Simplified Mass Spectrometric Analysis of Ceramides using a Common Collision Energy

Ceramides (CER) are biologically active sphingolipid precursors that are mechanistically linked to several pathogenic states including cancer, insulin resistance, and neurodegeneration. CER are commonly quantified through mass spectrometry-based methods founded upon a product ion scan (PIS) in positive mode to produce a characteristic m/z 264 ion. The ionization efficiency (IE) of CER species decreases with an increase in CER mass, thus quantitation of CER typically involves application of mass-dependent response factors (RF) for each CER species. In this work, we observed that the RF were systematically dependent on the number of fatty acid acyl carbons and the collision energy (CE) used to generate the m/z 264 ion. Using these complimentary trends, we determined an “isosbestic” CE where the RF for all CER species were equivalent, allowing for CER quantitation without postcollection correction factors. A comparison of this common CE/common RF method to the multiple RF method demonstrated good agreement between the two methods. Use of the common CE/common RF method will reduce data processing and reduce the use of multiple CER species standards.     

Analysis and design of the capacity and efficiency of a flywheel energy storage system

分析了飞轮储能系统能量、功率参数特性。飞轮储能系统单机可实现储能0.5 ～ 100 kW·h、功率2～ 3000 kW。提出了储能100 kW·h级飞轮的方案,采用中低转速合金钢飞轮转子,储能密度13～ 18 W·h/kg,计算许用应力为800 MPa。尺寸为米级的飞轮转子整体锻造难度较高,可采用多圆盘轴向联接的结构设计。采用3层或4层纤维缠绕复合材料高速飞轮转子结构,分别进行了径向等应力结构设计,计算表明9000 r/min三层纤维缠绕复合材料飞轮和15000 r/min四层纤维缠绕复合材料飞轮均能够满足工作转速下的结构强度要求,储能密度50 ～ 70 W·h/kg。     

基于ANP-GRA-TOPSIS法的中国部分省份页岩气产业风险评价研究

近年来,中国部分省级政府高度重视页岩气资源的勘探开发,试图推进本省页岩气产业发展。受地质条件、开发技术等风险因素影响,各省在页岩气开发浪潮中表现各异。为此,通过流程分析法和专家咨询法对页岩气产业风险进行了识别,并从资源风险、技术风险、经济风险、政策与体制风险、环境风险着手,构建了省级页岩气产业风险评价指标体系;建立ANP-GRA-TOPSIS综合模型,对中国12个省份页岩气产业风险进行了实证分析。结果显示:重庆市、四川省页岩气产业风险相对较低,新疆、内蒙古、云南、陕西、贵州、湖南、山西、安徽、湖北以及江苏面临的页岩气产业风险相对较高。为推动我国页岩气产业进一步发展,建议在川渝等地区加快建设页岩气勘查开发试验区,成立国家级页岩气勘探基金,构建全方位的金融支持体系等。     

压杆断裂原因分析

对失效压杆的化学成分、裂纹及断口特征、显微组织、硬度等进行了综合分析,结果表明其过早脆性断裂主要由钢中氧化物及硅化物夹杂所引起,原有的结构设计不当,加快了压杆的早期失效.更换脱氧、去硅更加彻底的合格钢材,同时将压杆杆部加工成直径均匀的光杆后,未发生压杆过早断裂失效.     

Examination of camptothecin and 10-hydroxycamptothecin in <i>Camptotheca acuminata</i> plant and cell culture,and the affected yields under several cell culture treatments

Camptothecin and its derivatives are monoterpenoid indole alkaloids exhibiting significant anti-tumor actions. With the aim of improving the production of these pharmaceuticals, the contents of camptothecin and 10-hydroxycamptothecin in different tissues including roots, stems, leaves, young flower buds, opening flowers, fading flowers and seeds from Camptotheca acuminata, were investigated. The young flower buds had the highest alkaloid concentrations (camptothecin, 2.46 mg/g of dry weight; 10- hydroxycamptothecin, 1.41 mg/g of dry weight). Callus showed lower concentrations but it should also be considered as a potential source of these pharmaceuticals. In the present study, the growth rate of Camptotheca acuminata cells in culture did not correlate with contents of camptothecin and 10-hydroxycamptothecin. Alkaloid accumulation by cells under various treatments (heavy metal ions, UV-B), methyl-jasmonate, abscisic acid, salicylic acid and hydrogen peroxide was examined, and the most notable effects appeared in the cells induced by UV-B light (which showed an 11-fold increase in camptothecin concentration) and by salicylic acid (which showed a 25-fold increase in 10-hydroxycamptothecin concentration). These results are significant in the context of the production of both pharmaceuticals.     

Temperature and pressure imaging using infrared planar laser-induced fluorescence

A new diagnostic technique for measurements of temperature and pressure distribution in gaseous flows has been developed. The technique, based on infrared planar laser-induced fluorescence (IR-PLIF), is applicable to all IR-active species. A simple two-line excitation approach is used for measurements of temperature, while pressure measurements utilize online excitation on one rotational line and offline excitation on another. A demonstration of the technique in a supersonic underexpanded jet of 30% CO2 and 70% N2 was performed, and the results are, to the best of our knowledge, the first demonstration of temperature and pressure imaging using IR-PLIF. The developed diagnostic shows potential for single-shot two-dimensional measurements of temperature and pressure in gaseous flows.     

Teriflunomide Inhibits JCPyV Infection and Spread in Glial Cells and Choroid Plexus Epithelial Cells

Several classes of immunomodulators are used for treating relapsing-remitting multiple sclerosis (RRMS). Most of these disease-modifying therapies, except teriflunomide, carry the risk of progressive multifocal leukoencephalopathy (PML), a severely debilitating, often fatal virus-induced demyelinating disease. Because teriflunomide has been shown to have antiviral activity against DNA viruses, we investigated whether treatment of cells with teriflunomide inhibits infection and spread of JC polyomavirus (JCPyV), the causative agent of PML. Treatment of choroid plexus epithelial cells and astrocytes with teriflunomide reduced JCPyV infection and spread. We also used droplet digital PCR to quantify JCPyV DNA associated with extracellular vesicles isolated from RRMS patients. We detected JCPyV DNA in all patients with confirmed PML diagnosis (n = 2), and in six natalizumab-treated (n = 12), two teriflunomide-treated (n = 7), and two nonimmunomodulated (n = 2) patients. Of the 21 patients, 12 (57%) had detectable JCPyV in either plasma or serum. CSF was uniformly negative for JCPyV. Isolation of extracellular vesicles did not increase the level of detection of JCPyV DNA versus bulk unprocessed biofluid. Overall, our study demonstrated an effect of teriflunomide inhibiting JCPyV infection and spread in glial and choroid plexus epithelial cells. Larger studies using patient samples are needed to correlate these in vitro findings with patient data.     

OH time-histories during oxidation of n-heptane and methylcyclohexane at high pressures and temperatures

OH concentration time-histories during n-heptane and methylcyclohexane (MCH) oxidation were measured behind reflected shock waves in a heated, high-pressure shock tube. Experimental conditions covered temperatures of 1121 to 1332 K, pressures near 15 atm, and initial fuel concentrations of 750 and 1000 ppm (by volume), and an equivalence ratio of 0.5 with O₂ as the oxidizer and argon as the bath gas. OH concentrations were measured using narrow-linewidth ring-dye laser absorption near the R-branchhead of the OH A-X(0,0) system at 306.47 nm. These current measurements together with our recent results for n-dodecane oxidation [S.S. Vasu, D.F. Davidson, Z. Hong, V. Vasudevan, R.K. Hanson, Proc. Combust. Inst. 32 (2009), doi:10.1016/j.proci.2008.05.006] provide critically needed validation targets for jet fuel surrogate kinetic mechanisms and further improve understanding of high-pressure, high-temperature oxidation chemistry. Detailed comparisons of these OH time-histories with the predictions of various kinetic mechanisms were made. Sensitivity and pathway analyses for these reference fuel components were performed, leading to reaction rate recommendations with improved model performance. Current results are the first quantitative measurements of OH time-histories during high-pressure oxidation of these fuels, and hence are a critical step toward development of accurate reaction models for jet fuel surrogates.     

一种基于数据链管理的印刷 ERP 解决方案

目的为了克服传统印刷ERP的不足,开发出一套满足印刷企业需要,能够解决企业管理面临的问题,易学好用的印刷ERP解决方案。方法通过对多家印刷企业的调研,总结了印刷企业管理中存在的主要问题,以工单为核心,开发出一款基于数据单据链条化的新型印刷ERP系统。结果新系统能很好地解决印刷企业管理中存在的各种问题。通过124家企业的试用,满意度高达91%,其中物料损耗降低了7%,部门协作效率提高了3倍,平均每个工单节约了5个工时,管理成本下降了3.7%,企业平均利润上升了2.3%。结论基于数据单据链条化的印刷ERP解决方案,把传统印刷企业管理中复杂、繁琐的信息进行简化,达到"轻松、易用"的目标,并快速地得到企业的认同和正式使用。     

油气行业数字化创新模式与启示

深入研究油气行业数字化创新模式对推动国内石油公司数字化进程具有重要意义。本文分析了油气行业数字化创新的原因,总结了国际主要油气公司和油服公司的数字化创新模式:通过自主研发,确定数字化前沿技术布局方向;加强技术合作,与科技企业共同开发数字化技术;通过技术并购,提升数字化技术服务能力;开展风险投资,挖掘数字化技术市场潜力。通过上述分析与总结,得到数字化服务已成为油气行业发展新蓝海、业务与技术基础决定石油公司数字化布局与策略、数字化平台对油气行业数字化转型日趋重要、数字化安全风险不容忽视四点启示,并提出了针对性的对策建议。