Molecular background

In Chapter 11, by Phill Jones et al., biomedical FRET-FLIM applications are reviewed and illustrated. The molecular background of a variety of diseases (e.g., Alzheimer s disease) can be uncovered by using FRET-FLIM. In this major funding area, the killer -applications of the technology are and will be found, leading to a further boost of the implementation and commercial availability of high-end microscopes with automated acquisition and standardized analysis features. 

A recent example of such research was an effective experiment in January 2008 presented by Gosh and Gupta-Bhattacharya (2008). The researchers presented the results of an in silico study whose aim was to determine the molecular background of cross-reactivity and activity of Bet vl allergens present in pollen and plant foods. 

With contributions from an international team of research specialists, the book explains the basic mechanisms of allergenic reactions in humans, the molecular background of these mechanisms, and the problems of food tolerance and intolerance. It also discusses the issues related to common treatments of food allergies and the narrow groups into which they are categorized. 

H. Becker-Ross, S. Florek, U. Heitmann, Observation, identification and correction of structured molecular background by means of continuum source AAS - determination of selenium and arsenic in human urine, J. Anal. Atom. Spectrom., 15 (2000), 137. 

In practice, first the absorption of the resonance line is measured. This is a measure of the absorption signal equivalent to the atomic absorption plus molecular background absorption. Secondly, absorption due to the molecular background is measured and the difference between the two is the true atomic absorption measurement. The bases of the techniques for background absorption are as follows. 

An alternative procedure for the Zeeman background corrector is to operate the hollow cathode continuously but to expose the sample to an alternating magnetic field. The sample atoms absorb at the resonance line when not exposed to the magnetic field, but develop hyperfine structure and do not absorb the resonance line when the magnet is turned on. With the magnetic field on, absorption of the resonance line is a measure of molecular background. From the combined data, the net atomic absorption can be measured. 

Praznik, W., Mundigler, N., Kogler, A., Pelzl, B., and Huber, A. (1999). Molecular background of technological properties of selected starches. Starch/Stdrke 51,197-211. 

Epidemiology Risk Factors and Molecular Background of Atherosclerosis... 

Transplantation of an alien gene into alfalfa was the first successful experiment in the world carried out with this important papilionaceous fodder plant. Experiments with nitrogen bonding were carried out, the isolation of Rhizobium genes was studied, and the molecular background of symbiosis has been analyzed. 

Accelerator Mass Spectrometry is a special tool for quantitative measurements of very long-lived radionuclides. This technique consists of counting the nuclides themselves instead of waiting for their decay. As for as the tandem accelerator is concerned, no molecular background exists because of the stripping process. Any isobaric background is also drastically suppressed due to the nuclear techniques involved in the measurements. There occurs an extremely wide area of applications in different fields because of the capability of the AMS technique to determine the radioisotopes at the faintest level (the isotopic concentrations down to the range of 10 in some cases). 

Typical adverse effects related to biotechnologically-derived pharmaceuticals are not due simply to impurities or accidental overdose, but can theoretically be associated with the molecular background of the receptor, such as pleiotropisms, redundancies, receptor sub-unit function and possible unexpected amplification of receptor signalling. Several examples of receptor-mediated toxicity with biotech products are shown in Table 6.1 (Inoue, 1996). 

Fig. 87. Time-resolved absorption spectrum of NH4H2PO4. Observation interval 120 pixels, a human urine sample in the vicinity of the As linear dispersion 1.6 pm/pixel 110 scans 193.696 nm line, (A) before, and (B) after integration time 48 ms per scan. (Reproduced molecular background correction with with permission from Ref. [291].)...

Skimming the gas outside the zone of silence produces very low sensitivity. The profile of the skimmer cone tip is sharper than that of the sample cone, because the presence of the skimmer tip in the zone of silence disturbs the gas expansion and in order to maintain optimum ion sampling, this disturhance should he minimisecL The shape of the skimmer and the condition of the skimmer tip both have a profound effect on instrument transmission, mass response, molecular backgrounds, matrix effects and even the subsequent geometry of the ion optics. 

Barragan A, Spillmann D, Kremsner PG, Wahlgren M, Carlson J (1999) Plasmodium falciparum. molecular background to strain-specific rosette disruption by glycosaminoglycans and sulfated glycoconjugates. Exp Parasitol 91 133-43. 

---