Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 14.543
Filtrar
1.
Inorg Chem ; 58(21): 14720-14727, 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31613605

RESUMO

Although alkaline earth metal cations play an important role in our daily life, little attention has been paid to the field of fast quantitative analysis of their content due to a lack of satisfactory precision and a fast and convenient means of detection. In this study, we have designed a set of molecular tweezers based on the calix[4]arene chemosensor L, which was found to exhibit high selectivity and sensitivity toward Ca2+, Sr2+, and Ba2+ (by UV-vis and fluorescence methods) with low detection limits of the order of 10-7 to 10-8 M and high association constants (of the order of 106). More significantly, sensor L not only can recognize Ca2+, Sr2+, and Ba2+ but also can further discriminate between these three cations via the differing red shifts in their UV-vis spectra (560 nm for L·Ca2+, 570 nm for L·Sr2+, and 580 nm for L·Ba2+ complex) which is attributed to their different atomic radii. A rare synergistic effect for the recognition mechanism has been demonstrated by 1H NMR spectroscopic titration. Sensor L constructed a high shielding field by the cooperation of Tris with alkaline earth metal ion after complex. Additionally, the presence of acetoxymethyl group in sensor L results in enhancement of cell permeability, and as a consequence, sensor L exhibited excellent sensing and imaging (in vivo) in living cells and in zebrafish.


Assuntos
Bário/análise , Cálcio/análise , Calixarenos/química , Metais Alcalinoterrosos/química , Imagem Óptica , Compostos Organometálicos/química , Fenóis/química , Estrôncio/análise , Animais , Sobrevivência Celular , Células HeLa , Humanos , Compostos Organometálicos/síntese química , Células Tumorais Cultivadas , Peixe-Zebra
2.
Nature ; 574(7776): 95-98, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31554969

RESUMO

Micronutrient deficiencies account for an estimated one million premature deaths annually, and for some nations can reduce gross domestic product1,2 by up to 11%, highlighting the need for food policies that focus on improving nutrition rather than simply increasing the volume of food produced3. People gain nutrients from a varied diet, although fish-which are a rich source of bioavailable micronutrients that are essential to human health4-are often overlooked. A lack of understanding of the nutrient composition of most fish5 and how nutrient yields vary among fisheries has hindered the policy shifts that are needed to effectively harness the potential of fisheries for food and nutrition security6. Here, using the concentration of 7 nutrients in more than 350 species of marine fish, we estimate how environmental and ecological traits predict nutrient content of marine finfish species. We use this predictive model to quantify the global spatial patterns of the concentrations of nutrients in marine fisheries and compare nutrient yields to the prevalence of micronutrient deficiencies in human populations. We find that species from tropical thermal regimes contain higher concentrations of calcium, iron and zinc; smaller species contain higher concentrations of calcium, iron and omega-3 fatty acids; and species from cold thermal regimes or those with a pelagic feeding pathway contain higher concentrations of omega-3 fatty acids. There is no relationship between nutrient concentrations and total fishery yield, highlighting that the nutrient quality of a fishery is determined by the species composition. For a number of countries in which nutrient intakes are inadequate, nutrients available in marine finfish catches exceed the dietary requirements for populations that live within 100 km of the coast, and a fraction of current landings could be particularly impactful for children under 5 years of age. Our analyses suggest that fish-based food strategies have the potential to substantially contribute to global food and nutrition security.


Assuntos
Pesqueiros , Peixes/metabolismo , Abastecimento de Alimentos , Internacionalidade , Micronutrientes/deficiência , Micronutrientes/metabolismo , Estado Nutricional , Animais , Teorema de Bayes , Cálcio/análise , Pré-Escolar , Proteínas na Dieta/análise , Ácidos Graxos Ômega-3/análise , Produtos Pesqueiros/análise , Produtos Pesqueiros/economia , Pesqueiros/economia , Peixes/classificação , Humanos , Lactente , Ferro/análise , Micronutrientes/análise , Selênio/análise , Vitamina A/análise , Zinco/análise
3.
Int J Nanomedicine ; 14: 5243-5256, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31409987

RESUMO

Background: Dentin hypersensitivity is a common negative oral condition that can be treated with dentifrice containing hydroxyapatite (HA). The study evaluated the effect of nano-HA dentifrice on plugging the dentinal tubules for an anti-sensitivity reaction compared to a dentifrice containing common-sized particles. Also, the adsorption capacity of different particle sizes of HA mixed in a dentifrice and which is the optimal particle size was considered. Methods: Fourty premolar dentine discs and fourty molar dentine discs were randomly divided into 4 groups: distilled water group, ordinary dentifrice group and 80, 300 nm HA dentifrice group. Each dentin disc was brushed with a dentifrice twice daily at 7600 rpm under 100 g force for 2 mins for 7 consecutive days and divided into two parts, half of the dentin disc was detected by the scanning electron microscope (SEM) and energy dispersive spectrometer (EDS), the other half was brushed with distilled water and observed by SEM. One milliliter dentifrice solution (80 nm HA dentifrice, 300 nm HA dentifrice, ordinary dentifrice) was added to 50 ml potassium dichromate solution for 1, 14, and 28 d. The residual Chromium (Cr6+) concentration in the supernatant was measured by the diphenylcarbon phthalocyanine hydrazine method. The elemental constitution in the precipitate was detected by EDS. The Kruskal-Wallis test was used to analyze surface mineralization and different plugging rates of dentinal tubules. The absorption capacity of dentifrices were also evaluated by the Kruskal-Wallis test. Results: The plugging rate in the HA dentifrice group was higher than that in the ordinary dentifrice group, and the 80 nm HA dentifrice group showed the best result. The atomic percentages of Ca and P of 80 nm dentifrice group on the surface of dentinal tubules were the highest. The 80 nm HA dentifrice group showed the best adsorption and stable effect of Cr6+, followed by the 300 nm HA dentifrice group. The 300 nm HA dentifrice and the ordinary dentifrice showed desorption phenomenon. Conclusions: The dentifrice containing HA, especially the 80 nm HA dentifrice, exerts good dentinal tubule occlusion and surface mineralization effect. This dentifrice was also a good adsorbent of Cr6+.


Assuntos
Cromo/isolamento & purificação , Dentifrícios/farmacologia , Dentina/efeitos dos fármacos , Durapatita/farmacologia , Tamanho da Partícula , Adsorção , Cálcio/análise , Humanos , Fósforo/análise , Espectrometria por Raios X , Água
4.
Aquat Toxicol ; 214: 105236, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31260825

RESUMO

Otolith consisting largely of calcium carbonate, fibrous and proteins, is vital for maintaining body balance and/or hearing of fish. The formation of otolith involves Ca2+ transport and deposition. In the present study, we investigated the effects of Cd2+ on otoliths development by using zebrafish embryos as model. The results showed that exposure to Cd2+ inhibited the utricular and saccular otoliths growth, indicated by reduced lateral areas. Swimming speeds were reduced and a losing balance control was observed in Cd2+ exposed larvae. The genes related to Ca2+ transport (e.g. plasma membrane Ca2+-ATPase isoform 2, pmca2; Ca2+-ATPase isoform 2, atp2b1a) and regulation (e.g. parathyroid hormone ligand type-1, pth1; stanniocalcin isoform 1, stc1) were significantly downregulated. However, the adverse effects of Cd2+ on otoliths growth and swimming activity can be protected by supplementation of Ca2+ in exposure medium. Body burden of Cd2+ in larvae was reduced upon the supplement with Ca2+. The overall results suggest that exposure to Cd2+ can inhibit influx of Ca2+, leading to less deposition of CaCO3 for otolith growth, and finally result in impaired balance control and swimming activity in zebrafish larvae.


Assuntos
Comportamento Animal , Cádmio/toxicidade , Exposição Ambiental , Membrana dos Otólitos/crescimento & desenvolvimento , Peixe-Zebra/fisiologia , Animais , Comportamento Animal/efeitos dos fármacos , Cálcio/análise , Larva/efeitos dos fármacos , Atividade Motora/efeitos dos fármacos , Membrana dos Otólitos/efeitos dos fármacos , Fatores de Tempo , Testes de Toxicidade , Transcrição Genética/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/embriologia , Peixe-Zebra/genética , Proteínas de Peixe-Zebra/genética
5.
Environ Sci Pollut Res Int ; 26(26): 27494-27504, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31332678

RESUMO

The reduction of wet desulfurization wastewater is one of the important tasks of coal-fired power plants, and it is important for achieving "zero emissions." Evaporation and concentration (E&C) with waste heat is an effective way to reduce wastewater. Here, two typical types of industrial desulfurization wastewater are used to study the change rule of pH and total dissolved solids during wastewater concentration in a circulating evaporation tower. The results indicate that with the increase of concentration ratio, the pH of desulfurization wastewater is decreased rapidly and then is gradually stabilized at 2-3 when SO2 or SO3 is contained in flue gas, and the increase in conductivity is less for wastewater with higher SO42- content. The characteristics of various ions are also analyzed, and the composition and microscopic morphology of the precipitates are characterized during concentration. The growth pattern of Ca2+ concentration is dependent on the ratio of Ca2+ and SO42- in raw wastewater. When the concentration ratio is 7.21, the insoluble and slightly soluble substances undergo precipitation and the solid content is approximately 20%, which can help realize the concentration and reduction of desulfurization wastewater.


Assuntos
Carvão Mineral , Centrais Elétricas , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/química , Cálcio/análise , Cálcio/química , Concentração de Íons de Hidrogênio , Enxofre/química , Dióxido de Enxofre/química , Temperatura Ambiente , Eliminação de Resíduos Líquidos/instrumentação
6.
Sci Total Environ ; 691: 178-186, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31319254

RESUMO

The leaves and seeds of plants frequently function as the source and sink organs for distinct metabolites, which can interactively vary in response to adverse site conditions. Subtropical soils are typically characterized as having deficient phosphorus (P), calcium (Ca), and magnesium (Mg), with enriched aluminum (Al) and iron (Fe), while Al and manganese (Mn) are toxic at low pH. It remains largely unknown how leaf- and seed-sourced metabolites are synergistically linked to adapt to P-variable soils for trees in subtropical areas. Here we quantified the metabolic and elemental profiling in the mature leaves and immature seeds of Quercus variabilis at contrasting geologically-derived phosphorus sites in subtropical China. The results revealed that carbon (C) and nitrogen (N) based metabolites (primarily sugars and organic acids), as well as enzyme- and protein/nucleic acid-related elements (N, P, Mg, and Mn) played important roles toward characterizing the profiling of metabolites and ionomes in leaves and seeds at two site types, respectively. These metabolites (sugars, amino acids, and fatty acids) and elements (N, P, Mg, and Mn) of seeds were closely related to the sugars, organic acids, and elements (N, P, Mg, and Mn) of leaves at the two site types. For the most part, the content of N and P in the soil affected the accumulation of materials (such as, starchs and proteins) in seeds, as well as N and P assimilation in leaves, by influencing C- and N-containing metabolites in leaves. These results suggested that correlated disparities of C- and N-containing metabolites, along with enzyme- and protein/nucleic acid-related elements in both leaves and seeds played important roles in plants to facilitate their adaptation to nutrient-variable sites in subtropical zones.


Assuntos
Monitoramento Ambiental , Fósforo/análise , Folhas de Planta/metabolismo , Quercus/fisiologia , Sementes/metabolismo , Oligoelementos/análise , Alumínio/análise , Cálcio/análise , Carbono/análise , China , Magnésio/análise , Manganês/análise , Minerais/análise , Nitrogênio/análise , Folhas de Planta/química , Potássio/análise , Quercus/química , Sementes/química , Solo/química
7.
J Dairy Sci ; 102(8): 6830-6841, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31155267

RESUMO

Natural variations among milk constituents, and their relations to each other as well as to processing parameters, represent possibilities for differentiation of milk to produce high-quality natural products. In this study, we focused on natural variations in milk citrate and its interplay with calcium distribution in milk, in relation to processing properties. Milk samples from individual cows from farms varying in feeding and management practices were collected from April to June 2017 to maximize natural variations in citrate and calcium. Chemical composition, rennet coagulation properties, and ethanol stability were analyzed for all milk samples. We focused particularly on calcium distribution and citrate content and the correlation of these to other milk parameters. No significant change in citrate content was observed during the sampling period, which suggests that mechanisms other than feeding affect citrate levels in milk. Several significant correlations were found, including a positive correlation between complexed serum calcium and citrate, and a negative correlation between urea and ionic calcium. These are both of interest in relation to further processing, as with regard to the stability of UHT milk and in cheese making. Although the correlation between complexed serum calcium and citrate may be explained by their affinity, the underlying driver for the negative relationship between natural milk urea and ionic calcium needs to be clarified by further studies. Furthermore, milk from the different farms varied not only with regard to organic versus conventional farming systems; feeding practices between farms also play an important role in milk composition and functionality. However, none of the differences in milk composition between farms were found to decrease milk functionality and thus would probably not cause any processing problems.


Assuntos
Cálcio/análise , Ácido Cítrico/análise , Manipulação de Alimentos/métodos , Leite/química , Animais , Cálcio na Dieta/análise , Bovinos , Queijo/análise , Quimosina/metabolismo , Citratos , Fazendas , Feminino , Minerais/análise , Agricultura Orgânica/métodos
8.
J Anim Sci ; 97(7): 2927-2939, 2019 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-31150088

RESUMO

A study was conducted to evaluate the effects of feeding an acidogenic diet with a low dietary cation-anion difference (DCAD) on acid-base balance, blood, milk, and urine Ca concentrations of sows during lactation. A total of 30 multiparous sows (parity: 4.5 ± 2.9, Smithfield Premium Genetic, Rose Hill, NC) were allotted to 1 of 2 dietary treatments: CON (control diets were corn-soybean meal based with a calculated DCAD of 170 and 226 mEq/kg during late gestation and lactation, respectively) or ACI (acidogenic diets had a DCAD 100 mEq/kg lower than the control diets). The lower DCAD was achieved by the addition of an acidogenic mineral. The DCAD was calculated as mEq (Na + K - Cl)/kg diet. Sows had a daily access to 2-kg feed from day 94 of gestation to parturition and ad libitum access to feed during lactation. Blood and urine pH and Ca, serum macrominerals, serum biochemistry, Ca-regulating hormones, and milk composition were measured. Sows in ACI had a lower (P < 0.05) blood pH than sows in CON at day 1 of lactation. Sows in ACI had a lower (P < 0.05) urine pH at day 108 of gestation, days 1, 9, and 18 of lactation compared with sows in CON. Sows in ACI had greater (P < 0.05) concentrations of serum total Ca at days 1 and 18 of lactation than sows in CON. There was a greater (P < 0.05) concentration of colostrum Ca in ACI than in CON. There was no difference in urine Ca concentration between treatments during lactation. Concentrations of parathyroid hormone and 1,25-dihydroxycholecalciferol were not different between treatments at either day 1 or 18 of lactation. Sows in ACI tended to have a smaller (P = 0.086) concentration of total alkaline phosphatase in serum at day 18 of lactation compared with sows in CON. At day 1 of lactation, the concentration of serum Cl in ACI was greater (P < 0.05) than that in CON. Feed intake, BW loss, and litter performance were not different between treatments. Collectively, feeding an acidogenic diet with a low DCAD to sows can induce a mild metabolic acidosis at farrowing, reduce the urine pH consistently, and increase serum total Ca and colostrum Ca concentrations during lactation but without altering the parathyroid hormone and 1,25-dihydroxycholecalciferol levels during lactation.


Assuntos
Ração Animal/análise , Cálcio/análise , Colostro/química , Leite/química , Minerais/análise , Suínos/sangue , Equilíbrio Ácido-Base , Animais , Ânions/análise , Cátions/análise , Dieta/veterinária , Feminino , Lactação , Paridade , Parto , Gravidez
9.
Environ Monit Assess ; 191(7): 440, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-31203473

RESUMO

Production of quality jute fibre primarily depends on the retting process of jute. However, the quality of retting water is of great concern because of the scarcity of available water bodies for retting. A study conducted on physico-chemical and microbiological changes in retting water (pre- and post-retting) from four intensively jute-growing districts namely Nadia, North 24 Parganas, Hooghly and South Dinajpur of West Bengal, India, during jute retting. The post-retting water samples recorded lower pH (6.22 to 7.08) and higher EC (electrical conductivity) (0.509 to 0.850 ds/m) compared with pre-retting water samples (pH 6.63 to 7.44; EC 0.197 to 0.330 ds/m) collected from all the four districts under study. The biological oxygen demand (BOD) and chemical oxygen demand (COD) increased several folds in the post-retting water samples indicating very high microbial growth and activities and depleted oxygen level compared with pre-retting water. The Ca + Mg (calcium + magnesium) content in pre-retting water was high (24.15 to 36.60 ppm) which raised further (61.30 to 103.67 ppm) in post-retting water, while the bicarbonate content also increased and ranged between 2.72 and 6.81 me/l in post-retting water compared with its status in pre-retting water (1.30 to 3.15 me/l). The post-retting water was found to be a rich source of nutrients like nitrogen (N), phosphorus (P), iron (Fe), manganese (Mn), zinc (Zn) and copper (Cu) which increased substantially because of jute retting as compared with their status in pre-retting water. The population of pectinolytic, xylanolytic, cellulolytic and ligninolytic bacterial cfu (colony forming unit) increased by 1.5 times in post-retting water as compared with pre-retting water, because these specific bacterial population were involved in the degradation of pectin, xylan, cellulose and lignin during retting of jute. Thus, post-retting water can be judiciously used as a potent source of primary, secondary and micronutrients for succeeding crops besides having higher BOD and COD as a result of higher microbial growth related to jute retting.


Assuntos
Bactérias/metabolismo , Corchorus/metabolismo , Lignina/metabolismo , Água/metabolismo , Bicarbonatos/análise , Cálcio/análise , Celulose , Monitoramento Ambiental , Índia , Magnésio/análise , Oxigênio/metabolismo
10.
Mater Sci Eng C Mater Biol Appl ; 102: 200-211, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31146991

RESUMO

Alumina-titanium composites have shown good mechanical properties which makes them promising for orthopedic applications. The placement of an orthopedic implant involves an invasive procedure which stimulates a localized inflammatory response causing an acidic environment around the implant. This makes the study on corrosion more critical. Therefore, the aim of the present paper was to study the corrosion behavior of the composites with 75 vol% and 50 vol% Ti content (with alumina balance) fabricated by Spark Plasma Sintering under acidic condition representing inflammation and in two elapsed times (1 h and 1-day) using polarization and electrochemical impedance spectroscopy tests. For comparison, the experiments were also conducted in normal physiological solution after 1 h, and pure Ti (100vol%Ti) was fabricated by the same process and analyzed, similarly. Furthermore, behavior of the samples was studied after 48 days of immersion in the acidic and normal solutions using SEM, ATR-FTIR, AFM, and ICP-OES. The results of corrosion tests showed very good passivation behavior of 100vol%Ti and the composite containing 75vol.%Ti. The superiority of the 75vol.%Ti composite in corrosion characteristics in both solutions was also found. Its corrosion resistance was 20.3 MΩcm2 under the inflammatory condition after 1-day, which was 39% higher than that of 100vol.%Ti under the same condition. The results of SEM indicated both corroded and mineral deposition zones on all materials' surfaces and the ATR-FTIR results revealed additional adsorbed bands related to water adsorption, OH and carbonate groups after immersion. The AFM analysis showed rougher morphology, particularly for 75 vol% Ti where the Rq was increased about 50 nm, and the ICP-OES results indicated 65.87% and 61.94% deposition of solution calcium on 75vol.%Ti and 50vol.%Ti, respectively. The acidic/inflammatory condition influenced the corrosion processes of all materials. Lower pH caused the passivation to occur sooner and the corrosion resistance to be higher.


Assuntos
Óxido de Alumínio/química , Inflamação/patologia , Titânio/química , Cálcio/análise , Corrosão , Espectroscopia Dielétrica , Eletroquímica , Concentração de Íons de Hidrogênio , Soluções , Espectroscopia de Infravermelho com Transformada de Fourier
11.
J Sci Food Agric ; 99(13): 5918-5925, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31206684

RESUMO

BACKGROUND: Artificial intelligence systems have been employed for the development of predictive models that estimate many agricultural processes. RESULTS: In present study, the predictive capabilities of artificial neural networks (ANNs) were evaluated with respect to assessing fruit firmness as a postharvest life index, with determinations made at four stages of storage: 1, 60, 120 and 180 days after harvesting. Single concentrations of nitrogen (N), potassium (K), calcium (Ca) and magnesium (Mg) on fruit (D1 ), all of these nutrient concentrations (D2 ), the ratios of the nutrient concentrations alone (D3 ), and a combination of nutrient concentrations and their ratios (D4 ), were considered. CONCLUSION: The results obtained showed that fruit firmness at 1 and 60 days after harvesting was not influenced by nutrients. However, the ANN model estimated fruit firmness of 120 and 180 days, respectively, for D1 and D3 more accurately than for the D2 and D4 datasets. Application of D3 (nitrogen/calcium ratio) as the input dataset improved predictions of fruit firmness, with a correlation coefficient of 0.85 between the measured and estimated data. © 2019 Society of Chemical Industry.


Assuntos
Actinidia/química , Frutas/crescimento & desenvolvimento , Magnésio/análise , Redes Neurais (Computação) , Actinidia/crescimento & desenvolvimento , Cálcio/análise , Frutas/química , Nitrogênio/análise , Potássio/análise
12.
Mater Sci Eng C Mater Biol Appl ; 102: 1-11, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31146979

RESUMO

For tissue engineering applications, a porous scaffold with an interconnected network is essential to facilitate the cell attachment and proliferation in a three dimensional (3D) structure. This study aimed to fabricate the scaffolds by an extrusion-based 3D printer using a blend of polycaprolactone (PCL), and graphene oxide (GO) as a favorable platform for bone tissue engineering. The mechanical properties, morphology, biocompatibility, and biological activities such as cell proliferation and differentiation were studied concerning the two different pore sizes; 400 µm, and 800 µm, and also with two different GO content; 0.1% (w/w) and 0.5% (w/w). The compressive strength of the scaffolds was not significantly changed due to the small amount of GO, but, as expected scaffolds with 400 µm pores showed a higher compressive modulus in comparison to the scaffolds with 800 µm pores. The data indicated that the cell attachment and proliferation were increased by adding a small amount of GO. According to the results, pore size did not play a significant role in cell proliferation and differentiation. Alkaline Phosphate (ALP) activity assay further confirmed that the GO increase the ALP activity and further Elemental analysis of Calcium and Phosphorous showed that the GO increased the mineralization compared to PCL only scaffolds. Western blot analysis showed the porous structure facilitate the secretion of bone morphogenic protein-2 (BMP-2) and osteopontin at both day 7 and 14 which galvanizes the osteogenic capability of PCL and PCL + GO scaffolds.


Assuntos
Grafite/farmacologia , Poliésteres/química , Impressão Tridimensional , Tecidos Suporte/química , Fosfatase Alcalina/metabolismo , Animais , Cálcio/análise , Adesão Celular/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Força Compressiva , Camundongos , Osteoblastos/citologia , Osteoblastos/efeitos dos fármacos , Osteoblastos/ultraestrutura , Fósforo/análise
13.
Adv Neurobiol ; 22: 207-231, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31073938

RESUMO

In the last two decades, increasing research efforts in neuroscience have been focused on determining both structural and functional connectivity of brain circuits, with the main goal of relating the wiring diagram of neuronal systems to their emerging properties, from the microscale to the macroscale. While combining multisite parallel recordings with structural circuits' reconstruction in vivo is still very challenging, the reductionist in vitro approach based on neuronal cultures offers lower technical difficulties and is much more stable under control conditions. In this chapter, we present different approaches to infer the connectivity of cultured neuronal networks using multielectrode array or calcium imaging recordings. We first formally introduce the used methods, and then we will describe into details how those methods were applied in case studies. Since multielectrode array and calcium imaging recordings provide distinct and complementary spatiotemporal features of neuronal activity, in this chapter we present the strategies implemented with the two different methodologies in distinct sections.


Assuntos
Sinalização do Cálcio , Cálcio/análise , Eletrodos , Eletrofisiologia/instrumentação , Eletrofisiologia/métodos , Vias Neurais , Neurônios/citologia , Neurônios/metabolismo , Encéfalo/citologia , Encéfalo/metabolismo , Humanos
14.
Medicina (Kaunas) ; 55(5)2019 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-31126169

RESUMO

BACKGROUND AND OBJECTIVES: Uremic encephalopathy is the most important complication of renal failure and urgent dialysis treatment is required. Parathormone (PTH) contributes to the etiopathogenesis of uremic encephalopathy. PTH is a hormone that acts in the calcium balance in the organism. The aim of our study was to investigate the effect of serum adjusted and ionized calcium on the development of uremic encephalopathy in patients with acute renal injury (acute kidney injury network (AKIN) stage 3). MATERIALS AND METHODS: Our study was supported by Canakkale Onsekiz Mart University Scientific Research Projects Unit (ID:1278). Three groups were formed for the study. The first group was acute renal failure AKIN stage 3 (N: 23), the second group was AKIN stage 3, and the patients who had emergency hemodialysis (N: 17) and the third group (N: 9) had AKIN stage 3 hemodialysis due to uremic encephalopathy. In these patient groups, 25-hydroxy vitamin D, PTH, calcium, albumin, urea, creatinine, and blood-gas-ionized calcium were observed in their serum during the first application. Calcium, albumin, urea, creatinine, and ionized calcium in blood gas were also examined in serum at 24th and 72th hours. Data were analyzed using SPSS version 19.0. Kruskal-Wallis test and Mann-Whitney U test were applied for the variables that did not comply with normal distribution. p < 0.005 was accepted statistically. RESULTS: A statistically significant difference was found between the measurement creatinine values at the 24th and 72th hours of admission in AKIN stage 3 patients who applied to the emergency department (p = 0.008). A statistically significant difference was found in the measured calcium values (p = 0.013). A statistically significant difference was found in the measured ionized calcium values (p = 0.035). CONCLUSIONS: In our study, the effect of ionized calcium level on uremic encephalopathy in serum creatinine, calcium, and blood gas in patients presenting with acute renal injury, AKIN stage 3, was significant, but studies with new and large groups are needed.


Assuntos
Lesão Renal Aguda/complicações , Encefalopatias/sangue , Cálcio/análise , Lesão Renal Aguda/sangue , Idoso , Idoso de 80 Anos ou mais , Encefalopatias/etiologia , Cálcio/sangue , Serviço Hospitalar de Emergência/organização & administração , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco
15.
J Trace Elem Med Biol ; 54: 175-182, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31109609

RESUMO

Inadequate micronutrient intake in childhood harms growth and development, and it is related to increased rates of morbidity and mortality. The aim of this study is to evaluate the dietary intake and prevalence of inadequate micronutrient intake in preschool children (1-4 years old) attending two-day care centers. To assess children's dietary micronutrient intake, 24-h duplicate diets (n = 64) were collected for one week-day, including everything the children ate and drank both at home and in kindergarten. Anthropometric measurements were carried out to evaluate the children's nutritional status. The micronutrients copper, iron, calcium, magnesium, selenium, zinc, potassium, sodium, and manganese were determined by inductively coupled plasma mass spectrometry or graphite furnace atomic absorption spectrometry. Calcium and selenium were found with high inadequate intake rates: 50% and 42%, respectively, for children aged 1-3 years old, and 93% and 90% for children aged 4 years. Potassium was consumed in very low amounts, 13% and 5% of children aged 1-3 and 4 years old, respectively, achieved the adequate intake for the nutrient. Sodium intakes were excessive: 23% of the 1-3-year old and 42% of the 4-year-old children, respectively, had an intake higher than the tolerable upper levels. Regarding the nutritional status, overweight and obesity prevalence was 17%. Therefore, considering the damaging health effects for children of micronutrient deficiency and overweight and obesity status, it is necessary that government authorities be aware and update public policies and educational programs in order to promote healthy eating habits in early childhood.


Assuntos
Espectrometria de Massas/métodos , Brasil , Cálcio/análise , Fenômenos Fisiológicos da Nutrição Infantil , Pré-Escolar , Estudos Transversais , Dieta , Feminino , Humanos , Lactente , Magnésio/análise , Masculino , Micronutrientes/análise , Estado Nutricional , Potássio/análise , Selênio/análise , Sódio/análise , Espectrofotometria Atômica , Zinco/análise
16.
J Trace Elem Med Biol ; 54: 62-68, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31109622

RESUMO

BACKGROUND: Platinum-based anticancer drugs are relatively successful chemotherapeutic agents, which can cause significant elemental changes in key organs and are known for undesirable side effects, such as nephrotoxicity (damage to the kidneys). OBJECTIVES AND METHODS: Inductively coupled plasma mass spectrometry (ICP-MS) and traditional statistical tools such as two-sample Student's t-test and Pearson's correlation analysis are used to evaluate the effects of different investigational Pt-based anticancer drugs on the elemental constitution of kidneys and liver of mice. Principal component analysis is used to uncover relationships in element concentration and potential correlations between those and clinical effects. Random forest importance is used to identify elements most associated with the drug's maximum tolerated doses (MTDs). RESULTS: Strong negative correlations between Pt and both Cu (-0.814) and Zn (-0.784) in kidneys were observed for one of the Pt-acridine anticancer agents evaluated (Drug C). Strong positive correlations were observed between Cu in both kidneys (0.834) and liver (0.756) with Zn in liver for the same compound. Cisplatin administration correlates to higher concentrations of Ca, Cu, Rb and Zn in liver. Calcium and Mo in kidneys and Pt and Zn in liver are the features most associated with MTDs. CONCLUSIONS: The results indicate that the Pt-based agents investigated are major modulators of ion homeostasis in excretory organs, which most likely contributes to their systemic toxicity and limits their efficacy. A better understanding of subtle patterns and correlations among elements in key organs may provide deeper insights into the mechanisms of action and ultimately contribute for better, safer drugs. To achieve this goal, researchers involved in cancer drug development may leverage the high sensitivity and high sample throughput of ICP-MS, and the capabilities of modern statistical tools to extract relevant information from a large dataset.


Assuntos
Antineoplásicos/farmacologia , Rim/efeitos dos fármacos , Rim/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Oligoelementos/análise , Animais , Cálcio/análise , Cobre/análise , Espectrometria de Massas , Camundongos , Análise de Componente Principal , Rubídio/análise , Zinco/análise
17.
J Trace Elem Med Biol ; 54: 79-97, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31109624

RESUMO

BACKGROUND: Kashin-Beck disease (KBD) is a serious chronic osteochondral disease that is endemic in humans. Selenium (Se) has been considered in hypotheses of the aetiology of KBD, but few studies have explored the relationship between other elements and KBD. OBJECTIVE: This study explored the relationship between 39 elements and KBD. METHODS: In this retrospective study, 150 boys aged 6 to 14 years were randomly selected from a total population of 1,214 children. Subjects from endemic areas were divided into five groups: (KBD -Bin, N = 30; KBD + Se-Yongshou, N = 30; Control -Bin, N = 30; Control + Se -Yongshou, N = 30; and Control External -Chang'an, N = 30). Samples of occipital hair were collected from each subject, and thirty-nine elements, including 15 toxic elements, 19 nutrient elements, and 5 other elements were assayed by inductively coupled plasma mass spectrometry (ICP-MS). Correlation analysis of the elements in each group was performed by ggcorrplot (visualization of a correlation matrix using 'ggplot2') and PerformanceAnalytics packages in the program R Project. RESULTS: Among the 15 toxic elements, the levels of aluminum (Al) and bismuth (Bi) in the KBD -Bin were significantly higher than in the other groups, and the levels of silver (Ag), beryllium (Be), platinum (Pt), antimony (Sb), tin (Sn) and lead (Pb) in the KBD -Bin were significantly lower than in the other groups. Among the 19 nutrient elements, the levels of selenium (Se), iodine (I), sulfur (S), and boron (B) in the KBD -Bin were significantly lower than in the other groups. The levels of calcium (Ca), iron (Fe), manganese (Mn), chromium (Cr), strontium (Sr) and phosphorus (P) in the KBD -Bin were significantly higher than in the other groups. Correlations between various elements were remarkably different among the groups. There were positive correlations between As and Pb, Cd and Sb, Pb and Sb, Sb and U in the Control External -Chang'an, between Al and Ni, Cd and Pb, Tl and Ni, Ti and U in the Se-S KBD, and between B and I, B and Mo, Mn and V in the Control External -Chang'an. CONCLUSIONS: These findings indicate that the interactions between elements do not represent a simple reciprocal relationship in the occurrence of KBD. In fact, KBD was associated with an imbalance in multiple elements that play a dynamic and interactive role in the development of the disease.


Assuntos
Cabelo/química , Doença de Kashin-Bek/metabolismo , Oligoelementos/análise , Adolescente , Cálcio/análise , Criança , Cromo/análise , Humanos , Ferro/análise , Manganês/análise , Fósforo/análise , Estudos Retrospectivos , Selênio/análise , Titânio/análise
18.
J Trace Elem Med Biol ; 54: 98-102, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31109626

RESUMO

There is a need for effective medication against bone metastases because todays drugs are not able to penetrate the bone and reach the affected areas. To analyze if current or future platinum-containing drugs are able to achieve this, a quantitative imaging method is urgently needed. In this study, the platinum distribution in thin sections of mice tibia was determined using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) in a spatially resolved manner. The hard bone tissue visible in microscopic images and signals found for calcium and phosphorous recorded via LA-ICP-MS and micro X-ray fluorescence spectroscopy (µXRF) correlate well. Furthermore, the platinum concentration was quantified using polymer-based matrix-matched standards. A limit of detection of 6 µg/g and a linearity of almost three decades could be achieved. Concentrations surpassing 300 µg/g could be found in the tibia samples. The method presented herein is a powerful approach for the visualization and quantification of platinum. As such, this method is a valuable tool to unravel the mechanism of delivery and optimize the therapeutic potency of platinum-containing drugs targeting bone diseases like bone metastases.


Assuntos
Osso e Ossos/diagnóstico por imagem , Osso e Ossos/metabolismo , Espectrometria de Massas/métodos , Platina/análise , Animais , Cálcio/análise , Terapia a Laser , Camundongos , Espectrometria por Raios X
19.
Isotopes Environ Health Stud ; 55(3): 254-271, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31012329

RESUMO

Stable isotopes of water (δ2H, δ18O) and δ13CTIC were used as a tool to trace the recharge processes, natural carbon (organic and inorganic) source and dynamics in the aquifers of the central Gangetic basin, India. Stable isotope (δ2H, δ18O) record of groundwater (n = 105) revealed that the groundwater of Piedmont was recharged by meteoric origin before evaporation, while aquifers of the older and younger alluvium were recharged by water that had undergone evaporation loss. River Ganges and its tributaries passing through this area have very little contribution in recharging while ponds play no role in the recharging of adjacent aquifers. The connectivity of shallow aquifers of aquitard formation (comprised of clay/sandy clay with thin patches of fine grey sand), i.e. 25-60 m below ground level (bgl) with the main upper aquifer (at a depth of >120 m bgl) was found to be higher in older and younger alluvium. Negative values of δ13CTIC (median -9.6 ‰; range -13.2 to -5.4 ‰) and high TIC (median 35 mM; range 31-46 mM) coupled with low TOC (median 1.35 mg/L; range 0.99-1.77 mg/L) indicated acceleration in microbial activity in the younger alluvium, especially in the active floodplain of river Ganges and its proximity.


Assuntos
Isótopos de Carbono/análise , Deutério/análise , Água Subterrânea/análise , Isótopos de Oxigênio/análise , Bicarbonatos/análise , Cálcio/análise , Monitoramento Ambiental , Índia , Tanques/química , Rios/química
20.
Anal Chim Acta ; 1062: 28-36, 2019 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-30947993

RESUMO

Laser-induced breakdown spectroscopy (LIBS) is an appealing analytical technique for simultaneous multi-elemental analysis. Near-infrared spectroscopy (NIRS) has also been suggested for the same purpose, mainly for vegetable samples. However, LIBS has failed to provide adequate results in many cases due to sample matrix complexity, and NIRS performance is harmed because of its lack of sensitivity and indirect correlation with inorganic elemental species. In this work, the performance of these two techniques are compared for the determination of micro- and macroelements in vegetable samples (Brachiaria forages) using multivariate regression. In addition, a data fusion scheme, in which spectral data sourced by NIRS is integrated with LIBS, is proposed to improve elemental content determination in those samples. The information of the molecular composition detected by NIR vibrational spectroscopy was consistently selected by recursive partial least squares to yield quantitative multivariate models for K, Ca, Mg, Mn and Fe in forage plants that are superior to models based on the use of individual NIRS and LIBS spectral information. While all data fusion models showed better predictive accuracy than any of the two individual techniques, best results were observed for Ca. This suggests that matrix composition affects each element determination by LIBS distinctively and supports the idea that a successful quantitative data fusion strategy for LIBS requires a technique such as NIRS which is sensitive to this variability.


Assuntos
Brachiaria/química , Cálcio/análise , Ferro/análise , Magnésio/análise , Manganês/análise , Potássio/análise , Lasers , Análise Multivariada , Análise Espectral
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA