Imaging surface plasmon resonance for multiplex microassay sensing of mycotoxins

A prototype imaging surface plasmon resonance-based multiplex microimmunoassay for mycotoxins is described. A microarray of mycotoxin–protein conjugates was fabricated using a continuous flow microspotter device. A competitive inhibition immunoassay format was developed for the simultaneous detection of deoxynivalenol (DON) and zearalenone (ZEN), using a single sensor chip. Initial in-house validation showed limits of detection of 21 and 17 ng/mL for DON and 16 and 10 ng/mL for ZEN in extracts, which corresponds to 84 and 68 µg/kg for DON and 64 and 40 µg/kg for ZEN in maize and wheat samples, respectively. Finally, the results were critically compared with data obtained from liquid chromatography-mass spectrometry confirmatory analysis method and found to be in good agreement. The described multiplex immunoassay for the rapid screening of several mycotoxins meets European Union regulatory limits and represents a robust platform for mycotoxin analysis in food and feed sample

Acceleration of the precession frequency for optically-oriented electron spins in ferromagnetic/semiconductor hybrids

Time-resolved Kerr rotation measurements were performed in InGaAs/GaAs quantum wells nearby a doped Mn delta layer. Our magneto-optical results show a typical time evolution of the optically-oriented electron spin in the quantum well. Surprisingly, this is strongly affected by the Mn spins, resulting in an increase of the spin precession frequency in time. This increase is attributed to the variation in the effective magnetic field induced by the dynamical relaxation of the Mn spins. Two processes are observed during electron spin precession: a quasi-instantaneous alignment of the Mn spins with photo-excited holes, followed by a slow alignment of Mn spins with the external transverse magnetic field. The first process leads to an equilibrium state imprinted in the initial precession frequency, which depends on pump power, while the second process promotes a linear frequency increase, with acceleration depending on temperature and external magnetic field. This observation yields new information about exchange process dynamics and on the possibility of constructing spin memories, which can rapidly respond to light while retaining information for a longer period.Comment: 7 pages, 5 figure

Predictive scales and ECG indicators in the acute stroke period

The features of the ECG in patients with different values of the SAPS and APACHE II scales in the acute period of stroke were investigated. Despite the fact that the APACHE II and SAPS scales do not include ECG parameters, a number of ECG parameters significantly differ in patients with acute stroke at different values according to these scales. The prognosis aggravation according to the studied scales was not always accompanied by the same type of ECG parameters changes. Survived patients with high APACHE II scores were characterized by high dysmorphic values of ECG amplitude parameters. Died patients with high risks on both scales showed an increase in dysmorphism in many ECG parameters. The scientific novelty of the study is in the detection of ECG features at different values of the SAPS and APACHE II scales in the acute period of stroke.Изучены особенности ЭКГ у пациентов при разных значениях шкал SAPS и APACHE II в остром периоде инсульта. Несмотря на то, что шкалы APACHE II и SAPS не включают в себя параметры ЭКГ, у пациентов с острым инсультом при различных значениях по данным шкалам ряд показателей ЭКГ достоверно отличались. Ухудшение прогноза по изученным шкалам не всегда сопровождалось однотипными изменениями показателей ЭКГ. Выжившие пациенты с высокими значениями по шкале APACHE II характеризовались большими показателями дизморфности амплитудных значений ЭКГ. Умершие пациенты с высокими рисками по обеим шкалам демонстрировали увеличение дизморфности по многим показателям ЭКГ. Научная новизна исследования заключается в обнаружении особенностей ЭКГ при различных рисках осложнений по шкалам SAPS и APACHE II в остром периоде инсульта

A new method to position and functionalize metal-organic framework crystals

With controlled nanometre-sized pores and surface areas of thousands of square metres per gram, metal-organic frameworks (MOFs) may have an integral role in future catalysis, filtration and sensing applications. In general, for MOF-based device fabrication, well-organized or patterned MOF growth is required, and thus conventional synthetic routes are not suitable. Moreover, to expand their applicability, the introduction of additional functionality into MOFs is desirable. Here, we explore the use of nanostructured poly-hydrate zinc phosphate (α-hopeite) microparticles as nucleation seeds for MOFs that simultaneously address all these issues. Affording spatial control of nucleation and significantly accelerating MOF growth, these α-hopeite microparticles are found to act as nucleation agents both in solution and on solid surfaces. In addition, the introduction of functional nanoparticles (metallic, semiconducting, polymeric) into these nucleating seeds translates directly to the fabrication of functional MOFs suitable for molecular size-selective applications