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1.
J Sex Marital Ther ; 50(4): 527-541, 2024.
Article in English | MEDLINE | ID: mdl-38567544

ABSTRACT

This study examines dyadic data from 299 married and 242 cohabiting Black heterosexual couples in the United States (an understudied cross-section of the population) and assesses individual (actor) effects as well as couple (partner) effects of sexual sanctification and relationship satisfaction. Higher levels of sexual sanctification were associated with higher levels of relationship satisfaction for women and men in the actor effects, but no significant associations were found in the partner effects for couples. Additionally, initial findings suggest that sexual sanctification may act as a relational protective factor for Black married and cohabiting couples. Implications for further research as well as practical applications for clergy, therapists, and practitioners working with Black heterosexual couples in sexual relationships are also discussed.


Subject(s)
Black or African American , Heterosexuality , Personal Satisfaction , Sexual Partners , Humans , Male , Female , Heterosexuality/psychology , Adult , Black or African American/psychology , Sexual Partners/psychology , United States , Interpersonal Relations , Sexual Behavior/psychology , Middle Aged , Spouses/psychology , Marriage/psychology
2.
Sci Total Environ ; 905: 166957, 2023 Dec 20.
Article in English | MEDLINE | ID: mdl-37704140

ABSTRACT

Fungi are key players in terrestrial organic matter (OM) degradation, but little is known about their role in marine environments. Here we compared the degradation of kelp (Ecklonia radiata) in mesocosms with and without fungicides over 45 days. The aim was to improve our understanding of the vital role of fungal OM degradation and remineralisation and its relevance to marine biogeochemical cycles (e.g., carbon, nitrogen, sulfur, or volatile sulfur). In the presence of fungi, 68 % of the kelp detritus degraded over 45 days, resulting in the production of 0.6 mol of dissolved organic carbon (DOC), 0.16 mol of dissolved inorganic carbon (DIC), 0.23 mol of total alkalinity (TA), and 0.076 mol of CO2, which was subsequently emitted to the atmosphere. Conversely, when fungi were inhibited, the bacterial community diversity was reduced, and only 25 % of the kelp detritus degraded over 45 days. The application of fungicides resulted in the generation of an excess amount of 1.5 mol of DOC, but we observed only 0.02 mol of DIC, and 0.04 mol of TA per one mole of kelp detritus, accompanied by a CO2 emission of 0.081 mol. In contrast, without fungi, remineralisation of kelp detritus to DIC, TA, dimethyl sulfide (DMS), dimethylsulfoniopropionate (DMSP) and methanethiol (MeSH) was significantly reduced. Fungal kelp remineralisation led to a remarkable 100,000 % increase in DMSP production. The observed substantial changes in sediment chemistry when fungi are inhibited highlight the important biogeochemical role of fungal remineralisation, which likely plays a crucial role in defining coastal biogeochemical cycling, blue carbon sequestration, and thus climate regulation.


Subject(s)
Fungicides, Industrial , Kelp , Dissolved Organic Matter , Carbon Dioxide , Sulfur/metabolism , Fungi/metabolism , Carbon
3.
J Marital Fam Ther ; 49(4): 899-917, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37649260

ABSTRACT

Despite the common use of religious buffers, African Americans are disproportionately affected by depressive symptoms. Communal coping may serve as one factor in helping religious African American couples alleviate the symptoms of depression. This study examines the association between relational sanctification and depressive symptoms as mediated by the communal coping of 467 African American married and cohabiting couples. Data from the sampled couples were analyzed using a common fate model, and analyses revealed higher scores on the measure of sanctification were associated with more communal coping; more communal coping was associated with fewer depressive symptoms among women and men, and communal coping acted as a mediator between relational sanctification and depressive symptoms in both partners. Findings from this study underscore the importance of considering how the religiosity and cooperative action of African American couples relate to depressive symptoms.

4.
J Phys Chem Lett ; 14(19): 4517-4523, 2023 May 18.
Article in English | MEDLINE | ID: mdl-37159248

ABSTRACT

For more than 150 years, our understanding of solid-phase mineral formation from dissolved constituent ions in aqueous environments has been dominated by classical nucleation theory (CNT). However, an alternative paradigm known as non-classical nucleation theory (NCNT), characterized by the existence of thermodynamically stable and highly hydrated ionic "prenucleation clusters" (PNCs), is increasingly invoked to explain mineral nucleation, including the formation of calcium carbonate (CaCO3) minerals in aqueous conditions, which is important in a wide range of geological and biological systems. While the existence and role of PNCs in aqueous nucleation processes remain hotly debated, we show, using in situ small-angle X-ray scattering (SAXS), that nanometer-sized clusters are present in aqueous CaCO3 solutions ranging from thermodynamically under- to supersaturated conditions regarding all known mineral phases, thus demonstrating that CaCO3 mineral formation cannot be explained solely by CNT under the conditions examined.

5.
Environ Toxicol Chem ; 42(2): 303-316, 2023 02.
Article in English | MEDLINE | ID: mdl-36416265

ABSTRACT

The toxicity of iron(III) in fresh waters has been detected at concentrations above the iron solubility limit, indicating a contribution of colloidal and particulate forms of iron(III) to the toxicity response. Current water quality guideline values for iron in fresh water are based on analytical determinations of filterable or total iron. Filtration, however, can underestimate bioavailable iron by retaining some of the colloidal fraction, and total determinations overestimate bioavailable iron measurements by recovering fractions of low bioavailability from suspended solids (e.g., iron oxides and oxyhydroxides) naturally abundant in many surface waters. Consequently, there is a need for an analytical method that permits the determination of a bioavailable iron fraction, while avoiding false-negative and false-positive results. Ideally, a measurement technique is required that can be readily applied by commercial laboratories and field sampling personnel, and integrated into established regulatory schemes. The present study investigated the performance of pH 2 and pH 4 extractions to estimate a bioavailable iron(III) fraction in synthetic water samples containing iron phases of different reactivities. The effects of aging on fresh precipitates were also studied. The total recoverable, 0.45-µm filtered, and pH 4 extractable fractions did not discriminate iron phases and age groups satisfactorily. Contrastingly, the pH 2 extraction showed specificity toward iron phases and aging (0.5-2-h interval). Extraction times above 4 h and up to 16 h equally recovered >90% of the spiked iron regardless of its age. Furthermore, <1% of the well-mineralized iron was targeted. The present study shows that a pH 2 dilute-acid extraction is a suitable candidate method to operationally define iron fractions of higher bioavailability avoiding false-negative and false-positive results. Environ Toxicol Chem 2023;42:303-316. © 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.


Subject(s)
Iron , Water Pollutants, Chemical , Ferric Compounds , Biological Availability , Fresh Water , Water Quality , Water Pollutants, Chemical/toxicity
6.
Redox Biol ; 52: 102285, 2022 06.
Article in English | MEDLINE | ID: mdl-35364435

ABSTRACT

Reactive oxygen species (ROS) are omnipresent in the ocean, originating from both biological (e.g., unbalanced metabolism or stress) and non-biological processes (e.g. photooxidation of colored dissolved organic matter). ROS can directly affect the growth of marine organisms, and can also influence marine biogeochemistry, thus indirectly impacting the availability of nutrients and food sources. Microbial communities and evolution are shaped by marine ROS, and in turn microorganisms influence steady-state ROS concentrations by acting as the predominant sink for marine ROS. Through their interactions with trace metals and organic matter, ROS can enhance microbial growth, but ROS can also attack biological macromolecules, causing extensive modifications with deleterious results. Several biogeochemically important taxa are vulnerable to very low ROS concentrations within the ranges measured in situ, including the globally distributed marine cyanobacterium Prochlorococcus and ammonia-oxidizing archaea of the phylum Thaumarchaeota. Finally, climate change may increase the amount of ROS in the ocean, especially in the most productive surface layers. In this review, we explore the sources of ROS and their roles in the oceans, how the dynamics of ROS might change in the future, and how this change might impact the ecology and chemistry of the future ocean.


Subject(s)
Ammonia , Microbiota , Oceans and Seas , Oxidation-Reduction , Reactive Oxygen Species
7.
ANZ J Surg ; 92(3): 341-345, 2022 03.
Article in English | MEDLINE | ID: mdl-35112443

ABSTRACT

BACKGROUND: Rural exposure of long durations during clinical training is positively associated with rural career uptake and is a central strategy to addressing the geographical maldistribution of Australia's surgical workforce. However, the incentives and barriers to trainees undergoing surgical training preferencing repeated rural placements in Australia are not well understood. This qualitative study explores the incentives and barriers that influence preference for rural placements during surgical training in Australia. METHODS: This qualitative study employed online semi-structured in-depth interviews. Participants were recruited using an online survey, and interviews were conducted between October 2020 and November 2020. Transcripts were transcribed and de-identified, and thematically analysed. RESULTS: Twenty-nine semi-structured interviews were conducted with trainees and 12 Fellows. Twenty-five participants identified as male, and four identified as female. Four main incentives identified were: (1) broad scope of learning opportunities, (2) quality of supervision, (3) positive work environment and (4) lifestyle. Seven barriers identified were: (1) inadequate preparation for placement, (2) limited case mix to support learning outcomes, (3) lack of formally structured learning opportunities, (4) workload and safe hours concerns, (5) lack of peer support, (6) childcare and educational needs and (7) partner career development. CONCLUSION: The strategy of encouraging trainees to undertake rural placements to address the maldistribution of the surgical workforce should include initiatives that support learning outcomes across their training levels. In addition, improving trainees' ability to prepare adequately for placements may also improve the number and duration of rural placements trainees undertake during their training.


Subject(s)
Motivation , Rural Health Services , Australia , Female , Humans , Male , Qualitative Research , Workforce
8.
Sci Total Environ ; 817: 153023, 2022 Apr 15.
Article in English | MEDLINE | ID: mdl-35031380

ABSTRACT

Sewage sludges are a rich underused source of phosphorus (P) which contributes to environmental degradation, yet if recaptured, could return significant amounts of P to agricultural systems. Hydrothermal carbonisation (HTC) can efficiently recover P, with the added ability to transform P species into potentially more desirable forms for direct application to crops. P dynamics in hydrochars have primarily examined P speciation and chemical extractability as indicators of P bioavailability, but few studies directly evaluate the agronomic effectiveness of hydrochars as P fertilisers. As such, there is a clear need to assess the suitability of hydrochar as a source of bioavailable P in plant systems and the influence of HTC synthesis conditions. Response Surface Modelling of HTC synthesis conditions (pH, temperature and time), revealed initial pH significantly influence P distribution. Mild conditions of 180 °C for 30 min at pH 8.0 maximised P recovery (99%) along with carbon (62%) and nitrogen (43%) in hydrochars. Systematic characterisation of hydrochar P by chemical extraction and P L2,3-edge X-ray absorption near edge spectroscopy revealed H2O, NaHCO3 and NaOH- P fractions were significantly (p < 0.05) reduced in all hydrochars, while HCl-P fraction increased with HTC temperatures at pH 7. In contrast, P L2,3-edge XANES spectra were remarkably similar in raw sludges and corresponding hydrochars, regardless of HTC temperature or pH, revealing P was predominantly present as ferric phosphate with some hydroxyapatite. Multiple linear regression modelling suggested a significant relationship between chemical extractability and P bioavailability to wheat present in the raw sludges and hydrochars. This research provides further insight into the potential to use hydrothermal treatment for recovery and agricultural reuse of P, the importance of operational conditions on P transformation and the relationship between P speciation and bioavailability. The value of sewage sludge in a more sustainable global P cycle is also highlighted.


Subject(s)
Phosphorus , Sewage , Carbon , Fertilization , Nitrogen , Temperature
9.
Front Microbiol ; 12: 726138, 2021.
Article in English | MEDLINE | ID: mdl-34733248

ABSTRACT

Cellulose and chitin are the most abundant polymeric, organic carbon source globally. Thus, microbes degrading these polymers significantly influence global carbon cycling and greenhouse gas production. Fungi are recognized as important for cellulose decomposition in terrestrial environments, but are far less studied in marine environments, where bacterial organic matter degradation pathways tend to receive more attention. In this study, we investigated the potential of fungi to degrade kelp detritus, which is a major source of cellulose in marine systems. Given that kelp detritus can be transported considerable distances in the marine environment, we were specifically interested in the capability of endophytic fungi, which are transported with detritus, to ultimately contribute to kelp detritus degradation. We isolated 10 species and two strains of endophytic fungi from the kelp Ecklonia radiata. We then used a dye decolorization assay to assess their ability to degrade organic polymers (lignin, cellulose, and hemicellulose) under both oxic and anoxic conditions and compared their degradation ability with common terrestrial fungi. Under oxic conditions, there was evidence that Ascomycota isolates produced cellulose-degrading extracellular enzymes (associated with manganese peroxidase and sulfur-containing lignin peroxidase), while Mucoromycota isolates appeared to produce both lignin and cellulose-degrading extracellular enzymes, and all Basidiomycota isolates produced lignin-degrading enzymes (associated with laccase and lignin peroxidase). Under anoxic conditions, only three kelp endophytes degraded cellulose. We concluded that kelp fungal endophytes can contribute to cellulose degradation in both oxic and anoxic environments. Thus, endophytic kelp fungi may play a significant role in marine carbon cycling via polymeric organic matter degradation.

10.
J Fam Psychol ; 35(8): 1128-1137, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34292033

ABSTRACT

Throughout history, African Americans have endured much, and their experiences with discrimination and racism continue today. Despite ongoing challenges, African Americans have also shown their resilience. Religion and spirituality are two of the largest resources of resilience that African Americans employ. However, little is known about the role of religion and spirituality within African American couple relationships. Using dyadic data from 292 married and 233 cohabiting African American couples, we examined the impact of sanctification of the couple relationship on communal coping within the Actor Partner Interdependence Model. Significant actor effects were found between relational sanctification and communal coping for both married and cohabiting men and women. There was a significant partner effect between married men's relational sanctification and married women's communal coping. However, no other significant partner effects were found. (PsycInfo Database Record (c) 2021 APA, all rights reserved).


Subject(s)
Black or African American , Men , Adaptation, Psychological , Family Characteristics , Female , Humans , Male , Marriage
12.
J Policy Model ; 42(4): 850-859, 2020.
Article in English | MEDLINE | ID: mdl-32834234

ABSTRACT

The empirical evidence on the growth effects of import tariffs is sparse in the literature, notwithstanding strong views held by the public and politicians. Using an annual panel of macroeconomic data for 151 countries over 1963-2014, we find that tariff increases are associated with an economically and statistically sizeable and persistent decline in output growth. Thus, fears that the ongoing trade war may be costly for the world economy in terms of foregone output growth are justified.

13.
Article in English | MEDLINE | ID: mdl-32665206

ABSTRACT

Oral diseases, including cancers, affect 3.5 billion people globally and remain largely untreated in low- to middle-income countries because of lack of resources. In Papua New Guinea (PNG), oral cancer has, for many decades, been identified as the most common cancer in men, but as the GLOBOCAN 2018 data are estimates extrapolated from surrounding countries, the real prevalence of this disease is not known. The PNG National Health Plan (2011-2020) highlights the need to improve health care, but oral health is not identified as a priority. Alcohol, tobacco, and areca nut/betel quid, which are the social and commercial determinants of oral cancer, are common risk factors, and there are robust data linking these risk factors to oral cancer in PNG. Our recent Global Challenges Research Fund Workshop on Oral Cancer, held in Port Moresby, PNG, brought together a number of researchers in oral cancer epidemiology and translational science with clinicians from PNG to assess the current situation and plan ways to move forward. In this article, we will review the literature on oral cancer in PNG, and make suggestions as to how, collaboratively, we can address the issues identified, ultimately, for the benefit of the people of PNG.


Subject(s)
Mouth Diseases , Mouth Neoplasms , Areca , Humans , Male , Mouth Neoplasms/epidemiology , Papua New Guinea/epidemiology , Prevalence
14.
PLoS One ; 14(12): e0225883, 2019.
Article in English | MEDLINE | ID: mdl-31851689

ABSTRACT

This study estimates the effect of data sharing on the citations of academic articles, using journal policies as a natural experiment. We begin by examining 17 high-impact journals that have adopted the requirement that data from published articles be publicly posted. We match these 17 journals to 13 journals without policy changes and find that empirical articles published just before their change in editorial policy have citation rates with no statistically significant difference from those published shortly after the shift. We then ask whether this null result stems from poor compliance with data sharing policies, and use the data sharing policy changes as instrumental variables to examine more closely two leading journals in economics and political science with relatively strong enforcement of new data policies. We find that articles that make their data available receive 97 additional citations (estimate standard error of 34). We conclude that: a) authors who share data may be rewarded eventually with additional scholarly citations, and b) data-posting policies alone do not increase the impact of articles published in a journal unless those policies are enforced.


Subject(s)
Editorial Policies , Information Dissemination , Politics , Publishing , Social Problems , Humans
15.
Chemosphere ; 234: 690-701, 2019 Nov.
Article in English | MEDLINE | ID: mdl-31234086

ABSTRACT

Iron (oxyhydr)oxides (FeOx) control retention of dissolved nutrients and contaminants in aquatic systems. However, FeOx structure and reactivity is dependent on adsorption and incorporation of such dissolved species, particularly oxyanions such as phosphate and silicate. These interactions affect the fate of nutrients and metal(loids), especially in perturbed aquatic environments such as eutrophic coastal systems and environments impacted by acid mine drainage. Altered FeOx reactivity impacts sedimentary nutrient retention capacity and, eventually, ecosystem trophic state. Here, we explore the influence of phosphate (P) and silicate (Si) on FeOx structure and reactivity. Synthetic, poorly crystalline FeOx with adsorbed and coprecipitated phosphate or silicate at low but environmentally relevant P/Fe or Si/Fe ratios (0.02-0.1 mol mol-1) was prepared by base titration of Fe(III) solutions. Structural characteristics of FeOx were investigated by X-ray diffraction, synchrotron-based X-ray absorption spectroscopy and high-energy X-ray scattering. Reactivity of FeOx was assessed by kinetic dissolution experiments under acidic (dilute HCl, pH 2) and circum-neutral reducing (bicarbonate-buffered ascorbic acid, pH 7.8, Eh ∼ -300 mV) conditions. At these loadings, phosphate and silicate coprecipitation had only slight impact on local and intermediate-ranged FeOx structure, but significantly enhanced the dissolution rate of FeOx. Conversely, phosphate and silicate adsorption at similar loadings resulted in particle surface passivation and decreased FeOx dissolution rates. These findings indicate that varying nutrient loadings and different interaction mechanisms between anions and FeOx (adsorption versus coprecipitation) can influence the broader biogeochemical functioning of aquatic ecosystems by impacting the structure and reactivity of FeOx.


Subject(s)
Ecosystem , Environmental Pollutants/chemistry , Ferric Compounds/chemistry , Phosphates/chemistry , Silicates/chemistry , Water Pollutants, Chemical/chemistry , Adsorption , Environmental Pollutants/analysis , Kinetics , Phosphates/analysis , Silicates/analysis , Solubility , Water Pollutants, Chemical/analysis
16.
Environ Toxicol Chem ; 37(4): 1104-1114, 2018 04.
Article in English | MEDLINE | ID: mdl-29149480

ABSTRACT

Currently toxicity data for iron (Fe) in seawater are limited; furthermore, these data are of poor quality as a result of the importance of Fe solubility in test solutions being overlooked. The present study characterized the solubility and lability of Fe(III) in seawater and then examined the effects of Fe(III) on the fertilization success and larval survival of the tropical marine scleractinian corals Acropora spathulata and Platygyra daedalea. We present the first assessment of the effects of Fe on the early life stages of scleractinian corals. Concentrations of both soluble and labile forms of Fe were very low, with dissolved Fe concentrations ≤0.195 mg/L in bioassay test solutions and chemical determinations revealing labile Fe concentrations ≤1.21 mg/L. For fertilization experiments, the median effect concentration (EC50) value for total Fe was 25 mg/L for the most sensitive species, P. daedalea, whereas the EC50 values for A. spathulata ranged between 40 and 66 mg/L. The median lethal concentration value for P. daedalea larval survival was 47 mg/L Fe after 72-h exposure. We provide Fe toxicity data for tropical marine keystone species that could be used to help generate more reliable guideline values for Fe in marine waters. Environ Toxicol Chem 2018;37:1104-1114. © 2017 SETAC.


Subject(s)
Anthozoa/growth & development , Iron/toxicity , Life Cycle Stages/drug effects , Seawater/chemistry , Toxicity Tests , Animals , Anthozoa/drug effects , Biological Assay , Fertilization/drug effects , Larva/drug effects , Silicon Dioxide/toxicity , Solutions , Water Pollutants, Chemical/toxicity
17.
Environ Pollut ; 228: 190-200, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28535490

ABSTRACT

There is growing concern about the combined effects of multiple human-induced stressors on biodiversity. In particular, there are substantial knowledge gaps about the combined effects of existing stressors (e.g. pollution) and predicted environmental stress from climate change (e.g. ocean warming). We investigated the impacts of ocean warming and engineered nanoparticles (nano-zinc oxide, nZnO) on larvae of a cosmopolitan tropical sea urchin, Tripneustes gratilla. Larval T. gratilla were exposed to all combinations of three temperatures, 25, 27 and 29 °C (current SST and near-future predicted warming of +2 and + 4 °C) and six concentrations of nZnO (0, 0.001, 0.01, 0.1, 1 and 10 mg nZnO·L-1). These stressors had strong interactive effects on fertilization, gastrulation and normal development of 5 day old larvae. High concentrations of nZnO had a negative effect, but this impact was less pronounced for sea urchins reared at their preferred temperature of 27 °C compared to 25 or 29 °C. Larval growth was also impacted by combined stress of elevated temperature and nZnO. Subsequent measurement of the dissolution and aggregation of nZnO particles and the direct effect of Zn2+ ions on larvae, suggest the negative effects of nZnO on larval development and growth were most likely due to Zn2+ ions. Our results demonstrate that marine larvae may be more resilient to stressors at optimal temperatures and highlight the potential for ocean warming to exacerbate the effects of pollution on marine larvae.


Subject(s)
Climate Change , Larva/drug effects , Nanoparticles/toxicity , Seawater/chemistry , Zinc/toxicity , Animals , Hydrogen-Ion Concentration , Larva/growth & development , Larva/physiology , Oceans and Seas , Sea Urchins , Stress, Physiological , Temperature , Zinc Oxide
18.
Am J Cardiol ; 118(1): 40-3, 2016 07 01.
Article in English | MEDLINE | ID: mdl-27178330

ABSTRACT

Coronary artery bypass grafting (CABG) is commonly performed to treat ischemic heart disease, but long-term benefits are limited by failed patency of bypass grafts. Both statin medications and aspirin hold class I indications for all post-CABG patients and should be continued indefinitely unless contraindications exist. Unfortunately, there are limited data regarding long-term usage of these essential medications. We assessed the utilization rates of statins and aspirin among post-CABG patients referred for coronary angiography. Analysis of post-CABG patients presenting to Thomas Jefferson University for a cardiac catheterization procedure at least 3 years after surgery was performed. Inpatient and outpatient records were reviewed to assess prescribing patterns of these medications, as well as other pertinent clinical and laboratory data. The study population was 381 consecutive patients presenting at a mean of 11 ± 6 years from CABG. Mean age was 69 ± 11 years and 78% were men. A total 67% of patients were being prescribed a statin, whereas 75% were prescribed aspirin. Only 52% were prescribed both at the time of catheterization. Patients prescribed a statin had a significantly lower mean low-density lipoprotein (87 vs 106 [p <0.01]) and total cholesterol values (151 vs 162 [p <0.01]). A total of 35% of patients had low-density lipoprotein ≥100. Only 43% of saphenous vein grafts in the patients not on statin medications remained patent. In conclusion, long-term statin and aspirin use after CABG remains suboptimal despite clear guideline recommendations and clinical trial evidence of their effectiveness.


Subject(s)
Aspirin/therapeutic use , Coronary Artery Bypass , Coronary Artery Disease/therapy , Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use , Platelet Aggregation Inhibitors/therapeutic use , Aged , Cardiac Catheterization , Coronary Angiography , Coronary Artery Disease/complications , Coronary Artery Disease/mortality , Drug Administration Schedule , Female , Humans , Male , Middle Aged , Retrospective Studies
19.
Langmuir ; 30(12): 3548-56, 2014 Apr 01.
Article in English | MEDLINE | ID: mdl-24601665

ABSTRACT

Small angle X-ray scattering (SAXS) measurements coupled to a stopped-flow device has permitted the observation of the kinetics of Fe(III) oxyhydroxide (FeOx) formation and transformation from around 1 s to 30 min after initiation under environmentally relevant conditions at pH 3. The Unified Model approach was used to determine the evolution of multiple key parameters (particle scattering mass, mean particle volume, particle concentration, particle dimensionality, and particle size) for two separate structural levels as a function of time, with the results obtained enabling clarification of the mechanisms underlying FeOx formation and transformation under these conditions. Colloidal primary particles (radius of gyration 2-10 nm) that were observable by SAXS formed within 1 s of stopping the flow and subsequently grew over several minutes, first by cluster-cluster addition and then by a monomer-addition mechanism. Aggregation of these primary particles via a secondary cluster-cluster addition mechanism simultaneously resulted in a distinct population of larger (25-40 nm radius of gyration) secondary particles. The primary particles evolved into compact spheroidal forms with fractally rough surfaces, while the secondary particles were relatively open mass fractal structures. Comparison of the observed rates of these processes with those predicted for Fe polymerization indicates that kinetics of primary particle formation were likely controlled initially by rates of exchange between water molecules coordinated with Fe and those in the bulk solution. These findings provide new insights into the mechanisms underlying FeOx formation and transformation, and the kinetics of these mechanisms, at pH 3.

20.
Expert Rev Clin Pharmacol ; 6(5): 581-7, 2013 Sep.
Article in English | MEDLINE | ID: mdl-24070097

ABSTRACT

The need to evaluate medicines for children is widely acknowledged due to pervasive unlicensed medicine use in the pediatric setting. The EU Paediatric Regulation was developed to address these considerations, which subsequently led to the establishment of the National Institute of Health Research (NIHR) Medicines for Children Research Network (MCRN) in England. MCRN supports public and industry studies, and facilitates feasibility, site setup, recruitment and other services. The MCRN and other networks are members of the European Network of Paediatric Research at the European Medicines Agency (Enpr-EMA). Enpr-EMA was established to foster and coordinate research, and develop collaborations across Europe. MCRN works with Enpr-EMA, industry and others to improve the conduct of research for the benefit of children's health.


Subject(s)
Biomedical Research/organization & administration , Clinical Trials as Topic/methods , Pediatrics/methods , Biomedical Research/legislation & jurisprudence , Biomedical Research/methods , Biomedical Research/trends , Child , Clinical Trials as Topic/legislation & jurisprudence , Clinical Trials as Topic/trends , Government Agencies , Government Regulation , Humans , Pediatrics/legislation & jurisprudence , Pediatrics/organization & administration , Pediatrics/trends , United Kingdom
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