890 research outputs found

    Microstructure and Modelling of Shear Forming

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    The advent of multiaxial CNC machines has generated renewed interest in flexible incremental forming manufacturing methodologies, such as shear forming. These processes use rotating tools in constant local contact with the workpiece, which is often also rotating, to generate shape. As a consequence, much lower loads than conventional forming are needed to produce components with no need for expensive special tooling. Potential has already been established by demonstrating manufacture of high-value products, e.g. turbine and satellite parts, with high dimensional accuracy from difficult to manufacture materials. Thus, huge opportunities exist for these processes to replace the current method of manufacture for a range of high value components, e.g. eliminating lengthy machining, reducing material waste and process times; or the manufacture of a complicated shape without the development of expensive tooling. However, little is known about the exact deformation conditions during processing and why certain materials are better than others for shear forming, leading to significant trial and error before production. Three alloys were used for this project: Timetal 54M, Jethete M154 and Inconel 718. General microscopy and Electron Backscatter Diffraction were used to measure strains and orientation maps during shear forming and compared with finite element simulations of the process. It was found that in all cases simple shear deformation was dominate but its extent varied through the thickness, with greater levels of deformation at the roller side. A Design of Experiments analysis was also conducted in order to understand the impact of process parameters in the properties of the final workpieces. Such information was the key to develop a reliable Finite Element Model (FEM) that closely resembles the deformation paths of this process. Three methods of damage calculations were embedded in the finite element model and it was found that the forming limit diagram approach had most potential to identify ultimate failure in shear forming, however its use was still not entirely adequate for this process and a different approach was suggested based on previous works found in the literature. Finally, a methodology to test the potential of materials to be shear spun is proposed based on the finite element model developed and these findings

    Comparative Efficacy of Botulinum Toxin in Salivary Glands vs. Oromotor Therapy in the Management of Sialorrhea in Cerebral Palsy Impact on Sleep Quality

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    AimsThe aim of this study was to compare the effects of intraglandular abobotuliniumtoxinA application and oromotor therapy in the management of sialorrhea in patients with cerebral palsy and its effect on sleep quality.MethodsA comparative study (n = 134), mean age 7.1 years (± 3.9 years) was performed in pediatric patients, between the efficacy of abobotuliniumtoxinA in salivary glands and oromotor therapy (JT), with a control group receiving exclusive oromotor therapy (EOMT). Demographic variables, as well as Gross Motor Function Classification System (GMFCS), Drooling Severity and Frequency Scale (DSFS), Sleep Disturbance Scale for Children (SDSC) and Eating and Drinking Ability Classification System (EDACS) were analyzed in 134 patients considering two measurements 6 months apart. Statistical analysis was developed between both groups.ResultsThe greatest improvement in safety and efficacy of swallowing were those in the JT group with initial levels of EDACS IV and V. Both therapies result in favorable changes of all subscales means of SDSC, with joint therapy showing the greater benefit (p = 0.003) over EOMT (p = 0.06), especially for Sleep Breathing Disorders and Disorders of initiating and maintaining sleep (p < 0.01 vs. p = 0.07). No major adverse effects were found, only those expected from the application of the toxin, such as pain, mild, and transient local inflammation.InterpretationA correlation between frequency and intensity of sialorrhea, with the frequency of sleep disorders and dysphagia was found. Conventional EOMT proved to be useful, improving the safety and efficacy of swallowing, sialorrhea and sleep disorder, however it can be enhanced with the application of abobotuliniumtoxinA

    Application of Raman Spectroscopy for Dental Enamel Surface Characterization

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    Dental enamel is the most complex and highly mineralized human body tissue, containing more than 95% of carbonated hydroxyapatite and less than 1% of organic matter. Current diagnostic methods for enamel caries detection are unable to detect incipient caries lesions. Many papers determine the re-mineralizing effect using many fluorinated compounds and different demineralizing solutions to test physical characterizations such as microhardness, roughness, wettability, among others, but there is not much information about the use of Raman Spectroscopy. Raman Spectroscopy is an efficient technique of chemical characterization to identify functional groups (phosphate-hydroxyl groups) found in the hydroxyapatite formula, which helps identify the level of mineralization on dental enamel surface. Raman spectroscopy is applicable to any state of aggregation of the material, indicated for biological samples. Given the minimum bandwidth of a laser source, as with all spectroscopic techniques that use a laser source, a small sample is sufficient, which makes it an important technique in the analysis of reactive products with very low yield. Raman spectroscopy can be used to obtain the main functional groups in order to determine the remineralization of dental enamel; these results are highly valuable as they can help us make the best decisions on dental treatments

    Overexpression of cathepsin f, matrix metalloproteinases 11 and 12 in cervical cancer

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    BACKGROUND: Cervical carcinoma (CC) is one of the most common cancers among women worldwide and the first cause of death among the Mexican female population. CC progression shows a continuum of neoplastic transitions until invasion. Matrix metalloproteinases (MMPs) and cathepsins play a central role on the enhancement of tumor-induced angiogenesis, cell migration, proliferation, apoptosis and connective tissue degradation. MMPs -2 and -9 expression has been widely studied in cervical cancer. Nevertheless, no other metalloproteinases or cathepsins have been yet related with the progression and/or invasion of this type of cancer. METHODS: Three HPV18 CC cell lines, two HPV16 CC cell lines and three HPV16 tumor CC tissues were compared with three morphologically normal, HPV negative, cervical specimens by cDNA arrays. Overexpression of selected genes was confirmed by end point semiquantitative reverse transcription-PCR with densitometry. In situ hybridization and protein expression of selected genes was further studied by means of two tissue microarrays, one consisting of 10 HSIL and 15 CC and the other one of 15 normal cervical and 10 LSIL tissues. RESULTS: TIMP1, Integrins alpha 1 and 4, cadherin 2 and 11, Cathepsins F, B L2, MMP 9, 10 11 and 12 were upregulated and Cathepsin S, L, H and C, Cadherins 3 and 4, TIMP3, MMP 13, Elastase 2 and Integrin beta 8 were found to be downregulated by cDNA arrays. Endpoint RT-PCR with densitometry gave consistent results with the cDNA array findings for all three genes selected for study (CTSF, MMP11 and MMP12). In situ hybridization of all three genes confirmed overexpression in all the HSIL and CC. Two of the selected proteins were detected in LSIL, HSIL and CC by immunohistochemistry. CONCLUSION: Novel undetected CC promoting genes have been identified. Increased transcription of these genes may result in overexpression of proteins, such as CTSF, MMP11 and MMP12 which could contribute to the pathogenesis of CC

    Heritable Epigenetic Variation among Maize Inbreds

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    Epigenetic variation describes heritable differences that are not attributable to changes in DNA sequence. There is the potential for pure epigenetic variation that occurs in the absence of any genetic change or for more complex situations that involve both genetic and epigenetic differences. Methylation of cytosine residues provides one mechanism for the inheritance of epigenetic information. A genome-wide profiling of DNA methylation in two different genotypes of Zea mays (ssp. mays), an organism with a complex genome of interspersed genes and repetitive elements, allowed the identification and characterization of examples of natural epigenetic variation. The distribution of DNA methylation was profiled using immunoprecipitation of methylated DNA followed by hybridization to a high-density tiling microarray. The comparison of the DNA methylation levels in the two genotypes, B73 and Mo17, allowed for the identification of approximately 700 differentially methylated regions (DMRs). Several of these DMRs occur in genomic regions that are apparently identical by descent in B73 and Mo17 suggesting that they may be examples of pure epigenetic variation. The methylation levels of the DMRs were further studied in a panel of near-isogenic lines to evaluate the stable inheritance of the methylation levels and to assess the contribution of cis- and trans- acting information to natural epigenetic variation. The majority of DMRs that occur in genomic regions without genetic variation are controlled by cis-acting differences and exhibit relatively stable inheritance. This study provides evidence for naturally occurring epigenetic variation in maize, including examples of pure epigenetic variation that is not conditioned by genetic differences. The epigenetic differences are variable within maize populations and exhibit relatively stable trans-generational inheritance. The detected examples of epigenetic variation, including some without tightly linked genetic variation, may contribute to complex trait variation

    Adaptación a los cambios ambientales y territoriales

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    En este libro se abordan temáticas que destacan la adaptación de los distintos sectores de población a los cambios ambientales y territoriales, la cual muestra las respuestas a la incidencia de los estímulos del entorno, económico, social y ambiental. Así, se destaca la exposición de la población a los efectos destructivos de las amenazas y peligros naturales, lo que ha despertado interés en conocer sus causas, prevenir y mitigar el daño. A través de la revisión de estudios se induce la aprehensión de un tema que adquiere importancia en el contexto de los impactos globales, regionales y locales que se producen como consecuencia de la vulnerabilidad estructural característica de los países en desarrollo.En este libro se proponen estrategias de prevención ante la ocurrencia periódica de inundación en San Mateo Atenco, Estado de México y se analizan los factores sociales que inciden en el deterioro del bosque templado en San Lorenzo Huitzitzilapan. También se exponen soluciones para que se mejoren la condición del bosque y la calidad de vida de la población.Proyecto realizado con financiamiento de la Secretaría de Educación Pública-Subsecretaría de Educación Superior-Dirección General de Educación Superior Universitaria. Número del convenio con la SEP: 2017-15-001-017

    The 16th Data Release of the Sloan Digital Sky Surveys : First Release from the APOGEE-2 Southern Survey and Full Release of eBOSS Spectra

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    This paper documents the 16th data release (DR16) from the Sloan Digital Sky Surveys (SDSS), the fourth and penultimate from the fourth phase (SDSS-IV). This is the first release of data from the Southern Hemisphere survey of the Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2); new data from APOGEE-2 North are also included. DR16 is also notable as the final data release for the main cosmological program of the Extended Baryon Oscillation Spectroscopic Survey (eBOSS), and all raw and reduced spectra from that project are released here. DR16 also includes all the data from the Time Domain Spectroscopic Survey and new data from the SPectroscopic IDentification of ERosita Survey programs, both of which were co-observed on eBOSS plates. DR16 has no new data from the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey (or the MaNGA Stellar Library "MaStar"). We also preview future SDSS-V operations (due to start in 2020), and summarize plans for the final SDSS-IV data release (DR17).Peer reviewe

    Bienestar y familia, una mirada desde la psicología positiva

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    Este libro está dirigido a estudiantes y profesionales en psicología y áreas afines, como enfermería, trabajo social o educación, y a los interesados en personalidad positiva. Cada capítulo se presenta de manera sencilla y con una estructura didáctica, pero sin perder rigor científico y calidad de la revisión, con el fin de facilitar el acceso a la información sobre bienestar individual, familiar y social de una forma accesible para adentrarnos al estudio de temas de psicología positiva. Dadas las temáticas, se consideró pertinente dividir este libro en dos secciones: I. Psicología positiva y bienestar. II. Bienestar individual y familiar.Universidad Autónoma del Estado de México y Ediciones y Gráficos Eón, S.A. de C.V

    The Changing Landscape for Stroke\ua0Prevention in AF: Findings From the GLORIA-AF Registry Phase 2

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    Background GLORIA-AF (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients with Atrial Fibrillation) is a prospective, global registry program describing antithrombotic treatment patterns in patients with newly diagnosed nonvalvular atrial fibrillation at risk of stroke. Phase 2 began when dabigatran, the first non\u2013vitamin K antagonist oral anticoagulant (NOAC), became available. Objectives This study sought to describe phase 2 baseline data and compare these with the pre-NOAC era collected during phase 1. Methods During phase 2, 15,641 consenting patients were enrolled (November 2011 to December 2014); 15,092 were eligible. This pre-specified cross-sectional analysis describes eligible patients\u2019 baseline characteristics. Atrial fibrillation disease characteristics, medical outcomes, and concomitant diseases and medications were collected. Data were analyzed using descriptive statistics. Results Of the total patients, 45.5% were female; median age was 71 (interquartile range: 64, 78) years. Patients were from Europe (47.1%), North America (22.5%), Asia (20.3%), Latin America (6.0%), and the Middle East/Africa (4.0%). Most had high stroke risk (CHA2DS2-VASc [Congestive heart failure, Hypertension, Age  6575 years, Diabetes mellitus, previous Stroke, Vascular disease, Age 65 to 74 years, Sex category] score  652; 86.1%); 13.9% had moderate risk (CHA2DS2-VASc = 1). Overall, 79.9% received oral anticoagulants, of whom 47.6% received NOAC and 32.3% vitamin K antagonists (VKA); 12.1% received antiplatelet agents; 7.8% received no antithrombotic treatment. For comparison, the proportion of phase 1 patients (of N = 1,063 all eligible) prescribed VKA was 32.8%, acetylsalicylic acid 41.7%, and no therapy 20.2%. In Europe in phase 2, treatment with NOAC was more common than VKA (52.3% and 37.8%, respectively); 6.0% of patients received antiplatelet treatment; and 3.8% received no antithrombotic treatment. In North America, 52.1%, 26.2%, and 14.0% of patients received NOAC, VKA, and antiplatelet drugs, respectively; 7.5% received no antithrombotic treatment. NOAC use was less common in Asia (27.7%), where 27.5% of patients received VKA, 25.0% antiplatelet drugs, and 19.8% no antithrombotic treatment. Conclusions The baseline data from GLORIA-AF phase 2 demonstrate that in newly diagnosed nonvalvular atrial fibrillation patients, NOAC have been highly adopted into practice, becoming more frequently prescribed than VKA in Europe and North America. Worldwide, however, a large proportion of patients remain undertreated, particularly in Asia and North America. (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients With Atrial Fibrillation [GLORIA-AF]; NCT01468701
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