Mild metal-organic-gel route for synthesis of stable sub-5-nm metal-organic framework nanocrystals

Nanoscale metal-organic frameworks (NMOFs) have attracted increased attention in recent years for miniaturized and/or biological applications.However,the synthesis of ultrasmall NMOFs with good stability is a great challenge.In this study,sub-5-nm nano-HKUST-1 was prepared for the first time via a mild metalorganic gel route without surfactants or capping agents.Controlling the gelation process via anion-ligand self-assembly is the key to the formation of NMOFs.The Tyndall effect,zeta potential,and liquid adsorption indicated strong stability of the obtained nano-HKUST-1,even in water.Adsorption experiments were performed using different dyes (crystal violet and methylene blue) to demonstrate the size-dependent adsorption thermodynamics and kinetics of this famous MOF.The results of this study provide new insights regarding the synthesis of NMOFs and their efficient applications.     

Adoption of combined detection technology of tumor markers via deep learning algorithm in diagnosis and prognosis of gallbladder carcinoma

This study was to explore the application value of back propagation (BP) neural network (BPNN) and genetic algorithm (GA) in the combined detection and prognosis of tumor markers in patients with gallbladder cancer. 446 patients with gallbladder cancer were included in the experimental group, 279 patients with benign gallbladder disease were included in the control group, and 188 healthy people were selected and included in the blank group. Serum tumor markers (CA242, CA199, CEA, and CA125) of the three groups were detected by electrochemical luminescent immune analyzer, and follow-up data for 5 years after surgery were collected. Based on BPNN and GA, an optimization algorithm for multi-tumor markers was constructed and applied to the combined detection of tumor markers in patients. The artificial neural network (ANN), dynamic network biomarker (DNB), auxiliary diagnosis algorithm of the support vector machine (SVM) based on the particle swarm optimization (PSO) (PSO-SVM), matched-pairs feature selection (MPFS) based on the machine learning, and the BPNN were introduced to compare with the algorithm constructed. The diagnostic performances of the algorithms were evaluated with the fivefold cross-validation method. The results showed that the levels of CanAg (CA) 242, carcinoma embryonic antigen (CEA), CA199, and CA125 and positive rates in the experimental group were significantly higher than those in the control group and the blank group (P?<?0.05); but the differences between control group and blank group were not visible (P?>?0.05). The sensitivity (91.72%) and specificity (87.49%) in detecting CA242 and CA199 based on the proposed algorithm were the highest; the sensitivity (0.9186), specificity (0.8622), and accuracy (94.94%) of the proposed algorithm were higher than those of the conventional algorithms. The postoperative follow-up survival rate of patients in the experimental group was reduced from 41.72% in the first year to 4.28% in the fifth year; tumor node metastasis (TNM) stage IV, neck gallbladder cancer, and CA199 were significantly correlated with the survival rate of patients in the experimental group (P?<?0.05). In summary, the combined detection technology of multiple tumor markers based on deep learning algorithms showed excellent diagnostic and prognostic performance for gallbladder cancer. The occurrence of gallbladder cancer was related to the tumor markers CA242, CA199, CEA, and CA125, showing better detection effects by combination of CA242 and CA199. The TNM stage IV, neck gallbladder cancer, and CA199 were independent risk factors for the decrease in survival rate of patients with gallbladder cancer.

     

用遗传算法实现四色图问题

遗传算法是模拟生物进化过程的算法,任何问题只要能用一组合适的编码来表示其中的一个可行解,那么这个可行解就可以看做是一个生物个体,若干个可行解就可以看做是一个生物种群。将问题的若干个可行解利用生物进化的特点,最终就可以简单快速地得到问题的一个最优解。利用遗传算法和四色图问题的这一特点,通过遗传算法实现了四色图问题的求解。实验证明,用遗传算法实现类似的四色图问题,思想简单,收敛速度快。     

三维闪存中基于钨互连的空气隙结构的制备工艺

将空气隙应用于逻辑器件后段金属互连线中可以有效降低互连线间的寄生电容,提升电路信号传输速度,但制备过程仍具有一定的困难。基于三维闪存(3D NAND)中后段(BEOL)W的自对准双重图形化(SADP)工艺,利用湿法刻蚀的方法在W化学机械平坦化(CMP)之后去除SiO_2介质层,然后再利用化学气相淀积(CVD)法淀积一层台阶覆盖率较低的介质在金属互连线层内形成空气隙。采用空气隙结构代替原来的SiO_2介质层可降低约37.4%的寄生电容,且薄膜的台阶覆盖率会进一步降低电容。TCAD仿真和电性能测试结果表明,采用该方法制备的空气隙结构可降低互连延迟。     

Extended state observer-based attitude fault-tolerant control of rigid spacecraft

In this paper, a novel fault-tolerant attitude tracking control is proposed for a rigid spacecraft with uncertain inertia matrix, actuator faults, actuator misalignment and external disturbances. The uncertainty of the inertial matrix is caused by the rotation of solar panels, payload movement and fuel consumption, and actuator faults, which include partially failed and completely failed actuators. A novel extended state observer is proposed to estimate the total uncertainties and a fast nonsingular terminal sliding-mode control scheme is proposed to get a faster, higher control precision. Strict finite-time convergence and the concrete convergence time are given. Finally, all the states of the closed-loop system are guaranteed to converge to the corresponding region in a finite time by choosing appropriate parameters. Simulation and comparison results further show the effectiveness and advantages of this method.     

非合作面部晃动情况下的心率检测

目的 心率是直接反映人体健康的重要指标之一,基于视频的非接触式心率检测在医疗健康领域具有广泛的应用前景。然而,现有的基于视频的方法不适用于复杂的现实场景,主要原因是没有考虑视频中目标晃动干扰和空间尺度特征,使得血液容积脉冲信号提取不准确,检测精度不尽人意。为了克服以上缺陷,提出一种抗人脸晃动干扰的非接触式心率检测方法。方法 本文方法主要包含3个步骤：首先,针对目标晃动干扰人脸区域选择的问题,利用判别响应图拟合检测参考图像的人脸区域及主要器官特征点,在人脸跟踪时首次引入倾斜校正思想,输出晃动干扰抑制后的人脸视频;然后,结合空间尺度的差异,采用颜色放大方法对晃动干扰抑制后的人脸视频进行时空处理,提取干净的血液容积脉冲信号;最后,考虑到小样本问题,通过傅里叶系数迭代插值的频域分析方法估计心率。结果 在人脸静止的合作情况以及人脸晃动的非合作情况下采集视频,对心率检测结果进行定量分析,本文方法在两种情况下的准确率分别为97.84%和97.30%,与经典和最新的方法相比,合作情况准确率提升大于1%,非合作情况准确率提升大于7%,表现了出色的性能。结论 提出了一种基于人脸视频处理的心率检测方法,通过有效分析人脸的晃动干扰和尺度特性,提取到干净的血液容积脉冲信号,提高了心率检测的精度和鲁棒性。     

An efficient and fast polarity optimization approach for mixed polarity Reed-Muller logic circuits

Although the genetic algorithm has been widely used in the polarity optimization of mixed polarity Reed-Muller (MPRM) logic circuits, few studies have taken into account the polarity conversion sequence. In order to improve the efficiency of polarity optimization of MPRM logic circuits, we propose an efficient and fast polarity optimization approach (FPOA) considering the polarity conversion sequence. The main idea behind the FPOA is that, firstly, the best polarity conversion sequence of the polarity set waiting for evaluation is obtained by using the proposed hybrid genetic algorithm (HGA); secondly, each of polarity in the polarity set is converted according to the best polarity conversion sequence obtained by HGA. Our proposed FPOA is implemented in C and a comparative analysis has been presented for MCNC benchmark circuits. The experimental results show that for the circuits with more variables, the FPOA is highly effective in improving the efficiency of polarity optimization of MPRM logic circuits compared with the traditional polarity optimization approach which neglects the polarity conversion sequence and the improved polarity optimization approach with heuristic technique.     

Estimation of solar-induced fluorescence using the canopy reflectance index

This article presents a methodology to quantitatively extract the solar-induced fluorescence (SIF) using the canopy reflectance index. The sensitivity analysis was conducted with a spectral vegetation Fluorescence Model (FluorMOD), and the results demonstrate that Sun zenith angle (θ), fluorescence quantum efficiency (Fi), leaf inclination distribution function (LIDF), leaf temperature (T), leaf area index, and leaf chlorophyll a + b content (chl-a+b) had large effects on the fluorescence radiance at 761 nm (LF,761). Based on the results of the sensitivity analysis, the input parameters θ, Fi, LIDF, T, and chl-a+b varied within a certain range during the generation of the simulated data. Based on the simulated data, R₇₄₀/R₆₃₀, R₆₈₅/R₈₅₀, and R₇₅₀/R₇₁₀ were thought to be the best candidates to extract the fluorescence radiation. The quantitative relationships between the fluorescence retrieved by R₇₄₀/R₆₃₀, R₆₈₅/R₈₅₀, and R₇₅₀/R₇₁₀ and LF,761 were analysed and expressed as functions of θ, Fi, T, and reflectance index. The correlation coefficients (r) between the fluorescence retrieved using R₆₈₅/R₈₅₀, R₇₄₀/R₆₃₀, and R₇₅₀/R₇₁₀ and LF,761 are 0.94, 0.95, and 0.95, respectively, and the root mean square errors (RMSEs) were 0.32, 0.29, and 0.30 W m^?2 μm^?1 sr^?1, respectively. Through comparison with FLD and 3FLD, the method presented in this article yielded better results, and could be used to estimate the fluorescence. This methodology provides new insights into the quantitative retrieval of SIF from the reflectance spectrum.     

Selenium‐Containing Polymer@Metal‐Organic Frameworks Nanocomposites as an Efficient Multiresponsive Drug Delivery System

The development of efficient multiresponsive drug delivery systems (DDSs) to control drug release has been widely explored. Herein, a facile strategy is reported that enables the micelles of the selenium‐containing polymer with the drug to be encapsulated in metal‐organic frameworks (MOFs), which serves as multiresponsive drug release by employing the selenium‐containing polymers with redox‐triggered property and the MOFs with pH‐triggered property in DDS. In this case, the micelles of selenium‐containing polymers, as core easily disassembles in the presence of redox agents, can then release the drug in MOFs matrixes. The ZIF‐8 (one type of MOFs) crystal frameworks serving as shell can collapse only under low pH conditions, and the drug can be further released. In the presence of external redox agents as well as the pH stimuli, the prepared nanocomposite (P@ZIF‐8) drug system exhibits the capability of multiresponsive release of the doxorubicin (DOX) and possesses good selectivity in releasing the DOX under low pH conditions instead of normal pH conditions. In addition, the merits of P@ZIF‐8 such as good biocompatibility, multiresponsive release properties, and especially the selective release properties under different pH conditions make the materials highly promising candidates for the realization of controlled drug delivery in tumor tissue systems.