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1.
J Am Chem Soc ; 144(12): 5535-5542, 2022 03 30.
Artigo em Inglês | MEDLINE | ID: mdl-35297616

RESUMO

A copper-catalyzed regiodivergent hydrosilylation of a wide range of simple allenes is reported. Linear and branched allylsilanes were formed by judicious choice of solvents. Furthermore, branched allylsilanes were obtained with high enantioselectivity (up to 97% enantiomeric excess) with the aid of a C2-symmetric bisphosphine ligand in the unprecedented asymmetric allene hydrosilylation.


Assuntos
Alcadienos , Cobre , Catálise , Estereoisomerismo
2.
Org Biomol Chem ; 19(6): 1334-1343, 2021 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-33464269

RESUMO

A base-promoted (4 + 2) cyclization of aza-o-quinone methides (aza-o-QMs) in situ generated from N-(o-chloromethyl)aryl amides was established. In this approach, azlactones were utilized as competent two-atom reaction partners to undergo (4 + 2) cyclization with aza-o-QMs, which afforded a series of dihydroquinolinone derivatives in overall good yields (up to 98%). This protocol has not only advanced the development of aza-o-QM-involved reactions, but also offered a useful method for constructing biologically important dihydroquinolinone frameworks.


Assuntos
Amidas/química , Iminas/química , Lactonas/química , Quinolonas/síntese química , Ciclização
3.
Analyst ; 145(5): 1550-1562, 2020 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-31951223

RESUMO

The unique physical structure and chemical and electrical properties of graphene make it an ideal choice for sensor materials. The sensing platform of biomolecule functionalized graphene has received extensive attention due to its high sensitivity and selectivity, especially the biosensors constructed by combining antibodies, nucleic acids and enzymes that efficiently recognize specific targets with graphene having a large specific surface area and a fast electron transfer rate, which has become a significant research direction. In this paper, electrochemical biosensors based on graphene materials developed in recent years are summarized. The methods of functional modification of graphene, graphene oxide and reduced graphene oxide with antibodies, nucleic acids and enzymes are briefly described. In addition, the advantages and disadvantages of the constructed electrochemical biosensors in detecting pathogens and disease markers are also reviewed. Finally, we are optimistic about this prospect for the development direction and application prospects of such electrochemical biosensors.


Assuntos
Anticorpos/química , Biomarcadores/análise , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Enzimas/química , Grafite/química , Ácidos Nucleicos/química , Doença/classificação , Humanos
4.
Vet Microbiol ; 298: 110219, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-39182469

RESUMO

Coronaviruses are causing epizootic diseases and thus are a substantial threat for both domestic and wild animals. These viruses depend on the host translation machinery to complete their life cycle. The current paper identified cellular RNA-binding proteins (RBPs), La-related protein 4 (LARP4) and polyadenylate-binding protein cytoplasmic 1 (PABPC1), as critical regulators of efficient translation of the coronavirus porcine epidemic diarrhea virus (PEDV) mRNA. In Vero cells, PEDV infection caused LARP4 to migrate from the nucleus to the cytoplasm in a chromosome region maintenance1 (CRM1)-independent pathway. In the absence of the nuclear export signal of LARP4, viral translation was not promoted by LARP4. A further study unveiled that the cytoplasmic LARP4 binds to the 3'-terminal untranslated region (3'UTR) of PEDV mRNA with the assistance of PABPC1 to facilitate viral translation. LARP4 knockdown reduced the promotion of the PABPC1-induced 3'UTR translation activity. Moreover, the rabbit reticulocyte lysate (RRL) system revealed that the prokaryotic expressed protein LARP4 and PABPC1 enhance PEDV mRNA translation. To our knowledge, this is the first study demonstrating that PEDV induces nucleo-cytoplasmic shuttling of LARP4 to enhance its own replication, which broadens our insights into how viruses use host's RBPs for the efficient translation of viral mRNA.

5.
Foods ; 13(20)2024 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-39456298

RESUMO

This study aims to address the gap in understanding of the impact of the sample quantity, traceability range, and shelf life on the accuracy of mung bean origin traceability models based on near-infrared spectroscopy. Mung beans from Baicheng City, Jilin Province, Dorbod Mongol Autonomous, Tailai County, Heilongjiang Province, and Sishui County, Shandong Province, China, were used. Through near-infrared spectral acquisition (12,000-4000 cm-1) and preprocessing (Standardization, Savitzky-Golay, Standard Normal Variate, and Multiplicative Scatter Correction) of the mung bean samples, the total cumulative variance contribution rate of the first three principal components was determined to be 98.16% by using principal component analysis, and the overall discriminatory correctness of its four origins combined with the K-nearest neighbor method was 98.67%. We further investigated how varying sample quantities, traceability ranges, and shelf lives influenced the discrimination accuracy. Our results indicated a 4% increase in the overall correct discrimination rate. Specifically, larger traceability ranges (Tailai-Sishui) improved the accuracy by over 2%, and multiple shelf lives (90-180-270-360 d) enhanced the accuracy by 7.85%. These findings underscore the critical role of sample quantity and diversity in traceability studies, suggesting that broader traceability ranges and comprehensive sample collections across different shelf lives can significantly improve the accuracy of origin discrimination models.

6.
J Phys Chem Lett ; 15(35): 9043-9050, 2024 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-39194150

RESUMO

Herein, by using state-of-the-art mass spectrometry, we demonstrated experimentally that the bimetallic copper-vanadium oxide cluster anions CuVO3,4- can catalyze the reduction of NO by CO into N2O and CO2. Note that the catalysis of NO reduction by CO has been rarely established in the gas phase and noble-metal containing clusters were commonly emphasized. Benefiting from quantum-chemical calculations, the Cu-V synergistic effect that both metal atoms work energetically to favor NO adsorption, N-N coupling, and CO oxidation by facilitating electron transfer can be understood at a strictly molecular level. Theoretical results demonstrated that the precaptured NO molecule encourages the adsorption of the second NO by electron donation. This finding deepens our understanding on NO reduction that NO functions not only as a reactant but also as a promoter during the reactions. This discovery could be helpful to permeate the nature and mechanism of active sites on related copper-vanadium heterogeneous catalyst used in real-life NO reduction.

7.
Front Neurosci ; 18: 1360935, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38686327

RESUMO

Objective: According to the World Alzheimer's Disease Report in 2015,there were 9.9 million new cases of dementia in the world every year. At present, the number of patients suffering from dementia in China has exceeded 8 million, and it may exceed 26 million by 2040.Mild cognitive impairment (MCI) refers to the pathological state of pre-dementia with the manifestation of the progressive decline of memory or other cognitive functions but without decline of activities of daily life. It is particularly important to prevent or prolong the development of MCI into dementia. Research showing effects of rhythmic auditory stimulation based-movement training(RASMT) interventions on cognitive function is also emerging. Therefore, the present meta-analysis briefly summarize findings regarding the impacts of RASMT programs on cognitive impairment. Methods: Data from Pubmed, Embase, and Cochrane Library were utilized. The impact of RASMT on cognitive functions was evaluated using indicators such as overall cognitive status, memory, attention, and executive functions. The REVMAN5.3 software was employed to analyze bias risks integrated into the study and the meta-analysis results for each indicator. Results: A total of 1,596 studies were retrieved, of which 1,385 non-randomized controlled studies and 48 repetitive studies were excluded. After reviewing titles and abstracts of the remaining 163 articles, 133 irrelevant studies were excluded, 30 studies were downloaded and read the full text. Among 30 articles, 18 articles that did not meet the inclusion criteria were excluded, the other 12 studies were included in this meta-analysis. Utilizing the Cochrane Collaborative Network Bias Risk Assessment Scale, it was found that 11 studies explained the method of random sequence generation, nine studies did not describe allocation concealment, four were single-blinded to all researchers, and eight reported single-blinding in the evaluation of experimental results. In the meta-analysis, the main outcomes showed statistically significant differences in overall cognitive status [MD = 1.19, 95%CI (0.09, 2.29), (p < 0.05)], attention [MD = -1.86, 95%CI (-3.53, -0.19), (p < 0.05)], memory [MD = 0.71, 95%CI (0.33, 1.09), (p < 0.01)], and executive function [MD = -0.23, 95% CI (-0.44, -0.02), (p < 0.05)]. Secondary outcomes indicated no statistically significant differences in verbal fluency [MD = -0.51, 95%CI (-1.30, 0.27), (p = 0.20)], while depression [MD = -0.29, 95% CI (-0.42, -0.16), (p < 0.01)] and anxiety [MD = 0.19, 95% CI (0.06, 0.32), (p < 0.01)] exhibited statistically significant differences. The GRADEpro GDT online tool assessed the quality of evidence for the outcome measures, revealing one low-quality outcome, two moderate-quality outcomes, and one high-quality outcome in this review. Conclusion: This study shows that RASMT can improve the general cognitive status, memory, attention and executive function of patients with cognitive impairment. The quality of evidence revealed that MMSE was low, attention and memory were moderate, and executive function was high. The RAMST program (type of exercise: play percussion instruments; time of exercise: 30-60 min; frequency of exercise: 2-3 times/week; duration of exercise: more than 12 weeks) was proved to be more effective in improving cognitive function. However, the sample size is relatively insufficient, the future needs further study. Systematic review registration: PROSPERO, identifier: CRD42023483561.

8.
J Agric Food Chem ; 71(16): 6277-6287, 2023 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-37068196

RESUMO

In moths, the interactions between chemosensory proteins (CSPs) and sex pheromones have yet to be comprehensively investigated. Here, we examined the function of AlepCSP2 in male Athetis lepigone based on protein expression, molecular docking, site-directed mutagenesis, fluorescence competitive binding analyses, and RNA interference (RNAi) experiments. We found that AlepCSP2 showed strong binding affinity for two sex pheromones and five maize volatiles and that binding was optimal under neutral conditions. Furthermore, we identified six amino acids as being key residues involved in the interaction between AlepCSP2 and multiple ligands. Further RNAi showed that siCSP2 males displayed consistently lower electroantennography responses to two sex pheromones and three maize volatiles at different dosages tested, and the mating rate also decreased significantly by 37.50%. These findings will contribute to characterizing the binding mechanisms of moth CSPs to sex pheromones and host volatiles and also identify unique targets for developing novel pest behavior disruptors.


Assuntos
Mariposas , Atrativos Sexuais , Masculino , Animais , Atrativos Sexuais/metabolismo , Zea mays/genética , Zea mays/metabolismo , Simulação de Acoplamento Molecular , Mariposas/metabolismo , Proteínas de Insetos/metabolismo , Percepção , Feromônios/metabolismo
9.
Org Lett ; 24(14): 2660-2664, 2022 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-35377669

RESUMO

A copper-catalyzed borylation of propargyl dichlorides was developed under mild reaction conditions. The corresponding chloro-substituted allenyl-Bdan products were obtained in good yields. The utilities of allenyl-Bdan products were examined by their diverse derivatizations.


Assuntos
Cobre , Catálise , Estereoisomerismo
10.
RSC Adv ; 8(72): 41143-41149, 2018 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-35559324

RESUMO

A novel biosensing platform was developed by integrating a new ssDNA aptamer and graphene oxide (GO) for highly sensitive and selective detection of liver cancer biomarkers (alpha-fetoprotein, AFP). The key concept of this biosensing platform is that the fluorescence of dye-modified ssDNA can be effectively quenched by GO after forming the hybrid structure of graphene oxide-ssDNA (GO-ssDNA). The AFP can selectively react with GO-ssDNA and lead to the decomposition of GO-ssDNA, which results in the recovery of fluorescence, and an increase in fluorescence intensity with the increasing concentration of AFP in the range of 0 to 300 pg mL-1. The linear range was obtained from 1 to 150 pg mL-1 and the detection limit was 0.909 pg mL-1. Moreover, this biosensing platform can be applied to serum and cell imaging for the detection of AFP. The results show that the proposed biosensor has great potential application in AFP-related clinical diagnosis and research.

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