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Scaffolds for the filling and regeneration of osteochondral defects are a current challenge in the biomaterials field, and solutions with greater functionality are still being sought. The novel approach of this work was to obtain scaffolds with biologically active additives possessing microstructural, permeability, and mechanical properties, mimicking the complexity of natural cartilage. Four types of scaffolds with a gelatin/alginate matrix modified with hydroxyapatite were obtained, and the relationship between the modifiers and substrate properties was evaluated. They differed in the type of second modifier used, which was hydrated MgCl2 in two proportions, ZnO, and nanohydroxyapatite. The samples were obtained by freeze-drying by using two-stage freezing. Based on microstructural observations combined with X-ray microanalysis, the microstructure of the samples and the elemental content were assessed. Permeability and mechanical tests were also performed. The scaffolds exhibited a network of interconnected pores and complex microarchitecture, with lower porosity at the surface (15 ± 7 to 29 ± 6%) and higher porosity at the center (67 ± 8 to 75 ± 8%). The additives had varying effects on the pore sizes and permeabilities of the samples. ZnO yielded the most permeable scaffolds (5.92 × 10-11 m2), whereas nanohydroxyapatite yielded the scaffold with the lowest permeability (1.18 × 10-11 m2), values within the range reported for trabecular bone. The magnesium content had no statistically significant effect on the permeability. The best mechanical parameters were obtained for ZnO samples and those containing hydrated MgCl2. The scaffold's properties meet the criteria for filling osteochondral defects. The developed scaffolds follow a biomimetic approach in terms of hierarchical microarchitecture and mechanical parameters as well as chemical composition. The obtained composite materials have the potential as biomimetic scaffolds for the regeneration of osteochondral defects.

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OBJECTIVE: Despite some knowledge gaps in scientific evidence, MgCl2 is largely used for pain relief in musculoskeletal diseases. Mg salts were shown to provide analgesia postoperatively in orthopedic surgery and low Mg levels were linked to arthritis development and severity. We determined the anti-inflammatory activity of MgCl2 in an acute arthritis model. METHODS: Mice received 0.1 mg/25µL Zymosan (Zy) or saline into the knees. Joint pain was evaluated using von Frey test; cell influx, and interleukin (IL)-1 level were assessed in joint lavage at 6 h. Synovia were excised for histopathology and analysis of immunoexpression of nuclear factor kappa B (NFκB) and tumor necrosis factor (TNF)-α. Groups (n = 6/group) received either 90 mg/kg MgCl2/100 µL or saline per os (systemic) or 500 µg/25 µL MgCl2 or saline intra-articularly (i.a.) 30 min prior to Zy. RESULTS: MgCl2 given either systemically or locally significantly reduced cell influx (p = 0.0012 and p = 0.0269, respectively), pain (p = 0.0005 and p = 0.0038, respectively), and intra-articular IL-1 level (p = 0.0391), as compared to saline. Systemic MgCl2 significantly decreased NFκB (p < 0.05) immmunoexpression, as compared to saline. CONCLUSION: MgCl2 given systemically or locally displayed anti-inflammatory activity in a severe acute arthritis model reducing cell influx, pain, and cytokine release. MgCl2 operates at least partially via inhibiting NFκB activation. This is the first in vivo demonstration that MgCl2 decreases cytokine release in arthritis, prompting reduction of inflammation and pain relief.

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Cells are dynamic systems with complex mechanical properties, regulated by the presence of different species of proteins capable to assemble (and disassemble) into filamentous forms as required by different cells functions. Giant unilamellar vesicles (GUVs) of DMPC (1,2-dimyristoyl-sn-glycero-3-phosphocholine) are systems frequently used as a simplified model of cells because they offer the possibility of assaying separately different stimuli, which is no possible in living cells. Here we present a study of the effect of acting protein on mechanical properties of GUVs, when the protein is inside the vesicles in either monomeric G-actin or filamentous F-actin. For this, rabbit skeletal muscle G-actin is introduced inside GUVs by the electroformation method. Protein polymerization inside the GUVs is promoted by adding to the solution MgCl2 and the ion carrier A23187 to allow the transport of Mg+2 ions into the GUVs. To determine how the presence of actin changes the mechanical properties of GUVs, the vesicles are deformed by the application of an AC electric field in both cases with G-actin and with polymerized F-actin. The changes in shape of the vesicles are characterized by optical microscopy and from them the bending stiffness of the membrane are determined. It is found that G-actin has no appreciable effect on the bending stiffness of DMPC GUVs, but the polymerized actin makes the vesicles more rigid and therefore more resistant to deformations. This result is supported by evidence that actin filaments tend to accumulate near the membrane.

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New perspectives arise in the therapeutic practice for cancer, with the objective to not only treat patients, but also improve their quality of life. Guarana, a plant from Brazilian Amazon presents a wide range of pharmacological actions. This study evaluated the effect of Guarana (Paullinia cupana) extract, pure and dry Guarana (PC-18) extract and magnesium chloride (MgCl2) in mice of the Balb/c strain inoculated with the Ehrlich tumor regarding gene expression of inflammatory markers transforming growth factor-ß1 and tumor necrosis factor alpha and oxidative stress (OS) and fatigue, superoxide dismutase, catalase, and glutathione peroxidase 4 and analyzed myelotoxicity and hepatotoxicity. After euthanasia, blood was collected to analyze the complete blood count and measured the levels of liver enzymes (alanine aminotransferase and aspartate aminotransferase). Hepatoprotective actions of the crude extract of P. cupana and PC-18 extract were noticed. The PC-18 and MgCl2 group showed the best result regarding animal welfare. There were no associations between compounds and gene expression regarding fatigue and OS. PC-18 reduced the tumor and may have an antitumor action. The crude extract of Guarana presented hepatoprotective action.

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Magnesium supplementation may be beneficial for cancer patients due to its action as a modulator of cell proliferation and metabolism and its anti-inflammatory effect. Tumor metabolism can influence the bioavailability and absorption of nutrients, leading to an increase in the individual's nutritional needs. In this work, the effects of supplementing different dosages of magnesium chloride in mice with solid Ehrlich's tumors were investigated by analyzing their hematological, inflammatory and anthropometric biomarkers. Three dosages of magnesium chloride (MgCl2) were administered for 28 consecutive days. Animal welfare was assessed according to the criteria stipulated by the National Center for the Replacement, Refinement, and Reduction of Animals in Research (NC3Rs). The inverted grid method was used to analyze muscle strength and fatigue. Difference in expression of the Tumor Necrosis Factor (TNF-α) and the Growth Transformation Factor (TGF-ß1) genes was determined by the 2-ΔCt method. The hematological evaluation consisted of the erythrogram, white blood cell and platelet counts were used for the hematological evaluation and treatment cytotoxicity. Difference in the expression of the TNF-α and TGF-ß genes showed that the group that received a high dose of magnesium had a decrease in TNF-α and RNL, an improvement in well-being with a tendency to increase muscle strength and less tumor progression according to the days of treatment. The group that received a low dosage of magnesium had a smaller tumor volume and a more controlled tumor growth according to the days. The group that received an intermediate dosage presented cytotoxicity.

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Evidence suggest that magnesium dietary supplementation has several health benefits including lowering blood pressure, reducing insulin resistance, and improving symptoms of depression, anxiety, and migraine. Here, we aimed to study the effect of chronic magnesium supplementation on anxiety-like behavior in rats by supplementing with magnesium their drinking water for 30 days. Anxiety-like behavior was induced by subcutaneous injection of veratrin 30 min before performing elevated plus maze and open field tests to measure anxiety levels and locomotion, respectively. We quantify the concentration of magnesium in plasma and cerebrospinal fluid. We used diazepam to compare the efficacy of magnesium supplementation as an anxiolytic agent. Our results show that rats supplemented with magnesium had a statistically significant decrease in anxiety levels with not effects on locomotion and a statistically significant increase in concentration of magnesium in plasma and cerebrospinal fluid. However, the anxiolytic effect of magnesium supplementation washes-out in 12 days. We discuss the advantages of using supplemental magnesium as anxiolytic.

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This study aimed to examine the efficacy of magnesium chloride therapy in sheep experimentally poisoned by Palicourea marcgravii and describe the clinical and laboratory findings that may aid in early ante mortem diagnosis of this poisoning. P. marcgravii is an important plant within a group of 22 species in Brazil that cause "sudden death." Its toxic component is sodium monofluoroacetate. It was observed that a time for evolution of poisoning was longer in our study compared to other studies that used the same dose of P. marcgravii in sheep. However, all animals that were poisoned and subsequently treated with magnesium chloride died. The sheep presented characteristic clinical signs before death in addition to other signs that have not been previously described for this type of poisoning, such as abdominal breathing, coughing, head pressing, and nystagmus. This is the first evaluation of hematological parameters of sheep poisoned by P. marcgravii. Leukocytosis with neutrophilia, hyperfibrinogenemia, and hyperglycemia, associated with hypophosphatemia and elevated levels of serum aspartato aminotransferase (AST), glutamate dehydrogenase (GLDH), urea, creatinine, creatine kinase (CK) and lactate dehydrogenase (LDH), were observed. Additionally, changes were noted in necropsy, such as engorged jugular, large vessel congestion, pulmonary edema. Histological examination revealed vacuolar hydropic degeneration in the distal twisted uriniferous tubules in the kidneys, similar to those reported in previous studies on P. marcgravii poisoning.(AU)

O presente estudo objetivou verificar a eficácia terapêutica do cloreto de magnésio em ovinos intoxicados experimentalmente por Palicourea marcgravii e descrever os achados clínicos e laboratoriais que possam auxiliar no diagnóstico precoce ante mortem dessa intoxicação. P. marcgravii é a principal planta dentro de um grupo de 22 espécies que causam "morte súbita" no Brasil e seu princípio tóxico é o monofluoracetato de sódio. Durante o procedimento, observou-se maior tempo de evolução em relação a outros trabalhos utilizando-se a mesma dose da P. marcgravii em ovinos, entretanto todos os animais intoxicados e posteriormente tratados com cloreto de magnésio vieram a óbito. Os ovinos apresentaram sinais clínicos característicos antes da morte, associados a sinais nunca antes descritos nesse tipo de intoxicação, como respiração abdominal, tosse, "head pressing" e nistagmo. Trata-se da primeira avaliação dos parâmetros hematológicos de ovinos intoxicados por P. marcgravi. Foi observado leucocitose com neutrofilia, hiperfibrinogemia e hiperglicemia, associado a elevação dos valores séricos de AST, GLDH, ureia, creatinina, CK, LDH e hipofosfatemia. À necropsia foram notadas alterações como jugular ingurgitada, congestão de grandes vasos, edema pulmonar. Histologicamente havia degeneração hidrópica vacuolar nos túbulos uriníferos contorcidos distais no rim, semelhantes às já relatadas em estudos anteriores, na intoxicação por P. marcgravii.(AU)

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This study aimed to examine the efficacy of magnesium chloride therapy in sheep experimentally poisoned by Palicourea marcgravii and describe the clinical and laboratory findings that may aid in early ante mortem diagnosis of this poisoning. P. marcgravii is an important plant within a group of 22 species in Brazil that cause "sudden death." Its toxic component is sodium monofluoroacetate. It was observed that a time for evolution of poisoning was longer in our study compared to other studies that used the same dose of P. marcgravii in sheep. However, all animals that were poisoned and subsequently treated with magnesium chloride died. The sheep presented characteristic clinical signs before death in addition to other signs that have not been previously described for this type of poisoning, such as abdominal breathing, coughing, head pressing, and nystagmus. This is the first evaluation of hematological parameters of sheep poisoned by P. marcgravii. Leukocytosis with neutrophilia, hyperfibrinogenemia, and hyperglycemia, associated with hypophosphatemia and elevated levels of serum aspartato aminotransferase (AST), glutamate dehydrogenase (GLDH), urea, creatinine, creatine kinase (CK) and lactate dehydrogenase (LDH), were observed. Additionally, changes were noted in necropsy, such as engorged jugular, large vessel congestion, pulmonary edema. Histological examination revealed vacuolar hydropic degeneration in the distal twisted uriniferous tubules in the kidneys, similar to those reported in previous studies on P. marcgravii poisoning.(AU)

O presente estudo objetivou verificar a eficácia terapêutica do cloreto de magnésio em ovinos intoxicados experimentalmente por Palicourea marcgravii e descrever os achados clínicos e laboratoriais que possam auxiliar no diagnóstico precoce ante mortem dessa intoxicação. P. marcgravii é a principal planta dentro de um grupo de 22 espécies que causam "morte súbita" no Brasil e seu princípio tóxico é o monofluoracetato de sódio. Durante o procedimento, observou-se maior tempo de evolução em relação a outros trabalhos utilizando-se a mesma dose da P. marcgravii em ovinos, entretanto todos os animais intoxicados e posteriormente tratados com cloreto de magnésio vieram a óbito. Os ovinos apresentaram sinais clínicos característicos antes da morte, associados a sinais nunca antes descritos nesse tipo de intoxicação, como respiração abdominal, tosse, "head pressing" e nistagmo. Trata-se da primeira avaliação dos parâmetros hematológicos de ovinos intoxicados por P. marcgravi. Foi observado leucocitose com neutrofilia, hiperfibrinogemia e hiperglicemia, associado a elevação dos valores séricos de AST, GLDH, ureia, creatinina, CK, LDH e hipofosfatemia. À necropsia foram notadas alterações como jugular ingurgitada, congestão de grandes vasos, edema pulmonar. Histologicamente havia degeneração hidrópica vacuolar nos túbulos uriníferos contorcidos distais no rim, semelhantes às já relatadas em estudos anteriores, na intoxicação por P. marcgravii.(AU)

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The development of non-enzymatic browning in the presence of MgCl2 was evaluated in liquid and dehydrated sucrose-glycine model systems, in relation to interactions of the salt with water and/or with sucrose. In both systems, browning was accelerated by the presence of MgCl2 because of the increased sugar hydrolysis (ten times faster) and the reduction of water mobility (1H NMR T2 relaxation times) caused by this salt (between 6 and 14% lower), counteracting the inhibitory effect of water on the Maillard reaction. MgCl2 also provoked a 40% reduction on the fluorophores quantum yield, responsible also of the fluctuations observed in the fluorescence development as a function of time after 50 h at 70 °C. Molecular and supramolecular effects of the presence of MgCl2 have been observed on the Maillard reaction kinetics. These results are of high technological interest when strategies to control the Maillard reaction rate are required for a particular application.

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The present study evaluated the effect of three anesthetics at three concentrations, menthol (C10H20O) (1%, 1.5%, 2%), eugenol (C10H12O2) (0.5%, 1%, 1.5%) and magnesium chloride (MgCl2) (4%, 7%, 10%) diluted in distilled water, on the gastropod Littoraria angulifera. Twenty females were tested for each concentration with shell height varying between 18.3 and 26.1 mm (n = 180), all collected from the same site in the estuary of Barra do Sargi-Uruçuca, Bahia (Brazil). The time of induction and recovery of the sedative effect, as well as the survival rate, were assessed. The animals were kept at a temperature of 25 ± 1 °C and observations were made every 30 minutes since the beginning of the anesthesia for up to 2 hours. After this period, the animals were observed during the following 15 days for survival evaluation. Only MgCl2 caused a sedative effect on L. angulifera. At 4% and 7% MgCl2 solutions, 20% and 95% of animals were anesthetized after 2 hours, respectively, and at 10% all animals were anesthetized after 1 hour. In conclusion, L. angulifera can be efficiently anesthetized in a 10% MgCl2 solution for 1 h and the recovery occurs after 1 h with no apparent side effects on behavior and survival.

O presente estudo avaliou o efeito de três anestésicos em três concentrações, o mentol (C10H20O) (1%; 1,5%; 2%), o eugenol (C10H12O2) (0,5%; 1%; 1,5%) e o cloreto de magnésio (MgCl2) (4%; 7%; 10%), diluídos em água destilada, sobre fêmeas do gastrópode Littoraria angulifera. Para cada concentração foram utilizadas 20 fêmeas (total = 180), com altura da concha entre 18,3 e 26,1 mm, coletadas no mesmo local, no estuário da Barra do Sargi-Uruçuca, Bahia. Foram observados os tempos de indução e de recuperação do efeito sedativo, assim como a sobrevivência. Os animais foram mantidos a uma temperatura laboratorial de 25 ± 1 °C e as observações foram feitas a cada 30 minutos após a anestesia, durante 2 horas. Após o término do experimento, os animais foram observados por 15 dias quanto à sobrevivência. Apenas o MgCl2 causou efeito sedativo sobre L. angulifera, sendo que a 4% e a 7% observou-se sedação de 20% e de 95% dos animais, respectivamente, após 2 horas de anestesia, enquanto que a 10%, todos os animais foram anestesiados em 1 hora. Em conclusão, L. angulifera pode ser anestesiada de forma eficiente em uma solução de 10% de MgCl2 durante 1 h e a sua recuperação ocorre ao fim de 1 h sem nenhum efeito colateral evidente no comportamento e na sobrevivência.

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O magnésio é um íon mineral essencial para o organismo humano atuando como cofator de enzimas em mais de 300 reações metabólicas, além de correlacionar-se com o cálcio de maneira sinérgica e antagônica. A hipomagnesemia no organismo está associada a cãibras musculares, hipertensão e vaso espasmos coronarianos e cerebrais, além de induzir o estresse oxidativo e aumentar a produção de radicais livres. É recomendada ingestão de 10 a 20% a mais deste elemento na dieta de atletas, pois a perda deste íon é elevada na urina e no suor. O excesso do mineral desencadeia hipermagnesemia, sobrecarrega funções renais e é imprescindível que a homeostase seja sempre mantida no organismo humano. O presente trabalho objetivou avaliar a condição basal de micronutrientes em um grupo de vinte pessoas com idade entre 45 e 80 anos praticantes regulares de exercícios físicos no CEFER da USP no campus de Ribeirão Preto-SP, que se dispuseram a fazer uma suplementação deste íon, iniciando com dose de 1g diário e treinamento funcional de atividades físicas...

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The present study evaluated the effect of three anesthetics at three concentrations, menthol (C10H20O) (1%, 1.5%, 2%), eugenol (C10H12O2) (0.5%, 1%, 1.5%) and magnesium chloride (MgCl2) (4%, 7%, 10%) diluted in distilled water, on the gastropod Littoraria angulifera. Twenty females were tested for each concentration with shell height varying between 18.3 and 26.1 mm (n = 180), all collected from the same site in the estuary of Barra do Sargi-Uruçuca, Bahia (Brazil). The time of induction and recovery of the sedative effect, as well as the survival rate, were assessed. The animals were kept at a temperature of 25 ± 1 °C and observations were made every 30 minutes since the beginning of the anesthesia for up to 2 hours. After this period, the animals were observed during the following 15 days for survival evaluation. Only MgCl2 caused a sedative effect on L. angulifera. At 4% and 7% MgCl2 solutions, 20% and 95% of animals were anesthetized after 2 hours, respectively, and at 10% all animals were anesthetized after 1 hour. In conclusion, L. angulifera can be efficiently anesthetized in a 10% MgCl2 solution for 1 h and the recovery occurs after 1 h with no apparent side effects on behavior and survival.(AU)

O presente estudo avaliou o efeito de três anestésicos em três concentrações, o mentol (C10H20O) (1%; 1,5%; 2%), o eugenol (C10H12O2) (0,5%; 1%; 1,5%) e o cloreto de magnésio (MgCl2) (4%; 7%; 10%), diluídos em água destilada, sobre fêmeas do gastrópode Littoraria angulifera. Para cada concentração foram utilizadas 20 fêmeas (total = 180), com altura da concha entre 18,3 e 26,1 mm, coletadas no mesmo local, no estuário da Barra do Sargi-Uruçuca, Bahia. Foram observados os tempos de indução e de recuperação do efeito sedativo, assim como a sobrevivência. Os animais foram mantidos a uma temperatura laboratorial de 25 ± 1 °C e as observações foram feitas a cada 30 minutos após a anestesia, durante 2 horas. Após o término do experimento, os animais foram observados por 15 dias quanto à sobrevivência. Apenas o MgCl2 causou efeito sedativo sobre L. angulifera, sendo que a 4% e a 7% observou-se sedação de 20% e de 95% dos animais, respectivamente, após 2 horas de anestesia, enquanto que a 10%, todos os animais foram anestesiados em 1 hora. Em conclusão, L. angulifera pode ser anestesiada de forma eficiente em uma solução de 10% de MgCl2 durante 1 h e a sua recuperação ocorre ao fim de 1 h sem nenhum efeito colateral evidente no comportamento e na sobrevivência.(AU)

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Salar de Uyuni (SdU), with a geological history that reflects 50 000 years of climate change, is the largest hypersaline salt flat on Earth and is estimated to be the biggest lithium reservoir in the world. Its salinity reaches saturation levels for NaCl, a kosmotropic salt, and high concentrations of MgCL2 and LiCl, both salts considered important chaotrophic stressors. In addition, extreme temperatures, anoxic conditions, high UV irradiance, high albedo and extremely low concentrations of phosphorous, make SdU a unique natural extreme environment in which to contrast hypotheses about limiting factors of life diversification. Geophysical studies of brines from different sampling stations show that water activity is rather constant along SdU. Geochemical measurements show significant differences in magnesium concentration, ranging from 0.2 to 2M. This work analyses the prokaryotic diversity and community structure at four SdU sampling stations, selected according to their location and ionic composition. Prokaryotic communities were composed of both Archaea (with members of the classes Halobacteria, Thermoplasmata and Nanohaloarchaea, from the Euryarchaeota and Nanohaloarcheota phyla respectively) and Bacteria (mainly belonging to Bacteroidetes and Proteobacteria phyla). The important differences in composition of microbial communities inversely correlate with Mg2+ concentration, suggesting that prokaryotic diversity at SdU is chaotropic dependent.

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BACKGROUND: The effectiveness and safety of balanced crystalloid fluids compared with saline (0.9% sodium chloride) as a fluid of choice in critically ill patients remain unclear. The effects of different fluid infusion rates on outcomes are also unknown. OBJECTIVES: To test the hypothesis that a balanced crystalloid solution, compared with saline, decreases 90-day all-cause mortality among critically ill patients; and to test the hypothesis that slow, compared with rapid, infusion rate decreases 90-day mortality in this population of patients. METHODS: The Balanced Solution versus Saline in Intensive Care Study (BaSICS) is a pragmatic, 2 ??2 factorial, randomised controlled trial. A total of 11 000 patients will be recruited from at least 100 Brazilian intensive care units. Patients will be randomised to receive Plasma-Lyte 148 or saline, and to rapid infusion (999 mL/h) or slow infusion (333 mL/h). Study fluids will be used for resuscitation episodes (at rapid or slow infusion rates), dilution of compatible medications and maintenance solutions. Patients, health care providers and investigators will be blinded to the solutions being tested. The rate of bolus infusion will not be blinded. OUTCOMES: The primary outcome is 90-day all-cause mortality. Secondary outcomes are: incidence of renal failure requiring renal replacement therapy within 90 days, incidence of acute kidney injury (Kidney Disease: Improving Global Outcomes stages 2 and 3), incidence of non-renal organ dysfunction assessed by Sepsis-related Organ Failure Assessment score at Days 3 and 7, and number of mechanical ventilationfree days within the first 28 days after randomisation. RESULTS AND CONCLUSIONS: The BaSICS trial will provide robust evidence on whether a balanced crystalloid, compared with saline, improves important patient outcomes in critically ill patients. BaSICS will also provide relevant information on whether bolus infusion rate affects outcomes in this population. TRIAL REGISTRATION: ClinicalTrials.gov NCT02875873.

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This study evaluated: 1) the time required for anaesthesia induction and recovery of oysters Crassostrea rhizophorae, Crassostrea gasar and Crassostrea gigas using magnesium chloride (MgCl2); 2) the survival after anaesthesia and gonad sampling; and 3) the D-larvae generation after anaesthesia. For each species, three groups of 10 animals were kept in 50 g L-1 MgCl2, salinity of 36 and temperature of 22 ºC. One control group was kept in solution without MgCl2. Every 1 h anaesthetised oysters were recorded, sampled to determine sex and placed in clean seawater to assess recovering every 30 min. Gonad samplings were made beside the posterior adductor muscle, using 1 mL syringes and needles (0.60 x 25 mm). Factorial crosses were generated within and between anaesthetised and non-anaesthetised oyster groups to produce D-larvae in C. gigas. The survival after 10 days of anaesthesia was 100% for the three studied species. For C. rhizophorae and C. gigas, 100% of the animals were anaesthetised after 360 min and were recovered after 240 and 150 min, respectively. For C. gasar, 87% were anesthetised after 720 min and recovered after >240 min. There were no significant differences in D-larvae numbers between factorial crosses. The salt MgCl2 served as an efficient relaxant and caused no deleterious effect on the survival of the three studied species, or on the D-larvae generation in C. gigas.

Este estudo avaliou: 1) o tempo necessário para indução à anestesia e recuperação das ostras Crassostrea rhizophorae, Crassostrea gasar e Crassostrea gigas utilizando cloreto de magnésio (MgCl2); 2) a sobrevivência após anestesia e amostragem gonadal; e 3) a geração de larvas-D após anestesia. Para cada espécie, três grupos de 10 animais foram mantidos em 50 g L-1 de MgCl2, salinidade de 36 e temperatura de 22 ºC. Um grupo controle foi mantido em solução sem MgCl2. A cada 1 h, ostras anestesiadas foram registradas, amostradas para determinar sexo e colocadas em água do mar limpa para avaliar a recuperação a cada 30 min. Amostragens das gônadas foram feitas ao lado do músculo adutor posterior, usando seringas de 1 mL e agulha de 0,60 x 25 mm. Cruzamentos fatoriais foram gerados dentro e entre grupos de ostras anestesiadas e não anestesiadas para produzir larvas-D em C. gigas. A sobrevivência após 10 dias de anestesia foi de 100% para as três espécies. Para C. rhizophorae e C. gigas, 100% dos animais foram anestesiados após 360 min e recuperados após 240 e 150 min, respectivamente. Para C. gasar, 87% foram anestesiados após 720 min e recuperados após >240 min. Não houve diferença significativa no número de larvas-D entre os cruzamentos. O sal MgCl2 serviu como relaxante eficiente e não causou efeitos deletérios sobre a sobrevivência das três espécies estudadas ou na geração de larvas-D de C. gigas.

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This study evaluated: 1) the time required for anaesthesia induction and recovery of oysters Crassostrea rhizophorae, Crassostrea gasar and Crassostrea gigas using magnesium chloride (MgCl2); 2) the survival after anaesthesia and gonad sampling; and 3) the D-larvae generation after anaesthesia. For each species, three groups of 10 animals were kept in 50 g L-1 MgCl2, salinity of 36 and temperature of 22 ºC. One control group was kept in solution without MgCl2. Every 1 h anaesthetised oysters were recorded, sampled to determine sex and placed in clean seawater to assess recovering every 30 min. Gonad samplings were made beside the posterior adductor muscle, using 1 mL syringes and needles (0.60 x 25 mm). Factorial crosses were generated within and between anaesthetised and non-anaesthetised oyster groups to produce D-larvae in C. gigas. The survival after 10 days of anaesthesia was 100% for the three studied species. For C. rhizophorae and C. gigas, 100% of the animals were anaesthetised after 360 min and were recovered after 240 and 150 min, respectively. For C. gasar, 87% were anesthetised after 720 min and recovered after >240 min. There were no significant differences in D-larvae numbers between factorial crosses. The salt MgCl2 served as an efficient relaxant and caused no deleterious effect on the survival of the three studied species, or on the D-larvae generation in C. gigas.(AU)

Este estudo avaliou: 1) o tempo necessário para indução à anestesia e recuperação das ostras Crassostrea rhizophorae, Crassostrea gasar e Crassostrea gigas utilizando cloreto de magnésio (MgCl2); 2) a sobrevivência após anestesia e amostragem gonadal; e 3) a geração de larvas-D após anestesia. Para cada espécie, três grupos de 10 animais foram mantidos em 50 g L-1 de MgCl2, salinidade de 36 e temperatura de 22 ºC. Um grupo controle foi mantido em solução sem MgCl2. A cada 1 h, ostras anestesiadas foram registradas, amostradas para determinar sexo e colocadas em água do mar limpa para avaliar a recuperação a cada 30 min. Amostragens das gônadas foram feitas ao lado do músculo adutor posterior, usando seringas de 1 mL e agulha de 0,60 x 25 mm. Cruzamentos fatoriais foram gerados dentro e entre grupos de ostras anestesiadas e não anestesiadas para produzir larvas-D em C. gigas. A sobrevivência após 10 dias de anestesia foi de 100% para as três espécies. Para C. rhizophorae e C. gigas, 100% dos animais foram anestesiados após 360 min e recuperados após 240 e 150 min, respectivamente. Para C. gasar, 87% foram anestesiados após 720 min e recuperados após >240 min. Não houve diferença significativa no número de larvas-D entre os cruzamentos. O sal MgCl2 serviu como relaxante eficiente e não causou efeitos deletérios sobre a sobrevivência das três espécies estudadas ou na geração de larvas-D de C. gigas.(AU)

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The ion distribution around hydroxylated silica nanoparticles (NP-H) dispersed in brine was investigated by fully atomistic molecular dynamics. The NP-H dispersions in aqueous electrolyte media are simulated in solutions of varying salinity (NaCl, CaCl2, and MgCl2), salt concentration (0.06 × 10(-3) to 3.00 × 10(-3) mole fraction [Formula: see text]), and temperature (300 and 350 K) at 1 atm. The NP-H models reproduce the observed experimental concentration of silanol and geminal surface sites, which are responsible for local charge variations on the nanoparticles' surface. Interestingly, under certain salt concentration conditions, the formation of an electrical double layer (DL) around the overall neutral NP-H occurs. The resulting DLs are attenuated with increasing temperature for all evaluated salts. With increasing salt concentration, a sign inversion of the effective charge at the first ion layer is observed, which modifies the electrostatic environment around the nanoparticle. The minimum salt concentration that leads to a DL formation at 300 K is 1.05 × 10(-3), 0.37 × 10(-3), and 0.06 × 10(-3) χs for NaCl, CaCl2, and MgCl2, respectively. The width of the DL decreases sequentially in ionic strength from NaCl to CaCl2 to MgCl2, which is similar to that found for highly charged surfaces. These results are in line with our previous experimental data for negative charged NP-H. All together, these observations suggest an interplay mechanism between the formation and narrowing of electric double layers on the stability of NP dispersions in both neutral and negatively charged NP-H.

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AIM: This study evaluated the efficacy of oral magnesium supplementation in the reduction of plasma glucose levels in adults with prediabetes and hypomagnesaemia. METHODS: A total of 116 men and non-pregnant women, aged 30 to 65 years with hypomagnesaemia and newly diagnosed with prediabetes, were enrolled into a randomized double-blind placebo-controlled trial to receive either 30 mL of MgCl2 5% solution (equivalent to 382 mg of magnesium) or an inert placebo solution once daily for four months. The primary trial endpoint was the efficacy of magnesium supplementation in reducing plasma glucose levels. RESULTS: At baseline, there were no significant statistical differences in terms of anthropometric and biochemical variables between individuals in the supplement and placebo groups. At the end of follow-up, fasting (86.9 ± 7.9 and 98.3 ± 4.6 mg/dL, respectively; P = 0.004) and post-load glucose (124.7 ± 33.4 and 136.7 ± 23.9 mg/dL, respectively; P = 0.03) levels, HOMA-IR indices (2.85 ± 1.0 and 4.1 ± 2.7, respectively; P = 0.04) and triglycerides (166.4 ± 90.6 and 227.0 ± 89.7, respectively; P = 0.009) were significantly decreased, whereas HDL cholesterol (45.6 ± 10.9 and 46.8 ± 9.2 mg/dL, respectively; P = 0.04) and serum magnesium (1.96 ± 0.27 and 1.60 ± 0.26 mg/dL, respectively; P = 0.005) levels were significantly increased in those taking MgCl2 compared with the controls. A total of 34 (29.4%) people improved their glucose status (50.8% and 7.0% in the magnesium and placebo groups, respectively; P < 0.0005). CONCLUSION: Our results show that magnesium supplementation reduces plasma glucose levels, and improves the glycaemic status of adults with prediabetes and hypomagnesaemia.

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