Search results for "Fluorometry"
showing 10 items of 30 documents
Gametic and somatic embryogenesis through in vitro anther culture of different Citrus genotypes
2015
Abstract: In vitro tissue culture represents a useful technique for advancing Citrus breeding and propagation. Among in vitro regeneration systems, anther culture is commonly used to produce haploids and doubled haploids for a fast-track producing homozygous lines, in comparison with the traditional self-pollination approach, which involves several generations of selfing. In addition, anthers culture can produce somatic embryos that can also be used for clonal propagation. In this study, two thermal shocks were applied to the anthers of six Citrus genotypes (two clementine and four sweet oranges), just after they were put in culture. The response obtained was different depending on the geno…
Sample Preparation Improvement in Polycyclic Aromatic Hydrocarbons Determination in Olive Oils by Gel Permeation Chromatography and Liquid Chromatogr…
2005
Abstract The determination of 15 polycyclic aromatic hydrocarbons (PAHs) in olive oil samples has been improved in order to obtain a fast methodology with a low limit of detection through the combination of liquid–liquid extraction with acetonitrile and preparative gel permeation chromatography (GPC) prior to the injection of purified extracts into a C18 column. Acetonitrile–water was used as the mobile phase with a gradient from 50 to 95%, w/w, acetonitrile in 30 min. The oven temperature was maintained at 15°C, and fluorometric detection was made at a fixed excitation wavelength of 264 nm and variable, optimal emission wavelength for each analyte ranging from 352 nm for 11-H-benzo(b)fluor…
Effects of the Breathe Right Nasal Strips on Nasal Ventilation
1997
The Breathe Right nasal strips are more and more commonly used, mainly by athletes, who hope to enhance their physical performance in competition and training. The effect of the device in such situations is uncertain and perhaps somewhat controversial. To investigate the effects of the nasal strips on nasal ventilation, 20 Caucasian individuals were objectively assessed using anterior rhinomanometry and acoustic rhinometry. The results showed a significant increase in all subjects of transnasal airflow and in the average cross-sectional area of the nasal cavity that quantifies objectively the subjective impression of improved nasal breathing. In such patients where an improvement in nasal …
Evaluation of the Stratus® CS Acute Care™ D-dimer assay (DDMR) using the Stratus® CS STAT Fluorometric Analyzer: A prospective multisite study for ex…
2012
Abstract Background D-dimer testing is an integral part of the diagnostic algorithm in excluding patients with venous thromboembolism. In this study, we prospectively evaluated the Stratus DDMR D-dimer test in patients suspected of pulmonary embolism (PE) and deep vein thrombosis (DVT). Methods Patients suspected of venous thromboembolism were prospectively enrolled at four different clinical sites, with sodium citrate and lithium heparin plasma was tested using the DDMR D-dimer test on the Stratus CS analyzer. Results 1,012 patients were enrolled for analysis, with 85/603 (14.1%) patients with PE and 80/443 (18.1%) with DVT, and four of the patients (0.4%) with PE and DVT. For the samples …
Theoretical prediction of the native fluorescence of pharmaceuticals
2009
At present, to search fluorescent compounds or to increase the native fluorescence is an active research line specially and not only with analytical purposes. On some analytical areas and from the early times of applications of fluorescence (mid-fifties) the fluorimeter was defined as the suitable detector for determination of pharmaceuticals and subsequently, this detection mode has been widely applied. Therefore, it is mandatory to develop new strategies to discover or to enhance in a simple way the native fluorescence of organic compounds to increase the number of analytes to be determined by direct fluorescence. In the present paper are studied further applications of a new tool suitabl…
Autoinhibition of nicotinic release of noradrenaline from postganglionic sympathetic nerves
1970
1. The effects of nicotine, DMPP (1,1-dimethylphenylpiperazine) and acetylcholine (plus atropine) on the isolated rabbit heart were investigated. Heart rate, amplitude of contraction, coronary flow and output of noradrenaline into the perfusate were recorded. Noradrenaline was estimated fluorimetrically. 2. All nicotinic drugs evoked a dose-dependent output of noradrenaline and increased the rate and the amplitude of contraction. Increases of heart rate in response to nicotine and DMPP and increases of amplitude of contraction in response to all nicotinic drugs were clearly related to the output of noradrenaline. 3. The dose-response curves of the noradrenaline output evoked by nicotine, DM…
A muscarinic inhibition of the noradrenaline release evoked by postganglionic sympathetic nerve stimulation
1969
1. The noradrenaline output from isolated rabbit hearts perfused with Tyrode solution was estimated fluorimetrically. The postganglionic sympathetic nerves of the heart were stimulated (10 shocks/sec; 1 msec) for three 1 min periods with intervals of 10 min. 2. The noradrenaline output evoked by 3 consecutive stimulation periods decreased exponentially. 3. Acetylcholine (10−9–10−6 g/ml) administered continuously one min before to one min after the second stimulation caused a dose-dependent reduction of the noradrenaline output evoked by the second stimulation to as low as 19% of the normal value. Acetylcholine in the concentrations applied did not cause a noradrenaline output by itself. 4. …
Optical mercury sensing using a benzothiazolium hemicyanine dye.
2006
[structure: see text] The selectivity and sensitivity of a benzothiazolium hemicyanine dye toward mercury(II) in aqueous solutions are described. Mercury ions coordinate to the dye forming a 1:1 complex. This interaction induces a color change in the dye at micromolar concentrations of mercury. Furthermore, the color change and quenching of the dye emission are selective for mercury when compared with other ions such as lead(II), cadmium(II), zinc(II), or iron(II).
Lichen rehydration in heavy metal polluted environments: Pb modulates the oxidative response of both Ramalina farinacea thalli and its isolated micro…
2014
Lichens are adapted to desiccation/rehydration and accumulate heavy metals, which induce ROS especially from the photobiont photosynthetic pigments. Although their mechanisms of abiotic stress tolerance are still to be unravelled, they seem related to symbionts' reciprocal upregulation of antioxidant systems. With the aim to study the effect of Pb on oxidative status during rehydration, the kinetics of intracellular ROS, lipid peroxidation and chlorophyll autofluorescence of whole Ramalina farinacea thalli and its isolated microalgae (Trebouxia TR1 and T. TR9) was recorded. A genetic characterization of the microalgae present in the thalli used was also carried out in order to assess possib…
The nucleosome remodeling factor ISWI functionally interacts with an evolutionarily conserved network of cellular factors
2010
Abstract ISWI is an evolutionarily conserved ATP-dependent chromatin remodeling factor playing central roles in DNA replication, RNA transcription, and chromosome organization. The variety of biological functions dependent on ISWI suggests that its activity could be highly regulated. Our group has previously isolated and characterized new cellular activities that positively regulate ISWI in Drosophila melanogaster. To identify factors that antagonize ISWI activity we developed a novel in vivo eye-based assay to screen for genetic suppressors of ISWI. Our screen revealed that ISWI interacts with an evolutionarily conserved network of cellular and nuclear factors that escaped previous genetic…