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Natural treatment could make you almost invisible to mosquito bites
Mosquitoes are responsible for around 350 million human illnesses every year, with the number sure to increase as climate change bolsters the disease-carrying insect's numbers. A recent study even showed how another human impact, light pollution, may be responsible for extending the mosquito blood-drawing season.
New research into bite-protection has taken a readily available natural molecule, cellulose, and manipulated it to produce a product that saw an 80% reduction in mosquito feeds on human skin.
Cellulose, which is cheaply and abundantly sourced from the likes of wood industry waste, plus local food and paper waste, assembles into nanocrystals when treated with sulfuric acid. These cellulose nanocrystals (CNCs) assemble as a strong but transparent barrier film.
Scientists found that when mixed with water and a small amount of glycerol, these CNCs could be applied to the skin in a spray or gel and block the mosquito’s ability to bite through it to draw blood.
Adult female mosquitoes need blood from humans or animals to produce eggs, so a large reduction in this food source, particularly in highly populated areas, could have a positive impact on controlling the insect’s numbers.
CNCs and the efficient barrier they form have been in development for a wide range of ‘green’ uses, such as in soundproofing, removing dye from textiles and making strong binders like superglue and composite materials as tough as bone.
In trials with live Aedes aegypti mosquitoes, lead researcher Daniel Voignac from The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem and colleagues tested CNC-treated and non-treated hands, exposing skin for 10 minutes inside an enclosed cage of mosquitoes that contained an average of 15 females.
The result was the thin film of CNC gel acting like a chemical camouflage, with a drop of 80% in bites compared to a hand exposed to the insects without the biomaterial barrier.
Further studies showed that the CNC coat also blocked the passage of ammonium hydroxide vapor – a common mosquito attractant – when it was applied to filter paper and exposed to the insects.
The widespread Ae. Aegypti and Ae. Albopictus species are vectors for more than 22 serious arboviruses, including dengue, chikungunya, Zika, Japanese encephalitis, Rift Valley fever, yellow fever and West Nile viruses.
While in a preliminary stage, the research shows promise for the development of cheap, transparent natural compounds that could block the emission of the skin's chemicals that alert female mosquitoes to a blood feast. Green, inexpensive and scalable, it has the potential to push back against the worldwide problem of mosquito-borne illness.
注释：
bolster: v; n
1.v表示" 支持；鼓励"，means ""，如：Both sides offered statistics to bolster their arguments. 双方都拿出统计数字来支持他们的论点。
2. n表示" 长枕；靠垫"，means ""，如：There is a bolster across the head of the bed. 床头上有一个长枕垫。
cellulose: n
表示" 纤维素"，means "a polysaccharide that is the chief constituent of all plant tissues and fibers"，如：We need cellulose in paper making. 造纸时需要纤维素。
manipulate: v
表示" 操纵；操作；"，means " control or handle with skill"，如：A clever politician know how to manipulate public opinion. 聪明的政客知道如何操纵公众舆论。
nanocrystal: n
表示"纳米晶体"， 其中nano表示“pref. 表示“十亿分之一”；“毫微”；“纳米”，，如：Some factors such as atmosphere condition, protein, hydroxy radicel etc., which tend to be ignored generally, are the keys to controlling the shape and structure of nanocrystal. 诸如气氛、羟基、蛋白质等个别不被人们注意的因素有可能是影响纳米晶结构形貌的关键。
sulfuric： adj
表示"[化] 硫磺的；含硫的"，means "of or relating to or containing sulfur"，如：Most sulfuric acid is made by the contact process. 大多数的硫酸是用接触法制造的。
glycerol： n
表示" [化]甘油"，如：The gel is made from glycerol monolaurate. 这种凝胶由甘油单月桂酸酯组成。
soundproof: v
表示"隔音,消声"，means "insulate against noise"，如：The noise was baffled by the soundproof walls. 噪音被隔音墙壁阻挡住了。
dye: n
表示"染料；颜料；色素"，如：The dye doesn't take in cold water.那种染料在冷水中不起作用。
binder: n
1. 表示"粘合剂；"，means "something used to bind separate particles together or facilitate adhesion to a surface"，如：The cloth flower snaps on with a special binder. 这布花是用一种特殊的粘合剂固定住的。
2. 表示"活页夹"，means "holds loose papers or magazines"，如：A sheaf of loose papers is used to fill a notebook or binder.活页纸用来填在笔记本中或活页簿中的活页纸.
Jerusalem: n
表示" 耶路撒冷（巴勒斯坦城市）"，如：The pilgrims went forth to Jerusalem. 朝拜圣地者向耶路撒冷进发。
camouflage: v; n
表示" 伪装；欺瞒"，means "disguise by camouflaging; exploit the natural surroundings to disguise something"，如：The soldiers camouflaged themselves with leaves and branches. 士兵们用树枝树叶把自己伪装起来。They covered their tanks with leaves and branches as camouflage. 他们用树枝和树叶将坦克伪装起来。
biomaterial: n
表示"生物材料"，如：The biomaterial was replaced by connective tissue within 6 weeks. 在6周之内，此种生物材料逐渐被结缔组织取代。
ammonium: n
表示" 氨盐基"，means "the ion NH4 derived from ammonia;"，如：It is compatible with ammonium compounds. 它可与氨化合物混用。
Hydroxide： n
表示" 氢氧化物"，means"a compound of an oxide with water"，如：Sodium hydroxide is a kind of hydriodide. 氢氧化钠就是一种氢氧化物。
attractant: n
表示"引诱剂"，如：Female cockroaches emit a pheromone, or chemical attractant, to let males know they are ready to mate. 母蟑螂释放出一种费洛蒙，或称化学诱引剂，让公蟑螂知道她们已准备好要交配。
vector: n
1. 表示" 向量；矢量；"，means "a variable quantity that can be resolved into components"，如：Every vector can be resolved into covariant or into contravariant components. 每个矢量都可以分解成协变分量或逆变分量。
2. 表示"带菌者"，means "any agent (person or animal or microorganism) that carries and transmits a disease"，如：Mosquitoes are feared as vectors of malaria. 恐怕蚊子是疟疾的传播体。
arbovirus： n
表示"虫传病毒"，如：These signs are consistent with an arbovirus outbreak. 这些病症与虫媒病毒暴发相一致。
dengue: n
表示" [医]登革热"，如：Dengue is now found in more than 100 countries. 目前在100多个国家中发现了登革热病例。
chikungunya: n
表示" 基孔肯雅病"，means ""，如：Two kinds of mosquitoes carry chikungunya fever. 有两种蚊子能携带基孔肯雅热症。
Zika fever: n
表示" 蚊传热, 济卡热"，means ""，如：Keep away from that house. They have zika fever. 不要接近那一家，他们在患济卡热。
encephalitis： n
表示" 〈医〉脑炎"，如：Are encephalitis and meningitis same? How should recuperate? 脑炎和脑膜炎一样吗？要怎么调理？
scalable: adj
表示"可伸缩的"，means "capable of being scaled; possible to scale"，如：SharePoint sites are scalable for organizations of all sizes, ranging from a small team to a global corporation. SharePoint网站可针对各种大小的组织(从小型工作组到全球公司)调整规模。
borne: adj
表示" (用作复合词)由 ... 传播的；由 ... 传送的"，means ""，如：A voice was borne to us on the wind. 某种声音随风传到我们这里来。
中文简要说明：
蚊子是人类最大的健康杀手，这很重要，平均每年造成3.5 亿人患病，而且随着气候暖化，这一数字肯定会增加，所以防蚊工作愈来愈重要。一种使用奈米原理的防蚊液，可在皮肤表层塑造一层保护膜，免于被蚊子所查觉，这与以前的化学防蚊液原理不同，也就没有抗药性的问题。
新阿特拉斯(New Altas)报导，这种奈米防蚊液的以天然纤维素为基础，而纤维素又可从木材工业废料、纸张废料来加工。纤维素用硫酸处理时后，会形成纤维素纳米晶体 (CNC)，与水和少量甘油混合，制成的防蚊液，可以在皮肤表层形成一层坚固但透明的阻隔膜，有效阻止蚊子叮穿皮肤吸血，可减少 80%的蚊虫叮咬机率。
除了保护层可以挡住蚊子的叮咬以外，在滤纸实验上，还发现纤维素纳米晶体可以阻止氢氧化铵蒸气（汗臭味的分子，蚊子会被其引诱）的通过。
虽然目前处于初步实验阶段，但是该研究表明，在不使用化学挥发式驱蚊剂的辋况，也能使用廉价、透明的天然化合物，其目的是阻止皮肤释放吸引蚊子的化学物质，使蚊子感知不到，又在我们的皮肤上加装一层保护罩，双重防御，来解决恼人的蚊子问题。
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