Search

Antibiotics are frequently used as growth boosters in animal husbandry. Tetracyclines (TCNs) are among the most widely used antibiotics compared to others, leaving traces in animal‐based foodstuffs like milk and meat. Thus, monitoring of TCNs is paramount, especially in the feedstuff. In the present study, a green method is developed to synthesize magnetic Ag/GO‐Fe3O4 nanocomposites using Azadirachta indica leaf extract. The synthesized adsorbent (Ag/GO‐Fe3O4) was analyzed for the residual extraction of oxytetracycline (OTC) and chlortetracycline (CTC) from the fresh milk samples through the magnetic solid‐phase extraction principle. The extraction procedure involved the deproteinization of milk, spiking with antibiotics, followed by magnetic solid‐phase extraction and quantification of TCNs by HPLC with a UV detector. Different factors that affected the adsorption capacity of the adsorbent for the TCNs like pH, temperature, amount of nanocomposite, and time were studied. The inter‐day and intra‐day precision were calculated for OTC (4% and 6%) and CTC (3% and 4%), respectively. The limit of detection and quantification for OTC was 0.5 and 1.5 μgL−1 and for CTC was 0.2 and 0.6 μgL−1 respectively while the percentage extraction was 94%–96%. [ABSTRACT FROM AUTHOR]

Direct hydrazine fuel cells (DHFC) insist on the evolved and persistent electrocatalysts for anodic hydrazine oxidation reaction (HzOR). Herein, PdO promoted CuO heterostructures supported on γ‐Al2O3 are depicted as efficient electrocatalysts for HzOR. γ‐Al2O3 is prepared by precipitation method while metal precursors are incorporated by co‐impregnation technique. Physiochemically characterized PdO‐CuO/Al2O3 mesoporous composites displayed large electrochemical active surface area (ECSA) i. e., 0.18 cm2, high current density (j) i. e., 35.7 mA cm−2, larger diffusion coefficient (D°) i. e., 29.3×10−4 (cm2s−1), large apparent rate constant (kapp) i. e., 13.2 cm−1 with low charge transfer resistance (Rct) i. e., 3.6 kΩ shown by the best catalyst i. e., 1 % PdO‐CuO/Al2O3. Cyclic voltammetry indicated that the fabricated working electrodes offer high efficiency towards HzOR in alkaline medium in such a way that 1 % PdO‐CuO/Al2O3 produced 600 times higher oxidation current than CuO/Al2O3 composite. Owing to stability and reproducibility, PdO modified CuO/Al2O3 would achieve a huge catalytic significance in multiple electrochemical oxidation reactions with economic and ecological benefits. [ABSTRACT FROM AUTHOR]

Covalent Organic Frameworks (COFs) represents a class of remarkable porous materials composed of organic building blocks that are covalently linked in a periodic manner to form crystalline structures. High surface area, high porosity, tunable pore size, and high stability are their exceptional properties, which make them attractive candidates for various applications in the fields of catalysis, energy storage devices, biomedical applications, gas separation and storage applications. In fact, the great interest shown in COFs gave us a stimulus to review the output of the recent substantial efforts in this area. Meanwhile, the development of portable and sophisticated systems based on these particles is believed to create deeper insights for the scientists to embark on new investigations to pave the way for discovering new fundamental characteristics of COFs, modifications. Furthermore, the effect of modifications/fractionalizations on the performance of COFs will be thoroughly explained and challenging problems are mentioned. Moreover, the paper covers an inclusive collection of referenced recent research articles, providing readers with a comprehensive understanding of the subject matter and an extensive bibliography for further exploration. Through this comprehensive overview, the paper alleviates the noteworthy contributions of COFs in driving innovation and progress in a range of key scientific disciplines. [ABSTRACT FROM AUTHOR]

A new hydrazide derivative N'-(2,4-dinitrophenyi)-2-fluorobenzohydrazide was synthesized and characterized by NMR and IR spectroscopy. The molecular structure was also studied by X-ray diffraction, and the results of the optimized molecular structure are presented and compared with density functional methods with 631-G basis set. The calculated results show that the optimized geometry can well reproduce the crystal structural parameters, for example, bond lengths and angles show good agreement with the experimental data. [ABSTRACT FROM AUTHOR]

In the title compound, C(13)H(10)N(4)O(5), the aromatic ring planes are close to perpendicular [dihedral angle = 75.94 (5)°] and the C-N-N-C torsion angle is 88.7 (2)°. Both nitro groups lie close to their attached ring plane, with C-C-N-O torsion angles of 3.1 (2) and 5.3 (2)°. This allows for the formation of an intra-molecular N-H⋯O hydrogen bond, which closes an S(6) ring. In the crystal, N-H⋯O hydrogen bonds link the mol-ecules into zigzag chains extending along [100].