Synthesis and Superior Optical‐Limiting Properties of Fluorene‐Thiophene‐Benzothiadazole Polymer‐Functionalized Graphene Sheets

A polymer based on fluorene, thiophene, and benzothiadazole as the donor–spacer–acceptor triad is covalently coupled to reduced graphene oxide (rGO) sheets via diazonium coupling with phenyl bromide, followed by Suzuki coupling. These polymer–graphene hybrids show good solubility in organic solvents, such as chloroform, tetrahydrofuran (THF), toluene, dichlorobenzene, and N,N‐dimethylformamide (DMF), and exhibit an excellent optical‐limiting effect with a 532‐nm laser beam. The optical‐limiting threshold energy values (0.93 J cm^?2 for G–polymer 1 and 1.12 J cm^?2 for G–polymer 2) of these G–polymer hybrids are better than that of carbon nanotubes (3.6 J cm^?2).     

米曲霉发酵大米中抗氧化物质对酪氨酸酶的抑制作用

本实验采用两种不同米曲霉菌种(Aspergillus soji,A.orgzae)在35℃和湿度>90%的条件下对大米进行固态发酵6 d,比较发酵大米在发酵过程中活性物质的金属螯合、多酚氧化酶抑制、氧自由基吸收能力及总酚含量的变化。A.orgzae发酵的大米在金属螯合、多酚氧化酶抑制和氧自由基吸收能力上优于A.soji,两者在总酚含量上没有较大差别,且在发酵第4 d时大米的上述四项活性都趋于稳定,故选取A.orgzae发酵4 d的大米探讨其所含活性物质对酪氨酸酶的抑制作用。采用Lineweaver-Burk双倒数法探讨A.orgzae发酵大米中活性物质对蘑菇酪氨酸酶催化L-多巴氧化的抑制作用并推测其抑制机理。同时,虾血淋巴和虾黑变的抑制实验也证明了米曲霉发酵大米对酪氨酸酶的有效抑制作用。     

Effects of koji fermented phenolic compounds on the oxidative stability of fish miso

In the present study, Aspergillus oryzae-inoculated koji inhibited lipid oxidation in fermented fish paste rich in polyunsaturated fatty acids following a long fermentation period. The fermentation of koji by A. oryzae liberated several bioactive phenolic compounds, including kojic acid and ferulic acid, which were the most abundant. A linear correlation between several phenolic compounds and their bioactive properties, including their radical-scavenging activity, reducing power, metal-chelating activity, and ability to inhibit linoleic acid oxidation was observed. This suggested an important role of koji phenolics in the oxidative stability of fermented fish paste. The activities of different carbohydrate-cleaving enzymes, including α-amylase, cellulase, and β-glucosidase, were positively correlated with the liberation of several phenolic compounds through koji fermentation. Thus, the application of koji offers a novel strategy to enhance the oxidative stability of newly developed fermented fish miso. PRACTICAL APPLICATION: Application of traditional Japanese koji fermentation technique to develop an aroma enriched fish meat bases seasoning has been established. Aspergillus oryzae-inoculated koji releases several carbohydrate-cleaving enzymes, including α-amylase, cellulose, and β-glucosidase, which led to the liberation of several phenolic compounds during fermentation. Improvement of oxidative stability of the fermented fish meat paste by koji phenolics suggests a useful strategy to uplift the value of different trash fish meat-based seasoning through proper utilization of the present technique.     

A dependency annotation scheme for Bangla treebank

Dependency grammar is considered appropriate for many Indian languages. In this paper, we present a study of the dependency relations in Bangla language. We have categorized these relations in three different levels, namely intrachunk relations, interchunk relations and interclause relations. Each of these levels is further categorized and an annotation scheme has been developed. Both syntactic and semantic features have been taken into consideration for describing the relations. In our scheme, there are 63 such syntactico–semantic relations. We have verified the scheme by tagging a corpus of 4167 Bangla sentences to create a treebank (KGPBenTreebank).     

Design and simulation of a parallel inference machine architecture for rule based systems

This paper presents an architecture of the inference machine for a rule based expert system. The paper, structured around the concept of “inference flow graphs”, is aimed at incorporating parallelism in antecedent matching to find out the firable rules as well as firing more than one rule simultaneously, whenever required. Through this architecture, the number of comparisons required during the antecedent matching phase, is significantly reduced. The flow of inferencing can also proceed in a pipelined manner resulting in faster inferences.     

DYNAMIC ENVIRONMENT ROBOT PATH PLANNING USING HIERARCHICAL EVOLUTIONARY ALGORITHMS

The problem of path planning deals with the computation of an optimal path of the robot, from source to destination, such that it does not collide with any obstacle on its path. In this article we solve the problem of path planning separately in two hierarchies. The coarser hierarchy finds the path in a static environment consisting of the entire robotic map. The resolution of the map is reduced for computational speedup. The finer hierarchy takes a section of the map and computes the path for both static and dynamic environments. Both the hierarchies make use of an evolutionary algorithm for planning. Both these hierarchies optimize as the robot travels in the map. The static environment path is increasingly optimized along with generations. Hence, an extra setup cost is not required like other evolutionary approaches. The finer hierarchy makes the robot easily escape from the moving obstacle, almost following the path shown by the coarser hierarchy. This hierarchy extrapolates the movements of the various objects by assuming them to be moving with same speed and direction. Experimentation was done in a variety of scenarios with static and mobile obstacles. In all cases the robot could optimally reach the goal. Further, the robot was able to escape from the sudden occurrence of obstacles.     

Integrated semiconductor nanocrystal and epitaxical nanostructure systems: structural and optical behavior

Integration of semiconductor epitaxical nanostructures and nanocrystals into two classes of quantum structures, uncovered adsorbed nanocrystals or buried via epitaxical overgrowth, is successfully demonstrated through structural and optical studies. The combination InGaAs/GaAs epitaxical structures and InAs nanocrystals is employed as a vehicle with the functional aim of exploiting the well developed optoelectronic communication technology based on the former with the biochemical and biomedical applications for which the latter are well suited.     

Rapid synthesis of silver nanoparticles by Pseudomonas stutzeri isolated from textile soil under optimised conditions and evaluation of their antimicrobial and cytotoxicity properties

Present study utilised textile soil isolated bacterium Pseudomonas stutzeri to synthesise extracellular silver nanoparticles (AgNPs) under optimised conditions. The synthesised AgNPs were characterised using ultraviolet‐visible spectroscopy, Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). Optimisation showed AgNPs synthesis within 8 h using 2mM Ag nitrate at pH9, temperature 80°C and maximum absorbance toward 400 nm. TEM analysis revealed spherical shape AgNPs and reduction in size upto 8 nm was observed under optimised conditions. FTIR spectra confirmed presence of proteins bound to AgNPs act as reducing agent. AgNPs showed strong antibacterial activity against multi‐drug resistant (MDR) Escherichia coli and Klebsiella pneumoniae as demonstrated by disc diffusion and colony forming unit assays. Zone of inhibition increased with increasing concentration of AgNPs with maximum of 19 mm against E. coli and 17 mm against K. pneumoniae at concentration of 2 μg/disc. Furthermore, AgNPs did not show any cytotoxic effects on human epithelial cells as demonstrated by 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl tetrazolium bromide assay even at 2 μg/ml concentration of AgNPs. The results of the present study suggest that AgNPs can be synthesised rapidly under optimised conditions and show strong antimicrobial property against MDR pathogens without having toxicity effect on human epithelial cells.Inspec keywords: ultraviolet spectra, proteins, transmission electron microscopy, infrared spectra, Fourier transform spectra, visible spectra, microorganisms, toxicology, cellular biophysics, biomedical materials, antibacterial activity, nanomedicine, nanofabrication, nanoparticles, silverOther keywords: 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl tetrazolium bromide assay, human epithelial cells, cytotoxic effects, K. pneumoniae, colony forming unit counting assays, disc diffusion, Klebsiella pneumoniae, Escherichia coli, multidrug resistant, stabilising agent, reducing agent, proteins, parametric optimisation, TEM, transmission electron microscopy, FTIR spectra, Fourier transform infrared spectroscopy, ultraviolet‐visible spectroscopy, bacterium, cytotoxicity properties, antimicrobial properties, textile soil, Pseudomonas stutzeri, silver nanoparticle synthesis     

Multi-robot multi-target dynamic path planning using artificial bee colony and evolutionary programming in unknown environment

Navigation or path planning is the basic need for movement of robots. Navigation consists of two foremost concerns, target tracking and hindrance avoidance. Hindrance avoidance is the way to accomplish the task without clashing with intermediate hindrances. In this paper, an evolutionary scheme to solve the multi-agent, multi-target navigation problem in an unknown dynamic environment is proposed. The strategy is a combination of modified artificial bee colony for neighborhood search planner and evolutionary programming to smoothen the resulting intermediate feasible path. The proposed strategy has been tested against navigation performances on a collection of benchmark maps for A* algorithm, particle swarm optimization with clustering-based distribution factor, genetic algorithm and rapidly-exploring random trees for path planning. Navigation effectiveness has been measured by smoothness of feasible paths, path length, number of nodes traversed and algorithm execution time. Results show that the proposed method gives good results in comparison to others.