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The impact damage evolution of thermally sprayed WC-Ni coatings was studied under 1-8000 impacts at a fixed load of 10 kN order. With increasing impact number, the accumulative damages of coatings evolve by in-sequence occurrence of WC spallation, coating cracking, and mixed coating/interface cracking accompanied with crack length and width growing. To comprehensively evaluate the coated component performance by observed accumulative damages as the failure criteria, a critical impact number Nc with critical load Lc is proposed for the onsets of different cracking features. The impact resistance is quantified, by Nc(Lcc) for onset of the coating cracking, and Nc(Lcm) for the mixed coating/interface cracking. A subclassification is identified as Nc(Lcm1) and Nc(Lcm2), respectively, for sequential occurrence of the isolated interface cracking and the propagated interface cracking of the penetrated from the coating surface. As the coating thickness is increased from 50 to 200 μm, the impact resistance under a load of 11.1 kN is correspondingly improved with Nc(Lcc) prolonged from 3000 to 4500, and Nc(Lcm1) from 4500 to 5000. In particular, Nc(Lcm2) is 6000 for the 50 μm coating, but no Nc(Lcm2) failure for the 200 μm coating up to 8000 impacts. The impact stress field analysis reveals reduced amplitudes of cyclic surface tensile stress and interface shear stress for the thicker coating, together with the interface shear stress shifting from a tensile-compressive alternating mode to a monotonous tensile one. The impact resistance of coated components under repetitive impacts is interpreted on thermodynamics where the thicker coatings mitigate impact mechanical energy dissipation of plastic strain energy in both coating and steel substrate, and accommodate larger reversible elastic strain energy during the periodic loading-unloading of impact cycles. [ABSTRACT FROM AUTHOR]

The impact resistance of coating/substrate systems is still lacking comprehensive understanding, especially for the thermal spray of wear-resistant coatings for coated components in potential applications with heavy-load impact service condition. The impact responses of a thermal spray WC-Ni coating/steel substrate were studied systematically by varying the coating thicknesses from 50 to 300 μm under an impact load of 1–10 kN. Besides conventionally employed crater depth/volume for impact evaluation, a critical impact load is identified to quantify the impact resistance with cracking. Considering the observed cracking modes, two critical loads of Lcc and Lcm have been defined corresponding to the cohesive failure of cracking in coatings and the mixed cohesive–adhesive failure including interface cracking, respectively. Increasing the coating thickness up to 200 μm raised the critical load Lcm from 7.4 to 11.1 kN, followed by a drop to 7.4 kN of Lcc at 300 μm. To reveal the influence of coating thickness, a major surface integrity parameter is proposed as the coating deformation in proportion to the total value of coating/substrate system in correlation to the impact resistance. The dependence of impact resistance on coating thickness is interpreted through the surface integrity changes by the thermodynamic mechanism of effective energy input and dissipation into the coating/substrate system from the external impact load. [ABSTRACT FROM AUTHOR]

Wear-yet impact-resistant demand is a big challenge for coated components under heavy-load service condition. To solve this high-performance manufacturing problem, a new strategy of design for manufacturing (DFM) with integrated design and processing is developed to incorporate processing effect on final performance via the pivot role of surface integrity. An impact performance model and the impact tester are constructed for a component with coated flat block/bulk cylinder mates for potential application in hydraulic machinery. A WC-12Ni/Ni60A two-layer coating on 17-4PH martensitic steel substrate is designed with thermal spray process. Impact crater depth, surface hardening, and residual stresses are identified as major surface integrity parameters determining wear/impact performance by the modeling with testing. The design parameters of geometry, material, and structure are quantitatively linked to the final performance by a process signature (PS) correlative analysis on the identified surface integrity to internal material loading of plastic/elastic strain energies. The PS correlation posts coating thickness as a high-sensitivity parameter for design, facilitating a buffering effect of reduced peak stresses among the coating-substrate system. The DFM optimization is understood by irreversible thermodynamics as reducing energy dissipation of the internal material loading from the external impact loads. The manufacturing inverse problem is thus solved by material-oriented regularization (MOR) on the homologous PS correlations integrating the design and processing phases. The manufactured component, with optimal Ni60A interlayer thickness of 75-100 µm at a top WC-12Ni coating of 200 µm, achieves a desired performance of up to 6000 impacts under a nominal load of 15 kN. [ABSTRACT FROM AUTHOR]

The results of the simulation and experimental study of the high-power ion beam generation in an ion diode with a passive anode (accelerating voltage of 250–300 kV, pulse duration of 150 ns, beam energy per pulse of ≈50 J) are presented. The studies were carried out on a diode with a stainless steel anode during operation in the mode of double pulses of different polarities and plasma formation at explosive emission of electrons during the first pulse. It is found that a diode with a metal anode generates nitrogen ions, and the content of heavier ions of the anode material (Fe+) is insignificant. It is shown that the suppression of the heavy ion generation in an ion diode with a passive anode is caused by a higher expansion rate of the light-ion component of the anode plasma. The penetration depth of the electric field into the anode plasma is less than the layer thickness of lighter ions at its emission boundary; therefore, only light ions are emitted from the anode plasma and accelerated in the anode–cathode gap. The suppression of the heavy ion generation in a diode with a passive anode is a positive effect that provides an increase in the ion current when operating in the current limitation mode by the volume charge and a decrease in the density of impurity ions. [ABSTRACT FROM AUTHOR]

Background: The gut microbiota is an integral part of the host and plays an important role in both growth and development of host. The research on intestinal microbiota of Nibea albiflora and its relationship to fish disease have not been reported before. This study aimed to investigate the composition and differences of gut bacteria between healthy and diseased Nibea albiflora. Methods: The intestines were collected from forty fish (twenty healthy fish and twenty diseased). Total DNA was extracted and then amplified by nested PCR. The PCR product was subjected to the DGGE test and performed at the IlluminaMiseq sequencing. Result: The obtained results of both utilized techniques (DGGE and Next generation sequencing) showed that dominant bacteria could be grouped into four populations and the composition of intestinal bacteria differed significantly between healthy (NH) and diseased (ND) Nibea albiflora. NH has higher levels of γ-Proteobacteria and Firmicutes and with 46.91% Photobacterium supplied the dominant genus in NH. Fusobacteria and Bacteroidetes were higher in ND and Cetobacterium occupied 62.31% and was the dominant genus in ND. More probiotics were detected in NH, such as Lactobacillus, Brevibacillus, Enterococcus and Lactococcus (occupying 1.77% -19.76%), while less than 0.2% were detected for both in ND. More genera that belonged to Vibrionaceae, such as Enterovibrio (9.27%) and Vibrio (2.17%), were detected in ND and their abundances in NH were 0.79% and 0.03%, respectively. [ABSTRACT FROM AUTHOR]

The results of time-of-flight diagnostics of the composition of high-intensity pulsed ion beams are presented. The experiments were performed on a diode of focusing and flat geometry, in the mode of self-magnetic insulation of electrons (accelerating voltage 250–300 kV, pulse duration 120 ns, ion current density 20–300 A/cm2), and a focusing diode in an external magnetic insulation mode (300 kV, 80 ns, 100–200 A/cm2). A delay in the registration of protons by 40–50 ns (on the drift path 14–16 cm) was found in the absence of a delay in the registration of heavy ions. It has been shown that this delay can be related to the deceleration of light ions during the transport from the diode to a collimated Faraday cup. This effect of spatial compression of the ion beam in the direction of the drift increases its pulse power but complicates the time-of-flight diagnostics of its composition. [ABSTRACT FROM AUTHOR]

Aim: To investigate nurses' knowledge, attitudes and practices related to physical restraint in tertiary hospitals and identify the factors that influence physical restraint use. Background: Physical restraint is used to maintain patient safety. Nurses play an important role in the restraint process. It is important to identify their understanding, feelings and approach regarding the use of physical restraint. Introduction: Physical restraint is widely practiced in hospitals in China. However, it results in a range of serious negative consequences. This article provides a clear description of nurses' knowledge, attitudes and practices related to physical restraint. Methods: A cross‐sectional survey was conducted. The participants were asked to complete a questionnaire examining their knowledge, attitudes and practices related to physical restraint use. A total of 200 questionnaires were distributed in four tertiary hospitals in Hubei Province, China between August and October 2014. Results: The nurses' responses indicated a good level of knowledge regarding physical restraint use. However, they held some misconceptions. The nurses' attitudes towards physical restraint tended to be neutral. The nurses were well experienced in the use of physical restraint. Nurses who had received on‐the‐job training performed better than those who had received no training related to knowledge and practices regarding physical restraint use. Conclusions and implication for nursing/health policy: In‐service training is highly recommended for nursing managers to improve nurses' physical restraint related knowledge and practices. Regulations regarding the use of restraints should be established as soon as possible by healthcare administration system. Implications for nursing: Nurses should be open to evaluate and improve their views and attitudes regarding effective physical restraint use via multidimensional interventions. [ABSTRACT FROM AUTHOR]

Oxidation or decomposition of thermally sprayed coatings during deposition may noticably impair the coating features and characteristics, i.e. the surface integrity of coated components, including coating porosity, phase, microhardness, elastic modulus and toughness, etc., having a profound influence on the final performance of components. Further degradations along with enhanced oxidation of the coatings were observed for an off-angle spraying scheme in industrial practice, where inconsistent results were previously reported for spray angle-dependent degradation of various thermal spray coatings, with the mechanism not being fully understood with the less controlled surface integrity. An improved off-angle HVOF thermal spray has been developed for cemented carbide coatings, using pretreated WC-Ni feedstock powders covered with a nanoscale capsulizing nickel layer. A comprehensive study on the formation of multiple surface integrity parameters and the correlative interactions between them is thus facilitated with controllable surface integrity generation using the capsulized powders. Decarburization is mainly attributed to the exposure of pristine WC grains causing enhanced porosity in inter-splats regions, and then microhardness depends mainly on porosity and partly on phase composition, while the elastic modulus depends on intra-splats cohesion and the indentation fracture toughness on inter-splats cohesion, respectively. Abrasive wear from mild to severe regime transition could be interpreted by the inter-splats and intra-splats cohesion correlation. It has been demonstrated by the improved off-angle thermal spray that a manufacturing process could be designed and optimized on the identified unique correlations between the processes, surface integrity and the final performance. [ABSTRACT FROM AUTHOR]

The focused high-intensity pulsed ion beam (HIPIB) of 100 ns order pulse is generated with respect to its spatial stability in two types of magnetically insulated ion diodes (MIDs) with geometrical focusing configuration using the passive anode, i.e., insulation of electrons with an external magnetic-field and a self-magnetic field, respectively. Anode plasma formation for the ion beam generation is based on different processes in the two types of MIDs, as the surface breakdown on the polymer-coated anode operated in the unipolar pulse mode for the external-magnetic field MID and the explosive electron emission on the graphite anode in the bipolar-pulse mode for the selfmagnetic field MID. Typical energy density per pulse is in the range of 3-6 J/cm², at an accelerating voltage of 200-300 kV with a pulse duration of 120-150 ns. The spatial deviations of the HIPIB is evaluated by measuring the energy density distribution by using an infrared diagnostic method considering neutralizing during the ion beam propagation to the focal plane with a spatial resolution of 1 mm. The ion beam deviation is about ±1.5mm for the external-magnetic field MID and ±2.5mm for the self-magnetic field MID, leading to a fluctuation in the energy density of 1%-12%, and 9%-27% within a 10mm range at the focal point, respectively. It is revealed that the displacement of different parts of a beam spot occurs nonsynchronously, mainly attributable to the intrinsic diode processes of plasma generation and expansion, and ion beam extraction from the anode-cathode gap, while the influence of magnetic field in the transportation region is negligible. The ion beam spatial deviation has a major influence on the shot-to-shot stability of ion beam, and it is suggested that the stability can be enhanced via diode process improvement. [ABSTRACT FROM AUTHOR]

High-performance manufacturing is difficult to perform using conventional materials removal processes since a surface integrity demand for high-performance components is strongly restricted by intrinsic interactions between the geometrical feature of components and the physical and chemical characteristics of the base material. Surface modification techniques based on known processing loads, including mechanical, thermomechani-cal, and thermochemical loads, are utilized for manufacturing the Fe-Cr-Ni austenitic stainless steel components. The geometrical feature and the physical and chemical characteristics as well as the controllable interactions between them are identified in the surface integrity of the surface-modified components by creating new surface layers coupled with base material. The effective surface stares control, including surface morphology, microhardness, and residua! stress, leads to surface integrity improvement by reducing geometrical, physical, and chemical constraints from base materials, otherwise unobtainable merely using conventional materials removal manufacturing. The fatigue life of the surface-modified components is significantly increased due to the improved surface integrity. It is proposed that high surface integrity possesses a pivotal role between the functional properties of components and their geometrical feature and materials characteristics for the high-performance manufacturing. [ABSTRACT FROM AUTHOR]

High-intensity pulsed ion beam (HIPIB) with ion current density above Child-Langmuir limit is achieved by extracting ion beam from anode plasma of ion diodes with suppressing electron flow under magnetic field insulation. It was theoretically estimated that with increasing the magnetic field, a maximal value of ion current density may reach nearly 3 times that of Child-Langmuir limit in a non-relativistic mode and close to 6 times in a highly relativistic mode. In this study, the behavior of ion beam enhancement by magnetic insulation is systematically investigated in three types of magnetically insulated ion diodes (MIDs) with passive anode, taking into account the anode plasma generation process on the anode surface. A maximal enhancement factor higher than 6 over the Child-Langmuir limit can be obtained in the non-relativistic mode with accelerating voltage of 200-300 kV. The MIDs differ in two anode plasma formation mechanisms, i.e., surface flashover of a dielectric coating on the anode and explosive emission of electrons from the anode, as well as in two insulation modes of external-magnetic field and self-magnetic field with either non-closed or closed drift of electrons in the anode-cathode (A-K) gap, respectively. Combined with ion current density measurement, energy density characterization is employed to resolve the spatial distribution of energy density before focusing for exploring the ion beam generation process. Consistent results are obtained on three types of MIDs concerning control of neutralizing electron flows for the space charge of ions where the high ion beam enhancement is determined by effective electron neutralization in the A-K gap, while the HIPIB composition of different ion species downstream from the diode may be considerably affected by the ion beam neutralization during propagation. [ABSTRACT FROM AUTHOR]

Lavender flower essential oil had been used for a variety of therapeutic and cosmetic purposes. Previous studies mainly focused on essential oil composition and extraction methods, ignoring the factors that affected the production of essential oils, such as the floret number. This study aims to get a deep insight into the mechanism of floret number differences. Hormone analysis showed that there was a positive correlation between abscisic acid (ABA) content and the number of florets, while indole-3-acetic acid (IAA) was negatively correlated with floret numbers. RNA-Seq results showed that 1 035 differentially expressed genes (DEG) can be identified, of which 19 genes were significantly enriched in the carotenoid biosynthesis pathway. Common network analysis showed that the expression of the key genes of ABA pathway metabolism was negatively related to the DEG of IAA, especial IAA18. Exogenous IAA significantly inhibited the number of lavender florets and affected the expression of ABA metabolism genes. The results might be useful for a better understanding of the molecular mechanism of floret number differences. [ABSTRACT FROM AUTHOR]

This study determined the tuf gene sequence of the phytoplasma specific to paulownia witches’-broom from Nanyang, China (hereby designated PaWB-Ny). The PaWB-Ny tuf gene was 1185 nucleotides in length and confirmed that the phytoplasma belongs to subgroup 16SrI-D of aster yellows. Three characteristic GTP-binding protein motifs were identified based on the peptide deduced from the tuf gene sequence. Results suggested that the elongation factor EF-Tu was localized in the cytoplasm and lacked hydrophobic transmembrane domains. Antibodies against PaWB-Ny EF-Tu were prepared by rabbit immunization with glutathione-S-transferase (GST)-tagged EF-Tu fusion protein expressed in Escherichia coli. EF-Tu exhibited a molecular weight of ∼43 kDa and was detected in PaWB-infected paulownia plants by western blot analysis. Indirect enzyme-linked immunosorbent assays (ELISA) and dot blotting analyses were performed with freezing and thawing treatments during antigen preparation. Dilution of extracts to an appropriate scale significantly reduced non-specific reactions. The resultant PaWB EF-Tu antibody reacted with antigens from plants infected with periwinkle virescence and chinaberry tree witches’-broom phytoplasmas, but not those infected with jujube witches’-broom or bishopwood witches’-broom phytoplasma. The EF-Tu was characteristically localized within the phytoplasmal cytoplasm of infected plant phloem tissues. [ABSTRACT FROM AUTHOR]

A novel shock processing by high-intensity pulsed ion beam (HIP/B) is developed, referred to as ion beam shock processing (IBSP), for surface processing of components with high surface integrity. The IBSP utilizes effectively coupled thermal-dynamic effects of HIPIB irradiation onto materials, characterized by ultrafast surface remelting and solidification, and controlled ablation. As a result, using the IBSP treatment with HIP/B parameters with an ion energy of 200-400 keV and an ion current density of 50-400 A/cm² with a pulse width of 75 ns, i.e., a power density of 107-108 W/cm², hardening extending to tens and hundreds of micrometers in depth is achieved on pure Cu and 316L austenitic stainless steel, which is comparable to that of laser shock processing at about two orders higher power density, usually no less than 109-1010 W/cm². Significant improvements in the overall performance including wear and corrosion resistance, fatigue, and creep properties are found for IBSP treated pure Cu and 316L stainless steel, attributable to the formation of nonequilibrium microstructures into different depths of the processed materials, e.g., amorphous and/or nanocrystalline structure in the heat-affected zone, and high-density defects in the deeper regions with residual compressive stresses caused by shock wave propagation into substrate in which the former is not obtainable in conventional shock processing. Furthermore, purified and polished surfaces free of cracks can be obtained simultaneously under HIPIB irradiation, composing the completeness for effectively enhancing the surface integrity of the processed materials. The coupled thermal-dynamic effects of IBSP assure surface processing of high surface integrity for components, with improved physical and chemical properties and modified surface topography. [ABSTRACT FROM AUTHOR]

Thirteen polymorphic microsatellite markers were used to study the genetic variation of Ptychidio jordani sampled from the three sites of Liuzhou, Guiping and Yunan in the Pearl River Basin with the help of local fishers. Allele numbers ranged from 2 to 19 and fragment sizes ranged from 108 to 288. Average polymorphism information content (PIC), average observed heterozygosity (Ho) and average expected heterozygosity (He) were 0.439917, 0.4147 and 0.4986, respectively, which indicate a comparatively high level of genetic diversity. The coefficient of genetic differentiation ( Gst) between the two sub-populations ranged from 0.0074 to 0.0156, which shows little differentiation between sub-populations.amova analysis also offered evidence of weak differentiation with 0.53% variation between sub-populations, 99.47% variation within sub-populations and the Fst = 0.00531. The morphological variation among geographic sub-populations might result from different habitats. The correlation between genotype and morphological characters was analyzed and a significant correlation found between the genotype of microsatellite locus Hlj038 and the ratio of body depth and body length. The results suggest a possible linkage between this locus and these morphological characters. [ABSTRACT FROM AUTHOR]

Initial anode plasma formation in a magnetically insulated ion diode (MID) of bipolar-pulse mode with self-magnetic field is studied for high-intensity pulsed ion beam generation in TEMP-6-type apparatus [X. P. Zhu, M. K. Lei, and T. C. Ma, Rev. Sci. Instrum. 73, 1728 (2002)]. The field emission characteristics on graphite anode, the self-magnetic field, the perveance, and the impedance of the MID are obtained by analysis of the time-dependent diode voltage-current characteristics during the initial negative pulse stage of 100 ns, with peak values of 250 kV and 30 kA, respectively. The anode plasma is initiated by explosive emission on the anode due to a significant field enhancement effect up to four orders of magnitude, and the subsequent merging and movement of the anode plasma are affected by the superimposing space-charge effect and magnetic insulation of the self-magnetic field. The formation process of the initial anode plasma in the MID corresponds to the diode response under the initial negative pulse of the bipolar pulse. [ABSTRACT FROM AUTHOR]

Turnip mosaic virus (TuMV; genus Potyvirus, family Potyviridae) causes great losses to cruciferous crop production worldwide. The 3′-terminal genomic sequences of eight TuMV isolates from eastern China were compared with those of 74 other Chinese TuMV isolates of known host origin in the GenBank and isolated during the past 25 years. The reported sequences of the eight TuMV isolates are 1125 or 1126-nucleotides (nt) long excluding the poly(A) tail. They all contain one partial open reading frame of 912 nt, encoding 304 amino acids, followed by a stop codon and a non-translated region of 209–210 nt. Results of phylogenetic analyses showed that Chinese TuMV isolates clustered into three groups: basal-BR, Asian-BR and world-B. The ratios of non-synonymous and synonymous substitutions and results of amino acid alignment provided evidence for purifying or negative selection in TuMV populations of China. [ABSTRACT FROM AUTHOR]

Generation of high-intensity pulsed ion beam (HIPIB) has been studied experimentally using polyethylene as the anode polymer in magnetically insulated ion diodes (MIDs) with an external magnetic field. The HIPIB is extracted from the anode plasma produced during the surface discharging process on polyethylene under the electrical and magnetic fields in MIDs, i.e., high-voltage surface breakdown (flashover) with bombardments by electrons. The surface morphology and the microstructure of the anode polymer are characterized using scanning electron microscopy and differential scanning calorimetry, respectively. The surface roughening of the anode polymer results from the explosive release of trapped gases or newly formed gases under the high-voltage discharging, leaving fractured surfaces with bubble formation. The polyethylene in the surface layer degrades into low-molecular-weight polymers such as polyethylene wax and paraffin under the discharging process. Both the surface roughness and the fraction of low molecular polymers apparently increase as the discharging times are prolonged for multipulse HIPIB generation. The changes in the surface morphology and the composition of anode polymer lead to a noticeable decrease in the output of ion beam intensity, i.e., ion current density and diode voltage, accompanied with an increase in instability of the parameters with the prolonged discharge times. The diode voltage (or surface breakdown voltage of polymer) mainly depends on the surface morphology (or roughness) of anode polymers, and the ion current density on the composition of anode polymers, which account for the two stages of anode polymer degradation observed experimentally, i.e., stage I which has a steady decrease of the two parameters and stage II which shows a slow decrease, but with an enhanced fluctuation of the two parameters with increasing pulses of HIPIB generation. [ABSTRACT FROM AUTHOR]

A magnetically insulated ion diode (MID) with an improved external-magnetic field system has been developed and installed onto a TEMP-6-type high-intensity pulsed ion source in order to produce a high-intensity pulsed ion beam (HIPIB) for surface modification of materials. The external-magnetic field MID is operated in unipolar mode based on dielectric high-voltage flashover, and a double coaxial pulse-forming line (PFL) powered with a Marx generator is used to form the unipolar pulse of nanosecond width. A specially designed cathode has been constructed with a forked connection to two symmetrically installed transformers to improve the effect of the magnetic field and thus increase the stability of generation and propagation of the ion beam. It was found that the efficient generation of HIPIB mainly depended on the magnetic field strength, the gas pressures in reverse and output switches of PFL, and the anode-cathode (A - K) gap of the external-magnetic field MID. A proper magnetic field strength was found with magnetic field power system at dc charging voltage of 8 kV. The proper A - K gap distance is not uniform with the value varied from 6 to 8 mm. Suitable gas pressures for reverse and output switches were about 1.2 and 2.4 atm, respectively, at a charging voltage of 40 kV to the Marx generator. The most efficient plasma generation and ion extraction led to a maximum output of HIPIB with a peak ion current density of 300 A cm[SUP-2] and a beam pulse width of 80 ns (full width at half maximum), at an accelerating pulse of 300-350 kV with a pulse width of 70 ns. [ABSTRACT FROM AUTHOR]

A high-intensity pulsed ion source of TEMP-type series, operating in bipolar mode, has been developed as a unique pulsed energy source to produce a high-intensity pulsed ion beam (HIPIB) for surface modification of materials. To generate the ion beam, a specially shaped bipolar pulse, consisting of a first negative pulse and a second delayed positive pulse both of nanosecond width, is formed by a double coaxial pulse-forming line (PFL) powered with a Marx generator and supplied to a magnetically insulated ion diode (MID) by a self-magnetic field. It is found that the efficient generation of a HIPIB is mainly dependent on the delay time of the bipolar pulse, adjusted by pressure ratio in the two gas switches of a PFL, and the anode-cathode (A-K) gap distance in the self-magnetic field MID. The delay time determines the effective area on the anode surface for plasma generation and the A-K gap distance ensures the stability of the process. A proper delay time and a proper A-K gap distance are obtained by a series of experimental investigations. Under delay time from 30 to 280 ns and several different A-K gap distances, the typical wave forms of the bipolar pulses at a dc charging voltage of 45 kV to Marx generator are illustrated to clarify the effects of delay time and A-K gap distance on the ion beam generation. The proper A-K gap distance is not uniform, varied from 6 to 8 mm, and the corresponding proper delay time is 250 ns. The most efficient plasma generation leads to a maximum output of HIPIB with a peak ion current density of 350 A cm[sup -2] and a beam pulse width of 75 ns (full width at half maximum), at an accelerating pulse of 220 kV with a pulse width of 100 ns. [ABSTRACT FROM AUTHOR]

Lavender flower essential oil had been used for a variety of therapeutic and cosmetic purposes. Previous studies mainly focused on essential oil composition and extraction methods, ignoring the factors that affected the production of essential oils, such as the floret number. This study aims to get a deep insight into the mechanism of floret number differences. Hormone analysis showed that there was a positive correlation between abscisic acid (ABA) content and the number of florets, while indole-3-acetic acid (IAA) was negatively correlated with floret numbers. RNA-Seq results showed that 1 035 differentially expressed genes (DEG) can be identified, of which 19 genes were significantly enriched in the carotenoid biosynthesis pathway. Common network analysis showed that the expression of the key genes of ABA pathway metabolism was negatively related to the DEG of IAA, especial IAA18. Exogenous IAA significantly inhibited the number of lavender florets and affected the expression of ABA metabolism genes. The results might be useful for a better understanding of the molecular mechanism of floret number differences. [ABSTRACT FROM AUTHOR]

Both nitriding and smoothing of titanium have been achieved under irradiation of intense pulsed ion beam in a vacuum of 2×10-2 Pa. Applying a screening method, we find that medium ion-beam intensity and multi-shot irradiation are effective for the processing, where repetitive surface melting with limited ablation favored Ti nitride formation as well as surface smoothing. The present results demonstrate that ambient gas atoms/molecules can be efficiently incorporated in metal matrices to form compounds under the ion-beam irradiation. The finding is of great significance for extending application scope of the ion-beam technique in materials research and processing, combined with the recent success in introducing ambient gas into the processing chamber. [ABSTRACT FROM AUTHOR]

Abstrac: t—The results of studying the influence of radiation defects on the error of measuring the total energy of a high-intensity pulsed ion beam and its cross-sectional distribution using the thermal-imaging diagnostics (TID) are presented. The investigations were carried out at the TEMP-6 accelerator (200–250 kV, 120 ns) during operation of an ion diode in the mode of self-magnetic insulation of electrons. The ion beam consisted of С+ carbon ions (85%) and protons; the energy density at the focus was 1–5 J/cm2. It was found that when targets of different metals (titanium, stainless steel, and copper) are used, the readings of the TID differed by 40–60% for the energy-density instability in a pulse train (for a single target) of at most 10%. The causes of errors in the energy-density measurements were analyzed. It is shown that when a metal target is irradiated with a powerful ion beam, a significant number of radiation defects are formed in it. The ion-energy losses on their formation are proportional to the initial thermal energy in the target after its irradiation with the ion beam and have values of 22% in stainless steel, 30% in copper, and 70% in titanium targets. When the ion-energy loss on the formation of radiation defects is taken into account, the error of the TID technique does not exceed 15% when using targets of different metals. [ABSTRACT FROM AUTHOR]

Water drops impacting windshields of high-speed trains and aircraft as well as blades in steam turbine power generators obliquely and at high speeds are difficult to repel. Impacting drops penetrate the void regions of nanotextured and microtextured superhydrophobic coatings, with this pinning resulting in the loss of drop mobility. In order to repel high-speed water drops, we nanotextured polymer surfaces with nanowire bundles separated from their neighbors by microscale void regions, with the nanowires in a bundle separated from their neighbors by nanoscale void regions. Water drops with speeds below a critical speed rebound completely. Water drops with speeds exceeding a critical speed rebound partially, but residual droplets that begin to be pinned undergo a spontaneous dewetting process and slide off. The natural oscillations of residual droplets drive this dewetting process in the interbundle void regions, resulting in a transition from the sticky Wenzel state to the slippery Cassie state without external stimuli. [ABSTRACT FROM AUTHOR]

Summary Microsatellite DNAs were used to analyze the variations and structures of three geographic populations of Cirrhina molitorella in Xijinag (XJ), Beijiang (BJ), and Dongjiang (DJ) in the Pearl River Basin as well as one cultured population. The genetic diversity was calculated using microsatellites. This data revealed high genetic variations in both wild and cultured populations of C. molitorella, with average He ranging from 0.7081 to 0.7723. The analysis of molecular variance ( amova) showed that only 5.76% of the variance was among populations, whereas 94.24% of the variance was within populations. Exact testing for non-differentiation showed insignificant differentiation among populations (P > 0.05), but a phylogenetic tree calculated in Phylip produced evidence for some differentiation between wild and cultured populations. [ABSTRACT FROM AUTHOR]

RNA-mediated virus resistance is one kind of post-transcriptional gene silencing (PTGS). PTGS can be induced by transgenes or by viral infection that triggers the degradation of RNAs with homology or complementarity to the foreign genes’ transcript or viral RNA. In this study, tobacco plants transformed with untranslatable Potato virus YN (PVYN)-coated protein (CP) gene were used to examine the correlation between transgene integration patterns and RNA-mediated resistance more directly. HindIII and EcoRI were used to digest genomic DNAs from progeny T1 transgenic plants with a range of responses to PVYN infection. Southern blot analysis indicated that nearly all of the highly resistant plants contained repeat foreign sequences, including direct repeat (DR) and inverted repeat (IR). Specifically, the highly resistant plants always contained both or one of these constructs, with the majority containing both constructs. Conversely, almost all of the susceptible transgenic plants contained neither construct, though some contained multiply copies. Our results show that transgene integration rather than copy number is the key factor for RNA-mediated virus resistance. Many researchers identified double-stranded RNA (dsRNA) as the common link for PTGS triggered by various events. Therefore, we suggest that only transgenes can make dsRNA, by transcription or other pathways, and either repeated constructs (IR or DR) or single copy will induce RNA-mediated PVYN resistance. [ABSTRACT FROM AUTHOR]

American shad Alosa sapidissima, an anadromous clupeid, exhibits variation in reproductive strategies, including semelparity and iteroparity. It provides an excellent model for studying the behaviour of germ cells in anadromous fish during their migration from sea to river. The vasa gene was characterized in A. sapidissima as a germ‐cell marker to elaborate the process of germ‐cell development and differentiation in anadromous species. A complementary (c)DNA fragment of 819 bp, partial open reading frame (ORF), was cloned by degenerate PCR and named as ASvas. In adult A. sapidissima, vasa transcript was exclusively detected in gonads by reverse‐transcription (RT)‐PCR. Through chromogenic in situ hybridization, the vasa messenger (m)RNA was specifically detected in primordial germ cells (PGC) in embryos and germ cells at early stages in ovary and testis. Besides, the cellular distribution profile of Vasa protein also proved that vasa gene could be used as a germ‐line marker to trace the PGCs migration during embryogenesis and the germ‐cell differentiation during gametogenesis in A. sapidissima. During embryogenesis, the migrating PGCs were clearly detected at tail‐bud stage and the PGCs reached the genital ridge at the stage of pre‐hatching stage in A. sapidissima embryos. During gametogenesis, the Vasa protein was dynamically expressed in differentiating germ cells at different stages in adult gonads. As far as we know, this is the first report to demonstrate the PGCs migration and germ‐cell differentiation through vasa gene expression in the anadromous species. The findings will pave a way for investigating germ‐cell development and maturation in the A. sapidissima and other anadromous fish. [ABSTRACT FROM AUTHOR]

Recently, samples of the Chinese tallow tree (Sapium sebiferum) displaying yellowing symptoms were collected from a grove in Tai'an, Shandong Province, China. The association of phytoplasma with yellowing disease was ascertained using nested polymerase chain reaction (PCR) of the 16S rRNA gene by using the phytoplasma-specific universal primer pair P1/P7, followed by R16F2n/R16R2 as nested primers, and rp genes primed using rpL2F3/rp(I)R1A followed by rp(III)-FN/rp(I)R1A. The sequence and phylogenetic analyses of the 16S rRNA gene and rp genes revealed that the phytoplasma associated with the Chinese tallow tree belonged to the 16SrIII group (the X-disease group). Computer-simulated and gel-based restriction fragment length polymorphism (RFLP) analyses revealed that the RFLP patterns were different from the reference patterns of all previously established 16SrIII subgroups, with the maximum similarity coefficient exceeding the threshold for delineation of a new subgroup RFLP pattern type within the 16SrIII group. Thus, the phytoplasma associated with the Chinese tallow tree yellowing disease, designated as 'CTTY', represents a new subgroup (16SrIII-Y). This study shows the Chinese tallow tree as a new host of phytoplasma belonging to the 16SrIII group in China and worldwide. [ABSTRACT FROM AUTHOR]

A phytoplasma infecting Sophora Root ( Sophora alopecuroides) was detected and identified in Alar, Xinjiang Uygur Autonomous Region of China. Typical phytoplasma bodies were observed in sieve tubes of the diseased plants by transmission electron microscopy. A partial 16S rRNA gene and ribosomal protein (rp) genes containing rpl22 ( rplV) and rps3 ( rpsC) were amplified by direct and nested PCR. Based on the sequence similarity of the 16S rRNA and rp genes with accompanying phylogenetic analyses, the phytoplasma associated with Sophora Root yellows belongs to the 16SrI group (aster yellows group). Virtual RFLP analysis of these 16S rRNA and rp gene sequences showed distinct differences from those of reference phytoplasma strains representing previously described subgroups of the 16SrI group. Moreover, the similarity coefficient (0.92) of the RFLP profile of this phytoplasma was less than the threshold similarity coefficient (0.97) required for subgroup classification. Thus, the phytoplasma isolate of Sophora Root plants, designated as 'SoRY', represents a new subgroup. Furthermore, this is the first report of phytoplasma disease associated with Sophora Root plants. [ABSTRACT FROM AUTHOR]

Polarization splitting wavelength-selective characteristics of Au-filled high-birefringence photonic crystal fiber (HB-PCF) based on the finite element method is investigated. Numerical results show that the polarization splitting effect can be observed in metal-filled HB-PCF. The resonances points and strength in two polarizations can be adjusted by changing the fiber birefringence, the pitch between the adjacent air holes and the size of the metal wires. Finally, two kinds of Au-filled HB-PCFs with completely polarization splitting and filtering characteristics in communication wavelength are designed. Results show that this polarization splitting effect in metal-filled HB-PCF is very useful for further studies in polarization-dependent wavelength-selective applications and other fiber-based plasmonic devices. [ABSTRACT FROM AUTHOR]

The complete genomic sequence of a Chinese Potato virus X isolate FX21 (PVX-FX21) was determined from three overlapping cDNA clones. The genome of PVX-FX21 is 6435 nucleotides in length excluding the poly(A) tail and contains five open reading frames (ORFs). Its entire genomic sequence shares 95.2–96.3% identities with Asian and European isolates, and 77.3–77.8% with American isolates. Phylogenetic analysis of the complete genomic sequence reveals two groups: the Eurasian group and the American group. PVX-FX21 belongs to the Eurasian group and forms a separate sub-branch with three Asian isolates. Similar analyses of the coat protein genes of 37 PVX isolates also reveal two major groups. All PVX isolates from Asia are clustered to group I, whereas isolates from Europe and America are clustered to both groups. Nucleotide sequence diversity analyses show that there is no geographical differentiation between PVX isolates and that constraint on the ORF encoding RNA-dependent RNA polymerase is much higher than those on the other four ORFs. [ABSTRACT FROM AUTHOR]

In 2005, rose plants ( Rosa rugosa cv. ‘Plena’) exhibiting typical phytoplasma disease symptoms of stunting, yellowing, witches’-broom and dieback were observed in Pingyin, Shandong Province, China. The disease, rose witches’-broom (RoWB), is progressively destructive and can be graft-transmitted. Polymerase chain reaction (PCR), sequencing of PCR products and electron microscopy were used to investigate the possible association of phytoplasma with RoWB. All results indicated that presence of phytoplasma in the symptomatic rose plants. Sequence alignment of 16S rRNA gene, tuf gene and rp gene confirmed that the phytoplasma associated with RoWB is the causal agent of Paulownia witches’-broom disease, which might be transmitted from the paulownia tree that is several meters away. To our knowledge, this is the first report of the molecular characterization of phytoplasma infecting rose in China. [ABSTRACT FROM AUTHOR]

Tobacco vein banding mosaic virus (TVBMV) is of increasing importance in tobacco production on the Chinese mainland. The 3′-terminal genomic sequences (1624 nucleotides) of 12 TVBMV isolates from China were determined and compared to the sequences of only four TVBMV isolates available in databanks. The results revealed that TVBMV consists of several phylogenetically distinguishable strains that show a degree of correlation with the geographical origin. Two isolates from Yunnan had a unique putative NIb/CP proteolytic cleavage site of Q/N that is uncommon for potyviruses, whereas other TVBMV isolates had the more typical Q/G amino acids at that site. One isolate (ZB6) from Zibo, Shandong Province, was predicted to have experienced recombination within the characterized genomic region. [ABSTRACT FROM AUTHOR]

An abstract of the article on stem scab symptoms in pomegranate trees in China is presented

We have recently reported that systemic and chronic administration of recombinant tumour necrosis factor alpha (TNF-α), as well as streptococcal preparation (OK-432), inhibits development of insulin-dependent diabetes mellitus (IDDM) in NOD mice and BB rats, models of IDDM. In this study we examined whether serum containing endogenous TNF induced by OK-432 injection could inhibit IDDM in NOD mice. Treatment twice a week from 4 weeks of age with OK-432-injected mouse serum, which contained endogenous TNF (75U), but not IL-1, IL-2 and interferon-gamma (IFN-γ small gamma) activity, reduced the intensity of insulitis and significantly inhibited the cumulative incidence of diabetes by 28 weeks of age in NOD mice, as compared with the incidence in non-treated mice (P<0.01) and in mice treated with control serum (P<0.02), This inhibitory effect of the serum was diminished, although not significantly, by neutralization of serum TNF activity with anti-mouse TNF antibody. In the mice treated with the serum from OK-432-injected mice, Thy-1.2+ or CD8+ spleen cells decreased (P<0.01) and surface-Ig+ (S-Ig+) cells increased (P<0.05), whereas the proliferative response of spleen cells to concanavalin A (P<0.01) and lipopolysaccharide (P<0 05) increased. The results indicate that the inhibition by OK-432 treatment of IDDM in NOD mice was partially mediated by serum factors including endogenous TNF. [ABSTRACT FROM AUTHOR]

Tobacco vein banding mosaic virus (TVBMV) is a species of the largest plant virus genus Potyvirus. Its incidence has been increasing in Chinese tobacco-growing area. TVBMV isolates can be clustered into three genetic groups that are corresponding with their geographical origin. We have reported the complete genomic sequence of TVBMV isolate YND with unique NIb/CP cleavage site. Here, we determined and analyzed the complete genomic sequence of isolate HN39, which was collected from tobacco in Henan Province and represented Chinese prevalent strain of TVBMV. HN39 has similar host range with YND, but induce mild vein banding symptom in Nicotiana tabacum cv. Samsun. The genome of TVBMV-HN39 is composed of 9,570 nucleotides, excluding the poly(A) tail. It contains a large ORF of 9,240 nucleotides and encode a polyprotein of 3,079 amino acids. The putative NIa-Pro cleavage site for NIb/CP is Q/G. The identities between the complete genomes of isolates HN39 and YND were 90.0% at nucleotide level and 95.4% at amino acid level. As for other potyviruses, HN39 shared the highest identity with wild tomato mosaic virus (WTMV) at complete genomic level, while different genes shared the highest identities with different potyviruses. This is the second complete genomic sequence of TVBMV reported. [ABSTRACT FROM AUTHOR]

The article discusses the Beet mosaic virus (BtMV) which infects vegetables, particularly lettuce (Lactuca sativa) in China. Accordingly, BtMV is widespread and mainly infects the plants belonging to the Chenopodiaceae, Solanaceae and Fabaceae. In 2004 and 2006, a series of field surveys were conducted to investigate such virus in Shandong Province, China. It mentions that lactuca sativa has shown symptoms of mosaic, puckering and severe stunting with an incidence of 30-40 %. Several tests were conducted and results indicate that the virus is BtMV.