22 research outputs found

    Two jasmonic acid carboxyl methyltransferases in Gossypium hirsutum involved in MeJA biosynthesis may contribute to plant defense

    Get PDF
    Jasmonic acid (JA) and methyl jasmonate (MeJA), the crucial plant hormones, can induce the emission of plant volatiles and regulate the behavioral responses of insect pests or their natural enemies. In this study, two jasmonic acid carboxyl methyltransferases (JMTs), GhJMT1 and GhJMT2, involved in MeJA biosynthesis in Gossypium. hirsutum were identified and further functionally confirmed. In vitro, recombinant GhJMT1 and GhJMT2 were both responsible for the conversion of JA to MeJA. Quantitative real-time PCR (qPCR) measurement indicated that GhJMT1 and GhJMT2 were obviously up-regulated in leaves and stems of G. hirsutum after being treated with MeJA. In gas chromatography-mass spectrometry (GC-MS) analysis, MeJA treatment significantly induced plant volatiles emission such as (E)-β-ocimene, (Z)-3-hexenyl acetate, linalool and (3E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), which play vital roles in direct and indirect plant defenses. Moreover, antennae of parasitoid wasps Microplitis mediator showed electrophysiological responses to MeJA, β-ocimene, (Z)-3-hexenyl acetate and linalool at a dose dependent manner, while our previous research revealed that DMNT excites electrophysiological responses and behavioral tendencies. These findings provide a better understanding of MeJA biosynthesis and defense regulation in upland cotton, which lay a foundation to JA and MeJA employment in agricultural pest control

    Lipid Metabolism in Glioblastoma: From De Novo Synthesis to Storage

    No full text
    Glioblastoma (GBM) is the most lethal primary brain tumor. With limited therapeutic options, novel therapies are desperately needed. Recent studies have shown that GBM acquires large amounts of lipids for rapid growth through activation of sterol regulatory element-binding protein 1 (SREBP-1), a master transcription factor that regulates fatty acid and cholesterol synthesis, and cholesterol uptake. Interestingly, GBM cells divert substantial quantities of lipids into lipid droplets (LDs), a specific storage organelle for neutral lipids, to prevent lipotoxicity by increasing the expression of diacylglycerol acyltransferase 1 (DGAT1) and sterol-O-acyltransferase 1 (SOAT1), which convert excess fatty acids and cholesterol to triacylglycerol and cholesteryl esters, respectively. In this review, we will summarize recent progress on our understanding of lipid metabolism regulation in GBM to promote tumor growth and discuss novel strategies to specifically induce lipotoxicity to tumor cells through disrupting lipid storage, a promising new avenue for treating GBM

    3-D Numerical Study on Progressive Failure Characteristics of Marbles under Unloading Conditions

    No full text
    3-D particle-based discrete element method (PB-DEM) was employed to numerically study the mechanical and progressive failure characteristics of pre-fissured marble specimens under conventional triaxial unloading conditions. The microscopic parameters of PB-DEM for marble materials were calibrated using comparison with the previous experimental data. To systematically investigate the mechanical properties and the progressive failure characteristics of pre-fissured marble specimens under the unloading conditions, a series of numerical specimens were simulated. The effects of fissure geometric conditions, initial confining pressures, and unloading rates on the mechanical and failure behaviors were explored via simulations. The present numerical results indicate that peak strength increased as the initial confining pressures increased or the unloading rate decreased. Crack coalescence types and the ultimate failure modes in the pre-fissured marble specimens were significantly affected by the unloading stress paths. The present numerical results provide a better understanding of unloading mechanical and failure characteristics to scientists and engineers in rock mechanics and rock engineering

    Detection and Identification of Estrogen Based on Surface-Enhanced Resonance Raman Scattering (SERRS)

    No full text
    Many studies have shown that it is important to consider the harmful effects of phenolic hormones on the human body. Traditional UV detection has many limitations, so there is a need to develop new detection methods. We demonstrated a simple and rapid surface-enhanced resonance Raman scattering (SERRS) based detection method of trace amounts of phenolic estrogen. As a result of the coupling reaction, there is the formation of strong SERRS activity of azo compound. Therefore, the detection limits are as low as 0.2 × 10−4 for estrone (E1), estriol (E3), and bisphenol A (BPA). This method is universal because each SERRS fingerprint of the azo dyes a specific hormone. The use of this method is applicable for the testing of phenolic hormones through coupling reactions, and the investigation of other phenolic molecules. Therefore, this new method can be used for efficient detection

    Enhanced Catalytic Reduction of 4-Nitrophenol Driven by Fe3O4-Au Magnetic Nanocomposite Interface Engineering: From Facile Preparation to Recyclable Application

    No full text
    In this work, we report the enhanced catalytic reduction of 4-nitrophenol driven by Fe3O4-Au magnetic nanocomposite interface engineering. A facile solvothermal method is employed for Fe3O4 hollow microspheres and Fe3O4-Au magnetic nanocomposite synthesis via a seed deposition process. Complementary structural, chemical composition and valence state studies validate that the as-obtained samples are formed in a pure magnetite phase. A series of characterizations including conventional scanning/transmission electron microscopy (SEM/TEM), Mössbauer spectroscopy, magnetic testing and elemental mapping is conducted to unveil the structural and physical characteristics of the developed Fe3O4-Au magnetic nanocomposites. By adjusting the quantity of Au seeds coating on the polyethyleneimine-dithiocarbamates (PEI-DTC)-modified surfaces of Fe3O4 hollow microspheres, the correlation between the amount of Au seeds and the catalytic ability of Fe3O4-Au magnetic nanocomposites for 4-nitrophenol (4-NP) is investigated systematically. Importantly, bearing remarkable recyclable features, our developed Fe3O4-Au magnetic nanocomposites can be readily separated with a magnet. Such Fe3O4-Au magnetic nanocomposites shine the light on highly efficient catalysts for 4-NP reduction at the mass production level

    Intracisternal tuberculoma: a refractory type of tuberculoma indicating surgical intervention

    No full text
    Abstract Background Central nervous system (CNS) tuberculoma is a rare disease with severe neurological deficits. This retrospective research is to review the data of patients diagnosed as CNS tuberculoma. Surgeries were performed in all patients. The clinical features especially the neurological image and the anatomical characters of the tuberculomas were concerned. Methods Totally 11 patients diagnosed as CNS tuberculoma were admitted in Guangzhou First People’s Hospital (7cases) and Changzheng Hospital (4 cases) during 2006–2015. The data including preoperative condition, neurological imaging, and surgical findings was collected and analyzed. Results The lesions of nine patients (9/11) were totally or subtotally excised and two (2/11) were partially excised. Neurological functions of all patients were improved after surgery without secondary infection. Lesions of nine (9/11) patients preoperatively progressed as a result of paradoxical reaction. Of the 9 patients demonstrated paradoxical progression, all lesions were partially or totally located at the cisterns or the subarachnoid space. Preoperative ATTs lasted 2 to 12 months and tuberculomas were not eliminated. The arachnoid was found thickened and tightly adhered to the lesions during surgeries. Of the 2 cases that paradoxical reaction were excluded, both patients (case 6, intramedullary tuberculoma; case 11, intradural extramedullary tuberculoma) were admitted at onset of the disease. ATTs were preoperatively given for 1 week as neurological deficits aggravated. The tuberculous lesions of CNS or other system showed no obvious change and paradoxical reaction could not be established in both cases. Conclusions Exudates of tuberculosis is usually accumulated in the cisterns and frequently results in the paradoxical formation of tuberculoma. Intracisternal tuberculoma is closely related to paradoxical reaction and refractory to anti-tuberculosis therapy. Micro-surgical excision is safe and effective. Early surgical intervention may be considered in the diagnosis of intracisternal tuberculoma especially when paradoxical reaction participates in the development of tuberculoma
    corecore