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31.
Giseok Kang Young-jae Kim Hong-sang Moon Jeong-Woo Lee Tag-Keun Yoo Kwangsung Park Jong-Hyun Lee 《Biomicrofluidics》2013,7(4)
The prostate biopsy method shows a high false negative result because the suspicious tissue considered as cancer is not confirmed during tissue sampling. Thus, repeated biopsy procedures and diagnostic errors in relation to prostate cancer frequently occur. The purpose of this research is to enhance the prostate cancer detection rate by using microfluidic electrical impedance spectroscopy (μEIS), which allows real-time measurement of the electrical impedance of a single human prostate normal cell and cancer cell. The μEIS was equipped with a movable flexible membrane, which is operated by pneumatic pressure to capture the single cell on the surface of sensing electrodes. The forced tight contact between the cell and electrodes makes it possible to measure the electrical characteristics of the cell with a high sensitivity. The μEIS discriminates well between normal human prostate cells (RWPE-1) and cancer cells (PC-3) at 8.7 kHz based on the electrical signal responses of the cells. The average difference rates of admittance magnitude and susceptance are 54.55% and 54.59%, respectively. The developed μEIS also shows high repeatability, which was verified by a deionized water test conducted before and after each cell assay; the maximum variance of both the impedance and admittance at 8.7 kHz was as small as 9.48%. 相似文献
32.
In cognitive diagnostic models (CDMs), a set of fine-grained attributes is required to characterize complex problem solving and provide detailed diagnostic information about an examinee. However, it is challenging to ensure reliable estimation and control computational complexity when The test aims to identify the examinee's attribute profile in a large-scale map of attributes. To address this problem, this study proposes a cognitive diagnostic multistage testing by partitioning hierarchically structured attributes (CD-MST-PH) as a multistage testing for CDM. In CD-MST-PH, multiple testlets can be constructed based on separate attribute groups before testing occurs, which retains the advantages of multistage testing over fully adaptive testing or the on-the-fly approach. Moreover, testlets are offered sequentially and adaptively, thus improving test accuracy and efficiency. An item information measure is proposed to compute the discrimination power of an item for each attribute, and a module assembly method is presented to construct modules anchored at each separate attribute group. Several module selection indices for CD-MST-PH are also proposed by modifying the item selection indices used in cognitive diagnostic computerized adaptive testing. The results of simulation study show that CD-MST-PH can improve test accuracy and efficiency relative to the conventional test without adaptive stages. 相似文献
33.
Even though isoelectric focusing (IEF) is a very useful technique for sample concentration and
separation, it is challenging to extract separated samples for further processing. Moreover, the
continuous sample concentration and separation are not possible in the conventional IEF. To overcome
these challenges, free flow IEF (FFIEF) is introduced in which a flow field is applied in the
direction perpendicular to the applied electric field. In this study, a mathematical model is developed for FFIEF to understand
the roles of flow and
electric fields for
efficient design of microfluidic
chip for continuous separation of proteins from an initial well mixed solution. A finite volume based
numerical scheme is implemented to simulate two dimensional FFIEF in a microfluidic chip. Simulation results
indicate that a pH gradient forms as samples flow downstream and this pH profile agrees well with
experimental results validating our model. In addition, our simulation results predict the experimental behavior of
pI markers in a FFIEF microchip. This numerical model is used to predict the separation
behavior of two proteins
(serum albumin and cardiac troponin I) in a two-dimensional straight microchip. The effect of
electric field is
investigated for continuous separation of proteins. Moreover, a new channel design is presented to increase the separation
resolution by introducing cross-stream flow velocity. Numerical results indicate that the separation
resolution can be improved by three folds in this new design compare to the conventional straight
channel design. 相似文献
34.
We develop an adoption model of infrastructure technologies and test it with survey data collected from companies in six industries in South Korea (hereafter: Korea). The implementation of a new Internet standard such as Internet Protocol version 6 (IPv6) depends on the usefulness of the technology to the adopting organizations and the environment in which they operate. The adoption of IPv6 in Korea is mostly driven by a governmental strategy that created user demand, and normative pressure. IPv6 adoption in Korea is also driven by perceived resource concentration and power due to the uneven allocation of IPv4 addresses. Conversely, killer applications, technical sponsorship and financial factors had no influence on the adoption decision by Korean companies. Taken together, the findings of our explorative study suggest the need to consider technical as well as social and policy factors to understand the adoption dynamics of infrastructure technologies. 相似文献
35.
The past fourteen years have seen a significant rise in the percentage of Asia–Pacific papers on educational technology (ET) published internationally: from 13.7 % in 2000 to 38.4 % in 2013. This study seeks to identify the overall trends and gaps in this research. Of the 4,332 articles published in five selected international journals between 2000 and 2013, 1,137 (26.2 %) from the Asia–Pacific region [the Asia–Pacific (AP) region includes countries specified by UNESCO and Western Asia (Middle East) countries defined by United Nations] were selected for analysis. It was found that the majority of these came from Taiwan, Korea, Australia, Singapore and China, revealing a need for more studies from such countries as Japan and Indonesia, West and Central Asia and the Pacific Islands. The papers most commonly addressed issues at the micro-level in formal education, particularly higher education, focusing on the introduction of digital technology into on- or off-campus settings. There were few macro-level studies into such areas as policy making, quality assurance or evidence of educational outcomes and impact. It is suggested that researchers should undertake more such comprehensive studies into ET integration, not only in formal education but non-formal, informal, incidental and implicit learning. 相似文献
36.
Takashi Yamashita Jennifer R. Keene Sheniz A. Moonie Jay J. Shen Jennifer R. Pharr Ji Won Yoo 《Educational gerontology》2013,39(10):627-638
ABSTRACTHealth literacy skills are known to be a key mediator of the relationship between education and health in the general population. However, one aspect of health literacy skills—individuals’ actual literacy activities—remains understudied, especially among older adults. Health disparities that are driven by inequalities in education and level of health literacy skills are particularly problematic for older adults since they are exacerbated in old age by disadvantages that accumulate over the life course. This study examined a nationally representative sample of US adults age 50 years and older (n = 2,573) using data from the 2014 Program for International Assessment of Adult Competencies (PIAAC). Parallel mediation analysis was conducted to examine the partial mediation effects of health literacy skills and literacy activity (i.e., reading at home) on the relationship between education and health. Results showed that both health literacy skills and literacy activity mediated the education–health relationship. On average, literacy skills mediated 31.89% and literacy activities mediated 9.59% of the effect of education of self-rated health. Literacy activity, such as reading, is an easily accessible, autonomous, and sustainable option for promoting health in later life. Policies that support the intersection of public health and education may promote lifelong learning and well-being among US adults. 相似文献
37.
“Even a penny will help!” is a donation solicitor's effort in legitimating paltry donations in hopes of gaining higher compliance. This study reexamined the effect of Legitimization of Paltry Donation (LPD) in combination with Social Proof (SP) strategy. Participants were given one of four donation soliciting messages: simple request (control), LPD, SP, and LPD/SP. Compliance rate and size were examined through both the survey experiment and the field experiment. The LPD/SP condition yielded the highest rate of compliance both in the survey and field studies, followed by the LPD condition, the SP condition, and the control condition. As for the donation amount, results were not consistent across the two studies. Implications and limitations of the study were discussed. 相似文献
38.
ABSTRACTThis article is an introduction to the New York Public Library’s revolutionary and post-revolutionary Soviet and East European photography holdings. It outlines the materials available to researchers from both the large and smaller collections, particularly those that are useful for studies of Revolutionary Russia and the History or World War II in Russia and Eastern Europe. Of particular note is the NYPL’s wealth of images documenting Poland during the Second World War and the Bessie Beatty album The Russian Revolution: An Album of Photographs. 相似文献
39.
ABSTRACTThis article is an introduction to the New York Public Library’s pre-revolutionary Russian and Eastern European photographic albums. It also provides a checklist of these albums. The checklist is an especially rich source for Russian architecture, art, and science and provides documentation for a variety of places in the center and provinces of the Russian Empire. Some of the most significant albums are those once owned by the Romanovs and by George Kennan the elder, America’s first Russian expert. 相似文献
40.