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1.
攀钢依托攀西地区(攀枝花—西昌)丰富的钒钛磁铁矿资源和技术优势,经过四十多年的发展,成为跨行业、跨地区的现代化钢铁钒钛企业集团。特别是"十五"以来,攀钢通过实施重点项目建设,推进兼并重组,加强自主创新,实现了经济规模增长、品种结构优化、盈利能力提升,拥有年产铁720万吨、  相似文献   

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Nutrients should be viewed as the earliest of the hormone signals which allowed an organism to respond to changes in its nutrient environment. Defining nutrient function at the nuclear level will permit us to understand how our dietary environment is related to the development of nutritionally related pathophysiologies such as diabetes, heart disease, and cancer. Moreover, through the application of molecular techniques, we will begin to understand how specific nutrients govern the developmental pattern of specific organs such as the kidney. In this review, the fatty acid synthase gene is employed as a model to demonstrate how one sequentially approaches questions pertaining to the regulation of gene expression by a nutrient, and the article presents a nuclear explanation for how dietary polyunsaturated fats decrease blood triglycerides. More importantly, studies of this nature provide a basis for screening genetically susceptible populations and information that will allow the nutritionists of the 21st century to customize a diet for patients at risk.  相似文献   

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The potential role of humoral immunity in regulating intrapulmonary growth of Legionella pneumophila in the immunocompetent host was investigated using a murine model of Legionnaires' disease. Intratracheal inoculation of A/J mice with a virulent strain of L. pneumophila (10(6) bacteria per mouse) resulted in the recruitment of B lymphocytes into the lung and the development of anti-L. pneumophila Ab. Opsonization of L. pneumophila in vitro with anti-L. pneumophila-specific mAb resulted in a significant decrease in intrapulmonary growth of the bacteria at 24 to 72 h postinfection. Transmission electron microscopic analysis of lung tissue from L. pneumophila- infected mice demonstrated that while there was no significant difference between phagocytosis of the unopsonized and opsonized L. pneumophila by alveolar macrophages at 24 h postinfection, phagocytosis of opsonized bacteria by alveolar mononuclear phagocytic cells was significantly enhanced at 48 h postinfection. Depletion of A/J mice of complement before intratracheal inoculation of opsonized L. pneumophila (10(6) bacteria per mouse) did not significantly alter intrapulmonary growth of L. pneumophila. These results suggest that anti-L. pneumophila Ab, produced during replicative L. pneumophila lung infections, may regulate intrapulmonary growth of L. pneumophila in the immunocompetent host by decreasing the viability of extracellular L. pneumophila and by enhancing phagocytosis of the bacteria by alveolar mononuclear phagocytic cells by a complement-independent mechanism.  相似文献   

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In order to investigate the role of acupuncture in the regulation of cellular immune function, we observed acupuncture therapy affecting the levels of T lymphocytes subgroup (CD3+, CD4+, CD8+), soluble interleukin-2 receptor (SIL-2R) and beta-endorphin (beta-EP) in the peripheral blood of patients with malignant tumors. Here was used the random-gioland method, the patients were divided into a group treated by acupuncture (acup. group, 20 cases) and a control group (20 cases). The acup. group was treated using points PC6, LI4, ST36, RN4 and location of symptomatic points bilaterally, one treatment of 30 min daily for 10 days. The results showed that there were increased levels of CD3+, CD4+ percentage, CD4+/CD8+ ratio and radioimmunoassay of beta-EP in blood plasma, a decreased level of SIL-2R after acup. The statistical significance was found to be remarkable (P < 0.01), so has a notable difference, the correlation analysis indicated: (1) there was a positive correlation between beta-EP and T-lymphocytes subgroups; (2) a negative correlation between beta-Bp and SIL-2R, so did it between T subgroups and SIL-2R. Our results showed that beta-EP enhanced immune function of patients by increased T lymphocyte subgroups, reduced SIL-2R, and this action of beta-EP may be mediated by opioid receptor. The above mentioned results prevented evidence that there was an adjusting-network of immune in the body, through this way, acup. therapy can heighten the cellular immune function of patients, providing a beneficial effect in anti-cancer treatment.  相似文献   

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Different delivery vehicles may target to different antigen presenting cells (APC) because of their composition, size and/or physical properties. In this study, we examined the priming of cytotoxic T lymphocyte (CTL) responses to a soluble exogenous protein in vivo, using various delivery vehicles. In addition, we determined the role of macrophages as APC in vivo for each of these delivery vehicles by comparing the induction of antigen-specific CTL and serum antibodies in normal and macrophage-depleted mice. Influenza A virus-derived virosomes, liposomes and monophosphoryl lipid A/squalene (MPLSQ) efficiently induced antigen-specific CTL as well as antibody responses, of which virosomes proved to be the most efficient inducers. In mice that were immunized with cell-associated antigen, strong CTL responses but no antigen-specific antibodies were detectable, while aluminium hydroxide and aluminium phosphate elicited antigen-specific antibodies but no CTL responses. Elimination of macrophages in vivo before immunization abrogated CTL responses induced with liposomes and MPL/SQ, but did not affect induction of antigen-specific CTL with virosomes or cell-associated antigen. Importantly, serum antibody levels were not altered after macrophage depletion, regardless of the delivery vehicle used, suggesting that in the absence of macrophages, other APC may phagocytose the exogenous antigens for major histocompatibility complex (MHC) class II processing and presentation. These results suggest that soluble exogenous antigens delivered in different carrier systems may be processed differently by different APC in vivo for MHC class I- or class II-restricted presentation.  相似文献   

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刘青  赵平  吴晓东  田乃媛 《工程科学学报》2005,27(2):235-239,249
运用冶金过程工程理论,对钢包运行过程进行深入的解析和较为系统的研究,形成了钢包运行控制技术,包括钢包运行过程解析、钢包运行时间的数学描述、钢包运行个数的三种计算方法、钢包运行过程温降、钢包运行频率及运行过程的优化.该项技术已经应用于5个工厂,并取得了明显的效益.  相似文献   

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To realize the full potential of biological databases (DBs) requires more than the interactive, hypertext flavor of database interoperation that is now so popular in the bioinformatics community. Interoperation based on declarative queries to multiple network-accessible databases will support analyses and investigations that are orders of magnitude faster and more powerful than what can be accomplished through interactive navigation. I present a vision of the capabilities that a query-based interoperation infrastructure should provide, and identify assumptions underlying, and requirements of, this vision. I then propose an architecture for query-based interoperation that includes a number of novel components of an information infrastructure for molecular biology. These components include a knowledge base that describes relationships among the conceptualizations used in different biological databases, a module that can determine the DBs that are relevant to a particular query, a module that can translate a query and its results from one conceptualization to another, a collection of DB drivers that provide uniform physical access to different database management systems, a suite of translators that can interconvert among different database schema languages, and a database that describes the network location and access methods for biological databases. A number of the components are translators that bridge the heterogeneities that exist between biological DBs at several different levels, including the conceptual level, the data model, the query language, and data formats.  相似文献   

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《钢铁冶炼》2013,40(3):176-181
Abstract

In the past few years a lot of research was carried out on the development of transformation induced plasticity (TRIP) assisted multiphase steels. Two principal ways were proposed: (i) controlled cooling during the hot rolling process to obtain hot rolled TRIP assisted multiphase steels and (ii) the combination of intercritical annealing and isothermal holding at bainite formation temperatures during continuous annealing resulting in cold rolled TRIP assisted steel products. Unfortunately, both thermomechanical methods proposed require a high silicon level to inhibit cementite precipitation to avoid a loss of stability for the metastable retained austenite. In addition, due to high silicon levels, red scale surface defects appear and only moderate hot dip galvanisability is possible. In this paper a new thermomechanical strategy for the production of high strength low alloyed TRIP assisted multiphase steels with good hot dip galvanisability and without red scale defects will be presented.  相似文献   

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Patients with chronic lymphoedema are prone to develop chronic infections and various tumours in the lymphoedematous limb, suggesting that regional immune surveillance is impaired. To test the hypothesis that cutaneous cell-mediated immunity is impaired, 35 women with postmastectomy lymphoedema were investigated using dinitrochlorobenzene to test the afferent and efferent loops of the allergic contact immune response. The results support the role of lymphatics as an important component of the immune response to allergens by the demonstration of impairment of both the afferent and efferent loops of the allergic contact dermatitis reaction, and confirm that there is suppression of immune competence in a lymphoedematous limb.  相似文献   

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Only in the duodenum and in the colon calcium is absorbed by a cellular 1,25 alpha-Vitamin D3-dependent transport mechanism. Calcium absorption is highest in the proximal large intestine, about ten times higher than in the duodenum or in the descending colon. 1,25 alpha-Vitamin D3 stimulates calcium transport by genomic (slow effect: synthesis of cytosolic calcium binding protein CabP and basolateral Ca-ATPase) and non-genomic action (rapid effect: transcaltachyia, liponomic effect at the brush border membrane). CabP-dependent translocation across the cytosol is thought to be rate limiting step of cellular calcium transport. However, only about 50% of calcium absorption is cellular mediated but the same amount of calcium convectively is absorbed by transepithelial water flow across the paracellular pathway (solvent drag effect). 1,25 alpha-Vitamin D3 not only activates cellular calcium absorption but also increases paracellular permeability for calcium by an unknown mechanism. However, essential steps in the cascade from the interaction of 1,25 alpha-Vitamin D3 with the specific receptor over the regulation of the synthesis of calcium binding and transporting proteins to the induction of cellular calcium transport are not as yet clearly understood. The exact feedback mechanism of synchronized calcium transport across the distinct subcellular compartments seems also to be resolved. Cellular calcium transport is not found in the jejunum or in the ileum, what can be explained by the absence of specific 1,25 alpha-Vitamin D3-dependent carrier systems in these segments. On the other hand calcium is secreted across the jejunum and ileum by an anomalous solvent drag effect. Hence, intestinal calcium metabolism seems to underlie an eneteroenteral circuit: 1,25 alpha-Vitamin D3-controlled cellular calcium absorption across the duodenum is followed by paracellular calcium secretion across the jejunum and ileum. The carrier in the proximal colon which works at the optimal level already under normal nutritional condition could be of physiological importance for the reclamation of unabsorbed dietary calcium and for the reabsorption of calcium that is secreted across the distal small intestine. Under certain pathophysiological conditions, i.e. malabsorption in proximal segments or malnutrition, calcium in addition may be conserved by the 1,25 alpha-Vitamin D3-sensitive carrier in the descending colon.(ABSTRACT TRUNCATED AT 400 WORDS)  相似文献   

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Minimal mutation trees, and almost minimal trees, are constructed from two data sets, one of phenylalanine tRNA sequences, and the other of 5S RNA sequences, from a diverse range of organisms. The two sets of results are mutually consistent. Trees representing previous evolutionary hypotheses are compared using a total weighted mutational distance criterion. The importance of sequence data from relatively little-studed phylogenetic lines is stressed. A procedure is illustrated which circumvents the computational difficulty of evaluating the astronomically large number of possible trees, without resorting to suboptimal methods.  相似文献   

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通过对焦炉集气管压力与回收初冷器前吸力的关系分析,鼓风机液力耦合器的观察试验,提出了对角行程勺管电动执行机构调节的新思路,并详细介绍了控制调节新方案的计算机程序设计方法.  相似文献   

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