SHARPER reaction monitoring: generation of a narrow linewidth NMR singlet, without X-pulses, in an inhomogeneous magnetic field

We report a new pure-shift method, termed SHARPER (Sensitive, Homogeneous, And Resolved PEaks in Real time) designed for the analysis of reactions and equilibria by NMR. By focusing on a single selected signal, SHARPER removes all heteronuclear couplings of a selected nucleus without the need to pulse on X channels, thus overcoming hardware limitations of conventional spectrometers. A more versatile decoupling scheme, termed <i>sel</i>-SHARPER, removes all heteronuclear and homonuclear couplings of the selected signal. Both methods are characterized by a periodic inversion of the active spin during the real-time acquisition. In addition to decoupling, they also compensate for pulse imperfections and magnetic field inhomogeneity, generating an extremely narrow singlet with a linewidth approaching limits dictated by the spin–spin relaxation. The decoupling and line narrowing effected by (<i>sel</i>)-SHARPER provide significant increases in the signal-to-noise (S/N) ratio. Increases of 20-fold were routinely achieved for ¹⁹F detection. <i>sel</i>-SHARPER is also applicable to first- and higher-order ¹H spectra. The sensitivity gains are substantially greater for inhomogeneous magnetic fields, including dynamic inhomogeneity caused by gas sparging. The parameters of the pulse sequences have been analyzed in detail to provide guidelines for their most effective application. The considerable reduction in the detection threshold induced by (<i>sel</i>)-SHARPER make the technique particularly suited for <i>in situ</i> monitoring of reaction kinetics. The approach is illustrated by a ¹⁹F NMR study of the protodeboronation of an aryl boronic acid. Here, the high S/N allowed reliable determination of the net protodeoboronation kinetics, and the excess line broadening of ¹⁹F singlets was utilized to characterize the boronic acid/boronate equilibrium kinetics. Oxidation of diphenylphosphine, monitored by ³¹P NMR under optimized gas-flow conditions, demonstrated the high tolerance of SHARPER to dynamic inhomogeneity. The principles of the (<i>sel</i>)-SHARPER sequences are expected to find numerous applications in the design of new NMR experiments

In search of Q: results on identification in structural vector autoregressive models

The thesis consists of three independent research papers in the area of identification of structural vector autoregressive (SVAR) models. The first paper studies the government spending shocks on output. New sign restrictions on the impulse responses are introduced to the fiscal policy literature. Upon imposing the new sign restrictions, we find contractionary output reactions to positive government spending shocks. The results are robust to several alternative model and sign restriction specifications. The second paper investigates the implications of including more (forward-looking) information in a classical monetary policy SVAR. We augmenting the classical specification with federal funds futures and factors extracted from a large macroeconomic dataset. It is established that information-augmentation does not necessarily yield shocks that are correlated more strongly with benchmark monetary policy shocks. The empirical conclusions based on the baseline and augmented specifications are similar: monetary policy shocks contribute only marginally to the evolution of (real) macroeconomic variables. The third paper‘s empirical motivation is to quantify the effects of monetary policy shocks on asset prices. We set up a monetary SVAR including the S&P500 series, and we use set identifying sign and zero restrictions. It is established that the majority of monetary policy shocks estimated from admissible structural models correlate only weakly with benchmark monetary policy shocks. Structural models with medium correlations, imply impulse responses that vary widely in their shapes and magnitudes. Concentrating, however, only on the 100 models with the highest correlations uncovers negative, but near-zero asset price responses to positive monetary policy shocks, coupled with mildly positive output responses

The Mongol Invasion of Hungary in Its Eurasian Context

This report gives an account of the historiography of the Mongol invasion of Hungary in 1241–1242, and the ongoing research of the project “The Mongol Invasion of Hungary in its Eurasian Context.” The research has been carried out by an interdisciplinary team comprising representatives of diverse academic institutions and fields. The primary objective of the project was to reassess existing scholarship by comparing it with the findings of the project team members, ultimately generating new scholarly insights. The team members concentrated on various aspects, including archaeology, military history, and the short- and long-term impacts of the Mongol military invasions in the mid-thirteenth century

CLEC-2 and Syk in the megakaryocytic/platelet lineage are essential for development

The C-type lectin receptor CLEC-2 signals through a pathway that is critically dependent on the tyrosine kinase Syk. We show that homozygous loss of either protein results in defects in brain vascular and lymphatic development, lung inflation and perinatal lethality. Furthermore, we find that conditional deletion of Syk in the haematopoietic lineage, or conditional deletion of CLEC-2 or Syk in the megakaryocyte/platelet lineage, also causes defects in brain vascular and lymphatic development, although the mice are viable. In contrast, conditional deletion of Syk in other haematopoietic lineages had no effect on viability or brain vasculature and lymphatic development. We show that platelets, but not platelet releasate, modulate the migration and intercellular adhesion of lymphatic endothelial cells through a pathway that is dependent on CLEC-2 and Syk. These studies demonstrate that megakaryocyte/platelet expression of CLEC-2 and Syk is required for normal brain vasculature and lymphatic development and that platelet CLEC-2 and Syk directly modulate lymphatic endothelial cell behaviour in vitro

Increasing Incidence of Geomyces destructans Fungus in Bats from the Czech Republic and Slovakia

BACKGROUND: White-nose syndrome is a disease of hibernating insectivorous bats associated with the fungus Geomyces destructans. It first appeared in North America in 2006, where over a million bats died since then. In Europe, G. destructans was first identified in France in 2009. Its distribution, infection dynamics, and effects on hibernating bats in Europe are largely unknown. METHODOLOGY/PRINCIPAL FINDINGS: We screened hibernacula in the Czech Republic and Slovakia for the presence of the fungus during the winter seasons of 2008/2009 and 2009/2010. In winter 2009/2010, we found infected bats in 76 out of 98 surveyed sites, in which the majority had been previously negative. A photographic record of over 6000 hibernating bats, taken since 1994, revealed bats with fungal growths since 1995; however, the incidence of such bats increased in Myotis myotis from 2% in 2007 to 14% by 2010. Microscopic, cultivation and molecular genetic evaluations confirmed the identity of the recently sampled fungus as G. destructans, and demonstrated its continuous distribution in the studied area. At the end of the hibernation season we recorded pathologic changes in the skin of the affected bats, from which the fungus was isolated. We registered no mass mortality caused by the fungus, and the recorded population decline in the last two years of the most affected species, M. myotis, is within the population trend prediction interval. CONCLUSIONS/SIGNIFICANCE: G. destructans was found to be widespread in the Czech Republic and Slovakia, with an epizootic incidence in bats during the most recent years. Further development of the situation urgently requires a detailed pan-European monitoring scheme

Lycopene: total-scale literature landscape analysis of a valuable nutraceutical with numerous potential applications in the promotion of human and animal health

Lycopene intake from tomatoes and other food sources has multiple potential health benefits. This report aimed to evaluate the current research literature on lycopene concerning human and animal health. The electronic Web of Science Core Collection database was searched with (lycopene*) AND (health* OR illness* OR disease* OR medic* OR pharma* OR drug* OR therap*). The resulted 3972 papers were analyzed with the aid of bibliometric software. Besides the United States, the lycopene papers received global contributions, particularly from China, Italy, India, and Spain. Examples of frequently mentioned chemicals/chemical classes were carotenoid, beta carotene, alpha carotene, beta cryptoxanthin, and alpha tocopherol. Examples of frequently mentioned medical conditions were prostate cancer, cardiovascular disease, and obesity. Published scientific articles reveal the diverse potential of lycopene in prompting human and animal health, and the knowledge on the bioactivities of this phytoche(undefined)info:eu-repo/semantics/publishedVersio