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Synthesis and characterization of biocompatible polyurethanes for controlled release of hydrophobic and

Juichen YANG,Hong CHEN,Yuan YUAN,Debanjan SARKAR,Jie ZHENG

《化学科学与工程前沿（英文）》 2014年 第8卷 第4期   页码 498-510 doi: 10.1007/s11705-014-1451-9

摘要： Design of biocompatible and biodegradable polymer systems for sustained and controlled release of bioactive agents is critical for numerous biomedical applications. Here, we designed, synthesized, and characterized four polyurethane carrier systems for controlled release of model drugs. These polyurethanes are biocompatible and biodegradable because they consist of biocompatible poly(ethylene glycol) or poly(caprolactone diol) as soft segment, linear aliphatic hexamethylene diisocyanate or symmetrical aliphatic cyclic dicyclohexylmethane-4,4′-diisocyanate as hard segment, and biodegradable urethane linkage. They were characterized with Fourier transform infrared spectroscopy, atomic force microscope, and differential scanning calorimetry, whereas their degradation behaviors were investigated in both phosphate buffered saline and enzymatic solutions. By tuning polyurethane segments, different release profiles of hydrophobic and hydrophilic drugs were obtained in the absence and presence of enzymes. Such difference in release profiles was attributed to a complex interplay among structure, hydrophobicity, and degradability of polyurethanes, the size and hydrophobicity of drugs, and drug-polymer interactions. Different drug-polyurethane combinations modulated the distribution and location of the drugs in polymer matrix, thus inducing different drug release mechanisms. Our results highlight an important role of segmental structure of the polyurethane as an engineering tool to control drug release.

关键词： phase structure     degradation     polyurethanes     controlled release     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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All-in-one functional supramolecular nanoparticles based on pillar[5]arene for controlled generation,storage and release of singlet oxygen

《化学科学与工程前沿（英文）》 2023年 第17卷 第3期   页码 307-313 doi: 10.1007/s11705-022-2216-5

摘要： The storage and controlled release of singlet oxygen (1O2) have attracted increasing attention due to the wide application and microsecond lifetime of 1O2 in water. Herein we provide an integrated nanoplatform consisting of a diphenylanthracene derivative, a water-soluble pillar[5]arene and a photosensitizer tetrakis(4-hydroxyphenyl)porphyrin (TPP), that may provide the controlled generation, storage and release of singlet oxygen. We design a new diphenylanthracene derivative with two trimethylammonium bromide groups on both ends that can be well recognized by the pillar[5]arene. The formed nanocarriers can be used to load TPP through their supramolecular self-assembly. The resulting nanoparticles show good water-solubility and uniform spherical morphology. After laser irradiation (660 nm), the nanoparticles exhibit excellent ability for the generation and storage of 1O2. When the irradiated nanoparticles are heated above 80 °C, 1O2 can be released from the system. Therefore, in this paper we pioneer the use of noncovalent interaction to integrate the diphenylanthracene derivatives and photosensitizers into one functional system, which provides a new strategy for the controlled generation, storage and release of singlet oxygen. We believe this groundbreaking strategy will have a great potential in providing necessary amounts of 1O2 for the photodynamic therapy of tumors in dark.

关键词： storage and controlled release of singlet oxygen     supramolecular nanoparticles     noncovalent interactions     pillararenes     diphenylanthracene     photosensitizers    

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Controlled drug release of 5-amino salicylic acid by poly(2-hydroxyethylmethacrylate) grafted agar

G. Usha RANI,Kartick Prasad DEY,Srijita BHARTI,Sumit MISHRA

《化学科学与工程前沿（英文）》 2014年 第8卷 第4期   页码 465-470 doi: 10.1007/s11705-014-1452-8

摘要： The utilization of poly (2-hydroxyethylmethacrylate) grafted agar (Ag-g-P(HEMA)) as a matrix for the controlled release of 5-aminosalicylic acid was investigated. Grafted copolymers of 2-hydroxyethylmethacrylate (HEMA) monomers on agar were synthesized by microwave assisted method. drug release studies were performed at pH values of 2 and 7 in order to investigate the possibility of pH triggered release for colon targeted drug delivery. Further, the percent grafting . (the time taken for release of 50% of the enclosed drug) value was studied and the results indicate that it may be possible to develop a programmable drug release matrix based on grafted polysaccharide. Ag-g-P(HEMA) appears to be a useful matrix for controlled release.

关键词： agar     controlled drug release     5-Amino salicylic acid     poly(2-hydroxyethylmethacrylate) grafted agar    

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Correction to: Highly degradable chitosan-montmorillonite (MMT) nanocomposite hydrogel for controlledfertilizer release

《环境科学与工程前沿（英文）》 2023年 第17卷 第8期 doi: 10.1007/s11783-023-1704-2

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Biodegradable polymethacrylic acid grafted psyllium for controlled drug delivery systems

Ranvijay KUMAR, Kaushlendra SHARMA

《化学科学与工程前沿（英文）》 2013年 第7卷 第1期   页码 116-122 doi: 10.1007/s11705-013-1310-0

摘要： Polymethacrylic acid (PMA) was synthesized on the backbone of psyllium (Psy) by a microwave assisted method to prepare polymeric grafted materials designated as (Psy- -PMA). Various grades of Psy- -PMA were prepared by changing the degree of grafting from 35%–58% and the materials were then made into tablets. Swelling and biodegradability studies of the tablets were carried out. Acetyl salicylic acid was incorporated in the various Psy- -PMA samples and tablets were prepared to study the in vitro drug release in acidic (pH= 4), neutral (pH= 7), and basic (pH= 9) media. In the acidic medium, the swelling was more than 1300%. In addition, the biodegradable Psy- -PMA had the highest drug release in the acidic medium. This may be attributed to Fickian diffusion since the drug and the medium in which it was released have the same acidic nature.

关键词： psyllium     acetyl salicylic acid     in-vitro drug release     swelling     biodegradation    

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具有泵送控释性能的肠靶向Janus型双腔室海藻酸钙基微胶囊 Article

温霜, 巨晓洁, 刘文英, 刘玉琼, 蒲兴群, 刘壮, 汪伟, 谢锐, Yousef Faraj, 褚良银

《工程（英文）》 2023年 第24卷 第5期   页码 114-125 doi: 10.1016/j.eng.2022.05.021

摘要：

本文成功开发了一种具有泵送控释特性的θ形双腔室肠靶向海藻酸钙基微胶囊，囊壁为海藻酸钙-壳聚糖/精蛋白/二氧化硅（ACPSi）复合壳，为封装的药物在胃环境中提供了良好保护，实现药物的肠靶向释放。该θ形微胶囊由含药室和助推室两个腔室组成：含药室负载疏水药物吲哚美辛，其囊壁内嵌肠溶性
羟丙甲基纤维素邻苯二甲酸酯（HPMCP）微球，作为“微阀门”（micro-valves）；助推室包封助推剂聚丙烯酸（PAA），在肠液环境中，PAA发生溶胀，可提高吲哚美辛释放速率。结果显示，载药的θ-ACPSi 微胶囊在模拟胃液（pH值为2.5）中，吲哚美辛的释放率小于1%。然而，进入模拟肠液（pH值为6.8）时，含药室囊壁中的HPMCP微球溶解，释药“微通道”（microchannel）被打开，同时助推室中的PAA发生溶胀，为药物的释放提供推动力。结果，吲哚美辛在小肠中以恒定的速度释放60%以上。因此，该θ-ACPSi 微胶囊具有良好的泵送和肠靶向控释性能，为口服肠道靶向给药系统的开发提供了一种新策略。

关键词： 微胶囊     海藻酸钙     肠靶向递送     泵送性能     控制释放    

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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    

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Design of nanocarriers for efficient cellular uptake and endosomal release of small molecule and nucleic

Vaibhav Mundra, Ram I. Mahato

《化学科学与工程前沿（英文）》 2014年 第8卷 第4期   页码 387-404 doi: 10.1007/s11705-014-1457-3

摘要： There are many challenges in developing efficient and target specific delivery systems of small molecule and nucleic acid drugs. Cell membrane presents one of the major barriers for the penetration of hydrophilic macromolecules across the plasma membrane. Nanocarriers have been designed to enhance their cellular uptake via endocytosis but following their cellular uptake, endosomal escape is the rate limiting step which restricts the value associated with the enhanced uptake by nanocarriers. Viruses are an excellent model for efficient cytosolic delivery by nanocarriers. Viruses exploit intracellular cues to release the genome to cytosol. In this review, we first discuss different endocytic uptake pathways and endosomal escape mechanisms. We then summarize the existing tools for studying the intracellular trafficking of nanocarriers. Finally, we highlight the important design elements of recent virus-based nanocarriers for efficient cellular uptake and endosomal escape.

关键词： nanocarrier     cellular uptake     endosomal release     nucleic acid drug    

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Study on the NOx release rule along the boiler during pulverized coal combustion

JIN Jing, ZHANG Zhongxiao, LI Ruiyang

《能源前沿（英文）》 2007年 第1卷 第1期   页码 91-95 doi: 10.1007/s11708-007-0009-7

摘要： Numerical simulation and experimental study on NO release along the boiler during pulverized coal combustion have been conducted. With the increase of temperature the NO emission increased and the peak value of NO release moved forward. But when the temperature increased to a certain degree, NO emission began to reduce. NO emission increased with the increase of nitrogen content of coal. The peak value of NO release moved backwards with the increase of coal rank. NO emission increased obviously with the increase of stoichiometric ratio. There existed a critical average diameter of the pulverized coal (). If "d, NO emission reduced with the decrease of pulverized coal size. If >, NO emission reduced with the increase of the pulverized coal size. The results showed that the simulation results are in agreement with the experimental results for concentration distribution of NO along the axis of the furnace.
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Capacity estimation and preliminary strategy for reducing the release of dioxins in China

YU Gang, ZHANG Qing, HUANG Jun, CAI Zhenxiao, SUI Qian

《环境科学与工程前沿（英文）》 2007年 第1卷 第1期   页码 13-17 doi: 10.1007/s11783-007-0002-8

摘要： As a party of the Stockholm Convention on Persistent Organic Pollutants, China must submit its national implementation plan (NIP) for this convention. The strategy and action plan for reducing the release of dioxins in China are the most important components of the NIP. Three problems are key points for developing such strategy and action plan what are the key sources for applying the best available technology/best environmental practice (BAT/BEP) to reduce the release of dioxins? How about the capacity for reducing the dioxins release from the key sources? Where are the areas of priority for applying BAT/BEP? This paper shows the efforts towards the solution of these problems. The list of key sources covering about half of the total dioxins release was determined considering four criteria. The capacity of key sources were estimated based on the difference between the emission factor corresponding to the actual situation in 2004 and that corresponding to the scenario that all key sources have been applied BAT/BEP to reduce the dioxins release. The priority analysis using the geographical information system (GIS) tool has revealed that eastern provinces should be of high priority in the future reduction activities of dioxins release in China.

关键词： GIS     difference     capacity     scenario     implementation    

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南方双季稻区冬油菜早熟品种选育和机械栽培研究进展

官春云,陈社员,吴明亮

《中国工程科学》 2010年 第12卷 第2期   页码 4-10

摘要：

为促进南方双季稻区冬油菜生产的发展，选育出油菜早熟品种和实行机械栽培是生产急需解决的两大问题。课题组经过近5年的系统研究，现已成功选育出5个早熟、双低、抗病、高含油量的油菜新组合（品系）。成功研制了适合油菜免耕（浅耕）直播要求的2BYF（D）—6型油菜免耕直播联合播种机，并配套研究了适合直播油菜要求的一次性施用控释肥；同时配合农艺上的催熟剂的开发与使用，研制了与高密度早熟油菜品种相配套的4YC-200油菜联合收割机。形成了在南方双季稻区机械化种植油菜农艺操作规程。通过以上集成技术的实施，实现了油菜种植成本降低，种植面积扩大，油菜产量和种植经济效益的提高，试验测定，通过机械化种植油菜，每公顷纯收入可增至4 500元以上。

关键词： 双季稻     油菜     早熟品种     机械栽培     控释肥     催熟剂    

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Phosphorus release potential and pollution characteristics of sediment in downstream Nansi Lake, China

Zhijian LI, Qinyan YUE, Baoyu GAO, Yanwen WANG, Qing LIU

《环境科学与工程前沿（英文）》 2012年 第6卷 第2期   页码 162-170 doi: 10.1007/s11783-011-0313-7

摘要： The research aimed to evaluate present and potential phosphorous pollution due to high sedimentary phosphorus load and release from sediment, when external phosphorus was reduced in downstream Nansi Lake. Pollution load of the sediment and overlying water was investigated. Kinetics and isotherms of adsorption/release of sedimentary phosphorus were studied to determine equilibrium phosphate concentration (EPC ) and release potential. Kinetics of phosphorus adsorption on sediment and release from sediment were well described by both the pseudo-first-order rate equation and the pseudo-second-order rate equation, but more appropriate to the pseudo-second-order rate equation with the adsorption/release capacity more close to the measured values, suggesting that the processes were chemically rate controlled and dependent on adsorption capacity. Soluble reactive phosphorus (SRP) sorption isotherms on sediment were best fitted by the modified Langmuir model indicating a monolayer adsorption. By comparing EPC and SRP of water, the status (adsorption, releasing or in equilibrium) of sediment phosphorus could be determined. The sediments at site S1, S3, S4, S5, and S7 where the EPC s were greater than the SRPs, had a potential to release phosphorus into the water column. However, those sediments at S9, S10, and S12, where the EPC s were approximately equal to the SRPs, were in impermanent equilibrium with overlying water in status of phosphorus, the sediments can be likely to release phosphorus to the water column once the equilibrium was broken. Therefore, sedimentary phosphorus can be a secondary pollution source in downstream Nansi Lake.

关键词： Nansi Lake     sediment     phosphorus     release potential     equilibrium phosphate concentration    

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Size-controlled green synthesis of silver nanoparticles assisted by L-cysteine

Wenchao Zhang,Lin Zhang,Yan Sun

《化学科学与工程前沿（英文）》 2015年 第9卷 第4期   页码 494-500 doi: 10.1007/s11705-015-1527-1

摘要： A green and size-controlled synthesis of silver nanoparticles (Ag NPs) in aqueous solution with the assistance of L-cysteine is presented. The size of Ag NPs decreases with the increase of L-cysteine concentration, and thus can be controlled by adjusting L-cysteine concentration. TEM analysis shows that Ag NPs with an average size of 3 nm can be produced in the presence of 1.0 mmol/L L-cysteine, about one sixth of the size of Ag NPs obtained in the absence of L-cysteine (17 nm). The as-synthesized silver colloidal solution is stable and can be stored at room temperature for at least two months without any precipitation. This L-cysteine assisted method is simple, feasible and efficient, and would facilitate the production and application of Ag NPs.

关键词： nanoparticles     silver     L-cysteine     size distribution     synthesis    

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Analysis and stabilization control of a voltage source controlled wind farm under weak grid conditions

《能源前沿（英文）》 2022年 第16卷 第6期   页码 943-955 doi: 10.1007/s11708-021-0793-5

摘要： This paper investigates and discusses the interaction stability issues of a wind farm with weak grid connections, where the wind turbines (WTs) are controlled by a new type of converter control strategy referred to as the voltage source (VS) control. The primary intention of the VS control method is to achieve the high-quality inertial response capability of a single WT. However, when it is applied to multiple WTs within a wind farm, its weak-grid performance regarding the stability remains concealed and needs to be clarified. To this end, a frequency domain model of the wind farm under the VS control is first developed. Based on this model and the application of a stability margin quantification index, not only the interactions between the wind farm and the weak grid but also those among WTs will be systematically assessed in this paper. A crucial finding is that the inertial response of VS control has negative impacts on the stability margin of the system, and the dominant instability mode is more related to the interactions among the WTs rather than the typical grid-wind farm interaction. Based on this knowledge, a stabilization control strategy is then proposed, aiming for stability improvements of VS control while fulfilling the demand of inertial responses. Finally, all the results are verified by time-domain simulations in power systems computer aided design/electromagnetic transients including DC(PSCAD/EMTDC).

关键词： weak grids     voltage source (VS) control     wind turbine (WT)     stabilization control     wind farm     inertial response    

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标题 作者 时间 类型 操作

Synthesis and characterization of biocompatible polyurethanes for controlled release of hydrophobic and

Juichen YANG,Hong CHEN,Yuan YUAN,Debanjan SARKAR,Jie ZHENG

期刊论文

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

Michelle TRAN,Chun WANG

期刊论文

All-in-one functional supramolecular nanoparticles based on pillar[5]arene for controlled generation,storage and release of singlet oxygen

期刊论文

Controlled drug release of 5-amino salicylic acid by poly(2-hydroxyethylmethacrylate) grafted agar

G. Usha RANI,Kartick Prasad DEY,Srijita BHARTI,Sumit MISHRA

期刊论文

Correction to: Highly degradable chitosan-montmorillonite (MMT) nanocomposite hydrogel for controlledfertilizer release

期刊论文

Biodegradable polymethacrylic acid grafted psyllium for controlled drug delivery systems

Ranvijay KUMAR, Kaushlendra SHARMA

期刊论文

具有泵送控释性能的肠靶向Janus型双腔室海藻酸钙基微胶囊

温霜, 巨晓洁, 刘文英, 刘玉琼, 蒲兴群, 刘壮, 汪伟, 谢锐, Yousef Faraj, 褚良银

期刊论文

适用于田野调查的加勒比按实蝇信息素聚氯乙烯剂型

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

期刊论文

Design of nanocarriers for efficient cellular uptake and endosomal release of small molecule and nucleic

Vaibhav Mundra, Ram I. Mahato

期刊论文

Study on the NOx release rule along the boiler during pulverized coal combustion

JIN Jing, ZHANG Zhongxiao, LI Ruiyang

期刊论文

Capacity estimation and preliminary strategy for reducing the release of dioxins in China

YU Gang, ZHANG Qing, HUANG Jun, CAI Zhenxiao, SUI Qian

期刊论文

南方双季稻区冬油菜早熟品种选育和机械栽培研究进展

官春云,陈社员,吴明亮

期刊论文

Phosphorus release potential and pollution characteristics of sediment in downstream Nansi Lake, China

Zhijian LI, Qinyan YUE, Baoyu GAO, Yanwen WANG, Qing LIU

期刊论文

Size-controlled green synthesis of silver nanoparticles assisted by L-cysteine

Wenchao Zhang,Lin Zhang,Yan Sun

期刊论文

Analysis and stabilization control of a voltage source controlled wind farm under weak grid conditions

期刊论文