Optimizing Rehabilitation Outcomes for Stroke Survivors: The Impact of Speed and Slope Adjustments in Anti-Gravity Treadmill Training.

Background and Objectives: This study explored the efficacy of customized anti-gravity treadmill (AGT) training, with adjustments in speed and incline, on rehabilitation outcomes for stroke patients, focusing on knee extensor muscle strength, joint angle, balance ability, and activities of daily living (ADLs). Materials and Methods: In this study, 30 individuals diagnosed with a stroke were divided into three groups. Experimental group 1 (EG1) underwent training without changes to speed and incline, experimental group 2 (EG2) received training with an increased incline, and experimental group 3 (EG3) underwent training with increased speed. Initially, all participants received AGT training under uniform conditions for two weeks. Subsequently, from the third to the sixth week, each group underwent their specified training intervention. Evaluations were conducted before the intervention and six weeks post-intervention using a manual muscle strength tester for knee strength, TETRAX for balance ability, Dartfish software for analyzing knee angle, and the Korean version of the Modified Barthel Index (K-MBI) for assessing activities of daily living. Results: Within-group comparisons revealed that AGT training led to enhancements in muscle strength, balance ability, joint angle, and ADLs across all participant groups. Between-group analyses indicated that EG2, which underwent increased incline training, demonstrated significant improvements in muscle strength and balance ability over EG1. EG3 not only showed significant enhancements in muscle strength, joint angle, and ADLs when compared to EG1 but also surpassed EG2 in terms of knee strength improvement. Conclusions: In conclusion, the application of customized AGT training positively impacts the rehabilitation of stroke patients, underscoring the importance of selecting a treatment method tailored to the specific needs of each patient.

Polymorphism and phase transitions in Na2U2O7 from density functional perturbation theory.

Polymorphism and phase transitions in sodium diuranate, Na2U2O7, are investigated with density functional perturbation theory (DFPT). Thermal properties of crystalline α-, ß- and γ-Na2U2O7 polymorphs are predicted from DFPT phonon calculations, i.e., the first time for the high-temperature γ-Na2U2O7 phase (R3̄m symmetry). The standard molar isochoric heat capacities predicted within the quasi-harmonic approximation are for P21/a α-Na2U2O7 and C2/m ß-Na2U2O7, respectively. Gibbs free energy calculations reveal that α-Na2U2O7 (P21/a) and ß-Na2U2O7 (C2/m) are almost energetically degenerate at low temperature, with ß-Na2U2O7 becoming slightly more stable than α-Na2U2O7 as temperature increases. These findings are consistent with XRD data showing a mixture of α and ß phases after cooling of γ-Na2U2O7 to room temperature and the observation of a sluggish α → ß phase transition above ca. 600 K. A recently observed α-Na2U2O7 structure with P21 symmetry is also shown to be metastable at low temperature. Based on Gibbs free energy, no direct ß â†’ γ solid-solid phase transition is predicted at high temperature, although some experiments reported the existence of such phase transition around 1348 K. This, along with recent experiments, suggests the occurrence of a multi-step process consisting of initial ß-phase decomposition, followed by recrystallization into γ-phase as temperature increases.

The Effects of Shock Wave Therapy on Spasticity and Walking Ability in People with Stroke: A Comparative Study of Different Application Sites.

BACKGROUND: This study was conducted to investigate the effects of extracorporeal shock wave therapy on the improvement of walking ability through a reduction in spasticity in stroke patients. METHODS: Thirty-three patients diagnosed with ischemic stroke by a rehabilitation medicine specialist were randomly assigned to three groups. The patients were divided into experimental group 1 in which shock waves were applied to the muscle-tendon junction, experimental group 2 in which shock waves were applied to the middle of the muscle, and experimental group 3 in which shock waves were applied to both the muscle-tendon junction and the middle of the muscle. The MAS was used to evaluate spasticity in the subjects, and the Dartfish software was used to measure knee and ankle angles during heel-off when walking. RESULTS: Based on the results of the study, a significant decrease in spasticity and increased joint angles were found in experimental groups 1 and 3 compared to experimental group 2, and the change in joint angle was significantly greater in experimental group 3 than in experimental groups 1 and 2. CONCLUSIONS: These results indicate that treatment effect may vary depending on the application site of the shock wave, and to obtain the best treatment effect, the shock wave should be applied to both the muscle-tendon junction and the middle part of the muscle.

The Effect of Diagonal Exercise Training for Neurorehabilitation on Functional Activity in Stroke Patients: A Pilot Study.

Functional movements of the human body occur multifacetedly. This pilot study investigated the effects of neurorehabilitation training, including diagonal movements, balance, gait, fall efficacy, and activities of daily living in stroke patients. Twenty-eight patients diagnosed with stroke by a specialist were divided into experimental groups applying diagonal exercise training and control groups applying sagittal exercise training. The five times sit-to-stand test (FTSST), timed up and go (TUG) test, and Berg balance scale (BBS) were used to evaluate balance ability, the falls efficacy scale (FES) was used to evaluate fall efficacy, and the modified Barthel index (MBI) was used to evaluate activities of daily living. All evaluations were conducted once prior to intervention implementation and again six weeks after the final intervention. In the study results, the experimental group to which the diagonal exercise training was applied had statistically significant changes in FTSST, BBS, and FES compared to the control group. In conclusion, the rehabilitation program, including diagonal exercise training, increased the patient's balance and reduced the fear of falling.

A Comprehensive Review of the Effects of Extracorporeal Shock Wave Therapy on Stroke Patients: Balance, Pain, Spasticity.

Stroke remains a leading cause of disability worldwide, with survivors often experiencing impairments in balance, pain, spasticity, and control that limit their ability to perform daily living activities. Extracorporeal shock wave therapy (ESWT) has emerged as a potential treatment modality to improve these outcomes in stroke patients. This review aims to provide a comprehensive examination of the effects of ESWT on stroke patients, focusing on the theoretical background, balance, pain reduction, muscle spasticity and control, and upper and lower extremities. This study reviewed the use of ESWT in treating balance, pain, and spasticity in stroke patients, focusing on articles published in PubMed between January 2003 and January 2023. Systematic reviews related to stroke were used to provide an overview of stroke, and a total of 33 articles related to balance, pain, and spasticity were selected. ESWT has several shock wave generation methods and application methods, and it has been shown to have positive therapeutic effects on various aspects of rehabilitation for stroke patients, such as improving balance, reducing pain, decreasing muscle spasticity and increasing control, and enhancing functional activities of the upper and lower extremities. The efficacy of ESWT may vary depending on the patient's condition, application method, and treatment area. Therefore, it is important to apply ESWT according to the individual characteristics of each patient in clinical practice to maximize its potential benefits.

Experimental demonstration of necessary conditions for X-ray induced synthesis of cesium superoxide.

Absorption of sufficiently energetic X-ray photons by a molecular system results in a cascade of ultrafast electronic relaxation processes which leads to a distortion and dissociation of its molecular structure. Here, we demonstrate that only decomposition of powdered cesium oxalate monohydrate induced by monochromatic X-ray irradiation under high pressure leads to the formation of cesium superoxide. Whereas, for an unhydrated form of cesium oxalate subjected to the same extreme conditions, only degradation of the electron density distribution is observed. Moreover, the corresponding model of X-ray induced electronic relaxation cascades with an emphasis on water molecules' critical role is proposed. Our experimental results suggest that the presence of water molecules in initially solid-state systems (i.e. additional electronic relaxation channels) together with applied high pressure (reduced interatomic/intermolecular distance) could potentially be a universal criteria for chemical and structural synthesis of novel compounds via X-ray induced photochemistry.

Crystal and Electronic Structures of A2NaIO6 Periodate Double Perovskites (A = Sr, Ca, Ba): Candidate Wasteforms for I-129 Immobilization.

The synthesis, structure, and thermal stability of the periodate double perovskites A2NaIO6 (A= Ba, Sr, Ca) were investigated in the context of potential application for the immobilization of radioiodine. A combination of X-ray diffraction and neutron diffraction, Raman spectroscopy, and DFT simulations were applied to determine accurate crystal structures of these compounds and understand their relative stability. The compounds were found to exhibit rock-salt ordering of Na and I on the perovskite B-site; Ba2NaIO6 was found to adopt the Fm-3m aristotype structure, whereas Sr2NaIO6 and Ca2NaIO6 adopt the P21/n hettotype structure, characterized by cooperative octahedral tilting. DFT simulations determined the Fm-3m and P21/n structures of Ba2NaIO6 to be energetically degenerate at room temperature, whereas diffraction and spectroscopy data evidence only the presence of the Fm-3m phase at room temperature, which may imply an incipient phase transition for this compound. The periodate double perovskites were found to exhibit remarkable thermal stability, with Ba2NaIO6 only decomposing above 1050 °C in air, which is apparently the highest recorded decomposition temperature so far recorded for any iodine bearing compound. As such, these compounds offer some potential for application in the immobilization of iodine-129, from nuclear fuel reprocessing, with an iodine incorporation rate of 25-40 wt%. The synthesis of these compounds, elaborated here, is also compatible with both current conventional and future advanced processes for iodine recovery from the dissolver off-gas.

Molecular dynamics simulation of zirconium tungstate amorphization and the amorphous-crystalline interface.

Classical molecular dynamics (MD) simulations were performed to provide a conceptual understanding of the amorphous-crystalline interface for a candidate negative thermal expansion (NTE) material, ZrW2O8. Simulations of pressure-induced amorphization at 300 K indicate that an amorphous phase forms at pressures of 10 GPa and greater, and this phase persists when the pressure is subsequently decreased to 1 bar. However, the crystalline phase is recovered when the slightly distorted 5 GPa phase is relaxed to 1 bar. Simulations were also performed on a two-phase model consisting of the high-pressure amorphous phase in direct contact with the crystalline phase. Upon equilibration at 300 K and 1 bar, the crystalline phase remains unchanged beyond a thin layer of disrupted structure at the crystalline-amorphous interface. Differences in local atomic structure at the interface are quantified from the simulation trajectories.

Structure-thermodynamics relationship of schoepite from first-principles.

The relationship between the structure and thermodynamic properties of schoepite, an important uranyl phase with formula [(UO2)8O2(OH)12]·12H2O formed upon corrosion of UO2, has been investigated within the framework of density functional perturbation theory (DFPT). Experimental crystallographic lattice parameters are well reproduced in this study using standard DFT. Phonon calculations within the quasi-harmonic approximation predict standard molar entropy and isobaric heat capacity of S0 = 179.60 J mol-1 K-1 and C0P = 157.4 J mol-1 K-1 at 298.15 K, i.e., ∼6% and ∼4% larger than existing DFPT-D2 calculations. The computed variation of the standard molar isobaric heat capacity with water content from schoepite (UO3·xH2O, x = 2.25) to dehydrated schoepite (x = 1) is predicted to be essentially linear along isotherms ranging from 100 to 500 K. These findings have important implications for the dehydration of layered uranyl corrosion phases and hygroscopic materials.

A comprehensive assessment of the low-temperature thermal properties and thermodynamic functions of CeO2.

Reported is an experimental and computational investigation of the low temperature heat capacity, thermodynamic functions, and thermal conductivity of stoichiometric, polycrystalline CeO2. The experimentally measured heat capacity at T < 15 K provides an important correction to the historically accepted experimental values, and the low temperature thermal conductivity serves as the most comprehensive data set at T < 400 K available. Below 10 K, the heat capacity is observed to obey the Debye T3 law, with a Debye temperature of ΘD = 455 K. The entropy, enthalpy, and Gibbs free energy functions are obtained from the experimental heat capacity and compared with predictions from Hubbard-corrected density functional perturbation theory calculations using the Perdew, Burke, and Ernzerhof parameterization revised for solids. The thermal conductivity is determined using the Maldonado continuous measurement technique, along with laser flash analysis, and analyzed according to the Klemens-Callaway model.

Pressure-Tuneable Visible-Range Band Gap in the Ionic Spinel Tin Nitride.

The application of pressure allows systematic tuning of the charge density of a material cleanly, that is, without changes to the chemical composition via dopants, and exploratory high-pressure experiments can inform the design of bulk syntheses of materials that benefit from their properties under compression. The electronic and structural response of semiconducting tin nitride Sn3 N4 under compression is now reported. A continuous opening of the optical band gap was observed from 1.3 eV to 3.0 eV over a range of 100 GPa, a 540 nm blue-shift spanning the entire visible spectrum. The pressure-mediated band gap opening is general to this material across numerous high-density polymorphs, implicating the predominant ionic bonding in the material as the cause. The rate of decompression to ambient conditions permits access to recoverable metastable states with varying band gaps energies, opening the possibility of pressure-tuneable electronic properties for future applications.

High-pressure-assisted X-ray-induced damage as a new route for chemical and structural synthesis.

X-ray induced damage has been known for decades and has largely been viewed as a tremendous nuisance. We, on the other hand, harness the highly ionizing and penetrating properties of hard X-rays to initiate novel decomposition and synthetic chemistry. Here, we show that powdered cesium oxalate monohydrate pressurized to ≤0.5 GPa and irradiated with X-rays of energies near the cesium K-edge undergoes molecular and structural transformations with one of the final products exhibiting a new type of bcc crystal structure that has previously not been observed. Additionally, based on cascades of ultrafast electronic relaxation steps triggered by the absorption of one X-ray photon, we propose a model explaining the X-ray induced damage of multitype bounded matter. As X-rays are ubiquitous, these results show promise in the preparation of novel compounds and novel structures that are inaccessible via conventional methods. They may offer insight into the formation of complex organic compounds in outer space.

Zirconium tetrachloride revisited.

Zirconium tetrachloride, ZrCl4, is a strategic material with wide-ranging applications. Until now, only one crystallographic study on ZrCl4 has been reported [Krebs (1970). Z. Anorg. Allg. Chem. 378, 263-272] and that was more than 40 years ago. The compound used for the previous determination was prepared from ZrO2 and Cl2-CCl4, and single-crystal X-ray diffraction (SCXRD) studies on ZrCl4 obtained from Zr metal have not yet been reported. In this context, we prepared ZrCl4 from the reaction of Zr metal and Cl2 gas in a sealed tube and investigated its structure at 100, 150, 200, 250, and 300 K. At 300 K, the SCXRD analysis indicates that ZrCl4 crystallizes in the orthorhombic space group Pca21 [a = 6.262 (9), b = 7.402 (11), c = 12.039 (17) Å, and V = 558.0 (14) Å3] and consists of infinite zigzag chains of edge-sharing ZrCl6 octahedra. This chain motif is similar to that observed previously in ZrCl4, but the structural parameters and space group differ. In the temperature range 100-300 K, no phase transformation was identified, while elongation of intra-chain Zr...Zr [3.950 (1) Šat 100 K and 3.968 (5) Šat 300 K] and inter-chain Cl...Cl [3.630 (3) Šat 100 K and 3.687 (9) Šat 300 K] distances occurred.

Phosphorus Dimerization in Gallium Phosphide at High Pressure.

Using combined experimental and computational approaches, we show that at 43 GPa and 1300 K gallium phosphide adopts the super- Cmcm structure, here indicated with its Pearson notation oS24. First-principles enthalpy calculations demonstrate that this structure is more thermodynamically stable above ∼20 GPa than previously proposed polymorphs. In contrast to other polymorphs, the oS24 phase shows a strong bonding differentiation and distorted fivefold coordination geometries of both P atoms. The shortest bond of the phase is a single covalent P-P bond measuring 2.171(11) Šat synthesis pressure. Phosphorus dimerization in GaP sheds light on the nature of the super- Cmcm phase and provides critical new insights into the high-pressure polymorphism of octet semiconductors. Bond directionality and anisotropy explain the relatively low symmetry of this high-pressure phase.

First-Principles Structural, Mechanical, and Thermodynamic Calculations of the Negative Thermal Expansion Compound Zr2(WO4)(PO4)2.

The negative thermal expansion (NTE) material Zr2(WO4)(PO4)2 has been investigated for the first time within the framework of the density functional perturbation theory (DFPT). The structural, mechanical, and thermodynamic properties of this material have been predicted using the Perdew, Burke and Ernzerhof for solid (PBEsol) exchange-correlation functional, which showed superior accuracy over standard functionals in previous computational studies of the NTE material α-ZrW2O8. The bulk modulus calculated for Zr2(WO4)(PO4)2 using the Vinet equation of state at room temperature is K 0 = 63.6 GPa, which is in close agreement with the experimental estimate of 61.3(8) at T = 296 K. The computed mean linear coefficient of thermal expansion is -3.1 × 10-6 K-1 in the temperature range ∼0-70 K, in line with the X-ray diffraction measurements. The mean Grüneisen parameter controlling the thermal expansion of Zr2(WO4)(PO4)2 is negative below 205 K, with a minimum of -2.1 at 10 K. The calculated standard molar heat capacity and entropy are C P 0 = 287.6 and S 0 = 321.9 J·mol-1·K-1, respectively. The results reported in this study demonstrate the accuracy of DFPT/PBEsol for assessing or predicting the relationship between structural and thermomechanical properties of NTE materials.

Model representations of kerogen structures: An insight from density functional theory calculations and spectroscopic measurements.

Molecular structures of kerogen control hydrocarbon production in unconventional reservoirs. Significant progress has been made in developing model representations of various kerogen structures. These models have been widely used for the prediction of gas adsorption and migration in shale matrix. However, using density functional perturbation theory (DFPT) calculations and vibrational spectroscopic measurements, we here show that a large gap may still remain between the existing model representations and actual kerogen structures, therefore calling for new model development. Using DFPT, we calculated Fourier transform infrared (FTIR) spectra for six most widely used kerogen structure models. The computed spectra were then systematically compared to the FTIR absorption spectra collected for kerogen samples isolated from Mancos, Woodford and Marcellus formations representing a wide range of kerogen origin and maturation conditions. Limited agreement between the model predictions and the measurements highlights that the existing kerogen models may still miss some key features in structural representation. A combination of DFPT calculations with spectroscopic measurements may provide a useful diagnostic tool for assessing the adequacy of a proposed structural model as well as for future model development. This approach may eventually help develop comprehensive infrared (IR)-fingerprints for tracing kerogen evolution.

Assessing Hubbard-corrected AM05+U and PBEsol+U density functionals for strongly correlated oxides CeO2 and Ce2O3.

The structure-property relationships of bulk CeO2 and Ce2O3 have been investigated using AM05 and PBEsol exchange-correlation functionals within the frameworks of Hubbard-corrected density functional theory (DFT+U) and density functional perturbation theory (DFPT+U). Compared with conventional PBE+U, RPBE+U, PW91+U and LDA+U functionals, AM05+U and PBEsol+U describe experimental crystalline parameters and properties of CeO2 and Ce2O3 with superior accuracy, especially when +U is chosen close to its value derived by the linear-response approach. The present findings call for a reexamination of some of the problematic oxide materials featuring strong f- and d-electron correlation using AM05+U and PBEsol+U.

Technetium incorporation in scheelite: insights from first-principles.

Atomistic investigations of crystalline scheelite, CaWO4, and 99Tc-bearing scheelite, CaWO4:Tc, have been carried out using density functional theory. The lattice constants, bulk modulus, and volume compression data of CaWO4 have been calculated and compared with experimental data, with a focus on predictive understanding of 99Tc incorporation in CaWO4. Defect formation energies have been computed for several possible interstitial (I) and substitutional (S) sites of 99Tc in CaWO4. Both I(Oh) and S(W) sites were found to be energetically favourable for Tc doping. X-ray diffraction (XRD) spectra for each 99Tc defect type have been simulated to help interpret the complex experimental XRD patterns. This work on CaWO4:Tc provides insights into materials generated during nuclear weapons testing and useful spectral signatures for nuclear forensics.

Mechanical properties of zirconium alloys and zirconium hydrides predicted from density functional perturbation theory.

The elastic properties and mechanical stability of zirconium alloys and zirconium hydrides have been investigated within the framework of density functional perturbation theory. Results show that the lowest-energy cubic Pn3[combining macron]m polymorph of δ-ZrH1.5 does not satisfy all the Born requirements for mechanical stability, unlike its nearly degenerate tetragonal P42/mcm polymorph. Elastic moduli predicted with the Voigt-Reuss-Hill approximations suggest that mechanical stability of α-Zr, Zr-alloy and Zr-hydride polycrystalline aggregates is limited by the shear modulus. According to both Pugh's and Poisson's ratios, α-Zr, Zr-alloy and Zr-hydride polycrystalline aggregates can be considered ductile. The Debye temperatures predicted for γ-ZrH, δ-ZrH1.5 and ε-ZrH2 are θD = 299.7, 415.6 and 356.9 K, respectively, while θD = 273.6, 284.2, 264.1 and 257.1 K for the α-Zr, Zry-4, ZIRLO and M5 matrices, i.e. suggesting that Zry-4 possesses the highest micro-hardness among Zr matrices.

Time-Resolved Infrared Reflectance Studies of the Dehydration-Induced Transformation of Uranyl Nitrate Hexahydrate to the Trihydrate Form.

Uranyl nitrate is a key species in the nuclear fuel cycle. However, this species is known to exist in different states of hydration, including the hexahydrate ([UO2(NO3)2(H2O)6] often called UNH), the trihydrate [UO2(NO3)2(H2O)3 or UNT], and in very dry environments the dihydrate form [UO2(NO3)2(H2O)2]. Their relative stabilities depend on both water vapor pressure and temperature. In the 1950s and 1960s, the different phases were studied by infrared transmission spectroscopy but were limited both by instrumental resolution and by the ability to prepare the samples for transmission. We have revisited this problem using time-resolved reflectance spectroscopy, which requires no sample preparation and allows dynamic analysis while the sample is exposed to a flow of N2 gas. Samples of known hydration state were prepared and confirmed via X-ray diffraction patterns of known species. In reflectance mode the hexahydrate UO2(NO3)2(H2O)6 has a distinct uranyl asymmetric stretch band at 949.0 cm(-1) that shifts to shorter wavelengths and broadens as the sample desiccates and recrystallizes to the trihydrate, first as a shoulder growing in on the blue edge but ultimately results in a doublet band with reflectance peaks at 966 and 957 cm(-1). The data are consistent with transformation from UNH to UNT as UNT has two inequivalent UO2(2+) sites. The dehydration of UO2(NO3)2(H2O)6 to UO2(NO3)2(H2O)3 is both a structural and morphological change that has the lustrous lime green UO2(NO3)2(H2O)6 crystals changing to the matte greenish yellow of the trihydrate solid. The phase transformation and crystal structures were confirmed by density functional theory calculations and optical microscopy methods, both of which showed a transformation with two distinct sites for the uranyl cation in the trihydrate, with only one in the hexahydrate.