高校トップレベル男子長距離走者のパフォーマンスと大腰筋の筋横断面積および最高酸素摂取量の関係

The purpose of this study was to examine the relationships between running performance and the cross–sectional area of the psoas major, peak oxygen uptake, and running economy in male junior long–distance runners. The subjects were 37 male junior athletes who achieved good records in interscholastic athletic competition during 5 years (2011–2015). Their seasonal best times in a 5,000 m race (5,000m–SB) were 14:04.11 ± 0:07.25 (13:53.64–14:16.15). In a multiple regression analysis, 5,000m–SB was statistical significantly correlated with the cross–sectional area of psoas major (16.0 ± 1.7 cm2) measured on magnetic resonance imaging and peak oxygen uptake (4.25 ± 0.36 l min-1 [76.9 ± 5.8 ml min-1 kg-1]) during a lactate curve test comprising five stages. However, 5,000m–SB was not related to oxygen uptake at the work–load which was less than the load at the lactate threshold estimated by using the lactate curve test results. These results suggest that a high volume of the psoas major, the largest hip–flexor muscle, and peak oxygen uptake are among the important factors for junior long–distance runner performance

A dehydrated space-weathered skin cloaking the hydrated interior of Ryugu

Without a protective atmosphere, space-exposed surfaces of airless Solar System bodies gradually experience an alteration in composition, structure and optical properties through a collective process called space weathering. The return of samples from near-Earth asteroid (162173) Ryugu by Hayabusa2 provides the first opportunity for laboratory study of space-weathering signatures on the most abundant type of inner solar system body: a C-type asteroid, composed of materials largely unchanged since the formation of the Solar System. Weathered Ryugu grains show areas of surface amorphization and partial melting of phyllosilicates, in which reduction from Fe3+ to Fe2+ and dehydration developed. Space weathering probably contributed to dehydration by dehydroxylation of Ryugu surface phyllosilicates that had already lost interlayer water molecules and to weakening of the 2.7 µm hydroxyl (–OH) band in reflectance spectra. For C-type asteroids in general, this indicates that a weak 2.7 µm band can signify space-weathering-induced surface dehydration, rather than bulk volatile loss

Perilla Oil, An Omega-3 Unsaturated Fatty Acid-Rich Oil, Enhances Diversity of Gut Microbiota and May Relieve Constipation in Sedentary Healthy Female: A Nonrandomized Placebo-Controlled Pilot Study

This study shows the effect of omega-3 unsaturated fatty acids via perilla oil intake on gut microbiota and constipation. Eight sedentary females participated in a nonrandomized placebo-controlled pilot study consisting of eight-week perilla oil (OIL) and placebo (PLA) intervention phases. There was a 10-month washout period between phases. All participants received 9 g of perilla oil-containing jelly in the OIL phase, and a placebo jelly in the PLA phase. Gut microbiota, α-diversity, and constipation scores were measured pre- and post-intervention in both phases. The α-diversity, an important indicator of gut microbiota diversity, was significantly increased post-intervention (4.5 ± 0.1) compared to pre-intervention (3.8 ± 0.3) in the OIL only (p = 0.021). Notably, the level of α-diversity was maintained even after the washout period of 10 months. Butyrate-producing bacteria, Lachnospiraceae (%), did not change in the OIL but were significantly reduced post-intervention (15.1 ± 4.8) compared to pre-intervention (20.1 ± 7.0) in the PLA (p = 0.040). In addition, the constipation scores were significantly or tended to be reduced during the OIL phase only (p p < 0.1). In conclusion, an eight-week perilla oil supplementation may enhance and establish the diversity of gut microbiota, which may relieve constipation

Equalization of the Occlusal State by Wearing a Mouthguard Contributes to Improving Postural Control Function

The aim of this study was to clarify the effect on the postural control function of equalizing the occlusal contact state by wearing a mouthguard. Method: Participants included 23 untrained adults, 11 gymnasts, and 10 weightlifters. Custom mouthguards were fabricated and adjusted so that all teeth were in even contact with light clenching. The standing postural control function was evaluated by the displacement of the center of foot pressure (COP) measured using a gravity center fluctuation meter. Measurement conditions were with and without a mouthguard. Statistical analyses were performed on the differences in COP displacement among participant groups and between mouthguard conditions and the difference in the reduction rate of COP displacement when wearing a mouthguard among participant groups. Results: COP significantly decreased in the order of untrained adults to weightlifters to gymnasts, irrespective of the mouthguard condition. The reduction rate in COP displacement after wearing a mouthguard was greatest in gymnasts. Conclusions: The effect of the mouthguard on postural control function was more pronounced in gymnasts than in untrained adults and weightlifters, and this study suggests that equalization of the occlusal state by wearing a mouthguard contributes to improving postural control function

Similarity scores of vibrational spectra reveal the atomistic structure of pentapeptides in multiple basins

Vibrational spectroscopy combined with theoretical calculations is a powerful tool to reveal the interaction and conformation of peptides at the atomistic level. Despite the advances in experimental techniques, theoretical calculations have become increasingly challenging as the molecule of interest grows complex. Here, we propose a novel conformational search method, which exploits the structure-spectrum correlation using a similarity score that quantifies the agreement of theoretical and experimental spectra. The method reveals the atomistic structure of two conformers of a capped penta-peptide, acetyl-SIVSF-N-methylamine, which has remained unknown since its first observation [Angew. Chem. Int. Ed. 2018, 57, 5626]. Although one of the conformers is assigned to the lowest-energy conformer, the other one is found to be 25 kJ mol-1 higher in energy with distinctly different geometry. The result suggests multiple pathways in the early stage of the folding process; one to the global minimum and the other to a different basin. Once such a structure is formed, the second conformer hardly overcomes the barrier to produce the most stable structure due to a vastly different hydrogen bond network of the backbone. The proposed method can characterize not only the lowest-energy conformer but also kinetically trapped, high-energy conformers of complex biomolecules