91 research outputs found

    Low-Energy \Lambda-\p Scattering Parameters from the pp→pK+Λpp \to pK^+\Lambda Reaction

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    Constraints on the spin-averaged Λp\Lambda p scattering length and effective range have been obtained from measurements of the pp→pK+Λpp\to pK^+\Lambda reaction close to the production threshold by comparing model phase-space Dalitz plot occupations with experimental ones. The data fix well the position of the virtual bound state in the Λp\Lambda p system. Combining this with information from elastic Λp\Lambda p scattering measurements at slightly higher energies, together with the fact that the hyperdeuteron is not bound, leads to a new determination of the low energy Λp\Lambda p scattering parameters.Comment: 18 pages, 7 figure

    Tendon-like Electrospun PLGA Scaffolds with Optimized Physical Cues Induced Tenogenic Differentiation and Boosted Immunomodulatory Properties on Amniotic Epithelial Stem Cells.

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    Introduction: The advanced strategies in the field of Tissue Engineering might render possible overcoming the unsatisfactory results of conventional treatments to deal with tendinopathies. In this context, the design of tendon biomimetic electrospun scaffolds engineered with Amniotic Epithelial Stem Cells (AECs), which have shown a high teno-regenerative and immunomodulatory potential in tendon-defect models, can represent a promising solution for tendon regeneration. Methods: Poly(lactide-co-glycolic) acid (PLGA) scaffolds were fabricated using the electrospinning technique to mimic the native tendon biomechanics and extracellular matrix by optimizing: fiber alignment and diameter size (1.27 and 2.5 ”m), and surface chemistry using the Cold Atmospheric Plasma (CAP) Technique. Moreover, the teno-inductive and immunomodulatory effects of these parameters on AECs have been also assessed. Results: The fabricated PLGA scaffolds with highly aligned fibers and small diameter size (1.27 ”m) induced a stepwise tenogenic differentiation on AECs with an early epithelial-mesenchymal transition (EMT), followed by their tenogenic differentiation. Indeed, SCX, an early tendon marker, was significantly more efficiently translated into the downstream effector TNMD, a mature tendon marker. Moreover, 1.27 ”m fiber diameter induced on AECs a higher expression of anti-inflammatory interleukin mRNAs (IL-4 and IL-10). The CAP treated PLGA scaffolds showed an improved cell adhesion and infiltration without altering their topological structure and teno-inductive properties. In fact, AECs engineered with CAP treated fibers, expressed in their cytoplasm TNMD. Moreover, CAP treatment did not alter the mechanical properties of PLGA scaffolds. Conclusions: The developed electrospun PLGA scaffolds with the optimized features represent an ideal tendon-like construct that could be applied in in-vivo models to evaluate their biosafety and teno-regenerative potential

    Benefits of European climate policies for mercury air pollution

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    This paper presents the methodology and results of impact assessment of renewable energy policies on atmospheric emissions of mercury in Europe. The modeling exercise described here involves an interaction of several models. First, a set of energy scenarios has been developed with the REMix (Renewable Energy Mix) model that simulates different levels of penetration of renewable energies in the European power sector. The energy scenarios were input to the GAINS (Greenhouse Gas and Air Pollution Interactions and Synergies) model, which prepared projections of mercury releases to the atmosphere through 2050, based on the current air pollution control policies in each country. Data on mercury emissions from individual sectors were subsequently disaggregated to a fine spatial resolution using various proxy parameters. Finally, the dispersion of mercury in the atmosphere was computed by the chemistry transport model, implemented to the air quality system, Polyphemus. The simulations provided information on changes in concentrations and depositions of various forms of mercury over Europe. Scenarios that simulate a substantial expansion of renewable energies within the power sector indicate extensive co-benefits for mercury abatement, due to the restructuring of the energy system and changes in the fuel mix. The potential for mercury reductions in Europe depends on the rate of fuel switches and renewable technology deployment, but is also influenced by the stringency and timing of the air quality measures. The overall scope for co-benefits is therefore higher in regions relying on coal combustion as a major energy source

    Amniotic Epithelial Stem Cells Counteract Acidic Degradation By-Products of Electrospun PLGA Scaffold by Improving their Immunomodulatory Profile In Vitro

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    Electrospun poly(lactic-co-glycolic acid) (PLGA) scaffolds with highly aligned fibers (ha-PLGA) represent promising materials in the field of tendon tissue engineering (TE) due to their characteristics in mimicking fibrous extracellular matrix (ECM) of tendon native tissue. Among these properties, scaffold biodegradability must be controlled allowing its replacement by a neo-formed native tendon tissue in a controlled manner. In this study, ha-PLGA were subjected to hydrolytic degradation up to 20 weeks, under di-H2 O and PBS conditions according to ISO 10993-13:2010. These were then characterized for their physical, morphological, and mechanical features. In vitro cytotoxicity tests were conducted on ovine amniotic epithelial stem cells (oAECs), up to 7 days, to assess the effect of non-buffered and buffered PLGA by-products at different concentrations on cell viability and their stimuli on oAECs’ immunomodulatory properties. The ha-PLGA scaffolds degraded slowly as evidenced by a slight decrease in mass loss (14%) and average molecular weight (35%), with estimated degradation half-time of about 40 weeks under di-H2 O. The ultrastructure morphology of the scaffolds showed no significant fiber degradation even after 20 weeks, but alteration of fiber alignment was already evident at week 1. Moreover, mechanical properties decreased throughout the degradation times under wet as well as dry PBS conditions. The influence of acid degradation media on oAECs was dose-dependent, with a considerable effect at 7 days’ culture point. This effect was notably reduced by using buffered media. To a certain level, cells were able to compensate the generated inflammation-like microenvironment by upregulating IL-10 gene expression and favoring an anti-inflammatory rather than pro-inflammatory response. These in vitro results are essential to better understand the degradation behavior of ha-PLGA in vivo and the effect of their degradation by-products on affecting cell performance. Indeed, buffering the degradation milieu could represent a promising strategy to balance scaffold degradation. These findings give good hope with reference to the in vivo condition characterized by physiological buffering systems

    Tendon biomimetic 3D scaffold enhance amniotic epithelial stem cells biological potential

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    Tendon tissue engineering represents an emerging field whose aim focuses on the design of 3D tendon biomimetic scaffolds that should ideally combine adequate physical, mechanical, biological and functional properties of the native tissue. In this research, it was designed a bundle tendon-like PLGA 3D scaffold with highly aligned fibers on which the structure and mechanical properties were evaluated. Moreover, it was assessed scaffold’s teno-differentiative and immuno-inductive ability on amniotic epithelial stem cells (AECs). The fabricated PLGA 3D scaffolds mimic macroscopically and microscopically the structure of native tendon tissue and its biomechanical properties. Biologically, AECs seeded on the fabricated 3D scaffolds acquired a spindle tenocyte-like morphology after just 24h compared to the AECs cultured on petri dishes (CTR) which maintained their cobblestone morphology. The phenotypic change of the engineered AECs was also confirmed by visualizing TNMD protein expression, a mature tendon marker, within their cytoplasm and supported by the analysis of tendon-related genes (SCX, COL1, and TNMD) that were significantly upregulated at 7-day culture, while no TNMD protein expression or significant increase in tendon-related genes was found in CTR cells. Moreover, the 3D construct induced on AECs an upregulation of IL-10, an anti-inflammatory cytokine, maintaining basal levels of IL-12, a pro-inflammatory cytokine, showing a favorable IL10/IL12 ratio. In conclusion, the fabricated PLGA 3D scaffolds are tendon biomimetic in terms of ultrastructure and biomechanics, making them also suitable for surgical purposes. Moreover, these constructs revealed a high teno- and immuno-inductive potential on AECs and thus represent potential candidates for tendon regeneration

    Two‐Photon‐Induced CO‐Releasing Molecules as Molecular Logic Systems in Solution, Polymers, and Cells

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    Phototherapeutic applications of carbon monoxide (CO)‐releasing molecules are limited because they require harmful UV and blue light for activation. We describe two‐photon excitation with NIR light (800 nm)‐induced CO‐release from two MnI tricarbonyl complexes bearing 1,8‐naphthalimide units (1, 2). Complex 2 behaves as a logic OR gate in solution, nonwovens, and in HeLa cells. CO release, indicated by fluorescence enhancement, was detected in solution, nonwoven, and HeLa cells by single‐ (405 nm) and two‐photon (800 nm) excitation. The photophysical properties of 1 and 2 have been measured and supported by DFT and TDDFT quantum chemical calculations. Both photoCORMs are stable in the dark in solution and noncytotoxic, leading to promising applications as phototherapeutics with NIR light.Metals in Catalysis, Biomimetics & Inorganic Material

    Black American Maternal Prenatal Choline, Offspring Gestational Age at Birth, and Developmental Predisposition to Mental Illness

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    Black Americans have increased risk for schizophrenia and other mental illnesses with prenatal origins. Prenatal choline promotes infant brain development and behavioral outcomes, but choline has not been specifically assessed in Black Americans. Pregnant women (N = 183, N = 25 Black Americans) enrolled in a study of prenatal stressors and interactions with prenatal choline. Black American women had lower 16-week gestation plasma choline than Whites. Lower choline was not related to obesity, income, or metabolic genotypes. Pregnant women in rural Uganda have higher choline levels than Black American women. Black Americans' lower choline was associated with higher hair cortisol, indicative of higher stress. Lower maternal choline was associated with offsprings' lower gestational age at birth and with decreased auditory P50 inhibition, a marker of inhibitory neuron development. Behavioral development was assessed on the Infant Behavior Questionnaire-R-SF (IBQ-R) at 3 months. Lower Black American maternal gestational choline was associated with lower infant IBQ-R Orienting/Regulation, indicating decreased attention and relation to caregivers. Additional evidence for developmental effects of choline in Black Americans comes from a randomized clinical trial of gestational phosphatidylcholine supplementation versus placebo that included 15 Black Americans. Phosphatidylcholine increased gestational age at birth and newborn P50 inhibition and decreased Social Withdrawn and Attention problems at 40 months of age in Black Americans' offspring compared to placebo. Inhibitory and behavioral deficits associated with lower prenatal choline in offspring of Black American women indicate potential developmental predispositions to later mental illnesses that might be ameliorated by prenatal choline or phosphatidylcholine supplementation

    Total Cross Section of the Reaction pp \to pK^+\Lambda Close to Threshold

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    The energy dependence of the total cross section for the pp \to pK^+\Lambda reaction was measured in the threshold region covering the excess energy range up to 7MeV. Existing model calculations describe the slope of the measured cross sections well, but are too low by a factor of two to three in rate. The data were used for a precise determination of the beam momentum of the COSY-synchrotron.Comment: 11 pages, 5 figure
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