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郴州治疗早泄费用郴州市人民医院男科咨询Science and technology科学技术The nature of humanity人类本质Whats a man?什么是人类Studies of brain genetics are starting to reveal what makes humans human大脑遗传研究,为你解开人之所以为人的奥秘THE problem with understanding human uniqueness is precisely that it is unique.研究人类独特性的难题在于这个独特性本身就很独特。Though the proper study of mankind may be man, that study will yield little if there is no reference point to compare man with.虽然人类研究的主体对象是人,但是如果没有比照对象的参与,研究很难有所突破。That, at least, is the philosophy of Svante Paabo of the Max Planck Institute for Evolutionary Anthropology, in Leipzig.至少,来自莱比锡马克斯普朗克进化人类研究所的斯万特帕珀是这样认为的。Dr Paabo, whose work on fossil DNA was the inspiration for Jurassic Park,帕珀士主要研究化石的DNA,正是受到《侏罗纪公园》启发,has since become interested in human evolution.他对人类进化史产生了浓厚的兴趣。To this end, he and his colleagues have sequenced the DNA of both Neanderthal man and an Asian species of prehistoric human,为了一探究竟,他和同事将穴居人和史前亚洲人种,the Denisovians, which Dr Paabos own work identified.帕珀士将其定义为丹尼索维亚人的DNA按序排列。Now he has turned his attentions to modern Homo sapiens.现在他又将注意力转移到了现代智人身上。In collaboration with a team from the Chinese Academy of Sciences,帕珀士和同事菲利普卡托维奇与中国科学院的科学家们相互合作,Dr Paabo and his colleague Philipp Khaitovich have compared genetic activity over the course of a lifetime in the brains of humans, chimpanzees and rhesus monkeys.将人类,猩猩,以及恒河猴有生之年的大脑遗传活动进行了比对。They have then matched what they found with what is known of Neanderthals,随后,他们将研究成果同穴居人研究成果相配对,and think they have thus discovered at least part of the genetic difference between Homo sapiens and the others that creates human uniqueness.并发现了智人和其他物种的差异,至少是部分差异。正是这些差异造就了人类独一无二的特性。Dr Paabo and his colleagues focused their examination,帕珀士和同事十分重视实验,just published in Genome Research, on two parts of the brain.他们只在《基因研究》杂志上刊登了大脑两个区域的研究成果。One was the dorsolateral prefrontal cortex,区域一是大脑背外侧前额皮层,which is the seat of abstract reasoning and social behaviour,things that humans are particularly good at.主管抽象思考和社交行为一类人类尤为擅长的活动。The other was the lateral cerebellar cortex, which is more to do with manual abilities.区域二是同动手能力联系密切的外侧小脑皮层。They extracted cells, post mortem, from people, chimps and monkeys of many ages, and looked at which genes had been active in these cells when the owners were alive.他们从不同年龄层的人类,黑猩猩以及猴子尸体上提取相关细胞,然后观察哪些基因在宿主存活时表现活跃。The vortex of the cortex皮层漩涡They did this by examining the RNA in the cells.他们通过检验细胞中的RNA来进行观察。RNA molecules are single-stranded copies of the double-helical DNA genes in the cell nucleus.RNA分子是细胞核内的双螺旋DNA基因的单链拷贝。Their job is to carry instructions from the genes to a cells protein-making machinery.RNA的工作是把基因的指令带到细胞的蛋白质形成机构内。Most primate genes have now been identified,现在大部分灵长类动物的基因都已被识别出来,so it is possible to make chips covered with complementary strands to the RNA messengers,所以人类可以制作一张芯片,在上面布满结构互补的单链RNA,to which these messengers will uniquely stick, and which thus act as probes for particular messenger molecules.因为信使RNA会与其紧密结合,所以可以专门用该芯片来搜寻携带遗传信息的分子。Using such chips, Dr Khaitovich and Dr Paabo were able to find out when, during the course of life, particular genes were active,卡托维奇士和帕珀士计算出了不同年龄段的不同个体的大脑的特定区域内每个基因细胞里的RNA数量,by working out how much RNA from each gene cells from particular parts of the brains of individuals of different ages contained.并利用该芯片,找出了一生中表现活跃的几个特定基因。Their results fell into six categories.以下是他们的六大发现。First, they found some genes whose expression patterns over a lifetime were uniquely human and others that were uniquely chimpanzee.发现一,有的基因的表达方式为人类特有,有的为猩猩特有,Second, they discovered that there were more uniquely human expression patterns than uniquely chimp ones.发现二,人类特有的基因表达要多于猩猩。Third, unique human expression patterns were more common in the prefrontal cortex than in the cerebellum.发现三,人类特有的基因表达多出现与前额叶皮层,而不是小脑。Fourth, though these uniquely expressed genes were most active in the young of all species,发现四,尽管这些物种特有的表达基因最活跃的时期都在青年期,their period of activity was several years longer in humans than in the others.但是人类基因的活跃期较长,能持续数年。Fifth, the activities of a lot of the uniquely active genes seemed to be correlated:发现五,许多活跃基因所进行的活动是相互联系的:the researchers identified seven groups of genes which each seemed to be working as a module.研究者发现了七组基因,似乎每一组都是独立的单元。And sixth, these modular genes seem to be involved in the crucial job of linking nerve cells together through junctions called synapses.发现六:这些单位基因组似乎在担子不轻,它们要经过各个枢纽将神经细胞连接到一起,这些枢纽名叫突触。To summarise, human beings have suites of genes that probably cause their brains to be plastic,总之,人类特有的一套套基因让大脑具备了可塑性,and thus receptive to change far longer than is true for chimps or monkeys.而且应变能力的维持时间要远远长于猩猩和猴子的大脑。Moreover, Dr Khaitovich was able to work out how the expression of these modules of genes was co-ordinated,另外,卡托维奇士通过观察控制基因单位的开关,by looking at the switches, known as transcription factors, that turn them on and off.也就是众所周知的转录因子,已经能够解答各个基因单位的表达是如何协调的问题。Indeed, by comparing modern genomes with their discoveries about Neanderthals Dr Paabos group has found that the regulatory process for one of the modules came into existence after the modern human and Neanderthal lines separated from one another, about 300,000 years ago.的确,通过比对现代人基因组和穴居人研究成果,帕珀士一行人已经发现了某组基因的调节过程,早在30万年前,当现代人类从穴居人家系中分离出来时,该组基因就已存在。Unfortunately, it is not possible to look at the expression pattern of genes in Neanderthals, and it probably never will be.然而不幸的是,现在已经无法观察穴居人的基因表达方式,而且可能再也看不到了。But it might be possible, as knowledge advances, to reconstruct part of it from a better understanding of that extinct speciess DNA.但是随着知识的积累,科学倒是家可以凭借对已消亡的物种的DNA更深入的了解,将穴居人的部分基因重现出来。Pleistocene Park, anybody?拍一部《更新世公园》,怎么样? /201403/280499郴州治疗早泄最好的医院是哪个 For England to believe that Henry was the rightful king,为了让英格兰相信亨利是合法的国王,he would need to behave like one, and that is exactly what he did.他需要让自己像个国王的样子,而这正是他着手做的事情。Parliament has made of Westminster for over 800 years.威斯敏斯特议会已经有800多年的历史。The official records of its debates, meetings, and acts stretch back to the Middle Ages.官方记录的辩论,会议,和法案甚至可以追溯到中世纪。In early November 1485, Henry VIIs first parliament met.1485年11月上旬,亨利七世的第一次议会召开。He would use it to tackle the inconvenient truth of Richard IIIs reign until rework recent events to suit himself.他会以此来处理忽视的理查德三世的统治真相直到最近的事适合自己。And heres the written proof, the parliamentary record which shows how he did just that.而这里的书面据显示,他的议会纪录正是这样做的。In this record, Richard III is the usurper, Henry VII is the rightful king putting the record straight.在这份记录当中,理查德三世是篡位者,亨利七世是合法的国王将直接记录下来。 201311/263039Most of us have had the same experience.大多数人都有过这样的经历,We see a big, red tomato in the grocery store, take it home for our salad, and find out that it tastes like cardboard.从商店里挑选出又大又红的番茄回去做沙拉,然后一尝,味同嚼蜡。You might think that the tomato is sub-par because its been picked before it ripened, or shipped across the country.你可能认为买回的番茄味道不好是因为它没有成熟就被摘下,或者是运输过久的原因。Those things can be true, but scientists have found another reason why modern tomatoes have little or no taste.这的确是一部分原因,然而科学家们发现现今的番茄不好吃还有其它原因,Its in their genes.那就是它们的基因问题。The problem began with old fashioned or heirloom tomatoes.这个问题要追溯到从前的天然番茄,They didnt ripen consistently.它们并不总能完全长熟,Someareas would be red, while other areas, usually near the stem, would be white or green.番茄的有些部分是红的,而其它地方,尤其是靠近茎蒂的地方,往往是白色或绿色的。About seventy years ago, tomato breeders accidentally discovered a variety that turned red uniformly.大约70年以前,番茄种植者们偶然间发现一种全红的番茄品种,Consumers liked the way the tomatoes looked, and companies that made ketchup and tomato sauce could make better looking products.不仅消费者们喜欢这种模样的番茄,番茄酱制造公司也能生产出卖相更好的产品,The trouble was, red did not equal tasty.然而问题也出现了,看起来好看并不代表它的口感好。While experimenting with weed genes that turned tomatoes dark green, geneticists accidentally discovered one of the reasons why todays tomatoes lack taste.基因学家在对使番茄呈墨绿色的基因进行实验的过程中,意外发现了现今西红柿乏味的另外一大原因。Modern tomatoes are light green before they turn uniformly red.现在的西红柿在全部变红之前是呈浅绿色的,Surprisingly, the mutation that gives tomatoes uniform red color actually disables some of the ripening genes.令人惊奇的是,让番茄变红的变异却恰恰抑制了成熟基因的作用。Those genes allow the fruit to make its own sugar which makes the tomato sweeter.而成熟基因可以使水果产生糖分,从而使番茄变甜,The genes also increase the amount of carotenoid pigments,which give tomatoes the red color.同时产生更多的类胡萝卜素,使番茄变红。When researchers turned the ripening genes back on, their experimental tomatoes had twenty percent more sugar and up to thirty percent more carotenoids.当研究者们尝试着将成熟基因恢复到原有数量后,他们的实验番茄中所含的糖分增加了20%,类胡萝卜素提高了30%。Unfortunately, regulations prohibited researchers from tasting their experimental fruits, but youcan try eating heirloom tomatoes.遗憾的是,由于法规的原因,研究者们无法品尝自己的实验番茄,不过你们可以试着尝尝那些纯天然的番茄。They arent as pretty looking, but are tastier.它们不中看,但是很好吃。 /201403/279415郴州中医男科医院不孕不育多少钱

郴州市中心医院看泌尿科怎么样郴州男科泌尿医院哪家好 Science and technology科学技术Prospecting for oil石油勘探Grains of truth千虑一得之法Putting rocks in medical scanners may help the search for oil and gas采用医学扫描仪对岩石样本扫描,可帮助寻找石油和天然气STRIKING oil is one thing.开采石油是一回事。Getting it out of the ground in economic quantities is quite another.然而从经济角度考虑,能从地下开采出多少石油又完全是另一回事。Doing so depends on understanding the granular structure of the rock it is trapped in,要做到这点,人们需要对某些岩石的颗粒结构有所了解,而这些岩石是有石油困于其中的。分and analysing that is a tedious business of placing countless samples in pressure vessels to assess their capacity to hold hydrocarbons and to estimate the flow rate of those hydrocarbons through them.析岩石颗粒结构是极其枯燥乏味的事情,研究人员需要将无数个样本放置在压力容器内以评估它们含纳碳氢化合物的能力并估計其中蕴藏的碳氢化合物的产量。This can take years.这可能需要花费数年的时间。Help, though, is at hand.然而可施之法即在眼前。Computerised tomography scanning has been used in medicine for several decades.计算机X线断层照相扫描术在医学领域应用已有几十年时间。Now it is being applied to geology.目前它正被应用于地质学。In alliance with electron microscopy, the geological use of CT scanning has given birth to a new field, digital rock physics.在与电子显微镜配合使用下,CT扫描术在地质上的应用育了一个新的领域—数字岩石物理。The fields proponents believe it will let oil companies decide far more quickly than they could in the past which strikes are worth exploiting, and which should be abandoned.该领域的倡导者认为,该项技术能使石油公司较之以往更加快速地判断哪些石油矿值得开发,哪些应该放弃。One of those proponents is Amos Nur, chief technology officer at, a company based in Houston, Texas.科技公司Ingrain总部设在得克萨斯州休斯敦,其首席技术官阿莫斯?努尔是该技术倡导者之一。His firm is one of three independent digital-rock-physics laboratories in the world.他所在公司是全球三家独立数字岩石物理实验室之一。According to Dr Nur, the new technology is capable of creating three-dimensional pictures of a samples structure with a resolution of 50 nanometres.努尔士表示,这项新技术能为岩石样本结构创建分辨率为50纳米的三维立体照片。That is enough to work out how oil and gas trapped in the pores between the grains of such a rock might be expected to behave.这足够预测出困在岩石颗粒细孔间的石油和天然气的表現方式。Most of the samples analysed by Ingrain start as cylindrical cores brought up from deep below the Earths surface by drills.开始分析的大部分样本都来自于地下深层钻探得到的圆柱形岩石核。A typical core is several metres long, so it is first subject to a rough and y CT scan using a standard medical scanner.典型的岩石核有几米长,因此首先要采用标准医学扫描仪对其进行粗略的CT扫描。The scanner is fitted with calibration rods made of a proprietary material whose properties provide reference points for the creation of an image.该扫描仪安装了许多由专利材料制成的调校棒,这种材料有为图像创建提供参考点的属性。This initial scan yields a picture that has a resolution of about 500 microns.初始扫描会得到一张分辨率为500微米的图片。That done, sections of the core 2-3cm long, whose porosity is of particular interest, are subject to further study.这些完成之后,将一些长度在2至3厘米间,其孔隙度有特殊研究价值的小岩石块做进一步研究。This involves scanning them in a special micro-CT machine, of a sort developed originally to look at computer chips.这包括将岩石核样本放入一台特殊的微CT机进行扫描—微CT机原是为了观察电脑芯片而研制的。The sample is placed on a turntable and rotated inside this microscanner.将小岩石核样本放置在微扫描器内部的转盘上并使其旋转,The result is a 3D image with a resolution of 40 microns.结果得到一个分辨率为40微米的三维图像。This allows sections requiring further study to be identified.这就使得需做进一步研究的小岩石块能够被标识。These sections are dissected, using a laser, into slices a millimetre or less thick, and then scanned again, either with the micro-CT or with a scanning electron microscope.采用激光将这些小岩石块切分成一毫米或不太厚的薄片,然后用微CT机或电子显微扫描镜对其再次扫描。That brings the resolution to half a micron, or 500 nanometres.这样便将图象分辨率提高到了0.5微米或500纳米。Finally, the image is cleaned up by a computer program and the 50-nanometre-resolution picture emerges.最后,将该图像进行计算机降噪去斑处理,得到一张50纳米分辨率的图片。This image, which shows the porosity of the rock, and the channels between the pores,然后将能够显示岩石孔隙度和岩石内部毛孔间通道的图像用计算机分析,is then subject to a computer analysis that reveals how easily hydrocarbons will flow through it under pressure—and thus the likely productivity of a well dug at that site.结果会显示在有压力情况下碳氢化合物在岩石块内部流动的容易程度—从而得知样品来源之处那口钻探井的可能产量。Whether digital rock physics will actually replace traditional methods is unclear.“数字岩石物理”技术是否能够取代传统方法,目前尚无定论。Sceptics, such as Anthony Kovscek of Stanford University, think the claims being made for it are exaggerated.许多人对此持怀疑态度,斯坦福大学的Anthony Kovscek就是其中之一,他认为该技术的声明有夸大成分。Though analysis of a rocks structure in this way will, in his opinion, be able to tell you that a strike is unlikely to yield a commercial return,在他看来,尽管采用这种方法得出的岩石结构分析结果能够告知人们哪个钻探点不可能产生商业回报,the reverse is not true.但其反面结论却未必正确。He does not believe that the technique can predict flow rates,他不相信这种技术能预测石油的流量,even from rock that contains a lot of hydrocarbons—and flow rates are crucial to an oil fields economics.即使对于含有大量碳氢化合物的岩石也无法预测—石油流量是油田经济中至关重要的指标。The new discipline of digital rock physics has, nevertheless, attracted considerable attention within the industry.但是“数字岩石物理”这门新学科在行业内引起了相当大的关注。Smaller oil companies are using the facilities of Ingrain, Numerical Rocks and Digitalcore.小型石油公司正在使用Ingrain、Numerical Rocks和Digitalcore的设备。Larger ones, such as BP, Chevron and Shell, are setting up their own digital-rock-physics laboratories.而大型石油公司—如BP、雪佛龙和壳牌正在创建自己的数字岩石物理实验室。As the supply of crude oil dwindles and the price thus rises, anything that makes the process of prospecting new wells cheaper is to be welcomed. This new technique may be such a thing.当原油供应下降并导致价格上升之时,任何能使新井勘探成本更低的技术都将受到欢迎。“数字岩石物理”可能就是满足此要求的新技术。 /201305/239868郴州人民医院男科

郴州市第四人民医院泌尿外科 Science and technology科学技术Solar energy太阳能Flower power花朵的能量In matters of clever design, nature has often got there first若论巧夺天工,自然常常更胜一筹A virtuous spiral上面的螺纹看似简单,实际有效SOLAR-POWER stations take up a lot of room.太阳能发电站占地面积巨大,They need either vast arrays of photovoltaic panels, which convert sunlight directly into electricity, or of mirrors,站内大部分的空间被光伏太阳能板或和定向反射镜所占据。前者能将光能直接转换为电能;后者会将太阳热折射到锅炉,which direct it towards a boiler, in order to raise steam and drive a generator.利用锅炉将水加热成蒸汽,驱动发电机组工作,达到热能转化为电能的目的。The space these arrays occupy could often be used for other purposes.这些整齐排列的面板和镜身所占的区域通常能用于其它用途。Two researchers from the Massachusetts Institute of Technology have now devised a better and more compact way of laying out arrays of mirrors.麻省理工学院的两位研究员就找出了更好的方法布置定向反射镜排列,不仅能节约出更多的空间,还能提高发电效率。Slightly to their chagrin, however, and somehow appropriately,然而,有点儿让他们懊恼的是,they found when they had done the calculations that sunflowers had got there first.他们计算出的和向日葵花盘型花序上所排列的,大致相同。Alexander Mitsos and Corey Noone started with the observation that existing concentrated solar-power plants,Alexander Mitsos和Corey Noone这两位研究员先从观察运行中的集中型太阳能发电厂入手。as those which drive boilers are known, usually have their mirrors arranged in a way that resembles the seating in a cinema.如大家所知,这些发电厂用太阳能驱动锅炉做功产生热量。通常定向反射镜的安排布置与电影院座椅位置如出一辙。The mirrors are placed in concentric semicircles facing a tower, on top of which the boiler and the turbine sit.高塔处于荧屏所在的中心位置,所有的定向反射镜则以高塔为圆心,呈半圆形分布。That arrangement, however, sometimes results in the mirrors shading each other as the suns position in the sky changes,随着一天中太阳在天空中位置的变换,镜身间会出现相互遮挡的问题。even though the mirrors are usually attached to robotic arms that track the sun as it moves.即使厂家通常会在镜身后部安装能随太阳位置变换而相应变换的机械手臂,但这一问题还是无法解决。According to their report in Solar Energy, Dr Mitsos and Mr Noone found that they could do better.据他们在《太阳能》杂志上发表的文章称,两位研究员认为能有方法解决这一难题。They divided each of the mirrors in a real power plant, PS10, in southern Spain into about 100 pieces.在一家位于西班牙南部的发电站,PS10中,他们把每一片定向反射镜的平面面积分为差不多100块。They then plugged each of those pieces into a computer model that calculated all of the energy losses然后将每一片镜身上的这100多块面积里产生的吸热数据接入电脑,通过电脑程序计算出能量损失总和。by noting points where mirrors were not optimally oriented to the sun and places where they hindered one another by blocking incoming or reflected rays.这包括镜身没能直对太阳造成的损失,以及镜身位置因相互遮挡使折射光线受阻或反射到锅炉的光线受阻时造成的损失。It then rejigged them into a better arrangement.然后再根据数据重新对镜身进行排列组合。Fermats conjecture费马螺线魔力Previous efforts have been directed mainly at stopping the mirrors shading each other, which tends to mean sping them out.在此之前,人们做出了种种努力,但总是在镜身相互遮挡这一问题上束手无策。而对此常会采用的是展开布局,增加排列面积来避免这种情况出现。Dr Mitsos and Mr Noone also wanted to save space.而两位研究员还想节省面积。In trying to do so they stumbled on an unusual arrangement that had the desired effect.为此绞尽脑汁之际,他们无意中发现有一种非常规的排列布局有很好的效果。When they showed this layout to a third researcher, Manuel Torrilhon of Aachen University in Germany,他们将这种布局安排展示给另一位研究者,德国亚琛工业大学的Manuel Torrilhon。he recognised the spiral patterns within it, and this prompted the trio to test a design specifically modelled on nature.后者认为这种设计中有螺线存在,这促使三位研究者以向日葵花盘型花序为蓝本仔细测试设计。That design was a pattern known as a Fermat spiral, in which each element is set at a constant angle of 137° to the previous one.他们采用的设计即费马螺线。即每一个圆在之前一个圆旋转角度为137度时,折线回旋螺线。It is most familiar as the arrangement of the florets that make up a sunflower head.这一排列布置与向日葵花的盘型花序纹路如出一辙。When the three researchers programmed their model to arrange PS10s mirrors in front of the tower in a segment from such a spiral,三位研究者按照计划安排PS10发电厂的镜身位置,在高塔前,将定向反射镜呈部分费马螺线状布局。they both improved the efficiency of the collection process and saved space.结果显示在吸收太阳热量的过程中,效率得以提高,占地面积减少。The improvement in efficiency was, admittedly, quite small,诚然,效率提高非常有限,but the space saving was significant—almost 16%.而空间节省面积却很高,减少近16%。If solar power is to make up much of the worlds electricity output in future, as supporters of alternative energy hope it will,如果太阳能如可替代能源持者所希望的一那样,在未来成为世界电力的重要来源,a lot of land will be needed for the power stations.那么太阳能发电站势必将需要占据更大的面积。Reducing that requirement by a sixth, as this discovery promises, would be a big gain.如果能像此次研究所发现的那样,有希望将定向反射镜所占地面积减少六分之一,那么这将是一个巨大的进步。It would also show that if you look hard enough, there really is nothing new under the sun.同样让我们认识到的是,地球上还有许多未知等待我们认真研究。 /201403/280877郴州市那里看男科最专业郴州第一人民医院南院治疗阳痿早泄



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