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1.
China Tropical Medicine ; (12): 625-2023.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-979777

RESUMO

@#Abstract: Objective This study aims to explore the prevalence and risk factors of metabolic syndrome (MS) among the adults in Hainan Province, and to provide scientific basis for MS prevention and control. Methods A multi-stage cluster random sampling method was applied to select 3 690 permanent residents aged 18 years and above in Hainan Province. The survey was conducted by trained investigators using household appointments and centralized surveys. A questionnaire survey, physical measurement, and laboratory examination were conducted after the collection of blood samples. The processed samples were then tested by a quality-controlled laboratory. Finally, we analysed the prevalence of metabolic syndrome (MS) and its relationship with population characteristics and health-related behaviors. Results The crude prevalence of MS in the population aged 18 and above in Hainan province was 19.46% and the standardized prevalence was 13.21%, with a higher rate in urban areas (22.21%) than in rural areas (18.13%). The prevalence of MS increased with age (P<0.001), and there were significant differences in MS prevalence among different marital and occupational statuses (P<0.01). Logistic regression results indicated that the age groups of 40-<50 years (OR=2.986, 95%CI:1.355-6.580), 50-<60 years (OR=3.739, 95%CI: 1.715-8.151), 60-<70 years (OR=3.890, 95%CI: 1.769-8.556), 70 years and above (OR=3.927, 95%CI: 1.758-8.771), technical, transportation and production personnel (OR=1.579, 95%CI: 1.033-2.412), retired (OR=1.788, 95%CI: 1.415-2.259), unemployed (OR=1.503, 95%CI: 1.044-2.165), smoking cessation (OR=1.582, 95%CI: 1.162-2.154), insufficient intake of fruits and vegetables (OR=1.196, 95%CI: 1.005-1.422), and insufficient physical activity (OR=1.437, 95%CI: 1.155-1.787) were all associated with the prevalence of MS. Among the investigated subjects, 30.22% of them had one abnormal component, with hyperglycemia being the highest (54.44%); 24.25% of them had two abnormal components, with "hyperglycemia + hypertension" being the highest (33.30%); and 19.46% had three or more components, with "overweight/obesity + hyperglycemia + hypertension" being the highest (24.79%). Conclusions The prevalence of MS in Hainan Province is on the rise, and effective lifestyle intervention measures are needed to reduce the risk of MS.

2.
China Tropical Medicine ; (12): 205-2023.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-979617

RESUMO

@#Objective To understand the overall under-reporting of cause of death monitoring in Hainan Province, and to provide a scientific basis for evaluating the data from death registration report and health planning in Hainan. Methods Multi-stage cluster random sampling was used, all towns/streets in cities and counties of the province were ranked from highest to lowest in terms of crude death rate, divided into high, medium and low levels (the number of each level was basically the same), and one was randomly selected from each level. A total of three towns/streets were used as survey areas, and all households in the area were survey households. Death information of resident population during 2018-2020 was collected and compared with routine surveillance data for the same period. The under-reporting rate was calculated, and comparison between groups was performed by chi-square. Results A total of 12 583 death cases were investigated from 2018 to 2020, and the average mortality was 621.48/105. 4 809 cases were missed with the total under-reporting rate of 38.22%. The under-reporting rate from 2018 to 2020 were 39.75%, 39.99% and 34.77% (χ2=30.404, P<0.01) respectively. The under-reporting rate in eastern and central and western areas were 30.33%, 30.10% and 60.15% (χ2=931.901, P<0.01) respectively. The negative rate were different in different years old group (χ2=14.834, P<0.05). Of the 4 809 under-reported cases, as many as 93.49% died at home, and the composition of deaths in hospitals was about 10 times higher in the center than in the east and west, and the proportion of those who died in hospital in central areas was about 10 times higher than in eastern and central areas. Conclusions More than half of the cities and counties in Hainan Province have improved the completeness of cause of death surveillance data. The under-reporting rate in age group <5 years are still high, and regular under-reporting investigations are still needed to strengthen the reporting and management of death information.

3.
World J Clin Cases ; 10(36): 13426-13434, 2022 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-36683633

RESUMO

BACKGROUND: Gaucher disease (GD) is caused by a GBA1 gene mutation that leads to decreased acid ß-glucosidase activity [glucocerebrosidase (GCase)]. This study aimed to identify and characterise compound heterozygous mutations in GBA1 in a patient with type 1 GD. CASE SUMMARY: Here, we report a rare adult-onset type 1 GD in a 46-year-old female patient with clinical manifestations of giant spleen, thrombocytopenia, and bone pain, diagnosed by enzymatic and genetic testing. Enzymology and whole exome sequencing revealed heterozygous missense mutations in exon 10 c.1448T>C (p.L483P) and exon 7 c.928A>G (p.S310G) of GBA1. The latter was first reported in patients with GD. Structural modelling showed that p.S310G and p.L483P were distant from the GCase active site. The p.S310G mutation in domain 1 may decrease stability between the α2 and α3 helices of GBA1. The p.L483P mutation in domain 2 reduced the van der Waals force of the side chain and disrupted the C-terminal ß-sheet. The patient was treated with imiglucerase replacement therapy, and her condition was stable. CONCLUSION: The p.L483P/p.S310G novel compound heterozygous mutation underlies type 1 GD and likely affects GCase protein function. This is the first description of p.S310G being associated with mild type 1 GD in the context of a coinherited p.L483P mutation.

4.
China Tropical Medicine ; (12): 1061-2022.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-974021

RESUMO

@#Abstract: Objective To understand the general situation of death causes of permanent residents in Hainan Province from 2014 to 2020, analyze the causes of death, and provide scientific basis for the formulation of policies related to healthy Hainan. Methods The Hainan Provincial Population Death Information Registration and Management System was used to report data, and the death information of permanent residents in Hainan Province from 2014 to 2020 was obtained. Excel 2010 and SPSS 26.0 software were applied to perform statistical analysis related to the indicators including crude mortality rate, standardized mortality rate, ranking of causes of death, and composition ratio; the standardized mortality rate was calculated based on the data of the 2010 National Census Data. Results From 2014 to 2020, the average annual resident population of Hainan Province was 9 175 300, and average annual resident population at each of the eight monitoringp oints is 297 100, anaverage of 83 878 cumulative deaths were reported, the annual total mortality rate was 504.09/100 000, the standard mortality rate was 618.69/100 000. The standardized mortality rates of male and female were 806.18/100 000 and 444.36/100 000 respectively (P<0.01). The mortality rate of all age groups showed that the crude mortality rate of 0~<1 years old group showed a decreasing trend with the passage of time, and the crude mortality rate was significantly higher than that of other age groups. From the age of 20, with the increase of age, the overall crude mortality rate of residents keeps increasing. The crude death rate increases rapidly after the age of 65, and peaks especially after the age of 85. The leading causes of death were circulatory diseases, tumors and respiratory diseases. From 2014 to 2020, the mortality rate of circulatory diseases and tumors, the two main causes of death, was more than 100/100 000. Conclusion Chronic non-communicable diseases are still the first cause of death among permanent residents in Hainan Province. Targeted intervention and treatment of chronic non-communicable diseases is beneficial to reduce their mortality.

5.
ACS Appl Mater Interfaces ; 12(2): 2687-2694, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31860262

RESUMO

Silicon germanium (SiGe) alloys hold promise for thermoelectric power generation at high temperatures and have been applied in deep-space missions. However, enhancement of the dimensionless thermoelectric figure-of-merit (ZT) is still needed for practical civil applications of SiGe. In this work, we report high-performance oxide/SiGe bulk composites that were obtained via hot-press sintering of mixed powders composed of phosphorus (P)-doped SiGe prepared via mechanical alloying, using a ball-milling technique and La-Nb-doped SrTiO3 (La-Nb-STO). The La-Nb-STO powder was obtained from ball milling of a bulk La-Nb-STO sample that was sintered via hot pressing of hydrothermally synthesized La-Nb-STO powder. Controlling the amount of La-Nb-STO nanoparticles added to SiGe matrix increased the power factor by optimizing the electron concentration and mobility in the composite. In addition, compared with single-phase P-doped SiGe, the second phase decreased the thermal conductivity because of additional phonon scattering at the interface. As a result, a high ZT of 0.91 was realized in the n-type oxide/SiGe bulk composite at 1000 K, which was 18% larger than that for the typical materials used in space flight missions and 5% higher than the single-phase SiGe alloys obtained in the present study. The strategy used in this study could also be viable to further enhance the ZT of nanostructured n-type SiGe and SrTiO3-based oxide materials.

6.
J Hazard Mater ; 277: 141-9, 2014 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-24613401

RESUMO

Letrozole (LET) is a triazole-containing drug that can inhibit the activity of cytochrome P450 aromatase. It is an environmentally emerging pollutant because of its broad use in medicine and frequent occurrence in aquifers receiving the effluent of municipal or hospital wastewater. However, the toxic impact of LET on fish populations remains unclear. We exposed medaka fish (Oryzias latipes) at an early stage of sexual development to a continuous chronic LET at environmentally relevant concentrations and assessed the endocrine disruption effects in adulthood and the next generation. LET exposure at an early life stage persistently altered phenotypic sex development and reproduction in adults and skewed the sex ratio in progeny. As well, LET exposure led to a gender-different endocrine disruption as seen by the interruption in gene expression responsible for estrogen synthesis and metabolism and fish reproduction. LET interfering with the aromatase system in early life stages of medaka can disrupt hormone homeostasis and reproduction. This potent aromatase inhibitor has potential ecotoxicological impact on fish populations in aquatic environments.


Assuntos
Inibidores da Aromatase/toxicidade , Disruptores Endócrinos/toxicidade , Nitrilas/toxicidade , Oryzias/crescimento & desenvolvimento , Triazóis/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Embrião não Mamífero/efeitos dos fármacos , Larva , Letrozol , Oryzias/metabolismo , Maturidade Sexual/efeitos dos fármacos
7.
Water Res ; 53: 351-60, 2014 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-24531031

RESUMO

Ketamine has been increasingly used both recreationally and medicinally around the world. Although the metabolic pathways to form its metabolite norketamine have been carefully investigated in humans and animals, knowledge of their environmental occurrence and fate is limited. In this study, we investigated the occurrence of ketamine and norketamine in 20 natural bodies of water, effluents from 13 hospitals, two wastewater treatment plants and one water supply plant. Ketamine was found at concentrations as high as 10 µg/L. Ketamine and norketamine were consistently found in similar concentrations (ketamine/norketamine ratio: 0.3-4.6) in the collected water samples, and this ratio similar to that found in urine samples. Dark incubation experiments have shown that ketamine is not susceptible to microbial degradation or hydrolysis. Phototransformation was demonstrated to significantly reduce the concentration of ketamine and norketamine in river waters (t(1/2) = 12.6 ± 0.4 and 10.1 ± 0.4 h, respectively) and resulted in byproducts that are similar to human metabolites. Both direct and indirect photolysis led to the N-demethylation of ketamine to form norketamine and other byproducts, including hydroxy-norketamine (HNK), dehydronorketamine (DNK), hydroxy-ketamine (HK) and isomer forms of ketamine and norketamine. Irradiated solutions exhibited higher toxicity (via the Microtox test). Although a final risk assessment could not be made due to a lack of studies on the chronic effects on aquatic organisms, the high and persistent environmental occurrences of ketamine and norketamine as well as the increasingly acute toxicity of the photo byproducts demonstrate the importance of including metabolites in evaluation of the overall risk of ketamine.


Assuntos
Aliivibrio fischeri/efeitos dos fármacos , Monitoramento Ambiental , Ketamina/análogos & derivados , Ketamina/toxicidade , Fotólise , Águas Residuárias , Poluentes Químicos da Água/toxicidade , Cromatografia Líquida , Água Doce/química , Hospitais , Ketamina/análise , Ketamina/química , Dose Letal Mediana , Taiwan , Espectrometria de Massas em Tandem , Águas Residuárias/química , Águas Residuárias/toxicidade , Poluentes Químicos da Água/química
8.
Int J Mol Sci ; 15(2): 1946-61, 2014 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-24473143

RESUMO

The insect midgut epithelium is generally lined with a unique chitin and protein structure, the peritrophic membrane (PM), which facilitates food digestion and protects the gut epithelium. PM proteins are important determinants for PM structure and formation. In this study, the silkworm Bombyx mori midgut PM protein BmCDA7 was identified by proteomic tools. The full-length BmCDA7 cDNA is 1357 bp; the deduced protein is composed of 379 amino acid residues and includes a 16 amino acid residue signal peptide, a putative polysaccharide deacetylase-like domain and 15 cysteine residues present in three clusters. The heterologously expressed proteins of the BmCDA7 gene in yeast displayed chitin deacetylase activity. Expression of B. mori BmCDA7 was detected in the midgut at both the transcriptional and translational levels. The BmCDA7 gene was expressed by the newly hatched silkworm larvae until day seven of the fifth instar and was expressed at a high level in the newly exuviated larvae of different instars. The functions and regulatory mechanism of BmCDA7, however, need further investigation.


Assuntos
Amidoidrolases/genética , Amidoidrolases/metabolismo , Bombyx/enzimologia , Bombyx/genética , Proteínas de Insetos , Amidoidrolases/química , Sequência de Aminoácidos , Animais , Sequência de Bases , Ativação Enzimática , Expressão Gênica , Dados de Sequência Molecular , Especificidade de Órgãos/genética , Transporte Proteico , Proteômica , Proteínas Recombinantes
9.
Environ Pollut ; 186: 203-15, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24388870

RESUMO

Sunlight photodegradation has long been considered a significant process in lowering the concentrations of pharmaceuticals in surface waters and thus decreasing the ecological risk. For the first time, this study identified the significance of investigating the environmental photodegradation of a pharmaceutical residue mixture (rather than a single compound) and the associated toxicity of transformation byproducts in environmental waters, including rivers, hospital wastewaters, and effluents from wastewater treatment plants and pharmaceutical production facilities. Pharmaceuticals undergo phototransformation rather than mineralization (11-23% in 34 h). Pharmaceutical mixtures could possibly act as dissolved organic matter for each individual compound and subsequently affect the photolysis rates. The increased toxicity of irradiated pharmaceutical mixtures challenges the validity of the current understanding of sunlight photolysis. The implications of this work suggest that current knowledge concerning the occurrence, natural attenuation, ecotoxicity, and human health risks of pharmaceuticals is far from complete; photolysis is not necessarily a purification process.


Assuntos
Preparações Farmacêuticas/química , Fotólise , Rios/química , Poluentes Químicos da Água/química , Ecologia , Humanos , Preparações Farmacêuticas/análise , Medição de Risco , Luz Solar , Poluentes Químicos da Água/análise , Purificação da Água/métodos
10.
Environ Sci Technol ; 47(9): 4104-12, 2013 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-23600792

RESUMO

The use of cytotoxic substances, such as 5-fluorouracil and cyclophosphamide, is carefully controlled; however, these medications may still enter bodies of water through wastewater discharge. These substances may pose risks to stream and river life, as well as to humans via drinking water. In this study, the photochemical fate of 5-fluorouracil and cyclophosphamide was investigated in synthetic waters and four river waters and was found to be the most important attenuation process for each entity in natural surface waters. Bicarbonate alone was found to react with the excited states of 5-fluorouracil, thus enhancing direct photolysis rates. In the presence of nitrate and significant amounts of bicarbonate (close to 2 mM), 5-fluorouracil was rapidly removed (within 1 day) through indirect photolysis. In contrast, natural attenuation was of low importance for cyclophosphamide in most surface waters studied. A long, shallow river or lake with a long residence time (>7 days), very low alkalinity, and significant nitrate levels (>5 mg-N L(-1)) may be an exception. The phototransformation product of 5-fluorouracil was also identified. However, the total organic carbon experiments yielded important results: photolysis resulted in quick transformation of 5-fluorouracil but minimal mineralization. Additional studies of the toxicity of photobyproducts of 5-fluorouracil are needed to determine the true risk to human health of 5-fluorouracil contamination of surface water, given its near-total photodegradation and resultant, deceptively low detection rate in surface waters.


Assuntos
Antineoplásicos/química , Ciclofosfamida/química , Fluoruracila/química , Fotólise , Poluentes Químicos da Água/química , Carbono/análise , Cromatografia Líquida/métodos , Espectrometria de Massas em Tandem/métodos
11.
Water Res ; 47(3): 1308-16, 2013 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-23286987

RESUMO

The direct incorporation of chloramines and dissolved organic nitrogen (DON) may provide the nitrogen for nitrogenous disinfection byproducts (N-DBPs). This study explores the contributions of natural DON and chloramine incorporation to the formation of N-DBPs during chloramination. This study also evaluates the relationship between N-DBPs and carbonaceous DBPs by investigating four sources of dissolved organic matter with different DON-to-dissolved organic carbon (DOC) ratios. During chloramination, dihaloacetonitrile (DXAN) formation is correlated with the summation of trihalomethanes (THMs) and dichloroacetic acids (DXAAs) yield in molar basis at pH > 6. This study tests the formation kinetics of THMs, DXAAs, and DXANs during chloramination, explores the changes in DBP formation potential before and after a sequence of ozonation and chloramination, and tracks the nitrogen source of dichloroacetonitrile. The results support the hypothesis that THMs, DXAAs, and DXANs mainly derive from similar precursors upon chloramination. In addition, the precursor of HANs was approximately 10% (on a molar basis) of that of THMs and HAAs combined. The N-nitrosodimethylamine (NDMA) formation potential is correlated with DON/DOC in hydrophilic and transphilic fractions. Isotope (15)N-labeled monochloramine coupled with LC-electrospray ionization-tandem mass spectrometry was used to explore the nitrogen source of NDMA formed in chloraminated organic fractions. The results indicate that the nitroso group of the formed NDMA originates mainly from chloramines.


Assuntos
Cloraminas/química , Nitrogênio/química , Compostos Orgânicos/química , Ácido Dicloroacético/química , Concentração de Íons de Hidrogênio , Purificação da Água
12.
Environ Sci Technol ; 46(22): 12417-26, 2012 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-23062112

RESUMO

Photodegradation may be the most important elimination process for cephalosporin antibiotics in surface water. Cefazolin (CFZ) and cephapirin (CFP) underwent mainly direct photolysis (t(1/2) = 0.7, 3.9 h), while cephalexin (CFX) and cephradine (CFD) were mainly transformed by indirect photolysis, which during the process a bicarbonate-enhanced nitrate system contributed most to the loss rate of CFX, CFD, and cefotaxime (CTX) (t(1/2) = 4.5, 5.3, and 1.3 h, respectively). Laboratory data suggested that bicarbonate enhanced the phototransformation of CFD and CFX in natural water environments. When used together, NO(3)(-), HCO(3)(-), and DOM closely simulated the photolysis behavior in the Jingmei River and were the strongest determinants in the fate of cephalosporins. TOC and byproducts were investigated and identified. Direct photolysis led to decarboxylation of CFD, CFX, and CFP. Transformation only (no mineralization) of all cephalosporins was observed through direct photolysis; byproducts were found to be even less photolabile and more toxic (via the Microtox test). CFZ exhibited the strongest acute toxicity after just a few hours, which may be largely attributed to its 5-methyl-1,3,4-thiadiazole-2-thiol moiety. Many pharmaceuticals were previously known to undergo direct sunlight photolysis and transformation in surface waters; however, the synergistic increase in toxicity caused by this cocktail (via pharmaceutical photobyproducts) cannot be ignored and warrants future research attention.


Assuntos
Aliivibrio fischeri/efeitos dos fármacos , Antibacterianos/química , Antibacterianos/toxicidade , Cefalosporinas/química , Cefalosporinas/toxicidade , Água Doce/química , Fotólise , Carbonatos/química , Cromatografia Líquida , Luminescência , Nitratos/química , Compostos Orgânicos/química , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em Tandem
13.
Guang Pu Xue Yu Guang Pu Fen Xi ; 32(7): 1935-8, 2012 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-23016357

RESUMO

CT is widespread non-destructive detection technique for wood materials, and the density measurement is a key role during this application. In the present report, the use of CT for air-dry density measurement of wood and bamboo is described. The authors found that there were marked linear correlations between air-dry density (0.303-1.061 g x cm(-3)) of 24 kinds of woods and their respective CT value, as well as 25 kinds of lignin materials (including 24 kinds of woods and 1 kind of bamboo) and the CT value, both with correlation coefficient of 0.99, which belonged to the CT technological breakthrough for wood quantitative detection These research results show that CT is an appropriate way to measure density for wood and bamboo, and would provide technical support for CT used in the field of wood science research and wood processing.


Assuntos
Bambusa , Tomografia Computadorizada por Raios X , Madeira , Lignina
14.
Water Sci Technol ; 62(10): 2450-8, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-21076233

RESUMO

Pharmaceuticals and personal care products (PPCPs) constitute a class of chemicals of emerging concern due to the potential risks they pose to organisms and the environment, even at low concentrations (ng/L). Recent studies have found that PPCPs are not efficiently removed in secondary wastewater treatment plants (WWTPs). This study has: (1) simultaneously investigated the occurrence of sixty-one PPCPs using solid phase extraction and high-performance liquid chromatography-tandem mass spectrometry, (2) evaluated removal efficiencies of target PPCPs in six WWTPs that discharge effluents into major Taiwanese rivers, and lastly (3) examined matrix interference during analysis of target PPCPs in water samples. The twenty target PPCPs were chosen for their high detection frequencies, high influent concentrations, and stability during wastewater treatment processes. Caffeine and acetaminophen were detected at the highest concentrations (as high as 24,467 and 33,400 ng/L) and were effectively removed (both >96%); other PPCPs were detected in the high ng/L range but were not effectively removed. Matrix interference (by ion suppression or enhancement) during the analysis resulted in underestimation of the removal efficiencies of erythromycin-H(2)O, cefazolin, clarithromycin, ibuprofen, diclofenac, clofibric acid and gemfibrozil.


Assuntos
Cosméticos/química , Preparações Farmacêuticas/química , Eliminação de Resíduos Líquidos/métodos , Purificação da Água/métodos , Água/química , Taiwan
15.
Chemosphere ; 81(5): 562-70, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20851454

RESUMO

We have investigated the occurrence of controlled drugs in two rivers, two wastewater treatment plants (WWTPs) and five hospital effluents in Taipei, Taiwan, and report here the concentrations of controlled drugs used as prescription medication or drugs of abuse. Of the target drugs, morphine, codeine, methamphetamines and ketamine were observed in significant quantities in hospital effluents, with maximum concentrations of 1240, 378, 260 and 206 ng L(-1), respectively. The other six compounds (including metabolites) were found at trace levels or below the method detection limits. In addition, the high occurrence in river waters of methamphetamine, codeine and ketamine (maximum values 405, 57, and 341 ng L(-1), respectively) indicated the significant prevalence of these controlled drugs. This study demonstrated that effluents from hospitals and clinics and treated WWTP effluents contribute to the controlled substances that eventually reach natural rivers. We hypothesize that the occurrence of controlled drugs in the environment can be attributed to two main sources: (1) substance abuse by individuals and (2) treatment with prescription medication for acute and chronic pain. The presence of these contaminants in the aquatic environment may pose significant risk to aquatic and human life. Further studies are needed for verification and may contribute to the development of sustainable strategies for environmental remediation.


Assuntos
Monitoramento Ambiental , Água Doce/química , Medicamentos sob Prescrição/análise , Poluentes Químicos da Água/análise , Codeína/análise , Uso de Medicamentos/estatística & dados numéricos , Meio Ambiente , Hospitais , Ketamina/análise , Metanfetamina/análise , Morfina/análise , Eliminação de Resíduos Líquidos , Poluição Química da Água/estatística & dados numéricos
16.
Guang Pu Xue Yu Guang Pu Fen Xi ; 30(3): 829-33, 2010 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-20496720

RESUMO

A rapid multi-element analysis method for clay mineral samples was described. This method utilized a polarized wave-length dispersive X-ray fluorescence spectrometer--Axios PW4400, which had a maximum tube power of 4 000 watts. The method was developed for the determination of As, Mn, Co, Cu, Cr, Dy, Ga, Mo, P, Pb, Rb, S, Sr, Ni, ,Cs, Ta, Th, Ti, U, V, Y, Zn, Zr, MgO, K2O, Na2O, CaO, Fe2O3, Al2O3, SiO2 and so on. Thirty elements in clay mineral species were measured by X-ray fluorescence spectrometry with pressed powder pellets. Spectral interferences, in particular the indirect interferences of each element, were studied. A method to distinguish the interference between each other periodic elements in element periodic table was put forward. The measuring conditions and existence were mainly investigated, and the selected background position as well as corrected spectral overlap for the trace elements were also discussed. It was found that the indirect spectral overlap line was the same important as direct spectral overlap line. Due to inducing the effect of indirect spectral overlap, some elements jlike Bi, Sn, W which do not need analysis were also added to the elements channel. The relative standard deviation (RSD) was in the range of 0.01% to 5.45% except three elements Mo, Cs and Ta. The detection limits, precisions and accuracies for most elements using this method can meet the requirements of sample analysis in clay mineral species.

17.
Guang Pu Xue Yu Guang Pu Fen Xi ; 29(8): 2268-71, 2009 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-19839355

RESUMO

In the present paper a method for the determination of strontium, barium, calcium, magnesium, silicon, iron, aluminum and sulfur in the product of strontium carbonate by X-ray fluorescence spectrometry with pressed powder sample preparation was developed, and the standard samples were synthesized by high purity reagent. As the contents of strontium in the product of strontium carbonate were very high, the phenomenon of spectrum-peak-saturated occurred and the count rate was overflowed according to the measuring condition which was automatically given by the software system of X-ray fluorescence spectrometry. As a result, the deviation of the measurement is greater. According to analyzing the measuring condition of strontium, a method was given for reducing the count rate by reducing the measuring power of strontium, thus achieving the goal of measurement. When sulfate was measured with pressed powder sample, the results were enhanced with the increase in measuring number. In light of this situation, a method was proposed to solve the problem. As the self-forming characteristic of the product of strontium carbonate was not so well, it was very difficult to press the sample successfully. So, the condition of squash method involving the kinds of the adhesives, the mixing technique with powder sample and the pressing-time technique was discussed. During making the sample, it was found that the effects of pellet formation were better if the time could be delayed by 120 seconds. Matrix effect was corrected by alpha coefficient method, the accuracy of the method was evaluated by analysis of synthetic sample. Detection limits of 0.623-107.6 mg x g(-1) were obtained. The results were in good agreement with certified values with precision of < 2.5% RSD.

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