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This paper deals with the thermodynamics of hydrometallurgical processes used in phosphate rock treatment. The stability of precipitated phases at different pH levels and molar concentrations in solutions containing phosphorus and calcium ions is analysed. The thermodynamic analysis was carried out by generating Pourbaix diagrams, species distribution diagrams and speciation diagrams using the Hydramedusa software. In addition, a XRD and SEM characterization of the different types of calcium phosphate found was performed to corroborate the thermodynamic results at different levels of pH and ion concentration. From this study, it was determined that hydroxyapatite and monetite can be obtained by hydrometallurgical processes with variations in pH and ionic concentrations of PO43- and Ca+, directly from the acid leach of phosphate rock.

La deficiencia de vitamina D representa una de las condiciones carenciales más comunes a nivel mundial, afectando a millones de personas en todos los grupos etarios y en múltiples contextos clínicos. A pesar de su alta prevalencia, continúa siendo subdiagnosticada y subtratada, en parte debido a su curso silencioso, a la escasa incorporación de su tamizaje en la práctica médica rutinaria y a la persistente percepción de que sus consecuencias clínicas se limitan al metabolismo óseo. Esta mirada reduccionista ha contribuido a que se desaproveche una herramienta terapéutica segura, accesible y con amplio potencial preventivo y pronóstico en distintas enfermedades crónicas.Durante décadas, el déficit de vitamina D estuvo principalmente vinculado al raquitismo infantil y a la osteomalacia en adultos, sin embargo, avances en la investigación han demostrado que la vitamina D posee receptores en múltiples tejidos, ejerciendo funciones endocrinas, paracrinas e inmunomoduladoras que trascienden su rol en la homeostasis del calcio y el fósforo. Actualmente, se reconoce que niveles bajos de 25-hidroxivitamina D están asociados no solo a fragilidad ósea, caídas y fracturas, sino también a sarcopenia, debilidad muscular, alteraciones inmunológicas, disfunción metabólica, neurocognitiva y emocional, entre otros desenlaces adversos.

To determine the surface microhardness of white portland cement associated with niobium nanoparticles, white portland cement associated with zirconium nanoparticles, and mineral trioxide aggregate. The present study is an experimental in-vitro study. The sample consisted of 03 study groups. These were divided into 09 subgroups of 04 hours, 14 days and 28 days. The instrument used to record the surface mechanical microhardness was the Vickers microdurometer. The Shapiro-Wilk statistical analysis was then performed to identify the normality of the data. The Anova test was applied to compare between the three groups and then the Tukey test for multiple comparisons with a 95% confidence level. White Portland cement associated with zirconium nanoparticles had the highest hardness value (p<0.05), followed by white Portland cement associated with niobium nanoparticles and aggregate control cement of mineral trioxide. The lowest value of surface microhardness was obtained by the addition of mineral trioxide (p<0.05). Surface microhardness values were significantly higher at 28 days than at 04 hours for all groups evaluated. White Portland cement with/without nanoparticulate additives generated higher surface microhardness than the control group added mineral trioxide in the evaluation periods. Determinar la microdureza superficial de cemento portland blanco asociado a nanopartículas de niobio, cemento portland blanco asociado a nanopartículas de circonio y agregado de trióxido mineral. El presente estudio es un estudio experimental in vitro. La muestra estuvo compuesta por 03 grupos de estudio. Estos se dividieron en 09 subgrupos de 04 horas, 14 días y 28 días. El instrumento utilizado para registrar la microdureza mecánica de la superficie fue el microdurómetro Vickers. Luego se realizó el análisis estadístico Shapiro-Wilk para identificar la normalidad de los datos. Se aplicó la prueba de Anova para comparar entre los tres grupos y luego la prueba de Tukey para comparaciones múltiples con un nivel de confianza del 95%. El cemento Portland blanco asociado a nanopartículas de circonio tuvo el mayor valor de dureza (p<0.05), seguido del cemento Portland blanco asociado a nanopartículas de niobio y el cemento de control de agregados de trióxido mineral. El valor más bajo de microdureza superficial se obtuvo mediante la adición de trióxido mineral (p<0,05). Los valores de microdureza superficial fueron significativamente mayores a los 28 días que a las 04 horas para todos los grupos evaluados. El cemento Portland blanco con/sin aditivos nanoparticulados generó mayor microdureza superficial que el grupo control al que se le añadió trióxido mineral en los periodos de evaluación.

The morphology of iron and agglomeration behaviour in the reduction progress of iron oxide fines were investigated in terms of isothermal reduction at 800 °C in an atmosphere of CO and H2. Agglomeration index was employed to evaluate the agglomeration behaviour during reduction. Sticking and agglomeration occurred regardless of the iron oxides and reducing atmosphere. Reduction by CO showed a higher tendency for sticking due to the formation of iron whiskers. The addition of CaO and MgO to Fe2O3 in sintering process could improve the reduction, and also decrease the sticking by forming calcio/magnesio-wustite on the surface. Iron whiskers were still formed with the addition of CaO and MgO, and the shape of whiskers were different from that of pure Fe2O3. Uniform coating layer on the surface of particles might be one of the important factors affecting the decrease in sticking between particles.

The biggest challenge in root canal treatment is the elimination of microorganisms; therefore, new techniques are continually sought to achieve success. The agar diffusion method was used to determine the antibacterial and antifungal effect of ozonated Sacha Inchi essential oil, calcium hydroxide paste, and the combination of both. Brain heart infusion and sabouraud agar were the culture media for Enterococcus faecalis and Candida albicans respectively. The antibacterial and antifungal effects were determined using the inhibition halos that formed around the wells containing the drugs at 24 hours and 48 hours. From the study, the antibacterial and antifungal effects of the ozonized oil was greater after 6 hours, proportional to the higher concentration of peroxide. This study showed that the antibacterial effect of ozonated Sacha Inchi oil is superior to that of calcium hydroxide and the combination of both substances.

Background: Stunting remains a persistent public health problem in Indonesia, particularly in rural areas. Objective: To examine the association between nutrient intake and breastfeeding practices with stunting and motor development among children aged 6–24 months in rural Indonesia. Methods: An unmatched case–control study was conducted involving 70 stunted and 70 non-stunted children. Nutrient intake was assessed using a single 24-hour dietary recall and compared with age-specific Recommended Dietary Allowances. Stunting was defined as height-for-age z-score (HAZ) < −2 SD based on WHO standards. Motor development was assessed using a standardized screening tool. Associations were analyzed using chi-square tests and multivariable logistic regression. Sensitivity analysis excluding low birth weight infants was also performed. Statistical significance was set at p < 0.05. Results: In bivariate analysis, inadequate calcium intake showed the strongest association with stunting (OR = 4.76; 95% CI: 2.33–9.72), followed by inadequate energy and protein intake. In multivariable analysis, inadequate calcium intake remained independently associated with stunting (aOR = 12.01; 95% CI: 3.23–44.60; p < 0.001). Sensitivity analysis excluding low birth weight infants attenuated the estimate but the association remained significant (aOR = 8.4; 95% CI: 2.6–27.1). For motor development, inadequate calcium intake (aOR = 2.77; 95% CI: 1.23–6.22; p = 0.014) and non-exclusive breastfeeding (aOR = 2.32; 95% CI: 1.05–5.14; p = 0.037) were independently associated with suspected motor delay. Conclusion: Inadequate calcium intake was independently associated with both stunting and suspected motor delay among children aged 6–24 months in this rural setting. Antecedentes: El retraso en el crecimiento (stunting) sigue siendo un problema persistente de salud pública en Indonesia, particularmente en las zonas rurales. Objetivo: Examinar la asociación entre la ingesta de nutrientes y las prácticas de lactancia materna con el retraso en el crecimiento y el desarrollo motor en niños de 6 a 24 meses en zonas rurales de Indonesia. Métodos: Se realizó un estudio de casos y controles no apareado que incluyó 70 niños con retraso en el crecimiento y 70 sin retraso en el crecimiento. La ingesta de nutrientes se evaluó mediante un recordatorio dietético único de 24 horas y se comparó con las Ingestas Diarias Recomendadas específicas por edad. El retraso en el crecimiento se definió como una puntuación z de talla para la edad (HAZ) < −2 DE según los estándares de la OMS. El desarrollo motor se evaluó utilizando una herramienta de tamizaje estandarizada. Las asociaciones se analizaron mediante pruebas de chi-cuadrado y regresión logística multivariable. También se realizó un análisis de sensibilidad excluyendo a los lactantes con bajo peso al nacer. La significación estadística se estableció en p < 0,05. Resultados: En el análisis bivariado, la ingesta inadecuada de calcio mostró la asociación más fuerte con el retraso en el crecimiento (OR = 4,76; IC 95%: 2,33–9,72), seguida por la ingesta inadecuada de energía y proteínas. En el análisis multivariable, la ingesta inadecuada de calcio permaneció asociada de manera independiente con el retraso en el crecimiento (aOR = 12,01; IC 95%: 3,23–44,60; p < 0,001). El análisis de sensibilidad excluyendo a los lactantes con bajo peso al nacer atenuó la estimación, pero la asociación se mantuvo significativa (aOR = 8,4; IC 95%: 2,6–27,1). En cuanto al desarrollo motor, la ingesta inadecuada de calcio (aOR = 2,77; IC 95%: 1,23–6,22; p = 0,014) y la lactancia materna no exclusiva (aOR = 2,32; IC 95%: 1,05–5,14; p = 0,037) se asociaron de manera independiente con la sospecha de retraso motor. Conclusión: La ingesta inadecuada de calcio se asoció de manera independiente tanto con el retraso en el crecimiento como con la sospecha de retraso motor en niños de 6 a 24 meses en este entorno rural. Contexto: O atraso de crescimento continua a ser um problema persistente de saúde pública na Indonésia, particularmente nas zonas rurais. Objectivo: Examinar a associação entre a ingestão de nutrientes e as práticas de aleitamento materno com o atraso de crescimento e o desenvolvimento motor em crianças dos 6 aos 24 meses de idade na Indonésia rural. Métodos: Foi realizado um estudo caso-controlo não pareado, incluindo 70 crianças com e sem atraso de crescimento. A ingestão de nutrientes foi avaliada através de um único recordatório alimentar de 24 horas e comparada com as Ingestões Diárias Recomendadas específicas para a idade. O atraso de crescimento foi definido como um z-score de altura para idade (HAZ) < −2 DP, de acordo com os padrões da OMS. O desenvolvimento motor foi avaliado através de uma ferramenta de rastreio padronizada. As associações foram analisadas através de testes de qui-quadrado e regressão logística multivariável. Foi também realizada uma análise de sensibilidade excluindo os bebés com baixo peso ao nascer. A significância estatística foi definida como p < 0,05. Resultados: Na análise bivariada, a ingestão inadequada de cálcio apresentou a associação mais forte com o atraso no crescimento (OR = 4,76; IC 95%: 2,33–9,72), seguida pela ingestão inadequada de energia e proteína. Na análise multivariada, a ingestão inadequada de cálcio permaneceu associada de forma independente ao atraso do crescimento (OR ajustada = 12,01; IC 95%: 3,23–44,60; p < 0,001). A análise de sensibilidade, excluindo os lactentes com baixo peso à nascença, atenuou a estimativa, mas a associação manteve-se significativa (OR ajustada = 8,4; IC 95%: 2,6–27,1). Em relação ao desenvolvimento motor, a ingestão inadequada de cálcio (OR ajustada = 2,77; IC 95%: 1,23–6,22; p = 0,014) e o aleitamento materno não exclusivo (OR ajustada = 2,32; IC 95%: 1,05–5,14; p = 0,037) foram associados de forma independente à suspeita de atraso motor. Conclusão: A ingestão inadequada de cálcio foi associada de forma independente tanto ao atraso do crescimento como à suspeita de atraso motor em crianças dos 6 aos 24 meses de idade neste contexto rural.

Whether Ca and other micronutrients are equally distributed in an avian eggshell over its longitudinal section and what portion of these local resources are utilized by developing embryos are unanswered questions in avian reproductive physiology. Here, we measured the thickness and concentrations of Ca and 16 other chemical elements (Al, As, Cd, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Na, Ni, Pb, Se, and Sr) in 4 shell regions (sharp pole, equator, shoulder, blunt pole) of White Stork (Ciconia ciconia) eggs representing different stages of embryonic development, from unresorbed eggshells to almost fully resorbed ones (with near-to-hatch embryos). We found that unresorbed eggshells displayed several significant differences in the concentrations of 15 elements (Al, As, Ca, Cd, Co, Cr, Fe, K, Hg, Mg, Mn, Na, Ni, Se, and Sr) between various regions of the same shell. Only 2 metals (As and Ca) showed a cross-sectional decrease in concentrations from the sharp pole to the blunt one. In particular, we observed that unresorbed eggshells at the blunt pole were less calcified (with 2.4% less Ca) compared to the sharp pole. In contrast, the concentrations of 6 other metals (Co, Fe, Mg, Mn, Na, and Se) peaked in the relatively less calcified region of the blunt pole, where concentrations (such as Se) were up to 10 times as high as in other regions of unresorbed eggshells. Our findings highlight that eggshells over their longitudinal sections are not chemically homogeneous. Surprisingly, however, and contrary to our expectations, we found that unresorbed eggshells were thinner (2.1–5.9% less depending on the region) and at the same time more strongly calcified than resorbed eggshells. This suggests that some modification has occurred in the shell structure and raises the question of thin-shelled eggs in populations of wild birds.

Se incluyeron 501 pacientes, 420 mujeres (83,8%), con mediana de edad de 50 (18-60) años, mediana de PTH de: 42,3 (15,9-113,8) pg/ml, mediana de niveles de 25 hidroxivitamina D (25 (OH) D) de 24 (6,1-68) ng/ml, creatinina sérica de 0,76 (0,42-1,17) mg/dl. Los niveles de 25 (OH) D se distribuyeron así: ? 30 ng/ml: 24,9%, entre 20 y 29,9 ng/ml: 45,9%, entre 15 y 19,9 ng/ml: 17,9% y ? 15 ng/ml: 11,1%. Se encontró una relación inversa entre los valores de calcio y PTH, aunque la presencia de calcio sérico menor de 9 mg/dl fue del 23% en sujetos con 25 OH vit D menor de 15 ng/ml. El 52,2%, el 59,6% y el 63,2% de los pacientes con valores de 25 (OH) D de 15 a 19,9, de 20 a 30 y ?30 ng/ml, tuvieron PTH? 45 pg/ml. La probabilidad de tener un valor de PTH ? 45 pg/ml no tuvo diferencias estadísticamente significativas entre 20 y 30 ng/ml de 25 (OH) D. Los valores de 25 (OH) D ? 30 ng/ml tuvieron menor probabilidad de presentar PTH? 65 pg/ml, siendo del 14,3% con valores menores de 15 ng/ml vs 4,8% con valores ? 30 ng/ml. Aunque el 75% de la población evaluada tiene valores de 25 OH D menores de 30 ng/ml, la presencia de PTH mayor de 45 pg/ml ocurre en 40% de los sujetos entre 20 y 30 y cursan con calcio sérico menor de 9 mg/dl en 21%. Conclusión: Según el comportamiento del eje calcio-PTH- Vit D debe reconsiderarse el punto de corte de normalidad de la 25 OH D en 20 ng/ml para esta población entre 20 y 60 años sin otras comorbilidades. Abstract A total of 501 patients were included, 420 women (83.8%), median age 50 (18-60) years, median PTH: 42.3 (15.9-113.8) pg/ml, 25 hydroxy vitamin D (25 (OH) D: 24 (6.1-68) ng/ml, serum creatinine of 0.76 (0.42-1.17) mg/dl. Levels of 25 (OH) D were distributed as follows: ? 30 ng/ml: 24.9%, between 20 and 29.9 ng/ml: 45.9%, between 15 and 19.9 ng/ mL: 17.9% and ? 15 ng/ml: 11.1%. An inverse relationship was found between calcium and PTH values, although serum calcium below 9 mg/ dl was 23% in subjects with 25 oh vit D less than 15 ng/ml. The 52.2%, 59.6% and 63.2% of patients with 25 (OH) D with values between 15 to 19.9, 20 to 30 and ?30 ng/ml had PTH? 45 pg/ ml. The probability of having a PTH value ? 45 pg/ml had no statistically significant differences between 20 and 30 ng/ml of 25 (OH) D. The values of 25 (OH) D ? 30 ng/ml were less likely to present PTH?65 pg/ml, being 14.3% with values lower than 15 ng/ml vs 4.8% with values ? 30 ng/ml. Although 75% of the evaluated population has values of 25 oh D lower than 30 ng/ ml, the presence of PTH greater than 45 pg/ml occurs in 40% of the subjects between 20 and 30 and they present with serum calcium lower than 9 mg/dl in 21%. Conclusion: According to the behavior of the calcium-PTH- vit D axis, the normal cut-off point of 25 OH D of 20 ng/ml should be reconsidered for this population between 20 and 60 years without other comorbidities.

In this study, the catalytic activity of dolomite was evaluated for the transesterification of Colombian RBD palm oil with methanol, carried out in a batch reactor at 333,15K and 600rpm. The activated dolomites (calcined at 1073.15K for 2h) were characterized by scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), Hammett indicators method, and quantification of the surface area, average pore size and average pore volume BET. The influence of reaction variables such as catalyst amount (%wt /wt) and methanol / palm oil molar ratio (mole/mole) was investigated. Under the suitable reaction conditions, the amount of calcined dolomite equal to 4% (wt /wt) based on the weight of oil, the methanol-oil molar ratio equal to 9:1, and the reaction time = 1h, the methyl ester content of 82.67% of fatty acid methyl esters (FAME) can be achieved.

Introducción: la osteoporosis es el trastorno endocrino óseo más prevalente en adultos mayores y genera a nivel mundial una gran morbimortalidad. Las causas secundarias en hombres representan entre el 50?% y el 80?% de los casos. En el abordaje inicial es importante el estudio del metabolismo del calcio. Objetivo: presentar el caso de un paciente con osteoporosis secundaria y normocalcemia asociada a hipercalciuria significativa. Presentación del caso: presentamos un paciente masculino de 55 años, con antecedente de nefrolitiasis que consulta por dolor lumbar y en quien se hallan fracturas vertebrales por fragilidad a nivel torácico y lumbar. Se realiza diagnóstico de osteoporosis severa y la densitometría ósea sugiere causa secundaria, confirmando al final la presencia de mieloma múltiple. Discusión y conclusión: las fracturas por fragilidad siempre obligan a la búsqueda de osteoporosis. Cuando se presenta en un paciente masculino debe recordarse que en el 80?% de los casos se presenta una causa secundaria que obliga a la búsqueda de la enfermedad subyacente. La hipercalciuria es un trastorno que siempre debe ser adecuadamente caracterizado y los valores elevados extremos de velocidad de eritrosedimentación (VSG) tienen un significado patológico, especialmente en relación con enfermedades que generan una gran carga de inflamación.