Evaluation of bicinchoninic acid as a ligand for copper(I)-catalyzed azide-alkyne bioconjugations

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.The Cu(I)-catalyzed cycloaddition of terminal azides and alkynes (click chemistry) represents a highly specific reaction for the functionalization of biomolecules with chemical moieties such as dyes or polymer matrices. In this study we evaluate the use of bicinchoninic acid (BCA) as a ligand for Cu(I) under physiological reaction conditions. We demonstrate that the BCA–Cu(I)-complex represents an efficient catalyst for the conjugation of fluorophores or biotin to alkyne- or azide-functionalized proteins resulting in increased or at least equal reaction yields compared to commonly used catalysts like Cu(I) in complex with TBTA (tris[(1-benzyl-1H-1,2,3-triazol-4-yl)methyl]amine) or BPAA (bathophenanthroline disulfonic acid). The stabilization of Cu(I) with BCA represents a new strategy for achieving highly efficient bioconjugation reactions under physiological conditions in many application fields.EC/FP7/259043/EU/Computing Biomaterials/COMPBIOMATDFG, EXC 294, BIOSS Zentrum für Biologische Signalstudien - von der Analyse zur SyntheseDFG, GSC 4, Spemann Graduiertenschule für Biologie und Medizin (SGBM

Phytochrome-Based Extracellular Matrix with Reversibly Tunable mechanical Properties

Interrogation and control of cellular fate and function using optogenetics is providing revolutionary insights into biology. Optogenetic control of cells is achieved by coupling genetically encoded photoreceptors to cellular effectors and enables unprecedented spatiotemporal control of signaling processes. Here, a fast and reversibly switchable photoreceptor is used to tune the mechanical properties of polymer materials in a fully reversible, wavelength‐specific, and dose‐ and space‐controlled manner. By integrating engineered cyanobacterial phytochrome 1 into a poly(ethylene glycol) matrix, hydrogel materials responsive to light in the cell‐compatible red/far‐red spectrum are synthesized. These materials are applied to study in human mesenchymal stem cells how different mechanosignaling pathways respond to changing mechanical environments and to control the migration of primary immune cells in 3D. This optogenetics‐inspired matrix allows fundamental questions of how cells react to dynamic mechanical environments to be addressed. Further, remote control of such matrices can create new opportunities for tissue engineering or provide a basis for optically stimulated drug depots

Strigolactones play an important role in shaping exodermal morphology via a KAI2-dependent pathway

The majority of land plants have two suberized root barriers: the endodermis and the hypodermis (exodermis). Both barriers bear non-suberized passage cells that are thought to regulate water and nutrient exchange between the root and the soil. We learned a lot about endodermal passage cells, whereas our knowledge on hypodermal passage cells (HPCs) is still very scarce. Here we report on factors regulating the HPC number in Petunia roots. Strigolactones exhibit a positive effect, whereas supply of abscisic acid (ABA), ethylene, and auxin result in a strong reduction of the HPC number. Unexpectedly the strigolactone signaling mutant d14/dad2 showed significantly higher HPC numbers than the wild-type. In contrast, its mutant counterpart max2 of the heterodimeric receptor DAD2/MAX2 displayed a significant decrease in HPC number. A mutation in the Petunia karrikin sensor KAI2 exhibits drastically decreased HPC amounts, supporting the hypothesis that the dimeric KAI2/MAX2 receptor is central in determining the HPC number

Efecto del uso de agentes antipardeantes y atmósfera modificada sobre el pardeamiento enzimático en cascos de manzana 'Royal Gala'

Tesis para optar al Título Profesional de Ingeniero Agrónomo y al Grado de Magíster en Ciencias Agropecuarias, Mención Producción FrutícolaCon el fin de reducir el pardeamiento enzimático en cascos de manzana ‘Royal Gala’, debido a la ruptura de la integridad celular generada por el corte de la fruta, se aplicaron soluciones de agentes antipardeantes, en concentraciones bajas y altas, en base a cisteína (Cis; 0,1 y 0,3% p/v), ácido ascórbico (AA; 0,4 y 0,8% p/v) y ácido etilendiaminotetraacético (EDTA; 0,15 y 0,3% p/v), combinándolos de la siguiente forma: 0,1% Cis + 0,4% AA, 0,1% Cis + 0,15% EDTA, 0,4% AA + 0,15% EDTA, 0,3% Cis + 0,8% AA, 0,3% Cis + 0,3% EDTA y 0,8% AA + 0,3% EDTA, todos envasados en AM pasiva, es decir, en bolsas selladas sin modificación previa de su atmósfera interna. Se preparó un testigo envasado en AM pasiva y otro envasado en bolsa perforada, así la concentración gaseosa de este último se mantuvo similar a la del ambiente (21% O 2 y 0% CO 2 ), con el fin de determinar si hubo algún efecto de la atmósfera modificada sobre el pardeamiento enzimático. Las bolsas con cascos fueron almacenadas por 10 días a 5 °C. Durante el almacenamiento se evaluó tasa respiratoria, color, firmeza, parámetros químicos y sensoriales y actividad de la polifenol oxidasa (PPO). Luego de 1 día los cascos con 0,1% Cis + 0,15% EDTA y altas concentraciones de Cis + AA y EDTA presentaron los valores más altos de L y H ab (79,5 a 79,4 y 99,0 a 97,5 respectivamente) con ausencia de pardeamiento. Pasados 10 días, los cascos con altas concentraciones de antipardeantes fueron los únicos que no mostraron pardeamiento en su superficie, presentando valores de L entre 78,0 y 78,3. Entre 2 a 4 h después del procesamiento, se presentaron valores máximos de tasa respiratoria con un promedio de 18,4 mg CO 2 ·kg -1 h -1 , un 72,3% más alto que el de la fruta entera (5,1 mg CO 2 ·kg -1 h - 1 ). Tras 10 días la tasa respiratoria estuvo entre 7,1 y 11,4 mg CO 2 ·kg -1 h -1 . Pasado 1 día la actividad de la PPO estuvo entre los 0,08 a 0,30 U·mg prot -1 , sin apreciarse pardeamiento en los cascos con aplicación de antipardeantes. Luego de 10 días, los tratamientos de altas concentraciones de antipardeantes presentaron la menor actividad de la PPO (0,22 a 0,24 U·mg prot -1 ), reduciendo efectivamente el pardeamiento.In order to delay the enzymatic browning of apple slices 'Royal Gala', due to the breakdown of cellular integrity generated by cutting, antibrowning solutions were applied, at low and high concentrations, based on cysteine (Cys: 0.1 and 0.3% w/v), ascorbic acid (AA: 0.4 and 0.8% w/v) and ethylenediaminetetraacetic acid (EDTA: 0.15 and 0.3% w/v). The treatments evaluated were 0.1% Cys + 0.4% AA, 0.1% Cys + 0.15% EDTA, 0.4% AA + 0.15% EDTA, 0.3% Cys + 0.8% AA, 0.3% Cys + 0.3% EDTA y 0.8% AA + 0.3% EDTA, all packaged in passive MA, ie, in sealed bags without prior modification of internal atmosphere. Control treatment was packaged in passive MA and other packaged in perforated bags, both without antibrownings. These perforated bags kept gas concentration close to the air atmosphere (21% O 2 and 0% CO 2 ), to determine any effect of the gas levels on enzymatic browning. The apple slices were stored for 10 days at 5 °C. Respiratory rate, color, firmness, chemical and sensory parameters and polyphenol oxidase (PPO) activity were evaluated during cold storage. After 1 day slices with 0.1% Cys + 0.15% EDTA and high concentrations of Cys + AA and EDTA had highest values of L and H ab (79.4 to 79.5 and 97.5 to 99.0 respectively), and absence of enzymatic browning. After 10 days, apple slices with high concentrations of antibrowning agents did not show browning in the slices surface, with L values between 78.0 and 78.3. After 2 to 4 h of processing, high respiration rate, between 15.8 and 20.3 mg CO 2 ·kg -1 h -1 , higher than that of the whole fruit (5.1 mg CO 2 ·kg -1 h -1 ), were found. After 10 days, the respiratory rate was between 7.1 and 11.4 mg CO 2 ·kg -1 h -1 . After 1 day the PPO activity of apple slice was between 0.08 to 0.30 U·mg prot -1 , were no browning was found. After 10 days, the high-concentration treatments of antibrowning agents had the lowest PPO activity (0.22 to 0.24 U·mg prot -1 ), in non browning apple slices

Further Development of the Wildfire Module in CLIMADA by Integrating Physical Constraints

Wildfires are among the most destructive natural hazards and lead to substantial economic impacts. Therefore, assessing and quantifying their economic risk is of great interest to governmental authorities and (re-)insurance companies. To estimate the risk, the probabilistic wildfire module in the open-source software CLIMADA (CLIMate ADAptation) simulates wildfire seasons based on a cellular automaton. In this thesis, we extend the wildfire module by incorporating physical constraints. First, we combine land cover and population data to improve the fire spread simulation with the cellular automaton. Second, we add fire ignition probabilities based on population and historical data, defining particularly wildfire-prone regions. Third, we create the possibility to add a climate change signal as input to assess future economic impacts. The extended wildfire module is applied in ten different geographical regions to evaluate its accuracy using the same default parameters. In nine out of ten investigated regions, reasonable economic impact and burned area estimations are found for present-day climate conditions. To gain further insights into the performance of the wildfire module, we conduct two in-depth case studies for Portugal and central Chile. The case studies show that the probabilistically estimated economic impacts and burned area are in the same order of magnitude as derived from historical seasons. Additionally, including an end of the century climate change signal to the wildfire module leads to a substantial increase in economic impacts and burned area in Portugal. In contrast, the approach is not feasible to simulate the end of century climate conditions in central Chile since the interactions between the climatic conditions and wildfires are complex, and humans strongly influence wildfire activity. Therefore, implementing a climate change signal is only applicable in regions where the climatic conditions during the fire season directly determine the wildfire activity. We conclude that the wildfire module provides accurate estimations of the economic impacts and burned area in numerous regions across the world. The consistency in the parameters and the data-efficient approach enables probabilistic risk assessments without great effort, even in data-sparse geographical regions

Stücklisten-Management für Maschinen

Ausgangslage: Meldet heute eine Maschine ein kritisches Problem so werden zunächst erste Daten zum Fall erhoben. Ist das Problem komplexer, müssen Servicetechniker meist zweimal vor Ort gehen um dieses zu lösen da die benötigten Ersatzteile nicht vorher bekannt sind. Bei einem Serviceeinsatz wird oft auch die Stückliste einer Maschine im Feld verändert und stimmt dann nicht mehr mit der ursprünglich ausgelieferten überein. So verliert ein Maschinenhersteller nach und nach die genaue Kenntnis über den aktuellen Stand seiner Produkte. Mittels einer Softwarelösung sollen diese Änderungen nun während eines Serviceeinsatzes erfasst werden können. Vorgehen / Technologien: Als Beispiel für den Prototyp wurde eine Stückliste des an der HSR entwickelten Legoroboters zur Verfügung gestellt. Basierend auf diesen Daten sollte die Applikation entwickelt und entsprechende Showcases definiert werden. Die Webapplikation wurde mit dem Frontend Framework Angular und Material Design erstellt um eine benutzerfreundliche und intuitive Oberfläche zu gestalten. Dabei wurde der Schwerpunkt auf ein responsive Design gelegt. Somit können der Servicetechniker mit einem Smartphone und der Servicemanager im Büro die Software gleichermassen benutzen. Das Frontend interagiert mit einer mit ASP.NET Core programmierte REST-Schnittstelle welche durch seine Erweiterbarkeit sowie der Portierbarkeit auf andere Plattformen punktet. Es wurde bewusst eine REST-Schnittstelle verwendet um weiteren Applikationen den Zugriff auf die API zu ermöglichen. Bei der Datenhaltung wurde das Entity Framework in Verbindung mit einer Microsoft SQL Server Datenbank eingesetzt. Ergebnis: Der erarbeitete Prototyp legt den Grundstein für weitere Arbeiten auf dem Gebiet der Maschinenlebenszyklen. Die Software ist in der Lage anhand vier definierter Showcases die Funktionalitäten aufzuzeigen. Das zugrunde liegende System ist bereit für weitere Anforderungen und kann mit zusätzlichen API Endpunkten erweitert werden. Auch Anpassungen am Datenmodell sind möglich. Im auf Komponenten basierenden Frontend ist es denkbar, weitere Ansichten darzustellen und dabei auch bestehende Komponenten wiederzuverwenden