22 research outputs found

    Isolation, characterization, and genomic analysis of a novel bacteriophage MA9V-1 infecting Chryseobacterium indologenes: a pathogen of Panax notoginseng root rot

    Get PDF
    Chryseobacterium indologenes is one of the primary causative agents of root rot of Panax notoginseng, which significantly affected plant growth and caused economic losses. With the increasing incidence of antibiotic-resistant bacterial phytopathogens, phage therapy has been garnered renewed attention in treating pathogenic bacteria. However, the therapeutic potential of phage therapy on root rot of P. notoginseng has not been evaluated. In this study, we isolated a novel lytic phage MA9V-1 infecting C. indologenes MA9 from sewage and monitored the formation of clear and round plaques with a diameter of approximately 0.5–1.5 mm. Phage MA9V-1 exhibited rapid absorption (>75% in 8 min), a latency period of 20 min, and a burst size of 10 particles per cell. Transmission electron microscopy indicated that the phage MA9V-1 is a new myovirus hosting C. indologenes MA9. Sequencing of phage genomes revealed that phage MA9V-1 contained a linear double-stranded DNA genome of 213,507 bp with 263 predicted open reading frames, including phage structure, host lysing, and DNA polymerase/helicase but no genes of tRNA, virulence, and antibiotic resistance. Our proteomic tree and genomic analysis revealed that phage MA9V-1 shares identity with Sphingomonas phage PAU and Tenacibaculum phage PTm1; however, they also showed apparent differences. Further systemic evaluation using phage therapy experiments on P. notoginseng suggested that phage MA9V-1 can be a potential candidate for effectively controlling C. indologenes MA9 infection. Thus, we have presented a novel approach to solving root rot in P. notoginseng

    Increased Expression of Foxj1 after Traumatic Brain Injury

    Get PDF
    Foxj1 is a member of the Forkhead/winged-helix (Fox) family of transcription factors, which is required for postnatal differentiation of ependymal cells and a subset of astrocytes in the subventricular zone. The subpopulation of astrocytes has the ability of self-renew and neurogenic potential differentiated into astrocytes, oligodendrocytes, and neurons. However, its expression and function in the central nervous system lesion are not well understood. In this study, we performed a traumatic brain injury (TBI) model in adult rats and investigated the changed expression of Foxj1 in the brain cortex. Western blot and immunohistochemistry analysis showed that the expression of Foxj1 gradually increased, reached a peak at day 3 after TBI, and declined during the following days. Double immunofluorescence staining revealed that Foxj1 was co-expressed with MAP-2 and GFAP. In addition, we detected that Ki67 had the co-localization with NeuN, GFAP, and Foxj1. All our findings suggested that Foxj1 may be involved in the pathophysiology of brain after TBI

    Seismic Performance of a New Assembled Bolt-Connected Concrete Beam–Column Joint: Experimental Test and Finite Element Modeling

    No full text
    A new assembled bolt-connected concrete beam–column joint is proposed, aimed at completing the repair of a post-earthquake node by replacing the bolts and precast beams. Low-cycle loading tests were performed on two new full-scale connections to investigate the effect of bolt strength on the seismic performance of the new connections. A finite element model was established based on the experimental node specimens and compared with the experimental results to verify the accuracy of the finite element simulation results. The seismic performance of the new joints under different axial ratios was studied using finite element software to determine the effect of the axial pressure ratio on the seismic performance of the new joints. Based on the research carried out, a new improved joint was designed, numerical models of the improved joint were established using finite element software, and the seismic performance of the improved joint was compared with the results of the experimental simulation to analyze the seismic performance of the improved joints. The results of the study showed that the bolts and precast concrete beams are the main load-bearing members in the period of service. The joint can be repaired by replacing the bolts and precast concrete beams under seismic action, which meets the new joint design concepts. The finite element simulation results are in good agreement with the experimental results. The larger the axial compression ratio, the earlier the failure stage of the concrete, and the faster the bearing capacity and ductility decrease. The larger the axial compression ratio, the higher the initial stiffness of the joints and the greater the rate of stiffness reduction. The bolt stress distribution of the modified and optimized joints is more satisfactory. This change in node form can improve the recovery efficiency of the joint to a certain extent

    EFFECT OF CALCINATION TEMPERATURE ON THE STRUCTURE AND CATALYTIC PERFORMANCE OF THE CU-MCM-41 CATALYSTS FOR THE SYNTHESIS OF DIMETHYL CARBONATE

    No full text
    A series of Cu-MCM-41 catalysts were synthesized through in-situ hydrothermal preparation method, calcinated at different temperatures and characterized by thermogravimetric and differential scanning calorimetry (TG-DSC), N2 adsorption-desorption, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FI-IR), transmission electron microscopy (TEM) and hydrogen temperature-programmed (H2-TPR). The effect of calcination temperature on the structural properties and selective oxidation of dimethoxymethane (DMM) to dimethyl carbonate (DMC) were discussed in detail. The results showed that the calcination temperature played important role on the microstructure and catalytic activity of the Cu-MCM-41 catalysts. At the calcination temperature 550 °C, the Cu-MCM-41 catalyst possessed higher surface area, smaller pore diameter, stronger metal-support interaction, and better CuO dispersion compared the other catalysts, and the corresponding catalyst exhibited excellent activity and stability for the DMC synthesis. Under the reaction conditions at 2.0 MPa and 130 °C, the highest DMM conversion was 99.47% with the best DMC selectivity of 85.01%. In addition, the catalyst was reused four times without significant loss of performance

    Biosorption characteristics of a highly Mn(II)-resistant Ralstonia pickettii strain isolated from Mn ore.

    No full text
    Microorganisms play an important role in immobilizing and detoxifying excessive Mn; however, there is so far a lack of sufficient information concerning highly Mn(II)-tolerant bacteria. The present study was conducted to analyze the bio-sorption characteristics of a strain (HM8) isolated from manganese ore wastes. Analytical data from the 16S rDNA sequence determination showed that the species, HM8, had a 99% similarity to Ralstonia pickettii. Results from the designed physiological, biochemical and isothermal adsorption tests indicated that HM8 did not only grow well at a Mn(II) concentration level of 10,000 mg/L but also removed 1,002.83 mg/L of Mn(II) from the bulk solution of the culture, showing that the isolated strain possessed strong capabilities to tolerate and remove Mn(II). In the isothermal bio-sorption experiments performed to investigate the effects of relevant factors on Mn(II) sorption, the highest Mn(II) removal rate was obtained at the contact time 72 h, temperature 40°C, and pH 6.0, while the differences in both strain growth and Mn(II) removal rate between different inoculated HM8 doses were found to be insignificant within the tested range. Scanning electron microscopy showed that, under Mn(II) stress, HM8 cells appeared irregular and cracked, with apparent wrinkles on the surface. The peaks in the Fourier transform infrared spectra showed that hydroxyl and carboxyl groups were the main functional groups for Mn(II) adsorption. The experimental data supported the practical application of HM8 as a biological adsorbent for remediation of heavily Mn contaminated sites

    α-Lipoic Acid Prevents Bupivacaine-Induced Neuron Injury in Vitro Through a PI3K/Akt-Dependent Mechanism

    No full text
    Background: Bupivacaine is an amide type local anesthetic which is widely used for epidural anesthesia and nerve blockade in patients. However, local administration of bupivacaine could cause neuron injury showing transient neurologic symptoms. α-Lipoic acid (LA) was shown to protect nerve cells from substance-induced injury. We hypothesized that LA administration could attenuate bupivacaine-induced neurotoxicity. Methods: To evaluate our hypothesis, we treated mouse neuroblastoma N2a cells with LA 30 min before the cells were exposed to bupivacaine. We evaluated cellular injury by examination of cell viability, morphology changes, nuclear condensation, and Annexin V staining. We also examined the levels of intracellular reactive oxygen species (ROS) and activation of PI3K/Akt signaling pathway. In a separate experiment, we determined the effect of Akt inhibition on cell viability in the presence of LA and bupivacaine. Results: Bupivacaine treatment significantly induced cell injury as evidenced by decreased cell viability, increased nuclear condensation and Annexin V staining. Administration of LA significantly attenuated bupivacaine-induced cell injury. In addition, LA treatment increased the levels of phospho-Akt and phospho-GSK3β and attenuated bupivacaine decreased the levels of ROS. More significantly, pharmacological inhibition of Akt abolished the LA-induced protection from bupivacaine-caused cell injury. Conclusions: Our findings suggest that pretreatment of neuroblastoma cells with LA protected neural cells from bupivacaine-induced injury. The mechanisms involve activation of the PI3K/Akt signaling pathway

    Analysis of risk factors for delayed healing of peptic ulcer in patients with upper gastrointestinal bleeding

    No full text
    Objective: To investigate the risk factors for delayed healing of peptic ulcer in patients with upper gastrointestinal bleeding (UGIB), so as to provide evidences for clinical treatment. Methods: A total of consecutive 138 hospitalized patients with UGIB due to peptic ulcer from January 2012 to December 2021 were enrolled. The healing rate of peptic ulcer was determined under reexamination of gastroscopy after 1 week of treatment. The related indice were analyze with univariate analysis to determine possible influencing factors for peptic ulcer, including gender, age, body mass index (BMI), diabetes, history of taking steroid anti-inflammatory drugs (NSAIDS), smoking, drinking, Helicobacter pylori (Hp) infection, hemoglobin, serum albumin, ulcer location or Logistic regression analysis was performed to determine the independent risk factors. Results: Univariate analysis showed that age, levels of serum albumin, Forrest classification, the location and size of ulcers were associated with delayed healing of ulcers in patients with upper gastrointestinal bleeding (P<0.05). Multivariate Logistic regression analysis showed that Forrest classification, location and size of ulcers were independent risk factors for delayed healing of ulcers in patients with upper gastrointestinal bleeding(P<0.05). Conclusions: Forrest classification, location and size of ulcers in patients with upper gastrointestinal bleeding may delay the healing of peptic ulcer in patients with upper gastrointestinal bleeding and countermeasures should be taken to deal with the above risk factors

    The Enhanced Catalytic Performance and Stability of Rh/γ-Al2O3 Catalyst Synthesized by Atomic Layer Deposition (ALD) for Methane Dry Reforming

    No full text
    Rh/γ-Al2O3 catalysts were synthesized by both incipient wetness impregnation (IWI) and atomic layer deposition (ALD). The TEM images of the two catalysts showed that the catalyst from ALD had smaller particle size, and narrower size distribution. The surface chemical states of both catalysts were investigated by both XPS and X-ray Absorption Near Edge Structure (XANES), and the catalyst from IWI had higher concentration of Rh3+ than that from ALD. The catalytic performance of both catalysts was tested in the dry reforming of methane reaction. The catalyst from ALD showed a higher conversion and selectivity than that from IWI. The stability testing results indicated that the catalyst from ALD showed similar stability to that from IWI at 500 °C, but higher stability at 800 °C

    Essential Role of ERK Activation in Neurite Outgrowth Induced by α-Lipoic Acid

    Get PDF
    Background: Neurite outgrowth is an important aspect of neuronal plasticity and regeneration after neuronal injury. Alpha-lipoic acid (LA) has been used as a therapeutic approach for a variety of neural disorders. We recently reported that LA prevents local anesthetics-induced neurite loss. In this study, we hypothesized that LA administration promotes neurite outgrowth. Methods: To test our hypothesis, we treated mouse neuroblastoma N2a cells and primary neurons with LA. Neurite outgrowth was evaluated by examination of morphological changes and by immunocytochemistry for α-tubulin-3. ROS production was examined, as were the phosphorylation levels of ERK and Akt. In separate experiments, we determined the effects of the inhibition of ERK or PI3K/Akt as well as ROS production on LA-induced neurite outgrowth. Results: LA promoted significantly neurite outgrowth in a time- and concentration-dependent manner. LA stimulation significantly increased the phosphorylation levels of both Akt and ERK and transiently induced ROS production. PI3K/Akt inhibition did not affect LA-induced neurite outgrowth. However, the inhibition of ERK activation completely abolished LA-induced neurite outgrowth. Importantly, the prevention of ROS production by antioxidants attenuated LA-stimulated ERK activation and completely abolished LA-promoted neurite outgrowth. Conclusion: Our data suggest that LA stimulates neurite outgrowth through the activation of ERK signaling, an effect mediated through a ROS-dependent mechanism. This article is part of a Special Issue entitled: 11th European Symposium on Calcium

    MEK/ERKs Signaling Is Essential for Lithium-Induced Neurite Outgrowth in N2a Cells

    No full text
    Lithium, a drug used for the treatment of bipolar disorder, has been shown to affect different aspects of neuronal development such as neuritogenesis, neurogenesis and survival. The underlying mechanism responsible for lithium\u27s influence on neuronal development, however, still remains to be elucidated. In the present study, we demonstrate that lithium increases the phosphorylation of extracellular-signal regulated kinases (ERKs) and protein kinase B (Akt) and promotes neurite outgrowth in mouse N2a neuroblastoma cells (N2a). The inactivation of mitogen-activated protein kinase kinase (MEK)/ERKs signaling with a MEK inhibitor inhibits neurite outgrowth, but it enhances Akt activation in lithium-treated N2a cells. Furthermore, the inactivation of phosphoinositide-3-kinase (PI3K)/Akt signaling with a PI3K inhibitor increases both lithium-induced ERKs activation and lithium-induced neurite outgrowth. Taken together, our study suggests that lithium-induced neurite outgrowth in N2a cells is regulated by cross-talk between the MEK/ERKs and PI3K/Akt pathways and requires the activation of the MEK/ERKs signaling
    corecore