Atomic force microscopy observation of surface morphologies and measurements of local contact potential differences of amorphous solid water samples deposited at 15 and 100 K.

We use an ultra-high vacuum cryogenic atomic force microscope to investigate the surface morphology of amorphous solid water (ASW) prepared by oblique deposition of water vapor onto Si(111)7 × 7 substrates at temperatures of 15 and 100 K. Height-height correlation function analysis of topographic images suggests that ASW at 15 K has a columnar structure and that the typical diameter of the column is 5-10 nm. At 100 K, the typical diameter is 10-30 nm, although columnar features are less prominent. The surface roughness (i.e., deviation of the height) is greater at 15 K than at 100 K, indicating that the surface at 100 K exhibits a relatively flat morphology. This result implies that transient diffusion of deposited water molecules affects the surface morphology at 100 K. In addition, measurements of the local contact potential difference between the tip and the ASW surface suggest that the magnitude of the negative surface potential at the microscopic scale, which is attributed to spontaneous polarisation, cannot simply be scaled by the thickness of ASW as predicted in previous experiments with Kelvin probes.

Analysis of Cation Composition in Dolomites on the Intact Particles Sampled from Asteroid Ryugu.

Characterization of the elemental distribution of samples with rough surfaces has been strongly desired for the analysis of various natural and artificial materials. Particularly for pristine and rare analytes with micrometer sizes embedded on specimen surfaces, non-invasive and matrix effect-free analysis is required without surface polishing treatment. To satisfy these requirements, we proposed a new method employing the sequential combination of two imaging modalities, i.e., microenergy-dispersive X-ray fluorescence (micro-XRF) and Raman micro-spectroscopy. The applicability of the developed method is tested by the quantitative analysis of cation composition in micrometer-sized carbonate grains on the surfaces of intact particles sampled directly from the asteroid Ryugu. The first step of micro-XRF imaging enabled a quick search for the sparsely scattered and micrometer-sized carbonates by the codistributions of Ca2+ and Mn2+ on the Mg2+- and Fe2+-rich phyllosilicate matrix. The following step of Raman micro-spectroscopy probed the carbonate grains and analyzed their cation composition (Ca2+, Mg2+, and Fe2+ + Mn2+) in a matrix effect-free manner via the systematic Raman shifts of the lattice modes. The carbonates were basically assigned to ferroan dolomite bearing a considerable amount of Fe2+ + Mn2+ at around 10 atom %. These results are in good accordance with the assignments reported by scanning electron microscopy-energy-dispersive X-ray spectroscopy, where the thin-sectioned and surface-polished Ryugu particles were applicable. The proposed method requires neither sectioning nor surface polishing; hence, it can be applied to the remote sensing apparatus on spacecrafts and planetary rovers. Furthermore, the non-invasive and matrix effect-free characterization will provide a reliable analytical tool for quantitative analysis of the elemental distribution on the samples with surface roughness and chemical heterogeneity at a micrometer scale, such as art paintings, traditional crafts with decorated shapes, as well as sands and rocks with complex morphologies in nature.

The influence of some rare earth elements as neutron absorbers on the inception of Oklo natural nuclear reactors.

A totally reflected core model was built to estimate the infinite multiplication factor ${{k}}_{{\infty}}$ as a parametric function using MCNP code. Thus, it was possible to evaluate the influence of a specific physical parameter on the criticality occurrence of the Oklo phenomenon, namely initial Poisons (IP: Gd, Sm and Nd). In fact, these rare earth elements, prior to criticality occurrence in Oklo reaction zones (RZs), are considered as a key parameter in the present study. Thus, it was possible to construct isocritical lines, ${{k}}_{{\infty}}\left({{V}}_{{UO}{2}},{{\varPhi}}_{{C}}\ \right)\cong{1}$, over a significant range of Uraninite volume fraction: ${{V}}_{{UO}{2}}\left[\%\right]{\in}\left[{0};{40}\right]$. The corresponding critical porosity ${{\varPhi}}_{{C}}$ is obtained for a given value of ${{V}}_{{UO}{2}}$ by Python-driven MCNP5 calculations. By including realistic measurements of IP for different RZs, it was possible to distinguish the corresponding inception circumstances for the natural RZs considered here.

Evidence of fast neutron operating in Oklo.

Since the discovery of the first reactor zone (RZ) at the Oklo uranium deposit in 1972, many isotopic studies have been performed to understand the mechanism of the operation as fission reactors and to trace the migration behaviors of fissiogenic isotopes produced in the Oklo RZs. As the representative parameters to characterize the operating conditions of RZs, neutron fluence generated in RZ, duration of RZ operation, restitution factor of 235U from α decay of 239Pu produced by neutron capture of 238U and the proportion of fission events due to 235U, 238U and 239Pu are compiled and compared with individual RZs. In particular, one of the Oklo RZs, RZ 13, shows several specific features in the view point of isotopic and nuclear characteristics. By comparison of the data between RZ13 and other RZs, fission contribution of 238U for RZ13 is found to be significantly higher than those of other RZs.

Water circulation in Ryugu asteroid affected the distribution of nucleosynthetic isotope anomalies in returned sample.

Studies of material returned from Cb asteroid Ryugu have revealed considerable mineralogical and chemical heterogeneity, stemming primarily from brecciation and aqueous alteration. Isotopic anomalies could have also been affected by delivery of exogenous clasts and aqueous mobilization of soluble elements. Here, we show that isotopic anomalies for mildly soluble Cr are highly variable in Ryugu and CI chondrites, whereas those of Ti are relatively uniform. This variation in Cr isotope ratios is most likely due to physicochemical fractionation between 54Cr-rich presolar nanoparticles and Cr-bearing secondary minerals at the millimeter-scale in the bulk samples, likely due to extensive aqueous alteration in their parent bodies that occurred [Formula: see text] after Solar System birth. In contrast, Ti isotopes were marginally affected by this process. Our results show that isotopic heterogeneities in asteroids are not all nebular or accretionary in nature but can also reflect element redistribution by water.

Identification of Risk Factors for Mortality and Prolonged Hospitalization in Patients Treated With Surgical Drainage for Otogenic Intracranial Complications: A Nationwide Study Using a Japanese Inpatient Database.

OBJECTIVE: Data on risk factors for otogenic intracranial complications including cerebral abscess have been limited. Using a nationwide database, the aim was to identify the factors related to mortality and delayed discharge. STUDY DESIGN: Retrospective. SETTING: Nationwide database using the Diagnostic Procedure Combination database. MAIN OUTCOME MEASURES: Data of 145 patients were extracted from a Japanese inpatient database between 2012 and 2020. The main outcome was survival at discharge. In a subgroup analysis of the 137 surviving patients, the second outcome was delayed discharge. RESULTS: The mortality rate was 5.5% (8 of 145). Logistic regression analyses identified intracerebral complications (adjusted odds ratio [OR], 3.09) and more than 2-day delay of the first surgery after admission (adjusted OR, 4.68) as risk factors for mortality. Specifically, consciousness level evaluated by the Japan Coma Scale (JCS) was significantly related to prolonged hospitalization or mortality: JCS I (adjusted OR, 3.40) and JCS ≥II (adjusted OR, 25.1). CONCLUSIONS: Although otogenic intracranial complications are rare, and their mortality is decreasing because of the progress in imaging and clinical strategies, they remain the most severe complications of suppurative otitis media and/or cholesteatoma. Consciousness level at admission, comorbid diabetes mellitus, and a greater than 2-day delay of surgical intervention were related to prolonged hospitalization or mortality.

Abundant presolar grains and primordial organics preserved in carbon-rich exogenous clasts in asteroid Ryugu.

Preliminary analyses of asteroid Ryugu samples show kinship to aqueously altered CI (Ivuna-type) chondrites, suggesting similar origins. We report identification of C-rich, particularly primitive clasts in Ryugu samples that contain preserved presolar silicate grains and exceptional abundances of presolar SiC and isotopically anomalous organic matter. The high presolar silicate abundance (104 ppm) indicates that the clast escaped extensive alteration. The 5 to 10 times higher abundances of presolar SiC (~235 ppm), N-rich organic matter, organics with N isotopic anomalies (1.2%), and organics with C isotopic anomalies (0.2%) in the primitive clasts compared to bulk Ryugu suggest that the clasts formed in a unique part of the protoplanetary disk enriched in presolar materials. These clasts likely represent previously unsampled outer solar system material that accreted onto Ryugu after aqueous alteration ceased, consistent with Ryugu's rubble pile origin.

A systematic mechanistic survey on the reactions between OH radical and CH3OH on ice.

A systematic mechanistic survey was performed for the CH3OH + OH reaction on ice. ONIOM(ωB97X-D/Def2-TZVP:AMOEBA09) calculations suggested a range of binding energies for the CH2OH radical (0.29-0.69 eV) and CH3OH (0.15-0.72 eV) molecule on hexagonal water ice (Ih) and amorphous solid water (ASW). Computed average binding energies of CH2OH radical (0.49 eV) and CH3OH (0.41 eV) are relatively stronger compared to the CH3O radical binding energies (0.32 eV, Sameera et al., J. Phy. Chem. A, 2021, 125, 387-393). Thus, the CH3OH molecule, CH2OH and CH3O radicals can adsorb on ice, where the binding energies follow the order CH2OH > CH3OH > CH3O. The multi-component artificial force-induced reaction (MC-AFIR) method systematically determined the reaction mechanisms for the CH3OH + OH reaction on ice, where two reaction paths, giving rise to CH2OH and CH3O radicals, were confirmed. A range of reaction barriers, employing the ωB97X-D/Def2-TZVP level of theory, was found for each reaction (0.03-0.11 eV for CH2OH radical formation, and 0.03-0.44 eV for CH3O radical formation). Based on the lowest energy reaction paths, we suspect that both reactions operate on ice. The computed data in this study evidence that the nature of the binding site or the reaction site has a significant effect on the computed binding energies or reaction barriers. Thus, the outcomes of the present study will be very useful for the computational astrochemistry community to determine reliable binding energies and reaction barriers on ice.

Samples returned from the asteroid Ryugu are similar to Ivuna-type carbonaceous meteorites.

Carbonaceous meteorites are thought to be fragments of C-type (carbonaceous) asteroids. Samples of the C-type asteroid (162173) Ryugu were retrieved by the Hayabusa2 spacecraft. We measured the mineralogy and bulk chemical and isotopic compositions of Ryugu samples. The samples are mainly composed of materials similar to those of carbonaceous chondrite meteorites, particularly the CI (Ivuna-type) group. The samples consist predominantly of minerals formed in aqueous fluid on a parent planetesimal. The primary minerals were altered by fluids at a temperature of 37° ± 10°C, about [Formula: see text] million (statistical) or [Formula: see text] million (systematic) years after the formation of the first solids in the Solar System. After aqueous alteration, the Ryugu samples were likely never heated above ~100°C. The samples have a chemical composition that more closely resembles that of the Sun's photosphere than other natural samples do.

Clinical practice guidelines for the diagnosis and management of otitis media with effusion (OME) in children in Japan - 2022 update.

This is an update of the 2015 Guidelines developed by the Japan Otological Society and Oto-Rhino-Laryngeal Society of Japan defining otitis media with effusion (OME) in children (younger than 12 years old) and describing the disease rate, diagnosis, and method of examination. Recommended therapies that received consensus from the guideline committee were updated in consideration of current therapies used in Japan and based on available evidence. METHOD: Regarding the treatment of OME in children, we developed Clinical Questions (CQs) and retrieved documents on each theme, including the definition, disease state, method of diagnosis, and medical treatment. In the previous guidelines, no retrieval expression was used to designate a period of time for literature retrieval. Conversely, a literature search of publications from March 2014 to May 2019 has been added to the JOS 2015 Guidelines. For publication of the CQs, we developed and assigned strengths to recommendations based on the collected evidence. RESULTS: OME in children was classified into one group lacking the risk of developing chronic or intractable disease and another group at higher risk (e.g., children with Down syndrome, cleft palate), and recommendations for clinical management, including follow-up, is provided. Information regarding management of children with unilateral OME and intractable cases complicated by adhesive otitis media is also provided. CONCLUSION: In clinical management of OME in children, the Japanese Clinical Practice Guidelines recommends management not only of complications of OME itself, such as effusion in the middle ear and pathologic changes in the tympanic membrane, but also pathologic changes in surrounding organs associated with infectious or inflammatory diseases.

Oxygen isotopes of anhydrous primary minerals show kinship between asteroid Ryugu and comet 81P/Wild2.

The extraterrestrial materials returned from asteroid (162173) Ryugu consist predominantly of low-temperature aqueously formed secondary minerals and are chemically and mineralogically similar to CI (Ivuna-type) carbonaceous chondrites. Here, we show that high-temperature anhydrous primary minerals in Ryugu and CI chondrites exhibit a bimodal distribution of oxygen isotopic compositions: 16O-rich (associated with refractory inclusions) and 16O-poor (associated with chondrules). Both the 16O-rich and 16O-poor minerals probably formed in the inner solar protoplanetary disk and were subsequently transported outward. The abundance ratios of the 16O-rich to 16O-poor minerals in Ryugu and CI chondrites are higher than in other carbonaceous chondrite groups but are similar to that of comet 81P/Wild2, suggesting that Ryugu and CI chondrites accreted in the outer Solar System closer to the accretion region of comets.

Ryugu's nucleosynthetic heritage from the outskirts of the Solar System.

Little is known about the origin of the spectral diversity of asteroids and what it says about conditions in the protoplanetary disk. Here, we show that samples returned from Cb-type asteroid Ryugu have Fe isotopic anomalies indistinguishable from Ivuna-type (CI) chondrites, which are distinct from all other carbonaceous chondrites. Iron isotopes, therefore, demonstrate that Ryugu and CI chondrites formed in a reservoir that was different from the source regions of other carbonaceous asteroids. Growth and migration of the giant planets destabilized nearby planetesimals and ejected some inward to be implanted into the Main Belt. In this framework, most carbonaceous chondrites may have originated from regions around the birthplaces of Jupiter and Saturn, while the distinct isotopic composition of CI chondrites and Ryugu may reflect their formation further away in the disk, owing their presence in the inner Solar System to excitation by Uranus and Neptune.

Pharmacotherapy focusing on for the management of otitis media with effusion in children: Systematic review and meta-analysis.

OBJECTIVE: To examine the evidence for treating children with otitis media with effusion with pharmacotherapy. DATA SOURCES: For the systematic review, data were retrieved from PubMed, Cochrane database, and the Japan Medical Abstracts Society Database (1st January 1995 through 31th May 2019). STUDY SELECTION: Articles addressing pharmacotherapy for the management of otitis media with effusion in children were selected in English. DATA EXTRACTION: The database was searched using the keywords "Otitis Media with effusion or secretory otitis media" and the following medical agents: carbocysteine, antihistamines, leukotriene receptor antagonist, and steroid nasal spray. DATA SYNTHESIS: After a critical review of 18 studies, studies addressing steroid nasal spray were eligible for quantitative synthesis. Intranasal steroids for OME showed no benefit with OR 1.155 (95% CI 0.834-1.598) within one month. Conversely, intranasal steroids have effects for OME with OR 1.858 (95% CI 1.240-2.786) for more than one month. CONCLUSIONS: We found evidence of benefit from treatment of OME in children with intranasal steroids and S-carboxymethylcysteine at longer-term follow-up.

UV-Induced Formation of Ice XI Observed Using an Ultra-High Vacuum Cryogenic Transmission Electron Microscope and its Implications for Planetary Science.

The occurrence of hydrogen atom-ordered form of ice Ih, ice XI, in the outer Solar System has been discussed based on laboratory experiments because its ferroelectricity influences the physical processes in the outer Solar System. However, the formation of ice XI in that region is still unknown due to a lack of formation conditions at temperatures higher than 72 K and the effect of UV-rays on the phase transition from ice I to ice XI. As a result, we observed the UV-irradiation process on ice Ih and ice Ic using a newly developed ultra-high vacuum cryogenic transmission electron microscope. We found that ice Ih transformed to ice XI at temperatures between 75 and 140 K with a relatively small UV dose. Although ice Ic partially transformed to ice XI at 83 K, the rate of transformation was slower than for ice Ih. These findings point to the formation of ice XI at temperatures greater than 72 K via UV irradiation of ice I crystals in the Solar System; icy grains and the surfaces of icy satellites in the Jovian and Saturnian regions.

Identification of risk factors for mortality and delayed oral dietary intake in patients with open drainage due to deep neck infections: Nationwide study using a Japanese inpatient database.

BACKGROUNDS: Data on risk factors for deep neck infection including descending necrotizing mediastinitis (DNM) have been limited. Using a nationwide database, the aim was identifying the factors related to patient death and delay in recovering oral intake. METHODS: Data of 4949 patients were extracted from a Japanese inpatient database between 2012 and 2017. The main outcome was survival at discharge. In a subgroup analysis of the 4949 patients with survival, the second outcome was delay in the interval between admission and full recovery of oral intake. RESULTS: Only a few factors (advanced-age, ventilation) were associated with both mortality and delayed oral dietary intake by logistic regression analyses. Conversely, several factors including DNM (adjusted-odds ratio [OR] 1.41) and repeated surgery (adjusted-OR 1.70) were significantly related only to delayed oral dietary intake. CONCLUSIONS: Although DNM was not necessarily related to mortality, patients with DNM should receive careful attention to avoid delayed oral dietary intake.

Delivery of Electrons by Proton-Hole Transfer in Ice at 10 K: Role of Surface OH Radicals.

Although water ice has been widely accepted to carry a positive charge via the transfer of excess protons through a hydrogen-bonded system, ice was recently found to be a negative charge conductor upon simultaneous exposure to electrons and ultraviolet photons at temperatures below 50 K. In this work, the mechanism of electron delivery was confirmed experimentally by both measuring currents through ice and monitoring photodissociated OH radicals on ice by using a novel method. The surface OH radicals significantly decrease upon the appearance of negative current flow, indicating that the electrons are delivered by proton-hole (OH-) transfer in ice triggered by OH- production on the surface. The mechanism of proton-hole transfer was rationalized by density functional theory calculations.

CH3O Radical Binding on Hexagonal Water Ice and Amorphous Solid Water.

Binding energies of the CH3O radical on hexagonal water ice (Ih) and amorphous solid water (ASW) were calculated using the ONIOM(QM:MM) method. A range of binding energies is found (0.10-0.50 eV), and the average binding energy is 0.32 eV. The CH3O radical binding on the ASW surfaces is stronger than on the Ih surfaces. The computed binding energies from the ONIOM(wB97X-D/def2-TZVP:AMBER) and wB97X-D/def2-TZVP methods agree quite well. Therefore, the ONIOM(QM:MM) method is expected to give accurate binding energies at a low computational cost. Binding energies from the ONIOM(wB97X-D/def2-TZVP:AMBER) and ONIOM(wB97X-D/def2-TZVP:AMOEBA09) methods differ noticeably, indicating that the choice of force field matters. According to the energy decomposition analysis, the electrostatic interactions and Pauli repulsions between the CH3O radical and ice play a crucial role in the binding energy. This study gives quantitative insights into the CH3O radical binding on interstellar ices.

Systematic Review of Surgical Outcomes Following Repair of Patulous Eustachian Tube.

OBJECTIVE: To perform a systematic review and meta-analysis of surgical outcomes following repair of patulous Eustachian tube (PET). DATA SOURCES: Analysis of cases collected from studies published between January 1990 and December 2018 and identified using PubMed, Google Scholar, and Cochrane databases. STUDY SELECTION: Articles addressing interventions to treat PET were selected. DATA EXTRACTION: The database was searched using the keywords "patulous Eustachian tube treatment" and yielded 1,370 studies. Twenty studies were eligible for inclusion. DATA SYNTHESIS: A total of 914 cases were evaluated for surgical approach, patient outcomes, and complications. The reported techniques were categorized by the procedure type, including ventilation tube insertion, mass loading of the tympanic membrane, ET injection, plug surgery, shim surgery, tuboplasty, and ET closure. Overall PET symptom improvement were reported for ventilation tube insertion (79 cases, mean: 58%, 95% CI: 47-69%), mass loading of the tympanic membrane (43 cases, mean: 50%, 95% CI: 32-69%), ET injection (139 cases, mean: 47%, 95% CI: 38-56%), plug surgery (386 cases, mean: 81%, 95% CI: 77-85%), shim surgery (122 cases, mean: 62%, 95% CI: 53-70%), tuboplasty (105 cases, mean: 41%, 95% CI: 31-51%), and ET closure (40 cases, mean: 66%, 95% CI: 49-80%). A low incidence of minor complications was reported. CONCLUSIONS: This systematic review describes clinical outcome data following surgical management of PET. Plug surgery and shim surgery show relatively high effectiveness and safety. Further prospective studies that compare surgical approaches for PET are needed.

Location of the stapedius muscle with reference to the facial nerve in patients with unilateral congenital aural atresia: implication for active middle ear implants surgery.

Background: Detailed investigations of the stapedial muscle (SM) in congenital aural atresia (CAA) patients have yet to be adequately conducted.Objectives: To assess image variations in the mastoid segment of the facial nerve (FN) and SM in CAA.Materials and methods: A total of nine patients comprising of 9 ears with unilateral CAA were studied. The courses of the FN and SM were evaluated from the basic point to 1 mm intervals between the mastoid portion of FN, and measured from the mean X and Y values in each group.Results: The atresia side of FN among the Y values showed significant differences compared to the contralateral side. In terms of the SM, there were no significant differences in both the X and Y values. The stapedial muscle of the CAA patients was located medially to the FN. Conversely, the distance from the PSC to the FN revealed no significant differences with regard to the X and Y values for each group.Conclusion: The current observations revealed that the SM is located more posterior to the FN in CAA patients, and this is mainly attributed to the laterally and anteriorly displaced FN.