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We report on reversible electroporation of cells in a flow-through microfluidic device, whereby the required electric field is delivered through a set of integrated microcapillaries between a centre stream of cells and side streams of liquid electrolytes. The electrolytes are applied with a sine wave voltage and cells flow by the microcapillary openings encounter a burst of ac field with a duration and strength determined by their average speed and spatial proximity to the microcapillary openings, respectively. Effectiveness of the approach is presented through numerical simulations and empirical results on electroporation efficiency and cell viability against various flow rates (exposure time to the field) as well as frequencies and root-mean-square (rms) intensities of the field. High frequencies (80–400 kHz) and high intensities (e.g., 1.6 kV/cm, rms) are identified with increased electroporation efficiency 61% and viability 86% on average. These results suggest that the device demonstrated here with a simple design and robust operation offers a viable platform for flow-through electroporation. 相似文献
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We demonstrate monolithic integration of fine cylindrical glass microcapillaries (diameter ∼1 μm) on silicon and evaluate their performance for electrophoretic separation of biomolecules. Such microcapillaries are achieved through thermal reflow of a glass layer on microstructured silicon whereby slender voids are moulded into cylindrical tubes. The process allows self-enclosed microcapillaries with a uniform profile. A simplified method is also described to integrate the microcapillaries with a sample-injection cross without the requirement of glass etching. The 10-mm-long microcapillaries sustain field intensities up to 90 kV/m and limit the temperature excursions due to Joule heating to a few degrees Celsius only. 相似文献
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Simultaneous group confirmatory factor analyses of the Psychopathy Checklist‐Revised (PCL‐R; Hare, 1991) were conducted with an alcoholic inpatient sample (N= 740). Invariance of the item‐factor relations for the 2 highly correlated factors of Personality and Behavioral Features were supported across 3 racial/ethnic groups (African American, Puerto Rican, and White) and across gender groups. Moment structure analysis indicated no significant differences in the latent means across men and women. Alternative covariance structure models were specified within a multitrait‐multimethod framework to evaluate convergent and discriminant validity across different methods of measuring antisociality. A correlated trait‐correlated method model was supported. A factor intercorrelation of .68 was indicated for Personality and Behavioral Features, and a significant correlation (.40) among method factors emerged for the PCL‐R scores across different raters (interviewers and therapists). General support was provided for the use of the PCL‐R with alcoholic inpatients, though there was a substantial intercorrelation for the factors of Personality and Behavioral Features. 相似文献
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There is debate about whether the leadership style of the teacher or the learning style of the student affects academic achievement more. A large sample (n = 746) of eighth‐grade students in Istanbul, Turkey, participated in a study where the leadership style of the teacher was assessed in terms of people orientation and task orientation. The learning styles examined were: group, individual, visual, auditory, tactile, and kinesthetic. Multiple discriminant analysis indicated that teacher leadership style was the main factor affecting academic performance. No significant relationship was found between learning style and academic achievement. 相似文献
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This study examined correspondence between timing (onset) and tempo (rate) of sexual maturation prospectively (average ages 11–16 years) measured by gonadal hormones and secondary sex characteristics (Tanner stage) using dual-process models, and associations of these measures with substance use (SU) involvement in boys at age 16 years (N = 534, 77.5% White/22.5% Non-White). All measures of timing were highly associated. Early Tanner stage timing often predicted slower increases in gonadal steroids, but not the reverse; patterns varied by ethnicity. Hormone and Tanner stage measures were similar earlier in development but diverged later in development. In White boys only, early timing of the pubertal rise in testosterone was associated with increased SU involvement, suggesting a physiological rather than psychosocial mechanism of association. 相似文献
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Serap Sevimli-Celik Sadettin Kirazci Mustafa Levent Ince 《Early Childhood Education Journal》2011,39(5):323-333
The purpose of this study was to examine the perceptions of preschool administrators and parents about preschool movement
education and movement practices in preschools. Participants were 8 preschool administrators and 21 parents from 8 randomly
selected private preschools in one of the municipalities in Ankara, Turkey. Semi-structured interviews, field visits, and
observations were conducted, and written documents were collected. The findings indicate that preschool administrators and
parents have limited content knowledge in movement education. Movement education practices were not aligned with physical-education
goals for these schools. Children’s participation in organized sport activities is valued more as an extracurricular activity
by administrators and parents. Limited indoor/outdoor spaces for movement activities seem to be among the limiting factors
for movement education practices. To conclude, there is an immediate need to improve preschool administrators’ and parents’
knowledge of movement education and to enhance preschool facilities to ensure quality movement education. 相似文献
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Demir S&#;leyman D&#;&#;&#;nceli Bet&#;l Ertuna Levent &#;olak Tu&#;ba Seda 《International journal for the advancement of counseling》2022,44(2):356-372
International Journal for the Advancement of Counselling - This study examined the level of professional competence of counsellor candidates through their solution strategies against the cases they... 相似文献
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Şahin Ferhan Doğan Ezgi Okur Muhammet Recep Şahin Yusuf Levent 《Education and Information Technologies》2022,27(6):7827-7849
Education and Information Technologies - Information on the emotional outcomes of e-learning system use and emotional aspects of user experience in higher education is quite limited. Accordingly,... 相似文献