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A customized digital image correlation (DIC) system was implemented to monitor the strain produced in a cold-rolled AL-6XN stainless steel plate, 3.0 mm thick, subjected to quasi-static and cyclic loading tests. A comparison of the DIC strain measurements was made against those provided by conventional extensometers. Furthermore, the DIC system was used to monitor the fatigue crack initiation in low-cycle fatigue tests. The true stress-strain behavior for the AL-6XN material was properly captured by the DIC measurements. For low-cycle fatigue tests (strain control), the strain mapping generated by DIC allowed for identifying zones with higher strain than the nominal strain amplitude applied (εa) since the first stages of the fatigue life (FL). These zones become potential fatigue crack initiation sites.

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BACKGROUND: Gliomas account for 30% of primary brain tumors in adults, and despite the scientific progress in the field, recurrence is prevalent. Glioma Stem Cells (GSCs) can generate tumor cells in vivo and in vitro and they are associated with treatment resistance, tumor progression, and recurrence. Furthermore, the expression of SOX transcription factors (SOX1, SOX2, SOX9) in these cells is responsible for maintaining an oncogenic genotype and is associated with an aggressive tumor phenotype. The relationship between SOX transcription factors and their prognostic role in recurrent gliomas has not been described in detail. Therefore, we set out to describe the relationship between SOX expression and Progression-free Survival (PFS) and Overall Survival (OS) in patients with recurrent gliomas. METHODS: In this observational study, we have retrospectively analyzed 69 patients, of which 20 met the inclusion criteria. The clinical, radiological, and histopathological findings have been described, and survival analysis has been performed according to SOX expression for PFS and OS. RESULTS: We found SOX1, SOX2, and SOX9 to show a non-statistically significant trend with increasing histopathological grade, co-expressed with Ki67, a cell proliferation factor. CONCLUSION: There has been found an inversely proportional correlation between the degree of immunopositivity of SOX1 and OS. A higher SOX1 immunopositivity could predict a worse clinical prognosis. There has also been found an interaction between a pluripotent genotype (GSC) and cell proliferation.

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We investigated the interfacial electronic structure of the bidimensional interface of single-layer graphene on a germanium substrate. The procedure followed a well-established approach using ultraviolet (UPS) and X-ray (XPS) photoelectron spectroscopy. The direct synthesis of the single-layer graphene on the surface of (110) undoped Ge substrates was conducted via chemical vapor deposition (CVD). The main graphitic properties of the systems were identified, and it was shown that the Ge substrate affected the electronic structure of the single-layer graphene, indicating the electronic coupling between the graphene and the Ge substrate. Furthermore, the relevant features associated with the Schottky contact's nature, the energy level's alignments, and the energy barrier's heights for electron and hole injection were obtained in this work. The results are useful, given the possible integration of single-layer graphene on a Ge substrate with the complementary metal-oxide-semiconductor (CMOS) technology.

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1,4-naftoquinone (NQ) molecules have been extensively evaluated as potent antibacterial compounds; however, their use is limited, since they have low water solubility and exhibit toxicities in healthy eukaryotic cells. A possible path to overcoming these challenges is the use of particulate vehicles, such as SBA-15, which is a biocompatible and biodegradable mesoporous silica material, that may enhance drug delivery and decrease dosages. In this work, an isotherm model-based adsorption of three NQs into SBA-15 microparticles was evaluated. Interactions between NQs and SBA-15 microparticles were modeled at the B3LYP/6-31+G(d,p) level of theory to understand the nature of such interactions. The results demonstrated that the adsorption of NQ, 2NQ, and 5NQ into SBA-15 fit the Freundlich adsorption model. According to theorical studies, physisorption is mediated by hydrogen bonds, while the most stable interactions occur between the carbonyl group of NQ and silica surfaces. Both experimental and theoretical results contribute to a deeper understanding of the use of SBA-15 or similar particles as nanovehicles in such a way that NQs can be modified in carbonyl or C3 to enhance adsorptions. The theoretical and experimental results were in accordance and contribute to a deeper understanding of how interactions between NQ-type molecules and SiO2 materials occur.

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Organic/inorganic van der Waals heterojunctions formed by a combination of 2D materials with semiconductor polymer films enable the fabrication of new device architectures that are interesting for electronic and optoelectronic applications. Here, we investigated the charge-transfer dynamics at the interface between 2D layered franckeite (Fr) and two thiophene-based conjugated polymers (PFO-DBT and P3HT) from the resonantly core-excited electron. The unoccupied electronic states of PFO-DBT/Fr and P3HT/Fr heterojunctions were studied using near-edge X-ray absorption fine structure (NEXAFS) and resonant Auger (RAS) synchrotron-based spectroscopies. We found evidence of ultrafast (subfemtosecond charge-transfer times) interfacial electron delocalization pathways from specific electronic states. For the interface between the PFO-DBT polymer and exfoliated franckeite, the most efficient interfacial electron delocalization pathways were found through π*(S-N) and π*(S-C) electronic states corresponding to the benzothiadiazole and thiophene units. On the other hand, for the P3HT polymer, we found that electrons excited to π-π* and S1s-π*(C-C) electronic states of the P3HT polymer are the most affected by the presence of exfoliated franckeite and consequently are the main interfacial electron-transfer pathways in this heterojunction. Our results have important implications in understanding how ultrafast electron delocalization is taking place in organic/inorganic van der Waals heterojunctions, which is relevant information in designing new devices involving these systems.

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OBJECTIVE: To compare the measurement of the meibomian gland (MG) dropout between two infrared meibographers in patients with and without dry eye. METHODS: The right eyelids of each patient were imaged using the Antares and Cobra meibography devices. All images were analyzed using Phoenix software to calculate the percentage of the MG dropout. Lipid layer thickness, eyelid margin characteristics, ocular surface staining, MG secretion, number of expressible glands, and noninvasive tear breakup time were also evaluated. A comparison between nondry eye and evaporative dry eye was performed. RESULTS: Eighty participants (mean age, 36.93 years and 51.3% women) were included, of which 67.5% had nondry eye. A significant difference was observed in the dropout percentage of the superior eyelid between the Antares and Cobra devices (P=0.007) for all participants and when only the nondry eye patients were examined. In patients with dry eye, no significant differences were found in the dropout measurements of both eyelids. CONCLUSIONS: Statistically significant differences in the MG dropout percentage in the upper eyelid of nondry eye patients were obtained from both meibographers. The measurements were similar in patients with dry eye, suggesting that the two instruments can be interchanged.

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Spontaneous coronary artery dissection (SCAD) is characterized by tear of the inner layer in the coronary artery, creating a false lumen between the inner and central layer. Its infrequent incidence often leads to delay in diagnosis posing challenges in management. There are currently no guidelines for the treatment of this condition. We describe an adult patient who presented with multiple episodes of ventricular fibrillation, in whom cardiac catheterization showed SCAD, treated by off-pump coronary artery bypass.

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Abstract Spontaneous coronary artery dissection (SCAD) is characterized by tear of the inner layer in the coronary artery, creating a false lumen between the inner and central layer. Its infrequent incidence often leads to delay in diagnosis posing challenges in management. There are currently no guidelines for the treatment of this condition. We describe an adult patient who presented with multiple episodes of ventricular fibrillation, in whom cardiac catheterization showed SCAD, treated by off-pump coronary artery bypass.

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Hybrid van der Waals heterojunctions based on organic polymers and 2D materials have emerged as a promising solution for developing more efficient optoelectronic devices. Herein, we investigated the charge transfer (CT) dynamics at the interface of the poly[3-hexylthiophene-2,5-diyl] (P3HT) organic polymer and a MoS2 monolayer. A global picture of the charge transfer dynamics of a P3HT/MoS2/SiO2 heterojunction was elucidated from photoluminescence (PL) spectroscopy and the fluorescence lifetime decay profile. Rapid interfacial charge transfer between P3HT and MoS2 was indicated by strong PL quenching and a reduction in the average fluorescence lifetime (τav) of the P3HT/MoS2/SiO2 heterojunction. The role of specific electronic states in the interfacial CT process was investigated by applying the core hole clock approach. CT times (τCT) on femtosecond and sub-femtosecond timescales were estimated using the S1s core-hole lifetime as the internal clock. Sub-femtosecond CT was observed for electrons excited to S3pz (0.34 fs) electronic states of MoS2 and to π* (C-C) (0.45 fs) electronic states of P3HT in the P3HT/MoS2/SiO2 heterojunction. These fast bidirectional CT processes result from strong coupling between these two electronic states in the P3HT/MoS2/SiO2 heterostructure. However, the reduction of the τCT values in the heterojunction compared with those of the isolated films shows that interfacial CT from the P3HT species to MoS2 is more efficient. Interfacial CT was not observed for electrons excited to electronic states S3px,y (MoS2) and σ* (S-C) (P3HT). We conclude that the π* (C-C) electronic state of the P3HT species is the main pathway for interfacial ultrafast CT in a P3HT/MoS2/SiO2 heterojunction.

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Graphene grown directly on germanium is a possible route for the integration of graphene into nanoelectronic devices as well as it is of great interest for materials science. The morphology of the interface between graphene and germanium influences the electronic properties and has not already been completely elucidated at atomic scale. In this work, we investigated the morphology of the single-layer graphene grown on Ge substrates with different crystallographic orientations. We determined the presence of sinusoidal ripples with a single propagation direction, zig-zag, and could arise due to compressive biaxial strain at the interface generated as a result of the opposite polarity of the thermal expansion coefficient of graphene and germanium. Local density of states measurements on the ripples showed a linear dispersion relation with the Dirac point slightly shifted with respect to the Fermi energy indicating that these out-of-plane deformations were n-doped, while the graphene regions between the highs were undoped.

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The purpose of this study is to determine the activation of the extrinsic and intrinsic apoptotic pathways in the cerebellum of rats exposed to amygdaloid electrical kindling. Western blot analyses were carried out for caspase-8 and caspase-9, Bid, Bax, and Bcl-2 in the cerebellum and immunohistochemistry of Bid, Bax, cytochrome C, and VDAC (voltage-dependent anion channels) in the cerebellar cortex of Wistar male rats with 0, 15, and 45 kindling stimulations. In the experimental group of 45 stimuli, we observed an increase in protein activation of caspase-9 and truncated Bid and Bax, in addition to a decrease in expression of pro-caspase-8 and the anti-apoptotic protein Bcl-2, determined by Western blot. Moreover, we observed a cytosolic immunopositivity for cytochrome C and a mitochondrial immunolocalization for truncated Bid and Bax in the group of 45 stimuli. In this work, we found an increase of caspase-8, a cysteine-protease that can activate caspase-3 triggering extrinsic apoptosis by signaling of death receptors. However, it also can activate the intrinsic pathway releasing Bid, which performs mitochondrial translocation of Bax, inactivating Bcl-2 and allowing the release of cytochrome C through the opening of the mitochondrial permeability transition pore, promoting the activation of caspase-9 which activates caspase-3, the main executor caspase of apoptosis. Therefore, it is concluded that there is an activation of the intrinsic and extrinsic apoptotic pathways in the cerebellum of rats exposed to the kindling model. Apoptosis signaling pathways can be analyzed as an important developing object of research about the epileptic activity. Graphical Abstract.

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Surface ozone is problematic to air pollution. It influences respiratory health. The air quality monitoring stations measure pollutants as surface ozone, but they are sometimes insufficient or do not have an adequate distribution for understanding the spatial distribution of pollutants in an urban area. In recent years, some projects have found a connection between remote sensing, air quality and health data. In this study, we apply an empirical land use regression (LUR) model to retrieve surface ozone in Quito. The model considers remote sensing data, air pollution measurements and meteorological variables. The objective is to use all available Landsat 8 images from 2014 and the air quality monitoring station data during the same dates of image acquisition. Nineteen input variables were considered, selecting by a stepwise regression and modelling with a partial least square (PLS) regression to avoid multicollinearity. The final surface ozone model includes ten independent variables and presents a coefficient of determination (R2) of 0.768. The model proposed help to understand the spatial concentration of surface ozone in Quito with a better spatial resolution.

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The thyroid descends through the foramen cecum leaving the thyroglossal duct, which disappears between the fifth and the tenth week of pregnancy. The lack of involution of any part of this duct results in thyroglossal cyst formation. Its diagnostic approach is made by cervical ultrasound, computed tomography and magnetic resonance imaging. Approximately 1 % of the thyroglossal cyst formation contains malignant elements, and the most reported primary tumor has been papillary carcinoma. The recommended treatment for these carcinomas is controversial and it has evolved as time goes by. From Sistrunk procedure to neck dissection with total thyroidectomy and complementary therapies, such as iodine ablation and thyroid supplements, yet there is still no consensus as to the type of surgery and postoperative management it should be used to treat this carcinoma. Therapy should be applied according to each specific case, and it should be based on histological diagnosis, the invasive character of the tumor, and the lymph node affectation. In this paper we review the literature published so far with regards to the treatment of this carcinoma.

La tiroides hace su descenso a través del foramen cecum y deja el conducto tirogloso, el cual desaparece entre la quinta y la décima semana de gestación. La falta de involución de cualquier parte de este conducto da lugar a la formación de quistes tiroglosos. Su evaluación se realiza por medio de ecografía cervical, tomografía computada y resonancia magnética. Aproximadamente el 1 % de los quistes tiroglosos contiene elementos malignos y el tumor primario que se ha documentado más ha sido el carcinoma papilar. El tratamiento recomendado para estos carcinomas es objeto de discusión; se ha usado desde la operación de Sistrunk hasta la disección cervical con tiroidectomía total y terapias complementarias como la ablación con yodo y los suplementos tiroideos; sin embargo, todavía no existe un consenso dominante en cuanto al tipo de intervención quirúrgica y su manejo postoperatorio. La terapia debe ser adaptada a cada caso, sobre el diagnóstico histológico, el carácter invasivo del tumor y la afectación de los ganglios linfáticos. En el presente escrito hemos realizado una revisión de la literatura respecto al tratamiento.

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A 2-month-old female infant was referred to DebRA Mexico from the Regional Children's Hospital because of a generalized dermatosis from birth characterized by multiple blisters and erosions on the trunk, face and limbs, associated with minor trauma. A skin biopsy showing subepidermal blisters associated with a dermal infiltrate of Giemsa-positive cells and CD117-positive antibody was consistent with the diagnosis of bullous mastocytosis. Treatment with oral antihistamines, topical steroids, and antibiotics was initiated, leading to a remission of the lesions.

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Cow's milk allergy (CMA) is an immune-based disease that has become an increasing problem. The diagnosis and management of CMA varies from one clinical setting to another and represents a challenge in pediatric practice. In addition, because nonallergic food reactions can be confused with CMA symptoms, there is an overdiagnosis of the disease. In response to these situations, pediatric specialties from recognized institutions throughout Latin America decided to develop a clinical guideline for diagnosis and management of cow's milk allergy. These guidelines include definitions, epidemiology, pathophysiology overview, clinical and evidencebased recommendations for the diagnosis and treatment of CMA. They also include prevention and prognosis sections and identify gaps in the current knowledge to be addressed through future research.

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OBJECTIVE: To identify the factors associated with level of knowledge and attitudes toward research among undergraduate medical students in Peru. METHODS: In this analytical cross-sectional study, a validated questionnaire on knowledge, attitudes, and practices related to research was applied to a representative sample of students at 17 Peruvian medical schools. The categorical and quantitative variables were subjected to simple two-factor analysis with adjustment for intraclass correlation. Prevalence ratios were derived on the basis of generalized linear models using bifactorial and multifactorial analysis. RESULTS: Questionnaires from 1 554 students (51.0% women) with an average age of 20.5 ± 2.86 years were analyzed. Only 46.7% of the respondents had a good level of knowledge and 37.7% had appropriate attitudes toward research. The variables that correlated with a good level of knowledge were the respondent having completed at least four years of academic study, belonging to a research group, and having an adviser. Having appropriate attitudes toward research correlated with being a woman and having an adviser. No differences were found between the level of knowledge and attitudes of the students at the universities studied. CONCLUSIONS: In general, the level of knowledge about research was unsatisfactory and the attitudes toward it were inappropriate. In order to change this situation, it will be critical to make changes in the curriculum to ensure that students engage in research from the beginning of their academic careers and develop research skills in their final years of study.

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OBJETIVO: Identificar los factores asociados con el nivel de conocimientos y la actitud relacionados con la investigación en los estudiantes de pregrado de la carrera de medicina en Perú. MÉTODOS: Estudio transversal analítico. Se aplicó un cuestionario validado sobre conocimientos, actitud y prácticas relacionados con la investigación a una muestra representativa de estudiantes de 17 facultades de medicina de Perú. Se realizó el análisis simple y bifactorial para las variables categóricas y cuantitativas, con ajuste de la correlación intraclase. Se modelaron las razones de prevalencia mediante análisis bifactorial y multifactorial con modelos lineales generalizados. RESULTADOS: Se analizaron los cuestionarios de 1 554 estudiantes (51,0% mujeres) con una edad promedio de 20,5 años ± 2,86. Solo 46,7% de los encuestados tenía un buen nivel de conocimientos y 37,7% una adecuada actitud hacia la investigación. Las variables asociadas con el buen nivel de conocimientos fueron: el año académico del encuestado a partir del 4.º, pertenecer a un grupo de investigación y contar con un asesor. Tener una adecuada actitud hacia la investigación se asoció con ser mujer y tener un asesor. No se encontraron diferencias entre el nivel de conocimientos y la actitud de los estudiantes de las universidades estudiadas. CONCLUSIONES: En general, el nivel de conocimientos sobre la investigación es deficiente y la actitud hacia ella, inadecuada. Para cambiar esta situación, es prioritario hacer cambios curriculares que garanticen la incorporación de los estudiantes a la investigación desde el inicio de la carrera y desarrollar competencias en investigación en los últimos años de estudio.

OBJECTIVE: To identify the factors associated with level of knowledge and attitudes toward research among undergraduate medical students in Peru. METHODS: In this analytical cross-sectional study, a validated questionnaire on knowledge, attitudes, and practices related to research was applied to a representative sample of students at 17 Peruvian medical schools. The categorical and quantitative variables were subjected to simple two-factor analysis with adjustment for intraclass correlation. Prevalence ratios were derived on the basis of generalized linear models using bifactorial and multifactorial analysis. RESULTS: Questionnaires from 1 554 students (51.0% women) with an average age of 20.5 ± 2.86 years were analyzed. Only 46.7% of the respondents had a good level of knowledge and 37.7% had appropriate attitudes toward research. The variables that correlated with a good level of knowledge were the respondent having completed at least four years of academic study, belonging to a research group, and having an adviser. Having appropriate attitudes toward research correlated with being a woman and having an adviser. No differences were found between the level of knowledge and attitudes of the students at the universities studied. CONCLUSIONS: In general, the level of knowledge about research was unsatisfactory and the attitudes toward it were inappropriate. In order to change this situation, it will be critical to make changes in the curriculum to ensure that students engage in research from the beginning of their academic careers and develop research skills in their final years of study.

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Introducción: El Síndrome Estafilocócico de Piel Escaldada (SEPE) es una entidad con mayor incidencia de morbilidad en la población pediátrica, además, no cuenta con estudios previos que describan el comportamiento de la enfermedad en una población de pacientes pediátricos peruanos. OBJETIVO: Describir las características clínico- epidemiológicas y terapéuticas en niños hospitalizados con el diagnóstico de SEPE, en el Servicio de Dermatología del INSN, entre 1995 y 2010. MÉTODOS: Estudio observacional, descriptivo, retrospectivo de revisión de historias clínicas. RESULTADOS: De los pacientes estudiados, el 51,9 por ciento son de género masculino. El período prodrómico de la enfermedad es caracterizado por la presencia temprana de irritabilidad (39,2 por ciento). El 68,5 por ciento de los pacientes presentaron como manifestación clínica inicial, máculas eritematosas de distribución principalmente en cara (81 por ciento) Y cuello (50 por ciento), las cuales eran en su mayoría periorificiales. En el tratamiento durante hospitalización, se obtuvo que la Oxacilina fue el fármaco endovenoso más usado (86.1 por ciento), durante aproximadamente 5 días. CONCLUSIONES: Se encontró mayor incidencia en el género masculino. La población afectada pertenece principalmente a un nivel socioeconómico bajo o muy bajo (81 por ciento), Suele encontrarse irritabilidad como síntoma cardinal en el período prodrómico, máculas eritematosas y luego descamación, como manifestaciones clínicas temprana y tardía respectivamente...

INTRODUCTION: Staphylococcal Scalded Skin Syndrome (SEPE) is a greater incidence of disease in the pediatric population also has no previous studies that describe the behavior of the disease in a pediatric population of Peru. BJECTIVE: To describe the clinical and epidemiological features and treatment in children hospitalized with the diagnosis of SEPE in INSN Dermatology Service, between 1995 and 2010. METHODS: An observational, descriptive, retrospective review of medical records. RESULTS: Of the patients studied, 51.9 per cent are male. The prodromal period of the disease is characterized by me early presence of irritability (39.2 per cent). 68.5 per cent of the patients as initial clinical manifestation, mainly distribution erythematous macules on the face (81 per cent) and neck [50 per cent), which were mostly periorificial. Treatment during hospitalization, we found that oxacillin was the drug most commonly used intravenous (86.1 per cent), for about 5 days. CONCLUSIONS: We found a higher incidence in males. The affected population belongs mainly to low socioeconomic status or low (81 per cent), irritability is usually found as a cardinal symptom in the prodromal period, and then scaling erythematous macules as clinical early and late respectively...

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CASE: We report the case of a 21-year old female with multiple surgeries. Her problem began after last surgery, which got complicated by a diaphragmatic perforation on the left side so it was necessary to repair the defect with a plastic prosthesis, since that time she complained of abdominal pain. In an abdominal computed axial tomography prosthesis was observed and by endoscopy its presence into stomach was confirmed, because its size and rigidity its endoscopic extraction was impossible, so it was surgically extracted. One and half month after surgery the patient's evolution was satisfactory. DISCUSSION: Migration is one of the most common complications of medical prosthesis placed into abdominal cavity. However precise incidence is unknown, neither intraluminal migration to the gastrointestinal tract. We didn't find previews reports about intragastric migration of a prosthesis that was used to repair a diaphragmatic defect.

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