795 research outputs found

    Infinite dimensional differential games with hybrid controls

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    A two-person zero-sum infinite dimensional differential game of infinite duration with discounted payoff involving hybrid controls is studied. The minimizing player is allowed to take continuous, switching and impulse controls whereas the maximizing player is allowed to take continuous and switching controls. By taking strategies in the sense of Elliott--Kalton, we prove the existence of value and characterize it as the unique viscosity solution of the associated system of quasi-variational inequalities

    Role of scavenger receptor MARCO in particle uptake and lung inflammation

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    Alveolar macrophages (AM) form the first line of defense against chronic inflammation caused by occupational exposure to environmental particulates such as crystalline silica (CSiO2). The chronic inflammatory process triggered by CSiO2 is known to culminate into a fibrotic response called silicosis in the human lungs. Previous studies have indicated the role of membrane glycoproteins called scavenger receptors in binding of environmental particles. The scavenger receptors are classified into different classes (A-H) based on their structure and function. Class A scavenger receptors are critical in uptake of variety of ligands such as bacteria, acetylated lipoproteins and are typically found on macrophages, dendritic and epithelial cells. One of the members of this family is Macrophage receptor with collagenous structure (MARCO). Recent studies have focused on analyzing the interaction between MARCO and inorganic particles such as CSiO2 and titanium dioxide (TiO2). Both in vivo and in vitro binding studies have identified MARCO as a key receptor in CSiO2 uptake and subsequent cytotoxicity in AM from C57Bl/6 mice. Further in vitro studies using a transfected cell line revealed that the 100 amino acid residues long cysteine-rich (SRCR) domain at the C-terminal end of MARCO is required for binding of inorganic particles such as CSiO2, TiO2 and amorphous silica (ASiO2). Moreover, individual particles bind to SRCR domain of MARCO with unique differences and have varying requirements with respect to need for divalent cations. Our studies demonstrate that physiological absence of MARCO in C57Bl/6 mice leads to a more robust inflammatory response following CSiO2 exposure as compared to wild-type mice. The results suggest that diminished clearance of CSiO2 particles from the MARCO-/- lungs exacerbates the lung inflammation. These findings demonstrate that the involvement of different regions of SRCR domain may distinguish downstream events following particle binding. Taken together, these data establish the role of MARCO in uptake of various inorganic particles and elucidate the protective role of MARCO in CSiO2-induced lung inflammation

    SINONASAL VERRUCOUS CARCINOMA Case series and review of literature

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    Verrucous carcinoma is a low grade malignancy and is a variant of squamous cell carcinoma. It is a rare tumour of the Sino nasal tract. The neoplasm occurs in older people usually in the seventh or eighth decade of life. Our cases were sinonasal in origin and patients affected were young.

    Immunolocalization and a study of adhesive properties of PAS IV

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    Cancer Stem Cells and Epithelial Ovarian Cancer

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    The cancer stem cell hypothesis is becoming more widely accepted as a model for carcinogenesis. Tumours are heterogeneous both at the molecular and cellular level, containing a small population of cells that possess highly tumourigenic “stem-cell” properties. Cancer stem cells (CSCs), or tumour-initiating cells, have the ability to self-renew, generate xenografts reminiscent of the primary tumour that they were derived from, and are chemoresistant. The characterisation of the CSC population within a tumour that drives its growth could provide novel target therapeutics against these cells specifically, eradicating the cancer completely. There have been several reports describing the isolation of putative cancer stem cell populations in several cancers; however, no defined set of markers has been identified that conclusively characterises “stem-like” cancer cells. This paper highlights the current experimental approaches that have been used in the field and discusses their limitations, with specific emphasis on the identification and characterisation of the CSC population in epithelial ovarian cancer

    A DRL Approach for RIS-Assisted Full-Duplex UL and DL Transmission: Beamforming, Phase Shift and Power Optimization

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    In this work, a two-stage deep reinforcement learning (DRL) approach is presented for a full-duplex (FD) transmission scenario that does not depend on the channel state information (CSI) knowledge to predict the phase-shifts of reconfigurable intelligent surface (RIS), beamformers at the base station (BS), and the transmit powers of BS and uplink users in order to maximize the weighted sum rate of uplink and downlink users. As the self-interference (SI) cancellation and beamformer design are coupled problems, the first stage uses a least squares method to partially cancel self-interference (SI) and initiate learning, while the second stage uses DRL to make predictions and achieve performance close to methods with perfect CSI knowledge. Further, to reduce the signaling from BS to the RISs, a DRL framework is proposed that predicts quantized RIS phase-shifts and beamformers using 3232 times fewer bits than the continuous version. The quantized methods have reduced action space and therefore faster convergence; with sufficient training, the UL and DL rates for the quantized phase method are 8.14%8.14\% and 2.45%2.45\% better than the continuous phase method respectively. The RIS elements can be grouped to have similar phase-shifts to further reduce signaling, at the cost of reduced performance

    A Central Role for Long Non-Coding RNA in Cancer

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    Long non-coding RNAs (ncRNAs) have been shown to regulate important biological processes that support normal cellular functions. Aberrant regulation of these essential functions can promote tumor development. In this review, we underscore the importance of the regulatory role played by this distinct class of ncRNAs in cancer-associated pathways that govern mechanisms such as cell growth, invasion, and metastasis. We also highlight the possibility of using these unique RNAs as diagnostic and prognostic biomarkers in malignancies
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