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1.
J Org Chem ; 89(3): 1777-1783, 2024 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-38163754

RESUMO

Unsymmetrical H-phosphonates were synthesized by a rapid (<15 s) and mild (20 °C) process in a microflow reactor as the first example of the sequential direct substitution of the chlorine atoms in PCl3 with alkoxyl/aryloxy groups using equivalent amounts of PCl3 and alcohols. The optimal base concentration differed in each step, presumably attributed to differences in the Brønsted basicity of the electrophilic intermediates. Phosphite hydrolysis was observed, and the structure-hydrolysis relationship was quantitatively evaluated.

2.
Anal Methods ; 15(25): 3019-3025, 2023 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-37226525

RESUMO

The development of high-throughput screening methods for microorganisms is desired because microorganisms are useful and sustainable resources with which valuable substances utilized in various industries can be produced. Micro-space-based methods are the best candidates for the efficient screening of microorganisms owing to their low reagent consumption and compact integration. In this study, we developed a picoliter-sized incubator array for quantitative and labeling-free evaluation of the growth process of Escherichia coli (E. coli) by autofluorescence. Because the array with 8464 incubators is able to compartmentalize single E. coli individually utilizing the Poisson distribution, the array can evaluate 100 single E. coli simultaneously. Our incubator array not only realized the high-throughput screening of microorganisms, but also provided an analytical tool for assessing individual differences in E. coli.


Assuntos
Escherichia coli , Incubadoras
3.
Intern Med ; 62(22): 3291-3298, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-36927976

RESUMO

Objective Chronic pulmonary aspergillosis (CPA) is an important complication of nontuberculous mycobacterial pulmonary disease (NTM-PD). However, its diagnosis is challenging, as both CPA and NTM-PD present as chronic cavitary disease. The present study evaluated the impact of CPA on the survival of patients with NTM-PD and revealed the key computed tomography findings for a prompt diagnosis. Methods We retrospectively reviewed patients newly diagnosed with NTM-PD in Tenri Hospital (Tenri City, Nara Prefecture, Japan) between January 2009 and March 2018; the patients were followed up until May 2021. Clinical and radiological characteristics were assessed, and patients with CPA were identified. Results A total of 611 patients were diagnosed with NTM-PD. Among them, 38 (6.2%), 102 (17%), and 471 (77%) patients were diagnosed with NTM-PD with CPA, cavitary NTM-PD without CPA, and non-cavitary NTM-PD without CPA, respectively. The 5-year survival rate of the NTM-PD with CPA group (42.8%; 95% confidence interval: 28.7-64.0%) was lower than that of the cavitary NTM-PD without CPA group (74.4%; 95% confidence interval: 65.4-84.6%). A multivariate analysis revealed that fungal balls and cavities with adjacent extrapleural fat were significant predictive factors for NTM-PD with CPA. Conclusion NTM-PD with CPA patients exhibited a worse prognosis than cavitary NTM-PD without CPA patients. Therefore, an unerring diagnosis of CPA is essential for managing patients with NTM-PD. Computed tomography findings, such as fungal balls and cavities with adjacent extrapleural fat, may be valuable diagnostic clues when CPA is suspected in patients with NTM-PD.


Assuntos
Pneumopatias , Infecções por Mycobacterium não Tuberculosas , Aspergilose Pulmonar , Humanos , Estudos Retrospectivos , Infecções por Mycobacterium não Tuberculosas/complicações , Infecções por Mycobacterium não Tuberculosas/diagnóstico por imagem , Pulmão , Aspergilose Pulmonar/complicações , Aspergilose Pulmonar/diagnóstico por imagem , Doença Crônica , Tomografia Computadorizada por Raios X , Micobactérias não Tuberculosas , Pneumopatias/complicações
4.
Polymers (Basel) ; 15(2)2023 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-36679217

RESUMO

Recently, organic polysulfides have been synthesized as cathode active materials exceeding the battery performance of sulfur. However, the conventional organic polysulfides have exhibited capacities lower than the theoretical capacity of sulfur because the π-organic moieties do not conjugate with the sulfur chains. In this work, the organopolysulfides, synthesized via inverse vulcanization using disulfide compounds, exhibited higher capacities equal to the theoretical capacity of sulfur because of enhanced electronic conductivity based on the conjugation between organic moieties and sulfur chains. Furthermore, the organopolysulfide including 1,3-dhitiol-2-thione moiety exhibited the highest capacity because of the enhanced electronic conductivity. This finding will pave the way to develop next-generation rechargeable batteries.

5.
J Biotechnol ; 358: 46-54, 2022 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-36041515

RESUMO

The oleaginous yeast Lipomyces starkeyi is expected to be a new lipid source since this microorganism is capable of accumulating more than 85% lipid per dry cell weight. For effective utilization of oleaginous yeast, mutants with improved lipid production compared to the wild-type have been screened by methods such as single-cell sorting and Percoll density gradient centrifugation. Because these methods need to reculture all mutated oleaginous yeasts together in a flask, it is difficult to evaluate the growth of each individual mutant. Thus, screening for the slow-growing mutants with high-throughput has never been performed by conventional methods. In this study, we developed a high-throughput method using gel microdroplets (GMD). With this method, the growth and lipid production of L. starkeyi can be evaluated simultaneously. L. starkeyi grew in GMD and the size of these microcolonies was evaluated by scattered light. Finally, a mutant with a 10-fold delay in growth compared to the wild-type was obtained. Analysis of genetic information in this mutant could reveal valuable information about critical genes involved in the growth of these microorganisms, which could then be utilized further.


Assuntos
Ensaios de Triagem em Larga Escala , Lipomyces , Lipídeos , Lipomyces/genética , Leveduras
6.
Sci Rep ; 12(1): 10936, 2022 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-35768480

RESUMO

We present a dry pick-and-flip assembly technique for angle-resolved photoemission spectroscopy (ARPES) of van der Waals heterostructures. By combining Elvacite2552C acrylic resin and 1-ethyl-3-methylimidazolium ionic liquid, we prepared polymers with glass transition temperatures (Tg) ranging from 37 to 100 â„ƒ. The adhesion of the polymer to the 2D crystals was enhanced at [Formula: see text]. By utilizing the difference in [Formula: see text], a 2D heterostructure can be transferred from a high-[Formula: see text] polymer to a lower-[Formula: see text] polymer, which enables flipping its surface upside down. This process is suitable for assembling heterostructures for ARPES, where the top capping layer should be monolayer graphene. The laser-based micro-focused ARPES measurements of 5-layer WTe2, 3-layer MoTe2, 2-layer WTe2/few-layer Cr2Ge2Te6, and twisted double bilayer WTe2 demonstrate that this process can be utilized as a versatile sample fabrication method for investigating the energy spectra of 2D heterostructures.

7.
Anal Chem ; 94(5): 2416-2424, 2022 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-34963280

RESUMO

Droplet-based microfluidic systems are a powerful tool for biological assays with high throughput. Water-in-oil droplets (WODLs) are typically used in droplet-based microfluidic systems to culture microorganisms and perform enzyme assays. However, because of the oil surrounding the nanoliter and picoliter volumes of WODLs, availability of suitable substrates is limited. For instance, although 7-amino-4-methylcoumarin (AMC) is commonly used as a fluorescent probe of the substrate to detect peptidase activity, AMC leaks from WODLs to the oil phase due to its high hydrophobicity. Thus, AMC substrates cannot be used in droplet-based microfluidic systems with WODLs. In this study, we developed a peptidase substrate consisting of a dipeptide and 7-aminocoumarin-4-acetic acid (ACA), an AMC-derived fluorogenic compound. ACA was retained in the WODL for more than 7 days, and the dipeptidyl ACA substrate detected dipeptidyl peptidase (DPP) activity in the WODL. Compared to AMC substrates, the substrate specificity constants of DPPs for ACA substrates increased up to 4.7-fold. Fluorescence-activated droplet sorting made high-throughput screening of microorganisms based on DPP activity using the dipeptidyl ACA substrate possible. Since ACA could be applied to various substrates as a fluorescent probe, detectable microbial enzyme activities for droplet-based microfluidic systems can be largely expanded.


Assuntos
Corantes Fluorescentes , Água , Ácido Acético , Cumarínicos , Dipeptidil Peptidases e Tripeptidil Peptidases , Corantes Fluorescentes/química
8.
Vet Res ; 51(1): 119, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32933583

RESUMO

Lesions of adiaspiromycosis, a respiratory disease affecting wild animals, have been found mainly in dead mammals and free-living mammals captured for surveillance. No report has described an investigation of adiaspore formation progress in the lung. After establishing an experimental mouse model of intratracheal adiaspiromycosis infection with the causative agent Emmonsia crescens, we observed adiaspore development. The spores grew and reached a plateau of growth at 70 days post-infection. The median adiaspore diameter showed a plateau of around 40 µm. The characteristic three-layer cell-wall structure of adiaspores was observed in the lung at 70 days post-infection. We examined infection with a few spores, which revealed that adiaspores in the mouse lung progressed from intratracheal infection of at least 400 spores. Moreover, we developed adiaspores in vitro by culture in fetal bovine serum. Although most spores broke, some large spores were intact. They reached about 50 µm diameter. Thick cell walls and dense granules were found as common points between in vitro adiaspores and in vivo adiaspores. These models are expected to be useful for additional investigations of E. crescens adiaspores and adiaspiromycosis.


Assuntos
Chrysosporium/fisiologia , Pneumopatias Fúngicas/veterinária , Esporos Fúngicos/fisiologia , Animais , Chrysosporium/crescimento & desenvolvimento , Chrysosporium/ultraestrutura , Modelos Animais de Doenças , Pneumopatias Fúngicas/microbiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microscopia/veterinária , Microscopia Eletrônica de Transmissão/veterinária , Esporos Fúngicos/crescimento & desenvolvimento , Esporos Fúngicos/ultraestrutura
9.
Biosci Biotechnol Biochem ; 83(5): 952-959, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30741106

RESUMO

Ellagic acid has been shown to improve cholesterol metabolism in animal studies, but the molecular mechanisms underlying this function have not been fully understood. We performed DNA microarray analysis to elucidate the effects of ellagic acid on cholesterol metabolism in HepG2 hepatocytes. This revealed that the expression levels of several genes related to cholesterol metabolism, including the low-density lipoprotein receptor (LDLR), were changed by ellagic acid treatment. Using a real-time PCR and immunoblot we confirmed that ellagic acid treatment up-regulated mRNA and protein expression level of the LDLR. Moreover, In the presence of 25 µM ellagic acid, extracellular apoB protein and MTP mRNA levels were significantly decreased. These findings indicate that ellagic acid improves cholesterol metabolism through the up-regulation of LDLR, down-regulation of MTP mRNA and reduces extracellular apoB levels. The ellagic acid-induced up-regulation of LDLR occurred via the extracellular signal-regulated kinase (ERK) signaling pathway in HepG2 hepatocytes. Abbreviations: LDLR: low-density lipoprotein receptor; apoB: apolipoprotein B; PKC: diacylglycerol-protein kinase C; MAPK: mitogen-activated protein kinase; ERK: p42/44 extracellular signal-regulated kinase; JNK: c-Jun N-terminal kinase; VLDLR: very low density lipoprotein receptor; PPARδ: peroxisome proliferator-activated receptor δ; SREBPs: sterol regulatory element-binding proteins; MTP: microsomal triacylglycerol transfer protein; LPDS: lipoprotein-deficient serum.


Assuntos
Colesterol/metabolismo , Ácido Elágico/farmacologia , RNA Mensageiro/genética , Apolipoproteínas B/metabolismo , Linhagem Celular Tumoral , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Meia-Vida , Células Hep G2 , Humanos , Análise de Sequência com Séries de Oligonucleotídeos , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Receptores de LDL/genética , Receptores de LDL/metabolismo , Transcrição Gênica , Regulação para Cima/efeitos dos fármacos
10.
Chem Sci ; 9(15): 3754-3758, 2018 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-29780507

RESUMO

Thousands of terpenes have been identified to date. However, only two classes of enzymes are known to be involved in their biosynthesis, and each class has characteristic amino-acid motifs. We recently identified a novel large-terpene (C25/C30/C35) synthase, which shares no motifs with known enzymes. To elucidate the molecular mechanism of this enzyme, we determined the crystal structure of a large-ß-prene synthase from B. alcalophilus (BalTS). Surprisingly, the overall structure of BalTS is similar to that of the α-domain of class I terpene synthases although their primary structures are totally different from each other. Two novel aspartate-rich motifs, DYLDNLxD and DY(F,L,W)IDxxED, are identified, and mutations of any one of the aspartates eliminate its enzymatic activity. The present work leads us to propose a new subclass of terpene synthases, class IB, which is probably responsible for large-terpene biosynthesis.

11.
Biochem Biophys Res Commun ; 444(3): 401-5, 2014 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-24472543

RESUMO

Sulphur-containing amino acids regulate plasma cholesterol levels in animals and humans. However, their mechanism of action remains unclear. Low-density lipoprotein receptor (LDLR) plays an important role in cholesterol metabolism. We therefore investigated the effects of sulphur-containing amino acids on the expression of LDLR in hepatocytes. HepG2 cells were cultured in Dulbecco's Modified Eagle's Medium with or without sulphur-containing amino acids and cysteine-containing compounds. We found that L-cysteine increased LDLR mRNA and enhanced LDLR gene promoter activity through the extracellular-signal-related kinase and p38 mitogen-activated protein kinase signalling pathways in HepG2 cells. Moreover, we observed that L-cysteine stimulated the release of transforming growth factor-alpha (TGF-α) and that TGF-α increased the LDLR mRNA levels. This study provides a report of the L-cysteine mediated up-regulation of the LDLR expression via TGF-α signalling pathway. Our findings provide insights into cholesterol homeostasis and amino acid signalling.


Assuntos
Cisteína/farmacologia , Receptores de LDL/metabolismo , Transdução de Sinais , Fator de Crescimento Transformador alfa/metabolismo , Regulação para Cima/efeitos dos fármacos , Colesterol/metabolismo , Ensaio de Imunoadsorção Enzimática , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Células Hep G2 , Humanos , Regiões Promotoras Genéticas , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Fator de Crescimento Transformador alfa/genética , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
12.
Opt Lett ; 36(18): 3578-80, 2011 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-21931396

RESUMO

Polarization-independent refractive index (RI) modulation can be achieved in blue phase (BP) liquid crystals (LCs) by applying an electric field parallel to the direction of light transmission. One of the problems limiting the achievable tuning range is the field-induced phase transition to the cholesteric phase, which is birefringent and chiral. Here we report the RI modulation capabilities of gold nanoparticle-doped BPs I and II, and we show that field-induced BP-cholesteric transition is suppressed in nanoparticle-doped BP II. Because the LC remains optically isotropic even at high applied voltages, a larger RI tuning range can be achieved.

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