Synthesis and application of a targeting diagnosis system via quantum dots coated by amphiphilic polymer for the detection of liver cancer cells

Water‐soluble quantum dots (QDs) for liver cancer diagnosis were prepared using QDs with oleylamine ligand coated with poly(aspartate)–graft–poly(ethylene glycol)–dodecylamine (PASP–Na–g–PEG–DDA). Dynamic light scattering and transmission electron microscopy imaging showed that the novel QDs have an ellipsoidal morphology with a size of ~ 45 nm which could be used for biomedical application. Furthermore, the PASP–Na–g–PEG–DDA was then modified with anti‐(vascular endothelial growth factor) (VEGF antibody), and a 1‐(4,5‐dimethylthiazol‐2‐yl)‐3,5‐diphenylformazan (MTT) assay showed that the novel anti‐VEGF‐targeting QDs in vitro had low toxicity. Confocal laser scanning microscopy observations revealed an intracellular (HepG2) distribution of the novel anti‐VEGF‐targeting QDs and the targeting efficiency of anti‐VEGF. These novel QDs could be used as a probe for liver cancer cell imaging because of anti‐VEGF targeting. Copyright © 2014 John Wiley & Sons, Ltd.     

miR-10a Regulates Proliferation of Human Cardiomyocyte Progenitor Cells by Targeting GATA6

microRNAs (miRNAs) play essential roles in cardiogenesis. The altered expression of miRNAs can result in cardiac malformations by inducing abnormalities in the behavior of cardiac cells. However, the role of miR-10a in the regulation of cardiomyocyte progenitor cells (CMPCs) remains undetermined. In the present study, we found that up- or down-regulation of miR-10a inhibited or promoted the proliferation of human CMPCs, respectively, without affecting their differentiation toward cardiomyocytes. miR-10a bound to GATA6 directly and reduced GATA6 expression. Over-expression of GATA6 greatly attenuated the miR-10a-mediated inhibitory effect on the proliferation of human CMPCs. Thus, our results indicate that miR-10a could effectively modulate the proliferation of human CMPCs by targeting GATA6. The finding provides novel insights into the potency of miR-10a during heart development.     

Changes in forest biomass and linkage to climate and forest disturbances over Northeastern China

The forests of northeastern China store nearly half of the country's total biomass carbon stocks. In this study, we investigated the changes in forest biomass by using satellite observations and found that a significant increase in forest biomass took place between 2001 and 2010. To determine the possible reasons for this change, several statistical methods were used to analyze the correlations between forest biomass dynamics and forest disturbances (i.e. fires, insect damage, logging, and afforestation and reforestation), climatic factors, and forest development. Results showed that forest development was the most important contributor to the increasing trend of forest biomass from 2001 to 2010, and climate controls were the secondary important factor. Among the four types of forest disturbance considered in this study, forest recovery from fires, and afforestation and reforestation during the past few decades played an important role in short‐term biomass dynamics. This study provided observational evidence and valuable information for the relationships between forest biomass and climate as well as forest disturbances.     

变溶菌素(Mutanolysin)研究历史和发展前景

变溶菌素(Ｍｕｔａｎｏｌｙｓｉｎ)是由球孢链霉菌(Ｓｔｒｅｐｔｏｍｙｃｅｓｇｌｏｂｉｓｐｏｒｕｓ)的培养液制备的由多种不同溶菌酶组成的粗酶液。这种溶菌酶群在防治龋齿、从细菌细胞壁制取免疫活性物质等方面及一些科研领域有着良好的应用前景,其研究越来越受到广泛?..     

Ginsenoside Rh2 alleviates dextran sulfate sodium-induced colitis via augmenting TGFβ signaling

Ginsenoside Rh2 (GRh2) has been reported to have therapeutic effects on various diseases. However, whether it may also affect the recovery from ulcerative colitis remains unknown. Here we induced colitis in mice by dextran sulfate sodium (DSS) administration, and then treated the mice with GRh2. We found that GRh2-treated mice showed significant alleviation of the DSS-induced colitis. Moreover, significant increase in the activity of TGFβ signaling was detected in the GRh2-treated colon that had received DSS. To investigate whether there is a causative link among GRh2 treatment, TGFβ signaling augment and the cure of colitis, we gave the DSS-treated mice a combination of GRh2 and a specific TGFβ receptor I inhibitor, SB431542. SB431542 significantly decreased the activation of TGFβ signaling in the colon from the GRh2-administrated mice, and consequently attenuated the therapeutic effect of GRh2. Our data thus demonstrate that GRh2 may alleviate DSS-induced colitis via augmenting TGFβ signaling.     

黄河流域旅游生态效率时空演变及空间溢出效应——基于73个城市数据的分析

黄河流域旅游生态效率时空演变及空间溢出效应研究，有利于优化旅游资源要素投入，推动黄河流域生态保护及高质量发展。基于超效率SBM模型测算2010-2019年黄河流域73个城市旅游生态效率，借助ArcGIS软件描绘时空演化轨迹，并构建空间杜宾模型揭示空间溢出效应。结果表明：（1）黄河流域旅游生态效率时序上呈现先上升后下降的阶段性特征，空间上呈现"下游-中游-上游"阶梯式递减的异质性特征；（2）旅游生态效率分布具有明显的空间集聚与依赖特征，低水平同质化现象显著；（3）空间溢出效应显著，政府干预、市场规模对邻近城市旅游生态效率具有正向溢出效应，经济发展、产业结构、交通可达性对邻近城市旅游生态效率具有负向溢出效应。基于实证分析结果，提出制定差异化、互补性旅游发展策略，加强区域旅游战略合作，发挥邻近区域辐射带动作用，优化城市空间溢出效应的建议。     

基于转录组的楠木MYB转录因子的挖掘及分析

楠木(Phoebe zhennan)为樟科常绿乔木,是国家二级重点保护树种。楠木生长缓慢,木材形成所需周期较长,其原因有待进一步深入分析。近年来转录因子已成为植物分子生物学研究的热点,高通量测序技术的应用和发展促进了转录因子的挖掘和深入分析。该研究基于我国特有濒危树种楠木的转录组数据,通过与拟南芥基因组MYB转录因子进行对比,对楠木MYB转录因子进行挖掘和生物信息学分析,并结合功能预测和不同组织表达对其进行深入分析。结果表明:从楠木转录组数据中,共挖掘出82个MYB转录因子,这82个MYB转录因子蛋白质所含氨基酸数目为50~1 121个、分子量为5.907~123.64 k Da,整体表现为亲水性不稳定蛋白,以α-螺旋和无规则卷曲为主要二级结构元件。序列比对和进化树分析表明,楠木MYB转录因子的结构域有高度保守性,含有[W]-X(19)-[W]-X(19)结构;82个Pz MYB可分为22类,参与生长发育、次生代谢、逆境响应等过程,与功能预测分析结果相一致。同时,在楠木茎和叶中,差异表达Pz MYB数目为18个,其中上调10个、下调8个。该研究结果不仅对楠木MYB转录因子的挖掘和功能分析以及分子生物学研究奠定了基础,而且还对其遗传改良和分子育种具有参考价值。     

拟青霉酶系酶解花生酱渣二次提油的探讨

花生酱渣是花生油脂厂的下脚料,其中约含５．５％的油脂。用拟青霉酶系酶解其细胞壁可将油脂释放出胞外。以花生酱渣为底物,拟青霉酶系作用的最适ｐＨ为５．５,最适温度为５５℃。提油后的酱渣中加入３倍的酶液（０．４ｍｇ粗酶粉／ｍｌ）,１２０ｒ／ｍｉｎ、５５℃保温振荡２ｈ,酶解率达６０％,二次提油率为４．４％。再延长酶解时间和加大酶的用量,酶解率和出油率都提高甚微。     

7号淀粉酶链霉菌M1033木糖异构酶基因的启动子活性检测、转录起始点的确定

分别从重组质粒ｐＵＢ１及其Ｍ（１３）亚克隆Ｓ１中将７号淀粉酶链霉菌（ＳｔｒｅｐｔｏｍｙｃｅｓｄｉａｓｔａｔｉｃｕｓＮｏ．７）Ｍ１０３３（以下简称Ｓ．ｄｉ．Ｍ１０３３）木糖异构酶基因的－１９２－＋５８１ｂｐ片段克隆入链霉菌启动子探测质粒ｐＩＪ４０８３中,转化变铅青链霉菌（Ｓ．ｌｉｖｉｄａｎｓ）ＴＫ２４。通过对其邻苯二酚加双氧酶活性的检测表明,该片段具有启动子活性。应用Ｍ１３亚克隆Ｓ１和合成引物Ｐ６延伸制备放射性标记的单链ＤＮＡ探针;通过Ｓ．ｄｉ．Ｍ１０３３的总ＲＮＡ的Ｓ１核酸酶保护实验,确定了其转录的起始位点,并由此探讨了与木糖异构酶基因表达有关的一些因素。