Microfluidic wet spinning of chitosan-alginate microfibers and encapsulation of HepG2 cells in fibers

The successful encapsulation of human hepatocellular carcinoma (HepG2) cells would greatly assist a broad range of applications in tissue engineering. Due to the harsh conditions during standard chitosan fiber fabrication processes, encapsulation of HepG2 cells in chitosan fibers has been challenging. Here, we describe the successful wet-spinning of chitosan-alginate fibers using a coaxial flow microfluidic chip. We determined the optimal mixing conditions for generating chitosan-alginate fibers, including a 1:5 ratio of 2% (w∕w) water-soluble chitosan (WSC) solution to 2% (w∕w) alginate solution. Ratio including higher than 2% (w∕w) WSC solution increased aggregation throughout the mixture. By suspending cells in the WSC-alginate solution, we successfully fabricated HepG2 cell-laden fibers. The encapsulated HepG2 cells in the chitosan-alginate fibers were more viable than cells encapsulated in pure alginate fibers, suggesting that cross-linked chitosan provides a better environment for HepG2 cells than alginate alone. In addition, we found that the adhesion of HepG2 cells on the chitosan-alginate fiber is much better than that on the alginate fibers.     

Bromo-oxidation reaction in enzyme-entrapped alginate hollow microfibers

In this article, the authors present the fabrication of an enzyme-entrapped alginate hollow fiber using a microfluidic device. Further use of enzyme-entrapped alginate hollow fibers as a biocatalytic microchemical reactor for chemical synthesis is also deliberated in this article. To ensure that there is no enzyme leaching from the fiber, fiber surfaces were coated with chitosan. To confine the mobility of reactants and products within the porous hollow fibers the entire fibers were embedded into a transparent polydimethylsiloxane (PDMS) matrix which also works as a support matrix. A vanadium-containing bromoperoxidase enzyme isolated from Corallina confusa was used as a model enzyme to demonstrate the use of these alginate hollow-fiber reactors in bromo-oxidation of phenol red to bromophenol blue at different dye flow rates. Stability of the entrapped enzyme at different temperatures and the effect of the chitosan coating on the reaction conversion were also studied. It was observed that molecules as big as 27 kDa can be retained in the matrix after coating with chitosan while molecules with molecular-weight of around 378 Da can still diffuse in and out of the matrix. The kinetic conversion rate in this microfluidic bioreactor was more than 41-fold faster when compared with the standard test-tube procedure.     

Rapid and cost-effective fabrication of selectively permeable calcium-alginate microfluidic device using ��modified�� embedded template method

In this paper, we have presented a non-lithographic embedded template method for rapid and cost-effective fabrication of a selectively permeable calcium-alginate (Ca-alginate) based microfluidic device with long serpentine delay channel. To demonstrate the versatility of the presented method, we have demonstrated two different strategies to fabricate serpentine long delay channels without using any sophisticated microfabrication techniques, in formal lab atmosphere. The procedure presented here, also, enables the preparation of a multilayered microfluidic device with channels of varying dimensions, in a single device without using any sophisticated micromachining instrumentation. In addition, we have also qualitatively studied the diffusion of small and large molecules from a Ca-alginate based microfluidic device and proposed a method to effectively control the out-flow of macro biomolecules from the crosslinked Ca-alginate matrix to create a selectively permeable matrix required for various biological and biomimetic applications, as mentioned in the Introduction section of this work.     

Assessing the quality and equality of Hong Kong basic education results from PISA 2000+ to PISA 2006

This paper seeks to examine the quality and equality of basic education of Hong Kong based on the first three cycles of the Program for International Student Assessment (PISA). Results from these three assessments suggested that the Hong Kong students have an outstanding performance in mathematics, science and reading. In particular, the performance of reading improves substantially in PISA 2006. As far as equality in education is concerned, the achievement gap of students from different socio-economic backgrounds in Hong Kong is relatively small compared with other countries. However, the academic performance variation between-schools suggest that, there is still academic segregation among secondary schools in Hong Kong although it has been reduced slightly in the PISA 2006.     

Meeting the highly qualified teachers challenge

The moulding of the future of a nation depends on the teachers and the education they provide in schools. Research evidence from the US. National Assessment of Educational Progress (NAEP) confirms this to be the case. Quantitative analysis of data indicates that measures associated with pre-service teacher preparation are by far the strongest correlates of student achievement (Darling-Hammond 2000). The research report of Wilson, Floden, and Ferrini-Mundy (2001) also suggests a strong relationship between teacher preparation and teacher effectiveness. Other research studies similarly indicate that differences in teacher quality are the most crucial for student achievement when compared with variables such as class size, streaming, or the amount of homework (Anderson & Helms 2001; Mendro 1998; Powell & Anderson 2002; Rivkin, Hanushek & Kain 2001; Saunders & Horn 1994; Strong & Tucker 2000) as possible contributory factors. In the pursuit of improved student achievement, we therefore need to examine seriously the role of teacher variables, ranging from teacher qualifications and their subject matter knowledge, to what motivates them to take up teaching as a career and as a consequence, how they teach in classrooms.     

Teachers’ perception of mobile edutainment for special needs learners: the Malaysian case

Study of Malaysian adoption of mobile learning (m-learning) is still in the early stages. However, there are numerous researchers in the country exploring the potential and application of m-learning in the Malaysian education system, including special education. A key question is whether teachers are prepared to incorporate mobile technology as part of their teaching tools or do teachers perceive mobile technology only as personal communication gadgets. This paper investigates teachers' perception of m-learning applications in special education classes. Interviews were conducted to collect related information on teachers' perceptions of m-learning in the selected schools. The teachers expressed that there are limited resources to cater to the attention of special needs learners and they believed edutainment technologies such as augmented reality, game-based educational software and animation projects could be the answer. The benefits and challenges of implementing blended learning for special education are also discussed. The paper concludes by summarising the current environment of m-learning in Malaysian special needs education, together with recommendations for future use of the technology.     

The Things Girls Shouldn't See: Relocating the penis in sex education in Hong Kong

This article reports on how young women in Hong Kong relate to the penis. A total of nine focus group interviews were conducted at the University of Hong Kong to enable participants to reflect on and talk about their 'experience of the penis'. It is found that despite society's various attempts to restrict their access to the penis, it is very much present and available to the young women in Hong Kong. While most of the participants reported the normative response of disgust, which was expected as part of the 'proper femininity', positive experiences of the penis characterised by agency, mastery and fulfilment were also reported. Some of the things they do, such as watching an exhibitionist or actively consuming sexually explicit materials and pornography, subvert the discursive practice of positioning women as passive sexual objects. It is believed that with more open access to knowledge and experience, women will stand a better chance of achieving a more agentive relationship, not only with the penis as a potential transitional object in intimate relationships, but also with their own sexuality.     

The purposes outdoor education does,could and should serve in Singapore

This paper discusses the purposes that outdoor education does, could and should serve in Singapore. Gert Biesta’s conceptualisation of three functions of education is adapted to frame deliberations on the purposes of outdoor education in Singapore’s socio-political and educational milieu. The author suggests that outdoor education in Singapore could and should give high priority to serving three educational purposes; namely, building resilience, building emotional bonds with the place that constitutes Singapore, and building ecological literacy. In pursuing such purposes, outdoor education in Singapore might lessen the gap between the educational outcomes it currently produces and those it could achieve in the future.     

The impact of organizational learning capacity from the socio-cognitive perspective on organizational commitment

This study is to examine the impact of organizational learning on affective commitment in Korea. In particular, this study addressed the importance of organizational learning as an HRD strategy from the socio-cognitive perspective. Data were collected from four large companies located in the area of Seoul, South Korea. There were 233 usable questionnaires yielding a response rate of 61 %. Multiple regression analysis and principal factor analyses were applied to conduct a data analysis. The results showed that a linear relationship existed between the organizational learning capacity and affective commitment (R ² = .495). Four dimensions were statistically significant with the exception of “feedback.” Participative decision-making is the most important factor. Finally, the study discussed some implications for HRD theory and practice.