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通过蛋白质工程提高聚酯水解酶对PET 塑料的降解效率 Article

马渊, 姚明东, 李炳志, 丁明珠, 何博, 陈思, 周晓, 元英进

《工程(英文)》 2018年 第4卷 第6期   页码 888-893 doi: 10.1016/j.eng.2018.09.007

摘要:

来自Ideonella sakaiensis 的聚对苯二甲酸乙二醇酯水解酶(PETase)在室温下具有很强的降解聚对苯二甲酸乙二醇酯(PET)的能力,因此被认为是解决聚酯塑料污染问题的潜在工具在本研究中,基于PETase 和底物2PET 结合时的相互作用模型,分析了PETase 与底物2PET 之间的相互作用,从而对底物结合沟壑周围的六个关键残基进行改造。其中,I179F突变体的酶活性最高,降解效率为22.5 mg·μmol–1·d–1。因此,本研究通过蛋白质工程对PETase 的关键疏水位点进行设计和改造,获得了降解效果提高的酶突变体,并进一步证实了其生物降解塑料的潜力。

关键词: 聚酯酶     PET降解     无细胞蛋白质合成     聚酯     PET   

局部高空间分辨率的应用适应性PET系统设计初探

刘晶晶,谢庆国

《中国工程科学》 2011年 第13卷 第10期   页码 105-112

摘要:

研制成本可负担的高空间分辨率正电子发射断层成像(positron emission tomography,PET)系统在PET成像应用中具有决定性的意义,也是PET成像面临的关键性挑战之一。设想一种PET系统,能够根据应用的需求对不同性能的探测器进行布局,在一个具体时刻,对部分成像区域获得很高的性能,而在其他的区域获得普通性能。提出了一种应用适应性PET系统原型,由大部分普通固有空间分辨率的探测模块和少量更高甚至极端高固有空间分辨率的探测模块组成。研究了在含有连续放置的一段高固有空间分辨率探测模块的PET系统中,高性能模块的布局位置和数量对视场内不同位置点的空间分辨率的影响。

关键词: 正电子发射断层成像     应用适应性PET系统     感兴趣区域     局部空间分辨率     不同性能探测模块    

F-FDG-PET glucose hypometabolism pattern in patients with epileptogenic hypothalamic hamartoma

《医学前沿(英文)》 2021年 第15卷 第6期   页码 913-921 doi: 10.1007/s11684-021-0874-1

摘要: Epileptogenic hypothalamic hamartoma is characterized by intractable gelastic seizures. A systematic analysis of the overall brain metabolic pattern in patients with hypothalamic hamartoma (HH) could facilitate the understanding of the epileptic brain network and the associated brain damage effects of HH. In this study, we retrospectively evaluated 27 patients with epileptogenic HH (8 female patients; age, 2–33 years) by using 18F-fluorodeoxyglucose-positron emission tomography. The correlations among tomography result, seizure type, sex, and structural magnetic resonance imaging were assessed. Whole metabolic patterns and voxel-based morphometry findings were assessed by group analysis with healthy controls. Assessment of the whole metabolic pattern in patients with HH revealed several regional metabolic reductions in the cerebrum and an overall metabolic reduction in the cerebellum. In addition, areas showing hypometabolism in the neocortex were more widely distributed ipsilaterally than contralaterally to the HH. Reductions in glucose metabolism and gray matter volume in the neocortex were predominant ipsilateral to the HH. In conclusion, the glucose hypometabolism pattern in patients with epileptogenic HH involved the neocortex, subcortical regions, and cerebellum. The characteristics of glucose hypometabolism differed across seizure type and sex. Reductions in glucose metabolism and structural changes may be based on different mechanisms, but both are likely to occur ipsilateral to the HH in the neocortex. We hypothesized that the dentato-rubro-thalamic tract and cerebro-ponto-cerebellar tract, which are responsible for intercommunication between the cerebral cortex, subcortical regions, and cerebellar regions, may be involved in a pathway related to seizure propagation, particularly gelastic seizures, in patients with HH.

关键词: hypothalamic hamartoma     gelastic seizure     fluorodeoxyglucose-positron emission tomography     voxel-based morphometry    

4-Amino-1,8-naphthalimide based fluorescent photoinduced electron transfer (PET) pH sensors as liposomalcellular imaging agents: The effect of substituent patterns on PET directional quenching

Miguel Martínez-Calvo, Sandra A. Bright, Emma B. Veale, Adam F. Henwood, D. Clive Williams, Thorfinnur Gunnlaugsson

《化学科学与工程前沿(英文)》 2020年 第14卷 第1期   页码 61-75 doi: 10.1007/s11705-019-1862-8

摘要: Four new fluorescent sensors ( - ) based on the 4-amino-1,8-naphthalimide fluorophores ( ) have been synthesized based on the classical fluorophore-spacer-receptor model. These four compounds all gave rise to emission bands centred at 535 nm, which were found to be highly pH dependent, the emission being ‘switched on’ in acidic media, while being quenched due to PET from the amino moieties to the excited state of the at more alkaline pH. The luminescent pH dependence for these probes was found to be highly dependent on the substitution on the imide site, as well as the polyamine chain attached to the position 4-amino moiety. In the case of sensor the presence of the 4-amino-aniline dominated the pH dependent quenching. Nevertheless, at higher pH, PET quenching was also found to occur from the polyamine site. Hence, is better described as a receptor -spacer -fluorophore-spacer -receptor system, where the dominant PET process is due to (normally less favourable) ‘directional’ PET quenching from the 4-amino-aniline unit to the site. Similar trends and pH fluorescence dependences were also seen for and . These compounds were also tested for their imaging potential and toxicity against HeLa cells (using DRAQ5 as nuclear stain which does now show pH dependent changes in acidic and neutral pH) and the results demonstrated that these compounds have reduced cellular viability at moderately high concentrations (with IC values between ca. 8‒30 µmol∙L ), but were found to be suitable for intracellular pH determination at 1 µmol∙L concentrations, where no real toxicity was observed. This allowed us to employ these as lysosomal probes at sub-toxic concentrations, where the based emission was found to be pH depended, mirroring that seen in aqueous solution for , with the main fluorescence changes occurring within acidic to neutral pH.

关键词: sensors     pH     photoinduced electron transfer     cellular imaging     confocal microscopy    

Solubility of CO in solid-state PET measured by pressure-decay method

CHEN Miaocan, ZHAO Ling, LIU Tao, WU Jiangwei, YUAN Weikang

《化学科学与工程前沿(英文)》 2008年 第2卷 第2期   页码 214-219 doi: 10.1007/s11705-008-0040-1

摘要: The solubility of CO in solid-state PET was measured using a pressure-decay method. In order to calculate the solubility of CO in the amorphous region of PET, the crystallinity of solid state PET dissolved in CO at different pressures and temperatures was measured by differential scanning calorimetry (DSC). The solubility increases with increasing pressure and it follows a linear relationship and obeys Henry’s law when the pressure is below 8 MPa. The effect of temperature on solubility is weak and the solubilities at different temperatures are almost the same under low pressures. At higher pressure, the solubility decreases with an increase in temperature. The solubility of CO in the amorphous region of PET at 373.15 K, 398.15 K and 423.15 K was correlated with the Sanchez-Lacombe equation of state with a maximal correlation error of 6.69%.

关键词: Sanchez-Lacombe equation     solid-state PET     different     relationship     calorimetry    

Laser sintering of Cu nanoparticles on PET polymer substrate for printed electronics at different wavelengths

Juan Carlos HERNANDEZ-CASTANEDA, Boon Keng LOK, Hongyu ZHENG

《机械工程前沿(英文)》 2020年 第15卷 第2期   页码 303-318 doi: 10.1007/s11465-019-0562-x

摘要: This study explores the feasibility of different laser systems to sinter screen-printed lines from nonconductive copper nanoparticles (Cu NPs) on polyethylene terephthalate polymer film. These materials are commonly used in manufacturing functional printed electronics for large-area applications. Here, optical and thermal characterization of the materials is conducted to identify suitable laser sources and process conditions. Direct diode (808 nm), Nd:YAG (1064 nm and second harmonic of 532 nm), and ytterbium fiber (1070 nm) lasers are explored. Optimal parameters for sintering the Cu NPs are identified for each laser system, which targets low resistivity and high processing speed. Finally, the quality of the sintered tracks is quantified, and the laser sintering mechanisms observed under different wavelengths are analyzed. Practical considerations are discussed to improve the laser sintering process of Cu NPs.

关键词: laser sintering     copper nanoparticles     printed electronics    

土壤中石油污染物微生物降解及其降解去向

齐永强,王红旗,刘敬奇

《中国工程科学》 2003年 第5卷 第8期   页码 70-75

摘要:

通过多因素对比预实验,将筛选出的7个石油烃降解的主要影响因素以正交表方法组合起来,对其进行了实验研究。探讨了石油迁移转化对于各种土壤物理化学条件及其他环境因素改变的敏感程度,并找出了各主要影响因素的重要性和最佳水平;测定了土壤中所存在的石油污染物在生物降解作用下的后期产物,研究了不同条件下的样品残留污染物组分之间的差异影响土壤中石油烃类降解的主要因素有土壤石油污染强度、营养物(NH4NO3、K2HPO4)、氧化剂(3%H2O2溶液)、表面活性剂(TW80)、温度、土壤含水率和土壤透气性;在降解的不同阶段,各个因素的重要性以及最佳水平会发生相应的变化;在生物降解后期,土壤中残留的石油污染物主要是正构和异构烷烃

关键词: 土壤     石油污染物     微生物降解    

Erratum to: On secondary new particle formation in China

Markku KULMAMA,Tuukka Petäjä,Veli-Matti KERMINEN,Joni KUJANSUU,Taina RUUSKANEN,Aijun DING,Wei NIE,Min

《环境科学与工程前沿(英文)》 2016年 第10卷 第5期 doi: 10.1007/s11783-016-0857-7

Philadelphia chromosome-positive acute myeloid leukemia with masses and osteolytic lesions: finding of 18F-FDG PET

null

《医学前沿(英文)》 2017年 第11卷 第3期   页码 440-444 doi: 10.1007/s11684-017-0523-x

摘要:

Philadelphia chromosome-positive acute myeloid leukemia is controversial and difficult to distinguish from the blast phase of chronic myeloid leukemia. As a myeloid neoplasm, rare cases of this leukemia manifest multiple soft-tissue tumors or bone lytic lesions. In this paper, we describe a 49-year-old male patient who had an abrupt onset with sharp chest pain, fever, fatigue, emaciation, and splenomegaly. 18F-fluoro-deoxy-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) result showed diffuse and uneven hypermetabolic lesions in the bone marrow with peripheral bone marrow expansion, multiple soft tissue neoplasms with high 18F-FDG uptake, and lytic bone lesions. Bone marrow smear and biopsy detected aberrant blast cells expressing myeloid rather than lymphoid immunophenotype marker. For the existence of Philadelphia chromosome and BCR-ABL1 fusion gene together with complex chromosome abnormalities, a diagnosis of Philadelphia-positive acute myeloid leukemia was made, although the type (de novo or blast crisis) remained unclear.

关键词: Philadelphia chromosome     acute myeloid leukemia     mass     osteolysis     positron emission tomography    

容易断裂的可降解塑料 Letter

杨栩旭, Jason Steck, 杨加伟, 王叶成, 锁志刚

《工程(英文)》 2021年 第7卷 第5期   页码 624-629 doi: 10.1016/j.eng.2021.02.009

摘要:

降解塑料可以在特定环境中发生降解反应。上述降解反应动态过程的表征,往往通过测量塑料的质量和力学强度随时间的变化来实现。然而在塑料受到非均质降解的情况下,以上表征方法所得到的结果具有不准确性。本文研究了一种非均质的降解过程:可降解塑料在化学和外力的共同作用下,其中的裂纹发生扩展。在外力作用下,裂纹被打开,裂纹尖端暴露于化学侵蚀作用下,使其扩展速率超过整体均质降解速率。本文以聚乳酸(PLA)降解中的裂纹扩展为研究对象。PLA是一种聚酯类塑料,包含可被水解的酯键。这些发现将有助于可降解塑料的发展,并在医疗行业和环境可持续性发展方面具有重要意义。

关键词: 降解塑料     水解反应     pH值     裂纹扩展    

典型硼化合物对毛竹热降解与燃烧性能的影响

杨守禄,吴义强,卿彦,姚春花

《中国工程科学》 2014年 第16卷 第4期   页码 51-55

摘要:

利用热重和锥形量热仪研究硼酸、硼砂两种典型硼化合物对毛竹热降解和燃烧性能的影响。

关键词: 硼酸     硼砂     毛竹     降解     燃烧性能    

生物基全降解复合材料

刘小刚,王莉,李十中,樊琛语

《中国工程科学》 2011年 第13卷 第2期   页码 90-95

摘要:

淀粉/聚乳酸复合具有相对较好的力学性能和生物降解性能,价格也与石油基塑料最为接近,是极具应用前景的全生物降解塑性材料。

关键词: 研究进展     生物基材料     降解     淀粉     聚乳酸    

生物可降解材料与组织工程神经

顾晓松

《工程(英文)》 2021年 第7卷 第12期   页码 1700-1703 doi: 10.1016/j.eng.2021.10.011

PET imaging on neurofunctional changes after optogenetic stimulation in a rat model of panic disorder

Xiao He, Chentao Jin, Mindi Ma, Rui Zhou, Shuang Wu, Haoying Huang, Yuting Li, Qiaozhen Chen, Mingrong Zhang, Hong Zhang, Mei Tian

《医学前沿(英文)》 2019年 第13卷 第5期   页码 602-609 doi: 10.1007/s11684-019-0704-x

摘要: Panic disorder (PD) is an acute paroxysmal anxiety disorder with poorly understood pathophysiology. The dorsal periaqueductal gray (dPAG) is involved in the genesis of PD. However, the downstream neurofunctional changes of the dPAG during panic attacks have yet to be evaluated . In this study, optogenetic stimulation to the dPAG was performed to induce panic-like behaviors, and positron emission tomography (PET) imaging with F-flurodeoxyglucose ( F-FDG) was conducted to evaluate neurofunctional changes before and after the optogenetic stimulation. Compared with the baseline, post-optogenetic stimulation PET imaging demonstrated that the glucose metabolism significantly increased ( <0.001) in dPAG, the cuneiform nucleus, the cerebellar lobule, the cingulate cortex, the alveus of the hippocampus, the primary visual cortex, the septohypothalamic nucleus, and the retrosplenial granular cortex but significantly decreased ( <0.001) in the basal ganglia, the frontal cortex, the forceps minor corpus callosum, the primary somatosensory cortex, the primary motor cortex, the secondary visual cortex, and the dorsal lateral geniculate nucleus. Taken together, these data indicated that PET imaging can successfully detect downstream neurofunctional changes involved in the panic attacks after optogenetic stimulation to the dPAG.

关键词: panic disorder (PD)     positron emission tomography (PET)     optogenetics     dorsal periaqueductal gray (dPAG)    

Influence of recycled polyethylene terephthalate fibres on plastic shrinkage and mechanical properties of concrete

Necat ÖZAŞIK; Özgür EREN

《结构与土木工程前沿(英文)》 2022年 第16卷 第6期   页码 792-802 doi: 10.1007/s11709-022-0849-6

摘要: Polyethylene terephthalate bottles production has drastically increased year after year due to high versatility of polyethylene terephthalate plastics and considerable consumption of beverages. In tandem with that increase, the major concern of society has been the improper disposal of this non-biodegradable material to the environment. To deal with this concern, recycled polyethylene terephthalate bottles were incorporated in concrete as fibre reinforcements in this study. The objective of this research is to evaluate the mechanical properties of recycled polyethylene terephthalate fibre reinforced concrete (RPFRC) in comparison with control concrete without fibres. polyethylene terephthalate fibres with three different diameters (0.45, 0.65, and 1.0 mm) and two lengths (20 and 30 mm) were added at various proportions (0.5%, 1.0%, 1.5% and 2.0%) by volume of concrete in order to determine the effect of fibres initially on compressive, flexural and splitting tensile strengths of concrete. The results revealed that none of the fibres have detrimental effects up to 1% volume fraction, however further addition caused slight reductions on mechanical properties in some conditions. Plastic shrinkage resistance and impact resistance tests were also performed according to related standards. Polyethylene terephthalate fibres were observed to have marked improvements on those properties. Such a good performance could be attributed primarily to the bridging effect of fibres.

关键词: recycled PET     fibre-reinforced concrete     mechanical properties     plastic shrinkage     impact energy    

标题 作者 时间 类型 操作

通过蛋白质工程提高聚酯水解酶对PET 塑料的降解效率

马渊, 姚明东, 李炳志, 丁明珠, 何博, 陈思, 周晓, 元英进

期刊论文

局部高空间分辨率的应用适应性PET系统设计初探

刘晶晶,谢庆国

期刊论文

F-FDG-PET glucose hypometabolism pattern in patients with epileptogenic hypothalamic hamartoma

期刊论文

4-Amino-1,8-naphthalimide based fluorescent photoinduced electron transfer (PET) pH sensors as liposomalcellular imaging agents: The effect of substituent patterns on PET directional quenching

Miguel Martínez-Calvo, Sandra A. Bright, Emma B. Veale, Adam F. Henwood, D. Clive Williams, Thorfinnur Gunnlaugsson

期刊论文

Solubility of CO in solid-state PET measured by pressure-decay method

CHEN Miaocan, ZHAO Ling, LIU Tao, WU Jiangwei, YUAN Weikang

期刊论文

Laser sintering of Cu nanoparticles on PET polymer substrate for printed electronics at different wavelengths

Juan Carlos HERNANDEZ-CASTANEDA, Boon Keng LOK, Hongyu ZHENG

期刊论文

土壤中石油污染物微生物降解及其降解去向

齐永强,王红旗,刘敬奇

期刊论文

Erratum to: On secondary new particle formation in China

Markku KULMAMA,Tuukka Petäjä,Veli-Matti KERMINEN,Joni KUJANSUU,Taina RUUSKANEN,Aijun DING,Wei NIE,Min

期刊论文

Philadelphia chromosome-positive acute myeloid leukemia with masses and osteolytic lesions: finding of 18F-FDG PET

null

期刊论文

容易断裂的可降解塑料

杨栩旭, Jason Steck, 杨加伟, 王叶成, 锁志刚

期刊论文

典型硼化合物对毛竹热降解与燃烧性能的影响

杨守禄,吴义强,卿彦,姚春花

期刊论文

生物基全降解复合材料

刘小刚,王莉,李十中,樊琛语

期刊论文

生物可降解材料与组织工程神经

顾晓松

期刊论文

PET imaging on neurofunctional changes after optogenetic stimulation in a rat model of panic disorder

Xiao He, Chentao Jin, Mindi Ma, Rui Zhou, Shuang Wu, Haoying Huang, Yuting Li, Qiaozhen Chen, Mingrong Zhang, Hong Zhang, Mei Tian

期刊论文

Influence of recycled polyethylene terephthalate fibres on plastic shrinkage and mechanical properties of concrete

Necat ÖZAŞIK; Özgür EREN

期刊论文