Design of an IGBT-Based Pulsed Power Supply for Non-continuous-mode Electrospinning

Nanofibres are useful in a broad range of applications in areas such as medical science, food science, materials engineering, environmental engineering, and energy and electronics due to their outstanding characteristics: their small size, high surface-to-volume ratio, high porosity, and superior mechanical performance. Recently, controlled drug delivery systems have gained significant attention, especially with respect to the use of polymer nanofibres. For these systems, the ability to control of the length of the polymer nanofibre is important because the amount of drug released depends on the length of the fibre. Electrospinning is the simplest and most cost-effective method of fabricating polymer nanofibres. In the process, a high voltage is used to create an electrified jet which will eventually become a nanofibre. The electrified jet ejects when a high voltage is applied to the electrospinning setup. On the other hand, the jet does not eject when the applied voltage is below the threshold voltage. It is therefore possible to fabricate and chop nanofibres by controlling the values of the voltages applied and a special high-voltage pulsed power supply has been developed for this purpose. In this research, an IGBT-based pulsed power supply has been designed and built to be used for non-continuous-mode electrospinning. The IGBTs are connected in series to deliver high voltage pulse voltages to an electrospinning setup. The IGBT-based pulsed power supply is capable of producing controllable square pulses with a width of a few hundred microseconds to DC and amplitudes up to 10 kV. The technique of non-continuous-mode electrospinning was tested using the pulsed power supply designed in this work. The new system was able to fabricate and chop nanofibres with PEO and alginate/PEO solutions. It was concluded that the minimum pulse width that can initiate an electrified jet is approximately 80 ms for the parameters used in this study. A longer period produces a more constant jet during the pulse-on voltage when the duty ratio is the same value. It is also highly likely that a jet is always ejected during the pulse-on voltage when the duty ratio is more than 40 %

An experimental framework for designing document structure for users' decision making -- An empirical study of recipes

Textual documents need to be of good quality to ensure effective asynchronous communication in remote areas, especially during the COVID-19 pandemic. However, defining a preferred document structure (content and arrangement) for improving lay readers' decision-making is challenging. First, the types of useful content for various readers cannot be determined simply by gathering expert knowledge. Second, methodologies to evaluate the document's usefulness from the user's perspective have not been established. This study proposed the experimental framework to identify useful contents of documents by aggregating lay readers' insights. This study used 200 online recipes as research subjects and recruited 1,340 amateur cooks as lay readers. The proposed framework identified six useful contents of recipes. Multi-level modeling then showed that among the six identified contents, suitable ingredients or notes arranged with a subheading at the end of each cooking step significantly increased recipes' usefulness. Our framework contributes to the communication design via documents

Inhibition of KDM1A activity restores adult neurogenesis and improves hippocampal memory in a mouse model of Kabuki syndrome.

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked DownloadKabuki syndrome (KS) is a rare cause of intellectual disability primarily caused by loss-of-function mutations in lysine-specific methyltransferase 2D (KMT2D), which normally adds methyl marks to lysine 4 on histone 3. Previous studies have shown that a mouse model of KS (Kmt2d +/βGeo ) demonstrates disruption of adult neurogenesis and hippocampal memory. Proof-of-principle studies have shown postnatal rescue of neurological dysfunction following treatments that promote chromatin opening; however, these strategies are non-specific and do not directly address the primary defect of histone methylation. Since lysine-specific demethylase 1A (LSD1/KDM1A) normally removes the H3K4 methyl marks added by KMT2D, we hypothesized that inhibition of KDM1A demethylase activity may ameliorate molecular and phenotypic defects stemming from KMT2D loss. To test this hypothesis, we evaluated a recently developed KDM1A inhibitor (TAK-418) in Kmt2d +/βGeo mice. We found that orally administered TAK-418 increases the numbers of newly born doublecortin (DCX)+ cells and processes in the hippocampus in a dose-dependent manner. We also observed TAK-418-dependent rescue of histone modification defects in hippocampus both by western blot and chromatin immunoprecipitation sequencing (ChIP-seq). Treatment rescues gene expression abnormalities including those of immediate early genes such as FBJ osteosarcoma oncogene (Fos) and FBJ osteosarcoma oncogene homolog B (Fosb). After 2 weeks of TAK-418, Kmt2d +/βGeo mice demonstrated normalization of hippocampal memory defects. In summary, our data suggest that KDM1A inhibition is a plausible treatment strategy for KS and support the hypothesis that the epigenetic dysregulation secondary to KMT2D dysfunction plays a major role in the postnatal neurological disease phenotype in KS.United States Department of Health & Human Services National Institutes of Health (NIH) - USA Louma G. Foundation, USA Walter Zaitzeff Fund, USA Icelandic Research Fund, Iceland Takeda Pharmaceutical Company Lt

Cell-to-Cell Transformation in Escherichia coli: A Novel Type of Natural Transformation Involving Cell-Derived DNA and a Putative Promoting Pheromone

Escherichia coli is not assumed to be naturally transformable. However, several recent reports have shown that E. coli can express modest genetic competence in certain conditions that may arise in its environment. We have shown previously that spontaneous lateral transfer of non-conjugative plasmids occurs in a colony biofilm of mixed E. coli strains (a set of a donor strain harbouring a plasmid and a plasmid-free recipient strain). In this study, with high-frequency combinations of strains and a plasmid, we constructed the same lateral plasmid transfer system in liquid culture. Using this system, we demonstrated that this lateral plasmid transfer was DNase-sensitive, indicating that it is a kind of transformation in which DNase-accessible extracellular naked DNA is essential. However, this transformation did not occur with purified plasmid DNA and required a direct supply of plasmid from co-existing donor cells. Based on this feature, we have termed this transformation type as ‘cell-to-cell transformation’. Analyses using medium conditioned with the high-frequency strain revealed that this strain released a certain factor(s) that promoted cell-to-cell transformation and arrested growth of the other strains. This factor is heat-labile and protease-sensitive, and its roughly estimated molecular mass was between ∼9 kDa and ∼30 kDa, indicating that it is a polypeptide factor. Interestingly, this factor was effective even when the conditioned medium was diluted 10–5–10–6, suggesting that it acts like a pheromone with high bioactivity. Based on these results, we propose that cell-to-cell transformation is a novel natural transformation mechanism in E. coli that requires cell-derived DNA and is promoted by a peptide pheromone. This is the first evidence that suggests the existence of a peptide pheromone-regulated transformation mechanism in E. coli and in Gram-negative bacteria

Evaluation of the Reconstruction Parameters of Brain Dopamine Transporter SPECT Images Obtained by a Fan Beam Collimator: A Comparison with Parallel-hole Collimators

Objective(s): The purpose of this study was to examine the optimal reconstructionparameters for brain dopamine transporter SPECT images obtained with a fanbeam collimator and compare the results with those obtained by using parallel-holecollimators.Methods: Data acquisition was performed using two SPECT/CT devices, namely aSymbia T6 and an Infinia Hawkeye 4 (device A and B) equipped with fan-beam(camera A-1 and B-1), low- and medium-energy general-purpose (camera A-2 andB-2), and low-energy high-resolution (camera A-3 and B-3) collimators. The SPECTimages were reconstructed using filtered back projection (FBP) with Chang’sattenuation correction. However, the scatter correction was not performed. A poolphantom and a three-dimensional (3D) brain phantom were filled with 123I solution toexamine the reconstruction parameters. The optimal attenuation coefficient wasbased on the visual assessment of the profile curve, coefficient of variation (CV) [%],and summed difference from the reference activity of the pool phantom. The optimalButterworth filter for the 3D-brain phantom was also determined based on a visualassessment. The anthropomorphic striatal phantom was filled with 123I solution atstriatum-to-background radioactivity ratios of 8, 6, 4, and 3. The specific binding ratio(SBR) of the striatum (calculated by the CT method) was used to compare the resultswith those of the parallel-hole collimators.Results: The optimal attenuation coefficients were 0.09, 0.11, 0.05, 0.05, 0.11, and, 0.10cm-1 for cameras A-1, A-2, A-3, B-1, B-2, and B-3, respectively. The cutoff frequencies ofthe Butterworth filter were 0.32, 0.40, and 0.36 cycles/cm for camera A, and 0.46, 0.44,and 0.44 cycles/cm for camera B, respectively. The recovery rates of the SBRmean withcamera A were 51.2%, 49.4%, and 45.6%, respectively. The difference was notstatistically significant. The recovery rates of the SBR with camera B were 59.2%,50.7%, and 50.8%, respectively. Camera B-1 showed significantly high SBR values.Conclusion: As the findings indicated, the optimal reconstruction parameters differedaccording to the devices and collimators. The fan beam collimator was found toprovide promising results with each device

Purification of human papillomavirus-like particles expressed in silkworm using a Bombyx mori nucleopolyhedrovirus bacmid expression system

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Datenschutz-Folgenabschätzung: Chancen, Grenzen, Umsetzung

With the European General Data Protection Regulation (GDPR) there will be a legal obligation for controllers to conduct a Data Protection Impact Assessment (DPIA) for the first time. This paper examines the new provisions in detail and examines ways for their implementation. A special focus is on elements which, according to experience, can be problematic and how they can be addressed