Fluorescence spectroscopy and its applications: A Review

Fluorescence spectroscopy is a rapid, sensitive method for characterizing molecular environments and events samples. Fluorimetry is chosen for its extraordinary sensitivity, high specificity, simplicity and low cost as compared to other analytical techniques. It is widely accepted and powerful technique that is used for a variety of environmental, industrial, medical diagnostics, DNA sequencing, forensics, genetic analysis and biotechnology applications. It is a valuable analytical tool for both quantitative and qualitative analysis. This article presents a brief overview of the theory of fluorescence spectroscopy, together with examples of applications of this technique in organic and inorganic chemistry, medical diagnosis, medical science etc

Geology and spatial distribution of uranium mineralisation in the SK anomaly area, Rossing area, Namibia

The nature, geology and spatial distribution of uranium minerals in the SK anomaly area, Rössing Uranium Mine, Namibia, is investigated to perceive if the mineralogy is favourable for uranium extraction using sulphuric acid plant. In addition to the SK anomaly area, the Rössing Uranium Mine area has two other uranium-rich areas, the SH and SJ anomalies. At present only the SJ anomaly area is being mined due to its favourable mineralogy of 55% uraninite, 40% secondary minerals and 5% betafite. The SK anomaly is made up of about 32 sub-anomalies, of which SK4 is part off. Geological mapping, radiation survey analyses, petrographic analyses, 3-D modelling, SEM, QEMSCAN, uranium budget and geochemical analyses have been carried out with the aim to understand the area’s geology, outline the high priority exploration targets within the SK anomaly, spatial distribution, and proportions of the primary, secondary and refractory uranium bearing minerals in the SK area. Of the different six leucogranites observed by Nex (1997) in the Goanikontes area; only four types (B to E) are found in the SK area. Betafite is associated with type D leucogranite, although traces are present in type E leucogranite. Betafite ((U,Ca)(Ti,Ta,Nb)3O9) is a Ti-rich member of the pyrochlore group and does not readily release uranium with acid, even in an oxidized state. Currently betafite cannot be leached at atmospheric pressure with sulphuric leach. Due to its high abundance in SH area, if SK area has high betafite, Rössing Uranium Mine has to come with another approach to leach the uranium out of betafite. The SJ area contains sheeted leucogranites emplaced into the Rössing Formation calc-silicates and the meta-pelitic sediments of the Khan Formation. The same geological setting is also observed in the SK area. The Rössing and Khan lithological units seem to increase in thickness from the SJ to the SK area. The bedding/foliation relationship and the relative ages of the lithological units indicate that the SK area is an anticline; while the SK4 area is a syncline. In the SK anticline, where the marble unit tripled in thickness from the SJ pit, there is 65% betafite, 8% uraninite and 27% secondary uranium bearing minerals. The SK4 area is a minor syncline within the major SK anticline area; has 5% betafite, 64% uraninite and 31% secondary uranium bearing minerals. This study concludes that there is a structural and lithological control on betafite formation in the SK anticline and SK4 areas. If the current acid plant is used to process material from the SK anticline area, recoveries will be low as most of the uranium is hosted in betafite form. In fact only U-silicates and uraninite will be leached successfully. Considering the fact that the SH area also has a high betafite content, Rössing Uranium Mine may have to find ways to leach the uranium from betafite, to make SH and SK areas feasible for mining

Molecular dosimetry of 1,2 guanine-guanine intrastrand cross links of cisplatin by ultra performance liquid chromatography tandem mass spectrometry

Cisplatin has been extensively studied as an antitumor agent since the late 1960s. However the mode of action for the efficacy and adverse effects of cisplatin are poorly understood. It was previously believed that the cisplatin1,2 intrastrand guanine-guanine [CP-d(GpG)] cross link was likely responsible for much of the cytotoxic actions of the compound. But current techniques prevented accurate and specific adduct quantification using pharmacologically relevant concentrations of cisplatin. Therefore, the development of a highly sensitive and specific method to measure the CPd( GpG) cross link was begun. Using this technique, this dissertation aimed to study the role of CP-d(GpG) in acquired resistance and different genetic profiles. The developed mass spectrometry method is able to measure 3.7 adducts per 108 nucleotides using 25 μg of DNA per injection. Preliminary results indicated that the method was sensitive enough to quantify adducts in ovarian carcinoma cells using as little as 12.5 μM cisplatin. It was also able to quantify adducts the kidney, liver and colon tissues of mice that had been iii given 7 mg/kg cisplatin by i.p. injection. Our hypothesis was that the density of CP-d(GpG) cross links would serve as a useful biomarker for efficacy and/or toxicity of cisplatin. Research was conducted to understand CPd( GpG) formation in ovarian carcinoma cell lines as well as in 8 inbred strains of mice. Results indicate that the dose response relationship for adduct formation in our isogenic cisplatin sensitive and resistant cell lines remains linear, when using lower more pharmacologically relevant doses of cisplatin. In mice, adducts were most concentrated in the kidney. Of the 8 inbred strains tested the C57BL/6J mice were the most sensitive and FVB/NJ least sensitive to cisplatin treatment. Toxicity, as determined by histopathology, did not correlate with CP-d(GpG) molecular dosimetry. However, this lack of correlation may be due to the design of the mouse study, as such many suggestions for future animal studies are given. Based on reported concentrations of platinum DNA adducts clinical samples, the sensitivity and specificity of our method could provide additional insight as to the role of CPd( GpG) adduct formation in cancer patients being treated with cisplatin

Inulin from Jerusalem artichoke (Helianthus tuberosus L.): From its biosynthesis to its application as bioactive ingredient

Jerusalem artichoke (Helianthus tuberosus L.) represents a promising crop emerging in different parts of the world as a natural source of inulin. Different factors such as the kind of cultivar, agroecological conditions, harvest time, and tubers storage, have an impact on the inulin content and the physicochemical and biological characteristics. A wide variety of protocols for the extraction of inulin from Jerusalem artichoke tubers have been described that should be applied and selected considering the desired purity, the equipment available, and the environmental impact. The biosynthesis of the inulin during the plant life cycle, the beneficial health effects of Jerusalem artichoke tubers as well as the application of inulin as a bioactive ingredient in functional foods, are presented in this review. The data analyzed revealed that information is missing about the physicochemical characteristics of the inulin used in the different studies. Finally, the reviewed information contributes to the knowledge of the use of this compound as an ingredient in the food industry considering both its technological and bioactive effects.Fil: Rubel, Irene Albertina. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Tecnología de los Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Iraporda, Carolina. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Tecnología de los Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Manrique, Guillermo Daniel. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Tecnología de los Alimentos; ArgentinaFil: Genovese, Diego Bautista. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Planta Piloto de Ingeniería Química (I). Grupo Vinculado al Plapiqui - Investigación y Desarrollo en Tecnología Química; ArgentinaFil: Abraham, Analia Graciela. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentin

Implementación de buenas prácticas de manufactura en pequeñas queserías de Tandil: construyendo calidad desde el enfoque peligro-riesgo

El partido de Tandil cuenta con una larga trayectoria en la producción láctea y elaboración de quesos. En un trabajo previo junto con la Universidad Nacional del Centro de la Provincia de Buenos, "Programa Institucional de Alimentos, Proyecto: Alimentos con Identidad Territorial: Construcción Participativa de los quesos típicos de Tandil" (2010) se detectaron unas 15 queserías (cerca de un75% del total de queserías de Tandil), y cuyas realidades son muy diversas evidenciadas en distintos niveles de producción (los volúmenes de leche que utilizan los productores para la elaboración de quesos van desde los 50 hasta los 7000 litros aproximadamente, con excepción de uno de ellos que utiliza 34000 litros), estado de las instalaciones, formas de comercialización y capital con el que cuentan. Se realizaron observaciones de los procesos de elaboración de las queserías en dos períodos: otoño y primavera de 2010, identificando los puntos críticos a controlar más relevantes, describiendo no sólo el proceso de elaboración sino también las condiciones edilicias del lugar donde elaboran. Se tomaron muestras de agua, leche y quesos para realizarles los análisis de calidad correspondientes.Territorios y estrategias de intervención.Universidad Nacional de La Plat

Implementación de buenas prácticas de manufactura en pequeñas queserías de Tandil: construyendo calidad desde el enfoque peligro-riesgo

El partido de Tandil cuenta con una larga trayectoria en la producción láctea y elaboración de quesos. En un trabajo previo junto con la Universidad Nacional del Centro de la Provincia de Buenos, "Programa Institucional de Alimentos, Proyecto: Alimentos con Identidad Territorial: Construcción Participativa de los quesos típicos de Tandil" (2010) se detectaron unas 15 queserías (cerca de un75% del total de queserías de Tandil), y cuyas realidades son muy diversas evidenciadas en distintos niveles de producción (los volúmenes de leche que utilizan los productores para la elaboración de quesos van desde los 50 hasta los 7000 litros aproximadamente, con excepción de uno de ellos que utiliza 34000 litros), estado de las instalaciones, formas de comercialización y capital con el que cuentan. Se realizaron observaciones de los procesos de elaboración de las queserías en dos períodos: otoño y primavera de 2010, identificando los puntos críticos a controlar más relevantes, describiendo no sólo el proceso de elaboración sino también las condiciones edilicias del lugar donde elaboran. Se tomaron muestras de agua, leche y quesos para realizarles los análisis de calidad correspondientes.Territorios y estrategias de intervención.Universidad Nacional de La Plat

Implementación de buenas prácticas de manufactura en pequeñas queserías de Tandil: construyendo calidad desde el enfoque peligro-riesgo

El partido de Tandil cuenta con una larga trayectoria en la producción láctea y elaboración de quesos. En un trabajo previo junto con la Universidad Nacional del Centro de la Provincia de Buenos, "Programa Institucional de Alimentos, Proyecto: Alimentos con Identidad Territorial: Construcción Participativa de los quesos típicos de Tandil" (2010) se detectaron unas 15 queserías (cerca de un75% del total de queserías de Tandil), y cuyas realidades son muy diversas evidenciadas en distintos niveles de producción (los volúmenes de leche que utilizan los productores para la elaboración de quesos van desde los 50 hasta los 7000 litros aproximadamente, con excepción de uno de ellos que utiliza 34000 litros), estado de las instalaciones, formas de comercialización y capital con el que cuentan. Se realizaron observaciones de los procesos de elaboración de las queserías en dos períodos: otoño y primavera de 2010, identificando los puntos críticos a controlar más relevantes, describiendo no sólo el proceso de elaboración sino también las condiciones edilicias del lugar donde elaboran. Se tomaron muestras de agua, leche y quesos para realizarles los análisis de calidad correspondientes.Territorios y estrategias de intervención.Universidad Nacional de La Plat

A reversibly gated protein-transporting membrane channel made of DNA

Controlled transport of biomolecules across lipid bilayer membranes is of profound significance in biological processes. In cells, cargo exchange is mediated by dedicated channels that respond to triggers, undergo a nanomechanical change to reversibly open, and thus regulate cargo flux. Replicating these processes with simple yet programmable chemical means is of fundamental scientific interest. Artificial systems that go beyond nature's remit in transport control and cargo are also of considerable interest for biotechnological applications but challenging to build. Here, we describe a synthetic channel that allows precisely timed, stimulus-controlled transport of folded and functional proteins across bilayer membranes. The channel is made via DNA nanotechnology design principles and features a 416 nm2 opening cross-section and a nanomechanical lid which can be controllably closed and re-opened via a lock-and-key mechanism. We envision that the functional DNA device may be used in highly sensitive biosensing, drug delivery of proteins, and the creation of artificial cell networks

MRF4 negatively regulates adult skeletal muscle growth by repressing MEF2 activity

The myogenic regulatory factor MRF4 is highly expressed in adult skeletal muscle but its function is unknown. Here we show that Mrf4 knockdown in adult muscle induces hypertrophy and prevents denervation-induced atrophy. This effect is accompanied by increased protein synthesis and widespread activation of muscle-specific genes, many of which are targets of MEF2 transcription factors. MEF2-dependent genes represent the top-ranking gene set enriched after Mrf4 RNAi and a MEF2 reporter is inhibited by co-transfected MRF4 and activated by Mrf4 RNAi. The Mrf4 RNAi-dependent increase in fibre size is prevented by dominant negative MEF2, while constitutively active MEF2 is able to induce myofibre hypertrophy. The nuclear localization of the MEF2 corepressor HDAC4 is impaired by Mrf4 knockdown, suggesting that MRF4 acts by stabilizing a repressor complex that controls MEF2 activity. These findings open new perspectives in the search for therapeutic targets to prevent muscle wasting, in particular sarcopenia and cachexia

Identification of Compounds and Insecticidal Activity of the Root of Pride of Barbados (Caesalpinia Pulcherrima L)

Caesalpinia pulcherrima (Caesalpiniaceae) is an ornamental plant with several ethnomedicinal uses. The present study was designed to investigate the brine shrimp cytotoxicity and insecticidal activity of oil obtained from C. pulcherrima root. The powdered root was extracted with methanol and then defatted with petroleum ether (40-60oC) to obtain a viscous oil. The oil was investigated for its brine shrimp cytotoxicity and insecticidal activity in vitro. The chemical constituents were identified by Gas chromatography-Mass spectrometry. The oil showed significant lethal effect against Artemia salina (Brine shrimp) with LC50 of 23.85 μg/mL and mild insecticidal activity against Tribolium castaneum and Callosbruchus analis with percentage mortality of 20% and 40% respectively at 1 mg/cm2. GC-MS analysis identified 37 compounds mainly steroids, terpenoids and fatty acids.Keywords: Caesalpinia pulcherrima, chemical constituents, cytotoxicity, insecticidal activity