NF-κB与肿瘤发生及药物筛选

NF-κB是一类能特异性地识别结合DNA的Rel类蛋白质二聚体转录因子。在静息细胞中 ,NF-κB与抑制性蛋白IκBs结合形成复合物 ,并被滞留于细胞质中而处于非活化状态 ;当细胞受到各种胞内外刺激时 ,IκBs被迅速地降解 ,NF-κB得以释放并进入细胞核 ,从而发挥其转录调节功能。NF-κB通过调控众多靶基因的转录表达而在免疫、炎症反应、细胞增殖与凋亡及肿瘤发生等许多生理学过程中发挥重要作用。介绍了NF-κB活化的调控机制 ,并对NF-κB信号通路在肿瘤发生等相关过程及其在药物筛选中的作用进行了探讨。     

Asymmetric somatic hybridization between wheat (Triticum aestivum) and Avena sativa L.

Common wheat is one of the most important cereal crops in the world. The improvement of its yield and quality by the introduction of heterologous gene(s) is very significant. Avena sativa L. (2n = 42), belonging to the Avena tribe, possesses resistance to drought, coldness and many dis-eases. Its contents of proteins and fat in seed, especially lysine and unsaturated fatty acid are highest in crops, therefore it is regarded as healthy food. Sexual hybridization between wheat and Avena sativa…     

利用RNA干扰技术获得晚抽薹开花转基因大白菜

LEAFY基因在植物的成花转变中起重要作用。在拟南芥中,降低LEAFY基因的表达使开花延迟,并且增加分枝。利用RNAi技术降低大白菜LEAFY基因表达,获得晚抽薹开花的转基因大白菜。开花时转基因大白菜的株高明显低于对照,而叶片数、叶面积和侧枝数则高于对照;转基因植株的LEAFY基因表达明显降低,导致大白菜抽薹开花延迟。因此可以通过降低LEAFY基因表达来延迟需低温春化作用长日植物开花。也为利用生物技术获得晚抽薹转基因大白菜提供了理论依据。     

JQ1, a BET‐bromodomain inhibitor,inhibits human cancer growth and suppresses PD‐L1 expression

Most traditional cytotoxic chemotherapeutic agents have poor aqueous solubility and significant toxicity. Hence, there is a need to develop molecule‐targeted drugs. Programmed death‐ligand 1 (PD‐L1) is associated with the prognosis of several cancer types, and blockade of PD‐1/PD‐L1 signaling increases the amplitude of anti‐tumor immunity. In the present study, we investigated the effects of JQ1, a bromodomain and extraterminal‐bromodomain inhibitor, on cell growth, and messenger RNA (mRNA) and protein levels of PD‐L1 in renal cell carcinoma primary culture cells, and prostate, liver, and lung cancer cell lines. The results of the cell counting kit‐8 assay suggested that JQ1 inhibits cell growth in a dose‐dependent manner. The mRNA and protein levels of PD‐L1 decreased in the primary culture of JQ1‐treated renal carcinoma, prostate cancer, liver cancer, and lung cancer cell lines. In addition, the mRNA level of PD‐L2 also decreased in the JQ1‐treated cells. Overall, JQ1 might be a potential anti‐tumor agent.     

Thermally Stable All‐Polymer Solar Cells with High Tolerance on Blend Ratios

Tuning the blend composition is an essential step to optimize the power conversion efficiency (PCE) of organic bulk heterojunction (BHJ) solar cells. PCEs from devices of unoptimized donor:acceptor (D:A) weight ratio are generally significantly lower than optimized devices. Here, two high‐performance organic nonfullerene BHJ blends PBDB‐T:ITIC and PBDB‐T:N2200 are adopted to investigate the effect of blend ratio on device performance. It is found that the PCEs of polymer‐polymer (PBDB‐T:N2200) blend are more tolerant to composition changes, relative to polymer‐molecule (PBDB‐T:ITIC) devices. In both systems, short‐circuit current density (J_sc) is tracked closely with PCE, indicating that exciton dissociation and transport strongly influence PCEs. With dilute acceptor concentrations, polymer‐polymer blends maintain high electron mobility relative to the polymer‐molecule blends, which explains the dramatic difference in PCEs between them as a function of D:A blend ratio. In addition, polymer‐polymer solar cells, especially at high D:A blend ratio, are stable (less than 5% relative loss) over 70 d under continuous heating at 80 °C in a glovebox without encapsulation. This work demonstrates that all‐polymer solar cells show advantage in operational lifetime under thermal stress and blend‐ratio resilience, which indicates their high potential for designing of stable and scalable solar cells.     

大鹏湾生态因子灰关联分析

研究大鹏湾夜光藻、反曲原甲藻、浮游动物种群增殖与浮游动物和海水理化因子之间的关系,采用的方法是根据它们的种群增殖态势与浮游动物和理化因子的比较,依据空间理论的数学基础,按照规范性、偶对称性、整体性和接近性这四条原则,确定参考数列（母序列：夜光藻和反曲原甲藻、浮游动物）和若干比较数列（子序列：浮游动物和海水理化因子）之间的关联度．给出各因子对母序列影响的排列次序．其结果是,对大鹏湾生态环境起主要影响的因子有浮游动物、锰、铁和溶解氧     

Source and Magnitude of Ammonium Generation in Maize Roots

Studies with ¹⁵N indicate that appreciable generation of NH₄⁺ from endogenous sources accompanies the uptake and assimilation of exogenous NH₄⁺ by roots. To identify the source of NH₄⁺ generation, maize (Zea mays L.) seedlings were grown on ¹⁴NH₄⁺ and then exposed for 3 d to highly labeled ¹⁵NH₄⁺. More of the entering ¹⁵NH₄⁺ was incorporated into the protein-N fraction of roots in darkness (approximately 25%) than in the light (approximately 14%). Although the ¹⁴NH₄⁺ content of roots declined rapidly to less than 1 μmol per plant, efflux of ¹⁴NH₄⁺ continued throughout the 3-d period at an average daily rate of 14 μmol per plant. As a consequence, cumulative ¹⁴NH₄⁺ efflux during the 3-d period accounted for 25% of the total ¹⁴N initially present in the root. Although soluble organic ¹⁴N in roots declined during the 3-d period, insoluble ¹⁴N remained relatively constant. In shoots both soluble organic ¹⁴N and ¹⁴NH₄⁺ declined, but a comparable increase in insoluble ¹⁴N was noted. Thus, total ¹⁴N in shoots remained constant, reflecting little or no net redistribution of ¹⁴N between shoots and roots. Collectively, these observations reveal that catabolism of soluble organic N, not protein N, is the primary source of endogenous NH₄⁺ generation in maize roots.     

Photo-Fenton氧化法处理废水的原理及影响因素

Photo-Fenton高级氧化技术是处理难降解有毒有机废水的一种有效的方法。本文阐述了该氧化法的原理及其影响因素,photo-Fenton氧化法在反应中会产生大量羟自由基(·OH),它是一种非常活泼及非选择性物种,其氧化电位为2.8V,氧化能力很强,能够引发水溶液中大部分有机物的氧化还原反应。其优点是操作简便及无二次污染等,反应产物Fe³⁺可与OH反应形成Fe(OH)₃沉淀而对环境无害。缺点是反应必须在pH≤3条件下进行,且H₂O₂消耗量大而导致价格昂贵,处理成本较高等。     

生境空气质量测定与评价指标

该指标系统规定了空气生境指数(Air entironment index,简称AEI)、生境空气质量分级、采样点及取值时间,采样与分析方法及数据统计的有效性规定。空气生境指数(AEI)的测定与评价的十个项目:空气洁净度(CI)、空气新鲜度(T)、植物精气浓度、人均绿地面积、绿地植物覆盖率、硬质覆盖率、水体覆盖率、界外植物覆盖率、移植植物树龄或原生植物树龄、植物种类和植物景观。本手册适用于住区生境空气质量评价。住区生境空气质量分为五级:5A级空气质量住区;4A级空气质量住区;3A级空气质量住区;2A级空气质量住区;1A级空气质量住区。