Comment

Comment by Dr. Krishna Kumari Challa on December 29, 2020 at 9:11am

Gut cells sound the alarm when parasites invade

To effectively combat an infection, the body first has to sense it's been invaded, then the affected tissue must send out signals to corral resources to fight the intruder. Knowing more about these early stages of pathogen recognition and response may provide scientists with crucial clues when it comes to preventing infections or treating inflammatory diseases resulting from overactive immunity.

When scientists looked for the very first "danger" signals emitted by a host infected with the parasite, they traced them not to an immune cell, as might have been expected, but to epithelial cells lining the intestines, where Cryptosporidium sets up shop during an infection. Known as enterocytes, these cells take up nutrients from the gut, and here they were shown to alert the body to danger via the molecular receptor NLRP6, which is a component of what's known as the inflammasome.

You can think about the inflammasome as an alarm system in a house.

Earlier researchers have focused on immune cells, like macrophages and dendritic cells, as being the first to detect foreign invaders, but this new finding underscores that cells not normally thought of as part of the immune system—in this case intestinal epithelial cells—are playing key roles in how how an immune response gets launched.

There is a growing body of literature that is really appreciating what epithelial cells are doing to help the immune system sense pathogens. They seem to be a first line of defense against infection.

Adam Sateriale el al., "The intestinal parasite Cryptosporidium is controlled by an enterocyte intrinsic inflammasome that depends on NLRP6," PNAS (2020). www.pnas.org/cgi/doi/10.1073/pnas.2007807118

https://medicalxpress.com/news/2020-12-gut-cells-alarm-parasites-in...

Comment by Dr. Krishna Kumari Challa on December 28, 2020 at 9:16am

Anti-diarrhea drug drives cancer cells to cell death

Scientists two years ago found evidence indicating that the anti-diarrhea drug loperamide could be used to induce cell death in glioblastoma cell lines. They have now deciphered its mechanism of action and, in doing so, are opening new avenues for the development of novel treatment strategies.

In certain types of tumor cells, administration of loperamide leads to a stress response in the endoplasmic reticulum (ER), the cell organelle responsible for key steps in protein synthesis in the body. The stress in the ER triggers its degradation, followed by self-destruction of the cells. This mechanism, known as autophagy-dependent cell death occurs when cells undergo hyperactivated autophagy. Normally, autophagy regulates normal metabolic processes and breaks down and recycles the valuable parts of damaged or superfluous cell components thus ensuring the cell's survival, for example in the case of nutrient deficiency. In certain tumor cells, however, hyperactivation of autophagy destroys so much cell material that they are no longer capable of surviving.

The loperamide-induced death of glioblastoma cells could help in the development of new therapeutic approaches for the treatment of this severe form of cancer.

Svenja Zielke et al, ATF4 links ER stress with reticulophagy in glioblastoma cells, Autophagy (2020). DOI: 10.1080/15548627.2020.1827780

https://medicalxpress.com/news/2020-12-anti-diarrhea-drug-cancer-ce...

Comment by Dr. Krishna Kumari Challa on December 28, 2020 at 8:43am

New SARS-CoV-2 neutralizing antibody enters clinical phase

Cologne University Hospital (UKK), University of Marburg (UMR), the German Center for Infection Research (DZIF) and Boehringer Ingelheim announced the initiation of Phase 1/2a clinical investigation of BI 767551, a new SARS-CoV-2 neutralizing antibody. By combining UKK, UMR and DZIFs expertise in virology, immunology and clinical investigation with Boehringer Ingelheims expertise in developing and manufacturing therapeutic antibodies, the partners developed BI 767551 as a potential new therapeutic and preventive/prophylactic option for fighting COVID-19. Virus neutralizing antibodies are expected to become an important line of defense against SARS-CoV-2, complementing vaccines and nonpharmaceutical interventions. They are being investigated as a therapy option for individuals with mild or severe infections, but also as prevention or prophylaxis in non-infected people with a high risk of infection or at risk .

Comment by Dr. Krishna Kumari Challa on December 28, 2020 at 7:29am

10 times science made a sucky year suck less

Clapping seals, Great conjunction, COVID-19 vaccines, stink flirting...here's the amazing science of 2020.

https://www.livescience.com/10-times-science-made-sucky-year-suck-l...

--

Top science and technology achievements of India in 2020

http://timesofindia.indiatimes.com/articleshow/79825076.cms?utm_sou...

Comment by Dr. Krishna Kumari Challa on December 27, 2020 at 10:49am

Harnessing blood flow to navigate endovascular microrobots

Comment by Dr. Krishna Kumari Challa on December 27, 2020 at 10:04am

The first endovascular technology that can explore capillaries

 The cardiovascular system is astonishing. It uses the blood that circulates in our veins and arteries to transport oxygen and nutrients to every tissue in the body.

Researchers  have decided to harness hydrokinetic energy (mechanical energy resulting from the motion of liquids) to get to places in the human body without resorting to invasive methods. “Large proportions of the brain remain inaccessible because the existing tools are unwieldy, and exploring the tiny, intricate cerebral vascular system without causing tissue damage is extremely difficult.

Doctors can access patients’ arteries by pushing and rotating guidewires, and later sliding hollow tubes called catheters. However, when arteries begin to narrow, especially in the brain, this advancement technique reveals its limits. Scientists now engineered tethered microscopic devices that could be introduced into capillaries with unprecedented speed and ease. The devices consist of a magnetic tip and an ultraflexible body made of biocompatible polymers. Since no mechanical force is applied directly at the vessel wall, the risk of causing any damage is very low. Moreover, harnessing blood flow could reduce the operation time from several hours to a couple of minutes. Both the release of the device and magnetic steering are under computer control. Furthermore, there is no need for force feedback as the tip of the device does not push against the vessel walls. 

Researchers at EPFL’s School of Engineering tested the device inside artificial microvasculature systems. The next phase will involve tests on animals with state-of-the-art medical imaging systems. Scientists are also hoping to develop other devices with a range of on-board actuators and sensors.

https://actu.epfl.ch/news/the-first-endovascular-technology-that-ca...

https://researchnews.cc/news/4309/The-first-endovascular-technology...

Comment by Dr. Krishna Kumari Challa on December 26, 2020 at 9:22am

Putting The History Of Earth Into Perspective

Comment by Dr. Krishna Kumari Challa on December 26, 2020 at 9:04am

Breaking bad: How shattered chromosomes make cancer cells drug-resi...

Researchers recently described how a phenomenon known as chromothripsis breaks up chromosomes, which then reassemble in ways that ultimately promote cancer cell growth. Chromothripsis is a catastrophic mutational event in a cells history that involves massive rearrangement of its genome, as opposed to a gradual acquisition of rearrangements and mutations over time. Genomic rearrangement is a key characteristic of many cancers, allowing mutated cells to grow or grow faster, unaffected by anti-cancer  therepies.

These rearrangements can occur in a single step. During chromothripsis, a chromosome in a cell is shattered into many pieces, hundreds in some cases, followed by reassembly in a shuffled order. Some pieces get lost while others persist as extra-chromosomal DNA (ecDNA). Some of these ecDNA elements promote cancer cell growth and form minute-sized chromosomes called ‘double minutes.

Research found that up to half of all cancer cells in many types of cancers contain ecDNA carrying cancer-promoting genes. The scientists also identified how chromothripsis drives ecDNA formation after gene amplification inside a chromosome.

Chromothripsis converts intra-chromosomal amplifications (internal) into extra-chromosomal (external) amplifications and that amplified ecDNA can then reintegrate into chromosomal locations in response to DNA damage from chemotherapy or radiotherapy. The new work highlights the role of chromothripsis at all critical stages in the life cycle of amplified DNA in cancer cells, explaining how cancer cells can become more aggressive or drug-resistant.

https://health.ucsd.edu/news/releases/Pages/breaking-bad-how-shatte...

https://researchnews.cc/news/4292/Breaking-bad--How-shattered-chrom...

Comment by Dr. Krishna Kumari Challa on December 26, 2020 at 8:58am

https://actu.epfl.ch/news/when-light-and-atoms-share-a-common-vibe/

When light and atoms share a common vibe- explained below

**

When light and atoms share a common vibe

1. A laser generates a very short pulse of light 2. A fraction of this pulse is sent to a nonlinear device to change its color 3. The two laser pulses overlap on the same path again, creating a “write & read” pair of pulses. 4. Each pair is split into a short and a long path, 5. yielding an “early” and a “late” time slot, overlapping once again 6. Inside the diamond, during the “early” time slot, one photon from the “write” pulse may generate a vibration, while one photon from the “read” pulse converts the vibration back into light. 7. The same sequence may also happen during the “late” slot. But in this experiment, the scientists made sure that only one vibration is excited in total (in both early and late time slots). 8. By overlapping the photons in time again it becomes impossible to discriminate the early vs. late moment of the vibration. The vibration is now in a quantum superposition of early and late time. 9. In the detection apparatus, “write” and “read” photons are separated according to their different colors, and analyzed with single-photon counters to reveal their entanglement. Full article: https://actu.epfl.ch/news/when-light-...

Comment by Dr. Krishna Kumari Challa on December 26, 2020 at 8:56am

When light and atoms share a common vibe

An especially counter-intuitive feature of quantum mechanics is that a single event can exist in a state of superposition – happening both here and there, or both today and tomorrow.

Such superpositions are hard to create, as they are destroyed if any kind of information about the place and time of the event leaks into the surrounding – and even if nobody actually records this information. But when superpositions do occur, they lead to observations that are very different from that of classical physics, questioning down to our very understanding of space and time.

Scientists demonstrated a state of vibration that exists simultaneously at two different times, and evidence this quantum superposition by measuring the strongest class of quantum correlations between light beams that interact with the vibration.

The researchers used a very short laser-pulse to trigger a specific pattern of vibration inside a diamond crystal. Each pair of neighboring atoms oscillated like two masses linked by a spring, and this oscillation was synchronous across the entire illuminated region. To conserve energy during this process, a light of a new color is emitted, shifted toward the red of the spectrum.

This classical picture, however, is inconsistent with the experiments. Instead, both light and vibration should be described as particles, or quanta: light energy is quantized into discrete photons while vibrational energy is quantized into discrete phonons (named after the ancient Greek “photo = light” and “phono = sound”).

The process described above should therefore be seen as the fission of an incoming photon from the laser into a pair of photon and phonon – akin to nuclear fission of an atom into two smaller pieces.

But it is not the only shortcoming of classical physics. In quantum mechanics, particles can exist in a superposition state, like the famous Schrödinger cat being alive and dead at the same time.

Even more counterintuitive: two particles can become entangled, losing their individuality. The only information that can be collected about them concerns their common correlations. Because both particles are described by a common state (the wavefunction), these correlations are stronger than what is possible in classical physics. It can be demonstrated by performing appropriate measurements on the two particles. If the results violate a classical limit, one can be sure they were entangled.

In the new study, EPFL researchers managed to entangle the photon and the phonon (i.e., light and vibration) produced in the fission of an incoming laser photon inside the crystal. To do so, the scientists designed an experiment in which the photon-phonon pair could be created at two different instants. Classically, it would result in a situation where the pair is created at time t1 with 50% probability, or at a later time t2 with 50% probability.

But here comes the “trick” played by the researchers to generate an entangled state. By a precise arrangement of the experiment, they ensured that not even the faintest trace of the light-vibration pair creation time (t1 vs. t2) was left in the universe. In other words, they erased information about t1 and t2. Quantum mechanics then predicts that the phonon-photon pair becomes entangled, and exists in a superposition of time t1andt2. This prediction was beautifully confirmed by the measurements, which yielded results incompatible with the classical probabilistic theory.

By showing entanglement between light and vibration in a crystal that one could hold in their finger during the experiment, the new study creates a bridge between our daily experience and the fascinating realm of quantum mechanics.

https://researchnews.cc/news/4299/When-light-and-atoms-share-a-comm...

• ‹ Previous
• 1
• …
• 462
• 463
• 464
• 465
• 466
• …
• 845
• Next ›
• Page