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Nanocrystal technology for drug formulation and delivery

Tzu-Lan CHANG, Honglei ZHAN, Danni LIANG, Jun F. LIANG

《化学科学与工程前沿（英文）》 2015年第9卷第1期页码 1-14 doi: 10.1007/s11705-015-1509-3

摘要： With the development of modern technology like high throughput screening, combinatorial chemistry and computer aid drug design, the drug discovery process has been dramatically accelerated. However, new drug candidates often exhibit poor aqueous or even organic medium solubility. Additionally, many of them may have low dissolution velocity and low oral bioavailability. Nanocrystal formulation sheds new light on advanced drug development. Due to small (nano- or micro- meters) sizes, the increased surface-volume ratio leads to dramatically enhanced drug dissolution velocity and saturation solubility. The simplicity in preparation and the potential for various administration routes allow drug nanocrystals to be a novel drug delivery system for specific diseases (i.e. cancer). In addition to the comprehensive review of different technologies and methods in drug nanocrystal preparation, suspension, and stabilization, we will also compare nano- and micro-sized drug crystals in pharmaceutical applications and discuss current nanocrystal drugs on the market and their limitations.

关键词： drug nanocrystal nanotechnology formulation bioavailability stabilizers drug delivery

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Semi-solid materials for controlled release drug formulation: current status and future prospects

Michelle TRAN,Chun WANG

《化学科学与工程前沿（英文）》 2014年第8卷第2期页码 225-232 doi: 10.1007/s11705-014-1429-7

摘要： Semi-solid materials represent an important category of inactive ingredients (excipients) of pharmaceutical products. Here we review several common semi-solid polymers currently used in the controlled release formulations of many drugs. These polymers are selected based on their importance and broad scope of application in FDA-approved drug products and include several polysaccharides (cellulose, starch, chitosan, alginate) and carbomers, a group of mucoadhesive synthetic polymers. Glyceride-based polymers used in self-emulsifying drug delivery systems (SEDDS) will also be discussed for its importance in formulating poorly water-soluble drugs. Unique features and advantages of each type of semi-solid materials are discussed and examples of their use in oral delivery of drugs are provided. Finally, future prospects of developing new and better semi-solid excipients are discussed with the objective of facilitating clinical translation.

关键词： controlled release drug delivery semi-solids polymer excipient

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Implementation of total Lagrangian formulation for the elasto-plastic analysis of plane steel frames

Bing XIA, Yuching WU, Zhanfei HUANG

《结构与土木工程前沿（英文）》 2012年第6卷第3期页码 257-266 doi: 10.1007/s11709-012-0163-9

摘要： In this paper, the co-rotational total Lagrangian forms of finite element formulations are derived to perform elasto-plastic analysis for plane steel frames that either experience increasing external loading at ambient temperature or constant external loading at elevated temperatures. Geometric nonlinearities and thermal-expansion effects are considered. A series of programs were developed based on these formulations. To verify the accuracy and efficiency of the nonlinear finite element programs, numerical benchmark tests were performed, and the results from these tests are in a good agreement with the literature. The effects of the nonlinear terms of the stiffness matrices on the computational results were investigated in detail. It was also demonstrated that the influence of geometric nonlinearities on the incremental steps of the finite element analysis for plane steel frames in the presence of fire is limited.

关键词： co-rotational total Lagrangian geometrical nonlinearity fire elasto-plastic

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A novel finite element formulation for static bending analysis of functionally graded porous sandwich

Van Chinh NGUYEN; Trung Thanh TRAN; Trung NGUYEN-THOI; Quoc-Hoa PHAM

《结构与土木工程前沿（英文）》 2022年第16卷第12期页码 1599-1620 doi: 10.1007/s11709-022-0891-4

摘要： This article aims to propose a finite element formulation based on Quasi-3D theory for the static bending analysis of functionally graded porous (FGP) sandwich plates. The FGP sandwich plates consist of three layers including the bottom skin of homogeneous metal, the top skin of fully ceramic and the FGP core layer with uneven porosity distribution. A quadrilateral (Q4) element with nine degrees of freedom (DOFs) per node is derived and employed in analyzing the static bending response of the plate under uniform and/or sinusoidally distributed loads. The accuracy of the present finite element formulation is verified by comparing the obtained numerical results with the published results in the literature. Then, some numerical examples are performed to examine the effects of the parameters including power-law index k and porosity coefficient

ξ

on the static bending response of rectangular FGP sandwich plates. In addition, a problem with a complicated L-shape model is conducted to illustrate the superiority of the proposed finite element method.

关键词： sandwich plates functionally graded porous static bending Quasi-3D theory Q4 element

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Robust isogeometric topology optimization for piezoelectric actuators with uniform manufacturability

《机械工程前沿（英文）》 2022年第17卷第2期 doi: 10.1007/s11465-022-0683-5

摘要： Piezoelectric actuators have received substantial attention among the industry and academia due to quick responses, such as high output force, high stiffness, high accuracy, and precision. However, the design of piezoelectric actuators always suffers from the emergence of several localized hinges with only one-node connection, which have difficulty satisfying manufacturing and machining requirements (from the over- or under-etching devices). The main purpose of the current paper is to propose a robust isogeometric topology optimization (RITO) method for the design of piezoelectric actuators, which can effectively remove the critical issue induced by one-node connected hinges and simultaneously maintain uniform manufacturability in the optimized topologies. In RITO, the isogeometric analysis replacing the conventional finite element method is applied to compute the unknown electro elastic fields in piezoelectric materials, which can improve numerical accuracy and then enhance iterative stability. The erode–dilate operator is introduced in topology representation to construct the eroded, intermediate, and dilated density distribution functions by non-uniform rational B-splines. Finally, the RITO formulation for the design of piezoelectric materials is developed, and several numerical examples are performed to test the effectiveness and efficiency of the proposed RITO method.

关键词： piezoelectric actuator isogeometric topology optimization uniform manufacturability robust formulation density distribution function

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Controlling interstory drift ratio profiles via topology optimization strategies

《结构与土木工程前沿（英文）》 2023年第17卷第2期页码 165-178 doi: 10.1007/s11709-022-0892-3

摘要： An approach to control the profiles of interstory drift ratios along the height of building structures via topology optimization is proposed herein. The theoretical foundation of the proposed approach involves solving a min–max optimization problem to suppress the maximum interstory drift ratio among all stories. Two formulations are suggested: one inherits the bound formulation and the other utilizes a p-norm function to aggregate all individual interstory drift ratios. The proposed methodology can shape the interstory drift ratio profiles into inverted triangular or quadratic patterns because it realizes profile control using a group of shape weight coefficients. The proposed formulations are validated via a series of numerical examples. The disparity between the two formulations is clear. The optimization results show the optimal structural features for controlling the interstory drift ratios under different requirements.

关键词： interstory drift ratio aggregation function bound formulation min–max problem topology optimization

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An assessment of surrogate fuel using Bayesian multiple kernel learning model in sight of sooting tendency

《能源前沿（英文）》 2022年第16卷第2期页码 277-291 doi: 10.1007/s11708-021-0731-6

摘要： An integrated and systematic database of sooting tendency with more than 190 kinds of fuels was obtained through a series of experimental investigations. The laser-induced incandescence (LII) method was used to acquire the 2D distribution of soot volume fraction, and an apparatus-independent yield sooting index (YSI) was experimentally obtained. Based on the database, a novel predicting model of YSI values for surrogate fuels was proposed with the application of a machine learning method, named the Bayesian multiple kernel learning (BMKL) model. A high correlation coefficient (0.986) between measured YSIs and predicted values with the BMKL model was obtained, indicating that the BMKL model had a reliable and accurate predictive capacity for YSI values of surrogate fuels. The BMKL model provides an accurate and low-cost approach to assess surrogate performances of diesel, jet fuel, and biodiesel in terms of sooting tendency. Particularly, this model is one of the first attempts to predict the sooting tendencies of surrogate fuels that concurrently contain hydrocarbon and oxygenated components and shows a satisfying matching level. During surrogate formulation, the BMKL model can be used to shrink the surrogate candidate list in terms of sooting tendency and ensure the optimal surrogate has a satisfying matching level of soot behaviors. Due to the high accuracy and resolution of YSI prediction, the BMKL model is also capable of providing distinguishing information of sooting tendency for surrogate design.

关键词： sooting tendency yield sooting index Bayesian multiple kernel learning surrogate assessment surrogate formulation

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ISO 18186国际标准的制定及思考

包起帆

《中国工程科学》 2012年第14卷第10期页码 23-26

摘要：

随着我国经济的快速发展和技术水平的不断提高，如何提升我国在国际标准化活动中的影响力和话语权的呼声越来越高。国际标准《ISO 18186∶2011 集装箱-RFID货运标签系统》于2011年由国际标准化组织(ISO)正式发布，成为自我国开始参与国际标准化组织活动以来，在物流、物联网领域首个由中国发起、起草和主导的国际标准。这项国际标准是以“构建包括系统平台建设、软硬件设计、商业化运行模式和系统应用的完整产业链”为技术支撑，沿着“技术专利化、专利标准化、标准国际化”的路线，先形成国家标准GB/T 23678—2009，并同步推进相关国际标准的制定。这里将对国际标准制定的过程和方法进行介绍，分享一些经验，以期为我国创新成果上升，为国际标准提供一些有益帮助。

关键词：国际标准制定集装箱RFID（无线射频识别） ISO 18186

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Controlled drug delivery systems: the next 30 years

Yeonhee YUN,Byung Kook LEE,Kinam PARK

《化学科学与工程前沿（英文）》 2014年第8卷第3期页码 276-279 doi: 10.1007/s11705-014-1426-x

摘要： The drug delivery scientists need to reexamine the advances made during the past 60 years, analyze our current abilities, and design the future technologies that will propel us to achieve the next level of drug delivery technologies. History shows that the first generation (1G) of drug delivery research during 1950–1980 was quite productive, while the second generation (2G) technologies developed during 1980–2010 were not as prolific. The ultimate goal of drug delivery research is to develop clinically useful formulations to treat various diseases. Effective drug delivery systems can be developed by overcoming formulation barriers and/or biological barriers. The engineering approach has a limit in solving the problem, if biological difficulties are not clearly identified and understood. The third generation (3G) drug delivery systems will have to focus on understanding the biological barriers so that they can be overcome by engineering manipulation of the drug delivery systems. Advances in the next 30 years will be most accelerated by starting open dialogues without any preconceived ideas on drug delivery technologies. The new generation of drug delivery scientists needs to be aware of the successes and limitations of the existing technologies to design the new technologies for meaningful advances in the future.

关键词： drug delivery history formulation barriers nanotechnology clinical product

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Non linear modeling of three-dimensional reinforced and fiber concrete structures

Fatiha IGUETOULENE, Youcef BOUAFIA, Mohand Said KACHI

《结构与土木工程前沿（英文）》 2018年第12卷第4期页码 439-453 doi: 10.1007/s11709-017-0433-7

摘要： Under the effect of the ascending loading, the behavior of reinforced concrete structures is rather non linear. Research in industry and science aims to extend forward the use of non-linear calculation of fiber concrete for structural parts such as columns, veils and pious, as the fiber concrete is more ductile behavior then the classical concrete behavior. The formulation of the element has been established for modeling the nonlinear behavior of elastic structures in three dimensions, based on the displacement method. For the behavior of concrete and fiber concrete compressive and tensile strength (stress-strain) the uniaxial formulation is used. For steel bi-linear relationship is used. The approach is based on the discretization of the cross section trapezoidal tables. Forming the stiffness matrix of the section, the integral of the surface is calculated as the sum of the integrals on each of the cutting trapezoids. To integrate on the trapeze we have adopted the type of Simpson integration scheme.

关键词： numerical modeling column and beam nonlinear analysis fibers pious reinforcement 3D formulation response load-deflection

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绿色表面活性剂在农药加工中的应用

高楠,张春华,张宗俭

《中国工程科学》 2009年第11卷第4期页码 36-38

摘要：

对绿色表面活性剂在农药加工中的应用进行了简要介绍，对应用脂肪醇聚氧乙烯醚（AEO）、脂肪醇聚氧乙烯醚硫酸盐（AES）、α-烯基磺酸盐（AOS）、烷基糖苷（APG）的农药制剂进行了开发，并与传统表面活性剂进行比较，提出此类表面活性剂在农药加工中的应用对于环境保护具有重要意义。

关键词：绿色表面活性剂农药加工环境保护

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适用于田野调查的加勒比按实蝇信息素聚氯乙烯剂型 Article

Daniel Kuzmich, Zachary A. Kawagoe, Spencer S. Walse

《工程（英文）》 2021年第7卷第11期页码 1646-1650 doi: 10.1016/j.eng.2020.09.011

摘要：

实蝇威胁着世界各地的水果生产。在美洲，作为害虫治理计划的一部分，用诱捕网络监测按实蝇（Anastrepha）的种群。在本文中，我们研究了利用雄性加勒比按实蝇（Loew）信息素、(±)-anastrephin 和(±)-epianastrephin，形成聚氯乙烯（PVC）聚合物基质引诱剂进行陷阱部署的制备方法。PVC聚合物圆盘（100 mg）分别含有10%（质量分数）的(±)-epianastrephin 和(±)-anastrephin，天然存在的非对映体比例为7∶3。将信息素从圆盘排放到空气的这一过程作为测量非生物环境参数、绝对湿度和温度的函数。从基质释放信息素的这一扩散控制机制得到了动力学数据的支持，一级反应速率常数随着温度的降低（从30 ℃降低到15 ℃）而降低了约1/10。因此，从圆盘释放的挥发性信息素能够在田野调查中持续数周。可以很容易地将这种动力学方法推广至聚合物基质的其他引诱剂的扩散控制释放中，在进行田野生物调查之前，可以对潜在的环境损失进行实验室预测。

关键词：按实蝇按实蝇信息素 Epianastrephin PVC引诱剂控制释放