No cubo representado a seguir, cuja aresta mede 12 cm, qual a distância, em cm, do plano que passa pelos vértices
AFC ao vértice D?
Leia a tirinha a seguir.
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CAN ADDICTION TO SMARTPHONES TRIGGER ADHD?
We measured inattentiveness and hyperactivity by asking participants to identify how frequently they had experienced 18 symptoms of ADHD over each of the two weeks. These items were based on the criteria for diagnosing ADHD in adults as specified by the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders. The results were clear: More frequent phone interruptions made people less attentive and more hyperactive. These findings should concern us. Smartphones are the fastest-selling electronic gadget in history—in the 22 seconds it took to type this sentence, 1,000 smartphones were shipped to their new owners. Even if one of those 1,000 users became more likely to make a careless mistake, ignore a friend in the middle of a conversation or space out during a meeting, smartphones could be harming the productivity, relationships and well-being of millions.
As with all disorders, symptoms of ADHD form a continuum, from the normal to the pathological. Our findings suggest that our incessant digital stimulation is contributing to an increasingly problematic deficit of attention in modern society.
So consider silencing your phone, even when you are not in the movie theater. Your brain will thank you.
www.newswekk.com/can-459362
Leia o texto a seguir.
Scientists invent silk food wrap that's biodegradable and could replace plastic cling film
Bananas and strawberries kept at room temperature for more than a week did not go off after they were coated with a near-invisible film made from silk
Ian Johnston
Scientists have invented a cling film-like food wrap made from silk that can preserve fruit for more than a week, as a natural, biodegradable alternative to plastic.
International concern has been growing about plastic waste, particularly the amount that gets into the sea. One estimate is that by 2050 there will be more plastic than fish in the world's oceans.
Doctors have also warned that containers made from certain kinds of plastic could be harmful to health.
Now a team of biomedical engineers at Tufts University in the US have developed a technique that enables food to be coated with an almost invisible layer of fibroin, a protein found in silk, which helps make it one of nature's toughest materials.
The lead researcher, Professor Fiorenzo Omenetto, told The Independent that the world should probably move "towards processes that are more efficient and more naturally derived" and develop materials that "are closer to the things that surround us, rather than having more man-made, processed materials ... for the general well-being of our planet".
"It's a wise way of thinking about how we manage the resources of our planet, to maybe use renewable systems as opposed to non-renewable systems," he said.
"The pervasiveness of plastic and all the inorganic chemicals that leach out, albeit at very slow rates, can affect us in many ways."
When asked what the chances were that silk-derived products would replace plastics, Professor Omenetto said: "That's our dream."
However he said the use of plastic was widespread and "incredibly cost effective" so it might take some time to convince people to change.
The same team previously made a silk cup that could be used, at least once, for coffee as a possible replacement for plasticlined cardboard cups.
In a paper in the journal Scientific Reports, they described how strawberries and bananas could be preserved for a week or more.
The fruit is coated by dipping it in a liquid containing a tiny amount of fibroin, but the wrap could also be applied with a spray. The silk is produced naturally by worms of moths.
Strawberries left for seven days at room temperature became discoloured and went soft, but those coated with the silk protein stayed juicy and firm.
Available in: http://www.independent.co.uk/news/science/silk-plastic-cling-film-food-wrap-marine-pollution-food-fruit-vegetables-tufts-universityfiorenzo-a7017401.html. Access on: May 2016.
Leia o texto a seguir.
WHAT MAKES US HELP OTHERS? WHAT MAKES US SELFISH?
Kitty (Catherine) Genovese was a 28-year-old New York City woman stabbed to death near her home in the Kew Gardens section of Queens, New York, in 1964. It took her about a half-hour to die, as she crawled on the streets shouting for help. At the time, newspapers reported that over three dozen people saw or heard her crying for help after she was stabbed, but they did nothing. Instead of calling the police, they closed their windows. They did not want to get involved. No one called until the final assault, each of them perhaps thinking that someone else would do it. Eventually, someone did call, but it was too late. Later reports cast doubt on the complete accuracy of the original New York Times story about the incident. That story was based on the initial police report. The number of witnesses who heard the screams may have been closer to a dozen, and the number who actually saw something may be a half-dozen. Still, a half-dozen did not respond, and the incident became a symbol of the alienation of the big city. Sadly, news reports are filled with stories about ordinary humans acting inhumanely as apathetic bystanders. Search for “people ignore man dying on street” in Google, and you will get thousands of results.
www.newswekk.com/can-459362
Assinale a alternativa CORRETA de acordo com o texto.
I. O título do texto sintetiza o caso de morte súbita relatado no texto.
II. Muitos medicamentos utilizados para combater o câncer não funcionam.
III. A busca de informações sobre doenças na internet é indicada.
IV. O câncer mencionado no texto apareceu na região da garganta da paciente.
V. O subtítulo do texto visa chamar a atenção para o uso de um medicamento que tem demonstrado proporcionar resultados promissores.
Leia o texto a seguir.
LEARNING FROM THE LAZARUS EFFECT
Most clinical trials for cancer drugs are failures. But for a handful of patients, a drug proves to be nearly a cure. What can science learn from these “exceptional responders”?
For years, Grace Silva had experienced odd episodes with her throat — bouts of swelling and radiating pain that seemed to resolve with antibiotics — but her doctors couldn’t explain what was wrong. Finally, after a flare-up in the summer of 2010, Grace was referred to a specialist, an ear doctor who felt something amiss on the left side of her throat: a lump. The Silva family agreed that it was time to get Grace, then 54, to a thyroid specialist. Grace’s daughter Melanie tracked down the name of one at Brigham and Women’s Hospital, a 90-minute drive from Grace’s brown clapboard split-level near New Bedford, Mass. In September 2010, the specialist delivered the diagnosis: anaplastic thyroid cancer. It was bad, he warned her, and she would need surgery. Grace’s other daughter, Karrie, was marrying in a few weeks. “Can’t it wait?” Grace asked. It could not. “And whatever you do,” the specialist said, “please don’t look it up on the Internet.”
www.nytimes.com/2016/05/15/magazine/exceptional-responders-cancer-the-lazures-effect.html
O ácido sulfúrico é uma das substâncias mais conhecidas da Química, suas aplicações são diversas, pois este ácido é o mais utilizado na indústria e devido a isso ele serve como um medidor de índice industrial de um país, pois quanto mais há consumo desta substância, mais desenvolvida é a indústria local. O fator negativo dessa grande utilização é o agravamento dos processos de chuva ácida devido a uma maior liberação de compostos de enxofre. A seguir, estão listadas algumas das suas aplicações.
• Produção de ácido fosfórico.
• Refinaria de petróleo.
• Baterias automotivas.
• Fabricação de fertilizantes transformando alguns componentes insolúveis em solúveis.
• Fabricação de explosivos.
• Fabricação de tintas e papel.
Fonte: <http://www.infoescola.com/quimica/acido-sulfurico/>
As unidades de concentração podem ser expressas de diferentes formas. Usualmente utilizamos a concentração comum e o título na maioria dos produtos alimentícios e farmacêuticos. Os cálculos químicos estequimétricos, porém, levam em consideração, preferencialmente, a molaridade.
A água oxigenada, por exemplo, tem sua concentração analisada por uma porcentagem ou pelo volume de oxigênio molecular produzido pela decomposição do peróxido de hidrogênio. Considere a análise de uma solução aquosa com 6 % em massa de peróxido de hidrogênio. A concentração aproximada dessa solução expressa em volume de gás oxigênio formado nas CNTP é de
- Volume molar nas CNPT = 22,4 L.
- Considere que 1 litro de água oxigenada libera 10 litros de gás oxigênio (O2), dessa forma, 10 litros de oxigênio é 10 vezes o volume de 1 litro de água oxigenada, por isso ela é chamada de 10 volumes.
- Considere também que a densidade da água oxigenada em questão é de 1 g.cm-3 .
Leia o texto a seguir.
As doenças cardiovasculares são responsáveis por 29,4% de todas as mortes registradas no País em um ano. Isso significa que mais de 308 mil pessoas faleceram principalmente de infarto e acidente vascular cerebral (AVC). As doenças cardiovasculares são aquelas que afetam o coração e as artérias, como os já citados infarto e acidente vascular cerebral, e também arritmias cardíacas, isquemias ou anginas. A principal característica das doenças cardiovasculares é a presença da aterosclerose, acúmulo de placas de gorduras nas artérias ao longo dos anos que impede a passagem do sangue.
Fonte: http://www.brasil.gov.br/saude/2011/09/doencas-cardiovasculares-causam-quase-30-das-mortes-no-pais - Acesso: 04 de maio de 2016
O ácido acetil salicílico é um dos mais importantes medicamentos conhecidos. Sua utilização pelo homem data do Egito Antigo e sua popularização se deu a partir da síntese proposta pelo químico alemão Felix Hoffmann, funcionário de um importante laboratório alemão, precursor da atual gigante farmacêutica conhecida como Bayer. O ácido salicílico é uma substância natural, mas que é produzida artificialmente para atender a alta demanda industrial. Sua estrutura é apresentada a seguir.
Em relação à síntese dessa substância, no que diz respeito às reações de substituição no anel aromático que devem
ter ocorrido em sua preparação, percebe-se que, partindo do benzeno puro,
Observe a figura
A duração de um ciclo menstrual é, em média, de 28 dias. Convencionou-se designar o primeiro dia da menstruação
como o primeiro dia do ciclo. A regulação do ciclo depende de hormônios gonadotróficos ( FSH e LH) e de hormônios
esteroides (estrógeno e progesterona). É possível identificar nos gráficos a seguir dois ciclos femininos integrados: o
ovariano e o uterino.
Leia o texto a seguir.
Brasileiros descobrem mudança genética ligada ao câncer
Diagnóstico precoce da mutação permite prevenção e tratamento mais efetivos
Uma mutação genética que favorece o aparecimento do câncer de mama foi descoberta por pesquisadores do Instituto Fernandes Figueira (IFF/Fiocruz). Dois genes estão comprovadamente relacionados ao câncer de mama: o brca1, no cromossomo 13, e o brca2, no cromossomo 17 (eles foram batizados em função do nome em inglês da doença -- breast cancer ). Ambos são supressores de multiplicação celular, ou seja, contêm informações para sintetizar proteínas que bloqueiam a reprodução das células.
As células humanas contêm duas cópias de cada gene, chamadas de alelos. Para que o câncer de mama apareça, as duas cópias do gene brca1 ou do brca2 devem apresentar mutação. Mesmo que uma mulher nasça com apenas um dos alelos alterado, ela corre o risco de desenvolver a doença, pois a outra cópia pode sofrer mutação pela ação de fatores ambientais, como consumo de álcool, nicotina ou outras substâncias cancerígenas.
Fonte: http://cienciahoje.uol.com.br/noticias/medicina-e-saude/brasileiros-descobrem-mudanca-genetica-ligada-ao/?searchterm=genetica Acesso: 02 de maio de 2016.
Read the text.
Amazon keeps expanding its empire
Elizabeth Weise
Amazon has doubled the number of air freight cargo planes it is leasing, a further build out of its internal delivery system.
Atlas Air Worldwide on Thursday said it had signed an agreement with the Seattle internet retailer to operate 20 Boeing 767 for the company for ten years.
Operations under the agreements are expected to begin in the second half of 2016 and ramp up to full service through 2018, Atlas said.
In addition, Amazon will acquire as much as 20% of Atlas.
The planes will be used to move packages between Amazon’s fulfillment centers, which package goods, to its sortation centers, which sort them into local delivery pallets that can be taken to the Post Office for bulk delivery, the company said.
The planes will also be used by Amazon to move goods between its fulfillment centers across the country to other centers where they are needed for one- and two-day delivery, as no one Amazon center can stock the 20 million items Amazon typically has available for two-day delivery.
The deal isn't surprising, said John Haber, CEO of Spend Management Experts, a supply chain management consulting firm.
“This is just the most recent step in Amazon building out a massive logistics network designed to move more of their transportation and distribution under their direct control," he said.
Available in:<http://www.usatoday.com/story/tech/2016/05/06/amazon-further-builds-out-air-freight-network/84035574/>
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