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聚乙烯醇薄膜中茶多酚向水中释放的不同动力学模型比较分析 预览
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作者 陈晨伟 许哲玮 +4 位作者 马亚蕊 谢晶 张勤军 唐智鹏 杨福馨 《食品科学》 EI CAS CSCD 北大核心 2019年第3期24-29,共6页
研究聚乙烯醇薄膜中茶多酚向水中释放的不同动力学模型表征。通过释放实验研究了薄膜中茶多酚向水中的释放规律,基于4种动力学模型对实验数据进行拟合表征,比较分析了不同模型的拟合效果。结果表明:茶多酚释放率随薄膜中茶多酚质量浓度... 研究聚乙烯醇薄膜中茶多酚向水中释放的不同动力学模型表征。通过释放实验研究了薄膜中茶多酚向水中的释放规律,基于4种动力学模型对实验数据进行拟合表征,比较分析了不同模型的拟合效果。结果表明:茶多酚释放率随薄膜中茶多酚质量浓度的增加而降低。对比不同模型的拟合效果,Fickian模型和Fickian+一级动力学模型可以很好地模拟茶多酚的释放(R^2≥97.27),后者更优;Weibull模型的拟合效果较前两个模型差(R^2≥85.21),但是该模型可以很好地模拟从释放开始到平衡初期茶多酚的释放(R^2≥92.20);短期释放模型的拟合效果较好(R^2≥91.32),但其扩散系数与由Fickian模型和Fickian+一级动力学模型得到的扩散系数相差较大。总的来看,Fickian+一级动力学模型模拟效果最好,Fickian模型次之,Weibull模型模拟从释放开始到平衡初期过程的效果较好,短期释放模型不适合用于模拟评估聚乙烯醇薄膜中茶多酚整个释放过程中的释放性能。 展开更多
关键词 聚乙烯醇 茶多酚 释放 释放动力学 动力学模型
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Photo-controlled release of paclitaxel and model drugs from RNA pyramids
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作者 Congcong Xu Hui Li +4 位作者 Kaiming Zhang Daniel W.Binzel Hongran Yin Wah Chiu Peixuan Guo 《纳米研究:英文版》 SCIE EI CAS CSCD 2019年第1期41-48,共8页
Stimuli-resp on sive release of drugs from a nano carrier in spatial-,temporal-,and dosage-controlled fashi ons is of great interest in the pharmaceutical industry.Paclitaxel is one of the most effective and popular c... Stimuli-resp on sive release of drugs from a nano carrier in spatial-,temporal-,and dosage-controlled fashi ons is of great interest in the pharmaceutical industry.Paclitaxel is one of the most effective and popular chemotherapeutic drugs against a number of cancers such as metastatic or non metastatic breast can cer,non-small cell lung can cer,refractory ovaria n cancer,AIDS-related Kaposi's sarcoma,and head and neck can cers.Here,by taki ng the adva ntage of RNA nanotechno logy in biomedical and material scie nee,we developed a three-dime nsional pyramid-shaped RNA nanocage for a photocontrolled release of cargo,using paclitaxel as a model drug.The light-triggered release of paclitaxel or fluorophore Cy5 was achieved by incorporation of photocleavable spacers into the RNA nanoparticles.Upon irradiation with ultraviolet light,cargos were rapidly released(within 5 min).In vitro treatment of breast can cer cells with the RNA nano particles harbori ng photocleavable paclitaxel showed higher cytotoxicity as compared to RNA nanoparticles without the photocleavable spacer.The methodology provides proof of con cept for the applicati on of the light-triggered con trolled release of drugs from RNA nano cages. 展开更多
关键词 RNA NANOTECHNOLOGY controlled release PACLITAXEL DRUG delivery RNA nanoparticles Phi29 three-way JUNCTION
RTTS安全接头脱手解卡技术 预览
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作者 赵宇光 《油气井测试》 2019年第3期21-25,共5页
APR测试施工过程中,由于井筒质量、井下工具、施工工艺等因素造成管柱被卡,尝试管柱整体解卡不成功时,优选采取将RTTS封隔器以上的RTTS安全接头进行脱手解卡措施,提出安全接头以上管柱,使留在井筒内的管柱工具最少,以便后续处理。结合... APR测试施工过程中,由于井筒质量、井下工具、施工工艺等因素造成管柱被卡,尝试管柱整体解卡不成功时,优选采取将RTTS封隔器以上的RTTS安全接头进行脱手解卡措施,提出安全接头以上管柱,使留在井筒内的管柱工具最少,以便后续处理。结合工作原理和现场案例,完善了RTTS安全接头脱手作业操作程序,现场2口井按照此操作程序实现了RTTS安全接头脱手,施工成功率100%,为同类APR测试管柱解卡作业提供了技术借鉴。 展开更多
关键词 钻柱地层测试 RTTS安全接头 封隔器遇卡 脱手 解卡 操作方法
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Theranostic nanoparticles with tumor-specific enzyme-triggered size reduction and drug release to perform photothermal therapy for breast cancer treatment
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作者 Rui Liu Chuan Hu +2 位作者 Yuanyuan Yang Jingqing Zhang Huile Gao 《药学学报:英文版》 CSCD 2019年第2期410-420,共11页
Although progress has been indeed made by nanomedicines, their efficacies for cancer treatment remain low, consequently leading to failures in translation to clinic. To improve the drug delivery efficiency,nanoparticl... Although progress has been indeed made by nanomedicines, their efficacies for cancer treatment remain low, consequently leading to failures in translation to clinic. To improve the drug delivery efficiency,nanoparticles need to change size so as to fully utilize the enhanced permeability and retention(EPR) effect of solid tumor, which is the golden principle of nanoparticles used for cancer treatment. Herein, we employed cationic small-sized red emission bovine serum albumin(BSA) protected gold nanocluster(Au NC@CBSA,21.06 nm) to both load indocyanine green(ICG) and act as imaging probe to realize theranostic. Then Au NC@CBSA-ICG was fabricated with negatively charged hyaluronic acid(HA) to form Au NC@CBSAICG@HA, which was about 200 nm to easily retain at tumor site and could be degraded by tumor-specific hyaluronidase into small nanoparticles for deep tumor penetration. The HA shell also endowed Au NC@CBSA-ICG@HA with actively targeting ability and hyaluronidase-dependent drug release. Furthermore, the quenching and recovery of fluorescence revealed the interaction between ICG and carrier, which was essential for the investigation of pharmacokinetic profiles. No matter in vitro or in vivo, Au NC@CBSAICG@HA showed markedly anti-tumor effect, and could suppress 95.0% of tumor growth on mice breast cancer model. All results demonstrated Au NC@CBSA-ICG@HA was potential for breast cancer therapy. 展开更多
关键词 Size-shrinkage Drug release PHOTOTHERMAL therapy THERANOSTIC BREAST cancer
脱扣器执行元件的动态仿真和试验验证 预览
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作者 耿立新 江镇伟 《电器与能效管理技术》 2019年第10期31-35,共5页
针对一种脱扣器执行元件进行了动态仿真和试验验证。应用Maxwell电磁仿真软件,计算动铁心在不同激励电压作用下磁力随气隙的变化情况;采用Maxwell和ADAMS联合仿真方法,模拟了脱扣器执行元件的动态运动过程。最后,试验验证了执行机构释... 针对一种脱扣器执行元件进行了动态仿真和试验验证。应用Maxwell电磁仿真软件,计算动铁心在不同激励电压作用下磁力随气隙的变化情况;采用Maxwell和ADAMS联合仿真方法,模拟了脱扣器执行元件的动态运动过程。最后,试验验证了执行机构释放力值与释放行程的关系,为脱扣器执行元件的优化设计提供了理论依据和数据支撑。 展开更多
关键词 脱扣器 执行元件 MAXWELL ADAMS 动态运动过程
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天铁高炉电动鼓风机应用效能的提升 预览
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作者 王岳峰 《天津冶金》 CAS 2019年第3期34-37,共4页
通过分析高炉配套的AV-90电动鼓风机的工作参数、老区三座高炉所需风量和风压,制定了以一台AV-90电动鼓风机代替老区三台小鼓风机为老区三座高炉提供冷风的供风方案,实施后解决了旧风机风压不足、风量过大、无法升级、防喘振保护不全、... 通过分析高炉配套的AV-90电动鼓风机的工作参数、老区三座高炉所需风量和风压,制定了以一台AV-90电动鼓风机代替老区三台小鼓风机为老区三座高炉提供冷风的供风方案,实施后解决了旧风机风压不足、风量过大、无法升级、防喘振保护不全、调节功能不完善等问题。 展开更多
关键词 电动鼓风机 风量 风压 放散 高炉 喘振
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Interleukin-6 secretion is limited by self-signaling in endosomes
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作者 Danielle R.J.Verboogen Natalia H.Revelo +1 位作者 Martin ter Beest Geert van den Bogaart 《分子细胞生物学报:英文版》 SCIE CAS CSCD 2019年第2期144-157,共14页
Cells producing cytokines often express the receptor for the same cytokine, which makes them prone to autocrine signaling. How cytokine release and signaling are regulated in the same cell is not understood? In this s... Cells producing cytokines often express the receptor for the same cytokine, which makes them prone to autocrine signaling. How cytokine release and signaling are regulated in the same cell is not understood? In this study, we demonstrate that signaling by exogenous and self-synthesized inflammatory cytokine interleukin-6 (IL-6) within endosomal compartments acts as a cellular brake that limits the synthesis of IL-6. Our data show that IL-6 is internalized by dendritic cells and signals from endosomal compartments containing the IL-6 receptor. Newly synthesized IL-6 also traffics via these endosomal compartments and signals in transit to the plasma membrane. This allows activation of STAT3 which in turn limits toll-like receptor 4 stimulant lipopolysaccharide (LPS) triggered transcription of IL-6. Long-term exposure to LPS removes this brake via inhibition of STAT3 by increased expression of suppressor of cytokine signaling 3 and results in fully fledged IL-6 production. This transient regulation could prevent excessive IL-6 production during early infections. 展开更多
关键词 membrane TRAFFICKING CYTOKINE release EXOCYTOSIS INTERLEUKIN-6 endosomal SIGNALING
丹参饮对气虚血瘀模型大鼠的血小板生物学 预览
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作者 张玉昆 冯月男 +2 位作者 卞敬琦 肖洪彬 牛雯颖 《世界中医药》 CAS 2019年第4期848-851,858共5页
目的:观察丹参饮对气虚血瘀模型大鼠血小板生物学的影响,从血小板动态变化上探讨丹参饮作用机制。方法:选取SD大鼠40只为研究对象,一次性向气管内注射博莱霉素生理盐水溶液复制气虚血瘀模型,将40只SD大鼠随机分为空白对照组、气虚血瘀... 目的:观察丹参饮对气虚血瘀模型大鼠血小板生物学的影响,从血小板动态变化上探讨丹参饮作用机制。方法:选取SD大鼠40只为研究对象,一次性向气管内注射博莱霉素生理盐水溶液复制气虚血瘀模型,将40只SD大鼠随机分为空白对照组、气虚血瘀模型组、丹参饮高剂量组(3.6g/kg)、低剂量组(0.9g/kg),每组10只。造模后第2天开始灌胃给药,连续21d,末次给药1h后5%水合氯醛麻醉,腹主动脉取血,检测全血黏度、血浆黏度、血小板参数、血小板活化黏附、聚集、释放以及纤溶相关指标。结果:丹参饮可显著降低模型大鼠中低切变率下的全血黏度和血浆黏度,差异有统计学意义(P<0.05),可显著降低PDW和MPV血小板相关参数,差异有统计学意义(P<0.05);可显著升高环磷酸腺苷(cAMP)水平,差异有统计学意义(P<0.05),降低环磷酸鸟苷(cGMP)、β-血小板球蛋白(β-TG)血小板第4因子(PF4)和纤溶酶原激活物抑制剂-1(PAI-1)水平,差异有统计学意义(P<0.05),延长凝血酶原时间(PT)和凝血酶时间(TT),差异有统计学意义(P<0.05)。结论:丹参饮可能主要通过改善血小板聚集、抑制凝血及血小板释放亢进的状态方面达到降低全血黏度,改善气虚血瘀状态。 展开更多
关键词 丹参饮 气虚血瘀 血液流变学 血小板 黏附 聚集 释放 纤溶
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Sustained co-delivery of gemcitabine and cis-platinum via biodegradable thermo-sensitive hydrogel for synergistic combination therapy of pancreatic cancer
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作者 Kun Shi Bingxin Xue +5 位作者 Yanpeng Jia Liping Yuan Ruxia Han Fan Yang Jinrong Peng Zhiyong Qian 《纳米研究:英文版》 SCIE EI CAS CSCD 2019年第6期1389-1399,共11页
Pancreatic cancer is one of the most devastating cancers with poor prognosis and no significant change in the survival rate over the past decades.Localized targeted drug delivery through interventional endoscopic ultr... Pancreatic cancer is one of the most devastating cancers with poor prognosis and no significant change in the survival rate over the past decades.Localized targeted drug delivery through interventional endoscopic ultrasonography-guided fine-needle injection (EUS-FNI) is an attractive and minimally invasive strategy for inoperable pancreatic cancer.An injectable in-situ formed long-lasting drug delivery system is a promising alternative for the localized treatment of pancreatic cancer via EUS-FNI.Here,a biodegradable thermo-sensitive copolymer hydrogel for the co-delivery of anticancer agents gemcitabine (GEM) and cis-platinum (DDP) was developed.This hydrogel is a free flowable liquid at room temperature that changes into a semi-solid hydrogel following injection in response to the physiological temperature.Both in vitro and in vivo drug release behaviors indicate sustained drug release of this delivery system.Synergistic cellular proliferation inhibition and desirable apoptosis promotion have been found when pancreatic cancer Bxpc-3 cells were co-cultured with this GEM-DDP/hydrogel system.After a single intratumoral injection,the dual-drug loaded hydrogel formulation exhibited superior anti-tumor efficacy and minimized systemic side effect on pancreatic cancer xenograft mouse model in comparison to the intravenously injected free GEM and DDP combination.In addition,a strong synergistic therapeutic effect of the GEM-DDP/hydrogel system against pancreatic cancer has been found in vitro and in vivo compared to the single-drug loaded hydrogel composites.The obtained findings suggest this developed thermo-sensitive copolymer hydrogel system as a potential universal carrier for the localized targeted delivery of multi-drugs,for use in a variety of inoperable solid tumors. 展开更多
关键词 localized drug delivery SUSTAINED release THERMO-SENSITIVE HYDROGEL combination therapy pancreatic cancer
Development and Application of Coated Fertilizer in Japan 预览
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作者 Hiroshi Aoki Yuichi Sekiguti 《食品科学与工程:英文版(美国)》 2019年第4期142-152,共11页
The fertilizer industry faces a continuing challenge to improve its products to increase the fertilizer use efficiency and to minimize any possible adverse environmental impact.For this purpose,studies on the developm... The fertilizer industry faces a continuing challenge to improve its products to increase the fertilizer use efficiency and to minimize any possible adverse environmental impact.For this purpose,studies on the development of coated fertilizers have been done all over the world.In this paper,we are to introduce our coated urea“MEISTER”as the sophisticated fertilizer,with explaining the features and applications in actual fields.“MEISTER”is the coated urea with a mixture of polyolefin and silicate mineral.“MEISTER”has two releasing types.One is the linear type.Another is the sigmoidal type.Release of nitrogen from“MEISTER”mainly depends on temperature which allows precise prediction of nutrient release.Application experiments for rice,Chinese cabbage and long onion are introduced in this paper.Every experiment shows single basal application is possible by using“MEISTER”with keeping yield and high nitrogen recovery.Coated fertilizers show accurate release control of nutrients.The use of coated fertilizers brings:(a)efficient use of fertilizer resources,(b)reduction of environmental load by fertilizer,(c)labor saving.Thus applying coated fertilizers is definitely smart fertilization technology in agriculture.Coated fertilizers seem to closely meet the requirements of an ideal fertilizer.The problem is its high price compared to the normal rapid soluble fertilizer.Unit price of coated fertilizer is expensive on the surface,though total application cost of coated fertilizers is often cheaper than the cost of rapid soluble fertilizers.This sometime disturbs the spread of coated fertilizers.So,we have been trying to make an effort to reduce production cost and doing application enlargement trials of coated fertilizers for becoming more widespread.Through those studies and development,we believe coated fertilizers will contribute to agriculture more in the world. 展开更多
关键词 Coated FERTILIZER release control rice Chinese CABBAGE LONG ONION co-situs NITROGEN use efficiency
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Online scheduling of jobs with kind release times and deadlines on a single machine 预览
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作者 LI Wen-jie MA Ran FENG Qi 《高校应用数学学报:英文版(B辑)》 SCIE CSCD 2019年第1期113-126,共14页
This paper studies online scheduling of jobs with kind release times on a single machine.Here“kind release time”means that in online setting,no jobs can be released when the machine is busy.Each job J has a kind rel... This paper studies online scheduling of jobs with kind release times on a single machine.Here“kind release time”means that in online setting,no jobs can be released when the machine is busy.Each job J has a kind release time r(J)≥0,a processing time p(J)>0 and a deadline d(J)>0.The goal is to determine a schedule which maximizes total processing time (∑p(J)E(J)) or total number (∑E(J)) of the accepted jobs.For the first objective function ∑p(J)E(J),we first present a lower bound √2,and then provide an online algorithm LEJ with a competitive ratio of 3.This is the first deterministic algorithm for the problem with a constant competitive ratio.When p(J)∈{1,k},k>1 is a real number,we first present a lower bound minf(1+k)/k,2k/(1+k)g,and then we show that LEJ has a competitive ratio of 1+┌k┐=k.In particular,when all the k length jobs have tight deadlines,we first present a lower bound max{4=(2+k),1}(for ∑p(J)E(J))and 4/3(for ∑E(J)).Then we prove that LEJ is┌k┐/k-competitive for ∑p(J)E(J) and we provide an online algorithm H with a competitive ratio of 2┌k┐/(┌k┐+1)for the second objective function ∑E(J). 展开更多
关键词 SCHEDULING ONLINE algorithm KIND RELEASE time DEADLINE
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智能卡通讯中干扰测试的经验和诀窍 预览
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作者 杨利华 《中国集成电路》 2019年第6期67-70,共4页
智能卡的使用环境差异很大,有的电磁兼容环境很恶劣,既有来自电源的传导干扰,也有来自空间的辐射干扰。智能卡在通讯过程中受到干扰后,除了出现通讯中断、延时、死机等异常外,还存在指令跑飞、写地址变化、写数据变化等造成数据破坏的情... 智能卡的使用环境差异很大,有的电磁兼容环境很恶劣,既有来自电源的传导干扰,也有来自空间的辐射干扰。智能卡在通讯过程中受到干扰后,除了出现通讯中断、延时、死机等异常外,还存在指令跑飞、写地址变化、写数据变化等造成数据破坏的情形,因此,智能卡必须具备一定的抗干扰能力。评估智能卡的抗干扰能力一般通过固定时间内再现数据破坏的数量来确定。再现智能卡数据破坏不是很容易的事情,不是简单地对智能卡施加外来干扰,其中有一些经验和诀窍。本文介绍了一些智能卡通讯中干扰的经验和诀窍。 展开更多
关键词 通讯干扰 指令 释放
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一种可释放维生素B2的聚乙烯醇口腔膜的制备及其性能研究 预览
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作者 李俊起 李文明 +5 位作者 王宪鹏 史建华 朱爱臣 李博 郈秀菊 王传栋 《生物医学工程研究》 2019年第2期227-231,共5页
本研究将维生素B2溶解于聚乙烯醇(PVA)的水溶液中,利用静电纺丝法制备了含有维生素B2的PVA口腔膜,并测定其理化性能及溶出度。结果表明,该PVA膜具有合适的力学强度,遇水浸泡3h后的维生素B2含量累计释放度约为85.75%,可以作为贴膜来治疗... 本研究将维生素B2溶解于聚乙烯醇(PVA)的水溶液中,利用静电纺丝法制备了含有维生素B2的PVA口腔膜,并测定其理化性能及溶出度。结果表明,该PVA膜具有合适的力学强度,遇水浸泡3h后的维生素B2含量累计释放度约为85.75%,可以作为贴膜来治疗口腔溃疡。 展开更多
关键词 维生素B2 口腔溃疡 聚乙烯醇 电纺 释放
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Mathematical modeling of drug release from biodegradable polymeric microneedles 预览
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作者 Sarvenaz Chavoshi Mohammad Rabiee +6 位作者 Mehdi Rafizadeh Navid Rabiee Alireza Shahin Shamsabadi Mojtaba Bagherzadeh Reza Salarian Mohammadreza Tahriri Lobat Tayebi 《生物设计与制造(英文)》 CSCD 2019年第2期96-107,共12页
Transdermal drug delivery systems have overcome many limitations of other drug administration routes,such as injection pain and first-pass metabolism following oral route,although transdermal drug delivery systems are... Transdermal drug delivery systems have overcome many limitations of other drug administration routes,such as injection pain and first-pass metabolism following oral route,although transdermal drug delivery systems are limited to drugs with low molecular weight.Hence,new emerging technology allowing high molecular weight drug delivery across the skin—known as‘microneedles’—has been developed,which creates microchannels that facilitate drug delivery.In this report,drug-loaded degradable conic microneedles are modeled to characterize the degradation rate and drug release profile.Since a lot of data are available for polylactic acid-co-glycolic acid(PLGA)degradation in the literature,PLGA of various molecular weights-as a biodegradable polymer in the polyester family-is used for modeling and verification of the drug delivery in themicroneedles.The main reaction occurring during polyester degradation is hydrolysis of steric bonds,leading to molecular weight reduction.The acid produced in the degradation has a catalytic effect on the reaction.Changes in water,acid and steric bond concentrations over time and for different radii of microneedles are investigated.To solve the partial and ordinary differential equations simultaneously,finite difference and Runge–Kutta methods are employed,respectively,with the aid of MATLAB.Correlation of the polymer degradation rate with its molecular weight and molecular weight changes versus time are illustrated.Also,drug diffusivity is related to matrix molecular weight.The molecular weight reduction and accumulative drug release within the system are predicted.In order to validate and assess the proposed model,data series of the hydrolytic degradation of aspirin(180.16 Da)-and albumin(66,000 Da)-loaded PLGA(1:1 molar ratio)are used for comparison.The proposed model is in good agreement with experimental data from the literature.Considering diffusion as themain phenomena and autocatalytic effects in the reaction,the drug release profile is predicted.Based on our results for a 展开更多
关键词 MATHEMATICAL modeling MICRONEEDLE Polymer degradation DRUG release Poly(lactic-co-glycolic acid) AUTOCATALYTIC effect
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水华微囊藻衰亡后营养盐释放过程研究 预览
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作者 高磊 《安徽农学通报》 2019年第14期12-17,37共7页
在构建的水-沉积物系统中加入死亡的水华微囊藻细胞(烘箱中杀死),研究其衰亡后营养盐的释放过程及迁移转化规律。结果表明:(1)实验期间,微囊藻碎屑迅速分解释放,上覆水中DO和沉积物中氧化还原电位迅速降低;(2)实验初期上覆水中TN、NH4+-... 在构建的水-沉积物系统中加入死亡的水华微囊藻细胞(烘箱中杀死),研究其衰亡后营养盐的释放过程及迁移转化规律。结果表明:(1)实验期间,微囊藻碎屑迅速分解释放,上覆水中DO和沉积物中氧化还原电位迅速降低;(2)实验初期上覆水中TN、NH4+-N、NO3--N大幅上升,第4d达到最高水平,分别升高了16.6、13.3、6.4倍;第4d以后TN、NO3^--N逐渐降低,主要由于厌氧反硝化作用、向间隙水中迁移及NO3-向NH4+转化,NH4^+-N平稳缓慢增加,后期N主要以NH4^+的形式存在;(3)由于藻体分解,上覆水中TP、DTP、SRP、DOP的增加较快,第1d即达到较高水平,分别为初始值的4.10、5.29、4.86、8.33倍;(4)沉积物间隙水中TN、NH4+-N增幅较大,NO3--N次之,且NH4+-N持续升高,间隙水中N的形态也主要以NH4+的形式存在,整个实验阶段间隙水中TP、DTP、SRP一直有所升高,DOP先升高后降低;(5)沉积物成为微囊藻衰亡阶段营养盐释放的“汇”。 展开更多
关键词 水华微囊藻 衰亡 营养盐 释放
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稻壳生物炭/醋酸酯淀粉-尿素复合膜的结构和性能
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作者 钟旋 简秀梅 +2 位作者 蒋恩臣 孙焱 王明峰 《复合材料学报》 EI CAS CSCD 北大核心 2019年第7期1746-1752,共7页
采用流延法制备了醋酸酯淀粉(AS)∶尿素(UR)∶稻壳生物炭(RHBC)质量比分别为8∶1∶1、8∶2∶1、8∶4∶1的RHBC/AS-UR复合膜,利用SEM、FTIR、XRD、TGA等测试手段对RHBC/AS-UR复合膜的微观形态和结构性能进行了研究,采用流化床喷雾包膜装... 采用流延法制备了醋酸酯淀粉(AS)∶尿素(UR)∶稻壳生物炭(RHBC)质量比分别为8∶1∶1、8∶2∶1、8∶4∶1的RHBC/AS-UR复合膜,利用SEM、FTIR、XRD、TGA等测试手段对RHBC/AS-UR复合膜的微观形态和结构性能进行了研究,采用流化床喷雾包膜装置制备了RHBC/AS-UR包膜UR肥并测试了其释放特性。结果表明:RHBC能够均匀的分散于RHBC/AS-UR复合膜中,与UR-AS交联体间形成了“固体桥”的微观结构,结合紧密,同时,RHBC的添加可以提高复合膜的热稳定性。UR的添加可以提高复合膜的延展性能,当UR质量分数为18.2wt%时,RHBC/AS-18.2wt%UR复合膜的力学性能达到最佳,断裂伸长率提高了约500%。UR释放特性试验结果表明,与未包膜UR相比,不同质量比的RHBC/AS-UR包膜UR均能有效降低UR态氮的释放速率,其中,RHBC/AS-18.2wt%UR包膜UR在连续24h浸泡后的总释放率最小(81%),表现出更好的缓慢释放性能。 展开更多
关键词 稻壳生物炭 尿素 醋酸酯淀粉 复合膜 性能 释放
青狮潭库区沉积物/稻田土壤中有机氯农药残留与释放规律 预览
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作者 梁延鹏 符鑫 +2 位作者 曾鸿鹄 覃礼堂 莫凌云 《农业环境科学学报》 CAS CSCD 北大核心 2019年第6期1330-1338,共9页
为了解青狮潭库区沉积物和土壤中有机氯农药(OCPs)残留及其释放特征,采用气相色谱法(GC-ECD)测定了青狮潭库区水库沉积物、池塘沉积物、河流沉积物和稻田土壤中OCPs含量,并运用室内模拟装置探讨了沉积物和稻田土壤在静置和悬浮两种情景... 为了解青狮潭库区沉积物和土壤中有机氯农药(OCPs)残留及其释放特征,采用气相色谱法(GC-ECD)测定了青狮潭库区水库沉积物、池塘沉积物、河流沉积物和稻田土壤中OCPs含量,并运用室内模拟装置探讨了沉积物和稻田土壤在静置和悬浮两种情景下OCPs的释放规律。结果表明:水库沉积物、池塘沉积物、河流沉积物和稻田土壤中总OCPs残留量分别为81.55、88.60、68.96 ng·g^-1和92.62 ng·g^-1(干质量)。HCHs和DDTs是两类残留量较高的OCPs,其含量分别达到23.26~39.89 ng·g^-1和12.22~17.20 ng·g^-1。上覆水为超纯水时,静置组与扰动组的底物中OCPs向上覆水释放表现出先快后慢的特征,且扰动组的底物中OCPs释放量明显多于静置组;其中HCHs和β-硫丹的释放量最高。OCPs的理化性质、底物组成特征和外力扰动使各种OCPs在上覆水中的检出率和检出浓度存在明显差异,其中稻田土壤中OCPs向上覆水释放量最高而河流沉积物中OCPs向上覆水释放量最低。十二烷基硫酸钠可使底物中的OCPs快速向上覆水中释放(尤其促进了DDTs的释放),在扰动和静置情形下,上覆水OCPs浓度最少可提升134.44%和118.41%。因此,外界扰动和十二烷基硫酸钠汇入均可促进底物中OCPs的溶出释放。 展开更多
关键词 有机氯农药 沉积物 稻田土壤 释放 青狮潭水库
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Strong dual-crosslinked hydrogels for ultrasound-triggered drug delivery
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作者 Wenxu Sun Heting Jiang +8 位作者 Xin Wu Zhengyu Xu Chen Yao Juan Wang Meng Qin Qing Jiang Wei Wang Dongquan Shi Yi Cao 《纳米研究:英文版》 SCIE EI CAS CSCD 2019年第1期115-119,共5页
Hydrogels that can respond to dynamic forces either from endogenous biological activities or from external mechanical stimuli show great promise as novel drug delivery systems (DDS).However,it remains challenging to e... Hydrogels that can respond to dynamic forces either from endogenous biological activities or from external mechanical stimuli show great promise as novel drug delivery systems (DDS).However,it remains challenging to engineer hydrogels that specifically respond to externally applied mechanical forces with minimal basel drug leakage under normal stressful physiological conditions.Here we present an ultrasound responsive hydrogel-based DDS with special dual-crosslinked nanoscale network architecture.The covalent crosslinks endow the hydrogel high mechanical stability and greatly suppress deformation-triggered drug release.Meanwhile,the dynamic covalent boronate ester linkages between hydrogel backbone and the anti-inflammation compound,tannic acid (TA),allow effective ultrasound-triggered pulsetile release of TA.As such,the hydrogel shows distinct drug release profiles under compression and ultrasound.A proof-of-principle demonstration of the suppression of inflammation activation of macrophage upon ultrasound-triggered release of TA was also illustrated.We anticipate that this novel hydrogel-based drug delivery system can be used for the treatment of inflammatory diseases on load-bearing tissues,such as muscle and cartilage. 展开更多
关键词 HYDROGEL dynamic COVALENT bond mechanical force drug release
Photodynamic therapy-triggered on-demand drug release from ROS-responsive core-cross-linked micelles toward synergistic anti-cancer treatment
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作者 Yongjuan Li Jian Hu +6 位作者 Xun Liu Yong Liu Shixian Lv Juanjuan Dang Yong Ji Jinlin He Lichen Yin 《纳米研究:英文版》 SCIE EI CAS CSCD 2019年第5期999-1008,共10页
Polymeric micelles have demonstrated wide utility for chemodrug delivery,which however,still suffer from shortcomings such as undesired drug loading,disassembly upon dilution,pre-leakage of drug cargoes during systemi... Polymeric micelles have demonstrated wide utility for chemodrug delivery,which however,still suffer from shortcomings such as undesired drug loading,disassembly upon dilution,pre-leakage of drug cargoes during systemic circulation,and lack of cancer-selective drug release.Herein,a poly(ethylene glycol)(PEG)-polyphosphoester-based,reactive oxygen species (ROS)-responsive,core-cross-linked (CCL) micellar system was developed to encapsulate both chemodrug (doxorubicin,Dox) and photosensitizer (chlorin e6,Ce6).The hydrophobic core of the micelles was cross-linked via a thioketal (TK)-containing linker,which notably enhanced the drug loading and micelle stability.In tumor cells,far-red light irradiation of Ce6 generated ROS to cleave the TK linkers and disrupt the micelle cores.As such,micelles were destabilized and Dox release was promoted,which thereafter imparted synergistic anti-cancer effect with ROS-mediated photodynamic therapy.This study provides an effective approach to realize the precise control over drug loading,formulation stability,and cancer-selective drug release using polymeric micelles,and would render promising utilities for the programmed anti-cancer combination therapy. 展开更多
关键词 core-cross-linked micelles ON-DEMAND drug release photodynamic THERAPY reactive oxygen species (ROS) RESPONSIVENESS SYNERGISTIC an ti-cancer THERAPY
Water incubation-induced fluctuating release of heavy metals in two smelter-contaminated soils
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作者 Bin Yang Yunzhe Cao +3 位作者 Jie Ren Mei Wang Huilong Luo Fasheng Li 《环境科学学报:英文版》 SCIE EI CAS CSCD 2019年第8期14-23,共10页
The soil moisture regime can affect the release of heavy metals in soil. In the previous studies, slightly polluted soils or artificially contaminated soil samples were considered to investigate the effect of soil moi... The soil moisture regime can affect the release of heavy metals in soil. In the previous studies, slightly polluted soils or artificially contaminated soil samples were considered to investigate the effect of soil moisture. We used highly smelter-contaminated and aged soils to study the release of typical heavy metals(Cu, Zn, Cd and Pb) induced by water incubation in batch experiments with characterization via speciation and X-ray diffraction analyses(XRD). The results show that the leachable concentrations of the heavy metals increased slightly in the first 30 days, decreased drastically between 30 and 90 days, and immobilized relatively constant thereafter. The fluctuation was ascribed to the changes of soil Eh and pH, the reductive dissolution of crystalline iron oxides, the formation of new amorphous iron oxides, the absorption of dissolved organic matter and the precipitation of metal sulfide. Speciation analysis indicated that a proportion of the soil heavy metals was transformed from an exchangeable fraction to a less labile fraction after water incubation. And the presence of a lead iron oxide phase and the peak increasing of zinc sulfide were observed via XRD analyses. Finally, water incubation restrained the release of heavy metals after 180 days of incubation, and reduced the leachability of Cu, Zn, Cd and Pb by as much as 1.61%–7.21% for soil A and 0.43%–3.36% for soil B, respectively. The study findings have implications for the formulation of risk control and management strategies for heavy metals in smelter-contaminated soils. 展开更多
关键词 Smelter-contaminated soil Heavy metals WATER INCUBATION RELEASE FRACTION
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