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HDPE-chitosan composites (HC) prepared using maleic anhydride as compatibilizer and palm oil as plasticizer have been subjected to dielectric characterization and thermal studies. At a lower frequency HC films were seen to exhibit an increasing dielectric constant due to interfacial polarization of the chitosan. This increase in dielectric loss with increasing concentration of chitosan indicated the presence of relaxing dipoles in the system. The addition of palm oil to the optimised HC5 system showed improved segmental mobility due to the interaction of polar amine group in chitosan with HDPE. The thermal stability and activation energy of the composites were computed using Coats- Redfern model.

Background Assessing pathway activity levels is a plausible way to quantify metabolic differences between various conditions. This is usually inferred from microarray expression data. Wide availability of NGS technology has triggered a demand for bioinformatics tools capable of analyzing pathway activity directly from RNA-Seq data. In this paper we introduce XPathway, a set of tools that compares pathway activity analyzing mapping of contigs assembled from RNA-Seq reads to KEGG pathways. The XPathway analysis of pathway activity is based on expectation maximization and topological properties of pathway graphs. Results XPathway tools have been applied to RNA-Seq data from the marine bryozoan Bugula neritina with and without its symbiotic bacterium “Candidatus Endobugula sertula”. We successfully identified several metabolic pathways with differential activity levels. The expression of enzymes from the identified pathways has been further validated through quantitative PCR (qPCR). Conclusions Our results show that XPathway is able to detect and quantify the metabolic difference in two samples. The software is implemented in C, Python and shell scripting and is capable of running on Linux/Unix platforms. The source code and installation instructions are available at http://alan.cs.gsu.edu/NGS/?q=content/xpathway. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-2823-y) contains supplementary material, which is available to authorized users.

Marine invertebrates are a major source of bioactive natural products, many of which are produced by associated microbes. These compounds protect the invertebrate host against predators, competitors, or pathogens by affecting the cellular processes of the host’s adversary, but knowledge about the interaction of the host itself with these symbiont-produced natural products is limited. For example, larvae of the marine bryozoan, Bugula neritina, are defended from predation by the bryostatins, polyketides synthesized by its uncultured endosymbiont, “Candidatus Endobugula sertula.” Bryostatins are potent modulators of the eukaryotic signaling protein, protein kinase C (PKC) that is involved in many cellular processes. In this study, we investigated how host reproduction responds to the absence of the symbiont and symbiont-produced bryostatins in colonies after antibiotic curing and in colonies with naturally reduced symbiont titers. The fecundity of the symbiont-reduced B. neritina colonies was significantly decreased, suggesting that host reproduction is dependent on the symbiont, and/or the bryostatins they produce. To assess the role of PKC in this response, Western blot analysis of protein extracts from symbiotic and symbiont-reduced B. neritina colonies revealed a difference in bryostatin-activated conventional PKCs, but none for bryostatin-independent PKCs. Similar results were observed for PKCs in symbiotic and naturally occurring symbiont-reduced colonies, as well as in the model invertebrate, Caenorhabditis elegans, exposed to bryostatin, suggesting that the bryostatins potentially modulate PKC activity in symbiotic B. neritina and bryostatin-exposed C. elegans. Analysis of the B. neritina transcriptome led to the identification of five PKC isozymes. Since PKCs have been reported to be involved in regulation of reproductive processes and oocyte maturation in various organisms, the findings of this study suggest that the symbiont-produced bryostatins are an important cue for reproduction in the host B. neritina via PKC activation.

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40 alternate a-Si/SiN x multilayer are incorporated as an absorber layer in a p–i–n solar cell. The device is fabricated using hot-wire chemical vapor deposition (HWCVD) technique. The structure of the multilayer film is examined by high resolution transmission electron microscopy (HR-TEM) which shows distinct formation of alternate a-Si and SiN x layers. The a-Si and SiN x layers have thickness of ~3.5 and 4 nm, respectively. The photoluminescence (PL) of multilayer film shows bandgap energy of ~2.52 eV, is larger than that of the c-Si and a-Si. Dark and illuminated current–voltage (I–V) characterization of the ML films shows that these ML are photosensitive. In the present work, it is seen that the p–i–n structure with i-layer as ML quantum well (QW) structures show photovoltaic effect with relatively high open-circuit voltage (V OC). The increment of bandgap energy in PL and high V OC of the device is attributed to the quantum confinement effect (QCE).

This paper presents studies carried out on tin-doped indium sulfide films prepared using Chemical Spray Pyrolysis (CSP) technique. Effect of both in-situ and ex-situ doping were analyzed. Ex-situ doping was done by thermal diffusion, which was realized by annealing Sn/In2S3 bilayer films. In-situ doping was accomplished by introducing Sn into the spray solution by using SnCl4·5H2O. Interestingly, it was noted that by ex-situ doping, conductivity of the sample enhanced considerably without affecting any of the physical properties such as crystallinity or band gap. Analysis also showed that higher percentage of doping resulted in samples with low crystallinity and negative photosensitivity. In-situ doping resulted in amorphous films. In contrast to ex-situ doping, ‘in- situ doping’ resulted in widening of optical band gap through oxygen incorporation; also it gave highly photosensitive films.

Effect of chlorine doping on the opto-electronic properties of β-In 2 S 3 thin film, deposited by spray pyrolysis technique is studied for the first time. Chlorine was incorporated in the spray solution, using HCl. Pristine sample prepared using In(NO 3 ) 3 and thiourea as the precursors showed very low photosensitivity. But upon adding optimum quantity of chlorine, the photosensitivity increased by 3 orders. X-ray analysis revealed that crystallinity was also increasing up to this optimum level of Cl concentration. It was also observed that samples with high photosensitivity were having higher band gap. The present study proved that doping with chlorine was beneficial as this could result in forming crystalline and photosensitive films of indium sulfide.

Silver diffusion enhanced the properties of Indium sulfide (In2S3) films making it highly suitable buffer layer for photovoltaic applications. Thin layer of silver deposited over In2S3 films diffused into In2S3 films in ‘as-deposited’ condition itself creating doping effect. A significant enhancement in crystallinity and grain size could be obtained up to an optimum percentage of doping concentration. This optimum value showed dependence on thickness and atomic ratio of indium and sulfur in the film. Band gap decreased up to the optimum value of doping and thereafter it increased. Electrical studies showed a decrease in resistivity due to doping. Sample having the optimum doping was found to be more photosensitive and low resistive when compared with the pristine sample. These results proved that silver diffused indium sulfide surpasses pristine sample for crystallinity and photosensitivity. Doping β-In2S3 film with optimum amount of silver modified the structural and electrical properties of the films favorably so that the Ag electrodes given to the ITO/CuInS2/In2S3 cell structure itself acted as a doping agent for the In2S3 layer, enhancing the cell efficiency to 9.5% (John et al. Sol Energy Mater Sol Cells 89:27, 2005).

Copper indium sulfide (CuInS2)/In2S3 solar cells were fabricated using spray pyrolysis method and high short circuit current density and moderate open circuit voltage were obtained by adjusting the condition of deposition and thickness of both the layers. Consequently, a relatively high efficiency of 9.5% (active area) was obtained without any anti-reflection coating. The cell structure was ITO/CuInS2/In2S3/Ag. We avoided the usual cyanide etching and CdS buffer layer, both toxic, for the fabrication of the cell.

Mutualism, a beneficial relationship between two species, often requires intimate interaction between the host and symbiont to establish and maintain the partnership. The colonial marine bryozoan Bugula neritina harbors an as yet uncultured endosymbiont, "Candidatus Endobugula sertula," throughout its life stages. The bacterial symbiont is the putative source of bioactive complex polyketide metabolites, the bryostatins, which chemically defend B. neritina larvae from predation. Despite the presence of "Ca. Endobugula sertula" in all life stages of the host, deterrent bryostatins appear to be concentrated in reproductive portions of the host colony, suggesting an interaction between the two partners to coordinate production and distribution of the metabolites within the colony. In this study, we identified host genes that were differentially expressed in control colonies and in colonies cured of the symbiont. Genes that code for products similar to glycosyl hydrolase family 9 and family 20 proteins, actin, and a Rho-GDP dissociation inhibitor were significantly downregulated (more than twice) in antibiotic-cured non-reproductive zooids compared to control symbiotic ones. Differential expression of these genes leads us to hypothesize that the host B. neritina may regulate the distribution of the symbiont within the colony via mechanisms of biofilm degradation and actin rearrangement, and consequently, influences bryostatin localization to bestow symbiont-associated protection to larvae developing in the reproductive zooids.

In2S3 thin films appear to be a promising candidate for photovoltaic applications due to its stability, wide band gap and photosensitivity. The optical band gap value of Indium sulfide (In2S3) thin films reported in the literature varies from 2.0 eV to 2.4 eV following their synthesis process. These values are too small for an application as buffer layer in solar cells. In Present work, we report that incorporation of Sn using [SnCl4.5H2O] could increase the bandgap to wider ranges. In2S3/Sn thin films were deposited on soda lime glass substrate using chemical spray pyrolysis (CSP) technique. The spraying solution contained indium chloride (InCl3), thiourea [CS(NH2)2] and [SnCl4.5H2O]. Studies were done on films prepared using different Sn/In ratios. Depth profile using x-ray photoelectron spectroscopy showed that incorporation of Sn increased the concentration of oxygen in the samples. Band gap of the films increased with increase in Sn/In ratios. Depending on the ratios, bandgap could be varied from 2.72 eV to 3.78 eV. At lower mixing levels wide band gap low resistive In2S3/Sn films could be obtained which is highly useful for buffer layer applications. Low resistive buffer layer will decrease the series resistance of the cell and wider band gap will improve light transmission in the blue wavelength, both these factors help in increasing the short circuit current of the photovoltaic cell. Samples having higher Sn/In ratios showed wider band gap (up to3.78 eV).Though the samples had very high bandgap and high resistivity these samples were highly photosensitive [(IL-ID)/ID = 11,000]. The results proved that tin incorporation modified the band gap and electrical properties of the In2S3/Sn films favorably over wider ranges making it highly suitable for different optoelectronic applications.

The effect of doping spray pyrolyzed thin films of In2S3 with silver is discussed. It was observed that silver diffused into In2S3 films in as deposited condition itself. Depth profile using x-ray photoelectron spectroscopy clearly showed diffusion of silver into In2S3 layer without any annealing. X-ray analysis revealed significant enhancement in crystallinity and grain size up to an optimum percentage of doping concentration. This optimum value showed dependence on thickness and atomic ratio of indium and sulfur in the film. Band gap decreased up to the optimum value of doping and thereafter it increased. Electrical studies showed a drastic decrease in resistivity from 1.2×103to0.06Ωcm due to doping. A sample having optimum doping was found to be more photosensitive and low resistive when compared with a pristine sample. Improvement in crystallinity, conductivity, and photosensitivity due to doping of spray pyrolyzed In2S3 films with Ag helped to attain efficiency of 9.5% for Ag∕In2S3∕CuInS2∕ITO (indium...