Why Hydroxamates May Not Be the Best Histone Deacetylase Inhibitors—What Some May Have Forgotten or Would Rather Forget?

Hydroxamate‐based histone deacetylase inhibitors (HDACIs) have been approved as therapeutic agents by the US Food and Drug Administration for use in oncology applications. While the potential utility of such HDACIs in other areas of medicinal chemistry is tremendous, there are significant concerns that “pan‐HDAC inhibitors” may be too broadly acting and/or toxic for clinical use beyond oncology. In addition to the isozyme selectivity challenge, the potential mutagenicity of hydroxamate‐containing HDAC inhibitors represents a major hindrance in their application to other therapeutic areas. Herein we report on the mutagenicity of known hydroxamates, discuss the mechanisms responsible for their genotoxicity, and review some of the current alternatives to hydroxamates. We conclude that the hydroxamate group, while providing high‐potency HDACIs, is not necessarily the best zinc‐binding group for HDACI drug discovery.     

基于代理模型的含盐废水多级纳滤系统的过程优化设计

基于道南细孔-介电DSPM-DE模型,开展了工业含盐废水多级纳滤分离系统的代理模型构建与优化研究。首先,利用高维模型表征的数学建模方法,构建与原有纳滤理论模型有高拟合度的高精度代理模型。基于此代理模型,进一步构建膜法分盐工艺中的多级纳滤分离的数学优化模型,并以分离单位质量NaCl的比能耗为优化目标,讨论在给定设计参数的条件下进料液中[Cl^-]/[\mathrm{S}{\mathrm{O}}_{\mathrm{4}}^{\mathrm{2}-}]的变化对不同级数纳滤系统的分盐性能及最优操作条件的影响。优化结果显示,进料[Cl^-]/[\mathrm{S}{\mathrm{O}}_{\mathrm{4}}^{\mathrm{2}-}]的增加有利于提高NaCl总回收率和降低分盐比能耗。在相同的纳滤膜投资成本下,双级系统在降低能耗方面更胜一筹,与单级系统相比最高可节能5.84%。     

不同杀菌方式对泡椒鲜切马铃薯片贮藏品质的影响

为解决泡椒鲜切马铃薯片贮藏和流通过程中出现的褐变、胀袋、质地软化等问题,采用蒸汽、微波和辐照杀菌方式对泡椒鲜切马铃薯片进行处理,通过测定L*值、硬度和感官评分,筛选各杀菌方式最优工艺参数。通过贮藏实验,对比不同杀菌方式对泡椒鲜切马铃薯片色泽、质构特性、多酚氧化酶（PPO）活性及菌落总数等指标的影响。结果表明,各杀菌方式的最优工艺参数为蒸汽杀菌时间为3 min,微波杀菌功率为700 W,辐照杀菌剂量为8 kGy。贮藏实验结果表明,辐照和微波杀菌灭酶活效果优于蒸汽杀菌,但蒸汽杀菌能更好地保持产品色泽,减缓L*值的降低,维持产品硬度、弹性和咀嚼性,菌落总数和PPO活性虽比辐照处理组和微波处理组高,但整体控制在较低水平,综合感官评分以蒸汽处理组最高。综合对比,蒸汽杀菌更适合于泡椒鲜切马铃薯片的加工。     

图像增强对显著性目标检测的影响研究

目的 雾霾、雨雪天气和水下等非理想环境因素会引起图像退化,导致出现低质图像,从而影响人类主观视觉感受及机器视觉应用任务的性能,因此,低质图像被利用之前进行图像增强成为惯常的预处理过程。然而,图像增强能否提高图像机器视觉应用任务的性能及影响程度等问题鲜有系统性研究。针对上述问题,本文以图像显著性目标检测这一机器视觉应用为例,研究图像增强对显著性目标检测性能的影响。方法 首先利用包括5种传统方法、6种深度学习方法等共11种典型图像增强方法对图像进行增强处理,然后利用8种典型的显著性目标检测方法对增强前后的图像分别进行显著性目标检测实验,并对比分析其结果。结果 实验表明,图像增强对低质图像显著性目标检测方法性能的促进作用不明显,某些增强方法甚至表现出负面影响,也存在同一增强方法对不同的显著性目标检测方法作用不同的现象。结论 图像增强对于显著性目标检测及其他的机器视觉应用的实际效果值得进一步研究,如何根据图像机器视觉应用的需求来选择和设计有效的增强方法需进一步探讨。     

Poisson Ratio and Piezoresistive Sensing: A New Route to High‐Performance 3D Flexible and Stretchable Sensors of Multimodal Sensing Capability

The performance of flexible and stretchable sensors relies on the optimization of both the flexible substrate and the sensing element, and their synergistic interactions. Herein, a novel strategy is reported for cost‐effective and scalable manufacturing of a new class of porous materials as 3D flexible and stretchable piezoresistive sensors, by assembling carbon nanotubes onto porous substrates of tunable Poisson ratios. It is shown that the piezoresistive sensitivity of the sensors increases as the substrate's Poisson's ratio decreases. Substrates with negative Poisson ratios (auxetic foams) exhibit significantly higher piezoresistive sensitivity, resulting from the coherent mode of deformation of the auxetic foam and enhanced changes of tunneling resistance of the carbon nanotube networks. Compared with conventional foam sensors, the auxetic foam sensor (AFS) with a Poisson's ratio of –0.5 demonstrates a 300% improvement in piezoresistive sensitivity and the gauge factor increases as much as 500%. The AFS has high sensing capability, is extremely robust, and capable of multimodal sensing, such as large deformation sensing, pressure sensing, shear/torsion sensing, and underwater sensing. AFS shows great potential for a broad range of wearable and portable devices applications, which are described by reporting on a series of demonstrations.     

粉煤灰滤料除磷特性初探

通过静态吸附实验,研究各个外部条件对粉煤灰颗粒吸附无机磷元素效果的影响并进行实验结果对比。实验表明,当滤料投加量愈大、振荡强度愈强、浓度愈低、反应时间愈长时滤料对待处理液中磷元素的去除率愈高。在初始浓度0.2mg/L,加入2g/20mL滤料,处理45min,温度14.9℃,200r/min条件下,去除率可以达到83%,满足工业废水排放要求[1]。     

舰空导弹雷达引信抗干扰技术研究

简要介绍了舰空导弹雷达引信工作的特点，分析了在未来海战中舰空导弹雷达引信面临的典型干扰环境，给出了抗干扰的主要技术措施。     

Facile Preparation of Multifunctional WS2/WOx Nanodots for Chelator‐Free 89Zr‐Labeling and In Vivo PET Imaging

While position emission tomography (PET) is an important molecular imaging technique for both preclinical research and clinical disease diagnosis/prognosis, chelator‐free radiolabeling has emerged as a promising alternative approach to label biomolecules or nanoprobes in a facile way. Herein, starting from bottom‐up synthesized WS₂ nanoflakes, this study fabricates a unique type of WS₂/WO_x nanodots, which can function as inherent hard oxygen donor for stable radiolabeling with Zirconium‐89 isotope (⁸⁹Zr). Upon simply mixing, ⁸⁹Zr can be anchored on the surface of polyethylene glycol (PEG) modified WS₂/WO_x (WS₂/WO_x‐PEG) nanodots via a chelator‐free method with surprisingly high labeling yield and great stability. A higher degree of oxidation in the WS₂/WO_x‐PEG sample (WS₂/WO_x (0.4)) produces more electron pairs, which would be beneficial for chelator‐free labeling of ⁸⁹Zr with higher yields, suggesting the importance of surface chemistry and particle composition to the efficiency of chelator‐free radiolabeling. Such ⁸⁹Zr‐WS₂/WO_x (0.4)‐PEG nanodots are found to be an excellent PET contrast agent for in vivo imaging of tumors upon intravenous administration, or mapping of draining lymph nodes after local injection.     

岩巷快速掘进技术研究

结合祁东煤矿南部运输石门实例,通过优化运输方式、施工工艺、爆破参数等来提高岩巷单进水平,实现巷道快速掘进.     

Comparison of ultrasonication and microfluidization for high throughput and large-scale processing of SWCNT dispersions

Two SWCNT dispersion processing techniques - microfluidization and ultrasonication- were examined using an ultracentrifuge method and simultaneous Raman scattering and photoluminescence spectroscopy. It was demonstrated that the extremely high energy dissipation rate in microfluidization facilitates the high throughput dispersion of SWCNT bundles. However, the efficiency of SWCNT bundles being separated into individual tubes in this process is much lower compared to ultrasonication, in which the energy dissipation rate is very low. This suggests that the types of flow field rather than the energy dissipation rate play a critical role in the separation of bundles into single SWCNTs.