152 research outputs found

    High Pressure Raman Spectroscopy of 4-Azidobenzoic Acid

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    With the rapid development of science and technology, people’s demand for energy materials is increasing, and researchers’ exploration of energy materials is also more and more in-depth. Azide is a kind of nitrogen rich energetic material. In recent years, the research on azide mainly focuses on the synthesis of polynitrogen under the condition of changing pressure. This is because under the action of pressure, the azide group in the azide will hybridize the electronic orbit, and the adjacent azide groups will re combine in the form of single bond, so azide is considered to be an ideal precursor for the synthesis of polynitrogen under high pressure. In this paper, the Raman spectra of 4-azidobenzoic acid at ambient pressure were analyzed, the high-pressure Raman spectra of 4-azidobenzoic acid were measured, and the phase transition of 4-azidobenzoic acid under high pressure was discovered

    An evaluation method for corrosion fatigue life of steel structure considering mechanical factors

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    Steel structures in corrosive environment are often subjected to coupling effect and damage caused by corrosion and fatigue. This paper proposed a new assessment method to study corrosion fatigue life of steel structure, including the effect of cyclic loading and corrosion damage. Based on mechanical factors, the corrosion depth of structure under cyclic loading at different time intervals was defined by a mathematical model for corrosion damage. A finite element model was established to calculate structure damage. Finally, the cumulative damage could be obtained by Miner guidelines to assess the fatigue life. Comparing traditional methods, the coupling effect of corrosion and fatigue were taken into account by this new method. According to this new method, the results showed that the calculated corrosion rate was faster, and the corrosion fatigue life shorter. Corrosion fatigue could cause more damage to structure than was expected. Furthermore, this method was convenient and practical for assessing/estimating the corrosion fatigue life of normal steel structure

    Effect of Low Temperature Vacuum Slow Cooking on Muscle Quality Characteristics of Half Shell Scallop

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    This study utilized half-shell Chlamys farreri as the primary material to investigate the effects of different sous vide (SV) cooking temperatures (60, 65, 70, 75, 80 ℃) and cooking times (30, 45, 60, 75 min) on the quality attributes of the Chlamys farreri muscle. Sensory quality, drip loss, moisture content, water activity, texture, myofibrillar protein extraction, and microstructure were evaluated as key indicators. The results showed that as the cooking temperature and time increased, the sensory scores of SV Chlamys farreri initially rose and then declined, with the highest sensory score observed at 70 and 75 ℃ after 30 minutes of cooking. The drip loss of SV Chlamys farreri increased between 60 and 75 ℃ without significant differences (P0.05). Scanning electron microscopy and HE staining illustrated that as the cooking temperature increased, myofibrils underwent breakage, boundaries became indistinct, fractured myofibrils were cross-linked, and the disorder level escalated, ultimately leading to the aggregation of broken myofibrils into large masses. In conclusion, the optimal sensory quality of the scallops was achieved at 70 and 75 ℃ with 30 minutes of SV cooking, where drip loss and elasticity were lower than those in the control group (100 ℃, 15 min), while moisture content, water activity, hardness, and myofibrillar protein extraction rate were higher than those in the control group

    The Mechanism of ATP-Dependent Allosteric Protection of Akt Kinase Phosphorylation

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    SummaryKinases use ATP to phosphorylate substrates; recent findings underscore the additional regulatory roles of ATP. Here, we propose a mechanism for allosteric regulation of Akt1 kinase phosphorylation by ATP. Our 4.7-μs molecular dynamics simulations of Akt1 and its mutants in the ATP/ADP bound/unbound states revealed that ATP occupancy of the ATP-binding site stabilizes the closed conformation, allosterically protecting pT308 by restraining phosphatase access and key interconnected residues on the ATP→pT308 allosteric pathway. Following ATP→ADP hydrolysis, pT308 is exposed and readily dephosphorylated. Site-directed mutagenesis validated these predictions and indicated that the mutations do not impair PDK1 and PP2A phosphatase recruitment. We further probed the function of residues around pT308 at the atomic level, and predicted and experimentally confirmed that Akt1H194R/R273H double mutant rescues pathology-related Akt1R273H. Analysis of classical Akt homologs suggests that this mechanism can provide a general model of allosteric kinase regulation by ATP; as such, it offers a potential avenue for allosteric drug discovery

    Research on the design of somatosensory interactive games for autistic children based on art therapy

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    There is no targeted drug treatment for autistic children. Educational intervention and rehabilitation are the main ways to improve the ability development of autistic children. However, there are great differences in the individual symptoms and abilities. It is an urgent need for educators, practitioners and parents of autistic children to find effective ways to improve their cognitive, social and motor abilities. The author cooperates with the therapist to study and design the somatosensory interaction game for autistic children, which is a formal attempt of art therapy on the treatment tool, with the purpose of studying an effective and safe art intervention method. In order to verify the effect, the author recruited 26 children with mild or moderate autism for a six-week empirical evaluation, and the participants were randomly assigned. Among them, 13 participants participated in the art therapy of the proposed somatosensory game group (the experimental group), and 13 participants participated the traditional picture book group (the control group) that improved the emotion, cognition and skills of children, and the design style was more popular with children. The aesthetic design in the picture book could have an intervention effect on the participants, and its artistic effect could serve as an effective reference for the interface design of the game group. The results showed that the two groups had a significant impact on the participants in different aspects. The game group improved not only in terms of concentration and special ability, but also in terms of physical coordination and activity enhancement, it is inferred that the core factors of game therapy are sub-intervention, interaction and feedback, icon design and color matching system; the picture book group has significant improvement in interpersonal relationship guidance and language learning and communication. The results show that it is necessary to take more comprehensive and richer preliminary research on the development of treatment products for autistic children. Because picture book education requires children’s initial concentration, it is found that picture book therapy has high requirements for teachers’ classroom control and relatively strict requirements for picture book content, and play therapy can be a good complement to these problems

    Telomere maintenance-related genes are important for survival prediction and subtype identification in bladder cancer

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    Background: Bladder cancer ranks among the top three in the urology field for both morbidity and mortality. Telomere maintenance-related genes are closely related to the development and progression of bladder cancer, and approximately 60%–80% of mutated telomere maintenance genes can usually be found in patients with bladder cancer.Methods: Telomere maintenance-related gene expression profiles were obtained through limma R packages. Of the 359 differential genes screened, 17 prognostically relevant ones were obtained by univariate independent prognostic analysis, and then analysed by LASSO regression. The best result was selected to output the model formula, and 11 model-related genes were obtained. The TCGA cohort was used as the internal group and the GEO dataset as the external group, to externally validate the model. Then, the HPA database was used to query the immunohistochemistry of the 11 model genes. Integrating model scoring with clinical information, we drew a nomogram. Concomitantly, we conducted an in-depth analysis of the immune profile and drug sensitivity of the bladder cancer. Referring to the matrix heatmap, delta area plot, consistency cumulative distribution function plot, and tracking plot, we further divided the sample into two subtypes and delved into both.Results: Using bioinformatics, we obtained a prognostic model of telomere maintenance-related genes. Through verification with the internal and the external groups, we believe that the model can steadily predict the survival of patients with bladder cancer. Through the HPA database, we found that three genes, namely ABCC9, AHNAK, and DIP2C, had low expression in patients with tumours, and eight other genes—PLOD1, SLC3A2, RUNX2, RAD9A, CHMP4C, DARS2, CLIC3, and POU5F1—were highly expressed in patients with tumours. The model had accurate predictive power for populations with different clinicopathological features. Through the nomogram, we could easily assess the survival rate of patients. Clinicians can formulate targeted diagnosis and treatment plans for patients based on the prediction results of patient survival, immunoassays, and drug susceptibility analysis. Different subtypes help to further subdivide patients for better treatment purposes.Conclusion: According to the results obtained by the nomogram in this study, combined with the results of patient immune-analysis and drug susceptibility analysis, clinicians can formulate diagnosis and personalized treatment plans for patients. Different subtypes can be used to further subdivide the patient for a more precise treatment plan

    Inhibition of GABAA receptors in intestinal stem cells prevents chemoradiotherapy-induced intestinal toxicity.

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    peer reviewedLethal intestinal tissue toxicity is a common side effect and a dose-limiting factor in chemoradiotherapy. Chemoradiotherapy can trigger DNA damage and induce P53-dependent apoptosis in LGR5+ intestinal stem cells (ISCs). Gamma-aminobutyric acid (GABA) and its A receptors (GABAAR) are present in the gastrointestinal tract. However, the functioning of the GABAergic system in ISCs is poorly defined. We found that GABAAR α1 (GABRA1) levels increased in the murine intestine after chemoradiotherapy. GABRA1 depletion in LGR5+ ISCs protected the intestine from chemoradiotherapy-induced P53-dependent apoptosis and prolonged animal survival. The administration of bicuculline, a GABAAR antagonist, prevented chemoradiotherapy-induced ISC loss and intestinal damage without reducing the chemoradiosensitivity of tumors. Mechanistically, it was associated with the reduction of reactive oxygen species-induced DNA damage via the L-type voltage-dependent Ca2+ channels. Notably, flumazenil, a GABAAR antagonist approved by the U.S. Food and Drug Administration, rescued human colonic organoids from chemoradiotherapy-induced toxicity. Therefore, flumazenil may be a promising drug for reducing the gastrointestinal side effects of chemoradiotherapy.Taishan Pandeng Scholar Program of Shandong Provinc
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