Even After Someone Is Declared Dead, Life Continues In The Body, Suggests A Surprising New Study With

Thyroid function tests

Standard Tests

TSH levels

Free T4 (fT4) levels

Measurements of total T4 + T3 used to be common however detects both bound and free T3 + T4

Elevated total T4 may occur in healthy individuals if there is an increase in binding protein concentrations

Reliable tests now exist for free T4 + T3

T3 = 3.9-6.7 pmol/L

T4 = 12-22 pmol/L

Thyroid-stimulating hormone

Produced by the pituitary gland, not the thyroid, however:

TSH levels are controlled by negative feedback – can be indication of thyroid function (changes in T3+T4 will result in changes in TSH to try compesate)

TSH levels greatly elevated in hypothyroidism – >10 fold increase over reference values

More sensitive marker than decreased fT4 - increased TSH occurs before fT4 decreases

TSH levels greatly supressed in hyperthyroidism

Low concentrations can also occur in non-thyroidal illness

TSH measurement is the first-line test of thyroid function.

Free T4 + T3 Measurements

Desirable as free hormone is clinically relevant

Total levels can change under conditions that alter thyroxine-binding globulin (TBG) levels e.g. pregnancy

Large changes in TBG may still affect fT4 + fT3 levels

fT3 levels often normal in hypothyroidism

fT3 levels usually raised more than fT4 levels in hyperthyroidism

Unless complicated by an illness effecting conversion of T4 to T3

Therefore: – fT4 levels are a better indication of hypothyroidism

fT3 levels are a better indication of hyperthyroidism

COLORS OF CHEMISTRY

The bright colors of chemistry fascinate people of all ages. Hriday Bhattacharjee, a Ph.D. student in the lab of Jens Mueller at the University of Saskatchewan, assembled this showcase from compounds he prepared as well as from some synthesized by the undergraduate students he teaches. Organometallic and inorganic chemistry—the study of molecules like these that involve metal atoms—is especially colorful.

The table below the picture indicates the chemicals seen in the photo.

Submitted by Hriday Bhattacharjee

Do science. Take pictures. Win money: Enter our photo contest.

Largest Batch of Earth-size, Habitable Zone Planets

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

More ‪#‎WorldChocolateDay‬ chemistry: this time with C&EN, looking at dark chocolate, milk chocolate, and white ‘chocolate’: ow.ly/ugB93021z64

Steve Gentleman, a neuropathologist, demonstrates the process of brain dissection and preservation for research. 

This Week in Chemistry: The chemical cause of Russia’s red river, a possible alternative to plastic microbeads in soaps, and more! Links to articles and studies here: https://goo.gl/wPQ5ym

It’s time for #TrilobiteTuesday! During their lengthy trek through time, trilobites existed in an almost dizzying array of sizes and shapes. Perhaps no other creature in the entire history of the earth has ever displayed the diversity of design shown by these singularly distinctive arthropods. But at their heart (and yes, trilobites apparently did possess primitive but effective cardio-respiratory systems), they were all remarkably similar. Named not, as is generally surmised, for their three main body segments – cephalon (head), thorax (body) and pygidium (tail) – but rather for the three lobes that longitudinally divided their dorsal exoskeleton. Whether they were Cambrian Olenellids – such as this Olenellus romensis from Alabama – or Devonian Phacopids, most trilobites presented a fundamentally analogous body design. Such characteristics as occipital lobes, anterior margins and facial sutures (which allowed early trilobites to shed their molting shell), were shared by the majority of trilobite species, as were such exotic-sounding features as axial rings, articulating facets and pleural spines. 

A Brand-New Human Organ Has Been Identified

Your body now has an extra organ — meet the mesentery.

A mighty membrane that twists and turns through the gut is starting the new year with a new classification: the structure, called the mesentery, has been upgraded to an organ.

Scientists have known about the structure, which connects a person’s small and large intestines to the abdominal wall and anchors them in place, according to the Mayo Clinic. However, until now, it was thought of as a number of distinct membranes by most scientists. Interestingly, in one of its earliest descriptions, none other than Leonardo da Vinci identified the membranes as a single structure, according to a recent review.