Search Results (318)

Background: Hand dexterity is affected by normal aging and neuroinflammatory processes in the brain. Understanding the relationship between hand dexterity and brain structure in neurotypical older adults may be informative about prodromal pathological processes, thus providing an opportunity for earlier diagnosis and intervention to improve functional outcomes. Methods: this study investigates the associations between hand dexterity and brain measures in neurotypical older adults (≥65 years) using the Nine-Hole Peg Test (9HPT) and magnetic resonance imaging (MRI). Results: Elastic net regularized regression revealed that reduced hand dexterity in dominant and non-dominant hands was associated with an enlarged volume of the left choroid plexus, the region implicated in neuroinflammatory and altered myelination processes, and reduced myelin content in the left frontal operculum, the region implicated in motor imagery, action production, and higher-order motor functions. Distinct neural mechanisms underlying hand dexterity in dominant and non-dominant hands included the differences in caudate and thalamic volumes as well as altered cortical myelin patterns in frontal, temporal, parietal, and occipital regions supporting sensorimotor and visual processing and integration, attentional control, and eye movements. Although elastic net identified more predictive features for the dominant vs. non-dominant hand, the feature stability was higher for the latter, thus indicating higher generalizability for the non-dominant hand model. Conclusions: Our findings suggest that the 9HPT for hand dexterity might be a cost-effective screening tool for early detection of neuroinflammatory and neurodegenerative processes. Longitudinal studies are needed to validate our findings in a larger sample and explore the potential of hand dexterity as an early clinical marker. Full article

The development of high-strength aluminum alloys with improved ductility is a crucial challenge for modern materials science, as high strength and ductility tend to be mutually exclusive properties. In this work, the composite material was fabricated using wire arc additives manufactured from AA1050 (commercially pure aluminum) and AA5056 (an Al–Mg system alloy) aluminum alloys. It was demonstrated that the addition of a lower-strength material into a high-strength matrix enhances the potential for deformation localization and results in an increased plasticity of the composite material. A further strengthening of the composite material was achieved through its deformation by a high-pressure torsion (HPT) technique. The mechanical properties of the material were thoroughly investigated before and after the HPT treatment. Static strength and plasticity were analyzed as a function of the deformation degree. Microstructural analysis was performed using scanning electron microscopy and X-ray diffraction. The optimal deformation route, providing the best combination of mechanical properties, was experimentally identified, along with key microstructural parameters of the formed composite with a bimodal grain structure. A deformation level corresponding to 36% of shear stress provides a yield stress of up to 570 MPa, an ultimate tensile strength of up to 664 MPa, and a relative elongation to failure of up to 7%. As a result of the deformation treatment, characteristic substructures with dimensions of ~250 nm and >1000 nm are formed, with a volume ratio of approximately 80/20. Full article

Objective: This study aimed to explore longitudinal relationships between neurophysiological biomarkers and upper limb motor function recovery in stroke patients, focusing on electroencephalography (EEG) and transcranial magnetic stimulation (TMS) metrics. Methods: This longitudinal cohort study analyzed neurophysiological, clinical, and demographic data from 102 stroke patients enrolled in the DEFINE cohort. We investigated the associations between baseline and post-intervention changes in the EEG theta/alpha ratio (TAR) and TMS metrics with upper limb motor functionality, assessed using the outcomes of five tests: the Fugl-Meyer Assessment (FMA), Handgrip Strength Test (HST), Pinch Strength Test (PST), Finger Tapping Test (FTT), and Nine-Hole Peg Test (9HPT). Results: Our multivariate models identified that a higher baseline TAR in the lesioned hemisphere was consistently associated with poorer motor outcomes across all five assessments. Conversely, a higher improvement in the TAR was positively associated with improvements in FMA and 9HPT. Additionally, an increased TMS motor-evoked potential (MEP) amplitude in the non-lesioned hemisphere correlated with greater FMA-diff, while a lower TMS Short Intracortical Inhibition (SICI) in the non-lesioned hemisphere was linked to better PST improvements. These findings suggest the potential of the TAR and TMS metrics as biomarkers for predicting motor recovery in stroke patients. Conclusion: Our findings highlight the significance of the TAR in the lesioned hemisphere as a predictor of motor function recovery post-stroke and also a potential signature for compensatory oscillations. The observed relationships between the TAR and motor improvements, as well as the associations with TMS metrics, underscore the potential of these neurophysiological measures in guiding personalized rehabilitation strategies for stroke patients. Full article

This in vitro study evaluated the effects of brushing with activated charcoal powder or toothpaste on enamel surface properties, including color change (ΔE), Knoop microhardness (HK), roughness (Ra), and the characteristics of the resulting brushing slurry [pH, fluoride (F⁻), and calcium (Ca²⁺) concentration]. A total of 48 enamel samples were stained and divided into 4 groups (n = 12): activated charcoal toothpaste (AC-T), activated charcoal powder (AC-P), hydrogen peroxide-based whitening toothpaste (HP-T), and conventional toothpaste (C-T, positive control). The samples were subjected to a brushing cycling model, and ΔE, HK, Ra and enamel morphology were analyzed at baseline (T0) and after brushing cycle (T1). Additionally, the pH, soluble F⁻, and Ca²⁺ concentrations of the slurry were analyzed. Data were analyzed using ANOVA/Tukey and paired t-tests (α = 0.05). After brushing, AC-T and AC-P (p < 0.05) showed a decrease in HK, an increase in Ra, and no ΔE variation was observed between groups (p = 0.163). All products had alkaline slurries (>7), and AC-P had no detectable F⁻ (p = 0.00) with significantly higher calcium loss (p = 0.015). Fewer enamel topographical changes were observed in C-T. In conclusion, brushing with CA toothpowder and toothpaste does not promote color change, but toothpowder increases surface Ra, decreases enamel HK, lacks F⁻, and causes greater Ca²⁺ loss. Full article

The aim of this study was to revisit the complex relationship between inflammation, oxidative stress and lipid metabolism in dogs with hypercortisolism (HC). Fourteen dogs newly diagnosed with HC and an equal number of healthy counterparts of similar age and markers of oxidative stress (AOPP, TBARS, TAC, GSH, PON-1, and UA) and inflammation (NLR, PLR, SII, HPT, CHE, CP, and Hcy) were included in the study. To determine the lipid profiles, cholesterol, and triglyceride levels were measured, and the electrophoretic separation of lipoproteins was performed. The results revealed that dogs with HC had higher levels of AOPP and TBARS, but only greater levels of GSH among antioxidants. Uric acid levels were higher in HC dogs, suggesting a pro-oxidative role. Elevated NLR, PLR, SII, and HPT levels were detected, but they did not seem to be associated with inflammation. Notable changes were detected in the HDL fraction, alongside hypercholesterolaemia and hypertriglyceridaemia. Correlation analysis revealed links between lipid markers and both oxidative stress and inflammatory indices. In conclusion, the data acquired may prove useful in further understanding of the intricate pathophysiology of Cushing’s syndrome. Full article

This study explores the impact of short-term annealing on the thermal stability and mechanical properties of oxygen-free copper subjected to high-pressure torsion (HPT). Copper samples were deformed through HPT with varying numbers of turns at room temperature and subsequently subjected to short-term annealing at temperatures of 398 K and 423 K. Microstructural analysis revealed that annealing led to grain growth and a reduction in dislocation density, with samples processed with fewer HPT turns exhibiting more significant grain coarsening. The microhardness measurements indicated a reduction in hardness after annealing, particularly at the edges of the discs, suggesting recrystallization. Samples processed with 10 HPT turns demonstrated higher thermal stability and less grain growth compared to 1/2-turn samples. The findings suggest that post-HPT short-term annealing can be used to tailor the balance between strength and ductility in oxygen-free copper, enhancing its suitability for industrial applications. Full article

Oil palm (Elaeis guineensis Jacq.) is the most efficient oil-producing crop globally, yet progress in its research has been hampered by the lack of effective genetic transformation systems. The EPSPS gene, encoding 5-enolpyruvylshikimate-3-phosphate synthase, has been used as a transgenic selection marker in various crops, including rice and soybean. This study evaluated the EPSPS/glyphosate selection system for oil palm transformation. We constructed a binary expression vector, pCGlyDESCLI-C, containing the TIPS-EiEPSPS selection marker from goosegrass and the mScarlet-I red fluorescent reporter gene. This vector was introduced into oil palm embryonic callus (EC) via Agrobacterium-mediated transformation. After optimizing the transformation steps, positive calli were obtained, and integration of the foreign gene into the oil palm genome was confirmed through molecular analysis. Notably, the selection efficiency of the EPSPS/glyphosate selection system exceeded that of the traditional hpt/hygromycin selection system, demonstrating its advantages. Our findings support the effectiveness of the TIPS-EiEPSPS/glyphosate selection system for oil palm genetic transformation, marking its first application in this species and offering a valuable tool for advancing research on this economically significant crop. Full article

Commercially pure Cu features excellent electric conductivity but low mechanical properties. In order to improve the mechanical properties of Cu, strengthening elements can be added to prepare alloys or composites featuring enhanced performances. This study focuses on the detailed characterization of the microstructure of a Cu composite strengthened with Al₂O₃ particles during high shear strain processing. The Cu-Al₂O₃ mixture was prepared by powder metallurgy and directly consolidated by the intensive plastic deformation method of hot rotary swaging. Samples cut from the consolidated piece were further processed by the severe plastic deformation method of high pressure torsion (HPT). The primary aim was to investigate the effects of varying degrees of the imposed shear strain, i.e., the number of HPT revolutions, microstructure development (grain size and morphology, texture, grain misorientations, etc.) of the consolidated composite; the microstructure observations were supplemented with measurements of Vickers microhardness. The results showed that the added oxide particles effectively hindered the movement of dislocations and aggravated grain fragmentation, which also led to the relatively high presence of grain misorientations pointing to the occurrence of residual stress within the microstructure. The high shear strain imposed into (the peripheral region of) the sample subjected to four HPT revolutions imparted equiaxed ultra-fine grains and an average Vickers microhardness of more than 130 HV0.1. Full article

Background/Objectives: Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system characterized by progressive impairment of neuronal transmission due to focal demyelination. The most common form is RRMS (relapsing-remitting multiple sclerosis), which, under the influence of certain factors, can progress to SPMS (secondary progressive multiple sclerosis). Our study aimed to validate the criteria proposed by a working group of the Romanian Society of Neurology versus the criteria proposed by a group of experts from Spain, Karolinska, and Croatia concerning the progression from RRMS to SPMS. Methods: This was done by gathering epidemiological data (age, gender) and by applying clinical tests such as the 9HPT (9-hole peg test), 25FWT (25-foot walk test), and EDSS (expanded disability status scale) tests and the SDMT test (symbol digit modalities test). The present research is a cohort study that included a number of 120 patients diagnosed with MS according to the McDonald Diagnostic Criteria 2017. The study was carried out between January 2023 and April 2024, including patients hospitalized in the Neurology Clinic of the Clinical Rehabilitation Hospital from Iasi, Romania. The data were collected at baseline (T0) and at a 12-month interval (T1). Results: The statistical analysis was conducted using Kaiser–Meyer–Olkin analysis, which indicated a value of 0.683, thus validating the clinical tests used. The correlation matrix and the linear regression for all the tests showed highly significant statistical results. Furthermore, the ROC curve analysis of the criteria suggested by the working group of the Romanian Society of Neurology demonstrated that the EDSS, 9HPT, and 25FWT are highly sensitive in diagnosing SPMS, an opinion that is shared with the Spanish experts, but not with the Karolinska expert panel. Using the criteria given by the Croatian expert group in the ROC curve analysis showed that only the EDSS was strongly significant for the progression to the SPMS phase. Conclusions: In conclusion, all clinical methods used demonstrated that they are valid and can contribute to identifying patients with an increased risk of progression. The model proposed by the Romanian Society of Neurology working group is similar to other countries’ expert opinions and can be used to detect the risk of disease progression and establish a more tailored therapeutic management of SPMS. Full article

Machine learning tools represent a key methodology for the shape optimization of complex geometries in the turbomachinery field. One of the current challenges is to redesign High-Pressure Turbine (HPT) stages to couple them with innovative combustion technologies. In fact, recent developments in the gas turbine field have led to the introduction of pioneering solutions such as Rotating Detonation Combustors (RDCs) aimed at improving the overall efficiency of the thermodynamic cycle at low overall pressure ratios. In this study, a HPT vane equipped with diffusive endwalls is optimized to allow for ingesting a high-subsonic flow ($Ma=0.6$) delivered by a RDC. The main purpose of this paper is to investigate the prediction ability of machine learning tools in case of multiple input parameters and different objective functions. Moreover, the model predictions are used to identify the optimal solutions in terms of vane efficiency and operating conditions. A new solution that combines optimal vane efficiency with target values for both the exit flow angle and the inlet Mach number is also presented. The impact of the newly designed geometrical features on the development of secondary flows is analyzed through numerical simulations. The optimized geometry achieved strong mitigation of the intensity of the secondary flows induced by the main flow separation from the diffusive endwalls. As a consequence, the overall vane aerodynamic efficiency increased with respect to the baseline design. Full article

Understanding carboxylate transport through lipid membranes under physiological conditions is critical in biomedicine and biotechnology, as it allows for the emulation of biological membrane functions and can enhance the absorption of hydrophobic carboxylate-based drugs. However, the structural diversity of carboxylates has made it challenging to study their transport, and the limited available examples do not provide a comprehensive understanding of the role of the organic moiety in this process. Here, we present an in-depth analysis of the diffusion and transport of various aliphatic and aromatic carboxylates into liposomes. We assessed the influence of their size, number of carboxylate groups, and presence of hydroxyl groups. Our findings from fluorescence assays, using lucigenin and HPTS as probes, revealed that most carboxylates can spontaneously diffuse into liposomes in their protonated state, facilitated by the efflux of HNO₃ when using NaNO₃ solutions at pH 7. The Cl-ISE assay showed chloride/carboxylate exchange by a synthetic anion transporter. Clear trends were observed when the organic moiety was systematically varied, with a particular enhancement of anion transport by the presence of hydroxyl groups in the aromatic carboxylates. Our findings provide insights into the processes by which carboxylates can enter liposomes, which can contribute to understanding the transport of other biologically relevant organic anions. Full article

To meet the requirements of future aircraft for power systems, the turbine inlet temperatures of aero engines are gradually increasing. Ceramic matrix composite (CMC), with its higher thermal limit, has become the preferred material for the turbine blades of variable cycle engines (VCEs). However, the impact of CMC turbine blades on the performance of a VCE is still unknown. In this research project, the comprehensive cooling-efficiency characteristics of CMC are determined through a fluid–solid coupling calculation; a cooling calculation model for turbine blades is established, and cooling airflow solution and control technology (CSCT) for an air system is developed. Additionally, a VCE simulation model is established to analyze the influence of CMC turbine blades on the cooling airflow of the air system and the overall performance of the engine. The results show that, for the design condition, the CMC turbine blade can reduce the cooling airflow of the air system by approximately 10%, and the net thrust is increased by 6.07–7.98%. For the off-design conditions, with the CSCT, the specific fuel consumption can be reduced by 3.06–5.73% while ensuring that the engine net thrust remains unchanged. A comprehensive analysis of the performance for both the design point and off-design points indicates that the use of CMC for high-pressure turbine (HPT) guide vanes and rotor blades yields significant performance benefits, while the performance improvement from the use of CMC for low-pressure turbine (LPT) rotor blades is minimal. Full article

Reducing the saturation magnetostriction is an effective way to improve the performance of soft magnetic materials and reduce core losses in present and future applications. The magnetostrictive properties of binary Fe-based alloys are investigated for a broad variety of alloying elements. Although several studies on the influence of Cu-alloying on the magnetic properties of Fe are reported, few studies have focused on the effect on its magnetostrictive behavior. High pressure torsion deformation is a promising fabrication route to produce metastable, single-phase Fe-Cu alloys. In this study, the influence of Cu-content and the chosen deformation parameters on the microstructural and phase evolution in the Fe-Cu system is investigated by scanning electron microscopy and synchrotron X-ray diffraction. Magnetic properties and magnetostrictive behavior are measured as well. While a reduction in the saturation magnetostriction λ_s is present for all Cu-contents, two trends are noticeable. λ_s decreases linearly with decreasing Fe-content in Fe-Cu nanocomposites, which is accompanied by an increasing coercivity. In contrast, both the saturation magnetostriction as well as the coercivity strongly decrease in metastable, single-phase Fe-Cu alloys after HPT-deformation. Full article

Radiofrequency electromagnetic fields (RF-EMFs) can penetrate tissues and potentially influence endocrine and brain development. Despite increased mobile phone use among children and adolescents, the long-term effects of RF-EMF exposure on brain and endocrine development remain unclear. This study investigated the effects of long-term evolution band (LTE) EMF exposure on thyroid hormone levels, crucial for metabolism, growth, and development. Four-week-old male mice (C57BL/6) were exposed to LTE EMF (whole-body average specific absorption rate [SAR] 4 W/kg) or a positive control (lead; Pb, 300 ppm in drinking water) for 4 weeks. Subsequently, the mice underwent behavioral tests including open field, marble burying, and nest building. Blood pituitary and thyroid hormone levels, and thyroid hormone-regulating genes within the hypothalamus–pituitary–thyroid (HPT) axis were analyzed. LTE exposure increased T3 levels, while Pb exposure elevated T3 and T4 and decreased ACTH levels. The LTE EMF group showed no gene expression alterations in the thyroid and pituitary glands, but hypothalamic Dio2 and Dio3 expressions were significantly reduced compared to that in the sham-exposed group. Pb exposure altered the hypothalamic mRNA levels of Oatp1c1 and Trh, pituitary mRNA of Trhr, and Tpo and Tg expression in the thyroid. In conclusion, LTE EMF exposure altered hypothalamic Dio2 and Dio3 expression, potentially impacting the HPT axis function. Further research is needed to explore RF-EMF’s impacts on the endocrine system. Full article

In this prospective blinded study, canine C-reactive protein (c-CRP), haptoglobin (HPT), and 25-hydroxyvitamin-D (25(OH)D) were investigated for their diagnostic value in 55 dogs with nasal cavity disease (ND). After comprehensive diagnostics including a culture-dependent microbiological examination (ME) of nasal swabs, 17 dogs were excluded due to additionally detected systemic diseases or steroid pre-treatment. Included were 25 dogs with malignant ND (13 carcinomas and 12 sarcomas) and 30 dogs with benign ND (7 benign tumors, 13 idiopathic rhinitis (IR), and 10 others), as well as 10 controls. In none of the 72 dogs with ND was primary bacterial rhinitis diagnosed. Although within the reference interval, compared to the controls, c-CRP was significantly higher in dogs with ND in general and in every subgroup except for benign tumors. Serum HPT concentrations were not different among groups. Compared to the controls, 25(OH)D concentrations were significantly lower (p = 0.041) in malignant ND and sarcomas (p = 0.025). Despite pre-treatment with antibiotics (40/54; 74.1%), in 23/51 (45%) dogs, the ME was positive. Cultivated bacteria did not differ significantly between nasal diseases. The serum markers were not significantly different regarding the positivity of ME. In conclusion, the investigated serum markers were not clinically useful for the reliable detection of canine ND, as was the ME. Because of the low number of dogs with IR and positive or negative ME, further studies regarding c-CRP are needed in a larger group of IR dogs without concomitant diseases to reliably evaluate its utility in IR dogs with suspected secondary bacterial nasal infection. Full article