Morphological control on SBA-15 mesoporous silicas via a slow self-assembling rate

Pluronic 123-templated mesoporous SBA-15 silica rods with a length of ca. 3.0–4.0 μm were easily synthesized in a dilute silicate solution with a pH value of 2.0 at room temperature. Through a good control on the synthetic condition and the chemical components, a high homogeneity (>95%) of the hexagonal SBA-15 silica rods can be achieved. In addition, the effect of the synthetic conditions including acid source, weight ratio of the P123/sodium silicate, temperature, water content, pH value, and applying shearing flow were explored in detail to tailor the morphologies of the SBA-15 mesoporous silicas. In this paper, we also focused on the counterion effect on the synthesis of the SBA-15 mesoporous silicas. It was found that the SO₄ ²⁻ counterion from H₂SO₄ has higher affinity to induce the formation of P123 rod-like micelles than that of Cl⁻, NO₃ ⁻. Meanwhile, we postulated that the self-assembly pathway of the silica species and the neutral tri-block copolymer micelles in a dilute solution with a pH value of 2.0 would occur through an S⁰···I⁰ rather than the S⁰X^−…I⁺ one as previously discussed. We further employed the SAB-15 mesoporous silica rods as the templates to synthesize high-quality CMK-3 mesoporous carbon rods by using commercially available phenol–formaldehyde (PF) resin as the carbon source.     

The implementation of an IoT-based exercise improvement system

The benefits of exercise have been well known for years. Most people know that they should do more exercise, but they seldom make exercise a top priority. Regular exercise is generally the most important lifestyle change people can make to improve their health, but it is hard for people to sustain a regular exercise program. On the other hand, Internet of Things (IoT) applications, which combine different sensors and information technologies, have developed rapidly over recent years. IoT-based applications for exercise have been examined in recent literature. However, most IoT-based applications focus on the needs of exercisers and ignore the needs of trainers and the relationship between the system usage and the incidence of regular exercise compliance is rarely studied. This study implements an IoT-based exercise improvement system that both exercisers and trainers can use to increase exercisers’ physical fitness. To test the system, 221 students were recruited from a university and their exercise data were collected and analyzed. The results showed that use of an IoT-based exercise improvement system helped regular exercisers maintain their exercise pattern and non-regular exercisers improve their exercise performance.

     

MicroRNA-Regulated Protein-Protein Interaction Networks and Their Functions in Breast Cancer

MicroRNAs, which are small endogenous RNA regulators, have been associated with various types of cancer. Breast cancer is a major health threat for women worldwide. Many miRNAs were reported to be associated with the progression and carcinogenesis of breast cancer. In this study, we aimed to discover novel breast cancer-related miRNAs and to elucidate their functions. First, we identified confident miRNA-target pairs by combining data from miRNA target prediction databases and expression profiles of miRNA and mRNA. Then, miRNA-regulated protein interaction networks (PINs) were constructed with confident pairs and known interaction data in the human protein reference database (HPRD). Finally, the functions of miRNA-regulated PINs were elucidated by functional enrichment analysis. From the results, we identified some previously reported breast cancer-related miRNAs and functions of the PINs, e.g., miR-125b, miR-125a, miR-21, and miR-497. Some novel miRNAs without known association to breast cancer were also found, and the putative functions of their PINs were also elucidated. These include miR-139 and miR-383. Furthermore, we validated our results by receiver operating characteristic (ROC) curve analysis using our miRNA expression profile data, gene expression-based outcome for breast cancer online (GOBO) survival analysis, and a literature search. Our results may provide new insights for research in breast cancer-associated miRNAs.     

Chemical deposition of platinum on metallic sheets as counterelectrodes for dye-sensitized solar cells

Platinum (Pt) layers were grown on metallic sheets, either stainless steel or nickel (Ni), by chemical deposition, and the resulting Pt-coated metallic sheets were used as counterelectrodes for dye-sensitized solar cells (DSSCs). Compared with other methods of depositing Pt layers, chemical deposition is simple, low-temperature, and easy to scale-up for industrial applications. Thin metallic sheets were employed as the substrates for the Pt deposition because of their low cost, excellent electrical conduction capability, and flexibility. The Pt concentration of the plating solution plays an important role in the photovoltaic performance of the DSSC; higher Pt concentrations correlate with better photovoltaic performance. The DSSCs that use Ni sheets coated with chemically deposited Pt as the counterelectrodes were found to have lower series and charge transfer resistances compared with those based on stainless steel. The Ni-based DSSCs also exhibit higher fill factors and short-circuit currents, and therefore, better energy conversion efficiency. The best efficiency observed with the Ni-based DSSCs was 7.29%.     

Chitosan microfiber fabrication using a microfluidic chip and its application to cell cultures

In this study, a poly-methyl-methacrylate (PMMA) microfluidic chip with a 45° cross-junction microchannel is fabricated using a CO₂ laser machine to generate chitosan microfibers. Chitosan solution and sodium tripolyphosphate (STPP) solution were injected into the cross-junction microchannel of the microfluidic chip. The laminar flow of the chitosan solution was generated by hydrodynamic focusing. The diameter of laminar flow, which ranged from 30 to 50 μm, was controlled by changing the ratio between chitosan solution and STPP solution flow rates in the PMMA microfluidic chip. The laminar flow of the chitosan solution was converted into chitosan microfibers with STPP solution via the cross-linking reaction; the diameter of chitosan microfibers was in the range of 50–200 μm. The chitosan microfibers were then coated with collagen for cell cultivation. The results show that the chitosan microfibers provide good growth conditions for cells. They could be used as a scaffold for cell cultures in tissue engineering applications. This novel method has advantages of ease of fabrication, simple and low-cost process.     

Electroless deposition of platinum on indium tin oxide glass as the counterelectrode for dye-sensitized solar cells

A platinum (Pt) layer is electroless-deposited on indium tin oxide (ITO) glass substrate as the counterelectrode for dye-sensitized solar cells (DSSCs). Compared with other methods of depositing Pt layer, electroless deposition is simple, low-temperature, and easy to scale-up for industrial application. The Pt concentration of the electroless plating solution is found to play an important role in the cell performance. With increasing the Pt concentration, i.e. the Pt loading on the ITO surface, the resultant Pt layer exhibits a porous structure. Owing to the porous structure, the Pt layer can provide more active surface area for triiodide reduction and thus reduces the charge-transfer resistance. The cell performance is promoted accordingly with increasing the Pt concentration. Energy conversion efficiency of 6.46%, short-circuit current density of 15.04 mA cm⁻², open-circuit voltage of 0.68, and fill factor of 0.63 can be achieved for the DSSC employing electroless-Pt counterelectrode.