Rectal mucosal proliferation, dietary factors, and the risk of colorectal adenomas

OBJECTIVE: To evaluate a commercial microtiter enzyme immunoassay for antinuclear antibodies (ANA) by comparing the results of tests performed with this assay to an established indirect immunofluorescence method performed on human epitheliod cell substrate slides. DESIGN: Both analytical methods were used to test for the presence and levels of ANA in stored sera from 313 patients previously shown to have detectable ANA and from 102 healthy control subjects. Follow-up tests for specific autoantibodies (anti-dsDNA antibodies and antibodies to extractable nuclear antigens [ENA]) were performed on all sera from patients. The medical histories of all patients were reviewed to determine the presence of systemic rheumatic diseases (SRDs). Different cut-off levels of positivity were examined to determine the sensitivity and predictive values of positive results on the enzyme immunoassay for detecting patients with SRDs or sera with positive tests for specific autoantibodies. RESULTS: Among patients with clinically diagnosed SRDs (n = 197), the enzyme immunoassay was positive for ANA (> or =1 U) in 100% and the indirect immunofluorescence method was positive (titer > or =40) in 95.4% of cases. Among ANA-positive patients with no SRDs (n = 116), testing by enzyme immunoassay and indirect immunofluorescence yielded positive results in 97.6% and 75.6% of cases, respectively. Among healthy control subjects, each of the two methods was positive in 15% of cases. As expected, most patients with SRDs had higher levels of ANA than did ANA-positive patients with other clinical diagnoses. A cut-off level of > or =3 U on the enzyme immunoassay correctly classified 77% of patients with a SRD as "positive" and 88% of patients with other clinical diagnoses as "negative." The probability of detecting a positive result for specific autoantibodies on second-order testing increased directly with the level of ANA. A cut-off level of > or =3 U had a sensitivity of 92% for identifying sera with positive specific autoantibodies, and results > or =3 U had a predictive value of 52% for a positive second-order test result. CONCLUSION: Enzyme immunoassay is substantially equivalent to indirect immunofluorescence for detecting clinically important ANA. Cut-off levels for positive results on the enzyme immunoassay can be established that optimize the usefulness of this method in diagnostic algorithms for specific autoantibodies.     

HEV推进系统电机驱动选择的结果的对比研究

本文阐述了一并联混合电力驱动车辆(HEV)最合理的电力推进系统的选择的对比研究.本文基于技术状况的慎密检查,并对比了4种主要电力推进即直流(dc)电机、感应(异步)电机(IM)、永磁同步电机和整流子电机的性能.经对比研究得出主要结论,推荐笼式IM能最好满足HEV电力推进的大多数要求.     

自由曲面光学元件的设计、加工及面形测量的集成制造技术

针对自由曲面光学组件的超精密制造这门崭新技术,开发出从自由曲面光学设计、CAD连续数据转化、自由曲面模型重构、多轴加工仿真与切削优化、加工误差补偿到自由曲面面形测量的集成制造信息平台。所开发的集成技术,能有效减少在同类多轴机床编写复杂数控程序的时间,优化加工条件与切削策略,针对不同类型的自由曲面光学零件的主工艺,进行数字化仿真,避免昂贵的反复试切试验,以及提高产品的面形精度。并通过一系列的试验来验证该集成平台的稳定性和有效性。     

娱乐场所的噪声——香港酒吧的情况

许多城市居民喜欢在酒吧等娱乐场所享受快乐时光。但是,他们暴露在可能造成健康危害的娱乐场所环境中。这是因为人们逗留在酒吧时,会受到昏暗的灯光、二手烟和高噪声的影响。回顾了有关酒吧噪声的文献,并在香港的六家酒吧进行了噪声测量。分析结果显示,在欢乐时间即在5：00 pm和9：00 pm之间,酒吧声音水平（L_eq,10-min）介于66.5~79.9 dB （A）之间,酒吧声音水平在繁忙时间即10：00 pm至11：30 pm介于69.5~97.0 dB （A）之间。在欢乐时间,最高噪音水平（L_max）介于78.5~96.5 dB （A）之间,在繁忙时间介于80.9~107.8 dB （A）之间。分析发现,酒吧内的声音水平可以通过L_eq,10-min测量,酒吧内的背景噪音则可以通过L₉₀测量。     

Circular RNA,the Key for Translation

It was thought until the 1990s that the eukaryotic translation machinery was unable to translate a circular RNA. However internal ribosome entry sites (IRESs) and m⁶A-induced ribosome engagement sites (MIRESs) were discovered, promoting 5′ end-independent translation initiation. Today a new family of so-called “noncoding” circular RNAs (circRNAs) has emerged, revealing the pivotal role of 5′ end-independent translation. CircRNAs have a strong impact on translational control via their sponge function, and form a new mRNA family as they are translated into proteins with pathophysiological roles. While there is no more doubt about translation of covalently closed circRNA, the linearity of canonical mRNA is only theoretical: it has been shown for more than thirty years that polysomes exhibit a circular form and mRNA functional circularization has been demonstrated in the 1990s by the interaction of initiation factor eIF4G with poly(A) binding protein. More recently, additional mechanisms of 3′–5′ interaction have been reported, including m⁶A modification. Functional circularization enhances translation via ribosome recycling and acceleration of the translation initiation rate. This update of covalently and noncovalently closed circular mRNA translation landscape shows that RNA with circular shape might be the rule for translation with an important impact on disease development and biotechnological applications.     

Doppler coherence imaging and tomography of flows in tokamak plasmas (invited)

This article describes the results of spatial heterodyne Doppler "coherence imaging" of carbon ion flows in the divertor region of the DIII-D tokamak. Spatially encoded interferometric projections of doubly ionized carbon emission at 465 nm have been demodulated and tomographically inverted to obtain the spatial distribution of the carbon ion parallel flow and emissivity. The operating principles of the new instruments are described, and the link between measured properties and line integrals of the flow field are established. An iterative simultaneous arithmetic reconstruction procedure is applied to invert the interferometric phase shift projections, and the reconstructed parallel flow field amplitudes are found to be in reasonable agreement with UEDGE modeling.