Fine pore engineering in a series of isoreticular metal-organic frameworks for efficient C2H2/CO2 separation

The separation of C2H2/CO2 is not only industrially important for acetylene purification but also scientifically challenging owing to their high similarities in physical properties and molecular sizes. Ultramicroporous metal-organic frameworks (MOFs) can exhibit a pore confinement effect to differentiate gas molecules of similar size. Herein, we report the fine-tuning of pore sizes in sub-nanometer scale on a series of isoreticular MOFs that can realize highly efficient C2H2/CO2 separation. The subtle structural differences lead to remarkable adsorption performances enhancement. Among four MOF analogs, by integrating appropriate pore size and specific binding sites, [Cu(dps)2(SiF6)] (SIFSIX-dps-Cu, SIFSIX = SiF62-, dps = 4.4’-dipyridylsulfide, also termed as NCU-100) exhibits the highest C2H2 uptake capacity and C2H2/CO2 selectivity. At room temperature, the pore space of SIFSIX-dps-Cu significantly inhibits CO2 molecules but takes up a large amount of C2H2 (4.57 mmol g−1), resulting in a high IAST selectivity of 1787 for C2H2/CO2 separation. The multiple host-guest interactions for C2H2 in both inter- and intralayer cavities are further revealed by dispersion-corrected density functional theory and grand canonical Monte Carlo simulations. Dynamic breakthrough experiments show a clean C2H2/CO2 separation with a high C2H2 working capacity of 2.48 mmol g−1.

Neurosteroid modulation of GABAA receptor function by independent action at multiple specific binding sites

: Neurosteroids are endogenous modulators of GABAA receptors that mediate anxiety, pain, mood and arousal. The 3-hydroxyl epimers, allopregnanolone (3α-OH) and epi-allopregnanolone (3β-OH) are both prevalent in mammalian brain and produce opposite effects on GABAA receptor function, acting as positive and negative allosteric modulators respectively. This Perspective provides a model to explain the actions of 3α-OH and 3β-OH neurosteroids. The model is based on evidence that the neurosteroid epimers bind to an overlapping subset of specific sites on GABAA receptors, with their net functional effect on channel gating being the sum of their independent effects at each site.

Human Serum Albumin: A Novel Drug Delivery Carrier System

Serum albumin, often referred to simply as albumin, is a globular protein that in humans is encoded by the ALB gene. Albumin is a multifaceted, highly soluble, stable, nontoxic, non-poisonous, biocompatible and biodegradable plasma protein. Albumin has been widely studied as a protein carrier for drug delivery. Because of its versatile nature, it can also be used for the delivery of the hormones, metals and fatty acids by binding to its specific binding sites. Various studies revealed that albumin can be used to increase the circulating half-life and bioavailability of drug molecules which are smaller than the renal filtration threshold and are rapidly lost from the circulation leading to limiting therapeutic potential. This review article presents advantages, disadvantages, functions, importance, different nanoparticles that can be crowned with an albumin and the special features of albumin as a drug carrier, and how the understanding of these features is currently being employed to optimize the circulatory half-life albumin.

Contribution of technology to human cell properties

After explaining the meaning of SARS-CoV2, the protection rules for the disease caused by this virus are described in order to eradicate the resulting pandemic. Methods to differentiate asymptomatic from symptomatic patients will be mentioned. Human lungs, heart, kidney, endothelium and erythrocyte have specific binding sites for the SARS-CoV2. The aim of this opinion was to highlight some new disposable technology to identify two cell properties. One of them is the vascular endothelial cell (EC) receptor binding to the SARS-CoV2 and the other is related with red blood cells (RBCs) as SARS-CoV2 carrier.

A Note about Crosslinking Density in Imprinting Polymerization

Imprinting polymerization is an exciting technique since it leads to specific binding sites, which are the basis of a variety of applications, such as sensors, detectors, and catalysts. The specific binding sites are created using templates and then fixing the structure of the binding site with crosslinking. The literature review of imprinting polymerizations shows that the crosslinking density governs the physical properties of the resulting molecularly imprinted polymer (MIP). It is also a factor governing the capacity and the selectivity of MIPs. Reviewing polymer science data and theory, the crosslinking density commonly used in MIP synthesis is unusually high. The data reviewed here suggest that more research is needed to determine the optimal crosslinking density for MIPs.

Modeling the Effect of Binding Kinetics in Spatial Drug Distribution in the Brain

A 3-dimensional mathematical model is developed to determine the effect of drug binding kinetics on the spatial distribution of a drug within the brain. The key components, namely, transport across the blood-brain barrier (BBB), drug distribution in the brain extracellular fluid (ECF), and drug binding kinetics are coupled with the bidirectional bulk flow of the brain ECF to enhance the visualization of drug concentration in the brain. The model is developed based on the cubical volume of a brain unit, which is a union of three subdomains: the brain ECF, the BBB, and the blood plasma. The model is a set of partial differential equations and the associated initial and boundary conditions through which the drug distribution process in the mentioned subdomains is described. Effects of drug binding kinetics are investigated by varying the binding parameter values for both nonspecific and specific binding sites. All variations of binding parameter values are discussed, and the results show the improved visualization of the effect of binding kinetics in the drug distribution within the brain. For more realistic visualization, we suggest incorporating more brain components that make up the large volume of the brain tissue.