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1.
Although there are challenges in delivering a quality improvement initiative at academic medical centers, the potential benefits to resident physicians‐in‐training, hospitals, and patients are significant. This article describes the effects of an institution‐wide effort. Resident physicians‐in‐training from four medical specialty programs partnered with hospital staff while working on team quality‐improvement projects. We tracked clinical outcomes and used validated assessments. The results showed improvements in learning and organizational culture.  相似文献   
2.
We have developed a method for studying cellular adhesion by using a custom-designed microfluidic device with parallel non-connected tapered channels. The design enables investigation of cellular responses to a large range of shear stress (ratio of 25) with a single input flow-rate. For each shear stress, a large number of cells are analyzed (500–1500 cells), providing statistically relevant data within a single experiment. Besides adhesion strength measurements, the microsystem presented in this paper enables in-depth analysis of cell detachment kinetics by real-time videomicroscopy. It offers the possibility to analyze adhesion-associated processes, such as migration or cell shape change, within the same experiment. To show the versatility of our device, we examined quantitatively cell adhesion by analyzing kinetics, adhesive strength and migration behaviour or cell shape modifications of the unicellular model cell organism Dictyostelium discoideum at 21 °C and of the human breast cancer cell line MDA-MB-231 at 37 °C. For both cell types, we found that the threshold stresses, which are necessary to detach the cells, follow lognormal distributions, and that the detachment process follows first order kinetics. In addition, for particular conditions’ cells are found to exhibit similar adhesion threshold stresses, but very different detachment kinetics, revealing the importance of dynamics analysis to fully describe cell adhesion. With its rapid implementation and potential for parallel sample processing, such microsystem offers a highly controllable platform for exploring cell adhesion characteristics in a large set of environmental conditions and cell types, and could have wide applications across cell biology, tissue engineering, and cell screening.  相似文献   
3.
We propose using activity theory as a basis for designing and reporting on research projects that focus on information and communication technology (ICT) as a means to support educational processes. Adopting the theory, we describe teaching/learning activities mediated by ICT using a three level analysis: epistemological, methodological, social assistance. The analysis has been applied to the design and reporting of projects in both mathematics education at primary school level and training in technical innovation in commercial enterprises.  相似文献   
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5.
Enrichment of rare cell populations such as Circulating Tumor Cells (CTCs) is a critical step before performing analysis. This paper presents a polymeric microfluidic device with integrated thick Carbon-PolyDimethylSiloxane composite (C-PDMS) electrodes designed to carry out dielectrophoretic (DEP) trapping of low abundance biological cells. Such conductive composite material presents advantages over metallic structures. Indeed, as it combines properties of both the matrix and doping particles, C-PDMS allows the easy and fast integration of conductive microstructures using a soft-lithography approach while preserving O2 plasma bonding properties of PDMS substrate and avoiding a cumbersome alignment procedure. Here, we first performed numerical simulations to demonstrate the advantage of such thick C-PDMS electrodes over a coplanar electrode configuration. It is well established that dielectrophoretic force (FDEP) decreases quickly as the distance from the electrode surface increases resulting in coplanar configuration to a low trapping efficiency at high flow rate. Here, we showed quantitatively that by using electrodes as thick as a microchannel height, it is possible to extend the DEP force influence in the whole volume of the channel compared to coplanar electrode configuration and maintaining high trapping efficiency while increasing the throughput. This model was then used to numerically optimize a thick C-PDMS electrode configuration in terms of trapping efficiency. Then, optimized microfluidic configurations were fabricated and tested at various flow rates for the trapping of MDA-MB-231 breast cancer cell line. We reached trapping efficiencies of 97% at 20 μl/h and 78.7% at 80 μl/h, for 100 μm thick electrodes. Finally, we applied our device to the separation and localized trapping of CTCs (MDA-MB-231) from a red blood cells sample (concentration ratio of 1:10).  相似文献   
6.
Italy was behind the European average in internet development for many years, but a new trend, which has brought considerable change, emerged at the end of 1998 and showed its effects in 2000 and following years. Now Italy is one of the top ten countries worldwide in internet hostcount and the fourth largest in Europe. Density of internet activity on Italy in proportion to population is still below the average in the European Union, but growing faster than Germany, the UK and France--and faster than the world-wide or European average. From the point of view of media control there are several problems. Italy has democratic institutions and freedom of speech, but there is an alarming concentration in the control of mainstream media (especially broadcast). There are no officially declared restrictions in the use of the internet, but several legal and regulatory decisions reveal a desire to limit freedom of opinion and dialogue--and-or gain centralized control of the net.  相似文献   
7.
Abstract

Education conceives itself as something that cannot end. Pedagogy talks of lifelong learning and teachers would never say that their work is finished just because students graduate. But education must also be planned and must therefore rely on organizations (schools, universities). On this level, education can distinguish between different school levels, between thresholds pupils have to overcome, between before and after, and can name its outcomes (qualifications and titles) – all this depending on the given historical and social context. The contingency of its organizational forms is opposed to the universal necessity of education. The article advances the hypothesis that this contrast is ‘hidden’ by the idea of ‘reform’: the frequency and quantity of organizational changes affecting modern educational institutions has therefore the function of reconciling an endless education with the finiteness of its concrete forms.  相似文献   
8.
ABSTRACT

The first step in preservative measures for artworks in airtight showcases is the exclusion of outgassing from construction materials or, at least, limitation of the emissions to a minimum acceptable level if the volatile organic compounds (VOCs) generated may be qualified as harmless. Once it is ascertained that the objects in the showcases are responsible for VOC emissions, a step forward becomes necessary, implying showcase ventilation with air flowing through active sorbent materials. Solid phase micro-extraction (SPME) followed by GC separation and MS identification has been applied for checking the outgassing characteristics of different types of materials used for the construction of airtight showcases, and the method was found particularly attractive in terms of speed and sensitivity, suitable for measurements in presence of low-emitting materials. Sampling could also be done in the case interiors, thus making possible detection and recognition of emissions from art objects within a case. A comprehensive preventive conservation scheme has been further devised by means of active air circulation within the showcase and functional sorbent materials along the flow, for complete suppression of gaseous compounds. Control of the compounds in the air flow and of their filtration efficacy was achieved by direct sampling, also using SPME fibers. Continuous monitoring of the air quality in the showcases has been developed with insertion of a photoionization detector capable of detecting the VOCs in the air by inducing molecular ionization, and measuring the generated photocurrent. The system is not selective, but gives the total concentration, reaching ppb sensitivity with high-quality data. In addition it includes temperature and humidity sensors, making the whole a useful instrument for environment control.  相似文献   
9.
This paper looks at eight comparative case-studies on academic entrepreneurs in life sciences conducted in Europe in 2008. The interviewees were selected from the KEINS database that lists all academic inventors from Italy, France, Sweden and the Netherlands who have one or more patent applications registered at the European Patent Office, 1978–2004. The case-studies show that institutions largely influence the way in which scientists are coping with the normative uncertainty typical of science and technology systemic boundaries in the life sciences today. By exploring new local solutions, the entrepreneurial achievements of scientists are also establishing new institutional practices. Our empirical analysis helps to reconsider traditional dichotomies in the sociological, economic and institutional literature, such as publications versus patents and academia versus industry, and to illustrate the creative role of academic entrepreneurs.  相似文献   
10.
This paper reports the use of a recent composite material, noted hereafter i-PDMS, made of carbonyl iron microparticles mixed in a PolyDiMethylSiloxane (PDMS) matrix, for magnetophoretic functions such as capture and separation of magnetic species. We demonstrated that this composite which combine the advantages of both components, can locally generate high gradients of magnetic field when placed between two permanent magnets. After evaluating the magnetic susceptibility of the material as a function of the doping ratio, we investigated the molding resolution offered by i-PDMS to obtain microstructures of various sizes and shapes. Then, we implemented 500 μm i-PDMS microstructures in a microfluidic channel and studied the influence of flow rate on the deviation and trapping of superparamagnetic beads flowing at the neighborhood of the composite material. We characterized the attraction of the magnetic composite by measuring the distance from the i-PDMS microstructure, at which the beads are either deviated or captured. Finally, we demonstrated the interest of i-PDMS to perform magnetophoretic functions in microsystems for biological applications by performing capture of magnetically labeled cells.  相似文献   
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