Effect of forearm positions on scapular movements and trunk rotation angles.

[Purpose] The study investigated the impact of distinct forearm positions on scapular movement and trunk rotation angles. [Participants and Methods] We enrolled 23 healthy young males. Measurements of trunk rotation and relative scapular segment angles were acquired under three conditions employing three-dimensional motion analysis, each executed in a seated posture: (1) both forearms in a neutral position, (2) the forearm on the rotational side adopted supination while the opposite forearm utilized pronation, and (3) the forearm on the rotational side employed pronation while the opposite forearm assumed supination. [Results] The scapular angles in all three scenarios reflected downward rotation, posterior tilt, and external rotation of the rotational-side scapula. Conversely, the contralateral scapula exhibited upward rotation, anterior tilt, and internal rotation. Although the scapular and trunk rotation angles corresponded with the three forearm positions, all three were significantly different and were significantly increased when the rotational-side forearm was in supination (opposite side pronation) and decreased when the rotational-side forearm was in pronation (opposite side supination). [Conclusion] During trunk rotation, regular scapular movements were observed, which varied depending on forearm position and influenced the range of trunk rotation.

Experimental confirmation of the Badger-Bauer rule in the protonated methanol clusters: weak hydrogen bond formation as a measure of terminal OH acidity in hydrogen bond networks.

We report a linear correlation between the OH stretch frequency shift of the protonated methanol cluster, H+(MeOH)n, upon the π-hydrogen bond formation with benzene and the enthalpy change in clustering of H+(MeOH)n to H+(MeOH)n+1. This result suggests a new method to explore hydrogen bond strength in hydrogen bond networks.

Infrared Spectroscopy of (Benzene-H2S-Xn)+, X = H2O (n = 1 and 2) and CH3OH (n = 1), Radical Cation Clusters: Microsolvation Effects on the S-π Hemibond.

An unconventional covalent bond in which three electrons are shared by two centers is called hemibond. Hemibond formation frequently competes with proton transfer (or ionic hydrogen bond formation), but there have been a few experimental reports on such competition. In the present study, we focus on the (benzene-H2S)+ radical cation cluster, which is a model system of the S-π hemibond. The stability of the S-π hemibond to the microsolvation by water and methanol is explored with infrared spectroscopy of (benzene-H2S-Xn)+, X = H2O (n = 1 and 2) and CH3OH (n = 1), clusters. We also perform energy-optimization and vibrational simulations of (benzene-H2S-Xn)+. By comparison among the observed and simulated spectra, we determine the intermolecular binding motifs in (benzene-H2S-Xn)+. While the S-π hemibonded isomer is exclusively populated in (benzene-H2S-H2O)+, both the hemibonded and proton-transferred isomers coexist in [benzene-H2S-(H2O)2]+ and (benzene-H2S-CH3OH)+. Breaking of the S-π hemibond by the microsolvation is observed, and its solvent and cluster size dependence is interpreted by the proton affinity and the coordination property of the solvent moiety.

Synthesis and Reactivity of Manganese Complexes Bearing Anionic PNP- and PCP-Type Pincer Ligands toward Nitrogen Fixation.

A series of manganese complexes bearing an anionic pyrrole-based PNP-type pincer ligand and an anionic benzene-based PCP-type pincer ligand is synthesized and characterized. The reactivity of these complexes toward ammonia formation and silylamine formation from dinitrogen under mild conditions is evaluated to produce only stoichiometric amounts of ammonia and silylamine, probably because the manganese pincer complexes are unstable under reducing conditions.

How many methanol molecules effectively solvate an excess proton in the gas phase? Infrared spectroscopy of H+(methanol)n-benzene clusters.

An excess proton in a hydrogen-bonded system enhances the strength of hydrogen bonds of the surrounding molecules. The extent of this influence can be a measure of the number of molecules effectively solvating the excess proton. Such extent in methanol has been discussed by the observation of the π-hydrogen-bonded OH stretch bands of the terminal sites of protonated methanol clusters, H+(methanol)n, in benzene solutions, and it has been concluded that ∼8 molecules effectively solvate the excess proton (Stoyanov et al., Chem. Eur. J. 2008, 14, 3596-3604). In the present study, we performed infrared spectroscopy of H+(methanol)n-benzene clusters in the gas phase. The cluster size and hydrogen-bonded network structure are identified by the tandem mass spectrometric technique and the comparison of the observed infrared spectra with density functional theory calculations. Though changes of the preferred hydrogen bond network type occur with the increase of cluster size in the gas phase clusters, the observed size dependence of the π-hydrogen bonded OH frequency agrees well with that in the benzene solutions. This means that the observations in both the gas and condensed phases catch the same physical essence of the excess proton solvation by methanol.

Nordic Walking Increases Distal Radius Bone Mineral Content in Young Women.

Unlike the lumbar spine and femur, the radius does not bear a gravitational mechanical compression load during daily activities. The distal radius is a common fracture site, but few studies have addressed the effects of exercise on fracture risk. The aim of this study was to determine the effects of the pole push-off movement of Nordic walking (NW) on the bone mineral content (BMC) and areal bone mineral density (aBMD) of the distal radius and the muscle cross-sectional area (CSA) at the mid-humeral and mid-femoral levels. The participants were allocated to two groups: an NW group and a control group. The NW group walked at least 30 min with NW poles three times a week for six months. There were no significant changes in muscle CSA at the mid-humeral or mid-femoral levels between or within groups. There were also no significant changes in BMC or aBMD at 1/3 and 1/6 of the distance from the distal end of the radius in either group. However, the BMC and aBMD at 1/10 of the distance from the distal end of the radius were significantly increased by NW. The NW pole push-off movement provided effective loading to increase the osteogenic response in the ultra-distal radius. The ground reaction forces transmitted through the poles to the radius stimulated bone formation, particularly in the ultra-distal radius.

Catalytic C-H Borylation Using Iron Complexes Bearing 4,5,6,7-Tetrahydroisoindol-2-ide-Based PNP-Type Pincer Ligand.

Catalytic C-H borylation has been reported using newly designed iron complexes bearing a 4,5,6,7-tetrahydroisoindol-2-ide-based PNP pincer ligand. The reaction tolerated various five-membered heteroarenes, such as pyrrole derivatives, as well as six-membered aromatic compounds, such as toluene. Successful examples of the iron-catalyzed sp3 C-H borylation of anisole derivatives were also presented.

Hydroboration of Alkynes Catalyzed by Pyrrolide-Based PNP Pincer-Iron Complexes.

To utilize iron complexes as catalysts, the application of a well-designed ligand is critical to control the reactivity of the iron center. Recently, our group has succeeded in the synthesis of iron complexes bearing a pyrrolide-based PNP pincer ligand and their application to the catalytic transformation of dinitrogen into ammonia under mild reaction conditions. As an extensive study, we report the iron-catalyzed hydroboration of alkynes with pinacolborane, where the corresponding E-isomers are obtained selectively.

[Effect of exercise and sports activity on bone health during the period of adolescence to young adulthood.]

Physical activity may play an important role in maximizing bone mass during adolescence to young adulthood and may have long-lasting benefits on bone health. Because peak bone mass is thought to be attained by the end of the third decade, the early adult years may be the final opportunity for its augmentation. High-impact weight-bearing exercise during youth may provide lifelong benefits in terms of bone mineral content, structure and strength, and consequently reduce fracture risk. Weight-bearing exercise in youth affects bone, and these effects may be preserved as BMC, geometric and structural advantages even after 40 years. In order to evaluate the bone strength enhanced by the exercise and sporting activity, not only measuring the BMD by DXA but also the cross sectional geometric bone analysis may clarify the further contributions.

Past sporting activity during growth induces greater bone mineral content and enhances bone geometry in young men and women.

We aimed to determine the effect of past sporting activity on bone mineral content (BMC), areal bone mineral density (aBMD) in the lumbar spine and proximal femur, and bone geometry of the mid femur in young men and women. We assessed 142 subjects, comprising 79 young men (21.2 ± 0.8 years) and 63 premenopausal young women (21.4 ± 0.6 years). The subjects were classified into three groups, two on the basis of the age of starting to participate in sport [elementary school starters (6-12 years), junior high school to university starters (13-22 years)], and the third group had no participation in sport. We measured BMC and aBMD by dual-energy X-ray absorptiometry (DXA) in the lumbar spine and proximal femur, and bone geometric characteristics of the mid femur by magnetic resonance imaging (MRI), and calculated the osteogenic index (OI) of previous sporting activity. The OI correlated significantly with many MRI-determined measures of bone geometry; DXA-measured BMC and aBMD were effective indicators of previous sporting activity in both sexes. The female elementary school starters had significantly greater femoral mid-diaphyseal perimeters (vs the no-sport group), bone cross-sectional area (vs the 13-22-year-old starters and the no-sport group), and maximum and minimum second moment of area at the mid-diaphysis point of the femur (vs the no-sport group). The OI is a proven practicable and useful index. DXA- and MRI-determined geometric characteristics showed that high-impact, weight-bearing exercise before and in early puberty induces greater total proximal femur BMC and enhances femoral mid-diaphyseal size and shape, and that these benefits persisted in young adult women.

Bones benefits gained by jump training are preserved after detraining in young and adult rats.

We investigated the osteogenic responses to jump training and subsequent detraining in young and adult male rats to test the following hypotheses: 1) jump training has skeletal benefits; 2) these skeletal benefits are preserved with subsequent detraining throughout bone morphometric changes; and 3) there are no differences between young and adult rats during detraining in terms of the maintenance of exercise-induced changes. Twelve-week-old (young) and 44-wk-old (adult) rats were divided into the following four groups: young-sedentary, young-exercised, adult-sedentary, and adult-exercised. The exercised groups performed jump training (height = 40 cm, 10 jumps/day, 5 days/wk) for 8 wk followed by 24 wk of being sedentary. Tibial bone mineral content and bone mineral density in vivo significantly increased with jump training, and the effects were maintained after detraining in both the young and adult exercised groups, although the benefits of training became somewhat diminished. After 24 wk of detraining, the beneficial effects of training on bone mass and strength were preserved and associated with morphometric changes, such as periosteal perimeter, cortical area, and moment of inertia. There were no significant age-exercise interactions in such parameters, except for the periosteal perimeter. These results suggest that there are few differences in bone accommodation and maintenance by training and detraining between young and adult rats.

Effect of low-repetition jump training on bone mineral density in young women.

The hypothesis of the present study was that low-repetition and high-impact training of 10 maximum vertical jumps/day, 3 times/wk would be effective for improving bone mineral density (BMD) in ordinary young women. Thirty-six female college students, with mean age, height, and weight of 20.7+/-0.7 yr, 158.9+/-4.6 cm, and 50.4+/-5.5 kg, respectively, were randomly divided into two groups: jump training and a control group. After the 6 mo of maximum vertical jumping exercise intervention, BMD in the femoral neck region significantly increased in the jump group from the baseline (0.984+/-0.081 vs. 1.010+/-0.080 mg/cm2; P<0.01), although there was no significant change in the control group (0.985+/-0.0143 vs. 0.974+/-0.134 mg/cm2). And also lumbar spine (L2-4) BMD significantly increased in the jump training group from the baseline (0.991+/-0.115 vs. 1.015+/-0.113 mg/cm2; P<0.01), whereas no significant change was observed in the control group (1.007+/-0.113 vs. 1.013+/-0.110 mg/cm2). No significant interactions were observed at other measurement sites, Ward's triangle, greater trochanter, and total hip BMD. Calcium intakes and accelometry-determined physical daily activity showed no significant difference between the two groups. From the results of the present study, low-repetition and high-impact jumps enhanced BMD at the specific bone sites in young women who had almost reached the age of peak bone mass.