Hydrogeochemistry and geogenic fluoride and boron groundwater problems in the Emscher Fm. (Münsterland region, Germany)

Die Sediment- und Grundwasserchemie des Emschermergels im Münsterland (NRW) wurde untersucht. Die Geochemie (Canorg- und Spyrit) wurde an 160 Gesteinsproben analysiert. Unterhalb einer geogenen Verwitterungszone wurden unverwitterte, pyrithaltige Gesteine vorgefunden. Die Grundwasserchemie des Emschermergels in Ostwestfalen wurde anhand von 580 Einzelanalysen aus Hausbrunnen, ergänzt durch weitere Literaturdaten, zusammengetragen und ausgewertet. Die Grundwässer weisen zum Teil hohe Fluorid- und Borkonzentrationen von jeweils bis zu 10 mg/l auf – regional liegen bis zu 30 % der Wässer über 1,5 mg/l Fluorid, und bis zu 50 % über 1 mg/l Bor – die räumliche Verteilung scheint vom Vorhandensein einer Quartärüberdeckung abzuhängen. Grundwässer mit hohen Fluoridkonzentrationen zeigen geringe Ca2+-Konzentrationen und umgekehrt, was auf eine Gleichgewichtseinstellung mit der Mineralphase Fluorit hindeutet. Grenzwertüberschreitende Gehalte treten fast ausnahmslos in Ionenaustauschwässern des Na-HCO3-(Cl)-Typs mit pH > 7,5 auf. Als wahrscheinlicher Hauptmobilisierungsmechanismus beider Kontaminanten erscheint die pH-gesteuerte Desorption von Mineraloberflächen. Die geologische Primärquelle ist unbekannt, eine nähere geochemisch-mineralogische Untersuchung des Emschermergels wäre wünschenswert.The hydrogeochemistry of the Cretaceous Emscher Fm. in northwest Germany was investigated, including analysis of 160 rock samples for carbon and sulfur content. Beneath a weathered zone, unweathered rocks containing pyrite were found. Groundwater data from the Emscher Fm. (580 analyses of house wells and additional literature data) were collected and evaluated. Some groundwater contains high fluoride and boron concentrations of up to 10 mg/l. Regionally, up to 30% of house wells show fluoride concentrations above 1.5 mg/l, and up to 50% above 1 mg/l boron. The spatial distribution depends on the presence of Quaternary cover sediments. Groundwater with high fluoride concentrations displays low Ca2+, and vice versa, indicating equilibrium with the mineral fluorite (CaF2). Concentrations above drinking water guidelines almost exclusively occur in ion exchange waters of the Na-HCO3 −(Cl) type with pH > 7.5. The main mobilization mechanism of both contaminants appears to be pH-triggered desorption from mineral surfaces

Dynamics of pathogens and fecal indicators during riverbank filtration in times of high and low river levels

Riverbank filtration is an established and quantitatively important approach to mine high-quality raw water for drinking water production. Bacterial fecal indicators are routinely used to monitor hygienic raw water quality, however, their applicability in viral contamination has been questioned repeatedly. Additionally, there are concerns that the increasing frequency and intensity of meteorological and hydrological events, i.e., heavy precipitation and droughts leading to high and low river levels, may impair riverbank filtration performance. In this study, we explored the removal of adenovirus compared with several commonly used bacterial and viral water quality indicators during different river levels. In a seasonal study, water from the Rhine River, a series of groundwater monitoring wells, and a production well were regularly collected and analyzed for adenovirus, coliphages, E. coli, C. perfringens, coliform bacteria, the total number of prokaryotic cells (TCC), and the number of virus-like particles (TVPC) using molecular and cultivation-based assays. Additionally, basic physico-chemical parameters, including temperature, pH, dissolved organic carbon, and nutrients, were measured. The highest log10 reduction during the >72 m of riverbank filtration from the river channel to the production well was observed for coliforms (>3.7 log10), followed by E. coli (>3.4 log10), somatic coliphages (>3.1 log10), C. perfringens (>2.5 log10), and F+ coliphages (>2.1 log10) at high river levels. Adenovirus decreased by 1.6–3.1 log units in the first monitoring well (>32 m) and was not detected in further distant wells. The highest removal efficiency of adenovirus and most other viral and bacterial fecal indicators was achieved during high river levels, which were characterized by increased numbers of pathogens and indicators. During low river levels, coliforms and C. perfringens were occasionally present in raw water at the production well. Adenovirus, quantified via droplet digital PCR, correlated with E. coli, somatic coliphages, TCC, TVPC, pH, and DOC at high river levels. At low river levels, adenoviruses correlated with coliforms, TVPC, pH, and water travel time. We conclude that although standard fecal indicators are insufficient for assessing hygienic raw water quality, a combination of E. coli, coliforms and somatic coliphages can assess riverbank filtration performance in adenovirus removal. Furthermore, effects of extreme hydrological events should be studied on an event-to-event basis at high spatial and temporal resolutions. Finally, there is an urgent need for a lower limit of detection for pathogenic viruses in natural waters. Preconcentration of viral particles from larger water volumes (>100 L) constitutes a promising strategy

Canagliflozin and renal outcomes in type 2 diabetes and nephropathy

BACKGROUND Type 2 diabetes mellitus is the leading cause of kidney failure worldwide, but few effective long-term treatments are available. In cardiovascular trials of inhibitors of sodium–glucose cotransporter 2 (SGLT2), exploratory results have suggested that such drugs may improve renal outcomes in patients with type 2 diabetes. METHODS In this double-blind, randomized trial, we assigned patients with type 2 diabetes and albuminuric chronic kidney disease to receive canagliflozin, an oral SGLT2 inhibitor, at a dose of 100 mg daily or placebo. All the patients had an estimated glomerular filtration rate (GFR) of 30 to <90 ml per minute per 1.73 m2 of body-surface area and albuminuria (ratio of albumin [mg] to creatinine [g], >300 to 5000) and were treated with renin–angiotensin system blockade. The primary outcome was a composite of end-stage kidney disease (dialysis, transplantation, or a sustained estimated GFR of <15 ml per minute per 1.73 m2), a doubling of the serum creatinine level, or death from renal or cardiovascular causes. Prespecified secondary outcomes were tested hierarchically. RESULTS The trial was stopped early after a planned interim analysis on the recommendation of the data and safety monitoring committee. At that time, 4401 patients had undergone randomization, with a median follow-up of 2.62 years. The relative risk of the primary outcome was 30% lower in the canagliflozin group than in the placebo group, with event rates of 43.2 and 61.2 per 1000 patient-years, respectively (hazard ratio, 0.70; 95% confidence interval [CI], 0.59 to 0.82; P=0.00001). The relative risk of the renal-specific composite of end-stage kidney disease, a doubling of the creatinine level, or death from renal causes was lower by 34% (hazard ratio, 0.66; 95% CI, 0.53 to 0.81; P<0.001), and the relative risk of end-stage kidney disease was lower by 32% (hazard ratio, 0.68; 95% CI, 0.54 to 0.86; P=0.002). The canagliflozin group also had a lower risk of cardiovascular death, myocardial infarction, or stroke (hazard ratio, 0.80; 95% CI, 0.67 to 0.95; P=0.01) and hospitalization for heart failure (hazard ratio, 0.61; 95% CI, 0.47 to 0.80; P<0.001). There were no significant differences in rates of amputation or fracture. CONCLUSIONS In patients with type 2 diabetes and kidney disease, the risk of kidney failure and cardiovascular events was lower in the canagliflozin group than in the placebo group at a median follow-up of 2.62 years

Who Cares? Eine ländervergleichende Analyse klimawandelbezogener Besorgnis in Europa

Dieser Beitrag untersucht ein bislang in der deutschsprachigen Klimaforschung weithin vernachlässigtes Thema: Die Besorgnis über den Klimawandel in der Bevölkerung. Auf der Grundlage eines zeitdiagnostischen Zugangs, der von der zentralen Bedeutung von Sorgen in der Gegenwartsgesellschaft ausgeht, untersuchen wir in einem ersten Schritt mittels eines internationalen Literaturüberblicks den Forschungsstand zur Wahrnehmung des Klimawandels in der Bevölkerung mit Schwerpunkt auf der Dimension der Klimabesorgnis. Davon ausgehend leiten wir Hypothesen zur Erklärung der klimabedingten Besorgnis ab, die wir mittels einer Mehrebenenanalyse und auf Basis von Daten des European Social Survey empirisch überprüfen. Die Analysen zeigen, dass Klimasorgen relativ weit verbreitet sind, sich jedoch nur in sehr geringem Maß über die Varianz zwischen Ländern erklären lassen. Vielmehr sind verschiedene soziale Prädikatoren auf Individualebene von zentraler Bedeutung. Insbesondere Variablen wie die individuelle Wertorientierung, die Gewissheit über den Klimawandel und die politische Orientierung der Befragten erweisen sich als konsistente und wirkmächtige Korrelate klimawandelbezogener Sorgen. This article investigates a rarely studied issue in climate change research in Germany: the worries about climate change among citizens. Against the backdrop of current sociological diagnoses of the times which suggest worries as of central importance in present society, we first address previous research on worries about climate change by taking a look at international research on climate change perceptions. On this basis, we formulate a set of hypotheses for explaining worries about climate change. We examine these hypotheses empirically by taking on a multi-level approach and utilizing data from the European Social Survey. The analyses show that worry about climate change depends strongly on individual attributes, rather than the country people live in. In particular, individual value orientations, climate change awareness and political attitudes prove to be consistent and important correlates of climate worries. (peer reviewed

Anthropogen bedingte Pyritoxidationsprozesse in verschiedenen Gesteinen Nordrhein-Westfalens und deren Auswirkungen auf die Grundwasserbeschaffenheit

Pyritoxidationsprozesse sind weltweit für großflächige Beeinflussungen sowohl des Grundwassers als auch von Oberflächengewässern bekannt. Primär durch den menschlichen Eingriff in Form von Baumaßnahmen oder Bergbau wird das pyrithaltige Sediment, welches unter anoxischen Bedingungen stabil ist, in Kontakt mit Sauerstoff oder anderen Oxidationsmittels wie Fe$^{3+}$ oder NO$_{3-}$ gebracht und sorgt unter der Freisetzung von Sulfid- und Eisenacidiät zu einer erheblichen Versauerung von Grund- und Oberflächengewässern. In Anlehnung an die ursächliche Verbindung zum Bergbau werden die entstehenden Wässer auch Acid Mine Drainage genannt. Zusätzlich zu den typischen Reaktionsprodukten wie Eisen, Sulfat und Säure kann die Verwitterung der Disulfide auch zu einer Mobilisierung von Schwermetallen führen. Im Rahmen von drei durchgeführten Forschungsprojekten wurden an pyrithaltigen Sedimenten umfangreiche Laborversuche durchgeführt, um die Pyritoxidation sowie deren Reaktionsprodukte zu quantifizieren

Photo-Switchable Surfactants for Responsive Air–Water Interfaces: Azo versus Arylazopyrazole Amphiphiles

Arylazopyrazoles (AAPs) as substitutes for azo derivatives have gained considerable attention due to their superior properties offering E/Z photo-isomerization with high yield. In order to compare and quantify their performance, azobenzene tetraethylammonium (Azo-TB) and arylazopyrazole tetraethylammonium (AAP-TB) bromides were synthesized and characterized in the bulk (water) using NMR spectroscopy. At the air-water interface complementary information from vibrational sum-frequency generation (SFG) spectroscopy and neutron reflectometry (NR) has revealed the effects of E/Z isomerization in great detail. In bulk water the photostationary states of >89% for E/Z switching in both directions were very similar for the surfactants, while their interfacial behavior was substantially different. In particular, the surface excess $\Gamma$ of the surfactants changed drastically between E/Z isomers for AAP-TB (maximum change of $\Gamma$: 2.15 $\mu$mol/m$^2$); for Azo-TB the change was only moderate (maximum change of $\Gamma$: 1.02 $\mu$mol/m$^2$). Analysis of SFG spectra revealed that strong non-resonant contributions that heterodyned the resonant vibrational bands were proportional to $\Gamma$, enabling the aromatic C-H band to be interpreted as an indicator for changes in interfacial molecular order. Close comparison of $\Gamma$ from NR with the SFG amplitude from the aromatic C-H stretch as a function of concentrations and E/Z conformation revealed substantial molecular order changes for AAP-TB. In contrast, only $\Gamma$ and not the molecular order varied for Azo-TB. These differences in interfacial properties are attributed to the molecular structure of the AAP center that enables favorable lateral interactions at the air-water interface, causing closed-packed interfacial layers and substantial changes during E/Z photo-isomerization.Comment: Pre-edited final version, 36 manuscript pages, 2 tables, 6 figures. Supporting Information available up request to the corresponding autho

Incidence of lower extremity amputations in the diabetic compared with the non-diabetic population: A systematic review

<div><p>Lower extremity amputation (LEA) in patients with diabetes results in high mortality, reduced quality of life, and increased medical costs. Exact data on incidences of LEA in diabetic and non-diabetic patients are important for improvements in preventative diabetic foot care, avoidance of fatal outcomes, as well as a solid basis for health policy and the economy. However, published data are conflicting, underlining the necessity for the present systematic review of population-based studies on incidence, relative risks and changes of amputation rates over time. It was conducted according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. Nineteen out of 1582 studies retrieved were included in the analysis. The incidence of LEA in the diabetic population ranged from 78 to 704 per 100,000 person-years and the relative risks between diabetic and non-diabetic patients varied between 7.4 and 41.3. Study designs, statistical methods, definitions of major and minor amputations, as well as the methods to identify patients with diabetes differed greatly, explaining in part these considerable differences. Some studies found a decrease in incidence of LEA as well as relative risks over time. This obvious lack of evidence should be overcome by new studies using a standardized design with comparable methods and definitions.</p><p>Systematic review registration number</p><p>PROSPERO <a href="https://clinicaltrials.gov/ct2/show/CRD4201501780" target="_blank">CRD4201501780</a></p></div

Incidence of LEA in the diabetic compared with the non-diabetic populations—Study characteristics.

<p>Incidence of LEA in the diabetic compared with the non-diabetic populations—Study characteristics.</p

Relative risks of any LEA (hospital discharge rates) in the diabetic compared with the non-diabetic population.

<p>* 95% Confidence interval was not reported.</p