Supramolecularly regulated artificial transmembrane signal transduction for 'ON/OFF'-switchable enzyme catalysis.

An artificial signal transduction model with a supramolecular recognition headgroup, a membrane anchoring group, and a pro-enzyme catalysis endgroup was constructed. The transmembrane translocation of the transducer can be reversibly regulated by competitive host-guest complexations as an input signal to control an enzyme reaction inside the lipid vesicles.

-Bambusurils are anion-specific transmembrane transporters.

-Bambus[6]urils efficiently transport anions across lipid membranes. A systematic modification of their lipophilic side chains to include various alkyl groups and thioethers reveals that the most efficient chloride transporters are those that agree with Lipinski's rule-of-lipophilicity, exhibiting clog  values close to 5. Furthermore, vesicle anion-transport assays show that the new anion-transporters are independent of the cation identity but exhibit high anion selectivity, NO > Br > Cl > SO, in agreement with the Hofmeister series.

Spread of respiratory infections in student dormitories in China.

Objectives: Student dormitory rooms in China are characterized by small space and high occupancy. This study aims to investigate infection rates for common colds and influenza among college students in a Chinese university and their association with the dormitory environment.

Methods: This study involved two phases.

Hybrid Helical Polymer Nanochannels Constructed by Combining Aromatic Amide and Pyridine-Oxadiazole Structural Sequences.

An effective method is reported to synthesize aromatic helical polymer nanochannels by combining both the well-studied aromatic amide helical codons with pyridine-oxadiazole helical codons into helical structure sequences. With this strategy, a type of helical polymer nanochannel that shows structure-directed transmembrane transport functions is synthesized. Although such nanochannels show relatively weak selectivity for the transportation of alkali metal ions, accessible chemical mutation of helical structure sequences will provide a great chance for the design of desired channel property.

Morphological Transformation between Orthogonal Dynamic Covalent Self-Assembly of Imine-Boroxine Hybrid Polymer Nanocapsules and Thin Films via Linker Exchange.

Orthogonal dynamic covalent self-assembly is used as a facile method for constructing polymer hollow nanocapsules (NCs) and thin films. The bifunctional precursor 4-formylphenylboronic acid is symmetrically installed with a boronic acid group for the boroxine linkage, and an aldehyde group for the Schiff base reaction which can react with twofold symmetry linkers ethylenediamine and para phenylenediamine to attain polymer NCs and nanosheets. Owing to the reversibility of the imine linkages, the mutual morphological transformation between polymer NCs and thin films via an amine-imine-exchange strategy is successfully achieved.

Access to Benzoxazepines and Fully Substituted Indoles via HDDA Coupling.

The HDDA-derived benzyne intermediate was captured by oxazolines based on the addition reaction of benzyne to the C═N double bond. Benzoxazepine derivatives, fused benzoxazepine derivatives, and fully substituted indoles are synthesized in one step. The reaction does not require any catalyst or additives.

Template-Free Construction of Highly Ordered Monolayered Fluorescent Protein Nanosheets: A Bioinspired Artificial Light-Harvesting System.

Using biological materials for light-harvesting applications has attracted considerable attention in recent years. Such materials provide excellent environmental compatibility and often exhibit superior properties over synthetic materials. Herein, inspired by the outstanding energy transfer performance in coelenterates, we constructed a template-free, highly ordered two-dimensional light-harvesting system by covalent-induced coassembly of EBFP2 (donor) and EGFP (acceptor), in which the fluorescent chromophores were well distributed and adopted a fixed orientation.

Supramolecular nanochannels self-assembled by helical pyridine-pyridazine oligomers.

Herein, we demonstrate a supramolecular nanochannel formed by intermolecular π stacking of pyridine-pyridazine helical oligomers, wherein alkali ions could be easily recognized and transported. Importantly, this nanochannel also revealed reversible collection and triggered-release behaviors via modulating the folded and unfolded states of helical pyridine-pyridazine oligomers.

Highly Selective Artificial Potassium Ion Channels Constructed from Pore-Containing Helical Oligomers.

Potassium ion channels specifically transport K ions over Na ions across a cell membrane. A queue of four binding sites in the K channel pore plays significant roles during highly selective conduction. A kind of aromatic helical oligomer was synthesized that can selectively bind K over Na .

Semithiobambus[6]uril is a transmembrane anion transporter.

Semithiobambus[6]uril is shown to be an efficient transmembrane anion transporter. Although all bambusuril analogs (having either O, S or N atoms in their portals) are excellent anion binders, only the sulfur analog is also an effective anion transporter capable of polarizing lipid membranes through selective anion uniport. This notable divergence reflects significant differences in the lipophilic character of the bambusuril analogs.

Biomimetic Transmembrane Channels with High Stability and Transporting Efficiency from Helically Folded Macromolecules.

Membrane channels span the cellular lipid bilayers to transport ions and molecules into cells with sophisticated properties including high efficiency and selectivity. It is of particular biological importance in developing biomimetic transmembrane channels with unique functions by means of chemically synthetic strategies. An artificial unimolecular transmembrane channel using pore-containing helical macromolecules is reported.