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1.
Chemosphere ; 353: 141597, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38432466

RESUMO

The contamination of creek sediments near industrially nuclear dominated site presents significant environmental challenges, particularly in identifying and quantifying potentially toxic metal (loid)s (PTMs). This study aims to measure the extent of contamination and apportion related sources for nine PTMs in alpine creek sediments near a typical uranium tailing dam from China, including strontium (Sr), rubidium (Rb), manganese (Mn), lithium (Li), nickel (Ni), copper (Cu), vanadium (V), cadmium (Cd), zinc (Zn), using multivariate statistical approach and Sr isotopic compositions. The results show varying degrees of contamination in the sediments for some PTMs, i.e., Sr (16.1-39.6 mg/kg), Rb (171-675 mg/kg), Mn (224-2520 mg/kg), Li (11.6-78.8 mg/kg), Cd (0.31-1.38 mg/kg), and Zn (37.1-176 mg/kg). Multivariate statistical analyses indicate that Sr, Rb, Li, and Mn originated from the uranium tailing dam, while Cd and Zn were associated with abandoned agricultural activities, and Ni, Cu, and V were primarily linked to natural bedrock weathering. The Sr isotope fingerprint technique further suggests that 48.22-73.84% of Sr and associated PTMs in the sediments potentially derived from the uranium tailing dam. The combined use of multivariate statistical analysis and Sr isotopic fingerprint technique in alpine creek sediments enables more reliable insights into PTMs-induced pollution scenarios. The findings also offer unique perspectives for understanding and managing aqueous environments impacted by nuclear activities.


Assuntos
Metais Pesados , Urânio , Cádmio , Zinco , Manganês , Níquel , Estrôncio , Lítio , Medição de Risco , China , Metais Pesados/análise , Monitoramento Ambiental/métodos , Sedimentos Geológicos
2.
Molecules ; 29(3)2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38338415

RESUMO

Tissue engineering is an interdisciplinary field of science that has been developing very intensively over the last dozen or so years. New ways of treating damaged tissues and organs are constantly being sought. A variety of porous structures are currently being investigated to support cell adhesion, differentiation, and proliferation. The selection of an appropriate biomaterial on which a patient's new tissue will develop is one of the key issues when designing a modern tissue scaffold and the associated treatment process. Among the numerous groups of biomaterials used to produce three-dimensional structures, hydroxyapatite (HA) deserves special attention. The aim of this paper was to discuss changes in the double electrical layer in hydroxyapatite with an incorporated boron and strontium/electrolyte solution interface. The adsorbents were prepared via dry and wet precipitation and low-temperature nitrogen adsorption and desorption methods. The specific surface area was characterized, and the surface charge density and zeta potential were discussed.


Assuntos
Boro , Hidroxiapatitas , Humanos , Hidroxiapatitas/química , Alicerces Teciduais/química , Durapatita , Materiais Biocompatíveis/química , Estrôncio/química , Propriedades de Superfície
3.
J Forensic Sci ; 68(6): 1856-1874, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37646362

RESUMO

Colombia faces the complex humanitarian challenges of locating approximately 100,000 missing persons and identifying thousands who are deceased. Identification is a difficult task in many cases, because the skeletonized bodies are deteriorated, missing person data are unavailable for comparison, and the provenance of the remains is often totally unknown. Isotopic analysis of human tissues (e.g., bone, hair, nails, and teeth) aid in the identification process of unknown individuals because they can provide valuable information on possible geographic origin. This project evaluated the isotopic variability of carbon (C), oxygen (O), strontium (Sr), and lead (Pb) in modern Colombian teeth according to city, department (a political designation similar to "state" in the US or Mexico), and one of four geographically determined regions of origin; and assessed its utility for human identification in Colombia. Isotopic data (O-C-Sr-Pb) were analyzed from modern Colombians originating from the cities of Bogotá, Cali, and Neiva (n = 95); and these data were compiled with published Colombian data of individuals mainly from the city of Medellín (n = 61). Results indicate a wide range and overlap of O-C-Sr-Pb isotopic distribution according to the defined categories. However, differences between coastal and lowland individuals are observed when using δ18 O values, and differences between mountainous regions are observed when using 87 Sr/86 Sr values. In addition, this study suggests that the usefulness of isotopic analysis for unidentified individuals in Colombia would be with assigning them geographically using the designations of North, Central Andes, Eastern Andes, or Southwest Andes versus making classifications at a city or department level.


Assuntos
Antropologia Forense , Estrôncio , Humanos , Colômbia , Estrôncio/análise , Oxigênio/análise , Carbono/análise , Chumbo/análise , Isótopos/análise , Isótopos de Estrôncio/análise
4.
Urolithiasis ; 51(1): 53, 2023 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-36930293

RESUMO

This study was aimed at investigating the impact of varying concentrations of strontium (Sr) on calcium (Ca) excretion via the urine and determine its impact on kidney stone formation. Twenty adult male Sprague Dawley rats weighing between 200 and 300 g were selected. The rats were randomly divided into four groups of five. One group was used as a control group while the other three groups were experimental. The diet of the rats was modulated over a 12 week period to investigate the impact of Sr on the urinary excretion of Ca. Urinary samples were collected every 2 weeks from the rats. The rats were fed water ad libitum. After the study the rats were euthanised and their kidneys harvested. Urine and kidney samples from the rats were analysed using Total Reflection X-Ray Fluorescence (TXRF). In the urine excretion of Ca increased with increased intake of Sr in the diet. Sr excretion via the urine also increased with increased dietary intake. There was a correlation of 0.835 at the significance level of 0.01 between Ca and Sr in the urine. However, for the kidneys, the varying concentration of Sr did not impact the retention of Ca in the kidneys. There was increased retention of Sr in the kidneys with increased dietary intake. In this study an increase of Sr in the diet resulted in an increase in urinary excretion of Ca.


Assuntos
Cálcio , Estrôncio , Ratos , Masculino , Animais , Cálcio/urina , Ratos Sprague-Dawley , Estrôncio/urina , Cálcio da Dieta , Rim
5.
J Mech Behav Biomed Mater ; 138: 105587, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36446181

RESUMO

The present work reports the effect of decellularized platelet-rich fibrin (dPRF) loaded strontium (Sr) doped porous magnesium phosphate (MgP) bioceramics on biocompatibility, biodegradability, and bone regeneration. Sustained release of growth factors from dPRF is a major objective here, which conformed to the availability of dPRF on the scaffold surface even after 7 days of in vitro degradation. dPRF-incorporated MgP scaffolds were implanted in the rabbit femoral bone defect and bone rejuvenation was confirmed by radiological examination, histological examination, fluorochrome labeling study, and micro-CT. µ-CT examination of the regained bone samples exhibited that invasion of mature bone in the pores of the MgP2Sr-dPRF sample was higher than the MgP2Sr which indicated better bone maturation capability of this composition. Quantifiable assessment using oxytetracycline labeling showed 73.55 ± 1.12% new osseous tissue regeneration for MgP2Sr-dPRF samples in contrast to 65.47 ± 1.16% for pure MgP2Sr samples, after 3 months of implantation. Histological analysis depicted the presence of abundant osteoblastic and osteoclastic cells in dPRF-loaded Sr-doped MgP samples as compared to other samples. Radiological studies also mimicked similar results in the MgP2Sr-dPRF group with intact periosteal lining and significant bridging callus formation. The present results indicated that dPRF-loaded Sr-doped magnesium phosphate bioceramics have good biocompatibility, bone-forming ability, and suitable biodegradability in bone regeneration.


Assuntos
Fibrina Rica em Plaquetas , Alicerces Teciduais , Animais , Coelhos , Porosidade , Regeneração Óssea , Magnésio/farmacologia , Estrôncio/farmacologia , Osteogênese
6.
Anal Chem ; 94(16): 6338-6346, 2022 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-35427118

RESUMO

A method using diffusive gradients in thin films (DGT) for the accurate quantification of trace-level (µg L-1) Sr and Pb concentrations and isotope ratios [δSRM 987(87Sr/86Sr) and δSRM 981(207Pb/206Pb)] in labile, bioavailable element fractions in soils is reported. The method is based on a novel poly(tetrafluoroethylene) (PTFE) membrane binding layer with combined di(2-ethyl-hexyl)phosphoric acid (HDEHP) and 4,4'(5')-bis-t-butylcyclohexano-18-crown-6 (crown-ether) functionality with high selectivity for Sr and Pb (TK100 membrane). Laboratory evaluation of the TK100 DGT showed linear uptake of Sr over time (2-24 h) up to very high Sr mass loadings on TK100 membranes (288 µg cm-2) and effective performance in the range of pH (3.9-8.2), ionic strength (0.001-0.1 mol L-1), and cation competition (50-160 mg L-1 Ca in a synthetic soil solution matrix) of environmental interest. Selective three-step elution of TK100 membranes using hydrochloric acid allowed us to obtain purified Sr and Pb fractions with adequate (≥75%) recovery and quantitative (≥96%) matrix reduction. Neither DGT-based sampling itself nor selective elution or mass loading effects caused significant isotopic fractionation. Application of TK100 DGT in natural soils and comparison with conventional approaches of bioavailability assessment demonstrated the method's unique capability to obtain information on Sr and Pb resupply dynamics and isotopic variations with low combined uncertainty within a single sampling step.


Assuntos
Poluentes do Solo , Solo , Monitoramento Ambiental/métodos , Isótopos , Chumbo/química , Poluentes do Solo/análise , Estrôncio/química
7.
Chemosphere ; 299: 134309, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35339528

RESUMO

Selective removal of radioactive strontium (90Sr) from the environment is important, and selective adsorption/ion exchange is appropriate for removal of trace amounts of 90Sr from large volumes of 90Sr-contaminated water. Although various inorganic ion-exchange materials, including zeolites, have been investigated intensively for removal of Sr2+ due to their excellent resistance to radiation and high ion-exchange capacity, their ion-exchange selectivity for Sr2+ is poor in the presence of competing ions such as Ca2+ and Mg2+. Here, sulfur-modified NaA zeolite (S-NaA) was prepared for low-cost, selective 90Sr removal because the elemental sulfur encapsulated in micropores provides additional Lewis acid-base interactions with Sr2+ during the Sr2+ ion-exchange. Our ion-exchange experiments revealed that S-NaA with 3 wt% sulfur (3 S-NaA) showed the highest Sr2+ selectivity among various S-NaAs containing up to 10 wt% sulfur because ion exchange involving bulky hydrated Sr2+ depends on the reduced micropore volume of S-NaA after sulfur loading. Most importantly, 3 S-NaA effectively and efficiently (>99.4%) removed 90Sr from groundwater containing 8.4 ppt 90Sr, demonstrating its excellent potential for practical application in the treatment of 90Sr-contaminated water.


Assuntos
Estrôncio , Zeolitas , Adsorção , Enxofre , Água
8.
Proc Inst Mech Eng H ; 236(5): 740-747, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35296167

RESUMO

The aim of this research was to assess a selection of radiopaque filler compounds for increasing radiopacity in a resin suitable for Polyjet multi-material 3D printing. A radiopaque resin has potential applications in medicine to produce patient-specific anatomical models with realistic radiological properties, training aids, and skin contacting components such as surgical or procedural guides that require visibility under fluoroscopy. The desirable filler would have a high level of radiopacity under ionising imaging modalities, such as X-ray, CT, fluoroscopy or angiography. Nine potential filler compounds were selected based on atomic number and handling risk: barium sulphate, bismuth oxide, zirconium oxide, strontium oxide, strontium fluoride, strontium carbonate, iodine, niobium oxide and tantalum oxide. The fillers were evaluated using selected criteria. A weighted material selection matrix was developed to prioritise and select a filler for future 3D printing on a multi-material 3D printer. Zirconium oxide was the highest scoring filler compound in the material selection matrix, scoring 4.4 out of a maximum of 5. MED610TM resin doped with zirconium oxide was shown to be UV curable, and when cured is non-toxic, environmentally friendly, and has the ability to display antimicrobial properties. In terms of radiopacity, a sample with thickness 1.5 mm of MED610™ resin doped with 20 wt.% zirconium oxide produced X-ray radiopacity equivalent to 3 mm of aluminium. Zirconium oxide was selected using the material selection matrix. This radiopaque resin can be used to produce anatomical models with accurate radiological properties, training aids or skin contacting devices that require visibility under ionising imaging modalities. The 3D printing validation run successfully demonstrated that the material selection matrix prioritised a filler suitable for radiopaque multi-material 3D printing.


Assuntos
Impressão Tridimensional , Humanos , Óxidos , Radiografia , Estrôncio
9.
Appl Radiat Isot ; 181: 110052, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35032841

RESUMO

86Y (t1/2 = 14.74 h, 32% ß+) has significant potential in theranostic applications as a simultaneous PET imaging partner to 90Y-labelled antibody therapy. However, the complex and costly nature of producing 86Y has led to this radiometal being difficult for hospitals and researchers to obtain. The aim of this work was to develop a simple and cost-efficient method for safely producing 86Y. Our approach was twofold: to develop a method of target preparation that would significantly increase the cost efficiency of producing 86Y, and to design and construct an automated purification system that would eliminate manual radiation handling risks and exposure. Multiple automated productions of high radionuclidic purity (99.45%) 86Y were performed resulting in saturation yields of between 518 MBq/µA and 1332 MBq/µA, dependent on target thickness.


Assuntos
Ciclotrons , Radioisótopos de Ítrio/química , Análise Custo-Benefício , Ciclotrons/economia , Tomografia por Emissão de Pósitrons , Pós , Radioquímica/economia , Radioquímica/métodos , Estrôncio , Radioisótopos de Ítrio/isolamento & purificação
10.
J Environ Manage ; 304: 114228, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34920286

RESUMO

Strontium (Sr) is an alkaline earth metal that has adverse effects on bone tissue, but received little attention compared to other often-studied metals. This study analyzed the contents/concentrations of Sr, barium (Ba), sulfate (SO42-), sulfide (S2-), and six common metals in 209 multi-media samples, including slag, soil, groundwater, surface water, and sediment, collected at a large Sr slag pile area. Sr was the dominant chemical of concern (COC) in the soil and groundwater, with contents/concentrations being 35.50-32200 mg/kg and 0.57-152 mg/L, respectively, much higher than those reported in previous research. Contents/concentrations of all COCs in the surface water and sediment were relatively low, except Sr content in the sediment near the slag pile. The LogKd value of Sr was calculated to be lower than those of common metals, indicating relatively high mobility of Sr in the aquatic environment. Contamination assessment using Nemerow index indicated near half of the soil and groundwater sampling locations, especially those within and near the slag pile, were heavily contaminated, and Sr was the dominant COC. The positive matrix factorization model suggested four sources for the COCs in soil, including Sr slag pile/SrCO3 production, agricultural activities, industrial activities, and natural sources, with contribution rates of 66.88%, 5.28%, 7.5%, and 20.34%, respectively. Monte Carlo simulation-based probabilistic health risk assessment revealed that the non-carcinogenic risk of groundwater, and the carcinogenic risk of soil and groundwater, were unacceptable. Notably, Sr was the unique COC posing non-carcinogenic risk among the COCs studied. Our results provide the scientific support needed for managing Sr point source impacted area.


Assuntos
Metais Pesados , Poluentes do Solo , China , Monitoramento Ambiental , Metais Pesados/análise , Medição de Risco , Solo , Poluentes do Solo/análise , Estrôncio , Água
11.
Int J Mol Sci ; 22(23)2021 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-34884557

RESUMO

Octacalcium phosphate (OCP, Ca8H2(PO4)6·5H2O) is known to be a possible precursor of biological hydroxyapatite formation of organic bone tissue. OCP has higher biocompatibility and osseointegration rate compared to other calcium phosphates. In this work, the synthesis of low-temperature calcium phosphate compounds and substituted forms of those at physiological temperatures is shown. Strontium is used to improve bioactive properties of the material. Strontium was inserted into the OCP structure by ionic substitution in solutions. The processes of phase formation of low-temperature OCP with theoretical substitution of strontium for calcium up to 50 at.% in conditions close to physiological, i.e., temperature 35-37 °C and normal pressure, were described. The effect of strontium substitution range on changes in the crystal lattice of materials, the microstructural features, surface morphology and biological properties in vitro has been established. The results of the study indicate the effectiveness of using strontium in OCP for improving biocompatibility of OCP based composite materials intended for bone repair.


Assuntos
Materiais Biocompatíveis/farmacologia , Regeneração Óssea , Osso e Ossos/citologia , Fosfatos de Cálcio/síntese química , Fosfatos de Cálcio/farmacologia , Mesoderma/citologia , Animais , Materiais Biocompatíveis/síntese química , Osso e Ossos/efeitos dos fármacos , Durapatita/química , Técnicas In Vitro , Mesoderma/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C3H , Espécies Reativas de Oxigênio/metabolismo , Estrôncio/química , Engenharia Tecidual
12.
Sci Rep ; 10(1): 15416, 2020 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-32963276

RESUMO

Hydraulic fracturing is often criticized due in part to the potential degradation of ground and surface water quality by high-salinity produced water generated during well stimulation and production. This preliminary study evaluated the response of the freshwater mussel, Elliptio complanata, after exposure to produced water. A limited number of adult mussels were grown over an 8-week period in tanks dosed with produced water collected from a hydraulically fractured well. The fatty tissue and carbonate shells were assessed for accumulation of both inorganic and organic pollutants. Ba, Sr, and cyclic hydrocarbons indicated the potential to accumulate in the soft tissue of freshwater mussels following exposure to diluted oil and gas produced water. Exposed mussels showed accumulation of Ba in the soft tissue several hundred times above background water concentrations and increased concentrations of Sr. Cyclic hydrocarbons were detected in dosed mussels and principle component analysis of gas chromatograph time-of-flight mass spectrometer results could be a novel tool to help identify areas where aquatic organisms are impacted by oil and gas produced water, but larger studies with greater replication are necessary to confirm these results.


Assuntos
Bário/efeitos adversos , Bivalves/efeitos dos fármacos , Água Doce/química , Hidrocarbonetos Cíclicos/efeitos adversos , Estrôncio/efeitos adversos , Água/química , Animais , Fraturamento Hidráulico/métodos , Alimentos Marinhos , Poluentes Químicos da Água/efeitos adversos
13.
Environ Geochem Health ; 42(11): 3675-3701, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32488799

RESUMO

Groundwater is one of the most important sources of water for drinking and cooking in rural India. A total of 382 groundwater samples were collected from 58 villages and analyzed for HMs and Sr by inductively coupled plasma mass spectrometer. The average concentrations of HMs and Sr in water was in the order of strontium (Sr) > arsenic (As) > chromium (Cr) > lead (Pb) > mercury (Hg) > cadmium (Cd). Out of 58 villages, 21, 37, 35, 35, 35 and 39 villages had Cr, As, Cd, Hg, Pb and Sr higher (WHO limit) than their respectively permissible levels. Health risk assessment of HMs and Sr for humans revealed that the non-carcinogenicity hazard quotients (HQi+d) for HMs and Sr were higher than unity for adult and children. The hazard index (HI) was 531.066 for adult and 902.926 for children. The HI > 1 was observed in 45 villages for adults and 56 villages for children. The lifetime cancer risk in adult for Asi, Asd, and Pbi in 36, 25 and 23 villages, whereas in children was 42, 20 and 22 villages, respectively. In conclusion, the health risks arising from consumption of groundwater containing HMs and Sr indicated that there is a significant carcinogenic risks for adult and children. This is the first attempt to provide information on the health risks of Sr in drinking water in India. The present findings can be useful for the development of potential strategies for risk control and management.


Assuntos
Exposição Dietética/efeitos adversos , Metais Pesados/análise , Estrôncio/análise , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade , Adulto , Carcinógenos/análise , Carcinógenos/toxicidade , Criança , Culinária , Exposição Dietética/análise , Água Potável/análise , Água Subterrânea/química , Humanos , Índia , Metais Pesados/toxicidade , Nível de Efeito Adverso não Observado , Medição de Risco , Estrôncio/toxicidade
14.
Artigo em Inglês | MEDLINE | ID: mdl-31881162

RESUMO

Identifying and monitoring dietary toxicants is an important component of contemporary food safety systems. To characterise their potential dietary risks, analysis was undertaken of 10 elements: antimony, barium, beryllium, boron, bromine, lithium, nickel, strontium, thallium and uranium in 132 different food types. All 10 elements were reported as quantified in aportion of the analysed foods, with prevalence ranging from less than 1% for antimony to 98% for barium. Dietary exposure assessment was undertaken for 10 New Zealand population cohorts using apublished simulated diet, and proportionality of food groups to total exposure identified. Characterisation against health-based guidance values identified no dietary risk from exposures to beryllium, boron, bromine, lithium, strontium and uranium to any of the population cohorts. For antimony and thallium, the exposure range for infants was calculated to exceed the health-based guidance value, and for barium and nickel, all mean exposures were above the health-based guidance value for younger population cohorts. Although some conservatism in applying upper-bound mean exposures reduces the likelihood of asignificant dietary risk, further laboratory method development and analysis of these elements in the New Zealand diet would be beneficial to ensure protection of New Zealand public health.


Assuntos
Exposição Dietética , Contaminação de Alimentos/análise , Oligoelementos/análise , Antimônio , Bário/análise , Berílio , Boro , Bromo , Humanos , Lítio , Nova Zelândia , Níquel , Medição de Risco , Estrôncio , Tálio , Urânio
15.
Food Chem ; 294: 35-45, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31126474

RESUMO

The 87Sr/86Sr ratio and Sr concentrations of 43 authentic Bordeaux wines from the world's most prestigious châteaux are presented in the context of their relation to the geographical origin of wine and authenticity. The results demonstrate relatively narrow spans of variabilities observed for 87Sr/86Sr ratio and Sr concentrations in authentic Bordeaux wines, which can be used with reasonable certainty as specific parameters for identifying regional wineries. For comparison, a set of imitated Bordeaux wines was studied for Sr isotopic and elemental compositions. A significant excess of both parameters in suspicious wines were found in reference to authentic values. Such natural and anthropogenically induced variations offer an enhanced discriminating potential of Sr. The unique Sr binary signature may detect imitated wines and trace genuine products from different regional wineries. The obtained results shown a promising perspective for wine authenticity control by means of Sr isotopic and elemental composition.


Assuntos
Estrôncio/análise , Vinho/análise , Fazendas , Espectrometria de Massas , Solo/química , Isótopos de Estrôncio/análise
16.
Sci Total Environ ; 670: 433-438, 2019 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-30904655

RESUMO

The present research was to study the toxicology of artificially added Zn, Se and Sr in water. Specifically, we investigated the mortality and liver toxicity in zebrafish (Danio rerio), caused by different water concentrations of zinc sulfate (ZnSO4), sodium selenite (Na2SeO3), and strontium chloride hexahydrate (6H2O·SrCl2). Adult and embryo-larval zebrafish were used in the experiment. Analysis was performed of mortality, liver area and impermeability, delayed absorption area of the yolk sac, and liver tissue structure. The concentration change of sodium selenite exerted the most significant effect on the mortality of adult zebrafish, followed by that of strontium chloride hexahydrate, and zinc sulfate. Elevated strontium chloride hexahydrate concentration was associated with liver toxicity in zebrafish in the preliminary experiment. However, embryo-larval zebrafish were observed to die when the concentration of Zn2+ or Se4+ increased to a certain extent, without obvious liver toxicity. Our results indicated strontium chloride hexahydrate was hepatotoxic to embryo-larval zebrafish, which was manifested mainly as hepatomegaly and delayed absorption of the yolk sac. In addition, the artificially added strontium chloride hexahydrate destroyed liver tissue structure, resulting in hepatocyte enlargement, cell nucleus enlargement, blurred cytoplasmic boundaries, and formation of a vacuolar liver. These findings suggest the amount of strontium chloride hexahydrate added in soft drinks should be limited to certain levels.


Assuntos
Selênio/toxicidade , Estrôncio/toxicidade , Poluentes Químicos da Água/toxicidade , Zinco/toxicidade , Animais , Testes de Toxicidade , Peixe-Zebra
17.
Ecotoxicol Environ Saf ; 164: 181-188, 2018 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-30114568

RESUMO

Information about the concentrations of strontium (Sr(II)) in drinking water in China and the corresponding health risks to Chinese residents is lacking. This study investigated Sr(II) in drinking water through a monthly sampling campaign in twelve locations in Xi'an, Northwest China. A health risk assessment for different age groups and exposure pathways were carried out by Monte Carlo simulation. The results show Sr(II) concentrations of 0.06-1.69 mg/L in all drinking water samples, which exceeded the minimum reporting level (MRL) of 0.3 µg/L. Also, one sample exceeded the health reference level (HRL) of 1500 µg/L. Higher Sr(II) levels were recorded in groundwater supply zones and springs, and more potential changes in Sr(II) occurred in distribution pipes transporting groundwater. The non-carcinogenic risk associated with Sr(II) exposure via drinking water was less than 1, indicating no significant health risk to the residents of Xi'an. As the first attempt to provide information on the health risks of Sr(II) in drinking water in China, findings from this study can be useful for the development of potential strategies for risk control and management.


Assuntos
Água Potável/química , Estrôncio/análise , Poluentes Químicos da Água/análise , China , Monitoramento Ambiental , Água Subterrânea/química , Humanos , Método de Monte Carlo , Medição de Risco , Sensibilidade e Especificidade
18.
Radiat Prot Dosimetry ; 181(2): 135-141, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-29378063

RESUMO

Phase dependent optically stimulated luminescence (OSL) is studied in Cu-doped Sr4Si3O8Cl4. The Study shows that samples in which amount of contributing strontium metasilicate phase in Cu-doped Sr4Si3O8Cl4 is less, show intense OSL while those samples in which strontium metasilicate phase is more show weak OSL. The observed Cu luminescence is also found to be phase dependent. Sample in which Sr4Si3O8Cl4 phase is dominant, the observed Cu luminescence is around 350 nm whereas an additional longer wavelength band around 450 nm is observed when the strontium metasilicate phase is present in significant amount. The relatively phase pure, Cu-doped Sr4Si3O8Cl4 shows good OSL properties. The sensitivity of such material is 3.89 times more compared to commercial Al2O3:C (Landauer Inc.). High sensitivity, good linearity and reusability, along with low fading make this material as good OSL phosphor and may find applications in OSL based radiation dosimetry.


Assuntos
Cobre/química , Luminescência , Substâncias Luminescentes/química , Dosimetria por Luminescência Estimulada Opticamente/métodos , Compostos de Silício/química , Estrôncio/química , Teste de Materiais , Método de Monte Carlo , Óptica e Fotônica , Doses de Radiação
19.
Med Phys ; 45(1): 81-91, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29080282

RESUMO

PURPOSE: Dual-energy X-ray absorptiometry (DXA) is the gold standard technique to measure areal bone mineral density (aBMD) for the diagnosis of osteoporosis. Because DXA relies on the attenuation of photon to estimate aBMD, deposition of bone-seeking metallic elements such as strontium, lead, and aluminum that differ in atomic numbers from calcium can cause inaccurate estimation of aBMD. Quantitative ultrasound (QUS) is another technique available to assess bone health by measuring broadband ultrasound attenuation (BUA), speed of sound (SOS), and an empirically derived quantity called stiffness index (SI). Because the acoustic properties are not prone to significant change due to changes in microscopic atomic composition of bone, it is hypothesized that QUS is unaffected by the presence of bone-seeking elements in the bone. The objective of this study was to investigate the effect of strontium, lead, and aluminum on DXA-derived aBMD and QUS parameters using bone-mimicking phantoms compatible with both techniques. METHODS: Bone-mimicking phantoms were produced by homogeneously mixing finely powdered hydroxyapatite compounds that contain varying concentrations of strontium, lead, or aluminum with porcine gelatin solution. Seven strontium-substituted phantoms were produced with varying molar ratio of Sr/(Sr + Ca) ranging from 0% to 2%. Four lead-doped phantoms and four aluminum-doped phantoms were constructed with the respective analyte concentrations ranging from 50 to 200 ppm. An additional 0 ppm phantom was produced to be used as a baseline for the lead and aluminum phantom measurements. All phantoms had uniform volumetric bone mineral density (vBMD) of 200 mg/cm3 , and were assessed using a Hologic Horizon® DXA device and a Hologic Sahara® QUS device. Furthermore, theoretical aBMD bias for mol/mol% substitution of calcium with the three bone-seeking elements was calculated. RESULTS: Strong positive linear relationship was found between aBMD measured by DXA and strontium concentration (P < 0.001, r = 0.995). From the measurement of lead and aluminum phantoms using DXA, no statistically significant relationship was observed between aBMD and the analyte concentrations. For the QUS system, with an exception of BUA and lead concentration that exhibited statistically significant relationship (P < 0.038, r = 0.899), no statistically significant change was observed in all QUS parameters with respect to the clinically relevant concentration of all three elements. The calculated theoretical aBMD bias induced by 1 mol/mol% substitution of calcium with strontium, lead, and aluminum were 10.8%, 4.6%, and -0.7%, respectively. CONCLUSION: aBMD measured by DXA was prone to overestimation in the presence of strontium, but acoustic parameters measured by QUS are independent of strontium concentration. The deviation in aBMD induced by the clinically relevant concentrations of lead and aluminum under 200 ppm could not be detected using the Hologic Horizon® DXA device. Furthermore, the SI measured by the QUS system was not affected by lead or aluminum concentrations used in this study.


Assuntos
Absorciometria de Fóton/instrumentação , Alumínio , Osso e Ossos/diagnóstico por imagem , Chumbo , Imagens de Fantasmas , Estrôncio , Ultrassonografia/instrumentação , Densidade Óssea , Osso e Ossos/fisiologia
20.
Femina ; 45(2): 82-89, jun. 2017. ilus
Artigo em Português | LILACS | ID: biblio-1415432

RESUMO

Osteoporose é um problema de saúde pública importante que acomete mais de metade das mulheres com idade superior a 50 anos. Doença com um enorme impacto sobre a saúde pública, através da morbidade e mortalidade aumentadas, com custos econômicos associados resultantes das fraturas. O objetivo é avaliar e identificar as pessoas de risco para desenvolver fraturas osteoporóticas de fragilidade que necessitam ser tratadas. A abordagem de mulheres com baixa massa óssea e aumento do risco de fraturas deve ser multidisciplinar. A farmacoterapia é apenas uma Steiner ML, Strufaldi R, Fernandes CE das possíveis intervenções. Aspectos como a nutrição orientada, fortalecimento muscular, prevenção de quedas, suplementos vitamínicos e minerais devem ser considerados. O tratamento farmacológico permite a prevenção da perda óssea, a prevenção primária e secundária de fragilidade óssea e deve ser baseado na avaliação do risco de fratura do indivíduo e na relação custo-benefício do medicamento escolhido.


Osteoporosis is a significant public health problem that affects more than half of women aged over 50. This disease has a huge impact on public health through morbidity and increased mortality, and economic costs associated with the resulting fractures. The goal is to assess and identify risk people to develop osteoporotic fragility fractures that need to be addressed. The approach of women with low bone mass and increased risk of fractures should be multidisciplinary. Pharmacotherapy is just one of the possible interventions. Aspects such as the guidance nutrition, muscle strengthening, prevention of falls, mineral and vitamin supplements should be considered. Pharmacological treatment allows preventing bone loss and primary and secondary prevention of osteoporosis and should be based on risk factors and pharmaceutical cost benefit analysis.


Assuntos
Humanos , Feminino , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Osteoporose/tratamento farmacológico , Osteoporose Pós-Menopausa/tratamento farmacológico , Fraturas por Osteoporose/prevenção & controle , Hormônio Paratireóideo/uso terapêutico , Estrôncio/uso terapêutico , Grupos de Risco , Calcitonina/uso terapêutico , Terapia de Reposição de Estrogênios , Fatores de Risco , Moduladores Seletivos de Receptor Estrogênico , Difosfonatos/uso terapêutico , Denosumab/uso terapêutico
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