氮钾营养与花椰菜氮素代谢和产量的初步研究

采用４种不同氮钾营养处理研究了花椰菜叶片硝酸盐的还原作用，硝酸还原酶活性与花球产量的关系，结果表明，以Ｎ８Ｋ１０处理植株生物较好，花球产量与单位叶面积商品生产率最高，Ｎ８Ｋ５，Ｎ１５Ｋ１０和Ｎ１０Ｋ５处理依次降低，植株不同叶位叶片的ＮＲ活性自下而上逐渐提高。氮钾交互作用明显地影响叶和ＮＲ活性和ＮＯ３＾－—Ｎ含量。增氮显著地提高ＮＲ活性，降低ＮＯ３＾－—Ｎ含量，低氮时增钾提高ＮＲ活性，降低ＮＯ３＾－     

Optimizing rice paddies’ lower greenhouse gas emissions and higher yield with SRI management under varying water table levels

Paddy and Water Environment - The System of Rice Intensification (SRI) is known as a climate-smart agricultural practice that increases rice production by changing the management of plants, soil,...     

DPC系统化控对麦套春棉生理特性的影响

研究结果表明，ＤＰＣ系统化控能使麦套春棉根系伤流中游离氨基酸总量及无机磷含量明显增加，根系活力增强；叶片中游离脯氨酸含量和叶绿素含量及叶绿素ａ／ｂ值提高，棉株抗旱性增强和光合作用提高；发育的棉铃中蔗糖和可溶性糖水平降低，加速了光合产物向棉铃中运输的速度。     

两种原核表达载体对CsPPO蛋白表达活性的影响

为了选择合适载体,获得稳定表达且具有高活性的可溶性茶树多酚氧化酶,本研究以茶树叶片为材料,克隆茶树多酚氧化酶基因（CsPPO）,切除含43个氨基酸和70个氨基酸的肽段后分别与pET32a载体、pMAL-c5X载体进行重组构建原核表达载体,分别命名为pET32a-CsPPO₄₃、pET32a-CsPPO₇₀、pMALc5X-Cs PPO₄₃、pMALc5X-CsPPO₇₀,利用E. coil Transetta（DE3）菌株进行表达,经SDS-PAGE电泳检验,pMAL-c5X载体表达的目的蛋白易于提取,大量出现在上清液中;而pET32a载体表达后蛋白则基本存在于沉淀中。利用邻苯二酚、ECG、EC 3种底物在410βnm处检测CsPPO蛋白活性发现,pMALc5X-CsPPO对不同底物反应时酶活性随时间增加均呈现明显“S”型变化,表明茶树PPO氧化儿茶素类的反应并不是匀速过程。pMALc5X-CsPPO₄₃比活力比pMALc5X-CsPPO₇₀的高,其中pMALc5X-CsPPO₄₃与EC反应时酶比活力最高,最大比活力为1.45×10⁶β U·mg^-1。因此,可利用pMALc5X-CsPPO₄₃合成工业用PPO,为进一步研究其与儿茶素的反应机理,利用体外酶法高效获得茶黄素奠定基础。     

Identification of Antiviral Agents Targeting Hepatitis B Virus Promoter from Extracts of Indonesian Marine Organisms by a Novel Cell-Based Screening Assay

The current treatments of chronic hepatitis B (CHB) face a limited choice of vaccine, antibody and antiviral agents. The development of additional antiviral agents is still needed for improvement of CHB therapy. In this study, we established a screening system in order to identify compounds inhibiting the core promoter activity of hepatitis B virus (HBV). We prepared 80 extracts of marine organisms from the coral reefs of Indonesia and screened them by using this system. Eventually, two extracts showed high inhibitory activity (>95%) and low cytotoxicity (66% to 77%). Solvent fractionation, column chromatography and NMR analysis revealed that 3,5-dibromo-2-(2,4-dibromophenoxy)-phenol (compound 1) and 3,4,5-tribromo-2-(2,4-dibromophenoxy)-phenol (compound 2), which are classified as polybrominated diphenyl ethers (PBDEs), were identified as anti-HBV agents in the extracts. Compounds 1 and 2 inhibited HBV core promoter activity as well as HBV production from HepG2.2.15.7 cells in a dose-dependent manner. The EC₅₀ values of compounds 1 and 2 were 0.23 and 0.80 µM, respectively, while selectivity indexes of compound 1 and 2 were 18.2 and 12.8, respectively. These results suggest that our cell-based HBV core promoter assay system is useful to determine anti-HBV compounds, and that two PBDE compounds are expected to be candidates of lead compounds for the development of anti-HBV drugs.     

Model-based maximum covariance analysis for irregularly observed climatological data

In climatology, maximum covariance analysis (MCA) is one of the most popular tools for investigating association between two multivariate variables across time and space. These association studies are important because many climate phenomena such as the El Niño-Southern Oscillation (ENSO) and the North Atlantic Oscillation are results of interaction between these variables. Despite its popularity, maximum covariance analysis does not provide straightforward statistical inference on its estimates and furthermore it does not provide an objective way to handle irregularly observed data, frequently encountered in climatology. The aim of this article is to describe a modelbased maximum covariance analysis that can accommodate irregularly observed data. The methodology combines maximum covariance analysis’s relationship with Tucker inter-battery factor analysis and the state-space methodology for missing data. The methodology is illustrated with an application to investigate association between Irish winter precipitation and global sea surface temperature (SST) anomalies.     

蔓生长豇豆的生长与结荚特性

以蔓生长豇豆锦穗白豆角和新青青豆角为试材,研究其生长动态、叶面积形成、净同化率（ＮＡＲ）和豆荚产量形成等。结果表明,两个品种生育过程中植株和各个器官的生长动态均呈Ｓ形曲线变化。锦穗白豆角的生长量和叶面积都比新青青豆角大。两品种的ＮＡＲ在营养生长过程都较低,生殖生长过程则提高。新青青豆角的ＮＡＲ比锦穗白豆角稍高。两个品种的结荚能力和豆荚产量无明显差异,豆荚产量形成呈Ｓ形曲线变化。     

Proteopolymersomes: in vitro production of a membrane protein in polymersome membranes

Polymersomes are stable self-assembled architectures which mimic cell membranes. For characterization, membrane proteins can be incorporated into such bio-mimetic membranes by reconstitution methods, leading to so-called proteopolymersomes. In this work, we demonstrate the direct incorporation of a membrane protein into polymersome membranes by a cell-free expression system. Firstly, we demonstrate pore formation in the preformed polymersome membrane using α-hemolysin. Secondly, we use claudin-2, a protein involved in cell-cell interactions, to demonstrate the in vitro expression of a membrane protein into these polymersomes. Surface plasmon resonance (Biacore) binding studies with the claudin-2 proteopolymersomes and claudin-2 specific antibodies are performed to show the presence of the in vitro expressed protein in polymersome membranes.     

Growth of Amazon ornamental fish Nannostomus beckfordi larvae (Steindachner, 1876) submitted to different stocking densities and feeding management in captivity conditions

The study evaluated productive performance of larvae Nannostomus beckfordi submitted to feeding management (Experiment one) and different stock density (Experiment two) in captivity conditions. The first experiment evaluated feeding rate (100 and 200 nauplii of artemia larvae^?1 day^?1) and feeding frequency (2 and 4× per day). Second experiment evaluated different stock density (1, 5, 10, 20, 40 larvae per litre). At the end of 15 days, for both experiment, the survival and productive performance such as total length (TL), final weight (FW), specific development rate (SDR), specific growth rate (SGR), uniformity for weight (UW) uniformity for length (UL) and relative condition factor (Kr) was determined. For the main results, there is no significant difference to the rate and feeding frequency. The stock density has no significant difference for UW, Kr and survival. Nonetheless, a reduction in the TL, FW, SDR, SGR and FW with the increase in density (20 for 40 larvae per litre) was observed. Thus, for this species Nannostomus beckfordi during to initial stage using exogenous feeding, it is recommended 20 larvae per litre fed with 100 nauplii per larvae having two meals per day.     

Effect of moisture content on manufacturing cement-bonded particleboard using supercritical CO<Subscript>2</Subscript>

This study examined the effects of moisture content (MC) on the manufacture of cement-bonded particleboard (CBP) using supercritical CO₂ in the curing process. Significant correlations were found between MC and the performance of CBP: the internal bond strength, modulus of rupture, and modulus of elasticity values of CBP achieved their maximums, when the MC of boards was approximately 30%. This finding indicated that during the curing phase of manufacturing CBP, a MC of about 30%, which is nearly equal to the water–cement (w/c) ratio of about 0.34, contributes to improved mechanical properties. However, the mechanical properties decreased when the MC was below 30%, which had a negative effect on board performance, indicating that carbon dioxide could not fully react and no carbonation occurred during the curing process. Maintaining a MC of approximately 30% as an ordinary condition of the cement required in the curing of CBP could promote the reaction of carbon dioxide to form calcium carbonate (CaCO₃), which leads to increased final strength of CBP. Both X-ray diffractometry and thermal gravimetry observation agreed well with these results and clarified that the increase of CaCO₃ content caused by carbonation with increased MC of boards contributed to improving the mechanical properties of CBP.