Picoflare jets power the solar wind emerging from a coronal hole on the Sun.

Coronal holes are areas on the Sun with open magnetic field lines. They are a source region of the solar wind, but how the wind emerges from coronal holes is not known. We observed a coronal hole using the Extreme Ultraviolet Imager on the Solar Orbiter spacecraft. We identified jets on scales of a few hundred kilometers, which last 20 to 100 seconds and reach speeds of ~100 kilometers per second. The jets are powered by magnetic reconnection and have kinetic energy in the picoflare range. They are intermittent but widespread within the observed coronal hole. We suggest that such picoflare jets could produce enough high-temperature plasma to sustain the solar wind and that the wind emerges from coronal holes as a highly intermittent outflow at small scales.

Ultra-high-resolution observations of persistent null-point reconnection in the solar corona.

Magnetic reconnection is a key mechanism involved in solar eruptions and is also a prime possibility to heat the low corona to millions of degrees. Here, we present ultra-high-resolution extreme ultraviolet observations of persistent null-point reconnection in the corona at a scale of about 390 km over one hour observations of the Extreme-Ultraviolet Imager on board Solar Orbiter spacecraft. The observations show formation of a null-point configuration above a minor positive polarity embedded within a region of dominant negative polarity near a sunspot. The gentle phase of the persistent null-point reconnection is evidenced by sustained point-like high-temperature plasma (about 10 MK) near the null-point and constant outflow blobs not only along the outer spine but also along the fan surface. The blobs appear at a higher frequency than previously observed with an average velocity of about 80 km s-1 and life-times of about 40 s. The null-point reconnection also occurs explosively but only for 4 minutes, its coupling with a mini-filament eruption generates a spiral jet. These results suggest that magnetic reconnection, at previously unresolved scales, proceeds continually in a gentle and/or explosive way to persistently transfer mass and energy to the overlying corona.

Modified Polyethylene Foam for Critical Environments.

One of the most important priorities for all countries with property beyond the Arctic Circle and territories located in permafrost areas is the development of special construction technologies and systems. The required conditions are met by insulation systems based on seamless insulation shells made of polyethylene foam. The study of the strength and performance properties of polyethylene foam and its combinability was carried out according to standard methods and using the methods of experimental design and the analytical processing of the results. The change in material properties at negative temperatures was determined based on the results of climatic tests, followed by an evaluation of creep under load. The evaluation of the effectiveness of the design solutions was carried out using special computer programs. It was found that the performance characteristics of products made of polyethylene foam (rolls, mats) meet the requirements for insulation materials used at temperatures down to -60 °C. The resulting material is moderately combustible, which must be taken into account when developing recommendations for its use in insulation systems. A nomogram has been developed that makes it possible to predict the properties of a material and solve formulation problems. Insulation systems were developed, and a visualisation of the thermal fields of the insulation systems of the external walls and ceilings of a building was carried out.

Preclinical efficacy investigation of human neutrophil elastase inhibitor sivelestat in animal model of psoriasis.

Background: Psoriasis is a chronic immune-mediated inflammatory skin disease manifested by an increased rate of keratinocyte division. Currently, it has been established that the cytokines of the IL-36 family play a significant role in the initiation and regulation of the inflammatory process in psoriasis. The IL-36 cytokine found in skin is inactive and its activation requires proteolytic processing that may occur via the involvement of neutrophil serine proteases such as human neutrophil elastase (HNE). The localization of these enzymes in the upper layers of the epidermis suggests that topical application of HNE inhibitors could be efficacious in the treatment of psoriasis. Sivelestat is an HNE inhibitor developed for systemic use towards the treatment of acute respiratory failure. Aim: The present study focussed on the investigation of the effects of sivelestat formulated for topical use, in the imiquimod-induced model of psoriasis in mice. Methods: The psoriasis-like state was induced by application of imiquimod (Aldara®) 5% cream to mouse shaven skin. A group of 40 inbred mice of the BALB/c strain randomized into 4 groups of 10 was used in the experiment: Group 1 - no therapy (control), Group 2 - ointment (Vaseline) containing 1% sivelestat, Group 3 - cream (lanoline + olive oil + water in equal proportions) containing 1% sivelestat, Group 4 - 1% betamethasone dipropionate. Dermatological assessment of skin lesions was performed by means of the PASI method (mPASI), as well as histological and immunohistochemical evaluation. Results: Based on the evaluation of efficacy manifestations, it was established that the total mPASI index value decreased by 50% during therapy with sivelestat cream and by 36% during therapy with sivelestat ointment. Histological study revealed that the epidermal thickness in groups that underwent therapy was 2.4-3.6 times lower compared to the control group. Immunohistochemical study of the skin indicated that following sivelestat treatment, the quantity of CD3+cells in the skin was 1.8-2.2 times lower, and the level of proliferative activity (Ki-67+cells) was 2.3-2.9 lower compared to the non-therapy group. In contrast to topical corticosteroids where the more pronounced anti-inflammatory effect is typically seen with ointment formulations, with sivelestat we observed an opposite effect. The reasons for that reversal remain unclear. Conclusion: Based on the results obtained using the animal model of imiquimod-induced psoriasis, it was established that the HNE inhibitor sivelestat demonstrated efficacy comparable to that of a strong topical glucocorticoid steroidal drug (betamethasone dipropionate 1%). Significant resolution of skin lesions, reduction of epidermal thickness, diminishing of the skin infiltration with T-lymphocytes and normalization of the cell division rate in epidermis and dermis were evident. Thus, suppression of IL-36 mediated inflammation activity in the skin by topical application of a HNE inhibitor represents a promising new direction in the treatment of psoriasis. Certainly, HNE has other targets; thus, molecular studies could be subject of future experiments beyond the scope of the present study.

Foam Polymers in Multifunctional Insulating Coatings.

The application of foamed polymers as one of the components of insulating coatings allows to solve the problems of energy saving and creation of optimal operating conditions for constructions. The systems of application of energy-efficient heat-insulating materials must consider both the particularities of the insulating materials and the functional orientation of the constructions. The implementation of the concept of seamless insulating coatings implies the achievement of thermal effect and reduction in air permeability both by means of the application of thermal insulation with low thermal conductivity and the minimization of junctions between separate elements of the insulating coating, which is achieved using elastic foamed polymers and, first of all, polyethylene foam. Construction of seamless insulating coatings creates practically impermeable heat, vapor, and water barriers along the outer perimeter of the insulated object. Multilayer products based on polyethylene foam represent a relatively new material-a fact that requires examination of their properties, as well as under various operating conditions, and development of a methodology for evaluation of the operational resistance of these materials in structures of different purposes, including cold conservation. The performed tests have shown that the compressive strength at 10% deformation is determined by the function of load application area and varies from 70 kPa during the test of cube samples of 10 × 10 × 10 in size to 260 kPa for areas exceeding 100 m2. The longitudinal tensile strength amounts to 80-92 kPa, and the strength of the weld seam is equal to 29-32 kPa. It has been established that the values of thermal conductivity of polyethylene foam with an average density of 18-20 kg/m3 amounts to 0.032-0.034 W/(m·K), diffusion moisture absorption is equal to 0.44 kg/m2 without a metallized coating and 0.37 kg/m2 with a metallized coating; water absorption after partial immersion in water for 24 h amounts to 0.013 kg/m2; water absorption by volume after complete water immersion for 28 days is equal to 0.96%. The material does not practically change its properties under conditions of long-term temperature alteration from -60 to +70 °C. The developed and implemented insulation systems for protective surfaces of framed construction objects, rubbhalls and frameless structures, floating floors, indoor ice rinks, and snow conservation systems are presented.

Quantum-dot microlasers based on whispering gallery mode resonators.

The subject of this paper is microlasers with the emission spectra determined by the whispering gallery modes. Owing to the total internal reflection of light on the sidewalls, a high Q-factor is achieved until the diameter is comparable to the wavelength. The light emission predominantly occurs in the plane of the structure, which facilitates the microlaser integration with other elements. We focus on microdisk lasers with various types of the In(Ga)As quantum dots (QDs). Deep localization of charge carriers in spatially separated regions suppresses the lateral diffusion and makes it possible to overcome the undesirable effect of non-radiative recombination in deep mesas. Thus, using conventional epitaxial structures and relatively simple post-growth processing methods, it is possible to realize small microlasers capable of operating without temperature stabilization at elevated temperatures. The low sensitivity of QDs to epitaxial and manufacturing defects allows fabricating microlasers using III-V heterostructures grown on silicon.

[Vitamin D metabolite and calcium phosphorus metabolism in in patients with primary hyperparathyroidism on the background of bolus therapy with colecalciferol].

BACKGROUND: Vitamin D (25-hydroxyvitamin D [25(ОН)D]) deficiency (<20 ng/mL) and insufficiency (20-29 ng/mL) are common in primary hyperparathyroidism (PHPT), but data regarding the vitamin D metabolism in this population is limited. AIM: The aim of this study is to estimate the vitamin D metabolites and their relationship with the main parameters of phosphorus-calcium metabolism in patients with PHPT at baseline and on the background of a single dose of cholecalciferol 150,000 IU. MATERIALS AND METHODS: A single-center interventional, dynamic, prospective, comparative study has been carried out. The study included 54 participants, divided into two groups: the 1st group included 27 patients with confirmed PHPT, the 2nd control group (n = 27), matched on gender (p = 0.062). The study included 4 visits; the baseline laboratory examination and a bolus dose of cholecalciferol were performed at the visit 1, the subsequent visits included a dynamic laboratory examination. RESULTS: Vitamin D deficiency (<20 ng/ml) was detected in 69% of patients with PHPT. In the PHPT group (before cholecalciferol therapy), there was a direct association of 1.25(OH)2 D3 with albumin-corrected and ionized calcium, as well as between the 25(OH)D3 /24.25(OH)2 D3 ratio with PTH and magnesium. After taking of cholecalciferol, the levels of 1.25(OH)2 D3 and 25(OH)D3 /24.25(OH)2 D3 were significantly increased, and the levels of 25(OH)D3 /1.25(OH)2 D3 were significantly declined at all visits among patients with PHPT. The common 25(OH)D level was comparable to the control group, however the levels of 1,25(OH)2 D3 in patients with PHPT were 55% higher at baseline, and after taking of cholecalciferol 150,000 IU. They remained increased by 3-7 days by an additional 23-36%, significantly higher than those in the control group: 44%, 74% and 65%, at visits 2, 3 and 4, respectively (p<0.05). The taking of 150,000 IU cholecalciferol in the PHPT group did not lead to a significant increase in hypercalcemia and hypercalciuria, which indicates the safety of this dose in patients with mild hypercalcemia (albumin corrected calcium <3 mmol/l). None of the study participants experienced any side effects. CONCLUSION: The completely comprehensive assessment of vitamin D metabolites was carried out for the first time in patients with PHPT before and after using a bolus dose of cholecalciferol. The results confirmed the differences of vitamin D metabolism in chronic excessive secretion of PTH compared to control group, which is new data in the pathogenesis of the disease, and can be used to develop optimal regimens for cholecalciferol taking in this population.

Detuning effects in Brillouin ring microresonator laser.

Brillouin lasers, with their unique properties, offer an intriguing solution for many applications, yet bringing their performance to integrated platforms has remained questionable. We present a theoretical framework to describe Brillouin lasing in integrated ring microcavities. Specifically, a general case of a mismatch between the Brillouin shift and the microresonator inter-mode spacing is considered. We show that although the lasing threshold is increased with the frequency detuning, a significant enhancement of the laser power in comparison with the pure resonant interaction could be achieved. Moreover, there is an optimal pump frequency detuning from the resonant mode frequency, when the effect is most pronounced. An increase of the Brillouin threshold with the pump frequency detuning is accompanied by narrowing the pump frequency range available for lasing. Importantly, at the optimal value of the pump frequency detuning when the Brillouin signal is maximal, Brillouin signal noise level is minimal. Analytical results obtained in the steady-state approach are in quantitative agreement with the results of numerical simulations.

Installation and commissioning of the ion source systems for the new spallation neutron source 2.5 MeV injector.

The U.S. Spallation Neutron Source (SNS) is a state-of-the-art neutron scattering facility delivering the world's most intense pulsed neutron beams to a wide array of instruments, which are used to conduct investigations in many fields of engineering, physics, chemistry, material science, and biology. Neutrons are produced by spallation of liquid Hg by the bombardment of short (∼1 µs), intense (∼35 A) pulses of protons delivered at 60 Hz by an accumulator ring which is fed by a high-intensity, 1 GeV, H- LINAC (linear accelerator). This facility has operated nearly continuously since 2006 but has recently undergone a 4-month maintenance period, which featured a complete replacement of the 2.5 MeV injector feeding the LINAC. The new injector was developed at ORNL in an off-line beam test facility and consists of an ion source, low energy beam transport, and a Radio Frequency Quadrupole (RFQ). This report first describes the installed configuration of the new injector detailing the ion source system. The first beam current, RFQ transmission, emittance, and energy measurements from the injector installed on the SNS are reported. These data not only show a significant performance improvement for our existing facility but will also make accessible the higher beam current requirements for future SNS upgrade projects: the proton power upgrade and second target station.

Glass-coated ferromagnetic microwire-induced magnetic hyperthermia for in vitro cancer cell treatment.

Limitations in effectiveness and the invasive nature of current cancer treatment options emphasize the need for further clinical advancements. Among other approaches, targeted hyperthermia is as a new strategy aimed at targeting cancerous cells to improve the efficacy of radiotherapy or cytotoxic drugs. However, the testing of magnetic vehicles has mainly focused on the use of nanoparticles. In this work, Fe77B10Si10C3 glass-coated amorphous magnetic microwires were assessed for the first time as magnetic vehicles with high potential for the localized heating of osteosarcoma cells by means of an AC magnetic field. The results from the in vitro assays performed inside a microfluidic device demonstrated the ability of these magnetic microwires to induce malignant cell death. Exposing the system to different magnetic fields for less than 1 h provoked a reduction up to 89% of the osteosarcoma cell population, whereas healthy myoblastoma cells remained nearly unaffected. The proposed technology demonstrates in vitro the effectiveness of these microwires as vehicles for targeted magnetic hyperthermia.

Inhibition of Neutrophil Elastase and Cathepsin G As a New Approach to the Treatment of Psoriasis: From Fundamental Biology to Development of New Target-Specific Drugs.

Psoriasis therapy remains an extremely relevant area of modern drug design, due to necessity of adverse reaction reduction, inherent for actual methods of therapy. It was established that two serine proteases-neutrophil elastase 1 (HNE1) and cathepsin G (CatG)-are the key agents in psoriasis development. The collected molecular data for the presented targets form the basis for the molecular modeling strategy for the search for and identification of new target-specific inhibitors. The result of this work is a group of high-priority small-molecule compounds with double-targeted affinity, which are able to suppress the pro-psoriatic processes induced by the considered serine proteases at the initial stage of the disease.

Engineering of Magnetic Softness and Domain Wall Dynamics of Fe-rich Amorphous Microwires by Stress- induced Magnetic Anisotropy.

We observed a remarkable improvement of domain wall (DW) mobility, DW velocity, giant magnetoimpedance (GMI) effect and magnetic softening at appropriate stress-annealing conditions. Beneficial effect of stress-annealing on GMI effect and DW dynamics is associated with the induced transverse magnetic anisotropy. An improvement of the circumferential permeability in the nearly surface area of metallic nucleus is evidenced from observed magnetic softening and remarkable GMI effect rising. We assumed that the outer domain shell with transverse magnetic anisotropy associated to stress-annealing induced transverse magnetic anisotropy affects the travelling DW in a similar way as application of transversal bias magnetic field allowing enhancement the DW velocity. Observed decreasing of the half-width of the EMF peak in stress-annealed microwires can be associated to the decreasing of the characteristic DW width. Consequently, stress annealing enabled us to design the magnetic anisotropy distribution beneficial for optimization of either GMI effect or DW dynamics.

Visualization and investigation of the non-thermalized electrons in an InAs nanowire by scanning gate microscopy.

We performed scanning gate microscopy measurements on an InAs nanowire at T = 4.2 K in an external magnetic field. We visualizeded non-thermalized electrons passed under narrow metallic contact. It was found that, for such kind of electrons, suppression of the weak antilocalization quantum correction occurs with a magnetic field at least three times smaller than the corresponding one measured for the whole electronic system of the wire.

Virtual cavity in distributed Bragg reflectors.

We show theoretically and experimentally that distributed Bragg reflector (DBR) supports a surface electromagnetic wave exhibiting evanescent decay in the air and oscillatory decay in the DBR. The wave exists in TM polarization only. The field extension in the air may reach several wavelengths of light. Once gain medium is introduced into the DBR a novel class of diode lasers, semiconductor optical amplifiers, light-emitting diodes, etc. can be developed allowing a new type of in-plane or near-field light outcoupling. To improve the wavelength stability of the laser diode, a resonant cavity structure can be coupled to the DBR, allowing a coupled state of the cavity mode and the near-field mode. A GaAlAs-based epitaxial structure of a vertical-cavity surface-emitting laser (VCSEL) having an antiwaveguiding cavity and multiple GaInAs quantum wells as an active region was grown and processed as an in-plane Fabry-Pérot resonator with cleaved facets. Windows in the top stripe contact were made to facilitate monitoring of the optical modes. Three types of the optical modes were observed in electroluminescence (EL) studies under high current densities > 1 kA/cm2. Mode A with the longest wavelength is a VCSEL-like mode emitting normal to the surface. Mode B has a shorter wavelength, emitting light at two symmetric lobes tilted with respect to the normal to the surface in the direction parallel to the stripe. Mode C has the shortest wavelength and shifts with a temperature at a rate 0.06 nm/K. Polarization studies reveal predominantly TE emission for modes A and B and purely TM for mode C in agreement with the theory. Spectral position, thermal shift and polarization of mode C confirm it to be a coupled state of the cavity mode and near-field DBR surface-trapped mode.

Spiral magnetic domain structure in cylindrically-shaped microwires.

Identification and characterisation of novel and unusual magnetization states remains a topic of research in modern magnetism. Recently, control of the magnetization state between the surface and volume in cylindrical microwires with the giant magneto-impedance effect has been demonstrated. Herein, the phenomenon of spatial migration of spiral magnetic domains inside a microwire is demonstrated using the magneto-optical Kerr effect. The main properties of the inclined spiral structure were determined, where the surface domain structure possessed a length limited only by actual sample length. Transformation of the structure from a spiral to an elliptical structure could be controlled by external torsion stress. Hysteresis and magnetic images were simulated based on a model assuming a spatial distribution of the internal stress inside the microwire, whose results were consistent with the experimental results. A consistent interpretation of the results in terms of the formation and transformation of the spiral magnetic domain structure is proposed.

Room-temperature yellow-orange (In,Ga,Al)P-GaP laser diodes grown on (n11) GaAs substrates.

We report room temperature injection lasing in the yellow-orange spectral range (599-605 nm) in (AlxGa1-x)0.5In0.5P-GaAs diodes with 4 layers of tensile-strained InyGa1-yP quantum dot-like insertions. The wafers were grown by metal-organic vapor phase epitaxy side-by-side on (811), (211) and (322) GaAs substrates tilted towards the <111> direction with respect to the (100) surface. Four sheets of GaP-rich quantum barrier insertions were applied to suppress leakage of non-equilibrium electrons from the gain medium. Laser diodes having a threshold current densities of ~7-10 kA/cm2 at room temperature were realized for both (211) and (322) surface orientations at cavity lengths of ~1mm. Emission wavelength at room temperature ~600 nm is shorter by ~8 nm than previously reported. As an opposite example, the devices grown on (811) GaAs substrates did not show lasing at room temperature.

Tailoring of magnetoimpedance effect and magnetic softness of Fe-rich glass-coated microwires by stress- annealing.

There is a pressing need for improving of the high-frequency magneto-impedance effect of cost-effective soft magnetic materials for use in high-performance sensing devices. The impact of the stress-annealing on magnetic properties and high frequency impedance of Fe-rich glass-coated microwires was studied. Hysteresis loops of Fe-rich microwires have been considerably affected by stress- annealing. In stress-annealed Fe- rich microwire we obtained drastic decreasing of coercivity and change of character of hysteresis loop from rectangular to linear. By controlling stress-annealing conditions (temperature and time) we achieved drastic increasing (by order of magnitude) of giant magnetoimpedance ratio. Coercivity, remanent magnetization, diagonal and of-diagonal magnetoimpedance effect of Fe-rich microwires can be tuned by stress-annealing conditions: annealing temperature and time. Observed experimental results are discussed considering relaxation of internal stresses, compressive "back-stresses" arising after stress annealing and topological short range ordering.

Magnetic and structural properties of glass-coated Heusler-type microwires exhibiting martensitic transformation.

We have studied magnetic and structural properties of the Heusler-type Ni-Mn-Ga glass-coated microwires prepared by Tailor-Ulitovsky technique. As-prepared sample presents magnetoresistance effect and considerable dependence of magnetization curves (particularly magnetization values) on magnetic field attributed to the magnetic and atomic disorder. Annealing strongly affects the temperature dependence of magnetization and Curie temperature of microwires. After annealing of the microwires at 973 K, the Curie temperature was enhanced to about 280 K which is beneficial for the magnetic solid state refrigeration. The observed hysteretic anomalies on the temperature dependences of resistance and magnetization in the as-prepared and annealed samples are produced by the martensitic transformation. The magnetoresistance and magnetocaloric effects have been investigated to illustrate a potential technological capability of studied microwires.

Stability of charged density waves in InAs nanowires in an external magnetic field.

We report on magnetotransport measurements at [Formula: see text] K in a high-quality InAs nanowire ([Formula: see text] kΩ) in the presence of the charged tip of an atomic force microscope serving as a mobile gate. We demonstrate the crucial role of the external magnetic field on the amplitude of the charge density waves with a wavelength of 0.8 µm. The observed suppression rate of their amplitude is similar or slightly higher than the one for weak localization correction in our investigated InAs nanowire.