RNA diversification by a self-reproducing ribozyme revealed by deep sequencing and kinetic modelling.

We demonstrate that a recombinase ribozyme achieves multiple functions in the same reaction network: self-reproduction, iterative elongation and circularization of other RNAs, leading to synthesis of diverse products predicted by a kinetic model. This shows that key mechanisms can be integrated and controlled toward Darwinian evolution in RNA reaction networks.

[Endoscopic treatment of esophageal anastomotic leakage using vacuum-assisted closure system].

Objective: To analyze the effectiveness of vacuum-assisted closure system for esophageal anastomotic leakage.

Material And Methods: There were 10 patients with upper gastrointestinal anastomotic leakage who were treated at our institution in 2015-2018. Vacuum aspiration system was applied in all cases.

Nano-thin 2D Soft Materials - Design Principles and Prospects.

Established less than a decade ago, the fascinating field of two-dimensional (2D) soft materials is advancing continuously towards widespread recognition. After demonstrating the feasibility of obtaining nano-thin supramolecular sheets and morphologically related tubular objects, considerable efforts are being undertaken to explore the functional potential of soft nanosheets. Self-assembly is a major tool for the controlled formation of nanometre-sized 2D objects.

DNA-inspired oligomers: from oligophosphates to functional materials.

To exert its role of a functional polymer, DNA relies on a molecular self-assembly process that is driven by the interactions of only four units placed in a defined order. Extending the structural diversity of recognition motifs in DNA, to and beyond analogues of the nucleobases, will open doors to self-assembled materials with advanced programmable properties. DNA-inspired systems are becoming useful for numerous applications unachievable by the nucleic acids in their native composition.

Facile One-Pot Parallel Synthesis of 3-Amino-1,2,4-triazoles.

A 1,2,4-triazole motif is present in numerous commercialized and investigational bioactive molecules. Despite its importance for medicinal chemistry, there is a lack of convenient combinatorial approaches toward this molecular core. Herein, we present a synthetic strategy suitable for the quick preparation of a library of structurally diverse 1,2,4-triazoles in a one-pot setting.

Morphological diversity of supramolecular polymers of DNA-containing oligopyrenes - formation of chiroptically active nanosheets.

The effect of DNA on the morphology of supramolecular polymers assembled from chimeric DNA-pyrene oligophosphodiesters in water is described. The number of deoxynucleotides determines if the self-assembly yields 1D or 2D structures. A single guanosine nucleotide attached to a heptapyrenotide induces chiroptical activity in self-assembled nanosheets.

Silica Mineralization of DNA-Inspired 1D and 2D Supramolecular Polymers.

The preparation of hybrid materials from supramolecular polymers through the sol-gel process is presented. Supramolecular polymers are assembled from phosphodiester-linked pyrene oligomers and act as water-soluble one- or two-dimensional templates for silicification. The fibrillary and planar morphologies of the assemblies, as well as the excitonic interactions between the chromophores, remain unaffected by the silicification process.

Functional DNA-grafted supramolecular polymers - chirality, cargo binding and hierarchical organization.

The synthesis, characterization and functionalization of DNA-grafted supramolecular polymers are described. Cargo loading of the helical supramolecular assemblies with gold nanoparticles is demonstrated.

Pathway Diversity in the Self-Assembly of DNA-Derived Bioconjugates.

The pathway diversity of the self-assembly of amphiphilic DNA-pyrene conjugates is described. The hydrophobic pyrene units drive the self-assembly of the anionic oligomers in an aqueous environment into ribbon-shaped, DNA-grafted supramolecular polymers. Isothermal mixing of two types of sorted ribbons, each of which contains only one of two kinds of complementary oligonucleotides, results in the formation of tight networks.

From ribbons to networks: hierarchical organization of DNA-grafted supramolecular polymers.

DNA-grafted supramolecular polymers (SPs) allow the programmed organization of DNA in a highly regular, one-dimensional array. Oligonucleotides are arranged along the edges of pyrene-based helical polymers. Addition of complementary oligonucleotides triggers the assembly of individual nanoribbons resulting in the development of extended supramolecular networks.

Tubes or sheets: divergent aggregation pathways of an amphiphilic 2,7-substituted pyrene trimer.

The self-assembly of an amphiphilic 2,7-linked pyrene trimer in an aqueous environment into two morphologically related forms is described. Supramolecular polymerization leads to the simultaneous formation of nanosheets and nanotubes.

Hydrodynamic and Thermophoretic Effects on the Supramolecular Chirality of Pyrene-Derived Nanosheets.

Chiroptical properties of two-dimensional (2D) supramolecular assemblies (nanosheets) of achiral, charged pyrene trimers (Py3 ) are rendered chiral by asymmetric physical perturbations. Chiral stimuli in a cuvette can originate either from controlled temperature gradients or by very gentle stirring. The chiroptical activity strongly depends on the degree of supramolecular order of the nanosheets, which is easily controlled by the method of preparation.

DNA-Grafted Supramolecular Polymers: Helical Ribbon Structures Formed by Self-Assembly of Pyrene-DNA Chimeric Oligomers.

The controlled arraying of DNA strands on adaptive polymeric platforms remains a challenge. Here, the noncovalent synthesis of DNA-grafted supramolecular polymers from short chimeric oligomers is presented. The oligomers are composed of an oligopyrenotide strand attached to the 5'-end of an oligodeoxynucleotide.

Assembling multiporphyrin stacks inside the DNA double helix.

Double stranded DNA hybrids containing up to four consecutive, face-to-face stacked porphyrins are described. Non-nucleosidic, 5,15-bisphenyl-substituted porphyrin building blocks were incorporated into complementary oligonucleotide strands. Upon hybridization multiple porphyrins are well accommodated inside the DNA scaffold without disturbing the overall B-DNA structure.

[The development of severe methemoglobinemia in patients receiving "Almagel A"].

This clinical case and the literature review show possible development of methemoglobinemia due to the use of local anesthetics, included in drugs for the gastrointestinal diseases treatment, in particular benzocaine, which is the methaemoglobin forming agent. These drugs are common and often taken by the patients themselves without any control. The aim of our paper is to draw the attention of physicians to the risk of the widely known drug administration which can be purchased without a prescription.

Formation of two-dimensional supramolecular polymers by amphiphilic pyrene oligomers.

Reading the bands: Amphiphilic pyrene trimers self-assemble into two-dimensional, supramolecular polymers in aqueous medium. Folding and aggregation processes are accompanied by simultaneous development of J- and H-bands and significant changes in the fluorescence properties. The formation of sheet-like nano-structures is confirmed by AFM.