Stereolithography as a manufacturing method for a hierarchically porous ZSM-5 zeolite structure with adsorption capabilities

Hierarchically porous structures are important in adsorption applications and can be used in gas treatment. Hierarchy in adsorbents offers flow channels on different scales, resulting in fast gas flow into a structure. Additive manufacturing, a technology capable of forming intricate geometries, was seen as a potential method to form porous adsorption structures. Stereolithography was chosen as the fabrication method for hierarchically porous zeolite structures because of its high resolution and superior forming capability. The focus of this study was on tailoring the properties of light-cured resin to maximize stability during shaping and shape retention in the debinding stage. Successful slurry preparation was required for demonstrating that monoliths with channel geometry and retained adsorption properties can be manufactured with stereolithography. The final printed structures exhibited hierarchical porosity consisting of flow channels, macropores between the primary particles and the characteristic microporosity of zeolite framework. The structure was manufactured by using blue light to cure layers of resin containing ZSM-5 zeolite. An appropriate debinding heat-treatment cycle was generated based on the TGA and DSC thermal analysis results. The properties of the porous structure were analysed by comparing the BET surface area, XRD patterns and SEM images of as-received powder and a debound piece. The measured BET adsorption properties of the final monoliths remained comparable to the as-received ZSM-5 powder. Based on this study, stereolithography can be utilized to manufacture porous zeolite structures.     

Occurrence of acidic pharmaceuticals in raw and treated sewages and in receiving waters

The occurrence of five acidic pharmaceuticals, ibuprofen, naproxen, ketoprofen, diclofenac and bezafibrate, in seven different sewage treatment plants (STP) and three receiving waters were determined. The analytical procedure included solid phase extraction, liquid chromatographic separation and detection by a triple-quadrupole mass spectrometer. The studied pharmaceuticals were found in all the STPs. The pattern of the occurrence of individual compounds was the same in every STP and matched the consumption figures reported in the literature. Ibuprofen is the most used pharmaceutical in Finland and was accordingly found to be the most abundant compound in the raw sewage. In the treatment processes, the highest removal rate was observed for ibuprofen and the lowest for diclofenac, 92%+/-8% and 26%+/-17%, respectively. Due to the incomplete removal in the STPs, the pharmaceuticals were found in rivers at the discharge points of the STP effluents. Downstream from the discharge points, the concentrations decreased significantly mainly due to dilution in the river water. The risk to the aquatic environment was estimated by a ratio of measured environmental concentration (MEC) and predicted no-effect concentration (PNEC). At the concentrations the compounds were found in the surface waters, they should not pose risk for the aquatic environment. However, at dry seasons and/or during malfunctions of STPs, ibuprofen could be associated with a risk in small river systems.     

Plant flavonol quercetin and isoflavone biochanin A differentially induce protection against oxidative stress and inflammation in ARPE-19 cells

In this work, differential ability of plant flavonol quercetin and plant isoflavone biochanin A to modulate oxidative stress and inhibit inflammation-related responses was investigated using human retinal pigment epithelial cells (RPE) at gene expression level. Quercetin protected cells from oxidative stress-induced cell death, whereas biochanin A had no statistically significant protective effects. Quercetin reduced the expression of cytokines IL-6 and IL-1?? in cells treated with H₂O₂, and expression levels of Nrf2 and HO-1 were increased by quercetin treatment suggesting protective function against oxidative stress. Our data indicate that quercetin may protect cells by inhibiting the production of pro-inflammatory factors such as IL-6, and by inducing the expression of ROS-catalyzing phase II proteins such as HO-1. Therefore, plant extracts rich in flavonol quercetin may be an interesting resource for functional food products and other foods targeted for reduced risks of age-related macular degeneration.     

TiO2(B) as a promising high potential negative electrode for large-size lithium-ion batteries

Needle-like TiO₂(B) powder was obtained from K₂Ti₄O₉ precursor by ion exchange to protons, followed by dehydration. The charge and discharge characteristics of the TiO₂(B) powder were investigated as a high potential negative electrode in lithium-ion batteries. It had a high discharge capacity of 200–250 mAh g⁻¹ at around 1.6 V vs. Li/Li⁺, which was comparable with that of TiO₂(B) nanowires and nanotubes prepared via a hydrothermal reaction in alkaline solution. It showed very good cycleability, and gave a discharge capacity of 170 mAh g⁻¹ even in the 650th cycle. It also had a high rate capability, and gave a discharge capacity of 106 mAh g⁻¹ even at 10 °C.     

Effects of electroacupuncture and transcutaneous electrical nerve stimulation on survival of musculocutaneous flap in rats

The effects of electroacupuncture (EA) and transcutaneous electrical nerve stimulation (TENS) were investigated in the musculocutaneous flap in a rat model by measuring the surviving area and blood flow in the flap. Rats were divided into the control group, and groups treated with EA and TENS. Experimental results of this study show that flap survival area did not increase by EA but increased significantly by TENS treatment, and that blood flow in the periphery was significantly larger than that at the base.     

Reorganization of Thalamic Inputs to Lesioned Cortex Following Experimental Traumatic Brain Injury

Traumatic brain injury (TBI) disrupts thalamic and cortical integrity. The effect of post-injury reorganization and plasticity in thalamocortical pathways on the functional outcome remains unclear. We evaluated whether TBI causes structural changes in the thalamocortical axonal projection terminals in the primary somatosensory cortex (S1) that lead to hyperexcitability. TBI was induced in adult male Sprague Dawley rats with lateral fluid-percussion injury. A virus carrying the fluorescent-tagged opsin channel rhodopsin 2 transgene was injected into the ventroposterior thalamus. We then traced the thalamocortical pathways and analyzed the reorganization of their axonal terminals in S1. Next, we optogenetically stimulated the thalamocortical relays from the ventral posterior lateral and medial nuclei to assess the post-TBI functionality of the pathway. Immunohistochemical analysis revealed that TBI did not alter the spatial distribution or lamina-specific targeting of projection terminals in S1. TBI reduced the axon terminal density in the motor cortex by 44% and in S1 by 30%. A nematic tensor-based analysis revealed that in control rats, the axon terminals in layer V were orientated perpendicular to the pial surface (60.3°). In TBI rats their orientation was more parallel to the pial surface (5.43°, difference between the groups p < 0.05). Moreover, the level of anisotropy of the axon terminals was high in controls (0.063) compared with TBI rats (0.045, p < 0.05). Optical stimulation of the sensory thalamus increased alpha activity in electroencephalography by 312% in controls (p > 0.05) and 237% (p > 0.05) in TBI rats compared with the baseline. However, only TBI rats showed increased beta activity (33%) with harmonics at 5 Hz. Our findings indicate that TBI induces reorganization of thalamocortical axonal terminals in the perilesional cortex, which alters responses to thalamic stimulation.     

Past, present and future of mobile payments research: A literature review

The mobile payment services markets are currently under transition with a history of numerous tried and failed solutions, and a future of promising but yet uncertain possibilities with potential new technology innovations. At this point of the development, we take a look at the current state of the mobile payment services market from a literature review perspective. We review prior literature on mobile payments, analyze the various factors that impact mobile payment services markets, and suggest directions for future research in this still emerging field. To facilitate the analysis of literature, we propose a framework of four contingency and five competitive force factors, and organize the mobile payment research under the proposed framework. Consumer perspective of mobile payments as well as technical security and trust are best covered by contemporary research. The impacts of social and cultural factors on mobile payments, as well as comparisons between mobile and traditional payment services are entirely uninvestigated issues. Most of the factors outlined by the framework have been addressed by exploratory and early phase studies.     

Strategic Decision-Making of a Born Global: A Comparative Study From Three Small Open Economies

This paper extends current understanding on international growth process of born global firms from the perspective of strategic decision-making. The data were collected from three software companies in Finland, Ireland and Israel both in real-time and retrospectively, and data triangulation was employed to increase the validity of the findings. With a longitudinal approach, we captured the dynamics of the post-entry international growth process and the critical events that act as decision-making triggers. The decision-making of born global firms seems to be characterised by alternating periods of causation- and effectuation-based logics. Triggers for amending the logic include, for example, change of key persons and the search for external funding. Co-existence of the two decision-making logics is possible, due to different degrees of uncertainty in market and technology or multiple decision-makers involved. The contribution of the study is threefold: first, it addresses gaps in international entrepreneurship research by describing how born global firms make strategic decisions and who are involved in the decision-making. Second, it identifies critical incidents which trigger a change in the decision-making process of a born global firm. Third, it provides alternative insights to why decision-making logic may change or why two decision-making logics may co-exist.     

The impact of use context on mobile services acceptance: The case of mobile ticketing

The most important factor in the decision to adopt mobile systems is user perception of their value. However, behavioral theory suggests that context affects user attitude and therefore influences acceptance. We therefore hypothesized that the benefits of mobile systems should be evaluated against users’ contextual needs and that reduced dependence on time and place required providing service at any time and place needed by the user. Mental costs or costs of learning to use the system, however, may not be evaluated in the same way, because system use and learning about it are acts with different contexts. Our findings advance knowledge of IT adoption and suggest that we should start to identify the contexts of both the benefits of use and in learning to use the system.