quinta-feira, 19 de junho de 2014

New manufacturing methods for 'soft' machines, robots


Purdue researchers have developed a technique to embed a liquid-alloy pattern inside a rubber-like polymer to form a network of sensors. The approach might be used to produce "soft machines" made of elastic materials and liquid metals for potential applications in robotics, medical devices and consumer electronics.

Researchers have developed a technique that might be used to produce "soft machines" made of elastic materials and liquid metals for potential applications in robotics, medical devices and consumer electronics.

Such an elastic technology could make possible robots that have sensory skin and stretchable garments that people might wear to interact with computers or for therapeutic purposes.

However, new manufacturing techniques must be developed before soft machines become commercially practical, said Rebecca Kramer, an assistant professor of mechanical engineering at Purdue University.

She and her students are working to develop the fabrication technique, which uses a custom-built 3D printer. Recent findings show how to use the technique to create devices called strain gauges, which are commonly found in many commercial applications to measure how much something is stretching.

The findings are detailed in a research paper appearing this week in the journal Advanced Functional Materials and is featured on the journal's inside front cover. The paper was authored by postdoctoral research associate J. William Boley; doctoral student Edward L. White; George T.C. Chiu, a professor of mechanical engineering; and Kramer.

The researchers embedded liquid-alloy devices into a rubber-like polymer called polydimethylsiloxane, or PDMS, a silicon-based "elastomer." The liquid gallium-indium alloy was used to create patterns of lines to form a network of sensors.

"It has some odd properties," Kramer said. "Gallium oxidizes really quickly and forms a thick gallium-oxide skin, which is challenging to work with using typical liquid-processing techniques."

However, the Purdue researchers have invented a method that takes advantage of the alloy's oxidized skin.

"We exploit this oxide skin by using it for structural stability. This means you can print liquid on a surface and it will maintain stable structures without moving around," she said. "Once you print it you can flip it over or turn it on its side, because the liquid is encased by this oxide skin. We use this finding to embed our electronics in elastomer without ruining or altering the printed structures during the processing steps."

Strain gauges measure how much a material stretches or deforms. Because conventional strain gauges are made of rigid metal film, they can't measure more than a 1-percent deformation before breaking, whereas a soft strain gauge could continue stretching with the material, measuring 100 percent of a material's strain.

"What's exciting about the soft strain gauge is that it can detect very high strains and can deform with almost any material," Kramer said. "The skin around your joints undergoes about 50 percent strain when you bend a limb, so if you wanted to have sensory skin and wearable technology that tracks your movement you need to employ soft, stretchable materials that won't restrict your natural range of motion."

Findings in the research paper describe how to use the 3D printer to create soft strain gauges.

"If you want to achieve a strain gauge device and you want the traces to be a certain width or height, we can tell you with our paper exactly what parameters you should choose, including the flow rate of the liquid, the speed of the stage, and the standoff distance of the nozzle from the substrate. We have created a design strategy for 3D printing liquid metals."

The research has shown that the liquid alloy does not readily adhere to the PDMS, whereas the oxide skin does. The findings may enable the researchers to increase this adhesion, a step that could help in the further development of the technique.

"Most sensors made from these materials are prototyped individually and limited to the millimeter-scale," said Kramer, who leads the team that created the prototype sensor. "Our process enables digital fabrication of the sensors on the micro-scale. While this is a huge step forward, we need to continue to decrease scale and increase density to develop sensors and electronics that are comparable to traditional, rigid devices and that mimic the functionality of human skin."

The new process also can be used to fabricate pressure sensors, capacitors and conductors. Previously, Kramer developed a hyperelastic tactile keypad using the same materials.

"It's a sensitive keypad that is flexible and wearable," she said. "When you push on the elastomer it will deform the underlying microchannels, changing the resistance across them."

Soft machines could make possible new types of soft microelectromechanical systems, or MEMS. Current MEMS such as miniature accelerometers and gyroscopes found in consumer electronics, automotive airbags and other products are made of solid metals. However, the development of soft MEMS could open up new applications.

'Smart glass' micro-iris for smartphone cameras

 

June 18, 2014

Institute of Physics

A small, low-powered camera component made from a 'smart glass' material has been created by a group of researchers in Germany with the hope of inspiring the next generation of smartphone cameras. The micro-iris is an electro-chemical equivalent to the bulky, mechanical blades that are usually found in cameras and has very low power consumption, making it an ideal component for a wide-range of camera-integrated consumer devices.


The micro-iris is an electro-chemical equivalent to the bulky, mechanical blades that are usually found in cameras and has very low power consumption, making it an ideal component for a wide-range of camera-integrated consumer devices.

The device and the first results of its performance have been presented in a study published today, 19 June, in IOP Publishing's Journal of Optics.

In the human eye, the iris controls the diameter of the pupil and subsequently the amount of light that reaches the retina. The purpose of an iris, or aperture stop, in a camera is exactly the same; it controls the amount of light that reaches a camera's sensors, which affects the overall focus of the image.

Traditionally, cameras have contained a set of overlapping blades that are mechanically moved to change the size of the hole -- or aperture -- through which light enters. However, with the rising popularity of small, compact and lightweight consumer devices that are integrated with cameras, it has been almost impossible to miniaturise these mechanical systems.

The researchers, from the University of Kaiserslautern, have proposed an alternative method using an electrochromic material. This material, which is often referred to as "smart glass," transforms from a transparent material into an opaque material when a small electrical voltage is applied to it.

In their study, the researchers fabricated a micro-iris using two glass substrates sandwiched together, and with each one carrying a thin film of electrochromic material, called PEDOT, on an underlying transparent electrode.

The micro-iris was 55 µm thick and could be switched into an opaque state using a current of 20 µA with a voltage of 1.5 V.

The micro-iris exhibited a memory effect and did not require a continuous current to maintain the opaque state, so its power consumption remained very small.

In addition to testing the intensity of light that passed through the micro-iris, as well as the amount of time it took to switch between different states, the researchers also examined the depth of focus that the micro-iris was able to impart in comparison to a traditional blade-based iris.

Lead author of the research Tobias Deutschmann said: "There is currently no technological solution available that meets all the demands of integrated iris apertures in smartphones.

"Many of the proposed devices require the motion of a strong absorbing material to block the path of light. Electrochromic materials, as used in this study, remain stationary whilst they change their absorption, so there is no need for any actuation. This allows for much smaller casings to fit around the devices and thus enables the integration into tiny camera systems”.

"We will now further investigate the potential of optimized electrochromic materials, with a particular focus on improving the optical contrast and, in particular, the control of the depth of focus -- this is the decisive hardware parameter which determines the success of next-generation models in the smart phone business."

Longer battery life, more memory in electronics? Rare materials perform at near-room temperature


New theoretical physics research reveals rare materials that possess both controllable magnetic and electric polarization properties at near-room temperatures.

The discovery could lead to longer battery life and increased memory storage for electronic devices, said Yurong Yang, a research assistant professor at the University of Arkansas.

An international team of physicists published its findings on May 28 in Nature Communications, an online journal published by the journal Nature, in a paper titled "Near room-temperature multiferroic materials with tunable ferromagnetic and electrical properties."

A rare class of materials known as multiferroics can change their electrical polarization when under a magnetic field or magnetic properties when under an electric field. But multiferroics usually exhibit these properties at temperatures far below room temperature, which makes them useless for every-day applications.

As a result, the materials used to power today's memory devices do so through electricity or magnetism, but not both.

The research team included Yang and Laurent Bellaiche, Distinguished Professor of physics at the University of Arkansas. Yang, a theoretical physicist, used computer modeling to perform extremely accurate calculations on a specific class of materials to find combinations that would display these properties.

The researchers found that a specific class of multiferroics, when periodically alternating along a specific direction to make what is called a superlattice, should exhibit both controllable magnetic and electrical polarization properties at near-room temperature, Yang said.

Superlattices are like multi-layered cakes, where the cake layers are only nanometers thick and are made of different materials such as the multiferroics studied in this paper. The next step will be experimental confirmation of their calculations.

Yang and Bellaiche both conduct research in the University of Arkansas' Institute for Nanoscience and Engineering and the department of physics. Bellaiche holds the Twenty-First Century Endowed Professorship in Nanotechnology and Science Education.

The results were obtained through a collaborative effort with Hong Jian Zhao, a former visiting graduate student at the University of Arkansas who is now completing his doctorate in the department of materials science and engineering at Zhejiang University in Hangzhou, China. Also collaborating on the study were Xiang Ming Chen, Zhao's adviser at Zhejiang University; Wei Ren at Shanghai University in China and Jorge Iniguez at the Materials Science Institute of Barcelona in Spain.

Horizontal levitation: The ultimate solution to particle separation

 

June 18, 2014

Springer Science+Business Media

Separating particles from the liquid they are in can now be done with a new concept. Magnetic separators exploit the difference in magnetic properties between minerals, for example when separating magnetite from quartz. But this exercise becomes considerably more complex when the particles are not magnetic. In the wake of previous particle levitation experiments under high-power magnetic fields, a new study reveals that particles are deflected away from the magnet's round-shaped bore center in a horizontal direction.


Magnetic separators exploit the difference in magnetic properties between minerals, for example when separating magnetite from quartz. But this exercise becomes considerably more complex when the particles are not magnetic. In the wake of previous particle levitation experiments under high-power magnetic fields, a new study reveals that particles are deflected away from the magnet's round-shaped bore centre in a horizontal direction. Previous studies had observed the vertical levitation of the particles. These findings are presented by Shixiao Liu from the Faculty of Engineering, University of Nottingham, UK and colleagues, in a paper recently published in EPJ E, and could led to a new concept in particles and minerals separation technologies.

The authors analysed video frames covering 0.1 second each of the movement of glass and pyrite particles of roughly one millimetre diameter in a solution that was subjected to a strong non-uniform magnetic field created by a superconducting magnet. The authors show that pyrite and glass particles were deflected and settled at certain positions in a specially designed container. They explain that this pattern is due to differences in the particles' densities and magnetic susceptibilities.

The gradient in the magnetic field gives rise to a radial force-defined by the particles' magnetic properties-capable of separating the glass from pyrite particles. At the same time, the magnetic field gradient also induces the so-called Magneto-Archimedes force, which compensates for the force of gravity. Surprisingly, the particle size seems to have little influence on the results, at least for the limited size range examined in these experiments.

The authors then confirmed their experimental findings using mathematical simulations of the particle displacement.

World Cup hotels: Where teams are staying in Brazil

 

 

All eyes are on Brazil this summer as the world's soccer teams descend on the South American country for the 2014 World Cup. Wonder where all those players are staying? Trivago.ca takes Sun Media inside 10 of the hotels the world's top soccer teams are staying at. From beachfront resorts to mountain retreats, check out these 10 gorgeous properties in our gallery.

England - Royal Tulip, Rio de Janeiro: The England squad will be making the Royal Tulip their home this summer – a stylish hotel located on the São Conrado beach in Rio de Janeiro. Fully equipped with an outdoor pool and stylish bar, the hotel certainly delivers on leisure activities, with two tennis courts, a gym and a sauna to help unwind after a tough match. (Courtesy Royal Tulip, Rio de Janeiro)

10 Reasons Why Rio de Janeiro is Awesome!

 

Posted in Featured, South America on February 10, 2014

Many times on my travels I have found there are cities that are hyped up to be something extra-ordinary, extra special, something spectacular, only to get there and feel disappointed because it just didn’t live up to the huge promotion it was given. I expected this to happen in Rio de Janeiro. I expected it not to be as good as I had imagined. I arrived in a bad mood thinking it wouldn’t be everything I wanted it to be. I was wrong. It was better than I imagined. I genuinely love this city and for that reason I thought I’d share with you 10 reasons why I think it’s awesome! I hope it makes you want to visit Rio if you haven’t visited already!

 

Breath-taking coastline

runaway jane in rio de janeiro

Usually I hate busy beaches. As a self confessed introvert on my travels I like my own space, and in particular I like empty or near-empty beaches. It’s only then I feel I can enjoy the sea views and the cusp of a wave to its full extent. However, even on an extremely busy weekend, walking along Rio de Janeiro’s most famous beaches – Copacabana and Ipanema - I couldn’t help but be over-awed by the stunning coastline landscape here. Particularly in the case of Ipanema (see me pictured at Ipanema beach above), despite the huge crowds of people you just couldn’t deny it was an incredible coastal view. You could definitely under stand the popularity and why these beaches are known the world over.

 

Well prepared for tourists

One of the things I was most impressed with in Rio was the strong presence at the International Airport and major tourist sites of tourist information points and people handing out free city maps. Particularly at the airport I think I passed around 3 separate tourist information desks, one of which you passed before you’d even collected your hold luggage. Something simple like this made it so much easier getting from the International Airport into town by bus and it was a small yet reassuring sign that Rio is ready for the World Cup in June despite its recent troubles.

 

Super friendly & sociable locals

I’ve only ever had good experiences when I’ve met Brazilian people on my travels around the world. They just seem to be friendly and sociable by nature and my time in Rio de Janeiro was no different. Every time I asked for help or directions people always seemed happy to help. When I was sitting in cafes on my own local people would just come up and talk to me even though I was a complete stranger. If there wasn’t enough seats in a restaurant people who’d never met each other before would just squeeze up next to one another and chat while they ate. Usually the big cities are the places where people can often be less friendly but I personally did not experience this in Rio de Janeiro. Genuinely, everyone was really nice to me. The place just had a cool vibe and I loved hanging out with the local people here.

 

Christ the Redeemer

christ the redeemer statue

It’s probably one of the few landmarks around the world that could rival the Eiffel Tower for fame - and you can see exactly why when you visit the ‘Christ the Redeemer’ statue in Rio de Janeiro. In actual fact, whilst the trip to view the statue up close was a worth while one-time experience in order to see it up close, in my opinion the statue is actually most impressive when viewed from afar around the city. For example, the views of ‘Christ the Redeemer’ from Botafogo – the neighbourhood where I was staying - were particularly impressive. They made what would have been a normal day shopping for example turn into something more inspiring when you see the statue in the distance (and I’m not even religious!)

açaí

Açaí is a non-alcoholic berry fruit drink that you drink/eat with a spoon. The Açaí Palm (the plant which the berries come from) is native to Central and South America but is particularly popular in Brazil. I personally had never heard of Açaí until I arrived in Rio and so it was therefore  a very welcome surprise! I actually think I got mildly addicted to the stuff while I was here, and considering how many juice bars there are in Rio, it was a good excuse to stop every so often and have a drink of Açaí when the hot summer weather here got too much.

 

Caipirinha

Rio de Janeiro is a party city. Even if you were like me and chose not to focus your activities here on partying so much, you can’t come to Rio and not taste a local Caiprinha in Brazil’s most famous city! A word of warning though – they do make them strong!

 

Brazilian Samba

Another popular activity to experience while you’re in Rio is to take some Samba lessons. You also may want to go see a Samba show. I personally recommend doing both, but I think you’ll also be hard pressed to find a Samba show in Rio de Janeiro that isn’t also a tourist trap. Not that there’s anything wrong with that as long as it’s fun and you have a good time, but personally I think for a more authentic experience it’s better to go learn a bit of the dance with a local qualified instructor followed by a trip to a samba club. You’ll find many of the hostels in Rio offer lessons in house or can arrange them for you (which is what I did in Rio as I had limited time to shop around), but I also heard good things about ‘Rio Samba Dancer’ school, a local company who offer group lessons to tourists.

 

Lagoa Rodrigo de Freitas

lagao rodrigo de freitas rio de janeiro 

For me the Rodrigo de Freitas lake was one of the major visual highlights of Rio de Janeiro. A) Because the lake itself it very tranquil and beautiful, and B) because of the great views of the ‘Christ the Redeemer’ statue from the lake side. It’s the best place in my opinion to view Rio’s iconic statue from afar, but it’s also just a really nice place to visit on its own if you’re chilling out on a sunny day or want to go for a bike ride. You’ll also meet a lot of local people here on weekends out cycling or having lunch with their family.

 

Pão de Açúcar Cable Car

Again, another great spot for epic views of Rio de Janiero! The Pão de Açúcar is a double cliff/mountain top and cable car situated on the coast in between Rio’s Botafogo neighbourhood and Copacabana. There are two cable cars that take you to both cliff tops and allow you some stunning views of the city. There is also more room to move than you’ll find when you go to visit the Christ Redeemer statue, so may allow you some better photos of the city. However, this attraction is also rather pricey at 60 Brazilian Reals for 1 adult - more than what it will cost you for much more famous attractions in the city! Still, the views are incredible.

 

Sunshine Weather

Rio de Janeiro Brazil

Rio never really gets cold. Certainly not by Northern European standards where I come from. When I was there a few weeks ago most days were around the 30 ºC mark, but on a particularly hot summer day it can reach as high as 40 ºC. In winter the weather here is usually around 20 ºC to 25 ºC (what an average summer would be like for me in Scotland!) Although you can find it dips down to as low as 15 ºC on a ‘cold’ winter day here. Essentially Rio has the perfect climate for a visit any time of year.

- I really loved Rio de Janeiro during my time here. I remember arriving in Rio feeling a little down and in a bit of a bluesy mood only to immediately feel much more cheery and uplifted as soon as I stepped out into the city. It’s just one of those places that has that kind of affect on you. It’s beautiful, sunny, there’s lots to do and the local people are friendly. The only thing I wished for was that I had more time here. It’s certainly on my agenda to make a return visit here at some point in the future. It really is an awesome city!

Yoga exercise program tailored for pulmonary hypertension patients


A first-of-its-kind yoga exercise program has been developed by Henry Ford Hospital for patients living with pulmonary hypertension, a chronic lung disease that afflicts women at least two times more than men.

Called Yoga for PH, the 40-minute program includes three yoga exercise levels and a nutrition and lifestyle discussion. It is available for free download on iTunes and Googleplay.

The program was developed by Henry Ford pulmonologist Rana Awdish, M.D. , a 20-year yoga practitioner.

"These yoga exercises are modified specifically for the needs of pulmonary hypertension patients and can be done safely regardless of the patient's level of physical fitness," Dr. Awdish says. "We all recognize the importance of exercise. But for these patients, routine activities like walking up stairs can be challenging, so convincing them they can have success exercising can be challenging.”

"What we've created are a series of gentle, low-impact exercises that can be in the comfort of their own home, sitting in a chair or standing. These are designed to improve balance, strength, reduce stress and calm the nervous system. Even patients who require oxygen can perform these exercises."

Henry Ford Hospital is among the largest referral centers for pulmonary hypertension in the United States, and is one of only two hospitals in Michigan that offer pulmonary and critical care medicine fellowship programs. The hospital has an intensive care unit dedicated to the care of pulmonary hypertension patients, with specially-trained nurses who are experts in managing the complex needs of these patients.

Dr. Awdish says the idea for a yoga exercise program was borne from requests from patients. It was funded by a grant from the Pulmonary Hypertension Association.

"The interest was all organic," she says, "and the patients wanted to know how to do yoga safely, despite their condition."

Pulmonary hypertension, or PH, is high blood pressure in the lungs. The blood vessels in the lungs become narrowed and the heart has to work harder to pump blood through them. It typically develops between the ages of 20 and 60, and is two or three times more common in women than men.

Common symptoms are shortness of breath, fatigue, chest pain and a racing heartbeat. As PH worsens, symptoms may limit physical activity.

While PH has no cure, the earlier the disease is treated, the better the outcomes are for patients. Treatment options to relieve symptoms and slow the progression of the disease include medication, surgical procedures and lifestyle changes. "With proper medication," Dr. Awdish says, "patients can live a long and healthy life."

"Any amount of exercise is beneficial is patients," she says. "We know that when patients are engaged in their treatment and their healing, they have better outcomes. These yoga exercises will help aid their healing process."

Hippocampal activity during music listening exposes the memory-boosting power of music

June 18, 2014

Suomen Akatemia (Academy of Finland)

For the first time the hippocampus —- a brain structure crucial for creating long-lasting memories —- has been observed to be active in response to recurring musical phrases while listening to music. Thus, the hippocampal involvement in long-term memory may be less specific than previously thought, indicating that short and long-term memory processes may depend on each other after all.


Activity in an area (in red) within the hippocampus (in green) increased when musical motifs in the piece were repeated.

For the first time the hippocampus -- a brain structure crucial for creating long-lasting memories -- has been observed to be active in response to recurring musical phrases while listening to music. Thus, the hippocampal involvement in long-term memory may be less specific than previously thought, indicating that short and long-term memory processes may depend on each other after all.

The study was conducted at the University of Jyväskylä and the AMI Center of Aalto University, by a group of researchers led by Academy Professor Petri Toiviainen, the Finnish Centre for Interdisciplinary Music Research (CIMR) at the University of Jyväskylä, and Dr. Elvira Brattico, Aalto University and the University of Helsinki. Results of the study were published in Cortex, a journal devoted to the study of the nervous system and behaviour.

"Our study basically shows an increase of activity in the medial temporal lobe areas -- best known for being essential for long term memory -- when musical motifs in the piece were repeated. This means that the lobe areas are engaged in the short-term recognition of musical phrases," explains Iballa Burunat, the leading author of the study. Dr. Brattico adds: "Importantly, this hadn't been observed before in music neuroscience."

A fundamental highlight of the study is the use of a setting that is more natural than those traditionally employed in neuroscience: the participants' only task was to attentively listen to an Argentinian tango from beginning to end. This kind of music provides well-defined, salient musical motifs that are easy to follow. They can be used to study recognition processes in the brain without having to resort to sound created in a lab. By using this more realistic approach, the researchers were able to identify brain areas involved in motif tracking without having to rely on the participants' ability to self-report, which would have constrained the study of brain processes.

"We think that our novel method allowed us to uncover this phenomenon. In other words, the identified areas may also be related to the formation of a more permanent memory trace of a musical piece, enabled precisely by the very use of a real-life stimulus (the recording of a live performance) in a realistic situation where participants just listen to the music as their brain responses are recorded," Iballa Burunat goes on to explain. Listening to the music from beginning to end may have imprinted the participants with a long lasting memory of the tune. This might not be expected were the participants exposed to a simpler stimulus in controlled conditions, as is the case in most studies in music and memory.

Although a real-life setting may be sufficient to trigger the involvement of the hippocampus, another explanation could lie in music's capacity to elicit emotions. "We cannot ignore music's emotional power which is thought to be crucial for the mnemonic power of music as to how and what we remember. There is evidence on the robust integration of music, memory and emotion -- take for instance autobiographical memories. So it wouldn't be surprising that the emotional content of the music may well have been a factor in triggering these limbic responses," she continues. This makes sense, since the chosen musical piece by Astor Piazzolla was a tribute to his father after his sudden death, and so the main purpose of the piece was to be of a deeply emotional nature."

Certainly, the hippocampus -- as part of the limbic system -- is connected to neural circuitry involved in emotional behavior, and ongoing research suggests that emotional events seem to be more memorable than neutral ones. The authors emphasize that these results should motivate similar approaches to study verbal or visual short term memory by tracking the themes or repetitive structures of a given stimulus. Moreover, the study has implications for neurodegenerative diseases associated with hippocampal atrophy, like Alzheimer's. "Music may positively affect patients if used wisely to stimulate their hippocampi, and thus their memory system," Academy Professor Petri Toiviainen indicates. A better understanding of the link between music and memory could have widespread repercussions, leading to novel interventions to rehabilitate or improve the life quality of patients with neurodegenerative conditions.

The study was supported by the Academy of Finland.

Race a factor in mortality in heart attack patients on anti-clotting drug

 

These variants increased patients' risk of dying in the year following a first heart attack, but they appeared to do so for different reasons depending on race, according to a study at Washington University School of Medicine in St. Louis.

In particular, the team found that two DNA variants common in African Americans were associated with an increased risk of both bleeding and death. In Caucasians, a different variant was linked to additional heart attacks and a higher risk of death.

The research is published June 17 in the American Heart Association journal Circulation: Cardiovascular Genetics.

The variations influence the way people metabolize clopidogrel and can alter its effectiveness. The blood-thinning drug commonly is prescribed after a heart attack to reduce the likelihood of another heart attack or a stroke.

"The research is provocative," said the study's first author, cardiologist Sharon Cresci, MD, assistant professor of medicine and of genetics. "Knowing about potential genetic differences based on race can help physicians tailor drugs to patients based on their genetic makeup."

Clopidogrel is metabolized in the liver, where it is turned into its active form via a group of enzymes called cytochrome P450, or CYP for short. Although clopidogrel is effective in many patients, earlier studies determined that some people metabolize the drug better than others.

Indeed, in 2010, the Food and Drug Administration added a "black box" warning to labels of clopidogrel after research that primarily involved Caucasians showed that people with a particular CYP genetic variant metabolized the drug poorly, which reduced the amount of the drug circulating in the blood. These patients had a higher risk of heart attack and stroke.

Additional studies showed that other CYP gene variants are linked to the rapid metabolism of clopidogrel and that patients with those variants had a higher risk of bleeding.

But it has not been clear until now that the effects of these particular gene variations can vary by race in patients taking clopidogrel after a heart attack.

For the study, the researchers analyzed CYP variants among 2,062 Caucasians and 670 African Americans who suffered heart attacks. Nearly 80 percent of the Caucasians and 65 percent of the African Americans were prescribed clopidogrel. The patients were enrolled in a major study known as TRIUMPH (Translational Research Investigating Underlying disparities in acute Myocardial infarction Patients' Health) conducted from 2005 to 2008 at 24 U.S. hospitals, including Barnes-Jewish Hospital in St. Louis.

Among patients taking clopidogrel, the one-year mortality rate for African Americans was 7.2 percent, compared with 3.6 percent for Caucasians.

Caucasians who carried the CYP2C19*2 variant, which has been linked to poor metabolism of the drug, had a higher rate of repeat heart attacks and death. The higher rate of heart attacks is consistent with the slower metabolism of clopidogrel.

However, among African Americans treated with clopidogrel, the CYP2C19*2 variant was not associated with a higher rate of death.

Rather, African Americans had higher rates of bleeding and death if they carried either of two other variants: CYP1A2*1C or CYP2C19*17, the latter of which has been associated with the rapid metabolism of clopidogrel. Among Caucasians on clopidogrel, neither variant increased the risk of death.

"This is very novel information that begs for more research," said cardiologist Richard G. Bach, MD, the study's senior author and an associate professor of medicine at Washington University.

Although genetic testing is available to identify CYP variants in a patient's DNA, these tests generally are not widely used by cardiologists. Results of the current study suggest this practice may need to be reconsidered.

"This research is an important addition to the field because previous studies looking at CYP gene variants and their effects on risks of repeat heart attacks, bleeding and death have included predominantly Caucasian patients of European ancestry," Cresci noted. "There is almost no data, until now, about these variants in African Americans."

Research examining how genetic variants alter the effectiveness of clopidogrel remains somewhat controversial, Bach said. Many physicians feel that before they can tailor medical therapy for heart attack patients, more data is needed to prove there is a clear link between genetic variants and negative health consequences and that tailoring therapy will improve patients' outcomes, he explained.

His hope is that additional research would provide more definitive conclusions to help physicians choose the best medications for patients after a heart attack and, ultimately, "to reduce the too-high rate of death and disability for patients after a heart attack," Bach said.

Cresci agreed, adding: "By focusing on genetic differences, we may be able to individualize therapies after heart attacks and achieve the best treatment for each patient."

Food poisoning cases underreported, food safety specialist says

 

June 18, 2014

Kansas State University

There are distinct symptoms for food poisoning and reporting it to your doctor is an important step in improving food safety, a food safety specialist says. According to the Centers for Disease Control and Prevention, 19,056 cases of infection were reported in 2013 in the United States. However, it is expected that many people don't report getting sick from contaminated food because they don't realize they have food poisoning.


You've probably heard of norovirus, salmonella and E. coli, but would you know if you were sick with one of these foodborne illnesses? A Kansas State University food safety specialist says there are distinct symptoms for food poisoning and reporting them to your doctor is an important step in improving food safety.

"We really want to reduce the number of foodborne illness outbreaks," said Karen Blakeslee, extension specialist in food science and coordinator of the Rapid Response Center. "It's important to understand foodborne illness and its symptoms because the whole topic of foodborne illness is really underreported."

According to the Centers for Disease Control and Prevention, 19,056 cases of infection were reported in 2013. However, Blakeslee says many people don't report getting sick from contaminated food because they don't realize they have food poisoning. Symptoms of a foodborne illness are similar to those with other illnesses, such as vomiting, diarrhea, headache and fever, but there are some distinct symptoms of foodborne illness.

"Symptoms like double vision, dizziness, lethargy and dehydration are all symptoms specific to a foodborne illness," said Blakeslee.

It takes two or more people with similar symptoms to be considered a foodborne illness outbreak. Blakeslee says another challenge with decreasing the number of outbreaks is trying to determine the food that was contaminated.

"It's not necessarily what you ate that day or the day before," she said. "Some of the symptoms for the different kinds of bacteria may take up to a couple of weeks to occur, so that's why it makes it really hard to identify the cause of the outbreak."

If you do suspect you have food poisoning, Blakeslee says to see a doctor or call your local health department.