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Archive for the ‘chemistry’ category: Page 117

Jul 13, 2023

Jean-Pierre Sauvage, Nobel Laureate in Chemistry: ‘Work is being done on machines that will travel through the blood to kill cancer’

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

Last year, the chemist – who is an emeritus professor at the University of Strasbourg – published a book titled The Elegance of Molecules. In the pages, he lets his imagination run wild. “Over time, most of the chemical reactions that govern nature could be controlled or imitated by a nanorobot: counter-offensives by the immune system, the production of antibodies, hormones on demand, the repairing of damaged cells and organs [or] the correction of anomalies in the genetic text,” Sauvage writes. “None of this will belong in the realm of science fiction in the long-term.”

Sitting in the hotel’s restaurant, however, the researcher’s realism contrasts with his futuristic fantasy. “Today, we can’t do much. Molecular machines are a somewhat new concept: we can make molecules that move as we choose [and] we can make a fairly complex molecule perform a rotary motion. Or we can make it behave like a muscle, stretching and contracting. The applications will arrive in the future, but we’re not there yet,” he stresses.

The French researcher has been developing these molecular muscles since 2002 alongside a Spanish chemist – María Consuelo Jiménez – from the Polytechnic University of Valencia. “The first thing was to show that we can make a molecule that contracts and stretches. Now, you can think of making materials – especially fibers – that can contract and stretch. Perhaps artificial muscles could be made to replace damaged muscles in people, but that will be in the future. At the moment, there are no real applications,” Sauvage clarifies.

Jul 13, 2023

Integrated internal ion-gated organic electrochemical transistors for stand-alone conformable bioelectronics

Posted by in categories: chemistry, computing

Organic electronic devices enhance biocompatibility, but have to rely on silicon-based technologies to improve limited speed and integration. This problem is overcome by creating a stand-alone, wireless, conformable, fully organic bioelectronic device with high electronic performance, scalability, stability and conformability in physiologic media.

Jul 13, 2023

Harnessing Hydrogen in a Safe, Easy, and Affordable Way for a Decarbonized Future

Posted by in categories: chemistry, economics, particle physics

Japanese scientists have discovered a compound, ethylammonium lead iodide, which can store and release ammonia safely and efficiently. This finding holds potential for ammonia’s role as a carbon-free hydrogen carrier, contributing to the transition towards a decarbonized society.

Researchers at the RIKEN Center for Emergent Matter Science (CEMS) in Japan have discovered a compound that uses a chemical reaction to store ammonia, potentially offering a safer and easier way to store this important chemical. This discovery, published in the Journal of the American Chemical Society on July 10, makes it possible not only to safely and conveniently store ammonia, but also the important hydrogen is carries. This finding should help lead the way to a decarbonized society with a practical hydrogen economy.

For society to make the switch from carbon-based to hydrogen-based energy, we need a safe way to store and transport hydrogen, which by itself is highly combustible. One way to do this is to store it as part of another molecule and extract it as needed. Ammonia, chemically written as NH3, makes a good hydrogen carrier because three hydrogen atoms are packed into each molecule, with almost 20% of ammonia being hydrogen by weight.

Jul 12, 2023

The Role of [18F]F-Choline PET/CT in the Initial Management and Outcome Prediction of Prostate Cancer: A Real-World Experience from a Multidisciplinary Approach

Posted by in categories: biotech/medical, chemistry

Initial staging of prostate cancer (PCa) is usually performed with conventional imaging (CI), involving computed tomography (CT) and bone scanning (BS). The aim of this study was to analyze the role of [18F]F-choline positron emission tomography (PET)/CT in the initial management and outcome prediction of PCa patients by analyzing data from a multidisciplinary approach. We retrospectively analyzed 82 patients who were discussed by the uro-oncology board of the University Hospital of Ferrara for primary staging newly diagnosed PCa (median age 72 (56–86) years; median baseline prostate specific antigen (PSA) equal to 8.73 ng/mL). Patients were divided into three groups based on the imaging performed: group A = only CI; group B = CI + [18F]F-choline PET/CT; group C = only [18F]F-choline PET/CT. All data on imaging findings, therapy decisions and patient outcomes were retrieved from hospital information systems. Moreover, we performed a sub-analysis of semiquantitative parameters extracted from [18F]F-choline PET/CT to search any correlation with patient outcomes. The number of patients included in each group was 35, 35 and 12, respectively. Patients with higher values of initial PSA were subjected to CI + PET/CT (p = 0.005). Moreover, the use of [18F]F-choline PET/CT was more frequent in patients with higher Gleason score (GS) or ISUP grade (p = 0.013). The type of treatment performed (surgery n = 33; radiation therapy n = 22; surveillance n = 6; multimodality therapy n = 6; systemic therapy n = 13; not available n = 2) did not show any relationship with the modality adopted to stage the disease. [18F]F-choline PET/CT induced a change of planned therapy in 5/35 patients in group B (14.3%). Moreover, patients investigated with [18F]F-choline PET/CT alone demonstrated longer biochemical recurrence (BCR)-free survival (30.8 months) in comparison to patients of groups A and B (15.5 and 23.5 months, respectively, p = 0.006), probably due to a more accurate selection of primary treatment. Finally, total lesion choline kinase activity (TLCKA) of the primary lesion, calculated by multiplying metabolic tumor volume and mean standardized uptake value (SUVmean), was able to more effectively discriminate patients who had recurrence after therapy compared to those without (p = 0.03). In our real-world experience [18F]F-choline PET/CT as a tool for the initial management of PCa had a relevant impact in terms of therapy selection and was associated with longer BCR-free survival. Moreover, TLCKA of the primary lesion looks a promising parameter for predicting recurrence after curative therapy.

Jul 12, 2023

Failed NGS or qPCR? Spectrophotometry can tell why

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

Genomic analyses, such as next-generation sequencing (NGS) and quantitative polymerase chain reaction (qPCR), require pure nucleic acids and accurate analyte concentrations to perform successful reactions. The purification process to access this genetic material uses methods that rely on detergents, mechanical disruption, and heat to disrupt the cellular structures of nuclei, ribosomes, bacteria, and viruses. Nucleic acid is then purified by performing a solvent extraction, alcohol precipitation, and salting-out.

Contaminants can copurify with nucleic acids

Isolation of nucleic acids (including various forms of DNA and RNA) may be needed from cell harvest, PCR, restriction enzyme digest, agarose gel, and other sources. Several avenues in nucleic acid extraction protocols inadvertently allow the co-precipitation of contaminants owing to the type of starting material or the chosen extraction method (Table 1). In some cases, changing the method or adding another purification step can mitigate or eliminate the copurification issue. However, when contamination remains an issue, it is important to learn as much as possible about the impurities that can denature enzymes, block templates, or otherwise lead to failed chemical reactions necessary for downstream applications.

Jul 12, 2023

New insights into glucose metabolism: targeting ATP synthase with chromium (III) nutritional supplement for improved blood sugar control

Posted by in categories: biotech/medical, chemistry

Recently, a research team led by Professor Hongzhe SUN from the Department of Chemistry, Faculty of Science, The University of Hong Kong, has published a paper in Nature Communications.

The researchers found that, chromium(III) (Cr(III)), a nutritional supplement, can enhance cells’ ability to metabolise glucose by regulating ATP synthase activity. This process improves mitochondrial deformation caused by high glucose levels and significantly boosts glucose metabolism in type 2 diabetic mice. To uncover the protein targets of Cr(III) and elucidate the molecular mechanism, the team has developed a fluorescent probe for detecting transient metal-protein interactions, achieving a high spatiotemporal resolution tracking of the Cr(III) proteome in HepG2 cells. This led to the identification of Cr(III)-binding proteins within cells. The team then revealed that Cr(III) replaces magnesium ions (Mg2+) in ATP synthase, reduces ATP synthase activity, and activates the downstream AMPK pathway, resulting in improved glucose metabolism. This study provides a novel concept for hypoglycaemic research.

“Although Cr(III) compounds have long been used as a nutritional supplement for diabetes treatment, weight loss and muscle development, its protein target and mechanism of action remain concealed for over half a century. We used a novel fluorescent probe, along with other chemical biology approaches, to uncover the long-standing scientific problem of the biological chemistry of Cr(III) and discovered that Cr(III) targets ATP synthase to regulate glucose,” commented Professor Sun.

Jul 12, 2023

Optoelectronics Nanotechnology Innovation: MIT Grows Precise Arrays of nanoLEDs

Posted by in categories: biological, chemistry, nanotechnology, physics

A new technique produces perovskite nanocrystals right where they’re needed, so the exceedingly delicate materials can be integrated into nanoscale.

The nanoscale refers to a length scale that is extremely small, typically on the order of nanometers (nm), which is one billionth of a meter. At this scale, materials and systems exhibit unique properties and behaviors that are different from those observed at larger length scales. The prefix “nano-” is derived from the Greek word “nanos,” which means “dwarf” or “very small.” Nanoscale phenomena are relevant to many fields, including materials science, chemistry, biology, and physics.

Jul 12, 2023

Scientists track nanoscale processes of CRISPR-Cas complexes

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

Scientists at Leipzig University, in collaboration with colleagues at Vilnius University in Lithuania, have developed a new method to measure the smallest twists and torques of molecules within milliseconds. The method makes it possible to track the gene recognition of CRISPR-Cas protein complexes, also known as “genetic scissors”, in real time and with the highest resolution. With the data obtained, the recognition process can be accurately characterised and modelled to improve the precision of the genetic scissors. The results obtained by the team led by Professor Ralf Seidel and Dominik Kauert from the Faculty of Physics and Earth Sciences have now been published in the prestigious journal Nature Structural and Molecular Biology.

When bacteria are attacked by a virus, they can defend themselves with a mechanism that fends off the genetic material introduced by the intruder. The key is CRISPR-Cas protein complexes. It is only in the last decade that their function for adaptive immunity in microorganisms has been discovered and elucidated. With the help of an embedded RNA, the CRISPR complexes recognize a short sequence in the attacker’s DNA. The mechanism of sequence recognition by RNA has since been used to selectively switch off and modify genes in any organism. This discovery revolutionized genetic engineering and was already honored in 2020 with the Nobel Prize in Chemistry awarded to Emmanuelle Charpentier and Jennifer A. Doudna.

Occasionally, however, CRISPR complexes also react to gene segments that differ slightly from the sequence specified by the RNA. This leads to undesirable side effects in medical applications. “The causes of this are not yet well understood, as the process could not be observed directly until now,” says Dominik Kauert, who worked on the project as a PhD student.

Jul 12, 2023

Photophysical oxidation plays newly discovered role in atmospheric chemistry

Posted by in category: chemistry

A newly discovered pathway for formaldehyde oxidation could be an important general mechanism in tropospheric chemistry. In the new route, absorption of sunlight allows organic molecules to react with atmospheric oxygen in a reaction that had not previously been observed. According to the researchers behind the findings, many compounds in the atmosphere are likely to undergo this process, particularly at low altitudes.

‘We discovered a new way molecules in the atmosphere can react,’ says Scott Kable at the University of New South Wales in Australia. He explains that in this process – called photophysical oxidation (PPO) – a molecule absorbs sunlight and before it breaks into fragments, it reacts with atmospheric oxygen to produce free radicals. In the common photochemical oxidation (PCO) reaction, which has been known for several decades, the molecules are first split by sunlight and then the fragments react with oxygen. ‘Importantly, the free radical fragments formed in the first step of PCO can be measured separately in the atmosphere or a lab,’ points out Kable.

The team demonstrated the PPO mechanism using formaldehyde as a model system. Meredith Jordan from the University of Sydney mentions that many organic compounds released to the environment turn into formaldehyde on their way to being oxidised to carbon dioxide. ‘But most importantly for our research, the spectroscopy and photochemistry of this compound are very well understood,’ she says. ‘Without this detailed pre-existing knowledge, we wouldn’t have been able to find the evidence of PPO.’

Jul 12, 2023

Japanese researchers find a simple and affordable way to store hydrogen

Posted by in category: chemistry

UniqueMotionGraphics/iStock.

Ammonia, chemically written as NH3, is widely used across industries ranging from textiles to pharmaceuticals and is an important component in the manufacture of fertilizers. For its current use, ammonia is stored in pressure-resistant containers after liquefying it at temperatures of-27 Fahrenheit (−33 degrees Celsius).