417 research outputs found

    The impact of age and comorbidity on the postoperative outcomes after emergency surgical management of complicated intra-abdominal infections

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    Age-adjusted Charlson Comorbidity Index (a-CCI) score has been used to weight comorbid conditions in predicting adverse outcomes. A retrospective cohort study on adult patients diagnosed with complicated intra-abdominal infections (cIAI) requiring emergency surgery was conducted in order to elucidate the role of age and comorbidity in this scenario. Two main outcomes were evaluated: 90-day severe postoperative complications (grade ≥ 3 of Dindo-Clavien Classification), and 90-day all-cause mortality. 358 patients were analyzed. a-CCI score for each patient was calculated and then divided in two comorbid categories whether they were ≤ or > to percentile 75 (= 4): Grade-A (0–4) and Grade-B (≥ 5). Univariate and multivariate regression analyses were performed, and the predictive validity of the models was evaluated by the area under the receiver operating characteristics (AUROC) curve. Independent predictors of 90-day severe postoperative complications were Charlson Grade-B (Odds Ratio [OR] = 3.49, 95% confidence interval [95%CI]: 1.86–6.52; p < 0.0001), healthcare-related infections (OR = 7.84, 95%CI: 3.99–15.39; p < 0.0001), diffuse peritonitis (OR = 2.64, 95%CI: 1.45–4.80; p < 0.01), and delay of surgery > 24 hours (OR = 2.28, 95%CI: 1.18–4.68; p < 0.02). The AUROC was 0.815 (95%CI: 0.758–0.872). Independent predictors of 90-day mortality were Charlson Grade-B (OR = 8.30, 95%CI: 3.58–19.21; p < 0.0001), healthcare-related infections (OR = 6.38, 95%CI: 2.72–14.95; p < 0.0001), sepsis status (OR = 3.98, 95%CI: 1.04–15.21; p < 0.04) and diffuse peritonitis (OR = 3.06, 95%CI: 1.29–7.27; p < 0.01). The AUROC for mortality was 0.887 (95%CI: 0.83–0.93). Post-hoc sensitivity analyses confirmed that the degree of comorbidity, estimated by using an age-adjusted score, has a critical impact on the postoperative course following emergency surgery for cIAI. Early assessment and management of patient’s comorbidity is mandatory at emergency setting

    ZnO growth by MOCVD: numerical study

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    EnIII−V compound device fabrication is facing today challenging issues typically related to high volume manufacturing such as process reliability, process consistency, cost−reduction. Each step of the overall device manufacturing process must be carefully analysed and replicated to obtain reproducible device structures. Purifiers are commonly used in MOVPE processes and are becoming standard equipment in both research and production environments. In most cases implementation of gas purification strategies is enabling to achieve ultimate product purity and process reproducibility by defect and contamination control. In addition, an appropriate gas purification strategy is effective in high value component/chemicals protection (e.g. high purity MO sources), and as an assurance against line contamination due to human error or component failure. Purifier operating conditions can vary noticeably and a knowledge of which parameters can affect ultimate gas purity should be of interest to MOVPE operators to master gas distribution line contamination issues. Expertise on such parameters and their effect is essential to obtain a reliable product and sub−ppb contamination control throughout the purifier's lifetime and not only in spot demonstrations

    Aplicaciones analíticas de la reducción fotoquímica de la riboflavina el ácido etilenodiaminotetraacético. Determinación de ioduro

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    A kinetic study of the photochemical reaction of riboflavin and EDTA (in the absence of oxygen) has been made in connection with development of a new kinetic method for iodide. The reaction is first-order with respect to riboflavin, EDTA and absorbed light-intensity. The rate of photoreduction is strongly pH^dependent, and maximal at about pH 7,5. The photoreduction involves a long-Uved excited state of the vitamin B2 and is dramaticalUy retarded by small amounts of iodide. A tenta'tive mechanism is proposed, and the experimental conditions have been optimized. The variable time method appears to be the most suitable for determination of iodide. A detection limit of 8 [xg/rnl and a casfficient of variation about 3 % can be adhieved. Chloride and bromide do not interfere at levéis below 100-fold mole ratio to iodide. Metal ions do not interfere if enough excess of EDTA is used.Se ha estudiado la reacción fotoquímica entre la riboflavina y el ácido etilenodiaminotetraacético (en ausencia de oxígeno) con la finalidad de desarrollar un método cinético para la determinación de ioduro. La reacción es de primer orden con respecto a la riboflavina, AEDT e intensidad de la radiación absorbida. La velocidad del proceso fotoquímico depende del pH y es máxima a pH 7,2. La fotorreducción tiene lugar a través de estados excitados de larga vida de la vitamina B2 y está muy afectada por la presencia de pequeñas cantidades de ioduro. Se propone un posible mecanismo y se han estudiado todas las variables con la finalidad de optimizar las condiciones del método analítico. Se ha empleado el procedimiento del tiempo variable como el más apropiado para la determinación de ioduro. La sensibilidad es de 8 fig/ml y el coeficien'te de variación del 3 %. Los iones bromuro y cloruro son compatibles hasta la relación 100/1. La interferencia de los iones metálicos se elimina añadiendo un exceso de AEDT

    Calibration of semi-analytic models of galaxy formation using Particle Swarm Optimization

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    We present a fast and accurate method to select an optimal set of parameters in semi-analytic models of galaxy formation and evolution (SAMs). Our approach compares the results of a model against a set of observables applying a stochastic technique called Particle Swarm Optimization (PSO), a self-learning algorithm for localizing regions of maximum likelihood in multidimensional spaces that outperforms traditional sampling methods in terms of computational cost. We apply the PSO technique to the SAG semi-analytic model combined with merger trees extracted from a standard Λ\LambdaCDM N-body simulation. The calibration is performed using a combination of observed galaxy properties as constraints, including the local stellar mass function and the black hole to bulge mass relation. We test the ability of the PSO algorithm to find the best set of free parameters of the model by comparing the results with those obtained using a MCMC exploration. Both methods find the same maximum likelihood region, however the PSO method requires one order of magnitude less evaluations. This new approach allows a fast estimation of the best-fitting parameter set in multidimensional spaces, providing a practical tool to test the consequences of including other astrophysical processes in SAMs.Comment: 11 pages, 4 figures, 1 table. Accepted for publication in ApJ. Comments are welcom

    Faceting and structural anisotropy of nanopatterned CdO(110) layers

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    CdO(110) layers with a self-organized surface structure have been grown on (10math0) sapphire (m plane) substrates by metal-organic vapor phase epitaxy. The epitaxial relationships between layer and substrate have been determined and a crystallographic model that accounts for the CdO in-plane orientation, which results in a reduced lattice mismatch when the CdO[001] direction is perpendicular to the sapphire c axis, has been proposed. Although the measured lattice parameters indicate that the layers are almost fully relaxed, an anisotropic mosaicity is detected with symmetrical rocking curves attaining minimum values when measured along the CdO[math10] direction. The layer morphology consists of a regular ridge-and-valley structure which defines, again, a preferential in-plane direction. The grooves run parallel to the CdO[001] axis and exhibit lateral surfaces sloped at 28° with respect to the (110) surface. The influence of growth temperature and VI∕II molar ratio on the anisotropic mosaicity and morphology has been [email protected] [email protected] [email protected]

    Estudio de lesiones óseas alvéolo-dentarias en población extinta de la provincia de Catamarca

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    Lesiones óseas alvéolo-dentarias son importantes para el estudio de la dieta, nutrición y su relación con la presión ambiental a la que se ven expuestas las poblaciones. En este trabajo se realizó un registro de las patologías halladas en distintas colecciones del Museo de La Plata (UNLP) procedente de la Provincia de Catamarca, poblaciones que estuvieron expuestas a importantes factores causantes de estrés nutricional y social. De la muestra integrada por 43 piezas, se seleccionaron 15 cranium y 10 calvarium que fueron registrados por edad, sexo, dentición, maxilar y grupo dentario.Facultad de Odontologí

    Spatial distribution and temporal dynamics of invasive and native mosquitoes in a large Mediterranean city

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    Mosquitoes, including invasive species like the Asian tiger mosquito Aedes albopictus, alongside native species Culex pipiens s.l., pose a significant nuisance to humans and serve as vectors for mosquito-borne diseases in urban areas. Under- standing the impact of water infrastructure characteristics, climatic conditions, and management strategies on mosquito oc- currence and effectiveness of control measures to assess their implications on mosquito occurrence is crucial for effective vector control. In this study, we examined data collected during the local vector control program in Barcelona, Spain, focusing on 234,225 visits to 31,334 different sewers, as well as 1817 visits to 152 fountains between 2015 and 2019. We investigated both the colonization and recolonization processes of mosquito larvae within these water infrastructures. Our findings re- vealed higher larval presence in sandbox-sewers compared to siphonic or direct sewers, and the presence of vegetation and the use of naturalized water positively influenced larval occurrence in fountains. The application of larvicidal treatment significantly reduced larvae presence; however, recolonization rates were negatively affected by the time elapsed since treat- ment. Climatic conditions played a critical role in the colonization and recolonization of sewers and urban fountains, with mosquito occurrence exhibiting non-linear patterns and, generally, increasing at intermediate temperatures and accumulated rainfall levels. This study emphasizes the importance of considering sewers and fountains characteristics and climatic condi- tions when implementing vector control programs to optimize resources and effectively reduce mosquito populations

    Examination of the Feynman-Hibbs Approach in the Study of NeN_N-Coronene Clusters at Low Temperatures

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    Feynman-Hibbs (FH) effective potentials constitute an appealing approach for investigations of many-body systems at thermal equilibrium since they allow us to easily include quantum corrections within standard classical simulations. In this work we apply the FH formulation to the study of NeN_N-coronene clusters (N=N= 1-4, 14) in the 2-14 K temperature range. Quadratic (FH2) and quartic (FH4) contributions to the effective potentials are built upon Ne-Ne and Ne-coronene analytical potentials. In particular, a new corrected expression for the FH4 effective potential is reported. FH2 and FH4 cluster energies and structures -obtained from energy optimization through a basin-hoping algorithm as well as classical Monte Carlo simulations- are reported and compared with reference path integral Monte Carlo calculations. For temperatures T>4T> 4 K, both FH2 and FH4 potentials are able to correct the purely classical calculations in a consistent way. However, the FH approach fails at lower temperatures, especially the quartic correction. It is thus crucial to assess the range of applicability of this formulation and, in particular, to apply the FH4 potentials with great caution. A simple model of NN isotropic harmonic oscillators allows us to propose a means of estimating the cut-off temperature for the validity of the method, which is found to increase with the number of atoms adsorbed on the coronene molecule

    Contribution of Efflux Pumps, Porins, and B-Lactamases to Multidrug Resistance in Clinical Isolates of Acinetobacter baumannii

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    Weinvestigated the mechanisms of resistance to carbapenems, aminoglycosides, glycylcyclines, tetracyclines, and quinolones in 90 multiresistant clinical strains of Acinetobacter baumannii isolated from two genetically unrelated A. baumannii clones: clone PFGEROC- 1 (53 strains producing the OXA-58B-lactamase enzyme and 18 strains with the OXA-24B-lactamase) and clone PFGE-HUI-1 (19 strains susceptible to carbapenems).Weused real-time reverse transcriptase PCR to correlate antimicrobial resistance (MICs) with expression of genes encoding chromosomalB-lactamases (AmpC and OXA-51), porins (OmpA, CarO, Omp33, Dcap-like, OprB, Omp25, OprC, OprD, and OmpW), and proteins integral to six efflux systems (AdeABC, AdeIJK, AdeFGH, CraA, AbeM, and AmvA). Overexpression of the AdeABC system (level of expression relative to that by A. baumannii ATCC 17978, 30- to 45-fold) was significantly associated with resistance to tigecycline, minocycline, and gentamicin and other biological functions. However, hyperexpression of the AdeIJK efflux pump (level of expression relative to that by A. baumannii ATCC 17978, 8- to 10-fold) was significantly associated only with resistance to tigecycline and minocycline (to which the TetB efflux system also contributed). TetB and TetA(39) efflux pumps were detected in clinical strains and were associated with resistance to tetracyclines and doxycycline. The absence of the AdeABC system and the lack of expression of other mechanisms suggest that tigecycline-resistant strains of the PFGE-HUI-1 clone may be associated with a novel resistance-nodulation-cell efflux pump (decreased MICs in the presence of the inhibitor Phe-ArgB-naphthylamide dihydrochloride) and the TetA(39) system
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