Using Google Trends and Google to investigate public information needs in relation to dementia and dementia medication

Introduction

Although dementia is a global public health concern, there remains a large variability in public awareness of the condition and associated medications (1,2). Google Trends, a publicly available online resource, acts as a useful tool in the analysis of internet search activity and population behaviour, with applications across field of healthcare. It has not been used to date to investigate information needs in relation to dementia and dementia medications.

Aim

To investigate public information needs regarding dementia and dementia medications, by evaluating data from Google Trends and Google.

Methods

Google Trends was queried using search terms relating to dementia and dementia medications, for the five-year period to January 2020 and the 12-month period to January 2020, for United Kingdom (UK) and Ireland domains. The “top related queries” for each search term were extracted and recorded, and thematic analysis undertaken. The top ten Google search results for each search term were recorded, and assigned a rank based on their page position, from 1 (first search result, highest rank) to 10 (lowest rank); count (the number of times the website domain appeared near the top of the search results) and average rank (i.e. ordinal position) were calculated for each domain. Google Trends was also queried using the term “dementia” for the UK domain, from 2004 to February 2020, and Loess Seasonal Trend Decomposition undertaken using R software to determine seasonality patterns in internet searching.

Results

Thematic analysis highlighted that the public sought information on dementia types, causes, signs and symptoms, diagnosis, prognosis, care and charitable organisations. Themes were broadly similar across time periods and UK/Ireland domains, with minor differences observed, including increased interest in research and development in 12-month UK data, and greater interest in charitable/government support in Ireland. The public sought information on acetylcholinesterase inhibitors and memantine, their indications, doses, formulations, side effects, antipsychotic use for agitation, information sources for dementia medications, and medications for co-morbidities. Analysis of search results, count and average rank revealed that the public were often directed to high-quality evidence-based websites for condition and medication-related search terms, though some less reliable information sources also featured. Seasonal variation was observed; a modest swing in interest was exhibited over the year, peaking in May (correlating with Dementia Action Week) and falling to its lowest level in August. Overall a steady increase in search interest for “dementia’” over time was observed.

Conclusion

The public sought basic information about these subjects, and were often, but not always, directed to high-quality evidence-based websites. Public awareness of, and interest in, dementia is increasing, and future public health campaigns should seek to build on the success of previous campaigns. The strength of this study lies in the use of Google Trends and Google to investigate information needs in relation to dementia and dementia medications; to the best of our knowledge, this is the first study to do so. Limitations must be considered; it can be difficult to draw absolute conclusions from Google Trends data alone, and results should be interpreted with caution.

References

1. Cahill S, Pierce M, Werner P, Darley A, Bobersky A. A systematic review of the public’s knowledge and understanding of Alzheimer’s disease and dementia. Alzheimer’s Disease & Associated Disorders. 2015; 29(3):255–75.

2. Cations M, Radisic G, Crotty M, Laver KE. What does the general public understand about prevention and treatment of dementia? A systematic review of population-based surveys. PLoS One. 2018; 13:1–18.

Subjective and objective social status: associations with psychosocial predictors and oral health

OBJECTIVE

While social status and health have been investigated, there is less focus on the effects of objective and subjective social status and psychosocial factors. This study aimed to investigate oral health impacts by subjective social status (SSS) and psychosocial predictors stratified by subjective social status.

METHODS

A random cross-sectional sample of 45-54-year old South Australians was surveyed in 2004-05. Oral health impact was assessed using OHIP-14. Socio-economic status was determined using objective (income) and subjective (McArthur scale) measures. Psychosocial variables comprised social support, health self-efficacy, coping and affectivity.

RESULTS

Responses were collected from 986 persons (response rate=44.4%). Lower SSS was more frequently observed in the low (70.2%) than high-income group (28.5%). Lower SSS was associated (p⟨0.05) with lower education, social support, health competence, and coping, but higher negative affect within income groups. The interaction of SSS and income showed OHIP was consistently lower at high SSS regardless of higher or lower income, but at low SSS, OHIP was higher (p⟨0.05) in the lower than higher income group.

CONCLUSIONS

SSS was associated with income. Their interaction indicated low SSS in combination with low income was associated with higher oral health impacts.

Temporomandibular dysfunction among working Australian adults and association with workplace effort-reward imbalance

OBJECTIVES

To explore the prevalence of temporomandibular dysfunction (TMD) among working Australian adults and examine whether workplace effort-reward imbalance is associated with TMD.

METHOD

Data were from Australia's National Survey of Adult Oral Health (NSAOH) 2004-06, a cross-sectional stratified clustered sample of Australian adults. The NSAOH data included information from a Computer Assisted Telephone Interview, self-complete questionnaire and oral epidemiological examination. Data included demographics, socio-economic characteristics, caries experience, diagnostic criteria for TMD, the Perceived Stress Scale (PSS) and a modified version of the Effort-Reward Imbalance instrument (ERI) where ERI ratio is the weighted ratio of workplace effort/reward subscales. Subpopulation analysis for working adults was conducted including complex sample descriptive statistics, bivariate and multivariable logistic regression models.

RESULTS

NSAOH had 4014 participants with 2329 (65.1%, SE=1.3%) working adults included in the subpopulation analysis. Among working adults, TMD prevalence was 9.4% (SE=1.0%), which was slightly less than population prevalence (PR=9.9%, SE=0.8%), and was higher for females (PR=12.4%, SE=1.4%), people aged ⟨35 years (PR=11.2%, SE=2.2%) and uninsured (PR=11.8%, SE=1.7%). TMD prevalence was associated with the ERI ratio (OR=2.5, 95% CI: 1.3-4.5) and PSS scores (OR=1.1, 95% CI: 1.0-1.09) in bi-variate associations. In multivariable logistic regression, TMD was associated with being female (OR=2.1, 95% CI:1.3-3.6), university qualified (OR=0.43, 95%CI: 0.21-0.88) and with the ERI ratio (OR=2.63, 95% CI: 1.47-4.72).

CONCLUSION

Greater effort-reward imbalance in the workplace is a psychosocial risk factor for TMD. This finding might need to be considered by clinicians managing TMD patients with need for investigating the efficacy of workplace stress management interventions.

Water Vapor Binding on Organic Matter-Coated Minerals

Atmospheric water vapor binding to soils is a key process driving water availability in unsaturated terrestrial environments. Using a representative hydrophilic iron oxyhydroxide, this study highlights key mechanisms through which water vapor (i) adsorbs and (ii) condenses at mineral surfaces coated with Leonardite humic acid (LHA). Microgravimetry and vibrational spectroscopy showed that liquid-like water forms in the three-dimensional array of mineral-bound LHA when present at total C/Fe ratios well exceeding ∼73 mg C per g Fe (26 C atoms/nm²). Below these loadings, minerals become even less hydrophilic than in the absence of LHA. This lowering in hydrophilicity is caused by the complexation of LHA water-binding sites to mineral surfaces, and possibly by conformational changes in LHA structure removing available condensation environments for water. An empirical relationship predicting the dependence of water adsorption densities on LHA loadings was developed from these results. Together with the molecular-level description provided in this work, this relationship should guide efforts in predicting water availability, and thereby occurrences of water-driven geochemical processes in terrestrial environments.

Remediation of oil-contaminated harbor sediments by chemical oxidation

Oil hydrocarbons are widespread pollutants in sub-surface sediments with serious threats to terrestrial and aquatic environment. However, very limited data is available about remediation of historically contaminated sediments. This study reports the use of magnetite-catalyzed chemical oxidation (H₂O₂ and Na₂S₂O₈) to degrade oil hydrocarbons in aged contaminated sediments. For this purpose, oil contaminated sediments were sampled from three different locations in France including two harbors and one petroleum industrial channel. These sediments were characterized by different hydrocarbon index (HI) values (3.7-9.0gkg^-1), total organic carbon contents (1.9%-8.4%) and textures (sand, slit loam and silt). Chemical oxidation was performed in batch system for one week at circumneutral pH by: H₂O₂ alone, H₂O₂/Fe(II), H₂O₂/magnetite, Na₂S₂O₈ alone, Na₂S₂O₈/Fe(II), and Na₂S₂O₈/magnetite. Results obtained by GC-FID indicated substantial hydrocarbon degradation (40-70%) by H₂O₂/magnetite and Na₂S₂O₈/magnetite. However, oxidants alone or with soluble Fe(II) caused small degradation (<5%). In the presence of H₂O₂/magnetite, degradation of extractable organic matter and that of HI were highly correlated. However, no such correlation was observed for Na₂S₂O₈/magnetite which resulted in higher removal of HI indicating its selective oxidation behavior. Treatment efficiency was negatively influenced by organic carbon and carbonate contents. For being the first study to report chemical oxidation of oil hydrocarbons in real contaminated sediments, it may have practical implications to design a remediation strategy for target contaminants.

Magnetite and Green Rust: Synthesis, Properties, and Environmental Applications of Mixed-Valent Iron Minerals

Mixed-valent iron [Fe(II)-Fe(III)] minerals such as magnetite and green rust have received a significant amount of attention over recent decades, especially in the environmental sciences. These mineral phases are intrinsic and essential parts of biogeochemical cycling of metals and organic carbon and play an important role regarding the mobility, toxicity, and redox transformation of organic and inorganic pollutants. The formation pathways, mineral properties, and applications of magnetite and green rust are currently active areas of research in geochemistry, environmental mineralogy, geomicrobiology, material sciences, environmental engineering, and environmental remediation. These aspects ultimately dictate the reactivity of magnetite and green rust in the environment, which has important consequences for the application of these mineral phases, for example in remediation strategies. In this review we discuss the properties, occurrence, formation by biotic as well as abiotic pathways, characterization techniques, and environmental applications of magnetite and green rust in the environment. The aim is to present a detailed overview of the key aspects related to these mineral phases which can be used as an important resource for researchers working in a diverse range of fields dealing with mixed-valent iron minerals.

Preferences for dental decisional control and associations with quality of life among third molar patients attending public dental services

OBJECTIVES

To explore (1) the prevalence of dental decisional control preferences (DDCP) among third molar (TM) patients attending public dental services and associated individual's characteristics, and (2) the association between DDCP and quality of life (QoL).

METHOD

Participants were adult public dental patients with internet access referred for TM consultation. Collected data included patients' socio-demographic variables, the Control Preferences Scale (CPS), the Oral Health Impact Profile (OHIP-14) and the EuroQol EQ-5D-5L.

RESULTS

Participants (n=163) were mainly females (73.6%) with a mean age of 26.2 years (SD=8.3). Most participants preferred an active DDCP (n=71, 44.1%) or a collaborative DDCP (n=60, 37.3%) while a minority preferred a passive DDCP (n=30, 18.6%). Gender (P=.05) and education (P=.03) were associated with DDCP. In a multinomial logistic regression model for DDCP, females were more likely to have an active DDCP (OR=2.73, P=.04) as were participants who had tertiary education (OR=2.72, P=.04). In a linear regression model for OHIP-14, active (P=.05) and collaborative DDCP (P=.04) were associated with less impact on oral health-related QoL.

CONCLUSION

Patients attending public dental services preferred to be involved (either actively or collaboratively) in dental treatment decision-making. Being a female and/or having tertiary education were associated with an active DDCP. The positive association between patients' involvement in decision-making and oral health-related QoL might support the benefit for enhancing patients' involvement in decision-making.

Internet use, online information seeking and knowledge among third molar patients attending public dental services

BACKGROUND

While Australians are searching the internet for third molar (TM) information, the usefulness of online sources may be questioned due to quality variation. This study explored: (i) internet use, online information-seeking behaviour among TM patients attending public dental services; and (ii) whether patients' TM knowledge scores are associated with the level of internet use and eHealth Literacy Scale (eHEALS) scores.

METHODS

Baseline survey data from the 'Engaging Patients in Decision-Making' study were used. Variables included: sociodemographics, internet access status, online information-seeking behaviour, eHEALS, the Control Preferences Scale (CPS) and TM knowledge.

RESULTS

Participants (N = 165) were mainly female (73.8%), aged 19-25 years (42.4%) and had 'secondary school or less' education (58.4%). A majority (N = 79, 52.7%) had sought online dental information which was associated with active decisional control preference (odds ratio = 3.1, P = 0.034) and higher educational attainment (odds ratio = 2.7, P = 0.040). TM knowledge scores were not associated with either the level of internet use (F_(2,152) = 2.1, P = 0.094, χ² = 0.0310) or the eHEALS scores (r = 0.147, P = 0.335).

CONCLUSIONS

'The internet-prepared patient' phenomena exists among public TM patients and was explained by preference for involvement in decision-making. However, internet use was not associated with better TM knowledge. Providing TM patients with internet guidance may be an opportunity to improve TM knowledge.

Fenton oxidation to remediate PAHs in contaminated soils: A critical review of major limitations and counter-strategies

Fenton oxidation constitutes a viable remediation strategy to remove polycyclic aromatic hydrocarbons (PAHs) in contaminated soils. This review is intended to illustrate major limitations associated with this process like acidification, PAH unavailability, and deterioration of soil quality along with associated factors, followed by a critical description of various developments to overcome these constraints. Considering the limitation that its optimal pH is around 3, traditional Fenton treatment could be costly, impractical in soil due to the high buffering capacity of soils and associated hazardous effects. Use of various chelating agents (organic or inorganic) allowed oxidation at circumneutral pH but factors like higher oxidant demand, cost and toxicity should be considered. Another alternative is the use of iron minerals that can catalyze Fenton-like oxidation over a wide range of pH, but mobility of these particles in soils (i.e. saturated and unsaturated zones) should be investigated prior to in-situ applications. The PAH-unavailability is the crucial limitation hindering their effective degradation. Research data is compiled describing various strategies to address this issue like the use of availability enhancement agents, extraction or thermal pretreatment. Last section of this review is devoted to describe the effects of various developments in Fenton treatment onto soil quality and native microbiota. Finally, research gaps are discussed to suggest future directions in context of applying Fenton oxidation to remediate contaminated soils.

Removal of PCBs in contaminated soils by means of chemical reduction and advanced oxidation processes

Although the chemical reduction and advanced oxidation processes have been widely used individually, very few studies have assessed the combined reduction/oxidation approach for soil remediation. In the present study, experiments were performed in spiked sand and historically contaminated soil by using four synthetic nanoparticles (Fe(0), Fe/Ni, Fe3O4, Fe3 - x Ni x O4). These nanoparticles were tested firstly for reductive transformation of polychlorinated biphenyls (PCBs) and then employed as catalysts to promote chemical oxidation reactions (H2O2 or persulfate). Obtained results indicated that bimetallic nanoparticles Fe/Ni showed the highest efficiency in reduction of PCB28 and PCB118 in spiked sand (97 and 79 %, respectively), whereas magnetite (Fe3O4) exhibited a high catalytic stability during the combined reduction/oxidation approach. In chemical oxidation, persulfate showed higher PCB degradation extent than hydrogen peroxide. As expected, the degradation efficiency was found to be limited in historically contaminated soil, where only Fe(0) and Fe/Ni particles exhibited reductive capability towards PCBs (13 and 18 %). In oxidation step, the highest degradation extents were obtained in presence of Fe(0) and Fe/Ni (18-19 %). The increase in particle and oxidant doses improved the efficiency of treatment, but overall degradation extents did not exceed 30 %, suggesting that only a small part of PCBs in soil was available for reaction with catalyst and/or oxidant. The use of organic solvent or cyclodextrin to improve the PCB availability in soil did not enhance degradation efficiency, underscoring the strong impact of soil matrix. Moreover, a better PCB degradation was observed in sand spiked with extractable organic matter separated from contaminated soil. In contrast to fractions with higher particle size (250-500 and <500 μm), no PCB degradation was observed in the finest fraction (≤250 μm) having higher organic matter content. These findings may have important practical implications to promote successively reduction and oxidation reactions in soils and understand the impact of soil properties on remediation performance.

Effect of thermal pre-treatment on the availability of PAHs for successive chemical oxidation in contaminated soils

This is the premier study designed to evaluate the impact of thermal pre-treatment on the availability of polycyclic aromatic hydrocarbons (PAHs) for successive removal by chemical oxidation. Experiments were conducted in two soils having different PAH distribution originating from former coking plant sites (Homécourt, H, and Neuves Maisons, NM) located in northeast of France. Soil samples were pre-heated at 60, 100, and 150 °C for 1 week under inert atmosphere (N2). Pre-heating resulted in slight removal of PAHs (<10%) and loss of extractable organic matter (EOM). Then, these pre-heated soil samples were subjected to Fenton-like oxidation (H2O2 and magnetite) at room temperature. Chemical oxidation in soil without any pre-treatment showed almost no PAH degradation underscoring the unavailability of PAHs. However, chemical oxidation in pre-heated soils showed significant PAH degradation (19, 29, and 43% in NM soil and 31, 36, and 47% in H soil pre-treated at 60, 100, and 150 °C, respectively). No preferential removal of PAHs was observed after chemical oxidation in both soils. These results indicated the significant impact of pre-heating temperature on the availability of PAHs in contaminated soils and therefore may have strong implications in the remediation of contaminated soils especially where pollutant availability is a limiting factor.

Pseudo-first-order reaction of chemically and biologically formed green rusts with HgII and C₁₅H₁₅N₃O₂: effects of pH and stabilizing agents (phosphate, silicate, polyacrylic acid, and bacterial cells)

The kinetics of Hg(II) and methyl red (MR) reduction by hydroxycarbonate green rust (GR1) and by hydroxysulfate green rust (GR2) were studied in the presence of naturally occurring organic and inorganic ligands (phosphate, polyacrylic acid, bacterial cells, silicate). The reducing ability of biogenic hydroxycarbonate green rust (GR1bio), obtained after microbial reduction of lepidocrocite by Shewanella putrefaciens, was also investigated and compared to those of chemically synthesized GR1 and GR2 (GR1ab and GR2ab). Pseudo first-order rate constants (kobs) of Hg(II) reduction (at pH 7.0, 8.2, and 9.5) and MR reduction (at pH 7.0) were determined and were normalized to the structural Fe(II) content of GRs (kFeII) and to the estimated concentration of surface Fe(II) sites (kS). The kS values ranged from 0.3 L mmol(-1) min(-1) to 43 L mmol(-1) min(-1) for the Hg reduction, and from 0.007 L mmol(-1) min(-1) to 3.4 L mmol(-1) min(-1) for the MR reduction. No significant discrepancy between GRab and GRbio was observed in term of reactivity. However, the reduction kinetics of MR was generally slower than the Hg(II) reduction kinetics for all tested GRs. While a slight difference in Hg(II) reduction rate was noted whatever the pH values (7.0, 8.2, or 9.5), the reduction of MR was significantly affected in the presence of ligands. A decrease by a factor of 2-200, depending on the type of ligand used, was observed. These data give new insights into the reactivity of GRs in the presence of co-occurring organic and inorganic ligands, and have major implications in the characterization of contaminated systems as well as water treatment processes.

Sorption of phthalic acid at goethite surfaces under flow-through conditions

The objectives of this investigation were to improve our understanding of organic acid transport in porous media by focusing on a model system involving phthalic acid and goethite-coated sand (GCS). This was specifically made by first recalibrating a molecularly sound phthalate surface complexation model to GCS and then applying this model to describe breakthrough curves (BTC) in a GCS packed column. ATR-FTIR spectra of phthalic acid adsorbed at goethite surfaces at pH 3.0 and 6.0 and at loadings from 2.0 to 40.8 μmol/m(2) confirmed the coexistence of metal-bonded (MB) and hydrogen-bonded (HB) complexes at low pH and the predominance of HB complexes at high pH. This concept was incorporated into a surface complexation model used to describe BTC at influent pH (pH(in)) values of 3.0, 6.0, and 7.8. The BTC revealed strongly pH-dependent behaviors. At pH(in) 3.0, the BTC revealed one front/plateau behavior while at pH(in) 6.0 two fronts/plateaus occurred. The existence of a second front/plateau led to an overestimation of the sorbed amount compared to that observed in the batch and caused a failure in the prediction of BTC. Additional column investigations suggested that surface loadings of nonspecifically adsorbed complexes could vary with pH and ionic strength and that the two-step breakthrough behavior may have emerged as a result of the formation of surface species of different natures than those during the first step, with the latter even serving as attachment sites corresponding to the second step. These findings call for refinements in current day modeling approaches used in reactive transport studies.

Serum 25-hydroxy vitamin D concentrations are more deficient/insufficient in peritoneal dialysis than haemodialysis patients in a sunny climate

BACKGROUND

Research has identified associations between serum 25(OH)D and a range of clinical outcomes in chronic kidney disease and wider populations. The present study aimed to investigate vitamin D deficiency/insufficiency in dialysis patients and the relationship with vitamin D intake and sun exposure.

METHODS

A cross-sectional study was used. Participants included 30 peritoneal dialysis (PD) (43.3% male; 56.87 ± 16.16 years) and 26 haemodialysis (HD) (80.8% male; 63.58 ± 15.09 years) patients attending a department of renal medicine. Explanatory variables were usual vitamin D intake from diet/supplements (IU day(-1) ) and sun exposure (min day(-1) ). Vitamin D intake, sun exposure and ethnic background were assessed by questionnaire. Weight, malnutrition status and routine biochemistry were also assessed. Data were collected during usual department visits. The main outcome measure was serum 25(OH)D (nm).

RESULTS

Prevalence of inadequate/insufficient vitamin D intake differed between dialysis modality, with 31% and 43% found to be insufficient (<50 nm) and 4% and 33% found to be deficient (<25 nm) in HD and PD patients, respectively (P < 0.001). In HD patients, there was a correlation between diet and supplemental vitamin D intake and 25(OH)D (ρ = 0.84, P < 0.001) and average sun exposure and 25(OH)D (ρ = 0.50, P < 0.02). There were no associations in PD patients. The results remained significant for vitamin D intake after multiple regression, adjusting for age, gender and sun exposure.

CONCLUSIONS

The results highlight a strong association between vitamin D intake and 25(OH)D in HD but not PD patients, with implications for replacement recommendations. The findings indicate that, even in a sunny climate, many dialysis patients are vitamin D deficient, highlighting the need for exploration of determinants and consequences.

Chemical oxidation of hexachlorocyclohexanes (HCHs) in contaminated soils

Chemical oxidation of hexachlorocyclohexanes (HCHs) was evaluated in (i) artificially spiked sand with HCH isomers (α, β, γ and δ) and (ii) contaminated soil sampled from a former gravel pit backfilled with wastes of lindane (γ-HCH). Following oxidation treatments were employed: hydrogen peroxide alone (HP), hydrogen peroxide with soluble Fe(II) (Fenton-F), sodium persulfate alone (PS), Fe(II) activated persulfate (AP) and permanganate (PM). GC-MS results revealed a significant degradation of all isomers in spiked soil in the order: F>PS>AP>HP>PM. Soluble Fe(II) enhanced the efficiency of H2O2 but decreased the reactivity of persulfate. Similar trend was observed in contaminated soil, but with less degradation probably caused by scavenging effect of organic matter and soil minerals and/or pollutant unavailability. No significant increase in oxidation efficiency was observed after using availability-enhancement agents in contaminated soil. Other limitation factors (oxidant dose, pH, catalyst type etc.) were also addressed. Among all the isomers tested, β-HCH was the most recalcitrant one which could be explained by higher metabolic and chemical stability. No by-products were observed by GC-MS regardless of the oxidant used. For being the premier study reporting chemical oxidation of HCH isomers in contaminated soils, it will serve as a base for in-situ treatments of sites contaminated by HCH isomers and other persistent organic pollutants.

Treatment of hydrocarbon contamination under flow through conditions by using magnetite catalyzed chemical oxidation

Soil pollution by hydrocarbons (aromatic and aliphatic hydrocarbons) is a major environmental issue. Various treatments have been used to remove them from contaminated soils. In our previous studies, the ability of magnetite has been successfully explored to catalyze chemical oxidation for hydrocarbon remediation in batch slurry system. In the present laboratory study, column experiments were performed to evaluate the efficiency of magnetite catalyzed Fenton-like (FL) and activated persulfate (AP) oxidation for hydrocarbon degradation. Flow-through column experiments are intended to provide a better representation of field conditions. Organic extracts isolated from three different soils (an oil-contaminated soil from petrochemical industrial site and two soils polluted by polycyclic aromatic hydrocarbon (PAH) originating from coking plant sites) were spiked on sand. After solvent evaporation, spiked sand was packed in column and was subjected to oxidation using magnetite as catalyst. Oxidant solution was injected at a flow rate of 0.1 mL min(-1) under water-saturated conditions. Organic analyses were performed by GC-mass spectrometry, GC-flame ionization detector, and micro-Fourier transform infrared spectroscopy. Significant abatement of both types of hydrocarbons (60-70 %) was achieved after chemical oxidation (FL and AP) of organic extracts. No significant by-products were formed during oxidation experiment, underscoring the complete degradation of hydrocarbons. No selective degradation was observed for FL with almost similar efficiency towards all hydrocarbons. However, AP showed less reactivity towards higher molecular weight PAHs and aromatic oxygenated compounds. Results of this study demonstrated that magnetite-catalyzed chemical oxidation can effectively degrade both aromatic and aliphatic hydrocarbons (enhanced available contaminants) under flow-through conditions.

Transport of two naphthoic acids and salicylic acid in soil: experimental study and empirical modeling

In contrast to the parent compounds, the mechanisms responsible for the transport of natural metabolites of polycyclic aromatic hydrocarbons (PAH) in contaminated soils have been scarcely investigated. In this study, the sorption of three aromatic acids (1-naphthoic acid (NA), 1-hydroxy-2-naphthoic acid (HNA) and salicylic acid (SA)) was examined on soil, in a batch equilibrium single-system, with varying pH and acid concentrations. Continuous flow experiments were also carried out under steady-state water flow. The adsorption behavior of naphthoic and benzoic acids was affected by ligand functionality and molecular structure. All modeling options (equilibrium, chemical nonequilibrium, i.e. chemical kinetics, physical nonequilibrium, i.e. surface sites in the immobile water fraction, and both chemical and physical nonequilibrium) were tested in order to describe the breakthrough behavior of organic compounds in homogeneously packed soil columns. Tracer experiments showed a small fractionation of flow into mobile and immobile compartments, and the related hydrodynamic parameters were used for the modeling of reactive transport. In all cases, the isotherm parameters obtained from column tests differed from those derived from the batch experiments. The best accurate modeling was obtained considering nonequilibrium for the three organic compounds. Both chemical and physical nonequilibrium led to appropriate modeling for HNA and NA, while chemical nonequilibrium was the sole option for SA. SA sorption occurs mainly in mobile water and results from the concomitancy of instantaneous and kinetically limited sites. For all organic compounds, retention is contact condition dependent and differs between batch and column experiments. Such results show that preponderant mechanisms are solute dependent and kinetically limited, which has important implications for the fate and transport of carboxylated aromatic compounds in contaminated soils.

Chemical oxidation of ibuprofen in the presence of iron species at near neutral pH

The objective of this work was to evaluate the removal of ibuprofen (IBP) using the oxidants hydrogen peroxide (H(2)O(2)) and sodium persulfate (Na(2)S(2)O(8)). The ability of magnetite (Fe(3)O(4)) to activate persulfate (PS) and H(2)O(2) for the oxidation of IBP at near neutral pH was evaluated as well. The use of soluble Fe(2+) to activate H(2)O(2) and Na(2)S(2)O(8) was also investigated. H(2)O(2) and Na(2)S(2)O(8) were inactive during the sixty-minute experiments when used alone. However, activation using Fe(2+) increased the removal to 95% in the presence of H(2)O(2) (Fenton reaction) and 63% in the presence of Na(2)S(2)O(8) at pH 6.6. Chemical oxygen demand (COD) removal was also greater for Fenton oxidation (65%) than for iron-activated PS oxidation (25%). Activation of H(2)O(2) and PS by Fe(3)O(4) was only observed at a high oxidant concentration and over 48 h of reaction time. A second order rate kinetic constant was determined for H(2)O(2) (3.0∗10(-3) M(-1) s(-1)) and Na(2)S(2)O(8) (1.59∗10(-3) M(-1) s(-1)) in the presence of Fe(3)O(4). Finally, several of the degradation products formed during oxidation of IBP in the presence of H(2)O(2) and Na(2)S(2)O(8) (activated by Fe(2+)) were identified. These include oxalic acid, pyruvic acid, formic acid, acetic acid, 4-acetylbenzoic acid, 4-isobutylacetophenone (4-IBAP) and oxo-ibuprofen.

Safety of catheter-delivered plasmin in patients with acute lower extremity arterial or bypass graft occlusion: phase I results

BACKGROUND

Current treatment of acute peripheral artery or bypass graft occlusion utilizes catheter-directed thrombolysis of a plasminogen activator (PA). Plasmin is a direct-acting thrombolytic with a striking safety advantage over PA in preclinical models.

OBJECTIVES

To report the first use of purified plasmin for acute lower extremity arterial or bypass graft thrombosis in a phase I dose-escalation study of a catheter-delivered agent.

METHODS

Eighty-three patients with non-embolic occlusion of infrainguinal native arteries or bypass grafts were enrolled (safety population) into seven sequential dose cohorts to receive 25-175 mg of plasmin by intrathrombus infusion over 5 h. Arteriograms were performed at baseline, 2 h, and 5 h, and subjects were monitored for 30 days for clinical outcomes and laboratory parameters of systemic fibrinolysis.

RESULTS

Major bleeding occurred in four patients (4.8%), and minor bleeding alone in 13 (15.7%), with no trend towards more bleeding at higher dosages of plasmin. There was a trend towards lower plasma concentrations of fibrinogen, α(2) -antiplasmin and α(2) -macroglobulin with increasing doses of plasmin, but the nadir fibrinogen concentration was > 350 mg dL(-1) at the highest plasmin dose. Individual nadir values were above 200 mg dL(-1) in 82 of 83 subjects, and were not different in patients with or without bleeding. Thrombolysis (≥ 50%) occurred in 79% of subjects receiving 125-175 mg of plasmin, as compared with 50% who received 25-100 mg.

CONCLUSIONS

Catheter-delivered plasmin can be safely administered to patients with acute lower extremity arterial occlusion at dosages of 25-175 mg.

Application of magnetite-activated persulfate oxidation for the degradation of PAHs in contaminated soils

In this study, feasibility of magnetite-activated persulfate oxidation (AP) was evaluated for the degradation of polycyclic aromatic hydrocarbons (PAHs) in batch slurry system. Persulfate oxidation activated with soluble Fe(II) (FP) or without activation (SP) was also tested. Kinetic oxidation of PAHs was tracked in spiked sand and in aged PAH contaminated soils at circumneutral pH. Quartz sand was spiked with: (i) single model pollutant (fluorenone) and (ii) organic extract isolated from two PAH contaminated soils (H and NM sampled from ancient coking plants) and was subjected to oxidation. Oxidation was also performed on real H and NM soils with and without an extraction pretreatment. Results indicate that oxidation of fluorenone resulted in its complete degradation by AP while abatement was very low (<20%) by SP or FP. In soil extracts spiked on sand, significant degradation of 16 PAHs was observed by AP (70-80%) in 1 week as compared to only 15% by SP or FP systems. But no PAH abatement was observed in real soils whatever the treatment used (AP, FP or SP). Then soils were subjected to an extraction pretreatment but without isolation of organic extract from soil. Oxidation of this pretreated soil showed significant abatement of PAHs by AP. On the other hand, very low degradation was achieved by FP or SP. Selective degradation of PAHs was observed by AP with lower degradation efficiency towards high molecular weight PAHs. Analyses revealed that no by-products were formed during oxidation. The results of this study demonstrate that magnetite can activate persulfate at circumneutral pH for an effective degradation of PAHs in soils. However, availability of PAHs and soil matrix were found to be the most critical factors for degradation efficiency.

Mobility of Cd and Cu in formulated sediments coated with iron hydroxides and/or humic acids: a DGT and DGT-PROFS modeling approach

The diffusive gradients technique in thin films (DGT) was used to investigate the kinetic resupply of Cd and Cu to pore water from the solid phase. For the sake of simplification, experiments were performed using formulated sediments that differed in the presence or absence of humic acids (HA) and/or of iron hydroxides (i.e., goethite and ferrihydrite). The effects of the time after the contamination of the solid phase (aging effect) on formulated sediments that were coated with goethite and HA and spiked with Cd were also evaluated. Kinetic DGT results were interpreted using the newly developed, multi-compartmental model DGT-PROFS. Due to Cu humate formation, the addition of HA slightly increased the Cu concentration in the pore water independent of the effect of the iron hydroxide coating on the formulated sediments and slightly decreased that of Cd. The impact of 8-190d of aging resulted in a significant decrease in the Cd concentration of the pore water over an increasing incubation time. Modeling our results with DGT-PROFS led to the following conclusions concerning the impact of HA and iron hydroxides on Cd and Cu availability. First, in the presence of HA and absence of iron hydroxides, Cd is associated mainly with weak sites, while Cu is bound to strong sites. Similarly, in the presence of both iron hydroxides and HA, Cu appeared to be more heavily associated with the strong sites than did Cd. When the incubation time increased from 8 to 190d, a proportion of Cd initially adsorbed onto weak sites transferred to the strong sites, suggesting that the adsorption of Cd on sediments is controlled partially by slow kinetic processes.

Surface complexation of 2,5-dihydroxybenzoic acid (gentisic acid) at the nanosized hematite-water interface: an ATR-FTIR study and modeling approach

In this study, characteristic interactions of 2,5-dihydroxybenzoic acid (or gentisic acid, GA) with the surface of 15-nm-sized hematite (α-Fe2O3) were studied by combining batch macroscopic experiments, in situ attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopic investigations, and surface complexation modeling. A correlation between the pH, the amount of adsorbed GA, and the amount of Fe(III) released from the hematite surface was observed, whereas the dissolution of hematite nanoparticles became significant only at low pH and high ligand loading. From the ATR-FTIR results, two aqueous complex structures have been identified depending on pH. At the hematite-water interface, the occurrence of one deprotonated inner-sphere "bidentate" complex and one outer-sphere complex was suggested through all of the investigated pH range. At high surface coverage, variations of vibrational band intensities were observed, suggesting the occurrence of nonspecific molecular interactions. The macroscopic results (i.e., GA batch sorption and the ligand-promoted dissolution of hematite) obtained under a wide range of experimental conditions corroborated the ATR-FTIR microscopic findings. GA adsorption was described by a surface complexation model fitted to pH-adsorption curves with 1 mM sorbate concentration in the pH range of 3-9. Two surface complexes (one outer-sphere species (≡FeOH2)2···H2L((1+,1-)) and one inner-sphere species (≡Fe)2H2L) were proposed using the three-plane model. The inner-sphere complexes were predominant at low pH values, and the relative concentrations of the outer-sphere species increased with the pH increase. The formation of inner-sphere complexes at acidic pH values can promote the dissolution of nanosized hematite. At high solute loading, GA oxidation into carboxybenzoquinone compounds by ferric species was suspected, suggesting the occurrence of a redox reaction analogous to that of hydroquinone compounds.

Sorption of two naphthoic acids to goethite surface under flow through conditions

While the transport of low molecular weight organic acids was widely investigated, little is known about the mobility of the carboxylated aromatic compounds containing double rings in natural porous media. This study combines macroscopic (batch and column), microscopic (vibration spectroscopy), and surface complexation modeling to evaluate the mobility of two PAH degradation products: naphthoic acid (1-naphthoic acid (NA) and 1-hydroxy-2-naphthoic acid (HNA)), in porous media consisting of goethite-coated sand. The loss of ligands from aqueous solution was attributed to (1) a hydrogen-bonded surface complex present over the entire 3-10 pH range as well as protonated (2) surface and (3) bulk precipitates below pH 5. Mobility in column experiments was strongly affected by ligand functionality. Adsorption breakthrough predictions that make use of surface complexation parameters accurately predicted NA mobility. Those for HNA however predicted much less adsorption reactions than in the batch sorption experiments. Additional breakthrough experiments and test calculations confirmed that these differences were not related to sorption kinetics. HNA adsorption breakthrough data could only be predicted by lowering intrinsic complexation constant of the formation of hydrogen-bonded species, thereby suggesting modifications of the diffuse layer properties under flow conditions. These findings have strong implications in the assessment and prediction of contaminant transport and environmental remediation.

Confirming the efficacy of intravenous immunoglobulin in CIDP through minimum clinically important differences: shifting from statistical significance to clinical relevance

BACKGROUND

The ICE trial demonstrated the efficacy of immune globulin intravenous (IGIV-C) over placebo in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). However, improving the interpretability of the results by analysing the minimum clinically important difference (MCID) had not been considered.

OBJECTIVES

To identify MCID thresholds of various outcome measures using different methods and to test treatment differences (IGIV-C vs placebo) using these thresholds.

METHODS

One anchor-based (Short Form-36 question 2) and three distribution-based (½ SD, 1 SE of measurement, and effect size) techniques were employed to identify MCID cut-offs for various impairments (electromyographic parameters, Medical Research Council (MRC) sum score, grip strength, inflammatory neuropathy cause and treatment (INCAT) sensory sum score), disability (INCAT scale score, Rotterdam handicap scale (RHS) score) and quality of life (SF-36). IGIV-C or placebo was administered every 3 weeks for up to 24 weeks to 117 CIDP patients. Patients who did not improve by ≥1 point on the INCAT scale received alternate treatment. The proportion of patients with results exceeding identified MCID thresholds was compared. Results MCID cut-offs for outcomes were determined using each method. For the INCAT disability scale (primary ICE-trial outcome), all MCID methods identified significantly more responders with IGIV-C than placebo. Significant differences favouring IGIV-C were also demonstrated for various nerve conduction parameters, MRC sum score, grip strength, RHS score and SF-36 physical component summary score.

CONCLUSION

In addition to being statistically significant, all MCID analyses showed that CIDP improvements with IGIV-C are clinically meaningful. Consideration of MCID is recommended in future therapeutic trials. Trial Registration Number NCT00220740 (http://ClinicalTrials.gov).

Sorption and transport of salicylate in a porous heterogeneous medium of silica quartz and goethite

Among transport studies of solutes in porous media, few works have combined microscopic speciation with macroscopic-scale investigations to describe the impact of antecedent sorbed silica on the transport of organic ligands in porous heterogeneous media. In this study, the sorption of salicylate (SA) to goethite-coated sand (GCS) was investigated under static and dynamic conditions by combining batch experiments and column tests with infrared spectroscopy. On the basis of infrared spectra, the salicylate adsorption was described by one type of iron site and a mononuclear bidentate surface complex. The intrinsic complexation constant deduced from batch modeling was successfully applied to estimate the sorbed amount under flow through conditions at various water velocities (0.038-0.768 cm/min). The shape of the breakthrough curve of SA was characterized by two fronts in both SA concentration and pH. This behavior could be likely explained by the mobilization of initially adsorbed silica from goethite surface upon SA sorption. The SA breakthrough can be interpreted as retention of SA on available surface sites up to their saturation and then on additional reactive sites, becoming free due to silicate desorption. This present work demonstrated the importance of sorbed silicate on Fe-oxides in the prediction of reactive transport of organic species on natural surfaces.

Zinc and lead transfer in a contaminated roadside soil: experimental study and modeling

The application of a surface complexation model to simulate the sorption of metals on single sorbents is very well investigated, but very little is known regarding the use of surface complexation modeling to simulate the metal mobility in contaminated roadside soils. The overall objective of this study was to examine whether the use of the surface complexation model (SCM) could correctly describe the migration of zinc and lead in roadside soil under various physicochemical conditions. The release and transport of Zn and Pb was studied by means of batch reactors and saturated chromatography columns. Soil batch experiments were conducted to evaluate the effects of pH variation and ionic strength on the metal mobility from soil. Elution of Pb and Zn was examined in column experiments by using acetic acid at pH5 and EDTA at pH7. The modeling work has focused on the development of a SCM using MINTEQ2 database incorporated in PHREEQC-2 to describe the interactions between trace metals and the main mineral soil components (quartz, iron and aluminum oxides). In this study, it was found that the SCM was able to simulate the mobility of metals from soil by assuming one mononuclear surface reaction between one solution species (Me(2+)) and one type of site on the surface of soil dominant sorbents.

Sorption of 1-hydroxy-2-naphthoic acid to goethite, lepidocrocite and ferrihydrite: batch experiments and infrared study

The adsorption of naphthoic acids to iron oxides and hydroxides influences strongly their mobility in soils and sediments. Sorption of 1-hydroxy-2-naphthoic acid (HNA) to three iron oxides was examined over a wide range of conditions (pH, ionic strength, sorbate and sorbent concentrations). In the examination of HNA sorption, Tempkin model was performed to fit sorption data of HNA onto all iron oxides. The adsorption in the Henry law range increases in the order: goethite<lepidocrocite<ferrihydrite, while at high sorbate equilibrium concentration, the trend is opposite. Structure of the HNA surface complexes was examined by infrared spectroscopy at different surface coverages and pH conditions. The variation of HNA sorption with solid-to-solution ratio (SSR) in batch experiments exhibited a solid effect for tested oxides except goethite. The role of hydrophobicity in HNA sorption and an eventual formation of solute aggregation on the solid surface have been particularly highlighted on goethite. These results indicate that the mineralogy of the iron oxides and pH value should be considered when predicting HNA sorption in iron oxides and its fate in soil and environment.

Sorption of two aromatic acids onto iron oxides: Experimental study and modeling

The transport of aromatic carboxylate compounds in the environment can be strongly influenced by adsorption onto certain minerals, such as iron oxides and hydroxides, found in ground water and soils. Batch experiments with five iron oxides were conducted to quantify the contributions to adsorption from different iron mineral surfaces and compare adsorption characteristics of selected organic acids (gentisic acid (GA) and 1-hydroxy-2-naphthoic acid (HNA)). Because of their widespread abundance in soils and sediments, goethite, lepidocrocite, ferrihydrite, hematite, and magnetite were investigated. Sorption of two organic acids onto iron oxides was examined over a wide range of conditions (pH, ionic strength, and sorbate concentration). Specific surface area and mineral surface charge proved be important for the adsorption of these compounds. The sorption isotherm was described well by the Tempkin equation for both organic acids, with the adsorption constant higher for HNA than GA. For modeling the sorption edges of ferrihydrite and hematite, surface reactions involving the formation of mononuclear (1:1) surface species were proposed. These results indicate that the generalized two-layer model, with the assumption of homogeneous surface sites, could predict sorption on iron oxides over a range of pH conditions. The results of this study suggest that the mineralogy of the iron oxides and the pH value should be considered when predicting sorption of aromatic acids onto iron oxides and their fate in the soil and the environment.

Assessment of the multi-compound non-equilibrium dissolution behaviour of a coal tar containing PAHs and phenols into water

Herein, an experimental study coupled with a model in order to assess the non-equilibrium and multi-compound dissolution behaviour of a coal tar containing PAHs and phenols into water, is presented. For this aim, two experimental studies has been carried out: (1) coal tar-water partition equilibrium and (2) dissolution dynamics of coal tar under controlled hydrodynamic conditions in percolation columns packed with glass beads. The dissolution amount of the three target constituents (i.e. phenol, naphthalene and phenanthrene) was monitored by UV detection. The dissolution behaviour was modelled using a predictive fraction approach. The partition coefficients have been estimated from experimental data and the obtained results show that the partition coefficient of each constituent between the aqueous phase and the tar depends on the activities of the constituent in both phases and cannot be estimated only from the solubility of the pure compound in water. The non-equilibrium dissolution model was established, applied for the experimental conditions and validated for three target compounds adjusting the effective interfacial area between tar and water. This parameter is specific of the experimental set-up. The global behaviour of coal tar has been modelled taking into account four categories of compounds according to their water solubility and volatilities. The mass transfer parameters have been estimated using available correlations. The results of this paper indicate that a model based on component fractions can be used to assess the non-equilibrium dissolution behaviour of a coal tar.