12 research outputs found

    Copolymer of Single-Walled Carbon Nanotubes and Poly(<i>p</i>-phenylene benzobisoxazole)

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    The use of single-walled carbon nanotube (SWNT) copolymers in polymeric formulations may lead to better alignment of fibers, thereby producing higher performance materials. Although poly(p-phenylene benzobisoxazole) (PBO) fibers are some of the strongest organic polymer fibers known, the introduction of SWNTs into the PBO backbone might lead to improvements in their physical properties. Therefore, copolymerization of short (average length 60 nm) carboxylic acid functionalized SWNTs with PBO oligomers was successfully carried out in a mixed solvent of polyphosphoric acid and methanesulfonic acid (MSA) in the presence of P2O5 at 3.3 wt % concentration and 150 °C. The SWNTs were homogeneously distributed throughout the films of copolymerized products, as determined by Raman spectroscopy using the diagnostic radial breathing mode and D and G band emissions. Morphological differences between the copolymerized product and a physical mixture were readily seen using atomic force microscopy. The precipitated copolymerized nanotubes were separated by centrifugation from the MSA suspension of the products of short SWNTs and PBO oligomers. That benzoxazole moieties could be formed between the carboxylic acids of ultra-short (US) SWNTs and o-aminophenol derivatives was established by the condensation of US-SWNTs with o-aminophenols, and subsequent analysis of the products

    DataSheet_1_PRMT5 Inhibition Promotes PD-L1 Expression and Immuno-Resistance in Lung Cancer.pdf

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    Protein arginine transferase 5 (PRMT5) has been implicated as an important modulator of tumorigenesis as it promotes tumor cell proliferation, invasion, and metastasis. Studies have largely focused on PRMT5 regulating intrinsic changes in tumors; however, the effects of PRMT5 on the tumor microenvironment and particularly immune cells are largely unknown. Here we found that targeting PRMT5 by genetic or pharmacological inhibition reduced lung tumor progression in immunocompromised mice; however, the effects were weakened in immunocompetent mice. PRMT5 inhibition not only decreased tumor cell survival but also increased the tumor cell expression of CD274 in vitro and in vivo, which activated the PD1/PD-L1 axis and eliminated CD8+T cell antitumor immunity. Mechanistically, PRMT5 regulated CD274 gene expression through symmetric dimethylation of histone H4R3, increased deposition of H3R4me2s on CD274 promoter loci, and inhibition of CD274 gene expression. Targeting PRMT5 reduced this inhibitory effect and promoted CD274 expression in lung cancer. However, PRMT5 inhibitors represent a double-edged sword as they may selectively kill cancer cells but may also disrupt the antitumor immune response. The combination of PRMT5 inhibition and ani-PD-L1 therapy resulted in an increase in the number and enhanced the function of tumor-infiltrating T cells. Our findings address an unmet clinical need in which combining PRMT5 inhibition with anti-PD-L1 therapy could be a promising strategy for lung cancer treatment.</p

    Soluble Ultra-Short Single-Walled Carbon Nanotubes

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    Soluble, ultra-short (length < 60 nm), carboxylated, single-walled carbon nanotubes (SWNTs) have been prepared by a scalable process. This process, predicated on oleum's (100% H2SO4 with excess SO3) ability to intercalate between individual SWNTs inside SWNT ropes, is a procedure that simultaneously cuts and functionalizes SWNTs using a mixture of sulfuric and nitric acids. The solubility of these ultra-short SWNTs (US-SWNTs) in organic solvents, superacid and water is about 2 wt %. The availability of soluble US-SWNTs could open opportunities for forming high performance composites, blends, and copolymers without inhibiting their processibility

    The method to measure ocular dominance index (ODI).

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    <p>(A) The log(Cst<sub>Mondrian</sub>/Cst<sub>Gabor</sub>) was calculated at response for each trial and each eye was tested 50 times. (B) T-test was used to compare the log ratios collected from the two eyes and the t-value was used as the ODI. Examples of subjects with unclear dominance (ODI < 2, left panel) and clear dominance (ODI ≥ 2, right panel) are shown here. Circles and triangles represent median and mean of the log ratios respectively.</p
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