Unraveling Anomalies in Preferential Liquid Transport through the Intrinsic Pores of Cyclodextrin in Polyester Nanofilms.

The precise manipulation of the porous structure of the nanofiltration membrane is critical for unlocking enhanced separation efficiencies across various liquids and solutes. Ultrathin films of crosslinked macrocycles, specifically cyclodextrins (CDs), have drawn considerable attention in this area owing to their ability to facilitate precise molecular separation with high liquid permeance for both polar and non-polar liquids, resembling Janus membranes. However, the functional role of the intrinsic cavity of CD in liquid transport remains inadequately understood, demanding immediate attention in designing nanofiltration membranes. Here, the synthesis of polyester nanofilms derived from crosslinked ß-CD, demonstrating remarkable Na2SO4 rejection (≈92 - 99.5%), high water permeance (≈4.4 - 37.4 Lm-2h-1bar-1), extremely low hexane permeance (<1 Lm-2h-1bar-1), and extremely high ratio (α > 500) of permeances for polar and non-polar liquids, is reported. Molecular simulations support the findings, indicating that neither the polar nor the non-polar liquids flow through the ß-CD cavity in the nanofilm. Instead, liquid transport predominantly occurs through the 2.2 nm hydrophilic aggregate pores. This challenges the presumed functional role of macrocyclic cavities in liquid transport and raises questions about the existence of the Janus structure in nanofiltration membranes produced from the macrocyclic monomers.

Are Hansen solubility parameters relevant in predicting the post-treatment effect on polyamide-based TFC membranes?

This study investigates the impact of solvent post-treatment on polyamide-based thin film composite (TFC) membranes, specifically examining the effect on commercial nanofiltration (NF) and reverse osmosis (RO) membranes. Na2SO4 rejection and increase in pure water permeance (PWP) were considered as the output parameters. The disparity in Hansen solubility parameters (HSP) between the post-treatment solution and the polyamide layer of the TFC membrane, denoted by Ra, is well adapted to understand the enhancement in water permeance through the membranes upon treatment. Aqueous solutions of dimethylformamide with a Ra value of 4, acetonitrile with a Ra value of 8.3, and ethanol with a Ra value of 12.7 were used as the post-treatment solutions. Our experimental design, based on the Box-Behnken design of Response Surface Methodology, incorporates variables such as the concentration of the solvent in the solution (% v/v), Ra value, and treatment time (s). Our findings demonstrate that the effect of post-treatment on the TFC membranes is not governed by the Ra value. Notably, while the post-treatment with the aqueous solution of acetonitrile, 80% v/v for 30 s, had considerable effects on NF membranes (124.5% enhancement in PWP; reduction of 3.5% in Na2SO4 rejection), its impact on RO membranes was negligible. Several factors explain this discrepancy, including the limitations of the HSP model for composite polymers, the inaccuracy of the PWP or salt rejection as a swelling indicator, variations in the HSP values of the polyamide layers for different membranes, and possible modifications in the interface between the support membrane and the polyamide layer. In summary, our study provides insights into the complex interactions between solvents and composite membranes, indicating that HSP alone is not a decisive factor in predicting post-treatment effects on polyamide-based TFC membranes.

Positioning of Low Alcohol or Alcohol-Free Minoxidil Formulation for the Management of Androgenetic Alopecia: Indian Perspective.

Topical minoxidil is used for treating different hair disorders. Even though it is an effective therapy, many patients show poor compliance due to the cost, side effects, and duration of treatment. Topical minoxidil is the mainstay treatment for androgenetic alopecia (AGA). Recently, low alcohol or alcohol-free topical minoxidil formulation has proven to be an alternative for patients suffering from AGA, including those with poor compliance with other therapies. Thus, the current article provides the positioning of low alcohol or alcohol-free topical minoxidil to manage AGA in Indian clinical practice.

Pseudofolliculitis corporis: a new entity diagnosed by dermoscopy.

Pseudofolliculitis mainly affects the beard area, but it can occur in any area of hair-bearing skin when traumatic methods like shaving or plucking are used to remove the hair. It can be a simple cosmetic problem or a disturbing medical condition for which the dermatologist must be prepared. It can develop in areas of shaving or depilation and has been seen in the pubic region or the axilla, where it is common to find curly hair that emerges at an acute angle. Here, we are reporting a case of pseudofolliculitis over back, termed as pseudofolliculitis corporis. He used to put a pillow behind the back while driving and the pressure caused the pseudofolliculitis. The diagnosis was confirmed by dermoscopy, which is a simple office procedure. Patient was advised to stop using the pillow and improved with topical adapalene and clindamycin gel for 15 days. This entity has not been described in the literature.