Atomic layer deposition (ALD) is a technique capable of producing ultrathin conformal films with atomic level control over thickness. A major drawback of ALD is its low deposition rate, making ALD less attractive for applications that require high throughput processing. An approach to overcome this drawback is spatial ALD, i.e., an ALD mode where the half-reactions are separated spatially instead of through the use of purge steps. This allows for high deposition rate and high throughput ALD without compromising the typical ALD assets. This paper gives a perspective of past and current developments in spatial ALD. The technology is discussed and the main players are identified. Furthermore, this overview highlights current as well as new applications for spatial ALD, with a focus on photovoltaics and flexible electronics.
A dc voltage changed periodically with magnetic field is observed on segments of asymmetric aluminum loop without any external dc current at temperatures corresponded to superconducting transition. According to this experimental result a segment of the loop is a dc power source. A possibility of a persistent voltage on segments of an inhomogeneous normal metal mesoscopic loop follows from this result.
Almost constant voltage plateaus on the V (I) curves of long quasi-one-dimensional superconducting aluminum wires placed in magnetic field at temperatures T slightly below the critical superconducting temperature Tc were found which were unexpected for the sample geometry and parameters of the experiment. The plateaus are assumed to be subharmonics of a superconducting gap and arise due to the multiple Andreev reflection and strong quasiparticle overheating in the wire nonequilibrium region. The plateaus are evidence of coexistence of superconductivity and dissipation in such wires. The results presented in the paper could not be described by existing theories.
Aim: The work aimed to study the morphology of colonies and their comparison by features of the formation of Yersinia enterocolitica biofilms.
Materials and Methods: Bacteria were cultured on a Yersinia Selective Agar medium ("CIN-agar") at 28°C for 24 h. The microorganisms were grown in meat-peptone broth with 1.0% glucose to measure the absolute values of the optical density of the culture. The optical density of the liquid was determined in a microplate photometric analyzer Immunochem-2100 (HTI, USA) at a wavelength of 490 nm. For the study of biofilms, the specimens were fixed for 3-5 h in pairs of 25.0% solution of glutaraldehyde (according to DV), and pairs of a 1.0% aqueous solution of osmic acid (OSO4) were used for contrasting for 2-3 min. The specimens were examined with stereoscopic microscopy "BIOMED MS-1 Stereo" (Russia) and scanning electron microscope "TM 3030 plus" (Holland).
Results: With stereoscopic microscopy of the colonies of Y. enterocolitica, the S-forms had an elevated intensely colored center, radial striation along the periphery, smooth edges, d ≤ 1.0 mm. R-form colonies had a dark color and a dry surface, were tuberous and had a dense center with a peripheral ridge, rugged edges, d ≥ 1.5 mm. The optical density of the Y. enterocolitica S-form showed that this type of microorganism belongs to the moderate producers of biofilms since the optical density of the sample (density of the sample - Ds) exceeded the optical density of control (density of the control - Dc) by 3 times. In Y. enterocolitica R-form (D ≤ 0.197) weakly produced biofilms, the optical density of the sample exceeded the optical density of the control by <2 times.
Conclusion: The ability to form biofilms, the variability of phenotypic features, and the multiplicity of virulence factors of bacteria significantly reduce the effectiveness of diagnostic studies. The development of accelerated methods of detection and differentiation of the virulent properties of pathogenic bacteria will allow scientifically to substantiate and develop a set of measures aimed at preventing animal diseases and obtaining safe livestock products to prevent human diseases. Thus, we need to pay attention to which forms of colonies do Y. enterocolitica form on solid nutrient media: S- or R-forms. Through this study, we know that bacteria-forming S-shaped colonies are more capable of forming biofilms than R-forms. It means that they are more pathogenic and can cause persistent infections due to adhesion and biofilm formation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.