| No vaccine or medication can protect you from E. coli-based illness, though researchers are investigating potential vaccines. To reduce your chance of being exposed to E. coli, avoid risky foods and watch out for cross-contamination. Risky foods
Avoid cross-contamination
http://www.mayoclinic.org/diseases-conditions/e-coli/basics/prevention/con-20032105 |
Posted: 04 Nov 2015 09:00 AM PST
Yohan Terraza est un photographe français qui présente aujourd’hui une série en cours de photographies de nuit, débutée il y a quelques années. Basé en partie sur une histoire personnelle, ce travail a été réalisé en Gironde, en montagne et sur des dunes de sable. Ce photographe a voulu donner sa propre perception de la nuit : un ballet qui se renouvelle à l’abri du Soleil, fait d’entractes, de silences, de chemins, d’espoirs et de tourments.
Posted: 05 Nov 2015 11:00 AM PST
Leroy Bellet est un jeune photographe australien. Dans ses clichés époustouflants, il immortalise les surfeurs dans la pratique de leur sport. Le jeune artiste photographie les sportifs lorsqu’ils sont au coeur de la vague. Les images qu’il nous offre nous plongent en immersion dans ce que perçoivent les surfeurs lorsqu’ils sont sur l’eau.
| El parque marino Nazca-Desventuradas abarcará una superficie de 297.000 km2, convirtiéndose en el más grande de Latinoamérica. Por Lorena Guzmán H. 4 de noviembre de 2015 Para 2020, el 10% de los mares del mundo deberían estar bajo protección o por lo menos esa es la meta de las Naciones Unidas. No obstante, actualmente las zonas con algún grado de control solo llegan al 3,5%, mientras que las que se encuentran con protección total apenas suman el 1.6%. Aún así, cada avance cuenta y Chile acaba de dar uno que podría inspirar a otros. Durante la segunda reunión internacional Nuestro Océano –realizada en el puerto chileno de Valparaíso a principios de octubre pasado– la presidenta de Chile, Michelle Bachelet, no solo inauguró la cita, sino que también anunció tres nuevas zonas de protección marinas en territorio chileno. Estas “conllevarán la protección de una superficie total de más de un millón de kilómetros cuadrados, constituyéndose en su conjunto en uno de los espacios de protección marina más grandes del mundo”, aseguró la mandataria. El parque marino Nazca-Desventuradas abarcará una superficie de 297.000 km2, convirtiéndose en el más grande de Latinoamérica; a él se suma una red de áreas protegidas en el archipiélago Juan Fernández que mantendrá bajo protección a 13.000 km2. Por último, está la propuesta de crear una inmensa zona protegida de unos 720.000 km2 en Rapa Nui, (o Isla de Pascua), que de ser aprobada por la comunidad local pasaría a ser la más grande del continente americano y una de las tres mayores del mundo, superando incluso al parque marino Nazca-Desventuradas El parque marino en la Isla de Pascua se sumaría a un área protegida ya establecida de 150.000 km2: el Parque Marino Motu Motiro Hiva, que incluye la isla Salas y Gómez. No obstante, en la creación de esta en 2010 no se involucró a los locales, lo que ha traído varios conflictos que interfieren en su funcionamiento, más aún considerando que según el Convenio 169 del Organismo Internacional de Trabajo (OIT) sobre pueblos indígenas y tribales, se debe hacer una consulta pública a los involucrados directos. Por ello en junio de 2014 se creó la “Mesa del mar” que sentó a isleños, científicos y autoridades políticas a conversar sobre la nueva área bajo protección que sumaría otros 570.000 km2 en la zona. La propuesta anunciada por la presidenta Bachelet será votada por los isleños en 2016, momento en que se definirá su creación o no. Si se llegan a materializar los tres parques, Chile tendrá protegido el 25,3% de su territorio marino, superando ampliamente al 12,6% de Reino Unido, al 15,5% de Estados Unidos y al 15,2% de Nueva Zelanda.
Los fondos profundos alrededor de San Félix y San Ambrosio, parte del parque marino Nazca-Desventuradas, se encuentran en un estado excepcional de conservación y no se observan señales de impacto humano. Foto de Enric Sala /National Geographic Proteger la biodiversidad Según datos recolectados por la Asociación para Estudios Interdisciplinarios de los Océanos Costeros (PISCO, en sus siglas en inglés), estudios realizados en 124 parques marinos alrededor del mundo señalan que tras establecida la protección en los océanos, en promedio, la biomasa se incrementa en 446% y su densidad en 166%, mientras que el tamaño de los animales aumenta 28% y la diversidad 21%. En tanto que cuando se trata de especies que fueron severamente explotadas, el incremento de la biomasa en algunos casos ha llegado al 1000%. Justo eso es lo que se busca lograr en Chile. Por ejemplo, el reporte realizado por PISCO y presentado en la “Mesa del Mar” señala que si se protege a la corvina, un pez presente en aguas chilenas, su capacidad de reproducción se disparará: mientras que un individuo de 50 centímetros de largo puede generar una descendencia de 6.000, uno de 70 centímetros logra dejar 43.000. Mas eso es solo parte de lo que se puede lograr. La diferencia entre proteger o no puede ser inmensa, especialmente cuando el nivel de endemismo de la zona es alto, algo que ocurre en el parque marino Nazca-Desventuradas. En 2013, Oceana y National Geographic se embarcaron en una campaña científica en la zona y encontraron allí un hotspot de peces de arrecifes donde el 72% de las especies observadas se conocen solo en el área. “Estos son los porcentajes de endemismo más altos jamás registrados en el mar”, dice el informe. “Además, es una zona endémica de alimentación y reproducción de juveniles del jurel. Luego de lo cual viajarían desde Juan Fernández hasta Nueva Zelanda”, agrega Liesbeth van der Meer, directora de Campañas de pesquerías de Oceana en Chile. Y si a ello se suma el que la zona es un corredor biológico para diversas especies, se vuelve un ejemplo claro de que el beneficio va más allá de las áreas protegidas mismas. Mucho por hacer “Es muy importante que se creen zonas protegidas para resguardar al biodiversidad”, dice Jane Lubchenco, académica de la Universidad Estatal de Oregon, Estados Unidos, y parte del grupo de trabajo que elaboró el informe para la creación del parque en Isla de Pascua. No obstante, el problema es que la mayoría de las aguas no cuentan con protección alguna. Si bien entre 1995 y 2005 se dio un gran salto al aumentar del 0,1% al 1,6% las áreas protegidas, esto no es suficiente, dice Jane Lubchenco. Así lo planteó, junto con Kirsten Grorud-Colvert, en un trabajo publicado en octubre en la revista Science donde aseguran que si la estimación de lo que se debe proteger concordara con los números que entrega la ciencia, el área estrictamente controlada debiera estar entre el 20 y 50%. Latinoamérica y el Caribe no escapa de esa realidad mundial. Los parques marinos en esta región abarcan menos del 0,1% de la zona económica exclusiva y la mayoría son pequeños –la mitad de ellos cubren menos de 7 km2–, según datos de PISCO. De 255 parques marinos, tan solo doce de ellos son patrullados periódicamente para prevenir la pesca ilegal.
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| Científicos argentinos han encontrado que la proteína galectina-1 juega un rol en la protección de las células cardíacas contra el parásito que causa la enfermedad de Chagas. Por Valeria Román 30 de octubre de 2015 Todo comienza con síntomas similares a los de la gripe, acompañados de fiebre, erupciones cutáneas o párpados inflamados… y luego desaparece...o quizás no. Si no es tratado en las etapas iniciales con fármacos que matan al parásito, tras la etapa aguda de la enfermedad de Chagas, el parásito Tripanosoma cruzi puede quedar latente en el cuerpo, convirtiéndose en una enfermedad crónica que puede causar graves consecuencias cardíacas e intestinales en el individuo. La enfermedad de Chagas, bastante común en América Latina, es la tercera infección parasitaria con más prevalencia en el mundo, después de la malaria y la esquistosomiasis. El parásito que causa la enfermedad de Chagas –que afecta a más de 7 millones de personas en el mundo– es diseminado por insectos hematófagos (que se alimentan de sangre) infectados, conocidos como vinchucas o chinches. La enfermedad también puede diseminarse a través de los alimentos contaminados, una transfusión de sangre, un órgano donado o de madre a hijo durante el embarazo. Si bien existen dos medicamentos para tratar la infección en la etapa aguda, aún faltan tratamientos más eficaces y seguros para la etapa crónica, que puede desarrollarse más de 20 años después de que el Tripanosoma cruzi haya ingresado al organismo. Hasta el 30% de los infectados con el parásito de la enfermedad de Chagas desarrollan un problema en el corazón, que puede llevar a la muerte. Ahora, un equipo de científicos de la Argentina descubrió un mecanismo molecular por el cual la infección podría ser mejor controlada. Tras la proteína galectina-1 El equipo de científicos del Instituto de Biología y Medicina Experimental (IBYME), del Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI) y otras instituciones públicas de la Argentina realizaron un estudio para saber cuál era el rol de la proteína galectina-1 en la interacción entre el parásito que causa Chagas y la persona infectada. Eligieron ese camino pues ya se conocía que esa proteína está asociada con el avance de otras enfermedades, como el cáncer y la artritis reumatoidea. Durante el estudio, cuyo resultados se publicaron en la revista PLOS Neglected Tropical Diseases, los investigadores examinaron 28 pacientes: 19 ya tenían síntomas cardíacos y 9 estaban en fase asintomática. Luego, los compararon con 42 personas que no habían sido infectadas por el parásito. Los científicos detectaron que los infectados por el parásito del Chagas tenían niveles más elevados de la proteína galectina-1, aún si no presentaban los síntomas, en comparación con los no infectados. Después, el equipo de científicos –integrado por Alejandro Benatar, Karina Gómez, Gabriela García, Gabriel Rabinovich y Marta Toscano, entre otros– tomó células del corazón de ratones murinos. En el laboratorio, incubaron a esas células con la proteína galectina-1 y luego las infectaron con el Tripanosoma cruzi. El resultado de ese experimento fue que había menos parásitos en las células cardíacas que contaban con la presencia de la proteína. Por lo cual se indicaría que la proteína podría ayudar a limitar el avance de los parásitos. Además, los investigadores hicieron un segundo experimento para contar con más evidencias: a través del peritoneo, que es la membrana que cubre el abdomen, les inyectaron parásitos a ratones que no tenían el gen que codifica para la proteína galectina-1. Observaron que los animales que tenían desactivado el gen tenían más parásitos en su sangre y en el tejido cardíaco, en comparación con animales salvajes que sí tenían la proteína. “Nuestro trabajo demuestra que la proteína puede disminuir la infección por el parásito en las células cardíacas. Pero también detectamos que el parásito puede alterar a esas células y restringir la actividad de la misma proteína. El rol de la galectina-1 en la interacción entre el parásito y el huésped es fascinante pero es un área que necesita más investigación”, dijo a Scientific American, la investigadora Karina Gómez. “Sabemos que el avance de la enfermedad de Chagas depende de muchos factores, como el linaje del parásito que afecta a cada infectado y hasta la genética del mismo paciente. Aún no se conoce bien por qué solo el 30% de los infectados desarrolla alteraciones cardíacas. Ahora, tenemos evidencia de que la proteína galectina-1 podría ser capaz de prevenir el daño, al menos en células cardíacas en animales”, explicó Gómez. La investigadora espera para el futuro que se pueda desarrollar un tratamiento con galectina-1 que funcione como complementario a los medicamentos convencionales. “Una terapia con galectina-1 podría ayudar a reducir la dosis de los tratamientos antiparasitarios. Así el tratamiento tendría menos efectos colaterales. Por supuesto, estamos aún en una etapa muy preliminar, pero hay una búsqueda mundial para encontrar drogas más seguras para Chagas”. agregó Gómez, cuyo trabajo fue financiado por la Agencia Nacional de Promoción Científica y Tecnológica, el Conicet y la Fundación Florencio Fiorini. Consultado por Scientific American, Sergio Sosa-Estani, del Centro Nacional de Diagnóstico e Investigaciones Endemo-epidémicas, que no participó en los trabajos publicados, consideró que “el hallazgo demuestra que existe un mecanismo específico de la relación entre el huésped, la persona afectada, y el parásito que causa la enfermedad de Chagas. Esa relación puede modificar la capacidad del parásito de hacer más o menos daño sobre el paciente. La identificación de este tipo de mecanismos puede ser útil para diseñar estrategias con drogas o vacunas terapéuticas en el futuro”.
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Posted: 04 Nov 2015 10:00 AM PST La marque Quinny a récemment lancé sa Longboardstroller : un longboard imaginé pour faciliter les déplacements des familles dans les villes. Cette planche possède une poussette intégrée dans laquelle les parents peuvent promener leurs enfants pendant leurs courses et rendez-vous, tout en faisant du skate, de manière ludique. |
Energy drinks have grown in popularity for many people in the US, but there is growing concern about the health risks of consuming them in large quantities. Because men are the main consumers of energy drinks, a research team lead by Dr. Ronald F. Levant, a professor of psychology at The University of Akron, set out to study a possible link between masculinity, expectations about the benefits of consuming energy drinks, how those expectations affect energy drink use, and the impact on sleep. Their findings were published in the November 2015 issue of Health Psychology.Energy drinks are often marketed as "masculine" drinks. Commercials and ads for them often show men engaging in high-risk, adrenaline-pumping activities such as skydiving or snowboarding. Energy drinks also sponsor many sporting events, such as ultimate fighting leagues, racing, and motocross. "While most men who buy energy drinks aren't martial arts champions or race car drivers, these marketing campaigns can make some men feel as though drinking energy drinks is a way to feel closer to, or associated with, these ultra-masculine sports," says Dr. Levant. The research team collected data from 467 adult men. The first survey was the Male Role Norms Inventory short form (MRNI-SF), developed by Dr. Levant, used to measure agreement with traditional masculine attitudes like, "Men should not be too quick to tell others that they care about them," and "I think a young man should try to be physically tough, even if he's not." The second survey measured expectations about the effects of energy drinks and included beliefs like, "If I consume energy drinks, I will be more willing to take risks," and "If I consume energy drinks, I will perform better." The final survey, adapted from a standard sleep quality index, measured disturbances in the men's sleep patterns, such as getting up to use the bathroom during the night or having trouble falling asleep. Levant explains that they "found associations between beliefs in traditional masculinity, beliefs in the efficacy of energy drinks, energy drink consumption, and sleep disturbances with a few notable exceptions." Levant continues, "Older men were, more or less, exempt from the trend, and non-white men who endorsed traditional masculinity believed in the efficacy of energy drinks, but this belief didn't translate into actual use." However, for young white men in the sample, the associations were clear. "The link between masculinity ideology and energy drink use suggests that energy drink use may be a means of performing masculinity... as a way to raise masculine capital," Levant says, noting that this performance could be a way of "demonstrating that one is consuming products that are associated with the engagement in extreme sports or an otherwise active and competitive lifestyle." The study also argues that this link could have negative effects on men's health. Many energy drinks have high caffeine content; when consumed in excess, caffeine can accelerate the heart rate, increase anxiety, and contribute to insomnia. Men who perceive energy drinks as 'magic potions' for performance enhancement, the study suggests, are better served moderating their consumption. Energy drinks contain very large amounts of caffeine, and the Food and Drug Administration (FDA) does not require caffeine quantities to be displayed on beverage labels," says Levant. "Because of this, some people may drink more caffeine through energy drinks than they might have intended to throughout a day, and drinking large amounts can cause problems--especially with sleep." Story Source: The above post is reprinted from materials provided by American Psychological Association. Note: Materials may be edited for content and length. Journal Reference:
http://www.sciencedaily.com/releases/2015/11/151104150958.htm
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Posted: 02 Nov 2015 12:00 PM PST L’artiste allemand Wilfried Grootens est l’auteur de superbes peintures en relief. Pour parvenir à ce résultat, il peint d’étranges formes à l’aide de points et de lignes sur des dizaines de couches de verre très fines. Ce travail minutieux offre des oeuvres abstraites étonnantes qui paraissent flotter dans leur cube de verre.
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O exame mais solicitado aos portadores de hepatite C são as transaminases. Vamos tentar explicar, de forma simples algumas duvidas que a maioria dos portadores nos fazem chegar. O que são as Transaminases? Um passo inicial para detectar problemas no fígado é um exame de sangue para determinar a presença de certas enzimas no sangue, comumente chamadas de transaminases. Debaixo de circunstâncias normais, estas enzimas residem dentro das células do fígado. Mas quando o fígado está com problemas, estas enzimas são derramadas no fluxo de sangue. Entre as mais sensíveis destas enzimas é as mais representativas estão as transaminases. Elas incluem a aminotransferase de aspartate (AST ou SGOT ou TGO ou GOT) e a aminotransferase de alanine (ALT ou SGPT ou TGP ou GPT). Estas enzimas normalmente são contidas dentro das células do fígado. Se o fígado estiver com algum problema, as células derramam as enzimas na corrente sanguínea, elevando os níveis destas enzimas no sangue e sinalizando o problema que possa existir. As transaminases catalisam reações químicas nas células nas quais um grupo de amino é transferido de uma molécula doadora a uma molécula recipiente. Conseqüentemente, disto deriva o nome "transaminases". Normalmente, onde as transaminases são produzidas? TGO ( AST ou SGOT ou GOT) normalmente é encontrado em uma diversidade de tecidos inclusive o fígado, coração, músculos, rim, e cérebro. É liberado no sangue quando qualquer um destes tecidos estiver estragado. Por exemplo, seu nível no sangue sobe com ataques de coração e com desordens nos músculos. Não é então um indicador altamente específico de dano no fígado. TGP (ALT ou SGPT ou GPT) é encontrado em grande parte no fígado. Este não é produzido exclusivamente pelo fígado, porém é onde se encontra mais concentrado. É liberado na circulação sangüínea como o resultado de dano hepático. Serve então como um indicador bastante específico do estado do fígado. O que são níveis normais de TGO e TGP? A gama normal de valores para TGO é de 5 a 40 unidades por litro de soro (a parte líquida do sangue). A gama normal de valores para TGP é de 7 a 56 unidades por litro de soro. Estes valores dependem do fabricante do teste. É necessário sempre verificar quais são os valores de referencia para poder comparar os resultados. Tente, sempre que possível, fazer o exame no mesmo laboratório, assim poderá ser feita uma media comparativa dos resultados. O que significam ter resultados de TGO e TGP elevados? TGP e TGO são indicadores sensíveis de dano hepático em diferentes tipos de doenças. Mas deve ser enfatizado que ter níveis mais altos que o normal destas enzimas não indicam, necessariamente, uma doença hepática estabelecida. Eles podem indicar algum problema ou não. A interpretação dos níveis altos de TGO e TGP depende do quadro clínico em geral e assim é melhor que isto seja determinado por médicos experimentados em hepatologia. Os níveis destas enzimas não medem a extensão de dano no fígado ou mostram um prognostico da evolução futura. Assim, os níveis de TGO e TGP não podem ser usados para determinar o grau de dano hepático ou predizer o futuro. Em pacientes com hepatite A aguda, as TGO e TGP são muito altas (às vezes alcançam milhares de unidades), porém a maioria destes pacientes com hepatite A recupera completamente o fígado, não ficando nenhum dano. Na hepatite C só e observada uma pequena elevação nas TGO e TGP, sendo que alguns destes pacientes podem ter evoluído para uma doença crônica com fibroses ou cirroses. Que doenças causam níveis de transaminases anormais? São encontrados níveis mais altos de TGO e TGO em desordens que causam a morte de numerosas células (necrose hepática extensa). Isto acontece nas hepatites agudas A ou B, no dano pronunciado infligido por toxinas como o de uma overdose de acetaminofen (TYLENOL) ou quando o fígado é privado de sangue fresco que traz oxigênio e nutrientes. As transaminases nestas situações podem variar de dez vezes os limites superiores do normal para milhares de unidades por mililitro. Moderadas elevações das transaminases são comuns. Elas são encontradas freqüentemente em exames de sangue de rotina em indivíduos saudáveis. Os níveis das transaminases em tais casos normalmente se situam entre duas vezes os limites superiores do normal e várias centenas de unidades. É sempre importante se fazer a media dos últimos quatro resultados encontrados, para saber ao certo como estão as transaminases. A causa mais comum de moderadas elevações destas enzimas é o fígado gorduroso (esteatose). A causa mais freqüente de fígado gorduroso é o abuso de álcool. Outras causas de fígado gorduroso incluem a diabete e a obesidade. A hepatite C também está se tornando uma causa importante de elevações das transaminases. Que medicamentos causam níveis de transaminases anormais? Alguns medicamentos podem elevar as transaminases, entre eles temos os que contem os seguintes principios ativos: Medicamentos para alívio da dor com aspirina, acetaminofen, ibuprofen, neproxen, diclofenac e feenybutazone. Medicamentos de antiataque apopléctico com fenytoin, ácido valproico, carbamazepine e fenobarbital. Antibióticos como as tetraciclinas, sulfonamides, isoniazid (INH), sulfametoxazole, trimetoprim, nitrofurantoin, etc. Drogas para o colesterol como o "statins" e niacina. Drogas cardiovasculares como amiodarone, hidralazine, quinidine, etc. Anti-depressivos do tipo de tricyclic. Com anormalidades das transaminases, originadas por medicamentos, os valores voltam ao normal semanas ou meses depois de parar com os medicamentos. Quais são as causas menos comuns de níveis de transaminases anormais? Causas menos comuns de transaminases anormais incluem a hepatite B crônica, a hemocromatosis, a doença de Wilson, e a hepatite autoinmune. Embora não tão comum quanto na hepatite C, a hepatite B pode ficar crônica com resultados anormais nas transaminases. Hemacromatose é uma desordem genética no qual há absorção excessiva de ferro ingerido na alimentação conduzindo a acumulação de ferro no fígado produzindo inflamação que pode levar a fibroses e cirroses. A doença de Wilson é uma desordem hereditária com acumulação excessiva de cobre em tecidos diversos inclusive o fígado e o cérebro. Cobre no fígado pode produzir inflamação, enquanto que o cobre no cérebro pode causar problemas psiquiátricos e perturbações motoras. A hepatite autoinmune e provocada pelos próprios anticorpos do corpo e sistemas de defesa que atacam o fígado. Raramente as transaminases anormais podem ser um sinal de câncer no fígado. Como as pessoas saudáveis, com transaminases anormais devem ser avaliadas? Avaliação de pacientes saudáveis com transaminases anormais devem ser feitas de forma individualizada. O médico pode pedir resultados de exame de sangue antigos para comparação. Se nenhum registro antigo estiver disponível, será necessário repetir os exames de sangue por semanas ou meses para ver se estas anormalidades persistem. O médico procurará fatores de risco para hepatites B e C que incluem múltiplos parceiros sexuais, história de transfusões de sangue, uso de drogas injetáveis ou aspiradas e exposição profissional. Uma história familiar de doenças pode indicar a possibilidade de doenças hereditárias como hemocromatosis ou a doença de Wilson, O padrão de anormalidades das transaminases pode prover pistas úteis da causa da doença. Por exemplo, a maioria de pacientes com doença de fígado alcoólica tem níveis de transaminases que não são tão altas quanto os níveis observados na hepatites viróticas agudas e o TGO tende a ficar maior que o TGP. Assim, em doença de fígado alcoólica, o TGO está normalmente debaixo de 300 unidades enquanto o TGP normalmente fica debaixo de 100 unidades. Se o álcool ou medicamentos são os responsáveis pelos níveis anormais das transaminases, ao eliminar o uso de álcool ou do medicamento os níveis deverão voltar ao normal em semanas ou meses. Se for suspeitada obesidade como a causa de fígado gorduroso, uma redução do peso de 5% a 10% também deveria trazer as transaminases a níveis normais ou próximos do normal. Se as transaminases anormais persistirem apesar de abstinência de álcool, redução de peso e com a eliminação das drogas suspeitas, deverão ser realizados exames de sangue para diagnosticar outras doenças no fígado. Deve-se testar a presença de hepatites B e C, o nível de ferro, e a ferritina, que e normalmente elevada em pacientes com hemocromatosis. Os níveis de certos anticorpos específicos podem estar elevados em pacientes com hepatite autoinmune. O ultra-som pode ser usado para excluir suspeitas de tumores que possam estar obstruindo os canais que conectam o fígado. A biópsia é um procedimento onde uma agulha é inserida pela pele em cima do abdômen superior para obter uma pequena quantidade de tecido hepático para ser examinado em um microscópio. Não todos os que têm transaminases anormais precisam de uma biópsia. O médico normalmente recomendará este procedimento se: 1) as informações obtidas da biópsia serão úteis para planejar o tratamento, 2) o médico precisa saber a extensão e a severidade do dano hepático, ou 3) avaliar a efetividade ou necessidade de tratamento. Existem outras enzimas? Alem da TGO e TGP, há outras enzimas que incluem a fosfatase alcalina e a gama glutamil transferese (GGT) as quais são testadas durante o tratamento da hepatite ou em pacientes com doenças mais avançadas. Neste artigo nós restringimos as AST ou TGO e ALT ou TGP porque elas são as mais úteis e importantes no controle da hepatite C. Carlos Varaldo www.hepato.com hepato@hepato.com
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| Cars could soon be lighter and stronger, thanks to vaporized foil actuator welding (Credit: Shutterstock) As manufacturers, particularly in the automobile industry, continue to work toward incorporating lighter metals like aluminum with heavier steel, the ongoing problem has been how to successfully weld them together. The problem is that the high heat created in the welding process actually weakens these lighter metals, creating a less than optimum weld. After 10 years of research, engineers at The Ohio State University have developed a new welding technique that may prove to solve this problem while also using 80 percent less energy and creating bonds that are 50 percent stronger. "With our method, materials are shaped and bonded together at the same time, and they actually get stronger," says Glenn Daehn, professor of materials science and engineering at Ohio State, who helped develop the new technique. The traditional technique, called spot resistant welding, works by passing an electrical current through pieces of metal using the natural electrical resistance within those metals. This generates heat that melts them together to form a weld. This process consumes a lot of energy, and the melted metals are left in a weaker state than they were before. What Daehn and his team have done is create a new welding method called vaporized foil actuator (VFA) using short high voltage electrical pulses (lasting millionths of a second) passed through an aluminum foil, and a burst of hot gas traveling at speeds approaching thousands of miles per hour, to bond the atoms of one metal to atoms on the other. Since the two different bonded metals don’t melt, neither metal is weakened and the resulting seam is stronger. The energy savings comes from the fact that the electrical pulse is so short and the required energy to vaporize the foil is less than is necessary to melt the parts together in a traditional process. Daehn and his team have already used the process to successfully bonded different combinations of copper, aluminum, magnesium, iron, nickel and titanium. They have created strong bonds between commercial steel and aluminum alloys – a feat which is impossible normally. VFA is evidently also able to shape metal parts during the welding process, which could save manufacturers an additional step. In 2012, Honda announced it had created a similar result, welding aluminum to steel using a variation of a process called friction stir welding (FSW). Rather than the high heat and gas applied to a third element like the aluminum foil used in the VFA process, FSW uses heat, friction and pressure with a third element to meld two metals together. Like VFA, it uses less energy and creates a bond that has been proven to be stronger than that created by a traditional welding process. Variations of FSW have since been used by Lincoln, Mazda and Audi. Source: The Ohio State University
http://www.gizmag.com/vaporized-foil-actuator-welding/40137/ |
| Dental implants could soon have built-in antibacterial properties (Credit:Shutterstock) Creating replacement parts for various bits of the human body is one of the many areas in which 3D printing has huge potential. Dental implants are on that list, too, and if new research out of the University of Groningen in the Netherlands comes to fruition, 3D-printed replacement teeth could come with the added bonus of being able to destroy 99 percent of bacteria that they come into contact with. The research team, led by Andreas Hermann, has developed a process to manufacture 3D-printed teeth and braces capable of destroying bacteria using a special type of antimicrobial resin. To create the resin, the researchers combined antibacterial ammonium salts with standard dental resins. The resultant mixture was then hardened using ultraviolet light and put inside a 3D printer to print samples of replacement teeth. The positive charge on the ammonium salts gives the resin its bacteria-killing property, disrupting negatively charged bacterial membranes and causing them to burst and die. To test the antibacterial capacity of the resin the researchers applied a mixture of saliva and tooth decay-causing bacteria Streptococcus mutans on the samples of the replacement teeth and found that the material was effective in destroying 99 percent of the bacteria colonies on the sample. The material can kill bacteria on contact but is not harmful to human cells, Hermann told New Scientist. It's not all smiles though. In a review of the study Nicholas Staropoli, a research associate for the American Council on Science and Health, points out that while the teeth could prevent oral infections, such as endocarditis, and preserve dental implants, it could also wipe out helpful bacteria that help protect a person from harmful pathogens. As of now the material is still a prototype and according to the researchers further testing will be required before human trials can be conducted. In addition to inhibiting bacterial damage to teeth implants, the researchers believe the material may also be suitable for orthopaedic and non-medical applications, such as water purification, food packaging and children’s toys. The research paper entitled 3D-Printable Antimicrobial Composite Resins is published in the journal Advanced Functional Materials.
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| Lack of adequate sleep can do more than just make you tired. It can short-circuit your system and interfere with a fundamental cellular process that drives physical growth, physiological adaptation and even brain activity, according to a new study from the University of Tennessee, Knoxville. Albrecht von Arnim, a molecular biologist based in the Department of Biochemistry and Cellular and Molecular Biology, studied plants but said the concepts may well translate to humans. His team examined how protein synthesis--the process that determines how organisms grow and how cells renew themselves--changes over the course of the daily day-night cycle. He also explored whether any such changes are controlled by the organism's internal time keeper, the circadian clock. Proteins are newly created in every cell by translating messages made from the cell's own DNA, the genome. Von Arnim's findings, published in the journal Plant Cell, show not only that protein synthesis activity changed over the course of the day, but also that it was under the influence of the circadian clock. "When we misalign our behavior with our circadian clock, for example by creating jet lag, or by working as a night owl, we do not only disrupt normal physiological processes such as cycles of appetite and body temperature," von Arnim said. "This work in plants suggests that we may also be interfering with a more fundamental cellular process, protein synthesis." Muscle action, brain activity, growth and development are functions all performed by proteins whose synthesis is carefully regulated, he said. "For example, when cells are stressed by high temperatures or from a virus infection, they drastically reduce their protein synthesis activity," von Arnim said. The findings could also have implications for agricultural production as farmers and companies seek to better cultivate land and maximize outputs from plants required to sustain human life. "Protein synthesis is part of the basis for crop yield," von Arnim said. Story Source: The above post is reprinted from materials provided by University of Tennessee at Knoxville. Note: Materials may be edited for content and length. Journal Reference:
http://www.sciencedaily.com/releases/2015/10/151030153115.htm
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What people believe they want and what they might actually prefer are not always the same thing. And in the case of being outperformed as an element of romantic attraction, the difference between genuine affinity and apparent desirability becomes clearer as the distance between two people gets smaller.In matters of relative performance, distance influences attraction. For example, someone of greater intelligence seems attractive when they're distant or far away in your mind. But less so when that same person is right next to you, according to a new study by a University at Buffalo-led research team published in the latest edition of the journal Personality and Social Psychology Bulletin. "We found that men preferred women who are smarter than them in psychologically distant situations. Men rely on their ideal preferences when a woman is hypothetical or imagined," said Lora Park, associate professor in the UB Department of Psychology and the study's principal investigator. "But in live interaction, men distanced themselves and were less attracted to a woman who outperformed them in intelligence." Previous research has shown that similarities between individuals can affect attraction. This new set of studies suggests that psychological distance -- whether someone is construed as being near or far in relation to the self -- plays a key role in determining attraction. "It's the distinction between the abstract and the immediate," says Park. "There is a disconnect between what people appear to like in the abstract when someone is unknown and when that same person is with them in some immediate social context." Even though the research focus of the current study was on romantic attraction and, specifically, men's interest in women, Park says the result might potentially be a broader phenomenon, extending to other interpersonal situations. "That's a question for future research," she said. "But presumably, anyone who is outperformed by someone close to them might feel threatened themselves. We just happened to look at men in a romantic dating context." Park's team conducted six separate studies involving 650 young adult subjects. The studies ranged from presenting subjects with hypothetical women, to women they expected to meet, to actually engaging in an interpersonal interaction. "In each case, how much you like someone or how much you are attracted to them is affected by how intelligent that person is relative to you and how close that person is relative to you," said Park. But the area of performance has to be something important to the individual. "The domain matters," says Park. "If you don't care about the domain, you might not be threatened. Yet, if you care a lot about the domain, then you might prefer that quality in somebody who is distant, then feel threatened when that person gets close to you." Story Source: The above post is reprinted from materials provided by University at Buffalo. The original item was written by Bert Gambini. Note: Materials may be edited for content and length. http://www.sciencedaily.com/releases/2015/10/151030161339.htm
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| Diet diversity, as defined by less similarity among the foods people eat, may be linked to lower diet quality and worse metabolic health, according to researchers at The University of Texas Health Science Center at Houston (UTHealth) and the Friedman School of Nutrition Science and Policy at Tufts University. The study was published today in PLOS ONE. "'Eat everything in moderation' has been a long-standing dietary recommendation, but without much empiric supporting evidence in populations. We wanted to characterize new metrics of diet diversity and evaluate their association with metabolic health," said Marcia C. de Oliveira Otto, Ph.D., first author and assistant professor in the Department of Epidemiology, Human Genetics and Environmental Sciences at UTHealth School of Public Health. Using data from 6,814 participants in the Multi-Ethnic Study of Atherosclerosis, a study of whites, blacks, Hispanic-Americans and Chinese-Americans in the United States, the authors measured diet diversity through different measures. These included the total count (number of different foods eaten in a week), evenness (the distribution of calories across different foods consumed), and dissimilarity (the differences in food attributes relevant to metabolic health, such as fiber, sodium or trans-fat content). Researchers evaluated how diet diversity was associated with change in waist circumference five years after the beginning of the study and with onset of Type 2 diabetes 10 years later. Waist circumference is an important indicator of central fat and metabolic health. When evaluating both food count and evenness, no associations were seen with either increase in waist circumference or incidence of diabetes. In other words, more diversity in the diet was not linked to better outcomes. Participants who had the greatest food dissimilarity actually experienced more central weight gain, with a 120 percent greater increase in waist circumference than participants with the lowest food dissimilarity. To compare with the results seen for diet diversity, the researchers also examined how diet quality relates to metabolic health. Diet quality was measured using established scores such as the Dietary Approaches to Stop Hypertension (DASH) score and the Alternative Healthy Eating Index (AHEI) score. At five years, diet quality was not associated with change in waist circumference. At ten years, higher diet quality was associated with about a 25 percent lower risk of developing Type 2 diabetes. "An unexpected finding was that participants with greater diversity in their diets, as measured by dissimilarity, actually had worse diet quality. They were eating less healthy foods, such as fruits and vegetables, and more unhealthy foods, such as processed meats, desserts and soda," said Otto. "This may help explain the relationship between greater food dissimilarity and increased waist circumference." Dietary diversity as measured by food count and evenness was also associated with higher intakes of both healthy and unhealthy foods. "People in the US with the healthiest diets actually eat a relatively small range of healthy foods," said Dariush Mozaffarian, M.D., Dr.P.H., senior author and dean of the Friedman School of Nutrition Science and Policy at Tufts University in Boston. "These results suggest that in modern diets, eating 'everything in moderation' is actually worse than eating a smaller number of healthy foods." Nikhil S. Padhye, Ph.D., from UTHeath School of Nursing, was a coauthor on the study. Funding came from a research supplement grant awarded to Otto by the National Heart, Lung and Blood Institute of the National Institutes of Health, as part of a larger research grant number R01HL085710, whose principal investigator is the senior author Mozaffarian.
Story Source: The above post is reprinted from materials provided by University of Texas Health Science Center at Houston. Note: Materials may be edited for content and length. Journal Reference:
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Posted: 31 Oct 2015 03:00 AM PDT
Trouvant ses origines dans la dynastie Tang (environ en -700 avant Jésus Christ), l’artisanat chinois du bois de la région de Dongyang présente des sculptures incroyables et hyper détaillées. Ces formes élégantes possèdent énormément de relief et mettent en scène des sortes de dioramas muraux. Cette discipline traditionnelle est encore pratiquée aujourd’hui dans cette région (où on trouve quelques workshops) et servent à décorer son intérieur ou ses meubles.
