Mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes with deterioration during pregnancy

We report a 31-year-old woman who developed myopathy and neuropathy during pregnancy. She was diagnosed as having mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS). A T-to-C transition mutation at nucleotide position 3271 was detected in the mitochondrial gene. Her symptoms subsided spontaneously and she delivered a male infant at 38 weeks of gestation. Prior reports on mitochondrial diseases with pregnancy are very rare, probably because of the early onset of the disease. The metabolic changes during pregnancy increase the stress on the mitochondrial function, particularly in patients with impaired mitochondrial function. Therefore pregnancy can aggravate mitochondrial diseases.     

战储备件储备比例的确定方法

战储备件的储备比例确定是优化装备保障的一项重要工作,采用理论计算与工程实践修正相结合的方法确定战储备件的储备比例。其中,理论计算根据自然故障、战损和战场消耗3个方面采取不同的计算方法。指出储备比例与产品数量有关,在实际应用中,没有产品数量的计算公式应该谨慎使用。工程实践修正主要考虑任务需求、作战消耗以及战时维修保障模式与储备布局。该方法容易理解,工程适用性强。     

瓮福磷肥厂重钙改产磷铵的物化数据测试研究

以瓮福磷精矿为原料进行了重钙改产磷酸二铵的物化数据测试研究。比较系统地研究了影响磷酸、磷铵物性的因素及变化规律 ,测定了有关物性数据及工艺技术指标、产品质量 ,所得结果表明不仅为重钙改产磷铵提供了依据 ,而且为大型磷铵厂的设计提供了基础数据。     

Use of segmental baffle in shell and tube heat exchanger for nano emulsions

Among the heat exchangers (HE), the shell and tube type is being widely used in different applications like oil, chemical, and power plant Industries. The incorporation of segmental baffles (SB) improves the HE capacity from higher temperature fluid to lower temperature fluid. Nanofluids can be effectively used to enhance the heat transfer rate. In this study, numerical simulations have been carried out in a shell and tube heat exchanger (STHX). Among HE design methods, Tubular Exchanger Manufacturers Association (TEMA) standard is being used for better design by many researchers. In this paper, the computational fluid dynamics analysis was carried out with Al₂O₃, CuO, and SiO₂ nanofluids amid 1, 3, and 5 vol. % with water emulsion to enhance the heat transfer coefficient of STHX. The nanofluid has been used in the cold fluid of the HE and on the other side hot water is used. From the results, it is noticed that with the increase of Nanofluids, the value of heat transfer coefficients is found to be increasing. The overall heat transfer coefficient has been enhanced for Al₂O₃, CuO, and SiO₂ about 10.41%, 12.27%, and 9.56%, respectively, at 0.22 kg/s for the 5 vol. % addition. It is also depicted that the pressure drop is increasing with the incorporation of nanofluids.     

1000kt／a粒状DAP联产200kt／a粉状MAP扩能方案剖析

某300 kt/a(P2O5计)磷酸、400×2 kt/a重过磷酸钙(TSP)装置,为适应市场需求,将一套400 kt/aTSP和300 kt/a磷酸装置采用传统的磷酸浓缩工艺,改造为600 kt/aDAP装置,试生产成功、基本达到设计能力后,拟利用仍闲置的400 kt/aTSP,并扩建一套300 kt/a磷酸装置,实现磷酸铵产量翻番的目标.针对传统的磷酸浓缩工艺生产DAP受系统水平衡制约,要求浓磷酸中ω(P2O5)≥48%,浓缩系统加热器中列管易结垢,DAP装置中尾气洗涤系统的开车率也欠高,扩能方案拟采用传统的磷酸浓缩工艺与中和料浆浓缩工艺相结合的新工艺,实现主产粒状DAP、联产粉状MAP,磷酸铵产量翻番.分析了利用该新工艺生产磷酸铵的优点,指出其在实现磷酸铵产量翻番中投资省、能耗低、操作稳定性高,并可消化利用本系统磷酸淤渣、含磷废渣,也为今后调整产品品种、进一步挖潜改造留有余地.     

Role of IAPP in the pathogenesis and development of NIDDM

Islet amyloid deposits are the characteristic lesions of the pancreas of the patients with non-insulin-dependent diabetes mellitus (NIDDM). Islet amyloid polypeptide (IAPP or amylin) is a 37 amino acid peptide, which was extracted and characterized from islet amyloid deposits in patients with NIDDM. Recent studies and characterization of IAPP cDNA suggest that IAPP is a normal islet hormone and is co-secreted with insulin from islet beta cells of the pancreas. In this paper, we review recent advance of the research for IAPP including our results, and discuss the role of IAPP in the development of NIDDM, and we propose a new type of diabetes, "amyloid diabetes".     

逆变弧焊电源电磁干扰防护的探讨

本文对逆变弧焊电源干扰的防护问题进行了探讨，提出电磁兼容的主要措施有屏蔽、滤波、接地技术、元器件选择、合理布局、合理走线等。     

工艺参数对高掺量耐水型磷石膏蒸压砖性能的影响

采用工业废渣磷石膏、磷渣粉、碱性激发剂为原料制备高掺量耐水型磷石膏蒸压砖,研究工艺参数对制品强度及耐水性能的影响.结果表明,随着混合物料水灰比的增大,耐水型磷石膏蒸压砖的抗压强度与软化系数先增大后下降:随着成型压力、预养护时间及蒸压温度的增大,磷石膏蒸压砖的强度与软化系数提高.制品的XRD以及SEM分析结果表明,磷渣粉被碱性激发剂激发后生成的水化产物主要是C-S-H凝胶及托勃莫来石.这些水化产物与磷石膏蒸压后所生成的无水硫酸钙晶体相互错生在一起,这种特殊的结构使得耐水型磷石膏蒸雎砖强度好、软化系数高,且磷石膏掺量大.     

工业湿法净化磷酸标准的制定

简要介绍了化工行业标准HG/T 4069-2008《工业湿法净化磷酸》的制定过程、工作进度、工作内容以及立项背景。将该标准与GB/T 2091-2008《工业磷酸》的主要指标参数进行对比,可知该标准指标设置合理,符合中国相关生产商和消费者的需求,实验方法科学、准确。该标准的优点为：1）生产成本低,经济效益显著;2）节能、减排,绿色生产;3）技术创新,标准先进;4）既有企业效益,也有社会效益,实现企业用户双赢。     

高聚合率的水溶性聚磷酸铵制备工艺研究

以湿法磷酸和尿素为原料制备高聚合率的水溶性聚磷酸铵,考察了尿素与磷酸的物质的量比、聚合温度和聚合时间对聚磷酸铵聚合率的影响。通过实验得到最优工艺条件：尿素与磷酸的物质的量比为1.4、聚合温度为180 ℃、聚合时间为1.0 h,所得产品的聚合率为98.20%,五氧化二磷质量分数为63.33%,氮质量分数为13.85%。该产品水溶性良好,通过XRD分析确定聚磷酸铵的晶型为Ⅰ型聚磷酸铵。