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71.
Using various transformation methods, T-DNA constructions for insertional mutagenesis were introduced into Arabidopsis thaliana and the pattern of segregation of hygromycin resistance selectable marker was followed in succeeding generations in individual transgenic lines up to T4 generation. Despite the low frequency of transformation, T-DNA was often inserted in two or more independent sites. Mendelian segregation ratios 3:1, 15:1, and irregular segregation ratios were observed. We have also shown continuous decrease of the expression of the resident hygromycin resistance transgenic trait in some lines. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
72.
Sobue  Gen  Yamamoto  Masahiko  Doyu  Manabu  Li  Mei  Yasuda  Takeshi  Mitsuma  Terunori 《Neurochemical research》1998,23(6):821-829
The steady-state mRNA levels of NGF, BDNF and NT-3, and the mRNA levels of their receptors p75NGFR, trk, trk,B and trkC were examined in various human peripheral neuropathies, to determine the correlation with myelinated fiber pathology and T cell and macrophage invasions in the diseased nerves. Steady state levels of p75NGFR mRNAs were significantly elevated in nerves with axonal pathology. In contrast, steady state levels of trkB and trkC mRNA levels were diminished, trk mRNA was not detected in the human nerves. The NGF, BDNF, and NT-3 mRNA levels were elevated in the diseased nerves. The increase in BDNF and NT-3 mRNA levels were proportional to the extent of invasion of the nerves by T cells and macrophages, but did not directly correlate with axonal nor demyelinating pathology, thus suggesting that inflammatory cell invasions are involved in the regulation of BDNF and NT-3 mRNA expressions. These neurotrophin and their receptor gene expressions in the diseased human nerves would be regulated by an underlying pathology-related process, and could play a role in peripheral nerve repair.  相似文献   
73.
Abstract In the wheatbelt region of Western Australia, brush-tailed bettongs or woylies, Bettongia penicillata, occur in remnant woodlands that have highly water repellent soils. As these marsupials dig for the fruiting bodies of hypogeous fungi they disturb the soil surface. The effect of these diggings was evaluated by laboratory and in situ assessments of soil water repellency. The undisturbed woodland soil surface showed severe water repellence whereas diggings had low water repellence, and appear to act as preferential water infiltration paths after autumn rainfall events. This indicates that Bettongia penicillata has an impact on the non-wetting property of soils in this region.  相似文献   
74.
宁夏沙坡头地区人工固沙植被种间水分竞争的初步研究   总被引:12,自引:1,他引:11  
冯金朝  陈荷生 《生态学报》1994,14(3):260-265
本文通过研究沙坡头地区人工固沙植被中油蒿和柠条对环境资源利用(包括时间,空间和水资源)所表现出的不同生长状况和生理生态特性,阐明了环境条件的动态变化,尤其是沙地表面结皮的形成、降水入渗浅层化对固沙植物水分利用与竞争的重要影响,结果表明,油蒿以其较强蒸腾耗水能力和根系的浅层密集分布,在与柠条的水分竞争中占据优势,能够更好地利用作为唯一水分来源的降水补给。  相似文献   
75.
摘要 目的:研究层黏连蛋白亚基β3(LAMB3)在头颈鳞癌(HNSCC)中的表达、预后价值、免疫相关性及作用机制。方法:利用基于癌症基因组图谱(TCGA)的多个在线数据库,分析LAMB3在HNSCC肿瘤组织中的差异表达、预后价值以及对免疫细胞浸润的影响;通过基因共表达及蛋白-蛋白相互作用网络分析,探究LAMB3参与HNSCC的生物过程以及相关信号通路;预测调控LAMB3基因的上游靶miRNA。结果:LAMB3在HNSCC中高表达,LAMB3表达水平与年龄分布、肿瘤病理分级、淋巴结转移状态和HPV病毒感染状态相关;预后分析显示LAMB3在HNSCC中高表达预示患者不良预后,在肿瘤分期为Stage3、白色人种、肿瘤病理分期为Grade1和Grade2以及肿瘤新生抗原高表达HNSCC患者中总生存期更短;LAMB3表达水平影响HNSCC肿瘤微环境,LAMB3高表达能够降低B细胞、CD8+T 细胞浸润程度,升高CD4+T细胞浸润程度;基因共表达和功能相关分析表明,LAMB3高表达与基底膜形成、细胞连接、细胞迁移等生物过程有关;LAMB3潜在靶miRNA是hsa-miR-24-3p。结论:LAMB3在 HNSCC中高表达与免疫细胞浸润和患者不良预后相关,可作为HNSCC发病风险和预后指标。  相似文献   
76.
The Dunning tumor, originally described as a carcinoma of the rat dorsal prostate, has for long been used as an experimental model of prostatic cancer. We have recently presented a number of morphological findings that are incompatible with the prostatic origin of the H-subline of the Dunning tumor. In this paper, biochemical and immunohistochemical markers of rat prostate and mammary gland are studied in the R-3327 Dunning H tumor. Pieces of the H tumor were inoculated in male or lactating female rats. The electrophoretic protein pattern of Dunning tumor extracts was more similar to that of the mammary gland than the dorsolateral prostate. Proteins selectively appearing after metabolic labeling in Dunning tumors grown in lactating rats corresponded to labeled proteins in mammary glands from the same animals. Secretory proteins typical of the lateral prostate (SVS II) and dorsal prostate (transglutaminase) could not be detected immunohistochemically in the Dunning tumor. Western blot studies of tumor extracts and slot blot analysis of RNA preparations from the tumor confirmed the absence of SVS II and prostate specific transglutaminase from the Dunning tumor. On the other hand, the presence of mammary gland proteins such as milk fat globule membrane proteins, lactoperoxidase and lactalbumin were detected in the Dunning tumor by immunohistochemistry and Western blotting, but were absent from the dorsolateral prostate. Transferrin-mRNA, expressed in the male urogenital tract and also in the liver and other tissues, was detected in the mammary gland and Dunning tumor, but not in the dorsolateral prostate. The absence of mammary gland secretory beta-casein in the Dunning tumor was related to the elevated Ha-ras oncogene expression in the tumor, previously reported to suppress casein expression. The findings clearly demonstrate that the prostate cannot be the origin of the Dunning tumor, presently being used in prostatic cancer research. The designation prostatic adenocarcinoma for this tumor is therefore invalid. Furthermore, the data support our view that mammary gland might be the origin of the Dunning tumor, although the derivation from the bulbourethral or the parotid glands cannot strictly be excluded.  相似文献   
77.
Summary We have previously reported that bleomycin and its derivative peplomycin enhance the release of cytokines by rat spleen cells during mitogen-stimulated cell culture in vitro, but liblomycin, another derivative of bleomycin, decreases cytokine release to below untreated control levels. Cytokine release correlated well with the inhibition of subcutaneous tumour growth after treatment with equivalent doses of the three analogues. In contrast, ascites tumour growth is completely inhibited by liblomycin and appears to be at least partly macrophage-mediated because the antitumour effect can be significantly inhibited by carageenan. This study shows that bleomycin and its analogues activate rat peritoneal macrophages and increase interleukin-6 release, O2 production, cell spreading, phagocytosis and random migration of macrophages, but only bleomycin enhances peritoneal macrophage invasion into a monolayer of rat lung endothelial cells in vitro. This study also shows that although liblomycin decreases spleen cell cytokine production and is less effective than bleomycin against subcutaneous tumour, as we have previously reported, the antitumour drug activates peritoneal macrophages and, compared to bleomycin, has a remarkable therapeutic effect on rat ascites tumour.  相似文献   
78.
The mechanism of water infiltration into a single-walled carbon nanotube (SWCNT) was investigated based on the molecular dynamics simulation. The influence of chemical functionalization treatment on unsaturated carbon atoms at the entrance of a SWCNT was explored. The chemical functionalisation treatment with hydroxyl groups can effectively reduce the critical pressure barrier and facilitate water molecules to invade a SWCNT. Conversely, the hydrogen groups can intensify the non-wetting ability of a SWCNT. In addition, the hydrogenated entrance system is of higher recovery performance under dynamic loading, while the system with hydroxylated entrance shows poor performance. The observed unique mechanisms provide a possible method in energy absorption and conversion.  相似文献   
79.
The roles of sodium-ATP (NaATP) and ferric-ATP complex (FeATP) on the proliferation and infiltration of lymphocytes have been studied by evaluation of the hypertrophy and histopathologic examination of spleen and liver, as well of the modifications in the elemental balance of iron, calcium, magnesium, and phosphorus. The results showed that in the implicated biochemical processes, calcium and magnesium have a principal role. An in vitro study on a cell model has permited one to evaluate the effects of deferoxamine, a known iron chelator and inhibitor of human lymphocyte proliferation, on FeATP-modified cellular calcium fluxes. These findings showing a reduced 45Ca2+ uptake in the presence of deferoxamine appear to indicate that in vivo the chelation of blood-borne iron by ATP might play a key role in proliferation and infiltration of lymphocytes, leading to lymphoma development.  相似文献   
80.
浙江安吉主要林地类型土壤渗透性   总被引:17,自引:0,他引:17  
对浙江安吉县龙王山地区主要植被类型的土壤渗透性进行了研究.结果表明,不同土地利用类型的土壤渗透性存在很大差别.根据土壤渗透能力可将8种植被类型分为4类:第1类,落叶阔叶林,土壤渗透能力极强;第2类,草地、松林、灌木林和茶园,土壤渗透能力强;第3类,毛竹林和常绿阔叶林,土壤渗透较强;第4类,裸露地,土壤较紧实,土壤结构较差,土壤通透性不佳,渗透能力弱.经主分量分析,得到表征渗透性能综合参数α和表征根系特征的综合参数β,构建了回归方程:α=0.1708eβ-0.3122.土壤理化性质、植被根系显著地影响土壤渗透性能.植被根系提高土壤入渗性能的实质是≤1 mm细根能有效地改善土壤性状.  相似文献   
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