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Influence of fatty alcohol mixing ratios on the physicochemical properties of stearyl-cetyl alcohol-polysorbate 60-water ternary system: Insights from experiments and computer simulations

arXiv

引用

arXiv 2021年

作者： Hoang, Vu Dang Cong, Cao Phuong Tran, Hung Huu Nguyen, Hue Minh Thi Nguyen, Toan T. Department of Analytical Chemistry and Toxicology Hanoi University of Pharmacy 13-15 Le Thanh Tong street Hanoi Viet Nam Key Laboratory for Multiscale Simulation of Complex Systems VNU University of Science Vietnam National University 334 Nguyen Trai street Thanh Xuan Hanoi120401 Viet Nam Faculty of Chemistry and Center for Computational Science Hanoi National University of Education 136 Xuan Thuy street Cau Giay Hanoi Viet Nam

The structure and stability of ternary systems prepared with polysorbate 60 and various combinations of cetyl (C16) and stearyl (C18) alcohols were examined as they aged over 3 months at 25◦C. Rheological results showed that the consistency of these systems increased initially during roughly the first week of aging, which was succeeded by little changes in consistency (systems containing from 30% to 70% C18, with the 50% C18 system showing the highest consistencies) or significant breakdown of structure (remaining systems). The formation and/or disintegration of all ternary systems were also detected by microscopy and differential scanning calorimetry experiments. This study emphasizes the fact that the structure and consistency of ternary systems are dominantly controlled by the swelling capacity of the lamellar gel phase. Molecular dynamics simulations were performed to provide details on the molecular mechanism of stability. Computational results support the hypothesis experimentally proposed for the stability of the mixed system being due to an increase flexibility of the alcohol with a longer hydrocarbon chain. Computational results are in excellent agreement with experimental conclusions. Additionally, they show that in the mixed system, alcohols with shorter hydrocarbon chain become more rigid. These molecular details could not be available in experimental measurements. Copyright © 2021, The Authors. All rights reserved.

关键词： Molecular dynamics

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Investigating molecular mechanism for the stability of ternary systems containing cetrimide, fatty alcohol and water by using computer simulation

arXiv

引用

arXiv 2019年

作者： Hoang, Vu Dang Tran, Hung Huu Phuong, Cao Cong Thi Nguyen, Hue Minh Nguyen, Toan T. Department of Analytical Chemistry and Toxicology Hanoi University of Pharmacy 13-15 Le Thanh Tong Hoan Kiem Hanoi Viet Nam Faculty of Chemistry Center for Computational Science Hanoi National University of Education 136 Xuan Thuy Street Cau Giay Hanoi Viet Nam Faculty of Physics VNU Key Laboratory on Multiscale Simulation of Complex Systems VNU University of Science Vietnam National University 334 Nguyen Trai Street Thanh Xuan Hanoi Viet Nam

Computer simulations using atomistic model are carried out to investigate the stability of ternary systems of pure or mixed fatty alcohols, cetrimide, and water. These semi−solid oil-in-water systems are used as the main component of pharmaceutical creams. Experiments show that the mixed alcohol systems are more stable than pure ones. The current experimental hypothesis is that this is the result of the length mismatch of the alkyl chains. This leads to higher configurational entropy of the chain tip of the longer alcohol molecules. Our simulation results support this hypothesis. The results also show that the shorter alcohol molecules become stiffer with higher values of the deuterium order parameters and smaller area per molecule. The magnitude in fluctuations in the area per molecule also increases in mixed systems, indicating a higher configurational entropy. Analysis of the molecular structure of simulated systems also shows good agreements with experimental data. Copyright © 2019, The Authors. All rights reserved.

关键词： Molecules

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Mass- and energy-preserving exponential Runge-Kutta methods for the nonlinear Schrödinger equation

arXiv

引用

arXiv 2020年

作者： Cui, Jin Xu, Zhuangzhi Wang, Yushun Jiang, Chaolong Department of Basic Sciences Nanjing Vocational College of Information Technology Nanjing210023 China Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems School of Mathematical Sciences Nanjing Normal University Nanjing210023 China Department of Mathematics College of Liberal Arts and Science National University of Defense Technology Changsha410073 China School of Statistics and Mathematics Yunnan University of Finance and Economics Kunming650221 China

In this paper, a family of arbitrarily high-order structure-preserving exponential Runge-Kutta methods is developed for the nonlinear Schrödinger equation by combing the scalar auxiliary variable approach and the exponential Runge-Kutta method. By introducing an auxiliary variable, we first transform the original model into an equivalent system which admits both mass and modified energy. Then applying the Lawson method and the symplectic Runge-Kutta method in time, we derive a class of mass- and energy-conserving time-discrete schemes. Numerical experiments are addressed to demonstrate the accuracy and effectiveness of the newly proposed schemes. Copyright © 2020, The Authors. All rights reserved.

关键词： Runge Kutta methods

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Arbitrary high-order linear structure-preserving schemes for the regularized long-wave equation

arXiv

引用

arXiv 2021年

作者： Jiang, Chaolong Qian, Xu Song, Songhe Cui, Jin Department of Mathematics College of Liberal Arts and Science National University of Defense Technology Changsha410073 China School of Statistics and Mathematics Yunnan University of Finance and Economics Kunming650221 China Department of Basic Sciences Nanjing Vocational College of Information Technology Nanjing210023 China Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems School of Mathematical Sciences Nanjing Normal University Nanjing210023 China

In this paper, a class of arbitrarily high-order linear momentum-preserving and energy-preserving schemes are proposed, respectively, for solving the regularized long-wave equation. For the momentum-preserving scheme, the key idea is based on the extrapolation/prediction-correction technique and the symplectic Runge-Kutta method in time, together with the standard Fourier pseudo-spectral method in space. We show that the scheme is linear, high-order, unconditionally stable and preserves the discrete momentum of the system. For the energy-preserving scheme, it is mainly based on the energy quadratization approach and the analogous linearized strategy used in the construction of the linear momentum-preserving scheme. The proposed scheme is linear, high-order and can preserve a discrete quadratic energy exactly. Numerical results are addressed to demonstrate the accuracy and efficiency of the proposed scheme. Copyright © 2021, The Authors. All rights reserved.

关键词： Runge Kutta methods

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Construction of dimeric hTSPO protein model using homology modeling and molecular dynamics

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Journal of Physics: Conference Series 2021年第1期1932卷

作者： Hien T T Lai Toan T Nguyen Key Laboratory for Multiscale Simulation of Complex Systems VNU University of Science Vietnam National University - Hanoi 334 Nguyen Trai street Thanh Xuan district Hanoi Vietnam

A model for the dimeric form of the human TSPO (hTSPO) protein is constructed homologically using the RsTSPO dimer template. Then, Molecular dynamics simulation of 1μs is carried out on the model to investigate its stability as well as to study its various physicochemical properties. Our model shows good stability, with various important conserved residues involving in monomer–monomer interactions, in good agreements with available experimental data. Several functioning motifs are well demonstrated. This model hence can serve as a good basis for further study of this system as well as for discoveries of candidate radioligands targeting TSPO protein as a biotracer for medical imaging of brain inflamation.

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Computational study of the effect of protonation states of PSA protein zinc fingers on its DNA binding

引用

Journal of Physics: Conference Series 2019年第1期1274卷

作者： Nguyen Viet Duc Ly Hai Nguyen Hien T. T. Lai Toan T. Nguyen VNU Key Laboratory for Multiscale Simulation of Complex Systems VNU University of Science Vietnam National University 334 Nguyen Trai street Thanh Xuan Hanoi 11416 VIETNAM

In this study, we investigate the binding of the Zinc finger (ZF) structure on a short DNA molecule. The zinc finger of a protein where a Zn2+ ion binds to 4 cysteine or histidine amino acids in a tetrahedral structure is a very common motif of nucleic acid binding proteins. This structure is ubiquitous and the corresponding interaction model is present in 3% of the genes of human genome. ZF has been shown to be extremely useful in various therapeutic and research capacities, as well as in biotechnology. A recent computational study has shown that isolated zinc finger structure is stable if the cysteine amino acids are in deprotonated state. Here, we investigate how this deprotonated state influences protein structure, dynamics, and function in binding of ZF to short DNA molecules using molecular dynamics simulations in sub-microsecond range. Our results show that the Zn2+ ion and the deprotonated state of cysteine is essential for mechanical stabilization of the functional, folded conformation. Not only this state stabilizes the ZF structure, it also stabilizes the DNA-binding structure. Our result has potential impact on better design of zinc fingers for various biotechnological applications.

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Multi-task Paired Masking with Alignment modeling for Medical Vision-Language Pre-training

arXiv

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arXiv 2023年

作者： Zhang, Ke Yang, Yan Yu, Jun Jiang, Hanliang Fan, Jianping Huang, Qingming Han, Weidong The Key Laboratory of Complex Systems Modeling and Simulation School of Computer Science and Technology Hangzhou Dianzi University Hangzhou310018 China Regional Medical Center for National Institute of Respiratory Diseases Sir Run Run Shaw Hospital College of Medicine Zhejiang University Hangzhou310016 China AI Lab at Lenovo Research 100094 China The School of Computer Science and Technology University of Chinese Academy of Sciences Beijing101408 China The Department of Medical Oncology at Sir Run Run Shaw Hospital College of Medicine Zhejiang University Hangzhou China The College of Mathematical Medicine Zhejiang Normal University Jinhua China

In recent years, the growing demand for medical imaging diagnosis has placed a significant burden on radiologists. As a solution, Medical Vision-Language Pre-training (Med-VLP) methods have been proposed to learn universal representations from medical images and reports, benefiting downstream tasks without requiring fine-grained annotations. However, existing methods have overlooked the importance of cross-modal alignment in joint image-text reconstruction, resulting in insufficient cross-modal interaction. To address this limitation, we propose a unified Med-VLP framework based on Multi-task Paired Masking with Alignment (MPMA) to integrate the cross-modal alignment task into the joint image-text reconstruction framework to achieve more comprehensive cross-modal interaction, while a Global and Local Alignment (GLA) module is designed to assist self-supervised paradigm in obtaining semantic representations with rich domain knowledge. Furthermore, we introduce a Memory-Augmented Cross-Modal Fusion (MA-CMF) module to fully integrate visual information to assist report reconstruction and fuse the multi-modal representations adequately. Experimental results demonstrate that the proposed unified approach outperforms previous methods in all downstream tasks, including uni-modal, cross-modal, and multimodal tasks. Copyright © 2023, The Authors. All rights reserved.

关键词： Alignment

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Automatic Term Recognition Method for Military Domain

引用

Journal of Physics: Conference Series 2021年第1期2078卷

作者： Ani Song Xiaoxia Jia Wei Jiang North China Institute of Computing Technology Beijing 100083 China National key Laboratory for Complex Systems Simulation. Department of Systems General Design. Institute of Systems Engineering. AMS. Beijing 100083 China

With the development of military intelligence, higher requirements are put forward for automatic term recognition in military field. In view of the characteristics of flexible and diverse naming of military requirement documents without annotated corpus, the method of this paper uses the existing military domain core database, and matches the data set and core database by Aho-Corasic algorithm and word segmentation technology, so that the terms to be recognized in the data set can be divided into three types. The possible rules of word formation of military terms are summarized and phrases that conform to the rules of word formation are found in the documents as the term candidate set. The core library and TF-IDF method are used to calculate the value of the candidate terms, and the candidate terms whose value is greater than the threshold are selected iteratively as the real terms. The experimental results show that the F1 value of this method reaches 0.719, which is better than the traditional C-value method. Therefore, the method proposed in this paper can achieve better automatic term recognition effect for military requirement documents without annotation.

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Scaled Background Swap: Video Augmentation for Action Quality Assessment with Background Debiasing

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ACM Transactions on Multimedia Computing, Communications, and Applications 1000年

作者： Xin Zhang Hongzhi Feng M. Shamim Hossain Yinzhuo Chen Hongbo Wang Yuyu Yin Hangzhou Dianzi University China Key Laboratory of Complex Systems Modeling and Simulation Ministry of Education China Zhoushan Tongbo Marine Electronic Information Research Institute Hangzhou Dianzi University China and Yunnan Key Laboratory of Service Computing Yunnan University of Finance and Economics China Hangzhou Dianzi University China Department of Software Engineering College of Computer and Information Sciences King Saud University Saudi Arabia Hangzhou Dianzi University China Key Laboratory of Complex Systems Modeling and Simulation Ministry of Education China and Zhoushan Tongbo Marine Electronic Information Research Institute Hangzhou Dianzi University China

Action Quality Assessment (AQA) has become crucial in video analysis, finding wide applications in various domains, such as healthcare and sports. A significant challenge faced by AQA is the background bias due to the dominance of the background in videos. Especially, the background bias tends to overshadow subtle foreground differences, which is crucial for precise action evaluation. To address the background bias issue, we propose a novel data augmentation method named Scaled Background Swap. Firstly, the background regions between different video samples are swapped to guide models focus toward the dynamic foreground regions and mitigate its sensitivity to the background during training. Secondly, the video’s foreground region is up-scaled to further enhance models’ attention to the critical foreground action information for AQA tasks. In particular, the proposed Scaled Background Swap method can effectively improve models’ accuracy and generalization by prioritizing foreground motion and swapping backgrounds. It can be flexibly applied with various video analysis models. Extensive experiments on AQA benchmarks demonstrate that Scaled Background Swap method achieves better performance than baselines. Specifically, the Spearman’s rank correlation on datasets AQA-7 and MTL-AQA reaches 0.8870 and 0.9526, respectively. The code is available at: https://***/Emy-cv/Scaled-Background Swap.

关键词： Background Swap Foreground Up-scale Data Augmentation Background Bias Action Quality Assessment

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Charged AdS black hole and the quantum tunneling from black hole to white hole

arXiv

引用

arXiv 2022年

作者： Phat, T.H. Anh, N.T. Nguyen, Toan T. Quyet, H.V. Vietnam Atomic Energy Commission 59 Ly Thuong Kiet Hanoi Viet Nam Faculty of Energy Technology Electric Power University 235 Hoang Quoc Viet Hanoi Viet Nam Key Laboratory for Multiscale Simulation of Complex Systems Department of Theoretical Physics University of Science Vietnam National University − Hanoi 334 Nguyen Trai street Thanh Xuan Hanoi100000 Viet Nam Department of Physics Hanoi Pedagogical University 2 Vinh Phuc Phuc Yen15000 Viet Nam

In this paper, we show that depending on the sign of the electric charge Q, the charged AdS black hole (BH) possesses two alternative facets when the cosmological constant is identified to the thermodynamic pressure P. It is discovered that: 1) the equation of state of BH corresponds to Q > 0 and when Q changes from Q > 0 to Q WH (T) which releases in this process equals with minus sign the latent heat of BH, too;3) Finally, the probability of the quantum tunneling from the BH to the WH is obtained. We suggest the perspective of application of the results above to the AdS/CFT duality. Copyright © 2022, The Authors. All rights reserved.

关键词： Gravitation

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