• chemical sciences close

In this work, we present a method to isolate mitochondria of mammalian cells after cell disruption on microscale. The device is composed of linear microchannels cast in PDMS (polydimethylsiloxane). Specific antibodies against the translocase outer membrane protein of the mitochondria are immobilized on the surface of the substrate using an avidin-biotin sandwich construct. The mitochondria can be captured in the channel, whereas the remains of the cell lysate flow out the chip unhindered. The captured mitochondria can be observed directly on chip. A successful immobilization of pre-isolated mitochondria was shown at a flow rate between 0 and 5 μl min-1 (≈0-2.5 mm s -1). After fluorescence staining, we demonstrated that the mitochondria covered around 3% of the channel surface. The mitochondria appeared in a distinct spherical shape with a diameter of around 0.8-1.2 μm. Further validation of the microfluidic device using non-treated cell lysate was done at 2 μl min-1. The immobilized mitochondria were smaller with a diameter of around ≈490 nm. We observed a surface coverage of around 4%. The immobilized mitochondria were active and stable for over 2 h without cooling and were shown to be able to produce ATP under stage 3 respiration on chip. © 2013 The Royal Society of Chemistry.

Los Turbocombustibles tradicionalmente son analizados bajo metodologías estándar definidas por la American Society for Testing and Materials (ASTM), los cuales requieren de personal preparado, infraestructura, equipos especializados y con frecuencia más tiempo del requerido para realizar un control de procesos al instante para la toma de decisiones y ajustes en planta. Los avances en técnicas computacionales usadas en la Quimiometría han hecho de esta una valiosa herramienta que complementa a la química analítica convencional debido a su precisión y rapidez para arrojar resultados confiables. En ese sentido, se realizó una investigación del estado del arte en la aplicación de análisis quimiométrico a la predicción de propiedades del Turbocombustible, empleando bases de datos y páginas de internet oficiales. Entre las más estudiadas se encuentra la curva de destilación, la gravedad API, densidad, el punto de inflamación, el punto de congelación, viscosidad y contenido de aromáticos. Las técnicas más utilizadas para la elaboración de los modelos de predicción son las de espectroscopía Infrarroja, aunque también se ha usado la RAMAN y la cromatografía de Gases. Al sintetizar y analizar los métodos resultantes de la investigación bibliográfica se determinó que los mejores resultados en términos de calidad de la predicción se obtuvieron usando FTIR y PLS como método de correlación. Jet fuel is traditionally analyzed under standards defined by the American Society for Testing and Materials (ASTM), which requires trained personal, infrastructure, specialized equipment and much more time than the one allowed to have industrial processes under control and plant adjustments . The advances in computational techniques applied in chemometrics have turned it into a valuable tool that complements conventional analytical chemistry due to its precision and ability to give fast reliable results. Under that frame this research on the state of the art of chemometrics applied in the prediction of jet fuel properties was done on official databases and web pages. The most studied properties are the distillation curve, API gravity, density, flash point, freeze point, viscosity and aromatic content. The majority of researches done so far include spectroscopic techniques such as infrared to elaborate the prediction models, although RAMAN and gas chromatography are also found. After summarizing and analyzing all de data from the research, it was determined that the best results are obtained using FTIR as spectra’s source along with PLS as correlation method.

Abstract A feasibility study of flow injection/mass spectrometry is described. Flow-injection systems can be used either for direct introduction of an analyte to the mass spectrometer, or to convert the analyte to a suitable form for detection. This ability, along with the members separation, provides enhanced selectivity and scope. The selectivity and sensitivity inherent in mass spectrometry serve to increase the utility of flow-injection methods. Determination of arsenic and chloroform are discussed.

The first report on Ir(iii)-catalyzed C–H alkylation/cyclization of azobenzene with diazotized Meldrum's acid was developed for the synthesis of cinnoline-3(2H)-one-4-carboxylic acid and its ester derivative under mild conditions.

In recent years, molecularly imprinted polymers (MIPs) have become an excellent solution to the selective and sensitive determination of target molecules in complex matrices where other similar and relative structural compounds could coexist. Although MIPs show the inherent properties of the polymers, including stability, robustness, and easy/cheap synthesis, some of their characteristics can be enhanced, or new functionalities can be obtained when nanoparticles are incorporated in their polymeric structure. The great variety of nanoparticles available significantly increase the possibility of finding the adequate design of nanostructured MIP for each analytical problem. Moreover, different structures (i.e., monolithic solids or MIPs micro/nanoparticles) can be produced depending on the used synthesis approach. This review aims to summarize and describe the most recent and innovative strategies since 2015, based on the combination of MIPs with nanoparticles. The role of the nanoparticles in the polymerization, as well as in the imprinting and adsorption efficiency, is also discussed through the review.

Este estudio tuvo como objetivo comparar las actividades fenólicas totales (TPC), flavonoides (TFc), eliminadores de radicales y citotóxicas en los extractos metanólicos acuosos de Angelica sinensis, Dioscorea polystachya, Ginkgo biloba, Glycyrrhiza uralensis y Lycium barbarum con dos plantas dietéticas: Brassica oleracea y Zingiber officinale. La TPC y TFc en extractos de plantas medicinales fueron 12-93% más bajas que Z. officinale de la siguiente manera: L. barbarum > G. uralensis > A. sinensis > G. biloba > D. polystachya. La disminución de la actividad de eliminación de radicales en extractos de plantas medicinales compartió una tendencia similar: G. uralensis > L. barbarum > A. sinensis > G. biloba > D. polystachya. Tanto la TPC como la TFc se correlacionaron positivamente con la eliminación de radicales y las actividades citotóxicas. Todas las plantas medicinales se consideraron inactivas (CL50 > 0,2 mg/ml) y seguras para el consumo. Las actividades de TPC, TFc, eliminación de radicales y citotóxicas en las plantas medicinales fueron dependientes de la parte de la planta, en particular L. barbarum y G. uralensis. Cette étude visait à comparer les activités phénolique totale (TPC), flavonoïde (TFC), anti-radicalaire et cytotoxique dans les extraits méthanoliques aqueux d'Angelica sinensis, Dioscorea polystachya, Ginkgo biloba, Glycyrrhiza uralensis et Lycium barbarum avec deux plantes alimentaires : Brassica oleracea et Zingiber officinale. Le TPC et le TFC dans les extraits de plantes médicinales étaient de 12 à 93% inférieurs à Z. officinale comme suit : L. barbarum > G. uralensis > A. sinensis > G. biloba > D. polystachya. L'activité décroissante de piégeage des radicaux dans les extraits de plantes médicinales partage une tendance similaire : G. uralensis > L. barbarum > A. sinensis > G. biloba > D. polystachya. Le TPC et le TFC étaient en corrélation positive avec les activités de piégeage des radicaux et les activités cytotoxiques. Toutes les plantes médicinales ont été considérées comme inactives (CL50 > 0,2 mg/ml) et sans danger pour la consommation. Les activités TPC, TFC, anti-radicaux et cytotoxiques dans les plantes médicinales étaient dépendantes des parties végétales, en particulier L. barbarum et G. uralensis. This study aimed to compare the total phenolic (TPC), flavonoid (TFC), radical scavenging and cytotoxic activities in the aqueous methanolic extracts of Angelica sinensis, Dioscorea polystachya, Ginkgo biloba, Glycyrrhiza uralensis and Lycium barbarum with two dietary plants: Brassica oleracea and Zingiber officinale. The TPC and TFC in medicinal plant extracts were 12-93% lower than Z. officinale as follows: L. barbarum > G. uralensis > A. sinensis > G. biloba > D. polystachya. The decreasing radical scavenging activity in medicinal plant extracts shared similar trend: G. uralensis > L. barbarum > A. sinensis > G. biloba > D. polystachya. Both TPC and TFC were positively correlated with radical scavenging and cytotoxic activities. All medicinal plants were considered inactive (LC50 > 0.2 mg/ml) and safe for consumption. The TPC, TFC, radical scavenging and cytotoxic activities in the medicinal plants were plant-part dependant, in particular L. barbarum and G. uralensis. هدفت هذه الدراسة إلى مقارنة إجمالي الأنشطة الفينولية (TPC) والفلافونويد (TFC) والكسح الجذري والأنشطة السامة للخلايا في المستخلصات الميثانولية المائية من أنجليكا سينينسيس، وديوسكوريا بوليستاشيا، وجينكو بيلوبا، وجليسيريزا uralensis و Lycium barbarum مع نباتين غذائيين: Brassica oleracea و Zingiber officinale. كانت TPC و TFC في المستخلصات النباتية الطبية أقل بنسبة 12-93 ٪ من Z. officinale على النحو التالي: L. barbarum > G. uralensis > A. sinensis > G. biloba > D. polystachya. يشترك نشاط الكسح الجذري المتناقص في المستخلصات النباتية الطبية في اتجاه مماثل: G. uralensis > L. barbarum > A. sinensis > G. biloba > D. polystachya. ارتبط كل من TPC و TFC ارتباطًا إيجابيًا بأنشطة الكسح الجذري والسمية الخلوية. تم اعتبار جميع النباتات الطبية غير نشطة (التركيز المميت للنصف أكبر من 0.2 ملجم/مل) وآمنة للاستهلاك. كانت TPC و TFC وأنشطة الكسح الجذري والسمية الخلوية في النباتات الطبية معتمدة على النبات، ولا سيما L. barbarum و G. uralensis.

Abstract A process for the separation of enantiomers by TLC is described. Reversed-phase plates, pre-treated with a copper II complex of N,N-di-n-propyl-L-alanine separate all the dansyl protein amino acids, except proline, each to its D and L enantiomers.