Self‐Assembly of Wireframe DNA Nanostructures from Junction Motifs

Wireframe frameworks have been investigated for the construction of complex nanostructures from a scaffolded DNA origami approach; however, a similar framework is yet to be fully explored in a scaffold‐free “LEGO” approach. Herein, we describe a general design scheme to construct wireframe DNA nanostructures entirely from short synthetic strands. A typical edge of the resulting structures in this study is composed of two parallel duplexes with crossovers on both ends, and three, four, or five edges radiate out from a certain vertex. By using such a self‐assembly scheme, we produced planar lattices and polyhedral objects.Conjunction junction, what’s your function? Junction motifs of specific angle arrangements are designed. 2D wireframe lattices and 3D wireframe polyhedra are constructed accordingly.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151279/1/anie201906408-sup-0001-misc_information.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151279/2/anie201906408_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151279/3/anie201906408.pd

Self‐Assembly of Wireframe DNA Nanostructures from Junction Motifs

Wireframe frameworks have been investigated for the construction of complex nanostructures from a scaffolded DNA origami approach; however, a similar framework is yet to be fully explored in a scaffold‐free “LEGO” approach. Herein, we describe a general design scheme to construct wireframe DNA nanostructures entirely from short synthetic strands. A typical edge of the resulting structures in this study is composed of two parallel duplexes with crossovers on both ends, and three, four, or five edges radiate out from a certain vertex. By using such a self‐assembly scheme, we produced planar lattices and polyhedral objects.Verzweigte Angelegenheit: DNA‐Verzweigungsmotive mit Anordnungen in bestimmten Winkeln wurden entwickelt. Mit ihnen wurden zweidimensionale Drahtgitterstrukturen und dreidimensionale Polyeder konstruiert.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151370/1/ange201906408.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151370/2/ange201906408-sup-0001-misc_information.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151370/3/ange201906408_am.pd

Dynamical alterations of brain function and gut microbiome in weight loss

ObjectiveIntermittent energy restriction (IER) is an effective weight loss strategy. However, little is known about the dynamic effects of IER on the brain-gut-microbiome axis.MethodsIn this study, a total of 25 obese individuals successfully lost weight after a 2-month IER intervention. FMRI was used to determine the activity of brain regions. Metagenomic sequencing was performed to identify differentially abundant gut microbes and pathways in from fecal samples.ResultsOur results showed that IER longitudinally reduced the activity of obese-related brain regions at different timepoints, including the inferior frontal orbital gyrus in the cognitive control circuit, the putamen in the emotion and learning circuit, and the anterior cingulate cortex in the sensory circuit. IER longitudinally reduced E. coli abundance across multiple timepoints while elevating the abundance of obesity-related Faecalibacterium prausnitzii, Parabacteroides distasonis, and Bacterokles uniformis. Correlation analysis revealed longitudinally correlations between gut bacteria abundance alterations and brain activity changes.ConclusionsThere was dynamical alteration of BGM axis (the communication of E. coli with specific brain regions) during the weight loss under the IER

Dynamics of a Stick-Jump Contact Line of Water Drops on a Strip Surface

In this study, we prepared microscale periodic rough structures consisting of parallel strips on a silicon surface. The width of each strip was equal to the gap between the strips, and the silicon surface was silanized with perfluorooctyltrichlorosilane. We studied the wetting characteristics of water drops as they advanced and receded on patterned surfaces in a direction perpendicular to the strip. Water drops were observed to advance or recede in a smooth manner when the strip width was smaller than 32 mu m but in a stick-jump manner when the strip width was larger than 50 um. The regular strip-patterned substrates enabled us to deduce the relationship between the stick-jump behavior and the feature size of the substrate. For surfaces on which water drops showed stick-jump behavior, the oscillation amplitude of the contact angle decreased with decreasing strip width. In addition, the jumping distances of the contact lines, for both advancing and receding water drops, were nearly equal to the strip period. A 2D model was applied to analyze the contact line motion on the patterned surfaces, which showed reasonable agreement with the experimental results

Gradiently varied chain packing/orientation states of polymer thin films revealed by polarization-dependent infrared absorption

Gradiently varied chain packing/orientation states of the polyacrylamide (PAL) thin films spin-coated on the gold (Au) substrates were found via the polarized reflection-absorption Fourier transform infrared spectroscopy (RA-FTIR). As the film thickness increases, the splitted amide I bands provide a direct evidence that the PAL thin films are of a gradiently varied bi-layered structure. In the bottom layer, most of the PAL molecules show random orientation which is induced by the non-favorable interaction from the adjacent Au surface. In the top layer, most of PAL molecules show parallel orientation to the Au surface which is induced by spin coating, evidenced by the enhanced low-frequency splitted amide I band (similar to 1658 cm(-1)) and N-H stretching modes of the amino groups when the light electric field vector is adjusted to be parallel to the Au surface. The observation reported in this study should be of universal significance for polymer thin films on the supported substrates, where the interfacial interaction as well as spin coating could vary the polymer packing/orientation states substantially. (C) 2014 Elsevier Ltd. All rights reserved

DNA Nanotechnology and Computer Systems of Nucleic Acids

Structural DNA nanotechnology (SDN) has attracted the attention of scientists in different research fields. Motifs are designed for various purposes, such as drug delivery, capturing proteins, templates for DNA nanotechnology, etc. However, DNA motif design does not simply depend on physical models or the human imagination if the desired structure is complicated. Structuring and modeling by using fast-growing computer technologies are essential and desirable for the entire community. In this paper, we present a review of the current research in the field in terms of the structure of DNA, molecular modeling, and various computer programs aiming to design, analyze and evaluate nucleic acid structures, explain how they interact and predict the macrostructures formed by a number of molecular units in DNA nanotechnology

Simplifying the Process of Microalgal Biodiesel Production Through In Situ Transesterification Technology

Crop-based biofuels, including biodiesel, has sparked international concerns during recent years. Micro-algae have been strongly advocated as the most promising substitute for oil crops. However, the commercialization of microalgal biodiesel is hindered by the high costs of feed-stock and conventional production processes. This paper elucidates a simplified, scalable production process under conditions of least energetic demand, which integrates oil extraction and conversion into one step through in situ transesterification. Introducing a co-solvent is the key to success. Criteria for co-solvents applicable to the microalgal biodiesel industry are proposed. The overall biodiesel yield (OBY) of Spirulina was determined for benchmarking purposes, using the Bligh and Dyer protocol for oil extraction, and transesterification with potassium hydroxide. The performance in in situ transesterification of the selected co-solvents toluene, dichloromethane and diethyl ether, as well as the solvent combinations petroleum ether/toluene, toluene/methanol and dichloromethane/methanol, was evaluated by OBY. Among all the co-solvents tested, the toluene/methanol system, 2: 1 by volume ratio, demonstrated the highest efficiency, achieving a biodiesel yield of 76% of the OBY for the first in situ transesterification cycle and 10% for the second in situ transesterification cycle