Search

While modeling solute transport has been an active subject of research in the past few decades, the influence of pore‐wall roughness on contaminant migration has not yet been addressed. We therefore conduct particle tracking simulations in three porous domains that have different pore‐wall roughness characteristics. Specifically, we consider five surface fractal dimensions ds = 1.0, 1.1, 1.2, 1.4, and 1.6, and four different Péclet numbers Pe = 10, 102, 103, and 105. Overall, arrival time distributions are simulated for 60 scenarios (3 domains × $\times $ 5 surface fractal dimensions × $\times $ 4 Péclet numbers) some of which show heavy‐tailed patterns indicating non‐Fickian transport. To interpret the simulations and quantify the transport behavior, we analyze the resulting arrival time distributions by the continuous time random walk (CTRW) approach. Results show that, on average, as the surface fractal dimension increases from 1.0 to 1.6, the CTRW model parameters β $\beta $, an exponent showing the degree of anomalous transport, v, the average solute velocity, and t2, the cut‐off time to Fickian transport, remain nearly constant. However, the dispersion coefficient, D, increases and the characteristic transition time, t1, decreases. We found t1 and D are more sensitive to pore‐wall roughness compared to the other CTRW parameters. We also found that as the Péclet number increases from 10 to 105, on average, v and D increase, t1 and β $\beta $ decrease, and t2 remains nearly constant. The simulations demonstrate that the exponent β $\beta $ and the dispersion coefficient are correlated to the average solute velocity. Key Points: Characteristic transition time and dispersion coefficient are sensitive to pore‐wall roughnessThe exponent β, showing the degree of anomalous transport, is correlated to average solute velocityAs Péclet number increases from 10 to 100,000, v and D increase, t1 and β decrease, and t2 remains nearly constant [ABSTRACT FROM AUTHOR]

Background. Acute appendicitis (AA) might be amenable to conservative antibiotic treatment, whereas a perforated appendix (PA) necessitates surgery. We investigated the value of clinical–laboratory markers in distinguishing AA from a PA. Methods. Retrospectively obtained preoperative parameters for 306 consecutive patients (<18 years) with histologically confirmed appendicitis (AA (n = 237) vs. PA (n = 69)), treated at our institution between January 2014 and December 2017. Results. A PA was associated with male preponderance, younger age, decreased sodium level and increased white blood cell count, Tzanakis score, C-reactive protein (CRP) level, and CRP-to-lymphocyte ratio (CLR). Upon discrimination analysis, CLR and CRP displayed the highest accuracy in differentiating a PA from AA. Regression analysis identified levels of CRP, sodium, and the Tzanakis score as independent predictors for a PA. Conclusion. Levels of CLR, CRP, sodium, and Tzanakis score might support decision-making regarding treatment options for pediatric appendicitis. [ABSTRACT FROM AUTHOR]

Silver nanoparticles have attracted great interests widely in medicine due to its great characteristics of antibacterial activity. In this research, the antibacterial activity and biocompatibility of a topical gel synthesized from polyvinyl alcohol, chitosan, and silver nanoparticles were studied. Hydrogels with different concentrations of silver nanoparticles (15 ppm, 30 ppm, and 60 ppm) were evaluated to compare their antibacterial activity, nanoparticles' sizes, and in vivo behaviors. The resulted silver nanoparticles in the hydrogel were characterized by TEM showing the nanoparticles' sizes less than 22 nm. The in vitro results prove that the antibacterial effects of all of the samples are satisfied. However, the in vivo results demonstrate the significant difference among different hydrogels in wound healing, where hydrogel with 30 ppm shows the best healing rate. [ABSTRACT FROM AUTHOR]