大苞藤黄化学成分研究及其互变异构体超高效液相色谱质谱联用分析

从大苞藤黄枝叶的混合粉碎物中分离到11个化合物,运用光谱手段分别鉴定为neobractatin(1),brasixanthone B (2),5-O-methylxanthone V1 (3),10-O-methylmacluraxanthone (4),isobractatin (5),xanthone V1(6),xerophenone A (7),xerophenone B (8),bractatin (9),macluraxanthone (10)和3-O-methylneobractatin (11).本文首次应用超高效液相色谱-质谱联用技术分离了异构体7和8并测定了其精确分子量.其中化合物6～8为首次从该植物中发现.     

南北样带温带区栎属树种种子化学组成与气候因子的关系

选取南北样带温带区8个核心分布区的7种优势栎属树种作为对象,通过检测种子的化学组成,包括淀粉、蛋白质、油脂、可溶性总糖、单宁和脯氨酸,分析其化学组成与气候因子之间的关系,结果发现:在气候因子中,温度是影响种子化学组成的主要因素,日照时数次之,而降水没有明显影响.在南北样带温带区,随纬度的增加,温度降低,年日照时数增加,生长积温减少,生长季缩短,淀粉含量积累下降,并趋向于水解为可溶性糖类;同时,从南到北,为适应低温的环境条件,栎属树种通过增加种子蛋白质、可溶性总糖和脯氨酸的含量,以提高种子的抗寒性.栎属树种种子的化学组成之间存在一定的相互关系,可溶性总糖、蛋白质和脯氨酸之间呈正相关关系,它们三者与淀粉均为负相关,种子化学组成之间的这种相互关系是植物对环境适应的生态策略.     

Surface roughness of denture base and reline materials after disinfection by immersion in chlorhexidine or microwave irradiation

doi: 10.1111/j.1741‐2358.2011.00484.x
Surface roughness of denture base and reline materials after disinfection by immersion in chlorhexidine or microwave irradiation Background: This study evaluated the effect of disinfection by immersion and microwave irradiation on the roughness of one denture base resin (Lucitone‐L) and five relining materials, three hard (Tokuyama Rebase II‐TR, New Truliner‐NT, Ufigel Hard‐UH) and two resilient (Trusoft‐T, Sofreliner‐S). Methods: Fifty specimens were made and divided into groups: CL2 specimens were brushed with 4% chlorhexidine (1 min), immersed in the same solution (10 min) and immersed in water (3 min); MW2 specimens were immersed in water and microwave irradiated (650W; 6 min); CL2 and MW2 specimens were disinfected twice; CL7 and MW7 specimens were submitted to seven cycles using chlorhexidine or microwave irradiation, respectively; W specimens were not disinfected and remained in water (37°C; 7 days). Results: Results were statistically analysed (p = 0.05) and revealed that, at baseline, the highest mean value was observed for T (p < 0.001). Material NT showed increase in roughness after the first (p = 0.003), second (p = 0.001), seventh (p = 0.000) cycles of microwave disinfection and after 7 days of immersion in water (p = 0.033). Conclusions: Resilient liner S presented significant increase in roughness after the second cycle of disinfection with chlorhexidine (p = 0.003). Material T exhibited significantly decreased roughness in group W (p = 0.010), while microwaving produced severe alterations on its surface.     

亚洲小车蝗痘病毒与化学杀虫剂混用的杀虫效果及对寄主主要解毒酶活性的影响

亚洲小车蝗痘病毒（Oedaleus asiaticus entomopoxvirus, OaEPV）作为一种增效剂,分别与马拉硫磷、毒死蜱、高效氯氰菊酯、氟氯氰菊酯 、溴氰菊酯化学杀虫剂混合饲喂亚洲小车蝗若虫,统计致死中浓度 LC₅₀ 和其混合使用后的增效比;测定虫体内与抗性有关的两种重要酶——羧酸酯酶（CarE）和谷胱甘肽 S-转移酶（GSTs）的比活力。结果表明：OaEPV 与化学杀虫剂混合饲喂亚洲小车蝗,OaEPV 与毒死蜱 、高效氯氰菊酯、氟氯氰菊酯、溴氰菊酯混用对亚洲小车蝗无明显的增效作用,OaEPV 与马拉硫磷混用,具有一定的增效作用,增效比为 1.42 倍。混剂感染亚洲小车蝗,除与溴氰菊酯混用外,虫体的中肠部位 CarE 的比活力都受到了明显的抑制作用,其中 OaEPV 与马拉硫磷混用下降了 4.21 倍,抑制作用最大。当 OaEPV 与氟氯氰菊酯、溴氰菊酯化学杀虫剂混用后,中肠部位 GSTs 受到了明显的抑制作用,而其脂肪体部位 CarE 和 GSTs 的变化无一定的规律性。结果提示痘病毒与农药混合处理时,病毒主要通过抑制中肠部位 CarE 比活力而增加了农药的杀虫效果。     

The effect of plant chemistry on the acceptability of caterpillar prey to the argentine antIridomyrmex humilils (Hymenoptera: Formicidae)

Experiments were performed to test the acceptability of two palatable, cryptic caterpillars, the tobacco hornworm,Manduca sexta, and the cabbage looper,Trichoplusia ni, reared on different diets, to the Argentine ant,Iridomyrmex humilis. Ants preferred larvae reared on artificial diet, groundcherry, or cowpea to tobacco-reared larvae. Ants also preferred larvae reared on artificial diet without nicotine to larvae reared on diet containing nicotine (5% dry wt). Experiments were also performed to test the response of ants to larval extracts and chemicals applied to the surface of palatable prey. Ants did not respond differently to larvae of the potato tuber moth,Phthorimaea operculella, treated with larval extracts or regurgitate from tobacco-reared larvae compared to artificialdiet-reared larvae, but ants were deterred byP. operculella larvae treated with nicotine compared to untreated larvae. The results of this study indicate that caterpillars can derive at least some degree of chemical protection from their food plant without sequestering and storing plant compounds and without the development of elaborate aposematic characteristics.     

Subcellular Distribution and Chemical Forms of Cadmium in the Medicine Food Homology Plant <i>Platycodon grandiflorum</i> (Jacq.) A.DC.

Although Platycodon grandiflorum (Jacq.) A.DC. is a renowned medicine food homology plant, reports of excessive cadmium (Cd) levels are common, which affects its safety for clinical use and food consumption. To enable its Cd levels to be regulated or reduced, it is necessary to first elucidate the mechanism of Cd uptake and accumulation in the plant, in addition to its detoxification mechanisms. This present study used inductively couple plasma-mass-spectrometry to analyze the subcellular distribution and chemical forms of Cd in different tissues of P. grandiflorum. The experimental results showed that Cd was mainly accumulated in the roots [predominantly in the cell wall (50.96%–61.42%)], and it was found primarily in hypomobile and hypotoxic forms. The proportion of Cd in the soluble fraction increased after Cd exposure, and the proportion of insoluble phosphate Cd and oxalate Cd increased in roots and leaves, with a higher increase in oxalate Cd. Therefore, it is likely that root retention mechanisms, cell wall deposition, vacuole sequestration, and the formation of low mobility and low toxicity forms are tolerance strategies for Cd detoxification used by P. grandiflorum. The results of this study provide a theoretical grounding for the study of Cd accumulation and detoxification mechanisms in P. grandiflorum, and they can be used as a reference for developing Cd limits and standards for other medicine food homology plants.     

Entomophagous insects – an introduction

This special issue contains papers presented at the 6th International Entomophagous Insects Conference. Entomophagous insects consume other insects. They are a fundamental component of ecosystems and are extensively used as biocontrol agents. The first article reviews the role of ladybirds in biological control and the second reviews the biological control of stink bugs. The following nine research articles cover the rearing, behavior, life history, and ecology of parasitoid and predator species.