We fabricated an electrochemical molecularly imprinted polymer (MIP) chemosensor for rapid identification and quantification of E. coli strain using 2-aminophenyl boronic acid as the functional ...monomer. This strain is a modified Gram-negative strain of Escherichia coli bacterium, an ordinary human gut component. The E. coli strongly interacts with a boronic acid because of porous and flexible polymers of the cell wall. The SEM imaging showed that the bacteria template was partially entrapped within the polymeric matrix in a single step. Moreover, this imaging confirmed E. coli K-12 cell template extraction effectiveness. The prepared MIP determined the E. coli K-12 strain up to 2.9 × 104 cells mL−1. The interference study performed in the presence of E. coli variants expressing different surface appendages (type 1 fimbriae or Antigen 43 protein) or Shewanella oneidensis MR1, another Gram-negative bacteria, demonstrated that the bacterial surface composition notably impacts sensing properties of the bacteria imprinted polymer.
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•E. coli E2152 was successfully imprinted in a polymer by 2-aminophenylboronic acid and aniline co-electropolymerization.•The bacteria template was entrapped in the resulting molecularly imprinted polymer in a single step.•Thus prepared MIP film-based electrochemical chemosensor determined E. coli E2152 up to 2.9 × 104 cells/mL.•E. coli E2152 determination was selective versus bacteria of other surface properties.
Biocompatible polyacrylamide gel and core–shell nanoparticles (NPs) were synthesized using a one-step electrochemically initiated gelation. Constant-potential electrochemical decomposing of ammonium ...persulfate initiated the copolymerization of N-isopropyl acrylamide, methacrylic acid, and N,N′-methylenebisacrylamide monomers. This decomposing potential and monomers’ concentrations were optimized to prepare gel NPs and thin gel film-grafted core–shell NPs. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) imaging confirmed the gel NP formation. The lyophilized gel NPs and core–shell NPs were applied to support the three-dimensional (3D) cell culture. In all, core–shell NPs provided superior support for complex 3D tissue structures.
The present review summarizes the molecular imprinting approach to bacteria electrochemical sensing developed over the last five years. Designing artificial molecularly imprinted polymer (MIP) and ...aptamer receptors for bacteria sensing is more challenging than for analytes of small and even large molecules like proteins. This herein-considered challenge arises from the bacteria's large size and numerous functional groups in bacteria cell walls for which selective complementary recognizing sites imprinted in a polymer are puzzling to generate. Moreover, the morphological characterization and recognition mechanism of the MIPs is discussed here in detail.
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In this work nickel modified polymer composites have been synthesized electrochemically for methanol electrooxidation on platinum and graphite electrodes. Ni (II) ions were incorporated on ...polyaniline and poly (o-aminophenol)(PANI/POAP) bilayer structure from 0.1M Nickel sulphate hexahydrate solution at open circuit potential (OCP).TheNi (II) deposited composites were characterized with Fourier Transform Infrared (FTIR) spectroscopy, Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS). Cyclic voltammetry characterization exhibits stable redox pair of Ni+3/Ni+2 for both electrodes. Fourier transform infrared spectroscopy was used for functional group analysis. Ni (II) peaks were observed in the region of 400–700cm−1 along with peaks at 1102cm−1 and 1400–1600cm−1 for polyaniline and phenoxazine units. The Ni-polymer composite on platinum and graphite electrode followed different phenomenon for methanol electroxidation in alkaline media. The cyclic voltammetry results showed significantly large methanol oxidation on platinum substrate with charge storage capacity of 196μ F/cm2 for 1.5M methanol in alkaline media as compared to 8.306μF/cm2 of graphite. The diffusion controlled linear response for increase rate of methanol concentration has been obtained for Ni (II)/PANI/POAP-Pt. The electrochemical impedance spectroscopy (EIS)results indicated increase in charge storage capacity from 10−4F/cm2 to 10−3F/cm2 with increasing potentials at lower frequency region.The phase shift was observed from 60–40degrees for increased potentials at low frequency range in EIS analysis. The increased conductive behavior from 10−5 to 10−2s/cm2 has been obtained fornickel modified polymer composite at higher frequency region in EIS analysis.
•Electrodeposition of Polyaniline/Poly(o-aminophenol) bilayered structure on platinum and graphite substrates for methanol oxidation.•PANI/POAP-Gra electrode showed less reactivity and stability ...towards methanol oxidation.•PANI/POAP-Pt electrode exhibited superior performance with high methanol oxidation current, capacitance and specific capacitance.•The dielectric properties and AC conductivity of the PANI/POAP-Pt electrode with respect to the applied potential were evaluated.
Polyaniline/Poly(o-aminophenol) (PANI/POAP) bilayered films were deposited by electro polymerization on platinum (Pt) and graphite (Gra) electrodes for methanol oxidation in direct methanol fuel cells. The chemical composition of bilayered structure was characterized by Fourier transform infrared (FTIR) spectroscopy. Results demonstrated the presence of FTIR peaks associated to PANI and POAP constituents confirming the bonding of PANI and POAP in the bilayered composite structure. The electrochemical properties of PANI/POAP electrodes were examined in pure and sulfuric acid mixed methanol solutions using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). PANI/POAP-Gra electrode showed less reactivity towards methanol oxidation, as well as poor stability upon repeated cycling. On the other hand, PANI/POAP-Pt electrode exhibited superior performance with high methanol oxidation current (Ia), capacitance (C), and specific capacitance (Cs). In addition, PANI-POAP-Pt electrode was found better than PANI-POAP-Gra electrode in terms of operation stability based on continuous cycling in methanol up to 100 cycles. The dielectric properties and AC conductivity (σac) of the PANI/POAP-Pt electrode with respect to the applied potential have been discussed.
Herein, we developed a simple procedure for synthesizing micrometer-sized microgel particles as a suspension in an aqueous solution and thin films deposited as shells on different inorganic cores. A ...sufficiently high constant potential was applied to the working electrode to commence the initiator decomposition that resulted in gelation. Under hydrodynamic conditions, this initiation allowed preparing different morphology microgels at room temperature. Importantly, neither heating nor UV-light illumination was needed to initiate the polymerization. Moreover, thin films of the cross-linked gel were anchored on different core substrates, including silica and magnetic nanoparticles. Scanning electron microscopy and transmission electron microscopy imaging confirmed the microgel particles’ and films’ irregular shape and porous structure. Energy-dispersive X-ray spectroscopy indicated that the core coating with the microgel film was successful. Dynamic light scattering measured the micrometer size of gel particles with different combinations of acrylic monomers. Thermogravimetric analysis and the first-derivative thermogravimetric analysis revealed that the microgels’ thermal stability of different compositions was different. Fourier-transform infrared and 13C NMR spectroscopy showed successful copolymerization of the main, functional, and cross-linking monomers.
Hepatocellular carcinoma is one of the major health problems throughout the world with a very poor prognosis. MicroRNAs are small regulatory non-protein-coding RNA molecules. We aimed at ...investigating microRNA-199 as a potential therapeutic tool for HCC both in vitro and in an experimental model. A therapeutic strategy based on the effect of microRNAs to target genes responsible for liver cancer was adopted in this work. The ability of these small RNAs to potently influence cellular behavior was also investigated. The role of miR-199a in the development of liver cancer has been identified using a systematic literature search using miRBase. HepG2 cell line was used to test the effect of miRNA199a in vitro. Hepatocellular carcinoma was induced in Male Balb/C mice by diethylnitrosamine (DEN). Mice were treated with miRNA-199a and sacrificed after 16 weeks and blood samples and liver specimens were collected for biochemical and histopathological assessment. Histopathological examination of liver specimens after miRNA 199a treatment showed regression of Hepatocellular carcinoma with restoration of normal architecture. AFP, VEGF and TNFα levels decreased after treatment with miRNA 199a. Caspase 3 and 9; showed decreased expression in animals treated with miRNA 199a than non-treated ones.
The main aim of this study was to investigate the effect of playing venue for pre-competition cortisol and state anxiety in university male basketball players. Ninety six players from public and ...private universities of Lahore have evaluated during eight competitive matches played at home (n=4) and away (n=4) venues. Blood samples were collected to analyze the cortisol concentrations by the ELISA assay and state anxiety was assessed using the CSAI-2 questionnaire. All the data collection took place before the pre-match warm-up. Data was analyzed by using paired sample t test. Results showed that cortisol was significantly (p-0.002) elevated on away ground, whereas, somatic state anxiety was markedly (p-0.001) increased on an opponents home ground. In conclusion, it is suggested that playing venue affects cortisol response and anxiety score values on away ground that results in psychological interventions for players to deal with all threats and stressful stimuli of playing venue factors affecting the players performance on an opponents home ground.
Angiomyofibroblastoma of the vulva Ibnerasa, Shazia N; Yasmeen, Fauzia; Shami, Nabila
Journal of the College of Physicians and Surgeons--Pakistan
22, Številka:
2
Journal Article
Recenzirano
A 30-year-old female presented with unilateral labial enlargement. The clinical impression was that of a benign cyst. The microscopic features were that of angiomyofibroblastoma showing hyper and ...hypocellular areas containing spindle and plump stromal cells admixed with blood vessels. This tumour is benign with extremely low rate of recurrence. Surgery is the only treatment as in this case.
The home advantage is a powerful wonder that happens in the realm of amateur and professional games where most teams win more than 50% of matches. The present study compared the effects of playing ...venue on hormonal responses and psychological state of inter-university volleyball players at home and away ground. A total of 96 male players age, 18 to 24 years from eight different public and private universities were selected as the subject in this study. Matches were scheduled in such a manner so that each team would play one match on home ground and one on away ground. The results of this study showed that a 13% reduction in the testosterone level of players was seen on the opponent’s home ground before playing the match, whereas, 18% elevation in cortisol level of players was recorded on the opponent’s home ground before-match. Psychological measures indicated that players’ cognitive and somatic anxiety levels were increased on away ground (10% and 13%, respectively) whereas, their self-confidence level declined by 17% on an opponent’s home ground before the commencement of the match. The present study supports the notion that there are differences in pre-competition hormonal and psychological states that may play a key role in ‘the home advantage’ which could affect players’ behavior and match outcomes.
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