A novel method coupling the Langmuir-Blodgett (LB) deposition of silica particles and the formation of a self-assembled monolayer (SAM) of alkylsilane is proposed for fabricating hydrophobic surfaces. The LB deposition and the SAM are supposed to confer the substrate surface roughness and low surface energy, respectively. By controlling the hydrophobic-hydrophilic balance of the silica particle surface through the adsorption of surfactant molecules, deposition of monolayers consisting of hexagonally close-packed arrays of particles on a glass substrate can then be successfully conducted in a Langmuir trough. LB particulate films with a particle layer number up to 5 were thereby prepared. A sintered and hydrophobically finished particulate film with roughness factor of 1.9 was finally fabricated by sintering and surface silanization. Effects of particle size and particle layer number on the wetting behavior of the particulate films were systematically studied by measuring static and dynamic water contact angles. The experimental results revealed that a static contact angle of about 130 degrees resulted from the particulate films regardless of the particle size and particle layer number. This is consistent with the predictions of both the Wenzel model and the Cassie and Baxter model in that roughness of a hydrophobic surface can increase its hydrophobicity and a switching of the dominant mode from Wenzel's to Cassie and Baxter's. In general, an advancing contact angle of about 150 degrees , a receding contact angle of about 110 degrees , and a contact angle hysteresis of about 40 degrees were exhibited by the particulate films fabricated.

This study explored students' perceptions of self-directed learning (SDL) and collaborative learning (CL) with/without technology in an information and communications technologysupported classroom environment. The factors include SDL, CL, SDL supported by technology, and CL supported by technology. Based on the literature review, this study hypothesized that students' perceptions of learning without technology positively predict their perceptions of learning supported by technology. An instrument was developed and two studies, a pilot study and a main study, were undertaken. The pilot study surveyed 219 secondary school students and established the factors through exploratory factor analysis with good validity and reliability. The main study surveyed 500 secondary school students to confirm the factors and to establish the relationships between these factors through structural equation modeling. The results validated the four-factor structure model and revealed that students who reportedly engaged in SDL and CL in face-to-face contexts also engaged in these forms of learning in technology-supported contexts. The findings indicate that students' learning without technology support is related to their use of technology for learning. It may be advisable for teachers to develop students' learning processes in the face-to-face context without technology before engaging them in technology-supported learning.

New variants of porcine epidemic diarrhoea virus (PEDV), which emerged in Taiwan in late 2013, have caused a high morbidity and mortality in neonatal piglets. To investigate the molecular characteristics of the spike (S) gene of the emerging Taiwan PEDV strains for a better understanding of the genetic diversity and relationship among the Taiwan new variants and the global PEDVs, full-length S genes of PEDVs from nine 1-7 day-old piglets from three pig farms in the central and southern Taiwan were sequenced and analysed. The result of phylogenetic analysis of the S gene showed that all the Taiwan PEDV strains were closely related to the non-S INDEL strains from US, Canada and China, suggesting a common ancestor for these strains. As compared with the historic PEDVs and CV777-based vaccine strains, the nine Taiwan PEDV variants shared almost the same genetic signatures as the global non-S INDEL strains, including a series of insertions, deletions and mutations in the amino terminal as well as identical mutations in the neutralizing epitopes of the S gene. The high similarity of the S protein among the Taiwan and the globally emerged non-S INDEL PEDV strains suggests that the Taiwan new variants may share similar pathogenesis and immunogenicity as the global outbreak variants. The development of a novel vaccine based on the Taiwan or the global non-S INDEL strains may be contributive to the control of the current global porcine epidemic diarrhoea outbreaks.

The present study demonstrates the creation of a stable, superhydrophobic surface by coupling of successive Langmuir-Blodgett (LB) depositions of micro- and nano-sized (1.5 µm/50 nm, 1.0 µm/50 nm, and 0.5 µm/50 nm) silica particles on a glass substrate with the formation of a self-assembled monolayer of dodecyltrichlorosilane on the surface of the particulate film. Particulate films, in which one layer of 50 nm particles was deposited over one to five sublayers of larger micro-sized particles, with hierarchical surface roughness and superhydrophobicity, were successfully fabricated. Furthermore, the present 'two-scale' (micro- and nano-sized particles) approach is superior to the previous 'one-scale' (micro-sized particles) approach in that both higher advancing contact angle and lower contact angle hysteresis can be realized. Experimental results revealed that the superhydrophobicity exhibited by as-fabricated particulate films with different sublayer particle diameters increases in the order of 0.5 µm>1.0 µm>1.5 µm. However, no clear trend between sublayer number and surface superhydrophobicity could be discerned. An explanation of superhydrophobicity based on the surface roughness introduced by two-scale particles is also proposed.

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Spherical silica microcapsules containing phase-change material (PCM) were prepared by the sol-gel method in O/W emulsion. This is the first time that inorganic encapsulation of PCM with core/shell structure has been studied. The results of this synthesis revealed that micron size (4 - 8 microm) silica microspheres encapsulating n-pentadecane can be successfully created from acidic solutions ([H+] > or = 1.44 N) by using cationic surfactants as the emulsifiers. The identification of the mechanisms for the formation of silica shell at the oil-water interface indicates that it should be the charge-controlled mechanism through S+X-I+ (positively charged surfactant-halide ion-positively charged silica species) electrostatic interactions or the reaction rates-controlled mechanism working on cationic emulsifiers.

Devastating outbreaks of porcine epidemic diarrhea (PED) started in China in late 2010 and rapidly spread to North America and Asia causing severe diarrhea and high mortality in neonatal piglets, indicating that a new generation of vaccine against porcine epidemic diarrhea virus (PEDV) is urgently needed. In the present study, to mimic the native spike (S) glycoprotein, a stable cell line producing the trimeric ectodomain of S glycoprotein of the PEDV Pintung-52 (PEDV-PT) strain was successfully established by incorporating T4 bacteriophage foldon sequence of fibritin trimerization domains at the C-terminal end and replacing the signal peptide of S protein with the tissue plasminogen activator signal peptide sequence at the N terminal end. The trimeric structure, bio-reactivity to PEDV-specific antibodies, and the N-glycosylation level of the recombinant S protein were characterized. To induce systemic and mucosal immunity, conventional 5-week-old piglets were immunized with the trimeric S glycoprotein combined with the B subunit of Escherichia coli heat-labile enterotoxin (LTB) by the intramuscular (IM) route. As compared with the control group, all piglets in the S protein-LTB immunized (IM PEDV S-LTB) group generated systemic PEDV S-specific IgG and neutralizing antibody in blood but a low level of fecal PEDV-specific IgA and limited protection against challenge of PEDV-PT strain. Our results suggest that the recombinant PEDV trimeric S glycoprotein could be a potential subunit vaccine candidate against PEDV, but IM immunization with LTB as the adjuvant provided insufficient protection. The development of a vaccine regimen for inducing mucosal immunity is an important task for generating a successful subunit vaccine against PEDVs.