COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
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2024
·
IF 8.1
Yanyan Li,Yikang Wang,Li Cui,Lie Zhao,Youyi Tian,Jiajia Shen,Junfeng Zhang,Huawei Xu,Meifang Zhu
Achieving favorable flame retardancy in polyamide 6 (PA6) without compromising its mechanical performance remains a challenge, with a notable gap in understanding the influence of flame-retardant structure on PA6 properties and mechanisms. In this study, two biomass-derived phosphonamide flame retardants, P,P-diphenyl-N-(pyridin-3-yl) phosphonamide (DPDA) and P,P-Diphenoxy-N-(pyridin-3-yl) phosphonamide (DPPA), were synthesized and incorporated into PA6 to develop flame retardant composites. Results demonstrated that the PA6-9DPDA, containing a P-C bond, achieved a UL-94 V-0 rating with a Limiting Oxygen Index (LOI) of 27.9 %, while PA6-9DPPA, containing a P-O-C bond, maintained the UL-94 V-2 rating of pure PA6 but with an increased LOI of 29.4 %. DPPA exhibited a more favorable impact than DPDA on enhancing the tensile performance of PA6. Mechanisms indicated that DPDA primarily operates through vapor phase flame retardancy, whereas DPPA utilizes condensed phase flame retardancy. Overall, this study proposes a sustainable approach for fabricating PA6 composites with enhanced comprehensive performance.
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
CHEMISTRY & BIODIVERSITY
·
2024
·Vol. 21
·期 7
·e202400929
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IF 2.3
Yuee Tian,Shiyue Ma,Yibo Liu,Yan Li,Genqiang Chen,Zhiping Che
In order to explore novel natural product-based insecticidal agent, two important intermediates ( 2 and 3 ) and 4-acyloxy-2′-bromo-6′-chloropodophyllotoxin derivatives ( 4 a – f and 5 a – f ) were designed and prepared, and their structures were confirmed by 1 H-NMR, 13 C NMR, HRMS, ESI-MS, optical rotation and melting point (mp). The stereochemical configuration of compound 4 b was unambiguously confirmed by single-crystal X-ray diffraction. Moreover, we evaluated the insecticidal activity of target compounds 4 a – f and 5 a – f against a serious agricultural pest of Mythimna separata by using the leaf-dipping method. Among all tested compounds, compounds 4 d , 5 d and 5 f exhibited stronger insecticidal activity with a final mortality rate exceeding 60 %. Especially compound 5 d exhibited the best insecticidal activity, with a final mortality rate of 74.1 %. It has been proven that introducing bromine or chlorine atoms at the C-2′, C-2′ and C-6′ positions of the E ring of podophyllotoxin can produce more potent compounds. In addition, the configuration of the C-4 position is important for insecticidal activity, and 4β-configuration is optimal. This will pave the way for further design, structural modification, and development of derivatives of podophyllotoxin as insecticidal agents. Graphical
研究领域:
有机化学
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植物保护
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农业科学
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DOI
PubMed
高影响因子
RSC Advances
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2025
·Vol. 15
·期 19
·14594-14603
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IF 4.6
Bingxue Guo,Jinfen Lou,Tingting Kuang,Yanping Wang,Kai Zhang,Jun Qin,Min He,Yufei Liu,Yong-Ji Gong
PA6 is widely used but vulnerable to thermo-oxidative aging, impacting its durability. Hindered phenols are key antioxidants that extend the service life of PA6 by slowing this aging process. However, the effect of molecular structural differences on their antioxidant activity is still elusive, impeding their development and application. Here, two antioxidants, 2-((3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)oxy)ethyl acrylate (PEA) and 2-((3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)oxy)propyl acrylate (PPA), were utilized to enhance the thermo-oxidative aging resistance of PA6. Their primary difference is that PPA possesses an electron-donating group in its molecular structure. The methyl functional group in the PPA molecule can increase the electron cloud density around the benzene ring, resulting in PPA having a higher free radical scavenging rate compared to PEA. In addition, in contrast to PEA, the low volatility and mobility of PPA ensure that its antioxidant activity can be fully utilized during aging. These factors collectively support the excellent antioxidant activity of PPA (PPA > PEA). As a result, the PA6/PPA composite maintains 88% of its original tensile strength after 12 days of continuous aging, whereas PA6/PEA and PA6/1010 (commercial antioxidant) composites retained 70% and methyl 30%, respectively. These encouraging findings provide a theoretical basis for the synthesis of antioxidants.
研究领域:
材料科学
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化学工程
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产品关联
DOI
PubMed
高影响因子
FOOD CHEMISTRY
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2021
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IF 7.514
Yun-Jiao Ma,Xiao-Yuan Wang,Bei-Wei Zhu,Ming Du,Liang Dong,Xiu-Ping Dong,Xian-Bing Xu
Vinylpyrazine compounds are widely present in foods , especially in hot-processed foods, as a class of flavor compounds ; however, their formation mechanism in food systems is still unclear. Therefore, in this study, 2-vinylpyrazine and 2-vinyl-6-methylpyrazine were identified in the Maillard model reaction of d -glucose and glycine. The Maillard model reaction of glucose–glycine was constructed to explore the effects of reaction parameters on vinylpyrazines and the related products. The Maillard reaction of [U- 13 C 6 ] glucose and glycine was established, and alkylpyrazines and formaldehyde were determined via isotope tracing technique as the precursors of vinylpyrazines. The formation of vinylpyrazines was verified by building a model reaction between alkylpyrazines and formaldehyde. The H/D exchange experiment confirmed that the active site of alkylpyrazines was on the methyl group , which was the reaction site for the condensation reaction of alkylpyrazines with formaldehyde. Results suggest that vinylpyrazines are formed by the condensation reaction of alkylpyrazines and formaldehyde.
研究领域:
食品科学
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化学
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DOI
PubMed
高影响因子
BIOCHEMISTRY-MOSCOW
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2015
·Vol. 80
·期 3
·379-389
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IF 1.303
Zhao Shancheng,Deng Chao,Wang Zhen,Teng Liping,Chen Jinghua
The roles of sugar chains such as heparan sulfate (HS) in stem cell self-renewal and differentiation are poorly understood. HS is a sugar chain with linear sulfated polyanionic disaccharide repeating structures that interact with many proteins, including structural proteins in the extracellular matrix and growth factors and their receptors. Thus, unraveling the role of HS in stem cell self-renewal and differentiation could provide new insights and technical routes in clinical stem cell applications. Here, we purified rat bone marrow mesenchymal stromal cells (BMMSCs) by density gradient centrifugation, analyzed mesenchymal stromal cell surface stemness marker expression by flow cytometry, and identified the sulfotransferases responsible for sulfation ester modification of HS. An osteogenic differentiation model was established by chemical induction reagents and confirmed via alkaline phosphatase (ALP) activity detection and the expression of the osteogenic differentiation markers Runx2 and Ocn. The expression profiles of HS sulfotransferases in rat BMMSCs before and after osteogenic induction were detected by RT-PCR and Western blot. Cell spheroids were formed in both control and osteogenic culture systems when BMMSCs were grown to high confluence. We determined that this type of cell spheroid was a highly calcified nodule by histochemical staining. Among all the sulfotransferases examined, heparan sulfate 6-O-sulfotransferase 3 (HS6ST3) mRNA and protein were upregulated in these calcified cell spheroids. HS6ST3 knockdown BMMSCs were established with RNA interference, and they had significantly lower ALP activity and decreased expression of the osteogenic differentiation markers Runx2 and Ocn. These findings suggest that HS6ST3 is involved in BMMSC differentiation, and new glycotherapeutic-based technologies could be developed in the future.
研究领域:
细胞生物学
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分子生物学
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再生医学
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DOI
PubMed
高影响因子
JOURNAL OF SEPARATION SCIENCE
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2017
·Vol. 40
·期 23
·4653-4660
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IF 2.557
Haoran Fan,Jinpeng Wang,Qingran Meng,Yaoqi Tian,Xueming Xu,Zhengyu Jin
Photoirradiation surface molecularly imprinted polymers for the separation of 6- O -α- d -maltosyl-β-cyclodextrin were synthesized using functionalized silica as a matrix, 4-(phenyldiazenyl)phenol as a light-sensitive monomer, and 6- O -α- d -maltosyl-β-cyclodextrin as a template. Fourier transform infrared spectroscopy results indicated that 4-(phenyldiazenyl)phenol was grafted onto the surface of functionalized silica. The obtained imprinted polymers exhibited specific recognition toward 6- O -α- d -maltosyl-β-cyclodextrin. Equilibrium binding experiments showed that the photoirradiation surface molecularly imprinted polymers obtained the maximum adsorption amount of 6- O -α- d -maltosyl-β-cyclodextrin at 20.5 mg/g. In binding kinetic experiments, the adsorption reached saturation within 2 h with binding capacity of 72.8%. The experimental results showed that the adsorption capacity and selectivity of imprinted polymers were effective for the separation of 6- O -α- d -maltosyl-β-cyclodextrin, indicating that imprinted polymers could be used to isolate 6- O -α- d -maltosyl-β-cyclodextrin from a conversion mixture containing β-cyclodextrin and maltose. The results showed that the imprinted polymers prepared by this method were very promising for the selective separation of 6- O -α- d -maltosyl-β-cyclodextrin.
研究领域:
分析化学
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材料科学
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产品关联
DOI
PubMed
高影响因子
ChemSusChem
·
2018
·Vol. 11
·期 14
·2332-2339
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IF 7.411
Zhong-Yu Xie,Jin Deng,Yao Fu
Graphical Fatty acids slim down : A new method for γ-lactone preparation based on ring contraction has been developed. Starting from macrolides, W(OTf) 6 was used to catalyze ring-opening polymerization then depolymerization to produce the stable five-membered γ-lactones in the ionic liquid [EMIM]OTf. γ-Lactones were also produced when the substrate was extended to terminal hydroxyfatty acids. γ-Lactones are an important class of fine chemical products and are widely used in perfumes, medicines, pesticides, dyes, and other fields. Herein, a new method for γ-lactones preparation based on ring contraction was developed. Starting from macrolides, W(OTf) 6 was used to catalyze the ring-opening polymerization then depolymerization. The depolymerization step was not a common ring-closing process, and the carbon number of the ring was reduced one by one by rearrangement to form the most thermodynamically stable five-membered ring compounds. γ-Caprolactone (180 °C for 10 h) was obtained in a yield of 94 % when [EMIM]OTf was used as the solvent, and the yield of isolated product was up to 85 %. The interaction of various components and the reaction mechanism were studied by FTIR spectroscopy and 1 H NMR spectroscopy, respectively. Furthermore, γ-lactones could be produced when the substrate was extended to terminal hydroxyfatty acids. Unexpectedly, the catalyst was poisoned by 1 equivalent of H 2 O added during the process and thus the yield decreased greatly. The reaction is green and simple, and proceeds in one pot with high atom economy (100 % for macrolides and with water as the only byproduct for terminal hydroxyfatty acid), which provides a promising approach to synthesizing γ-lactones.
研究领域:
有机化学
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绿色化学
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DOI
PubMed
高影响因子
Environmental Chemistry and Ecotoxicology
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2025
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IF 8.2
Xin Wan,Geyu Liang,Dayong Wang
The 6-PPD quinone (6-PPDQ) is derived from 6-PPD, an antioxidant added in tires. Citric acid cycle plays a pivotal role in biochemical metabolisms. In Caenorhabditis elegans , we examined effect of 6-PPDQ exposure on citric acid cycle and the role of alteration in acetyl CoA and pyruvate contents during this process. In citric acid cycle, contents of intermediates were reduced by 0.1–10 μg/L 6-PPDQ. Meanwhile, expression of key enzyme genes ( cts-1 , idh-2 , dlst-1 , and dld-1 ) for citric acid cycle was decreased by 0.1–10 μg/L 6-PPDQ. After 6-PPDQ exposure, citric acid content was reduced by cts-1 RNAi, and NADH content was reduced by idh-2 , dlst-1 , and dld-1 RNAi. Exposure to 6-PPDQ (0.1–10 μg/L) further decreased acetyl CoA and pyruvate contents, and inhibited expression of enzyme genes ( dlat-1 and dld-1 ) governing acetyl CoA synthesis and enzyme genes ( pyk-1 and pyk-2 ) governing pyruvate synthesis. After 6-PPDQ exposure, dlat-1 and dld-1 RNAi reduced contents of acetyl CoA, citric acid, and NADH, and pyk-1 and pyk-2 RNAi reduced contents of pyruvate, citric acid, and NADH. In 6-PPDQ exposed nematodes, cts-1 , idh-2 , dlst-1 , dld-1 , dlat-1 , pyk-1 , and pyk-2 RNAi further caused susceptibility to 6-PPDQ toxicity. Our results suggested 6-PPDQ exposure risk in resulting in damage on citric acid cycle, which was linked to its toxicity induction.
研究领域:
环境毒理学
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分子生物学
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DOI
高影响因子
EXPERIMENTAL CELL RESEARCH
·
2018
·
IF 3.309
Yanting Zhu,Fangwei Li,Wenhua Shi,Cui Zhai,Jian Wang,Xin Yan,Qingting Wang,Qianqian Zhang,Lan Yang,Li Gao,Manxiang Li
Up-regulation of mammalian COP9 signalosome subunit 6 (CSN6) and consequent reduction of SCF ubiquitin ligase substrate receptor β-transduction repeat-containing protein (β-TrCP) have been shown to be associated with cancer cells proliferation . However, it is unclear whether CSN6 and β-TrCP are also involved in PDGF-induced pulmonary arterial smooth muscle cells (PASMCs) proliferation. This study aims to address this issue and further explore its potential mechanisms. Our results indicated that PDGF phosphorylated Akt, stimulated PASMCs proliferation; while inhibition of PDGF receptor (PDGFR) by imatinib prevented these effects. PDGF further up-regulated CSN6 protein expression , this was accompanied with β-TrCP reduction and increase of Cdc25A. Inhibition of PDGFR/PI3K/Akt signaling pathway reversed PDGF-induced such changes and cell proliferation. Prior transfection of CSN6 siRNA blocked PDGF-induced β-TrCP down-regulation, Cdc25A up-regulation and cell proliferation. Furthermore, pre-treatment of cells with MG-132 also abolished PDGF-induced β-TrCP reduction, Cdc25A elevation and cell proliferation. In addition, pre-depletion of Cdc25A by siRNA transfection suppressed PDGF-induced PASMCs proliferation. Taken together, our study indicates that up-regulation of CSN6 by PDGFR/PI3K/Akt signaling pathway decreases β-TrCP by increasing its ubiquitinated degradation, and thereby increases the expression of Cdc25A, which promotes PDGF-induced PASMCs proliferation.
研究领域:
细胞生物学
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分子生物学
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药理学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS CHEMISTRY
·
2011
·Vol. 21
·期 34
·12784-12792
·
IF 5.101
Bin Ding,Xianfeng Wang,Jianyong Yu,Moran Wang
A nanostructured complex, polyethyleneimine (PEI) functionalized polyamide 6 (PA 6) (PEI-PA 6) nano-fiber/net (NFN), is developed as a novel sensing coating on quartz crystal microbalance (QCM) for highly sensitive formaldehyde detection. The NFN structured substrate comprising common electrospun nanofibers and two-dimensional (2D) spider-web-like nano-nets fabricated by a facile electro-spinning/netting (ESN) process, exhibit large specific surface area, high porosity and large stacking density, which make them optimal candidates for sensing applications. The responses of the sensors in response to formaldehyde were analyzed in terms of PA 6 NFN membranes morphologies, PA 6 substrate and sensing PEI coating loads, and the comparison with nanoporous fibers. Experimental results show that this new PEI-PA 6 NFN nanostructure based QCM sensor exhibits excellent formaldehyde sensing performances in terms of remarkably low detection limit (50 ppb), rapid response, superior selectivity and good reproducibility. We expect the highly sensitive and robust NFN-based QCM sensor may serve as a practical and powerful tool for gas sensing and chemical analysis.
研究领域:
材料科学
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传感器技术
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环境监测
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产品关联
DOI
高影响因子
FUEL
·
2017
·
IF 4.601
Sainan Wei,Huijun He,Yan Cheng,Chunping Yang,Guangming Zeng,Li Kang,Hui Qian,Canyao Zhu
Sulfur-containing compounds in oils are harmful to the ecosystem whose cost-effective removal is still a challenge. In this study, novel heterogeneous catalysts of cobalt supported on KIT-6 mesoporous silicas were prepared and evaluated for oxidative desulfurization (ODS) under ambient conditions using cyclohexanone peroxide (CYHPO) as the oxidant. The model oil was obtained via dissolving DBT in the n-octane. The conventional wet impregnation method was applied for the preparation of the catalysts, and cobalt nitrate was used as the precursor. The catalysts were characterized by XRD, N 2 -physisorption, FT-IR, TGA, SEM/TEM and XPS. Then their catalytic activities in total oxidation of dibenzothiophene (DBT) were evaluated at various conditions. DBT conversion by this heterogeneous ODS system reached 98.68%. Co/KIT-6 catalysts showed high ODS activity due to Ia3d mesoporous structure resulting in better cobalt dispersion, higher activity of Co, and faster diffusion of reactant and products. The Box-Behnken design showed that the optimum values for the conversion of DBT were 93 °C (oxidation temperature), 1.6 × 10 −1 g (catalyst amount) and 5.7 (O/S molar ratio), respectively. The inhibitory effect of quinoline on ODS was higher than carbazole and indole, adding quinoline into model oil under same conditions led to a decrease of the conversion of DBT from 98.68% to 65.67% when the concentration of quinoline increased from 160 ppm to 4845 ppm. Kinetics data correlated well with the pseudo-first-order equation. These data showed that this novel Co/KIT-6 catalysis system has the potential to be applied in ODS from oils.
研究领域:
化学工程
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环境科学
·
催化材料
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产品关联
DOI
高影响因子
PHARMACOLOGICAL RESEARCH
·
2020
·
IF 5.893
Huan Wang,Zhe Liu,Lingnan Guan,Jiankang Li,Siyi Chen,Wenying Yu,Maode Lai
The constitutive activation of signal transducer and activator of transcription 3(STAT3) is associated with aggressive development and metastasis in colorectal cancer (CRC), but STAT3-targeting drugs remain elusive in clinic. Here, structure-based strategy was used to remodel the natural compound cryptotanshinone into a more effective STAT3 inhibitor LYW-6. Using the Biolayer Interferometry assay, we observed that LYW-6 exhibited specific interactions with STAT3(KD = 6.6 ± 0.7 μM). Western blot analysis and electrophoretic mobility shift assays (EMSA) showed that LYW-6 inhibited the phosphorylation of STAT3 tyrosine 705 (Tyr-705) and had slight effects on STAT1 and STAT5 phosphorylation. Western blot analysis on the upstream kinases of STAT3 confirmed that the inhibitory mechanism on p-STAT3 was independent of upstream kinases. Further investigation demonstrated that LYW-6 downregulated the expression of downstream oncogenes to inhibit cell viability, cell cycle development, and potently increased cell apoptosis in human CRC cells. The invasion and metastasis linked signaling was also blocked by LYW-6 treatment. LYW-6 was found to reduce the metastasis foci in lung on tail-lung metastasis models. In addition, it was observed that LYW-6 markedly diminished STAT3 phosphorylation in tumor tissue and significantly inhibited tumor growth on xenograft models. Tumor development on chemically-induced colorectal cancer model also significantly inhibited by LYW-6 treatment. These findings provided adequate evidence that STAT3 inhibitor LYW-6 might be a potential candidate agent for CRC treatment.
研究领域:
肿瘤学
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药理学
·
分子生物学
·
癌症研究
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）