INTRODUCCIÓN: la apendicitis aguda es una causa frecuente de dolor abdominal en el niño y es laurgencia quirúrgica abdominal más frecuente de la infancia pudiendo presentarse a cualquier edad, ...aunquees más frecuente entre los 6 y 10 años. La clínica del cuadro depende de múltiples factores, principalmentela edad y las horas de evolución de la patología. Constituye un desafío diagnóstico debido a la superposiciónde síntomas con otras patologías especialmente en los menores de 4 años. Es por ello que, ante la sospechaclínica, el médico debe solicitar exámenes complementarios de laboratorio y radiológicos que permitanrealizar el diagnóstico diferencial de manera de disminuir las laparotomías negativas y evitar lascomplicaciones. El retraso en su reconocimiento se asocia a un aumento de la morbilidad, mortalidad ycostos médicos. Tanto el examen de sangre como los estudios por imágenes ayudan al médico a tomar unadecisión frente a una patología común en la pediatría, el abdomen agudo.OBJETIVO: establecer si existe una relación entre la medición ecográfica del apéndice cecal en un pacientepediátrico con cuadro de abdomen agudo y el diagnóstico post operatorio.MATERIALES Y METODOS: estudio observacional, retrospectivo, analítico en el que se analizaron lospacientes internados en la Clínica Universitaria Reina Fabiola, de edad pediátrica (0 – 16 años), internadosentre el año 2017 y 2019. El diagnóstico histológico de apendicitis aguda se lo comparó con la medicióndel diámetro del apéndice cecal medido por la ecografía abdominal pre quirúrgica. Análisis estadístico:Para determinar la correlación entre las mediciones ecográficas del apéndice cecal y el diagnóstico posoperatorio en apendicitis pos anatomía patológica se utilizó el test de Student, dependiendo de ladistribución de las variables. Para establecer los valores de corte de las medidas objetivas del apéndice porecografía para determinar los distintos estadios de la apendicitis aguda se utilizaron curvas ROC tomandocon estándar de oro a la anatomía patológica. Para la determinación de la sensibilidad, especificidad, valorespredictivos positivos y negativos se utilizaron tablas de 2 x 2.RESULTADOS: Se analizaron los datos de 159 pacientes. La media (desviación estándar) del diámetro delapéndice cecal por ecografía fue de 0,86 (± 0,23 cm). El área bajo la curva para la ecografía para apendicitisen general, así como para apendicitis catarral y flegmonosa fueron bajas (0,198; 0,256 y 0,226respectivamente), de modo tal que no se estimaron la sensibilidad, especificidad, ni valores predictivos. Elárea bajo la curva de la ecografía para el diagnóstico de apendicitis gangrenosa y perforada mostraron unárea bajo la curva adecuada (0,861 y 0,869 respectivamente). Tomando como valores de corte de espesor del apéndice cecal por ultrasonografía de 1 cm para apendicitis gangrenosa y de 1,2 cm para apendicitisperforada se obtuvieron valores de sensibilidad de 45,3% y 40% y de especificidad de 97% y 92,2%,respectivamente.CONCLUSIONES: la ecografía es una importante herramienta para complementar los hallazgos clínicosal momento de evaluar un paciente pediátrico con abdomen agudo. Diámetros ecográficos de un apéndicemayor a 1 cm muestran una alta especificidad para el diagnóstico de una apendicitis evolucionada, es decir,apendicitis gangrenosa o apendicitis perforada. Estos hallazgos podrían conducir a tomas de decisionessobre una conducta quirúrgica con mayor celeridad.
INTRODUCCIÓN: La apendicitis es la urgencia quirúrgica más frecuente en pediatría. Las formascomplicadas están relacionadas con un retraso en la atención médica y/o en el diagnóstico. A lo largo dela ...pandemia COVID-19 se observó una disminución de consultas en los hospitales por temor a contagiarsey romper con el aislamiento. Esto generó un diagnóstico tardío con complicaciones en ciertas patologíastales como la apendicitis.OBJETIVO: Comparar la frecuencia de apendicitis complicada durante la pandemia de COVID-19 (grupopandemia) con un periodo anterior a la misma (grupo prepandemia) para determinar si hubo un aumento deestas. Analizar los datos demográficos, clasificación intraoperatoria de apendicitis, valores de laboratorio,tiempo de hospitalización, complicaciones postquirúrgicas.MATERIAL Y MÉTODO: Estudio observacional, retrospectivo, analítico, realizado en la ClínicaUniversitaria Reina Fabiola, durante el mes de junio del año 2022. Se incluyó a todo paciente internadomenor de 16 años con diagnóstico de apendicitis. Se realizó análisis descriptivo de las variables. Se utilizóla prueba de chi cuadrado para los datos cualitativos y test de T de Student o test de Mann Whitney paralos datos cuantitativos.RESULTADOS: Se estudiaron 89 pacientes, 42 correspondieron al momento de la pandemia y 47 al grupoprepandemia. En ambos grupos predominó el sexo masculino (55%). La edad media y desvío estándar (DE)de pacientes prepandemia fue de 10 (± 3) vs 9 (± 3) años durante la pandemia (p=0.04). No se observarondiferencias pre y durante la pandemia en el tiempo de evolución hasta la realización de la cirugía con unamedia (DE) de 36 (±20) vs 32 (±18) hs (p=0.85), en los días de internación 3 (±3.8) vs 4,5 (±3.8) días(p=0.84), en la frecuencia de apendicitis complicadas %38 vs %45 (p=0.88) ni en la frecuencia decomplicaciones postquirúrgicas %17 vs %24 (p=0.46). No se observaron diferencias pre y durante lapandemia en los valores de PCR con una media (DE) de 26.5(±51) vs 23(±48) mg/dl (p=0.38), leucocitos13350(±5000) miles/ul vs 14800(±5500) miles/ul (p=0.26) y porcentaje de polimorfonucleares neutrófilos%77.5(±11) vs %81(±11) (p=0.27).CONCLUSIONES: Durante la pandemia no se demostró un aumento significativo de la frecuencia depacientes con apendicitis complicada, ni en los días de internación, horas de evolución hasta laapendicetomía o complicaciones postquirúrgicas, en relación con los valores de laboratorio tampoco hubodiferencias entre PCR, recuento de glóbulos blancos y porcentaje de neutrófilos.
Li
x
La
y
Sr
z
MnO
3
thin films of various compositions (
x
,
y
,
z
) have been grown using pulsed laser deposition. The compositions of the films have been studied as a function of deposition ...temperature, target-to-substrate distance and deposition pressure with respect to different cation ratios of the targets by inductively coupled plasma mass spectrometry. When growing multi-elemental oxide thin films containing lithium (with its large mass difference to other elements), lithium loss is most probably inevitable. But the desired thin film composition can be achieved by selecting specific growth conditions and different target compositions. The experiments also elucidate some of the mechanisms behind the incongruent lithium transfer from the targets to thin films.
Heart rate, measured as beat-to-beat intervals, is not constant and varies in time. This property is known as heart rate variability (HRV) and it has been investigated in several diseases, including ...myocardial infarction (MI). The main hypothesis is that HRV embed some physiological processes that are characteristics of regulatory systems acting on cardiovascular system. It is possible to quantify such a complex behaviour starting from RR intervals properties itself with the idea that any event affecting the cardiac regulatory system significantly will disrupt and change HRV. In this article, we first review different methodologies previously published to calculate HRV indexes. We then searched literature for studies published on HRV and MI and we derive a metanalysis where published data allow calculation of composite outcomes.
Articles considered eligible for metanalysis were original retrospective/prospective studies investigating HRV after myocardial infarction, reporting follow up for mortality or significant cardiac complications. Random effect model was used to assessed for homogeneity and calculate composite outcome and its 95% confidence interval (CI).
21 studies were identified as eligible for subsequent analysis. Among these studies 5 large trials were eligible for metanalysis: "they included 3489 total post-MI patient with an overall mortality of 125/577 (21.7%) in patients with standard deviation of RR intervals (SDNN) less than 70 msec compared to 235/2912 (8.1%) in patients with SDNN > 70 msec". Metanalysis demonstrates that, after a MI, patients with SDNN below 70 msec on 24 hours ECG recording have almost 4 times more chance to die in the next 3 years.
Results from metanalysis and other studies considered (but not included in the analysis) are consistent with the final finding, that a disrupted HRV dynamic (low SDNN) is associated with higher adverse outcome. In this perspective, although data are strongly positive for a direct relationship between SDNN and mortality after MI, SDNN value must be considered carefully on a single patient. The primary purpose of the metanalysis was to address whether studies conducted on HRV and MI were consistent rather than established a cut-off for SDNN. HRV is simple, non invasive and relatively not expensive to obtain.
•In the interface a gradual reduction Ce4+→Ce3+ is revealed. The Ce reduction is confined to 6–8 (1 1 1) atomic planes.•Chemical intermixing occurs at the interface forming a ceria/zirconia solid ...solution also 6–8 atomic planes wide.•Systematic scan deflections are observed in STEM EELS linescans which are explicable by assuming a space charge at the interface (positive on the YSZ side, negative on the Ce oxide).•While the in-plane lattice mismatch of 5.3% is accommodated by misfit dislocations, out-of-plane a quasi-continuous transition from YSZ to CeO2 is facilitated within the intermixing zone in accordance with Vegard´s Law for a quasi-ternary system (CeO2–Ce2O3–YSZ). An excess lattice expansion measured in one single (1 1 1) plane at the interface is explicable by considering oxygen vacancy diffusion from Ce oxide to YSZ, thus providing an explanation for the space charge.
Epitaxial undoped and Gd2O3-doped ceria films were grown by pulsed laser deposition on (1 1 1) faced Y2O3-stabilized zirconia (YSZ). Highly localized cerium reduction at the film-substrate interfaces is revealed by atomically resolved valence EELS mapping using Cs aberration-corrected scanning transmission electron microscopy. The chemical profiles reveal interdiffusion of Ce, (Gd), Y, Zr, forming an intermixing zone at the interface 7–9 (1 1 1) lattice planes wide. In its vicinity, the fraction of Ce3+ raises gradually over 6–8 lattice planes from zero in the bulk ceria to ≈100% in one single plane at the interface. Beyond this plane the Ce3+ fraction drops sharply within the YSZ substrate. In the vicinity of the interface systematic scan deflections are observed during EELS line scans. The advancing electron probe experiences a retarding force at the ceria side, and an accelerating force at the YSZ side, irrespective of the scan direction. This behavior is suggestive of coulombic interactions between the electron probe and a charged interface. This is interpreted as an indication of the presence of a space-charge situation at the YSZ/ceria interface, resulting from an excess negative charge at the ceria side (due to Ce3+cations) and an excess positive charge at the YSZ side (due to oxygen vacancies).
SARS Cov 2 pandemic outbreak caused countless changes in the daily habits among people in the entire World. National Health Systems were highly stressed and at severe risk of collapse. In the first ...months of 2020, it was expected a worsening of the typical overcrowding working flow. Quite the opposite, we found out an unexpected decrease throughout the daily ED visits. We evaluated the ER visits of a University Metropolitan Hospital in Rome in March 2020, comparing them with the same month in 2019. We highlight the sharp decline in ED visits for deferrable urgencies, considered among the leading causes of ED overcrowding. On the contrary, the rate of visits for "time-dependent" pathologies is superimposable for those pathologies mainly centralized through the Out-of-Hospital Emergency System. In a historical period where significant outpatient activity restrictions took place, we expected an increase in ED visits for deferred emergencies. On the contrary, it was undergoing a considerable decrease. The critical decrease in accesses recorded in March 2020 can be considered an indicator of ED's improper use. Probably, the fear of a possible coronavirus-related infection might have to lead the population to refer to the ED just in case of real emergency condition or severe medical issues, as it should "normally" be. The critical decrease in accesses recorded in March 2020 can be considered an indicator of ED's improper use. We would highlight the need to sensitize people to proper use of Emergency Medical Services, avoiding overcrowding and overuse. This unexpected event, lead by a global pandemic, could help reorganize the whole Health System.
•Approach to a Fractional-Order-Derivatives (FOD) physical interpretation.•Modification in the equilibrium point preference because of the FOD.•Calculation of the attractor area in the xy ...phase.•Quantification of changes in the statistical properties of the system.•A FOD changes the system vector field as a system control parameter?
In this paper, a physical interpretation of the fractional-order-derivatives effects in a jerk system, based on Unstable Dissipative Systems (UDS), and a Saturated Non-Linear Function (SNLF), is presented. The system is electronically implemented in Multisim development platform for a 9-scrolls attractor generation. The behavior is analyzed trough the Detrended Fluctuation Analysis (DFA), Probability Density Function (PDF), bifurcation diagrams, and the implementation of a geometrical analysis of the phase space. The changes that the system undergoes when a fractional-order are analyzed. The results show that when the fractional integration-orders are considered, the areas of the generated attractor are modified with respect to the integer-order dynamic. The long-range correlations in the system are also modified because of the fractional-orders. Besides, a particular phenomenon in the equilibrium points preference occurs, which is induced when the fractional integration-order is applied in only one of the state variables.
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