349 research outputs found

    Some Relationships between the Analogs of Euler Numbers and Polynomials

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    We construct new twisted Euler polynomials and numbers. We also study the generating functions of the twisted Euler numbers and polynomials associated with their interpolation functions. Next we construct twisted Euler zeta function, twisted Hurwitz zeta function, twisted Dirichlet l-Euler numbers and twisted Euler polynomials at non-positive integers, respectively. Furthermore, we find distribution relations of generalized twisted Euler numbers and polynomials. By numerical experiments, we demonstrate a remarkably regular structure of the complex roots of the twisted q-Euler polynomials. Finally, we give a table for the solutions of the twisted q-Euler polynomials

    Calibrative approaches to protein solubility modeling of a mutant series using physicochemical descriptors

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    A set of physicochemical properties describing a protein of known structure is employed for a calibrative approach to protein solubility. Common hydrodynamic and electrophoretic properties routinely measured in the bio-analytical laboratory such as zeta potential, dipole moment, the second osmotic virial coefficient are first estimated in silico as a function a pH and solution ionic strength starting with the protein crystal structure. The utility of these descriptors in understanding the solubility of a series of ribonuclease Sa mutants is investigated. A simple two parameter model was trained using solubility data of the wild type protein measured at a restricted number of solution pHs. Solubility estimates of the mutants demonstrate that zeta potential and dipole moment may be used to rationalize solubility trends over a wide pH range. Additionally a calibrative model based on the proteinā€™s second osmotic virial coefficient, B22 was developed. A modified DVLO type potential along with a simplified representation of the protein allowed for efficient computation of the second viral coefficient. The standard error of prediction for both models was on the order of 0.3 logĀ S units. These results are very encouraging and demonstrate that these models may be trained with a small number of samples and employed extrapolatively for estimating mutant solubilities

    Making a Step Forward Towards Urban Resilience. The Contribution of Digital Innovation

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    Starting from 'wicked problem' theory as the landmark for framing disaster events in terms of policy issue for city governments, this paper highlights the contribution provided by Big Data analytics and digital innovation in dealing with disaster risks. The research aims at answering the following question: what is the role that 'smart technologies' play in strengthening urban resilience to disaster risks

    IRE1Ī±ā€“XBP1 controls T cell function in ovarian cancer by regulating mitochondrial activity

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    Tumours evade immune control by creating hostile microenvironments that perturb T cell metabolism and effector function 1?4 . However, it remains unclear how intra-tumoral T cells integrate and interpret metabolic stress signals. Here we report that ovarian cancer?an aggressive malignancy that is refractory to standard treatments and current immunotherapies 5?8 ?induces endoplasmic reticulum stress and activates the IRE1Ī±?XBP1 arm of the unfolded protein response 9,10 in T cells to control their mitochondrial respiration and anti-tumour function. In T cells isolated from specimens collected from patients with ovarian cancer, upregulation of XBP1 was associated with decreased infiltration of T cells into tumours and with reduced IFNG mRNA expression. Malignant ascites fluid obtained from patients with ovarian cancer inhibited glucose uptake and caused N-linked protein glycosylation defects in T cells, which triggered IRE1Ī±?XBP1 activation that suppressed mitochondrial activity and IFNĪ³ production. Mechanistically, induction of XBP1 regulated the abundance of glutamine carriers and thus limited the influx of glutamine that is necessary to sustain mitochondrial respiration in T cells under glucose-deprived conditions. Restoring N-linked protein glycosylation, abrogating IRE1Ī±?XBP1 activation or enforcing expression of glutamine transporters enhanced mitochondrial respiration in human T cells exposed to ovarian cancer ascites. XBP1-deficient T cells in the metastatic ovarian cancer milieu exhibited global transcriptional reprogramming and improved effector capacity. Accordingly, mice that bear ovarian cancer and lack XBP1 selectively in T cells demonstrate superior anti-tumour immunity, delayed malignant progression and increased overall survival. Controlling endoplasmic reticulum stress or targeting IRE1Ī±?XBP1 signalling may help to restore the metabolic fitness and anti-tumour capacity of T cells in cancer hosts.Fil: Song, Minkyung. Weill Cornell Medicine; Estados UnidosFil: Sandoval, Tito A.. Weill Cornell Medicine; Estados UnidosFil: Chae, Chang-Suk. Weill Cornell Medicine; Estados UnidosFil: Chopra, Sahil. Weill Cornell Medicine; Estados UnidosFil: Tan, Chen. Weill Cornell Medicine; Estados UnidosFil: Rutkowski, Melanie R.. University of Virginia; Estados UnidosFil: Raundhal, Mahesh. Dana Farber Cancer Institute; Estados Unidos. Harvard Medical School; Estados UnidosFil: Chaurio, Ricardo A.. H. Lee Moffitt Cancer Center & Research Institute; Estados UnidosFil: Payne, Kyle K.. H. Lee Moffitt Cancer Center & Research Institute; Estados UnidosFil: Konrad, Csaba. Weill Cornell Medicine; Estados UnidosFil: Bettigole, Sarah E.. Quentis Therapeutics Inc.; Estados UnidosFil: Shin, Hee Rae. Quentis Therapeutics Inc.; Estados UnidosFil: Crowley, Michael J. P.. Weill Cornell Graduate School of Medical Sciences; Estados UnidosFil: Cerliani, Juan Pablo. Consejo Nacional de Investigaciones CientĆ­ficas y TĆ©cnicas. Instituto de BiologĆ­a y Medicina Experimental. FundaciĆ³n de Instituto de BiologĆ­a y Medicina Experimental. Instituto de BiologĆ­a y Medicina Experimental; ArgentinaFil: Kossenkov, Andrew V.. The Wistar Institute; Estados UnidosFil: Motorykin, Ievgen. Weill Cornell Medicine,; Estados UnidosFil: Zhang, Sheng. Weill Cornell Medicine,; Estados UnidosFil: Manfredi, Giovanni. Weill Cornell Medicine,; Estados UnidosFil: Zamarin, Dmitriy. Memorial Sloan Kettering Cancer Center; Estados UnidosFil: Holcomb, Kevin. Weill Cornell Medicine,; Estados UnidosFil: Rodriguez, Paulo C.. H. Lee Moffitt Cancer Center & Research Institute; Estados UnidosFil: Rabinovich, Gabriel AdriĆ”n. Consejo Nacional de Investigaciones CientĆ­ficas y TĆ©cnicas. Instituto de BiologĆ­a y Medicina Experimental. FundaciĆ³n de Instituto de BiologĆ­a y Medicina Experimental. Instituto de BiologĆ­a y Medicina Experimental; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de QuĆ­mica BiolĆ³gica; ArgentinaFil: Conejo Garcia, Jose R.. H. Lee Moffitt Cancer Center & Research Institute; Estados UnidosFil: Glimcher, Laurie H.. Dana Farber Cancer Institute; Estados Unidos. Harvard Medical School; Estados UnidosFil: Cubillos-Ruiz, Juan R.. Weill Graduate School Of Medical Sciences; Estados Unidos. Weill Graduate School Of Medical Sciences; Estados Unido

    A Transcriptional ā€œScreamā€ Early Response of E. coli Prey to Predatory Invasion by Bdellovibrio

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    We have transcriptionally profiled the genes differentially expressed in E. coli prey cells when predatorily attacked by Bdellovibrio bacteriovorus just prior to prey cell killing. This is a brief, approximately 20ā€“25Ā min period when the prey cell is still alive but contains a Bdellovibrio cell in its periplasm or attached to and penetrating its outer membrane. Total RNA was harvested and labelled 15Ā min after initiating a semi-synchronous infection with an excess of Bdellovibrio preying upon E. coli and hybridised to a macroarray spotted with all predicted ORFs of E. coli. SAM analysis and t-tests were performed on the resulting data and 126 E. coli genes were found to be significantly differentially regulated by the prey upon attack by Bdellovibrio. The results were confirmed by QRT-PCR. Amongst the prey genes upregulated were a variety of general stress response genes, potentially ā€œselfishā€ genes within or near prophages and transposable elements, and genes responding to damage in the periplasm and osmotic stress. Essentially, the presence of the invading Bdellovibrio and the resulting damage to the prey cell elicited a small ā€œtranscriptional screamā€, but seemingly no specific defensive mechanism with which to counter the Bdellovibrio attack. This supports other studies which do not find Bdellovibrio resistance responses in prey, and bodes well for its use as a ā€œliving antibioticā€

    Involvement of Cox-2 in the metastatic potential of chemotherapy-resistant breast cancer cells

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    <p>Abstract</p> <p>Background</p> <p>A major problem with the use of current chemotherapy regimens for several cancers, including breast cancer, is development of intrinsic or acquired drug resistance, which results in disease recurrence and metastasis. However, the mechanisms underlying this drug resistance are unknown. To study the molecular mechanisms underlying the invasive and metastatic activities of drug-resistant cancer cells, we generated a doxorubicin-resistant MCF-7 breast cancer cell line (MCF-7/DOX).</p> <p>Methods</p> <p>We used MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assays, flow cytometry assays, DNA fragmentation assays, Western blot analysis, cell invasion assays, small interfering RNA (siRNA) transfection, reverse transcription-polymerase chain reaction, experimental lung metastasis models, and gelatin and fibrinogen/plasminogen zymography to study the molecular mechanism of metastatic activities in MCF-7/DOX cells.</p> <p>Results</p> <p>We found that MCF-7/DOX acquired invasive activities. In addition, Western blot analysis showed increased expression of epidermal growth factor receptor (EGFR) and Cox-2 in MCF-7/DOX cells. Inhibition of Cox-2, phosphoinositide 3-kinase (PI3K)/Akt, or mitogen-activated protein kinase (MAPK) pathways effectively inhibited the invasive activities of MCF-7/DOX cells. Gelatin and fibrinogen/plasminogen zymography analysis showed that the enzymatic activities of matrix metalloproteinase-2 (MMP-2), MMP-9, and urokinase-type plasminogen activator were markedly higher in MCF-7/DOX cells than in the MCF-7 cells. <it>In vitro </it>invasion assays and mouse models of lung metastasis demonstrated that MCF-7/DOX cells acquired invasive abilities. Using siRNAs and agonists specific for prostaglandin E (EP) receptors, we found that EP1 and EP3 played important roles in the invasiveness of MCF-7/DOX cells.</p> <p>Conclusions</p> <p>We found that the invasive activity of MCF-7/DOX cells is mediated by Cox-2, which is induced by the EGFR-activated PI3K/Akt and MAPK pathways. In addition, EP1 and EP3 are important in the Cox-2-induced invasion of MCF-7/DOX cells. Therefore, not only Cox-2 but also EP1 and EP3 could be important targets for chemosensitization and inhibition of metastasis in breast cancers that are resistant to chemotherapy.</p
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