Microfluidic chips for cells capture using 3-D hydrodynamic structure array

Microfluidic chips were designed and fabricated to capture cells in a relative small volume to generate the desired concentration needed for analysis. The microfluidic chips comprise three-dimensional (3-D) cell capture structures array fabricated in PDMS. The capture structure includes two layers. The first layer consists of spacers to create small gap between the upper layer and glass. The second layer is a sharp corner U-shaped compartment with sharp corners at the fore-end. And another type capture structure with Y-shaped fluidic guide has been designed. It was demonstrated that the structures can capture cells in theory, using Darcy–Weisbach equation and COMSOL Multiphysics. Then yeast cell was chosen to test the performance of the chips. The chip without fluid guides captured ~1.44 × 10⁵ cells and the capture efficiency was up to 71 %. And the chip with fluid guides captured ~5.0 × 10⁴ cells and the capture efficiency was ~25 %. The chip without fluid guides can capture more cells because the yeast cells in the chip without fluid guides are subject to larger hydrodynamic drag force.     

A MEMS‐based heating holder for the direct imaging of simultaneous in‐situ heating and biasing experiments in scanning/transmission electron microscopes

The introduction of scanning/transmission electron microscopes (S/TEM) with sub‐Angstrom resolution as well as fast and sensitive detection solutions support direct observation of dynamic phenomena in‐situ at the atomic scale. Thereby, in‐situ specimen holders play a crucial role: accurate control of the applied in‐situ stimulus on the nanostructure combined with the overall system stability to assure atomic resolution are paramount for a successful in‐situ S/TEM experiment. For those reasons, MEMS‐based TEM sample holders are becoming one of the preferred choices, also enabling a high precision in measurements of the in‐situ parameter for more reproducible data. A newly developed MEMS‐based microheater is presented in combination with the new NanoEx?‐i/v TEM sample holder. The concept is built on a four‐point probe temperature measurement approach allowing active, accurate local temperature control as well as calorimetry. In this paper, it is shown that it provides high temperature stability up to 1,300°C with a peak temperature of 1,500°C (also working accurately in gaseous environments), high temperature measurement accuracy (<4%) and uniform temperature distribution over the heated specimen area (<1%), enabling not only in‐situ S/TEM imaging experiments, but also elemental mapping at elevated temperatures using energy‐dispersive X‐ray spectroscopy (EDS). Moreover, it has the unique capability to enable simultaneous heating and biasing experiments. Microsc. Res. Tech. 79:239–250, 2016. © 2016 Wiley Periodicals, Inc.     

Competitive and sustainable manufacturing by means of ultra-efficient factories in urban surroundings

The rapid growth of the world population, the finiteness of resources on our planet Earth and the ongoing tendency towards urbanisation result in the need to question our actions and economic activities, also for industrial enterprises. A paradigm shift to decouple growth and resource utilisation is needed. By means of ultra-efficiency, factories are targeted, whose positive impact to their surrounding is optimised instead of only minimising negative influences. In the contribution, the concept of ultra-efficient factories and first tools for their implementation are introduced. Therefore, the term ultra-efficient factory is defined based on the state of the art. On this definition, spheres of activity for ultra-efficient factories under consideration of urban surroundings are determined. For the spheres of activity, criteria to assess the according maturity of companies are identified and aggregated into a comprehensive maturity model. The maturity model enables the determination of potentials for advancements of companies. To support the industrial application of the theoretic work, industrial best practices are determined and a visual tool is developed.     

3D CFD simulation of bottle emptying processes

A 3D Computational Fluid Dynamics (CFD) approach is used to investigate the effect of parameters such as bottle geometry, surface tension, or inclination on bottle emptying processes. The method can e.g. be used to assess changes of bottle emptying times induced by new bottle shapes, and it is shown to be much more accurate than existing empirical models. While expensive commercial CFD software has substantially restricted and hindered the use of this method in the past, our approach is based on freely available open source CFD software and hence accessible to everyone.     

Amphiphilic polymer conetworks derived from aqueous solutions for biocatalysis in organic solvents

Activating enzymes in organic solvents is of great interest in current biotechnology. Amphiphilic conetworks have been shown to activate entrapped enzyme molecules in such media. Although successful, the loading of such conetworks is limited by the diffusion of protein molecules. In order to overcome this, we designed a new polyoxazoline-based polymer conetwork that allows the enzyme entrapment during the preparation. To this end, new polymer conetwork soft scaffolds derived from more hydrophilic poly(2-hydroxyethyl acrylate) (PHEA) and more hydrophobic, telechelic poly(2-ethyl-1,3-oxazoline) (PEtOx) were prepared as free-standing membranes. The transparent, nanophasic polymer conetworks showed a selective swelling in aqueous and organic solvents. The enzyme lipase was entrapped by dissolving it in the prepolymer mixture followed by photopolymerization. Compared to the literature known PHEA-l-PDMS systems a 6-fold higher specific activity and a 8-fold higher conetwork activity in organic solvents were obtained. Thus, the novel PHEA-l-PEtOx conetworks are outstanding materials for entrapping and activating enzymes in organic solvents.     

Datenschutzrechtliche Aspekte bei der weitergabe von IP-Adressen

Im Alltag eines Administrators werden rund um den Betrieb von Web- und E-Mail-Servern in vielerlei Hinsicht IP-Adressen gespeichert oder sogar an Dritte übermittelt. H?ufig übersehen oder gar wissentlich übergangen wird dabei die inzwischen kaum mehr umstrittene Tatsache, dass es sich bei IP-Adressen um personenbezogene Daten handelt, die unter die Regeln des Datenschutzes fallen. Aber welche konkreten technischen und rechtlichen Konsequenzen hat diese Einordnung, insbesondere wenn die Daten an Dritte weitergegeben werden?     

GI,biliary tract and pancreas

Percutaneous stent-grafting is increasingly employed as a less invasive alternative to surgery for the treatment of infrarenal abdominal aortic aneurysms. It requires long-term imaging follow-up, to document the structural integrity of the device, to exculude perigraft channels and endograft leakages, as well as the shrinkage of the aneurysmal sac. The expectation of severe stent induced artifacts and safety concerns have prevented 3D MRA from being used. The purpose of this in vitro study was to investigate the imaging characteristics of a bifurcated stent graft with 3D MRA (3D Frourier transform fast spoiled GRE) at 1.5 T in comparison to those of CTA. Measurement of the stent wall thickness and luminal diameter were made on a agar gel embedded stent graft at five locations on both CTA and MRA images. The stent graft was depicted as a dark ring on MR images. Wall thickness measurments at the five locations of the stent graft overestimated the true stent thickness, while luminal diameters were slightly underestimated. Measurement differences between MR and CT were not statistically significant (P=0.67;P=0.85). Artifacts emanating from the platinum markers were considerably less severe on the MR-images. A wider area of signal loss was seen only at the insertion of the iliac stent leg into the aortic stent portion due to the overlap of two radio-opaque platinum markers. 3D MRA images should permit a comprehensive assessment of the arterial lumen, and of perivascular tissues.