White blood cell count and C-reactive protein together remain useful for diagnosis and staging of acute appendicitis in children

Background. Acute appendicitis (AA) is the most common acute surgical condition of the abdomen, and the most commonly misdiagnosed.Objective. To analyse the white blood cell count (WBCC) and C-reactive protein (CRP) contribution to the diagnosis of AA in children.Methods. This was a retrospective study of 943 consecutive patients operated on with the preoperative diagnosis of AA, in whom preoperative WBCC and CRP had both been measured. Postoperatively, the patients were divided into three groups: normal appendix (no AA), simple AA and complicated AA.Results. Of the 943 patients, 616 (65.3%) had simple AA. The mean (standard deviation (SD)) age for this group was 9.8 (3.2) years (p<0.01 v. complicated AA), the mean WBCC was 16.5 (5.0) × 109/L (p<0.01 v. complicated AA and no AA), and the mean CRP level was 304.8 (409.5) nmol/L (p<0.01 v. complicated AA). The mean age of the patients with complicated AA (283/943, 30.0%) was 7.9 (3.7) years, the mean WBCC was 17.7 (6.2) × 109/L (p<0.01 v. no AA) and the mean CRP level was 1 076.2 (923.8) nmol/L (p<0.01 v. no AA). The mean age of the patients with no AA (44/943, 4.7%) was 8.8 (3.2) years, the mean WBCC was 13.1 (5.3) × 109/L and the mean CRP was 361.9 (447.6) nmol/L. The WBCC was normal in 113/899 patients with appendicitis (12.6%) and CRP in 139 (15.5%). Both the WBCC and CRP were normal in 17 patients with appendicitis (1.9%). The best receiver operating characteristic (ROC) curve was obtained for WBCC when comparing all AA with no AA: cut-off point 15.0 × 109/L, sensitivity 65%, specificity 68%, area under the curve 0.70. The best ROC curve for CRP was obtained when comparing simple AA with complicated AA: cut-off point 361.9 nmol/L, sensitivity 74%, specificity 74%, area under the curve 0.81.Conclusions. The WBCC is helpful in diagnosing simple AA and CRP in diagnosing complicated AA. If both are normal, AA is very unlikely. Together the WBCC and CRP are useful tools in diagnosing and staging AA

Results from EDGES High-Band: II. Constraints on Parameters of Early Galaxies

We use the sky-average spectrum measured by EDGES High-Band ($90-190$ MHz) to constrain parameters of early galaxies independent of the absorption feature at $78$~MHz reported by Bowman et al. (2018). These parameters represent traditional models of cosmic dawn and the epoch of reionization produced with the 21cmFAST simulation code (Mesinger & Furlanetto 2007, Mesinger et al. 2011). The parameters considered are: (1) the UV ionizing efficiency ($\zeta$), (2) minimum halo virial temperature hosting efficient star-forming galaxies ($T^{\rm min}_{\rm vir}$), (3) integrated soft-band X-ray luminosity ($L_{\rm X\,<\,2\,keV}/{\rm SFR}$), and (4) minimum X-ray energy escaping the first galaxies ($E_{0}$), corresponding to a typical H${\rm \scriptstyle I}$ column density for attenuation through the interstellar medium. The High-Band spectrum disfavors high values of $T^{\rm min}_{\rm vir}$ and $\zeta$, which correspond to signals with late absorption troughs and sharp reionization transitions. It also disfavors intermediate values of $L_{\rm X\,<\,2\,keV}/{\rm SFR}$, which produce relatively deep and narrow troughs within the band. Specifically, we rule out $39.4<\log_{10}\left(L_{\rm X\,<\,2\,keV}/{\rm SFR}\right)<39.8$ ($95\%$ C.L.). We then combine the EDGES High-Band data with constraints on the electron scattering optical depth from Planck and the hydrogen neutral fraction from high-$z$ quasars. This produces a lower degeneracy between $\zeta$ and $T^{\rm min}_{\rm vir}$ than that reported in Greig & Mesinger (2017a) using the Planck and quasar constraints alone. Our main result in this combined analysis is the estimate $4.5$~$\leq \log_{10}\left(T^{\rm min}_{\rm vir}/\rm K\right)\leq$~$5.7$ ($95\%$ C.L.). We leave for future work the evaluation of $21$~cm models using simultaneously data from EDGES Low- and High-Band.Comment: Accepted in Ap

Emulsion Electrospinning for Drug Delivery: Two Encapsulation Methods

One major technique to fabricate core-shell fibers is emulsion electrospinning due to its simple setup and potential to preserve the bioactivity of a loaded agent within the core. Here, we explore two different emulsion electrospinning approaches to encapsulate a hydrophilic drug, as Lidocaine Hydrochloride (LidHCl), inside a hydrophobic polymer fiber, as Poly-Lactic Acid (PLA) in a core-shell structure. Therefore, we incorporate the drug in the fiber core by means of an aqueous phase containing or lacking a polymeric matrix Polyvinyl Alcohol (PVA) to disperse the drug. We studied the electrospinnability of PLA-based emulsion solutions to produce LidHCl-loaded smooth fibers by varying the applied voltage and the tip-to-collector distance. We evaluated the morphology and chemical properties of emulsion electrospun fibers by field emission scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. Finally, we analyzed the drug release profile of both core-shell structures and compared them with blend PLA-LidHCl fiber system. Analysis revealed that emulsion electrospun nanofibers were able to encapsulate the drug within the fibers in both cases. However, PVA matrix inside the core played a key role on the encapsulation and spatial distribution of the drug and therefore on its release. Results suggest that the in vitro release profile of a hydrophilic drug could be tailored by the presence of the inner matrix polymer enabling the production of electrospun fibers with desired features.Fil: Sanchez, Maria Alejandra. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Bioingeniería. Laboratorio de Medios e Interfases; Argentina. University of Loughborough; Reino Unido. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Rodriguez, Andrea Paola. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Bioingeniería. Laboratorio de Medios e Interfases; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Monsalve, Leandro Nicolas. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Industrial; ArgentinaFil: Georgiadou S. University of Loughborough; Reino Unid

Direct optimisation based model selection and parameter estimation using time-domain data for identifying localised nonlinearities

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordA major difficulty when modelling nonlinear structures from experimental vibration data is to determine the type of nonlinear functions that will better predict its dynamic response. In this paper we address this issue by developing a recursive framework in which the characteristics and parameters of nonlinear structures are identified using measured input and output time-domain data. Forward-backward and exhaustive search regression algorithms are exploited based on optimisation techniques to recursively select and quantify the best nonlinear functions from a predefined library of nonlinear terms. The framework assumes localised nonlinearities for which their location is assumed to be known. The proposed methodology is demonstrated using numerical and experimental examples of single and multi-degree-of-freedom systems. The results presented highlight key advantages of the proposed method including: the capability of treating multi-degree of freedom nonlinear systems holding different types of localised nonlinearities, and the capability of selecting nonlinear terms with a light computational effort and with limited number of time samples.University of Exete

Performance of cuprous oxide mesoparticles with different morphologies as catalysts in a carbon nanotube ink for printing electrochemical sensors

A simplified, surfactant-free method is presented for the synthesis of cuprous oxide mesoparticles involving the use of only three reactants at room temperature. Different morphologies, such as cubes, cuboctahedra, truncated octahedra, octahedra, hexapods, and porous spheres could be obtained using different concentrations of reactants. The roles played by each reactant in the synthesis are critically discussed. The mesoparticles were used in the formulation of carbon nanotube-based waterborne inks to prepare coated electrodes. The electrocatalytic activity of the different cuprous oxide mesoparticles used in the inks towards hydrogen peroxide reduction was measured and compared. Cuprous oxide hexapods yielded the highest sensitivity whereas porous spheres were superior in terms of stability. The combination of carbon nanotubes and cuprous oxide mesoparticles in waterborne ink allows printing of electrodes combining electrical conduction and electrocatalysis in a single layer printed onto flexible substrates.Fil: Veiga, Lionel S.. Instituto Nacional de Tecnología Industrial; ArgentinaFil: Garate, Octavio. Instituto Nacional de Tecnología Industrial; ArgentinaFil: Tancredi, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Industrial; ArgentinaFil: Monsalve, Leandro Nicolas. Instituto Nacional de Tecnología Industrial; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ybarra, Gabriel. Instituto Nacional de Tecnología Industrial; Argentin

Data-driven structural identification of nonlinear assemblies: Structures with bolted joints

This is the final version. Available on open access from Elsevier via the DOI in this recordData availability: Data will be made available on request.The identification of nonlinearities that have a significant impact on dynamic behaviour of complex mechanical structures is necessary for ensuring structural efficiency and safety. A new methodology for structural identification of nonlinear assemblies is proposed in this paper that enables the discovery of stiffness and damping nonlinear models especially when it is not possible to directly measure the degrees of freedom where non-trivial nonlinearities are located. Input-output time-domain data collected at accessible locations on the structure are used to learn nonlinear models in the unmeasured locations. This is accomplished by making use of virtual sensing and model reduction schemes along with a physics-informed identification method recently developed by the authors (Safari and Londoño 2021). The methodology is suited for weakly nonlinear systems with localised nonlinearities for which their location is assumed to be known. It also takes into account dominant modal couplings within the identification process. The proposed methodology is demonstrated on a case study of a nonlinear structure with a frictional bolted joint, in numerical and experimental settings. It is shown that the model selection and parameter estimation for weakly nonlinear elements can be carried out successfully based on a reduced-order model which includes only a modal equation along with relevant modal contributions. Using the identified localised nonlinear models, both the reduced and full-order models can be updated to simulate the dynamical responses of the structure. Results suggests that the identified nonlinear model, albeit simple, generalises well in terms of being able to estimate the structural responses around modes which were not used during the identification process. The identified model is also interpretable in the sense that it is physically meaningful since the model is discovered from a predefined library featuring different nonlinear characteristics.University of Exeter, Faculty of Environment, Science and Econom

Eric Hobsbawm: la historia y América Latina

El mes de abril del año 2017, el Departamento de Ciencias Sociales y Políticas y el Departamento de Humanidades de la Universidad del Pacífico rindieron público homenaje al ilustre historiador Eric Hobsbawm. Se invitó a la Dra. Scarlett O’Phelan, quien fue una de las más distinguidas estudiantes peruanas asesoradas por Hobsbawm, al Dr. Felipe Portocarrero, al Dr. Martín Monsalve y al profesor Luis Torrejón, para que hicieran breves intervenciones sobre diversas dimensiones de la personalidad y del trabajo académico de uno de los más importantes historiadores marxistas de los siglos XX y XXI. Con esta publicación, que reúne las intervenciones escritas, se busca que un mayor número de lectores encuentre una fuente de inspiración intelectual y humana en la notable producción histórica de este ilustre historiador que ha sido leído por varias generaciones de estudiantes peruanos y latinoamericanos

Análisis predictivo de las perspectivas de uso de identificadores por radiofrecuencia (rfid) en el Ecuador

RFID (Identificación por Radiofrecuencia) es un sistema inalámbrico basado en la emisión de ondas de radio frecuencia para transmitir y capturar datos. La tecnología está basada en etiquetas formadas por un microchip y un circuito impreso en forma de antena que emiten una serie de dígitos llamados EPC (código electrónico de producto). Esté código puede ser rastreado a largas distancias hasta un repositorio de información, lo que permite que a más de identificar el producto se conozca más información sobre el mismo. Los RFIDs mejoran procesos en la cadena de distribución de muchas empresas. Actualmente grandes compañías están aplicando RFID en sus procesos permitiéndoles resultados favorables. El presente artículo muestra una breve descripción de la tecnología RFID, su estado actual y sus diferentes aplicaciones en diversas empresas a nivel mundial. Finalmente, plantearemos perspectivas del uso y aplicación de RFID en el mercado ecuatoriano, basándonos en estudios realizados con una muestra de empresas del sector de distribución tecnológica y proyectos que se estén planificando en nuestro país.RFID (Radio Frequency Identification) is a wireless system based on the emission of radio frequency waves to transmit and capture data. The technology is based on labels consist of a microchip and a printed circuit board in the form of antenna that emit a series of digits called EPC (Electronic Product Code). The code can be traced over long distances up to a repository of information, which allows more than identify the product, knowing more about them. The RFIDs improve processes in the distribution chain of many businesses. Currently, large companies are implementing RFID in their processes allowing favorable results. This paper presents a brief overview of RFID technology, its current state and its various applications in a variety of companies worldwide. Finally, raise prospects of the use and application of RFID in the Ecuadorian market, based on studies conducted with a sample of companies in the distribution sector technology and projects that are being planned in our country

Reduction of Gordon-Mollenauer phase noise by midlink spectral inversion

We show that spectral inversion can be employed for regeneration to reduce the effect of phase noise (Gordon-Mollenauer phase noise) in a nonreturn-to-zero differential phase-shift-keying based transmission system. Several locations of the spectral inverter in an eight-span transmission link have been investigated. We show that the best results are obtained when the spectral inverter is placed in the middle of the link. Compared to the transmission system without spectral inverter, an improvement of over four decades in bit-error-rate performance is achieved