Microstructural and chemical features of impact melts on Ryugu particle surfaces: Records of interplanetary dust hit on asteroid Ryugu.

The Hayabusa2 spacecraft delivered samples of the carbonaceous asteroid Ryugu to Earth. Some of the sample particles show evidence of micrometeoroid impacts, which occurred on the asteroid surface. Among those, particles A0067 and A0094 have flat surfaces on which a large number of microcraters and impact melt splashes are observed. Two impact melt splashes and one microcrater were analyzed to unveil the nature of the objects that impacted the asteroid surface. The melt splashes consist mainly of Mg-Fe-rich glassy silicates and Fe-Ni sulfides. The microcrater trapped an impact melt consisting mainly of Mg-Fe-rich glassy silicate, Fe-Ni sulfides, and minor silica-rich glass. These impact melts show a single compositional trend indicating mixing of Ryugu surface materials and impactors having chondritic chemical compositions. The relict impactor in one of the melt splashes shows mineralogical similarity with anhydrous chondritic interplanetary dust particles having a probable cometary origin. The chondritic micrometeoroids probably impacted the Ryugu surface during its residence in a near-Earth orbit.

Oxidation-induced nanolite crystallization triggered the 2021 eruption of Fukutoku-Oka-no-Ba, Japan.

Nanometer-sized crystals (nanolites) play an important role in controlling eruptions by affecting the viscosity of magmas and inducing bubble nucleation. We present detailed microscopic and nanoscopic petrographic analyses of nanolite-bearing and nanolite-free pumice from the 2021 eruption of Fukutoku-Oka-no-Ba, Japan. The nanolite mineral assemblage includes biotite, which is absent from the phenocryst mineral assemblage, and magnetite and clinopyroxene, which are observed as phenocrysts. The boundary between the nanolite-bearing brown glass and nanolite-free colorless glass is either sharp or gradational, and the sharp boundaries also appear sharp under the transmitted electron microscope. X-ray absorption fine structure (XAFS) analysis of the volcanic glass revealed that the nanolite-free colorless glass records an oxygen fugacity of QFM + 0.98 (log units), whereas the nanolite-bearing brown glass records a higher apparent oxygen fugacity (~ QFM + 2). Thermodynamic modelling using MELTS indicates that higher oxygen fugacities increase the liquidus temperature and thus induced the crystallization of magnetite nanolites. The hydrous nanolite mineral assemblage and glass oxygen fugacity estimates suggest that an oxidizing fluid supplied by a hot mafic magma induced nanolite crystallization in the magma reservoir, before the magma fragmentation. The oxidation-induced nanolite crystallization then enhanced heterogeneous bubble nucleation, resulting in convection in the magma reservoir and triggering the eruption.

A dehydrated space-weathered skin cloaking the hydrated interior of Ryugu.

Without a protective atmosphere, space-exposed surfaces of airless Solar System bodies gradually experience an alteration in composition, structure and optical properties through a collective process called space weathering. The return of samples from near-Earth asteroid (162173) Ryugu by Hayabusa2 provides the first opportunity for laboratory study of space-weathering signatures on the most abundant type of inner solar system body: a C-type asteroid, composed of materials largely unchanged since the formation of the Solar System. Weathered Ryugu grains show areas of surface amorphization and partial melting of phyllosilicates, in which reduction from Fe3+ to Fe2+ and dehydration developed. Space weathering probably contributed to dehydration by dehydroxylation of Ryugu surface phyllosilicates that had already lost interlayer water molecules and to weakening of the 2.7 µm hydroxyl (-OH) band in reflectance spectra. For C-type asteroids in general, this indicates that a weak 2.7 µm band can signify space-weathering-induced surface dehydration, rather than bulk volatile loss.

Impact of glucagon like peptide-1 receptor agonist and sodium glucose cotransporter 2 inhibitors on type 2 diabetes patients with renal impairment.

INTRODUCTION: Diabetes mellitus is a progressive disease with cardiovascular complications. We evaluated the impact of a glucagon like peptide-1 (GLP-1) receptor agonist and sodium glucose cotransporter 2 (SGLT-2) inhibitors dapagliflozin and empagliflozin on renal and cardiac function in type 2 diabetes patients with renal impairment. MATERIALS AND METHODS: A total of 156 patients referred with suboptimal glycemic control were assigned to Group G (GLP-1): n = 72 or Group S (SGLT-2 inhibitor)-dapagliflozin (n = 52) or empagliflozin (n = 32). Renal function was assessed every 3 months for 36 months. Cardiovascular parameters were evaluated every 12 months for 36 months. RESULTS: Compared with baseline, HbA1c and systolic blood pressure significantly decreased in both groups (p < 0.05). The estimated glomerular filtration rate decreased, but without significance. Albuminuria decreased significantly in both groups and then subsequently increased after 30 months in Group S. Diastolic cardiac function, assessed by E/e' or left atrial volume index, decreased only in Group G at 36 months. CONCLUSIONS: The GLP-1 receptor agonist and SGLT-2 inhibitors were effective for glycemic and blood pressure control and for maintaining renal function. The GLP-1 receptor agonist improved diastolic function at 36 months.

Quality of Life and Emotional Distress in Peritoneal Dialysis and Hemodialysis Patients.

Cardiovascular disease-associated morbidity and mortality are reportedly higher in hemodialysis (HD) patients compared with peritoneal dialysis (PD) patients. However, few studies have estimated changes in state of depression and cognitive impairment in patients undergoing HD and PD. The present study evaluated the impact of HD or PD on patients' quality of life (QoL), cognitive impairment, and depression status over 2 years. This 24-month observational, prospective study included 45 HD and 30 PD patients. Patients were assessed before and every 12 months after starting dialysis for 24 months. Measurements included QoL (36-Item Short-Form Health Survey [SF-36]), cognitive impairment (Mini-Mental State Examination [MMSE]), depressive state (Center for Epidemiologic Studies Depression Scale [CES-D]), grip strength, and 24-h urine volume (UV). Physical and social component scores of the SF-36 significantly improved in PD patients at 24 months compared with those observed at baseline (42.8 vs. 39.4; P < 0.05 and 46.4 vs. 37.3; P < 0.05, respectively); however, scores remained unchanged in HD patients. MMSE scores were significantly decreased at 12 and 24 months in HD patients (29.0 vs. 26.0, 25.0; P < 0.05), but remained unchanged in PD patients. Moreover, CES-D scores significantly worsened at 24 months in HD patients (12.8 vs. 16.5), but remained unchanged in PD. Preservation of UV and grip strength was associated with SF-36, CES-D, and MMSE scores. Our findings indicate that PD is associated with higher QoL and recovery from cognitive failure compared with HD.