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  • 摘要:

    改革新形势下,“能源革命”和新一轮电力体制改革进一步提升了新能源的战略地位,对新能源发展提出更高要求。

    以新能源为支点的能源转型成为当前我国能源发展的新趋势,国家战略明确提出大力发展新能源,并制定了阶段性发展目标

    能源转型是世界各国能源发展的大趋势。世界各国都在积极探索未来能源转型发展路线,并将发展新能源和可再生能源作为推动未来能源转型的重点,美欧日等发达国家陆续出台了以支撑新能源发展为重点的能源发展战略。

    我国经过30余年经济发展,以化石能源为主的能源生产和消费规模不断增加,国内资源环境约束凸显,迫切需要大力发展新能源,加快推进能源转型。当前,以新能源为支点的我国能源转型体系正加速变革,大力发展新能源已上升到国家战略高度,成为顺应我国能源生产和消费革命的发展方向。

    改革新形势下,“能源革命”和新一轮电力体制改革进一步提升了新能源的战略地位,对新能源发展提出更高要求

    李克强总理在新一届国家能源委员会首次会议强调,推动能源生产和消费方式变革,提高能源绿色、低碳、智能发展水平;习主席在中央财经领导小组第六会议中,明确提出要推动能源生产和消费革命,建立多元供应体系。立足国内多元供应保安全,大力推进煤炭清洁高效利用,着力发展非煤能源,形成煤、油、气、核、新能源、可再生能源多轮驱动的能源供应体系。

    中共中央文件〔2015〕9号《关于进一步深化电力体制改革的若干意见》提出完善并网运行服务,支持新能源、可再生能源、节能降耗和资源综合利用机组上网,积极推进新能源和可再生能源发电与其他电源、电网的有效衔接,依照规划认真落实可再生能源发电保障性收购制度,解决好无歧视、无障碍上网问题。同时,提出开放电网公平接入,建立分布式新能源发展新机制,有序向社会资本放开配售电业务。

    所属服务: 可再生能源专项服务 | 点击量:2
  • 摘要:

    能源是人类社会生存发展的重要物质基础, 攸关国计民生和国家战略竞争力。 当前, 世界能源格局深刻调整, 供求关系总体缓和, 应对气候变化进入新阶段, 新一轮能源革命蓬勃兴起。 我国经济发展步入新常态, 能源消费增速趋缓,发展质量和效率问题突出, 供给侧结构性改革刻不容缓, 能源转型变革任重道远。 “ 十三五” 时期是全面建成小康社会的决胜阶段, 也是推动能源革命的蓄力加速期, 牢固树立和贯彻落实创新、 协调、 绿色、 开放、 共享的发展理念, 遵循能源发展“ 四个革命、 一个合作” 战略思想, 深入推进能源革命, 着力推动能源生产利用方式变革, 建设清洁低碳、 安全高效的现代能源体系, 是能源发展改革的重大历史使命。

      本规划根据《 中华人民共和国国民经济和社会发展第十三个五年规划纲要》 (以下简称“ 十三五” 规划纲要)编制,主要阐明我国能源发展的指导思想、 基本原则、 发展目标、重点任务和政策措施, 是“ 十三五” 时期我国能源发展的总体蓝图和行动纲领。

    所属服务: 可再生能源专项服务 | 点击量:3
  • 摘要:

    Mechanism behind the electric charges generated by photosynthesis

    Photosynthesis requires a mechanism to produce large amounts of chemical energy without losing the oxidative power needed to break down water. A Japanese research team has clarified part of this mechanism, marking another step towards the potential development of artificial photosynthesis. The findings were published on February 27 in the online edition of The Journal of Physical Chemistry Letters.

    The team was led by Professor KOBORI Yasuhiro (Kobe University Molecular Photoscience Research Center) and PhD student HASEGAWA Masashi (Graduate School of Science) with Associate Professor MINO Hiroyuki (Nagoya University Graduate School of Science).

    During the water-splitting reaction in photosynthesis, plants produce oxygen by converting solar energy into chemical energy, providing the energy source necessary for their survival. This reaction is carried out by a protein complex in chloroplasts (located in leaves) called the photosystem II complex.

    In 2015 Professor Kobori's research team succeeded in analyzing the electronic interactions and 3-dimensional placement of the initial charge separation produced directly after photoreaction in the photosynthetic reaction center of purple bacteria, which do not cause the oxidation potential for water-splitting. However, in the photosystem II complex for higher plants, the configuration of the initial charge separation state was unclear, and it was a mystery as to how it led to an effective water-splitting reaction while retaining the high oxidative power.

    The scientists extracted thylakoid membranes (where the photoreaction takes place in photosynthesis) from spinach, added a reducing agent, and irradiated the samples. This enabled them to detect microwave signals from the initial charge separation state to a degree of accuracy of a 10 millionth of a second. They developed a method of analyzing the microwave signals using spin polarization imaging. For the first time it was possible to carry out 3D view analysis of the configuration of the electric charge produced directly after exposure to light as a reactive intermediate. This was done with an accuracy to within 10 millionth of a second, as consecutive photography. Based on this visualization, they also quantified the electronic interaction that occurs when electron orbits overlap for molecules with electric charges.

    The initial electric charge separation structure clarified by this analysis was not very different from the structure before the reaction, but the imaging analysis showed that the positive electric charge that occurred in the pigment as a reactive intermediate existed disproportionately in chlorophyll single molecules. It suggests that there is strong stabilization caused by electrostatic interaction between the charges.

    It has been revealed that the return of the negative charge is suppressed, since the overlap between electron orbits is greatly limited by the insulating effect of the vinyl group terminus. This means that it becomes possible to use the high oxidizing powers of the positive charge in chlorophyll (PD1) for the subsequent oxidative decomposition of water.

    Based on these findings, researchers have unlocked part of the mechanism to effectively produce high amounts of chemical energy without loss of the oxidative power needed to split water in photosynthesis. These findings could help to design an "artificial photosynthesis system" that can provide a clean energy source by efficiently converting solar energy into large amounts of electricity and hydrogen. The application of this principle could contribute to solving issues with energy, the environment and food shortages.

    Journal Reference:

        Masashi Hasegawa, Hiroki Nagashima, Reina Minobe, Takashi Tachikawa, Hiroyuki Mino, Yasuhiro Kobori. Regulated Electron Tunneling of Photoinduced Primary Charge-Separated State in the Photosystem II Reaction Center. The Journal of Physical Chemistry Letters, 2017; 8 (6): 1179 DOI: 10.1021/acs.jpclett.7b00044

    所属服务: 土壤、生物与环境 | 点击量:14
  • 摘要:

    Atomic structure reveals how cells translate environmental signals

     

    Culminating a nearly 10 year effort, researchers have determined the atomic resolution structure of a key molecule that translates signals from a cell's local environment into a language that the cell can understand and use. The determination of the architecture of the Inositol Tris-Phosphate Receptor (IP3R) had long been considered a major goal in biomedical research because of its strategic role inside cells as a molecular train station for transferring signals that control many cell functions. The structure is expected to contribute to the development of better therapeutic approaches for many diseases. The work was conducted by a team at RIKEN Brain Science Institute under the direction of Professor Katsuhiko Mikoshiba, whose laboratory cloned the first IP3R gene in 1989.

    In all living cells, chemical signals are harnessed for intracellular communication. The inositol 1,4,5-trisphosphate (IP3) is one such signal that binds to the IP3 receptor (IP3R) to release calcium ions (Ca2+) from intracellular Ca2+ stores such as the endoplasmic reticulum. The IP3R-embedded Ca2+ stores are distributed in various microdomains within cells and have pivotal roles in processes as diverse as neural communication, differentiation, plasticity, and metabolism. Of the three genes identified, the brain dominant type 1 IP3R (IP3R1) is genetically causative for spinocerebellar ataxia 15/16/29 and Gillespie syndrome, and regulates cellular waste disposal processes implicated in the etiology of neurodegenerative diseases including Alzheimer's disease. Although the important roles of IP3R in normal and disease conditions are well known, understanding how IP3 signals trigger the opening of the Ca2+ channel was elusive.

    The new IP3R1 crystal structure reveals a rich cosmos of atomic scale details on its function. IP3R1 is a micromachine of 20 nm in diameter that contains two functional sub-structures, an IP3 binding site and a Ca2+ channel pore. The distance from the IP3-binding site to the channel pore is 7 nm, the longest among similar ion channels, and the fundamental question of how IP3-binding physically opens the channel from a long range has been unanswered in the decades since the gene was cloned. X-ray crystallography of the large cytosolic domain of a mouse IP3R1 in the absence and presence of IP3, at the RIKEN SPring-8 ion beam factory, pinpointed a long-range mechanism involving an IP3-dependent global movement of a part of the receptor called the curvature α-helical domain that serves as a bridge between the cytosolic and channel domains. Mutagenesis of this bridge revealed the essential role of a leaflet structure in the α-helical domain that relays IP3 signals to the channel, and may help to explain how long-range coupling from IP3 binding to the Ca2+ channel occurs.

    The findings reveal similarities and differences with a recently published report on the IP3R using a completely different method called cryo-electron microscopy. In the related study, a group led by Irina Serysheva from the University of Texas Health Science Center at Houston proposed that channel activation by IP3 may occur by direct binding of the C-terminus and IP3-binding domain and coupling from the IP3-binding domain to neighboring subunits. The current data disagree with these conclusions, instead suggesting that IP3-binding site to the leaflet region underlies the dynamic structural changes by IP3. A comparison of the two structures reveals agreement on an immobile part of the curvature helical domain and a variable arrangement of other helical domains. The authors hypothesize that the immobile section would act as a rigid-body conducting a torque from IP3-binding sites to the channel domain, whereas the flexible regions would contribute to the dynamic properties of IP3R function.

    Resolving the long-standing mystery of long-range communication that allows IP3 to open the channel will aid future rational drug design targeting the receptor that could allow a more diverse range of therapeutic avenues. The findings may also clarify IP3R roles in cellular senescence and tumor suppression linked to selective vulnerability of cancer cells. Surprisingly, the study also clarifies a role of IP3Rs in the function of pathogenic unicellular organisms like Trypanosoma cruzi, the parasite of Chagas disease, and brucei, that causes African trypanosomiasis or sleeping sickness. The team identified an amino acid sequence in the leaflet that is conserved in parasites, suggesting structural insights that may assist in drug discovery for these devastating conditions.

    Journal Reference:

        Hamada K, Miyatake H, Terauchi A, Mikoshiba K. IP3-mediated gating mechanism of the IP3 receptor revealed by mutagenesis and X-ray crystallography. Proceedings of the National Academy of Sciences, April 2017 DOI: 10.1073/pnas1701420114

    所属服务: 土壤、生物与环境 | 点击量:20
  • 摘要:

    Electronics to control plant growth

     

    A drug delivery ion pump constructed from organic electronic components also works in plants. Researchers from the Laboratory of Organic Electronics at Linköping University and from the Umeå Plant Science Centre have used such an ion pump to control the root growth of a small flowering plant, the thale cress (Arabidopsis thaliana).

    In the spring of 2015, researchers from the Laboratory of Organic Electronics at Linköping University presented a microfabricated ion pump with the ability to pump in the correct dose of a naturally occurring pain-relief agent exactly where it was needed. This was a first step towards effective treatment of such conditions as chronic pain. In the autumn of the same year, the researchers presented results showing how they had caused roses to absorb a water-soluble conducting polymer, enabling them to create a fully operational transistor in the rose stem. The term "flower power" suddenly took on a whole new meaning.

    "Around 10 years ago, we started considering applying our ion pump drug delivery devices to plants. It wasn't until several years later that we teamed up with Professor Markus Grebe and colleagues at the Umeå Plant Science Centre and finally discovered that the ion pump could be of great use to plant biologists, says Daniel Simon, Associate Professor and head of the organic bioelectronics research area in the Laboratory of Organic Electronics, Linköping University.

    Assistant Professor David Poxson, Laboratory of Organic Electronics, teamed up with the group´s chief chemist, Assistant Professor Roger Gabrielsson, to develop new ion pump materials capable of transporting and delivering powerful plant signalling compounds such as the hormone auxin.

    Dr. Poxson then worked closely with biologists at the Umeå Plant Science Centre to investigate highly-resolved delivery of auxin to the roots of living thale cress, Arabidopsis thaliana. This plant is to plant biologists what the fruit fly Drosophila is to researchers working in animal research: a major model organism.

    The result: Electronically-controlled gradients of plant hormone were taken up by the roots. Dr. Poxson and co-author Dr. Michal Karady followed the internal auxin response with the help of fluorescent reporter proteins that change their fluorescence intensity in the presence of auxin. They observed that the internal auxin response and even the roots´ growth rate could be controlled by the ion pump delivery of auxin.

    "We have accomplished a ground-breaking step for plant research by our multidisciplinary effort," says Markus Grebe. "Several research groups from Umeå Plant Science Centre and Linköping University have been involved. The pump will likely allow us to locally apply not only auxin but also a variety of other hormones to plants in an electronically controlled manner. This will help us to study the impact of these hormones on plant growth and development at tissue and cellular resolution."

    "These new DendrolyteTM materials also paves the way for future ion pump capabilities in a variety of areas, for example delivery of larger aromatic compounds like plant hormones or even certain pharmaceuticals," says Daniel Simon.

    "This is an important advance: we now know not only that we can use the ion pump in plants, but also that we can regulate their physiology and growth," says Professor Magnus Berggren, head of the Laboratory of Organic Electronics.

    Journal Reference:

        David Poxson, Michal Karady, Roger Gabrielsson, Aziz Alkattan, Anna Gustavsson, Siamsa Doyle, Stéphanie Robert, Karin Ljung, Markus Grebe, Daniel T Simon and Magnus Berggren. Regulating plant physiology with organic electronics. PNAS, 2017 DOI: 10.1073/pnas.1617758114

    所属服务: 土壤、生物与环境 | 点击量:19
  • 摘要:

    Scientists discover gene that influences grain yield

     

    Researchers at the Enterprise Rent-A-Car Institute for Renewable Fuels at the Donald Danforth Plant Science Center have discovered a gene that influences grain yield in grasses related to food crops. Four mutations were identified that could impact candidate crops for producing renewable and sustainable fuels.

    In a paper published April 18, 2017, in Nature Plants, a team led by Thomas Brutnell, Ph.D. Director of the Enterprise Institute for Renewable Fuels at the Danforth Center and researchers at the U.S. Department of Energy Joint Genome Institute (DOE JGI), a DOE Office of Science User Facility, conducted genetic screens to identify genes that may play a role in flower development on the panicle of green foxtail. Green foxtail is a wild relative of the common crop foxtail millet. These Setaria species are related to several candidate bioenergy grasses including switchgrass and Miscanthus and serve as grass model systems to study grasses that photosynthetically fix carbon from CO2 through a water-conserving (C4) pathway. The genomes of both green foxtail and foxtail millet have been sequenced and annotated through the DOE JGI's Community Science Program.

    "We have identified four recessive mutants that lead to reduced and uneven flower clusters," said Pu Huang, Ph.D., the lead author of the paper. "By ultimately identifying the gene in green foxtail we identified a new determinant in the control of grain yield that could be crucial to improving food crops like maize."

    The grass Setaria has been proposed as a model for food and bioenergy crops for its short stature and rapid life cycle, compared to most bioenergy grasses. After constructing a mutant population resource for the grass, the Brutnell lab screened 2,700 M2 families, deep sequenced a mutant pool to identify the causative mutation and confirmed a homologous gene in maize played a similar role.

    "Identifying this new player in panicle architecture may enable the design of plants with either enhanced or reduced panicle structures," stated Brutnell. "For instance, maize breeding has selected for reduced male panicles, also known as tassels, to reduce shading in the field while still producing sufficient pollen. However, grain yields in sorghum are directly related to the architecture of the panicle. By showing that this gene influences panicle architecture in Setaria and maize, we have expanded the tool box for breeders."

    At the Danforth Center, plants hold the key to discoveries and products that will enrich and restore both the environment and the lives of people around the globe. Brutnell's lab research includes the search for the next generation of biofuels: alternative sources of energy that are affordable, sustainable and ecologically sound. The research develops novel computational tools and model systems to identify genes that will improve yield in crops through enhanced photosynthesis.

     

    Pu Huang, Hui Jiang, Chuanmei Zhu, Kerrie Barry, Jerry Jenkins, Laura Sandor, Jeremy Schmutz, Mathew S. Box, Elizabeth A. Kellogg, Thomas P. Brutnell. Sparse panicle1 is required for inflorescence development in Setaria viridis and maize. Nature Plants, 2017; 3 (5): 17054 DOI: 10.1038/nplants.2017.54

    所属服务: 土壤、生物与环境 | 点击量:16
  • 摘要:

    根据澳大利亚农业资源经济科学局(Australian Bureau of Agricultural and Resource Economics and Sciences, ABARES)关于澳大利亚蜜蜂产业的报告显示,养蜂业平均现金收入7.04万美元,在塔斯马尼亚岛、维多利亚州和新南威尔士州的收入明显还要更高。

    ABARES农业生产力和农场分析部的执行助理部长大卫•加莱亚诺(David Galeano)表示,这份报告的调查结果为政府和投资者对该产业进行分析提供了重要的数据。

    蜜蜂产业是澳大利亚经济重要的一部分,2014-15年总产值约1.01亿美元.行业调查发现,2014-15年大多数养蜂业收入来自于蜂蜜销售(占现金收入的85%)。有偿授粉排在第二位(占11%), 44%的养蜂人进行了有偿授粉业务。养蜂利润大致与业务规模成正比增长。然而,如果养蜂人的蜂房少于200间,平均利润就不容乐观。”

    70%的养蜂从业者认为干旱是蜂蜜生产的一大挑战;50%的人认为使用农业化学物质会对可利用的花卉资源造成不良影响,从而影响蜂蜜产量。从生物安全的角度看,影响养蜂人员最普遍的病害和虫害是白垩病和小蜂巢甲虫。最严重的利益损失就是由小蜂巢甲虫病和美洲幼虫腐臭病造成的。

    作为2016年ABARES澳大利亚蜜蜂产业调查的一部分,澳大利亚的蜜蜂产业报告是经过分析从养蜂行业收集来的财政和物理性能数据而得出的。这次调查由农业和水资源部进行资金支持,得到了农业与地区事务及运输参考委员会(Rural and Regional Affairs and Transport References Committee)2014年关于澳大利亚未来养蜂及授粉服务产业的指导建议。

    所属服务: 食物与营养 | 点击量:47
  • 摘要:

    全球环境情况难于预测。然而,最近美国农业部(USDA)公布了对未来10年的预测,指出了粮食及农产品需求背后的种种趋势以及美国的多项农业生产趋势。这些预测意义非凡,能帮助读者计算不同价格升降情景下的种种概率。

    报告显示,农业支出上升,收入下降(尤其是在畜牧业领域)将会削减2017年美国13%的净现金收入。这是继2015年美国农场净现金收入缩水20%,2016年再缩水15%以后的又一明显下滑。该缩水趋势将于2018年开始改善,届时美国农场年支出将以1%-2%的速度增长,而收入也将同步(甚至略快速)增加。

    2017-2026年各行业预测

    粮食及油籽

    (1)玉米播种面积将稳步下降,而美国玉米需求将不断增加。

    受通胀及收入成本因素影响,玉米价格不断下降,进而将导致种植面积下降。而玉米单产提升将支撑产量,满足不断增长的饲料及出口需求。生产率提升也将小幅提高美国农产品生产者的净收入。

    (2)2017年大豆种植面积将一次性跃升。

    价格将维持在9美元左右。由于世界各国油籽需求强劲,2023年以前大豆净收入将高于玉米净收入。

    (3)小麦价格将是粮食价格平稳的例外情况。

    美国种植面积下降,加之出口需求强劲,将消耗美国粮食库存。北美市场将于2017年回暖,但幅度仍有待确定。

    牛肉、猪肉及家禽

    (1)所有畜牧品种生产均会提升。

    最近美国肉牛饲养量增加,上市体重提高,表明2017年牛肉供给将增加。2018-2026年牛肉与饲料价格比下降,生产增量也会同步放缓。

    (2)美国猪肉市场增速将高于牛肉和禽类,达年均1.3%。

    到2026年,猪肉产量将略高于牛肉产量。

    (3)嫩鸡及火鸡产量较过去10年将有所放缓。

    全球出口需求将主导产量的增长。

    乳业生产

    (1)美国牛奶生产至2026年将以年2.2%的速度增加。

    饲料价格走低,牛奶价格回升将推升乳畜群规模。乳脂需求将提高,液态奶需求将下降。

    (2)美国牛奶产量提高将促进乳制品出口,尤其是高固体份脱脂产品的出口。

    美国乳品出口量将占乳品生产(按乳脂或标准奶计)的4.9%,并将于2026年上升至21%(按固体脱脂标准奶计)。 

    所属服务: 食物与营养 | 点击量:43
  • 摘要:

    根据美国农业部国家农业统计局(U.S. Department of Agriculture’s National Agricultural Statistics Service, USDA-NASS)今天发布的2016年作物生长报告(Crop Production 2016 Summary),得益于中部地区充足的降雨和适宜的温度,2016年美国主要农作物玉米和大豆的产量再创高产记录。

    美国玉米总产量达151亿蒲式耳,比2015年增产11%。每英亩产量174.6蒲式耳,比上年平均增产6.2蒲式耳。玉米收获面积为8,670万英亩,比上年增加7%。2016年玉米目标产量数据表明,主产州玉米目标产量每英亩穗数达史上第三高水平,其中,俄亥俄州每英亩穗数突破历史记录。

    2016年美国大豆总产量达到创纪录的43.1亿蒲式耳,比2015年增长10%。从大平原北部到阿巴拉契亚山脉,几乎整个北美的大豆产量创历史新高,由此,大豆平均单产高达52.1蒲式耳,比上年增加4.1蒲式耳。2016年大豆收获面积也创下新高,达8,270万英亩,比上年增加1%。

    2016年,美国棉花的总产量比2015年增加32%,达到1,700万包(每包480磅)。每英亩产量为855磅,比去年增加89磅。总收获面积为952万英亩,比上年增加18%。

    2016年美国高粱总产量达4.8亿蒲式耳,比2015年下降20%。种植面积为669万英亩,比上年下降21%。收获面积为616万英亩,比上年下降22%。高粱单产预计将达到创纪录的77.9蒲式耳,比去年增加1.9蒲式耳。乔治亚州,堪萨斯州和内布拉斯加州的产量创历史新高。

    今天公布的还有冬小麦、油菜种子以及谷物仓储报告。冬小麦种子的报告是今年冬小麦种植面积的首个指标。2017年冬小麦种植面积约为3,240万英亩,比2016年下降10%,比2015年下降18%,这使得2017年美国冬小麦种植面积成为历史次低水平。

    谷物仓储报告显示,2016年玉米和大豆的储量比2015年分别增加10%和7%。玉米的仓储总量为124亿蒲式耳,大豆的仓储总量为29亿蒲式耳。小麦的仓储总量比去年增长了19%,达到20.7亿蒲式耳。

    报告总结了2016年谷物、干草,油籽,棉花、烟草、糖,豌豆、干豆、扁豆,土豆和杂类作物的收获面积、产量和产量估计。

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  • 摘要:

    德国发布26个欧洲国家就高致病性禽流感病毒(HPAIV)H5N8的检测报告。报告显示病毒正在快速蔓延,该疫情在空间上正在快速扩散。欧洲不同地区的禽流感案例每日增加;动物园以及野生动物园的鸟类也受到波及。德国野生鸟类和禽类感染禽流感病毒的数量已达69例,达到前所未有的水平。

    野生鸟类

    虽然在2014年与2015年爆发的H5N8疫情中,只在个别看起来并无异样的野生鸟类(三只野鸭,一只水鸭和一只海鸥)中发现H5N8禽流感病毒,但目前已在大量死去的水禽和吃腐肉的猛禽(如秃鹰、白尾鹰和海鸥)体内发现禽流感病毒。截止到目前,已在47种不同的鸟类物种中检测到该病毒,包括潜鸭、水鸟、海鸥、天鹅等鸟类,以及个别案例中的野鸭、鹅、猛禽和吃腐肉的鸣禽(例如乌鸦)。健康的水禽体内或其粪便中也检测出了H5型禽流感病毒,这表明了一种可能性:野生鸟类可以将该病毒排泄出体外而不导致疾病或死亡。已经得出的结论是,在野生水鸟中H5N8禽流感病毒正在持续蔓延,并且已发现的死禽只是冰山一角。

    如果天气继续寒冷下去,鸟类会继续迁徙。大多数水鸟选择离开寒冷的地区,前往无冰的水域。这种天气条件可能导致疫情在内陆地区和南欧的野生鸟类中扩散。

    家禽与动物园/野生动物公园

    德国已有 54个家禽饲养场和15个动物园或野生动物园感染了H5N8型禽流感病毒。几乎所有感染病毒的饲养场都位于已发现众多死亡的、呈高致病性禽流感病毒阳性的水禽的地区内。在爆发疫情的野生动物园中,很有可能接触到野生水鸟的水禽受到了波及。在大多数家禽饲养场中,直接或间接接触受污染材料(鞋、车辆、物体)是最可能的感染途径。德国弗里德里希洛弗勒研究所(FLI)调查发现,所有疫情中,通过购买家禽、饲料和饮用水可能被感染的风险都被忽略了。受感染的地区的大多数是初次爆发疫情,并没有进一步扩散。但有三例疫情很可能是二次爆发。在野生鸟类和家禽可能接触的地区,很有可能爆发以及扩散疫情,并产生新的感染源。

    系统发育分析

    遗传分析显示,该病毒与在2016年夏天首次在俄罗斯南部检测到的H5N8病毒相似。该病毒与在2014年与2015年在欧洲爆发的H5N8病毒具有显著遗传性差异。因此,该病毒很可能是最新引入的,且传播途径与2014年的途径相同,即在俄罗斯通过野生鸟类传播。系统发育分析认为,从中亚到中欧的过程中,发生了至少一种其他禽流感病毒的基因重组事件。通过购买家禽和家禽产品从中国或邻近亚洲国家直接引入病毒是不太可能的,因为在这种情况下,病毒会呈现其他遗传规律。疫情爆发调查的结果表明,没有任何迹象表明德国感染疫情的饲养场与东亚或东南亚地区感染疫情的饲养场有任何直接关联。(必须指出,所有受高致病性禽流感影响的国家均已禁止进口家禽和家禽产品)。已在水禽中发现的禽流感病毒,与在2014年与2015年流行的病毒相比,和当前H5N8病毒经过变化的基因组片段构成有一定关联。

    自2016年12月中旬起,H5N5亚型禽流感病毒在野生鸟类中爆发,该病毒现已首次蔓延至家禽饲养场。这种病毒是原始H5N8病毒的重组。如果几种亚型病毒存在于同一受感染的动物中并且在复制期间交换遗传物质,则产生了混合型病毒,被称作重组。H5N5病毒的首例分析也显示其与来自俄罗斯-蒙古边境地区的H5N8病毒有一定联系。它似乎与H5N8同时或在其不久后进化,但与H5N8具有遗传性差异,之后被引入德国。当致病性或高或低的流感病毒在一个群体中感染时,总是会产生病毒重组。

    至今,尚未发现人感染H5N8或H5N5禽流感病毒的案例。

    结论与建议

    由于高致病性禽流感病毒H5N8在26个欧洲国家的野生鸟类中以及德国15个州中蔓延,估计很有可能会通过野生鸟类和家禽之间的直接与间接接触而致使病毒被引入家禽饲养场或动物园中,尤其是水鸟休息区和聚集区,包括野生鸟类聚集的农田。

    当前的首要任务是保护国内家禽饲养场不被感染H5N8病毒。重点是在野生鸟类栖息地和家禽饲养场之间建立物理性和功能性隔离。将家禽在室内饲养以及采取其他生物安全措施可以最大程度降低其与被感染野生鸟类直接和间接接触的风险。尤其是间接传播途径,例如受到野鸟污染的饲料,必须与水和受污染的垃圾和物品(鞋、手推车、车辆等)相隔绝,并采取适当的消毒措施。必须防止家禽饲养场之间的病毒传播。这需要实施严格的生物安全措施,特别是对设备和车辆进行清洁和消毒。生物安全措施的修订、优化以及严格执行至关重要。家禽饲养者有义务依据法律遵守基本的生物安全规则。

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