ZIF-67 grafted-boehmite-PVA composite membranes with enhanced removal efficiency towards Cr(VI) from aqueous solutions.

In this work, we developed a thin membrane of boehmite-polyvinyl alcohol composite (BOPOM) (diameter âˆ¼ 5 cm) grafted ZIF-67 combing sol-gel and in-situ growth methods. The fabricated materials were characterized using FT-IR, SEM, XRD, TGA, XPS, and N2 sorption techniques. Results indicate that ZIF-67 nanocrystals were well-grafted into the AlOOH-PVA matrix with reduced crystallite size. Furthermore, the decorated ZIF-67 offered additional porous structures and adsorption sites onto the membrane, enhancing their removal efficiency towards Cr6+ compared to the undecorated and pristine ZIF-67. At pH ∼5.5, the harvested ZIF-67/BOPOM exhibited the highest Cr6+ uptake capacity of ∼56.4 mg g-1. Kinetic studies showed that the chromium adsorption on the prepared materials obeyed the pseudo-second-order model, and the kinetic parameters followed the order ZIFF-67/BOPOM (0.020 mg g-1 min-1) > BOPOM (0.011 mg g-1 min-1) > ZIF-67 (0.006 mg g-1 min-1). Notably, the adsorption mechanism study revealed that adsorbed Cr6+ was reduced to Cr3+, and the reduction yield was boosted owing to grafting ZIF-67 into the BOPOM. In addition, the fabricated ZIF-67/BOPOM can simultaneously remove Cr6+ and methyl orange dye (MO) in the solution due to their synergetic effects on each other. Furthermore, the hybrid membrane ZIF-67/BOPOM showed a chromium removal efficiency of ∼78.2% after four successive adsorption-desorption cycles. This study indicates that grafting nanocrystals ZIF-67 onto the super-platform boehmite-PVA is a promising strategy to harvest an adsorbent with a high adsorption ability, cost-effectiveness, and reduced secondary pollution risks.

Green synthesis of zinc oxide nanoparticles toward highly efficient photocatalysis and antibacterial application.

Zinc oxide nanoparticles (ZnO NPs) were successfully synthesized by a green method using rosin and zinc chloride as salt precursors. The phase structure, morphology, and particle size of ZnO were determined by X-ray powder diffraction, field emission scanning electron microscopy, and high-resolution transmission electron microscopy. The fabricated ZnO NP samples are crystalline with a grain size of 30-100 nm. The ZnO NPs were used as catalysts for the photodegradation of methylene blue (MB) and methyl orange (MO) under visible and UV light. The results indicate that the prepared ZnO material excellently removed MB and MO (c initial = 10 mg/L) with efficiencies of 100% and 82.78%, respectively, after 210 min under UV radiation with a ZnO NP dose of 2 g/L. The photocatalyst activity of the synthesized material was also tested under visible light radiation with the same conditions; however, it achieved lower efficiencies. In addition, ZnO NPs were also tested regarding their antibacterial activity, and the results showed that the prepared ZnO samples had the highest (i.e., 100%) antibacterial efficiency against E. coli.

Synthesis and characterization of some novel polythiophene derivatives containing pyrazoline.

Eight polythiophene derivatives containing pyrazoline side groups were synthesized by a chemical oxidative coupling polymerization using FeCl3. The crystal structures of four monomers were determined which confirm the almost perpendicular orientation of the thiophene and pyrazoline rings, while the other substituents are more coplanar. Analyses of IR, 1H-NMR, Raman and UV-Vis spectra demonstrated that the suggested polymerization was successful to generate the synthesized polythiophenes with the expected structures. The morphology of the synthesized polythiophenes was studied by SEM. The different substituents attached to the 1- and 3-positions of the pyrazoline side chain led to differences in optical properties, electrical conductivity, and thermal stability of the synthesized polythiophenes. By adding a pyrazoline side chain to polythiophenes, some polymers achieve good solubility, electrical conductivity of about 1.3 × 10-6 S/cm, high fluorescence intensity (above 40,000 a.u.) at 505-550 nm and thermal stability up to 590°C in the air.

Determinants of variability of five programmed death ligand-1 immunohistochemistry assays in non-small cell lung cancer samples.

Programmed death ligand-1 (PD-L1) expression as determined by immunohistochemistry (IHC) is potentially predictive of clinical outcome. The aim of this study was to assess the concordance of reported PD-L1 IHC assays and investigate factors influencing variability. Consecutive sections from 20 non-small cell lung cancers (NSCLCs) comprising resection, core biopsy, cytology and pleural fluid samples underwent IHC with 5 different antibody/autostainer combinations: 22C3/Link48, 28-8/BOND-MAX, E1L3N/BOND-MAX, SP142/BenchMark and SP263/BenchMark. PD-L1 RNA levels were assessed using RNAscope. The frequency of positive cases using scoring thresholds from clinical trials was 72%, 33%, 61%, 56%, and 33% for the 5 IHC protocols respectively, and 33% for RNAscope. Pairwise agreement on the classification of cases as positive or negative for PD-L1 expression ranged from 61%-94%. On a continuous scale, the lowest correlation was between 28-8/BOND-MAX and SP142/BenchMark (R2=0.25) and highest was between 22C3/Link48 and E1L3N/BOND-MAX (R2=0.71). When cases were ordered according to tumor cell (TC)%, a similar ranking of cases across IHC protocols could be observed, albeit with different quanta and limits of detection. Single-slide OPAL 7-color fluorescence IHC analysis revealed a high degree of co-localization of staining from the 5 PD-L1 antibodies. Using SP142 antibody in a BOND-MAX protocol led to increased TC% quanta, while retaining a similar ranking of samples according to TC%. The results of this study highlight tumor PD-L1 status can vary significantly according to IHC protocol. Protocol-dependent staining intensities and nominated thresholds for positivity contribute to this variability, while the antibody used appears to be less of a factor.