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In today's information-driven society, the amount of generated and processed data is constantly increasing, requiring continuous advancements and refinements of memory components. With global digitalization, there is an urgent need for data storage devices meeting specific criteria: they should be energyefficient and compact, possess high capacity, and rapid information read/write rates, while being sustainable and made of recyclable materials. In this context, metal--organic frameworks (MOFs) could become efficient alternative materials for memory device creation due to their simple synthesis, scalability, and low energy consumption. The fabrication process for MOF-based memory elements is straightforward and efficient. Here we propose MOFs (HKUST-1) synthesis using an innovative approach based on droplet microfluidics that allows MOFs synthesis in 32 s, which can be used for further fabrication of memory elements. After revealing optimized experimental synthesis conditions by numerical simulation of droplet formation in a channel of a microfluidic chip, we obtain HKUST-1 microcrystals of various crystallinities and sizes by adjusting the reaction temperature and flow rates. We conduct a thorough structural and optical investigation of the resulting HKUST-1 microcrystals, which we further deposit on a conductive platform to form a memristive element. The memory device made from MOF microcrystals developed using droplet microfluidics demonstrates a higher ON/OFF ratio and faster fabrication compared to conventionally synthesized MOFs. [ABSTRACT FROM AUTHOR]

Context. Two millisecond pulsars, PSR J1513−2550 and PSR J2017−1614, with spin periods of about 2.1 and 2.3 ms were recently discovered in the radio and γ-rays and classified as black widow pulsars in tight binary stellar systems with orbital periods of about 4.3 and 2.3 h. Aims. Our goals are to reveal the fundamental parameters of both systems and their binary components using multi-wavelength observations. Methods. We carried out the first time-series multi-band optical photometry of the objects with the 2.1-m telescope of the Observatorio Astronómico Nacional San Pedro Mártir, the 6.5-m Magellan-1 telescope, and the 10.4-m Gran Telescopio Canarias. To derive the parameters of both systems, we fitted the obtained light curves with a model assuming heating of the companion by the pulsar. We also analysed archival X-ray data obtained with the XMM-Newton observatory. Results. For the first time, we firmly identified J1513−2550 in the optical and both pulsars in X-rays. The optical light curves of both systems have a single peak per orbital period with a peak-to-peak amplitude of ≳2 magnitudes. The J2017−1614 light curves are symmetric, while J1513−2550 demonstrates strong asymmetry whose nature remains unclear. Conclusions. We constrained the orbital inclinations, pulsar masses, companion temperatures and masses, and the distances to both systems. We also conclude that J2017−1614 may contain a massive neutron star of 2.4 ± 0.6 M⊙. The X-ray spectra of both sources can be fitted by power laws with parameters typical of black widow systems. [ABSTRACT FROM AUTHOR]

Hyperthermia plays a significant role in cancer treatment by inducing cell damage through temperature elevation, often used alongside other treatment modalities. During hyperthermia therapy, temperature control is crucial. Here, we report on a simple synthesis route of hybrid plasmonic nanodiamonds either completely wrapped with an Au shell (NV@Au) or densely covered with Au NPs (NV@SiO2@Au). Such integration of nanodiamonds with Au NPs is advantageous both for heating and precise thermometry at nanoscale. After structural and optical investigations, heating abilities of the obtained plasmonic nanodiamonds were thoroughly inspected on glass, in association with living cells, and in tissue slices ex vivo, revealing their effective heat generation under excitation with light using a single excitation source. The developed hybrid plasmonic nanodiamonds were finally applied for local photothermal therapy of melanoma in vivo, demonstrating their efficacy in eradicating cancer cells and monitoring temperature during the process. [ABSTRACT FROM AUTHOR]

We have carried out multiwavelength spectroscopic and photometric studies of the object SRGe J194401.8+284452 (2RXS J194401.4+284456, XMMSL2 J194402.0+284451, 2SXPS J194401.7+284450), the brightest X-ray source in the position uncertainty ellipse of the unidentified gamma-ray source 4FGL J1943.9+2841, with the goal of determining its nature and the possible association with the gamma-ray source. The object is shown to be a cataclysmic variable with an orbital period of about 1.5 h and clear evidence for the presence of an accretion disk around the white dwarf. It can be classified by its properties as an intermediate polar whose association with the gamma-ray source is unlikely. SRGe J194401.8+284452 exhibits abrupt transitions between its high and low luminosity states simultaneously in the optical and X-ray bands, which remain relatively stable on time scales of several months/years. This may be related to the change in the accretion rate by an order of magnitude. We have obtained constraints on the mass (0.3–0.9 ) and temperature ( K) of the accreting white dwarf in the low state, the mass of the donor star (), and the orbital inclination of the binary system (). In the low state we have detected an 8-min brightness variability in the optical band that is most likely related to the white-dwarf spin and not to the nonradial pulsations. In the high state we have revealed stochastic brightness variations on time scales of 1–15 min with amplitudes of 0.2– . SRGe J194401.8+284452 replenishes the small group of intermediate polars with the shortest orbital periods lying below the gap in the period distribution of these systems and exhibiting transitions between the states with high and low accretion rates. The brightness of the source at a level of in the 2000–8000 Å range and erg s cm in the range 0.3–10 keV makes it an interesting object for a detailed study of the physics of such systems. [ABSTRACT FROM AUTHOR]

Technology-assisted dietary assessment has the potential to improve the accuracy of self-reported dietary intake. This study evaluates MealScan3D (MS3D), a mobile device-based food recording system, which uses three-dimensional images to obtain food volumes and an application to capture algorithm-driven food intake data. Participants (n = 179) were randomly assigned and trained to record three meals using either MS3D or a written food record (WFR). Generous amounts of standardized meals were provided, and participants self-selected portions for each food. The weights of provided and uneaten/leftover foods were used to determine true intake. For total energy intake (three meals combined), validity (Pearson correlation) was significantly higher for MS3D vs. the WFR (p < 0.001); when interpreted as the percentage of variance in energy intake explained, MS3D explained 84.6% of true variance, a 25.3% absolute and 42.6% relative increase over the 59.3% explained by the WFR. For 9 of 15 individual foods, the Pearson correlations between true and reported portion size estimates were significantly larger for MS3D than the WFR. Bias was smaller (intercepts were closer to the means) for 9 of 15 foods and the regression coefficients for 10 of 15 foods were significantly closer to 1.0 in the MS3D arm. MS3D is feasible for dietary assessment and may provide improvements in accuracy compared to WFRs. [ABSTRACT FROM AUTHOR]

It was found that in the region of the percolation threshold, depending on the dominance of one or another conduction mechanism, the temperature dependence of the specific volume resistivity ρ(T) of the polymer composite based on a matrix of ethylene vinyl acetate is significantly transformed. With an increase in the CB content, there is a decrease by several orders of magnitude in the maximum value of the relative resistivity ρ(T)max/ρ20 in its temperature dependence. Peroxide crosslinking of matrix macromolecules leads to a change in the nature of the temperature dependence of resistivity. [ABSTRACT FROM AUTHOR]

An unidentified γ-ray source 4FGL J1838.2+3223 has been proposed as a pulsar candidate. We present optical time-series multiband photometry of its likely optical companion obtained with the 2.1-m telescope of Observatorio Astronómico Nacional San Pedro Mártir, Mexico. The observations and the data from the Zwicky Transient Facility revealed the source brightness variability with a period of ≈4.02 h likely associated with the orbital motion of the binary system. The folded light curves have a single sine-like peak per period with an amplitude of about three magnitudes accompanied by fast sporadic flares up to one magnitude level. We reproduce them modelling the companion heating by the pulsar. As a result, the companion side facing the pulsar is strongly heated up to 11300 ± 400 K, while the temperature of its back side is only 2300 ± 700 K. It has a mass of 0.10 ± 0.05 M⊙ and underfills its Roche lobe with a filling factor of |$0.60^{+0.10}_{-0.06}$|⁠. This implies that 4FGL J1838.2+3223 likely belongs to the 'spider' pulsar family. The estimated distance of ≈3.1 kpc is compatible with Gaia results. We detect a flare from the source in X-rays and ultraviolet using Swift archival data and another one in X-rays in the eROSITA all-sky survey. Both flares have X-ray luminosity of ∼1034 erg s−1 which is two orders of magnitude higher than the upper limit in quiescence obtained from eROSITA assuming spectral shape typical for spider pulsars. If the spider interpretation is correct, these flares are among the strongest observed from non-accreting spider pulsars. [ABSTRACT FROM AUTHOR]

PSR J1641+8049 is a 2 ms black widow pulsar with the 2.2 h orbital period detected in the radio and γ-rays. We performed new phase-resolved multiband photometry of PSR J1641+8049 using the OSIRIS instrument at the Gran Telescopio Canarias. The obtained data were analysed together with the new radio-timing observations from the Canadian Hydrogen Intensity Mapping Experiment (CHIME), the X-ray data from the Spectrum-RG/ eROSITA all-sky survey, and all available optical photometric observations. An updated timing solution based on CHIME data is presented, which accounts for secular and periodic modulations in pulse dispersion. The system parameters obtained through the light-curve analysis, including the distance to the source 4.6–4.8 kpc and the orbital inclination 56–59 deg, are found to be consistent with previous studies. However, the optical flux of the source at the maximum brightness phase faded by a factor of ∼2 as compared to previous observations. Nevertheless, the face of the J1641+8049 companion remains one of the most heated (8000–9500 K) by a pulsar among the known black widow pulsars. We also report a new estimation on the pulsar proper motion of ≈2 mas yr−1, which yields a spin-down luminosity of ≈4.87 × 1034 erg s−1 and a corresponding heating efficiency of the companion by the pulsar of 0.3–0.7. The pulsar was not detected in X-rays implying its X-ray-luminosity was |$\lesssim$| 3 × 1031 erg s−1 at the date of observations. [ABSTRACT FROM AUTHOR]

Atomic layer deposition (ALD) is widely utilized in the modern microelectronic industry due to its capability of depositing thin films with exceptional conformality and uniformity. The first Russian ALD system Izofaz TM 200-01 has already been successfully employed in the deposition of various materials, particularly high-k dielectrics such as aluminum oxide. This study presents the computer modeling-based investigation of the ALD process for hafnia and zirconia oxide films using the aforementioned ALD system. The growth per cycle was determined to be 1.1 Å/cycle, while the within-wafer nonuniformity was measured to be 1.2% or lower. These results are consistent with previously reported results and, more importantly, with experimental results also collected in this work, and demonstrate a high level of quality. Additionally, the electrical and physical properties of hafnia oxide films, including their potential application in ReRAM-like structures, were investigated. The storage elements based on hafnia oxide exhibited stable performance over 3 million switching cycles. Consequently, the Izofaz TM 200-01 ALD system has been proven effective in the deposition of thin films composed of hafnia and zirconia oxides. [ABSTRACT FROM AUTHOR]

Demonstrated the influence of buffer layers of group IVB oxides on the electrophysical characteristics of ferroelectric memory storage elements with a hafnium oxide functional layer. Thin films of buffer and functional layers were deposited by plasma-enhanced atomic layer deposition using the Russian system "Izofaz TM-200K-01." It was experimentally found that the introduction of thin-film buffer layers reduces the drop in the value of residual polarization after heating. Zirconium oxide buffer layers positively effect of the memory window of the storage element, and titanium oxide buffer layer allows reducing the influence of the imprint effect and increasing the value of the remnant polarization and switching endurance. [ABSTRACT FROM AUTHOR]

Among numerous optical sensing techniques, lifetime analysis of fluorescent agents has several advantages, including high responsivity to local environmental changes and reduced susceptibility to random light-scattering events during through-tissue imaging. Monitoring ion concentrations in blood vessels is among the applications for which fluorescent approaches can be particularly beneficial. However, without additional biochemical conjugation approaches, fluorescent agents lack specificity; namely, they are either weakly sensitive to salt concentrations or provide a strong nonspecific response. Here we demonstrate the efficacy of phenylenediamine carbon dots exhibiting a strong fluorescence lifetime response to the common microelements in blood such as Fe2+, Fe3+, and Co2+ ions while remaining insusceptible to Na2+, Ca2+, Mn2+, Mg2+, Zn2+, and Ni2+ ions. The paper also discusses the physical mechanisms underlying the observed selective sensitivity of the obtained CDs. Sensing performances of the carbon dots were also demonstrated with model cells on pathways to in vivo applications. [ABSTRACT FROM AUTHOR]

The influence of temperature on the electrophysical characteristics of polymer composites based on a matrix of ethylene vinyl acetate filled with carbon black (CB) is investigated. It is established that the most noticeable transformation of the temperature dependences of the resistivity ρ(T) after the first heating–cooling cycle occurs in composite samples saturated with peroxide. Saturation of the composite with peroxide and the crosslinking of macromolecules leads to the N-shaped character of the dependence ρ(T). The occurrence of hysteresis ρ(T) and its character indicate that in the studied composites, the process of crystallization of the polymer matrix has significantly less effect on the destruction of the conductive mesh formed as a result of agglomeration of CB particles compared with the processes accompanying melting. [ABSTRACT FROM AUTHOR]

The γ-ray source 4FGL J2054.2+6904 discovered with Fermi was recently classified as a pulsar candidate. Its possible X-ray and optical counterpart was identified with Swift. Using Zwicky survey data we show that the counterpart is variable in the optical with the period of about 7.5 h. The shape of the light curve is almost sinusoidal with the amplitude of ≈0.5m. The spectral energy distribution corresponds to the stellar spectrum with the effective temperature of 5820 ± 410 K. We also firmly detected the source in X-rays using the SRG/eROSITA all sky survey data. Its X-ray spectrum can be described by a power law with the photon index of about 1.0 and unabsorbed flux ≈2 × 10–13 erg/(s cm2) in the 0.5–10 keV range. These results show that 4FGL J2054.2+6904 is a promising candidate to a millisecond pulsar in a close binary system of the "redback" type. [ABSTRACT FROM AUTHOR]

Heat is a well-known treatment method for a wide range of diseases. Hyperthermia treatment or intentional overheating of cells is a rapidly developing therapeutic strategy in cancer treatment. All-dielectric nanophotonics has established itself in optical applications, including nanothermometry and optical heating; generally, it involves Mie resonances in nonplasmonic nanoparticles (NPs). However, such nanomaterials do not always provide sufficient heating due to their nonoptimal size distribution after fabrication by nonlithographic approaches. To overcome this limitation, additional steps, such as size-separation of NPs, are required. Another strategy for efficient heating is intelligent integration of plasmonic and all-dielectric nanostructures to develop hybrid nanomaterials with outstanding optical performances, e.g., efficient nanoheaters and nanothermometers. Taking this into account, we report on a simple and accessible approach for the fabrication of hybrid silicon–gold NPs. Their heating abilities are further compared with those of pristine monodispersed Si NPs inside and outside B16–F10 melanoma cells and confirmed by simultaneous nanoscale thermometry. The obtained results show that the obtained hybrid nanomaterials are more efficient nanoheaters even in biological environments, where cell inhomogeneity and deviations of NP sizes make it difficult to exactly meet the critical coupling conditions. [ABSTRACT FROM AUTHOR]

We present the results of optical spectroscopy of stellar companions to three binary millisecond pulsars, PSRs J0621+2514, J2317+1439, and J2302+4442, obtained with the Gran Telescopio Canarias. The spectrum of the J0621+2514 companion shows a blue continuum and prominent Balmer absorption lines. The latter are also resolved in the spectrum of the J2317+1439 companion, showing that both are DA-type white dwarfs. No spectral features are detected for the J2302+4442 companion; however, its broad-band magnitudes and the spectral shape of the continuum emission imply that this is also a DA-type white dwarf. Based on the spectral analyses, we conclude that the companions of J0621+2514 and J2317+1439 are relatively hot, with effective temperatures T eff = 8600 ± 200 and 9600 ± 2000 K, respectively, while the J2302+4442 companion is significantly cooler, T eff<6000 K. We also estimated the distance to J0621+2514 of 1.1 ± 0.3 kpc and argue that its companion and the companion of J2317+1439 are He-core white dwarfs providing constraints on their cooling ages of |$\lesssim$| 2 Gyr. [ABSTRACT FROM AUTHOR]

The Fermi catalogue contains about 2000 unassociated γ-ray sources. Some of them were recently identified as pulsars, including so-called redbacks and black widows, which are millisecond pulsars in tight binary systems with non- and partially-degenerate low-mass stellar companions irradiated by the pulsar wind. We study a likely optical and X-ray counterpart of the Fermi source 4FGL J2054.2+6904 proposed earlier as a pulsar candidate. We use archival optical data as well as Swift /XRT and SRG / eROSITA X-ray data to clarify its nature. Using Zwicky Transient Facility data in g and r bands spanning over 4.7 yr, we find a period of ≈7.5 h. The folded light curve has a smooth sinusoidal shape with the peak-to-peak amplitude of ≈0.4 mag. The spectral fit to the optical spectral energy distribution of the counterpart candidate gives the star radius of 0.5 ± 0.1 R⊙ and temperature of 5500 ± 300 K implying a G2–G9-type star. Its X-ray spectrum is well fitted by an absorbed power law with the photon index of 1.0 ± 0.3 and unabsorbed flux of ≈2 × 10−13 erg s−1 cm−2. All the properties of 4FGL J2054.2+6904 and its presumed counterpart suggest that it is a member of the redback family. [ABSTRACT FROM AUTHOR]

Proteolytic activity is pivotal in maintaining cell homeostasis and function. In pathological conditions such as cancer, it covers a key role in tumor cell viability, spreading to distant organs, and response to the treatment. Endosomes represent one of the major sites of cellular proteolytic activity and very often represent the final destination of internalized nanoformulations. However, little information about nanoparticle impact on the biology of these organelles is available even though they represent the major location of drug release. In this work, we generated albumin nanoparticles with a different resistance to proteolysis by finely tuning the amount of cross-linker used to stabilize the carriers. After careful characterization of the particles and measurement of their degradation in proteolytic conditions, we determined a relationship between their sensitivity to proteases and their drug delivery properties. These phenomena were characterized by an overall increase in the expression of cathepsin proteases regardless of the different sensitivity of the particles to proteolytic degradation. [ABSTRACT FROM AUTHOR]

The ballistic characteristics of energy systems based on hydroxylammonium salts of nitroamine derivatives of some polynitrogen fused heterocycles are considered. The quantitative dependences of the energy parameters of such systems on the properties of the studied compound (the main filler), the proportion of aluminum, the presence of additional oxidizing agents in the composition, and the type of binder are established. All the considered compounds (I–V) outperform the classical energy components in the class of composite propellants (CPs) without condensed combustion products. The most effective component is dihydroxylammonium salt (E)-1,2-bis(3-nitroamino-[1,2,4]triazolo[4,3-b][1,2,4,5]tetrazin-6-yl)diazene (V), which significantly exceeds many of the known components in terms of the value of the effective impulse in the third stage (Ief(3) = 279.7 s). However, when using a more realistic value of the enthalpy of the formation of compound V (according to our estimate) in the calculations, the indicator for the composition based on compound V dropped to 266.8 c, and the dihydroxylammonium salt of 1,4-bis(nitroamino)-3,6-dinitropyrazolo[4,3-c]pyrazole (I) with Ief(3) = 267.8 s performed the best. [ABSTRACT FROM AUTHOR]

Halide perovskite structures of submicrometer sizes have become outstanding tools for various applications in photonics. However, despite the high potential of perovskites, their stable, scalable, and reproducible synthesis with a fine control over the size of the resulting structures (a narrow size distribution) is still challenging. In this work, we report on the synthesis of all-inorganic lead halide perovskites via droplet microfluidics, where a formed droplet acts as a sealed microreactor for perovskites' nucleation and growth. For synthesis, we use two systems with different carrier fluids (either fluorinated oil or distilled water). The developed microfluidic system enables the fabrication of perovskite particles with sizes ranging from nanometers to submicrometers with a narrow size distribution, which depends on temperature and hydrophilic-lipophilic balance. Using the advantages of this synthesis method, we obtain optically resonant submicrometer cuboid particles. We study their lasing properties upon two-photon nonlinear excitation on a metallic substrate and reveal a significant reduction of the lasing threshold down to around 230 μJ/cm2 when the pump wavelength λ corresponds to the first-order Mie resonance of the particle (at λ = 950 nm for the particle dimensions 440 × 640 × 710 nm3). Our results can be useful for the development of infrared laser beam visualizers and nonlinear imaging. [ABSTRACT FROM AUTHOR]

One of the core questions in Neuro‐economics is to determine where value is represented. To date, most studies have focused on simple options and identified the ventromedial prefrontal cortex (VMPFC) as the common value region. We report the findings of an fMRI study in which we asked participants to make pairwise comparisons involving options of varying complexity: single items (Control condition), bundles made of the same two single items (Scaling condition) and bundles made of two different single items (Bundling condition). We construct a measure of choice consistency to capture how coherent the choices of a participant are with one another. We also record brain activity while participants make these choices. We find that a common core of regions involving the left VMPFC, the left dorsolateral prefrontal cortex (DLPFC), regions associated with complex visual processing and the left cerebellum track value across all conditions. Also, regions in the DLPFC, the ventrolateral prefrontal cortex (VLPFC) and the cerebellum are differentially recruited across conditions. Last, variations in activity in VMPFC and DLPFC value‐tracking regions are associated with variations in choice consistency. This suggests that value based decision‐making recruits a core set of regions as well as specific regions based on task demands. Further, correlations between consistency and the magnitude of signal change with lateral portions of the PFC suggest the possibility that activity in these regions may play a causal role in decision quality. [ABSTRACT FROM AUTHOR]

Because of their high biocompatibility, biological barrier negotiation, and functionalization properties, biological nanoparticles have been actively investigated for many medical applications. Biological nanoparticles, including natural extracellular vesicles (EVs) and synthetic extracellular vesicle–mimetic nanovesicles (EMNVs), represent novel drug delivery vehicles that can accommodate different payloads. In this study, we investigated the physical, biological, and delivery properties of EVs and EMNVs and analyzed their ability to deliver the chemotherapeutic drug doxorubicin. EMNVs and EVs exhibit similar properties, but EMNVs are more effectively internalized, while EVs show higher intracellular doxorubicin release activity. In addition, these nanotherapeutics were investigated in combination with the FDA-approved drug hydroxychloroquine (HCQ). We demonstrate that HCQ-induced lysosome destabilization and could significantly increase nanoparticle internalization, doxorubicin release, and cytotoxicity. Altogether, these data demonstrate that, from the delivery standpoint in vitro, the internalization of EMNVs and EVs and their payload release were slightly different and both nanotherapeutics had comparable cytotoxic performance. However, the synthesis of EMNVs was significantly faster and cost-effective. In addition, we highlight the benefits of combining biological nanoparticles with the lysosome-destabilizing agent HCQ that increased both the internalization and the cytotoxic properties of the particles. [ABSTRACT FROM AUTHOR]

This work is devoted to the comparison of one- (1-D) and zero-dimensional (0-D) models of sea ice thermodynamics. 1-D thermodynamics solvers imply the solution of the diffusion equation with penetrating radiation in the moving domain (moving boundary problem), while 0-D implementations neglect the heat capacity of ice and penetrating radiation, that leads to a linear temperature profile by the construction. So far, some climate models use 0-D implementation of thermodynamics in a block of sea ice, while other models use 1-D implementation with a small number of nodes. In this work we present our fully implicit 0-D and 1-D version of snow–ice thermodynamics, which relieves the model of Courant-type time step constraints. Implicitness is achieved by the relaxation method for nonlinear heat capacity and thermal conductivity coefficients with simultaneous search for the temperature that satisfies the boundary conditions. We introduce the experiment with analytical forcing to compare evolution of temperature profiles. This model experiment shows that 0-D model underestimates ice thickness and overestimates the amplitude of temperature profile variation compared to 1-D solution. Despite the large differences in thickness and internal temperatures, the surface temperatures are very close. The models were also validated on the data of the SHEBA field experiment. According to comparison with observation data, the 0-D model predicts ice thickness and spatiotemporal temperature distribution much worse compared to 1-D model, but the amplitude of error in surface temperature is slightly greater for 0-D code. It can be concluded that 0-D model of sea ice thermodynamics is a good tool for predicting surface temperature, but it gives a large error in thickness and temperature distribution. [ABSTRACT FROM AUTHOR]

The thermal decomposition of 1,1-bis(methoxy-NNO-azoxy)-3-nitro-3-azabutane is studied under isothermal and nonisothermal conditions. The heats of its melting and thermal decomposition are 29.1 kJ/mol (7.0 kcal/mol) and 387 kJ/mol (92.5 kcal/mol), respectively. The composition of gaseous products of thermal decomposition is analyzed. The reaction takes place autocatalytically. The reaction center in the molecule of the studied substance is the diazene oxide group. The mechanism of the process is proposed. The limiting stage of the reaction includes a five-membered cyclic transition state. [ABSTRACT FROM AUTHOR]

Nanostructures enabling light manipulation in response to external stimuli offer unprecedented opportunities for efficient control over optomechanical systems at the nanoscale. The integration of stimuli‐responsive materials in such systems is an important milestone in the creation of miniaturized and smart nano‐ and micromechanical systems. In this article, a thermally sensitive mechanically driven platform based on pNIPAM microspheres modified with high refractive index dielectric silicon (Si) and plasmonic gold (Au) nanoparticles is presented to probe the temperature‐dependent reversible mechanical transformations through the second‐harmonic generation signal switching. The second‐harmonic generation process is investigated theoretically and experimentally depending on the applied temperature and pNIPAM phase. It is found that the change of the interparticle distance in the system during the phase transition provokes generation of optically induced static electric field probed by the second‐harmonic generation signal. The obtained results can become the foundation in the creation of nanophotonic devices based on thermo‐sensitive polymers, as they combine reversible tuning of optical signals with the opportunity of local probing of mechanical changes. [ABSTRACT FROM AUTHOR]

The energy and ballistic characteristics of model solid composite propellants (SCPs) based on some azido- and nitro-derivatives of N,N'-azoazoles are considered. The quantitative dependences of the energy parameters of the propellants on the properties of the compound under consideration (the main filler), the fractions of aluminum and additional oxidants in the composition, and the type of binder are established. The most effective component turns out to be 1,2-bis(3,5-dinitro-1H-1,2,4-triazol-1-yl)diazen (I) in a composition without aluminum with a mixture of an active and hydrocarbon binder in a ratio of 1.9 : 1. In the class of SCP compositions without condensed combustion products, compound I significantly exceeds many of the known components in terms of the effective impulse in the third stage (268.5 s). [ABSTRACT FROM AUTHOR]

The kinetics of thermal decomposition of 1-(2,2-bis(methoxy-NNO-azoxy)ethyl)pyrazole (I) is studied in the isothermal and nonisothermal modes and a conclusion is made about the possible mechanism of this reaction. The heats of melting and thermal decomposition of I are found to be –153.4 J/g (‒9.0 kcal/mol) and 494.3 J/g (28.8 kcal/mol), respectively. Thermal decomposition of I in open and closed reaction systems proceeds in different ways. In an open system, the rate of the process decreases monotonically in accordance with the kinetic law of the order of 0.5. In a closed system, the reaction proceeds with self-acceleration and is described by the autocatalysis equation with the second kinetic order on the autocatalyst. A decomposition mechanism is proposed, according to which the first stage of the reaction proceeds through a cyclic five-membered transition state. In addition, the reaction is susceptible to autocatalysis, mainly by volatile products, among which pyrazole seems to play the most important role. The autocatalysis is of a basic nature. [ABSTRACT FROM AUTHOR]

Simple Summary: Understanding of the interactions of chemotherapeutic agents with cancer cells in the presence of extracellular matrix (ECM) is necessary for improving drug delivery and treatment efficacy. In this study, using 3D collagen-based models, microfluidic devices, and multiphoton fluorescence microscopy, we visualized delivery of doxorubicin in ECM and its effects on cellular metabolism. We found that collagen, especially unstructured, plays a protective role for cancer cells because it impedes the delivery of the drug and changes cellular metabolic status to a more glycolytic status. The direct effect of the drug on mitochondria also contributes to its higher cytotoxicity in the absence of collagen. These results suggest that modification of ECM structure can be a potential strategy for improving efficacy of chemotherapy with doxorubicin. The extracellular matrix (ECM) plays an important role in regulation of many aspects of tumor growth and response to therapies. However, the specifics of the interaction of chemotherapeutic agents with cancer cells in the presence of collagen, the major component of ECM, is still poorly investigated. In this study, we explored distribution of doxorubicin (DOX) and its effects on cancer cells' metabolism in the presence of collagen with different structures in 3D models. For this, a combination of second harmonic generation imaging of collagen and multiphoton fluorescence microscopy of DOX, and metabolic cofactor NAD(P)H was used. It was found that collagen slowed down the diffusion of DOX and thus decreased the cellular drug uptake. Besides nuclei, DOX also targeted mitochondria leading to inhibition of oxidative phosphorylation, which was more pronounced in the cells growing in the absence of collagen. As a result, the cells in collagen displayed better viability upon treatment with DOX. Taken together, our data illustrate that tumor collagen contributes to heterogeneous and sub-optimal response to DOX and highlight the challenges in improving drug delivery and efficacy. [ABSTRACT FROM AUTHOR]

Superconductivity in a conducting material with a dilute array negative-U sites with strong electron−electron attraction is studied. It is shown that at the attraction exceeding a certain threshold value, Cooper pairs arise at the sites. At low temperatures, a global coherent superconducting state emerges due to the intersite Andreev scattering. The dependences of the superconducting transition temperature and of the second critical magnetic field on the magnitude of attraction are calculated. [ABSTRACT FROM AUTHOR]

The use of three-dimensional (3D) printing for fabrication of master molds for microfluidic devices is very attractive due to its availability and simplicity and replaces the standard methods of soft lithography. However, the commercially available photopolymer resins inhibit the curing of polydimethylsiloxane (PDMS), preventing reliable replication of 3D printed master mold structures. Here, we present a simple and safe method to post-process 3D printed photopolymer master molds for PDMS microfluidic devices. This approach expands the possibilities of prototyping microfluidic PDMS devices for a wider research community without complex post-processing tools currently required for fabrication of 3D photopolymer master molds. [ABSTRACT FROM AUTHOR]

XMM–Newton observations of the middle-aged radio-quiet γ-ray pulsar J0554+3107 allowed us, for the first time, firmly identify it in X-rays by detection of pulsations with the pulsar period. In the 0.2–2 keV band, the pulse profile shows two peaks separated by about a half of the rotation phase with the pulsed fraction of 25 ± 6 per cent. The profile and spectrum in this band can be mainly described by thermal emission from the neutron star with the hydrogen atmosphere, dipole magnetic field of ∼1013 G, and non-uniform surface temperature. Non-thermal emission from the pulsar magnetosphere is marginally detected at higher photon energies. The spectral fit with the atmosphere+power-law model implies that J0554+3107 is a rather heavy and cool neutron star with the mass of 1.6–2.1 M⊙, the radius of ≈13 km, and the redshifted effective temperature of ≈50 eV. The spectrum shows an absorption line of unknown nature at ≈350 eV. Given the extinction–distance relation, the pulsar is located at ≈2 kpc and has the redshifted bolometric thermal luminosity of ≈2 × 1032 erg s−1. We discuss cooling scenarios for J0554+3107 considering plausible equations of state of superdense matter inside the star, different compositions of the heat-blanketing envelope, and various ages. [ABSTRACT FROM AUTHOR]

The thermolysis mechanism of two members of the 2‐alkoxydiazene‐1‐oxide class of compounds – 1‐methyl‐2‐methoxydiazene‐1‐oxide (1) and 2‐methoxy‐1‐neopentyldiazene‐1‐oxide (2) was studied by quantum chemical methods. Calculations were performed using coupled clusters method at the CCSD and CCSD(T) level using the aug‐cc‐pVDZ and aug‐cc‐pVTZ basis sets. It was shown that the mechanism of thermal decomposition of compounds 1 and 2 is similar and occurs via two competing channels – via homolytic N‐OCH3 bond cleavage and via intramolecular nucleophilic substitution at the methoxyl carbon atom. The calculated values of the activation enthalpies for both compounds are close (ΔНа‡ is in the range of 200–210 kJ/mol) and practically coincide with the experimental activation energies obtained earlier. The main thermolysis products predicted theoretically correspond to the thermal decomposition products of compounds 1 and 2 that have been observed experimentally. [ABSTRACT FROM AUTHOR]

The energy and ballistic characteristics of solid composite propellants (SCPs) based on 3,6-dinitro-1,4-bis(trinitromethyl)-1,4-dihydropyrazolo[4,3-c]pyrazole (II) are compared with three N-trinitromethyl biazole derivatives. Of the four oxidizing agents considered, compound II turned out to be the most effective compound in a simpled binary formulation with a hydrocarbon binder. The quantitative dependences of the energy parameters of the propellant on the properties of the compound under study (the main filler), the proportion of aluminum and additional oxidizing agents in the formulation, and the type of binder are established. [ABSTRACT FROM AUTHOR]

The thermal decomposition of 1-[2,2-bis(methoxy-NNO-azoxy)ethyl]-3-nitropyrazole (I) in isothermal and nonisothermal conditions is studied using the methods of thermal analysis, manometry, IR spectroscopy, mass spectrometry, and NMR 1H. The heat of the α → β polymorphic transition, the melting heat of β-I, and the heat of thermal decomposition I are 0.4, 6.2, and 79.2 kcal/mol (274 cal/g), respectively. The composition of the reaction products is analyzed. Among the products formed, N2O, H2O, NO2, NO, N2, CH3OH, and 3-nitropyrazole are identified. The kinetics of the thermal decomposition of I is complex and cannot be described by simple equations. The effective activation energies of the reaction are determined to be close to 34–35 kcal/mol and slightly increase with the progress of decomposition. It is concluded that the first stage of the reaction involves the elimination of the methoxydiazene oxide group through a five-membered cyclic transition state. The number of nitro groups attached to the pyrazole ring does not affect the kinetics of the thermal decomposition. [ABSTRACT FROM AUTHOR]

Photothermal therapy (PTT) has attracted increasing interest as a complementary method to be used alongside conventional therapies. Despite a great number of studies in this field, only a few have explored how temperatures affect the outcome of the PTT at nanoscale. In this work, we study the necrosis/apoptosis process of cancerous cells that occurs during PTT, using a combination of local laser heating and nanoscale fluorescence thermometry techniques. The temperature distribution within a whole cell was evaluated using fluorescence lifetime imaging microscopy during laser-induced hyperthermia. For this, gold nanorods were utilized as nanoheaters. The local near-infrared laser illumination produces a temperature gradient across the cells, which is precisely measured by nanoscale thermometry. This allows one to optimize the PTT conditions by varying concentration of gold nanorods associated with cells and laser power density. During the PTT procedure, such an approach enables an accurate determination of the percentages of apoptotic and necrotic cells using 2D and 3D models. According to the performed cell experiments, the influence of temperature increase during the PTT on cell death mechanisms has been verified and determined. Our investigations can improve the understanding of the PTT mechanisms and increase its therapeutic efficiency while avoiding any side effects. [ABSTRACT FROM AUTHOR]

Besides the broad development of nanotechnological approaches for cancer diagnosis and therapy, currently, there is no significant progress in the treatment of different types of brain tumors. Therapeutic molecules crossing the blood–brain barrier (BBB) and reaching an appropriate targeting ability remain the key challenges. Many invasive and non-invasive methods, and various types of nanocarriers and their hybrids have been widely explored for brain tumor treatment. However, unfortunately, no crucial clinical translations were observed to date. In particular, chemotherapy and surgery remain the main methods for the therapy of brain tumors. Exploring the mechanisms of the BBB penetration in detail and investigating advanced drug delivery platforms are the key factors that could bring us closer to understanding the development of effective therapy against brain tumors. In this review, we discuss the most relevant aspects of the BBB penetration mechanisms, observing both invasive and non-invasive methods of drug delivery. We also review the recent progress in the development of functional drug delivery platforms, from viruses to cell-based vehicles, for brain tumor therapy. The destructive potential of chemotherapeutic drugs delivered to the brain tumor is also considered. This review then summarizes the existing challenges and future prospects in the use of drug delivery platforms for the treatment of brain tumors. [ABSTRACT FROM AUTHOR]

The kinetics of thermal decomposition of 1-[2,2-bis(methoxy-NNO-azoxy)ethyl]-3,4-dinitro-1H-pyrazole is studied using isothermal and nonisothermal methods in a wide temperature range. The composition of the gaseous products, the heat of fusion, and the heat of thermal decomposition are determined. Below the melting temperature, the reaction proceeds with pronounced self-acceleration and cannot be described by simple kinetic laws. The effective activation energies of the process, which decrease as the degree of conversion increases, are calculated. The results obtained are explained from the point of view of general ideas about the mechanism of thermal decomposition of solid organic substances. In the liquid phase, the reaction proceeds with weak self-acceleration. The effective activation energies are also determined for the liquid-phase decomposition. It is assumed that the reaction proceeds according to a consecutive mechanism with the intermediate formation of a cyclic product. It is concluded that the studied 1-[2,2-bis(methoxy-NNO-azoxy)ethyl]-3,4-dinitro-1H-pyrazole is highly thermally stable and that the thermal stability of compounds of this class strongly depends on the number of nitro groups in the pyrazole ring. [ABSTRACT FROM AUTHOR]

We report charge and heat transport studies in copper-intercalated topological insulator Bi 2 Se 3 hybrid devices. Measured conductivity shows impact of quantum corrections, electron–electron and electron–phonon interactions. Our shot noise measurements reveal that heat flux displays a crossover between T 2 and T 4 with the increase of temperature. The results might be explained by a model of inelastic electron scattering on disorder, increasing the role of transverse acoustic phonons in the electron–phonon coupling process. [ABSTRACT FROM AUTHOR]

The 840-kyr-old pulsar PSR J1957+5033, detected so far only in γ- and X-rays, is a nearby and rather cool neutron star with a temperature of 0.2–0.3 MK, a distance of |$\lesssim 1$| kpc, and a small colour reddening excess E (B − V) ≈ 0.03. These properties make it an ideal candidate to detect in the optical to get additional constraints on its parameters. We thus performed the first deep optical observations of the pulsar with the 10.4 m Gran Telescopio Canarias in the g ′ band and found its possible counterpart with g ′ = 27.63 ± 0.26. The counterpart candidate position is consistent with the X-ray coordinates of the pulsar within the 0.5 arcsec accuracy. Assuming that this is the real counterpart, we analysed the pulsar X-ray spectrum together with the derived optical flux density. As a result, we found that the thermal emission from the bulk surface of the cooling neutron star can significantly contribute to its optical flux. Our multiwavelength spectral analysis favours the pulsar nature of the detected optical source, since it provides physically adequate parameters of the pulsar emission. We show that the optical data can provide new constraints on the pulsar temperature and distance. [ABSTRACT FROM AUTHOR]

Pulmonary vagal nociceptors defend the airways. Cardiopulmonary vagal nociceptors synapse in the nucleus tractus solitarius (NTS). Evidence has demonstrated the convergence of cardiopulmonary nociceptors with afferents from carotid chemoreceptors. Whether sensory convergence occurs in motor nuclei and how sensory convergence affects reflexive efferent motor output directed toward the airways are critical knowledge gaps. Here, we show that distinct tracer injection into the pulmonary nociceptors and carotid chemoreceptors leads to co-labeled neurons in the nucleus tractus solitarius and nucleus ambiguus. Precise simultaneous stimulation delivered to pulmonary nociceptors and carotid chemoreceptors doubled efferent vagal output, enhanced phrenic pause, and subsequently augmented phrenic motor activity. These results suggest that multiple afferents are involved in protecting the airways and concurrent stimulation enhances airway defensive reflex output. NEW & NOTEWORTHY Sensory afferents have been shown to converge onto nucleus tractus solitarius primary neurons. Here, we show sensory convergence of two distinct sets of sensory afferents in motor nuclei of the nucleus ambiguus, which results in augmentation of airway defense motor output. [ABSTRACT FROM AUTHOR]

Dihydroxylammonium and dihydrazonium salts of 5,5'-azotetrazole-1,1'-diol and dihydroxylammonium salt of 5,5'-bistetrazole-1,1'-diol (TKX-50) are considered as potential components of propellants. The thermodynamic calculations carried out in this study show that some of the described compounds have a good potential for creating solid composite propellants with increased energy characteristics. The quantitative dependences of the energy parameters of the fuel on the properties of the studied compounds—the main filler, the proportion of aluminum in the composition, the type of binder, and the content of the latter—are established. [ABSTRACT FROM AUTHOR]

Featured Application: Results of the work are applied to the design of the fully automatic computer vision system for online asbestos fiber content (productivity) estimation in veins of rock chunks in an open pit. The paper discusses the results of the research and development of an innovative deep learning-based computer vision system for the fully automatic asbestos content (productivity) estimation in rock chunk (stone) veins in an open pit and within the time comparable with the work of specialists (about 10 min per one open pit processing place). The discussed system is based on the applying of instance and semantic segmentation of artificial neural networks. The Mask R-CNN-based network architecture is applied to the asbestos-containing rock chunks searching images of an open pit. The U-Net-based network architecture is applied to the segmentation of asbestos veins in the images of selected rock chunks. The designed system allows an automatic search and takes images of the asbestos rocks in an open pit in the near-infrared range (NIR) and processes the obtained images. The result of the system work is the average asbestos content (productivity) estimation for each controlled open pit. It is validated to estimate asbestos content as the graduated average ratio of the vein area value to the selected rock chunk area value, both determined by the trained neural network. For both neural network training tasks the training, validation, and test datasets are collected. The designed system demonstrates an error of about 0.4% under different weather conditions in an open pit when the asbestos content is about 1.5–4%. The obtained accuracy is sufficient to use the system as a geological service tool instead of currently applied visual-based estimations. [ABSTRACT FROM AUTHOR]

Over the last few decades, nanomaterials have attracted significant attention in diverse applications. Today, a new generation of nanomaterials, which demonstrate tunable physical and chemical properties, is able to address modern challenges in personalized medicine, adaptive optics and smart chemistry. Here, a special class of such nanomaterials – biointegrated nanoparticle‐polymer complexes and their ensembles with tunable optical properties are reviewed. Key aspects of the design and synthesis of such complexes exhibiting dynamic structural changes to different external and internal stimuli (e.g., light, chemical, temperature, electric/magnetic fields and others) are discussed. Consequently, these changes allow one to tune the optical response in reversible or irreversible manner. The application of such complexes is considered as functional adaptive elements for optical filters, sensors, Bragg mirrors, artificial muscles, and drug delivery. The current state and the perspectives of further development of this research area are discussed. [ABSTRACT FROM AUTHOR]

The energetic capabilities of three energy-intensive components containing furoxan cycles and azo groups are studied. These compounds are assessed as the main fillers of composite solid rocket fuels. It is shown that the energy efficiency of the considered compounds increases in the following order: 3,3'‑di(4-nitrofuroxan-3-yl)-5,5'-azo-1,2,4-oxadiazole (I) < (Z)-tris ([1,2,5]oxadiazolo)[3,4-c:3',4'-e:3'',4''-g][1,2]diazocine 1,4,11-trioxide (III) < 4,4'-dinitro-3,3'-azofuroxan (II). [ABSTRACT FROM AUTHOR]

The heat release kinetics in thermally initiated polymerization of 1,4-diethynylbenzene suggested as fuel dispersant in gas generator engines was studied under isothermal conditions in the temperature interval 90–150°С in the melt–vapor two-phase closed system. The enthalpies and entropies of melting, vaporization, and sublimation of 1,4-diethynylbenzene and the kinetics of a decrease in its vapor pressure in the course of polymerization in the melt were determined. Specific features of pressure and temperature variation in the course of propagation of the 1,4-diethynylbenzene combustion front in a cylindrical specimen in a Crawford bomb at the initial pressure of 2 MPa were studied. [ABSTRACT FROM AUTHOR]

The energy capabilities of five real-life high-enthalpy derivatives of 1,2,4,5-tetrazine N-oxides as components composite solid rocket propellants (CSRPs), which do not contain metallic fuel, are considered. Various ways of reducing the combustion temperature of CSRPs to an acceptable value, if necessary, are studied. [ABSTRACT FROM AUTHOR]