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31.
As a global health problem, liver fibrosis still does not have approved treatment. It was proved that N-(3,4,5-trichlorophenyl)-2(3-nitrobenzenesulfonamide) benzamide (IMB16-4) has anti-hepatic fibrosis activity. However, IMB16-4 displays poor water solubility and poor bioavailability. We are devoted to developing biodegraded liposome-coated polymeric nanoparticles (LNPs) as IMB16-4 delivery systems for improving aqueous solubility, cellular uptake, and anti-fibrotic effects. The physical states of IMB16-4−LNPs were analyzed using a transmission electron microscope (TEM), high-performance liquid chromatography (HPLC), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and differential scanning calorimeter (DSC). The results show that IMB16-4−LNPs increased the drug loading compared to liposomes and enhanced cellular uptake behavior compared with IMB16-4−NPs. In addition, IMB16-4−LNPs could repress the expression of hepatic fibrogenesis-associated proteins, indicating that IMB16-4−LNPs exhibited evident anti-fibrotic effects.  相似文献   
32.
Chemical probes for chromatin reader proteins are valuable tools for investigating epigenetic regulatory mechanisms and evaluating whether the target of interest holds therapeutic potential. Developing potent inhibitors for the plant homeodomain (PHD) family of methylation readers remains a difficult task due to the charged, shallow and extended nature of the histone binding site that precludes effective engagement of conventional small molecules. Herein, we describe the development of novel proximity-reactive cyclopeptide inhibitors for PHD3—a trimethyllysine reader domain of histone demethylase KDM5A. Guided by the PHD3–histone co-crystal structure, we designed a sidechain-to-sidechain linking strategy to improve peptide proteolytic stability whilst maintaining binding affinity. We have developed an operationally simple solid-phase macrocyclization pathway, capitalizing on the inherent reactivity of the dimethyllysine ε-amino group to generate scaffolds bearing charged tetraalkylammonium functionalities that effectively engage the shallow aromatic ‘groove’ of PHD3. Leveraging a surface-exposed lysine residue on PHD3 adjacent to the ligand binding site, cyclic peptides were rendered covalent through installation of an arylsulfonyl fluoride warhead. The resulting lysine-reactive cyclic peptides demonstrated rapid and efficient labeling of the PHD3 domain in HEK293T lysates, showcasing the feasibility of employing proximity-induced reactivity for covalent labeling of this challenging family of reader domains.

We describe the development of covalent cyclic peptide ligands which target a chromatin methylation reader domain using a proximity-reactive sulfonyl fluoride moiety.  相似文献   
33.
As important biomolecules in Camellia sinensis L., amino acids (AAs) are considered to contribute to the overall green tea sensory quality and undergo dynamic changes during growth. However, limited by analytical capacity, detailed AAs composition in different growth stages remains unclear. To address this question, we analyzed the dynamic changes of 23 AAs during leaf growth in Xinyang Mao Jian (XYMJ) green tea. Using amino acid analyzer, we demonstrated that most AAs are abundant on Pure Brightness Day and Grain Rain Day. After Grain Rain, 23 AAs decreased significantly. Further analysis shows that theanine has a high level on the day before Spring Equinox and Grain Rain, accounting for 44–61% of the total free AAs content in tea leaves. Glu, Pro, and Asp are the second most abundant AAs. Additionally, spinasterol and 22,23-dihydrospinasterol are first purified and identified in ethanol extract of XYMJ by silica gel column chromatography method. This study reveals the relationship between plucking days and the dynamic changes of AAs during the growth stage and proves the rationality of the traditional plucking days of XYMJ green tea.  相似文献   
34.
The simulation of particle fluidization behavior in a complex geometry with a large number of particles is challenging owing to the complexity of unstructured c...  相似文献   
35.
Plant-parasitic nematodes infect a diversity of crops, resulting in severe economic losses in agriculture. Microbial volatile organic compounds (VOCs) are potential agents to control plant-parasitic nematodes and other pests. In this study, VOCs emitted by a dozen bacterial strains were analyzed using solid-phase microextraction followed by gas chromatography–mass spectrometry. Fumigant toxicity of selected VOCs, including dimethyl disulfide (DMDS), 2-butanone, 2-pentanone, 2-nonanone, 2-undecanone, anisole, 2,5-dimethylfuran, glyoxylic acid, and S-methyl thioacetate (MTA) was then tested against Caenorhabditis elegans. DMDS and MTA exhibited much stronger fumigant toxicity than the others. Probit analysis suggested that the values of LC50 were 8.57 and 1.43 μg/cm3 air for DMDS and MTA, respectively. MTA also showed stronger fumigant toxicity than DMDS against the root-knot nematode Meloidogyne incognita, suggesting the application potential of MTA.  相似文献   
36.
In this paper, we consider the optimization of the quantum circuit for discrete logarithm of binary elliptic curves under a constrained connectivity, focusing on the resource expenditure and the optimal design for quantum operations such as the addition, binary shift, multiplication, squaring, inversion, and division included in the point addition on binary elliptic curves. Based on the space-efficient quantum Karatsuba multiplication, the number of CNOTs in the circuits of inversion and division has been reduced with the help of the Steiner tree problem reduction. The optimized size of the CNOTs is related to the minimum degree of the connected graph.  相似文献   
37.
根据高性能计算机全天候温控的需要,提出了综合应用蒸气压缩和动力型分离式热管制冷技术的复合冷源方案。在冬季及春、秋过渡的低温季节,运行热管循环不仅大幅降低环控装置的能耗,而且可以避免在低温环境运行压缩式制冷易发生的冷启动、回油润滑等问题。提出了蒸气压缩制冷、蒸气压缩/热管复合制冷和热管制冷的分区工作模式,引入复合制冷模式有效拓宽了热管运行温区,大幅提高了制冷系统的综合COP。模拟分析了在北京地区应用热管复合制冷技术的节能性能,相比常规的压缩制冷节能率高达40%。研究表明:热管复合制冷系统具有显著的节能减排优势,特别适用于全天候工作的机房、基站等高热密度电子集成系统的温控。  相似文献   
38.
氨吸收式串联型动力/制冷复合循环   总被引:3,自引:0,他引:3  
本文提出了一种新型的采用氨水混合工质的动力/制冷复合循环,该循环以中低温工业余热或燃气轮机排气为热源,将动力、制冷子循环采用串联方式连接,基础循环工质为氨质量浓度为0.27的氨水溶液,热源为365℃/104.3 kPa 的热空气,透平进气参数为350℃/3750 kPa,,以热效率η1、(火用)效率η2作为评价准则,模拟计算表明本循环的热效率η1 为17.8%,炯效率η2为45%,通过与其它有代表性的分供系统及联供系统进行热力性能方面的比较,表明本循环η1、η2均有不同程度提高。  相似文献   
39.
孙政  陈少平  杨江锋  孟庆森  崔教林 《物理学报》2014,63(5):57201-057201
热电材料是一类能够实现热与电相互转换的功能材料,在制冷和发电领域极具应用潜力.本文采用金属Sb元素非等电子替换Cu3Ga5Te9化学式中的Cu和Te,观察到材料Seebeck系数和电导率提升的现象.这些电学性能的改善与载流子浓度和有效质量的增大及迁移率基本维持不变有关.载流子浓度的提高是由于Sb原子占位在Te晶格位置后费米能级进入到价带所产生的空穴掺杂效应所致,同时也与Cu含量减少后铜空位(V-1Cu)浓度增大相关联.另外,非等电子替换后,阴离子(Te2-)移位导致了晶格结构缺陷参数u和η的改变,其改变量fiu和fiη与材料晶格热导率(κL)的变化密切相关.在766 K时,适量的Sb替换量使材料的最大热电优值(ZT)达到0.6,比Cu3Ga5Te9提高了近25%.因此,通过选择替换元素、被替换元素及替换量有效地调控了材料的电学及热学性能,在黄铜矿结构半导体中实现了非等电子元素替换改善热电性能的思想.  相似文献   
40.
双偏振结构保偏光纤偏振器的研制   总被引:6,自引:0,他引:6  
胡永明  廖延彪  陈哲  孟洲  倪明 《光学学报》2001,21(6):41-743
提出了保偏光纤偏振器的一种串联结构,即双偏振结构,报道了研制的结果。并通过对单偏振结构和双偏振结构器件测试结果的比较,得出双偏振结构的保偏光纤偏振器可使器件达到高消光比,并且有稳定的温度特性。  相似文献   
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