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1.
AIMS Neurosci ; 10(2): 87-108, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37426775

RESUMO

Procedures for neurological disorders such as Parkinsons Disease (PD), Essential Tremor (ET), Obsessive Compulsive Disorder (OCD), Tourette's Syndrome (TS), and Major Depressive Disorder (MDD) tend to overlap. Common therapeutic procedures include deep brain stimulation (DBS), lesioning, and focused ultrasound (FUS). There has been significant change and innovation regarding targeting mechanisms and new advancements in this field allowing for better clinical outcomes in patients with severe cases of these conditions. In this review, we discuss advancements and recent discoveries regarding these three procedures and how they have led to changes in utilization in certain conditions. We further discuss the advantages and drawbacks of these treatments in certain conditions and the emerging advancements in brain-computer interface (BCI) and its utility as a therapeutic for neurological disorders.

2.
Environ Geochem Health ; 45(11): 7665-7677, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37415002

RESUMO

Overuse of aluminum salts (a.k.a., alum) in coagulation and flocculation processes in water treatment raises concerns about increased levels of aluminum (Al) in drinking water. In this study, we present a probabilistic human health risk assessment (HRA) for non-cancerogenic risks, with Sobol sensitivity analysis, to vet the concern of increased health risk from Al in drinking water in Shiraz, Iran, for children, adolescents, and adults. The results show that the concentration of Al in the drinking water in Shiraz varies significantly between winter and summer seasons and varies considerably spatially across the city irrespective of the season. However, all concentrations are below the guideline concentration. The HRA results show that the highest health risk is for children in summer, and the lowest is for adolescents and adults during winter, with generally higher health risks for younger age groups. However, Monte Carlo results for all age groups suggest no adverse health effects due to Al exposure. The sensitivity analysis shows that the sensitive parameters vary across age groups. For example, the Al concentration and ingestion rate pose the most risk for adolescent and adult groups, and children group, respectively. More importantly, the interaction of Al concentration with ingestion rate and body weight is the controlling parameters for evaluating HRA rather than Al concentration alone. We conclude that while the HRA of Al in Shiraz drinking water did not indicate significant health risk, regular monitoring and optimal operation of the coagulation and flocculation processes are essential.


Assuntos
Água Potável , Água Subterrânea , Poluentes Químicos da Água , Criança , Adulto , Adolescente , Humanos , Água Potável/análise , Alumínio/toxicidade , Alumínio/análise , Irã (Geográfico) , Poluentes Químicos da Água/toxicidade , Poluentes Químicos da Água/análise , Medição de Risco , Monitoramento Ambiental/métodos , Água Subterrânea/análise
3.
Food Chem ; 410: 135383, 2023 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-36638629

RESUMO

A nanosensor is designed for rapid detection of the gluten content of wheat-containing samples. Gluten is a plant protein that causes allergy in individuals and leads to celiac disease. Since in a celiac diet trace amounts of gluten are able to prompt allergic reactions, a food-allergen label must be provided on foodstuffs and be seriously considered by food industries. Various analytical methods and commercial immunoassays are used for such analyses but prices per test, especially for low-income countries are high. Thus, a rapid, sensitive, simple, and inexpensive detecting tool seems essential. A solution can be designing a gluten optical nanosensor. The nanosensor is made of folic-acid-carbon dots and gluten molecularly templates embedded simultaneously in a silicate matrix. Adding gluten to the solution of this nanostructure and its adsorbing on the blank templated space on the nanostructure causes fluorescence enhancement. The concentration range of gluten detection was 0.36 to 2.20 µM.


Assuntos
Doença Celíaca , Hipersensibilidade Alimentar , Humanos , Glutens/análise , Carbono/química , Triticum , Dieta , Corantes Fluorescentes/química
4.
Artigo em Inglês | MEDLINE | ID: mdl-35832688

RESUMO

Primary CNS lymphoma presents unique challenges for the clinician. New evidence has emerged regarding the appropriate workup, management considerations, and treatment. In this paper, we highlight the clinical presentations, disease prognosis, and management considerations. We place specific emphasis on the decision tree for immunocompetent and immunocompromised. The key imaging characteristics are discussed. Once biopsy prove lymphoma, important management considerations are addressed. We highlight need for follow up and role for surgery verse radiation. Finally, we present emerging treatment options and pre-clinical work that will be making its way through the pipeline. This up-to-date review will serve as a key learning tool for clinicians and researchers.

5.
J Chromatogr A ; 1627: 461413, 2020 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-32823111

RESUMO

Innovations in extraction phases, extraction modes and hyphenated instrument configurations, are the most important issues to address for progress in the solid phase microextraction (SPME) methodology. In this regard, we have embarked on the development of a novel biocompatible 96-monolithic inorganic hollow fiber (96-MIHF) array as a new configuration for high-throughput SPME on a 96-well plate system. An arrangement of highly ordered 96 titania/Hydroxyapatite (TiO2/HAP) nanocomposite hollow fibers and corresponding stainless-steel needles on a Teflon plate holder were used as the extraction module. The inorganic hollow fibers were prepared via a rapid and reproducible template approach (Polypropylene hollow fiber) in combination with a sol-gel method in the presence of polyvinyl alcohol (PVA), as a network maker. The hollow fiber-shape sorbents were obtained with excellent precision by weight (RSD% = 4.98, n = 10) and length (RSD% = 1.08, n = 10) criteria. The proposed design can overcome a number of geometrically dependent drawbacks of conventional high-throughput SPME methods, mainly the ones related to sorbent amount and surface area due to possessing inner/outer surfaces without additional internal supports. The SPME platform, for the first time, was successfully applied for the extraction and preconcentration of doxorubicin from urine and water media without requiring sample preparation and free from significant matrix effect. The extracted analyte was analyzed by liquid chromatography-ion trap tandem mass spectrometry (LC-MS/MS). Highly satisfactory analytical figures of merit were obtained under optimized conditions. The limit of detection (LOD), limit of quantification (LOQ) and linearity of determination were 0.1 ng mL-1, 0.25 ng mL-1 and 0.25 to 4000 ng mL-1, respectively. The interday, intraday and inter sorbent precisions for three concentration levels ranged from 2.01 to 8.09 % (n = 3), 1.02 to 8.65 % (n = 5) and 0.99 to 1.02% (n = 15), respectively. The mean intra-well RSD value for 96 individual wells in 96-MIHF-SPME-LC-MS/MS (n = 3) at the medium concentration level was 7.81%.


Assuntos
Cromatografia Líquida/métodos , Doxorrubicina/urina , Microextração em Fase Sólida/métodos , Espectrometria de Massas em Tandem/métodos , Água/química , Adolescente , Adulto , Daunorrubicina/urina , Feminino , Humanos , Concentração de Íons de Hidrogênio , Limite de Detecção , Masculino , Pessoa de Meia-Idade , Concentração Osmolar , Polipropilenos/química , Porosidade , Reprodutibilidade dos Testes , Fatores de Tempo , Adulto Jovem
6.
J Mol Model ; 25(6): 163, 2019 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-31098854

RESUMO

Hydrogen cyanide (HCN) adsorption on pristine and B-N doped biphenylene nanosheets was investigated by means of density functional theory calculations. According to biphenylene geometry, all distinct possible B-N substitutions were designed. Adsorption energy and electronic structure at the level of M062X/6-31 g (d,p) theory were computed for all possible geometries. Our results reveal that pristine biphenylene nanosheet is not a suitable candidate for HCN detection. Also, for B-N doping, the sensitivity of the nanosheet depends on the B-N doped configuration. One of these derivative structures shows higher sensitivity to HCN adsorption due to the greater change in electronic properties. Moreover, atoms in molecules and natural bond orbital analysis were performed to obtain more in-depth knowledge about the adsorption mechanism. The range of energy for interaction between HCN and the nanosheets belongs to physical adsorption.

7.
Biomed Res Int ; 2019: 7167525, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30863780

RESUMO

Effects of in ovo injection of Q10 on hatchability, performance (feed intake (FI), body weight gain (BWG), feed/gain ratio (F/G)) traits, and immune status of Ross × Ross 308 broiler chicks, hatched from eggs laid by a 38-week-old breeder flock, were determined through 42 days after hatch. Eggs containing live embryos were injected in the amnion with 0.1 and 0.2 mL Q10 solution on day 18 of incubation. Two controls groups were included as sham and/or as an uninjected group. At 28 and 42 days of age, performance traits, serum enzyme activity, weights of immune organs, and serum antibody titer of viral diseases were determined. Results were shown that hatchability % increased by Q10 on average of 6.54% (P≤0.025) and body weight/egg weight after hatching increased up to 4.74% (P≤0.002), compared with uninjected and sham controls. Injection of Q10 at different levels led to significant increases (P≤0.001) in performance traits all over the rearing period (P<0.05). Weight of immune organs significantly improved compared to uninjected and sham controls (P<0.05). In addition, serum antibody titers of viral diseases as well as serum enzyme activity of AST, ALT, CAT, and SOD were significantly changed by Q10 treated groups than controls (P≤0.01). In conclusion, in ovo injection of Q10 at levels of 0.1 and 0.2 mL led to significant increases in hatchability%, internal egg characteristics, and performance parameters as well as serum enzyme activity, weight of immune organs, and serum antibody titer of ND, AI, and IBD diseases.


Assuntos
Galinhas/crescimento & desenvolvimento , Ovos , Óvulo/efeitos dos fármacos , Ubiquinona/análogos & derivados , Animais , Peso Corporal/efeitos dos fármacos , Ingestão de Alimentos/efeitos dos fármacos , Feminino , Injeções , Fígado/efeitos dos fármacos , Fígado/crescimento & desenvolvimento , Fígado/metabolismo , Óvulo/crescimento & desenvolvimento , Ubiquinona/administração & dosagem
8.
Phys Chem Chem Phys ; 20(47): 29889-29895, 2018 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-30468442

RESUMO

The electronic properties, adsorption energies and energy barrier of sodium ion diffusion in B-doped graphyne (BGY) are studied by density functional theory (DFT) method. If some carbon atoms in pristine graphyne (GY) are substituted by boron atoms (one substitution per unit cell in this work), BGY is obtained, and the band structure and density of state (DOS) plots indicate a transition from a semiconductive state for GY to a metallic state for BGY. The calculated adsorption energy shows an improvement in the trigonal-like pore (T site) and hexagonal ring (H site) adsorption of BGY compared to the corresponding analog sites in GY. The comparison of projected density of state (PDOS) plots before and after adsorption reveals charge transfer from sodium to nanosheets. Therefore, the interaction between adsorbed sodium atom and BGY/GY has ionic character and not covalent. This phenomenon is important for the reversible sodium adsorption in secondary batteries. Moreover, PDOS plots show that the electron transfer from sodium atom to host structure in BGY is more than in GY, which is in agreement with adsorption energies. According to diffusion energy barrier calculations, boron atoms in BGY structure provide low energy paths for sodium ions diffusion. We estimate a theoretical capacity of 751 mA h g-1 for the maximum sodium adsorption on BGY (without cluster formation). Therefore, BGY is a promising anode material for sodium ion batteries (SIBs).

9.
Anal Bioanal Chem ; 408(24): 6769-79, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27497964

RESUMO

In this research, an electrochemical sensor based on molecularly imprinted polymer (MIP) nanoparticles for selective and sensitive determination of diazinon (DZN) pesticides was developed. The nanoparticles of diazinon imprinted polymer were synthesized by suspension polymerization and then used for modification of carbon paste electrode (CPE) composition in order to prepare the sensor. Cyclic voltammetry (CV) and square wave voltammetry (SWV) methods were applied for electrochemical measurements. The obtained results showed that the carbon paste electrode modified by MIP nanoparticles (nano-MIP-CP) has much higher adsorption ability for diazinon than the CPE based non-imprinted polymer nanoparticles (nano-NIP-CP). Under optimized extraction and analysis conditions, the proposed sensor exhibited excellent sensitivity (95.08 µA L µmol(-1)) for diazinon with two linear ranges of 2.5 × 10(-9) to 1.0 × 10(-7) mol L(-1) (R (2) = 0.9971) and 1.0 × 10(-7) to 2.0 × 10(-6) mol L(-1) (R (2) = 0.9832) and also a detection limit of 7.9 × 10(-10) mol.L(-1). The sensor was successfully applied for determination of diaznon in well water and apple fruit samples with recovery values in the range of 92.53-100.86 %. Graphical abstract Procedure for preparation of electrochemical sensor based on MIP nanoparticles for determination of diazinon.


Assuntos
Diazinon/análise , Técnicas Eletroquímicas/métodos , Malus/química , Impressão Molecular/métodos , Nanopartículas/química , Praguicidas/análise , Poluentes Químicos da Água/análise , Carbono/química , Eletrodos , Análise de Alimentos/métodos , Frutas/química , Limite de Detecção , Polimerização , Polímeros/química , Água/análise
10.
Rev. colomb. ciencias quim. farm ; 45(2): 234-242, ene.-mayo 2016. graf
Artigo em Português | LILACS | ID: biblio-830310

RESUMO

O desempenho de poli-2-mercaptobenzimidazol na detecção eletroquímica de colesterol foi avaliado fenomenológica e matematicamente. O modelo matemático correspondente foi desenvolvido e analisado por meio de teoria de estabilidade lineal e análise de bifurcações. Os dados teóricos foram comparados com os experimentais e com os teóricos para os sistemas análogos.


The electroanalytical function of poly-2-mercaptobenzimidazole in cholesterol electrochemical detection was evaluated phenomenologically and mathematically. The corresponding mathematical model was developed and analyzed by linear stability theory and bifurcation analysis. The theoretical data were compared with the experimental data and with theoretical data for analogous systems.

11.
J Stroke Cerebrovasc Dis ; 24(2): 408-15, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25511616

RESUMO

BACKGROUND: Insufficient information is available on the barriers that explain low rates of thrombolytic therapy for acute ischemic stroke (AIS) in developing countries compared with rates in developed societies. By the present study, we aimed to assess the implementation of thrombolytic therapy in the northeast of Iran to explore the gaps and hurdles against thrombolysis as the generally accepted treatment for AIS. METHODS: In a 1-year cohort study among AIS patients admitted to the second largest tertiary neurologic referral center in Iran, those who met the prespecified selection criteria were treated with intravenous recombinant tissue plasminogen activator (rtPA). RESULTS: Among 1,144 patients admitted with AIS, only 14 (1.2%) were treated with rtPA. The mean onset-to-needle and door-to-needle times were 172 and 58 minutes, respectively; 980 (85.6%) patients were initially excluded from the study because of late arrival. Additionally, 60 patients in total were omitted because of either their high age (3.7%) or passing the gold standard time limit for rtPA therapy after preliminary evaluations (1.6%), and 90 more patients (7.9%) were considered not suitable for thrombolysis because of the severity of the symptoms or the higher risk of bleeding on rtPA. CONCLUSIONS: Access to thrombolytic therapy for AIS in Iran is less than in most developed countries but comparable with other developing countries. Awareness campaigns are needed to minimize barriers and improve access to thrombolysis and specialized stroke care in Iran.


Assuntos
Isquemia Encefálica/tratamento farmacológico , Fidelidade a Diretrizes , Guias de Prática Clínica como Assunto , Acidente Vascular Cerebral/tratamento farmacológico , Terapia Trombolítica/normas , Adulto , Idoso , Feminino , Fibrinolíticos/administração & dosagem , Fibrinolíticos/uso terapêutico , Humanos , Irã (Geográfico) , Masculino , Pessoa de Meia-Idade , Fatores de Tempo , Ativador de Plasminogênio Tecidual/administração & dosagem , Ativador de Plasminogênio Tecidual/uso terapêutico
12.
Talanta ; 129: 309-14, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25127600

RESUMO

Continuous sample drop flow-based microextraction (CSDF-ME) is an improved version of continuous-flow microextraction (CFME) and a novel technique developed for extraction and preconcentration of benzene, toluene, ethyl benzene, m-xylene and o-xylene (BTEXs) from aqueous samples prior to gas chromatography-flame ionization detection (GC-FID). In this technique, a small amount (a few microliters) of organic solvent is transferred to the bottom of a conical bottom test tube and a few mL of aqueous solution is moved through the organic solvent at relatively slow flow rate. The aqueous solution transforms into fine droplets while passing through the organic solvent. After extraction, the enriched analyte in the extraction solvent is determined by GC-FID. The type of extraction solvent, its volume, needle diameter, and aqueous sample flow rate were investigated. The enrichment factor was 221-269 under optimum conditions and the recovery was 89-102%. The linear ranges and limits of detection for BTEXs were 2-500 and 1.4-3.1 µg L(-1), respectively. The relative standard deviations for 10 µg L(-1) of BTEXs in water were 1.8-6.2% (n=5). The advantages of CSDF-ME are its low cost, relatively short sample preparation time, low solvent consumption, high recovery, and high enrichment factor.


Assuntos
Microextração em Fase Líquida/métodos , Compostos Orgânicos/química , Poluentes Químicos da Água/química , Automação , Benzeno/química , Derivados de Benzeno/química , Clorofórmio/química , Cromatografia Gasosa/métodos , Monitoramento Ambiental , Ionização de Chama/métodos , Irã (Geográfico) , Reprodutibilidade dos Testes , Rios/química , Solventes/química , Tolueno/química , Água/química , Xilenos/química
13.
Anal Chim Acta ; 702(2): 274-9, 2011 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-21839209

RESUMO

In this study, ultrasonic assisted miniaturized matrix solid-phase dispersion (US-MMSPD) combined with homogeneous liquid-liquid extraction (HLLE) has been developed as a new method for the extraction of organochlorinated pesticides (OCPs) in fish prior to gas chromatography with electron capture detector (GC-ECD). In the proposed method, OCPs (heptachlor, aldrin, DDE, DDD, lindane and endrin) were first extracted from fish sample into acetonitrile by US-MMSPD procedure, and the extract was then used as consolute solvent in HLLE process. Optimal condition for US-MMSPD step was as follows: volume of acetonitrile, 1.5 mL; temperature of ultrasound, 40°C; time of ultrasound, 10 min. For HLLE step, optimal results were obtained at the following conditions: volume of chloroform, 35 µL; volume of aqueous phase, 1.5 mL; volume of double distilled water, 0.5 mL; time of centrifuge, 10 min. Under the optimum conditions, the enrichment factors for the studied compounds were obtained in the range of 185-240, and the overall recoveries were ranged from 39.1% to 81.5%. The limits of detection were 0.4-1.2 ng g(-1) and the relative standard deviations for 20 ng g(-1) of the OCPs, varied from 3.2% to 8% (n=4). Finally, the proposed method has been successfully applied to the analysis of the OCPs in real fish sample, and satisfactory results were obtained.


Assuntos
Cromatografia Gasosa/métodos , Peixes/metabolismo , Hidrocarbonetos Clorados/análise , Extração Líquido-Líquido/métodos , Praguicidas/análise , Ultrassom/métodos , Acetonitrilas/química , Animais , Clorofórmio/química , Hidrocarbonetos Clorados/química , Limite de Detecção , Microquímica/métodos , Praguicidas/química , Solventes/química , Temperatura , Fatores de Tempo , Água/química
14.
Food Chem ; 126(4): 1840-4, 2011 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-25213965

RESUMO

A very simple and economic method for organophosphorus pesticides (OPPs) residues analysis in tomato by means of gas chromatography-flame photometric detection (GC-FPD) has been developed. The method involves a rapid and small-scale extraction. The sample was homogenised and extraction of the OPPs with acetone was carried out assisted by sonication. No clean-up or evaporation were required after extraction. Pre-concentration of the OPPs from the acetone extract was done by using dispersive liquid-liquid microextraction (DLLME) technique. Chlorobenzene was added in micro-level volume as extraction solvent and triphenylphosphate as internal standard in DLLME procedure. The method showed good linearity over the range assayed (0.5-1000µgkg(-1)) and the detection limits for the pesticides studied varied from 0.1 to 0.5µgkg(-1). Repeatability studies resulted a relative standard deviation lower than 10% in all cases. The proposed method was used to determine pesticides levels in tomatoes grown in open field.

15.
ARYA Atheroscler ; 6(3): 90-3, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-22577422

RESUMO

BACKGROUND: Migraine Induced Stroke (MIS) is an important cause of brain infarction in the young people. METHODS: Consecutive patients with MIS admitted in Ghaem hospital, Mashhad during 2006-2010 enrolled a prospective clinical study. All of the patients suspected to MIS had brain MRI with a 0.5 Tesla generation, Philips NT Intra, Netherland. All of the MIS patients underwent a standard battery of diagnostic investigations for detecting etiology of stroke. Disability of MIS patients was detected based on the modified Rankin scale at 90 days post stroke. RESULTS: 32 MIS patients (18 females, 14 males) with mean age 37.2 ± 3.8 years ranged 15-58 years were evaluated. Hypodense area of infarction corresponding to clinical manifestations was detected in MRI in 32% of our MIS patients. The mean disability score in our MIS patients was 1.09 ± 0.32, which is significantly lower than other stroke patients (z = 2.55, P = 0.007) CONCLUSION: MIS is an important cause of stroke in Persian young adults which have good prognosis.

16.
Bioelectrochemistry ; 77(2): 120-4, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19674943

RESUMO

Electrochemical oxidation of glucose on a glassy carbon disc electrode modified with multi-walled carbon nanotubes and nickel(II) oxide (GC/MWCNT/NiO) was examined by cyclic voltammetry and chronoamperometry in alkaline aqueous solutions. The results were compared with those obtained on a nickel(II) oxide modified glassy carbon electrode (GC/NiO). Both electrodes conditioned by potential cycling in a limited potential range (0.1-0.6 V vs. Ag/AgCl) in 0.10 M NaOH solution. It was found that the multi-walled carbon nanotubes improve remarkably the reactivity of nickel(II) oxide for glucose oxidation. The GC/MWCNT/NiO electrode exhibited good linear behavior in the concentration range from 2.0x10(-4) mol/L to 1.2x10(-2) mol/L for the quantitative analysis of glucose with a limit of detection of 1.6x10(-4) mol/L (3sigma). The prepared electrode exhibits satisfactory stability and long life if stored at ambient conditions. Finally, it has been demonstrated that the proposed modified electrode can be successfully used for the assay of glucose in serum samples.


Assuntos
Técnicas Eletroquímicas/instrumentação , Glucose/análise , Glucose/química , Nanotubos de Carbono/química , Níquel/química , Óxidos/química , Glicemia/análise , Técnicas Eletroquímicas/métodos , Eletrodos , Vidro/química , Concentração de Íons de Hidrogênio , Limite de Detecção , Oxirredução , Soluções/química
17.
J Hazard Mater ; 169(1-3): 907-11, 2009 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-19467774

RESUMO

In this article, a new method for the determination of organophosphorus pesticides (OPPs) in tea was developed by using dispersive liquid-liquid microextraction (DLLME) and gas chromatography-flame photometric detection (GC-FPD). A mixture of acetonitrile and n-hexane was used as an extraction solvent for the extraction of OPPs from tea samples. When the extraction process was finished, the mixture of solvents was rapidly dispersed in water; target analyte was extracted to a small volume of n-hexane, using DLLME. Recovery tests were performed for concentration 5.0 microg/kg. The recovery for each target analyte was in the range between 83.3 and 117.4%. The repeatability of the proposed method, expressed as relative standard deviation, varied between 3 and 7.8% (n=3). The detection limit of the method for tea was found ranging from 0.030 to 1 microg/kg for all the target pesticides. Compared with the conventional sample preparation method, the proposed method has the advantage of being quick and easy to operate, and has high-enrichment factors and low consumption of organic solvent.


Assuntos
Fracionamento Químico/métodos , Praguicidas/análise , Chá/química , Cromatografia Gasosa , Contaminação de Alimentos/análise , Compostos Organofosforados/análise , Compostos Organofosforados/isolamento & purificação , Praguicidas/isolamento & purificação , Solventes
18.
Arch Iran Med ; 12(3): 225-31, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19400598

RESUMO

BACKGROUND: Hepatitis B virus infection is a very common cause of chronic liver disease worldwide. It is estimated that 3% of Iranians are chronically infected with hepatitis B virus. Current population-based studies on both rural and urban prevalence of hepatitis B virus infection in Iran are sparse with results that do not always agree. We performed this study to find the prevalence of hepatitis B surface antigen, anti-hepatitis B core antibody, and associated factors in the general population of three provinces of Iran. METHODS: We randomly selected 6,583 subjects from three provinces in Iran, namely Tehran, Golestan, and Hormozgan. The subjects were aged between 18 and 65 years. Serum samples were tested for hepatitis B surface antigen and anti-hepatitis B core antibody. Various risk factors were recorded and multivariate analysis was performed. RESULTS: The prevalence of hepatitis B surface antigen and anti-hepatitis B core antibody in Iran was 2.6% and 16.4%, respectively. Predictors of hepatitis B surface antigen or anti-hepatitis B core antibody in multivariate analysis included older age, not having high-school diploma, living in a rural area, and liver disease in a family member. We did not find any significant differences between males and females. CONCLUSION: In spite of nationwide vaccination of newborns against hepatitis B virus since 1992, hepatitis B virus infection remains a very common cause of chronic liver disease in Iran which should be dealt with for at least the next 30-50 years.


Assuntos
Anticorpos Anti-Hepatite B/análise , Antígenos de Superfície da Hepatite B/análise , Vírus da Hepatite B/imunologia , Hepatite B/epidemiologia , Vigilância da População , Adolescente , Adulto , Distribuição por Idade , Idoso , Estudos Transversais , Feminino , Hepatite B/imunologia , Hepatite B/virologia , Humanos , Irã (Geográfico)/epidemiologia , Masculino , Pessoa de Meia-Idade , Prevalência , Distribuição por Sexo , Adulto Jovem
19.
J Chromatogr A ; 1193(1-2): 19-25, 2008 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-18452930

RESUMO

Dispersive liquid-liquid microextraction and gas chromatography-flame photometric detection (DLLME-GC-FPD) were performed for the speciation of butyl and phenyltin compounds in water samples after derivatization with sodium tetraethylborate (NaBEt4). Some important parameters, such as pH, amount of NaBEt4, derivatization time, kind and volume of extraction and disperser solvents, extraction time and salt effect were investigated and optimized. High enrichment factors (825-1036) and low detection limits (0.2-1 ng L(-1)) were obtained under the optimum conditions. The calibration graphs were linear in the range of 0.5-1000 ng L(-1) (as Sn) for the target analytes. The relative standard deviations (RSDs) for the extraction of 20 ng L(-1) (as Sn) of butyl and phenyltin compounds varied from 2.3 to 5.9% (n=7) and from 4.1 to 8.8% (n=7) with and without using internal standard, respectively. Seawater and river water samples were successfully analyzed using the proposed method and the relative recoveries of the studied compounds in the water samples, at spiking levels of 10.0 and 100 ng L(-1) (as Sn) were obtained to be 82.5-104.7%.


Assuntos
Cromatografia Gasosa/métodos , Compostos Orgânicos de Estanho/análise , Padrões de Referência
20.
Talanta ; 75(1): 56-62, 2008 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-18371847

RESUMO

The need for highly reliable methods for the determination of trace and ultratrace elements has been recognized in analytical chemistry and environmental science. A simple and powerful microextraction technique was used for the detection of the lead ultratrace amounts in water samples using the dispersive liquid-liquid microextraction (DLLME), followed by the electrothermal atomic absorption spectrometry (ET AAS). In this microextraction technique, a mixture of 0.50 mL acetone (disperser solvent), containing 35 microL carbon tetrachloride (extraction solvent) and 5 microL diethyldithiophosphoric acid (chelating agent), was rapidly injected by syringe into the 5.00 mL water sample, spiked with lead. In this process, the lead ions reacted with the chelating agent and were extracted into the fine droplets of CCl(4). After centrifugation (2 min at 5000 rpm), the fine CCl4 droplets were sedimented at the bottom of the conical test tube (25+/-1 microL). Then, 20 microL from the sedimented phase, containing the enriched analyte, was determined by ET AAS. The next step was the optimization of various experimental conditions, affecting DLLME, such as the type and the volume of the extraction solvent, the type and the volume of the disperser solvent, the extraction time, the salt effect, pH and the chelating agent amount. Moreover, the effect of the interfering ions on the analytes recovery was also investigated. Under the optimum conditions, the enrichment factor of 150 was obtained from only a 5.00 mL water sample. The calibration graph was linear in the range of 0.05-1 microg L(-1) with the detection limit of 0.02 microg L(-1). The relative standard deviation (R.S.D.) for seven replicate measurements of 0.50 microg L(-1) of lead was 2.5%. The relative lead recoveries in mineral, tap, well and sea water samples at the spiking level of 0.20 and 0.40 microg L(-1) varied from 93.5 to 105.0. The characteristics of the proposed method were compared with the cloud point extraction (CPE), the liquid-liquid extraction, the solid phase extraction (SPE), the on-line solid phase extraction (SPE) and the co-precipitation, based on bibliographic data. The main DLLME advantages combined with ET AAS were simplicity of operation, rapidity, low cost, high-enrichment factor, good repeatability, low consumption of extraction solvent, requiring a low sample volume (5.00 mL).

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