Melt differential centrifugal electrospinning (MDCE) method is proposed by integrating the advantages of centrifugal spinning and melt differential electrospinning, including high efficiency, solvent-free, multiple jets formation from nozzle-less spinning system, and small diameter. A mathematical model of jet diameter in MDCE is established. An orthogonal experiment is carried out to explore the effects of main processing parameters on the average diameter and the diameter standard deviation of the prepared fibers. Ultimately, polypropylene (PP) nanofibers with an average diameter of 790 nm are successfully prepared in a higher flow rate of 124.26 g h −1 than that of other methods. The X-ray diffraction and differential scanning calorimeter indicate that the introduction of high-voltage electrostatic field in centrifugal spinning contribute to the crystal orientation of the PP molecular chain. Therefore, tensile mechanical strength is enhanced as the increase of the loading voltage. MDCE may provide an efficient and eco-friendly method for nanofiber manufacturing in the future.

Aim: Active changes in neuronal DNA methylation and demethylation appear to act as controllers of synaptic scaling and glutamate receptor trafficking in learning and memory formation. DNA methyltransferases (DNMTs), including proteins encoded by Dnmt1, Dnmt3a and Dnmt3b, are dominant enzymes carrying out DNA methylation. Our previous study demonstrated the important roles that DNMT1 and DNMT3a play in synaptic function and memory. In this study, we aim to explore the role of DNMT3b and its-mediated DNA methylation in memory processes. Methods: Dnmt3b was knocked down specifically in dorsal CA1 neurons of adult mice hippocampus by AAV-syn-Cre-GFP virus injection. Behavioral tests were used to evaluate memory performance. Gene expression microarray analysis followed by quantitative RT-PCR were performed to find differential expression genes. Results: Dnmt3b flox/flox mice receiving Cre-virus infection showed impaired novel object-place recognition (NPR) and normal novel object recognition (NOR), in comparison to mice receiving control GFP-virus infection. Microarray analysis revealed differential expression of K + channel subunits in the hippocampus of Dnmt3b flox/flox mice receiving Cre-virus injection. Increased Kcne2 expression was confirmed by following qRT-PCR analysis. We also found that NPR training and testing induced up-regulation of hippocampal Dnmt1 and Dnmt3a mRNA expression in control mice, but not in Cre-virus injected mice. Our findings thus demonstrate that conditional Dnmt3b deletion in a subregion of the hippocampus impairs a specific form of recognition memory that is hippocampus-dependent.

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A label-free potentiometric aptasensing platform was designed for detection of carcinoembryonic antigen on a graphene oxide-modified electrode coupling with target recycling-assisted signal amplification.