Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, P.O. Box 286, 1519 Budapest, Hungary.
Published: August 2018
AI Article Synopsis
Article Abstract
The effect of the chain length of the alkyl and alkoxy substituents on the binding characteristics of 1-alkyl-6-alkoxy-quinolinium cations was studied using 4-sulfonatocalix[4]arene (SCX4) and 4-sulfonatocalix[6]arene (SCX6) in neutral aqueous solutions at 298 K. Isothermal calorimetric titrations showed enthalpy-controlled inclusion with 1:1 stoichiometry. The equilibrium constants of complexation were always larger for the confinement in SCX4 than in its SCX6 homologue because the better matching between the host and guest sizes allowed more exothermic interaction. The binding affinity diminished with the lengthening of the aliphatic chain of the guests in the case of the association with SCX4, but insignificant change was found for SCX6 complexes. The most substantial change in the enthalpic and entropic contributions to the driving force of complex production occurred when the alkyl chain was linked to the heterocyclic nitrogen and the number of its carbon atoms varied between 1 and 4. H NMR spectra evidenced that in SCX6, the 1-alkyl-6-alkoxy-quinolinium cations could be included within the macrocycle cavity. In the case of SCX4, the quinolinium ring is always inside the host, but the alkyl chain is included within SCX4 only for a short chain length ( up to 4). In contrast, the alkoxy chain displays a very weak interaction with the cavity irrespective of the length. Because of the outward orientation from the host, the lengthening of the alkoxy substituent of the quinolinium moiety barely influenced the thermodynamics of inclusion in SCX4. Distinct linear enthalpy-entropy correlations were found for the encapsulation in SCX4 and SCX6.
The enzyme N-acetyltransferase 2 (NAT2) plays an important role in metabolism and detoxification of xenobiotics, including carcinogens and medications. We aimed to assess the contribution of the NAT2 polymorphism to susceptibility to inflammatory bowel disease (IBD) in the Polish population. The study involved 101 IBD patients and 100 healthy controls.
The branched structure of amylose was probed using concanavalin A (ConA) lectin, which forms precipitable aggregates with highly branched glucans, such as glycogen and amylopectin. Rice (japonica cultivar) amylose was fractionated from de-fatted, gelatinized starch by precipitation with 1-butanol (BuOH) and purified by ultracentrifugation and repeated crystallization. The purified amylose still has short side chains, whose chain-length (CL) distribution resembles that of amylopectin.
Introduction: Following a preliminary work validating the technological feasibility of an adaptive workflow with Ethos for whole-breast cancer, this study aims to clinically evaluate the automatic segmentation generated by Ethos.
Material And Methods: Twenty patients initially treated on a TrueBeam accelerator for different breast cancer indications (right/left, lumpectomy/mastectomy) were replanned using the Ethos emulator. The adaptive workflow was performed using 5 randomly selected extended CBCTs per patient.
Low temperature is the main strategy to preserve fruit quality post-harvest, in the supply chain. Low temperatures reduce the respiration, ethylene emission, and enzymatic activities associated with senescence. Unfortunately, peaches are sensitive to low temperatures if exposed for long periods, resulting in physiological disorders that can compromise commercial quality.
Objectives: To determine the association between telomere length (TL) and age-related macular degeneration (AMD) and examine the potential variations with sex and ethnicity.
Methods: Population-based, cross-sectional study. A total of 52,083 participants from the UK Biobank were included.
