A New HPLC-MS Method for Measuring Maslinic Acid and Oleanolic Acid in HT29 and HepG2 Human Cancer Cells

Maslinic acid (MA) and oleanolic acid (OA), the main triterpenic acids present in olive, have important properties for health and disease prevention. MA selectively inhibits cell proliferation of the HT29 human colon-cancer cell line by inducing selective apoptosis. For measuring the MA and OA concentration inside the cell and in the culture medium, a new HPLC-MS procedure has been developed. With this method, a determination of the amount of MA and OA incorporated into HT29 and HepG2 human cancer-cell lines incubated with different concentrations of MA corresponding to 50% growth inhibitory concentration (IC₅₀), IC_50/2, IC_50/4, and IC_50/8 has been made. The results demonstrate that this method is appropriate for determining the MA and OA concentration in different types of cultured cells and reveals the specific dynamics of entry of MA into HT29 and HepG2 cells.     

悦29区防腐工艺应用及效果评价

本文主要针对悦29区的腐蚀严重的生产现状,对腐蚀原因进行分析,从区块使用各类防腐工艺的防腐原理及优缺点进行评价入手,结合现场应用效果、下井寿命进行了系统的评价,同时提出下步改进意见,为今后该区块防腐工艺的配套提供了一定的参考。     

Numerical evaluation of wind effects on a tall steel building by CFD

A comprehensive numerical study of wind effects on the Commonwealth Advisory Aeronautical Council (CAARC) standard tall building is presented in this paper. The techniques of Computational Fluid Dynamics (CFD), such as Large Eddy Simulation (LES), Reynolds Averaged Navier-Stokes Equations (RANS) Model etc., were adopted in this study to predict wind loads on and wind flows around the building. The main objective of this study is to explore an effective and reliable approach for evaluation of wind effects on tall buildings by CFD techniques. The computed results were compared with extensive experimental data which were obtained at seven wind tunnels. The reasons to cause the discrepancies of the numerical predictions and experimental results were identified and discussed. It was found through the comparison that the LES with a dynamic subgrid-scale (SGS) model can give satisfactory predictions for mean and dynamic wind loads on the tall building, while the RANS model with modifications can yield encouraging results in most cases and has the advantage of providing rapid solutions. Furthermore, it was observed that typical features of the flow fields around such a surface-mounted bluff body standing in atmospheric boundary layers can be captured numerically. It was found that the velocity profile of the approaching wind flow mainly influences the mean pressure coefficients on the building and the incident turbulence intensity profile has a significant effect on the fluctuating wind forces. Therefore, it is necessary to correctly simulate both the incident wind velocity profile and turbulence intensity profile in CFD computations to accurately predict wind effects on tall buildings. The recommended CFD techniques and associated numerical treatments provide an effective way for designers to assess wind effects on a tall building and the need for a detailed wind tunnel test.     

Backscattered electron SEM imaging of cells and determination of the information depth

Backscattered electron imaging of HT29 colon carcinoma cells in a scanning electron microscope was studied. Thin cell sections were placed on indium‐tin‐oxide‐coated glass slides, which is a promising substrate material for correlative light and electron microscopy. The ultrastructure of HT29 colon carcinoma cells was imaged without poststaining by exploiting the high chemical sensitivity of backscattered electrons. Optimum primary electron energies for backscattered electron imaging were determined which depend on the section thickness. Charging effects in the vicinity of the SiO₂ nanoparticles contained in cell sections could be clarified by placing cell sections on different substrates. Moreover, a method is presented for information depth determination of backscattered electrons which is based on the imaging of subsurface nanoparticles embedded by the cells.     

闪存S29AL016D在数据处理系统中的应用

S29AL016D是Spansion司生产的16Mbit闪存芯片．该芯片的擦写次数可达百万次以上，且容量大速度快、功耗低。介绍了S29AL016D并行Flash存储器的特点，给出了S29AL016D器件的几种操作方式。     

电气化高速铁路用钢丝绳的研发与生产

介绍电气化高速铁路用钢丝绳的发展概况和技术要求。研制8×29F-PWRC平行捻密实钢丝绳,PWRC结构为(8×7-1×19W)。原料采用高碳钢盘条和304不锈钢盘条,外层股、内层股、中心股直径分别为2.63,1.43,2.42 mm,给出钢丝绳中各钢丝的直径和生产工艺。所研制的直径9.50 mm钢丝绳,抗拉强度1 960MPa,最小破断拉力达到82.5 kN,与国际通用的12×7-12×3-12×3-1×19W结构电气化高速铁路用钢丝绳进行对比,展示出所研制钢丝绳结构和性能等方面的优势。     

Mirna Expression in Glaucomatous and TGFβ2 Treated Lamina Cribrosa Cells

Glaucoma is a group of optic neuropathies that leads to irreversible vision loss. The optic nerve head (ONH) is the site of initial optic nerve damage in glaucoma. ONH-derived lamina cribrosa (LC) cells synthesize extracellular matrix (ECM) proteins; however, these cells are adversely affected in glaucoma and cause detrimental changes to the ONH. LC cells respond to mechanical strain by increasing the profibrotic cytokine transforming growth factor-beta 2 (TGFβ2) and ECM proteins. Moreover, microRNAs (miRNAs or miR) regulate ECM gene expression in different fibrotic diseases, including glaucoma. A delicate homeostatic balance between profibrotic and anti-fibrotic miRNAs may contribute to the remodeling of ONH. This study aimed to determine whether modulation of miRNAs alters the expression of ECM in human LC cells. Primary human normal and glaucoma LC cells were grown to confluency and treated with or without TGFβ2 for 24 h. Differences in expression of miRNAs were analyzed using miRNA qPCR arrays. miRNA PCR arrays showed that the miR-29 family was significantly decreased in glaucomatous LC cell strains compared to age-matched controls. TGFβ2 treatment downregulated the expression of multiple miRNAs, including miR-29c-3p, compared to controls in LC cells. LC cells transfected with miR-29c-3p mimics or inhibitors modulated collagen expression.     

Superconducting Busline Design for HT—7U Tokamak

Superconducting (SC) tokamak HT-7U has seven pairs of buslines connecting toroidal/Poloidal coils and the current leads,These SC buslines(SCBLs) share a common cryostat and are made of the calbe in conduit conductors(CICCs) arranged as a decoupling configuration.In order to reduce the heat loads conducted from the seven current leads with a capacity of 15kA during the magnets cooldown.the buslines with a much lower thermal conduction were employed in comparison with the current leads,and a special cooling loop was designed.     

A Calculation of Steady Pressure Drop and an Analysis of HT—7U CICC

Under the condition of steady,the pressure drop of coolant is mainly caused by friction along the cable.in the CICC(cable-in-conduit-conductor).helium flow within the conductor consists of two parallel interconnected tubes.The velocity distribution has some differece between the central channel and conductor space.The region of Reynolds number is from 10^3 to 10^6.This paper describes the calculation of pressure drop of HT-7U CICC at various mass flows.It is assumed that the coolant flows in two parallel,rough tudes during the caclulation.     

边水油藏开发后期二类层挖潜技术研究与应用

高29断块为一边水能量较为充足的油藏,原主力层采出程度高(38％),剩余资源量较小,但存在一定数量未动用的油水层,若挖掘这部分潜力受到多种因素制约,最主要的是监测技术的滞后,导致措施风险程度大。为解决这一难题,2002年以来开展了二类层挖潜技术的研究,在历年油井措施挖潜实践中总结出综合判断开发潜力层的方法,即利用录井、井壁取芯、电测曲线特征、砂体和井间构造的高低关系等资料,进行有序的综合分析优选,最终确定挖潜井层。实施后取得了显著经济和社会效益,油藏开发水平得到显著提高。