The quality of graphene intended for use in biosensors was assessed on manufactured chips using a set of methods including atomic force microscopy (AFM), Raman spectroscopy, and low-frequency noise investigation. It is shown that local areas of residues on the graphene surface, formed as a result of the interaction of graphene with a photoresist at the initial stage of chip development, led to a spread of chip resistance (R) in the range of 1-10 kOhm and to an increase in the root mean square (RMS) roughness up to 10 times, which can significantly worsen the reproducibility of the parameters of graphene chips for biosensor applications. It was observed that the control of the photoresist residues after photolithography (PLG) using AFM and subsequent additional cleaning reduced the spread of R values in chips to 1-1.
View Article and Find Full Text PDFPorous ferroelectric lead zirconate titanate (PZT) films are a promising material for various electronic applications. This study focuses on understanding how the structure-directing agent, polyvinylpyrrolidone, can alter the structure and electrical properties of porous PZT films prepared through chemical solution deposition. Films with various porosities of up to ~40 vol.
View Article and Find Full Text PDFIn this study, we discuss the mechanisms behind changes in the conductivity, low-frequency noise, and surface morphology of biosensor chips based on graphene films on SiC substrates during the main stages of the creation of biosensors for detecting influenza viruses. The formation of phenylamine groups and a change in graphene nano-arrangement during functionalization causes an increase in defectiveness and conductivity. Functionalization leads to the formation of large hexagonal honeycomb-like defects up to 500 nm, the concentration of which is affected by the number of bilayer or multilayer inclusions in graphene.
View Article and Find Full Text PDFBackground: Management of diabetes mellitus-induced erectile dysfunction (DMED) is challenging because of its insufficient responses to phosphodiesterase type 5 inhibitors.
Aim: To compare the effects of ipidacrine, a reversible cholinesterase inhibitor, and sildenafil on DMED in a rat model of streptozotocin (STZ)-induced diabetes.
Methods: Erectile dysfunction (ED) caused by STZ-induced diabetes mellitus was modeled in adult male Wistar rats, which were randomized to 4 groups: untreated diabetic rats, sildenafil (5 mg/kg), ipidacrine (3.
Zh Nevrol Psikhiatr Im S S Korsakova
November 2018
A clinical case of a young man with rapid bilateral visual impairment developed 2 months after the onset of generalized convulsive seizures is presented. The replacement of valproate to levetiracetam led to the remission of seizures, but the prognosis for vision remains poor, particularly given the pessimistic results of optical coherence tomography (OCT).
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