1,147 research outputs found

    Assessing Instrumental Weapons Violence against Teachers

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    Violence against teachers is a critical issue for learning communities. Among the most serious forms of harm include weapon violence. While there has been extensive research on weapon carrying and traditional weapon use within schools, there has been little investigation into instrumental weapon violence against teachers. The current study utilizes qualitative survey data to investigate contributing conditions related to teacher’s experiences of instrumental weapon’s violence through direct content analysis. Results from this study aim to expand our understanding of the nature and nuance of teacher-directed instrumental weapon violence

    Measurement of cooling and warming rates in vitrification-based plant cryopreservation protocols

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    Cryopreservation protocols include the use of additives and pre-treatments aimed to reduce the probability of ice nucleation at all temperatures, mainly through micro-viscosity increase. Still, there is a risk of ice formation in the temperature region comprised between the equilibrium freezing (Tf) and the glass transition (TG) temperatures. Consequently, fast cooling and warming, especially in this region, is a must to avoid ice-derived damage. Vitrification and droplet-vitrification techniques, frequently used cryopreservation protocols based in fast cooling, were studied, alongside with the corresponding warming procedures. A very fast data acquisition system, able to read very low temperatures, down to that of liquid nitrogen, was employed. Cooling rates, measured between -20 and -120 ºC, ranged from ca. 5 ºC s-1 to 400 ºC s-1, while warming rates spanned from ca. 2 ºC s-1 to 280 ºC s-1, for the different protocols and conditions studied. A wider measuring window (0 ºC to -150 ºC) produced lower rates for all cases. The cooling and warming rates were also related to the survival observed after the different procedures. Those protocols with the faster rates yielded the highest survival percentages.Centro de Investigación y Desarrollo en Criotecnología de Alimento

    Covalently Labeled Fluorescent Exosomes for In Vitro and In Vivo Applications.

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    The vertiginous increase in the use of extracellular vesicles and especially exosomes for therapeutic applications highlights the necessity of advanced techniques for gaining a deeper knowledge of their pharmacological properties. Herein, we report a novel chemical approach for the robust attachment of commercial fluorescent dyes to the exosome surface with covalent binding. The applicability of the methodology was tested on milk and cancer cell-derived exosomes (from U87 and B16F10 cancer cells). We demonstrated that fluorescent labeling did not modify the original physicochemical properties of exosomes. We tested this nanoprobe in cell cultures and healthy mice to validate its use for in vitro and in vivo applications. We confirmed that these fluorescently labeled exosomes could be successfully visualized with optical imaging.This study was supported by the Comunidad de Madrid, projects: “Y2018/NMT-4949 (NanoLiver-CM)” and “S2017/BMD-3867 (RENIM-CM)”; it was also co-funded by the European Structural and Investment Fund. The CNIC is supported by the Instituto de Salud Carlos III (ISCIII), the Ministerio de Ciencia e Innovación (MCIN), and the Pro CNIC Foundation, and it is a Severo Ochoa Center of Excellence (SEV-2015-0505). JV was supported by grants from Instituto de Salud Carlos III (PI18/01833), co-funded by European Regional Development Fund (ERDF) and from Comunidad de Madrid, project “S2017/BMD2737 (ExoHep-CM)”, co-funded by European Structural and Investment Fund. A. Santos-Coquillat is grateful for the financial support from Ministerio de Ciencia e Innovación, Instituto de Salud Carlos III Sara Borrell Fellowship grant CD19/00136.S

    Measurement of cooling and warming rates in vitrification-based plant cryopreservation protocols

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    Cryopreservation protocols include the use of additives and pre-treatments aimed to reduce the probability of ice nucleation at all temperatures, mainly through micro-viscosity increase. Still, there is a risk of ice formation in the temperature region comprised between the equilibrium freezing (Tf) and the glass transition (TG) temperatures. Consequently, fast cooling and warming, especially in this region, is a must to avoid ice-derived damage. Vitrification and droplet-vitrification techniques, frequently used cryopreservation protocols based in fast cooling, were studied, alongside with the corresponding warming procedures. A very fast data acquisition system, able to read very low temperatures, down to that of liquid nitrogen, was employed. Cooling rates, measured between -20 and -120 ºC, ranged from ca. 5 ºC s-1 to 400 ºC s-1, while warming rates spanned from ca. 2 ºC s-1 to 280 ºC s-1, for the different protocols and conditions studied. A wider measuring window (0 ºC to -150 ºC) produced lower rates for all cases. The cooling and warming rates were also related to the survival observed after the different procedures. Those protocols with the faster rates yielded the highest survival percentages.Fil: Schneider Teixeira, Aline. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Centro de Investigaciones En Criotecnología de Alimentos (i); Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; Argentina. Instituto de Ciencia y Tecnología de Alimentos y Nutrición; EspañaFil: Gonzalez Benito, M. Elena. Universidad Politecnica de Madrid; EspañaFil: Molina García, Antonio D.. Consejo Superior de Investigaciones Científicas. Instituto de Ciencia y Tecnologia de Alimentos y Nutrición; Españ

    Modelización del crecimiento de alevines de Cichlasoma festae (Cichlidae) con tecnología Biofloc (BFT)

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    Aquaculture favors food sovereignty in Equator, maintains their livelihoods and boosts household unit incomes. The freshwater species Cichlasoma festae represents an important species of great local use. In this study, our objective was to model fry growth in Cichlasomafestae, produced in intensive systems with Biobloc technology. The study lasted 90 days and was carried out in the experimental farm “La María”, in Quevedo Local Technical University (UTEQ). 15 cages were placed inside a reinforced concrete circular pond with Biobloc and 300fries from C. festae with a weight of 4,9g were introduced. Individual biometric parameters of total length, weight and height were fortnightly measured in 75 fries from C. festae. Physicochemical parameters of Biobloc water (PH, temperature, oxygen, total ammoniacal nitrogen and suspended solids) were daily measured. Growth was determined using regression models and in a second stage the weight was adjusted to the best fit selected model, which was: Log-Y Square root-X which explains the 98,3% of the variability in weight. We may conclude with this study that Biobloc technology could be an alternative for intensive native species production. In future research, it will be necessary to advance in the knowledge of Biobloc conditions for each species, production biomass, aeration strategies for each growth stages and thus boost and optimize farming.La acuicultura favorece la soberanía alimentaria en Ecuador, mantiene sus medios de vida y potencia el incremento de los ingresos de la unidad familiar. La especie de agua dulce Cichlasoma festae representa una importante especie de gran uso local. En este estudio nuestro objetivo fue modelizar el crecimiento de alevines de Cichlasoma festae producidos en sistemas intensivos con tecnología Biofloc. El estudio duró 90 días y se llevó a cabo en la Finca experimental “La María”, en la Universidad Técnica Estatal de Quevedo (UTEQ). Se situaron 15 jaulas dentro de un estanque circular de hormigón armado con Biofloc y se introdujeron 300 alevines de C. festae con un peso de 4,9 g. Quincenalmente, se midieron en 75 alevines de C. festae los parámetros biométricos individuales de longitud total, peso y altura. Diariamente se midieron los parámetros fisicoquímicos del agua de Biofloc (pH, temperatura, oxígeno, nitrógeno amoniacal total y sólidos en suspensión). El crecimiento se determinó utilizando modelos de regresión y en una segunda etapa se ajustó el peso al modelo seleccionado de mejor ajuste que fue: Log-Y Raíz Cuadrada-X que explica el 98,3% de la variabilidad en Peso. Con este estudio  podemos concluir que la tecnología Biofloc podría ser una alternativa para la producción intensiva de especies nativas. En investigaciones futuras será necesario avanzar en el conocimiento de las condiciones del Biofloc propias para cada especie, biomasa de cultivo, estrategias de aireación para cada una de las etapas de crecimiento y así potenciar y optimizar los cultivos

    Osteoarticular Expression of Musashi-1 in an Experimental Model of Arthritis

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    Background. Collagen-induced arthritis (CIA), a murine experimental disease model induced by immunization with type II collagen (CII), is used to evaluate novel therapeutic strategies for rheumatoid arthritis. Adult stem cell marker Musashi-1 (Msi1) plays an important role in regulating the maintenance and differentiation of stem/precursor cells. The objectives of this investigation were to perform a morphological study of the experimental CIA model, evaluate the effect of TNFα-blocker (etanercept) treatment, and determine the immunohistochemical expression of Msi1 protein. Methods. CIA was induced in 50 male DBA1/J mice for analyses of tissue and serum cytokine; clinical and morphological lesions in limbs; and immunohistochemical expression of Msi1. Results. Clinically, TNFα-blocker treatment attenuated CIA on day 32 after immunization (). Msi1 protein expression was significantly higher in joints damaged by CIA than in those with no lesions () and was related to the severity of the lesions (Spearman’s rho = 0.775, ). Conclusions. Treatment with etanercept attenuates osteoarticular lesions in the murine CIA model. Osteoarticular expression of Msi1 protein is increased in joints with CIA-induced lesion and absent in nonlesioned joints, suggesting that this protein is expressed when the lesion is produced in order to favor tissue repair.This investigation was partially supported by Research Group #CTS-138 (Junta de Andalucía, Spain)

    Synergistic Antimicrobial Effects of Silver/Transition-metal Combinatorial Treatments

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    Due to the emergence of multi-drug resistant strains, development of novel antibiotics has become a critical issue. One promising approach is the use of transition metals, since they exhibit rapid and significant toxicity, at low concentrations, in prokaryotic cells. Nevertheless, one main drawback of transition metals is their toxicity in eukaryotic cells. Here, we show that the barriers to use them as therapeutic agents could be mitigated by combining them with silver. We demonstrate that synergism of combinatorial treatments (Silver/transition metals, including Zn, Co, Cd, Ni, and Cu) increases up to 8-fold their antimicrobial effect, when compared to their individual effects, against E. coli and B. subtilis. We find that most combinatorial treatments exhibit synergistic antimicrobial effects at low/ non-toxic concentrations to human keratinocyte cells, blast and melanoma rat cell lines. Moreover, we show that silver/(Cu, Ni, and Zn) increase prokaryotic cell permeability at sub-inhibitory concentrations, demonstrating this to be a possible mechanism of the synergistic behavior. Together, these results suggest that these combinatorial treatments will play an important role in the future development of antimicrobial agents and treatments against infections. In specific, the cytotoxicity experiments show that the combinations have great potential in the treatment of topical infections

    Analytical Evaluation of Dried Blood Spot and Rapid Diagnostic Test as a New Strategy for Serological Community Screening for Chronic Chagas Disease

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    Trypanosoma cruzi; Mancha de sangre seca (DBS); Cribado serológicoTrypanosoma cruzi; Taca de sang seca (DBS); Cribratge serològicTrypanosoma cruzi; Dried blood spot (DBS); Serological screeningBackground: Chagas disease is a public health problem not only in Latin America, but also in other regions, including Spain, due to migration movements. Conventional serological diagnosis requires an invasive sample (plasma or serum) and a well-equipped laboratory. To circumvent those limitations, blood samples dried on filter paper (DBS) or Rapid Diagnostic Test (RDT) could be a practical alternative to reference protocol for serological screening in epidemiological studies. We evaluated the usefulness of dried blood sampling and a rapid diagnostic test (Trypanosoma Detect™) for the detection of antibodies against T. cruzi for their use in community-based screening. Methodology/Principal Findings: A total of 162 stored paired whole-blood and serum samples from Latin American migrants and 25 negative-control blood samples were included. Diagnosis of chronic Chagas disease was performed in serum according to WHO algorithms. Blood samples were retrospectively collected as dried spots and then analyzed using two different serological techniques, enzyme-linked immunosorbent assay (ELISA) and electrochemiluminescence immunoassay (E-CLIA). Whole-blood samples were also used to evaluate a rapid diagnostic test based on immunochromatography. A better correlation with conventional serum was observed in dried blood elutes using E-CLIA than ELISA (97% vs. 77% sensitivity, respectively). Both assays reported 100% specificity. The median cut-off index values of E-CLIA for dried blood were significantly lower than those for serum (138.1 vs. 243.3, P<0.05). The Trypanosoma Detect™ test presented a sensitivity and specificity of 89.6% and 100%, respectively. Conclusions: The detection of antibodies against T. cruzi in dried blood samples shows a higher sensitivity when using E-CLIA compared with ELISA. Trypanosoma Detect™ is easier to use but has a lower sensitivity. Hence, we propose a sequential strategy based on performing the rapid test first, and a negative result will be confirmed by DBS-ECLIA for use in community Chagas disease screening programs.This work has been supported by the Fundació la Marató TV3 (project number 20182610)

    Robust spin crossover platforms with synchronized spin switch and polymer phase transition

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    The idea of developing magnetic molecular materials into real functional electronic devices with low-cost and scalable techniques appeared with the emergence of the field several years ago. Today, even though great advances have been done with this aim, the promise of a functional device working at the micro-/nanoscale and at room temperature has unfortunately not completely materialized yet, as their use still strongly depends on the fabrication methodology of a robust device that can be handled and integrated without compromising their functionality. Here we propose the use of polymeric matrices as a platform for the development of such robust switchable structures exhibiting reproducible results independently of the dimension-from macro to micro-/nanoscale-and morphology-from thin-films to nanoparticles and nanoimprinted motives-while allowing to induce an irreversible hysteresis, reminiscent of a non-volatile memory, by synchronization with the polymer phase transition

    Genetic analyses of aplastic anemia and idiopathic pulmonary fibrosis patients with short telomeres, possible implication of DNA-repair genes

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    Background: Telomeres are nucleoprotein structures present at the terminal region of the chromosomes. Mutations in genes coding for proteins involved in telomere maintenance are causative of a number of disorders known as telomeropathies. The genetic origin of these diseases is heterogeneous and has not been determined for a significant proportion of patients. Methods: This article describes the genetic characterization of a cohort of patients. Telomere length was determined by Southern blot and quantitative PCR. Nucleotide variants were analyzed either by high-resolution melting analysis and Sanger sequencing of selected exons or by massive sequencing of a panel of genes. Results: Forty-seven patients with telomere length below the 10% of normal population, affected with three telomeropathies: dyskeratosis congenita (4), aplastic anemia (22) or pulmonary fibrosis (21) were analyzed. Eighteen of these patients presented known pathogenic or novel possibly pathogenic variants in the telomere-related genes TERT, TERC, RTEL1, CTC1 and ACD. In addition, the analyses of a panel of 188 genes related to haematological disorders indicated that a relevant proportion of the patients (up to 35%) presented rare variants in genes related to DNA repair or in genes coding for proteins involved in the resolution of complex DNA structures, that participate in telomere replication. Mutations in some of these genes are causative of several syndromes previously associated to telomere shortening
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