冻干麻疹减毒活疫苗残余水分影响因素的探讨

影响冻干制品残余水分的因素很多,但西林瓶胶塞的含水量是其关键因素。使用经干烤工艺处理和未干烤处理的药用溴丁基胶塞进行麻疹减毒活疫苗冻干试验,结果显示,用未经干烤工艺处理及处理的药用溴丁基胶塞冻干的麻疹减毒活疫苗,存储18个月后,水分上升的平均值分别为2.03%和0.08%,经单一因素的方差分析,两者有统计学意义(P0.01)。证明经处理的药用溴丁基胶塞,对保持麻疹减毒活疫苗在存储期内的残余水分稳定作用效果明显。     

冻干乙型脑炎减毒活疫苗的冻干工艺优化研究

为了研究优化冻干乙型脑炎减毒活疫苗的冻干工艺,运用正交试验法L934考察不同冻干参数对该疫苗成品质量的影响,以外观、残余水分、病毒滴度以及热稳定性为直观分析指标,并对病毒滴度进行方差分析。结果显示,主干燥时间和主干燥真空压力对病毒滴度的影响有显著统计学意义(P<0.05)。优化的冻干参数为预冻温度-35℃、时间2h;主干燥温度从-35℃升温至-10℃,再由-10℃升温至33℃,总耗时16h,真空压力0.220mbar;二次干燥的温度维持于30℃,真空压力为0.001mbar,终点测试压力无变化时结束。对冻干乙型脑炎减毒活疫苗冻干参数筛选优化后,可得到较佳的冻干曲线,经验证该曲线适用于生产。     

容量滴定法和库伦滴定法测定冻干疫苗水分含量的比较

目的在适宜的温度和湿度条件下,评价容量滴定法和库伦滴定法测定冻干疫苗水分是否具有差异性。方法确定冻干疫苗水分测定的适宜温度和湿度条件,在此条件下,分别从水分含量区间、冻干疫苗类型和进样量三个主要影响方面,对容量滴定法(volumetric titration)和库伦滴定法(coulometric titration)进行比较。结果冻干疫苗水分测定的适宜条件为:温度25℃、湿度45%。冻干疫苗水分的质量分数为1.0%～2.0%时,容量滴定法和库伦滴定法的检测结果差异有统计学意义(P0.05);水分的质量分数在2.0%～3.0%时,两种滴定法的检测结果差异无统计学意义(P0.05)。对于不同类型冻干疫苗和不同进样量的冻干疫苗,两种滴定法检测结果差异均无统计学意义(P均0.05)。结论在适宜的温度和湿度条件下,库伦滴定法更适用于低水分含量冻干疫苗的水分测定;其他情况下两种滴定法无明显差异。     

人脐带血有核细胞冷冻干燥保存实验初步研究

脐带血中的造血干细胞有着广泛的应用前景,随之而产生的保存问题已成为关注的热点。目前已有低温保存的研究,但未有冻干成功的报道。实验试图用冻干的方法来长期保存脐带血中的造血干细胞。冻干过程中选用PVP、HES和各种糖类作为保护剂,一次干燥阶段搁板温度控制在-30℃,二次干燥时搁板温度控制在 15℃,整个冻干过程为52．5h。冻干后复水性能极佳,能够在30s内完全复水,用显微染色观察,细胞形态完整;用流式细胞仪进行PI染色和CD34^ 抗体跟踪检测,测得有核细胞存活率为55．67％,CD34^ 抗体跟踪检测得到CD34^ 细胞占淋巴细胞的3．61％。     

不同干燥技术对金银花药用品质的影响

采用真空干燥、冷冻干燥、微波干燥、蒸后烘干、烘干和晒干等6种干燥技术对大白期金银花花蕾外观性状及内在品质的影响进行分析研究.结果表明:(1)微波干燥、蒸后烘干和冷冻干燥所获得的金银花外观品质好;(2)从水溶出物量和醇溶出物量上看,微波干燥、蒸后烘干和晒干技术所获得的溶出物量高;用比色法和HPLC法检测显示,蒸后烘干样品中有效成分———绿原酸、总黄酮含量最高,其次是微波干燥法,而烘干样品中含量最低;(3)不同干燥技术对金银花中营养成分———游离氨基酸和可溶性糖含量的影响以及对药用有效成分的影响不同,因此金银花作为药材使用时应选择蒸后烘干技术进行初加工;(4)晒干、冷冻干燥和微波干燥3种干燥方法对金银花挥发油主要组分种类没有产生影响,但相对质量分数仍有明显差异,只有晒干的金银花挥发油中检测出了9,19-环化-羊毛甾烯醇,而微波干燥的样品中维生素E含量最高,挥发油中γ-5-谷甾烯-3-醇、5,2-豆甾二烯-3-醇、菜籽甾醇相对含量较其它方法明显高出很多.因此,蒸后烘干和微波干燥技术可作为规模化干燥加工金银花的最佳方法.     

真空冷冻干燥过程中微生物数量变化规律的初步研究

真空冷冻干燥技术是将含水物料中的水冷冻成固态冰,在高真空条件下利用水的升华性能,使物料在较低温度脱水而达到干燥目的的一种干燥方法。本研究将对市售的胡萝卜、香菇进行真空冷冻干燥,通过控制冻干的最终温度以及达到终结温度后的冻干时间,比较冻干前后各批次果蔬中微生物的数量(包括细菌总数以及大肠菌群总数),得到果蔬冻干过程中冻干过程中微生物的变化规律。结果显示胡萝卜、香菇在冻干过程中微生物数量的变化与温度、干燥时间呈正相关,在终结温度为60℃,干燥时间为6 h的情况下,干品品相良好,并能成功抑制微生物的生长。     

红外吸收法检测西林瓶包装冻干制品中的氧含量

目的应用HSA-P型激光检漏仪建立西林瓶包装冻干制品中氧气含量的测定方法。方法考察冻干制品中氧含量测定的操作条件:标准样瓶对仪器的校准;氮气吹扫前后样品中氧含量值的比较;不同纯度氮气吹扫标准样瓶后的氧含量值的变化。深化红外吸收法在测定西林瓶包装冻干疫苗中氧含量的应用。结果将该方法用于检测A群C群脑膜炎球菌多糖疫苗400批、麻疹减毒活疫苗86批、乙型脑炎减毒活疫苗46批,氧含量分别为1.64%±1.99%、1.36%±1.64%和0.99%±1.58%。结论该法测定冻干疫苗中的氧含量具有灵敏度高、速度快和易操作的优点,为冻干制品真空度的测定提供了定量检测方法。     

人凝血酶原复合物在制备过程中凝血因子活性的检测和分析

目的对人凝血酶原复合物在制备工艺中凝血因子效价进行检测和分析。方法对PCC制备过程中的血浆、S/D病毒灭活、冻干工艺、干热病毒灭活前和后分别取样,检测分析凝血因子Ⅱ、Ⅶ、Ⅸ和Ⅹ效价,分别分析S/D病毒灭活、冻干工艺、干热病毒灭活前和后凝血因子效价的变化情况。分析PCC干热病毒灭活后的样品中四种凝血因子的效价比例。结果三批血浆中凝血因子Ⅱ、Ⅶ、Ⅸ和Ⅹ的活性在0.8~1.2 IU/m L之间。S/D病毒灭活前后PCC冻干工艺前后PCC中四种凝血因子活性无明显变化,而干热病毒灭活后PCC中四种凝血因子活性均有明显下降。三批PCC中四种凝血因子的比例基本一致,但是凝血因子Ⅶ效价较低,凝血因子Ⅱ效价偏高。结论通过PCC制备工艺中凝血因子效价的检测和分析可实现良好的质量控制。     

保藏菌种的先进方法

目前保藏细菌的常用方法有:①根据不同菌种低温保藏,隔双周或隔月移种传代,②在很低的温度下。使微生物细胞快速冻结且保持完整,然后在真空下使水分升华达到干燥,即冻干保存。前种操作简     

高水分、富含淀粉植物组织的扫描电镜制备技术优化

应用常规高真空扫描电子显微镜观察生物样品必须经过脱水和干燥处理,但无论采用临界点干燥还是冷冻干燥方法,都存在样品表面不同程度失真的问题。植物高水分、富含淀粉组织样品经处理后,容易出现淀粉流失、细胞壁变形等现象,从而造成扫描图像粗糙,无法获得真实的细胞内部结构。本文通过对CO_2临界点干燥、化学固定样品冷冻干燥和新鲜样品冷冻干燥3种扫描电镜样品制备技术中后期制样进行机械断裂和液氮脆断改进,优化出两种植物高水分、富含淀粉组织的扫描电镜样品制备方法:(1)样品首先进行FAA化学固定,经冷冻干燥后用液氮脆断,对断面喷金镀膜和扫描电镜观察。利用该方法所得细胞结构完整,细胞壁整齐,淀粉粒和蛋白轮廓明确,可用于分析淀粉粒和蛋白颗粒在细胞内的分布。(2)新鲜样品直接进行冷冻干燥,经液氮脆断后对断面喷金镀膜和扫描电镜观察。利用该方法所得细胞壁整齐,淀粉粒轮廓更清晰,并且无蛋白颗粒干扰,用于分析淀粉粒在细胞内的分布更加理想。     

Factors influencing changes in moisture content during storage of freeze-dried vaccines in vials

Previous studies have demonstrated that the water content of freeze-dried vaccines increases during storage. The reasons for these variations in water content are discussed in this paper. Different possible mechanisms have been considered: microleakages at the closure sealing point, water vapour transfer through the closure (permeation, loss and uptake of water by the stopper). Several types of vials and closures were studied, under different conditions of storage. Regardless of the vial form selected, the probability of microleakages was low. The stopper would seem to play an important role in the water transfer mechanisms. The moisture content of the stopper determines its equilibrium relative humidity (ERH) and whether there will be moisture transfer between the stopper and the vial contents and between the stopper and the storage atmosphere.     

Loss of vacuum in rubber stoppered vials stored in a liquid nitrogen vapor phase freezer

A total of 1885 rubber stoppered 3-ml vials (NS-33 and NS-51 glass (expansion sizes), sealed under vacuum, were subjected to the ultracold temperatures of a liquid nitrogen vapor phase (LNVP) freezer for 16.5 hr and tested for vacuum loss after equilibration back to 25 °C. The presence of a vacuum in each vial was checked before and after freezing. Results with two lots of vials per glass expansion size showed positive or no negative pressure rather than a vacuum in 46.25% (NS-33), 98.25% (NS-33), 64.72% (NS-51), and 99.38% (NS-51) of the vials. Apparently, the fit or slight misfit of the stopper into the vial opening and the hardness of the butyl rubber stopper at ultracold temperatures enhance the chances of leakage around the stopper area under extremely cold temperatures. Storage of rubber stoppered vials containing lyophilized products sealed under vacuum in LNVP freezers is not advisable.     

不同树龄橡胶林土壤水分和细根生物量

采用根钻法,分析了橡胶幼树期(5 a)、初产期(9 a)和旺产期(16 a)林下土壤水分特征及橡胶树细根生物量.结果表明:橡胶树龄越大,土壤含水量越高,而橡胶树细根生物量越少;不同树龄橡胶林0～60 cm土壤含水量随着土层深度的增加而升高,年内变化则呈"双峰"型;不同树龄橡胶树细根生物量最大值均出现在10 cm土层,且随着土层深度的增加而减少,细根生物量年内变化同样呈"双峰"型,但不同树龄细根生物量峰值的出现时间不一致.土壤含水量和土层深度是橡胶树细根生物量的主要影响因子.     

Effect of drying period and soil moisture on egg hatch of the tadpole shrimp (Notostraca: Triopsidae).

Tadpole shrimp (Triops spp.) are potential biological control agents against larval mosquitoes in temporary ponds and flood-irrigated fields. In some rice field situations, however, they may become pests that uproot and eat young rice plants. In cursory observations, it has been reported that tadpole shrimp eggs do not readily hatch on flooding when the soil or substrate containing eggs is moist before flooding. The relationship between drying (moisture content) of soil and tadpole shrimp hatch was determined in studies conducted in mesocosms at the University of California Aquatic and Vector Control Research facilities at Riverside and at Oasis in the Coachella Valley of southern California. In laboratory hatching trials, an increase in hatch of Triops longicaudatus (LeConte) with declining soil moisture content was demonstrated (t = 8.4, P less than 0.001; r2 = 0.76). In field trials in mesocosms at Riverside, egg hatch increased with increased drying period and declining soil moisture content (G = 29.8, P less than 0.01). No hatch of eggs occurred after 3 d of drying, when soil moisture content was high, but a high level of hatching occurred after 7 and 14 d of drying, when soil moisture declined to low levels. At Oasis, soil moisture did not decrease with drying time because of porous soil and capillary action of water from adjacent flooded mesocosms and thick vegetation covering the pond bottoms. Therefore, hatch rates at Oasis were not associated with the length of the drying period (G = 35, P greater than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

The effect of time of harvest on the viability and pre-emergence mortality in soil of pea (Pisutn sativum L.) seeds

A series of harvests from field plots of peas showed that the younger seeds were at the time of harvest the lower was their percentage viability and the greater their percentage mortality in soil. Young seed also showed a high degree of solute leaching into steep water and had a high moisture content at harvest compared with older seeds. Heavy rainfall just prior to harvesting reduced the percentage viability of the dried seed and increased the moisture content of the seed at harvest as well as the leaching of solutes from the dried seed into steep water. Comparisons of moisture content at harvest and seed condition after drying suggested that cotyledons and embryo axes were only able to withstand enhanced drying after removal from the plant if the seed moisture content had already begun to decline whilst the seed was still on the plant.     

The effects of some storage conditions on viability of Lecanicillium lecanii conidia to whitefly (Homoptera: Trialeurodes vaporariorum)

A study on the survival of Lecanicillium lecanii conidia in storage at room temperature was carried out. Firstly, drying methods of conidia powder were compared. Vacuum-freeze drying (VFD) was more suitable for drying conidia as compared to vacuum drying (VD) at room temperature. Vacuum-freeze drying for 24-h resulted in a water content of 5.4%, and a viability, determined as germination of conidia in 2% glucose solution after16 h, was 90.3% and the infection in greenhouse whitefly, Trialeurodes vaporariorum was about 94.7% at a dose of 1×10⁸ conidia/mL. Secondly, the factors influencing viability of conidia stored at room temperature were evaluated in the laboratory. Temperature was the most critical factor influencing conidial storage stability, among the tested factors affecting survival of conidia stored at room temperature for 6 months. Both conidial germination and infection of hosts decreased with storage temperature increasing from 15 to 35°C, and at 35°C the survival of stored conidia for 6 months was near zero. The moisture content of the conidial powder was another major factor influencing viability of stored conidia at room temperature. Conidial powder dried to about 5% moisture content showed higher viability than non-dried conidial powder. For the carriers, clay and charcoal were more suitable for storage of L. lecanii conidia at room temperature. At a room temperature of 25°C, L. lecanii conidia which were dried to 5% water content and mixed with clay or charcoal could retain about 50% survival after 6 months' storage.     

Effect of viscoelastic relaxation on moisture transport in foods. Part II: Sorption and drying of soybeans

The general fluid transport equation presented in Part-I of this paper is used for predicting moisture transport and viscoelastic stresses during sorption and drying of soybeans. Predicted drying curves were validated using experimental data obtained from literature (average absolute difference 6-13%). For drying temperatures used in the soybean processing industry (70–93 °C), smooth moisture profiles were obtained, which indicated Fickian (Darcian) transport. As the drying temperature approached the glass transition temperature (25 °C at 10% moisture content), the moisture profiles became sharper, which indicated non-Fickian (non-Darcian) transport. The viscoelastic stress profiles clearly exhibited the role of the force terms during imbibition and drying. Increase in drying temperature tends to decrease the stress relaxation function but reduction in moisture content during drying tends to increase it. The increase in stress due to the reduction in moisture content below 10% was not compensated by an increase in drying temperature. Drying of soybeans below 10% moisture content should be avoided in the industry because this will lead to thicker flakes that reduce the amount of oil recovery. During imbibition of soybeans, a high magnitude of stresses was obtained in the rubbery regions, which may cause critical regions prone to fissuring. The role of glass transition on stress development and critical region development was clearly observed during drying and imbibition of soybeans.Revised version: 5 October 2003     

Soil moisture dynamics and restoration of self‐sustaining native vegetation ecosystem on an open‐cut coal mine

Post‐mining landscape reconstruction on open‐cut coal mines aims to support restoration of self‐sustaining native vegetation ecosystems that in perpetuity require no extra inputs relative to unmined analogs. Little is known about the soil moisture retention capacity of the limited layer of topsoil replaced (often <30 cm deep), impacts of deep ripping of the profile, and the combined impacts of these on plant available water during the mine restoration process. We examined changes in soil moisture parameters (soil water potential, Ψ, and soil water content, Θ) daily using automated soil sensors installed at 30 and 45–65 cm depths on mine restoration sites aged between 3 and 22 years and on adjacent remnant vegetation sites following heavy rainfall events at Meandu mine, southeast Queensland, Australia. Consistent patterns in soil moisture attributes were observed among rehabilitated sites with generally marked differences from remnant sites. Remnant site soil profiles had generally higher Θ after drying than rehabilitated sites and maintained high Ψ for extended periods after rain events. There was a relatively rapid decline of Ψ on reconstructed soil profiles compared with remnant sites although the times of decline onset varied. This response indicated that vegetation restoration sites released soil moisture more rapidly than remnant sites but the rate of drying decreased with increasing rehabilitation age and increased with increasing tree stem density. The rapid drying of mine rehabilitated sites may threaten the survival of some remnant forest species, limit tree growth, and delay restoration of self‐sustaining native ecosystem.     

模拟降雨对西双版纳热带次生林和橡胶林土壤呼吸的影响

降雨作为一个重要的环境因子,对土壤呼吸具有重要的影响。研究土壤呼吸与降雨的关系,对准确估算大气中的CO2含量具有重要意义。本研究通过人工模拟降雨事件,应用野外原位测定方法,测量了热带次生林和橡胶林土壤呼吸速率、地下5cm土壤温度和土壤含水量的变化,以探究热带两种主要植被类型的土壤呼吸、土壤温度、土壤含水量对旱季单次降雨事件的响应过程与规律。研究发现,在旱季连续一周没有降雨的情况下,人工模拟降雨事件使土壤呼吸在降雨后的2h内被迅速激发,次生林的土壤呼吸最大达到11.15 μmolCO2·m-2·s-1,是对照的近7倍;橡胶林的土壤呼吸最大达到了15.88 μmolCO2·m-2·s-1,是对照的近11倍。随后激发效应迅速降低,尤其是橡胶林,在人工模拟降雨6h后处理与对照间无显著差异。人工模拟降雨前两种林型的土壤含水量与对照相比均无显著性差异,人工模拟降雨后的2d内土壤含水量均显著高于对照;人工模拟降雨前后土壤温度与对照相比均无显著性差异。本研究结果支持了"Birch effect",2种主要热带林型在旱季时期,由于单次降雨事件激发而释放到大气中的CO2是降雨前的数倍。