The secretome from human-derived mesenchymal stem cells augments the activity of antitumor plant extracts in vitro.

Cancer is understood as a multifactorial disease that involve multiple cell types and phenotypes in the tumor microenvironment (TME). The components of the TME can interact directly or via soluble factors (cytokines, chemokines, growth factors, extracellular vesicles, etc.). Among the cells composing the TME, mesenchymal stem cells (MSCs) appear as a population with debated properties since it has been seen that they can both promote or attenuate tumor progression. For various authors, the main mechanism of interaction of MSCs is through their secretome, the set of molecules secreted into the extracellular milieu, recruiting, and influencing the behavior of other cells in inflammatory environments where they normally reside, such as wounds and tumors. Natural products have been studied as possible cancer treatments, appealing to synergisms between the molecules in their composition; thus, extracts obtained from Petiveria alliacea (Anamu-SC) and Caesalpinia spinosa (P2Et) have been produced and studied previously on different models, showing promising results. The effect of plant extracts on the MSC secretome has been poorly studied, especially in the context of the TME. Here, we studied the effect of Anamu-SC and P2Et extracts in the human adipose-derived MSC (hAMSC)-tumor cell interaction as a TME model. We also investigated the influence of the hAMSC secretome, in combination with these natural products, on tumor cell hallmarks such as viability, clonogenicity, and migration. In addition, hAMSC gene expression and protein synthesis were evaluated for some key factors in tumor progression in the presence of the extracts by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Multiplex, respectively. It was found that the presence of the hAMSC secretome did not affect the cytotoxic or clonogenicity-reducing activities of the natural extracts on cancer cells, and even this secretome can inhibit the migration of these tumor cells, in addition to the fact that the profile of molecules can be modified by natural products. Overall, our findings demonstrate that hAMSC secretome participation in TME interactions can favor the antitumor activities of natural products.

Revisiting the birth of NaCl crystals using molecular dynamics simulation.

Molecular dynamics simulations were used to investigate the initial stage of phase separation mechanisms for an oversaturated electrolytic solution. We developed a low computational cost methodology to determine the simulation frames where the first ionic clusters are formed. By discretizing the simulation box, we obtain a density profile in the moments preceding and succeeding the nuclei's formation. The growth of the clusters identified with our methodology was analyzed until the end of the simulation. Calculation of the Steinhardt parameter showed symmetry of the solid, giving indications that the classical nucleation theory explains the mechanism of the solid formation. The methodology developed was useful for identifying phase separation mechanisms in the nucleation process. At lower concentrations, there was no formation of stable clusters. At intermediate concentrations, the analyses indicate a transition of phases in one stage, from a oversaturate electrolytic solution to a crystalline solid. At high concentration, a transition of phases in two stages, initially, is the formation of a dense liquid, and only after that, crystalline solid formed inside the dense liquid. The change in phase separation mechanism due to increasing oversaturation underscores the importance of precise determination of the driving force for phase separation and concentration limits for each mechanism.

A WC/WO star exploding within an expanding carbon-oxygen-neon nebula.

The final fate of massive stars, and the nature of the compact remnants they leave behind (black holes and neutron stars), are open questions in astrophysics. Many massive stars are stripped of their outer hydrogen envelopes as they evolve. Such Wolf-Rayet stars1 emit strong and rapidly expanding winds with speeds greater than 1,000 kilometres per second. A fraction of this population is also helium-depleted, with spectra dominated by highly ionized emission lines of carbon and oxygen (types WC/WO). Evidence indicates that the most commonly observed supernova explosions that lack hydrogen and helium (types Ib/Ic) cannot result from massive WC/WO stars2,3, leading some to suggest that most such stars collapse directly into black holes without a visible supernova explosion4. Here we report observations of SN 2019hgp, beginning about a day after the explosion. Its short rise time and rapid decline place it among an emerging population of rapidly evolving transients5-8. Spectroscopy reveals a rich set of emission lines indicating that the explosion occurred within a nebula composed of carbon, oxygen and neon. Narrow absorption features show that this material is expanding at high velocities (greater than 1,500 kilometres per second), requiring a compact progenitor. Our observations are consistent with an explosion of a massive WC/WO star, and suggest that massive Wolf-Rayet stars may be the progenitors of some rapidly evolving transients.

A baseline study on the impact of nanoplastics on the portals of entry of xenobiotics in fish.

Mediterranean waters are particularly vulnerable to plastic pollution, with plastic particles concentrations comparable to those found in oceanic gyres. This work aimed to assess the impact of polymethylmethacrylate nanoplastics (PMMA-NPs) on the most important mucosal barriers of the gilthead seabream (Sparus aurata), a highly consumed fish species in the Mediterranean area. Fish were waterborne exposed to NPs (0.001-10 mg/L) for 24 and 96 h, and biochemical parameters associated with oxidative status (total oxidative status and total antioxidant capacity) and immune function (adenosine deaminase, ADA, acetylcholinesterase activity, AChE, and esterase activity, EA) were assessed in gills, intestine, and skin. In intestine, PMMA-NPs led to oxidative status alterations and decreased ADA and EA. In gills, PMMA-NPs induced EA decrease and AChE activity increase. Total protein values were significantly increased in skin. Overall, more alterations were observed in intestine, suggesting it may be one of the most affected tissues by exposure to NPs.

Waterborne exposure of gilthead seabream (Sparus aurata) to polymethylmethacrylate nanoplastics causes effects at cellular and molecular levels.

This study evaluated the effect of a short-term exposure to 45 nm polymethylmethacrylate nanoplastics (PMMA-NPs) on the gilthead seabream (Sparus aurata), by assessing biomarkers at different levels of biological organization in liver and plasma. Fish were exposed via water to PMMA-NPs (0, 0.001, 0.01, 0.1, 1 and 10 mg L-1) and sampled after 24 and 96 h. Results showed a general up-regulation of mRNA levels of key genes associated with lipid metabolism (e.g. apolipoprotein A1 and retinoid X receptor). Together with the modulation of the lipid pathway genes we also found a global increase in cholesterol and triglycerides in plasma. Antioxidant-related genes (e.g. glutathione peroxidase 1) were also up-regulated after 24 h of exposure, but their expression levels returned to control afterwards. Total antioxidant capacity (TAC) was increased throughout the experiment, however at 96 h the antioxidant capacity became less efficient, reflected by an increase in the total oxidative status (TOS). Concomitantly, we found an increase in the erythrocytic nuclear abnormalities (ENAs) throughout the trial. Altogether, PMMA-NPs activated the organism's antioxidant defenses and induced alterations in lipid metabolism pathways and genotoxicity in the blood cells of gilthead seabream.

Effects of single and combined exposures of gold (nano versus ionic form) and gemfibrozil in a liver organ culture of Sparus aurata.

In vitro methods have gained rising importance in ecotoxicology due to ethical concerns. The aim of this study was to assess the single and combined in vitro effects of gold, as nanoparticle (AuNPs) and ionic (Au+) form, and the pharmaceutical gemfibrozil (GEM). Sparus aurata liver organ culture was exposed to gold (4 to 7200 µg·L-1), GEM (1.5 to 15,000 µg·L-1) and combination 80 µg·L-1 gold +150 µg·L-1 GEM for 24 h. Endpoints related with antioxidant status, peroxidative/genetic damage were assessed. AuNPs caused more effects than Au+, increasing catalase and glutathione reductase activities and damaging DNA and cellular membranes. Effects were dependent on AuNPs size, coating and concentration. GEM damaged DNA at an environmentally relevant concentration, 1.5 µg·L-1. Overall, the effects of the combined exposures were higher than the predicted, based on single exposures. This study showed that liver culture can be a useful model to study contaminants effects.

Pulse pressure variability is associated with unfavorable outcomes in acute ischaemic stroke patients treated with intravenous thrombolysis.

BACKGROUND AND PURPOSE: Blood pressure (BP) variability has been associated with worse neurological outcomes in acute ischaemic stroke (AIS) patients receiving treatment with intravenous thrombolysis (IVT). However, no study to date has investigated whether pulse pressure (PP) variability may be a superior indicator of the total cardiovascular risk, as measured by clinical outcomes. METHODS: Pulse pressure variability was calculated from 24-h PP measurements following tissue plasminogen activator bolus in AIS patients enrolled in the Combined Lysis of Thrombus using Ultrasound and Systemic Tissue Plasminogen Activator for Emergent Revascularization (CLOTBUST-ER) trial. The outcomes of interest were the pre-specified efficacy and safety end-points of CLOTBUST-ER. All associations were adjusted for potential confounders in multivariable regression models. RESULTS: Data from 674 participants was analyzed. PP variability was identified as the BP parameter with the most parsimonious fit in multivariable models of all outcomes, and was independently associated (P < 0.001) with lower likelihood of both 24-h neurological improvement and 90-day independent functional outcome. PP variability was also independently related to increased odds of any intracranial bleeding (P = 0.011) and 90-day mortality (P < 0.001). Every 5-mmHg increase in the 24-h PP variability was independently associated with a 36% decrease in the likelihood of 90-day independent functional outcome (adjusted odds ratio 0.64, 95% confidence interval 0.52-0.80) and a 60% increase in the odds of 90-day mortality (adjusted odds ratio 1.60, 95% confidence interval 1.23-2.07). PP variability was not associated with symptomatic intracranial bleeding at either 24 or 36 h after IVT administration. CONCLUSIONS: Increased PP variability appears to be independently associated with adverse short-term and long-term functional outcomes of AIS patients treated with IVT.

Simultaneous absorption of UV-vis and circular dichroism to measure enantiomeric concentrations of praziquantel under nonlinear conditions.

Beer-Lambert-Bouguer law is for a limiting case and, therefore, it is not useful to describe the relationship between absorption signal and enantiomer concentration in a stream when there are nonlinear phenomena present. In this work, the Chiral Detector (CD-2095 JASCO) equipment was used to measure simultaneously the UV-Vis and circular dichroism (CD) signals of a stream with different compositions of praziquantel enantiomers. The tested models were calibrated (parameter estimation) and validated using the Leave-One-Out Cross Validation (LOOCV) method. Both UV-vis and CD signals were absorbed differently in mixtures in comparison to pure solutions, indicating a nonlinear relationship between the absorbed signal and the enantiomer concentration in a mixture stream. Empirical mathematical relationships were tested for each signal (UV-vis and CD) and the pair of equations was evaluated using the Mean Square Error (MSE) metric for each enantiomer concentration (MSEL and MSED) and the pair of equations with the smallest MSEt (=MSEL + MSED) metric was chosen. Confidence interval analysis helped to find even simpler equations in comparison to the chosen ones. Higher nonlinearity was observed for a mixture with low L-PZQ concentration. The developed methodology allowed the choice of an empiric model to give good predictions in a wide range of concentration, what is of utmost importance for monitoring and automatic control purposes, for instance.

Effects of gold nanoparticles in gilthead seabream-A proteomic approach.

Despite the widespread use of nanoparticles (NPs), there are still major gaps of knowledge regarding the impact of nanomaterials in the environment and aquatic animals. The present work aimed to study the effects of 7 and 40 nm gold nanoparticles (AuNPs) - citrate and polyvinylpyrrolidone (PVP) coated - on the liver proteome of the estuarine/marine fish gilthead seabream (Sparus aurata). After 96 h, exposure to AuNP elicited alterations on the abundance of 26 proteins, when compared to the control group. AuNPs differentially affected several metabolic pathways in S. aurata liver cells. Among the affected proteins were those related to cytoskeleton and cell structure, gluconeogenesis, amino acids metabolism and several processes related to protein activity (protein synthesis, catabolism, folding and transport). The increased abundance of proteins associated with energy metabolism (ATP synthase subunit beta), stress response (94 kDa glucose-regulated protein) and cytoskeleton structure (actins and tubulins) may represent the first signs of cellular oxidative stress induced by AuNPs. Although higher gold accumulation was found in the liver of S. aurata exposed to 7 nm PVP-AuNPs, the 7 nm cAuNPs were more bioactive, inducing more effects in liver proteome. Gold accumulated more in the spleen than in the other assessed tissues of S. aurata exposed to AuNPs, highlighting its potential role on the elimination of these NPs.

Biological effects and bioaccumulation of gold in gilthead seabream (Sparus aurata) - Nano versus ionic form.

The question of whether gold (Au) is more toxic as nanoparticles or in its ionic form remains unclear and controversial. The present work aimed to clarify the effects of 96 h exposure to 4, 80 and 1600 µg·L-1 of 7 nm gold nanoparticles (AuNPs) - (citrate coated (cAuNPs) or polyvinylpyrrolidone coated (PVP-AuNPs)) - and ionic Au (iAu) on gilthead seabream (Sparus aurata). Effects at different levels of biological organization (behaviour, neurotransmission, biotransformation, oxidative stress/damage and genotoxicity) were assessed. cAuNPs induced oxidative stress and damage (lipid peroxidation increase), even at 4 µg·L-1, and reduced the ability of S. aurata to swim against a water flow at 1600 µg·L-1. Exposure to cAuNPs induced more adverse effects than exposure to PVP-AuNPs. All tested concentrations of Au (nano or ionic form) induced DNA breaks and cytogenetic damage in erythrocytes of S. aurata. Generally, iAu induced significantly more effects in fish than the nano form, probably associated with the significantly higher accumulation in the fish tissues. No fish mortality was observed following exposure to AuNPs, but mortality was observed in the group exposed to 1600 µg·L-1 of iAu.

Implementation of a Brazilian Cardioprotective Nutritional (BALANCE) Program for improvement on quality of diet and secondary prevention of cardiovascular events: A randomized, multicenter trial

Background Complex percutaneous coronary intervention (PCI) is associated with higher ischemic risk, which can be mitigated by long-term dual antiplatelet therapy (DAPT). However, concomitant high bleeding risk (HBR) may be present, making it unclear whether short- or long-term DAPT should be prioritized. Objectives This study investigated the effects of ischemic (by PCI complexity) and bleeding (by PRECISE-DAPT [PRE dicting bleeding Complications in patients undergoing stent Implantation and Sub sequent Dual Anti Platelet Therapy] score) risks on clinical outcomes and on the impact of DAPT duration after coronary stenting. Methods Complex PCI was defined as ≥3 stents implanted and/or ≥3 lesions treated, bifurcation stenting and/or stent length >60 mm, and/or chronic total occlusion revascularization. Ischemic and bleeding outcomes in high (≥25) or non-high (<25) PRECISE-DAPT strata were evaluated based on randomly allocated duration of DAPT. Results Among 14,963 patients from 8 randomized trials, 3,118 underwent complex PCI and experienced a higher rate of ischemic, but not bleeding, events. Long-term DAPT in non-HBR patients reduced ischemic events in both complex (absolute risk difference: −3.86%; 95% confidence interval: −7.71 to +0.06) and noncomplex PCI strata (absolute risk difference: −1.14%; 95% confidence interval: −2.26 to −0.02), but not among HBR patients, regardless of complex PCI features. The bleeding risk according to the Thrombolysis In Myocardial Infarction scale was increased by long-term DAPT only in HBR patients, regardless of PCI complexity. Conclusions Patients who underwent complex PCI had a higher risk of ischemic events, but benefitted from long-term DAPT only if HBR features were not present. These data suggested that when concordant, bleeding, more than ischemic risk, should inform decision-making on the duration of DAPT. (AU)

Effects and bioaccumulation of gold nanoparticles in the gilthead seabream (Sparus aurata) - Single and combined exposures with gemfibrozil.

Gold nanoparticles (AuNPs) are found in a wide range of applications and therefore expected to present increasing levels in the environment. There is however limited knowledge concerning the potential toxicity of AuNPs as well as their combined effects with other pollutants. Hence, the present study aimed to investigate the effects of AuNPs alone and combined with the pharmaceutical gemfibrozil (GEM) on different biological responses (behaviour, neurotransmission, biotransformation and oxidative stress) in one of the most consumed fish in southern Europe, the seabream Sparus aurata. Fish were exposed for 96 h to waterborne 40 nm AuNPs with two coatings - citrate and polyvinylpyrrolidone (PVP), alone or combined with GEM. Antioxidant defences were induced in liver and gills upon both AuNPs exposure. Decreased swimming performance (1600 µg.L-1) and oxidative damage in gills (4 and 80 µg.L-1) were observed following exposure to polyvinylpyrrolidone coated gold nanoparticles (PVP-AuNPs). Generally, accumulation of gold in fish tissues and deleterious effects in S. aurata were higher for PVP-AuNPs than for cAuNPs exposures. Although AuNPs and GEM combined effects in gills were generally low, in liver, they were higher than the predicted. The accumulation and effects of AuNPs showed to be dependent on the size, coating, surface charge and aggregation/agglomeration state of nanoparticles. Additionally, it was tissue' specific and dependent on the presence of other contaminants. Although, gold intake by humans is expected to not exceed the estimated tolerable daily intake, it is highly recommended to keep it on track due to the increasing use of AuNPs.

Genotoxicity of gold nanoparticles in the gilthead seabream (Sparus aurata) after single exposure and combined with the pharmaceutical gemfibrozil.

Due to their diverse applications, gold nanoparticles (AuNPs) are expected to increase of in the environment, although few studies are available on their mode of action in aquatic organisms. The genotoxicity of AuNPs, alone or combined with the human pharmaceutical gemfibrozil (GEM), an environmental contaminant frequently detected in aquatic systems, including in marine ecosystems, was examined using gilthead seabream erythrocytes as a model system. Fish were exposed for 96 h to 4, 80 and 1600 µg L-1 of 40 nm AuNPs with two coatings - citrate or polyvinylpyrrolidone; GEM (150 µg L-1); and a combination of AuNPs and GEM (80 µg L-1 AuNPs + 150 µg L-1 GEM). AuNPs induced DNA damage and increased nuclear abnormalities levels, with coating showing an important role in the toxicity of AuNPs to fish. The combined exposures of AuNPs and GEM produced an antagonistic response, with observed toxic effects in the mixtures being lower than the predicted. The results raise concern about the safety of AuNPs and demonstrate interactions between them and other contaminants.

Effects of nanoplastics on Mytilus galloprovincialis after individual and combined exposure with carbamazepine.

Plastic pollution is a worldwide problem, highlighted by the fact that plastic materials degrade into nano-size particles (<100 nm), potentially becoming more bioavailable as well as a source of entry of other contaminants into organisms. The present study aimed to assess the effects of polystyrene nanoplastics (PS), individually or combined with carbamazepine (Cbz), on the Mediterranean mussel, Mytilus galloprovincialis. For this purpose, mussels were exposed for 96 h to a concentration range of PS (from 0.05 up to 50 mg L-1), to Cbz (6.3 µg L-1) alone and to the mixture of PS + Cbz (0.05 mg L-1+ 6.3 µg L-1). Molecular and biochemical biomarkers were assessed in the digestive glands, gills and haemolymph. The abundance of mRNA in the digestive glands and gills revealed significant alterations in the expression of genes associated with biotransformation, DNA repair, cell stress-response and innate immunity. Combined exposure of PS + Cbz induced significant downregulation in gene expression (e.g., hsp70) when compared to individual exposure. Total oxidant status increased in digestive glands after exposure to 0.5 mg L-1 PS. Moreover, increased total antioxidant capacity and esterase activity were observed for PS 50 mg L-1, in digestive glands and gills, respectively. The PS induced effects on neurotransmission, measured as inhibition of cholinesterase activity in haemolymph. Genotoxicity was found in haemocytes after exposure to PS, Cbz and their mixture. Moreover, lipid peroxidation was observed for 0.05 mg L-1 PS exposure, showing that nanoplastics can induce oxidative damage. The present study demonstrated that PS, even at low concentrations, led to alterations on the assessed mussels' endpoints.

A multibiomarker approach highlights effects induced by the human pharmaceutical gemfibrozil to gilthead seabream Sparus aurata.

Lipid regulators are among the most prescribed human pharmaceuticals worldwide. Gemfibrozil, which belongs to this class of pharmaceuticals, is one of the most frequently encountered in the aquatic environment. However, there is limited information concerning the mechanisms involved in gemfibrozil effects to aquatic organisms, particularly to marine organisms. Based on this knowledge gap, the current study aimed to assess biochemical and behavioral effects following a sublethal exposure to gemfibrozil (1.5, 15, 150, 1500 and 15,000 µg L-1) in the estuarine/marine fish Sparus aurata. After the exposure to 1.5 µg L-1 of gemfibrozil, fish had reduced ability to swim against a water flow and increased lipid peroxidation in the liver. At concentrations between 15-15,000 µg L-1, the activities of some enzymes involved in antioxidant defense were induced, appearing to be sufficient to prevent oxidative damage. Depending on the organ, different responses to gemfibrozil were displayed, with enzymes like catalase being more stimulated in gills, whereas glutathione peroxidase was more activated in liver. Although there were no obvious concentration-response relationships, the integrated biomarker response version 2 (IBRv2) analysis revealed that the highest concentrations of gemfibrozil (between 150-15,000 µg L-1) caused more alterations. All the tested concentrations of gemfibrozil induced effects in S. aurata, in terms of behavior and/or oxidative stress responses. Oxidative damage was found at a concentration that is considered environmentally relevant, suggesting a potential of this pharmaceutical to impact fish populations.

Genotoxicity of gemfibrozil in the gilthead seabream (Sparus aurata).

Widespread use of pharmaceuticals and suboptimal wastewater treatment have led to increased levels of these substances in aquatic ecosystems. Lipid-lowering drugs such as gemfibrozil, which are among the most abundant human pharmaceuticals in the environment, may have deleterious effects on aquatic organisms. We examined the genotoxicity of gemfibrozil in a fish species, the gilthead seabream (Sparus aurata), which is commercially important in southern Europe. Following 96-h waterborne exposure, molecular (erythrocyte DNA strand breaks) and cytogenetic (micronuclei and other nuclear abnormalities in cells) endpoints were measured. Gemfibrozil was positive in both endpoints, at environmentally relevant concentrations, a result that raises concerns about the potential genotoxic effects of the drug in recipient waters.

Comparing 3d and 2d computational modeling of an oil well blowout using MOHID platform - A case study in the Campos Basin.

The oil well blowout releases hydrocarbons into the marine environment as an oil droplets and gas bubbles dispersion. The oil trajectory is strongly influenced by physical, chemical and biological processes. In general, the ocean oil drift studies are based on a two-dimensional approach, whereas the whole oil from a well blowout can be represented by a surface oil leak in the same geographical coordinates. This work is a case study, where MOHID software is used at the Campos Basin region, in which the Lagrangian results of the surface oil leaks were confronted to their well blowout scenarios in different conditions of depth, seasonality (summer and winter), and use of dispersants at the source of the leak. The research results reinforced the importance of the three-dimensional approach to the scenario of deep and ultra-deep waters, especially for cases in which the dispersant injection into the source of the leak was considered.

Nonlinear model predictive control applied to the separation of praziquantel in simulated moving bed chromatography.

An adaptive nonlinear model predictive control of a simulated moving bed unit for the enantioseparation of praziquantel is presented. A first principle model was applied at the proposed purity control scheme. The main concern about this kind of model in a control framework is in regard to the computational effort to solve it; however, a fast enough solution was achieved. In order to evaluate the controller's performance, several cases were simulated, including external pumps and switching valve malfunctions. The problem of plant-model mismatch was also investigated, and for that reason a parameter estimation step was introduced in the control strategy. In every studied scenario, the controller was able to maintain the purity levels at their set points, which were set to 99% and 98.6% for extract and raffinate, respectively. Additionally, fast responses and smooth actuation were achieved.

Immune-system-dependent anti-tumor activity of a plant-derived polyphenol rich fraction in a melanoma mouse model.

Recent findings suggest that part of the anti-tumor effects of several chemotherapeutic agents require an intact immune system. This is in part due to the induction of immunogenic cell death. We have identified a gallotannin-rich fraction, obtained from Caesalpinia spinosa (P2Et) as an anti-tumor agent in both breast carcinoma and melanoma. Here, we report that P2Et treatment results in activation of caspase 3 and 9, mobilization of cytochrome c and externalization of annexin V in tumor cells, thus suggesting the induction of apoptosis. This was preceded by the onset of autophagy and the expression of immunogenic cell death markers. We further demonstrate that P2Et-treated tumor cells are highly immunogenic in vaccinated mice and induce immune system activation, clearly shown by the generation of interferon gamma (IFN-γ) producing tyrosine-related protein 2 antigen-specific CD8+ T cells. Moreover, the tumor protective effects of P2Et treatment were abolished in immunodeficient mice, and partially lost after CD4 and CD8 depletion, indicating that P2Et's anti-tumor activity is highly dependent on immune system and at least in part of T cells. Altogether, these results support the hypothesis that the gallotannin-rich fraction P2Et's anti-tumor effects are mediated to a great extent by the endogenous immune response following to the exposure to immunogenic dying tumor cells.

Field application of a planted fixed bed reactor (PFR) for support media and rhizosphere investigation using undisturbed samples from full-scale constructed wetlands.

This study presents a novel method for investigations on undisturbed samples from full-scale horizontal subsurface-flow constructed wetlands (HSSFCW). The planted fixed bed reactor (PFR), developed at the Helmholtz Center for Environmental Research (UFZ), is a universal test unit for planted soil filters that reproduces the operational conditions of a constructed wetland (CW) system in laboratory scale. The present research proposes modifications on the PFR original configuration in order to allow its operation in field conditions. A mobile device to obtain undisturbed samples from real-scale HSSFCW was also developed. The experimental setting is presented with two possible operational configurations. The first allows the removal and replacement of undisturbed samples in the CW bed for laboratory investigations, guaranteeing sample integrity with a mobile device. The second allows the continuous operation of the PFR and undisturbed samples as a fraction of the support media, reproducing the same environmental conditions outside the real-scale system. Investigations on the hydrodynamics of the adapted PFR were carried out with saline tracer tests, validating the proposed adaptation. Six adapted PFR units were installed next to full-scale HSSFCW beds and fed with interstitial liquid pumped from two regions of planted and unplanted support media. Fourteen points were monitored along the system, covering carbon fractions, nitrogen and sulfate. The results indicate the method as a promising tool for investigations on CW support media, rhizosphere and open space for studies on CW modeling, respirometry, kinetic parameters, microbial communities, redox potential and plant influence on HSSFCW.