Einstein's prediction finally witnessed ON century later

Einstein said it couldn't be done. But more than one hundred years later physicists at the University of Texas at Austin have finally found a way to witness “Brownian motion”; the instantaneous velocity of tiny particles as they vibrate. The “equipartition theorem” states that a particle's kinetic energy, that due to motion, is determined only by its temperature and not its size or mass, and in 1907 Einstein proposed a test to observe the velocity of Brownian motion but gave up, saying the experiment would never be possible.

More than a century later Mark Raizen and his team have finally proved this long-anticipated prediction by means of “optical tweezers”: a single laser beam was fired at a 5μm micrometer bead from below, suspending the bead in an “optical trap” mid-air using the force from the laser and the gravitational force on the bead. A plate-like transducer shook the beads to be tweezed and measured them as they were suspended, and the Brownian motion of the trapped bead was studied with ultra-high resolution.

Having noted that in this case glass beads were 3 micrometers across, Raizen and his team have proved that equipartition theorem is in fact true for Brownian particles. This is the first time in history that the equipartition theorem has been tested for Brownian particles, which forms one of the basic principles of statistical mechanics. They now intend to go further by moving the particles closer to a quantum state for observation. They also expect this to stimulate further research into cooling glass beads to a state where they could be used as oscillators or sensors.

As with much of quantum science, they don't expect the experiment to yield more answers than questions, however: “We've now observed the instantaneous velocity of a Brownian particle," says Raizen. "In some sense, we're closing a door on this problem in physics. But we are actually opening a much larger door for future tests of the equipartition theorem at the quantum level."

Mark Raizen is professor of physics at The University of Texas at Austin, and the Sid W. Richardson Foundation Regents Chair. His co-authors are Tongcang Li, Simon Kheifets and David Medellin of the Center for Nonlinear Dynamics and the Department of Physics at The University of Texas at Austin. Their paper is published in Science.

Microfluidic device aids

Neutrophils are the most abundant type of white blood cell, and are part of the body’s first line of defense at the sites of injuries or infections. They were originally thought to do simple things like releasing antimicrobial proteins and ingesting pathogens. Recently, however, researchers have come to realize that they play a key role in both chronic and acute inflammation, and in the activation of the immune system in response to injury. Of course, the best way to study neutrophils is to get a hold of some, but that hasn’t been particularly easy. 

 Traditional methods have required relatively large blood samples, and take up to two hours. Because neutrophils are sensitive to handling, it is also possible to inadvertently activate them, which alters their molecular patterns. A microfluidic device developed at the Massachusetts General Hospital (MGH), however, allows for neutrophils to be collected from a relatively small blood sample, unactivated, in just minutes.

The team from the MGH Center for Engineering in Medicine already had experience in developing silicon-chip-based cell-capturing devices, having designed ones for obtaining CD4 T cells for HIV diagnosis and isolating circulating tumor cells. For this latest device, they redesigned the geometry, the anti-body based coating, and other aspects of the cell-capture module at the heart of the technology. They were subsequently able to gather a neutrophil-rich sample from a microliter-sized blood sample in under five minutes. Because the procedure took so little time, the neutrophils remained relatively undisturbed. When analyzed, the samples revealed differences in gene and protein activity relevant to the cells' activation status.

To test the device further, six copies of it were sent to various real-world clinical environments, to study the neutrophils’ reaction to traumatic injuries. In analyzing samples from 26 patients, complex gene expression patterns were discovered, that shifted during a 28-day period after the injury. It is assumed that these shifts reflect interactions between various immune system components.

"Until now, it's been logistically impossible to study neutrophils to the extent we have in this paper,” said lead author Kenneth Kotz, of MGH. "This technology – which is much faster and gentler than current approaches to isolating cells – can be scaled and modified to capture just about any cell type, and we're working to apply it to other cell-based assays."

A paper on the device has recently been published in the journal Nature Medicine.

Reference

MGH Center for Engineering in Medicine

Nature Medicine. 

Researching created liver cells disorders

Researching liver disorders is extremely difficult because liver cells (hepatocytes) cannot be grown in the laboratory. However, researchers at the University of Cambridge have now managed to create diseased liver cells from a small sample of human skin. The research shows that stem cells can be used to model a diverse range of inherited disorders and paves the way for new liver disease research and possible cell-based therapy.

 

human liver

Liver disease on the rise

In the UK, liver disease is the fifth largest cause of death after cardiovascular, cancer, stroke, and respiratory diseases. Over the past 30 years mortality from liver disease in young and middle-aged people has increased over six times, with the number of individuals dying from the disease increasing at a rate of 8-10 percent every year.

By 2012, the UK is expected to have the highest liver disease death rates in Europe and, without action to tackle the disease, it could overtake stroke and coronary heart disease as the leading cause of death within the next 10-20 years. In the United States, it accounts for approximately 25,000 deaths a year.

Cell-based therapy?

By replicating the liver cells, researchers can not only investigate exactly what is happening in a diseased cell, they can also test the effectiveness of new therapies to treat these conditions. It is hoped that their discovery will lead to tailored treatments for specific individuals and eventually cell-based therapy – when cells from patients with genetic diseases are 'cured' and transplanted back. Additionally, as the process could be used to model cells from other parts of the body, their findings could have implications for conditions affecting other organs.

For their research, the scientists took skin biopsies from seven patients who suffered from a variety of inherited liver diseases and three healthy individuals (the control group). They then reprogrammed cells from the skin samples back into stem cells. These stem cells were then used to generate liver cells which mimicked a broad range of liver diseases – the first time patient-specific liver diseases have been modeled using stem cells – and to create 'healthy' liver cells from the control group. Importantly, the three diseases the scientists modeled covered a diverse range of pathological mechanisms, thereby demonstrating the potential application of their research on a wide variety of disorders.

Dr Tamir Rashid of the Laboratory for Regenerative Medicine, University of Cambridge, lead author of the paper detailing the team’s findings, said: "We know that given the shortage of donor liver organs alternative strategies must urgently be sought. Our study improves the possibility that such alternatives will be found – either using new drugs or a cell-based therapeutic approach."

The University of Cambridge researchers' findings were published in The Journal of Clinical Investigation.

Frog skin

While kissing a frog might not transform him into a handsome prince, his skin might one day save your life. Scientists in Abu Dhabi have discovered a method for using the natural substances found in frog skins to create a powerful new group of antibiotics with potential to fight against drug-resistant infections.

At the 240th National Meeting of the American Chemical Society, the team of researchers led by Dr. Michael Conlon, a biochemist at the United Arab Emirates University in Al-Ain, Abu Dhabi Emirate, explained how they have identified more than 100 antibiotic substances in the skins of different frog species from around the world. He also highlighted how one of the hundred has the ability to fight "Iraqibacter," the bacterium responsible for drug-resistant infections in wounded soldiers returning from Iraq.

Dr. Conlon went on to explain how the emergence of drug-resistant bacteria, which generally shrug off conventional antibiotics, is a growing concern worldwide. Thus there is a need to create new drugs to replace the types of antibiotics that no longer work.

"Frog skin is an excellent potential source of such antibiotic agents," said Conlon. “They've been around 300 million years, so they've had plenty of time to learn how to defend themselves against disease-causing microbes in the environment. Their own environment includes polluted waterways where strong defenses against pathogens are a must."

It has been known for many years that the frog’s skin is a rich source of chemicals with the potential to fight against many forms of bacteria, viruses and fungi. However the problem has been the fact the frog antibiotics tend to be toxic to human cells. Dr. Conlon and team have created a new technique which tweaks the molecular structure of frog skin antibiotic substances, resulting in a powerful germ killer that is less toxic to human cells. The frog secretions can be altered to resist attack by destructive enzymes in the bloodstream and become powerful, long lasting antibiotics. Dr. Conlon went on to explain how the frog antibiotics work in an unusual manner, preventing disease-causing microbes from developing a resistance.

Currently the scientists are screening skin secretions from more than 6,000 species of frogs, specifically for antibiotic research. To date they have discovered the chemical structure of close to 200, leaving room for many more antibiotic substances to be determined. "Many people are working with me, giving me samples of frog skin secretions," said Dr. Conlon, who in addition to his team in Abu Dhabi has several research collaborators in Japan, France, the United States, amongst other countries. "We only actually use the frogs to get the chemical structure of the antibiotic, and then we make it in the lab. We take great care not to harm these delicate creatures, and scientists return them to the wild after swabbing their skin for the precious secretions" added Dr. Conlon.

One exciting discovery came from the skin secretions of the Foothill Yellow-Legged Frog, a species found in California and Oregon which is now facing extinction. This secretion illustrated promise for fighting Methicillin-Resistant Staphylococcus Aureus (MRSA) bacteria. MRSA is a "superbug" often responsible for causing fatal infections within hospitalized patients, schools, nursing homes and day care centers. In addition, as previously mentioned, the skin of the Mink Frog contains secretions that may fight "Iraqibacter," caused by multidrug-resistant Acinetobacter Baumanni.

Dr. Conlon is hoping that some of the antibiotics could be used in clinical trial within the coming years. Amongst creating powerful vaccines and treatments for drug-resistant infections throughout the body, the secretions could also be used in ointments to treat simple skin infections.

Old School Technology for Inspiration

How old school? How about 3,000 years old. While working on a housing project in Labrador, workers uncovered tools, weapons, and other artifacts from a period where we don’t really know terribly much about how people lived. First, you’re wondering how this guy knows this. My undergrad degree is in Anthropology with a focus on Archaeology and Quaternary Geology (that’s the geology of the last 1.5 million years to the present) and my Masters degree is in paleoecology (past environments) and global climate change. Yes, the “so why are you writing tech stuff” is a question I’m asked a lot. Regardless, the second question you might be wondering (or should be wondering) is how this relates to technology now. Well that’s easy:

Inspiration and innovation.

Here’s an artifact from my own collection (I found it some backfill so it has little archaeological value):

Artifact from my personal collection, SD card for scale.

My sense is that it’s an axe or scraper from a period about (guessing) the same time as the ones in Labrador (maybe earlier). Now look at this another way, these artifacts started as rocks. Just a hunk of stone. Nothing. Then someone got an idea. What if it were sharper on one part? Maybe if it were shaped differently we could hold it better? Maybe if we used this rock (e.g. Flint or chert) instead of that rock (say, sandstone) the tool might work better? And this, friends and readers, is how technology still works. We see a problem and then someone finds a solution.

This is the challenge we all need to keep in mind. Is something not working? Can it work better? Do you have a great idea for how to fix it? We might not be bashing rocks together to make tools, but we certainly have a ton of tools to attack more and more challenges that we now. Looking at current technological landscape Canada, there is a lot going on and some really interesting developments (beyond the ever-present RIM). This is the mandate of The Next Web Canada: highlight the great stuff, challenge our ways of working and thinking.

simulates effects of spaceflight by tricking the brain

There are airplanes and swimming pools that give prospective astronauts a taste of what a zero-gravity environment will feel like, but the sensations that they will feel upon returning from such an environment are also important to simulate. Astronauts coming back to Earth’s gravity often experience disturbances in their vision and neurological function, to the point that they can have trouble walking, keeping their balance, or even safely landing their spacecraft. By utilizing a Galvanic vestibular stimulation (GVS) system, however, scientists can give them a sneak peek of what to expect, so they can better compensate for it when it happens in the field.

The system was developed by Dr. Steven Moore of the National Space Biomedical Research Institute (NSBRI). It consists of a small box, which sends a 5 milliamp current to electrodes placed behind the subjects’ ears. Those electrodes deliver electricity through the skin to the vestibular nerve, which in turn sends signals to the brain that result in sensorimotor disturbances. Because the box is portable, subjects can carry it with them while attempting to walk – no doubt a big hit at the NSBRI’s office parties.

Moore tried his system out on 12 test subjects at the NASA Ames Research Center in Moffett Field, California. Each subject flew 16 simulated shuttle landings, half of those landings with the GVS and half without. He compared the results to data collected from over 100 shuttle landings. Subjects using the GVS, he concluded, experienced disturbances similar to those experienced by shuttle pilots on actual flights.

Without the GVS, subjects tended to land the shuttle at a simulated speed of 204 knots, which is right on target. With the GVS, the average speed increased to around 210 knots, which is at the upper limit of the safety zone. Likewise, GVS-using subjects also had more difficulty performing a routine landing approach braking maneuver that required them to bring the craft from a 20-degree glideslope angle to a 1.5-degree angle. This is a point in real shuttle flights at which pilots often experience sensorimotor disturbances.

Moore stated that his system could be used as an analog for other space vehicles and operations, and that it could even be used to prepare people with vestibular disorders for the effects following surgery. The NSBRI research team is now trying to determine if people can adapt to the effects of the GVS over multiple sessions.

New technology could prolong the life of medical implants

Researchers at the University of Louisville/Jewish Hospital's Cardiovascular Innovation Institute (CII) have discovered a method for preventing scar tissue from forming around implantation devices. This discovery could have a great impact on the functionality of common implanted devices, such as pacemakers, chemotherapy ports and glucose sensors. According to the study, if a unique system of blood vessels is created to interact with local tissue around an implanted device, better long term results can be achieved. The process involves “pre-vascularizing” a device prior to implantation, using what the team call a microvascular construct (MVC), which consists of blood vessels contained within a collagen gel. The idea is that a device will be coated in this gel prior to implantation. Since the body’s natural process is to find a foreign object and form a scar around it, this new study could prevent this problem from occurring.

"Scars have very little blood flow and because this connection between the body and the device is compromised, the function of the device over time can decline, threatening health and leading to additional interventions to replace it" stated Dr. Stuart Williams, scientific director of the CII and a senior investigator on the study.

In tests carried out on animals, the process was successful in providing an environment within the body that does not create scarring. "We found that the presence of the MVCs and collagen altered the way tissue formed around the implants, restricting the formation of scar tissue because there was so much blood vessel activity" Dr. Williams explained. He also added that "the presence of the MVCs and collagen also reduced the number of white blood cells that stimulate inflammation, where the device was implanted."

After the success of these tests, the next challenge for the CII team and Dr. Williams is to design a device that can be effectively used within operating rooms. Once this has been created, Dr. Williams will be able to bring his technology out of the lab and apply it to patients.