General model for the kinetics of solute diffusion at solid-solid interfaces

Solute diffusion through solid-solid interfaces is paramount to many physical processes. From a modeling point of view, the discontinuities in the energy landscape at a sharp interface represent difficulties in predicting solute diffusion that, to date, have not been solved in a consistent manner across length scales. Using an explicit finite volume method, this work is the first to derive numerical solutions to the diffusion equations at a continuum level while including discrete variations in the energy landscape at a bicrystal interface. An atomic jump equation consistent with atomistic descriptions is derived and scaled up into a compendium of model interfaces: monolayer energy barriers, monolayer interfacial traps, multilayered traps, and heterogeneous interfaces. These can track solute segregation behavior and long-range diffusion effects. We perform simulations with data for hydrogen diffusion in structural metals, of relevance to the assessment of the hydrogen embrittlement phenomenon, and point defects in electronic devices. The approach developed represents an advancement in the mathematical treatment of solute diffusion through solid-solid interfaces and an important bridge between the atomistic and macroscopic modeling of diffusion, with potential applications in a variety of fields in materials science and physics

Optimisation of the hydrogen bake-out treatment in steels via Gaussian processes

The presence of hydrogen in structural alloys reduces their ductility, a phenomenon called hydrogen embrittlement. Bake-out heat treatments are employed during processing to allow hydrogen trapped in microstructural features to effuse from the samples, but the optimal times and temperatures depend on the kinetics of hydrogen diffusion in the material. In this work, Gaussian process surrogate models are employed to emulate the outputs of microstructure-sensitive diffusion differential equations in steel. Training the models by sequentially increasing the number of dimensions results in better performances and shorter training times. Two main approaches are developed: single output models with experimental design for the prediction of optimal bake-out times, and multi-output principal component analysis models for the prediction of hydrogen concentration evolution. A novel approach is implemented to shorten the training times of multi-trap models by exploiting the symmetry of the equations with respect to different kinds of traps. The resulting models pave the way for the implementation of Gaussian processes on more computationally expensive diffusion simulations for the optimisation of heat treatments and other applications

Linfangiectasia intestinal primaria: 20 años de experiencia en el Instituto Nacional de Pediatría

ResumenAntecedentesLa linfangiectasia intestinal primaria es una enfermedad congénita rara descrita por Waldmann en 1961, y que es consecuencia de una obstrucción del drenaje linfático del intestino delgado con dilatación secundaria de los vasos linfáticos, que distorsionan la arquitectura de las vellosidades ocasionando pérdida de linfa hacia la luz intestinal,dando como resultado una enteropatía perdedora de proteínas y malabsorción de nutrimentos.ObjetivoDescribir las características clínicas, bioquímicas, radiológicas, endoscópicas e histológicas en niños con linfangiectasia intestinal primaria.MétodoEstudio observacional, descriptivo, transversal y retrospectivo de niños con linfangiectasia intestinal primaria que fueron vistos en el Servicio de Gastroenterología y Nutrición del Instituto Nacional de Pediatría desde el 1 de enero de 1992 al 30 de septiembre de 2012, en donde se revisaron los expedientes clínicos de los niños con este diagnóstico.ResultadosSe encontraron 4 pacientes con linfangiectasia intestinal primaria, 3 de ellos diagnosticados antes de los 3 años; todos se presentaron con diarrea crónica, edema, linfopenia, hipocalcemia, hipoalbuminemia e hipogammaglobulinemia, y en 3 pacientes, con hipocolesterolemia, y con tránsito intestinal, endoscopia y biopsias intestinales características de esta enfermedad.ConclusionesLa linfangiectasia intestinal debe sospecharse ante un cuadro de diarrea crónica, enteropatía perdedora de proteínas, que se acompaña de edema a cualquier nivel, así como hipoalbuminemia, hipocalcemia, linfopenia, hipogammaglobulinemia e hipocolesterolemia como los principales hallazgos bioquímicos de esta entidad. Ante esta enfermedad debe realizarse estudio de serie esofagogastroduodenal con tránsito intestinal y endoscopia con toma de biopsias a nivel de duodeno. El tratamiento incluye dieta y administración periódica de albúmina y gammaglobulina.AbstractBackgroundPrimary intestinal lymphangiectasia is a rare congenital disease described by Waldmann in 1961 that is a consequence of obstruction of the lymphatic drainage of the small bowel with secondary lymph vessel dilation. This distorts the architecture of the villi and causes a leakage of lymph into the intestinal lumen, resulting in protein-losing enteropathy and malabsorption.AimTo describe the clinical, biochemical, radiologic, endoscopic, and histologic characteristics in children with primary intestinal lymphangiectasia.MethodA retrospective observational, descriptive, cross-sectional study was conducted that reviewed the case records of children diagnosed with primary intestinal lymphangiectasia that were seen at the Department of Gastroenterology and Nutrition of the Instituto Nacional de Pediatría within the time frame of January 1, 1992 to September 30, 2012.ResultsFour patients were found that presented with primary intestinal lymphangiectasia. Three of them had been diagnosed before 3 years of age. All the patients presented with chronic diarrhea, edema, lymphopenia, hypocalcemia, and hypogammaglobulinemia, and 3 patients presented with hypocholesterolemia. Bowel transit time, endoscopy, and intestinal biopsies were characteristic of this pathology.ConclusionsIntestinal lymphangiectasia should be suspected when there is a clinical picture of chronic diarrhea and protein-losing enteropathy accompanied with edema at any level, as well as hypoalbuminemia, hypocalcemia, lymphopenia, hypogammaglobulinemia, and hypocholesterolemia, which are the main biochemical findings of this pathology. All children presenting with intestinal lymphangiectasia should undergo an upper gastrointestinal series with bowel transit time and endoscopy with biopsies taken at the level of the duodenum. Treatment includes diet and the periodic administration of albumin and gamma globulin

Identification of latexin by a proteomic analysis in rat normal articular cartilage

<p>Abstract</p> <p>Background</p> <p>Osteoarthritis (OA) is characterized by degeneration of articular cartilage. Animal models of OA induced are a widely used tool in the study of the pathogenesis of disease. Several proteomic techniques for selective extraction of proteins have provided protein profiles of chondrocytes and secretory patterns in normal and osteoarthritic cartilage, including the discovery of new and promising biomarkers. In this proteomic analysis to study several proteins from rat normal articular cartilage, two-dimensional electrophoresis and mass spectrometry (MS) were used. Interestingly, latexin (LXN) was found. Using an immunohistochemical technique, it was possible to determine its localization within the chondrocytes from normal and osteoarthritic articular cartilage.</p> <p>Results</p> <p>In this study, 147 proteins were visualized, and 47 proteins were identified by MS. A significant proportion of proteins are involved in metabolic processes and energy (32%), as well as participating in different biological functions including structural organization (19%), signal transduction and molecular signaling (11%), redox homeostasis (9%), transcription and protein synthesis (6%), and transport (6%). The identified proteins were assigned to one or more subcellular compartments.</p> <p>Among the identified proteins, we found some proteins already recognized in other studies such as OA-associated proteins. Interestingly, we identified LXN, an inhibitor of mammalian carboxypeptidases, which had not been described in articular cartilage. Immunolabeling assays for LXN showed a granular distribution pattern in the cytoplasm of most chondrocytes of the middle, deep and calcified zones of normal articular cartilage as well as in subchondral bone. In osteoarthritic cartilage, LXN was observed in superficial and deep zones.</p> <p>Conclusions</p> <p>This study provides the first proteomic analysis of normal articular cartilage of rat. We identified LXN, whose location was demonstrated by immunolabeling in the chondrocytes from the middle, deep and calcified zones of normal articular cartilage, and superficial and deep zones of osteoarthritic cartilage.</p

The orosomucoid 1 protein (α1 acid glycoprotein) is overexpressed in odontogenic myxoma

Odontogenic myxoma (OM) is a benign, but locally invasive, neoplasm occurring in the jaws. However, the molecules implicated in its development are unknown. OM as well as Dental Follicle (DF), an odontogenic tissue surrounding the enamel organ, is derived from ectomesenchymal/mesencyhmal elements. To identify some protein that could participate in the development of this neoplasm, total proteins from OM were separated by two-dimensional electrophoresis and the profiles were compared with those obtained from DF, used as a control

APROVECHAMIENTO ALIMENTARIO DE INFLORESCENCIAS EN LA REGIÓN SIERRA DEL ESTADO DE TABASCO

This paper presents results from the research project named “Identification of theTraditional Alimentary Culture in the Stateof Tabasco”, SIGOLFO 97-06-007-T. Basedon questionnaires distributed in communities about 100 and 500 inhabitants, at leastone of them in each community being anindigenous speaker, it was found that theirinhabitants, for ancestral and cultural customs, are devoted to gathering plant species for supplying supplementary sustenance. The most important alternative vegetable source being gathered is inflorescences of species like Erythrinaamericana Mill., Calathea macrosepala(Aubl.) Lindl., Spathiphyllum phryniifolium Schott, Astrocaryum mexicanumLiebm., Chamaedora sp. aff. pinnatifronsLiebm. ex Mart. y Chamaedora cataractarum (Mart.). It was found that the consumption of inflorescences prevails in these communities as a nutrition base during periodsof food shortage or special celebrationssuch as Holy Week when Catholics do noteat meat.La presente información es parte de los resultados encontrados en el proyecto de investigación “Identificación de la CulturaAlimentaria Tradicional en el Estado deTabasco”, SIGOLFO 97-06-007-T. Con baseen la aplicación de cuestionarios en comunidades comprendidas entre 100 y 500 habitantes con al menos uno de ellos conhabla indígena, se encontró que por costumbres ancestrales y culturales se dedican a la recolección de especies vegetalespara suplementar su fuente de alimentación, con especies vegetales alternativas,siendo de gran importancia la recolecciónde inflorescencias de especies como:Erythrina americana Mill, Calatheamacrosepala (Aulb.) Lindl., Spathiphyllum phryniifolium Schoot,Astrocaryum mexicanum Liebmann,Chamaedora sp. aff. pinnatifrons Liebm.ex Mart y Chamaedora cataractarum(Mart). Se pudo constatar que prevaleceen las comunidades un gran arraigo delconsumo de especies con inflorescenciacomo una base de la alimentación durantelos periodos de escasez de alimentos o durante festividades como la Semana Santa,época en la cual de manera tradicional no se consume carne de ninguna especie yrara vez pescado o pollo

Investigation of Different Iontophoretic Currents Profiles for Short-Term Applications in Cosmetics

[EN] This study aimed at investigating the effect of electrical current profile upon the iontophoretic transport of (i) ascorbic acid (AA) and (ii) ellagic acid (EA), into porcine skin in vitro, and the impact of the physicochemical properties of both actives on their mechanism of transport when formulated in cosmetic compositions. The experiments were performed using a proprietary iontophoretic device containing a roller to apply the formulation. Three current profiles were tested: (i) galvanic direct current (DC), (ii) square unipolar pulse current (SPC), and (iii) galvanic direct current (DC) + pulse current (PC). The skin samples were collected at different sampling points, extracted and analyzed by HPLC. Results suggested that the DC + PC mode for only 5 min was able to significantly increase the delivery of AA from o/w cosmetic compositions. The use of this current profile might improve the skin penetration of AA due to electromigration and passive diffusion, the latter being facilitated by the physical enhancement method. The SPC mode significantly improved the passage of EA in its neutral form from cosmetic o/w formulations by electroosmosis. Tailoring specific electrical current modes considering the ionization state of active ingredients would allow the design of short and personalized cosmetic treatments that significantly improve the penetration efficiency of the active ingredients and possibly reduce the doses applied.This research was entirely funded by L'Oreal, France.Cázares-Delgadillo, J.; Planard-Luong, L.; Gregoire, S.; Serna-Jiménez, CE.; Singhal, M.; Kalia, YN.; Merino Sanjuán, V.... (2018). Investigation of Different Iontophoretic Currents Profiles for Short-Term Applications in Cosmetics. Pharmaceutics. 10(4). https://doi.org/10.3390/pharmaceutics10040266266104R. Hamad, A.-W., Al-Momani, W. M., Janakat, S., & A. Oran, S. (2009). Bioavailability of Ellagic Acid After Single Dose Administration Using HPLC. Pakistan Journal of Nutrition, 8(10), 1661-1664. doi:10.3923/pjn.2009.1661.1664Kalia, Y. N., Naik, A., Garrison, J., & Guy, R. H. (2004). Iontophoretic drug delivery. Advanced Drug Delivery Reviews, 56(5), 619-658. doi:10.1016/j.addr.2003.10.026Marro, D., Kalia, Y. N., Begoña Delgado‐Charro, M., & Guy, R. H. (2001). Pharmaceutical Research, 18(12), 1701-1708. doi:10.1023/a:1013318412527Sobhi, R. M., & Sobhi, A. M. (2012). A single-blinded comparative study between the use of glycolic acid 70% peel and the use of topical nanosome vitamin C iontophoresis in the treatment of melasma. Journal of Cosmetic Dermatology, 11(1), 65-71. doi:10.1111/j.1473-2165.2011.00599.xHori, Y., Akimoto, R., Hori, A., Kato, K., Chino, D., Matsumoto, S., … Watanabe, Y. (2010). Skin collagen reproduction increased by ascorbic acid derivative iontophoresis by frequent-reversal bipolar electric stimulation. International Journal of Cosmetic Science, 32(3), 234-234. doi:10.1111/j.1468-2494.2010.00577_3.xJunyaprasert, V. B., Singhsa, P., Suksiriworapong, J., & Chantasart, D. (2012). Physicochemical properties and skin permeation of Span 60/Tween 60 niosomes of ellagic acid. International Journal of Pharmaceutics, 423(2), 303-311. doi:10.1016/j.ijpharm.2011.11.032Maia, A. M., Baby, A. R., Pinto, C. A. S. O., Yasaka, W. J., Suenaga, E., Kaneko, T. M., & Velasco, M. V. R. (2006). Influence of sodium metabisulfite and glutathione on the stability of vitamin C in O/W emulsion and extemporaneous aqueous gel. International Journal of Pharmaceutics, 322(1-2), 130-135. doi:10.1016/j.ijpharm.2006.05.03