Atmosphere-Mediated Superhydrophobicity of Rationally Designed Micro/Nanostructured Surfaces

Superhydrophobicity has received significant attention over the past three decades owing to its significant potential in self-cleaning, anti-icing and drag reduction surfaces, energy-harvesting devices, antibacterial coatings, and enhanced heat transfer applications. Superhydrophobicity can be obtained via the roughening of an intrinsically hydrophobic surface, the creation of a re-entrant geometry, or by the roughening of a hydrophilic surface followed by a conformal coating of a hydrophobic material. Intrinsically hydrophobic surfaces have poor thermophysical properties, such as thermal conductivity, and thus are not suitable for heat transfer applications. Re-entrant geometries, although versatile in applications where droplets are deposited, break down during spatially random nucleation and flood the surface. Chemical functionalization of rough metallic substrates, although promising, is not utilized because of the poor durability of conformal hydrophobic coatings. Here we develop a radically different approach to achieve stable superhydrophobicity. By utilizing laser processing and thermal oxidation of copper (Cu) to create a high surface energy hierarchical copper oxide (CuO), followed by repeatable and passive atmospheric adsorption of hydrophobic volatile organic compounds (VOCs), we show that stable superhydrophobicity with apparent advancing contact angles ≈160° and contact angle hysteresis as low as ≈20° can be achieved. We exploit the structure length scale and structure geometry-dependent VOC adsorption dynamics to rationally design CuO nanowires with enhanced superhydrophobicity. To gain an understanding of the VOC adsorption physics, we utilized X-ray photoelectron and ion mass spectroscopy to identify the chemical species deposited on our surfaces in two distinct locations: Urbana, IL, United States and Beijing, China. To test the stability of the atmosphere-mediated superhydrophobic surfaces during heterogeneous nucleation, we used high-speed optical microscopy to demonstrate the occurrence of dropwise condensation and stable coalescence-induced droplet jumping. Our work not only provides rational design guidelines for developing passively durable superhydrophobic surfaces with excellent flooding-resistance and self-healing capability but also sheds light on the key role played by the atmosphere in governing wetting

Quantitative composite testing model based on measurement uncertainty and its application for the detection of phthalate esters

To improve the quantitative detection efficiency of chemical analysis and reduce the detection cost, the sample pass rate was estimated and mathematical statistics were used to calculate the optimal group size (Kopt) of the composite testing to save on the maximum workload. A quantitative composite testing model was developed based on chemical analysis measurement uncertainty. Using this model, the maximum allowable number of composited samples (Kmax) is first calculated using parameters of regulated limits (L), limit of quantification (LOQ), and method measured uncertainty (Urel) to ensure that the sensitivity of the composite testing can meet the limit requirements. Finally, the appropriate composite group size (Ka) can be obtained by creating a balance between Kopt, Kmax, and the practical information used for that particular test. Furthermore, based on a constructed model, a practical quantitative composite testing method of 3–10 samples was established for the routine detection of toy phthalates (PAEs). The experimental results showed that the quantitative limits of 7 PAEs were 9.1–41.8 mg/kg, the relative expansion uncertainties were 16.6%–23.2%, and the recovery rates were 91.0%–112.3%, with a relative deviation of less than 10%. All these meet international PAEs standards. Compared with the traditional individual and qualitative composite testing, this model will not decrease the detection sensitivity, but can save up to 17.9%–80.4% of the workload when it is employed in toy PAEs testing with the pass rate of 80%–99%. This quantitative composite testing method will be implemented in the coming revision of ISO 8124-6 toy PAEs standards

Association of Sexual Orientation with Mental Health Disorders and Cardiovascular Disease

Little is known about the risk of cardiovascular disease (CVD) among sexual minorities. The mechanisms linking sexual minority orientation and CVD risk is rarely studied as well. Based on minority stress theory, this dissertation developed a general hypothesis that sexual minorities are exposed to higher levels of stress than heterosexuals, which may leads to increased risks of mental health disorders and CVD. Four cross-sectional studies were conducted in this dissertation, analyzing the NESARC data of nationally-representative non-institutionalized U.S. adults. Specific analytic approaches include multiple logistic regression modelling, mediation analysis, latent class analysis, stratified analysis, and quantitative intersectionality analysis. In the first study, we assessed CVD risk among lesbians, gay men, and bisexuals (LGB) compared with self-identified heterosexuals and whether mental health disorders mediate this association. In the second study, we evaluated the impact of sexual minority stress on the CVD risk among sexual minorities and whether intersection of other social identities and psychosocial factors interactively affect this relationship. In the third study, we assessed the risk of CVD and mental health disorders for persons with uncertain sexual identity and those who self-identified as heterosexual but had same-gender sex and /or attraction. In the fourth study, we assessed the geographic disparities in CVD risk for LGB persons and modified effect by social support.Ph.D., Epidemiology -- Drexel University, 201

Efficiently Mastering the Game of NoGo with Deep Reinforcement Learning Supported by Domain Knowledge

Computer games have been regarded as an important field of artificial intelligence (AI) for a long time. The AlphaZero structure has been successful in the game of Go, beating the top professional human players and becoming the baseline method in computer games. However, the AlphaZero training process requires tremendous computing resources, imposing additional difficulties for the AlphaZero-based AI. In this paper, we propose NoGoZero+ to improve the AlphaZero process and apply it to a game similar to Go, NoGo. NoGoZero+ employs several innovative features to improve training speed and performance, and most improvement strategies can be transferred to other nonspecific areas. This paper compares it with the original AlphaZero process, and results show that NoGoZero+ increases the training speed to about six times that of the original AlphaZero process. Moreover, in the experiment, our agent beat the original AlphaZero agent with a score of 81:19 after only being trained by 20,000 self-play games’ data (small in quantity compared with 120,000 self-play games’ data consumed by the original AlphaZero). The NoGo game program based on NoGoZero+ was the runner-up in the 2020 China Computer Game Championship (CCGC) with limited resources, defeating many AlphaZero-based programs. Our code, pretrained models, and self-play datasets are publicly available. The ultimate goal of this paper is to provide exploratory insights and mature auxiliary tools to enable AI researchers and computer-game communities to study, test, and improve these promising state-of-the-art methods at a much lower cost of computing resources

Differentiating Between Simple And Complex Pediatric Musculoskeletal Extremity Infections: Identifying Predictors Early In The Hospital Course

Complex musculoskeletal infections, defined as subfascial reaching infections involving muscle, and/or bone, occur more frequently in our age of increasing antibiotic resistance and bacterial virulence. These infections correlate with longer hospital stays, increased surgical need, and poorer outcomes compared to simple superficial soft tissue infections. Pediatric musculoskeletal infections often have an ambiguous presentation, however, complicating diagnosis and appropriate treatment. The goal of this study is to identify predictors of complicated infections to allow for quick differentiation between simple and complex pediatric extremity infections. By identifying these factors, aggressive treatment of the potentially more serious infections early in the hospital course may improve outcomes. Children with complex musculoskeletal infections present with higher laboratory values, heart rate, and pain scores compared to simple infections. It is our belief, these values may help stratify patients into “simple” or “complex” infection groups. Early identification of patients with parameters correlated with “complex” infections may prevent delays of treatment and potentially decrease length of stay and complications for those with these high-virulence infections

Breakfast consumption habits and cognitive ability in chinese youth: A six year follow‐up longitudinal cohort study

This study aimed to assess the relationship between breakfast composition and long‐term regular breakfast consumption and cognitive function. Participants included 835 children from the China Jintan Cohort Study for the cross‐sectional study and 511 children for the longitudinal study. Breakfast consumption was assessed at ages 6 and 12 through parental and self‐administered ques-tionnaires. Cognitive ability was measured as a composition of IQ at age 6 and 12 and academic achievement at age 12, which were assessed by the Chinese versions of the Wechsler Intelligence Scales and standardized school reports, respectively. Multivariable general linear and mixed models were used to evaluate the relationships between breakfast consumption, breakfast composition and cognitive performance. In the longitudinal analyses, 94.7% of participants consumed breakfast ≥ 4 days per week. Controlling for nine covariates, multivariate mixed models reported that compared to infrequent breakfast consumption, regular breakfast intake was associated with an increase of 5.54 points for verbal and 4.35 points for full IQ scores (p < 0.05). In our cross‐sectional analyses at age 12, consuming grain/rice or meat/egg 6–7 days per week was significantly associated with higher verbal, performance, and full‐scale IQs, by 3.56, 3.69, and 4.56 points, respectively (p < 0.05), compared with consuming grain/rice 0–2 days per week. Regular meat/egg consumption appeared to facilitate academic achievement (mean difference = 0.232, p = 0.043). No association was found between fruit/vegetable and dairy consumption and cognitive ability. In this 6‐year longitudinal study, regular breakfast habits are associated with higher IQ. Frequent grain/rice and meat/egg consumption during breakfast may be linked with improved cognitive function in youth

Hypertension: An Important But Reversible Cause of Systolic Dysfunction in a Cohort of Pediatric Patients.

Cardiac dysfunction due to hypertension (CDHTN) in pediatrics is not well described. We aimed to describe the presentation and outcomes of pediatric CDHTN and identify clinical features associated with resolution of dysfunction. A single-center retrospective cohort study of patients ≤ 21 years with CDHTN from January 2005-September 2020 was performed. Patients with systolic dysfunction without another cause, blood pressure \u3e 95th percentile, and physician judgment that dysfunction was secondary to hypertension were included. Demographics, clinical characteristics, echocardiographic findings, and outcomes were examined using Fisher\u27s exact and Mann-Whitney U tests. Multiple correspondence analysis was used to explore the relationship of resolution of dysfunction to clinical features. Thirty-four patients were analyzed at a median age of 10.9 (IQR 0.3-16.9) years. Patients were divided into groups \u3c 1 year (n = 12) and ≥ 1 year (n = 22). Causes of hypertension were varied by age, with renovascular disease most common in infants (42%) and medical renal disease most common in older patients (77%). Echocardiography demonstrated mild LV dilation (median LV end-diastolic z-score 2.6) and mild LV hypertrophy (median LV mass z-score 2.4). Most patients (81%) had resolution of dysfunction, particularly infants (92%). One patient died and one patient was listed for heart transplant. None required mechanical circulatory support (MCS). No clinical features were statistically associated with resolution of dysfunction. Hypertension is an important but reversible cause of systolic dysfunction in children. Patients are likely to recover with low mortality and low utilization of MCS or transplantation. Further studies are needed to confirm features associated with resolution of dysfunction

Trends in Ductus Arteriosus Stent Versus Blalock‐Taussig‐Thomas Shunt Use and Comparison of Cost, Length of Stay, and Short‐Term Outcomes in Neonates With Ductal‐Dependent Pulmonary Blood Flow: An Observational Study Using the Pediatric Health Information Systems Database

Background The modified Blalock‐Taussig‐Thomas shunt is the gold standard palliation for securing pulmonary blood flow in infants with ductal‐dependent pulmonary blood flow. Recently, the ductus arteriosus stent (DAS) has become a viable alternative. Methods and Results This was a retrospective multicenter study of neonates ≤30 days undergoing DAS or Blalock‐Taussig‐Thomas shunt placement between January 1, 2017 and December 31, 2020 at hospitals reporting to the Pediatric Health Information Systems database. We performed generalized linear mixed‐effects modeling to evaluate trends in intervention and intercenter variation, propensity score adjustment and inverse probability weighting with linear mixed‐effects modeling to analyze length of stay and cost of hospitalization, and generalized linear mixed modeling to analyze differences in 30‐day outcomes. There were 1874 subjects (58% male, 61% White) from 45 centers (29% DAS). Odds of DAS increased with time (odds ratio [OR] 1.23, annually, P<0.01 [95% CI, 1.10–1.38]) with significant intercenter variation (median OR, 3.81 [95% CI, 2.74–5.91]). DAS was associated with shorter hospital length of stay (ratio of geometric means, 0.76 [95% CI, 0.63–0.91]), shorter intensive care unit length of stay (ratio of geometric means, 0.77 [95% CI, 0.61–0.97]), and less expensive hospitalization (ratio of geometric means, 0.70 [95% CI, 0.56–0.87]). Intervention was not significantly associated with odds of 30‐day transplant‐free survival (OR,1.18 [95% CI, 0.70–1.99]) or freedom from catheter reintervention (OR, 1.02 [95% CI, 0.65–1.58]), but DAS was associated with 30‐day freedom from composite adverse outcome (OR, 1.51 [95% CI, 1.11–2.05]). Conclusions Use of DAS is increasing, but there is variability across centers. Though odds of transplant‐free survival and reintervention were not significantly different after DAS, and DAS was associated with shorter length of stay and lower in‐hospital costs