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排序方式: 共有233条查询结果,搜索用时 15 毫秒
51.
Ming-Cheng Lin Jiraporn Nawarak Tai-Yuan Chen Hsien-Yu Tsai Jung-Feng Hsieh Supachok Sinchaikul Shui-Tein Chen 《Biomicrofluidics》2009,3(3)
Rapid detection of brain natriuretic peptide (BNP) concentration can be used for the diagnosis of acute heart failure and for the evaluation of the effectiveness of a clinical therapy. We used the systematic evolution of ligands by exponential enrichment method to develop DNA aptamers for BNP whose sequences were determined by cloning method and consensus sequence analysis. A total of eight conserved sequences was identified. By combining the fluorescent-labeled aptamers with fast protein lab-on-chip analysis, we could achieve quantification of BNP concentrations with high speed, sensitivity, and specificity. 相似文献
52.
Jason S.-H. Tsai Chao-Lung Wei Shu-Mei Guo Leang S. Shieh Ce R. Liu 《Journal of The Franklin Institute》2008,345(5):508-535
An evolutionary programming-based adaptive observer is presented in this paper to improve the performance of state estimation of nonlinear time-varying sampled-data systems. Also, this paper presents a novel state-space adaptive tracker together with the proposed observer and estimation schemes for nonlinear time-varying sampled-data systems having actuator failures. For the class of slowly varying nonlinear time-varying systems, the proposed methodology is able to achieve the desired fault detection and performance recovery for the originally well-designed systems, as long as the controller having the high-gain property. For practical implementation, we utilize the advantages of digital redesign methodology to convert a well-designed high-gain analog controller/observer into its corresponding low-gain digital controller/observer. Illustrative examples are given to demonstrate the effectiveness of the proposed method. The developed digitally redesigned adaptive tracker with the proposed observer and estimator is suitable for implementation by using microprocessors. 相似文献
53.
This study aims to explore Taiwanese university students’ conceptions of learning biology as memorizing or as understanding, and their self-efficacy. To this end, two questionnaires were utilized to survey 293 Taiwanese university students with biology-related majors. A questionnaire for measuring students’ conceptions of memorizing and understanding was validated through an exploratory factor analysis of participants’ responses. As for the questionnaire regarding the students’ biology learning self-efficacy (BLSE), an exploratory factor analysis revealed a total of four factors including higher-order cognitive skills (BLSE-HC), everyday application (BLSE-EA), science communication (BLSE-SC), and practical works (BLSE-PW). The results of the cluster analysis according to the participants’ conceptions of learning biology indicated that students in the two major clusters either viewed learning biology as understanding or possessed mixed-conceptions of memorizing and understanding. The students in the third cluster mainly focused on memorizing in their learning while the students in the fourth cluster showed less agreement with both conceptions of memorizing and understanding. This study further revealed that the conception of learning as understanding was positively associated with the BLSE of university students with biology-related majors. However, the conception of learning as memorizing may foster students’ BLSE only when such a notion co-exists with the conception of learning with understanding. 相似文献
54.
Yuping Tsai 《Economics of Education Review》2010,29(4):606-617
Studies examining the wage effect of overeducation have generated very consistent results. Their findings suggest that, for workers with similar educational attainment, workers who are overeducated for the job suffer from significant wage penalties. However, most studies use cross-sectional data, implicitly assuming that workers are randomly assigned to being overeducated. Using data from the Panel Study of Income Dynamics for the period 1979–2005, this study conducts a panel analysis to account for time-constant individual characteristics. It uses a numerical approach to provide the wage effects in the presence of non-classical measurement error in the educational mismatch variables. The results provide evidence that overeducated status does not cause lower earnings. Instead, the significant wage differential found in previous studies is simply a result of ignoring the non-random assignment of workers to jobs. 相似文献
55.
Neural Oscillation Reveals Deficits in Visuospatial Working Memory in Children With Developmental Coordination Disorder 下载免费PDF全文
The electroencephalographic (EEG) oscillations associated with visuospatial working memory (VSWM) were examined in children with developmental coordination disorder (DCD; 10–11 years; N = 29) and typically developing (TD) children (10–11 years; N = 29). Behaviorally, DCD showed poorer VSWM than TD, which coincided with the diminished ability of DCD in modulating neural oscillations. Furthermore, prestimulus oscillatory alpha activity was correlated with VSWM performance. The results suggest that children with DCD might have a reduced ability to encode and recognize new information, and in particular have difficulty in maintaining task‐relevant information, resulting in poorer VSWM. This study thus concludes that changes in oscillatory EEG activity reflect some of the problems leading to cognitive deficits in DCD. 相似文献
56.
Jon-Chao Hong Ming-Yueh Hwang Chow-Chin Lu Chi-Ruei Tsai 《Research in Science Education》2017,47(1):185-201
Microteaching has gained considerable attention for its effectiveness in rapid and contextual training in professional development programs. However, the interpretive quality of the teaching demonstration and peer feedback may influence individuals’ attribution and self-correction, leading to ineffective learning. In this study, a microteaching workshop in a professional development program for 78 elementary school science teachers was investigated. The results showed that the effectiveness of microteaching was negatively affected by participants’ perception bias due to social categorization. Moreover, it was indicated that the participants’ perception of the in-group and out-group, classified by the degree of the individuals’ science knowledge, fostered social categorization. Participants tended to experience perception conflicts caused by their inability to see personal faults, and a typical perception bias of “seeing one’s own strengths and seeing others’ shortcomings” was more frequently recognized in the out-group. These results converge to highlight the importance of social categorization in perception bias relevant to microteaching. 相似文献
57.
We report a new design of microfluidic chip (Multiple electric Field with Uniform Flow chip, MFUF chip) to create multiple electric field strengths (EFSs) while providing a uniform flow field simultaneously. MFUF chip was fabricated from poly-methyl methacrylates (PMMA) substrates by using CO2 laser micromachining. A microfluidic network with interconnecting segments was utilized to de-couple the flow field and the electric field (EF). Using our special design, different EFSs were obtained in channel segments that had an identical cross-section and therefore a uniform flow field. Four electric fields with EFS ratio of 7.9:2.8:1:0 were obtained with flow velocity variation of only 7.8% CV (coefficient of variation). Possible biological effect of shear force can therefore be avoided. Cell behavior under three EFSs and the control condition, where there is no EF, was observed in a single experiment. We validated MFUF chip performance using lung adenocarcinoma cell lines and then used the chip to study the electrotaxis of HSC-3, an oral squamous cell carcinoma cell line. The MFUF chip has high throughput capability for studying the EF-induced cell behavior under various EFSs, including the control condition (EFS = 0). 相似文献
58.
Overcoming Junior High School Students' Misconceptions About Microscopic Views of Phase Change: A Study of an Analogy Activity 总被引:2,自引:1,他引:1
This study was conducted to examine the effectiveness of an analogy activity, which was designed to overcome junior high students' misconceptions about the microscopic views of phase change. Eighty Taiwanese 8th graders were randomly assigned to either a control group or an experimental group. For the control group, the subjects were instructed through traditional teaching whereas for the experimental group, an analogy activity was conducted on students. This specific analogy activity was presented in the form of role-playing in which students acted as particles and worked together to perform the conditions of phase changes. Through analyzing these students' drawings of the atom arrangements for the three states of some substances, it was found that the students of experimental group, though in many cases, did not perform statistically better than did those of control group in an immediate posttest. The comparisons of a delay test between these two groups indicated that the analogy activity had clearly positive impacts on students' conceptual change on these scientific concepts in terms of long-term observations. 相似文献
59.
Shau-Chun Wang Hsien-Hung Wei Hsiao-Ping Chen Min-Hsuan Tsai Chun-Ching Yu Hsueh-Chia Chang 《Biomicrofluidics》2008,2(1)
A transient 106-fold concentration of double-layer counterions by a high-intensity electric field is demonstrated at the exit pole of a millimeter-sized conducting nanoporous granule that permits ion permeation. The phenomenon is attributed to a unique counterion screening dynamics that transforms half of the surface field into a converging one toward the ejecting pole. The resulting surface conduction flux then funnels a large upstream electro-osmotic convective counterion flux into the injecting hemisphere toward the zero-dimensional gate of the ejecting hemisphere to produce the superconcentration. As the concentrated counterion is ejected into the electroneutral bulk electrolyte, it attracts co-ions and produce a corresponding concentration of the co-ions. This mechanism is also shown to trap and concentrate co-ion microcolloids of micron sizes too (macroions) and hence has potential application in bead-based molecular assays. 相似文献
60.
The purpose of this study is to examine the moderating role of cognitive load experience between students’ scientific epistemic beliefs and information commitments, which refer to online evaluative standards and online searching strategies. A total of 344 science-related major students participated in this study. Three questionnaires were used to ascertain the students’ scientific epistemic beliefs, information commitments, and cognitive load experience. Structural equation modeling was then used to analyze the moderating effect of cognitive load, with the results revealing its significant moderating effect. The relationships between sophisticated scientific epistemic beliefs and the advanced evaluative standards used by the students were significantly stronger for low than for high cognitive load students. Moreover, considering the searching strategies that the students used, the relationships between sophisticated scientific epistemic beliefs and advanced searching strategies were also stronger for low than for high cognitive load students. However, for the high cognitive load students, only one of the sophisticated scientific epistemic belief dimensions was found to positively associate with advanced evaluative standard dimensions. 相似文献