Ein analogon zum Primzahlsatz für algebraische Funktionenkörper

LetF be an algebraic function field of one variable over a finite field . We prove that

Using immobilized enzymes to reduce RNase contamination in RNase mapping of transfer RNAs by mass spectrometry

RNase (ribonuclease) mapping by nucleobase-specific endonucleases combined with mass spectrometry (MS) is a powerful analytical method for characterizing ribonucleic acids such as transfer RNAs. Typical free solution enzymatic digestion of RNA samples results in a significant amount of RNase being present in the sample solution analyzed by MS. In some cases, the RNase can lead to contamination of the high performance liquid chromatography and MS instrumentation. Here we investigate and compare several different approaches for reducing or eliminating contaminating RNase from the digested RNA sample before LC-MS analysis. Approaches using immobilized RNases were found to be most effective, with no enzyme carryover into the digested sample detected. Among the various options for immobilized RNases, we show that carbodiimide-based reactions can be used to couple RNases to carboxylic acid-terminated magnetic beads. The immobilized enzymes retain biological activity, are re-usable, and do not interfere with subsequent LC-MS analysis of the expected RNase digestion products. The use of immobilized RNases provides a simple approach for eliminating enzyme contamination in mass spectrometry-based RNase mapping experiments.     

Synthesis,Antioxidant, and Antimicrobial Activity of Novel Hydrazones,Arylidenes, and Heterocycles Using 3,5-Diphenylcyclohex-2-en-1-one

Russian Journal of General Chemistry - Reactions of 3,5-diphenylcyclohex-2-en-1-one (1) with several chemical reagents have led to a variety of novel biologically active hydrazones, arylidene...     

The Rationality of Irrationality in the Monty Hall Problem

The rational solution of the Monty Hall problem unsettles many people. Most people, including the authors, think it feels wrong to switch the initial choice of one of the three doors, despite having fully accepted the mathematical proof for its superiority. Many people think the chances are 50‐50 between their options, but still strongly prefer to stay with their initial choice. Is there some sense behind these irrational feelings? Here, the possibility is entertained that intuition solves the problem of how to behave in a real game show and not the abstract textbook version. A real showmaster sometimes plays evil, either to make the show more interesting, to save money, or because he is in a bad mood. A moody showmaster erases any information advantage the guest could extract by him opening other doors which drives the chance of the car being behind the chosen door toward 50%. Furthermore, the showmaster could try to read or manipulate the guest's strategy to the guest's disadvantage. Given this, the preference to stay with the initial choice turns out to be a very rational defense strategy of the show's guest against the threat of being manipulated by its host.     

A Conformationally Frozen Peptoid Boosts CXCR4 Affinity and Anti-HIV Activity

There can be only one: Using a peptoid motif obtained by shifting the arginine side chain of a pentapeptide previously developed by Fujii et?al. to the neighboring nitrogen atom restricts the conformational freedom and yields a conformationally homogeneous peptide with a 100-fold higher binding affinity to the chemokine receptor CXCR4 in the picomolar range. Its efficiency to inhibit HIV-1 infections is also demonstrated.     

Access to new Janus head ligands: linking sulfur diimides and phosphanes for hemilabile tripodal scorpionates

Reactions of lithium dialkyl/phenyl phosphanylmethylides, RR'PCH(X)Li (R, R' = Me, Et, Ph and R = Me, R' = Ph; X = H or Me), with sulfur diimides S(NR')2 (R' = (t)Bu or SiMe3) in an equimolar ratio yielded Janus head complexes with the structural motif [Li{RR'PCH(X)S(NR')2}]2 (R' = (t)Bu, SiMe3). The basic core of these dimeric complexes is composed of a (LiN)(2) four-membered ring containing two four-coordinated lithium atoms. A lithium complex of the new Janus head ligand with another structural motif [TMEDA·Li{Ph(2)PCH(2)S(NSiMe3)2}] (6) could be isolated from the reaction of [Ph2PCH2Li·TMEDA] with S(NSiMe3)2. Two monomeric complexes [Mg{Me2PCH2S(NR')2}2] (7, 8) were synthesised by a straightforward reaction of [Li{Me2PCH2S(NR')2}2] with MgCl2 in pentane. The magnesium atom is chelated by one phosphorus atom and two nitrogen atoms of each unit of the hemilabile ligand in a tripodal manner, leading to octahedral geometry around the magnesium cation. A complete analysis of [Ph2PCH2(SNSiMe3)(HNSiMe3)] (9) is also described in which one nitrogen atom of the imido moiety is protonated.