1,400 research outputs found

    Quantum electrodynamics in a whispering-gallery microcavity coated with a polymer nanolayer

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    Quasi-transverse-electric and -transverse-magnetic fundamental whispering gallery modes in a polymer-coated silica microtoroid are theoretically investigated and demonstrated to possess very high-quality factors. The existence of a nanometer-thickness layer not only evidently reduces the cavity mode volume but also draws the maximal electric field's position of the mode to the outside of the silica toroid, where single quantum dots or nanocrystals are located. Both effects result in a strongly enhanced coherent interaction between a single dipole (for example, a single defect center in a diamond crystal) and the quantized cavity mode. Since the coated microtoroid is highly feasible and robust in experiments, it may offer an excellent platform to study strong-coupling cavity quantum electrodynamics, quantum information, and quantum computation

    Bryostatin I inhibits growth and proliferation of pancreatic cancer cells via suppression of NF-κB activation

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    Purpose: To evaluate the effect of bryostatin I on proliferation of pancreatic cancer cells as well as tumor growth in mice tumor xenograft model.Methods: Activation of NF-κB was evaluated by preparing nuclear material extract using nuclear extract kit (Carlsbad, CA, USA) followed by enzyme-linked immunosorbent assay (ELISA). Mice were injected with 3 x 105 MIApaCa 2 cells in 100 μL volume of PBS. The animals in the treatment group were injected with 50 μg/kg of bryostatin 1 daily for 1 month in the morning whereas those in the untreated group received an equal volume of normal saline.Results: Treatment of the MIApaCa 2 cells with bryostatin I caused a significant reduction in the activity of NF-κB in nucleoplasm (p = 0.0002). The increase in the concentration of bryostatin I from 10 to 50 μM reduced MIApaCa 2 cell proliferation from 87 to 26 %. Bryostatin I treatment also led to increase in the proportion of cells in M1 phase with subsequent reduction in sub-G1 phase of cell cycle. Examination of the cell lysates revealed a higher expression level of cleaved caspase-8 in bryostatin Itreated MIApaCa 2 cells. Mean tumor diameter in the treatment and untreated groups was 5.34 ± 2.16 and 19.45 ± 5.71 mm, respectively, after 2 months of treatment (p < 0.0002). The mean weight of the tumors in the treatment and untreated groups was 123.67 ± 22.56 and 939.14 ± 213.51 mg, respectively, after 2 months of treatment.Conclusion: Bryostatin I inhibits growth and proliferation of pancreatic cancer through inhibition of NF- κB expression, and therefore, needs to be further investigated for therapeutic application in pancreatic cancer.Keywords: Bryostatin I, NF-κB expression, Proliferation, Apoptosis, Pancreatic cancer, Tumor volum

    Inhibition of nuclear factor-kappa B enhances the tumor growth of ovarian cancer cell line derived from a low-grade papillary serous carcinoma in p53-independent pathway

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    Background: NF-kB can function as an oncogene or tumor suppressor depending on cancer types. The role of NF-kB in low-grade serous ovarian cancer, however, has never been tested. We sought to elucidate the function of NF-kB in the low-grade serous ovarian cancer. Methods: The ovarian cancer cell line, HOC-7, derived from a low-grade papillary serous carcinoma. Introduction of a dominant negative mutant, IkBαM, which resulted in decrease of NF-kB function in ovarian cancer cell lines. The transcription ability, tumorigenesis, cell proliferation and apoptosis were observed in derivative cell lines in comparison with parental cells. Results: Western blot analysis indicated increased expression of the anti-apoptotic proteins Bcl-xL and reduced expression of the pro-apoptotic proteins Bax, Bad, and Bid in HOC-7/IĸBαM cell. Further investigations validate this conclusion in KRAS wildtype cell line SKOV3. Interesting, NF-kB can exert its pro-apoptotic effect by activating mitogen-activated protein kinase (MAPK) phosphorylation in SKOV3 ovarian cancer cell, whereas opposite changes detected in p-MEK in HOC-7 ovarian cancer cell, the same as some chemoresistant ovarian cancer cell lines. In vivo animal assay performed on BALB/athymic mice showed that injection of HOC-7 induced subcutaneous tumor growth, which was completely regressed within 7 weeks. In comparison, HOC-7/IĸBαM cells caused sustained tumor growth and abrogated tumor regression, suggesting that knock-down of NF-kB by IĸBαM promoted sustained tumor growth and delayed tumor regression in HOC-7 cells. Conclusion: Our results demonstrated that NF-kB may function as a tumor suppressor by facilitating regression of low grade ovarian serous carcinoma through activating pro-apoptotic pathways

    Generation of Multicellular Tumor Spheroids with Microwell-Based Agarose Scaffolds for Drug Testing

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    Three dimensional multicellular aggregate, also referred to as cell spheroid or microtissue, is an indispensable tool for in vitro evaluating antitumor activity and drug efficacy. Compared with classical cellular monolayer, multicellular tumor spheroid (MCTS) offers a more rational platform to predict in vivo drug efficacy and toxicity. Nevertheless, traditional processing methods such as plastic dish culture with nonadhesive surfaces are regularly time-consuming, laborious and difficult to provide uniform-sized spheroids, thus causing poor reproducibility of experimental data and impeding high-throughput drug screening. In order to provide a robust and effective platform for in vitro drug evaluation, we present an agarose scaffold prepared with the template containing uniform-sized micro-wells in commercially available cell culture plates. The agarose scaffold allows for good adjustment of MCTS size and large-scale production of MCTS. Transparent agarose scaffold also allows for monitoring of spheroid formation under an optical microscopy. The formation of MCTS from MCF-7 cells was prepared using different-size-well templates and systematically investigated in terms of spheroid growth curve, circularity, and cell viability. The doxorubicin cytotoxicity against MCF-7 spheroid and MCF-7 monolayer cells was compared. The drug penetration behavior, cell cycle distribution, cell apoptosis, and gene expression were also evaluated in MCF-7 spheroid. The findings of this study indicate that, compared with cellular monolayer, MCTS provides a valuable platform for the assessment of therapeutic candidates in an in vivo-mimic microenvironment, and thus has great potential for use in drug discovery and tumor biology research

    Genetic influences on creativity: an exploration of convergent and divergent thinking

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    Previous studies on the genetic basis of creativity have mainly focused on the biological mechanisms of divergent thinking, possibly limiting the exploration of possible candidate genes. Taking a cognition-based perspective, the present study investigated the genetic basis for both the divergent and the convergent thinking components of creativity. A total of 321 Chinese university students were recruited to complete the Guildford Unusual Using Test (UUT) for divergent thinking capability and the Remote Associates Test (RAT) for convergent thinking capability. The polymorphism of rs2576037 in KATNAL2 was related to the fluency and originality component scores of UUT, and the polymorphism of rs5993883 in COMT, rs362584 in SNAP25 was related to the RAT performance. These effects remained significant after considering the influence of age, gender and intelligence. Our results provide new evidence for the genetic basis of creativity and reveal the important role of gene polymorphisms in divergent and convergent thinking

    Aldose reductase regulates microglia/macrophages polarization through the cAMP response element-binding protein after spinal cord injury in mice.

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    Inflammatory reactions are the most critical pathological processes occurring after spinal cord injury (SCI). Activated microglia/macrophages have either detrimental or beneficial effects on neural regeneration based on their functional polarized M1/M2 subsets. However, the mechanism of microglia/macrophage polarization to M1/M2 at the injured spinal cord environment remains unknown. In this study, wild-type (WT) or aldose reductase (AR)-knockout (KO) mice were subjected to SCI by a spinal crush injury model. The expression pattern of AR, behavior tests for locomotor activity, and lesion size were assessed at between 4 h and 28 days after SCI. We found that the expression of AR is upregulated in microglia/macrophages after SCI in WT mice. In AR KO mice, SCI led to smaller injury lesion areas compared to WT. AR deficiency-induced microglia/macrophages induce the M2 rather than the M1 response and promote locomotion recovery after SCI in mice. In the in vitro experiments, microglia cell lines (N9 or BV2) were treated with the AR inhibitor (ARI) fidarestat. AR inhibition caused 4-hydroxynonenal (HNE) accumulation, which induced the phosphorylation of the cAMP response element-binding protein (CREB) to promote Arg1 expression. KG501, the specific inhibitor of phosphorylated CREB, could cancel the upregulation of Arg1 by ARI or HNE stimulation. Our results suggest that AR works as a switch which can regulate microglia by polarizing cells to either the M1 or the M2 phenotype under M1 stimulation based on its states of activity. We suggest that inhibiting AR may be a promising therapeutic method for SCI in the future

    Layer combination design and effect evaluation of phase change cooling asphalt pavement

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    Asphalt mixture is a temperature sensitive material. With the change of external environment temperature, asphalt pavement is prone to temperature-related diseases. Adding phase change material (PCM) to asphalt pavement to adjust pavement temperature is one of the effective methods at present. At present, there are many types of research on PCMs, but the research on PCMs added to the pavement structure is very scarce. In this paper, through the temperature test of rutting plate specimens with different layer combinations, the cooling effect of pavement structure combinations with PCMs added to different layers (upper layer, middle layer, and bottom layer) in pavement structure under different illumination times are discussed. Through the self-designed environmental simulation box, the real-time monitoring of the temperature of different layers in the pavement structure is realized. The cooling effect between different layers in different phase change pavement structure combinations is analyzed, and compared with each layer of ordinary pavement structure, and the best addition method is obtained for phase change materials, which provides a certain reference for the construction and specific application of PCM asphalt pavement, and made important contributions to the development of asphalt cooling pavement. The results show that the PCM can effectively reduce the temperature of each layer of the pavement structure. Under different illumination durations, the cooling effect of the samples with PCM in the upper layer was the worst. The samples with phase change material in the middle layer had the best cooling effect in the upper and middle layers of the pavement. The addition of phase change material to both the upper and middle layers had the most obvious cooling effect on the lower layer of the pavement. Therefore, combined with the comprehensive consideration of economy and cooling effect, the comprehensive cooling effect of adding PCMs to the middle surface layer is the best. It is recommended to add phase change materials to the middle surface layer during asphalt cooling pavement construction
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