Combined Manufacturing Process of Copper Electrodes for Micro Texturing Applications (AMSME).

Surface texturing has brought significant improvements in the functional properties of parts and components. Sinker electro discharge machining (SEDM) is one of the processes which generates great texturing results at different scale. An electrode is needed to reproduce the geometry to be textured. Some geometries are difficult or impossible to achieve on an electrode using conventional and even unconventional machining methods. This work sets out the advances made in the manufacturing of copper electrodes for electro erosion by additive manufacturing, and their subsequent application to the functional texturing of Al-Cu UNS A92024-T3 alloy. A combined procedure of digital light processing (DLP) additive manufacturing, sputtering and micro-electroforming (AMSME), has been used to produce electrodes. Also, a specific laboratory equipment has been developed to reproduce details on a microscopic scale. Shells with outgoing spherical geometries pattern have been manufactured. AMSME process has shown ability to copper electrodes manufacturing. A highly detailed surface on a micrometric scale have been achieved. Copper shells with minimum thickness close to 300 µm have been tested in sinker electro discharge machining (SEDM) and have been shown very good performance in surface finishing operations. The method has shown great potential for use in surfaces texturing.

On the Machinability of an Al-63%SiC Metal Matrix Composite.

This paper presents a preliminary study of aluminium matrix composite materials during machining, with a special focus on their behavior under conventional processes. This work will expand the knowledge of these materials, which is considered to be strategic for some industrial sectors, such as the aeronautics, electronics, and automotive sectors. Finding a machining model will allow us to define the necessary parameters when applying the materials to industry. As a previous step of the material and its machining, an experimental state-of-the-art review has been carried out, revealing a lack of studies about the composition and material properties, processes, tools, and recommended parameters. The results obtained and reflected in this paper are as follows; SiC is present in metallic matrix composite (MMC) materials in a very wide variety of sizes. A metallographic study of the material confirms the high percentage of reinforcement and very high microhardness values registered. During the machining process, tools present a very high level of wear in a very short amount of time, where chips are generated and arcs are segmented, revealing the high microhardness of the material, which is given by its high concentration of SiC. The chip shape is the same among other materials with a similar microhardness, such as Ti or its alloys. The forces registered in the machining process are quite different from conventional alloys and are more similar to the values of harder alloys, which is also the case for chip generation. The results coincide, in part, with previous studies and also give new insight into the behavior of this material, which does not conform to the assumptions for standard metallic materials, where the hypothesis of Shaffer is not directly applicable. On the other hand, here, cutting forces do not behave in accordance with the traditional model. This paper will contribute to improve the knowledge of the Al-63%SiC MMC itself and the machining behavior.

Kerf Taper Defect Minimization Based on Abrasive Waterjet Machining of Low Thickness Thermoplastic Carbon Fiber Composites C/TPU.

Carbon fiber-reinforced thermoplastics (CFRTPs) are materials of great interest in industry. Like thermosets composite materials, they have an excellent weight/mechanical properties ratio and a high degree of automation in their manufacture and recyclability. However, these materials present difficulties in their machining due to their nature. Their anisotropy, together with their low glass transition temperature, can produce important defects in their machining. A process able to machine these materials correctly by producing very small thermal defects is abrasive waterjet machining. However, the dispersion of the waterjet produces a reduction in kinetic energy, which decreases its cutting capacity. This results in an inherent defect called a kerf taper. Also, machining these materials with reduced thicknesses can increase this defect due to the formation of a damage zone at the beginning of cut due to the abrasive particles. This paper studies the influence of cutting parameters on the kerf taper generated during waterjet machining of a thin-walled thermoplastic composite material (carbon/polyurethane, C/TPU). This influence was studied by means of an ANOVA statistical analysis, and a mathematical model was obtained by means of a response surface methodology (RSM). Kerf taper defect was evaluated using a new image processing methodology, where the initial and final damage zone was separated from the kerf taper defect. Finally, a combination of a hydraulic pressure of 3400 bar with a feed rate of 100 mm/min and an abrasive mass flow of 170 g/min produces the minimum kerf taper angle.

Influence of PLA Filament Conditions on Characteristics of FDM Parts.

Additive manufacturing technologies play an important role in Industry 4.0. One of the most prevalent processes is fused deposition modelling (FDM) due to its versatility and low cost. However, there is still a lack of standardization of materials and procedures within this technology. This work aims to study the relationship of certain operating parameters and the conditions of poly(lactic acid) (PLA) polymer with the results of the manufactured parts in dimensional terms, surface quality, and mechanical strength. In this way, the impact of some material characteristics is analyzed, such as the pigmentation of the material and the environmental humidity where it has been stored. The manufacturing parameter that relates to these properties has been the extrusion temperature since it is the most influential in this technology. The results are quite affected especially by humidity, being a parameter little studied in the literature.

Tool Wear Mechanism in Cutting of Stack CFRP/UNS A97075.

The aeronautics industry's competitiveness has led to the need to increase productivity with one shot drilling (OSD) systems capable of drilling stacks of dissimilar materials (fibre/metal laminates, FML) in order to reduce riveting times. Among the materials that constitute the current aeronautical models, composite materials and aluminium (Al) and titanium (Ti) alloys stand out. These one-pass machining techniques produce high-quality holes, especially when all the elements that have to be joined are made of the same material. This work has followed a conventional OSD strategy and the same cutting conditions applied to CFRP (carbo-fibre-reinforced polymer), Al and CFRP/Al stacked sheets to know the wear mechanisms produced. With this purpose, results were obtained by using current specific techniques, such as microstructural analysis, monitoring of the shear forces and analysis of macrogeometric deviations. It has been determined that when these drilling techniques are applied under the same cutting conditions to stacks of materials of a different nature, the results of the wear mechanisms acting on the tool differ from those obtained when machining each material separately. This article presents a comparison between the effects of tool wear during dry drilling of CFRP and UNS A97075 plates separately and when machined as stacks.

Three-dimensional chemical mapping using non-destructive SEM and photogrammetry.

The slice and view approach in electron microscopy defines an ensemble of destructive techniques that is widely used for studying in 3D the structure and chemistry of samples with dimensions ranging from µm to mm. Here, a method is presented for measuring with high resolution and quantitatively the morphology and chemical composition of the surface of a sample in 3D. It is non-destructive and therefore, it is complementary to slice and view methods. The scheme is based on the fusion of conventional scanning electron microscopy (SEM) imaging, multi-view photogrammetry and compositional mapping using energy dispersive X-ray spectroscopy (EDXS). We demonstrate its potential by performing an accurate study of adhesion wear of a tungsten carbide tool that is difficult to obtain using conventional characterization techniques.

Application of Pin-On-Disc Techniques for the Study of Tribological Interferences in the Dry Machining of A92024-T3 (Al⁻Cu) Alloys.

One of the main criteria for the establishment of the performance of a forming process by material removal is based on cutting tool wear. Wear is usually caused by different mechanisms, however, only one is usually considered as predominant or the controller of the process. This experimental research is focused on the application of Pin-on-Disc wear tests, in which the tribological interference between UNS A92024-T3 Aluminum⁻Copper alloy and tungsten carbide (WC⁻Co) has been studied. The main objective of this study is focused on the determination of the predominant wear mechanisms involved in the process, as well as the characterization of the sliding and friction effects by using SEM and Energy Dispersion Spectroscopy (EDS) techniques, as applied to WC⁻Co (cutting tool material)/Al (workpiece material) which are widely used in the aerospace industry. Performed analysis prove the appearance of abrasive wear mechanisms prior to adhesion. This fact promotes adhesion mechanisms in several stages because of the surface quality deterioration, presenting different alloy composition in the form of a Built-Up Layer (BUL)/Built-Up Edge (BUE).

Novel Analysis Software for Detecting and Classifying Ca2+ Transient Abnormalities in Stem Cell-Derived Cardiomyocytes.

Comprehensive functioning of Ca2+ cycling is crucial for excitation-contraction coupling of cardiomyocytes (CMs). Abnormal Ca2+ cycling is linked to arrhythmogenesis, which is associated with cardiac disorders and heart failure. Accordingly, we have generated spontaneously beating CMs from induced pluripotent stem cells (iPSC) derived from patients with catecholaminergic polymorphic ventricular tachycardia (CPVT), which is an inherited and severe cardiac disease. Ca2+ cycling studies have revealed substantial abnormalities in these CMs. Ca2+ transient analysis performed manually lacks accepted analysis criteria, and has both low throughput and high variability. To overcome these issues, we have developed a software tool, AnomalyExplorer based on interactive visualization, to assist in the classification of Ca2+ transient patterns detected in CMs. Here, we demonstrate the usability and capability of the software, and we also compare the analysis efficiency to manual analysis. We show that AnomalyExplorer is suitable for detecting normal and abnormal Ca2+ transients; furthermore, this method provides more defined and consistent information regarding the Ca2+ abnormality patterns and cell line specific differences when compared to manual analysis. This tool will facilitate and speed up the analysis of CM Ca2+ transients, making it both more accurate and user-independent. AnomalyExplorer can be exploited in Ca2+ cycling analysis to study basic disease pathology and the effects of different drugs.

On computation of calcium cycling anomalies in cardiomyocytes data.

Induced pluripotent stem cell (iPSC) lines derived from skin fibroblasts of patients suffering from cardiac disorders were differentiated to cardiomyocytes and used to generate a data set of Ca(2+) transients of 136 recordings. The objective was to separate normal signals for later medical research from abnormal signals. We constructed a signal analysis procedure to detect peaks representing calcium cycling in signals and another procedure to classify them into either normal or abnormal peaks. Using machine learning methods we classified signals into normal or abnormal signals on the basis of peak findings in them. We compared classification results obtained to those made visually by an expert biotechnologist who assessed the signals independent of the computer method. Classification accuracies of around 85% indicated high congruence between two modes denoting the high capability and usefulness of computer based processing for the present data.

[Thoracic actinomycosis in the differential diagnosis of neoplasm: a propos of a case]. / Actinomicosis torácica como diagnóstico diferencial de neoplasia: a propósito de un caso.

Actinomycosis is an infrequent infection caused by bacteria from Actinomyces genus that manifests as a chronic, suppurative and progressive disease. It's more common in men. Thoracic actinomycosis occurs in 15% of the cases, and infection of the chest wall is less frequent. The clinical presentation mimics tuberculosis or neoplastic processes. In this article we present the case of a 63 year-old man with no comorbidity, with pulmonary actinomycosis involving the chest wall mimicking a neoplastic process, basing the diagnosis on histopathologic findings.

Actinomicosis torácica como diagnóstico diferencial de neoplasia: a propósito de un caso / Thoracic actinomycosis in the differential diagnosis of neoplasm: a propos of a case

Actinomycosis is an infrequent infection caused by bacteria from Actinomyces genus that manifests as a chronic, suppurative and progressive disease. It's more common in men. Thoracic actinomycosis occurs in 15% of the cases, and infection of the chest wall is less frequent. The clinical presentation mimics tuberculosis or neoplastic processes. In this article we present the case of a 63 year-old man with no comorbidity, with pulmonary actinomycosis involving the chest wall mimicking a neoplastic process, basing the diagnosis on histopathologic findings.

La actinomicosis es una infección poco común causada por bacterias del género Actinomyces que se manifiesta como una enfermedad crónica, supurativa y progresiva. Es más frecuente en hombres. La actinomicosis torácica se presenta en 15% de los casos, siendo el compromiso de pared torácica aún menos frecuente. La presentación clínica simula procesos neoplásicos o tuberculosis. Se describe el caso de un hombre de 63 años, sin co-morbilidad, con una actinomicosis pulmonar con compromiso de pared torácica que simuló ser un proceso neoplásico. El diagnóstico fue confirmado por los hallazgos histopatológicos.

Organizing pneumonia in patients with severe respiratory failure due to novel A (H1N1) influenza.

The authors describe two cases that developed organizing pneumonia (OP) associated with novel influenza A(H1N1) virus. These patients were admitted to intensive care unit (ICU) because of severe respiratory failure. After initial clinical improvement, both patients worsened their condition during their second week of ICU stay, presenting fever, increasing in inflammatory parameters and worsening in oxygen exchange and respiratory mechanics. Chest x-rays and computed tomographies showed an increment on lung infiltrates, given by areas of consolidation and ground glass opacification. Although broad-spectrum antibiotics were administered, patients showed no improvement. All cultures, including bronchoalveolar lavage samples, were negative. In both cases, an open lung biopsy was performed, and histopathological examination of the specimen was compatible with OP. Both patients were successfully treated with high-dose corticoids. The aim of this report is to alert about the possibility of OP associated with novel influenza virus in patients with severe respiratory failure.

[Sclerosing hemangioma presenting as a solitary lung nodule. Report of one case]. / Hemangioma esclerosante pulmonar como nódulo pulmonar solitario: comunicación de un caso.

Lung sclerosing hemangioma is an uncommon tumor that presents as a solitary asymptomatic nodule and that affects middle age women. It derives from type II pneumocytes. We report a 52 years old female with a solitary lung nodule detected in a chest X ray requested for the diagnosis of an acute respiratory disease. The nodule was excised by video thoracoscopy and the frozen section biopsy was informed as a non small cell undifferentiated carcinoma. Therefore an inferior right lobectomy with lymph node resection was performed. The definitive biopsy was informed as a lung sclerosing hemangioma.

Hamartoma endobronquial: a propósito de un caso / Endobronchial hamartoma: case report

El hamartoma es el tumor pulmonar benigno más frecuente. En su mayoría se encuentran en el parénquima pulmonar, pero en algunos casos se presentan en bronquios. Los hamartomas endobronquiales pueden ser hallazgos radiológicos, aunque en ocasiones pueden producir tos crónica o neumonías a repetición. El manejo es la resección endoscópica, pero debido al difícil diagnóstico diferencial con las neoplasias malignas pulmonares, la resección pulmonar juega un papel importante. Se presenta el caso de una paciente de 72 años con un cuadro de tos crónica. Se pesquisó en estudio radiológico una masa en lóbulo superior derecho con compromiso bronquial. La fibrobroncoscopía con biopsia y citología no pudo determinar diagnóstico. Se realizó lobectomía superior derecha. El estudio histológico intraoperatorio y diferido confirmaron el diagnóstico de hamartoma.

Tratamiento médico de perforación esofágica secundaria a cuerpo extraño / Medical treatment of esophageal perforation secondary to foreign body

Se reporta el caso de un paciente con perforación esofágica producida por un fragmento de hueso de pavo asociada a una colección mediastínica. El tratamiento conservador, con atibióticos y alimentación parenteral exclusiva fue exitoso. Aunque el tratamiento de esta complicación es discutible nos parece esencial elegir estrategias que mejor se adapten al cuadro clínico y al paciente de manera específica.

Isquemia mesentérica aguda: experiencia de 10 años / Acute mesenteric ischemia: 10 years experience

La isquemia mesentérica aguda (IMA) es una emergencia vascular poco frecuente, alrededor de 1 a 4 casos por 1000 operaciones abdominales de urgencia o 9 por cada 1000 admisiones hospitalarias. El síndrome de isquemia mesentérica representa la causa más frecuente de isquemia intestinal e incluye procesos de embolía, trombosis del eje arterial mesentérico superior, trombosis del eje venoso mesentérico superior e isquemia mesentérica no oclusiva (IMNO). La primera aproximación en el diagnóstico y tratamiento, en la mayoría de nuestros hospitales, es realizada por el cirujano general del servicio de emergencia. Constituida la necrosis intestinal, las manifestaciones clínicas de abdomen agudo y el compromiso hemodinámico y séptico que acompañan al infarto visceral, son señales inequívocas de un proceso muy avanzado y que probablemente termine con la vida del paciente. El diagnóstico etiológico preciso varía según los métodos de estudio disponibles (TAC abdomen, ecografía dupplex, angiografía). La angiografía es el método diagnóstico de elección, pero el TAC y ECO DUPLEX también son métodos diagnósticos importantes en trombosis venosa mesentérica, a veces con mejor rendimiento

Neuritis óptica y embarazo / Optical Neuritis and pregnancy

Paciente femenina, 29 años, con pérdida visual parcial y progresiva unilateral ojo izquierdo, inicio súbito, cursando embarazo de 32 semanas. El examen oftalmológico detecta: cuenta dedos a 1 metro en O.I. pupila hiporeactiva, edema de papila y componente vascular a la fundoscopía. El examen neurológico fue normal a excepción de su déficit visual monoocular izquierdo. Campimetría: presencia de escotoma central y escotoma relativo nasal superior e inferior, con recuperación total de la agudeza visual en O.I. a las 4 semanas luego de recibir corticoterapia. La TAC y las pruebas inmunológicas fueron normales. La neuritis óptica se presenta en pacientes jóvenes en forma de déficit visual monoocular progresivo, puede acompañarse de dolor en región orbitaria...

Neuropatía óptica traumática. Violencia social / Traumatic optic neuropathy. Social violence

Paciente masculino, 41 años, presenta pérdida visual total en ojo izquierdo, ptosis palpebral e hiporreactividad pupilar izquierda secundaria a impacto de bala en región frontal derecha, localizándose a la fecha en región parietal izquierda luego de trayecto oblicuo, lesionando estructuras ópticas del mismo lado. Trauma craneoencefálico que revela espina irritativa residual por presencia de proyectil. El examen oftalmológico confirmó compromiso total del II par izquierdo, con la consiguiente ceguera y reflejo de marcus gunn incipiente; además afectación parcial del III par izquierdo (ptosis palpebral y trastornos de la reactividad pupilar). En el examen neurológico destaca el buen nivel de conciencia sin signos de focalización a pesar de haber permanecido en coma los 15 días iniciales posteriores al trauma.La fundoscopía destaca palidez del nervio óptico izquierdo. Un tac post-trauma demostró gran edema cerebral, contusión hemorrágica intraparenquimatosa, fronto parieto occipital izquierda. La atrofia óptica post traumática simple resulta como su nombre lo indica de heridas del nervio óptico, fracturas del canal orbitario o por heridas de proyectil. La atrofia no se presenta inmediatamente sino después de varias semanas, aunque la reducción de la visión y hasta la ceguera se producen inmediatamente, como en el caso nuestro.

This is the case of a 41 years old male patient with loss of vision in his left eye, palpebral ptosis, left pupil hyporreactivity, secondary to a bullet impact in the right fore head region; actually this is localized in left parietal region, hurting optical structures of this side.Ophtalmological evaluation reveal total compromise of II left nerve with blindness and incipient marcus gunn reflex. Also we found partial affectation of III left nerve.Neurological evaluation showed a good level of conscience without any complication.Fundoscopy showed optical nerve paleness. CAT scan showed cerebral edema, hemorrhagical contusion.

Cancer pulmonar / Lung cancer

El cáncer pulmonar constituye un problema importante de salud. Su frecuencia ha aumentado significativamente en las últimas décadas. La tasa de mortalidad es elevada, tanto en hombres como mujeres y se duplica cada 15 años. En este artículo se revisan aspectos epidemiológicos de este carcinoma y se exponen sus diferentes tipos histológicos. Se menciona las manifestaciones clínicas y el estudio diagnóstico de la enfermedad. Se hace referencia a las clasificaciones y al tratamiento en los distintos estadios de esta neoplasia