Dioxin-like POPs in national samples from global monitoring plan projects (2017-2019).

The global monitoring plan (GMP) established under the Stockholm Convention on Persistent Organic Pollutants (POPs) had defined ambient air, human milk or blood, and water as core matrices to be analyzed and assessed for spatial and temporal distribution. Within projects coordinated by the United Nations Environment Programme (UNEP), developing countries were offered to have other matrices analyzed for dioxin-like POPs (dl-POPs) in experienced laboratories. Subsequently, 185 samples from 27 countries located in Africa, Asia, and Latin America were collected during 2018-2019 and analyzed for polychlorinated dibenzodioxins (PCDD), dibenzofurans (PCDF), and biphenyls (PCB). Using the WHO2005 toxic equivalency approach (TEQ), the amounts of dl-POPs found were low (<1 pg TEQ/g); however, singular samples had higher values; e.g., egg from Morocco, fish from Argentina or Tunisia; soil and sediment samples. Results showed that the matrix, abiotic or biota, had more impact on the TEQ pattern than the geographic location. Independent of the location and across all samples, dl-PCB in (shell)fish and beef samples had a contribution of 75% to the total TEQ; milk (63%), chicken (52%), and butter (50.2%) more than 50%. Sediment (57% and 32%) and soil (40% and 36%)) samples were dominated by PCDD and PCDF, respectively; therein, dl-PCB had shares of 11% and 24%. Egg samples (N = 27) did not follow the general biota pattern and had 21% of the TEQ from the PCDD, 45% from PCDF, and 34% from dl-PCB; thus, indicating that abiotic matrices such as soil or other material may have an impact.

Validating EEG, MEG and Combined MEG and EEG Beamforming for an Estimation of the Epileptogenic Zone in Focal Cortical Dysplasia.

MEG and EEG source analysis is frequently used for the presurgical evaluation of pharmacoresistant epilepsy patients. The source localization of the epileptogenic zone depends, among other aspects, on the selected inverse and forward approaches and their respective parameter choices. In this validation study, we compare the standard dipole scanning method with two beamformer approaches for the inverse problem, and we investigate the influence of the covariance estimation method and the strength of regularization on the localization performance for EEG, MEG, and combined EEG and MEG. For forward modelling, we investigate the difference between calibrated six-compartment and standard three-compartment head modelling. In a retrospective study, two patients with focal epilepsy due to focal cortical dysplasia type IIb and seizure freedom following lesionectomy or radiofrequency-guided thermocoagulation (RFTC) used the distance of the localization of interictal epileptic spikes to the resection cavity resp. RFTC lesion as reference for good localization. We found that beamformer localization can be sensitive to the choice of the regularization parameter, which has to be individually optimized. Estimation of the covariance matrix with averaged spike data yielded more robust results across the modalities. MEG was the dominant modality and provided a good localization in one case, while it was EEG for the other. When combining the modalities, the good results of the dominant modality were mostly not spoiled by the weaker modality. For appropriate regularization parameter choices, the beamformer localized better than the standard dipole scan. Compared to the importance of an appropriate regularization, the sensitivity of the localization to the head modelling was smaller, due to similar skull conductivity modelling and the fixed source space without orientation constraint.

Reconstructing subcortical and cortical somatosensory activity via the RAMUS inverse source analysis technique using median nerve SEP data.

This study concerns reconstructing brain activity at various depths based on non-invasive EEG (electroencephalography) scalp measurements. We aimed at demonstrating the potential of the RAMUS (randomized multiresolution scanning) technique in localizing weakly distinguishable far-field sources in combination with coinciding cortical activity. As we have shown earlier theoretically and through simulations, RAMUS is a novel mathematical method that by employing the multigrid concept, allows marginalizing noise and depth bias effects and thus enables the recovery of both cortical and subcortical brain activity. To show this capability with experimental data, we examined the 14-30 ms post-stimulus somatosensory evoked potential (SEP) responses of human median nerve stimulation in three healthy adult subjects. We aim at reconstructing the different response components by evaluating a RAMUS-based estimate for the primary current density in the nervous tissue. We present source reconstructions obtained with RAMUS and compare them with the literature knowledge of the SEP components and the outcome of the unit-noise gain beamformer (UGNB) and standardized low-resolution brain electromagnetic tomography (sLORETA). We also analyzed the effect of the iterative alternating sequential technique, the optimization technique of RAMUS, compared to the classical minimum norm estimation (MNE) technique. Matching with our previous numerical studies, the current results suggest that RAMUS could have the potential to enhance the detection of simultaneous deep and cortical components and the distinction between the evoked sulcal and gyral activity.

Long-term trends of airborne halogenated flame retardants (HFRs) by means of tree leaf and shoot analyses.

The historical air pollution with halogenated flame retardants (HFRs) in Germany was assessed by investigating tree leaf and shoot samples which have been archived in the German environmental specimen bank. Samples covered the period from 1985 to 2016. 43 HFRs comprising polybrominated diphenyl ethers as well as emerging brominated and chlorinated compounds such as Dechlorane Plus, DBDPE, or DPTE, were analysed in 115 samples from ten sub sites originating from six areas characterised by different land uses, including urban as well as a background site. HFRs were observed in each sample showing the widespread distribution of HFRs in Germany in tree leaves and shoots as bioindicators of past and present atmospheric pollution. Analytes observed at elevated concentrations were BDE 209, DBDPE and DPTE. Observed HFR-levels differed between analytes as well as sampling locations, particularly prior to the year 2000. They were typically highest at conurbation areas. Concentrations at the background site often belonged to the lowest ones observed, however, lowest values were not exclusively found there. The quantification frequencies appeared to decrease from the past to most recent samples. With few exceptions, atmospheric pollution of both, legacy and emerging HFRs, decreased significantly.

Does interprofessional team-training affect nurses' and physicians' perceptions of safety culture and communication practices? Results of a pre-post survey study.

BACKGROUND: Many hospitals seek to increase patient safety through interprofessional team-trainings. Accordingly, these trainings aim to strengthen important key aspects such as safety culture and communication. This study was designed to investigate if an interprofessional team-training, administered to a relatively small group of nurses and physicians would promote a change in healthcare professionals' perceptions on safety culture and communication practices throughout the hospital. We further sought to understand which safety culture aspects foster the transfer of trained communication practices into clinical practice. METHODS: We conducted a pre-post survey study using six scales to measure participants' perceptions of safety culture and communication practices. Mean values were compared according to profession and participation in training. Using multiple regression models, the relationship between safety culture and communication practices was determined. RESULTS: Before and after the training, we found high mean values for all scales. A significant, positive effect was found for the communication practices of the physicians. Participation in the training sessions played a variably relevant role in the communication practices. In addition, the multiple regression analyses showed that specific safety culture aspects have a cross-professional influence on communication practices in the hospital. CONCLUSIONS: This study suggest that interprofessional team-trainings of a small group of professionals can successfully be transferred into clinical practice and indicates the importance of safety culture aspects for such transfer processes. Thus, we recommend the consideration of safety culture aspects before starting a training intervention.

Recent findings of halogenated flame retardants (HFR) in the German and Polar environment.

To get an overview about distribution, levels and temporal trends of polybrominated diphenyl ethers (PBDE) and halogenated flame retardants (HFR) of emerging concern, different types of environmental samples archived in the German Environment Specimen Bank as well as fish filet samples from the Arctic (n = 13) and Antarctica (n = 5) were analysed for 43 substances (24 PBDE, 19 HFR) using a multi-column clean-up and GC-API-MS/MS or GC-MS. Sample types were herring gull egg (n = 3), blue mussel (n = 3) and eelpout filet (n = 3) from the German North- and Baltic Sea, bream filet (n = 7), zebra mussel (n = 6) and suspended particulate matter (SPM, n = 7) from German freshwater ecosystems as well as tree leaves (n = 9)/shoots (n = 10), soil (n = 4), earthworm (n = 4) and deer liver (n = 7) as representatives of German terrestrial ecosystems. PBDE and emerging HFR were present in each investigated matrices from Germany and Polar regions showing their widespread distribution. The presence in Arctic and Antarctic fish samples confirms their long-range transport potential. Average concentrations of total emerging HFR were highest in SPM (26 ng g-1 dry weight (dw)), zebra mussel (10 ng g-1 dw) and herring gull egg (2.6 ng g-1 dw). Lowest levels were measured in fish filet samples from Antarctica (0.02 ng g-1 dw). Average total PBDE concentrations were highest in bream filet (154 ng g-1), herring gull egg (61 ng g-1 dw), SPM (21 ng g-1 dw), and zebra mussel 18 (ng g-1) and lowest in deer liver (0.04 ng g-1 dw). The patterns of non-fauna terrestrial samples (leaves, shoots, soil) as well as SPM were dominated by DBDPE and BDE209. Elevated proportions of DPTE and in most cases the absence of DBDPE characterized all fauna samples with the exception of Polar samples. Overall, emerging HFR appeared to be less bioaccumulative than PBDE. Temporal trends were generally decreasing with few exceptions such as DBDPE.

Halogenated flame retardants in tree samples applied as bioindicators for atmospheric pollution.

Coniferous shoots and deciduous tree leaf samples from 10 sites in Germany were taken in 2015 or 2016 within the German Environmental Specimen Bank sampling program and analysed for 24 polybrominated biphenyl ethers (PBDEs) and 19 additional halogenated flame retardants (HFRs). At one site, additional historic samples dating back till 2003 were also investigated. Samples were Soxhlet-extracted, cleaned-up by a non-destructive multi-step procedure involving gel permeation chromatography, and detected by GC-API-MS/MS as well as GC-MS. Besides PBDEs as classical HFRs, emerging HFRs such as Dechlorane Plus, DPTE, DBDPE, or ATE were region-wide observed demonstrating their widespread occurrence in the atmosphere. Highest concentrations in recent samples were found for DBDPE (<230-2760 pg g-1 dry weight (dw)) followed by DPTE (91-1540 pg g-1 dw), BDE209 (<156-461 pg g-1 dw), and BDE47 (<27-505 pg g-1 dw) or DP (31-122 pg g-1 dw). The overall uniform and widespread distribution as well as similar HFR levels and composition profiles observed in recent conifer shoots and corresponding deciduous tree leaves from the same area indicate a prolonged medium to long-range transport as sources. Furthermore, it is demonstrated that both tree types are generally suitable bioindicators for atmospheric pollution with HFRs, although accumulation may vary depending on HFR properties and accumulation period. The historic samples showed decreasing PBDE levels whereas no clear trend could be observed for other investigated HFRs at this site.

Determination of halogenated flame retardants by GC-API-MS/MS and GC-EI-MS: a multi-compound multi-matrix method.

The extensive application of halogenated flame retardants has led to their widespread distribution in the environment. Recently, concerns emerged regarding their potential persistence, (bio)accumulation, and/or toxicity. Particularly halogenated flame retardants based on norbornene structures, like Dechlorane Plus as well as other brominated PBDE replacements, generically called emerging, novel, or alternative flame retardants, are in the focus of interest. A comprehensive analytical method for the determination of 21 halogenated flame retardants (HFRs) of different substance classes (dechloranes, brominated aromates, brominated ethers, cyclic BFR) in a broad variety of matrices (tree leaves, fish fillet, birds eggs, suspended particles) was developed in order to assess their environmental levels as well as temporal trends, especially for the use within environmental specimen banks (ESBs). In addition to the alternative HFRs, a set of 24 PBDEs were measured in the same samples, however using GC-EI-MS for detection. Samples were extracted using accelerated solvent extraction (ASE) with dichloromethane:hexane (exception: soxhlet extraction for suspended particles) followed by a multi column clean-up. Quantification was performed by API-GC-MS/MS as a modern, gentle, and sensitive technique for simultaneous detection of compounds throughout a wide range of masses and fragmentation characteristics (exception: PBDE detection using GC-EI-MS). With the exception of BDE 209, instrumental precisions of target compounds ranged from 1% to 16 % (at levels of 2 pg injection-1 for HFR, 20 pg injection-1 for DBDPE, 7-36 pg injection-1 for PBDEs). Interday precisions of the entire analytical method including extraction and clean-up were mostly below 25% for all validation matrices at spiked levels of 100 pg sample-1 for HFR (DBDPE: 1000 pg sample-1) and 1200-6000 pg sample-1 for PBDEs. The majority of analytes were investigated with expanded measurement uncertainties of less than 50%. Graphical abstract A new approach to HFR analysis in multiple environmental matrices.

The Effect of Head Model Simplification on Beamformer Source Localization.

Beamformers are a widely-used tool in brain analysis with magnetoencephalography (MEG) and electroencephalography (EEG). For the construction of the beamformer filters realistic head volume conductor modeling is necessary for accurately computing the EEG and MEG leadfields, i.e., for solving the EEG and MEG forward problem. In this work, we investigate the influence of including realistic head tissue compartments into a finite element method (FEM) model on the beamformer's localization ability. Specifically, we investigate the effect of including cerebrospinal fluid, gray matter, and white matter distinction, as well as segmenting the skull bone into compacta and spongiosa, and modeling white matter anisotropy. We simulate an interictal epileptic measurement with white sensor noise. Beamformer filters are constructed with unit gain, unit array gain, and unit noise gain constraint. Beamformer source positions are determined by evaluating power and excess sample kurtosis (g2) of the source-waveforms at all source space nodes. For both modalities, we see a strong effect of modeling the cerebrospinal fluid and white and gray matter. Depending on the source position, both effects can each be in the magnitude of centimeters, rendering their modeling necessary for successful localization. Precise skull modeling mainly effected the EEG up to a few millimeters, while both modalities could profit from modeling white matter anisotropy to a smaller extent of 5-10 mm. The unit noise gain or neural activity index beamformer behaves similarly to the array gain beamformer when noise strength is sufficiently high. Variance localization seems more robust against modeling errors than kurtosis.

Screening of organic and metal contaminants in Australian humpback dolphins (Sousa sahulensis) inhabiting an urbanised embayment.

As a marine mammal species that inhabits shallow nearshore waters, humpback dolphins are likely exposed to a wide range of pollutants from adjacent land-based activities. Increased mortality rates of Australian humpback dolphins (Sousa sahulensis) in waters off a major urbanised centre triggered investigations into the threats to these species, including their contaminant exposure. The present study utilised archived tissues from 6 stranded animals to screen for a range of pollutants (PCDD/Fs, PBDEs, PCBs, organochlorine pesticides, PAHs, organotins, essential and non-essential elements) to inform future biopsy based biomonitoring strategies. Concentrations of PCBs and DDXs in blubber of some of these animals were remarkably high, at levels near or above toxicological thresholds associated with immune- and reproductive toxicity or population declines in other marine mammals. PBDEs, PAHs, HCB, organotins, 'drins' as well as other organic pesticides were not detected, or present at relatively low concentrations. Profiles of elements were similar in epidermis compared to other tissues, and apart from some exceptions (e.g. Fe, Cr, Co, Cu) their concentrations fell within 25th-75th percentiles of cetacean baselines in four of the five animals. Non-essential elements (Al, V, Pb, Ba, Ni, Cd) were notably elevated in one specimen which may have experienced poor health or nutritional status. These data provide a first insight into the contaminant status of a rare and poorly studied population inhabiting an urbanised area. The results highlight a need for future biomonitoring of live populations, and inform on priorities in the typically limited blubber and skin sample volumes obtained through biopsies.

Contamination levels and congener distribution of PCDDs, PCDFs and dioxin-like PCBs in buffalo's milk from Caserta province (Italy).

An extraordinary plan of official control was carried out in 2008 in Campania (Italy) with the aim to monitor polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs) levels in buffalo milk and to detect the contaminated farms, most of which are located in Caserta province. For these companies has been ordered seizure and execution of additional analyses has been requested in farms falling in the nearness, within a distance of 3km, for a total of 304 farms examined. Moreover, all non-compliant farms were subjected to a periodic sampling in order to monitor trends in the levels of contamination. In this paper the distribution and the concentrations of 17 PCDD/Fs and 12 dioxin-like PCBs in 460 samples of buffalo milk collected in the province of Caserta (Italy) are presented. The range of WHO-TEQ values for the PCDD/Fs in milk was 0.17pgTEQg(-1)fat and 87.0pgTEQg(-1)fat with a mean value 3.63pgTEQg(-1)fat and medium value 2.25pgTEQg(-1)fat. The concentrations of dioxin-like PCBs in the analysed samples ranged from 0.21pgTEQg(-1)fat to 15.9pgTEQg(-1)fat and the WHO-TEQ values of sum of PCDDs, PCDFs and dl-PCBs ranged from 0.45pgTEQg(-1)fat to 103.0pgTEQg(-1)fat. The geo-referencing analysis allowed to individuate a restricted area of the region object of the present study where is located the majority of the non-compliant farms. The study of the congeners distribution has finally suggested that the likely cause of contamination is to be attributed to the illegal burning of waste.

Modulation of extracellular monoamine transmitter concentrations in the hippocampus after weak and strong tetanization of the perforant path in freely moving rats.

Hippocampal long-term potentiation (LTP) is considered as a cellular model of memory formation. Specific, electrical weak tetanization of distinct afferents such as the medial perforant path results in a short-lasting, protein synthesis-independent early-LTP (up to 4 h) within the dentate gyrus. A stronger tetanization leads to late-LTP (>4 h), which is protein synthesis-dependent and requires heterosynaptic activation during its induction, the latter of which can be provided by afferents from cortical brain regions or subcortical nuclei during memory formation in the behaving animal. In particular, noradrenaline (NA) is required for late-LTP in the dentate gyrus and dopamine for late-LTP in the apical CA1-dendrites. However, little is known about the concentrations and temporal dynamics of such neuromodulators like NA, serotonin (5-HT) and dopamine (DA) during LTP. We now implemented the microdialysis method to study this topic after stimulating the dentate gyrus in more detail. A weak tetanus of the perforant path, which normally leads to early-LTP, transiently but significantly decreased the concentration of NA (3 h) and increased the concentration of 5-HT (about 2 h) and DA (about 1 h) in the hippocampus. A strong tetanus, normally resulting in late-LTP, increased concentrations of NA and DA significantly and long-lasting (for about 5 h), whereas 5-HT concentration was increased with a delay (after about 30 min) and only for a short time (30 min). Thus different stimulation protocols resulted in different release patterns of neuromodulators, that may support discriminative processing of incoming information in the hippocampus.

Extracorporeal photopheresis with permanent subcutaneous right atrial catheters.

BACKGROUND: Adequate peripheral venous access is crucial for successful extracorporeal photopheresis (ECP). As this approach is not always feasible in older patients and patients with graft-versus-host disease, central venous catheters play an increasing role in providing long-term vascular access for ECP.However, not all catheters are able to deliver the minimum flow rate of 7 ml/min for ECP. PATIENTS AND METHODS: Eight different permanent subcutaneous right atrial catheters were connected in vitro to the UVAR-XTS photopheresis system and median flow rates were determined. In addition, in vivo flow rates of patients who received ECP, using either peripheral or central venous access, were determined. RESULTS: Hemodialysis catheters with an internal diameter of 2.0 or 1.5 x 3.5 mm and a length up to 48 cm provided in vitro flow rates of 27-28 ml/min, almost identical to a peripheral access needle. Central venous catheters with a length of over 90 cm reached flow rates below 7 ml/min and are impractical for ECP. The analysis of 308 ECP collection cycles with peripheral vascular access revealed an average flow rate of 31.5 +/- 6.4 ml/min. Only permanent subcutaneous right atrial catheters made for hemodialysis provided similar flow rates (Quinton PermCath Dual Lumen) (33.7 +/- 4.7 ml/min, n = 198). CONCLUSIONS: Permanent subcutaneous hemodialysis catheters with a length of maximally 48 cm achieve optimal flow rates for ECP. They represent therefore the central venous access of choice in patients with inadequate peripheral vascular access.