Psybrackets, Pseudoknots and Singular Knots

We introduce algebraic structures known as psybrackets and use them to define invariants of pseudoknots and singular knots and links. Psybrackets are Niebrzydowski tribrackets with additional structure inspired by the Reidemeister moves for pseudoknots and singular knots. Examples and computations are provided.Comment: 12 page

Laboratory information management system for COVID-19 non-clinical efficacy trial data

Background : As the number of large-scale studies involving multiple organizations producing data has steadily increased, an integrated system for a common interoperable format is needed. In response to the coronavirus disease 2019 (COVID-19) pandemic, a number of global efforts are underway to develop vaccines and therapeutics. We are therefore observing an explosion in the proliferation of COVID-19 data, and interoperability is highly requested in multiple institutions participating simultaneously in COVID-19 pandemic research. Results : In this study, a laboratory information management system (LIMS) approach has been adopted to systemically manage various COVID-19 non-clinical trial data, including mortality, clinical signs, body weight, body temperature, organ weights, viral titer (viral replication and viral RNA), and multiorgan histopathology, from multiple institutions based on a web interface. The main aim of the implemented system is to integrate, standardize, and organize data collected from laboratories in multiple institutes for COVID-19 non-clinical efficacy testings. Six animal biosafety level 3 institutions proved the feasibility of our system. Substantial benefits were shown by maximizing collaborative high-quality non-clinical research. Conclusions : This LIMS platform can be used for future outbreaks, leading to accelerated medical product development through the systematic management of extensive data from non-clinical animal studies.This research was supported by the National research foundation of Korea(NRF) grant funded by the Korea government(MSIT) (2020M3A9I2109027 and 2021M3H9A1030260)

Effects of diluents on the lifted flame characteristics in laminar nonpremixed coflow propane jets

The effects of diluents including CO2, N-2 , and He on the lifted flame characteristics of laminar coflow propane jets are experimentally investigated by measuring their liftoff heights, H-L, and visualizing flow fields with oil mist. For lifted flames at a specified diluent mole fraction, X-D, H-L increases in the order of He, N-2 , CO2 when the diluent is added to the coflow stream. However, the order of HL becomes opposite when the diluent is added to the fuel stream. In addition, HL increases with increasing X-D for all cases. From the visualization of nonreacting flow fields, it is found that the negative buoyancy represented by the density difference between the fuel jet and the coflow induces a stagnation flow near the fuel nozzle by decelerating the fuel jet. As such, the lifted flame is found to be stabilized further upstream with increasing negative buoyancy. In addition to the buoyancy effect, the effects of diluents on H-L via the edge flame speed of the lifted flames, Se, are estimated by evaluating the laminar burning velocity, S-L(0) . Among the dilution, thermal, and chemical effects, the dilution effect is found to be dominant in reducing S-L(0) for all cases, while the chemical effect is negligible. Finally, a correlation for H-L is formulated using the ratios of the positive to negative buoyancy and the fuel jet velocity, U-0 , to S-L(n) , which shows a satisfactory agreement with the experimental data. (C) 2020 The Combustion Institute. Published by Elsevier Inc. All rights reserved

A Systems Biology Approach to Investigating the Interaction between Serotonin Synthesis by Tryptophan Hydroxylase and the Metabolic Homeostasis

Obesity has become a global public health and economic problem. Obesity is a major risk factor for a number of complications, such as type 2 diabetes, cardiovascular disease, fatty liver disease, and cancer. Serotonin (5-hydroxytryptamine [5-HT]) is a biogenic monoamine that plays various roles in metabolic homeostasis. It is well known that central 5-HT regulates appetite and mood. Several 5-HT receptor agonists and selective serotonin receptor uptake inhibitors (SSRIs) have shown beneficial effects on appetite and mood control in clinics. Although several genetic polymorphisms related to 5-HT synthesis and its receptors are strongly associated with obesity, there is little evidence of the role of peripheral 5-HT in human metabolism. In this study, we performed a systemic analysis of transcriptome data from the Genotype-Tissue Expression (GTEX) database. We investigated the expression of 5-HT and tryptophan hydroxylase (TPH), the rate-limiting enzyme of 5-HT biosynthesis, in the human brain and peripheral tissues. We also performed differential gene expression analysis and predicted changes in metabolites by comparing gene expressions of tissues with high TPH expression to the gene expressions of tissues with low TPH expression. Our analyses provide strong evidence that serotonin plays an important role in the regulation of metabolic homeostasis in humans

Bio-inspired hollow PDMS sponge for enhanced oil-water separation

Oil spills from disasters such as the sinking of ships and the discharge of oily wastes cause serious environmental problems. Polydimethylsiloxane(PDMS) sponges are valuable tools for isolating spilled oil. Here, we propose new PDMS sponges with bio-inspired design and enhanced absorption capacities. 3D printing was used to produce templates having negative designs, and after being filled with PDMS, the templates were selectively dissolved. Through this, PDMS sponges with well-interconnected and controlled porosities were produced within 10% error. The wettability of sponges with various pore sizes and line widths was investigated. The surfaces were found to be highly hydrophobic, with water contact angles of 100-143??, and oleophilic, with oil contact angles of ???0??. The sponge fabricated with line width of 200 ??m and pore size of 400 ??m showed the highest hydrophobicity and oleophilicity. These parameters were used to produce the surfaces of hollow sponges having bio-inspired design that mimics the water absorption and storage functions of cactus. Repeated oil-water separation testing was conducted, and the absorption capacities were compared with those of non-hollow and conventional sponges. The new design showed absorption capacity up to 3.7 times that of the sponges. The bio-inspired PDMS sponge provides a significant advance in oil-water separation ability

A Systems Biology Approach to Investigating the Interaction between Serotonin Synthesis by Tryptophan Hydroxylase and the Metabolic Homeostasis

Obesity has become a global public health and economic problem. Obesity is a major risk factor for a number of complications, such as type 2 diabetes, cardiovascular disease, fatty liver disease, and cancer. Serotonin (5-hydroxytryptamine [5-HT]) is a biogenic monoamine that plays various roles in metabolic homeostasis. It is well known that central 5-HT regulates appetite and mood. Several 5-HT receptor agonists and selective serotonin receptor uptake inhibitors (SSRIs) have shown beneficial effects on appetite and mood control in clinics. Although several genetic polymorphisms related to 5-HT synthesis and its receptors are strongly associated with obesity, there is little evidence of the role of peripheral 5-HT in human metabolism. In this study, we performed a systemic analysis of transcriptome data from the Genotype-Tissue Expression (GTEX) database. We investigated the expression of 5-HT and tryptophan hydroxylase (TPH), the rate-limiting enzyme of 5-HT biosynthesis, in the human brain and peripheral tissues. We also performed differential gene expression analysis and predicted changes in metabolites by comparing gene expressions of tissues with high TPH expression to the gene expressions of tissues with low TPH expression. Our analyses provide strong evidence that serotonin plays an important role in the regulation of metabolic homeostasis in humans

A fully automated immunoassay from whole blood on a disc

A portable, disc-based, and fully automated enzyme-linked immuno-sorbent assay (ELISA) system is developed to test infectious diseases from whole blood. The innovative laser irradiated ferrowax microvalves and centrifugal microfluidics were utilized for the full integration of microbead-based suspension ELISA assays on a disc starting from whole blood. The concentrations of the antigen and the antibody of Hepatitis B virus (HBV), HBsAg and Anti-HBs respectively, were measured using the lab-on-a-disc (LOD). All the necessary reagents are preloaded on the disc and the total process of the plasma separation, incubation with target specific antigen or antibody coated microbeads, multiple steps of washing, enzyme reaction with substrates, and the absorbance detection could be finished within 30 minutes. Compared to the conventional ELISA, the operation time was dramatically reduced from over 2 hours to less than 30 minutes while the limit of detection was kept similar; e. g. the limit of detection of Anti-HBs tests were 8.6 mIU mL(-1) and 10 mIU mL(-1) for the disc-based and the conventional ELISA respectively.close11011

Effect of temporal interference electrical stimulation on phasic dopamine release in the striatum

Background: Temporal interference stimulation (TIS) is a neuromodulation technique that could stimulate deep brain regions by inducing interfering electrical signals based on high-frequency electrical stimulations of multiple electrode pairs from outside the brain. Despite numerous TIS studies, however, there has been limited investigation into the neurochemical effects of TIS. Objective: We performed two experiments to investigate the effect of TIS on the medial forebrain bundle (MFB)-evoked phasic dopamine (DA) response. Methods: In the first experiment, we applied TIS next to a carbon fiber microelectrode (CFM) to examine the modulation of the MFB-evoked phasic DA response in the striatum (STr). Beat frequencies and intensities of TIS were 0, 2, 6, 10, 20, 60, 130 Hz and 0, 100, 200, 300, 400, 500 μA. In the second experiment, we examined the effect of TIS with a 2 Hz beat frequency (based on the first experiment) on MFB-evoked phasic DA release when applied above the cortex (with a simulation-based stimulation site targeting the striatum). We employed 0 Hz and 2 Hz beat frequencies and a control condition without stimulation. Results: In the first experiment, TIS with a beat frequency of 2 Hz and an intensity of 400 μA or greater decreased MFB-evoked phasic DA release by roughly 40%, which continued until the experiment's end. In contrast, TIS at beat frequencies other than 2 Hz and intensities less than 400 μA did not affect MFB-evoked phasic DA release. In the second experiment, TIS with a 2 Hz beat frequency decreased only the MFB-evoked phasic DA response, but the reduction in DA release was not sustained. Conclusions: STr-applied and cortex-applied TIS with delta frequency dampens evoked phasic DA release in the STr. These findings demonstrate that TIS could influence the neurochemical modulation of the brain