氡子体比的现场测量及其对剂量转换系数的影响

氡子体比是指其短寿命子体218 Po、214 Pb、214 Bi的活度浓度的比值,是氡子体剂量评价中的重要参数,但环境中氡子体比的数据非常有限。为了解和把握城市典型环境中氡子体比的现状,并分析其对剂量转换系数的影响,本文利用便携式α谱仪,现场测量了城市典型室内外环境的氡子体比,并通过分析室内外环境氡子体比数据的特点,讨论了环境氡子体比对剂量转换系数的影响。测量结果显示,城市典型室内环境中氡子体比的平均值为1∶0.59∶0.58,典型室外环境中氡子体比的平均值为1∶0.50∶0.67。因各子体的剂量系数与它们的α潜能呈正比,所以氡子体比对剂量转换系数的影响很小。     

基于甲胎蛋白抗体和巯基丁二酰胺铜(II)共固定修饰电极的人血清中甲胎蛋白免疫传感器

研制基于甲胎蛋白抗体(Ab-AFP)和巯基丁二酰胺铜(Ⅱ)(CuL)共固定修饰玻碳电极(GCE|Ab-AFP/TiO2/CuL)的免疫传感器,用于测定人血清中AFP抗原水平。该免疫传感器是利用溶胶-凝胶气相沉积技术,将AFP抗体分子固定在CuL修饰玻碳电极表面制备而成。电极表面的CuL具有电活性,对H2O2有良好的电化学还原催化。当该免疫传感器在含AFP样品的溶液中于25℃温育30min后,AFP抗原与Ab-AFP抗体分子的免疫结合物导致CuL的电子传递被部分阻碍,使CuL对H2O2电催化还原的效率降低,电流值的下降量和AFP浓度成正比,可用于AFP定量测定。在pH=6的PBS中,25℃温育30min的优化条件下,该传感器对AFP的检测线性范围为0.5～3.9和3.9～100ng/mL,检出下限为0.081ng/mL(3σ)。该免疫传感器制备过程比基于酶标抗体修饰传感器简单,尤其是对H2O2催化响应迅速,稳定性好,可以在磷酸盐缓冲溶液中稳定存放15d。对于构建无试剂的免疫传感器和临床免疫分析提供了一种新颖的方法。     

水平井喷砂射孔填砂压裂工具冲蚀规律

连续管携带的压裂工具串冲蚀十分严重,制约了水平井喷砂射孔填砂压裂工艺作业效率及推广应用.为此,通过观察现场压裂作业后井下工具串的冲蚀形态,确立了工具主要冲蚀区域的结构特征,通过数值模拟对3种易冲蚀结构进行冲蚀机理研究,找出了冲蚀速率的影响因素,提出了压裂工具的优化思路.研究结果表明:压裂工具在环空高速携砂液冲蚀下会在其...     

Two-Stage Robust Optimization Under Decision Dependent Uncertainty

In the conventional robust optimization(RO)context, the uncertainty is regarded as residing in a predetermined and fixed uncertainty set. In many applications, however,uncertainties are affected by decisions, making the current RO framework inapplicable. This paper investigates a class of twostage RO problems that involve decision-dependent uncertainties.We introduce a class of polyhedral uncertainty sets whose righthand-side vector has a dependency on the here-and-now decisions and seek to deri...     

Evaluation of stability and functionality of BaCe1–x Inx O3–δelectrolyte in a wider range of indium concentration

The properties of BaCe_1–xIn_xO_3–δ(x=0.05,0.10,0.15,0.20,0.25,0.30,0.35,and 0.40) as proton conducting electrolyte are examined.The dense electrolyte is formed after sintering at 1300℃for 5 h in air.The samples with In content≥25 mol%contain In₂O₃ as a secondary phase.The highest total conductivity is around 5×10^–3 S/cm for BaCe_0.75In_0.25O_3–δ in the wet hydrogen atmosphere at 700℃.After exposure to p...     

Bidirectional intensity modulated/direct detection optical OFDM WDM-PON system

In this paper, we have evaluated a bidirectional wavelength division multiplexing passive optical network(WDM-PON) employing intensity modulated/direct detection optical orthogonal frequency division multiplexing(IM/DD-OFDM). The proposed system employs 100 Gbit/s 16 quadrature amplitude modulation(16-QAM) downstream and 5 Gbit/s on-off keying(OOK) upstream wavelengths, respectively. The proposed system is considered low-cost as non-coherent IM/DD OFDM technology and a simple reflective semicond...     

Multiplexed Biosensing Diagnostic Platforms Detecting Autoantibodies to Tumor-Associated Antigens from Exosomes Released by CRC Cells and Tissue Samples Showed High Diagnostic Ability for Colorectal Cancer

Colorectal cancer (CRC) is the second leading cause of cancer-related death worldwide. The five-year survival rate of CRC patients depends on the stage at diagnosis, being higher than 80% when CRC is diagnosed in the early stages but lower than 10% when CRC is diagnosed in advanced stages. Autoantibodies against specific CRC autoantigens (tumor-associated antigens (TAAs)) in the sera of patients have been widely demonstrated to aid in early diagnosis. Thus, we herein aim to identify autoantigens target of autoantibodies specific to CRC that possess a significant ability to discriminate between CRC patients and healthy individuals by means of liquid biopsy. To that end, we examined the protein content of the exosomes released by five CRC cell lines and tissue samples from CRC patients by means of immunoprecipitation coupled with mass spectrometry analysis. A total of 103 proteins were identified as potential autoantigens specific to CRC. After bioinformatics and meta-analysis, we selected 15 proteins that are more likely to be actual CRC autoantigens in order to evaluate their role in CRC prognosis by Western blot (WB) and immunohistochemistry (IHC). We found dysregulation at the protein level for 11 of these proteins in both tissue and plasma exosome samples from patients, along with an association of nine of these proteins with CRC prognosis. After validation, all but one showed a statistically significant high diagnostic ability to distinguish CRC patients and individuals with premalignant lesions from healthy individuals, either by luminescence Halotag-based beads, or by a multiplexed biosensing platform involving the use of magnetic microcarriers as solid support modified with covalently immobilized Halotag fusion proteins constructed for CRC detection. Taken together, our results highlight the usefulness of the approach defined here to identify the TAAs specific to chronic diseases; they also demonstrate that the measurement of autoantibody levels in plasma against the TAAs identified here could be integrated into a point-of-care (POC) device for CRC detection with high diagnostic ability.     

重新激活回忆诱导神经元有助于远期恐惧记忆的减轻

正恐惧的减轻是通过新的安全记忆痕迹抑制原始的恐惧记忆痕迹来调节,还是通过将原始的恐惧痕迹更新为安全痕迹来调节,一直是神经科学和心理学领域一个长期存在的问题。尤其哪一种情况决定了远期(以月计算)恐惧记忆的减弱仍然是完全未知的,即便在长期忍受精神创伤的背景下,人们有足够的动力去更好地理解这个过程。     

Improved Cohen?Sutherland algorithm for TGS transmission imaging

Tomographic gamma scanner (TGS), an advanced γ-ray nondestructive analysis technique, can locate and analyze nuclides in radioactive nuclear waste, and TGS can be categorized into two processes:e.g., transmission measurement and emission measurement.Specifically,transmissionmeasurementsprovidethebasisforaccuratemeasurementofnonuniform radionuclide content in TGS scanning. The scan data were obtained using the Monte Carlo tool Geant4 simulation, and 25voxels were divided into five lengths and fiv...     

Bayesian inference of the crust–core transition density via the neutron?star radius and neutron?skin thickness data

In this work, we perform a Bayesian inference of the crust–core transition densityρt of neutron stars based on the neutronstar radius and neutron-skin thickness data using a thermodynamical method. Uniform and Gaussian distributions for the ρ_t prior were adopted in the Bayesian approach. It has a larger probability of having values higher than 0.1 fm^-3 for ρ_t as the uniform prior and neutron-star radius data were used. This was found to be controlled by the curva...