辐解产物2-十二烷基环丁酮的测定方法

 【目的】建立1种含脂辐照食品中特异性辐解产物2－十二烷基环丁酮的萃取分离以及定量分析的新方法。【方法】采用硅胶层析柱萃取分离、气相色谱－质谱联用检测,对淋洗剂浓度、硅胶活化程度、收集时间及气相色谱-质谱条件等技术参数进行优化。【结果】该方法对2－十二烷基环丁酮标准品的最低检出限为0.005 mg?L-1,0.1～2.0 mg?L-1的添加回收率为75.9%～103.9%,相对标准偏差（RSD）均小于5.7%。【结论】与欧盟标准方法EN1785进行比较,硅胶柱分离法具有成本低、提取效率高、重现性好、检出限低、承载样品量大等优点。     

An Evaluation of two <Emphasis Type="Italic">H1</Emphasis>-Linked Markers and their Suitability for Selecting <Emphasis Type="Italic">Globodera rostochiensis</Emphasis> Resistant Potatoes in the New York Breeding Program

The golden cyst nematode (Globodera rostochiensis) is a serious pest that can dramatically reduce potato crop yield. Pathotype Ro1 of G. rostochiensis was first detected in the United States in 1941 and is still present on several farms in New York State. The H1 gene confers high levels of resistance to pathotype Ro1 but screening for it with a bioassay is time consuming and expensive. In this study two known molecular markers, 57R and TG689, were evaluated for their ability to identify resistant clones among 38 global cultivars and 350 New York breeding clones. The ability of either marker to predict resistance was high – 99.7% and 98.3% for 57R and TG689, respectively – but the ability to predict susceptibility was much lower, 47% and 41%, respectively. As resistance is the trait of interest, either of these markers is sufficient to make selection decisions in a practical breeding program. Cases exhibiting discordance between presence/absence of diagnostic markers and bioassay results were investigated further. Recombination, inflow of other resistance genes, and occasional failure of marker- and/or bio-assays are discussed as potential causes.     

Liquid Chromatography-Mass Spectrometry-Based Rapid Secondary-Metabolite Profiling of Marine Pseudoalteromonas sp. M2

The ocean is a rich resource of flora, fauna, and food. A wild-type bacterial strain showing confluent growth on marine agar with antibacterial activity was isolated from marine water, identified using 16S rDNA sequence analysis as Pseudoalteromonas sp., and designated as strain M2. This strain was found to produce various secondary metabolites including quinolone alkaloids. Using high-resolution mass spectrometry (MS) and nuclear magnetic resonance (NMR) analysis, we identified nine secondary metabolites of 4-hydroxy-2-alkylquinoline (pseudane-III, IV, V, VI, VII, VIII, IX, X, and XI). Additionally, this strain produced two novel, closely related compounds, 2-isopentylqunoline-4-one and 2-(2,3-dimetylbutyl)qunoline-4-(1H)-one, which have not been previously reported from marine bacteria. From the metabolites produced by Pseudoalteromonas sp. M2, 2-(2,3-dimethylbutyl)quinolin-4-one, pseudane-VI, and pseudane-VII inhibited melanin synthesis in Melan-A cells by 23.0%, 28.2%, and 42.7%, respectively, wherein pseudane-VII showed the highest inhibition at 8 µg/mL. The results of this study suggest that liquid chromatography (LC)-MS/MS-based metabolite screening effectively improves the efficiency of novel metabolite discovery. Additionally, these compounds are promising candidates for further bioactivity development.     

Anticancer Activity of Mannose-Specific Lectin,BPL2, from Marine Green Alga Bryopsis plumosa

Lectin is a carbohydrate-binding protein that recognizes specific cells by binding to cell-surface polysaccharides. Tumor cells generally show various glycosylation patterns, making them distinguishable from non-cancerous cells. Consequently, lectin has been suggested as a good anticancer agent. Herein, the anticancer activity of Bryopsis plumosa lectins (BPL1, BPL2, and BPL3) was screened and tested against lung cancer cell lines (A549, H460, and H1299). BPL2 showed high anticancer activity compared to BPL1 and BPL3. Cell viability was dependent on BPL2 concentration and incubation time. The IC₅₀ value for lung cancer cells was 50 μg/mL after 24 h of incubation in BPL2 containing medium; however, BPL2 (50 μg/mL) showed weak toxicity in non-cancerous cells (MRC5). BPL2 affected cancer cell growth while non-cancerous cells were less affected. Further, BPL2 (20 μg/mL) inhibited cancer cell invasion and migration (rates were ˂20%). BPL2 induced the downregulation of epithelial-to-mesenchymal transition-related genes (Zeb1, vimentin, and Twist). Co-treatment with BPL2 and gefitinib (10 μg/mL and 10 μM, respectively) showed a synergistic effect compared with monotherapy. BPL2 or gefitinib monotherapy resulted in approximately 90% and 70% cell viability, respectively, with concomitant treatment showing 40% cell viability. Overall, BPL2 can be considered a good candidate for development into an anticancer agent.     

Ac novachip: a new potato cultivar with excellent chip quality after long storage and reconditioning

AC Novachip is a smooth, white-skinned potato cultivar with oval to oblong tubers and a maturity similar to Kennebec. It has excellent chip quality, especially after long storage and reconditioning. The boil and bake quality is similar to Kennebec; the specific gravity is higher than Kennebec but lower than Atlantic. AC Novachip has moderate resistance to common scab and PVY.     

Glycol Chitosan-Based Fluorescent Theranostic Nanoagents for Cancer Therapy

Theranostics is an integrated nanosystem that combines therapeutics with diagnostics in attempt to develop new personalized treatments with enhanced therapeutic efficacy and safety. As a promising therapeutic paradigm with cutting-edge technologies, theranostic agents are able to simultaneously deliver therapeutic drugs and diagnostic imaging agents and also monitor the response to therapy. Polymeric nanosystems have been intensively explored for biomedical applications to diagnose and treat various cancers. In recent years, glycol chitosan-based nanoagents have been developed as dual-purpose materials for simultaneous diagnosis and therapy. They have shown great potential in cancer therapies, such as chemotherapeutics and nucleic acid and photodynamic therapies. In this review, we summarize the recent progress and potential applications of glycol chitosan-based fluorescent theranostic nanoagents for cancer treatments and discuss their possible underlying mechanisms.     

不同杀菌剂对马铃薯早疫病的田间防效试验

2009～2010年通过田间小区方法进行了6种杀菌剂防治马铃薯早疫病(Alternaria solani)的试验。结果表明:75%拿敌稳水分散性粒剂6 000倍、50%肟菌酯水分散性粒剂4 000倍、43%好力克悬浮剂3 000倍、25%阿米西达悬浮剂1 200倍效果均比较好,防效在82.0%～84.3%之间,70%安泰生可湿性粉剂400倍次之,防效75.9%～76.0%;80%代森锰锌500倍再次之,防效66.2%~66.8%。以上6种杀菌剂均可作为防治马铃薯早疫病的有效药剂应用。     

Prevention of atrophic rhinitis in piglets by means of intranasal administration of a live non-AR-pathogenic Bordetella bronchiseptica vaccine

The effect of intranasal vaccination of piglets with live non-AR-pathogenic Bordetella bronchiseptica (BB-) against Atrophic Rhinitis (AR) was investigated in a preliminary investigation and in a field trial. In the preliminary investigation 2-day-old SPF piglets (n = 13) were vaccinated. Three weeks after vaccination, challenges were carried out by means of a spray with an AR-pathogenic B (BB+) or an AR-pathogenic Pasteurella multocida (PM+) broth-culture. Four weeks later the piglets were necropsied and examined for atrophy of the ventral conchae (AVC). In contrast with the non-vaccinated SPF piglets, the vaccinated piglets showed a strong and significant reduction of AVC, after both BB+ and PM+ challenge. In the field trial three groups were formed by drawing lots: ten litters (82 piglets) were vaccinated; ten litters (92 piglets) formed the control group and 11 litters (104 piglets) were treated with a placebo. The litters were spread over two units. In unit 1 AR and PM+ were demonstrated incidentally, in unit 2, however, persistently. BB+ was isolated equally frequently in both units. Clinical and bacteriological examinations were done in piglets of 3, 6 and 8 weeks of age. Necropsy examinations was carried out in 41 piglets of 8 weeks of age, chosen randomly by drawing lots. In spite of a second vaccination at the age of 3 weeks, BB- was not well established; this was possibly caused by maternal BB antibodies. In the control and placebo groups PM+ was isolated earlier and more frequently than BB+. It appeared that AVC was correlated more strongly with PM+ than with BB+ infection in the field trial. The percentage of piglets with Brachygnathia superior (BS) at the age of 8 weeks indicated the AR situation in the herd. Although a significant reduction of AVC was determined in unit 2, it was not sufficient to indicate that this method of intranasal vaccination is useful in the prevention of AR in practice.     

Analysis of tetraploid-diploid hybrids in cultivated potatoes

Summary Progeny families of 4x−2x hybrids between Group Tuberosum and Group Phureja-haploid Group Tuberosum hybrids were evaluated under simulated commercial agricultural practices in 1974 and 1975. The range of the observed values for the 4x−2x hybrids exceeded the range of the 4x parents for nearly all measured traits. The mean for total yield of the 4x−2x hybrids was equal to (1974 experiment or significantly higher (1975 experiment) than the mean of the 4x parents. In the 1975 experiment 17.8% of the 4x−2x hybrids produced a higher total yield than the highest yielding 4x parents. The 4x−2x hybrids exhibited a significantly lower mean than the 4x parents for marketable yield and tuber weight but transgressive segregants were found for these traits in both experiments. The heterosis and variability of the hybrids indicates that this breeding method is a potentially powerful tool in potato improvement.

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Zusammenfassung Zwei Gruppen von Phureja-haploiden Tuberosumhybriden, von denen bekannt ist, dass sie diplandroide Gameten durch den Parallelspindelmechanismus bilden, wurden als m?nnliche Elternteile für verschiedene weibliche Eltern der Gruppe Tuberosum benutzt (Tabelle 1). Nachkommenschaften aus 4x−2x-Kreuzungen wurden 1974 und 1975 unter ?hnlichen landwirtschaftlichen Bedingungen geprüft. Der Schwankungsbereich der gemessenen Werte für die 4x−2x Hybriden überstieg den der 4x Eltern in nahezu allen gemessenen Merkmalen in beiden Versuchen. Die 4x−2x Hybriden hatten einen signifikant niedrigeren Durchschnittswert für marktf?higen Ertrag und Knollengewicht, aber in beiden Versuchen wurden transgressive Abweichungen für diese Merkmale gefunden (Tabelle 2). 1975 ergaben 17.8% der 4x−2x Hybriden einen h?heren Gesamtertrag als die besten 4x Eltern (Abb. 1). 1975 wurden hoch signifikante Unterschiede bei fast alle gemessenen Merkmalen zwischen Familien gefunden, die von verschiedenen 4x Eltern abstammen (Tabelle 3). Das deutet auf betr?chtliche Unterschiede dieser Merkmale in der allgemeinen Kombinationsf?higkeit in den 4x Eltern hin. Unterschiede in der allgemeinen Kombinationsf?higkeit bestehen auch zwischen den zwei 2x Eltern (Tabellen 3 und 4). Zwischen den 4x und 2x Eltern konnten keine signifikanten Wechselwirkungen beobachtet werden (Tabelle 3). Das Gesamtergebnis der 4x−2x Hybriden war sehr ermutigend. Ein breiterer Gebrauch dieser Züchtungsmethode h?ngt von der Entwicklung kultivierter diploider Eltern ab, in denen das Merkmal diplandroider Bildung mit relativ früher Reife und anderen Eigenschaften wie Knollenform und Augentiefe kombiniert ist. Wenn solche Klone verfügbar werden, werden die Kartoffelzüchter ein noch m?chtigeres Werkzeug haben, um Zuchtst?mme und Sorten mit hohen Ertr?gen zu züchten.

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Résumé Deux hybrides issus du groupe Phureja haplo?de-groupe Tuberosum, connus pour leurs gamètes diplandres obtenus par le mécanisme du fuseau parallèle, ont été utilisés comme géniteurs males, avec plusieurs géniteurs femelles du groupe Tuberosum (tableau 1). La descendance d'hybrides 4x−2x a été étudiée dans des conditions similaires à celles de la pratique en 1974 et 1975. Le classement des valeurs observées pour les hybrides 4x−2x est supérieur à celui des géniteurs 4x pour presque tous les critères évalués dans les deux essais. Les hybrides 4x−2x ont en moyenne un rendement commercialisable et un poids par tubercule significativement inférieurs aux géniteurs 4x, mais une transgression est observée pour ces caractères dans les deux essais (tableau 2). Dans l'essai de 1975, 17,8% des hybrides 4x−2x ont donné un rendement total supérieur aux meilleurs géniteurs 4x (fig. 1). Des différences hautement significatives ont été mises en évidence en 1974 pour presque tous les critères mesurés, entre des familles issues de différents géniteurs 4x (tableau 3). Ceci suggère qu'il existe en général de grandes différences dans l'aptitude à la recombinaison de ces critères parmi les géniteurs l'aptitude à la recombinaison de ces critères parmi les géniteurs 4x. Des différences se retrouvent également entre les parents 2x (tableaux 3 et 4). Aucune intéraction significative n'a pu être détectée entre les géniteurs 4x et 2x (tableau 3). Les résultats obtenus avec les hybrides 4x−2x sont très encourageants. Une plus large utilisation de cette méthode suppose l'obtention de géniteurs diplo?des dans lesquels la formation du caractère diplandre est associée à une maturité relativement plus précoce et à d'autres caractéristiques agronomiques telles que le type de tubercule et la profondeur des yeux. Quand de tels clones seront disponibles, les obteneurs auront un outil encore plus puissant pour produire du matériel génétique de haut rendement et des variétés.

     

Spatio-temporal variations in meteorology drought over the Mekong River Delta of Vietnam in the recent decades

Paddy and Water Environment - In recent years, Mekong Delta of Vietnam is severely affected by salinity intrusion and water scarcity due to climate variability. In this study, a comprehensive...