179 research outputs found
The Effect of Rare Earth Elements on Growth Performance, Tibia Mineralization and Blood Serum of Japanese Quails.
No full textThe present study was designed to determine the effect of different types and concentrations rare earth elements on growth performance of Japanese quails. 120 and 225 one day old Japanese quails in the first and third experiment respectively were allotted to five dietary treatments: a control group and four REE groups which were supplemented with 50,100, 400 and 800 mg/kg of REE-citrate, a Lanthanoid mixture. In the second experiment 300 one day old Japanese quails were allotted to eight dietary treatments: a control group and seven REE groups which were supplemented with 50 or 100 mg/kg of REE-citrate (type A), lanthanum acetate (type B), lanthanum chloride (type C) and lanthanum carbonate (type D). Each experiment lasted four weeks and during it feed and water was ad libitum.
The REE supplements increased the weight gain of Japanese quails compare to control group by 18.5-22% during the first experiment (p<0.05), by 2-6.4% during the second experiment and by 6% during the third experiment. The feed consumption and the feed conversion improvement were not significantly affected by REE in any of the three experiments. REE-citrate improved the feed conversion ratio by 4.6-15.5% and by 5.8-13.1% during the first and third experiments respectively. In the second experiment, the REE-type C at level of 50 mg/kg and REE-type D at level of 100 mg/kg, improved the feed conversion ratio by 1.7-2.6%. Also increasing the level of different types of REE from 50 to 100 mg/kg improved weight gain and feed conversion ratio in the second experiment.
In the first experiment, the low concentrations of REE-citrate (50 and 100 mg/kg) significantly increased phosphor content of tibia ash compare to that of other groups (p<0.05). Also the lowest concentrations of REE-citrate (50 mg/kg) significantly (p<0.05) increased tibia magnesium compare to control group and the high concentrations (400 and 800 mg/kg) of REE. In the second experiment, the calcium content of tibia ash of Japanese quails fed 50 mg/kg of REE type B or C was significantly (p<0.05) higher than that of quails fed 50 mg/kg of REE-type A. also the diet supplemented with 100 mg/kg of REE-type B, significantly (p<0.05) decreased the tibia calcium compare to control group. The phosphor content of tibia ash in Japanese quails fed REE-type A was significantly lower than that in quails fed types B, C and D of REE. In the third experiment, the highest concentration of REE-citrate (800 mg/kg) significantly decreased magnesium content of tibia ash compare to other experimental groups including control group (p<0.01, p<0.001). In the first experiment, the lowest concentration of REE-citrate (50 mg/kg) increased calcium content of blood serum compare to control group and significantly (p<0.05) compare to high concentrations (400 and 800 mg/kg) of REE-citrate. Also the Japanese quails fed 400 mg/kg of REE-citrate had significantly (p<0.05) higher magnesium in their blood serum than the quails of other groups. In the second experiment, the diet supplemented with 100 mg/kg of REE-type C significantly (p<0.05) increased serum calcium compare to diets with 100 mg/kg of other types of REE supplements.
Based on the results of present study, the optimum concentration range of REE-citrate for improving both growth and tibia mineralization was 50-100 mg/kg of feed. However the diet with 400 mg/kg of REE-citrate also improved growth performance and tibia minerals in experiment 3. Comparison between different rare earth elements showed that Lanthanum salts especially lanthanum-chloride had better effect on growth and tibia mineralization than REE-citrate which was a mixture. The optimum concentration of lanthanum salts for increasing growth performance was 100 mg/kg of feed and for improving bone mineralization was 100 mg/kg of feed
Effect of C60 Fullerene on the Duplex Formation of i-Motif DNA with Complementary DNA in Solution
No full textThe structural effects of fullerene on i-motif DNA were investigated by characterizing the structures of fullerene-free and fullerene-bound i-motif DNA. in the presence of cDNA and in solutions of varying pH, using circular dichroism and synchrotron small-angle X-ray scattering. To facilitate a direct structural comparison between the i-motif and duplex structures in response to pH stimulus, we developed atomic scale structural models for the duplex and i-motif DNA structures, and for the C-60/i-motif DNA hybrid associated with the cDNA strand, assuming that the DNA strands are present in an ideal right-handed helical conformation. We found that fullerene shifted the pH-induced conformational transition between the i-motif and the duplex structure, possibly due to the hydrophobic interactions between the terminal fullerenes and between the terminal fullerenes and an internal TAA loop in the DNA strand. The hybrid structure showed a dramatic reduction in cyclic hysteresis.X111716sciescopu
Assessing whether the 2017 <i>M</i> <sub>w</sub> 5.4 Pohang earthquake in South Korea was an induced event
No full textTriggering quakes in a geothermal space
Enhanced geothermal systems (EGSs) provide a potentially clean and abundant energy source. However, two magnitude-5 earthquakes recently occurred in South Korea during EGS site development. Grigoli
et al.
and Kim
et al.
present seismic and geophysical evidence that may implicate the second of these earthquakes, which occurred in Pohang, as an induced event. The combination of data from a local seismometer network, well logs, satellite observations, teleseismic waveform analysis, and stress modeling leads to the assessment that the earthquake was probably or almost certainly anthropogenically induced. The possibility remains that the earthquake occurred coincidentally at the EGS site location, but the aftershock distribution and other lines of evidence are concerning for future development of this geothermal resource.
Science
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1007
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Bispecific anti-mPDGFR beta x cotinine scFv-C-kappa-scFv fusion protein and cotinine-duocarmycin can form antibody-drug conjugate-like complexes that exert cytotoxicity against mPDGFR beta expressing cells
No full textAntibody selection for antibody-drug conjugates (ADCs) has traditionally depended on its internalization into the target cell, although ADC efficacy also relies on recycling of the receptor-ADC complex, endo-lysosomal trafficking, and subsequent linker/antibody proteolysis. In this study, we observed that a bispecific anti-murine platelet-derived growth factor receptor beta (mPDGFR beta) x cotinine single-chain variable fragment (scFv)-kappa constant region (C-kappa)-scFv fusion protein and cotinine-duocarmycin can form an ADC-like complex to induce cytotoxicity against rnPDGFR beta expressing cells. Multiple anti-mPDGFR beta antibody candidates can be produced in this bispecific scFv-C-kappa-scFv fusion protein format and tested for their ability to deliver cotinine-conjugated cytotoxic drugs, thus providing an improved approach for antibody selection in ADC development.N
Un retrato de Carmen: Orgullosamente kichwa de Saraguro
No full textIn this work, the author relies on the qualitative portraiture framework and on more than four months of communication to draw Carmen\u27s reality, a Kichwa woman from Saraguro, Ecuador, living in Maryland, the United States. The results of this study draw a little-known reality about Carmen as a trilingual Kichwa immigrant woman who, in turn, is a matriarch of her family, university student, defender, and educator of her children in schools and at home, as well as a bridge of indigenous cultural knowledge for the new generation within their home.En este trabajo, el autor se apoya en el marco cualitativo de retrato y en más de cuatro meses de comunicación para dibujar la realidad de Carmen, una mujer kichwa de Saraguro, Ecuador residente en Maryland, Estados Unidos. Los resultados de este estudio dibujan una realidad poco conocida sobre Carmen como mujer trilingüe inmigrante kichwa que, a su vez, es matriarca de su familia, estudiante universitaria, defensora y educadora de sus hijos en las escuelas y en su casa, al igual que puente de conocimiento cultural indígena para la nueva generación dentro de su hogar.  
Scoping study with geostatistical simulation to assess exploration targets for rare earth elements (REE) in the Antioquia department, Colombia
No full textilustraciones, diagramas, mapas, tablasLos estudios conceptuales son generalmente la primera valoración económica de un proyecto minero. Bajo este contexto, el objetivo principal de este trabajo es formular un estudio técnico y económico de la viabilidad potencial de los recursos minerales de elementos de tierras raras (Rare Earth Elements, REE) en el departamento de Antioquia mediante la simulación geoestadística por bandas rotantes del tenor de óxidos totales de tierras raras (Total Rare Earth Oxides, TREO) y el análisis de los factores modificadores, para valorar un programa de prospección detallada en los blancos o targets de exploración. Los datos del tenor de REE en Antioquia se construyeron durante el 2004-2007 en el proyecto “Mapa geoquímico del departamento de Antioquia”. El tenor de TREO se procesó mediante las herramientas computacionales Isatis, ArcMap, QGIS y geoportales de la Agencia Nacional de Minería (ANM) y del Servicio Geológico Colombiano (SGC). Se obtuvo dos targets con potencial de prospectividad para desarrollar la cadena de valor de REE en las subregiones del Nordeste y Bajo Cauca, con una estimación de recursos inferidos de 5,444 millones de toneladas a un tenor de 0.09% de TREO, equivalentes a 4.9 millones de toneladas de TREO. Para materializar un negocio minero de REE en Antioquia se requiere inicialmente la inversión de un programa técnico de prospección detallada sobre un área de 2,150 km2, presupuestado en 1.84 MUSD. (Texto tomado de la fuente)Scoping studies are generally the first economic appraisal of a mining project. Under this context, the main objective this work is to formulate a technical and economic study of the potential viability of mineral resources of REE in the Antioquia department through geostatistical simulation by turning bands of total rare earth oxides (TREO) grade and analysis of the modifying factors, to assess a detailed prospecting program in exploration targets. REE grade data in Antioquia were constructed during 2004-2007 in the project "Geochemical Map of the Antioquia Department". The TREO grade was processed using the computational tools Isatis, ArcMap, QGIS, and National Mining Agency (ANM) and the Colombian Geological Service (SGC) geoportals. Two targets with prospectivity potential were obtained to develop REE's value chain in Nordeste and Bajo Cauca subregions, with an inferred resource estimate of 5,444 million tons with TREO grade of 0.09%, equivalent to 4.9 million tons of TREO. To materialize a REE mining business in Antioquia, the investment of a technical program of detailed prospecting is initially required over an area of 2,150 km2, budgeted at 1.84 MUSD.MaestríaMagíster en Ingeniería - Recursos MineralesÁrea Curricular de Recursos Minerale
Use of Phosphate Solubilizing Bacteria to Leach Rare Earth Elements from Monazite-Bearing Ore
No full textIn the present study, the feasibility to use phosphate solubilizing bacteria (PSB) to develop a biological leaching process of rare earth elements (REE) from monazite-bearing ore was determined. To predict the REE leaching capacity of bacteria, the phosphate solubilizing abilities of 10 species of PSB were determined by halo zone formation on Reyes minimal agar media supplemented with bromo cresol green together with a phosphate solubilization test in Reyes minimal liquid media as the screening studies. Calcium phosphate was used as a model mineral phosphate. Among the test PSB strains, Pseudomonas fluorescens, P. putida, P. rhizosphaerae, Mesorhizobium ciceri, Bacillus megaterium, and Acetobacter aceti formed halo zones, with the zone of A. aceti being the widest. In the phosphate solubilization test in liquid media, Azospirillum lipoferum, P. rhizosphaerae, B. megaterium, and A. aceti caused the leaching of 6.4%, 6.9%, 7.5%, and 32.5% of calcium, respectively. When PSB were used to leach REE from monazite-bearing ore, ~5.7 mg/L of cerium (0.13% of leaching efficiency) and ~2.8 mg/L of lanthanum (0.11%) were leached by A. aceti, and Azospirillum brasilense, A. lipoferum, P. rhizosphaerae and M. ciceri leached 0.5–1 mg/L of both cerium and lanthanum (0.005%–0.01%), as measured by concentrations in the leaching liquor. These results indicate that determination of halo zone formation was found as a useful method to select high-capacity bacteria in REE leaching. However, as the leaching efficiency determined in our experiments was low, even in the presence of A. aceti, further studies are now underway to enhance leaching efficiency by selecting other microorganisms based on halo zone formation
Specific ablation of PDGFRβ-overexpressing pericytes with antibody-drug conjugate potently inhibits pathologic ocular neovascularization in mouse models
No full textBACKGROUND: Crosstalk between pericytes and endothelial cells is critical for ocular neovascularization. Endothelial cells secrete platelet-derived growth factor (PDGF)-BB and recruit PDGF receptor β (PDGFRβ)–overexpressing pericytes, which in turn cover and stabilize neovessels, independent of vascular endothelial growth factor (VEGF). Therapeutic agents inhibiting PDGF-BB/PDGFRβ signaling were tested in clinical trials but failed to provide additional benefits over anti-VEGF agents. We tested whether an antibody-drug conjugate (ADC) – an engineered monoclonal antibody linked to a cytotoxic agent - could selectively ablate pericytes and suppress retinal and choroidal neovascularization. METHODS: Immunoblotting, flow cytometry, cell viability test, and confocal microscopy were conducted to assess the internalization and cytotoxic effect of ADC targeting mPDGFRβ in an in vitro setting. Immunofluorescence staining of whole-mount retinas and retinal pigment epithelium-choroid-scleral complexes, electroretinography, and OptoMotry test were used to evaluate the effect and safety of ADC targeting mPDGFRβ in the mouse models of pathologic ocular neovascularization. RESULTS: ADC targeting mPDGFRβ is effectively internalized into mouse brain vascular pericytes and showed significant cytotoxicity compared with the control ADC. We also show that specific ablation of PDGFRβ-overexpressing pericytes using an ADC potently inhibits pathologic ocular neovascularization in mouse models of oxygen-induced retinopathy and laser-induced choroidal neovascularization, while not provoking generalized retinal toxicity. CONCLUSION: Our results suggest that removing PDGFRβ-expressing pericytes by an ADC targeting PDGFRβ could be a potential therapeutic strategy for pathologic ocular neovascularization
Anhydrous Alum Inhibits α-MSH-Induced Melanogenesis by Down-Regulating MITF via Dual Modulation of CREB and ERK
No full textMelanogenesis, the intricate process of melanin synthesis, is central to skin pigmentation and photoprotection and is regulated by various signaling pathways and transcription factors. To develop potential skin-whitening agents, we used B16F1 melanoma cells to investigate the inhibitory effects of anhydrous alum on melanogenesis and its underlying molecular mechanisms. Anhydrous alum (KAl(SO4)2) with high purity (>99%), which is generated through the heat-treatment of hydrated alum (KAl(SO4)2·12H2O) at 400 °C, potentiates a significant reduction in melanin content without cytotoxicity. Anhydrous alum downregulates the master regulator of melanogenesis, microphthalmia-associated transcription factor (MITF), which targets key genes involved in melanogenesis, thereby inhibiting α-melanocyte-stimulating hormone (α-MSH)-induced melanogenesis. Phosphorylation of the cAMP response element-binding protein, which acts as a co-activator of MITF gene expression, is attenuated by anhydrous alum, resulting in compromised MITF transcription. Notably, anhydrous alum promoted extracellular signal-regulated kinase phosphorylation, leading to the impaired nuclear localization of MITF. Overall, these results demonstrated the generation and mode of action of anhydrous alum in B16F1 cells, which constitutes a promising option for cosmetic or therapeutic use
Educación Intercultural Bilingüe en el Ecuador (1989-2007): Voces
No full textAt this precise moment when the restitution of bilingual intercultural education to management by indigenous nationalities is being debated, the book Bilingual Intercultural Education in Ecuador (1989-2007). Voces, by Alexis Oviedo, is a valuable and timely contribution. Those who seek to understand the concrete realities of intercultural bilingual education (IBE) in its historical development will find in this book a useful and relevant report that arises from the epistemic dialogue between the author and some protagonists of the IBE implementation process in different times.En este preciso momento en que se debate la restitución de la educación intercultural bilingüe a la gestión por las nacionalidades indígenas, el libro Educación Intercultural Bilingüe en Ecuador (1989-2007). Voces, de Alexis Oviedo, constituye una valiosa y oportuna contribución. Aquellos-as que buscan entender las realidades concretas de la educación intercultural bilingüe (EIB) en su devenir histórico, encontrarán en este libro un informe útil y relevante que surge del diálogo epistémico entre el autor y algunos protagonistas del proceso de implementación de la EIB en distintos momentos
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