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2025
An ultrasound-responsive hydrogel system was developed that provides on-demand release when stimulated by focused ultrasound (fUS). Diels–Alder cycloadducts crosslinked polyethylene glycol (PEG) hydrogels and underwent a retrograde Diels–Alder reaction when exposed to fUS. Four-arm and eight-arm furan-based Diels–Alder hydrogel compositions were used to evaluate the link between the crosslinking density and the fUS-induced release and retention rates. PEG crosslinked with glutaraldehyde was also used as a non-Diels–Alder control hydrogel. By increasing the exposure time and the amplitude of fUS, the Diels–Alder-based hydrogels exhibited a correlative increase in the release of the entrapped BMP-2. Real-time B-mode imaging was used during fUS to visualize the on-demand degradation of the crosslinking matrix for the release of BMP-2. When monitored with a thermocouple, the increase in temperature observed was minimal in the area surrounding the sample during fUS stimulation, indicating fUS to be an external stimulus which could be used safely for spatiotemporally controlled release. PEG hydrogels were characterized using nuclear magnetic resonance, Fourier transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, and compression testing. PEG degradation byproducts were evaluated for cytocompatibility in vitro. Overall, this study demonstrated that Diels–Alder-based PEG hydrogels can encapsulate BMP-2, undergo a retrograde reaction when externally stimulated with fUS, and release active BMP-2 to induce differentiation in human mesenchymal stem cells.- Book : 11(2)
- Pub. Date : 2025
- Page : pp.120-120
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2025
New higher-count-rate, integrating, large-area X-ray detectors with framing rates as high as 17400 images per second are beginning to be available. These will soon be used for specialized macromolecular crystallography experiments but will require optimal lossy compression algorithms to enable systems to keep up with data throughput. Some information may be lost. Can we minimize this loss with acceptable impact on structural information? To explore this question, we have considered several approaches: summing short sequences of images, binning to create the effect of larger pixels, use of JPEG-2000 lossy wavelet-based compression, and use of Hcompress, which is a Haar-wavelet-based lossy compression borrowed from astronomy. We also explore the effect of the combination of summing, binning, and Hcompress or JPEG-2000. In each of these last two methods one can specify approximately how much one wants the result to be compressed from the starting file size. These provide particularly effective lossy compressions that retain essential information for structure solution from Bragg reflections.- Book : 32(2)
- Pub. Date : 2025
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2025
Abstract
Plasma fluence at the divertor of a future magnetic confinement fusion device can accumulate up to ~1028-1029 m-2 per year. Yet hydrogen isotope retention under such high-fluence plasma exposure has been rarely reported. To investigate deuterium (D) retention in tungsten (W) exposed to such high-fluence plasma, a series of high-flux D plasma exposures were preformed using recrystallized W samples at ~500 K in Magnum-PSI. The highest fluence achieved was ~1×1029 m-2. Surface morphology observations indicate an initial increase in the number of blisters at the sample surface with increasing fluence, followed by saturation at ~1×1029 m-2. Multiple bursts of blisters with open cracks or edges were observed under the two highest fluences of ~1×1028 m-2 and ~1×1029 m-2. 3He nuclear reaction analysis (NRA) shows a maximum D concentration up to 0.012 at.fr., distributed within the first 4 μm from the sample surface under the highest fluence. D retention, as measured by NRA and thermal desorption spectroscopy, tends to saturate with increasing fluence. Simulations of D2 thermal desorption, performed using the TMAP rate equation code, show a maximum D trapping depth of ~10 µm, consistent with the defect depth profile revealed by transmission electron microscopy. D retention saturation observed in this work is attributed to the sample surface morphology modifications and the saturation of plasma-induced defects. This investigation provides a valuable reference for understanding the evolution of total hydrogen isotope retention in W under high-fluence plasma exposure in future fusion devices.- Book : ()
- Pub. Date : 2025
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2025
Abstract
Transient heat flux up to thousands of MW/m2 in a short pulse (~ms) in tokamak poses great challenge on plasma facing components (PFCs), a major concern for ITER. Despite numerous high heat flux tests, the analysis of in situ transient heat flux-induced damage on PFCs remains necessary. Such damages, including the melting and cracking of tungsten (W) PFCs, are notably observed on the divertor (dome and baffle plates) and limiter in EAST. These damages are identified as being induced by runaway electron loss during plasma disruption in the early startup phase of each plasma campaign. They typically occur at the leading edges or protruding parts of PFCs, sometimes accompanied by visible macrocracks. Regarding melting phenomena, three distinct grain layers are observed from the molten surface to the deeper regions: columnar grain, equiaxed grain (recrystallization region) and original grain. This grain distribution indicates a steep temperature gradient from the surface to the deeper regions during melting events, a characteristic feature for W under fusion-relevant transient heat flux loading from electron/ion beam tests. The surface morphologies of all melted PFCs are generally similar, characterized by undulated melting waves. The movement of the melting layer is primarily along the toroidal direction, as shown in the in-situ melting PFCs. The influence of the J×B force might not be significant due to the limited life of the melting pool, which results in limited acceleration time and expected bulk melt displacements, even if the J×B force is the dominant force. The directions of plasma pressure and Marangoni flow, both along the toroidal direction, might be the dominant forces here. Additionally, cracks at leading edges were observed on the divertor dome and baffle plates during post-mortem inspection. In some cases, dense cracks were visible in the melting region and even in areas far from the melting zone. It should be noted that cracks were only found on partially melted PFCs, which could be related to the base temperature when PFCs were hit by the runaway electron-induced transient heat flux. Furthermore, some columnar grains were observed to exfoliate from the material, indicating severe cracking. Since EAST has similar W PFCs to ITER, the transient heat flux-induced melting and cracking damages on W PFCs by runaway electrons during plasma disruption in EAST provide important references for ITER.- 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
Kefir, a traditional probiotic beverage with significant cultural, social, and health relevance, has garnered increasing scientific interest for its functional properties. Here, we synthesized findings from 14 studies investigating the bacterial and fungal diversity in artisanal cow’s milk kefir through metagenomic analysis. Following the PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-Analyses), a comprehensive search was conducted in databases including Portal BVS, Scopus, Scielo, and Web of Science. From an initial pool of 522 articles, 14 were selected based on stringent inclusion and exclusion criteria, focusing on English-written studies. Key terms such as “kefir milk”, “artisanal kefir”, “milk”, “metagenomics”, and “cow” were identified through Boolean searches over the last five years. This review addresses the growing need for research on the microbial diversity of artisanal cow’s milk kefir from various global regions. The results indicate a remarkable diversity in microbial communities, primarily dominated by bacteria from the phylum Firmicutes (notably Lactobacillus) and yeasts from the genera Saccharomyces and Kluyveromyces. These microbial compositions are shaped by factors such as milk type, production methods, and grain handling practices, reflecting regional adaptations and influencing kefir’s sensory, probiotic, and functional properties. We argue that a full understanding of these microbial dynamics is critical for standardizing production processes and enhancing quality control measures, ultimately ensuring artisanal kefir’s consistency and health benefits.- Book : 11(3)
- Pub. Date : 2025
- Page : pp.150-150
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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
- Book : 3()
- Pub. Date : 2025
- Page : pp.102330-102330
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2025
Nuclear medium effects on B+ meson production are studied using the binary-collision scaled cross section ratio between events of different charged-particle multiplicities from proton-lead collisions. Data, collected by the CMS experiment in 2016 at a nucleon-nucleon center-of-mass energy of sNN=8.16 TeV, corresponding to an integrated luminosity of 175 nb−1, were used. The scaling factors in the ratio are determined using a novel approach based on the Z→μ−μ+ cross sections measured in the same events. The scaled ratio for B+ is consistent with unity for all event multiplicities, putting stringent constraints on nuclear modification for heavy flavor.
© 2025 CERN, for the CMS Collaboration
2025
CERN
- Book : 134(11)
- Pub. Date : 2025
- Page :
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