The importance of liver function assessment before cardiac surgery: A narrative review

The demand for cardiac surgery procedures is increasing globally. Thanks to an improvement in survival driven by medical advances, patients with liver disease undergo cardiac surgery more often. Liver disease is associated with the development of heart failure, especially in patients with advanced cirrhosis. Cardiovascular risk factors can also contribute to the development of both cardiomyopathy and liver disease and heart failure itself can worsen liver function. Despite the risk that liver disease and cirrhosis represent for the perioperative management of patients who undergo cardiac surgery, liver function is often not included in common risk scores for preoperative evaluation. These patients have worse short and long-term survival when compared with other cardiac surgery populations. Preoperative evaluation of liver function, postoperative management and close postoperative follow-up are crucial for avoiding complications and improving results. In the present narrative review, we discuss the pathophysiological components related with postoperative complications and mortality in patients with liver disease who undergo cardiac surgery and provide recommendations for the perioperative management

Vitamin D deficiency among children and adolescents living in sunny South Texas

Background: Exposure to sunlight is essential to produce Vitamin D (ViD). Recent studies suggest obesity is associated with low ViD concentration. Living in South Texas with 220 sunny days a year should be enough to maintain adequate ViD levels. We aimed to analyze ViD levels and obesity in children and adolescents. Methods: We included 1239 pediatric (1.5 to 18.8 years old) participants (primary care clinic from Laredo) with registered CDC percentiles of BMI (pBMI) and serum concentrations of ViD (Atellica™). Data are described as median (p25, p75), Loess correlation between pBMI and ViD, ANCOVA to adjust by age, sex, and pBMI. We used the program Stata v16.1. The size of effects is expressed as Cohen-d and eta squared (eta2). Results: The median age was 12.5 (9.5, 15.1) years, pBMI was 94 (80, 98), 49% females (n=611). The pBMI showed small differences by sex (M 82.1±24 vs M 84.5±23, Cohen-d 0.14, p,0.001). The Loess showed an inverse relationship between pBMI with a rapid drop of ViD from p90. The ANCOVA coefficients were negative for sex (b=- 0.32 for females p=0.007, eta2=0.03) and pBMI (b=-0.001, p=0.025, eta2=0.15) on ViD concentration. Conclusion: We conclude obesity and female are related to low concentration VitD in sunny Laredo. Perhaps participants with more pBMI have less outdoor physical activity and increased sequester of ViD from adipose tissue. Future research should analyze the effect of these findings on adulthood morbidity

Influencia de algunas variables en el ensayo a compresión de probetas testigo en un hormigón autocompactante

La estimación de la resistencia a compresión a través de la evaluación de probetas testigo depende de numerosas variables, entre ellas, el diámetro de la probeta testigo, la dirección de extracción en relación con la dirección del hormigonado, el estado de humedad de la probeta testigo en el momento de ser ensayada, la esbeltez de la probeta testigo, la armadura embebida en la probeta testigo y la edad del hormigón investigado. El objetivo de este trabajo experimental ha sido evaluar, para un hormigón autocompactante, el efecto que presentan algunas de estas variables en el resultado de la resistencia a compresión de las probetas testigo. Estos efectos pueden ser muy diferentes de los que ocurren en el hormigón vibrado, debido a que no existe en este caso un procedimiento específico para la compactación de las probetas moldeadas. Igualmente se han analizado los posibles factores de corrección utilizados en la estimación de la resistencia a compresión de la probeta moldeada a través de la resistencia a compresión de la probeta testigo. Para ello se han fabricado 30 bloques de 50x50x100 cm en HAC cubriendo un amplio rango de resistencias (20 MPa - 80 MPa), de los cuales se extrajeron un total de 360 probetas testigo. Paralelamente a la ejecución de los bloques se han fabricado 90 probetas cilíndricas de 15 30 cm que posteriormente fueron ensayadas a compresión a la misma edad que las probetas testigo (28 días). Los resultados muestran que algunas de las variables incíden de forma muy diferente en estos hormigones que en los hormigones convencionales, en especial la dirección de extracción y el coeficiente de paso para considerar la resistencia en probeta moldeada

Augmented Reality Based on SLAM to Assess Spatial Short-Term Memory

Spatial short-term memory is defined as the limited ability of people to retain and remember the location of elements for short periods of time. In this paper, we present the first AR app based on SLAM (Simultaneous Localization and Mapping) to assess spatial short-term memory. A total of 55 participants were involved in a study for remembering the real place where four virtual objects were located in the real environment. The participants were divided into two groups: the ARGroup (the participants learned the location of the virtual objects in the real environment in an adaptation phase using AR) and the NoARGroup (the participants learned the location of the objects by looking at photographs). The results indicated that the performance outcomes in remembering objects and their location for the participants in the ARGroup were statistically significantly greater than those obtained by the participants in the NoARGroup. From this result and our observations, we can conclude that touring the augmented environment helped the participants to better remember the location of virtual objects added to the real scene compared to looking at photographs of the environment. Furthermore, statistically significant differences were not found in relation to gender or age. Finally, our app has several advantages: 1) Our app works in any environment and does not require adding real elements to the environment; 2) the evaluators can select any real environment and place the virtual elements where they want and even change them between sessions; and 3) our app could work similar to the way spatial memory does in everyday life

Efficient Exploration of Quantified Uncertainty in Granular Crystals

Granular crystals present unique nonlinear properties that support standing waves. These depend on precompression and impurities. Thus, they can be used for different applications such as impact and shock dissipation. There are different models which rely on reasonable approximations and assumptions. While experimental results show good agreement with theory, there are experimental errors that are not easily explained and are usually attributed to the approximations made and phenomena that are not accounted for. This might be the result of not quantifying the uncertainty, since variables like the grain size, position, mass and Young modulus, of each particle, are uncertain. Building a response surface is computationally expensive, because the underlying mapping to be learned is a high dimensional problem. This work presents a way of quantifying uncertainty in granular crystals in a computationally efficient way. To accomplish this, a low dimensional response surface is approximated through the method of active subspaces. Within this framework, special structure within the inputs is exploited to project it onto a lower dimensional manifold. The problem of subspace approximation is then treated as an optimization problem, with the use of the Bayesian Information Criterion (BIC). We treat the underlying function to be learned as a Gaussian Process and use Gaussian process regression to generate predictive distributions for test inputs. Distributions obtained through these methods, present a model for uncertainty propagation and could potentially be used to better understand the experimental errors for different models