Wheat gluten films cross-linked with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide

Wheat gluten films were cast from aqueous dispersions containing 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS) as cross-linking reagents and glycerol as a plasticizer. Cross-linking was carried out to improve film properties such as water sensitivity and tensile strength. Films were characterized by measuring protein and water content, amount of amino groups, swelling of the films in water, and mechanical properties such as tensile strength (σ_max) and strain at maximum stress ( at σ_max). The use of different ratios of EDC to COOH resulted in different tensile properties and different percentage of swelling, which was attributed to the degree of cross-linking in the film. At a ratio of EDC/NHS/COOH=0.5/0.5/1, films had a water content of 10–11.5% and showed the highest σ_max (2.8±0.9 MPa), the lowest at σ_max (142±67%), and the lowest swelling (46%) compared to σ_max=1.7±0.4 MPa, at σ_max=257±63%, and swelling=68% for native gluten films.     

Biomedical exploitation of chitin and chitosan via mechano-chemical disassembly, electrospinning, dissolution in imidazolium ionic liquids, and supercritical drying

Recently developed technology permits to optimize simultaneously surface area, porosity, density, rigidity and surface morphology of chitin-derived materials of biomedical interest. Safe and ecofriendly disassembly of chitin has superseded the dangerous acid hydrolysis and provides higher yields and scaling-up possibilities: the chitosan nanofibrils are finding applications in reinforced bone scaffolds and composite dressings for dermal wounds. Electrospun chitosan nanofibers, in the form of biocompatible thin mats and non-wovens, are being actively studied: composites of gelatin + chitosan + polyurethane have been proposed for cardiac valves and for nerve conduits; fibers are also manufactured from electrospun particles that self-assemble during subsequent freeze-drying. Ionic liquids (salts of alkylated imidazolium) are suitable as non-aqueous solvents that permit desirable reactions to occur for drug delivery purposes. Gel drying with supercritical CO(2) leads to structures most similar to the extracellular matrix, even when the chitosan is crosslinked, or in combination with metal oxides of interest in orthopedics.     

3-[4-(1H-Indol-3-yl)-1,3-thiazol-2-yl]-1H-pyrrolo[2,3-b]pyridines,Nortopsentin Analogues with Antiproliferative Activity

A new series of nortopsentin analogues, in which the imidazole ring of the natural product was replaced by thiazole and the indole unit bound to position 2 of the thiazole ring was substituted by a 7-azaindole moiety, was efficiently synthesized. Two of the new nortopsentin analogues showed good antiproliferative effect against the totality of the NCI full panel of human tumor cell lines (~60) having GI₅₀ values ranging from low micromolar to nanomolar level. The mechanism of the antiproliferative effect of these derivatives, investigated on human hepatoma HepG2 cells, was pro-apoptotic, being associated with externalization of plasma membrane phosphatidylserine and mitochondrial dysfunction. Moreover, the compounds induced a concentration-dependent accumulation of cells in the subG0/G1phase, while confined viable cells in G2/M phase.     

Fractionation of Oat (1→3), (1→4)-β-D-Glucans and Characterisation of the Fractions

A commercial sample of oat β-glucan was fractionated through stepwise precipitation with ammonium sulphate to yield four fractions. These were analysed for apparent viscosity values, relative molecular weights using high-performance size-exclusion chromatography, and chemical structure by methylation analysis and analysis of water-soluble fragments released from the fractions by lichenase. Fractions exhibiting lower molecular size and decreased limiting viscosity values were precipitated at higher concentrations of ammonium sulphate. Methylation analysis indicated that in all fractions β-(1→3) and β-(1→4) linkages represented more than 90% of all linkages present. The β-(1→3) to β-(1→4) ratio in the fractions decreased with molecular size. β-glucan fractions with distinct physical and structural characteristics were obtained with the ammonium sulphate fractional precipitation technique.     

Preparation and properties of 2-(2-aminoethoxy) ethyl chitosan/cellulose fiber using N-methylmorpholine-N-oxide process

N-methylmorpholine-N-oxide (NMMO) is used widely in the manufacturing of man-made cellulose fibers and functional lyocell fibers due to its environment-friendly advantage. Although chitosan is known as a natural antibacterial polymer it has poor solubility in neutral to basic medium and the antibacterial activity is shown only in acidic medium. Chitosan’s poor solubility in NMMO is the disadvantage for the production of antibacterial lyocell fibers. This paper investigates a more “NMMO soluble” derivative of chitosan, 2-(2-aminoethoxy) ethyl chitosan (AECS). AECS has greatly improved solubility in NMMO hydrate, and stronger antibacterial activity than chitosan. AECS was introduced to modify the lyocell fiber spun in a co-solution of cellulose and AECS in NMMO hydrate. The physical properties and antibacterial activity of the fibers were examined and the results indicated that the modified lyocell fiber, containing more than 2 wt% of AECS, exhibits good antibacterial activity against E. coli and slightly decreased tensile strength compared with unmodified fibers.     

Synthesis,characterization of poly(E)-3-amino-4-((3-bromophenyl)diazenyl)-1H-pyrazol-5-ol: Investigation of antibacterial activity,fluorescence, and optical properties

The oxidative polycondensation reaction conditions of (E)-3-amino-4-((3-bromophenyl)diazenyl)-1H-pyrazol-5-ol (Schiff base monomer) has been accomplished using NaOCl, and air O₂ oxidants in an aqueous alkaline medium. The optical conductivity, dielectric and optical properties of synthesized poly(Schiff base) were examined. The magnitude of the refractive index decreases with increasing of photon energy up to about 2.5 eV, then refractive index of the poly(Schiff base) increases with increasing of photon energy. The E₀ and E_d values of the poly(Schiff base) were found to be 5.34 and 9.22 eV, respectively. An indirect energy-gap value of the poly(Schiff base) was found to be 0.94±0.009 eV. A direct energy-gap value of the poly(Schiff base) was found to be 1.38±0.01 eV and 1.96±0.009 eV at first region and second region, respectively. Absorption coefficient K changes from 11.87 to 18.25 cm^?1. In addition to fluorescence property of poly(Schiff base) was investigated. Finally, poly(Schiff base) and Schiff base monomer were tested for antibacterial activities against some bacteria.     

Synthesis and electropolymerization of 9-(4-vinylbenzyl)-9H-carbazole on carbon fiber microelectrode: Capacitive behavior of poly(9-(4-vinylbenzyl)-9H-carbazole)

The synthesis of 9-(4-vinylbenzyl)-9H-carbazole (VBCz) monomer and surface characterizations of thin film coating of poly(9-(4-vinylbenzyl)-9H-carbazole), P(VBCz) homopolymer on carbon fiber microelectrode (CFME) was performed. Coatings of polymer thin films obtained, with different initial monomer concentrations, were characterized by cyclic voltammetry, scanning electron microscopy and Fourier transform infrared reflectance-attenuated total reflection spectroscopy. Different initial monomer concentrations (1, 3, 5, and 10 mM) were electrodeposited in 0.1 M lithium perchlorate/acetonitrile solution. The characterization of the thin polymer films was performed on the surface of carbon fiber, and composition of polymeric structure was proposed. Capacitor behavior of modified CFME was studied by electrochemical impedance spectroscopy. The deposition charge of polymer growth affected the redox parameters of resulting coated CFME.     

Isolation of beta-(1-3) glucan compound from the water extract of indonesian jamur tanduk (Termitomyces eurirrhizus Berk)

Jamur Tanduk (Termitomyces eurirrhizus Berk) is one of uncultivated edible mushrooms from genus Termitomyces found in various regions in Indonesia. The purpose of this study is to analyze the chemical structure of its beta-glucan compound that possesses bioactivity as lowering cholesterol levels. Isolation and identification of beta-glucan compound from water extract of Jamur tanduk (local name), Termitomyces eurirrhizus Berk collected in Sumedang has been done. beta-glucan was isolated with Wasterlund methods and obtained as white powder. Isolated compound was identified based on interpretation of spectroscopies data such as Ultra-Violet (UV), Infra-Red (IR) and nuclear magnetic resonance one dimensional such as 1Hidrogen-Nuclear Magnetic Resonance (1H-NMR), 13Carbon- 13C-NMR) and Distortionless Enhancement by Polarization Transfer (DEPT) and two dimensional such as Correlation spectroscopy (COSY), Hetero Multiple Quantum Connectivity (HMQC) and Hetero Multiple Bond Connectivity (HMBC). The determination of molecule weight of sample based on viscosity measurements and obtained that beta-glucan has 322 molecules of glucose.     

Modification of ramie with 1-butyl-3-methylimidazolium chloride ionic liquid

For a long time, alkali is the main modification reagent for ramie modification due to its good effect and low cost. However, the large consumption of alkali in the processing leads to a serious pollution to the environment. To develop a new eco-friendly modification method, a mixed green solvent composed of 95 wt% 1-butyl-3-methylimidazolium chloride ionic liquid and 5 wt% water was employed in the paper. The swelling ratio, surface composition and crystal index was studied in detail with video microscope, FTIR and XRD analysis. Results showed that the solvent system had a distinct swelling effect on ramie. The crystal index of ramie fiber decreased from 74.2 % to 54.5 % after the treatment. Otherwise, the modification also removed some gummy substances including 75 % content of pectin in ramie. These changes improved the wetability and dyeing properties of ramie. However, the treatment also did much harm to the tensile strength.     

Synthesis,characterization and aggregation and fluorescence properties of novel highly soluble zinc phthalocyanines bearing tetrakis-4-(3-(piperidin-1-yl)phenoxy) with tetra and dodecachloro substituents

The synthesis of two new phthalocyanine precursors 4-(3-(piperidin-1-yl)phenoxy) with mono (2) and trichloro (3) substituents were carried out in this work. Cyclotetramerization of these precursors with zinc acetate gave novel tetrakis-4-(3-(piperidin-1-yl)phenoxy) with tetra (4) and dodecachloro (5) substituted zinc phthalocyanines. The synthesized new compounds were characterized using FT-IR, ¹H NMR, electronic absorption spectroscopy, mass spectra and elemental analysis. The aggregation behavior of zinc phthalocyanines 4 and 5 was investigated in different concentrations of dichloromethane (DCM). Zinc phthalocyanines 4 and 5 showed good solubility in different organic solvents such as DCM, CHCl₃, THF, benzene and toluene. Further, the aggregation behavior of zinc phthalocyanines 4 and 5 was studied before and after the addition of Triton X100. Further, the fluorescence quantum yields of zinc phthalocyanines 4 and 5 were calculated in the presence and absence of Triton X100.     

Rheological behavior and spinnability of ethylamine hydroxyethyl chitosan/cellulose co-solution in N-methylmorpholine-N-oxide system

In this work, the novel chitosan derivative ethylamine hydroxyethyl chitosan (EHC) was synthesized and blended with cellulose in an aqueous N-methylmorpholine-N-oxide (NMMO) solution in order to fabricate antibacterial chitosan/cellulose fiber. The rheological behaviors of the obtained co-solution in both steady and dynamic states were carefully investigated to determine the spinnability of the co-solution. In steady state, the addition of EHC was found to preserve the power-law flow characteristics of cellulose in the aqueous NMMO solution, while broadening the first Newtonian fluid-flow area. Under dynamic conditions, both Han-plot and viscoelastic analyses indicated the homogeneity of the co-solution. EHC/cellulose antibacterial fibers were successfully spun via the lyocell process using aqueous NMMO as the solvent, confirming the excellent spinnability of the EHC/cellulose co-solution. Scanning electron microscopy was used to observe the morphology of the obtained EHC/cellulose fibers; they were also investigated for antibacterial activity. The obtained EHC/cellulose fiber exhibited good spinning consistency and strong antibacterial activity against Escherichia coli, demonstrating potential applications for the material in antibacterial textiles.     

Preparation and acid dye adsorption behavior of polyurethane/chitosan composite foams

We prepared a series of polyurethane(PU)/chitosan composite foams with different chitosan content of 5∼20 wt% and investigated their adsorption performance of acid dye (Acid Violet 48) in aqueous solutions with various dye concentrations and pH values. It was observed that PU/chitosan composite foams exhibited well-developed open cell structures. Dye adsorption capacities of the composite foams increased with the increment of chitosan content in composite foams, because amine groups of chitosan serve as the binding sites for sulfonic ions of acid dyes in aqueous solutions. In addition, dye adsorption capacities of composite foams were found to increase with decreasing the pH value, which stems from the fact that the enhanced chemisorption between protonated amine groups of chitosan and sulfonic ions of acid dye is available in acidic solutions. The dye adsoption kinetics and equilibrium isotherm of the composite foams were well described with the pseudo-second order kinetic model and Langmuir isotherm model, respectively. The maximum adsorption capacity (q _max) for the PU/chitosan composite foams with 20 wt% chitosan content is evaluated to be ca. 30 mg/g.     

Effects of Cultivar and Environment on β-(1,3)-(1,4)- -glucan Content and Acid Extract Viscosity of Spanish Barleys

The acid extract viscosities and β-glucan contents of ten two- and six-rowed barley cultivars grown at seven locations in three consecutive years in Spain were studied in the present work. The viscosities varied from 2·4 to 24·8 centistokes (cSt) and the mean value was 6·4 cSt. The average β-glucan content of barleys determined by HPLC was 3·5% with a range of 1·9–5·5%. Significant differences were found in both β-glucan content and acid extract viscosity between different cultivars, locations and years. The β-glucan contents and viscosities of winter cultivars were higher than those of spring. Cvs. Barbarrosa and Hatif de Grignon were the genotypes with the highest values for both parameters, while cv. Beka had the lowest viscosity and β-glucan content. Environmental factors influenced both parameters. The acid extract viscosities of barleys were correlated negatively with the amount of precipitation (r=−0·754;P<0·05). Barleys grown in wet and rainy areas (Girona and La Coruña) had lower viscosity values.     

In vitro and in silico analysis of two genes (A2-1 and G1-1) differentially regulated during dormancy and sprouting in potato tubers

Summary Two cDNAs, corresponding to genes differentially regulated during dormancy and sprouting in potato tubers, cultivar Désirée, were isolated: i) G1-1 corresponded to a gene that was turned off during dormancy and turned on during early phases of sprouting; ii) A2-1 corresponded to a gene activated during dormancy and strongly repressed during the transition from dormancy to sprouting. When induced, both genes were expressed at low level. Full-length cDNAs and genomic clones were isolated and characterized. G1-1 was a short gene, 452 bp long, containing an intronless open reading frame, coding for a putative protein of 64 aminoacids. Sequence analysis showed that G1-1 was homologous to an expressed sequence tag (EST) ofArabidopsis thaliana. A2-1 full-length cDNA was 1577 bp long and contained an open reading frame coding for a putative protein of 383 aminoacids, which contained a Walker box binding domain, common to a multifunctional family of intracellular ATPases.     

Comparative stability studies of poly(2-methyl-2-oxazoline) and poly(ethylene glycol) brush coatings

Non-fouling surfaces that resist non-specific adsorption of proteins, bacteria, and higher organisms are of particular interest in diverse applications ranging from marine coatings to diagnostic devices and biomedical implants. Poly(ethylene glycol) (PEG) is the most frequently used polymer to impart surfaces with such non-fouling properties. Nevertheless, limitations in PEG stability have stimulated research on alternative polymers that are potentially more stable than PEG. Among them, we previously investigated poly(2-methyl-2-oxazoline) (PMOXA), a peptidomimetic polymer, and found that PMOXA shows excellent anti-fouling properties. Here, we compare the stability of films self-assembled from graft copolymers exposing a dense brush layer of PEG and PMOXA side chains, respectively, in physiological and oxidative media. Before media exposure both film types prevented the adsorption of full serum proteins to below the detection limit of optical waveguide in situ measurements. Before and after media exposure for up to 2 weeks, the total film thickness, chemical composition, and total adsorbed mass of the films were quantified using variable angle spectroscopic ellipsometry (VASE), X-ray photoelectron spectroscopy (XPS), and optical waveguide lightmode spectroscopy (OWLS), respectively. We found (i) that PMOXA graft copolymer films were significantly more stable than PEG graft copolymer films and kept their protein-repellent properties under all investigated conditions and (ii) that film degradation was due to side chain degradation rather than due to copolymer desorption.     

壳聚糖在茶树上的应用效应

采用叶面喷施的方法，对壳聚糖在茶树上的应用效应进行了研究。结果表明，壳聚糖能促进茶树芽叶萌发和生长，提高茶叶产量，增加茶叶中水浸出物和氨基酸含量，降低酚氨比。壳聚糖对茶叶中茶多酚含量有一定的影响，而对咖啡碱影响不大。本试验所设置浓度范围内，150mg／kg是叶面喷施壳聚糖较适宜的浓度。     

长穗颈不育系Ⅱ-32eA(1)制种“九二○”用量研究

在制种田中对长穗颈不育系Ⅱ-32eA(1)进行GA3不同用量的对比试验，结果表明：随着GA3用量的增加，不育系株高、穗颈长及异交结实率均显著增加；Ⅱ-32eA(1)在制种田中以30 g/hm2 GA3施用量最为合适，在这个施用量下，Ⅱ-32eA(1)株高(116.01 cm),穗颈长(0.57 cm)，异交结实率(37.13%)和理论产量(3.34 t/hm2)均为最高；Ⅱ-32eA(1)比Ⅱ-32A对GA3更为敏感，可大大减少制种中GA3的用量。     

Organic-inorganic hybrid of chitosan/poly (vinyl alcohol) containing yttrium(III) membrane for the removal of Cr(VI)

In this present study, an organic-inorganic hybrid membrane was prepared by embedding yttrium(III) into chitosan matrix for the removal of Cr(VI) from aqueous solutions. Several techniques, including fourier infrared spectrum (FTIR), scanning electron microscope (SEM), X-ray diffraction (XRD), and transmission electron microscope (TEM) are employed to characterize the properties of the membrane. The mechanical properties of the membrane were also examined. The chitosan/poly(vinyl alcohol) containing yttrium(III) (CY) membrane was experimentally used for the removal of Cr(VI) ions from aqueous solution under the optimized conditions. The results showed that the adsorption capacity for the removal of Cr(VI) ions was enhanced when yttrium(III) was introduced. The adsorption data from the experiment were fit well by Langmuir isotherm. Based on Langmuir model, q _m was calculated to be 38.48 mg g^?1. Kinetic study results indicated that the adsorption process followed a pseudo-second-order kinetics.