POLYMER SCIENCE SERIES B
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2019
·Vol. 61
·期 3
·240-246
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IF 0.907
Xian Rong Shen,Xiang Yi Xin,Gao Jian Gang
Abstract Supplemental activator and reducing agent atom transfer radical polymerization (SARA ATRP) of methyl acrylate was successfully performed in inexpensive, eco-friendly polyethylene glycol solvents and catalyzed by a mixed sulfite/CuBr 2 system at room temperature. The presence of polyethylene glycol in the reaction mixtures allowed fast and controlled polymerizations throughout the whole reaction time. Remarkably, a fast polymerization can be achieved with a monomer conversion reaching 90% in only 50 min using PEG 200 as the reaction solvent. The controlled character of the ATRP of methyl acrylate was confirmed by the linear increase in molecular weight with monomer conversion, the narrow molecular weight distributions ( M w / M n = 1.15) and the results of chain extension experiments. 1 H NMR analysis also confirmed the molecular structure and chain-end functionality of the obtained polymers, and the effects of PEG molecular weight and inorganic sulfites on the polymerization behavior were investigated.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
FOOD CONTROL
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2018
·
IF 3.667
Jin-Rong Bai,Kai Zhong,Yan-Ping Wu,Grosu Elena,Hong Gao
The aim of this study was to evaluate the inhibitory activity of shikimic acid (SA) against biofilm formation of Staphylococcus aureus and to explore its potential molecular mechanism. Crystal violet staining assay showed that SA clearly reduced the biomass of the biofilm at its sub-MICs. Light microscopic images and scanning electron microscope (SEM) observations suggested that SA inhibited the biofilm adhesion on glass slides and induced apparent collapse of biofilm architecture. In addition, XTT reduction assay and confocal laser scanning microscopic images illustrated that the metabolic activity and the viability of the SA-treated biofilm cells significantly decreased. Cell mobility of the SA-treated S. aureus was also inhibited. These observations suggested that SA inhibited the initial biofilm formation by interfering the metabolic activity, the cell viability, and the cell mobility of S. aureus . However, SA failed to disrupt the one-day-old mature biofilm of S. aureus even at the concentrations higher than MIC, suggesting that SA disturbed the early steps in the biofilm formation of S. aureus . qRT-PCR analyses showed that SA down-regulated the transcription of sarA , while up-regulated the transcription of agrA , which resulted in the prevention of biofilm formation. So, SA could be a potential antibiofilm agent to inhibit biofilm formation of S. aureus .
研究领域:
微生物学
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药理学
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分子生物学
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DOI
高影响因子
RSC Advances
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2019
·Vol. 9
·期 7
·3938-3945
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IF 3.049
Jin-Rong Bai,Yan-Ping Wu,Grosu Elena,Kai Zhong,Hong Gao
The biofilm formation of Staphylococcus aureus on food contact surfaces is the main risk of food contamination. In the present study, we firstly investigated the inhibitory effect of quinic acid (QA) on biofilm formed by S. aureus. Crystal violet staining assay and microscopy analysis clearly showed that QA at sub-MIC concentrations was able to significantly reduce the biofilm biomass and cause a collapse on biofilm architecture. Meanwhile, fibrinogen binding assay showed that QA had obviously effect on the S. aureus bacteria adhesion. XTT reduction assay and confocal laser scanning microscopic images revealed that QA significantly decreased metabolic activity and viability of biofilm cells. In addition, qRT-PCR analysis explored the potential inhibitory mechanism of QA against biofilm formation, which indicated that QA significantly repressed the gene sarA and activated the gene agrA. Moreover, QA exhibited a highly ability to reduce the number of sessile S. aureus cells adhered on the stainless steel. So, it was suggested that QA could be used as a promising antibiofilm agent to control biofilm formation of S. aureus.
研究领域:
微生物学
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食品安全
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分子生物学
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DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2025
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IF 11.3
Jinjian Hou,Wenjuan Wang,Zanli Fu,Yuting Hu,Zhongchi Wu,Xiaojin Wu,Jianan Hu,Haiming Yu,Gaobo Yu,Jiacheng Li
In recent years, heavy oil-solid separation has attracted quantities of attention, and ionic liquids (ILs) enhanced solvent extraction has been widely studied. However, the detailed mechanism of ILs effect onto the heavy oil recovery was unclear, especially the interaction role between ILs and heavy oil SARA. In order to solve these problems, this paper used the experiment and molecular dynamics simulation methods to explore the four ILs ([Bmmim][PF 6 ], [C 12 mim][Ac], [C 12 mim][BF 4 ], and [Emim][Ac]) effect on enhancing the solvent extraction for oil sands. The experimental results showed that the ILs could enhance the solvent extraction process, improve heavy oil recovery, reduce bitumen viscosity, decrease oil-sand interaction force, alter the sand particles wettability. The extraction efficiency of [Bmmim][PF 6 ] + toluene reached 93.9 %. Additionally, molecular dynamics (MD) simulations were conducted to analyze the interaction mechanisms between heavy oil SARA (saturates, aromatics, resins, asphaltenes) and solvents and ILs. The simulations results indicated that the saturates, aromatics, resins and asphaltenes have different interaction role with the different ILs under varieties of solvents, and the interaction role strength was related to the functional groups and heteroatom. In the end, the detailed mechanism of ILs enhancing solvent extraction for oil sands was put forward.
研究领域:
石油工程
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化学工程
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分子模拟
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DOI
PubMed
高影响因子
Virulence
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2025
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IF 5.4
Jian-Guo Li,Wei-Cheng Zhong,Long-Gen Zhong,Chao-Yan Niu,Ting-Yin Lu,Chuan-Jian Zhang,Jian Sun,Xiao-Ping Liao,Yu-Feng Zhou
Methicillin-resistant Staphylococcus aureus (MRSA) remains a major therapeutic challenge and poses a significant global health threat. Developing adjuvants to enhance the efficacy of existing antibiotics represents a promising strategy to address this issue. In this study, we evaluated auranofin as an adjuvant to potentiate the activity of linezolid against MRSA. Auranofin significantly increased MRSA susceptibility to linezolid, promoted intracellular linezolid accumulation, and suppressed the emergence of MRSA resistance to linezolid. Mechanistically, auranofin inhibited the Trx/TrxR system, inducing redox imbalance and reactive oxygen species (ROS) accumulation, which triggers DNA damage and transcriptional dysregulation. Auranofin synergized with linezolid to achieve dual inhibition of MRSA protein synthesis. Furthermore, auranofin downregulated the global regulator sarA, impaired SarA DNA-binding activity, and enhanced SarA phosphorylation, thereby attenuating SarA-mediated virulence factors (eg, adhesins and toxins) and biofilm formation. Importantly, auranofin fully restored anti-MRSA activity of linezolid in both Galleria mellonella and murine bacteremia models. Collectively, these findings identify auranofin as a promising adjuvant to linezolid and highlight its potential to improve therapeutic outcomes against invasive MRSA infections.
研究领域:
微生物学
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传染病学
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抗生素耐药性
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药理学
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分子生物学
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DOI
PubMed
高影响因子
MICROBIAL PATHOGENESIS
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2026
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IF 3.9
Jingyan Wei,Shixin Li,Shuaiqi Ma,Peihang Jiang,Asma Riaz,Fengying Feng,Hongxin Niu,Jian He
Staphylococcus aureus is a major human pathogen mainly involved in chronic biofilm-related infections, especially at epithelial surfaces and wound sites, owing to its ability to form antibiotic-resistant biofilms and release virulence factors. Conventional antibiotics often fail to eradicate established biofilms and may contribute to the emergence of drug resistance, underscoring the urgent need for alternative biofilm-inhibiting and antivirulence strategies. Herein, we synthesized several dicyclic peptides, including cyclo(L-Phe, L-Hyp) and its stereoisomers cyclo(L-Phe, D-Hyp) and cyclo(D-Phe, L-Hyp), to evaluate their ability to inhibit S. aureus biofilm formation. All cyclic dipeptides exhibited a minimum inhibitory concentration (MIC) of 1 mg/mL. Biofilm inhibition was assessed via crystal violet staining and confocal laser scanning microscopy. At 0.5 mg/mL (1/2 MIC), the compounds exhibited superior inhibition of 24 h biofilm formation compared with vancomycin, with cyclo(L-Phe, D-Hyp) showing the most profound inhibitory activity. qRT-PCR revealed that at 0.25 mg/mL (1/4 MIC), cyclo(L-Phe, D-Hyp) significantly downregulated the expression of the Agr -quorum-sensing system ( RNAIII : −75.7%; hla : −61.7%; psm-α : −73.3%), the ica operon ( icaA : −71%; icaD : −76.7%), and sarA (−69.3%) ( P < 0.0001). Notably, cyclo(L-Phe, D-Hyp) showed low cytotoxicity (CC 50 = 5.13 ± 0.27 mg/mL) and negligible hemolysis (<1 %) at twice its MIC, indicating a favorable safety margin for antimicrobial use. These cyclo dipeptides can be formulated for topical delivery to sites such as skin, mucosa, or open wounds, providing a practical approach for localized treatment of biofilm-associated infections. These findings identify cyclo(L-Phe, D-Hyp) as a promising lead for the development of topical anti-infective agents targeting chronic S. aureus biofilm-associated infections.
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PubMed
高影响因子
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