Synthesis and sulfate ion-exchange properties of a hydrotalcite-like compound intercalated by chloride ions

To reduce the generation of hydrogen sulfide gas from sulfate ions, we synthesized a layered double hydroxide hydrotalcite-like compound intercalated with chloride ions in the interlayer (HT-Cl) using a coprecipitation reaction. The resultant HT-Cl material had a Mg/Al molar ratio of approximately 2, and the molar fraction of the chloride ions on the intercalated anion layer of the HT was 0.90. A higher molar fraction of chloride ions can be inserted into the interlayers of the HT by increasing the initial concentration ratio of chloride ions to aluminum ions [Cl(-)](0)/[Al(3+)](0) in the solution. Approximately 98% of the sulfate ions in the solution were removed within 10 min after adding 1.12 times the stoichiometric quantity of synthesized HT-Cl, which contained a Mg/Al molar ratio of 2 equal to a solution containing a 12 mM calcium sulfate solution.     

PrepHub Nepal

This article documents an action-research and collaborative-design process for building a disaster-prepared public space and water infrastructure in Thecho, Nepal. When the 2015 Gorkha earthquake devastated the country, public open spaces provided safety and resources post-disaster. The project identifies the paati, an existing public space typology, as the genius loci and embeds the paatis with new public infrastructure. Combining earthquake reconstruction, historical preservation, and risk reduction, the intervention provides improved daily water access and a safe space to gather post-disaster. Documenting and reflecting on this process illustrates the importance of ethnographic fieldwork and local partnerships in designing for a disaster-prepared public realm.     

Characterization and gas‐permeation properties of crosslinked diacetylene‐containing polymer membranes from ferulic acid

Thermally and UV crosslinked poly[propargyl(3‐methoxy‐4‐propargyloxy) cinnamate] (PPOF) were investigated in terms of their physical, thermal, optical, and gas‐permeation properties. The crosslinked membranes had high gel contents because of the formation of a diacetylene network. The wide‐angle X‐ray diffraction patterns showed that all of the membranes were amorphous in structure, regardless of the type of crosslinking reaction. The membrane density increased after the crosslinking reaction; this suggested that the free volume of the crosslinked membrane was lower than that of the untreated membranes. Drastic color changes in the membranes were also observed because of the highly conjugated crosslinked network of diacetylene. In addition, the conjugation caused by diacetylene crosslinking led to visible absorption within the range 400–600 nm. The gas permeation of the crosslinked membrane was reduced compared with that of the untreated membranes. In particular, the gas permeability of the thermally crosslinked membrane was lower than that of UV‐irradiated membrane. On the basis of this result, the degree of crosslinking by thermal treatment was higher than that of UV irradiation. Hence, the crosslinked PPOF membranes showed improved gas‐barrier properties due to the high conjugation of the crosslinked diacetylene network induced by thermal treatment and UV irradiation. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Thermal physiological response to local heating and cooling during sleep

For a healthy and productive life, good sleep is essential, which has prompted studies on how comfortable sleep can be achieved. Understanding the relationship between thermal environment and physiological responses such as skin and core temperatures, and psychological responses such as thermal and sleep sensations is necessary to identify the most suitable thermal environment for sleep. As an energy-saving and practical method of creating the most appropriate thermal environment for sleep, local heating or cooling is sometimes used, which takes into consideration the differences in local thermal responses. We performed this study to identify the most effective thermal environment for inducing comfortable sleep by identifying the physiological responses during sleep on the basis of sleep experiments conducted under local body heating or cooling conditions. We also used a human thermal model, which can be applied for predicting physiological responses.In the experiments, the feet of the subject were the primary area to be heated or cooled, which was achieved by installing a flexible duct with an outlet placed close to the subject's feet and inlet connected to an air conditioner. Differences in the fluctuation of body temperature and sleep stage depended on the airflow direction from the duct to the feet. When air was blown downward towards the feet, body temperature decreased and the subject was able to sleep well. Measured skin and core temperatures were calculated using an improved 27-node human thermal model that was originally developed for use in subjects who are not in sleep. Although skin temperature fluctuated significantly under local cooling, the results calculated using the proposed model agreed well with the measured results since the changes in heat conductance between the skin surface and surrounding environment as a result of the changes in the posture and feet position were taken into account. This result indicates that posture-associated changes in the heat conductance significantly influence skin temperature.     

Caspase inhibitors increase the rate of recovery of neural stem/progenitor cells from post-mortem rat brains stored at room temperature

To match the demand of regenerative medicine for nerve system, collection of stem cells from the post-mortem body is one of the most practical ways. In this study, the storage condition of the post-mortem body was examined. We prepared neural stem/progenitor cells (NSPCs) from post-mortem rat brains stored at different temperatures. When brains were stored at 4 °C, for one week, we were able to obtain neurospheres (a spheroid body containing NSPCs) by stimulation of cells with epidermal growth factor (EGF). Incremental increases in storage temperature decreased the rate of appearance of neurospheres. Within 48 h at 15 °C, 24 h at 25 °C, in both condition, we were able to recover NSPCs from post-mortem rat brains. At 15 °C, 90% of neurosphere-forming activity was lost within 24 h. However, even after 24 h at 25 °C, 2% neurosphere-forming activity remained. After 6 h of death, there was very little difference between the rates of NSPC recovery at 4 °C and 25 °C. Addition of caspase inhibitors to both the rat brain storage solution and the NSPC culture medium increased the rate of neurosphere-forming activity. In particular, an inhibitor of caspase-8 activity increased the NSPC recovery rate approximately three-fold, with no accompanying detrimental effects on neural differentiation in vitro.     

Thermal expansion of hydroxyapatite between − 100 °C and 50 °C

Hydroxy apatite (HAp) ceramic was synthesized using traditional sintering. Dilatometric and lattice thermal expansion properties of a HAp ceramic were evaluated at temperatures of ? 100–50 °C. In that temperature range, the dilatometric thermal expansion coefficient and the lattice thermal expansion coefficient of the HAp ceramic were, respectively, 10.6 × 10^? 6/°C and 9.9 × 10^? 6/°C. Furthermore, thermal expansion properties of a human tooth were measured. The thermal expansion coefficient of the horizontal direction perpendicular to the growing direction of a tooth was 15.5 × 10^? 6/°C; that of the vertical direction along with the direction of tooth growth was 18.9 × 10^? 6/°C at the temperature range described above.     

Polymerase chain reaction-denaturing gradient gel electrophoresis analysis of microbial community structure in landfill leachate

The structures of microbial communities in water samples obtained from a landfill site that had been a source of environmental pollution by emitting hydrogen sulfide were elucidated using polymerase chain reaction-denaturing gradient gel electrophoresis. The microbial communities, which consisted of a limited number of major microorganisms, were stable for several months. Microorganisms capable of degrading such chemical compounds as 2-hydroxybenzothiazole and bisphenol A were observed in landfill leachate. Microorganisms responsible for the production of hydrogen sulfide were not the primary microbes detected, even in water samples obtained from the site of gas emission.     

Enhanced in vivo responses of osteoblasts in electrostatically activated zones by hydroxyapatite electrets

Matured osteoblasts were proved to be located in the bone formation accelerated by induced large surface charges on the electrically polarized hydroxyapatite (HA) ceramics regardless of the charge polarities, whereas the spatial cell distribution patterns were different. Polarized HA ceramic plates with an average electric charge of 3.9 μCcm⁻² were implanted in widely spaced defects of canine femora for 3 and 7 days. The osteoblasts were identified by immunochemical detections of osteocalcin and osteopontin. Expressions of osteocalcin and osteopontin were detected throughout the gaps between the implanted HA plates and the cut cortical bone surfaces, especially in the vicinities of the cut cortical bone surfaces and the osteoids regardless of the polarity of the induced charges. Additionally, the newly formed bone tissue that directly bonded to the negatively charged HA surfaces was lined by an osteoblast layer. As soon as 7 days after the implantation, the presence of well-developed osteoblasts suggested that the electrostatic force of the HA ceramics had conditioned the field in the biointerface zone of the polarized HA surfaces.     

Antiulcerative properties of crude polyphenols and juice of apple,and Chinese quince extracts

Effects of Chinese quince extract, apple juice, semi-purified phenolics and soluble pectin from these fruits on ethanol-induced gastric ulcers in rats were investigated. In rats given Chinese quince extract or apple juice, ulcer induction was strongly suppressed, and the effect was stronger for Chinese quince extract than for apple juice. Myeloperoxidase activity in gastric mucosa showed a similar tendency. The DPPH radical scavenging activity and total phenolic content were 4 times higher in Chinese quince extract than in apple juice. Semi-purified phenolics from both fruits strongly suppressed ulcer induction at doses of 5–10 mg; however, a 20 mg dose of apple phenolics showed a pro-ulcerative effect. The soluble pectin fraction also showed moderate activity. These results suggest that phenolic compounds are responsible for antiulcerative activity of Chinese quince extract and apple juice, and that concentration may be an important factor in the case of apple phenolics.