24 research outputs found

    ToxicChat: Unveiling Hidden Challenges of Toxicity Detection in Real-World User-AI Conversation

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    Despite remarkable advances that large language models have achieved in chatbots, maintaining a non-toxic user-AI interactive environment has become increasingly critical nowadays. However, previous efforts in toxicity detection have been mostly based on benchmarks derived from social media content, leaving the unique challenges inherent to real-world user-AI interactions insufficiently explored. In this work, we introduce ToxicChat, a novel benchmark based on real user queries from an open-source chatbot. This benchmark contains the rich, nuanced phenomena that can be tricky for current toxicity detection models to identify, revealing a significant domain difference compared to social media content. Our systematic evaluation of models trained on existing toxicity datasets has shown their shortcomings when applied to this unique domain of ToxicChat. Our work illuminates the potentially overlooked challenges of toxicity detection in real-world user-AI conversations. In the future, ToxicChat can be a valuable resource to drive further advancements toward building a safe and healthy environment for user-AI interactions

    Multivariable Super Twisting Based Robust Trajectory Tracking Control for Small Unmanned Helicopter

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    This paper presents a highly robust trajectory tracking controller for small unmanned helicopter with model uncertainties and external disturbances. First, a simplified dynamic model is developed, where the model uncertainties and external disturbances are treated as compounded disturbances. Then the system is divided into three interconnected subsystems: altitude subsystem, yaw subsystem, and horizontal subsystem. Second, a disturbance observer based controller (DOBC) is designed based upon backstepping and multivariable super twisting control algorithm to obtain robust trajectory tracking property. A sliding mode observer works as an estimator of the compounded disturbances. In order to lessen calculative burden, a first-order exact differentiator is employed to estimate the time derivative of the virtual control. Moreover, proof of the stability of the closed-loop system based on Lyapunov method is given. Finally, simulation results are presented to illustrate the effectiveness and robustness of the proposed flight control scheme

    Optimization of Extraction Conditions of Carotenoids from Dunaliella parva by Response Surface Methodology

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    Extraction conditions can exert a remarkable influence on extraction efficiency. The aim of this study was to improve the extraction efficiency of carotenoids from Dunaliella parva (D. parva). Dimethyl sulfoxide (DMSO) and 95% ethanol were used as the extraction solvents. The extraction time, extraction temperature and the proportions of mixed solvent were taken as influencing factors, and the experimental scheme was determined by Central Composite Design (CCD) of Design Expert 10.0.4.0 to optimize the extraction process of carotenoids from D. parva. The absorbance values of the extract at 665 nm, 649 nm and 480 nm were determined by a microplate spectrophotometer, and the extraction efficiency of carotenoids was calculated. Analyses of the model fitting degree, variance and interaction term 3D surface were performed by response surface analysis. The optimal extraction conditions were as follows: extraction time of 20 min, extraction temperature of 40 °C, and a mixed solvent ratio (DMSO: 95% ethanol) of 3.64:1. Under the optimal conditions, the actual extraction efficiency of carotenoids was 0.0464%, which was increased by 18.19% (the initial extraction efficiency of 0.03926%) with a lower extraction temperature (i.e., lower energy consumption) compared to the standard protocol

    Optimization of Molasses and Soybean Meal Content to Enhance Tetramethylpyrazine Yield by <i>Bacillus</i> sp. TTMP20

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    Microbial fermentation for the production of tetramethylpyrazine (TTMP) is considered to be the most promising method, and the development of a cheap fermentation substrate is of great importance for large-scale TTMP production. In this study, inexpensive by-products from the food industry, i.e., molasses and soybean meal (instead of glucose and tryptone), were used as substrates for TTMP fermentation. The pretreatment of soybean meal was explored in order to achieve a better fermentation effect. The contents of each component in the fermentation medium were optimized by central composite design (CCD). The optimum contents were as follows: 72.5 g/L of molasses, 37.4 g/L of diammonium hydrogen phosphate (DAP), 53.4 g/L of soybean meal, and 5 g/L of yeast powder. The software predicted a maximum TTMP yield of 1469.03 mg/L, and the actual TTMP yield was 1328.95 mg/L for the validation experiment in the optimum medium. Under the optimum conditions (72.5 g/L of molasses, 37.4 g/L of DAP, 53.4 g/L of soybean meal, and 5 g/L of yeast powder), the actual maximum TTMP yield (1328.95 mg/L) in this study was much higher than the TTMP yield (895.13 mg/L) under the conditions (150 g/L of molasses, 30 g/L of DAP, 30 g/L of tryptone, and 10 g/L of yeast powder) of our previous study published in Molecules. In this study, the TTMP yield improved by 48.46%, with decreased molasses (more than half), decreased yeast powder (half) and by-product soybean meal instead of tryptone compared to our previous study. In summary, the cheaper fermentation medium had a higher TTMP yield in this study, which improves the application potential of Bacillus sp. TTMP20

    Signaling pathways of adipose stem cell-derived exosomes promoting muscle regeneration

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    Abstract. Severe muscle injury is still a challenging clinical problem. Exosomes derived from adipose stem cells (ASC-exos) may be a potential therapeutic tool, but their mechanism is not completely clear. This review aims to elaborate the possible mechanism of ASC-exos in muscle regeneration from the perspective of signal pathways and provide guidance for further study. Literature cited in this review was acquired through PubMed using keywords or medical subject headings, including adipose stem cells, exosomes, muscle regeneration, myogenic differentiation, myogenesis, wingless/integrated (Wnt), mitogen-activated protein kinases, phosphatidylinositol-4,5-bisphosphate 3-kinase/protein kinase B (PI3K/Akt), Janus kinase/signal transducers and activators of transcription, and their combinations. We obtained the related signal pathways from proteomics analysis of ASC-exos in the literature, and identified that ASC-exos make different contributions to multiple stages of skeletal muscle regeneration by those signal pathways

    Prospective application of poloxamer 188 in plastic surgery: A comprehensive review

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    An increasing number of researchers have demonstrated that poloxamer 188 (P188) can be used as a pharmaceutical excipient for clinical applications. Its membrane-sealing effects and inherent biological activities make it an extremely promising agent for plastic surgery. In this review, we summarize the positive roles of P188 in autologous fat grafting, wound healing, and cartilage transplantation. These roles include improving the survival rate of fat grafts and chondrocytes, stimulating the metabolic activity of adipocytes, promoting wound healing, and contributing to cartilage formation. Although further research is still needed, it is clear that P188 has great potential and application value in the field of plastic surgery

    Factors influencing myogenic differentiation of adipose-derived stem cells and their application in muscle regeneration

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    Skeletal muscle regeneration mainly depends on muscle satellite cells; however, these cells are not sufficient for supporting repair and regeneration in volumetric muscle loss (VML), Duchenne muscular dystrophy, and other muscle injuries or muscle diseases. As such, much work has been conducted in recent years to search for myogenic stem cells. Adipose-derived stem cells (ADSCs) have a wide range of sources, rapid growth, and multi-directional differentiation potential, and have become vital candidates for muscle regeneration. Multiple factors influence the myogenic differentiation capacity of ADSCs. This paper reviews the regulatory aspects and possible factors that have been identified in recent years to affect myogenic differentiation of ADSCs. Based on these factors, gene editing, and perfusion concepts, a method was proposed to achieve maximal differentiation efficiency of ADSCs. This study focused on the application of ADSCs in muscle regeneration and disease. Based on the importance of myogenic differentiation of ADSCs for the repair and regeneration of muscle damage, this study provides a basis for future research surrounding the efficient induction of myogenic differentiation of ADSCs in vitro

    Impact of the COVID-19 pandemic on the conduct of non-COVID-19 clinical trials: protocol for a scoping review

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    Introduction The COVID-19 pandemic posed a detrimental impact on the conduct of non-COVID-19 related clinical trials, raising concerns about the completeness of these studies and waste of resources. While several measures and strategies have been suggested to address these issues, a thorough and timely summarisation is still lacking. Therefore, our aim is to conduct a scoping review to summarise the negative effects of COVID-19 on non-COVID-19 clinical trials, outline the effective measures for mitigating these impacts, and provide insights for future pandemics.Methods and analysis This scoping review will be conducted in line with the Joanna Briggs Institute’s scoping review methodological framework, and the results will be reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews. Relevant articles will be searched in PubMed, Embase and the Cochrane Library from 1 December 2019 to 1 July 2023. We will also screen the reference lists of the included studies manually to identify more potentially relevant articles. Articles focusing on the adverse impacts of COVID-19 on non-COVID-19 clinical trials and effective measures for mitigating them will be included. Two investigators will perform study selection and data extraction independently. A narrative summary as well as a descriptive analysis of the basic characteristics and key results of the included studies will be performed.Ethics and dissemination Ethical approval is not required, as this scoping review will be completed based only on published literature. The findings of this scoping review will be disseminated through a peer-reviewed publication and/or conference presentations
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