Immagine
 Trilingual World Observatory: italiano, english, română. GLOBAL NEWS & more... di Redazione
   
 
\\ Home Page : Storico : en - Science and Society (invert the order)
Di seguito gli interventi pubblicati in questa sezione, in ordine cronologico.
 
 

Many physicists around the world are hard at work trying to figure out new and exciting ways to create ultra-cold objects, the reason being is that if a system could be created that operates at or at least very near absolute zero, superconductors could be devised that might help create quantum computers, which would of course run at speeds that would make the current generation look quaint. Plus, theory suggests new states of matter might be discovered.

Now, new work by a group of physicists from Harvard appears to be coming closer than ever. They’ve figured out a way to remove entropy from a specialized system leaving much colder atoms behind. In their paper, published in Nature, they discuss how they’ve come up with something called an orbital excitation blockade, a form of interaction blockade, to reach temperatures tens to hundreds of times colder than current methods.

The team did their research in a three step process. In the first they shot atoms that make up rubidium with a laser, forcing them to glow in a way that made them give off more energy then they absorbed, making them cooler of course. By doing so they also created a system whereby they were able to control the atoms due to the pressure created by the laser. Thus they could hold them still, move them around, or even cause them to run into each other.

Next, the team caused the atoms to grow even colder by allowing evaporative cooling to due its work.

After that, the real work began. Here the team used meshes of lasers, called optical lattices to remove entropy from the system. The already cooled atoms were made to knock into one another using lasers ala the method used to start the whole process; this time in the optical lattices. In so doing, the excited activity of atom one dampened the excited activity of the other, a process the team calls an orbital excitation blockade. The team then removed the excited atoms from the system, leaving the unexcited, cold atoms behind, in effect, removing entropy from the system.

In actual experiments done thus, far, the team has demonstrated an ability to actually remove heat from a system using their excitation blockade, but only to a certain point. They believe more research will allow them to reach temperatures tens or even hundreds of a billionth of a degree above absolute zero, which would take them into truly unknown territory.

More information: Orbital excitation blockade and algorithmic cooling in quantum gases, Nature, 480, 500–503 (22 December 2011) doi:10.1038/nature10668

Abstract

Interaction blockade occurs when strong interactions in a confined, few-body system prevent a particle from occupying an otherwise accessible quantum state. Blockade phenomena reveal the underlying granular nature of quantum systems and allow for the detection and manipulation of the constituent particles, be they electrons, spins, atoms or photons. Applications include single-electron transistors based on electronic Coulomb blockade7 and quantum logic gates in Rydberg atoms. Here we report a form of interaction blockade that occurs when transferring ultracold atoms between orbitals in an optical lattice. We call this orbital excitation blockade (OEB). In this system, atoms at the same lattice site undergo coherent collisions described by a contact interaction whose strength depends strongly on the orbital wavefunctions of the atoms. We induce coherent orbital excitations by modulating the lattice depth, and observe staircase-like excitation behaviour as we cross the interaction-split resonances by tuning the modulation frequency. As an application of OEB, we demonstrate algorithmic cooling of quantum gases: a sequence of reversible OEB-based quantum operations isolates the entropy in one part of the system and then an irreversible step removes the entropy from the gas. This technique may make it possible to cool quantum gases to have the ultralow entropies required for quantum simulation of strongly correlated electron systems. In addition, the close analogy between OEB and dipole blockade in Rydberg atoms provides a plan for the implementation of two-quantum-bit gates in a quantum computing architecture with natural scalability.

A Harvard University press release can be found below:

Physicists at Harvard University have realized a new way to cool synthetic materials by employing a quantum algorithm to remove excess energy. The research, published this week in the journal Nature, is the first application of such an "algorithmic cooling" technique to ultra-cold atomic gases, opening new possibilities from materials science to quantum computation.

"Ultracold atoms are the coldest objects in the known universe," explains senior author Markus Greiner, associate professor of Physics at Harvard. "Their temperature is only a billionth of a degree above absolute zero temperature, but we will need to make them even colder if we are to harness their unique properties to learn about quantum mechanics."

Greiner and his colleagues study quantum many-body physics, the exotic and complex behaviors that result when simple quantum particles interact. It is these behaviors which give rise to high-temperature superconductivity and quantum magnetism, and that many physicists hope to employ in quantum computers.

"We simulate real-world materials by building synthetic counterparts composed of ultra-cold atoms trapped in laser lattices," says co-author Waseem Bakr, a graduate student in physics at Harvard. "This approach enables us to image and manipulate the individual particles in a way that has not been possible in real materials."

The catch is that observing the quantum mechanical effects that Greiner, Bakr and colleagues seek requires extreme temperatures.

"One typically thinks of the quantum world as being small," says Bakr, " but the truth is that many bizarre features of quantum mechanics, like entanglement, are equally dependent upon extreme cold."

The hotter an object is, the more its constituent particles move around, obscuring the quantum world much as a shaken camera blurs a photograph.

The push to ever-lower temperatures is driven by techniques like "laser cooling" and "evaporative cooling," which are approaching their limits at nanoKelvin temperatures. In a proof-of-principle experiment, the Harvard team has demonstrated that they can actively remove the fluctuations which constitute temperature, rather than merely waiting for hot particles to leave as in evaporative cooling.

Akin to preparing precisely one egg per dimple in a carton, this "orbital excitation blockade" process removes excess atoms from a crystal until there is precisely one atom per site.

"The collective behaviors of atoms at these temperatures remain an important open question, and the breathtaking control we now exert over individual atoms will be a powerful tool for answering it," said Greiner. "We are glimpsing a mysterious and wonderful world that has never been seen in this way before."

Source: PhysOrg - via ZeitNews.org

 
By Admin (from 14/04/2012 @ 08:06:55, in en - Science and Society, read 1476 times)

While fuel cells show a lot of promise for cleanly powering things such as electric cars, there's something keeping them from being more widely used than they currently are - they can be expensive. More specifically, the catalysts used to accelerate the chemical processes within them tend to be pricey. Work being done at Finland's Aalto University, however, should help bring down the cost of fuel cells. Using atomic layer deposition (ALD), researchers there are making cells that incorporate 60 percent less catalyst material than would normally be required.

In a fuel cell, the anode is coated with noble metal powder, which serves as a catalyst by reacting with the fuel. Using their ALD method, the scientists were able to use less powder to create a coating that was thinner and more even than conventional coatings, yet just as effective.

While fuel cells can be made with a number of different fuels (even including microbes or coal) and noble metals, the Aalto team is now developing low-cost cells that will run on methanol or ethanol, with a palladium catalyst. Probably the most well-known fuel cells are those that run on hydrogen, but such cells require a catalyst made of platinum, which is twice the price of palladium.

A paper on the research was recently published in the Journal of Physical Chemistry C.

Source: Gizmag - via ZeitNews.org

 

Researchers from Northwestern University, Rush University Medical Center, Chicago, and the University of Duisburg-Essen Germany found that graphitic carbon is a key element in a lubricating layer that forms on metal-on-metal hip implants. The lubricant is more similar to the lubrication of a combustion engine than that of a natural joint.

The study was published on Dec. 23 2011 by the journal Science.

Prosthetic materials for hips, which include metals, polymers and ceramics, have a lifetime typically exceeding 10 years. However, beyond 10 years the failure rate generally increases, particularly in young, active individuals. Physicians would love to see that lifespan increased to 30 to 50 years. Ideally, artificial hips should last the patient's lifetime.

This is an X-ray of the hip region with a metal-on-metal implant superimposed and a schematic illustrating graphitic material on the surface of the implant. The red spheres represent the positions of the carbon atoms in a single layer of graphite. Credit: Northwestern University

"Metal-on-metal implants can vastly improve people's lives, but it's an imperfect technology," said Laurence D. Marks, a co-author on the paper who led the experimental effort at Northwestern. "Now that we are starting to understand how lubrication of these implants works in the body, we have a target for how to make the devices better."

Marks is a professor of materials science and engineering at Northwestern's McCormick School of Engineering and Applied Science.

The ability to extend the life of implants would have enormous benefits, in terms of both cost and quality of life. More than 450,000 Americans, most with severe arthritis, undergo hip replacement each year, and the numbers are growing. Many more thousands delay the life-changing surgery until they are older, because of the limitations of current implants.

"Hip replacement surgery is the greatest advancement in the treatment of end-stage arthritis in the last century," said co-author and principal investigator Dr. Joshua J. Jacobs, the William A. Hark, M.D./Susanne G. Swift Professor of Orthopedic Surgery and professor and chair of the department of orthopedic surgery at Rush. "By the time patients get to me, most of them are disabled. Life is unpleasant. They have trouble working, playing with their grandchildren or walking down the street. Our findings will help push the field forward by providing a target to improve the performance of hip replacements. That's very exciting to me."

Earlier research by team members Alfons Fischer at the University of Duisburg-Essen and Markus Wimmer at Rush University Medical Center discovered that a lubricating layer forms on metallic joints as a result of friction. Once formed, the layer reduces friction as well as wear and corrosion. This layer is called a tribological layer and is where the sliding takes place, much like how an ice skate slides not on the ice but on a thin layer of water.

But, until now, researchers did not know what the layer was. (It forms on the surfaces of both the ball and the socket.) It had been assumed that the layer was made of proteins or something similar in the body that got into the joint and adhered to the implant's surfaces.

The interdisciplinary team studied seven implants that were retrieved from patients for a variety of reasons. The researchers used a number of analytical tools, including electron and optical microscopies, to study the tribological layer that formed on the metal parts. (An electron microscope uses electrons instead of light to image materials.)

The electron-energy loss spectra, a method of examining how the atoms are bonded, showed a well-known fingerprint of graphitic carbon. This, together with other evidence, led the researchers to conclude that the layer actually consists primarily of graphitic carbon, a well-established solid lubricant, not the proteins of natural joints.

"This was quite a surprise," Marks said, "but the moment we realized what we had, all of a sudden many things started to make sense."

Metal-on-metal implants have advantages over other types of implants, Jacobs said. They are a lower wear alternative to metal-on-polymer devices, and they allow for larger femoral heads, which can reduce the risk of hip dislocation (one of the more common reasons for additional surgery). Metal-on-metal also is the only current option for a hip resurfacing procedure, a bone-conserving surgical alternative to total hip replacement.

"Knowing that the structure is graphitic carbon really opens up the possibility that we may be able to manipulate the system in a way to produce graphitic surfaces," Fischer said. "We now have a target for how we can improve the performance of these devices."

"Nowadays we can design new alloys to go in racing cars, so we should be able to design new materials for implants that go into human beings," Marks added.

The next phase, Jacobs said, is to examine the surfaces of retrieved devices and correlate the researchers' observations of the graphitic layer with the reason for removal and the overall performance of the metal surfaces. Marks also hopes to learn how graphitic debris from the implant might affect surrounding cells.

The science of tribology is the study of friction, lubrication and wear. The term comes from the Greek word "tribos," meaning rubbing or sliding.

More information: The Science paper is titled "Graphitic Tribological Layers in Metal-on-Metal Hip Replacements."

Source: Northwestern University - via ZeitNews.org

 

Those are the findings of a new study by researchers at Jacksonville University and the University of California, Davis. The study appears in the journal Child Development.

In the study, researchers looked at 90 mostly White children ages 5 to 10. The children listened to six illustrated stories in which two characters feel the same emotion after experiencing something positive (getting a new puppy), negative (spilling milk), or ambiguous (meeting a new teacher). Following each experience, one character has a separate optimistic thought, framing the event in a positive light, and the other has a separate pessimistic thought, putting the event in a negative light. Researchers described the subsequent thoughts verbally, then asked the children to judge each character's emotions and provide an explanation for those emotions. They were most interested in the degree to which children predicted different emotions for two characters in the same situation.

The researchers also had the children and their parents complete surveys to measure their individual levels of hope and optimism.

Children as young as 5 predicted that people would feel better after thinking positive thoughts than they would after thinking negative thoughts. They showed the strongest insight about the influence of positive versus negative thoughts on emotions in ambiguous situations. And there was significant development in the children's understanding about the emotion-feeling link as they grew older.

The study also found that children had the most difficulty understanding how positive thinking could boost someone's spirits in situations that involved negative events—such as falling down and getting hurt. In these coping situations, children's levels of hope and optimism played a role in their ability to understand the power of positive thinking, but parents' views on the topic played an even larger part.

"The strongest predictor of children's knowledge about the benefits of positive thinking—besides age—was not the child's own level of hope and optimism, but their parents'," reports Christi Bamford, assistant professor of psychology at Jacksonville University, who led the study when she was at the University of California, Davis.

The findings point to parents' role in helping children learn how to use positive thinking to feel better when things get tough, Bamford notes. "In short, parents should consider modeling how to look on the bright side."

Source: EurekAlert - via ZeitNews.org

 

The children played a unique game when they were 2- to 4-year-olds. In the game, children placed a large object in a hole at the top of a machine and turned a handle on the side. When a bell rang, a small but otherwise identical object was delivered through a door at the bottom of the machine.

Six years later, the researchers interviewed the children and their parents to determine how well they remembered playing the game. Only about a fifth of the children recalled the event, including two children who were under 3 years old when they played the game. About half of the parents remembered the event. Parents and children who recalled the event provided very similar reports about the game.

Although the researchers couldn't predict children's long-term recall on the basis of the youngsters' general memory and language skills, they found evidence that talking about the event soon after it occurred may have helped preserve it in the memories of those who remembered it.

"Our results are consistent with theories that suggest that basic capacity for remembering our own experiences may be in place by 2 years of age," according to Fiona Jack, postdoctoral fellow at the University of Otago, who led the study. "The study has implications in clinical and legal settings, where it is often important to know how likely it is that a particular memory of an early experience is in fact genuine."

Source: MedicalXpress - via ZeitNews.org

 

After a week, the pattern of the stamp "is written in blood vessels," the researchers report.

A paper describing the new approach will appear as the January 2012 cover article of the journal Advanced Materials.

"Any kind of tissue you want to rebuild, including bone, muscle or skin, is highly vascularized," said University of Illinois chemical and biomolecular engineering professor Hyunjoon Kong, a co-principal investigator on the study with electrical and computer engineering professor Rashid Bashir. "But one of the big challenges in recreating vascular networks is how we can control the growth and spacing of new blood vessels."

"The ability to pattern functional blood vessels at this scale in living tissue has not been demonstrated before," Bashir said. "We can now write features in blood vessels."

Other laboratories have embedded growth factors in materials applied to wounds in an effort to direct blood vessel growth. The new approach is the first to incorporate live cells in a stamp. These cells release growth factors in a more sustained, targeted manner than other methods, Kong said.

The stamp is nearly 1 centimeter across and is built of layers of a hydrogel made of polyethylene glycol (an FDA-approved polymer used in laxatives and pharmaceuticals) and methacrylic alginate (an edible, Jell-O-like material). The stamp is porous, allowing small molecules to leak through, and contains channels of various sizes to direct the flow of larger molecules, such as growth factors.

The researchers tested the stamp on the surface of a chicken embryo. After a week the stamp was removed, revealing a network of new blood vessels that mirrored the pattern of the channels in the stamp.

"This is a first demonstration that the blood vessels are controlled by the biomaterials," Kong said.

The researchers see many potential applications for the new stamp, from directing the growth of blood vessels around a blocked artery, to increasing the vascularization of tissues with poor blood flow, to "normalizing" blood vessels that feed a tumor to improve the delivery of anti-cancer drugs. Enhancing the growth of new blood vessels in a coordinated pattern after surgery may also reduce recovery time and lessen the amount of scar tissue, the researchers said.

In another study published in 2011, the team developed a biodegradable material that supports living cells. Future research will test whether the new material also can be used a stamp.

More information: The paper, "Living Microvascular Stamp for Patterning of Functional Neovessels; Orchestrated Control of Matrix Property and Geometry," is available online.

Source: University of Illinois at Urbana-Champaign - via ZeitNews.org

 

We only have to look at something to know what it is.

But teaching a computer to "know" what it’s looking at is far harder. In research published this fall in the Public Library of Science (PLoS) Computational Biology journal, a team from Los Alamos National Laboratory, Chatham University, and Emory University first measured human performance on a visual task ? identifying a certain kind of shape when an image is flashed in front of a viewer for a very short amount of time (20-200 milliseconds). Human performance gets worse, as expected, when the image is shown for shorter time periods. Also as expected, humans do worse when the shapes are more complicated.

But could a computer be taught to recognize shapes as well, and then do it faster than humans? The team tried developing a computer model based on human neural structure and function, to do what we do, and possibly do it better.

Their paper, "Model Cortical Association Fields Account for the Time Course and Dependence on Target Complexity of Human Contour Perception," describes how, after measuring human performance, they created a computer model to also attempt to pick out the shapes.

"This model is biologically inspired and relies on leveraging lateral connections between neurons in the same layer of a model of the human visual system," said Vadas Gintautas of Chatham University in Pittsburgh and formerly a researcher at Los Alamos.

Neuroscientists have characterized neurons in the primate visual cortex that appear to underlie object recognition, noted senior author Garrett Kenyon of Los Alamos. "These neurons, located in the inferotemporal cortex, can be strongly activated when particular objects are visible, regardless of how far away the objects are or how the objects are posed, a phenomenon referred to as viewpoint invariance."

The brain has an uncanny ability to detect and identify certain things, even if they’re barely visible. Now the challenge is to get computers to do the same thing. And programming the computer to process the information laterally, like the brain does, might be a step in the right direction.

How inferotemporal neurons acquire their viewpoint invariant properties is unknown, but many neuroscientists point to the hierarchical organization of the human visual cortex as likely being an essential aspect.

"Lateral connections have been generally overlooked in similar models designed to solve similar tasks. We demonstrated that our model qualitatively reproduces human performance on the same task, both in terms of time and difficulty. Although this is certainly no guarantee that the human visual system is using lateral interactions in the same way to solve this task, it does open up a new way to approach object detection problems," Gintautas said.

Simple features, such as particular edges of the image in a specific orientation, are extracted at the first cortical processing stage, called the primary visual cortex, or V1. Then subsequent cortical processing stages, V2, V4, etc., extract progressively more complex features, culminating in the inferotemporal cortex where that essential "viewpoint invariant object identification" is thought to occur. But, most of the connections in the human brain do not project up the cortical hierarchy, as might be expected from gross neuroanatomy, but rather connect neurons located at the same hierarchical level, called lateral connections, and also project down the cortical hierarchy to lower processing levels.

In the recently published work, the team modeled lateral interactions between cortical edge detectors to determine if such connections could explain the difficulty and time course of human contour perception. This research thus combined high-performance computer simulations of cortical circuits, using a National Science Foundation funded neural simulation toolbox, called PetaVision, developed by LANL researchers, along with “speed-of-sight” psychophysical measurements of human contour perception. The psychophysical measurements refer to an experimental technique that neuroscientists use to study mechanisms of cortical processing, using the open-source Psychtoolbox software as an advanced starting point.

"Our research represented the first example of a large-scale cortical model being used to account for both the overall accuracy, as well as the processing time, of human subjects performing a challenging visual-perception task," said Kenyon.

More information: Link to PLoS paper: http://www.ploscom … pcbi.1002162

Source: PhysOrg - via ZeitNews.org

 

The scientists from the Jenner Institute at the University of Oxford have shown that their vaccine induces an antibody response in animal models that is capable of neutralising all the strains they tested of the malaria parasite Plasmodium falciparum.

The group led by Dr Simon Draper, with colleagues from the Wellcome Trust Sanger Institute and the Kenyan Medical Research Institute-Wellcome Trust Programme in Kilifi, Kenya, have published their findings in the journal Nature Communications.

The results add to a key discovery reported last month. Scientists at the Wellcome Trust Sanger Institute identified a potential ‘Achilles’ heel’ in the malaria parasite that could hold significant promise for vaccine development.

Their research published in the journal Nature showed that the P. falciparum parasite relies on a single protein – the antigen RH5 – to ‘unlock’ the doorway for the parasite to enter red blood cells. Once there, it grows and replicates, causing potentially life-threatening disease.

Lead researcher Dr Sandy Douglas of the University of Oxford says: ‘We have created a vaccine that confirms the recent discovery relating to the biology of RH5, given it can generate an immune response in animal models capable of neutralising many – and potentially all – strains of the P. falciparum parasite, the deadliest species of malaria parasite. This is an important step towards developing a much-needed vaccine against one of the world’s major killers.’

Malaria killed around 800,000 people in 2009, mainly young children and pregnant women. It is caused by parasites that are carried by mosquitoes. The most deadly form, P. falciparum, is responsible for nine out of ten deaths from malaria.

Vaccination is likely to be the most cost-effective way of protecting people against malaria. However, no licensed vaccine is currently available. While one vaccine is achieving promising but incomplete levels of protection in clinical trials in Africa, scientists believe a new and more effective vaccine will be required to eradicate the disease.

Professor Adrian Hill, director of the Jenner Institute at the University of Oxford, says: ‘Vaccines against malaria are notoriously difficult to develop because the parasites’ antigens – the target of vaccines – tend to be genetically so diverse. The RH5 antigen doesn’t show this diversity, making it a particularly good target for a vaccine to exploit. Our next step will be to begin safety tests of this vaccine. If these prove successful, we could see clinical trials in patients beginning within the next two to three years.’

The research was funded by the Wellcome Trust, with other support from organisations including the UK Medical Research Council.

Source: Oxford University - via ZeitNews.org

 

The report for the charity Crisis found an average homeless person has a life expectancy of 47, compared with 77 for the rest of the population.

Drug and alcohol abuse account for a third of all deaths among the homeless.

The report comes as the government is set to announce that Ł20m will be spent to provide assistance to single people facing homelessness.

The Sheffield University report said that while drug and alcohol abuse often lead to homelessness, being without a home exacerbates the problem.

And while the overall average of death for men and women who were homeless was 47, the mean age of death for women was found to be even lower, at 43.

It was not just people sleeping on the streets who were studied, the wider homeless population which include those who live in night shelters, hostels and who use day centres were also considered.

General population

Researchers found that homeless people are nine times more likely to commit suicide than the rest of the population and deaths as a result of traffic accidents are three times more common.

Crisis' chief executive, Leslie Morphy, said that significant investment in the NHS had not helped homeless people to address their health issues.

"It is shocking, but not surprising, that homeless people are dying much younger than the general population," she said.

"Life on the streets is harsh and the stress of being homeless is clearly taking its toll."

A Department of Health spokesman said: "We know that many homeless people have acute and often multiple health needs.

"That is why we have established the Inclusion Health programme, which focuses on improving access to healthcare, and the results it achieves, for vulnerable groups such as rough sleepers."

The charity Shelter has also highlighted the plight of the 70,000 children they say will spend Christmas in temporary accommodation without a permanent home.

Shelter said the problem has not been fully addressed.

It pointed to the latest government figures which showed 69,846 children in England have to live in hostels, bed and breakfasts and refuges. That figure compares to more than 112,000 in 2007.

The charity's director of communications, policy and campaigns, Kay Boycott, said: "We cannot underestimate the damage homelessness has on children's lives.

"They often miss out on vital schooling because they are shunted from place to place and many become ill by the poor conditions they are forced to live in."

Council co-ordination

Housing Minister Grant Shapps responded by saying that the government would try to help anyone in need.

"The plight of homeless people should be on our minds all year round - not just at Christmas," he said.

"We're fortunate to have some of the toughest laws in the world to prevent people from ending up on our streets, and while homelessness remains lower than in 28 of the last 30 years I'm always anxious to do more.

"That's why I'm announcing Ł20m of new funding which, for the first time, will specifically help single homeless people, who all too often slip through the safety net. This money will be used to help prevent homelessness at an earlier stage."

Mr Shapps also said he will be asking councils to work together to decide how best to use the cash to meet local needs.

The Ł20m funding is in addition to the existing Ł400m Preventing Homelessness grant over the next four years and will be made available in the new year.

Source: BBC - via ZeitNews.org

 

Normal cells usually die in the lab after dividing only a few times, and many common cancers will not grow, unaltered, outside of the body.

This new technique could be the critical advance that ushers in a new era of personalized cancer medicine, and has potential application in regenerative medicine, says the study’s senior investigator, Richard Schlegel, M.D., Ph.D., chairman of the department of pathology at Georgetown Lombardi Comprehensive Cancer Center.

“Because every tumor is unique, this advance will make it possible for an oncologist to find the right therapies that both kills a patient’s cancer and spares normal cells from toxicity,” he says. “We can test resistance as well chemosensitivity to single or combination therapies directly on the cancer cell itself.”

The research team, which also includes several scientists from the National Institutes of Health, found that adding two different substances to cancer and normal cells in a laboratory pushes them to morph into stem-like cells — adult cells from which other cells are made.

The two substances are a Rho kinase (ROCK) inhibitor and fibroblast feeder cells. ROCK inhibitors help stop cell movement, but it is unclear why this agent turns on stem cell attributes, Schlegel says. His co-investigator Alison McBride, Ph.D., of the National Institute of Allergy and Infectious Diseases, had discovered that a ROCK inhibitor allowed skin cells (keratinocytes) to reproduce in the laboratory while feeder cells kept them alive.

The Georgetown researchers — 13 investigators in the departments of pathology and oncology — tried ROCK inhibitors and fibroblast feeder cells on the non-keratinocyte epithelial cells that line glands and organs to see if they had any effect. They found that both were needed to produce a dramatic effect in which the cells visibly changed their shape as they reverted to a stem-like state..”

“In short, we discovered we can grow normal and tumor cells from the same patient forever, and nobody has been able to do that,” he says. “Normal cell cultures for most organ systems can’t be established in the lab, so it wasn’t possible previously to compare normal and tumor cells directly.”

The ability to immortalize cancer cells will also make biobanking both viable and relevant, Schlegel says. The researchers further discovered that the stem-like behavior in these cells is reversible. Withdrawing the ROCK inhibitor forces the cells to differentiate into the adult cells that they were initially. This “conditional immortalization” could help advance the field of regenerative medicine, Schlegel says.

However, the most immediate change in medical practice from these findings is the potential they have in “revolutionizing what pathology departments do,” Schlegel says.

“Today, pathologists don’t work with living tissue. They make a diagnosis from biopsies that are either frozen or fixed and embedded in wax,” he says. “In the future, pathologists will be able to establish live cultures of normal and cancerous cells from patients, and use this to diagnose tumors and screen treatments. That has fantastic potential.”

Source: Kurzweil Accelerating Intelligence

 
Ci sono 4290 persone collegate

< maggio 2021 >
L
M
M
G
V
S
D
     
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
           

Titolo
en - Global Observatory (605)
en - Science and Society (594)
en - Video Alert (346)
it - Osservatorio Globale (503)
it - Scienze e Societa (555)
it - Video Alerta (132)
ro - Observator Global (399)
ro - Stiinta si Societate (467)
ro - TV Network (149)
z - Games Giochi Jocuri (68)

Catalogati per mese - Filed by month - Arhivate pe luni:

Gli interventi piů cliccati

Ultimi commenti - Last comments - Ultimele comentarii:
Hi, it's Nathan!Pretty much everyone is using voice search with their Siri/Google/Alexa to ask for services and products now, and next year, it'll be EVERYONE of your customers. Imagine what you are ...
15/01/2019 @ 17:58:25
By Nathan
Now Colorado is one love, I'm already packing suitcases;)
14/01/2018 @ 16:07:36
By Napasechnik
Nice read, I just passed this onto a friend who was doing some research on that. And he just bought me lunch since I found it for him smile So let me rephrase that Thank you for lunch! Whenever you ha...
21/11/2016 @ 09:41:39
By Anonimo


Titolo





15/05/2021 @ 13:02:36
script eseguito in 747 ms