Dimensionality engineering of flower-like bimetallic nanozyme with high peroxidase-activity for naked-eye and on-site detection of acrylamide in thermally processed foodsOA

Acrylamide（AA） is a neurotoxin and carcinogen that formed during the thermal food processing. Conventional quantification techniques are difficult to realize on-site detection of AA. Herein, a flower-like bimetallic FeCu nanozyme（FeCuzyme） sensor and portable platform were developed for naked-eye and on-site detection of AA.The FeCuzyme was successfully prepared and exhibited flower-like structure with 3D catalytic centers. Fe/Cu atoms were considered as active center and ligand frameworks were used as cofactor, resulting in collaborative substrate-binding features and remarkably peroxidase-like activity. During the catalytic process, the 3,3',5,5'-tetrame-thylbenzidine（TMB） oxidation can be quenched by glutathione（GSH）, and then restored after thiolene Michael addition reaction between GSH and AA. Given the “on–off–on” effect for TMB oxidation and high PODlike activity, FeCuzyme sensor exhibited a wide linear relationship from 0.50 to 18.00 μM（R²= 0.9987） and high sensitivity（LOD = 0.2360 μM） with high stability. The practical application of FeCuzyme sensor was successfully validated by HPLC method. Furthermore, a FeCuzyme portable platform was designed with smartphone/laptop,and which can be used for naked-eye and on-site quantitative determination of AA in real food samples. This research provides a way for rational design of a novel nanozyme-based sensing platform for AA detection.     

Chemistry of single-walled carbon nanotubes

In this Account we highlight the experimental evidence in favor of our view that carbon nanotubes should be considered as a new macromolecular form of carbon with unique properties and with great potential for practical applications. We show that carbon nanotubes may take on properties that are normally associated with molecular species, such as solubility in organic solvents, solution-based chemical transformations, chromatography, and spectroscopy. It is already clear that the nascent field of nanotube chemistry will rival that of the fullerenes.     

Preliminary investigations into the loco-man factor on the Indian railways

After a brief consideration of the existing literature pertaining to the ergonomic analysis and design of locomotive drivers' cabins, the present paper describes the results of a questionnaire survey among 26 electric locomotive drivers in India, with some recommendations. A preliminary analysis of the controls and displays in the cabin has been presented.     

Dual desorption electrospray ionization-laser desorption ionization mass spectrometry on a common nanoporous alumina platform for enhanced shotgun proteomic analysis

A gold coated nanoporous alumina surface was used for dual ionization mode mass spectrometric analysis using desorption electrospray ionization (DESI) and laser desorption ionization (LDI). DESI and LDI mass spectrometry (MS) from the nanoporous alumina surface were compared with conventional electrospray ionization (ESI) mass spectrometry and matrix assisted laser desorption ionization (MALDI) for analysis of tryptic digests of proteins. Combined use of DESI and LDI offer greater peptide coverage than either method alone and comparable peptide coverage as with dual MALDI and ESI. This dual ionization technique using a common platform with same sample spot demonstrates a potential time and cost-effective tool for improved shotgun proteomic analysis.     

Progress in rectifying-based RRAM passive crossbar array

Resistive random access memory(RRAM) with crossbar structure is receiving widespread attentions due to its simple structure,high density,and feasibility of three-dimensional(3D) stack.It is an extremely promising solution for high density storage.However,a major issue of crosstalk restricts its development and application.In this paper,we will first introduce the integration methods of RRAM device and the existing crosstalk phenomenon in passive crossbar array,and then focus on the 1D1R(one diode and one re...     

Note: emittance measurements of intense pulsed proton beam for different pulse length and repetition rate

The high intensity ion source (SILHI), in operation at CEA-Saclay, has been used to produce a 90 mA pulsed proton beam with pulse length and repetition rates suitable for the European Spallation Source (ESS) linac. Typical r-r(') rms normalized emittance values smaller than 0.2π mm mrad have been measured for operation in pulsed mode (0.01 < duty cycle < 0.15 and 1 ms < pulse duration < 10 ms) that are relevant for the design update of the Linac to be used at the ESS in Lund.     

Prediction-based protein engineering of domain I of Cry2A entomocidal toxin of Bacillus thuringiensis for the enhancement of toxicity against lepidopteran insects

Issues relating to sustenance of the usefulness of genetically modified first generation Bt crop plants in the farmer's field are of great concern for crop scientists. Additional biotechnological strategies need to be in place to safeguard the possibility for yield loss of Bt crop by other lepidopteran insects that are insensitive to the Cry1A toxin, and also against the possibility for emergence of resistant insects. In this respect, Cry2A toxin has figured as a prospective candidate to be the second toxin to offer the required protection along with Cry1A. In the present study, the entomocidal potency of Cry2A toxin was enhanced through knowledge-based protein engineering of the toxin molecule. Deletion of 42 amino acid residues from the N-terminal end of the peptide followed by the replacement of Lys residues by nonpolar amino acids in the putative transmembrane region including the introduction of Pro resulted in a 4.1-6.6-fold increase in the toxicity of the peptide against three major lepidopteran insect pests of crop plants.