Tecnai g2 f20 s twin electron microscope

The fluorescence response and UV absorption behavior were observed using an LS55 luminescence spectrometer (Perkin-Elmer, Waltham, MA, USA) and UV–visible spectrophotometer (UV-2600, Shimadzu, Kyoto, Japan). The transmission electron microscopy (TEM) images of FW-CDs were obtained by a JEM-1200EX electron microscope with an accelerating voltage of 120 kV. Besides this, high-resolution TEM (HR-TEM) images were acquired through an FEI Tecnai G2 F20 S-Twin electron microscope. The chemical composition of the FW-CDs was analyzed by an ESCALAB 250Xi X-ray photoelectron spectrometer (XPS, Thermo Electron, Waltham, MA, USA). The Fourier transform infrared (FTIR) spectra were obtained using an FT-IR spectrophotometer (Shimadzu, Japan). The X-ray diffraction (XRD) results were obtained using a Bruker D8 ADVANCE diffractometer. Keeping the excitation wavelength at 375 nm, the fluorescence decay time was monitored using a luminescence spectrometer (FLS1000, Edinburgh, Livingston, UK). An Agilent 730 ICP-OES system was utilized to determine the Cr(VI) and Fe³⁺ concentrations in environmental water samples, iron supplements and industrial effluent.

Ultrastructural characterization of the cytological alterations was performed by a following a procedure that is detailed in previous publication. Briefly, lung tissue blocks (maximal 1 mm³) were immediately dissected after euthanasia, kept overnight at 4 °C in fixative (4% paraformaldehyde and 2.5% glutaraldehyde in 1xPBS; pH 7.4), and postfixed in 1% OsO₄ in the same buffer. After dehydration in graded ethanol the blocks were finally embedded in Spurr’s resin (Spurr Low Viscosity Embedding Kit; EMS ®). Semithin sections (0.5 μm thick) were cut with a glass knife on a Leica EM UC7 ultramicrotome and stained with toluidine blue. For TEM, ultrathin sections were cut on a Leica® Ultracut UC7 Ultramicrotome with a diamond knife. The sections were stained with uranyl acetate and lead citrate and examined with a FEI Tecnai G2 F20 S-TWIN Electron Microscope at 120 kV.

Transmission electron microscopy (TEM) was performed as previously described.^{18 (link)} Approximately 10 mL of cell culture was harvested by low-speed centrifugation (3 000g, 10 min), washed twice in 200 mmol̇L⁻¹ sodium cacodylate buffer, pre-fixed with 2.5 ġL⁻¹ glutaraldehyde and fixed with 10 ġL⁻¹ OsO₄. Samples were embedded in Epon resin, and thin sections (60 nm) were prepared using a microtome. The sections were stained with 40 ġL⁻¹ uranyl acetate and subsequently with 4 ġL⁻¹ lead citrate and were examined using a Tecnai G2 F20 S-TWIN electron microscope (FEI, Hillsboro, OR, USA).