773 research outputs found
Investigation of the interaction between the MIR-503 and CD40 genes in irradiated U937 cells
<p>Abstract</p> <p>Background</p> <p>MicroRNAs (miRNAs) are a group of small noncoding RNAs that take part in diverse biological processes by suppressing target gene expression. Relatively few miRNAs have been studied in detail, especially miR-503, and hence the biological relevance of majority remains to be uncovered. Whether altered expression of miRNA-503 affects the immunity response to radiotherapy has yet to be addressed.</p> <p>Results</p> <p>In the present study, we applied ionizing radiation with a dose of either 0.1 Gy or 5 Gy to irradiate U937 cells to confirm CD40 as a miR-503 target, which was identified using a bioimformatics tool. In high dose (5 Gy) ionizing-irradiated U937 cells, expression of miR-503 was up regulated while the expression of CD40 gene was down regulated. Using the transfection of the miR-503 gene into U937 cells and Luciferase assay, we confirmed that miR-503 suppressed the expression of CD40, and was a negtive regulator of CD40.</p> <p>Conclusions</p> <p>To our knowledge, we are the first to describe involvement of miR-503 in radiobiological effect at a molecular level. This initial finding suggested the evidence that ionizing radiation could alter the expression of miR-503 and its target gene CD40, and may be very important to shed light on a possible mechanism regarding regulation of immune responses to irradiation.</p
Modeling and identification of the dynamic behavior of stranded wire helical springs
A stranded wire helical spring is a cylindrical helical spring wound by a wire strand. Owing to its unique structure, the spring features special dynamic behavior such as nonlinear stiffness, hysteresis and hardening overlap. The dynamic response model, which gives an accurate description of the dynamic behavior, of the spring is a very important tool for designing systems using the spring as well as evaluating the responses of such systems. However, no accurate model has been reported. In the present study, a modified normalized Bouc-Wen model is proposed to model the dynamic behavior of the spring. A simple yet effective identification method is developed for identifying the model parameters using experimental data. Numerical simulations and periodic loading experiments were carried out to validate the proposed model and identification method. The results verify that the proposed model and method are effective for modeling and identifying the dynamic behavior of stranded wire helical springs
Molecular basis for heat desensitization of TRPV1 ion channels.
The transient receptor potential vanilloid 1 (TRPV1) ion channel is a prototypical molecular sensor for noxious heat in mammals. Its role in sustained heat response remains poorly understood, because rapid heat-induced desensitization (Dh) follows tightly heat-induced activation (Ah). To understand the physiological role and structural basis of Dh, we carried out a comparative study of TRPV1 channels in mouse (mV1) and those in platypus (pV1), which naturally lacks Dh. Here we show that a temperature-sensitive interaction between the N- and C-terminal domains of mV1 but not pV1 drives a conformational rearrangement in the pore leading to Dh. We further show that knock-in mice expressing pV1 sensed heat normally but suffered scald damages in a hot environment. Our findings suggest that Dh evolved late during evolution as a protective mechanism and a delicate balance between Ah and Dh is crucial for mammals to sense and respond to noxious heat
Two-Terminal manipulation of masses:application to vibration isolation of passive suspensions
A typical mass has only one genuine terminal, through which the mass interacts a position and a force vector with the environment. This paper proposes an innovative twoterminal manipulation approach for typical masses, such as mass blocks and flywheels, so as to upgrade its topology. A prototype device of the two-terminal mass is developed for testing. The experimental result validates its free two-terminal inertial dynamic characteristics. The twoterminal mass is then applied to vibration isolation of the passive suspension. The simulation result shows that, due to the presence of the second genuine terminal, the two-terminal mass contributes the suspension better isolation performance. The presented approach provides masses more extensive applications to vibration system
The Snowflake Hypothesis: Training Deep GNN with One Node One Receptive field
Despite Graph Neural Networks demonstrating considerable promise in graph
representation learning tasks, GNNs predominantly face significant issues with
over-fitting and over-smoothing as they go deeper as models of computer vision
realm. In this work, we conduct a systematic study of deeper GNN research
trajectories. Our findings indicate that the current success of deep GNNs
primarily stems from (I) the adoption of innovations from CNNs, such as
residual/skip connections, or (II) the tailor-made aggregation algorithms like
DropEdge. However, these algorithms often lack intrinsic interpretability and
indiscriminately treat all nodes within a given layer in a similar manner,
thereby failing to capture the nuanced differences among various nodes. To this
end, we introduce the Snowflake Hypothesis -- a novel paradigm underpinning the
concept of ``one node, one receptive field''. The hypothesis draws inspiration
from the unique and individualistic patterns of each snowflake, proposing a
corresponding uniqueness in the receptive fields of nodes in the GNNs.
We employ the simplest gradient and node-level cosine distance as guiding
principles to regulate the aggregation depth for each node, and conduct
comprehensive experiments including: (1) different training schemes; (2)
various shallow and deep GNN backbones, and (3) various numbers of layers (8,
16, 32, 64) on multiple benchmarks (six graphs including dense graphs with
millions of nodes); (4) compare with different aggregation strategies. The
observational results demonstrate that our hypothesis can serve as a universal
operator for a range of tasks, and it displays tremendous potential on deep
GNNs. It can be applied to various GNN frameworks, enhancing its effectiveness
when operating in-depth, and guiding the selection of the optimal network depth
in an explainable and generalizable way
Is ChatGPT Equipped with Emotional Dialogue Capabilities?
This report presents a study on the emotional dialogue capability of ChatGPT,
an advanced language model developed by OpenAI. The study evaluates the
performance of ChatGPT on emotional dialogue understanding and generation
through a series of experiments on several downstream tasks. Our findings
indicate that while ChatGPT's performance on emotional dialogue understanding
may still lag behind that of supervised models, it exhibits promising results
in generating emotional responses. Furthermore, the study suggests potential
avenues for future research directions
Synthesis and Antitumor Activity of N-Triazol-5-yl-oxazolidin-4-one Derivatives.
Fifteen novel N-triazol-5-yl-oxazolidin-4-ones were synthesized through a few of steps from the benzaldehydes. It was found that N-iodosuccinimide (NIS) can promote intramolecular amination reaction which is the key step of the syntheses, which will be used as new method for the intramolecular formation of nitrogen-containing heterocycles. Part of the compounds were evaluated for their anticancer activity. Among them, compounds 6a, 6b and 6c showed moderate antiprolifiration activity toward human breast cancer cells MDA-MB-231 cell lines, while the mild activity of 6a, 6b and 6d against human cervical cancer HeLa cell lines was confirmed in vitro assay
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