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排序方式: 共有133条查询结果,搜索用时 31 毫秒
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Cell isolation in designated regions or from heterogeneous samples is often required for many microfluidic cell-based assays. However, current techniques have either limited throughput or are incapable of viable off-chip collection. We present an innovative approach, allowing high-throughput and label-free cell isolation and enrichment from heterogeneous solution using cell size as a biomarker. The approach utilizes the irreversible migration of particles into microscale vortices, developed in parallel expansion-contraction trapping reservoirs, as the cell isolation mechanism. We empirically determined the critical particle∕cell diameter D(crt) and the operational flow rate above which trapping of cells∕particles in microvortices is initiated. Using this approach we successfully separated larger cancer cells spiked in blood from the smaller blood cells with processing rates as high as 7.5×10(6) cells∕s. Viable long-term culture was established using cells collected off-chip, suggesting that the proposed technique would be useful for clinical and research applications in which in vitro culture is often desired. The presented technology improves on current technology by enriching cells based on size without clogging mechanical filters, employing only a simple single-layered microfluidic device and processing cell solutions at the ml∕min scale. 相似文献
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104.
The incidence of overeducation in eight European countries is here assessed by means of multiple indicators. With the exception
of Spain, the results reveal that overeducation is a minor risk amongst European tertiary graduates. Yet, the contrast between
different indicators reveals the existence of an overeducation of a moderate kind in countries with high rates of tertiary
attainment (Norway, Finland and Netherlands). Our results also reveal the importance of higher education differentiation for
understanding the risk of overeducation. Graduates from humanistic fields, bachelor courses and vocational colleges are more
exposed to overeducation, though their disadvantage varies cross-nationally. 相似文献
105.
Lea A. Theodore PhD Richard J. DioGuardi PhD Tammy L. Hughes PhD Danielle Aloiso PsyD Melissa Carlo Darren Eccles 《Journal of educational and psychological consultation》2013,23(4):275-299
Homework completion has an important impact on the overall academic functioning of students. Consultation requests often center on identifying efficient interventions so that teachers may facilitate the homework process and enhance students' academic achievement. This investigation employed a randomized interdependent group contingency and randomized reinforcers to improve homework completion and accuracy of spelling performance in 21 elementary school students. An ABAB reversal design across all students was employed. Results showed this intervention to have a positive impact on both spelling homework completion and accuracy rates. Limitations, future research, and contributions are addressed. 相似文献
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108.
Mariacristina Cocca Lucia D'Arienzo Loredana D'Orazio Gennaro Gentile Carlo Mancarella Ezio Martuscelli Carmen Polcaro 《Journal of Cultural Heritage》2006,7(4):236-243
With the aim of identifying new water dispersed polymers for textile conservation, the structure and properties of three commercial polyacrylates and one commercial polyvinylacetate were analysed. The characteristics of these materials, not previously used in the conservation and restoration fields, were compared with that shown by Primal AC33 and Mowilith DMC2 and SDM5, widely used as consolidating or adhesive agents of ancient textiles. To achieve a thorough characterisation of each polymer, molecular, thermal, structural and mechanical investigation techniques were applied on film samples, obtained from polymer water dispersions through water casting at room temperature and/or compression moulding. The photo-oxidative resistance of these materials was also assessed by artificial weathering of water cast films and by measuring the Yellowing Index (YI) as a function of the exposure time under xenon-arc lamp. Collected data were used to appropriately compare the performances shown by these polymers when applied on artefacts consisting of natural fibres. In particular it was found that, among the products not previously used in the conservation and restoration fields, a high potential for carrying out treatments on textiles is shown by the samples commercialised with the trade names of Acrilem RP6005 and Acrilem 30WA. These products, in fact, exhibit properties that make them suitable as substitutes for Primal AC33 and Mowilith DMC2 and SDM5, respectively, depending upon conservation needs. It was very interesting to note that Acrilem 30WA, also after aging, shows YI values lower than that shown by Mowilith DMC2 and SDM5. 相似文献
109.
The Relations of Maternal Practices and Characteristics to Children''s Vicarious Emotional Responsiveness 总被引:1,自引:0,他引:1
Nancy Eisenberg Richard A. Fabes Gustavo Carlo Debra Troyer Anna Lee Speer Mariss Karbon Galen Switzer 《Child development》1992,63(3):583-602
This study examined the relations of maternal vicarious emotional responding and child-rearing practices, as well as familial emotional environment, to 5-6 and 8-9-year-old children's vicarious emotional responding. There were some correspondences between mothers' and children's heart rate, facial, and self-reported reactions to a sympathy-inducing film. Maternal sympathy/perspective taking and reinforcement of sympathy/prosocial behavior, as well as negative subordinate emotion in the home, were associated with markers of girls' sympathy; mothers' personal distress (for girls), restrictiveness regarding displays of hurtful negative emotions (particularly for young girls), and negative dominant emotion in the home (for both sexes) were associated with markers of personal distress. Mothers' linking of the film character's experience to children's own experience was associated with children's responsiveness to the film, and mother's verbalizations during the film concerning her own emotional state and role taking were associated with boys' self-reported sympathy. 相似文献
110.
Juliano Fernandes-da-Silva Carlo Castagna Anderson Santiago Teixeira Lorival José Carminatti Luiz Guilherme Antonacci Guglielmo 《Journal of sports sciences》2016,34(24):2238-2245
ABSTRACTThe aim of this study was to examine the relationship between the peak velocity derived from the Carminatti Test (T-CAR) (PVT-CAR) and physical match performance in young soccer players. Thirty-three youth soccer players were recruited from 2 non-professional clubs. Friendly matches and small-sided game were performed. Physical match demands were assessed using Global Positioning System (GPS) technology. On a separate occasion, the players were submitted to the T-CAR. Players were categorised into 3 groups based on their T-CAR performance: Low (PVT-CAR ≤ P33), Intermediate (P33 > PVT-CAR < P66) and High (PVT-CAR ≥ P66). The PVT-CAR (15.5 ± 0.7 km·h?1) was significantly related to high-intensity activities (HIA; r = 0.78, P < 0.001), high-intensity running (HIR; r = 0.66, P < 0.001), sprinting (r = 0.62, P < 0.001) and total distance (TD) covered (r = 0.47, P < 0.01) during friendly matches. The PVT-CAR was strongly correlated with the amount of HIA (r = 0.81, P < 0.001), HIR (r = 0.85, P < 0.001) and TD covered (r = 0.81, P < 0.001) during small-sided game. No significant correlation was observed between the PVT-CAR and distance of sprinting (r = 0.49, P = 0.067) during small-side game. Furthermore, players in the High group covered significantly more TD (10%) and did more HIA (42%), sprinting (31%) and HIR (25%) during friendly matches compared to the players classified as having Low performance on the T-CAR. These differences still remained after adjusting for chronological age (CA), maturity and body size. In conclusion, the current study gives empirical support to the ecological and construct validity of this novel field test (T-CAR) as an indicator of match-related physical performance in young soccer players during pubertal years. 相似文献