Hepatitis B in a Laboratory!! #serology #infection #liver #hepatitis #medicine #medstudent #medstudynotes #virus #medschool #microbiology #pathology https://www.instagram.com/p/BrIYa-LheyH/?utm_source=ig_tumblr_share&igshid=lqm0j92yobw0
If you dropped a water balloon on a bed of nails, you’d expect it to burst spectacularly. And you’d be right – some of the time. Under the right conditions, though, you’d see what a high-speed camera caught in the animation above: a pancake-shaped bounce with nary a leak. Physically, this is a scaled-up version of what happens to a water droplet when it hits a superhydrophobic surface.
Water repellent superhydrophobic surfaces are covered in microscale roughness, much like a bed of tiny nails. When the balloon (or droplet) hits, it deforms into the gaps between posts. In the case of the water balloon, its rubbery exterior pulls back against that deformation. (For the droplet, the same effect is provided by surface tension.) That tension pulls the deformed parts of the balloon back up, causing the whole balloon to rebound off the nails in a pancake-like shape. For more, check out this video on the student balloon project or the original water droplet research. (Image credits: T. Hecksher et al., Y. Liu et al.; via The New York Times; submitted by Justin B.)
WATCH: A Macro Timelapse Highlights the Micro Movements of Spectacularly Colored Coral [video]
Ada Lovelace Day is an international celebration of the achievements of women in science, technology, engineering, math, and all related STEM fields.
The celebration is named in honor of English mathematician Augusta Ada King (1815-1852), Countess of Lovelace, known colloquially as Ada Lovelace. Lovelace, the daughter of Lord Byron, is sometimes considered the world’s first computer programmer for the algorithm she wrote for Charles Babbage’s analytical engine, one of the world’s first mechanical computers. Over the years there have been historical disagreements over the extent of Lovelace’s knowledge of the subject and the originality of the work she published in her article, “Sketch of the Analytical Engine, with Notes from the Translator,“ but Babbage himself seemed to dismiss such future claims in his memoir.
Check out the collection Science NetLinks put together for Women’s History Month for related resources to help all students understand the role women historically have played in the history of STEM development and those they play in current STEM fields.
Learn more.
Image Credit: Alfred Edward Chalon [Public domain], via Wikimedia Commons
Our Spitzer Space Telescope has revealed the first known system of seven Earth-size planets around a single star. Three of these planets are firmly located in an area called the habitable zone, where liquid water is most likely to exist on a rocky planet.
This exoplanet system is called TRAPPIST-1, named for The Transiting Planets and Planetesimals Small Telescope (TRAPPIST) in Chile. In May 2016, researchers using TRAPPIST announced they had discovered three planets in the system.
Assisted by several ground-based telescopes, Spitzer confirmed the existence of two of these planets and discovered five additional ones, increasing the number of known planets in the system to seven.
This is the FIRST time three terrestrial planets have been found in the habitable zone of a star, and this is the FIRST time we have been able to measure both the masses and the radius for habitable zone Earth-sized planets.
All of these seven planets could have liquid water, key to life as we know it, under the right atmospheric conditions, but the chances are highest with the three in the habitable zone.
At about 40 light-years (235 trillion miles) from Earth, the system of planets is relatively close to us, in the constellation Aquarius. Because they are located outside of our solar system, these planets are scientifically known as exoplanets. To clarify, exoplanets are planets outside our solar system that orbit a sun-like star.
In this animation, you can see the planets orbiting the star, with the green area representing the famous habitable zone, defined as the range of distance to the star for which an Earth-like planet is the most likely to harbor abundant liquid water on its surface. Planets e, f and g fall in the habitable zone of the star.
Using Spitzer data, the team precisely measured the sizes of the seven planets and developed first estimates of the masses of six of them. The mass of the seventh and farthest exoplanet has not yet been estimated.
For comparison…if our sun was the size of a basketball, the TRAPPIST-1 star would be the size of a golf ball.
Based on their densities, all of the TRAPPIST-1 planets are likely to be rocky. Further observations will not only help determine whether they are rich in water, but also possibly reveal whether any could have liquid water on their surfaces.
The sun at the center of this system is classified as an ultra-cool dwarf and is so cool that liquid water could survive on planets orbiting very close to it, closer than is possible on planets in our solar system. All seven of the TRAPPIST-1 planetary orbits are closer to their host star than Mercury is to our sun.
The planets also are very close to each other. How close? Well, if a person was standing on one of the planet’s surface, they could gaze up and potentially see geological features or clouds of neighboring worlds, which would sometimes appear larger than the moon in Earth’s sky.
The planets may also be tidally-locked to their star, which means the same side of the planet is always facing the star, therefore each side is either perpetual day or night. This could mean they have weather patterns totally unlike those on Earth, such as strong wind blowing from the day side to the night side, and extreme temperature changes.
Because most TRAPPIST-1 planets are likely to be rocky, and they are very close to one another, scientists view the Galilean moons of Jupiter – lo, Europa, Callisto, Ganymede – as good comparisons in our solar system. All of these moons are also tidally locked to Jupiter. The TRAPPIST-1 star is only slightly wider than Jupiter, yet much warmer.
How Did the Spitzer Space Telescope Detect this System?
Spitzer, an infrared telescope that trails Earth as it orbits the sun, was well-suited for studying TRAPPIST-1 because the star glows brightest in infrared light, whose wavelengths are longer than the eye can see. Spitzer is uniquely positioned in its orbit to observe enough crossing (aka transits) of the planets in front of the host star to reveal the complex architecture of the system.
Every time a planet passes by, or transits, a star, it blocks out some light. Spitzer measured the dips in light and based on how big the dip, you can determine the size of the planet. The timing of the transits tells you how long it takes for the planet to orbit the star.
The TRAPPIST-1 system provides one of the best opportunities in the next decade to study the atmospheres around Earth-size planets. Spitzer, Hubble and Kepler will help astronomers plan for follow-up studies using our upcoming James Webb Space Telescope, launching in 2018. With much greater sensitivity, Webb will be able to detect the chemical fingerprints of water, methane, oxygen, ozone and other components of a planet’s atmosphere.
At 40 light-years away, humans won’t be visiting this system in person anytime soon…that said…this poster can help us imagine what it would be like:
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
The new work at The Franklin Institute may be the most complex and detailed artistic depiction of the brain ever.
Your brain has approximately 86 billion neurons joined together through some 100 trillion connections, giving rise to a complex biological machine capable of pulling off amazing feats. Yet it’s difficult to truly grasp the sophistication of this interconnected web of cells.
Now, a new work of art based on actual scientific data provides a glimpse into this complexity.
The 8-by-12-foot gold panel, depicting a sagittal slice of the human brain, blends hand drawing and multiple human brain datasets from several universities. The work was created by Greg Dunn, a neuroscientist-turned-artist, and Brian Edwards, a physicist at the University of Pennsylvania, and goes on display at The Franklin Institute in Philadelphia.
“The human brain is insanely complicated,” Dunn said. “Rather than being told that your brain has 80 billion neurons, you can see with your own eyes what the activity of 500,000 of them looks like, and that has a much greater capacity to make an emotional impact than does a factoid in a book someplace.”
To reflect the neural activity within the brain, Dunn and Edwards have developed a technique called micro-etching: They paint the neurons by making microscopic ridges on a reflective sheet in such a way that they catch and reflect light from certain angles. When the light source moves in relation to the gold panel, the image appears to be animated, as if waves of activity are sweeping through it.
First, the visual cortex at the back of the brain lights up, then light propagates to the rest of the brain, gleaming and dimming in various regions — just as neurons would signal inside a real brain when you look at a piece of art.
That’s the idea behind the name of Dunn and Edwards’ piece: “Self Reflected.” It’s basically an animated painting of your brain perceiving itself in an animated painting.
To make the artwork resemble a real brain as closely as possible, the artists used actual MRI scans and human brain maps, but the datasets were not detailed enough. “There were a lot of holes to fill in,” Dunn said. Several students working with the duo explored scientific literature to figure out what types of neurons are in a given brain region, what they look like and what they are connected to. Then the artists drew each neuron.
Dunn and Edwards then used data from DTI scans — a special type of imaging that maps bundles of white matter connecting different regions of the brain. This completed the picture, and the results were scanned into a computer. Using photolithography, the artists etched the image onto a panel covered with gold leaf.
“A lot of times in science and engineering, we take a complex object and distill it down to its bare essential components, and study that component really well” Edwards said. But when it comes to the brain, understanding one neuron is very different from understanding how billions of neurons work together and give rise to consciousness.
“Of course, we can’t explain consciousness through an art piece, but we can give a sense of the fact that it is more complicated than just a few neurons,” he added.
The artists hope their work will inspire people, even professional neuroscientists, “to take a moment and remember that our brains are absolutely insanely beautiful and they are buzzing with activity every instant of our lives,” Dunn said. “Everybody takes it for granted, but we have, at the very core of our being, the most complex machine in the entire universe.”
Image 1: A computer image of “Self Reflected,” an etching of a human brain created by artists Greg Dunn and Brian Edwards.
Image 2: A close-up of the cerebellum in the finished work.
Image 3: A close-up of the motor cortex in the finished work.
Image 4: This is what “Self Reflected” looks like when it’s illuminated with all white light.
Image 5: Pons and brainstem close up.
Image 6: Putkinje neurons - color encodes reflective position in microetching.
Image 7: Primary visual cortex in the calcarine fissure.
Image 8: Basal ganglia and connected circuitry.
Image 9: Parietal cortex.
Image 10: Cerebellum.
Source: The Huffington Post (by Bahar Gholipour)
This year’s Halloween special wraps up the chemistry behind making a mummy: http://wp.me/p4aPLT-26m
The liver is supplied with blood by the hepatic artery and the hepatic portal vein
branches of the hepatic artery and the hepatic portal vein distribute blood to the periphery of the liver lobules.
Blood passes along sinusoids, which are lined by hepatocytes, which perform numerous metabolic and synthetic functions.
The processed blood passes into branches of the hepatic vein in the centre of each lobule, and eventually drains into the hepatic vein.
The biliary system is independent of the vascular system and bile moves in the opposite direction to the blood.
Initially it is collected in bile ductules which are surrounded by collagenous tissue, which forms part of the collagenous trabecular septum.
The bile is collected by increasingly large trabecular ducts, which fuse to form intrahepatic ducts which finally drain into the main hepatic ducts.
Astronomers at the University of Minnesota Duluth and the North Carolina Museum of Natural Sciences have identified a new class of ring galaxy. Named PGC 1000714, it features an elliptical core with not one, but two outer rings. It’s the only known galaxy of its kind in the known universe.
One of the smoothest, most beautiful color changes I’ve ever seen.
The reaction is methoxymethyl deprotection of one of my agonists with concentrated HCl in acetonitrile as my solvent. The color change doesn’t happen in THF!
Professor Rebecca Saxe (MIT) has taken the first ever MR image of a mother and child.
“This picture is an MR image of a mother and a child that I made in my lab at MIT. You might see it as sweet and touching… an image of universal love. We can’t see clothes or hairstyles or even skin colour. From what we do see, the biology and the brains, this could be any mother and child or even father and child at any time and place in history; having an experience that any human can recognise.
Or you might see it as disturbing, a reminder that our human bodies are much too fragile as houses for ourselves. MRI’s are usually medical images and often bad news. Each white spot in that picture is a blood vessel that could clog, each tiny fold of those brains could harbour a tumour. The baby’s brain maybe looks particularly vulnerable pressed against the soft thin shell of its skull.
I see those things, universal emotions and frightening fragility but I also see one of the most amazing transformations in biology.”
Quotes have been taken from a TEDx talk given by Professor Saxe explaining the story behind the above picture.
A pharmacist and a little science sideblog. "Knowledge belongs to humanity, and is the torch which illuminates the world." - Louis Pasteur
215 posts