Development of superparamagnetic functional carriers and application for affinity separation of subtilisin Carlsberg

Superparamagnetic functional carriers to obtain high selectivity were reported in this study. Magnetic carriers with epoxy groups were synthesized by spraying suspension polymerization (SSP). The measurement of scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM) showed that the magnetic carriers have a narrow size distribution and displayed superparamagnetic characteristics. The magnetic carriers with epoxy groups were modified by various affinity ligands to magnetic functional carriers such as copper-IDA carriers, benzamidine carriers and phenylboronic acid carriers. The effects of medium pH and subtilisin Carlsberg concentration on adsorption capacity were investigated. It was found that phenylboronic acid and benzamidine immobilized magnetic carriers were effective magnetic carriers for affinity adsorption of subtilisin Carlsberg, and the maximum adsorption capacity (about 65 mg/g) was obtained at pH 9.5. The adsorbed subtilisin Carlsberg was also desorbed successfully by using dissociation agents, and the recovery of the enzyme activity was still around 85%.     

载体对肉桂醛选择性加氢钴基催化剂的影响

以肉桂醛选择性加氢制肉桂醇为探针反应,通过反应筛选出对催化作用有利的载体,并确定催化剂的最佳负载量。催化剂表征结果表明,酸性载体较碱性载体好,在酸性载体中硅藻土具有更好的助催化作用,钴负载在硅藻土上的最佳负载质量分数为12%,载体存在颗粒效应及催化剂金属与载体存在强相互作用,载体影响催化剂的分布、晶体的形状及活性中心的多少。     

化学链燃烧中载氧体的研究进展

介绍了化学链燃烧的工艺原理和特点,总结载氧体的选材要求及性能,通过分析镍系、铁系、锰系、铜系和新型载氧体的性能,对以后载氧体的发展方向进行了展望。     

CuO修饰Fe基载氧体的锡盟褐煤化学链燃烧特性分析

为提高Fe基载氧体性能以及研究锡盟褐煤化学链燃烧特性,以硝酸盐试剂及CuO粉末为原料,通过共沉淀法制备了不同质量分数CuO修饰的Fe基载氧体且使用固定床制备褐煤焦样,对制得的载氧体进行表征分析,并在小型流化床反应器中进行了褐煤及其煤焦的化学链燃烧实验。结果表明:实验制得的载氧体完成了良好的结晶过程,且经CuO修饰后的载氧体中出现了CuFe₂O₄;在褐煤化学链燃烧实验中,相比于不经CuO修饰的Fe基载氧体,修饰后的载氧体具有更好的反应活性,具体表现在碳转化率方面,通过对不同质量分数CuO修饰的Fe基载氧体进行实验分析,10%CuO修饰的载氧体褐煤化学链燃烧中碳转化率为94.84%,较不修饰情况下的89.49%提升明显,同时碳转化速率峰值为23.81mol·%·min^-1,在相同时间内较不修饰情况提升4.21mol·%·min^-1,使用10%CuO修饰的载氧体进行褐煤焦化学链燃烧实验时碳转化率高达95.80%;循环实验中,15次化学链燃烧实验循环后,褐煤化学链燃烧碳转化率为88.69%,对反应后的载氧体表征分析表明,10%CuO修饰的Fe基载氧体仍保持了较为稳定的性能。     

Combined PCSK9 and APOE Polymorphisms are Genetic Risk Factors Associated with Elevated Plasma Lipid Levels in a Thai Population

Proprotein convertase subtilisin/kexin type 9 (PCSK9) and apolipoprotein E (ApoE) play a key role in the regulation of lipid metabolism. We aimed to investigate the effects of PCSK9 (R46L, I474V, and E670G) and APOE polymorphisms on lipid levels in a Southern Thai population. A total of 495 participants (307 urban, 188 rural) were recruited for the study. Anthropometric and biochemical variables were evaluated. PCSK9 and APOE polymorphisms were analyzed using PCR–RFLP. The 46L urban male carriers had significantly higher diastolic blood pressure (DBP) and fasting blood sugar compared with non‐carriers. In contrast, the 46L urban female carriers had significantly lower total cholesterol (TC) and LDL‐C levels compared with non‐carriers. The 474V rural female carriers had significantly lower HDL‐C levels than non‐carriers. The 670G urban female carriers showed significantly higher TC and LDL‐C levels compared with non‐carriers. APOE4 carriers had increased TC and LDL‐C levels relative to APOE3 carriers in the urban males. APOE2 carriers had decreased TC and/or LDL‐C levels compared with APOE3 carriers in urban males and females. A significant trend of increased TC and LDL‐C levels was observed in non‐APOE4‐PCSK9 670EE carriers to APOE4‐PCSK9 670EG carriers in urban subjects. In summary, R46L, I474V, and E670G may be genetic risk factors for cardiovascular disease (CVD) in urban males, rural females, and urban females, respectively. In contrast, R46L had a favorable lipid profiles that may protect against CVD in urban females. The combination of PCSK9 E670G and APOE polymorphisms may represent an independent factor for the determination of lipid levels.     

化学链燃烧中载氧体磨损和产生积碳的机制及抑制方法

磨损和积碳的产生都严重干扰化学链燃烧(CLC)的正常运行，磨损可造成载氧体的损耗，积碳可导致载氧体与燃料不能充分接触。载氧体的循环燃烧效率与CLC技术成本密切相关，是其进入商业化的关键。本工作针对载氧体的磨损和积碳抑制这两大主要问题进行了分析总结。阐述了CLC过程发生的详细反应及形成炭黑型积碳前驱物多环芳烃机制，总结了应对的可行方法，其中联合水蒸气和CO2喷射具有很好的前景。并在此基础上讨论了该领域的潜在研究需求。     

高分子药物载体的应用及研究趋势

高分子材料越来越多的被应用于化工医药领域作为药物的载体,这一技术愈来愈受到研究者们的重视,并且得到了较好的发展。介绍了近年来研究比较广泛的高分子药物载体的应用情况及研究态势,展望了生物活性药物载体的应用前景。     

Numerical modeling of adhesive particle mixing

The discrete element method is used to investigate adhesive particle mixing in a system that includes large carrier particles and fine particle agglomerates in a Couette mixer. The simulation starts with 200 carriers and 10 agglomerates with 1000 fine particles each. During mixing, the agglomerates are broken, fractions adhere to the carriers, and there is continuous redistribution of fines between carriers. The focus is to obtain information on the quantity and quality of fine particles adhered to carriers by postprocessing the simulation data. Variation in the structure of agglomerates due to shearing is studied over mixing time. Findings indicate that major fraction of fine particles are dispersed evenly onto the surface of carriers and the rest are in form of free debris. A time‐dependent index is introduced to predict the degree of mixing. Finally, the adhesion force between carriers and coated layers is observed to have a peak at 1 nN. © 2017 American Institute of Chemical Engineers AIChE J, 63: 2599–2609, 2017     

杨木MWL和LCC制备多孔生物载体及其在人体肝细胞培养中的应用

为了比较磨木木质素（MWL）与木质素-碳水化合物复合体（LCC）与人体肝细胞的生物相容性,从杨木中提取MWL和LCC,制备水凝胶,冷冻干燥形成多孔生物载体。利用红外光谱和扫描电子显微镜对多孔生物载体的成分及表面形态进行了分析,采用多孔生物载体对人肝细胞进行体外培养,并对肝细胞形态及代谢活性进行检测。结果表明：LCC基载体中木质素含量较低而碳水化合物含量较高,因此其两亲性较MWL基载体好。以MWL和LCC制备的多孔生物载体,孔隙率达到60%左右,平均孔径约为30 μm。细胞形态、白蛋白分泌和葡萄糖代谢的分析结果显示,相比MWL基载体,LCC基多孔生物载体能更好地促进肝细胞长期生长,具有更好的生物相容性。     

非均相茂金属催化剂载体的研究进展

文章介绍了茂金属催化剂载体的研究新进展,着重介绍了无机载体和有机载体用于茂金属催化剂负载化的研究现状。分别陈述了无机和有机载体的一些常见载体类型,例如硅胶载体和聚苯乙烯载体;并对比了无机载体和有机载体的颗粒形态,强度,表面基团等物理化学性质的差异。研究表明,载体材料本身结构及其物理化学性质对聚合活性,聚合物形态和堆积密度有着直接的作用。进一步探索载体的结构性能与聚合动力学的关系,将对对进一步提高聚合活性,改善聚合物颗粒形态具有深远的意义。     

Ultrafast Carrier Relaxation in InN Nanowires Grown by Reactive Vapor Transport

We have studied femtosecond carrier dynamics in InN nanowires grown by reactive vapor transport. Transient differential absorption measurements have been employed to investigate the relaxation dynamics of photogenerated carriers near and above the optical absorption edge of InN NWs where an interplay of state filling, photoinduced absorption, and band-gap renormalization have been observed. The interface between states filled by free carriers intrinsic to the InN NWs and empty states has been determined to be at 1.35 eV using CW optical transmission measurements. Transient absorption measurements determined the absorption edge at higher energy due to the additional injected photogenerated carriers following femtosecond pulse excitation. The non-degenerate white light pump-probe measurements revealed that relaxation of the photogenerated carriers occurs on a single picosecond timescale which appears to be carrier density dependent. This fast relaxation is attributed to the capture of the photogenerated carriers by defect/surface related states. Furthermore, intensity dependent measurements revealed fast energy transfer from the hot photogenerated carriers to the lattice with the onset of increased temperature occurring at approximately 2 ps after pulse excitation.     

Pulverisierung hochviskoser Flüssigkeiten

Different processes for pulverizing malt extract are compared in view of quality and hygroscopicity. Three different processes with and without carriers are verified and it is demonstrated that processes without carriers (spray‐drying) yield very hygroscopic powders. Processes with carriers, i.e., flour, using fluidised bed agglomeration are proved to be reasonable.     

用于酶固定化的高分子载体材料研究进展

固定化酶是一种高效、高选择性和反应条件温和的生物催化剂。近年来,高分子材料作为酶固定化载体的研究越来越受到重视,相关的研究报道很多。对近十多年来用于固定化酶的高分子载体材料以及它们的优缺点进行了综述,并对用于酶固定化高分子载体材料的发展前景作了展望。     

载体对甲维盐固体纳米制剂的性能影响

为了研究载体对农药固体纳米制剂理化性能的影响及其选择原则，采用自乳化-载体固化法制备了7种不同载体的甲氨基阿维菌素苯甲酸盐（甲维盐）固体纳米分散体。比较了载体粉末粒度、溶解度、比表面积及形貌间的差异性，揭示了不同载体对甲维盐固体纳米分散体粒径、分散度、界面电荷、pH、晶型及叶面润湿性的影响。结果表明，农药固体纳米分散体中载体的理化性质及结构对纳米制剂的粒度、分散性、界面性质及晶型具有显著影响。苯甲酸钠为甲维盐固体纳米分散体的优良载体，载药粒子的平均粒径为22 nm，PDI为0.358。     

煤化学链燃烧载氧体研究进展

煤的化学链燃烧是清洁煤燃烧的重要技术之一。化学链中载氧体的使用可以避免煤和空气直接接触,从而避免氮氧化物等污染物的产生并提高能量转化效率。一般来说,煤的化学链燃烧有2种反应途径:煤气化化学链燃烧和氧解耦化学链燃烧;不同反应途径将极大影响载氧体组分以及结构设计。详细论述了2015-2020年煤化学链燃烧中固态金属载氧体的研究进展,包括铁基、锰基、铜基、镍基、硫酸钙以及其他复合金属载氧体。总结了不同金属载氧体的优缺点、反应路径、气-固和固-固反应机理、金属与载体的相互作用以及载氧体失活原理。铁基载氧体被广泛应用于气化化学链燃烧中,但单一铁基载氧体的反应速率较低。适量添加碱金属或碱土金属可以提升载氧体的反应活性。锰基载氧体在化学链燃烧中具有两面性:一方面可以在高温缺氧气氛中释放气态氧,另一方面也可以与还原性气体发生气-固反应。通过使用惰性载体以及碱金属添加剂可以提高锰基载氧体的机械强度和氧解耦能力。含铜载氧体具有出色的氧解耦能力和反应活性而被广泛关注,然而铜及其氧化物低熔点所带来的金属聚集导致载氧体的失活问题亟需克服。研究发现使用铁、锰和铜矿石制得的载氧体具有良好的反应性能。硫酸钙载氧体具有较好的反应活性,但煤的化学链燃烧时潜在的二氧化硫和硫化氢副产物需要引起重视。镍基载氧体虽然在煤的化学链燃烧中反应性能较好,但硫毒化、成本较高和环保性能不佳等缺点导致近年来镍基载氧体的研究较少。新型双金属或多金属载氧体可以同时结合2种金属的反应特性,从而显著提高载氧体的整体反应活性。基于载氧体的研究现状,对未来的发展方向提出了4点建议:结合2种煤的化学链燃烧机理设计新型氧解耦辅助化学链燃烧载氧体;发展新型材料和金属组分的载氧体;利用冶金工业废料制得载氧体;开发新型结构的载氧体。     

基于壳聚糖的缓释材料应用研究进展

药物缓释材料种类繁多,壳聚糖因其自身多方面的特性而成为理想的药物缓释载体。文章简要介绍了壳聚糖的缓释机理,且因壳聚糖本身拥有的特殊药理作用,它可用于抗炎、抗癌、抗肺结核及基因类药物载体,模型实验显示均收到了较好的药物缓释效果和相应的治疗效果,因此,本文主要介绍了壳聚糖作为不同药物缓释载体的应用研究进展。     

Low‐temperature carrier dyeing of poly(vinyl chloride) fibers with disperse dyes

The effects of various carriers on the color yield of poly(vinyl chloride) (PVC) filaments in a disperse dyeing system were investigated. The dyeability of disperse dyes on PVC fiber was improved using appropriate carriers. The enhancement of dye uptake imparted by carriers coincided with the reduction in glass‐transition temperature, which in turn coincided approximately with the similarity of the inorganic/organic ratio values between PVC fibers and carriers. The results clearly demonstrate that hydrophobic carriers function as diluents of PVC fiber, facilitating dye diffusion by increasing segmental mobility of the fiber. The dyed PVC filaments with disperse dyes showed reasonable levels of build‐up and color fastness properties in the carrier‐assisted dyeing. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3896–3904, 2003     

Open-cell polyvinylidene fluoride foams as carriers to promote biofilm growth for biological wastewater treatment

This article reports the design and fabrication of open-cell polyvinylidene fluoride (PVDF) foams as carriers that can promote biofilm growth and organic removal efficiency for biological wastewater treatment in attached growth bioreactors. Open-cell PVDF foams were fabricated by a manufacturing approach that integrated compression molding and particulate leaching. PVDF carriers were structured with two governing factors of leaching agent types (e.g., sodium chloride [NaCl] and sodium acetate [NaOAc]) and contents (e.g., 80 and 90 wt%). Open-cell PVDF foams possessed high porosity and high protected surface area (i.e., more than ×10 to ×20 of the areas of commercialized carriers), which promoted biofilm growth in these carriers. As a successful advantage, PVDF carriers used in the moving bed biofilm reactors (MBBR) were entirely covered by biofilm in both interior and exterior parts without clogging. This provides strong evidence of the bacterial compatibility of the fabricated open-cell PVDF foam carriers. Moreover, the specific morphology of the PVDF carriers in this article provided superior biofilm protection from the detachment in MBBR. Experimental results revealed that PVDF open-cell foams fabricated by 80 wt% of NaCl demonstrated higher mechanical strength with an organic removal efficiency of 77% ± 7% in the corresponding bioreactor containing them.     

氨基功能载体固定化酶研究进展

综述了甲壳素、壳聚糖天然氨基功能载体和氨基化硅胶化学合成载体的制备方法,并介绍了利用戊二醛直接固定、载体活化和酶活化固定化酶的方法,最后对氨基功能载体固定化酶的发展趋势加以评述:在利用氨基功能载体固定化酶过程中,有必要有针对性地合成一些新的氨基功能载体,使其反应条件更温和、酶的固载量更大、酶活力回收率更高、稳定性更强。或者针对特定的载体和酶,通过结合配体、添加稳定剂、固定前修饰、固定后修饰和后固定化技术处理等方法,进一步改善固定化酶的性能。     

典型内循环生物流化床的水力及充氧特性研究

以挂膜后的活性碳为载体，在不同投加率下研究了典型内循环生物流化床的水力特性及充氧特性。实验结果表明，流体循环时间及混合时间均随气速及栽体投加量增加而缩短；循环时间随液速增大而缓慢减小；混合时间随液速变化规律较复杂；各区气相含率随气速及载体含率的增大而升高；且受气速影响显著；KLa随气速、栽体投加率增加总趋势为增大，但幅度较小。