SEPARATION AND PURIFICATION TECHNOLOGY
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2025
·
IF 9
Qinzheng Zhao,Tianyin Huang,Zihao Cang,Yonghai Gan,Bin Xu,Bingdang Wu
Preloading the flocs on the membrane surface is beneficial to enhance the removal of contaminants and alleviate membrane fouling in the membrane-filtration process, but the appropriate flocs and its mechanism of action need to be further clarified. The present study first focused on the flocs generated by titanium xerogel coagulant (TXC) with PFS and PACl as comparation. Three flocs were separately pre-loaded on the ultrafiltration membrane to explore their performance of removing four toxic heavy metals (As(III), As(V), Sb(III) and Sb(V)) and alleviating membrane fouling. Results showed that the flocs produced by TXC and PFS could adsorb toxic oxygenates continuously, and the removal performance of TXC flocs is better than that of PFS, while the removal performance of PACl flocs is limited. After long-term operation, the membrane fouling of pre-loaded TXC floc was minimal, and the irreversible fouling was 1/3 and 1/6 of that of PFS and PACl, respectively. Meanwhile, the backwash time was 2.0 and 2.2 times longer than PFS and PACl, respectively. The mechanism of membrane fouling alleviation by floc preloading was clarified by floc characterization and model calculations. According to the n value in the model after fitting, an intermediate blocking mechanism dominated with the larger and more loose flocs in TXC system (n = 1.54), while a complete pore blocking mechanism dominated in the PFS (n = 1.98) and PACl (n = 2.11) systems. The results demonstrated that preloading the TXC flocs were superior to that of PFS and PACl in the membrane-filtration process.
研究领域:
环境科学
·
水处理工程
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产品关联
DOI
高影响因子
Probiotics and Antimicrobial Proteins
·
2025
·
IF 4.4
Zhang Haipeng,Zhao Xiaoou,Wang Xiaoyu,Wang Xinyue,Gu Jinyang,Liu Zhongliang,Kong Lingcong,Chen Jingrui,Ma Hongxia
The widespread use of commercial antibiotics has led to the emergence of multidrug resistance in pathogenic bacteria, posing a significant threat to human health and underscoring the urgent need for alternative antimicrobial agents. In this study, a bacteriocin-producing strain, Bacillus velezensis FS-3 ( B. velezensis FS-3), was isolated from soil in Changbaishan, China. Fermentation conditions were optimized to enhance both bacteriocin activity and yield. A novel bacteriocin, PFS-3, was purified from B. velezensis FS-3 using hydrochloric acid precipitation, organic solvent extraction, and preparative reversed-phase high-performance liquid chromatography. Liquid chromatography-mass spectrometry/mass spectrometry analysis determined its molecular weight to be 929.16 Da, and amino acid sequencing of this peptide revealed eight amino acids (STYLFEGL). To date, the biological properties of PFS-3 have not been reported. We demonstrate here that PFS-3 exhibits low toxicity and remarkable stability under diverse conditions, including variations in temperature, pH, and the presence of metal ions or organic reagents. PFS-3 displayed broad-spectrum antimicrobial activity, with particularly strong activity against Gram-negative bacteria. Notably, its minimum inhibitory concentration against multidrug-resistant Escherichia coli B2 (MDR E. coli B2) was 16 μg/mL. Mechanistic investigations revealed that bacteriocin PFS-3 exerts bactericidal effects on MDR E. coli B2 by disrupting cardiolipin in the outer membrane of the cells. Furthermore, in vivo experiments demonstrated that PFS-3 significantly improved survival rates in infection models of MDR E. coli . In conclusion, PFS-3 is a newly identified bacteriocin with strong antibacterial activity, high stability, safety, and a favorable therapeutic index, highlighting its potential applications in the food industry and biopharmaceuticals for combating MDR E. coli infections.
研究领域:
微生物学
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抗生素耐药性
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生物制药
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食品科学
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传染病学
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产品关联
DOI
PubMed
高影响因子
POLYMER
·
2020
·
IF 4.231
Yufei Liu,Siyuan Jiang,Wei Yan,Jun Qin,Min He,Shuhao Qin,Jie Yu
Improving complexation at the interfaces and regulating the crystal transformation behaviors of polyamide 6 (PA6) composites with high mechanical and thermal properties are essential for the industrial applications of PA6. In this work, the effects of adding p (N-(4-F-phenylmaleimide)-alt-styrene) (PFS) on the crystal transformation, thermostability, thermal conductivity , and mechanical properties of PA6 were investigated and discussed systematically. The resu---lts from heat deflection temperature (HDT), dynamic mechanical analysis (DMA ) and thermal conductivity tests indicate that PFS greatly increases the HDT, glass-transition temperature ( T g ), and thermal conductivity of PA6. Simultaneously, when the content of PFS is 10%, the tensile strength and flexural moduli of PA6/PFS composites are increased by 10.5 and 17.8% compared with that of pure PA6, respectively. The results from differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) show that PFS induces the transformation of PA6 from γ to α crystals by interfacial complexation. This work offers a facile approach for producing materials with high thermal and mechanical performances that can be potentially used in automobiles, electronics, and related technologies.
研究领域:
材料科学
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高分子化学
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产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Jiali Tan,Ying Huang,Baoyan Chi,Zhenfeng Xiong,Weidong Zhou,Zhuo Yang,Kemei Zhou,Xiaoqing Ruan,Xinxin Duan,Mingzhu Wang,Jun Zhang
Inorganic coagulants are essential agents that can facilitate the sludge deep dewatering, but comprehensive comparative research of commonly used coagulants is lacking. The systematic comparison of six coagulants, including Ferric Chloride (FeCl 3 ), Polymeric Ferrous Sulfate (PFS), Ferrous Sulfate (Fe 2 (SO 4 ) 3 ), Aluminium Chloride (AlCl 3 ), Aluminium Sulfate (Al 2 (SO 4 ) 3 ), and Polymeric Aluminium Chloride (PAC) regarding their performance in conditioning sludge dewatering , physicochemical properties, the risk of heavy metals migration in sludge cake and the mechanism of sludge dewatering, was investigated. Within a dosage range of 20% dry solids (DS), the PFS and FeCl 3 showed a better dewatering effect among the six coagulants, and the water content (Wc) of the sludge cake decreased from 81.2%±1.1% to 57.7%±1.0% and 59.2%±1.6%, respectively. There was a correlation between the pH, zeta potential , viscosity, and bound water content of the sludge and the Wc of the sludge cake during dewatering conditioned by six coagulants. However, there was no correlation between sludge particle size and Wc of the sludge cake. The PFS and FeCl 3 reduced the protein content of tightly bound extracellular polymeric substances (TB-EPS) by 66.1% and 62.6%, respectively. Moreover, the iron coagulants significantly reduced the content of As, Cu, Ni, and Zn in the sludge cake, where the risk levels of As and Ni were largely weakened. The economic analysis shows that iron coagulants were more valuable than aluminium coagulants for engineering applications. Meanwhile, the dewatering mechanisms of the two types of coagulants were revealed. This study provides significant insights into the application of coagulants in engineering practice.
研究领域:
环境科学
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污水处理
✓ 已验证
DOI
高影响因子
Nano Today
·
2021
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IF 20.722
Meng Lin,Zhenzhen Yang,Yiliang Yang,Yiwei Peng,Jiajia Li,Yitian Du,Qi Sun,Datong Gao,Quan Yuan,Yu Zhou,Xinyi Chen,Xianrong Qi
Tumor-associated macrophages (TAMs) are abundant in the tumor microenvironment and promote the tumor progression via multiple mechanisms. CD47 is overexpressed in most malignant tumors and acts as a “don’t eat me” signal to inhibit phagocytosis . We utilized CRISPR/Cas9 technology to knock out CD47 to guarantee the long-lasting anti-tumor immune responses. However, the reprogrammed TAMs are vulnerable to the inhibitory cytokines and tend to be transformed back into TAMs, and CD47 blockade alone may not be sufficient to elicit effective immune responses. We combined CD47 blockade with an immune-activating cytokine IL-12 for synergistic anti-tumor efficacy by genetically engineering the tumor cells into factories of IL-12 to in situ reprogram TAMs. Firstly, we designed a selective responsiveness accelerated gene delivery system named HPT-PFs that was dual modified with hyaluronic acid (HA) and tumor microenvironment sensitive peptides (TMSP) to simultaneously deliver plasmids for CD47 knockout and IL-12 production. Due to tumor-specific transfection and excellent endosome escape ability of HPT-PFs vector, more than 27% of tumor cells lost CD47 expression after HPT-PFs mediated gene editing, thus eliciting the phagocytosis by macrophages. And higher than 500 ng/ml of IL-12 was produced by tumor cells after HPT-PFs mediated pIL-12 expression, indicating the successful engineering of tumor cells into factories of IL-12. In melanoma-bearing mice models, drastic elevation of M1-polarized TAMs and secretion of inflammatory cytokines were observed when combined CD47 knockout with IL-12 production, which led to significant inhibition of tumor growth. Our study suggested that combination of CRISPR-mediated CD47 blockade with IL-12 production in tumor cells could synergistically promote macrophage-mediated immunotherapy, paving the way for CRISPR-based in situ engineering tumor cells for effective immunotherapy.
研究领域:
癌症生物学
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免疫学
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基因治疗
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生物技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2018
·Vol. 53
·期 15
·10784-10797
·
IF 2.993
Bo Caiying,Hu Lihong,Chen Yong,Yang Xiaohui,Zhang Meng,Zhou Yonghong
A novel phosphorus-containing cardanol (PCC) derived from cardanol—a renewable meta -substituted phenol and harmful by-product of the cashew industry—in combination with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) was used to produce bio-based phenolic foams (PFs). The properties of the PFs were then characterized in detail. The PCC was fully characterized by using Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance ( 1 H NMR), while the thermal degradation was studied and monitored by thermogravimetry coupled to FTIR (TGA/FTIR) and TGA coupled with mass spectrometry (TGA/MS). It was found that PCC exhibited high thermal stability. The total heat release, peak heat release rate and mean heat release rate of PF containing 4% PCC decreased by 13.55, 33.43 and 13.42%, respectively, in comparison with pristine PF. The enhanced flame-retardant behavior was attributed to the free radicals PO· produced during combustion, which captured free radicals in the gas phase; moreover, the phosphaphenanthrene group may create a char residue barrier against the further combustion of the polymer. Meanwhile, bio-based PFs showed excellent mechanical properties, as the compressive and flexural strength of PF with 4% PCC increased by 79.59 and 20.98%, respectively, in comparison with pristine PF. The pulverization ratio of bio-based PFs was reduced with the increase in PCC content. The findings in this study demonstrate that PCC could be used as a phenol substitute in the synthesis of PFs to overcome their intrinsic brittleness and high flammability.
研究领域:
材料科学
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化学工程
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可持续化学
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高分子科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）