BACKGROUND In an era leaning toward a personalized alignment of total knee arthroplasty,coronal plane alignment of the knee(CPAK)phenotypes for each population are studied;furthermore,other possible variables affectin...BACKGROUND In an era leaning toward a personalized alignment of total knee arthroplasty,coronal plane alignment of the knee(CPAK)phenotypes for each population are studied;furthermore,other possible variables affecting the alignment,such as ankle joint alignment,should be considered.AIM To determine CPAK distribution in the North African(Egyptian)population with knee osteoarthritis and to assess ankle joint line orientation(AJLO)adaptations across different CPAK types.METHODS A cross-sectional study was conducted on patients with primary knee osteoarthritis and normal ankle joints.Radiographic parameters included the mechanical lateral distal femoral angle,medial proximal tibial angle,and the derived calculations of joint line obliquity(JLO)and arithmetic hip-knee-ankle angle(aHKA).The tibial plafond horizontal angle(TPHA)was used for AJLO assessment,where 0°is neutral(type N),<0°is varus(type A),and>0°is valgus(type B).The nine CPAK types were further divided into 27 subtypes after incorporating the three AJLO types.RESULTS A total of 527 patients(1054 knees)were included for CPAK classification,and 435 patients(870 knees and ankles)for AJLO assessment.The mean age was 57.2±7.8 years,with 79.5%females.Most knees(76.4%)demonstrated varus alignment(mean aHKA was-5.51°±4.84°)and apex distal JLO(55.3%)(mean JLO was 176.43°±4.53°).CPAK types I(44.3%),IV(28.6%),and II(10%)were the most common.Regarding AJLO,70.2%of ankles exhibited varus orientation(mean TPHA was-5.21°±6.45°).The most frequent combined subtypes were CPAK type I-A(33.7%),IV-A(21.5%),and I-N(6.9%).A significant positive correlation was found between the TPHA and aHKA(r=0.40,P<0.001).CONCLUSION In this North African cohort,varus knee alignment with apex distal JLO and varus AJLO predominated.CPAK types I,IV,and II were the most common types,while subtypes I-A,IV-A,and I-N were commonly occurring after incorporating AJLO types;furthermore,the AJLO was significantly correlated to aHKA.展开更多
Pulpotomy,which belongs to vital pulp therapy,has become a strategy for managing pulpitis in recent decades.This minimally invasive treatment reflects the recognition of preserving healthy dental pulp and optimizing l...Pulpotomy,which belongs to vital pulp therapy,has become a strategy for managing pulpitis in recent decades.This minimally invasive treatment reflects the recognition of preserving healthy dental pulp and optimizing long-term patient-centered outcomes.Pulpotomy is categorized into partial pulpotomy(PP),the removal of a partial segment of the coronal pulp tissue,and full pulpotomy(FP),the removal of whole coronal pulp,which is followed by applying the biomaterials onto the remaining pulp tissue and ultimately restoring the tooth.Procedural decisions for the amount of pulp tissue removal or retention depend on the diagnostic of pulp vitality,the overall treatment plan,the patient’s general health status,and pulp inflammation reassessment during operation.This statement represents the consensus of an expert committee convened by the Society of Cariology and Endodontics,Chinese Stomatological Association.It addresses the current evidence to support the application of pulpotomy as a potential alternative to root canal treatment(RCT)on mature permanent teeth with pulpitis from a biological basis,the development of capping biomaterial,and the diagnostic considerations to evidence-based medicine.This expert statement intends to provide a clinical protocol of pulpotomy,which facilitates practitioners in choosing the optimal procedure and increasing their confidence in this rapidly evolving field.展开更多
In this paper,we perform a follow-up investigation of the solar eruption originating from active region 13575 on 2024 February 9.The primary eruption of a hot channel generates an X3.4 class flare,a full-halo coronal ...In this paper,we perform a follow-up investigation of the solar eruption originating from active region 13575 on 2024 February 9.The primary eruption of a hot channel generates an X3.4 class flare,a full-halo coronal mass ejection(CME),and an extreme-ultraviolet(EUV)wave.Interaction between the wave and a quiescent prominence(QP)leads to a large-amplitude,transverse oscillation of QP.After the transverse oscillation,QP loses equilibrium and rises up.The ascending motion of the prominence is coherently detected and tracked up to∼1.68 R_(⊙)by the Solar UltraViolet Imager onboard the GOES-16 spacecraft and up to∼2.2 R_(⊙)by the Solar Corona Imager(SCI_UV)of the LyαSolar Telescope onboard the ASO-S spacecraft.The velocity increases linearly from 12.3 to 68.5 km s^(−1)at 18:30 UT.The sympathetic eruption of QP drives the second CME with a typical three-part structure.The bright core comes from the eruptive prominence,which could be further observed up to∼3.3 R_(⊙) by the Large Angle Spectroscopic Coronagraph onboard the Solar and Heliospheric Observatory mission.The leading edge of the second CME accelerates continuously from∼120 to∼277 km s^(−1).The EUV wave plays an important role in linking the primary eruption with the sympathetic eruption.展开更多
We present an analysis of the magnetic mechanism of an X6.4-class confined flare in NOAA Active Region(AR)13590 on 2024 February 22.Despite a pre-existing magnetic flux rope(MFR)embedded within a null-point topology,t...We present an analysis of the magnetic mechanism of an X6.4-class confined flare in NOAA Active Region(AR)13590 on 2024 February 22.Despite a pre-existing magnetic flux rope(MFR)embedded within a null-point topology,the flare produced only a localized jet without an associated coronal mass ejection.Using data from the Solar Dynamics Observatory and nonlinear force-free field extrapolations,we traced the formation and evolution of the MFR,which developed under photospheric shearing motions but remained weakly twisted(with twist number being lower than 1.3)and below the thresholds for kink instability.Meanwhile,the MFR is located at heights where the decay index(n≤1.0)of the overlying field was insufficient to trigger torus instability.Furthermore,we calculated two important parameters measuring the non-potentiality of the AR,one is the ratio of the free energy to the potential-field energy,and the other is the ratio of the non-potential helicity to the square of the magnetic flux.Both the two parameters were significantly lower than critical values for eruptive flares.These factors,combined with the stabilizing influence of the strong overlying field,confined the MFR and limited the eruption to a jet.Our findings highlight the importance of both local magnetic properties and global energy constraints in determining the eruptive potential of solar flares.展开更多
Major solar plasma disturbances are subjected to Lomb-Scargle periodogram and wavelet analysis to determine the occurrence frequency.These disruptions include interplanetary coronal mass ejection,sudden storm commence...Major solar plasma disturbances are subjected to Lomb-Scargle periodogram and wavelet analysis to determine the occurrence frequency.These disruptions include interplanetary coronal mass ejection,sudden storm commencement,high-speed streams,corotating interaction regions,interplanetary shocks and Forbush decreases.We included information on all of the aforementioned solar disturbances for the last six solar cycles,from 1965 to 2023,for this study.Our findings reveal some intriguing and noteworthy results that clearly distinguish between even and odd-numbered solar cycles.The study suggests that the Sun behaves differently in odd and even-numbered solar cycles as it comes from the massive solar eruptions.During even-numbered solar cycles,variations with a period of∼44 days are prominently observed in addition to solar rotation(∼27 days)and extended solar(∼36 days)rotation.However,in addition to solar rotation,prolonged solar rotation,and periods of around 44 days,we also detect a number of intermittent changes with nearly comparable amplitude during the oddnumbered solar cycles.The findings also demonstrate that,in contrast to odd-numbered solar cycles,the emissions rate of these disruptions is more distinct and predictable during even-numbered solar cycles.展开更多
The Solar Close Observations and Proximity Experiments(SCOPE)mission will send a spacecraft into the solar atmosphere at a low altitude of just 5 R☉from the solar center.It aims to elucidate the mechanisms behind sol...The Solar Close Observations and Proximity Experiments(SCOPE)mission will send a spacecraft into the solar atmosphere at a low altitude of just 5 R☉from the solar center.It aims to elucidate the mechanisms behind solar eruptions and coronal heating,and to directly measure the coronal magnetic field.The mission will perform in situ measurements of the current sheet between coronal mass ejections and their associated solar flares,and energetic particles produced by either reconnection or fast-mode shocks driven by coronal mass ejections.This will help to resolve the nature of reconnections in current sheets,and energetic particle acceleration regions.To investigate coronal heating,the mission will observe nano-flares on scales smaller than 70 km in the solar corona and regions smaller than 40 km in the photosphere,where magnetohydrodynamic waves originate.To study solar wind acceleration mechanisms,the mission will also track the process of ion charge-state freezing in the solar wind.A key achievement will be the observation of the coronal magnetic field at unprecedented proximity to the solar photosphere.The polar regions will also be observed at close range,and the inner edge of the solar system dust disk may be identified for the first time.This work presents the detailed background,science,and mission concept of SCOPE and discusses how we aim to address the questions mentioned above.展开更多
Decameter-hectometric(DH)Type Ⅱ bursts,arising from coronal mass ejection(CME)-driven shock waves,are crucial for understanding solar-terrestrial interactions and space weather forecasting.This study provides a compr...Decameter-hectometric(DH)Type Ⅱ bursts,arising from coronal mass ejection(CME)-driven shock waves,are crucial for understanding solar-terrestrial interactions and space weather forecasting.This study provides a comprehensive statistical analysis of CMEs associated with DH type Ⅱ solar radio bursts during Solar Cycle 24(2009–2019),utilizing data from the Wind/WAVES,Solar TErrestrial RElations Observatory/SWAVES,and Solar and Heliospheric Observatory/LASCO catalogs.Analyzing 180 events,we report key spectral and kinematic properties,including a mean CME speed of(1058±531)km s^(−1) and a mean width of(288.39±99.3),with 62%classified as halo CMEs.About 12%of the total CMEs are accelerated,58%of them are decelerated,and 30%of them are constant.Similarly,CMEs having a speed≤800 km s^(−1) are constant,and those with speed≥800 km s^(−1) are decelerated.DH type Ⅱ bursts displayed a mean starting frequency of(12,169.72±4939)kHz,ending frequency of(2152.69±3022.07)kHz,bandwidth of(10,017±5353)kHz,and an average duration of(345.62±453)minutes.A power-law relationship was established between the drift rate(df/dt)and burst duration(D),characterized by df/dt=2749.07·D^(−0.88),highlighting the inverse dependence of drift rate on burst longevity.This suggests a dynamic interplay between shock parameters and the ambient solar corona.The findings underscore the persistent and robust spectral coverage of CME-driven shocks,offering new insights into their evolution and impact on the heliospheric environment.展开更多
BACKGROUND Back pain and sciatica are common complaints that often require imaging for accurate diagnosis and management.Conventional lumbar magnetic resonance imaging(MRI)protocols typically include sagittal and axia...BACKGROUND Back pain and sciatica are common complaints that often require imaging for accurate diagnosis and management.Conventional lumbar magnetic resonance imaging(MRI)protocols typically include sagittal and axial T1 and T2 sequences;however,these may miss certain pathologies.The addition of coronal short tau inversion recovery(STIR)sequences offers the potential to enhance the detection of both spinal and extra-spinal abnormalities,thereby improving clinical decisionmaking and patient outcomes.AIM To evaluate the impact of adding coronal STIR sequences to routine lumbar MRI in diagnosing back pain and sciatica.METHODS We prospectively analyzed data from patients aged 6 and older presenting with back pain or sciatica who underwent lumbar spine MRI at our institution.The standardized MRI protocol utilized included sagittal and axial T1 and T2 sequences,complemented by a coronal STIR sequence.Data on structural abnormalities were collected,reviewed,and analyzed using counts,percentages,and Fisher's exact test for categorical variables.RESULTS Our cohort comprised 274 patients(115 males,159 females;mean age 44.91 years).Notably,39 patients exhibited abnormalities across all sequences,while 72.63%showed normal findings on the coronal STIR sequence.Importantly,30.29%of cases were diagnosed as normal without the coronal STIR,and 36 patients with normal T1 and T2 sequences presented abnormalities on the coronal STIR.The coronal STIR sequence successfully identified 26 spinal and 10 non-spinal pathologies,including 17 cases of sacroiliitis,with a significant association(P<0.0001)between sacroiliitis diagnosis and abnormalities visible solely on this sequence.CONCLUSION Integrating coronal STIR into routine lumbar MRI enhances detection of hidden spinal and extra-spinal pathologies,improves patient management,and offers a cost-effective,practical upgrade with significant diagnostic and clinical value.展开更多
We investigate the relationship between the magnitudes of Forbush decreases(FDs)and solar-geomagnetic characteristics using daily-averaged galactic cosmic ray(GCR)data from Inuvick(INVK)and Magadan(MGDN)neutron monito...We investigate the relationship between the magnitudes of Forbush decreases(FDs)and solar-geomagnetic characteristics using daily-averaged galactic cosmic ray(GCR)data from Inuvick(INVK)and Magadan(MGDN)neutron monitor(NM)stations to aid in counting the case of GCR flux intensity modulation.The FDs,obtained with an automated new computer software algorithm from daily-averaged GCR data from the IZMIRAN common website:http://cr0.izmiran.ru/common,at INVK(224)and MGDN(229)NM stations,from 1998 to 2002,were used in the present work.The associated solar-geomagnetic parameters of the same time range were obtained from the OMNI website.A statistical analytical method was employed to test the link between FD amplitudes and solargeomagnetic variables.We observed negative trends in FD-IMF,FD-SWS,FD-Kp,FD-SSN and FD-SI,while a positive relation was indicated in FD-Dst at both stations.All are statistically significant at a 95%confidence level.The results obtained here imply that solar emission characteristics impact the GCR flux intensity modulation.展开更多
Before solar eruptions,a short-term slow-rise phase is often observed,during which the pre-eruption structure ascends at speeds much greater than the photospheric motions but much less than those of the eruption phase...Before solar eruptions,a short-term slow-rise phase is often observed,during which the pre-eruption structure ascends at speeds much greater than the photospheric motions but much less than those of the eruption phase.Numerical magnetohydrodynamic (MHD) simulations of the coronal evolution driven by photospheric motions up to eruptions have been used to explain the slow-rise phase,but their bottom driving speeds are much larger than realistic photospheric values.Therefore,it remains an open question how the excessively fast bottom driving impacts the slow-rise phase.Here we modeled the slow-rise phase before eruption initiated from a continuously sheared magnetic arcade.In particular,we performed a series of experiments with the bottom driving speed unprecedentedly approaching the photospheric value of around 1 km s^(-1).The simulations confirmed that the slowrise phase is an ideal MHD process,i.e.,a manifestation of the growing expansion of the sheared arcade in the process of approaching a fully open field state.The overlying field line above the core flux has a slow-rise speed modulated by the driving speed’s magnitude but is always over an order of magnitude larger than the driving speed.The core field also expands with speed much higher than the driving speed but much lower than that of the overlying field.By incrementally reducing the bottom-driving speed to realistic photospheric values,we anticipate better matches between the simulated slow-rise speeds and some observed ones.展开更多
Partitioning the solar cycle into ascending and descending phases,we examine the solar cycle distribution of the north-south(N-S)asymmetry in the source locations of super geomagnetic storms(SGSs;Dst≤-250 nT)during 1...Partitioning the solar cycle into ascending and descending phases,we examine the solar cycle distribution of the north-south(N-S)asymmetry in the source locations of super geomagnetic storms(SGSs;Dst≤-250 nT)during 1932-2018.We found that during the ascending phases,SGS source locations were predominantly in the northern hemisphere(NH),exhibiting significant N-S asymmetry.For the SGSs in the descending phases,source locations of the SGSs dominated in the NH and N-S asymmetry was only significant in the western hemisphere.For the period from 1932 to 2018,the source locations of SGSs were predominantly in the NH,and the N-S asymmetry was significant.The cumulative numbers of SGSs originating from the two hemispheres were strongly anticorrelated during the ascending phases,descending phases,and the entire period from 1932 to 2018.For the source locations of SGSs with different intensities,significant N-S asymmetries were observed in the source location distribution.Specifically,for all SGSs,SGSs with-400 nT<Dst≤-300 nT,and SGSs with Dst≤-300 nT,the NH exhibited a higher number of events compared to the southern hemisphere(SH),indicating a dominance of SGSs in the NH.From the perspective of the evolution of N-S asymmetry with the solar cycle,the source locations of the SGSs always dominated in the NH during the ascending phases.However,during solar cycles 17-19 and 21,the source locations of the SGSs dominated in the NH,while during solar cycles 20,22,and 23 the source locations of the SGSs dominated in the SH.From the perspective of N-S asymmetry for Solar Cycles 17-23,solar activity across the two hemispheres is largely balanced.However,the solar activities manifested by CMEs that can trigger SGSs during Solar Cycles 17-23 were predominantly in the NH.Therefore,factors beyond solar activity,such as the propagation of the CMEs from the Sun to the Earth,likely contribute to the observed N-S asymmetric distribution of the source locations of SGSs.展开更多
A 50 mm balloon-borne white-light coronagraph(BBWLC)to observe white-light solar corona over the altitude range from 1.08 R_(⊙)to 1.50 R_(⊙)has recently been indigenously developed by Yunnan Observatories in collabo...A 50 mm balloon-borne white-light coronagraph(BBWLC)to observe white-light solar corona over the altitude range from 1.08 R_(⊙)to 1.50 R_(⊙)has recently been indigenously developed by Yunnan Observatories in collaboration with Shandong University(in Weihai)and Changchun Institute of Optics,Fine Mechanics and Physics,which will significantly improve the ability of China to detect and measure the inner corona.On 2022 October 4,its first scientific flight took place at the Dachaidan area in Qinghai province of China.We briefly describe the BBWLC mission including its optical design,mechanical structure,pointing system,the first flight and results associated with the data processing approach.Preliminary analysis of the data shows that BBWLC imaged the K-corona with three streamer structures on the west limb of the Sun.To further confirm the coronal signals obtained by BBWLC,comparisons were made with observations of the K-coronagraph of the High Altitude Observatory and the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory.We conclude that BBWLC eventually observed the white-light corona in its first scientific flight.展开更多
We examined the heliolatitude distribution and North-South(N-S)asymmetry of Ground Level Enhancement(GLE)event source locations from 1942 to 2024,finding distinct patterns between the periods 1942–1979 and1980–2024....We examined the heliolatitude distribution and North-South(N-S)asymmetry of Ground Level Enhancement(GLE)event source locations from 1942 to 2024,finding distinct patterns between the periods 1942–1979 and1980–2024.Between 1942 and 1979,33 GLE events were recorded:5 from the southern hemisphere within[S3,S11]and 28 from the northern hemisphere within[N7,N37].The southeast quadrant was devoid of any source locations for GLE events.45.4%of the source locations of the GLE events were within the latitudinal range of[S15,N15].The remaining source locations of the GLE events were distributed at latitudes above 15°in the northern hemisphere.Between 1980 and 2024,43 GLE events were recorded:25 from the southern hemisphere and 18 from the northern hemisphere,with all events above 30°latitude originating from the northern hemisphere.Approximately 44.2%of the source locations of the GLE events were distributed within the latitudinal band[S15,N15].Over the period from 1942 to 2024,44.7%within[S15,N15],63.2%within[S20,N20],80.3%within[S25,N25],88.2%within[S30,N30],and 11.8%at latitudes above 30°.N-S asymmetry was significant at latitudes above 0°,5°,10°,15°,20°and 30°,with northern hemisphere dominance.Moreover,a strong inverse correlation exists between the number of GLE events from the northern and southern hemispheres at latitudes above 0°,5°,10°,15°,20°,25°and 30°.展开更多
Objectives Coroners in England and Wales have a duty to write Prevention of Future Deaths(PFDs)reports when they believe that action should be taken to prevent similar deaths.We conducted a systematic case series of t...Objectives Coroners in England and Wales have a duty to write Prevention of Future Deaths(PFDs)reports when they believe that action should be taken to prevent similar deaths.We conducted a systematic case series of the reports involving maternal deaths to characterise these deaths in terms of demographics,explore the concerns raised by the coroners and understand what actions were reported by organisations in their responses to the coroner.Methods All coroners'PFDs published between July 2013 and 1 August 2023 in England and Wales were collected and reviewed(n=4435).Reports were searched for keywords related to maternal deaths.Case information was extracted into pre-specified domains and compared to other data on maternal deaths.Results Twenty nine(n=29)cases were found involving a maternal death.The median age at death was 33.5 years(IQR 29±36 years)and three-quarters(75.9%)of deaths occurred in hospitals.The most common cause of death was haemorrhage.Coroners frequently voiced concerns around the failure to provide appropriate treatment(48.2%)and failure of timely escalation(37.9%).Specific lessons we have highlighted include gaps in national guidance,failure to follow national protocols,communication issues and lack of resources or staff cover.Only 38%of PFDs had published responses from the organisations they were sent to.When organisations did respond to the coroner,80%reported that they implemented changes,including publishing new local policies,increasing training or committing to increased staffing.Conclusions Poor response rates to PFDs indicate underutilisation of these reports as a resource for improvement in maternal care.PFDs highlighted gaps in obstetric care and national guidance which,if appropriately addressed and regularly and routinely monitored,could prevent similar deaths.展开更多
Coronal shear fractures of the distal humerus are rare,complex fractures that can be technically challenging to manage. They usually result from a low-energy fall and direct compression of the distal humerus by the ra...Coronal shear fractures of the distal humerus are rare,complex fractures that can be technically challenging to manage. They usually result from a low-energy fall and direct compression of the distal humerus by the radial head in a hyper-extended or semi-flexed elbow or from spontaneous reduction of a posterolateral subluxation or dislocation. Due to the small number of soft tissue attachments at this site, almost all of these fractures are displaced. The incidence of distal humeral coronal shear fractures is higher among women because of the higher rate of osteoporosis in women and the difference in carrying angle between men and women. Distal humeral coronal shear fractures may occur in isolation, may be part of a complex elbow injury, or may be associated with injuries proximal or distal to the elbow. An associated lateral collateral ligament injury is seen in up to 40% and an associated radial head fracture is seen in up to 30% of these fractures. Given the complex nature of distal humeral coronal shear fractures, there is preference for operative management. Operative fixation leads to stable anatomic reduction, restores articular congruity, and allows initiation of early range-of-motion movements in the majority of cases. Several surgical exposure and fixation techniques are available to reconstruct the articular surface fol owing distal humeral coronal shear fractures. The lateral extensile approach and fixation with countersunk headless compression screws placed in an anterior-to-posterior fashion are commonly used. We have found a two-incision approach(direct anterior and lateral) that results in less soft tissue dissection and better outcomes than the lateral extensile approach in our experience. Stiffness, pain, articular incongruity, arthritis, and ulnohumeral instability may result if reduction is non-anatomic or if fixation fails.展开更多
As one of the payloads for the Advanced Space-based Solar Observatory(ASO-S)mission,the Lyman-alpha(Lyα)Solar Telescope(LST)is aimed at imaging the Sun and the inner corona up to 2.5 R⊙(mean solar radius)in both the...As one of the payloads for the Advanced Space-based Solar Observatory(ASO-S)mission,the Lyman-alpha(Lyα)Solar Telescope(LST)is aimed at imaging the Sun and the inner corona up to 2.5 R⊙(mean solar radius)in both the Lyα(121.6 nm)and visible wavebands with high temporo-spatial resolution,mainly targeting solar flares,coronal mass ejections(CMEs)and filaments/prominences.LST observations allow us to trace solar eruptive phenomena from the disk center to the inner corona,to study the relationships between eruptive prominences/filaments,solar flares and CMEs,to explore the dynamical processes and evolution of solar eruptions,to diagnose solar winds,and to derive physical parameters of the solar atmosphere.LST is actually an instrument suite,which consists of a Solar Disk Imager(SDI),a Solar Corona Imager(SCI),a White-light Solar Telescope(WST)and two Guide Telescopes(GTs).This is the first paper in a series of LST-related papers.In this paper,we introduce the scientific objectives,present an overview of the LST payload and describe the planned observations.The detailed design and data along with potential diagnostics are described in the second(Paper II)and third(Paper III)papers,respectively,appearing in this issue.展开更多
The Lyman-alpha Solar Telescope(LST)is one of the three payloads onboard the Advanced Space-based Solar Observatory(ASO-S)mission.It aims at imaging the Sun from the disk center up to 2.5 R⊙targeting solar eruptions,...The Lyman-alpha Solar Telescope(LST)is one of the three payloads onboard the Advanced Space-based Solar Observatory(ASO-S)mission.It aims at imaging the Sun from the disk center up to 2.5 R⊙targeting solar eruptions,particularly coronal mass ejections(CMEs),solar flares,prominences/filaments and related phenomena,as well as the fast and slow solar wind.The most prominent speciality of LST is the simultaneous observation of the solar atmosphere in both Lyαand white light(WL)with high temporospatial resolution both on the solar disk and the inner corona.New observations in the Lyαline together with traditional WL observations will provide us with many new insights into solar eruptions and solar wind.LST consists of a Solar Corona Imager(SCI)with a field of view(FOV)of 1.1–2.5 R⊙,a Solar Disk Imager(SDI)and a full-disk White-light Solar Telescope(WST)with an identical FOV up to 1.2 R⊙.SCI has a dual waveband in Lyα(121.6±10 nm)and in WL(700±40 nm),while SDI works in the Lyαwaveband of 121.6±7.5 nm and WST works in the violet narrow-band continuum of 360±2.0 nm.To produce high quality science data,careful ground and in-flight calibrations are required.We present our methods for different calibrations including dark field correction,flat field correction,radiometry,instrumental polarization and optical geometry.Based on the data calibration,definitions of the data levels and processing procedures for the defined levels from raw data are described.Plasma physical diagnostics offer key ingredients to understand ejecta and plasma flows in the inner corona,as well as different features on the solar disk including flares,filaments,etc.Therefore,we are making efforts to develop various tools to detect the different features observed by LST,and then to derive their physical parameters,for example,the electron density and temperature of CMEs,the outflow velocity of the solar wind,and the hydrogen density and mass flows of prominences.Coordinated observations and data analyses with the coronagraphs onboard Solar Orbiter,PROBA-3,and Aditya are also briefly discussed.展开更多
Our newly developed CESE MHD model is used to simulate sun-earth connection event with the well-studied 12 May 1997 CME event as an example. The main features and approximations of our numerical model are as follows：...Our newly developed CESE MHD model is used to simulate sun-earth connection event with the well-studied 12 May 1997 CME event as an example. The main features and approximations of our numerical model are as follows： （1） The modifed conservation element and solution element （CESE） numerical scheme in spherical geometry is implemented in our code. （2） The background solar wind is derived from a 3D time-dependent numerical MHD model by input measured photospheric magnetic fields. （3） Transient disturbances are derived from solar surface by introducing a mass flow of hot plasma. The numerical simulation has enabled us to predict the arrival of the interplanetary shock and provided us with a relatively satisfactory comparison with the WIND spacecraft observations.展开更多
As one of the three payloads for the Advanced Space-based Solar Observatory(ASO-S)mission,the Lyman-alpha(Lyα)Solar Telescope(LST)is composed of three instruments:a Solar Corona Imager(SCI),a LyαSolar Disk Imager(SD...As one of the three payloads for the Advanced Space-based Solar Observatory(ASO-S)mission,the Lyman-alpha(Lyα)Solar Telescope(LST)is composed of three instruments:a Solar Corona Imager(SCI),a LyαSolar Disk Imager(SDI)and a full-disk White-light Solar Telescope(WST).When working in-orbit,LST will simultaneously perform high-resolution imaging observations of all regions from the solar disk to the inner corona up to 2.5 R⊙(R⊙stands for the mean solar radius)with a spatial resolution of 4.8′′and 1.2′′for coronal and disk observations,respectively,and a temporal resolution of 30–120 s and 1–120 s for coronal and disk observations,respectively.The maximum exposure time can be up to20 s due to precise pointing and image stabilization function.Among the three telescopes of LST,SCI is a dual-waveband coronagraph simultaneously and independently observing the inner corona in the HI Lyα(121.6±10 nm)line and white light(WL)(700±40 nm)wavebands by using a narrowband Lyαbeam splitter and has a field of view(FOV)from 1.1 to 2.5 R⊙.The stray-light suppression level can attain<10^-6 B⊙(B⊙is the mean brightness of the solar disk)at 1.1 R⊙and≤5×10^-8 B⊙at 2.5 R⊙.SDI and WST are solar disk imagers working in the Lyαline and 360.0 nm wavebands,respectively,which adopt an off-axis two-mirror reflective structure with an FOV up to 1.2 R⊙,covering the inner coronal edge area and relating to coronal imaging.We present the up-to-date design for the LST payload.展开更多
The characteristics of magnetohydrodynamic fast wave propagation in the solar stratified atmosphere are studied by the ray tracing method. The propagation behaviour of the wavefronts is described in detail. A magnetic...The characteristics of magnetohydrodynamic fast wave propagation in the solar stratified atmosphere are studied by the ray tracing method. The propagation behaviour of the wavefronts is described in detail. A magnetic field incorporating the characteristics field spreading expected in flux tubes is used, which represents the main feature of an active region. Partly ionization is considered beside the stratified solar atmosphere consisting chromosphere, transition region and corona. The study may explain the characteristics in observations of Moreton and extraultraviolet image telescope （EIT） waves. The wavefront incurred by the disturbance initialized at the base of the transition region propagates fast initially due to strong magnetic field, and it slows down when arriving beyond the region of flux-tube. Meanwhile, the wave propagates in the corona with a more consistent speed, as seen in the observation of EIT waves. The speeds and propagated characteristics in chromosphere and corona of the wavefronts are in agreement with those observed in H~ Moreton and EIT waves, respectively.展开更多
基金approved by Institutional Review Board of Faculty of Medicine in Assiut University,No.04-2024-300470.
文摘BACKGROUND In an era leaning toward a personalized alignment of total knee arthroplasty,coronal plane alignment of the knee(CPAK)phenotypes for each population are studied;furthermore,other possible variables affecting the alignment,such as ankle joint alignment,should be considered.AIM To determine CPAK distribution in the North African(Egyptian)population with knee osteoarthritis and to assess ankle joint line orientation(AJLO)adaptations across different CPAK types.METHODS A cross-sectional study was conducted on patients with primary knee osteoarthritis and normal ankle joints.Radiographic parameters included the mechanical lateral distal femoral angle,medial proximal tibial angle,and the derived calculations of joint line obliquity(JLO)and arithmetic hip-knee-ankle angle(aHKA).The tibial plafond horizontal angle(TPHA)was used for AJLO assessment,where 0°is neutral(type N),<0°is varus(type A),and>0°is valgus(type B).The nine CPAK types were further divided into 27 subtypes after incorporating the three AJLO types.RESULTS A total of 527 patients(1054 knees)were included for CPAK classification,and 435 patients(870 knees and ankles)for AJLO assessment.The mean age was 57.2±7.8 years,with 79.5%females.Most knees(76.4%)demonstrated varus alignment(mean aHKA was-5.51°±4.84°)and apex distal JLO(55.3%)(mean JLO was 176.43°±4.53°).CPAK types I(44.3%),IV(28.6%),and II(10%)were the most common.Regarding AJLO,70.2%of ankles exhibited varus orientation(mean TPHA was-5.21°±6.45°).The most frequent combined subtypes were CPAK type I-A(33.7%),IV-A(21.5%),and I-N(6.9%).A significant positive correlation was found between the TPHA and aHKA(r=0.40,P<0.001).CONCLUSION In this North African cohort,varus knee alignment with apex distal JLO and varus AJLO predominated.CPAK types I,IV,and II were the most common types,while subtypes I-A,IV-A,and I-N were commonly occurring after incorporating AJLO types;furthermore,the AJLO was significantly correlated to aHKA.
基金supported by the National Natural Science Foundation of China(82170941 and 82370948 to Lu Zhang,82071110 and 82230029 to Zhi Chen)the National Key R&D Program of China(2018YFC1105100)。
文摘Pulpotomy,which belongs to vital pulp therapy,has become a strategy for managing pulpitis in recent decades.This minimally invasive treatment reflects the recognition of preserving healthy dental pulp and optimizing long-term patient-centered outcomes.Pulpotomy is categorized into partial pulpotomy(PP),the removal of a partial segment of the coronal pulp tissue,and full pulpotomy(FP),the removal of whole coronal pulp,which is followed by applying the biomaterials onto the remaining pulp tissue and ultimately restoring the tooth.Procedural decisions for the amount of pulp tissue removal or retention depend on the diagnostic of pulp vitality,the overall treatment plan,the patient’s general health status,and pulp inflammation reassessment during operation.This statement represents the consensus of an expert committee convened by the Society of Cariology and Endodontics,Chinese Stomatological Association.It addresses the current evidence to support the application of pulpotomy as a potential alternative to root canal treatment(RCT)on mature permanent teeth with pulpitis from a biological basis,the development of capping biomaterial,and the diagnostic considerations to evidence-based medicine.This expert statement intends to provide a clinical protocol of pulpotomy,which facilitates practitioners in choosing the optimal procedure and increasing their confidence in this rapidly evolving field.
基金supported by the Strategic Priority Research Program on Space Science,Chinese Academy of Sciencessupported by the National Key R&D Program of China 2022YFF0503003(2022YFF0503000),2021YFA1600500 (2021YFA1600502)+3 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences,grant No.XDB0560000the National Natural Science Foundation of China (NSFC,grant Nos.12373065,12203102,12403064,and 12403068)Natural Science Foundation of Jiangsu Province (BK20231510,BK20241707)Supported by the Specialized Research Fund for State Key Laboratories,and Yunnan Key Laboratory of Solar Physics and Space Science under the grant No.YNSPCC202206
文摘In this paper,we perform a follow-up investigation of the solar eruption originating from active region 13575 on 2024 February 9.The primary eruption of a hot channel generates an X3.4 class flare,a full-halo coronal mass ejection(CME),and an extreme-ultraviolet(EUV)wave.Interaction between the wave and a quiescent prominence(QP)leads to a large-amplitude,transverse oscillation of QP.After the transverse oscillation,QP loses equilibrium and rises up.The ascending motion of the prominence is coherently detected and tracked up to∼1.68 R_(⊙)by the Solar UltraViolet Imager onboard the GOES-16 spacecraft and up to∼2.2 R_(⊙)by the Solar Corona Imager(SCI_UV)of the LyαSolar Telescope onboard the ASO-S spacecraft.The velocity increases linearly from 12.3 to 68.5 km s^(−1)at 18:30 UT.The sympathetic eruption of QP drives the second CME with a typical three-part structure.The bright core comes from the eruptive prominence,which could be further observed up to∼3.3 R_(⊙) by the Large Angle Spectroscopic Coronagraph onboard the Solar and Heliospheric Observatory mission.The leading edge of the second CME accelerates continuously from∼120 to∼277 km s^(−1).The EUV wave plays an important role in linking the primary eruption with the sympathetic eruption.
基金supported by Guangdong Basic and Applied Basic Research Foundation(2025A1515011353)the Specialized Research Fund for State Key Laboratory of Solar Activity and Space Weather.
文摘We present an analysis of the magnetic mechanism of an X6.4-class confined flare in NOAA Active Region(AR)13590 on 2024 February 22.Despite a pre-existing magnetic flux rope(MFR)embedded within a null-point topology,the flare produced only a localized jet without an associated coronal mass ejection.Using data from the Solar Dynamics Observatory and nonlinear force-free field extrapolations,we traced the formation and evolution of the MFR,which developed under photospheric shearing motions but remained weakly twisted(with twist number being lower than 1.3)and below the thresholds for kink instability.Meanwhile,the MFR is located at heights where the decay index(n≤1.0)of the overlying field was insufficient to trigger torus instability.Furthermore,we calculated two important parameters measuring the non-potentiality of the AR,one is the ratio of the free energy to the potential-field energy,and the other is the ratio of the non-potential helicity to the square of the magnetic flux.Both the two parameters were significantly lower than critical values for eruptive flares.These factors,combined with the stabilizing influence of the strong overlying field,confined the MFR and limited the eruption to a jet.Our findings highlight the importance of both local magnetic properties and global energy constraints in determining the eruptive potential of solar flares.
文摘Major solar plasma disturbances are subjected to Lomb-Scargle periodogram and wavelet analysis to determine the occurrence frequency.These disruptions include interplanetary coronal mass ejection,sudden storm commencement,high-speed streams,corotating interaction regions,interplanetary shocks and Forbush decreases.We included information on all of the aforementioned solar disturbances for the last six solar cycles,from 1965 to 2023,for this study.Our findings reveal some intriguing and noteworthy results that clearly distinguish between even and odd-numbered solar cycles.The study suggests that the Sun behaves differently in odd and even-numbered solar cycles as it comes from the massive solar eruptions.During even-numbered solar cycles,variations with a period of∼44 days are prominently observed in addition to solar rotation(∼27 days)and extended solar(∼36 days)rotation.However,in addition to solar rotation,prolonged solar rotation,and periods of around 44 days,we also detect a number of intermittent changes with nearly comparable amplitude during the oddnumbered solar cycles.The findings also demonstrate that,in contrast to odd-numbered solar cycles,the emissions rate of these disruptions is more distinct and predictable during even-numbered solar cycles.
基金supported by the National Key R&D Program of China (2022YFF0503800)National Natural Science Foundation of China grants (12073073, 11933009, 12273107 and U2031141)+6 种基金grants associated with the Yunnan Revitalization Talent Support Programthe Foundation of the Chinese Academy of Sciences (Light of West China Program)the Yunling Scholar Project of Yunnan Provincethe Yunnan Province Scientist Workshop of Solar Physicsthe Applied Basic Research of Yunnan Province grants (202101AT070018 and 2019FB005)supported by the National Natural Science Foundation of China grants (12273107 and U2031141)the Yunnan Key Laboratory of Solar Physics and Space Science (202205AG070009)
文摘The Solar Close Observations and Proximity Experiments(SCOPE)mission will send a spacecraft into the solar atmosphere at a low altitude of just 5 R☉from the solar center.It aims to elucidate the mechanisms behind solar eruptions and coronal heating,and to directly measure the coronal magnetic field.The mission will perform in situ measurements of the current sheet between coronal mass ejections and their associated solar flares,and energetic particles produced by either reconnection or fast-mode shocks driven by coronal mass ejections.This will help to resolve the nature of reconnections in current sheets,and energetic particle acceleration regions.To investigate coronal heating,the mission will observe nano-flares on scales smaller than 70 km in the solar corona and regions smaller than 40 km in the photosphere,where magnetohydrodynamic waves originate.To study solar wind acceleration mechanisms,the mission will also track the process of ion charge-state freezing in the solar wind.A key achievement will be the observation of the coronal magnetic field at unprecedented proximity to the solar photosphere.The polar regions will also be observed at close range,and the inner edge of the solar system dust disk may be identified for the first time.This work presents the detailed background,science,and mission concept of SCOPE and discusses how we aim to address the questions mentioned above.
基金supported by the National Key R&D Program of China(2021YFA1600500 and 2021YFA1600503)sponsored by the CAS-TWAS President Fellowship Programpartially supported by the Tianchi Talent Program of the Xinjiang Uygur Autonomous Region of China.
文摘Decameter-hectometric(DH)Type Ⅱ bursts,arising from coronal mass ejection(CME)-driven shock waves,are crucial for understanding solar-terrestrial interactions and space weather forecasting.This study provides a comprehensive statistical analysis of CMEs associated with DH type Ⅱ solar radio bursts during Solar Cycle 24(2009–2019),utilizing data from the Wind/WAVES,Solar TErrestrial RElations Observatory/SWAVES,and Solar and Heliospheric Observatory/LASCO catalogs.Analyzing 180 events,we report key spectral and kinematic properties,including a mean CME speed of(1058±531)km s^(−1) and a mean width of(288.39±99.3),with 62%classified as halo CMEs.About 12%of the total CMEs are accelerated,58%of them are decelerated,and 30%of them are constant.Similarly,CMEs having a speed≤800 km s^(−1) are constant,and those with speed≥800 km s^(−1) are decelerated.DH type Ⅱ bursts displayed a mean starting frequency of(12,169.72±4939)kHz,ending frequency of(2152.69±3022.07)kHz,bandwidth of(10,017±5353)kHz,and an average duration of(345.62±453)minutes.A power-law relationship was established between the drift rate(df/dt)and burst duration(D),characterized by df/dt=2749.07·D^(−0.88),highlighting the inverse dependence of drift rate on burst longevity.This suggests a dynamic interplay between shock parameters and the ambient solar corona.The findings underscore the persistent and robust spectral coverage of CME-driven shocks,offering new insights into their evolution and impact on the heliospheric environment.
文摘BACKGROUND Back pain and sciatica are common complaints that often require imaging for accurate diagnosis and management.Conventional lumbar magnetic resonance imaging(MRI)protocols typically include sagittal and axial T1 and T2 sequences;however,these may miss certain pathologies.The addition of coronal short tau inversion recovery(STIR)sequences offers the potential to enhance the detection of both spinal and extra-spinal abnormalities,thereby improving clinical decisionmaking and patient outcomes.AIM To evaluate the impact of adding coronal STIR sequences to routine lumbar MRI in diagnosing back pain and sciatica.METHODS We prospectively analyzed data from patients aged 6 and older presenting with back pain or sciatica who underwent lumbar spine MRI at our institution.The standardized MRI protocol utilized included sagittal and axial T1 and T2 sequences,complemented by a coronal STIR sequence.Data on structural abnormalities were collected,reviewed,and analyzed using counts,percentages,and Fisher's exact test for categorical variables.RESULTS Our cohort comprised 274 patients(115 males,159 females;mean age 44.91 years).Notably,39 patients exhibited abnormalities across all sequences,while 72.63%showed normal findings on the coronal STIR sequence.Importantly,30.29%of cases were diagnosed as normal without the coronal STIR,and 36 patients with normal T1 and T2 sequences presented abnormalities on the coronal STIR.The coronal STIR sequence successfully identified 26 spinal and 10 non-spinal pathologies,including 17 cases of sacroiliitis,with a significant association(P<0.0001)between sacroiliitis diagnosis and abnormalities visible solely on this sequence.CONCLUSION Integrating coronal STIR into routine lumbar MRI enhances detection of hidden spinal and extra-spinal pathologies,improves patient management,and offers a cost-effective,practical upgrade with significant diagnostic and clinical value.
文摘We investigate the relationship between the magnitudes of Forbush decreases(FDs)and solar-geomagnetic characteristics using daily-averaged galactic cosmic ray(GCR)data from Inuvick(INVK)and Magadan(MGDN)neutron monitor(NM)stations to aid in counting the case of GCR flux intensity modulation.The FDs,obtained with an automated new computer software algorithm from daily-averaged GCR data from the IZMIRAN common website:http://cr0.izmiran.ru/common,at INVK(224)and MGDN(229)NM stations,from 1998 to 2002,were used in the present work.The associated solar-geomagnetic parameters of the same time range were obtained from the OMNI website.A statistical analytical method was employed to test the link between FD amplitudes and solargeomagnetic variables.We observed negative trends in FD-IMF,FD-SWS,FD-Kp,FD-SSN and FD-SI,while a positive relation was indicated in FD-Dst at both stations.All are statistically significant at a 95%confidence level.The results obtained here imply that solar emission characteristics impact the GCR flux intensity modulation.
基金supported by the National Natural Science Foundation of China (NSFC,Grant No.42174200)Shenzhen Science and Technology Program (grant No.RCJC20210609104422048)+1 种基金Shenzhen Key Laboratory Launching Project (No.ZDSYS20210702140800001)Guangdong Basic and Applied Basic Research Foundation(2023B1515040021)。
文摘Before solar eruptions,a short-term slow-rise phase is often observed,during which the pre-eruption structure ascends at speeds much greater than the photospheric motions but much less than those of the eruption phase.Numerical magnetohydrodynamic (MHD) simulations of the coronal evolution driven by photospheric motions up to eruptions have been used to explain the slow-rise phase,but their bottom driving speeds are much larger than realistic photospheric values.Therefore,it remains an open question how the excessively fast bottom driving impacts the slow-rise phase.Here we modeled the slow-rise phase before eruption initiated from a continuously sheared magnetic arcade.In particular,we performed a series of experiments with the bottom driving speed unprecedentedly approaching the photospheric value of around 1 km s^(-1).The simulations confirmed that the slowrise phase is an ideal MHD process,i.e.,a manifestation of the growing expansion of the sheared arcade in the process of approaching a fully open field state.The overlying field line above the core flux has a slow-rise speed modulated by the driving speed’s magnitude but is always over an order of magnitude larger than the driving speed.The core field also expands with speed much higher than the driving speed but much lower than that of the overlying field.By incrementally reducing the bottom-driving speed to realistic photospheric values,we anticipate better matches between the simulated slow-rise speeds and some observed ones.
基金supported by the National Natural Science Foundation of China(NSFC,grant Nos.41774085,41074132,41274193 and 41674166)the Special Fund of the Institute of Geophysics,China Earthquake Administration(grant Nos.DQJB22X12 and DQJB24X25)。
文摘Partitioning the solar cycle into ascending and descending phases,we examine the solar cycle distribution of the north-south(N-S)asymmetry in the source locations of super geomagnetic storms(SGSs;Dst≤-250 nT)during 1932-2018.We found that during the ascending phases,SGS source locations were predominantly in the northern hemisphere(NH),exhibiting significant N-S asymmetry.For the SGSs in the descending phases,source locations of the SGSs dominated in the NH and N-S asymmetry was only significant in the western hemisphere.For the period from 1932 to 2018,the source locations of SGSs were predominantly in the NH,and the N-S asymmetry was significant.The cumulative numbers of SGSs originating from the two hemispheres were strongly anticorrelated during the ascending phases,descending phases,and the entire period from 1932 to 2018.For the source locations of SGSs with different intensities,significant N-S asymmetries were observed in the source location distribution.Specifically,for all SGSs,SGSs with-400 nT<Dst≤-300 nT,and SGSs with Dst≤-300 nT,the NH exhibited a higher number of events compared to the southern hemisphere(SH),indicating a dominance of SGSs in the NH.From the perspective of the evolution of N-S asymmetry with the solar cycle,the source locations of the SGSs always dominated in the NH during the ascending phases.However,during solar cycles 17-19 and 21,the source locations of the SGSs dominated in the NH,while during solar cycles 20,22,and 23 the source locations of the SGSs dominated in the SH.From the perspective of N-S asymmetry for Solar Cycles 17-23,solar activity across the two hemispheres is largely balanced.However,the solar activities manifested by CMEs that can trigger SGSs during Solar Cycles 17-23 were predominantly in the NH.Therefore,factors beyond solar activity,such as the propagation of the CMEs from the Sun to the Earth,likely contribute to the observed N-S asymmetric distribution of the source locations of SGSs.
基金supported by the National Key R&D Program of China No.2022YFF0503800the Strategic Priority Research Program of the Chinese Academy of Sciences(grant Nos.XDA17040507 and XDB0560000)+1 种基金NSFC grant 11933009the Yunnan Province Scientist Workshop of Solar Physics,the Yunnan Key Laboratory of Solar Physics and Space Science(202205AG070009)。
文摘A 50 mm balloon-borne white-light coronagraph(BBWLC)to observe white-light solar corona over the altitude range from 1.08 R_(⊙)to 1.50 R_(⊙)has recently been indigenously developed by Yunnan Observatories in collaboration with Shandong University(in Weihai)and Changchun Institute of Optics,Fine Mechanics and Physics,which will significantly improve the ability of China to detect and measure the inner corona.On 2022 October 4,its first scientific flight took place at the Dachaidan area in Qinghai province of China.We briefly describe the BBWLC mission including its optical design,mechanical structure,pointing system,the first flight and results associated with the data processing approach.Preliminary analysis of the data shows that BBWLC imaged the K-corona with three streamer structures on the west limb of the Sun.To further confirm the coronal signals obtained by BBWLC,comparisons were made with observations of the K-coronagraph of the High Altitude Observatory and the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory.We conclude that BBWLC eventually observed the white-light corona in its first scientific flight.
基金supported by the National Natural Science Foundation of China(grant Nos.42374092,41074132,41274193,41474166,41774195,and 41874187)the Special Fund of the Institute of Geophysics,China Earthquake Administration(Grant Number DQJB22X12)。
文摘We examined the heliolatitude distribution and North-South(N-S)asymmetry of Ground Level Enhancement(GLE)event source locations from 1942 to 2024,finding distinct patterns between the periods 1942–1979 and1980–2024.Between 1942 and 1979,33 GLE events were recorded:5 from the southern hemisphere within[S3,S11]and 28 from the northern hemisphere within[N7,N37].The southeast quadrant was devoid of any source locations for GLE events.45.4%of the source locations of the GLE events were within the latitudinal range of[S15,N15].The remaining source locations of the GLE events were distributed at latitudes above 15°in the northern hemisphere.Between 1980 and 2024,43 GLE events were recorded:25 from the southern hemisphere and 18 from the northern hemisphere,with all events above 30°latitude originating from the northern hemisphere.Approximately 44.2%of the source locations of the GLE events were distributed within the latitudinal band[S15,N15].Over the period from 1942 to 2024,44.7%within[S15,N15],63.2%within[S20,N20],80.3%within[S25,N25],88.2%within[S30,N30],and 11.8%at latitudes above 30°.N-S asymmetry was significant at latitudes above 0°,5°,10°,15°,20°and 30°,with northern hemisphere dominance.Moreover,a strong inverse correlation exists between the number of GLE events from the northern and southern hemispheres at latitudes above 0°,5°,10°,15°,20°,25°and 30°.
文摘Objectives Coroners in England and Wales have a duty to write Prevention of Future Deaths(PFDs)reports when they believe that action should be taken to prevent similar deaths.We conducted a systematic case series of the reports involving maternal deaths to characterise these deaths in terms of demographics,explore the concerns raised by the coroners and understand what actions were reported by organisations in their responses to the coroner.Methods All coroners'PFDs published between July 2013 and 1 August 2023 in England and Wales were collected and reviewed(n=4435).Reports were searched for keywords related to maternal deaths.Case information was extracted into pre-specified domains and compared to other data on maternal deaths.Results Twenty nine(n=29)cases were found involving a maternal death.The median age at death was 33.5 years(IQR 29±36 years)and three-quarters(75.9%)of deaths occurred in hospitals.The most common cause of death was haemorrhage.Coroners frequently voiced concerns around the failure to provide appropriate treatment(48.2%)and failure of timely escalation(37.9%).Specific lessons we have highlighted include gaps in national guidance,failure to follow national protocols,communication issues and lack of resources or staff cover.Only 38%of PFDs had published responses from the organisations they were sent to.When organisations did respond to the coroner,80%reported that they implemented changes,including publishing new local policies,increasing training or committing to increased staffing.Conclusions Poor response rates to PFDs indicate underutilisation of these reports as a resource for improvement in maternal care.PFDs highlighted gaps in obstetric care and national guidance which,if appropriately addressed and regularly and routinely monitored,could prevent similar deaths.
文摘Coronal shear fractures of the distal humerus are rare,complex fractures that can be technically challenging to manage. They usually result from a low-energy fall and direct compression of the distal humerus by the radial head in a hyper-extended or semi-flexed elbow or from spontaneous reduction of a posterolateral subluxation or dislocation. Due to the small number of soft tissue attachments at this site, almost all of these fractures are displaced. The incidence of distal humeral coronal shear fractures is higher among women because of the higher rate of osteoporosis in women and the difference in carrying angle between men and women. Distal humeral coronal shear fractures may occur in isolation, may be part of a complex elbow injury, or may be associated with injuries proximal or distal to the elbow. An associated lateral collateral ligament injury is seen in up to 40% and an associated radial head fracture is seen in up to 30% of these fractures. Given the complex nature of distal humeral coronal shear fractures, there is preference for operative management. Operative fixation leads to stable anatomic reduction, restores articular congruity, and allows initiation of early range-of-motion movements in the majority of cases. Several surgical exposure and fixation techniques are available to reconstruct the articular surface fol owing distal humeral coronal shear fractures. The lateral extensile approach and fixation with countersunk headless compression screws placed in an anterior-to-posterior fashion are commonly used. We have found a two-incision approach(direct anterior and lateral) that results in less soft tissue dissection and better outcomes than the lateral extensile approach in our experience. Stiffness, pain, articular incongruity, arthritis, and ulnohumeral instability may result if reduction is non-anatomic or if fixation fails.
基金supported by the National Natural Science Foundation of China (Grant Nos.11427803 and U1731241)the CAS Strategic Pioneer Program on Space Science (Grant Nos.XDA04061003, XDA04076100, XDA15052200, XDA15320103 and XDA15320301)
文摘As one of the payloads for the Advanced Space-based Solar Observatory(ASO-S)mission,the Lyman-alpha(Lyα)Solar Telescope(LST)is aimed at imaging the Sun and the inner corona up to 2.5 R⊙(mean solar radius)in both the Lyα(121.6 nm)and visible wavebands with high temporo-spatial resolution,mainly targeting solar flares,coronal mass ejections(CMEs)and filaments/prominences.LST observations allow us to trace solar eruptive phenomena from the disk center to the inner corona,to study the relationships between eruptive prominences/filaments,solar flares and CMEs,to explore the dynamical processes and evolution of solar eruptions,to diagnose solar winds,and to derive physical parameters of the solar atmosphere.LST is actually an instrument suite,which consists of a Solar Disk Imager(SDI),a Solar Corona Imager(SCI),a White-light Solar Telescope(WST)and two Guide Telescopes(GTs).This is the first paper in a series of LST-related papers.In this paper,we introduce the scientific objectives,present an overview of the LST payload and describe the planned observations.The detailed design and data along with potential diagnostics are described in the second(Paper II)and third(Paper III)papers,respectively,appearing in this issue.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11522328, 11473070, 11427803 and U1731241)the CAS Strategic Pioneer Program on Space Science (Grant Nos. XDA15010600, XDA15052200, XDA15320103 and XDA15320301)the National Key Research and Development Program (2018YFA0404202)
文摘The Lyman-alpha Solar Telescope(LST)is one of the three payloads onboard the Advanced Space-based Solar Observatory(ASO-S)mission.It aims at imaging the Sun from the disk center up to 2.5 R⊙targeting solar eruptions,particularly coronal mass ejections(CMEs),solar flares,prominences/filaments and related phenomena,as well as the fast and slow solar wind.The most prominent speciality of LST is the simultaneous observation of the solar atmosphere in both Lyαand white light(WL)with high temporospatial resolution both on the solar disk and the inner corona.New observations in the Lyαline together with traditional WL observations will provide us with many new insights into solar eruptions and solar wind.LST consists of a Solar Corona Imager(SCI)with a field of view(FOV)of 1.1–2.5 R⊙,a Solar Disk Imager(SDI)and a full-disk White-light Solar Telescope(WST)with an identical FOV up to 1.2 R⊙.SCI has a dual waveband in Lyα(121.6±10 nm)and in WL(700±40 nm),while SDI works in the Lyαwaveband of 121.6±7.5 nm and WST works in the violet narrow-band continuum of 360±2.0 nm.To produce high quality science data,careful ground and in-flight calibrations are required.We present our methods for different calibrations including dark field correction,flat field correction,radiometry,instrumental polarization and optical geometry.Based on the data calibration,definitions of the data levels and processing procedures for the defined levels from raw data are described.Plasma physical diagnostics offer key ingredients to understand ejecta and plasma flows in the inner corona,as well as different features on the solar disk including flares,filaments,etc.Therefore,we are making efforts to develop various tools to detect the different features observed by LST,and then to derive their physical parameters,for example,the electron density and temperature of CMEs,the outflow velocity of the solar wind,and the hydrogen density and mass flows of prominences.Coordinated observations and data analyses with the coronagraphs onboard Solar Orbiter,PROBA-3,and Aditya are also briefly discussed.
基金Supported by the National Natural Science Foundation of China under Grant Nos 40621003, 40536029, 40504020, and 40523006, the National Basic Research Programme of China under Grant No 2006CB806304, and the CAS International Partnership Programme for Creative Research Teams. Dr S. T. Wu is supported by AFOSR under Grant No FA 9550-07-1-0468 and NSF ATM036115.
文摘Our newly developed CESE MHD model is used to simulate sun-earth connection event with the well-studied 12 May 1997 CME event as an example. The main features and approximations of our numerical model are as follows： （1） The modifed conservation element and solution element （CESE） numerical scheme in spherical geometry is implemented in our code. （2） The background solar wind is derived from a 3D time-dependent numerical MHD model by input measured photospheric magnetic fields. （3） Transient disturbances are derived from solar surface by introducing a mass flow of hot plasma. The numerical simulation has enabled us to predict the arrival of the interplanetary shock and provided us with a relatively satisfactory comparison with the WIND spacecraft observations.
基金supported by Chinese Academy of Sciences (CAS)supported by the National Natural Science Foundation of China (Grant Nos. 11427803, U1731241, U1731114 and U1531106)the CAS Strategic Pioneer Program on Space Science (Grant Nos. XDA04076100, XDA15052200, XDA15320103 and XDA15320301)
文摘As one of the three payloads for the Advanced Space-based Solar Observatory(ASO-S)mission,the Lyman-alpha(Lyα)Solar Telescope(LST)is composed of three instruments:a Solar Corona Imager(SCI),a LyαSolar Disk Imager(SDI)and a full-disk White-light Solar Telescope(WST).When working in-orbit,LST will simultaneously perform high-resolution imaging observations of all regions from the solar disk to the inner corona up to 2.5 R⊙(R⊙stands for the mean solar radius)with a spatial resolution of 4.8′′and 1.2′′for coronal and disk observations,respectively,and a temporal resolution of 30–120 s and 1–120 s for coronal and disk observations,respectively.The maximum exposure time can be up to20 s due to precise pointing and image stabilization function.Among the three telescopes of LST,SCI is a dual-waveband coronagraph simultaneously and independently observing the inner corona in the HI Lyα(121.6±10 nm)line and white light(WL)(700±40 nm)wavebands by using a narrowband Lyαbeam splitter and has a field of view(FOV)from 1.1 to 2.5 R⊙.The stray-light suppression level can attain<10^-6 B⊙(B⊙is the mean brightness of the solar disk)at 1.1 R⊙and≤5×10^-8 B⊙at 2.5 R⊙.SDI and WST are solar disk imagers working in the Lyαline and 360.0 nm wavebands,respectively,which adopt an off-axis two-mirror reflective structure with an FOV up to 1.2 R⊙,covering the inner coronal edge area and relating to coronal imaging.We present the up-to-date design for the LST payload.
基金Supported by the National Natural Science Foundation of China under Grant Nos 40274050 and 40336052, and the National Key Basic Research Special Foundation of China under Grant No G2000078405.
文摘The characteristics of magnetohydrodynamic fast wave propagation in the solar stratified atmosphere are studied by the ray tracing method. The propagation behaviour of the wavefronts is described in detail. A magnetic field incorporating the characteristics field spreading expected in flux tubes is used, which represents the main feature of an active region. Partly ionization is considered beside the stratified solar atmosphere consisting chromosphere, transition region and corona. The study may explain the characteristics in observations of Moreton and extraultraviolet image telescope （EIT） waves. The wavefront incurred by the disturbance initialized at the base of the transition region propagates fast initially due to strong magnetic field, and it slows down when arriving beyond the region of flux-tube. Meanwhile, the wave propagates in the corona with a more consistent speed, as seen in the observation of EIT waves. The speeds and propagated characteristics in chromosphere and corona of the wavefronts are in agreement with those observed in H~ Moreton and EIT waves, respectively.
