Surgery for glaucoma in modern corneal graft procedures

Glaucoma is a common cause of vision loss after corneal transplantion and is considered a major risk factor for graft failure. Glaucoma may be present before corneal transplant surgery, or increased intraocular pressure may develop after keratoplasty in up to one-third of patients. Pre-existing glaucoma should be controlled before keratoplasty, either medically or surgically. For postkeratoplasty increase in intraocular pressure; identifying the risk factors allows appropiate follow-up and management. Patients undergoing anterior lamellar keratoplasty may take advantage of reduced rates of postkeratoplasty glaucoma. Glaucoma also complicates eyes with endothelial keratoplasties, mostly related to management of intraocular pressure spikes derived from anterior chamber air bubbles. Nevertheless, the severity is less, and the intraocular pressure is more easily controlled when compared with penetrating keratoplasty. Adequate management of glaucoma that develops before or after keratoplasty may save eyes from irreversible damage to the optic nerve and increase graft survival.     

Post-remission retinal microvascular and choroidal thickness changes in eyes with Behḉet’s disease posterior uveitis: an OCTA longitudinal study

International Ophthalmology - To investigate the retinal microvascular and choroidal thickness changes in eyes with active Beh?et’s disease posterior uveitis and post-remission. A...     

A dopamine electrochemical sensor based on a platinum–silver graphene nanocomposite modified electrode

A platinum–silver graphene (Pt–Ag/Gr) nanocomposite modified electrode was fabricated for the electrochemical detection of dopamine (DA). Electrochemical studies of the Pt–Ag/Gr nanocomposite towards DA detection were performed by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The CV analysis showed that Pt–Ag/Gr/GCE had enhanced electrocatalytic activity towards DA oxidation due to the synergistic effects between the platinum–silver nanoparticles and graphene. The DPV results showed that the modified sensor demonstrated a linear concentration range between 0.1 and 60 μM with a limit of detection of 0.012 μM. The Pt–Ag/Gr/GCE presented satisfactory results for reproducibility, stability and selectivity. The prepared sensor also showed acceptable recoveries for a real sample study.

A platinum–silver graphene nanocomposite was synthesized and characterized. A nanocomposite modified electrode was fabricated in order to investigate the electrochemical detection of dopamine.     

Sulfamic acid incorporated HKUST-1: a highly active catalyst and efficient adsorbent

Herein we introduce an effective approach for incorporating sulfamic acid (SA) into HKUST-1. The synthesized materials have been characterized using XRD, XPS, BET, FT-IR, SEM, EDX and TEM. The X-ray diffraction pattern of SA@HKUST-1 is analogous to that of parent HKUST-1 in line shape and d-spacing, proving that chemical modification could be obtained without damage to structural solidity. The XPS spectra confirmed successful sulfonation, due to the single S 2p peak being attributable to SO₃H groups at 168 eV. Catalytic efficiency was studied for 7-hydroxy-4-methyl coumarin and 3,4-dihydropyrimidinone synthesis and it was found to be highly dependent on the amount of SA loaded over HKUST-1. Moreover, the adsorptive removal activity of some common organic and inorganic pollutants from water has been studied. To fully understand the adsorption process, the effects of initial dye concentration, pH of solution, adsorbent dosage, contact time and temperature on the adsorption process were successfully studied. Under the optimum conditions 10 wt% SA@HKUST-1 was able to reach the maximum adsorption capacity for Pb²⁺ (298 mg g⁻¹) and Malachite green (290 mg g⁻¹). Hopefully, this will facilitate research on improving the prospective use of MOFs for future applications.

Herein we introduce an effective approach for incorporating sulfamic acid (SA) into HKUST-1.     

Critical review on the chemical reduction of nitroaniline

Conversion of nitroaniline (NA), a highly toxic pollutant that has been released into aquatic systems due to unmanaged industrial development in recent years, into the less harmful or a useful counterpart is the need of the hour. Various methods for its conversion and removal have been explored. Owing to its nominal features of advanced effectiveness, the chemical reduction of 4-NA using various different nanocatalytic systems is one such approach that has attracted tremendous interest over the past few years. The academic literature has been confined to case studies involving silver (Ag) and gold (Au) nanoparticles, as these are the two most widely used materials for the synthesis of nanocatalytic assemblies. Focus has also been given to sodium borohydride (NaBH₄), which is used as a reductant during the chemical reduction of NA. This systematic review summarizes the fundamentals associated with the catalytic degradation of 4-NA, and presents a comprehensive and critical study of the latest modifications used in the synthesis of these catalytic systems. In addition, the kinetics, mechanisms, thermodynamics, as well as the future directions required for understanding this model reaction, have been provided in this particular study.

Schematic illustration of catalytic reduction of 4-NA in the presence of nanocatalysts and a reducing agent.     

Discovery of 4-(2-(dimethylamino)ethoxy)benzohydrazide derivatives as prospective microtubule affinity regulating kinase 4 inhibitors

Microtubule affinity regulating kinase 4 (MARK4) is a Ser/Thr kinase, considered as a potential drug target for cancer, diabetes and neurodegenerative diseases. Due to its significant role in the development and progression of cancer, different in-house libraries of synthesized small molecules were screened to identify potential MARK4 inhibitors. A small library of hydrazone compounds showed a considerable binding affinity to MARK4. The selected compounds were further scrutinized using an enzyme inhibition assay and finally two hydrazone derivatives (H4 and H19) were selected that show excellent inhibition (nM range). These compounds have a strong binding affinity for MARK4 and moderate binding with human serum albumin. Anticancer studies were performed on MCF-7 and A549 cells, suggesting H4 and H19 selectively inhibit the growth of cancer cells. The IC₅₀ value of compound H4 and H19 was found to be 27.39 μM and 34.37 μM for MCF-7 cells, while for A549 cells it was 45.24 μM and 61.50 μM, respectively. These compounds inhibited the colonogenic potential of cancer cells and induced apoptosis. Overall findings reflect that hydrazones/hydrazone derivatives could be exploited as potential lead molecules for developing effective anticancer therapies via targeting MARK4.

Inhibition studies of MARK4 with selected hydrazone derivatives.     

Chemisorption and sustained release of cefotaxime between a layered double hydroxide and polyvinyl alcohol nanofibers for enhanced efficacy against second degree burn wound infection

Zn–Al layered double hydroxides (LDHs) were synthesized by a chemical method, while polyvinyl alcohol (PVA) nanofibers were fabricated by an electrospinning approach; we also synthesized Zn–Al LDH/cefotaxime (cefotax), Zn–Al LDH@PVA, and Zn–Al LDH/cefotax@PVA (LCP). Characterizations were performed by X-ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, high-resolution transmission electron microscopy, energy dispersive X-ray spectroscopy, Brunauer–Emmett–Teller analysis, thermogravimetric-differential thermal analysis techniques, dynamic light scattering, X ray-florescence, and carbon, hydrogen, and nitrogen (CHN) analyses. The adsorption isotherm of cefotax and its entrapment percentage, release, and kinetics were also investigated. The results confirmed the elemental constituents of the mentioned formulas, which exhibited different degrees of crystallinity and different morphologies. Besides, these formulas were tested in vitro as antimicrobial agents and applied in vivo against second-degree wound burns induced in rats'' skin. The adsorption of cefotax occurred chemically, and the experimental data were fitted with different isotherm models, where the Freundlich and Toth models gave the best fits. The entrapment percentage in LDH/cefotax was 77.41% and in LDH/cefotax@PVA, it was 67.83%. The sustained release of cefotax from LDH and LCP was attainable; the release percentages were 89.31% and 81.55% in up to 12 h, respectively. The release kinetics of cefotax from LDH fitted well with first-order kinetics, while that for LCP was parabolic. The formulas showed uneven antimicrobial effects against Gram-positive and Gram-negative bacteria; the best effect was exhibited by Zn–Al LDH/cefotax@PVA due to its sustained release. Finally, investigating the possibility of using these formulas in the clinical setting should be considered.

This study succeeded to formulate, characterize, and investigate cefotax release and kinetics, and to compare cetofax with other known antibacterial agents.