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1.
Environ Sci Technol ; 58(16): 7186-7195, 2024 Apr 23.
Article in English | MEDLINE | ID: mdl-38598770

ABSTRACT

Remediation of large and dilute plumes of groundwater contaminated by oxidized pollutants such as chromate is a common and difficult challenge. Herein, we show that in situ formation of FeS nanoparticles (using dissolved Fe(II), S(-II), and natural organic matter as a nucleating template) results in uniform coating of aquifer material to create a regenerable reactive zone that mitigates Cr(VI) migration. Flow-through columns packed with quartz sand are amended first with an Fe2+ solution and then with a HS- solution to form a nano-FeS coating on the sand, which does not hinder permeability. This nano-FeS coating effectively reduces and immobilizes Cr(VI), forming Fe(III)-Cr(III) coprecipitates with negligible detachment from the sand grains. Preconditioning the sand with humic or fulvic acid (used as model natural organic matter (NOM)) further enhances Cr(VI) sequestration, as NOM provides additional binding sites of Fe2+ and mediates both nucleation and growth of FeS nanoparticles, as verified with spectroscopic and microscopic evidence. Reactivity can be easily replenished by repeating the procedures used to form the reactive coating. These findings demonstrate that such enhancement of attenuation capacity can be an effective option to mitigate Cr(VI) plume migration and exposure, particularly when tackling contaminant rebound post source remediation.


Subject(s)
Chromium , Groundwater , Oxidation-Reduction , Water Pollutants, Chemical , Groundwater/chemistry , Chromium/chemistry , Water Pollutants, Chemical/chemistry , Nanoparticles/chemistry , Environmental Restoration and Remediation/methods , Humic Substances , Ferrous Compounds/chemistry , Benzopyrans/chemistry
2.
Drug Alcohol Depend ; 251: 110941, 2023 10 01.
Article in English | MEDLINE | ID: mdl-37683451

ABSTRACT

BACKGROUND: Modern research suggests that the racial influence on smoking and drinking behaviors may not be as prevalent as once thought. This study utilizes national survey data to compare binge drinking and commercial cigarette smoking behaviors between American Indians/Alaskan Natives (AI/AN) and non-Hispanic Whites in the five most populous AI/AN U.S. states. METHODS: Data were analyzed from the Behavioral Risk Factor Surveillance System (BRFSS) from 2018 to 2022; White (n=79,405), AI/AN (n=11,007). Data analyses include frequency statistics, followed by two model evaluations comparing main effects of race/ethnicity and sex for both binge drinking and commercial cigarette smoking behaviors, and subgroup estimates of race/ethnicity by sex. An ANOVA was utilized to evaluate differences by race/ethnicity, sex, and race/ethnicity by sex subgroups by states. RESULTS: Males were over twice as likely to engage in binge drinking, with no significant differences found between people identifying as AI/AN and White individuals. Both White and AI/AN males were twice as likely to engage in binge drinking, compared to their White female counterparts. AI/AN individuals were over twice as likely to engage in commercial cigarette smoking compared to their White counterparts. CONCLUSIONS: Results showed no significance differences in AI/AN versus White individuals in binge drinking (controlling for sex, age, and income), while there were significant differences by sex (controlling for race/ethnicity, age, and income). People identifying as AI/AN were significantly more likely to engage in commercial cigarette smoking compared to White individuals, signifying the importance of racial/ethnical and covariate considerations when establishing public health interventions.


Subject(s)
American Indian or Alaska Native , Binge Drinking , Tobacco Use , Female , Humans , Male , United States/epidemiology , White
3.
Sci Adv ; 9(39): eadh5131, 2023 Sep 29.
Article in English | MEDLINE | ID: mdl-37756404

ABSTRACT

The staggering accumulation of end-of-life lithium-ion batteries (LIBs) and the growing scarcity of battery metal sources have triggered an urgent call for an effective recycling strategy. However, it is challenging to reclaim these metals with both high efficiency and low environmental footprint. We use here a pulsed dc flash Joule heating (FJH) strategy that heats the black mass, the combined anode and cathode, to >2100 kelvin within seconds, leading to ~1000-fold increase in subsequent leaching kinetics. There are high recovery yields of all the battery metals, regardless of their chemistries, using even diluted acids like 0.01 M HCl, thereby lessening the secondary waste stream. The ultrafast high temperature achieves thermal decomposition of the passivated solid electrolyte interphase and valence state reduction of the hard-to-dissolve metal compounds while mitigating diffusional loss of volatile metals. Life cycle analysis versus present recycling methods shows that FJH significantly reduces the environmental footprint of spent LIB processing while turning it into an economically attractive process.

4.
Am J Sports Med ; 51(1): 32-37, 2023 01.
Article in English | MEDLINE | ID: mdl-36453727

ABSTRACT

BACKGROUND: Tibial eminence fractures are bony avulsions of the anterior cruciate ligament from its insertion on the intercondylar eminence. Numerous anatomic factors have been associated with anterior cruciate ligament injuries, such as posterior tibial slope, but there are few studies evaluating the association with tibial eminence fracture. PURPOSE: To compare posterior tibial slope of pediatric patients with and without tibial eminence fractures. We hypothesized that a steeper posterior tibial slope would be associated with tibial eminence fracture. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Patients who underwent surgical treatment of tibial eminence fracture were retrospectively identified between January 2000 and July 2021. Adults aged >20 years and those without adequate imaging were excluded. Controls without gross ligamentous or osseous pathology were identified. Descriptive information and Meyers and McKeever classification were recorded. Posterior tibial slope measurements were obtained by 2 independent orthopaedic surgeons twice, with measurements separated by 3 weeks. Chi-square tests and independent-samples t tests were used to compare posterior tibial slope and patient characteristics. Inter- and intrareviewer variability was determined via the intraclass correlation coefficient. RESULTS: A total of 51 patients with tibial eminence fractures and 57 controls were included. By sex, tibial eminence fractures occurred among 34 male and 17 female patients with a mean age of 10.9 years. The posterior tibial slope among those with tibial eminence fractures (9.7°) was not significantly greater than that of controls (8.8°; P = .07). Male patients with a tibial eminence fracture had significantly steeper slopes compared with controls (10.0° vs 8.4°; P = .006); this difference was not observed between female patients and female controls. Patients with a slope ≥1 SD above the mean (12.0°) had 3.8 times greater odds (95% CI, 1.3-11.6; P = .017) of having a tibial eminence fracture. Male patients with a posterior tibial slope >12° had 5.8 times greater odds (95% CI, 1.1-29.1; P = .034) of having a tibial eminence fracture compared with male controls. CONCLUSION: Male patients undergoing surgical fixation of a tibial eminence fracture had an increased posterior tibial slope as compared with case-controls. Increased posterior tibial slope may be a risk factor for sustaining a tibial eminence fracture, although the clinical significance of this deserves further investigation.


Subject(s)
Anterior Cruciate Ligament Injuries , Knee Fractures , Tibial Fractures , Adult , Humans , Male , Child , Female , Cohort Studies , Retrospective Studies , Anterior Cruciate Ligament/surgery , Tibia/surgery , Anterior Cruciate Ligament Injuries/surgery , Tibial Fractures/diagnostic imaging , Tibial Fractures/surgery
5.
Water Res ; 225: 119166, 2022 Oct 15.
Article in English | MEDLINE | ID: mdl-36198211

ABSTRACT

Water desalination using membrane technology is one of the main technologies to resolve water pollution and scarcity issues. In the membrane treatment process, mineral scale deposition and fouling is a severe challenge that can lead to filtration efficiency decrease, permeate quality compromise, and even membrane damage. Multiple methods have been developed to resolve this problem, such as scale inhibitor addition, product recovery ratio adjustment, periodic membrane surface flushing. The performance of these methods largely depends on the ability to accurately predict the kinetics of mineral scale deposition and fouling with or without inhibitors. Gypsum is one of the most common and troublesome inorganic mineral scales in membrane systems, however, no mechanistic model is available to accurately predict the induction time of gypsum crystallization and inhibition. In this study, a new gypsum crystallization and inhibition model based on the classical nucleation theory and a Langmuir type adsorption isotherm has been developed. Through this model, it is believed that gypsum nucleation may gradually transit from homogeneous to heterogeneous nucleation when the gypsum saturation index (SI) decreases. Such transition is represented by a gradual decrease of surface tension at smaller SI values. This model assumes that the adsorption of inhibitors onto the gypsum nucleus can increase the nucleus superficial surface tension and prolong the induction time. Using the new model, this study accurately predicted the gypsum crystallization induction times with or without nine commonly used scale inhibitors over wide ranges of temperature (25-90 °C), SI (0.04-0.96), and background NaCl concentration (0-6 mol/L). The fitted affinity constants between scale inhibitors and gypsum show a good correlation with those between the same inhibitors and barite, indicating a similar inhibition mechanism via adsorption. Furthermore, by incorporating this model with the two-phase mineral deposition model our group developed previously, this study accurately predicts the gypsum deposition time on the membrane material surfaces reported in the literature. We believe that the model developed in this study can not only accurately predict the gypsum crystallization induction time with or without scale inhibitors, elucidate the gypsum crystallization and inhibition mechanisms, but also optimize the mineral scale control in the membrane filtration system.


Subject(s)
Calcium Sulfate , Sodium Chloride , Calcium Sulfate/chemistry , Barium Sulfate , Water/chemistry , Minerals
6.
JSES Int ; 6(5): 815-819, 2022 Sep.
Article in English | MEDLINE | ID: mdl-36081697

ABSTRACT

Background: Rotator cuff tear (RCT) chronicity is an important factor in considering treatment options and outcomes for surgical repair. Many factors may contribute to delayed treatment, including timely access to care due to insurance status. The purpose of this study was to evaluate the relationship between the magnitude of RCT on presentation and insurance status. We hypothesize that publicly insured patients will have a greater incidence of chronic RCTs and shoulder pathology on initial presentation. Methods: Retrospective chart review of patients undergoing RCT repair at an academic tertiary care institution from 2005 to 2019. Demographic data, including age, race, sex, and insurance carrier, were collected. Insurance carriers were categorized into public (Medicare and Medicaid) or private insurance coverage. Individual magnetic resonance imagings were then reviewed by a board-certified musculoskeletal radiologist for supraspinatus (SS), infraspinatus (IS), subscapularis, and biceps tendon tears, as well as acromioclavicular arthritis. In addition, rotator cuff atrophy was evaluated by the scapular ratio. Univariate analysis of variance and logistic regression analyses were used to compare demographics and rotator cuff pathology between those with Medicaid and Medicare, as well as between publicly and privately insured patients. Results: Of the 492 patients in this study, 192 had private insurance, and 300 had public insurance (Medicaid: 50 and Medicare: 250). Insurance status was not found to be associated with differences in RCTs between Medicare and Medicaid patients. Those with Medicaid or Medicare (public), presented more frequently with SS or IS atrophy (SS atrophy, P = .002; IS atrophy, P = .039) than those with private insurance. However, after adjusting for age, no significant differences in rotator cuff tendon tear or atrophy frequencies were found between insurance groups. Conclusions: Patients with private and public insurance tend to present with similar chronicity and magnitude of RCTs. Insurance status does not appear to influence timely access to surgical care for patients with RCTs at an academic medical center.

7.
JAMA Netw Open ; 5(8): e2227423, 2022 08 01.
Article in English | MEDLINE | ID: mdl-36036935

ABSTRACT

Importance: An automated, accurate method is needed for unbiased assessment quantifying accrual of joint space narrowing and erosions on radiographic images of the hands and wrists, and feet for clinical trials, monitoring of joint damage over time, assisting rheumatologists with treatment decisions. Such a method has the potential to be directly integrated into electronic health records. Objectives: To design and implement an international crowdsourcing competition to catalyze the development of machine learning methods to quantify radiographic damage in rheumatoid arthritis (RA). Design, Setting, and Participants: This diagnostic/prognostic study describes the Rheumatoid Arthritis 2-Dialogue for Reverse Engineering Assessment and Methods (RA2-DREAM Challenge), which used existing radiographic images and expert-curated Sharp-van der Heijde (SvH) scores from 2 clinical studies (674 radiographic sets from 562 patients) for training (367 sets), leaderboard (119 sets), and final evaluation (188 sets). Challenge participants were tasked with developing methods to automatically quantify overall damage (subchallenge 1), joint space narrowing (subchallenge 2), and erosions (subchallenge 3). The challenge was finished on June 30, 2020. Main Outcomes and Measures: Scores derived from submitted algorithms were compared with the expert-curated SvH scores, and a baseline model was created for benchmark comparison. Performances were ranked using weighted root mean square error (RMSE). The performance and reproductivity of each algorithm was assessed using Bayes factor from bootstrapped data, and further evaluated with a postchallenge independent validation data set. Results: The RA2-DREAM Challenge received a total of 173 submissions from 26 participants or teams in 7 countries for the leaderboard round, and 13 submissions were included in the final evaluation. The weighted RMSEs metric showed that the winning algorithms produced scores that were very close to the expert-curated SvH scores. Top teams included Team Shirin for subchallenge 1 (weighted RMSE, 0.44), HYL-YFG (Hongyang Li and Yuanfang Guan) subchallenge 2 (weighted RMSE, 0.38), and Gold Therapy for subchallenge 3 (weighted RMSE, 0.43). Bootstrapping/Bayes factor approach and the postchallenge independent validation confirmed the reproducibility and the estimation concordance indices between final evaluation and postchallenge independent validation data set were 0.71 for subchallenge 1, 0.78 for subchallenge 2, and 0.82 for subchallenge 3. Conclusions and Relevance: The RA2-DREAM Challenge resulted in the development of algorithms that provide feasible, quick, and accurate methods to quantify joint damage in RA. Ultimately, these methods could help research studies on RA joint damage and may be integrated into electronic health records to help clinicians serve patients better by providing timely, reliable, and quantitative information for making treatment decisions to prevent further damage.


Subject(s)
Arthritis, Rheumatoid , Crowdsourcing , Arthritis, Rheumatoid/diagnostic imaging , Arthritis, Rheumatoid/drug therapy , Bayes Theorem , Humans , Machine Learning , Reproducibility of Results
8.
Sci Adv ; 8(6): eabm3132, 2022 Feb 11.
Article in English | MEDLINE | ID: mdl-35138886

ABSTRACT

Rare earth elements (REEs) are critical materials in electronics and clean technologies. With the diminishing of easily accessible minerals for mining, the REE recovery from waste is an alternative toward a circular economy. Present methods for REE recovery suffer from lengthy purifications, low extractability, and high wastewater streams. Here, we report an ultrafast electrothermal process (~3000°C, ~1 s) based on flash Joule heating (FJH) for activating wastes to improve REE extractability. FJH thermally degrades or reduces the hard-to-dissolve REE species to components with high thermodynamic solubility, leading to ~2× increase in leachability and high recovery yields using diluted acid (e.g., 0.1 M HCl). The activation strategy is feasible for various wastes including coal fly ash, bauxite residue, and electronic waste. The rapid FJH process is energy-efficient with a low electrical energy consumption of 600 kWh ton-1. The potential for this route to be rapidly scaled is outlined.

9.
Curr Probl Diagn Radiol ; 51(2): 146-151, 2022.
Article in English | MEDLINE | ID: mdl-34844828

ABSTRACT

OBJECTIVE: Remote workstations were rapidly deployed in our academic radiology practice in late March 2020 in response to the COVID-19 pandemic. Although well-received by faculty, there were concerns for the impact on resident education. MATERIALS AND METHODS: Surveys of the radiology trainees and faculty were conducted online seven- and thirteen-months following workstation deployment as a part of a quality improvement project to assess the impact on radiology education and faculty wellness, as well as assess the desired trajectory of remote work in an academic setting. RESULTS: The majority of trainees (52%) reported the implementation had negatively impacted resident education, greatest among lower level residents (p < .001). This perception did not change despite interventions and perceived improvement in teleconferencing. Greater than 75% of radiologists with remote workstations reported improved wellness and lower stress levels compared to the onsite radiologists. The majority of all respondents voted to continue or expand remote work following the COVID-19 pandemic in both surveys. CONCLUSIONS: Onsite teaching is important for the education of residents, particularly for lower-level residents. However, the adoption of a hybrid model in an academic setting may prove beneficial for faculty wellness and recruitment of the next generation.


Subject(s)
COVID-19 , Internship and Residency , Radiology , Faculty , Faculty, Medical , Humans , Pandemics , Radiology/education , SARS-CoV-2 , Surveys and Questionnaires
10.
Foot Ankle Int ; 43(3): 343-352, 2022 Mar.
Article in English | MEDLINE | ID: mdl-34689579

ABSTRACT

BACKGROUND: This study evaluated the union rate of talar neck fractures with substantial bone defects treated acutely with autologous tibial bone graft during primary osteosynthesis. METHODS: A case series at a level 1 trauma center was performed to identify consecutive patients who underwent operative fixation of talar neck fracture with autograft (Current Procedural Terminology codes 28445 and 20902) between 2015 and 2018. "Substantial bone defect" was defined as a gap greater than 5 mm in the sagittal plane and greater than one-third of width of the talar neck in the coronal plane. Postoperative foot computed tomographic (CT) scans were obtained for all patients. Primary outcome was union, and secondary outcomes were malunion, avascular necrosis (AVN), post-traumatic arthritis (PTA), and patient-reported outcomes (PROs). RESULTS: Twelve patients with 12 fractures were included in the series, with an average length of follow-up of 26 months (range: 7-55) The average age was 34 years (17-59), and the most common mechanism of injury was motor vehicle crash. The Hawkins classification of the fractures was 4 type II (2 type IIA and 2 type IIB) (33%) and 8 type III (67%). Four fractures (33%) were open fractures. Union was achieved in 11 patients (92%). There was 1 malunion (8%). AVN was identified on postoperative CT scans in 11 patients (92%). Three of these 11 eventually showed collapse. Ten patients (83%) had radiographic evidence of some degree of ankle PTA, and 12 patients (100%) had radiographic evidence of some degree of subtalar PTA. Average Patient-Reported Outcomes Measurement Information System-Short Form score was 37 (32-45) and average Foot and Ankle Ability Measure activities of daily living and sports subscale scores were, respectively, 61 (31-87) and 31 (0-71), respectively. Average visual analog scale score was 5 (0-10), and average Foot Function Index was 49 (7-89). SF-36 scores showed fair to poor outcomes in the majority of patients. CONCLUSION: In this relatively small series, tibial autograft in primary osteosynthesis of comminuted talar neck fractures with substantial bone defects is associated with excellent union rates and low malunion rates. Despite high union rates, secondary outcomes of AVN with or without collapse, ankle and subtalar PTA, and relatively low PROs were common. LEVEL OF EVIDENCE: Level IV, case series.


Subject(s)
Fractures, Bone , Talus , Activities of Daily Living , Adult , Autografts , Fracture Fixation, Internal/methods , Fractures, Bone/complications , Fractures, Bone/diagnostic imaging , Fractures, Bone/surgery , Humans , Talus/injuries , Talus/surgery , Treatment Outcome
11.
Dev Comp Immunol ; 114: 103866, 2021 01.
Article in English | MEDLINE | ID: mdl-32937163

ABSTRACT

A candidate antimicrobial peptide (AmAMP1) was identified by searching the whole genome sequence of Acropora millepora for short (<125AA) cysteine-rich predicted proteins with an N-terminal signal peptide but lacking clear homologs in the SwissProt database. It resembled but was not closely related to damicornin, the only other known AMP from a coral, and was shown to be active against both Gram-negative and Gram-positive bacteria. These proteins define a family of AMPs present in corals and their close relatives, the Corallimorpharia, and are synthesised as preproproteins in which the C-terminal mature peptide contains a conserved arrangement of six cysteine residues. Consistent with the idea of a common origin for AMPs and toxins, this Cys motif is shared between the coral AMPs and the Shk neurotoxins of sea anemones. AmAMP1 is expressed at late stages of coral development, in ectodermal cells that resemble the "ganglion neurons" of Hydra, in which it has recently been demonstrated that a distinct AMP known as NDA-1 is expressed.


Subject(s)
Anthozoa/immunology , Antimicrobial Peptides/genetics , Cnidaria/immunology , Cnidarian Venoms/genetics , Ectoderm/metabolism , Sea Anemones/immunology , Animals , Antimicrobial Peptides/metabolism , Conserved Sequence , Cysteine/genetics , Phylogeny , Species Specificity , Structural Homology, Protein
12.
Spectrochim Acta A Mol Biomol Spectrosc ; 248: 119184, 2021 Mar 05.
Article in English | MEDLINE | ID: mdl-33293226

ABSTRACT

The CcCR quartic force field (QFF) methodology is capable of computing B0 and C0 rotational constants to within 35 MHz (0.14%) of experiment for triatomic and larger molecules with at least two heavy atoms. Additionally, the same constants for molecules with four or more atoms agree to within 20 MHz (0.12%) of experiment for the current test set. This work also supports previous claims that the same QFF methodology can produce fundamental vibrational frequencies with a deviation less than 5.7 cm-1 from experiment. Consequently, this approach of augmenting complete basis set extrapolated energies with treatments of core electron correlation and scalar relativity produces some of the most accurate rovibrational spectroscopic data available.

13.
Sci Rep ; 10(1): 19181, 2020 11 05.
Article in English | MEDLINE | ID: mdl-33154392

ABSTRACT

Heat stress in dairy cattle leads to reduction in feed intake and milk production as well as the induction of many physiological stress responses. The genes implicated in the response to heat stress in vivo are not well characterised. With the aim of identifying such genes, an experiment was conducted to perform differential gene expression in peripheral white blood cells and milk somatic cells in vivo in 6 Holstein Friesian cows in thermoneutral conditions and in 6 Holstein Friesian cows exposed to a short-term moderate heat challenge. RNA sequences from peripheral white blood cells and milk somatic cells were used to quantify full transcriptome gene expression. Genes commonly differentially expressed (DE) in both the peripheral white blood cells and in milk somatic cells were associated with the cellular stress response, apoptosis, oxidative stress and glucose metabolism. Genes DE in peripheral white blood cells of cows exposed to the heat challenge compared to the thermoneutral control were related to inflammation, lipid metabolism, carbohydrate metabolism and the cardiovascular system. Genes DE in milk somatic cells compared to the thermoneutral control were involved in the response to stress, thermoregulation and vasodilation. These findings provide new insights into the cellular adaptations induced during the response to short term moderate heat stress in dairy cattle and identify potential candidate genes (BDKRB1 and SNORA19) for future research.


Subject(s)
Gene Expression , Heat-Shock Response/genetics , Leukocytes/metabolism , Milk/cytology , Animals , Cattle , Female , Hot Temperature , Milk/metabolism , Transcriptome
14.
J Patient Rep Outcomes ; 4(1): 65, 2020 Aug 05.
Article in English | MEDLINE | ID: mdl-32757092

ABSTRACT

BACKGROUND: Approximately 7-10% of Parkinson's disease (PD) patients carry a GBA (Glucocerebrosidase) mutation (GBA-PD patients), which may influence the disease's clinical course. OBJECTIVES: This study aimed to explore the patient experience of GBA-PD and identify the most important symptoms and impacts to inform clinical trial measurement strategies. METHODS: Twenty PD patients (n = 15 GBA-PD; n = 5 idiopathic-PD) participated in qualitative interviews which explored concepts spontaneously reported or identified through a literature review. Telephone interviews with five expert clinicians included discussion of a preliminary conceptual model derived from literature. Verbatim transcripts were thematically analysed. RESULTS: Thirty symptoms reported by patients were categorized as motor, non-motor, and cognitive/psychiatric. Tremor (n = 13), memory loss (n = 13), rigidity/stiffness (n = 11), and speech problems (n = 11) were considered the most important and impactful symptoms by GBA-PD patients, although other symptoms were also relevant to the majority of patients. Key impacts included: sleep disturbances (n = 13), handwriting changes (n = 13), reduced social interaction (n = 12), dyskinesia (n = 10), depressed mood (n = 9), and fear of falling (n = 8). Key symptoms and impacts reported by GBA-PD patients were consistent with those reported by idiopathic-PD patients. Clinician interview results supported the patient findings, although some clinicians indicated that cognitive/psychiatric symptoms may present earlier in GBA-PD patients. The concepts emerging from the research informed updates to a conceptual model of GBA-PD patients' disease experience. CONCLUSIONS: The findings provide in-depth understanding of the patient experience of GBA-PD. The findings confirm that the concepts relevant to assess in GBA-PD are consistent with those relevant to assess in idiopathic-PD; however, greater consideration of cognitive/psychiatric symptoms may be warranted in GBA-PD populations.

15.
Environ Sci Pollut Res Int ; 27(2): 1449-1460, 2020 Jan.
Article in English | MEDLINE | ID: mdl-31748989

ABSTRACT

Desorption of hydrophobic organic contaminants (HOCs) from sedimentary materials plays a vital role in dictating the fate and transport of HOCs in the environment. Desorption irreversibility is a commonly observed phenomenon in laboratory sorption/desorption studies of HOCs. A desorption-resistant fraction (DRF) typically exists during the desorption process. To correctly evaluate the DRF of HOCs can considerably contribute to the understanding of availability and bioavailability of HOCs. This can substantially benefit contaminant remediation and cleanup operations. Conventional batch method to measure the DRF replies on repetitive washing of the sediments, which is time-consuming and can be impractical. This study presents an experimental protocol to quantify the DRF of the sediment-sorbed organic contaminants in a rapid manner. This protocol utilizes cosolvent to expedite desorption kinetics and adopts an ultrafiltration/centrifugation combined method to achieve a complete separation of sediment and solution phases. This proposed experimental protocol can facilitate the quantification of the DRF of sorbed contaminants to understand and minimize the uncertainties associated with risk-based pollution remediation approach. This protocol has the potential to be widely used in environmental studies to characterize sorption and desorption properties of HOCs with soil and sedimentary materials.


Subject(s)
Biological Availability , Geologic Sediments , Hydrophobic and Hydrophilic Interactions , Polycyclic Aromatic Hydrocarbons/metabolism , Soil Pollutants/metabolism , Adsorption , Soil
16.
Eur J Clin Microbiol Infect Dis ; 38(9): 1709-1717, 2019 Sep.
Article in English | MEDLINE | ID: mdl-31302785

ABSTRACT

To investigate long-term health sequelae of cryptosporidiosis, with especial reference to post-infectious irritable bowel syndrome (PI-IBS). A prospective cohort study was carried out. All patients with laboratory-confirmed, genotyped cryptosporidiosis in Wales, UK, aged between 6 months and 45 years of age, over a 2-year period were contacted. Five hundred and five patients agreed to participate and were asked to complete questionnaires (paper or online) at baseline, 3 and 12 months after diagnosis. The presence/absence of IBS was established using the Rome III criteria for different age groups. Two hundred and five of 505 cases completed questionnaires (40% response rate). At 12 months, over a third of cases reported persistent abdominal pain and diarrhoea, 28% reported joint pain and 26% reported fatigue. At both 3 and 12 months, the proportion reporting fatigue and abdominal pain after Cryptosporidium hominis infection was statistically significantly greater than after C. parvum. Overall, 10% of cases had sufficient symptoms to meet IBS diagnostic criteria. A further 27% met all criteria except 6 months' duration and another 23% had several features of IBS but did not fulfil strict Rome III criteria. There was no significant difference between C. parvum and C. hominis infection with regard to PI-IBS. Post-infectious gastrointestinal dysfunction and fatigue were commonly reported after cryptosporidiosis. Fatigue and abdominal pain were significantly more common after C. hominis compared to C. parvum infection. Around 10% of people had symptoms meriting a formal diagnosis of IBS following cryptosporidiosis. Using age-specific Rome III criteria, children as well as adults were shown to be affected.


Subject(s)
Cryptosporidiosis/complications , Cryptosporidiosis/diagnosis , Irritable Bowel Syndrome/parasitology , Abdominal Pain/etiology , Adolescent , Adult , Arthralgia/etiology , Child , Child, Preschool , Cryptosporidium/genetics , Diarrhea/parasitology , Fatigue/etiology , Female , Follow-Up Studies , Genotype , Humans , Infant , Male , Middle Aged , Prospective Studies , Surveys and Questionnaires , Young Adult
17.
Chemosphere ; 211: 1183-1192, 2018 Nov.
Article in English | MEDLINE | ID: mdl-30223334

ABSTRACT

Surfactants are important environmental chemicals due to their extensive domestic and industrial applications, such as subsurface organic pollution remediation and enhanced oil recovery. However, the interaction of surfactants with subsurface material particularly the desorption behavior of surfactants is less understood. Surfactant desorption is essential to control the fate and transport of surfactants as well as organic pollutants. In this study, the sorption and desorption of linear sodium dodecylbenzene sulfonate (SDBS) and sodium hexadecyl diphenyl oxide disulfonate (DPDS) with two types of soil sediment samples are compared. Sorption of surfactants can be modeled by hydrophobic sorption. Less DPDS sorption is observed at a higher aqueous concentration, which is attributed to the competition between surfactant micelles and sediment organic matter for DPDS sorption. A significant fraction of the sorbed surfactants resists desorption, and this is not a result of surfactant precipitation or desorption kinetics. Surfactant desorption behavior is similar to the irreversible desorption of hydrocarbons from soil with only half of the resistant phase surfactant being readily extracted by heated solvent extraction. The sorption/desorption data are interpreted with a molecular topology and irreversible sorption model. The knowledge of this study can be useful in understanding the environmental fate and transport of these common anionic surfactants. The methodology developed in this study can be expanded to study the sorptive nature of a wider range of surfactants in the environment.


Subject(s)
Adsorption , Soil/chemistry , Surface-Active Agents , Benzenesulfonates/pharmacology , Environmental Restoration and Remediation , Geologic Sediments , Micelles , Phenyl Ethers/pharmacology , Soil Pollutants/chemistry , Surface-Active Agents/chemistry , Surface-Active Agents/pharmacology
18.
Chemosphere ; 212: 50-55, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30138855

ABSTRACT

Ferric hydroxide precipitation and flocculation is the most commonly used method for the removal of arsenic in water treatment. However, citrate often interrupts the precipitation of ferric hydroxides and thus affects arsenic removal. To date, the mechanisms controlling the effects of citrate on arsenic removal with ferric hydroxide flocculation and precipitation at very low citrate-to-Fe molar ratios are not well understood. Herein, we report a new mechanism by which citrate inhibits arsenic removal using ferric hydroxide. At a substoichiometric citrate-to-Fe molar ratio of 0.28, citrate forms a high-molecular-weight Fe-citrate (Fe4Cit) species. The optimized structure of the Fe4Cit species was obtained by the density functional theory calculation. To the best of our knowledge, this study is the first to report the formation and to identify the structure of dominant Fe-citrate species at a very low citrate-to-Fe molar ratio.


Subject(s)
Arsenic/isolation & purification , Citric Acid/chemistry , Ferric Compounds/chemistry , Iron/chemistry , Water Pollutants, Chemical/isolation & purification , Water Purification/methods , Adsorption , Arsenic/analysis , Arsenic/chemistry , Flocculation , Molecular Weight , Water Pollutants, Chemical/analysis , Water Pollutants, Chemical/chemistry
19.
Epidemiol Infect ; 146(9): 1177-1183, 2018 07.
Article in English | MEDLINE | ID: mdl-29708089

ABSTRACT

Following a cluster of serious pseudomonas skin infections linked to a body piercing and tattooing premises, a look-back exercise was carried out to offer clients a screen for blood-borne viruses. Of those attending for screening 72% (581/809) had a piercing procedure in the premises of interest: 94 (16%) were under 16 years of age at the time of screening. The most common site of piercing was ear (34%), followed by nose (27%), nipple (21%) and navel (21%). A small number (<5) tested positive for hepatitis B and C, with no evidence this was linked to the premises. However, 36% (211/581) of clients reported a skin infection associated with their piercing. Using data from client forms, 36% provided a false age. Those aged under 16 years (OR 4.5, 95% CI 2.7-7.7) and those receiving a piercing at an intimate site (OR 2.1, 95% CI 1.3-3.6) were more likely to provide a false age. The findings from this exercise were used to support the drafting of the Public Health (Wales) Bill which proposed better regulation of piercing premises and the need to provide proof of being 18 years of age or over before having a piercing of an intimate site.


Subject(s)
Body Piercing/adverse effects , Hygiene/standards , Pseudomonas Infections/etiology , Pseudomonas aeruginosa , Public Health/standards , Skin Diseases, Bacterial/etiology , Adolescent , Adult , Age Factors , Female , Humans , Hygiene/legislation & jurisprudence , Incidence , Informed Consent , Male , Needs Assessment , Pseudomonas Infections/epidemiology , Pseudomonas Infections/prevention & control , Public Health/legislation & jurisprudence , Risk Assessment , Risk Factors , Skin Diseases, Bacterial/epidemiology , Skin Diseases, Bacterial/prevention & control , Tattooing/adverse effects , Wales/epidemiology , Young Adult
20.
Front Plant Sci ; 9: 61, 2018.
Article in English | MEDLINE | ID: mdl-29441087

ABSTRACT

Proper seed development requires coordinated growth among the three genetically distinct components, the embryo, the endosperm, and the seed coat. In Arabidopsis, embryo growth rate accelerates after endosperm cellularization, which requires a chromatin-remodeling complex, the FIS2-Polycomb Repressive Complex 2 (PRC2). After cellularization, the endosperm ceases to grow and is eventually absorbed by the embryo. This sequential growth pattern displayed by the endosperm and the embryo suggests a possibility that the supply of sugar might be shifted from the endosperm to the embryo upon endosperm cellularization. Since invertases and invertase inhibitors play an important role in sugar partition, we investigated their expression pattern during early stages of seed development in Arabidopsis. Two putative invertase inhibitors (InvINH1 and InvINH2) were identified as being preferentially expressed in the micropylar endosperm that surrounds the embryo. After endosperm cellularization, InvINH1 and InvINH2 were down-regulated in a FIS2-dependent manner. We hypothesized that FIS2-PRC2 complex either directly or indirectly represses InvINH1 and InvINH2 to increase invertase activity around the embryo, making more hexose available to support the accelerated embryo growth after endosperm cellularization. In support of our hypothesis, embryo growth was delayed in transgenic lines that ectopically expressed InvINH1 in the cellularized endosperm. Our data suggested a novel mechanism for the FIS2-PRC2 complex to control embryo growth rate via the regulation of invertase activity in the endosperm.

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