Mohammad Ahmad

HNMR spectrum of compounds (I –III) Compound -I: HNMR (CDCl ; 400 MHz); the terminal methyl group (-CH ) present in the 4 4-butylaniline

On August 5, 2025, the U.S. Court of Appeals for the Seventh Circuit issued its decision in Richards v.

Department of Pharmaceutical Sciences, School of Pharmacy, Lebanese International University, Beirut P.O. Box 11-5020, Lebanon

This study presents the third-order nonlinear optical (NLO) properties of a natural dye derived from lawsonia Inermis, investigated using Z-scan with continuous-wave He–Ne laser at a wavelength of 632.8 nm. The natural dye exhibited self-defocusing nonlinear refractive index and reverse saturable absorption (RSA) based nonlinear absorption coefficient. The self-defocusing behavior arises from thermal nonlinearity, while the RSA effect is attributed to a higher excited-state absorption cross-section compared to the ground state. The nonlinear refractive index and nonlinear absorption coefficient of the natural dye are determined to be on the order of 10−8 cm2/W and 10−3 cm/W, respectively. The natural dye exhibited a substantial third-order NLO susceptibility (χ³), measured to be on the order of 10⁻⁷ esu. FT-IR analysis is employed to determine the functional groups present in the natural dye. Density functional theory (DFT) calculations corroborate the experimental findings by providing insights into the NLO properties, molecular electrostatic potential (MEP) and frontier molecular orbit (FMO) of the natural pigments. The results offer valuable insights into the natural dye extracted from lawsonia Inermis leaves, highlighting its potential for nonlinear optical applications.

Background: Zebrafish (Danio rerio) embryos are transparent in early stages of embryonic development; however, pigment formation at later stages hinders internal organ visualization during imaging. Chemicals such as 1-phenyl-2-thiourea (PTU) and kojic acid, used to block pigmentation, pose significant toxicity risks to human health. Therefore, effective and risk-free depigmentation agents are needed. This study investigates the efficacy of Alchemilla vulgaris (Lady’s mantle) as a safe, natural alternative for zebrafish embryo depigmentation. Methods: A. vulgaris was extracted using four solvents of varying polarities and evaluated for depigmentation efficacy and toxicity. Gas chromatography–mass spectrometry (GC–MS) was used to identify major constituents of the extract. Results: Ethyl acetate extract was more effective at removing pigments than all other extracts, and exhibited the lowest toxicity compared to PTU and kojic acid. Ethyl acetate extract of A. vulgaris remained effective even when administered 48 h post fertilization (post-pigmentation), making it suitable for long-term experiments requiring optical clarity. GC-MS revealed that this extract was rich in linoleic acid, various fatty acid esters, and phenolics, which likely contributed to its depigmentation activity. Conclusions: Based on these findings, we propose that ethyl acetate extract of A. vulgaris is a safer, natural alternative to PTU and kojic acid for depigmenting zebrafish embryos, particularly in long-term imaging experiments. The extract exhibits high efficacy at low concentrations, accompanied by a favorable toxicity profile, demonstrating potential as a depigmentation agent during early zebrafish development. However, further studies are needed to elucidate its mechanism of action.

The cybersecurity community went on alert when Anthropic announced on April 7, 2026, that its latest and most capable general-purpose large language

(MORGANTOWN, WV) The cybersecurity community went on alert when Anthropic announced on April 7, 2026, that its latest and most capable general-purpose

Typesetting math: 100% by and Mechanical Engineering Department, Yarmouk University, P.O. Box 566, Irbid 21163, Jordan