85 research outputs found

    Titanium Nitride Film on Sapphire Substrate with Low Dielectric Loss for Superconducting Qubits

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    Dielectric loss is one of the major decoherence sources of superconducting qubits. Contemporary high-coherence superconducting qubits are formed by material systems mostly consisting of superconducting films on substrate with low dielectric loss, where the loss mainly originates from the surfaces and interfaces. Among the multiple candidates for material systems, a combination of titanium nitride (TiN) film and sapphire substrate has good potential because of its chemical stability against oxidization, and high quality at interfaces. In this work, we report a TiN film deposited onto sapphire substrate achieving low dielectric loss at the material interface. Through the systematic characterizations of a series of transmon qubits fabricated with identical batches of TiN base layers, but different geometries of qubit shunting capacitors with various participation ratios of the material interface, we quantitatively extract the loss tangent value at the substrate-metal interface smaller than 8.9×1048.9 \times 10^{-4} in 1-nm disordered layer. By optimizing the interface participation ratio of the transmon qubit, we reproducibly achieve qubit lifetimes of up to 300 μ\mus and quality factors approaching 8 million. We demonstrate that TiN film on sapphire substrate is an ideal material system for high-coherence superconducting qubits. Our analyses further suggest that the interface dielectric loss around the Josephson junction part of the circuit could be the dominant limitation of lifetimes for state-of-the-art transmon qubits

    Oct-4 Expression Maintained Cancer Stem-Like Properties in Lung Cancer-Derived CD133-Positive Cells

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    CD133 (prominin-1), a 5-transmembrane glycoprotein, has recently been considered to be an important marker that represents the subset population of cancer stem-like cells. Herein we report the isolation of CD133-positive cells (LC-CD133+) and CD133-negative cells (LC-CD133−) from tissue samples of ten patients with non-small cell lung cancer (LC) and five LC cell lines. LC-CD133+ displayed higher Oct-4 expressions with the ability to self-renew and may represent a reservoir with proliferative potential for generating lung cancer cells. Furthermore, LC-CD133+, unlike LC-CD133−, highly co-expressed the multiple drug-resistant marker ABCG2 and showed significant resistance to chemotherapy agents (i.e., cisplatin, etoposide, doxorubicin, and paclitaxel) and radiotherapy. The treatment of Oct-4 siRNA with lentiviral vector can specifically block the capability of LC-CD133+ to form spheres and can further facilitate LC-CD133+ to differentiate into LC-CD133−. In addition, knock-down of Oct-4 expression in LC-CD133+ can significantly inhibit the abilities of tumor invasion and colony formation, and increase apoptotic activities of caspase 3 and poly (ADP-ribose) polymerase (PARP). Finally, in vitro and in vivo studies further confirm that the treatment effect of chemoradiotherapy for LC-CD133+ can be improved by the treatment of Oct-4 siRNA. In conclusion, we demonstrated that Oct-4 expression plays a crucial role in maintaining the self-renewing, cancer stem-like, and chemoradioresistant properties of LC-CD133+. Future research is warranted regarding the up-regulated expression of Oct-4 in LC-CD133+ and malignant lung cancer

    Human CIK Cells Loaded with Au Nanorods as a Theranostic Platform for Targeted Photoacoustic Imaging and Enhanced Immunotherapy and Photothermal Therapy

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    How to realize targeted photoacoustic imaging, enhanced immunotherapy, and photothermal therapy of gastric cancer has become a great challenge. Herein, we reported for the first time that human cytokine-induced killer cells (CIK) loaded with gold nanorods were used for targeted photoacoustic imaging, enhanced immunotherapy, and photothermal therapy of gastric cancer. Silica-modified gold nanorods were prepared; then incubated with human cytokine-induced killer cells (CIK), resultant human CIK cells loaded with Au nanorods were evaluated for their cytotoxicity, targeted ability of gastric cancer in vitro and in vivo, immunotherapy, and photothermal therapy efficacy. In vitro cell experiment shows that human CIK cells labeled with gold nanorods actively target gastric cancer MGC803 cells, inhibit growth of MGC803 cells by inducing cell apoptosis, and kill MGC803 cells under low power density near-infrared (NIR) laser treatment (808-nm continuous wave laser, 1.5 W/cm2, 3 min). In vivo experiment results showed that human CIK cells labeled with gold nanorods could target actively and image subcutaneous gastric cancer vessels via photoacoustic imaging at 4 h post-injection, could enhance immunotherapy efficacy by up-regulating cytokines such as IL-1, IL-12, IL-2, IL-4, IL-17, and IFN-γ, and kill gastric cancer tissues by photothermal therapy via direct injection into tumor site under near-infrared (NIR) laser irradiation. High-performance human CIK cells labeled with Au nanorods are a good novel theranostic platform to exhibit great potential in applications such as tumor-targeted photoacoustic imaging, enhanced immunotherapy, and photothermal therapy in the near future

    Revisited and Revised: Is RhoA Always a Villain in Cardiac Pathophysiology?

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    Robust estimation of bacterial cell count from optical density

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    Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

    The receptor binding domain of MERS-CoV: The dawn of vaccine and treatment development

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    The newly emerged Middle East respiratory syndrome coronavirus (MERS-CoV) is becoming another “SARS-like” threat to the world. It has an extremely high death rate (∼50%) as there is no vaccine or efficient therapeutics. The identification of the structures of both the MERS-CoV receptor binding domain (RBD) and its complex with dipeptidyl peptidase 4 (DPP4), raises the hope of alleviating this currently severe situation. In this review, we examined the molecular basis of the RBD-receptor interaction to outline why/how could we use MERS-CoV RBD to develop vaccines and antiviral drugs

    Metabolic gene NR4A1 as a potential therapeutic target for non‐smoking female non‐small cell lung cancer patients

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    Background Although cigarette smoking is considered one of the key risk factors for lung cancer, 15% of male patients and 53% of female patients with lung cancer are non‐smokers. Metabolic changes are critical features of cancer. Therapeutic target identification from a metabolic perspective in non‐small cell lung cancer (NSCLC) tissue of female non‐smokers has long been ignored. Results Based on microarray data retrieved from Affymetrix expression arrays E‐GEOD‐19804, we found that the downregulated genes in non‐smoking female NSCLC patients tended to participate in protein/amino acid and lipid metabolism, while upregulated genes were more involved in protein/amino acid and carbohydrate metabolism. Combining nutrient metabolic co‐expression, protein–protein interaction network construction and overall survival assessment, we identified NR4A1 and TIE1 as potential therapeutic targets for NSCLC in female non‐smokers. To accelerate the drug development for non‐smoking female NSCLC patients, we identified nilotinib as a potential agonist targeting NR4A1 encoded protein by molecular docking and molecular dynamic stimulation. We also show that nilotinib inhibited proliferation and induced senescence of cells in non‐smoking female NSCLC patients in vitro. Conclusions These results not only uncover nutrient metabolic characteristics in non‐smoking female NSCLC patients, but also provide a new paradigm for identifying new targets and drugs for novel therapy for such patients

    Improving the wettability and thermal resistance of polypropylene separators with a thin inorganic-organic hybrid layer stabilized by polydopamine for lithium ion batteries

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    This study aims to improve the wettability and thermal resistance of polypropylene (PP) separators for lithium ion batteries. The PP separator was first coated with polydopamine (PDA) on the basis of mussel-inspired surface chemistry. Then a thin inorganic-organic hybrid layer was immobilized onto the PDA-coated separator via a sol-gel process using tetraethoxysilane (TEOS) solutions. This method does not need any commonly-used polymeric binders because of the unique adhesion behaviour of the PDA intermediate layer, which greatly reduces the thickness of the modification layer and avoids excessive pore blocking. Owing to the incorporation of the hybrid layer, the composite separators showed better affinity with the liquid electrolyte and obvious reduction in thermal shrinkage in comparison to the unmodified separator. And the battery performances, such as interfacial resistance, discharge capacity and C-capacity were all improved after modification. Considering the effective adhesion of PDA onto nearly all kinds of separator/membrane surfaces, this modification strategy can be widely used without causing any obvious damage to the mechanical strength of the unmodified separators/membranes
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