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1.
Nat Commun ; 11(1): 4955, 2020 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-33009385

RESUMO

The light-harvesting-reaction center complex (LH1-RC) from the purple phototrophic bacterium Thiorhodovibrio strain 970 exhibits an LH1 absorption maximum at 960 nm, the most red-shifted absorption for any bacteriochlorophyll (BChl) a-containing species. Here we present a cryo-EM structure of the strain 970 LH1-RC complex at 2.82 Å resolution. The LH1 forms a closed ring structure composed of sixteen pairs of the αß-polypeptides. Sixteen Ca ions are present in the LH1 C-terminal domain and are coordinated by residues from the αß-polypeptides that are hydrogen-bonded to BChl a. The Ca2+-facilitated hydrogen-bonding network forms the structural basis of the unusual LH1 redshift. The structure also revealed the arrangement of multiple forms of α- and ß-polypeptides in an individual LH1 ring. Such organization indicates a mechanism of interplay between the expression and assembly of the LH1 complex that is regulated through interactions with the RC subunits inside.


Assuntos
Cálcio/metabolismo , Microscopia Crioeletrônica , Complexos de Proteínas Captadores de Luz/ultraestrutura , Peptídeos/metabolismo , Fotossíntese , Sequência de Aminoácidos , Bacterioclorofila A/metabolismo , Sítios de Ligação , Chromatiaceae/metabolismo , Detergentes/química , Dimerização , Complexos de Proteínas Captadores de Luz/química , Complexos de Proteínas Captadores de Luz/metabolismo , Lipídeos/química , Peptídeos/química , Quinonas/química
2.
Braz Dent J ; 31(4): 385-391, 2020 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-32901714

RESUMO

The present study evaluated the odontogenic potential of human dental pulp cells (HDPCs) exposed to chitosan scaffolds containing calcium aluminate (CHAlCa) associated or not with low doses of simvastatin (SV). Chitosan scaffolds received a suspension of calcium aluminate (AlCa) and were then immersed into solutions containing SV. The following groups were established: chitosan-calcium-aluminate scaffolds (CHAlCa - Control), chitosan calcium-aluminate with 0.5 µM SV (CHAlCa-SV0.5), and chitosan calcium-aluminate with 1.0 µM SV (CHAlCa-SV1.0). The morphology and composition of the scaffolds were evaluated by SEM and EDS, respectively. After 14 days of HDPCs culture on scaffolds, cell viability, adhesion and spread, mineralized matrix deposition as well as gene expression of odontogenic markers were assessed. Calcium aluminate particles were incorporated into the chitosan matrix, which exhibited regular pores homogeneously distributed throughout its structure. The selected SV dosages were biocompatible with HDPCs. Chitosan-calcium-aluminate scaffolds with 1 µM SV induced the odontoblastic phenotype in the HDPCs, which showed enhanced mineralized matrix deposition and up-regulated ALP, Col1A1, and DMP-1 expression. Therefore, one can conclude that the incorporation of calcium aluminate and simvastatin in chitosan scaffolds had a synergistic effect on HDPCs, favoring odontogenic cell differentiation and mineralized matrix deposition.


Assuntos
Quitosana , Compostos de Alumínio , Cálcio , Compostos de Cálcio , Humanos , Porosidade , Sinvastatina
3.
Acta Odontol Latinoam ; 33(2): 82-89, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32920609

RESUMO

The aim of this study was to evaluate the degree of conversion, cytotoxicity, solubility and pH of photopolymerizable calciumbased cements submitted to preheating. The degree of conversion was analyzed by Fourier transform infrared, cytotoxicity by the MTT test and solubility through loss of mass. The data were subjected to statistical tests (ANOVA / Tukey's, p<0.05). The photopolymerizable materials showed a low degree of conversion, regardless of preheating. All materials caused a reduction in cell viability at 24 hours and 7 days, with the Dycal (control) being more cytotoxic. Heat had a positive effect on Biocal at 7 days. Dycal is the most soluble material. Heat had no effect on the solubility or pH of the polymerizable materials. It is concluded that photopolymerizable calcium-based cements have a low degree of conversion and are soluble, which results in mild to moderate cytotoxicity.


Assuntos
Hidróxido de Cálcio/toxicidade , Sobrevivência Celular/efeitos dos fármacos , Cimentos Dentários/química , Agentes de Capeamento da Polpa Dentária e Pulpectomia/toxicidade , Cálcio , Hidróxido de Cálcio/química , Cimentos Dentários/toxicidade , Capeamento da Polpa Dentária , Humanos , Concentração de Íons de Hidrogênio , Cura Luminosa de Adesivos Dentários , Processos Fotoquímicos , Polimerização , Agentes de Capeamento da Polpa Dentária e Pulpectomia/química
4.
Chemosphere ; 254: 126905, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32957298

RESUMO

With the development of modern technologies, the exploitation and application of rare earth metals (REMs) have increased parallelly. Consequently, more REMs are entering into the environment and therefore there is a pressing need to assess their potential environmental hazards. Here, a standard toxicity test with wheat (Triticum aestivum) was conducted to investigate the single and mixture toxicity of La and Ce in solutions with different levels of calcium and nitrilotriacetic acid (NTA) and results were deciphered by different modeling approaches. Both La and Ce caused adverse effect to wheat, but the presence of Ca and NTA alleviated their toxicity. The obtained EC50 for [La] or [Ce] changed by more than 28-fold and by 4-fold, respectively, with the increase of Ca or NTA. The biotic ligand model (BLM) explained approximately 93% variation of single La or Ce toxicity. The binding constants obtained were 4.14, 6.67, and 6.59 for logKCaBL, logKLaBL, and logKCeBL respectively. The electrostatic toxicity model (ETM) was proved as effective as the BLM, with R2 = 0.93 for La and R2 = 0.92 for Ce. For La-Ce mixtures, parameters from single toxicity approaches were applied successfully to predict the mixture toxicity with concentration addition (CA) model based on the BLM or ETM theory (R2 = 0.92 and RMSE = 8.56; R2 = 0.90 and RMSE = 9.6, respectively). Thus, the results obtained in this study prove that both ETM and BLM theories are appropriate to predict single and mixture REMs toxicity, providing coherent and promising tools for the risk assessment of REM pollution.


Assuntos
Cálcio/química , Cério/toxicidade , Lantânio/toxicidade , Ácido Nitrilotriacético/química , Testes de Toxicidade/métodos , Triticum/efeitos dos fármacos , Ligantes , Modelos Teóricos , Soluções , Eletricidade Estática , Triticum/crescimento & desenvolvimento
5.
Nat Commun ; 11(1): 4614, 2020 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-32929069

RESUMO

The suprachiasmatic nucleus (SCN) is a complex structure dependent upon multiple mechanisms to ensure rhythmic electrical activity that varies between day and night, to determine circadian adaptation and behaviours. SCN neurons are exposed to glutamate from multiple sources including from the retino-hypothalamic tract and from astrocytes. However, the mechanism preventing inappropriate post-synaptic glutamatergic effects is unexplored and unknown. Unexpectedly we discovered that TRESK, a calcium regulated two-pore potassium channel, plays a crucial role in this system. We propose that glutamate activates TRESK through NMDA and AMPA mediated calcium influx and calcineurin activation to then oppose further membrane depolarisation and rising intracellular calcium. Hence, in the absence of TRESK, glutamatergic activity is unregulated leading to membrane depolarisation, increased nocturnal SCN firing, inverted basal calcium levels and impaired sensitivity in light induced phase delays. Our data reveals TRESK plays an essential part in SCN regulatory mechanisms and light induced adaptive behaviours.


Assuntos
Adaptação Ocular , Escuridão , Canais de Potássio/metabolismo , Núcleo Supraquiasmático/fisiologia , Animais , Comportamento Animal , Cálcio/metabolismo , Ácido Glutâmico/metabolismo , Luz , Potenciais da Membrana/efeitos da radiação , Camundongos Endogâmicos C57BL , Canais de Potássio/deficiência , Transdução de Sinais/efeitos da radiação , Núcleo Supraquiasmático/efeitos da radiação
7.
Nature ; 585(7826): 507-508, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32895562
10.
Braz Oral Res ; 34: e115, 2020 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-32901730

RESUMO

The aim of the present transversal study was to evaluate the clinical and biochemical salivary parameters of children with and without erosive tooth wear (ETW). The study population was children aged 4 to 9 years. A trained and calibrated examiner (kappa value for intraexaminer reliability = 0.89) classified the children into ETW (n = 24) and control groups (n = 24), and applied the O'Brien index. The salivary flow rate was initially evaluated by stimulated sialometry (paraffin chewing). Afterwards, the collected saliva was submitted to biochemical analyses of pH, uric acid, total buffering capacity, ferric-reducing antioxidant power, reduced glutathione, calcium, and phosphorus. Among the ETW children, 20 (83%) had dental lesions restricted to enamel, and 4 (17%) presented lesions affecting both enamel and dentin. A statistically significant difference between the groups was obtained only for the pH values (t-test; p = 0.004), with averages of 7.31 and 7.56 for the control and the ETW groups, respectively. Considering the parameters evaluated in general, it is suggested that the salivary profile of children with ETW does not differ considerably from that of children without ETW. However, the pH mean value seems to be slightly higher in ETW children, but is still within the normal physiological range.


Assuntos
Desgaste dos Dentes , Cálcio , Criança , Pré-Escolar , Esmalte Dentário , Humanos , Saliva , Erosão Dentária
11.
Crit Care Resusc ; 22(3): 275-280, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32900336

RESUMO

OBJECTIVE: To help shape the design of a future double blind placebo-controlled randomised clinical trial of bicarbonate therapy for metabolic acidosis, based on opinions of intensive care clinicians in Australia and New Zealand. DESIGN: An online survey was designed, piloted and distributed electronically to members of the Australian and New Zealand Intensive Care Society Clinical Trials Group (ANZICS CTG) mailing list. The survey sought to collect information about choice of placebo, method of bicarbonate administration, and acid-base monitoring. MAIN OUTCOME MEASURES: Responses to six questions in the following domains were sought: 1) solution to be used as placebo; 2) method of administration; 3) target of the intervention; 4) timing of arterial blood gases to monitor the intervention; 5) duration of therapy; and 6) rate of bolus therapy (if selected as the best option). RESULTS: One in every eight ANZICS CTG members completed the survey (118/880, 13.4%). Compound sodium lactate was the preferred solution for placebo (54/118, 45.8%), and continuous infusion of bicarbonate (80/118, 67.8%) was the most frequently selected method of administration. A pH > 7.30 was the preferred target (50/118, 42.4%), while monitoring with arterial blood gas analysis every 2 hours until the target is reached and then every 4 hours was the most favoured option (40/118, 33.9%). The preferred duration of therapy was until the target is achieved (53/118, 44.9%). CONCLUSIONS: This survey offers important insights into the preferences of Australian and New Zealand clinicians in regards to any future randomised controlled trial of bicarbonate therapy for metabolic acidosis in the critically ill.


Assuntos
Acidose/tratamento farmacológico , Bicarbonato de Sódio/uso terapêutico , Acidose/sangue , Austrália , Cálcio/sangue , Cuidados Críticos , Estado Terminal , Método Duplo-Cego , Humanos , Nova Zelândia , Bicarbonato de Sódio/efeitos adversos , Inquéritos e Questionários , Resultado do Tratamento
12.
Nat Commun ; 11(1): 4581, 2020 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-32917893

RESUMO

Yes-associated protein 1 (YAP) is a transcriptional regulator with critical roles in mechanotransduction, organ size control, and regeneration. Here, using advanced tools for real-time visualization of native YAP and target gene transcription dynamics, we show that a cycle of fast exodus of nuclear YAP to the cytoplasm followed by fast reentry to the nucleus ("localization-resets") activates YAP target genes. These "resets" are induced by calcium signaling, modulation of actomyosin contractility, or mitosis. Using nascent-transcription reporter knock-ins of YAP target genes, we show a strict association between these resets and downstream transcription. Oncogenically-transformed cell lines lack localization-resets and instead show dramatically elevated rates of nucleocytoplasmic shuttling of YAP, suggesting an escape from compartmentalization-based control. The single-cell localization and transcription traces suggest that YAP activity is not a simple linear function of nuclear enrichment and point to a model of transcriptional activation based on nucleocytoplasmic exchange properties of YAP.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Fatores de Transcrição/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Sistemas CRISPR-Cas , Cálcio/metabolismo , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Citoplasma/metabolismo , Regulação da Expressão Gênica , Técnicas de Introdução de Genes , Células HEK293 , Humanos , Mecanotransdução Celular/fisiologia , Oncogenes/genética , Fatores de Transcrição/genética
13.
Nat Commun ; 11(1): 4416, 2020 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-32887881

RESUMO

Despite the clear association between myocardial injury, heart failure and depressed myocardial energetics, little is known about upstream signals responsible for remodeling myocardial metabolism after pathological stress. Here, we report increased mitochondrial calmodulin kinase II (CaMKII) activation and left ventricular dilation in mice one week after myocardial infarction (MI) surgery. By contrast, mice with genetic mitochondrial CaMKII inhibition are protected from left ventricular dilation and dysfunction after MI. Mice with myocardial and mitochondrial CaMKII overexpression (mtCaMKII) have severe dilated cardiomyopathy and decreased ATP that causes elevated cytoplasmic resting (diastolic) Ca2+ concentration and reduced mechanical performance. We map a metabolic pathway that rescues disease phenotypes in mtCaMKII mice, providing insights into physiological and pathological metabolic consequences of CaMKII signaling in mitochondria. Our findings suggest myocardial dilation, a disease phenotype lacking specific therapies, can be prevented by targeted replacement of mitochondrial creatine kinase or mitochondrial-targeted CaMKII inhibition.


Assuntos
Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Cardiomiopatia Dilatada/metabolismo , Infarto do Miocárdio/fisiopatologia , Animais , Cálcio/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/genética , Metabolismo Energético/genética , Metabolismo Energético/fisiologia , Insuficiência Cardíaca/metabolismo , Ventrículos do Coração/fisiopatologia , Camundongos , Camundongos Transgênicos , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Infarto do Miocárdio/cirurgia , Transdução de Sinais
14.
PLoS Comput Biol ; 16(9): e1008198, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32931495

RESUMO

Calcium imaging with fluorescent protein sensors is widely used to record activity in neuronal populations. The transform between neural activity and calcium-related fluorescence involves nonlinearities and low-pass filtering, but the effects of the transformation on analyses of neural populations are not well understood. We compared neuronal spikes and fluorescence in matched neural populations in behaving mice. We report multiple discrepancies between analyses performed on the two types of data, including changes in single-neuron selectivity and population decoding. These were only partially resolved by spike inference algorithms applied to fluorescence. To model the relation between spiking and fluorescence we simultaneously recorded spikes and fluorescence from individual neurons. Using these recordings we developed a model transforming spike trains to synthetic-imaging data. The model recapitulated the differences in analyses. Our analysis highlights challenges in relating electrophysiology and imaging data, and suggests forward modeling as an effective way to understand differences between these data.


Assuntos
Cálcio/metabolismo , Fenômenos Eletrofisiológicos/fisiologia , Modelos Neurológicos , Imagem Molecular/métodos , Neurônios , Potenciais de Ação/fisiologia , Animais , Lobo Frontal/citologia , Lobo Frontal/fisiologia , Camundongos , Neurônios/metabolismo , Neurônios/fisiologia , Imagem Óptica
15.
PLoS Biol ; 18(9): e3000873, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32966273

RESUMO

The inhibitory axonless olfactory bulb granule cells form reciprocal dendrodendritic synapses with mitral and tufted cells via large spines, mediating recurrent and lateral inhibition. As a case in point for dendritic transmitter release, rat granule cell dendrites are highly excitable, featuring local Na+ spine spikes and global Ca2+- and Na+-spikes. To investigate the transition from local to global signaling, we performed holographic, simultaneous 2-photon uncaging of glutamate at up to 12 granule cell spines, along with whole-cell recording and dendritic 2-photon Ca2+ imaging in acute juvenile rat brain slices. Coactivation of less than 10 reciprocal spines was sufficient to generate diverse regenerative signals that included regional dendritic Ca2+-spikes and dendritic Na+-spikes (D-spikes). Global Na+-spikes could be triggered in one third of granule cells. Individual spines and dendritic segments sensed the respective signal transitions as increments in Ca2+ entry. Dendritic integration as monitored by the somatic membrane potential was mostly linear until a threshold number of spines was activated, at which often D-spikes along with supralinear summation set in. As to the mechanisms supporting active integration, NMDA receptors (NMDARs) strongly contributed to all aspects of supralinearity, followed by dendritic voltage-gated Na+- and Ca2+-channels, whereas local Na+ spine spikes, as well as morphological variables, barely mattered. Because of the low numbers of coactive spines required to trigger dendritic Ca2+ signals and thus possibly lateral release of GABA onto mitral and tufted cells, we predict that thresholds for granule cell-mediated bulbar lateral inhibition are low. Moreover, D-spikes could provide a plausible substrate for granule cell-mediated gamma oscillations.


Assuntos
Potenciais de Ação , Sinalização do Cálcio , Dendritos/metabolismo , Bulbo Olfatório/metabolismo , Sódio/metabolismo , Animais , Cálcio/metabolismo , Feminino , Holografia , Técnicas In Vitro , Masculino , Ratos Wistar , Receptores de N-Metil-D-Aspartato/metabolismo
16.
Maturitas ; 140: 55-63, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32972636

RESUMO

Supplementation with calcium (Ca) and/or vitamin D (vitD) is key to the management of osteoporosis. Other supplements like vitamin K2 (VitK2) and magnesium (Mg) could contribute to the maintenance of skeletal health. This narrative review summarizes the most recent data on Ca, vitD, vitK2 and Mg supplementation and age-related bone and muscle loss. Ca supplementation alone is not recommended for fracture prevention in the general postmenopausal population. Patients at risk of fracture with insufficient dietary intake and absorption could benefit from calcium supplementation, but it needs to be customized, taking into account possible side-effects and degree of adherence. VitD supplementation is essential in patients at risk of fracture and/or vitD deficiency. VitK2 and Mg both appear to be involved in bone metabolism. Data suggest that VitK2 supplementation might improve bone quality and reduce fracture risk in osteoporotic patients, potentially enhancing the efficacy of Ca ± vitD. Mg deficiency could negatively influence bone and muscle health. However, data regarding the efficacy of vitK2 and Mg supplementation on bone are inconclusive.


Assuntos
Cálcio/uso terapêutico , Fraturas Ósseas/prevenção & controle , Magnésio/uso terapêutico , Osteoporose/prevenção & controle , Vitamina D/uso terapêutico , Vitamina K 2/uso terapêutico , Vitaminas/uso terapêutico , Animais , Suplementos Nutricionais , Humanos
17.
Environ Pollut ; 265(Pt A): 114695, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32806416

RESUMO

Mining causes extensive damage to aquatic ecosystems via acidification, heavy metal pollution, sediment loading, and Ca decline. Yet little is known about the effects of mining on freshwater systems in the Southern Hemisphere. A case in point is the region of western Tasmania, Australia, an area extensively mined in the 19th century, resulting in severe environmental contamination. In order to assess the impacts of mining on aquatic ecosystems in this region, we present a multiproxy investigation of the lacustrine sediments from Owen Tarn, Tasmania. This study includes a combination of radiometric dating (14C and 210Pb), sediment geochemistry (XRF and ICP-MS), pollen, charcoal and diatoms. Generalised additive mixed models were used to test if changes in the aquatic ecosystem can be explained by other covariates. Results from this record found four key impact phases: (1) Pre-mining, (2) Early mining, (3) Intense mining, and (4) Post-mining. Before mining, low heavy metal concentrations, slow sedimentation, low fire activity, and high biomass indicate pre-impact conditions. The aquatic environment at this time was oligotrophic and dystrophic with sufficient light availability, typical of western Tasmanian lakes during the Holocene. Prosperous mining resulted in increased burning, a decrease in landscape biomass and an increase in sedimentation resulting in decreased light availability of the aquatic environment. Extensive mining at Mount Lyell in the 1930s resulted in peak heavy metal pollutants (Pb, Cu and Co) and a further increase in inorganic inputs resulted in a disturbed low light lake environment (dominated by Hantzschia amphioxys and Pinnularia divergentissima). Following the closure of the Mount Lyell Co. in 1994 CE, Ca declined to below pre-mining levels resulting in a new diatom assemblage and deformed diatom valves. Therefore, the Owen Tarn record demonstrates severe sediment pollution and continued impacts of mining long after mining has stopped at Mt. Lyell Mining Co.


Assuntos
Ecossistema , Poluentes Químicos da Água/análise , Austrália , Cálcio , Monitoramento Ambiental , Sedimentos Geológicos , Tasmânia
18.
Zhonghua Shao Shang Za Zhi ; 36(8): 704-709, 2020 Aug 20.
Artigo em Chinês | MEDLINE | ID: mdl-32829609

RESUMO

Objective: To investigate the early changes in serum osteoprotegerin/receptor activator of nuclear factor-κB ligand (RANKL) and related indexes of calcium and phosphorus in severe burn patients. Methods: Thirty severe burn patients who met the inclusion criteria and were admitted to Tongren Hospital of Wuhan University & Wuhan Third Hospital within 8 hours post injury from June 2017 to December 2018 were recruited into severe burn group (24 males and 6 females, aged (38±13) years). Ten healthy volunteers with normal physical examination results in the Physical Examination Center of the same hospital in the same period of time were recruited into healthy control group (7 males and 3 females, aged (37±8) years). A prospective controlled study was conducted. The fasting venous blood of 5 mL was taken from each patient in severe burn group on post injury day (PID) 1, 7, 14, 21, and 28, respectively, and the fasting venous blood of 5 mL was taken from each volunteer in healthy control group. The serum osteoprotegerin, RANKL, 25 hydroxyvitamin D, and parathyroid hormone (PTH) levels were determined by enzyme-linked immunosorbent assay, and the RANKL/osteoprotegerin ratio was calculated. Serum albumin, serum calcium, and serum phosphorus levels were determined by bromocresol green method, methylthymol blue method, and phosphomolybdic acid method, respectively. Data were statistically analyzed with Fisher's exact probability test, analysis of variance for repeated measurement, Mann-Whitney U test, independent sample t test, and Bonferroni correction. Results: (1) The serum osteoprotegerin levels of patients in severe burn group on PID 1, 7, 14, 21, and 28 were 155.11 (102.91, 187.02), 170.07 (84.60, 196.86), 174.95 (59.09, 208.35), 190.01 (47.08, 214.52), and 188.85 (58.73, 223.13) pg/mL, respectively, which were significantly higher than 33.34 (28.59, 45.68) pg/mL of volunteers in healthy control group, Z=-3.436, -4.311, -3.248, -2.811, -4.217, P<0.01. The serum levels of RANKL of patients in severe burn group on PID 1, 7, 14, 21, and 28 were (1 869±791), (1 746±857), (1 781±713), (2 015±825), and (2 272±583) pg/mL, respectively, significantly higher than (49±16) pg/mL of volunteers in healthy control group, t=12.600, 10.844, 13.294, 13.041, 20.880, P<0.01. The ratios of RANKL/osteoprotegerin of patients in severe burn group on PID 1, 7, 14, 21, and 28 were 12.23 (8.10, 24.73), 11.40 (8.25, 16.96), 11.15 (6.91, 38.32), 12.98 (9.22, 49.68), and 13.91 (10.29, 40.68), respectively, which were significantly higher than 1.17 (0.91, 1.74) of volunteers in healthy control group, Z=-4.560, -4.529, -4.529, -4.560, -4.623, P<0.01. (2) The serum level of 25 hydroxyvitamin D of patients in severe burn group on PID 1 was significantly lower than that of volunteers in healthy control group (Z=-2.749, P<0.01). Compared with those of volunteers in healthy control group, the serum levels of albumin of patients in severe burn group on PID 1, 7, 14, 21, and 28 were significantly lower (t=-4.374, -7.689, -8.257, -7.651, -6.259, P<0.01), the serum levels of PTH were significantly elevated (Z=-4.685, -4.685, -4.685, -4.654, -4.685, P<0.01), and the serum levels of phosphorus were not changed significantly. The serum levels of calcium of patients in severe burn group on PID 1, 7, 14, and 21 were significantly lower than the level of volunteers in healthy control group (Z=-2.375, -3.455, -2.442, -2.016, P<0.05 or P<0.01). Conclusions: The serum osteoprotegerin, RANKL, RANKL/osteoprotegerin ratio, and PTH are increased, and the serum 25 hydroxyvitamin D, albumin, and calcium are decreased in the early stage of severe burn patients, which may be the mechanism leading to bone loss in patients.


Assuntos
Queimaduras , Adulto , Cálcio , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Osteoprotegerina , Fósforo , Estudos Prospectivos , Ligante RANK
19.
J Environ Sci (China) ; 96: 186-193, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32819693

RESUMO

A new calcium-modified and starch-stabilized ferromanganese binary oxide (Ca-SFMBO) sorbent was fabricated with different Ca concentrations for the adsorption of arsenic (As) and cadmium (Cd) in water. The maximum As(III) and Cd(II) adsorption capacities of 1% Ca-SFMBO were 156.25 mg/g and 107.53 mg/g respectively in single-adsorption systems. The adsorption of As and Cd by the Ca-SFMBO sorbent was pH-dependent at values from 1 to 7, with an optimal adsorption pH of 6. In the dual-adsorbate system, the presence of Cd(II) at low concentrations enhanced As(III) adsorption by 33.3%, while the adsorption of As(III) was inhibited with the increase of Cd(II) concentration. Moreover, the addition of As(III) increased the adsorption capacity for Cd(II) up to two-fold. Through analysis by X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR), it was inferred that the mechanism for the co-adsorption of Cd(II) and As(III) included both competitive and synergistic effects, which resulted from the formation of ternary complexes. The results indicate that the Ca-SFMBO material developed here could be used for the simultaneous removal of As(III) and Cd(II) from contaminated water.


Assuntos
Arsênico , Poluentes Químicos da Água , Purificação da Água , Adsorção , Cádmio , Cálcio , Concentração de Íons de Hidrogênio , Ferro , Cinética , Manganês , Óxidos , Amido , Água
20.
J Environ Manage ; 274: 111133, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32781362

RESUMO

Batch experiments were conducted to test the hypothesis that nitrate (NO3-) could be immobilized by biochar via adsorption of CaNO3+ to the negatively charged biochar surfaces. The results show that addition of soluble Ca in both aqueous and soil systems enabled NO3- retention by the biochar material. Increase in the added Ca enhanced the retention rate and the optimal NO3- retention was gained at a Ca/NO3 molar ratio of 2 for the aqueous system. For the soil system, the Ca/NO3 molar ratio required to attain the optimal NO3- retention was much greater due to competition of other soil-borne ligands and soil colloids for the available Ca. At the same level of added Ca, the amount of NO3- being retained tended to increase with increasing dose of the biochar. More NO3- was retained in the soil system than in the aqueous system at the same dosage level of biochar due to additional adsorption of CaNO3+ by negatively changed soil organic and inorganic colloids. The findings obtained from this study have implications for developing effective methods for reducing NO3- leaching from soils.


Assuntos
Cálcio , Poluentes do Solo/análise , Carvão Vegetal , Nitratos/análise , Solo
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