Small size of bioprosthetic aortic valves less dangerous than previously believed

Michael Dismorr
Photo Credit: Oliver von Olnhausen

Researchers at the Thoracic Surgery research group, the Department of Molecular Medicine and Surgery, have performed a nation-wide study of patients who underwent bioprosthetic aortic valve replacement in Sweden between 2003 and 2018. The study is published in the Journal of the American College of Cardiology, JACC, and shows that it is less dangerous than previously believed to receive a small bioprosthetic aortic valve in relation to the patient's size.

During surgical aortic valve replacement, the patient receives a valve prosthesis that matches the size of the aortic root. Sometimes, that size is too small in relation to the patient’s body size. This puts strain on the heart to pump enough blood that the body needs through a narrow valve. The level of “narrowness” is measured as Prosthesis Patient Mismatch, PPM.

“Prior studies have shown that both moderate and severe PPM decreases survival and increases the risk for heart failure. In our study, we can confirm that severe PPM decreases survival and increases the risk for heart failure, while moderate PPM has a very limited effect on survival and no effect on the risk for heart failure”, says Michael Dismorr, postdoctoral researcher at the Department of Molecular Medicine and Surgery and first author of the study.

How Do Microbes Live Off Light?

Prof. Oded Béjà (left) and PhD student Ariel Chazan
Photo Credit: Technion-Israel Institute of Technology

Plants convert light into a form of energy that they can use – a molecule called adenosine triphosphate (ATP) – through photosynthesis. This is a complex process that also produces sugar, which the plant can use for energy later, and oxygen. Some bacteria that live in the light-exposed layers of water sources can also convert light to ATP, but the process they use is simpler and less efficient than photosynthesis. Nonetheless, Technion – Israel Institute of Technology researchers now find this process isn’t as straightforward and limited as was previously thought.

Rhodopsin are the light-driven proton pumps that bacteria employ to produce ATP. Whereas photosynthesis is a process that involves multiple stages and proteins, rhodopsin performs everything itself. It is not more efficient, but rather it is like the difference between a medieval workshop and a modern factory. The rhodopsin's are activated by a molecule called “retinal,” which absorbs light. Specifically, in these proteins retinal absorbs green light. A different molecule, a carotenoid “antenna,” can enable it to also absorb blue light as well, increasing the amount of energy the rhodopsin can produce.

New Fluorescent Sensors Make it Possible to Detect the Concentration of Mercury in Water

New fluorophores selectively and with high sensitivity recognize mercury ions.
Photo Credit: Anna Marinovich

Scientists from the UrFU, together with Italian and Bulgarian colleagues, synthesized new heterocyclic fluorophores - four types of carboxamides of 2-aryl-1,2,3-triazoles. Their photophysical properties have been investigated under different conditions - solvents and their binary mixtures with water. Sensors based on the fluorophores obtained were sensitive to mercury, so they can be used to detect mercury concentrations in water. Further research will focus on determining the possibility of using these fluorophores to target medicines to affected organs. The authors have published an article on their research and results in the journal Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy.

"A disadvantage of organic fluorophores is their poor solubility in water and aqueous environments. At the same time, when water is added to organic solvents, most dyes and fluorophores have fluorescence quenching. However, in 2001, Professor Ben Zhong Tan of the Chinese University of Hong Kong found that some fluorophores observed not quenching, but rather an increase the fluorescence intensity. This is due to the formation of much larger particles, or nano-aggregates, from the molecules of fluorophores. Tan's discovery was of great significance. Much scientific effort has been devoted to studying the mechanism of his discovery, as well as to the design and synthesis of new fluorophores with the effect of increasing the emission. The fluorophores we obtained have also demonstrated in a mixture of organic solvent and water the effect described by Tang, and with a particular intensity. This opens the way to the practical application of the obtained fluorophores in various fields, especially in the aquatic environment," says Natalya Belskaya, Full Professor of the UrFU Department of Technology of Organic Synthesis and leader of the research team.

Study finds silicon, gold and copper among new weapons against COVID-19

New Curtin research has found the spike proteins of SARS-CoV-2, a strain of coronaviruses that caused the COVID-19 pandemic, become trapped when they come into contact with silicon, gold and copper, and that electric fields can be used to destroy the spike proteins, likely killing the virus.

Lead researcher Dr Nadim Darwish, from the School of Molecular and Life Sciences at Curtin University said the study found the spike proteins of coronaviruses attached and became stuck to certain types of surfaces.

“Coronaviruses have spike proteins on their periphery that allow them to penetrate host cells and cause infection and we have found these proteins becomes stuck to the surface of silicon, gold and copper through a reaction that forms a strong chemical bond,” Dr Darwish said.

“We believe these materials can be used to capture coronaviruses by being used in air filters, as a coating for benches, tables and walls or in the fabric of wipe cloths and face masks.

An internal thermometer tells the seeds when to germinate

A team from the UNIGE has discovered how the seed decides to remain in "hibernation" or to trigger germination depending on the outside temperature. Here, a section of a seed of Arabidopsis thaliana.
Image Credit: © UNIGE / Sylvain Loubéry

A UNIGE team has discovered the mechanisms by which the seed decides to remain in «hibernation» or to trigger its germination depending on the outside temperature.

Germination is a crucial stage in the life of a plant as it will leave the stage of seed resistant to various environmental constraints (climatic conditions, absence of nutritive elements, etc.) to become a seedling much more vulnerable. The survival of the young plant depends on the timing of this transition. It is therefore essential that this stage be finely controlled. A Swiss team, led by scientists from the University of Geneva (UNIGE), has discovered the internal thermometer of seeds that can delay or even block germination if temperatures are too high for the future seedling. This work could help optimize plant growth in the context of global warming. These results can be read in the journal Nature Communications.

COVID Fears and Long-Term Planning Play Key Roles in Vaccine Hesitancy

Young boy receiving a vaccine
Photo Credit: Heather Hazzan. Shared under a Creative Commons license (CC BY 2.0)

A recent study finds that concerns about the health effects of COVID-19 are a key variable in determining whether people are hesitant to get vaccinated against the virus. The study also found that an individual’s tendency to plan for the future plays a surprising role in people’s vaccine hesitancy.

At issue is a psychological trait called proactive coping that refers to a person’s tendency to think about and plan for the future.

“We found that the people who were least hesitant about getting vaccinated were people who were at least somewhat concerned about COVID-19 and had high scores on proactive coping,” says Shevaun Neupert, co-author of the study and a professor of psychology at North Carolina State University. “However, we also found that the people who were most hesitant about getting vaccinated also had high scores on proactive coping, but were not very concerned about contracting COVID-19.

“Basically, proactive coping seems to serve as an amplifier for vaccine hesitancy at both ends of the spectrum.”

Water quality expert develops public tool for diagnosing health of America’s streams

WVU master's degree students Samira Jahan and Md. Tanvirul Islam discuss water quality data with Omar Abdul-Aziz, associate professor in the WVU Benjamin M. Statler College of Engineering and Mineral Resources. Abdul-Aziz has publicly released a model for diagnosing the health of any U.S. freshwater stream in the past, present or future using only water temperature.
Photo Credit: Matt Sunday / West Virginia University

A model for predicting the levels of oxygen in water, developed by West Virginia University researcher Omar Abdul-Aziz, gives citizen scientists nationwide a tool for taking action on stream pollution. 

“I have been looking at water quality data for 20 years,” said Abdul-Aziz, an associate professor at the Benjamin M. Statler College of Engineering and Mineral Resources. “I can tell you that a big percentage of streams in the United States are polluted. Urban streams are getting dumpster runoff, stormwater carrying lawn fertilizers and trash. Wastewater plants aren’t necessarily treating for the dissolved organic carbon, nutrients and pharmaceuticals we’re putting into our sewage.

Abdul-Aziz’s model relies on only water temperature and pH, a measure of acidity, to give an accurate measure of the health of any freshwater stream in the contiguous United States as represented by the amount of oxygen dissolved in the water. Oxygen is fundamental to stream health, and his model is significant because it predicts how much oxygen is in the water of any given stream at any location or time, based on a small amount of easily obtainable data.

Tubular nanomaterial of carbon makes ideal home for spinning quantum bits

Artistic rendering of chemically modified carbon nanotube hosting a spinning electron as qubit.
Illustration Credit: Argonne National Laboratory

Scientists find that a tubular nanomaterial of carbon makes for ideal host to keep quantum bits spinning in place for use in quantum information technologies.

Scientists are vigorously competing to transform the counterintuitive discoveries about the quantum realm from a century past into technologies of the future. The building block in these technologies is the quantum bit, or qubit. Several different kinds are under development, including ones that use defects within the symmetrical structures of diamond and silicon. They may one day transform computing, accelerate drug discovery, generate unhackable networks and more.

Working with researchers from several universities, scientists at the U.S. Department of Energy’s (DOE) Argonne National Laboratory have discovered a method for introducing spinning electrons as qubits in a host nanomaterial. Their test results revealed record long coherence times — the key property for any practical qubit because it defines the number of quantum operations that can be performed in the lifetime of the qubit.

Does the artificial watercourse in the Hessian Ried have a Roman past?

At a site visit in the Hessian Ried
(from left): Prof. Andreas Vött, University of Mainz, Prof. Markus Scholz, Goethe University, Dr. Thomas Becker and Prof. Udo Recker, both State Service for Heritage Protection and Management Hesse.
Photo Credit: Lars Görze, State Service for Heritage Protection and Management Hesse

The Landgraben, the body of water between the German cities of Groß-Gerau and Trebur, flows into the Rhine northwest of Astheim. Its name goes back to Count Georg I (1547-1596) of Hesse-Darmstadt, to whom the origin of this artificial watercourse has been attributed until now. Archaeologists, however, suspect the waterway had a different genesis. A team from the State Service for Heritage Protection and Management Hesse and the universities of Frankfurt, Mainz and Kiel can now use the DFG's funding to research the Roman past. 

Following archaeological investigations in the Hessian Ried, initial indications show the canal may have been dug much earlier than previously estimated: It is thought the Roman military created the artificial body of water during the conquest and development of the Ried, located on the right bank of the Rhine, in the 1st century AD. The land ditch, which merged into today's Schwarzbach stream near Trebur, probably served to supply materials and goods to the Roman fort and its nearby civilian settlement in Groß-Gerau. With the new funds in hand, further research is now getting underway. 

Taking care of your teeth could help prevent chronic joint pain

Vicky Yao is an assistant professor of computer science at Rice University.
Photo by Ruth Dannenfelser/Rice University

Regular visits to the dentist might help keep joint pain at bay, too.

When Rice University computational biologist Vicky Yao found traces of bacteria associated with periodontal disease in samples collected from rheumatoid arthritis patients, she was not sure what to make of it.

Her finding helped spark a series of experiments that confirmed a connection between arthritis flare-ups and periodontitis. The study is published in Science Translational Medicine.

Tracing this connection between the two conditions could help develop therapies for rheumatoid arthritis, an autoimmune inflammatory disease that attacks the lining of the joints and can cause heart, lung and eye problems. The approach that led to the study could prove fruitful in other disease contexts, such as cancer.

“Data gathered in experiments from living organisms or cells or tissue grown in petri dishes is really important to confirm hypotheses, but, at the same time, this data perhaps holds more information than we are immediately able to derive from it,” Yao said.