MICROCHIMICA ACTA
·
2020
·Vol. 187
·期 4
·1-8
·
IF 6.232
Ren Lei,Li Hongdan,Du Jianxiu
Black phosphorus quantum dots (BP QDs) with small size are synthesized using an easy to operate thermal method. It was found that BP QDs possess oxidase-mimicking activity. They can catalyze the oxidation of the substrate 3,3′,5,5′-tetramethylbenzidine to produce a blue-colored product even in the absence of hydrogen peroxide. Active oxygen species are proved to be involved in the reaction through the experiments of radical scavenging and electron spin resonance. Biothiols including reduced glutathione and cysteine inactivate the oxidase-mimicking activity of BP QDs, concomitant to the fading of the blue solution. This provides the base for a colorimetric method for the determination of glutathione and cysteine. The decreased absorbance at 652 nm displays linear response to the concentrations of glutathione ranging from 0.1 to 5.0 μmol L −1 , and cysteine from 0.1 to 10.0 μmol L −1 . The detection limits are 0.02 μmol L −1 and 0.03 μmol L −1 for glutathione and cysteine, respectively. Successive determinations of 1.0 μmol L −1 glutathione and 5.0 μmol L −1 cysteine solution give relative standard deviations of 0.8% and 1.7% ( n = 11), respectively. As a preliminary application, the practicability of the method was evaluated by the determination of glutathione in pharmaceutical preparations. This work not only discovers a useful oxidase mimics but also sets up a reliable platform based on BP QDs in colorimetric detection.
Schematic representation of colorimetric determination for biothiols through inactivating oxidase mimetic−like catalytic activity of black phosphorus quantum dots (BP QDs) on the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) with dissolved oxygen to produce its blue oxidized product (oxTMB).
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MICROCHIMICA ACTA
·
2020
·Vol. 187
·期 2
·1-9
·
IF 6.232
Xiang Ling,Zhang Feng,Feng Jian,Chen Chunyan,Cai Changqun
A method is described for the simultaneous determination of hepatocellular carcinoma-associated microRNA-122 and microRNA-199a/b-3p. This probe consists of two kinds of nanomaterials. The first comprises CdTe@CdS core-shell quantum dots which, on excitation at 375 nm give two emissions, with peak wavelengths at 543 (g-QDs) and at 627 nm (r-QDs). The second comprises gold nanoparticles acting as a quencher. In the absence of the target, g-QD-N1 and r-QD-N2 are stable due to the fluorescence stability. With the addition of microRNA-122 and microRNA-199a/b-3p, g-QD-N1 and r-QD-N2 are conjugated to the surface of AuNP-S1/S2 through base complementary pairing. As a result, fluorescence resonance energy transfer (FRET) occurs, resulting in a decrease at 550 nm and 635 nm respectively, which can realize the simultaneous detection of two different microRNAs. Detection is achieved within 50 min. The detection limits (3σ/k) are 0.2 nM for microRNA-122 and 0.5 nM for microRNA-199a/b-3p. The clinical applicability of the assay was demonstrated by detecting microRNAs in human serum and different cell lysates.
Schematic for the simultaneous determination of microRNA-122 and microRNA-199a/b-3p by FRET.
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International Journal of Minerals Metallurgy and Materials
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2020
·Vol. 27
·期 1
·37-45
·
IF 1.713
Wang Yu,Zhang Guo-hua,Wu Yue-dong,He Xin-bo
The method of calciothermic reduction of B 4 C was proposed for preparing CaB 6 . The phase transition and morphology evolution during the reaction were investigated in detail. The experimental results reveal that Ca first reacts with B 4 C to generate CaB 2 C 2 and CaB 6 at a low temperature and that the CaB 2 C 2 subsequently reacts with Ca to produce CaB 6 and CaC 2 at a high temperature. After the products were leached to remove the byproduct CaC 2 , pure CaB 6 was obtained. The grain size of the prepared CaB 6 was 2–3 μm, whereas its particle size was 4–13 μm; it inherited the particle size of B4C. The residual C content of the product was decreased to 1.03wt% after the first reaction at 1173 K for 4 h and the second reaction at 1623 K for 4 h.
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Nano Research
·
2020
·Vol. 13
·期 2
·511-526
·
IF 8.183
Zhu Zhou,Jiang Shaokang,Liu Yanhua,Gao Xiaomeng,Hu Shanshan,Zhang Xin,Huang Chao,Wan Qianbing,Wang Jian,Pei Xibo
In recent years, various particulate materials have played important roles in medical applications. However, nano- and micron-sized particles of the same material could exhibit distinct properties due to different particle sizes. This finding provided a simple and effective way to improve the biological applications of particulate materials. Therefore, as a highly promising member, the effect of the particle size change of the magnesium metal organic framework-74 (Mg-MOF74) was well worth evaluating. Here we firstly assessed the in vitro and in vivo toxicity of micron/nanoscale Mg-MOF74 (m-Mg-MOF74/n-Mg-MOF74) in detail. Our in vitro study revealed that compared to micron-sized subjects, n-Mg-MOF74 provided a wider range of safe concentrations. Furthermore, both micron/nanoscale Mg-MOF74 showed good biocompatibility and allowed all the rats under the treatment to survive through the expected experimental periods, with n-Mg-MOF74 still showing lower cardiotoxicity. These advantages of nanoscale Mg-MOF74 might benefit from its sustainable and balanced release of Mg 2+ both inside and outside the cells. Based on the biosafety evaluation, advanced bio-functional assessments of m/n-Mg-MOF74 including early osteogenesis and angiogenesis were also performed. Similarly, the suitable dose groups of n-Mg-MOF74 achieved optimal early osteogenic promotion and angiogenic stimulation effects. Overall, our combined data delineated the toxicity and biological behaviors of Mg-MOF74 of different scales, and suggested nanoscale Mg-MOF74 as a better choice for future applications. This result revealed that particle size reduction might be a viable strategy to improve and expand medical applications of MOFs or other particulate materials.
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Journal of Biological Engineering
·
2020
·Vol. 14
·期 1
·1-13
·
IF 3.429
Liu Qingxiu,Zhang Wei,Chen Siying,Zhuang Zhenjing,Zhang Yi,Jiang Lingli,LIN Jun Sheng
Background Aptamers, single-stranded DNAs or RNAs, can be selected from a library containing random sequences using a method called Systematic Evolution of Ligands by EXponential Enrichment (SELEX). In SELEX, monitoring the enriching statuses of aptamer candidates during the process is a key step until today. Conformational change of an aptamer caused by target-binding in gel can be used to indicate its statuses of binding. Results In this study, an easy-to-implement gel-based diffusion method (GBDM) was developed to monitor the interaction between enriched aptamer candidates and their targets. In order to prove the concept, characterization of aptamers targeting their targets including protein (thrombin) and non-protein molecules (acetamiprid, ATP, atrazine, profenofos and roxithromycin), respectively, were performed using mini gels. Our method has advantages over the common methods including easy performed with labor- and time- saving in experimental operation. The concept has been proven by monitoring enrichment of dynamic aptamer candidate libraries targeting a small molecule 2,2-bis(4-chlorophenyl) acetic acid (DDA) during SELEX process. A mini gel cassette was designed and fabricated by our laboratory to make mini agarose gels for diffusion with different directions. Conclusions These results indicate that GBDM, in particular, chasing diffusion is suitable for monitoring the interaction between enriched aptamer candidates and their targets. These pioneering efforts are helpful for novel aptamer selection by breaking through the technical bottleneck of aptamer development and helpful for development of novel aptasensors.
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CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2020
·Vol. 36
·期 1
·120-126
·
IF 1.063
Chen Jianfei,Chen Xiaoyu,Zhang Xing,Yuan Yao,Bi Ruyi,You Feifei,Wang Zumin,Yu Ranbo
BiVO 4 , a promising visible-light responding photocatalyst, has aroused extensive research interest because of inexpensiveness and excellent chemical stability. However, its main drawback is the poor photoinduced charge-transfer dynamics. Building nanostructures is an effective way to tackle this problem. Herein, we put forward a new method to prepare nanostructured BiVO 4 from Bi-based metal-organic frameworks[Bi-MOF(CAU-17)] precursor. The as-prepared material has a rod-like morphology inherited from the Bi-MOF sacrificial template and consists of small nanoparticle as building blocks. Compared with its counterparts prepared by conventional methods, MOF-derived nanostructured BiVO 4 shows better light absorption ability, narrower bandgap, and improved electrical conductivity as well as reduced recombination. Consequently, BiVO 4 nanostructure demonstrates high photocatalytic activity under visible light towards the degradation of methylene blue. Methylene blue can be degraded up to 90% within 30 min with a reaction rate constant of 0.058 min −1 . Moreover, the cycling stability of the catalyst is excellent to withstand unchanged degradation efficiency for at least 5 cycles.
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METABOLIC BRAIN DISEASE
·
2020
·Vol. 35
·期 2
·373-383
·
IF 2.726
Zhou Yiying,Wu Xiang,Ye Luying,Bai Yujing,Zhang Hui,Xuan Zhenquan,Feng Yi,Zhang Panpan,Chen Yi,Yan Yushan,Zhu Binbin,Cui Wei
Postoperative cognitive dysfunction (POCD) is a common neurological disease affecting the elderly patients after surgery. Unfortunately, no effective treatment for this disease has been discovered. Edaravone, a clinical-used free radical scavenger, at 3 mg/kg has been reported to prevent neuroinflammation induced by the combination of surgery and lipopolysaccharide in adult rodents. However, we found that edaravone at such low concentration could not inhibit POCD in aged mice. Instead, edaravone at 33.2 mg/kg significantly prevented recognition and spatial cognitive dysfunctions in 14 month aged mice after abdominal surgery under general anesthesia with isoflurane. Furthermore, edaravone significantly prevented the increase of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) induced by abdominal surgery in aged mice. Edaravone could also decrease glial fibrillary acidic protein (GFAP) and ionized calcium binding adaptor molecule-1 (Iba-1) positive areas in the hippocampal regions of surgery mice, suggesting that edaravone might inhibit surgery-induced over-activation of microglia and astrocytes. Moreover, edaravone substantially increased the expression of PSD-95 and pSer9-glycogen synthase kinase-3β (pSer9-GSK3β) as demonstrated by Western blotting assay. Furthermore, the activity of acetylcholinesterase (AChE) is decreased in the mice in edaravone group. All these results suggested that edaravone at high concentrations could inhibit surgery-induced cognitive impairments in aged animals, possibly via the attenuation of neuroinflammation, the increase of synaptic proteins, and the elevation of cholinergic transmission, providing a further support that edaravone might be developed as a treatment of POCD.
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Journal of Neuroinflammation
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2020
·Vol. 17
·期 1
·1-13
·
IF 5.793
Bian Hetao,Wang Gaohua,Huang Junjie,Liang Liang,Zheng Yage,Wei Yanyan,Wang Hui,Xiao Ling,Wang Huiling
Background Recently, depression has been identified as a prevalent and severe mental disorder. However, the mechanisms underlying the depression risk remain elusive. The neuroinflammation and NLRP3 inflammasome activation are known to be involved in the pathology of depression. Dihydrolipoic acid (DHLA) has been reported as a strong antioxidant and exhibits anti-inflammatory properties in various diseases, albeit the direct relevance between DHLA and depression is yet unknown. The present study aimed to investigate the preventive effect and potential mechanism of DHLA in the lipopolysaccharide (LPS)-induced sickness behavior in rats. Methods Adult male Sprague–Dawley rats were utilized. LPS and DHLA were injected intraperitoneally every 2 days and daily, respectively. Fluoxetine (Flu) was injected intraperitoneally daily. PD98059, an inhibitor of ERK, was injected intraperitoneally 1 h before DHLA injection daily. Small interfering ribonucleic acid (siRNA) for nuclear factor erythroid 2-like (Nrf2) was injected into the bilateral hippocampus 14 days before the DHLA injection. Depression-like behavior tests were performed. Western blot and immunofluorescence staining detected the ERK/Nrf2/HO-1/ROS/NLRP3 pathway-related proteins. Results The DHLA and fluoxetine treatment exerted preventive effects in LPS-induced sickness behavior rats. The DHLA treatment increased the expression of ERK, Nrf2, and HO-1 but decreased the ROS generation levels and reduced the expression of NLRP3, caspase-1, and IL-1β in LPS-induced sickness behavior rats. PD98059 abolished the effects of DHLA on preventive effect as well as the levels of Nrf2 and HO-1 proteins. Similarly, Nrf2 siRNA reversed the preventive effect of DHLA administration via the decreased expression of HO-1. Conclusions These findings suggested that DHLA exerted a preventive effect via ERK/Nrf2/HO-1/ROS/NLRP3 pathway in LPS-induced sickness behavior rats. Thus, DHLA may serve as a potential therapeutic strategy for depression.
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CHINESE JOURNAL OF POLYMER SCIENCE
·
2020
·Vol. 38
·期 11
·1171-1177
·
IF 3.154
Lang Mu-Ning,Chi Wei-Wen,Han Ting,Zhao Qing-Zhen,Li Hong-Kun,Tang Ben Zhong,Li Yong-Fang
Azide-alkyne click polymerization has become a powerful tool for polymer synthesis. However, the click polymerization between internal alkynes and azides is rarely utilized to prepare functional polymers. In this work, the polymerization reactions of activated internal alkyne monomers of tris(2-butynoate)s ( 1 ) with tetraphenylethene-containing diazides ( 2 ) were performed in dimethylformamide (DMF) under simple heating, affording four hyperbranched poly(methyltriazolylcarboxylate)s ( hb -PMTCs) with high molecular weights ( M w up to 2.4 × 10 4 ) and regioregularities (up to 83.9%) in good yields. The hb -PMTCs are soluble in common organic solvents, and thermally stable with 5% weight loss temperatures up to 400 °C. They are non-emissive in dilute solution, but become highly emissive in aggregated state, exhibiting aggregation-induced emission characteristics. The polymers can generate fluorescent photopatterns with high resolution, and can work as fluorescent sensors to detect nitroaromatic explosive with high sensitivity.
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JOURNAL OF POLYMER RESEARCH
·
2020
·Vol. 27
·期 6
·1-5
·
IF 2.426
Wang Zhanwen,Li Shizhuo,Wang Jianhua,Han Enlin,Tian Guofeng,Wu Dezhen
Polyimide (PI)/ bisphenol A dicyanate esters (BADCy) composite laminates with varying resin contents were prepared by filament winding and autoclave molding process. The laminates exhibited ultralow dielectric constant ( ε of 3.15–3.25) and dielectric loss (tan δ of 0.004–0.006) as well as excellent mechanical properties. When the resin content was 35.6%, the composite achieved outstanding comprehensive properties with tensile strength and modulus equal to 1485.1 MPa and 80.9 GPa, respectively, and the inter-laminar shear strength (ILSS) up to 66.2 MPa. The failure mode of laminates followed an explosive gage middle (XGM) mechanism, which suggested a favorable interface between fiber and resin. According to the mixed law equation, PI fiber at a frequency of 10.2 GHz exhibited dielectric constant of 3.41 ± 0.03 and dielectric loss of about 0.002–0.004. The successful preparation of PI fiber reinforced BADCy composite with low dielectric constant provides new ideas for material design and selection of lightweight high-strength structural-functional integrated composites.
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MICROCHIMICA ACTA
·
2020
·Vol. 187
·期 6
·1-10
·
IF 6.232
Li Kun,Zhao Bao,Yu Qingcai,Xu Juan,Li Xuewei,Wei Diandian,Qian Lisheng,Liu Guodong,Wang Wenrui
A porous hydrophilic affinity bead consisting of graphene oxide and chitosan (pGC) with the honeycomb-biomimetic microchannels has been synthesized and applied as hydrophilic adsorbent for selective capture of glycopeptides. The pGC beads have open-porous structure, honeycomb-like microchannels, large interior voids, and hydrophilic property. Based on the multivalent hydrophilic interactions between glycan moieties on glycopeptides and amino groups and hydroxyl groups on chitosan, the glycopeptides were enriched and separated by pGC beads. The pGC beads exhibit high sensitivity (detection limit, 5 fmol), binding capacity (111.1 mg/g), enrichment selectivity (molar ratio of human IgG to BSA tryptic digests of 1:200), and recovery yield (89.78%). By combing pGC beads and nano LC-MS/MS analysis, a total of 325 N-glycosylated peptides corresponding to 152 N-glycosylated proteins were identified from 2 μL human serum. These experimental results demonstrate the practical application of the method in glycoproteomics research.
Schematic representation of fabrication for porous hydrophilic affinity beads (pGC) with honeycomb-biomimetic microchannels based on graphene oxide (GO) and chitosan (CS). The pGC was successfully applied to capturing and identifying low-abundant glycopeptides from biological samples.
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CELLULOSE
·
2020
·Vol. 27
·期 10
·5955-5970
·
IF 4.21
Sun Lijian,Yang Shuaishuai,Qian Xueren,An Xianhui
Abstract In the current study, we introduce “click chemistry” as a powerful tool to tailor cyclodextrin–cellulose combination product followed by the inclusion of ciprofloxacin hydrochloride (CipHCl) as antibacterial agent. Initially, beta-cyclodextrin (β-CD) and cellulose fibers (CFs) were modified so as to be mono-6-propargylamino-6-deoxy-β-CD (Pro-β-CD) and azidated cellulose fibers (CFs-N 3 ), respectively. Afterward, the “click reaction” was carried out between Pro-β-CD and CFs-N 3 to fabricate a covalent grafting of β-CD onto CFs resulting in click product (CFs-N 3 @Pro-β-CD). The drug-delivery kinetics of the loaded CipHCl was performed by immersing samples into an aqueous solution, and the amount of adsorbed and released CipHCl was measured, as a function of time, by UV spectroscopy. Compared to original CFs, the load quantity of CipHCl into the click product was greatly increased, the release time of CipHCl from CFs-N 3 @Pro-β-CD was prolonged, and considerably higher antibacterial activity against E. coli and S. aureus was observed. The click product exhibited excellent antibacterial activity and sustained antibacterial efficacy up to 12 and 10 days against S. aureus and E. coli . The results showed that β-CD has been successfully grafted onto CFs via covalent bonds, while maintaining the intrinsic properties and the integrity of the fibers. Compared with the control paper sheet, the mechanical properties of the paper are well preserved. Graphic abstract
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危险品化学品经营许可证（带存储）