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Shamsunnahar Khushi Angela A. Salim Ahmed H. Elbanna Laizuman Nahar Robert J. Capon 《Marine drugs》2021,19(2)
Thorectandra choanoides (CMB-01889) was prioritized as a source of promising new chemistry from a library of 960 southern Australian marine sponge extracts, using a global natural products social (GNPS) molecular networking approach. The sponge was collected at a depth of 45 m. Chemical fractionation followed by detailed spectroscopic analysis led to the discovery of a new tryptophan-derived alkaloid, thorectandrin A (1), with the GNPS cluster revealing a halo of related alkaloids 1a–1n. In considering biosynthetic origins, we propose that Thorectandra choanoides (CMB-01889) produces four well-known alkaloids, 6-bromo-1′,8-dihydroaplysinopsin (2), 6-bromoaplysinopsin (3), aplysinopsin (4), and 1′,8-dihydroaplysinopsin (10), all of which are susceptible to processing by a putative indoleamine 2,3-dioxygenase-like (IDO) enzyme to 1a–1n. Where the 1′,8-dihydroalkaloids 2 and 10 are fully transformed to stable ring-opened thorectandrins 1 and 1a–1b, and 1h–1j, respectively, the conjugated precursors 3 and 4 are transformed to highly reactive Michael acceptors that during extraction and handling undergo complete transformation to artifacts 1c–1g, and 1k–1n, respectively. Knowledge of the susceptibility of aplysinopsins as substrates for IDOs, and the relative reactivity of Michael acceptor transformation products, informs our understanding of the pharmaceutical potential of this vintage marine pharmacophore. For example, the cancer tissue specificity of IDOs could be exploited for an immunotherapeutic response, with aplysinopsins transforming in situ to Michael acceptor thorectandrins, which covalently bind and inhibit the enzyme. 相似文献
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红小豆新旧品种产量构成因素差异分析 总被引:2,自引:0,他引:2
在日本北海道十胜地区是红小豆生产基地,栽培历史已有100多年.本研究就是对红小豆新旧品种产量和产量构成因素的改良进行阐述和分析.试验2000年和2001年在带广蓄产大学试验场进行.选择10个有代表性的品种,最老的品种是Maruha(1905),最新的品种是Hokuto-dainagon(1996). 试验采取裂区法,3次重复.施肥和密度分别设3个水平.在花期和收获期调查生育性状以及产量和产量构成因素.实验结果:(1)试验年的气候条件差异非常大,2000年为丰年,2001年为欠年.(2)晚熟品种Maruha在丰年产量非常高,但在欠年产量非常低,表现不稳定.所以在和新品种进行产量对比时,用旧品种Chgarawase(3 120 kg/hm2),新品种Erimoshozu(4 390 kg/hm2), Kitano-otome(4 050 kg/hm2) and Hokuto-dainagon(4 750 kg/hm2) 分别增加41%,30%和52%.(3)单株荚数与籽实产量有密切相关,但荚粒数和百粒重与籽实产量相关性低.与旧品种Chagarawase(单株荚数23)比较,新品种Erimoshouzu(29), Kitano-otome(28) and Hokuto-dainagon(26), 分别增加26%,22%和13%.(4)方差分析结果,品种之间,熟期之间,密度之间, 产量和产量构成因素差异达到显著或极显著水平,但施肥水平之间,产量和产量构成因素差异没有达到显著水平. 相似文献
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两种方法对玉米几个株型性状遗传效应的比较分析 总被引:3,自引:0,他引:3
以7个自选系、7个外引系、外杂选系和按NCⅡ组配的49个杂种F1组合为研究材料。对差异显著的7个株型性状应用混合线性模型、配合力两种分析方法对遗传方差和遗传力进行了比较分析。结果表明:混合模型分析雄穗长揭示了显著的显性效应和不显著的加加上位性与 性效应,雄穗分枝数与其干重揭示了极显著的显性效应与加性效应,其余性状揭示了极显著的显性效应与加加上位性效应;配合力分析是在加-显遗传模型基础上进行的,只能揭示加性和显性效应,两种分析方法所得各遗传方差分量都存在显著差异,其差异因性状而异。分析表明,这些差异可能是由于不同方法对剩余方差分量和加性遗传方差分量估算不同而引起的。广义遗传率差异大小是基因型与环境的互作而引起的;狭义遗传率差异一部分是基因与环境的互作,另一部分却是两种方法所估算的加性(加加上位性)遗传方差不同而引起的。 相似文献
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《中国马铃薯》2016,(3):169-174
由Pectobacterium atroseptica引起的马铃薯黑胫病是影响马铃薯生产的重要种薯传播细菌病害,从种薯发芽到生长后期均可发病,严重影响马铃薯的产量和品质。为构建马铃薯黑胫病菌的分离、鉴定技术体系,从广东省惠州市惠东县大水坑马铃薯基地采集了疑似感染马铃薯黑胫病植株,对其进行病原菌分离和纯化,得到7株病菌,利用引物Eca 1 g/Eca 2 g对其进行PCR扩增、将PCR产物测序并将所测定序列递交Gen Bank数据库,使用Blast软件进行比对确定目标菌株。结果表明,其中一株菌株能扩增出长度大约688 bp的特异性条带,其DNA序列符合Eca 3762序列,鉴定为马铃薯黑胫病菌。此方法可以成功地从发病植株中分离出黑胫病菌,成本较低廉,为广东省建立马铃薯种薯质量检测和控制体系提供技术支撑。 相似文献
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Grasslands in ‘Old World’ and ‘New World’ Mediterranean‐climate zones: past trends,current status and future research priorities
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C. Porqueddu S. Ates M. Louhaichi A. P. Kyriazopoulos G. Moreno A. del Pozo C. Ovalle M. A. Ewing P. G. H. Nichols 《Grass and Forage Science》2016,71(1):1-35
Despite their ecological, economic and social importance, grasslands in areas with Mediterranean climates continue to receive limited scientific, political and media attention. The main objectives of this review are to compare and contrast dryland grasslands in the ‘Old World’ regions of the Mediterranean basin (southern Europe, western Asia and North Africa) with those of ‘New World’ regions with Mediterranean climates (Australia and Chile) and to identify common research priorities. The common characteristics and differences in climate, soils, native vegetation, importance of the livestock sector and the socio‐economic background for the different Mediterranean environments are examined. Past trends and the current status of temporary and permanent Mediterranean grasslands are also described. Some common issues between these regions are as follows: (i) adaptation to climate change; (ii) increasing persistence and drought survival of both annual and perennial species; (iii) the important role of forage legumes; (iv) maintaining grassland plant diversity; and (v) improved ecosystem services, such as carbon sequestration, control of soil erosion and wildfires, and preservation of both wild and domestic biodiversity. The favourable climate in these regions, which allows year‐round grazing and the growth of legumes, should be exploited to improve the sustainability of grassland‐based, extensive farming systems and the quality of their animal products, while at the same time improving ecosystem services. The decreasing support for grassland research and development programmes requires increased international scientific and technical cooperation among the few institutions operating in the different Mediterranean‐climate areas of the World to provide innovative and sustainable solutions to farmers. 相似文献
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BACKGROUND: The aim of this study was to compare invasive and non-invasive strains of Shigella flexneri isolated from Tehran by a 120 kDa protein band by SDS-PAGE, electron microscopy of cell culture and Congo red dye methods. METHODS: S. flexneri strains were isolated by standard bacterial methods from fecal specimens of children attending to the 3 children's hospitals. Phenotype analysis for screening virulent of strains of S. flexneri was done on a plate of tryptic soy agar contained 0.003% Congo red dye. Whole membrane protein preparations were used to examine the protein profiles of the inner and outer membrane of these Gram-negative bacteria. The protein mixture was electrophoresed through a polyacrylamide gel. The gel was stained with Coomassie brilliant blue R250 and destained with ethanol and acetic acid. HeLa cell culture was done by two-step preparations: one for light microscopy and the other for electron microscopy. RESULTS: Some of S. flexneri (46%) were Congo red positive colonies. S. flexneri with negative Congo red phenotype could not enter the HeLa cell culture. A 120 kDa protein band was found in 46% of these bacteria which could enter into HeLa cell culture. Pseudopod structures which facilitate bacterial cell-to-cell spread were readily identified by electron microscopy. DISCUSSION: Since the existence of 120-kDa protein band was corresponded to enter of S. flexneri into the HeLa cell culture and correlated with Congo red dye positive, for identification of invasive and non-invasive S. flexneri strains, the use of a 120-kDa protein band by SDS-PAGE or a simple, rapid and very cheap Congo red dye method is recommended. Because, there are some deaths due to Shigella sp. in our country, notification on the isolation of these bacteria in both children hospitals laboratories and private clinical laboratories is important. 相似文献
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咖啡、可可和茶的全球发展比较研究 总被引:1,自引:1,他引:0
搜集整理自1961年以来咖啡、可可及茶产业的相关数据,分别从种植面积、年总产量、单位面积产量、出口量、出口单价等方面,对其进行系统的统计分析,据此探讨了3种软饮料作物的发展历程及其特点,并对各自发展趋势和相互关系进行了讨论。 相似文献
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茶叶对老龄大鼠血糖、血脂及抗氧化功能的影响 总被引:7,自引:2,他引:5
108只12月龄退役SD大鼠分成13组经二个半月的红、绿茶添加饲料和茶汤的饲喂试验,结果表明,红茶和绿茶无论是干茶添加在饲料中还是茶汤,各处理均能显著降低老龄大鼠的血糖含量(P<0.05)、血脂含量(P<0.01);显著提高其SOD酶活力(P<0.01);显著降低其MDA含量(红茶达P<0.01水平,绿茶达P<0.05水平),其中绿茶降血脂能力比红茶强,而红茶抗氧化效果比绿茶显著。后者说明,茶叶的生物抗氧化机制除茶多酚类物质起作用外,还存在着其他更为重要的机制。 相似文献
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Dr. Barbara J. Struthers Janice R. Macdonald 《Plant foods for human nutrition (Dordrecht, Netherlands)》1985,35(3):331-337
Feeding of raw and heated soy flour (RSF & HSF) for 4 or 8 weeks to weanling swine was compared with feeding of casein diets. There was essentially no growth in pigs fed RSF, whereas body weight increased 4.5 fold over 8 weeks with either casein or HSF. No change in pancrease weight as percent body weight was found in any group in either experiment. Both total pancreatic RNA and DNA were decreased in RSF groups, although RNA and DNA/mg pancreas were increased by the RSF diets. Total pancreatic protein, as well as protein/mg, were decreased in RSF-fed pigs compared to casein and HSF. Pancreatic trypsin, chymotrypsin, lipase, and amylase, and fecal trypsin were decreased in RSF-fed pigs to varying degrees compared to either HSF or casein. HSF and casein performance was equivalent in all parameters measured. Results of these experiments are compared with results of feeding similar diets to rats and monkeys. 相似文献
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A study on the gastrointestinal parasites among free-living and captive primates at the Afi Mountain, Primate Conservation Area in Calabar, Nigeria was undertaken for the first time to ascertain their zoonotic implications. Faecal samples were subjected to direct smear, floatation, quantitative estimation of helminth eggs (epg) and oocysts (opg), larval isolation and identification by modified Baerman's technique and oocyst sporulation for specie identification. Out of the 108 primates examined, 75(69.44%) were found to be shedding the ova and oocysts of several gastrointestinal parasites of which, the mona monkeys (Cercopethicus mona) 16(80%) followed by the white collared mangabey (Cercocebus torquatus) 7 (77.78) had the highest (p < 0.05) prevalence of infection. Meanwhile, the chimpanzees (Pan troglodytes) had the highest ova or oocyst counts and variety of gastrointestinal parasites such as Ascaris lumbricoides, Trichuris trichiura, Balantidium coli, Enterobius vermicularis, Entamoeba histolytica, Strongyloides stercoralis, Blastocystis hominis, Hymenolepis nana, Schistosoma mansoni, Ancylostosoma duodenale and Cryptosporidium species. Similarly, the drill (Mandrillus leucophaeus), Sclater's white-nosed monkey (Cercopethicus erythrotis sclateri), white-collared mangabey (Cercocebus torquatus) and others, had Ascaris lumbricoides or Ancylostoma duodenale. All captive primates were more infected than those under free-roam. The young (< 12 months) and females had higher infection rates (p < 0.05) than their counterparts. In conclusion, the primates harboured several parasites of zoonotic importance. 相似文献
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"中苎一号"快速丰产稳产栽培要点 总被引:2,自引:2,他引:0
“中苎一号”系中国农业科学院麻类研究所近年来选育的又一个优质、高产、多抗苎麻新品种,我市于2004年3月引入。该品种经我市几年的栽培、观察,具有如下显著特点:一是投产早,该品种发蔸快,当年早春栽苗,当年每公顷可收获原麻1125kg左右;二是产量高,该品种脚麻少,有效株率高,茎杆粗壮,每年每公顷成林麻园可收获原麻3750kg左右;三是纤维品质好,原麻纤维支数在2000支左右;四是抗逆性强,该品种茎杆粗硬、根系发达,因而麻株抗倒、耐旱,平原湖区、丘陵区均适宜建园;五是易收获,该品种皮骨易分离,好剥好刮,收获容易。 相似文献
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《Plant Production Science》2013,16(3):365-380
AbstractA high nitrogen-uptake capacity and effective use of absorbed nitrogen for dry matter and grain production are required to improve the production cost and environmental pollution. We characterized grain yield, dry matter production and nitrogen accumulation in six rice cultivars: Sekitori (released in 1848) and Aikoku (1882), referred to as SA cultivars hereafter; Koshihikari (1956); Nipponbare (1963) and Asanohikari (1987), referred to as NA cultivars hereafter; and Takanari (in 1990) as a high-yielding modern cultivar. The plants were grown with and without chemical fertilizer in a submerged paddy field. When plants were supplied with manure and chemical fertilizer, Takanari consistently produced the heaviest grain and dry matter, followed by the NA cultivars, and the SA cultivars the lightest. Dry matter production before heading was greater in Takanari and the NA cultivars due to the longer duration of vegetative growth. Dry matter production after heading was greatest in Takanari, with a larger crop growth rate (CGR), and smallest in the SA cultivars with a shorter ripening time. Greater dry matter production during ripening was accompanied by the greater accumulation of nitrogen by Takanari and NA cultivars. These plants developed a larger amount of roots. The smaller light extinction coefficient of the canopy was also attributed to the higher CGR in Takanari. When plants were grown without chemical fertilizer, Takanari also produced heavier grain and dry matter, followed by the NA cultivars. The heavier grain in these cultivars resulted from the greater dry matter production before heading, which was due to the longer period of vegetative growth. The greater dry matter production and nitrogen accumulation by Takanari and NA cultivars were evident when plants were grown with chemical fertilizer. Koshihikari was characterized by a higher CGR and greater nitrogen accumulation during ripening in the absence of chemical fertilizer which should be noted in efforts to decrease rates of nitrogen application. 相似文献