Aplicación del método de elementos finitos en la obtención de la velocidad de avance de fisura por fatiga en modelos de acumulación de daño

Se presenta la evaluación de tres modelos de propagación de fisuras por fatiga, que incorporan la noción de daño, mediante el método de los elementos finitos. Se evalúan los modelos de Antolovich, Duggan y Font Filax utilizando un programa de elementos finitos tridimensionales elastoplásticos y un espécimen de tensión compacta CT de acero inoxidable AISI 316 de distintos espesores. En los tres modelos se determina la velocidad de avance de fisura utilizando los valores dados por el programa de elementos finitos. En el modelo de acumulación de daño de Font Filax se determina, en forma numérica. la distribución de deformaciones plásticas cíclicas que se generan delante de una fisura en fatiga, la cual es utilizada en la estimación de la velocidad de propagación. En las versiones de Antolovich y Duggan, los parámetros que estos modelos utilizan se determinan de la distribución de deformaciones que entrega el programa de elementos finitos. Se estudian Las zonas de no propagación y de propagación estable de fisura, para lo cual las probetas fueron solicitadas hasta un valor del rango de intensidad de tensiones de 40 M PaY m, en algunos de sus espesores. y hasta 80 MPaYm en el espesor de 50 mm. En general, el modelo de Antolovich sobreestima la velocidad defisuración, en tanto que el modelo de Duggan la sobreestima en exceso o la subestima según sea la versión que se tome. Por el contrario, el modelo de Font Filax predice bien los valores experimentales al existir un buen acuerdo con Los valores numéricos obtenidos

Presentación de modelos de propagación de fisuras por acumulación de daño por fatiga

Se presenta un estudio de diferentes modelos de propagación de fisuras por fatiga que utilizan el concepto de daño . En particular se presentan y desarrollan tres modelos específicos. El modelo de Antolovich, el modelo de Duggan y el modelo de acumulación de daño plástico de Font Filax. Se hace hincapié en la fundamentación física de éstos, y en los parámetros que los gobiernan, así como en su rango de aplicabilidad

Factors associated with extended remission in neovascular age-related macular degeneration on pro re nata treatment protocol.

AimTo show the characteristics and outcomes of patients with neovascular age-related macular degeneration (nAMD) who had extended remission (ER) while on a pro re nata (PRN) treatment protocol.MethodsThis was a retrospective case-control study of a consecutive series of patients with nAMD treated with a PRN antivascular endothelial growth factor (anti-VEGF) drug regimen. ER was defined as the absence of haemorrhage, intraretinal/subretinal fluid on optical coherence tomography and leakage on fluorescein angiography for 52 weeks after cessation of anti-VEGF therapy. Matching patients with nAMD who did not achieve ER were included as control group. Cox regression analysis was fitted to identify predictors of time to achieve ER and time to recurrence. A logistic regression analysis of baseline characteristics was used to identify predictors of achieving ER.ResultsOf 830 eyes treated with anti-VEGF monotherapy, 77 (9.2%) eyes achieved ER during a median follow-up of 236 weeks (range 70-525 weeks). Cox regression analysis showed that ER was achieved earlier in eyes with isolated intraretinal fluid (HR, 2.05; 95% CI 1.929 to 4.520; p=0.045) at presentation. Logistic regression analysis showed that type 3 choroidal neovascularisation (OR, 0.090; 95% CI 0.021 to 0.382; p=0.001), thinner choroid (OR, 0.993; 95% CI 0.988 to 0.998; p=0.004) and absence of macular atrophy (OR, 0.233; 95% CI 0.065 to 0.839; p=0.026) at baseline increased the likelihood of achieving ER.ConclusionER is achievable in 9.2% of patients under PRN therapy for nAMD. At presentation with nAMD, anatomical features on retinal imaging may predict the likelihood of achieving ER and a shorter time to achieve ER

Capillary Dynamics of Water/Ethanol Mixtures

Surface tension and contact angle play important roles in capillary dynamics during washing commission of spray-dried detergent powder where interaction between surface chemistry and liquid is concerned. An experimental study for the dynamics of water/ethanol mixtures in both hydrophilic and hydrophobic capillary tubes has been investigated. The combination of water/ethanol mixtures and trimethylchlorosilane coating on capillaries provides a variety of liquid surface tension and contact angle for the penetrating system. Significant differences of penetrating speed on hydrophilic and hydrophobic tubes indicate that dynamic contact angle dominates the hydrophobic surface while liquid surface tension plays a more important role on the hydrophilic surface. The speed gradient of different liquids on hydrophilic surface is greater than the hydrophobic surface, mainly due to the domination between hydrogen bonding structures and water polarity while liquid moves on surfaces covered with different chemistry, physically absorbed water on silica capillaries or silanol group covered capillaries

The neglect of herself in the process of Infatuation–Love

La presente investigación, de corte cualitativo, tiene como objetivo describir la forma como se vive el proceso de Enamoramiento-Amor en una población de mujeres universitarias del Estado de México. Se desarrolló en dos momentos, primero mediante la técnica de Redes Semánticas se indagó sobre lo que conciben como amor, enamoramiento y manifestaciones de éstos. A partir de estos resultados, se eligió a las informantes clave; a quienes en un segundo momento se aplicó una entrevista semiestructurada, que profundiza en los conocimientos, comportamiento y el tipo de emociones que se viven en el proceso de Enamoramiento-Amor. Los hallazgos muestran que las mujeres universitarias en el proceso de Enamoramiento parten de la idealización del otro, no perciben sus defectos o bien se toleran; el comportamiento que se asume se encuentra ligado al deber ser del amor, donde todo es justificado y perdonado en nombre de este sentimiento. En la etapa de amor, se presentan conductas de protección y cuidado hacia el otro, dejando en último las propias necesidades. Las informantes señalan que en el amor se generan sentimientos ambivalentes de extrema felicidad y sufrimiento al tener que tolerar violencia física y psicológica por parte de la pareja, esto coincide con la concepción de Fromm acerca del amor como fundamental en el ser humano, donde se debe aprender y ejercitar poniendo en juego toda la personalidad, implica asumir una actitud positiva, una orientación de carácter, un acto de voluntad y compromiso hacía el otro; aunque en este caso no sea recíproco

UK end-of-life care services in dementia, initiatives and sustainability: results of a national online survey

BACKGROUND: People living and dying with non-cancer diagnoses, including dementia, have poorer access to generalist and specialist palliative care than people with cancer, and experience worse outcomes in terms of pain and symptom control, and quality and experience of care. In the UK, the National Council for Palliative Care (NCPC) ran a national survey of services for end-of-life care for people with dementia (2008) in which 16 services were identified, and reported on case studies and examples of good practice. We updated the NCPC survey to review progress in previously identified services, identify factors that lead to sustainable services and identify new initiatives in this area of care. METHODS: An online survey was developed and piloted before use. Initiatives were contacted via targeted (N=63) and open call invitations. The survey was made up of 5 sections. Quantitative data were analysed using descriptive statistics. RESULTS: 15 services responded. They engaged in a wide range of activities predominately providing direct care (80%) and workforce development/advisory or educational activities (87%). Results suggest that sustainability of services is reliant on clinicians with a leadership role and wider system support through funding mechanisms and a minimum level of integration within normal service provision. CONCLUSIONS: Recent initiatives are largely built on the expertise of the nursing profession (with or without input from medical consultants), and driven mainly by the charity and hospice sector. This has generated a potential new model of care provision in end of life dementia care, 'Hospice-enabled Dementia Care'

ESBL and AmpC β-Lactamases in Clinical Strains of Escherichia coli from Serra da Estrela, Portugal

Background and Objectives: Given the considerable spatial, temporal, and ecological factors, heterogeneity, which affects emergency response, persistence, and dissemination of genetic determinants that confer microorganisms their resistance to antibiotics, several authors claim that antibiotics' resistance must be perceived as an ecological problem. The aim of this study was to determine the prevalence of broad-spectrum bla genes, not only Extended-spectrum β-lactamases (ESBL) but also AmpC-types, in clinical strains of Escherichia coli isolated from Portugal (in the highest region of the country, Serra da Estrela) to disclose susceptibility profiles among different genotypes, and to compare the distribution of bla genes expressing broad-spectrum enzymes. Materials and Methods: Clinical strains of Escherichia coli presenting resistance to third generation (3G) cephalosporins and susceptibility to inhibition by clavulanic acid were studied by means of phenotypic and molecular profiling techniques for encoding β-lactamases genes. Results: Strains were mainly isolated from hospital populations (97%). Molecular analysis enabled the detection of 49 bla genes, in which 55% (27/49) were identified as blaOXA-1-like, 33% (16/49) as blaCTX-M-group-1, 10% (5/49) as blaTEM, and 2% (1/49) were identified as genes blaCIT (AmpC). Among all blaOXA-1-like detected, about 59% of strains expressed at least another bla gene. Co-production of β-lactamases was observed in 40% of strains, with the co-production of CTX-M group 1 and OXA-1-like occurring as the most frequent. Conclusions: This is the first study using microorganisms isolated from native people from the highest Portuguese mountain regions, showing an unprecedent high prevalence of genes blaOXA-1-like in this country.NORTE-01-0145-FEDER-000012; SAICT-POL/24325/2016.info:eu-repo/semantics/publishedVersio