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1.
Anal Bioanal Chem ; 412(20): 4967-4983, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32524371

RESUMO

In this study, we developed and validated a CE-TOF-MS method for the quantification of glyphosate (N-(phosphonomethyl)glycine) and its major degradation product aminomethylphosphonic acid (AMPA) in different samples including beer, media from toxicological analysis with Daphnia magna, and sorption experiments. Using a background electrolyte (BGE) of very low pH, where glyphosate is still negatively charged but many matrix components become neutral or protonated, a very high separation selectivity was reached. The presence of inorganic salts in the sample was advantageous with regard to preconcentration via transient isotachophoresis. The advantages of our new method are the following: no derivatization is needed, high separation selectivity and thus matrix tolerance, speed of analysis, limits of detection suitable for many applications in food and environmental science, negligible disturbance by metal chelation. LODs for glyphosate were < 5 µg/L for both aqueous and beer samples, the linear range in aqueous samples was 5-3000 µg/L, for beer samples 10-3000 µg/L. For AMPA, LODs were 3.3 and 30.6 µg/L, and the linear range 10-3000 µg/L and 50-3000 µg/L, for aqueous and beer samples, respectively. Recoveries in beer samples for glyphosate were 94.3-110.7% and for AMPA 80.2-100.4%. We analyzed 12 German and 2 Danish beer samples. Quantification of glyphosate and AMPA was possible using isotopically labeled standards without enrichment, purification, or dilution, only degassing and filtration were required for sample preparation. Finally, we demonstrate the applicability of the method for other strong acids, relevant in food and environmental sciences such as N-acetyl glyphosate, N-acetyl AMPA (present in some glyphosate resistant crop), trifluoroacetic acid, 2-methyl-4-chlorophenoxyacetic acid, glufosinate and its degradation product 3-(methylphosphinico)propionic acid, oxamic acid, and others.


Assuntos
Cerveja/análise , Eletroforese Capilar/métodos , Poluentes Ambientais/análise , Glicina/análogos & derivados , Herbicidas/análise , Espectrometria de Massas/métodos , Glicina/análise , Limite de Detecção , Reprodutibilidade dos Testes , Espectrofotometria Ultravioleta , Glifosato
2.
Wien Med Wochenschr ; 160(3-4): 94-100, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20300927

RESUMO

The 11th meeting of the International Scientific Working Group on Tick-borne Encephalitis (ISW-TBE) was conducted under the title of, "From childhood to golden age: increased mobility - increased risk of contracting TBE?" Participants from 26 countries, including the United States of America and China, presented reports on the latest developments and trends in local TBE cases, vaccination coverage and risk factors. In particular, the situation of children and the elderly (the "golden agers") was discussed. As the current evidence suggests, the location and extension of endemic areas for TBE have changed over the last few years, along with global warming and the shift of infected ticks to higher altitudes. The increased mobility of the human population adds to the heightened exposure; outdoor activities and international travel are on the rise also, and especially, amongst the 50+ generation, who are already per se at higher risk of disease manifestation, complications and case fatality. Most Europeans travel within Europe, often without sufficient awareness of endemic areas. Only high immunization rates can ensure low disease rates in the long run. To achieve this goal, public education is the sole effective approach for raising the level of awareness. Overall, the risk of any given person to contract TBE should not be regarded as a fixed entity, but rather it must be estimated individually, on the basis of knowledge of the TBE virus endemic areas and risk factors.


Assuntos
Comparação Transcultural , Encefalite Transmitida por Carrapatos/epidemiologia , Encefalite Transmitida por Carrapatos/transmissão , Doenças Endêmicas , Dinâmica Populacional , Viagem , Idoso , Criança , Estudos Transversais , Vírus da Encefalite Transmitidos por Carrapatos , Encefalite Transmitida por Carrapatos/diagnóstico , Encefalite Transmitida por Carrapatos/prevenção & controle , Europa (Continente) , Aquecimento Global , Humanos , Atividades de Lazer , Fatores de Risco , Vacinas Virais/administração & dosagem
3.
Anal Chem ; 81(15): 6165-74, 2009 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-19522513

RESUMO

We describe a sheath flow capillary electrophoresis time-of-flight mass spectrometry (CE-TOFMS) method in the negative mode using a platinum electrospray ionization (ESI) spray needle, which allows the comprehensive analysis of anionic metabolites. The material of the spray needle had significant effect on the measurement of anions. A stainless steel spray needle was oxidized and corroded at the anodic electrode due to electrolysis. The precipitation of iron oxides (rust) plugged the capillary outlet, resulting in shortened capillary lifetime. Many anionic metabolites also formed complexes with the iron oxides or migrating nickel ion, which was also generated by electrolysis and moved toward the cathode (the capillary inlet). The metal-anion complex formation significantly reduced detection sensitivity of the anionic compounds. The use of a platinum ESI needle prevented both oxidation of the metals and needle corrosion. Sensitivity using the platinum needle increased from several- to 63-fold, with the largest improvements for anions exhibiting high metal chelating properties such as carboxylic acids, nucleotides, and coenzyme A compounds. The detection limits for most anions were between 0.03 and 0.87 micromol/L (0.8 and 24 fmol) at a signal-to-noise ratio of 3. This method is quantitative, sensitive, and robust, and its utility was demonstrated by the analysis of the metabolites in the central metabolic pathways extracted from mouse liver.


Assuntos
Ânions/análise , Eletroforese Capilar/métodos , Hepatócitos/efeitos dos fármacos , Espectrometria de Massas , Metabolômica , Animais , Biomarcadores/análise , Hepatócitos/citologia , Hepatócitos/metabolismo , Camundongos , Platina/química , Sensibilidade e Especificidade , Aço Inoxidável/química
4.
Int J Cancer ; 123(9): 2048-56, 2008 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-18709643

RESUMO

In a study on gene deregulation in ovarian carcinoma we found a mRNA coding for a 350 kDa protein, Drop1, to be downregulated 20- to 180-fold in the majority of ovarian and mammary carcinomas. The mRNA is encoded by a set of exons in the 5' region of the SYNE1 gene. Immunohistochemical staining for Drop1 protein by a specific monoclonal antibody corresponds to the pattern seen for the mRNA. cDNA arrays of matched pairs of tumor and normal tissue and in situ hybridizations confirmed the drastic loss of Drop1 mRNA as a common feature in uterus, cervix, kidney, lung, thyroid and pancreas carcinomas, already at early tumor stages and in all metastases. Two-hybrid studies suggest a role of this deficiency in the malignant progression of epithelial tumors.


Assuntos
Regulação Neoplásica da Expressão Gênica , Neoplasias/genética , Proteínas do Tecido Nervoso/genética , Proteínas Nucleares/genética , Neoplasias da Mama/genética , Linhagem Celular Tumoral , Proteínas do Citoesqueleto , Éxons , Feminino , Humanos , Estadiamento de Neoplasias , Neoplasias/patologia , Análise de Sequência com Séries de Oligonucleotídeos , Neoplasias Ovarianas/genética , RNA Mensageiro/análise , Técnicas do Sistema de Duplo-Híbrido
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