Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.023
Filtrar
1.
BMC Biol ; 20(1): 110, 2022 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-35549721

RESUMO

BACKGROUND: Mosquitoes locate a human host by integrating various sensory cues including odor, thermo, and vision. However, their innate light preference and its genetic basis that may predict the spatial distribution of mosquitoes, a prerequisite to encounter a potential host and initiate host-seeking behaviors, remains elusive. RESULTS: Here, we first studied mosquito visual features and surprisingly uncovered that both diurnal (Aedes aegypti and Aedes albopictus) and nocturnal (Culex quinquefasciatus) mosquitoes significantly avoided stronger light when given choices. With consistent results from multiple assays, we found that such negative phototaxis maintained throughout development to adult stages. Notably, female mosquitoes significantly preferred to bite hosts in a shaded versus illuminated area. Furthermore, silencing Opsin1, a G protein-coupled receptor that is most enriched in compound eyes, abolished light-evoked avoidance behavior of Aedes albopictus and attenuated photonegative behavior in Aedes aegypti. Finally, we found that field-collected Aedes albopictus also prefers darker area in an Opsin1-dependent manner. CONCLUSIONS: This study reveals that mosquitoes consistently prefer darker environment and identifies the first example of a visual molecule that modulates mosquito photobehavior.

2.
J Microsc ; 2022 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-35570411

RESUMO

Electron energy-loss spectroscopy (EELS) is widely applied combining with transmission electron microscopes with high spatial resolution, but its interpretation is a challenging task. One of the reasons is that the factors affecting EELS are very complicated. In this paper, we focus on the several factors involved in density functional theory (DFT) calculations. The sensitivity of calculated energy-loss near-edge structure (ELNES) to spin order, pressure, and on-site Coulomb energy U has been discussed. Since EELS technique detects the local environment of atoms, the influence of spin order cannot be ignored. The chemical shifts and peak intensity of ELNES are also closely related to corresponding pressure. The correlation effects are very important for transition metal compounds and play a key role in EELS simulations. An overview of the effects of these factors on the ELNES is presented with the help of Wien2k code. The antiferromagnetic order results in the decreasing of intensities of related peaks and the moving of the peaks to high energy loss. The decreasing of lattice parameters causes the ELNES peaks to shift to high energy loss, and the peak shifts at the higher energy loss are more significant. The increase of correlation effect leads to the ELNES peaks to shift to high energy loss accompanied by the increase of the relative intensity of the peaks which locate at higher energy loss. Our work helps to understand how these factors affect EELS and to explain and predict the experimental EELS spectra. Through the discussion of these factors, we propose that some factors could not be ignored in EELS simulations. This article is protected by copyright. All rights reserved.

3.
Acta Biochim Biophys Sin (Shanghai) ; 54(4): 537-547, 2022 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-35607964

RESUMO

Glucosylsucroses are potentially useful as additives in cosmetic and pharmaceutical formulations. Although enzymatic synthesis of glucosylsucroses is the most efficient method for their production, the key enzyme that produces them has remained unknown. Here, we report that glucosylsucrose synthase from (TeGSS) catalyzes the synthesis of glucosylsucrose using sucrose and UDP-glucose as substrates. These saccharides are homologous to glucosylsucroses produced by sp. PCC 7120 (referred to as protein alr1000). When the ratio of UDP-glucose to sucrose is relatively high, TeGSS from cyanobacteria can hydrolyze excess UDP-glucose to UDP and glucose, indicating that sucrose provides a feedback mechanism for the control of glucosylsucrose synthesis. In the present study, we solved the crystal structure of TeGSS bound to UDP and sucrose. Our structure shows that the catalytic site contains a circular region that may allow glucosylsucroses with a right-hand helical structure to enter the catalytic site. Because active site residues Tyr18 and Arg179 are proximal to UDP and sucrose, we mutate these residues (., Y18F and R179A) and show that they exhibit very low activity, supporting their role as catalytic groups. Overall, our study provides insight into the catalytic mechanism of TeGSS.

4.
Quant Imaging Med Surg ; 12(5): 2709-2720, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35502374

RESUMO

Background: Angiographic computed tomography (CT) is useful in various medical contexts, but little research has been presented regarding the application of cone beam CT (CBCT) in airway stenting. This study set out to evaluate the clinical feasibility of using CBCT in airway stent placement in a single-center retrospective cohort. Methods: A total of 228 patients with stenosis or fistula diseases were treated with metallic airway stents in the First Affiliated Hospital of Zhengzhou University from January 1, 2015, to December 31, 2018. Of them, 128 patients underwent fluoroscopy-guided airway stenting. CBCT scanning was performed on the other 100 patients during and after treatment, and their images were compared with those from postoperative multidetector CT (MDCT). The outcomes and complications in the CBCT-guided and fluoroscopy-guided groups were also assessed via Pearson's χ2 test or Fisher's exact test. Results: Tracheal stenting was performed successfully on the first attempt for 90 patients in the CBCT-guided group and 123 patients in the fluoroscopy-guided group. The mean measured diameters of the central airway in the CBCT images and MDCT images were 18.2±2.81 and 19.0±2.33 mm, respectively, and the mean lengths were 58.7±16.82 and 58.5±17.06 mm, respectively. In the CBCT-guided group and the fluoroscopy-guided group, the mean scores for visibility of the distal bronchus were 3.7±0.49 and 3.9±0.34, respectively; the mean scores for the pulmonary parenchyma were 3.3±0.71 and 3.9±0.31, respectively; and the mean scores for the airway above the upper stent graft were 1.8±0.41 and 4.0±0.20, respectively. Two of the three anatomical areas were reproduced in a diagnostically relevant way. The major complications rate was 7% and 19% in the CBCT-guided and fluoroscopy-guided groups, respectively. Conclusions: CBCT produces images with sufficient quality to replace MDCT as a reasonable control measure after stent implantation, and its use during surgery reduces complications relating to airway stent placement.

5.
Artigo em Inglês | MEDLINE | ID: mdl-35510688

RESUMO

Organic room-temperature long-persistent luminescent materials are promising light-emitting materials for encryption, architectural decoration, organic solar cells, and biomedical applications. However, their unstable structures and thermal- and humidity-induced emission quenching have greatly limited their utility and reliability. Here, we report a metal-free nonconjugated copolymer that possesses stable photoluminescence at both high temperature and humidity. The room temperature long-persistent luminescence (LPL) of this copolymer lasts for more than 15 s and can be recovered in high humidity conditions by heating to remove moisture. Copolymer LPL can be achieved with various excitation wavelengths, ranging from ultraviolet to near-infrared, and the LPL color can be adjusted accordingly. The high initial LPL intensity and ultrafast filling time of the copolymer makes it suitable for low flicker alternating current-driven light-emitting diodes (AC-LEDs).

6.
Int J Mol Sci ; 23(9)2022 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-35563603

RESUMO

Glyoxalase I (GLYI) is a key enzyme in the pathway of the glyoxalase system that degrades the toxic substance methylglyoxal, which plays a crucial part in plant growth, development, and stress response. A total of 19 GLYI genes were identified from the cassava genome, which distributed randomly on 11 chromosomes. These genes were named MeGLYI-1-19 and were systematically characterized. Transcriptome data analysis showed that MeGLYIs gene expression is tissue-specific, and MeGLYI-13 is the dominant gene expressed in young tissues, while MeGLYI-19 is the dominant gene expressed in mature tissues and organs. qRT-PCR analysis showed that MeGLYI-13 is upregulated under 2 h excess iron stress, but downregulated under 6, 12, and 20 h iron stress. Overexpression of MeGLYI-13 enhanced the growth ability of transgenic yeast under iron stress. The root growth of transgenic Arabidopsis seedlings was less inhibited by iron toxicity than that of the wild type (WT). Potted transgenic Arabidopsis blossomed and podded under iron stress, but flowering of the WT was significantly delayed. The GLYI activity in transgenic Arabidopsis was improved under both non-iron stress and iron stress conditions compared to the WT. The SOD activity in transgenic plants was increased under iron stress, while the POD and CAT activity and MDA content were decreased compared to that in the WT. These results provide a basis for the selection of candidate genes for iron toxicity tolerance in cassava, and lay a theoretical foundation for further studies on the functions of these MeGLYI genes.

7.
Eur J Med Chem ; 237: 114407, 2022 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-35512565

RESUMO

Acetylation of histone lysine residues by histone acetyltransferase (HAT) p300 and its paralog CBP play important roles in gene regulation in health and diseases. The HAT domain of p300/CBP has been found to be a potential drug target for cancer. Compound screening followed by structure-activity relationship studies yielded a novel series of 1,4-pyrazine-containing inhibitors of p300/CBP HAT with their IC50s as low as 1.4 µM. Enzyme kinetics and other studies support the most potent compound 29 is a competitive inhibitor of p300 HAT against the substrate histone. It exhibited a high selectivity for p300 and CBP, with negligible activity on other classes of HATs in human. Compound 29 inhibited cellular acetylation of several histone lysine residues and showed strong activity against proliferation of a panel of solid and blood cancer cells. These results indicate it is a novel pharmacological lead for drug development targeting these cancers as well as a useful chemical probe for biological studies of p300/CBP.

8.
J Healthc Eng ; 2022: 1414723, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35368931

RESUMO

Pneumothorax is a common injury in disaster rescue, traffic accidents, and war trauma environments and requires early diagnosis and treatment. The commonly used X-ray, CT, and other diagnostic instruments are not suitable for rescue sites due to their large size, heavy weight, and difficulty in transportation. Ultrasound equipment is easy to carry and suitable for rescue environments. However, ultrasound images are noisy, have low resolution, and are difficult to get started, which affects the efficiency of diagnosis. This paper studies the effect of lung ultrasound image recognition and classification based on compressed sensing and BP neural network. We use ultrasound equipment to build a lung simulation model, collect five typical features of lung ultrasound images in M-mode, and build a dataset. Using compressed sensing theory, we design sparse matrix and observation matrix and perform data compression on the image data in the dataset to obtain observation values. We design a BP neural network, input the observations into the network for training, and compare it with the commonly used VGG16 network. The method proposed in this paper has higher recognition accuracy and significantly fewer parameters than VGG16, so it is suitable for use in embedded devices.


Assuntos
Compressão de Dados , Redes Neurais de Computação , Humanos , Pulmão/diagnóstico por imagem , Tórax , Ultrassonografia/métodos
9.
Molecules ; 27(7)2022 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-35408641

RESUMO

To develop an appropriate sampling strategy to assess the intrauterine exposure to dechlorane plus (DP), we investigated DP levels in sequential maternal blood samples collected in three trimesters of pregnancy, respectively, from women living in Taizhou. The median concentration of DPs (sum of syn-DP and anti-DP) in all samples was 30.5 pg g-1 wet-weight and 5.01 ng g-1 lipid-adjusted weight, respectively. The trimester-related DP concentrations were consistently strongly correlated (p < 0.01), indicating that a single measurement of DP levels could represent intrauterine exposure without sampling from the same female repeatedly; however, the wet-weight levels significantly increased across trimesters (p < 0.05), while the lipid-adjusted levels did not significantly vary. Notably, whether lipid-adjusted weight or wet-weight levels, the variation extent of DP across trimesters was found to be less than 41%, and those for other persistent organic pollutants (POPs) reported in the literature were also limited to 100%. The limitation in variation extents indicated that, regardless of the time of blood collection during pregnancy and how the levels were expressed, a single measurement could be extended to screen for exposure risk if necessary. Our study provides different strategies for sampling the maternal blood to serve the requirement for assessment of in utero exposure to DP.


Assuntos
Retardadores de Chama , Hidrocarbonetos Clorados , Compostos Policíclicos , China , Monitoramento Ambiental , Feminino , Retardadores de Chama/análise , Humanos , Hidrocarbonetos Clorados/análise , Lipídeos , Gravidez , Gestantes
10.
Ann Transl Med ; 10(6): 368, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35434035

RESUMO

Background and Objective: Ferroptosis is a recently discovered form of cell death which differs from other forms of cell death in terms of morphology, biochemistry, and regulatory mechanisms. Ferroptosis is regulated by a complex system and the precise molecular mechanisms are still being elucidated. Over the past few years, extensive research has revealed that the essence of ferroptosis is iron-dependent accumulation of lipid hydroperoxides induced by oxidative stress, and the System Xc-glutathione (GSH)-glutathione peroxidase 4 (GPX4) pathway is the main ferroptosis prevention system. Meanwhile, other antioxidant systems have also been implicated in regulating ferroptosis, including the transsulfuration pathway, mevalonate pathway, ferroptosis inhibitory protein 1 (FSP1)-Coenzyme Q10 (CoQ10) pathway, dihydroorotate dehydrogenase (DHODH)-dihydroubiquione (CoQH2) pathway, and GTP cyclohydrolase-1 (GCH1)-tetrahydrobiopterin (BH4) pathway. This article reviews the molecular mechanisms of ferroptosis and its critical role in antioxidant systems, aiming to reveal that antioxidation is an important method of inhibiting ferroptosis and to provide a new direction for the treatment of ferroptosis-related diseases. Methods: We searched all original papers and reviews about the molecular mechanisms of ferroptosis in antioxidant systems using PubMed to November 2021. The search terms used included: 'ferroptosis', 'ferroptosis inducers', 'ferroptosis inhibitors', 'ferroptosis and GSH', 'ferroptosis and GPX4', 'ferroptosis and System Xc-', 'SLC7A11', 'P53', 'NRF2 and ferroptosis', 'iron metabolism', 'lipid peroxidation', 'antioxidant systems', 'transsulfuration pathway', 'mevalonate pathway', 'FSP1-CoQ10', 'DHODH-CoQH2', and 'GCH1-BH4'. Key Content and Findings: We first introduced the origin of ferroptosis and its common inhibitors and inducers. Next, we discussed the molecular mechanisms of ferroptosis and its role in antioxidant systems in existing studies. Finally, we briefly summarized the relationship between ferroptosis and diseases. It reveals that antioxidation is an important method of inhibiting ferroptosis. Conclusions: This review discusses the recent rapid progress in the understanding of the molecular mechanisms of ferroptosis and its role in several antioxidant systems.

11.
ACS Appl Mater Interfaces ; 14(15): 17153-17163, 2022 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-35394283

RESUMO

Tumor microenvironment (TME)-responsive chemodynamic therapy (CDT) mediated by nanozymes has been extensively studied both experimentally and theoretically, but the low catalytic efficiency due to insufficient H2O2 in the TME and the poor biodegradability of the nanozymes are still main challenges for clinical translation of nanozymes. Herein, we designed a H2O2 self-supplying nanozyme bearing glucose oxidase (GOX) and polyethyleneimine based on a degradable iron-doped phosphate-based glass (FePBG) nanomimic (FePBG@GOX), which can convert endogenous glucose into toxic hydroxyl radicals. The GOX loaded on the nanozyme can effectively consume glucose in tumor cells to produce a large amount of H2O2 to make up for the lack of H2O2 in the TME. Thereafter, enormous hydroxyl radicals, based on a Fenton reaction of FePBG without any exogenous H2O2, are generated to induce severe apoptosis of tumor cells. The nanozyme exhibits enhanced in vitro cytotoxicity in a high-glucose medium than in a low-glucose medium, illustrating sufficient generation of H2O2 by GOX. The excellent in vivo antitumor efficacy is manifested by a high tumor growth inhibition ratio of 94.65% in model mice. Excellent intrinsic biodegradability owing to its phosphate-based glass nature is a remarkable advantage of the prepared FePBG nanozyme over most other reported nanozymes. Big concerns about side effects caused by long-time residence in living organisms are eliminated since it degrades not only in an acid medium but also in a neutral physiological environment. Therefore, this novel strategy of the TME-responsive H2O2 self-supplying nanozyme based on an endogenous cascade catalytic reaction opens up an avenue for designing degradable nanozymes in CDT.


Assuntos
Peróxido de Hidrogênio , Neoplasias , Animais , Linhagem Celular Tumoral , Glucose , Glucose Oxidase/metabolismo , Peróxido de Hidrogênio/metabolismo , Radical Hidroxila , Ferro , Camundongos , Neoplasias/tratamento farmacológico , Fosfatos , Microambiente Tumoral
12.
Plants (Basel) ; 11(7)2022 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-35406926

RESUMO

Alkaline/neutral invertase (A/N-INV) is an invertase that irreversibly decomposes sucrose into fructose as well as glucose and plays a role in plant growth and development, starch synthesis, abiotic stress, and other plant-life activities. Cassava is an economically important starch crop in tropical regions. During the development of cassava tuber roots, A/N-INV activity is relatively high, which indicates that it may participate in sucrose metabolism and starch synthesis. In this study, MeNINV1 was confirmed to function as invertase to catalyze sucrose decomposition in yeast. The optimal enzymatic properties of MeNINV1 were a pH of 6.5, a reaction temperature of 40 °C, and sucrose as its specific catalytic substrate. VB6, Zn2+, and Pb2+ at low concentrations as well as EDTA, DTT, Tris, Mg2+, and fructose inhibited A/N-INV enzymic activity. In cassava, the MeNINV1 gene was mainly expressed in the fibrous roots and the tuber root phloem, and its expression decreased as the tuber root grew. MeNINV1 was confirmed to localize in chloroplasts. In Arabidopsis, MeNINV1-overexpressing Arabidopsis had higher A/N-INV activity, and the increased glucose, fructose, and starch content in the leaves promoted plant growth and delayed flowering time but did not change its resistance to abiotic stress. Our results provide new insights into the biological function of MeNINV1.

13.
Nat Commun ; 13(1): 1856, 2022 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-35387980

RESUMO

The prime editors (PEs) have shown great promise for precise genome modification. However, their suboptimal efficiencies present a significant technical challenge. Here, by appending a viral exoribonuclease-resistant RNA motif (xrRNA) to the 3'-extended portion of pegRNAs for their increased resistance against degradation, we develop an upgraded PE platform (xrPE) with substantially enhanced editing efficiencies in multiple cell lines. A pan-target average enhancement of up to 3.1-, 4.5- and 2.5-fold in given cell types is observed for base conversions, small deletions, and small insertions, respectively. Additionally, xrPE exhibits comparable edit:indel ratios and similarly minimal off-target editing as the canonical PE3. Of note, parallel comparison of xrPE to the most recently developed epegRNA-based PE system shows their largely equivalent editing performances. Our study establishes a highly adaptable platform of improved PE that shall have broad implications.


Assuntos
Sistemas CRISPR-Cas , Edição de Genes , Sistemas CRISPR-Cas/genética , Linhagem Celular , Genoma
14.
Nat Commun ; 13(1): 2054, 2022 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-35440119

RESUMO

The resolution of chromatin conformation capture technologies keeps increasing, and the recent nucleosome resolution chromatin contact maps allow us to explore how fine-scale 3D chromatin organization is related to epigenomic states in human cells. Using publicly available Micro-C datasets, we develop a deep learning model, CAESAR, to learn a mapping function from epigenomic features to 3D chromatin organization. The model accurately predicts fine-scale structures, such as short-range chromatin loops and stripes, that Hi-C fails to detect. With existing epigenomic datasets from ENCODE and Roadmap Epigenomics Project, we successfully impute high-resolution 3D chromatin contact maps for 91 human tissues and cell lines. In the imputed high-resolution contact maps, we identify the spatial interactions between genes and their experimentally validated regulatory elements, demonstrating CAESAR's potential in coupling transcriptional regulation with 3D chromatin organization at high resolution.


Assuntos
Cromatina , Epigenômica , Cromatina/genética , Cromossomos , Regulação da Expressão Gênica , Humanos , Sequências Reguladoras de Ácido Nucleico
15.
Foods ; 11(8)2022 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-35454720

RESUMO

In this study, the physicochemical properties of indica (IWR) and japonica (JWR) waxy rice were investigated to find the critical factor that differentiates the pasting behaviors among the two cultivars. The results showed that the peak viscosity of 5 IWR flours was in the range of 1242 to 1371 cP, which was significantly higher than 4 JWR flours (667 to 904 cP). Correlation analysis indicated that all pasting parameters were not correlated (p < 0.05) with physicochemical properties of rice flours and the fine structure of isolated starches. The pasting profiles of IWRs were still significantly higher than those of JWRs after removing lipid, while there were no significant differences between the two cultivars after removing protein sequentially. Meanwhile, the addition of extracted protein from JWR to the isolated starch significantly decreased the viscosity compared to the addition of protein extracted from IWR. The protein composition results found that the IWR protein contained about 18% globulin and 64% glutelin, while the JWR protein contained 11% globulin and 73% glutelin. The addition of glutelin to isolated starch significantly decreased viscosity compared to the addition of globulin. Therefore, the differences in the content of globulin and glutelin might be the main reasons that differentiate the pasting behaviors of the two cultivars.

16.
Macromol Biosci ; : e2100529, 2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-35362658

RESUMO

Current treatments for chronic neuropathic pain often fall short. A small-molecular compound ZL006 can suppress N-Methyl-d-aspartate receptor (NMDAR)-mediated neuropathic pain behaviors without blocking essential NMDAR function and brings new hope for neuropathic pain therapy. The persistent nature of neuropathic pain mandates the long-term treatment. However, similar to existing analgesics, ZL006 has only a short duration of action. To unleash the therapeutic potential of ZL006, the stability of ZL006 in aqueous solutions is investigated, and a ZL006-incorporated P407-based thermoresponsive injectable hydrogel is developed. The computational analysis is performed to help achieve the desired ZL006-loaded hydrogel system and elucidate the gelation mechanism. The hydrogel matrix can be loaded with ZL006 in an aqueous phase at room temperature without costly specialized equipment and no organic solvent, where the sol is formed and injectable. On subcutaneous administration and subsequent rapid warming to physiological temperature, the sol is converted to a gel. The thermoresponsive hydrogel at body temperature enables the extended release of encapsulated ZL006, and therefore a single subcutaneous injection of ZL006-hydrogel produces a prolonged and stable analgesic action in mice with spinal nerve ligation. The study provides a practical chronic neuropathic pain therapy and a new perspective on future applications of ZL006.

17.
Nat Mater ; 21(5): 518-525, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35422509

RESUMO

Spontaneous hierarchical self-organization of nanometre-scale subunits into higher-level complex structures is ubiquitous in nature. The creation of synthetic nanomaterials that mimic the self-organization of complex superstructures commonly seen in biomolecules has proved challenging due to the lack of biomolecule-like building blocks that feature versatile, programmable interactions to render structural complexity. In this study, highly aligned structures are obtained from an organic-inorganic mesophase composed of monodisperse Cd37S18 magic-size cluster building blocks. Impressively, structural alignment spans over six orders of magnitude in length scale: nanoscale magic-size clusters arrange into a hexagonal geometry organized inside micrometre-sized filaments; self-assembly of these filaments leads to fibres that then organize into uniform arrays of centimetre-scale bands with well-defined surface periodicity. Enhanced patterning can be achieved by controlling processing conditions, resulting in bullseye and 'zigzag' stacking patterns with periodicity in two directions. Overall, we demonstrate that colloidal nanomaterials can exhibit a high level of self-organization behaviour at macroscopic-length scales.


Assuntos
Nanoestruturas , Nanoestruturas/química
19.
Science ; 376(6590): 288-292, 2022 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-35420967

RESUMO

Bulk chemicals such as ethylene glycol (EG) can be industrially synthesized from either ethylene or syngas, but the latter undergoes a bottleneck reaction and requires high hydrogen pressures. We show that fullerene (exemplified by C60) can act as an electron buffer for a copper-silica catalyst (Cu/SiO2). Hydrogenation of dimethyl oxalate over a C60-Cu/SiO2 catalyst at ambient pressure and temperatures of 180° to 190°C had an EG yield of up to 98 ± 1%. In a kilogram-scale reaction, no deactivation of the catalyst was seen after 1000 hours. This mild route for the final step toward EG can be combined with the already-industrialized ambient reaction from syngas to the intermediate of dimethyl oxalate.

20.
J Agric Food Chem ; 70(16): 5159-5165, 2022 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-35420802

RESUMO

Bisulfite (HSO3-)/Sulfite (SO32-) is widely used as a food additive, but excessive use often leads to serious consequences, so the detection of HSO3-/SO32- is of great importance. In this paper, a novel 1,4-diethylpiperazine-modified coumarin-benzopyran derivative (probe QLP) has been synthesized and characterized. In PBS (10 mM, pH = 7.4), QLP displays good selectivity and is sensitive for HSO3-/SO32- over various analytes with fluorescent "OFF-ON" rapid responding (2 min), long-wavelength emission (600 nm), and a detection limit of 177 nM. With the treatment of HSO3-/SO32-, the color of the QLP solution obviously changes from blue-green to yellow, and the fluorescent color of QLP changes from colorless to amaranth. The fluorescence-enhanced mechanism is qualitatively evaluated by density functional theory calculations using the CAM-B3LYP/6-31G (d) method, which reveals that the photoinduced electron transfer leads to the fluorescence emission of the QLP-SO3H adduct. Importantly, nontoxic QLP can be used to detect HSO3-/SO32- in sugar, natural water samples, and living cells and localized to the mitochondria and monitor the mitochondrial HSO3-/SO32- level.


Assuntos
Corantes Fluorescentes , Água , Corantes Fluorescentes/química , Mitocôndrias , Sulfitos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...