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Comment by Dr. Krishna Kumari Challa on December 29, 2021 at 9:37am

The Final moments: Brain Death and the process of stopping it

For years, scientists have researched what happens to your brain when you die, but despite everything we've found out, progress has been stymied by an inability to easily monitor human death – since physicians are conventionally obliged to prevent death if they can, not monitor it as it takes hold. What this means is most of our understanding of the processes involved in brain death come from animal experiments, strengthened with what we can glean from the accounts of resuscitated patients disclosing their near-death experiences. But in 2018, an international team of scientists made a breakthrough. In animals, within 20 to 40 seconds of oxygen deprivation, the brain enters an 'energy-saving mode' where it becomes electrically inactive and neurons cease communicating with one another. After a few minutes, the brain begins to break down as ion gradients in cells dissipate, and a wave of electrochemical energy – called a spreading depolarisation (or 'brain tsunami') spreads throughout the cortex and other brain regions, ultimately causing irreversible brain damage.

A team of neurologists  – who monitored these processes taking place in nine patients with devastating brain injuries (under Do Not Resuscitate – Comfort Care orders) – say the tsunami of brain death may actually be capable of being stopped.

After circulatory arrest, spreading depolarisation marks the loss of stored electrochemical energy in brain cells and the onset of toxic processes that eventually lead to death. But it is reversible – up to a point – when the circulation is restored.

Using neuro-monitoring technology called subdural electrode strips and intraparenchymal electrode arrays, the researchers monitored spreading depolarisation in the patients' brains, and they suggest it's not a one-way wave – as long as circulation (and thus oxygen supply) can be resumed to the brain.

"Anoxia-triggered [spreading depolarisation] is fully reversible without any signs of cellular damage, if the oxidative substrate supply is re-established before the so-called commitment point, defined as the time when neurons start dying under persistent depolarisation. For patients at risk of brain damage or death incurred through cerebral ischemia or other kinds of stroke, the findings could one day be a life-saver, although the researchers explain a lot more work is needed before physicians will be able to take advantage of these discoveries.

https://onlinelibrary.wiley.com/doi/full/10.1002/ana.25147

https://www.sciencealert.com/death-bringing-brain-tsunamis-have-bee...

Comment by Dr. Krishna Kumari Challa on December 29, 2021 at 8:10am

Quantum Computers, Explained With Quantum Physics

Comment by Dr. Krishna Kumari Challa on December 28, 2021 at 11:49am

The microneedles themselves are made of a non-degradable, biocompatible hydrogel that also contains zwitterionic poly-sulfobetaine (poly-SPB). As reported in previous studies by the same authors, this polymer suppresses protein aggregation. Thus, the researchers incorporated it during the fabrication process and showed that the proteins pre-loaded in the microneedles were stable even when subjected to various external stresses.

Additionally, the scientists developed a straightforward and cost-effective way to fabricate microneedle arrays made from the abovementioned materials. They resorted to photolithography, a process in which a photomask is used to selectively block UV light from reaching a target surface to control chemical reactions locally.

To test the performance of these microneedle arrays for drug delivery, the researchers loaded them with 50 microliters of drug solutions containing rhodamine B as a dye alongside lysozyme and insulin as example proteins. Through various experiments on porcine skin, the teams verified that their microneedle patches offered both high drug-loading capacity and high drug-release rate. Moreover, they confirmed that the microneedles could both load and preserve various water-soluble drugs and proteins simultaneously, eliminating the need for refrigeration.

Overall, the proposed microneedle arrays seem to be a remarkably promising platform for administering therapeutic drugs and vaccines.

Harit Pitakjakpipop et al, Facile Photolithographic Fabrication of Zwitterionic Polymer Microneedles with Protein Aggregation Inhibition for Transdermal Drug Delivery, Biomacromolecules (2021). DOI: 10.1021/acs.biomac.1c01325

https://medicalxpress.com/news/2021-12-rethinking-drugs-breakthroug...

Part 2

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Comment by Dr. Krishna Kumari Challa on December 28, 2021 at 11:46am

Rethinking how drugs are administered: A breakthrough in microneedle patches

The painful feeling of receiving an injection through a hypodermic needle or with the unpleasant sensation of swallowing a large pill is a globally familiar sensation. But what if a revolutionary and gentler way of administering drugs was in the works? For over two decades, researchers have been investigating various types of microneedles as a minimally invasive method for transdermal drug delivery. Arrays of microneedles can be designed to be loaded with a drug or chemical, which they then release over time onto the blood stream after piercing slightly beyond the skin layers.

Microneedles offer several advantages compared to other types of drug delivery. First, they are painless and cause virtually no damage to the skin nor bleeding. Second, they can be self-administered. Third, unlike traditional needles, the disposal of microneedles is much easier as they don't leave behind hazardous waste. Unfortunately, there are still a few challenges that need to be addressed before microneedles become the next big thing in healthcare. One is their fabrication cost, which generally involves expensive molds, materials, and machinery. Another issue is the aggregation and degradation of proteins when microneedles are pre-loaded with a protein-based medicine, as these molecules are quite sensitive to external conditions such as temperature, acidity and salt concentration.

In a recent study published in Biomacromolecules, two research teams from Japan and Thailand collaborated to address the main limitations of existing microneedles.

One team developed and applied a functional polymer that effectively suppresses protein aggregation. The other team perfected a microneedle fabrication method suitable for the industrial scale based on photolithography. By combining these two efforts, the teams managed to produce microneedles patches with several attractive properties and potential scalability to clinical settings.

Part 1

Comment by Dr. Krishna Kumari Challa on December 28, 2021 at 11:42am

Heavy metals have a reputation for being dangerous, but some are essential nutrients that you can't live without.

Comment by Dr. Krishna Kumari Challa on December 28, 2021 at 7:37am

Snapshots from high in the sky allow new insight into ecosystems around the world

Comment by Dr. Krishna Kumari Challa on December 28, 2021 at 7:28am

Mountain spring water isn't as clean as you think it is

 Mountain spring water is often touted as the cleanest water you can drink. But a new study revealed this isn't the case.

Using data collected over 40 years, researchers detailed how water quality in high-elevation streams has been negatively affected by a combination of historical events and modern changes, namely sediment from rural roads and agricultural runoff.

Unpaved roads are just one of several factors contributing to sediment runoff.

When streams carry a lot of sediment, it makes it more difficult for animals to see food in the water, and it affects fish growth and disease resistance. Sediment also continues to flow downstream and into public water supplies, where it costs cities and towns more to filter.

The landscape you see now isn't what it was like in 1900. For generations, people farmed the valleys  and left the hillsides forested, for hunting and gathering. But the new settlers cut the forests and even tried to farm the hills, causing erosion and sediment to move into the streams. Today, stream beds continue to show evidence of sediment deposited more than a century ago, even as new sediment pushes through the waters.

Many years later, a new kind of development in the region created a different kind of land disturbance. For generations, residents considered the steep mountain slopes undevelopable. But the 1980s and '90s brought a desire for mountain getaway homes with views.

By building homes on mountain ridges, he said, it created more land disturbance through carving out unpaved roads and cutting into hillsides, sometimes creating landslides.

"Roadside ditches and unpaved roads produce a lot of sediment, and their sediment production increases as roads get steeper and as gravel roads get more use. in areas with both mountain and valley development, the researchers found sediment concentrations four to six times higher.

Farming also takes its toll. The studies researchers analyzed found many streams in the area to have high nutrient concentrations—particularly nitrate. When a stream flowing through a pasture loses its buffer of trees, it loses a natural protection against nutrient runoff.

Streams without shade also have higher water temperatures.

The paper was published earlier this month in the journal Bioscience.

C Rhett Jackson et al, Distinctive Connectivities of Near-Stream and Watershed-Wide Land Uses Differentially Degrade Rural Aquatic Ecosystems, BioScience (2021). DOI: 10.1093/biosci/biab098

https://researchnews.cc/news/10775/Mountain-spring-water-isn-t-as-c...

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Comment by Dr. Krishna Kumari Challa on December 28, 2021 at 7:21am

The telescope is on a 30-day long journey to cover the 15,00,000 kilometers distance between Earth and its intended orbit. It will reach the location by the end of January.

Source: https://www.indiatoday.in/science/story/where-is-james-webb-telesco...

Part 4

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Comment by Dr. Krishna Kumari Challa on December 28, 2021 at 7:20am

Animation: The James Webb Space Telescope's Orbit

Part 3

Comment by Dr. Krishna Kumari Challa on December 28, 2021 at 7:19am

This location lets the telescope stay in line with the Earth as it moves around the Sun allowing its large sunshield to protect the telescope from the light and heat of the Sun and Earth (and Moon). The position is named in honour of Italian-French mathematician Josephy-Louis Lagrange.

There are five special points where a small satellite can orbit in a constant portion with two big masses. At these five positions part of the Earth-Sun system, three (L1, L2 and L3) lie along the line connecting the two large masses. Meanwhile, L4 and L5 form the apex.

According to Nasa, the L1 point of the Earth-Sun system affords an uninterrupted view of the sun and is currently home to the Solar and Heliospheric Observatory Satellite SOHO. The L2, where the James Webb Space Telescope is going, is ideal for astronomy because a spacecraft is close enough to readily communicate with Earth, can keep Sun, Earth and Moon behind the spacecraft for solar power and (with appropriate shielding) provides a clear view of deep space.

It is to be noted that L1 and L2 points are unstable and satellites functioning from this location need to go through regular course corrections. Meanwhile, L3 remains behind the Sun and is unlikely to be used.

WHY WAS THIS PARTICULAR LOCATION SELECTED FOR THE TELESCOPE?

The location was chosen since James Webb will be observing the universe in infrared vision which can sometimes be fe... and since it is looking for the faintest signals, it needs to be safeguarded from any bright, hot sources, the biggest being our Sun.

The telescope itself will be operating at about -225 degrees Celsius and the temperature difference between the front and back of the spacecraft will be huge. To protect the telescope, the location needs to be such that light and heat from the Sun, Moon and Earth needs to come from just one direction. The second lagrange point is the optimum location from where Sun, Moon and Earth are in the one-line direction.

Part 2

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