查找使用阿拉丁产品的科研文献

Molecular cloning, the characterization of metallothionein and catalase, and the evaluation of testicular toxicity of Cd in the Chinese fire-bellied newt (Cynops orientalis)

Shi-Long Ruan,Lei Xie,Jun-Wei Ou,Xue-Song Sun,Yong-Pu Zhang,Jian-Rao Hu

Cadmium (Cd) is an environmental toxicant and a nonessential metal. Cd can attack a wide range of organs, such as the liver, kidney, lung, ovary, testis, brain, and muscle in vertebrates. Among these organs, the testis might be the most sensitive organ to Cd toxicity. Metallothionein (MT) is a cysteine-rich protein with a low molecular weight, that can bind with Cd and eliminate reactive oxygen species (ROSs). Hydrogen peroxide, which as a crucial type of ROS that is induced by Cd, can be eliminated by catalase (CAT) in the self-protection of cells and to realize Cd toxicity resistance. To investigate the functions of MT and CAT in the testis of Cynops orientalis , we cloned the full-length MT and CAT genes of C. orientalis for the first time. Immunofluorescence results demonstrated that MT and CAT were expressed in Sertoli cells and all spermatogenic cells in the testis of C. orientalis . The results of the ultrastructural damage assay demonstrated that there were various impairments, which included organelle vacuolization, abnormal chromatin distribution, and apoptotic bodies, in somatic cells that were exposed to Cd. However, the anomalies of spermatozoa were located mainly in the mid-piece and head, many of which showed severely impaired structures. The results demonstrated that MT and CAT expression had distinct patterns in response to various Cd concentrations: an increase in MT mRNA levels with elevated Cd levels and a persistent increase in CAT mRNA levels with elevated Cd levels. These results suggested that MT and CAT play roles in Cd toxicity resistance in the testis and that the expression of CAT may be a better biomarker than the expression of MT for assessing Cd pollution.

Enhancing the removal performance of Cd(Ⅱ) from aqueous solutions by NaA zeolite through doped thiourea reduced GO which is trapped within zeolite crystals

Juan Liu,Zhujian Huang,Jie Sun,Yixuan Zou,Beini Gong

In this study, thiourea reduced graphene oxide/NaA zeolite composite (tGO-Zeo) was successfully prepared by a facile two-step synthetic route and used as an efficient adsorbent for removal of Cd(II) from aqueous solution. Characterization of the composite material showed that tGO was entrapped within zeolite crystalline particles and intimately interacted with the zeolite framework. Furthermore, the presence of tGO considerably reduced zeolite crystal size and altered crystal morphology, turning cubic zeolite crystals of micrometer size into nanometer irregular particles. Batch adsorption experiment for Cd(II) removal was conducted and the adsorption performance of tGO-Zeo and Zeo (zeolite) were determined. It was shown that doped tGO significantly enhanced the adsorption capacity of zeolite by 31.54%. The adsorption mechanism differs for tGO-Zeo and Zeo, and tGO-Zeo has higher affinity for Cd(II). The adsorption capacity of tGO-Zeo with a tGO doping amount of 1.26% (wt%) was estimated to be 196 mg/g (1.74 mM/g) at 30 °C and superior to most previously reported zeolite based composites, which often contain large amounts of dopants . The effects of pH and ionic strength on adsorption suggest that ion exchange and coordination are responsible for Cd(II) adsorption by tGO-Zeo. Humic acid can slightly increase Cd(II) adsorption performance of tGO-Zeo, which may be due to tGO-Zeo—humic acid—Cd(II) complexes formation. Therefore, tGO-Zeo composite is a cost-effective and eco-friendly adsorbent for efficient removal of Cd(II) ions from aqueous solutions.

A novel ex-situ charge interaction strategy for the fabrication of graphene oxide/organic functionalized silica nanoparticles composites and application in Cd (II) adsorption

Wang Pengpeng,Li Jie,Chen Lianxi,Fang Jinjin

Abstract In this study, a new-style “ex-situ charge interaction” strategy has been developed to prepare graphene oxide/organic functionalized silica nanoparticles (GO/OSNs) composites. The crucial point of the strategy is that the OSNs have positive charge by adding Hydrochloric acid (HCl). Four types of OSNs were prepared via one-pot sol–gel reaction of four different kinds of organosilane. Then the positively charge OSNs and negatively charge GO could effectively composite via charge interaction. The GO/OSNs were characterized by Scanning electron microscope (SEM), Transmission electronic microscope (TEM), Fourier transform infrared (FT-IR), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The results showed that “ex-situ charge interaction” strategy might be a general method for the fabrication of GO/OSNs. This research provides a new approach for the fabrication of GO/OSNs composites with other OSNs structures. In addition, the application of GO/OSNs in the adsorption of Cd(II) has also been investigated, which included adsorption properties of four GO/OSNs, parameters of adsorption isotherm and adsorption kinetics. GO/OSNs composites were fabricated based on a new-style “ex-situ charge interaction” strategy. OSNs were first prepared via one-pot sol–gel reaction. Furthermore, they were given positive charge by adding HCl. Finally, GO/OSNs were fabricated by charge interaction of between GO and OSNs.

A novel polyamine-type starch/glycidyl methacrylate copolymer for adsorption of Pb(II), Cu(II), Cd(II) and Cr(III) ions from aqueous solutions

Youning Chen,Wei Zhao,Huan Wang,Xiaohua Meng,Linjie Zhang

A novel polyamine-type starch/glycidyl methacrylate (GMA) copolymer with a high capacity for the adsorption of heavy metal ions was prepared via graft copolymerization of GMA and corn starch and a subsequent amination reaction between amino group of diethylenetriamine and epoxy group in GMA. The copolymers were characterized by Fourier transform infrared spectrometry, X-ray diffraction and scanning electron microscopy, and adsorption properties on modified starch of Cu(II), Pb(II), Cd(II) and Cr(III) were studied. By analysing the relationship between adsorption capacity and pH, adsorption isotherms and adsorption kinetics, it is proved that the adsorption of the four metal ions is mainly based on the chemical adsorption of coordination. The maximum adsorption capacities of the copolymer were up to 2.33, 1.25, 0.83 and 0.56 mmol g−1 for Cu(II), Pb(II), Cd(II) and Cr(III), respectively. The adsorption of the four concerned metal ions was hardly affected by common coexisting ions such as Na(I), K(I), Ca(II) and Mg(II), whereas it was slightly decreased when Fe(II) and Zn(II) coexisted in the solution, which illustrates the selective adsorption of Cu(II), Pb(II), Cd(II) and Cr(III) from wastewater. After 10 cycles of adsorption–desorption experiments, there was no significant change in the adsorption capacity, indicating that the polyamine-type starch/GMA copolymer has high adsorption capacity and good reusability.

Simultaneous detection of Cd(II) and Pb(II) by differential pulse anodic stripping voltammetry at a nitrogen-doped microporous carbon/Nafion/bismuth-film electrode

Lili Xiao,Hongbo Xu,Shenghai Zhou,Ting Song,Huanhuan Wang,Shouzhu Li,Wei Gan,Qunhui Yuan

Recently, metal-organic frameworks (MOFs) and their carbon derivates have been demonstrated as new electrode modifying materials for electrochemical sensing. In this work, the first example of the detection of heavy metal ions with a MOF-derived sensing platform was presented. The platform was based on a glassy carbon electrode (GCE) modified by Nafion-bismuth/nitrogen doped microporous carbon (NMC) composite, in which the NMC was derived from a zeolitic imidazolate framework-8 (ZIF-8). The good dispersibility, large specific surface area (941 m 2   g −1 ), high nitrogen content (25.0 at.%) and good electrical conductivity of the NMC materials, as well as the synergistic effects of Nafion and bismuth-film contributed to the enhanced signals of the electrode during the differential pulse anodic stripping voltammetry (DPASV) measurements for simultaneous detection of trace Cd(II) and Pb(II) in aqueous solution. The calibration curves for Cd(II) covered two linear ranges varying from 2 to 10   μg   L −1 and 10 to 100   μg   L −1 . As for Pb(II), the linear calibration curves ranged from 0.5 to 10   μg   L −1 and 10 to 100   μg   L −1 . The detection limits were estimated to be 1.5   μg   L −1 (S/N   =   3) for Cd(II) and 0.05   μg   L −1 (S/N   =   3) for Pb(II), which were 2 times and 200 times lower than the guideline values of drinking water given by the World Health Organization (WHO), for Cd(II) and Pb(II), respectively. In addition, the good reproducibility and stability of the modified electrode offered a promising perspective for the detection of trace metal ions in practice. Compared with other porous carbon modified electrodes that obtained by either drop-casting or screen-printing method, the proposed Nafion/Bi/NMC/GCE showed a much lower detection limit for Pb(II) and a lower or comparable detection limit for Cd(II). Moreover, the obtaining of uniformly ordered N-doped carbon polyhedron could shed light on the preparation of other heteroatom-doped electrode modifying materials for the detection of heavy metal ions .

Synthesis of a tetrazine-based catecholamide derivative and its evaluation as a chelating agent for removal of Cd(II), Co(II), and Cu(II)

Shan Lei,Bo Jin,Rufang Peng,Qingchun Zhang,Shijin Chu

Imidazole functionalized organic monoliths for capillary microextraction of Co(II), Ni(II) and Cd(II) from urine prior to on-line ICP-MS detection

Liu Xiaolan,Suo Feiya,He Man,Chen Beibei,Hu Bin

Monoliths composed of poly(1-vinylimidazole-ethylene glycol dimethacrylate), referred to as poly(VI-EGDMA), were modified with imidazole groups and used in capillary microextraction (CME) of trace levels of Co(II), Ni(II) and Cd(II) ions from human urine samples. The effects of sample pH, sample flow rate, sample volume, elution conditions and potentially interfering ions were investigated. Under the optimized conditions, the limits of detection (3σ) are 0.6 ng L −1 for Co(II), 6.4 ng L −1 for Ni(II) and 0.7 ng L −1 for Cd(II), with the relative standard deviations of 1.8 (Co), 4.2 (Ni) and 2.2% (Cd). A Certified Reference Material (ZK018–2, lyophilized human urine) was analyzed to validate the method, and the values found were in good agreement with the certified ones. The method was successfully applied to the analysis of trace Co, Ni and Cd in human urine samples, and the recoveries for spiked samples were in the range from 89% to 105%. The one-step preparation of monolithic material in our perception is an attractive feature for this material which also excels by good extraction performance in that it possesses abundant adsorption sites, good stability and a long lifetime. Two poly(1-vinylimidazole-ethylene glycol dimethacrylate) monolithic capillaries were combined with ICP-MS to improve the analytical speed and used for the analysis of Co(II), Ni(II) and Cd(II) in human urine samples.

Enhancement of Oryzanol application by constructing modified β-CD inclusion complex and polycaprolactone-chitosan electrospun fiber membranes: Perspectives on wound dressings and grape preservation

Wen Li,Jintao He,Qijue Chen,Feng Bao,Yinqiang Huo,Jing Deng,Qinlu Lin,Feijun Luo

Oryzanol has a variety of physiological activities and is widely used in food and medicine. However, its utilization form and bioavailability are limited by poor solubility and photothermal stability. In this paper, an inclusion complex (IC) was prepared by modifying β-cyclodextrin as a molecular carrier to encapsulate Oryzanol. Polycaprolactone-chitosan (PCL-CS) and IC were prepared into a fiber membrane (PCL-CS-IC) using an electrostatic spinning technique and applied to wound healing and grape preservation. The results showed that the prepared ICs had a drug loading rate of 43.18 % with good antimicrobial, wettability, and air permeability properties. The PCL-CS-IC effectively reduced the inflammation of mouse wounds, with obvious re-epithelialization and inflammatory factors reduction in skin tissues. Meanwhile, the PCL-CS-IC delayed the decay process of grapes and extended shelf life. In conclusion, this study effectively improved the utilization of oryzanol and provided potential ideas for wound dressing preparation and food packaging materials development.

De novo synthesis of α-Alk-β-CD: An organic–inorganic hybrid chiral stationary phase for enhanced enantioseparation efficiency and its recognition mechanism research

Jianbin Zhang,Qiufang Bai,Mei Han,Xizhe Sun,Feixue Zhou,Xin Fang,Yuran Shi,Hongna Wang,Yaowen Zhang,Linwei Li,Linlin Fang

Herein, two highly stable β -CD and α-Alkenyl- β -CD ( α -Alk- β -CD) monolithic columns were fabricated by copolymerizing β -CD and α -Alk- β -CD with GMA onto the pretreated capillary by a simple one-pot strategy. 1 H NMR, SEM, FT-IR, TGA and BET surface area analyses were applied to characterize the prepared monolithic columns. The monoliths were evaluated on the enantioseparations of antibiotic drugs, antihistamine drugs, anticholinergic agents, antifungal drugs and pesticides. In contrast to the native β -CD monolith, the derived α -Alk- β -CD reveals significantly improved enantiodiscrimination performance for the analytes especially for pesticides. Through run-to-run (n = 6), day-to-day (n = 9), and column-to-column (n = 9) investigations, the RSDs values were all lower than 3.72 %. Molecular simulation reveled that the chiral recognition between α -Alk- β -CD and chiral drugs was an exothermic process mainly governed by interaction hydrogen bindings, resulting in different binding strength between a pair of isomers compounds and α -Alkenyl- β -CD, and then leading to different migration and finally achieving effective chiral separation.

Zeolite-supported nanoscale zero-valent iron: New findings on simultaneous adsorption of Cd(II), Pb(II), and As(III) in aqueous solution and soil

Zhangtao Li,Lu Wang,Jun Meng,Xingmei Liu,Jianming Xu,Fan Wang,Philip Brookes

Nanoscale zero-valent iron (NZVI) has a high adsorption capacity for heavy metals, but it forms aggregates easily. In this study, zeolite-supported nanoscale zero-valent iron (Z-NZVI) was synthesized from a simplified liquid-phase reduction of iron(III) salts which simultaneously adsorbed As(III), Cd(II) and Pb(II) from aqueous solution and soil. Scanning electron micrographs showed that aggregation was eliminated and the NZVI evenly dispersed onto the surface of zeolite. FTIR spectra reveal that NZVI was protected from oxidization on the surface of Z-NZVI. XRD and XPS patterns confirmed the formation of Cd(OH) 2 , Pb 0 , and FeAsO 4 in Z-NZVI after adsorption. The experimental maximum adsorption capacity of Z-NZVI was 11.52   mg As(III)/g, 48.63   mg Cd(II)/g, and 85.37   mg Pb(II)/g at pH 6, respectively, much higher than that of zeolite. Batch experiments indicate that various adsorption mechanisms including electrostatic adsorption, ionic exchange, oxidation, reduction, co-precipitation, and complexation coexisted with the selected heavy metals. Due to the formation of multiphase compounds on the Z-NZVI, the synergy and competition among heavy metals were concurrent. Most arsenic, cadmium and lead in the soil samples were immobilized after mixing with 30   g/kg Z-NZVI. These results suggest that Z-NZVI has great potential for treating water and soil multi-contaminated with heavy metals.

Mn-embedded biochar for enhanced removal of Cd(II), Pb(II) and Ni(II): Physicochemical properties, high-efficiency adsorption capacities and quantitative mechanism analysis

Yipeng Wang,Kun Wang,Xuchan Wang,Qingliang Zhao,Junqiu Jiang,Ruiyuan Xue,Luzi Yuan

Heavy metals (HMs) in wastewater, including Cd, Pb and Ni, were toxic and needed urgent treatment. Using biochar as an adsorbent to purify HM-containing wastewater is effective. However, there are few studies on screening of high-efficiency modifier and comparing their adsorption capacity. Herein, three different modification methods, including heteroatomic doping (urea), alkali hydroxide (NaOH) and chemical oxidation (KMnO 4 ), were used to improve removal ability of HMs by biochar. The difference in impregnation solution resulted in completely differences in microscopic morphology, physicochemical properties and adsorption efficiency of modified biochar. Biochar modified by KMnO 4 (Mn-BC) had significantly better adsorption capacity for Cd, Pb and Ni, reaching 46.40 mg/g, 80.20 mg/g and 18.65 mg/g, respectively, compared with raw biochar and other modification biochar, which might be due to the highest surface area and pore volume, lower zeta potential and loaded MnO x onto Mn-BC surface. Chemical and monolayer adsorption was dominant during adsorption of HMs. After adsorption, HMs were detected on the Mn-BC surface in the form of carbonate, hydroxide or oxide. Mineral precipitation and cation exchange were the dominant mechanisms during adsorption, accounting for 17.4%-41.8% and 43.0%-77.2%, respectively. Moreover, according to the correlation analysis, the increase in biochar pH, pore volume and degrees of carbonization were beneficial for HM adsorption. Mn-BC could adapt to a wider pH range (pH=4–6), and its adsorption capacity would not be interfered by coexisting ions (50 mg/L). This research proved advantages of biochar with KMnO 4 modification and highlighted its application in treatment of wastewater contaminated with multiple HMs.

Easily recoverable Cd x Zn1−x S-Gel photocatalyst with a tunable band structure for efficient and stable H2 production mediated by visible light

Wu Yongli,Gao Jianping,Hao Chaoyue,Mei Shunkang,Yang Jiangbing,Wang Xiaoxue,Zhao Ruiru,Zhai Xiangang,Liu Yu

A photocatalyst consisting of a cellulose hydrogel loaded with Cd x Zn 1− x S (Cd x Zn 1− x S-Gel) was prepared, and its photocatalytic water splitting activity was studied. At room temperature, the Cd x Zn 1− x S particles with an average size of about 3 nm were loaded in carboxymethyl cellulose hydrogel by an in situ chemical reaction. This synthesis method was simple and repeatable. Diffuse reflectance UV–vis results showed that it is possible to adjust the optical properties of the synthesized photocatalysts by adjusting their composition. Under visible light irradiation, the hydrogen production rate of the photocatalysts was greatly improved. In the absence of a co-catalyst, Cd 0.2 Zn 0.8 S-Gel obtained the highest hydrogen production rate of 1762.5 μmol g −1  h −1 , which is almost 104 times of that of the pure CdS. Moreover, after four hydrogen production cycles, the hydrogen production rate did not decrease significantly, showing excellent stability. It is noteworthy that the Cd x Zn 1− x S-Gel can easily be removed from the aqueous solution after hydrogen production. This is a new approach for manufacturing easy recoverable visible-light-driven photocatalysts, which is vital for hydrogen production through a “green” process.