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Archive for the ‘chemistry’ category: Page 95

Aug 5, 2023

WHO expert cancer group states that the sweetener aspartame is a possible carcinogen, but evidence is limited — 6 questions answered

Posted by in categories: biotech/medical, chemistry, health

Assessments of the health impacts of the non-sugar sweetener aspartame are released today by the International Agency for Research on Cancer (IARC) and the World Health Organization (WHO) and the Food and Agriculture Organization (FAO) Joint Expert Committee on Food Additives (JECFA). Citing “limited evidence” for carcinogenicity in humans, IARC classified aspartame as possibly carcinogenic to humans (IARC Group 2B) and JECFA reaffirmed the acceptable daily intake of 40 mg/kg body weight. Aspartame is an artificial (chemical) sweetener widely used in various food and beverage products since the 1980s, including diet drinks, chewing gum, gelatin, ice cream, dairy products such as yogurt, breakfast cereal, toothpaste and medications such as cough drops and chewable vitamins.

https://www.who.int/news/item/14-07-2023-aspartame-h…s-released


An expert panel found a potential association with liver cancer, but too little research exists to assume a causal connection. For now, the WHO left current consumption guidelines unchanged.

Continue reading “WHO expert cancer group states that the sweetener aspartame is a possible carcinogen, but evidence is limited — 6 questions answered” »

Aug 5, 2023

CDC detects coronavirus, HIV, hepatitis and herpes at unlicensed California lab

Posted by in categories: biological, biotech/medical, chemistry, law, life extension

Local and federal authorities spent months investigating a warehouse in Fresno County, California, that they suspect was home to an illegal, unlicensed laboratory full of lab mice, medical waste and hazardous materials.

The Fresno County Public Health Department has been “evaluating and assessing the activities of an unlicensed laboratory” in Reedley, the health department’s assistant director, Joe Prado, said in a statement Thursday. All of the biological agents were destroyed by July 7 following a legal abatement process by the agency.

“The evaluation required coordination and collaboration with multiple federal and state agencies to determine and classify biological and chemical contents onsite, in addition to assessing jurisdictional authority under this unique situation,” Prado said.

Aug 5, 2023

New, simple and accessible method creates potency-increasing structure in drugs

Posted by in categories: biotech/medical, chemistry

Chemical structures called cyclopropanes can increase the potency and fine-tune the properties of many drugs, but traditional methods to create this structure only work with certain molecules and require highly reactive—potentially explosive—ingredients.

Now, a team of researchers from Penn State has identified and demonstrated a safe, efficient and practical way to create cyclopropanes on a wide variety of molecules using a previously undescribed chemical process. With additional development, the new method—described in a paper publishing Aug. 4 in the journal Science —could transform how this important process occurs during and creation.

Cyclopropanes are a key feature in many drugs currently approved by the U.S. Food and Drug Administration, including those used to treat COVID-19, asthma, hepatitis C, and HIV/AIDs. These structures can increase a drug’s potency, alter its ability to dissolve in the body, minimize its interactions with unintended targets, and otherwise fine-tune performance. Cyclopropanes are a ring of three connected carbon atoms, with one carbon attached to the rest of the drug molecule and the other two each attached to two hydrogen atoms.

Aug 4, 2023

X-Ray Of A Single Atom Achieved In World First

Posted by in categories: biotech/medical, chemistry

Thinking of X-rays might trigger memories of broken bones or dental check-ups. But this extremely energetic light can show us more than just our bones: it is also used to study the molecular world, even biochemical reactions in real-time. One issue, though, is that researchers have never been able to study a single atom with X-rays. Until now.

Scientists have been able to characterize a single atom using X-rays. Not only were they able to distinguish the type of atoms they were seeing (there were two different ones), but they also managed to study the chemical behavior these atoms were showing.

“Atoms can be routinely imaged with scanning probe microscopes, but without X-rays, one cannot tell what they are made of. We can now detect exactly the type of a particular atom, one atom-at-a-time, and can simultaneously measure its chemical state,” senior author Professor Saw Wai Hla, from the University of Ohio and the Argonne National Laboratory, said in a statement.

Aug 3, 2023

DNA tilts and stretches underlie differences in mutation rates across genomes

Posted by in categories: biotech/medical, chemistry, evolution, genetics, health

Each cell in the body stores its genetic information in DNA in a stable and protected form that is readily accessible for the cell to carry on its activities. Nevertheless, mutations—changes in genetic information—occur throughout the human genome and can have a powerful influence on human health and evolution.

“Our team is interested in a classical question about mutation—why do in the genome vary so tremendously from one DNA location to another? We just do not have a clear understanding of why this occurs,” said Dr. Md. Abul Hassan Samee, assistant professor of integrative physiology at Baylor College of Medicine and corresponding author of the work.

Previous studies have shown that the DNA sequences flanking a mutated position—the sequence context—play a strong role in the mutation rate. “But this explanation still leaves unanswered questions,” Samee said. “For example, one type of mutation occurs frequently in a specific sequence context while a different type of mutation occurs infrequently in that same sequence context. So, we think that a different mechanism could explain how mutation rates vary in the genome. We know that each building block or base that makes up a DNA sequence has its own 3D chemical shape. We proposed, therefore, that there is a connection between DNA shape and rates, and this paper shows that our idea was correct.”

Aug 2, 2023

Aging process slows when older mice share circulatory system of young

Posted by in categories: biotech/medical, chemistry, life extension

A process of surgically joining the circulatory systems of a young and old mouse slows the aging process at the cellular level and lengthens the lifespan of the older animal by up to 10%.

Published in the journal Nature Aging, a study led by researchers at Duke University Medical Center in Durham, North Carolina, found that the longer the animals shared circulation, the longer the anti-aging benefits lasted once the two were no longer connected.

The findings suggest that the young benefit from a cocktail of components and chemicals in their blood that contributes to vitality, and these factors could potentially be isolated as therapies to speed healing, rejuvenate the body, and add years to an older individual’s life.

Aug 2, 2023

Genetically Engineering Cells to Respond to Electricity

Posted by in categories: biotech/medical, chemistry, engineering, genetics

A paper published today in Nature Metabolism has described a method of genetically engineering cells to respond to electrical stimuli, allowing for on-demand gene expression.

Despite its futuristic outlook, this line of research is built upon previous work. The idea of an implantable gene switch to command cells in order to deliver valuable compounds into the human body is not new. The authors of this paper cite longstanding work showing that gene switches can be developed to respond to antibiotics [1] or other drugs, and the antibiotic doxycycline is used regularly for this purpose in mouse models. More recently, researchers have worked on cells that control their output based on green light [2], radio waves [3], or heat [4].

However, these mechanisms have their problems. A gene trigger that operates in response to a chemical compound requires that compound to have stable, controllable biological availability [5]. If it relies on any wavelength of electromagnetic radiation, that process may be triggered by mistake or require intense energy to function [3].

Aug 1, 2023

Kimchi chemistry and cat-nose chromatography

Posted by in category: chemistry

Serving the chemical, life science, and laboratory worlds.

Aug 1, 2023

New nanotech identifies chemical composition and structure of impurities in air, liquid and living tissue

Posted by in categories: biotech/medical, chemistry, nanotechnology

Using conventional testing techniques, it can be challenging—sometimes impossible—to detect harmful contaminants such as nano-plastics, air pollutants and microbes in living organisms and natural materials. These contaminants are sometimes found in such tiny quantities that tests are unable to reliably pick them up.

This may soon change, however. Emerging nanotechnology (based on a “twisted” state of light) promises to make it easier to identify the of impurities and their geometrical shape in samples of air, liquid and live tissue.

An international team of scientists led by physicists at the University of Bath is contributing toward this technology, which may pave the way to new environmental monitoring methods and advanced medicines. Their work is published in the journal Advanced Materials.

Aug 1, 2023

Golgi apparatus may play a role in neuronal circuit reorganization during postnatal brain development

Posted by in categories: chemistry, neuroscience

Neurons are the cells that constitute neural circuits and use chemicals and electricity to receive and send messages that allow the body to do everything, including thinking, sensing, moving, and more. Neurons have a long fiber called an axon that sends information to the subsequent neurons. Information from axons is received by branch-like structures that fan out from the cell body, called dendrites.

Dendritic refinement is an important part of early postnatal brain development during which dendrites are tailored to make specific connections with appropriate axons. In a recently published paper, researchers present evidence showing how a mechanism within the neurons of a rodent involving the Golgi apparatus initiates dendritic refinement with the help of the neuronal activity received by a receptor of a neurotransmitter called N-methyl-D-aspartate-type glutamate receptor (NMDAR).

The paper was published in Cell Reports on July 28.

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