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Objective: Triple-negative breast cancer (TNBC) patients with truly chemosensitive disease still represent a minority among all TNBC patients. The aim of the present study is to identify microRNAs (miRNAs) that correlate with TNBC chemoresistance. Methods: In this study, we conducted miRNAs profile comparison between triple-negative breast cancer (TNBCs) and normal breast tissues by microRNA array. Quantitative real-time PCR (qRT-PCR) was utilized to confirm the specific deregulated miRNAs change trend. We used starBase 2.1 and GOrilla to predict the potential targets of the specific miRNAs. Cells viability and apoptosis assays were employed to determine the effect of alteration of the specific miRNAs in TNBC cells on the chemosensitivity. Results: We identified 11 specific deregulated miRNAs, including 5 up-regulated miRNAs (miR-155-5p, miR-21-3p, miR-181a-5p, miR-181b-5p, and miR-183-5p) and 6 down-regulated miRNAs (miR-10b-5p, miR-451a, miR-125b-5p, miR-31-5p, miR-195-5p and miR-130a-3p). Thereafter, this result was confirmed by qRT-PCR. We predicted the potential targets of the candidate miRNAs and found that they are involved in cancer-associated pathways. For the first time, we found that miR-130a-3p and miR-451a were down-regulated in TNBC. 9 of the 11 specific deregulated miRNAs were found to be associated with chemoresistance. In vitro assays, we found that up-regulation of either miR-130a-3p or miR-451a in MDA-MB-231 cells significantly changed the cells sensitivity to doxorubicin. The results suggest that TNBC chemotherapy might be affected by a cluster of miRNAs. Conclusion: The abnormal expression miRNAs in TNBC are mainly chemoresistance related. This might be part of reason that TNBC likely to evade from chemotherapy resulting in early relapse and high risk of death. To alter their expression status might be a potential therapeutic strategy to improve the outcome of chemotherapy for TNBC patients. [ABSTRACT FROM AUTHOR]

The syntheses and structures of heteroleptic germanium(II) and tin(II) chlorides supported by anionic ligands derived from 2,3-dimethyl-1,4-diaza-1,3-butadiene are described. The reaction of ArN=C(Me)C(Me)=NAr ( L, Ar = 2,6- iPr2C6H3) with MeLi in Et2O, followed by treatment with GeCl2 ·dioxane or SnCl2, afforded [ L1ECl] [ L1 = ArN=C(Me)C(Me)2NAr; E = Ge ( 1), Sn ( 2)]. Moreover, L2Li [ L2 = ArN=C(Me)C(=CH2)NAr] reacted with GeCl2 ·dioxane in Et2O to form [{C(=CH)NAr}{C(Me)=NAr}]2(GeCl)2 ( 3). The byproducts are [{C(CH2)NAr}{C(Me)=NAr}Ge]2 ( 4) and L2H ( 5). Furthermore, the reaction of L with LiN iPr2 in Et2O, followed by treatment with SnCl2, afforded [ L2SnCl] ( 6). Compounds 1- 4 and 6 have been characterized by NMR spectroscopy and X-ray crystallography. [ABSTRACT FROM AUTHOR]

Thereaction of 1-phenyl-2-lithio-3,4-dimethylphosphole with W(CO)6at −90 °C followed by methyl triflate at roomtemperature gives the complex [(phosphol-2-yl)methoxycarbene]pentacarbonyltungsten(1). This complex reacts with sulfur to give the correspondingcomplex [methyl (phosphol-2-yl)thiocarboxylate]pentacarbonyltungsten(2), in which tungsten has migrated from the carbeneto phosphorus. The reaction of 3with alkynes at 90 °Cgives the corresponding phospholene-annelated cyclopentenones 5without the need for a nickel catalyst. In one case, anintermediate vinylketene rearranges by an intramolecular Diels–Alderreaction to give the tricyclic compound 6. All of theproducts have been characterized by X-ray crystal structure analysis. [ABSTRACT FROM AUTHOR]

Abstract: Training can induce significant changes in brain functioning and behavioral performance. One consequence of training is changing the pattern of brain activation. Abacus training is of interest because abacus experts gain the ability to handle digits with unusual speed and accuracy. However, the neural correlates of numerical memory in abacus-trained children remain unknown. In the current study, we aimed to detect a training effect of abacus-based mental calculations on numerical working memory in children. We measured brain functional magnetic resonance imaging (fMRI) activation patterns in 17 abacus-trained children and 17 control children as they performed two numerical working memory tasks (digits and beads). Functional MRI results revealed higher activation in abacus-trained children than in the controls in the right posterior superior parietal lobule/superior occipital gyrus (PSPL/SOG) and the right supplementary motor area (SMA) in both tasks. When these regions were used as seeds in a functional connectivity analysis of the resting brain, the abacus-trained children showed significantly enhanced integration between the right SMA and the right inferior frontal gyrus (IFG). The IFG is considered to be the key region for the control of attention. These findings demonstrate that extensive engagement of the fronto-parietal network occurs during numerical memory tasks in the abacus-trained group. Furthermore, abacus training may increase the functional integration of visuospatial-attention circuitry, which and thus enhances high-level cognitive process. [Copyright &y& Elsevier]

The psychometric properties of the Chinese Aggression and Victimization Scale (CAVS) were examined among 484 adolescents aged between 11 and 16 years. Confirmatory Factor Analysis (CFA) was applied and the goodness of fit of the model to the data was determined using multiple criteria. Results confirmed a two-factor structure which fitted well with the data. Cronbach's alpha coefficients for age and sex yielded evidence for good internal reliability with values ranging from 0.63 to 0.88 that were not affected by age or sex. The convergent validity was investigated by correlations among the CAVS and the CES-Depression for Children, Zung's Anxiety Scale, and the Self-Esteem Scale. Results showed that both subscales and the total scale were positively and significantly correlated with depression and anxiety, but negatively related to the Self-Esteem scale. The CAVS is a valid instrument for measuring aggressive behavior and victimization among adolescents. [ABSTRACT FROM PUBLISHER]

Highlights: [•] Rapid detection of protease activity with fairly good sensitivity and selectivity. [•] A turn-on fluorescence assay reduces the likelihood of false positive signals. [•] Cytochrome c efficiently quench the fluorescence of the FAM single stranded DNA. [•] The enzymatic reaction could be monitored in real-time. [•] The assay could be used for the screening of potential protease inhibitors. [Copyright &y& Elsevier]

Abstract: Ultrathin platinum-coated gold (Pt@Au) nanoparticles with core@shell structure have been developed by under-potential deposition (UPD) redox replacement technique. A single UPD Cu replacement with Pt2+ produced a uniform Pt monolayer on the surface of gold nanoparticles, which are immobilized on glassy carbon electrode (GCE) surface based on electrostatic interaction. The ultrathin Pt@Au nanoparticles were confirmed by cyclic voltammetry and X-ray photoelectron spectroscopy (XPS). Voltammetry and amperometric methodologies were used to evaluate the electrocatalytic activity of the Pt@Au nanoparticles modified electrode towards the reduction of hydrogen peroxide under the physiological condition. The present results show that ultrathin Pt coating greatly enhances the electrocatalytic activity towards the reduction of hydrogen peroxide, which can be utilized to fabricate the hydrogen peroxide sensor. Chronoamperometric experiments showed that at an applied potential of 0.08V (vs. Ag/AgCl), the current reduction of hydrogen peroxide was linear to its concentration in the range of 1–450μΜ, and the detection limit was found to be 0.18μM (signal-to-noise ratio, S/N=3). [Copyright &y& Elsevier]

ABSTRACT The versatility of a previously developed method for the synthesis of chiral carbene-based palladacycles is demonstrated through the synthesis of two new chiral pyridine-functionalized N-heterocyclic carbene palladacycles with different wingtip groups. The efficiency in their resolution with different counter anions and different chiral amino acid salt auxiliaries has been studied. The absolute stereochemistries of all the chiral compounds were confirmed by single crystal X-ray crystallography. An unexpected Pd-N bond cleavage that resulted in the racemization of the α-carbon center in these complexes has also been investigated. Chirality 25:149-159, 2013. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

This study investigates the psychometric properties of the E-Victimisation Scale (E-VS) and E-Bullying Scale (E-BS) designed to assess Cyber Bullying among Chinese adolescents. Participants were 484 adolescents aged between 11–16years randomly recruited from high schools within a region. Exploratory Factor Analysis (EFA) and Confirmatory Factor Analysis (CFA) were applied to investigate the factorial structure of these scales. Reliability was examined by Cronbach’s alpha coefficients by sex. The convergent validity was investigated by correlations among these scales and the Centre for Epidemiological Studies-Depression for Children as well as the Zung’s Anxiety Scales. A single-factor model for the E-VS and a 2-factor model for the E-BS were resulted from the EFA with large factor loadings and about 47% and 56% of variance explained respectively. Cronhach’s alpha values provided evidence for good internal reliability with values ranging from 0.55 to 0.96. Correlations between the E-VS and Depression as well as Anxiety scales showed positive and significant relationships, however, the E-BS was only related to Depression. Psychometric evidence has shown that both E-VS and E-BS are valid instruments for measuring Cyber bullying behaviour and victimisation. Further studies are required on the test–retest reliability, discriminate validity, responsiveness, as well as normative information for standardisation. [Copyright &y& Elsevier]

Abstract: Ultralow Pt-loading bimetallic nanoflowers have been fabricated by Cu under-potential deposition and galvanic exchange process. Results show that these Pt monolayer coated Au nanoflowers have superior performance towards oxidation of formic acid through a dehydrogenation pathway. [Copyright &y& Elsevier]

The reaction of the tin(II) (iminophosphinoyl)(thiophosphinoyl)methanediide[(PPh2NSiMe3)(PPh2S)CSn:]2(1) with AdNCO (Ad = adamantyl), ArNCO (Ar =2,6-Pri2C6H3), and [RhCl(cod)]2in THF afforded [(PPh2NSiMe3)(PPh2S)C{C(O)N(Ad)}Sn:] (2), [(PPh2NSiMe3)(PPh2S)C¯{C(O)N(Ar)}Sn:] (3), and[(PPh2NSiMe3)(PPh2S)C{Rh(cod)}(SnCl)](4), respectively. Compounds 2–4have been characterized by NMR spectroscopy and X-ray crystallography. [ABSTRACT FROM AUTHOR]

Purpose: In this study, the authors aimed to identify speech information processed by a hearing aid (HA) that is additive to information processed by a cochlear implant (CI) as a function of signal-to-noise ratio (SNR). Method: Speech recognition was measured with CI alone, HA alone, and CI + HA. Ten participants were separated into 2 groups; good (aided pure-tone average [PTA]<55dB) and poor (aided PTA ≥ 55 dB) at audiometric frequencies > 1 kHz in HA. Results: Results showed that the good-aided PTA group derived a clear bimodal benefit (performance difference between CI + HA and CI alone) for vowel and sentence recognition in noise, whereas the poor-aided PTA group received little benefit across speech tests and SNRs. Results also showed that a better aided PTA helped in processing cues embedded in both low and high frequencies; none of these cues was significantly perceived by the poor-aided PTA group. Conclusions: The aided PTA is an important indicator for bimodal advantage in speech perception. The lack of bimodal benefits in the poor group may be attributed to the nonoptimal HA fitting. Bimodal listening provides a synergistic effect for cues in both low- and high-frequency components in speech. [ABSTRACT FROM AUTHOR]

Purpose: In this study, the authors aimed to identify speech information processed by a hearing aid (HA) that is additive to information processed by a cochlear implant (CI) as a function of signal-to-noise ratio (SNR). Method: Speech recognition was measured with CI alone, HA alone, and CI + HA. Ten participants were separated into 2 groups; good (aided pure-tone average [PTA]<55dB) and poor (aided PTA ≥ 55 dB) at audiometric frequencies > 1 kHz in HA. Results: Results showed that the good-aided PTA group derived a clear bimodal benefit (performance difference between CI + HA and CI alone) for vowel and sentence recognition in noise, whereas the poor-aided PTA group received little benefit across speech tests and SNRs. Results also showed that a better aided PTA helped in processing cues embedded in both low and high frequencies; none of these cues was significantly perceived by the poor-aided PTA group. Conclusions: The aided PTA is an important indicator for bimodal advantage in speech perception. The lack of bimodal benefits in the poor group may be attributed to the nonoptimal HA fitting. Bimodal listening provides a synergistic effect for cues in both low- and high-frequency components in speech. [ABSTRACT FROM AUTHOR]

Abstract: Four new polyphenols namely excoecariphenols A–D (1–4) were isolated from the Chinese mangrove plant Excoecaria agallocha L. together with 23 known phenolic compounds. The structures of new compounds were elucidated on the basis of extensive spectroscopic analyses including IR, MS, NMR, and CD data. Excoecariphenols A and B presented as the unusual flavane-based 1-thioglycosides. Part of the isolated polyphenols were tested against hepatitis C NS3-4A protease and HCV RNA in huh 7.5 cells. Excoecariphenol D, corilagin, geraniin, and chebulagic acid showed potential inhibition toward HCV NS3-4A protease with IC50 values in a range of 3.45–9.03μM, while excoecariphenol D and corilagin inhibited HCV RNA in huh 7.5 cells significantly. A primary structure–activity relationship (SAR) is discussed. [Copyright &y& Elsevier]

Abstract: The reaction of [Cp∗IrCl2]2 (Cp*= η 5 −C5Me5) with the tridentate 3-thiapentane-1,5-dithiolate ligand, S(CH2CH2S−)2 (tpdt), led to the formation of [Cp∗Ir(η 3 −tpdt)] (1) in 81% isolated yield. Subsequent reactions of 1 with [Cp∗IrCl2]2 in 2:1 and 1:1 molar equiv ratios resulted in the formation of [Cp∗Ir(μ − η 2:η 3 −tpdt)Cp∗IrCl][PF6] (2) and [Cp∗Irμ − η 2:η 3 −tpdt)Cp∗IrCl][Cp∗IrCl3] (3) in 86 and 79% yields, respectively, based on 1, whereas the reactions of 1 with [(COD)IrCl]2 (COD=1,5-cyclooctadiene) in 2:1 and 1:1 molar equiv ratios resulted in the formation of the homo-bimetallic derivatives Cp∗Ir(μ − η 1:η 3 −tpdt)(COD)IrCl (4) (92% yield) and [Cp∗Ir(μ − η 2:η 3 −tpdt)(COD)Ir] [(COD)IrCl2] (5) (82% yield). Reactions between 1 and [(COD)RhCl]2, yielded the hetero-bimetallic derivatives Cp∗Ir(μ − η 1:η 3 −tpdt)(COD)RhCl (6) and [Cp∗Ir(μ − η 2:η 3 −tpdt)(COD)Rh][(COD)RhCl2] (7), in 92 and 93% yields, respectively. The reaction of 1 with methyl iodide gave mono-methylated derivative [Cp∗Ir(η3-C4H8S3Me)]I (8) (93% yield). All these compounds have been comprehensively characterized. [Copyright &y& Elsevier]

Abstract: Chemical examination of a Chinese soft coral Sinularia rigida resulted in the isolation and characterization of 19 new cembrane-type diterpenoids, designated as sinulariols A–S (1–19). Their structures were determined on the basis of extensive spectroscopic (2D NMR, IR, and MS) analysis in association with modified Mosher’s method. All compounds featured unusual 19-oxygenated functionalities, which are rarely found from cembranoid family. The biogenetic transformation of the isolated compounds is postulated. Part of the isolated cembranoids showed significant anti-fouling activity. [Copyright &y& Elsevier]

Objective: The full benefit of bilateral cochlear implants may depend on the unilateral performance with each device, the speech materials, processing ability of the user, and/or the listening environment. In this study, bilateral and unilateral speech performances were evaluated in terms of recognition of phonemes and sentences presented in quiet or in noise. Design: Speech recognition was measured for unilateral left, unilateral right, and bilateral listening conditions; speech and noise were presented at 0°° azimuth. The ''binaural benefit'' was defined as the difference between bilateral performance and unilateral performance with the better ear. Study sample: Nine adults with bilateral cochlear implants participated. Results: On average, results showed a greater binaural benefit in noise than in quiet for all speech tests. More importantly, the binaural benefit was greater when unilateral performance was similar across ears. As the difference in unilateral performance between ears increased, the binaural advantage decreased; this functional relationship was observed across the different speech materials and noise levels even though there was substantial intra- and inter-subject variability. Conclusions: The results indicate that subjects who show symmetry in speech recognition performance between implanted ears in general show a large binaural benefit. Sumario Objetivo: Se estudiaron los datos audiolóógicos de investigacióón epidemiolóógica basada en una poblacióón de adultos mayores. Se buscaron diagnóósticos especííficos de alteraciones otolóógicas y audiolóógicas que pueden ocasionar hipoacusia. Diseñño: Estudio retrospectivo de registros. Muestra: Se estudiaron tres cohortes etááreas, 474 individuos de 70 a 75 añños (''jóóvenes) y 252 individuos de 85 añños o mayores (''viejos''). Se utilizaron las audiometríías de tonos puros y de lenguaje. Se incluyeron los datos de sus expedientes méédicos. Resultados: Se diagnosticóó hipoacusia conductiva en 6.1% del grupo de ''jóóvenes'' y un 10.3% de los ''viejos''. Se establecieron diagnóósticos especfíícos (otitis media cróónica y otoesclerosis) en cerca de la mitad de los casos. Se diagnosticóó hipoacusia sensorineural no relacionada con la edad ni inducida por ruido en 3.4 y 5.2% de los casos. El 0.4% del grupo de ''jóóvenes'' y el 10% del grupo de ''viejos'' presentaban un reconocimiento del lenguaje severamente afectado, posiblemente relacionado con neuropatíía auditiva por edad. El 3.2% de las personas de 85 añños de edad presentaban sordera funcional bilateral, pero éésta no se presentóó en el grupo de 70--75 añños. Conclusiones: La incidencia de neuropatííaa auditiva probablemente relacionada con la edad aumenta considerablemente de los 70--75 añños a los 85. Existen marcadas diferencias en cuando a hipoacusia que afecta severamente la comunicacióón entre los grupos de ''jóóvenes'' y ''viejos'' en la poblacióón estudiada. [ABSTRACT FROM AUTHOR]

Abstract: This work reports the fabrication of hierarchical flowerlike platinum nanostructures (Pt nanoflowers, PtNFs) on a 3-aminopropyltriethoxysilane (APTES) monolayer and their electrocatalytic applications. The obtained PtNFs were characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), and electrochemical methods. The growth mechanism of the PtNFs may be attributed to the inhomogeneous diffusion of PtCl6 2− ions on the surface of the electrode. Moreover, it has been found that the PtNFs modified electrodes exhibit excellent electrocatalytic activity for the oxidation of methanol and the reduction of oxygen when compared to conventional Pt nanoparticle modified electrodes. The increased catalytic activity may be a result of the unique morphology of the PtNFs. [Copyright &y& Elsevier]

Abstract: Novel spindle-like polypyrrole hollow nanocapsules containing Pt nanoparticles (Pt NPs/PPy composite hollow nanospindles) were successfully prepared by using beta-akaganeite (β-Fe3+O(OH,Cl)) nanospindles as templates and methanoic acid as a reducing agent. The β-Fe3+O(OH,Cl) templates can be easily obtained in ethanol/water mixing solution in the presence of thiophene and FeCl3·6H2O, and after coating by PPy shell, they can be gradually and completely etched during the reduction of H2PtCl6 into Pt nanoparticles (Pt NPs) with the average size of 3.6nm on spindle-like polypyrrole hollow nanocapsules, which could still keep their integrality of morphologies with the thickness of PPy shell of 18–20nm. The investigation of Pt NPs/PPy composite hollow nanospindles modified glassy carbon electrode (GCE) for the application to detect nicotinamide adenine dinucleotide (NADH) with cyclic voltammetry (CV) and amperometry indicated good linearity and sensitivity of responses in the certain range of NADH concentration. The influence of Pt NPs content to the NADH oxidation current was also studied. This new kind of unique spindle-like noble metal/conducting polymer hollow nanostructured complex can be acted as a good steady electrode material for electrocatalytic oxidation of NADH. [Copyright &y& Elsevier]

Abstract: A hybrid bilayer membrane (HBM) has been prepared on a glassy carbon electrode (GCE). The HBM consists of an inner layer of n-hexadecylamine (HDA) covalently attached at the GCE and an out-layer of tetra-(N-hexadecylpyridiniurnyl)porphyrin (TC16PyP). The HDA was covalently bounded on the carbon surfaces through its primary amine under cyclic voltammetric potential scans forming a self-assembled monolayer (SAM). The TC16PyP forms a second layer on top of the HDA layer due to hydrophobic interaction. The TC16PyP/HDA/GCE assembly has been utilized to study ion transport through hybrid bilayer membranes. The ion transport through this porphyrin-terminated HBM has been found to strongly dependent on pH. It allows negatively charged redox ions, Fe(CN)6 3−, to penetrate at pH <6 while repelling positively charged Ru(NH3)6 3+. However, no faradaic current has been detected at pH >6 with either ions. We believe that electrostatic interaction between the redox ions and the charged membrane is the main reason for this pH dependent ion transport. [Copyright &y& Elsevier]

Abstract: Chemical examination of the stems and twigs of the mangrove plant Excoecaria agallocha L. resulted in the isolation of six ent-kaurane diterpenoids named agallochaols K–P (1–6), an atisane-type diterpenoid agallochaol Q (7), along with eight known diterpenoids (8–15). Their structures were elucidated on the basis of extensive spectroscopic analysis and by comparison of their NMR spectroscopic data with those reported in literature, in association with the biogenetic relationship with the X-ray structure of 9. Compounds 1, 5–7, 9–10, and 13 showed anti-inflammatory potency to suppress expression of NF-κB and AP-1 targeted genes including TNF-α and IL-6 induced by lipopolysaccharide (LPS) in mouse macrophages Raw 264.7 cells. In addition, compounds 1, 5–7, 9–10, and 13 block NF-κB activation, while compounds 1 and 7 block AP-1 activation dramatically, indicating these compounds possess an anti-inflammatory potential in vitro. [ABSTRACT FROM AUTHOR]

Fresh cut Granny Smith apple and iceberg lettuce were dipped in aqueous solutions of l -arginine at ambient pressure and assessed for browning on the cut surface during storage at 5 °C. Arginine delayed the development of browning and hence extended postharvest life. For apple slices, dipping in 50 mM arginine for 10 min resulted in a 15-fold increase in postharvest life over control slices. For lettuce pieces, the postharvest life was doubled by dipping in 100 mM arginine for 5 min. Arginine was found not to affect the taste of apple slices after a 250 mM dip and was more effective on a concentration basis than calcium ascorbate in inhibiting browning. Further studies are warranted to assess the suitability of arginine as a treatment to inhibit browning of fresh-cut produce. [ABSTRACT FROM AUTHOR]

Abstract: Catalytic synthesis of ethylbenzene by alkylation of benzene with diethyl oxalate was carried out over HZSM-5 with Si/Al ratios from 50 to 250. The catalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), ammonia temperature-programmed desorption (NH3-TPD) and pyridine IR techniques. As revealed by the results of NH3-TPD and pyridine IR spectra, a significant decrease in acidic strength and the number of acidic sites is observed with increasing Si/Al ratio from 50 to 250. The benzene conversion and ethylbenzene selectivity increases obviously with increasing Si/Al ratio from 50 to 200. With a further increase in Si/Al ratios, a slight decrease in the conversion of benzene and selectivity for ethylbenzene is detected, indicating that a proper acidic strength was required in this reaction. In addition, the effects of temperature and feed ratio on the catalytic activity and product distributions are also investigated in this study. [Copyright &y& Elsevier]

Abstract: Selective synthesis of p-xylene by vapor phase alkylation of toluene with dimethyl carbonate, over MgO-modified MCM-22, was carried out to demonstrate the relationship between acidity and catalytic performance. Characterization results show that the number of Brønsted acid sites on MCM-22 decreased significantly after MgO modification, which resulted in a decrease in activity. Selectivity for p-xylene was improved greatly over MgO-modified MCM-22, which can be attributed to effective suppression of xylene isomerization by the reduction in external surface Brønsted acid sites. The additional Lewis acid sites generated after MgO modification had no apparent effect on the catalytic performance. [Copyright &y& Elsevier]

Abstract: A rapid and sensitive method based on microchip capillary electrophoresis with condition optimization of genetic algorithm-support vector regression (GA-SVR) was developed and applied to simultaneous analysis of multiplex PCR products of four foodborne pathogenic bacteria. Four pairs of oligonucleotide primers were designed to exclusively amplify the targeted gene of Vibrio parahemolyticus, Salmonella, Escherichia coli (E. coli) O157:H7, Shigella and the quadruplex PCR parameters were optimized. At the same time, GA-SVR was employed to optimize the separation conditions of DNA fragments in microchip capillary electrophoresis. The proposed method was applied to simultaneously detect the multiplex PCR products of four foodborne pathogenic bacteria under the optimal conditions within 8min. The levels of detection were as low as 1.2×102 CFUmL−1 of Vibrio parahemolyticus, 2.9×102 CFUmL−1 of Salmonella, 8.7×101 CFUmL−1 of E. coli O157:H7 and 5.2×101 CFUmL−1 of Shigella, respectively. The relative standard deviation of migration time was in the range of 0.74–2.09%. The results demonstrated that the good resolution and less analytical time were achieved due to the application of the multivariate strategy. This study offers an efficient alternative to routine foodborne pathogenic bacteria detection in a fast, reliable, and sensitive way. [Copyright &y& Elsevier]

Abstract: The catalytic activity of a series of M(=Ni, Co, Cu)/(CeO2) x –(MgO)1 − x catalysts for methane combustion was investigated. (CeO2) x –(MgO)1 − x supports were prepared by a sol-gel method. The influence of CeO2 content and active components such as Ni, Co and Cu are discussed. The results indicate that the activity of the catalysts depends strongly on CeO2 content. The Ni/(CeO2)0.1 −(MgO)0.9 catalyst showed the highest catalytic activity and good thermal stability for methane combustion. The highly dispersed NiO is the main active site for methane combustion. Fresh M (Ni, Co and Cu)/(CeO2)0.1–(MgO)0.9 catalysts showed that the activity of CuO for methane combustion was slightly higher than that of NiO and CoO, while the thermal stability increased in the order Cu

Abstract: Acidity adjustment of MCM-22 was carried out by hydrothermal treatment of parent MCM-22 with flowing pure steam at high temperature. XRD, SEM and N2 adsorption/desorption results indicated that the crystallinity and pore properties of MCM-22 were affected slightly by hydrothermal treatment at different temperatures. NH3-TPD and FT-IR with pyridine adsorption showed only a slight decrease in Brønsted acid sites, compared with parent MCM-22, with hydrothermal treatment temperature in the range 773–873K. The strength of Brønsted acid sites was reduced severely at hydrothermal treatment temperatures of 973 and 1073K. The Lewis acid sites were only slightly affected by hydrothermal treatment. A substantial improvement in ethylbenzene selectivity along with a slight decrease in benzene conversion was achieved in catalytic synthesis of ethylbenzene by alkylation of benzene with diethyl carbonate over MCM-22 hydrothermally treated at 873K. A sharp decrease in benzene conversion was detected over MCM-22 hydrothermally treated at 973K. The results indicate that alkylation of benzene with diethyl carbonate occurred mainly on Brønsted acid sites, and the effect of Lewis acid sites on the alkylation process is negligible. Reduction of Brønsted acid sites of the catalyst can suppress side reactions and improve selectivity for ethylbenzene. It was found that a particular acid strength of catalyst was required to maintain high benzene conversion and ethylbenzene selectivity. [Copyright &y& Elsevier]

Abstract: The catalytic synthesis of ethylbenzene by alkylation of benzene with diethyl carbonate was carried out over HZSM-5 with Si/Al ratios from 50 to 250. The catalysts were characterized by XRD, SEM, 29Si and 27Al MAS-NMR, NH3-TPD and pyridine IR techniques. HZSM-5 with a Si/Al ratio of 200 exhibited the best benzene conversion and ethylbenzene selectivity because of its ideal acid strength. Strongly acidic sites may lead to an excessive decomposition of diethyl carbonate. The effects of temperature, feed ratio, WHSV and time-on-stream on catalytic activity and product selectivity were studied, and a possible mechanism is presented. [Copyright &y& Elsevier]

This paper reports the size-exclusion properties of nanoporous films derived from polystyrene-poly(methylmethacrylate) diblock copolymers (PS-b-PMMA) for biomacro-molecules. These properties were assessed by measuring cyclic voltammetry of ferritin (12 nm in diameter) adsorbed onto recessed nanodisk-array gold electrodes (RNEs) fabricated from the nanoporous films having different effective pore diameters and surface functionalities. RNEs having 20-nm-diameter nanopores modified with a poly(ethylene glycol) (PEG) layer showed the redox currents of ferritin after their immersion in a ferritin solution (5 mg/mL) for longer than 2 h. The currents originated from the direct electron transfer reaction of ferritin molecules immobilized on the underlying gold surface as a result of their penetration through the 20-nm-diameter nanopores. The PEG modification of the nanopore surface was required for the penetration of ferritin, probably because it reduced the nonspecific adsorption of ferritin to the nanopore surface. In contrast, no redox current of ferritin was observed for RNEs having PEG-modified 15-nm-diameter nanopores after their immersion in the ferritin solution for 12 h, indicating the size-exclusion of ferritin from the 15-nm nanopores. The distinct size-exclusion properties of the PS-b-PMMA-derived nanoporous films reflect their uniform diameters and shapes and will provide a means for fabricating separation membranes for biomolecules with high size-based selectivity. [ABSTRACT FROM AUTHOR]

An electrochemical biosensor was fabricated by covalent modification of 5-hydroxytryptophan (5-HTP) on the surface of glassy carbon electrode (GCE). The electrode, denoted as 5-HTP/GCE, was characterized by X-ray photoelectron spectroscopy, cyclic voltammetry and differential pulse voltammetry. For comparison, tryptophan modified GCE (TRP/GCE) and serotonin modified GCE (5-HT/GCE) were prepared by the same method. It was found that electrocatalytic ability of these electrodes was in the order of 5-HTP/GCE > TRP/GCE > 5-HT/GCE for the oxidation of dopamine (DA) and 5-HT. The sensor was effective to simultaneously determine DA and 5-HT in a mixture. It can resolve the overlapping anodic peaks into two well-defined voltammetric peaks at 0.24 and 0.39 V (versus SCE). The linear response is in the range of 5.0 × 10−7–3.5 × 10−5 mol L−1 with a detection limit of 3.1 × 10−7 mol L−1 for DA, and in the range of 5.0 × 10−6–3.5 × 10−5 mol L−1 with a detection limit of 1.7 × 10−6 mol L−1 for 5-HT ( s/ n = 3), respectively. [ABSTRACT FROM AUTHOR]

Secondary phosphirane complexes isomerize above 100 °C to give the corresponding terminal phosphinidene complexes, which can be trapped by alkenes and alkynes. This reaction is a rare instance of the isomerization of a PIII derivative into a PI derivative. It appears to mimic the reductive elimination of alkanes from transition-alkylmetal hydrides. [ABSTRACT FROM AUTHOR]

Secondary phosphirane complexes isomerize above 100 °C to give the corresponding terminal phosphinidene complexes, which can be trapped by alkenes and alkynes. This reaction is a rare instance of the isomerization of a PIII derivative into a PI derivative. It appears to mimic the reductive elimination of alkanes from transition-alkylmetal hydrides. [ABSTRACT FROM AUTHOR]

Abstract: Single-stranded deoxyribonucleic acid (ssDNA)-wrapped single-walled carbon nanotubes (SWNTs) were modified on the surface of glassy carbon electrode (GCE) by covalent modification technique. Field emission scanning electron microscope (FE-SEM), X-ray photoelectron spectrum (XPS), electrochemical impedance spectroscopy (EIS), and cyclic voltammetric (CV) were used to characterize the properties of this modified electrode. The results showed that SWNTs–ssDNA composites were successfully immobilized onto the surface of GCE. Moreover, this modified electrode exhibited high stability, largely active areas, and efficiently electrocatalytic activities. It had been used for the analysis of various biomolecules, such as dopamine (DA), uric acid (UA), and ascorbic acid (AA), and the results were satisfactory. [Copyright &y& Elsevier]

Abstract: A promising electrochemical sensor was fabricated by electrodeposition of gold nanoparticles on poly(3-methylthiophene) (P3MT)-modified glassy carbon electrode (GCE), forming a nano-Au/P3MT composites-modified GCE (nano-Au/P3MT/GCE). Field emission scanning electron microscope (FE-SEM) and electrochemical techniques were used for the characterization of these composites. It was found that nano-Au/P3MT layer was very uniform, and formed a kind of nanoporous structure. Electrochemical experiments showed that this proposed nano-Au/P3MT composites-modified electrode exhibited excellent electrocatalytic properties for nitrite and iodate. Amperometry revealed that there existed a good linear relationship between peak current with the concentration in the range of 10–1000μM and the detection limit of 2.3μM for nitrite and in the range of 5–500μM and the detection limit of 1.4μM for iodate. The proposed method has been used as an amperometric detector for analysis of nitrite and iodate in iodized table salt and results were satisfactory. The nano-Au/P3MT composites-modified electrode had good storage stability, reproducibility and anti-interference ability for promising practical application. [Copyright &y& Elsevier]

Mercury is an anthropogenic toxic heavy metal found in the environment. It is highly desirable to develop a fluorescence probe that can selectively and sensitively detect mercury ions using a turn-on response. This paper reports the successful development of a peptide fluorescence probe, TP-2 (TPE-Trp-Pro-Gln-His-Glu-NH 2), which uses aggregation-induced emission effects and high selectivity to detect Hg2+. After fluorescence was activated, Hg2+ was efficiently detected using the change in fluorescence intensity. The detection limit for Hg2+ in the buffer solution was 41 nM (R2 = 0.9952). Owing to its high sensitivity, high cell permeability, and low biotoxicity, the probe could perform live cell imaging under biological conditions. This study demonstrated that TP-2 can detect Hg2+ in complex biological environments. [Display omitted] • The peptide fluorescence probe based on AIE can obtain 30-fold fluorescence enhancement. • Highly selective response to Hg2+ among various biological relevant metal ions. • The side chains of Trp, Gln, His, and Glu are used as Hg2+ coordination sites, making the probe highly specific. • This probe can be used for detecting and imaging Hg2+ in live cells. [ABSTRACT FROM AUTHOR]

• Aptamers which can specificity bind to 25(OH)D 3 have been applied to establish new electrochemical biosensor. • The binding abilities of 25(OH)D 3 aptamers were confirmed and compared by spectroscopic and electrochemical methods. • The developed aptasensor showed high specificity and sensitivity towards 25(OH)D 3. Vitamin D deficiency remains a serious health issue in many developing countries and regions with a deficiency of sunlight. And although the demand for vitamin D testing has increased dramatically in recent years, finding new methods for efficient rapid testing remain at the forefront for clinical diagnosis and public health prevention. Herein, we are introducing an electrochemical aptasensor for the detection of 25-hydroxyvitamin D 3 (25(OH)D 3), comparing two aptamers platforms. The oligonucleotide aptamers were immobilized on gold surfaces using a disulfide linker, followed by monitoring the electrochemical response by cyclic voltammetry (CV), square wave voltammetry (SWV), and electrochemical impedance spectroscopy (EIS). Our studies revealed that the aptamer VDBA14 possessing a 5′-terminal disulfide recognizes the vitamin target. This electrochemical aptasensor exhibited a wide linear range of 1–1000 nM and a limit of detection (LOD) of 0.085 nM for the detection of 25(OH)D 3. The aptasensor also allows the detection of 25(OH)D 3 in human serum sample with high sensitivity and selectivity, indicating that the proposed electrochemical aptasensor may have potential applications in clinical diagnosis. [ABSTRACT FROM AUTHOR]

Abstract: The catalytic behavior of the mesoporous sieve supported potassium nitrate KNO3/MCM-48 for the synthesis of dipropyl carbonates (DPC) by transesterification of dimethyl carbonate (DMC) with propanol was investigated. The catalysts were characterized by the techniques of X-ray diffraction (XRD), CO2 temperature-programmed desorption (CO2-TPD), FT-IR spectroscopy, N2 adsorption and X-ray fluorescence (XRF). The XRD results indicated that the structure of MCM-48 was gradually deformed with the increase in the KNO3 loading, whereas the framework of MCM-48 was basically retained until the loading of KNO3 was over 18%. IR spectra showed that KNO3 was gradually decomposed with increasing calcination temperature. The CO2-TPD showed two new types of basic site were generated, which have higher catalytic ability for the synthesis of DPC. Effects of the loading amount of active components, the calcinatory temperature, the catalyst dosage and the reaction conditions on the catalytic activity were investigated in detail and the optimized reaction conditions were acquired. [Copyright &y& Elsevier]

Abstract: Four new triorganotin complexes of 3-amino-5-mercapto-1,2,4-triazole with the type of R3Sn(SC2N3HNH2-3) (R=Me, 1; n-Bu, 2; Ph, 3; PhCH2, 4) have been synthesized. All the complexes have been characterized by elemental analysis, IR, 1H NMR and 13C NMR spectra. Complexes 1, 3 and 4 have been characterized by X-ray crystallography analyses too. The geometry about Sn of complex 1 is distorted trigonal bipyramidal and the supramolecular structures of complex 1 has been found consist of channels built up by intermolecular N–H⋯N hydrogen bonding. The geometry of tin atoms in complexes 3 and 4 are distorted tetrahedron and 1D polymers connected by intermolecular N–H⋯N hydrogen bonding or N–H⋯N and N–H⋯S hydrogen bonding. Additionally, 1D polymer of complex 3 aggregated in 2D layer by intermolecular N–H⋯S hydrogen bonding. [Copyright &y& Elsevier]

Abstract: A novel electrochemical sensor has been constructed by use of a glassy carbon electrode (GCE) coated with a gold nanoparticle/choline (GNP/Ch). Electrochemical impedance spectroscopy (EIS), field emission scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS) were used to characterize the properties of this modified electrode. It was demonstrated that choline was covalently bounded on the surface of glassy carbon electrode, and deposited gold nanoparticles with average size of about 100nm uniformly distributed on the surface of Ch. Moreover, the modified electrode exhibits strong electrochemical catalytic activity toward the oxidation of dopamine (DA), ascorbic acid (AA) and uric acid (UA) with obviously reduction of overpotentials. For the ternary mixture containing DA, AA and UA, these three compounds can be well separated from each other, allowing simultaneously determination of DA and UA under coexistence of AA. The proposed method can be applied to detect DA and UA in real samples with satisfactory results. [Copyright &y& Elsevier]

Abstract: In this paper, the films of overoxidized polypyrrole (PPyox) directed single-walled carbon nanotubes (SWNTs) have been electrochemically coated onto glassy carbon electrode (GCE). Electroactive monomer pyrrole was added into the solution containing sodium dodecyl sulfate (SDS) and SWNTs. Then, electropolymerization was proceeded at the surface of GCE, and a novel kind of conducting polymer/carbon nanotubes (CNTs) composite film with the orientation of CNTs were obtained correspondingly. Finally, this obtained polypyrrole (PPy)/SWNTs film modified GCE was oxidized at a potential of +1.8V. It can be found that this proposed PPyox/SWNTs composite film modified GCE exhibited excellent electrocatalytic properties for some species such as nitrite, ascorbic acid (AA), dopamine (DA) and uric acid (UA), and could be used as a new sensor for practical applications. Compared with previous CNTs modified electrodes, SWNTs were oriented towards the outside of modified layer by PPyox and SDS, which made the film easily conductive. Moreover, this proposed film modified electrode was more stable, selective and applicable. [Copyright &y& Elsevier]

Abstract: 5-Hydroxytryptophan (5-HTP) was covalently grafted on the surface of glassy carbon electrodes (GCEs) using cyclic voltammetric method in a phosphate buffer solution. The prepared electrode, denoded as 5-HTP/GCE, was characterized by X-ray photoelectron spectroscopy, cyclic voltammetry and differential pulse voltammetry (DPV). Tryptophan grafted GCE (TRP/GCE) and 5-hydroxytryptamine grafted GCE (5-HTP/GCE) were also prepared by the same method for comparison. It was found that the electrocatalytic activities toward the oxidation of uric acid (UA) and ascorbic acid (AA) was in the order of 5-HT/GCE>5-HTP/GCE>TRP/GCE for UA oxidation and 5-HT/GCE=5-HTP/GCE>TRP/GCE for AA oxidation. However, the CV current sensitivity was estimated as 4:2:1 for 5-HTP/GCE:5-HT/GCE:TRP/GCE. The DPV peaks for UA and AA oxidation appeared at 0.07V and 0.34V versus SCE, respectively, allowing simultaneous determination in mixtures. A linearly response in the range of: 5.0×10−7 to 1.1×10−5 M with the detection limit (s/n =3) of 2.8×10−7 M for UA determination, and a linear response in the range of: 5.0×10−6 to 1.0×10−4 M with the detection limit of 4.2×10−6 M for AA determination were obtained. This electrode was used for UA and AA determinations in human urine samples satisfactorily. [Copyright &y& Elsevier]

Abstract: On the top of a multi-walled carbon nanotubes (MWNTs) modified glassy carbon electrode (MWNTs/GCE), Pt nanoclusters were electrochemically deposited, fabricating a Pt/MWNTs composite modified electrode, Pt/MWNTs/GCE. X-ray photoelectron spectroscopy, powder X-ray diffraction and field emission scanning electron microscope were used for the surface characterization of the electrode, and demonstrated the formation and distribution of Pt clusters of Pt nanoparticles of 8.4nm in averaged size in the MWNTs matrix. The preliminary study found that this composite modified electrode has strong electrocatalytic activity toward the oxidation of estrogens involving estradiol, estrone and estriol. The voltammetric behavior of estrogens on this electrode was investigated by cyclic voltammetry, linear sweep voltammetry and square-wave voltammetry. In comparison with the MWNTs/GCE or a Pt nanoparticles modified GCE prepared in the similar way, this composite modified electrode exhibited much higher current sensitivity and catalytic activity. This electrode is also stable. The linear range of square-wave voltammetric determination was 5.0×10−7–1.5×10−5 mol/L for estradiol, 2.0×10−6–5.0×10−5 mol/L for estrone, and 1.0×10−6–7.5×10−5 mol/L for estriol. Under an assumption that the concentration ratio of estradiol:estrone:estriol is 2:2:1, the real sample of blood serums was tested for the determination using this electrode. Satisfactory result was obtained with averaged recovery of 105%. [Copyright &y& Elsevier]

Abstract: A novel covalently modified glassy carbon electrode (GCE) with poly (vinyl alcohol) (PVA) has been fabricated through an electrochemical oxidation procedure and was used to electrochemically detect dopamine (DA), ascorbic acid (AA), uric acid (UA) and their mixture by a differential pulse voltammetry (DPV) method. The modified GCE exhibits potent and persistent electron-mediating behavior followed by well-separated oxidation peaks in cyclic voltammetry (CV) or DPV towards DA, AA and UA with activation overpotentials. For the ternary mixture containing DA, AA and UA, the three compounds can well be separated from each other at a scan rate of 0.50Vs−1 with a potential difference of 140mV, 140mV and 280mV in CV, and 180mV, 130mV and 310mV in DPV between DA and AA, DA and UA, and UA and AA, respectively. The differences are large enough to determine AA, DA and UA individually and simultaneously. The stability of the PVA covalently modified GCE is good up to at least 30 days of continual operation. [Copyright &y& Elsevier]

Abstract: A series of organotin (IV) complexes with 6-amino-1,3,5-triazine-2,4-dithiol of the type [(R n SnCl4−n )2 (C3H2N4S2)] (n =3: R=Me 1, n-Bu 2, PhCH2 3, Ph 4; n =2: R=Me 5, n-Bu 6, PhCH2 7, Ph 8) have been synthesized. All the complexes 1–8 have been characterized by elemental analysis, IR, 1H and 13C NMR spectra. Among them complexes 1, 4, 5 and 8 have also been characterized by X-ray crystallography diffraction analyses, which revealed that the tin atoms of complexes 1, 4, 5 and 8 are all five-coordinated with distorted trigonal bipyramid geometries. [Copyright &y& Elsevier]

Based on the strong enhancement effect of proteins on the resonance light scattering of copper phthalocyanine tetrasulfonic acid, a method for the determination of microamounts of proteins has been developed. Under the experimental conditions (2.0×10 -6 mol/L copper phthalocyanine tetrasulfonic acid, pH 2.60, ionic strength 0.001 mol/L NaCl), the linear range of this assay is 0.06–4.0 µg/mL for bovine serum albumin (BSA), 0.1–2.0 µg/mL for human serum albumin (HSA), 0.0–2.0 µg/mL for human γ‐IgG, and 0.2–6.0 µg/mL for ovalbumin. The detection limits (3δ) are 16.8 ng/mL for BSA, 23.4 ng/mL for HSA, 37.6 ng/mL for human γ‐IgG, and 48.3 ng/mL for ovalbumin, respectively. This method has been applied to the analysis of total proteins in human serum samples collected from the hospital, and the results were in good agreement with those reported by the hospital. [ABSTRACT FROM AUTHOR]

Cysteine-capped ZnS nanometer-sized fluorescent particles were produced by a colloidal aqueous synthesis. The functionalized nanoparticles are water-soluble and suitable for biological application. A synchronous fluorescence method has been developed for the rapid determination of DNA with functionalized nano-ZnS as a fluorescence probe, based on the synchronous fluorescence enhancement of cysteine-capped nano-ZnS in the presence of DNA. When Δλ=190 nm, maximum synchronous fluorescence is produced at 267 nm at pH 5.12. Under optimum conditions, the synchronous fluorescence intensity is proportional to the concentration of nucleic acids in the range 0.1–1.2 μg ml-1 for calf thymus DNA, 0.1–0.6 μg ml-1 for fish sperm DNA. The corresponding detection limit is 32.9 ng ml-1 for calf thymus DNA and 24.6 ng ml-1 for fish sperm DNA. This method is simple, inexpensive, rapid and sensitive. The recovery and relative standard deviation are satisfactory. [Copyright &y& Elsevier]

The manganese-tetrasulfonatophthalo-cyanine (MnTSPc) catalyzed luminol-hydrogen peroxide chemiluminescence (CL) system can be quenched in the presence of nucleic acids. A new and highly sensitive CL quenching method for determining nucleic acids in aqueous solutions has been developed. Under optimum conditions, linear relationships were found between the quenched intensity of CL and the concentration of nucleic acids in the range 0.10–2.0 µg mL-1 for calf thymus DNA and 0–1.6 µg mL-1 for fish sperm DNA. The limits of detection were 14.8 ng mL-1 for calf thymus DNA and 21.7 ng mL-1 for fish sperm DNA. The relative standard deviation (RSD) of nine replicate measurements is 1.4% for 1.0 µg mL-1 calf thymus DNA. The method was applied to the analysis of nucleic acids in synthetic samples and the results are satisfactory. [ABSTRACT FROM AUTHOR]

A rapid flow-injection method with chemiluminescence (CL) detection is described for the determination of glutathione (GSH). The method is based on the CL reaction of luminol and hydrogen peroxide. GSH can greatly enhance the chemiluminescence intensity in 0.1 mol/L borax–sodium hydroxide buffer solution (pH = 9.7). The maximum CL intensity was directly proportional to the concentration of GSH in the range 3.0 × 10-7–2.0 × 10-5 mol/L, and the detection limit was 6.8 × 10-8 mol/L. The relative standard deviation was 3.4% for 5.0 × 10-6 mol/L of GSH (n = 11). [ABSTRACT FROM AUTHOR]

A new promising mimetic peroxidase, manganese-tetrasulfonatophthalocyanine (MnTSPc) has been synthesized and applied to the determination of hydrogen peroxide based on its catalytic effect on the chemiluminescence reaction between luminol and hydrogen peroxide. Under optimum conditions, the calibration graph has a linear range of 4.0 × l0[SUP-8] 2.0 × 10[SUP-5]mol/1 hydrogen peroxide, the detection limit of the method is 6.8 × 10[SUP-9]mol/l. At a hydrogen peroxide concentration of 1.0 × 10[SUP-6]mol/l, the relative standard deviation is 2.4% (n = 10). [ABSTRACT FROM AUTHOR]

A novel fluorescence turn-on strategy for glucose sensing is demonstrated. The fluorescence of a perylene probe could be quenched by the silver nanoparticles (Ag NPs). The Ag NPs could be etched by H2O2 generated from the enzymatic oxidation of glucose. And efficient probe fluorescence recovery was detected. [ABSTRACT FROM AUTHOR]