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1.
Mod Rheumatol ; 33(1): 96-103, 2023 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-35234889

RESUMEN

OBJECTIVES: Romosozumab is a newly released and widely known molecular-targeted drug for severe osteoporosis treatment with comparable effectiveness to denosumab. However, there have been no reports discussing the efficacy of those treatments for rheumatoid arthritis (RA) patients, especially those receiving glucocorticoids. This retrospective observational registry study compared the efficacy of 12-month treatment of denosumab and romosozumab in RA patients under the influence of glucocorticoid intake. METHODS: Following propensity score matching, 36 patients each in the denosumab and romosozumab groups were analysed in this study. Drug effectiveness was evaluated by measuring bone mineral density (BMD) at the lumbar spine, total hip, and femoral neck at baseline, 6 and 12 months as well as alterations in P1NP, TRACP-5b, and simplified disease activity index (SDAI). The occurrence of adverse events and new fractures was also assessed. RESULTS: At 12 months of treatment, BMD at the lumbar spine was increased by 7.5% in the denosumab group and 8.7% in the romosozumab group, which were both significantly and comparably elevated over baseline. At the total hip and femoral neck, romosozumab tended to exhibit favourable efficacy to increase BMD versus denosumab. Both P1NP and TRACP-5b were significantly lower in the denosumab group as compared with the baseline. Conversely in the romosozumab group, P1NP was increased over baseline, while TRACP-5b was decreased. Regarding SDAI alterations, both the romosozumab and denosumab groups exhibited comparable improvements in RA disease activity over time during treatment. Recorded adverse events and new fractures during treatment were few and minor in both groups. CONCLUSIONS: Romosozumab exhibited comparable efficacy to denosumab for increasing BMD even under the influence of glucocorticoids for treating RA. Both drugs may be therefore suitable for managing osteoporosis in patients with RA and glucocorticoid intake.


Asunto(s)
Artritis Reumatoide , Conservadores de la Densidad Ósea , Fracturas Óseas , Osteoporosis , Humanos , Denosumab/efectos adversos , Glucocorticoides/farmacología , Glucocorticoides/uso terapéutico , Estudios Retrospectivos , Fosfatasa Ácida Tartratorresistente , Osteoporosis/diagnóstico por imagen , Osteoporosis/tratamiento farmacológico , Osteoporosis/inducido químicamente , Densidad Ósea , Conservadores de la Densidad Ósea/farmacología , Conservadores de la Densidad Ósea/uso terapéutico , Fracturas Óseas/epidemiología , Artritis Reumatoide/diagnóstico por imagen , Artritis Reumatoide/tratamiento farmacológico
2.
Earth Planets Space ; 74(1): 146, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36185784

RESUMEN

Millimetre-sized primordial rock fragments originating from asteroid Ryugu were investigated using high energy X-ray fluorescence spectroscopy, providing 2D and 3D elemental distribution and quantitative composition information on the microscopic level. Samples were collected in two phases from two sites on asteroid Ryugu and safely returned to Earth by JAXA's asteroid explorer Hayabusa2, during which time the collected material was stored and maintained free from terrestrial influences, including exposure to Earth's atmosphere. Several grains of interest were identified and further characterised to obtain quantitative information on the rare earth element (REE) content within said grains, following a reference-based and computed-tomography-assisted fundamental parameters quantification approach. Several orders of magnitude REE enrichments compared to the mean CI chondrite composition were found within grains that could be identified as apatite phase. Small enrichment of LREE was found for dolomite grains and slight enrichment or depletion for the general matrices within the Ryugu rock fragments A0055 and C0076, respectively. Supplementary Information: The online version contains supplementary material available at 10.1186/s40623-022-01705-3.

3.
Proc Jpn Acad Ser B Phys Biol Sci ; 98(6): 227-282, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35691845

RESUMEN

Presented here are the observations and interpretations from a comprehensive analysis of 16 representative particles returned from the C-type asteroid Ryugu by the Hayabusa2 mission. On average Ryugu particles consist of 50% phyllosilicate matrix, 41% porosity and 9% minor phases, including organic matter. The abundances of 70 elements from the particles are in close agreement with those of CI chondrites. Bulk Ryugu particles show higher δ18O, Δ17O, and ε54Cr values than CI chondrites. As such, Ryugu sampled the most primitive and least-thermally processed protosolar nebula reservoirs. Such a finding is consistent with multi-scale H-C-N isotopic compositions that are compatible with an origin for Ryugu organic matter within both the protosolar nebula and the interstellar medium. The analytical data obtained here, suggests that complex soluble organic matter formed during aqueous alteration on the Ryugu progenitor planetesimal (several 10's of km), <2.6 Myr after CAI formation. Subsequently, the Ryugu progenitor planetesimal was fragmented and evolved into the current asteroid Ryugu through sublimation.


Asunto(s)
Meteoroides , Sistema Solar , Agua
5.
Masui ; 65(8): 828-831, 2016 Sep.
Artículo en Japonés | MEDLINE | ID: mdl-30351596

RESUMEN

It is known that a portion of an epidural catheter can remain embedded when the catheter is pulled back at the time of insertion or a longer length than required is used. We report a case in which an epi- dural catheter piece including a metal coil broke off and remained embedded at the time of withdrawal. Because of the presence of the coil, MRI could not be utilized, while CT scanning was useful to locate the remaining portion. Following surgical extraction, the embedded portion was thoroughly examined. The point of the catheter was cut sharply, which suggested that damage occurred without awareness of the anesthesi- ologist When a catheter breaks leaving a remnant surgical extraction should be considered based on appropriate examination findings.


Asunto(s)
Cateterismo/instrumentación , Agujas/efectos adversos , Adulto , Anestesia Epidural/métodos , Femenino , Humanos , Microscopía Electroquímica de Rastreo
6.
Sci Rep ; 14(1): 11557, 2024 05 21.
Artículo en Inglés | MEDLINE | ID: mdl-38773352

RESUMEN

Juvenile loneliness is a risk factor for psychopathology in later life. Deprivation of early social experience due to peer rejection has a detrimental impact on emotional and cognitive brain function in adulthood. Accumulating evidence indicates that soy peptides have many positive effects on higher brain function in rodents and humans. However, the effects of soy peptide use on juvenile social isolation are unknown. Here, we demonstrated that soy peptides reduced the deterioration of behavioral and cellular functions resulting from juvenile socially-isolated rearing. We found that prolonged social isolation post-weaning in male C57BL/6J mice resulted in higher aggression and impulsivity and fear memory deficits at 7 weeks of age, and that these behavioral abnormalities, except impulsivity, were mitigated by ingestion of soy peptides. Furthermore, we found that daily intake of soy peptides caused upregulation of postsynaptic density 95 in the medial prefrontal cortex and phosphorylation of the cyclic adenosine monophosphate response element binding protein in the hippocampus of socially isolated mice, increased phosphorylation of the adenosine monophosphate-activated protein kinase in the hippocampus, and altered the microbiota composition. These results suggest that soy peptides have protective effects against juvenile social isolation-induced behavioral deficits via synaptic maturation and cellular functionalization.


Asunto(s)
Agresión , Suplementos Dietéticos , Miedo , Hipocampo , Ratones Endogámicos C57BL , Aislamiento Social , Animales , Aislamiento Social/psicología , Masculino , Miedo/efectos de los fármacos , Agresión/efectos de los fármacos , Ratones , Hipocampo/metabolismo , Hipocampo/efectos de los fármacos , Proteínas de Soja/farmacología , Memoria/efectos de los fármacos , Conducta Animal/efectos de los fármacos , Corteza Prefrontal/efectos de los fármacos , Corteza Prefrontal/metabolismo , Homólogo 4 de la Proteína Discs Large/metabolismo , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo
7.
Auris Nasus Larynx ; 51(3): 443-449, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38520975

RESUMEN

OBJECTIVE: Olfactory and gustatory functions are important sensory aspects in humans. Although they are believed to influence each other, their interrelationship is not well understood. In this study, we aimed to investigate the relationship between the olfactory and gustatory functions based on the results of a large-scale epidemiological study (Iwaki Health Promotion Project) of the general local population. METHODS: We analyzed 565 participants who underwent taste and olfactory tests in the 2019 Iwaki Project. Gustatory function was tested for four taste qualities (sweet, sour, salty, and bitter) using whole-mouth taste tests. Olfactory function was tested using the University of Pennsylvania Smell Identification Test modified for Japanese (UPSIT-J). We evaluated sex-related differences between olfactory and gustatory functions and the effects of various factors on olfactory identification using multivariate analysis. Furthermore, we compared the percentage of accurate UPSIT-J responses between the normal and hypogeusia groups. We also analyzed the effects of taste and olfactory functions on eating. RESULTS: Olfactory and gustatory functions were lower in men than in women. Among the four taste qualities, salty taste was the most closely associated with olfactory identification ability, with lower olfactory scores of salty taste in the hypogeusia group than in the normal group. Moreover, the hyposmia group had higher daily salt intake than the normal olfaction group in women. CONCLUSION: These results suggest that olfactory identification tests may be useful in predicting elevated salt cognitive thresholds, leading to a reduction in salt intake, which may contribute to hypertension prevention.


Asunto(s)
Promoción de la Salud , Humanos , Masculino , Femenino , Persona de Mediana Edad , Adulto , Japón/epidemiología , Anciano , Factores Sexuales , Olfato/fisiología , Gusto/fisiología , Ageusia/fisiopatología , Ageusia/epidemiología , Trastornos del Olfato/epidemiología , Anosmia/fisiopatología , Percepción del Gusto/fisiología
8.
Nat Commun ; 15(1): 8075, 2024 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-39277576

RESUMEN

Ryugu is the C-type asteroid from which material was brought to Earth by the Hayabusa2 mission. A number of individual grains and fine-grained samples analysed so far for noble gases have indicated that solar wind and planetary (known as P1) noble gases are present in Ryugu samples with concentrations higher than those observed in CIs, suggesting the former to be more primitive compared to the latter. Here we present results of analyses of three fine-grained samples from Ryugu, in one of which Xe concentration is an order of magnitude higher than determined so far in other samples from Ryugu. Isotopically, this Xe resembles P1, but with a much stronger isotopic fractionation relative to solar wind and significantly lower 36Ar/132Xe ratio than in P1. This previously unknown primordial noble gas component (here termed P7) provides clues to constrain how the solar composition was fractionated to form the planetary components.

9.
Nat Commun ; 15(1): 5708, 2024 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-38987536

RESUMEN

We report primordial aqueous alteration signatures in water-soluble organic molecules from the carbonaceous asteroid (162173) Ryugu by the Hayabusa2 spacecraft of JAXA. Newly identified low-molecular-weight hydroxy acids (HO-R-COOH) and dicarboxylic acids (HOOC-R-COOH), such as glycolic acid, lactic acid, glyceric acid, oxalic acid, and succinic acid, are predominant in samples from the two touchdown locations at Ryugu. The quantitative and qualitative profiles for the hydrophilic molecules between the two sampling locations shows similar trends within the order of ppb (parts per billion) to ppm (parts per million). A wide variety of structural isomers, including α- and ß-hydroxy acids, are observed among the hydrophilic molecules. We also identify pyruvic acid and dihydroxy and tricarboxylic acids, which are biochemically important intermediates relevant to molecular evolution, such as the primordial TCA (tricarboxylic acid) cycle. Here, we find evidence that the asteroid Ryugu samples underwent substantial aqueous alteration, as revealed by the presence of malonic acid during keto-enol tautomerism in the dicarboxylic acid profile. The comprehensive data suggest the presence of a series for water-soluble organic molecules in the regolith of Ryugu and evidence of signatures in coevolutionary aqueous alteration between water and organics in this carbonaceous asteroid.

10.
Nat Commun ; 15(1): 6809, 2024 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-39237539

RESUMEN

Returned samples from the carbonaceous asteroid (162173) Ryugu provide pristine information on the original aqueous alteration history of the Solar System. Secondary precipitates, such as carbonates and phyllosilicates, reveal elemental partitioning of the major component ions linked to the primordial brine composition of the asteroid. Here, we report on the elemental partitioning and Mg isotopic composition (25Mg/24Mg) of breunnerite [(Mg, Fe, Mn)CO3] from the Ryugu C0002 sample and the A0106 and C0107 aggregates by sequential leaching extraction of salts, exchangeable ions, carbonates, and silicates. Breunnerite was the sample most enriched in light Mg isotopes, and the 25Mg/24Mg value of the fluid had shifted lower by ~0.38‰ than the initial value (set to 0‰) before dolomite precipitation. As a simple model, the Mg2+ first precipitated in phyllosilicates, followed by dolomite precipitation, at which time ~76-87% of Mg2+ had been removed from the primordial brine. A minor amount of phyllosilicate precipitation continued after dolomite precipitation. The element composition profiles of the latest solution that interacted with the cation exchange pool of Ryugu were predominantly Na-rich. Na+ acts as a bulk electrolyte and contributes to the stabilization of the negative surface charge of phyllosilicates and organic matter on Ryugu.

11.
Sci Adv ; 10(3): eadi7203, 2024 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-38241366

RESUMEN

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.

12.
Nat Commun ; 15(1): 3493, 2024 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-38684653

RESUMEN

Extraterrestrial minerals on the surface of airless Solar System bodies undergo gradual alteration processes known as space weathering over long periods of time. The signatures of space weathering help us understand the phenomena occurring in the Solar System. However, meteorites rarely retain the signatures, making it impossible to study the space weathering processes precisely. Here, we examine samples retrieved from the asteroid Ryugu by the Hayabusa2 spacecraft and discover the presence of nonmagnetic framboids through electron holography measurements that can visualize magnetic flux. Magnetite particles, which normally provide a record of the nebular magnetic field, have lost their magnetic properties by reduction via a high-velocity (>5 km s-1) impact of a micrometeoroid with a diameter ranging from 2 to 20 µm after destruction of the parent body of Ryugu. Around these particles, thousands of metallic-iron nanoparticles with a vortex magnetic domain structure, which could have recorded a magnetic field in the impact event, are found. Through measuring the remanent magnetization of the iron nanoparticles, future studies are expected to elucidate the nature of the nebular/interplanetary magnetic fields after the termination of aqueous alteration in an asteroid.

13.
Nat Commun ; 15(1): 7488, 2024 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-39209830

RESUMEN

Primordial carbon delivered to the early earth by asteroids and meteorites provided a diverse source of extraterrestrial organics from pre-existing simple organic compounds, complex solar-irradiated macromolecules, and macromolecules from extended hydrothermal processing. Surface regolith collected by the Hayabusa2 spacecraft from the carbon-rich asteroid 162173 Ryugu present a unique opportunity to untangle the sources and processing history of carbonaceous matter. Here we show carbonaceous grains in Ryugu can be classified into three main populations defined by spectral shape: Highly aromatic (HA), Alkyl-Aromatic (AA), and IOM-like (IL). These carbon populations may be related to primordial chemistry, since C and N isotopic compositions vary between the three groups. Diffuse carbon is occasionally dominated by molecular carbonate preferentially associated with coarse-grained phyllosilicate minerals. Compared to related carbonaceous meteorites, the greater diversity of organic functional chemistry in Ryugu indicate the pristine condition of these asteroid samples.

14.
Medicine (Baltimore) ; 102(8): e33128, 2023 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-36827001

RESUMEN

RATIONALE: Basal cell carcinoma (BCC) arising in the umbilicus is relatively rare, and in particular, there have been few reports mentioning peritumoral sweat gland structures histopathologically. We herein, report 2 cases of umbilical BCC with sweat gland structures within and around the tumor. PATIENT CONCERNS: A 61-year-old woman had a 2-year history of black exudative plaque in her umbilicus, and an 80-year-old woman had a 6-month history of dark brownish plaque in the umbilicus, with exudation 2 months prior to her first visit. DIAGNOSES: Based on the histopathological finding, both cases were confirmed as BCC. The results of immunohistochemical staining showed that the tumor cells were Ber-EP4 positive. In addition, EMA-positive glandular structures were seen within and around the tumor. INTERVENTIONS: Curative resection at the level of the linea alba on the bottom side was performed. OUTCOMES: No relapse has been observed since resection in either patient. LESSONS: We herein report 2 cases of umbilical BCC with sweat glands and ducts. Although whether peri- and/or intra-tumor sweat gland structures are the source of the tumor or arise by transdifferentiation from tumor cells remains unclear, these findings may provide clues to help understand the morphopathogenesis of umbilical BCC in the future.


Asunto(s)
Carcinoma Basocelular , Neoplasias Cutáneas , Humanos , Femenino , Persona de Mediana Edad , Anciano de 80 o más Años , Neoplasias Cutáneas/patología , Ombligo/patología , Recurrencia Local de Neoplasia/patología , Carcinoma Basocelular/patología , Glándulas Sudoríparas/patología
15.
Case Rep Dermatol ; 15(1): 126-132, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37899945

RESUMEN

Linear IgA disease (LAD) is a rare autoimmune bullous disease characterized by IgA deposition in the basement membrane zone (BMZ). A 66-year-old male was treated for myelodysplastic syndrome at our hospital for 5 years, during which his condition remained stable. He visited our department because of erythema with itching, which appeared 1 year ago and gradually exacerbated with the development of blisters and erosions. During the first visit, multiple erythemas with erosions and crusts on their periphery were observed on the trunk and lower limbs. Histopathological examination revealed subepidermal blisters with inflammatory cell infiltration, mainly constituting of neutrophils, eosinophils, and lymphocytes. Direct and indirect immunofluorescence showed linear IgA deposits in the BMZ and IgA anti-BMZ antibodies, respectively, while immunoblotting using a concentrated culture supernatant of HaCaT cells detected IgA antibodies reactive to 120-kDa LAD-1. Accordingly, the patient was diagnosed with lamina lucida-type LAD. Subsequent colonoscopy revealed multiple colorectal polyps and rectal adenocarcinoma (Tis, N0, and M0). Multigene panel test showed an ATM variant of unknown significance but did not detect any pathogenic variants associated with intestinal polyposis syndrome. The skin lesions quickly resolved with oral diaphenylsulfone 50 mg/day and resection of the colorectal polyps and adenocarcinoma. To our knowledge, this is the first reported case of LAD associated with multiple colorectal polyps and rectal adenocarcinoma. Additionally, we also analyzed reported cases of LAD associated with malignancy from the literature.

16.
Nat Commun ; 14(1): 1482, 2023 Mar 17.
Artículo en Inglés | MEDLINE | ID: mdl-36932072

RESUMEN

All life on Earth contains amino acids and carbonaceous chondrite meteorites have been suggested as their source at the origin of life on Earth. While many meteoritic amino acids are considered indigenous, deciphering the extent of terrestrial contamination remains an issue. The Ryugu asteroid fragments (JAXA Hayabusa2 mission), represent the most uncontaminated primitive extraterrestrial material available. Here, the concentrations of amino acids from two particles from different touchdown sites (TD1 and TD2) are reported. The concentrations show that N,N-dimethylglycine (DMG) is the most abundant amino acid in the TD1 particle, but below detection limit in the other. The TD1 particle mineral components indicate it experienced more aqueous alteration. Furthermore, the relationships between the amino acids and the geochemistry suggest that DMG formed on the Ryugu progenitor body during aqueous alteration. The findings highlight the importance of aqueous chemistry for defining the ultimate concentrations of amino acids in primitive extraterrestrial samples.

17.
Nat Commun ; 14(1): 6525, 2023 Oct 16.
Artículo en Inglés | MEDLINE | ID: mdl-37845217

RESUMEN

The sample from the near-Earth carbonaceous asteroid (162173) Ryugu is analyzed in the context of carbonaceous meteorites soluble organic matter. The analysis of soluble molecules of samples collected by the Hayabusa2 spacecraft shines light on an extremely high molecular diversity on the C-type asteroid. Sequential solvent extracts of increasing polarity of Ryugu samples are analyzed using mass spectrometry with complementary ionization methods and structural information confirmed by nuclear magnetic resonance spectroscopy. Here we show a continuum in the molecular size and polarity, and no organomagnesium molecules are detected, reflecting a low temperature and water-rich environment on the parent body approving earlier mineralogical and chemical data. High abundance of sulfidic and nitrogen rich compounds as well as high abundance of ammonium ions confirm the water processing. Polycyclic aromatic hydrocarbons are also detected in a structural continuum of carbon saturations and oxidations, implying multiple origins of the observed organic complexity, thus involving generic processes such as earlier carbonization and serpentinization with successive low temperature aqueous alteration.

18.
Nat Commun ; 14(1): 532, 2023 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-36797235

RESUMEN

Chondrule-like objects and Ca-Al-rich inclusions (CAIs) are discovered in the retuned samples from asteroid Ryugu. Here we report results of oxygen isotope, mineralogical, and compositional analysis of the chondrule-like objects and CAIs. Three chondrule-like objects dominated by Mg-rich olivine are 16O-rich and -poor with Δ17O (=δ17O - 0.52 × Î´18O) values of ~ -23‰ and ~ -3‰, resembling what has been proposed as early generations of chondrules. The 16O-rich objects are likely to be melted amoeboid olivine aggregates that escaped from incorporation into 16O-poor chondrule precursor dust. Two CAIs composed of refractory minerals are 16O-rich with Δ17O of ~ -23‰ and possibly as old as the oldest CAIs. The discovered objects (<30 µm) are as small as those from comets, suggesting radial transport favoring smaller objects from the inner solar nebula to the formation location of the Ryugu original parent body, which is farther from the Sun and scarce in chondrules. The transported objects may have been mostly destroyed during aqueous alteration in the Ryugu parent body.

19.
Nat Commun ; 14(1): 1292, 2023 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-36944653

RESUMEN

The pristine sample from the near-Earth carbonaceous asteroid (162173) Ryugu collected by the Hayabusa2 spacecraft enabled us to analyze the pristine extraterrestrial material without uncontrolled exposure to the Earth's atmosphere and biosphere. The initial analysis team for the soluble organic matter reported the detection of wide variety of organic molecules including racemic amino acids in the Ryugu samples. Here we report the detection of uracil, one of the four nucleobases in ribonucleic acid, in aqueous extracts from Ryugu samples. In addition, nicotinic acid (niacin, a B3 vitamer), its derivatives, and imidazoles were detected in search for nitrogen heterocyclic molecules. The observed difference in the concentration of uracil between A0106 and C0107 may be related to the possible differences in the degree of alteration induced by energetic particles such as ultraviolet photons and cosmic rays. The present study strongly suggests that such molecules of prebiotic interest commonly formed in carbonaceous asteroids including Ryugu and were delivered to the early Earth.

20.
Sci Rep ; 13(1): 14096, 2023 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-37644091

RESUMEN

In the samples collected from the asteroid Ryugu, magnetite displays natural remanent magnetization due to nebular magnetic field, whereas contemporaneously grown iron sulfide does not display stable remanent magnetization. To clarify this counterintuitive feature, we observed their nanoscale magnetic domain structures using electron holography and found that framboidal magnetites have an external magnetic field of 300 A m-1, similar to the bulk value, and its magnetic stability was enhanced by interactions with neighboring magnetites, permitting a disk magnetic field to be recorded. Micrometer-sized pyrrhotite showed a multidomain magnetic structure that was unable to retain natural remanent magnetization over a long time due to short relaxation time of magnetic-domain-wall movement, whereas submicron-sized sulfides formed a nonmagnetic phase. These results show that both magnetite and sulfide could have formed simultaneously during the aqueous alteration in the parent body of the asteroid Ryugu.

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