POLYMER
·
2024
·
IF 4.1
Lulu He,Jinfen Lou,Xiang Nie,Min He,Qiao Fan,Jifei Yang,Yufei Liu,Shuhao Qin,Jie Yu
Polyamide 6 (PA6) is widely utilized, yet it confronts challenges such as susceptibility to thermal oxidative aging and high sensitivity to notch impact during usage. In addressing these issues, two novel toughening macromolecular antioxidants, 3-(3,5-di- tert -butyl-4-hydroxyphenyl) propionic acid 2-acrylamidoethyl ester styrene copolymer (PAS) and 3-(3,5-di- tert -butyl-4-hydroxyphenyl) propionic acid 2-acrylamidoethyl- N -phenylmaleimide copolymer (PAN), were synthesized via free radical copolymerization. Upon incorporation into PA6, their effects on PA6 performance were investigated. Relative to pure PA6, PA6/PAN and PA6/PAS exhibited significant improvements in fracture elongation, with increases of 136.91 % and 313.83 % respectively, along with notch impact strength enhancements of 18.55 % and 24.89 % respectively. This enhancement can be attributed to PAN and PAS reducing the hydrogen bond density between PA6 molecular chains. Subsequent long-term accelerated thermal aging tests conducted at 150 °C, as well as performance testing of samples before and after aging, revealed that the aging of PA6/PAN and PA6/PAS could be delayed by 4–12 days. The exceptional anti-thermal oxidative aging ability and toughening effect of these two macromolecular antioxidants in PA6 showcase promising prospects for its expanded applications.
研究领域:
材料科学
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高分子化学
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DOI
高影响因子
INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY
·
2026
·
IF 3.7
Junna Liu,Qi Chen,June-Sun Yoon,Mujuan Guo,Chunxiao Yang,Xuguo Zhou,Youjun Zhang,Huipeng Pan
The steroid hormone 20-hydroxyecdysone (20E) is the central regulator of insect molting, yet the upstream transcription factors controlling its pathway remain poorly characterized. Here, we investigate the role of the bHLH-PAS transcription factor Trachealess (HvTrh) in the 28-spotted ladybeetle, Henosepilachna vigintioctopunctata . HvTrh was ubiquitously expressed during larval development, with peak transcript levels in the pupal stage. RNAi-mediated silencing of HvTrh induced severe molting defects and high mortality across all larval instars. This was associated with a significant reduction in 20E titers and the suppression of key 20E pathway genes. The resulting molting defects were not rescued by exogenous 20E, indicating a disruption of tissue competence. Histological analysis confirmed that HvTrh knockdown impaired chitin deposition and new cuticle remodeling. Among the downregulated genes, HvE75 was the most strongly suppressed. Mechanistically, we demonstrated that HvTrh directly activates the HvE75 promoter by binding to a specific central nervous system midline element (CME), as validated by dual-luciferase reporter assays and electrophoretic mobility shift assays. Our findings establish HvTrh as a critical upstream regulator of insect molting, proposing a model where it governs the 20E signaling cascade, at least in part, through the direct transcriptional control of HvE75 .
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DOI
PubMed
高影响因子
CHEMICAL PHYSICS LETTERS
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2010
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IF 2.291
Chengling Han,Tingting Chen,Lily Zu
A terbium chelate formed with diethylenetriaminepentaacetic acid and p -aminosalicylic acid (Tb–DTPA–pAS) was labeled on a 23-mer DNA strand and used as donor in the fluorescence resonance energy transfer (FRET) study of DNA hybridization. The change in donor fluorescence lifetime with and without DNA-bind acceptor carboxytetramethylrhodamine (TAMRA) showed high energy transfer efficiency (87%). The distance between the two ends of the 23-mer double-stranded DNA was estimated. This study provides a possibility of using the Tb-chelate as a probe in the studies of the geometry-dependent interaction between DNA strands or proteins.
研究领域:
化学
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分子生物学
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生物物理学
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DOI
高影响因子
Peptide Science
·
2023
·
IF 2.4
Qianyu Zhang,Hongjing Chen,Huali Chen
PASylation has been recently reported as a feasible alternative to PEGylation, which in essence is using polypeptides constituted of a combination of proline, alanine and serine for the hydrophilic modification of pharmaceuticals. In this work, we focused on the biocompatibility evaluation of two PAS peptides, (PAS) 8 and (PA 3 ) 7 as well as the more frequently used polymers polyethylene glycol (PEG) and polyglycerol (PG). It has been verified in this study that (PAS) 8 and (PA 3 ) 7 both exhibited low cell toxicity against HUVEC and RAW 264.7 cell lines. They also showed negligible RBC hemolysis and agglutination, which demonstrated adequate hemocompatibility. Their potential interactions with bovine serum albumin have also been investigated, and the results indicated little hydrophobic interactions between the polymers and protein. In conclusion, (PAS) 8 and (PA 3 ) 7 as well as PEG and PG all showed considerable compatibility and safety in these studies, suggesting that (PAS) 8 and (PA 3 ) 7 could be considered as potential candidates for PEG replacement in future studies. Graphical
研究领域:
药学
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生物医学工程
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材料科学
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DOI
高影响因子
MICROCHIMICA ACTA
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2017
·Vol. 184
·期 7
·2073-2079
·
IF 4.58
Chen Lihua,Liu Xiang,Wang Cunguo,Lv Shuli,Chen Chuangfu
The paper describes an electrochemical nitrite sensor based on the use of a nanocomposite consisting of poly(3,4-ethylenedioxythiophene) (PEDOT) doped with polyacenic semiconductor (PAS), a quasi-graphene carbon material. The composite possesses a large specific surface area and a large number of active sites. It shows high catalytic activity towards the oxidation of nitrite. Such activity is not observed in the individual components. Nitrite provides a well-defined oxidation peak at 0.80 V (vs. Ag/AgCl) at a pH value of 7.4. The influence of many possible ionic interferents was found to be negligible. In addition, the oxidation peaks of dopamine hydrochloride, ascorbic acid, uric acid and nitrite are well separated from each other. Under optimized experimental conditions, anodic peak currents are linearly related to nitrite concentrations in the range from 0.3 μM to 6.6 mM, and the detection limit is 98 nM (at an S/N ratio of 3). The sensor was used to quantify nitrite in (spiked) tap water and sausage samples, where it gave acceptable recoveries.
Schematic presentation of a nanocomposite consisting of poly(3,4-ethylenedioxythiophene) (PEDOT) doped with polyacenic semiconductor (PAS). The composite possesses a large specific surface area and a large number of active sites. It shows high catalytic activity towards the oxidation of nitrite.
研究领域:
电化学
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传感器
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材料科学
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分析化学
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DOI
高影响因子
BIOSCIENCE REPORTS
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2022
·Vol. 42
·期 2
·
IF 3.976
Wang Xiaoya,Zhang Xinyu,Su Jianqing,Chu Xiuling
Here, we study the therapeutic effect of Acanthopanax senticosus total flavonoids (ASTFs) using a mouse intestinal inflammation model. The inflammation model used in the present study was developed through lipopolysaccharide (LPS) treatment of mice. The experimental mice were divided into a control group, model group (10 mg/kg LPS), dexamethasone group (1 mg/kg DEX) and ASTF low-, medium- and high-dosage groups (200, 400 and 800 mg/kg, respectively). The morphological and structural changes in the ileum, jejunum and duodenum were observed using HE staining. The number of intestinal goblet cells (GCs) was calculated based on PAS staining. The contents of interleukin (IL)-1β, IL-6, prostaglandin E2 (PGE2) and tumor necrosis factor α (TNF-α) were determined using enzyme-linked immunosorbent assay (ELISA) and the related mRNA expression level were measured by RT-PCR. The protein expression levels of Toll-like receptor 4 (TLR4), MyD88, p65 and p-p65 were measured using Western blotting. In addition, the 16S rRNA sequences of bacterial taxa were amplified and analyzed to assess changes in the intestinal microbes of LPS-induced mice and also in response to regulation by ASTF. Following intervention with ASTF, different therapeutic effects were shown according to the various dosages tested, all of which resulted in improved intestinal morphology and an increased number of intestinal GCs, while the contents of IL-1β, IL-6, PGE2 and TNF-α and the related mRNA expression level were significantly reduced. The TLR4, MyD88 and p-p65/p-65 protein expression levels were also significantly reduced. In addition, 16S rRNA sequencing results show that LPS disrupts the structure of mouse gut microbes, though we observed that normal microbial status can be restored through ASTF intervention.
研究领域:
药理学
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免疫学
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微生物学
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分子生物学
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DOI
PubMed
高影响因子
EUROPEAN JOURNAL OF PHARMACOLOGY
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2024
·
IF 4.2
Taige Chen,Nan Zhou,Qi Liang,Qi Li,Boda Li,Yiran Chu,Di Zhang,Zeying Chen,Jia-Ruei Tsao,Xuebing Feng,Kai Hu
Dry eye disease (DED) is a complex disorder driven by several factors like reduced tear production, increased evaporation, or poor tear quality. Oxidative stress plays a key role by exacerbating the inflammatory cycle. Previous studies explored antioxidants for DED treatment due to the link between oxidative damage and inflammation. Biochanin A (BCA) is a bioisoflavone from red clover with potent anti-inflammatory effects. This study investigated BCA's therapeutic potential for DED. Human corneal epithelial cells were cultured under hyperosmotic conditions to mimic DED. BCA treatment increased cell viability and decreased apoptosis and inflammatory cytokine expression. A DED mouse model was developed using female C57BL/6 mice in a controlled low-humidity environment combined with scopolamine injections. Mice received eye drops containing phosphate-buffered saline, low-dose BCA, or high-dose BCA. The effectiveness was evaluated by measuring tear volume, fluorescein staining, eye-closing ratio, corneal sensitivity and PAS staining. The levels of inflammatory components in corneas and conjunctiva were measured to assess DED severity. Maturation of antigen-presenting cells in cervical lymph nodes was analyzed by flow cytometry. BCA eye drops effectively reduced inflammation associated with DED in mice. BCA also decreased oxidative stress levels by reducing reactive oxygen species and enhancing the nuclear translocation of nuclear factor erythroid-2-related factor 2 (Nrf2). These findings demonstrate that BCA ameliorates oxidative stress and ocular surface inflammation, indicating potential as a DED treatment by relieving oxidative damage and mitigating inflammation.
研究领域:
药理学
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眼科
·
炎症研究
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氧化应激
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细胞生物学
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动物模型
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DOI
PubMed
高影响因子
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
·
2020
·
IF 6.444
Ao Zhong,Jinhui Li,Yu Zhang,Fan Zhang,Tao Wang,Guoping Zhang,Rong Sun,Ching-Ping Wong
The mechanical brittleness and structure collapse of three-dimensional (3D) graphene composite construction is still an enormous issue in flexible performance of complex. In addition, low temperature and efficient process become increasingly significant and noticeable in field of semiconductor device to prevent from huge resource waste and energy consumption. Herein, we report a special method to prepare 3D graphene/polyimide (rGO/PI) aerogel with low temperature and rapid procedure. The aerogel is synthesized by introducing water-soluble polyamic acid ionic salt (PAS) and ice-templating directional solidification to establish unique oriented structure, and by energy-efficient microwave to realize low temperature and rapid imidization. The preparative rGO/PI nanocomposite aerogels hold excellent electrical conductivity , desirable flexibility, superior pressure-responsive properties, remarkable compression sensitivity and durability, so that adapt to multifarious deformations with huge potential for flexible wearable devices .
研究领域:
材料科学
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纳米技术
·
柔性电子
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DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2018
·
IF 6.578
Yujian Yao,Meng Li,Xingzhong Cao,Peng Zhang,Wen Zhang,Junfeng Zheng,Xuan Zhang,Lianjun Wang
A new sulfonated diamine monomer , 4,4′-((1,4-phenylenebis(methylene))bis(azanediyl))dibenzenesulfonic acid (PMABSA) was synthesized and used as the sole aqueous reactant to fabricate a novel reverse osmosis (RO) membrane with trimesoyl chloride (TMC), in place of conventional m -phenylene diamine (MPD). The separation performance of the PMABSA/TMC membrane was optimized by the response surface method (RSM) by means of evaluating the pure water permeability (PWP) and salt rejection (R) to NaCl, and optimal results of PWP of 1.18 ± 0.03 L m −2 h −1 bar −1 , and R of 98.2 ± 0.4%, respectively, were achieved at 1.55 MPa. Owing to the rigid benzene ring in the center of the molecule, which may have a blocking effect during the interfacial polymerization (IP) process, the resulting barrier layer was less compact and had low thickness. Both molecular dynamics (MD) simulation and positron annihilation spectroscopy (PAS) revealed the creation of sufficient free volumes in the sulfonated polyamide matrix. Regardless of the slightly lower water permeation, the PMABSA/TMC membrane exhibited a superior rejection ability to all the ions compared to that of commercial SW30HR (Dow Chemical) in a model seawater separating test. Overall, all the results indicated the great potential of the novel membrane as a new choice of non-MPD RO membrane for seawater desalination.
研究领域:
材料科学
·
化学工程
·
环境科学
·
水处理
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DOI
高影响因子
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