1,199 research outputs found

    Sinteza sustava upravljanja s proporcionalno-derivacijskim regulatorom zasnovana na neizrazitim diferencijalnim jednadžbama

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    This paper reports a fuzzy differential equations approach for the modeling of initial condition uncertainty for a proportional derivative closed-loop control of a direct current motor. Uncertainties are considered on the precision of the sensing devices installed on a driver. The closed-loop system is designed for a plant modeled with fuzzy differential equations. Satisfactory analytic and numerical results for the position regulation problem for ideal case and also considering perturbed initial conditions are reported.U radu je razvijen postupak sinteze proporcionalno-derivacijskog regulatora za upravljanje istosmjernim motorom s neizrazitim (engl. fuzzy) početnim uvjetima zasnovane na neizrazitim diferencijalnim jednadžbama. Pritom je uzeta u obzir nesigurnost određena mjernom preciznošću senzora. U predloženom postupku se zatvoreni regulacijski krug dizajnira korištenjem neizrazitih diferencijalnih jednadžbi. Primjenom projektiranog regulatora na probleme pozicioniranja u idealnom slučaju te u slučaju koji uzima u obzir perturbirane početne uvjete ostvareni su zadovoljavajući analitički i numerički rezultati

    Plasmonic/Magnetic Multifunctional nanoplatform for Cancer Theranostics

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    Cancer is the second leading disease which causes major mortality and morbidity worldwide1 . In cancer therapy, it is crucial to increase the drug specificity and drug efficacy to minimise or completely eradicate significant side-effects on patients2 . Cancer nanotherapeutics overcome many serious drawbacks of chemotherapy such as non-specific targeting, lower efficacy, insolubility of drug moieties in water and oral bioavailability3 . Accordingly, Superparamagnetic Iron Oxide Nanoparticles (SPIONs) are exploited as an important nanomaterial for cancer detection as well as therapeutics4 . Such magnetic nanoparticles (NPs) gained its momentum because of their single-domain ordering along with their large surface to volume ratio (providing large surface area for attachment of biological entities). Hence, this property makes them a suitable candidate as a contrast agent, drug-carrying cargo and hyperthermal agent5

    Optimizing a superconducting radio frequency gun using deep reinforcement learning

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    Superconducting photoelectron injectors are promising for generating highly brilliant pulsed electron beams with high repetition rates and low emittances. Experiments such as ultrafast electron diffraction, experiments at the Terahertz scale, and energy recovery linac applications require such properties. However, optimizing the beam properties is challenging due to the high number of possible machine parameter combinations. This article shows the successful automated optimization of beam properties utilizing an already existing simulation model. To reduce the required computation time, we replace the costly simulation with a faster approximation with a neural network. For optimization, we propose a reinforcement learning approach leveraging the simple computation of the derivative of the approximation. We prove that our approach outperforms standard optimization methods for the required function evaluations given a defined minimum accurac

    Transcriptional Shift Identifies a Set of Genes Driving Breast Cancer Chemoresistance

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    Background Distant recurrences after antineoplastic treatment remain a serious problem for breast cancer clinical management, which threats patients’ life. Systemic therapy is administered to eradicate cancer cells from the organism, both at the site of the primary tumor and at any other potential location. Despite this intervention, a significant proportion of breast cancer patients relapse even many years after their primary tumor has been successfully treated according to current clinical standards, evidencing the existence of a chemoresistant cell subpopulation originating from the primary tumor.Methods/Findings To identify key molecules and signaling pathways which drive breast cancer chemoresistance we performed gene expression analysis before and after anthracycline and taxane-based chemotherapy and compared the results between different histopathological response groups (good-, mid- and bad-response), established according to the Miller & Payne grading system. Two cohorts of 33 and 73 breast cancer patients receiving neoadjuvant chemotherapy were recruited for whole-genome expression analysis and validation assay, respectively. Identified genes were subjected to a bioinformatic analysis in order to ascertain the molecular function of the proteins they encode and the signaling in which they participate. High throughput technologies identified 65 gene sequences which were over-expressed in all groups (P ≤ 0·05 Bonferroni test). Notably we found that, after chemotherapy, a significant proportion of these genes were over-expressed in the good responders group, making their tumors indistinguishable from those of the bad responders in their expression profile (P ≤ 0.05 Benjamini-Hochgerg`s method).Conclusions These data identify a set of key molecular pathways selectively up-regulated in post-chemotherapy cancer cells, which may become appropriate targets for the development of future directed therapies against breast cancer.Thanks are due to the Consejería de Economia, Innovación y Ciencia (CEIC) from the Junta de Andalucía and Fondo Europeo de Desarrollo Regional (FEDER)/Fondo de Cohesión Europeo (FSE) to financial support through the Programa Operativo FEDER/FSE de Andalucía 2007-2013 and the research project CTS-5350. The authors also acknowledge financial support by the PN de I+D+i 2006-2009/ISCIII/Ministerio de Sanidad, Servicios Sociales e Igualdad (Spain) and Fondo Europeo de Desarrollo Regional (FEDER) from the European Union, through the research project PI06/90388

    The BIOMEX experiment on-board the International Space Station: limits of life and detection of biomarkers after exposure to space- and to Mars-like conditions

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    To explore the limits of terrestrial life in space, we have to understand the effects of the space environment on unprotected biological and chemical material, and on the degradation of organic molecules or biomarkers. The exposure platform EXPOSE-R2 on the ISS offer a suitable facility for the exposure of samples of the astrobiological model lichen Circinaria gyrosa, included in the BIOMEX experiment (Biology and Mars Experiment, ESA). During 18 months (2014-2016), the lichens lived in a latent state at space and at simulated Mars-like conditions, to study Mars’ habitability and resistance to space conditions. After the return of the samples in June 2016, initial analysis showed rapid recovery of photosystem II (PSII) activity in the samples exposed exclusively to space vacuum and to Mars-like atmosphere. In contrast, the samples directly exposed to solar UV radiation showed a slow and a lower recovery, in reference to their observed original activity. This tendency was corroborated with the complementary morphological/ultrastructural and biomolecular analyses. Complementary, the biogeochemical variations have been examined with Raman spectroscopy to assess the possible degradation of cell surfaces and pigments which were in contact with terrestrial rocks, and Martian analogue regolith. Identification of the biomarker whewellite (calcium oxalate) and other organic compounds and mineral products of the biological activity of Circinaria gyrosa were detected by Raman Laser. These findings contribute to answer questions on the habitability of Mars, the likelihood of the Lithopanspermia Hypothesis, the capability to detect biomolecules exposed to an extraterrestrial environment by life-detection instruments and will be of relevance for planetary protection issues

    Unsupervised real world knowledge extraction via disentangled variational autoencoders for photon diagnostics

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    We present real world data processing on measured electron time of flight data via neural networks. Specifically, the use of disentangled variational autoencoders on data from a diagnostic instrument for online wavelength monitoring at the free electron laser FLASH in Hamburg. Without a priori knowledge the network is able to find representations of single shot FEL spectra, which have a low signal to noise ratio. This reveals, in a directly human interpretable way, crucial information about the photon properties. The central photon energy and the intensity as well as very detector specific features are identified. The network is also capable of data cleaning, i.e. denoising, as well as the removal of artefacts. In the reconstruction, this allows for identification of signatures with very low intensity which are hardly recognisable in the raw data. In this particular case, the network enhances the quality of the diagnostic analysis at FLASH. However, this unsupervised method also has the potential to improve the analysis of other similar types of spectroscopy dat

    Retinoblastoma seeds: Impact on American Joint Committee on Cancer clinical staging

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    Aim To investigate whether the American Joint Committee on Cancer (AJCC) clinical category cT2b needs to be subclassified by the type and distribution of retinoblastoma (RB) seeding. Methods Multicentre, international registry-based data were collected from RB centres enrolled between January 2001 and December 2013. 1054 RB eyes with vitreous or subretinal seeds from 18 ophthalmic oncology centres, in 13 countries within six continents were analysed. Local treatment failure was defined as the use of secondary enucleation or external beam radiation therapy (EBRT) and was estimated with the Kaplan-Meier method. Results Clinical category cT2b included 1054 eyes. Median age at presentation was 16.0 months. Of these, 428 (40.6%) eyes were salvaged, and 430 (40.8%) were treated with primary and 196 (18.6%) with secondary enucleation. Of the 592 eyes that had complete data for globe salvage analysis, the distribution of seeds was focal in 143 (24.2%) and diffuse in 449 (75.8%). The 5-year Kaplan-Meier cumulative globe-salvage (without EBRT) was 78% and 49% for eyes with focal and diffuse RB seeding, respectively. Cox proportional hazards regression analysis confirmed a higher local treatment failure risk with diffuse seeds as compared with focal seeds (hazard rate: 2.8; p<0.001). There was insufficient evidence to prove or disprove an association between vitreous seed type and local treatment failure risk(p=0.06). Conclusion This international, multicentre, registry-based analysis of RB eyes affirmed that eyes with diffuse intraocular distribution of RB seeds at diagnosis had a higher risk of local treatment failure when compared with focal seeds. Subclassification of AJCC RB category cT2b into focal vs diffuse seeds will improve prognostication for eye salvage.Fil: Tomar, Ankit Singh. New York Eye Cancer Center; Estados UnidosFil: Finger, Paul T.. New York Eye Cancer Center; Estados UnidosFil: Gallie, Brenda. University Of Toronto. Hospital For Sick Children; CanadáFil: Kivelä, Tero. University of Helsinki; Finlandia. Helsinki University Hospital; FinlandiaFil: Mallipatna, Ashwin. University Of Toronto. Hospital For Sick Children; Canadá. Narayana Nethralaya; IndiaFil: Zhang, Chengyue. Beijing Children's Hospital; ChinaFil: Zhao, Junyang. Beijing Children's Hospital; ChinaFil: Wilson, Matthew. University of Tennessee; Estados UnidosFil: Brennan, Rachel. St Jude Children's Research Hospital; Estados UnidosFil: Burges, Michala. University of Tennessee; Estados UnidosFil: Kim, Jonathan. Keck Medical School of the University of Southern California; Estados UnidosFil: Berry, Jesse L.. Children's Hospital Los Angeles; Estados UnidosFil: Jubran, Rima. Childrens Hospital Society of Los Angeles; Estados UnidosFil: Khetan, Vikas. Vitreo Retinal Services; IndiaFil: Ganeshan, Suganeswari. Vitreo Retinal Services; IndiaFil: Yarovoy, Andrey. Fyodorov Eye Microsurgery Federal State Institution; RusiaFil: Yarovaya, Vera. Fyodorov Eye Microsurgery Federal State Institution; RusiaFil: Kotova, Elena. Fyodorov Eye Microsurgery Federal State Institution; RusiaFil: Volodin, Denis. Fyodorov Eye Microsurgery Federal State Institution; RusiaFil: Yousef, Yacoub. King Hussein Cancer Center; JordaniaFil: Nummi, Kalle. University of Helsinki; Finlandia. Helsinki University Hospital; FinlandiaFil: Ushakova, Tatiana L.. N.N. Blokhin Russian Cancer Research Center; Rusia. Russian Academy of Postgraduate Medical Education; RusiaFil: Yugay, Olga V.. N.N. Blokhin Russian Cancer Research Center; RusiaFil: Polyakov, Vladimir G. N.N. Blokhin Russian Cancer Research Center; Rusia. Russian Academy of Sciences; RusiaFil: Ramirez Ortiz, Marco Antonio. Hospital Infantil de Mexico Federico Gomez; MéxicoFil: Esparza Aguiar, Elizabeth. Hospital Infantil de Mexico Federico Gomez; MéxicoFil: Chantada, Guillermo Luis. Gobierno de la Ciudad de Buenos Aires. Hospital de Pediatría "Juan P. Garrahan"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Schaiquevich, Paula Susana. Gobierno de la Ciudad de Buenos Aires. Hospital de Pediatría "Juan P. Garrahan"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Fandiño, Adriana Cristina. Gobierno de la Ciudad de Buenos Aires. Hospital de Pediatría "Juan P. Garrahan"; ArgentinaFil: Yam, Jason C.. The Chinese University of Hong Kong Faculty of Medicine; Hong Kon

    Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

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    This paper presents measurements of the W+μ+νW^+ \rightarrow \mu^+\nu and WμνW^- \rightarrow \mu^-\nu cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

    Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

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    A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV
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