Changchun Observatory

Viral hepatitis remains a significant challenge for global public health and a leading cause of liver-related morbidity and mortality worldwide, with most cases caused by five hepatotropic viruses: hepatitis A, B, C, D, and E. The World Health Organization has established a goal to eliminate viral hepatitis as a public health threat by 2030. In recent years, advancements in our understanding of its pathogenesis have significantly propelled the development of antiviral drugs, particularly for hepatitis C, for which we now have highly effective therapies with cure rates exceeding 95%. However, achieving complete cures for hepatitis B and D continues to pose challenges, and effective treatments for hepatitis A and E are still lacking. A comprehensive understanding of the latest treatment advancements is crucial for guiding future drug development. This article reviews the most recent advancements in pharmacological interventions for viral hepatitis, summarizes current treatment methods, and provides an outlook on future research and therapeutic strategies, with the aim of improving patient outcomes and alleviating the global burden of liver diseases.

Soil nitrogen (N) availability and plant N uptake strategies are central to species adaptation and community assembly, yet how lithology shapes soil N supply and plant N uptake remains poorly understood. Here, we used 15N labeling to compare soil N supply and plant N uptake preferences in forests on soils developed from limestone and clastic rocks, respectively. Our results revealed significant contrasts in inorganic N pools: nitrate (NO3–) dominated in limestone soils, while ammonium (NH4+) was more abundant in red soils developed from clastic rocks. We attributed these differences to different soil N transformation pathways. Increased nitrification rates in limestone soils increased NO3– content, whereas red soils exhibited high mineralization but lower nitrification rates, leading to NH4+ dominating inorganic N. Forest plants in both limestone and red soils preferentially utilized NH4+ as their primary N source. However, plant in limestone soils took up significantly higher proportions of NO3– and glycine. Moreover, total N uptake rates by plants were significantly larger in limestone than red soils, suggesting a more efficient N acquisition strategy. Structural equation modeling indicated that lithology significantly affected soil N mineralization and nitrification by regulating soil pH and total N, thereby driving differences in soil inorganic N pools and ultimately plant N uptake. Our results provide evidence that lithology-driven variations in soil N supply can strongly affect plant N acquisition strategies.

Understanding how different land-use types shape soil bacterial communities and functions is critical for promoting sustainable land management and ecological restoration in fragile karst regions. This study evaluated the effects of different land-use types (pitaya [HF], maize [MF], sugarcane [SF], and paddy [PF] fields, forestland [FL], and grassland [AF]) on soil bacterial diversity, community composition, functional potentials, and co-occurrence networks in karst regions. The results showed that HF, MF, and PF exhibited the highest bacterial diversity (Shannon index), whereas SF had the lowest possibly because of continuous cropping and fertilization. Variance partitioning analysis revealed that soil bacterial community composition and functional potential were largely explained by the combined effects of land-use type and soil properties (34.8% for composition and 59.7% for functional potential), suggesting that land-use effects on bacterial communities are mainly mediated through changes in soil physicochemical properties. Hierarchical partitioning analysis further identified that soil texture, particularly silt and sand, and pH were the primary factors shaping bacterial community composition, whereas pH was the dominant driver of functional potential. Functional analysis indicated that HF enhanced nitrogen cycling processes, such as nitrification, aerobic nitrite oxidation, and aerobic ammonia oxidation; SF promoted carbon-related functions, including chemoheterotrophy, aerobic chemoheterotrophy, and cellulolysis; and PF favored iron and sulfur respiration. Co-occurrence network analysis demonstrated that HF had the most complex microbial interactions, likely attributable to no-tillage practices and favorable soil conditions, whereas PF showed the lowest network connectivity. Core bacterial groups such as Acidobacteria, Proteobacteria, Chloroflexi, and Actinobacteria, dominated in abundance but also functioned as keystone taxa, suggesting their critical roles in driving nutrient cycling and maintaining ecological stability. These findings suggest that no-till pitaya cultivation may help improve soil microbial diversity, functional potential, and ecological stability in fragile karst ecosystems, indicating its potential as a sustainable agricultural land-use practice. However, long-term monitoring and adaptive management are necessary to ensure sustained soil health.

Psychedelics are undergoing a renaissance as potential therapy for psychiatric disorders, with more than 200 clinical trials being studied across several countries1-3. However, the precise mechanisms by which these drugs bring about benefits and the potential clinical risks are not yet fully understood. The serotonin 2A receptor (5-HT2AR) was reported to be a Gq-coupled receptor and the primary interoceptive target of psychedelics4,5. Here we compared psychedelics and their non-hallucinogenic analogues (nHAs) using in vitro and in vivo approaches, finding that 5-HT2AR-mediated non-canonical Gi signalling is essential for hallucinogenic effect. We further presented five cryo-electron microscopy structures of 5-HT2AR-Gi/Gq in complex with psychedelics or nHAs. Structural analysis and pharmacological investigation revealed that a special contact between nHAs with 5-HT2AR mediated the signalling bias. Building on this insight, we identified a 2,5-dimethoxy-4-iodoamphetamine derivative, DOI-NBOMe, which exhibits potent and selective Gq-biased activity, and demonstrates promising therapeutic effects in mouse models without hallucinogenic effect. Our finding uncovers the functional mechanisms underlying the Gi signalling mediated by 5-HT2AR and provides valuable insights for designing psychedelic-based drugs with minimized risk from hallucinogenic effects.

Traditional aviation instrument screen anomaly detection methods primarily rely on manual inspection, which is inefficient and susceptible to subjective factors, and it is challenging to meet the requirements of modern aviation maintenance for high reliability and real-time performance. To this end, this paper proposes a lightweight self-supervised anomaly detection framework, AirNet, which is designed for aerial instrument screen image scenes to achieve efficient and accurate anomaly recognition. AirNet utilizes a feature adapter to enhance feature expression ability and injects Gaussian noise into the feature space to generate pseudo-abnormal samples, thereby improving discrimination ability. It combines a lightweight binary classification discriminator to realize anomaly detection and location. Experimental results on the self-built FIS-AD dataset and the public MVTec-AD and VisA datasets demonstrate that AirNet achieves performance comparable to that of state-of-the-art methods, while ensuring a lightweight design and high frame rate, with 98.5% image-level AUROC and 99.1% pixel-level AUROC. It shows good generalization ability and localization accuracy.

Abstract Seismicity offers insights into the mechanisms of magma generation, transportation, and the status of volcanic activity. Changbaishan is considered the most dangerous volcano in China. However, there was only one permanent seismic station (CBS) near Changbaishan Tianchi caldera before 2007. The limited number of stations posed a significant challenge in accurately locating earthquakes and herein investigating magma transport. In this study, we developed a Siamese Neural Network (SNN) with ConvMixer network (a hybrid SNN‐ConvMixer) that could regress back‐azimuth differences from continuous single‐station seismic recordings. Trained on paired reference–target events, this architecture mitigates the effect of limited lightweight data set. Comparative tests against conventional methods showed that our approach delivers relatively accurate estimates of back‐azimuth. We then combined its back‐azimuth predictions with traditional travel time grid‐search to infer hypocentral locations at Changbaishan volcano (CBV). Using this method, we successfully located 10,790 local seismic events beneath CBV 2000 and 2007. The spatiotemporal distribution of earthquakes indicates intense seismicity from 2002 to 2003 from deep to shallow depth, consistent with magma upward during the period of volcanic unrest. This deep learning technique demonstrates the potential for seismic analysis on other planets where seismic station networks are sparse.

This work aims to analyze how hyperons affect neutrino radiation properties in nucleonic direct URCA processes, with the goal of providing useful references for identifying evidence of hyperons in astronomical observations. This analysis is conducted using the GM1 and NL3 parameter sets under the SU(6) and SU(3) flavor symmetries within the relativistic mean field theory framework. In conjunction with the inferred mass and radius values of PSRs J1231-1411, J0030+0451, and J0740+6620, our results indicate that nucleonic direct URCA processes are absent in PSR J1231-1411 due to momentum conservation violation. In the hyperon-containing PSR J0030+0451 (NL3 parameter set), the nucleonic direct URCA processes involving / would occur. A large inferred mass span induces hyperon fraction variations, which affect neutrino emissivity. If the inferred mass of PSR J0030+0451 exceeds approximately 1.8 , the neutrino luminosity of the nucleonic direct URCA processes under the SU(3) flavor symmetry remains nearly the same as that in npeµ matter, independent of hyperons. However, it shows an obvious hyperon dependence under the SU(6) spin-flavor symmetry. For hyperon-containing J0740+6620, the nucleonic direct URCA processes under the SU(3) flavor symmetry in the GM1 parameter set predict a faster decline in neutrino luminosity with the hyperonic fraction than in npeµ matter, and under the SU(6) spin-flavor symmetry in the NL3 parameter set, it shows a monotonic decreasing trend. The research indicates that the hyperonic fraction significantly affects the neutrino radiation properties of nucleonic direct URCA processes in neutron stars. Different-mass pulsars (e.g., PSRs J1231-1411, J0030+0451, J0740+6620) exhibit distinct behaviors of nucleonic direct URCA processes, depending on inferred masses/radii, parameter sets, and theoretical models.

Abstract The roles of terrain in the convection initiations (CIs) under weak synoptic forcing remain unclear. Take as an example an extreme rainfall event on the eastern slope of Wushan mountain and nearby regions on 25 July 2019 that resulted from a linear convective system originating from the emergence of several convective cells triggered along the eastern slope of Wushan mountain. The influence of the topographic thermodynamic and dynamic forcing on the afternoon (1500–1630 Beijing Time [ UTC + 8 h]) CIs associated with this event has been systematically studied in this study. Results show that the CIs occur in highly unstable and moderate wind shear environments and are closely correlated with the acceleration of upstream low‐level southeasterly winds, which are induced by the superposition effect of the large‐scale pressure field and mesoscale thermally forced mountain–plains solenoid (MPS) circulation. The large‐scale pressure field accelerates the low‐level southerly winds by increasing the northward pressure gradient force, while the mesoscale MPS circulation in the afternoon strengthens the low‐level easterly winds by increasing the westward pressure gradient force. As the upstream airflows are accelerated, the strong convergence uplift due to the topographic dynamic blocking triggers new convections in the transition region from blocked to unblocked flows. The numerical sensitivity experiments further highlight the key role of the thermodynamic forcing of Wushan mountain in the low‐level airflow acceleration and CIs. Overall, the topographic thermodynamic effect plays a relatively more important role than the dynamic forcing under a weak synoptic forcing situation given the low‐level airflow acceleration is a preceding factor.