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1.
Mar Drugs ; 18(12)2020 Dec 18.
Artículo en Inglés | MEDLINE | ID: mdl-33352941

RESUMEN

Fungi are a prospective resource of bioactive compounds, but conventional methods of drug discovery are not effective enough to fully explore their metabolic potential. This study aimed to develop an easily attainable method to elicit the metabolic potential of fungi using Aspergillus nidulans laeA as a transcription regulation tool. In this study, functional analysis of Aspergillus nidulans laeA (AnLaeA) and Aspergillus sp. Z5 laeA (Az5LaeA) was done in the fungus Aspergillus sp. Z5. Heterologous AnLaeA-and native Az5LaeA-overexpression exhibited similar phenotypic effects and caused an increase in production of a bioactive compound diorcinol in Aspergillus sp. Z5, which proved the conserved function of this global regulator. In particular, heteroexpression of AnLaeA showed a significant impact on the expression of velvet complex genes, diorcinol synthesis-related genes, and different transcription factors (TFs). Moreover, heteroexpression of AnLaeA influenced the whole genome gene expression of Aspergillus sp. Z5 and triggered the upregulation of many genes. Overall, these findings suggest that heteroexpression of AnLaeA in fungi serves as a simple and easy method to explore their metabolic potential. In relation to this, AnLaeA was overexpressed in the fungus Penicillium sp. LC1-4, which resulted in increased production of quinolactacin A.


Asunto(s)
Aspergillus nidulans/genética , Aspergillus nidulans/metabolismo , Regulación Fúngica de la Expresión Génica/fisiología , Metabolismo Secundario/fisiología , Regulación hacia Arriba/fisiología , Animales , Biología Computacional/métodos , Caracol Conus , Proteínas Fúngicas/biosíntesis , Proteínas Fúngicas/genética , Perfilación de la Expresión Génica/métodos
2.
Exp Ther Med ; 20(2): 1441-1446, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32742377

RESUMEN

Sequential invasive-noninvasive ventilation (NIV) improves the outcomes of patients with respiratory failure caused by acute exacerbation of chronic obstructive pulmonary disease (AECOPD); however, there is no clear consensus on the optimal timing of the switch to sequential invasive-NIV in these patients. In the present study, a potential role for the modified Glasgow Coma Scale (GCS) score to guide sequential weaning was investigated. Patients with AECOPD and respiratory failure were prospectively recruited from three study centers (Wenling Hospital Affiliated to Wenzhou Medical University, the First Affiliated Hospital of Wenzhou Medical University and Changsha Central Hospital) between January 1st 2016 and December 31st 2018. Patients were randomly assigned to group A and B, with the switching point for sequential weaning strategy in the two groups being a modified GCS score ≥13 and 10 points, respectively. Each group included 240 patients. Baseline demographic characteristics were comparable in the two groups. The duration of invasive mechanical ventilation (IMV) in group A was significantly shorter than that in group B. However, there were no significant between-group differences with respect to the incidence of re-intubation, ventilator-associated pneumonia, in-hospital mortality or the length of hospital stay. Use of a modified GCS score ≥13 as the switching point for sequential invasive-NIV may help decrease the duration of IMV in patients with AECOPD and respiratory failure.

3.
Curr Microbiol ; 77(10): 2925-2932, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32661679

RESUMEN

A novel bacterium designated SSM4.2T was isolated from seaweed of Gouqi Island, which is the center of the Zhoushan fishing ground in the East China Sea. Strain SSM4.2T was Gram-stain-negative, bright yellow-pigmented, short rod-shaped, non-flagellated, non-spore forming, aerobic and motile by gliding. Growth was observed at 4-37 °C (optimum 25-30 °C), pH 6.0-8.0 (optimum pH 7.0) and 0-2.0% (w/v) NaCl (optimum 0%) concentration. The strain was catalase- and oxidase-positive. Menaquinone-6 (MK-6) was found as the sole respiratory quinone and zeaxanthin as the main carotenoid pigment. The predominant fatty acids (≥ 10%) were iso-C15:0, iso-C15:1 G, iso-C17:0 3-OH and summed feature 3 (C16:1 ω7c /C16:1 ω6c). The major polar lipid was phosphatidylethanolamine (PE). The genome size was 5.7 Mbp. The DNA G + C content was 34.1 mol%. 16S rRNA gene sequence revealed that strain SSM4.2T belongs to the genus Flavobacterium and shares high-sequence similarity with F. limi KACC 18851T (98.1%), F. hydrophilum KACC 19591T (97.6%), F. defluvii KCTC 12612T (97.1%), F. cheongpyeongense KACC 19592T (97.0%) and F. fluviatile KCTC 52446T (96.9%). Strain SSM4.2T had 73.2-84.6% average nucleotide identity and 19.1-29.4% digital DNA-DNA hybridization values with its closest type strains. Based on its phenotypic, chemotaxonomic, phylogenetic and genomic features, strain SSM4.2T represents a novel species of the genus Flavobacterium, for which the name Flavobacterium ajazii sp. nov. is proposed. The type strain is SSM4.2T (= KCTC 72807T = MCCC 1K04370T).


Asunto(s)
Flavobacterium , Filogenia , Algas Marinas , China , Ácidos Grasos/análisis , Flavobacterium/clasificación , Flavobacterium/genética , Flavobacterium/aislamiento & purificación , Islas , ARN Ribosómico 16S/genética , Algas Marinas/microbiología , Especificidad de la Especie , Vitamina K 2/análisis
4.
Int J Syst Evol Microbiol ; 70(7): 4250-4260, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32568031

RESUMEN

Two yellow-pigmented, Gram-stain-negative, aerobic, rod-shaped bacteria were isolated from the water of the hypersaline Chaka Salt Lake (strain SaA2.12T) and sediment of Qinghai Lake (strain LaA7.5T), PR China. According to the 16S rRNA phylogeny, the isolates belong to the genus Flavobacterium, showing the highest 16S rRNA sequence similarities to Flavobacterium arcticum SM1502T(97.6-97.7 %) and Flavobacterium suzhouense XIN-1T(96.5-96.6 %). Moreover, strains SaA2.12T and LaA7.5T showed 99.73 % 16S rRNA sequence similarity to each other. Major fatty acids, respiratory quinones and polar lipids detected in these isolates were iso-C15 : 0, menaquinone-6 and phosphatidylethanolamine, respectively. Strains SaA2.12T and LaA7.5T showed significant unique characteristics between them as well as between the closest phylogenetic members. The highest digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values between SaA2.12T and its closest neighbours were 25.3 and 82.8 %, respectively; whereas these values (highest) between LaA7.5T and its closest members were 25.2 and 82.8 %, respectively. The dDDH and ANI values between strains SaA2.12T and LaA7.5T were calculated as 75.9 and 97.2 %, respectively. Therefore, based on polyphasic data, we propose that strain SaA2.12T represents a novel species with the name Flavobacterium salilacus sp. nov., with the type strain SaA2.12T (=KCTC 72220T=MCCC 1K03618T) and strain LaA7.5T as a subspecies within novel Flavobacterium salilacus with the name Flavobacterium salilacus subsp. altitudinum subsp. nov., with the type strain LaA7.5T (=KCTC 72806T=MCCC 1K04372T). These propositions automatically create Flavobacterium salilacus subsp. salilacus subsp. nov. with SaA2.12T (=KCTC 72220T=MCCC 1K03618T) as the type strain.


Asunto(s)
Flavobacterium/clasificación , Lagos/microbiología , Filogenia , Aguas Salinas , Técnicas de Tipificación Bacteriana , Composición de Base , China , ADN Bacteriano/genética , Ácidos Grasos/química , Flavobacterium/aislamiento & purificación , Hibridación de Ácido Nucleico , Fosfatidiletanolaminas/química , Pigmentación , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Vitamina K 2/análogos & derivados , Vitamina K 2/química
5.
J Microbiol ; 57(12): 1065-1072, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31562606

RESUMEN

A yellow pigmented, Gram-stain-negative, aerobic bacterium designated A5.7T was studied to evaluate the taxonomic position following the modern polyphasic approach. The strain was isolated from sediments near Zhairuo Island, which is situated in the East China Sea. Cells were non-spore forming rods without flagella but showed motility by gliding. Growth was observed at 15-35°C (optimum 28°C), pH 6.0-9.0 (optimum pH 6.5) and 0-2% (w/v) NaCl (optimum 0-0.5%) in LB broth. The major respiratory quinone of A5.7T was menaquinone 6. The major polar lipid of A5.7T was phosphatidylethanolamine and the predominant fatty acids (> 5%) were iso-C15:0, iso-C17:0 3-OH, C15:1ω6c, iso-C15:0 3-OH, iso-C15:1 G, summed feature 3 (C16:1ω7c and/or C16:1ω6c) and summed feature 9 (iso-C17:1ω9c and/or C16:010-methyl). Phylogenetic analysis based on 16S rRNA gene sequences showed that the isolate belongs to the genus Flavobacterium and shares the highest sequence similarities with Flavobacterium sharifuzzamanii A7.6T (98.5%), Flavobacterium tistrianum GB 56.1T (98.3%), Flavobacterium nitrogenifigens NXU-44T (97.8%), Flavobacterium anhuiense D3T (97.6%), Flavobacterium ginsenosidimutans THG 01T (97.6%), and Flavobacterium foetidum CJ42T (97.6%). Digital DNA-DNA hybridization and average nucleotide identity values between the strain and its closest phylogenetic neighbors showed the ranges from 19.6 to 34.1% and 73.7 to 87.9%, respectively. Therefore, based on polyphasic characteristics, strain A5.7T represents a novel species of the genus Flavobacterium for which the name Flavobacterium zhairuonensis sp. nov. is proposed. The type strain is A5.7T (= KCTC 62406T = MCCC 1K03494T).


Asunto(s)
Flavobacterium/clasificación , Flavobacterium/aislamiento & purificación , Sedimentos Geológicos/microbiología , Filogenia , Agua de Mar/microbiología , Técnicas de Tipificación Bacteriana , Composición de Base , China , ADN Bacteriano/genética , Ácidos Grasos/análisis , Flavobacterium/genética , Flavobacterium/fisiología , Genoma Bacteriano/genética , Concentración de Iones de Hidrógeno , Hibridación de Ácido Nucleico , Fosfatidiletanolaminas/análisis , Quinonas/análisis , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Cloruro de Sodio , Temperatura , Vitamina K 2/análogos & derivados , Vitamina K 2/análisis
6.
Appl Environ Microbiol ; 85(18)2019 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-31300396

RESUMEN

Furfural is an important renewable precursor for multiple commercial chemicals and fuels; a main inhibitor existing in cellulosic hydrolysate, which is used for bioethanol fermentation; and a potential carcinogen, as well. Using a genetic system in Saccharomyces cerevisiae that allows detection of crossover events, we observed that the frequency of mitotic recombination was elevated by 1.5- to 40-fold when cells were treated with 0.1 g/liter to 20 g/liter furfural. Analysis of the gene conversion tracts associated with crossover events suggested that most furfural-induced recombination resulted from repair of DNA double-strand breaks (DSBs) that occurred in the G1 phase. Furfural was incapable of breaking DNA directly in vitro but could trigger DSBs in vivo related to reactive oxygen species accumulation. By whole-genome single nucleotide polymorphism (SNP) microarray and sequencing, furfural-induced genomic alterations that range from single base substitutions, loss of heterozygosity, and chromosomal rearrangements to aneuploidy were explored. At the whole-genome level, furfural-induced events were evenly distributed across 16 chromosomes but were enriched in high-GC-content regions. Point mutations, particularly the C-to-T/G-to-A transitions, were significantly elevated in furfural-treated cells compared to wild-type cells. This study provided multiple novel insights into the global effects of furfural on genomic stability.IMPORTANCE Whether and how furfural affects genome integrity have not been clarified. Using a Saccharomyces cerevisiae model, we found that furfural exposure leads to in vivo DSBs and elevation in mitotic recombination by orders of magnitude. Gross chromosomal rearrangements and aneuploidy events also occurred at a higher frequency in furfural-treated cells. In a genome-wide analysis, we show that the patterns of mitotic recombination and point mutations differed dramatically in furfural-treated cells and wild-type cells.


Asunto(s)
Carcinógenos , División Celular/efectos de los fármacos , Furaldehído/efectos adversos , Genoma Fúngico/efectos de los fármacos , Inestabilidad Genómica/efectos de los fármacos , Saccharomyces cerevisiae/efectos de los fármacos , Cromosomas Fúngicos/efectos de los fármacos , Cromosomas Fúngicos/genética , Roturas del ADN de Doble Cadena/efectos de los fármacos , Genoma Fúngico/genética , Saccharomyces cerevisiae/genética
7.
Appl Microbiol Biotechnol ; 103(12): 4869-4880, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31053912

RESUMEN

The yeast Saccharomyces cerevisiae has been widely used as a model system for studying the physiological and pharmacological action of small-molecular drugs. Here, a heterozygous diploid S. cerevisiae strain QSS4 was generated to determine whether drugs could induce chromosomal instability by determining the frequency of mitotic recombination. Using the combination of a custom SNP microarray and yeast screening system, the patterns of chromosomal instability induced by drugs were explored at the whole genome level in QSS4. We found that Zeocin (a member of the bleomycin family) treatment increased the rate of genomic alterations, including aneuploidy, loss of heterozygosity (LOH), and chromosomal rearrangement over a hundred-fold. Most recombination events are likely to be initiated by DNA double-stand breaks directly generated by Zeocin. Another remarkable finding is that G4-motifs and low GC regions were significantly underrepresented within the gene conversion tracts of Zeocin-induced LOH events, indicating that certain DNA regions are less preferred Zeocin-binding sites in vivo. This study provides a novel paradigm for evaluating genetic toxicity of small-molecular drugs using yeast models.


Asunto(s)
Inestabilidad Cromosómica/efectos de los fármacos , Cromosomas Fúngicos , Saccharomyces cerevisiae/efectos de los fármacos , Saccharomyces cerevisiae/genética , Bibliotecas de Moléculas Pequeñas/farmacología , Aneuploidia , Bleomicina/farmacología , División Celular , Reordenamiento Génico , Inestabilidad Genómica , Pérdida de Heterocigocidad , Recombinación Genética
8.
Curr Microbiol ; 76(3): 297-303, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30603961

RESUMEN

A novel bacterial strain A7.6T was isolated from the sediments collected near the Zhairuo Island located in the East China Sea and characterized using a polyphasic approach. Cells were Gram-stain-negative, rod-shaped, non-spore forming, non-flagellated but motile by gliding. The strain was aerobic, positive for oxidase and catalase activities. The strain can grow at 4-35 °C, pH 5.5-9.0, and 0-3% (w/v) NaCl concentration. The major polar lipid was phosphatidylethanolamine, the predominant fatty acids (> 10%) were iso-C15:0 and summed feature 3 (C16:1 ω7c and/or C16:1 ω6c). The genomic G+C content was 33.6 mol% and the major respiratory quinone was menaquinone 6. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain A7.6T belonged to the genus Flavobacterium and was closely related to Flavobacterium tistrianum GB 56.1T (98.4% similarity), F. nitrogenifigens NXU-44T (98.4%), F. ginsenosidimutans THG 01T (98.0%) and F. anhuiense D3T (97.7%). Average nucleotide identities and digital DNA-DNA hybridizations values for genomes ranged from 75.9 to 91.4% and 21.4 to 43.9% between strain A7.6T and its closest phylogenetic neighbors. The polyphasic characterization indicated that strain A7.6T represented a novel species of the genus Flavobacterium, for which the name Flavobacterium sharifuzzamanii is proposed. The type strain is A7.6T (= KCTC 62405T = MCCC 1K03485T). The NCBI GenBank accession number for the 16S rRNA gene of A7.6T is MH396692, and for the genome sequence is QJGZ00000000. The digital protologue database (DPD) Taxon Number is TA00643.


Asunto(s)
Flavobacterium/clasificación , Flavobacterium/fisiología , Sedimentos Geológicos/microbiología , Océanos y Mares , Filogenia , Composición de Base , China , ADN Bacteriano/genética , Ácidos Grasos/análisis , Flavobacterium/química , Genoma Bacteriano/genética , Concentración de Iones de Hidrógeno , Fosfolípidos/análisis , Quinonas/análisis , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Cloruro de Sodio , Temperatura
9.
J Zhejiang Univ Sci B ; 17(6): 447-54, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27256678

RESUMEN

Elsholtzia splendens (Lamiaceae) is a copper-tolerant plant species growing on copper deposits in the south of China. Chromatographic separation of n-BuOH extracts from the flowering aerial biomass afforded apigenin-7-O-ß-D-glycoside, using macroporous resin, Sephadex™ LH-20 gel, polyamide resin as well as preparative high-performance liquid chromatography (P-HPLC) columns. Chemical structure was elucidated using HPLC/ESI-MS (electrospray ionization-mass spectrometry), Fourier transform infrared (FTIR), and (1)D- and (2)D-nuclear magnetic resonance (NMR). Apigenin-7-O-ß-D-glycoside could be the post-harvesting product from E. splendens biomass.


Asunto(s)
Apigenina/aislamiento & purificación , Cobre/farmacología , Glicósidos/aislamiento & purificación , Lamiaceae/química , Apigenina/química , Glicósidos/química , Espectroscopía de Resonancia Magnética , Espectroscopía Infrarroja por Transformada de Fourier
10.
Evol Bioinform Online ; 12(Suppl 1): 1-4, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27081303

RESUMEN

Aspergillus sp. Z5, isolated from the gut of marine isopods, produces prolific secondary metabolites with new structure and bioactivity. Here, we report the draft sequence of the approximately 33.8-Mbp genome of this strain. To the best of our knowledge, this is the first genome sequence of Aspergillus strain isolated from marine isopod Ligia oceanica. The phylogenetic analysis supported that this strain was closely related to A. versicolor, and genomic analysis revealed that Aspergillus sp. Z5 shared a high degree of colinearity with the genome of A. sydowii. Our results may facilitate studies on discovering the biosynthetic pathways of secondary metabolites and elucidating their evolution in this species.

11.
AMIA Annu Symp Proc ; 2011: 1355-60, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-22195197

RESUMEN

The American Board of Family Medicine (ABFM) has used a 60-item Multiple Choice Question (MCQ) section followed by a Virtual Patient (VP) exercise in Maintenance Of Certification (MOC) since 2004, and has had an asthma module since 2005. The original asthma VP criteria anticipated some Expert Panel Report-3 recommendations, such as home peak flow monitoring and a written plan, that were added to the MCQ section only when the guideline was updated in 2007. VP completion rates for these criteria improved markedly with the MCQ update, while other criteria completion rates were stable. Asthma criteria completion rates are not predicted by the strength of evidence for the criteria. User interface details influence criteria completion rates, but did not affect the changes observed in 2007. Asthma MCQ content affects Diplomate performance on asthma VP: this translational step suggests that MOC exercises could result in improved care for real patients.


Asunto(s)
Asma , Educación Médica Continua/métodos , Simulación de Paciente , Médicos de Familia , Consejos de Especialidades , Certificación , Evaluación Educacional/métodos , Medicina Familiar y Comunitaria/educación , Humanos , Estados Unidos
12.
Anal Bioanal Chem ; 395(7): 2359-70, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19784638

RESUMEN

A confirmatory and quantitative method based on liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI/MS/MS) has been developed for simultaneous determination of seven photoinitiator residues: benzophenone, (1-hydroxycyclohexyl)phenylketone (Irgacure 184), isopropylthioxanthone (ITX), 2-ethylhexyl-(4-dimethylamino)benzoate (EHA or EHDAB), 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone (Irgacure 907), (2,4,6-trimethylbenzoyl)diphenylphosphine oxide (TPO) and 2-benzyl-2-(dimethylamino)-1-(4-morpholinophenyl)-1-butanone (Irgacure 369) in packaged milk and related packaging materials. Residues of photoinitiators were extracted from milk using acetonitrile, and further enriched and purified on HLB solid-phase extraction cartridges prior to being analyzed by LC-ESI/MS/MS with selected reaction monitoring mode, while photoinitiators in packaging materials were extracted using the same solvent. Satisfactory recovery (from 80 to 111%), intra- and inter-day precision (below 12%), and low limits of quantification (from 0.1 to 5.0 microg kg(-1)) were evaluated from spiked samples at three concentration levels (5.0, 10.0 and 25.0 microg kg(-1) for Irgacure 184 and 2.5, 5.0 and 25.0 microg kg(-1) for others). These excellent validation data suggested the possibility of using the LC-ESI/MS/MS method for simultaneous determination of low-level photoinitiator residues migrating from printed food-packaging materials into milk. The method has been successfully applied to the analysis of real samples of different fat contents ranging from 8 to 30 g L(-1). The photoinitiator residues were revealed to be higher in milk with higher fat content and the most important contaminations were benzophenone and ITX in concentration ranges of 2.84-18.35 and 0.83-8.87 microg kg(-1), respectively.

13.
J Chromatogr B Analyt Technol Biomed Life Sci ; 877(29): 3522-8, 2009 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-19748327

RESUMEN

A simple and reliable method to detect seven microcystins in hard clam and corbicula fluminea, based on liquid chromatography with electrospray ionization and tandem mass spectrometry (LC-ESI-MS/MS), was developed and validated. The sample preparation procedure includes extraction of tissue by methanol, followed by cleanup on a reversed-phase solid phase extraction (SPE) cartridge. With the optimized method, recoveries were between 43.7% and 92.3% for hard clam, 54.3% and 93.8% for corbicula fluminea, the relative standard deviations (RSD) were less than or equal to 16.2% and 15.7% in hard clam and corbicula fluminea at spiking levels of 1 microg/kg, 2 microg/kg and 5 microg/kg for MC-RR, MC-YR, MC-LR, and MC-LY, and 2 microg/kg, 5 microg/kg and 10 microg/kg for MC-LA, MC-LW and MC-LF, respectively, the limits of quantitation (LOQ) of this method were ranged from 0.7 microg/kg to 2.0 microg/kg.


Asunto(s)
Bivalvos/metabolismo , Cromatografía Liquida/métodos , Corbicula/metabolismo , Microcistinas/análisis , Espectrometría de Masas en Tándem/métodos , Animales , Microcistinas/química , Reproducibilidad de los Resultados
14.
J Sep Sci ; 32(23-24): 4020-4, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-20066677

RESUMEN

A method for the determination and confirmation of amitraz and its degradation product 2,4-dimethylaniline (2,4-DMA) in honey is reported. Determination of the two compounds was based on HPLC with UV detection and MS/MS (LC-MS/MS) after a liquid-liquid extraction with hexane and isopropyl alcohol. Chromatographic separation was achieved by using a C18 column with a gradient mobile phase consisting of 0.02 M ammonium acetate and ACN. Recoveries for fortified honey ranged from 83.4 to 103.4% for amitraz and from 89.2 to 104.7% for 2,4-DMA with RSD values lower than 11.6% for HPLC and LC-MS/MS methods. LOD was 6 microg/kg for amitraz and 8 microg/kg for 2,4-DMA, while LOQ was 20 microg/kg for amitraz and 25 microg/kg for 2,4-DMA in HPLC method. LOD was 1 microg/kg for amitraz and 2 microg/kg for 2,4-DMA, while LOQ was 5 microg/kg for amitraz and 10 microg/kg for 2,4-DMA in LC-MS/MS method.


Asunto(s)
Compuestos de Anilina/análisis , Cromatografía Liquida/métodos , Contaminación de Alimentos/análisis , Miel/análisis , Espectrometría de Masas en Tándem/métodos , Toluidinas/análisis , Acaricidas/análisis , Cromatografía Líquida de Alta Presión/métodos , Residuos de Plaguicidas/análisis , Espectrometría de Masa por Ionización de Electrospray/métodos
15.
J Sep Sci ; 32(23-24): 4193-9, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-20066681

RESUMEN

A method for the determination and confirmation of methylene blue (MB) in aquatic products was developed. Residues of MB were extracted from homogenized tissues with acetonitrile/sodium acetate buffer solution, and simply cleaned up with dichloromethane liquid/liquid extraction. After concentration and dissolution, the sample solutions were cleaned up by the neutral alumina and weak cation-exchange solid phase extraction (SPE) cartridge, prior to LC-MS/MS analysis. MB was determined at 1.0-20 microg/kg in eel, toasted eel and shrimp, with a limit of quantification of 0.5 microg/kg. Recovery for MB was between 73.0% and 108.3%. This method is fast, exact and sensitive. It can be applied to determine MB in aquatic products.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Azul de Metileno/análisis , Espectrometría de Masas en Tándem/métodos , Contaminantes Químicos del Agua/análisis , Animales , Antifúngicos/análisis , Acuicultura , Residuos de Medicamentos/análisis , Anguilas , Concentración Máxima Admisible , Penaeidae , Extracción en Fase Sólida
16.
J Zhejiang Univ Sci B ; 9(9): 728-33, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18763306

RESUMEN

A high-performance liquid chromatographic (HPLC) method with ultraviolet (UV) detector had been developed for simultaneous quantification of danshensu, protocatechuic aldehyde, caffeic acid, salvianolic acid D, rosmarinic acid, salvianolic acid B and salvianolic acid A in Danshen injection. According to the UV spectra of these components, three detection wavelengths have been selected as follows: 280 nm for danshensu and protocatechuic aldehyde, 326 nm for caffeic acid, salvianolic acid D and rosmarinic acid, 286 nm for salvianolic acid B and salvianolic acid A. The limit of detection (LOD) was improved to be in the range of 0.008-0.160 microg/ml. Moreover, excellent linear behavior over the investigated concentration range was observed, with R>0.999 for all the analytes.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Medicamentos Herbarios Chinos/química , Hidroxibenzoatos/química , Salvia miltiorrhiza/química , Espectrofotometría Ultravioleta/métodos , Evaluación Preclínica de Medicamentos
17.
Artículo en Inglés | MEDLINE | ID: mdl-18485838

RESUMEN

A confirmatory method coupling liquid chromatography with tandem mass spectrometry (LC/MS/MS) was developed to determine the concentration of oxytetracycline (OTC), tetracycline (TC), chlortetracycline (CTC) and doxycycline (DC), which make up the tetracycline (TC) groups present in royal jelly. Sample preparation included deproteination, control of pH, extraction and clean-up on a solid-phase extraction (SPE) cartridge. The analyses were achieved by LC/MS/MS in selected reaction monitoring mode (SRM). The overall recovery of fortified royal jelly at the levels of 5.0, 10.0 and 40.0 microg/kg ranged from 62% to 115%, and the coefficients of variation ranged from 3.4% to 16.3% (n=6). The detection limits for TCs were under 1.0 microg/kg. The transformation between the TCs and its epimers (EpiTCs) was studied in standard solution and during the sample preparation process. This method can be used for the detection of tetracycline residues in royal jelly.


Asunto(s)
Antibacterianos/análisis , Cromatografía Liquida/métodos , Residuos de Medicamentos/análisis , Ácidos Grasos/química , Espectrometría de Masa por Ionización de Electrospray/métodos , Espectrometría de Masas en Tándem/métodos , Tetraciclina/análisis , Calibración , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
18.
Talanta ; 71(2): 550-4, 2007 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-19071339

RESUMEN

Direct electrochemical and electrocatalytic behavior of hemoglobin (Hb) immobilized on glass carbon electrode (GCE) containing gelatine (Gel) films was investigated. The characteristics of Hb/Gel film modified GC electrode were performed by using SEM microscopy, UV-vis spectroscopy and electrochemical methods. The immobilized Hb showed a couple of quasi-reversible redox peak with a formal potential of -0.38V (versus SCE) in 0.1M pH 7.0 PBS. The formal potential changed linearly from pH 4.03 to 8.41 with a slope value of -52.0mV pH(-1), which suggested that a proton transfer was accompanied with each electron transfer (ET) in the electrochemical reaction. The Hb/gelatine/GCE displayed a rapid amperometric response to the reduction of H(2)O(2) and nitrite.

19.
AMIA Annu Symp Proc ; : 706-10, 2007 Oct 11.
Artículo en Inglés | MEDLINE | ID: mdl-18693928

RESUMEN

The American Board of Family Medicine deployed virtual patient simulations in 2004 to evaluate Diplomates' diagnostic and management skills. A previously reported dynamic process generates general symptom histories from time series data representing baseline values and reactions to medications. The simulator also must answer queries about details such as palliation and provocation. These responses often describe some recurring pattern, such as, "this medicine relieves my symptoms in a few minutes." The simulator can provide a detail stored as text, or it can evaluate a reference to a second query object. The second query object can generate details using a single Bayesian network to evaluate the effect of each drug in a virtual patient's medication list. A new medication option may not require redesign of the second query object if its implementation is consistent with related drugs. We expect this mechanism to maintain realistic responses to detail questions in complex simulations.


Asunto(s)
Simulación por Computador , Quimioterapia , Redes Neurales de la Computación , Cuidados Paliativos , Simulación de Paciente , Algoritmos , Angina de Pecho/tratamiento farmacológico , Teorema de Bayes , Competencia Clínica , Evaluación Educacional/métodos , Medicina Familiar y Comunitaria/normas , Humanos
20.
J AOAC Int ; 89(5): 1432-6, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-17042196

RESUMEN

A liquid chromatographic/tandem mass spectrometric method was developed and validated for the determination of chloramphenicol (CAP) in royal jelly. Royal jelly samples were first denatured with lead acetate solution, and the CAP was extracted with solid-phase extraction before separation by liquid chromatography. A triple-quadrupole mass spectrometer operated in the negative electrospray ionization and selected-reaction monitoring mode was used for the detection of CAP. For method validation, royal jelly samples were fortified at CAP levels between 0.1 and 10.0 microg/kg; at these levels, recovery values (internal standard-corrected) ranged from 93.3 to 105.0%, and the within-laboratory reproducibility (relative standard deviation) was < or = 9.1%. The decision limit was 0.07 microg/kg, and the detection capability was 0.1 microg/kg.


Asunto(s)
Antibacterianos/análisis , Cloranfenicol/análisis , Cromatografía Liquida/métodos , Ácidos Grasos/análisis , Análisis de los Alimentos/métodos , Contaminación de Alimentos/análisis , Espectrometría de Masa por Ionización de Electrospray/métodos , Antibacterianos/normas , Cloranfenicol/normas , Cromatografía Liquida/normas , Cromatografía Liquida/estadística & datos numéricos , Ácidos Grasos/normas , Análisis de los Alimentos/normas , Análisis de los Alimentos/estadística & datos numéricos , Contaminación de Alimentos/estadística & datos numéricos , Estándares de Referencia , Reproducibilidad de los Resultados , Espectrometría de Masa por Ionización de Electrospray/normas , Espectrometría de Masa por Ionización de Electrospray/estadística & datos numéricos
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