采用DOE实验设计方法改进电容器级铌粉酸洗工艺

采用DOE实验设计方法,对制备电容器用铌粉的酸洗除杂工艺进行研究,确定了影响铌粉性能的关键因素是酸洗除杂工艺使用酸的浓度和酸洗时间。通过关键因素的全因子正交试验,对产品质量和工艺参数进行量化分析,确定最佳的酸洗工艺,可有效减低和控制电容器级铌粉中的主要C、O非金属及Fe、Ni、Cr金属杂质含量,降低电容器级铌粉的漏电流和损耗,提高电容器级铌粉的性能。     

PE－AA辐射接枝共聚合的反应历程研究

研究了聚乙烯（ＰＥ）与丙烯酸（ＡＡ）、甲基丙烯酸（ＭＡＡ）的接枝共聚反应，探讨了接枝反应过程及特征：单体首先在ＰＥ表面接枝，然后进入内部进行本体接枝。研究表明：表面接枝为动力学控制，本体接技系扩散控制，单体在膜内的扩散与单体极性及聚合物的结晶度等有关     

碱性氨基酸辐射保护机理的电子自旋共振研究

本文研究了组氨酸和精氨酸对胸腺嘧啶的辐射保护机理。用ESR方法和分子轨道计算确证其辐射保护是由于电子清除和从胸腺嘧啶阴离子向碱性氨基酸的转移。碱性氨基酸的亲电子性能随质子化程度而异,在pH=7的条件下,组氨酸对胸腺嘧啶的辐射保护机理可能是电子转移与氢原子转移的协同过程。     

三价锰光度法快速测定铬镍锰高合金中高含量锰

在磷酸介质中，于220℃温度下，用高氯酸将二价锰氧化为三价锰，因三价锰离子的摩尔浓度系数远较七价锰离子的小，借此可做高含量锰的光度法分析。     

120 kt/a硫磺制酸水管锅炉改造为火管锅炉的技术总结

介绍FRS-12S-14.5/3.82-450型余热水管锅炉以较少的投资、较少的工程量、较短的施工周期改造成QF35/1050-14.2-3.82/450型火管锅炉,使热力系统满足了120kt/a硫磺制酸装置的工艺要求。改造后系统运行平稳,运行率提高,维护费用减少,生产成本降低,解决了水管锅炉因换热管束爆管导致锅炉腐蚀及烟气泄漏造成的环境污染等问题。     

浙江省硫酸工业进展

介绍近6年来浙江省的硫酸产能和产量及下游耗酸产业结构.浙江省2005年硫酸产量占全国总产量的3%,预计2006年产量将达到1 600 kt.建议缓建硫酸装置,积极发展耗酸行业,控制进口酸量,加强企业间的协调,以使浙江省的硫酸市场在新的供需形势下建立起新的平衡.     

建龙化工新建150 kt/a硫磺制酸装置的几个特点

为保证原有4 500 kW发电机组满负荷运行的蒸汽供给及考虑当地硫酸市场的需求,新建一套150 kt/a硫磺制酸装置.该装置以原120 kt/a硫磺制酸装置的设计为蓝本,进行一定改进.在装置设备的选型配套、熔硫工序的挖潜改造、严冬季节土建施工、风机噪音消除等方面采取了相应措施.装置开车以来运行良好,达到设计要求.     

The Effect of Formulation on Radioiodide Thyroid Uptake in the Hyperthyroid Cat

This investigation was designed to compare in vitro dissolution profiles from sodium iodide capsules with radioiodide thyroid uptake in hyperthyroid cats using sodium iodide capsules prepared with a formulation exhibiting a complete release of radioiodide (I-123) in vitro and a formulation with an incomplete release of radioiodide. In vitro dissolution profiles for I-123 sodium iodide capsules with two different formulations were determined using the USP XXIII dissolution test. The two formulations studied in vitro were sodium phosphate dibasic powder with 1% magnesium stearate and calcium phosphate dibasic powder with 3% magnesium stearate. By 20 min after initiation of the dissolution test, over 95% of the I-123 was released from capsules of sodium phosphate dibasic powder. The capsules of calcium phosphate dibasic powder reached 75% at 65 min, with no further release occurring thereafter. There was a statistically significant difference in the dissolution profiles of the two formulations. The thyroid uptake of I-123 from capsules exhibiting complete release and incomplete release of radioiodide was determined in hyperthyroid cats. At 4 hr, the mean percentage thyroid uptake value for sodium phosphate dibasic powder with 1% magnesium stearate (complete release formulation) was 12.0% compared to 9.4% for calcium phosphate dibasic powder with 3% magnesium stearate (incomplete release formulation); at 24 hr, the values were 34.4% compared to 23.7%. The data suggest that the incomplete dissolution profile observed in vitro may correlate with a reduction in the bioavailability of the radioiodide in vivo. However, using the Wilcoxon signed rank test, statistically significant differences did not occur between the complete release formulation and incomplete release formulation at either 4 hr or 24 hr (p >. 05). The results of the in vivo study with five hyperthyroid cats were not conclusive due to the variability in response between individual cats.     

Roles of the Unsaturated Fatty Acid Docosahexaenoic Acid in the Central Nervous System: Molecular and Cellular Insights

Fatty acids (FAs) are essential components of the central nervous system (CNS), where they exert multiple roles in health and disease. Among the FAs, docosahexaenoic acid (DHA) has been widely recognized as a key molecule for neuronal function and cell signaling. Despite its relevance, the molecular pathways underlying the beneficial effects of DHA on the cells of the CNS are still unclear. Here, we summarize and discuss the molecular mechanisms underlying the actions of DHA in neural cells with a special focus on processes of survival, morphological development, and synaptic maturation. In addition, we examine the evidence supporting a potential therapeutic role of DHA against CNS tumor diseases and tumorigenesis. The current results suggest that DHA exerts its actions on neural cells mainly through the modulation of signaling cascades involving the activation of diverse types of receptors. In addition, we found evidence connecting brain DHA and ω-3 PUFA levels with CNS diseases, such as depression, autism spectrum disorders, obesity, and neurodegenerative diseases. In the context of cancer, the existing data have shown that DHA exerts positive actions as a coadjuvant in antitumoral therapy. Although many questions in the field remain only partially resolved, we hope that future research may soon define specific pathways and receptor systems involved in the beneficial effects of DHA in cells of the CNS, opening new avenues for innovative therapeutic strategies for CNS diseases.     

The Cytoskeletal Protein Zyxin Inhibits Retinoic Acid Signaling by Destabilizing the Maternal mRNA of the RXRγ Nuclear Receptor

Zyxin is an LIM-domain-containing protein that regulates the assembly of F-actin filaments in cell contacts. Additionally, as a result of mechanical stress, Zyxin can enter nuclei and regulate gene expression. Previously, we found that Zyxin could affect mRNA stability of the maternally derived stemness factors of Pou5f3 family in Xenopus laevis embryos through binding to Y-box factor1. In the present work, we demonstrate that Zyxin can also affect mRNA stability of the maternally derived retinoid receptor Rxrγ through the same mechanism. Moreover, we confirmed the functional link between Zyxin and Rxrγ-dependent gene expression. As a result, Zyxin appears to play an essential role in the regulation of the retinoic acid signal pathway during early embryonic development. Besides, our research indicates that the mechanism based on the mRNA destabilization by Zyxin may take part in the control of the expression of a fairly wide range of maternal genes.