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1.
Chemosphere ; 262: 127879, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32781334

RESUMO

The collapse of the Fundão Dam, in Southeastern Brazil, caused about 50 million m³ of iron ore tailings to sluice down the mountain to Rio Doce, in what is considered the greatest environmental disaster in Brazilian history. The fluvial system received an intense and sudden mudflow that was transported for more than 650 km, before reaching the Atlantic Ocean. Because the area was already impacted by the mineral activities in the region, it becomes essential to evaluate the environmental conditions before the disaster to correctly assess the disaster real damage. This study compares the concentration of trace metals in the sediments of the Rio Doce alluvial plain, before and after the dam collapse, as well as the newly deposited iron ore tailings that became part of the sedimentary framework. The data indicate that the fine particles deposited have since been incorporated into the sandy river sediments. The cadmium and arsenic contents in the sediments increased to levels above the National Environment Council thresholds. The comparison between the levels of trace metals in the situations before and after disaster shows that the mining mud is the source of cadmium while the arsenic was present before the environmental disaster, and its concentration increased due to sediment remobilization. The iron ore tailings deposited on the alluvial sediments also affected the physical parameters since the formed ferruginous crusts waterproofed the ground surface and may, gradually, release toxic metals when exposed to weathering and river reworking.


Assuntos
Monitoramento Ambiental , Metais/análise , Mineração , Poluentes Químicos da Água/análise , Oceano Atlântico , Brasil , Desastres , Ferro , Compostos de Ferro , Minerais , Rios , Colapso Estrutural , Oligoelementos
2.
Chemosphere ; 262: 127861, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32791368

RESUMO

In this study, goethiete (α-FeOOH) -biochar (BC) composites were successfully developed from a co-precipitation reaction under alkaline conditions (pH = 11.93) and used as the adsorbent for phosphate recovery from urine. The morphology and crystallinity of α-FeOOH-BC composites were characterized by scanning electron microscopy and X-ray diffraction. α-FeOOH loaded BC was found to be amorphous. This may be caused by the Si residue in BC. The Elovich model and the Langmuir model fit better to the kinetic and isotherm results of α-FeOOH-600BC, respectively, indicating that phosphate adsorption is mainly a chemisorption and monolayer adsorption process. The α-FeOOH-600BC with amorphous structure showed higher adsorption capacity than crystalline α-FeOOH, and the maximum phosphate sorption capacity reached 57.39 mg g-1. Additionally, the extractable phosphate of this material was approximately 967.5 mg P·kg-1 suggesting the α-FeOOH-600BC after adsorption could be a promising alternative as a slow-phosphate-release fertilizer. Fourier-transform infrared and X-ray induced photoelectron spectroscopy results showed that the active sites of the adsorption of phosphate were the Fe-OH bonds that formed inner-sphere complexes (Fe-O-P).


Assuntos
Fertilizantes , Compostos de Ferro/química , Minerais/química , Fosfatos/química , Poluentes Químicos da Água/química , Adsorção , Carvão Vegetal , Cinética , Organofosfatos , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X , Zea mays
3.
Chemosphere ; 262: 127800, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32750592

RESUMO

This study aimed to determine the mineral profile of hair samples of free-ranging capybaras (Hydrochoerus hydrochaeris) in remnants of the Atlantic Forest located in the Northeast of Brazil, and to evaluate the effects of origin, gender and age of the animals on their mineral accumulation in hair. Twenty hair samples from animals of different areas, genders and ages were prepared using microwave-assisted digestion, employing 5 mL of HNO3 and 2.5 mL of H2SO4 for 100 mg of sample. Digestion efficiency was assessed by residual carbon content. The digested samples were analyzed by inductively coupled plasma optical emission spectrometry (ICP OES). Principal component analysis (PCA) was performed considering the composition data of 11 elements (Al, Ca, Cd, Co, Cr, Cu, Fe, K, Mn, Mo, and Na). The digestion method applied was efficient and the most abundant elements with their respective concentration ranges in mg kg-1 were Al (396-2746), Ca (36-3420), Fe (476-51180), K (115-4843), and Na (72-473). ANOVA and PCA differentiated among the capybaras regarding age (adults) and origin (A3), both associated with higher concentrations of Al, Cd, Fe, and K. Although a higher metal bioaccumulation was observed in adult animals, it is important to highlight that this result could have been affected by diet and physiological parameters. The results suggest that A3 was the most anthropized remnant area due to agricultural and urban influences. Multi-elemental determination in hair can be used as a non-invasive method to assess heavy metal contamination in capybaras.


Assuntos
Exposição Ambiental/estatística & dados numéricos , Roedores/metabolismo , Oligoelementos/metabolismo , Animais , Brasil , Florestas , Cabelo/química , Metais Pesados/análise , Micro-Ondas , Minerais/análise , Oligoelementos/análise
4.
Chemosphere ; 262: 127567, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32755692

RESUMO

Acid mine drainage (AMD) is recognized as a challenge encountered by mining industries globally. Cyclic mineralization method, namely Fe2+ oxidation/mineralization-residual Fe3+ reduction-resultant Fe2+ oxidation/mineralization, could precipitate Fe and SO42- present in AMD into iron hydroxysulfate minerals and greatly improve the efficiency of subsequent lime neutralization, but the current Fe0-mediated reduction approach increased the mineralization cycles. This study constructed a bacteria-driven biomineralization system based on the reactions of Acidithiobacillus ferrooxidans-mediated Fe2+ oxidation and Acidiphilium multivorum-controlled Fe3+ reduction, and utilized water-dropping aeration and biofilm technology to satisfy the requirement of practical application. The resultant biofilms showed stable activity for Fe conversion: the efficiency of Fe2+-oxidation, Fe-precipitation, and Fe3+-reduction maintained at 98%, 32%, and 87%, respectively. Dissolved oxygen for Fe-oxidizing bacteria growth was continuously replenished by water-dropping aeration (4.2-7.2 mg/L), and the added organic carbon was mainly metabolized by Fe-reducing bacteria. About 89% Fe and 60% SO42- were precipitated into jarosite mineral after five biomineralization cycles. Fe was removed via forming secondary mineral precipitates, while SO42- was coprecipitated into mineral within the initial three biomineralization cycles, and then mainly precipitated with Ca2+ afterwards. Fe concentration in AMD was proven to directly correlate with subsequent lime neutralization efficiency. Biomineralization for five cycles drastically reduced the amount of required lime and neutralized sludge by 75% and 77%, respectively. The results in this study provided theoretical guidance for practical AMD treatment based on biomineralization technology.


Assuntos
Ferro/análise , Poluentes Químicos da Água/análise , Acidiphilium , Acidithiobacillus , Ácidos , Bactérias/metabolismo , Biodegradação Ambiental , Biomineralização , Compostos de Cálcio , Compostos Férricos , Ferro/metabolismo , Minerais , Mineração , Óxidos , Sulfatos , Poluentes Químicos da Água/metabolismo
5.
Chemosphere ; 262: 127803, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32755694

RESUMO

Mine tailings pose a huge hazard for environmental and human health, and the establishment of vegetation cover is crucial to reduce pollutant dispersion for the surroundings. However, their hostile physicochemical conditions hamper plant growth, compromising phytoremediation strategies. This study aims to investigate the role of organo-mineral amendments and plant growth-promoting rhizobacteria (PGPR) on the improvement of mine tailings properties and Lolium perenne L. (ryegrass) growth. Plants were grown in mine tailings mixed with an agricultural soil (1:1), 10% compost, and supplied with two different inorganic amendments - rock phosphate (6%) or lime (3%), and inoculated with the rhizobacterial strains Advenellakashmirensis BKM20 (B1) and Mesorhizobium tamadayense BKM04 (B2). The application of organo-mineral amendments ameliorated tailings characteristics, which fostered plant growth and further enhanced soil fertility and microbial activity. These findings were consistent with the increase of total organic carbon levels, with the higher numbers of heterotrophic and phosphate solubilizing bacteria, and higher dehydrogenase and urease activities, found in these substrates after plant establishment. Plant growth was further boosted by PGPR inoculation, most noticeable by co-inoculation of both strains. Moreover, inoculated plants showed increased activities for several antioxidant enzymes (catalase, peroxidase, polyphenoloxidase, and glutathione reductase) which indicate a reinforced antioxidant system. The application of agricultural soil, compost and lime associated with the inoculation of a mixture of PGPR proved to enhance the establishment of vegetation cover, thus promoting the stabilization of Kettara mine tailings. Nonetheless, further studies are needed in order to confirm its effectiveness under field conditions.


Assuntos
Biodegradação Ambiental , Recuperação e Remediação Ambiental/métodos , Mesorhizobium/fisiologia , Desenvolvimento Vegetal , Poluentes do Solo/análise , Bactérias , Compostos de Cálcio , Lolium/crescimento & desenvolvimento , Minerais , Mineração , Óxidos , Solo/química
6.
Chemosphere ; 262: 127796, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32755695

RESUMO

The literature is sparse in terms of the effect of exercise on the pharmacokinetics of fluoride (F) in humans. In a 4-treatment repeated measures cross-over study, we investigated F pharmacokinetics following no exercise (control) and three exercise intensity conditions (light, moderate and vigorous) in healthy adults. At a pre-experimental session, 8 participants (18-30y) residing in a non-fluoridated-area, underwent a VO2 max test to guide the three exercise intensities for the experimental sessions. Participants were on a F-free regime one week before and throughout the four experimental weeks. We measured urinary F excretion (UFE), maximum plasma concentration (Cmax), lag time of Cmax (Tmax), and Area Under the Curve (AUC) for plasma F concentration against time, following F ingestion then no, light, moderate and vigorous exercise. Results showed no statistically significant difference in Tmax among all sessions; whereas Cmax for moderate exercise (226.2 ng/ml) was significantly higher than for no (27.0 ng/ml; p < 0.001), light (105.6 ng/ml; p = 0.016) and vigorous (94.2 ng/ml; p = 0.008) exercise. Mean AUC over 0-90 min following F ingestion was also significantly higher in moderate exercise than for no (p < 0.001), light (p = 0.004) and vigorous (p = 0.001) exercise. Mean UFE over 0-14h was 638.8, 718.7, 574.6 and 450.5  µg for no, light, moderate and vigorous exercise, with no statistically significant differences among different sessions. In conclusion, this human experimental study suggests that moderate exercise may increase the fraction of F absorbed systemically which is therefore available to produce a biological effect. Future studies should be conducted with larger samples, different age groups and using different F doses.


Assuntos
Poluentes Ambientais/metabolismo , Fluoretos/metabolismo , Adulto , Área Sob a Curva , Estudos Cross-Over , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Minerais
7.
Sci Total Environ ; 752: 141786, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-32890829

RESUMO

The formation and fallout of oil-related marine snow have been associated with interactions between dispersed oil and small marine particles, like phytoplankton and mineral particles. In these studies, the influences of phytoplankton species, mineral particle concentration, and oil concentration on the aggregation of oil in seawater (SW) were investigated. The experiments were performed in a low-turbidity carousel incubation system, using natural SW at 13 °C. Aggregation was measured by silhouette camera analyses, and oil compound group distribution and depletion by gas chromatography (GC-FID or GC-MS). Aggregates with median sizes larger than 500 µm in diameter were measured in the presence of dispersed oil and the phytoplankton species Thalassiosira rotula, Phaeocystis globosa, Skeletonema pseudocostatum, but not with the microalgae Micromonas pusilla. When mineral particles (diatomaceous earth) were incubated at different concentrations (5-30 mg/L) with dispersed oil and S. pseudocostatum, the largest aggregates were measured at the lower mineral particle concentration (5 mg/L). Since dispersed oil rapidly dilutes in the marine water column, experiments were performed with oil concentrations of from 10 mg/L to 0.01 mg/L in the presence of S. pseudocostatum and diatomaceous earth. Aggregates larger than 500 µm was measured only at the highest oil concentrations (10 mg/L). However, oil attachment to the marine particles were also measured at low oil concentrations (≤1 mg/L). Depletion of oil compound groups (n-alkanes, naphthalenes, PAHs, decalins) were measured at all oil concentrations, both in aggregate and water phases, with biodegradation as the expected main depletion process. These results showed that oil concentration may be important for oil-related marine snow formation, but that even oil droplets at low concentrations may attach to the particles and be transported by prevailing currents.


Assuntos
Poluição por Petróleo , Petróleo , Poluentes Químicos da Água , Sedimentos Geológicos , Minerais , Poluição por Petróleo/análise , Fitoplâncton , Água do Mar , Poluentes Químicos da Água/análise
8.
Nat Commun ; 11(1): 5068, 2020 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-33033251

RESUMO

The mineralized collagen fibril is the basic building block of bone, and is commonly pictured as a parallel array of ultrathin carbonated hydroxyapatite (HAp) platelets distributed throughout the collagen. This orientation is often attributed to an epitaxial relationship between the HAp and collagen molecules inside 2D voids within the fibril. Although recent studies have questioned this model, the structural relationship between the collagen matrix and HAp, and the mechanisms by which collagen directs mineralization remain unclear. Here, we use XRD to reveal that the voids in the collagen are in fact cylindrical pores with diameters of ~2 nm, while electron microscopy shows that the HAp crystals in bone are only uniaxially oriented with respect to the collagen. From in vitro mineralization studies with HAp, CaCO3 and γ-FeOOH we conclude that confinement within these pores, together with the anisotropic growth of HAp, dictates the orientation of HAp crystals within the collagen fibril.


Assuntos
Colágeno/química , Minerais/química , Orientação Espacial , Osso e Ossos/química , Criança , Colágeno/ultraestrutura , Cristalização , Durapatita/química , Elétrons , Feminino , Humanos , Modelos Moleculares , Tomografia , Difração de Raios X
9.
J Environ Qual ; 49(1): 50-60, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33016368

RESUMO

Gatifloxacin (GAT) is a new generation fluoroquinolone antibiotic and its adsorption onto iron minerals influenced by coexisting trace elements [e.g., Cu(II)] has not been well investigated. To evaluate the adsorption behavior of GAT and Cu(II) onto goethite and hematite, the complexation constants of GAT with Cu(II) were determined using potentiometric titration, and the effects of Cu(II) concentration and solution pH on GAT adsorption were investigated using batch experiments. It was observed that GAT adsorption was negatively correlated with molar concentration ratio of Cu(II) to GAT. In our experimental pH range (i.e., 3.0-10.8), the calculated main species involved in GAT adsorption were Cu(GAT± )2+ and Cu(GAT± )2 2+ under acidic to neutral conditions, and formation of Cu(GAT- )2 (s) facilitated the removal of GAT from solution under alkaline condition. The adsorption data were well fitted by the Freundlich model and showed high nonlinearity. In adsorption onto goethite, the primary interactions shifted from electrostatic repulsion to formation of goethite-Cu(II)-GAT ternary surface complexes with increase of GAT concentration. For hematite, electrostatic repulsion was the main inhibiting mechanism and became stronger with increase of Cu(II) concentration. Our findings suggest that it is necessary to consider the complexation between GAT and coexisting metal cations in evaluating its transport in soils rich in different iron minerals.


Assuntos
Gatifloxacina , Minerais , Adsorção , Compostos Férricos , Compostos de Ferro
10.
Shanghai Kou Qiang Yi Xue ; 29(3): 316-320, 2020 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-33043352

RESUMO

PURPOSE: To investigate the effect of autologous concentrated growth factor fibrin solution combined with Bio-Oss bone powder on mucosal healing and bone regeneration after oral implanted guided bone regeneration. METHODS: From October 2016 to December 2018, 83 patients with maxillary single anterior tooth loss and labial bone defect were treated, they were divided into two groups. Patients in the experimental group (42 cases) received autologous concentrated growth factor fibrin solution + Bio-Oss bone powder, while patients in the control group (41 cases) received Bio-Oss bone powder alone. The degree of mucosal healing, implant success, bone defect regeneration, pain and other complications were followed up 7 days, 6 weeks and 1 year after operation. The success rate and complications of the two groups were observed, as well as the differences of mucosal color, swelling degree, bleeding index, depth of probing, attachment loss, height of bone graft and thickness of bone formation were measured and recorded. Statistical analysis was performed using SPSS 25.0 software package. RESULTS: There was no significant difference in the success rate of implants between the two groups (95.24% vs 97.56%, P>0.05). The complication rate of the experimental group was significantly lower than that of the control group (2.38% vs 14.63%, P<0.05). The mucosal color and swelling degree scores of the experimental group were significantly lower than those of the control group [(0.65±0.03) points vs (2.01±0.15) points, (1.10±0.37) points vs (2.69±0.54) points, P<0.05], and the bleeding index, probing depth, and attachment loss were significantly lower than the control group [(0.35±0.05) vs (0.49±0.09), (3.39±0.62) mm vs (4.41±0.95) mm, (3.02±0.66) mm vs (5.31±0.91) mm, P<0.05], bone graft height and osteogenesis height were significantly higher than the control group [(2.61±0.50) mm vs (2.20±0.31) mm, (2.53±0.34) mm vs (2.02±0.27) mm, P<0.05]. The degree of postoperative pain in the experimental group was significantly lower than that in the control group(P<0.05). CONCLUSIONS: Rich self-concentrating growth factor fibrin solution combined with Bio-Oss bone powder can effectively promote mucosal healing and bone regeneration after oral implant-guided bone regeneration, and reduce postoperative pain and complications.


Assuntos
Substitutos Ósseos , Implantes Dentários , Regeneração Óssea , Fibrina , Humanos , Minerais
11.
Shanghai Kou Qiang Yi Xue ; 29(4): 414-417, 2020 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-33089293

RESUMO

PURPOSE: To investigate the effect of Bio-Oss bone powder combined with Heal-All Oral repair membrane and Bio-Oss collagen on site preservation during implantology. METHODS: A total of 26 cases were randomly divided into 2 groups. In Bio-Oss bone powder group (13 cases), the sockets were filled with Bio-Oss bone powder, covering with Heal-All Oral repair membrane on the surface. In Bio-Oss collagen group (13 cases), the sockets were filled with Bio-Oss collagen only. The changes in alveolar bone density,height,width and new bone contour were evaluated with cone-beam CT(CBCT) after site preservation. The data were analyzed with SPSS 17.0 software package. RESULTS: There was no significant difference in new bone contour between 2 groups(P>0.05). The changes in height, width and grey level of alveolar bone between the two groups were significantly different after 3 months of follow-up(P<0.01), but the curative effect was similar(P>0.05). CONCLUSIONS: There is no significant difference in the efficacy of site preservation between the two materials. However, the site preservation technique using collagen is simple, less invasive and less costly.


Assuntos
Implantes Dentários , Minerais , Extração Dentária , Osso e Ossos , Colágeno , Humanos
12.
Shanghai Kou Qiang Yi Xue ; 29(4): 427-430, 2020 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-33089296

RESUMO

PURPOSE: To investigate the effect of Bio-Oss bone powder combined with platelet-rich fibrin on bone mass after implantation-guided bone regeneration in alveolar bone defects. METHODS: One hundred and six patients with single anterior tooth loss and labial alveolar bone defect were selected for implant implantation and guided bone regeneration at the same time. Patients in the experimental group (n=53) were treated with Bio-Oss bone powder combined with platelet-rich fibrin and biofilm to guide bone regeneration, while patients in the control group(n=53) were treated with Bio-Oss bone powder combined with biofilm to guide bone regeneration. The success rate of implantation, complication rate, the thickness of labial bone wall and the regeneration of bone defect were observed. Statistical analysis was performed on the data using SPSS 25.0 software package. RESULTS: There was no significant difference in the success rate of implants between the two groups(96.23% vs 88.68%, P>0.05). The thickness of the labial bone wall of the experimental group 12 months after implantation was significantly higher than that of the control group[(2.72±0.43) mm vs(2.51±0.36) mm], and the thickness of the labial wall of the implant at different sites was significantly greater than that of the control group(P<0.05). Bleeding index [(0.32±0.02) vs (0.42±0.03)], depth of probing [(3.31±0.69) mm vs (4.32±0.95) mm], loss of attachment [(3.06±0.52) mm vs (5.24±1.35) mm] was significantly smaller in the experimental group than in the control group (P<0.05); bone graft height [(2.61±0.52) mm vs (2.31±0.35) mm], osteogenesis height [(2.59±0.32) mm vs (2.01±0.16) mm] was significantly greater in the experimental group than in the control group(P<0.05). There was no significant difference in the incidence of complications between the two groups(1.89% vs 5.66%, P>0.05). CONCLUSIONS: Bio-Oss bone powder combined with platelet-rich fibrin can reduce bone loss and promote bone defect regeneration after guided bone regeneration.


Assuntos
Substitutos Ósseos , Fibrina Rica em Plaquetas , Regeneração Óssea , Humanos , Minerais
13.
Nutrients ; 12(10)2020 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-33003648

RESUMO

The third coronavirus outbreak in the last two decades has caused significant damage to the world's economy and community health. The highly contagious COVID-19 infection has affected millions of people to date and has led to hundreds of thousands of deaths worldwide. Aside from the highly infectious nature of SARS-CoV-2, the lack of a treatment or vaccine has been the main reason for its spread. Thus, it has become necessary to find alternative methods for controlling SARS-CoV-2. For the present review, we conducted an online search for different available nutrition-based therapies for previously known coronavirus infections and RNA-based virus infections as well as general antiviral therapies. These treatments have promise for combating COVID-19, as various nutrients and minerals play direct and indirect roles in the control and prevention of this newly emerged viral infection. The patients' nutritional status with COVID-19 must be analyzed before administering any treatment, and nutritional supplements should be given to the affected individuals along with routine treatment. We suggest a potential interventional role of nutrients to strengthen the immune system against the emerging infection caused by COVID-19.


Assuntos
Infecções por Coronavirus/imunologia , Sistema Imunitário/efeitos dos fármacos , Minerais/farmacologia , Pneumonia Viral/imunologia , Oligoelementos/farmacologia , Vitaminas/farmacologia , Betacoronavirus , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/virologia , Suplementos Nutricionais , Humanos , Sistema Imunitário/fisiologia , Micronutrientes , Minerais/uso terapêutico , Estado Nutricional , Pandemias , Pneumonia Viral/tratamento farmacológico , Pneumonia Viral/virologia , Síndrome Respiratória Aguda Grave , Oligoelementos/uso terapêutico , Vitaminas/uso terapêutico
14.
Huan Jing Ke Xue ; 41(8): 3797-3803, 2020 Aug 08.
Artigo em Chinês | MEDLINE | ID: mdl-33124356

RESUMO

The increase in the surface ozone (O3) concentration causes air pollution, which has become a significant environmental issue that is of increasing concern. Ozone pollution not only directly harms human health, but also influences the agricultural ecosystem by impacting crop growth, which may then indirectly affect human health through food quality and the safety of agricultural products. The effects of O3 pollution on rice growth, yields, and mineral metal contents in grains were investigated through field experiments with increased O3 concentration treatment (remaining at 100 nL·L-1) in open top chambers (OTC). The crop growth and metal contents of two rice varieties were analyzed and compared. The results showed that the higher O3 concentration inhibited the photosynthesis of Nanjing 5055 and Yangdao 6 rice leaves, reduced the chlorophyll content and leaf area index, and subsequently led to a decline in the rice yield of 45.5% and 28.6%, respectively. However, compared with the natural control, the contents of most mineral metallic elements in the brown rice and glume of the harvested grains increased by 3.6%-19.8% and 3.9%-36.0%, respectively, thus resulting in a lack of essential trace elements or pollution of heavy metals; hence, the impact of O3 on rice food quality and safety requires a comprehensive evaluation.


Assuntos
Poluentes Atmosféricos , Oryza , Ozônio , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/toxicidade , Ecossistema , Humanos , Minerais , Ozônio/análise , Ozônio/toxicidade , Folhas de Planta/química
15.
Huan Jing Ke Xue ; 41(8): 3836-3845, 2020 Aug 08.
Artigo em Chinês | MEDLINE | ID: mdl-33124361

RESUMO

Drip irrigation and biochar amendment could affect the nitrogen form and transformation. Creating a deep understanding of the interacting effects of drip irrigation patterns and biochar on soil mineral nitrogen, as well as the key functional genes and microbial community involved in nitrogen transformation is helpful for improving facility agricultural management, increasing water and nitrogen use efficiency, and reducing the nitrate accumulation and groundwater pollution caused by nitrogen leaching. Four treatments [surface drip irrigation (D), insert drip irrigation (ID, insert depth 15 cm), surface drip irrigation +10 t·hm-2 of biochar (DB), and insert drip irrigation +10 t·hm-2 of biochar (IDB)] were conducted in a solar greenhouse, and non-rhizospheric and rhizospheric soils of pepper plants were studied. There was no effect of drip irrigation patterns and biochar on ammonium-nitrogen in the non-rhizospheric and rhizospheric soils. Compared with surface drip irrigation, insert drip irrigation decreased the nitrate-nitrogen concentration in the non-rhizosphere soil (P<0.05), but biochar addition weakened the difference. Biochar addition decreased the nitrate-nitrogen concentration in the rhizosphere soil under the same drip irrigation patterns. In the D treatment, biochar significantly decreased the number of copies of AOA, AOB, and nirK genes in the non-rhizospheric soil, and AOA gene copies in the rhizospheric soil (P<0.05); however, there was an increase in the number of copies of AOB and nirK genes in the rhizospheric soil of the D and ID treatments (P<0.05). Based on the structural equation model (SEM), in the non-rhizospheric and rhizospheric soils, pH and electrical conductivity were the environmental factors with the greatest influence on the ammonium-nitrogen and nitrate concentrations, respectively, and the gene copy number of AOB was the biotic factor with the greatest influence on the nitrate-nitrogen concentration. Based on PICRUSt, the γ-Proteobacteria contributed mostly to ammonia monooxygenase gene (K10945) expression, whereas the α-Proteobacteria, especially the rhizobia members, contributed mostly to nitrite reductase gene (K00368) expression. Biochar addition regulated the bacterial community structure that participated in K10945 gene expression in the non-rhizospheric soil and K00368 gene expression in the rhizospheric soil (P<0.05). Overall, biochar addition contributed more to nitrate-nitrogen and microbial mineral nitrogen-transformation processes in the agricultural soil than did the drip irrigation patterns.


Assuntos
Nitrogênio , Solo , Irrigação Agrícola , Carvão Vegetal , Minerais , Microbiologia do Solo
16.
Arch Osteoporos ; 15(1): 168, 2020 10 21.
Artigo em Inglês | MEDLINE | ID: mdl-33083846

RESUMO

BACKGROUND: Calcium is an essential mineral compound and one of the most abundant minerals in the human body. A long-term low calcium intake predisposes the bones to fractures, osteopenia, and osteoporosis. This study was conducted to assess calcium intake and knowledge of calcium-related information among healthcare students in King Saud bin Abdulaziz University for Health Sciences (KSAU-Hs). METHODS: This cross-sectional survey was conducted using a self-administered questionnaire that has been distributed as a soft copy of 289 participants aged 19 years or older and studied at KSAU-Hs. The questionnaire had three sections assessing demographical data, calcium knowledge, and calcium intake. The knowledge outcome variables were good and poor, and participants were categorized as good knowledge if they answer 11 or more of the 18 questions, while the intake outcome variables were sufficient and insufficient intake based on the Recommended Dietary Allowance (RDA) of 1000 mg. RESULTS: Among all variables, 91.7% of the participants were found to be having an insufficient intake, and 74% were classified to be poor knowledge. As for knowledge, the highest score under the "Good" category were females 32.7% compared to males 22.2%, P = 0.05. The average intake of calcium was 497 mg/day. In terms of sufficient calcium intake, males scored 11.9% compared to females who scored 1.9% with a P value of 0.00. CONCLUSION: The results of this study have shown that there are significantly insufficient calcium intake and poor knowledge about calcium among healthcare students. The results indicate the urge to improve calcium intake and calcium knowledge among the healthcare students.


Assuntos
Cálcio/administração & dosagem , Alimentos Fortificados , Estudantes/psicologia , Adulto , Estudos Transversais , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Masculino , Minerais , Inquéritos e Questionários , Universidades , Adulto Jovem
17.
Nat Commun ; 11(1): 5203, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-33060603

RESUMO

Ending all forms of hunger by 2030, as set forward in the UN-Sustainable Development Goal 2 (UN-SDG2), is a daunting but essential task, given the limited timeline ahead and the negative global health and socio-economic impact of hunger. Malnutrition or hidden hunger due to micronutrient deficiencies affects about one third of the world population and severely jeopardizes economic development. Staple crop biofortification through gene stacking, using a rational combination of conventional breeding and metabolic engineering strategies, should enable a leap forward within the coming decade. A number of specific actions and policy interventions are proposed to reach this goal.


Assuntos
Biofortificação/métodos , Engenharia Metabólica/métodos , Cruzamento , Produtos Agrícolas/genética , Países em Desenvolvimento , Abastecimento de Alimentos , Alimentos Fortificados , Saúde Global , Humanos , Desnutrição/prevenção & controle , Micronutrientes , Minerais , Oryza , Plantas/genética , Plantas Geneticamente Modificadas , Formulação de Políticas , Provitaminas , Desenvolvimento Sustentável/economia , Desenvolvimento Sustentável/tendências , Nações Unidas , Vitaminas
18.
Chemosphere ; 258: 127288, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32947659

RESUMO

The discharge of toxic elements from tailings soils in the aquatic environments occurs chiefly in the presence of indigenous bacteria. The biotic components may interact in the opposite direction, leading to the formation of a passivation layer, which can inhibit the solubility of the elements. In this work, the influence of jarosite on the bio-immobilization of toxic elements was studied by native bacteria. In batch experiments, the bio-immobilization of heavy metals by an inhibitory layer was examined in the different aquatic media using pure cultures of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans. A variety of analyses also investigated the mechanisms of metals bio-immobilization. Among different tests, the highest metal solubility yielded 99% Mn, 91% Cr, 95% Fe, and 78% Cu using A. ferrooxidans in 9KFe medium after ten days. After 22 days, these percentages decreased down to 30% Mn and about 20% Cr, Fe, and Cu, likely due to metal immobilization by biogenic jarosite. The formation of jarosite was confirmed by an electron probe micro-analyzer (EPMA), X-ray diffraction (XRD), and scanning electron microscope (SEM). The mechanisms of metal bio-immobilization by biogenic jarosite from tailings soil confirmed three main steps: 1) the dissolution of metal sulfides in the presence of Acidithiobacillus bacteria; 2) the nucleation of jarosite on the surface of sulfide minerals; 3) the co-precipitation of dissolved elements with jarosite during the bio-immobilization process, demonstrated by a structural study for jarosite. Covering the surface of soils by the jarosite provided a stable compound in the acidic environment of mine-waste.


Assuntos
Compostos Férricos/química , Substâncias Perigosas/análise , Sulfatos/química , Acidithiobacillus , Acidithiobacillus thiooxidans , Bactérias , Substâncias Perigosas/toxicidade , Metais Pesados , Minerais , Solubilidade , Sulfetos/química , Difração de Raios X
19.
Vet Clin North Am Food Anim Pract ; 36(3): 525-546, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32943305

RESUMO

Determining mineral status of production animals is important when developing an optimum health program. Nutrition is the largest expense in food animal production and has the greatest impact on health and productivity of the animals. Knowing the bioavailability of minerals in the diet is difficult. Evaluating fluid or tissues from animals is the optimum method to determine bioavailability. Evaluating the diet provides some information. Serum/blood or liver from the animal needs to be analyzed to determine bioavailability of vitamin and minerals in the diet. This article reviews how to sample and the function of these minerals in cattle.


Assuntos
Gado/metabolismo , Minerais/metabolismo , Ruminantes/metabolismo , Animais , Dieta/veterinária , Gado/sangue , Minerais/análise , Estado Nutricional , Ruminantes/sangue , Vitaminas/sangue , Vitaminas/metabolismo
20.
Ecotoxicol Environ Saf ; 205: 111345, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32961496

RESUMO

With the broadly application of antibiotics to treat infectious diseases in humans and animals, antibiotic contaminants such as tetracycline (TC) and ciprofloxacin (CIP) have been detected in soil environments, where iron oxide minerals and phosphate are ubiquitous. To date, the influence of phosphate on the adsorption behaviors of TC/CIP onto iron oxides is still poorly understood. In this study, the effects of phosphate on the adsorptions of TC and CIP onto iron oxide minerals were investigated. Adsorption isotherms showed that the adsorption affinities of TC and CIP onto the three iron oxide minerals were in the order of goethite > hematite > magnetite with or without phosphate, the trend was dominated by different surface area and amount of surface hydroxyl groups of iron oxide minerals. Meanwhile, TC contains more functional groups than CIP for bonding, which resulted in greater adsorption affinity of three iron oxides to TC than that to CIP. Interestingly, phosphate weakened TC adsorption, while enhanced CIP adsorption, on the three iron oxides. This observation was ascribed to that phosphate anion enhanced the surface negative charge of iron oxides, which reinforced the electrostatic repulsion between iron oxides and negatively charged TC, also reinforced the electrostatic attraction between iron oxides and positively charged CIP. Furthermore, the inhibitory effect of phosphate on TC adsorption was dramatically enhanced at high pH, while the promoting effect of phosphate on CIP adsorption was slightly changed with various pH. Our results highlight the importance of phosphate in exploring the environmental fate of antibiotics in natural environment.


Assuntos
Ciprofloxacino/química , Compostos Férricos/química , Tetraciclina/química , Adsorção , Antibacterianos , Óxido Ferroso-Férrico , Concentração de Íons de Hidrogênio , Compostos de Ferro , Minerais , Fosfatos , Solo , Poluentes do Solo
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