On-chip recalcification of citrated whole blood using a microfluidic herringbone mixer

In vitro assays of platelet function and coagulation are typically performed in the presence of an anticoagulant. The divalent cation chelator sodium citrate is among the most common because its effect on coagulation is reversible upon reintroduction of divalent cations. Adding divalent cations into citrated blood by batch mixing leads to platelet activation and initiation of coagulation after several minutes, thus limiting the time blood can be used before spontaneously clotting. In this work, we describe a herringbone microfluidic mixer to continuously introduce divalent cations into citrated blood. The mixing ratio, defined as the ratio of the volumetric flow rates of citrated blood and recalcification buffer, can be adjusted by changing the relative inlet pressures of these two solutions. This feature is useful in whole blood assays in order to account for differences in hematocrit, and thus viscosity. The recalcification process in the herringbone mixer does not activate platelets. The advantage of this continuous mixing approach is demonstrated in microfluidic vascular injury model in which platelets and fibrin accumulate on a collagen-tissue factor surface under flow. Continuous recalcification with the herringbone mixer allowed for flow assay times of up to 30 min, more than three times longer than the time achieved by batch recalcification. This continuous mixer allows for measurements of thrombus formation, remodeling, and fibrinolysis in vitro over time scales that are relevant to these physiological processes.     

Improving ethical attitudes to animals with digital technologies: the case of apes and zoos

Ethics and Information Technology - This paper examines how digital technologies might be used to improve ethical attitudes towards nonhuman animals, by exploring the case study of nonhuman apes...     

Promoting effective e-learning practices through the constructivist pedagogy

Although rapid advances in technology has allowed for the growth of collaborative e-learning experiences unconstrained by time and space, technology has not been heavily infused in the activities of teaching and learning. This article examines the theory of constructivism as well as the design of e-learning activities using constructivist principles. The manner in which constructivist theory supports e-Learning is explored, and extrapolating from this pedagogical theory, some implications are provided to model effective practices of the characteristics and capacities of this powerful learning environment.     

Wirksamkeit schulrelevanter Förderung in Kindertagesstätten

The present paper summarizes international and national research findings on the general and differential effectiveness of pedagogical work in early childhood education and care settings, evaluations of pilot projects on compensatory preschool education as well programs to support individual learning abilities. Based on these findings, the following conclusions are drawn: First, attending early childhood education and care settings at an early age (after the age of three) has a positive influence on the development of academic competences. Second, the effectiveness of these settings depends on the instructional quality, which could be considerably improved in Germany. Third, pilot projects on programs to support individual learning abilities could show that compensatory effects for disadvantaged groups of children exist, especially when they are interlinked with stimulating conditions in the family and at school. Fourth, effective training programs exist that can be implemented in early childhood education and care. However, a number of challenges need to be met before they can be successfully implemented.     

To explore or to exploit? An empirical investigation of acquisitions by large incumbents

Innovation in high technology industries poses considerable challenges, frequently forcing firms to consider using acquisitions as a means of sourcing technology. This paper investigates such behaviour in a major high technology sector, namely the semiconductor industry. The paper focuses on differential effects of technology-related versus nontechnological acquisitions on exploratory and exploitative research and innovation. Most importantly, it confirms the important role of technology-related acquisitions for exploratory innovation.     

Dielectrophoretic manipulation of ribosomal RNA

The manipulation of ribosomal RNA (rRNA) extracted from E. coli cells by dielectrophoresis (DEP) has been demonstrated over the range of 3 kHz-50 MHz using interdigitated microelectrodes. Quantitative measurement using total internal reflection fluorescence microscopy of the time dependent collection indicated a positive DEP response characterized by a plateau between 3 kHz and 1 MHz followed by a decrease in response at higher frequencies. Negative DEP was observed above 9 MHz. The positive DEP response below 1 MHz is described by the Clausius-Mossotti model and corresponds to an induced dipole moment of 3300 D with a polarizability of 7.8×10(-32) F m(2). The negative DEP response above 9 MHz indicates that the rRNA molecules exhibit a net moment of -250 D, to give an effective permittivity value of 78.5 ε(0), close to that of the aqueous suspending medium, and a relatively small surface conductance value of ～0.1 nS. This suggests that our rRNA samples have a fairly open structure accessible to the surrounding water molecules, with counterions strongly bound to the charged phosphate groups in the rRNA backbone. These results are the first demonstration of DEP for fast capture and release of rRNA units, opening new opportunities for rRNA-based biosensing devices.     

VOSviewer and Bibliometrix

VOSviewer (version 1.6.17, July 22, 2021). Centre for Science and Technology Studies, Leiden University, The Netherlands. https://www.vosviewer.com; free, donations accepted.Bibliometrix (version 3.1, Sep 24, 2021). Department of Economics and Statistics, University of Naples Federico II, Italy. ;gro.xirtemoilbib@ofni https://www.bibliometrix.org/; free, donations accepted.     

An Exploratory Examination and Critique of Academic Law Librarian Blogs: A Look into an Evolving Reference Communication Practice

This study is an exploratory qualitative investigation of academic library blogs with the purpose of examining how the technology of blogging is evolving for reference and research purposes at particular academic law libraries. This study uses anthropological archive research methods to study the blogs’ posts and triangulates the study with librarian blogger interviews. It provides a look into possible future directions for blogging in academic law libraries that may serve as a model for other academic libraries.