291 research outputs found

    Displaced vertices and long-lived charged particles in the NMSSM with right-handed sneutrinos

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    We study LHC signatures of displaced vertices and long-lived charged particles within the context of the Next-to-Minimal Supersymmetric Standard Model with right-handed (RH) sneutrinos. In this construction the RH neutrino can be produced directly from Higgs decays or in association with a RH sneutrino when the latter is the lightest supersymmetric particle. The RH neutrino is generally long-lived, since its decay width is proportional to the neutrino Yukawa, a parameter which is predicted to be small. The RH neutrino late decay can therefore give rise to displaced vertices at the LHC, which can be identified through the decay products, which involve two leptons (2ℓ + https://static-content.springer.com/image/art%3A10.1007%2FJHEP05%282014%29035/MediaObjects/13130_2014_8145_Figa_HTML.gifT ) or a lepton with two jets (ℓjj). We simulate this signal for the current LHC configuration (a centre of mass of 8 TeV and an integrated luminosity of LL = 20 fb−1), and a future one (13 TeV and LL = 100 fb−1). We show that a region of the parameter space of this model can be probed and that the RH neutrino mass can be reconstructed from the end-point of the two-lepton invariant mass distribution or the central value of the mass distribution for two jets plus one lepton. Another exotic signature of this construction is the production of a long-lived stau. If the stau is the next-to-lightest supersymmetric particle, it can decay through diagrams involving the small neutrino Yukawa, and would escape the detector leaving a characteristic trail. We also simulate this signal for various benchmark points and show that the model can be within the reach of the future run of the LHC

    El efecto fotoacústico como técnica de medida de conductividad térmica

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    Ponencia presentada en las IV Jornadas de Jóvenes Investigadores, celebradas en Madrid el 9 de julio de 2015.La conductividad térmica es una propiedad de los materiales de gran importancia en muchos campos de investigación como por ejemplo, la termoelectricidad. Sin embargo, es una magnitud muy compleja de determinar, especialmente a escala nanométrica. En este trabajo se ha desarrollado un sistema experimental basado en el efecto fotoacústico capaz de medir conductividad térmica de materiales de muy diferentes estructuras, dimensiones y propiedades térmicas. La técnica fotoacústica es una técnica óptica de no contacto que permite obtener la conductividad térmica de diferentes tipos de estructuras desde materiales en volumen, películas delgadas, estructuras multicapa o incluso matrices de nanohilos. En esta técnica, una radiación periódica modulada calienta la muestra de tal forma que el aire en contacto con la superficie de la muestra se caliente y enfría y por tanto se expande y se contrae periódicamente de forma similar a un pistón térmico. Este efecto provoca ondas acústicas que son detectadas por un micrófono. Comparando la onda incidente proveniente del láser con la onda acústica registrada, se pueden extraer las propiedades térmicas de la muestra. El análisis de la señal depende del tipo de muestra que se esté analizando. En este trabajo, se usan dos tipos diferentes de normalización. En el caso de estructuras multicapa, la muestra es iluminada en configuración frontal (o de reflexión) y la señal es normalizada con una muestra de referencia que permite eliminar la contribución de la celda fotoacústica. Para el cálculo de la conductividad térmica se emplea un modelo multicapa desarrollado por Hu et al. En el caso de muestras en volumen, la normalización se lleva a cabo midiendo la muestra tanto en configuración de reflexión como transmisión. El sistema experimental, que se muestra en la figura, fue desarrollado en el laboratorio y consiste en una celda fotoacústica hecha de metacrilato diseñada de tal forma que se evitan posibles resonancias acústicas. En este trabajo, se muestran las capacidades y límites de la técnica junto con algunos resultados experimentales que se han obtenido.Peer Reviewe

    Structural, Vibrational, and Elastic Properties of Yttrium Orthoaluminate Nanoperovskite at High Pressures

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    "This document is the Accepted Manuscript version of a Published Work that appeared in final form in The Journal of Physical Chemistry C, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://pubs.acs.org/page/policy/articlesonrequest/index.html."[EN] The structural and vibrational properties of nanocrystalline yttrium orthoaluminate perovskite (YAlO3) under compression have been experimentally studied. Experimental results have been compared to ab initio simulations of. bulk YAlO3, in the framework of the density functional theory. Furthermore, they have been complemented with an ab initio study of its elastic properties at different pressures. Calculated total and partial phonon density of states have allowed us to understand the contribution of the different atoms and structural units, YO12 dodecahedra and AlO6 octahedra, to the vibrational modes. The calculated infrared-active modes and their pressure dependence are also reported. Finally, the pressure dependences of the, elastic constants and the mechanical stability of the perovskite structure have been analyzed in detail, showing that this phase is mechanically stable until 92 GPa. In fact, experimental results up to 30 GPa show no evidence of any phase transition. A previously proposed possible phase transition in YAlO3 above 80 GPa is also discussed.This research was partially supported by MINECO (MAT2013-46649-C4-2/3/4-P, MAT2015-71070-REDC, and MAT2016-75586-C4-2/3/4-P) and by EU-FEDER funds. M.A.H.-R. thanks MINECO for an FPI grant (BES-2014-068666).Hernández-Rodríguez, M.; Monteseguro, V.; Lozano-Gorrín, A.; Manjón, F.; González-Platas, J.; Rodríguez-Hernández, P.; Muñoz, A.... (2017). Structural, Vibrational, and Elastic Properties of Yttrium Orthoaluminate Nanoperovskite at High Pressures. The Journal of Physical Chemistry C. 121(28):15353-15367. https://doi.org/10.1021/acs.jpcc.7b04245S15353153671212

    Validation of miR-1228-3p as Housekeeping for MicroRNA Analysis in Liquid Biopsies from Colorectal Cancer Patients

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    BACKGROUND: Circulating microRNA (miRNA) analysis is a growing research field. However, it usually requires an endogenous control or housekeeping (HK) in order to normalize expression of specific miRNAs throughout different samples. Unfortunately, no adequate HK for circulating miRNA analysis is still known in the colorectal cancer (CRC) context whereas several have been suggested. Hence, our aims were to validate the previously suggested miR-1228-3p as HK for CRC studies, to compare its suitability with the widely used miR-16-5p, and to evaluate the influence of hemolysis on both miRNAs. METHODS: We analyzed by quantitative reverse-transcription polymerase chain reaction (qRT-PCR) the expression of miR-1228-3p, miR-16-5p and the spike-in cel-miR-39 in a set of 297 plasmas (92 CRC, 101 advanced adenomas -AA-, and 100 controls) and 213 serum samples (59 CRC, 74 AA and 80 controls). We also analyzed both miRNAs depending on the hemolysis degree in 7 plasmas and 31 serums. RESULTS: Levels of miR-1228-3p and miR-16-5p did not show significant differences between groups although miR-16-5p exhibited more variability in plasma and serum samples. Importantly, the combination of cel-miR-39 and miR-1228-3p was the most stable one. Moreover, we observed that miR-16-5p was significantly influenced by hemolysis in contrast with miR-1228-3p that exhibited no correlation with this confounding factor in both biofluids. CONCLUSION: MiR-1228-3p has been validated as an adequate endogenous control for circulating miRNA analysis in CRC and AA liquid biopsies

    Plasma MicroRNA Signature Validation for Early Detection of Colorectal Cancer

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    OBJECTIVES: Specific microRNA (miRNA) signatures in biological fluids can facilitate earlier detection of the tumors being then minimally invasive diagnostic biomarkers. Circulating miRNAs have also emerged as promising diagnostic biomarkers for colorectal cancer (CRC) screening. In this study, we investigated the performance of a specific signature of miRNA in plasma samples to design a robust predictive model that can distinguish healthy individuals from those with CRC or advanced adenomas (AA) diseases. METHODS: Case control study of 297 patients from 8 Spanish centers including 100 healthy individuals, 101 diagnosed with AA, and 96 CRC cases. Quantitative real-time reverse transcription was used to quantify a signature of miRNA (miRNA19a, miRNA19b, miRNA15b, miRNA29a, miRNA335, and miRNA18a) in plasma samples. Binary classifiers (Support Vector Machine [SVM] linear, SVM radial, and SVM polynomial) were built for the best predictive model. RESULTS: Area under receiving operating characteristic curve of 0.92 (95% confidence interval 0.871-0.962) was obtained retrieving a model with a sensitivity of 0.85 and specificity of 0.90, positive predictive value of 0.94, and negative predictive value of 0.76 when advanced neoplasms (CRC and AA) were compared with healthy individuals. CONCLUSIONS: We identified and validated a signature of 6 miRNAs (miRNA19a, miRNA19b, miRNA15b, miRNA29a, miRNA335, and miRNA18a) as predictors that can differentiate significantly patients with CRC and AA from those who are healthy. However, large-scale validation studies in asymptomatic screening participants should be conducted

    Cardiogenic shock following administration of propofol and fentanyl in a healthy woman: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Cardiogenic shock is very uncommon in healthy people. The differential diagnosis for patients with acute heart failure in previously healthy hearts includes acute myocardial infarction and myocarditis. However, many drugs can also depress myocardial function. Propofol and fentanyl are frequently used during different medical procedures. The cardiovascular depressive effect of both drugs has been well established, but the development of cardiogenic shock is very rare when these agents are used.</p> <p>Case presentation</p> <p>After a minor surgical intervention, a 32-year-old Caucasian woman with no significant medical history went into sudden hemodynamic deterioration due to acute heart failure. An urgent echocardiogram showed severe biventricular dysfunction and an estimated left ventricular ejection fraction of 20%. Extracorporeal life support and mechanical ventilation were required. Five days later her ventricular function had fully recovered, which allowed the progressive withdrawal of medical treatment. Prior to her hospital discharge, cardiac MRI showed neither edema nor pathological deposits on the delayed contrast enhancement sequences. At her six-month follow-up examination, the patient was asymptomatic and did not require treatment.</p> <p>Conclusion</p> <p>Although there are many causes of cardiogenic shock, the presence of abrupt hemodynamic deterioration and the absence of a clear cause could be related to the use of propofol and fentanyl.</p

    Ownership and control in a competitive industry

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    We study a differentiated product market in which an investor initially owns a controlling stake in one of two competing firms and may acquire a non-controlling or a controlling stake in a competitor, either directly using her own assets, or indirectly via the controlled firm. While industry profits are maximized within a symmetric two product monopoly, the investor attains this only in exceptional cases. Instead, she sometimes acquires a noncontrolling stake. Or she invests asymmetrically rather than pursuing a full takeover if she acquires a controlling one. Generally, she invests indirectly if she only wants to affect the product market outcome, and directly if acquiring shares is profitable per se. --differentiated products,separation of ownership and control,private benefits of control

    Development of a Novel Anti-CD19 Chimeric Antigen Receptor : A Paradigm for an Affordable CAR T Cell Production at Academic Institutions

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    Genetically modifying autologous T cells to express an anti-CD19 chimeric antigen receptor (CAR) has shown impressive response rates for the treatment of CD19+ B cell malignancies in several clinical trials (CTs). Making this treatment available to our patients prompted us to develop a novel CART19 based on our own anti-CD19 antibody (A3B1), followed by CD8 hinge and transmembrane region, 4-1BB- and CD3z-signaling domains. We show that A3B1 CAR T cells are highly cytotoxic and specific against CD19+ cells in vitro, inducing secretion of pro-inflammatory cytokines and CAR T cell proliferation. In vivo, A3B1 CAR T cells are able to fully control disease progression in an NOD.Cg-Prkdc Il2rd/SzJ (NSG) xenograph B-ALL mouse model. Based on the pre-clinical data, we conclude that our CART19 is clearly functional against CD19+ cells, to a level similar to other CAR19s currently being used in the clinic. Concurrently, we describe the implementation of our CAR T cell production system, using lentiviral vector and CliniMACS Prodigy, within a medium-sized academic institution. The results of the validation phase show our system is robust and reproducible, while maintaining a low cost that is affordable for academic institutions. Our model can serve as a paradigm for similar institutions, and it may help to make CAR T cell treatment available to all patients

    Point-Of-Care CAR T-Cell Production (ARI-0001) Using a Closed Semi-automatic Bioreactor: Experience From an Academic Phase I Clinical Trial

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    Development of semi-automated devices that can reduce the hands-on time and standardize the production of clinical-grade CAR T-cells, such as CliniMACS Prodigy from Miltenyi, is key to facilitate the development of CAR T-cell therapies, especially in academic institutions. However, the feasibility of manufacturing CAR T-cell products from heavily pre-treated patients with this system has not been demonstrated yet. Here we report and characterize the production of 28 CAR T-cell products in the context of a phase I clinical trial for CD19+ B-cell malignancies (NCT03144583). The system includes CD4-CD8 cell selection, lentiviral transduction and T-cell expansion using IL-7/IL-15. Twenty-seven out of 28 CAR T-cell products manufactured met the full list of specifications and were considered valid products. Ex vivo cell expansion lasted an average of 8.5 days and had a mean transduction rate of 30.6 ± 13.44%. All products obtained presented cytotoxic activity against CD19+ cells and were proficient in the secretion of pro-inflammatory cytokines. Expansion kinetics was slower in patient's cells compared to healthy donor's cells. However, product potency was comparable. CAR T-cell subset phenotype was highly variable among patients and largely determined by the initial product. TCM and TEM were the predominant T-cell phenotypes obtained. 38.7% of CAR T-cells obtained presented a TN or TCM phenotype, in average, which are the subsets capable of establishing a long-lasting T-cell memory in patients. An in-depth analysis to identify individual factors contributing to the optimal T-cell phenotype revealed that ex vivo cell expansion leads to reduced numbers of TN, TSCM, and TEFF cells, while TCM cells increase, both due to cell expansion and CAR-expression. Overall, our results show for the first time that clinical-grade production of CAR T-cells for heavily pre-treated patients using CliniMACS Prodigy system is feasible, and that the obtained products meet the current quality standards of the field. Reduced ex vivo expansion may yield CAR T-cell products with increased persistence in vivo
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