Local structure analysis of NaNiO2 by EXAFS Wakita, Takanori; Mitsuoka, Takumi; Simonelli, Laura ...
Meeting Abstracts of the Physical Society of Japan,
2020
Journal Article
The effects of exercise training have never been investigated in centenarians. This single-subject research study aimed to assess the effects of a structured training protocol on functional ...capacities in a centenarian master athlete. A 99.5 years old male subject participated in the study. Before and after a 16-month training intervention the participant underwent a test battery for flexibility (YMCA sit and reach), balance (single leg stance), upper limb strength (hand grip and pinch strength), and lower limb power (counter movement jump) and muscular endurance (horizontal leg press with 85 kg load). After training, sit and reach (-3 cm) and counter movement jump (- 0.5 cm) scores decreased, whereas single leg stance (+1.3 s), left hand grip (+2.0 kg), right hand pinch (+ 0.5 kg), and horizontal leg press (+2 repetitions) scores increased. Right hand grip strength and left-hand pinch strength did not change after training. When pre- and post-training scores were compared to gender-matched normative values, flexibility resulted well below average, maybe because of a relatively broad age category (> 65 years). When more specific age categories were available, the participant’s balance resulted slightly below average (age category 80-99 years) and upper limb strength above average (age category > 85 years). No normative values were found for lower limb power and muscular endurance. In conclusion, this study highlights that structured exercise training may play a role in maintaining – and even in increasing – functional capacities in the oldest old age.
Physical activity (PA) has health benefits for people with type 2 diabetes (T2D). Indeed, regular PA is considered an important part of any T2D management plan, yet most patients adopt a sedentary ...lifestyle. Exercise referral schemes (ERS) have the potential to effectively promote physical activity among T2D patients, and their effectiveness may be enhanced when they are supported by computer-based technologies. The 'TRIPL-A' study (i.e., a TRIal to promote PhysicaL Activity among patients in the young-old age affected by T2D) aims to assess if realizing an innovative ERS, based on a strong partnership among general practitioners, specialist physicians, exercise specialists, and patients, and supported by a web-based application (WBA), can effectively lead sedentary older T2D patients to adopt an active lifestyle.
A randomized controlled design will be used, and an ERS, supported by a WBA, will be implemented. 300 physically inactive T2D patients (aged 65-74 years) will be assigned to either an intervention or control arm. Control arm patients will only receive behavioral counseling on physical activity and diet, while intervention arm patients will also undergo an 18-month (3 day/week), discontinuously supervised aerobic exercise training program. The trial will be divided into six three-month periods: during first, third and fifth period, an exercise specialist will supervise the training sessions and, using the WBA, prescribe exercise progression and monitor exercise adherence. Patients will exercise on their own in the other periods. Patients' sedentary behaviors (primary outcome), PA level, fitness status, metabolic profile, psychological well-being, quality of life, and use of health care services (secondary outcomes) will be assessed at baseline and at 6, 12, and 18 months from baseline. Repeated measure ANCOVAs will be used to compare the intervention and control arm with respect to each study outcome measure.
Primary and secondary outcome results will allow us to evaluate the effectiveness of an ERS, specifically designed for the management of T2D clinical conditions and supported by a WBA, in promoting PA within Italian primary care settings.
This trial is retrospectively registered under the Australian New Zealand Clinical Trials Registry (reference number: ACTRN12618001164280 ; registered 13 July 2018).
Controlling product distribution in CO2 hydrogenation is of great scientific interest, the selective CO production through the reverse water-gas shift reaction (RWGS) being one of the most ...investigated processes. Herein, we report the synthesis of new core-shell Co@Ni NPs encapsulated in carbon (Co@Ni@C) to prevent their aggregation at the high-temperatures reached during magnetically induced catalysis. This bifunctional system has been simultaneously used as heating agent and catalyst for the magnetically induced hydrogenation of CO2. While at low magnetic fields Co@Ni@C produces CH4:CO mixtures, at higher field amplitudes it selectively generates carbon monoxide. Indeed, Co@Ni@C has shown to be one of the most active catalysts reported to date, which reaches a maximum conversion of 74.2% with complete selectivity towards CO at 53 mT and 300 kHz. In addition, recycling and cyclability experiments have demonstrated that Co@Ni@C becomes fully selective for CO after being exposed to high field amplitudes (i.e. reaction temperature above 500 °C), even when it exposed to low magnetic fields again. This change in the selectivity is due to an atomic rearrangement of the core-shell structure, as was confirmed by EDX, XAS, TPR and TPD analysis.
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•Core-shell Co@Ni NPs encapsulated in carbon (Co@Ni@C) have been used as catalyst for magnetically induced CO2 hydrogenation•While at low magnetic fields Co@Ni@C produces CH4:CO mixtures, at higher fields it selectively generates CO•Co@Ni@C reaches a maximum conversion of 74.2% with complete selectivity towards CO at 53 mT•Co@Ni@C becomes fully selective to CO after the first catalytic cycle due to an atomic rearrangement of the core-shell structure
Aim
Selenium (Se) can induce stress in plants. Our main purpose is to assess the effect of a biostimulant, based on hetero-polyoxometalates mixed with humic acids, on Se bio-fortified wheat plants. ...Secondly, to evaluate a possible modification of the Se species in the plant tissues and to investigate the response of phytohormones.
Method
Wheat plants were grown hydroponically and exposed to either selenite (Se(IV)), selenate (Se(VI)) or a mixture of both species (Se(MIX)) in the presence or absence of the biostimulant (foliar, FA; or root application, RA). Biomass, mineral nutrient concentration, phytohormones and Se speciation were investigated.
Results
The biostimulant FA did not modify the plant biomass but RA significantly increased the root biomass in all treatments as well as the shoot biomass of plants exposed to Se(VI) and Se(MIX) even when both modes of application caused a severe reduction of IAA levels in shoots. The biostimulant accelerated the translocation of Se from roots to shoots in the presence of Se(VI) and Se(MIX), and it only had a noticeable influence on the Se speciation in roots, but not significant in shoots. X-ray absorption spectroscopy allowed to identify organic Se as the main Se species formed in the shoots. The biostimulant has a mild effect on the Se speciation.
Conclusion
The biostimulant has a remarkable influence on both the uptake and accumulation of certain mineral nutrients and the plant metabolism by increasing the biomass under Se exposure. This indicates the potential of this biostimulant that also will prevent the possible Se-induced plant stress.
A frontier challenge in single‐atom (SA) catalysis is the design of fully inorganic sites capable of emulating the high reaction selectivity traditionally exclusive of organometallic counterparts in ...homogeneous catalysis. Modulating the direct coordination environment in SA sites, via the exploitation of the oxide support's surface chemistry, stands as a powerful albeit underexplored strategy. We report that isolated Rh atoms stabilized on oxygen‐defective SnO2 uniquely unite excellent TOF with essentially full selectivity in the gas‐phase hydroformylation of ethylene, inhibiting the thermodynamically favored olefin hydrogenation. Density Functional Theory calculations and surface characterization suggest that substantial depletion of the catalyst surface in lattice oxygen, energetically facile on SnO2, is key to unlock a high coordination pliability at the mononuclear Rh centers, leading to an exceptional performance which is on par with that of molecular catalysts in liquid media.
Engineering the direct metal coordination environment in single‐atom catalysts, via adjustment of the oxide surface chemistry, is a powerful strategy towards reactivity modulation. An energetically facile depletion of surface oxygen on a Rh1/SnO2 catalyst unlocks an exceptional performance in the gas‐phase hydroformylation of ethylene with syngas, hitherto exclusive of molecular catalysts operating in liquid environments.
In this report, we have used the DFT + U + V approach, an extension of the DFT + U approach that takes into account both on-site and intersite interactions, to simulate structural, magnetic, and ...electronic properties together with the Fe and O K-edge XAS spectra of Fe3O4 above the Verwey temperature (T v). Moreover, we compared the simulated XAS spectra with experimental XAS data. We examined both orthogonalized and nonorthogonalized atomic orbital projectors and compared DFT + U + V to DFT, DFT + U, and HSE as a hybrid functional. It is noteworthy that, despite the widespread use of the same Hubbard U value for Feoct and Fetet at the DFT + U level in the literature, the HP code identified two distinct values for them using the Hubbard approaches (DFT + U and DFT + U + V). The resulting Hubbard U and V parameters are strongly dependent on the chosen orbital projectors. This study demonstrates how DFT + U + V can improve the structural, magnetic, and electronic properties of Fe3O4 compared to approximate DFT and DFT + U. In this context, DFT + U + V supports the half-metallic character of the bulk crystal Fe3O4 above T v, since the Fermi level is found in the t2g band with a Feoct down-spin. Thus, the observations in the current study emphasize the significance of intersite interactions in the theoretical analysis of Fe3O4 above the T v.
Here we address the challenging problem of pressure induced hydrogen sublattice disordering in layered hydroxides using synchrotron X-ray powder diffraction (XRPD) and first-principles calculations ...based on density functional theory (DFT) using β-Ni(OH)2 as a model system. XRPD data demonstrate anomalous behaviors in some Bragg peaks. The shift in (003) and (013) peaks with pressure is large as compared to that of other Bragg peaks and these two peaks are not discernible above 5 GPa, similar to the characteristic observed in β-Co(OH)2. The underlying changes within the structure were probed using DFT calculations on a √3 × √3 × 1 supercell of β-Ni(OH)2. Structural relaxation yields a hydrogen disordered structure as the ground state for β-Ni(OH)2 at pressures above 5 GPa. The disordered model also describes well the high pressure XRPD data. The hydrogen sublattice largely affects the electronic density of the (003) and (013) lattice planes thus permitting the development of a one-to-one correspondence of the anomalous behavior of these Bragg peaks with the hydrogen sublattice disordering. Further evidence of a possible structural rearrangement was obtained by the pressure dependence of the unit-cell volume (P vs V) as well as the ratio of the out-of-plane to in-plane lattice parameter (c/a). With the availability of a large number of data points with smaller pressure steps, the above two quantities are shown to behave differently below and above 2.5 GPa. The P vs V data are well described by a second order Birch–Murnaghan equation-of-state, whereas for c/a, a clear change in trend is observed for data above 2.5 GPa. The pressure response of β-Ni(OH)2 is similar to that of Co(OH)2 reported in our recent high pressure study, and therefore pressure induced hydrogen order–disorder transition may be a general characteristic of layered hydroxides.
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