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Bei der Stärkeproduktion entstehendes Kartoffelfruchtwasser besitzt mit 2 – 3 % einen hohen Anteil an ernährungsphysiologisch interessanten Proteinen. Die industrielle Gewinnung dieser Proteinfracht liefert jedoch lediglich ein minderwertiges, denaturiertes Produkt. Mit Hilfe der Membranadsorber-Technologie lassen sich aus Kartoffelfruchtwasser unter milden Reaktionsbedingungen native bioaktive Proteinfraktionen gewinnen. Geeignete Trennbedingungen wurden im Labormaßstab entwickelt und in den Technikumsmaßstab übertragen. An Anionenaustauscher-Membranadsorbern mit einer Membranfläche von 10 000 cm2 wurde eine Patatinhaltige Fraktion (44 kDa) mit Bindungskapazitäten von 0,37 mg/cm2 isoliert. Eine niedermolekulare Proteinfraktion mit Protease-Inhibitoren konnte durch Kationenaustauscher-Membranadsorber mit Bindungskapazitäten von 1,00 mg/cm2 gewonnen werden. Sie ist für verschiedenste Applikationen in der pharmazeutischen, kosmetischen und der Nahrungsmittelindustrie interessant z. B. für Appetitzügler oder muskelaufbauende Proteinpräparate. Der Aufreinigung der nativen Proteinfraktionen durch Ultra-/Diafiltration schließt sich die Konfektionierung durch Sprühtrocknung an. Die bioanalytische Charakterisierung der Produkte belegt die Reinheit und die enzymatische Aktivität sowie die Abreicherung von Störkomponenten wie Glykoalkaloide und Polyphenoloxidasen.
Experience has shown that a priori created static resource allocation plans are vulnerable to runtime deviations and hence often become uneconomic or highly exceed a predefined soft deadline. The assumption of constant task execution times during allocation planning is even more unlikely in a cloud environment where virtualized resources vary in performance. Revising the initially created resource allocation plan at runtime allows the scheduler to react on deviations between planning and execution. Such an adaptive rescheduling of a many-task application workflow is only feasible, when the planning time can be handled efficiently at runtime. In this paper, we present the static low-complexity resource allocation planning algorithm (LCP) applicable to efficiently schedule many-task scientific application workflows on cloud resources of different capabilities. The benefits of the presented algorithm are benchmarked against alternative approaches. The benchmark results show that LCP is not only able to compete against higher complexity algorithms in terms of planned costs and planned makespan but also outperforms them significantly by magnitudes of 2 to 160 in terms of required planning time. Hence, LCP is superior in terms of practical usability where low planning time is essential such as in our targeted online rescheduling scenario.
In this study, the performance of an integrated body-imaging array for 7 T with 32 radiofrequency (RF) channels under consideration of local specific absorption rate (SAR), tissue temperature, and thermal dose limits was evaluated and the imaging performance was compared with a clinical 3 T body coil.
Thirty-two transmit elements were placed in three rings between the bore liner and RF shield of the gradient coil. Slice-selective RF pulse optimizations for B1 shimming and spokes were performed for differently oriented slices in the body under consideration of realistic constraints for power and local SAR. To improve the B1+ homogeneity, safety assessments based on temperature and thermal dose were performed to possibly allow for higher input power for the pulse optimization than permissible with SAR limits.
The results showed that using two spokes, the 7 T array outperformed the 3 T birdcage in all the considered regions of interest. However, a significantly higher SAR or lower duty cycle at 7 T is necessary in some cases to achieve similar B1+ homogeneity as at 3 T. The homogeneity in up to 50 cm-long coronal slices can particularly benefit from the high RF shim performance provided by the 32 RF channels. The thermal dose approach increases the allowable input power and the corresponding local SAR, in one example up to 100 W/kg, without limiting the exposure time necessary for an MR examination.
In conclusion, the integrated antenna array at 7 T enables a clinical workflow for body imaging and comparable imaging performance to a conventional 3 T clinical body coil.
The aim of the current study was to investigate the performance of integrated RF
transmit arrays with high channel count consisting of meander microstrip antennas
for body imaging at 7 T and to optimize the position and number of transmit ele-
ments. RF simulations using multiring antenna arrays placed behind the bore liner
were performed for realistic exposure conditions for body imaging. Simulations were
performed for arrays with as few as eight elements and for arrays with high channel
counts of up to 48 elements. The B1+ field was evaluated regarding the degrees of
freedom for RF shimming in the abdomen. Worst-case specific absorption rate
(SARwc ), SAR overestimation in the matrix compression, the number of virtual obser-
vation points (VOPs) and SAR efficiency were evaluated. Constrained RF shimming
was performed in differently oriented regions of interest in the body, and the devia-
tion from a target B1+ field was evaluated. Results show that integrated multiring
arrays are able to generate homogeneous B1+ field distributions for large FOVs, espe-
cially for coronal/sagittal slices, and thus enable body imaging at 7 T with a clinical
workflow; however, a low duty cycle or a high SAR is required to achieve homoge-
neous B1+ distributions and to exploit the full potential. In conclusion, integrated
arrays allow for high element counts that have high degrees of freedom for the pulse
optimization but also produce high SARwc , which reduces the SAR accuracy in the
VOP compression for low-SAR protocols, leading to a potential reduction in array
performance. Smaller SAR overestimations can increase SAR accuracy, but lead to a
high number of VOPs, which increases the computational cost for VOP evaluation
and makes online SAR monitoring or pulse optimization challenging. Arrays with
interleaved rings showed the best results in the study.
7T MR Safety
(2021)
Bacterial cell appendix formation supports cell-cell interaction, cell adhesion and cell movement. Additionally, in bioelectrochemical systems (BES), cell appendages have been shown to participate in extracellular electron transfer. In this work, the cell appendix formation of Clostridium acetobutylicum in biofilms of a BES are imaged and compared with conventional biofilms. Under all observed conditions, the cells possess filamentous appendages with a higher number and density in the BES. Differences in the amount of extracellular polymeric substance in the biofilms of the electrodes lead to the conclusion that the cathode can be used as electron donor and the anode as electron acceptor by C. acetobutylicum. When using conductive atomic force microscopy, a current response of about 15 nA is found for the cell appendages from the BES. This is the first report of conductivity for clostridial cell appendices and represents the basis for further studies on their role for biofilm formation and electron transfer.
Erdbebennachweis von Mauerwerksbauten mit realistischen Modellen und erhöhten Verhaltensbeiwerten
(2021)
Die Anwendung des linearen Nachweiskonzepts auf Mauerwerksbauten führt dazu, dass bereits heute Standsicherheitsnachweise für Gebäude mit üblichen Grundrissen in Gebieten mit moderaten Erdbebeneinwirkungen nicht mehr geführt werden können. Diese Problematik wird sich in Deutschland mit der Einführung kontinuierlicher probabilistischer Erdbebenkarten weiter verschärfen. Aufgrund der Erhöhung der seismischen Einwirkungen, die sich vielerorts ergibt, ist es erforderlich, die vorhandenen, bislang nicht berücksichtigten Tragfähigkeitsreserven in nachvollziehbaren Nachweiskonzepten in der Baupraxis verfügbar zu machen. Der vorliegende Beitrag stellt ein Konzept für die gebäudespezifische Ermittlung von erhöhten Verhaltensbeiwerten vor. Die Verhaltensbeiwerte setzen sich aus drei Anteilen zusammen, mit denen die Lastumverteilung im Grundriss, die Verformungsfähigkeit und Energiedissipation sowie die Überfestigkeiten berücksichtigt werden. Für die rechnerische Ermittlung dieser drei Anteile wird ein nichtlineares Nachweiskonzept auf Grundlage von Pushover-Analysen vorgeschlagen, in denen die Interaktionen von Wänden und Geschossdecken durch einen Einspanngrad beschrieben werden. Für die Bestimmung der Einspanngrade wird ein nichtlinearer Modellierungsansatz eingeführt, mit dem die Interaktion von Wänden und Decken abgebildet werden kann. Die Anwendung des Konzepts mit erhöhten gebäudespezifischen Verhaltensbeiwerten wird am Beispiel eines Mehrfamilienhauses aus Kalksandsteinen demonstriert. Die Ergebnisse der linearen Nachweise mit erhöhten Verhaltensbeiwerten für dieses Gebäude liegen deutlich näher an den Ergebnissen nichtlinearer Nachweise und somit bleiben übliche Grundrisse in Erdbebengebieten mit den traditionellen linearen Rechenansätzen nachweisbar.
The development and analysis of three waveguides for the exposure of small biological in vitro samples to mobile communication signals at 900 MHz (GSM, Global System for Mobile Communications), 1.8 GHz (GSM), and 2 GHz (UMTS, Universal Mobile Telecommunications System) is presented. The waveguides were based on a fin-line concept and the chamber containing the samples bathed in extracellular solution was placed onto two fins with a slot in between, where the exposure field concentrates. Measures were taken to allow for patch clamp recordings during radiofrequency (RF) exposure. The necessary power for the achievement of the maximum desired specific absorption rate (SAR) of 20 W/kg (average over the mass of the solution) was approximately Pin = 50 mW, Pin = 19 mW, and Pin = 18 mW for the 900 MHz, 1800 MHz, and 2 GHz devices, respectively. At 20 W/kg, a slight RF-induced temperature elevation in the solution of no more than 0.3 °C was detected, while no thermal offsets due to the electromagnetic exposure could be detected at the lower SAR settings (2, 0.2, and 0.02 W/kg). A deviation of 10% from the intended solution volume yielded a calculated SAR deviation of 8% from the desired value. A maximum ±10% variation in the local SAR could occur when the position of the patch clamp electrode was altered within the area where the cells to be investigated were located.