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In this study, we synthesized Co2P nanoparticles using a solid-state phosphorization method and evaluated the electrocatalytic response to glucose oxidation reaction (GORs). The influence of synthesis conditions on the particle size, morphology of Co2P species and formation of byproducts is discussed. A lower molar ratio of the phosphorus precursor leads to a decrease in the generation of byproducts. In addition, the calcination temperature and time greatly influence the purity level of the Co2P species and its particle size. Thus, we obtained three pure Co2P nanoparticles with different sizes and morphologies. Significant differences in their electrocatalytic activity against the GOR are observed depending on the size of the particles, being the smaller ones the most efficient. Based on Tafel analysis, a higher catalytic activity was observed for the carbon fibre (CF)/Co2P composite compared to Co2P, which presented a greater onset potential and low response in current density. Tafel slopes close to 120 mV/dec were obtained for both materials, indicating that the mechanism is independent of the type of Co2P-based material used. Finally, the performance of the GCE/CF/Co2P sensor was demonstrated by amperometric measurements, with a sensitivity of 409 µAmM-1cm-2, a linear range between 39.4 µM and 150 µM, and a detection limit of 0.97 µM, analytical characteristics better than those obtained for other cobalt phosphide-based sensors reported in the literature. In addition, the GCE/CF/Co2P sensor shows excellent selectivity and demonstrated to be competitive compared to other Co-based non-enzymatic glucose sensors.

In this work, two commercial extruded filaments for 3D printing obtained from different NatureWorks PLA resins (Ingeo™ Biopolymer 3D850 and Ingeo™ Biopolymer 4043D) were solid-state drawn at varying temperatures and subsequently heat treated by annealing. The aim was to analyze the effect of post-processing of industrial fibers (solid-state drawing and annealing treatment) with varied composition (PLA grades with different contents of D-isomer) on the mechanical performance and thermal stability of the obtained PLA fibers. Morphological, thermal, and mechanical characterizations were performed for the undrawn filaments and drawn fibers, both before and after heat treatment. Drawn fibers presented a fibrillar core–shell structure, and their mechanical properties were greatly improved with respect to undrawn filaments in accordance with their higher crystallinity. The resin with the higher content of D-isomer (4043D) resulted in lower crystallinities with a subsequent decrease in mechanical properties. After heat treatment, drawn fibers exhibited completely different behaviors depending on the PLA resin, with 3D850 fibers being much more stable than 4043D fibers, which underwent molecular orientation upon drawing rather than crystallization. The solid-state drawn fibers obtained herein are comparable to commercial fibers in terms of mechanical properties.

RESUMO Este estudo teve como objetivos identificar estudantes com talento matemático no Ensino Fundamental e no Ensino Médio, no que se refere ao sistema numérico maia e babilônico para o Ensino Fundamental e ao pensamento computacional, com o uso do Scratch, para o Ensino Médio; projetar e implementar um programa de enriquecimento extraescolar com alunos do Ensino Fundamental e do Ensino Médio; estudar a evolução das ideias matemáticas, trabalhadas no programa de enriquecimento extracurricular. O aporte teórico foi baseado no Modelo de Enriquecimento para toda a Escola (School Wide Enrichment Model - SEM). Esse modelo teve origem no Modelo Triádico de Enriquecimento de Renzulli. Os resultados apresentados referem-se às atividades de enriquecimento extracurricular, com numeração babilônica e o sistema numérico maia, e as atividades em ambiente Scratch. Os resultados do estudo mostraram que ambos os grupos de idade foram capazes de abordar as atividades propostas e desenvolveram experiências de aprendizado que lhes deram habilidades para resolver problemas matemáticos, tanto no ambiente a lápis e papel quanto na linguagem de programação Scratch. O grupo de alunos do Ensino Fundamental representou números no sistema maia e babilônico e realizou operações aritméticas; dessa forma, este trabalho os ajudou a compreender o sistema posicional; e os estudantes do Ensino Médio aprenderam a fazer animações de dois personagens (sprites) e aprenderam a programar.

This paper analyses the tangible and intangible Yagan heritage contents exhibited by the Museo del Fin del Mundo (MFM, Ushuaia, Tierra del Fuego, Argentina) and presented during its guided tour led by Yagan Community Counsellor Victor Vargas Filgueira. We show how the critical outlook of Fuegian history offered in the latter challenges the traditional past-only fossilized view of the Yagan, building past–present links and helping to overcome biased hegemonic discourses. We also discuss how employing a member of the Yagan Community at the MFM has been an efficient and low-budget strategy that helps to comply with some Goals of the UN 2030 Agenda for Sustainable Development, which are difficult to attain in developing countries. Significant outcomes of this process include: (a) providing a full-time formal job to a member of an Indigenous Community who has been traditionally dispossessed of/in their own territory; (b) acknowledging him as a knowledge holder and valuable member of society; (c) moving the role of Yagan People from subject to agent of the MFM. This process has fostered the dialogue between Yagan voices and academic discourses, challenging traditional Western dichotomies-ecology/economy, natural/cultural heritage, and so forth, and contributing to the discussion of key concepts on sustainability and engagement.

The evaluation of the quality of electric power distribution services in Brazil is regulated and monitored by the National Electric Energy Agency ANEEL, which uses metrics related to the duration frequency of power interruptions that occur in the power utilities’ networks. The methodology applied by the agency to establish financial compensation due to violations of the quality standards does not take into consideration the consumers’ production industry when establishing compensation for the transgression of service quality indicators. This study will analyze a case study of a group of industrial consumers linked to agribusiness in the southern region of Brazil, which have strongly seasonal use of distribution networks and are scattered in large, dispersed areas. Based on the evaluation of the impact of service quality indicators on financial compensation, a regulatory mechanism is proposed in the form of an interruptible tariff duly quantified in the form of a non-linear programming problem to find a discount range for uninterruptible tariffs. The results obtained with the real data for the group of irrigating consumers demonstrate the feasibility regarding the application of the proposed approach, whether due to the discounts offered or even the repercussions of the calculated financial amounts.

En este trabajo se analizan los artefactos producidos por poblaciones indígenas fueguinas expuestos en la exhibición antropológica/arqueológica del Museo del Fin del Mundo, ubicado en la ciudad de Ushuaia (Tierra del Fuego, Argentina), a fin de indagar en su proceso de patrimonialización como objetos museográficos. Para ello, se describe analíticamente dicha exhibición y se analizan: (a) los artefactos expuestos –arqueológicos, etnográficos y contemporáneos– y (b) la información escrita y visual asociada a dichos artefactos. De esta manera, se propone una aproximación a parte de los procesos de formación de la colección expuesta, centrándonos en discutir el proceso de selección y patrimonialización de estos objetos museográficos. Así, se indagan y discuten los contenidos, discursos e imaginarios que transmite el museo acerca del patrimonio cultural de los pueblos originarios fueguinos.

Background Although rare, classic viral myocarditis in the pediatric population is a disease that carries significant morbidity and mortality. Since 2020, myocarditis has been a common component of multisystem inflammatory syndrome in children (MIS‐C) following SARS‐CoV‐2 infection. In 2021, myocarditis related to mRNA COVID‐19 vaccines was recognized as a rare adverse event. This study aims to compare classic, MIS‐C, and COVID‐19 vaccine‐related myocarditis with regard to clinical presentation, course, and outcomes. Methods and Results In this retrospective cohort study, we compared patients aged

Biomedicine requires materials able to respond to specific needs without affecting the organism. Organic–inorganic fibrillar polymeric matrices possess unique properties that may fulfill these needs. In the present study, different topology-controlled poly(ε-caprolactone)-based fibrillar matrices containing glycine betaine at varying concentrations (0.5, 1, and 2% w/v) were prepared via electrospinning. The matrices were used as substrates in calcium carbonate crystallization assays with gas diffusion to obtain a single organic–inorganic hybrid material. The resulting matrices and crystalline material were characterized using spectroscopic, microscopic, and thermogravimetric analyses. The incorporation of glycine betaine into a poly(ε-caprolactone) mesh modified the diameter of the fibers, without affecting the thermal behavior of the matrices. However, the chemical and morphological characteristics of the matrices did influence in vitro inorganic mineralization. The thermogravimetric analysis of the matrices, performed after the mineralization tests, demonstrated the existence of a new organic–inorganic hybrid material with unique properties, which is discussed in the present study.

In the rural regions of southern Brazil, electricity is largely directed to irrigation activities on rice crops at restricted periods of the year. Typically, customers in these regions are called “irrigators”, and have some characteristics different from loads in urban centers, such as high demand levels and sharp load variations. These characteristics can result in problems of excessive loading on distribution grids at certain times of the day, generating concerns for the power utilities in relation to the security of the electrical system, energy supply to customers, and the integrity of electrical equipment. An alternative to avoid or mitigate these possible problems may be the application of a demand management model to irrigator customers. In this context, a load shifting strategy can be inserted to reduce demand in more critical periods and move it to intervals with lower load on the power grid. In this context, this article presents a demand-side management methodology in distribution systems located in rural areas, employing the load shifting strategy for irrigator customers. The methodology proposed in this paper is not an entirely novel approach, but one specifically developed for the context of irrigator customers, a subject little studied in the literature. The load management model proposed by this study is segmented into three hierarchical levels. The first level is the identification of the electrical characteristics of the distribution systems, the second level is the power flow analysis of the distribution networks, and the third and last level consists in the application of load shifting to the irrigator customers of these electrical systems. The load shifting strategy is modeled by a linear programming algorithm and is only applied to irrigator customers in situations of excessive loading on power grid. The case studies were conducted on three distribution systems of a power utility, with more than 150 irrigator customers. The DSM model based on the load shifting strategy reduced the maximum demand and daily load variations on the three rural feeders evaluated. The proposed changes in load patterns can ensure the continuity of electric power supply service in future even with the high concentration of load on distribution networks, benefiting customers and power utilities.

In the last decade, we have witnessed an upsurge in nuclei-based studies, particularly coupled with next-generation sequencing. Such studies aim at understanding the molecular states that exist in heterogeneous cell populations by applying increasingly more affordable sequencing approaches, in addition to optimized methodologies developed to isolate and select nuclei. Although these powerful new methods promise unprecedented insights, it is important to understand and critically consider the associated challenges. Here, we provide a comprehensive overview of the rise of nuclei-based studies and elaborate on their advantages and disadvantages, with a specific focus on their utility for transcriptomic sequencing analyses. Improved designs and appropriate use of the various experimental strategies will result in acquiring biologically accurate and meaningful information.

En este trabajo indagaremos en los diferentes ritmos que tuvo la adopción de cultura material occidental por parte de la sociedad Yagán de Tierra de Fuego desde fines del siglo XIX hasta mediados del siglo XX. Para ello, centraremos el análisis en un corpus de 428 fotografías etnográficas de este pueblo originario, obtenidas entre 1881 y 1987 en Tierra del Fuego, a fin de analizar de manera diacrónica la adopción desigual de cultura material occidental, específicamente respecto de la vestimenta y los adornos. De esta manera, esperamos discutir los distintos procesos desarrollados respecto de esta cultura material a partir del contacto con los europeos: adopción plena, adopción parcial (ciclaje), reciclaje y resiliencia. Así, encontramos que los yaganes fueron agentes activos de su propio cambio cultural, que tuvo distintos ritmos vinculados a procesos de negociación y resiliencia, que permitieron la supervivencia física y cultural de este Pueblo Originario.

En este artículo presentaremos un panorama sistemático acerca las condiciones de accesibilidad a las fotografías etnográficas de indígenas patagónico-fueguinos, a fin de evaluar y discutir las posibilidades reales de ejercer el derecho de acceso público a la información que aportan estos documentos. Primero, indagaremos en el nuevo lugar que ocupa la fotografía en la investigación en ciencias sociales y en el rol que cumplen los archivos en la custodia de estos documentos. Luego, analizaremos de manera rigurosa la localización y las condiciones de accesibilidad a las 1465 fotografías relevadas en un total de 13 archivos, tanto públicos como privados y tanto centrales como locales y extranjeros. Para ello, analizaremos: a) la cantidad de fotografías conservadas en cada archivo, b) la existencia de datos contextuales como autor, fecha, lugar y epígrafe, c) las condiciones de preservación, d) el orden, clasificación y descripción, e) la consulta y el acceso y f) la difusión de cada archivo. Finalmente, indagaremos en cómo estos problemas de accesibilidad al patrimonio fotográfico indígena obstaculizan una valoración real de la historia, la memoria y la identidad.

Birk-Barel intellectual disability is an imprinting syndrome due to maternally-only transmitted mutations of KCNK9/TASK3. Here authors are using a heterozygous deletion of the active maternal Kcnk9 allele to model the disease and show phenotypic rescue by HDAC inhibition.

An electrospinning method was used for the preparation of an in situ composite based on Ni2P nanoparticles and carbon fiber (FC). The material was tested for the first time against direct glucose oxidation reaction. The Ni2P nanoparticles were distributed homogeneously throughout the carbon fibers with a composition determined by thermogravimetric analysis (TGA) of 40 wt% Ni2P and 60 wt% carbon fiber without impurities in the sample. The electrochemical measurement results indicate that the GCE/FC/Ni2P in situ sensor exhibits excellent catalytic activity compared to the GCE/Ni2P and GCE/FC/Ni2P ex situ electrodes. The GCE/FC/Ni2P in situ sensor presents a sensitivity of 1050 µAmM−1cm−2 in the range of 5–208 µM and a detection limit of 0.25 µM. The sensor was applied for glucose detection in artificial saliva, with a low interference observed from normally coexisting electroactive species. In conclusion, our sensor represents a novel and analytical competitive alternative for the development of non-enzymatic glucose sensors in the future.

Potential drug-eluting scaffolds of electrospun poly(acrylic acid-co-styrene sulfonate) P(AA-co-SS) in clonogenic assays using tumorigenic gastric and ovarian cancer cells were tested in vitro. Electrospun polymer nanofiber (EPnF) meshes of PAA and PSSNa homo- and P(AA-co-SS) copolymer composed of 30:70, 50:50, 70:30 acrylic acid (AA) and sodium 4-styrene sulfonate (SSNa) units were performed by electrospinning (ES). The synthesis, structural and morphological characterization of all EPnF meshes were analyzed by optical and electron microscopy (SEM-EDS), infrared spectroscopy (FTIR), contact angle, and X-ray diffraction (XRD) measurements. This study shows that different ratio of AA and SSNa of monomers in P(AA-co-SS) EPnF play a crucial role in clonogenic in vitro assays. We found that 50:50 P(AA-co-SS) EPnF mesh loaded with antineoplastic drugs can be an excellent suppressor of growth-independent anchored capacities in vitro assays and a good subcutaneous drug delivery system for chemotherapeutic medication in vivo model for surgical resection procedures in cancer research.

Abstract Background There are complex interactions between aging, frailty, diet, and the gut microbiota; modulation of the gut microbiota by diet could lead to healthier aging. The purpose of this study was to test the effect of diets differing in sugar, fat, and fiber content upon the gut microbiota of mice humanized with microbiota from healthy or frail older people. We also performed a 6-month dietary fiber supplementation in three human cohorts representing three distinct life-stages. Methods Mice were colonized with human microbiota and then underwent an 8-week dietary intervention with either a high-fiber/low-fat diet typical of elderly community dwellers or a low-fiber/high-fat diet typical of long-stay residential care subjects. A cross-over design was used where the diets were switched after 4 weeks to the other diet type to identify responsive taxa and innate immunity changes. In the human intervention, the subjects supplemented their normal diet with a mix of five prebiotics (wheat dextrin, resistant starch, polydextrose, soluble corn fiber, and galactooligo-saccharide) at 10 g/day combined total, for healthy subjects and 20 g/day for frail subjects, or placebo (10 g/day maltodextrin) for 26 weeks. The gut microbiota was profiled and immune responses were assayed by T cell markers in mice, and serum cytokines in humans. Results Humanized mice maintained gut microbiota types reflecting the respective healthy or frail human donor. Changes in abundance of specific taxa occurred with the diet switch. In mice with the community type microbiota, the observed differences reflected compositions previously associated with higher frailty. The dominance of Prevotella present initially in community inoculated mice was replaced by Bacteroides, Alistipes, and Oscillibacter. Frail type microbiota showed a differential effect on innate immune markers in both conventional and germ-free mice, but a moderate number of taxonomic changes occurring upon diet switch with an increase in abundance of Parabacteroides, Blautia, Clostridium cluster IV, and Phascolarctobacterium. In the human intervention, prebiotic supplementation did not drive any global changes in alpha- or beta-diversity, but the abundance of certain bacterial taxa, particularly Ruminococcaceae (Clostridium cluster IV), Parabacteroides, Phascolarctobacterium, increased, and levels of the chemokine CXCL11 were significantly lower in the frail elderly group, but increased during the wash-out period. Conclusions Switching to a nutritionally poorer diet has a profound effect on the microbiota in mouse models, with changes in the gut microbiota from healthy donors reflecting previously observed differences between elderly frail and non-frail individuals. However, the frailty-associated gut microbiota did not reciprocally switch to a younger healthy-subject like state, and supplementation with prebiotics was associated with fewer detected effects in humans than diet adjustment in animal models.

Este artículo de investigación es el resultado de un proyecto de investigación sobre el pensamiento algebraico temprano en entornos tecnológicos de aprendizaje y se reportan resultados sobre el razonamiento proporcional como una ruta de acceso al pensamiento algebraico temprano. El estudio fue realizado con 109 estudiantes de educación básica de escuelas públicas, del Estado de México y de la Ciudad de México y uno de los objetivos del estudio fue validar un instrumento sobre el razonamiento proporcional. Para ello, se utilizó una metodología mixta, un estudio de tipo observacional, longitudinal y comparativo con tres etapas: 1. Evaluación inicial sobre el razonamiento proporcional, 2.Validación de un instrumento sobre el razonamiento proporcional, 3. Entrevista clínica abierta. Los resultados revelan que los alumnos logran comprender ideas de proporcionalidad aritmética y geométrica y variación proporciona, y comprenden los problemas que involucran la relación funcional, como una consecuencia del tránsito del pensamiento aditivo al multiplicativo. En lo que respecta al instrumento de evaluación, se propuso un modelo hipotético de validez convergente y divergente de constructo en la medición del razonamiento proporcional y el modelo resultante obtuvo aceptables indicadores prácticos de bondad de ajuste y coeficientes de confiabilidad altos. Además el instrumento mostró tener validez convergente y divergente de constructo. Finalmente, podemos concluir que el razonamiento proporcional es una ruta viable hacia el pensamiento algebraico, a pesar de que los estudiantes no han desarrollado aún todas las estructuras cognitivas y matemáticas para comprender la complejidad del pensamiento proporcional, los resultados de este estudio permitieron dilucidar etapas tempranas en el desarrollo cognitivo de los niños con tareas y enfoques pertinentes.

Se reportan resultados de un estudio sobre los procesos de generalización como una vía de acceso a la introducción temprana al pensamiento algebraico, con 109 estudiantes de educación básica de escuelas públicas, México. El trabajo experimental consistió de tres etapas: 1. Evaluación inicial sobre procesos de generalización, 2. Validación de un instrumento sobre procesos de generalización, 3 Entrevista clínica abierta. Los resultados muestran que los alumnos logran comprender ideas básicas de variación proporcional, describir un patrón y formular una regla general, a medida que transitaban del pensamiento aditivo al multiplicativo En lo que respecta al instrumento de evaluación, éste posee validez convergente y divergente de constructo.

External skeletal fixation has been used for the management of fractures of many types of bone. The use of polymeric free-form connecting bars in external fixators has become widely used in veterinary orthopaedics because of its versatile forms of frame construction and its relative low costs. Determining thermal-transfer to trans fixation pins during polymerisation of poly(methyl methacrylate) and epoxy putty polymers used for free-form external skeletal fixation connecting bars is important for avoiding temperatures of more than 47 °C, which would cause thermal soft tissue injury. Therefore, thermal transfer to trans fixation pins was measured in vitro during the polymerisation phase of these polymers. We used trocar-pointed pins of different diameters that punctured one wall of a connecting tube, resulting in the tip of the trocar-pointed pin reaching the centre of the tube. The FLUKE® VT02 infrared digital camera was then used to measure heat transfer to the pins at 1 or 2 cm from poly(methyl methacrylate) or epoxy putty. The polymerisation temperatures of these polymers yield a potentially dangerous level of heat for soft and hard tissue. This was observed in almost all the experimental conditions tested. On the other hand, epoxy putty transfer to the pins did not cause the temperature to reach 47 °C at any time or in any of the setups examined. Poly(methyl methacrylate) did reach more than 47 °C and remained at that level for more than 1 min at 1 cm from the polymer. This acrylate exhibited polymerisation temperatures higher than epoxy and its heat transfer to the pins was potentially dangerous if used at less than 1 cm from soft or hard tissue.

Dysregulated mammalian target of rapamycin (mTOR) activity is associated with various neurodevelopmental disorders ranging from idiopathic autism spectrum disorders (ASD) to syndromes caused by single gene defects. This suggests that maintaining mTOR activity levels in a physiological range is essential for brain development and functioning. Upon activation, mTOR regulates a variety of cellular processes such as cell growth, autophagy, and metabolism. On a molecular level, however, the consequences of mTOR activation in the brain are not well understood. Low levels of cholesterol are associated with a wide variety of neurodevelopmental disorders. We here describe numerous genes of the sterol/cholesterol biosynthesis pathway to be transcriptionally regulated by mTOR complex 1 (mTORC1) signaling in vitro in primary neurons and in vivo in the developing cerebral cortex of the mouse. We find that these genes are shared targets of the transcription factors SREBP, SP1, and NF-Y. Prenatal as well as postnatal mTORC1 inhibition downregulated expression of these genes which directly translated into reduced cholesterol levels, pointing towards a substantial metabolic function of the mTORC1 signaling cascade. Altogether, our results indicate that mTORC1 is an essential transcriptional regulator of the expression of sterol/cholesterol biosynthesis genes in the developing brain. Altered expression of these genes may be an important factor contributing to the pathogenesis of neurodevelopmental disorders associated with dysregulated mTOR signaling.

Increasing numbers of studies seek to characterize the different cellular sub-populations present in mammalian tissues. The techniques “Isolation of Nuclei Tagged in Specific Cell Types” (INTACT) or “Fluorescence-Activated Nuclei Sorting” (FANS) are frequently used for isolating nuclei of specific cellular subtypes. These nuclei are then used for molecular characterization of the cellular sub-populations. Despite the increasing popularity of both techniques, little is known about their isolation efficiency, advantages, and disadvantages or downstream molecular effects. In our study, we compared the physical and molecular attributes of sfGFP+ nuclei isolated by the two methods—INTACT and FANS—from the neocortices of Arc-CreERT2 × CAG-Sun1/sfGFP animals. We identified differences in efficiency of sfGFP+ nuclei isolation, nuclear size as well as transcriptional (RNA-seq) and chromatin accessibility (ATAC-seq) states. Therefore, our study presents a comprehensive comparison between the two widely used nuclei sorting techniques, identifying the advantages and disadvantages for both INTACT and FANS. Our conclusions are summarized in a table to guide researchers in selecting the most suitable methodology for their individual experimental design.

INTRODUCTION: Prevalence of infection with HIV-1 non-B subtypes in Italy has been reported to raise, due to increased migration flows and travels. HIV-1 variants show different biological and immunological properties that impact on disease progression rate, response to antiretroviral therapy (ART) and sensitivity of diagnostic tests with important implications for public health. Therefore, a constant surveillance of the dynamics of HIV variants in Italy should be a high public health priority. Organization of surveillance studies requires building up a platform constituted of a network of clinical centers, laboratories and institutional agencies, able to properly collect samples for the investigation of HIV subtypes heterogeneity and to provide a database with reliable demographic, clinical, immunological and virological data. AIM: We here report our experience in building up such a platform, co-ordinated by the National AIDS Center of the Istituto Superiore di Sanita, taking advantage of a pilot study aimed at evaluating HIV subtypes diversity in populations of HIV-infected migrant people in Italy. MATERIALS AND METHODS: Four hundred and thirty four HIV-infected migrants were enrolled in 9 Italian clinical centers located throughout the Italian territory. Standard Operating Procedures (SOPs) for sample collection were provided by the National AIDS Center to each clinical center. In addition, clinical centers were required to fill up a case report form (crf) for each patient, which included demographic, clinical, immunological and virological information. RESULTS: All centers properly collected and stored samples from each enrolled individual. Overall, the required information was correctly provided for more than 90% of the patients. However, some fields of the crf, particularly those including information on the last HIV-negative antibody test and presence of co-infections, were properly filled up in less than 80% of the enrolled migrants. Centers from Northern and Central Italy showed a better tendency to report correct information in the crf than centers from the South. These results provide evidence that procedures for establishing a platform for the surveillance of HIV subtype heterogeneity are affordable by all the components of the network and lay the ground for the organization of a broader HIV subtypes surveillance in Italy.

Biomineralization is a process in which specialized cells secrete and deliver inorganic ions into confined spaces limited by organic matrices or scaffolds. Chicken eggshell is the fastest biomineralization system on earth, and therefore, it is a good experimental model for the study of biomineralization. Eggshell mineralization starts on specialized dispersed sites of the soft fibrillar eggshell membranes referred to as negatively charged keratan sulfate mammillae. However, the rest of the fibrillar eggshell membranes never mineralizes, although 21% of their amino acids are acidic. We hypothesized that, relative to the mammillae, the negatively charged amino acids of the fibrillar eggshell membranes are not competitive enough to promote calcite nucleation and growth. To test this hypothesis, we experimentally increased the number of negatively charged carboxylate groups on the eggshell membrane fibers and compared it with in vitro calcite deposition of isolated intact eggshell membranes. We conclude that the addition of poly-carboxylated groups onto eggshell membranes increases the number of surface nucleation sites but not the crystal size.

Biominerals fulfill various physiological functions in living organisms, however, pathological mineralization can also occur generating mineral pathologies such as the formation of calcium oxalate (CaOx) calculi in the urinary tract. Inspired by the ability of living organisms to generate biogenic minerals using biological organic matrices, and the need to understand the mechanisms of crystallization, three-dimensional fibrillary meshes based on chitosan fibers with random and controlled topology by electrospinning were manufactured. Chitosan was selected due to its active role on in vitro crystallization and its physicochemical properties, which allows the exposure of their functional chemical groups that could selectively stabilize hydrated crystalline forms of CaOx. CaOx crystals were generated on conductive tin indium oxide (ITO) glass substrates modified with electrospun chitosan fibers by using electrocrystallization (EC) technique. The chitosan fibers and the resulting CaOx crystals were analyzed by optical microscopy (OM), scanning electron microscopy (SEM), and X-ray diffraction (XRD) techniques, which demonstrated that the chemical nature and topology of the three-dimensional fibers used as organic template are key factors in the control of type, morphology, and crystallographic orientation of CaOx.

In this paper we discuss the formation of a Western visual culture about two Indigenous Fueguian societies, which linked the Shelk'nam/Haush with a pedestrian hunter ethos, and the Yamana/Yagan with a maritime hunter ethos. We analyse 513 Shelk'nam/Haush photographs and 428 Yámana/Yagán photographs and we compare them with information of 58 written texts about the Shelk'nam/Haush and 103 about the Yámana/Yagán and archaeological data from both societies. The comparison between both records allows us to discuss: a) the differential visibility of artefacts usually associated with a pedestrian hunter way of life -bows and arrows- and those associated to a maritime hunter way of life -harpoons- and b) the gender associated with both hunting activities. We consider that the visibility of these artefacts in visual and written culture is both associated to each Fueguian society in terms of their own idiosyncracy, as well as to the imaginary of Western voyagers who contacted them.

Category: Ankle, Hindfoot, Midfoot/Forefoot Introduction/Purpose: To evaluate the risk for non-union in patients who received Toradol in the perioperative period following osseous foot & ankle surgery.We propose there is ni significant difference in non-union rate between patients who received Toradol in the perioperative period following osseous surgery, compared to those the literature reports of using NSAIDs in the post operative period. Methods: Study Design: Random, Retrospective Chart Review of a single surgeon. 186 met the inclusion criteria with 172 complete charts available for review Procedure: Osseous foot and ankle surgery including osteotomies, fusions, and fracture repair. (1st MPJ fusions, Lapidus, Ankle, TTC) Inclusion Criteria: Undergo osseous surgery including osteotomies, fusions, or fracture repair Received Toradol in the perioperative period Complete chart with radiographs Outcomes: Radiographic and chart analysis for non-union between the initial post-operative visit and the final visit Results: A total of 186 patients were identified in having undergone a boney procedure and having received Toradol in the post - operative period. Out of the 186 patients, 172 charts were available for review. 165 of the 172 patients underwent unremarkable post operative healing. Seven patients (4.1%) were identified to have a clinical, radiographic or advanced imaging confirmed non- union. This was found to be not statistically significant with a p-value of < 0.005 Conclusion: Since the mainstream data available has been unable to draw a clear conclusion regarding NSAID use in bone surgery cases, our study aimed to present a large patient group that had no ill effects from its usage post operatively in osseous foot & ankle surgery. As the data demonstrates, there was no correlation that post operative use of potent NSAIDs increased the risk of non-union in the patient group.

Category: Bunion Introduction/Purpose: A 6-8 week non-weightbearing period post modified lapidus arthrodesis has traditionally been universally accepted. A review of the literature reports nonunion rates between 5-33% after modified lapidus with 6-8 weeks of non- weightbearing. There are only a few reports in the literature that discuss immediate weightbearing after the modified lapidus procedure. In this retrospective review, we examine the nonunion rate among patients undergoing the modified lapidus arthrodesis who were immediately weightbearing in a controlled ankle motion (CAM) boot. It is our hypothesis that the non- union rate will be comparable to the traditional post-operative protocol nonunion rate. Methods: In this retrospective study, we evaluated chart data on patients who underwent a modified Lapidus arthrodesis with immediate weight- bearing in a CAM boot. The goal of the study was to determine if a modified Lapidus surgical technique in conjunction with rigid internal fixation produces the necessary stability post-operatively in order to allow bony consolidation while being stressed with immediate weight bearing forces. Patients who underwent a modified Lapidus arthrodesis using either a 3 screw construct or a medially placed locking plate with an interfragmentary screw were included in the study. Patients with other adjunctive procedures that would prevent early weight bearing were not included in the investigation. Results: A total of 376 patients were identified with 74 patients meeting inclusion criteria. 4 patients had bilateral procedures performed at separate times for a total of 78 Lapidus procedures. 31 patients had a 3 screw construct while 43 patients had a medial locking plate with an interfragmentary screw. 15 patients admitted to using nicotine. Additionally, 7 patients had type II Diabetes Mellitus. Autogenous shear- strain relief bone graft was used in 75 of the 79 procedures.Three patients (3.8%) experienced a post-operative non-union. Interestingly, none of the patients with non-unions were smokers and only one patient was diabetic. Conclusion: The results of this study found a 3.8% nonunion rate. Based on these results we conclude that a modified Lapidus procedure using a long, solid interfragmentary screw with either additional screw support or a locking plate, we may permit patients to ambulate safely in a CAM boot immediately post- operative period without affecting surgical outcome.

Category: Ankle, Ankle Arthritis Introduction/Purpose: The purpose of this review is to present a case of post-traumatic ankle valgus and distal lateral tibial osteonecrosis successfully treated with staged deltoid repair, opening wedge tibial osteotomy, fibular lengthening, syndesmotic fusion and total ankle arthroplasty. Methods: Initial surgery consisted of ankle joint arthrotomy and deltoid imbrication. The second surgery consisted of a tibial opening wedge osteotomy with autogenous cortical fibular bone graft superior to the area of osteonecrosis to correct the 20 degree ankle valgus. Fibular lengthening osteotomy and fusion of the distal syndesmosis were also performed. CT scan confirmed bony consolidation at the distal tibiofibular syndesmosis as well as union of the allograft opening wedge. The final surgery was total ankle joint replacement with bone grafting of the area of osteonecrosis. Results: After 5 years of follow up the patient has progressed out of his AFO to full weightbearing. He reports no ankle pain, improved function and range of motion and is ambulating independently with no assistive devices. Conclusion: We successfully treated a case of distal lateral tibial osteonecrosis, and a 20 degree ankle valgus with staged deformity correction and ankle replacement. Radiographs demonstrate a well seated and positioned implant. We believe that with proper alignment that total ankle arthroplasty is a safe treatment option in the face of bone infarction.

A phosphorylated chitin (Chi-P) derivative was synthesized and its chemical structure was verified with Fourier-transform infrared spectroscopy (FTIR), elemental analysis, and thermogravimetric techniques (TGA). The influence of Chi-P used as a solid template through in vitro electrocrystallization (EC) supported on an indium zinc oxide (ITO) surface on the growth of calcium carbonate (CaCO3) was studied. CaCO3 crystals through EC essays were also compared with crystals obtained with the gas diffusion (GD) method. Scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDS), chronopotentiometry, Raman, and powder X-ray diffractometry (XRD) characterized all resultant inorganic particles. Our findings revealed that the EC method selectively controlled the coexistence of truncate calcite and the metastable phase of vaterite. The crystals’ morphology reflects the electrostatic interaction of phosphate moieties from Chi-P onto CaCO3 crystals through both EC and GD crystallization methods. We believe that the EC method represents a viable electrochemical approach for studying different inorganic minerals and could be useful as an in vitro classical crystallization method for the design of advanced inorganic materials with desirable shapes and properties.

In our crystallization experiments, the influence of alginate from Chilean Lessonia nigrescens and functionalized multi-walled carbon nanotubes (MWCNTs) was tested through electrocrystallization (EC) and gas diffusion (GD) methods on the crystal growth of calcium carbonate (CaCO3) and their possible stabilization of proto-structures in amorphous CaCO3 (ACC) state through pre-nucleation clusters (PNC) essays with automatic potentiometric titrations were performed. CaCO3 crystals obtained in the in vitro above-mentioned crystallization systems were characterized by scanning electron microscope (SEM), energy-dispersive X-ray spectrometry (EDS) and powder X-ray diffractometer (XRD). Our experimental findings showed that ALG and functionalized MWCNTs stabilized truncated and agglomerated vaterite-like particles through GD and EC methods. While, on the other hand, we obtained qualitative information about induction or inhibition of CaCO3 nucleation that was provided by potentiometric titrations.

In this paper we analyze two corpuses of photographs that document forms of violence experienced by the Indigenous Peoples of Tierra del Fuego and Pampa-Patagonia in the context of the advancing presence of Western agents (voyagers, militaries, missionaries, ethnographers) in their territories, between 1880 and 1950. We have identified a sample of 112 photos which show these situations (out of a corpus of 1865 photographs of Tierra del Fuego-Patagonia); these are analyzed using two complementary concepts:• photographed violence: photos which document violent situations; • violent photographs: photos in which the very act of taking a picture has been coercive, implying a praxis of body control over the photographed subject, against his/her will.Results show that there are scarce images of photographed violence, which document aggressions of Westerners against Indigenous Peoples, but not vice versa. Regarding violent photographs, the Pampa-Patagonian Indigenous Peoples have been represented as violent “savages” or as dominated “civilized” peoples, while the Fueguian Indigenous Peoples have been represented as the “transcultured otherness” (as religious propaganda), or as the “exotic otherness” (as subjects of scientific study). These trends contrast with those observed in the global corpus of photographs, which record numerous non-violent situations in which the cultural variability generated by the Indigenous' agency can be appreciated.

Aproximadamente un 5% de los melanomas malignos corresponden a localizaciones extracutáneas, 75-80% son melanomas oculares y los restantes 20-25% se localizan en las mucosas. Hay descritos melanomas en vulva, su localización más frecuente, vagina, conducto anal, fosas nasales, cavidad oral, senos paranasales, pene, esófago y bronquios. En la presente comunicación se realizan consideraciones clínicas e histopatológícas sobre el melanoma maligno en mucosas y se efectúa una breve reseña de cada una de las localizaciones. Se presentan siete casos, uno de melanoma de las fosas nasales, uno de melanoma de conducto anal y cinco de cavidad oral.