445 research outputs found

    Stabilization of the cubic phase of HfO2 by Y addition in films grown by metal organic chemical vapor deposition

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    Addition of yttrium in HfO2 thin films prepared on silicon by metal organic chemical vapor deposition is investigated in a wide compositional range (2.0-99.5 at. %). The cubic structure of HfO2 is stabilized for 6.5 at. %. The permittivity is maximum for yttrium content of 6.5-10 at. %; in this range, the effective permittivity, which results from the contribution of both the cubic phase and silicate phase, is of 22. These films exhibit low leakage current density (5x10(-7) A/cm(2) at -1 V for a 6.4 nm film). The cubic phase is stable upon postdeposition high temperature annealing at 900 degrees C under NH3. (c) 2006 American Institute of Physics

    Determination of iodine value of palm oil based on triglyceride composition

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    The triglyceride (TG) composition of palm oil is normally determined by high-performance liquid chromatography (HPLC). The HPLC chromatograms indicated a good separation of most of the TG components in the oil. The TG can be classified based on either the TG groups, i.e., triunsaturated, monosaturated, disaturated, or trisaturated, or the number of double bonds, i.e., zero, one, two, three, or four double bonds. The more unsaturated the fatty acid, the greater the iodine value (IV). Therefore, it is hypothesized that the IV of an oil can be determined based upon the TG composition of the oil. Based on the TG groups, stepwise regression analysis showed that the areas of the disaturated, trisaturated, and triunsaturated TG peaks could predict the IV with a coefficient of determination (R2) of 0.990. The regression based on the number of double bonds yielded a good regression equation with R2=0.992. The important variables were the peak area of the fatty acids that contained zero, one, two, and three double bonds. This study concludes that the TG composition can be used to predict the IV of palm oil. The best prediction model is obtained by using the number of double bonds in the TG as the independent variable

    Poemes en la boira

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    Engineering the Magnetic Transition Temperatures and the Rare Earth Exchange Interaction in Oxide Heterostructures

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    The properties of functional oxide heterostructures are strongly influenced by the physics governing their interfaces. Modern deposition techniques allow us to accurately engineer the interface physics through the growth of atomically precise heterostructures. This enables minute control over the electronic, magnetic, and structural characteristics. Here, we investigate the magnetic properties of tailor-made superlattices employing the ferromagnetic and insulating double perovskites RE2_2NiMnO6_6 (RE = La, Nd), featuring distinct Curie temperatures. Adjusting the superlattice periodicity at the unit cell level allows us to engineer their magnetic phase diagram. Large periodicity superlattices conserve the individual para- to ferromagnetic transitions of the La2_2NiMnO6_6 and Nd2_2NiMnO6_6 parent compounds. As the superlattice periodicity is reduced, the Curie temperatures of the superlattice constituents converge and, finally, collapse into one single transition for the lowest period samples. This is a consequence of the magnetic order parameter propagating across the superlattice interfaces, as supported by a minimal Landau theory model. Further, we find that the Nd-Ni/Mn exchange interaction can be enhanced by the superlattice interfaces. This leads to a field-induced reversal of the Nd magnetic moments, as confirmed by synchrotron X-ray magnetic circular dichroism measurements and supported by first-principles calculations. Our work demonstrates how superlattice engineering can be employed to fine-tune the magnetic properties in oxide heterostructures and broadens our understanding of magnetic interfacial effects

    Lithium halide filled carbon nanocapsules: Paving the way towards lithium neutron capture therapy (LiNCT)

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    Neutron capture therapy (NCT) is a form of radiotherapy that exploits the potential of some specific isotopes to capture thermal neutrons and subsequently yield high linear energy transfer (LET) particles, suitable for cancer treatment. Recently, relevant technological improvements have been made in terms of accelerators as suitable neutron sources for NCT at hospitals. However, low selective delivery of current drugs to cancer cells remains as the main challenge for successful clinical application of NCT. This work presents an innovative and previously unexplored approach for the design of nanotherapeutic NCT agents. Herein, a new concept based on carbon nanomaterials that seal 6Li active NCT nuclides is investigated. The 6Li active species are located in the inner cavity of the nanocarrier (carbon nanohorns or carbon nanotubes) and therefore, completely protected from the biological environment, avoiding toxicity and degradation. After encapsulation of the active cargo, the external surface of the nanocarrier is modified for improved biocompatibility. The developed 6Li-filled carbon nanohorns offered the possibility to explore 6Li compounds as active NCT agents by delivering therapeutic doses to cancer cells. We envisage that nanoencapsulation of 6Li can trigger the successful development and implementation of Lithium Neutron Cancer Therapy (LiNCT)

    Accounting for unmet needs resulting from cancer-related cognitive impairment

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    Purpose: Cancer-related cognitive impairment (CRCI) causes a wide range of unmet needs for cancer survivors. It is unknown which clinical, demographic, cognitive, and psychological factors underpin and account for these various unmet needs. This study aimed to (a) identify factors associated with CRCI-related unmet needs, and (b) establish the most pertinent factors that account for CRCI-related unmet needs. Methods: Four hundred and fifty-six (n = 456) cancer survivors responded to a range of demographic and clinical questions, as well as measures of CRCI-related unmet needs (MASCC COG-IMPACT), perceived cognitive impairment (PROMIS-COG), and psychological distress (DASS-21). Descriptive statistics, bivariate correlations, and feed-forward multiple regression analyses were completed. Results: Cognitive impairment severity (r = 0.39 to 0.59; p \u3c 0.01), psychological distress (r = 0.36 to 0.58; p \u3c 0.01), and time since diagnosis (r = − 0.11 to − 0.20; p \u3c 0.05 to p = 0.02) were significantly associated with CRCI-related unmet needs across all domains. Age (r = − 0.10 to − 0.22; p \u3c 0.001 to p = 0.03), stage of cancer at initial diagnosis (r = 0.10 to 0.13; p \u3c 0.001 to p = 0.04), stage of cancer at most progressed (r = 0.11 to 0.18; p \u3c 0.001 to p = 0.03), and sex (r = 0.12; p = 0.01; females experiencing greater unmet needs than males), were significantly associated with one or more domains of unmet need. Cognitive impairment severity and psychological distress were the most pertinent factors accounting for CRCI-related unmet needs (R2 = 0.245, F(3, 487) = 48.96, p \u3c 0.001 to R2 = 0.474, F(3, 487) = 114.81, p \u3c 0.001), explaining 24.5% to 47.4% of the variance. Conclusion: Cognitive impairment severity and psychological distress were the most key factors in accounting for CRCI-related unmet needs. Other variables, while associated with CRCI-related unmet needs, did not provide additional predictive utility. Implications for Cancer Survivors: The results may inform the choice of supportive care targets, and future strategies, to improve supportive care for people experiencing cancer-related cognitive impairment

    NAD+ Precursors and Intestinal Inflammation : Therapeutic Insights Involving Gut Microbiota

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    The oxidized form of nicotinamide adenine dinucleotide (NAD+) is a critical metabolite for living cells. NAD+ may act either as a cofactor for many cellular reactions as well as a coenzyme for different NAD+-consuming enzymes involved in the physiological homeostasis of different organs and systems. In mammals, NAD+ is synthesized from either tryptophan or other vitamin B3 intermediates that act as NAD+ precursors. Recent research suggests that NAD+ precursors play a crucial role in maintaining the integrity of the gut barrier. Indeed, its deficiency has been associated with enhanced gut inflammation and leakage, and dysbiosis. Conversely, NAD+-increasing therapies may confer protection against intestinal inflammation in experimental conditions and human patients, with accumulating evidence indicating that such favorable effects could be, at least in part, mediated by concomitant changes in the composition of intestinal microbiota. However, the mechanisms by which NAD+-based treatments affect the microbiota are still poorly understood. In this context, we have focused specifically on the impact of NAD+ deficiency on intestinal inflammation and dysbiosis in animal and human models. We have further explored the relationship between NAD+ and improved host intestinal metabolism and immunity and the composition of microbiota in vivo. Overall, this comprehensive review aims to provide a new perspective on the effect of NAD+-increasing strategies on host intestinal physiology

    The lipidomic profile is associated with the dietary pattern in subjects with and without diabetes mellitus from a Mediterranean area

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    Lipid functions can be influenced by genetics, age, disease states, and lifestyle factors, particularly dietary patterns, which are crucial in diabetes management. Lipidomics is an expanding field involving the comprehensive exploration of lipids from biological samples. In this cross-sectional study, 396 participants from a Mediterranean region, including individuals with type 1 diabetes (T1D), type 2 diabetes (T2D), and non-diabetic individuals, underwent lipidomic profiling and dietary assessment. Participants completed validated food frequency questionnaires, and lipid analysis was conducted using ultra-high-performance liquid chromatography coupled with mass spectrometry (UHPLC/MS). Multiple linear regression models were used to determine the association between lipid features and dietary patterns. Across all subjects, acylcarnitines (AcCa) and triglycerides (TG) displayed negative associations with the alternate Healthy Eating Index (aHEI), indicating a link between lipidomic profiles and dietary habits. Various lipid species (LS) showed positive and negative associations with dietary carbohydrates, fats, and proteins. Notably, in the interaction analysis between diabetes and the aHEI, we found some lysophosphatidylcholines (LPC) that showed a similar direction with respect to aHEI in non-diabetic individuals and T2D subjects, while an opposite direction was observed in T1D subjects. The study highlights the significant association between lipidomic profiles and dietary habits in people with and without diabetes, particularly emphasizing the role of healthy dietary choices, as reflected by the aHEI, in modulating lipid concentrations. These findings underscore the importance of dietary interventions to improve metabolic health outcomes, especially in the context of diabetes management.This work was funded by the Spanish Ministry of Health, Instituto de Salud Carlos III (Madrid, Spain) grants PI15/0625 (to D.M. and E.C.) and PI18/0328 (to D.M.). Additionally, it received support from CIBER-Consorcio Centro de Investigación Biomédica en Red- (CB15/00071), Instituto de Salud Carlos III, Ministerio de Ciencia e Innovación, Spain. M.I.R.-L. holds a predoctoral grant SLT017/20/000107 from Pla Estratègic de Recerca i Innovació en Salut (PERIS) 2021–2024 of Generalitat de Catalunya. J.J. was recipient of a Miguel Servet Type 2 contract (CPII18/00004; ISCIII). Institut d’Investigació Biomèdica Sant Pau and Biomedical Research Institute’s Dr. Pifarré Foundation from Lleida (IRBLleida) are accredited by the Generalitat de Catalunya as Centre de Recerca de Catalunya (CERCA).Peer ReviewedPostprint (published version

    Observations and Dynamical Implications of Active Normal Faulting in South Peru

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    Orogenic plateaus can exist in a delicate balance in which the buoyancy forces due to gravity acting on the high topography and thick crust of the plateau interior are balanced by the compressional forces acting across their forelands. Any shortening or extension within a plateau can indicate a perturbation to this force balance. In this study we present new observations of the kinematics, morphology and slip rates of active normal faults in the South Peruvian Altiplano obtained from field studies, high-resolution DEMs, Quaternary dating and remote sensing. We then investigate the implications of this faulting for the forces acting on the Andes. We find that the mountains are extending NNE-SSW to NE-SW along a normal fault system that cuts obliquely across the Altiplano plateau, which in many places reactivates Miocene-age reverse faults. Radiocarbon dating of offset late Quaternary moraines and alluvial fan surfaces indicates horizontal extension rates across the fault system of between 1 and 4 mm/yr — equivalent to an extensional strain rate in the range of 0.5-2×10−8 1/yr averaged across the plateau. We suggest the rate and pattern of extension implies there has been a change in the forces exerted between the foreland and the Andes mountains. A reduction in the average shear stresses on the sub-Andean foreland detachment of <4 MPa (<20-25% of the total force) can account for the rate of extension. These results show that, within a mountain belt, the pattern of faulting is sensitive to small spatial and temporal variations in the strength of faults along their margins
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