Comment

Comment by Dr. Krishna Kumari Challa on December 2, 2023 at 10:23am

New research suggests cellular stress in the placenta may be possible cause of preeclampsia

Preeclampsia is a mysterious condition that occurs in about one of 10 pregnancies without any early warning signs. After 20 weeks or more of normal blood pressure during the pregnancy, patients with preeclampsia will begin to experience elevated blood pressure and may also have increased levels of protein in their urine due to hypertension reducing the filtering power of the kidneys. Prolonged hypertension due to preeclampsia can lead to organ damage and life-threatening complications for mothers and fetuses.

There is no cure for the underlying causes of preeclampsia, so physicians focus on managing and monitoring patients' blood pressure to allow for as close to a full-term gestation as possible. With severe disease, pre-term deliveries are necessary.

For those who get it earlier on, it can be terrifying and life-changing, potentially including a long hospital stay before delivery and significant supportive care for the infant in the NICU afterwards.

Now scientists have published results on a study of one of the emerging theories for what causes preeclampsia in Science Advances.

The experiments focus on a particular layer of cells of the placenta called the syncytiotrophoblast (STB), which is a key part of the barrier between the mother and developing fetus. This blockade helps keep a mother's fully formed immune system from reacting to the fetus and potentially responding as if the fetus was a foreign threat such as a viral or bacterial invader.

The barrier also works in reverse to keep the fetus's growing immune system from reacting to its mother's cells and tissues. The study's authors investigated the hypothesis that an abnormal amount of cellular and molecular stresses to the STB can damage the placenta and lead to preeclampsia.

Part 1

Comment by Dr. Krishna Kumari Challa on December 2, 2023 at 9:36am

As dengue expands beyond the global 'dengue belt,' scientists dispel conventional wisdom about the disease

Unknowns, dangers and surprises persist about dengue viral infection and now an assumption once accepted as conventional wisdom about immunity to the mosquito-borne disease may be incorrect.

Dengue is a devastating viral infection transmitted to humans through the bite of Aedes aegypti mosquitoes—flying hypodermic needles that descend prolifically during significant outbreaks. Many dengue epidemics tend to occur in urban settings, scientists say. Dengue viral infection can cause a severe headache, high fever, nausea, vomiting, swollen glands, and rash. Still, and perhaps most surprisingly, many people who are infected have no symptoms at all. In rare cases, however, dengue disease can be fatal.

New research involving epidemiological models and data from more than 4,400 people in Nicaragua suggests that it's time immunologists developed a new framework to understand population immunity to dengue. For decades, it was believed that once you were infected with dengue virus, the immunity lasted for life. The dogma persisted in the face of observational data, which found that people who were previously infected were more susceptible to severe dengue if infected again.

But an international collaborative group of researchers has now conclusively shown that immunity not only wanes, it tends to wax and wane—a discovery that reveals dengue infection to be far more complex than previously thought.

According to them, Infection with multiple dengue virus serotypes is thought to induce enduring protection against dengue disease. However, long-term antibody waning has been observed after repeated dengue infection. The waning of antibodies inevitably was followed by a boosting of antibodies when the next epidemic came along.

This discovery allowed the construction of a new model that best describes population vulnerability to dengue infection, especially amid the known periodicity—the cyclic nature—of dengue outbreaks.

When it comes to dengue, people are not permanently immune but susceptible to infection, then immune and ultimately susceptible again. Hence, the researchers  newly proposed a model: "susceptible-infected-recovered-susceptible."

Rosemary A. Aogo et al, Effects of boosting and waning in highly exposed populations on dengue epidemic dynamics, Science Translational Medicine (2023). DOI: 10.1126/scitranslmed.adi1734

Comment by Dr. Krishna Kumari Challa on December 1, 2023 at 12:18pm

Brain waves usually found in sleep can protect against epileptic activity

Slow waves that usually only occur in the brain during sleep are also present during wakefulness in people with epilepsy and may protect against increased brain excitability associated with the condition, finds a new study by researchers.

The researchers examined electroencephalogram (EEG) scans from electrodes in the brains of 25 patients with focal epilepsy (a type of epilepsy characterized by seizures arising from a specific part of the brain), while they carried out an associative memory task.

The electrodes had been placed in the patients' brains to localize abnormal activity and inform surgical treatment.

During the task, participants were presented with 27 pairs of images that remained on a screen for six seconds. The images were in nine groups of three—each group featuring a picture of a person, a place and an object. In each case, participants had to remember which images had been grouped together. EEG data were recorded continuously throughout the task.

After reviewing the EEG data, the team found that the brains of people with epilepsy were producing slow waves—lasting less than one second—while they were awake and taking part in the task.

The occurrence of these "wake" slow waves increased in line with increases in brain excitability and decreased the impact of epileptic spikes on brain activity.

In particular, there was a decrease in the "firing" of nerve cells, which the researchers say could protect against epileptic activity.

Wake slow waves in focal human epilepsy impact network activity and cognition, Nature Communications (2023). DOI: 10.1038/s41467-023-42971-3

Comment by Dr. Krishna Kumari Challa on December 1, 2023 at 11:51am

A mineral produced by plate tectonics has a global cooling effect, study finds

Geologists have found that a clay mineral on the seafloor, called smectite, has a surprisingly powerful ability to sequester carbon over millions of years.

Under a microscope, a single grain of the clay resembles the folds of an accordion. These folds are known to be effective traps for organic carbon. 

Now, the researchers have shown that the carbon-trapping clays are a product of plate tectonics: When oceanic crust crushes against a continental plate, it can bring rocks to the surface that, over time, can weather into minerals including smectite. Eventually, the clay sediment settles back in the ocean, where the minerals trap bits of dead organisms in their microscopic folds. This keeps the organic carbon from being consumed by microbes and expelled back into the atmosphere as carbon dioxide.

Over millions of years, smectite can have a global effect, helping to cool the entire planet. Through a series of analyses, the researchers showed that smectite was likely produced after several major tectonic events over the last 500 million years. During each tectonic event, the clays trapped enough carbon to cool the Earth and induce the subsequent ice age.

The findings are the first to show that plate tectonics can trigger ice ages through the production of carbon-trapping smectite.

"Palaeozoic cooling modulated by ophiolite weathering through organic carbon preservation", Nature Geoscience (2023). DOI: 10.1038/s41561-023-01342-9

Comment by Dr. Krishna Kumari Challa on November 30, 2023 at 1:08pm

Reducing fatal bird collisions

Comment by Dr. Krishna Kumari Challa on November 30, 2023 at 11:17am

Nanodiamonds can block tumor metastasis in mice, study shows

Nanodiamonds are 2–8 nm carbon nanoparticles, which can be easily functionalized with various chemical groups like carboxylic groups or drugs. Previous research has shown that actively dividing cells are more likely to absorb nanodiamonds and that epithelial cells treated with carboxylic nanodiamonds lose the ability to migrate across cell-permeable cellulose membranes.

Researchers explored whether nanodiamonds might block tumor metastasis, a process that requires cell migration to new areas. The research is published in the journal PNAS Nexus. 

The authors treated B16F10 melanoma cells with carboxylic nanodiamonds in culture and tested their ability to migrate and invade across polycarbonate membranes with 8-µm pores. The authors found that the nanodiamonds blocked the ability of melanoma cells to migrate, while untreated tumor cells were able to pass through the membrane.

Based on gene expression evidence, the authors hypothesize that the tiny carbon nanodiamonds may inhibit the breaking away of cancer cells from the primary tumor mass—as well as block subsequent steps of metastasis such as the physical movement of cells and their ability to enter blood vessels.

According to the authors, nanodiamonds should be further explored as a possible therapeutic agent for cancer metastasis.

 Sushreesangita P Behera et al, Carboxyl nanodiamonds inhibit melanoma tumor metastases by blocking cellular motility and invasiveness, PNAS Nexus (2023). DOI: 10.1093/pnasnexus/pgad359

Comment by Dr. Krishna Kumari Challa on November 30, 2023 at 11:12am

Scientists discover rare six-planet system that moves in strange synchrony

Scientists have discovered a rare sight in a nearby star system: Six planets orbiting their central star in a rhythmic beat. The planets move in an orbital waltz that repeats itself so precisely that it can be readily set to music.

A rare case of an "in sync" gravitational lockstep, the system could offer deep insight into planet formationand evolution.

The analysis, led by UChicago scientist Rafael Luque, was published Nov. 29 in Nature.

The six planets orbit a star known as HD110067, which lies around 100 light-years away in the northern constellation of Coma Berenices.

In 2020, NASA's Transiting Exoplanet Survey Satellite (TESS) detected dips in the star's brightness that indicated planets were passing in front of the star's surface. Combining data from both TESS and the European Space Agency's CHaracterizing ExOPlanet Satellite (Cheops), a team of researchers analyzed the data and discovered a first-of-its-kind configuration.

While multi-planet systems are common in our galaxy, those in a tight gravitational formation known as "resonance" are observed by astronomers far less often.

In this case, the planet closest to the star makes three orbits for every two of the next planet out—called a 3/2 resonance—a pattern that is repeated among the four closest planets. Among the outermost planets, a pattern of four orbits for every three of the next planet out (a 4/3 resonance) is repeated twice.

And these resonant orbits are rock-solid: The planets likely have been performing this same rhythmic dance since the system formed billions of years ago, the scientists said.

Orbitally resonant systems are extremely important to find because they tell astronomers about the formation and subsequent evolution of the planetary system. Planets around stars tend to form in resonance but can be easily perturbed. For example, a very massive planet, a close encounter with a passing star, or a giant impact event can all disrupt the careful balance.

As a result, many of the multi-planet systems known to astronomers are not in resonance but look close enough that they could have been resonant once. However, multi-planet systems preserving their resonance are rare.

Rafael Luque, A resonant sextuplet of sub-Neptunes transiting the bright star HD 110067, Nature (2023). DOI: 10.1038/s41586-023-06692-3. www.nature.com/articles/s41586-023-06692-3

Comment by Dr. Krishna Kumari Challa on November 29, 2023 at 12:48pm

Meta AI develops a non-invasive method to decode speech from brain activity

Recent technological advancements have opened invaluable opportunities for assisting people who are experiencing impairments or disabilities. For instance, they have enabled the creation of tools to support physical rehabilitation, to practice social skills, and to provide daily assistance with specific tasks.

Recent technological advancements have opened invaluable opportunities for assisting people who are experiencing impairments or disabilities. For instance, they have enabled the creation of tools to support physical rehabilitation, to practice social skills, and to provide daily assistance with specific tasks. Researchers at Meta AI recently developed a promising and non-invasive method to decode speech from a person's brain activity, which could allow people who are unable to speak to relay their thoughts via a computer interface. Their proposed method, presented in Nature Machine Intelligence, merges the use of an imaging technique and machine learning.

Alexandre Défossez et al, Decoding speech perception from non-invasive brain recordings, Nature Machine Intelligence (2023). DOI: 10.1038/s42256-023-00714-5.

Comment by Dr. Krishna Kumari Challa on November 28, 2023 at 12:22pm

How to make waves eat themselves
Physicists have demonstrated that two cavities carved into the side of a channel can totally dissipate the energy of incoming waves. In a model set-up with real water, researchers were able to achieve ‘perfect absorption’ — in which the waves completely cancelled themselves out as they bounced off the cavity walls — with waves of a frequency of 2.9 Hertz. The finding hints at the possibility of designing structures to protect coastlines or harvest wave energy.

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.131.204002

Comment by Dr. Krishna Kumari Challa on November 28, 2023 at 12:21pm

Chocolate discharges the same chemical in your body as when you feel love.
Chocolate raises levels of phenylethylamine (PEA), “the love chemical”. This chemical gets our hearts pumping, increases blood pressure, heart, and respiratory rates, and increases feelings of joy
Chocolate releases this neurochemical of pleasure in our brains. Dopamine kick starts a brain messenger chemical called DARP-32 that activates hormones. This is the chemical that surges through us when we are embraced by someone we love.
Chocolate contains tryptophan, a precursor to serotonin. Serotonin is our other feel good chemical. It diminishes anxiety and increases our ability to fight stress. Many antidepressants work by increasing serotonin levels.
So those who are not in love go eat chocolates and be happy.

• ‹ Previous
• 1
• …
• 305
• 306
• 307
• 308
• 309
• …
• 1079
• Next ›
• Page