Physical and Electrochemical Properties of 1-ethyl-3-methylimidazolium Ionic Liquids of Mixed Anions, (FH)ₙF⁻, BF₄⁻, and N(SO₂CF₃)₂⁻

Physical and electrochemical properties of 1-ethyl-3-methylimidazolium ionic liquids of mixed anions, (FH)₂.₃F⁻, BF₄⁻, and N(SO₃)₂, have been investigated. Molar volume shows almost linear behavior, whereas molar conductivity is decreased by mixing for the systems involving (FH)₂.₃F⁻ due to the enhancement of ion association in spite of the decrease in viscosity. The currents at the anode and cathode limits in the cyclic voltammogram of EMIm(FH)₂.₃F decreases with decrease in the molar ratio of (FH)ₙF⁻, suggesting the involvement of (FH)ₙF⁻ for both electrode reactions. Electrochemical stability of the BF₄-TFSA mixture is unchanged by mixing

Cesium fluorohydrogenate, Cs(FH)₂.₃F

Cs(FH)₂.₃F is a liquid salt exhibiting a low viscosity of 20.1 cP and a high conductivity of 86.3 mS cm⁻¹ at 25 °C, in spite of the relatively high melting point (16.9 °C). The high density of 2.82 g cmÄ⁻³ at the liquid state is due to the heavy atomic weight and small size of cesium atom compared to the organic cations of general ionic liquids. The infrared spectroscopy indicates that this salt contains (FH)₂F⁻ as a main anionic species. The other anionic species such as (FH)₃F⁻ found in the cases of other M⁺(HF)₂.₃F (M = a univalent organic cation) ionic liquid salts is not detected, suggesting its small abundance as well as the presence of neutral HF in the form of molecular and/or oligomers. The result of ¹H NMR also suggests that the anions exchange HF between them. These observations coincide with the experimental result that Cs(FH)₂.₃F acts as an acid against general ionic liquid fluorohydrogenates such as EMIm(FH)₂.₃F (EMIm = 1-ethyl-3-methylimidazolium) to lose HF and give Cs(FH)₂F precipitate

Site-specific isotope labeling of long RNA for structural and mechanistic studies

A site-specific isotope labeling technique of long RNA molecules was established. This technique is comprised of two simple enzymatic reactions, namely a guanosine transfer reaction of group I self-splicing introns and a ligation with T4 DNA ligase. The trans-acting group I self-splicing intron with its external cofactor, ‘isotopically labeled guanosine 5′-monophosphate’ (5′-GMP), steadily gave a 5′-residue-labeled RNA fragment. This key reaction, in combination with a ligation of 5′-remainder non-labeled sequence, allowed us to prepare a site-specifically labeled RNA molecule in a high yield, and its production was confirmed with 15N NMR spectroscopy. Such a site-specifically labeled RNA molecule can be used to detect a molecular interaction and to probe chemical features of catalytically/structurally important residues with NMR spectroscopy and possibly Raman spectroscopy and mass spectrometry

Incremental Data Organization of Semi-structured Data Using Hierarchical Graph Model

本稿では, 半構造化データを段階的に構造化するための枠組みとして階層構造グラフモデルを導入する.ここでは、半構造化データの中でも特に試行錯誤的な構造化作業を必要するデータを対象に, データの集合化と属性の付与の2つの構造化作業について議論する.このモデルは利用者の視点を陽に扱い, 視点をデータとして取り扱うという特徴がある.階層構造グラフは, 有向グラフを基本としており、グラフ構造を表すオブジェクトとその要素を表すオブジェクトのオブジェクトの2段構造で構成することで, 複数の視点から多様な構造を持つデータを柔軟に構造化することができる.また, 視点に応じた半構造化データの多重な表現を与える目的で, 仮想オブジェクトの概念を導入し、利用者の仮説や直感に基づく上記のデータの構造化業を支援する.仮想オブジェクトは実行時に生成でき, 利用者はデータとして取り扱うことができる.最後に本モデルのプロトタイプシステムを示す.　In this paper, we propose the hierarchical graph model that enables flexible structuring of semi-structured data incrementally. Here we focus on the ways to collect data and add attributes to them in a trial and error manner. In this model, hierarchical graph is defined as a directed graph. We treat "viewpoints" as data explicitly, and treat both semi-structured data and viewpoints as nodes on the graph. The graph consists of component objects and a graph object. The former possesses the attributes of data and "viewpoints." The latter holds their relations. By this model, users can give multiple representations of semi-structured data based on user\u27s viewpoints. We introduce virtual objects in order to support the structuring according to user\u27s ad-hoc intuitions or hypotheses. Users can generate virtual objects at run-time, and treat them as data in our model. We also show a prototype system.新世代データベース技術 : インターネット・マルチメディア・モーバイルを中心として　Special Issue on New Generation Database Technology for Internet, Multimedia and Mobile computin

Intravenous alteplase for stroke with unknown time of onset guided by advanced imaging: systematic review and meta-analysis of individual patient data

Background: Patients who have had a stroke with unknown time of onset have been previously excluded from thrombolysis. We aimed to establish whether intravenous alteplase is safe and effective in such patients when salvageable tissue has been identified with imaging biomarkers. Methods: We did a systematic review and meta-analysis of individual patient data for trials published before Sept 21, 2020. Randomised trials of intravenous alteplase versus standard of care or placebo in adults with stroke with unknown time of onset with perfusion-diffusion MRI, perfusion CT, or MRI with diffusion weighted imaging-fluid attenuated inversion recovery (DWI-FLAIR) mismatch were eligible. The primary outcome was favourable functional outcome (score of 0–1 on the modified Rankin Scale [mRS]) at 90 days indicating no disability using an unconditional mixed-effect logistic-regression model fitted to estimate the treatment effect. Secondary outcomes were mRS shift towards a better functional outcome and independent outcome (mRS 0–2) at 90 days. Safety outcomes included death, severe disability or death (mRS score 4–6), and symptomatic intracranial haemorrhage. This study is registered with PROSPERO, CRD42020166903. Findings: Of 249 identified abstracts, four trials met our eligibility criteria for inclusion: WAKE-UP, EXTEND, THAWS, and ECASS-4. The four trials provided individual patient data for 843 individuals, of whom 429 (51%) were assigned to alteplase and 414 (49%) to placebo or standard care. A favourable outcome occurred in 199 (47%) of 420 patients with alteplase and in 160 (39%) of 409 patients among controls (adjusted odds ratio [OR] 1·49 [95% CI 1·10–2·03]; p=0·011), with low heterogeneity across studies (I 2=27%). Alteplase was associated with a significant shift towards better functional outcome (adjusted common OR 1·38 [95% CI 1·05–1·80]; p=0·019), and a higher odds of independent outcome (adjusted OR 1·50 [1·06–2·12]; p=0·022). In the alteplase group, 90 (21%) patients were severely disabled or died (mRS score 4–6), compared with 102 (25%) patients in the control group (adjusted OR 0·76 [0·52–1·11]; p=0·15). 27 (6%) patients died in the alteplase group and 14 (3%) patients died among controls (adjusted OR 2·06 [1·03–4·09]; p=0·040). The prevalence of symptomatic intracranial haemorrhage was higher in the alteplase group than among controls (11 [3%] vs two [<1%], adjusted OR 5·58 [1·22–25·50]; p=0·024). Interpretation: In patients who have had a stroke with unknown time of onset with a DWI-FLAIR or perfusion mismatch, intravenous alteplase resulted in better functional outcome at 90 days than placebo or standard care. A net benefit was observed for all functional outcomes despite an increased risk of symptomatic intracranial haemorrhage. Although there were more deaths with alteplase than placebo, there were fewer cases of severe disability or death. Funding: None