4,448 research outputs found

    Analysis of Secondary Adhesion Wear Mechanism on Hard Machining of Titanium Aerospace Alloy

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    Titanium alloys are widely used in important manufacturing sectors such as the aerospace industry, internal components of motor or biomechanical components, for the development of functional prostheses. The relationship between mechanical properties and weight and its excellent biocompatibility have positioned this material among the most demanded for specific applications. However, it is necessary to consider the low machinability as a disadvantage in the titanium alloys features. This fact is especially due to the low thermal conductivity, producing significant increases in the temperature of the contact area during the machining process. In this aspect, one of the main objectives of strategic industries is focused on the improvement of the efficiency and the increase of the service life of the elements involved in the machining of this alloy. With the aim to understand the most relevant effects in the machinability of the Ti6Al4V alloy, an analysis is required of different variables of the machining process like tool wear evolution, based on secondary adhesion mechanisms, and the relation between surface roughness of the work-pieces with the cutting parameters. In this research work, a study on the machinability of Ti6Al4V titanium alloy has been performed. For that purpose, in a horizontal turning process, the influence of cutting tool wear effects has been evaluated on the surface finish of the machined element. As a result, parametric behavior models for average roughness (Ra) have been determined as a function of the machining parameters used

    Misprescription of antibiotics in primary care: a critical systematic review of its determinants

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    Background Antibiotic resistance is one of the principal public health problems worldwide. Currently, inappropriate use of antibiotics is regarded as the principal determinant of resistance, with most of these drugs being prescribed outside a hospital setting. This systematic review sought to identify the factors, attitudes and knowledge linked to misprescription of antibiotics. Methods A systematic review was conducted using the MEDLINE-PubMed and EMBASE databases. The selection criteria required that papers: (1) be published in English or Spanish; (2) designate their objective as that of addressing attitudes/ knowledge or other factors related with the prescribing of antibiotics; and (3) use quality and/or quantity indicators to define misprescription. The following were excluded: any paper that used qualitative methodology and any paper that included descriptive analysis only. Results A total of 46 papers that met the inclusion criteria were included in the review. They were very heterogeneous and displayed major methodological limitations. Doctors’ socio-demographic and personal factors did not appear to exert much influence. Complacency (fulfilling what professionals perceived as being patients’/parents’ expectations) and, to a lesser extent, fear (fear of possible complications in the patient) were the attitudes associated with misprescription of antibiotics. Conclusions Before designing interventions aimed at improving the prescription and use of antibiotics, studies are needed to identify precisely which factors influence prescribing

    Students frequently ask: ‘Yes but...What is the utility of physics?’

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    Two Teaching Innovation Projects were carried out in the framework of the subjects ‘Physics I’ and ‘Physics II’ for different Degrees on Engineering at the Engineering High School of the University of Cadiz, Spain, during the 2013-2014 course. The aim of these Projects was to catch the interest of first course students on physical phenomena and principles, a matter frequently considered as ‘difficult’ or even ‘boring’ for them when it is approached from an excessively formal scope. The methodology of the two Projects was based on experiments of Recreational Physics, different toys and devices, and other resources as posters, books and online contents. The Projects were conducted during Theory, Laboratory, and Online classes of Physics I and II, and their results were evaluated from questionnaires to the students. Main conclusions derived from them were: i) a significant increment on the interest of students on Physics and Science; ii) the aim of students for learning more about this kind of recreational physical experiments; and iii) a general sensation of enjoying the study and analysis of physical phenomena by students –and teachers as well–. In addition, students manifested their interest in this methodology to be applied to other Engineering subjects of their Degrees

    Factores familiares asociados a los Trastornos Alimentarios: una revisión

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    From a multifactorial perspective this study present a review about the family factors associated to eating disorders, considering theoretical and empirical contributions in national and international journals articles . The find of the research about the Eating Disorders and Family, indicate that the principal topics investigated are: family functioning, daughters and fathers relationships, stressful experiences, family psychopathology, attitudes and behaviors about weigh, eating and body image in the affected families. We conclude recognizing the heterogeneity of the families with Eating Disorders and the complex combination of family factors associated to eating psychopathology. More research is suggested about: family functioning in EDNOS patients, the father´s role, protective factors, coping stress, body image and family food

    Changes in Cu accumulation and fractionation along soil depth in acid soils of vineyards and abandoned vineyards (now forests)

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    Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGThis study investigated changes in copper accumulation and fractionation based on the depth of soils obtained from active and abandoned vineyards. Soil samples were collected at different depths in three areas with active and abandoned vineyards, and the concentrations of total copper and copper fractions were measured in these soil samples. Results revealed that in active vineyards, total copper accumulation was the highest in the first layer of soil (depth = 0–2 cm), with concentrations (193–892 mg kg−1) considerably higher than those in the deepest soil layer (depth = 40–50 cm; concentration = 63–71 mg kg−1). This accumulation was significantly correlated with the total carbon concentration in the soil. However, the total copper concentration in abandoned vineyards (84–374 mg kg−1) was the highest in the subsurface layers (depth = 10–15 cm) and was not significantly correlated with the total carbon content. Moreover, the percentage of available copper was lower in abandoned vineyards than in active vineyards. In terms of copper fractionation, the main fraction in active vineyard soil was copper bound to organic matter, whereas the main fraction in abandoned vineyard soil was residual copper. Therefore, vineyard abandonment and its transformation into forest changed the distribution and fractionation of copper based on soil depth, thus decreasing the amount of available copper and improving the soil quality, which could enable new ecosystems.Xunta de Galicia | Ref. ED431F 2018/06Ministerio de Economía | Ref. RYC-2016–20411Xunta de Galicia | Ref. ED481D-2021/01

    Attitudes of primary care physicians to the prescribing of antibiotics and antimicrobial resistance: a qualitative study from Spain.

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    BACKGROUND AND OBJECTIVE: Resistance to antibiotics is a public health threat. A number of studies confirm the relationship between antibiotic use and the resistance rate. As a whole, physicians represent a large proportion of the health professionals involved in the use of this therapeutic group. Our study therefore sought to ascertain the opinions and attitudes of GPs in Spain with respect to antibiotics and resistance. METHODS: We used the focus group (FG) method, with each group comprising 4-12 primary care physicians and a moderator. Based on a previous systematic review, we drew up an agenda to be followed during the holding of the sessions. Group proceedings were recorded and the transcriptions then analysed separately by two researchers. RESULTS: Five FGs were formed, including a total of 33 physicians. The factors/attitudes that influenced the prescribing of antibiotics by GPs were fear, complacency, insufficient knowledge and external responsibility of the pharmaceutical industry, patients and over-the-counter antibiotics. The groups felt that antibiotic resistance was not a problem at a community level. CONCLUSIONS: Identification of attitudes/knowledge related with inappropriate antibiotic prescribing will enable specific interventions to be designed, with the aim of targeting these shortcomings to improve antibiotic use and help reduce resistance

    ISG15 Is a Novel Regulator of Lipid Metabolism during Vaccinia Virus Infection.

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    Interferon-stimulated gene 15 (ISG15) is a 15-kDa ubiquitin-like modifier that binds to target proteins in a process termed ISGylation. ISG15, first described as an antiviral molecule against many viruses, participates in numerous cellular processes, from immune modulation to the regulation of genome stability. Interestingly, the role of ISG15 as a regulator of cell metabolism has recently gained strength. We previously described ISG15 as a regulator of mitochondrial functions in bone marrow-derived macrophages (BMDMs) in the context of Vaccinia virus (VACV) infection. Here, we demonstrate that ISG15 regulates lipid metabolism in BMDMs and that ISG15 is necessary to modulate the impact of VACV infection on lipid metabolism. We show that Isg15-/- BMDMs demonstrate alterations in the levels of several key proteins of lipid metabolism that result in differences in the lipid profile compared with Isg15+/+ (wild-type [WT]) BMDMs. Specifically, Isg15-/- BMDMs present reduced levels of neutral lipids, reflected by decreased lipid droplet number. These alterations are linked to increased levels of lipases and are independent of enhanced fatty acid oxidation (FAO). Moreover, we demonstrate that VACV causes a dysregulation in the proteomes of BMDMs and alterations in the lipid content of these cells, which appear exacerbated in Isg15-/- BMDMs. Such metabolic changes are likely caused by increased expression of the metabolic regulators peroxisome proliferator-activated receptor-γ (PPARγ) and PPARγ coactivator-1α (PGC-1α). In summary, our results highlight that ISG15 controls BMDM lipid metabolism during viral infections, suggesting that ISG15 is an important host factor to restrain VACV impact on cell metabolism. IMPORTANCE The functions of ISG15 are continuously expanding, and growing evidence supports its role as a relevant modulator of cell metabolism. In this work, we highlight how the absence of ISG15 impacts macrophage lipid metabolism in the context of viral infections and how poxviruses modulate metabolism to ensure successful replication. Our results open the door to new advances in the comprehension of macrophage immunometabolism and the interaction between VACV and the host.We thank the expert technical assistance of Sara Sandoval. We are grateful to Miguel Sánchez-Álvarez who has kindly provided several commercial reagents. We would like to thank the Spanish National Plan for Scientific and Technical Research and Innovation (Plan Estatal de Investigación Científica y Técnica y de Innovación), (Ministry of Health of Spain, State Secretary of R1D and FEDER/FSE).S

    Effects of irrigation with rich-arsenic water on an arugula (Eruca sativa L.) crop

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    Large areas of Chaco Pampean plain have aquifers containing high arsenic values. The use of these waters to irrigate horticultural species, in particular, those for fresh consumption could have direct effects on human health as well as on agricultural soils. The aim of this work was to evaluate the arsenic content in the species Eruca sativa L (arugula) and also to evaluate the soil when applying irrigation with waters prepared in the laboratory with different arsenic concentration and alkalinity. An assay with DBCA design and factorial arrangement was performed (soil type/alkalinity/As level) employing two types of soils with different textures (sandy loam and silty loam), developing 20 plants per pot. Pots were kept at 90% of field capacity with daily irrigation using water of different alkalinity and arsenic concentration. Three concentrations of arsenic were used (100, 250 and 500 μg.L-1), employing the starting water (not modified by As) as witness. Variables evaluated were vegetal dry matter and arsenic concentration in plant and soil. Irrigation conditions affected the arsenic content in the plant reaching toxicity levels similar to those cited in the literature, particularly in silty loam soil. Although the increase of arsenic concentration is evident in vegetal, it is not possible to establish a reliable relation between the arsenic concentration in the vegetal and the plant yield. Moreover, the arsenic content in the soil also increased with the irrigation showing higher levels in silty loam soil without reaching hazard limits in the first sowing. It is possible to conclude that although the arsenic concentration in fresh vegetal is within limits established by the legislation, its consumption could contribute to the daily intake of arsenic which, in turn, could add to the hazard of drinking water with arsenic.Amplias zonas de la planicie Chaco-Pampeana presentan acuíferos de los que se extrae agua que contiene valores elevados de arsénico. El empleo de este tipo de agua en el riego de especies hortícolas, particularmente de consumo fresco, podría tener consecuencias sanitarias directas sobre la población y también afectar los suelos. Los objetivos del trabajo se encuentran dirigidos a la evaluación del contenido de As en la especie Eruca sativa L. (rúcula) y en el suelo de cultivo al aplicar riego con aguas preparadas en el laboratorio con diferente concentración de As y alcalinidad. Se realiza un ensayo con diseño DBCA y arreglo factorial (tipo de suelo/ alcalinidad del agua/nivel As) empleando dos suelos texturalmente distintos (franco-arenoso y franco-limoso), con el desarrollo de 20 plantas por maceta. Las macetas se mantuvieron al 90% de la capacidad de campo (riegos diarios con dos tipos de agua de diferente alcalinidad) y 3 concentraciones de As (100, 250 y 500 μg.L-1), empleando agua sin modificar como testigo. Las variables evaluadas fueron materia seca vegetal y concentración de As en planta y suelo. Las condiciones de riego afectaron el tenor de As en planta alcanzando niveles de toxicidad similares a los citados en la literatura, particularmente en el suelo franco-limoso. Si bien es evidente el aumento de la concentración de As en vegetal, no es posible establecer una relación fehaciente entre la concentración de As en el vegetal y el rendimiento. El contenido de As en el suelo también aumentó con el riego, observándose mayores niveles en el suelo franco-limoso, sin alcanzar los límites de peligrosidad en una primera siembra. Puede concluirse que si bien la concentración de As en vegetal fresco se encuentra dentro de los límites establecidos por la Legislación, su consumo podría significar un aporte a la ingesta diaria de As, que se sumaría a los perjuicios ocasionados por el agua de bebida.Fil: Castillo, Nadia Sabiela. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales; ArgentinaFil: Franco, Maria Luisina. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales; ArgentinaFil: González, María José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; Argentina. Universidad Nacional de la Plata. Facultad de Ciencias Naturales y Museo. Instituto de Recursos Minerales. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto de Recursos Minerales; ArgentinaFil: Sanillan, Juan Manuel. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; ArgentinaFil: Vazquez, Mabel Elena. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales; ArgentinaFil: Botto, Irma Lia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; Argentin
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