Preparation and application of an<Emphasis Type="Italic">s</Emphasis>-triazine-based novel<Emphasis Type="Italic">N</Emphasis>-halamine biocide for antimicrobial fibers

N-halamines serve as important antimicrobial agents. Development of this class of compounds has been shown to provide benefits especially from a biocidal point of view. A novels-triazine-basedN-heterocycle, dichloro-m-aminophenyl-hydantoinyl-s-triazine (DAPHT), which could be rendered antimicrobial through exposure to diluted chlorine bleach, was synthesized and characterized by¹H NMR,¹³C NMR, and FT-IR. A finishing method was used to apply theN-halamine precursor onto cotton fabric, and the optimum conditions for finishing were investigated. The DAPHT-treated cotton fabric had durable antimicrobial properties up to 50 standard washing cycles and was rechargeable under normal laundry/bleaching conditions. The antimicrobial efficacy against Gram-positive and Gram-negative bacteria was demonstrated.     

Launching the &quot;<Emphasis Type="Italic">Journal of Biomedical Discovery and Collaboration</Emphasis>&quot;

The Journal of Biomedical Discovery and Collaboration was created to provide, for the first time, a unified forum to consider all factors that affect scientific practice and scientific discovery – with an emphasis on the changing face of contemporary biomedical science. In this endeavor we are bringing together three different groups of scholars: a) laboratory investigators, who make the discoveries that are the currency of the scientific enterprise; b) computer science and informatics investigators, who devise tools for data analysis, mining, visualization and integration; and c) social scientists, including sociologists, historians, and philosophers, who study scientific practice, collaboration, and information needs. We will publish original research articles, case studies, focus pieces, reviews, and software articles. All articles in the Journal of Biomedical Discovery and Collaboration will be peer reviewed, published immediately upon acceptance, freely available online via open access, and archived in PubMed Central and other international full-text repositories.     

Structure and performance of<Emphasis Type="Italic">Bombyx mori</Emphasis> silk modified with nano-TiO<Subscript>2</Subscript> and chitosan

Bombyx mori (B. mori) silk was modified with the nano-TiO₂ and chitosan dispersion system by the crosslinking reactions of citric acid (CA) and maleic anhydride (MA). The average size of the nano-TiO₂ particles in the aqueous dispersion system was 36.7 nm. The scanning electron microscopy (SEM) micrographs showed that the nano-TiO₂ particles were spherical and homogeneously dispersed in the dispersion system, and the surface ofB. mori silk fiber treated with the nano-TiO₂ and chitosan dispersion system was rougher than that of the untreated one. X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) Spectrometry indicated that the crystallinity of theB. mori silk fiber increased after treatment. It was also found that the nano-TiO₂ and chitosan contributed to significantly enhance the mechanical properties including breaking strength, breaking elongation, initial modulus, rupture work, and elastic recovery property of theB. mori silk fiber. The wrinkle-resistant performance of the treatedB. mori silk fabrics was also greatly improved.     

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.     

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.     

基于RNA-seq技术开发中间偃麦草基因组特异分子标记

中间偃麦草(Thinopyrum intermedium,2n=6x=42,JJJSJSStSt或Ee Ee EbEbStSt)是小麦遗传改良的重要近缘植物,高抗锈病、白粉病等病害,耐逆性强。开发中间偃麦草基因组特异分子标记对于加快其优异基因向普通小麦中的转移和利用具有重要意义。为建立快速准确开发中间偃麦草基因组特异分子标记的新体系,首先利用RNA-seq技术对中间偃麦草及其基因组供体二倍体长穗偃麦草、百萨偃麦草、假鹅观草的苗期叶片进行转录组测序,然后根据测序结果设计EST-SSR引物,对普通小麦、中间偃麦草及其基因组供体材料进行DNA扩增分析,从中筛选鉴定中间偃麦草基因组特异标记。结果表明,在所合成的200对ESTSSR引物中,有75对引物(37.5%)在中间偃麦草、二倍体长穗偃麦草、百萨偃麦草和假鹅观草中具有特异扩增,引物多态率较高。说明利用RNA-seq技术开发EST-SSR引物可以高效地用于筛选中间偃麦草基因组特异分子标记,这一技术体系也可应用于其他作物及其近缘物种的特异分子标记开发。     

Polyacrylonitrile/electroconductive TiO<Subscript>2</Subscript> nanoparticles composite fibers <Emphasis Type="Italic">via</Emphasis> wet-spinning

For the first time, novel polyacrylonitrile (PAN)/electroconductive TiO₂ (EC-TiO₂) nanoparticles composite fibers have been successfully spun via wet-spinning. The composite fibers had uniform diameter and homogeneous surface. Moreover, at low content of EC-TiO₂ nanoparticles, the composite fibers realized a transition from an insulator to a conductor. This work has provided a simple and effective avenue for the production of PAN/EC-TiO₂ nanoparticles composite fibers that have great potential applications in the antistatic textiles.     

New Synthetic Glucosyl-Curcuminoids,and their <Superscript>1</Superscript>H and <Superscript>13</Superscript>C NMR Characterization,from <Emphasis Type="Italic">Curcuma longa</Emphasis> L.

Turmeric extracts, among which curcumin and bis-demethoxycurcumin, are by far known for their therapeutic activities. In this study we propose easy and low cost synthetic pathways in order to obtain glucosyl-curcuminoids, safe and water soluble potential drugs and dyes, which may be implied in different fields ranging from pharmacology to food chemistry. The complete ¹H and ¹³C NMR characterization of naturally occurring curcumin, bis-demethoxycurcumin and new synthetic glucosyl-curcuminoids is reported.     

Significance of LMW-GS and HMW-GS for Dough Extensibility: «Addition» versus «Incorporation» Protocols

Low molecular weight (LMW-GS) and high molecular weight glutenin subunits (HMW-GS) were added to a base flour using both «addition» and «incorporation» protocols. «Incorporation» of glutenin subunits into the glutenin network of the base flour was performed by partial (reversible) reduction and subsequent reoxidation of the glutenin network in the presence of the added glutenin subunits whereas, in the «addition» protocol, glutenin subunits were added without reduction/oxidation. The effects of both «addition» and «incorporation» of alkylated and unalkylated LMW-GS and HMW-GS on dough extension parameters maximum resistance (MR) and extensibility (EX) were compared and thoroughly discussed. HMW-GS and LMW-GS had totally different effects on dough extensibility. «Addition» of LMW-GS significantly decreased both MR and EX whereas HMW-GS caused a significant increase in MR. «Incorporation» of LMW-GS caused a decrease in MR whereas HMW-GS clearly increased MR. The similarity in effects obtained with «addition» and «incorporation» of glutenin subunits indicated that, even with «addition», glutenin subunits can be partially incorporated into the glutenin network in the presence of oxygen. Alkylated and unalkylated glutenin subunits had different effects. This was probably caused by the effect of free sulphydryl groups in unalkylated subunits (possibility of SS/SH exchanges and/or incorporation) and/or the effect induced by introduction of alkylated derived substituents. A protocol for «incorporation with excess KIO₃» was developed to exclude the possible effect of a lowering of the available oxidant concentration by oxidation of free sulphydryl groups in glutenin subunits. However, the use of high levels of oxidant in the «incorporation with excess KIO₃» protocol seems to overrule the effects of added glutenin subunits or may force glutenin subunits to incorporate differently from what can be observed under gentle oxidation conditions. Therefore, «incorporation with excess KIO₃» is not suitable for studying the effects of incorporation of glutenin subunits on dough extensibility.     

Two decades of monitoring irish populations of<Emphasis Type="Italic">Phytophthora infestans</Emphasis> for phenylamide resistance

Summary Between 1981 and 1998,Phytophthora infestans populations in 878 potato crops in Ireland were monitored for phenylamide resistance. The incidence of resistance was very high in 1981 following intensive use of metalaxyl for blight control from 1977 onwards. It decreased rapidly in the absence of phenylamide use between 1981 and 1984. Following the reintroduction of phenylamide based fungicides in 1985, there was a rapid increase in phenylamide resistance following the widespread curative use of these fungicides. From 1990 onwards there was greater adherence among growers to the use of phenylamides in accordance with an antiresistance strategy and resistance distribution again decreased. During the 18-year period of the study, resistance was always lower at the beginning of the season and increased as the season progressed. Following the reintroduction of the phenylamide based fungicides in 1985 there was a steady increase in phenylamide use up to 1986 followed by a continuous decrease in use up to 1990. Since then there has been a steady increase in phenylamide use. They are currently used on some 60% of crops in Ireland and are still providing acceptable levels of disease control.     

Longevity and growth of <Emphasis Type="Italic">Acacia tortilis</Emphasis>; insights from <Superscript>14</Superscript>C content and anatomy of wood

Background  

Acacia tortilis is a keystone species across arid ecosystems in Africa and the Middle East. Yet, its life-history, longevity and growth are poorly known, and consequently ongoing changes in tree populations cannot be managed in an appropriate manner. In other arid areas parenchymatic bands marking growth zones in the wood have made dendrochronological studies possible. The possibilities for using pre- and post-bomb ¹⁴C content in wood samples along with the presence of narrow marginal parenchymatic bands in the wood is therefore tested to gain further insight into the age, growth and growth conditions of A. tortilis in the hyper-arid Eastern Desert of Egypt.     

<Emphasis Type="Italic">In vitro</Emphasis> and <Emphasis Type="Italic">In vivo</Emphasis> Antioxidant Properties of Extracts from <Emphasis Type="Italic">Coptis chinensis</Emphasis> Inflorescence

The inflorescence of cultivated Coptis chinensis has been valued for tea production for many years in China. The antioxidant activities of C. chinensis inflorescence extracts prepared by various solvents were investigated by using several established in vitro systems: 2,2′-azinobis(3-ethylbenzthiazoline-6-sulphonic acid (ABTS), α,α-diphenyl-β-picrylhydrazyl (DPPH) and superoxide radical scavenging assays, reducing power assay, and ferrothiocyanate (FTC) and thiobarbituric acid (TBA) assays. The results showed that the 70% ethanol extract (EE) had the strongest antioxidant activity in vitro among the various extracts. Based on the in vitro results, EE was used to evaluate the antioxidant activity of C. chinensis inflorescence in vivo. The liver and kidney of intoxicated animals showed a significant decrease in superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) levels, while the malondialdehyde (MDA) level showed a significant increase. These changes were significantly reversed after treatment with EE and the standard vitamin E. Thus, the C. chinensis inflorescence may be a valuable natural source that can be applicable to food industries.     

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.     

Effect of phase transformation on physical and biological properties of PVA/CaFe<Subscript>2</Subscript>O<Subscript>4</Subscript> nanocomposite

The thermal treatment method was employed to achieve higher homogeneity of calcium ferrite (CaFe2O4) and Poly (vinyl alcohol) (PVA) nanocomposites. The influences of phase transformation on physical and biological properties of calcined specimens were investigated by various experimental techniques including X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), high resolution Field emission scanning electron microscope (FESEM) and Fourier transform infrared spectroscopy (FT-IR). Heat treatment was conducted at temperatures between 723 and 923 K, so that a phase transformation occurred from cubic to orthorhombic spinel structure at 923 K. The chemical analysis of the PVA/CaFe₂O₄ nanocomposite was performed by energy dispersion X-ray analysis (EDXA), demonstrated the PVA/CaFe₂O₄ nanocomposites contained the elements of C, Ca, Fe, and O. The formed nanocomposites exhibited ferromagnetic behaviors which were confirmed by using a vibrating sample magnetometer (VSM). The calcined specimens were carried out to an antimicrobial or antifungal test.     

Dithiosquarylium-based colorimetric sensors for Hg<Superscript>2+</Superscript>

A new Hg²⁺-selective chemosensor based on dithiosquarylium (DTSQ) dye was investigated. Among various metal cations tested, exclusively Hg²⁺ ion responses to irreversible color change of DTSQ-1, along with the Hg²⁺-triggered desulfurization of dithiosquarylium into its oxygen analogue squarylium (SQ) dye.     

Towards F<Subscript>1</Subscript> Hybrid Seed Potato Breeding

Compared to other major food crops, progress in potato yield as the result of breeding efforts is very slow. Genetic gains cannot be fixed in potato due to obligatory out-breeding. Overcoming inbreeding depression using diploid self-compatible clones should enable to replace the current method of out-breeding and clonal propagation into an F₁ hybrid system with true seeds. This idea is not new, but has long been considered unrealistic. Severe inbreeding depression and self-incompatibility in diploid germplasm have hitherto blocked the development of inbred lines. Back-crossing with a homozygous progenitor with the Sli gene which inhibits gametophytic self-incompatibility gave self-compatible offspring from elite material from our diploid breeding programme. We demonstrate that homozygous fixation of donor alleles is possible, with simultaneous improvement of tuber shape and tuber size grading of the recipient inbred line. These results provide proof of principle for F₁ hybrid potato breeding. The technical and economic perspectives are unprecedented as these will enable the development of new products with combinations of useful traits for all stakeholders in the potato chain. In addition, the hybrid’s seeds are produced by crossings, rendering the production and voluminous transport of potato seed tubers redundant as it can be replaced by direct sowing or the use of healthy mini-tubers, raised in greenhouses.     

Complete Genome Analysis of a PVY<Superscript>N-Wi</Superscript> Recombinant Isolate from <Emphasis Type="Italic">Solanum tuberosum</Emphasis> in China

The complete sequence of CF_YL21, a Potato virus Y (PVY) isolate from Solanum tuberosum in China, was determined to be 9718 nucleotides in length, excluding the 3′-terminal poly(A) tail. The viral genome had a single open reading frame of 9186 nucleotides encoding a polyprotein of 3061 amino acids. The polyprotein was predicted to be cleaved into ten functional proteins by three viral proteases. Sequence analyses indicated that CF_YL21 shared 97% nucleotide identity with Wilga5 (PVY^N-Wi), and two putative recombination signals were detected in the P1 and HC-Pro/P3 regions. Phylogenetic analyses, Bayesian Tip-association Significance (BaTS) test, and multiplex RT-PCR assay confirmed that the isolate had the similar molecular and genomic structure with PVY^N-Wi, a PVY strain formed by recombination between PVY^N and PVY^O. To our knowledge, this is the first report of the complete sequence structure of PVY^N-Wi strain from potato in China.     

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.     

The effect of floating vegetation on CH<Subscript>4</Subscript> and N<Subscript>2</Subscript>O emissions from subtropical paddy fields in China

Duckweed (Lemna minor), a floating macrophyte belonging to the Lemnaceae family, is commonly found in subtropical paddy fields. This plant rapidly takes up nutrients from water and forms dense floating mats over the water surface that may impact the biogeochemical processes and greenhouse gas production in paddy fields. In this study, we measured CH₄ and N₂O emissions from duckweed and non-duckweed plots in a subtropical paddy field in China during the period of rice growth using static chamber and gas chromatography methods. Our results showed that CH₄ emission rate ranged from 0.19 to 26.50 mg m^?2 h^?1 in the duckweed plots, and from 1.02 to 28.02 mg m^?2 h^?1 in the non-duckweed plots. The CH₄ emission peak occurred about 1 week earlier in the duckweed plots compared to the non-duckweed counterparts. The mean CH₄ emission rate in the duckweed plots (9.28 mg m^?2 h^?1) was significantly lower than that in non-duckweed plots (11.66 mg m^?2 h^?1) (p < 0.05), which might be attributed to the higher water and soil Eh in the former. N₂O emission rates varied between ?50.11 and 201.82 µg m^?2 h^?1, and between ?28.93 and 54.42 µg m^?2 h^?1 in the duckweed and non-duckweed plots, respectively. The average N₂O emission rate was significantly higher in the duckweed plots than in the non-duckweed plots (40.29 vs. 11.93 µg m^?2 h^?1) (p < 0.05). Our results suggest that the presence of duckweed will reduce CH₄ emission, but increase N₂O flux simultaneously. Taking into account the combined global warming potentials of CH₄ and N₂O, we found that growing duckweed could reduce the overall greenhouse effect of subtropical paddy fields by about 17 %.