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61.
He H S  Wang W J  Zhu H  Zu Y G  Zhang Z H  Guan Y  Xu H N  Yu X Y 《农业工程》2008,28(11):5338-5346
China is one of the largest countries with huge amount of saline-sodic soil. How to ameliorate these lands is a hotspot in China. Through measurement of soil salinity, pH value and seed germination and growth status of cabbage seedlings, 17 kinds of krilium were added to experimented soil to evaluate their effects on amelioration of heavy saline-sodic soil. Firstly, among these 17 kinds of krilium, 11 (HPMA, gypsum, HEDP, T225, PAPEMP, MA-AA, ATMP, AA/AMPS, PAA, charcoal and BHMTPMPA) were effective agents and could effectively induce seed germination without any germination phenomena in the control saline-sodic soil. HPMA was the best one in ameliorating saline-sodic soil, which has been manifested by various indices of seed germination. Secondly, addition of gypsum together with other organic agents could strongly increase the ameliorative effectiveness if compared with relatively weak agents, while decrease seed germination if compared with the stronger agent of the 2 mixed agents, showing that the synergetic effect between gypsum and other kinds of tested krilium was not evident. Thirdly, optimum dosages for separate addition of HPMA and gypsum were 42.8 L m?3 and 25 kg m?3, while mixed-addition of these 2 agents at the same dosages did not cause plus effect in soil improvement. Finally, field application of HPMA could enhance the growth of cabbage seedlings at the first month, but began to wilt thereafter. Thus, instead of one-time addition, several-time addition of HPMA at the suitable dosage in field practice could strengthen the effectiveness of soil amelioration.  相似文献   
62.
Advancing age decreases endothelial function; accordingly, it alters the physiological regulation of coronary blood flow. Ginkgo biloba extract (GBE) has well-documented anti-ageing effects. However, little is yet known about the pharmacological actions of GBE on endothelial dysfunction and coronary blood flow in healthy elderly adults. We designed the study to test the effects of GBE on distal left anterior descending coronary artery (LAD) blood flow and endothelium-dependent brachial artery flow-mediated dilation (FMD) in healthy elderly adults.Sixty healthy elderly adults were randomly assigned to either GBE or control groups. LAD blood flow and brachial artery FMD were measured non-invasively using high-resolution ultrasound before and after intravenous administration of GBE or saline. GBE significantly increased LAD blood flow in maximal diastolic peak velocity (MDPV), maximal systolic peak velocity (MSPV) and diastolic time velocity integral (DTVI) compared with the placebo group (19.16±13.91% vs. 0.30±2.55%, 17.76±14.56% vs. 0.53±2.32%, and 21.73±16.13% vs. 0.81±2.33%, MDPV, MSPV, and DTVI improvement from baseline, respectively, p<0.01). Brachial artery FMD was also increased by 56.03% (from 7.21±2.52% to 11.28±3.95%, p<0.01). A linear correlation was found between the percentage change in MDPV, MSPV, or DTVI of LAD blood flow and the percentage change in brachial artery FMD following treatment with GBE (r=0.538, 0.366, or 0.573, respectively, p<0.01, p<0.05, or p<0.01). Our data demonstrate that GBE treatment in healthy elderly adults leads to the increase of LAD blood flow in MDPV, MSPV and DTVI, and the increased response might relate to the improved endothelium-dependent vasodilatory capacity. This study implies an important future therapeutic strategy of using GBE to counteract the detrimental effects of ageing.  相似文献   
63.
以Reid、唐四平头和其他种质等3个杂种优势类群共30份玉米自交系为实验材料,以玉米幼胚作为外植体,研究基因型、培养基、激素、继代培养次数对玉米幼胚愈伤组织诱导及植株再生的影响.研究结果表明供试材料均能进行愈伤组织诱导,但是只有部分自交系能再生植株.通过对不同杂种优势类群自交系玉米幼胚培养特性的分析,从Reid、唐四平头和其他种质类群的供试自交系中,筛选出了胚性愈伤组织诱导频率和绿苗分化率均较高、适合于遗传转化的受体材料,如黄野四/京24//C108/黄野四选系、黄早四/先早17//吉853选系、R43//黄野四/711选系、京7、京7黄、3189/4380选系、4380/陕综5选系、8103、先早17、18-599红、501、178和冀53.  相似文献   
64.
人妊娠期间,胎盘合成大量的类固醇激素,与妊娠的启动、维持、分娩以及胎儿的发育均存在密切的关系。阐明胎盘类固醇激素特别是孕酮合成与分泌的调节机制对于寻找理想的生育调控技术和生殖保健方法具有重要的意义。因此,胎盘类固醇激素合成与分泌的调节向来是生殖生物学与妇产科学领域所关注的焦点问题之一,  相似文献   
65.
The establishment and maintenance of cellular polarity are critical for the development of multicellular organisms. PAR (partitioning-defective) proteins were identified in Caenorhabditis elegans as determinants of asymmetric cell division and polarized cell growth. Recently, vertebrate orthologues of two of these proteins, ASIP/PAR-3 and PAR-6, were found to form a signalling complex with the small GTPases Cdc42/Rac1 and with atypical protein kinase C (PKC). Here we show that ASIP/PAR-3 associates with the tight-junction-associated protein junctional adhesion molecule (JAM) in vitro and in vivo. No binding was observed with claudin-1, -4 or -5. In fibroblasts and CHO cells overexpressing JAM, endogenous ASIP is recruited to JAM at sites of cell-cell contact. Over expression of truncated JAM lacking the extracellular part disrupts ASIP/PAR-3 localization at intercellular junctions and delays ASIP/PAR-3 recruitment to newly formed cell junctions. During junction formation, JAM appears early in primordial forms of junctions. Our data suggest that the ASIP/PAR-3-aPKC complex is tethered to tight junctions via its association with JAM, indicating a potential role for JAM in the generation of cell polarity in epithelial cells.  相似文献   
66.
ABC-type transport proteins, such as P-glycoprotein (P-gp), modify intracellular concentrations of many substrate compounds. They serve as functional barriers against entry of xenobiotics (e.g., in the gut or the blood-brain barrier) or contribute to drug excretion. Expression of transport proteins in the heart could be an important factor modifying cardiac concentrations of drugs known to be transported by P-gp (e.g., beta-blockers, cardiac glycosides, doxorubicin). We therefore investigated the expression and localization of P-gp in human heart. Samples from 15 human hearts (left ventricle; five non-failing, five dilated cardiomyopathy, and five ischemic cardiomyopathy) were analyzed for expression of P-gp using real-time RT-PCR, immunohistochemistry, and in situ hybridization. Immunohistochemistry revealed expression of P-gp in endothelium of both arterioles and capillaries of all heart samples. Although P-gp mRNA was detected in all samples, its expression level was significantly reduced in patients with dilated cardiomyopathy. We describe variable expression of P-gp in human heart and its localization in the endothelial wall. Thus, intracardiac concentrations of various compounds may be modified, depending on the individual P-gp level.  相似文献   
67.
68.
Bemisia tabaci Genn. biotype B is a widely distributed plant pest that represents one of the major constraints for horticultural crop production. The purpose of the present work was to evaluate the oviposition preference, survivorship, and development of B. tabaci biotype B on semi-cultivated genotypes of Capsicum annuum from southeast Mexico. In free-choice experiments to evaluate the oviposition preference, lower number of eggs laid by B. tabaci biotype B was observed in the genotypes Maax and Xcat´ik relative to that in the commercial genotype Parado. Egg hatchability was significantly lower in Pico Paloma, Bolita, Blanco, Chawa, Payaso, and Xcat´ik than in the rest of the genotypes, including the commercial genotype Jalapeño. Likewise, survivorship of nymphs was significantly lower in Pico Paloma, Bolita, and Blanco than in the remaining genotypes. Nymph developmental time and the period of development from egg to adult were the shortest in Amaxito. Therefore, sources of resistance to B. tabaci biotype B by antibiosis (accumulation of plant defense compounds) might be found in the semi-cultivated genotypes Pico Paloma, Bolita, and Blanco.  相似文献   
69.
Altered expression and function of lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) has been associated with several diseases such as endothelial dysfunction, atherosclerosis and obesity. In these pathologies, oxLDL/LOX-1 activates signaling pathways that promote cell proliferation, cell motility and angiogenesis. Recent studies have indicated that olr1 mRNA is over-expressed in stage III and IV of human prostatic adenocarcinomas. However, the function of LOX-1 in prostate cancer angiogenesis remains to be determined. Our aim was to analyze the contribution of oxLDL and LOX-1 to tumor angiogenesis using C4-2 prostate cancer cells. We analyzed the expression of pro-angiogenic molecules and angiogenesis on prostate cancer tumor xenografts, using prostate cancer cell models with overexpression or knockdown of LOX-1 receptor. Our results demonstrate that the activation of LOX-1 using oxLDL increases cell proliferation, and the expression of the pro-angiogenic molecules VEGF, MMP-2, and MMP-9 in a dose-dependent manner. Noticeably, these effects were prevented in the C4-2 prostate cancer model when LOX-1 expression was knocked down. The angiogenic effect of LOX-1 activated with oxLDL was further demonstrated using the aortic ring assay and the xenograft model of tumor growth on chorioallantoic membrane of chicken embryos. Consequently, we propose that LOX-1 activation by oxLDL is an important event that enhances tumor angiogenesis in human prostate cancer cells.  相似文献   
70.
T Zu  S Goyard  R Rappuoli    V Scarlato 《Journal of bacteriology》1996,178(10):2982-2985
BpH1, the Bordetella pertussis H1 homolog, interacts with chromosomal DNA. With DNase I protection assays, we demonstrate in this study that BpH1 binds DNA in a nonspecific manner and that it may cover DNA fragments from end to end. Although the binding was shown to be nonspecific, preferential binding sites and sites resistant to BpH1 binding were identified within and upstream of the pertussis toxin promoter sequence. In the presence of DNA ligase, BpH1 favored the formation of multimeric DNA fragments of various sizes and prevented ring closures, suggesting a diminished flexibility of the DNA fragments and thus indicating that BpH1 acts as a macromolecular crowding agent.  相似文献   
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