JOURNAL OF APPLIED POLYMER SCIENCE
·
2012
·
IF 1.289
Di Zhao,JianFeng Xu,Lu Wang,JianJia Du,KeDong Dong,CaiFei Wang,XiangDong Liu
Two phosphorylated chitosan derivatives with a similar degree of substitution of about 0.5 were synthesized via either the esterification of chitosan's hydroxyl groups by P 2 O 5 in methanesulfonic acid or the selective incorporation of methylene phosphonic groups on chitosan's amino groups by formaldehyde/H 3 PO 3 in water. The performances of the resulting O -phosphorylated chitosan (OPC) and N -methylene phosphonic chitosan (NMPC) as amphoteric flocculants were assessed in comparison with that of unmodified chitosan. In turbidity removal experiments using kaolin suspensions in water, OPC removed about 90% turbidity, but NMPC only removed 60%. The lower flocculation efficiency of NMPC was attributed to the decreased acid strength of the N -methylene phosphate groups in NMPC. These results revealed that the acidity of the phosphate groups introduced in the modified chitosans is an important factor with regard to the flocculation efficiency, and consequently that O-phosphorylation is more suitable than N-phosphorylation for preparing chitosan-based amphoteric flocculants. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
研究领域:
材料科学
·
环境科学
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DOI
高影响因子
GREEN CHEMISTRY
·
2023
·Vol. 25
·期 13
·5041-5050
·
IF 9.8
Xue Gao,Lei Zhang,Mei Cui,Renliang Huang,Wei Qi,Rongxin Su
Phosphorylated cellulose nanocrystals (P-CNCs) are important derivatives of cellulose nanocrystals (CNCs), which have attracted much attention in food, cosmetics and biomedicines. However, the lack of suitable industrial manufacturing technology impedes the commercial application of P-CNCs. Here, we report a facile and green process combining pre-phosphorylation with mechanical fibrillation for P-CNC production. The pre-phosphorylation process was optimised to reduce raw material and energy consumption and improve the quality of P-CNCs, and the corresponding environmental performances were further evaluated by life cycle assessment (LCA). P-CNCs with high charge content (2.33 mmol g−1) and high crystallinity (87.3%) were obtained efficiently under an optimal molar ratio (cellulose biomass : NH4H2PO4 : urea) of 1 : 0.3 : 1.2 by curing at 150 °C for 30 min and showed superior flame retardant performance. Furthermore, compared with the present production processes based on in situ phosphorylation and post-phosphorylation, this facile process exhibited not only better environmental performance but also superior economic performance, as the LCA and economic evaluation results revealed. Therefore, this eco-efficient process exhibits great potential in the industrial production of P-CNCs.
研究领域:
材料科学
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环境科学
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化学工程
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产品关联
DOI
高影响因子
ORGANIC & BIOMOLECULAR CHEMISTRY
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2020
·Vol. 18
·期 42
·8709-8715
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IF 3.412
Ling Xu,Yan Zhang,Yi-Ming Li,Xian-Fu Lu
As an autophagic adaptor, p62 specifically targets ubiquitinated proteins to an autophagosome for lysosomal degradation through a critical ubiquitin-associated (UBA) domain. Recent research studies reported that the Ser403 and Ser407 sites on the UBA domain were modified by phosphorylation, increasing the binding affinity between p62 and ubiquitin (Ub). However, the exact role of each phosphorylation site in the regulation of the UBA domain and Ub binding remains unclear. In this text, we applied total chemical synthesis to prepare four types of phosphorylated UBAs, among which the bisphosphorylated UBA was successfully synthesized via the pseudo-dipeptide unit and auxiliary-mediated hydrazide-based native chemical ligation (NCL). Isothermal titration calorimetry (ITC) assays showed that the phosphorylation at S407 enhanced the binding affinity between UBA and Ub, while that at S403 did not. It was suggested that phosphorylation at S407 might be important for promoting the interplay between the UBA domain and Ub, whereas phosphorylation at S403 was not directly involved in this interaction.
研究领域:
生物化学
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分子生物学
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产品关联
DOI
PubMed
高影响因子
Frontiers in Pharmacology
·
2021
·
IF 5.811
Yang Siwen,Qu Yunhe,Chen Jiyu,Chen Si,Sun Lin,Zhou Yifa,Fan Yuying
Insufficient pancreatic β-cell or insulin-producing β-cell are implicated in all types of diabetes mellitus. Our previous studies showed bee pollen polysaccharide RBPP-P improves insulin resistance in type 2 diabetic mice by inhibiting liver fat deposition. However, its potential of regulating β-cell function and integrity is not fully known. Herein, we observed that β-cell proliferation (n = 10), insulin synthesis (n = 5, p = 0.01684) and insulin incretion (n = 5, p = 0.02115) were intensely activated in MIN6 cells when treatment with RBPP-P. In alloxan-induced diabetic mice, oral administration of RBPP-P (n = 10) effectively decreased the blood glucose (p = 0.0326), drink intake (p < 0.001) and urine (p < 0.001). It directly stimulated phosphorylation of p38 (p = 0.00439), ERK (p = 0.02951) and AKT (p = 0.0072) to maintain the islet function and mass. Thus, our data suggest that RBPP-P is a natural compound to regulate β-cell proliferation and function, indicating it might have therapeutic potential against type 1 diabetes.
研究领域:
药理学
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内分泌学
·
糖尿病研究
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF INDUSTRIAL MICROBIOLOGY & BIOTECHNOLOGY
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2022
·Vol. 49
·期 3
·
IF 4.258
Wang Lei,Zheng Peng,Hu Meirong,Tao Yong
Cellobiose, a natural disaccharide, attracts extensive attention as a potential functional food/feed additive. In this study, we present an inorganic phosphate (Pi) self-sufficient biotransformation system to produce cellobiose by co-expressing sucrose phosphorylase (SP) and cellobiose phosphorylase (CBP). The Bifidobacterium adolescentis SP (BASP) and Cellvibrio gilvus CBP (CGCBP) were co-expressed in Escherichia coli. Escherichia coli cells containing BASP and CGCBP were used as whole-cell catalysts to convert sucrose and glucose to cellobiose. The effects of reaction pH, temperature, Pi concentration, and substrate concentration were investigated. In the optimum biotransformation conditions, 800 mM cellobiose was produced from 1.0 M sucrose, 1.0 M glucose, and 50 mM Pi, within 12 hr. The by-product fructose and residual substrate (sucrose and glucose) were efficiently removed by treatment with yeast, to help purify the product cellobiose. The wider applicability of this Pi self-sufficiency strategy was demonstrated in the production of laminaribiose by co-expressing SP and laminaribiose phosphorylase. This study suggests that the Pi self-sufficiency strategy through co-expressing two phosphorylases has the advantage of great flexibility for enhanced production of cellobiose (or laminaribiose).
研究领域:
生物技术
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生物化学
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微生物学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF POLYMER RESEARCH
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2020
·Vol. 27
·期 10
·1-11
·
IF 2.426
Haq Fazal,Yu Haojie,Wang Li,Liu Jian,Mehmood Sahid,Haroon Muhammad,Amin Bilal-Ul,Fahad Shah,Uddin Md Alim
In this article, starch phosphate- g -poly (methacrylic acids) (SP- g -PMAAs) were synthesized by dual modification. Firstly starch phosphate (SP) was synthesized by phosphorylation of native starch (NS) with mono sodium-phosphate and di sodium-phosphate. Afterwards, methacrylic acid (MAA) was grafted onto SP via free radical polymerization to synthesize SP- g -PMAAs. The structure of the SP and SP- g -PMAAs was investigated by phosphorus nuclear magnetic resonance, proton nuclear magnetic resonance and fourier-transform infrared spectroscopy. The X-ray diffraction studies showed that the modification diminished the crystalline nature of SP and SP- g -PMAAs. The SEM images showed spherical or polyhedral smooth surface for the starch. After modification, SP and SP- g -PMAAs exhibited distorted and rougher surfaces which are assumed to be good for adsorption. The dual modification produced phosphate and carboxylic groups on the starch backbone. The phosphate and carboxylic groups have high tendency to make hydrogen bonding with phenol. The comparative adsorption studies of NS, SP and SP-g-PMAAs were checked for phenol. The experimental results showed adsorption efficiencies of 0.022 g/g, 0.082 g/g, 0.100 g/g, 0.148 g/g and 0.151 g/g for NS, SP, SP- g -PMAA1, SP- g -PMAA2 and SP- g -PMAA3, respectively. The following findings revealed that dual modification enhanced the adsorption ability of NS.
研究领域:
材料科学
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环境科学
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DOI
高影响因子
ACS Catalysis
·
2018
·
IF 11.384
Dongdong Meng,Xinlei Wei,Yi-Heng P. Job Zhang,Zhiguang Zhu,Chun You,Yanhe Ma
Cellulosic biomass is the earth’s most abundant renewable resource, which is considered to be a promising feedstock for manufacturing biofuels and biochemicals. In this study, stoichiometric enzymatic phosphorolysis of cellulosic biomass for manufacturing biochemicals or biofuels by in vitro synthetic enzymatic biosystems was designed. Three cascade phosphorolytic enzymes, cellodextrin phosphorylase, cellobiose phosphorylase, and polyphosphate-dependent glucokinase, were used for the biotransformation of cellodextrins to high-energy phosphorylated sugars (that is, glucose 1-phosphate and glucose 6-phosphate). A series of downstream exergonic reactions then converted these high-energy phosphorylated sugars into myo-inositol, resulting in a near-stoichiometric conversion of cellodextrins with a high product yield of 98% (w/w). Moreover, this enzymatic biosystem can even work for the acid-treated biomass hydrolysate containing microorganism-toxic compounds. The construction of this in vitro synthetic enzymatic biosystem provided an alternative method for the utilization of cellulosic biomass rather than cellulolytic enzyme hydrolysis to fermentative monomeric sugars followed by microorganism fermentation, showing potentials in the production of biocommodities such as hydrogen, rare sugars, and electricity from cellulosic biomass.
研究领域:
生物技术
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生物化学
·
可再生能源
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产品关联
DOI
高影响因子
eLife
·
2025
·
IF 0
Cong Chen,Tong-Yao Gao,Hua-Wei Yi,Yi Zhang,Tong Wang,Zhi-Ling Lou,Tao-Feng Wei,Yun-Bi Lu,Tingting Li,Chun Tang,Wei-Ping Zhang
Ubiquitin (Ub), a central regulator of protein turnover, can be phosphorylated by PINK1 (PTEN-induced putative kinase 1) to generate S65-phosphorylated ubiquitin (pUb). Elevated pUb levels have been observed in aged human brains and in Parkinson’s disease, but the mechanistic link between pUb elevation and neurodegeneration remains unclear. Here, we demonstrate that pUb elevation is a common feature under neurodegenerative conditions, including Alzheimer’s disease, aging, and ischemic injury. We show that impaired proteasomal activity leads to the accumulation of sPINK1, the cytosolic form of PINK1 that is normally proteasome-degraded rapidly. This accumulation increases ubiquitin phosphorylation, which then inhibits ubiquitin-dependent proteasomal activity by interfering with both ubiquitin chain elongation and proteasome-substrate interactions. Specific expression of sPINK1 in mouse hippocampal neurons induced progressive pUb accumulation, accompanied by protein aggregation, proteostasis disruption, neuronal injury, neuroinflammation, and cognitive decline. Conversely, Pink1 knockout mitigated protein aggregation in both mouse brains and HEK293 cells. Furthermore, the detrimental effects of sPINK1 could be counteracted by co-expressing Ub/S65A phospho-null mutant but exacerbated by over-expressing Ub/S65E phospho-mimic mutant. Together, these findings reveal that pUb elevation, triggered by reduced proteasomal activity, inhibits proteasomal activity and forms a feedforward loop that drives progressive neurodegeneration.
研究领域:
神经科学
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生物化学
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分子生物学
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神经退行性疾病
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细胞生物学
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产品关联
DOI
PubMed
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
·
2024
·
IF 1.5
Gado Mohamed A.
(Pyridine-2,5-diylbis(azaneylylidene)) bis-(methaneylylidene)) bis(benzene-5,1,3-triyl) tetrakis (hydrogen phosphonate) (PZMB) was successfully synthesized for Th(IV) and Ce(IV) adsorption, the adsorption parameters evaluated and found to be pH 3.5, time 60 min, dose 0.15 g. Adsorption kinetics, isotherm, and thermodynamics studies. Adsorption kinetics studies show that adsorbent follow pseudo-second-order model while isotherm studies conclude that adsorption processes fitted Langmuir and D-R isotherm model. The maximum adsorption capacity of BZMB of Th(IV) and Ce(IV) are 366.4 and 244.53 mg/g respectively, Thermodynamic studies indicate both adsorption processes exhibited by the PZMB were endothermic, spontaneous and sorption occurs in a random manner.
研究领域:
化学工程
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环境科学
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产品关联
DOI
高影响因子
Cell Metabolism
·
2023
·
IF 29
Qianmin Ou,Xinhua Qiao,Zhengshi Li,Luhan Niu,Fangcao Lei,Ruifeng Cheng,Ting Xie,Ning Yang,Yao Liu,Ling Fu,Jing Yang,Xueli Mao,Xiaoxing Kou,Chang Chen,Songtao Shi
Summary Over 50 billion cells undergo apoptosis each day in an adult human to maintain immune homeostasis. Hydrogen sulfide (H 2 S) is also required to safeguard the function of immune response. However, it is unknown whether apoptosis regulates H 2 S production. Here, we show that apoptosis-deficient MRL/ lpr (B6.MRL-Faslpr/J) and Bim −/− (B6.129S1-Bcl2l11tm1.1Ast/J) mice exhibit significantly reduced H 2 S levels along with aberrant differentiation of Th17 cells, which can be rescued by the additional H 2 S. Moreover, apoptotic cells and vesicles (apoVs) express key H 2 S-generating enzymes and generate a significant amount of H 2 S, indicating that apoptotic metabolism is an important source of H 2 S. Mechanistically, H 2 S sulfhydrates selenoprotein F (Sep15) to promote signal transducer and activator of transcription 1 (STAT1) phosphorylation and suppress STAT3 phosphorylation, leading to the inhibition of Th17 cell differentiation. Taken together, this study reveals a previously unknown role of apoptosis in maintaining H 2 S homeostasis and the unique role of H 2 S in regulating Th17 cell differentiation via sulfhydration of Sep15 C38 .
研究领域:
免疫学
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细胞生物学
·
生物化学
✓ 已验证
DOI
PubMed
高影响因子
Journal of Inflammation Research
·
2021
·
IF 6.922
Zhen-Hua Ying,Hui-Min Li,Wen-Ying Yu,Chen-Huan Yu
Purpose Abnormal glycolysis of immune cells contributed to the development of inflammatory response. Inhibition of this Warburg phenotype could be a promising strategy for preventing various inflammatory diseases. Iridin (IRD) is a natural isoflavone, and exerts anticancer, antioxidant, and anti-inflammatory effects. However, the underlying mechanism of IRD on acute inflammation remains unknown. In this study, the protective effects of IRD against lipopolysaccharide (LPS)-induced inflammation were investigated in murine macrophage RAW264.7 cells and in mice. Methods The inhibition of IRD on NO production in culture medium was detected by Griess assay while the levels of TNF-α, IL-1β, and MCP-1 were detected by ELISA assay. The effects of IRD on OCR and ECAR levels in LPS-treated macrophages were monitored by using Seahorse Analyzer. The apoptosis rate as well as the release of ROS and NO of RAW264.7 cells were analyzed by flow cytometric assay. The protective effects of IRD were investigated on LPS-induced inflammation in mice. The expressions of PKM2 and its downstream (p-JAK1, p-STAT1, p-STAT3, p-p65, iNOS, and COX2) in cells and in lung tissues were detected by Western blotting analysis. Results IRD treatment at the concentrations of 12.5–50 μM significantly inhibited the productions of TNF-α, IL-1β, MCP-1, and ROS, and suppressed the levels of glucose uptake and lactic acid in LPS-treated RAW264.7 cells. Oral administration with IRD (20–80 mg/kg) inhibited LPS-induced acute lung injury as well as inflammatory cytokine production in mice. Moreover, IRD targeted pyruvate kinase isozyme type M2 (PKM2) and suppressed its downstream p-JAK1, p-STAT1, p-STAT3, p-p65, iNOS, and COX2, which could be abolished by PKM2 agonist DASA-58 and antioxidant N-acetyl-L-cysteine, but partly be reversed by NF-κB activator CUT129 and JAK1 activator RO8191. Conclusion IRD alleviated LPS-induced inflammation through suppressing PKM2-mediated pathways, and could be a potential candidate for the prevention of inflammatory diseases.
研究领域:
药理学
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免疫学
·
细胞生物学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2024
·Vol. 141
·期 14
·e55192
·
IF 2.7
Jing-Fang Zhang,Ren-Cheng Tang
Kapok fiber (KF) with a naturally hollow structure has found an increasing application in filling and composite materials, most of which have a demand of flame retardancy. To realize this high-value utilization, KF was phosphorylated by a reactive phosphorus- and nitrogen-containing flame retardant for enhanced fire safety. The flame retardant was first synthesized by the reaction of urea and diethylene triamine pentakis (methyl phosphonic acid) (a commercially available scale inhibitor) with low cost, and then, applied in the phosphorylation of KF in the presence of dicyandiamide. In thermogravimetric analysis, phosphorylated KF showed 38.1% residue weight in nitrogen and 10.2% residue weight in air at 700°C, whereas the residue weight of KF was 8.4% in nitrogen and 1.5% in air. In microcalorimetric analysis, the heat release capacity and total heat release of phosphorylated KF displayed a reduction of 81% and 55%, respectively. In vertical combustion test, phosphorylated KF was difficult to ignite and had no afterburning or smoldering. The tests indicated that phosphorylated KF had excellent charring properties, low heat release, and good flame retardancy. This work suggests a promising strategy of enhancing the flame retardancy of KF and increasing its applicability in filling and composite materials.
研究领域:
材料科学
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化学工程
✓ 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）