591 research outputs found
Proline-Rich Peptides with Improved Antimicrobial Activity against E. coli, K. Pneumoniae, and A. Baumannii.
Proline-rich antimicrobial peptides (PrAMPs) are promising agents to combat multi-drug resistant pathogens due to a high antimicrobial activity, yet low cytotoxicity. A library of derivatives of the PrAMP Bac5(1-17) was synthesized and screened to identify which residues are relevant for its activity. In this way, we discovered that two central motifs -PIRXP- cannot be modified, while residues at N- and C- termini tolerated some variations. We found five Bac5(1-17) derivatives bearing 1-5 substitutions, with an increased number of arginine and/or tryptophan residues, exhibiting improved antimicrobial activity and broader spectrum of activity while retaining low cytotoxicity toward eukaryotic cells. Transcription/translation and bacterial membrane permeabilization assays showed that these new derivatives still retained the ability to strongly inhibit bacterial protein synthesis, but also acquired permeabilizing activity to different degrees. These new Bac5(1-17) derivatives therefore show a dual mode of action which could hinder the selection of bacterial resistance against these molecules
Water–Energy Nexus: Addressing Stakeholder Preferences in Jordan
The water and energy sectors are fundamentally linked. In Jordan, especially in the face of a changing climate, the water–energy nexus holds a number of challenges but also opportunities. A key point in exploring synergies is the identification of such, as well as the communication between the water and energy sectors. This paper promotes the importance of using a co-creative approach to help resolve opposing views and assessing stakeholder preferences in the context of the water–energy nexus in Jordan. A computer-supported, co-creative approach was used to evaluate stakeholder preferences and opinions on criteria and future scenarios for the energy and water sector in Jordan, identifying common difficulties and possibilities. The criteria describe socio-ecological aspects as well as techno-economic aspects for both systems. Discussing a set of preliminary scenarios describing possible energy and water futures ranked under a set of sector relevant criteria, a consensus between both stakeholder groups is reached. The robustness of results is determined, using a second-order probabilistic approach. The results indicate that there are no fundamental conflicts between the energy and water stakeholder groups. Applying a participatory multi-stakeholder, multi-criteria framework to the energy-water nexus case in Jordan promotes a clear understanding of where different stakeholder groups stand. This understanding and agreement can form the basis of a joint water–energy nexus policy used in the continued negotiation process between and within national and international cooperation, as well as promoting and developing acceptable suggestions to solve complex problems for both sectors
Pore-scale Modeling of Viscous Flow and Induced Forces in Dense Sphere Packings
We propose a method for effectively upscaling incompressible viscous flow in
large random polydispersed sphere packings: the emphasis of this method is on
the determination of the forces applied on the solid particles by the fluid.
Pore bodies and their connections are defined locally through a regular
Delaunay triangulation of the packings. Viscous flow equations are upscaled at
the pore level, and approximated with a finite volume numerical scheme. We
compare numerical simulations of the proposed method to detailed finite element
(FEM) simulations of the Stokes equations for assemblies of 8 to 200 spheres. A
good agreement is found both in terms of forces exerted on the solid particles
and effective permeability coefficients
Correct quantum chemistry in a minimal basis from effective Hamiltonians
We describe how to create ab-initio effective Hamiltonians that qualitatively
describe correct chemistry even when used with a minimal basis. The
Hamiltonians are obtained by folding correlation down from a large parent basis
into a small, or minimal, target basis, using the machinery of canonical
transformations. We demonstrate the quality of these effective Hamiltonians to
correctly capture a wide range of excited states in water, nitrogen, and
ethylene, and to describe ground and excited state bond-breaking in nitrogen
and the chromium dimer, all in small or minimal basis sets
Predictors of progression free survival, overall survival and early cessation of chemotherapy in women with potentially platinum sensitive (PPS) recurrent ovarian cancer (ROC) starting third or subsequent line(> 3) chemotherapy – the GCIG Symptom Benefit Study (SBS)
Background:
Potentially platinum sensitive recurrent ovarian cancer (PPS ROC) is defined by a platinum-free interval of >6 months, and usually treated with platinum-based chemotherapy with variable response and benefit in women who have had 3 or more lines of chemotherapy(≥3). We identified baseline characteristics (health-related quality of life[HRQL] and clinicopathological factors), associated with PFS, OS and early progression (within 8 weeks). The goal is to improve patient selection for chemotherapy based on a nomogram predicting PFS.
Methods:
HRQL was assessed with EORTC QLQ-C30/QLQ-OV28. Associations with PFS and OS were assessed with Cox proportional hazards regression. Variables significant in univariable analysis were included in multivariable analyses using backward elimination to select those significant. Associations with stopping chemotherapy early were assessed with logistic regression.
Results:
378 women were enrolled, with median(m)OS and PFS of 16.6 months and 5.3 months, respectively. The majority had ECOGPS 0–1. Chemotherapy was stopped early in 45/378 participants (12%); with mOS 3.4 months (95% CI: 1.7–7.2). Physical function(PF), role function(RF), cognitive function(CF), social function(SF), Global Health Status(GHS) and abdominal/GI symptoms(AGIS) were significant univariable predictors of PFS(p < 0.030). SF remained significant after adjusting for clinicopathological factors; p = 0.03. PF, RF, CF, SF, GHS and AGIS were significant univariable predictors of OS (p < 0.007); PF, RF, SF and GHS remained significant predictors of OS in multivariable models; p < 0.007. Poor baseline PF and GHS were significant univariable predictors of stopping chemotherapy early (p < 0.007) but neither remained significant after adjusting for clinicopathological factors.
Conclusion:
Baseline HRQL is simple to measure, is predictive of PFS and OS and when used in conjunction with clinicopathological prognostic factors, can assist with clinical decision making and treatment recommendations for women with PPSROC≥3
Umweltgerechte Prozessführung und Zustandserkennung in Chemieanlagen mit neuronalen Netzen - Teilvorhaben 2: Konzipierung und Erprobung des Zustandserkennungsverfahrens
Im Rahmen des Teilvorhabens wurde ein Online-Monitoring-System für stark exotherme Reaktionen entwickelt, das das Bedienungspersonal bei der optimalen und umweltgerechten Prozessführung von komplexen oder sicherheitstechnisch schwierigen Semibatch-Prozessen in Rührkesselreaktoren (Batch-Reaktoren) unterstützen soll. Das Monitoring-System (MoSys) basiert auf dimensionslosen Stoff- und Wärmebilanzen mit adaptiven Komponenten. MoSys muss zuerst mit den Prozessdaten von normalen und unerwünschten Batch-Verläufen angelernt werden, die im Miniplant unter den Bedingungen des Industrieprozesses durchgeführt wurden. Die Adaption der Bilanzmodelle an die Zielanlage erfolgt durch zweischichtige Perceptron-Netze. Um eine vollständige Maßstabsübertragung zu gewährleisten, sollte MoSys mit Prozessdaten von mindestens einem normalen Batch-Verlauf in der Chemieanlage angepasst und validiert werden. MoSys wurde sowohl für eine homogene exotherme Veresterungsreaktion als auch für einen komplexen heterogenen exothermen Hydrierprozess konzipiert. Experimentelle Tests wurden für die Veresterung in einer Pilotanlage und für die Hydrierung in einer industriellen Chemieanlage durchgeführt. Zur Industrieerprobung wurde MoSys in ein Batch-Informations-Management-System (BIMS) integriert, das auch entwickelt und in das Prozessleitsystem (PLS) einer Mehrzweckanlage im Feinchemie-Werk Radebeul (Degussa AG) implementiert wurde. Dadurch konnten die MoSys-Ausgaben simultan mit wichtigen Prozesssignalen auf den Terminals des PLS visualisiert werden. Zum Beispiel werden der Hydrierungsfortschritt, das vorhergesagte Reaktionsende und die Konzentrationsverläufe des Edukts, Zwischenprodukts und Produkts auf den Terminals der Operatorstationen angezeigt. Wenn unerwünschte Betriebszustände auftreten, wird das Bedienungspersonal frühzeitig alarmiert und Anweisungen für Gegenmaßnahmen, die nur vom Operator ausgeführt werden dürfen, werden auf den Terminals angezeigt. Die Leistungsfähigkeit von MoSys/BIMS konnte während zweier Hydrierungs-Produktionskampagnen nachgewiesen werden
Opening the black box of energy modelling: Strategies and lessons learned
The global energy system is undergoing a major transition, and in energy planning and decision-making across governments, industry and academia, models play a crucial role. Because of their policy relevance and contested nature, the transparency and open availability of energy models and data are of particular importance. Here we provide a practical how-to guide based on the collective experience of members of the Open Energy Modelling Initiative (Openmod). We discuss key steps to consider when opening code and data, including determining intellectual property ownership, choosing a licence and appropriate modelling languages, distributing code and data, and providing support and building communities. After illustrating these decisions with examples and lessons learned from the community, we conclude that even though individual researchers' choices are important, institutional changes are still also necessary for more openness and transparency in energy research
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Overview of mathematical approaches used to model bacterial chemotaxis II: bacterial populations
We review the application of mathematical modeling to understanding the behavior of populations of chemotactic bacteria. The application of continuum mathematical models, in particular generalized Keller–Segel models, is discussed along with attempts to incorporate the microscale (individual) behavior on the macroscale, modeling the interaction between different species of bacteria, the interaction of bacteria with their environment, and methods used to obtain experimentally verified parameter values. We allude briefly to the role of modeling pattern formation in understanding collective behavior within bacterial populations. Various aspects of each model are discussed and areas for possible future research are postulated
Alternatives to antibiotics-a pipeline portfolio review
Antibiotics have saved countless lives and enabled the development of modern medicine over the past 70 years. However, it is clear that the success of antibiotics might only have been temporary and we now expect a long-term and perhaps never-ending challenge to find new therapies to combat antibiotic-resistant bacteria. A broader approach to address bacterial infection is needed. In this Review, we discuss alternatives to antibiotics, which we defined as non-compound approaches (products other than classic antibacterial agents) that target bacteria or any approaches that target the host. The most advanced approaches are antibodies, probiotics, and vaccines in phase 2 and phase 3 trials. This first wave of alternatives to antibiotics will probably best serve as adjunctive or preventive therapies, which suggests that conventional antibiotics are still needed. Funding of more than £1·5 billion is needed over 10 years to test and develop these alternatives to antibiotics. Investment needs to be partnered with translational expertise and targeted to support the validation of these approaches in phase 2 trials, which would be a catalyst for active engagement and investment by the pharmaceutical and biotechnology industry. Only a sustained, concerted, and coordinated international effort will provide the solutions needed for the future.</p
Neutralization of (NK-cell-derived) B-cell activating factor by Belimumab restores sensitivity of chronic lymphoid leukemia cells to direct and Rituximab-induced NK lysis.
Natural killer (NK) cells are cytotoxic lymphocytes that substantially contribute to the therapeutic benefit of antitumor antibodies like Rituximab, a crucial component in the treatment of B-cell malignancies. In chronic lymphocytic leukemia (CLL), the ability of NK cells to lyse the malignant cells and to mediate antibody-dependent cellular cytotoxicity upon Fc receptor stimulation is compromised, but the underlying mechanisms are largely unclear. We report here that NK-cells activation-dependently produce the tumor necrosis factor family member 'B-cell activating factor' (BAFF) in soluble form with no detectable surface expression, also in response to Fc receptor triggering by therapeutic CD20-antibodies. BAFF in turn enhanced the metabolic activity of primary CLL cells and impaired direct and Rituximab-induced lysis of CLL cells without affecting NK reactivity per se. The neutralizing BAFF antibody Belimumab, which is approved for treatment of systemic lupus erythematosus, prevented the effects of BAFF on the metabolism of CLL cells and restored their susceptibility to direct and Rituximab-induced NK-cell killing in allogeneic and autologous experimental systems. Our findings unravel the involvement of BAFF in the resistance of CLL cells to NK-cell antitumor immunity and Rituximab treatment and point to a benefit of combinatory approaches employing BAFF-neutralizing drugs in B-cell malignancies
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