56 research outputs found
Preparation and Characterization of Folate Targeting Magnetic Nanomedicine Loaded with Cisplatin
We used Aldehyde sodium alginate (ASA) as modifier to improve surfactivity and stability of magnetic nanoparticles, and folate acid (FA) as targeting molecule. Fe3O4 nanoparticles were prepared by chemical coprecipitation method. FA was activated and coupled with diaminopolyethylene glycol (NH2-PEG-NH2). ASA was combined with Fe3O4 nanoparticles, and FA-PEG was connected with ASA by Schiff’s base formation. Then Cl- in cisplatin was replaced by hydroxyl group in ASA, and FA- and ASA-modified cisplatin-loaded magnetic nanomedicine (CDDP-FA-ASA-MNPs) was prepared. This nanomedicine was characterized by transmission electron microscopy, dynamic lighterring scattering, phase analysis light scattering and vibrating sample magnetometer. The uptake of magnetic nanomedicine by nasopharyngeal and laryngeal carcinoma cells with folate receptor positive or negative expression were observed by Prussian blue iron stain and transmission electron microscopy. We found that CDDP-FA-ASA-MNPs have good water-solubility and stability. Mean diameter of Fe3O4 core was 8.17 ± 0.24 nm, hydrodynamic diameters was 110.90±1.70 nm, and zeta potential was -26.45±1.26 mV. Maximum saturation magnetization was 22.20 emu/g. CDDP encapsulation efficiency was 49.05±1.58% (mg/mg), and drug loading property was 14.31±0.49% (mg/mg). In vitro, CDDP-FA-ASA-MNPs were selectively taken up by HNE-1 cells and Hep-2 cells, which express folate receptor positively
Genome-wide identification and functional exploration of the legume lectin genes in Brassica napus and their roles in Sclerotinia disease resistance
As one of the largest classes of lectins, legume lectins have a variety of desirable features such as antibacterial and insecticidal activities as well as anti-abiotic stress ability. The Sclerotinia disease (SD) caused by the soil-borne fungus Sclerotinia sclerotiorum is a devastating disease affecting most oil crops such as Brassica napus. Here, we identified 130 legume lectin (LegLu) genes in B. napus, which could be phylogenetically classified into seven clusters. The BnLegLu gene family has been significantly expanded since the whole-genome duplication (WGD) or segmental duplication. Gene structure and conserved motif analysis suggested that the BnLegLu genes were well conserved in each cluster. Moreover, relative to those genes only containing the legume lectin domain in cluster VI–VII, the genes in cluster I–V harbored a transmembrane domain and a kinase domain linked to the legume lectin domain in the C terminus. The expression of most BnLegLu genes was relatively low in various tissues. Thirty-five BnLegLu genes were responsive to abiotic stress, and 40 BnLegLu genes were strongly induced by S. sclerotiorum, with a most significant up-regulation of 715-fold, indicating their functional roles in SD resistance. Four BnLegLu genes were located in the candidate regions of genome-wide association analysis (GWAS) results which resulted from a worldwide rapeseed population consisting of 324 accessions associated with SD. Among them, the positive role of BnLegLus-16 in SD resistance was validated by transient expression in tobacco leaves. This study provides important information on BnLegLu genes, particularly about their roles in SD resistance, which may help targeted functional research and genetic improvement in the breeding of B. napus
Retrieval of atmospheric CFC-11 and CFC-12 from high-resolution FTIR observations at Hefei and comparisons with other independent datasets
peer reviewedAbstract. Synthetic halogenated organic chlorofluorocarbons (CFCs) play an important role in stratospheric ozone depletion and contribute significantly to the greenhouse effect. In this work, the mid-infrared solar spectra measured by ground-based high-resolution Fourier transform infrared spectroscopy (FTIR) were used to retrieve atmospheric CFC-11 (CCl3F) and CFC-12 (CCl2F2) at Hefei, China. The CFC-11 columns observed from January 2017 to December 2020 and CFC-12 columns from September 2015 to December 2020 show a similar annual decreasing trend and seasonal cycle, with an annual rate of -0.47±0.06 % yr−1 and -0.68±0.03 % yr−1, respectively. So the decline rate of CFC-11 is significantly lower than that of CFC-12. CFC-11 total columns were higher in summer, and CFC-12 total columns were higher in summer and autumn. Both CFC-11 and CFC-12 total columns reached the lowest in spring. Further, FTIR data of NDACC (Network for the Detection of Atmospheric Composition Change) candidate station Hefei were compared with the ACE-FTS (Atmospheric Chemistry Experiment Fourier transform spectrometer) satellite data, WACCM (Whole Atmosphere Community Climate Model) data, and the data from other NDACC-IRWG (InfraRed Working Group) stations (St. Petersburg, Jungfraujoch, and Réunion). The mean relative difference between the vertical profiles observed by FTIR and ACE-FTS is -5.6±3.3 % and 4.8±0.9 % for CFC-11 and CFC-12 for an altitude of 5.5 to 17.5 km, respectively. The results demonstrate that our FTIR data agree relatively well with the ACE-FTS satellite data. The annual decreasing rate of CFC-11 measured from ACE-FTS and calculated by WACCM is -1.15±0.22 % yr−1 and -1.68±0.18 % yr−1, respectively. The interannual decreasing rates of atmospheric CFC-11 obtained from ACE-FTS and WACCM data are higher than that from FTIR observations. Also, the annual decreasing rate of CFC-12 from ACE-FTS and WACCM is -0.85±0.15 % yr−1 and -0.81±0.05 % yr−1, respectively, close to the corresponding values from the FTIR measurements. The total columns of CFC-11 and CFC-12 at the Hefei and St. Petersburg stations are significantly higher than those at the Jungfraujoch and Réunion (Maïdo) stations, and the two values reached the maximum in local summer or autumn and the minimum in local spring or winter at the four stations. The seasonal variability at the three stations in the Northern Hemisphere is higher than that at the station in the Southern Hemisphere
High-frequency elastic moduli and internal frictions of Zr41.2Ti13.8Cu12.5Ni10Be22.5 bulk metallic glass during glass transition and crystallization
Temperature dependent Young's modulus, shear modulus and the related internal frictions of Zr41.2Ti13.8Cu12.5Ni10Be22.5 (Vit-1) bulk metallic glass (BMG) were measured by using the modified piezoelectric ultrasonic composite oscillator technique (M-PUCOT) at longitudinal and torsional resonance under several tens of kilohertz, respectively. An irreversible internal friction peak accompanied by a very small modulus relaxation (about 10%) are observed near the onset crystallization temperatures T-x in each resonance mode, and the peak values in these two modes are almost the same, indicating that the supercooled liquid region (SLR) is far from liquid state under high frequency vibration with micro strain (similar to 10(-7)) amplitude. What is more, the internal friction peak value decreases obviously after a preheating process to SLR (similar to 410 degrees C) and the final values of moduli are proportional to the crystallinity. All these interesting phenomena during the glass transition and crystallization can well be interpreted through a three-parameter anelastic solid phenomenological model
Preparation and Characterization of Folate-Targeted Fe 3
A novel folate (FA) receptor-targeted superparamagnetic Fe3O4 nanoparticles (SPIONs) codelivering cisplatin (CDDP) and tissue factor pathway inhibitor-2 (TFPI-2) plasmid DNA (pDNA) was constructed. The core shell nanocomposites (FA-PEG-PEI@SPION-CDDP-TFPI-2) were composed of superparamagnetic Fe3O4 core that binds CDDP and TFPI-2 shell that combines with folate-polyethylene glycol-polyethyleneimine (FA-PEG-PEI) via electrostatic interaction. The shell containing FA-PEG-PEI and TFPI-2 plasmid was synthesized through amidation reaction and electrostatic adsorption and the core containing SPION-CDDP was modified by aldehyde sodium alginate. Proton nuclear magnetic resonance and Fourier transform infrared spectra on FA-PEG-PEI polymers showed characteristic peaks of various metabolites in corresponding frequency. Transmission electron microscopy image of FA-PEG-PEI@SPION-CDDP-TFPI-2 nanoparticles demonstrated a near-monodisperse spherical morphology, while dynamic light scattering studies indicated an intensity-average diameter of 149.5 nm. Zeta potential was 14.89 ± 1.83 mv and the final concentration of loaded CDDP was 100 ug/ml. Gel electrophoresis data showed that the nanocomposite would protect TFPI-2 pDNA from being digested by DNases. Compared with CNE-2 cells, the good targetability and better gene transfection efficiency (57.9%) were detected by Prussian blue iron stain and fluorescence analysis in HNE-1 cells in vitro. The results suggested the potential application of FA-PEG-PEI@SPION-CDDP-TFPI-2 as a multifunctional anticancer nanomedicine on targeting therapy for FR positive NPC
Mycobacterium tuberculosis Rv3402c enhances mycobacterial survival within macrophages and modulates the host pro-inflammatory cytokines production via NF-kappa B/ERK/p38 signaling.
Intracellular survival plays a central role in the pathogenesis of Mycobacterium tuberculosis, a process which depends on an array of virulence factors to colonize and replicate within the host. The M. tuberculosis iron regulated open reading frame (ORF) rv3402c, encoding a conserved hypothetical protein, was shown to be up-regulated upon infection in both human and mice macrophages. To explore the function of this ORF, we heterologously expressed the rv3402c gene in the non-pathogenic fast-growing Mycobacterium smegmatis strain, and demonstrated that Rv3402c, a cell envelope-associated protein, was able to enhance the intracellular survival of recombinant M. smegmatis. Enhanced growth was not found to be the result of an increased resistance to intracellular stresses, as growth of the Rv3402c expressing strain was unaffected by iron depletion, H2O2 exposure, or acidic conditions. Colonization of macrophages by M. smegmatis expressing Rv3402c was associated with substantial cell death and significantly greater amount of TNF-α and IL-1β compared with controls. Rv3402c-induced TNF-α and IL-1β production was found to be mediated by NF-κB, ERK and p38 pathway in macrophages. In summary, our study suggests that Rv3402c delivered in a live M. smegmatis vehicle can modify the cytokines profile of macrophage, promote host cell death and enhance the persistence of mycobacterium within host cells
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