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2018年12月10日 16:37:43

宜昌市那里作包皮手术好Science and technology科学技术The Brain Activity Map绘制大脑活动地图Hard cell棘手的细胞An ambitious project to map the brain is in the works. Possibly too ambitious一个绘制大脑活动地图的宏伟计划正在准备当中,或许有些太宏伟了NEWS of what protagonists hope will be Americas next big science project continues to dribble out.有关其发起人心中下一个科学大工程的新闻报道层出不穷。A leak to the New York Times, published on February 17th, let the cat out of the bag, with a report that Barack Obamas administration is thinking of sponsoring what will be known as the Brain Activity Map.2月17日,《纽约时报》刊登的一位线人报告终于泄露了秘密,报告称奥巴马政府正在考虑赞助将被称为大脑活动地图的计划。And on March 7th several of those protagonists published a manifesto for the project in Science.3月7日,部分发起人在《科学》杂志上发表声明实了这一计划。The purpose of BAM is to change the scale at which the brain is understood.大脑活动地图计划的目标是改变人们在认知大脑时采用的度量方法。At the moment, neuroscience operates at two disconnected levels.眼下,神经学的研究处在两个断开的层次。The higher one, where the dimensions of features are measured in centimetres, has many techniques at its disposal, notably functional magnetic-resonance imaging, which measures changes in tissues fuel consumption.在相对宏观的层次当中各个特征的规模用厘米来衡量,有很多技术可以使用,尤其是用来测量组织中能量消耗变动情况的核磁共振成像技术。This lets researchers see which bits of the brain are active in particular tasks—as long as those tasks can be performed by a person lying down inside a scanner.该技术可使研究人员找出在完成具体的任务时,大脑的哪些部分处于活跃状态。At the other end of the scale, where features are measured in microns, lots of research has been done on how individual nerve cells work, how messages are sent from one to another, and how the connections between cells strengthen and weaken as memories are formed.而另一个度量的层次则要求用微米来测量各种特征,这一层次的研究很多都是关于单个神经细胞是如何工作的、信息在神经细胞之间是如何传递的以及当产生记忆的时候神经细胞之间的联系是如何得到加强和减弱的。Between these two, though, all is darkness.然而,位于这两个层次之间的研究还处于一片漆黑当中。It is like trying to navigate America with an atlas that shows the states, the big cities and the main highways, and has a few street maps of local neighbourhoods, but displays nothing in between.这就好比当你要在美国寻找自己的前进方向时,手里却只有一副如下的地图册:上面只显示各州轮廓、各都市的坐落点、干线公路以及一些社区街道,除此之外别无它物。BAM, if all goes well, will yield plans of entire towns and villages, and start to fill in the road network.如果大脑活动地图计划进展顺利的话,就能得到完整的城市和村落规划图,道路网也将完善。It will also, to push the analogy to breaking point, let a user look at actual traffic flows on the roads in question, and even manipulate the road signs, in order to understand how particular communities work.它还能使用户能够看到自己备选道路的实际交通情况,甚至还能通过操纵道路标志来了解具体地区是怎样运作的,将脑图、地图这一类比给打破。The mappers aim is to find out how nerve cells collaborate to process information.制图者的目标是找出神经细胞是如何共同处理信息的。That means looking at the connections between hundreds, thousands and even millions of adjacent cells—and doing so, crucially, while those cells are still alive, rather than after they have been sliced and diced for microscopic examination.这就意味着要研究成百上千甚至上百万的相邻细胞之间有何种关联,关键在于这一研究还要在这些细胞存活的时候进行,而不是把它们切片后放在显微镜下观察。This will require a new set of tools.要做到这一点就需要一套新的工具。And the guts of the BAM proposal are that the American taxpayer should provide those tools.大脑活动地图提案的大胆之处在于它认为美国纳税人应该出钱提供这些工具。It is thus no coincidence that the lead author of the paper, Paul Alivisatos, the director of the Lawrence Berkeley National Laboratory, is a materials scientist, not a neuroscientist.因此,由材料学家保罗?阿里维萨多而非神经学家来主笔该提案并非什么巧合。Dr Alivisatos and his ten colleagues would like their new tools to be able to record, simultaneously, the activity of millions of nerve cells.阿里维萨多士和他的10个同事希望他们的新工具能同时记录数百万神经细胞的活动情况;Then, having done the recording, they would like a second toolkit that lets them manipulate each cell at will, to see what effect that has on the rest of the circuit.做完记录后,他们还想要能自由操纵每个神经细胞的第二套工具,以便找出这样的操作对细胞周围有何影响;Finally, to handle the unprecedented amounts of data that the first and second steps will generate, they would like a new set of computing hardware and software.最后,为了处理前面两个步骤所产生的空前的海量数据,他们还想要一套新的计算机软硬件。A modest proposal, then.如此看来这提案还不算过分嘛,And one which is inducing polite scepticism from many neuroscientists who are not part of the charmed circle, and who fear their subject is about to be sacrificed to a juggernaut.但它却也引来了许多此小圈子外的神经学家客气的猜疑,他们担心实验被试会成为这一计划的牺牲品。Such scepticism is reasonable.这种怀疑是合乎情理的。The third part of the project, the computer side, should be doable.该计划的计算机部分是可行的,不论如何,这只不过是提高计算机的原有水平而已。That is just a question of pushing harder in a direction things are, in any case, going.但是前面两部分你要怎么完成呢?谁都不知道。How you would do the first two, though, is anybodys guess—and Dr Alivisatos and his colleagues are pretty sketchy about the details.而且阿里维萨多和其同事对相关细节也说得相当笼统。Thinking big, thinking small高瞻远瞩也要低头看路What ideas there are draw heavily on the nascent field of nanotechnology.现在能想到的办法主要就是利用纳米技术这一新领域,This is Dr Alivisatoss particular province, and also that of the Kavli Foundation, which exists to advance fundamental research in the fields of astrophysics, nanoscience, neuroscience and theoretical physics.这是阿里维萨多的专攻领域,也是美国科威利基金会专门持的领域。该基金会的宗旨是推动天体物理学、纳米技术、神经学和理论物理学等领域的基础研究,A brain map would push two of those buttons, which accounts for the fact that five of the manifestos authors work for institutes sponsored by this foundation.一个大脑地图计划就会涉及到里面的两个领域,这也解释了《科学》杂志上的声明人中有五个在该基金赞助的机构工作这一事实。But any successes that nanotechnology has enjoyed so far have been small beer compared with the devices that would be needed to interrogate nerve cells, record the results and transmit them back to base, let alone tell those nerve cells what to do.但是,和审问神经细胞、记录审问结果并将审问结果传回大本营所需要的设备相比,目前纳米技术领域所取得一切成果都是些小把戏,就更别指望能用它来控制神经细胞的行为了。The protagonists would, they say, build up slowly, using humbler creatures than human beings as experimental subjects to start with.该计划的发起人说,他们会慢慢推进,首先使用比人类低级的生物作为实验对象。This was the approach taken by the Human Genome Project, which began with bacteria and yeast, progressed to worms, flies and mice, and only then tackled people.人类基因组工程当初便是采取的这一途径:一开始是细菌和酵母,再升级到蠕虫、苍蝇和老鼠,最后才是人类。But the analogy is not quite a fair one.但拿它做类比还不大合适,When the genome project started,genomicists aly had a basic understanding of how to go about it.因为在基因组工程启动时,遗传学家对该如何进行已经有了一个基本理解,That understanding was vastly refined and improved by the application of several billion dollars.这一理解在花费了数十亿美元后得到了大大的提炼和改善。But it was there from the beginning.但人家一开始就有理解啊。Going from existing methods of recording and manipulating cell activity, which rely on large electrodes, often connected to the outside world by physical wires, to the massively parallel, wireless system envisaged by Dr Alivisatos, is a different proposition.记录和操纵细胞活动的现有技术要依靠一些很大的电极,从这些技术跨越到阿里维萨多士所设想的无线平行体系,相对基因组计划而已,则是一个不同的命题。It may be possible. But it requires a leap of faith.这也许是可能的,但要让人相信则需要信心的大飞跃。The next few weeks will reveal whether that faith is shared by a cash-strapped president.囊中羞涩的总统是否也有这种信心呢?将会在后面的几周内揭晓。 /201312/267747湖北宜昌阳痿早泄价格Science and technology科学技术Drug research药物研究Toxic medicine毒类药品Snake venom is being used to cure, rather than kill蛇毒用于治病,不是杀伤THERE are no poisons, only poisonous doses.Thus did Paracelsus, the greatest of the alchemists, encapsulate an important piece of medical wisdom.曾经最伟大的炼金术士帕拉塞尔苏斯创立的一条重要的医学名言如是说:没有毒药,只有毒剂。In fact, that is only half the story,然而,这只说对了一半。for many materials which are toxic at high doses, when used sparingly and directed at specific targets, are not merely harmless, but actually beneficial.很多物质量大了以后就有毒性了。当计量后专用时,不仅无害,而且有益。Plant poisons, from digitalis to curare, are routinely employed as drugs.一些植物的汁液,都可用作常规药物。And now it is the turn of animal toxins, as researchers examine venoms secreted by snakes and lizards, to see if they, too, might be turned into treatments.而现在研究人员转向研究动物的毒液―蛇和蜥蜴分泌的毒汁,检验它们是否可用来治病。Snake venom, collected from farmed reptiles, has been used to make antisera for snake bites for decades by injecting it into mammals such as sheep and horses, and collecting the antibodies thus generated.圈养的蛇可收集蛇毒。几十年来,人们一直用蛇毒制作抗血清4治疗毒蛇咬伤,还把它注射到绵羊和马这样哺乳动物体内,收取抗体。Making drugs from the venom itself, however, is a fairly new idea.虽然蛇毒制药是一个全新的概念,But that is what Stefan Hailey of the University of Delaware and his colleagues hope to do.但特拉华州大学的史蒂芬?哈利和他们同事希望如此。In a paper published recently by Toxicon, they report how a protein called eristostatin, which can be extracted from the venom of the Asian sand viper, helps peoples immune systems fight malignant melanoma.最近,他们发表了一篇名为《毒素》的论文,介绍了从亚洲沙蝰的毒液中可以提取蛇毒蛋白质,这种蛋白质可激发人类免疫系统对抗恶性肿瘤。Previous studies have shown that eristostatin stops melanoma cells colonising the liver and lungs in mice.先前的研究发现蛇毒蛋白质能阻止黑色瘤细胞5在肝脏和肺的扩散。Dr Hailey is trying to work out how this happens.哈利正解密这一过程。Eristostatins day job is to stop victims blood clotting and thus plugging up damaged blood vessels after a bite.蛇毒蛋白质的功效是人被蛇咬伤后防止血液凝固堵塞血管。By increasing blood loss, it weakens victims.受伤者失血过多,逐渐虚弱。The molecule does this by glomming onto cellular fragments called platelets that are crucial to the process of clotting, thus disabling them.抗凝分子能抑制血小板这种在血凝过程中起关键作用的细胞碎片,使其失效。Dr Hailey hopes to make use of this tendency to encourage the immune system to attack melanoma cells.哈利希望利用这种性质趋向激发免疫系统对抗黑色瘤细胞。His idea requires eristostatin to be as attracted to cancer cells as it is to platelets.他的理论需要蛇毒蛋白像抑制血小板那样吸引癌细胞。Two observations suggest it could be.两项研究结果实了其可能性。One is that eristostatin has a particular affinity for melanoma cells, which presumably have a protein on their surfaces that is similar to the one which attracts eristostatin to platelets.一是蛇毒蛋白与黑素瘤细胞有一定的亲和性,黑素瘤细胞表面可能有一种蛋白质,类似于让蛇毒蛋白吸附血小板的蛋白。The other observation is that when eristostatin is attached to a cells surface it attracts the attention of T-lymphocytes.另一项是蛇毒蛋白附于细胞表面时,可吸引T形淋巴细胞6。These are immune-system cells whose job is to kill other body cells that have been infected with viruses, or which have turned cancerous.这些免疫系统细胞能吞噬被细菌感染的细胞或是癌化细胞。If melanoma cells could, in this way, be made especially attractive to T-lymphocytes, that might clear away the tumour completely.假如能让黑素瘤细胞像这样吸引T形淋巴细胞,那么就可能完全消除肿瘤。Dr Hailey and his colleagues used a technique called atomic-force microscopy to study the interactions between melanoma cancer cells and eristostatin.哈利和其同事用原子力显微镜7技术研究黑素次瘤癌细胞与蛇毒蛋白的相互作用。This technique allows the force required to pull the two apart to be measured precisely, to see whether there is a genuine attraction—which he found that there is.这种技术可以调节原子力把两者分开进行精确测量,看看是否真的存在吸引―经他实是存在的。If eristostatin does prove an effective means to treat cancer, it will join a growing stable of medicines derived from reptile toxins.假如蛇毒蛋白真能有效地治疗癌症,就会把它归到不断扩大的蛇毒提取药类里。Tirofiban, for instance, is a modified version of another anticoagulant—in this case from the venom of the African saw-scaled viper.例如,欣维宁是从锯鳞8的毒液中提取的,是改良了的抗凝剂。It is given to people with angina, and also to those who have had heart attacks.欣维宁针对心绞痛患者以及心脏病患者。依泰德森是人工的唾液素4。Exenatide is the synthetic form of a hormone called exendin-4 that occurs naturally in the saliva of the Gila monster, a venomous North American lizard.自然状态下,存在于北美一种毒蜥―希拉毒蜥的唾液中。It works as a treatment for type-2 diabetes because it increases insulin production in those whose blood-sugar levels are high.唾液素4可用于治疗2型糖尿病10,因为它能增高高血糖患者体内的胰岛素含量。And captopril, a blood-vessel-relaxing agent widely used to treat hypertension, is based on teprotide, from Brazilian arrowhead vipers, which helps the other toxins in the venom circulate quickly, and thus reach their targets rapidly.卡托普利11―血管放松剂,广泛用于治疗高血压。它由替普罗肽组成,从巴西箭头毒蛇12提取,能加速毒液中毒素循环,迅速到达患处。The year of the snake蛇年There are other venom-based drugs in the pipeline, too.还有其它蛇毒提取药物在研发。Crotoxin, a protein from the South American rattlesnake, though not yet approved for use, may one day be employed to treat cancers.响尾蛇蛋白是从南美响尾蛇中提取的一种蛋白质,虽然还没有实临床效果,但有一天会用来治疗癌症。Crotoxin seems particularly attracted to cancer cells.响尾蛇蛋白表面看来特别能吸引癌细胞。One portion of the molecule recognises a protein on the cells membrane, and links to it.响尾蛇蛋白分子的一部分能识别细胞膜,并依附其上。The other portion damages the membrane, triggering a mechanism called apoptosis which causes the cell to kill itself.另一部分能破坏细胞膜,产生一种让细胞死亡13的机制。Celtic Biotech, based in Dublin, is running a series of tests using this molecule on cancer patients at the Georges Pompidou European Hospital in Paris.位于都柏林的凯尔特生物技术人员正进行一系列的实验,用这种分子来治疗巴黎皮蓬杜欧洲医院的癌症患者。This year, Celtic plans to try it on people with several different sorts of cancer, since the firms researchers believe it should be effective on all solid tumours.今年他们计划对患有不同种癌症的患者进行治疗,因为公司的研究人员相信治疗固体肿瘤很有效果。If those trials are successful, though, they then plan to concentrate on lung cancer, the largest market.假如成功,他们就会专攻肺癌的治疗。Perhaps the most astonishing toxin-derived drug of all, however, is hannalgesin, which is made from king-cobra venom.这是从眼镜蛇王毒素中提取,可能是蛇毒提取药中最疗效最神奇的。Kini Manjunatha of the National University of Singapore is developing this substance as a pain-relieving agent.新加坡国大的齐尼教授正把这种物质研发成镇痛剂。He claims it is between 20 and 200 times more effective than morphine.他说作用是吗啡的20到200 多倍不等。Moreover, unlike morphine, which is usually injected, hannalgesin can be taken by mouth.再者,Hannalgesin不像吗啡通过注射,可口。He is planning to run the first clinical trials at the end of 2013 or in early 2014.他计划于2013年底或2014年初进行首次临床试验。Venom, then, is proving to be a trove of useful molecules.经实毒素就是有用的分子的集合。At a time when drug companies are struggling to develop new products,让制药公司通过自然选择对原料进行验,研发新药。a novel source of raw materials that have been road-tested by natural selection, and merely need to be subverted from their original purposes rather than created afresh, must be welcome.这个新方法肯定受欢迎,因为不需要创新,而只是转换了药性。It is not turning base metals into gold, as Paracelsus and his kind once attempted.这个过程并不是像帕拉塞尔苏斯这样的术士们把贱金属转换成黄金,But as a transformation of matter, it is surely a far more valuable trick.但从物质转换的角度来讲,一定是价值连成。 /201310/261923湖北宜昌有治疗前列腺炎吗

宜昌男健医院生殖科周末上班吗湖北宜昌人民中妇幼保健医院阳痿早泄价格宜昌那家男科医院好It’s unlike any other creature that has walked the planet. 它和这个星球上其他的生物都不相同。T-Rex is different. Something about Tyrannosaurs and Tyrannosaurus Rex itself is different than other predatory dinosaurs. “雷克斯霸王龙独具一格。霸王龙以及雷克斯霸王龙和其他的掠食性恐龙是不同的。”But for such a celebrated killer able to take on the toughest creatures of the Cretaceous, some things just don’t add up. It’s slow. With a top speed not much more than 25 kilometers per hour, a T-Rex couldn’t even outrun a fit human. It’s also unwieldy, requiring a full two seconds to make a 45-degree turn. 但是,对于这样一种能够击败白垩纪最难对付生物的著名杀手来说,有些东西也不如人意。那就是它的速度。雷克斯霸王龙的最高速度超不过每小时25公里,甚至没有一个健康的人类速度快。它同样十分笨拙,转一个45度的圈就需要整整两秒钟。If a T-Rex were to fall over while chasing a prey item, it might seriously wound itself. And its hands, with only two fingers are completely useless for gripping prey. 如果雷克斯霸王龙在追击猎物时摔倒,那它将可能受到严重的伤害。而雷克斯霸王龙的前肢仅仅两根手指,这对于抓住猎物来说完全没有作用。After its giant size and its huge teeth, the thing we most notice about T-Rex are its dinky, little arms, these tiny, little arms that can’t even reach its mouth. “研究过雷克斯霸王龙巨大的体型和牙齿后,我们接下来最容易注意到的就是雷克斯霸王龙小小的前肢,这些极小的前肢甚至不能触碰到它们自己的嘴部。”The giant T-Rex is a baffling creature. There has to be more to this killer. How did this giant mouth on legs become the ded butcher of the Cretaceous? Was its raw power, its shark-like jaws, or something else entirely?雷克斯霸王龙体型巨大并充满谜团。它身上一定还有更多的秘密。它长在腿部的大嘴又怎样成为了白垩纪最恐怖的“屠夫”呢?是因为它的强壮有力?它鲨鱼般的大口?还是完全因为其他的原因?Fossils of Tyrannosaurus Rex have been unearthed in the U.S., Canada, and even Asia. For scientists, these discoveries point to one conclusion—this carnivore has little to fear, even from the most well-armed herbivore of the Cretaceous, Triceratops. But to bring down an animal this tough takes more than just brawn, muscle, and teeth. It requires planning and strategy. 雷克斯霸王龙的化石曾在美国,加拿大,甚至亚洲被发掘出。对于科学家们来说,这些发现都引向一个结论——这种食肉恐龙基本上无所畏惧,对于白垩纪防御力最强的食草恐龙三角龙也同样如此。但是,想要击倒像三角龙防御力这样强的动物,仅仅依靠发达的肌肉,牙齿还远远不够。同样需要的是计划以及战略。The T-Rex is highly intelligent. Its cerebrum is one of the largest of the prehistoric world. It has the ability to process sophisticated sensory information.雷克斯霸王龙智商极高。它的大脑是史前世界最大的动物大脑之一。它能够处理复杂的传感信息。英文文本来自普特英语,译文属未经许可不得转载。201402/276410宜昌包皮过长手术费多少钱

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