Pele artificial

HEALTH AND WELLBEING

Scientists create artificial skin that stretches like the real thing

By Ben Coxworth

16:27 April 28, 2010

The University of Granada's fibrin-agarose artificial skin

Scientists at Spain’s University of Granada have created artificial skin with the resistance, firmness and elasticity of real skin. It is the first time artificial skin has been created from fibrin-agarose biomaterial. Fibrin is a protein involved in the clotting of the blood, while agarose is a sugar obtained from seaweed, commonly used to create gels in laboratories. The new material could be used in the treatment of skin problems, and could also replace test animals in dermatological labs.

The researchers started by obtaining plasma samples from human donors, and separating out the fibrin. They then added calcium chloride, to precipitate coagulation, tranexamic acid, to keep the coagulate from breaking down, and 0.1% agarose. The resultant material was grafted onto the backs of hairless mice, where its bio-compatibility with living organisms could be observed.

The mice showed no signs of rejection or infection, and healing of the grafted area began within six days - within 20 days, the wounds were fully healed.

Previously, artificial skin has been made from biomaterials such as collagen, polyglycolic acid, and chitosan. The fibrin-agarose skin, however, looks particularly promising. Prof. Jiménez Rodríguez, one of the researchers, stated "Definitively, we have created a more stable skin with similar functionality to normal human skin."

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Beyonce & Jay-Z

Ciência em português

por Sandra Pereira, Publicado em 05 de Abril de 2010

A encriptação de dados actual baseia-se em algoritmos quânticos, num código. No caos, a mensagem transmite-se pelo ruído na fibra óptica

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Esqueça o código, chegou o caos

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+ fotogalería

Se o bater de asas de uma borboleta no Brasil pode gerar um tornado no Texas, emitir uma mensagem no meio do caos também pode baralhar as pistas de um hacker. Com este pensamento baseado na teoria do caos, ou no "efeito borboleta" do meteorologista Edward Lorenz, Bruno Romeira, investigador na Universidade do Algarve, descobriu como tirar partido do caos para codificar dados na fibra óptica. Em teoria, pelo menos. O prémio de 12500 euros do programa Estímulo à Criatividade 2009 da Fundação Calouste Gulbenkian pode ajudar a criar um protótipo. Com o fenómeno do "phishing" (ataque informático para obter dados confidenciais) a crescer na internet, empresas e governos não olham a meios para proteger informações sigilosas.

É aqui que o sistema de Bruno Romeira pode fazer a diferença face aos actuais softwares de encriptação baseados em algoritmos (quânticos). No modelo de Romeira, há um emissor que emite sinais caóticos ao longo da fibra óptica para um receptor - que pode ser um computador em casa ou no escritório. Se um hacker quiser decifrar a mensagem secreta, terá de sincronizar emissor e receptor, já que neste sistema não há código--chave. A mensagem está dentro do ruído. E é indecifrável. As técnicas de sincronização estão ainda a ser apuradas por Bruno Romeira.

Este sistema "é mais complicado, mas é estável e garante mais confidencialidade do que os quânticos", explica o investigador de 27 anos. As vantagens da encriptação caótica são promissoras: "Tem menos componentes, baixo consumo de energia e é mais barata". "Se correr bem, poderá ser implementado nos escritórios", acrescenta Romeira, que está a trabalhar com a fabricante alemã Siemens.

Bruno Romeira imagina o seu futuro na liderança de um laboratório português. Não acredita que a fuga de cérebros dure para sempre. "Lá fora, é mais fácil obter financiamento, mas em Portugal começam a existir centros de investigação que contratam". O cientista traça um retrato optimista da investigação nacional: "Estamos cada vez mais equipados com massa crítica e começamos a atrair investigadores do exterior. Portugal está a começar a reunir condições para poder avançar na ciência".

E qual é o passo que falta dar para os portugueses se afirmarem? "Passar o potencial académico para as empresas e transformá-lo em produtividade", responde Romeira, acrescentando que o país devia apostar na propriedade intelectual. Quando a encriptação caótica funcionar na perfeição, o jovem promete não deixar escapar a patente.

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Mistério?

Bureau of Meteorology images show mysterious patterns on radar system

One of the radar images that show mysterious patterns. Image: Bureau of Meteorology Source: Supplied

One of the radar images that show mysterious patterns. Image: Bureau of Meteorology Source: Supplied

One of the radar images that show mysterious patterns. Image: Bureau of Meteorology Source: Supplied

THEY are the digital-age equivalent of crop circles - mysterious patterns appearing on the Bureau of Meteorology's national radar system without any explanation.

And the random images described as red stars, rings of fire and white doughnuts are sending online conspiracy websites into meltdown.

The anomalies first began on January 15 when an "iced doughnut" appeared over Kalgoorlie in WA.

Interference or something else? Tell us in the comment box below.

Satellite imagery showed there was no cloud over the area at the time to explain the unusual phenomenon but farmers' online comments claimed it was "unusually hot" all day.

It was followed by a bizarre red star over Broome on January 22 and a sinister spiral burst over Melbourne described by amateur radar buffs as the Ring Of Fire Fault.

The Bureau, which did not respond to repeated requests for comment, has acknowledged the anomalies on its popular website.

It has since posted a disclaimer above the national loop feed putting the images down to "occasional interference to the radar data".

"The Bureau is currently investigating ways to reduce these interferences," the disclaimer said.

Conspiracy websites, however, have lit up with dozens of breathless theories behind the strange anomalies from alien involvement, secret military testing to government weather modification.

One theory gaining traction online is the belief the US military has expanded its High Frequency Active Auroral Research Program.

Based at a remote research station in Alaska, the HAARP project involves shooting extremely high frequency radar bursts into the upper reaches of the atmosphere to see what happens after particles of the ionosphere are temporarily excited.

Ostensibly the research is to study the effects of solar flares on radio communications and improve missile detection and navigation systems.

But, unlike the failed cloud seeding experiments of yesteryear, conspiracy theorists claim HAARP is engaged in a sophisticated form of weather modification and that testing is also being done from a secret facility near Exmouth in Western Australia.

UK electrical engineer and crop circle expert Colin Andrews said Australians deserve an explanation.

"Until [the Bureau of Meteorology] make a formal and complete response to all the various strange patterns, one can only speculate about what is taking place," he said.

Mr Andrews urged people concerned by the bizarre radar symbols and strange weather patterns to contact the Bureau of Meteorology or a government representative.

Another theory suggests the anomalies appear before major weather events such as cyclones Olga and Paul and the violent storms which hit Victoria in recent weeks.

Others argue objects in the atmosphere emitting powerful radiation could be behind the mystery.

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