879 research outputs found

    The potential impacts of micro-and-nano plastics on various organ systems in humans

    Get PDF
    Humans are exposed to micro-and-nano plastics (MNPs) through various routes, but the adverse health effects of MNPs on different organ systems are not yet fully understood. This review aims to provide an overview of the potential impacts of MNPs on various organ systems and identify knowledge gaps in current research. The summarized results suggest that exposure to MNPs can lead to health effects through oxidative stress, inflammation, immune dysfunction, altered biochemical and energy metabolism, impaired cell proliferation, disrupted microbial metabolic pathways, abnormal organ development, and carcinogenicity. There is limited human data on the health effects of MNPs, despite evidence from animal and cellular studies. Most of the published research has focused on specific types of MNPs to assess their toxicity, while other types of plastic particles commonly found in the environment remain unstudied. Future studies should investigate MNPs exposure by considering realistic concentrations, dose-dependent effects, individual susceptibility, and confounding factors

    Formación en Cinemática y Dinámica de Sistemas Multicuerpo Mediante Coordenadas Naturales

    Full text link
    La formación de los futuros ingenieros mecánicos en dinámica de sistemas multicuerpo 3-D rara vez encuentra una materia específica en los planes de estudio, ni siquiera en postgrado. Cuando sólo se dispone de algunas horas (entre 5 y 10 horas de clase y unas 15 de trabajo personal) en el marco de una materia más general, las coordenadas naturales y Matlab son probablemente el único camino para alcanzar ciertos objetivos prácticos. Aquí se aborda cómo se pueden alcanzar estos objetivos, con un aprendizaje basado en .casos reales. Very often, the curriculum of mechanical engineers doesn't include any specific subject on kinematics and dynamics of multibody systems. In these situations the unique opportunity to introduce MBS is to dedicate from 5 to 10 hours to this subject inside a more general course, plus about 15 hours of personal work. This paper shows how this short time can be enough if natural coordinates are used. Keywords

    Bioactivity of wollastonite/aerogels composites obtained from a TEOS-MTES matrix

    Get PDF
    Organic-inorganic hybrid materials were synthesized by controlled hydrolysis of tetraethoxysilane (TEOS), methyltrimethoxysilane (MTES), synthetic wollastonite powders and polydimethylsiloxane (PDMS) in an ethanol solution. Aerogels were prepared from acid hydrolysis of TEOS and MTES with different volume ratio in ethanol, followed by addition of wollastonite powder and PDMS in order to obtain aerogels with 20 wt% of PDMS and 5 wt% of CaO of the total silica. Finally, when the wet gels were obtained, they were supercritically dried at 260°C and 90 bar, in ethanol. In order to obtain its bioactivity, one method for surface activation is based on a wet chemical alkaline treatment. The particular interest of this study is that we introduce hybrid aerogels, in a 1 M solution of NaOH, for 30 s at room temperature. We evaluate the bioactivity of TEOS-MTES aerogel when immersed in a static volume of simulated body fluid (SBF). An apatite layer of spherical-shaped particles of uniform size smaller than 5 microns is observed to form on the surface of the aerogels after 25 days soaking in SBF.Ministerio de Ciencia e Innovación MAT2005-01583Junta de Andalucía TEP 79

    Enhanced endosomal signaling and desensitization of GLP-1R versus GIPR in pancreatic beta cells

    Get PDF
    The incretin receptors, glucagon-like peptide-1 receptor (GLP-1R) and glucose-dependent insulinotropic polypeptide receptor (GIPR), are prime therapeutic targets for the treatment of type 2 diabetes (T2D) and obesity. They are expressed in pancreatic beta cells where they potentiate insulin release in response to food intake. Despite GIP being the main incretin in healthy individuals, GLP-1R has been favored as a therapeutic target due to blunted GIPR responses in T2D patients and conflicting effects of GIPR agonists and antagonists in improving glucose tolerance and preventing weight gain. There is, however, a recently renewed interest in GIPR biology following the realization that GIPR responses can be restored after an initial period of blood glucose normalization and the recent development of dual GLP-1R/GIPR agonists with superior capacity for controlling blood glucose levels and weight. The importance of GLP-1R trafficking and subcellular signaling in the control of receptor outputs is well established, but little is known about the pattern of spatiotemporal signaling from the GIPR in beta cells. Here, we have directly compared surface expression, trafficking and signaling characteristics of both incretin receptors in pancreatic beta cells to identify potential differences that might underlie distinct pharmacological responses associated with each receptor. Our results indicate increased cell surface levels, internalization, degradation, and endosomal versus plasma membrane activity for the GLP-1R, while the GIPR is instead associated with increased plasma membrane recycling, reduced desensitization, and enhanced downstream signal amplification. These differences might have potential implications for the capacity of each incretin receptor to control beta cell function

    Systematics and evolution of the needle grasses (Poaceae: Pooideae: Stipeae) based on analysis of multiple chloroplast loci, ITS, and lemma micromorphology

    Get PDF
    27 p.We conducted a molecular phylogenetic study of the tribe Stipeae using nine plastid DNA sequences (trnK-matK, matK, trnH-psbA, trnL-F, rps3, ndhF, rpl32-trnL, rps16-trnK, rps16 intron), the nuclear ITS DNA regions, and micromorphological characters from the lemma surface. Our large original dataset includes 156 accessions representing 139 species of Stipeae representing all genera currently placed in the tribe. The maximum likelihood and Bayesian analyses of DNA sequences provide strong support for the monophyly of Stipeae; including, in phylogenetic order, Macrochloa as remote sister lineage to all other Stipeae, then a primary stepwise divergence of three deep lineages with a saw-like (SL) lemma epidermal pattern (a plesiomorphic state). The next split is between a lineage (SL1) which bifurcates into separate Eurasian and American clades, and a lineage of three parts; a small Patis (SL2) clade, as sister to Piptatherum s.str. (SL3), and the achnatheroid clade (AC). The AC exhibits a maize-like lemma epidermal pattern throughout. AC consists of a core clade of Austral-Eurasian distribution and a “major American clade” of North and South American distribution. The base chromosome number for Stipeae is somewhat ambiguous but based on our survey it seems most likely to be x = 11 or 12. Our phylogenetic hypothesis supports the recognition of the following genera and groups (listed by region): Eurasia—Achnatherum, “Miliacea group”, “Neotrinia” (monotypic), Orthoraphium (monotypic), Patis (also 1 from North America), Piptatherum s.str., Psammochloa (monotypic), Ptilagrostis, Stipa, “Timouria group”, and Trikeraia; Mediterranean—Ampelodesmos (monotypic), Celtica (monotypic), Macrochloa (monotypic), and “Stipella-Inaequiglumes group”; Australasia —Anemanthele (monotypic), and Austrostipa; North America (NA)—“Eriocoma group”, Hesperostipa, Oryzopsis (monotypic), Piptatheropsis, “Pseudoeriocoma group”, and “Stillmania” (monotypic); South America—Aciachne, Amelichloa (also NA), Anatherostipa (s.str.), Jarava (polyphyletic), Lorenzochloa, Nassella (also NA), Ortachne, Pappostipa (also NA), and Piptochaetium (also NA). Monophyly of Phaenospermateae including Duthieinae is demonstrated, and its inclusion within or treatment as sister to Stipeae is rejected.Peer reviewe

    Contribución al estudio biológico de la tintorera (Prionace glauca) capturada accidentalmente en la pesquería de palangre de superficie de pez espada en el Mediterráneo occidental

    Get PDF
    Blue shark (Prionace glauca) bycatches in the Spanish surface longline fisheries in the Mediterranean targeting swordfish (Xiphias gladius) from 1999 to 2001 represented 2% of the total catch. Information from onboard observers during 861 fishing sets in 26 longliners indicated that the highest catches were made in area 4-35000 (Alboran Sea) which represents 75.6% of the total observed catch of blue shark. The observed CPUE are from 5.5 to 34.1 kg/1000 hooks. Mean size at capture (LJFL) was 141.6 cm (SD=35.88). The proportion of females from the total was 0.5.Les prises accessoires de requin peau-bleue (Prionace glauca) des pêcheries espagnoles à la palangre de surface qui ciblent l’espadon (Xiphias gladius) dans la Méditerranée entre 1999 et 2001 ont représenté 2% de la capture totale. L’information recueillie par les observateurs à bord de 26 palangriers visant l’espadon durant 861 opérations de pêche a indiqué que les plus fortes captures se produisent dans la zone 4-35000 (mer d’Alboran) qui représente 75,6% du total de la capture observée du requin peau-bleue. Les CPUE observées se situent entre 5,5 et 34,1 kg/1.000 hameçons. La taille moyenne de capture (LJFL) était de 141,6 cm (DS=35,88). Le pourcentage des femelles par rapport au total était de 0,5.Las capturas de tintorera (Prionace glauca) como especie accesoria en las pesquerías españolas de palangre de superficie dirigido al pez espada (Xiphias gladius) en el Mediterráneo entre 1999 y 2001 representó el 2% de la captura total. La información tomada por observadores a bordo durante de 861 caladas en 26 palangreros de pez espada indicó que las mayores capturas se producen en el área 4-35000 (Mar de Alborán) que representa el 75.6% del total de captura observada de la especie. Las CPUE observadas se encuentran entre 5.5 y 34.1 kg/1000 anzuelos. La talla media de captura (LJFL) fue de 1 41.6 cm (DE=35.88). El porcentaje de hembras respecto al total fue de 0.5

    Verbal Memory and IQ Predict Adaptive Behavior in Children and Adolescents with High-Functioning Autism Spectrum Disorders

    Get PDF
    Adaptive deficits are commonly found in high functioning autism spectrum disorders (HF-ASD) despite of cognitive potential. Most studies have focused on the relationships between adaptive behavior and intellectual quotient (IQ) and have used correlations to study relationships between them. Few studies have analyzed cognitive variables other than IQ as potential predictors of adaptive behavior in HF-ASD using regression methods. This study aimed to analyze the impact of several cognitive variables on adaptive behavior in a sample of children and adolescents with HF-ASD. METHODS: Sample included 16 child and adolescent boys with HF-ASD (age between 7-17 years). Cognitive assessment included measures of general intelligence, visual memory, verbal memory, working memory and problem solving/flexibility tests. Vineland Adaptive Behavior Scales (VABS) was used to evaluate adaptive behavior. To establish the predictive capacity of the cognitive variables for adaptive functioning, linear regression models were fitted for each adaptive domain using a stepwise method. RESULTS: Verbal memory and IQ emerged as the main independent predictors for VABS adaptive scores. The 41% of the variance in Communication was predicted by IQ. The 35% of the variance in Daily Living Skills was predicted by verbal memory. Almost half of the variance in Socialization was predicted by both, verbal memory and IQ (49%). No other cognitive functions were associated with adaptive scores. CONCLUSIONS: The results highlight the strong impact of IQ and verbal memory on adaptive behavior in HF-ASD patients. These findings could contribute to identify potential targets of intervention

    Analysis of video guides with multimedia annotations

    Get PDF
    Las guías docentes son de obligado cumplimiento para la evaluación de los programas, como un recurso importante para informar a los estudiantes universitarios. Sin embargo, la realidad es otra, en la práctica no suelen leerlas. La investigación analiza un proyecto que convierte la guías docentes en recursos más interactivos y atractivos mediante videoguías y anotaciones de vídeo con etiquetado social. Con diseño mixto de investigación preguntamos: a. conocimiento sobre las guías, b. Valoración de las videoguías, y c. satisfacción sobre las anotaciones de vídeo. Una muestra con 132 estudiantes de diferentes cursos y grados de educación de dos universidades españolas. Encontramos un alto nº de estudiantes que no leen las guías docentes o con poco detalle (91,7%), valorando muy positivamente el formato de videoguías como la metodología de anotaciones de vídeo a pesar de no tener experiencias previas (90,4%)The teaching guides are mandatory for the evaluation of the programs, as an important resource to inform university students. however, the reality is different, in practice they are not usually read. The research analyzes a project that converts teaching guides into more interactive and attractive resources through video guides and video annotations with social tagging. With a mixed research design we asked: a. knowledge about the guides, b. assessment of the video guides, and c. satisfaction with the video annotations. A sample of 132 students from different courses and degrees of education from two Spanish universities. We found a high number of students who do not read the teaching guides or with little detail (91.7%), valuing very positively the format of videoguides as the methodology of video annotations despite not having previous experience (90.4%
    corecore