Excessive bed occupancy in hospitals leads to rising mortality

As shown in a new study by the University of Basel, individual empty beds do not necessarily mean a smaller burden on nursing staff.
Photo Credit: Gorden Murah Surabaya

Researchers have long suspected a link between bed occupancy and mortality in hospitals. Now, a study by the University of Basel has provided the missing data, revealing that smaller hospitals reach their capacity limit much earlier.

Since the outbreak of the coronavirus pandemic, if not before, we’ve got used to seeing figures relating to bed occupancy in Swiss hospitals in media reports. You might think that as long as there are free beds, there’s no problem. Now, a University of Basel study led by Professor Michael Simon has shown that, in some cases, the mortality rate in hospitals rises significantly before full capacity is reached.

For the study, the researchers analyzed data from over 1.1 million inpatient cases at 102 Swiss hospitals in order to investigate the relationship between bed occupancy and the 14-day mortality rate in hospitals. In other words, the cases were observed until the 14-day mark unless they were discharged earlier.

Jet engine lubrication oils are a major source of ultrafine particles

Lubrication oil in the hot exhaust plume of an aircraft engine can form ultrafine particles as soon as the plume cools down. This has now been corroborated in a study by Goethe University Frankfurt and the Hessian Agency for Nature Conservation, Environment and Geology.   
Photo Credit: Alexander Vogel, Goethe University Frankfurt

Measurements conducted by the Hessian Agency for Nature Conservation, Environment and Geology (HLNUG) in recent years have shown that Frankfurt International Airport is a major source of ultrafine particles and that these can disperse over long distances across the city. In collaboration with experts at the HLNUG, researchers at Goethe University Frankfurt have now discovered that ultrafine particles partly consist of synthetic jet oils. The research team has deduced that emissions from lubrication oils must be lowered in addition to those from kerosene in order to reduce the concentration of ultrafine particles and thus improve air quality.

Ultrafine particles form during combustion processes, for example when wood or biomass is burned, as well as in power and industrial plants. Alongside road traffic, large airports are a major source of these ultrafine particles, which are less than 100 millionths of a millimeter (100 nanometers) in size. Because they are so small, they can penetrate deep into the lower respiratory tract, overcome the air-blood barrier and, depending on their composition, cause inflammatory reactions in the tissue, for example. What's more, ultrafine particles are suspected of being capable of triggering cardiovascular diseases.

Lithium-sulfur batteries are one step closer to powering the future

Image shows microstructure and elemental mapping (silicon, oxygen and sulfur) of porous sulfur-containing interlayer after 500 charge-discharge cycles in lithium-sulfur cell.
Image Credit: Guiliang Xu/Argonne National Laboratory.

Batteries are everywhere in daily life, from cell phones and smart watches to the increasing number of electric vehicles. Most of these devices use well-known lithium-ion battery technology. And while lithium-ion batteries have come a long way since they were first introduced, they have some familiar drawbacks as well, such as short lifetimes, overheating and supply chain challenges for certain raw materials.

Scientists at the U.S. Department of Energy’s (DOE) Argonne National Laboratory are researching solutions to these issues by testing new materials in battery construction. One such material is sulfur. Sulfur is extremely abundant and cost effective and can hold more energy than traditional ion-based batteries.

In a new study, researchers advanced sulfur-based battery research by creating a layer within the battery that adds energy storage capacity while nearly eliminating a traditional problem with sulfur batteries that caused corrosion.

Joint study reveals how DNA unzipping machine works, shedding lights on cancer therapy

An initial open structure (IOS) is formed upon binding of human MCM double hexamer (hMCM-DH) to origin DNA.
Illustration Credit: Image modified from original illustration of Li et al, 2023 Cell 186, 1-14. Source/ Hong Kong University of Science and Technology

Scientists from The Hong Kong University of Science and Technology (HKUST), The University of Hong Kong (HKU) and Institut Curie, France have jointly uncovered a new mechanism of the human MCM2-7 complex in regulating replication initiation, which can be used as a novel and effective anticancer strategy with the potential for selective killing of cancer cells. The findings were recently published in the Cell journal.

Human life begins with a single fertilized egg in the mother’s womb. This egg propagates through cell divisions and develops into our multicellular body. During each cell division, our genome DNA, the blueprint of genetic information, is accurately replicated. Each cell carries roughly 2 meters of DNA organized into 23 pairs of chromosomes. In our lifetime (~70 years), our body will synthesize more than a light year’s length of DNA of ~1016 meters - the distance light travels in one year. The replication process requires the DNA duplex to be first melted and then separated into two single-stranded templates for DNA polymerases to synthesize as complement strands. Any misregulation of this process can cause dire consequences, such as tumorigenesis and inherited genetic disorders.

UC research shows people with latent tuberculosis infection are more prone to inflammation

Moises Huaman, MD, of the Division of Infectious Diseases in the Department of Internal Medicine at the UC College of Medicine
Photo Credit: University of Cincinnati

Study examines connection between inflammation, infection and cardiovascular risk

Newly published research from the University of Cincinnati finds that people with latent tuberculosis infection (LTBI) have more inflammation and could be at a higher risk for cardiovascular disease.

The research was published in Open Forum Infectious Diseases, a journal from the Infectious Diseases Society of America.

Roughly 25% of the world population has LTBI, a state where the individual has been exposed to tuberculosis but is not sick from it, says Moises Huaman, MD, of the Division of Infectious Diseases in the Department of Internal Medicine at the UC College of Medicine and corresponding author on the study.

“Developing countries have higher rates of LTBI,” says Huaman. “There are areas in the world where LTBI may affect 50% or so of the population. Here in the United States, the prevalence of LTBI is about 5%, which is still common. It is a global health problem.”

The Pacific Ocean’s oxygen-starved ‘OMZ’ is growing, new Princeton research finds

The Pacific Oxygen Minimum Zone in 3D Researchers created this visualization of the Pacific’s oxygen minimum zone from observations and the 2018 World Ocean Atlas. The colors approximately indicate the core (purple) that has almost no oxygen and is contracting, the low-oxygen outer layer (orange) that is expanding, and a transitional zone in between (pink).  
Animation Credit: by Julius Busecke in collaboration with Bane Sullivan

Areas of low-oxygen water stretch for thousands of miles through the world’s oceans. The largest of these “oxygen minimum zones” (OMZs) is found along the Pacific coast of North and South America, centered off the coast of Mexico.

Until recently, climate models have been unable to say whether OMZs will grow or shrink from climate change, in part because OMZs result from two opposing processes: oxygen supplied by ocean circulation and oxygen used by sea life.

Now, a team led by Princeton’s Laure Resplandy has confidently predicted that the boundaries of the Pacific OMZ, the planet’s largest, will expand by as much as 2 million additional cubic miles (8 million cubic kilometers) — both upward toward the sea surface and outward toward the coast — by the end of the century.

Organelles grow in random bursts

Shankar Mukherji, assistant professor of physics in Arts & Sciences
Photo Credit: Washington University in St. Louis

Eukaryotic cells — the ones that make up most of life as we know it, including all animals, plants and fungi — are highly structured objects.

These cells assemble and maintain their own smaller, internal bits: the membrane-bound organelles like nuclei, which store genetic information, or mitochondria, which produce chemical energy. But much remains to be learned about how they organize themselves into these spatial compartments.

Physicists at Washington University in St. Louis conducted new experiments that show that eukaryotic cells can robustly control average fluctuations in organelle size. By demonstrating that organelle sizes obey a universal scaling relationship that the scientists predict theoretically, their new framework suggests that organelles grow in random bursts from a limiting pool of building blocks.

The study was published Jan. 6 in Physical Review Letters.

“In our work, we suggest that the steps by which organelles are grown — far from being an orderly ‘brick-by-brick’ assembly — occur in stochastic bursts,” said Shankar Mukherji, assistant professor of physics in Arts & Sciences.

Controlled, localized delivery of blood thinner may improve blood clot treatment

Co-authors Atip Lawanprasert (left), doctoral student in biomedical engineering, Sopida Pimcharoen (center), undergraduate student in biomedical engineering and Scott Medina (right), Penn State associate professor of biomedical engineering, analyze results related to their study of combining the anticoagulant heparin with peptide to slow down the medication's delivery at the site of a blood clot.
Photo Credit: Jeff Xu / Pennsylvania State University

Heparin has long been used as a blood thinner, or anticoagulant, for patients with blood clotting disorders or after surgery to prevent complications. But the medication remains difficult to dose correctly, potentially leading to overdosing or underdosing.

A team of Penn State researchers combined heparin with a protein fragment, peptide, to slow down the release of the drug and convey the medication directly to the site of a clot. They published their findings in the journal Small.

“We wanted to develop a material that can gradually deliver heparin over time rather than the current iteration that gets cleared from the body in a couple of hours,” said corresponding author Scott Medina, Penn State associate professor of biomedical engineering. “We also wanted to deliver the drug through the skin instead of through an IV.”

When mixed, positively charged peptides and negatively charged heparin bind to create a nanogranular paste that can be injected under the skin, forming a cache of material that is then diffused in the circulatory system and travels to blood clots when they appear. The turbulent flow of fluid near a blood clot triggers the two materials to separate, allowing heparin to begin its anticoagulating action.

New study suggests Mayas utilized market-based economics

Obsidian collections from the site of Q'umarkaj and the surrounding region.
Photo Credit: Rachel Horowitz

More than 500 years ago in the midwestern Guatemalan highlands, Maya people bought and sold goods with far less oversight from their rulers than many archeologists previously thought.

That’s according to a new study in Latin American Antiquity that shows the ruling K’iche’ elite took a hands-off approach when it came to managing the procurement and trade of obsidian by people outside their region of central control.

In these areas, access to nearby sources of obsidian, a glasslike rock used to make tools and weapons, was managed by local people through independent and diverse acquisition networks. Over time, the availability of obsidian resources and the prevalence of craftsmen to shape it resulted in a system that is in many ways suggestive of contemporary market-based economies.

“Scholars have generally assumed that the obsidian trade was managed by Maya rulers, but our research shows that this wasn’t the case at least in this area,” said Rachel Horowitz, lead author of the study and an assistant professor of anthropology at Washington State University. “People seem to have had a good deal of economic freedom including being able to go to places similar to the supermarkets we have today to buy and sell goods from craftsmen.”

The brain’s ability to perceive space expands like the universe

New experiences are absorbed into neural representations over time, symbolized here by a hyperboloid hourglass.
Illustration Credit: Salk Institute

Salk researchers find that neural networks responsible for spatial perception change in a nonlinear manner and may have implications for neurodegenerative disorders like Alzheimer’s disease

Young children sometimes believe that the moon is following them, or that they can reach out and touch it. It appears to be much closer than is proportional to its true distance. As we move about our daily lives, we tend to think that we navigate space in a linear way. But Salk scientists have discovered that time spent exploring an environment causes neural representations to grow in surprising ways.

The findings, published in Nature Neuroscience show that neurons in the hippocampus essential for spatial navigation, memory, and planning represent space in a manner that conforms to a nonlinear hyperbolic geometry—a three-dimensional expanse that grows outward exponentially. (In other words, it’s shaped like the interior of an expanding hourglass.) The researchers also found that the size of that space grows with time spent in a place. And the size is increasing in a logarithmic fashion that matches the maximal possible increase in information being processed by the brain.