Sensitive superoxide detection in vascular cells by the new chemiluminescence dye L-012

The detection superoxide production in vascular cells is usually limited by a low sensitivity of available assays, We tested the applicability of the luminol derivate L-012 {[}8-amino-5-chloro-7-phenylpyridol{[}3,4-d]pyridazine-l,4(2H,3H)dione] to measure superoxide production in cultured endothelial cells (human umbilical vein endothelial cells) and rat aortic segments. Following stimulation with the protein kinase stimulator phorbol 12-myristate 13-acetate (PMA, 1 mu M) there was an 2,8-fold increase of L-012 chemiluminescence, whereas incubation with angiotensin II (100 nM) did not result in a measurable increase. Addition of vanadate (100 mu M) considerably increased the chemiluminescence (up to 17-fold) after PMA and made possible the detection of an enhanced superoxide production after stimulation with angiotensin II (by 1.7-fold). This was due to a similar to 9-fold increase in signal intensity of L-012 in the presence of vanadate, Prolonged incubation with vanadate also led to a tyrosine phosphorylation-dependent increase in superoxide formation which was predominantly produced by an NAD(P)H oxidase. Short-Term vanadate-enhanced L-012 chemiluminescence represents a highly sensitive assay making it possible to detect small changes of superoxide formation in intact vascular cells. Copyright(C) 1999 S. Karger AG. Basel

Laser-induced forward transfer (LIFT) of water soluble polyvinyl alcohol (PVA) polymers for use as support material for 3D-printed structures

The additive microfabrication method of laser-induced forward transfer (LIFT) permits the creation of functional microstructures with feature sizes down to below a micrometre [1]. Compared to other additive manufacturing techniques, LIFT can be used to deposit a broad range of materials in a contactless fashion. LIFT features the possibility of building out of plane features, but is currently limited to 2D or 2½D structures [2–4]. That is because printing of 3D structures requires sophisticated printing strategies, such as mechanical support structures and post-processing, as the material to be printed is in the liquid phase. Therefore, we propose the use of water-soluble materials as a support (and sacrificial) material, which can be easily removed after printing, by submerging the printed structure in water, without exposing the sample to more aggressive solvents or sintering treatments. Here, we present studies on LIFT printing of polyvinyl alcohol (PVA) polymer thin films via a picosecond pulsed laser source. Glass carriers are coated with a solution of PVA (donor) and brought into proximity to a receiver substrate (glass, silicon) once dried. Focussing of a laser pulse with a beam radius of 2 µm at the interface of carrier and donor leads to the ejection of a small volume of PVA that is being deposited on a receiver substrate. The effect of laser pulse fluence , donor film thickness and receiver material on the morphology (shape and size) of the deposits are studied. Adhesion of the deposits on the receiver is verified via deposition on various receiver materials and via a tape test. The solubility of PVA after laser irradiation is confirmed via dissolution in de-ionised water. In our study, the feasibility of the concept of printing PVA with the help of LIFT is demonstrated. The transfer process maintains the ability of water solubility of the deposits allowing the use as support material in LIFT printing of complex 3D structures. Future studies will investigate the compatibility (i.e. adhesion) of PVA with relevant donor materials, such as metals and functional polymers. References: [1] A. Piqué and P. Serra (2018) Laser Printing of Functional Materials. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA. [2] R. C. Y. Auyeung, H. Kim, A. J. Birnbaum, M. Zalalutdinov, S. A. Mathews, and A. Piqué (2009) Laser decal transfer of freestanding microcantilevers and microbridges, Appl. Phys. A, vol. 97, no. 3, pp. 513–519. [3] C. W. Visser, R. Pohl, C. Sun, G.-W. Römer, B. Huis in ‘t Veld, and D. Lohse (2015) Toward 3D Printing of Pure Metals by Laser-Induced Forward Transfer, Adv. Mater., vol. 27, no. 27, pp. 4087–4092. [4] J. Luo et al. (2017) Printing Functional 3D Microdevices by Laser-Induced Forward Transfer, Small, vol. 13, no. 9, p. 1602553

Towards a Blockchain Technology Framework – Literature Review on components in blockchain implementations

The goal of this work is to obtain a framework that represents the technological core aspects of blockchain, separated into components, their subcategories and related basic technologies. In order to gain a holistic view of blockchain, with the help of the framework, technologies constructs should be made identifiable as blockchain. For this purpose, a literature review will be conducted to investigate previous approaches to the component-wise division of blockchain technologies. Subsequently, a literature analysis will be conducted in which five established blockchain systems will be analysed and their implementations will be assigned to the general components. For evaluation, a further sixth blockchain technology is used to confirm the basic framework. It becomes apparent that the framework allows a classification of blockchain systems into technologies. The framework has potential for expansion by adding further technology features to make the framework even more useful

Decentralised Autonomous Organisations in Organisational Design Theory

As Decentralised Autonomous Organisation (DAO) is a new emerging form of organisation with unrevealed characteristics, this study examines how DAO can be classified in terms of organisational design theory and provides an overview of its characteristics. The investigation could further provide guidance on what types of organisations can be easily transformed into a DAO. A deeper look into the knowledge base on organisational design theory and organisational forms is essential as well as characteristic properties. In regard of DAO, the underlying concepts of blockchain and smart contracts are marked as they serve a better understanding, which is needed to characterise DAO. An analysis of DAO will specify how they are classified in terms of organisational design and how they differ compared to traditional organisation forms, which will be displayed in an overview. The results are discussed and concluded, also comprising the highlighting of potential paths for future work

The Linkage to Business Goals in Data Science Projects

Modern data analytics equips businesses to make data-driven decisions by revealing patterns and insights that enhance strategic planning, operational efficiency, and process optimization. Its applications encompass personalized marketing through customer segmentation, predictive modelling for fraud detection, and enhancing security. A significant methodology in this realm is the Cross-Industry Standard Process for Data Mining (CRISP-DM), where the Business Understanding phase aims to ensure data science projects align with overarching business goals. However, challenges arise when these business objectives are ambiguous, ill-defined, or evolving. The complexity of data analytics projects underscores the need for domain expertise and robust collaboration between data scientists, business stakeholders, and domain experts. The imperative is to bridge the technical and business perspectives, manage expectations, and define project scopes. The short paper at hand addresses the question how data analytic goals can systematically align with business objectives in data science projects. By incorporating methods from Enterprise Architecture Management, we propose a structured approach for goal determination in data science projects, ensuring business and data mining objectives are seamlessly integrated

A Literature Review on the Challenges of Applying Test-Driven Development in Software Engineering

Due to the ongoing trend of digitalization, the importance of software for today’s society is continuously increasing. Naturally, there is also a huge interest in improving its quality, which led to a highly active research community dedicated to this aim. Consequently, a plethora of propositions, tools, and methods emerged from the corresponding efforts. One of the approaches that have become highly prominent is the concept of test-driven development (TDD) that increases the quality of created software by restructuring the development process. However, such a big change to the followed procedures is usually also accompanied by major challenges that pose a risk for the achievement of the set targets. In order to find ways to overcome them, or at least to mitigate their impact, it is necessary to identify them and to subsequently raise awareness. Furthermore, since the effect of TDD on productivity and quality is already extensively researched, this work focuses only on issues besides these aspects. For this purpose, a literature review is presented that focuses on the challenges of TDD. In doing so, challenges that can be attributed to the three categories of people, software, and process are identified and potential avenues for future research are discussed

Crucial role of local peroxynitrite formation in neutrophil-induced endothelial cell activation

Introduction and methods: The reaction of superoxide anions and NO not only results in a decreased availability of NO, but also leads to the formation of peroxynitrite, the role of which in the cardiovascular system is still discussed controversially. In cultured human endothelial cells, we studied whether there is a significant interaction between endothelial NO and neutrophil-derived superoxide anions in terms of endothelial peroxynitrite formation. We particularly studied whether a significantly higher redox-stress can be found in those endothelial cells directly adjacent to an activated neutrophil. Results: A considerable part of the 2,7-dihydrodichlorofluoresceine signal in endothelial cells was due to oxidation by peroxynitrite. Providing superoxide radicals by enzymatic source or by the neutrophil respiratory burst increased the fluorescence, which was attenuated by blockade of endothelial NO-synthase, suggesting that peroxynitrite was formed from neutrophil- or extracellular enzyme-derived superoxide and endothelial NO. Considerably higher fluorescence intensity was observed in endothelial cells in direct neighborhood to a neutrophil. This was particularly pronounced in the presence of a NO-donor and was accompanied by a strong activation of NF-κB and increased expression of E-selectin in these cells. Conclusion: Endothelial cells adjacent to neutrophils may have elevated levels of peroxynitrite that result in an increased expression of adhesion molecules. Such cells might represent a preferential site for adhesion and migration of additional neutrophils when simultaneously high concentrations of NO and neutrophil-derived superoxide are present

A test method to assess operator safety using Closed Transfer Systems

Closed transfer systems (CTS) are devices for the contactless transfer of plant protection products (PPP) into pesticide application equipment (PAE). They are intended to protect the operator against contamination with undiluted PPP during filling of the sprayer. CTS are universal and can be mounted on a wide range of different types and sizes of PAE. They are able to transfer the PPP from container of diverse sizes, enable also partial draining and containers can be easily rinsed after complete emptying. At the moment there is no reliable information about the contribution of CTS to operator safety. For this reason a test method was established in order to compare the operator´s contamination after the dosing process using CTS and conventional filling into the PAE. Aim of the project was to quantify the dermal exposure at different parts of the operator´s body. Instead of PPP a mixture of water and a fluorescent tracer (Pyranin) was used. It was filled into 10-Litercontainers and sealed. The operator was equipped with Personal Protective Clothing which was washed after the filling process in order to determine the amount of contamination on different parts of the body by using fluorometry. The different filling processes were performed by 3 different persons with 5 repetitions per setting using an attached field crop sprayer (RAU D2) with a CTS mounted on the induction hopper and also on the dome shaft. The results show that CTS can significantly help to minimize operator exposure in comparison to conventional filling and that the test procedure established is able to fulfil the defined aims of testing CTS.Closed transfer systems (CTS) are devices for the contactless transfer of plant protection products (PPP) into pesticide application equipment (PAE). They are intended to protect the operator against contamination with undiluted PPP during filling of the sprayer. CTS are universal and can be mounted on a wide range of different types and sizes of PAE. They are able to transfer the PPP from container of diverse sizes, enable also partial draining and containers can be easily rinsed after complete emptying. At the moment there is no reliable information about the contribution of CTS to operator safety. For this reason a test method was established in order to compare the operator´s contamination after the dosing process using CTS and conventional filling into the PAE. Aim of the project was to quantify the dermal exposure at different parts of the operator´s body. Instead of PPP a mixture of water and a fluorescent tracer (Pyranin) was used. It was filled into 10-Litercontainers and sealed. The operator was equipped with Personal Protective Clothing which was washed after the filling process in order to determine the amount of contamination on different parts of the body by using fluorometry. The different filling processes were performed by 3 different persons with 5 repetitions per setting using an attached field crop sprayer (RAU D2) with a CTS mounted on the induction hopper and also on the dome shaft. The results show that CTS can significantly help to minimize operator exposure in comparison to conventional filling and that the test procedure established is able to fulfil the defined aims of testing CTS

How do users design scientific workflows? The Case of Snakemake

Scientific workflows automate the analysis of large-scale scientific data, fostering the reuse of data processing operators as well as the reproducibility and traceability of analysis results. In exploratory research, however, workflows are continuously adapted, utilizing a wide range of tools and software libraries, to test scientific hypotheses. Script-based workflow engines cater to the required flexibility through direct integration of programming primitives but lack abstractions for interactive exploration of the workflow design by a user during workflow execution. To derive requirements for such interactive workflows, we conduct an empirical study on the use of Snakemake, a popular Python-based workflow engine. Based on workflows collected from 1602 GitHub repositories, we present insights on common structures of Snakemake workflows, as well as the language features typically adopted in their specification