Nanoscale Research Letters
·
2019
·Vol. 14
·期 1
·1-12
·
IF 3.159
Wang Xianshu,Pan Hongyan,Lin Qian,Wu Hong,Jia Shuangzhu,Shi Yongyong
In situ nitrogen-doped hydrophilic mesoporous carbon spheres with different carbon-to-silicon (C/Si) ratios (NMCs- x /3, x = 5, 6, 7, and 8) were prepared by one-step method coupled with a spray drying and carbonizing technique, in which triblock copolymer (F127) and tetraethyl orthosilicate (TEOS) were used as template agents, and biocompatible chitosan (CS) was used as the carbon source and nitrogen source. These carbon materials were characterized by TG, BET, XRD, Raman, FTIR, TEM, XPS, and contact angle measuring device. The adsorption and release properties of mesoporous carbon materials for the poorly soluble antitumor drug hydroxycamptothecin (HCPT) were investigated. Results showed that nanospherical mesoporous carbon materials were successfully prepared with high specific surface area (2061.6 m 2 /g), narrowly pore size distribution (2.01–3.65 nm), and high nitrogen content (4.75–6.04%). Those NMCs- x showed a satisfactory hydrophilicity, which gradually increased with the increasing of surface N content. And the better hydrophilicity of NMCs- x was, the larger adsorption capacity for HCPT. The absorption capacity of NMCs- x towards HCPT was in the following orders: q NMCs-5/3 > q NMCs-6/3 > q NMCs-7/3 > q NMCs-8/3 . NMCs-5/3 had the largest saturated adsorption capacity of HCPT (1013.51 mg g −1 ) and higher dissolution rate (93.75%).
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 6
·1-8
·
IF 5.479
Liu Xinyan,Deng Keqin,Wang Hao,Li Chunxiang,Zhang Shaowei,Huang Haowen
Gold nanoparticles (AuNPs) with a size of ~3 nm were placed on a thionine-multiwalled carbon nanotube (Thi-CNTs) conjugate to form a novel AuNP-Thi-CNTs nanocomposite. Its morphology and composition were characterized by transmission electron microscopy, atomic force microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The nanocomposite was placed on an electrode and used as a redox-active signaling interface to fabricate a ratiometric electrochemical aptasensor for 17β-estradiol (E2). The potentiostatic insertion method was applied to insert an aptamer against E2 into a thin alkane monolayer to warrant an adequate distance between aptamers. The aptamer against E2 acts as both a collector and separator to specifically bind E2. The electrode displays two peak signals (at +0.50 V vs. SCE for E2; and at −0.32 V for Thi) which increase and decrease, respectively, in the 12 pM to 60 nM E2 concentration range. Therefore, the current ratio can be used to reliably, reproducibly, and sensitively quantify the concentration of E2.
Schematic presentation of a novel AuNP-Thi-CNTs nanocomposite. AuNP-Thi-CNTs showed good electrocatalytic oxidation to E2. AuNP-Thi-CNTs was used as self-redox signal interface to fabricate aptasensor. Dual signals of extrinsic E2 and inner Thi was applied to monitor the concentration of E2.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2019
·Vol. 54
·期 15
·10684-10694
·
IF 3.442
Shen Juanli,Zhou Yiming,Li Shengshi,Gu Pengkun,Xue Guoxin
Fe 3 O 4 magnetic nanoparticles with carboxymethyl cellulose-g-poly(acrylic acid-co-acrylic amide) hydrogel coating (Fe 3 O 4 @hydrogel) were prepared by a coprecipitation method followed by an in situ graft copolymerization. Results of various characterization techniques indicated that hydrogel materials were successfully coated on the Fe 3 O 4 surface with a weight percent of 17.5% and the Fe 3 O 4 @hydrogel has an average size of 10 nm and could be easily collected with the aid of an external magnet. Fe 3 O 4 @hydrogel was used as heterogeneous catalyst to degrade phenol in a Fenton-like reaction. Factors such as initial solution pH, H 2 O 2 concentration and catalyst dosage on the degradation efficiency of phenol were evaluated. Experimental results revealed that about 98.2% phenol and 80.4% chemical oxygen demand (COD) could be removed in 180 min under optimal conditions. Besides, Fe 3 O 4 @hydrogel presented effective phenol degradation at relatively wide pH values ranging from 3.0 to 5.0, and about 50% COD could be eliminated at pH 5.0. The improved catalytic performance of the synthesized catalyst might be ascribed to the pH-sensitive swelling, excellent dispersion, hydrophilicity and permeability of the polymer hydrogel coating. Besides, Fe 3 O 4 @hydrogel showed favorable catalytic stability and reusability with more than 55% of COD removal efficiency after three cycles.
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2018
·Vol. 411
·期 2
·507-515
·
IF 3.307
Yang Yi,Yin Shuo,Yang Danni,Jiang Yang,Li Yongxin,Zhou Chen,Sun Chengjun
A novel carboxyl Fe 3 O 4 magnetic nanoparticle-based solid-phase extraction combined with high-performance liquid chromatography was developed for the analysis of oxytetracycline, tetracycline, demeclocycline, metacycline, chlortetracycline, and doxycycline in water samples. Driven by the electrostatic interaction and the strong chelation between tetracyclines and iron ions, tetracyclines in samples were adsorbed onto the adsorbents. The adsorbed analytes were subsequently eluted with oxalic acid and separated with a C 18 column under gradient condition with a mobile phase consisting of methanol, acetonitrile, and oxalic acid at a flow rate of 0.5 mL/min. The detection was performed at variable ultraviolet wavelengths. Under optimized conditions, the developed method gave an enrichment factor of 33.3, linearity ranges of 5.00–1000 μg/L, detection limits of (2.86–5.19) × 10 -2 μg/L, quantification limits of (9.54–17.3) × 10 -2 μg/L, recoveries of 76.2–98.0%, and intra- and inter-day RSDs of 0.132–15.5% and 2.28–14.5% for these tetracyclines. The established method was successfully applied for the determination of these six tetracyclines in tap water, river water, pond water, and lake water samples.
ᅟ
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CELLULOSE
·
2018
·Vol. 25
·期 12
·7211-7224
·
IF 3.809
Fu Feiya,Zhang Weilan,Zhang Ruihong,Liu Lin,Chen Shichang,Zhang Yupeng,Yang Binbin,Touhid Salvia,Liu Xiangdong,Zhou Jinping,Yao Juming
Abstract Cellulose hybrid fibers embedded with silver nanoparticles (Ag NPs) were prepared from a spinning dope through a bottom-up approach. Instead of using toxic agents or high temperature, an alkaline cellulose dope was directly used as a reducing agent for in situ synthesis of Ag NPs. The regenerated cellulose fibers displayed a dense circular microstructure and Ag NPs with a mean diameter of 40.1 nm were inlaid on its surface and inside. By increasing the spinning drawing ratio, the diameter and Ag content of the nanohybrid fibers decreased while its tensile strength in dry state increased significantly. Because of the embedded structure of NPs, the width of inhibition zone for the nanohybrid fibers against S. aureus and E. coli was small. However, both bacteria could be killed within 5 h in the presence of the nanobybrid fibers. In particular, the nanobybrid fibers showed excellent antibacterial durability and low cell toxicity. Besides, it was demonstrated that the nanobybrid fibers with lower diameter showed better catalytic activity and the catalytic efficiency could reach 99.3% for methyl orange. This biosynthesis approach is expected to offer a sustainable method for scale-up fabrication of functional cellulose fibers. Graphical abstract
✓ 已验证
产品关联
DOI
高影响因子
MICROCHIMICA ACTA
·
2018
·Vol. 185
·期 11
·1-9
·
IF 5.705
Li Zehui,Jiang Yuheng,Wang Zhuoya,Wang Wenbo,Yuan Yi,Wu Xiaoxue,Liu Xingchen,Li Mingjie,Dilpazir Sobia,Zhang Guangjin,Wang Dongbin,Liu Chenming,Jiang Jingkun
Core-shell structured particles were prepared from carbonized zeolitic imidazolate frameworks (ZIFs) and reduced graphene oxide (rGO). The particles possess a nitrogen content of up to 10.6%. The loss of nitrogen from the ZIF is avoided by utilizing the reduction and agglomeration of graphene oxide with suitable size (>2 μm) during pyrolysis. The resulting carbonized ZIF@rGO particles were deposited on a glassy carbon electrode to give an amperometric sensor for H 2 O 2 , typically operated at a voltage of −0.4 V (vs. Ag/AgCl). The sensor has a wide detection range (from 5 × 10 −6 to 2 × 10 −2 M), a 3.3 μM (S/ N = 3) detection limit and a 0.272 μA·μM −1 ·cm −2 sensitivity, much higher than that of directly carbonized ZIFs. The sensor material was also deposited on a screen-printed electrode to explore the possibility of application.
Nitrogen doped carbon (NC) derived from carbonized zeolitic imidazolate frameworks is limited because of low nitrogen content. Here, nitrogen-rich NC@reduced graphene oxide (rGO) core-shell structured particles are described. The NC@rGO particles show distinctly better H 2 O 2 detection performance than NC.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHIMICA ACTA
·
2018
·Vol. 186
·期 1
·1-8
·
IF 5.705
Cui Jingcheng,Chen Shichao,Ma Xicheng,Shao Hua,Zhan Jinhua
This work describes the integration of solid-phase microextraction (SPME) and surface-enhanced Raman spectroscopy (SERS) by codeposition of a hybrid consisting of reduced graphene oxide and silver on silver-copper alloy fibers. The morphology and structure of the coating were characterized by a variety of microscopic and spectroscopic techniques that confirmed the hybrid structure of the material. A galvanic-displacement-induced process is assumed to be involved during the codeposition of the hybrid coating on the alloy. In this process, Ag(I) is reduced to Ag(0) by Cu(0), and the presence of conjugated domains in GO facilitates the long-range transfer of electrons from Cu to Ag+. Simultaneously, GO accepts electrons and is converted into RGO. The hybrid coating exhibits a high SERS enhancement factor and good spatial uniformity. The needle-like coated alloy fibers are shown to be a viable tool for non-destructive sampling and SERS-based determination of trace levels of the antibiotics sulfadiazine and sulfamethoxazole in a spiked tissue mimic. The SERS peaks at 1149 cm −1 for sulfadiazine and 1144 cm −1 for sulfamethoxazole are selected as the reference peaks in the quantitative analysis. The linear range is from 0.01 to 100 μg·cm −3 . The detection limits are 1.9 ng·cm −3 for sulfadiazine and 4.4 ng·cm −3 for sulfamethoxazole.
Schematic presentation of I: Galvanic-displacement-induced reduction of graphene oxide (brown films) and Ag + (purple dots) on silver-copper alloy; II: Codeposition of reduced-graphene-oxide (grey films)/Ag (blue stars) on alloy fiber; III: Non-destructive SPME of antibiotics from spiked tissue mimic; IV: SERS detection using Raman spectroscope.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2018
·Vol. 25
·期 31
·31091-31100
·
IF 2.8
Lei Yu,Zhu Chengzhu,Lu Jun,Zhu Yongchao,Zhang Qiuyue,Chen Tianhu,Xiong Hongbin
The photochemical oxidation of di- n -butyl phthalate (DBP) by • OH radicals from nitrous acid (HONO) in atmospheric hydrometeors was explored by two techniques, steady-state irradiation, and laser flash photolysis (LFP). The effects of atmospheric liquid parameters on DBP transformation were systematically evaluated, showing that DBP does not react with HONO directly and • OH-initiated reactions are crucial steps for consumption and transformation of DBP. Two reaction channels are operative: • OH addition and hydrogen atom abstraction. The overall rate constant for the reaction of DBP with • OH is 5.7 × 10 9 M −1 s −1 , and its specific rate constant for addition is 3.7 × 10 9 M −1 s −1 determined by using laser flash photolysis technique. Comparing the individual reaction rate constant for aromatic ring addition with the total rate constant, the majority of the • OH radicals (about 65%) attack the aromatic ring. The major transformation products were identified by GC-MS, and the trends of their yields derived from both ring addition and H-abstraction with time are discussed. These results provide important insights into the photochemical transformation of DBP in atmospheric hydrometeors and contribute to atmospheric aerosol chemistry.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHIMICA ACTA
·
2018
·Vol. 185
·期 12
·1-9
·
IF 5.705
Gao Tian,Wang Junmin,Hao Lin,Yang Xiumin,Wang Chun,Wu Qiuhua,Wang Zhi
Magnetic knitting aromatic polymers (Fe 3 O 4 /KAPs) are introduced here as a new kind of sorbents. KAPs are hyper-cross-linked-polymers that were prepared via a Friedl-Crafts reaction from triphenylphosphine and benzene as building blocks. The Fe 3 O 4 /KAP composite was obtained by coprecipitation of KAP with magnetite nanoparticles. The resulting Fe 3 O 4 /KAP is shown to be a viable magnetic sorbent for various organic materials such as the phenylurea herbicides (PUHs), including metoxuron, monuron, chlortoluron, monolinuron and buturon, and also for various phthalates, polycyclic aromatic hydrocarbons and chlorophenols. The Fe 3 O 4 /KAP was characterized by means of Brunauer-Emmett-Teller surface area measurements, Fourier-transform infrared spectroscopy, thermogravimetry, X-ray diffraction, scanning electron microscopy and transmission electron microscopy. Following desorption with acetonitrile, the analytes were quantified by using HPLC with UV detection. The effects of adsorbent dosage, extraction time, sample pH, ionic strength, desorption solvent and desorption time were optimized for the PUHs. Under optimal conditions, response is linear from 0.5–1.0 up to 50 ng·mL −1 for the five PUHs. Lower limits of detection range between 0.05 and 0.30 ng·mL −1 . Other figures of merit include (a) high enrichment factors (60–297), (b) good recoveries (91.8–106.5%), and (c) relative standard deviations of <8.4%. The method was successfully applied to analysis of the PUHs in real samples (bottled mixed juice, milk and soymilk). The results indicate that such Fe 3 O 4 /KAPs have a wide application scope as an adsorbent for use in magnetic solid phase extraction.
A magnetic knitting aromatic polymer based nanocomposite (Fe 3 O 4 /KAP) was prepared by a one-pot method and explored as an absorbent for magnetic solid-phase extraction (MSPE) of phenylurea herbicides (PUHs) from bottled mixed juice, milk and soymilk samples before quantitation by HPLC with UV detection.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
·
2018
·Vol. 102
·期 24
·10713-10727
·
IF 3.34
Wang Yanbo,Xie Qiuhong,Sun Sheng,Huang Baojia,Zhang Ying,Xu Yun,Zhang Shumin,Xiang Hongyu
Weaning stress has serious negative effects on piglets’ health and the swine industry. Probiotics-fermented Chinese herbal medicines are potential feed additives to ameliorate weaning stress. In this study, the effects of probiotics-fermented Massa Medicata Fermentata (MMFP) on intestinal homeostasis were evaluated in weaning piglets. Dietary supplementation with MMFP promoted the development of the intestinal structure and elevated the concentrations of lactic acid and short-chain fatty acids (SCFAs) in the intestinal contents and antioxidant capacities in serum. MMFP reduced the levels of inflammatory factors in the intestinal mucosa. Microbial community analysis demonstrated that MMFP led to the selective and progressive enrichment of lactic acid- and SCFA-producing bacteria along the gastrointestinal tract, in particular, OTUs corresponding to Lactobacillus , Streptococcus , Acetitomaculum , Roseburia , and Eubacterium xylanophilum group, while MMFP reduced the relative abundance of pathogenic bacteria. On the contrary, antibiotics had negative effects on intestinal histology and increased the relative abundance of pro-inflammatory bacterium, such as Marvinbryantia , Peptococcus , Turicibacter , and Blautia . Correlation analysis reflected that the bacteria enriched in MMFP group were positively correlated with enhanced intestinal homeostasis, which suggested that dietary supplementation with MMFP enhanced host intestinal homeostasis by modulating the composition of gut microbiota and the levels of beneficial SCFAs, thus ameliorating weaning stress in piglets.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Scientific Reports
·
2018
·Vol. 8
·期 1
·1-11
·
IF 4.122
Xiao Qiling,Zhou Qiongqiong,Yang Lu,Tian Zhongyuan,Wang Xiliang,Xiao Yuncai,Shi Deshi
Human carboxylesterases has been proven to be age and race-related and a sound basis of clinical medication. PLE involve in signal transduction and highly catalyze hydrolysis. Therefore, the expression level of PLE most probably exist age and breed difference and lead to significant differences of pharmacology and physiology. Four age groups of Tongcheng (TC) and Large White (LW) pigs were selected to explore PLE breed and age differences, and it was found that PLE mRNA was most abundant in liver in both breeds. In liver, PLE levels and hydrolytic activities increased with age, and PLE levels (except for 3 month) and the hydrolytic activities were higher in LW than in TC across all age groups. Abundance of PLE isoenzymes was obvious different between breeds and among age groups. The most abundant PLE isoenzyme in LW and TC pigs was PLE-A1 (all age groups) and PLE-B9 (three early age groups) or PLE-G3 (adult groups), respectively. 103 new PLE isoenzymes were found, and 55 high-frequency PLE isoenzymes were accordingly classified into seven categories (A-G). The results of this research provide a necessary basis not only for clinical medication of pigs but also for pig breeding purposes.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2018
·Vol. 88
·期 3
·639-645
·
IF 1.745
Wang Yunwei,Zhao Gaoyang,Wu Chuanbao,Duan Zongfan
CaMn 7 O 12 precursor sol was prepared by using Ca(NO 3 ) 2 ·4H 2 O and Mn(CH 3 COO) 4 ·4H 2 O as the raw materials, acetylacetone (AcAcH) as the chelating agent, and methyl alcohol (MeOH) as the solvent. The CaMn 7 O 12 crystalline film was obtained via dip-coating and annealing treatment on the LaAlO 3 (001) single-crystal substrate. XRD θ -2 θ scan indicated that the as-prepared CaMn 7 O 12 film had strong preferred orientation along the c -axis. In addition, the results of the ω and ϕ scans demonstrated that the film exhibited outstanding out-of-plane and in-plane texture characteristics. The SEM characterization showed that the CaMn 7 O 12 film was dense and free of cracks. The grain size was uniform with an average size of ~180 nm. Vibrating sample magnetometer (VSM) test results indicated the CaMn 7 O 12 film was antiferromagnetic and had a saturation magnetization of 114.2 emu/cm 3 at 50 K.
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）