BBX24 Interacts with DELLA to Regulate UV-B-Induced Photomorphogenesis in Arabidopsis thaliana

UV-B radiation, sensed by the photoreceptor UVR8, induces signal transduction for plant photomorphogenesis. UV-B radiation affects the concentration of the endogenous plant hormone gibberellin (GA), which in turn triggers DELLA protein degradation through the 26S proteasome pathway. DELLA is a negative regulator in GA signaling, partially relieving the inhibition of hypocotyl growth induced by UV-B in Arabidopsis thaliana. However, GAs do usually not work independently but integrate in complex networks linking to other plant hormones and responses to external environmental signals. Until now, our understanding of the regulatory network underlying GA-involved UV-B photomorphogenesis had remained elusive. In the present research, we investigate the crosstalk between the GA and UV-B signaling pathways in UV-B-induced photomorphogenesis of Arabidopsis thaliana. Compared with wild type Landsberg erecta (Ler), the abundance of HY5, CHS, FLS, and UF3GT were found to be down-regulated in rga-24 and gai-t6 mutants under UV-B radiation, indicating that DELLA is a positive regulator in UV-B-induced photomorphogenesis. Our results indicate that BBX24 interacts with RGA (one of the functional DELLA family members). Furthermore, we also found that RGA interacts with HY5 (the master regulator in plant photomorphogenesis). Collectively, our findings suggest that the HY5–BBX24–DELLA module serves as an important signal regulating network, in which GA is involved in UV-B signaling to regulate hypocotyl inhibition.     

Cisplatin Targeting of Bacterial Ribosomal RNA Hairpins

Cisplatin is a clinically important chemotherapeutic agent known to target purine bases in nucleic acids. In addition to major deoxyribonucleic acid (DNA) intrastrand cross-links, cisplatin also forms stable adducts with many types of ribonucleic acid (RNA) including siRNA, spliceosomal RNAs, tRNA, and rRNA. All of these RNAs play vital roles in the cell, such as catalysis of protein synthesis by rRNA, and therefore serve as potential drug targets. This work focused on platination of two highly conserved RNA hairpins from E. coli ribosomes, namely pseudouridine-modified helix 69 from 23S rRNA and the 790 loop of helix 24 from 16S rRNA. RNase T1 probing, MALDI mass spectrometry, and dimethyl sulfate mapping revealed platination at GpG sites. Chemical probing results also showed platination-induced RNA structural changes. These findings reveal solvent and structural accessibility of sites within bacterial RNA secondary structures that are functionally significant and therefore viable targets for cisplatin as well as other classes of small molecules. Identifying target preferences at the nucleotide level, as well as determining cisplatin-induced RNA conformational changes, is important for the design of more potent drug molecules. Furthermore, the knowledge gained through studies of RNA-targeting by cisplatin is applicable to a broad range of organisms from bacteria to human.     

Anti-Adhesive Activity of Cranberry Phenolic Compounds and Their Microbial-Derived Metabolites against Uropathogenic Escherichia coli in Bladder Epithelial Cell Cultures

Cranberry consumption has shown prophylactic effects against urinary tract infections (UTI), although the mechanisms involved are not completely understood. In this paper, cranberry phenolic compounds and their potential microbial-derived metabolites (such as simple phenols and benzoic, phenylacetic and phenylpropionic acids) were tested for their capacity to inhibit the adherence of uropathogenic Escherichia coli (UPEC) ATCC^®53503™ to T24 epithelial bladder cells. Catechol, benzoic acid, vanillic acid, phenylacetic acid and 3,4-dihydroxyphenylacetic acid showed anti-adhesive activity against UPEC in a concentration-dependent manner from 100–500 µM, whereas procyanidin A2, widely reported as an inhibitor of UPEC adherence on uroepithelium, was only statistically significant (p < 0.05) at 500 µM (51.3% inhibition). The results proved for the first time the anti-adhesive activity of some cranberry-derived phenolic metabolites against UPEC in vitro, suggesting that their presence in the urine could reduce bacterial colonization and progression of UTI.     

Polymorphismsof the CD24 Gene Are Associated with Risk of Multiple Sclerosis: A Meta-Analysis

CD24 is a cell-surface protein mainly expressed in cells of the immune and central nervous system (CNS), cells that play a critical role in the development of multiple sclerosis (MS). In the current study, we investigated four polymorphisms of the CD24 gene regarding their associations with MS. To this end, univariate and multivariate meta-analysis were applied along with modifications to include data from family-trios so as to increase the robustness of the meta-analysis. We found that the polymorphism 226 C>T (Ala57Val) of the CD24 gene is associated with MS according to the recessive mode of inheritance (odds ratio = 1.75; 95% CI: 1.09, 2.81). Moreover, the 1527–1528 TG>del polymorphism is inversely associated with MS according to the dominant mode of inheritance (odds ratio = 0.57; 95% CI 0.39, 0.83). Conversely, the 1056 A>G and 1626 A>G polymorphisms were not found to be associated with MS. We conclude that the CD24 226 C>T polymorphism increases the risk of MS, while the 1527–1528 TG>del polymorphism seems to have a protective role against MS, suggesting that these two polymorphisms can be used as predictive biomarkers for MS development.     

QXQ70/24悬臂侧取式刮板取料机行走机构改造

针对某水泥企业一台QXQ70/24悬臂式取料机运行过程中存在行走机构频繁打齿的问题,进行了详细的技术分析与思考;在此基础上,就改造中设备的选型与设计进行了讨论。按所定的方案改造后,该取料机在一年多的生产运行中,其行走机构未再发生打齿故障。     

Characterization and hydroisomerization performance of SAPO-11 molecular sieves synthesized by dry gel conversion

SAPO-11 molecular sieves were synthesized by two types of dry gel conversion (DGC) methods, namely, steam-assisted conversion (SAC) and vapor phase transport (VPT), and by conventional hydrothermal (CHT) method. The properties of these samples were characterized by XRD, XRF, SEM, N₂-adsorption, Pyridine-IR and ²⁹Si MAS NMR methods. The results show that di-n-propylamine (DPA) is a suitable structure-directing agent (SDA) for the preparation of impurity-free SAPO-11. SAPO-11 molecular sieves synthesized by SAC and VPT exhibit higher crystallinity, higher Si content and more strongly acidic sites than that synthesized by CHT. ²⁹Si MAS NMR results demonstrated that the two samples obtained by the DGC methods contain more Si(nAl)(0 < n < 4) species than that obtained by CHT. These facts suggest that the SAC and VPT methods contribute either to better Si incorporation into the AlPO₄ framework or to better Si dispersal, thus decreasing the size of Si islands and increasing the number and strength of acidic sites. The results from the hydroisomerization of n-dodecane indicate that the Pt/SAPO-11 synthesized by SAC possesses the highest hydroconversion activity and isomer yield among those three catalysts, due to the high acidity of the molecular sieve supporter.     

A12O3包覆LiNi（1/3）Co（1／3）Mn（1／3）O2

综述了A1203包覆LiNi（1/3）Cows）Mn（1/3）O2锂离子电池正极材料的研究现状与进展,并评述了其制备方法和包覆改性：讨论了包覆改善该正极材料性能的机理：提出了这种正极材料的研发过程中的一些问题并对其未来的发展前景作了展望。     

基于单片机的电能计量插座设计

介绍了一种具有电参数计量功能的基于单片机的电能计量插座。系统以AT89S51单片机为核心,计量芯片CS5460A通过采样电路完成对电能的测量,并把数据传送给单片机进行计算显示。nRF24L01+无线模块实现主机无线数据的采集和远端监控。X5045存储各项校准值和电量值,实现系统的自动校准和断电后电能值保留的功能。系统由程序实现报警和继电控制。     

两种新型24脉波整流电路

本文提出了两种新型的24脉波二极管整流电路。通过增加两个二极管和特殊的抽头均衡变压器将传统的12脉波整流电路改进成新型的24脉波整流电路，输入电流不含5、7、11、13、17、19次谐波。整流电路使用自耦变压器使得所需变压器的容量大大减少，第二种电路的自耦变压器容量(0.14Po)比第一种电路的容量(0.23Po)更小。仿真和实验结果证实两种电路的可行性     

一种半有源射频识别标签设计

针对特殊区域对于人员的进出管理和精确定位的需求,设计一款智能半有源射频识别标签。当标签进入事先安放好的线圈之内时被激活,从而与附近的读卡器进行通信,实现定位管理。标签的设计采用德州仪器公司生产的超低功耗MSP430系列单片机控制Nordic公司生产的无线信号收发模块NRF24L01来实现2.4GHz信号的发送。通过对标签的测试表明此设计可以实时发送精确定位管理信息,系统功能稳定,且在2.4GHz频段下信号的覆盖范围和较强的抗干扰能力更加适合这种对人员管理有特殊需求的环境。