Reconstruction of past atmospheric CH4 concentration from the firn air data at Dome Fuji (scientific note)

Air samples were collected from different depths of the firn layer at Dome Fuji in December 1998 and analyzed for CH4 concentrations. The age distribution of CH4 in the firn was calculated by using a one-dimensional numerical model, and then the inverse method was applied to reconstruct variations of atmospheric CH4 in the past. The age distribution function was calculated by including processes of molecular diffusion, downward air advection and bubble trapping in the snow-ice transition zone. Once the age distribution function is calculated, the vertical distribution of CH4 in the firn layer can be reconstructed by a linear combination of the age distribution functions weighted by the atmospheric CH4 concentrations in the past. Therefore, the most plausible past atmospheric record of CH4 can be derived iteratively so that its observed profile in the firn layer was reproduced well. In order to check the calculation scheme, the estimated variation of atmospheric CH4 was compared with direct measurements in the Antarctic region. They were in good agreement with each other, even for rapid slowing down of the secular increase observed in the 1990\u27s

Reconstruction of the atmospheric CO2 concentration history from an Antarctic deep ice core, Dome Fuji using a wet extraction technique: analysis procedures,dating of air in ice and concentration variations (scientific paper)

In order to deduce the atmospheric CO2 concentration variations over the past 320 kyr, air samples were extracted from the Dome Fuji deep ice core using a wet extraction method, and their CO2 concentration values were determined with a reproducibility of 1.0 ppmv. By measuring the CO2 concentrations of firn air samples collected at Dome Fuji, it was found that the effective bubble close-off depth can be defined by the mid-point of the close-off zone. For dating the air in the ice core, the age difference between ice and air (Δage) was estimated by using a densification model to be between 1000 and 5000 years, showing small and large values during the interglacial and glacial periods, respectively, due primarily to variations of precipitation. The CO2 concentration variations with a mean time resolution of about 1.1 kyr over the last three glacial-interglacial cycles showed a good correlation with those of δ18O, which suggests that the Southern Ocean played an important role in the variation of the atmospheric CO2 concentration during the last three glacial-interglacial cycles

In-situ measurement of the atmospheric CO concentration at Syowa Station, Antarctica

A high-precision measurement system for the atmospheric CO concentration was developed. With some modifications to a gas chromatograph CO analyzer, instrumental reproducibility of 0.5 ppbv was achieved. This could be sufficient for detection of short-term, seasonal and long-term variations of the atmospheric CO concentration in the Antarctic region. A standard gas system to maintain a consistent calibration scale for the CO measurements was also prepared. The measurement system was installed at Syowa Station in March 2000 and has been maintained up to the present. The first-year\u27s observation showed a clear seasonal cycle of CO concentration

Single‐Crystal‐to‐Single‐Crystal Installation of Ln₄(OH)₄ Cubanes in an Anionic Metallosupramolecular Framework

Postsynthetic installation of lanthanide cubanes into a metallosupramolecular framework via a single-crystal-to-single-crystal (SCSC) transformation is presented. Soaking single crystals of K6[Rh4Zn4O(l-cys)12] (K6[1]; l-H2cys=l-cysteine) in a water/ethanol solution containing Ln(OAc)3 (Ln3+=lanthanide ion) results in the exchange of K+ by Ln3+ with retention of the single crystallinity, producing Ln2[1] (2Ln) and Ln0.33[Ln4(OH)4(OAc)3(H2O)7][1] (3Ln) for early and late lanthanides, respectively. While the Ln3+ ions in 2Ln exist as disordered aqua species, those in 3Ln form ordered hydroxide-bridged cubane clusters that connect [1]6− anions in a 3D metal-organic framework through coordination bonds with carboxylate groups. This study shows the utility of an anionic metallosupramolecular framework with carboxylate groups for the creation of a series of metal cubanes that have great potential for various applications, such as magnetic materials and heterogeneous catalysts.This is the pre-peer reviewed version of the following article: N. Yoshinari, N. Meundaeng, H. Tabe, Y. Yamada, S. Yamashita, Y. Nakazawa, T. Konno, Angewandte Chemie. 2020, 132, 18204., which has been published in final form at https://doi.org/10.1002/ange.202008296.This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving

Direct measurement of magnetocaloric effect (MCE) in frustrated Gd-based molecular complexes

The version of record of this article, first published in Journal of Thermal Analysis and Calorimetry, is available online at Publisher’s website: https://doi.org/10.1007/s10973-024-13344-9.Generation of low temperatures below 1 K has been required for applications and fundamental research, given this, development of new materials utilized for demagnetization cooling has extensively been performed in recent years. Here, we studied two polynuclear Gd3+-based molecular compounds of Gd0.33[Gd4(OH)4(OAc)3][Rh4Zn4(L-cys)12]·32H2O (1Gd) and Gd0.33[Gd4(OH)4(OAc)3][Ir4Zn4(L-cys)12]·28H2O (2Gd) (L-cys = L-cysteinate) which show paramagnetic even at low temperatures due to their frustrated arrangement of Gd3+ ions. We discuss the magnitude of the magnetocaloric effect (MCE) in them inferred from the isothermal magnetic entropy change (ΔSM) from isothermal magnetization data. The − ΔSMmax of 1Gd and 2Gd are 15.15 J kg−1 K−1 and 17.49 J kg−1 K−1 occur at 2.0 K under an applied field from 0 to 7 T, respectively. We also discussed the results of heat capacity measurement under magnetic fields to confirm the validity of the entropy change for 1Gd. Furthermore, with an aim of detecting their MCE directly, we have developed a new non-magnetic and metal-free magnetocaloric measurement cell. The adiabatic temperature change (ΔTad) occurs in a small amount of sample on an order of 102-microgram with the application and removal of various magnitude magnetic fields starting from several initial temperatures were detected directly, to evaluate the potential of them to be a refrigerant for an adiabatic demagnetization refrigerator. The instrumental design for direct measurements of MCE is described along with the construction details

Distribution and Sequence of Pyknotic Cells in Rat Fetuses Exposed to Busulfan

Busulfan, an antineoplastic bifunctional-alkylating agent, is known to induce developmental anomalies. In the present study, we examined the distribution and sequence of pyknotic cells in rat fetal tissues exposed to busulfan. Pregnant rats on gestation day 13 were administered intraperitoneally 30 mg/kg of busulfan, and fetal tissues were examined at 6, 12, 24, 36, 48, 72 and 96 hours after treatment (HAT). Pyknosis of component cells was observed markedly in the brain, moderately in the eyes and spinal cord and mildly in the craniofacial tissue, mandible, limb buds, tail bud, ganglions, alimentary tract, lungs, kidneys, pancreas and liver. In the brain, mitotic inhibition was also detected. Most of the pyknotic cells were considered to be apoptotic cells judging from the results of TUNEL staining and electron microscopic examination. Commonly in the above-mentioned tissues, pyknotic cells began to increase at 24 HAT, peaked at 36 or 48 HAT and disappeared at 96 HAT, which is when the histological picture returned to normal in most tissues except for the brain, spinal cord and eyes. The present study clarified the outline of busulfan-induced apoptosis in rat fetuses

Bipolar localization of putative photoreceptor protein for phototaxis in thermophilic cyanobacterium Synechococcus elongatus

Funding Information: This work was supported in part by Grants-in-Aid for scientific research from the Ministry of Education, Science, Sports and Culture, Japan (no. 11640653 to K.M.).We identified an open reading frame from a database of the entire genome of Synechococcus elongatus, the product of which was very similar to pixJ1, which was proposed as photoreceptor gene for phototaxis in Synechocystis sp. PCC6803 [Yoshihara et al. (2000) Plant Cell Physiol. 41: 1299]. The mRNA of S. elongatus pixJ (SepixJ) was expressed in vivo as a part of the product of an operon. SePixJ was detected exclusively in the membrane fraction after cell fractionation. Immunogold labeling of SePixJ in ultra-thin sections indicated that it existed only in both ends of the rod-shaped cell; probably bound with the cytoplasmic membrane.publishersversionPeer reviewe

心不全を合併した心房細動患者のカテーテルアブレーション後の長期予後 : 左室駆出率に基づいた心不全のサブタイプ間における比較

Aims: Heart failure (HF) prognosis has been reported similar in patients with preserved vs. reduced left ventricular ejection fraction (LVEF). This study compared the long-term prognosis of HF patients undergoing radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF). Methods and results: Among 5010 patients undergoing RFCA in Kansai Plus AF registry, 656 patients (13.1%) with a documented history of HF were enrolled in the study before RFCA. The primary endpoint was a composite of all-cause death, HF hospitalization, and stroke or systemic embolism. Patients with reduced (<40%), mid-range (40-49%), and preserved (≥50%) LVEF were 98 (14.9%), 107 (16.3%), and 451 (68.8%) patients, respectively. The prevalence of ischaemic heart disease and cardiomyopathies was higher among patients with reduced as compared with preserved LVEF (27.6% vs. 10.0%, P < 0.05 and 36.7% vs. 15.3%, P < 0.05, respectively). The median follow-up period was 2.9 years. The 3-year cumulative risk for the primary endpoint was higher in patients with reduced LVEF (32.7%) compared to those with mid-range (11.7%) or preserved (11.6%) LVEF (P < 0.001). Reduced LVEF was the most significant independent risk factor for primary endpoint (hazard ratio, 2.83; 95% confidence interval 1.74-4.61, P < 0.001). The 3-year arrhythmia recurrence rate was similar among the groups (48.2%, 42.8%, and 47.3%, respectively, P = 0.75). Conclusion : This study raises hypothesis that patients with HFrEF and AF had approximately three times higher risk for a composite of all-cause death, HF hospitalization, and stroke or systemic embolism after AF ablation compared with patients with HFmrEF or HFpEF.博士（医学）・甲第802号・令和3年12月21日Copyright: © Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2021.This is a pre-copyedited, author-produced version of an article accepted for publication in Europace following peer review. The version of record "Europace Online ahead of print (2021 Aug 31;euab201) is available online at: https://doi.org/10.1093/europace/euab201.発行元が定める登録猶予期間終了の後、本文を登録予定（2022.08