106 research outputs found

    Study of Distributed Controlling Techniques in Micro Grids

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    : Microgrids are moving from laboratory benches and pilot demonstration sites to commercial markets thanks to technological improvements, lower costs, proven track record and growing recognition of their benefits. They are used to improve the reliability and resilience of power grids, manage the addition of distributed clean energy resources such as wind and solar photovoltaic (PV), reduce fossil fuel emissions, and provide power in areas not supported by a centralized electrical system. The infrastructure is provided. This article presents the control techniques for DC micro-network, distributed control, and description of micro-grid systems

    Predisposing Factors in Post Endoscopic Retrograde Cholangiopancreatography Pancreatitis

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    Objective: To ascertain the prevalence of risk factors in pancreatitis after endoscopic retrograde cholangiopancreatography at Isra University Hospital in Hyderabad. Methodology: This descriptive case series study was done at the gastroenterology department of Isra University Hospital, Hyderabad, from September 2018 to March 2020. Patients aged 18 to 50 years, both genders, and diagnosed with post-ERCP pancreatitis were included. All the patients were undergoing an ERCP procedure. The procedure was done under conscious sedation or propofol where needed. The serum amylase level was assessed in all patients at 4 hours. Patients had been considered to have post-ERCP pancreatitis if they developed new or worsening pain of abdomen and had a threefold increase in serum amylase. All the cases were assessed regarding risk factors in pancreatitis after endoscopic retrograde cholangiopancreatography. All the data was recorded in the proforma. Results: The mean age of the patients was 42.7 years. The majority of the patients (65.47%) were females and 32.90% were males. The mean duration of pancreatitis was 3.1 days. Sphincter of Oddi dysfunction was found in 17.1% of cases. Precut papillotomy was done in 18(23.7%) cases. Repeated pancreatic duct injury was seen in 10(13.2%) cases. No significant difference was found in the effect of modifiers on predisposing factors in post-endoscopic retrograde cholangiopancreatography pancreatitis, p-values were almost insignificant. Conclusion: Cannulation attempts, Sphincter of Oddi dysfunction, precut papillotomy, repeated pancreatic duct injection, and female gender were observed to be the predisposing factors in post-endoscopic retrograde cholangiopancreatography pancreatitis

    A peptide fragment from the human COX3 protein disrupts association of Mycobacterium tuberculosisvirulence proteins ESAT-6 and CFP10, inhibits mycobacterial growth and mounts protective immune response

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    BACKGROUND: Tuberculosis (TB) is one of the most prevalent infectious diseases affecting millions worldwide. The currently available anti-TB drugs and vaccines have proved insufficient to contain this scourge, necessitating an urgent need for identification of novel drug targets and therapeutic strategies. The disruption of crucial protein-protein interactions, especially those that are responsible for virulence in Mycobacterium tuberculosis – for example the ESAT-6:CFP10 complex – are a worthy pursuit in this direction. METHODS: We therefore sought to improvise a method to attenuate M. tuberculosis while retaining the latter’s antigenic properties. We screened peptide libraries for potent ESAT-6 binders capable of dissociating CFP10 from ESAT-6. We assessed the disruption by a peptide named HCL2, of the ESAT-6:CFP10 complex and studied its effects on mycobacterial survival and virulence. RESULTS: We found that HCL2, derived from the human cytochrome c oxidase subunit 3 (COX3) protein, disrupts ESAT-6:CFP10 complex, binds ESAT-6 potently, disintegrates bacterial cell wall and inhibits extracellular as well as intracellular mycobacterial growth. In addition, an HCL2 expressing M. tuberculosis strain induces both Th1 and Th17 host protective responses. CONCLUSIONS: Disruption of ESAT-6:CFP10 association could, therefore, be an alternate method for attenuating M. tuberculosis, and a possible route towards future vaccine generation

    Expression of the ARPC4 subunit of human Arp2/3 severely affects mycobacterium tuberculosis growth and suppresses immunogenic response in murine macrophages

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    Background: The search for molecules against Mycobacterium tuberculosis is urgent. The mechanisms facilitating the intra-macrophage survival of Mycobacterium tuberculosis are as yet not entirely understood. However, there is evidence showing the involvement of host cell cytoskeleton in every step of establishment and persistence of mycobacterial infection. Methodology/Principal Findings: Here we show that expression of ARPC4, a subunit of the Actin related protein 2/3 (Arp2/3) protein complex, severely affects the pathogen’s growth. TEM studies display shedding of the mycobacterial outer-coat. Furthermore, in infected macrophages, mycobacteria expressing ARPC4 were cleared off at a much faster rate, and were unable to mount a pro-inflammatory cytokine response. The translocation of ARPC4-expressing mycobacteria to the lysosome of the infected macrophage was also impaired. Additionally, the ARPC4 subunit was shown to interact with Rv1626, an essential secretory mycobacterial protein. Real-time PCR analysis showed that upon expression of ARPC4 in mycobacteria, Rv1626 expression is downregulated as much as six-fold. Rv1626 was found to also interact with mammalian cytoskeleton protein, Arp2/3, and enhance the rate of actin polymerization. Conclusions/Significance: With crystal structures for Rv1626 and ARPC4 subunit already known, our finding lays out the effect of a novel molecule on mycobacteria, and represents a viable starting point for developing potent peptidomimetics

    Extracellular Vesicles in Triple–Negative Breast Cancer: Immune Regulation, Biomarkers, and Immunotherapeutic Potential

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    Triple–negative breast cancer (TNBC) is an aggressive subtype accounting for ~10–20% of all human BC and is characterized by the absence of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) amplification. Owing to its unique molecular profile and limited targeted therapies, TNBC treatment poses significant challenges. Unlike other BC subtypes, TNBC lacks specific molecular targets, rendering endocrine therapies and HER2–targeted treatments ineffective. The chemotherapeutic regimen is the predominant systemic treatment modality for TNBC in current clinical practice. However, the efficacy of chemotherapy in TNBC is variable, with response rates varying between a wide range of patients, and the emerging resistance further adds to the difficulties. Furthermore, TNBC exhibits a higher mutational burden and is acknowledged as the most immunogenic of all BC subtypes. Consequently, the application of immune checkpoint inhibition has been investigated in TNBC, yielding promising outcomes. Recent evidence identified extracellular vesicles (EVs) as an important contributor in the context of TNBC immunotherapy. In view of the extraordinary ability of EVs to transfer bioactive molecules, such as proteins, lipids, DNA, mRNAs, and small miRNAs, between the cells, EVs are considered a promising diagnostic biomarker and novel drug delivery system among the prospects for immunotherapy. The present review provides an in–depth understanding of how EVs influence TNBC progression, its immune regulation, and their contribution as a predictive biomarker for TNBC. The final part of the review focuses on the recent key advances in immunotherapeutic strategies for better understanding the complex interplay between EVs and the immune system in TNBC and further developing EV–based targeted immunotherapies

    A standardized protocol for genomic DNA isolation from Terminalia arjuna for genetic diversity analysis

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    For studying genetic diversity in natural populations of Terminalia , a medicinal plant, our attempts to isolate high quality DNA using several previously reported protocols and even modifications were unsuccessful. We therefore combined CTAB based isolation, and column based purification step, to isolate DNA from Terminalia arjuna . The DNA isolated using this standardized protocol was high in quality and suitable for restriction digestion and generation of random amplification of polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP)

    Quasinormal modes and holographic correlators in a crunching AdS geometry

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    We calculate frequency space holographic correlators in an asymptotically AdS crunching background, dual to a relevant deformation of the M2-brane CFT placed in de Sitter spacetime. For massless bulk scalars, exploiting the connection to a solvable supersymmetric quantum mechanical problem, we obtain the exact frequency space correlator for the dual operator in the deformed CFT. Controlling the shape of the crunching surface in the Penrose diagram by smoothly dialling the deformation from zero to infinity, we observe that in the large deformation limit the Penrose diagram becomes a `square', and the exact holographic correlators display striking similarities to their counterparts in the BTZ black hole and its higher dimensional generalisations. We numerically determine quasinormal poles for relevant and irrelevant operators, and find an intricate pattern of these in the complex frequency plane. In the case of relevant operators, the deformation parameter has an infinite sequence of critical values, each one characterised by a pair of poles colliding and moving away from the imaginary frequency axis with increasing deformation. In the limit of infinite deformation all scalar operators have identical quasinormal spectra. We compare and contrast our strongly coupled de Sitter QFT results with strongly coupled thermal correlators from AdS black holes

    Probing crunching AdS cosmologies

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    Holographic gravity duals of deformations of CFTs formulated on de Sitter spacetime contain FRW geometries behind a horizon, with cosmological big crunch singularities. Using a specific analytically tractable solution within a particular single scalar truncation of N=8 supergravity on AdS_4, we first probe such crunching cosmologies with spacelike radial geodesics that compute spatially antipodal correlators of large dimension boundary operators. At late times, the geodesics lie on the FRW slice of maximal expansion behind the horizon. The late time two-point functions factorise, and when transformed to the Einstein static universe, they exhibit a temporal non-analyticity determined by the maximal value of the scale factor a_max. Radial geodesics connecting antipodal points necessarily have de Sitter energy E < a_max, while geodesics with E > a_max terminate at the crunch, the two categories of geodesics being separated by the maximal expansion slice.The spacelike crunch singularity is curved ``outward'' in the Penrose diagram for the deformed AdS backgrounds, and thus geodesic limits of the antipodal correlators do not directly probe the crunch. Beyond the geodesic limit, we point out that the scalar wave equation, analytically continued into the FRW patch, has a potential which is singular at the crunch along with complex WKB turning points in the vicinity of the FRW crunch. We then argue that the frequency space Green's function has a branch point determined by a_max which corresponds to the lowest quasinormal frequency
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