Inorganic elemental compositions of commercial multivitamin/mineral dietary supplements: Application of collision/reaction cell inductively coupled-mass spectroscopy

Thirty five different commercially available multivitamin/mineral (MVM) dietary supplements in tablet, capsule, liquid or powder form for children, women, men, young and adult consumption were analysed by collision/reaction cell ICP-MS for their inorganic elemental compositions including Na, Mg, K, Ca, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Cd, Hg, and Pb. Samples were digested with concentrated nitric and hydrochloric acid (8:2) using a closed vessel microwave system. The validity of the applied method was assessed by the analysis of standard reference materials (SRM 3280, SRM 1566b) and of spiked samples. Special emphasis was given to the percentage deviation of calculated daily intake of each analysed element from their corresponding label claim. Additionally, for toxic elements calculated daily intake values are compared with those of the regulatory guideline values (e.g., recommended dietary allowance). The results revealed that all analysed products have calculated daily intake of As, Cd, Pb and Hg concentrations lower than those of the regulatory limits. The percentage differences between the calculated and claimed daily intake values varied moderately (20%) to significantly (>30%) for the potentially toxic elements, especially Cr, Se, Mn, and Zn. Furthermore, it is not uncommon for the same product to have high, as well as low, elemental compositions compared to their corresponding claimed values.     

Synthesis of nanocrystalline boron nitride by combustion process

Nanocrystalline boron nitride powders were synthesized by combustion process using urea as a fuel. Experiments were carried out by heating boric acid and urea in an N₂ atmosphere at 850°C. Boric acid was used as a source of boron while urea, as a source of nitrogen. The reactions were carried out in an autoclave with provisions for purging with nitrogen gas. The samples were characterized by powder X-ray diffraction, Fourier transform IR spectroscopy (FT-IR), FT-Raman spectroscopy, UV-VIS spectroscopy, and SEM. The article is published in the original.     

Properties of nanocomposite film combining hard TiN matrix with embedded fullerene-like WS2 nanoclusters

We have developed hard self-lubricant coatings combining a hard matrix (TiN) and a self-lubricant phase in the form of inorganic-like WS₂ fullerene. The nanoparticles were injected from the preparation chamber directly to the sample surface during reactive sputtering from a Ti target in Ar/N₂ atmosphere. The injection of the particles led to the local oxidation of the matrix due to the flow of residual oxygen from the preparation chamber; therefore, the final composite was TiN/Ti-O-WS₂. The observation of the composite film by scanning and transmission electron microscopies showed the incorporation of the WS₂ nanoparticles; however, their bonding with the matrix was weak. The analysis of the wear tracks did not show any presence of WS₂ in the contact.     

Speaker-specific-text based speaker verification system using spectral and phase based features

In speaker recognition tasks, one of the reasons for reduced accuracy is due to closely resembling speakers in the acoustic space. In order to increase the discriminative power of the classifier, the system must be able to use only the unique features of a given speaker with respect to his/her acoustically resembling speaker. This paper proposes a technique to reduce the confusion errors, by finding speaker-specific phonemes and formulate a text using the subset of phonemes that are unique, for speaker verification task using i-vector based approach. In this paper spectral features such as linear prediction cepstral co-efficients (LPCC), perceptual linear prediction co-efficients (PLP) and phase feature such as modified group delay are experimented to analyse the importance of speaker-specific-text in speaker verification task. Experiments have been conducted on speaker verification task using speech data of 50 speakers collected in a laboratory environment. The experiments show that the equal error rate (EER) has been decreased significantly using i-vector approach with speaker-specific-text when compared to i-vector approach with random-text using different spectral and phase based features.     

Conformation and stability of barley chymotrypsin inhibitor-2 (CI-2) mutants containing multiple lysine substitutions

A major goal of agricultural biotechnology is to increase thenutritional value of maize seed through the expression of heterologousproteins enriched in lysine. One promising candidate is barleychymotrypsin inhibitor-2 (CI-2), a plant protein that has beenextensively characterized with respect to structure and function.Based on the tertiary structure of wild-type (WT) CI-2, fivemutants with lysine contents ranging from 20 to 25 mol percentwere designed, expressed in Escherichia coli and purified byion exchange and gel permeation chromatography. Inasmuch asprevious transgenic experiments suggested that proper foldingand stability may be essential for in vivo accumulation of theengineered proteins in plant cells, we first undertook an invitro study of the conformation and thermodynamic stabilityof the CI-2 mutants in order to select an ideal candidate forplant expression. Mutant and WT CI-2 proteins had similar circulardichroism spectra, suggesting similar secondary structures.However, differences in the accessibility of the sole tryptophanresidue, Trp24, indicated that the local conformation differedamong the mutants. The thermodynamic stability of the mutantsranged from <2 to 4.9 kcal/mol compared with ~7 kcal/molfor the wild-type protein. In conjunction with proteolytic stabilitystudies, we have identified one mutant that has the potentialto be expressed in a stable manner in plant cells.     

A new image encryption algorithm based on heterogeneous chaotic neural network generator and dna encoding

This paper presents a new combined neural network and chaos based pseudo-random sequence generator and a DNA-rules based chaotic encryption algorithm for secure transmission and storage of images. The proposed scheme uses a new heterogeneous chaotic neural network generator controlling the operations of the encryption algorithm: pixel position permutation, DNA-based bit substitution and a new proposed DNA-based bit permutation method. The randomness of the generated chaotic sequence is improved by dynamically updating the control parameters as well as the number of iterations of the chaotic functions in the neural network. Several tests including auto correlation, 0/1 balance and NIST tests are performed to show high degree of randomness of the proposed chaotic generator. Experimental results such as pixel correlation coefficients, entropy, NPCR and UACI etc. as well as security analyses are given to demonstrate the security and efficiency of the proposed chaos based genetic encryption method.     

The Globus Replica Location Service: Design and Experience

Distributed computing systems employ replication to improve overall system robustness, scalability, and performance. A Replica Location Service (RLS) offers a mechanism to maintain and provide information about physical locations of replicas. This paper defines a design framework for RLSs that supports a variety of deployment options. We describe the RLS implementation that is distributed with the Globus Toolkit and is in production use in several Grid deployments. Features of our modular implementation include the use of soft-state protocols to populate a distributed index and Bloom filter compression to reduce overheads for distribution of index information. Our performance evaluation demonstrates that the RLS implementation scales well for individual servers with millions of entries and up to 100 clients. We describe the characteristics of existing RLS deployments and discuss how RLS has been integrated with higher-level data management services.     

（英）Orthogonal frequency division multiplexing for improving the performance of terahertz channel

Terahertz (THz) communication is considered to be one of the demanding technology for the upcoming 5G standards. The incredible demand for high rate through wireless channel necessitates the use of THz frequency for communication. The development of communication systems in this frequency band possess technical challenges as the characteristic of THz band is very much different from the present wireless channel. However, the advancements in the development of transceiver and antenna systems are rapidly bringing the THz communication into reality. The high path loss in THz band limits the communication range of this channel. Even, for a distance of few meters (>5m), the absorption coefficient is very high and hence the performance of the system is poor. Performance over this frequency channel can be enhanced by considering transmission windows over this band instead of the entire band. The transmission windows are the frequencies over which the absorption is relatively low. Though there is an improvement in the performance with this adaptive modulation scheme, but not sufficient for longer distance. Apart from path loss, the frequency selective nature of this high bandwidth channel is also a major reason for the poor performance of THz channel. Orthogonal Frequency Division Multiplexing (OFDM) is a promising solution to mitigate the effects of frequency selective nature of the wireless channel. OFDM has been exploited in this paper to improve the performance of terahertz channel. The results show that the Bit Error Rate (BER) of the terahertz channel is considerably improved with OFDM.     

Novel Ti/Al(OH)3 and Fe/Al(OH)3 Nano Catalyzed 4-Acetamidophenyl 3-((Z)-but-2-enoyl)phenylcarbamate Synthesis and its Molecular Docking,Quantum Chemical Studies

A series of novel 4-acetamidophenyl 3-((Z)-but-2-enoyl)phenylcarbamate based chalcone moieties have been synthesized via green chemical Ti/Al(OH)₃ and Fe/Al(OH)₃ nano catalyzed pathway and spectroscopic authentication of these synthesized molecules were interpreted by FT-IR, ¹H-NMR, ¹³C-NMR, Mass and elemental analysis. In-silico molecular docking studies of the compounds exhibited excellent binding energy (??8.06 kcal and ??8.94 kcal) towards the essential requirements of targeted compounds for EGFR receptor bearing quinazoline inhibitor (PDB ID: 1M17(Lapitinib). UV–Vis and fluorescence spectroscopy measurements evidenced that there is a significant effect on the absorption and emission spectra. Cyclic voltammetry (CV) studies reveal that HOMO and LUMO values of the compounds are evidenced that band along with intra molecular charge transfer character (D-π-A). The red shift maxima (500 nm) of the emission spectra in various solvent were increasing with the solvent polarity.

Graphical Abstract