Synthesis and Structural Investigation of Foldamer-Based Iodine-Supported Artificial Glycosidases

Glycosidases are a type of enzyme that hydrolytically cleave carbohydrates and form glycans for biologically important processes. The inadequacies of glycosidases or their genetic abnormalities are responsible for various diseases. Thus, the development of glycosidase mimetics is of great importance. We have designed and synthesized an enzyme mimetic containing l -phenylalanine, α-aminoisobutyric acid (Aib), l -leucine, and m-Nifedipine. From X-ray crystallography, the foldamer adopts a β-hairpin conformation stabilized by two 10-member and one 18-member NH⋅⋅⋅O=C hydrogen bonds. Moreover, the foldamer was found to be highly efficient in hydrolysing ethers and glycosides in the presence of iodine at room temperature. Further, X-ray analysis shows the backbone conformation of the enzyme mimetic to be almost unchanged after the glycosidase reaction. This is the first example of iodine-supported artificial glycosidase activity with an enzyme mimic at ambient conditions.     

Segmentation of breast lesion in DCE-MRI by multi-level thresholding using sine cosine algorithm with quasi opposition-based learning

Pattern Analysis and Applications - In recent times, the high prevalence of breast cancer in women has increased significantly. Breast cancer diagnosis and detection employing computerized...     

Boron and Sodium Doping of Polymeric Carbon Nitride Photoanodes for Photoelectrochemical Water Splitting

Polymeric carbon nitride is a promising photoanode material for water-splitting and organic transformation-based photochemical cells. Despite achieving significant progress in performance, these materials still exhibit low photoactivity compared to inorganic photoanodic materials because of a moderate visible light response, poor charge separation, and slow oxidation kinetics. Here, the synthesis of a sodium- and boron-doped carbon nitride layer with excellent activity as a photoanode in a water-splitting photoelectrochemical cell is reported. The new synthesis consists of the direct growth of carbon nitride (CN) monomers from a hot precursor solution, enabling control over the monomer-to-dopant ratio, thus determining the final CN properties. The introduction of Na and B as dopants results in a dense CN layer with a packed morphology, better charge separation thanks to the in situ formation of an electron density gradient, and an extended visible light response up to 550 nm. The optimized photoanode exhibits state-of-the-art performance: photocurrent densities with and without a hole scavenger of about 1.5 and 0.9 mA cm⁻² at 1.23 V versus reversible hydrogen electrode (RHE), and maximal external quantum efficiencies of 56% and 24%, respectively, alongside an onset potential of 0.3 V.     

Host-Assisted Delivery of a Model Drug to Genomic DNA: Key Information from Ultrafast Spectroscopy and in silico Study

Drug delivery to a target without adverse effects is one of the major criteria for clinical use. Herein, we have made an attempt to explore the delivery efficacy of SDS surfactant in a monomer and micellar stage during the delivery of the model drug, Toluidine Blue (TB) from the micellar cavity to DNA. Molecular recognition of pre-micellar SDS encapsulated TB with DNA occurs at a rate constant of k₁ ∼652 s⁻¹. However, no significant release of encapsulated TB at micellar concentration was observed within the experimental time frame. This originated from the higher binding affinity of TB towards the nano-cavity of SDS at micellar concentration which does not allow the delivery of TB from the nano-cavity of SDS micelles to DNA. Thus, molecular recognition controls the extent of DNA recognition by TB which in turn modulates the rate of delivery of TB from SDS in a concentration-dependent manner.     

Numerical Investigation of the Radial Ore-to-Coke Ratio in the Blast Furnace Throat during Nonuniform Burden Descent

The burden descent in the blast furnace throat affects the radial ore-to-coke ratio, which is directly related to the gas distribution and chemical reactions in the furnace. Herein, the layer structure and the radial ore-to-coke ratio of the burden bed under uniform and nonuniform burden descent are studied numerically by the discrete element method. Two kinds of nonuniform descent are considered, where the descent rate in the furnace center is greater than the descent rate at the wall or vice versa. The descent is realized by deleting particles in virtual boxes of different sizes at the lower end of the simulated domain. The results show that the ore-to-coke ratio decreases where the descent rate is low and increases where the descent rate is high. For a burden profile of the “platform + hopper” type, a faster burden descent in the center has a much stronger influence on the radial ore-to-coke ratio distribution than the case with faster descent at the wall. The size difference between the ore and coke particles and the charging matrix are also found to play a role in the influence of the burden descent on the distribution of the ore-to-coke ratio.     

Secure access privilege delegation using attribute-based encryption

International Journal of Information Security - Attribute-based encryption (ABE) is widely used for a secure and efficient data sharing. The predetermined access policy of ABE shares the data with...     

Additive‐additive interactions: The search for synergistic antioxidant—antiwear phosphorodithioate compositions

Additive‐additive interactions between zinc dialkylphosphorodithioates and ashless alkylaminophosphorodithioates have been studied with the object of reducing the zinc level in the lubricant formulations. Various combinations of these components were evaluated for their antiwear and antioxidant properties using four‐ball and differential scanning calorimetry techniques.     

Electro-kinetically enhanced mass transport of charged macro-solutes through a microchannel with porous walls

Electrokinetics of the solute transport across the porous walls of micro channel is important from its practical application but less explored. Transport of the charged macro-solutes across perm-selective walls in a microchannel is investigated. The extended Nernst–Planck equation describes the charged macro-solutes distribution in the mass transfer boundary layer over the porous wall. The transverse electromigration of the charged macro-solute either augments or suppresses the concentration polarization and the permeation rate depending on the wall and solute surface potential (attractive or repelling). The wall potential is screened due to the electrical double layer interaction of the wall and charged solute. It is observed that the charged solute concentration over the channel wall enhances by two times in case of oppositely charged interactions (unlike solute and channel wall) compared to like charges. The findings of this study can facilitate understanding of electrokinetic based drug delivery and separation systems involving charged solutes.     

Interaction of a Jaundice Marker Molecule with a Redox-Modulatory Nano-Hybrid: A Combined Electrochemical and Spectroscopic Study toward the Development of a Theranostic Tool

This study explores a combined electrochemical and spectroscopic approach to investigate the degradation of bilirubin, a molecular marker of jaundice in humans using a biocompatible nanohybrid (citrate-functionalized Mn₃O₄ nanohybrid; C−Mn₃O₄ NH). The approach is aimed at the development of a facile theranostic tool for treatment, detection, and prognosis of jaundice. Linear sweep voltammetry (LSV) studies on bilirubin, C−Mn₃O₄ NH, a model carrier protein, and its complex with bilirubin reveal the efficacy of the nanohybrid for both degradation and detection of bilirubin. Furthermore, spectroscopic studies depict that distal electron transfer to be the probable mechanism behind the observed bilirubin degradation in physiological milieu.     

Froth flotation as primary treatment of flowback water: Removal of total organic carbon and prediction of kinetics

Petroleum and exploration industries employ a hydrofracking process where a large volume of water (fracturing fluid) is injected and a fraction (known as flowback water) is returned to the surface. Froth flotation is a typical process employed for the primary treatment of water. In the present work, froth flotation has been used as a pretreatment method for real flowback water sourced from the petroleum and shale gas exploration industry. In the present work, a first-principle based convective mass transfer model has been developed to describe the froth flotation performance. The resultant equation was solved analytically and compared with the numerical solution, and a parametric sensitivity analysis of the process performance was also undertaken. In addition, a correlation to estimate the flotation rate constant was proposed, thereby circumventing the need to obtain a large number of cumbersome parameters experimentally. Overall, this study proposes froth flotation as an efficient primary treatment method towards the separation of dispersed oil droplets from the flowback water and the corresponding prediction of kinetics using a first-principle based transport model.