Mass spectra of N-arylaminosulphonylcarbethoxydiazoacetamides

The electron impact mass spectra of N-arylaminosulphonylcarbethoxydiazoacetamides were studied. On the basis of high-resolution mass spectrometric data, mass-analysed ion kinetic energy Spectrometry and linked scan experiments a detailed scheme of the fragmentation is proposed. A number of possibilities of charge Iocalization are revealed in the complex decomposition processes of the molecular ions.     

First-passage Monte Carlo algorithm: diffusion without all the hops

We present a novel Monte Carlo algorithm for N diffusing finite particles that react on collisions. Using the theory of first-passage processes and time dependent Green's functions, we break the difficult N-body problem into independent single- and two-body propagations circumventing numerous diffusion hops used in standard Monte Carlo simulations. The new algorithm is exact, extremely efficient, and applicable to many important physical situations in arbitrary integer dimensions.     

Formation of pits during growth of Si/Ge nanostructures

Alternating deposition of Ge and Si in the step-flow growth regime using Bi acting as a surfactant can lead to a spontaneous formation of one atomic layer deep pits in the area of surface covered by Ge. During Si growth Ge atoms of the epitaxial 2D Ge layer move to Si step edges where stronger bonds with Si atoms are formed. Appropriate growth conditions can suppress or enhance the pit formation effect and consequently a new type of self-organized nanostructures can be formed.     

Microscopic Approach to Random Walks

In the present paper the microscopic approach to random walk models is introduced. For any particular model it provides a rigorous way to derive the transport equations for the macroscopic density of walking particles. Although it is not more complicated than the standard random walk framework it has virtually no limitations with respect to the initial distribution of particles. As a consequence, the transport equations derived with this method almost automatically give answers to such important problems as aging and two point probability distribution.     

Utilization of (p, 4n) reaction for <Superscript>86</Superscript>Zr production with medium energy protons and development of a <Superscript>86</Superscript>Zr → <Superscript>86</Superscript>Y radionuclide generator

Utilization of (p, 4n) reaction channel for the production of medical radionuclides became very attractive with commercial availability of medium energy cyclotrons. Significantly higher yields and radionuclidic purity may open new perspectives for several novel and some of the radionuclides previously have not been considered due to production difficulties. In present work, we show the proof-of-principle study on the production of ⁸⁶Y for Positron Emission Tomography imaging via radionuclide generator ⁸⁶Zr → ⁸⁶Y. Production suitability of ⁸⁶Zr from natural yttrium target and radiochemical separation strategies were tested. In addition, two generator systems were proposed and evaluated.     

Electrophoresis-Assisted Multilayer Assembly of Nanoparticles for Sensitive Lateral Flow Immunoassay**

Lateral flow immunoassay (LFIA) is a rapid, simple, and inexpensive point-of-need method. A major limitation of LFIA is a high limit of detection (LOD), which impacts its diagnostic sensitivity. To overcome this limitation, we introduce a signal-enhancement procedure that is performed after completing LFIA and involves controllably moving biotin- and streptavidin-functionalized gold nanoparticles by electrophoresis. The nanoparticles link to immunocomplexes forming multilayer aggregates on the test strip, thus, enhancing the signal. Here, we demonstrate lowering the LOD of hepatitis B surface antigen from approximately 8 to 0.12 ng mL⁻¹, making it clinically acceptable. Testing 118 clinical samples for hepatitis B showed that signal enhancement increased the diagnostic sensitivity of LFIA from 73 % to 98 % while not affecting its 95 % specificity. Electrophoresis-driven enhancement of LFIA is universal (antigen-independent), takes two minutes, and can be performed by an untrained person.     

Reply to “Comment on ‘Super‐resolution microscopy by movable thin‐films with embedded microspheres: Resolution analysis’ [Ann. Phys. (Berlin) 527, 513 (2015)]”

In a comment [A. Darafsheh, Ann. Phys. (Berlin) 528 (2016)] on our paper [K. W. Allen et al., Ann. Phys. (Berlin) 527, 513–522 (2015)], the results and conclusions of our work were doubted along two directions. The first is related to the methodology of our resolution quantification and use of confocal microscopy. The second is related to the mathematical treatment of our magnification measurements aimed at estimating the gap between the microsphere and the object which is relevant to the mechanisms of super‐resolution imaging. We explain that both our estimates of the object resolution and gap are valid. The comment brings out points that are of rather secondary relevance, does not offer a worthwhile improvement of the mathematical treatment, and misrepresents our estimation procedure for the gap size. We also discuss general factors and problems involved in the quantification of resolution in microsphere‐assisted microscopy.

     

Synthesis and investigation of antimicrobial activity of compounds derived from benzo[C][1,2,5]oxadiazole-1-oxides and phenolates

(Di)chloro(di)nitrobenzofuroxans form substitution products involving carbon atoms with phenolates in isopropyl alcohol medium. In the case of 4,6-dinitro-5,7-dichlorobenzofuroxan, besides replacement of one chlorine atom and the formation of C-bonded product, we observed the hydrolysis of the second chlorine and replacement of it by hydroxyl group. Products of reaction of 4,6-dichloro-5-nitrobenzofuroxan with phenolates display excellent antimicrobial activity and have dual action, both against bacteria and fungi.