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Optimization of taste-masking on ibuprofen microspheres with selected structure features 被引量:5
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作者 Wei Qin yuanzhi he +8 位作者 Zhen Guo Liu Zhang Li Wu Xianzhen Yin Shailendra Shakya Abi Maharjan Yan Tang Weifeng Zhu Jiwen Zhang 《Asian Journal of Pharmaceutical Sciences》 SCIE CAS 2019年第2期174-182,共9页
The microsphere was a primary particulate system for taste-masking with unique structural features defined by production process. In this article, ibuprofen lipid microspheres of octadecanol and glycerin monostearate ... The microsphere was a primary particulate system for taste-masking with unique structural features defined by production process. In this article, ibuprofen lipid microspheres of octadecanol and glycerin monostearate were prepared to mask the undesirable taste of ibuprofen via three kinds of spray congealing processes, namely, air-cooling, water-cooling and citric acid solution-cooling. The stereoscopic and internal structures of ibuprofen microspheres were quantitatively analyzed by synchrotron radiation X-ray micro-computed tomography(SR-μCT) to establish the relationship between the preparation process and microsphere architectures. It was found that the microstructure and morphology of the microspheres were significantly influenced by preparation processes as the primary factors to determine the release profiles and taste-masking effects. The sphericity of ibuprofen microspheres congealed in citric acid solution was higher than that of other two and its morphology was more regular than that being congealed in air or distilled water, and the contact angles between congealing media and melted ibuprofen in octadecanol and glycerin monostearate well demonstrated the structure differences among microspheres of three processes which controlled the release characteristics of the microspheres. The structure parameters like porosity, sphericity, and radius ratio from quantitative analysis were correlated well with drug release behaviors. The results demonstrated that the exterior morphology and internal structure of microspheres had considerable influences on the drug release behaviors as well as taste-masking effects. 展开更多
关键词 IBUPROFEN MICROSPHERE SPRAY congealing Internal structure SYNCHROTRON radiation X-ray micro-computed tomography
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Multi-Objective Deep Reinforcement Learning Based Time-Frequency Resource Allocation for Multi-Beam Satellite Communications 被引量:2
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作者 yuanzhi he Biao Sheng +2 位作者 Hao Yin Di Yan Yingchao Zhang 《China Communications》 SCIE CSCD 2022年第1期77-91,共15页
Resource allocation is an important problem influencing the service quality of multi-beam satellite communications.In multi-beam satellite communications, the available frequency bandwidth is limited, users requiremen... Resource allocation is an important problem influencing the service quality of multi-beam satellite communications.In multi-beam satellite communications, the available frequency bandwidth is limited, users requirements vary rapidly, high service quality and joint allocation of multi-dimensional resources such as time and frequency are required. It is a difficult problem needs to be researched urgently for multi-beam satellite communications, how to obtain a higher comprehensive utilization rate of multidimensional resources, maximize the number of users and system throughput, and meet the demand of rapid allocation adapting dynamic changed the number of users under the condition of limited resources, with using an efficient and fast resource allocation algorithm.In order to solve the multi-dimensional resource allocation problem of multi-beam satellite communications, this paper establishes a multi-objective optimization model based on the maximum the number of users and system throughput joint optimization goal, and proposes a multi-objective deep reinforcement learning based time-frequency two-dimensional resource allocation(MODRL-TF) algorithm to adapt dynamic changed the number of users and the timeliness requirements. Simulation results show that the proposed algorithm could provide higher comprehensive utilization rate of multi-dimensional resources,and could achieve multi-objective joint optimization,and could obtain better timeliness than traditional heuristic algorithms, such as genetic algorithm(GA)and ant colony optimization algorithm(ACO). 展开更多
关键词 multi-beam satellite communications time-frequency resource allocation multi-objective optimization deep reinforcement learning
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Co-Frequency Interference Analysis and Avoidance Between NGSO Constellations: Challenges, Techniques, and Trends 被引量:2
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作者 yuanzhi he Yuan Li Hao Yin 《China Communications》 SCIE CSCD 2023年第7期1-14,共14页
In recent years,as giant satellite constellations grow rapidly worldwide,the co-existence between constellations has been widely concerned.In this paper,we overview the co-frequency interference(CFI)among the giant no... In recent years,as giant satellite constellations grow rapidly worldwide,the co-existence between constellations has been widely concerned.In this paper,we overview the co-frequency interference(CFI)among the giant non-geostationary orbit(NGSO)constellations.Specifically,we first summarize the CFI scenario and evaluation index among different NGSO constellations.Based on statistics about NGSO constellation plans,we analyse the challenges in mitigation and analysis of CFI.Next,the CFI calculation methods and research progress are systematically sorted out from the aspects of interference risk analysis framework,numerical calculation and link construction.Then,the feasibility of interference mitigation technologies based on space,frequency domain isolation,power control,and interference alignment mitigation in the NGSO mega-constellation CFI scenario are further sorted out.Finally,we present promising directions for future research in CFI analysis and CFI avoidance. 展开更多
关键词 co-frequency existence analysis method overview interference avoidance
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Drug nanoclusters formed in confined nano-cages of CD-MOF: dramatic enhancement of solubility and bioavailability of azilsartan 被引量:13
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作者 yuanzhi he Wei Zhang +11 位作者 Tao Guo Guoqing Zhang Wei Qin Liu Zhang Caifen Wang Weifeng Zhu Ming Yang Xiaoxiao Hu Vikramjeet Singh Li Wu Ruxandra Gref Jiwen Zhang 《Acta Pharmaceutica Sinica B》 SCIE CSCD 2019年第1期97-106,共10页
Tremendous efforts have been devoted to the enhancement of drug solubility using nanotechnologies, but few of them are capable to produce drug particles with sizes less than a few nanometers. This challenge has been a... Tremendous efforts have been devoted to the enhancement of drug solubility using nanotechnologies, but few of them are capable to produce drug particles with sizes less than a few nanometers. This challenge has been addressed here by using biocompatible versatile γ-cyclodextrin(γ-CD) metal-organic framework(CD-MOF) large molecular cages in which azilsartan(AZL) was successfully confined producing clusters in the nanometer range. This strategy allowed to improve the bioavailability of AZL in Sprague–Dawley rats by 9.7-fold after loading into CD-MOF. The apparent solubility of AZL/CD-MOF was enhanced by 340-fold when compared to the pure drug. Based on molecular modeling, a dual molecular mechanism of nanoclusterization and complexation of AZL inside the CD-MOF cages was proposed, which was confirmed by small angle X-ray scattering(SAXS) and synchrotron radiation-Fourier transform infrared spectroscopy(SR-FTIR) techniques. In a typical cage-like unit of CD-MOF, three molecules of AZL were included by the γ-CD pairs, whilst other three AZL molecules formed a nanocluster inside the 1.7 nm sized cavity surrounded by six γ-CDs. This research demonstrates a dual molecular mechanism of complexation and nanoclusterization in CD-MOF leading to significant improvement in the bioavailability of insoluble drugs. 展开更多
关键词 Γ-CYCLODEXTRIN METAL-ORGANIC framework Nanoclusterization Azilsartan Mechanism SOLUBILITY Bioavailability Molecular modeling
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粘质沙雷氏菌中果糖-1,6-/景天庚酮糖-1,7-二磷酸两个双功能酶的研究
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作者 金文松 杨天行 +5 位作者 何远志 高慧芳 刘文君 林辉 胡开辉 张燎原 《生物技术》 CAS 2018年第5期441-449,共9页
[目的]明确粘质沙雷氏菌中两个FBPases是否同时具有催化果糖-1,6-二磷酸(F-1,6-BP)与景天庚酮糖-1,7-二磷酸(S-1,7-BP)的功能。[方法]PCR构建p ET28a-Sm-FBPase和p ET28a-Sm-Glp X,IPTG诱导表达于大肠杆菌并应用镍柱纯化靶蛋白。应用体... [目的]明确粘质沙雷氏菌中两个FBPases是否同时具有催化果糖-1,6-二磷酸(F-1,6-BP)与景天庚酮糖-1,7-二磷酸(S-1,7-BP)的功能。[方法]PCR构建p ET28a-Sm-FBPase和p ET28a-Sm-Glp X,IPTG诱导表达于大肠杆菌并应用镍柱纯化靶蛋白。应用体外酶学分析Sm-FBPase与Sm-Glp X酶学特性。[结果]SDS-PAGE结果表明Sm-FBPase、Sm-Glp X的分子量是45 k Da、38 k Da。体外酶学分析表明两个酶均可催化F-1,6-BP和S-1,7-BP。Sm-Glp X是Mn2+或Mg2+依赖型酶,而Sm-FBPase的激活需要Mn2+。根据被测试的底物,Sm-FBPase最适p H 7. 0~7. 5、最适温度40℃; Sm-Glp X最适p H 8. 0、最适温度40~45℃。当F-1,6-BP作底物时,Sm-FBPase与Sm-Glp X的Kcat/Km分别为6. 88、7. 55 S-1mmol-1L。然而,当S-1,7-BP作底物时,Sm-FBPase与Sm-Glp X的Kcat/Km分别是3. 17、8. 54 S-1mmol-1L。[结论]Sm-FBPase和Sm-Glp X均可催化F-1,6-BP与S-1,7-BP,Sm-Glp X催化S-1,7-BP的效率是Sm-FBPase的2. 69倍。 展开更多
关键词 粘质沙雷氏菌 景天庚酮糖-1 7-二磷酸酶 果糖-1 6-二磷酸酶 异源表达 酶学特性
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Distributed Satellite Cluster Laser Networking Algorithm with Double-Layer Markov DRL Architecture 被引量:1
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作者 yuanzhi he Biao Sheng +2 位作者 Hao Yin Yun Liu Yingchao Zhang 《Space(Science & Technology)》 EI 2023年第1期80-97,共18页
Considering the demand of distributed satellite clusters for high-speed information communication in the future,this paper establishes a laser network model based on optical multibeam antenna.At present,there are stil... Considering the demand of distributed satellite clusters for high-speed information communication in the future,this paper establishes a laser network model based on optical multibeam antenna.At present,there are still some networking and reconstruction problems,such as network connectivity,duration,and stability.To address them,the paper develops a multiobjective optimization model for the laser networking of distributed satellite clusters,which aims to maximize network connectivity and network duration and minimize the perturbation of the network connection matrix.The model is constructed under the constraints of multibeam antenna capability,the visibility of satellites in clusters,and network connectivity.From the perspectives of the optimization effect and timeliness of the optimization algorithm,a deep reinforcement learning algorithm is proposed,which is based on a double-layer Markov decision model,to meet the needs of on-orbit intelligent networking and dynamic reconstruction of distributed satellite clusters.Simulation results show that the algorithm features flexible architecture,excellent networking performance,and strong real-time performance.When the optimization results are similar,the proposed algorithm outperforms the nonsorted genetic algorithm II algorithm and the particle swarm optimization algorithm in terms of solution speed. 展开更多
关键词 stability network optimization
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