助手标题  
全文文献 工具书 数字 学术定义 翻译助手 学术趋势 更多
查询帮助
意见反馈
   precursor 在 生物学 分类中 的翻译结果: 查询用时:0.207秒
图标索引 在分类学科中查询
所有学科
生物学
材料科学
无机化工
地质学
地球物理学
化学
有机化工
精神病学
工业通用技术及设备
更多类别查询

图标索引 历史查询
 

precursor
相关语句
  前体
    DISTRIBUTION OF GNRH-ASSOCIATED PEPTIDE OF GNRH PRECURSOR MOLECULE IN RAT PITUITARY AND TESTIS
    GnRH前体分子中的GnRH相关肽在大鼠垂体和睾丸的分布
短句来源
    Effects of Ethylene Precursor ACC on Differentiation of Leaf Explants in Lycopersicon esculentum
    乙烯前体ACC对番茄叶外植体分化的影响(简报)
短句来源
    Mutation and Selection of Resistant Precursor of Griseofulvin Producing Strain F-1012 and Its Fermentation
    灰黄霉素产生菌耐前体变株F-1012的选育及其发酵特性
短句来源
    Cloning of a Gene Encoding the Precursor of Nisin by PCR
    利用PCR技术克隆乳链菌肽前体基因
短句来源
    THE EFFECT OF IL-1 ON β AMYLOID PRECURSOR PROTEIN GENE EXPRESSION IN RAT BRAIN
    IL-1对大鼠脑组织β淀粉样前体蛋白基因表达的影响
短句来源
更多       
  “precursor”译为未确定词的双语例句
    NisP Is Related to Nisin Precursor Processing and Possibly to Immunity in Lactococcus Lactis
    NisP Is Related to Nisin Precursor Processing and Possibly to Immunity in Lactococcus Lactis
短句来源
    Methods:RT-PCR was used to amplify rat GAP-43 gene from RNA of rat oligodendrocyte precursor cells(OPCs).
    方法:采用RT-PCR方法,以大鼠少突胶质前体细胞RNA为模板,扩增GAP-43基因,定向克隆到pEGFP-N3载体中。
短句来源
    The nucleotides sequence homology and putative amino acid sequence homology of the gene fragment were 99%,compared with Bacillus amyloliquefaciens subtilisin DFE precursor and Bacillus sp.DJ-4,respectively.
    该基因片段核苷酸序列与Bacillus amyloliquefaciens subtilisin DFE precursor有99%的同源性,对应的氨基酸序列与Bacillussp. DJ-4有99%的同源性。
短句来源
    Improvement of Mingle Strains in the Fermentation of 2 Keto L Gulonic Acid——Precursor of Vc by Ion Implantation
    离子注入改良维生素C二步发酵混合菌研究(Ⅰ)2-酮基-L-古龙酸高产菌系IPPM-1028的选育
短句来源
    Prediction of epitopes on HFRSV nucleocapsid protein and M polyprotein precursor restricted by H 2 d and H 2 b class Ⅰ molecules
    H-2~b和H-2~d单体型小鼠MHCI类分子结合的HFRSV蛋白抗原表位的预测
短句来源
更多       
查询“precursor”译词为用户自定义的双语例句

    我想查看译文中含有:的双语例句
例句
为了更好的帮助您理解掌握查询词或其译词在地道英语中的实际用法,我们为您准备了出自英文原文的大量英语例句,供您参考。
  precursor
The overall process involves three steps: preparation of insoluble carboxyl-containing grafted starch copolymer (ISC), formation of precursor (ISC-Co), decomposition of ISC-Co, and phase transition of Co3O4 nanoparticles.
      
The precursor was proved to be [Zn5(OH)6(CO3)2] by TG-DTG-DTA and IR analysis.
      
This precursor was calcined at 300°C for 1, 2 and 3 hours respectively, and then the nanocrystalline ZnO of different grain size were obtained.
      
Steam produced during the decomposition process accelerated the sintering of MgO, and MgO with surface area as high as 412 m2 · g-1 was obtained through calcining its precursor in flowing dry nitrogen at 520°C for 4 h.
      
ZrWMoO8 powders with different morphologies were obtained using ammonium tungstate, molybdate tungstate and zirconium tungstate as the starting materials by dehydrating the precursor ZrWMoO7(OH)2(H2O)2.
      
更多          


(1) In studying the quantum efficiencies of photophosphorylation and of the Hill reaction, it was found that at low light intensities the quantum efficiencies of photophosphorylation(either"cyclic" with PMS or vitamin K as cofactors or coupled with Fe(CN)_6≡reduction) were abnormally low, whereas that of the simultaneously measured Hill reaction remains constant(Tab. 1). This unusual"light intensity effect" is evidently not related to the election transport chain, but is only concerned with the mechanism of...

(1) In studying the quantum efficiencies of photophosphorylation and of the Hill reaction, it was found that at low light intensities the quantum efficiencies of photophosphorylation(either"cyclic" with PMS or vitamin K as cofactors or coupled with Fe(CN)_6≡reduction) were abnormally low, whereas that of the simultaneously measured Hill reaction remains constant(Tab. 1). This unusual"light intensity effect" is evidently not related to the election transport chain, but is only concerned with the mechanism of ATP production.The addition of large amounts of non-radioactive ATP to the reaction mixture(Tab. 2) or the previous formation of some AT~(32)P by preillumination(Tab. 3) does not attenuate this"light intensity effect". It is therefore not due to the decomposition of the final reaction product, ATP, nor an artifact introduced by the use of the radioactive method of AT~(32)P determination, and consequently must be concerned with the intermediate steps of phosphorylation.(2) By increasing the intensity of illumination, this unusual"light intensity effect" gradually disappears and the rate of photophosphorylation becomes proportional to light energy(Tab. 4). At a lower temperature(5℃), it is less pronounced. When weak light is given in short flashes interposed with dark intervals instead of continuously, the production of ATP is greatly lowered or completely obliterated(Tab. 5). All these results serve to show that the"light intensity effect" is due to a dark, thermal reaction by which some intermediate(s) in the phosphorylation path is destroyed or side-tracked.The reaction is probably enzymic in nature as evidenced by its rate order and its response to temperature. That the"light intensity effect" becomes insignificant at higher light intensities, indicates that the amount of the enzyme is limited and easily saturated so as to be negligible when the concentration of the photophosphorylation intermediate(s) is high, i.e., under strong illumination. That flashing light with short dark periods can completely abolish ATP formation means that this enzyme has a high affinity for the intermediate.(3) By illuminating chloroplasts with Mg~(++) and PMS then adding immediately to Pi and ADP in the dark, ATP can still be formed. But if the illuminated suspension is allowed to stand in darkness for 5 seconds before adding Pi and ADP, no ATP can be detected(Tab. 7). There is, therefore, an intermediate(Z~*) formed in light which can react with Pi and ADP in darkness (Fig. 1). At saturating intensities, this intermediate shows a concentration of 20-40 mμmole/μmole chlorophyll, i.e., in molecular rates of 1:25-50. At room temperature, this intermediate quickly dissipates(Tab. 7 and Tab. 8), but it becomes more stable as the incubating temperature is lowered to 5℃(Tab. 8).(4) By illuminating a similar suspension in presence of Pi and letting it stand in darkness for 5 sec. before adding ADP, the ATP formed is about 1/2 of that obtained by the immediate addition of ADP (Tab. 7). This shows that a second intermediate is formed with P/ (Z~P) and subsequently reacts with ADP. Apparently, in the chloroplast, the second intermediate is more stable than the first one(Z~*).(5) From the above results, it is concluded that the"light intensity effect" of photophosphorylation is probably due to the destruction or removal of intermediates in the phosphorylation mechanism. At least 2 such intermediates are indicated, the one before the participation of Pi is less stable, and it(or its precursor) is therefore mainly responsible for the said effect. The relation of the proposed scheme to the results of other workers and in comparison with oxidative phosphorylation is discussed.

(1)在不同光强度下研究叶綠体的光合磷酸化作用和希尔反应,发现当光弱到一定程度后,光合磷酸化的效率,不论是“循环”或是“偶联”的都显著降低,而同时测定的希尔反应的效率则不变。因此,这个“光强效应”为光合磷酸化所特有,显然不是发生在“电子传递系统”或氧化还原部分。(2)在作用液中加入非放射性的ATP或预先照光形成一些AT~32P,再进行实验,这个“光强效应”仍同样出现,证明这个效应不是由于最终产物(ATP)的分解,亦不是由于应用放射性~(32)P测定方法所造成的假象。(3)这个“光强效应”在光强增加到一定程度以上时,即逐渐消失;在较低的温度下则减轻;在闪光条件下则比在连续光下更加显著。这些结果指出,“光强效应”是由于中间产物的破坏或转向其他代谢途径。此作用是一个暗反应,可能是酶促的。酶量少,容易达到饱和,弱光下中间产物少,被它作用的比重就大,强光下中间产物多,被它作用的比重就小,所以“光强效应”只在弱光下显著。(4) 叶綠体加Mg~(++)及PMS照以饱和强光,然后立即(<0.1秒)在暗中加入Pi及ADP,仍有很多ATP形成,但如在暗中过5秒钟后再加Pi及ADP,则几乎完全没有ATP形成。这指出叶綠体照光后产生...

(1)在不同光强度下研究叶綠体的光合磷酸化作用和希尔反应,发现当光弱到一定程度后,光合磷酸化的效率,不论是“循环”或是“偶联”的都显著降低,而同时测定的希尔反应的效率则不变。因此,这个“光强效应”为光合磷酸化所特有,显然不是发生在“电子传递系统”或氧化还原部分。(2)在作用液中加入非放射性的ATP或预先照光形成一些AT~32P,再进行实验,这个“光强效应”仍同样出现,证明这个效应不是由于最终产物(ATP)的分解,亦不是由于应用放射性~(32)P测定方法所造成的假象。(3)这个“光强效应”在光强增加到一定程度以上时,即逐渐消失;在较低的温度下则减轻;在闪光条件下则比在连续光下更加显著。这些结果指出,“光强效应”是由于中间产物的破坏或转向其他代谢途径。此作用是一个暗反应,可能是酶促的。酶量少,容易达到饱和,弱光下中间产物少,被它作用的比重就大,强光下中间产物多,被它作用的比重就小,所以“光强效应”只在弱光下显著。(4) 叶綠体加Mg~(++)及PMS照以饱和强光,然后立即(<0.1秒)在暗中加入Pi及ADP,仍有很多ATP形成,但如在暗中过5秒钟后再加Pi及ADP,则几乎完全没有ATP形成。这指出叶綠体照光后产生能与Pi结合的中间产物(Z~*),其饱和量约为20—40mμmole/μmole叶綠素。它在室温(20—25度)迅速破坏或转向其他代谢途径,5秒后已不存在,在低温(5度)则可维持数秒。(5) 同样制剂加Pi再照光,然后暗5秒再加ADP,则ATP的产量,比立即加ADP者只减少一半。指出上述的中间产物(Z~*)与Pi结合后形成第二个中间产物(Z~P)在叶綠体内比较稳定。“光强效应”可能主要是Z~*或以前的中间产物被破坏或转向其他用途所引起。

This paper deals with the distribution of phenolic substances and phenolase in Schistosoma japonicum, with special reference to the various techniques used for histochemical demonstration of phenolase in sehistosomes. Both sehistosomula and adult worms were used for the present study. Phenolic substances were detected by means of several methods, including Diazonium salts reaction, Gomori's methenamine silver reaction, Indophenol reaction, Gibbs' reaction, Sehmorl's ferric-ferriecyanide reaction and chromaffin...

This paper deals with the distribution of phenolic substances and phenolase in Schistosoma japonicum, with special reference to the various techniques used for histochemical demonstration of phenolase in sehistosomes. Both sehistosomula and adult worms were used for the present study. Phenolic substances were detected by means of several methods, including Diazonium salts reaction, Gomori's methenamine silver reaction, Indophenol reaction, Gibbs' reaction, Sehmorl's ferric-ferriecyanide reaction and chromaffin reaction. Phenolase was demonstrated by incubating fresh worms in pH 6.7 or 7.7 phosphate buffer containing substrates of 3mM p-Cresol, Tyramine, o-Catechol and L-Tyrosine etc at 37℃ for 1/2-3 hours. The location of the enzyme was indicated by the development of reddish brown colour. Controls for phenols and phenolase were made by the benzoylation and the inhibition with sodium diethyldithiocarbamate respectively.The results obtained from the experiments using different substrates showed that they could be oxidized only by the mature female worms. The data revealed that the enzyme quickly oxidized both p-Cresol and tyramine within half an hour, while it reacted with o-Catechol in about one hour; but with L-Tyrosine or 3,4-dihydroxy-phenylalanine the reaction required 18 hours. The enzyme exhibited greater activity at pH 7.7 than at 6.7. Results obtained from both sectioned and in toio mount specimens indicated that the phenols and phenolase were localized only in the globules of the mature vitelline cells and in the shells of in utero eggs of the mature females. No other part in the sections showed any positive reactions by these methods. Neither the sehistosomula nor the male worms indicated the presence of phenol and phenolase. Taking into consideration of our previous studies on the protein histochemistry of the vitelline cells of this fluke, the authors are of the opinion that the nature of the precursor and the chemistry of egg-shell in S. japonicum might be a quinone-tanned protein system.The histochemistry of phenolase in Trematoda was briefly discussed and compared.

本文对不同发育阶段的日本血吸虫体内的酚类物质及酚酶的分布进行了研究,并介绍了一种显示日本血吸虫酚酶的组织化学方法。研究的结果表明:仅成熟雌虫的卵黄细胞颗粒球及子宫中虫卵卵壳含有酚类物质及酚酶,雌虫的其它组织细胞,雄虫的所有组织 细胞以及未成熟的雌性或雄性童虫均无酚类物质及酚酶。雌性血吸虫体内的酚类物质及酚酶的生理意义是作为制造卵壳的前身物质;推想在卵壳形成过程中,酚类物质被酚酶氧化成醌,再与邻近的蛋白质结合形成醌鞣蛋白,成为硬化的卵壳物质。本文还对吸虫纲中酚酶组织化学的问题进行了比较和讨论。

It is well known that the paired blood flukes Schistosoma japonieum, living in human's portal-mesenterie veins, copulate more or less permanently and lay their eggs in large numbers. The eggs are partly passed via the feces to form transmissive agents; the others are deposited in the host tissues to bring about granulomatous lesions. Thus schistosome eggs are not only the main factor of pathogenesis, but also an important source in transmission of the disease. The problems on the egg formation and shell-formative...

It is well known that the paired blood flukes Schistosoma japonieum, living in human's portal-mesenterie veins, copulate more or less permanently and lay their eggs in large numbers. The eggs are partly passed via the feces to form transmissive agents; the others are deposited in the host tissues to bring about granulomatous lesions. Thus schistosome eggs are not only the main factor of pathogenesis, but also an important source in transmission of the disease. The problems on the egg formation and shell-formative substances in s玥istosome, therefore, have been receiving an increasing attention in recent years. The present paper deals with the process of egg formation of 8. japonieum and the chemical nature of the egg shell by means of his-tologieal and histoehemical technique, as well as some results of the effects of thiourea compounds on the egg formation in this fluke.In the case of micro-anatomy, histology and histochemistry of female genitalia, it was shown that the female reproductive system consisted of an ovary, vitelline gland, oviduct, vitelline tube, ovovitelline tube, ootype. Mentis' gland, uterus and genital pore. A large ovoid ovary was situated a little posterior to the middle of the body. At the base of the ovary, an ovarian ampulla was observed and its opening was surrounded by a group of circular sphincter muscles which probably regulated the passage of maturing ova into the oviduct. The proximal part of the oviduct was enlarged to form a chamber of large diameter, which was invariably filled with spermatozoa. Ova emerged from the ovarian ampulla met with sperms at this region and fertilization took place, so the chamber served practically as a seminal receptacle. Connecting with the chamber was a very small tube which wound and ran anteriorly to the ovovitelline tube, where it joined the vitelline tube. The positive reaction for nuelic acids, aromatic amino-acids, phosphatase and some glycogen was found in the maturing ova.The vitelline gland consisted of a large number of lobules extending through the body posterior to the ovary and each lobule contained cells at different stages of development. The mature vitelline cell was a large conspicious cell characterized by the granules concentrated mainly at the periphery of the cell. Basic proteins, phenolic substances and phenolase were richly distributed in these granules. The other obvious feature was a great deal of lipid droplets scattered through the cytoplasm, while glycogen could not be detected.Valve-like structures containing 2 or 3 nuclei might be observed from the following locations of the associated ducts: one at the joint of ovarian ampulla to the proximal oviduct; one at the junction of the posterior oviduct with the vitelline tube; one in the lumen of the terminal part of the vitelline tube near to the ovovitelline tube as well as in the lumen of the ovovitelline tube. Their respective role and functions were discussed.The epithelial cells of the ootype were shown to be apocrine secretion glandular cells with a rhythmic function probably connected with the formation of eggs. These cells might be divided into two phases, one being the resting phase and the other secreting phase. Alkaline phosphatase activity and aromatic amino-acids were most pronounced in these epithelial cells. The entrance of the ootype into the uterus proper was guarded by a well-defined valve which regulated their passage and prevented reflex.Mehlis' gland consisted of a group of one type unicellular gland cells lying in the parenchyma adjacent to the ootype and opening into the lumen of pre-chamber of the ootype. According to the tests for histochemistry, it was found that their secretions were strongly positive with the PAS reaction even after diastase or hya-luronidase treatment. The secretions from Mehlis' gland cells and/or epithelial cells of ootype played a vital part in coalescence of the vitellogranules and the formation of the egg shell.In the case of histochemical tests for egg shell precursors in S. japonicum, a number of methods were employed to ascertain t

本文应用组织学及组织化学方法研究了日本血吸虫卵形成的过程,并进行了硫脲化合物对虫卵形成影响的实验。 日本血吸虫雌虫生殖系统是由发生卵细胞的卵巢和发生卵黄细胞的卵黄腺这两个腺体及其连接管道所组成。连接管道包括输卵管、卵黄管和卵-卵黄会合管,分别将卵细胞和卵黄细胞运送至卵形成部位——卵模及其周围的梅氏腺,在其中形成一个完整的虫卵,再通过子官将此新形成的虫卵送经生殖孔而排出。 一个完整的虫卵系由一个受精卵细胞,及约20个卵黄细胞以及包在它们外面的一种硬化蛋白质的卵壳所构成。卵细胞含有丰富的核糖核酸、去氧核糖核酸、芳香族氨基酸、磷酸酶和若干糖原。卵黄细胞含有许多脂类物质,其细胞质中的卵黄颗粒球是制造卵壳的原料,含有蛋白质、酚类物质和酸酶,它们是卵壳的前身物。卵壳形成的化学性质可能是酚类物质受酚酶的氧化作用变成醌,再与邻近的蛋白质结合成醌鞣蛋白,而成为一种硬化的卵壳物质。 日本血吸虫卵形成部位系在雌虫体中段的卵模及梅氏腺区域。卵模腔内壁由单层上皮细胞所构成,它是一种顶浆分泌腺细胞,含有丰富的碱性磷酸酶和芳香族氨基酸蛋白质。在形态上可分为静止相和分泌相,它的分泌机能呈现周期性并似与卵模腔内卵壳的形成有节奏地相配合。在卵模...

本文应用组织学及组织化学方法研究了日本血吸虫卵形成的过程,并进行了硫脲化合物对虫卵形成影响的实验。 日本血吸虫雌虫生殖系统是由发生卵细胞的卵巢和发生卵黄细胞的卵黄腺这两个腺体及其连接管道所组成。连接管道包括输卵管、卵黄管和卵-卵黄会合管,分别将卵细胞和卵黄细胞运送至卵形成部位——卵模及其周围的梅氏腺,在其中形成一个完整的虫卵,再通过子官将此新形成的虫卵送经生殖孔而排出。 一个完整的虫卵系由一个受精卵细胞,及约20个卵黄细胞以及包在它们外面的一种硬化蛋白质的卵壳所构成。卵细胞含有丰富的核糖核酸、去氧核糖核酸、芳香族氨基酸、磷酸酶和若干糖原。卵黄细胞含有许多脂类物质,其细胞质中的卵黄颗粒球是制造卵壳的原料,含有蛋白质、酚类物质和酸酶,它们是卵壳的前身物。卵壳形成的化学性质可能是酚类物质受酚酶的氧化作用变成醌,再与邻近的蛋白质结合成醌鞣蛋白,而成为一种硬化的卵壳物质。 日本血吸虫卵形成部位系在雌虫体中段的卵模及梅氏腺区域。卵模腔内壁由单层上皮细胞所构成,它是一种顶浆分泌腺细胞,含有丰富的碱性磷酸酶和芳香族氨基酸蛋白质。在形态上可分为静止相和分泌相,它的分泌机能呈现周期性并似与卵模腔内卵壳的形成有节奏地相配合。在卵模周围分布着一种单细

 
<< 更多相关文摘    
图标索引 相关查询

 


 
CNKI小工具
在英文学术搜索中查有关precursor的内容
在知识搜索中查有关precursor的内容
在数字搜索中查有关precursor的内容
在概念知识元中查有关precursor的内容
在学术趋势中查有关precursor的内容
 
 

CNKI主页设CNKI翻译助手为主页 | 收藏CNKI翻译助手 | 广告服务 | 英文学术搜索
版权图标  2008 CNKI-中国知网
京ICP证040431号 互联网出版许可证 新出网证(京)字008号
北京市公安局海淀分局 备案号:110 1081725
版权图标 2008中国知网(cnki) 中国学术期刊(光盘版)电子杂志社