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1.
麻黄生物总碱提取生产工艺改进   总被引:1,自引:0,他引:1  
设计考察了一种新的麻黄生物碱提取生产工艺,旨在解决现生产中的污染问题。在碱性条件下将麻黄生物碱盐苛化为生物碱形式,直接用二甲苯提取后,用2%草酸将生物碱转化为草酸盐萃取,二甲苯在工厂原有设备基础上回收循环利用,在解决污水问题的同时,简化工艺。采用析因试验确定最佳提取条件,包括提取温度、加饱和氢氧化钠量、麻黄草的粉碎程度。并考查了提取时间对提取率的影响;建立测定提取液中生物碱含量的方法。  相似文献   

2.
The synthesis of brain-specific proteins has been examined in perikaryal and axonal regions of the giant fibre system of the squid. After in vitro incubation of stellate ganglia, stellate nerves and isolated giant axons with radioactive amino acids, the labelled soluble proteins have been extracted from the giant fibre lobe, the axoplasm and the axonal sheath of the giant axon and have been separated by gel electrophoresis on a continuous system. In addition, they have been challenged with antisera prepared against the cephalopod brain-specific proteins L1 and L2 and the resulting precipitate has been resolved by sodium dodecyl sulphate-gel electrophoresis. Synthesis of these two proteins appears to be restricted to the giant fibre lobe, while an additional discrete protein band (L5) also becomes clearly labelled in the isolated giant axon. Radioactive components migrating in the region of the L1 and L2 proteins are synthesized in the isolated giant axon. They can be distinguished from tbese proteins on the basis of electrophoretic and immunochemical criteria.  相似文献   

3.
1. The theory of electrical conductance of colloidal suspensions has been extended to cover the case of ellipsoids with three axes different. 2. The results have been applied to suspensions of ellipsoidal erythrocytes of birds. 3. It has been shown that fluctuations in electrical resistance of suspensions of erythrocytes after stirring are due to streaming orientation of the cells. 4. The theory has been extended to cover four cases of orientation and tested experimentally in specially designed flow cells by electrical and optical methods. 5. Application of the flow method to the study of the shape of colloidal particles is discussed.  相似文献   

4.
A rich collection of Silurian vertebrate remains, including abundant thelodont and acanthodian scales, has been made from recent borings on the Estonian island of Saaremaa (Ösel). Thelodonts have been reported for the first time at the top of the Jaagarahu Stage, as have anaspids from the Rootsiküla (formerly Kaarma) Stage, and acanthodians from the Paadla Stage. Arthrodires as well as actinopterygians (?), represented by the genus Andreolepis, have been found for the first time on Saaremaa. Arthrodires appear to be the oldest known members of this group. The recent stratigraphical classification of the Silurian of Estonia has been taken into account, and the stratigraphical distribution of the vertebrate genera and species is given. The correlation between some of the vertebrate-bearing beds of Saaremaa, Gotland, and the southern Baltic is also discussed.  相似文献   

5.
6.
A comparative analysis of the fine structure of the microvilli on jejunal and colonic epithelial cells of the mouse intestine has been made. The microvilli in these two locations demonstrate a remarkably similar fine structure with respect to the thickness of the plasma membrane, the extent of the filament-free zone, and the characteristics of the microfilaments situated within the microvillous core. Some of the core microfilaments appear to continue across the plasma membrane limiting the tip of the microvillus. The main difference between the microvilli of small intestine and colon is in the extent and organization of the surface coat. In the small intestine, in addition to the commonly observed thin surface "fuzz," occasional areas of the jejunal villus show a more conspicuous surface coat covering the tips of the microvilli. Evidence has been put forward which indicates that the surface coat is an integral part of the epithelial cells. In contrast to the jejunal epithelium, the colonic epithelium is endowed with a thicker surface coat. Variations in the organization of the surface coat at different levels of the colonic crypts have also been noted. The functional significance of these variations in the surface coat is discussed.  相似文献   

7.
不同的栽培技术措施对银杏苗木生长的影响   总被引:1,自引:1,他引:0  
李家玉  叶火华   《广西植物》1987,(4):333-338
通过苗圃栽培试验,研究了不同栽培技术条件下苗木的生物量,对比了施肥、断胚根、遮荫等技术措施的效果,并用析因试验的方法进行分析,认为关键性技术措施是重施基肥。  相似文献   

8.
Radical mastectomy is excellent only for cases of operable breast cancer in which the tumor is limited to the breast or to the nodes in the axilla. That there is metastasis to the internal mammary lymph nodes in a high proportion of cases has been “overlooked” for many years. Also it is probable that metastasis occurs to the supraclavicular lymph nodes more often than is suspected. Hence the extended radical mastectomy operation leaves much to be desired. There has been no significant improvement in recent years in the mortality rate of mammary cancer.Simple mastectomy and thorough adequate postoperative radiation therapy have much to offer.Treatment of “operable” breast cancer should be a cooperative effort of surgeon, radiation therapist and pathologist.  相似文献   

9.
松毛虫卵期几种寄生蜂的共寄生现象及其对寄生率的影响   总被引:1,自引:0,他引:1  
倪乐湘  童新旺 《昆虫学报》1994,37(2):145-152
松毛虫赤跟蜂 Trichogramma dendrolimi Matsumura 白跗平腹Pseudanastatusalbitarsis Ashmead松毛虫宽缘金小蜂Pachyneuron olitarium(Harig), 松毛虫黑卵蜂 Telenomus dendrolimusi Chu和大蛾卵跳小蜂Ooenvyrtus Kuwanae(Howard)是松毛虫卵期几种主要寄生蜂。通过对上述几种寄生蜂寄生习性的研究表明:赤眼蜂和平腹小蜂不但能寄生新鲜害虫卵,还可以寄生对方已寄生并巳发育1-3天的寄生卵,但羽化串均不高;松毛虫宽缘金小蜂不寄生新鲜害虫卵,专门寄生赤眼蜂寄生后巳发育1-7,天的寄生卵,其中又以赤眼蜂发育3-5天的卵寄生串和羽化率为最高。除赤眼蜂和平腹小蜂可以混合使用外,其它蜂种混用都不同程度地存在相互排挤的现象。如果先让平腹小蜂寄生尔后再让赤眼蜂寄生或先让赤眼蜂寄生,尔后再让跳小蜂或黑卵蜂寄生,能够提高卵块寄生串和充分发挥各自天敌的作用。  相似文献   

10.
Extensive research to trace the cause of Hodgkin''s disease to a bacterial or protozoan agent has proven fruitless.Although a viral cause for Hodgkin''s disease has been previously suggested, early explorations along that line have not been confirmed. With the development of newer techniques for the study of viral characteristics certain apparently significant factors in Hodgkin''s disease have been encountered. Most promising has been the consistent demonstration that Seitz-filtered, sterile Hodgkin''s disease lymph node extract can be passed serially in fertile chicken eggs and that the amniotic fluid from these eggs possesses the capacity to interfere with the growth of influenza virus in eggs.  相似文献   

11.
Drug sensitive clones have been isolated from a population of HeLa cells after treatment with methyl methane sulphonate (MMS). One of these clones has now been studied in more detail and some possible mechanisms of drug sensitivity have been related to the proliferation kinetics of the cells of this clone. The cell cycle is elongated and labelling techniques show this elongation to be confined to the G1 phase. Synchronized cultures have shown that the G1 phase is more sensitive to MMS than the S phase. These observations provide some explanation for the drug sensitivity of this clone of cells.  相似文献   

12.
运用核磁共振氢谱(PMR谱)~(**)对各类酵母的细胞壁甘露聚糖进行比较研究,在我国尚无报道,其中某些酵母也尚无文献记载。本文结果表明:1.同菌株的胞壁甘露聚糖PMR谱型的重复性很好。2.同种不同株的酿酒酵母(Saccharomyces cerevisiae)的多糖谱型也相同。3.所测的二端芽殖酵母中完全型与不完全型菌株的谱型很相似,如柠檬形克勒克酵母(Kloeckera apiculata)与葡萄有孢汉逊酵母(Hanseniaspora uvarum。4.某些分类系统上来源较杂的子囊菌酵母如单宁管囊酵母(Packysolen tanophilus)、萤光威克酵母(Wickerhamiaflurescens)与高糖固囊酵母(Citeromyces matritensis)则体现了各不相同的谱型。5.二株分自西双版纳的极为相近的类酵母(Saccharomycodes sp.)其多糖的(PMR)谱型与多糖的组分都彼此相同,有助于对它们的适当归类。这一切证明酵母胞壁多糖PMR谱型相似程度的比较是分类上较有意义的性状,有助于探讨亲缘关系,核实完全型与不完全型,也有助于对疑难菌株的分析  相似文献   

13.
SUMMARY: The inhibition by tannins of sulphate-reducing bacteria in pure culture has been shown to be due primarily to the establishment of an unfavourable pH. High concentrations were required to inhibit when the physico-chemical conditions were otherwise favourable.  相似文献   

14.
中国杀虫药剂毒理研究进展概况   总被引:5,自引:0,他引:5  
陈巧云 《昆虫知识》1992,29(3):156-159
<正> 杀虫剂的应用历史悠久,但是由于应用杀虫剂防治害虫而兴起的杀虫药剂毒理学却是一门比较年轻的科学。它虽然研究哪些物质对昆虫有毒,产生什么中毒征象,然而其主要任务是研究杀虫药剂杀死昆虫的机制以及昆虫对杀虫药剂的反应。它还包括环境及昆虫生理状态等因素对杀虫剂毒杀作用的影响,以及杀虫剂对  相似文献   

15.
Apparatus has been designed and constructed for the measurement of the electric impedance of suspensions of Arbacia eggs in sea water to alternating currents of frequencies from one thousand to fifteen million cycles per second. This apparatus is simple, rugged, compact, accurate, and rapid. The data lead to the conclusions that the specific resistance of the interior of the egg is about 90 ohm cm. or 3.6 times that of sea water, and that the impedance of the surface of the egg is probably similar to that of a "polarization capacity". The characteristics of this surface impedance can best be determined by measurements of the capacity and resistance of suspensions of eggs. No specific change has been found in the interior resistance or the surface impedance which can be related either to membrane formation or to cell division.  相似文献   

16.
在两栖类,关于脊索对邻近组织的作用有大量的研究工作,但是,相反,关于邻近组织对脊索的影响过去几乎没有任何报道。因此,本工作企图通过外植的方法,研究脊索在早期发育是是如何决定的,是否也受邻近细胞的影响。结果发现,脊索的决定是一个渐进的过程,并提供了研究邻近组织影响的线索。  相似文献   

17.
童绍全 《植物研究》1998,18(2):137-143
据中国植物志(1981),云南有姜科植物17属, 78种,9变种。其后多篇文章论及一些种属,标本也有较多的增加。本文根据现有的标本与文献资料对云南姜科植物作增补与修订,共涉及16属15种,包括1个新种,7个修定后的异名。云南共计有姜科植物18属,148种和11变种。  相似文献   

18.
山茱萸果核抗氧作用研究   总被引:3,自引:0,他引:3  
用胡萝卜素漂白法初步探查到山茱萸果核的抗氧活性后,接着用烘箱试验法进一步证明它的水提物和甲醇提取物对市售豆油猪油也呈现明显抗氧作用,说明它有实际应用价值,从核甲醇提取物中分离鉴定了没食子酸及其中酯两种抗氧活性成分。  相似文献   

19.
苦荬菜属植物化学研究进展   总被引:6,自引:0,他引:6  
对近些年来发表的有关苦荬菜属的化学成分进行了综述,主要为倍半萜内酯类、三萜类成分。  相似文献   

20.
应用玉米秸秆栽培双孢蘑菇新技术   总被引:5,自引:0,他引:5  
梁枝荣  张清文  周志强  郭生   《微生物学通报》2000,27(6):443-445,457
首次报道在北方高寒地区用玉米秸秆做主料,利用简易菇棚夏季栽培双孢蘑菇的高产栽培技术. 试验研究和推广结果表明:利用成本低廉、易于建造的简易菇棚用于玉米秸秆生产双孢蘑菇,生物效率达 到了 48%,每平方米的产量达到了 9.6kg.  相似文献   

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