45 research outputs found

    In vitro and in vivo antitumor properties of 7-epidocetaxel, a major impurity of docetaxel

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    Purpose: To investigate the antitumor properties and toxicity of 7-epi docetaxel (7-epi DTX) as an active pharmaceutical ingredient, and in formulations.Methods: Docetaxel-loaded albumin nanoparticles (DTX NPs) were prepared by freeze-drying, while 7- epi DTX was detected and isolated by high performance liquid chromatography (HPLC). Their antitumor properties were evaluated in vitro in CT26 cells and in vivo in BALB/c sk-ov-3 xenograft nude mice model. The tissues were histological examined.Results: The in vivo antitumor effects of DTX NPs at different doses of 7-epi DTX were similar. Moreover, the in vitro anti-cancer effect of 7-epi DTX was comparable to that of DTX. However, the in vivo antitumor effectiveness of 7-epi DTX was inferior to that of DTX. In toxicity studies, 7-epi DTX did not elicit any acute toxic effects both as active pharmaceutical ingredients, and as a component of formulations.Conclusion: The results indicate that 7-epi DTX does not elicit acute toxic effects both as an active pharmaceutical ingredient and in bulk formulations. The antitumor property of 7-epi DTX is less than that of DTX.Keywords: 7-Epidocetaxel, Impurity, Antitumor properties, Toxicit

    Lifelong Embedding Learning and Transfer for Growing Knowledge Graphs

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    Existing knowledge graph (KG) embedding models have primarily focused on static KGs. However, real-world KGs do not remain static, but rather evolve and grow in tandem with the development of KG applications. Consequently, new facts and previously unseen entities and relations continually emerge, necessitating an embedding model that can quickly learn and transfer new knowledge through growth. Motivated by this, we delve into an expanding field of KG embedding in this paper, i.e., lifelong KG embedding. We consider knowledge transfer and retention of the learning on growing snapshots of a KG without having to learn embeddings from scratch. The proposed model includes a masked KG autoencoder for embedding learning and update, with an embedding transfer strategy to inject the learned knowledge into the new entity and relation embeddings, and an embedding regularization method to avoid catastrophic forgetting. To investigate the impacts of different aspects of KG growth, we construct four datasets to evaluate the performance of lifelong KG embedding. Experimental results show that the proposed model outperforms the state-of-the-art inductive and lifelong embedding baselines.Comment: Accepted in the 37th AAAI Conference on Artificial Intelligence (AAAI 2023

    Spatiotemporal patterns and driving mechanism of tourism ecological security in Guangxi, China

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    Tourism ecological security (TES) is an important index reflecting the sustainable development of the regional economy. The construction of the China and ASEAN Free Trade Area has increased the total tourist consumption of Guangxi province by 36.48%. Unfortunately, overconsumption of resources, air pollution, disturbance of indigenous life, and other environmental degradation problems emerged due to the significant increase in tourists. Measuring the resilience of the tourism ecosystem is an urgent need to promote the high-quality development of tourism in Guangxi. To explore the dynamic changes in TES and its driving mechanism, the DPSIR (driver–pressure–state–impact–response) model for the tourism ecosystem was developed. The dynamic changes in TES and its driving mechanism from 2010 to 2019 were analyzed using fuzzy matter-element analysis, Markov chains, Geodetector, and other methods. The results show that: (1) the TES value increased steadily by 72.73%; the improvement speed was Northeast > Southwest > Southeast > Northwest; (2) TES was negatively correlated with location, 14 cities developed independently; (3) the TES has a smaller probability to shift the lower level; (4) urbanization, water consumption, green area, tourism revenue, and the number of students in colleges had significant effects on TES. Four policies were proposed to improve TES: (1) developing forest tourism; (2) implementing greening projects in abandoned mining areas; (3) increasing tourism technical personnel; and (4) reducing clearance time for inbound tourists

    Research Progress of Nutrition Support for Patients with Lung Cancer 
During Chemotherapy

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    Primary lung cancer is one of the most common malignancies. Nowadays, both its morbidity and mortality rank first, patients with lung cancer are often goes with some affiliating symptoms such as malnutrition and weight loss. The side effects of cytotoxicity during chemotherapy may lead to further deteriorate of the nutritional status and worsen the anti-tumor therapy’s efficacy and the patients’ quality of life. With the development of palliative treatment and the higher request of patients for quality of life, nutritional support will be an important adjunctive treatment to maintain a good nutritional status and enhance the patients’ immunity during chemotherapy. It will play an active role in improving tolerability of chemotherapy and prognosis for patients with lung cancer. Here is a review about research progress of nutrition support treatment during chemotherapy for the patients with lung cancer

    Research on the transformerless connection mode for DC power distribution system

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    The connection mode of the flexible DC distribution network and the AC network is not only the basis of the system design but also is one of the key technologies in the DC distribution. This paper demonstrates the feasibility of the transformerless system using modular multilevel converters (MMC) in the power distribution system. Here, in allusion to the DC power distribution network without transformer, the influence of AC system fault on DC system and the influence of DC system fault on AC system are analysed in detail separately. By establishing the simulation model with the PSCAD/EMTDC software, the transformerless system proposed is verified feasible at the appropriate voltage and the appropriate earthing way of AC system. The research proposed a solution of saving economic cost and space which is the critical issue in the conventional DC power distribution system with the transformer

    Research on an Asymmetric Fault Control Strategy for an AC/AC System Based on a Modular Multilevel Matrix Converter

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    This paper studies control strategies for an AC/AC system based on a modular multilevel matrix converter (M3C) when an asymmetric fault occurs in the secondary side ac system. Firstly, the operating principle of M3C is briefly introduced and verified by simulation. Then, based on its mathematical model by double αβ0 transformation, the decoupled control strategies for the primary side and secondary side systems are designed. In view of the asymmetric fault condition of the secondary side system, the positive sequence and negative sequence components of voltages and currents are separated and extracted, and then a proportional resonant controller (PR) is used to regulate the positive and negative sequence currents at the same time to realize decoupled current control in the αβ reference frames. The capacitor voltage balancing control, which consists of an inter-subconverter balancing control and an inner-subconverter balancing control, is realized by adjusting four circulating currents. Finally, the proposed control strategy is validated by simulation in the PSCAD/EMTDC software (Manitoba HVDC Research Center, Canada). The result shows that during the period of the BC-phase short-circuit fault occurring in the secondary side system, the whole system can still operate stably and transmit a certain amount of active power, according to their set values. Furthermore, the capacitor voltages are balanced, with a slight increase during the fault period. The simulation results verify the effectiveness of the proposed control strategy

    The scaling of laser peen forming:A two-experiment finite similitude approach

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    Laser peen forming (LPF) utilizes laser-induced shock waves to bend and shape metal plates in what is effectively a non-thermal metal-forming process involving no hard tooling. A difficulty with the process, arising from the rapid localized physics involved, is the determination of process conditions for the establishment of desirable process outcomes. The nanosecond physical behaviors induced by the pulsed laser can make simulation impractical, effectively restricting investigations to experiments as the only practical recourse. This paper focuses on the use of scaled experimentation for LPF with the objective of making experimental outcomes more broadly applicable to a wider range of process conditions. Understanding how processes scale can in principle aid in the establishment of process parameters through timely and cost-effective experiments. Scaled experimentation has recently undergone a paradigm shift with the arrival of the finite similitude scaling theory. The theory provides extra degrees of freedom and facilitates the use of unlimited numbers of scaled experiments and allows for anisotropy in plate thickness. It is demonstrated in the work through experimental tests and simulation at two different scales, that geometric and loading similarities can be broken, yet the behavior of LPF can be quantified to good accuracy.</p

    Cervical Cancer Correlates with the Differential Expression of Nicotinic Acetylcholine Receptors and Reveals Therapeutic Targets

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    Nicotinic acetylcholine receptors (nAChRs) are associated with various cancers, but the relation between nAChRs and cervical cancer remains unclear. Therefore, this study investigated the differential expression of nAChR subunits in human cervical cancer cell lines (SiHa, HeLa, and CaSki) and in normal ectocervical cell lines (Ect1/E6E7) at mRNA and protein levels. Two specific nAChR subtype blockers, &#945;O-conotoxin GeXIVA and &#945;-conotoxin TxID, were then selected to treat different human cervical cancer cell lines with specific nAChR subtype overexpression. The results showed that &#945;3, &#945;9, &#945;10, and &#946;4 nAChR subunits were overexpressed in SiHa cells compared with that in normal cells. &#945;9 and &#945;10 nAChR subunits were overexpressed in CaSki cells. &#945;*-conotoxins that targeted either &#945;9&#945;10 or &#945;3&#946;4 nAChR were able to significantly inhibit cervical cancer cell proliferation. These findings may provide a basis for new targets for cervical cancer targeted therapy

    Distributed Feedforward Optimization for Control of Multi-Energy Network with Temporal Variations

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    Multi-Energy Network (MEN) is a promising approach to improve the overall efficiency of energy utilization. Yet, balancing its electrical and thermal power in real-time is challenging due to variable demands. In this paper, we formulate a distributed Time Varying Optimization Problem (TVOP) and solve it in continuous-time to track the unknown time-varying optimal trajectories. First, we apply the principles of output regulation theory to reverse engineer the feedforward laws in the presence of projection. These laws are responsible for proactively canceling the effects of temporal demand variations. Then, a projection-based distributed optimization algorithm, alongside a distributed auxiliary protocol based on weighted-sum consensus, result in a novel scheme we term distributed feedforward optimization. One of the key features of our scheme is its data-driven nature, where temporal variations are captured from Ultra-Short-Term Forecasting (USTF) profiles using an exosystem. Under mild assumptions, the proposed scheme provides a guarantee for asymptotic convergence. Simulation results demonstrate the effectiveness of our scheme under an non-ideal case.</p

    Modified Modeling and System Stabilization of Shunt Active Power Filter Compensating Loads with ÎĽF Capacitance

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    The interactions between shunt active power filter (APF) and capacitance load tend to result in stability problems and resonance. The conventional model of a shunt APF is not precise enough to reflect this phenomenon. To address it, this paper proposes a modified shunt APF system model to accurately reflect various stability problems. This paper also studies the mechanism of positive feedback resonance brought by capacitance load and proposes a modified hybrid controller to improve the stable margin of the system, making the shunt APF work stably under different working conditions where there are &mu;F capacitors on the demand side. The correctness and validity of the proposed strategy are verified by simulation analysis and prototype experiments
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