Abstract
The diagnostic value of white matter hyperintensities (WMH) in different types of migraineare unknown. To evaluate the WMH pattern of different subtypes in migraine patients with no vascular ...risk factors. 92 migraine patients (73 females, mean age 34.6 ± 8.9; 61 episodic migraine, 31 chronic migraine, 36 migraine with aura, 56 migraine without aura) without vascular risk factors underwent brain MRI (3 T). We also included a matched healthy control group with no migraine (n = 24). The prevalence of WMH in different types of migraine was similar and ranged from 38.7 to 44.4%; the control group showed no WMH at all. Lesions were located within frontal, parietal and temporal lobes (in order of decreasing incidence) in juxtacortical and/or deep white matter. WMH appeared as round or slightly elongated foci with a median size of 2.5 mm 1.5; 3. Total number, size and prevalence of WMH by lobes and white matter regions were similar between groups, and no interaction with age or sex was found. The number of lesions within the frontal lobe juxtacortical white matter correlated with the age of patients (r = 0.331, p = 0.001) and the duration since migraine onset (r = 0.264, p = 0.012). Patients with different migraine subtypes and without vascular risk factors are characterized by a similar pattern of WMH in the absence of subclinical infarctions or microbleedings. Therefore, WMH have no relevant prognostic value regarding the course of migraine and vascular complications. WMH pattern may be used to differentiate migraine as a primary disorder and other disorders with migraine-like headache and WMH.
The influenza NS1 protein is involved in suppression of the host immune response. Recently, there is growing evidence that prion-like protein aggregation plays an important role in cellular signaling ...and immune responses. In this work, we obtained a recombinant, influenza A NS1 protein and showed that it is able to form amyloid-like fibrils in vitro. Using proteolysis and subsequent mass spectrometry, we showed that regions resistant to protease hydrolysis highly differ between the native NS1 form (NS1-N) and fibrillar form (NS1-F); this indicates that significant structural changes occur during fibril formation. We also found a protein fragment that is capable of inducing the process of fibrillogenesis at 37 °C. The discovery of the ability of NS1 to form amyloid-like fibrils may be relevant to uncovering relationships between influenza A infection and modulation of the immune response.
•Recombinant NS1 protein is capable of forming amyloid-like fibrils.•Native form NS1 features a protease-resistant fragment from a.a. residues 1 to 78.•The fibrillar NS1 form's C-terminus is hydrolyzed by trypsin least of all.•During fibril formation, SDS-resistant non-native dimers form.•The NS1 Beta domain likely plays an important role in conformational transition.
The composition of resins of seven ancient Egyptian mummies from the collection of the Pushkin State Museum of Fine Arts was studied.
n
-Alkanes were found in the resins by gas chromatography–mass ...spectrometry, which suggests the presence of natural bitumen in these resins. By comparing the hydrocarbon profiles of the studied mummies with the profiles of
n
-alkanes from mummy resins, reported in publications, the bitumen of the Dead Sea basin was identified. Concentrations of some trace elements were determined by inductively coupled plasma atomic emission spectrometry; vanadium, nickel, and molybdenum were found in the resins of five mummies. The identification of bitumen (its origin) by the relative concentrations of these elements was proposed.
•A novel photonic nanojet-based sensor system has been developed.•This system is an array of Al2O3 microspheres covered with a polymer layer impregnated with a sensitive probe.•When illuminated, the ...microstructure generates photonic nanojets that efficiently excite the sensitive layer.•Excitation of the sensitive layer via photonic nanojets provides 4-fold better sensing performance.•The demonstrated sensor system concept is customizable and can be modified to cover many non-trivial detection tasks.
A photonic nanojet phenomenon that is strong electromagnetic field local enhancement is widely used for various optical tasks like surface-enhanced Raman scattering or surface-enhanced fluorescence. Here we present a novel implementation of this effect for boosting the sensory response of the fluorescent optical probe through its more efficient pumping via photonic nanojets. For this, a sensitive layer consisting of chitosan polymer impregnated with a fluorescent probe designed for the selective determination of Au3+ ions was deposited onto the surface of an array of dielectric alumina microspheres. The photonic nanojet effect was numerically predicted and experimentally observed in the developed system. It was demonstrated that the change in the refractive index of the matrix caused by polymer swelling has a significant effect on the characteristics of the sensor. Under certain conditions, such as the diameter of the microspheres and the contrast of the refractive index a four-fold decrease in the detection limit of the chemosensor was achieved.
Two influenza A nucleoprotein variants (wild-type: G102R; and mutant: G102R and E292G) were studied with regard to macro-molecular interactions in oligomeric form (24-mers). The E292G mutation has ...been previously shown to provide cold adaptation. Molecular dynamics simulations of these complexes and trajectory analysis showed that the most significant difference between the obtained models was distance between nucleoprotein complex strands. The isolated complexes of two ribonucleoprotein variants were characterized by transmission electron microscopy and differential scanning fluorimetry (DSF). Presence of the E292G substitution was shown by DSF to affect nucleoprotein complex melting temperature. In the filament interface peptide model, it was shown that the peptide corresponding in primary structure to the wild-type NP (SGYDF
E
REGYS) is prone to temperature-dependent self-association, unlike the peptide corresponding to E292G substitution (SGYDF
G
REGYS). It was also shown that the SGYDF
E
REGYS peptide is capable of interacting with a monomeric nucleoprotein (wild type); this interaction's equilibrium dissociation constant is five orders of magnitude lower than for the SGYDF
G
REGYS peptide. Using small-angle neutron scattering (SANS), the supramolecular structures of isolated complexes of these proteins were studied at temperatures of 15, 32, and 37 °C. SANS data show that the structures of the studied complexes at elevated temperature differ from the rod-like particle model and react differently to temperature changes. The data suggest that the mechanism behind cold adaptation with E292G is associated with a weakening of the interaction between strands of the ribonucleoprotein complex and, as a result, the appearance of inter-chain interface flexibility necessary for complex function at low temperature.
Communicated by Ramaswamy H. Sarma
We studied the influence of river discharge and timing of ice retreat on sinking fluxes of total particulate matter and its components in the Laptev Sea in August–September 2017 and 2018. Vertical ...fluxes were measured with short‐term sediment traps located on the shelf adjusted to the Lena and Khatanga Rivers inflows (four shallow stations in 2017) and in Vilkitski Strait/Trough area (two deeper stations) in 2018. One station outside the Khatanga plume was repeated in both years. The effect of river discharge manifested by high total particle flux (1–1.6 g m−2 d−1), high Si (0.3 g m−2 d−1) and Al (0.1 g m−2 d−1) fluxes, a high proportion of terrigenous organic carbon (10.7%–27.5% total organic carbon) was clearly recognizable only in the shelf area closest to the Lena inflow. Large contribution of the lithogenic matter to the flux on the Laptev shelf is suggested to result also from sediment resuspension (caused by the tidal mixing and upwelling events), lateral offshore transport of sediment just above the seabed, and coastal abrasion. The magnitude of vertical fluxes of total particulate matter and organic carbon was two to three times higher in 2017 (late ice retreat) than in 2018 (early ice retreat). Centric diatoms dominated protist flux in 2017 while in 2018, dinoflagellates and tintinnids dominated. The contribution of protists to the biogenic organic carbon flux reached 62% in 2018 versus <1% in 2017. Zooplankton fecal pellet flux was not influenced by river discharge but was higher soon after ice melt.
Plain Language Summary
A major process in the ocean carbon cycle assumingly vulnerable to climate changes in the export of carbon from the surface to the deep ocean via the sinking of particulate matter. As recent warming is especially important for the Arctic Ocean, studies on the vertical fluxes there attract increasing attention. The poorly studied Laptev Sea, which is located in the center of the Siberian shelf, is of particular interest due to the high freshwater inflow and ice production. We studied the magnitude and composition of the vertical fluxes affected by riverine discharge and the timing of ice retreat. The effect of the river discharge was manifested by the increase of the total particle flux dominated by the lithogenic component and a higher share of lithogenic carbon in the organic carbon flux than outside the freshwater plume. Elevated lithogenic flux on the Laptev shelf is related not only to the riverine discharge, but also to the sediment resuspension, lateral offshore transport of sediment just above the seabed, and coastal abrasion. The timing of ice cover melt appears crucial in determining the patterns of vertical export with the higher fluxes observed soon after the sea ice brake up.
Key Points
New insights on the impact of riverine discharge and time of ice retreat on vertical particle fluxes in the Laptev Sea is presented
The effect of the river discharge was manifested by the increase of the total particle flux dominated by the lithogenic component
The timing of ice retreat is crucial in determining the patterns of vertical export with higher fluxes observed soon after ice break up
Arthrospira platensis is a filamentous cyanobacterium (Cyanophyceae), one of the most widely cultivated phototrophic microorganisms, and an efficient producer of biologically active metabolites. In ...this work, we investigate the possibility of replacing a set of standard microelements with commercially available fertilizers. As a result of the studies, it is established that the absence of microelements in the nutrient medium has a predominantly negative effect on the processes of lipogenesis. Replacing the set of standard micronutrients with commercially available fertilizers increased both the yield of the biomass and C-phycocyanin, which is a high value-added substance.
The argillized deposits of the East Pauzhetka thermal field in the Pauzhetka hydrothermal system were found to contain a zone of intensive zeolitization which consists of medium to high silica ...calcium zeolite varieties, namely, laumontite, mordenite, heulandite-Ca, and stilbite-Ca. Of all these, stilbite-Ca has the highest abundance. The zeolites can be identified well enough based both on the relationship between Si and Al, which are part of the zeolite framework, and on the concentrations of non-framework cations (Ca, Mg, Na, K, Sr, and Ba). Zeolites are mostly formed in the lower horizons of hydrothermal clays and in the underlying argillized andesites, as deep alkaline chloride-sodium hydrothermal fluids are discharged and are mixed with condensates of acid (up to neutral) vapor. The resulting sequence of zeolite generation in the shallow zone where alkaline solutions are discharged reflects, to a certain degree, a change of zeolite facies in the deeper horizons of the system: from medium-silica laumontite to high silica stilbite-Ca. We have thereby a general inference as to the regressive directivity of hydrothermal metamorphic processes in the Pauzhetka system structure, from medium-temperature propylites generated during the paleo phase to the present-day low-temperature mudstones.
Federal Law No. 468-FZ “On viticulture and winemaking in the Russian Federation” has become an important stimulus for revival and reform of the industry. One of the problems along this path has been ...the large-scale counterfeiting of Russian wines. In this regard, there is an urgent need to develop a methodology for verification and control of the authenticity of the varietal and geographical origin of Russian wines. A methodology is developed for wine verification using the digital spectra of anthocyanins and aromatic compounds obtained by high-performance liquid chromatography. Using the proposed methodology, studies are carried out to determine differences in the digital spectra of wines produced from different grape varieties; identifying their adulteration by blending with other wine materials; as well as identifying differences in the spectrum of wines produced by manufacturers from different geographical locations.
Proteins containing the NIF3 domain are highly conserved and are found in bacteria, eukaryotes, and archaea. YbgI is an
Escherichia coli
protein whose gene is conserved among bacteria. The structure ...of YbgI is known; however, the function of this protein in cells remains obscure. Our studies of
E. coli
cells with deleted
ybgI
gene suggest that YbgI is involved in formation of the bacterial cell wall.
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