267 research outputs found

    The Surface of Electrolyte Solutions is Stratified

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    The distribution of ions at the air/water interface plays a decisive role in many natural processes. It is generally understood that polarizable ions with low charge density are surface-active, implying they sit on top of the water surface. Here, we revise this established hypothesis by combining surface-specific heterodyne-detected vibrational sum-frequency generation with neural network-assisted ab initio molecular dynamics simulations. Our results directly demonstrate that ions in typical electrolyte solutions are, in fact, located in a subsurface region leading to a stratification of such interfaces into two distinctive water layers. The outermost surface is ion-depleted, and the sub-surface layer is ion-enriched. As a result, an effective liquid/liquid interface buried a few {\AA} inside the solution emerges, creating a second water/electrolyte interface, in addition to the outermost air/water interface

    Leukemia autopsies in Japan

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    For the purpose to know whether the annual increase of leukemia incidence in Japan is due to some leukemogenic factors or due to the increased detection rate, the authors made some statistical survey of autopsy cases in which the diagnosis is reliable and not any type of leukemias escape the detection. The results showed that acute leukemias, which are found mostly in younger age, is actually increasing. In addition, it has been deduced that among the suspected factors the increase in ionizing radiation will be one of the most probable factors for the increase in leukemia incidence</p

    Necessity for Reassessment of Patients with Serogroup 2 Hepatitis C Virus (HCV) and Undetectable Serum HCV RNA

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    We encountered a patient positive for anti-hepatitis C virus (HCV) whose serum HCV RNA was undetectable with the Roche AmpliPrep/Cobas TaqMan HCV assay (CAP/CTM) version 1 but showed a high viral load with the Abbott RealTime HCV assay (ART). Discrepancies in the detectability of serum HCV RNA were investigated among 891 consecutive patients who were positive for anti-HCV. Specific nucleotide variations causing the undetectability of HCV RNA were determined and confirmed by synthesizing RNA coding those variations. Serum samples with the discrepancies were also reassessed by CAP/CTM version 2. Among the 891 anti-HCV-positive patients, 4 patients had serum HCV RNA levels that were undetectable by CAP/CTM version 1 despite having levels of > 5 log IU/ml that were detected by ART. All four patients had HCV genotype 2a and high titers of anti-HCV. Sequencing of the HCV 5' noncoding regions revealed 2 common variations, A at nucleotide (nt) 145 and T at nt 151. Synthesized RNAs of the HCV 5' noncoding region with standard (NCR145G151C) and variant nucleotides at nt 145 and nt 151 were quantified with CAP/CTM. RNAs of NCR145G151C and NCR145G151T were quantifiable with CAP/CTM version 1, while those of NCR145A151T and NCR145A151C went undetected. The substitution from G to A at nt 145 specifically conferred this undetectability, while this undetectability was reverted in synthesized HCV RNA with correction of this variation. Reassessment of these samples by CAP/CTM version 2 resulted in similar levels of HCV RNA being detected by ART. We conclude that HCV patients with undetectable HCV RNA by CAP/CTM version 1 should be reassessed for viral quantification

    Bilateral verses bilateral with tri-segmental endoscopic drainage using metal stents for high-grade malignant hilar biliary obstructions: A multicenter, randomized controlled trial: BRAVE study (BRAVE study)

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    Introduction: Bilateral endoscopic drainage with self-expanding metallic stent (SEMS) can be used to manage hilar malignant biliary obstruction (HMBO) more effectively in comparison to unilateral drainage. An increased drainage area is predicted to prolong stent patency and patient survival. However, few reports have described the utility of trisegmental drainage and the benefits of using trisegmental drainage remain unknown. Thus, we launched a randomized clinical trial (RCT) to compare the clinical outcomes between bilateral and trisegmental drainage using SEMSs in patients with high-grade HMBO. Methods and analysis: This study was conducted as a multicenter randomized control trial (RCT) in 8 high-volume medical centers in Japan, and will prove the non-inferiority of bilateral drainage to trisegmental drainage. Patients with unresectable HMBO with Bismuth type IIIa or IV who pass the inclusion and exclusion criteria will be randomized to receive bilateral or trisegmental drainage at a 1:1 ratio. At each center, the on-site study investigators will obtain informed consent from the candidates, and will use an electronic data capture system (REDCap) to input necessary information, and register candidates with the registration secretariat. The primary endpoint is the rate of non-recurrent biliary obstruction (RBO) at 180 days after SEMSs placement. A -10% non-inferiority margin is assumed in the statistical analysis of the primary endpoint. Secondary endpoints include the rate of technical and clinical success, time to recurrent biliary obstruction (TRBO), causes of RBO, procedure-related adverse events (AEs), procedure time, TRBO with or without endoscopic sphincterotomy, overall survival, and the technical and clinical success rates at reintervention. Discussion: If the non-inferiority of bilateral drainage is demonstrated, it is predicted that the procedure time will be shortened and the medical cost will be reduced, which will be beneficial to the patient and the medical economy

    Directed induction of alveolar type I cells derived from pluripotent stem cells via Wnt signaling inhibition

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    iPS細胞を用いて肺胞上皮細胞の分化評価に成功 --肺の障害研究への足がかりに--. 京都大学プレスリリース. 2020-12-14.Alveologenesis is a developmental step involving the expansion of the lung surface area which is essential for gas exchange. The gas exchange process is mediated by alveolar type I (AT1) cells, which are known to be differentiated from alveolar type II (AT2) or bipotent cells. Due to the difficulty of isolating and culturing primary AT1 cells, the mechanism underlying their differentiation is not completely understood. We performed single‐cell RNA sequencing (scRNA‐seq) of fibroblast‐dependent alveolar organoids (FD‐AOs), including human induced pluripotent stem cell (hiPSC)‐derived epithelial cells and fetal lung fibroblasts, and identified hiPSC‐derived AT1 (iAT1) cells. A comparison of the FD‐AOs and fibroblast‐free alveolar organoids showed that iAT1 cells were mainly present in the FD‐AOs. Importantly, the transcriptomes of iAT1 cells were remarkably similar to those of primary AT1 cells. Additionally, XAV‐939, a tankyrase inhibitor, increased iAT1 cells in passaged FD‐AOs, suggesting that these cells were differentiated from hiPSC‐derived AT2 (iAT2) cells through the inhibition of canonical Wnt signaling. Consequently, our scRNA‐seq data allowed us to define iAT1 cells and identify FD‐AOs as a useful model for investigating the mechanism underlying human AT1 cell differentiation from AT2 cells in vitro

    Protective roles of ascorbic acid in oxidative stress induced by depletion of superoxide dismutase in vertebrate cells.

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    Superoxide dismutases (SODs) are antioxidant proteins that convert superoxide to hydrogen peroxide. In vertebrate cells, SOD1 is mainly present in the cytoplasm, with small levels also found in the nucleus and mitochondrial intermembrane space, and SOD2 is present in the mitochondrial matrix. Previously, the authors conditionally disrupted the SOD1 or SOD2 gene in DT40 cells and found that depletion of SOD1 caused lethality, while depletion of SOD2 led to growth retardation. The observations from previous work showed that the lethality observed in SOD1-depleted cells was completely rescued by ascorbic acid. Ascorbic acid is a water-soluble antioxidant present in biological fluids; however, the exact target for its antioxidant effects is not known. In this study, the authors demonstrated that ascorbic acid offset growth defects observed in SOD2-depleted cells and also lowered mitochondrial superoxide to physiological levels in both SOD1- or SOD2-depleted cells. Moreover, depletion of SOD1 or SOD2 resulted in the accumulation of intracellular oxidative stress, and this increased oxidative stress was reduced by ascorbic acid. Taken together, this study suggests that ascorbic acid can be applied as a nontoxic antioxidant that mimics the functions of cytoplasmic and mitochondrial SODs

    Remote-Controlled Drone System through Eye Movements of Patients Who Need Long-Term Care : An Intermediary’s Role

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    The use of a remote-controlled drone system (RDS) by eye movements was studied to assist patients in psychiatric long-term care (PLTC) to allow them to view the environment outside the hospital, hoping that this will bring them some enjoyment. However, successfully applying this system requires human intermediaries in facilitating the interactions between patients and RDS operators. The aim of the study was to describe the role of nurses as intermediaries in the application of an RDS through eye movements of patients PLTC. This study employed the Intentional Observational Clinical Research Design. Data collection was performed in November 2021 at a psychiatric hospital with selected patients in PLTC. Seventeen patients took part in the indoor experiment, whereas 23 patients took part in the outdoor experiment. Fifteen of the 23 patients in the outdoor experiment were the same patients who took part in the indoor experiment. Most of the patients in the indoor and outdoor test arenas could successfully, delightfully, and safely fly the drone. This study demonstrated that RDS using just eye movements could increase the quality of life in older patients with psychiatric problems in PLTC. For the successful use of this drone system, nurse intermediaries assumed critically significant roles

    Structure and dynamics of room temperature ionic liquids with bromide anion: Results from 81Br NMR spectroscopy

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    We report the results of a comprehensive 81Br NMR spectroscopic study of the structure and dynamics of two room temperature ionic liquids (RTILs), 1-butyl-3-methylimidazolium bromide ([C4mim]Br) and 1-butyl-2,3-dimethylimidazolium bromide ([C4C1mim]Br), in both liquid and crystalline states. NMR parameters in the gas phase are also simulated for stable ion pairs using quantum chemical calculations. The combination of 81Br spin-lattice and spin-spin relaxation measurements in the motionally narrowed region of the stable liquid state provides information on the correlation time of the translational motion of the cation. 81Br quadrupolar coupling constants (CQ) of the two RTILs were estimated to be 6.22 and 6.52 MHz in the crystalline state which were reduced by nearly 50% in the liquid state, although in the gas phase, the values are higher and span the range of 7-53 MHz depending on ion pair structure. The CQ can be correlated with the distance between the cation-anion pairs in all the three states. The 81Br CQ values of the bromide anion in the liquid state indicate the presence of some structural order in these RTILs, the degree of which decreases with increasing temperature. On the other hand, the ionicity of these RTILs is estimated from the combined knowledge of the isotropic chemical shift and the appropriate mean energy of the excited state. [C4C1mim]Br has higher ionicity than [C4mim]Br in the gas phase, while the situation is reverse for the liquid and the crystalline states. Copyright © 2015 John Wiley & Sons, Ltd

    Magnetic anisotropy driven by ligand in 4d transition metal oxide SrRuO3

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    The origin of magnetic anisotropy in magnetic compounds is a longstanding issue in solid state physics and nonmagnetic ligand ions are considered to contribute little to magnetic anisotropy. Here, we introduce the concept of ligand driven magnetic anisotropy in a complex transition-metal oxide. We conducted X ray absorption and X ray magnetic circular dichroism spectroscopies at the Ru and O edges in the 4d ferromagnetic metal SrRuO3. Systematic variation of the sample thickness in the range below 10 nm allowed us to control the localization of Ru 4d t2g states, which affects the magnetic coupling between the Ru and O ions. We found that the orbital magnetization of the ligand induced via hybridization with the Ru 4d orbital determines the magnetic anisotropy in SrRuO3

    エンドウのエリシター誘導性遺伝子発現におけるAAAGモチーフとPsDof1タンパク質の関与

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    Recently, we, isolated cDNA clone, PsDof1, from clicitor-treated pea cDNA library. The putative gene product, a PsDof1, encodes DNA binding protein that specifically binds the DNA fragment containing AAAG core sequence. In this paper we report that GST-PsDof1 fusion protein specifically binds to the promoter region containing AAAG core sequence(s) of PsCHS1, one of the elicitor-inducible genes encoding chalcone synthase (CHS). Furthermore the addition of DNA fragment containing AAAG motif to the 35S minimal promoter provided the elicitor-responsibility in transient transfection assay using pea protoplasts. These results suggest that PsDof1 might be involved in defense responses by acitivating the transcription by a binding to AAAG core sequence in the promoter of the defense-related genes in pea.エリシターを処理したエンドウ上胚軸由来のRNAから作成されたcDNAライブラリーからエリシター処理により発現が増高する遺伝子候補のcDNAとしてPsDof1が単離された.大腸菌で生産されたGST-PsDof1融合タンパク質はAAAG配列をコアとするDNAに結合することが明らかにされている.本論文ではGST-PsDof1がエリシター応答性遺伝子の一つ,PsCHS1のプロモーター上のAAAGまたはCTTT配列を有する断片に特異的に結合することを明らかにした.更にAAAG配列のエリシター応答性シスエレメントとしての機能を解析するため,AAAG配列を4回繰り返したユニットをCaMV35Sの最小プロモーターとCATレポーター遺伝子に連結したキメラ遺伝子を構築し,エンドウプロトプラストにエレクトロポレーション法により導入した.CAT活性を指にプロモーター活性を調べたところ,AAAG配列を有するプロモーターは,エリシター処理により活性化されることが明らかとなった.これらの結果はPsDof1がエリシター応答性防御遺伝子のプロモーター上のAAAG配列に結合し,転写を活性化させる可能性を示唆している
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