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951.
大鼠骨骼肌多催化功能蛋白酶的提取、鉴定及其抗血清的制备 总被引:1,自引:0,他引:1
为了研究多催化功能蛋白酶(multicatalyticalproteinase,MCP)在负氮平衡形成中的作用,以大鼠骨骼肌为原料,提取此酶并制备其抗血清.将大鼠骨骼肌粗提物经45%~65%饱和度硫酸铵分级盐析、阴离子交换层析和凝胶过滤,最后从Sepharose4B层析柱上获得单一活性洗脱峰.酶活性用Carbobenzoxy-Val-Gly-Arg-4-nitrinilideacetate作底物检测.非变性PAGE银盐染色显示单一区带的骨骼肌多催化功能蛋白酶,SDS-PAGE银盐染色显示10条亚基电泳区带,分子量在25~32kD之间.纯化的酶免疫兔8周后,抗血清效价达132,用分级盐析和离子交换层析纯化抗血清,显示单一电泳区带的IgG.Western-blot分析显示只在25~32kD之间出现多条亚基区带.这些结果提示已获得电泳纯MCP及其较高特异性的多克隆抗体. 相似文献
952.
烟蚜在烟株上的垂直分布及其分布型 总被引:5,自引:0,他引:5
在烤烟K-326团棵期烟株上,Ⅰ-Ⅲ龄若蚜,Ⅳ龄若蚜+无翅成蚜在各叶位间的分布量具有显著差异,且这种差异与烟株上国蚜Myzusnicotianae(Blackman)的密度有关。 相似文献
953.
血管内皮细胞和血管平滑肌细胞在结构和功能上关系密切,二者的相互关系在血管舒缩和血管壁结构的调节中起重要作用。本文观察了培养的小牛肺动脉内皮细胞(PAEC)和肺动脉平滑肌细胞(PASM)在细胞增殖方面的相互调节作用。混合培养的PAEC和PASM细胞的3H-TdR参入明显降低(P<0.001,与对照组相比)。无论向培养的PAEC和PASM中分别加入PASM和PAEC的条件培养基还是二者共培养时,均发现PAEC的3H-TdR参入明显降低,而PASM的3H-TdR明显升高(P<0.05,与对照组相比)。流式细胞测定也发现共培养时PAEC的G1期细胞增多,G2/M期细胞减少;而PASM的G1期细胞减少,G2/M期细胞增多。共培养的PASM细胞内cAMP增加,cGMP含量降低;而PAEC细胞的cAMP和cGMP含量均降低(P<0.01,与对照组相比)。上述结果提示,PAEC和PASM相互作用可能通过第二信使而调节它们本身的增殖 相似文献
954.
Ji Tianyi Chen Minhao Sun Weiwei Zhang Xiao Cai Hao Wang Youhua Xu Hua 《Journal of molecular histology》2022,53(4):635-643
Journal of Molecular Histology - Aging is a major risk factor for degenerative joint diseases, such as osteoarthritis (OA). Previous studies have confirmed the link between senescent mesenchymal... 相似文献
955.
956.
Jian‐Wen Zhang David E. Boufford Hang Sun 《Botanical journal of the Linnean Society. Linnean Society of London》2013,173(3):476-486
The systematic significance of the morphological structure of achenes in the Himalayan–Tibetan Plateau endemic genera Soroseris, Syncalathium and Parasyncalathium is described and discussed. The achene surface sculpturing of 15 samples representing 13 species of the three genera was investigated using scanning electronic microscopy (SEM) to evaluate inter‐ and intrageneric relationships of the three genera. Characters such as cell arrangement, shape of the epidermis, type of ornamentation of the outer cell wall and degree of wax development are described. The results show that characters such as the shape of the epidermis and the type of ornamentation of the outer cell wall are distinct between the three genera and useful for species‐level classification. Parasyncalathium souliei differs from Syncalathium, in which it has traditionally been placed, in the short, stout beak of the achene and especially in the obscure outline of the epidermal cells and their long acuminate, steeple‐like, end walls. Combined with karyological and molecular data, the differences in achene morphology and sculpturing further support our recognition of Parasyncalathium as distinct from Syncalathium. The achene characters are not only useful for assessing relationships, but are also useful for delimiting species. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, 173 , 476–486. 相似文献
957.
Deletion and mutation of phosphatase and tensin homolog deleted on chromosome10 (PTEN) are closely associated with the occurrence of tumors. Tumor suppressor gene PTEN mutation plays an important role in the pathogenesis of ovarian cancer. However, it has been unclear whether it can regulate the senescence of ovarian cancer cells. We speculated that PTEN might inhibit the occurrence and development of ovarian cancer by promoting the expression of P21. We found that the expression of TRIM39 in human ovarian cancer was significantly diminished. In SKOV3 cells treated with naringin, the expression of TRIM39, which binds P21 and inhibits P21 degradation, was significantly elevated. Real-time polymerase chain reaction (PCR), Western blot, and immunofluorescence were used to detected the expression of PTEN, p21, and TRIM39, β-galactosidase Staining was used to detect cell senescence, Ki67 staining was used to observe cell proliferation, Trim39 interference or overexpression assay was used to detect its function. We speculated that PTEN might promote SKOV3 cell senescence by increasing TRIM39 expression and decreasing P21 degradation. Furthermore, by interfering with TRIM39 in SKOV3 cells, we found that the expression of P21 was downregulated, and the number of senescent SKOV3 cells decreased. With overexpression of TRIM39 in SKOV3 cells, the expression of P21 was upregulated, and the number of senescent SKOV3 cells increased. When naringin, a PTEN agonist, was added to SKOV3 cells in which TRIM39 protein was interfered with, the expression of P21 was significantly lower than that in the control group, and the number of senescent ovarian cancer cells was significantly diminished. Our results indicated that PTEN maintained the stability of P21 and decreased the degradation of P21 by increasing TRIM39 expression, thus promoting the senescence of SKOV3 cells, and PTEN maintained the stability of p21 and promoted the aging of SKOV3 cells might be a novel therapeutic target for ovarian cancer. 相似文献
958.
缙云山4种林分土壤无机磷与活性铝的含量及分布 总被引:1,自引:0,他引:1
为探索不同林分对土壤中无机磷与活性铝的含量及分布的影响,以及无机磷与活性铝之间的相互关系,以在我国西南地区酸性土壤上的农林经营管理提供理论和实践依据。研究以缙云山广泛分布的4种林分类型:山莓、马尾松、楠竹和柑橘林土壤为对象,采用酸性土壤无机磷分级方法和铝试剂比色法测定了土壤剖面A、B和C层中各形态的无机磷与活性铝的含量,分析了不同林分土壤中无机磷和活性铝的含量和分布特征。结果表明,林分类型显著影响土壤中无机磷与活性铝的含量与分布,且铁磷(Fe-P)、交换态铝(Ex-Al)和羟基铝(Hy-Al)的含量和比例还受到土壤层次的影响。4种林分相比,山莓林能促进闭蓄态磷(O-P)的形成,而马尾松、楠竹和柑橘林则有利于Al-P、Fe-P和Ca-P的形成;柑橘林有利于低活性的腐殖酸铝(Al-AH)形成,而山莓、马尾松和楠竹林促进高活性的Ex-Al或Hy-Al溶出;Ex-Al、Al-P和Fe-P在土层的分布上有表层富集现象,而Hy-Al集中分布于B层。此外,土壤Ex-Al和Al-P与Fe-P之间,Hy-Al和Ca-P之间均呈显著(P<0.05)正相关。因此,林分类型显著影响土壤无机磷与活性铝的含... 相似文献
959.
冀北承德地区土壤生源要素生态化学计量与空间分异特征 总被引:2,自引:0,他引:2
土壤生源要素生态化学计量和空间分异特征对指导土地利用优化具有重要意义。以京津冀生态屏障区组成部分的承德市为研究区,采集1597件土壤样品,运用地统计学、全局Moran′s I指数、克里金插值和冗余分析等方法对承德全域主要土壤生源要素的空间分异特征及其影响因素进行了系统分析。结果表明,承德市表层土壤生源要素全钾(STK)、有机碳(SOC)、全氮(STN)、全磷(STP)和全硫(STS)平均含量分别为21.962 g/kg、18.826 g/kg、1.168 g/kg、0.587 g/kg和0.193 g/kg。垂向分布上STN、SOC和STS含量总体随深度增加而降低,STK和STP垂向分异受成土母质控制,高地质背景区STK和STP含量随深度增加逐渐升高。SOC和STN含量显著相关,空间耦合程度高,C:S与SOC含量显著正相关,C:N和C:S空间分布稳定,土壤生源要素的化学计量比主要受SOC含量控制。SOC空间自相关极显著,空间分异受结构性因素控制;STK空间自相关程度较高,分布稳定;STP空间自相关较显著,分布异质性较大;STS空间自相关相对最弱,受人为活动影响较明显。SOC和STN空间... 相似文献
960.
In maize, the P1-vv allele specifies variegated pericarp and cob pigmentation, and contains an Ac transposable element inserted in the second intron of the P1-rr gene. Starting from P1-vv, we recovered a new allele, called P1-vv5145, which gives an extremely light variegated pericarp and cob phenotype. The P1-vv5145 allele contains an Ac element ( Ac5145) at the same position and in the same orientation as in the progenitor P1-vv allele; however, the P1-vv5145 allele has a 2-bp deletion which removes the last nucleotide (A) from the 3' end of the Ac element, and an adjacent flanking nucleotide (C) from the p1 intron. In crosses with a Ds tester stock, P1-vv5145 shows a normal ability to induce Ds transposition; however, Ac excision from P1-vv5145 is 3800-fold less frequent than from the progenitor P1-vv allele. Our results demonstrate that the alteration of the 3' terminal base strongly impairs Ac transposition. The P1-vv5145 allele thus provides a relatively stable source of Ac transposase for controlling Ds transposition in genetic experiments. In addition, we describe two further alleles ( P1-ww7B8, P1-ww9A146-3) that contain deletions of Ac and flanking p1 gene sequences. These latter deletions are larger and involve the 5' end of the the Ac element. A model is proposed to explain the formation of one-sided deletions as a consequence of Ac transposition during replication of the element. 相似文献