Enzyme‐Instructed Intracellular Molecular Self‐Assembly to Boost Activity of Cisplatin against Drug‐Resistant Ovarian Cancer Cells

Anticancer drug resistance demands innovative approaches that boost the activity of drugs against drug‐resistant cancers without increasing the systemic toxicity. Here we show the use of enzyme‐instructed self‐assembly (EISA) to generate intracellular supramolecular assemblies that drastically boost the activity of cisplatin against drug‐resistant ovarian cancer cells. We design and synthesize small peptide precursors as the substrates of carboxylesterase (CES). CES cleaves the ester bond pre‐installed on the precursors to form the peptides that self‐assemble in water to form nanofibers. At the optimal concentrations, the precursors themselves are innocuous to cells, but they double or triple the activity of cisplatin against the drug‐resistant ovarian cancer cells. This work illustrates a simple, yet fundamental, new way to introduce non‐cytotoxic components into combination therapies with cisplatin without increasing the systemic burden or side effects.     

Investigation of the EPR parameters and local structures for Cu2+ in Bis(l-asparaginato) M(II) catalysts (M=Zn,Cd, Mg)

The electron paramagnetic resonance (EPR) parameters (g factors and hyperfine structure constants) for Cu²⁺ in Bis(l-asparaginato) M(II) catalysts (M=Zn, Cd, Mg) are theoretically investigated using the high order perturbation formulas of these parameters for 3d⁹ ions in orthorhombically elongated octahedra. Ligand orbital and spin–orbit coupling contributions are included from the cluster approach in view of strong covalency. The ligand octahedra (i.e., [CuO₄N₂]^12? clusters) are found to experience axial and perpendicular local bond length variations Δ (≈0.19–0.25 Å) and δ (≈0.12–0.14 Å) due to the Jahn–Teller effect and size mismatch, which are dissimilar to those of host M²⁺ sites in pure compounds. The theoretical EPR parameters based on the above local structures show good agreement with the observed values, and some improvements are achieved as compared with those in the previous work. The local structures of these centers are discussed.     

A competitive immunoassay for ultrasensitive detection of Hg in water,human serum and urine samples using immunochromatographic test based on surface-enhanced Raman scattering

An immunochromatographic test (ICT) strip was developed for ultrasensitive competitive immunoassay of Hg²⁺. This strategy was achieved by combining the easy-operation and rapidity of ICT with the high sensitivity of surface-enhanced Raman scattering (SERS). Monoclonal antibody (mAb) against Hg²⁺ and Raman active substance 4-mercaptobenzoic acid (MBA) dual labelled gold nanoparticles (GNPs) were prepared as an immunoprobe. The Raman scattering intensity of MBA on the test line of the ICT strip was measured for quantitative determination of Hg²⁺. The ICT was able to directly detect Hg²⁺ without complexing due to the specific recognition of the mAb with Hg²⁺. The IC₅₀ and limit of detection (LOD) of the assay for Hg²⁺ detection were 0.12 ng mL⁻¹ and 0.45 pg mL⁻¹, respectively. There was no cross-reactivity (CR) of the assay with other nineteen ions and the ICT strips could be kept for 5 weeks without loss of activity. The recoveries of the assay for water, human serum and urine samples spiked with Hg²⁺ were in range of 88.3–107.3% with the relative standard deviations (RSD) of 1.5–9.5% (n = 3). The proposed ICT was used for the detection of Hg²⁺ in urine samples collected from Occupational Disease Hospital and the results were confirmed by cold-vapor atomic fluorescence spectroscopy (CV-AFS). The assay exhibited high sensitivity, selectivity, stability, precision and accuracy, demonstrating a promising method for the detection of trace amount of Hg²⁺ in environmental water samples and biological serum and urine samples.     

Photoinduced microchannels and element change inside silicon by femtosecond laser pulses

Microchannels are fabricated inside silicon along the direction of laser beam by a femtosecond laser at 800 nm, which is located at the absorption region of silicon. Formation mechanism of the microchannels is attributed to spherical aberration. The element change in surrounding of the microchannel is characterized, and results show that oxygen is incorporated into silicon after irradiation. The origin of the oxygen incorporation and the laser intensity dependence of the amount of oxygen are discussed, respectively.     

热粘塑性体的积分－微分型本构关系

应用　　　关于应力是五维偏应变空间变形历史的泛函的概念和Ｖａｌａｎｉｓ有关内＊时理论的描述，本文提出，对热粘塑性体，应力可设为应变、应变率和温度历史的泛函；并应用Ｍｉｌｌｅｒ和其它一些作者有关内变量演化方程的描述，由此建立了热粘塑性体的积分－微分到本构方程．这一积分－微分型本构关系大体和Ｍｉｌｌｅｒ微分型模型等价．对１０２０钢的单轴本构响应进行了数值模拟，和Ｔａｎａｋａ与Ｍｉｌｌｅｒ的分析及一些实验结果符合较好．     

复合材料层板疲劳损伤加载次序效应研究

从能量耗散的角度出发，建立了一种以有效循环滞回能为基础的非线性疲劳损伤累积法则，并从理论和实验两方面证明了该法则能够正确反映载荷次序效应     

核电工程地质(四)

核电工程地质(四)古迅(中国科学院地质研究所北京100029)6地基的勘察、试验和稳定性评价在核安全法规和有关的核安全导则中“, 核电厂的地基包括了基础结构、工程支撑结构和下卧的岩上材料(地基材料)三个部分。     

拉－扭复合加载下不锈钢的弹塑性本构关系——Ⅱ．理论

提出应力是塑性应变空间内蕴几何学参数的泛函．一般情况下，塑性应变空间是非欧几何空间，而其度量张量是塑性应变和其历史的函数，但在初始各向同性和不可压的情况下可取成欧氏空间．本文在Ｉｌｙｕｓｈｉｎ理论，和Ｖａｌａｎｉｓ理论的基础上，提出在拉－扭复合加载下的εｐ１－εｐ３空间中新的积分型弹塑性本构关系，所建理论预测的结果和实验［１］相当一致，表明理论是合理的     

CNN/Kalman技术在组导中的应用研究

经典的卡尔曼滤波器要求假设系统的动态模型和观测模型的噪声统计特性已知，而组合导航系统的噪声具有非先验性。为了解决这一问题，提出了一种新型复合神经网络(CNN)辅助卡尔曼滤波器(Kalman)。仿真试验结果表明：该辅助算法的精度与一般卡尔曼算法相比提高了2倍，收敛时间缩短近200s，并有效地克服了传统神经网络学习速度慢、泛化能力弱的缺点，使系统具有自适应能力以应付动态环境的扰动。