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September 27th, 2020 by Dr. Hannah Sivak
What can you do about it? Lots more than wrapping a scarf around your neck. Makeup can hide, cosmetic surgery can cut, but neck and hands will show the real age of your skin. What can you do about it? You can write a great book as Nora Efron did (“I feel bad about my neck”) or you can wear fancy silk scarves. If you don’t feel like writing a book or don’t like the idea of wearing a scarf in Summer, you have an alternative. Don’t just privilege your face over your neck and hands; they are all part of your body. Use the same products you use on…
September 11th, 2020 by Dr. Hannah Sivak
La Solución Ordinary Peeling: Ingredientes: Ácido glicólico, agua, agua de hoja de aloe barbadensis, hidróxido de sodio, extracto de zanahoria, propanediol, cocamidopropil dimetilamina, ácido salicílico, citrato de potasio, ácido láctico, ácido tartárico, ácido cítrico, pantenol, crospolímero de hialuronato de sodio, Extracto de fruta/hoja de Tasmannia Lanceolata , glicerina, pentilenglicol, goma xantana, polisorbato 20, disuccinato de etilendiamina trisódico, sorbato de potasio, benzoato de sodio, etilhexilglicerina, 1,2-hexanodiol, caprilil glicol. Muy ordinaria. ¿Por qué? Es más de lo mismo: se infla el número inflado de los ácidos en la concentración de ácido cuando la mayor parte de ellos son en realidad sales. Más ordinaria: una lista de ácidos figuran en la fórmula solo…
June 22nd, 2020 by Dr. Hannah Sivak
¿Estás buscando una explicación extensa? Aquí la tenés.La explicación breve es ésta: los péptidos son una pequeña cadena de aminoácidos. Sí, tenés que saber que los aminoácidos (alrededor de 20) forman las proteínas que componen nuestro cuerpo.Quitemos el halo mítico a la palabra “péptido”. ¡No hay magia en ellos! Cuanto más cortos, menos pueden hacer (salvo que estemos hablando del glutatión).Esos péptidos cortos que tanta propaganda tienen en la industria del cuidado de la piel son en su mayoría inútiles. Algunos de ellos hasta pueden envejecer tu piel, pero no por el péptido sino por el cobre que contienen (¡corré cuando veas algo azul!).¿Dónde podés encontrar verdadero valor para tu…
June 12th, 2020 by Dr. Hannah Sivak
We Still Go Back and Read Darwin’ Scientist David Baltimore, 82 It’s like a bad dream come true. I started off as a virologist, have read a lot about the influenza epidemic of 1918–19, and I’ve always felt a wonderment that it doesn’t happen more frequently. There are so many viruses out there in the world. Between my junior and senior years of high school, I did a visit at a mouse-research laboratory in Bar Harbor, Maine. It was on a whim, a suggestion of my mother’s. What I discovered over that summer was that the forefronts of research were available to me. I could work on a problem that…
March 26th, 2020 by Dr. Hannah Sivak
March 21st, 2020 by Dr. Hannah Sivak
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the disease it causes, coronavirus disease 2019 (COVID-19) has changed the world. We are baffled, perplexed, disconcerted, confused. We never lived through a situation like we are living now. The closest it gets (for me) are the polio epidemics of 1949, 1950, 1951, 1953. Yes, year after year because epidemics (and pandemics) don’t disappear “miraculously”, although sometimes it sort of looks like it (more about this later). Although this pandemic had been predicted by so many epidemiologists and scientists, it still found us unprepared. This is shocking but not unexpected. Perhaps it’s human nature that if something it’s not happening now,…
March 14th, 2020 by Dr. Hannah Sivak
Life happens. Viruses (non-life) happen. Viruses vary in how contagious they are, which human organs they prefer to attack, how lethal they are. It’s all in their DNA or, in the case of coronaviruses, their RNA (but we must remember that RNA mutates, a lot). Even if covid 19 “goes away” in the Summer, it is extremely likely that it will be back next Winter. If it behaves like other viruses (1918 “Spanish flu”), it may come back mutated and more lethal. There are no miracles, only Nature. Eventually, humans will develop resistance to the virus, sooner than later if/when we get the vaccine. And let’s hope that the scientific…
March 10th, 2020 by Dr. Hannah Sivak
Pregunta: ¿Qué es peor que no tener desinfectante para manos durante una epidemia / pandemia viral? Respuesta: Usar un “falso” desinfectante de manos, uno que no mata los virus pero te da una (falsa) sensación de seguridad. Es cierto que algunos aceites esenciales registran actividad contra ciertos virus en ciertas circunstancias (las plantas tienen que defenderse contra los virus), pero esto no significa que el aceite esencial en cuestión proporcione protección contra la infección que puede provocar cualquier tipo de virus. Sé lo difícil que es conseguir un desinfectante para manos. También es difícil obtener alcohol en gel (isopropíl), apto para frotar las manos. Por cierto, el vodka contiene aproximadamente…
December 27th, 2019 by Dr. Hannah Sivak
Después de una cirugía bariátrica, tendrás pérdidas y ganancias; en algunos aspectos será excelente y en otros no tanto. Para muchos, la cirugía bariátrica extenderá su vida y mejorara enormemente la calidad. Pero, tiene pros y contras. Estos son algunos ejemplos de lo que perderás/podés perder, según lo que hagas después de la cirugía. Peso Diabetes (¡sí!) Esto ayudará a su piel porque habrá menos glicosilación de proteínas, y eso es bueno para las proteínas y para vos. Masa muscular (vas a tener que hacer mucho ejercicio y comer proteínas, consultá a tu médico) Capacidad de absorber vitaminas (deberás tomar un multivitamínico fácilmente absorbible de por vida) Capacidad de digerir…
December 15th, 2019 by Dr. Hannah Sivak
Comencemos por el principio. ¿Qué es la gayuba? Una planta. ¿Qué es la arbutina? Un químico. Superado este punto, veamos los detalles. Figura. Thomé Flora von Deutschland, Österreich und der Schweiz 1885. Arctostaphylos uva-ursi (L.) se trata de una planta utilizada en la medicina popular para aliviar una variedad de dolencias. Contiene muchos fitoquímicos, algunos buenos para vos, otros no tanto. Entre esos químicos se encuentra la arbutina. La arbutina es un derivado de la hidroquina, presente en muchas plantas. Otros de sus nombres son arbutosido e hidroquinona β-D-glucopiranosido. Esto significa que encontramos una glucosa unida a la parte de hidroquinona de la molécula en un enlace “beta”. La…
October 20th, 2019 by Dr. Hannah Sivak
Note from Hannah: Loretta Donelan makes fun of people who buy skin care products because they trust the crazy advertising some companies use. Why am I posting her article? Because there is a lot of truth in there in the sense that most advertising is misleading or worse. On the other hand, I am one of the people who try very hard to make products that live up to the ideals (yes, ideals) of making human life better by producing products that actually help. So read the article and do the right thing: buy products not because of the advertising but because of the ingredients they contain. Honest Skin-Care-Product Reviews…
September 15th, 2019 by Dr. Hannah Sivak
Just as I explained in my post on avocado oil, the way to choose an oil for skin care is to look at its fatty acid composition. This is because we need certain fatty acids that are paramount for our skin health but, unfortunately, we can’t make them. They are essential fatty acids because we need to ingest them and apply them topically if we want our body to work the way it should. Figure: Rosa rubiginosa L. What is special about rosehip oil? While others may talk about its origin, I prefer to write about fatty acid composition. The rosehip is the fruit of the rose, and the oil…
September 8th, 2019 by Dr. Hannah Sivak
Human beings are by nature trusting — of people, technology, everything. Often, we’re too trusting, with tragic results. Science and medicine are very recent additions to human life. Yes, you may have heard about Greek “medicine” but it had no experimental basis, it only had the name. All that talk about the four “humors” (blood, phlegm, and yellow and black bile) did not help a single one of Hippocrates patients. The germ theory of illness is a recent arrival. Use of statistics in epidemiology is even more recent. My mother in the early 1950s (before the Salk vaccine), hoped that camphor would keep polio away. It didn’t. But as soon…
August 22nd, 2019 by Dr. Hannah Sivak
1. ¿Qué causa las manchas oscuras? Manchas oscuras: también conocidas como manchas por sol, manchas hepáticas, manchas de la edad. Suceden cuando el mecanismo (muy complicado) que debería darte un bronceado, sale mal. Producir un pigmento como la melanina bajo la influencia del sol tiene sentido: si vas a estar al sol, un pigmento que proteja la piel de un daño mayor es una buena solución. La próxima vez que estés al sol los rayos de alta energía provocarán menos daño porque los pigmentos en la piel le estarán dando algo de protección solar. El proceso para fabricar el pigmento y acumularlo en la piel es muy complejo e involucra…
August 22nd, 2019 by Dr. Hannah Sivak
Por cierto, los “tacos de apio” son una referencia oscura dedicada a las madres y abuelas de niños de 2 a 5 años que ven Wonder Pets en la television. Algunas plantas, como la lima, el limón, el apio y muchas otras, contienen sustancias químicas llamadas furocumarinas que absorben la radiación UV. Si un producto que contiene este químico se aplica a la piel, los rayos UV iniciarán una cadena de reacciones químicas que pueden dañar severamente la piel. La erupción inflamatoria fototóxica generalmente aparece 24 horas después de la exposición y alcanza su punto máximo dentro de las 48-72 horas. El eritema de ardor inicial es seguido por ampollas,…
May 25th, 2019 by Dr. Hannah Sivak
From https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0216362 Battle for the thermostat: Gender and the effect of temperature on cognitive performance Tom Y. Chang , Agne Kajackaite (2019) This paper studies differences in the effect of temperature on cognitive performance by gender in a large controlled lab experiment (N = 543). We study performance in math, verbal and cognitive reflection tasks and find that the effects of temperature vary significantly across men and women. At higher temperatures, women perform better on a math and verbal task while the reverse effect is observed for men. The increase in female performance in response to higher temperature is significantly larger and more precisely estimated than the corresponding decrease in…
May 23rd, 2019 by Dr. Hannah Sivak
Por Brett P. Giroir, Robert R. Redfield y Jerome M. Adams, 6 de marzo de 2019 Las vacunas salvan vidas, protegen a nuestros niños y son uno de nuestros mayores logros en salud pública. Como funcionarios de salud pública, nuestra función es promover la salud del pueblo estadounidense. Esto debe incluir la defensa de las vacunas. Enfermedades como la poliomielitis, el sarampión, la difteria y la rubéola fueron comunes en los Estados Unidos: afectaron a cientos de miles de bebés, niños y adultos, y mataron a miles de personas cada año. Algunos estadounidenses mayores pueden recordar el miedo asociado con los brotes de polio y la era de los pulmones…
April 30th, 2019 by Dr. Hannah Sivak
The Climate-Friendly Vegetable You Ought to Eat By Melissa Clark April 30, 2019 PORTLAND, Me. — It was a sharp, windy March day, but the gray water of Casco Bay glimmered green in the sun. On his lobster boat, the Pull N’ Pray, Justin Papkee scanned the surface of the ocean, searching for his buoys. But he wasn’t looking for lobster traps. Mr. Papkee was farming, not fishing: His crop, clinging to ropes beneath the cold waves, was seaweed, thousands of pounds of brownish kelp undulating under the surface. Growing at a rate of 4 to 6 inches per day for the past six months, it was nearly ready to…
April 14th, 2019 by Dr. Hannah Sivak
Why Facts Don’t Change Our Minds By Elizabeth Kolbert February 19, 2017. In 1975, researchers at Stanford invited a group of undergraduates to take part in a study about suicide. They were presented with pairs of suicide notes. In each pair, one note had been composed by a random individual, the other by a person who had subsequently taken his own life. The students were then asked to distinguish between the genuine notes and the fake ones. Some students discovered that they had a genius for the task. Out of twenty-five pairs of notes, they correctly identified the real one twenty-four times. Others discovered that they were hopeless. They identified…
March 1st, 2019 by Dr. Hannah Sivak
The composition of any product you apply to your skin or hair is always important. When is the time to re-examine your skin care products? If possible, when you start “trying”, even before you find out that you are actually pregnant. It is very important to examine carefully what you put in your body and what you apply to your body when you are pregnant. Because lactation continues the connection between your body and the body of your child, you will still have to remember to check the ingredients of your cosmetics after birth. First recommendation: if you are in doubt, ask your doctor: show him/her the ingredient list of…