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Background: Henoch–Sch€onlein purpura nephritis often resolves spontaneously, without treatment, making decisions regarding therapeutic interventions difficult. Methods: Fifty-four patients who were diagnosed as having Henoch–Sch€onlein purpura nephritis between April 2004 and March 2018, and developed hematuria and/or proteinuria, were studied retrospectively. The observation period ended at the disappearance of hematuria or proteinuria, or the last observation date before December 2019 for each patient. Twenty-four of the patients received no treatment (Group A), 19 underwent renin-angiotensinaldosterone system inhibitors only (B), 4 experienced steroid pulse therapy and combination therapy only (C) and the remaining 7 received steroid pulse therapy and combination therapy following renin-angiotensin-aldosterone system inhibitors (C). Clinical characteristics were examined according to the treatment method. Survival analysis for persistent urinary abnormalities was performed according to treatment modality, with multiple treatment records created per subject, if necessary. Results: The highest urine protein/creatinine levels were significantly higher in groups B and C than in group A. The lowest estimated glomerular filtration rate was not significantly different among the three groups. In groups A and B, proteinuria resolved in >90% of patients. Survival analysis showed that steroid pulse therapy and combination therapy was not related to the better resolution of hematuria or proteinuria than renin-angiotensin-aldosterone system inhibitors. Conclusions: Several patients with Henoch–Sch€onlein purpura nephritis went into remission either without treatment or with renin-angiotensin-aldosterone system inhibitors alone. The treatment plan for patients with Henoch– Sch€onlein purpura nephritis needs to be determined carefully. [ABSTRACT FROM AUTHOR]

To create a new flyable detonation propulsion system, a detonation engine system (DES) that can be stowed in sounding rocket S-520-31 has been developed. This paper focused on the first flight demonstration in the space environment of a DES-integrated rotating detonation engine (RDE) using S-520-31. The flight result was compared with ground-test data to validate its performance. In the flight experiment, the stable combustion of the annulus RDE with a plug-shaped inner nozzle was observed by onboard digital and analog cameras. With a time-averaged mass flow of 182±11 g/s and an equivalence ratio of 1.2±0.2, the RDE generated a time-averaged thrust of 518 N and a specific impulse of 290±18 s, which is almost identical to the ideal value of constant pressure combustion. Due to the RDE combustion, the angular velocity increased by 5.7 deg/s in total, and the time-averaged torque from the rotational component of the exhaust during 6 s of operation was 0.26 N·m. The high-frequency sampling data identified the detonation frequency during the recorded time as 20 kHz in the flight, which was confirmed by the DES ground test through high-frequency sampling data analysis and high-speed video imaging. [ABSTRACT FROM AUTHOR]

A detonation engine system is successfully demonstrated for the first time in space using sounding rocket S-520-31 of the Japan Aerospace Exploration Agency/Institute of Space Astronautical Science. Detailed flight results of an S-shaped pulse detonation engine (PDE) installed in the rocket are presented herein. The flight is conducted to confirm that the PDE and its system operate at scheduled sequences in space, confirm the reproducibility of the PDE cycle, and despin the rocket around its axis. It is confirmed that the PDE operated successfully for 14 cycles in space. The experimental plateau pressure of 2.0±0.1 MPa is 80±3% of the calculated plateau pressure, which suggests that detonation occurred in 14 cycles. The pressure profiles of the cycles are similar, and the pressure integrals are 2.0±0.1 kN·s/m2, confirming the excellent reproducibility of the PDE cycle. A probability statistical approach assuming a Gaussian distribution is applied to determine the average angular acceleration difference between processes of the PDE operation, mixture supply, and oxygen supply. The results suggested that the PDE despun the rocket via the thrust produced via detonation combustion, which is consistent with a quasi-steady-state model with an accuracy of 101±15%. [ABSTRACT FROM AUTHOR]

This paper presents the results of an S-shaped pulse detonation engine (PDE) ground firing test in the form of a detonation engine system. The world's first technology demonstration of PDE in space using a sounding rocket is planned, and the aim is to control the rocket spin rate in the axial direction using pulsed detonation. The PDE operation at full sequence was successful. The despin rate change of the rocket between continuous oxygen supply and successful PDE operation is expected to be 0.95 deg/s per run. This change in despin rate can be measured by an onboard gyro sensor, making the system flyable. The test results were compared with data from thrust measurement tests conducted in a laboratory, the results of which confirmed the thrust generation under an ambient pressure of 0.5±0.1 kPa. The average thrust values in the thrust measurement experiments showed good agreement of 101±3% with a quasi-steady-state model introduced to predict the PDE thrust. These results demonstrate the feasibility of the newly developed PDE and its system as the world's first technology demonstration of detonation propulsion in space. [ABSTRACT FROM AUTHOR]