聚乙二醇负载葛根素前药的合成、表征及体外特性初步研究

 目的 合成水溶性好,具有缓释特性并无溶血不良反应的葛根素前药。方法 通过缩合反应以丁二酸为连接臂,将葛根素与单甲氧基聚乙二醇（M_r=5 000,mPEG_5k共价连接,制备聚乙二醇负载的葛根素前药,并通过TLC,UV,1H-NMR 对其进行结构表征;同时测定葛根素前药的水溶性;考察前药在不同pH缓冲液中的释药特性;初步探索前药体外溶血特性。结果 合成了聚乙二醇负载的葛根素前药,鉴定为预期产物。其水溶性较葛根素有较大提高;该前药在酸性的条件下稳定性较好,在pH 7.4的生理环境下能够缓慢持续的释药;体外抗溶血特性研究实验结果表明,该前药可避免葛根素的溶血性不良反应。结论 与葛根素相比,前药水溶性好,并具有一定的缓释效果,而且可以避免溶血特性,有望成为新一代的葛根素制剂。     

右旋龙脑-β-环糊精包合物的制备及其结构表征

目的 研究右旋龙脑-β-环糊精最佳包合工艺,并对其进行结构表征.方法 分别采用饱和水溶液法、超声法、研磨法对右旋龙脑进行包合,以综合评分为指标,筛选最佳包合方法.采用L9(34)正交试验设计,筛选超声法制备包合物的最佳工艺参数.采用薄层色谱(TLC)法、傅里叶红外光谱(FIIR)法、X射线粉末衍射(XRD)法对包合物进...     

磁性固体超强酸催化剂SZ的制备及表征

用水解法制备了固体超强酸SO42-/ZrO2(简写为SZ)和磁性基质Fe3O4负载的固体超强酸SO42-/ZrO2(简写为FSZ).对SZ和FSZ进行了IR,XRD和NH3-TPD表征,IR谱图出现了固体超强酸的特征峰,XRD结果显示催化剂的晶型是以具有催化活性的四方晶相为主,NH3-TPD谱图中出现了代表弱酸位的低温峰和强酸位高温峰,总酸量也很大.     

SBA-16及其改性体的表征和吸附性能研究

本文制备了一种SBA-16介孔材料,通过分别与辛基三甲氧基硅烷(C11H26O3Si)和十八烷基三甲氧基硅烷(C21H46O3Si)产生烷基化反应进行表面改性。SBA-16及其改性材料由氮气在77K时的吸附脱附曲线、小角度X射线散射(SAXS)、红外光谱(FT-IR)、热重分析(TGA)以及材料对气态甲苯、庚烷和水的等温吸附平衡结果进行表征。SBA-16表面烷基化改性后,虽然材料的比表面积、孔容、以及对气态甲苯、庚烷和水的吸附量都变小,但是材料更疏水、更亲和于非极性的物质。     

百合多糖的分离纯化及结构表征

目的:从新鲜百合中提取多糖,通过理化性质及结构分析,为百合多糖生物活性研究提供基础。方法:将新鲜百合洗净切碎,石油醚回流脱脂,经水提醇沉得到多糖粗品,采用DEAE-52纤维素柱层析、SephadexG-100凝胶柱层析纯化分离得到三种多糖。将纯化后的多糖进行初步理化性质鉴定,采用HPLC测定分子量、红外光谱对其结构进行表征。结果:百合多糖I为浅黄色晶体,糖醛酸含量为13.64%,平均分子量为97000;百合多糖II为浅黄色晶体,其糖醛酸含量为10.98%,平均分子量范围220000-465000;百合多糖III为浅黄色粉末,含淀粉,糖醛酸含量14.55%,平均分子量为94000;三种多糖都有C=O、C-O-C、-OH等多糖的特征吸收。结论:通过对百合多糖的理化性质及结构进行研究,为百合多糖药理活性的深入研究和功能性食品的开发提供理论依据。     

孜然挥发油β-环糊精包合物的表征及稳定性研究

目的:探讨分析孜然挥发油β-环糊精包合物的表征及稳定性.方法:应用水蒸气蒸馏法从孜然籽中提取出孜然挥发油,并使用β-环糊精对孜然挥发油进行包合.应用红外光谱对包合物进行表征测定,同时在不同光照、温度、pH条件下对此包合物的稳定性进行测定,并将所得结果进行回顾性的分析.结果:经β-环糊精包合后,孜然挥发油的稳定性得到了加强.结论:经β-环糊精包合后,孜然挥发油的稳定性显著提高,值得进一步推广应用.     

寒凝血瘀证表征模型的建立

目的建立寒凝血瘀证表征模型,为探讨血瘀证生物学基础提供实验模型。方法采用多次冰水冷冻刺激法诱导寒凝血瘀证大鼠模型,采用数码相机拍摄实验大鼠证候表征变化。结果模型大鼠舌质紫暗,舌下脉络增粗增长,与正常大鼠舌质鲜红润泽舌下脉络清晰有明显差异。模型大鼠耳廓润泽、微血管清晰但显暗红较正常大鼠耳廓、微血管略有变化。模型大鼠血液流变学全血黏度和还原黏度高切和低切各项指标与正常组比较均有升高(P<0.05);模型大鼠聚集指数、聚集面积显著高于正常大鼠(P<0.05);模型大鼠血小板最大聚集率显著高于正常大鼠,模型大鼠凝血酶时间和凝血酶原时间显著短于正常大鼠(P<0.05)。结论冰水冷冻20次后,血瘀证表征尤其舌质紫暗和舌下脉络增粗增长显现,符合寒凝血瘀证表征模型评价的基本条件。多次冰水冷冻刺激法造模,方法简单,模型稳定性好。     

In-vivo characterization of DALM in ulcerative colitis with high-resolution probe-based confocal laser endomicroscopy

Recently,the use of confocal laser endomicroscopy(CLE) in the diagnosis of chronic ulcerative colitis(CUC) was reported.In this brief report we aimed to assess the application of probe-based CLE to characterize colonic mucosa and dysplasia in CUC.The study involved a patient presenting long-standing CUC.Confocal imaging of both the inflamed mucosa,a circumscribed lesion(dysplasiaassociated lesional mass),and adjacent colonic mucosa are demonstrated and the correlation between the CLE and histological images...     

Derivation and characterization of Chinese human embryonic stem cell line with high potential to differentiate into pancreatic and hepatic cells

Background  Human embryonic stem cells have prospective uses in regenerative medicine and drug screening. Every human embryonic stem cell line has its own genetic background, which determines its specific ability for differentiation as well as susceptibility to drugs. It is necessary to compile many human embryonic stem cell lines with various backgrounds for future clinical use, especially in China due to its large population. This study contributes to isolating new Chinese human embryonic stem cell lines with clarified directly differentiation ability.

Methods  Donated embryos that exceeded clinical use in our in vitro fertilization-embryo transfer (IVF-ET) center were collected to establish human embryonic stem cells lines with informed consent. The classic growth factors of basic fibroblast growth factor (bFGF) and recombinant human leukaemia inhibitory factor (hLIF) for culturing embryonic stem cells were used to capture the stem cells from the plated embryos. Mechanical and enzymetic methods were used to propogate the newly established human embryonic stem cells line. The new cell line was checked for pluripotent characteristics with detecting the expression of stemness genes and observing spontaneous differentiation both in vitro and in vivo. Finally similar step-wise protocols from definitive endoderm to target specific cells were used to check the cell line’s ability to directly differentiate into pancreatic and hepatic cells.

Results  We generated a new Chinese human embryonic stem cells line, CH1. This cell line showed the same characteristics as other reported Chinese human embryonic stem cells lines: normal morphology, karyotype and pluripotency in vitro and in vivo. The CH1 cells could be directly differentiated towards pancreatic and hepatic cells with equal efficiency compared to the H1 cell line.

Conclusions  This newly established Chinese cell line, CH1, which is pluripotent and has high potential to differentiate into pancreatic and hepatic cells, will provide a useful tool for embryo development research, along with clinical treatments for diabetes and some hepatic diseases.

     

物体的颜色知识和运动知识的独立性表征

目的探讨物体颜色知识和运动知识在大脑中的表征关系。方法对39例脑损伤患者和39例正常对照组进行颜色知识属性判断测验和运动知识属性判断测验。对数据进行群组分析和个体分析。结果群组分析显示,患者在这两个任务上的正确率显著正相关;个体分析发现,5例患者在颜色知识属性判断上的成绩显著好于运动知识属性判断,而另外5例患者在运动知识属性判断上的成绩显著好于颜色知识属性判断。结论物体的颜色知识和运动知识在大脑中存在相对独立的表征,与大脑中概念知识的分布式表征理论相符。