Preparation and Performance of a Novel ZnO/TM/PET Composite Negative Ion Functional Fiber.

Using zinc oxide (ZnO), tourmaline (TM), and polyethylene terephthalate (PET) as main raw materials, a novel ZnO/TM/PET negative ion functional fiber was created. The rheological properties of a ZnO/TM/PET masterbatch were investigated; the morphology, XRD, and FT-IR of the fibers were observed; and the mechanical properties, thermal properties, and negative ion release properties of the new fiber were tested. The results showed that the average particle size of the ZnO/TM composite is nearly 365 nm, with an increase in negative ion emission efficiency by nearly 50% compared to the original TM. The apparent viscosity of fiber masterbatch decreases with the increase in the addition of the ZnO/TM composite, and the rheological properties of the PET fiber masterbatch are not significantly effected, still showing shear thinning characteristics when the amount of addition reaches 10%. The ZnO/TM composite disperses well in the interior and surface of the ZnO/TM/PET fiber matrix. The prepared ZnO/TM/PET fiber has excellent properties, such as fineness of 1.54 dtex, glass transition temperature of 122.4 °C, fracture strength of 3.31 cN/dtex, and negative ion release of 1640/cm3, which shows great industrialization potential.

The Electrical Conductivity and Mechanical Properties of Monolayer and Multilayer Nanofibre Membranes from Different Fillers: Calculated Based on Parallel Circuit.

Advanced research on improving the performance of conductive polymer composites is essential to exploring their potential in various applications. Thus, in this study, the electrical conductivity of multilayer nanofibre membranes composed of polyvinyl alcohol (PVA) with different electroconductive fillers content including zinc oxide (ZnO), multiwalled carbon nanotubes (MWNTs), and Ferro ferric oxide (Fe3O4), were produced via electrospinning. The tensile property and electrical conductivity of monolayer membranes were explored. The results showed that PVA with 2 wt.% MWNTs nanofibre membrane has the best conductivity (1.0 × 10-5 S/cm) and tensile strength (29.36 MPa) compared with other fillers. Meanwhile, the combination of multilayer membrane ZnO/Fe3O4/Fe3O4/MWNTs/ZnO showed the highest conductivity (1.39 × 10-5 S/cm). The parallel circuit and calculation of parallel resistance were attempted to demonstrate the conductive mechanism of multilayer membranes, which can predict the conductivity of other multilayer films. The production of multilayer composites that enhance electrical conductivity and improve conductive predictions was successfully explored.

Thermally Treated Berberine-Loaded SA/PVA/PEO Electrospun Microfiber Membranes for Antibacterial Wound Dressings.

This study aimed to develop a safe and advanced antibacterial material of electrospun microfiber membranes (MFMs) for wound dressings. Combinations of several materials were investigated; thermal treatment and electrospinning techniques were used to form the best quality of MFMs to suit its end applications. By comparing the fiber morphology, diameter changes, and fracture strength, the suitable ratio of raw materials and thermal treatment were obtained before and after adding Trition X-100 as a surfactant for MFMs of sodium alginate/polyvinyl alcohol/polyethylene oxide (SA/PVA/PEO). The electrospinning solution was mixed with berberine as an antibacterial substance; meanwhile, calcium chloride (CaCl2) was used as the crosslinking agent. The antibacterial properties, water dissolution resistance, water content, and fracture strength were thoroughly investigated. The results showed that the antibacterial rates of MFMs with different mass fractions of berberine (0, 3, and 5 wt.%) to Escherichia coli (E. coli) were 14.7, 92.9, and 97.2%, respectively. The moisture content and fracture strength of MFMs containing 5 wt.% berberine were 72.0% and 7.8 MPa, respectively. In addition, the produced MFMs embodied great water dissolution resistance. Berberine-loaded SA/PVA/PEO MFMs could potentially serve as an antibacterial wound dressing substrate with low cost and small side effects.

Cross-Dehydrogenative Alkynylation: A Powerful Tool for the Synthesis of Internal Alkynes.

Alkynes are among the most fundamentally important organic compounds and are widely used in synthetic chemistry, biochemistry, and materials science. Thus, the development of an efficient and sustainable method for the preparation of alkynes has been a central concern in organic synthesis. Cross-dehydrogenative coupling utilizing E-H and Z-H bonds in two different molecules can avoid the need for prefunctionalization of starting materials and has become one of the most straightforward methods for the construction of E-Z chemical bonds. This Review summarizes recent progress in the preparation of internal alkynes by cross-dehydrogenative coupling with terminal alkynes.

Microstructure and spectral characteristics of spectrum-fingerprint fiber with double luminous centers for anti-counterfeiting application.

Spectrum-fingerprint anti-counterfeiting fiber with double luminous centers was tentatively prepared using ${{\rm SrAl}_2}{{\rm O}_4}:{{\rm Eu}^{2 + }},{{\rm Dy}^{3 + }}$SrAl2O4:Eu2+,Dy3+, ${{\rm Sr}_2}{{\rm MgSi}_2}{{\rm O}_7}:{{\rm Eu}^{2 + }},{{\rm Dy}^{3 + }}$Sr2MgSi2O7:Eu2+,Dy3+, and PAN powder as main raw materials by wet spinning. The microstructure and spectral properties of the fiber were studied by means of scanning electron microscope (SEM), x-ray diffractometer (XRD), and a fluorescence spectrophotometer. The results showed that the two rare-Earth luminous materials were randomly dispersed on the interior and surface of the fiber. Due to the spinning process, the luminescent materials were agglomerated in fiber, and there were many voids in the fiber. Compared with pure rare-Earth luminous materials, the emission wavelength of the spectrum-fingerprint anti-counterfeiting fiber has no obvious shift, but the addition proportion and amount of two rare-Earth luminous materials have great influence on the spectral curve of the fiber. This fiber with two luminous centers maintains the basic characteristics of spectrum-fingerprint anti-counterfeiting fiber and is a new, to the best of our knowledge, type of anti-counterfeiting fiber with high anti-counterfeiting application potential.

Facile construction of a flexible and wearable electrode based on the hierarchical structure of RGO-coated cotton fabric with amorphous Co-Ni-B alloy.

As an emerging energy storage material, amorphous Co-Ni-B alloy was firstly introduced to construct the flexible supercapacitor electrode. To ensure the high electrochemical property, amorphous Co-Ni-B alloy and RGO sheets were combined to form the three-dimensional hierarchical structure on the surface of the cotton fabric, which was beneficial to enhance the electrochemical property. Notably, the preparation conditions of this amorphous Co-Ni-B/RGO/fabric electrode were facile and mild with room temperature and atmospheric pressure, thus avoiding serious damage to the textile fabric because of high temperature and harsh chemical reactions of most preparation methods. This flexible electrode exhibited an optimum specific capacitance of 313.9 F g-1 at 5 mV s-1 and good cycling stability with specific capacitance retention of 85.0% after 3000 cycles. Such special architecture bestowed this electrode with nice electrochemical property, in addition to great promising application in the supercapacitor field.

Catalytic sp3C-CN Bond Cleavage: Ni-Mediated Phosphorylation of Alkylnitriles.

A direct phosphorylation of the sp3C-CN bond catalyzed by a nickel catalyst is disclosed. A wide range of primary nitriles readily coupled with secondary phosphine oxides to produce the corresponding phosphorylated products in high yields. As a key step, this new method was applied to the synthesis of anticancer drug Combretastatin-A4, significantly shortening its synthetic path.

Direct C-OH/P(O)-H dehydration coupling forming phosphine oxides.

A t-BuONa-mediated C-OH/P(O)-H cross dehydration coupling to produce alkylphosphine oxides is developed. This reaction employed readily available alcohols and P(O)-H compounds as the starting materials, providing an efficient alternative method for constructing sp3 C-P bonds. A reasonable reaction path involving dehydration and subsequent regio-selective hydrophosphorylation of the resulting alkenes was proposed.

Transition-Metal-Catalyzed Three-Component Difunctionalizations of Alkenes.

Three-component reactions can directly convert three reactants into the desired products in one pot and thus greatly shorten the synthetic path. Recently, transition-metal catalysis has been applied in the difunctionalization of alkenes and remarkable progress has been achieved to facilitate the construction of a wide range of functional molecules with high atom- and step-economic efficiency. This Focus Review highlights recent advances in this field.

Efficient and selective hydrogenation of C-O bonds with a simple sodium formate catalyzed by nickel.

A Ni-catalyzed hydrogenation of C-O compounds with sodium formate is developed. Various esters, i.e. aryl, alkenyl, benzyl pivalates, and even the aryl ethers, were efficiently reduced with a loading of nickel catalysts down to 0.5 mol%. Reactive functional groups such as C-C double bonds, carbonyl, CN, MeS and halogen groups are tolerable. This reaction can be used for the modification of complex molecules and carried out at a large scale.

Silver-Free Direct Synthesis of Alkynylphosphine Oxides via spC-H/P(O)-H Dehydrogenative Coupling Catalyzed by Palladium.

A silver-free palladium-catalyzed dehydrogenative phosphorylation of terminal alkynes with hydrogen phosphine oxides has been developed. Both aromatic and aliphatic terminal alkynes including those bearing functional groups coupled readily with hydrogen phosphine oxides, producing the corresponding value-added alkynylphosphine oxides in good to excellent yields. This reaction could be easily conducted at gram scales (10 mmol) without any decrease of the reaction efficiency, showing highly potential synthetic value in organic synthesis. A plausible Pd(0)/Pd(II) mechanism is proposed.

t-BuOK-mediated reductive addition of P(O)-H compounds to terminal alkynes forming ß-arylphosphine oxides.

A novel and efficient t-BuOK-mediated reductive addition of P(O)-H compounds to terminal alkynes was developed. A variety of ß-arylphosphine oxides including the valuable ß-heteroarylphosphine oxides were produced in moderate to high yields under mild reaction conditions. This reaction may proceed via a tandem process involving regio-selective double addition and subsequent transfer hydrogenation.

Dehydrogenative coupling involving P(O)-H bonds: a powerful way for the preparation of phosphoryl compounds.

Because of the unique properties and wide applications, continuing efforts have been devoted to developing simpler and cleaner methods for the synthesis of organophosphorus compounds. Recently, transition metal-catalysed dehydrogenative coupling has been emerging as one of the powerful methodologies for constructing chemical bonds. Herein, we highlight the recent progress in the preparation of organophosphorus compounds via transition metal-catalysed dehydrogenative couplings of P(O)H compounds with Z-H compounds.

Nickel-catalysed P-C bond formation via P-H/C-CN cross coupling reactions.

Nickel-catalysed P-H/C-CN cross coupling reactions take place efficiently under mild reaction conditions affording the corresponding sp(2)C-P bonds. This transformation provides a convenient method for the preparation of arylphosphines and arylphosphine oxides from the readily available P-H compounds and arylnitriles.

Biological activity of the tzs gene of nopaline Agrobacterium tumefaciens GV3101 in plant regeneration and genetic transformation.

Agrobacterium tumefaciens has been widely used in plant genetic transformation. Hormone-encoding genes residing in the T-DNA region have been removed, resulting in disarmed Agrobacterium strains that are used in various transformation experiments. Nopaline Agrobacterium strains, however, carry another hormone gene, trans-zeatin synthesizing (tzs), that codes for trans-zeatin in the virulence region of the tumor-inducing plasmids. We investigated the activity and function of the tzs gene of a nopaline Agrobacterium sp. strain GV3101 in plant in vitro regeneration. Leaf explants of tobacco and Nicotiana benthamiana co-cultured with strain GV3101 exhibited active shoot regeneration in media without added plant growth regulators. On medium without plant growth regulators, transgenic shoots were also induced from explants co-cultured with GV3101 containing a binary vector. Enzyme-linked immunosorbent assay showed that cell-free extracts of Agrobacterium sp. strain GV3101 culture contained the trans-zeatin at 860 ng/liter. Polymerase chain reaction using tzs-specific primers showed that the tzs gene was present in strain GV3101 but not in other Agrobacterium strains. The study showed that the tzs gene in GV3101 was actively expressed, and that trans-zeatin produced in the Agrobacterium strain can promote plant shoot regeneration.

Simultaneous determination of catechin, epicatechin and epicatechin gallate in rat plasma by LC-ESI-MS/MS for pharmacokinetic studies after oral administration of Cynomorium songaricum extract.

A rapid and valid method was developed for simultaneous determination catechin, epicatechin and epicatechin gallate in rat plasmas using scopoletin (103 ng mL(-1)) as an internal standard (IS). The separation was performed on Eclipse plus C18 column (100 mm × 4.6 mm, 1.8 µm) at a flow rate of 0.3 mL min(-1), and acetonitrile-0.1% formic acid was used as mobile phase. The recoveries of three analytes and IS were more than 78.9%. The lower limits of quantitation (LLOQ) in rat plasma were 2.14, 2.38 and 2.08 ng mL(-1) respectively for catechin, epicatechin and epicatechin gallate. Intra-day and inter-day precisions were within 12%. The accuracies were more than 85%. After single oral administration of 15.25 g kg(-1) Cynomorium songaricum extract, C(max) of catechin, epicatechin and epicatechin gallate in rat plasma were respectively 86.69±38.65, 32.57±15.00 and 36.93±12.62 ng mL(-1) while T(max) values were respectively 0.15±0.09, 0.20±0.10 and 0.20±0.13 h. The results demonstrated that the present LC-MS/MS method was sensitive enough for pharmacokinetic study of catichins following oral administration of C. songaricum extract.

Metschnikowia sinensis sp. nov., Metschnikowia zizyphicola sp. nov. and Metschnikowia shanxiensis sp. nov., novel yeast species from jujube fruit.

Eight yeast strains were isolated from jujube fruit surfaces collected in Shanxi and Shandong Provinces, China. All eight strains produced needle-shaped ascospores under suitable conditions. Three separate groups, representing three novel species in the genus Metschnikowia, were recognized by sequence comparisons of the 26S rDNA D1/D2 domain and internal transcribed spacer (ITS) region. The names Metschnikowia sinensis sp. nov. (type strain XY103(T)=AS 2.3110(T)=CBS 10357(T)), Metschnikowia zizyphicola sp. nov. (type strain XY201(T)=AS 2.3111(T)=CBS 10358(T)) and Metschnikowia shanxiensis sp. nov. (type strain XY801(T)=AS 2.3112(T)=CBS 10359(T)) are proposed for the three novel species. Phylogenetic analysis of the 26S rDNA D1/D2 domain sequence showed that these three novel species are clustered in a clade together with the previously described species Metschnikowia fructicola, Metschnikowia andauensis, Metschnikowia pulcherrima and Metschnikowia chrysoperlae.

[Study on dynamics of tannin in different growth phase of Cynomorium songaricum].

Potassium permanganate titration and complexometry were used to determine the content of tannin in different growth phase of wild and cultivated Cynomorium songaricum Rupr. The result showed that the content appeared regularly changing and the content in coming-up phase was higher than other phases. The quality in this phase would be better if the tannin was regarded as one of the effective components. The result might provide science foundation for the quality control of Herb Cynomorii.

Screening of a RAPD marker tightly linked to Co gene in apple and the SCAR marker conversion.

A DNA marker linked to the columnar gene (Co) in apple (Malus domestica) was explored based on the population of 105 progenies of 'Spur Fuji' x 'Telamon' by bulk segregant analysis (BSA) and Random Amplified Polymorphic DNA (RAPD) technique. A total of 300 random primers were screened and a RAPD marker (S1142(682)) closely linked to Co gene (2.86 cM) was identified and then sequenced. Four specific PCR primers (two forward primers and two reverse primers) were designed,and the products of SCAR-PCR indicated that all the four pairs of primers could amplify polymorphic bands between columnar and non-columnar traits, so any of them could serve as the specific SCAR primers. One pair of these specific primers was chosen to amplify each individual in the population, and the result showed that the co-segregation pattern of this SCAR marker and Co gene was the same as that of the RAPD marker. Furthermore, it was found that the nucleotide sequence of the RAPD marker fragment contained an open reading frame (ORF) that could encode 68 deduced amino acid residues at the position of +45 - +251.