The surge-like eruption of a miniature filament

We report on the rare eruption of a miniature Hα filament that took the form of a surge. The filament first underwent a full development within 46 min and then began to erupt 9 min later, followed by a compact, impulsive X-ray class M2.2 flare with a two-ribbon nature only at the early eruption phase. During the eruption, its top rose, whereas the two legs remained rooted in the chromosphere and showed little swelling perpendicular to the rising direction. This led to a surge-like eruption with a narrow angular extent. Similar to the recent observations for standard and blowout X- ray jets by Moore et al., we thus define it as a ＂blowout Hα surge.＂ Furthermore, our observations showed that the eruption was associated with （1） a coronal mass ejection guided by a pre-existing streamer, （2） abrupt, significant, and persistent changes in the photospheric magnetic field around the filament, and （3） a sudden disappearance of a small pore. These observations thus provide evidence that a blowout surge is a small- scale version of a large-scale filament eruption in many aspects. Our observations further suggest that at least part of the Hα surges belong to blowout-type cases, and the exact distinction between the standard and blowout Hα surges is important in understanding their different origins and associated eruptive phenomena.

Synthesis and tumor resistance reverse activities of α-hederagenin-type ring-A fused pyrazine derivatives

α-Hederagenin(H),derived from Hedera nepalensis var.sinensis,is a pentacyclic oleane-type triterpenoid that exhibits clear cytotoxicity to different tumor cell lines.In this study,a series of novel C-28 derivatives of hederagenin(H) were designed and synthesized in attempt to develop potent tumor resistance reverse activities agents.Previous research showed that H6 displayed robust reverse activity for paclitaxel resistance in KBV cells.Importantly,Co-treatment of paclitaxel with H6 significantly reduced the tumor weight to 42%.Pleasingly,H6 enhanced the efficacy of paclitaxel against KBV cancer cell-derived xenograft tumors in nude mice.Mechanism studies had found that H6 activated permeability glycoprotein(P-gp) ATPase,reduced intracellular ATP levels and inhibited efflux of P-gp substrates,thus enhancing the antitumor activity of paclitaxel on KBV cells.Molecular docking analysis of homology P-gp and H6 then conducted using the Surflex-Dock module.H6 showed a high binding affinity docking score with a total score of 5.4148,much higher than that of H(0.1414).The nov.el C-28 derivatives of H was synthesized from H6 via three-step reaction.The reversal activity of all synthesized H derivatives were tested using the MTT assay.The results showed that the derivatives of nitrogen groups at C-28 displayed same even potent activity than parent compound H6.In addition,its underlying mechanism of action and in vivo activity are in explore.

Predicting the evolution of photospheric magnetic field in solar active regions using deep learning

The continuous observation of the magnetic field by the Solar Dynamics Observatory(SDO)/Helioseismic and Magnetic Imager(HMI)produces numerous image sequences in time and space.These sequences provide data support for predicting the evolution of photosphericmagnetic field.Based on the spatiotemporal long short-term memory(LSTM)network,we use the preprocessed data of photospheric magnetic field in active regions to build a prediction model for magnetic field evolution.Because of the elaborate learning and memory mechanism,the trained model can characterize the inherent relationships contained in spatiotemporal features.The testing results of the prediction model indicate that(1)the prediction pattern learned by the model can be applied to predict the evolution of new magnetic field in the next 6 hours that have not been trained,and predicted results are roughly consistent with real observed magnetic field evolution in terms of large-scale structure and movement speed;(2)the performance of the model is related to the prediction time;the shorter the prediction time,the higher the accuracy of the predicted results;(3)the performance of themodel is stable not only for active regions in the north and south but also for data in positive and negative regions.Detailed experimental results and discussions on magnetic flux emergence and magnetic neutral lines finally show that the proposed model could effectively predict the large-scale and short-term evolution of the photospheric magnetic field in active regions.Moreover,our study may provide a reference for the spatiotemporal prediction of other solar activities.

Magnetic interactions during sympathetic solar eruptions

We present the first evidence for occurrences of magnetic interactions between a jet, a filament and coronal loops during a complex event, in which two flares sequentially occurred at different positions of the same active region and were closely associated with two successive coronal mass ejections （CMEs）, respectively. The coronal loops were located outside but nearby the filament channel before the flares. The jet, originating from the first flare during its rise phase, not only hit the filament body but also met one of the ends of the loops. The filament then underwent an inclined eruption followed by the second flare and met the same loop end once more. Both the jet and the filament eruption were accompanied by the development of loop disturbances and the appearances of brightenings around the meeting site. In particular, the erupting filament showed clear manifestations of interactions with the loops. After a short holdup, only its portion passed through this site, while the other portion remained at the same place. Following the filament eruption and the loop disappearance, four dimmings were formed and located near their four ends. This is a situation that we define as ＂quadrupolar dimmings.＂ It appears that the two flares consisted of a sympathetic pair physically linked by the interaction between the jet and the filament, and their sympathy indicated that of the two CMEs. Moreover, it is very likely that the two sympathetic CMEs were simultaneously associated with the disappearing loops and the quadrupole dimmings.

Twist in a polar blowout jet

It is well known that some coronal jets exhibit helical structures and un- twisting. We attempt to inspect the origin of twist in a blowout jet. By means of multiwavelength and multi-angle observations from Solar Dynamics Observatory （SDO） and Solar Terrestrial Relations Observatory-Ahead （STEREO-A）, we firstly report a polar untwisting jet that is a blowout jet which leads to a jet-like coronal mass ejection. From the viewpoint of SDO, the jet shows clear untwisting behavior and two jet-spires. However, from the viewpoint of STEREO-A the jet actually comes from the whiplike prominence eruption and is followed by a white-light jet. Our observations indicate that twist in blowout jets may result from the erupting mini-prominences/mini- filaments in the jet base.

Insertion/deletion variants within the IGF2BP2 gene identified in reported genome-wide selective sweep analysis reveal a correlation with goat litter size

Insulin-like growth factor 2 m RNA-binding protein 2(IGF2 BP2,also called IMP2)plays an essential role in the development and maturation of germ cells and embryos and is a candidate gene for goat litter size,based on a previous genomewide selective sweep analysis.In this study,the m RNA expression level of IGF2 BP2 was found to be significantly higher in a single-lamb group than in a multi-lamb group.Insertions/deletions(indels)within the goat IGF2 BP2 gene,including P4-Ins-13 bp and P5-Del-12 bp,were verified in 918 Shaanbei White Cashmere(SBWC)female goats.The minor allelic frequencies(MAFs)of P4-Ins-13 bp and P5-Del-12 bp loci were 0.349 and 0.295,respectively.Analysis using the Chi-square(χ^(2))test showed that the genotype(χ^(2)=14.479,P=0.006)distribution of P4-Ins-13 bp was significantly different between the single-lamb and multi-lamb groups.Correlation analysis demonstrated that P4-Ins-13 bp was significantly associated with goat litter size(P=0.022),and individual goats with the homozygous deletion/deletion(DD)genotype produced more litters than other goats.Therefore,considered as a potential molecular marker significantly related to lambing traits,the P4-Ins-13 bp mutation of the goat IGF2 BP2 gene can be used in goat breeding with practical molecular marker-assisted selection(MAS)to optimize female reproduction and improve economic efficiency in the goat industry.