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Xylella fastidiosa is a xylem-limited bacterium in plant hosts and causes Pierces disease (PD) of grapevines, which differ in susceptibility according to the Vitis species (spp.). In this work we compared X. fastidiosa biofilm formation and population dynamics when cultured in xylem saps from PD-susceptible and -resistant Vitis spp. under different conditions. Behaviors in a closed-culture system were compared to those in different sap-renewal cultures that would more closely mimic the physicochemical environment encountered in planta. Significant differences in biofilm formation and growth in saps from PD-susceptible and -resistant spp. were only observed using sap renewal culture. Compared to saps from susceptible V. vinifera, those from PD-resistant V. aestivalis supported lower titers of X. fastidiosa and less biofilm and V. champinii suppressed both growth and biofilm formation, behaviors which are correlated with disease susceptibility. Furthermore, in microfluidic chambers X. fastidiosa formed thick mature biofilm with three-dimensional (3-D) structures, such as pillars and mounds, in saps from all susceptible spp. In contrast, only small aggregates of various shapes were formed in saps from four out of five of the resistant spp.; sap from the resistant spp. V. mustangensis was an exception in that it also supported thick lawns of biofilm but not the above described 3-D structures typically seen in a mature biofilm from the susceptible saps. Our findings provide not only critical technical information for future bioassays, but also suggest further understanding of PD susceptibility.

Photocatalytic removal of hexavalent chromium (Cr(VI)) based on semiconductor is important under visible light for environment and energy. Herein, a visible light-responsive heterojunction composed of molybdenum disulfide and zinc indium sulfide was synthesized through a simple one-pot hydrothermal method to ensure full contact between the two components to efficiently improve the Cr(VI) reduction. The MoS2/ZnIn2S4 composites build heterojunctions between MoS2 and ZnIn2S4 to inhibit recombination of photogenerated holes and electrons and provide the reaction sites to trap photogenerated electrons to participate in the reduction of Cr(VI). The highly efficient reduction of Cr(VI) was obtained by adjusting the proportion of molybdenum disulfide. It demonstrates that the 0.5 wt% MoS2/ZnIn2S4 composite microstructures show the highest degradation rate of 0.1989 s−1 under visible light irradiation, 1.7 times of bare ZnIn2S4. Moreover, the MoS2/ZnIn2S4 showed excellent stability during photocatalytic recyclable processes. This work encourages researchers to remove Cr(VI) by constructing effective heterojunction structures. [ABSTRACT FROM AUTHOR]

Due to high theoretical capacity and low cost of CuSbS2, it is deemed to be one of the most promising anode materials for lithium-ion batteries (LIBs). In this paper, the effects of different Cu/Sb ratios on the properties of composites prepared by one-step microwave irradiation method were studied. The results showed the increasement of Cu element could improve conductivity of anode material and the structure stability to reduce the capacity loss. And increasing composition of Cu element also could improve the initial columbic efficiency. The best initial discharge capacity was as high as 3001.9 mA hg−1, and even the specific capacity still kept 215.8 mA hg−1 after 120 cycles, which was got at 1:3 of Cu/Sb ratio. This work provides a method for the Cu/Sb ratio effect of the performance for the LIBs. [ABSTRACT FROM AUTHOR]

In this work, a synergy structure to improve the photocatalytic properties of materials was proposed. CuSbS2 nanoparticles synthesized by microwave irradiation method were dispersed in TiO2 sol to form CuSbS2–TiO2 nanoparticles. The properties of composite materials with different TiO2 sol concentration were investigated by XRD, XPS, etc. The results indicated the as-synthesized CuSbS2 nanoparticles exhibited chalcostibite structure and the TiO2 showed anatase phase. The CuSbS2–TiO2 nanoparticles had high absorbance in the visible light and good photocatalysts for the photodegradation reaction of Rhodamine B (RhB). When TiO2 sol concentration was 0.23 mol/L, the sample possessed a photocatalytic degradation rate of 0.002 min−1 for the degradation of RhB, which was 3 times higher than that by the bare amorphous TiO2 (0.0007 min−1). [ABSTRACT FROM AUTHOR]

The rare-earth oxide nanoparticles along carbon nanotubes (CNTs) (M2O3/CNTs, M = Y, Nd, Sm) were prepared by in situ solvothermal method. Products were characterized by infrared spectroscopy, X-ray diffraction, transmission electron microscopy, energy-dispersive X-ray spectrometry, scanning electron microscopy, and Brunauer-Emmett-Teller method. M2O3/CNTs presented good morphology and large surface area. Furthermore, catalysis of M2O3/CNTs during the thermal decomposition of ammonium perchlorate (AP) was evaluated by differential thermal analysis (DTA). Compared with Nd2O3/CNTs and Sm2O3/CNTs, Y2O3/CNTs nanocomposites showed the best catalytic effect on the thermal decomposition of AP. With the addition of 2 wt.% Y2O3/CNTs nanocomposite, high decomposition temperature of AP decreased by 125.5°C, and the total DTA heat release increased by 2.027 kJ·g−1. [ABSTRACT FROM AUTHOR]

In this paper, CuSbS2 thin films were prepared by a facile and environmental-friendly chemical solution method at low temperature. The effect of sulfurization temperature was studied. The properties of CuSbS2 thin films were investigated by X-ray diffraction, scanning electron microscopy, UV–Vis and photocurrent response measurement. The results indicated CuSbS2 thin films sulfurized at 350 °C showed better crystallinity and no impurity phase. The as-prepared CuSbS2 film had a band gap of 1.5 eV and an obvious photoconductivity. [ABSTRACT FROM AUTHOR]

The Fe3O4/reduced graphene oxide (Fe3O4/RGO) nanocomposites with good dispersibility were synthesized for targeted delivery of paclitaxel (PTX). Firstly, the superparamagnetic Fe3O4/functional GO nanocomposites were prepared via hydrothermal method in which GO sheets were modified by surfactant wrapping. The Fe3O4/RGO nanocomposites were successively prepared through the reduction of graphene oxide. The products were investigated by Fourier-transform infrared spectrum, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, and vibration sample magnetometry. It was found that spherical Fe3O4 nanoparticles were uniformly anchored over the RGO matrix and the nanocomposites were superparamagnetic with saturation magnetization (Ms) of 9.39 emu/g. Then PTX was loaded onto Fe3O4/RGO nanocomposites, and the drug loading capacity was 67.9%. Cell viability experiments performed on MCF-7 demonstrated that the Fe3O4/RGO-loaded PTX (Fe3O4/RGO/PTX) showed cytotoxicity to MCF-7, whereas the Fe3O4/RGO displayed no obvious cytotoxicity. The above results indicated that Fe3O4/RGO/PTX nanocomposites had potential application in tumor-targeted chemotherapy. [ABSTRACT FROM AUTHOR]

Xylella fastidiosa causes Pierce's disease (PD) on grapevines, leading to significant economic losses in grape and wine production. To further our understanding of X. fastidiosa virulence on grapevines, we examined the PD1311 gene, which encodes a putative acyl-coenzyme A (acyl-CoA) synthetase, and is highly conserved across Xylella species. It was determined that PD1311 is required for virulence, as the deletion mutant, ΔPD1311, was unable to cause disease on grapevines. The ΔPD1311 strain was impaired in behaviours known to be associated with PD development, including motility, aggregation and biofilm formation. ΔPD1311 also expressed enhanced sensitivity to H2O2 and polymyxin B, and showed reduced survival in grapevine sap, when compared with wild-type X. fastidiosa Temecula 1 (TM1). Following inoculation, ΔPD1311 could not be detected in grape shoots, which may be related to its altered growth and sensitivity phenotypes. Inoculation with ΔPD1311 2 weeks prior to TM1 prevented the development of PD in a significant fraction of vines and eliminated detectable levels of TM1. In contrast, vines inoculated simultaneously with TM1 and ΔPD1311 developed disease at the same level as TM1 alone. In these vines, TM1 populations were distributed similarly to populations in TM1-only inoculated plants. These findings suggest that, through an indirect mechanism, pretreatment of vines with ΔPD1311 suppresses pathogen population and disease. [ABSTRACT FROM AUTHOR]

The thermal process of a (001) silicon wafer subjected to a continuous-wave (CW) laser and 100-10000 Hz pulsed laser irradiation is investigated experimentally and numerically. The temperature evolution of the spot center is measured using an infrared radiation pyrometer. The waveforms of the temperature evolution curves provide valuable information about melting, solidification, vaporization, and fracture. To gain a better understanding of the thermal process, a three-dimensional finite element model is established, and numerical simulations are conducted to analyze the temperature, stress, and dislocation field. The results show that the 10 kHz laser exhibits the highest heating efficiency before vaporization, but the lowest ablation efficiency after vaporization due to the shielding effect of vapor. The diffusion time of vapor is found to be more than 50 µs. Fracture occurs during 1 kHz laser irradiation. The motion of liquid may play a significant role, but it cannot be evidenced by a simulation due to complex dependence of material parameters on dislocation. This issue should be addressed as a priority in future studies.

In this study, a Cu 2 O-Au nanoparticles (NPs) heterojunction catalyst anchored on wood was developed by in situ reduction and hydrothermal treatment, and the properties of the catalyst were systematically characterized. The catalyst exhibited prominent photocatalysis of methyl orange (MO, 0.169 min - 1 ), and tetracycline (TC, 0.122 min -1 ) which were degraded completely within 20 min. Even after four recyclings, the efficiency of MO degradation by the catalyst remained at 80%. The natural wood with three-dimensional porous structures acted as a reducing agent and a stabilizer for Au NPs and Cu 2 O, which helped to maintain high performance and reusability. The presence of Au NPs mediated the light-induced electron transfer and enhanced the absorption of visible light for promoting photocatalytic activity. The intermediates of contaminants within the degradation process were characterized by liquid chromatography-mass spectrometry. Additionally, the photogenerated superoxide radicals and holes were identified by electron spin resonance. Thus, the potential degradation mechanism catalyzed by the Cu 2 O-Au NPs-wood was proposed. This findings of this study valorizes biomass as a photocatalyst for wastewater remediation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Insufficient oxygen supply at the tumor site and hypoxia caused during tumor treatment lead to a poor therapeutic effect and poor prognosis. Therefore, effectively overcoming the problem of hypoxia in tumors and avoiding hypoxia that compromises the efficacy of the treatment could improve the anti-tumor therapeutic effect. Thus, this study reports the ability of W 18 O 49 @EP nanoparticles to release reactive oxygen species (ROS) during the combined tumor radiotherapy (RT) and photodynamic therapy (PDT). The release of ROS by the nanoparticles during near infrared light (NIR) irradiation was demonstrated by in vitro and in vivo experiments, realizing an effective PDT without inducing hypoxia. Indeed, the ROS did not derive from the oxygen in the tumor microenvironment but they were released by the nanoparticles. Thus, ROS could improve the therapeutic effect of RT avoiding the problem of hypoxia after RT. Hence, W 18 O 49 @EP nanoparticles greatly improved the anti-tumor effect due to their effectiveness despite the insufficient oxygen supply and hypoxia caused by traditional RT and PDT., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Wang, Hao, Li and Liu.)

The effects of tumorigenic and nontumorigenic strains of Agrobacterium vitis on graft strength and growth of grapevines was studied. A procedure was developed for inoculating graft interface surfaces with A. vitis and for measuring the force required to break grafts at different time points. Cuttings were soaked in an aqueous suspension of bacteria, about 10 6 CFU/ml, and bacteria were spread onto the graft interface during the grafting procedure. Tumorigenic strain CG49 caused reduced bud germination and increased callus (crown gall) at the graft union and at the base of cuttings at 30 days postinoculation (dpi) and significantly reduced shoot growth by 60 dpi whereas, at the same time points, nontumorigenic strain F2/5 inhibited callus formation but did not affect bud germination or shoot growth. Graft strength was enhanced at 30 dpi with CG49, presumably because the crown gall callus served to secure the union; graft strength was weakened by F2/5 over the same period. Between 30 and 60 dpi, the greatest increase in graft strength was observed in the water control. Following graft union inoculations, the A. vitis population increased more than 1,000-fold within 5 days.