Discrete Spot (discrete + spot)

Distribution by Scientific Domains


Selected Abstracts


Fully automated liquid extraction-based surface sampling and ionization using a chip-based robotic nanoelectrospray platform,

JOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 3 2010
Vilmos Kertesz
Abstract A fully automated liquid extraction-based surface sampling device utilizing an Advion NanoMate chip-based infusion nanoelectrospray ionization system is reported. Analyses were enabled for discrete spot sampling by using the Advanced User Interface of the current commercial control software. This software interface provided the parameter control necessary for the NanoMate robotic pipettor to both form and withdraw a liquid microjunction for sampling from a surface. The system was tested with three types of analytically important sample surface types, viz., spotted sample arrays on a MALDI plate, dried blood spots on paper, and whole-body thin tissue sections from drug dosed mice. The qualitative and quantitative data were consistent with previous studies employing other liquid extraction-based surface sampling techniques. Published in 2009 by John Wiley & Sons, Ltd. [source]


The Coronary Sinus as a Focal Source of Paroxysmal Atrial Fibrillation: More Evidence for the ,Fifth Pulmonary Vein'?

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 8 2007
THOMAS ROSTOCK M.D.
The coronary sinus (CS) has been described as a substrate being involved in the atrial fibrillation (AF) process. However, there are no data describing the CS as a single source of AF. We report a patient with paroxysmal AF who demonstrated an arrhythmogenic focus within the proximal CS as single source initiating and driving AF. This discrete spot was characterized by a sharp "pulmonary vein-like" spike potential preceding every beat during AF and following the atrial potential during sinus rhythm. Radiofrequency ablation at that site led to elimination of the spike potential, disappearance and noninducibility of AF. [source]


Molecular detection and , -glucuronidase expression of gus -marked Bacillus subtilis L-form bacteria in developing Chinese cabbage seedlings

JOURNAL OF APPLIED MICROBIOLOGY, Issue 2 2003
E. Tsomlexoglou
Abstract Aim: To detect L-form bacteria in developing Chinese cabbage seedlings. Methods and Results: Stable Bacillus subtilis L-forms were genetically modified to express the gus gene (encoding , -glucuronidase). Germinated seeds of Chinese cabbage were soaked in mannitol based suspensions of the L-form bacteria or with mannitol alone and after washing were grown in aseptic conditions on plant growth medium. Histochemical staining of , -glucuronidase activity (X-gluc) and Polymerase Chain Reaction (PCR) detection of the gus gene were achieved in the L-form associated seedlings. , -Glucuronidase was localized in discrete spots, mainly in the roots with staining, and was also observed in the cotyledons and base of stems. Correlation was observed between PCR detection of the gus gene and histochemical staining with detection in similar tissues. Stable L-form bacteria were non-culturable after their association with plant material. Conclusions: The gus reporter gene system with its associated histological staining for enzyme activity was used successfully for detecting B. subtilis L-form bacteria in plant material. Significance and Impact of the Study: These molecular marked L-forms should provide a specific and sensitive technique for detecting L-form bacteria in planta and offer a method for further understanding the L-form/plant association. [source]


Thermographic visualization of cell death in tobacco and Arabidopsis

PLANT CELL & ENVIRONMENT, Issue 1 2001
L. Chaerle
ABSTRACT Pending cell death was visualized by thermographic imaging in bacterio-opsin transgenic tobacco plants. Cell death in these plants was characterized by a complex lesion phenotype. Isolated cell death lesions were preceded by a colocalized thermal effect, as previously observed at sites infected by tobacco mosaic virus (TMV) (Chaerle et al. 1999Nature Biotechnology 17, 813,816). However, in most cases, a coherent front of higher temperature, trailed by cell death, initiated at the leaf base and expanded over the leaf lamina. In contrast to the homogenous thermal front, cell death was first visible close to the veins, and subsequently appeared as discrete spots on the interveinal tissue, as cell death spread along the veins. Regions with visible cell death had a lower temperature because of water evaporation from damaged cells. In analogy with previous observations on the localized tobacco,TMV interaction (Chaerle et al. 1999), the kinetics of thermographic and continuous gas exchange measurements indicated that stomatal closure preceded tissue collapse. Localized spontaneous cell death could also be presymptomatically visualized in the Arabidopsis lsd2 mutant. [source]