Quorum Quenching Agents: Resources for Antivirulence Therapy     

Kaihao Tang  Xiao-Hua Zhang 《Marine drugs》2014,12(6):3245-3282

The continuing emergence of antibiotic-resistant pathogens is a concern to human health and highlights the urgent need for the development of alternative therapeutic strategies. Quorum sensing (QS) regulates virulence in many bacterial pathogens, and thus, is a promising target for antivirulence therapy which may inhibit virulence instead of cell growth and division. This means that there is little selective pressure for the evolution of resistance. Many natural quorum quenching (QQ) agents have been identified. Moreover, it has been shown that many microorganisms are capable of producing small molecular QS inhibitors and/or macromolecular QQ enzymes, which could be regarded as a strategy for bacteria to gain benefits in competitive environments. More than 30 species of marine QQ bacteria have been identified thus far, but only a few of them have been intensively studied. Recent studies indicate that an enormous number of QQ microorganisms are undiscovered in the highly diverse marine environments, and these marine microorganism-derived QQ agents may be valuable resources for antivirulence therapy.  相似文献   

福建乌龙茶产业可持续发展的对策建议     

韩海东  ;褚丽娟  ;刘明香  ;黄秀声  ;黄毅斌 《山地农业生物学报》2014,(3):78-82

通过对福建乌龙茶产业及相关产业链发展现状的调研,分析该产业存在问题,查阅相关资料,提出福建乌龙茶产业的可持续发展不仅要注重茶园的生态建设和休闲旅游开发,提高茶叶的品质及安全,将茶产业与旅游业有机结合,实现茶产业从第一产业向第三产业的跨越升级,更要借鉴国际茶产业应用精深加工开发茶叶副产品的先进经验,重视精深加工技术的研发,提取茶中含有的各种既有“有效成分”又有“活性成分”化学物质,发挥茶的医疗效能,弘扬中医和茶文化结合的荼疗生态文化,为“十二五”实现福建乌龙茶产业的可持续发展提出对策建议。  相似文献   

不同土层中氮磷钾养分对红松针叶磷素的影响     

王超逸  郭亚芬  崔晓阳 《森林工程》2014,(3):33-38

本文以红松1~2年生叶片和其林下生长的土壤为对象,研究红松叶片中磷含量、磷贮量及其林下土壤中0~20、20~40和40~60 cm土层的氮磷钾矿质养分含量。揭示叶片质量、磷素水平与各层土壤速效氮、速效钾和速效磷的相互关系。结果表明：叶片质量与土壤中速效养分含量无关,土壤中速效氮含量与针叶磷含量无关,0~20 cm土层的速效钾含量与2年生针叶磷含量显著相关。不同年生针叶的磷含量与各土层的速效磷含量都有显著的回归关系。针叶中磷贮量与土壤中速效养分无明显相关性。  相似文献   

松针提取物对广西麻鸡血液生化指标、抗氧化能力及免疫功能的影响     

陆海英  ;葛洪伟  ;唐燕飞  ;韦宗海  ;吴芳辉 《饲料博览》2014,(10):47-50

为研究松针提取物对广西麻鸡血液生化指标、抗氧化能力和免疫功能的影响,试验选取1日龄广西麻鸡1 600只作为试验动物进行120 d的饲养试验。试验鸡群随机分为2组,每组2个重复。在饲养过程中,对照组饲喂基础饲粮;试验组全程在基础饲粮中添加松针提取物。结果表明,试验组显著提高血清中谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(SOD)的活性、提高总抗氧化能力(T-AOC)和降低血清中丙二醛(MDA)的含量(P0.05);显著提高IgA、IgG、IgM、补体C3和补体C4的含量(P0.05);显著提高血清中钙、磷的含量,降低血清中胆固醇的含量(P0.05)。因此,松针提取物能够显著改善广西麻鸡的血液生化指标,提高广西麻鸡的抗氧化能力和免疫功能。  相似文献   

空心板板缝开裂的原因及预防措施     

周辉  张文斌  王芳 《林业科技情报》2000,(1)

本文较为详细地论述了预制楼板裂缝产生的原因;预防预制楼板开裂的有效措施以及裂缝出现后的有效补救方法。  相似文献   

海滨滩涂区抛石挤淤路基处理方案   总被引：1，自引：0，他引：1  

付家莹  薛东焱 《林业科技情报》2000,(4)

本文从实例出发,仔细地分析了海滨填海路基的特点,针对具体情况提出相应的处理加固方法,对于其他地质条件下的软土路基处理有一定的参考性。  相似文献   

Nature and origin of stone stripes on the Columbia Plateau     

George W. Cox  Jodee Hunt 《Landscape Ecology》1990,5(1):53-64

Beds of size-sorted stones forming stripes perpendicular to the contour are conspicuous on hillsides of the Columbia Plateau. Stripes occur on terrain ranging from 0° to about 30° in steepness, often beginning among Mima-type mounds on mesa tops and extending downward onto steep, unmounded slopes. Four mechanisms of their origin have been hypothesized: 1) water erosion, 2) solifluction and soil creep, 3) weathering of rock outcrops, and 4) tunneling by pocket gophers. We measured characteristics of five stripes on slopes of differing exposure and steepness. These stripes were 58–124 m long, and widths showed a maximum range of 0.55–3.70 m. Data on physical and biotic characteristics of the stripes suggest that pocket gopher tunneling is a basic mechanism of stripe formation on gentle slopes, and that this mechanism is augmented by outcrop weathering and colluvial dynamics on steeper slopes, with erosion playing a secondary role.  相似文献   

Canine Vogt-Koyanagi-Harada-like Syndrome in Two Siberian Husky Dogs     

ANTONELLA VERCELLI  STEFANO TARAGLIO 《Veterinary dermatology》1990,1(3):151-158

Abstract— A syndrome of uveitis, associated with depigmentation and erosion of areas of skin and mucous membrane on the head and, in one dog, on the scrotum, was observed by the authors in two male Siberian Huskies. These clinical signs are similar to the Vogt-Koyanagi-Harada syndrome in man. Histological examination of the affected skin revealed a lichenoid dermatitis of the upper dermis. Intensive topical therapy with mydriatic and cycloplegic drugs and corticosteroids coupled with systemic prednisolone and azathioprine were used to control the disease. Both subjects were monitored for 10 months and retained useful vision. The skin and oral lesions resolved. Résumé— Un syndrome d'uvéite idiopathique, non traumatique, associée à une dépigmentation et une érosion de zones cutanée et muqueuse sur la tête et, chez un chien, sur le scrotum, a été observé par les auteurs sur deux mâles Siberian Huskies. Ces signes cliniques évoquent le syndrome de Vogt—Koyanagi—Harada de l'homme. Un examen histologique de la peau atteinte a montré l'existence d'une dermatite lichénoide du derme superficiel. Un traitement topique intensif par des médicaments mydriatiques et cyclopégiques, ausociéà l'administration systémique de prednisolone et d'azathioprine a été utilisé pour controler la maladie. Les 2 sujets ont été observés pendant 10 mois et ont retrouvé une vision utile. Les lésions cutanées et orales ont guéri. Zusammenfassung— Bei zwei Husky-Rüden wurden von dem Autoren ein Krankheitssyndrom aus idiopathischer, nicht-traumatisch bedingter Uveitis, Depigmentierung einzelner Haut- und Schleimhautbezirke am Kopf und—bei einem Hund—am Skrotum festgestellt. Diese Symptome ähneln dem Vogt-Koyanagi-Harada-Syndrom beim Menschen. Bei der histologischen Untersuchung von Biopsien der erkrankten Hautbezirke wurde eine lichénoide Dermatitis der oberen Dermisschichten diagnostiziert. Durch eine intensive örtliche Behandlung mit Mydriatica, Cycloplegica und Corticosteroiden in Kombination mit systemischer Prednisolon- und Azathioptringabe konnte die Erkrankung unter Kontrolle gehalten werden. Beide Patienten wurden 10 Monate überwacht und sahen zufriedenstellend aus. Die Veränderungen an Haut und Mundhöhle bildeten sich zurück. Resumen Los autores describen un síndrome de uveitis no traúmatica idiopática asociada a una despigmentación y erosión de áreas de la piel y de las membranas cutáneas de la cabeza, en un perro y del escroto en otro perro. Ambos animales pertenecían a la raza Siberian Husky. Estos signos clínicos se asemejan en los descritos en la síndrome de Vogt-Koyanagi-Harada de las personas. El examen histológico mostró la presencia de un infiltrado inflamatorio liquenoide en la dermis superficial. Para el tratamiento a la enfermedad se aplicaron corticosteroides y fármacos midriáticos y ciclopéjicos de forma tópica y prednisona de forma sistémica. Ambos animales fueron controlados durante diez meses y mantuvieron la visión. Las lesiones orales y cutáneas se resolvieron por completo.  相似文献   

Community‐Based Rehabilitation of Mountain Terraces in Cyprus     

《Land Degradation \u0026amp; Development》2017,28(1):95-105

Participatory methods and community‐based approaches have an important role to play in combating land degradation. This paper follows a well‐defined participatory framework to identify key stakeholders and to select Sustainable Land Management approaches for reducing soil erosion and land degradation in the Troodos Mountains of Cyprus. Among the options suggested and evaluated by stakeholders, terrace rehabilitation had the best overall performance, followed by crop diversification and afforestation. Stakeholders agreed that the rehabilitation of dry‐stone terraces was the preferred option, as it is a practice with high environmental benefits and fits well in the local socio‐cultural context, despite the higher cost compared to other options. In the first year of implementing the approach, three mountain communities co‐organised hands‐on terrace maintenance events, engaging more than 160 people in rehabilitation activities. The community‐based approach has sparked the interest of people within and beyond the research site, and another series of events is scheduled for the coming season. This outcome indicates that social innovations can benefit from the integration of local and scientific knowledge, while participatory process can enhance the self‐confidence and organisational structures of local communities. Sustaining and enhancing the impact of the approach in the long‐run require developing local terrace maintenance institutions, actively engaging the youth in terrace management and improving the profitability of mountain farming through the differentiation of local products. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

群体遗传结构的理解   总被引：4，自引：0，他引：4  

胡新生 《林业科学》2002,38(2):119-128

一个植物种群体的空间分布大致可划分为两类 :离散分布与连续分布。然而隐藏在这种表观物理分布内部的遗传变异是十分复杂的。这种变异是如何分布的呢 ?这种分布又是如何维持的呢 ?因此 ,认识一个种的群体遗传结构有助于我们理解该种的进化过程 ,并提供为遗传资源保护做出决策的重要信息。本文对三大经典遗传结构模型 (岛屿模型、步石模型及距离隔离模型 )与渐变群理论及它们的异体和发展进行了详细的分析和评述。目前获得的许多不同类型的遗传标记使这些理论的应用得到不同程度的实现 ,但由于这些理论结论涉及到许多假设 ,在实际应用时应十分慎重。作者认为许多已建立的适合于动物群体遗传结构理论不能简单地直接应用于植物群体上 ,今后一个重要的研究内容就是要建立适合于植物群体的遗传结构理论  相似文献