焦化厂回收易地大修暨脱硫脱氰工程简介

本文叙述了国内先进的煤气净化工艺和氨、硫回收装置，净化了焦炉煤气，减少了环境污染，改善了硫铵质量，增加了硫磺新产品，提高了生产管理水平，确保了安全生产。     

焙烧炉天然气燃烧自动控制系统的研究与应用

介绍了炭素焙烧炉燃烧系统的改造,新型控制系统的功能介绍、使用效果和效益分析,通过改造真正实现了清洁生产,达到了节能效果,改善了工艺水平,提高了产品质量,降低了生产成本,提高了生产效率,改善了工作环境。     

延长锰硅合金矿热炉出铁口寿命的初步探讨

阐述了锰硅合金矿热炉出铁口损坏的机理。有针对性的采用了一些维护措施，延长了出铁口的使用寿命，改善了炉况，提高了产量，降低了生产成本，获得了一定的经济效益。     

抓斗吊车常见故障与解决措施

分析了20 t桥式抓斗起重吊车常见故障及原因,采取了相应的解决措施,从根本上杜绝了吊车的常见故障、节约了备件、降低了生产成本、减轻了维修人员劳动强度及提高了企业的经济效益.     

控冷电磁站搬迁方案的改进

通过大量的调查研究，查清了电磁站内渗漏水的缺陷，提出了解决方案和具体操作方法，改变了原定的搬迁方案，不仅彻底地消除了缺陷，还节约了大修费，缩短了工期，为生产创了可观的效益。     

冷床上卸钢液压系统改造

对原液压系统设计及使用中存在的问题 ,进行了分析、计算 ,找出了原因所在 ,提出了改造方案 ,从而有效地提高了液压系统的稳定性 ,减少了设备故障 ,降低了维护强度 ,提高了工作效率。     

武钢KR脱硫工艺改进

介绍了武钢炼钢总厂二分厂KR脱硫工艺的改进。通过优化了脱硫剂的成分,使脱硫效果得到明显改善,脱硫剂单耗大幅降低;优化了搅拌、扒渣工艺并采取底吹技术,大幅减少了扒渣过程中的金属损失;改进了搅拌器形状和制作工艺,提高了搅拌器寿命,并减少了修补料消耗;开发了脱硫自动控制模型,提高了生产效率,改善了操作环境。     

提高烧结配料生石灰消化除尘效果的生产实践

通过对烧结配料生石灰消化除尘系统进行改造,提高了除尘效果,同时稳定了生石灰配加量和消化打水量;充分回收利用了消化蒸汽和二次扬尘,减少了资源浪费,提高了消化水温,进一步强化了生石灰消化作用,提高了混合料制粒效果和混合料料温;极大地改善了配料室工作环境,有效降低了检修劳动强度,提高了设备作业率。     

安钢250／300轧钢机组加热炉循环水工程改造

安钢２５０／３００轧钢机组加热炉一次性水冷却改为软水闭路循环水冷却系统,保证了政党生产,节约了水资源,减少了外打破常规水量,保护了生态环境,同时降低了加热炉的故障率,减少了维修费用,提高了经济效益。     

ZDRH-2000智能集中润滑系统在435m~2烧结机上的应用

邯钢435m2烧结机采用了ZDRH-2000智能集中润滑系统克服了传统润滑的弊端;降低了能源的消耗;减少了备品备件的消耗;大大减少了设备日常维护的工作量;提高了设备生产效率;降低了生产成本。     

Heart rate variability, norepinephrine and ECG changes in subarachnoid hemorrhage patients

We have studied Pbs21, a major ookinete surface protein of Plasmodium berghei, for the development of a model transmission blocking immunogen. In the mouse, recombinant Pbs21 expressed in the Escherichia coli expression system (EcrPbs21) is not as effective in inducing transmission blocking antibodies as native Pbs21 (nPbs21), possibly because of differences in post-translational processing between EcrPbs21 and nPbs21. In an attempt to improve the efficacy of the recombinant molecule, we describe here the use of a baculovirus expression vector system in the silkworm Bombyx mori. Following an injection of recombinant baculovirus containing Pbs21 cDNA, B. mori larvae produced recombinant Pbs21 (BmrPbs21) with a molecular weight indistinguishable from nPbs21. Fifty micrograms of BmrPbs21 could be purified from the hemolymph of each infected larva using affinity chromatography. Immunization of Balb/c mice with BmrPbs21 induced high anti-BmrPbs21 and anti--ookinete antibodies but low anti-EcrPbs21 antibody. In contrast, EcrPbs21 induced high anti--EcrPbs21 antibody but low anti-BmrPbs21 and anti-ookinete antibodies. This suggests that most B-cell epitopes on nPbs21 are conformational and that many of the linear epitopes in EcrPbs21 are not normally exposed in nPbs21. Oocyst formation in Anopheles stephensi mosquitoes, which fed on mice immunized with purified BmrPbs21 and infected with P. berghei, was blocked by 85.5-97.1%. These results suggest that the baculovirus-silkworm system produces useful quantities of recombinant Pbs21 which in limited studies is structurally and immunogenically indistinguishable from the native molecule.     

Fighting the cold war: how information technology can help

OBJECTIVE: To detect the parental origin of extra chromosome 21 in Down syndrome, using two (GT)n polymorphic markers-D21S215 and D21S120. METHODS: The alleles of D21S215 and D21S120 were amplified by polymerase chain reaction and identified with denaturing polyacrylamide gel electrophoresis followed with Ag-staining. The parental origin of extra chromosome 21 was determined by comparing genotypes of probands with their parents. RESULTS: The parental origin of extra chromosome 21 was determined in 17 Down syndrome out of 24, with 12 and 5 inherited from mother and father respectively. CONCLUSION: The parental origin of extra chromosome 21 in Down syndrome can be determined by analyzing the polymorphisms of D21S215 and D21S120. Etiological study of trisomy 21 should be focused on maternal meiosis.     

Interaction with cyclin-dependent kinases and PCNA modulates proteasome-dependent degradation of p21

The cyclin-dependent kinase (CDK) inhibitor p21(Cip1/Waf1) plays an essential role in the control of cell proliferation by modulating the activity of cyclin/CDK complexes in response to various intracellular or extracellular signals. Small variations in p21 expression levels may determine whether it acts as an inhibitor or an assembly factor for cyclin/CDK complexes. It is therefore critical to better characterize the mechanisms regulating p21 abundance. Here, we show, using a tetracycline-regulated system in p53-deficient DLD-1 human colon cancer cells, that p21 protein levels and stability are regulated by the proteasome-dependent degradation pathway and by association with its partners, CDKs and PCNA. A p21 mutant deficient for interaction with CDKs, p21CDK-, displayed an enhanced stability and greatly reduced sensitivity to proteasome-mediated proteolysis, indicating that association with cyclin/CDK complexes may trigger p21 degradation. In contrast, a p21 mutant impaired in the interaction with PCNA, p21PCNA-, exhibited a decreased stability, suggesting that association with PCNA protects p21 from proteasome-dependent degradation. Furthermore, the abundance of p21 itself, in addition to protein-protein interactions, may also modulate p21 stability since we found that high levels of p21 expression overcome proteasome-dependent regulation of p21 accumulation.     

Loss of p21WAF1/CIP1 expression correlates with disease progression in gastric carcinoma

Previous studies have shown that tumour-suppressor genes play an important role in the progression of solid tumours. Recently, the p21WAF1/CIP1 tumour-suppressor protein has been reported to work as a critical downstream effector of p53 and a potent inhibitor of cyclin-dependent kinases. Thus, the p21WAF1/CIP1 gene is thought to play a central role in tumour suppression. In this study we investigated p21 protein expression in gastric carcinomas. A total of 172 primary gastric carcinoma specimens were immunohistochemically stained for p21 protein expression. Correlations between p21 expression and clinicopathological features were examined. Loss of p21 expression was observed in 104 of 172 tumour tissues (60.4%), and the frequency of p21 loss increased as the stage progressed. Expression of p21 in the primary tumour was frequently lost in patients with either lymph node, liver or peritoneal metastases as compared with patients without metastases. In patients with p21-negative tumours, the risk of recurrence following curative surgery was significantly higher, and the prognosis was significantly poorer than in patients with p21-positive tumours. Loss of p21 expression in primary gastric carcinoma correlates with disease progression. The status of p21 gene expression may have prognostic value in this disease.     

Analysis of autoantibody epitopes on steroid 21-hydroxylase using a panel of monoclonal antibodies

A panel of five mouse monoclonal antibodies (MAbs) to human recombinant steroid 21-hydroxylase (21-OH) were produced, characterized, and used to study the interaction of 21-OH autoantibodies (AAbs) with different epitopes on human 21-OH. AAbs in patients with isolated autoimmune Addison's disease, autoimmune polyglandular syndromes types I and II, and 21-OH antibody-positive patients without overt Addison's disease (25 patients in total) were studied. Four MAbs were IgG1 subclass, one was IgG2a, and all had kappa light chains. The affinities of four of the antibodies were in the range 2.0 x 10(8) M(-1) to 7.0 x 10(8) M(-1), and the affinity of the other was 2.3 x 10(7) M(-1) 21-OH MAbs did not cross-react with 17alpha-hydroxylase (17alpha-OH)) or P450 side chain cleavage enzyme. Studies using a series of 21-OH fragments allowed the identification of short stretches of amino acids (AA) that were involved in forming the MAb binding sites. AA 391-405, defined as epitope region (ER) 1, were found to be important for binding of M21-OH1 and M21-OH2, AA 406-411 (ER2) were important for M21-OH3 and M21-OH4 binding, and AA 335-339 (ER3) for M21-OH5 binding. In addition, MAb Fab or F(ab')2 fragments were used to study 21-OH AAb epitopes in competition experiments. These investigations demonstrated that 21-OH AAbs recognize similar epitopes to the MAbs, with ER2 and ER3 being part of two distinct major epitopes, and ER 1 being part of a minor epitope. Mixtures of M21-OH antibody Fab or F(ab')2 fragments caused almost complete inhibition (80%-95%) of AAb binding in 24 out of 25 sera, and in the case of the remaining serum, the effect was marked but incomplete (67% inhibition). There were no major differences between the binding characteristics of AAbs from patients with different forms of autoimmune adrenal disease. All five 21-OH MAbs reacted with human adrenal tissue in an immunofluorescence test, but only M21-OH1 and M21-OH2 reacted with bovine adrenal tissue in these experiments. None of the MAbs reacted with human ovarian tissue in an immunofluorescence test. Overall, these studies indicate that 21-OH AAbs bind to at least three different epitopes in the C-terminal part of 21-OH, and two of these epitopes appear to be human 21-OH specific.     

Expression of a novel form of p21Cip1/Waf1 in UV-irradiated and transformed cells

The tumor suppressor p53 and its target the CDK inhibitor p21 (Cip1/Waf1) are key components of the cellular response to DNA damage. Insight into how p21 is regulated in normal cells, and how it may be deregulated in tumor cells is important for the understanding of tumorigenesis. p21 was induced in normal human diploid fibroblasts after UV irradiation-induced DNA damage, but, at a high dose of UV irradiation, a faster mobility form of p21 on SDS-PAGE (designated p21delta) was expressed. Surprisingly, in a variety of growing transformed cell lines, the level of p21 was low but p21delta was prominent. We found that p21delta appeared to be derived through a loss of around 10 amino acids from the C-terminus of p21, which theoretically would remove the PCNA binding domain, a second cyclin binding domain and the nuclear localization signal sequence. Several characteristics distinguish p21 from p21delta. Both the full length p21 and p21delta could be stabilized by a proteasome inhibitor, but only the full length p21 was associated with Cdk2 and PCNA. Consistent with this, gel filtration chromatography revealed that all the full length p21 in the cell was complexed to other proteins, whereas a significant portion of p21delta was in monomeric form. Moreover, p21 was mainly localized to the nucleus, but p21delta was mainly localized to the cytoplasm. We propose that the decrease in p21 and increase in p21delta could contribute to the deregulation of the cell cycle, and could be a mechanism involved in cellular transformation.     

Immunological studies of a 21 kDa cellular component efficiently incorporated into rabies virion grown in a BHK-21 cell culture

To investigate cellular components incorporated into the rabies virion, monoclonal antibodies (MAbs) were screened based on their reactivity with additional virion components. Two of the MAbs we prepared recognized a virion-associated 21 kDa polypeptide (referred to as VAP21) from a BHK-21 cell. Since the MAbs precipitated the rabies virion and trypsin digestion eliminated the VAP21 antigen from the virion but alkaline treatment (pH 11) did not, VAP21 seems to be anchored into the viral envelope and exposed on the virion surface. Although quantitative immunoblot analyses indicated an apparently increased concentration of VAP21 in the virion, the ratio of the content of VAP21 to that of viral glycoprotein (G) was several times decreased as compared to the ratio of those in the cell. These data suggest that sorting of VAP21 occurs during the viral budding process on the cell but that it might be inefficient, probably due to a more intimate association of VAP21 with the viral envelope proteins. This assumption seems to be consistent with the results of immunofluorescence studies; that is, VAP21 displayed colocalized distribution with viral envelope antigens in the cell. From these results, it is suggested that VAP21 closely associates with the viral envelope proteins in the cell, and this association might cause passive but relatively efficient incorporation of VAP21 into the virion.     

Relationship between p21 expression and mutation of the p53 tumor suppressor gene in normal and malignant ovarian epithelial cells

In many cell types, p53-mediated growth inhibition is dependent on induction of p21, which is an inhibitor of cyclin-dependent kinases that are required for cell cycle progression. Failure of mutant p53 proteins to transactivate p21 may lead to uncontrolled proliferation. Because many ovarian cancers have mutations in the p53 gene, we examined p21 levels in normal and malignant ovarian epithelial cells to determine whether p21 expression is dependent on wild-type p53. Normal ovarian epithelial cells and two ovarian cancer cell lines with wild-type p53 expressed readily detectable levels of p21, whereas in p53 null and mutant cell lines, expression of p21 was diminished strikingly. A correlation between the status of the p53 gene and p21 expression also was noted in 23 primary epithelial ovarian cancers. Normal levels of p21 RNA were seen in 4/7 (57%) cancers with wild-type p53, whereas 14/16 (88%) cancers with mutant p53 had reduced p21 expression (P < 0.05). In addition, we found that lambda-irradiation of normal and malignant ovarian epithelial cells with wild-type, but not mutant, p53 resulted in induction of p21. These data are suggestive that induction of p21 is a feature of p53-mediated growth inhibition in normal ovarian epithelial cells. Conversely, mutation of the p53 gene in ovarian cancers usually is associated with decreased p21 expression. The lack of an absolute correlation between p21 expression and the status of the p53 gene in ovarian cancers is consistent with other studies that have suggested that p21 may also be regulated by p53-independent pathways.     

A conformation-dependent epitope in Addison's disease and other endocrinological autoimmune diseases maps to a carboxyl-terminal functional domain of human steroid 21-hydroxylase

Idiopathic Addison's disease develops as a consequence of autoimmune destruction of steroid-producing cells in the adrenal gland. A major autoantigen is 21-hydroxylase (21OH; P450c21), which is involved in the biosynthesis of cortisol and aldosterone in the adrenal cortex. We selected a number of functionally important 21OH amino acid substitutions, found in patients with congenital adrenal hyperplasia, to study their effects on the binding of 21OH autoantibodies (21OHAb) to 21OH. The ability of 21OHAb to bind in vitro transcribed and translated wild-type 21OH and five different 21OH mutant proteins was quantified by liquid-phase assays. Sera from 21OHAb-positive patients with idiopathic Addison's disease (n = 24), Graves' disease (n = 3), and insulin-dependent diabetes mellitus (n = 1) were used. While the P105L, delE196, and G291S mutations had no effect on autoantibody binding, the P453S mutation had a considerable effect, and the R483P mutation almost completely abolished binding. Synthetic peptides corresponding to linear epitopes defined by amino acids 447-461 and 477-491 were unable to compete with wild-type 21OH for binding to autoantibodies. Direct 21OH DNA sequencing could not reveal any specific genetic variation in alleles found in 21OHAb-positive patients. We conclude that the region involving R483 plays a key role in the formation of a three-dimensional epitope in a functionally important C-terminal domain of the enzyme.