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Comment by Dr. Krishna Kumari Challa on April 21, 2025 at 10:06am

Cold welding is a solid-state welding process where metals bond without the need for heat, and it's a significant concern in space due to the vacuum environment. This phenomenon can cause malfunctions and even failures in spacecraft mechanisms, such as deployment issues and stuck mechanisms.
What it is:
Cold welding occurs when clean metal surfaces of the same material are brought into close contact under high pressure, even without heat or external agents.
In space, the vacuum environment removes the air that would normally form an oxide layer on the metal surface, allowing for a stronger bond to form.
This process can be problematic because it can lead to the formation of undesired bonds between moving parts, causing them to become stuck or malfunction.
How it affects space missions:
Deployment Issues:
Cold welding can cause mechanisms designed to deploy antennas, solar panels, or other structures to fail to deploy properly.
Stuck Mechanisms:
It can also lead to mechanisms becoming stuck in a closed or folded position, preventing them from functioning as intended.
Galileo High-Gain Antenna:
A notable example is the 1991 Galileo spacecraft, where the high-gain antenna failed to deploy fully due to cold welding, which caused the umbrella-shaped antenna ribs to bond in their folded configuration.
Wire Harnesses:
Cold welding can also affect wire harnesses, causing individual wires to bond together and increasing harness stiffness, potentially leading to wire breakage or electrical overload.
Mitigation Strategies:
Material Selection:
Using dissimilar metals or metals with low contact adhesion can help prevent cold welding.
Coatings:
Applying coatings that reduce the adhesion of surfaces can also be effective.
Lubrication:
Using appropriate lubricants can reduce friction and prevent the formation of cold welds.
Reduced Contact Area:
Reducing the contact area between moving parts can minimize the potential for cold welding.
Cleanliness:
Maintaining cleanliness and preventing contamination of surfaces can also help prevent cold welding.

Comment by Dr. Krishna Kumari Challa on April 21, 2025 at 10:04am

Cold welding, also known as cold pressure welding or contact welding, is a solid-state joining process that creates strong bonds between metals without heat. It relies on high pressure to deform the surfaces of the metals, bringing them into intimate contact and forming a strong metallurgical bond.
Here's a more detailed explanation:
How it works:
No Heat:
Unlike traditional welding, cold welding doesn't involve melting or heating the metals.
Pressure:
The process relies on applying high pressure to the joined surfaces, causing plastic deformation and forming a bond.
Solid State:
The metals remain in a solid state throughout the process.
Clean Surfaces:
The surfaces of the metals must be very clean and free of oxides or other contaminants for a strong bond to form.
Advantages:
No Heat Affected Zone (HAZ):
Because no heat is involved, there's no heat affected zone, which can alter the properties of the metal.
Strong Bonds:
Cold welding can create strong bonds that are often as strong as the parent metal.
Dissimilar Metals:
It can be used to join dissimilar metals.
Suitable for Sensitive Materials:
It's ideal for joining metals that are heat-sensitive, such as aluminum and copper, where traditional welding could compromise their properties.
Disadvantages:
Surface Preparation: Requires meticulous surface preparation to remove oxides and contaminants.
Limited to Ductile Metals: Best suited for ductile metals like aluminum, copper, and brass alloys.
High Pressure: Requires high pressure to create the bond, which can be expensive and challenging.
Not for Irregular Surfaces: Less effective on irregular surfaces.
Applications:
Joining Aluminum and Copper:
Widely used for joining these metals, especially in applications where heat is undesirable.
Aerospace and Electronics:
Important in industries where avoiding heat distortion is crucial, such as in aerospace and electronics.
Wire Joining:
Used for joining wires together.
Space Applications:
Can be used in space for joining parts in environments with no heat sources.

Comment by Dr. Krishna Kumari Challa on April 19, 2025 at 10:18am

Having this in mind, the researchers collected 205 samples of over 80 Rosa species, covering 84% of what is documented in the "Flora of China."

The samples were then analyzed using genomic sequencing, population genetics, and other methods to trace back their ancestral traits. They studied 707 single-copy genes uncovered as a set of conserved genetic markers like single-nucleotide polymorphisms—the most common type of genetic variation found in DNA—which helped them chart the evolutionary and geographical history and connections between the rose species.

Ancestral trait reconstruction showed that the shared ancestor of the studied samples was a yellow flower with a single row of petals and leaves divided into seven leaflets. As roses evolved and were domesticated, they developed new colors, distinct petal markings, and the ability to bloom in clusters.
The study also brought new insight to the widely accepted notion that the Rosa genus originated in Central Asia. The genetic evidence pointed to two major centers of rose diversity in China—one in the dry northwest, where yellow roses with small leaves grow, and another in the warm and humid southwest, where the white, fragrant variety thrives.

 Bixuan Cheng et al, Phenotypic and genomic signatures across wild Rosa species open new horizons for modern rose breeding, Nature Plants (2025). DOI: 10.1038/s41477-025-01955-5

Valéry Malécot, An evolutionary bouquet for roses, Nature Plants (2025). DOI: 10.1038/s41477-025-01971-5

Part 2

Comment by Dr. Krishna Kumari Challa on April 19, 2025 at 10:13am

Red, pink or white, all roses were once yellow says genomic analysis

Red roses, the symbol of love, were likely yellow in the past, indicates a large genomic analysis by researchers.

Roses of all colors, including white, red, pink, and peach, belong to the genus Rosa, which is a member of the Rosaceae family.

Reconstructing the ancestral traits through genomic analysis revealed that all the roads trace back to a common ancestor—a single-petal flower with yellow color and seven leaflets.

The findings are published in Nature Plants.

Accounting for almost 30% of the cut flower market sales, roses are the most widely cultivated ornamental plants and have been successfully domesticated to reflect the aesthetic preferences of each era.

It all began with the rose breeding renaissance in the 1700s, marked by the crossing of ancient wild Chinese roses and old European cultivars—plants selectively bred through human intervention to develop a desirable characteristic.

Currently, we have over 150 to 200 species of roses and more than 35,000 cultivars, displaying a wide range of blooming frequencies, fragrances, and colors. However, global climate change has prompted rose breeders to shift their focus from purely cosmetic traits to breeding rose varieties that are more resistant to stress factors like drought, disease and easier to care for.

Borrowing genetic resources from wild rose varieties, which offer valuable traits such as fragrance and disease resistance, presents a promising strategy for breeding resilient, low-maintenance rose cultivars.

A clear understanding of the origin and evolution of the Rosa genus, both wild and cultivated varieties, can not only advance the breeding efforts but also aid in the conservation of near-threatened rose varieties.

Part 1

Comment by Dr. Krishna Kumari Challa on April 18, 2025 at 10:15am

A PFO is usually harmless yet is known to increase the odds of stroke. The study aimed to determine which risk factors contribute the most to unexplained strokes.

The analysis found:

Traditional risk factors were more strongly associated with stroke in men and women without a PFO.
In contrast, nontraditional risk factors, such as blood clots in the veins, migraine with aura, chronic kidney disease, chronic liver disease or cancer, were more strongly associated with stroke among study participants with a PFO.
In those without a PFO, each additional traditional risk factor increased stroke risk by 41%, while each nontraditional risk factor increased stroke risk by 70%.
Risk factors related to women also increased stroke risk by 70% independent of traditional and nontraditional risk factors.
Among participants with a PFO, each traditional risk factor increased the risk of stroke by 18%. However, after considering individual demographic factors, such as age, sex and level of education, nontraditional risk factors more than doubled the odds of having an ischemic stroke.
Researchers also analyzed the study population's attributable risk (determining how a disease would be impacted if a certain risk factor were eliminated). To calculate population-attributable risk, researchers analyzed each risk factor and their contribution to the increased risk separately and found:

For strokes that occur without a PFO, traditional risk factors accounted for about 65% of the cases, nontraditional risk factors contributed 27% and risk factors specific to women made up nearly 19% of the cases.
In contrast, for strokes associated with a PFO, traditional risk factors contributed about 34%, nontraditional risk factors accounted for 49% and female-specific risk factors represented about 22%.
Notably, migraine with aura was the leading nontraditional risk factor associated with strokes of unknown origin, with a population-attributable risk of about 46% for strokes among people with a PFO and about 23% for those without a PFO, indicating a higher risk for people with PFO.
The role of non-traditional risk factors, especially migraine headaches, which seems to be one of the leading risk factors in the development of strokes in younger adults, is a new revelation.

Burden of Modifiable Risk Factors in YoungOnset Cryptogenic Ischemic Stroke by High-Risk Patent Foramen Ovale, Stroke (2025). DOI: 10.1161/STROKEAHA.124.049855

Part 2

Comment by Dr. Krishna Kumari Challa on April 18, 2025 at 10:13am

Nontraditional risk factors shed light on unexplained strokes in adults younger than 50

Adults younger than 50 years of age had more than double the risk of having a stroke from migraine or other nontraditional stroke risk factors rather than traditional risks such as high blood pressure, according to research published in Stroke.

Previous research indicates the rate of ischemic (clot-caused) stroke among adults 18–49 years old is increasing and propelled by a corresponding rise in cryptogenic strokes (strokes of unknown cause) in adults without traditional risk factors, including high blood pressure, smoking, obesity, high cholesterol and type 2 diabetes.

Up to half of all ischemic strokes in younger adults are of unknown causes, and they are more common in women. For effective prevention, careful and routine assessment of both traditional and nontraditional risk factors in younger people is critical. 

Researchers analyzed data for more than 1,000 adults aged 18–49 in Europe, with a median age of 41 years. Half of the participants had experienced a cryptogenic ischemic stroke, while half had no history of stroke.

The study examined the associations of 12 traditional risk factors, 10 nontraditional risk factors and five risk factors specific to women (such as gestational diabetes or pregnancy complications). Researchers also closely reviewed participants with a heart defect called patent foramen ovale (PFO), a hole between the heart's upper chambers.

Part 1

Comment by Dr. Krishna Kumari Challa on April 18, 2025 at 9:49am

How cleft lip and cleft palate can arise

Cleft lip and cleft palate are among the most common birth defects.

These defects, which appear when the tissues that form the lip or the roof of the mouth do not join completely, are thought to be caused by a mix of genetic and environmental factors.

In a new study,  biologists have discovered how a genetic variant often found in people with these facial malformations leads to the development of cleft lip and cleft palate.

Their findings suggest that the variant diminishes cells' supply of transfer RNA, a molecule that is critical for assembling proteins. When this happens, embryonic face cells are unable to fuse to form the lip and roof of the mouth.

A non-syndromic orofacial cleft risk locus links tRNA splicing defects to neural crest cell pathologies, The American Journal of Human Genetics (2025). DOI: 10.1016/j.ajhg.2025.03.017. www.cell.com/ajhg/fulltext/S0002-9297(25)00138-7

Comment by Dr. Krishna Kumari Challa on April 18, 2025 at 9:42am

Scientists hack cell entry to supercharge cancer drugs

A new discovery could pave the way for more effective cancer treatment by helping certain drugs work better inside the body. Scientists have found a way to improve the uptake of a promising class of cancer-fighting drugs called PROTACs, which have struggled to enter cells due to their large size.

The new method works by taking advantage of a protein called CD36 that helps pull substances into cells. By designing drugs to use this CD36 pathway, researchers delivered 7.7 to 22.3 times more of the drug inside cancer cells, making the treatment up to 23 times more potent than before, according to the study published April 17 in Cell.

Data from mouse studies shows this enhanced uptake led to stronger tumor suppression without making the drugs harder to dissolve or less stable.

The strategy called chemical endocytic medicinal chemistry (CEMC) takes advantage of a natural process where cells "swallow" molecules called endocytosis. It could change the future of drug design—especially for drugs that were once considered too big to work.

CD36-mediated endocytosis of proteolysis-targeting chimeras, Cell (2025). DOI: 10.1016/j.cell.2025.03.036. www.cell.com/cell/fulltext/S0092-8674(25)00386-1

Comment by Dr. Krishna Kumari Challa on April 18, 2025 at 8:58am

With a comprehensive dataset and in-depth profiling of Gowanus microbial communities, researchers were able to identify previously undocumented microbial lineages and assess their potential for environmental remediation.

Metagenomic analysis of sediment samples from the Gowanus Canal revealed a diverse microbial community comprising 455 distinct microbial species, including bacteria, archaea, and viruses.

Across both surface and core samples, researchers identified 64 metabolic pathways involved in the degradation of organic contaminants, alongside 1,171 genes associated with the detoxification of heavy metals such as iron, copper, and nickel. Researchers identified 2,319 biosynthetic gene clusters, many of which may be linked to the production of novel secondary metabolites with potential therapeutic or industrial value.
A comprehensive screening of antimicrobial resistance genes demonstrated the presence of 28 resistance genes across eight different antibiotic classes, including agents commonly used in clinical settings such as rifampin and aminoglycosides.

Coexistence of pollutant-degrading genes and antimicrobial resistance likely arises from ecological adaptations driven by prolonged exposure to urban and industrial waste. Microorganisms within the canal deploy multiple degradation pathways to metabolize pollutants like toluene and phenolic compounds, while simultaneously exhibiting traits that confer resilience to heavy metal stress.
Findings suggest that extreme urban ecosystems like the Gowanus Canal may act as reservoirs of both beneficial and hazardous genetic elements. Some of the antimicrobial resistance genes appear to originate from human gut-associated microbes, likely introduced through untreated sewage overflow, raising urgent new concerns around public health risks.

While not an experiment any scientist would have chosen to run, if future research findings lead to novel industrial or clinical insights, it could transform the Gowanus Canal from a symbol of urban neglect into that of a living laboratory. One where the pressures of prolonged contamination have forged a microbial community that has created the keys to future ecological restoration and molecular innovation.

Sergios-Orestis Kolokotronis et al, Metagenomic interrogation of urban Superfund site reveals antimicrobial resistance reservoir and bioremediation potential, Journal of Applied Microbiology (2025). DOI: 10.1093/jambio/lxaf076

Part 2

Comment by Dr. Krishna Kumari Challa on April 18, 2025 at 8:55am

Extreme microbial adaptations arise in one of  most polluted waterways

The industrially ravaged Gowanus Canal, long regarded as a symbol of urban environmental neglect, is being reimagined through the lens of scientific inquiry as a complex reservoir of microbial life shaped by intense selective pressures.

Research  has discovered microbes in Brooklyn's Gowanus Canal that carry genes for breaking down industrial pollutants and neutralizing heavy metals. Genetic screening also uncovered resistance to multiple antibiotic classes and thousands of biosynthetic gene clusters with implications for developing new antibiotics, industrial enzymes, and bioactive compounds.

Built in the mid 1800s, the 2.9 km long industrial canal has experienced over 150 years of unregulated environmental abuse. As a hub of heavy industry, various mills, petroleum and chemical plants have lined the canal banks.

Unknown volumes of arsenic, heavy metals, polychlorinated biphenyls, coal tar, petroleum products, volatile organic compounds, chlorinated solvents and untreated sewage overflow have discharged into the small waterway.

Designated a Superfund site in 2010, the Gowanus Canal is one of the most contaminated waterways in the United States. When the EPA began evaluating the site for restoration, they discovered approximately two hundred previously unknown and unpermitted pipes that discharge directly into the canal.

So toxic are the sediments and extreme the environment that mere skin contact with the water poses a health hazard for humans. To microbiologists, such extreme environments are highly intriguing opportunities to see how life finds a way to adapt and even thrive. Microbial life has previously been discovered in similarly extreme contexts.

Discoveries in NASA clean rooms revealed microbes that lived off of paint and cleaning solutions. An enzyme that revolutionized early genomic research came from a bacterium found in the hot springs of Yellowstone National Park. Microorganisms discovered in contaminated environments have previously been used to degrade petroleum hydrocarbons and other pollutants.

While the Gowanus Canal is unquestionably an environmental disaster, it can also serve as a long-running experiment in microbial evolution.

In the study, "Metagenomic interrogation of urban Superfund site reveals antimicrobial resistance reservoir and bioremediation potential," published in the Journal of Applied Microbiology, researchers performed a metagenomic analysis of microbial communities in the Gowanus Canal.

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