80 research outputs found
Microswimmers in Patterned Environments
We demonstrate with experiments and simulations how microscopic
self-propelled particles navigate through environments presenting complex
spatial features, which mimic the conditions inside cells, living organisms and
future lab-on-a-chip devices. In particular, we show that, in the presence of
periodic obstacles, microswimmers can steer even perpendicularly to an applied
force. Since such behaviour is very sensitive to the details of their specific
swimming style, it can be employed to develop advanced sorting, classification
and dialysis techniques.Comment: 4 pages, 4 figure
Exploring the Role of Industry 4.0 on Global Logistics:Challenges in Big Data and IoT
The globalization of the economy and consumers' increasing demand for customized products have led to a rise in the complexity of global logistics chains. In response to these challenges, the integration of logistics with the Internet of Things (IoT) and Big Data, known as Logistics 4.0, offers opportunities for more efficient planning, control, and adaptation of logistics processes. Industry 4.0, with its emphasis on IoT and Big Data analytics, significantly influences the logistics sector, making it a pioneer in the digital transformation of the entire economy. This paper seeks to review and analyze the role and impacts of Industry 4.0 on global logistics, while also addressing the main challenges related to IT security, data protection, and successful implementation of Big Data Analytics in the supply chain. Additionally, it aims to explore the changes in work systems within companies due to digital transformation in logistics
Universal Preparability of States and Asymptotic Completeness
We introduce a notion of universal preparability for a state of a system,
more precisely: for a normal state on a von Neumann algebra. It describes a
situation where from an arbitrary initial state it is possible to prepare a
target state with arbitrary precision by a repeated interaction with a sequence
of copies of another system. For we give criteria
sufficient to ensure that all normal states are universally preparable which
can be verified for a class of non-commutative birth and death processes
realized, in particular, by the interaction of a micromaser with a stream of
atoms. As a tool the theory of tight sequences of states and of stationary
states is further developed and we show that in the presence of stationary
faithful normal states universal preparability of all normal states is
equivalent to asymptotic completeness, a notion studied earlier in connection
with the scattering theory of non-commutative Markov processes.Comment: 36 pages. To be published in "Communications in Mathematical
Physics". v2 is the accepted authors' version. Compared to v1 there are
additional explanations, in particular Remark 7.
Quantitative cross-species extrapolation between humans and fish: The case of the anti-depressant fluoxetine
This article has been made available through the Brunel Open Access Publishing Fund.Fish are an important model for the pharmacological and toxicological characterization of human pharmaceuticals in drug discovery, drug safety assessment and environmental toxicology. However, do fish respond to pharmaceuticals as humans do? To address this question, we provide a novel quantitative cross-species extrapolation approach (qCSE) based on the hypothesis that similar plasma concentrations of pharmaceuticals cause comparable target-mediated effects in both humans and fish at similar level of biological organization (Read-Across Hypothesis). To validate this hypothesis, the behavioural effects of the anti-depressant drug fluoxetine on the fish model fathead minnow (Pimephales promelas) were used as test case. Fish were exposed for 28 days to a range of measured water concentrations of fluoxetine (0.1, 1.0, 8.0, 16, 32, 64 μg/L) to produce plasma concentrations below, equal and above the range of Human Therapeutic Plasma Concentrations (HTPCs). Fluoxetine and its metabolite, norfluoxetine, were quantified in the plasma of individual fish and linked to behavioural anxiety-related endpoints. The minimum drug plasma concentrations that elicited anxiolytic responses in fish were above the upper value of the HTPC range, whereas no effects were observed at plasma concentrations below the HTPCs. In vivo metabolism of fluoxetine in humans and fish was similar, and displayed bi-phasic concentration-dependent kinetics driven by the auto-inhibitory dynamics and saturation of the enzymes that convert fluoxetine into norfluoxetine. The sensitivity of fish to fluoxetine was not so dissimilar from that of patients affected by general anxiety disorders. These results represent the first direct evidence of measured internal dose response effect of a pharmaceutical in fish, hence validating the Read-Across hypothesis applied to fluoxetine. Overall, this study demonstrates that the qCSE approach, anchored to internal drug concentrations, is a powerful tool to guide the assessment of the sensitivity of fish to pharmaceuticals, and strengthens the translational power of the cross-species extrapolation
Obatoclax Inhibits Alphavirus Membrane Fusion by Neutralizing the Acidic Environment of Endocytic Compartments
As new pathogenic viruses continue to emerge, it is paramount to have intervention strategies that target a common denominator in these pathogens. The fusion of viral and cellular membranes during viral entry is one such process that is used by many pathogenic viruses, including chikungunya virus, West Nile virus, and influenza virus. Obatoclax, a small-molecule antagonist of the Bcl-2 family of proteins, was previously determined to have activity against influenza A virus and also Sindbis virus. Here, we report it to be active against alphaviruses, like chikungunya virus (50% effective concentration [EC50] = 0.03 mu M) and Semliki Forest virus (SFV; EC50 = 0.11 mu M). Obatoclax inhibited viral entry processes in an SFV temperaturesensitive mutant entry assay. A neutral red retention assay revealed that obatoclax induces the rapid neutralization of the acidic environment of endolysosomal vesicles and thereby most likely inhibits viral fusion. Characterization of escape mutants revealed that the L369I mutation in the SFV E1 fusion protein was sufficient to confer partial resistance against obatoclax. Other inhibitors that target the Bcl-2 family of antiapoptotic proteins inhibited neither viral entry nor endolysosomal acidification, suggesting that the antiviral mechanism of obatoclax does not depend on its anticancer targets. Obatoclax inhibited the growth of flaviviruses, like Zika virus, West Nile virus, and yellow fever virus, which require low pH for fusion, but not that of pH-independent picornaviruses, like coxsackievirus A9, echovirus 6, and echovirus 7. In conclusion, obatoclax is a novel inhibitor of endosomal acidification that prevents viral fusion and that could be pursued as a potential broad-spectrum antiviral candidate.Peer reviewe
Ecotoxicity of disinfectant benzalkonium chloride and its mixture with antineoplastic drug 5-fluorouracil towards alga Pseudokirchneriella subcapitata
Background Benzalkonium chloride (BAC) is one of the most common ingredients of the disinfectants. It is commonly detected in surface and wastewaters where it can interact with the residues of pharmaceuticals that are also common wastewater pollutants. Among the latter, the residues of antineoplastic drugs are of particular concern as recent studies showed that they can induce adverse effect in aquatic organisms at environmentally relevant concentrations. Methods Ecotoxicity of BAC as an individual compound and in a binary mixture with an antineoplastic drug 5-fluorouracil (5-FU) was determined towards alga Pseudokirchneriella subcapitata, a representative of primary producers. The toxicity of the BAC+5-FU binary mixture was predicted by the two basic models: concentration addition (CA) and independent action (IA), and compared to the experimentally determined toxicity. Additionally combination index (CI) was calculated to determine the type of interaction. Results After 72 h exposure to BAC a concentration dependent growth inhibition of P. subcapitata was observed with an EC50 0.255 mg/L. Comparing the predicted no effect concentration to the measured concentrations in the surface waters indicate that BAC at current applications and occurrence in aquatic environment may affect algal populations. The measured toxicity of the mixture was higher from the predicted and calculated CI confirmed synergistic effect on the inhibition of algal growth, at least at EC50 concentration. The observed synergism may have impact on the overall toxicity of wastewaters, whereas it is less likely for general environments because the concentrations of 5-FU are several orders of magnitude lower from its predicted no effect concentration. Discussion These results indicate that combined effects of mixtures of disinfectants and antineoplastic drugs should be considered in particular when dealing with environmental risk assessment as well as the management of municipal and hospital wastewaters
One Planet: One Health. A Call to Support the Initiative on a Global Science-Policy Body on Chemicals and Waste
The chemical pollution crisis severely threatens human and environmental health globally. To tackle this challenge the establishment of an overarching international science–policy body has recently been suggested. We strongly support this initiative based on the awareness that humanity has already likely left the safe operating space within planetary boundaries for novel entities including chemical pollution. Immediate action is essential and needs to be informed by sound scientific knowledge and data compiled and critically evaluated by an overarching science–policy interface body. Major challenges for such a body are (i) to foster global knowledge production on exposure, impacts and governance going beyond data-rich regions (e.g., Europe and North America), (ii) to cover the entirety of hazardous chemicals, mixtures and wastes, (iii) to follow a one-health perspective considering the risks posed by chemicals and waste on ecosystem and human health, and (iv) to strive for solution-oriented assessments based on systems thinking. Based on multiple evidence on urgent action on a global scale, we call scientists and practitioners to mobilize their scientific networks and to intensify science–policy interaction with national governments to support the negotiations on the establishment of an intergovernmental body based on scientific knowledge explaining the anticipated benefit for human and environmental health
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