Difluoromethylborates and muonium for the study of isonitrile insertion affording phenanthridines via imidoyl radicals

The 6-(difluoromethyl)phenanthridine unit is a highly attractive fluoroalkyl-substituted planar nitrogen heterocycle in pharmaceutical and agrochemical research. In this paper, we report that difluoromethylborates can be used as a source of difluoromethyl radicals for isonitrile insertion, leading to 6-(difluoromethyl)phenanthridines. Tuning the aryl substituents in the difluoromethylborates and oxidizing reagents enabled the synthesis of 6-(difluoromethyl)phenanthridines through the generation of difluoromethyl radical and spontaneous intramolecular cyclization of the CF2H-imidoyl radical intermediates. The presence of difluoromethyl radicals was experimentally confirmed, and the reaction mechanisms including imidoyl radical and prompt cyclization reactions could be supported theoretically. Furthermore, we obtained valuable information about the imidoyl radical intermediate by performing transverse-field muon spin rotation (TF-μSR) measurements of 2-isocyano-4′-methoxy-1,1′-biphenyl and using density functional theory (DFT) calculations to interpret the spectra. Muonium, a simple free radical, preferentially adds to the carbon atom of the isonitrile unit, yielding the corresponding imidoyl radical. The temperature dependence of the muon hyperfine coupling constant and the spin relaxation of the muoniated radical signal are compatible with the intramolecular cyclization of biaryl-substituted imidoyl radicals on the μs time scale

External validation of a risk classification at the emergency department of post-cardiac arrest syndrome patients undergoing targeted temperature management

[Introduction]There are no established risk classification for post-cardiac arrest syndrome (PCAS) patients at the Emergency Department (ED) undergoing targeted temperature management (TTM). The aim of this study was to externally validate a simplified version of our prognostic score, the “post-Cardiac Arrest Syndrome for Therapeutic hypothermia score” (revised CAST [rCAST]) and estimate the predictive accuracy of the risk classification based on it. [Methods]For the external validation, we used data from an out-of-hospital cardiac arrest (OHCA) registry of the Japanese Association for Acute Medicine (JAAM), which is a multicenter, prospective registry of OHCA patients across Japan. Eligible patients were PCAS patients treated with TTM at 33–36 °C between June 2014 and December 2015. We validated the accuracy of rCAST for predicting the neurological outcomes at 30 and 90 days. [Results]Among the 12, 024 OHCA patients, the data of 460 PCAS patients treated by TTM were eligible for the validation. The areas under the curve of rCAST for predicting the neurological outcomes at 30 and 90 days were 0.892 and 0.895, respectively. The estimated sensitivity and specificity of the risk categories for the outcomes were as follows: 0.95 (95% CI: 0.92–0.98) and 0.47 (0.40–0.55) for the low (rCAST: ≤5.5), 0.62 (0.56–0.68) and 0.48 (0.40–0.55) for the moderate (rCAST: 6.0–14.0), and 0.57 (0.51–0.63) and 0.95 (0.91–0.98) for the high severity category (rCAST: ≥14.5). [Conclusions]The rCAST was useful for predicting the neurological outcomes with high accuracy in PCAS patients, and the three grades was developed for a risk classification based on the rCAST

FIELD EXPERIMENT TO CREATE AN ARTIFICIAL FISH REEF FOR Tridentiger obscurus IN THE AMAGASAKI CANAL

過栄養化した尼崎運河の環境を改善するために，付着藻類から上位の生物にまで及ぶ食物網の経路を創出することを考えた．本研究では，まずその端緒の検討として，底生魚のハゼ科チチブの保全を目的にした魚礁の構造と設置方法を把握することを目的に現地実験を行った．3種類の生息場をつくり，酸素不足が生じない水面付近の上層，中層，下層の3つの水深に沈設した． その結果，水底を選好するチチブであったが，夏期にはチチブは上層に移動，蝟集し，7月には下層の構造物にはチチブは確認できなくなった．ただし，夏期でも下層のDOは忌避行動をするようなレベルではなく，DOの他にも水温などが複合的に作用していることが示唆された．また構造物に独立した空隙を設けるとチチブの種内攻撃機会は減少し，小型のチチブも共に生息可能となることが推察された．To improve the environment of the Amagasaki Canal, a method for moving nutrients out of the system using a food web pathway derived from attached algae to fishes was investigated and field experiments were conducted. It was found that Tridentiger obscurus with bottom-dwelling properties gather in structures with some gap spaces installed near the water's surface. During the summer when water quality deteriorated, T. obscurus used the structures as a refuge. Such a structure would also reduce intraspecific competitions and allow for smaller T. obscurus to coinhabit around the shelter with the larger fish occupying the interstices of the structures. The stomach contents of T. obscurus suggested that they were feeding on attached algae and the shrimp in the structures. In addition, the T. obscurus were laying their eggs in the gap space of the structure

PROPOSALS FOR METHODS TO IMPROVE THE ENVIRONMENT OF THE AMAGASAKI CANAL, FOCUSING ON TROPHIC LEVEL OF Tridentiger obscurus

本研究では，チチブの栄養段階に着目して，尼崎運河の環境改善の方法について調査研究を行った．その結果，チチブは付着藻類を起点とする底生系の食物連鎖の上位にあり，またチチブを食する大型魚類の存在も示唆された．そこで，環境改善策として，積極的にチチブを保全し，運河内に過剰にある栄養塩をより多くの生物に利用されるようにすることを考えることができた．実際にチチブの保全のためのすみかを作成し，現地実験をした結果，適当なすみかの創出には，空隙がコウロエンカワヒバリガイによって閉塞されないような工夫が必要であることがわかった．This study focused on fish species to investigate methods for improving the environment of the Amagasaki Canal. Analysis of the food web revealed that a benthic fish species Tridentiger obscurus has an important role in transferring energy from primary producers to organisms at higher trophic levels. The result suggest that protection of the bottom dwelling T. obscurus is effective for improving the environment of the canal by making excessive nutrients ingestible for other organisms. When artificial shelters for T. obscurus was set in the canal, a large amount of mussel Xenostrobus securi attached to the shelter. The result insists that further improvements are needed to prevent clogging by the shells and make shelters available for T. obscurus

FISH DIVERSITY DETECTION AT THE INNER PART OF OSAKA BAY USING ENVIRONMENTAL DNA ANALYSIS

大阪湾奥に位置する尼崎運河において，環境DNA調査と捕獲調査を比較して運河内スケールにおける環境DNAの有効性と問題点を検討し，各調査地点の魚類相の比較および環境条件との関連を明らかにした．東堀では1月の表層のORPやDOが回復し，同時期の環境DNAにより検出された種数が最も多かった．このことから，この場所が水質の回復によって魚類の利用場所となるポテンシャルを持っている可能性が示唆された．環境DNA調査はより環境の異なる港湾との比較や季節変化については差の検出が可能であった．環境DNA調査は検出は不安定で，検出できない種もあるが，採捕調査よりも多くの魚種を検出する傾向にあり，直接採捕の調査と合わせると互いの調査方法の結果を補い，魚類相全体の把握に有効な手法であると考えられる．Fish diversity at at Amagasaki canal in the Inner Part of Osaka Bay were investigated by environmental DNA analysis (eDNA) to clarify whether this method is valuable in eutrophic conditions. A ORP and DO was restored in January in Higashi-bori sampling point and the detected fish species was larger number than the other time. The result suggests that Higashi-bori has a potential for fish habitat with a water quality recovery. The number of detected species and fish fauna suggests that eDNA is efficient in comparison among sampling points which has sharp contrast of environmental factors and monitoring seasonal difference. The eDNA is unable to detected a certain species, but allow to detect larger number of species than the conventional sampling methods. eDNA is most effective when used in conjunction with conventional sampling method for investigation of fish diversity

A STUDY ON THE SHAPE OF A STRUCTURE FOR MITIGATING THE IMPACT OF LONG-TERM HYPOXIA OCCURRING IN ALL LAYERS ON TRIDENTIGER OBSCURUS

底層から表層までの全層にわたって貧酸素化が起こる水環境中で，その貧酸素化の影響を緩和することのできる構造物の形状についての検討を行った．尼崎運河は，慢性的に貧酸素化しており，時には全層で貧酸素化し，年間を通して生存が確認される魚種は底生魚のチチブだけであった．空隙を有する構造物を表層に設置すると，底層のみが貧酸素化するときには，そこを代替の棲み処とし，また全層で貧酸素化したときには水面付近に沈められた板の上に乗り，再曝気されたわずかな酸素を求めて水面に向かって鼻上げ行動をすることがわかった．この時，空隙への選好行動やなわばり行動などのチチブの一般的な行動は認められなかった．以上のことより，貧酸素化する水域では，空隙と定位可能な底面を有する構造物を水面付近に設置するとチチブの避難場として機能することがわかった．The shape of a structure capable of mitigating the impact of hypoxia in water environments where hypoxia occurs in all layers from the bottom to the top was studied. The Amagasaki Canal is chronically hypoxic; occasionally all layers are hypoxic. The only fish confirmed to live in this canal throughout the year is the benthonic fish Tridentiger obscurus. This study showed that if a structure with gaps is installed in the surface layer, when only the bottom layer is hypoxic, the fish uses it as a substitute habitat. When all layers are hypoxic, the fish swims above the plate submerged near the water’s surface to obtain aminiscule amount of reaerated oxygen and raise its nose to the surface. Under this condition, Tridentiger obscurus’ preference for and tendency to occupy gaps is absent. The aforementioned observations show that an effective means to mitigate the impact of hypoxia on Tridentiger obscurus is installation of structures with gaps and a bottom surface that the fish can settle on near the water surface

Prediction of Prehospital Change of the Cardiac Rhythm From Nonshockable to Shockable in Out‐of‐Hospital Patients With Cardiac Arrest: A Post Hoc Analysis of a Nationwide, Multicenter, Prospective Registry

Background Predicting a spontaneous rhythm change from nonshockable to shockable before hospital arrival in patients with out‐of‐hospital cardiac arrest can help emergency medical services develop better strategies for prehospital treatment. The aim of this study was to identify predictors of spontaneous rhythm change before hospital arrival in patients with out‐of‐hospital cardiac arrest and develop a predictive scoring system. Methods and Results We retrospectively reviewed data of eligible patients with out‐of‐hospital cardiac arrest with an initial nonshockable rhythm registered in a nationwide registry between June 2014 and December 2017. We performed a multivariable analysis using a Cox proportional hazards model to identify predictors of a spontaneous rhythm change, and a ridge regression model for predicting it. The data of 25 804 patients were analyzed (derivation cohort, n=17 743; validation cohort, n=8061). The rhythm change event rate was 4.1% (724/17 743) in the derivation cohort, and 4.0% (326/8061) in the validation cohorts. Age, sex, presence of a witness, initial rhythm, chest compression by a bystander, shock with an automated external defibrillator by a bystander, and cause of the cardiac arrest were all found to be independently associated with spontaneous rhythm change before hospital arrival. Based on this finding, we developed and validated the Rhythm Change Before Hospital Arrival for Nonshockable score. The Harrell’s concordance index values of the score were 0.71 and 0.67 in the internal and external validations, respectively. Conclusions Seven factors were identified as predictors of a spontaneous rhythm change from nonshockable to shockable before hospital arrival. We developed and validated a score to predict rhythm change before hospital arrival