Visual observations of the effect of surfactants on clathrate hydrate crystal growth at the interface of water and cyclopentane has been studied. Surfactants used in the present study are sorbitan monooleate (Span 80), naphthenic acid, and polypropylene glycol. The surfactants were each used at a mass fraction of 0.001% and 0.01%. All the surfactants were soluble in cyclopentane. The crystalline morphology and crystal growth behavior of the hydrate at the interface were found to be substantially affected by the addition of all surfactants. The size of the individual hydrate crystals in the surfactant system was larger than those in the pure cyclopentane system. The observations showed a distinct variation in the behavior of cyclopentane hydrate crystal growth depending on the chemical species of the surfactants, their concentration, and ΔT sub , which is defined as the difference between the equilibrium temperature and the experimental temperature. For the system with surfactants, the growing hydrate crystals did not engulf the interface, because the crystal grains that have grown detached from the interface and fallen into the water. From the observations, it is clear that hydrate crystal production increased in comparison to systems without surfactants due to the interface area being preserved. These observations explain the physical mechanism of two surfactant effects, where one is the prevention of hydrate agglomeration (interface area preservation) and the other is the promotion of hydrate production.

This paper presents visual observations aiming to clarify the underlying physics of surfactant effects on clathrate hydrate crystal growth at the interface between methane gas and water with surfactant. Sodium dodecyl sulfate (SDS), which is commonly used in industrial processes, was used in this study. Various SDS mass fractions from 0 to w SDS = 100 ppm with a step of size 10 ppm were examined, where w SDS represents the mass fraction of SDS aqueous solution. The crystal growth behavior and the crystal morphology of the methane hydrate at the interface varied depending on surfactant concentration and ΔT sub. In systems with w SDS ≤ 20 ppm, the nucleation occurred on the droplet surface (gas/liquid interface), then grew laterally, and finally covered the whole droplet surface. On the contrary, at w SDS ≥ 30 ppm, the droplet shape was not maintained and enhanced hydrate crystal growth was observed compared to those systems with w SDS ≤ 20 ppm. Individual hydrate crystals at w SDS = 20 ppm were observed to be smaller than those in a pure water system at a given ΔT sub, which is ascribed to the enhanced hydrate nucleation by the addition of SDS.

The Dietary Approaches to Stop Hypertension (DASH) diet is recommended by the American Heart Association to lower blood pressure (BP); however, its effects in Japanese participants have not been rigorously studied. We assessed the effects of the DASH-Japan Ube Modified diet Program (DASH-JUMP), a modified DASH diet, on cardiometabolic and inflammatory biomarkers in Japanese participants with untreated high-normal BP or stage 1 hypertension. Fifty-eight participants (30 men and 28 women; mean age 54.1±8.1 years) with untreated high-normal BP or stage 1 hypertension followed the DASH-JUMP (salt 8.0 g per day) for 2 months. After the intervention period, they resumed their usual diets for 4 months. The DASH-JUMP significantly decreased the participants' body mass index values (24.6±3.5 kg m−2 at baseline→23.2±3.3 kg m−2 at 2 months, P=0.000), BP (153±14/91±11 mm Hg at baseline→130±16/80±9 mm Hg at 2 months, P=0.000 and 139±16/85±10 mm Hg at 6 months, P=0.000), fasting serum glucose level (100±26 mg dl−1→94±15 mg dl−1 at 2 months, P=0.003) and fasting insulin level (6.9±5.9 μIU ml−1→4.4±2.7 μIU ml−1 at 2 months, P=0.000). The mean compliance of the participants for the DASH-JUMP diet was 88.5%. The DASH-JUMP diet reduced cardiovascular risk factors and may be an effective nutritional strategy for preventing cardiovascular events.

A DNA/protamine complex powder was prepared by reaction between DNA and protamine sulfate solution with stirring in order to develop a new injectable biomaterials for dental therapy. The powder of DNA/protamine complex became paste by kneading the complex powder and distilled water. Complex formation was confirmed by FT-IR measurement. The complex paste had a porous structure and its viscosity was approximately 280.1 Pas. The paste could easily pass through a needle of 0.25 mm internal diameter. It seemed that DNA/protamine complex paste has suitable viscosity for clinical use as an injectable biomaterial. Although, the complex paste delayed the growth speed of Staphylococcus aureus, Pseudomonas aeruginosa, Porphyromonas gingivalis and Prevotella intermedia for limited periods, it cannot kill and inhibit growing bacteria. The complex paste disk showed a mild tissue response and gradually degraded after the implantation into the soft tissue of rats. These results suggested that this DNA/protamine complex paste could be a useful material for a biodegradable biomaterial. In particular, this paste will be applicable as an injectable biomaterial using syringe for the repair of defects of living tissue, GBR treatment and/or GTR treatment in dentistry.

Several studies have reported that short sleep duration is a risk factor for obesity and metabolic disease. Moreover, both sleep duration and sleep timing might independently be associated with dietary nutrient intake. In this study, we investigated the associations between self-reported sleep duration and dietary nutrient intake, with and without adjustments for variations in sleep timing (i.e., the midpoint of sleep). We conducted a questionnaire survey, comprising a validated brief self-administered diet history questionnaire (BDHQ) and the Japanese version of the Pittsburgh Sleep Quality Index (PSQI) among 1902 healthy Japanese adults and found that the dietary intakes of several nutrients correlated with sleep duration among men regardless of adjustment for the midpoint of sleep. Particularly, (1) small but significant correlations were observed between sleep duration and the percentage of energy from protein, regardless of adjustment for the midpoint of sleep; (2) energy-adjusted intakes of sodium, vitamin D, and vitamin B12 also significantly correlated with sleep duration; and (3) intakes of bread, pulses, and fish and shellfish correlated with sleep duration. In contrast, no significant correlations were observed between sleep duration and dietary intakes among women. This study revealed that after controlling for the midpoint of sleep, sleep duration correlated significantly with the dietary intake of specific nutrients and foods in a population of Japanese men.