By designing a structured gas density profile between the dual-stage gas jets to manipulate electron seeding and energy chirp reversal for compressing the energy spread, we have experimentally ...produced high-brightness high-energy electron beams from a cascaded laser wakefield accelerator with peak energies in the range of 200-600 MeV, 0.4%-1.2% rms energy spread, 10-80 pC charge, and ∼0.2 mrad rms divergence. The maximum six-dimensional brightness B_{6D,n} is estimated as ∼6.5×10^{15} A/m^{2}/0.1%, which is very close to the typical brightness of e beams from state-of-the-art linac drivers. These high-brightness high-energy e beams may lead to the realization of compact monoenergetic gamma-ray and intense coherent x-ray radiation sources.
Transport coefficients of correlated electron systems are often useful for mapping hidden phases with distinct symmetries. Here we report a transport signature of spontaneous symmetry breaking in the ...magnetic Weyl semimetal cerium-aluminum-germanium (CeAlGe) system in the form of singular angular magnetoresistance (SAMR). This angular response exceeding 1000% per radian is confined along the high-symmetry axes with a full width at half maximum reaching less than 1° and is tunable via isoelectronic partial substitution of silicon for germanium. The SAMR phenomena is explained theoretically as a consequence of controllable high-resistance domain walls, arising from the breaking of magnetic point group symmetry strongly coupled to a nearly nodal electronic structure. This study indicates ingredients for engineering magnetic materials with high angular sensitivity by lattice and site symmetries.
China's seas cover nearly 5 million square kilometers extending from the tropical to the temperate climate zones and bordering on 32,000 km of coastline, including islands. Comprehensive systematic ...study of the marine biodiversity within this region began in the early 1950s with the establishment of the Qingdao Marine Biological Laboratory of the Chinese Academy of Sciences. Since that time scientists have carried out intensive multidisciplinary research on marine life in the China seas and have recorded 22,629 species belonging to 46 phyla. The marine flora and fauna of the China seas are characterized by high biodiversity, including tropical and subtropical elements of the Indo-West Pacific warm-water fauna in the South and East China seas, and temperate elements of North Pacific temperate fauna mainly in the Yellow Sea. The southern South China Sea fauna is characterized by typical tropical elements paralleled with the Philippine-New Guinea-Indonesia Coral triangle typical tropical faunal center. This paper summarizes advances in studies of marine biodiversity in China's seas and discusses current research mainly on characteristics and changes in marine biodiversity, including the monitoring, assessment, and conservation of endangered species and particularly the strengthening of effective management. Studies of (1) a tidal flat in a semi-enclosed embayment, (2) the impact of global climate change on a cold-water ecosystem, (3) coral reefs of Hainan Island and Xisha-Nansha atolls, (4) mangrove forests of the South China Sea, (5) a threatened seagrass field, and (6) an example of stock enhancement practices of the Chinese shrimp fishery are briefly introduced. Besides the overexploitation of living resources (more than 12.4 million tons yielded in 2007), the major threat to the biodiversity of the China seas is environmental deterioration (pollution, coastal construction), particularly in the brackish waters of estuarine environments, which are characterized by high productivity and represent spawning and nursery areas for several economically important species. In the long term, climate change is also a major threat. Finally, challenges in marine biodiversity studies are briefly discussed along with suggestions to strengthen the field. Since 2004, China has participated in the Census of Marine Life, through which advances in the study of zooplankton and zoobenthos biodiversity were finally summarized.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This paper reviews recent developments in research in nanostructured permanent magnets (hard magnetic materials) with emphasis on bottom-up approaches to fabrication of hard/soft nanocomposite bulk ...magnets. Theoretical and experimental findings on the effects of soft phase and interface conditions on interphase exchange interactions are given. Synthesis techniques for hard magnetic nanoparticles, including chemical solution methods, surfactant-assisted ball milling and other physical deposition methods are reviewed. Processing and magnetic properties of warm compacted and plastically deformed bulk magnets with nanocrystalline morphology are discussed. Prospects of producing bulk anisotropic hard/soft nanocomposite magnets are presented.
Background
The expression of chronic rhinosinusitis (CRS) is multidimensional. Disease heterogeneity in patients with CRS remains poorly understood. This study aimed to identify endotypes of CRS ...using cluster analysis by integrating multidimensional characteristics and to explore their association with treatment outcomes.
Methods
A total of 28 clinical variables and 39 mucosal cellular and molecular variables were analyzed using principal component analysis. Cluster analysis was performed on 246 prospectively recruited Chinese CRS patients with at least 1‐year postoperative follow‐up. Difficult‐to‐treat CRS was characterized in each generated cluster.
Results
Seven subject clusters were identified. Cluster 1 (13.01%) was comparable to the classic well‐defined eosinophilic CRS with polyps, having severe disease and the highest proportion of difficult‐to‐treat CRS. Patients in cluster 2 (16.26%) and cluster 4 (13.82%) had relatively lower proportions of presence of polyps and presented mild inflammation with moderate proportions of difficult‐to‐treat cases. Subjects in cluster 2 were highly atopic. Cluster 3 (7.31%) and cluster 6 (21.14%) were characterized by severe or moderate neutrophilic inflammation, respectively, and with elevated levels of IL‐8 and high proportions of difficult‐to‐treat CRS. Cluster 5 (4.07%) was a unique group characterized by the highest levels of IL‐10 and lacked difficult‐to‐treat cases. Cluster 7 (24.39%) demonstrated the lowest symptom severity, a low proportion of difficult‐to‐treat CRS, and low inflammation load. Finally, we found that difficult‐to‐treat CRS was associated with distinct clinical features and biomarkers in the different clusters.
Conclusions
Distinct clinicopathobiologic clusters of CRS display differences in clinical response to treatments and characteristics of difficult‐to‐treat CRS.
The stacking fault energy (SFE) values of several typical face-centered-cubic (fcc) high-entropy alloys (HEAs) were experimentally measured by weak-beam dark-field transmission electron microscopy. ...It was found that the SFE of the Fe-Co-Ni-Cr-Mn HEA system strongly depends on the SFE of the individual constituents. Specifically, the SFE of this HEA system is closely associated with the Ni concentration in the alloys. Additionally, the lower SFE tends to promote formation of more deformation twins with a smaller thickness under loading, leading to better mechanical properties, especially at low temperatures.
•SFE of six Fe-Co-Ni-Cr-Mn HEAs was measured experimentally.•Constituents play an important role in the SFE, particularly the Ni content.•Lower SFE promotes formation of thinner twins during loading and better properties.
Summary
Background
TCS (topical corticosteroids) are the first‐line drug in the treatment of oral lichen planus (OLP). However, the value of topical calcineurin inhibitors (TCI) including tacrolimus, ...pimecrolimus and ciclosporin for OLP is still controversial.
Objectives
To compare the efficacy and safety of TCI vs. TCS for OLP.
Methods
The authors searched PubMed, Embase, Cochrane Central Register of Controlled Trials, Web of Science and four Chinese databases from 1950 to May 2018. The randomized controlled trials comparing TCI and TCS for OLP reported at least one of the following outcomes: improvement of clinical signs and/or symptoms, relapse, blood levels of TCI and adverse events.
Results
Twenty‐one trials involving 965 patients were included in the analysis. For the treatment of OLP (3–8 weeks), TCI including tacrolimus, pimecrolimus and ciclosporin were similar to TCS in efficacy. Tacrolimus–TCS resulted in similar outcomes, with relapse at 3 weeks to 6 months. Blood levels of TCI were usually undetectable. In addition, tacrolimus showed a statistically higher incidence of local adverse events than TCS for short‐term treatment. A few systemic adverse events occurred in the tacrolimus and ciclosporin groups, but they were not serious.
Conclusions
The evidence for tacrolimus (n = 12), pimecrolimus (n = 3) and ciclosporin (n = 6) demonstrated that treatment with TCI may be an alternative approach when OLP does not respond to the standard protocols. Tacrolimus 0·1% should be the first drug of choice when selecting TCI for short‐term treatment in recalcitrant OLP. Further well‐designed trials are warranted to evaluate the long‐term efficacy and safety of TCI.
What's already known about this topic?
The main topical drug for oral lichen planus (OLP) is topical corticosteroids (TCS).
Patients with OLP who are not responsive to TCS or are at risk of adverse events from TCS need other alternative drugs.
Topical calcineurin inhibitors (TCI), including tacrolimus, pimecrolimus and ciclosporin, have become a hot topic in a variety of mucocutaneous immune‐mediated diseases.
What does this study add?
TCI including tacrolimus, pimecrolimus and ciclosporin were similar to TCS in efficacy for the short‐term treatment of OLP.
The local adverse events of tacrolimus were higher than with TCS. A few systemic adverse events were reported with TCI, but they were all tolerable and not serious.
The limited evidence for pimecrolimus (three trials) and ciclosporin (six trials) requires further studies to evaluate the short‐term and long‐term efficacy and safety of TCI compared with TCS.
Linked Comment: Thongprasom. Br J Dermatol 2019; 181:1120.
Plain language summary available online
The South Atlantic Anomaly (SAA) refers to a region where the strength of the magnetic field is notably weaker compared to a dipole field. While previous studies have primarily focused on its effects ...on the inner radiation belt, this study investigates its impact on the aurora system. By analyzing 2 years' worth of data obtained by the Fengyun‐3E/ACMag instrument, we discover that magnetic fluctuations within the auroral oval are significantly weaker in the longitude sector corresponding to the SAA, as compared to those outside this area. This characteristic remains permanent and independent of seasons and geomagnetic activities. Additional investigation using Defense Meteorological Satellite Program/Special Sensor Ultraviolet Spectrographic Imager (DMSP/SSUSI) observations reveals a similar phenomenon in the auroral intensity. Therefore, our results demonstrate that the SAA substantially weakens the aurora system, shedding new light on the effects of magnetic anomalies on planetary auroras and magnetosphere‐ionosphere‐thermosphere coupling.
Plain Language Summary
The South Atlantic Anomaly (SAA) is a unique location on Earth where the magnetic field is weaker than normal. This region has drawn a lot of attention because its weakened magnetic field brings the inner Van Allen radiation belt unusually close to the Earth's surface, which poses a threat to satellites passing through it. Here, we uncovered another interesting aspect of the SAA: its impact on the aurora system. To investigate this, we first examined 2 years' worth of data from the ACMag instruments on the Fengyun‐3E satellite, which orbits the Earth at an altitude of 836 km in a dawn‐dusk, Sun‐synchronous orbit. Our findings reveal that the magnetic fluctuations within the southern auroral oval are significantly weaker in the region that aligns with the SAA. This weakening effect is consistently present, regardless of the season or the level of geomagnetic activity. To reinforce our results, we also analyzed auroral intensity from the Special Sensor Ultraviolet Spectrographic Imager (SSUSI) instrument on the Defense Meteorological Satellite Program (DMSP) satellite, and it corroborated the same weakening trend in this data set. In conclusion, our observations demonstrate that the SAA has a substantial impact on weakening the aurora system. This discovery deepens our understanding of how magnetic anomalies can influence planetary auroras.
Key Points
The effects of the South Atlantic Anomaly (SAA) on the terrestrial aurora system are examined using multiple instruments
Observations reveal a substantial weakening of auroral magnetic fluctuations and auroral intensity in the SAA longitude sector
The results indicate considering magnetic anomalies like the SAA is essential for comprehensively understanding planetary aurora systems
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