Pentacenequinone derivative 3 forms luminescent supramolecular aggregates both in bulk as well as in solution phase. In bulk phase at high temperature, long-range stacking of columns leads to formation of stable and ordered columnar mesophase. Further, derivative 3 works as sensitive chemosensor for picric acid (PA) and gel-coated paper strips detect PA at nanomolar level and provide a simple, portable, and low-cost method for detection of PA in aqueous solution, vapor phase, and in contact mode.

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Novel pentacenequinone derivative 3 has been synthesized using the Suzuki-Miyaura coupling protocol which forms fluorescent nanoaggregates in aqueous media due to its aggregation-induced emission enhancement attributes and selectively senses picric acid with a detection limit of 500 ppb.

The adverse effect of Al3+ ions on human health as well as the environment makes it desirable to develop sensitive and specific techniques for the detection of Al3+ ions.

A simple, room temperature processetching of Si(100) surfaces in 40% NH4F(aq) solutionsproduces H-terminated surfaces of near-atomic smoothness over large areas (>1000 × 1000 Å2). The etched surface is primarily terminated by long alternating rows of strained and unstrained silicon dihydrides; no microfaceting or etching-induced surface roughness is observed. The Cartesian components of the infrared absorption spectrum of flat and vicinal etched surfaces show that the surface is almost entirely dihydride-terminated. This analysis disproves previous assignments of the infrared spectrum of NH4F-etched Si(100) which suggested that the etched surface was very rough and terminated by a variety of mono-, di-, and trihydride species. Although the steady-state etch morphology has lower interadsorbate strain than bulk-terminated H/Si(100), this morphology does not minimize interadsorbate strain as previously postulated. The relatively low reactivity of the strained dihydrides kinetically blocks this pathway.

Chemical functionalization of the technologically important face of silicon, Si(100), to form a passivated semiconductor/organic interface would enable a wide variety of applications, including microelectronic devices with integrated chemical or biological functionality; however, this goal has been stymied by the sterically hindered structure of the (100) surface, which impedes uniform chemical reaction. Here we demonstrate production of near-atomically flat H-functionalized Si(100) surfaces from a self-propagating chemical reaction that targets a previously unrecognized reactive pair of silicon atoms. Scanning tunneling microscopy, infrared spectroscopy, and kinetic Monte Carlo simulations are used to measure the surface-site-specific rates of chemical reaction and to quantitatively explain the observed morphologies. The production of uniform H-terminated Si(100) surfaces is controlled primarily by two aspects of dihydride reactivity. First, row-end dihydrides are 1000 times more reactive than similar midrow dihydrides. Second, dihydride reactivity is not monotonically correlated with interadsorbate strain of the reacting site. Instead, dihydride reactivity is correlated with interadsorbate strain release by adjacent dihydrides during the chemical reaction. This unusual dependence on interadsorbate strain produces a characteristic alternating row morphology dominated by single-atom-wide rows. The proposed reaction mechanism, which involves a silanone intermediate, explains the etch morphology, the site-specific reactivities, the reaction kinetics, the production of H 2 , and the hydrogen termination of the reacted surfaces. Strategies for the production of uniformly functionalized Si(100) surfaces based on this reaction are discussed.

Alteration in lipid peroxidation products such as lipid peroxides, lipid hydroperoxides were studied in different regions of CNS of ageing rats (13, 26, 52, 78 and 104 weeks). The levels of lipid peroxide and lipid hydroperoxide were increased in various regions of brain and spinal cord. However, the activity of superoxide dismutase was decreased in cerebrum, hypothalamus, hippocampus, cerebellum, brain stem and spinal cord. The present communication demonstrates that the different parts of CNS at 13 and 26 weeks of age have lipid peroxidation products different from that of 104-week-old rats.

Paraphrase generation is an important problem in NLP, especially in question answering, information retrieval, information extraction, conversation systems, to name a few. In this paper, we address the problem of generating paraphrases automatically. Our proposed method is based on a combination of deep generative models (VAE) with sequence-to-sequence models (LSTM) to generate paraphrases, given an input sentence. Traditional VAEs when combined with recurrent neural networks can generate free text but they are not suitable for paraphrase generation for a given sentence. We address this problem by conditioning the both, encoder and decoder sides of VAE, on the original sentence, so that it can generate the given sentence's paraphrases. Unlike most existing models, our model is simple, modular and can generate multiple paraphrases, for a given sentence. Quantitative evaluation of the proposed method on a benchmark paraphrase dataset demonstrates its efficacy, and its performance improvement over the state-of-the-art methods by a significant margin, whereas qualitative human evaluation indicate that the generated paraphrases are well-formed, grammatically correct, and are relevant to the input sentence. Furthermore, we evaluate our method on a newly released question paraphrase dataset, and establish a new baseline for future research.