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We assessed the contamination, dynamics, and health risks of the pesticides cyanazine, simetryn, fenarimol, isoprothiolane, diazinon, irgarol, fenitrothion, and diuron in marine samples (seawater, sediments, plankton, fish, and other edible organisms) at various locations in the Seto Inland Sea in Japan in 2016 and 2017. Pesticide concentrations were highest at sampling sites close to the coastline, and mean concentrations in seawater were slightly higher in surface water than in bottom water. All eight pesticides were detected in plankton. Diazinon concentrations (77-387 ng/g dw) were highest in sediments and cyanazine was the most frequently detected pesticide (88%, n = 17) in sediments. Only cyanazine (2.7-41.9 ng/g dw), simetryn (1.0-34.3 ng/g dw), and diazinon (6.3-308.8 ng/g dw) were detected in fish and other edible marine organisms. Based on the calculated bioconcentration factor, the results showed that plankton, fish, and marine animals bioaccumulated pesticides. The highest hazard quotients were calculated for diazinon in red seabream and greenling, indicating a possible risk to consumers. It is, therefore, imperative to promote strict implementation of pollution control, integrated pest management practices, and policy formulation on pesticides. Usage of diazinon must be controlled and monitored to ensure large residues do not reach aquatic ecosystems and marine coastlines.

We herein report an extremely rare case of adenocarcinoma of the minor duodenal papilla (MiDP) which was successfully treated by endoscopic mucosal resection (EMR). An asymptomatic 84-year-old man underwent upper gastrointestinal endoscopy, which revealed a slightly elevated lesion at the MiDP. The biopsy findings were suggestive of adenocarcinoma. Computed tomography, magnetic resonance images and endoscopic ultrasonography did not reveal pancreatic tumor infiltration nor any apparent distant metastases. Therefore, we treated the lesion using EMR with complete resection. No recurrence or metastasis has been detected at 13 months after EMR. Total resection of the MiDP can thus serve as a relatively safe and simple treatment.

Transition metal-catalyzed regioselective hydroboration of 1,3-dienes has received continuous interest in the field of organic synthesis. Herein, we describe the nickel-catalyzed Markovnikov 1,2-hy...

A study for the development of the nickel-catalyzed highly enantioselective propargylic amination of propargylic carbonates with aniline derivatives is described. The reaction of internal alkyne-su...

INTRODUCTION: During the coronavirus disease 2019 pandemic, whether endoscopy generates aerosols needs to be determined. METHODS: In patients undergoing upper gastrointestinal endoscopy with an enclosure covering their heads, 0.3-10-µm aerosols were measured for 60 seconds before, during, and after endoscopy by an optical counter. Whether aerosols increased in the situation with and without endoscopy was examined. RESULTS: The analysis included 103 consecutive patients undergoing endoscopy and 90 control patients. Aerosols increased significantly during endoscopy compared with the control group. Body mass index and burping were significant factors related to increased aerosols during endoscopy. DISCUSSION: Upper gastrointestinal endoscopy was an aerosol-generating procedure.

Polycyclic aromatic hydrocarbons (PAHs) were analyzed to elucidate the distribution, ecological risk, pathways, and fluxes of these pollutants in and around the Seto Inland Sea, an industrialized coastal region of Japan. High molecular weight PAHs (5-6 rings) were primarily found in regions close to the bay estuaries, and their proportions decreased at distances further from the estuaries (offshore areas), where low molecular weight PAHs (2-4 rings) were more ubiquitous. Screening-level risk assessments revealed that the PAHs found in the sediments should have no adverse effects on benthic communities. A mass balance for PAHs in the Seto Inland Sea, calculated based on data collected in the field and published literature findings, showed the PAH flux into the Seto Inland Sea from atmospheric deposition were ca. 6 times higher than that from riverine inflows. Comparison of the amount of the PAH mass flux between the Seto Inland Sea and the sea of the Europe and Asian countries indicated that the Seto Inland Sea is less polluted than the Gulf of Lion, the Mediterranean Sea, and the Bohai Sea, China and more polluted than the Yellow Sea. This paper is the first to determine the fluxes of PAHs in the coastal region of Japan.

We demonstrated a ruthenium-catalyzed regioselective allylic amination of tertiary allylic esters with various amines using [Cp*Ru(CH3CN)3][PF6]/5,5′-dimethyl-2,2′-bipyridine (5,5′-diMe-2,2′-bpy) a...

The nickel-catalyzed highly enantioselective Friedel–Crafts propargylation of 3-substituted indoles with propargylic carbonates bearing an internal alkyne group was developed. A wide array of the propargylic carbonates as well as 3-substituted indoles can be applicable to the asymmetric nickel catalysis, providing the corresponding chiral C-3 propargylated indolenine derivatives bearing two vicinal chiral centers in up to 89% yield with up to >99% ee and 94:6 dr (24 examples).

We have accomplished the ruthenium-catalyzed benzylic substitution of benzyl esters with a stabilized carbon nucleophile. A [Cp*RuCl2]2/picolinic acid catalyst system promoted the reaction of 2-naphthylmethyl-2,3,4,5,6-pentafluorobenzoates with a series of stabilized carbon nucleophiles such as malonates, β-ketoesters, and diketones to give the corresponding benzylic alkylation products in moderate to high yields. We proposed a plausible reaction mechanism that could involve a (π-benzyl)ruthenium intermediate.

Nickel-catalyzed transformation of alkene-tethered oxime ethers to nitriles using a traceless directing group strategy has been developed. A series of alkene-tethered oxime ethers derived from benzaldehyde and cinnamyl aldehyde derivatives were converted into the corresponding benzonitriles and cinnamonitriles in 46-98% yields using the nickel catalyst system. Control experiments showed that the alkene group tethered to an oxygen atom on the oximes via one methylene unit plays a key role as a traceless directing group during the catalysis.

Background/Aims: Residual common bile duct (CBD) stones occasionally become symptomatic after stone removal with endoscopic retrograde cholangiopancreatography (ERCP) upon removal of the endoscopic biliary stent (EBS). An accurate evaluation of residual stones before stent removal is necessary. This study evaluated a new two-step check method using endoscopic ultrasound (EUS) for the detection of residual stones after ERCP stone removal. Methods: Fifty-six patients who underwent CBD stone removal and EBS placement were prospectively enrolled. Residual stones were evaluated by the check method. EBS was removed at the time of the check method or at a later time of residual stone removal. The primary outcome was to evaluate the efficacy of this check method. Results: Residual CBD stone/sludge was detected in 20 of 56 patients (35.7%; stones: 28.6%, sludge: 7.1%) by the check method and removed by the ERCP procedure at a later time. After stent and final stone removal, patients were followed for an average of 211 days; cholangitis recurred in only 1.8% of patients. There were no adverse events associated with the check method. Temporary EBS prevented the recurrence of cholangitis by residual stone and caused no adverse events in the pancreatobiliary tract until the two-step check method (median, 113 days; range, 17–232 days). Conclusion: The new check method may be ideal and feasible for EBS removal because recurrences are very rare when a clear CBD has been verified, and an additional ERCP procedure is also possibly avoided.

We investigated the palladium-catalyzed [2 + 2 + 1] cycloaddition of aryl- and trifluoromethyl-group-substituted internal alkynes and carbon monoxide, and revealed that the PdBr2 effectively catalyzed the intended reaction. The PdBr2-catalyzed reaction smoothly proceeded and provided aryl- and trifluoromethyl-group-containing cyclopentadienone derivatives in up to 92% yield.

We describe herein the synthetic method to benzoxazole derivatives via the copper-catalyzed hydroamination of alkynones with 2-aminophenols. The method produced a wide variety of functionalized benzoxazole derivatives in good yields. Preliminary mechanistic experiments revealed that the reaction would proceed through the copper-catalyzed hydroamination of alkynones and the sequential intramolecular cyclization of β-iminoketones/elimination of acetophenone promoted by the copper catalyst.

The synthesis of the trifluoromethyl group containing enol ethers by the palladium-catalyzed intermolecular reaction of 2,3,3-trifluoroallylic carbonates with oxygen nucleophiles was accomplished. The reaction proceeds through the intermolecular attack of oxygen nucleophiles on the C-2 carbon atom of the allylic unit, and the intramolecular fluorine atom shift from the C-2 position to the C-3 position. The reactions with several types of alcohols and phenols proceeded smoothly, and afforded the corresponding trifluoromethyl group containing enol ethers in good to high yields.

We accomplished the palladium-catalyzed double substitution of 2-haloallylic acetates with nitrogen nucleophiles. During the Pd2(dba)3/DPPE-catalyzed reaction of 2-fluoroallylic acetates with N-substituted-p-toluenesulfonamide, two equivalents of nitrogen nucleophiles were introduced to the allyl unit with a Z-selectivity through the carbon–fluorine bond cleavage. We further demonstrated the reaction of 2-chloroallylic acetates, and succeeded in obtaining the same doubly-substituted products in good yields with a high Z-selectivity.

A catalytic method for the formation of amide bonds was developed in which the amidation of N-hydroxyimino esters with a broad range of amino acid tert-butyl esters is promoted by a niobium catalyst in the absence of solvent. Contrary to the predominant protocol based on reagent control commonly applied to amidation reactions, this study provides insight into an approach based on substrate control. This system affords the corresponding amides in high yields in addition to being both highly atom efficient and racemization-free. An advantage of this system is shown in that the Lewis acid catalysis proceeds chemoselectively in the presence of nonactivated esters. Furthermore, the resulting amides are easily transformed into their corresponding di- and tripeptides with high diastereoselectivities under simple hydrogenation conditions.

We have found that a boronic acid catalyzed amidation of an N-hydroxy amino acid methyl ester with amino acid tert-butyl esters gave N-hydroxy dipeptide derivatives in good yields without any racemization. The protecting groups on the nitrogen atom could be easily removed by heterogeneous hydrogenation conditions.

We accomplished the synthesis of 2-substituted benzofuran derivatives by the palladium-catalyzed reaction of 2-haloallylic acetates with simple phenols in the presence of a base. The reaction proceeded through the intermolecular attack of the nucleophile on the central carbon atom of the π-allyl group, carbon-halogen bond cleavage, and sequential intramolecular cyclization.

Background Endoscopic ultrasound-guided gallbladder drainage (EUS-GBD) as a treatment for patients with acute cholecystitis has been shown to obtain high technical and clinical success rates and a low recurrence rate. However, the safety of EUS-GBD for patients receiving antithrombotic therapy (ATT) has not been proven. The aim was to evaluate the safety and efficacy of EUS-GBD in patients receiving ATT. Methods Twelve patients with acute cholecystitis associated with gallstones who were receiving antithrombotic therapy and underwent EUS-GBD were enrolled in this retrospective study. Patients with grade II or III cholecystitis who had failed endoscopic transpapillary GBD (ETGBD) or developed recurrence after multiple ETGBD procedures underwent urgent drainage by EUS-GBD. The primary outcome was the rate of bleeding complications after the procedure and the secondary outcomes were the technical and clinical success rates, complications, and recurrence. Results Eleven (91.6%) patients underwent EUS-GBD with continuation of ATT (at least 1 agent). Five of 12 patients (41.7%) were receiving more than 1 agent for ATT. The rate of bleeding complications was 0% and the technical success rate was 100%, even though some patients had high-grade (severe) cholecystitis and/or several underlying diseases. Early complications were found in 2 (16.7%) patients. The clinical success rate was 91.7% (11/12). There were no recurrences of cholecystitis during the follow-up period (mean 261 [range 5-650] days). Conclusions EUS-GBD yielded high technical and clinical success rates and a low recurrence rate. No patients receiving ATT developed bleeding complications. EUS-GBD might be a good option for patients on ATT.

The nickel-catalyzed hydroarylation of 1,3-dienes with arylboronic acids using a secondary homoallyl carbonate as a surrogate for the 1,3-diene and hydride source has been developed. The synthetic strategy allowed an efficient access to a wide array of hydroarylation products in high yields with high functional group compatibility without the use of an external hydride source. Mechanistic experiments indicated that the alkene-directed oxidative addition and subsequent β-hydride elimination would be a critical process in this transformation.

We have developed a novel synthetic method accessing benzo[b][1,4]oxazepines that are one of the rare classes of benzoxazepine derivatives by reaction of 2-aminophenols with alkynones in 1,4-dioxane at 100 °C. A series of benzo[b][1,4]oxazepine derivatives can be prepared by using this synthetic protocol. Mechanistic experiments indicated that the hydroxy proton of the aminophenol could play a crucial role in the formation of an alkynylketimine intermediate that undergoes 7-endo-dig cyclization.

The nickel-catalyzed benzylic substitution of benzyl alcohol derivatives with a soft carbon nucleophile is extremely rare compared to that with a hard carbon nucleophile. We have achieved the nickel-catalyzed benzylic substitution of benzyl esters with malonates as a soft carbon nucleophile. Primary and secondary benzyl 2,3,4,5,6-pentafluorobenzoates as well as a wide variety of malonate derivatives were well tolerated in the nickel-catalyzed reaction, providing the corresponding alkylation products in 46–86% yields (34 examples). Additionally, we propose a possible reaction mechanism that would undergo via the η1- and η3-benzylnickel intermediates.

The transition metal-catalyzed stereospecific benzylic alkylation of optically active benzyl esters with active methylene compounds remains extremely rare. Herein, we describe the study for the ruthenium-catalyzed benzylic alkylation of chiral benzyl esters with malonates as a carbon nucleophile. A combination of [Cp*RuCl2]2 and picolinic acid found to be effective for the title reaction, providing the chiral benzylic alkylation products with retention of stereochemistry of the starting material. We proposed that the ruthenium catalysis would proceed via a double inversion mechanism.

The use of a malonate nucleophile in the transition metal-catalyzed hydroalkylation of 1,3-dienes remains immature. Herein, we report the nickel-catalyzed hydroalkylation of 1,3-dienes with malonates using a homoallyl carbonate as the 1,3-diene and hydride source. A broad range of homoally carbonates and malonate derivatives were well tolerated under a Ni/DPEphos catalyst system, providing the corresponding 1,2-hydroalkylation products in 40–94% yields with excellent regioselectivity (32 examples). We also suggested the possible reaction mechanism for the nickel-catalyzed hydroalkylation of in situ generated 1,3-dienes with malonates.

We describe herein a new strategy for the chemoselective synthesis of amides by using a metal-catalyzed hydroxy-directed reaction. A hydroxy group located at the β-position of an ester group promoted the activation of a carbonyl group with a tantalum alkoxide catalyst followed by amidation reactions, leading to a wide variety of β-hydroxyamides with excellent chemeselectivity. The chemoselective amidation strategy can be extended to the catalytic synthesis of dipeptide derivatives, which remains challenging research subjects in modern organic synthesis.

外傷性椎骨骨折が疑われる患者41名に、仮想non-calciumイメージングを用いたdual source CT(DSCT)を施行した。比較のために被曝低減機構を搭載したDSCT(n=11)およびMDCT(n=14)を施行した。23名で仮想non-calcium画像が得られた。non-calciumイメージングでは、他の方法と比べて被曝線量が少なかった。損傷椎骨(n=25)のCT値は正常椎骨(n=25)と比べて有意に高かった(7.68±22.4対50.48±15.13HU)。CT値の閾値を-25.6HUに設定すると、感度は100%、特異度は92.6%となった。ほとんどの症例で仮想non-calcium画像はMRIの脂肪抑制T2強調像より劣っていた。DSCTを用いて得られる仮想non-calcium画像技術は椎骨骨折の臨床診断の一部として有用であると考えられた。

Mechanistic studies on the organoborane-catalyzed transfer hydrogenation of nonactivated aldehydes with a Hantzsch ester (diethyl-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate) as a synthetic NADH analogue were performed by NMR experiments and DFT calculations. In the reaction of benzaldehyde with the Hantzsch ester, the catalytic activity of tris[3,5-bis(trifluoromethyl)phenyl]borane was superior to that of other borane catalysts, such as tris(pentafluorophenyl)borane, trifluoroborane etherate, or triphenylborane. Stoichiometric NMR experiments demonstrated that the hydrogenation process proceeds through activation of the aldehyde by the borane catalyst, followed by hydride transfer from the Hantzsch ester to the resulting activated aldehyde. DFT calculations for the hydrogenation of benzaldehyde with the Hantzsch ester in the presence of borane catalysts supported the reaction pathway and showed why the catalytic activity of tris[3,5-bis(trifluoromethyl)phenyl]borane is higher than that of the other boron catalysts. Association constants and Gibbs free energies in the reaction of boron catalysts with benzaldehyde or benzyl alcohol, which were investigated by 1H NMR analyses, also indicated why tris[3,5-bis(trifluoromethyl)phenyl]borane is a superior catalyst to tris(pentafluorophenyl)borane, trifluoroborane etherate, or triphenylborane in the hydrogenation reaction.

We have achieved the nickel-catalyzed asymmetric propargylic amination of propargylic carbonates bearing an internal alkyne group. A wide variety of propargylic carbonates and N-methylaniline derivatives were tolerated under the reaction conditions, providing the corresponding chiral propargylic amines in up to 97% yield with up to 97% ee.

We have developed a method for the hydrogenation of unactivated aldehydes, using a Hantzsch ester as a NAD(P)H analogue in the presence of an electron-deficient triarylborane as a Lewis acid catalyst. Thus, tris[3,5-bis(trifluoromethyl)phenyl]borane efficiently catalyzes the hydrogenation of aliphatic aldehydes with a Hantzsch ester in 1,4-dioxane at 100 °C to give the corresponding aliphatic primary alcohols in up to 97% yield. Aromatic aldehydes also undergo the hydrogenation, even at 25 °C, to furnish the corresponding aromatic primary alcohols in up to 100% yield.

Environmental contextPolycyclic aromatic hydrocarbons are carcinogenic environmental contaminants that tend to migrate into the sediments in oceans and seas. Their vertical distribution in sediments from the Seto Inland Sea matched their emission over time, which in turn reflected changes in energy sources and industrial activities in Japan. This study shows that human activities on land directly and significantly influence the concentration of polycyclic aromatic hydrocarbons in sediments. AbstractSeventeen polycyclic aromatic hydrocarbons (PAHs) were identified in sediment cores collected at several locations in the Seto Inland Sea in 2015 and 2016 to understand their spatial distribution and potential emission sources. PAHs were analysed using gas chromatography–mass spectrometry. The age of the sediment cores was analysed using radioisotopic dating techniques to reconstruct historical PAH emissions. The total concentrations of 17 PAHs in the sediment cores of Osaka Bay in 2015 were in the range of 108–2810ng g−1 dry weight (dw) with a mean concentration of 1050ng g−1 dw. The total concentrations of 17 PAHs in sediment cores from the Seto Inland Sea in 2016 were in the range of 52.6–941ng g−1 dw with a mean concentration of 313ng g−1 dw. The spatial distribution of PAHs showed the highest concentration in Osaka Bay and the lowest in Kii Channel in 2016. The horizontal PAH distribution showed a decreasing trend in concentrations from the estuary offshore to Osaka Bay and Aki-Nada. The vertical PAH distribution revealed that levels were higher before the 1980s–1990s, when oil consumption and industrial activities in the Osaka region reached a maximum in the 20th century. The diagnostic ratios of PAHs and a principal component analysis revealed three main emission sources of PAHs, industry, biomass burning and traffic activities.

The copper-catalyzed regioselective allylic cyanation of allylic compounds with trimethylsilyl cyanide (TMSCN) is described. Copper(I) iodide (CuI), copper(I) cyanide (CuCN) and copper(II) chloride (CuCl2) are shown to effectively catalyze the cyanation of various allylic substrates to afford the corresponding allylic cyanides in good yields and high regioselectivities. The reaction in the presence of 2,2,6,6-tetramethyl-1-piperidinyloxy free radical (TEMPO) reveals that the cyanation proceeds via a radical pathway.

It is important to understand friction force in micro/nano mechanical devices both at high sliding speed and with high lateral resolution. Dual-axis friction force microscopes that can provide high lateral resolution and accuracy have been proposed; however, the sliding speed is limited by the probe scan speed. While a micro mechanical probe (MMP) with an electrostatic actuator can overcome this problem, details of probe design have not been established yet. This paper presents the principle of the mechanical design for an MMP with high force sensitivity and sufficient drive force. The dimensions of the double cantilever beam control the spring constants, resonant frequencies, and drive force. The use of an actuated MMP enables accurate friction force microscopy at high sliding speeds, which is required for the design of micro/nano mechanical devices.

The iridium-catalyzed allylic alkylation with azlactone and sequential aza-Cope rearrangement was demonstrated. The sequential reaction was effective in separating of diastereoisomers and afforded a diastereomerically pure azlactone derivative and oxazolinone derivative.

The regiospecific nucleophilic substitution during the ruthenium catalyzed allylic alkylation of 1,3-unsymmetrical disubstituted allylic esters was demonstrated. The nucleophile was selectively introduced at the position originally substituted with leaving group in the 2-DPPBA or ip-pybox ligated [RuCl(2)(p-cymene)](2) catalyzed allylic alkylation of 1,3-unsymmetrical disubstituted allylic esters. The chirality of the optically active allylic esters was also transferred to the alkylated products.

Pt/Au/C and Pt/Pd/C core-shell catalysts were prepared from Au/C and Pd/C cores with different core sizes using under potential deposition (UPD) of Cu, and the activity for oxygen reduction reaction and durability of the Pt/Au/C and Pt/Pd/C catalysts were investigated. Pt/Au/C and Pt/Pd/C core-shell catalysts showed higher mass activities than a commercially available Pt2.8nm/C catalyst, and hence they are promising for reducing the Pt usage in PEFCS. In potential cycling durability tests between 0.6-1.0 V, opposite effects of core size on were observed for Pt/Au/C and Pt/Pd/C. For Pt/Au/C, smaller cores gave high durability, whereas for Pt/Pd/C, larger cores gave high durability comparable with the Pt2.8nm/C.

The hyperthermostable chitinase from the hyperthermophilic archaeon Pyrococcus furiosus has a unique multidomain structure containing two chitin-binding domains and two catalytic domains, and exhibits strong crystalline chitin hydrolyzing activity at high temperature. In order to investigate the structure–function relationship of this chitinase, we analyzed one of the catalytic domains (AD2) using mutational and kinetic approaches, and determined the crystal structure of AD2 complexed with chito-oligosaccharide substrate. Kinetic studies showed that, among the acidic residues in the signature sequence of family 18 chitinases (DXDXE motif), the second Asp (D2) and Glu (E) residues play critical roles in the catalysis of archaeal chitinase. Crystallographic analyses showed that the side-chain of the catalytic proton-donating E residue is restrained into the favorable conformer for proton donation by a hydrogen bond interaction with the adjacent D2 residue. The comparison of active site conformations of family 18 chitinases provides a new criterion for the subclassification of family 18 chitinase based on the conformational change of the D2 residue.

Adult living donor liver transplantation (LDLT) was developed against the background of a scarcity of deceased donors and has a number of disadvantages leading to in-hospital mortality, such as marginal donors and grafts and recipients suffering from severe conditions. We have thus developed surgical and medical innovations to overcome these disadvantages. The present study analyzes the causes of death and factors affecting in-hospital mortality in adult recipients of LDLT. Between November 1994 and December 2007, 576 consecutive adult patients underwent LDLT at a single medical center. Overall in-hospital mortality was 18.9%. The peak rate was 55.6% in 1996, and the rate gradually decreased thereafter to 4.4% in 2007. The most frequent cause of death was infection (62.5%), which was followed by rejection (15.7%) and nonseptic multiple-organ failure (8.9%). Being intensive care unit-bound before the operation, ABO blood type incompatibility, an absence of postoperative enteral nutrition, and a Model for End-Stage Liver Disease score of 25 or higher were independent risk factors for in-hospital mortality. In ABO-identical and ABO-compatible cases, retransplantation and a positive lymphocyte crossmatch test were additional independent risk factors. In conclusion, even aggressive efforts, preoperative conditions such as being intensive care unit-bound, a high Model for End-Stage Liver Disease score, retransplantation, and a positive lymphocyte crossmatch test are still risk factors. Enteral nutrition could be a promising strategy to improve adult LDLT.