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Apraxic deficits predict general cognitive impairment in patients with biomarker-verified Alzheimer’s pathology
No full textApraxia represents a core feature of Alzheimer's disease (AD), a neurodegenerative disorder characterised by the accumulation of β-amyloid plaques and tau deposition. However, systematic descriptions of apraxic deficits in AD patients remain scarce. Here, we comprehensively investigate apraxia profiles and their link with cognitive impairment in patients with biomarker-verified Alzheimer's pathology. We characterised the frequency and patterns of apraxic deficits in patients with biomarker-verified Alzheimer's pathology using a battery of standardised apraxia tests. Demographic variables and apraxia scores were related to patients' general cognitive impairment using hierarchical regression analysis. Apraxic deficits were found in 67% of patients with biomarker-verified Alzheimer's pathology (n = 63). Patients with Alzheimer's pathology were more impaired in imitating finger gestures (than hand gestures: 89.2% vs. 80.0%, p < 0.001) and imitating complex hand movements (than single hand movements: 97.4% vs. 78.5%, p < 0.001), even when controlling for general cognitive impairment. Apraxia assessments explained about 60% of the variance in dementia severity, with performance in the KAS subtest of pantomiming object use (beta coefficient: 0.47, p = 0.001) and the DATE subtest for limb apraxia (beta coefficient: 0.37, p = 0.005) constituting significant predictors of general cognitive impairment. These findings emphasise the relevance of apraxia in patients with biomarker-verified Alzheimer's pathology, revealing that praxis deficits predict general cognitive impairment in AD. Further research is warranted into the role of apraxia as a potential early diagnostic criterion in AD
Photochemical aging of aviation emissions: transformation of chemical and physical properties of exhaust emissions from a laboratory-scale jet engine combustion chamber
No full textStratospheric Hydration and Ice Microphysics of a Convective Overshoot Observed during the TPEx Campaign over Sweden
No full textCan atmospheric chemistry deposition schemes reliably simulate stomatal ozone flux across global land covers and climates?
No full textSegregation-guided alloy design via tailored solidification behavior
No full textThis study presents an alloy design perspective guided by elemental segregation during solidification to determine the site-specific chemistry and related local thermodynamic properties of dendritic microstructures. This was accomplished via manipulation of the microsegregation behavior by means of nominal alloy composition and thermal conditions of the solidification processes, including modified cooling rates spanning over six orders of magnitudes using ingot casting, directed energy deposition (DED-LB/M) additive manufacturing (AM) and laser powder bed fusion (PBF-LB/M) AM processes. Our approach was demonstrated by computationally designing a novel AlxCo25Fe(50-x)Ni25 multi-principal element alloy (MPEA) as a model system, employing a combination of CALPHAD, Scheil, and multiphase-field simulations, and by experimentally validating the resulting microstructure evolution. The lower Al content (x = 10.5) was designated to generate a supersaturated single-phase fcc matrix suitable for heat-treatments to trigger local phase transformations. The higher Al content (x = 14.5) was selected to define the size and morphology of dual-phase microstructures by controlling phase nucleation and growth through segregation during solidification. Our results showcased how selective enrichment of the desired elements in interdendritic regions can be employed to induce local phase transformations during solidification or post heat-treatments, while their size can be flexibly controlled by the degree of undercooling during solidification. The suggested segregation-guided design approach can be transferred to other alloy systems, enabling effective tuning of local functional, structural, kinetic, and, as shown in this study, thermodynamic properties of dendritic microstructures by predetermining the nature of the alloy matrix through tailored solidification behavior
From the plant layouts to optimized LP and 3D PWR-KWU containment models for combustion risk assessment with GOTHIC 8.3(QA)
No full textBiofertilizer based on Aspergillus niger and Acidithiobacillus thiooxidans to enhance phosphorus and sulfur availability in soil
No full textIntensive fertilization has become necessary to supply nutrients for plant growth under current agricultural practices aimed at meeting global food demands. Macronutrients such as phosphorus and sulfur are essential for the plant growth cycle and, consequently, for improving productivity. Struvite (MgNH₄PO₄·6H₂O) is a valuable phosphorus source that can even be recycled from wastewater; however, it typically exhibits low solubility. Similarly, elemental sulfur (S⁰) offers a high-concentration source of sulfate, but its availability is constrained by the soil’s capacity to support microbial S⁰ oxidation [1]. In this study, we propose the integration of these nutrients into a composite material based on a biodegradable starch matrix. This matrix enables the encapsulation of acidifying agents, including Aspergillus niger, associated with the carbon cycle, and Acidithiobacillus thiooxidans, associated with the sulfur cycle—both of which are native soil microorganisms. This strategy effectively enhanced nutrient solubility, with the starch/S⁰/phosphorus biofertilizer composite showing promising results in soil incubation experiments. These findings contribute to the advancement of environmentally friendly fertilizers and support the development of more sustainable agricultural practices. Additionally, this approach may open new avenues for the use of low-solubility nutrient sources in future fertilizer formulations
Impurities in Precursor and Their Effect on the Synthesis of W‐Substituted : Enabling Thiophosphate Electrolytes for Sodium Solid‐State Batteries
No full textSodium solid-state batteries are intensively researched, expecting a resource-uncritical alternative to their lithium counterparts. As in the case of lithium, sulfide-type electrolytes show promising ionic conductivities , and -type solid electrolytes are intensively investigated. Aliovalent substitution of by is shown to achieve sodium ion conductivity beyond , rendering them good candidates for cathode composites. Yet, incorporating into the crystal lattice of is deemed challenging, and electrolytes suffer from residue after synthesis. In this work, impurities in the precursor are identified and the detrimental influence of groups in on the synthesis of and is demonstrated. The behavior of oxygen as impurity during synthesis is pinpointed, and complete incorporation of tungsten up to x ≈ 0.25 in by purified , realizing up to at room temperature
Structural and Magnetic Characterization of RCrO3 (R = Ho, Gd)Complex Perovskites
No full textRare-earth orthochromites (RCrO₃) have attracted widespread attention in recent years due to theirrich physical properties and potential applications in spintronics, thermomagnetic switches, photocatalysts,and low-temperature magnetic refrigeration [1-3]. RCrO₃ exhibits canted antiferromagneticbehavior with the canting caused by the Dzyaloshinskii–Moriya interactions and the interactionbetween Cr³⁺ and rare-earth magnetic sublattices, the latter of which also leads to negativemagnetization under certain thermal and magnetic conditions [1]. These interactions and magneticfrustration lead to deviations from classical Curie–Weiss behavior at low temperatures. Among allthe rare-earth orthochromites, we chose HoCrO3 (HCO) for our study, because in this compound,the Ho3+ ion owns a large magnetic moment ~ 10.6 μB. From the Curie-Weiss fit of magnetic susceptibilitydata, we observed a large negative value of the Weiss temperature, which showed theantiferromagnetic nature and magnetic frustration in the compound. We also found very large valuesof the magnetocaloric parameters [3]. This study opens an avenue for further investigation ofother rare-earth metals to explore magnetic frustrations. GdCrO3 is another promising candidatefor a variety of physical applications, especially its magnetic and giant magnetocaloric properties[4].Therefore, in our current study, we aim to grow high-quality single crystals of GdCrO3 for detailedneutron scattering experiments to elucidate frustrated magnetic states and correlated spin dynamics.The prepared polycrystalline precursors were characterized using powder X-ray diffraction followedby Rietveld refinement to determine their structural and microstructural properties. Furthermore,magnetic studies revealed a negative magnetization at low temperatures, along with spin reorientationbehavior. By fitting the dc magnetization data with the modified Curie–Weiss law, including theDzyaloshinskii–Moriya antisymmetric exchange interaction (D) and the symmetric exchange constant(J), these parameters were obtained. This comprehensive characterization shows the precursorsto be highly suitable for crystal growth, which is currently being pursued with laser floating-zonefurnace. Available first results on crystals would be shown as well.[1] A. A. Qahtan, et. al., Physica Scripta, 99, 072001 (2024).[2] M. Rani, et. al., Ceramics International, 48, 19925-19936 (2022).[3] K. Kanwar, et. al., Ceramics International, 47, 7386-7397 (2021).[4] S. Mahana, et. al., Journal of Physics D: Applied Physics, 51, 305002 (2018)