JOURNAL OF POLYMER SCIENCE
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2022
·Vol. 60
·期 9
·1492-1500
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IF 3.046
Shitong Ren,Fangjing Tian,Shaoheng Zhang,Weicong Zhou,Yonggang Du
Developing thermosets derived from renewable sources is of great importance. In this work, a fully bio-based benzoxazine monomer, 3,6-bis((3-(furan-2-ylmethyl)-3,4-dihydro-2 H -benzo[ e ][1,3]oxazin-6-yl)methyl)piperazine-2,5-dione (TCDPF), is conveniently synthesized from L-tyrosine cyclic dipeptide (TCDP), furfurylamine and paraformaldehyde. The chemical structure of TCDPF is confirmed by nuclear magnetic resonance spectroscopy and Fourier transform infrared spectroscopy (FT-IR) techniques. The curing behavior of TCDPF is investigated by differential scanning calorimetry and in situ FT-IR techniques. After temperature-programmed curing, the thermomechanical property and thermal stability of the resulting TCDPF polymer (PTCDPF) are evaluated by dynamic mechanical analysis and thermogravimetric analysis techniques, respectively. It is found that PTCDPF have excellent comprehensive performance such as high glass transition temperature ( T g = 322 °C), high thermal degradation temperature ( T 5% = 342 °C, T 10% = 395 °C in N 2 atmosphere), and high char yield (CY = 51.3% at 800 °C in N 2 atmosphere). The results demonstrate that L-tyrosine is a promising bio-based raw material for preparing high performance polybenzoxazines. Graphical
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PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY
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2022
·
IF 4.966
Xinyi Cai,Jinyi Chen,Xiaofei Wang,Haitao Gao,Binghan Xiang,Liyao Dong
Echinochloa crus-galli L . , a notorious weed in rice paddy fields , is usually kept under control by mefenacet application at the pre-emergence or early post-emergence stage. Due to continuous and repeated usage, E. crus-galli is developing resistance to mefenacet in China. Two putative resistant and one susceptible E. crus-galli populations were collected from paddy fields in Jiangsu Province to characterize their herbicide resistance . Compared with the susceptible population , the two mefenacet-resistant populations had 2.8- and 4.1-times greater pre-emergence resistance, and 10- and 6.8-times greater early post-emergence resistance to mefenacet. These mefenacet-resistant E. crus-galli populations also exhibited cross- or multiple-resistance to acetochlor , pyraclonil, imazamox, and quinclorac. However, when the glutathione S-transferase (GST) inhibitor 4-chloro-7-nitrobenzoxadiazole (NBD-Cl) was applied prior to post-emergence treatment, mefenacet resistance levels were reduced in both populations. Additionally, GST activity in vivo in one resistant population was much higher than the susceptible population after mefenacet application. The very long chain fatty acid elongases (VLCFAEs) from both mefenacet-resistant populations required much higher mefenacet concentration to inhibit their activity. The reduced sensitivity of VLCFAEs to mefenacet indicates the presence of a target-site resistance mechanism and induction of high GST activity may provide additional contribution to E. crus-galli mefenacet resistance through a non-target-site mechanism.
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JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2022
·Vol. 169
·期 4
·047514
·
IF 4.386
Qiwen Yu,Jing Chen,Jingpin Xu,Long Chen,Yanhua Song,Xiaoya Xie,Jinjiang Jin,Hong Liu,Jun Liu,Fengjiang Zhang,Xing Chen
Real-time detection of L-lactate is crucial in monitoring tissue oxygenation and organ metabolism in surgery patients during the perioperative period. Traditional commercial L-lactate detection techniques using bulky and expensive instruments are time-consuming, hindering timely feedback in the operating room. Herein, utilizing the modified screen-printed carbon electrode, a portable and user-friendly smartphone-based electrochemical biosensing system, integrated with a miniaturized potentiostat via wireless transmission, was successfully constructed for bedside detection of L-lactate. It has a wide sensing range from 0.05–10 mM and a low limit of detection (9.1 μM). Bland–Altman analysis shows an acceptable agreement with the values of a mean difference (0.114 ± 0.3482) between results obtained with the commercial blood gas analysis instrument and the developed portable system. Accordingly, the developed portable system exhibits a great potential in point-of-care testing owing to its portability and rapid response in L-lactate detection during perioperative monitoring.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2022
·
IF 8.025
Yajun Ren,Xiaohong Hu,Youhua Chen,Lei Liu,Rui Qu,Huidi Xu,Xiaofeng Song
Biodegradable shape-memory polymers (SMPs) which are functional materials with applicability for medicine devices are designed to acquire their therapeutically relevant shape and drug release after implantation. In the work, an amphiphilic polymer (PVAD) is synthesized by using polytetrahydrofuran (PTMG), vinyl acetate (VAc), acrylic acid (AA), tetramethyltetravinylcyclotetrasiloxane (D 4 vi ) as raw materials. PVAD encapsulating hydrophilic drug as switching phase and poly( l -lactide) (PLLA) as fixing matrix construct an SM system with the characteristic of “reservoir-matrix” drug release. The shape recovery ratio ( R r ) of medicated PVAD/PLLA reaches 99 % by heat-water stimulation. The effects of release temperature and SM on drug release are investigated. With the release temperature increasing, the medicated PVAD/PLLA accelerates drug release and shows burst release initially, while the drug release for the medicated PLLA changes slightly. The drug release rate goes up after 3 rounds of SM. The mechanism of SM system controlling drug release is put forward based on structural changes. The yield strength and elongation at break of medicated PVAD/PLLA are 29.8 MPa and 44.6 %, respectively. It opens up new perspectives for drug carrier matrices in Pharmaceutical Sciences.
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CARBOHYDRATE POLYMERS
·
2022
·
IF 10.723
Dan Liu,Wei Tang,Xiao-Jun Huang,Jie-Lun Hu,Jun-Qiao Wang,Jun-Yi Yin,Shao-Ping Nie,Ming-Yong Xie
Polysaccharides are important constituents in Dolichos lablab hull. Herein, pectin-glucuronoxylan complex from D. lablab hull designated as DLHP-3 ( D. lablab hull polysaccharide,) was prepared by ion exchange and gel permeation chromatography , and further characterized by acid degradation and enzymatic hydrolysis , methylation combined with GC–MS, NMR and MALDI-TOF-MS analysis. Both of pectin and glucuronoxylan regions were found in DLHP-3. The glucuronoxylan region consisted of a →4)-β-Xyl p -(1→ backbone with branches of α-Glc p A-(1→ substituted at O -2 site, and the ratio of xylose to glucuronic acid was about 5:1. Acetyl groups were mainly attached to O -3 site of →2,4)-β-Xyl p -(1→ residues. The main chain of pectin region could be represented by →4)-α-Gal p A-(1→4)-α-Gal p A-(1→ and →2)-α-Rha p -(1→4)-α-Gal p A-(1→ with partial methyl-esterification. The side chains were deduced to embrace arabinan and arabinogalactan linked to rhamnogalacturonan-I region. Pectin was probably covalently bound to glucuronoxylan. Our findings uncovered the molecular structure of pectin-glucuronoxylan complex from D. lablab hull.
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POLYMERS FOR ADVANCED TECHNOLOGIES
·
2021
·Vol. 33
·期 1
·154-162
·
IF 3.665
Qihao Sun,Yueshi Shen,Junge Wei,Zhuanzhuan Zhang,Baochang Zhang,Xiaofeng Song
A novel polyurethane containing phosphorus and nitrogen (PU) was synthesized and characterized with 1 H-NMR, FTIR, and GPC. It was served as flame retardant to blend with poly(L-lactide) (PLLA) through solution casting technique. PU particle dispersed in PLLA substrate irregularly and improved the crystallinity of PLLA. The initial decomposition temperature of PLLA composite was significantly lower, but char residue increased. Flame retardancy and mechanical properties of PU/PLLA blends were evaluated. When the blend ratio of PU/PLLA was 10 wt%, LOI was 26.8%, and UL94 test reached V-2 grade. The inflaming retarding mechanism was outlined. The tensile strength of PLLA blend was 42.8 MPa, while its elongation at break was only 2%. By adjusting PU and adding compatilizer, the balance between flame retardancy and good mechanical properties of PLLA would be controlled.
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ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Jinglei Liu,Wenbo Yuan,Caifeng Li,Mengmeng Cheng,Yan Su,Lijian Xu,Tianfei Chu,Shifeng Hou
A novel chiral separation membrane was fabricated by assembling l-cysteine (l-Cys)-modified graphene oxide sheets. l-Cys modification leads to an enantiomer separation membrane with an accessible interlayer spacing of 8 Å, which allows high solvent permeability. In the racemate separation experiments under isobaric conditions, the enantiomeric excess (ee) values of alanine (Ala), threonine (Thr), tyrosine (Tyr), and penicillamine (Pen) racemates in the permeation solution were 43.60, 44.11, 27.43, and 46.44%, respectively. In the racemate separation experiments under negative pressure, the separation performances of Ala, Thr, and Tyr were still maintained, and the enantiomeric excess (ee) values of the filtrate after separation were 56.80, 54.57, and 32.34%, respectively. These results indicate that the as-prepared GO-Cys membrane has a great practical value in the field of enantiomer separation.
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Nanoscale
·
2021
·Vol. 13
·期 17
·8174-8180
·
IF 7.79
Zehao Gu,Mengfan Lu,Kai Feng,Zhaoxia Jin
Cellulose nanocrystals (CNCs) are inherently right-handed nanostructures that originate from nature, showing chirality in their fibrils, bundles, and self-assembled films. However, the enantio-specific interaction between CNCs and other chiral molecules has not been explored so far. In this study, we first demonstrated a chirality-related difference in the composite films of cellulose nanocrystals and histidine with a D- or L-configuration. The distinction is not only presented in the self-assembled nanostructures of CNCs, optical properties, and the thermal decomposition of composites but also in the crystallization of the amino acid. We suppose that it might have originated from the packing of amino acids on the twisted surface of CNCs. The knowledge about the enantio-specific interaction between the chiral amino acid and polysaccharide nanostructure is of significant importance for developing a new strategy for enantiomeric separation.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2021
·
IF 6.953
Dan Liu,Wei Tang,Yue Xin,Ze-Xia Wang,Xiao-Jun Huang,Jie-Lun Hu,Jun-Yi Yin,Shao-Ping Nie,Ming-Yong Xie
Polysaccharides were extracted by hot water and alkali in sequence from Dolichos lablab L. hull, and further purified by ion-exchange and gel columns. Hot water extracted D. lablab hull polysaccharide (DLHP) was rich in glucuronoxylan and pectin, and alkali extracted polysaccharide (DLHAP) mostly embraced glucuronoxylan. The structures of purified glucuronoxylans from DLHP and DLHAP were mainly analyzed by HPAEC-PAD, methylation combined with GC–MS, NMR and SEC-MALLS. DLHP-1 was identified as acetylated glucuronoxylan containing →4)-β-Xyl p- (1→ backbone with substitution at O -2 site by α-Glc p A/4- O -methyl-α-Glc p A. The molar ratio of β-Xyl p to α-Glc p A was 6.9:1, and acetylation was mainly at O -3 site of β-Xyl p with acetylation degree of 21.5%. DLHP-1 and DLHP-2 had similar physicochemical properties, except for molecular weight ( M w ). DLHAP-1 was the non-methylated glucuronoxylan almost without acetylation, and it had the molar ratio of β-Xyl p to α-Glc p A of 5.6:1. Besides, DLHP-1 ( M w of 20.0 × 10 3 g mol −1 ) adopted semi-flexible chain, while DLHAP-1 ( M w of 15.4 × 10 3 g mol −1 ) showed flexible chain. These results provided a structural basis for study on polysaccharides from D. lablab hull, which was benefit for understanding biological activities and developing functional food or pharmaceuticals of D. lablab .
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DRUG DELIVERY
·
2021
·
IF 6.419
Jiali Li,Xue Jiang,Lihuan Shang,Zhen Li,Conglian Yang,Yan Luo,Daoyu Hu,Yaqi Shen,Zhiping Zhang
This study aimed to synthesize and characterize L-epigallocatechin gallate (EGCG) complexed Mn2+ nanoparticle (L-EGCG-Mn), a proof-of-concept pH-sensitive manganese core nanoparticle (NP), and compare its magnetic resonance (MR) properties with those of Gd-DTPA, both in vitro and in vivo. Reverse microemulsion was used to obtain the L-EGCG-Mn NPs. The physicochemical properties of L-EGCG-Mn were characterized using dynamic light scattering, transmission electron microscopy, and near-infrared fluorescence small animal live imaging. The in vitro relaxivity of L-EGCG-Mn incubated with different pH buffer solutions (pH = 7.4, 6.8, 5.5) was evaluated. The T1-weighted MR imaging (MRI) properties were evaluated in vitro using hypoxic H22 cells as well as in H22 tumor-bearing mice. Cytotoxicity tests and histological analysis were performed to evaluate the safety of L-EGCG-Mn. L-EGCG-Mn showed good biocompatibility, stability, pH sensitivity, and tumor-targeting ability. Moreover, when the pH was decreased from 7.4 to 5.5, the r1 relaxivity of L-EGCG-Mn was shown to gradually increase from 1.79 to 6.43 mM−1·s−1. Furthermore, after incubation with L-EGCG-Mn for 4 h, the T1 relaxation time of hypoxic H22 cells was significantly lower than that of normoxic H22 cells (1788 ± 89 vs. 1982 ± 68 ms, p=.041). The in vivo analysis showed that after injection, L-EGCG-Mn exhibited a higher MRI signal compared to Gd-DTPA in H22 tumor-bearing mice (p < .05). Furthermore, L-EGCG-Mn was found to have a good safety profile via cytotoxicity tests and histological analysis. L-EGCG-Mn has a good safety profile and pH sensitivity and may thus serve as a potential MRI contrast agent.
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ADVANCES IN POLYMER TECHNOLOGY
·
2020
·
IF 1.539
Yunlong Liu,Jie Guo,Zhuobing Xiao,Dazhao Peng,Ke Song
Separation and purification of active components from biomass by inorganic materials during the pretreatment process of hydrothermal conversion are studied in this work. The batch experiment results show that an initial solution pH of 6 favors chelerythrine adsorption, and the optimum adsorbent dosage is 2.0 g. The adsorption mechanism of ZSM-5 for chelerythrine is investigated by adsorption kinetics, isotherm adsorption models, and thermodynamics analysis. The results show that the kinetics data fit the pseudo-second-order model well (R2 = 0.9991), and the intraparticle diffusion model has 3 diffusion stages, preliminarily indicating that chemisorption plays a major role in the adsorption process, and the sorption mechanism includes intraparticle, external, and boundary diffusion. The adsorption isotherms agree well with the Langmuir model, indicating the occurrence of monolayer molecular adsorption during the adsorption process. Meanwhile, the maximum adsorption capacity is 2.327, 2.072, and 1.877 mg/g at different temperatures (288 K, 298 K, and 308 K), respectively. The thermodynamic data demonstrate that the adsorption process is exothermic and spontaneous in nature. These observed results clearly confirm that ZSM-5 has potential superior properties for the enrichment and purification of alkaloids during the pretreatment of biomass.
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CARBOHYDRATE POLYMERS
·
2019
·
IF 6.044
Jinyan Gu,Haihui Zhang,Jixian Zhang,Chaoting Wen,Haile Ma,Yuqing Duan,Yuanqing He
To ascertain the preliminary structural characteristics and biological activity of different fractions of polysaccharides from Sagittaria sagittifolia L. (SPCs) by ultrasonic assisted extraction (UAE), four new polysaccharides (SPC-60, SPC-70, SPC-80 and SPC-90) were successively fractionated by ethanol. The results implied that except for neutral sugar, four contained proteins and uronic acids in their structure, which were further confirmed by the ultraviolet and infrared spectra. Molecular weight and monosaccharide composition analysis exhibited that SPC-60 (52.0 kDa), SPC-70 (294.9 kDa), SPC-80 (230.6 kDa) and SPC-90 (229.4 kDa) were a neutral polysaccharide composed of rhamnose, arabinose, xylose, mannose, glucose and galactose with dramatically different mole ratios. In addition, SPC-70 exhibited stronger antioxidant activity in vitro than the other three components. SPCs could significantly promote macrophage proliferation, NO release and phagocytosis. Thus, these results provided a reference for applications of S. sagittifolia L. polysaccharides which would benefit the development of industry and agriculture.
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