The halogenation of quorum sensing molecules (QSMs) is known to be catalyzed by enzymes such as haloperoxidase (HPO) as well as cerium dioxide nanocrystals (NC), which mimic enzymes. Those enzymes ...and mimics can influence biological processes such as biofilm formation, where bacteria use QSMs for the "chemical" communication between each other and the coordination of surface colonization. However, not much is known about the degradation behavior of a broad spectrum of QSMs, especially for HPO and its mimics. Therefore, in this study, the degradation of three QSMs with different molecule moieties was elucidated. For this purpose, different batch experiments were carried out with HPOs, NCs and free active bromine (FAB). For
-β-ketocaproyl-homoserine lactone (3-Oxo-C
-AHL),
-
-tetradec-9
-enoyl-homoserine lactone (C
-AHL) and 2-heptyl-4-quinolone (HHQ) a fast degradation and moiety-specific transformations were observed. The HPO vanadium bromoperoxidase as well as cerium dioxide NCs catalyzed the formation of the same brominated transformation products (TPs). Since the same TPs are formed in batch experiments with FAB it is very likely that FAB is playing a major role in the catalytical reaction mechanism leading to the transformation of QSMs. In this study in total 17 TPs could be identified in different levels of confidence and the catalytic degradation processes for two QS groups (unsaturated AHLs and alkyl quinolones) with cerium dioxide NCs and vanadium bromoperoxidase were expanded.
The electrochemical treatment of low-salinity reverse osmosis (RO) concentrates was investigated using tramadol (100 μM) as a model substance for persistent organic contaminants. Galvanostatic ...degradation experiments using boron-doped diamond electrodes at different applied currents were conducted in RO concentrates as well as in ultra-pure water containing either sodium chloride or sodium sulfate. Kinetic investigations revealed a significant influence of in-situ generated active chlorine besides direct anodic oxidation. Therefore, tramadol concentrations decreased more rapidly at elevated chloride content. Nevertheless, reduction of total organic carbon (TOC) was found to be comparatively low, demonstrating that transformation rather than mineralization was taking place. Early stage product formation could be attributed to both direct and indirect processes, including demethylation, hydroxylation, dehydration, oxidative aromatic ring cleavage and halogenation reactions. The latter led to various halogenated derivatives and resulted in AOX (adsorbable organic halogens) formation in the lower mg/L-range depending on the treatment conditions. Characterisation of transformation products (TPs) was achieved via MSn experiments and additional NMR measurements. Based on identification and quantification of the main TPs in different matrices and on additional potentiostatic electrolysis, a transformation pathway was proposed.
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•Galvanostatic electrochemical transformation of tramadol in reverse osmosis brines.•Identification of transformation products during electrochemical treatment.•Elucidation of the transformation pathway.
The European Union (EU) Project Routes aimed to discover new routes in sludge stabilization treatments leading to high-quality digested sludge, suitable for land application. In order to investigate ...the impact of different enhanced sludge stabilization processes such as (a) thermophilic digestion integrated with thermal hydrolysis pretreatment (TT), (b) sonication before mesophilic/thermophilic digestion (UMT), and (c) sequential anaerobic/aerobic digestion (AA) on digested sludge quality, a broad class of conventional and emerging organic micropollutants as well as ecotoxicity was analyzed, extending the assessment beyond the parameters typically considered (i.e., stability index and heavy metals). The stability index was improved by adding aerobic posttreatment or by operating dual-stage process but not by pretreatment integration. Filterability was worsened by thermophilic digestion, either alone (TT) or coupled with mesophilic digestion (UMT). The concentrations of heavy metals, present in ranking order Zn > Cu > Pb > Cr ~ Ni > Cd > Hg, were always below the current legal requirements for use on land and were not removed during the processes. Removals of conventional and emerging organic pollutants were greatly enhanced by performing double-stage digestion (UMT and AA treatment) compared to a single-stage process as TT; the same trend was found as regards toxicity reduction. Overall, all the digested sludges exhibited toxicity to the soil bacterium Arthrobacter globiformis at concentrations about factor 100 higher than the usual application rate of sludge to soil in Europe. For earthworms, a safety margin of factor 30 was generally achieved for all the digested samples.
The physical damages to benthic organisms caused by boat anchorages were assessed in the Arraial do Cabo Marine Extractive Reserve (ACMER), Brazil. It is one of the most visited scuba diving sites ...along the southwestern Atlantic. Through underwater visual observations, we analyzed if benthic organisms were damaged by anchors and/or anchor cabling at two dive sites. A total of 112 anchorages were sampled. Damages to benthic organisms were observed 139 times, mainly affecting epilithic algal matrix, the zoanthid Palythoa caribaeorum, and the fire coral Millepora alcicornis. Damages caused by anchor cables were significantly higher than those caused by anchors at one site. A significant difference between benthic organisms damaged was observed only for P. caribaeorum, caused by the anchor's cable. We present evidence that, at current visitation levels, anchors are a relevant Stressor to benthic organisms at dive sites in ACMER.
This study investigated the long-term fate of
3H-ivermectin and its metabolites in aerobic sediment/water systems. Total radioactivity in sediment and water was measured by Liquid Scintillation ...Counting and Radio-HPLC was used for determination of transformation products.
The test system, containing a cooling and a water trap, showed excellent applicability for studying environmental fate of
3H-labelled compounds. A complete mass balance was obtained over the whole duration with total recoveries ranging from 91.3% to 98.8%. In water, a DT
50-value of ivermectin of <6
h and a DT
90-value of 16.8 d were obtained. The DT
50-value of ivermectin in the entire system was 127
d. Maximum distribution coefficients were calculated to
K
d
=
160 L kg
−1 and
K
oc
=
3550 L kg
−1. The fraction of bound residues increased to a maximum percentage of 30.4% after 188 d. In total about 31.3% of the initially applied ivermectin were transformed after 188 d. Two transformation products ivermectin monosaccharide and ivermectin aglycone, could be identified in samples from day 100 and 188, respectively. However, additional peaks which were observed in the radio-chromatograms indicate that several other transformation product are formed.
We discuss in detail the dependence of the Gallium Anomaly on the detection cross section. We provide updated values of the size of the Gallium Anomaly and find that its significance is larger than ...about \(5\sigma\) for all the detection cross section models. We discuss the dependence of the Gallium Anomaly on the assumed value of the half life of \({}^{71}\text{Ge}\), which determines the cross sections of the transitions from the ground state of \({}^{71}\text{Ga}\) to the ground state of \({}^{71}\text{Ge}\). We show that a value of the \({}^{71}\text{Ge}\) half life which is larger than the standard one can reduce or even solve the Gallium Anomaly. Considering the short-baseline neutrino oscillation interpretation of the Gallium Anomaly, we show that a value of the \({}^{71}\text{Ge}\) half life which is larger than the standard one can reduce the tension with the results of other experiments. Since the standard value of the \({}^{71}\text{Ge}\) half life was measured in 1985, we advocate the importance of new measurements with modern technique and apparatus for a better assessment of the Gallium Anomaly.
We investigate the potential impact of neutrino quantum decoherence on the precision measurements of standard neutrino oscillation parameters in the DUNE and T2HK experiments. We show that the ...measurement of \(\delta_\text{CP}\), \(\sin^2\theta_{13}\) and \(\sin^2\theta_{23}\) is stronger effected in DUNE than in T2HK. On the other hand, DUNE would have a better sensitivity than T2HK to observe decoherence effects. By performing a combined analysis of DUNE and T2HK we show that a robust measurement of standard parameters would be possible, which is not guaranteed with DUNE data alone.
Angiotensin receptor–neprilysin inhibitor (ARNI) therapy has been associated with improved survival for patients with symptomatic heart failure and reduced ejection fraction (HFrEF).
We performed a ...meta-analysis of arrhythmia endpoints from studies comparing ARNI with angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) for patients with HFrEF to assess for incremental benefit.
We searched PubMed, Embase, and ClinicalTrials.gov. Baseline study characteristics were collected and outcomes were sustained ventricular arrhythmias, atrial arrhythmias, appropriate implantable cardioverter-defibrillator (ICD) therapy, sudden cardiac death (SCD), and biventricular (BiV) pacing rate.
We included 9 studies, 4 randomized trials, and 5 observational studies (5589 patients on ARNI vs 5615 on ACEIs/ARBs). Follow-up ranged from 2 to 51 months. The mean age was 65.4 ± 9.8 years, with 77.3% male patients and a mean ejection fraction of 29.0% ± 7.6%. Ischemic cardiomyopathy was present in 62% of patients. In the ARNI group, there were less SCD (odds ratio OR 0.78, 95% confidence interval CI 0.63–0.96; P = .02), ventricular arrhythmias (OR 0.45, 95% CI 0.25–0.79; P = .005), and appropriate ICD therapy (OR 0.39, 95% CI 0.21–0.74; P = .004). Higher rates of BiV pacing were seen (mean difference 3.13, 95% CI 2.58–3.68; P < .00001) when compared with ACEIs/ARBs. No difference in atrial arrhythmias was seen.
ARNI therapy provides incremental benefit with respect to ventricular tachyarrhythmias/SCD, which may, in part, explain improved outcomes in patients with HFrEF compared to ACEIs/ARBs. There was increased BiV pacing and decreased ICD therapy in the ARNI group.
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