The degree of monomer conversion (DC) values of three different dental composites were examined using three different methods: surface microhardness (ratio of bottom/top), Fourier-transform infrared (FT-IR), and differential scanning calorimetry (DSC). Two of the dental composites included in the study were nanohybrid (Dentsply Neo Spectra ST HV and Omnichroma), and one was a microhybrid-labeled newly marketed composite containing nanoparticles (Dentac Myra). Composite discs were prepared according to the methodology for all methods and analyzed (2 mm thickness × 5 mm diameter). Surface microhardness values were measured in Vickers Hardness Number (VHN), while FT-IR and DSC values were obtained in percentage (%). Significant differences were observed in both bottom/top surface microhardness values and DC values obtained from FT-IR. However, there was no statistical difference in the ratio of bottom/top microhardness values. Neo Spectra ST HV exhibited superior performance in both microhardness and monomer conversion compared to the other two composites. Newly marketed Myra showed values close to Omnichroma. It was found that the values obtained by the DSC method were parallel to those obtained by FT-IR. In conclusion, the structure of dental composites leads to different mechanical properties. Additionally, DSC measurements and FTIR spectra were found to be complementary techniques for characterizing monomer conversion values.
12 June 2023 in Fabad Journal of Pharmaceutical Sciences
Within the last two or three decades the treatment of the neurodegenerative disorders became became the main focus of the researches. In this, our aim was to determine some biological activities of the ethanolic and methanolic extracts of Salvia sclarea L. After obtaining the extracts, first they have been tested for their DPPH radical scavenging activity and then the total phenolic contents of the extracts have been identified. Afterwords, the extracts were evaluated for both their effects on acetylcholinesterase (AChE) and monoamine oxidase-A. These two enzymes are very important enyzmes for their importance in the treatment of neurodegenerative disorders. AChE plays a very crucial role especially in Alzheimer’s Disease. Monoamine oxidases and their inhibitors have also critical value in Alzheimer type dementia and in other neurologic diseases. It has been found that DPPH activity of the methanolic extract was higher than that of ethanolic extracts; while TPC was higher for the ethanolic extract. IC50 values were found for both AChE and MAO-A. For AChE the IC50 values for ethanolic extract and methanolic extract were, 0,27±0,005 mg/mL and 1,19±0,037 mg/mL; respectively. And for MAO-A the IC50 values for ethanolic extract and methanolic extract were 6,53±0,72 microgramg/mL and 3,03±0,05 microgram/mL; respectively.
27 May 2022 in Journal of Cancer Research and Clinical Oncology
The essential oil composition of aerial parts of Ruta chalepensis L. was analyzed with GC-MS. Seventy-nine compounds were detected representing 85.93 ± 1.08% (n = 3) of the essential oil. The major components of the essential oil were 2-undecanone 21.52 ± 0.21%, 2-nonanone 18.31 ± 0.27%, and 2-nonyl acetate 13.22%. The highest insecticidal contact toxicity of the oil was observed against Rhyzopertha dominica F. with 0.018 μl/insect LD50 and 0.039 μl/insect LD90 after 24h. Essential oil also produced considerably low 0.50 and 0.59 μl/insect LD50 values after 24h against Sitophilus oryzae L. and Sitophilus granarius L. respectively. The lowest contact toxicity was observed against Tribolium castaneum Herbst. and Tribolium confusum Jacquelin du Val. 0.138 and 0.078 μl/insect LD50 after 24h respectively. The highest fumigant toxicity was observed against S. granarius for the application concentration of 10 μl, 10% oil/acetone (v:v) in a 10 ml chamber which afforded 100.00 ± 0.00% mortality after 48h. The essential oil also produced high fumigant toxicity against S. oryzae, T. castaneum and R. dominica which were 95.47 ± 3.41%, 93.30 ± 5.54%, and 85.47 ± 3.41% mortality at 20 μl application concentration of the oil solution after 48h. The R. chalepensis essential oil produced low acetylcholinesterase enzyme 5.29 ± 1.20% (n=3) inhibition and mediocre butyrylcholinesterase enzyme inhibition 42.6 ± 0.71% (n=3). According to the insecticidal activity assays performed, the essential oil R. chalepensis seems to be a promising source that could yield natural compounds that could be employed in stored product pest management.
Investigating alternatives to synthetic chemicals in pest management is essential. The bioactivity of Artemisia absinthium and A. dracunculus essential oils (EOs) was evaluated against two stored-product insect pests (Sitophilus granaries and Tribolium castaneum) and two root-knot nematodes (Meloidogyne incognita and M. chitwoodi). EOs were hydrodistilled and analyzed by GC-MS: A. absinthium consisted mainly of myrtenyl acetate (47.10%) and β-thujone (11.41%); A. dracunculus of methyleugenol (26.02%), β-asarone (14.04%), and elemicin (10.95%). In contact bioassays, A. absinthium caused 93.2–96.8% mortality against S. granarius, but minimal effect on T. castaneum. A. dracunculus caused 66.3–73.5% mortality against S. granarius, no effect on T. castaneum, yet reduced progeny by 87%. Both EOs strongly repelled T. castaneum but weakly affected S. granarius. A. dracunculus exhibited 100% nematicidal efficacy against M. incognita and 94.9% against M. chitwoodi; A. absinthium showed limited effect. A. dracunculus showed minimal hatching inhibition (<30%), whereas A. absinthium increased hatching. Sparse Partial Least Squares (sPLS) prioritized pulegone, methyleugenol, β-asarone, β-thujone, myrtenyl acetate, and β-phellandrene as constituents co-varying with AChE/BChE responses, with docking identifying pulegone as the top ligand. These findings demonstrate species-specific bioactivity patterns: A. dracunculus shows strong nematicidal and reproductive inhibitory effects, whereas A. absinthium shows potent acute toxicity and repellency against S. granarius, supporting multi-target biopesticide strategies to mitigate risks of synthetic chemical treatments.