33 research outputs found
Molecular mechanism of alveolar macrophage polarization and cell communication with alveolar epithelial cell
The Development of Preschool Education Achievements, Problems and Policy Recommendations of Tibet
This paper shows the development of preschool education in Tibet through analyzing the statistical data from Statistical Yearbook of National Education, Statistical Yearbook of National Education Funding and Statistical Yearbook of Tibet and field investigations. It is found that the preschool education in Tibet has developed rapidly for the support of government, and achieved the following development effectiveness: education resources have increased; preschool education funding increased rapidly; the development tends to be balanced between urban and rural areas; bilingual education developed rapidly, and more attention is paid to education equality. However, there are still many problems to be solved in the future. The study has indicated that the quality of preschool education in ethnic areas is low, the local government does not play an active role in developing preschool education and the preschool education is unsuitable for local features. Therefore, more attention should be paid to the preschool education in ethnic areas as well as to the quality of the quantity and the theory researches. The government should also develop the bilingual education in Tibetan scientifically.
Removal of Disinfection By-Products Precursor (Humic Acid) by Graphene-Silica Composites
Graphene-silica (RGO-SiO2) was successfully synthesized by a simple hydrothermal method. The composites were used to study the adsorption properties of humic acid and disinfection by-product precursors in natural surface water. Compared with reduced graphene oxide (RGO), the specific surface area of the composites doped with silica (SiO2) increased by 31.2% to 259.43 m2/g. RGO-SiO2 could achieve 66.91% adsorption of humic acid (HA), while the maximum adsorption of HA on RGO-SiO2 reached 925.91 mg/g. The adsorption and removal rates of HA by RGO-SiO2 were significantly higher than those of RGO. The whole adsorption process was in accordance with the quasi-secondary kinetic model, the Langmuir isothermal adsorption model. RGO-SiO2 has good adsorption performance for organic matter of different water qualities. RGO-SiO2 has a better removal ability for hydrophobic organics than hydrophilic and nitrogenous organics. The adsorbent was reusable, and the organic removal efficiency of RGO-SiO2 decreased insignificantly after four cycles
Removal of Disinfection By-Products Precursor (Humic Acid) by Graphene-Silica Composites
Graphene-silica (RGO-SiO2) was successfully synthesized by a simple hydrothermal method. The composites were used to study the adsorption properties of humic acid and disinfection by-product precursors in natural surface water. Compared with reduced graphene oxide (RGO), the specific surface area of the composites doped with silica (SiO2) increased by 31.2% to 259.43 m2/g. RGO-SiO2 could achieve 66.91% adsorption of humic acid (HA), while the maximum adsorption of HA on RGO-SiO2 reached 925.91 mg/g. The adsorption and removal rates of HA by RGO-SiO2 were significantly higher than those of RGO. The whole adsorption process was in accordance with the quasi-secondary kinetic model, the Langmuir isothermal adsorption model. RGO-SiO2 has good adsorption performance for organic matter of different water qualities. RGO-SiO2 has a better removal ability for hydrophobic organics than hydrophilic and nitrogenous organics. The adsorbent was reusable, and the organic removal efficiency of RGO-SiO2 decreased insignificantly after four cycles
Subinhibitory Concentrations of Allicin Decrease Uropathogenic Escherichia coli (UPEC) Biofilm Formation, Adhesion Ability, and Swimming Motility
Uropathogenic Escherichia coli (UPEC) biofilm formation enables the organism to avoid the host immune system, resist antibiotics, and provide a reservoir for persistent infection. Once the biofilm is established, eradication of the infection becomes difficult. Therefore, strategies against UPEC biofilm are urgently required. In this study, we investigated the effect of allicin, isolated from garlic essential oil, on UPEC CFT073 and J96 biofilm formation and dispersal, along with its effect on UPEC adhesion ability and swimming motility. Sub-inhibitory concentrations (sub-MICs) of allicin decreased UPEC biofilm formation and affected its architecture. Allicin was also capable of dispersing biofilm. Furthermore, allicin decreased the bacterial adhesion ability and swimming motility, which are important for biofilm formation. Real-time quantitative polymerase chain reaction (RT-qPCR) revealed that allicin decreased the expression of UPEC type 1 fimbriae adhesin gene fimH. Docking studies suggested that allicin was located within the binding pocket of heptyl α-d-mannopyrannoside in FimH and formed hydrogen bonds with Phe1 and Asn135. In addition, allicin decreased the expression of the two-component regulatory systems (TCSs) cognate response regulator gene uvrY and increased the expression of the RNA binding global regulatory protein gene csrA of UPEC CFT073, which is associated with UPEC biofilm. The findings suggest that sub-MICs of allicin are capable of affecting UPEC biofilm formation and dispersal, and decreasing UPEC adhesion ability and swimming motility
Cloning, Characterization and Expression Pattern Analysis of a Cytosolic Copper/Zinc Superoxide Dismutase (SaCSD1) in a Highly Salt Tolerant Mangrove (Sonneratia alba)
Mangroves are critical marine resources for their remarkable ability to tolerate seawater. Antioxidant enzymes play an especially significant role in eliminating reactive oxygen species and conferring abiotic stress tolerance. In this study, a cytosolic copper/zinc superoxide dismutase (SaCSD1) cDNA of Sonneratia alba, a mangrove species with high salt tolerance, was successfully cloned and then expressed in Escherichia coli Rosetta-gami (designated as SaCSD1). SaCSD1 comprised a complete open reading frame (ORF) of 459 bp which encoded a protein of 152 amino acids. Its mature protein is predicted to be 15.32 kDa and the deduced isoelectric point is 5.78. SaCSD1 has high sequence similarity (85%–90%) with the superoxide dismutase (CSD) of some other plant species. SaCSD1 was expressed with 30.6% yield regarding total protein content after being introduced into the pET-15b (Sma I) vector for expression in Rosetta-gami and being induced with IPTG. After affinity chromatography on Ni-NTA, recombinant SaCSD1 was obtained with 3.2-fold purification and a specific activity of 2200 U/mg. SaCSD1 showed good activity as well as stability in the ranges of pH between 3 and 7 and temperature between 25 and 55 °C. The activity of recombinant SaCSD1 was stable in 0.25 M NaCl, Dimethyl Sulphoxide (DMSO), glycerol, and chloroform, and was reduced to a great extent in β-mercaptoethanol, sodium dodecyl sulfate (SDS), H2O2, and phenol. Moreover, the SaCSD1 protein was very susceptive to pepsin digestion. Real-time Quantitative Polymerase Chain Reaction (PCR) assay demonstrated that SaCSD1 was expressed in leaf, stem, flower, and fruit organs, with the highest expression in fruits. Under 0.25 M and 0.5 M salt stress, the expression of SaCSD1 was down-regulated in roots, but up-regulated in leaves
LY2874455 suppressed inflammation though autophagy pathway.
(A) Autophagy inhibitor reversed the effect of LY2874455 on ROS-reduction in LPS-stimulated macrophages. RAW264.7 cells were stained with ROS-probe DCFH-DA after treatment with LPS (20 ng/ml), LY2874455 (2 μm), and wortmannin (100 nM) as indicated for 24 h. Quantitative measurement of cellular ROS was performed by flow cytometry. (B, C) Autophagy inhibitor reversed the effect of LY2874455 in LPS-stimulated macrophages. The expression of inflammatory cytokine genes (iNOS and IL-6) was checked by qRT-PCR in RAW264.7 cells treated as (A). (D, E) The expression of inflammatory cytokine IL-6 and iNOS was checked by qRT-PCR in PMs as treated as in (A). (F) Autophagy deficiency reversed the effect of LY2874455 in inflammatory macrophages. WT or ATG7 knock out (ATG7-KO) RAW264.7 cells were treated with LPS (20 ng/ml) and LY2874455 (2 μm) for 24 h. The expression of iNOS and IL-6 was checked by qRT-PCR and expressed as fold changes compared to values in WT cells. (G) p62 knock down reversed the effect of LY2874455 in inflammatory macrophages. Control (sh-CTL, control shRNA) or p62 knockdown (sh-p62, p62-targeting shRNA) RAW264.7 cells were treated with LPS (20 ng/ml) and LY2874455 (2 μm) for 24 h. The expression of iNOS and IL-6 was checked by qRT-PCR and expressed as fold changes compared to values in control cells. (H–J) The enhanced production of proinflammatory factors in autophagy-deficient macrophages was suppressed by immunoproteasome inhibitor ONX-0914. WT or ATG7 knockout (ATG7-KO) RAW264.7 cells treated with LPS (20 ng/ml) and ONX-0914 (1 μm). The expression of iNOS and inflammatory cytokine genes (IL-6 and TNF-α) was checked by qRT-PCR. *: P P P P S1 Data. iNOS, inducible nitric oxide synthase; LPS, lipopolysaccharide; PM, peritoneal macrophage; qRT-PCR, quantitative real-time polymerase chain reaction; ROS, reactive oxygen species; WT, wild type.</p
Biokinetics of nanoparticles and susceptibility to particulate exposure in a murine model of cystic fibrosis.
BACKGROUND
Persons with cystic fibrosis (CF) are at-risk for health effects from ambient air pollution but little is known about the interaction of nanoparticles (NP) with CF lungs. Here we study the distribution of inhaled NP in a murine CF model and aim to reveal mechanisms contributing to adverse effects of inhaled particles in susceptible populations.
METHODS
Chloride channel defective CftrTgH (neoim) Hgu mice were used to analyze lung function, lung distribution and whole body biokinetics of inhaled NP, and inflammatory responses after intratracheal administration of NP. Distribution of 20-nm titanium dioxide NP in lungs was assessed on ultrathin sections immediately and 24 h after a one-hour NP inhalation. NP biokinetics was deduced from total and regional lung deposition and from whole body translocation of inhaled 30-nm iridium NP within 24 h after aerosol inhalation. Inflammatory responses were assessed within 7 days after carbon NP instillation.
RESULTS
Cftr mutant females had moderately reduced lung compliance and slightly increased airway resistance compared to wild type mice. We found no genotype dependent differences in total, regional and head deposition or in secondary-organ translocation of inhaled iridium NP. Titanium dioxide inhalation resulted in higher NP uptake by alveolar epithelial cells in Cftr mutants. Instillation of carbon NP induced a comparable acute and transient inflammatory response in both genotypes. The twofold increase of bronchoalveolar lavage (BAL) neutrophils in Cftr mutant compared to wild type mice at day 3 but not at days 1 and 7, indicated an impaired capacity in inflammation resolution in Cftr mutants. Concomitant to the delayed decline of neutrophils, BAL granulocyte-colony stimulating factor was augmented in Cftr mutant mice. Anti-inflammatory 15-hydroxyeicosatetraenoic acid was generally significantly lower in BAL of Cftr mutant than in wild type mice.
CONCLUSIONS
Despite lacking alterations in lung deposition and biokinetics of inhaled NP, and absence of significant differences in lung function, higher uptake of NP by alveolar epithelial cells and prolonged, acute inflammatory responses to NP exposure indicate a moderately increased susceptibility of lungs to adverse effects of inhaled NP in Cftr mutant mice and provides potential mechanisms for the increased susceptibility of CF patients to air pollution
Real-time SERS monitoring anticancer drug release along with SERS/MR imaging for pH-sensitive chemo-phototherapy
In situ and real-time monitoring of responsive drug release is critical for the assessment of pharmacodynamics in chemotherapy. In this study, a novel pH-responsive nanosystem is proposed for real-time monitoring of drug release and chemo-phototherapy by surface-enhanced Raman spectroscopy (SERS). The Fe3O4@Au@Ag nanoparticles (NPs) deposited graphene oxide (GO) nanocomposites with a high SERS activity and stability are synthesized and labeled with a Raman reporter 4-mercaptophenylboronic acid (4-MPBA) to form SERS probes (GO-Fe3O4@Au@Ag-MPBA). Furthermore, doxorubicin (DOX) is attached to SERS probes through a pH-responsive linker boronic ester (GO-Fe3O4@Au@Ag-MPBA-DOX), accompanying the 4-MPBA signal change in SERS. After the entry into tumor, the breakage of boronic ester in the acidic environment gives rise to the release of DOX and the recovery of 4-MPBA SERS signal. Thus, the DOX dynamic release can be monitored by the real-time changes of 4-MPBA SERS spectra. Additionally, the strong T2 magnetic resonance (MR) signal and NIR photothermal transduction efficiency of the nanocomposites make it available for MR imaging and photothermal therapy (PTT). Altogether, this GO-Fe3O4@Au@Ag-MPBA-DOX can simultaneously fulfill the synergistic combination of cancer cell targeting, pH-sensitive drug release, SERS-traceable detection and MR imaging, endowing it great potential for SERS/MR imaging-guided efficient chemo-phototherapy on cancer treatment