Kinetics study of palm oil hydrolysis using immobilized lipase Candida rugosa in packed bed reactor

Continuous hydrolysis of palm oil triglyceride in organic solvent using immobilized Candida rugosa on the Amberlite MB-1 as a source of immobilized lipase was studied in packed bed reactor. The enzymatic kinetics of hydrolysis reaction was studied by changing the substrate concentration, reaction temperature and residence time(tau) in the reactor. At 55 degrees C, the optimum water concentration was found to be 15 % weight per volume of solution (%w/v). The Michaelis-Menten kinetic model was used to obtain the reaction parameters, Km(app) and V max(app). The activation energies were found to be quite low indicating that the lipase-catalyzed process is controlled by diffusion of substrates. The Michaelis-Menten kinetic model was found to be suitable at low water concentration 10-15 %w/v of solution. At higher water concentration, substrate inhibition model was used for data analysis. Reactor operation was found to play an important role in the palm oil hydrolysis kinetic.     

True histiocytic lymphoma of the esophagus in an HIV-positive patient: an ultrastructural study

A 56-year-old white woman, seropositive for human immunodeficiency virus for 18 months without signs of acquired immunodeficiency syndrome, presented with retrosternal pain and progressive dysphagia secondary to an exophytic esophageal mass. Biopsies of the tumor showed a malignant neoplasm composed of pleomorphic, noncohesive cells growing in a diffuse, sheet-like fashion. Immunohistochemically, tumor cells were nonreactive with epithelial, lymphoid, neural, and monocyte/macrophage markers. Despite the noncontributory immunohistochemical findings, ultrastructural study of the tumor cells revealed convincing histiocytic features. Individual cells possessed long, slender filopodial projections, prominent Golgi apparatus, residual bodies, rare lysosomes, and prelysosomes. Immunoglobulin heavy chain and T-cell receptor gamma gene rearrangement studies detected no evidence of a clonal gene rearrangement. The patient responded poorly to chemotherapy and died 5 months after her initial symptom of dysphagia.     

氧化铝颗粒大小对PEO—NaSCN络合物电导率的影响

研究分散第二相Ａｌ２Ｏ３的含量及颗粒大小对ＰＥＯ－ＮａＳＣＮ络合物电导的影响,结果表明：当颗粒度为０．７μｍ时,电导率比纯ＰＥＯ－ＮａＳＣＮ提高了一个半数量级。颗粒度较大时,电导率均比纯ＰＥＯ－ＮａＳＣＮ低,并在ｗＡｌ２Ｏ３＝０．２５时,存在电导率最大的峰值。     

共培养在小鼠胚胎发育过程中的作用

目的 通过人子宫内膜上皮与小鼠胚胎共培养,了解其对胚胎发育的影响。方法 观察共培养２４、３６ｈ及６０ｈ后的小鼠胚胎,并分级,结果 １共培养组停留于２细胞胚胎数显著少于对照组;２共培育２４、３６ｈ后,鼠胚１￣３有胚胎比例较对照组增加,差异有显著性;６０ｈ后,１￣３级胚胎比较与对照组相比差异无显著性。结论 人子宫内膜上皮与小鼠胚胎短期共培养有利于改善胚胎质量。     

三种镍化合物诱发转化细胞恶性度的鉴别与分析

目的 :利用已建立的三种镍化合物体外转化细胞进行裸鼠体内成瘤实验研究 ,比较它们恶性度的差异。方法 :三种镍化合物转化细胞接种BALB/C裸鼠 ,进行肿瘤细胞和转化细胞的透射电镜及扫描电镜观察。结果 :硫化镍 ,氯化镍 ,硫酸镍分别诱发的转化细胞都能在BALB/C裸鼠皮下形成肿瘤 ,病理组织学检查确定为纤维肉瘤。经扫描电镜与透射电镜观察瘤细胞形态与转化细胞有一定差别。结论 :本文进一步说明了三种镍化合物所诱发的细胞转化为恶性转化 ,且都具有体内致瘤性。     

(-)-Epiafzelechin: cyclooxygenase-1 inhibitor and anti-inflammatory agent from aerial parts of Celastrus orbiculatus.

An inhibitor of cyclooxygenase (COX)-1 activity of prostaglandin H2 synthase was isolated from aerial parts of Celastrus orbiculatus Thunb. (Celastraceae), an oriental folk medicine for rheumatoid arthritis by activity-guided column chromatographic methods. The COX inhibitor was identified as (-)-epiafzelechin, a member of flavan-3-ols by the structural analysis with HR-EI-mass, 1H-NMR and 13C-NMR spectral data. The compound exhibited a dose-dependent inhibition on the COX activity with an IC50 value of 15 microM. (-)-Epiafzelechin exhibited about 3-fold weaker inhibitory potency on the enzyme activity than indomethacin as a positive control. (-)-Epiafzelechin exhibited significant anti-inflammatory activity on carrageenin-induced mouse paw edema when the compound (100 mg/kg) was orally administrated at 1 h before carrageenin treatment.     

A study on analysis of particle size distribution

Analysis of particle size distribution of a sample of fine aluminum hydroxide powder was carried out by four different methods,i. e., conductivity, air permeability, gas-adsorption and sedimentation. Each method was reproducible. The results obtained by Coulter counter and sedimentation balance were similar, and the data obtained by Lea and Nurse permeameter and Stroehlein areameter were also similar. But the results differ considerably between the former and the latter. The advantages and disavantages of each method were discussed briefly and a means of comparing the results with those obtained by surface area measurements was shown.     

腹腔注射丹参注射液对新生大鼠缺氧缺血性脑损伤的影响

目的：观察腹腔注射丹参注射液对新生大鼠缺氧缺血性脑损伤(HIBI)后血浆、皮层β-内啡肽、亮啡肽免疫活性物质(ir-β-EP、ir-LEK)含量的影响。方法：在新生大鼠HIBI后即刻及其后每12h向腹腔注射丹参注射液，每次每只0．5mL。采用放射免疫分析法观察损伤后不同时间血浆、皮层ir-β-EP、ir—LEK含量的变化。结果：HIBI后血浆ir-β-EP、ir—LEK含量、患侧皮层ir-β-EP含量不同程度升高，而以血浆ir-β-EP升高更明显、持续时间更长。腹腔注射丹参后血浆、患侧皮层ir-β-EP水平的上升被部分逆转，以血浆升高的抑制更为显著。结论：外周及中枢β-内啡肽、亮啡肽参与HIBI的病理生理过程；腹腔注射丹参注射液部分逆转新生鼠HIBI后外周和中枢ir-β-EP水平的异常升高．可能是丹参促进损伤后脑功能恢复的作用之一，     

补肾益骨膏对大鼠肝肾的损害作用

目的:观察连续给予补肾益骨膏对大鼠肝、肾的损害作用及其损害的可逆性.方法:将144只大鼠分成对照组,补肾益骨膏高、低剂量组,各组动物按1.5 mL•kg 1等体积分别灌胃,高、低剂量组分别按60.0,15.0 g•kg 1给予补肾益骨膏,对照组给予等体积的纯化水,每天连续灌服给药,周日休息,共180 d;用药90,180 d及停药30 d,分3批处死动物,采血进行与肝、肾功能相关的血清生化检测及其病理组织学检查.结果:补肾益骨膏长期给药对肾脏有可疑损害作用,对肝脏有轻度可逆性损害作用.结论:临床长期大剂量使用补肾益骨膏应注意肝、肾功能的检查.     

Nucleus24M型人工耳蜗植入后电极阻抗的变化

目的：研究人工耳蜗植入后电极阻抗的变化规律，以便确定术后进行映射调图的时间表。方法：对16例植入Nucleus CI24M型人工耳蜗患者，于术中及术后1、1．5、2、4、6个月进行电极阻抗测试，统计分析电极阻抗的变化规律。结果：患者电极阻抗在术中检测时最低，开机时最高，以后若干次随访时，阻抗逐渐下降，并在2～4个月左右趋于稳定。结论：电极阻抗的稳定提示耳蜗内生物组织的病理过程渐趋稳定；对心理物理测试配合良好的患者，术后只进行2～4个月左右的映射调图即可。