Effect of Copolymer Structure on Rare-Earth-Element Chelation Thermodynamics.

Rare-earth elements (REEs) are crucial to modern technology, leading to a high demand for materials capable of REE extraction and purification. Metal-chelating polymers (e.g., polycarboxylic acids, polyamines, and others) are particularly useful in these applications due to their synthetic accessibility and high selectivity. Copolymers with varied mole fractions of acrylic acid and methyl acrylate are synthesized and isothermal titration calorimetry (ITC) to measure the thermodynamics of REE binding for each material is used. Across a series of copolymer compositions, entropically driven binding thermodynamics (∆G, ∆H, and ∆S) that appear to be independent of χAcrylic Acid  are found. ITC stoichiometry data reveal that each copolymer requires between four and five repeat units to bind each REE. These data suggest that alterations in the copolymer structure do not affect the overall binding thermodynamics of REEs to these copolymers.

Understanding resistant hypertension.

ABSTRACT: Resistant hypertension affects about 17% of the US population. However, it is difficult to diagnose because of multiple factors that influence adequate treatment of BP, including patient lifestyle and comorbidities, improper therapeutic regimens, and secondary mechanisms. Possible causes of resistant hypertension include nonmodulator hypertension, which affects patients who have an inappropriate response to elevated sodium through the renin-angiotensin-aldosterone system. Early identification and frequent follow-up can help patients achieve BP goals more rapidly and may reduce morbidity and mortality associated with complications of hypertension, including cerebrovascular accident, cardiovascular disease, and kidney disease.

Teen Driving Education in a Pediatric Emergency Department: Effectiveness of a Toolkit.

OBJECTIVES: In the United States, the leading cause of death for adolescents aged 16 to 24 years is motor vehicle crashes, with Alabama ranked as the second-worst state in the nation for teen driving deaths. We sought to determine the efficacy of teenage driving education within the setting of the pediatric emergency department and to assess the driving habits of teenagers and their parents and their understanding of the Alabama Graduated Driver's License (GDL) law. METHODS: Surveys were administered to noncritically ill teenagers aged 13 to 19 years and their parents who presented to the children's emergency department. Participation was voluntary and anonymous. Presurveys were administered to assess driving habits and knowledge. Intervention was then given in the form of a "safe driving toolkit," followed by postsurveys to measure educational outcomes. Pre- and postsurvey data were then analyzed and compared using Epistat. RESULTS: A total of 41 parents, 2 grandparents, and 45 teenagers were enrolled in this study. An additional 47 teenagers answered a single curfew question at a teen driving event. Of all of the participants, 63% had never heard of the Alabama GDL law, and of that 63%, 37% had been enrolled in a driver's education course. A χ2 analysis revealed no significant difference between parents and teenagers having taken a driver's education course. Of the participants, 22% responded that they knew the specifics of the Alabama GDL law, with only 1 correct on all 3 counts. The most common item missed was the curfew for teenagers, with 4 believing it to be 8 pm, 14 believing it to be 9 pm, 23 believing it to be 10 pm, and 7 believing it to be 11 pm. Sixty-nine percent of the respondents correctly answered that there was to be no cellular telephone use while driving for teenagers with a GDL. More than 97.2% of participants, both parents and teens, reported learning new information from this study. CONCLUSIONS: The majority of participants enrolled were not aware of the Alabama GDL law, which has been in place since 2002. More than 97% of those surveyed were given new information during the education session. There is a strong need for further public education regarding the law and safe driving habits. Sixty-one percent of respondents believe that the teen curfew is earlier than the present curfew. The authors believe that this shows support for revising the curfew in the present law to an earlier time. Nighttime driving restrictions starting at 10 pm or earlier have been shown to result in greater reductions in motor vehicle crashes involving teenagers. Our study affirmed that teen driving education within the pediatric emergency department setting is efficacious.

The effect of anxiety and depression on symptoms attributed to atrial fibrillation.

BACKGROUND: Symptoms attributed to atrial fibrillation (AF) are nonspecific, and it remains unclear what influences perception of symptoms. Anxiety or depression may be important in modulating perception of AF symptoms. However, few longitudinal studies have addressed this effect. METHODS: A total of 378 patients with AF completed anxiety and depression severity questionnaires as well as AF symptom and frequency severity questionnaires. Patients were offered treatment strategies including catheter ablation or antiarrhythmic or rate-controlling medications. Patients were followed at 3-month intervals and completed follow-up questionnaires including repeat assessment of anxiety, depression, and AF symptoms. A method of generalized estimating equations was used for longitudinal analyses. RESULTS: Analysis revealed that increased anxiety or depression was associated with increased AF symptom severity (AFSS), after adjusting for potential confounders. In both unadjusted and adjusted follow-up analyses, antiarrhythmic drug therapy or catheter ablation reduced AFSS (P < 0.001). However, none of anxiety severity, depression severity, or the perception of AF frequency severity improved significantly with AF treatment. CONCLUSIONS: Our results extend previous studies demonstrating that anxiety and depression are associated with worsened AFSS. Antiarrhythmic drug therapy or catheter ablation reduces AFSS but does not affect depression and anxiety symptoms. To achieve more comprehensive AF symptom relief, treatment of both AF and psychological comorbidities may be beneficial.

Educational attainment is associated with atrial fibrillation symptom severity.

BACKGROUND: Atrial fibrillation (AF), the most common arrhythmia encountered in clinical practice, is often managed with a rhythm control strategy. Despite the emphasis on symptom relief as the motivation for a rhythm controlling strategy in AF, it remains unclear what factors affect the patient's experienced severity of AF symptoms. We hypothesize that demographic variables may affect AF symptom severity as many AF symptoms (palpitations, dyspnea, fatigue) are nonspecific and may require particular patient insight. METHODS: We assessed demographic variables, cardiac and noncardiac comorbidities, AF burden, and AF-specific self-reported symptom severity in a cohort of 300 outpatients with AF presenting to outpatient electrophysiology clinics. RESULTS: In unadjusted analyses, decreased educational attainment, unemployed working status, and non-Caucasian race were associated with worsened AF symptom severity. After adjusting for potential confounders, the association of decreased educational attainment with worsened AF symptom severity persisted. CONCLUSIONS: Possible links between these demographic features and AF symptom severity are socioeconomic status and health literacy. Further study into the relationship between educational attainment and AF symptom severity is warranted.

The RAB39B p.G192R mutation causes X-linked dominant Parkinson's disease.

OBJECTIVE: To identify the causal gene in a multi-incident U.S. kindred with Parkinson's disease (PD). METHODS: We characterized a family with a classical PD phenotype in which 7 individuals (5 males and 2 females) were affected with a mean age at onset of 46.1 years (range, 29-57 years). We performed whole exome sequencing on 4 affected and 1 unaffected family members. Sanger-sequencing was then used to verify and genotype all candidate variants in the remainder of the pedigree. Cultured cells transfected with wild-type or mutant constructs were used to characterize proteins of interest. RESULTS: We identified a missense mutation (c.574G > A; p.G192R) in the RAB39B gene that closely segregated with disease and exhibited X-linked dominant inheritance with reduced penetrance in females. The mutation occurred in a highly conserved amino acid residue and was not observed among 87,725 X chromosomes in the Exome Aggregation Consortium dataset. Sequencing of the RAB39B coding region in 587 familial PD cases yielded two additional mutations (c.428C > G [p.A143G] and c.624_626delGAG [p.R209del]) that were predicted to be deleterious in silico but occurred in families that were not sufficiently informative to assess segregation with disease. Experiments in PC12 and SK-N-BE(2)C cells demonstrated that p.G192R resulted in mislocalization of the mutant protein, possibly by altering the structure of the hypervariable C-terminal domain which mediates intracellular targeting. CONCLUSIONS: Our findings implicate RAB39B, an essential regulator of vesicular-trafficking, in clinically typical PD. Further characterization of normal and aberrant RAB39B function might elucidate important mechanisms underlying neurodegeneration in PD and related disorders.