PMR characterization of the water structure in tibetan milk mushroom zooglea: influence of medium hydration and hydrophobicity

The state of water in Tibetan milk mushroom zooglea with different degrees of hydration (h) was investigated using low-temperature PMR spectroscopy in air and in contact with the hydrophobic media polydimethylsiloxane PDMS-1000 and CHCl3 with added trifl uoroacetic acid (TFA). The maximum hydration of the zooglea amounted to h = 32 g/g (of dry matter). Water existed as polyassociates (clusters or domains) of strongly and weakly associated water. Bound water decomposed into clusters in the presence of TFA. The NMR spectra showed six types of bound water at h = 0.3 g/

COVID-19-associated coagulopathy in children and adolescents

The pandemic of the new coronavirus infection COVID-19 in 2020 has become the main health problem across the globe. A special characteristic of the SARSCoV-2 virus is tropism to the vascular endothelium with the  development of endotheliitis, which entails a number of typical disorders of the blood coagulation system: coagulopathy with increased thrombin generation, D-dimer, decreased fibrinolysis and prolonged prothrombin time. The coagulation disorder in COVID-19 is called thromboinflammation. Hyperinflammation, increased blood levels of von Willebrand factor, coagulation factor VIII, neutrophil extracellular traps, platelet activation, microvesicles play a significant role in the pathogenesis of hypercoagulation in COVID-19. To date, it is known that cases of COVID-19 in children and adolescents constitute a small part of the total number of patients with diagnosed COVID-19, and disorders of the blood coagulation system are similar to those in adults. The degree of hypercoagulable syndrome and the risk of thrombosis depend on the severity of COVID-19. And for children they are most expressed with the development of a hyperinflammatory immune response, called multisystem inflammatory syndrome. At the same time, clinical studies of the pathogenesis of COVID-19 in adults and children and the search for optimal methods of therapy for thrombus inflammation, which underlies the pathogenesis of COVID-19, continue

Використання ефекту мікрокоагуляції для керування зв'язуванням води у гетерогенній системі поліметилсилоксан/кремнезем/вода

The binding of water in heterogeneous systems containing polymethylsiloxane (PMS) pyrogenic nanosilica (A-300) water and the surface-active substance decametoxin (DMT) was studied. Composite systems were created using metered mechanical loads. The low-temperature 1H NMR spectroscopy was used to measure the structural and thermodynamic parameters of bound water. It is shown that when filling PMS interparticle gaps with hydrocompaction, the interfacial energy of water in the interparticle gaps of hydrophobic PMS with the same hydration is twice as large as the interfacial energy of water in hydrophilic silica A-300. This is due to the smaller linear dimensions of the interparticle gaps in the ICP compared with the A-300. In the composite system, A-300/PMS/DMT/H2O, a non-additive growth of water binding energy is observed, which is likely due to the formation, under the influence of mechanical load in the presence of water, of microheterogeneous sites, consisting mainly of the hydrophobic and hydrophilic components (microcoagulation). Thus, using mechanical loads, you can control the adsorption properties of composite systems.Вивчено зв'язування води в гетерогенних системах, що містять поліметилсилоксан, високодисперсний аморфний кремнезем, воду і поверхнево-активну речовину – декаметоксин. Композитні системи створювалися при використанні дозованих механічних навантажень. Методом низькотемпературної 1Н ЯМР-спектроскопії вимірювалися структурні і термодинамічні параметри зв'язаної води. Показано, що при заповненні міжчастинкових зазорів поліметилсилоксану способом гідроущільнення, міжфазна енергія води при однаковій гідратованості вдвічі перевищує міжфазну енергію води в гідрофільному кремнеземі. Це пов'язано з меншими лінійними розмірами міжчастинкових зазорів в поліметилсилоксані порівняно з кремнеземом. В композитній системі, кремнезем/поліметилсилоксан/декаметоксин/вода спостерігається неадитивне зростання енергії зв'язування води, яке, ймовірно, обумовлене формуванням, під впливом механічного навантаження в присутності води, мікрогетерогенних ділянок, що складаються переважно з гідрофобної і гідрофільної компонент (мікрокоагуляція). Таким чином, за допомогою механічних навантажень можна керувати адсорбційними властивостями композитних систе

A mononuclear iron(III) complex with unusual changes of color and magneto-structural properties with temperature: synthesis, structure, magnetization, multi-frequency ESR and DFT study

From the reaction of 2-hydroxy-6-methylpyridine (L) with iron(II) tetrafluoroborate, a new mononuclear iron(III) octahedral complex [FeL6](BF4)3 has been isolated. The color of the complex reversibly changed from red at room temperature to yellow-orange at the liquid nitrogen temperature. Magnetization measurements indicate that iron(III) in [FeL6](BF4)3 is in a high-spin state S = 5/2, from room temperature to 1.8 K. The high-spin ground state of iron(III) is also confirmed by DFT calculations. Although the spin-crossover of the complex is not observed, X-band and multifrequency high-field/high-frequency electron spin resonance (ESR) spectroscopy shows rather uncommon iron(III) spectra at room temperature and an unusual change with cooling. Spectral simulations reveal that the S = 5/2 ground state multiplet of the complex can be characterized by the temperature independent axial zero-field splitting parameter of |D| = +2 GHz (0.067 cm−1) while the value of the rhombic parameter E of the order of some tenths MHz increases on lowering the temperature. Single crystal X-ray diffraction (SCXRD) shows that the iron(III) coordination geometry does not change with temperature while supramolecular interactions are temperature dependent, influencing the iron(III) rhombicity. Additionally, the DFT calculations show temperature variation of the HOMO–LUMO gap, in agreement with the changes of color and ESR-spectra of the iron(III) complex with temperature

Newly identified climatically and environmentally significant high-latitude dust sources

Peer reviewe

Newly identified climatically and environmentally significant high-latitude dust sources

Dust particles from high latitudes have a potentially large local, regional, and global significance to climate and the environment as short-lived climate forcers, air pollutants, and nutrient sources. Identifying the locations of local dust sources and their emission, transport, and deposition processes is important for understanding the multiple impacts of high-latitude dust (HLD) on the Earth\u27s systems. Here, we identify, describe, and quantify the source intensity (SI) values, which show the potential of soil surfaces for dust emission scaled to values 0 to 1 concerning globally best productive sources, using the Global Sand and Dust Storms Source Base Map (G-SDS-SBM). This includes 64 HLD sources in our collection for the northern (Alaska, Canada, Denmark, Greenland, Iceland, Svalbard, Sweden, and Russia) and southern (Antarctica and Patagonia) high latitudes. Activity from most of these HLD sources shows seasonal character. It is estimated that high-latitude land areas with higher (SI ≥0.5), very high (SI ≥0.7), and the highest potential (SI ≥0.9) for dust emission cover >1 670 000 km$^{2}$, >560 000 km$^{2}$, and >240 000 km$^{2}$, respectively. In the Arctic HLD region (≥60$^{∘}$ N), land area with SI ≥0.5 is 5.5 % (1 035 059 km$^{2}$), area with SI ≥0.7 is 2.3 % (440 804 km$^{2}$), and area with SI ≥0.9 is 1.1 % (208 701 km$^{2}$). Minimum SI values in the northern HLD region are about 3 orders of magnitude smaller, indicating that the dust sources of this region greatly depend on weather conditions. Our spatial dust source distribution analysis modeling results showed evidence supporting a northern HLD belt, defined as the area north of 50$^{∘}$ N, with a “transitional HLD-source area” extending at latitudes 50–58∘ N in Eurasia and 50–55$^{∘}$ N in Canada and a “cold HLD-source area” including areas north of 60$^{∘}$ N in Eurasia and north of 58$^{∘}$ N in Canada, with currently “no dust source” area between the HLD and low-latitude dust (LLD) dust belt, except for British Columbia. Using the global atmospheric transport model SILAM, we estimated that 1.0 % of the global dust emission originated from the high-latitude regions. About 57 % of the dust deposition in snow- and ice-covered Arctic regions was from HLD sources. In the southern HLD region, soil surface conditions are favorable for dust emission during the whole year. Climate change can cause a decrease in the duration of snow cover, retreat of glaciers, and an increase in drought, heatwave intensity, and frequency, leading to the increasing frequency of topsoil conditions favorable for dust emission, which increases the probability of dust storms. Our study provides a step forward to improve the representation of HLD in models and to monitor, quantify, and assess the environmental and climate significance of HLD