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同邪们周二的作业来咯,别掉队哦。
春节也过了,真的没得赖了。加油吧,早考完早超生。文章题目隐藏了。
Diamond to shine light on infections
[attachimg=624,410]114416[/attachimg] 【Time1】 The UK's national synchrotron facility - the Diamond Light Source near Oxford - is to become a world centre for studying the structure of viruses and bacteria that cause serious disease.
Diamond uses intense X-rays to reveal the molecular and atomic make-up of objects and materials.
It will now use this capability to image Containment Level 3 pathogens.
These are responsible for illnesses such as Aids, hepatitis and some types of flu.
Level 3 is one step down from the most dangerous types of infectious agent, such as Ebola, which can only be handled in the most secure government facilities.
"Viruses, as you know, are sort of tiny nanomachines and you can't see them in a normal microscope.
"But with the crystallography and X-ray techniques we use, we are able to get about 10,000 times the resolution of the normal light microscope," explained Dave Stuart, the life sciences director at Diamond and a professor of structural biology at Oxford University.
"This takes us from the regime of not being able to see them to being able to see individual atoms.
"And if we can look at 'live' viruses and get an atomic-level description of them, it opens up the possibility of using modern drug-design techniques to produce new pharmaceuticals."
Diamond has been working for some time to get its "Crystal Lab" ready for Level 3 work, and the Oxford researcher used the US conference to announce that the preparation was now complete.
Synchrotrons work by accelerating electrons in a giant magnetic ring to near light-speeds.
As the particles turn around the circle, they lose energy in the form of exceptionally intense X-rays. 【292】
【Time2】 This light is channelled down "beamlines" where it hits targets put in its path.
The way the X-rays scatter off the atoms in these targets reveals their arrangement. This allows scientists to glimpse the shape of virus and bacteria components and get some insight into how they function.
Diamond has already been studying pathogens at lower levels of containment.
A good recent example, says Prof Stuart, is the Human Enterovirus 71 (EV71) that causes hand-foot-and-mouth disease.
The infection is relatively common in infants and children, especially across the Asia-Pacific region, and is characterised by fever, painful sores in the mouth, and unpleasant blisters on the hands, feet and buttocks. There is currently no vaccine or anti-viral treatment available.
A joint UK and Chinese team working at Diamond solved the structure of EV71 last year.
This allowed the researchers to see a kind of breathing motion in the virus that it uses to initiate the infection process. Evident also was the small molecule it picks up from the body's cells to shift itself from one state to another. [attachimg=624,150]114417[/attachimg] The Crystal Lab uses robots
"That molecule must be lost to cause an infection, but now that we can see in atomic detail what that molecule looks like, we can try to design a synthetic version that will attach more strongly," Prof Stuart told BBC News.
"That would stop the breathing and stop the infection process."
The British synchrotron's new status makes it now one of only two such facilities in the world where Level 3 study is undertaken; the other being in the US.
This means it will be a major draw for scientists across the world.
Prof Stuart stressed the operations at Diamond would pose no risk to others working on the Harwell site or in the immediate Oxfordshire area.
The pathogens will be brought to the synchrotron in crystal form in double-sealed containers that are not opened during their time at the facility.
They are manipulated robotically inside the Light Source and, what is more, they are destroyed in the very act of shining X-rays on them. 【347】
Scientists Create Method to Personalize Chemotherapy Drug Selection
[attachimg=300,240]114418[/attachimg] 【Time3】 In laboratory studies, scientists at the Johns Hopkins Kimmel Cancer Center have developed a way to personalize chemotherapy drug selection for cancer patients by using cell lines created from their own tumors.
If the technique is successful in further studies, it could replace current laboratory tests to optimize drug selection that have proven technically challenging, of limited use, and slow, the researchers say.
Oncologists typically choose anticancer drugs based on the affected organs' location and/or the appearance and activity of cancer cells when viewed under a microscope. Some companies offer commercial tests on surgically removed tumors using a small number of anticancer drugs. But Anirban Maitra, MBBS, professor of pathology and oncology at the Johns Hopkins University School of Medicine, says the tissue samples used in such tests may have been injured by anesthetic drugs or shipping to a lab, compromising test results. By contrast, he says "our cell lines better and more accurately represent the tumors, and can be tested against any drug library in the world to see if the cancer is responsive."
The Johns Hopkins scientists developed their test-worthy cell lines by injecting human pancreatic and ovarian tumor cells into mice genetically engineered to favor tumor growth. Once tumors grew to one centimeter in diameter in the mice, the scientists transferred the tumors to culture flasks for additional studies and tests with anticancer drugs. 【227】
【Time4】 In one experiment, they successfully pinpointed the two anticancer drugs from among more than 3,000 that were the most effective in killing cells in one of the pancreatic cancer cell lines. A report on the success was published online Jan. 22 in the journal Clinical Cancer Research.
The new method was designed to overcome one of the central problems of growing human tumor cell lines in a laboratory dish -- namely the tendency of noncancerous cells in a tumor to overgrow cancerous ones, says James Eshleman, M.D., Ph.D., professor of pathology and oncology and associate director of the Molecular Diagnostics Laboratory at Johns Hopkins. As a consequence, it has not been possible to conventionally grow cell lines for some cancers. Still other cell lines, Eshleman says, don't reflect the full spectrum of disease.
To solve the problem of overcrowding by noncancerous cells, Maitra and Eshleman bred genetically engineered mice that replace the noncancerous cells with mouse cells that can be destroyed by chemicals, leaving pure human tumor cells for study.
"Our technique allows us to produce cell lines where they don't now exist, where more lines are needed, or where there is a particularly rare or biologically distinctive patient we want to study," says Eshleman.
In its proof of concept research, the Johns Hopkins team created three pancreatic ductal adenocarcinoma cell lines and one ovarian cancer cell line. They then tested one of the pancreatic cancer cell lines (called Panc502) against the Johns Hopkins Drug Library of 3,131 drugs, identifying tumor cells most responsive to the anticancer drugs digitoxin and nogalamycin. 【261】
【Time5】 For 30 days, they watched the effects in living mice of the two drugs and a control medicine on tumors grown from implanted cells derived from Panc502 and an additional pancreatic cell line, Panc410. They measured the size of tumors twice a week. Both drugs demonstrated more activity in reducing the tumor appearance and size in Panc502 than in Panc410, supporting the notion that the cell line technology may better predict sensitivity to the two drugs.
The investigators have given one type of their genetically engineered mice to The Jackson Laboratory in Bar Harbor, ME, a mouse genetics research facility, for breeding and distribution to other laboratories and are looking to partner with a company to distribute two other types. Study co-authors were Hirohiko Kamiyama, Sherri Rauenzahn, Joong Sup Shim, Collins A. Karikari, Georg Feldmann, Li Hua, Mihoko Kamiyama, F. William Schuler, Ming-Tseh Lin, Robert M. Beaty, Balasubramanyam Karanam, Hong Liang, Michael E. Mullendore, Guanglan Mo, Manuel Hidalgo, Elizabeth Jaffee, Ralph H. Hruban, Richard B. S. Roden, Antonio Jimeno, and Jun O. Liu, of Hopkins; and H. A. Jinnah of Emory University School of Medicine in Atlanta.
The work was supported by the National Institutes of Health, National Cancer Institute (CA130938, CA62924 and CA122581), the Sol Goldman Pancreatic Cancer Research Center, the Stewart Trust Fund, the Lustgarten Foundation, the Mary Lou Wootton Pancreatic Pancreatic Cancer Research Fund, the Michael Rolfe Pancreatic Cancer Foundation and the HERA Foundation.
Rauenzahn, Maitra and Eshleman may receive royalty payments if the mice are licensed, and Eshleman is an advisory board member for Roche Molecular Diagnostics. These relationships have been disclosed and are under the management of the Johns Hopkins University School of Medicine Conflict of Interest Committee. 【283】
Obstacle
Is Death An Illusion? Evidence Suggests Death Isn’t the End
[attachimg=450,350]114419[/attachimg] After the death of his old friend, Albert Einstein said “Now Besso has departed from this strange world a little ahead of me. That means nothing. People like us … know that the distinction between past, present and future is only a stubbornly persistent illusion.” New evidence continues to suggest that Einstein was right – death is an illusion.
Our classical way of thinking is based on the belief that the world has an objective observer-independent existence. But a long list of experiments shows just the opposite. We think life is just the activity of carbon and an admixture of molecules – we live awhile and then rot into the ground.
We believe in death because we’ve been taught we die. Also, of course, because we associate ourselves with our body and we know bodies die. End of story. But biocentrism – a new theory of everything – tells us death may not be the terminal event we think. Amazingly, if you add life and consciousness to the equation, you can explain some of the biggest puzzles of science. For instance, it becomes clear why space and time – and even the properties of matter itself – depend on the observer. It also becomes clear why the laws, forces, and constants of the universe appear to be exquisitely fine-tuned for the existence of life.
Until we recognize the universe in our heads, attempts to understand reality will remain a road to nowhere.
Consider the weather ‘outside’: You see a blue sky, but the cells in your brain could be changed so the sky looks green or red. In fact, with a little genetic engineering we could probably make everything that is red vibrate or make a noise, or even make you want to have sex like with some birds. You think its bright out, but your brain circuits could be changed so it looks dark out. You think it feels hot and humid, but to a tropical frog it would feel cold and dry. This logic applies to virtually everything. Bottom line: What you see could not be present without your consciousness.
In truth, you can’t see anything through the bone that surrounds your brain. Your eyes are not portals to the world. Everything you see and experience right now – even your body – is a whirl of information occurring in your mind. According to biocentrism, space and time aren’t the hard, cold objects we think. Wave your hand through the air – if you take everything away, what’s left? Nothing. The same thing applies for time. Space and time are simply the tools for putting everything together.
Consider the famous two-slit experiment. When scientists watch a particle pass through two slits in a barrier, the particle behaves like a bullet and goes through one slit or the other. But if you don’t watch, it acts like a wave and can go through both slits at the same time. So how can a particle change its behavior depending on whether you watch it or not? The answer is simple – reality is a process that involves your consciousness.
Or consider Heisenberg’s famous uncertainty principle. If there is really a world out there with particles just bouncing around, then we should be able to measure all their properties. But you can’t. For instance, a particle’s exact location and momentum can’t be known at the same time. So why should it matter to a particle what you decide to measure? And how can pairs of entangled particles be instantaneously connected on opposite sides of the galaxy as if space and time don’t exist? Again, the answer is simple: because they’re not just ‘out there’ – space and time are simply tools of our mind.
Death doesn’t exist in a timeless, spaceless world. Immortality doesn’t mean a perpetual existence in time, but resides outside of time altogether.
Our linear way of thinking about time is also inconsistent with another series of recent experiments. In 2002, scientists showed that particles of light “photons” knew – in advance – what their distant twins would do in the future. They tested the communication between pairs of photons. They let one photon finish its journey – it had to decide whether to be either a wave or a particle. Researchers stretched the distance the other photon took to reach its own detector. However, they could add a scrambler to prevent it from collapsing into a particle. Somehow, the first particle knew what the researcher was going to do before it happened – and across distances instantaneously as if there were no space or time between them. They decide not to become particles before their twin even encounters the scrambler. It doesn’t matter how we set up the experiment. Our mind and its knowledge is the only thing that determines how they behave. Experiments consistently confirm these observer-dependent effects.
Bizarre? Consider another experiment that was recently published in the prestigious scientific journal Science (Jacques et al, 315, 966, 2007). Scientists in France shot photons into an apparatus, and showed that what they did could retroactively change something that had already happened in the past. As the photons passed a fork in the apparatus, they had to decide whether to behave like particles or waves when they hit a beam splitter. Later on – well after the photons passed the fork – the experimenter could randomly switch a second beam splitter on and off. It turns out that what the observer decided at that point, determined what the particle actually did at the fork in the past. At that moment, the experimenter chose his past.
Of course, we live in the same world. But critics claim this behavior is limited to the microscopic world. But this ‘two-world’ view (that is, one set of physical laws for small objects, and another for the rest of the universe including us) has no basis in reason and is being challenged in laboratories around the world. A couple years ago, researchers published a paper in Nature (Jost et al, 459, 683, 2009) showing that quantum behavior extends into the everyday realm. Pairs of vibrating ions were coaxed to entangle so their physical properties remained bound together when separated by large distances (“spooky action at a distance,” as Einstein put it). Other experiments with huge molecules called ‘Buckyballs’ also show that quantum reality extends beyond the microscopic world. And in 2005, KHC03 crystals exhibited entanglement ridges one-half inch high, quantum behavior nudging into the ordinary world of human-scale objects.
We generally reject the multiple universes of Star Trek as fiction, but it turns out there is more than a morsel of scientific truth to this popular genre. One well-known aspect of quantum physics is that observations can’t be predicted absolutely. Instead, there is a range of possible observations each with a different probability. One mainstream explanation, the “many-worlds” interpretation, states that each of these possible observations corresponds to a different universe (the ‘multiverse’). There are an infinite number of universes and everything that could possibly happen occurs in some universe. Death does not exist in any real sense in these scenarios. All possible universes exist simultaneously, regardless of what happens in any of them.
Life is an adventure that transcends our ordinary linear way of thinking. When we die, we do so not in the random billiard-ball-matrix but in the inescapable-life-matrix. Life has a non-linear dimensionality – it’s like a perennial flower that returns to bloom in the multiverse.
“The influences of the senses,” said Ralph Waldo Emerson “has in most men overpowered the mind to the degree that the walls of space and time have come to look solid, real and insurmountable; and to speak with levity of these limits in the world is the sign of insanity.” 【1278】
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