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Background: The use of modified electrochemical sensors is essential for the detection of antibiotic drug abuse. The main objective of this article is to develop a silk-derived carbon material for the modification of pyrolytic graphite electrodes (PGE) for the sensitive detection of chloramphenicol (CAP). Methods: We proposed a pyrolysis synthesis of porous carbon nanosheets (Fe-Silk PNC) using silk as a precursor. Properties of carbon nanosheets had been improved by the Fe-Nx atoms doping, which was attributed to the β-sheet structures and amino-group-rich chemical structures of silk fibroin, and this material has been used to modify the pyrolytic graphite electrode (PGE) for the electrochemical determination of CAP. Scanning electron microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FT-IR) were used to determine the morphology and properties of Fe-Silk PNC surface. In the electrochemical determination, cyclic voltammetry (CV) showed a superior current response while bare electrode performed an inferior result. In addition, different scan rate, pH, accumulation time and accumulation potential were carefully optimized, which proved that this material is appropriate for CAP detection. Finally, differential pulse voltammetry (DPV) method was used for quantitative measurements. Result: In this study, DPV determination of CAP showed the linear relationship with increasing concentration ranged from 1 to 200 μM, and the low detection limit was 0.57 μM (S/N = 3). SEM and FT-IR results further demonstrated the N-doped carbon nanomaterials were successfully synthesized. With excellent sensing performance achieved, the practicability of the sensor has been evaluated to detect CAP in chicken, shrimps and fish. Conclusion: In summary, a silk derived biomass porous carbon nanomaterial Fe-Silk PNC was simply fabricated and used as a novel electrode material. This kind of novel Fe-Silk PNC modified electrode exhibited excellent sensitivity, anti-interference ability, repeatability, wide linear rang, and was successfully used for determination of CAP in real samples. Therefore, the biomass derived nanomaterial is expected to be used in new sensing materials.

The overdose of acetaminophen (AP) can cause serious acute liver injury even the irreversible liver necrosis. The quantitative detection of AP is of great significance not only for clinical applications but also for the quantity control of its pharmaceutical formulations. In this paper, a sensitive molecularly imprinted voltammetric sensor towards AP was constructed based on synergistic enhancement of nitrogen-vacancy graphitized carbon nitride (NV-g-C

A novel and practical palladium-catalyzed aerobic oxyarylthiolation of alkynone O-methyloximes for the assembly of 4-sulfenylisoxazole derivatives using S8 and arylhydrazines as the S-aryl sources is accomplished. In the presence of 0.1 mol% of IPr-Pd-allyl-Cl as the catalyst and O2 (1 atm) as the sole oxidant, both alkynone O-methyloximes and arylhydrazines are suitable substrates, delivering diverse 4-sulfenyl isoxazoles in moderate to good yields with good functional group tolerance. Notably, the phenyl diazonium salt and sodium phenyl sulfinate are also suitable arylation reagents, providing an alternative synthetic strategy to access structurally diverse 4-sulfenyl isoxazoles.

Graphite nitride carbon nanosheets have received more and more attention toward the photocatalytic research and applications. Ultrathin g-CN nanosheets with porous structure were synthesized successfully by thermal calcination of melamine supramolecular complexes, which was obtained by pre-treating melamine in nitric acid solution at different concentrations (0.5–2 mol/L). Effects of HNO3 pre-treatment on the microstructure of supramolecular complexes were studied. The characteristics of g-CN nanosheets were investigated by X-ray diffractometry, X-ray photoelectron spectroscopy, transmission electron microscopy and Fourier transform infrared spectroscopy. The degradation performance for RhB and water splitting hydrogen production performance were used to evaluate the photocatalytic performances of g-CN nanosheets. The morphology and microstructure of HNO3/melamine supramolecular complexes are different from those of melamine precursor due to the better arrangement of the melamine units. Ultrathin porous g-CN nanosheets which possess a thickness of less than 2 nm were successfully prepared by calcination of melamine pre-treated with 1.0 mol/L nitric acid. The g-CN(1.0) nanosheets possess the highest photocatalytic degradation performance and water splitting hydrogen production performance due to the effective separation of photogenerated carriers and high specific surface area providing a large number of active sites.

In clinical practice, the excess concentration of bilirubin can trigger diseases such as neonatal jaundice, hepatic failure, septicemia, and so on. The concentration of bilirubin is one of important clinical indexes to evaluate patients with hepatic function disease in clinical practice. Therefore, it is very necessary to develop a rapid detection technique detecting the bilirubin in body fluids. Here, a new electrochemical sensor based on Au nanoparticles/tetrathiafulvalene-carboxylate functionalized reduced grapheneoxide 0D-2D heterojunction(AuNPs/TTF-COOH/RGO) was fabricated for the discrimination of bilirubin in real human blood. The TTF-COOH could effectively repair electron conductivity of RGO nanosheets, decrease interface resistance, and also enhance the dispersity of TTF-COOH/RGO nanosheets in water. What's more, the S atoms of TTF-COOH can bonding the gold nano-particles (AuNPs) to fabricate a 0D-2D heterojunction with excellent biocompatibility and enhanced specific surface area. After bilirubin oxidases were self-assembled on the surface of AuNPs, a specific recognition interface was formed as a sensor for the detection of bilirubin. The heterojunction showed enhanced interface electron transfer rate, excellent biocompatibility, and also prominent electrocatalytic activity for the high efficiency catalysis of bilirubin. The sensor shows a linear response for bilirubin from 2.66 to 83 μmol L−1 and a low detection limit of 0.74 μmol L−1 at 3σ. This work provides one novel approach to detection of bilirubin by functional RGO nanosheets, and broadens the application area of RGO nanosheets in selective catalysis and detection of biomolecule in biological specimens, such as blood, urine.

Trace amounts of Co3O4 modified TiO2 nanorod arrays were successfully fabricated through the photochemical deposition method without adding any nocuous reagents. The Co3O4/TiO2 nanorod arrays fabricated in acid solution had the highest photo-electrochemical activity. We elaborated on the mechanism of Co3O4-TiO2 fabricated in different pH value solutions. The Co3O4-TiO2 had a more remarkable photo-electrochemical performance than the pure TiO2 nanorod arrays owing to the heterojunction between Co3O4 and TiO2. The degradation of methylene blue and hydroquinone was selected as the model reactions to evaluate the photo-electrochemical performance of Co3O4-TiO2 nanorod arrays. The Co3O4/TiO2 nanorod arrays had great potential in waste water treatment.

Trace amounts of Co3O4 modified TiO2 nanorod arrays were successfully fabricated through the photochemical deposition method without adding any nocuous reagents. The Co3O4/TiO2 nanorod arrays fabricated in acid solution had the highest photo-electrochemical activity. We elaborated on the mechanism of Co3O4-TiO2 fabricated in different pH value solutions. The Co3O4-TiO2 had a more remarkable photo-electrochemical performance than the pure TiO2 nanorod arrays owing to the heterojunction between Co3O4 and TiO2. The degradation of methylene blue and hydroquinone was selected as the model reactions to evaluate the photo-electrochemical performance of Co3O4-TiO2 nanorod arrays. The Co3O4/TiO2 nanorod arrays had great potential in waste water treatment.

Mechanical failure of components used in microelectronic systems is attributed to thermal stress involving temperature fluctuations, which can be eliminated by matching the coefficient of thermal expansion (CTE) of the component parts. Low CTE and high thermal conductivity (TC) 3D-SiC/Al-Si-Mg interpenetrating composites (IPCs) with monomodal or multimodal SiC distribution were fabricated by pressurelessly infiltrating Al-15Si-10Mg into high loading 3D-SiC preforms made from either a single SiC particle size or mixed SiC particles with different sizes of F220, F800 and F1000 mesh, respectively. The effect of monomodal and multimodal SiC distribution on the TC, CTE and bending strength (BS) of the IPCs were carefully studied. In general, 3D-SiC/Al-Si-Mg IPCs with optimized multimodal SiC distribution show better comprehensive properties than 3D-SiC/Al-Si-Mg IPCs with monomodal SiC distribution. The highest TC of 233.22 W/(m °C) and BS of 283 MPa as well as lower CTE of 6.32 × 10−6 °C−1 were obtained with the bimodal 3D-SiCF220/800/Al-Si-Mg IPC having a total 73% volume fraction of F220 and F800 SiC. The use of finer F1000 SiC particles in the high loading 3D-SiC preforms could lead to finer SiC particles agglomeration and not well filling in the free space left by coarse SiC network, which result in the microstructural non-uniformity, excessive Mg2Si and retained pores in the prepared IPCs causing the weakening of strength and TC of the IPCs. A significant reduction in CTE of 5.68 × 10−6 °C−1 was achieved on trimodal 3D-SiCF220/800/1000/Al-Si-Mg IPC having a total 79% SiC volume fraction. Moreover, a new model to predict the CTE of IPC based on its 3D interpenetrating network characteristics is proposed which fits well with the experimental CTE data of the IPCs.

Novel TiO2 nanotube arrays (TiO2 NTAs) with preferred oriented crystalline structure were firstly achieved by a facile method through anodizing Ti sheets with textured microstructure. Highly oriented crystalline structure of TiO2 NTAs, with its (004) lattice plane of anatase TiO2 paralleling to the top surface of TiO2 NTAs was identified by the results of XRD, which was further confirmed by the regular diffraction spots and lattice fringes with uniform direction in HRTEM images. In comparison with normal randomly oriented TiO2 NTAs, the quasi-single crystal structure of highly oriented TiO2 NTAs can suppress the recombination of photogenerated electron–hole pairs and enhance the transfer of photocarriers, as was proved by the photoelectrochemical measurement conducted on both normal TiO2 and oriented TiO2 NTAs. The results of this study provide a promising avenue to obtain high photoelectrochemical performance TiO2 NTAs-based hybrid nanomaterials.

3D-SiC/Al-Si-Mg interpenetrating composites (IPCs) were fabricated by pressureless infiltration method. Interfaces in the 3D-SiC/Al-Si-Mg IPCs were modificated by using two different kinds of aluminum alloy Al-15Si-10Mg and Al-9Si-6Mg to infiltrate into 3D-SiC performs and different treated 3D-SiC preforms unoxidized or preoxidized in air at 1000 °C, 1100 °C and 1200 °C for 2 h respectively. Results showed that desired interfaces can be achieved in both IPCs made with those two aluminum alloys, as demonstrated by their excellent comprehensive properties. When the Al-15Si-10Mg alloy with excessive Si content is used for infiltration, interfaces in 3D-SiC/Al-Si-Mg IPC fabricated with the unoxidized 3D-SiC preform are directly bonded through atomic matching without any interfacial reaction and the composite has the properties of a thermal conductivity (TC) of 224.5 W/(m °C), a thermal expansion coefficient (CTE) (RT ~ 300 °C) of 7.04 × 10 −6 /°C and a bending strength (BS) of 277 MPa. When the Al-9Si-6Mg alloy with a lower Si content is used for infiltration, interface zone with a thickness around 200 nm forms in the 3D-SiC/Al-Si-Mg IPC fabricated with the 3D-SiC preform preoxidized at 1000 °C. The reaction-bonded interface is composed of AlN and MgAl 2 O 4 which have better interface affinity with SiC and can isolate SiC effectively from liquid Al against the formation of detrimental Al 4 C 3 phase. The composite has the properties of a TC of 219.5 W/(m °C), a CTE (RT ~ 300 °C) of 7.66 × 10 −6 /°C and a BS of 318 MPa.

Aflatoxin B(1) (AFB(1)), one of most potent and common mycotoxins in human food and animal feed, has hepatotoxic and carcinogenic effects on humans and poultry. Recent studies indicated that selenium (Se) has a protective effect on apoptosis induced by toxin poisoning. The present study was designed to reveal the ameliorative effects of selenium on the expression of apoptosis related molecules in the jejunum of broilers exposed to an AFB(1) diet for 3 weeks. A total of 216 one-day-old healthy Cobb broilers were randomly divided into the control group (0 mg kg(–1) AFB(1)), AFB(1) group (0.6 mg kg(–1) AFB(1)), AFB(1) + Se group (0.6 mg kg(–1) AFB(1) + 0.4 mg kg(–1) supplement Se) and Se group (0.4 mg kg(–1) supplement Se), respectively. TUNEL and flow cytometry assays both indicated that 0.4 mg kg(–1) selenium could ameliorate excess apoptosis caused by AFB(1) in jejunal cells. Moreover, the expressions of FAS, FASL, TNF-α, TNF-R1, CASPASE-3, CASPASE-8, CASPASE-10, GRP78 and GRP94 analyzed by qRT-PCR demonstrated that 0.4 mg kg(–1) selenium restored these parameters to be close to those in the control group. In summary, supplementation of selenium at a concentration of 0.4 mg kg(–1) selenium could protect the chicken's jejunum from excess apoptosis caused by 0.6 mg kg(–1) AFB(1) through down-regulating the expression of death receptor pathway and endoplasmic reticulum pathway related molecules. According to this conclusion, this study may contribute to a better understanding of selenium's protective role against AFB(1) poisoning.

The development of efficient solar driven catalytic system for the degradation of antibiotics has become increasingly important in environmental protection and remediation. Non-noble-metal NiS and MoS2 nanosheet co-modified graphitic C3N4 ternary heterostructure has been synthesized via a facile combination of hydrothermal and ultrasound method, and the ternary heterostructure has been utilized for photocatalytic degradation of antibiotic agents. The antibiotics of ciprofloxacin (CIP) and tetracycline hydrochloride (TC) were photodegraded by the hybrid under the visible light. The optimal photodegradation rate of the ternary heterostructure reaches about 96% after 2h irradiation, which is 2.1 times higher than that of pure g-C3N4 for TC degradation. The photocatalytic degradation rates of the ternary heterostructure for both CIP and TC obey the pseudo-first-order kinetic model. The enhanced visible light adsorption and charge separation efficiency contribute to the photocatalytic performance of the ternary heterostructure. This work provides new insights and pathways by which efficient degradation of antibiotics can be achieved and will stimulate further studies in this important field.

MicroRNAs (miRNAs) play an important role in multiple biological processes and can be used as biomarkers for clinical disease diagnosis, so their detection is of great importance. Here, manganese dioxide (MnO2) nanosheet acts as carrier to deliver DNAzyme probes into cells through endocytosis, where intracellular glutathione (GSH) reduces the MnO2 nanosheet to manganese ions (Mn2+) and releases the probes. The generated Mn2+ can be further used as an effective cofactor to activate the DNAzyme probe, and cleave the DNA strand into two fragments. Then, the miRNA-155 in the cells can hybridize with the cleaved fragment to cause the fluorescence signal change of the probe. The proposed proportional fluorescent method has been applied to the imaging of miRNA-155 in HeLa cells and HepG2 cells with the estimated detection limit (LOD) as 1.6 × 10−12 M. The new method can provide great help for cancer diagnosis and biological research related to miRNA.

The analysis of illicit drugs analysis is an important branch of modern forensic science with many legal and socially relevant implications in forensic investigations. In recent years, among all the techniques for analysis and detection of illicit drugs, electrochemical sensing technique has become a rapidly developed analysis and detection technology due to its numerous advantages (e.g., high precision, high sensitivity, fast respondability, easy functioning, portability, capability of miniaturization and automation, etc.). The performance of employed electrodes determines the performance of the sensor. To this end, material technology of modified electrode plays an important role in enhancing the sensing performance. The limited use of (nano)materials and technology in the forensic practice has been evidenced by the inadequate number of studies published on modified electrodes. Here, we offer a comprehensive review on the material technology of modifying electrodes for analysis and detection of illicit drugs. Especially, the synthesis and applicability of diverse materials, such as carbonaceous materials, metal (nano)materials, metal oxide (nano)materials, magnetic (nano)materials, conductive polymers, Schiff bases, hexacyanoferrates, metallophthalocyanines, cucurbiturides, and ionic liquids for modified electrodes in illicit drugs sensing are described in detail along with the sensor performance of sensitivity, accuracy, limit of detection, stability, and practicability. At last, this review offers prospects for the future research and development needed for modified electrodes sensing technology for the detection of illicit drugs.

Aflatoxin B1 (AFB1) is a natural product of the Aspergillus genus of molds, which grow on several foodstuffs stored in hot moist conditions, and is among the most potent hepatocarcinogens and immunosuppression presently known. The latter was related to the up-regulated apoptosis of immune organs. However, the effect of expression of death receptor and endoplasmic reticulum molecules in AFB1-induced apoptosis of chicken splenocytes was largely unknown. The objective of this study was to investigate this unknown field. One hundred and forty four one-day-old chickens were randomly divided into control group (0 mg/kg AFB1) and AFB1 group (0.6 mg/kg AFB1), respectively and fed with AFB1 for 21 days. Histological observation demonstrated that AFB1 caused slight congestion and lymphocytic depletion in the spleen. TUNEL and flow cytometry assays showed the excessive apoptosis of splenocytes provoked by AFB1. Moreover, quantitative real-time PCR analysis revealed that AFB1 induced the elevated mRNA expression of Fas, FasL, TNF-α, TNF-R1, Caspase-3, Caspase-8, Caspase-10, Grp78 and Grp94 in the spleen. These findings suggested that AFB1 could lead the excessive apoptosis and alter the expression of death receptor and endoplasmic reticulum molecules in chicken spleen.

Aflatoxin B1 (AFB1) is a common contaminant of poultry feeds in tropical and subtropical climates. Early researches have well established the hepatotoxic, carcinogenic, and immunotoxic effects of AFB1 on humans and animals. Recently, it has been shown that AFB1 could cause the up- or down-alteration of mitochondrial pathway molecule expression. However, the information on the expression of death receptor and endoplasmic reticulum molecules in the jejunal apoptosis induced by AFB1 were unavailable. So the present study was conducted to explore the expression of apoptotic molecules related to death receptor and endoplasmic reticulum in the jejunal cells of chickens exposed to AFB1 diet for 3 weeks. Total of 144 one-day-old chickens was randomly divided into two groups, namely control group (containing 0 mg/kg AFB1) and AFB1 group (containing 0.6 mg/kg AFB1). Histopathological observation and microscopic quantitative analysis revealed morphological changes in the jejunum such as the shedding of the mucosal epithelial cells in the apical region of villi along with the decrease of villus height, villus area and villus/crypt ratio in the AFB1 group. Both TUNEL and flow cytometry assays showed that AFB1 intake induced excessive apoptosis of jejunal cells. Quantitative real-time PCR test displayed the general upregulation of death receptors (FAS, FASL, TNF-α and TNF-R1), endoplasmic reticulum signals (GRP78 and GRP94) as well as initiator and executioner caspases (CASPASE-10, CASPASE-8 and CASPASE-3) in the jejunum of AFB1-intoxicated chickens. It's the first study demonstrating that AFB1 induced apoptosis of chickens' jejunum accompanied by the alteration of death receptor and endoplasmic reticulum molecule expression.

Aflatoxin B1 (AFB1) is the most toxic among the mycotoxins and causes detrimental health effects on human and animals. Selenium (Se) plays an important role in chemopreventive, antioxidant, anticarcinogen, and detoxification and involved in cell cycle regulation. The aim of this study was to explore the molecular mechanisms of selenium involved in inhibition of G2/M cell cycle arrest of broiler’s jejunum. A total of 240 one-day-old healthy Cobb broilers were randomly divided into four groups and fed with basal diet (control group), 0.6 mg/kg AFB1 (AFB1 group), 0.4 mg/kg Se (+Se group), and 0.6 mg/kg AFB1 + 0.4 mg/kg Se (AFB1 + Se group) for 21 days, respectively. The histological observation and morphological analysis revealed that 0.4 mg/kg Se prevented the AFB1-associated lesions of jejunum including the shedding of the apical region of villi, the decreased villus height, and villus height/crypt ratio. The cell cycle analysis by flow cytometry showed that 0.4 mg/kg Se ameliorated the AFB1-induced G2/M phase arrest in jejunal cells. Moreover, the expressions of ATM, Chk2, p53, Mdm2, p21, PCNA, Cdc25, cyclin B, and Cdc2 analyzed by immunohistochemistry and qRT-PCR demonstrated that 0.4 mg/kg Se restored these parameters to be close to those in the control group. In conclusion, Se promoted cell cycle recovery from the AFB1-induced G2/M phase arrest by the molecular regulation of ATM pathway in the jejunum of broilers. The outcomes from the present study may lead to a better understanding of the nature of selenium’s essentiality and its protective roles against AFB1.

// Chunyu Liu 1, 2, * , Zhicai Zuo 1, 2, * , Panpan Zhu 1, 2, * , Zhixiang Zheng 1, 2, * , Xi Peng 3 , Jing Fang 1, 2 , Hengmin Cui 1, 2 , Yi Zhou 4 , Ping Ouyang 2 , Yi Geng 2 , Junliang Deng 1, 2 and Yu Sun 2 1 Key Laboratory of Animal Diseases and Environmental Hazards of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, PR China 2 College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, PR China 3 College of Life Sciences, China West Normal University, Nanchong, Sichuan, PR China 4 Life Science Department, Sichuan Agricultural University, Yaan, Sichuan, PR China * These authors contributed equally to this work Correspondence to: Jing Fang, email: fangjing4109@163.com Xi Peng, email: pengxi197313@163.com Keywords: aflatoxin B 1 , selenium, IgA+ cell, immunoglobulin, cecal tonsil Received: February 06, 2017 Accepted: April 02, 2017 Published: April 13, 2017 ABSTRACT Aflatoxin B 1 (AFB 1 ), the most common mycotoxin in human food and animal feed, produces hepatotoxic, genotoxic and immunosuppressive effects in multiple species. Selenium (Se) has emerged as an important element in the dietary prevention of various toxic agents. The present study was designed to scrutinize the protective effects of sodium selenite on the histological lesions and suppression of mucosal humoral response in the cecal tonsil generated by AFB 1 . A total of 156 one-day-old broilers were divided into four groups and fed on basal diet (control group), 0.6 mg/kg AFB 1 (AFB 1 group), 0.4 mg/kg Se supplement (+Se group), and 0.6 mg/kg AFB 1 + 0.4 mg/kg Se supplement (AFB 1 +Se group) respectively for 21 days. Our results showed that 0.4 mg/kg Se supplement in broiler’s diets could improve the AFB 1 -induced histological lesions in the cecal tonsils including the depletion of lymphocytes in the lymphatic nodules as well as the shedding of microvilli in the absorptive cells. Moreover, Se could restore the decreased number of IgA+ cells and expression levels of pIgR, IgA, IgG, and IgM mRNA induced by AFB 1 to be close to those in the control group. These results demonstrated that 0.4 mg/kg supplemented dietary Se in the form of sodium selenite could protect the cecal tonsils from the histological lesions and suppression of the mucosal humoral response provoked by 0.6 mg/kg AFB 1 . Our study may provide new experimental evidences for better understanding of AFB 1 -induced damage of mucosal immunity and protective effect of Se against this toxin.

Anatase TiO 2 nanotube arrays were hydrothermally treated in Na 2 S solution, and the photoelectrochemical performances were systematically studied. Morphology, structure, elemental component and photoelectrochemical performances of TiO 2 were characterized by scanning electron microscope, high resolution transmission electron microscope, X-ray diffractometer, X-ray photoelectron spectrometer and electrochemical workstation, respectively. The influence of the sulfide treatment on the photoelectrochemical performance is discussed in detail by measuring cyclic voltammogram, chornoamperogram and chemical impedance spectrum of treated TiO 2 nanotube arrays in different conditions. TiO 2 nanotube arrays sulfide treated in 30 mM Na 2 S solution at 135 °C possess the highest photocurrent of 289 μA, which is 3.3 times that of untreated sample. High optical absorption, large electrochemical active surface area and rapid electron transfer rate due to the mesoporous structure rather than sulfide dropping play key roles in enhancing the photoelectrochemical activity of the TiO 2 nanotube arrays.

Graphitic C3N4/ultrathin MoS2 (MoS2/g-C3N4) hybrids were synthesized via a facile bathing and ultrasound method. In this process, a well-bonded interface structure was formed between ultrathin MoS2 nanosheets and g-C3N4 through adjusting the amount of MoS2 in the MoS2/g-C3N4 hybrids. The MoS2/g-C3N4 hybrids were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy (Raman), transmission electron microscopy (TEM) and UV-vis spectroscopy (UV-vis). The MoS2/g-C3N4 photocatalyst showed excellent photocatalytic activity in the photodegradation of organic pollutants. In this work, methyl orange (MO) was used as the simulative pollutant; the highest photodegradation rate (92.4%) was obtained when the amount of MoS2 was 5 wt% in the MoS2/g-C3N4 hybrids (0.05-MC), with a kinetic constant of 0.0189 min−1 after being irradiated under visible light for 2 h. Besides, 0.05-MC also showed excellent recyclability and chemical stability, and a photodegradation rate of 79.93% was reached after being reused 10 times. For practical pollutants, the photocatalytic degradation rates of ciprofloxacin (CIP) and tetracycline hydrochloride (TC) have been increased dramatically under the visible light irradiation. The excellent photocatalytic properties of MoS2/g-C3N4 hybrids can be ascribed to the enhanced separation rate and accelerated mobility of photogenerated charges through ultrathin MoS2 nanosheets’ modification.

In this work, a new platinum (Pt) nanoparticles-functionalized poly(diallyl dimethyl ammonium chloride) (PDDA)-diamond powder (DMP) composite-modified glassy carbon electrode (GCE) was fabricated for electrochemical sensing of the selective or simultaneous determination of bisphenol A (BPA) and bisphenol S (BPS). The Pt/PDDA-DMP hybrid was characterized by Scanning electron microscopy, Transmission electron microscope, Fourier transform infrared, X-ray diffraction analyzer. This hybrid exhibited remarkable electrocatalytic activity towards the oxidation of BPA and BPS. The simultaneous determination of BPA and BPS by cyclic voltammetry yielded a difference of 0.316 V, which was sufficiently large for their potential recognition and simultaneous detection in mixtures. Differential pulse voltammetry was successfully used to simultaneously quantify BPA and BPS within the concentration range of 5-30 and 10-60 mu M under optimal conditions, respectively. The detection limits (S/N = 3) of Pt/PDDA-DMP/GCE for BPA and BPS were 0.6 and 2.0 mu M, respectively. The fabricated electrode showed good sensitivity, stability, and selectivity. The proposed method was successfully applied to determine BPA and BPS in biological samples. (C) The Author(s) 2016. Published by ECS. All rights reserved.

Molybdenum-sulfur nanocube/poly(diallyl dimethyl ammonium chloride)-mesoporous carbon (MoS2/PDDA-MC) composites was synthesized via a convenient and low-cost synthesis approach, which was proposed for the development of a simple and novel sensitive electrochemical sensor for the determination of l -cysteine. The as-synthesized MoS2 nanoparticles shows a nanocube structure with a uniform size of about 20 nm. The photocurrent sign indicates that the MoS2 is the p-type compound. Due to large surface-to-volume ratio, high conductivity of mesoporous carbon, and good biocompatibility of MoS2, the MoS2/PDDA-MC based sensor exhibited excellent electrocatalytic activity for the detection of l -cysteine with a wide linear range from 0.45 μM to 155 μM and a low detection limit of 0.090 μM (S/N = 3). This work opens a new way to functionalized MC with good biocompatibility and solubility in sensors.

A multi-objective integrated arrival and departure aircraft sequencing model and algorithm were presented in this paper to enhance the runway capacity, improve the operational efficiency and mitigate the accumulation and propagation of flight delays. Firstly, an integrated arrival and departure sequencing model was constructed based on the multiple runway operating modes, wake separation, release separation and the sequential flights. Secondly, a multi-objective simulated annealing algorithm using Pareto-domination based acceptance criterion (PDMOSA) was employed to solve the integrated arrival and departure aircraft sequencing problem with two objectives — maximizing runway operational capacity and minimizing flight delays of the sequential flights. In this algorithm, the arrival priority strategy of sequential flights was introduced into the neighborhood search process. Finally, Shanghai Pudong International Airport was chosen to design simulation scenarios and arrival and departure flights in rush hours were taken as examples to carry out the simulation validation. And the results not only indicate the effectiveness of the proposed model and algorithm, but also show the arrival and departure delay of sequential flights are reduced when taking the influence of sequential flights into consideration.

Highly ordered TiO 2 nanotube arrays (TiO 2 NTAs) have been fabricated by the potentiostatic anodization method with Ti foils. Pt nanoparticles have been successfully deposited onto TiO 2 NTAs by UV light photoreduction method. In this work, X-ray diffraction, field emission scanning electron microscope, high resolution transmission electron microscopy, X-ray photoelectron spectroscopy, ultraviolet-visible spectroscopy and energy dispersive X-ray spectrometer methods were adopted to characterize the samples. The influence of different concentration of H 2 PtCl 6 precursor solution on the morphology and photocatalytic performances of samples was discussed. The SEM observations showed that Pt nanoparticles distributed on the wall of TiO 2 nanotubes uniformly. UV–vis spectra analysis showed that the light absorption of Pt/TiO 2 NTAs has been extended to the visible light range. When the concentration of H 2 PtCl 6 was 3 mM, the prepared sample showed the highest photodegradation rate. After irradiated under visible light for 2 h, the degradation rate of methyl orange solution reached 84.27%. Under the same condition, no obvious photodegradation of methyl orange was found for TiO 2 NTAs. Kinetic research showed that photodegradation process followed the first-order reaction, the apparent reaction rate constant of 3 Pt/TiO 2 NTAs was 1.493 × 10 −2 min −1 .

Immobilized TiO2 nanotube arrays (NTAs) co-modified with Pt and CdS nanoparticles were fabricated by using the combination of photoreduction and chemical bath deposition methods. XRD, SEM, TEM, XPS, UV-Vis and EDX methods were employed to characterize the microstructure and composition of samples, and the results showed that CdS and Pt NPs were uniformly deposited on the surface of TiO2 nanotubes. The CdS/Pt/TiO2 NTAs exhibited a much higher photocatalytic activity compared to pure TiO2 NTAs and binary CdS (or Pt)/TiO2 NTAs under visible light irradiation. A kinetic study showed that the rate constants of Pt/TiO2, CdS/TiO2 and CdS/Pt/TiO2 NTAs are 0.00736, 0.01717 and 0.02077 min(-1), respectively, revealing a remarkable kinetic enhancement in the ternary heteronanostructures due to the synergistic effect of the three components. Besides, the CdS/Pt/TiO2 NTAs exhibit high stability after being used 22 times. Thus we proposed that such ternary heteronanostructures show great promise as immobilized catalysts for high efficient visible-light-driven photocatalysis.

Palladium nanoparticles were dispersed on the surface of poly (diallyl dimethyl ammonium chloride) - mesoporous carbon (Pd/PDDA-MC) composite as a catalytic for the environmental hormones nonylphenol (NOP) electrochemical oxidation. The Pd/PDDA-MC was characterized by transmission electron microscope (TEM), scanning electron microscopy (SEM), which indicated that the assynthesized Pd nanoparticles were successfully dispersed on the surface of PDDA-MC nanocomposite. The electrochemical behavior of NOP was investigated on Pd/PDDA-MC modified GCE by cyclic voltammetry, differential pulse voltammetry. Electrochemical study has proved that the Pd/PDDA-MC nanocomposite shown excellent electro-catalytic activities toward the oxidation of NOP. The excellent reproducibility, stability and selectivity of the Pd/PDDA-MC modified GCE make it as a potential electrochemical sensor candidate for determination of environmental hormones in biology samples. (C) The Author(s) 2015. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse of the work in any medium, provided the original work is properly cited. All rights reserved.