations, together with the mobility and liquidity of capital, making it essential to the restructuring of the world economy, the new international division of labor, and the creation of global "information city" networks. At the same time, government deregulation and rapid technological change are associated with a number of spatial, economic, and social dualisms.  相似文献   

A New Method of Revealing Armourers’ Marks     

Alan Williams  David Edge  Francesco Grazzi  Nikolai Kardjilov 《文物保护研究》2019,64(1):10-15

In this research, we performed radiographic experiments exploiting polychromatic phase-contrast imaging, a method for contrast enhancement in transmitted neutron beams by measuring a sample made with a homogeneous material but exhibiting a different microstructure induced by mechanical actions. We were able to reveal the armourers’ marks now obscured by polishing that are present in these examples of medieval armour.  相似文献   

The impact of virtual simulation tools on problem-solving and new product development organization     

Markus C. Becker  Pasquale Salvatore  Francesco Zirpoli 《Research Policy》2005,34(9):1305-1321

New product development nowadays makes heavy use of IT instruments such as virtual simulation tools. The main motivation for introducing virtual simulation tools in new product development is to speed up development and lower its cost. Virtual simulation tools, however, do much more. They introduce profound changes in the organization, including the nature of problem-solving, bearing the potential to increase new product development performance beyond cost and lead time reduction. Understanding these profound changes, we argue, holds the key to unlocking the potential of virtual simulation tools for improving new product development performance, including more innovative products. We support our argument with a case study from the European auto industry.  相似文献   

Topological interpretation of the inverse connection matrix A^.s_b     

Pasquale Pugliese  Francesco Vacca 《Journal of The Franklin Institute》1976,302(4):367-374

This paper discusses a new algebraic model of electrical networks by which a deeper understanding is achieved of the interrelation existing between a system of independent cut sets and the corresponding system of independent “contours”, in the sense of orthogonal network theory (1).The new model allows, by a redefinition of f-cut sets, to give an interpretation in terms of linear graph theory to the inverse connection matrix A^.s_b, i.e. to the transformation matrix between voltages in the orthogonal and the primitive reference frames, for a general choice of independent contours.Furthermore, a directly algebraic derivation of the voltage transformation is presented, recalling the properties of dual vector spaces and without invoking the principle of invariance of the instantaneous power.  相似文献   

Weighted Word Pairs for query expansion     

Francesco Colace  Massimo De Santo  Luca Greco  Paolo Napoletano 《Information processing & management》2015

This paper proposes a novel query expansion method to improve accuracy of text retrieval systems. Our method makes use of a minimal relevance feedback to expand the initial query with a structured representation composed of weighted pairs of words. Such a structure is obtained from the relevance feedback through a method for pairs of words selection based on the Probabilistic Topic Model. We compared our method with other baseline query expansion schemes and methods. Evaluations performed on TREC-8 demonstrated the effectiveness of the proposed method with respect to the baseline.  相似文献   

A computer science and robotics integration model for primary school: evaluation of a large-scale in-service K-4 teacher-training program     

El-Hamamsy  Laila  Chessel-Lazzarotto  Frédérique  Bruno  Barbara  Roy  Didier  Cahlikova  Tereza  Chevalier  Morgane  Parriaux  Gabriel  Pellet  Jean-Philippe  Lanarès  Jacques  Zufferey  Jessica Dehler  Mondada  Francesco 《Education and Information Technologies》2021,26(3):2445-2475

Education and Information Technologies - Integrating computer science (CS) into school curricula has become a worldwide preoccupation. Therefore, we present a CS and Robotics integration model and...  相似文献   

Knowledge coherence, variety and economic growth: Manufacturing evidence from Italian regions   总被引：2，自引：0，他引：2  

Francesco Quatraro 《Research Policy》2010,39(10):1289-1302

This paper elaborates a view on knowledge as a result of a combinatorial search activity, so as to investigate its effects on economic growth at the regional level. Empirical estimations corroborate the hypothesis that knowledge coherence and variety, besides the traditional measure of knowledge stock, matter in shaping regional economic performances. The check for spatial dependence suggests that cross-regional externalities exert additional triggering effects on growth, without debasing the effects of knowledge properties. Important policy implications stem from the analysis, in that regional innovation strategies should be carefully coordinated so as to reach a higher degree of internal coherence and trigger economic performances.  相似文献