Praktische Erfahrungen mit Mikro- und Minicomputern im Industrielaboratorium

Ohne Zusammenfassung

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Practical experiences with micro- and minicomputers in industrial laboratories

     

A Double‐Clicking Bis‐Azide Fluorogenic Dye for Bioorthogonal Self‐Labeling Peptide Tags

Herein, we give the very first example for the development of a fluorogenic molecular probe that combines the two‐point binding specificity of biarsenical‐based dyes with the robustness of bioorthogonal click‐chemistry. This proof‐of‐principle study reports on the synthesis and fluorogenic characterization of a new, double‐quenched, bis‐azide fluorogenic probe suitable for bioorthogonal two‐point tagging of small peptide tags by double strain‐promoted azide–alkyne cycloaddition. The presented probe exhibits remarkable increase in fluorescence intensity when reacted with bis‐cyclooctynylated peptide sequences, which could also serve as possible self‐labeling small peptide tag motifs.     

NIR Mega‐Stokes Fluorophores for Bioorthogonal Labeling and Energy Transfer Systems–An Efficient Quencher for Daunomycin

A set of new azide‐ and alkyne‐bearing lepidinium‐based fluorophores were synthesized for bioorthogonal labeling schemes. These fluorescent dyes all show large Stokes‐shifts with emission maxima in the near‐infrared (NIR) region of the electromagnetic spectrum. The applicability of these dyes in the construction of energy‐transfer systems was tested using one of these new fluorescent tags and daunomycin (Dau), an anticancer drug with fluorescent features. These daunomycin conjugates are the very first examples of fluorescently modulated constructs of this anticancer agent. The dually labeled architectures proved that the applied fluorescent dye can be utilized as an efficient quencher for daunomycin. Enzymatic cleavage of a dually labeled enzyme substrate resulted in full recovery of the fluorescence of daunomycin. Such fluorescently modulated Dau conjugates can provide useful information for the mechanism of action of Dau‐regulated cell death processes.     

A validated method for measurement of serum total,serum free,and salivary cortisol,using high-performance liquid chromatography coupled with high-resolutionESI-TOF mass spectrometry

Blood cortisol level is routinely analysed in laboratory medicine, but the immunoassays in widespread use have the disadvantage of cross-reactivity with some commonly used steroid drugs. Mass spectrometry has become a method of increasing importance for cortisol estimation. However, current methods do not offer the option of accurate mass identification. Our objective was to develop a mass spectrometry method to analyse salivary, serum total, and serum free cortisol via accurate mass identification. The analysis was performed on a Bruker micrOTOF high-resolution mass spectrometer. Sample preparation involved protein precipitation, serum ultrafiltration, and solid-phase extraction. Limit of quantification was 12.5 nmol L^?1 for total cortisol, 440 pmol L^?1 for serum ultrafiltrate, and 600 pmol L^?1 for saliva. Average intra-assay variation was 4.7 %, and inter-assay variation was 6.6 %. Mass accuracy was <2.5 ppm. Serum total cortisol levels were in the range 35.6–1088 nmol L^?1, and serum free cortisol levels were in the range 0.5–12.4 nmol L^?1. Salivary cortisol levels were in the range 0.7–10.4 nmol L^?1. Mass accuracy was equal to or below 2.5 ppm, resulting in a mass error less than 1 mDa and thus providing high specificity. We did not observe any interference with routinely used steroidal drugs. The method is capable of specific cortisol quantification in different matrices on the basis of accurate mass identification.     

Integrals and derivatives connected to the r-Lambert function

In this paper, we derive some formulas for higher order derivatives of r-Lambert functions. Moreover, an integration formula involving powers of r-Lambert function is obtained.     

Synthesis,conformation and cytotoxicity of new,branched polymeric polypeptides containing hydrophobic amino acid or arginine moiety

In this paper we report on the synthesis and solution conformation of a new set of structurally related polycationic branched chain polypeptides (poly[Lys(X _i -dl-Ala _m )]) with hydrophobic (Ile, Nle, Val) or cationic (Arg) amino acids at the N-terminal end of the side chains as well as their cytotoxic effect on murine bone marrow derived macrophages. Solution conformation of the polypeptides was studied with circular dichroism spectroscopy under different conditions (pH, ionic strength). The results of these comparative studies indicate that a) polypeptides could adopt an ordered (mainly helical) conformation at physiological pH and salt concentration (pH 7.4, 0.2 M NaCl); b) the nature of side chain terminal amino acid (X) could determine under which conditions the ordered structure was formed. Thus, the solution conformation of branched polypeptides could be modulated by the selection of amino acid X under physiological conditions. All polypeptides with hydrophobic amino acid at the terminal position were essentially non-toxic on macrophages, whereas the polypeptide with terminal Arg proved to be markedly cytotoxic.

     

Integrals of weighted maximal logarithmic kernels on bounded Vilenkin groups

The integrals of maximal Riesz and Nörlund kernels are infinite, so we have to use some weight function to “pull them back” to the finite. In this paper we give necessary and sufficient conditions for the weight function to get a finite integral on bounded Vilenkin groups. For our motivation we refer the readers to [4], [5], [6].