Publications by authors named "Weyers A"

Mixture Assessment Factors (MAFs) have been proposed in the European Union (EU) as a rapid and simple way of protecting aquatic organisms from the combined effects of unintentional chemical mixtures when regulating industrial chemicals under the REACH (EU Regulation on the registration, evaluation, authorisation, and restriction of chemicals) program. A wide range of values has been suggested for the MAF including values of 20 or larger. In this paper we performed a series of case studies using composition data from 46,546 mixtures reported in three surveys of chemicals in EU surface waters.

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To characterize the potential for exposure of amphibian terrestrial life stages to plant protection products (PPP), we studied the occurrence and habitat use of adult and metamorph common frogs (Rana temporaria) and common toads (Bufo bufo) in an agricultural landscape in Germany. The four selected study sites were breeding ponds with approximately 80% agricultural land within a 1-km radius. Adults were monitored by radio tracking for two years, and metamorph numbers were assessed for one summer using pitfall traps alongside drift fences.

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Background: Postpartum hemorrhage is a significant cause of both maternal morbidity and mortality worldwide and is increasing in incidence. This study aimed to assess improvement and identify shortcomings in trainee performance in different simulation systems in the management of postpartum hemorrhage.

Objective: To perform a pilot study evaluating and comparing high- and low-fidelity simulation models, assessing improvement in repeated performance with high-fidelity mode and identifying mistakes made assessed using Objective Structured Assessment of Technical Skills and thereby exploring what aspects of emergency management of postpartum hemorrhage should be prioritized in teaching settings and assessing what simulation setup is most effective in achieving competence.

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The toxicity and ecotoxicity of pesticide active ingredients are evaluated by a number of standardized test methods using vertebrate animals. These standard test methods are required under various regulatory programs for the registration of pesticides. Over the past two decades, additional test methods have been developed with endpoints that are responsive to endocrine activity and subsequent adverse effects.

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Water bodies located in anthropogenically influenced environments, such as agricultural landscapes, may be exposed to different chemicals simultaneously or sequentially. Yet, current environmental risk assessments focus on single active substances for unintended mixtures. For 3.

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Understanding the frequency of non-additive effects of pesticides (synergism and antagonism) is important in the context of risk assessment. The goal of this study was to investigate the prevalence of non-additive effects of pesticides to honey bees (Apis mellifera). We investigated a large set of mixtures including insecticides and fungicides of different chemical modes of action and classes.

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Unintentional environmental mixtures happen when multiple chemicals co-occur in the environment. A generic mixture assessment factor (MAF), has been proposed to account for this. The MAF is a number by which safe exposure levels for single chemicals are divided to ensure protection against combined exposures to multiple chemicals.

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Wild birds and mammals that feed in agricultural habitats are potentially exposed to pesticides through various routes. The European Food Safety Authority (EFSA) recently published a statement which concluded that the current EFSA risk assessment scheme for birds and mammals does not adequately cover bats (Chiroptera). In the present study, we take a more detailed look at the EFSA statement and assumptions made regarding direct (dermal) and indirect (dietary) exposure of bats to pesticides in terms of their realism and the potential implications for risk assessment outcomes.

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Purpose: The presented in-vitro study provides a comparison of various catheters for mechanical treatment of large-burden pulmonary embolism (PE) under standardized conditions, using a new test rig. Dedicated aspiration catheters (JETi®, Penumbra Indigo®, Aspirex®) were compared with standard catheters (Pigtail, Multi-Purpose, Balloon Catheter) applied for embolus fragmentation.

Materials And Methods: Emboli prepared from porcine blood were washed into the test rig which consists of anatomical models of the pulmonary artery (PA) and of the right heart in combination with a pulsatile drive system.

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Wild birds and mammals that feed in agricultural habitats are potentially exposed to pesticides through various routes. Until recently, it has been implicitly assumed that the existing European Union risk assessment scheme for birds and mammals also covered bats (Chiroptera). However, recent publications raised concerns and, in 2019, a scientific statement was published by the European Food Safety Authority (EFSA) that concluded that bats were not adequately covered by the current risk assessment scheme.

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CD4 T cells enable the critical B cell humoral immune protection afforded by most effective vaccines. We and others have recently identified an alternative source of help for B cells in mice, invariant NK T (iNKT) cells. iNKT cells are innate glycolipid-specific T cells restricted to the nonpolymorphic Ag-presenting molecule CD1d.

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Recent regulatory testing programs have been designed to evaluate whether a chemical has the potential to interact with the endocrine system and could cause adverse effects. Some endocrine pathways are highly conserved among vertebrates, providing a potential to extrapolate data generated for one vertebrate taxonomic group to others (i.e.

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Background: Stigmatization and overall scarcity of psychiatrists and other mental health-care professionals remain a huge public health challenge in low- and middle-income countries, more specifically in India. Most patients seek help from faith healers, and awareness about psychiatrists and treatment methods is often lacking. Our study aims to explore public attitudes toward psychiatrists and psychiatric medication in five Indian metropolitan cities and to identify factors that could influence these attitudes.

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Objective: It is widely accepted that the presence of a glycosaminoglycan-rich glycocalyx is essential for endothelialized vasculature health; in fact, a damaged or impaired glycocalyx has been demonstrated in many vascular diseases. Currently, there are no methods that characterize glycocalyx functionality, thus limiting investigators' ability to assess the role of the glycocalyx in vascular health.

Approach And Results: We have developed novel, easy-to-use, in vitro assays that directly quantify live endothelialized surface's functional heparin weights and their anticoagulant capacity to inactivate Factor Xa and thrombin.

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Fate and toxicity of the active ingredients (AI's) of plant protection products in surface waters is often influenced by pH. Although a general range of pH values is reported in literature, an evaluation targeting aquatic ecosystems with documented AI inputs is lacking at the larger scale. Results show 95% of European surface waters (n = 3075) with a documented history of AI exposure fall within a rather narrow pH range, between 7.

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A novel method enabling the engineering of a dense and appropriately oriented heparin-containing layer on decellularized aortas has been developed. Amino groups of decellularized aortas were first modified to azido groups using 3-azidobenzoic acid. Azide-clickable dendrons were attached onto the azido groups through "alkyne-azide" click chemistry, affording a tenfold amplification of adhesions sites.

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Glycans play a critical role in physiological and pathological processes through interaction with a variety of ligands. Altered expression and dysregulation of these molecules can cause aberrant cellular function such as malignancy. Glycomics provide information of the structure and function of glycans, glycolipids, and glycoproteins such as proteoglycans, and may help to predict cancer development and progression as biomarkers.

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Glycosaminoglycans (GAGS) are anionic, linear, polysaccharides involved in cell signaling. The GAG content, composition and structure of human tissue have been suggested to play a role in cancer and might provide useful diagnostic or prognostic markers. The current study examines 17 stomach tissue biopsy samples taken from normal individuals and from patients with gastric cancers.

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To use and implement an assessment scheme for the evaluation of endocrine disrupting properties of chemicals in ecotoxicology, the types of effect need to be agreed. Effects that merit further consideration in this context should fulfil the following three criteria: caused by an endocrine mode of action, be adverse, and be relevant at the population level to reflect the protection goal of ecotoxicological assessments. Thereafter, a comparison of effect values, regardless of the causative mechanisms, should be made, firstly to determine if endocrine toxicity generates the lowest endpoint within a taxon, and secondly if it is the lowest endpoint compared to that of other taxa living in the same compartment.

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Keratan sulfate (KS) is an important glycosaminoglycan that is found in cartilage, reproductive tissues, and neural tissues. Corneal KS glycosaminoglycan is found N-linked to lumican, keratocan and mimecan proteoglycans, and has been widely studied by investigators interested in corneal development and diseases. Recently, the availability of corneal KS has become severely limited, owing to restrictions on the shipment of bovine central nervous system byproducts across international borders in an effort to prevent additional cases of mad cow disease.

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Proteoglycans, comprised of a core protein to which glycosaminoglycan chains are covalently linked, are an important structural and functional family of macromolecules found in the extracellular matrix. Advances in our understanding of biological interactions have lead to a greater appreciation for the need to design tissue engineering scaffolds that incorporate mimetics of key extracellular matrix components. A variety of synthetic and semisynthetic molecules and polymers have been examined by tissue engineers that serve as structural, chemical and biological replacements for proteoglycans.

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Capillary electrophoresis is a common technique used for glycosaminoglycan-derived disaccharide analysis because of its high resolving power, high separation efficiency, high sensitivity, short analysis time, and straightforward operation. CE coupled to laser-induced fluorescence (LIF) detection shows an approximately 100 times higher sensitivity than traditional UV detection at 232 nm. 2-Aminoacridone (AMAC) is a widely used fluorophore for labeling unsaturated disaccharides by deductive amination, which is one of the most important method of derivatization of disaccharides for CE-LIF detection.

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The European regulation on plant protection products (1107/2009) (EC, 2009a), the revisions to the biocides Directive (COM[2009]267) (EC, 2009b), and the regulation concerning chemicals (Regulation (EC) No. 1907/2006 'REACH') (EC.2006) only support the marketing and use of chemical products on the basis that they do not induce endocrine disruption in humans or wildlife species.

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Cancer is one of the leading noncommunicable diseases that vastly impacts both developed and developing countries. Truly innovative diagnostics that inform disease susceptibility, prognosis, and/or response to treatment (theragnostics) are seriously needed for global public health and personalized medicine for patients with cancer. This study examined the structure and content of glycosaminoglycans (GAGs) in lethal and nonlethal breast cancer tissues from six patients.

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Glycosaminoglycans are a family of polysaccharides widely distributed in all eukaryotic cells. These polyanionic, linear chain polysaccharides are composed of repeating disaccharide units that are often differentially substituted with sulfo groups. The diversity of glycosaminoglycan structures in cells, tissues and among different organisms reflect their functional an evolutionary importance.

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