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683 result(s) for "Gutierrez, Angela"
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Microfiltration Membrane Pore Functionalization with Primary and Quaternary Amines for PFAS Remediation: Capture, Regeneration, and Reuse
The widespread production and use of multi-fluorinated carbon-based substances for a variety of purposes has contributed to the contamination of the global water supply in recent decades. Conventional wastewater treatment can reduce contaminants to acceptable levels, but the concentrated retentate stream is still a burden to the environment. A selective anion-exchange membrane capable of capture and controlled release could further concentrate necessary contaminants, making their eventual degradation or long-term storage easier. To this end, commercial microfiltration membranes were modified using pore functionalization to incorporate an anion-exchange moiety within the membrane matrix. This functionalization was performed with primary and quaternary amine-containing polymer networks ranging from weak to strong basic residues. Membrane loading ranged from 0.22 to 0.85 mmol/g membrane and 0.97 to 3.4 mmol/g membrane for quaternary and primary functionalization, respectively. Modified membranes exhibited a range of water permeances within approximately 45–131 LMH/bar. The removal of PFASs from aqueous streams was analyzed for both “long-chain” and “short-chain” analytes, perfluorooctanoic acid and perfluorobutyric acid, respectively. Synthesized membranes demonstrated as high as 90% rejection of perfluorooctanoic acid and 50–80% rejection of perfluorobutyric acid after 30% permeate recovery. Regenerated membranes maintained the capture performance for three cycles of continuous operation. The efficiency of capture and reuse can be improved through the consideration of charge density, water flux, and influent contaminant concentration. This process is not limited by the substrate and, thus, is able to be implemented on other platforms. This research advances a versatile membrane platform for environmentally relevant applications that seek to help increase the global availability of safe drinking water.
Recent advances on iron oxide magnetic nanoparticles as sorbents of organic pollutants in water and wastewater treatment
The constant growth in population worldwide over the past decades continues to put forward the need to provide access to safe, clean water to meet human needs. There is a need for cost-effective technologies for water and wastewater treatment that can meet the global demands and the rigorous water quality standards and at the same maximizing pollutant efficiency removal. Current remediation technologies have failed in keeping up with these factors without becoming cost-prohibitive. Most recently, nanotechnology has been sought as the best alternative to increase access to water supplies by remediating those already contaminated and offering ways to access unconventional sources. The use of iron oxide magnetic nanoparticles as nanoadsorbents has led way to a new class of magnetic separation strategies for water treatment. This review focuses on highlighting some of the most recent advances in core-shell iron oxide magnetic nanoparticles and nanocomposites containing iron oxide nanoparticles currently being developed for water and wastewater treatment of organic pollutants. We discuss the novelty of these novel materials and the insight gained from their advances that can help develop cost-effective reusable technologies for scale-up and commercial use.
Morphological and genetic diversity of maize landraces along an altitudinal gradient in the Southern Andes
Maize ( Zea mays ssp. mays) is a major cereal crop worldwide and is traditionally or commercially cultivated almost all over the Americas. The North-Western Argentina (NWA) region constitutes one of the main diversity hotspots of the Southern Andes, with contrasting landscapes and a large number of landraces. Despite the extensive collections performed by the “Banco Activo de Germoplasma INTA Pergamino, Argentina” (BAP), most of them have not been characterized yet. Here we report the morphological and molecular evaluation of 30 accessions collected from NWA, along an altitudinal gradient between 1120 and 2950 meters above sea level (masl). Assessment of morphological variation in a common garden allowed the discrimination of two groups, which differed mainly in endosperm type and overall plant size. Although the groups retrieved by the molecular analyses were not consistent with morphological clusters, they showed a clear pattern of altitudinal structuring. Affinities among accessions were not in accordance with racial assignments. Overall, our results revealed that there are two maize gene pools co-existing in NWA, probably resulting from various waves of maize introduction in pre-Columbian times as well as from the adoption of modern varieties by local farmers. In conclusion, the NWA maize landraces preserved at the BAP possess high morphological and molecular variability. Our results highlight their potential as a source of diversity for increasing the genetic basis of breeding programs and provide useful information to guide future sampling and conservation efforts.
Risk score for cardiac surgery in active left-sided infective endocarditis
ObjectiveTo develop and validate a calculator to predict the risk of in-hospital mortality in patients with active infective endocarditis (IE) undergoing cardiac surgery.MethodsThousand two hundred and ninety-nine consecutive patients with IE were prospectively recruited (1996–2014) and retrospectively analysed. Left-sided patients who underwent cardiac surgery (n=671) form our study population and were randomised into development (n=424) and validation (n=247) samples. Variables statistically significant to predict in-mortality were integrated in a multivariable prediction model, the Risk-Endocarditis Score (RISK-E). The predictive performance of the score and four existing surgical scores (European System for Cardiac Operative Risk Evaluation (EuroSCORE) I and II), Prosthesis, Age ≥70, Large Intracardiac Destruction, Staphylococcus, Urgent Surgery, Sex (Female) (PALSUSE), EuroSCORE ≥10) and Society of Thoracic Surgeons’s Infective endocarditis score (STS-IE)) were assessed and compared in our cohort. Finally, an external validation of the RISK-E in a separate population was done.ResultsVariables included in the final model were age, prosthetic infection, periannular complications, Staphylococcus aureus or fungi infection, acute renal failure, septic shock, cardiogenic shock and thrombocytopaenia. Area under the receiver operating characteristic curve in the validation sample was 0.82 (95% CI 0.75 to 0.88). The accuracy of the other surgical scores when compared with the RISK-E was inferior (p=0.010). Our score also obtained a good predictive performance, area under the curve 0.76 (95% CI 0.64 to 0.88), in the external validation.ConclusionsIE-specific factors (microorganisms, periannular complications and sepsis) beside classical variables in heart surgery (age, haemodynamic condition and renal failure) independently predicted perioperative mortality in IE. The RISK-E had better ability to predict surgical mortality in patients with IE when compared with other surgical scores.
Development of Poly(acrylamide)-Based Hydrogel Composites with Powdered Activated Carbon for Controlled Sorption of PFOA and PFOS in Aqueous Systems
Per- and polyfluoroalkyl substances (PFAS) are anthropogenic compounds developed for various applications; some are connected to adverse health impacts including immunosuppression and higher susceptibility to some cancers. Current PFAS remediation treatments from aqueous sources include granular activated carbon (GAC) adsorption, membrane separation, and anion-exchange resin (AER) removal. Each has specific disadvantages, hence the need for a new and efficient technology. Herein, acrylamide-based hydrogel composites were synthesized with powdered activated carbon (PAC) and characterized to determine their affinity for PFAS. Physicochemical characterization included Fourier-Transform infrared spectroscopy (FTIR) to identify chemical composition, thermogravimetric analysis (TGA) to confirm PAC loading percentage, and aqueous swelling studies to measure the effect of crosslinking density. FTIR showed successful conversion of carbonyl and amine groups, and TGA analysis confirmed the presence of PAC within the network. Surface characterization also confirmed carbon-rich areas within composite networks, and the swelling ratio decreased with increasing crosslinking density. Finally, sorption of PFAS was detected via liquid chromatography with tandem mass spectrometry (LC-MS/MS), with removal efficiencies of up to 98% for perfluorooctanoic sulfonic acid (PFOS) and 96% for perfluorooctanoic acid (PFOA). The developed hydrogel composites exhibited great potential as advanced materials with tunable levers that can increase affinity towards specific compounds in water.
The Digital Divide Exacerbates Disparities in Latinx Recruitment for Alzheimer’s Disease and Related Dementias Online Education During COVID-19
Latinx adults experience a high burden of dementia. Given that modifiable factors drive dementia disparities, engaging Latinxs in Alzheimer’s disease and related dementias (ADRD) education is critical to address dementia burden among this aging population. Yet, no studies have documented the role of the COVID-19 pandemic on dementia education among Latinxs. This study: (1) elucidates the recruitment and retention processes targeting Latinxs for online educational events during the pandemic; (2) describes facilitators/barriers to participation; and (3) offers lessons learned. We developed online dementia-focused workshops (English and Spanish) and employed a cold-calling approach to invite Latinx participants enrolled in clinical studies (N = 209). Bivariate tests assessed demographic and cognitive differences between those who recruiters did (n = 60) and did not (n = 149) successfully engage. Frequency counts assessed participants’ technological access. Only 8/209 attended the online events; all held university degrees, most reported English as their primary language, and none experienced cognitive impairment. Results underscore how educational attainment, cognitive impairment, language preference, and age intersect to shape recruitment in dementia-focused online education. To promote healthy aging and to ameliorate dementia disparities, barriers to online engagement among older Spanish-speaking Latinxs with cognitive impairment and low educational attainment must be addressed.
Mentoring Experiences and Publication Productivity among Early Career Biomedical Investigators and Trainees
Objective: To identify which mentoring domains influence publication productivity among early career researchers and trainees and whether publication productivity differs between underrepresented minority (URM) and well-represented groups (WRGs). The mentoring aspects that promote publica­tion productivity remain unclear. Advancing health equity requires a diverse workforce, yet URM trainees are less likely to publish and URM investigators are less likely to ob­tain federal research grants, relative to WRG counterparts.Participants: Early career biomedical investigators and trainees from the National Research Mentoring Network (NRMN), N=115.Methods: A mentoring-focused online follow-up survey was administered to respondents of the NRMN Annual Survey who self-identified as mentees. Publications were identified from a public database and validated with participant CV data. Bivariate and multivariate analyses tested the as­sociations of publication productivity with mentoring domains.Results: URM investigators and trainees had fewer publications (M = 7.3) than their WRG counterparts (M = 13.8). Controlling for career stage and social characteristics, those who worked on funded projects, and received grant-writing or research mentorship, had a higher probability of any publications. Controlling for URM status, gender, and career stage, mentorship on grant-writing and funding was positively as­sociated with publication count (IRR=1.72). Holding career stage, gender, and mentor­ing experiences constant, WRG investigators and trainees had more publications than their URM counterparts (IRR=1.66).Conclusions: Grant-writing mentorship is particularly important for publica­tion productivity. Future research should investigate whether grant-writing mentor­ship differentially impacts URM and WRG investigators and should investigate how and why grant-writing mentorship fosters increased publication productivity. Ethn Dis. 2021;31(2):273-282; doi:10.18865/ed.31.2.273
The Impact of Solution Ionic Strength, Hardness, and pH on the Sorption Efficiency of Polychlorinated Biphenyls in Magnetic Nanocomposite Microparticle (MNM) Gels
Environmental conditions of groundwater and surface water greatly vary as a function of location. Factors such as ionic strength, water hardness, and solution pH can change the physical and chemical properties of the nanocomposites used in remediation and the pollutants of interest. In this work, magnetic nanocomposite microparticle (MNM) gels are used as sorbents for remediation of PCB 126 as model organic contaminant. Three MNM systems are used: curcumin multiacrylate MNMs (CMA MNMs), quercetin multiacrylate MNMs (QMA MNMs), and polyethylene glycol-400-dimethacrylate MNMs (PEG MNMs). The effect of ionic strength, water hardness, and pH were studied on the sorption efficiency of the MNMs for PCB 126 by performing equilibrium binding studies. It is seen that the ionic strength and water hardness have a minimal effect on the MNM gel system sorption of PCB 126. However, a decrease in binding was observed when the pH increased from 6.5 to 8.5, attributed to anion-π interactions between the buffer ions in solution and the PCB molecules as well as with the aromatic rings of the MNM gel systems. Overall, the results indicate that the developed MNM gels can be used as magnetic sorbents for polychlorinated biphenyls in groundwater and surface water remediation, provided that the solution pH is controlled.
When Resilience Becomes Risk: A Latent Class Analysis of Psychosocial Resources and Allostatic Load Among African American Men
There is a well-established link between psychosocial risks and psychological health among African American (AA) men. Yet, the psychosocial sources and physical health consequences of resilience (i.e., the ability to maintain good health despite adversity) remain underexplored. Using data from 283 AA men in the Nashville Stress and Health Study, the present study investigated the links between psychosocial resilience and allostatic load (AL), a biological indicator of physiological dysregulation. Latent class analysis (LCA) identified distinct resilience profiles comprising eight psychosocial resources across four categories: coping strategies, sense of control, racial identity, and social support. Analysis of variance (ANOVA) tests determined significant class differences in men’s AL scores. LCA results confirm a four-class model was the best fit: Class 1 (high resources, 32%), Class 2 (high coping but low control, 13%), Class 3 (low resources but high racial identity, 20%), and Class 4 (low resources but high mastery, 34%). Results reveal lower AL (better health) among Classes 1 (m = 0.35) and 4 (m = 0.31) and higher AL (worse health) among Classes 2 (m = 0.44) and 3 (m = 0.44). Findings indicate that the “quality” rather than the “quantity” of psychosocial resources matters for physical health among AA men, as positive health outcomes were observed among both low- and high-resource classes. Results suggest different resource combinations produce distinct patterns of resilience among AA men and underscore the need to further elucidate complex resilience processes among this population.
Loneliness, Cardiovascular Disease, and Diabetes Prevalence in the Hispanic Community Health Study/Study of Latinos Sociocultural Ancillary Study
The relationship between loneliness and both cardiovascular disease (CVD) and diabetes mellitus (DM) has been understudied in U.S. Hispanics, a group at high risk for DM. We examined whether loneliness was associated with CVD and DM, and whether age, sex, marital status, and years in U.S moderated these associations. Participants were 5,313 adults (M (SD) age = 42.39 (15.01)) enrolled in the Hispanic Community Health Study/Study of Latinos Sociocultural Ancillary Study. Loneliness was assessed via the 3-item Revised UCLA Loneliness Scale. Level of reported loneliness was low. Loneliness was significantly associated with CVD: OR 1.10 (CI 1.01–1.20) and DM: OR 1.08 (CI 1.00–1.16) after adjusting for depression, demographics, body mass index, and smoking status. Age, sex, marital status, and years in U.S. did not moderate associations. Given that increased loneliness is associated with higher cardiometabolic disease prevalence beyond depressive symptoms, regardless of age, sex, marital status, or years in the U.S., Hispanic adults experiencing high levels of loneliness may be a subgroup at particularly elevated risk for CVD and DM.