Pi-conjugated dendrimers are molecular examples of tree-like structures known in physics as Bethe lattices. Electronic excitations in these systems can be spatially delocalized or localized depending ...on the branching topology. Without a priori knowledge of the localization pattern, understanding photoexcitation dynamics reflected in experimental optical spectra is difficult. 'Supramolecular'-like quantum-chemical calculations quickly become intractable as the molecular size increases. Here we develop a reduced exciton-scattering (ES) model, which attributes excited states to standing waves in quasi-one-dimensional structures, assuming a quasiparticle picture of optical excitations. Direct quantum-chemical calculations of branched phenylacetylene chromophores are used to verify our model and to derive relevant parameters. Complex and non-trivial delocalization patterns of photoexcitations throughout the entire molecular tree can then be universally characterized and understood using the proposed ES method, completely bypassing 'supramolecular' calculations. This allows accurate modelling of excited-state dynamics in arbitrary branched structures. PUBLICATION ABSTRACT
Forest fires have a negative impact on the economy in a number of regions, especially in Wildland Urban Interface (WUI) areas. An important link in the fight against fires in WUI areas is the ...development of information and computer systems for predicting the fire safety of infrastructural facilities of Russian Railways. In this work, a numerical study of heat transfer processes in the enclosing structure of a wooden building near the forest fire front was carried out using the technology of parallel computing. The novelty of the development is explained by the creation of its own program code, which is planned to be put into operation either in the Information System for Remote Monitoring of Forest Fires ISDM-Rosleskhoz, or in the information and computing system of JSC Russian Railways. In the Russian Federation, it is forbidden to use foreign systems in the security services of industrial facilities. The implementation of the deterministic model of heat transfer in the enclosing structure with the complexity of the algorithm O (2N2 + 2K) is presented. The program is implemented in Python 3.x using the NumPy and Concurrent libraries. Calculations were carried out on a multiprocessor cluster in the Sirius University of Science and Technology. The results of calculations and the acceleration coefficient for operating modes for 1, 2, 4, 8, 16, 32, 48 and 64 processes are presented. The developed algorithm can be applied to assess the fire safety of infrastructure facilities of Russian Railways. The main merit of the new development should be noted, which is explained by the ability to use large computational domains with a large number of computational grid nodes in space and time. The use of caching intermediate data in files made it possible to distribute a large number of computational nodes among the processors of a computing multiprocessor system. However, one should also note a drawback; namely, a decrease in the acceleration of computational operations with a large number of involved nodes of a multiprocessor computing system, which is explained by the write and read cycles in cache files.
The increased prevalence of pulmonary methicillin-resistant Staphylococcus aureus (MRSA) infection in patients living with cystic fibrosis (CF) is concerning due to a correlation with reduced life ...expectancy and lack of available treatment options. RV94 is a next generation lipoglycopeptide designed for pulmonary delivery that preclinically demonstrated high potency against MRSA in planktonic and protected colonies and improved pulmonary clearance relative to same class molecules. Here, RV94 was formulated into a dry powder for inhalation (DPI) to investigate the localized treatment of pulmonary MRSA presented in a potentially more convenient dosage form. RV94 DPI was generated using a spray-drying process with 12.5 wt% trileucine and demonstrated aerosol characteristics (2.0 μm MMAD and 73% FPF) predictive of efficient pulmonary deposition. In vivo PK from a single dose of RV94 DPI delivered by inhalation to rats yielded lung levels (127 μg/g) much greater than the MRSA minimum inhibitory concentration (0.063 μg/mL), low systemic levels (0.1 μg/mL), and a lung t1/2 equal to 3.5 days. In a rat acute pulmonary MRSA model, a single dose of RV94 DPI delivered by inhalation either up to seven days prior to or 24 h after infection resulted in a statistically significant reduction in lung MRSA titer.
Influence of the RF magnetic field on beam dynamics in SC200 cyclotron Karamysheva, G.; Popov, D.; Karamyshev, O. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
10/2019, Letnik:
940
Journal Article
Recenzirano
The SC200 superconducting cyclotron is developed by the collaboration between ASIPP (Hefei, China) and JINR (Dubna, Russia). The SC200 cyclotron will deliver 200 MeV beam for proton therapy and ...research.
The influence of the time-dependent magnetic field created by the acceleration system of SC200 should be taken into account in beam dynamics simulations and during the shimming procedure, as two conditions are present together: first — due to the spiral shape of the accelerating cavities, there is no vertical plane of symmetry through the middle of the dee; and second — second harmonic mode of acceleration in four-sector magnet structure imposes that the RF phase shift from beam entrance of the dee to its exit is not 180 degrees.
Particle tracking was performed with 3D maps of electromagnetic fields obtained from computer modelling of the magnet system and the accelerating RF cavities using CST Studio Suite. We have calculated particle dynamics taking into account RF magnetic field and have estimated a value of additional mean field needed for the compensation of beam phase lag induced by RF magnetic field. And finally, we designed a shim that should form the required additional field.
The article discusses the features of large-scale spatial and temporal variability of moistening (potential evapotranspiration, precipitation, potential evapotranspiration coefficient) in the ...Siberian part of Russia for the period 1981–2015. The All-Russian Research Institute of Hydrometeorological Information—World Data Center (RIHMI-WDC) archive has served as a source of initial information. Due to the rare network of stationary meteorological stations in most of Siberia, only 32 stations located mainly in the valleys of large rivers have been used for calculations. To estimate potential evapotranspiration, the modified method of M.I. Budyko has been used. A comprehensive delimitation of Siberia has been carried out by the interannual fluctuations of characteristics of moistening, being well divided into four regions, three of which encompass the basins of the largest rivers: the Ob, the Yenisei, the Lena and the fourth region represents the Baikal region. Analysis of the trends shows that the evapotranspiration in Siberia is growing only in the Ob basin and the Baikal region. Precipitation, excluding the Baikal region, is also increasing in the Yenisei and Lena basins. As for the potential evapotranspiration coefficient, a significant trend refers only to the Baikal region due to the rapid increase in evaporation. The modeling of the annual values of the characteristics of moistening for the selected regions has been carried out using the decision trees method. For 4-branch trees, the coefficient of determination R2 describes about two-thirds of the variance of the original variable (0.57–0.73). In the models of annual evapotranspiration values, the main predictor is the air temperature. In precipitation models, the contribution of local and external circulation factors to interannual precipitation fluctuations is equal.
Fucoidan from marine brown algae has been known to exert several health benefits, primarily antioxidant and anticancer properties. The primary goal of this research was to encapsulate fucoidan in ...stable water-in-oil-in-water (W1/O/W2) emulsions using an ultrasound technique. We optimized primary emulsion and double emulsion formulations using the response surface methodology (RSM). The formulation for primary emulsion and double emulsion is based on lecithin as the lipophilic surfactant concentration (0–5%), sonication time (20, 25, and 30 min), and hydrophilic surfactant Tween 80 (0–2.5%), respectively. Both emulsions are further characterized based on variables such as drop size, antioxidant activity, gravitational stability, peroxide value, and encapsulation efficiency. Based on RSM, the double emulsion with optimum conditions (sonication time, 25 min; internal emulsifier lecithin, 2.6%, sonication amplitude, 71%; and external emulsifier Tween 80, 1.2%) showed a small drop size (726 nm), antioxidant activity (91.33%), a stability of 85.33%, and an encapsulation efficiency of 90.36. Further optimized and stable double emulsions were assayed during 45 days of storage at a temperature of 37 °C. The results showed a slight change with minimal percentage loss of encapsulation efficiency from 90.36 to 86.78%.
We present a post-training weight pruning method for deep neural networks that achieves accuracy levels tolerable for the production setting and that is sufficiently fast to be run on commodity ...hardware such as desktop CPUs or edge devices. We propose a data-free extension of the approach for computer vision models based on automatically-generated synthetic fractal images. We obtain state-of-the-art results for data-free neural network pruning, with ~1.5% top@1 accuracy drop for a ResNet50 on ImageNet at 50% sparsity rate. When using real data, we are able to get a ResNet50 model on ImageNet with 65% sparsity rate in 8-bit precision in a post-training setting with a ~1% top@1 accuracy drop. We release the code as a part of the OpenVINO TM Post-Training Optimization tool 1 .
Treprostinil (TRE) is a prostanoid analog pulmonary vasodilator drug marketed with subcutaneous, intravenous (i.v.), oral, and inhaled routes of administration for the treatment of pulmonary arterial ...hypertension (PAH). Due to its short half-life, TRE requires either continuous infusion or multiple dosing, which exacerbates its side effects. Therefore, a long-acting prostanoid analog that maintains the positive attributes of TRE but has fewer TRE-related side effects could be of clinical benefit. In this report, we describe the discovery, preclinical development, and biology of the TRE ester prodrug, treprostinil palmitil (TP), which is formulated in a lipid nanoparticle (LNP) for administration as a nebulized inhaled suspension (TPIS). In screening assays focused on the conversion of prodrug to TRE, TP (16 carbon alkyl chain) had the slowest rate of conversion compared with short–alkyl chain TRE prodrugs (i.e., 2–8 carbon alkyl chain). Furthermore, TP is a pure prodrug and possesses no inherent binding to G-protein coupled receptors including prostanoid receptors. Pharmacokinetic studies in rats and dogs demonstrated that TPIS maintained relatively high concentrations of TP in the lungs yet had a low maximum plasma concentrations (Cmax) of both TP and, more importantly, the active product, TRE. Efficacy studies in rats and dogs demonstrated inhibition of pulmonary vasoconstriction induced by exposure to hypoxic air or i.v.-infused U46619 (thromboxane mimetic) over 24 h with TPIS. Cough was not observed with TPIS at an equivalent dose at which TRE caused cough in guinea pigs and dogs, and there was no evidence of desensitization to the inhibition of pulmonary vasoconstriction in rats with repeat inhaled dosing. TPIS was also more efficacious than i.v.-infused TRE in a sugen/hypoxia rat model of PAH to inhibit pulmonary vascular remodeling, an effect likely driven by local activities of TRE within the lungs. TPIS also demonstrated antifibrotic and anti-inflammatory activity in the lungs in rodent models of pulmonary fibrosis and asthma. In a phase 1 study in healthy human participants, TPIS (referred to as INS1009) had a lower plasma TRE Cmax and fewer respiratory-related side effects at equimolar doses compared with inhaled TRE. We have now formulated TP as an aerosol powder for delivery by a dry powder inhaler (referred to as treprostinil palmitil inhalation powder-TPIP), and as an aerosol solution in a fluorohydrocarbon solvent for delivery by a metered dose inhaler. These options may reduce drug administration time and involve less device maintenance compared with delivery by nebulization.
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