Racial differences in bumetanide-sensitive cotransport and N-ethylmaleimide-stimulated potassium efflux

Racial differences in erythrocyte potassium effluxes mediated by two loop-diuretic sensitive modes of cotransport were compared. In red cells loaded to contain approximately equimolar amounts of sodium and potassium, black subjects had lower bumetanide-sensitive sodium-dependent net potassium effluxes as compared to whites. In fresh, washed erythrocytes pretreated with N-ethylmaleimide (NEM), maximal net potassium efflux was greater in blacks than in whites. NEM-stimulated potassium efflux was partially inhibited by bumetanide but only at very high concentrations. The quantitative differences in these two modes of potassium efflux suggest that NEM-stimulated potassium efflux is not an altered mode of sodium-dependent potassium efflux.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25667/1/0000219.pd

Towards a population synthesis of discs and planets. II. Confronting disc models and observations at the population level

Aims. We want to find the distribution of initial conditions that best reproduces disc observations at the population level. Methods. We first ran a parameter study using a 1D model that includes the viscous evolution of a gas disc, dust, and pebbles, coupled with an emission model to compute the millimetre flux observable with ALMA. This was used to train a machine learning surrogate model that can compute the relevant quantity for comparison with observations in seconds. This surrogate model was used to perform parameter studies and synthetic disc populations. Results. Performing a parameter study, we find that internal photoevaporation leads to a lower dependency of disc lifetime on stellar mass than external photoevaporation. This dependence should be investigated in the future. Performing population synthesis, we find that under the combined losses of internal and external photoevaporation, discs are too short lived. Conclusions. To match observational constraints, future models of disc evolution need to include one or a combination of the following processes: infall of material to replenish the discs, shielding of the disc from internal photoevaporation due to magnetically driven disc winds, and extinction of external high-energy radiation. Nevertheless, disc properties in low-external-photoevaporation regions can be reproduced by having more massive and compact discs. Here, the optimum values of the $\alpha$ viscosity parameter lie between $3\times10^{-4}$ and $10^{-3}$ and with internal photoevaporation being the main mode of disc dispersal.Comment: Accepted for publication in A&A; minor changes in the reference lis

Emergence of nanoplastic in the environment and possible impact on human health

On account of environmental concerns, the fate and adverse effects of plastics have attracted considerable interest in the past few years. Recent studies have indicated the potential for fragmentation of plastic materials into nanoparticles, i.e., “nanoplastics,” and their possible accumulation in the environment. Nanoparticles can show markedly different chemical and physical properties than their bulk material form. Therefore possible risks and hazards to the environment need to be considered and addressed. However, the fate and effect of nanoplastics in the (aquatic) environment has so far been little explored. In this review, we aim to provide an overview of the literature on this emerging topic, with an emphasis on the reported impacts of nanoplastics on human health, including the challenges involved in detecting plastics in a biological environment. We first discuss the possible sources of nanoplastics and their fates and effects in the environment and then describe the possible entry routes of these particles into the human body, as well as their uptake mechanisms at the cellular level. Since the potential risks of environmental nanoplastics to humans have not yet been extensively studied, we focus on studies demonstrating cell responses induced by polystyrene nanoparticles. In particular, the influence of particle size and surface chemistry are discussed, in order to understand the possible risks of nanoplastics for humans and provide recommendations for future studies

Investigating the interaction of cellulose nanofibers derived from cotton with a sophisticated 3D human lung cell coculture

Cellulose nanofibers are an attractive component of a broad range of nanomaterials. Their intriguing mechanical properties and low cost, as well as the renewable nature of cellulose make them an appealing alternative to carbon nanotubes (CNTs), which may pose a considerable health risk when inhaled. Little is known, however, concerning the potential toxicity of aerosolized cellulose nanofibers. Using a 3D in vitro triple cell coculture model of the human epithelial airway barrier, it was observed that cellulose nanofibers isolated from cotton (CCN) elicited a significantly (p < 0.05) lower cytotoxicity and (pro-)inflammatory response than multiwalled CNTs (MWCNTs) and crocidolite asbestos fibers (CAFs). Electron tomography analysis also revealed that the intracellular localization of CCNs is different from that of both MWCNTs and CAFs, indicating fundamental differences between each different nanofibre type in their interaction with the human lung cell coculture. Thus, the data shown in the present study highlights that not only the length and stiffness determine the potential detrimental (biological) effects of any nanofiber, but that the material used can significantly affect nanofiber–cell interactions

Comparative Mutant Analysis of Arabidopsis ABCC-Type ABC Transporters: AtMRP2 Contributes to Detoxification, Vacuolar Organic Anion Transport and Chlorophyll Degradation

The enormous metabolic plasticity of plants allows detoxification of many harmful compounds that are generated during biosynthetic processes or are present as biotic or abiotic toxins in their environment. Derivatives of toxic compounds such as glutathione conjugates are moved into the central vacuole via ATP-binding cassette (ABC)-type transporters of the multidrug resistance-associated protein (MRP) subfamily. The Arabidopsis genome contains 15 AtMRP isogenes, four of which (AtMRP1, 2, 11 and 12) cluster together in one of two major phylogenetic clades. We isolated T-DNA knockout alleles in all four highly homologous AtMRP genes of this clade and subjected them to physiological analysis to assess the function of each AtMRP of this group. None of the single atmrp mutants displayed visible phenotypes under control conditions. In spite of the fact that AtMRP1 and AtMRP2 had been described as efficient ATP-dependent organic anion transporters in heterologous expression experiments, the contribution of three of the AtMRP genes (1, 11 and 12) to detoxification is marginal. Only knockouts in AtMRP2 exhibited a reduced sensitivity towards 1-chloro-2,4-dinitrobenzene, but not towards other herbicides. AtMRP2 but not AtMRP1, 11 and 12 is involved in chlorophyll degradation since ethylene-treated rosettes of atmrp2 showed reduced senescence, and AtMRP2 expression is induced during senescence. This suggests that AtMRP2 is involved in vacuolar transport of chlorophyll catabolites. Vacuolar uptake studies demonstrated that transport of typical MRP substrates was reduced in atmrp2. We conclude that within clade I, only AtMRP2 contributes significantly to overall organic anion pump activity in viv

Risk assessment of released cellulose nanocrystals – mimicking inhalatory exposure

Cellulose nanocrystals (CNCs) exhibit advantageous chemical and mechanical properties that render them attractive for a wide range of applications. During the life-cycle of CNC containing materials the nanocrystals could be released and become airborne, posing a potential inhalatory exposure risk towards humans. Absent reliable and dose-controlled models that mimic this exposure in situ is a central issue in gaining an insight into the CNC-lung interaction. Here, an Air Liquid Interface Cell Exposure system (ALICE), previously designed for studies of spherical nanoparticles, was used for the first time to establish a realistic physiological exposure test method for inhaled fiber shaped nano-objects; in this case, CNCs isolated from cotton. Applying a microscopy based approach the spatially homogenous deposition of CNCs was demonstrated as a prerequisite of the functioning of the ALICE. Furthermore, reliability and controllability of the system to nebulise high aspect ratio nanomaterials (HARN, e.g. CNCs) was shown. This opens the potential to thoroughly investigate the inhalatory risk of CNCs in vitro using a realistic exposure system

Not just fundamental research: education, equal opportunities, knowledge and technology transfer, and communication at the nccr bio-inspired materials

Besides conducting excellent fundamental research in domains of strategic importance, the National Centers of Competence in Research (NCCRs) also aim to become centers of reference for education, equal opportunities, and knowledge and technology transfer. These activities are supported by a communication strategy focused on specific target groups. This article describes some of the main strategic goals and achievements of the NCCR Bio-Inspired Materials, presents the main activities launched by the Center throughout its first funding phase, and provides a glimpse of new plans and directions for the second phase

Risk factors, aetiology and outcome of ischaemic stroke in young adults: the Swiss Young Stroke Study (SYSS).

Ischaemic stroke (IS) in young adults has been increasingly recognized as a serious health condition. Stroke aetiology is different in young adults than in the older population. This study aimed to investigate aetiology and risk factors, and to search for predictors of outcome and recurrence in young IS patients. We conducted a prospective multicentre study of consecutive IS patients aged 16-55 years. Baseline demographic data, risk factors, stroke aetiology including systematic genetic screening for Fabry disease and severity were assessed and related to functional neurological outcome (modified Rankin Scale, mRS), case fatality, employment status, place of residence, and recurrent cerebrovascular events at 3 months. In 624 IS patients (60 % men), median age was 46 (IQR 39-51) years and median NIHSS on admission 3 (IQR 1-8). Modifiable vascular risk factors were found in 73 %. Stroke aetiology was mostly cardioembolism (32 %) and of other defined origin (24 %), including cervicocerebral artery dissection (17 %). Fabry disease was diagnosed in 2 patients (0.3 %). Aetiology remained unknown in 20 %. Outcome at 3 months was favourable (mRS 0-1) in 61 % and fatal in 2.9 %. Stroke severity (p < 0.001) and diabetes mellitus (p = 0.023) predicted unfavourable outcome. Stroke recurrence rate at 3 months was 2.7 %. Previous stroke or TIA predicted recurrent cerebrovascular events (p = 0.012). In conclusion, most young adults with IS had modifiable vascular risk factors, emphasizing the importance of prevention strategies. Outcome was unfavourable in more than a third of patients and was associated with initial stroke severity and diabetes mellitus. Previous cerebrovascular events predicted recurrent ones

"It‘s Hard to Keep Track": Mapping a Shifting Nation in Dylan Horrocks‘s Hicksville

Using an art form that justifiably lays claim to both visual and literary genealogies—the graphic novel—Dylan Horrocks's Hicksville advances, rather than strictly challenges, many of the discussions which have informed the local manufacture of art and literature. My purpose in this thesis is to explore Horrocks's deployment of the critical perspectives of both art historical and literary discourse as they have developed from the pre-colonial to the twenty-first century in New Zealand, especially those associated with cultural nationalism. Hicksville claims a particular relation to the existing traditions within both art-historical and literary lines wherein they are conjoined in practice; integrated into the formal properties of Horrocks's work, the traditional concerns of local art and literature are not only subject matter but guide Horrocks‘s approach to narrative. The tension between art and place—the responsibility of the artist to the nation and its referents—appears in Hicksville as a structuring device rather than polemic via its concern with the economisation of art—or global capitalism—as it bears upon particular places and art practices. Yet Horrocks‘s handling of this theme upholds neither aestheticism nor populism. Rather, he invites the reader to make sense of extensive references to a range of artistic figures, from Heaphy to Hergé to Hotere, in a way that accounts for their equal force. Hicksville thus deliberately destabilises the joint histories of art and literary history to pointed effect, valuing its range of artistic and cultural inheritances—whether the visual or literary, the highbrow or lowbrow—for how they can remind us that contemporary artistic accounts of New Zealand must also consider the various ways the country has been constructed throughout its wide