Effects of phosphate addition on the removal of disinfection by-product formation potentials by biological activated carbon filtration.

In drinking water treatment plants (DWTPs), the widely used biological activated carbon filters (BACFs), as the last barrier before disinfection, can remove dissolved organic matter (DOM) known as precursors of disinfection by-products (DBPs). Whether phosphate addition can improve water purification and DBP control of BACFs is still controversial. This study investigated short-term and long-term effects of phosphate addition on controlling DBP formation potentials (FPs) by BACFs via column and batch experiments. The BAC columns presented good water purification performance: they removed around 50 % DOM, nearly all fulvic acid-likes and humic acid-likes as well as 5 %-70 % chlor(am)innated THM4, HAA9 and HAN4 FPs (except chloraminated THM4 FPs)， which was mainly contributed by aerobic bacteria not anoxic bacteria. Phosphate addition within 7-14 days further improved removals of DOM, aromatic organics, fluorescence fractions in DOM as well as HAA9 and HAN4 FPs (especially TCAA FP and TCAN FP) to different extent. However, this improvement did not last longer, and removals of DOM, aromatic organics, two fluorescence fractions (soluble microbial byproduct-likes and humic acid-likes) and DBP FPs decreased despite long-term phosphate addition. Oxic and anoxic batch experiments showed that the positive response of water purification to short-term phosphate addition was also mainly attributed to aerobic bacteria and not to anoxic bacteria. For example, the former decreased DOM and DBP FPs, while the latter increased protein- and tryptophan-like substances as well as chloraminated THM4 FPs. Phosphate addition resulted in EPS increase in anoxic reactors and decrease in oxic reactors. These results indicated that a high dissolved oxygen in BACFs may be helpful for water purification and DBP control. Overall, short-term phosphate addition into phosphorus-limited water is beneficial for BACFs to control DBPs while long-term addition has no effect. Therefore, an intermittent phosphate addition into BACFs is suggested to control DBPs in DWTPs.

Nitro- and oxy-PAHs in grassland soils from decade-long sampling in central Europe.

Long-term exposure to polycyclic aromatic hydrocarbons (PAHs) and their nitrated (NPAHs) and oxygenated (OPAHs) derivatives can cause adverse health effects due to their carcinogenicity, mutagenicity and oxidative potential. The distribution of PAH derivatives in the terrestrial environment has hardly been studied, although several PAH derivatives are ubiquitous in air and long-lived in soil and water. We report the multi-annual variations in the concentrations of NPAHs, OPAHs and PAHs in soils sampled at a semi-urban (Mokrá, Czech Republic) and a regional background site (Kosetice, Czech Republic) in central Europe. The concentrations of the Σ18NPAHs and the Σ11+2OPAHs and O-heterocycles were 0.31 ± 0.23 ng g-1 and 4.03 ± 3.03 ng g-1, respectively, in Kosetice, while slightly higher concentrations of 0.54 ± 0.45 ng g-1 and 5.91 ± 0.45 ng g-1, respectively, were found in soil from Mokrá. Among the 5 NPAHs found in the soils, 1-nitropyrene and less so 6-nitrobenzo(a)pyrene were most abundant. The OPAHs were more evenly distributed. The ratios of the PAH derivatives to their parent PAHs in Kosetice indicate that they were long-range transported to the background site. Our results show that several NPAHs and OPAHs are abundant in soil and that gas-particle partitioning is a major factor influencing the concentration of several semi-volatile NPAHs and OPAHs in the soils. Complete understanding of the long-term variations of NPAH and OPAH concentrations in soil is limited by the lack of kinetic data describing their formation and degradation.

Spatial and temporal distribution of the currently-used and recently-banned pesticides in arable soils of the Czech Republic.

This study presents monitoring data on the spatial and temporal occurrence of pesticide residues in arable soils of the Czech Republic and relates it to soil properties, pesticide usage and data on application provided by farmers. In total, 34 soils were sampled during 2014-2017, amounting to 136 samples which were analyzed for 60 pesticides and four transformation products. Conazole fungicides were frequently present in soils above the limit of quantification and/or above the 0.01 mg/kg threshold. Of the other pesticide types, the herbicides diflufenican, chlorotoluron, metolachlor, pendimethalin and terbuthylazine, fungicides azoxystrobin, carbendazim, fenpropidin, fenpropimorph and prochloraz and the insecticide methoxyfenozide were found in ≥20% of soils in at least one sampling campaign. Soils typically (>50%) contained 2-7 residues with a maximum of 14. For the 136 samples, 116 different mixtures were identified. The occurrence of pesticides was driven by their annual usage, their half-lives in soil, and their hydrophobicity. A comparison of the monitoring data and pesticide application data provided by farmers revealed that 63% of the applied pesticides are not likely to persist until the following growing season while up to 69% of pesticide residues found in soils could be inherited from the previous growing season(s).

Predicting impacts of water conservation with a stochastic sewer model.

Population growth and climate change put a strain on water resources; hence, there are growing initiatives to reduce water use. Reducing household water use will likely reduce sewer input. This work demonstrates the use of a stochastic sewer model to quantify the effect water conservation has on sewer hydraulics and wastewater concentration. Probabilistic discharge patterns have been developed using SIMDEUM WW® and fed into hydraulic modelling software InfoWorks ICM® to produce likely flow and quality profiles for five future water use scenarios. The scenarios tested were developed to outline how commercial and political factors may change water use in future. Scenario testing revealed that 15-60% water reduction reflected a 1-48% drop in the morning peak flow. The water use reduction was predicted to increase wastewater concentrations of chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN) and total phosphorus (TPH) by 55-180%, 19-116% and 30-206% respectively. The sewer flow model was developed, calibrated and validated using a case study in the Wessex Water region of the UK and all future scenarios were compared to the validated baseline case. This wastewater flow and quality model allows scenario testing, which could help redesign future sewer networks to better prepare for water conservation strategies.

Laboratory versus field soil aging: Impact on DDE bioavailability and sorption.

Solid-phase microextraction (SPME), XAD, and the sequential supercritical fluid extraction (SFE) were used to assess the influence of aging of p,p'-DDE in a laboratory contaminated soil for up to 730 days. The end points determined were the freely dissolved concentration (Cfree) using SPME, the potentially bioaccessible fraction (FXAD, %) and the distribution of p,p'-DDE among fast, moderate, and slow desorbing soil sites determined by three sequentially stronger SFE conditions. Cfree and FXAD decreased during the first 35 days of aging by up to 40%. After this, no significant changes were observed up to the end of the aging experiment. The relative percentage of fast desorbing sites tended to exponentially decrease with aging, while the percentage of moderate and slow desorbing sites increased over time. These changes were most apparent within the first 90 days of aging, after which the relative distribution of p,p'-DDE among desorbing sites remained relatively constant. Significant correlations between SFE and XAD results demonstrated that the XAD method preferentially desorbed p,p'-DDE from fast and moderate desorbing sites and is capable of extracting the bioaccessible fraction. The distribution among desorbing sites, Cfree and FXAD values determined after different periods of laboratory aging were then compared to those measured for a field-contaminated soil where p,p'-DDE had resided for more than 40 years. Cfree, FXAD and SFE profiles measured for the field-aged p,p'-DDE were similar to those observed for p,p'-DDE aged in laboratory for between 35 and 90 days. These results suggest that aging in the laboratory must be carried out for periods of months if it is to approximate field aging.

Association between severe disease course and nephritis with Q222R polymorphism in DNAse I gene among lupus patients: An Argentine multicenter study.

UNLABELLED: Objetives: Systemic lupus erythematosus is a multifactorial autoimmune disease and the glomerulonephritis is one of the most severe complications, which leads to severe persistent proteinuria, chronic renal failure, and end-stage renal disease. This multicenter study investigated the genetic associations of a non-synonymous single-nucleotide polymorphism in DNase I with the risk of lupus and its influence on development of nephropathy in an Argentinean population. METHODS: Using the Polymerase chain reaction restriction fragment length polymorphism method, the Q222R (+2373A→G; Gln244Arg) DNase I polymorphism was studied in 156 systemic lupus erythematosus patients and 170 healthy controls. RESULTS: Although no significant association between Q222R polymorphism and the risk of systemic lupus erythematosus was found, the presence of the A allele was associated with an increased risk for the development of nephropathy (p=0.019, Odd Ratio=2.196, 95 % confidence interval [1.135-4.247]) and a worse disease course [moderate disease course: p=0.006, Odd Ratio=3.250, 95% confidence interval (1.401-7.539); severe disease course: p=0.040, Odd Ratio=2.339, 95% confidence interval (1.040-5.260)]. CONCLUSIONS: A better understanding of the genetic basis of systemic lupus erythematosus will help in the development of new and more effectives strategies for the treatment of the disease in the future.

Assessment of the biological and chemical availability of the freshly spiked and aged DDE in soil.

The study compared the ability of various chemical methods (XAD, ß-hydroxypropylcyclodextrin - HPCD) and solid phase micro-extraction (SPME)) to mimic earthworm uptake from two similar soils containing either spiked or aged p,p´-DDE, thus representing two extreme scenarios with regard to the length of pollutant-soil contact time and the way of contamination. The extent of bioaccumulation was assessed at fixed exposure periods (10 and 21 days) and at equilibrium derived from uptake curves by multiple-point comparison or kinetic modeling. The decision on the best chemical predictor of biological uptake differed. The degree of bioaccumulation at equilibrium was best predicted by XAD while HPCD rather reflected the extent of accumulation derived after 21 days when, however, steady-state was not reached for spiked p,p´-DDE. SPME seemed to underestimate the uptake of aged p,p´-DDE, probably of the fraction taken up via soil particles. Thus, the degree of predictability seems to be associated with the capability of the chemical method to mimic the complex earthworm uptake via skin and intestinal tract as well as with the quality of biological data where the insufficient length of exposure period appears to be the major concern.

Ensuring effective Essential Obstetric Care in resource poor settings.

Although Emergency Obstetric Care (EOC) is globally accepted as a key strategy to improve maternal health and reduce maternal mortality, there is still a lot of debate surrounding its use--What is EOC? Is it evidence-based? How can we measure it? How can we improve access to EOC? This paper attempts to answer these questions. Although there are no randomized controlled trials, there is strong evidence from quasi-experimental, observational and ecological studies that EOC should be a critical component of any programme to reduce maternal mortality. This paper also identifies the barriers to accessing EOC and proposes strategies to overcome them which could contribute to achieving Millennium Development Goal 5.

Using supercritical fluid extraction to measure the desorption and bioaccessibility of phenanthrene in soils.

The aim of this paper was to measure the changing desorbable fraction and bioaccessibility of phenanthrene in two different soils with increasing soil-phenanthrene contact time using supercritical fluid extractions (SFE). Both soils were spiked with 100 mg kg(-1) phenanthrene and aged for 28d. Desorption profiles were measured every 7d using selective SFE conditions and the results were compared to 14C-phenanthrene mineralisation assays. Selective SFE showed significant differences in the rates and extents of desorption in the two soils, likely to be due to different organic matter composition. Post-extraction fitting of data yielded consistent SFE extraction times within ageing soils for bioaccessibility prediction.

Toxicity of four nitrogen-heterocyclic polyaromatic hydrocarbons (NPAHs) to soil organisms.

The aims of this study were: (i) to investigate the toxicity of N-heterocyclic polyaromatic hydrocarbons (NPAHs) quinoline, acridine, phenazine, and 1,10-phenanthroline to the soil invertebrates Eisenia fetida, Enchytraeus crypticus, Folsomia candida, and Caenorhabditis elegans, (ii) to compare the toxicity of four NPAHs and the species sensitivity, and (iii) to discuss possible risks of these compounds in soils. Different toxicities were found for the tested NPAHs which might be partially explained by their structure and properties. Effect concentrations expressed as soil pore-water concentrations were related to log K(ow), which indicated narcosis as the most probable mode of toxic action. The species sensitivity decreased in the rank: springtails >enchytraeids=earthworms> nematodes. Predicted no-effect concentration (PNEC) values were calculated for all tested species giving values from 0.5 to 6.8 mg/kg. It is unlikely that there is a risk for soil organisms in natural soils where lower NPAHs concentrations are expected.

Adaptación al español y validación del cuestionario de detección epidemiológica para artritis reumatoidea / Adaptation and validation to Spanish of rheumatoid arthritis epidemiology detection questionnaire

La detección epidemiológica de la artritis reumatoidea constituye un desafío, dado lo proteiforme de su presentación, por lo que la generación o adaptación y validación de instrumentos es de vital importancia. El objetivo de este estudio es la adaptación lingüística y validación al castellano de un cuestionario utilizado previamente (The prevalence of rheumatoid arthritis in Sweden. Scand J Rheumatol 1999; 28:340-3). Se utilizó una muestra de pacientes con artritis reumatoidea conocida (criterios ACR 87) y controles sanos (N total = 100) para estimar las propiedades de factibilidad, fiabilidad, validez, sensibilidad y especificidad. La sensibilidad del instrumento fue del 100 por ciento (96,9-100), especificidad 94,1 por ciento (88,4-99,7), con un coeficiente Kappa 0,83 (IC95 por ciento: 0,70-0,97) p <0,01. La concordancia entre las preguntas resultó significativa, con Kappa 0,81 (IC95 por ciento: 0,66-0,96) p <0,01 y la consistencia interna mostró un coeficiente de Cronbach 0,892. El análisis factorial exploratorio mostró dosdimensiones coherentes con la versión original.

Polimiositis: presentación inusual / Polymyositis: an unusual presentation

La miopatía inflamatoria aguda con severo edema subcutáneo es extremadamente rara y ha sido descripta en unos pocos casos. Presentamosun paciente con una polimiositis que cursó con edema localizado de tronco y miembros superiores.

Quantification of atherosclerotic plaque components using in vivo MRI and supervised classifiers.

In this work we aimed to study the possibility of using supervised classifiers to quantify the main components of carotid atherosclerotic plaque in vivo on the basis of multisequence MRI data. MRI data consisting of five MR weightings were obtained from 25 symptomatic subjects. Histological micrographs of endarterectomy specimens from the 25 carotids were used as a standard of reference for training and evaluation. The set of subjects was divided in a training set (12 subjects) and an evaluation set (13 subjects). Four different classifiers and two human MRI readers determined the percentages of calcified tissue, fibrous tissue, lipid core, and intraplaque hemorrhage on the subject level for all subjects in the evaluation set. Quantification of the relatively small amounts of calcium could not be done with statistical significance by either the classifiers or the MRI readers. For the other tissues a simple Bayesian classifier (Bayes) performed better than the other classifiers and the MRI readers. All classifiers performed better than the MRI readers in quantifying the sum of hemorrhage and lipid proportions. The MRI readers overestimated the hemorrhage proportions and tended to underestimate the lipid proportions. In conclusion, this pilot study demonstrates the benefits of algorithmic classifiers for quantifying plaque components.

Differentiation of IgE-dependent and IgE-independent reactions in children with bronchial asthma on the basis of TOP CAST Paediatric Allergen Mix test.

PURPOSE: TOP CAST Paediatric Allergen Mix test is a new cellular in vitro test based on evaluation of leukotrienes synthesised by basophils under the influence of specific allergens. The aim of the study was evaluation of applicability of this test as screening examination in diagnosis of atopic asthma in children. MATERIAL AND METHODS: The study was carried out on a group of 30 children (56.7% boys and 43.3% girls) aged 6-15 yrs (mean age 8 years and 9 months, SD = 2.1) with diagnosed bronchial asthma. In children qualified for the study clinical symptoms, subject examination as well as functional examination of the respiratory system (obturation with positive reversibility test) confirmed the disease. All the children had skin prick tests performed with the most popular aero- and troph-allergens, which results were expressed (+) according to the Skandinavian scale. In 15 cases asthma had atopic origin: in 11 children--mites were responsible for the contraction of bronchi, in 3 cases--tree-pollens allergens and in 1 case--grass pollens. In 15 next cases non-atopic asthma was diagnosed. The control group consisted of 10 children without clinical manifestations of asthma and negative results of the above tests. Test TOP CAST Paediatric Allergen Mix with mixture of 21 inhalatory and food allergens was performed according to the producer's procedure. RESULTS: Statistically significant differences of the values of released leukotrienes were noted at allergen concentration of both 100 ng/ml and 10 ng/ml in children with diagnosed atopic asthma compared to those with non-atopic asthma and control group. The sensitivity of TOP CAST Paediatric Allergen Mix test was 80% at both allergen concentrations while the specificity was higher (90%) at the lower concentration. There was also correlation between the number of released leukotriens and IgEc in the examined group of children, however, no statistically significant differences were observed between the concentration of the released leukotrienes and the size of the wheal and the number of positive skin prick tests. CONCLUSIONS: 1. TOP CAST Paediatric Allergen Mix test is a good screening method in differentiation of atopic and non-atopic background of bronchial asthma in children. 2. At the present evaluation stage of this test, it may be applied as complementation of routine tests in allergological practice.

Lupus eritematoso sistémico (LES): perfil de severidad al ingreso hospitalario de 44 pacientes sin seguimiento postdiagnóstico / Systemic Lupus Erythematosus (SLE): Severity profile at hospital admisión of 44 patients without post-diagnosis monitoring

El grado que un paciente cumpla con el seguimiento medico y se adhiera a las indicaciones terapéuticas, se ha convertido en un punto esencial en la repercusión que tendrá sobre la evolución de su enfermedad. Es un tema de gran trascendencia sobre todo en enfermedades crónicas. El incumplimiento es grave porque hace ineficaz el tratamiento prescripto, provocando un aumento de la morbilidad. El paciente presentará complicaciones y secuelas que pueden acarrear lesiones de tipo irreversibles. En el Lupus Eritematoso Sistémico, la adherencia al tratamiento es de suma trascendencia en el control de su enfermedad. El presente estudio tiene como objetivo valorar el impacto que provoca la falta de cumplimiento al tratamiento y el abandono al seguimiento médico. Concomitantemente se evaluó la prevalencia del daño en los distintos órganos y su actividad. Los datos obtenidos en el relevamiento de ingreso a nuestro hospital muestran que 44 pacientes con diagnóstico previo de LES abandonaron el seguimiento en su hospital de origen. Se revisaron las historias clínicas de los ingresados entre mayo de 1984 y de junio de 1999. Desde julio de 1999 a mayo de 2005 se obtuvieron datos en forma prospectiva según grilla prediseñada. Se definieron términos según criterios de clasificación, SLEDAI e Indice de Daño (ACR). Se evaluaron las distintas prevalencias, observándose que la gran mayoría de los pacientes presentó actividad multisistémica con mayor prevalencia en riñón. Más del 50% de los casos presentó daño irreversible con alta prevalencia en riñón y sistema nervioso. Los pacientes dañados evidenciaron mayor tiempo de evolución, pero sin diferencias estadísticamente significativas. No encontramos relación entre daño y mantenimiento del tratamiento corticoideo.

Erratum: Title of article: Why more mothers die - Confidential enquiries into institutional maternal deaths in the Southern Region of Malawi, 2001.

[This corrects the article on p. 73 in vol. 17.].

Fluticasone propionate in asthma: a long term dose comparison study.

BACKGROUND: Few dose ranging studies have investigated optimal dosing with inhaled corticosteroids in children with asthma. AIMS: To compare the efficacy and tolerability of fluticasone propionate 100 or 200 microg twice daily in children with moderate to severe asthma for one year. METHODS: One year, randomised, double blind, parallel group, multicentre study. Children aged 4-11 years (n = 528) with moderate to severe asthma who had previously received high dose inhaled corticosteroids were given fluticasone propionate 100 or 200 microg twice daily for the 52 week treatment period. Efficacy (exacerbations, lung function, and symptoms) and tolerability (adverse events and cortisol levels) were measured. RESULTS: There was a non-significant decreased risk of experiencing an exacerbation at any time with fluticasone propionate 200 microg twice daily compared with fluticasone propionate 100 microg twice daily. This difference reached significance among patients with more severe asthma (defined by previous inhaled corticosteroid dose >800 microg/day). Daily record card morning peak expiratory flow (PEF) in the total population improved significantly more with the higher dose of fluticasone propionate (between group difference, weeks 1-52: 11.4 l/min). Clinic visit mean PEF improved from baseline with both doses, but the response was significantly greater with the higher dose (between group difference, week 52: 17.8 l/min). Both doses were equally well tolerated and overnight urinary cortisol concentrations were unchanged or slightly increased during treatment with either dose. CONCLUSION: This long term dose comparison study shows that treatment with fluticasone propionate 200 micro g twice daily may offer benefits over a lower dose, particularly in children with more severe asthma.