Two-stroke spark ignition engines are widely used in Unmanned Aerial Vehicles. Aviation kerosene offers advantages over aviation gasoline due to its higher flash point and lower volatility, making it likely to be adopted more widely in the future. However, the poor evaporation and atomization characteristics of aviation kerosene result in suboptimal ignition performance, especially in the engine start-up phase. To explore the fitting mixture concentration and temperature conditions for achieving better ignition performance of aviation kerosene, A series of experimental studies are conducted on a two-stroke engine. The intrinsic factors affecting engine performance are analyzed. The experimental results indicate that optimal ignition characteristics, maximum power output, and a reduced misfire rate can be achieved at mixture concentration of 0.6 and mixture temperature of 80?C. Furthermore, the misfire rate is most sensitive to the combustion duration, while the cyclic variations show significant sensitivity to ignition delay. The results provide guidance for optimizing ignition performance during the start-up phase of two-stroke engines fueled with aviation kerosene.

• Book : (00)
• Pub. Date : 2025
• Page : pp.18-18
• Keyword :

Abstract The combination of plastic scintillators with Silicon Photo-Multipliers (SiPMs) is widely used for detecting radiation in high-energy astrophysics, particle physics, neutrino physics, or medical physics. An example of application for this kind of detectors are Compton polarimeters such as POLAR-2 [1,2,3] or LEAP [4,5,6] for which a low-Z material is needed for the Compton effect to be dominant down to as low energy as possible. Such detectors aim to measure low energy Compton depositions in organic scintillators which produce small amounts of optical light because of the low energy deposited and the low scintillation efficiency, and for which optimizing the instrumental optical properties consequently imperative. The light collection efficiency of such a device was studied with a focus on the POLAR-2 Gamma-Ray Burst polarimeter. POLAR-2 consists of a segmented array of 6400 elongated plastic scintillators divided into 100 modules, all read out by SiPMs. The conversion of incoming γ-rays into readable signal goes through the production and collection of optical light, which has been optimized both through measurements and simulations. The optical elements of the POLAR-2 polarimeter prototype module were optically characterized and an optical simulation based on Geant4 was developed to fully model its optical performances. The results from simulations were used to optimize the design and finally to verify its performance. The study resulted in a detector capable of measuring energy depositions of several keV. In addition, an important finding of this work is the impact of the plastic scintillator surface roughness on the light collection. It was found that a plastic scintillator with a higher scintillation efficiency but made of a softer material, hence with a rougher surface, was not necessarily the best option to optimize the light collection. Furthermore, in order to optimize the optical crosstalk between different channels, a production technique for very thin (∼150 μm) and reusable silicone-based optical coupling pads was developed. This method can be adapted to produce either standalone pads or to directly mold a layer on any SiPM to be later coupled to the scintillators. After an introductory discussion describing the need of a large scale GRB polarimeter like POLAR-2, the optical design and characterization of the polarimeter modules that compose its sensitive part are described. The Geant4-based optical simulations of the POLAR-2 modules and the impact of the optical properties of its various elements on the light collection efficiency of the instrument are later presented. The work is finally summarized and an outlook is given on the potential applications of the POLAR-2 optical characterization and simulation work to other experiments employing similar elements.

• Book : 20(02)
• Pub. Date : 2025
• Page : pp.P02010-P02010
• Keyword :

Dongshan Bay is a typical subtropical semi-enclosed bay characterized by abundant fish resources. We aimed to assess fish diversity and its seasonal variation in Dongshan Bay and to provide a scientific basis for the sustainable management and conservation of the fishery’s resources. In this study, we employed environmental DNA (eDNA) metabarcoding technology to analyze fish diversity in the bay during winter 2023 and summer 2024. A total of 76 fish species were detected across 12 sampling sites, with 43 species identified in summer and 45 species seen in winter. Overall, 13 species were detected in both the winter and summer. Non-significant differences were observed in Alpha diversity among the sampling sites. Fish species richness at the HXH2 site was the lowest among all the sampling sites for the reason that this sampling site was near to the effluent outlet of the Zhangzhou nuclear power plant and notably influenced by the thermal discharge. In general, fish diversity and abundance were higher in winter than in summer. RDA test analysis revealed that water temperature and dissolved oxygen were the primary environmental factors influencing fish distribution in summer. In winter, the influence of various factors is relatively balanced, with chlorophyll and Blue Green Algae Phycoerythrin (BGA PE) having a relatively greater impact than other factors. Our results offer valuable insights into enhancing fish diversity management in Dongshan Bay.

• Book : 17(3)
• Pub. Date : 2025
• Page : pp.452-452
• Keyword :

AbstractThe role of MUTYH, a DNA repair glycosylase in the pathogenesis of acute kidney injury (AKI) is unclear. In this study, it is found that MUTYH protein levels are significantly decreased in the kidneys of cisplatin‐ or folic acid (FA)‐induced mouse AKI models and patients with AKI. MUTYH deficiency aggravates renal dysfunction and tubular injury following cisplatin and FA treatment, along with the accumulation of 7, 8‐dihydro‐8‐oxoguanine (8‐oxoG) and impairs mitochondrial function. Importantly, the overexpression of type 2 MUTYH (nuclear) significantly ameliorates cisplatin‐induced apoptosis, oxidative stress, mitochondrial dysfunction, and DNA damage in vivo and in vitro. In contrast, overexpression of type 1 MUTYH (mitochondrial) shows a marginal effect against cisplatin‐induced injury, indicating the chief role of type 2 MUTYH in antagonizing AKI. Interestingly, the results also indicate that the upregulation of the E3 ligase HUWE1 causes the ubiquitination and degradation of MUTYH in tubular epithelial cells. HUWE1 knockout or treatment with the HUWE1 inhibitor BI8622 significantly protect against cisplatin‐induced AKI. Taken together, these results suggest that the ubiquitin E3 ligase HUWE1‐mediates ubiquitination and degradation of MUTYH can aggravate DNA damage in the nucleus and mitochondria and promote AKI. Targeting the HUWE1/MUTYH pathway may be a potential strategy for AKI treatment.

• Book : ()
• Pub. Date : 2025
• Page :
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AbstractHerpes simplex virus 1 (HSV-1) infects about 50-80% of the entire human population and persists in the neurons of affected individuals. A fraction of affected individuals suffer from recurrent cold sores caused by reactivating virus, in rare but severe cases the virus can cause encephalitis.During lytic infection, the virus relies on host factors such as RNA polymerase II and accessory proteins involved in transcription to express its genes and ensure successful replication. In general, RNA molecules in cells are bound by RNA-binding proteins (RBPs) during their entire lifecycle. Importantly, RBPs are increasingly described to also regulate transcription, an aspect long time outside the scope of investigations, especially during viral infections. Here, we examined the impact of five nuclear proteins (FUBP1, SLBP, SFPQ, SPT5 and SAF-B) with known RNA-binding activities on HSV-1 transcription. Additionally, we evaluated their importance for human adenovirus C5 (HAdV) growth to assess whether these host factors are specific to HSV-1 infections or might have broader relevance for the general transcription of dsDNA viruses.We show that the transcriptional elongation factor SPT5 coded by SUPT5H accumulates on HSV-1 genomes early during the infection and is required for the transcription of the immediate-early gene UL54. Its depletion affects also HAdV replication, indicating a general role in transcription of viruses that depend on the host transcriptional machinery.In contrast, depletion of the transcriptional repressor and paraspeckle protein SFPQ reduces UL54 RNA levels in HSV-1 infection, but does not cause significant changes in HAdV growth. Since SFPQ does not co-localize with HSV-1 genomes, this suggests a function not directly associated to viral DNA.

• Book : ()
• Pub. Date : 2025
• Page :
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This article introduces a novel biodegradable metasurface-loaded mobile phone back cover designed to reduce electromagnetic exposure and enhance antenna performance. The cover operates across the low GHz band (2–8 GHz) and the millimeter-wave band (22–25.6 GHz), utilizing polylactic acid as an eco-friendly substrate. Integrated with a six-port multiple-input multiple-output (MIMO) antenna system, the cover achieves port isolation above 20 dB in both bands. Specific absorption rate (SAR) analysis, performed using a human head model, shows significant reductions in electromagnetic exposure—61.1% in the low GHz band (from 1.06 W/kg to 0.412 W/kg) and 55% in the millimeter wave band (from 2.061 W/kg to 0.917 W/kg). Additionally, the metasurface cover enhances antenna gain and increases impedance bandwidth by 20% in the low GHz band and 8.3% in the millimeter-wave band. A comparative study highlights superior SAR reduction and bandwidth improvement of a metasurface on a biodegradable substrate over one on a silicone substrate. Prototypes of the MIMO antenna and the proposed cover were fabricated and tested, revealing strong alignment between simulated and measured results. These findings highlight the potential of biodegradable metasurface-based covers to deliver high-performance, sustainable solutions for mobile communication devices.

• Book : 18(4)
• Pub. Date : 2025
• Page : pp.730-730
• Keyword :

Abstract Background Treacher Collins syndrome (TCS, MIM #154500), a severe congenital disorder, predominantly involves dysplasia of craniofacial bones and is characterized by features such as downslanting palpebral fissures, lower eyelid colobomas, microtia, and other craniofacial anomalies. Despite its clinical importance, the underlying pathogenic mutations in TCS remain largely uncharacterized, representing a critical knowledge gap for researchers in the field. Results To address this, we performed mutation screening on a familial TCS case (trio) and 11 sporadic cases from a Chinese population. We identified 11 mutations predominantly localized to the central repeat domain (CRD) and the C-terminal domain (CTD, including the nuclear localization sequence) of TCOF1. The de novo frameshift mutation identified in the trio led to TCOF1 truncation, disrupting the central repeat domain crucial for binding transcriptional factors. Immunoprecipitation assays revealed that this pathogenic mutation attenuates the interaction between TCOF1 and transcription-related proteins, such as Pol II. Furthermore, cellular luciferase assays demonstrated that the mutation compromises the nuclear localization capability of TCOF1. Conclusions Our findings establish TCOF1 as the primary pathogenic gene in this Chinese TCS cohort, with mutations predominantly in the CRD and CTD, thereby expanding the known mutation spectrum of TCS and informing its prevention strategies.

• Book : 20(1)
• Pub. Date : 2025
• Page :
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ABSTRACTShrew moles (Uropsilus), belonging to subfamily Uropsilinae of family Talpidae, were predominantly found in Myanmar, Vietnam, Bhutan, and Southwestern China. However, the extent distribution range of species within Uropsilus remains unclear. In 2022, we collected 18 specimens of Uropsilus from the western mountains of Henan Province in central China. Based on the mitochondrial (CYT B) and nuclear (RAG1 + RAG2) genes, the phylogenetic relationships, divergence times, and species delimitation of Uropsilus were analyzed. The results showed that the genetic distance of CYT B between new species and other species of Uropsilus ranged from 8.44% to 18.23%; the new species was a distinct valid species and speciated in the early Pleistocene (2.16 Ma, 95% CI = 2.00–2.65) based on phylogenetic analyses. Morphologically, the new species was distinguishable from the other species of Uropsilus by its yellowish–brown dorsum and ash‐black venter, short tail, slender and curved zygomatic arch, upper inward‐curved I1, and lack of a gap between I1 and I2. The combined results of morphological and molecular phylogenetic analysis indicated that the samples from Henan Province represented a new species—Uropsilus funiushanensis sp. nov. The specimens collected from the mountainous area of western Henan Province and Shennongjia in Hubei Province were identified as the same species. We suggested the evolutionary mechanism of the dental formula of U. funiushanensis and U. soricilus groups should be explored in the future.

• Book : 15(2)
• Pub. Date : 2025
• Page :
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The ligand-binding domain (LBD) of the human nuclear receptor pregnane X receptor (PXR) is known to crystallize in two different crystal forms, P212121 or P43212, depending on the construct and the strategy used for protein production, as well as the presence or absence of the coactivator-derived peptide SRC-1. In order to facilitate biophysical and structural studies, a versatile construct was designed that allows access to both forms. This was achieved by introducing a thrombin cleavage site between the PXRLBD and the SRC-1 peptide fused to its C-terminus. Here, we describe the expression, purification and crystallization processes of this novel construct and report two new structures of PXRLBD that were obtained thanks to this strategy.

• Book : 81(3)
• Pub. Date : 2025
• Page :
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A novel polarization conversion radome based on dielectric-embedded metamaterial elements is proposed to decrease the size of antenna profiles. This radome is composed of two kinds of interlaced dielectric-embedded metamaterial elements to realize the polarization conversion and beam deflection. The structures and characteristics of two types of dielectric-embedded metamaterial elements have been studied and analyzed. By selecting an appropriate dielectric material and applying periodic boundary conditions to optimize these two kinds of dielectric-embedded metamaterial elements, the radome made up of these metamaterial elements eventually is mounted atop a square horn antenna. Simulation results indicate that the antenna radome enables the horn antenna to achieve polarization conversion and beam deflection at the operating frequency. The maximum beam deflection angle can be 29° within a gain reduction of 1 dB, while the axial ratio remains below 1.5 dB and the reflection coefficient continuously remains below −22 dB. Moreover, the power-handling capacity of each metamaterial element within the radome is above 60 kW.

• Book : 15(2)
• Pub. Date : 2025
• Page :
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