RSC Advances
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2019
·Vol. 9
·期 35
·20044-20052
·
IF 3.049
Tianyu Liu,Dandan Chen,Feng Yang,Jinyao Chen,Ya Cao,Ming Xiang,Jian Kang,Ruizhang Xu
The application of a reverse osmosis (RO) membrane is greatly restricted on account of a trade-off between water flux and salt rejection, as well as poor anti-fouling properties. In order to improve the surface hydrophilicity of RO membranes, L-lysine (Lys) was grafted onto polyamide selective layers with the premise of maintaining the original surface morphology and thickness, which were verified through scanning electron microscopy and atomic force microscopy analysis. X-ray photoelectron spectroscopic measurements confirmed the occurrence of the reaction. After modification, the RO membranes exhibited notably enhanced hydrophilicity due to a steep decline in their water contact angles. The results of cross-flow filtration tests manifested that the modified membranes showed evident enhancements in water flux and salt rejection. For the optimized samples, the water flux increased by 22.45% compared with the pristine membrane, and the salt rejection rose up to 98.53% from the initial value of 95.44%. After grafting, the RO membranes performed much better in fouling resistance, especially towards protein and cationic foulants. The mechanism of how grafted Lys affected the performance of the RO membranes was analyzed. This research provides a feasible method to optimize the performance of RO membranes.
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CHEMOSPHERE
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2019
·
IF 5.108
Luyao Zhang,Li Chen,Zhiyuan Meng,Wenjun Zhang,Xin Xu,Zikang Wang,Yinan Qin,Yue Deng,Rui Liu,Zhiqiang Zhou,Jinling Diao
Reptiles, the most diverse taxon of terrestrial vertebrates, might be particularly vulnerable to soil pollution. Reptiles especially lizards have been rarely evaluated in ecotoxicological studies, and there is a very limited report for effects of soil pesticide contaminants on lizards. In this study, male and female lizards ( Eremias argus ) were exposed to Glufosinate-ammonium (GLA) and l - Glufosinate-ammonium (L-GLA) for 60 days. Slower sprint speed, higher frequency of turning back and reduced brain index were observed in treatment groups. The accumulation of GLA in the brain of lizard was higher than that of L-GLA. Moreover, the activities of neurotoxicity-related enzymes and biomarkers of oxidative stress were also investigated. In summary, the neurotoxic effects of lizards have been observed after exposure to GLA and L-GLA. Based on the result of the Integrated Biomarker Response (IBR), males were more sensitive to contaminants than females. On the other hand, the neurotoxic pathways by GLA and L-GLA triggered were slightly different: GLA mainly acted on glutamine synthetase (GS), acetylcholinesterase (AchE) and Catalase (CAT) and L-GLA aimed at AchE, Na + /K + -ATPase, Superoxide dismutase (SOD) and Malondialdehyde (MDA). In summary, the accumulation of GLA and L-GLA in lizard's brain induced neurotoxicity by altering the levels of enzymes related to nervous system and antioxidant activity and further resulted in the decrease of brain index and locomotor performance.
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INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY
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2019
·
IF 3.618
Xiao-Jin Pei,Nan Chen,Yu Bai,Jian-Wen Qiao,Sheng Li,Yong-Liang Fan,Tong-Xian Liu
Insect cuticular hydrocarbons (CHCs), the evolutionary products of aquatic hexapod ancestors expanding to terrestrial environment, are deposited on the surface of insect integument and originally functioned primarily as waterproofing agents. CHCs are derived from the conserved fatty acid synthesis pathway in insects. However, the pivotal fatty acid synthase (FAS) involved in hydrocarbon (HC) biosynthesis remains unknown in many insect orders including the primitive Blattodea . Here, we investigated functional FAS genes that modulate cuticular lipid biogenesis in the German cockroach , Blattella germanica (L.). Based on our full-length transcriptomic data and the available genomic data, seven FAS genes ( BgFas1–7 ) were identified from B. germanica . Tissue-specific expression analysis revealed that BgFas1 , BgFas3 , BgFas4 and BgFas7 were highly expressed in the integument, whereas BgFas2 was dominantly expressed in the fat body. BgFas5 /6 mRNA was almost negligible in the tested tissues. Systemic RNAi screen was performed against BgFas1–7 , we found that only RNAi knockdown of BgFas1 caused a dramatic reduction of methyl-branched HCs (mbHCs) and a slight decrease of straight-chain HCs (scHCs) for both internal and external HCs. Significant reduction of cuticular free fatty acids (cFFAs) was also detected within BgFas1 -repressed cockroaches, while repression of CYP4G19 resulted in dramatic increase of cFFAs. Moreover, we found that BgFas1 mRNA levels were correlated with insect molting cycles, and could be induced by long-term mild dryness treatment. Furthermore, desiccation assay revealed that BgFas1 suppression accelerated water loss and led to early death of cockroaches under desiccation. Our results indicate that BgFas1 is necessary for both HC and cFFA biosynthesis in B. germanica . In addition, our study also confirms that cuticular lipids, particularly mbCHCs, are critical for desiccation resistance in B. germanica .
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ACS Applied Bio Materials
·
2019
·
IF 0
Jingyuan Ma,Peizhi Yu,Boru Xia,Yuxiu An,Zhiqiao Wang
We synthesized a biodegradable and environmentally friendly shale inhibitor based on chitosan-grafted l-arginine (CA) for wellbore stability in shale formation. The structure of CA was characterized by Fourier-transform infrared spectroscopy. Linear swelling, shale hot-rolling recovery, shale inhibition durability, and sedimentation experiments were used to evaluate the inhibition properties of CA and compared with the commonly used inhibitors potassium chloride (KCl) and polyamines (HPA and SIAT). The results showed that the inhibition of CA was better than that of KCl, HPA, and SIAT and that it can have a shale hot-rolling recovery of more than 90% at 150 °C, which indicated that CA had higher temperature resistance and longer durability. More importantly, it can be biodegraded as exhibited by the biodegradibility experiment. The inhibition mechanism of CA was studied by particle size distribution, X-ray diffraction, scanning electron microscopy, zeta potential analysis, and contact angle test. The strong inhibition of CA can be attributed to its encapsulation of MMT and shale surfaces. The CA with strongly positively charge was firmly adsorbed on the surface of MMT and shale, which not only neutralized the negative charge of MMT, compressed the diffused electric double layer, but also increased the contact angle of MMT and shale surface which enhancing hydrophobicity of MMT and shale. The hydration swelling and dispersion of MMT and shale were further inhibited. In addition, compatibility experiments showed that CA was compatible with commonly used treatment agents. CA did not affect the rheology of water-based drilling fluids and can reduce fluid loss after aging.
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INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
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2018
·Vol. 19
·期 8
·2364
·
IF 3.687
Xiwu Qi,Hailing Fang,Xu Yu,Dongbei Xu,Li Li,Chengyuan Liang,Hongfei Lu,Weilin Li,Yin Chen,Zequn Chen
Mentha canadensisL. has important economic value for its abundance in essential oils. Menthol is the main component ofM. canadensisessential oils, which is certainly the best-known monoterpene for its simple structure and wide applications. However, the regulation of menthol biosynthesis remains elusive inM. canadensis. In this study, transcriptome sequencing ofM. canadensiswith MeJA treatment was applied to illustrate the transcriptional regulation of plant secondary metabolites, especially menthol biosynthesis. Six sequencing libraries were constructed including three replicates for both control check (CK) and methyl jasmonate (MeJA) treatment and at least 8 Gb clean bases was produced for each library. After assembly, a total of 81,843 unigenes were obtained with an average length of 724 bp. Functional annotation indicated that 64.55% of unigenes could be annotated in at least one database. Additionally, 4430 differentially expressed genes (DEGs) with 2383 up-regulated and 2047 down-regulated transcripts were identified under MeJA treatment. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment indicated that “Monoterpenoid biosynthesis” was one of the most significantly enriched pathways in metabolism. Subsequently, DEGs involved in JA signal transduction, transcription factors, and monoterpene biosynthesis were analyzed. 9 orthologous genes involved in menthol biosynthesis were also identified. This is the first report of a transcriptome study ofM. canadensisand will facilitate the studies of monoterpene biosynthesis in the genusMentha.Keywords:Mentha canadensisL.;transcriptome sequencing;JA signaling;transcription factors;menthol biosynthesis
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JOURNAL OF ELECTROANALYTICAL CHEMISTRY
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2018
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IF 3.235
Danyu He,Pu Zhang,Shehong Li,Hongxia Luo
A novel free-standing graphene platform electrode (GPE) was prepared directly by transferring a chemical vapor deposition (CVD) graphene film from Cu foils to polyethylene terephthalate substrates with the aid of polymethyl-methacrylate. AuPt hybrid nanoparticles (AuPtNPs) and l -cysteine ( l -Cys) were electrodeposited simultaneously on the GPE. The successful formation of AuPtNPs-Cys/GPE was confirmed by scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), Raman microscope and X-ray diffraction (XRD). The electrocatalytic activity and enhanced conductivity of AuPtNPs-Cys/GPE sensor was evaluated by determining epinephrine (EP) in the presence of ascorbic acid (AA), dopamine (DA), uric acid (UA) in phosphate buffer solution by various techniques, including cyclic voltammetry (CV), differential pulse voltammetry (DPV) and chronoamperometry . Further, the proposed sensor not only achieved the selective determination of EP, but also separated the voltammetric signals of AA, DA, EP and UA with potential differences of 266, 250 and 183 mV, respectively. The amperometric current response was increased linearly with increasing EP concentration in the range of 0.2 to 1000 μM with a detection limit of 0.0157 μM (S/N = 3). In addition, the as-obtained sensor delivered extraordinary stability, reproducibility, as well as high resistance to interferences, and was successfully utilized in determining real samples.
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ANALYTICA CHIMICA ACTA
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2018
·
IF 5.123
Maoqiang Chi,Yun Zhu,Liwei Jing,Ce Wang,Xiaofeng Lu
Over the past few years, nanomaterials-based enzymatic mimics have attracted tremendous attention due to their excellent catalytic activity and environmental stability. In this work, ternary MoS 2 -polypyrrole (PPy)-Pd nanotubes have been prepared through a hydrothermal reaction and in situ redox polymerization process between pyrrole monomer and Na 2 PdCl 4 . The prepared MoS 2 -PPy-Pd nanotubes exhibited a higher peroxidase-like catalytic activity than individual MoS 2 , MoS 2 -PPy, PPy-Pd and MoS 2 -Pd nanocomposites due to the synergistic catalytic effect between the three components. The catalytic kinetic of MoS 2 -PPy-Pd nanotubes follows Michaelis-Menten behaviors, exhibiting a good affinity to both 3,3′,5,5′-tetramethylbenzidine (TMB) and H 2 O 2 substrates. On the basis of high peroxidase-like catalytic efficiency of the MoS 2 -PPy-Pd nanotubes, a simple and convenient colorimetric strategy for the rapid and sensitive detection of l -cysteine with a detection limit of 0.08 μM has been developed. In addition, a high selectivity towards the detection of l -cysteine is achieved. This work present an opportunity of the prepared ternary MoS 2 -PPy-Pd nanotubes for promising potential applications in biosensing, environmental monitoring, and medical diagnostics.
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Journal of Functional Foods
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2018
·
IF 3.47
Rui-dan Wang,Guan-hua Su,Lin Wang,Qing Xia,Rui Liu,Qun Lu,Jiu-liang Zhang
This study was aimed at evaluating the hypouricemic effect of rape bee pollen from Qinghai province in China. Rape bee pollen crude extracts (RPCE) was obtained by n-butanol extraction and purified by polyamide resin and AB-8 resin respectively to generate five fractions (fraction 1–5). In vitro , fraction 5 had strongest inhibition on xanthine oxidase (XO) (IC 50 = 0.21 ± 0.02 mg mL −1 ) among five fractions and had reversible and mixed inhibitory effect on XO. Fraction 5 was further purified and then generated fraction 5′. In vivo , fraction 5′ had lower serum UA level and could reduce serum BUN, Cr levels and hepatic XO activity more effectively than RPCE in potassium oxonate-induced hyperuricemic mice . Moreover, fraction 5′ had higher CAT activity and content of GSH in hyperuricemic mice. Six compounds including quercetin-3-O-(2″-O-glucopyranosyl)-glucopyranoside (peak 1), quercetin-3-O-(2″-O-glucopyranosyl)-rhamnopyranoside (peak 2), kaempferol-3-O-(2″-O-glucopyranosyl)-glucopyranoside (peak 3) and N′, N″-di- p -coumaroylspermidine (peak 4–6) in RPCE were identified by using HPLC-ESI-QTOF-MS/MS, whereas only peak 4 to 6 were found in fraction 5′. This study shows that rape bee pollen has potential clinical application value as an effective anti-hyperuricemia bioactive drug or functional food.
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FOOD CHEMISTRY
·
2018
·
IF 4.946
Ying Zhou,Qiyuan Peng,Lanting Zeng,Jinchi Tang,Jianlong Li,Fang Dong,Ziyin Yang
After tea leaves, tea ( Camellia sinensis ) flowers are becoming a second tea plant resource because they contain not only functional metabolites similar to those found in tea leaves, but also predominant amounts of functional metabolites that only occur in tea leaves in small amounts. 1-Phenylethanol (1PE) is a predominant aroma compound found in tea flowers. A 1PE synthase in tea flowers was isolated, functionally characterized, and shown to have the highest catalytic efficiency for the conversion of acetophenone (AP). To determine why 1PE accumulates more in tea flowers than other plants, we compared their 1PE contents and used a stable isotope labeling method to elucidate the 1PE biosynthetic route. Supplementation with [ 2 H 8 ] l -phenylalanine and [ 2 H 5 ]AP suggested that most plants containing the enzyme/gene catalyzed the conversion of AP to 1PE. Furthermore, the availability of AP derived from l -phenylalanine was responsible for the difference in 1PE accumulation between tea flowers and other plants.
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Analytical Methods
·
2018
·Vol. 10
·期 32
·3945-3950
·
IF 2.073
Bingyan Han,Ying Li,Xixi Hu,Qin Yan,Jingmei Jiang,Mingbo Yu,Tingting Peng,Gaohong He
Fluorescence has been extensively employed for visual detection; however, it is inconvenient for people to distinguish single-color fluorescence changes. Herein, a dual-signal ratiometric fluorescent probe of a carbon quantum dot/gold nanocluster (CQD/Au NC) nanosystem for sensitive and selective detection of Ag+ and L-cysteine (Cys) was established. The CQDs with blue fluorescence at 472 nm served as a reference signal and Au NCs with orange fluorescence at 605 nm functioned as a reporter. From zeta potential measurements and TEM images, there was no indication of interaction between the two materials due to electrostatic repulsion. Upon adjusting the proportion of the CQDs and Au NCs, the nanosystem emitted a gray-orange emission at a single excitation wavelength. Ag+ enhanced the orange colour of Au NCs, but Cys could quench it completely with the high affinity of the coordination interaction between Cys and Ag+, while the blue fluorescence of CQDs was not affected. Therefore, the fluorescence of the nanosystem showed gray orange to light orange colour for determination of Ag+, and light orange to blue colour for determination of Cys. Moreover, paper-based visual detection was successfully carried out, which showed a more distinguishable color difference than that in aqueous solution. Our method has bright potential for application in the real-time and online visual detection of Ag+ and Cys in the future.
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BIOSENSORS & BIOELECTRONICS
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2018
·
IF 8.173
Zihua Wang,Yuan Chen,Wenhao Dong,Jiexin Zhou,Bingkai Han,Jun Jiao,Lintao Lan,Peng Miao,Qiang Chen
In this work, carboxylated multi walled carbon nanotubes (CMWCNTs) were firstly prepared and functionalized with poly- L -histidine (PLH), which were then chelated with copper (II) ions to from the nanocomposites of Cu(II)-PLH-CMWCNTs. The nanocomposites could be exploited as an efficient mimic enzyme for sensitive electrochemical detection of salvianic acid A (SAA). Cu(II)-PLH-CMWCNTs owned good charge transfer property and excellent synergetic catalytic effect between the overoxidized imidazole groups and the copper redox-active units. Therefore, highly sensitive electrochemical response to SAA was achieved under optimum experimental conditions. A good linear relationship between differential pulse voltammetry (DPV) peak current and the SAA concentration was established in the range of 0.4–1000 μM. A low detection limit of 0.037 μM and a sensitivity of 0.27 μA μM −1 cm −2 were achieved. The developed biosensor also had advantages of good repeatability, stability and high selectivity, thus, it was successfully applied to the determination of SAA in real samples with satisfactory results, which may have great potential for further exploitation of electroanalysis applications.
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Polymer Chemistry
·
2017
·Vol. 8
·期 45
·7033-7043
·
IF 5.375
Pan Li,Jiacheng Zhang,Chang-Ming Dong
A photoresponsive poly(o-nitrobenzyloxycarbonyl-L-lysine)-b-PEO (PNBL-b-PEO) polypeptide copolymer was synthesized and its photosensitive cleavage and self-assembly were monitored by means of UV-vis spectroscopy, 1H NMR, DLS, and TEM. Three kinds of dual-sensitive (i.e., photo/pH-thermo) polypeptide normal and reverse micellar hydrogels were then fabricated by the physical cross-linking of the self-assembled micelles. Utilizing the inclusion complexation between α-cyclodextrin (α-CD) and PEO of the normal micelles of PNBL-b-PEO or polylysine-b-PEO, photo/pH-thermo-sensitive normal micellar hydrogels were fabricated; in contrast, the reverse micelles of polylysine-b-PEO@α-CD self-assembled at pH = 3 and then were transformed into a pH-thermo-sensitive reverse micellar hydrogel at pH = 10. The multiple self-assembly and hydrogel properties were thoroughly characterized by means of UV-vis spectroscopy, circular dichroism (CD), wide angle X-ray diffraction (WAXD), DLS, zeta potential, rheology, TEM, and SEM. Notably, these dual-sensitive polypeptide hydrogels with a higher mechanical modulus (10–105 kPa) were facilely constructed and the mechanical modulus can be further tuned by varying the UV-irradiation time, the amount of α-CD added, and the copolymer concentration. Consequently, this work provides a versatile platform for constructing polypeptide copolymer hydrogels with tunable mechanical and stimuli-sensitive properties.
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