8000 kilometers per second: Star with the Shortest Orbital Period around Black Hole discovered

Researchers at the University of Cologne and Masaryk University in Brno (Czech Republic) have discovered the fastest known star, which travels around a black hole in record time. The star, S4716, orbits SagittariusA*, the black hole in the centre of our Milky Way, in four years and reaches a speed of around 8000 kilometres per second. S4716 comes as close as 100 AU (astronomical unit) to the black hole — a small distance by astronomical standards. One AU corresponds to 149,597,870 kilometres. The study has been published in The Astrophysical Journal.

In the vicinity of the black hole at the centre of our galaxy is a densely packed cluster of stars. This cluster, called S cluster, is home to well over a hundred stars that differ in their brightness and mass...

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Shedding light on Comet Chury’s unexpected Chemical Complexity

Data from comet “Chury”, collected while the comet passed the point of its orbit closest to the Sun, show a plethora of surprising molecules sublimating from expelled dust particles. On average, this complex organic material resembles that present in meteorites and Saturn’s ring rain, indicating a shared presolar origin.© Universtiy of Bern

Researchers have for the first time identified an unexpected richness of complex organic molecules on a comet. This was achieved thanks to the analysis of data collected during ESA’s Rosetta mission at comet 67P/Churyumov-Gerasimenko, also known as Chury. Delivered to the early Earth by impacting comets, these organics may have helped to kick-start carbon-based life as we know it.

Comets are fossils from the ancient times and from the dept...

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Scientists discover key to Hepatitis A Virus Replication, show Drug Effectiveness

Fluorescence microscopy image of HAV-infected cultured human liver cell. viral RNA targeted by ZCCHC14 appears green, and the virus’s protein red. (Credit: Maryna Kapustina, PhD)

The viral replication cycle is crucial for a virus to spread inside the body and cause disease. Focusing on that cycle in the hepatitis A virus (HAV), UNC School of Medicine scientists discovered that replication requires specific interactions between the human protein ZCCHC14 and a group of enzymes called TENT4 poly(A) polymerases. They also found that the oral compound RG7834 stopped replication at a key step, making it impossible for the virus to infect liver cells.

These findings, published in the Proceedings of the National Academy of Sciences, are the first to demonstrate an effective drug treatment...

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Signaling Molecule potently Stimulates Hair Growth

Hedgehog signaling in murine fibroblasts induces new hair growth and hair multiplication
•Hedgehog activation increases fibroblast heterogeneity and drives new cell states
•TGF-β pathway downstream of dermal Hedgehog mediates hair growth hyper-activation
•SCUBE3 is a new mesenchymal niche factor that activates hair growth

SCUBE3 identified as possible therapeutic treatment for androgenetic alopecia. University of California, Irvine-led researchers have discovered that a signaling molecule called SCUBE3 potently stimulates hair growth and may offer a therapeutic treatment for androgenetic alopecia, a common form of hair loss in both women and men.

The study, published online today in Developmental Cell, determined the precise mechanism by which the dermal papilla cells — speciali...

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