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Calmodulin (CaM) plays an important regulatory role in plant growth and development. In this study, on the basis of previous transcriptomic annotation a homolog of CaM gene (Pc-CaM7) was identified from the red alga Phycocalida chauhanii (previously known as Porphyra chauhanii). It encoded a 151 amino acids protein with 4 EF-hand regions, which was the typical structure of calmodulin family proteins. Evolutionary analysis showed that Pc-CaM7 shared conserved orthologous relationships with CaMs from Neoporphyra haitanensis (formerly Pyropia haitanensis), Porphyra umbilicalis, and Gracilariopsis chorda. During the developmental period of P. chauhanii gametophytic germlings from 25- to 50-day-old, the asexual archeospores were continuedly released from the marginal region of blades, followed by the emergence of spermatangia from 40-day-old germlings. Based on quantitative real-time PCR analysis, it showed that expression trend of Pc-CaM7 was correlated with the rule of archeospores’ formation and release, whereas in N. haitanensis without archeospore characteristic, the expression pattern of the orthologous gene (Pha_00404) was different, which increased and reached a plateau during the same developmental period. These findings suggested that Pc-CaM7 may be involved in the process of archeospores formation and release, which may provide a foundation for understanding the molecular mechanisms of asexual reproduction in Bangiales.

In this work, we prepared the epoxy-based adhesives with a binary filler system, which was composed of organosilicon modified hexagonal BN (h-BN) and α-Al2O3. H-BN platelets and α-Al2O3 nanoparticles were decorated by aminopropyltrimethoxysilane (APTMS) and glycidylpropyltrimethoxysilane (GPTMS), respectively, to form covalent links to the filler/polymer matrix interface. The surface chemical composition was investigated by Fourrier transform infrared spectroscopy (FTIR) and thermogravimetry analysis (TGA), which demonstrated that the modifiers were successfully grafted onto the surface of fillers. This modification has been confirmed beneficial to thermal conductivity so that the thermal conductivity of adhesives incorporated with modified binary fillers could reach 0.85 w/m k, which is 10% more than specimen filled with unmodified fillers, because covalent links strengthened the interface and prohibited heat diffusion. Modified Hashin–Shtrikman model was utilized to analyze thermal resistance of the binary filler system, indicating that adhesives filled with modified fillers displayed lower thermal resistance. The enhancement of interface also brought about some other positive effect, especially in the decreasing of dielectric constant ( 1014). Furthermore, the mechanical strength is significantly improved when the modified binary fillers were used.

Dictyopteris divaricata is a kind of important brown algae with many biological activities. It has been receiving more and more attention, yet there are rarely studies done on its polysaccharides. In this study, the optimum extraction and biological activity of seaweed polysaccharides from Dictyopteris divaricata (DDSP) were investigated. Response surface methodology (RSM), based on a three-level, three-variable Box-Behnken design (BBD), was employed to obtain the best possible combinations for maximum polysaccharides yield. The optimum extraction conditions were as follows: liquid-solid ratio of 110 mL/g, extraction time of 6 h and extraction temperature of 100 °C. Under these conditions, the experimental yield was 3.05%, which was in close agreement with the predicted value of 3.15%. The average molecular weight of DDSP was 58.05 kDa. Gas chromatograph (GC) results showed that DDSP was composed of fucose, xylose, mannose, glucose and galactose with the corresponding molar ratio of 4.45:2.74:1.00:2.94:1.35. Biological activity showed that DDSP exhibited strong antioxidant activity in vitro and possessed the potential on stimulating immune response of RAW264.7 cells. So DDSP can be used as a natural ingredient in functional foods.

Superhydrophobic surfaces on the basis of hierarchical ZnO particles grafted by fluoroethylene-vinylether (FEVE) polymer derivative were prepared using a facile, mild and low-cost method. X-ray diffraction (XRD) and scanning electron microscope (SEM) revealed that the resulting ZnO particles via hydrothermal process exhibit micro–nano dual-scale morphology with high purity under a suitable surfactant amount and alkali concentration. The grafting of FEVE derivative was confirmed by Fourier transform infrared spectroscopy (FTIR) and energy-dispersive X-ray spectrometer (EDS), suggesting that hierarchical surface of ZnO particles was an imported monomolecular layer of fluorocarbon polymer. The obtained surface fabricated by drop-casting shows considerably high contact angle and good resistance to water immersion. The wetting behavior in this work was furthermore analyzed by theoretical wetting model. This work demonstrates that the sufficient low-wettable surface and high roughness both take a vital role in the superhydrophobic behavior.

In this study, poly(methylphenylsiloxane) (PMPS) and phenylene-silica based hybrid material with interpenetrating networks was prepared by a two-step sol–gel process. Firstly, in the presence of H2SO4, the phenylene-silica was formed as sol particles with high branching degree by cohydrolysis and condensation of phenylene-bridged monomer, tetraethoxysilane (TEOS), and hexamethyldisiloxane (MM). Then, the intermediate transformed into gel framework in polymer matrix using alkali catalyst, in order to produce a homogenous hybrid material with interpenetrating networks. The structure of prepared hybrid material was characterized by FTIR and NMR, suggesting that phenylene-silica framework was imported into polymer matrix and the hybrid products have a much higher network chain density than neat PMPS. The thermogravimetric analysis (TGA) shows that the prepared materials start to degrade at around 490°C. The results of tensile test indicate that the typical PMPS/phenylene-silica hybrid material has a tensile strength up to 26 MPa and demonstrate a certain degree of flexibility. An increase of phenylene content in phenylene-silica particles tends to produce hybrid materials with improved thermal stability and tensile strength. The hybrid coating films after calcinating at 350 and 400°C for 2 h exhibit a good mechanical performance on adhesion, impact strength and flexibility. Electrochemical impedance spectroscopy (EIS) measurements show that the investigated films have an extremely high electric resistance (1010 Ohm·cm2) and a satisfied impermeability to 3.5 wt % sodium chloride solution. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Studying the binding properties of cellulases to lignocellulosic substrates is critical to achieving a fundamental understanding of plant cell wall saccharification. Lignin auto-fluorescence and degradation products formed during pretreatment impede accurate quantification of individual glycosyl hydrolases (GH) binding to pretreated cell walls. A high-throughput fast protein liquid chromatography (HT-FPLC)-based method has been developed to quantify cellobiohydrolase I (CBH I or Cel7A), cellobiohydrolase II (CBH II or Cel6A), and endoglucanase I (EG I or Cel7B) present in hydrolyzates of untreated, ammonia fiber expansion (AFEX), and dilute-acid pretreated corn stover (CS). This method can accurately quantify individual enzymes present in complex binary and ternary protein mixtures without interference from plant cell wall-derived components. The binding isotherms for CBH I, CBH II, and EG I were obtained after incubation for 2 h at 4 °C. Both AFEX and dilute acid pretreatment resulted in increased cellulase binding compared with untreated CS. Cooperative binding of CBH I and/or CBH II in the presence of EG I was observed only for AFEX treated CS. Competitive binding between enzymes was found for certain other enzyme-substrate combinations over the protein loading range tested (i.e., 25-450 mg/g glucan). Langmuir single-site adsorption model was fitted to the binding isotherm data to estimate total available binding sites E(bm) (mg/g glucan) and association constant K(a) (L/mg). Our results clearly demonstrate that the characteristics of cellulase binding depend not only on the enzyme GH family but also on the type of pretreatment method employed.

A silicone resin with silphenylene units in Si—O—Si backbones was prepared through hydrolysis-polycondensation of self-synthesized 1,4-bis(diethoxymethylsilyl)benzene (BDSB) and other alkoxysilanes. The structure and properties of this novel silicone resin were characterized by gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), thermogravimetric analysis (TG), scanning electron microscope (SEM) and electrochemical impedance spectrum (EIS). The results of GPC, IR and NMR showed that silphenylene units had been successfully incorporated into the backbones of silicone resin. TG analyses reveal that silicone resin with silphenylene units in its backbones had a higher heat resistance than the usual methyl phenyl silicone resin. SEM results demonstrated that this silicone resin could form a full and uniform film, and its clear paints were able to stand temperatures below 350 °C. EIS analysis revealed that clear paints of this silicone resin have good resistance to corrosion.

We have applied a rational four-step strategy to identify novel bacterial glycosyl hydrolases (GH), in combination with various fungal enzymes, in order to define an efficient enzyme cocktail to hydrolyze pretreated lignocellulosic biomass. The fungal cellulases include cellobiohydrolase I (CBH I; GH family 7A), cellobiohydrolase II (CBH II; GH family 6A), endoglucanase I (EG I; GH family 7B) and ��-glucosidase (��G; GH family 3). Bacterial endocellulases (LC1 and LC2; GH family 5), ��-glucosidase (L��G; GH family 1), endoxylanases (LX1 and LX2; GH family 10) and ��-xylosidase (L��X; GH family 52) from multiple sources were cloned, expressed and purified as well. Enzymatic hydrolysis for various enzyme combinations was performed on Ammonia Fiber Expansion (AFEX) treated corn stover at various total protein loadings (30, 15 and 10 mg enzyme/g glucan). The optimal mass ratio of enzymes necessary for obtaining high glucan and xylan yields was determined using a suitable mixture design of experiments. The optimal hybrid enzyme mixtures contain fungal cellulases (78% of total protein loading), which include CBH I (loading ranging between 9-51% of total enzyme load), CBH II (9-51%), EG I (10-50%), and bacterial hemicellulases (22% of total protein loading) comprising of LXl (13%) and L��X (9%). The hybrid mixture works effectively at 50 ��C and pH 4.5 to efficiently saccharify AFEX treated corn stover giving as high as 95% glucan and 65% xylan conversion, respectively. This strategy of screening enzyme mixtures on pretreated lignocellulose will ultimately help develop enzyme cocktails that can hydrolyze plant cell walls efficiently and economically to produce cellulosic ethanol.

Resistance of silicone resin to heat and irradiation was studied. The chemical structure of silicone resin before and after being heated and irradiated was analyzed by Fourier Transform Infrared Spectroscopy (FT-IR). The thermal stability of silicone resin was investigated by thermogravimetric analysis (TG) and differential thermogravimetry analysis (DTG), and its improvement was indicated by TG and DTG analyses of silicone resin after being irradiated by 60Co γ-ray under different fluence. The surface morphology, mechanical properties, corrosion resistance and chemical resistance of silicone resin clear paints before and after being heated and irradiated were studied by SEM, EIS et al.

The possible roles of reduced glutathione(GSH) in chilling tolerance were studied in callus generated from a representative alpine plant, Chorispora bungeana Fisch. & C.A. Mey (C. bungeana). The callus grew well under low-temperature and chilling treatment led only to slight injury, as indicated by a low level of ion leakage (IL). Malondialdehyde measurements also were not elevated, however GSH was. Exogencrusly application of L-buthionine-(S R)-sulfoximine (BSO), an inhibitor of gamma-glutamylcysteine synthetase (gamma-ECS), arrested the GSH accumulation induced by chilling and resulted in a significant decrease in cell growth and an increase in IL and malondialdehyde. These results implied that C. bungeana is a plant with a strong low-temperature tolerance mechanism, and the tolerance of C, bungeana may be associated with GSH accumulation. Under chilling treatment, the proportion of unsaturated fatty acid in the plasma membrane (PM) increased significantly in callus of C. bungeana mainly due to increases in C18:2 and C18:3, the membrane fluidity (indicated by DPH fluorescent polarization) however was maintained. High PM H+-ATPase activities were also induced by chilling. Exogenously application of BSO blocked the effects of chilling treatments on the changes of fatty acids and PM H+-ATPase activities, reducing the PM membrane fluidity. On the other hand, simultaneous application of GSH and BSO to callus under chilling treatments reversed the effects of BSO on the changes of fatty acids, PM fluidity and PM H+-ATPase activities. These results Suggested that GSH induced by low-temperature treatments may confer chilling tolerance to C. bungeana, probably by increasing unsaturated fatty acid compositions and maintaining PM fluidity and high enzymatic activity. (C) 2008 Elsevier Inc. All rights reserved.

In this work, six core glycosyl hydrolases (GH) were isolated and purified from various sources to help rationally optimize an enzyme cocktail to digest ammonia fiber expansion (AFEX) treated corn stover. The four core cellulases were endoglucanase I (EG I, GH family 7B), cellobiohydrolase I (CBH I, GH family 7A), cellobiohydrolase II (CBH II, GH family 6A) and ?-glucosidase (?G, GH family 3). The two core hemicellulases were an endo-xylanase (EX, GH family 11) and a ?-xylosidase (?X, GH family 3). Enzyme family and purity were confirmed by proteomics. Synergistic interactions among the six core enzymes for varying relative and total protein loading (8.25, 16.5 and 33 mg/g glucan) during hydrolysis of AFEX-treated corn stover was studied using a high-throughput microplate based protocol. The optimal composition (based on% protein mass loading) of the cocktail mixture was CBH I (28.4%): CBH II (18.0%): EG I (31.0%): EX (14.1%): ?G (4.7%): ?X (3.8%). These results demonstrate a rational strategy for the development of a minimal, synergistic enzymes cocktail that could reduce enzyme usage and maximize the fermentable sugar yields from pretreated lignocellulosics. � 2009 Elsevier Ltd.