微藻细胞的连续泡沫分离法采收

为考察连续泡沫分离法采收微藻细胞的可行性 ,在一种斜臂泡沫分离装置上 ,以螺旋藻为模型藻种 ,较为详细地研究了载气流率、藻液进料流率、浓度、pH值、离子强度、乙醇浓度、进料位置、泡沫段与液相段高度之比等因素对泡载采收性能的影响。结果表明 :在载气流率、藻液进料流率或藻液浓度较低时采收性能良好 ;当 pH值为 11、离子强度为 1 3× 10 ⁴ μs·cm^-1、乙醇浓度为 3%(体积 )时泡载收率可达 2 5 %～ 45 %;采用泡沫相段进料有利于提高泡载采收性能。提出的连续泡载采收动力学模型与实验值拟合较好 .     

盐藻细胞泡载分离法采收的初步研究

通过对盐藻细胞的浓缩倍数和采收率的测定，考察了藻液pH值、气体流速(vg)、藻细胞初始浓度(C0)对盐藻细胞的泡载分离采收性能的影响，优化了盐藻细胞泡载分离采收条件. 结果表明：在vg为60 ml/min，C0为2.58?105 个/ml，pH值为7.5的条件下，盐藻细胞泡载分离的采收率达90%~94%，浓缩倍数达30~34. 泡载分离是分离浓缩盐藻细胞的一种简便、高效的方法.     

内循环式泡沫浮选塔处理含铬废水

采用自制的内循环泡沫浮选塔处理含铬废水,考察pH值、Fe(NO3)3浓度、十二烷基硫酸钠(SDS)浓度、气体流量、分离时间等因素对分离效率的影响,并与常规泡沫塔比较. 结果表明,在12~35 min内,内循环式浮选塔分离效率更高,35 min时塔内铬离子浓度为0.6 mg/L,常规泡沫塔内铬离子浓度为10 mg/L. 内循环浮选塔最佳分离工艺条件为,对初始铬浓度为20 mg/L的废水,在pH 5.5、SDS 100 mg/L、Fe(NO3)3 60 mg/L、气体流量800 mL/min条件下处理效果最好,泡沫夹带率约为10%,Cr(III)脱除率可达97%以上.     

泡沫分离法提取乙醇水体系中甲基橙

采用泡沫分离法对含甲基橙的乙醇水溶液进行了提取研究. 考察了乙醇体积分数、气体流量、pH、甲基橙浓度和表面活性剂浓度对提取效果的影响,并对泡沫分离乙醇-水体系中提取中药有效成分的可行性进行了探讨. 结果表明,以十六烷基三甲基溴化铵(CTAB)为表面活性剂,在乙醇体积分数25%的乙醇-水体系中,在pH 6.0、气速80 mL/min、甲基橙浓度35 mg/L及CTAB浓度80 mg/L的操作条件下,甲基橙的富集比为14.38,回收率在98.5%以上. 在一定范围内提高表面活性剂浓度或加入稳泡剂以削弱乙醇的消泡作用,从而将泡沫分离技术应用于乙醇-水体系中中药有效成分的提取是可能的.     

十二烷基二甲基甜菜碱协助泡沫分离虎杖中白藜芦醇

为了开发简单高效的从虎杖中提取白藜芦醇的方法,促进白藜芦醇的产业化应用,本文采用水提和泡沫分离相结合的方法,在泡沫分离过程中选用十二烷基二甲基甜菜碱作为捕获剂,泡沫分离虎杖浸提液中白藜芦醇。研究了椭球型泡沫分离塔、pH、十二烷基二甲基甜菜碱浓度、气体体积流量对泡沫分离白藜芦醇分离效率的影响,并对分离前后白藜芦醇的抗氧化性进行了研究。结果表明,采用椭球型泡沫分离塔,在p H为3、十二烷基二甲基甜菜碱浓度1.50g/L以及气体体积流量20m L/min的条件下,白藜芦醇富集比和回收率分别为8.43和81.73%,消泡液中白藜芦醇浓度为0.085g/L,而且泡沫分离过程中能有效保持白藜芦醇的生物活性。     

泡沫分离除去水溶液中微量硫酸根离子

以十六烷基三甲基氢氧化铵为表面活性物质,采用泡沫分离技术对去除水溶液中微量硫酸根离子进行了研究,重点考察了溶液的pH、鼓泡气体流量、表面活性剂浓度及泡沫塔装液量的影响. 结果表明,十六烷基三甲基氢氧化铵具有良好的起泡性能,对水溶液中硫酸根离子的去除效果比较理想,在溶液pH 10、气体流量0.036 m3/h、装液量900 mL、表面活性剂浓度0.13 g/L的条件下,溶液中的SO42-能很好分离(富集比为22.4,去除率为94.1%). 与其他阳离子表面活性剂相比,十六烷基三甲基氢氧化铵在泡沫分离结束后不会在水溶液中引入新的酸根离子,为进一步探索脱盐新方法提供了依据.     

载银紫砂泡沫陶瓷的制备及抗菌性能

以聚氨酯泡沫为模板,采用浸渍工艺制备载银紫砂泡沫陶瓷.主要研究了AgNO3浓度、浸渍时间、pH值、热处理温度对载银紫砂泡沫陶瓷载银量的影响以及不同载银量样品的抗菌性能.实验结果表明,制备载银紫砂泡沫陶瓷最佳工艺条件为AgNO3浓度0.1mol/L、浸渍时间90 min、pH=10、热处理温度400℃.制备的载银紫砂泡沫陶瓷孔隙结构均匀,尺寸分布在0.3～0.7mm范围.银均匀分布于载银紫砂泡沫陶瓷中,使其具备良好的抗菌性能,且随着载银量增大,抗菌效果越明显.     

含十二烷基苯磺酸钠废水的多级泡沫分离研究

采用多级泡沫分离装置对水中十二烷基苯磺酸钠(SDBS)进行分离富集,考察了表面活性剂溶液的浓度、离子强度、pH值、分离时间、气体流速等因素对水中十二烷基苯磺酸钠脱除率的影响。进一步采用四因素三水平正交实验进行分离条件的优化,结果表明溶液浓度为20 mg/mL,气体流速为20L/min,pH=10,离子强度为2×10-5mol/L时,分离5 min,可使SDBS的脱除率最高达到97%,三次平行试验SDBS的脱除率分别为96.61%、97.04%和93.93%。与单级环流泡沫分离塔(其脱除率为82%)相比,多级泡沫分离装置具有能耗比低、分离效率高的优点,具有更好的推广应用价值。     

含铜和含锌稀溶液的吸附泡沫分离技术的研究

运用自制的泡沫分离塔,以十二烷基硫酸钠为表面活性剂对泡沫吸附分离含铜及含锌溶液的操作参数进行了研究。考察了料液浓度、pH值、气体流量、表面活性剂浓度等因素对含铜和含锌溶液泡沫分离效果的影响。结果表明：最佳操作参数为pH值5．0,料液浓度0．125mmol／L,进料流速50mL/min,气体流量100mL/min,表面活性剂浓度0．25mmol／L。同时从理论上推算出泡沫吸附分离铜离子的最佳pH值范围为5．0左右。实验还通过改变孔板的孔径大小以改变气泡的尺寸,特别研究了泡沫尺寸对泡沫吸附分离的影响。     

大豆蛋白废水中乳清蛋白的泡沫分离实验

采用泡沫分离法回收大豆蛋白废水中蛋白,考察了pH值、气体的流速、进料浓度、液柱和泡沫层高度等因素对分离效果的影响.低进气速度、高泡沫层高度、适当的pH值以及低进料浓度有利于较好的分离.结果表明:当进料浓度为0.54 g/L、pH值为5、泡沫层与液池高度比4∶1,通气量为15.0 L/h 时,富集比可以达到3.25;当进料浓度为0.54 g/L、pH值为5、泡沫层与液池高度比3∶1,通气量为15.0 L/h,此时脱除率可以达到48.5%.     

氨氯地平对小鼠黑色素细胞瘤B16细胞自发性肺转移的抑制作用及其机制

目的 研究氨氯地平对小鼠黑色素细胞瘤B16细胞自发性肺转移的抑制作用及其机制.方法 将小鼠黑色素细胞瘤B16细胞接种于C57BL/6J小鼠右腹股沟皮下,2×106个/只,次日将小鼠随机分为阴性对照组(给予生理盐水0.2 ml/只,每天灌胃1次,共21 d)、氨氯地平低、中、高剂量组(分别给予氨氯地平1、3和10 mg/...     

Preparation and electro‐optical behaviors of polymer stabilized liquid crystal cells with chiral matrices derived from (−)‐camphor

Novel chiral monomers derived from (?)‐camphor and difunctional monomers with biphenyl segments were synthesized. The molecular structures were identified using FTIR, NMR, and elemental analyses. Surface pretreated polymer stabilized cholesteric texture (PSCT) cells with various chiral nematic components were prepared. According to theory, they are kind of reversed mode PSCT cells. The helical twisting power (HTP) and pitches of the PSCT cells were evaluated. The polarized optical microscopic (POM) textures and the dependence of the optical properties on the applied voltage of the PSCT cells were investigated. The reflection band of the PSCT cells before and after UV irradiation were estimated. A blue shift of selective reflection of the PSCT cells was obtained after UV irradiation. PSCT cells with various reflecting colors and the dependence of the transmittance of the cells on applied voltage were investigated. Real image recording through a mask as well as the transmittance of PSCT cells controlled by applied voltage were also confirmed. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 88–96, 2005     

吴茱萸碱对人结肠癌lovo细胞生长的抑制作用

目的探讨吴茱萸碱(Evodiamine,Evo)在体内外对人结肠癌lovo细胞生长的抑制作用及其机制。方法采用MTT法检测Evo对人结肠癌lovo细胞、人乳腺癌MDA-MB-231细胞以及人肺癌A549细胞生长的影响;流式细胞术分析Evo对lovo细胞细胞周期和细胞凋亡的影响;采用Evo治疗lovo细胞荷瘤裸鼠,并绘制肿瘤生长曲线;Westernblot法检测Evo对lovo细胞和肿瘤组织中Bcl-2及procaspase-3表达的影响。结果 Evo能抑制lovo细胞生长(P<0.01),促进MDA-MB-231细胞增殖(P<0.01),对A549细胞无明显作用(P>0.05);可将lovo细胞阻滞于S期(P<0.01),并呈时间依赖性诱导其凋亡(P<0.01);能抑制lovo细胞荷瘤裸鼠肿瘤生长(P<0.05);Westernblot检测结果显示,Evo在体内外均可降低lovo细胞Bcl-2及procas-pase-3的表达。结论 Evo可通过抑制Bcl-2表达,激活caspase-3,诱导凋亡,从而抑制lovo细胞的生长。     

Redirecting Killer T Cells through Incorporation of Azido Sugars for Tethering Ligands

The genetic expression of chimeric antigen receptors (CARs) on the surfaces of T cells enables the redirection of T cell specificity. To enhance the versatility of T cells as tumor-specific killers, we developed a nongenetic approach by which azide-containing sialic acids were metabolically incorporated into T cells to modify cellular sialyl glycans. After successful display of these moieties on the T cells, small-molecule ligands such as RGD and folate (as proof-of-concept, rather than supersized antibodies) were clicked orthogonally, leading to highly selective time- and dose-dependent cytotoxicity to integrin α_vβ₃- and folate-receptor-positive cells, respectively. This chemical approach provides a facile platform for rational design of tumor-specific cytotoxic T cells for targeted immunotherapy.     

Effects of Annealing Conditions of Electrodes on the Photovoltaic Properties of Sintered Cadmium Sulfide/Cadmium Telluride Solar Cells

Polycrystalline n -CdS/ p -CdTe solar cells with a commerical carbon paint on the p -CdTe layer and an In-Ag paint on the n -CdS layer were fabricated by a coating and sintering method. Electrical properties of the conducting paints and solar cell parameters of the heterojunction solar cells were investigated as a function of electrode annealing conditions. The sintered CdS/CdTe solar cells whose electrode contacts were annealed at 350°C for 10 min in nitrogen showed maximum values of short-circuit current density, fill factor, and solar efficiency. Commercial carbon and silver paints can be used as electrodes to fabricate sintered CdS/CdTe solar cells with efficiency over 10%.     

Cell migration and proliferation during monolayer formation and wound healing

The interaction of living cells with surfaces is important in applications of biomaterials, such as tissue engineering. Characterising and modelling the attachment, migration and proliferation of cells on materials used for tissue engineering provides valuable insight into their potential applications as well as a means of objective comparison. In this study, proliferation and migration of NIH-3T3 fibroblast cells on tissue culture plastic in vitro were quantified. The development of randomly scattered individual cells into confluent cell monolayers proceeded with cell density following a logistic growth pattern. Travelling cell wavefronts produced in a wound healing assay were modelled with a modified Fisher equation incorporating both diffusion and logistic growth. The diffusivity and growth rates thus determined could be used for comparison with cell behaviour on other surfaces or under different conditions. Cell tracking showed that the average effective velocity of cells varied inversely with cell density, supporting contact inhibition of cell movement.     

疫苗诱导的特异性细胞杀伤活性检测方法的建立

目的建立一种基于流式细胞术的评价疫苗诱导的特异性细胞杀伤活性的方法,以完善疫苗及基因治疗药物的评价方法。方法用羧基荧光素二乙酸盐琥珀酰亚胺酯(Carboxyfluorescein diacetate,succinimidyl ester,CFSE)标记淋巴细胞,利用肿瘤坏死因子(Tumor necrosis factor,TNFα)模拟杀伤淋巴细胞,用碘化丙啶(Propidium iodide,PI)染色,流式细胞仪检测,确定CFSE和PI的浓度及作用时间。利用已确知有较强细胞免疫作用的治疗性乙型肝炎疫苗免疫小鼠,分离特异性淋巴细胞并用特异性肽刺激,分离未免疫小鼠的淋巴细胞作为靶细胞,并用特异性抗原肽致敏,并从靶细胞的标记、效应细胞培养时间,效靶作用时间、效靶比几方面进行优化,确定试验方法的操作流程。结果采用CFSE/PI双标记能有效分离实验所需各组群,细胞分为CFSE+PI-、CFSE+PI+、CFSE-PI+、CFSE-PI-4个组群,可区分活细胞和凋亡细胞。CFSE标记靶细胞的时间为6 h;效应细胞培养时间为72 h;效靶作用时间为6 h;效靶比可使用100∶1和50∶1。结论建立了基于流式细胞术的评价疫苗诱导的特异性细胞杀伤活性的方法,该方法可有效和精确地评价CTL杀伤效应,完善了疫苗及基因治疗药物的评价方法。     

Enhanced Anti-Tumoral Activity of Methotrexate-Human Serum Albumin Conjugated Nanoparticles by Targeting with Luteinizing Hormone-Releasing Hormone (LHRH) Peptide

Active targeting could increase the efficacy of anticancer drugs. Methotrexate-human serum albumin (MTX-HSA) conjugates, functionalized by luteinizing hormone-releasing hormone (LHRH) as targeting moieties, with the aim of specifically targeting the cancer cells, were prepared. Owing to the high expression of LHRH receptors in many cancer cells as compared to normal cells, LHRH was used as the targeting ligand in this study. LHRH was conjugated to MTX-HSA nanoparticles via a cross-linker. Three types of LHRH targeted nanoparticles with a mean particle size between 120-138 nm were prepared. The cytotoxicity of LHRH targeted and non-targeted nanoparticles were determined on the LHRH positive and negative cell lines. The internalization of the targeted and non-targeted nanoparticles in LHRH receptor positive and negative cells was investigated using flow cytometry analysis and fluorescence microscopy. The cytotoxicity of the LHRH targeted nanoparticles on the LHRH receptor positive cells were significantly more than non-targeted nanoparticles. LHRH targeted nanoparticles were also internalized by LHRH receptor positive cells significantly more than non-targeted nanoparticles. There were no significant differences between the uptake of targeted and non-targeted nanoparticles to the LHRH receptor negative cells. The active targeting procedure using LHRH targeted MTX-HSA nanoparticles could increase the anti-tumoral activity of MTX.     

羧基修饰的超顺磁纳米粒子直接固定化罗伊氏乳杆菌

利用共沉淀法结合高锰酸钾氧化制备所得表面羧基修饰的超顺磁性纳米粒子吸附于罗伊氏乳酸杆菌表面,在磁场协助下实现细胞的固定化。吸附机理分析表明小尺寸相互作用和静电相互作用是磁性纳米粒子与细胞之间的主要作用。分别考察了菌体/磁性粒子质量比、pH、温度、时间等对固定化罗伊氏乳酸杆菌的影响,确定最佳固定条件为菌体与磁性纳米粒子相对质量比为2.25,在pH=3、温度25℃的条件下固定化0.5 h,可实现91%的细胞固定化。最后,对固定化后的细胞进行再培养,与游离细胞相比,两者表现出类似的代谢特征,证实细胞经固定化后仍具有活性。因此,羧基修饰的超顺磁性纳米粒子可成功用于细胞固定化,在不影响细胞活性的情况下,通过磁分离实现细胞的重复利用。     

破骨细胞抑制因子生物活性定量测定方法的建立

目的以破骨细胞为模型,建立抑制破骨细胞功能药物的生物活性定量测定方法。方法将小鼠RAW264.7和SP2/0细胞在含地塞米松和1,25(OH)2VitD3的破骨细胞诱导分化液中混合培养,通过TRAP染色鉴定破骨细胞的成熟。加入不同浓度的rhOPG-Fc,检测其对RAW264.7细胞增殖、分化和成熟破骨细胞活性的抑制作用,计算药物的IC50,并定量计算活性单位。结果rhOPG-Fc对RAW264.7细胞增殖抑制的IC50为0.02mg/L,其生物活性为50U/mg;对RAW264.7细胞分化抑制的IC50为0.02mg/L,其生物活性为50U/mg;对成熟破骨细胞活性抑制的IC50为0.18mg/L,其生物活性为5.5U/mg。结论以破骨细胞抑制因子为候选药物所建立的细胞学模型,可方便快速地定量测定破骨细胞抑制类药物的生物活性,且能协助判断药物的作用机理。