5.Vaccines
5.疫苗
Beginning in the 1790s, when Edward Jenner developed the world's first vaccine against smallpox using a less virulent strain called cowpox to inoculate patients, vaccines have saved countless millions of lives. Since then, several different types of vaccines have been developed.
1790年，爱德华·詹纳发明了世界上第一支用"牛痘"的微毒菌株合成的疫苗。从那时起，人们开始注射疫苗来预防天花，芸芸众生也因此得到了拯救。随着时间的推移，各种疫苗也陆续得以面世。

Attenuated or "live" vaccines use live viruses that have been weakened or altered so that they do not cause illness, while inactivated or "killed" vaccines contain dead microorganisms or toxins that are usually used against bacterial infections. Some vaccines—including subunit and conjugate vaccines, as well as recombinant and genetically engineered vaccines—only use a segment of the infectious agent. When a vaccine is injected, the pathogen goes to work, but there is not enough of it to replicate at the rate it needs to in order to take hold. The body mounts an immune response, killing the pathogen or breaking down the toxin responsible for disease. The body's immune system now knows how to fight the disease and will "remember" if it comes across it again. In other words, scientists have figured out how to get a pathogen to help its own target defend itself against it. They have even taken the first steps toward developing vaccines for several forms of cancer, with three vaccines approved by the FDA for the hepatitis B virus (which causes liver cancer), human papillomavirus types 16 and 18 (which cause cervical cancers), and metastatic prostate cancer in some men.Thanks to vaccines, several diseases have been driven to virtual extinction. Smallpox is the most famous example, but polio, though not totally eradicated, comes in at a close second. Several other diseases might be gone by now if vaccines weren't so hard to come by in the underdeveloped nations that still struggle with them. Things are getting worse instead of better, with diseases coming in from an unexpected source: affluent, educated Westerners who should know better.Unfortunately, the anti-vaccination movement is making a comeback in regions where these diseases were once under control. Before the introduction of the measles vaccine in 1963, approximately 500,000 people per year were infected in the US, 500 of whom—mostly children—ended up dead. By 1983, there were only 1,497 cases reported, and after a brief resurgence in the '80s and '90s, reported cases were down to just 37 in 2004. After the anti-vaccination movement began gaining traction, 118 cases were reported in the US alone in 2011. That number keeps growing, fed by travelers coming in from areas with higher rates and finding less resistance. Whooping cough, once thought to be gone forever in the US, is also on the rise.
减毒活疫苗能对病毒进行改变或者减毒，因此，疫苗病毒并不会对人体健康产生威胁。另外，那些被杀灭了毒素的灭活疫苗则经常被运用到细菌感染的治疗中。而亚单位疫苗、合成疫苗、重组疫苗、基因工程疫苗则是利用病原体的一部分来制作疫苗。当人们接受完疫苗注射后，病原体便开始在体内发挥作用了。但是，人体内注射的病毒并不足以使它们有足够高的繁殖率以致在人体内扎根，随着少量病毒进入体内，人体的免疫反应也会增强，免疫系统会积极消灭病原体或者削弱毒物的致病几率。在经过一番"演习"后，人体免疫系统便有了与此类病毒的"作战经验"，并且能牢牢记住"敌人"面孔，在下一次同样的病毒"入侵"时便可以轻易"击败"它们。换句话说，科学家们弄明白了如何运用病原体帮助人类防御病毒的道理。科学家们甚至已经开始了癌症疫苗的初步研究，其中，已有三种疫苗得到了美国食品药品管理局的支持，这三种疫苗分别是：乙型肝炎病毒疫苗（该病毒通常导致肝癌）、乳头状瘤病毒16型和18型疫苗（该病毒通常导致宫颈癌）和针对男性的转移性前列腺癌疫苗。多亏了疫苗，很多疾病才被彻彻底底地消灭掉，天花就是一个典型的例子，另外，脊髓灰质炎这种疾病即使至今没有完全根除，但是它也离末日不远了。如果当初疫苗进入发展中国家更加顺利一些的话，许多其他疾病在当今也已不复存在了。但是，事情并没有那么乐观，病毒总是在人们意想不到的地方出现，因此，人们不该放松警惕，尤其是经济富裕、受教育程度高的西方国家的人们更应该重视这一问题。不幸的是，反疫苗接种运动使部分病情曾得到快控制的地区再次爆发疫情。在1963年麻风疫苗问世之前，美国每年大约有500,000人感染麻风病，其中大约500人是儿童，并且大多死亡。到了1983年，仅仅有1497例麻风病例被报道。在20世纪80年代到90年代间，除了一次短暂的爆发，2004年麻风病降低到仅仅37例。然而，在反疫苗接种运动受到追捧后的2011年，仅仅美国就报道了118例麻风病例。并且这个数字仍在持续增长，来自于各个地区的旅行者由于对病毒的抵抗力较弱，总是更容易感染上病毒。就连一度被认为在美国已经绝迹的百日咳也在逐渐出现。

4.Bacterial Waste Breakdown
4.细菌分解废物

Some of the smallest and simplest of creatures on Earth play some of the most important roles in safeguarding all of life. Bacteria have perhaps the most important role of all: breaking down and recycling waste.
地球上存在着一些十分简单而微小的生物，它们均在保护生命健康方面起着某些至关重要的作用。细菌可以分解废物并使其循环再利用，因此，细菌也许在这些生物身上扮演着最重要的角色。
The dead remains of animals and plants, along with the excrement of all organisms, contain vital nutrients and stored energy. Without a way to reclaim these nutrients, though, the available sources would be quickly depleted. Luckily, many bacterial species feed upon these energy sources, breaking them down to their smallest molecules and returning them to the soil, where they reenter the food chain.As helpful as this process already is, humans have found many ways to exploit it for a variety of even more advantages. Bacteria are used in sewage treatment, industrial waste management, and the clean-up of oil spills, leaked pharmaceuticals, and wastewater. They have also been useful in the development of aqua-farming, algae control, and waterless toilets. Researchers and engineers are currently looking into their potential use in the production of environmentally friendly bioplastics, glues, and building materials. They may even be used to break down plastic waste.
动植物的残余物，有机体的排泄物当中，都含有重要的营养物质，它们储存着大量的能量。但是，如果无法对这些营养物质进行回收再利用，这些可用资源就会很快枯竭。值得庆幸的是，许多细菌都靠这些能源才能得以生存，它们可以把这些能源分解成微粒，然后使其回到土壤里，以便它们再次进入食物链的循环系统里。这个过程十分值得借鉴，人类已经发现了许多方法利用这一过程来得到更多的益处。如今，细菌用于污水处理，工业废水处理，净化油溢出物、废水和泄露的药品。细菌也已经成功地用于淡水养殖，抑制藻类生长，还有无水马桶的使用。最近，研究人员和工程师们正在寻求细菌在环境友好型生物塑料、胶粘物以及建筑材料的进一步可用价值。细菌也许可用于分解塑料垃圾。

3.We Would Quickly Die Without Our Gut Bacteria
3.肠道细菌的缺失威胁我们的生命

Poorly understood until recently (and there is still quite a bit of research to be done), the natural bacteria that lives in our guts works with our immune system to drive out pathogens, produce vitamin K, stimulate peristalsis, and perhaps most importantly, digest our food. Without our gut bacteria, we wouldn't be able to perform any of these functions, and we would quickly die.
肠道中的生物细菌同我们的免疫系统一起发挥作用：驱除病原体，产生维生素k，促进肠道蠕动，还有最重要的一点，帮助消化食物，而这一点直到现在才被人们发现（尽管我们仍知之甚少还有待大量研究）。没有肠道细菌，这些功能都无法正常发挥作用，我们甚至会很快丧失生命。
The more we learn about beneficial strains of gut bacteria, the more we can incorporate that knowledge into healthy living. After it was determined that certain gut bacteria can play a role in obesity, probiotics became all the rage. Probiotics are the bacteria that reside in fermented foods and are now sold as supplements. Bacteria like some species of bifidobacteria, found in most yogurts, can create a highly acidic environment in which less-beneficial microorganisms cannot survive. Fatty foods and stress can also play a role in the health of our stomach flora, killing beneficial bacteria while favoring the more harmful kind that cause gas, bloating, and "leaky gut syndrome."In a huge breakthrough in the study of our gut bacteria and what they do, a team of Chinese and Danish researchers have recently developed a new way to identify these microorganisms using DNA sequence data. They identified over 500 species of benign bacteria and 800 new species of viruses that could live off them, providing hope for new ways to treat diseases associated with them, such as diabetes, obesity, and asthma.
我们关于肠道细菌中益菌菌株了解的越多，就能最大限度地用于健康生活。在确定了某些肠道细菌能有效针对肥胖之后，益生菌就风靡起来。益生菌是寄生于发酵食品中的一种细菌，人们将其当做补充食物销售。大多数酸奶中含有双歧杆菌，像这样的细菌菌种能创造一个酸性极高的环境，无益的微生物就不能存活。高脂肪食物和压力有害我们的肠道菌群，因为它们能够杀死益菌，那些有害的细菌便侵入身体，导致胀气，肿胀和"肠漏症候群"。研究肠道细菌以及它们的用处已经取得巨大进展，中国和丹麦组成了一支研究队伍，研究人员们发现了一种使用DNA序列数据的新方法来认证这些微生物。有500多种良性细菌已经被确定，还确定了800种人类赖以生存的新类病毒，这些发现给与其相关的疾病的治疗带来福音，比如糖尿病，肥胖症和哮喘的治疗。

2.Skin Bacteria Serve As Our First Line Of Immune System Defense
2.皮肤细菌作为我们的免疫系统的第一道防线

The moment you emerged from your mother's womb, you were set upon. They ambushed you in mere moments and colonized every inch of your skin, and they have been with you ever since. They are prokaryotes and other bacteria, and without the evolutionary partnership humans forged with them millions of years ago, you would have been dead soon after being born.
当我们的生命从母体受孕那一刻开始，就会遭受皮肤细菌的攻击。它们片刻之间便伏击了你，把你身体的每一寸肌肤变成它们的殖民地, 此后始终陪伴在你的左右。它们是原核生物和其他细菌，如果没有数百万年来，人类与它们之间产生的进化关系，你一出生便会夭折。
One of the most common skin bacteria is Staphlococcus epidermis, a bug that we now know plays a role in fighting off Leishmania major, the cause of a nasty disease called leishmaniasis that results in skin boils and open sores that don't heal. The good bug triggers an immune response called IL-1 that the body can't produce on its own, making Staphlococcus a necessary part of the human body, as vital to our existence as any organ.Prokaryotes, which also colonize the digestive tract, cover every exterior surface on the skin. Along with the rest of our beneficial skin microbiota, they became a part of us when they started competing against less-benevolent microorganisms for real estate. Along with the immune cells in our skin, they protect us against both pathogenic bacteria and opportunistic fungi that try to invade. This allows our bodies to spend less energy defending our exteriors and focus more on things like fighting viruses and precancerous cells.
最常见的一种皮肤细菌是表皮葡萄球菌, 它是一种现在众所周知的在对抗利什曼原虫上扮演了很重要角色的小虫,这种讨厌的疾病叫做利什曼病,它会导致皮肤疖和开放性溃疡。这种益虫会引发一种叫做IL-1的人类自身不能产生的免疫应答物质, 使得葡萄球菌成为如同对于人类生存同等重要的器官一般的人体至关重要的组成部分。原核生物在消化道开拓殖民地,覆盖每一寸皮肤外表面。连同剩下的一部份有益的皮肤菌群, 当它们开始与那些"不太友善"的微生物竞争领地时,它们成为了我们的一部分。连同我们皮肤的免疫细胞,它们保护我们免受病原菌和机遇性致病真菌的入侵。这使得我们的身体花费更少的精力保护我们的外部，把更多精力放在诸如如何对抗病毒和癌前细胞等上。

1.Life As We Know It Wouldn't Be Here Without Cyanobacteria
1.众所周知没有蓝藻细菌也就没有生命

Cyanobacteria, or blue-green algae, are possibly the oldest still-living species on Earth, with fossils dating back 3.5 billion years. They are unicellular bacteria that grow in colonies, and if it weren't for them, you wouldn't be here, and neither would nearly every other form of life.
蓝藻细菌、蓝藻很有可能是地球上仅存的最古老的物种,通过化石可以追溯到35亿年前。它们是聚居的单细胞细菌,要不是它们,你就不会在这里,几乎所有生命的形态也不复存在。
Cyanobacteria were the world's first photosynthesizers. They used energy from the sun along with chemicals in primordial oceans and inert nitrogen in the atmosphere to make their food. As a waste product, they generated oxygen, a poison to virtually every other form of life at that time and the cause of early mass extinction events. Over a period of roughly 300 million years, all this oxygen generation helped form the atmosphere as we know it, during the Archaean and Proterozoic eras.That wasn't the only way this bacteria kick-started life as we know it. Sometime during the Proterozoic or early Cambrian era, they formed a symbiotic relationship with certain eukaryote cells, making food for the cell in return for a stable environment to call home. These were the first plants, as well as the origin of eukaryotic mitochondria, which is essential for animal life. This truly titanic event is now known as endosymbiosis.While several forms of cyanobacteria are toxic, a species named Spirulina was an important food source for the Aztecs and eaten regularly by many Asian nations. Today, it is often sold in powder or tablet form as a health food supplement.
蓝藻是世界上第一个光合作用系统，它们利用来自太阳的能源和原始的海洋的化学物质和大气中的惰性氮合成它们的食物。至于废料,它们将其生成氧气——对于当时几乎每一个其它的物种生命来说相当于毒药,也是最早期大规模物种灭绝事件的成因。大约3亿年前的一段时间内, 在太古代和元古代时期所有这些氧气制造有助于形成我们所知道的大气层。这不是我们所知道的这种细菌开启生活的唯一途径。在元古代和早寒武纪时期的某个时候,它们与某些真核生物细胞形成了一种共生关系,它们为细胞提供食物以换取一个称之为家的稳定环境。这些真核线粒体的鼻祖是最初的植物,这对于动物生命是至关重要的。然而有一些形式的蓝藻是有毒的,一个命名为阿兹特克螺旋藻的物种是阿兹特克人重要的食物来源，被许多亚洲国家的人经常食用。如今,它经常以粉末还有片剂的形式作为健康的食品保健品。

翻译:murphy 来源:前十网