Complex 3D microfluidic architectures formed by mechanically guided compressive buckling.

Microfluidic technologies have wide-ranging applications in chemical analysis systems, drug delivery platforms, and artificial vascular networks. This latter area is particularly relevant to 3D cell cultures, engineered tissues, and artificial organs, where volumetric capabilities in fluid distribution are essential. Existing schemes for fabricating 3D microfluidic structures are constrained in realizing desired layout designs, producing physiologically relevant microvascular structures, and/or integrating active electronic/optoelectronic/microelectromechanical components for sensing and actuation. This paper presents a guided assembly approach that bypasses these limitations to yield complex 3D microvascular structures from 2D precursors that exploit the full sophistication of 2D fabrication methods. The capabilities extend to feature sizes <5 μm, in extended arrays and with various embedded sensors and actuators, across wide ranges of overall dimensions, in a parallel, high-throughput process. Examples include 3D microvascular networks with sophisticated layouts, deterministically designed and constructed to expand the geometries and operating features of artificial vascular networks

The N-Terminal α-Helix of Potato Virus X-Encoded RNA-Dependent RNA Polymerase Is Required for Membrane Association and Multimerization

Positive-sense single-stranded RNA viruses replicate in virus-induced membranous organelles for maximum efficiency and immune escaping. The replication of potato virus X (PVX) takes place on the endoplasmic reticulum (ER); however, how PVX-encoded RNA-dependent RNA polymerase (RdRp) is associated with the ER is still unknown. A proline-kinked amphipathic α-helix was recently found in the MET domain of RdRp. In this study, we further illustrate that the first α-helix of the MET domain is also required for ER association. Moreover, we found that the MET domain forms multimers on ER and the first α-helix is essential for multimerization. These results suggest that the RdRp of PVX adopts more than one hydrophobic motif for membrane association and for multimerization

Genome-Wide Association Analysis of Cowpea Mild Mottle Virus Resistance in Soybean Germplasms from Northeast China

Cowpea mild mottle virus (CpMMV) is an important viral pathogen that seriously influences the yield and seed quality of soybeans worldwide. Resistance breeding is one of the most effective, economical, and environmentally safe strategies for controlling the disease caused by CpMMV. However, only few resistance genes have been identified in soybeans. In this study, the resistance of 169 soybean germplasms from Northeast China to a CpMMV strain isolated from soybean in China was evaluated, and a genome-wide association study (GWAS) was then performed to find possible resistance genes in these soybean germplasms. Nine resistant soybean germplasms were identified and two single nucleotide polymorphism sites (SNPs) were found to be closely associated with CpMMV resistance. A total number of 51 and 25 candidate genes neighboring the resistance-associated SNPs on chromosomes 6 and 12, respectively, were identified, among which one receptor-like kinase (RLK) on chromosome 6 and 2 toll-interleukin-1 receptor nucleotide-binding leucine-rich repeat receptors (TNLs) on chromosome 12 were recognized as the most probable resistance genes, respectively. Together, these data provide new insights on the resistance resources of soybeans to CpMMV, which will benefit the breeding of CpMMV-resistant soybean cultivars

A Wireless Near-Infrared Spectroscopy Device for Flap Monitoring: Proof of Concept in a Porcine Musculocutaneous Flap Model

Background Current near-infrared spectroscopy (NIRS)-based systems for continuous flap monitoring are highly sensitive for detecting malperfusion. However, the clinical utility and user experience are limited by the wired connection between the sensor and bedside console. This wire leads to instability of the flap-sensor interface and may cause false alarms. Methods We present a novel wearable wireless NIRS sensor for continuous fasciocutaneous free flap monitoring. This waterproof silicone-encapsulated Bluetooth-enabled device contains two light-emitting diodes and two photodetectors in addition to a battery sufficient for 5 days of uninterrupted function. This novel device was compared with a ViOptix T.Ox monitor in a porcine rectus abdominus myocutaneous flap model of arterial and venous occlusions. Results Devices were tested in four flaps using three animals. Both devices produced very similar tissue oxygen saturation (StO 2) tracings throughout the vascular clamping events, with obvious and parallel changes occurring on arterial clamping, arterial release, venous clamping, and venous release. Small interdevice variations in absolute StO 2 value readings and magnitude of change were observed. The normalized cross-correlation at zero lag describing correspondence between the novel NIRS and T.Ox devices was &gt;0.99 in each trial. Conclusion The wireless NIRS flap monitor is capable of detecting StO 2 changes resultant from arterial vascular occlusive events. In this porcine flap model, the functionality of this novel sensor closely mirrored that of the T.Ox wired platform. This device is waterproof, highly adhesive, skin conforming, and has sufficient battery life to function for 5 days. Clinical testing is necessary to determine if this wireless functionality translates into fewer false-positive alarms and a better user experience. Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.ChemE/Product and Process Engineerin

Freestanding 3D Mesostructures, Functional Devices, and Shape-Programmable Systems Based on Mechanically Induced Assembly with Shape Memory Polymers

Capabilities for controlled formation of sophisticated 3D micro/nanostructures in advanced materials have foundational implications across a broad range of fields. Recently developed methods use stress release in prestrained elastomeric substrates as a driving force for assembling 3D structures and functional microdevices from 2D precursors. A limitation of this approach is that releasing these structures from their substrate returns them to their original 2D layouts due to the elastic recovery of the constituent materials. Here, a concept in which shape memory polymers serve as a means to achieve freestanding 3D architectures from the same basic approach is introduced, with demonstrated ability to realize lateral dimensions, characteristic feature sizes, and thicknesses as small as ≈500, 10, and 5 µm simultaneously, and the potential to scale to much larger or smaller dimensions. Wireless electronic devices illustrate the capacity to integrate other materials and functional components into these 3D frameworks. Quantitative mechanics modeling and experimental measurements illustrate not only shape fixation but also capabilities that allow for structure recovery and shape programmability, as a form of 4D structural control. These ideas provide opportunities in fields ranging from micro-electromechanical systems and microrobotics, to smart intravascular stents, tissue scaffolds, and many others