免耕与土壤侵蚀研究进展

综述了国内外免耕控制土壤侵蚀的机理研究以及对土壤性质的影响,并提出免耕在我国的应用方向。     

Design, synthesis, insecticidal activity and structure-activity relationship of 3,3-dichloro-2-propenyloxy-containing phthalic acid diamide structures

BACKGROUND: Phthalic acid diamide derivatives are among the most important classes of synthetic insecticides. In this study, a 3,3‐dichloro‐2‐propenyloxy group, the essential active group of pyridalyl derivatives, was incorporated into phthalic acid diamide derivatives with the aim of combining the active groups to generate more potent insecticides. RESULTS: Thirty‐one new phthalic acid diamides were obtained, and these were characterised by ¹H and ¹³C NMR. The structure of N²‐[1,1‐dimethyl‐2‐(methoxy)ethyl]‐3‐iodo‐N¹‐[4‐(3,3‐dichloro‐2‐propenyloxy)‐3‐(trifluoromethyl)phenyl]‐1,2‐benzenedicarboxamide was determined by X‐ray diffraction crystallography. The insecticidal activities of the compounds against Plutella xylostella were evaluated. The title compounds exhibited excellent larvicidal activities against P. xylostella. Structure‐activity relationships revealed that varying the combination of aliphatic amide and aromatic amide moieties, or the nature and position of substituent Y on the aniline ring, could aid the design of structures with superior performance. CONCLUSION: A series of novel phthalic acid diamides containing a 3,3‐dichloro‐2‐propenyloxy group at the 4‐position of the aniline ring were designed and synthesised. Structure‐activity relationships with the parent structure provided information that could direct further investigation on structure modification. Copyright © 2012 Society of Chemical Industry     

Induction of apoptosis by vitamin D2, ergocalciferol, via reactive oxygen species generation, glutathione depletion, and caspase activation in human leukemia Cells

This study demonstrated that ergocalciferol was able to inhibit leukemia cell growth in a concentration-dependent manner. Exploration of the acting mechanisms involved this event revealed that ergocalciferol induced DNA fragmentation and increased sub-G1 DNA contents in HL-60 cells, both of which are hallmarks of apoptosis. Analysis of the integrity of mitochondria demonstrated that ergocalciferol caused loss of mitochondrial membrane potential with release cytochrome c to cytosol, generation of reactive oxygen species (ROS), and depletion of glutathione (GSH), suggesting that ergocalciferol may induce apoptosis in HL-60 cells through a ROS-dependent pathway. Further results show that caspases-2, -3, -6, and -9 were all activated by ergocalciferol, together with cleavage of the downstream caspase-3 targets, DNA fragmentation factor (DFF-45), and poly(ADP-ribose) polymerase. In addition, ergocalciferol led to the increase in pro-apoptotic factor Bax accompanied with the decrease in anti-apoptotic member Mcl-1, and the reduced Mcl-1 to Bax ratio may be a critical event concerning mitochondrial decay by ergocalciferol. Furthermore, ergocalciferol also led to induction of Fas death receptor closely linked to caspase-2 activation, suggesting the involvement of a Fas-mediated pathway in ergocalciferol-induced apoptosis. Totally, these findings suggest that ergocalciferol causes HL-60 apoptosis via a modulation of mitochondria involving ROS production, GSH depletion, caspase activation, and Fas induction. On the basis of anticancer activity of ergocalciferol, it may be feasible to develop chemopreventive agents from edible mushrooms or hop.     

Immunomodulatory effects of β-glucans on porcine alveolar macrophages and bone marrow haematopoietic cell-derived dendritic cells

The immunopharmacological activities of β-glucans with a backbone of β-1,3/β-1,6-linkages associated with anti-tumor, anti-viral, bacterial and fungal infections have been well documented. Dectin-1, a specific pattern recognition receptor for β-1,3/β-1,6-glucans, is expressed mainly on phagocytes, especially macrophages and dendritic cells (DCs). In this study, the encoding nucleotide for the carbohydrate-recognition domain (CRD) of porcine dectin-1 was sequenced for the first time, and the immunomodulatory functions of a synthetic particulate β-glucan (p-β-glucan) were examined. Results showed that p-β-glucan significantly enhanced cell activity and phagocytosis in porcine alveolar macrophages (AMs), immature DCs (imDCs) and mature DCs (mDCs), in a similar way to zymosan. Zymosan enhanced dectin-1/TLR2/TLR4 expression and TNF-α/IL-10 production in all of three types of cell, whereas p-β-glucan increased dectin-1/TLR4 and TNF-α/IL-12 production in AMs but inhibited IL-10 in mDCs. These results indicate that the complex collaborating interactions between dectin-1 and TLRs in the recognition of β-1,3/β-1,6-glucans with different structural features may direct different cellular responses.     

A novel hepatoprotective saponin from Celosia cristata L.

A new saponin, cristatain (1), together with four other saponins, celosin A (2), celosin B (3), celosin C (4) and celosin D (5) were isolated from the seeds of Celosia cristata L. (Amaranthaceae). Their structures were established by chemical and spectroscopic analyses. For the first time, the saponins were found in C. cristata L. In addition, compound 1 exhibited significant hepatoprotective effect on carbon tetrachloride (CCl₄)- and N,N-dimethylformamide (DMF)–induced hepatotoxicity in mice, which were evidenced by significant decreases in the values of asparate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) of serum and histopathological examinations compared to controls.     

早春苦瓜嫁接栽培方法及效益分析

<正>苦瓜嫁接栽培能有效防治枯萎病、疫病,发病率分别比实生苗降低91.6%和92.8%。嫁接时砧木保留1片子叶或不保留子叶可降低侧枝发生率,保留2片子叶可提高嫁接成活率,生产上可以根据劳动力是否充足选择适宜嫁接方法。近年来,随着苦瓜在市场上的销量逐年增加,种植面积也在不断扩大,同时生产上也不可避免地     

Characterizinig Precipitation Chemistry in Changhua, Central Taiwan Using Weather Conditions And Multivariate Analysis

Few studies of atmospheric deposition come from the fast growing region of Southeast Asia. Precipitation in Changhua City in central Taiwan was collected to examine its chemical composition and relationship with meteorological patterns. Fifty percent of the precipitation measurements had pH<5.0. Deposition fluxes of most ions were comparable to that reported for heavily industrialized temperate regions. Storms associated with air masses which originated in China had higher ion concentrations than other storms, suggesting substantial contribution of long-range transport. Two factors, a sea salt factor and an anthropogenic factor, explained more than 70% of the variation in precipitation chemistry. A third factor had a high loading only on H⁺, suggesting that pH of precipitation in Changhua City was not dominated only by acidic or basic ions alone. Instead it is determined by all components. The influences of soil and dust, as indicated by high loading on Ca²⁺ and K⁺, cannot be recognized without sea salt correction.     

榆耳新品种‘旗肉 1 号’

 食用菌榆耳新品种‘旗肉1 号’,菌丝体洁白,粗壮浓密;子实体褐粉至粉红色,朵形如花, 单朵直径7.2 ~ 11.5 cm、质量110 ~ 200 g,品质佳,商品性好,从接种到采收需要90 ~ 105 d。每100 kg 干料产鲜榆耳55.2 kg。     

枇杷花开放过程挥发性物质变化研究

 采用顶空固相微萃取结合GC–MS 分析技术,对花蕾期、露白期、初放期和盛开期的枇杷 花的挥发性物质进行富集、分离和鉴定,分别鉴定出挥发性化合物84、90、69 和73 种,各占总挥发性 物质的93.84%、97.74%、92.56%和92.67%,都含有酮类、酸类、酯类、醛类、烃类、醇类和其他少量化 合物。从花蕾到盛开过程中,酯类化合物相对含量呈不断上升趋势,而醛类和酸类物质相对含呈快速下 降趋势,烃类和酮类先上升后下降。4–甲氧基苯甲酸甲酯、4–甲氧基苯甲酸乙酯、二–（2–苯乙基）– 草酸酯、苯甲醛、甲氧基苯甲醛、反式二己烯醛、苯乙醇、十三烷、二十一烷等成分是枇杷花香的主要 赋香物质,它们在枇杷花开放不同阶段的相对含量之和分别占总挥发性物质的55.03%、59%、72.68%和 70.71%。枇杷花从露白期到初放期具有较丰富的香气组成,应以此时为较佳的利用时期。     

Delta1-pyrroline-5-carboxylic acid formed by proline dehydrogenase from the Bacillus subtilis ssp. natto expressed in Escherichia coli as a precursor for 2-acetyl-1-pyrroline

Proline dehydrogenase (PRODH) catalyzes the biosynthesis of Delta1-pyrroline-5-carboxylic acid (P5C). The Bacillus subtilis subsp. natto gene for the proline dehydrogenase (BnPRODH) was cloned and expressed in Escherichia coli. Nucleotide sequence analysis of the clone revealed an open-reading frame that encodes 302 amino acid polypeptide with a calculated molecular mass of 34.5 kDa. The deduced amino acid sequence showed sequence similarity to bacterial PRODH and PutA of E. coli. The BnPRODH gene was cloned into pET21b and was expressed at a high level in E. coli BL21(DE3). The expressed protein was purified by using nickel ion affinity column chromatography to homogeneity before characterization. The purified recombinant BnPRODH was used to produce P5C. Model system composed of P5C and methylglyoxal was set up to study the formation of 2-acetyl-1-pyrroline. Our data showed that P5C, derived from the conversion of l-proline by the purified recombinant PRODH, might react directly with methylglyoxal to form 2-AP. P5C/methylglyoxal pathway represents the first report of a biological mechanism by which 2-AP may be synthesized in vitro by PRODH.