74 research outputs found

    Applications of Schauder’s Fixed Point Theorem to Semipositone Singular Differential Equations

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    We study the existence of positive periodic solutions of second-order singular differential equations. The proof relies on Schauder’s fixed point theorem. Our results generalized and extended those results contained in the studies by Chu and Torres (2007) and Torres (2007) . In some suitable weak singularities, the existence of periodic solutions may help

    High Payload Dual Therapeutic-Imaging Nanocarriers for Triggered Tumor Delivery

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    The in vitro and in vivo characterization of an optimized formulation of nanoparticles (NPs) loaded with a high content of dexamethasone palmitate (DEX-P), a chemotherapeutic adjuvant that decreases interstitial fluid pressure in tumors, and 111In, a signaling agent, is described. These NPs are uniform in size and composition. Single photon emission computed tomography imaging demonstrates significant tumor uptake of 111In-labeled DEX-P NPs in tumor-bearing mice. As with many nanoparticle-based drug delivery systems, significant liver accumulation is observed. Assessment of liver histology and blood tests show no apparent hepatic or renal toxicity of the DEX-P NPs. Conversion of DEX-P to DEX occurs when DEX-P NPs are incubated with mouse plasma, human tumor homogenate and ascites from tumor bearing mice, but not with human plasma. This conversion is slower in plasma from Es1e(−/−)/SCID mice, a potential alternative animal model that better mimics humans; however, plasma from these mice are not completely devoid of esterase activity. The difference between blood and tumor esterase activity in humans facilitates the delivery of DEX-P NPs to tumors and the release of dexamethasone by an esterase trigger

    Pathogenic Pseudorabies Virus, China, 2012

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    In 2012, an unprecedented large-scale outbreak of disease in pigs in China caused great economic losses to the swine industry. Isolates from pseudorabies virus epidemics in swine herds were characterized. Evidence confirmed that the pathogenic pseudorabies virus was the etiologic agent of this epidemic

    Pt-decorated nanoporous gold for glucose electrooxidation in neutral and alkaline solutions

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    Exploiting electrocatalysts with high activity for glucose oxidation is of central importance for practical applications such as glucose fuel cell. Pt-decorated nanoporous gold (NPG-Pt), created by depositing a thin layer of Pt on NPG surface, was proposed as an active electrode for glucose electrooxidation in neutral and alkaline solutions. The structure and surface properties of NPG-Pt were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), and cyclic voltammetry (CV). The electrocatalytic activity toward glucose oxidation in neutral and alkaline solutions was evaluated, which was found to depend strongly on the surface structure of NPG-Pt. A direct glucose fuel cell (DGFC) was performed based on the novel membrane electrode materials. With a low precious metal load of less than 0.3 mg cm-2 Au and 60 μg cm-2 Pt in anode and commercial Pt/C in cathode, the performance of DGFC in alkaline is much better than that in neutral condition

    MASALAH-MASALAH PEMBELAJARAN YANG DIHADAPI WIDYAISWARA : Studi Kasus Pada Lembaga Diktat Pemda Tk.I Propinsi Bengkulu

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    <div><p>Rat strains differ dramatically in their susceptibility to mammary carcinogenesis. On the assumption that susceptibility genes are conserved across mammalian species and hence inform human carcinogenesis, numerous investigators have used genetic linkage studies in rats to identify genes responsible for differential susceptibility to carcinogenesis. Using a genetic backcross between the resistant Copenhagen (Cop) and susceptible Fischer 344 (F344) strains, we mapped a novel mammary carcinoma susceptibility (<i>Mcs30</i>) locus to the centromeric region on chromosome 12 (LOD score of ∼8.6 at the D12Rat59 marker). The <i>Mcs30</i> locus comprises approximately 12 Mbp on the long arm of rat RNO12 whose synteny is conserved on human chromosome 13q12 to 13q13. After analyzing numerous genes comprising this locus, we identified <i>Fry</i>, the rat ortholog of the furry gene of <i>Drosophila melanogaster,</i> as a candidate <i>Mcs</i> gene. We cloned and determined the complete nucleotide sequence of the 13 kbp <i>Fry</i> mRNA. Sequence analysis indicated that the <i>Fry</i> gene was highly conserved across evolution, with 90% similarity of the predicted amino acid sequence among eutherian mammals. Comparison of the <i>Fry</i> sequence in the Cop and F344 strains identified two non-synonymous single nucleotide polymorphisms (SNPs), one of which creates a putative, de novo phosphorylation site. Further analysis showed that the expression of the <i>Fry</i> gene is reduced in a majority of rat mammary tumors. Our results also suggested that FRY activity was reduced in human breast carcinoma cell lines as a result of reduced levels or mutation. This study is the first to identify the <i>Fry</i> gene as a candidate <i>Mcs</i> gene. Our data suggest that the SNPs within the <i>Fry</i> gene contribute to the genetic susceptibility of the F344 rat strain to mammary carcinogenesis. These results provide the foundation for analyzing the role of the human <i>FRY</i> gene in cancer susceptibility and progression.</p></div

    Applications of Schauder&apos;s Fixed Point Theorem to Semipositone Singular Differential Equations

    No full text
    We study the existence of positive periodic solutions of second-order singular differential equations. The proof relies on Schauder&apos;s fixed point theorem. Our results generalized and extended those results contained in the studies by Chu and Torre

    Comparison between hot-gas bypass defrosting and reverse-cycle defrosting methods on an air-to-water heat pump

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    Frost build-up blocks the gap between fins and decreases the airflow rate, and the heating capacity and COP of air-source heat pump become lower. The reverse-cycle defrosting (RCD) and hot-gas bypass defrosting HGBD are the two common methods of frost removal. The comparison between the RCD and HGBD methods on one heat pump were not found by authors up to now. This paper compared the dynamic characteristics during the RCD and HGBD periods on one medium air-to-water heat pump of 55 kW. The feasibility of the HGBD method without heat provided to evaporate the liquid refrigerant after melting frost, which was supposed in the danger of the compressor liquid slugging, was especially discussed. The results showed the liquid refrigerant leaving the air cooled coils for the HGBD method was trapped in the suction accumulator and flashed into the saturated gas by the compressor pumping action, and no compressor liquid slugging happened in our tests. The HGBD time was much longer than the RCD time. The amenity for the HGBD method was better than that for the RCD method, due to lower refrigerant noise, smaller indoor temperature fluctuation, and no cold blowing. The suction superheat and discharge superheat for the HGBD method were lower than those for the RCD method. The HGBD could overcome the main disadvantages of the RCD method and deserved the further investigation.Heat pump Hot-gas bypass defrosting Reverse-cycle defrosting
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