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The magnetic flux rope is among the most fundamental magnetic configurations in plasma. Although its presence after solar eruptions has been verified by spacecraft measurements near Earth, its formation on the Sun remains elusive, yet is critical to understanding a broad spectrum of phenomena. Here we study the dynamic formation of a magnetic flux rope during a classic two-ribbon flare. Its feet are identified unambiguously with conjugate coronal dimmings completely enclosed by irregular bright rings, which originate and expand outward from the far ends of flare ribbons. The expansion is associated with the rapid ribbon separation during the flare main phase. Counting magnetic flux through the feet and the ribbon-swept area reveals that the rope’s core is more twisted than its average of four turns. It propagates to the Earth as a typical magnetic cloud possessing a similar twist profile obtained by the Grad-Shafranov reconstruction of its three dimensional structure. Solar eruptions provide opportunities to study magnetic flux ropes, a structure of fundamental importance for both plasma physics and space weather. Here the authors reveal the dynamic formation of a flux rope through its footprint on the solar surface, revealing a highly twisted core structure.

Combined with data assimilation methods, a three-dimensional magnetohydrodynamic (MHD) numerical model is an effective tool to explore the mechanism of space weather. As a driver of space weather, the dynamic development of stream interaction regions (SIRs) near the orbit of Mars is an area of active research. In this study, we use the interplanetary total variation diminishing (TVD) MHD model to simulate solar wind parameters and model SIRs near Mars from 2021 November 15 to 2021 December 31. In this model, the MHD equations are solved by the conservation TVD Lax–Friedrichs scheme in a rotating spherical coordinate system with six component meshes used on the spherical shell. Solar wind velocity, density, temperature, and magnetic field strength are given at the inner boundary due to the characteristic waves propagating outward. We compared modeled results with observations from Mars Atmospheric Volatile EvolutioN (MAVEN) and Tianwen-1 (China’s first Mars exploration mission). Statistical analysis shows that the simulated results can capture SIRs and are in good agreement with observations; moreover, the assimilated results based on the Kalman filter improve the accuracy of numerical prediction compared with simulated results. This paper is the first attempt to simulate SIR events combined with MAVEN and Tianwen-1 in situ observations. Our work demonstrates that using the MHD model with the Kalman filter to reconstruct solar wind parameters can help us study the characteristics of SIRs near Mars, improve the capabilities of space weather forecasting, and understand the background solar wind environment.

We present a database of 12 fast forward interplanetary (IP) shocks observed in situ by radially aligned spacecraft (Venus Express, Wind, and/or STEREO) between 2006 and 2014. By analyzing shock magnetic compression ratios at different heliocentric distances, which serve as a common proxy for shock strength, we found that five events displayed a decrease in shock strength from Venus (at ∼0.72 au) to 1 au, five events showed no significant change within measurement uncertainties, and two events showed an increase near 1 au compared to Venus. Events that exhibited increased compression with distance may reflect specific interplanetary conditions that influence shock propagation and evolution. To investigate the causes of shock strengthening, we conducted a detailed case study of the 2011 March 18–21 shock event using a combination of multipoint remote-sensing and in situ observations. The analysis indicated that both the shock and its associated interplanetary coronal mass ejection (ICME) accelerated during their propagation, likely playing a major role in enhancing magnetic compression across the shock and contributing to the increased shock strength near 1 au. These findings highlight the importance of ICME kinematics in driving shock evolution in the inner heliosphere. The multi-spacecraft shock database compiled in this study also provides a valuable foundation for characterizing the radial evolution of IP shocks throughout the inner heliosphere.

Interplanetary coronal mass ejections (ICMEs) would significantly influence the space environment when they encounter different planets, with their magnetic field configurations determining the level of such influences. Unfortunately, due to the lack of in situ observations, the magnetic field configurations of ICMEs in the heliosphere are only available at some special points. In this work, we present a novel model, called the Magnetic Field Configuration Inferring model, to reconstruct the magnetic field configuration of ICMEs using in situ observations from radial aligned observers. Originally, the model utilizes in situ magnetic field observations at a specified point as input data. A flux rope fitting model is applied to derive the magnetic field configuration at this point. Subsequently, the drag-based model and self-similar expansion assumption are incorporated to obtain the ICME parameters at the target point. Finally, the magnetic field configuration of the ICME at the target point is obtained based on the magnetic field and geometry parameters. We validate the model using two ICME events observed by Venus Express (VEX) and STEREO-A, showing the case of backcasting (STEREO-A to VEX) and forecasting (VEX to STEREO-A). The model results are well consistent with the observations except for some minor differences. These results demonstrate the model’s ability to infer the magnetic field configuration of ICMEs at different points in the heliosphere based on in situ observations from one specified point. The model can be useful for space weather forecasting, especially for space weather predictions on other planets.

The magnetic orientation of coronal mass ejections (CMEs) is of great importance to understand their space weather effects. Although plenty of evidence suggests that CMEs can undergo significant rotation during the early phases of evolution in the solar corona, there are few reports that CMEs rotate in the interplanetary space. In this work, we use multispacecraft observations and a numerical simulation starting from the lower corona close to the solar surface to understand the CME event on 2021 December 4, with an emphatic investigation of its rotation. This event is observed as a partial halo CME from the back side of the Sun by coronagraphs and reaches the BepiColombo spacecraft and the Mars Atmosphere and Volatile EvolutioN/Tianwen-1 as a magnetic flux-rope-like structure. The simulation discloses that in the solar corona the CME is approximately a translational motion, while the interplanetary propagation process evidences a gradual change of axis orientation of the CME’s flux-rope-like structure. It is also found that the downside and the right flank of the CME moves with the fast solar wind, and the upside does in the slow-speed stream. The different parts of the CME with different speeds generate the nonidentical displacements of its magnetic structure, resulting in the rotation of the CME in the interplanetary space. Furthermore, at the right flank of the CME exists a corotating interaction region, which makes the orientation of the CME alter and also deviates from its route due to the CME. These results provide new insight into interpreting CMEs’ dynamics and structures during their traveling through the heliosphere.

The typical structure of a coronal mass ejection (CME) was identified as a three-part morphology, which includes a bright front, a dark cavity, and a bright core, with the cavity and the core generally regarded as flux rope and eruptive prominence. However, there are three-part CMEs that are not associated with prominences. In this work, we conduct a high-resolution simulation of the 2021 December 4 CME mimicked with a spheromak flux rope to investigate the formation of the three-part morphology in the solar corona. The CME, with no signatures of prominence at the beginning, evolves into a high–low–high-density structure, which appears in a coronagraph image as a bright front immediately followed by a dark cavity with a bright core behind. The moving and expanding spheromak flux rope sweeps up the solar wind plasma and meanwhile, the plasma at its utmost edge is compressed, which produces the high-density front overlying the flux rope. It is also found that the expansion of the flux rope is uneven, with strong expansion at its outlying area and weak expansion at its central and rear parts. The differential expansion rates lead to the distinct rarefaction rates of the plasma, which results in the formation of the low-density cavity and the high-density core within the flux rope. Our three-dimensional study for the first time demonstrates that the evolution of the flux rope can self-consistently generate the three-part density structure, which improves the understanding of CME’s morphologies in coronagraph images.

G protein-coupled receptors (GPCRs) are versatile and vital proteins involved in a wide array of physiological processes and responses, such as sensory perception (e.g., vision, taste, and smell), immune response, hormone regulation, and neurotransmission. Their diverse and essential roles in the body make them a significant focus for pharmaceutical research and drug development. Currently, approximately 35% of marketed drugs directly target GPCRs, underscoring their prominence as therapeutic targets. Recent advances in structural biology have substantially deepened our understanding of GPCR activation mechanisms and interactions with G-protein and arrestin signaling pathways. This review offers an in-depth exploration of both traditional and recent methods in GPCR structure analysis. It presents structure-based insights into ligand recognition and receptor activation mechanisms and delves deeper into the mechanisms of canonical and noncanonical signaling pathways downstream of GPCRs. Furthermore, it highlights recent advancements in GPCR-related drug discovery and development. Particular emphasis is placed on GPCR selective drugs, allosteric and biased signaling, polyphamarcology, and antibody drugs. Our goal is to provide researchers with a thorough and updated understanding of GPCR structure determination, signaling pathway investigation, and drug development. This foundation aims to propel forward-thinking therapeutic approaches that target GPCRs, drawing upon the latest insights into GPCR ligand selectivity, activation, and biased signaling mechanisms.

Colorectal cancer (CRC) poses a threat to the health of people worldwide. Long noncoding RNAs (lncRNAs) have been reported to play a key role in regulating carcinogenesis, including CRC. In this study, the levels of lncRNA FOXP4-AS1 were analyzed in CRC specimens and cells via qRT-PCR. The impacts of FOXP4-AS1 on CRC cell metastasis were investigated. Then, the silver staining assay, western blot, RIP, Co-IP, and immunofluorescence were conducted to explore and validate the molecular mechanisms by which FOXP4-AS1 affects CRC progression. We discovered that FOXP4-AS1 expression was markedly elevated in CRC. Functionally, FOXP4-AS1 knockdown suppressed CRC cell migration, invasion, and EMT. Also, FOXP4-AS1 silencing weakened CRC tumor growth in vivo. Mechanistically, we identified that FOXP4-AS1 functioned as a scaffold to simultaneously bind USP7 and ZEB1, and regulated the ubiquitination and expression of ZEB1 by binding to USP7. Rescue experiments demonstrated that USP7 inhibitor P005091 abolished the promotion of cell metastasis by FOXP4-AS1 overexpression. Furthermore, ZEB1 overexpression reversed the impact of silencing FOXP4-AS1 on cell metastasis. Collectively, our work revealed the molecular mechanism and role of FOXP4-AS1-mediated USP7-ZEB1 axis in CRC.

Carbon nanodots (CDs) have emerged as an alternative option for traditional nanocrystals due to their excellent optical properties and low toxicity. Nevertheless, high emission efficiency is a long‐lasting pursuit for CDs. Herein, CDs with near‐unity emission efficiency are prepared via atomic condensation of doped pyrrolic nitrogen, which can highly localize the excited states thus lead to the formation of bound excitons and the symmetry break of the π–electron conjugation. The short radiative lifetimes (<8 ns) and diffusion lengths (<50 nm) of the CDs imply that excitons can be efficiently localized by radiative recombination centers for a defect‐insensitive emission of CDs. By incorporating the CDs into polystyrene, flexible light‐converting films with a high solid‐state quantum efficiency of 84% and good resistance to water, heating, and UV light are obtained. With the CD–polymer films as light conversion layers, CD‐based white light‐emitting diodes (WLEDs) with a luminous efficiency of 140 lm W−1 and a flat‐panel illumination system with lighting sizes of more than 100 cm2 are achieved, matching state‐of‐the‐art nanocrystal‐based LEDs. These results pave the way toward carbon‐based luminescent materials for solid‐state lighting technology. Carbon nanodots (CDs) with near‐unity emission efficiency are prepared via atomic condensation of doped pyrrolic nitrogen, which can highly localize the excited states thus lead to the formation of bound excitons and the symmetry break of the π–electron conjugation. These results pave the way toward carbon‐based luminescent materials for solid‐state lighting technology.

Using the Stream Interaction Regions list from the Tianwen-1/Mars Orbiter Magnetometer (MOMAG) data between 2021 November and 2021 December and from Wind observations, we present an accurate prediction for the arrival time and in situ parameters of corotating interaction regions (CIRs) when the Earth and Mars have large longitudinal separations. Since CIRs were detected earlier at Earth than at Mars during the period examined, we employ Earth-based CIR detections for predicting CIR observations at Mars. The arrival time is calculated by the Parker spiral model under the assumption of steady corotation of the Sun and coronal holes, while the in situ parameters are derived from Wind data through radial dependent scaling laws. The CIR prediction results are compared to the actual observations obtained from the MOMAG and Mars Ion and Neutral Particle Analyzer instruments onboard Tianwen-1, as well as the Magnetometer and Solar Wind Ion Analyzer instruments onboard MAVEN. The predicted arrival time is close to the observed values with relative errors less than 10%, and the expected in situ data show a good consistency with the Martian measurements. The comparison results indicate that the prediction method has good performance and will be helpful for comparative analysis with Tianwen-1 observations at Mars in the future.