ABSTRACT
Commercially available graphene samples are examined by Raman spectroscopy and very low energy scanning transmission electron microscopy. Limited lateral resolution of Raman spectroscopy may produce a Raman spectrum corresponding to a single graphene layer even for flakes that can be identified by very low energy electron microscopy as an aggregate of smaller flakes of various thicknesses. In addition to diagnostics of graphene samples at larger dimensions, their electron transmittance can also be measured at very low energies.
ABSTRACT
UNLABELLED: Aim of this case report to present a case a male patient with age related macular degeneration succesfully treated by anti-VEGF substances different types. The autor presents a case of 83 year old male with active choroidal neovasculare membrane. In this patient, the best corrected visual acuity (BCVA) of the left eye was 4/10 and the central retina thickness of the left eye was 320 microm. Activity of neovascular membrane was verified by OCT and FAG. Treatment was started with anti-VEGF Macugen. After 2 intravitreal injections of Macugen was state of retina worse. Treatment of the left eye was terminated according to recommendation in Information about drug Macugen. After that was started intravitreal applications of Lucentis. The state of retina was stabilizated after four injections of Lucentis. BCVA of the left eye was 4/20 and the central retina thickness was 130 microm. It happend after one year from beginning of therapy. CONCLUSIONS: Dosing of anti-VEGF substances results from clinical trials is suitable for treatment majority of patients with choroidal neovascular membrane. Change of anti-VEGF substance is necessary for stabilisation of state on retina in some cases.
Subject(s)
Antibodies, Monoclonal/administration & dosage , Aptamers, Nucleotide/administration & dosage , Choroidal Neovascularization/drug therapy , Macular Degeneration/drug therapy , Vascular Endothelial Growth Factors/antagonists & inhibitors , Aged, 80 and over , Antibodies, Monoclonal, Humanized , Choroidal Neovascularization/complications , Choroidal Neovascularization/pathology , Drug Substitution , Fluorescein Angiography , Humans , Intravitreal Injections , Macular Degeneration/complications , Macular Degeneration/pathology , Male , Ranibizumab , Tomography, Optical CoherenceABSTRACT
Differently doped areas in silicon can show strong electron-optical contrast in dependence on the dopant concentration and surface conditions. Photoemission electron microscopy is a powerful surface-sensitive technique suitable for fast imaging of doping-induced contrast in semiconductors. We report on the observation of Si (100) samples with n- and p-type doped patterns (with the dopant concentration varied from 10(16) to 10(19) cm(-3)) on a p- and n-type substrate (doped to 10(15) cm(-3)), respectively. A high-pass energy filter of the entire image enabled us to obtain spectroscopic information, i.e. quantified photo threshold and related photoyield differences depending on the doping level. Measurements have confirmed the possibility of resolving areas at a high contrast even with the lowest dopant concentration when employing the energy filter. The influence of electron absorption phenomena on contrast formation is discussed.
