Jsm 6510lv

A scanning electron microscope (SEM) (JEOL JSM 6510 lv, JEOL, Pleasanton, CA, USA) equipped with an EDAX micro-analytical system was used to determine the elemental composition of the analyzed nanometals. Thin films of nanometals were formed on glass cover slips by spreading the nanometals, and the samples were then coated with gold-palladium membranes and observed using a Jeol JSM-6510 L.V SEM (Pleasanton, CA, USA) at an accelerating voltage of 30 KV.

The culture was treated with 10% hydrochloric acid to remove carbonates and washed several times with deionized water for 12 h. Afterwards, the sample was boiled in concentrated hydrogen peroxide (≈ 37%) to remove organic matter. It was washed again with deionized water four times at 12 h intervals. After decanting and filling with deionized water up to 100 ml, the suspension was pipetted onto coverslips and left to dry at room temperature. Permanent diatom preparations were mounted in Naphrax. Light microscopic (LM) observations were performed with a Zeiss Axio Scope A1 microscope equipped with an oil immersion objective (× 100, n.a. 1.4, differential interference contrast [DIC]) and Axiocam ERc 5s camera (Zeiss). Valve ultrastructure was examined by means of scanning electron microscopes JEOL JSM-6510LV (JEOL Ltd., Japan) operating at 15 kV and 8 mm of working distance (IBIW, Institute for Biology of Inland Waters RAS, Borok, Russia). For scanning electron microscopy (SEM), part of the suspensions was fixed on aluminum stubs after air-drying. The stubs were sputter-coated with 50 nm of Au by means of a Eiko IB 3 (Eiko Engineering, Japan).
The cleaned material, sample and slide are deposited in the collection of MHA, Main Botanical Garden Russian Academy of Science, Moscow, Russia. The type slide was designated B209.

To analyze the morphology of trophozoites after the lignans or DMSO treatment, parasites were washed with PBS, fixed with 2.5% glutaraldehyde (Sigma-Aldrich, Saint Louis, MO, USA) in PBS for 1 h, and adhered to 0.1% poly-(ethylenimine) (Sigma-Aldrich, Saint Louis, MO, USA)-coated cover slips. After that, they were fixed in 2% osmium tetroxide (Electron Microscopy Science, Hatfield, PA, USA) for 2 h. Next, cells were washed with PBS, dehydrated in an ascending ethanol serial, subjected to critical-point drying with CO₂ (Tousimis, Rockville, MD, USA), mounted on stainless steel holders, sputter-coated with a thin layer of gold, and analyzed by SEM (JEOL-JSM6510LV, Tokyo, Japan).

Sub-MICs of IONPs were used to treat bacterial cells (P. aeruginosa and L. monocytogenes). Glass coverslips placed in wells of the microtitre plate were inoculated with overnight grown test pathogens and incubated for 24 h at 30°C. IONP treated and untreated coverslips were washed with sterile PBS to remove unadhered cells. All samples were fixed with 2% formaldehyde and 2.5% glutaraldehyde. Fixed coverslips were washed thrice with PBS and subjected to ethanol drying. Completely dried coverslips were gold coated and visualized under scanning electron microscope (SEM, JEOL-JSM 6510 LV, Japan).