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This article presents a new method for accurately estimating the height and zonal drift velocity of ionospheric irregularities, based on crossed signal paths from two BeiDou geostationary satellites to two ground-based receivers. The ratio of distances between different signal paths varies with altitude, and irregularities’ height can be identified according to observed arrival times of ionospheric irregularities among signal paths. The proposed method is an improvement of the conventional way with an assumed fixed height of about 350 km for the nocturnal ionospheric irregularities. We present two cases with estimated irregularities heights of 284 and 403 km, respectively. Accordingly, the calculated zonal drift velocities and the apex height of the irregularities are significantly different as well. Observations from the nearby Hainan Coherent Scatter Phased Array Radar (HCOPAR) radar validate the estimated height and velocity, though discrepancies existing in terms of the arrival times of ionospheric irregularities observed by the two kinds of instruments. It further highlights the necessity of this method to probe global navigation satellite system (GNSS)-sensitive irregularities using the disturbed GNSS signals per se.

Stable fixation is crucial in fracture treatment. Currently, optimal fracture fixation devices with osteoinductivity, mechanical compatibility, and corrosion resistance are urgently needed for clinical practice. Niobium (Nb), whose mechanical properties are similar to those of bone tissue, has excellent biocompatibility and corrosion resistance, so it has the potential to be the most appropriate fixation material for internal fracture treatment. However, not much attention has been paid to the use of Nb in the area of clinical implants. Yet its role and mechanism of promoting fracture healing remain unclear. Hence, this study aims at elucidating on the effectiveness of Nb by systematically evaluating its osteogenic performance via in vivoand ex vivo tests.

Purpose: The blood vessel gives key information for pathological changes in a variety of diseases. In view of the crucial role of blood vessel structure, the present study aims to establish a digital human blood vessel standard model for diagnosing blood vessel-related diseases. Methods: The present study recruited eight healthy volunteers, and reconstructed their bilateral upper extremity arteries according to CTA. The reconstructed vessels were segmented, registered, and merged into a bunch. After being cut by continuous cut planes, the dispersion of the blood vessel bunches on each cut plane were calculated. Results: The results demonstrated that the middle segment of the brachial artery, the proximal segment of the ulnar artery, and the middle and distal segments of the radial artery had a low degree of dispersion. A standard blood vessel model was finally established by the integral method using the low-dispersion segments above. The accuracy of the standard blood vessel model was also verified by an actual contralateral vessel, which revealed that the deviation between the model and the actual normal contralateral brachial artery was relatively small. Conclusion: The structure of the model was highly accordant with the real ones, which can be of great help in evaluating the blood vessel changes in blood vessel-related diseases, bone and soft-tissue tumors, and creating accurate surgical plans.

The abundant observations and research established a detailed category of the terrestrial ionospheric irregularities, which significantly advanced our understanding of how the Earth system's complicated physical and chemical process generates the intermediate‐scale structures of the charged particles. Motivated by a future attempt at categorizing the Martian ionospheric irregularity, this study designs a method for naive classification of the plasma density depletion, enhancement, and oscillation based on the in situ measurements of the Martian ionosphere. The technique consists of several procedures: trend estimation, detrending and candidate extraction, and parameterization. The classification is achieved through a machine‐learning‐like process using some testing artificial density profiles. A preliminary credence test shows a good performance in separating the terrestrial low‐latitude Equatorial Plasma bubble (depletion) and mid‐latitude Median‐scale Traveling Ionospheric Disturbance (oscillation). Another detection experiment of the Martian plasma depletion events (collected by Basuvaraj et al. (2022a, https://doi.org/10.1029/2022je007302)) showed a recall rate (i.e., true positive) of 38% but with a high precision of 67.8%. Therefore, we believe the proposed method could convincingly extract different Martian ionospheric irregularities and help uncover the climatological characteristics in the future. Ionospheric irregularities refer to the inhomogeneous distribution of the charged particles in the ionosphere, which would affect radio wave transmission and thus pose threats to tremendous human‐made assets deployed in terrestrial outer space and on other planets such as Mars. Unlike the terrestrial ionospheric irregularities, whose categories and physical mechanisms are well‐understood, the Martian counterparts are still in poor understanding. Previous studies have indicated the diversity, but the category has yet to be built. The large data set provided by the Mars Atmosphere and Volatile EvolutioN (MAVEN) mission allows a more detailed investigation of the Martian ionospheric irregularities. Therefore, an automatic method to extract the ionospheric density enhancement, depletion, and oscillation would be a first step to figuring out the exact types of the Martian ionospheric irregularities, thus helping to extend our knowledge of how the finer ionospheric structures are formed backgrounded by the region crustal magnetic field other than the global dipole field. A modified rolling‐barrel algorithm extracts the candidate irregularitiesClassification of the candidates into depletion, enhancement, and oscillation is achieved through a few parameterization processesInitial testing shows good performance on the Martian and terrestrial ionospheric irregularities A modified rolling‐barrel algorithm extracts the candidate irregularities Classification of the candidates into depletion, enhancement, and oscillation is achieved through a few parameterization processes Initial testing shows good performance on the Martian and terrestrial ionospheric irregularities