Effects of α-, β-, γ- and ω-Gliadins on the Dough Mixing Properties of Wheat Flour

Gliadins were extracted from wheat and individual groups (α-, β-, γ-, ω-1 and ω-2) purified. The effects of the individual groups of gliadin on the mixing properties of doughs from low and high protein flours were measured on a 2-g Mixograph and a prototype microextension tester. The addition of all groups of gliadin resulted in a decrease in dough strength. The relative weakening effects were ω-1>ω-2≈α-≈β->γ- in the Mixograph, and γ->α-≈β-≈ω-2≈ω-1 in the Extensograph.     

Cereal β-glucans in diet and health

The native mixed linkage β-glucan of cereals is classified as a soluble dietary fibre, with rheological properties generally similar to guar gum and other random coil polysaccharides. The ability of oat and barley products to attenuate postprandial glycemic and insulinemic response is related to content of (1→3)(1→4)-β-d-glucan (β-glucan) and viscosity. A role of viscosity of β-glucan has not been directly demonstrated for lowering of serum cholesterol levels, and not all studies report a statistically significant lowering. The wide range of effectiveness reported may partially be explained by the properties of the β-glucan in the diets used, as well as the dose.     

Enhanced physico-mechanical properties of polyester resin film using CaCO<Subscript>3</Subscript> filler

Bio-based CaCO₃ powder was synthesized via size reduction method from waste eggshells. The XRD analysis revealed that eggshell powder consists of CaCO₃ in calcite form. The inclusion level of CaCO₃ contents were varied of 5, 10, 15, 20 and 25 wt.% of prepared CaCO₃-polyester film. Effects of different proportions of prepared chicken eggshell and commercial CaCO₃ filler on the polyester resin composites films were compared by means of mechanical and physical test. It was found that the addition of CaCO₃ filler to the polyester films leads to improve the mechanical properties. The findings revealed that the best and optimum CaCO₃ filler content was 10 wt.% and among the prepared polyester films, eggshell CaCO₃-polyester films showed the best performance. The mechanical properties of CaCO₃-polyester films were measured in terms of tensile strength, elongation-at-break, tensile modulus, flexural strength and impact strength. For eggshell CaCO₃- polyester films, the maximum values of the aforementioned mechanical properties were 52.70 MPa, 4.63 %, 1868.70 MPa, 101.20 MPa and 8.40 kJ/m², respectively, whereas for commercial CaCO₃-polyester films those values were 48.12 MPa, 4.50 %, 1790.30 MPa, 97.50 MPa and 8.21 kJ/m², respectively. Further, water absorption of the composite films as a function of time had also been investigated at 10 wt.% filler content.     

Ladder-Structured Polysilsesquioxane/Al<Subscript>2</Subscript>O<Subscript>3</Subscript> Nanocomposites for Transparent Wear-Resistant Windows

As a protective layer for deformable displays, we synthesized ladder-type polysilsesquioxanes (LPSQs) containing cyclic epoxy as a curable unit. The mechanical properties after photo- and thermal-curing of LPSQs with a small amount of added Al₂O₃ nanoparticles were compared with those of the pure LPSQs. The prepared LPSQ-Al₂O₃ nanocomposites and the pure LPSQs exhibited comparable optical transparencies and thermal stabilities. In addition, the degree of conversion of the applied epoxy units in LPSQs and the resulting mechanical properties, as monitored by Fourier transform infrared spectroscopy and nanoindentation tests, indicated that the addition of nanoparticles to LPSQs moderately enhanced the epoxy conversion rate and remarkably improved the wear resistance, including hardness, after photo-/thermal-curing processes. The LPSQ-Al₂O₃ nanocomposites achieved higher wear resistance than epoxy-silica nanocomposites containing similar curable functional groups and reinforcing fillers (silica). The excellent mechanical properties of the LPSQ-Al₂O₃ nanocomposites could be attributed to three-dimensionally interconnected networks of organic-inorganic hybrid-type chemical structures in the LPSQ as well as additional reinforcement from amine-functionalized Al₂O₃ nanoparticles covalently interconnected with the LPSQ. We believe that the devised LPSQ-Al₂O₃ nanocomposites could serve effectively as a wear-resistant platform for deformable display windows.     

GA3对重瓣百合‘Carolina’生长及主要品质的影响

百合是花卉市场备受欢迎的球根花卉,花型美丽,花色淡雅,花香迷人,其中重瓣百合由于雄蕊退化、无花粉、花型优美、观赏期长等优点备受消费者青睐,本研究以东方型重瓣百合‘Carolina’为试材,采用6个不同浓度（50、100、200、400、600、800 mg/L）的GA₃对其进行叶面喷施处理,以清水为对照,通过测定其株高、茎粗及采后品质等指标,探讨GA₃对重瓣百合‘Carolina’生长及采后品质的影响。结果表明：栽培试验中400 mg/L GA₃对促进‘Carolina’株高、花苞长度、花朵开放率效果最好,分别比对照高10.40%、9.13%、17.78%,达到极显著差异;800 mg/L GA₃对‘Carolina’叶绿素相对含量的积累有促进作用;100 mg/L GA₃对‘Carolina’整株花期延长效果最佳,比对照长10.64%;在种球方面,800 mg/L GA₃对种球单个鲜重、总重量和平均根数的促进作用较好。瓶插期间,100 mg/L GA₃对延缓花枝鲜重、提高花苞开放率、延长单朵花期和整株花期效果最好;600 mg/L GA₃对延缓瓶插叶绿素相对含量和MDA的积累,提高SOD和POD酶活性作用最佳,达到极显著差异。综合比较来看,600 mg/L GA₃对重瓣百合‘Carolina’作用效果最佳,400 mg/L次之。     

Alpha‐tocopherol and β‐carotene in legume–grass mixtures as influenced by wilting,ensiling and type of silage additive

Effects of wilting, ensiling and type of additive on α‐tocopherol and β‐carotene contents in legume–grass mixtures were examined. Swards of birdsfoot trefoil + timothy (Bft + Ti), red clover + timothy (Rc + Ti) and red clover + meadow fescue (Rc + Mf) were harvested as a first regrowth in August 2005. Forage was wilted to a dry‐matter (DM) content of 273 g kg^?1 and ensiled without additive or with an inoculant or acid. Wilting decreased α‐tocopherol concentration by 30% in the Bft + Ti mixture (P = 0·015). Untreated Bft + Ti silage had higher α‐tocopherol content than red clover silages (56·9 vs. 34·2 mg kg^?1 DM; P = 0·015). The α‐tocopherol concentration of Bft + Ti forages increased during ensiling from 41·1 mg kg^?1 DM in wilted herbage to 56·9, 65·2 and 56·8 mg kg^?1 DM in untreated, inoculated and acid‐treated silage respectively (P = 0·015). The inoculant increased α‐tocopherol content in the red clover silages (50·1 vs. 34·2 mg kg^?1 DM; P = 0·015) compared with untreated red clover silages. Red clover mixtures had lower β‐carotene content than Bft + Ti (32·3 vs. 46·2 mg kg^?1 DM; P = 0·016), averaged over treatments. In conclusion, wilting had small effects but the use of bacterial inoculant as an additive and a Bft + Ti mixture increased α‐tocopherol concentration in the silage.     

Fabrication and characterization of nano Al<Subscript>2</Subscript>O<Subscript>3</Subscript> filled PVA:NH<Subscript>4</Subscript>SCN electrolyte nanofibers by electrospinning

Present paper reports a method of preparing polymer composite electrolyte nanofiber mat using polyvinyl alcohol (PVA), ammonium thiocynate (NH₄SCN) salt, and aluminium oxide (Al₂O₃) nano particles based on electrospinning technique. Two-stage process of preparation of nanofibers, namely, preparation of nano particles filled PVA electrolyte gel solution followed by its electrospinning has been used. The so obtained nanofibers have been characterized by XRD, DSC, SEM, and Conductivity measurements. XRD patterns affirm the formation of nanocomposite while SEM pictures reveal formation of fibers on a nano scale format (300–800 nm). Fibers of the electrolytes are seen to be thermally stable. Ionic conductivity of electrolyte fiber is seen to improve in the presence of nano filler at room temperature with a maximum at 5.31×10⁻³ Scm⁻¹ for 4 wt% filler concentration, which is comparable to that for corresponding dried gel electrolyte films.     

Draft Genome Sequencing of <Emphasis Type="Italic">Rhizoctonia solani</Emphasis> Anastomosis Group 3 (AG3- PT) Causing Stem Canker and Black Scurf of Potato

Rhizoctonia solani is a soil-borne basidiomycete fungus with a necrotrophic lifestyle being classified into fourteen reproductively incompatible anastomosis groups (AGs). AG3-PT (a potato subgroup) is associated with quantitative and qualitative yield losses through stem canker and black scurf in potato. Here we present the first draft sequence of the R. solani [AG3-PT] strain RS-20 with a G-C content of 48.3%. It consists of 11,431 total predicted protein coding regions including 181 tRNA and 31 rRNA coding genes. The initial pBLAST revealed more than 97% hits among AG groups where as only 1.7% of genes hit with other organisms. The R. solani genome is found to be dominated with tri mer repeats. The genome-wide evolutionary studies revealed the close association of AG3-PT with AG3. The draft sequence represents a helpful resource not only for understanding the core genes involved in pathogenecity but also evolution and adaptive behaviour within the R. solani species complex.     

Silencing of γ-gliadins by RNA interference (RNAi) in bread wheat

RNA silencing is a sequence-specific RNA degradation system that is conserved in a wide range of organisms. The elucidation of the mechanism of RNA silencing has stimulated its use as a reverse genetics tool, because RNA silencing strongly down-regulates the expression of the target gene in a sequence-specific manner. The major protein fraction of wheat grain is gluten which is largely responsible for the functional properties of dough. Gliadins contribute mainly to the extensibility and viscosity of gluten and dough, with the polymeric glutenins being responsible for elasticity. The aim of this work was therefore to silence the expression of specific γ-gliadins by RNA interference, to demonstrate the feasibility of systematically silencing specific groups of gluten proteins. The sequence of a γ-gliadin gene was used to construct the pghp8.1 plasmid. The hpRNA silencing fragment was designed on the basis of 169 base pairs (bp) in sense and antisense orientation with the sequence of the Ubi1 intron as spacer region between the repeats. Two lines of bread wheat were transformed by particle bombardment. Gliadins were extracted from 30 mg of flour, separated by acid-PAGE and determined by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Seven transgenic lines were obtained and all of them showed reduced levels of γ-gliadins. All seven transgenic plants were fully fertile and their grain morphology and seed weight were comparable to the control lines. MALDI-TOF MS showed that six peaks, present in the untransformed line, were missing in transgenic lines of the BW208 genotype whereas three peaks were missing in the BW2003 genotypes. The proportion of γ-gliadins was reduced, by about 55–80% in the BW208 lines and by about 33–43% in the BW2003 lines. The ELISA assay based on the R5 antibody showed reductions in total gliadins (μg/mg flour) in three of the BW208 lines and in one BW2003 line, but an increase in one BW208 line (C613).     

Cultivar and Environmental Effects on (1→3,1→4)-β-D-Glucan and Protein Content in Malting Barley

A low β-glucan and protein content is desirable for malting barley. In China high β-glucan content has been considered a major factor contributing to the inferior malting quality of local barleys. In this study 10 barley cultivars were planted in multi-location trials in the southern winter-barley zone to determine genotypic and environmental effects on β-glucan and protein content. There were highly significant differences in both β-glucan and protein content between the 10 barleys, the eight locations and the 2 planting years. The average β-glucan content over the 2 years for the 10 cultivars in the eight locations ranged from 3·91% for Gangpi 1 to 4·95% for Xiumei 3, and from 3·76% for Hangzhou to 4·75% for Taian in eight locations. Correspondingly, the protein contents of the 10 cultivars ranged from 11·37% for Yanyin 1 to 12·52% for ZAU, and of the eight locations from 9·5% for Hangzhou to 14·69% for Taian. Environmental factors contributed the largest component of the variation in both β-glucan and protein content. Five climatic factors, namely the total accumulated temperature, accumulated temperature to 25 °C and to 30 °C, precipitation and days with rain during seed development were included in a regression equation relating climatic factors and β-glucan content. In the regression equation relating climatic factors and protein content, two other factors, days from heading to maturity and accumulated temperature to 20 °C were included, in addition to the five climatic factors that significantly affected β-glucan content.     

A Novel α4/7-Conotoxin QuIA Selectively Inhibits α3β2 and α6/α3β4 Nicotinic Acetylcholine Receptor Subtypes with High Efficacy

α6β4 nAChR is expressed in the peripheral and central nervous systems and is associated with pain, addiction, and movement disorders. Natural α-conotoxins (α-CTxs) can effectively block different nAChR subtypes with higher efficacy and selectivity. However, the research on α6β4 nAChR is relatively poor, partly because of the lack of available target-specific α-CTxs. In this study, we synthesized a novel α-4/7 conotoxin QuIA that was found from Conus quercinus. We investigated the efficacy of this peptide to different nAChR subtypes using a two-electrode voltage-clamp technique. Remarkably, we found α-QuIA inhibited the neuronal α3β2 and α6/α3β4 nAChR subtypes with significantly high affinity (IC₅₀ was 55.7 nM and 90.68 nM, respectively), and did not block other nAChR subtypes even at a high concentration of 10 μM. In contrast, most α-CTxs have been determined so far to effectively block the α6/α3β4 nAChR subtype while also maintaining a similar higher efficacy against the closely related α6β2β3 and/or α3β4 subtypes, which are different from QuIA. In conclusion, α-QuIA is a novel α4/7-CTx, which has the potential to develop as an effective neuropharmacology tool to detect the function of α6β4 nAChR.     

景宁白茶系列品种家族新成员‘景白3号’

‘景白3号’是从景宁县惠明茶群体种自然变异单株选育的白化茶新品种。本文介绍了该品种的来源和发展过程,着重阐述了其品种的白化性状,特征、特性及品质特点。针对该品种的特点,开展繁殖、栽培管理技术研究和分析,更好地为今后产业化发展提供实践经验。     

Controlling the Properties of OPEFB/PLA Polymer Composite by Using Fe<Subscript>2</Subscript>O<Subscript>3</Subscript> for Microwave Applications

Microwave-absorptive polymer composite materials provide protection against interference to communication systems caused by microwave-inducing devices. Microwave-absorptive polymer composites were prepared from polylactic acid (PLA) biocomposite blended with oil palm empty fruit bunch (OPEFB) fiber and commercial Iron oxide (Fe₂O₃) as filler using the melt-blending method. The composites characterization was carried out using the scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses. The coefficient of reflection S₁₁ and coefficient of transmission S₂₁ of the composites for various Fe₂O₃ filler percentages were determined using a rectangular waveguide in connection with microwave vector network analyser (HP/Agilent model PNA N5227). These coefficients were then used to calculate microwave-absorption properties (in decibels). XRD analysis showed that increasing amounts of reinforced material (Fe₂O₃) reduces the crystallinity of the composites. SEM data indicated that Fe₂O₃ filler ratio increased in the composites, and adhesion to the cellulose fiber grew gradually until the highest percentage of filler was added. The complex relative permittivity and relative permeability were obtained within the broad frequency range of 8–12 GHz at room temperature for various percentages of filler and were measured by the transmission/reflection method using a vector network analyser. Fe₂O₃ embedment in OPEFB/PLA was observed to have resulted in enhancing the dielectric and magnetic properties. The values of permittivity and permeability increased with increasing Fe₂O₃ filler content. Theoretical simulation studied the relation between ε′ and ε″ of the relative complex permittivity in terms of Cole-Cole dispersion law. The result indicated that the processes of Debye relaxation in Fe₂O₃/OPEFB/PLA, the unique dielectric characteristics of Fe₂O₃ cannot be accounted for by both the Debye dipolar relaxation and natural resonance. Results further showed that the material transmission, reflection, and absorption properties could be controlled by changing the percentage of Fe₂O₃ filler in the composites.     

Load of Ag<Subscript>3</Subscript>PO<Subscript>4</Subscript> Particles on Sulfonated Polyphenylene Sulfide Superfine Fibre with High Visible-light Photocatalytic Activity

Ag₃PO₄ was loaded on sulfonated polyphenylene sulfide (SPPS) superfine fibre by a facile precipitation method. Both the structure and properties of the as-synthesized Ag₃PO₄/SPPS composites were characterized via XRD, SEM, EDS, XPS, FTIR, and UV-vis. The photocatalytic performance of Ag₃PO₄/SPPS composites was investigated via degradation of Methylene blue(MB) solution under visible light irradiation. The degradation results revealed that the photocatalytic activity of Ag₃PO₄/SPPS composites was greatly enhanced by the incorporation of Ag₃PO₄ with SPPS superfine fibre. For concentrations of AgNO₃ and Na₂HPO₄ solutions of 0.3 M and 0.06 M in the preparation process, the Ag₃PO₄/SPPS composite showed higher photocatalytic activity under visible light irradiation.     

Endo-β-1,4-xylanase inhibitors in leaves and roots of germinated maize

Extracts of both leaves and roots of germinated maize were found to contain endo–β–1,4–xylanase inhibitors, previously reported only from whole maize meal. The inhibitors seem to be of the xylanase inhibitor protein (XIP) type, since they inhibit endoxylanases of families 10 and 11 and also show some other characteristics similar to XIP inhibitors described in other cereals. Inhibitors from leaves and roots appeared to be similar. A novel property of the inhibitors described in this work is their unusual thermostability. The half-life of inhibitors at pH 4.5 and 100 °C is greater than 10 h. However, the inhibitors are less thermostable at higher pH levels. Because they did not inhibit a plant endoxylanase, the inhibitors may play a role in maize defense against phytopathogens.     

Evaluating the Mechanical Behavior of Basalt Fibers/Epoxy Composites Containing Surface-modified CaCO<Subscript>3</Subscript> Nanoparticles

Polymer matrix composites (PMCs) owing to their outstanding properties such as high strength, low weight, high thermal stability and chemical resistance are broadly utilized in various industries. In the present work, the influence of silanized CaCO₃ (S-CaCO₃) with 3-aminopropyltrimethoxysilane (3-APTMS) coupling agent at different values (0, 1, 3 and 5 wt.% with respect to the matrix) on the mechanical behavior of basalt fibers (BF)/epoxy composites was examined. BF-reinforced composites were fabricated via hand lay-up technique. Experimental results from three-point bending and tensile tests showed that with the dispersion of 3 wt.% S-CaCO₃, flexural strength, flexural modulus, tensile strength and tensile modulus enhanced by 28 %, 35 %, 20 % and 30 %, respectively. Microscopic examinations revealed that the development of the mechanical properties of fibrous composites with the incorporation of modified CaCO₃ was related to enhancement in the load transfer between the nanocomposite matrix and BF as well as enhanced mechanical properties of the matrix part.     

花生ω-3△~(15)-脂肪酸脱氧酶基因AhFAD3A的克隆及其表达

花生油中的α-亚麻酸含量在不同种质资源中存在着差异,与籽仁的不同发育时期也密切相关。本研究通过生物信息学分析并利用RACE的方法,从萌发的花生子叶中克隆了一个参与花生α-亚麻酸合成的ω-3△15-脂肪酸脱氢酶基因,命名为AhFAD3A。利用荧光定量PCR分别比较分析了AhFAD3A和Ah FAD8基因在花生不同组织、籽仁发育不同阶段、萌发过程中的表达特征,结果表明:AhFAD3A基因主要在花期的叶片组织和根部、籽仁形成期表达,在其它发育阶段该基因的表达量比较低,证实该基因的表达与花生籽仁中α-亚麻酸的形成呈正相关;AhFAD8基因在花生的整个生育阶段的绿色组织中表达、非光合组织中几乎不表达。以上研究结果为进一步确定AhFAD3A基因的功能、表达调控及其与花生籽仁中α-亚麻酸形成的关系提供了研究基础。