2,653 research outputs found
Study of the impact of the planned CMS detector upgrade on the Higgs to b-quarks measurements
The aim of this Thesis is to study the Higgs boson coupling to bottom quarks in the next Runs of the Large Hadron Collider (LHC). In particular the performance of a simplified analysis in the context of the CMS experiment is studied in different scenarios, starting from the upcoming LHC Run 2 and extending to long term runs, after upgrades of the LHC machine and of the CMS detector.
This Thesis work also includes contribution to the qualification of silicon pixel modules for the new CMS pixel tracker that will replace the current one at the end of 2016.
For a Higgs boson of 125 GeV, the decay to a bottom quark pair (bb) is the dominant mode, with a branching ratio of approximately 58%. However, the prevailing QCD multijet background events prevent an inclusive search of the Higgs boson in the bb decay channel.
Therefore searches of the H(bb) decay at the LHC consider particular production modes of the Higgs boson: the vector boson fusion and the associated production with a vector boson or with a top quark pair.
In this Thesis, the associated production of the Higgs with a Z boson has been studied, when the latter decays into a pair of opposite sign muons or electrons (referred to as leptons hereafter).
In such final state the signature of two isolated opposite sign leptons from the Z boson decay helps for triggering and rejecting background events. Due to the nearly hermetic coverage of the CMS detector and thanks to its silicon tracker, its high granularity electromagnetic calorimeter and its excellent muon system, leptons originating from Z bosons can be efficiently identified and precisely reconstructed.
The reconstruction of the Higgs boson in the bb final state relies on the identification of b-jets, originating from the hadronization of b-quarks into B hadrons.
Therefore, dedicated b-tagging algorithms have been developed to identify b-jets, being based on distinguishing features of the B hadrons.
The latter are characterized by relatively long lifetimes, such that they decay inside the tracker volume and tracks of daughter charged particles identify a secondary displaced vertex within the jet. Moreover, such tracks also tend to have larger impact parameters.
A good ability in b-jet identification relies on efficient and high quality tracking and vertexing, that can only be achieved with an appropriate performance of a pixel tracking detector.
Therefore, the second main topic of this Thesis deals with activities that contribute to upgrade the CMS silicon pixel tracker to ensure and improve its performance.
The current CMS silicon pixel tracker was designed to sustain a maximum fluence of 1.6*1015 neq/cm2 and to operate at a maximum instantaneous luminosity of 1034 cm-2s-1. As the latter limits will be exceeded at the end of the LHC Run 2 in 2016, the pixel tracker must be replaced with a new upgraded one by then. The so called Phase 1 upgrade pixel tracker is currently being built and is expected to be installed at the end of 2016. It will have one additional silicon layer with respect to the current one and the innermost layer closer to the interaction point, without increasing the amount of material.
Such improvements will result in a higher tracking efficiency, which is important for tracking performance and hence for b-jet identification.
Additional extended upgrades of the CMS tracker, usually referred to as Phase 2 upgrades, are foreseen around 2023 before the beginning of High Luminosity Phase of the LHC, needed to retain the same excellent detector performances in an even more challenging environment.
This Thesis is organized in seven Chapters.
Chapter 1 introduces the Higgs-Brout-Englert mechanism of spontaneous symmetry breaking in the Standard Model of Particle Physics and summarizes the phenomenology of Higgs boson production and decays at hadron colliders. Latest experimental searches for the Higgs boson at the LHC leading to its discovery in 2012 are also cited.
In Chapter 2 the layout and operation of the LHC machine are briefly summarized. Then the subsystems of the CMS detector are described, including the main upgrades planned for the coming years, highlighting the improvements in the inner and outer silicon tracking detector.
Chapter 3 focuses on the building and commissioning of the Phase 1 upgrade pixel tracker, that shall be installed at the end of 2016. After illustrating the components of pixel barrel modules, activities currently going on in the Pisa production center are described.
In Chapter 4 as an introduction to the analysis work the main strategies and algorithms for particle identification and reconstruction adopted by the CMS collaboration are presented.
The first Section of Chapter 5 summarizes the strategy and results for the search of the Higgs boson produced in association with a vector boson and decaying to a bb pair, performed on data collected with the CMS detector until the end of 2012. The second Section describes the preparation of the analysis for the LHC run at a center of mass energy of 13 TeV. First, some basic kinematics studies comparing Monte Carlo samples at 8 and 13 TeV are performed. Then, the performance of a simple cut-based invariant mass analysis is evaluated and the choice of different b-tagging discriminators and working points is evaluated.
In Chapter 6 the impact of the b-tagging performance on the Z(ll)H(bb) sensitivity is estimated in future detector upgrade scenarios. Due to the impossibility of producing large full simulation samples for the most important background processes in such future scenarios, the studies are based on a two-dimensional parametrization of the b-tagging efficiency, derived from fully simulated ttbar samples, available for all the considered scenarios.
Such parametrization is then used to estimate the sensitivity of the Z(ll)H(bb) analysis in those future upgrade scenarios, highlighting the improvements that are expected to be achieved thanks to better tracking capabilities.
In the last Chapter 7 the most relevant results of this Thesis are summarized
Presence of Destruxin A and Beauvericin in cereals
A LC-MS/MS method for the detection of destruxin A (DTX A) and beauvericin (BEA) in
cereals was developed, validated and applied to commercial products collected in Italian
markets in the years 2015-2016. Results showed that BEA contaminated 59 % of the
samples even if only 15 of them (34%) showed quantifiable residues (comprised between
0.11 and 7.51 ng/g). The sample of red rice contaminated with the highest BEA level was
also contaminated with DTX A (0.28 ng/g). Finally, no significant differences were
detected between contaminated samples based on the production year and the agronomic
technology used (organic or conventional farming)
Calyx and dimorphic neurons of mouse Scarpa's ganglion express histamine H3 receptors
<p>Abstract</p> <p>Background</p> <p>Histamine-related drugs are commonly used in the treatment of vertigo and related vestibular disorders. The site of action of these drugs however has not been elucidated yet. Recent works on amphibians showed that histamine H3 receptor antagonists, e.g. betahistine, inhibit the afferent discharge recorded from the vestibular nerve. To assess the expression of H3 histamine receptors in vestibular neurons, we performed mRNA RT-PCR and immunofluorescence experiments in mouse Scarpa's ganglia.</p> <p>Results</p> <p>RT-PCR analysis showed the presence of H3 receptor mRNA in mouse ganglia tissue. H3 protein expression was found in vestibular neurons characterized by large and roundish soma, which labeled for calretinin and calbindin.</p> <p>Conclusion</p> <p>The present results are consistent with calyx and dimorphic, but not bouton, afferent vestibular neurons expressing H3 receptors. This study provides a molecular substrate for the effects of histamine-related antivertigo drugs acting on (or binding to) H3 receptors, and suggest a potential target for the treatment of vestibular disorders of peripheral origin.</p
First in vivo MRI study on theranostic dendrimersomes
Amphiphilic Janus-dendrimers are able to self-assemble into nanosized vesicles named dendrimersomes.We recently
synthesized the 3,5-C12-EG-(OH)4 dendrimer that generates dendrimersomes with very promising safety
and stability profiles, that can be loaded with different contrast agents for in vivo imaging. In this contribution,
nanovesicles were loaded with both the Magnetic Resonance Imaging (MRI) reporter GdDOTAGA(C18)2 and
the glucocorticoid drug Prednisolone Phosphate (PLP), in order to test their effective potential as theranostic
nanocarriers on murine melanoma tumour models. The incorporation of GdDOTAGA(C18)2 into the membrane
resulted in dendrimersomes with a high longitudinal relaxivity (r1 = 39.1 mM−1 s−1, at 310 K and 40 MHz)
so that, after intravenous administration, T1-weighted MRI showed a consistent contrast enhancement in the tumour
area. Furthermore, the nanovesicles encapsulated PLP with good efficiency and displayed anti-tumour activity
both in vitro and in vivo, thus enabling their practical use for biomedical theranostic applications
Patient safety : Use of quality management to prevent medication errors in the hospital medication use cycle
Objetivos: Describir los errores de medicación en el circuito de uso de medicamentos en una sala general de internación de un Hospital Público de referencia, e identificar estrategias de intervención en relación a la detección y prevención de estos errores.
Método: Estudio descriptivo, transversal. Hospital público general, de 190 camas, en Rosario (Argentina). Recolección de datos en forma diaria y sistemática del circuito de uso de medicamentos en una sala de internación general durante mayo 2009. Una vez identificados y caracterizados los errores, un grupo interdisciplinar aplicó en forma secuencial herramientas de gestión de calidad para reconocer causas y proponer y ponderar soluciones. (Flujograma, diagrama de causa y efecto, tormenta de ideas, grupo nominal y matriz de decisión).
Resultados: En el perÃodo de estudio se obtiene información de 60 pacientes, con detección de 506 errores de medicación. Los indicadores de incidencia mostraron los siguientes valores:8,4 errores/paciente y 88,6 errores/100 pacientes-dÃa.
De las causas identificadas se definieron como relevantes: «la doble prescripción»
y «la falta de normativas claras». De las diferentes soluciones propuestas se planteó
como estrategia de intervención incluir en la Historia ClÃnica una planilla de
«prescripción/indicación/administración» con un dise˜no diferente, habilitando actualización diaria, con un duplicado para la dispensación en Farmacia. Se genera un procedimiento operativo estándar para normatizar esta nueva modalidad de trabajo.
Conclusiones: Este trabajo logra, a través de la gestión de la calidad, el compromiso del equipo de salud para generar cambios que buscan tanto la seguridad del paciente como mejorar la calidad de las prestaciones que brinda el hospital.Objectives: To describe the medication errors in the medication use cycle in a general public hospital, and to identify intervention strategies in relation to the detection and prevention of these errors.
Methods: Descriptive study with cross-sectional design. General public hospital of 190 beds,in Rosario (Argentina). Daily and systematic data collection of the circuit of use of medicines during May 2009. Once the errors were identified and classified, an interdisciplinary group sequentially applied different quality management tools to recognize and weigh causes, and propose solutions. (Flowchart, Cause Effect Diagram, Brainstorming, Nominal Group and Matrix Decision).
Results: Information on 60 patients was retrieved during the study period, with 506 medication errors detected. The impact indicators showed the following values: 8.4 errors/patient and 88.6 errors/100 patients-day.
From the causes identified, two were defined as relevant: ‘‘Double prescription’’ and ‘‘Lack
of clear policy’’. Of the various solutions proposed, an intervention strategy was defined to
include a differently designed form for ‘‘prescription/indication/administration’’ in the clinical history which could be updated daily, with a duplicate to Pharmacy for the distribution, as well as a Standard Operating Procedure to standardize this new way of working.
Conclusion: This work achieved, through quality management, the commitment of a team of health professionals to seek and make changes for patient safety, and to improve the quality of services provided by the hospital.Fil: Salamano, Mercedes. Universidad Nacional de Rosario. Facultad de Ciencias BioquÃmicas y Farmacéuticas. Area Farmacia Asistencial; Argentina.Fil: Palchik, Valeria. Universidad Nacional de Rosario. Facultad de Ciencias BioquÃmicas y Farmacéuticas. Area Farmacia Asistencial ; ArgentinaFil: Botta, Carina. Universidad Nacional de Rosario. Facultad de Ciencias BioquÃmicas y Farmacéuticas. Area Farmacia Asistencial; ArgentinaFil: Colautti, Marisel. Universidad Nacional de Rosario. Facultad de Ciencias BioquÃmicas y Farmacéuticas. Area Farmacia Asistencial; ArgentinaFil: Bianchi, Mariela. Universidad Nacional de Rosario. Facultad de Ciencias BioquÃmicas y Farmacéuticas. Area Farmacia Asistencial; Argentina.Fil: Traverso, MarÃa Luz. Universidad Nacional de Rosario. Facultad de Ciencias BioquÃmicas y Farmacéuticas. Area Farmacia Asistencial; Argentin
In-depth investigation of the safety of wooden shelves used for traditional cheese ripening
9openInternationalItalian coauthor/editorThe main goal of this research was to characterize the bacterial diversity of the wooden boards used for aging traditional Sicilian cheeses and to evaluate whether pathogenic bacteria are associated with these surfaces. Eighteen cheese dairy factories producing three traditional cheese typologies (PDO Pecorino Siciliano, PDO Piacentinu Ennese, and Caciocavallo Palermitano) were selected within the region of Sicily. The wooden shelf surfaces were sampled by a destructive method to detach wood splinters as well as by a nondestructive brushing to collect microbial cells. Scanning electron microscopy showed the presence of almost continuous bacterial formations on the majority of the shelves analyzed. Yeasts and fungal hyphae were also visualized, indicating the complexity of the plank communities. The amplicon library of the 16S rRNA gene V3-V4 region was paired-end sequenced using the Illumina MiSeq system, allowing the identification of 14 phyla, 32 classes, 52 orders, 93 families, and 137 genera. Staphylococcus equorum was identified from all wooden surfaces, with a maximum abundance of 64.75%. Among cheese-surface-ripening bacteria, Brevibacterium and Corynebacterium were detected in almost all samples. Several halophilic (Halomonas, Tetragenococcus halophilus, Chromohalobacter, Salimicrobium, Marinococcus, Salegentibacter, Haererehalobacter, Marinobacter, and Idiomarinaceae) and moderately halophilic (Salinicoccus, Psychrobacter, and Salinisphaera) bacteria were frequently identified. Lactic acid bacteria (LAB) were present at low percentages in the genera Leuconostoc, Lactococcus, Lactobacillus, Pediococcus, and Streptococcus. The levels of viable microorganisms on the wooden shelves ranged between 2.4 and 7.8 log CFU/cm2. In some cases, LAB were counted at very high levels (8.2 log CFU/cm2). Members of the Enterobacteriaceae family were detected in a viable state for only six samples. Coagulase-positive staphylococci, Salmonella spp., and Listeria monocytogenes were not detected. Seventy-five strains belonged to the genera Leuconostoc, Lactococcus, Pediococcus, Enterococcus, Lactobacillus, and Weissella.openSettanni, Luca; Busetta, Gabriele; Puccio, Valeria; Licitra, Giuseppe; Franciosi, Elena; Botta, Luigi; Di Gerlando, Rosalia; Todaro, Massimo; Gaglio, RaimondoSettanni, L.; Busetta, G.; Puccio, V.; Licitra, G.; Franciosi, E.; Botta, L.; Di Gerlando, R.; Todaro, M.; Gaglio, R
Development of a questionnaire to assess patient's satisfaction with the use of medicines by generic name in Argentina
El objetivo del trabajo consiste en construir un cuestionario capaz de determinar y comparar
el nivel de satisfacción de los pacientes de distintos subsectores del sistema de salud en la utilización de medicamentos
por nombre genérico en Argentina (UMNG). Se rescatan cuestionarios validados, se proponen
Ãtems/dimensiones, determinando validez de contenido-aspecto, factibilidad con pruebas piloto, Mann-
Whitney para validar, Mantel-Haenszel Chi-Square para probar hipótesis y Análisis Factorial con rotación
Varimax para establecer dimensiones. La aplicación se realiza en 800 pacientes de subsectores Obras
Sociales y Privado. Se obtiene un instrumento, inicialmente validado, con 15 preguntas que califican satisfacción,
incorporadas en 3 dimensiones: Relaciones Personales, Eficacia y Económica. La comparación de
los niveles de satisfacción entre subsectores muestra mayor diferencia en 5 Ãtems de la primer dimensión,
con énfasis en la información, comunicación, y comportamiento interpersonal y en 3 Ãtems de las dimensiones
restantes. La población con Obra Social está más satisfecha con la UMNG que aquella con cobertura
privada.The aim of this study is to develop a questionnaire for assessing and comparing
level of patient's satisfaction with the use of medicines by generic name in Argentina, in patients of different
healthcare subsystems. The process involves bibliographic research for validated questionnaires, selection of
items/dimensions, aspect and content validity, feasibility. Two pilot tests for feasibility, Mann Whitney for validation,
Mantel-Haenszel Chi-Square to probe the hypothesis and Factorial analysis with Varimax rotation to determine
dimensions. Application in 800 patients of two healthcare subsystems. The result is a questionnaire, initially
validated, with 15 items to assess satisfaction, grouped in 3 dimensions: Personal Relationships, Efficacy
and Economic. The comparison of level of satisfaction between subsystems shows more differences in 5 items of
the first dimension, with emphasis in information, communication and interpersonal behavior, and in 3 items of
the other dimensions. The questionnaire is able to show the difference between patients of subsystems. Patients
of the health insurance subsystem are more satisfied with the use of medicines by generic name than those from
the private subsystem.Colegio de Farmacéuticos de la Provincia de Buenos Aire
Lavado de manos en contexto de pandemia en personas de 60 a 78 años de Villa Dos Trece, Formosa, Argentina, año 2020
Introducción: la pandemia por el Covid-19 trajo consigo muchas consecuencias en cuanto a salud se refiere, y más aún si se piensa en las personas de elevada edad. Teniendo en cuenta esto, es necesario que las personas de la tercera edad sepan y entiendan las medidas de bioseguridad, más precisamente el lavado de manos, para evitar infectarse. Objetivo: conocer si las personas de entre 60 a 78 años de edad de la localidad de Villa Dos Trece, Formosa, Argentina han entendido el procedimiento para un correcto lavado de manos. MetodologÃa: se enfocó como un estudio cuantitativo de diseño descriptivo de corte transversal donde se seleccionó por muestreo no probabilÃstico y por juicio a un grupo de 30 personas de ambos sexos de entre 60 y 78 años de edad de la localidad de Villa Dos Trece, Formosa, Argentina
Cellulose recycling as a source of raw chirality
Modern organic chemistry requires easily obtainable chiral building blocks that show high chemical versatility for their application in the synthesis of enantiopure compounds. Biomass has been demonstrated to be a widely available raw material that represents the only abundant source of renewable organic carbon. Through the pyrolitic conversion of cellulose or cellulose-containing materials it is possible to produce levoglucosenone, a highly functionalized chiral structure. This compound has been innovatively used as a template for the synthesis of key intermediates of biologically active products and for the preparation of chiral auxiliaries, catalysts, and organocatalysts for their application in asymmetric synthesis.Fil: Biava, Hernan Daniel. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Rosario. Instituto de QuÃmica Rosario; ArgentinaFil: Spanevello, Rolando Angel. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Rosario. Instituto de QuÃmica Rosario; ArgentinaFil: Suarez, Alejandra Graciela. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Rosario. Instituto de QuÃmica Rosario; ArgentinaFil: Mata, Ernesto Gabino. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Rosario. Instituto de QuÃmica Rosario; ArgentinaFil: Mangione, Maria Ines. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Rosario. Instituto de QuÃmica Rosario; ArgentinaFil: Sarotti, Ariel Marcelo. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Rosario. Instituto de QuÃmica Rosario; ArgentinaFil: Corne, Valeria. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Rosario. Instituto de QuÃmica Rosario; ArgentinaFil: Botta, MarÃa Celeste. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Rosario. Instituto de QuÃmica Rosario; ArgentinaFil: Giordano, Enrique David Victor. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Rosario. Instituto de QuÃmica Rosario; ArgentinaFil: Giri, German Francisco. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Rosario. Instituto de QuÃmica Rosario; ArgentinaFil: Llompart, David Fernando. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Rosario. Instituto de QuÃmica Rosario; Argentin
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