Direct Alloying of High Speed Steel M2 with CaWO_4 MoO_3 V_2O_5

The principle and possibility of alloying of high speed steel W6Mo5Cr4V2 (M2) with CaWO 4 MoO 3 V 2O 5 during the steelmaking are discussed, experiments of the alloying technologcial process have been carried out, the properties of M2 product have been determined, the benefit have been analysed. The results show that the rate of recovery of W Mo V are respectively 97.08%, 96.51%, 93.79% during the steelmaking of M2 alloying with CaWO 4 MoO 3 V 2O 5 in induction furnace, the chemical composition and properties of product M2 can meet the demands that the standard of high speed steel M2 requires.     

Azide Method Applied in the Synthesis of Antineoplastic Active Meterials-N''-Phenyacetyl-N-Substituted Glutamine

The results of studies of Antineopalston A10 show it's degradation products, such as glutamines and isoglutamines, having antitumor activity. According to these, some N'-phenylacetyl-N-substituted glutamines are designed and synthesized for researching their antitumor activity. In the syntheses of these compounds, the acid azides are prepared first, which then react with amines at low temperature to transform to the target molecules. The mild reaction conditions and good yields and the optical activity maintaining are the merits of this method. Evaluation of antitumor activity of the target molecules is carried out by MTT method to L1210 cell strain. The result showes some compounds can inhibit growth of the cancer cells.     

聚类分析在大豆“3414”试验设计中的应用

为了探讨大豆在"3414"试验设计下各个性状的关系以及对产量的影响,采用系统聚类的R型聚类法对‘安豆7号’在"3414"试验设计下的9个农艺性进行研究,采用中位数聚类法计算9个性状间的相关系数。结果表明:9个性状共划分为4个类,Ⅰ类为单株有效荚数、单株粒数、单株粒重、百粒重和产量,Ⅱ类为株高和主茎节数,Ⅲ类为有效分枝,Ⅳ类为底荚高度。剔除基因型对变量聚类的影响,明确了类间的典型指标,可为大豆品种的选育及性状相关研究提供参考。     

不同基因型大麦离体培养的花药及小孢子对低温和NaCl预处理的反应

以探讨大麦单倍体细胞水平的耐冷、耐NaCl性与植株水平抗病、耐盐性的相关性为目的，用赤霉病抗性、耐盐性不同的大麦为供试材料，比较了它们的离体培养花药及小孢子对低温、NaCl预处理的培养反应。结果表明：感病材料低温（5℃）预处理17d的花药培养愈伤组织诱导率比未经低温预处理的低，抗病材料则有一定的升幅。用NaCl溶液直接处理游离小孢子，所有供试材料的小孢子存活率随处理浓度升高不断下降，耐盐材料的存活率下降幅度比盐敏材料的小，且抗病材料的降幅比感病材料的小。说明：供体植株水平的抗病、耐盐性在花药、小孢子水平上也能有所表现。     

发酵法生产超氧化物歧化酶的研究进展

超氧化物歧化酶是一类广泛存在于生物体中的金属酶,在医药、食品和化妆品领域有较广泛的应用.通过介绍菌种选育、培养条件优化以及分离纯化方法,以提供该方面的研究新进展.     

海南普通野生稻琼海居群与三亚居群的遗传分化

普通野生稻(OryzarufipogonGriff.)是栽培稻的近缘祖先,蕴藏着丰富的优异基因,是宝贵的水稻遗传资源。普通野生稻主要分布在我国的南方地区,海南岛是我国普通野生稻的主要分布区之一,野生稻的遗传多样性曾经非常丰富。三亚是海南岛典型的热带地区,是普通野生稻主要的分布区。最近在海南琼海发现一个原生境普通野生稻居群,尚不清楚海南普通野生稻琼海居群与三亚居群之间的遗传关系。本研究采用37个SSR标记从SSR座位的多态率、SSR座位的基因杂合性、两居群间的遗传相似性和遗传距离以及两居群间的遗传分化等四方面,对海南普通野生稻琼海居群与三亚居群进行了遗传分析,旨在为海南普通野生稻的深入研究提供基础。结果表明SSR座位在两群体中存在较高的遗传变异,且其在普通野生稻三亚居群的遗传变异高于在普通野生稻琼海居群的遗传变异。SSR座位在琼海居群中的多态率为81.0811%,在三亚居群中的多态率为91.8919%;观察杂合性、理论杂合性、非偏性杂合性在三亚居群中的平均值为0.5651、0.4449、0.4661,高于在琼海居群中的相应平均值(0.4097、0.2057、0.2670)。根据Nei遗传相似性和遗传距离普通野生稻琼海居群与三亚居群间的遗传相似性为0.6385,遗传距离为0.4486。FST检验表明,两群体之间存在着中等程度的遗传分化(FST=0.3909),表明这两个普通野生稻居群内存在着60.91%的遗传变异。     

赤霉素和钙处理春小麦种子效应的研究

分段研究了GA和Ca~(2+)对种子成苗过程的吸涨、萌发和胚芽伸长3个阶段的影响。在吸涨阶段和萌发阶段,GA具有明显促进种子吸水和加快种子萌发的作用。Ca~(2+)则表现出抑制种子吸水和萌发。GA能够促进胚芽和芽鞘的伸长。Ca~(2+)则明显抑制了胚芽和芽鞘的伸长。GA促进成苗的主要因为它增大了种苗的导水性,从而加快了种苗吸收水分,由此促进了种子萌动、萌发和胚芽伸长。GA与Ca~(2+)混合后,Ca~(2+)抑制了GA对种子吸水、萌发和胚芽生长的促进作用,由此推断,干旱条件下Ca~(2+)对种子成苗的有利作用机理不同于GA。在干旱和半干旱地区,种子萌发和出土过程常常受到干旱的威胁,因此,加快种子萌发和出土对作物产量形成有着十分重要的意义。用植物激素、营养元素和其它化学药剂处理种子已有大量报道。有试验证明,一定浓度的GA有促进多种作物种子萌发和幼苗生长的作用。Ca~(2+)对种子萌发和幼苗生长的作用也有不少研究。我们的试验也证明,中度干旱条件下,GA和Ca~(2+)分别处理种子,确有促进根芽伸长、加快出苗速度和提高出苗率的作用(2)(3),并且提出用GA和Ca~(2+)混合处理种子,有互补作用。上述研究只是证明了GA和Ca~(2+)处理种子的作用效果对GA和Ca~(2+)的作用机理深入探讨不够,并且缺乏对GA和Ca~(2+)在种子吸涨—出土这一连续成苗过程的分段作用效果的研究。因此,本试验基于原有工作,对GA和Ca~(2+)在整个成苗过程各个阶段的作用效果和机制进行了初步探讨。     

Expression of inhibin/activin subunits in the ovaries of fetal and neonatal mice

In the present study, the expression of inhibin/activin subunits in the mouse ovary from 13 days post-coitus (dpc) to 30 days postpartum (dpp) was investigated. Circulating FSH, LH, inhibin A, and inhibin B in neonatal to 30 dpp ovaries were measured. Inhibin/activin subunits (alpha, beta(A), beta(B) ) were weakly stained in 13 dpc ovarian stromal cells and increased with age. Inhibin alpha subunit was immunolocalized in follicular granulosa cells at each developmental stage. In 30 dpp ovaries, several large antral follicles were strongly stained for inhibin alpha subunit. Inhibin beta(A) subunit was weakly immunolocalized in granulosa cells until 20 dpp. Moreover, 2 to 3 antral follicles from 20 to 30 dpp were strongly stained for inhibin beta(A) subunit. There was relatively high immunoactivity for inhibin beta(B) subunit in neonatal to 30 dpp mouse ovaries. All three inhibin subunits were stained in theca-interstitial cells from 15 dpp onward. RIA data showed that a temporal increase in circulating FSH occurred around 10 dpp, while the plasma concentrations of LH were sustained at a relatively higher level from 8 to 15 dpp. Inhibin B was detectable in circulation early at 1 dpp (day of birth), and a clear increase in inhibin B occurred around 8 dpp. Circulating inhibin B gradually increased from 20 dpp to 30 dpp, indicating a negative correlation with FSH. Inhibin A levels were only measured on 25 and 30 dpp, and the levels were low. These results suggest that inhibins play an important role in early folliculogenesis in mice. In addition, inhibin B seems to be the main functional isoform from the neonatal to prepubertal stage in the mouse ovary.     

Effects of extraction solvent mixtures on antioxidant activity evaluation and their extraction capacity and selectivity for free phenolic compounds in barley (Hordeum vulgare L.)

Four kinds of solvent extracts from three Chinese barley varieties (Ken-3, KA4B, and Gan-3) were used to examine the effects of extraction solvent mixtures on antioxidant activity evaluation and their extraction capacity and selectivity for free phenolic compounds in barley through free radical scavenging activity, reducing power and metal chelating activity, and individual and total phenolic contents. Results showed that extraction solvent mixtures had significant impacts on antioxidant activity estimation, as well as different extraction capacity and selectivity for free phenolic compounds in barley. The highest DPPH* and ABTS*+ scavenging activities and reducing power were found in 80% acetone extracts, whereas the strongest *OH scavenging activity, O2*- scavenging activity, and metal chelating activity were found in 80% ethanol, 80% methanol, and water extracts, respectively. Additionally, 80% acetone showed the highest extraction capacity for (+)-catechin and ferulic, caffeic, vanillic, and p-coumaric acids, 80% methanol for (-)-epicatechin and syringic acid, and water for protocatechuic and gallic acids. Furthermore, correlations analysis revealed that TPC, reducing power, DPPH* and ABTS*+ scavenging activities were well positively correlated with each other (p < 0.01). Thus, for routine screening of barley varieties with higher antioxidant activity, 80% acetone was recommended to extract free phenolic compounds from barley. DPPH* scavenging activity and ABTS*+ scavenging activity or reducing power could be used to assess barley antioxidant activity.     

Extensive analysis of different allelelic structures of the chicken BF2 and beta2m proteins

No information is available to date on the different allelelic structures of the chicken MHC class I (BF2) and beta2m proteins. To elucidate the structure, new allelic beta2m and five different BF2 genes were expressed solubly and purified in a pMAL-p2X/E. coli TB1 system. The 2D structure was detected by circular dichroism (CD) spectroscopy, and the 3D structures of their peptide-binding domain (PBD) were analyzed by homology modeling. The sequence lengths of the alpha-helix, beta-sheet, turn, and random coil in the five BF2 proteins were 69-73 aa, 67-72 aa, 35-37 aa, and 94-98 aa, respectively. The new beta2m protein displayed a typical beta-sheet. Homology modeling of the different BF2 and beta2m proteins demonstrated similarities to the structure of human and rat MHC class I proteins. The 3D structure, however, revealed that the BF2 and beta2m structures were unique. The correct refolding of recombinant BF2 and beta2m proteins might be a powerful tool to further detect antigenic peptides.