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The Mercury Imaging X-ray Spectrometer is a highly novel instrument that is designed to map Mercury’s elemental composition from orbit at two angular resolutions. By observing the fluorescence X-rays generated when solar-coronal X-rays and charged particles interact with the surface regolith, MIXS will be able to measure the atomic composition of the upper ∼10-20 μm of Mercury’s surface on the day-side. Through precipitating particles on the night-side, MIXS will also determine the dynamic interaction of the planet’s surface with the surrounding space environment. MIXS is composed of two complementary elements: MIXS-C is a collimated instrument which will achieve global coverage at a similar spatial resolution to that achieved (in the northern hemisphere only – i.e. ∼ 50 – 100 km) by MESSENGER; MIXS-T is the first ever X-ray telescope to be sent to another planet and will, during periods of high solar activity (or intense precipitation of charged particles), reveal the X-ray flux from Mercury at better than 10 km resolution. The design, performance, scientific goals and operations plans of the instrument are discussed, including the initial results from commissioning in space.

The purpose of this study was to explore the midterm clinical outcomes of unicompartmental knee replacement (UKR) for medial knee arthropathy through a minimally invasive approach (MIA). From January 2006 to June 2010, 442 consecutive patients (485 knees) were included in the study. All patients underwent MIA-UKR with the mobile bearing Oxford phrase III prosthesis. The incision was made starting 1 cm medial to the medial pole of the patella and extending distally to the tibial tubercle. Radiographic evaluations include femorotibial angle (FTA) from coronal x-rays and rectified varus deformity angle, while clinical evaluations included Knee Society Score (KSS, clinical score and function score), the Western Ontario and McMaster Universities Arthritis Index (WOMAC) osteoarthritis index and visual analog scale (VAS) for pain. Patients followed-up at 1, 3, 6, 12 months after surgery and each year thereafter. Four hundreds and two patients completed the entire follow-up, 40 patients (45 knees) were lost to follow-up. The average follow-up time was 73.0 ± 1.9 months. The mean length of the incisions was 5.0 ± 0.2 cm. The average FTA decreased from 183.6° ± 5.1° preoperatively to 174.3° ± 4.2° postoperatively, and the mean rectified varus deformity angle was 9.3° ± 1.2°. The KSS clinical score improved from 42.4 ± 2.9 to 92.9 ± 3.8, and the function score improved from 53.5 ± 3.8 to 93.5 ± 4.0. The WOMAC score improved from 47.5 ± 3.1 preoperatively to 12.3 ± 1.5 at the last evaluation. The VAS dropped from 7.8 ± 1.9 preoperatively to 1.6 ± 0.2 postoperatively. All clinical evaluations (KSS, WOMAC, VAS) were significantly different (p < 0.05) from pre and post-operative evaluations. The survival rate was 99.1% at 73 months, and the revision rate was 0.9%. The midterm clinical outcomes of MIA-UKR are satisfactory in a Chinese patient population, which is a good surgical option for patients with medial arthropathy of the knee. However, longer-term follow-up studies should be performed in these patients.

Background Adolescent idiopathic scoliosis (AIS) is a complex three-dimensional deformity, and up to now, there has been no literature reporting the analysis of a large sample of X-ray imaging parameters based on artificial intelligence (AI) for it. This study is based on the accurate and rapid measurement of x-ray coronal imaging parameters in AIS patients by AI, to explore the differences and correlations, and to further investigate the risk factors in different groups, so as to provide a theoretical basis for the diagnosis and surgical treatment of AIS. Methods Retrospective analysis of 3192 patients aged 8–18 years who had a full-length orthopantomogram of the spine and were diagnosed with AIS at the First Affiliated Hospital of Zhengzhou University from January 2019 to March 2024. After screened 2092 cases were finally included. The uAI DR scoliosis analysis system with multi-resolution VB-Net convolution network architecture was used to measure CA, CBD, CV, RSH, T1 Tilt, PT, LLD, SS, AVT, and TS parameters. The results were organized and analyzed by using R Studio 4.2.3 software. Results The differences in CA, CBD, CV, RSH, TI tilt, PT, LLD and SS were statistically significant between male and female genders ( p  < 0.05); Differences in CA, CBD, T1 Tilt, PT, SS, AVT and TS were statistically significant in patients with AIS of different severity ( p  < 0.001), and T1 Tilt, AVT, TS were risk factors; Differences in CA, CBD, CV, RSH, T1 Tilt, PT, LLD, SS, AVT and TS were statistically significant ( p  < 0.05) in patients with AIS of different curve types, and TS was a risk factor; Analyzing the correlation between parameters revealed a highly linear correlation between CV and RSH (r = 0.826, p  < 0.001), and a significant linear correlation between CBD and TS, and PT and SS (r = 0.561, p  < 0.001; r = 0.637, p  < 0.001). Conclusion Measurements based on VB-Net neural network found that x-ray coronal imaging parameters varied among AIS patients with different curve types and severities. In clinical practice, it is recommended to consider the discrepancy in parameters to enable a more accurate diagnosis and a personalized treatment plan.

Introduction: dental caries is a public health problem affecting a large percentage of the population. The carious process is highly variable and has periods of progression that alternate with periods of stability of the damaged tissue. There are different techniques to diagnose dental caries, including clinical and radiographic evaluation. Objective: the objective of this study was to establish correlation between the clinical and radiographic caries diagnosis suggested by ICCMSTM, in deciduous and permanent molars of a school population. Methods: descriptive study evaluating a sample for convenience of 1174 proximal and occlusal tooth surfaces of permanent and deciduous molars, taken from the database of 35 outpatients treated at the school of dentistry, who were clinically and radiographically evaluated for caries as recommended by the ICCMSTM based on bitewing x-rays. Results: the clinical and radiographic diagnosis was correlated in 1174 proximal and occlusal surfaces, with 0.41 Spearman’s rank correlation coefficient (p < 0,05). The findings suggest that 95.6% of teeth diagnosed as healthy coincided with the clinical and radiographic results; in early mild stages, there was coincidence in only 8.16% and 6.4% respectively. Conclusions: there is low correlation between the clinical diagnosis of caries and the radiographic examination, in relation to ICCMSTM standards.

It is of great interest and importance to study the variabilities of solar EUV, UV and X-ray irradiance in heliophysics, in Earth’s climate, and space weather applications. A careful study is required to identify, track, monitor and segment the different coronal features such as active regions (ARs), coronal holes (CHs), the background regions (BGs) and the X-ray bright points (XBPs) from spatially resolved full-disk images of the Sun. Variability of solar soft X-ray irradiance is studied for a period of 13 years (February 2007–March 2020, covers Solar Cycle 24), using the X-Ray Telescope on board the Hinode (Hinode/XRT) and GOES (1 – 8 Å). The full-disk X-ray images observed in Al_mesh filter from XRT are used, for the first time , to understand the solar X-ray irradiance variability measured, Sun as a star, by GOES instrument. An algorithm in Python has been developed and applied to identify and segment coronal X-ray features (ARs, CHs, BGs, and XBPs) from the full-disk soft X-ray observations of Hinode/XRT. The segmentation process has been carried out automatically based on the intensity level, morphology and sizes of the X-ray features. The total intensity, area, and contribution of ARs/CHs/BGs/XBPs features were estimated and compared with the full-disk integrated intensity (FDI) and GOES (1 – 8 Å) X-ray irradiance measurements. The XBPs have been identified and counted automatically over the full disk to investigate their relation to solar magnetic cycle. The total intensity of ARs/CHs/BGs/XBPs/FD regions are compared with the GOES (1 – 8 Å) X-ray irradiance variations. We present the results obtained from Hinode/XRT full-disk images (in Al_mesh filter) and compare the resulting integrated full-disk intensity (FDI) with GOES X-ray irradiance. The X-ray intensity measured over ARs/CHs/BGs/XBPs/FD is well correlated with GOES X-ray flux. The contributions of the segmented X-ray features to FDI and X-ray irradiance variations are determined. It is found that the background and active regions have a greater impact on the X-ray irradiance fluctuations. The mean contribution estimated for the whole observed period of the background regions (BGs) will be around 65 ± 10.97 % , whereas the ARs, XBPs and CHs are 30 ± 11.82 % , 4 ± 1.18 % and 1 ± 0.52 % , respectively, to total solar X-ray flux. We observed that the area and contribution of ARs and CHs varies with the phase of the solar cycle, whereas the BGs and XBPs show an anti-correlation. We find that the area of the coronal features is highly variable suggesting that their area has to be taken into account in irradiance models, in addition to their intensity variations. The time series results of XBPs suggest for an existence of anti-correlation between the number of XBPs and the sunspot numbers. It is also important to consider both the number variation and the contribution of XBPs in the reconstruction of total solar X-ray irradiance variability.

Quasi-periodic pulsations (QPPs) are found in solar flares of various magnetic morphologies, e.g. in two-ribbon or circular-ribbon flares, and the mechanisms of their generation are not yet clear. Here we present the first detailed analysis of QPPs (with a period P = 54 ± 13 seconds) found in the Ramaty High Energy Solar Spectroscopic Imager (RHESSI) observations of a relatively rare three-ribbon M1.1 class flare that occurred on 5 July 2012 (SOL2012-07-05T06:49). QPPs are manifested in the temporal profiles of temperature [ T ] and emission measure [ E M ] of “super-hot” ( T s ≈ 30  – 50 MK) plasma but are almost invisible in the profiles of “hot” ( T h ≈ 15  – 20 MK) plasma parameters when approximating X-ray spectra of the flare with the bremsstrahlung spectrum of a two-temperature thermal (Maxwellian) plasma. In addition, QPPs with a similar period are found in the temporal profiles of the flux and spectral index of nonthermal electrons if the observed X-ray spectra are approximated by a combination of the bremsstrahlung spectra of a single-temperature plasma and nonthermal electrons with a power-law energy distribution. QPPs are not well expressed in the X-ray flux according to RHESSI and GOES data, or in radio data. The QPPs are accompanied by apparent systematic movement of a single X-ray source at a low speed of 34 ± 21  km s −1 along the central flare ribbon over a narrow ( < 5  Mm) “tongue” of negative magnetic polarity, elongated ( ≈ 20  Mm) between two areas of positive polarity. The results of magnetic extrapolation in the nonlinear force-free field (NLFFF) approximation show that the X-ray source could move along curved and twisted field lines between two sheared flare arcades. It is worth noting that in the homologous three-ribbon M6.1 flare (SOL2012-07-05T11:39), which occurred in the same region about five hours later, the X-ray sources moved much less systematically and did not produce similar QPPs. We interpret the observed QPPs as a result of successive episodes of energy release in different spatial locations. In each pulsation, ≈(1 – 4) × 10 29  erg is released in the form of thermal energy of hot and super-hot plasmas (or accelerated electrons), which is comparable with the energy of a microflare. The total kinetic energy released during all QPPs is ≈(0.7 – 3.5) × 10 30  erg, which is about an order of magnitude less than the free magnetic energy ≈ 1.56 × 10 31  erg released in the flare region. We discuss possible propagating triggers of the quasi-periodic energy release (slow magnetoacoustic waves, asymmetric rise of curved/twisted field lines, flapping oscillations, and thermal instability in a reconnecting current sheet) and argue that the current state of available mechanisms and observations does not allow us to reach an unambiguous conclusion.

We present the first survey of quiet Sun features observed in hard X-rays (HXRs), using the Nuclear Spectroscopic Telescope ARray (NuSTAR), a HXR focusing optics telescope. The recent solar minimum, combined with NuSTAR’s high sensitivity, has presented a unique opportunity to perform the first HXR imaging spectroscopy on a range of features in the quiet Sun. By studying the HXR emission of these features, we can detect or constrain the presence of high temperature (> 5 MK) or non-thermal sources, to help understand how they relate to larger, more energetic solar phenomena, and determine their contribution to heating the solar atmosphere. We report on several features observed in the 28 September 2018 NuSTAR full-disk quiet Sun mosaics, the first of the NuSTAR quiet Sun observing campaigns, which mostly include steady features of X-ray bright points and an emerging flux region, which later evolved into an active region, as well as a short-lived jet. We find that the features’ HXR spectra are well fitted with isothermal models with temperatures ranging between 2.0 – 3.2 MK. Combining the NuSTAR data with softer X-ray emission from Hinode/XRT and EUV from SDO/AIA, we recover the differential emission measures, confirming little significant emission above 4 MK. The NuSTAR HXR spectra allow us to constrain the possible non-thermal emission that would still be consistent with a null HXR detection. We found that for only one of the features (the jet) was there a potential non-thermal upper limit capable of powering the heating observed. However, even here, the non-thermal electron distribution had to be very steep (effectively mono-energetic) with a low energy cut-off between 3 – 4 keV.

The major SOL2001-08-25 event produced a fast coronal mass ejection (CME: 1430 km s −1 ), strong flare emissions in hard X-rays and γ -rays extending to high energies, and neutrons detected both on spacecraft and by a low-latitude neutron monitor. To supplement the probable picture of this outstanding event, we reconstruct kinematic plots of the eruption and the shock-wave history. The hard X-ray and γ -ray emissions exhibited soft-hard-soft evolution. The emissions were strongest and hardest during a two-minute interval soon after the highest change rate of the magnetic flux within the flare ribbons of 2.6 × 10 19  Mx s −1 , which was simultaneous with the reconstructed acceleration of the erupting flux rope. We reveal an indication of accelerated electrons injected into the erupting flux rope that then precipitated far from the main flare site, producing a hard X-ray source that moved along the footprint of a stretching flux-rope leg. These results suggest that the particle acceleration was governed by magnetic reconnection during the eruption. As in a typical situation, a piston shock was excited early in the impulsive phase and gradually transformed into a bow shock later. The frequency drift of a Type-II burst is shown to be proportional to a power of frequency f , d f / d t ∝ − f ϵ , with a typical range of ϵ being between 5/3 and 2. Overall, the SOL2011-08-25 event was a typical eruptive two-ribbon flare. Its strength was determined mainly by the intensity of the reconnection processes.

The magnetic field changes the radiative output of the Sun and is the main source for all the solar surface features. To study the role of the underlying photospheric magnetic field in relation to emission features observed in the solar corona, we have used the full-disk soft X-ray images from Hinode/X-Ray Telescope ( Hinode/XRT ) and the magnetograms obtained from the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory (SDO) for a period of about 13 years (May 2010 – June 2023), which covers Solar Cycle 24 and the ascending phase of Solar Cycle 25. A sophisticated and established algorithm developed in Python is applied to the X-ray observations from Hinode/XRT to segment the different coronal features by creating segmentation maps of the active regions (ARs), coronal holes (CHs), background regions (BGs), and X-ray bright points (XBPs). Further, these maps have been applied to the full-disk (FD) line-of-sight (LOS) magnetograms from HMI to isolate the X-ray coronal features and photospheric magnetic counterparts, respectively. We computed full-disk and featurewise averages of X-ray intensity and LOS magnetic field (MF) over ARs, CHs, BGs, XBPs, and FD regions. Variations in the quantities resulting from the segmentation, namely the mean intensity, temperature from the filter ratio method, and the unsigned magnetic field of ARs, CHs, BGs, XBPs, and FD regions, are intercompared and compared with the sunspot number (SSN). We find that the X-ray intensity and temperature over ARs, CHs, BGs, XBPs, and FD regions are well correlated with the underlying magnetic field. We discuss the intensity, temperature, and magnetic field variations of the full-disk corona and of all the features. The time series plots of the unsigned magnetic field of the full disk and all the features show magnetic field fluctuations synchronized with the solar cycle (sunspot number). Although the magnetic field of all features varies, the mean, spatially smoothed magnitude of the magnetic field values estimated for the whole observed period of the full disk is around 8.9 ± 2.60 G, active regions (ARs) are around 34.4 ± 18.42 G, whereas BGs, CHs, and XBPs are 7.7 ± 1.72 G, 6.6 ± 1.04 G, and 15.62 ± 8.76 G, respectively. In addition, we find that the mean magnetic field contribution of the background regions (BGs) is around 85 % , whereas ARs, CHs, and XBPs are 11 % , 2 % , and 2 % , respectively, to the average magnetic field of the full disk. The magnetic field time series of all the features suggest that the features show a high variability in their magnetic field and the fluctuations in magnetic field are correlated to fluctuations in intensity and temperature, suggesting that the magnetic field is important in producing different emission features, which are associated with different intensity and temperature values. The magnetic field is responsible for the heating rate of the emission features, which are highly variable on solar cycle timescales. We conclude from the full-disk intensity-temperature-magnetogram analysis that the magnetic field plays a crucial role in driving the different brightenings, emissions, and temperature and heating of the corona at the sites of these magnetic features. In this study, we demonstrate that the segmented coronal features observed in the soft X-ray wavelength can be used as proxies to isolate the corresponding underlying magnetic structures.

The temperature variations of the corona and its individual surface features as a function of the solar cycle are an interesting and important aspect of understanding the physics of the Sun. To study the temperature variations, we have used the full-disk soft X-ray images of the corona obtained from Hinode/X-Ray Telescope (XRT) in different filters. A sophisticated algorithm has been developed in Python to segment the different coronal features such as the active regions (ARs), coronal holes (CHs), background regions (BGs), and X-ray bright points (XBPs), derived the total intensity of all the features, and generated the temperature maps of the corona using the filter ratio method. Due to the XRT straylight issue in some filters and unavailability of a good pair of images, we used for our analysis the filter combinations of Ti-poly and Al-mesh for the period from February 01, 2008 to May 08, 2012 and Al-poly and Al-mesh for the period from May 09, 2012 to June 30, 2021, in total for 14 years which covers Solar Cycle 24. The first analysis in using the XRT intensity values of the coronal features from segmented solar disk and their relation to solar activity is presented. We discuss the temperature variations of a full-disk corona and all features (ARs, CHs, BGs, and XBPs). Our time series plots of the average temperature of the full-disk and all the features show temperature fluctuations synchronized with the solar cycle (sunspot number). Although the temperature of all features varies, but the mean temperature estimated for the whole observed period of the full-disk is around 1.29 ± 0.16 MK and active regions (ARs) are around 1.76 ± 0.32 MK, whereas BGs, CHs, and XBPs are 1.27 ± 0.15 MK, 1.23 ± 0.14 MK, and 1.37 ± 0.18 MK, respectively. In addition, we found that the mean temperature contribution estimated of the background regions (BGs) is around 93.2%, whereas ARs, CHs, and XBPs are 3.1%, 1.6% and 2.1%, respectively, to the average coronal temperature of the full-disk. The temperature values and their variations of all the features suggest that the features show a high variability in their temperature and that the heating rate of the emission features may be highly variable on solar cycle timescales. It is evident from the analysis that the filter-ratio method can be directly used for temperature analysis of coronal features and to study their surface temperature variability as a function of solar magnetic activity.