668 research outputs found

    Factors related to children’s caries: a structural equation modeling approach

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    BACKGROUND: Dental caries among preschool children is highly prevalent in many less-developed countries. METHODS: A model which explored the factors related to children’s dental caries was tested in this study using structural equation modeling. Caregivers of children aged 5 years were surveyed on their socioeconomic status, and their oral health knowledge, attitudes and practices. In addition, information on their children’s oral health practices, dental insurance and dental service utilization were collected. Examination of caries was conducted on all children who returned fully completed questionnaires. RESULTS: The results showed that socioeconomic factors influenced children’s oral health practices through the impact of caregivers’ oral health knowledge and practices; that caregivers’ oral health knowledge affected children’s oral health practices through the influence of caregivers’ oral health attitudes and practices; and finally, that children’s oral health practices were linked directly to their caries. CONCLUSION: The findings have important applications for promoting policies aimed at advancing children’s oral health

    Enhanced hydrophilicity and antibacterial activity of PVDF ultrafiltration membrane using Ag3PO4/TiO2 nanocomposite against E. coli

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    Ag3PO4/TiO2, nanocomposite was fabricated by an in situ precipitation method and then blended into poly(vinylidene fluoride) (PVDF) casting solution to prepare the ultrafiltration membrane via wet phase inversion technique. The water flux and bovine serum albumin (BSA) rejection rate of membrane were investigated; meanwhile, the ultrafiltration membrane morphologies and structural properties were analyzed using scanning electron microscope (SEM) and X-ray diffraction. Compared with the control membrane, the permeate performance of blended membranes was improved while possessing a steady BSA retention due to enhanced hydrophilicity. Mechanical tests revealed that the modified membranes exhibited a larger tensile strength and breakage elongation. SEM images and the halo zone testing were employed to assess the antibacterial performances of the nanocomposite membranes against Escherichia coli. The antibacterial tests confirmed that the modified membranes showed an effective antibacterial property against E. coli

    Synthesis, characterization, and solution structure of all-conjugated polyelectrolyte diblock copoly(3- hexylthiophene)s

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    We report on a new class of all-conjugated polyelectrolyte diblock copoly(3-hexylthiophene)s, poly(3-hexylthiophene)-b-poly [3-[6-(N-methylimidazolium)hexyl]thiophene] (P3HT-b-P3MHT). The polyelectrolyte diblock copolymers were prepared by a catalyst-transfer Kumada polycondensation followed by quaternization of the bromohexyl side groups of the poly[3-(6-bromohexyl)thiophene] block with Nmethylimidazole. The obtained diblock copolymers have well-defined block ratios, narrow polydispersity indices, and high regioregularity. Their characterization as well as the thermal, crystalline, and optical properties, and self-assembly behavior have been investigated in detail. Transmission electron microscopy (TEM) provided evidence for solvent-induced self-assembly. A series of morphologies including short or long nanowires and nanorings could be obtained depending on the selectivity of solvents toward different blocks and the block ratios

    The influence of rotating magnetic field on the welding arc motion status

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    A device generating rotating magnetic field is designed on the bas is of the mechanism of a rotating magnetic field. A rotating magnetic field and electric arc jointing together simulation is studied in this paper to elaborate arc characteristics and behavior under the action of a rotating magnetic field. The rotation radius of the arc are inversely proportional to the rotational frequency of the magnetic field. It is proportional to the field current. Due to constraint function of its own magnetic field of underwater wet welding arc. The influence on the underwater welding arc is smaller than the air welding arc while the magnetic field rotation frequency and magnetic field intensity is changed

    LaZnB5O10, the first lanthanum zinc borate

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    Lanthanum zinc penta­borate, LaZnB5O10, was synthesized by flux-supported solid-state reaction. It is a member of the LnMB5O10 (Ln = rare earth ion and M = divalent metal ion) structure type. The crystal shows a three-dimensional structure constructed from two-dimensional {[B5O10]5−}n layers with the lanthanum (coordination number nine) and zinc (coordination number six) ions filling in the inter­layers

    Anti-Hepatitis B Virus X Protein in Sera Is One of the Markers of Development of Liver Cirrhosis and Liver Cancer Mediated by HBV

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    Hepatitis B virus X protein (HBx) plays a crucial role in the development of hepatocellular carcinoma (HCC). However, the significance of circulating antibody to hepatitis B virus X antigen (anti-HBx) in sera remains unclear. In the present study, we examined the titers of anti-HBx (IgG) in the sera from 173 patients with chronic hepatitis B (CHB), 106 liver cirrhosis (LC), and 61 HCC by enzyme-linked immunosorbent assay (ELISA), respectively. Our data showed that the positive rates of anti-HBx were higher in sera of LC (40.6%) and HCC (34.4%) than those of CHB (10.4%), P < .05. In all 40 patients with anti-HBx+ out of 340 patients, 39 (97.5%) were HBsAg/HBeAg/anti-HBc+ and 1 (2.5%) was anti-HBs+ (P < .01), suggesting that anti-HBx in sera is a marker of HBV replication rather than a protective antibody. Thus, our findings reveal that circulating anti-HBx in sera is one of the markers of development of LC and HCC mediated by HBV

    The Anti-Non-Small Cell Lung Cancer Cell Activity by a mTOR Kinase Inhibitor PQR620

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    In non-small-cell lung carcinoma (NSCLC), aberrant activation of mammalian target of rapamycin (mTOR) contributes to tumorigenesis and cancer progression. PQR620 is a novel and highly-potent mTOR kinase inhibitor. We here tested its potential activity in NSCLC cells. In primary human NSCLC cells and established cell lines (A549 and NCI-H1944), PQR620 inhibited cell growth, proliferation, and cell cycle progression, as well as cell migration and invasion, while inducing significant apoptosis activation. PQR620 disrupted assembles of mTOR complex 1 (mTOR-Raptor) and mTOR complex 2 (mTOR-Rictor-Sin1), and blocked Akt, S6K1, and S6 phosphorylations in NSCLC cells. Restoring Akt-mTOR activation by a constitutively-active Akt1 (S473D) only partially inhibited PQR620-induced cytotoxicity in NSCLC cells. PQR620 was yet cytotoxic in Akt1/2-silenced NSCLC cells, supporting the existence of Akt-mTOR-independent mechanisms. Indeed, PQR620 induced sphingosine kinase 1 (SphK1) inhibition, ceramide production and oxidative stress in primary NSCLC cells. In vivo studies demonstrated that daily oral administration of a single dose of PQR620 potently inhibited primary NSCLC xenograft growth in severe combined immune deficient mice. In PQR620-treated xenograft tissues, Akt-mTOR inactivation, apoptosis induction, SphK1 inhibition and oxidative stress were detected. In conclusion, PQR620 exerted potent anti-NSCLC cell activity via mTOR-dependent and -independent mechanisms
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