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2025
RELEVANCE. The Arctic zone is becoming a subject of increasing interest due to climate change and the growing need for sustainable development. The introduction of renewable energy sources is becoming key to the sustainability and security of the region. The research aimed at solving the problems of development of the Arctic zone of Russia with a focus on overcoming transportation and energy constraints and introducing renewable energy sources is highly relevant.THE PURPOSE. The study aims to develop and implement sustainable and efficient energy systems in the Arctic zone of Russia using renewable energy sources, with a focus on solar energy. To develop a simulation model of a solar array with a positioning system and demonstrate an approach to improve the efficiency of solar power plants, which is important for current technological research in renewable energy.METHODS. Collection and analysis of measured data of solar radiation values and sunshine duration in different areas of Murmansk region. To evaluate the efficiency of solar panels application, a simulation model was developed in the program complex Matlab application Simulink.RESULTS. The results of the study allowed to identify the potential of solar energy utilization in different areas of the Murmansk region. The performed calculations allowed to determine the optimal capacity of solar panels for the Khibiny mountain range, which contributes to the effective utilization of solar energy. A simulation model of a solar panel with the implementation of a battery positioning system to improve the efficiency of operation is presented.CONCLUSION. The significant potential of solar energy utilization in the Arctic zone is achieved with the help of a positioning system, which holds promise for sustainable development of the region and improved energy efficiency. Adaptation of solar power plants to specific climatic conditions optimizes their performance and ensures sustainability even in the harsh climate of northern regions- Book : 27(1)
- Pub. Date : 2025
- Page : pp.48-58
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2025
The irradiation by gamma-rays is a widely used technique for disinfection in the pharmaceutical and cosmetic industries. In view of growing concerns by consumers about this technique, further investigation of the effects of radiation is required. In this work electron paramagnetic resonance (EPR) spectroscopy was applied to study the free radicals in irradiated horse chestnut (Aesculus hippocastanum L.) seeds and to evaluate the free radical scavenging activity (FRSA) using the stable DPPH radical. In order to evaluate the antiradical potential, a spectrophotometric study was also used. The identification and quantification of some individual polyphenol compounds before and after irradiation by 1, 5, and 10 kGy gamma rays of peeled and shell seeds were obtained by high performance liquid chromatography (HPLC). The EPR spectrum recorded on irradiated horse chestnut is a typical signal for irradiated cellulose-contained substances. The results show that the signal is stable, and it can be found in the samples irradiated with a dose of 1 kGy, 45 days after treatment, whereas for samples irradiated by 5 and 10 kGy, it is even found 250 days later. The study showed that free radical scavenging activity increases in shell seeds, while it decreases in peeled seed extracts after irradiation depending on the dosage, which corresponds to the total phenolic content. Shell seed extracts have significantly stronger antiradical activity than that of peeled seeds. Regarding the HPLC analysis, some polyphenolics were degraded and others were formed as a result of irradiation. The irradiation by 5 kGy dosage has a most significant positive effect on the antioxidant potential of shell chestnut seeds.- Book : 15(6)
- Pub. Date : 2025
- Page : pp.3287-3287
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2025
Background. There is a lack of data on the incidence of aspirin nonresponsiveness and the efficacy of different forms of ASA in patients with diabetes.Aim. To evaluate the efficacy of buffered versus enteric-coated ASA based on the frequency of high residual platelet reactivity (HRPR) as measured by the VerifyNow Aspirin Test in patients with chronic coronary syndrome (CCS) and type 2 diabetes (T2D).Material and methods. The single-center observational parallel-group comparative study (CASCADE) included patients over 18 years of age with CCS and T2D who were prescribed a buffered form of ASA (Cardiomagnyl 75 mg/day) or an entericcoated form of ASA (Thrombo ACC® 100 mg/day or Aspirin® Cardio 100 mg/day) in routine practice prior to inclusion in the study and were randomly selected from the general consultative and diagnostic department of the hospital. According to the routine prescribed therapy, patients were divided into 2 following groups: patients taking Cardiomagnyl 75 mg/day; patients taking Thrombo ACC® 100 mg/day or Aspirin® Cardio 100 mg/day. At the first visit patients signed informed consent and received a card to assess the compliance of ASA intake, while at the second visit (after 7 days with 100% compliance) patients underwent laboratory assessment of ASA efficacy by VerifyNow Aspirin Test and light transmission aggregometry according to a special protocol including arachidonic acid induction. And the third visit included a call to the patient after 90 days, according to which information was collected about all events that occurred with the patient since the signing of the informed consent. The primary endpoint of the study was the incidence of HRPR on the background of ASA administration according to the VerifyNow Aspirin Test. The primary endpoint, tolerability and safety were evaluated in all patients included in the study. This study was registered at ClinicalTrials.gov, NCT06716255, and is currently completed.Results. Between February 28, 2024, and May 17, 2024, 200 patients were screened and 84 were successfully enrolled in the study, of which 42 patients received the enteric-coated ASA (Thrombo ACC® 100 mg/day, n=21; Aspirin® Cardio 100 mg/day, n=21) and 42 patients received the buffered ASA absorbed in the stomach (Cardiomagnyl 75 mg/day). The mean age of the study subjects was 68,9 years (standard deviation ±10,2); 34 (40,5%) patients were female and 50 (59,5%) were male. The study was terminated early because of larger than expected intergroup differences. At the time of the interim analysis (May 17, 2024), the incidence of HRPR according to the VerifyNow Aspirin Test was higher in the group of patients receiving the enteric-coated ASA (10 (23,8%) vs 3 (7,1%), p=0,035). By day 90, the incidence of composite endpoint (all-cause mortality; hospitalization for any cause; any ischemic (thrombotic) events) in the buffer ASA group was 7,1% (n=3), which was lower than in the enteric-coated ASA group, which was 16,7% (n=7), mainly due to hospitalisations. However, there were significant associations (p=0,178). One ischemic event was recorded in the enteric-coated ASA group, and there were no ischemic events in the buffered ASA group (p=0,314). There were no fatal outcomes in both groups during the follow-up period. At the same time, the rate of haemorrhagic events in patients with CCS and T2D while taking buffered and enteric-coated ASA was 3 (7,1%) and 4 (9,5%), respectively (p=0,693).Conclusion. Administration of a buffered form of ASA absorbed in the stomach in a group of patients with T2D could potentially allow for a reduction in the number of ASA nonresponsiveness, which could further lead to a reduction in the number of significant clinical events without loss of safety.- Book : 30(2)
- Pub. Date : 2025
- Page : pp.5282-5282
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2025
Green energy supply can be achieved by integrating intermittent renewable energy resources into the electrical distribution network. The intermittent nature of solar power generation presents significant technical challenges for integration that affect the network reliability and stability in relation to the grid power quality and voltage profile. Maximum utilization of photovoltaic in the electrical distribution network requires siting and sizing optimization. Distribution and transmission lines incur voltage drops and power losses due to their reactive and resistive properties. Application of evolutionary optimization techniques is adopted for optimal photovoltaic distributed generations placement in an electrical distribution network. Improved network voltage profile and system reliability was achieved by the application of particle swarm optimization algorithm to minimize the system’s power losses in a radial distribution network-IEEE 33-bus system. This was achieved through a MATLAB code implementation, with validation of the solution techniques and the developed model realized through a genetic algorithm case study. The active and reactive total loads linked to the network test system were 3.720 MW and 2.310 MVAr, accordingly. The conversion of solar power was modeled at a constant power factor with cut-off solar radiation ≥ 4.0 kWh/m2/day under normal operating conditions. As an initial configuration, active and reactive power losses were found as 211.02 kW and 143.04 kVAr without photovoltaic distributed generation at 0.85 pf, respectively. Integration of solar distributed generations at optimal location and capacity resulted in reduction of the network power losses by 57.98% reactive and 61.60% active. Improvement in voltage profile attained was 8.46%, while the ASAI network reliability index value before integrating solar source was 0.99734 p.u. but improved by 1.82% on installation. In conclusion, the system’s power losses reduced as acceptable voltage profile was maintained for sustained distribution network reliability.- Book : 9(1)
- Pub. Date : 2025
- Page : pp.105-120
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2025
Abstract. The direct interactions of atmospheric aerosols with radiation significantly impact the Earth's climate and weather and are important to represent accurately in simulations of the atmosphere. This work introduces two contributions to enable a more accurate representation of aerosol optics in atmosphere models: (1) NeuralMie, a neural network Mie scattering emulator that can directly compute the bulk optical properties of a diverse range of aerosol populations and is appropriate for use in atmosphere simulations where aerosol optical properties are parameterized, and (2) TAMie, a fast Python-based Mie scattering code based on the Toon and Ackerman (1981) Mie scattering algorithm that can represent both homogeneous and coated particles. TAMie achieves speed and accuracy comparable to established Fortran Mie codes and is used to produce training data for NeuralMie. NeuralMie is highly flexible and can be used for a wide range of particle types, wavelengths, and mixing assumptions. It can represent core-shell scattering and, by directly estimating bulk optical properties, is more efficient than existing Mie code and Mie code emulators while incurring negligible error compared to existing aerosol optics parameterization schemes (0.08 % mean absolute percentage error).
- Book : 18(5)
- Pub. Date : 2025
- Page : pp.1809-1827
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2025
AbstractPurposeUltra‐low field MRI scanners have the potential to improve health care delivery, both through improved access in areas where there are few MRI scanners and allowing more frequent monitoring of disease progression and treatment response. This may be particularly true in white matter disorders, including leukodystrophies and multiple sclerosis, in which frequent myelin‐sensitive imaging, such as magnetization transfer (MT) imaging, might improve clinical care and patient outcomes.MethodsWe implemented an on‐resonance approach to MT imaging on a commercial point‐of‐care 64 mT scanner using a non‐balanced steady‐state free precession sequence. Phantom and in vivo experiments were used to evaluate and optimize the sequence sensitivity and reproducibility, and to demonstrate in vivo performance and inter‐site reproducibility.ResultsFrom phantom experiments, T1 and T2 effects were determined to have a negligible effect on the differential MT weighting. MT ratio (MTR) values in white matter were 23.1 ± 1.0% from 10 healthy volunteers, with an average reproducibility coefficient of variation of 1.04%. Normal‐appearing white matter MTR values in a multiple sclerosis participant (21.5 ± 6.2%) were lower, but with a similar spread of values, compared to an age‐matched healthy volunteer (23.3 ± 6.2%).ConclusionAn on‐resonance MT imaging approach was developed at 64 mT that can be performed in as little as 4 min. A semi‐quantitative myelin‐sensitive imaging biomarker at this field strength is available for assessing both myelination and demyelination.- Book : ()
- Pub. Date : 2025
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2025
AbstractSince its discovery in 1997, the single molecule surface‐enhanced Raman spectroscopy (SM‐SERS) has attracted wide interest owing to its enormous potential in many fields. However, the commercialized applications of SM‐SERS are still limited by the lack of a clear understanding of the relevant mechanism in the famous SM‐SERS experiments. In this study, a salt‐gradient model is proposed to deeply investigate the physical nature and update insights into the morphological, structural, and component evolution processes of Ag NPs from dispersed nanostructures to aggregation states in the salt‐induced aggregation SERS strategy. A gradient interface is observed, where an ultrahigh sensitivity approaching a single molecule level, has been achieved in Ag colloidal system. An unusual dissolution of Ag, the release of Ag+ ions from Ag NPs, and the final precipitation of AgCl can be evidenced. Thus, except for aggregation effect, the active AgCl packaging shell on the surface of Ag NPs remarkably improves the SERS property. This work not only reveals the physics processes and nature of SM‐SERS but also offers a new way to exploit the SM‐SERS into practical applications by means of designing different surface states of NPs and various activation compositions to meet diverse molecule systems.- Book : ()
- Pub. Date : 2025
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2025
Abstract
Hyperfine interactions within Fe81B12Sn7 and (Fe0.75Co0.25)81B12Sn7 metallic glasses were explored through Mössbauer spectrometry using both 57Fe and 119Sn resonant nuclei. As-quenched specimens were fabricated via planar flow casting, followed by annealing at 673 K for 30 min, coinciding with the first stage of crystallization. After annealing, presence of crystalline components was revealed in the 57Fe Mössbauer spectra. They were identified in the respective samples as bcc-Fe and bcc-FeCo phases with small inclusions of Sn. However, no traces of crystalline components were directly seen in the 119Sn spectra. Partial replacing of Fe with Co resulted in an increase of the hyperfine magnetic fields at both iron and tin probe atoms.- Book : ()
- Pub. Date : 2025
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2025
Abstract
Characterizing quantum states of the electromagnetic field at microwave frequencies requires fast and sensitive detectors that can simultaneously probe the field’s time-dependent amplitude and its quantum fluctuations. So far, this has been achieved by using either homodyne detection or fast digitizers. Both methods rely on the extraction of microwave radiation through an amplification chain towards the detector placed at room temperature, thereby limiting the time resolution to the ~10-GHz bandwidth of the measurement chain. Additionally, the coupling of high-impedance samples to the 50-Ω measurement chain is very weak, setting strong limitations on the detection sensitivity. In this work, we demonstrate an on-chip quantum sensor that exploits the phase of a single-electron wavefunction, measured in an electronic Fabry–Pérot interferometer, to detect the amplitude of a classical time-dependent electric field. The interferometer is implemented in a GaAs/AlGaAs quantum Hall conductor. The time resolution, limited by the temporal width of the electronic wavepacket, is ~35 ps. The interferometry technique provides a voltage resolution of ~50 μV, corresponding to a few microwave photons. Importantly, our detector measures both phase and contrast of the interference pattern. The latter opens the way to the detection of non-classical electromagnetic fields, such as squeezed or Fock states.- Book : ()
- Pub. Date : 2025
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2025
Introduction: Diethyl nitrosamine (DEN), a known carcinogen, has been used for validating the RasH2 and P53 transgenic models in chemical testing and has been shown to enhance primary liver tumor growth in the ATT-Myc transgenic mouse model of liver cancer. Material and Methods: to better understand the mechanism of hepatocellular carcinoma acceleration following DEN, BHT and vehicles treatments in ATT-Myc, transgenic and non-transgenic, mice. We employed an exon array, RT-PCR, Western blotting, and IHC to investigate the complex interplay between the c-Myc transgene and other growth factors in treated mice versus control transgenic and non-transgenic mice. Results: Notably, DEN treatment induced a 12-fold increase in c-Myc expression compared to non-transgenic mice. Furthermore, tumor growth in the DEN group was strongly associated with increased proliferation of transformed or carcinogenic hepatocytes, as evidenced by proliferative cell nuclear antigen and bromodeoxyuridine expression. Internally, the loss of c-Met signaling, enriched transcription factors, and the diminished expression of antioxidants, such as superoxide dismutase (SOD1) and NRF2, further enhanced c-Myc-induced liver tumor growth as early as four months post-DEN treatment. Discussion: Extensive tumor growth was observed at 8.5 months, coinciding with the downregulation of tumor suppressors such as p53. In contrast, at these time points, ATT-Myc transgenic mice exhibited only dysplastic hepatocytes without tumor formation. Additionally, the antioxidant butylated hydroxytoluene maintained c-Met expression and did not promote liver tumor formation. Conclusions: the persistent upregulation of c-Myc in the ATT-Myc liver cancer model, at both the gene and protein levels following DEN treatment inhibited the ETS1 transcription factor, further exacerbating the decline of c-Met signaling, SOD1, and NRF2. These changes led to increased reactive oxygen species production and promoted rapid liver tumor growth.- Book : 13(3)
- Pub. Date : 2025
- Page : pp.743-743
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