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1.
J Phys Chem B ; 128(25): 6134-6150, 2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-38874477

RESUMO

Due to their many attractive physicochemical properties, ionic liquids (ILs) have received extensive attention with numerous applications proposed in various fields of science and technology. Despite this, the molecular origins of many of their properties, such as the moisture absorption capability, are still not well understood. For insight into this, we systematically synthesized 24 types of ILs by the combination of the dimethyl phosphate anion with various types of alkyl group-substituted cyclic cations─imidazolium, pyrazolium, 1,2,3-triazolium, and 1,2,4-triazolium cations─and performed a detailed analysis of the dehumidification properties of these ILs and their aqueous solutions. It was found that these IL systems have a high dehumidification capability (DC). Among the monocationic ILs, the best performance was obtained with 1-cyclohexylmethyl-4-methyl-1,2,4-triazolium dimethyl phosphate, whose DC (per mol) value is 14 times higher than that of popular solid desiccants like CaCl2 and silica gel. Dicationic ILs, such as 1,1'-(propane-1,3-diyl)bis(4-methyl-1,2,4-triazolium) bis(dimethyl phosphate), showed an even better moisture absorption, with a DC (per mol) value about 20 times higher than that of CaCl2. Small- and wide-angle X-ray scattering measurements of eight types of 1,2,4-triazolium dimethyl phosphate ILs were performed and revealed that the majority of these ILs form nanostructures. Such nanostructures, which vary with the identity of the IL and the water content, fall into three main categories: bicontinuous microemulsions, hexagonal cylinders, and micelle-like structures. Water in the solutions exists primarily in polar regions in the nanostructures; these spaces function as water pockets at relatively low water concentrations. Since the structure and stability of the aggregated forms of the ILs are mainly governed by the interactions of nonpolar groups, the alkyl side chains of the cations play an important role in the DC and temperature-dependent equilibrium water vapor pressure of the IL solutions. Our experimental findings and molecular dynamics simulation results shed light on the moisture absorption mechanism of the IL aqueous solutions from a molecular perspective.

2.
ACS Appl Mater Interfaces ; 15(42): 49712-49726, 2023 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-37815984

RESUMO

Device implementation of reservoir computing, which is expected to enable high-performance data processing in simple neural networks at a low computational cost, is an important technology to accelerate the use of artificial intelligence in the real-world edge computing domain. Here, we propose an ionic liquid-based physical reservoir device (IL-PRD), in which copper cations dissolved in an IL induce diverse electrochemical current responses. The origin of the electrochemical current from the IL-PRD was investigated spectroscopically in detail. After operating the device under various operating conditions, X-ray photoelectron spectroscopy of the IL-PRD revealed that electrochemical reactions involving Cu, Cu2O, Cu(OH)2, CuSx, and H2O occur at the Pt electrode/IL interface. These products are considered information transmission materials in IL-PRD similar to neurotransmitters in biological neurons. By introducing the Faradaic current components due to the electrochemical reactions of these materials into the output signal of IL-PRD, we succeeded in improving the time-series data processing performance of the nonlinear autoregressive moving average task. In addition, the information processing efficiency in machine learning to classify electrocardiogram signal waveforms was successfully improved by using the output current from IL-PRD. Optimizing the electrochemical reaction products of IL-PRD is expected to advance data processing technology in society.

3.
Faraday Discuss ; 247(0): 59-69, 2023 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-37466008

RESUMO

Automated electrochemical assembly is an electrochemical method to synthesise middle-sized molecules, including linear oligosaccharides, and some linear oligosaccharides can be electrochemically converted into the corresponding cyclic oligosaccharides effectively. In this study, the target cyclic oligosaccharide is a protected cyclic (1,3;1,6)-ß-glucan dodecasaccharide, which consists of two types of glucose trisaccharides with ß-(1,3)- and ß-(1,6)-glycosidic linkages. The formation of the protected cyclic dodecasaccharide was confirmed by the electrochemical one-pot dimerisation-cyclisation of the semi-circular hexasaccharide. The yield of the protected cyclic dodecasaccharide was improved by using a stepwise synthesis via the linear dodecasaccharide.


Assuntos
beta-Glucanas , beta-Glucanas/química , Oligossacarídeos/química , Dimerização
4.
Chem Rec ; 23(9): e202300028, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36949016

RESUMO

The incorporation of fluorine atoms into an organic compound can alter the chemical reactivity or biological activity of the resulting compound due to the strong electron withdrawing nature of the fluorine atom. We have synthesized many original gem-difluorinated compounds and described the results in four sections. The first section describes the synthesis of optically active-gem-difluorocyclopropanes via the chemo-enzymatic reaction; we applied these compounds to liquid crystalline molecules, then further discovered a potent DNA cleavage activity for the gem-difluorocyclopropane derivatives. The second section describes the synthesis of selectively gem-difluorinated compounds via a radical reaction; we synthesized fluorinated analogues of a sex pheromone of the male African sugarcane borer, Eldana saccharina, and used the compounds as proof for investigating the origin of pheromone molecule recognition on the receptor protein. The third involves the synthesis of 2,2-difluorinated-esters by visible light-driven radical addition of 2,2-difluoroacetate with alkenes or alkynes in the presence of an organic pigment. The last section describes the synthesis of gem-difluorinated compounds via the ring-opening of gem-difluorocyclopropanes. We further developed a novel method of synthesizing gem-difluorohomoallylic alcohols via the ring-opening of gem-difluorocyclopropane and aerobic oxidation by photo-irradiation in the presence of an organic pigment. Since gem-difluorinated compounds that were prepared by the present method have two olefinic moieties with a different reactivity at the terminal position, we accomplished the synthesis of four types of gem-difluorinated cyclic alkenols via the ring-closing-metathesis (RCM) reaction.

5.
Chem Rec ; 23(8): e202200275, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36631274

RESUMO

The enzymatic reaction is highly respected from an environmentally-friendly point-of-view. Optimization of the reaction media and supporting materials of enzymes must be investigated in parallel with the effort to develop new enzymes. Lipases are frequently used for organic syntheses as synthetic tools even industry because of their acceptance of having a broad range of substrates, stability, and availability. We have investigated the possibility of ILs as both a solvent and activating or stabilization agent of enzymes, in particular, lipase as a model enzyme. ILs allowed recyclable use of a lipase and significant acceleration of transesterification, and also enhanced the stability and reaction activity of a lipase by immobilization through a lyophilization process. We discuss how we enhanced the enzyme capability using the IL engineering focusing on lipase-catalyzed reactions, i. e., realization of the recyclable use of an enzyme, how ILs mediated the enhanced reaction rate, and improved the stability of the enzyme.


Assuntos
Líquidos Iônicos , Lipase , Fenômenos Químicos
6.
J Gen Fam Med ; 23(6): 401-406, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36349208

RESUMO

Background: Dyspnea is a high priority symptom in the emergency department, with heart failure (HF) as one of its leading causes. Recently, the "comet tail sign (CTS)," a pulmonary ultrasonographic sign, has been proposed as an efficacious tool for detecting pulmonary edema. However, to the best of our knowledge, there have been no published data regarding its utility when performed by non-experts, including junior residents. Methods: Between September 2017 and December 2018, patients with dyspnea, who were admitted to the ER, were enrolled. CTS was evaluated by junior residents at the ER. All patients were evaluated by cardiologists independently, and clinical HF was defined as requiring pharmacological intervention by a cardiologist. At the end of this study, we investigated the results of CTS, laboratory data, and available radiological images. Results: A total of 95 patients were enrolled in the current study, wherein 42 patients were treated by cardiologists as those with clinical HF. Our results showed that CTS could identify clinical HF with a sensitivity of 71.4% and a specificity of 81.1%. The sensitivity of CTS against brain natriuretic peptide (BNP) (cut-off value, 100 pg/ml) was calculated at 92.5%. Furthermore, when evaluated together with peripheral edema, CTS identified clinical HF with a sensitivity of 96%. False positives for CTS included bilateral pneumonia, hypoalbuminemia, and interstitial pneumonitis. Conclusions: Our results indicate that CTS is a simple and effective tool for the use of non-experts, including junior residents.

7.
ACS Appl Mater Interfaces ; 14(32): 36890-36901, 2022 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-35880990

RESUMO

Herein, a physical reservoir device that uses faradaic currents generated by redox reactions of metal ions in ionic liquids was developed. Synthetic time-series data consisting of randomly arranged binary number sequences ("1" and "0") were applied as isosceles-triangular voltage pulses with positive and negative voltage heights, respectively, and the effects of the faradaic current on short-term memory and parity-check task accuracies were verified. The current signal for the first half of the triangular voltage-pulse period, which contained a much higher faradaic current component compared to that of the second half of the triangular voltage-pulse period, enabled higher short-term memory task accuracy. Furthermore, when parity-check tasks were performed using a faradaic current generated by asymmetric triangular voltage-pulse levels of 1 and 0, the parity-check task accuracy was approximately eight times higher than that of the symmetric triangular voltage pulse in terms of the correlation coefficient between the output signal and target data. These results demonstrate the advantage of the faradaic current on both the short-term memory characteristics and nonlinear conversion capabilities and are expected to provide guidance for designing and controlling various physical reservoir devices that utilize electrochemical reactions.

8.
J Gastroenterol ; 56(6): 489-526, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33885977

RESUMO

Inflammatory bowel disease (IBD) is a general term for chronic or remitting/relapsing inflammatory diseases of the intestinal tract and generally refers to ulcerative colitis (UC) and Crohn's disease (CD). Since 1950, the number of patients with IBD in Japan has been increasing. The etiology of IBD remains unclear; however, recent research data indicate that the pathophysiology of IBD involves abnormalities in disease susceptibility genes, environmental factors and intestinal bacteria. The elucidation of the mechanism of IBD has facilitated therapeutic development. UC and CD display heterogeneity in inflammatory and symptomatic burden between patients and within individuals over time. Optimal management depends on the understanding and tailoring of evidence-based interventions by physicians. In 2020, seventeen IBD experts of the Japanese Society of Gastroenterology revised the previous guidelines for IBD management published in 2016. This English version was produced and modified based on the existing updated guidelines in Japanese. The Clinical Questions (CQs) of the previous guidelines were completely revised and categorized as follows: Background Questions (BQs), CQs, and Future Research Questions (FRQs). The guideline was composed of a total of 69 questions: 39 BQs, 15 CQs, and 15 FRQs. The overall quality of the evidence for each CQ was determined by assessing it with reference to the Grading of Recommendations Assessment, Development and Evaluation approach, and the strength of the recommendation was determined by the Delphi consensus process. Comprehensive up-to-date guidance for on-site physicians is provided regarding indications for proceeding with the diagnosis and treatment.


Assuntos
Guias como Assunto , Doenças Inflamatórias Intestinais/terapia , Prática Clínica Baseada em Evidências/métodos , Prática Clínica Baseada em Evidências/normas , Humanos , Japão
9.
J Gastroenterol ; 56(4): 303-322, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33620586

RESUMO

The Japanese Society of Gastroenterology (JSGE) revised the third edition of evidence-based clinical practice guidelines for peptic ulcer disease in 2020 and created an English version. The revised guidelines consist of nine items: epidemiology, hemorrhagic gastric and duodenal ulcers, Helicobacter pylori (H. pylori) eradication therapy, non-eradication therapy, drug-induced ulcers, non-H. pylori, and nonsteroidal anti-inflammatory drug (NSAID) ulcers, remnant gastric ulcers, surgical treatment, and conservative therapy for perforation and stenosis. Therapeutic algorithms for the treatment of peptic ulcers differ based on ulcer complications. In patients with NSAID-induced ulcers, NSAIDs are discontinued and anti-ulcer therapy is administered. If NSAIDs cannot be discontinued, the ulcer is treated with proton pump inhibitors (PPIs). Vonoprazan (VPZ) with antibiotics is recommended as the first-line treatment for H. pylori eradication, and PPIs or VPZ with antibiotics is recommended as a second-line therapy. Patients who do not use NSAIDs and are H. pylori negative are considered to have idiopathic peptic ulcers. Algorithms for the prevention of NSAID- and low-dose aspirin (LDA)-related ulcers are presented in this guideline. These algorithms differ based on the concomitant use of LDA or NSAIDs and ulcer history or hemorrhagic ulcer history. In patients with a history of ulcers receiving NSAID therapy, PPIs with or without celecoxib are recommended and the administration of VPZ is suggested for the prevention of ulcer recurrence. In patients with a history of ulcers receiving LDA therapy, PPIs or VPZ are recommended and the administration of a histamine 2-receptor antagonist is suggested for the prevention of ulcer recurrence.


Assuntos
Guias como Assunto/normas , Úlcera Péptica/terapia , Antibacterianos/uso terapêutico , Prática Clínica Baseada em Evidências/métodos , Humanos , Japão , Úlcera Péptica/complicações , Inibidores da Bomba de Prótons/uso terapêutico
10.
Carbohydr Res ; 492: 108018, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32339812

RESUMO

Total synthesis of Myc-IV(C16:0, S) via automated electrochemical assembly has been accomplished. This tetrasaccharide has been studied as a symbiotic signal molecule of Arbuscular Mycorrhiza fungi. We have achieved stereoselective synthesis of a disaccharide building block using the mixed-electrolyte system for electrochemical glycosylation; 2 + 1+1 strategy enables us to access the tetrasaccharide precursor and complete the synthesis Myc-IV(C16:0, S) efficiently.


Assuntos
Automação , Técnicas Eletroquímicas , Micorrizas/química , Configuração de Carboidratos
11.
ChemistryOpen ; 8(7): 869-872, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31309034

RESUMO

Electrochemical glycosylation of a linear oligosaccharide with a protecting-group-free primary hydroxyl group afforded cyclic oligo-saccharides, up to hexasaccharides, in high yields. Precursors of the cyclic oligosaccharides were prepared by automated electro-chemical assembly-a method for the automated electrochemical solution-phase synthesis of oligosaccharides. We demonstrated that electrochemical glycosylation is useful not only for intermolecular glycosylation but also for intramolecular glycosylation to synthesize cyclic oligosaccharides.

12.
J Org Chem ; 84(9): 5440-5449, 2019 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-30929443

RESUMO

The radical-type ring-opening reaction of gem-difluorocyclopropanes and subsequent regioselective monoepoxidation of the products were demonstrated. Introduction of a vinyl or allyl group to the epoxide produced the diene derivatives that were subjected to the ring closing metathesis reaction to furnish the gem-difluoromethylene containing cyclopentene, cycloheptene, and cyclooctene derivatives in good to excellent yields.

13.
Adv Biochem Eng Biotechnol ; 168: 79-104, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-29744541

RESUMO

The use of ionic liquids to replace organic or aqueous solvents in biocatalysis processes has recently received great attention, and much progress has been made in this area; the lipase-catalyzed reactions are the most successful. Recent developments in the application of ionic liquids as solvents in lipase-catalyzed reactions for organic synthesis are reviewed, focusing on the ionic liquid mediated activation method of lipase-catalyzed reactions.


Assuntos
Técnicas de Química Sintética/métodos , Líquidos Iônicos , Lipase , Catálise , Líquidos Iônicos/química , Lipase/metabolismo , Solventes/química
14.
Org Biomol Chem ; 16(33): 6106-6114, 2018 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-30091778

RESUMO

We found that aerobic oxidation took place after the visible light-mediated ring-opening reaction of gem-difluorocyclopropane in the presence of an organic dye and amine to furnish 2,2-difluoro-homoallylic alcohols in good yields.

16.
Adv Mater ; 29(41)2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28885728

RESUMO

Liquid benzoquinone and naphthoquinone having diethylene glycol monomethyl ether groups are designed and synthesized as redox active materials that dissolve supporting electrolytes. The Li-ion batteries based on the liquid quinones using LiBF4 /PC show good performance in terms of voltage, capacity, energy efficiency, and cyclability in both static and flow modes. A battery is constructed without using intentionally added organic solvent, and its high energy density (264 W h L-1 ) demonstrates the potential of solvent-free organic redox flow batteries using liquid active materials.

17.
Carbohydr Res ; 450: 44-48, 2017 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-28869819

RESUMO

We have developed a carbohydrate building block of mannosides based on DFT calculations, electrochemical analysis, and automated solution-phase synthesis. The optimized building block in hand was used to prepare the core trisaccharide of GPI anchor oligosaccharides.


Assuntos
Manosídeos/química , Trissacarídeos/química , Automação , Sequência de Carboidratos , Eletroquímica
18.
Chem Rev ; 117(15): 10567-10607, 2017 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-28745876

RESUMO

Ionic liquids (ILs) have now been acknowledged as reaction media for biotransformations. The first three examples were reported in this field in 2000, and since then, numerous applications have been reported for biocatalytic reactions using ILs. Two topics using ILs for enzymatic reactions have been reviewed from the standpoint of biocatalyst mediating organic synthesis; the first is "Biocatalysis in Ionic Liquids" which includes various types of biocatalytic reactions in ILs (section 2): (1) recent examples of lipase-mediated reactions using ILs as reaction media for biodiesel oil production and for sugar ester production, (2) oxidase-catalyzed reactions in ILs, (3) laccase-catalyzed reactions, (4) peroxidase-catalyzed reactions, (4) cytochrome-mediated reactions, (5) microbe-mediated hydrations, (6) protease-catalyzed reactions, (8) whole cell mediated asymmetric reduction of ketones, (10) acylase-catalyzed reactions, (11) glycosylation or cellulase-mediated hydrolysis of polysaccharides, (12) hydroxynitrile lyase-catalyzed reaction, (13) fluorinase or haloalkane dehydrogenase-catalyzed reaction, (14) luciferase-catalyzed reactions, and (15) biocatalytic promiscuity of enzymatic reactions for organic synthesis using ILs. The second is "Enzymes Activated by Ionic Liquids for Organic Synthesis", particularly describing the finding story of activation of lipases by the coating with a PEG-substituted IL (section 3). The author's opinion toward "Future Perspectives of Using ILs for Enzymatic Reactions" has also been discussed in section 4.


Assuntos
Enzimas/metabolismo , Líquidos Iônicos/metabolismo , Compostos Orgânicos/metabolismo , Biocatálise , Enzimas/química , Líquidos Iônicos/química , Estrutura Molecular , Compostos Orgânicos/química
19.
Sci Rep ; 7(1): 5079, 2017 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-28698635

RESUMO

Local anesthetics (LAs) inhibit endoplasmic reticulum-associated protein degradation, however the mechanisms remain elusive. Here, we show that the clinically used LAs pilsicainide and lidocaine bind directly to the 20S proteasome and inhibit its activity. Molecular dynamic calculation indicated that these LAs were bound to the ß5 subunit of the 20S proteasome, and not to the other active subunits, ß1 and ß2. Consistently, pilsicainide inhibited only chymotrypsin-like activity, whereas it did not inhibit the caspase-like and trypsin-like activities. In addition, we confirmed that the aromatic ring of these LAs was critical for inhibiting the proteasome. These LAs stabilized p53 and suppressed proliferation of p53-positive but not of p53-negative cancer cells.


Assuntos
Anestésicos Locais/farmacologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Inibidores de Proteassoma/farmacologia , Animais , Bovinos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Humanos , Leupeptinas/farmacologia , Lidocaína/análogos & derivados , Lidocaína/farmacologia , Simulação de Acoplamento Molecular , Estabilidade Proteica/efeitos dos fármacos
20.
Beilstein J Org Chem ; 13: 919-924, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28684973

RESUMO

The total synthesis of TMG-chitotriomycin using an automated electrochemical synthesizer for the assembly of carbohydrate building blocks is demonstrated. We have successfully prepared a precursor of TMG-chitotriomycin, which is a structurally-pure tetrasaccharide with typical protecting groups, through the methodology of automated electrochemical solution-phase synthesis developed by us. The synthesis of structurally well-defined TMG-chitotriomycin has been accomplished in 10-steps from a disaccharide building block.

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