Ultrafast imaging Raman spectroscopy of large-area samples without stepwise scanning

Step-by-step, time-consuming scanning of the sample is still the state-of-the-art in imaging Raman spectroscopy. Even for a few 100 image points the measurement time may add up to minutes or hours. A radical decrease in measurement time can be achieved by applying multiplex spectrographs coupled to imaging fiber bundles that are successfully used in astronomy. For optimal use of the scarce and expensive observation time at astronomical observatories, special high-performance spectrograph systems were developed. They are designed for recording thousands of spatially resolved spectra of a two-dimensional image field within one single exposure. Transferring this technology to imaging Raman spectroscopy allows a considerably faster acquisition of chemical maps. Currently, an imaging field of up to 1 cm2 can be investigated. For porcine skin the required measurement time is less than 1 min. For this reason, this technique is of particular interest for medical diagnostics, e.g., the identification of potentially cancerous abnormalities of skin tissue

Faseroptischer Sensor und Verfahren zur Herstellung

DE 102009005162 A1 UPAB: 20100806 NOVELTY - The optic fiber sensor has a fiber core (1) within a mantle (2) and a sensor material, which changes color when in contact with the matter under scrutiny. A recess (3) is centered at the end of the fiber, on its optical axis, with an adhesive bond to secure an optically transparent micro ball (4) coated with the sensor dyestuff material (5). USE - The optic fiber sensor is for measurement of materials or their concentration e.g. molecular acids in solutions and gas phases. ADVANTAGE - The micro ball, with the sensor material, is firmly bonded to the end of the optic fiber

An innovative laser-based sensing platform for realtime optical monitoring of oxygen

Known as "gas of life", molecular oxygen is a crucial metabolic factor. Especially in the field of cell biology, the content of ambient oxygen determines proliferation and differentiation. Therefore, it is a mandatory step to monitor and to control the oxygen concentrations in bioreactors for three-dimensional tissue engineering. From experience, the oxygen content of the culture medium does not reflect the circumstances within the cell tissue. Hence, it is important to develop advanced measurement techniques, which indicate the oxygen concentration within the cell carrier. To avoid interferences of the flow conditions and cell growth non-invasive or at least minimal-invasive detection techniques are strongly preferable. In this paper we will describe the principle of the oxygen determination, results from measurements in biological samples

Ultrafast imaging Raman spectroscopy of large-area samples without stepwise scanning

Step-by-step, time-consuming scanning of the sample is still the state-of-the-art in imaging Raman spectroscopy. Even for a few 100 image points the measurement time may add up to minutes or hours. A radical decrease in measurement time can be achieved by applying multiplex spectrographs coupled to imaging fiber bundles that are successfully used in astronomy. For optimal use of the scarce and expensive observation time at astronomical observatories, special high-performance spectrograph systems were developed. They are designed for recording thousands of spatially resolved spectra of a two-dimensional image field within one single exposure. Transferring this technology to imaging Raman spectroscopy allows a considerably faster acquisition of chemical maps. Currently, an imaging field of up to 1 cm2 can be investigated. For porcine skin the required measurement time is less than 1 min. For this reason, this technique is of particular interest for medical diagnostics, e.g., the identification of potentially cancerous abnormalities of skin tissue

Ultrafast imaging Raman spectroscopy of large-area samples without stepwise scanning

Step-by-step, time-consuming scanning of the sample is still the state-of-the-art in imaging Raman spectroscopy. Even for a few 100 image points the measurement time may add up to minutes or hours. A radical decrease in measurement time can be achieved by applying multiplex spectrographs coupled to imaging fiber bundles that are successfully used in astronomy. For optimal use of the scarce and expensive observation time at astronomical observatories, special high-performance spectrograph systems were developed. They are designed for recording thousands of spatially resolved spectra of a two-dimensional image field within one single exposure. Transferring this technology to imaging Raman spectroscopy allows a considerably faster acquisition of chemical maps. Currently, an imaging field of up to 1 cm2 can be investigated. For porcine skin the required measurement time is less than 1 min. For this reason, this technique is of particular interest for medical diagnostics, e.g., the identification of potentially cancerous abnormalities of skin tissue

Decreased Expression of Cytosolic Pyruvate Kinase in Potato Tubers Leads to a Decline in Pyruvate Resulting in an in Vivo Repression of the Alternative Oxidase1[W][OA]

The aim of this work was to investigate the effect of decreased cytosolic pyruvate kinase (PKc) on potato (Solanum tuberosum) tuber metabolism. Transgenic potato plants with strongly reduced levels of PKc were generated by RNA interference gene silencing under the control of a tuber-specific promoter. Metabolite profiling showed that decreased PKc activity led to a decrease in the levels of pyruvate and some other organic acids involved in the tricarboxylic acid cycle. Flux analysis showed that this was accompanied by changes in carbon partitioning, with carbon flux being diverted from glycolysis toward starch synthesis. However, this metabolic shift was relatively small and hence did not result in enhanced starch levels in the tubers. Although total respiration rates and the ATP to ADP ratio were largely unchanged, transgenic tubers showed a strong decrease in the levels of alternative oxidase (AOX) protein and a corresponding decrease in the capacity of the alternative pathway of respiration. External feeding of pyruvate to tuber tissue or isolated mitochondria resulted in activation of the AOX pathway, both in the wild type and the PKc transgenic lines, providing direct evidence for the regulation of AOX by changes in pyruvate levels. Overall, these results provide evidence for a crucial role of PKc in the regulation of pyruvate levels as well as the level of the AOX in heterotrophic plant tissue, and furthermore reveal that these parameters are interlinked in vivo