查找使用阿拉丁产品的科研文献

Ductile poly[(3-hydroxybutyrate)-co-(4-hydroxybutyrate)]-based blends derived from biomass

Guoqiang Wang,Xiang Chi

Poly[(3-hydroxybutyrate)- co -(4-hydroxybutyrate)] (P34HB), poly[(butylene succinate)- co -(butylene furandicarboxylate)] (PBSF) and poly(vinyl acetate) (PVAc) were melt-blended to prepare P34HB/PBSF/PVAc blends with improved ductility. The thermal properties, mechanical properties, rheological properties and morphology of the blends were systematically studied. The addition of PBSF promoted the melt crystallization of P34HB. The temperatures at 5% weight loss of the blends were higher than that of P34HB. The surface of the blends was investigated using scanning electron microscopy. The surface of P34HB was very smooth, but the surfaces of the blends were rough. PVAc can increase the compatibility between P34HB and PBSF. Compared with P34HB, the elongation at break of the blends was increased to 219.1%. © 2024 Society of Industrial Chemistry.

Cationic 4-Vinylpyridine Copolymer Nanospheres with Dual Active Centers for Antibacterial Coatings

Xiaobing Ma,Xiangbin Sun,Tian Li,Rongmin Wang,Yufeng He,Pengfei Song

To prevent the transmission of diseases caused by microorganisms, more and more focus was placed on the creation of antibacterial coatings. In this work, we reported a creative synthesis of antibacterial cationic 4-vinylpyridine polymer nanospheres (CvpPMs). The nanospheres of decreasing size were produced by the self-assembly of stiff polymer chains of styrene (St) and cationic 4-vinylpyridine (4vp) polymer. Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and dynamic light scattering (DLS) were employed to describe the CvpPMs’ structural morphology and other characteristics. CvpPMs were N+-surfaced cationic nanospheres that had an average diameter of 250 nm. After evaluation against Staphylococcus aureus and Escherichia coli, the results showed a significant antibacterial rate of 98% after 72 h and, even more impressive, 95% after 120 h. The synergistic interaction of amphiphilic groups (ethylsulfobetaine methacrylate, SBMA) and quaternary ammonium pyridinium groups was responsible for the exceptional performance of CvpPMs. In addition, it mimicked the N+–π interactions of adhesion, which significantly enhanced its adhesion strength, and the coatings also achieved antibacterial rates of averaging over 95%. In conclusion, the type of antibacterial copolymer nanospheres hopes to offer an avenue for developing antibacterial coatings.

Engineering Ternary Atomic-Scale Catalytic Sites to Efficiently Remove Concentrated 4-Chlorophenol

Xiao Ge,Wenjing Li,Jie Wang,Yangfan Yuan,Hongxia Xu,Bin Gao,Shengsen Wang,Xiaozhi Wang,Yuen Wu

The ability of single-atom catalysts (SSCs) to degrade refractory organic pollutants in peroxymonosulfate (PMS)-based heterogeneous catalysis can be compromised due to less diversity in reactive species and unfavorable affinity with PMS. Herein, the as-prepared ternary atomic-scale site catalyst comprising single-atomic Fe/Ce sites and Fe cluster sites (Fe-Ce-BC-900) could completely remove concentrated 4-chlorophenol (4-CP, 40 mg L–1) in aqueous solution within 30 min, 1.20–1.35 times more efficient than Fe SSCs or Ce SSCs. The reactive oxygen species (ROSs) could be highly diversified on the ternary atomic-scale sites because of the Janus mechanisms: the production of nonradicals (1O2) through PMS oxidation and the generation of radicals (SO4•– and •OH) via PMS reduction on the ternary catalytic sites, which accounted for oxidative degradation of concentrated 4-CP. Density functional theory (DFT) calculations indicated that the ternary catalytic sites enhanced the uneven charge distribution and down-regulated the d-band center of Fe-Ce-BC-900 as compared to Fe-BC-900 and Ce-BC-900 catalysts, thereby optimizing the adsorption energy of PMS molecules and promoting electron transfer between metal sites and adjacent oxygen atoms. This study provides valuable insights into the configuration of multicatalytic sites for detoxification of organic-contaminants-polluted wastewater.

Bromodomain containing 4 inhibition combats gastric precancerous lesions via modulating macrophage polarization

Lei Zhu,Qingxin Cai,Gang Li,Xiaoming Zou

Objective Gastric precancerous lesions (GPL), characterized by intestinal metaplasia and dysplasia, marks a pivotal juncture in the transformation from gastritis to gastric cancer. Research on GPL could offer fresh perspectives on preventing cancer occurrence. Methods This study employed 1-methyl-3-nitro-1-nitrosoguanidine (MNNG) to establish GPL rat models and knocked BRD4 down in vivo to assess its impact on the lesions and macrophage morphology. Following that, the impacts of BRD4 knockdown on the malignant phenotypes of human gastric epithelial GES-1 cells were determined. Moreover, conditioned medium from macrophage was gathered and used for GES-1 cell culture. The involvement of macrophage polarization in the BRD4 regulatory mechanism in GES-1 cells was assessed. Results This study elucidated that MNNG induced an increase level of BRD4 in the rat models. BRD4 knockdown reduced lesions based on pathological sections and immunohistochemistry to detect proliferative antigens. Western blotting and immunofluorescence showed that BRD4 knockdown suppressed epithelial-mesenchymal transition and macrophage M2 polarization. In in vitro experiments, BRD4 knockdown inhibited the malignant phenotype of GES-1 cells and the differentiation of THP-1 cells into M2 macrophages, respectively. The conditioned medium from M2 macrophages with BRD4 knockdown was co-incubated with GES-1 cells, which attenuated the malignant phenotypes compared with the medium from M2 macrophages. Conclusion: Through in vivo and in vitro experiments, BRD4 upregulation was found to already occur during GPL, affecting macrophage polarization and epithelial cell cancerization. This finding provides an experimental basis for strategies targeting BRD4 inhibition at this critical stage.

Synthesis and biological studies of 4′, 7, 8-trihydroxy-isoflavone metal complexes

Li-Jun Tang,Xiang Chen,Yu-Na Sun,Jia Ye,Jing Lu,Ying Han,Xing Jiang,Chan-Chan Cheng,Cheng-Cheng He,Pei-Hong Qiu,Xiao-Kun Li

A new series of complexes of a ligand 4′, 7, 8-trihydroxy-isoflavone with transition metal (zinc, copper, manganese, nickel, cobalt) and selenium have been synthesized and characterized with the aid of elemental analysis , IR, electron ionization mass spectrum (EI-MS) and 1 H NMR spectrometric techniques . The compounds were evaluated for their in vitro antibacterial activities and antitumor properties. The metal complexes were found to be more active than the free ligand. Investigation on the interaction between the complexes and calf-thymus DNA (CT DNA) showed that the absorbance of CT DNA increased and the maximum peak (λ max   =   260   nm) red-shifted, while the intensity of fluorescence spectra of Epstein-Bart DNA (EB-DNA) gradually weakened, which indicated that all of these metal complexes tightly combined with CT DNA.

Graphene–polyaniline composite film modified electrode for voltammetric determination of 4-aminophenol

Yang Fan,Jin-Hang Liu,Chun-Peng Yang,Meng Yu,Peng Liu

An electrochemical sensor based on graphene–polyaniline (GR–PANI) nanocomposite for voltammetric determination of 4-aminophenol (4-AP) is presented. The electrochemical behavior of 4-AP at the GR–PANI composite film modified glassy carbon electrode (GCE) was investigated by cyclic voltammetry . 4-AP exhibits enhanced voltammetric response at GR–PANI modified GCE. This electrochemical sensor shows a favorable analytical performance for 4-AP detection with a detection limit of 6.5   ×   10 −8   M and high sensitivity of 604.2   μA   mM −1 . Moreover, 4-AP and paracetamol can be detected simultaneously without interference of each other in a large dynamic range.

Super-efficient Reduction of 4-nitrophenol Using Raw Pelagic Clays as Catalysts

Peiping Zhang,Tongtong Liu,Xue Sun,Qing Liang,Wei Zhang,Weikun Ning,Wenqing Li,Xuefa Shi,Shiding Miao

Natural clays are often employed as substrates for heterogeneous catalysts. However, the direct use of raw clays as catalysts has received less research attention. The objective of the present study was to help fill this gap by investigating catalytic properties of raw pelagic clays (PC) collected from the Indian Ocean. The raw PC were discovered to be efficient catalysts in the reduction of 4-nitrophenol (4-NP) in the presence of NaBH4. The effects of parameters including pH values, dosages of PC, and initial concentration of 4-NP and NaBH4 on the conversion or degradation rate of 4-NP have been investigated. The 4-NP was observed to be completely degraded within 480 s under conditions of 0.10 mM 4-NP, 25.0 mM NaBH4, and 0.20 g/L PC at an initial pH value of 7.0. The apparent rate constant was evaluated to be 27.53 × 10–3 s–1. Unlike previous pseudo-first order kinetics experiments, the induction period and degradation stages were observed to occur simultaneously during the PC catalysis. The S-shaped kinetics for 4-NP conversion was found to be perfectly matched by Fermi's function, and the enzyme-like catalysis by PC was appointed to describe the kinetics. Species of Fe(III), Mn(IV), and Mn(III) in PC were found to be essential, and were partly reduced to Fe(0) and Mn(II) by NaBH4 in our reaction, contributing to rapid conversion of 4-NP to 4-aminophenol (4-AP). The raw PC was converted to magnetic PC (m-PC) particles, which made PC particles separate easily for cycling use. This discovery would also have applications in continuous flow-fluid catalysis.

4-Octyl itaconate ameliorates immune thrombocytopenia by modulating megakaryocyte autophagy and apoptosis

Yuying Chang,Yinglan Jin,Xi Chen,Xiaomin Zhang,Yaoyao Tian,Xinyu Gao,Xiushuai Dong,Wei Wang

Objective: This study aimed to investigate the effects of 4-Octyl itaconate (4-OI) on immune thrombocytopenia (ITP) mice model and elucidate the underlying mechanism.Methods: An ITP mouse model was established by intraperitoneal injection of the monoclonal antibody MWReg30 and treated by 4-OI with/without chloroquine (CQ). The mice were divided into four groups: Control, ITP, ITP+4-OI and ITP+4-OI + CQ. Platelet (PLT) content was detected and bone marrow megakaryocytes were quantified using Giemsa staining. Apoptosis was evaluated by TUNEL staining, protein expression of Bax and Bcl-2 in bone marrow tissues was detected by western blotting, and megakaryocyte apoptosis ratio was assessed by flow cytometry detection of CD61+ cells. Peripheral blood mononuclear cells (PBMCs) were isolated from peripheral blood, and the mRNA expression of LC3II, Becin-1, and SQSTM1 were detected by qRT-PCR; Immunofluorescence evaluated LC3II, Beclin-1, and SQSTM1 expression in bone marrow, as well as the ratios of CD41+Beclin-1+ and CD41+LC3II+ megakaryocytes.Results: Compared to the ITP group, 4-OI treatment significantly increased PLT counts, while reduced the spleen index and bone marrow megakaryocyte numbers. 4-OI also increased the apoptosis rate of megakaryocytes by increasing Bax protein expression and reducing Bcl-2 expression in the bone marrow. LC3II and Beclin-1 expression increased in PBMCs and bone marrow tissues, whereas SQSTM1 expression decreased. Megakaryocytes exhibited reduced LC3II and Beclin-1. The autophagy inhibitor chloroquine (CQ) suppressed all the 4-OI-induced effects.Conclusion: 4-OI ameliorated ITP-induced thrombocytopenia by modulating autophagy-related proteins in megakaryocytes, inducing autophagy, and promoting apoptosis.

Interleukin-4-Loaded Heparin Hydrogel Regulates Macrophage Polarization to Promote Osteogenic Differentiation

Yuhao Zhao,Xiaofei Feng,Zhenrui Zhao,Zhengdong Song,Wenji Wang,Haiyan Zhao

In bone tissue engineering, biological scaffolds are designed with structural and functional properties that closely resemble the extracellular environment, aiming to establish a microenvironment conducive to osteogenesis. Macrophages hold significant potential for promoting osteogenesis and modulating the biological behavior of tumor cells. Multiple coculture experiments of macrophages and osteoblasts have demonstrated that macrophage polarization significantly impacts osteogenesis. Therefore, exploring bone biomaterials that can modulate macrophage polarization holds great clinical significance. In this study, heparin was modified with maleimide and was used as a raw material to form a hydrogel with 4-am-PEG-SH. The compound was used to polarize macrophages and promote osteogenesis after combining with interleukin 4 (IL-4) by taking advantage of the electronegativity of heparin. The results revealed overexpressed M2 macrophage-related phenotypic genes and cocultivation with MC3T3-E1 cells demonstrated the osteogenesis-promoting effect of the loaded IL-4 heparin hydrogel. Previous research reported that hydrogel loaded with IL-4 can be used as a biomaterial for osteogenesis promotion. Heparin materials used in this paper are derived from clinically anticoagulant drugs and feature a simple operation. The synthesized hydrogel effectively binds cytokines, regulates macrophages to induce osteogenesis and has many potential clinical applications.

Vanadium-Catalyzed Synthesis of 4(3H)-Quinazolinones from Anthranilamides and Aryl Aldehydes

Dan Zhan,Tianbin Li,Xiaoping Zhang,Chuan Dai,Haidong Wei,Yuyu Zhang,Qingle Zeng

Catalytic reduction of 4-nitrophenol over graphene supported Cu@Ni bimetallic nanowires

Zhiqiang Xu,Xianhua He,Mingwei Liang,Lijuan Sun,Di Li,Kenan Xie,Li Liao

Catalytic reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) over high-performance non-noble metal catalysts is attracting intensive attention. Herein, we report a graphene supported Cu@Ni bimetallic nanowires catalyst by a facile liquid phase reduction method with the assistance of an external magnetic field. The morphology and structure of the composite are studied by SEM, TEM and XPS. The vibrating sample magnetometer (VSM) is used to analyze its magnetic properties . Owing to the synergistic effect of graphene and bimetallic nanowires, the catalyst shows superior catalytic performance and excellent stability. The results of catalysis exhibit an extraordinary rate constant (1.16 min −1 ) and activity factor (5.81 min −1  mg −1 ) at room temperature, which are much higher than a majority of non-noble metal catalysts, even noble metal catalysts. Also, compared with noble metal catalyst, the novel catalyst possesses ferromagnetism , which facilitates the separation of catalyst and reaction system, and guarantees recyclability. Moreover, a possible synergistic catalytic mechanism based on the fact that electron transfer between copper-nickel nanowires and graphene has been proposed. It is believed that the novel catalyst has a great importance for the application of nanowires in the field of catalysis.

Synthesis and Characterisation of Phosphazene Derivatives Containing Dioxybiphenyl and 4-Sulfanylquinazoline Groups

Xiang Jiang,Guo-Wei Yu,Zu-Guang Li,Shi-Peng Chu,Shen-Peng Wang

2,2-Dichloro-4,4,6,6-bis[spiro(2′,2″-dioxy-1′,1″-biphenylyl)]cyclotriphosphazene was synthesised from the reaction of hexachlorocyclotriphosphazene with biphenyl-2,2′-diol. 2,2-Bis(4-formylphenoxy)-4,4,6,6-bis[spiro(2′,2″-dioxy-1′,1″-biphenylyl)]cyclotriphosphazene was obtained from the reaction of 2,2-dichloro-4,4,6,6-bis[spiro(2′,2″-dioxy-1′,1″-biphenylyl)] cyclotriphosphazene with 4-hydroxybenzaldehyde. 2,2-Bis[4-(4-quinazolinone)phenoxy]-4,4,6,6-bis[spiro(2′,2″-dioxy-1′,1″-biphenylyl)]cyclotriphosphazene was synthesised from the reaction of 2,2-bis(4-formylphenoxy)-4,4,6,6-bis[spiro(2′,2″-dioxy-1′,1″-biphenylyl)]cyclotriphosphazene with anthranilamide in N,N-dimethylformamide. The novel cyclophosphazene derivatives were synthesised under mild conditions from the reaction of 2,2-bis[4-(4-quinazolinone)phenoxy]-4,4,6,6-bis[spiro(2′,2″-dioxy-1′,1″-biphenylyl)]cyclotriphosphazene with 4-chlorobenzenemethanethiol, p-thiocresol, 4-aminothiophenol, and 4-chlorothiophenol in the presence of p-toluenesulfonyl chloride via C-OH bond activation under mild conditions. All products were generally obtained in high yields. Their structures were characterised by HRMS, IR and 1H, 13C spectroscopy.