A new theory linking atomic disorder to heat flow offers a strong foundation for predicting thermal conductivity in materials ranging from crystals to amorphous carbon.
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Hydrogen’s role in generating free electrons in silicon finally explained
Researchers announced that they have achieved the world’s first elucidation of how hydrogen produces free electrons through the interaction with certain defects in silicon. The achievement has the potential to improve how insulated gate bipolar transistors (IGBTs) are designed and manufactured, making them more efficient and reducing their power loss. It is also expected to open up possibilities for future devices using ultra-wide bandgap (UWBG) materials.
In the global drive toward carbon neutrality, efforts to make power electronics more efficient and energy-saving are accelerating worldwide. IGBTs are key components responsible for power conversion, so improving their efficiency is a major priority. While hydrogen ion implantation has been used for about half a century to control electron concentration in silicon, the underlying mechanism has remained unclear until now.
In 2023, Mitsubishi Electric and University of Tsukuba jointly discovered a defect complex in silicon that contributes to increasing electron concentration. They confirmed that this complex is formed when an interstitial silicon pair and hydrogen bind, but the reason why free electrons are newly generated in this process was still unclear.
Chiral phonons create orbital current via their own magnetism
In a new study, an international group of researchers has found that chiral phonons can create orbital current without needing magnetic elements—in part because chiral phonons have their own magnetic moments. Additionally, this effect can be achieved in common crystal materials. The work has potential for the development of less expensive, energy-efficient orbitronic devices for use in a wide array of electronics.
All electronic devices are based upon the charge of an electron, and electrons have three intrinsic properties: spin, charge and orbital angular momentum. While researchers have long explored the use of spin as a more efficient way to create current, the field of orbitronics —based upon using an electron’s orbital angular momentum, rather than its spin, to create a current flow—is still relatively new.
“Traditionally it has been technically challenging to generate orbital current,” says Dali Sun, co-corresponding author on the study published in Nature Physics. Sun is a professor of physics and member of the Organic and Carbon Electronics Lab (ORaCEL) at North Carolina State University.
Japan wakes up world’s biggest nuclear plant 15 years after Fukushima disaster
Just under 15 years after the catastrophic nuclear accident at the Fukushima Daiichi Nuclear Power Plant, Japan has officially restarted a reactor at the world’s largest nuclear plant.
While many argue for the benefits that nuclear power can provide amid a rapidly growing climate crisis, the dangers that it poses are evident across a number of notably horrific incidents over the years.
Disasters in Kyshtym and Chernobyl have displayed the dangerous potential that a nuclear accident can cause, and few have been quite as devastating as the incident that occurred in Fukushima back in 2011.
Washington state proposes new 3D-printed gun controls with ‘blocking features’ and blueprint detection algorithm — proposal would carry sentences of five years in prison, $15,000 fine for violation
All three are explained in more detail in the bill, but arrive at broadly the same destination. This law, if approved, would prevent 3D printer brands from selling their wares in Washington State without stringent controls to prevent the printing of 3D firearms, or indeed parts that could be used to modify existing weapons.
According to the bill, violating this proposed law would be a class C felony, which means anyone found in violation of these terms could face up to five years in prison and a $15,000 fine.
Washington is not the first state to propose addressing 3D-printed firearms by way of legislation, and is unlikely to be the last. Earlier this month New York took steps to ban 3D-printed guns, proposing the mandating of 3D printer safeguards and cracking down on the sharing and possession of 3D files containing guns or gun components.
Wildfires trigger massive soil loss for decades, new global map shows
Wildfires are devastating events that destroy forests, burn homes and force people to leave their communities. They also have a profound impact on local ecosystems. But there is another problem that has been largely overlooked until now. When rain falls on the charred landscapes, it increases surface runoff and soil erosion that can last for decades, according to a new study published in Nature Geoscience.
On average, wildfires burn approximately 4 million square kilometers of land per year, an area equivalent to the size of the European Union. Despite this, there hasn’t been a global long-term assessment of how these fires affect soil erosion over time. So researchers from the European Commission’s Joint Research Center and the University of Basel, Switzerland, studied two decades’ worth of data to compile the world’s first global map of post-fire soil erosion.
The team used a sophisticated computer model called RUSLE (Revised Universal Soil Loss Equation), which they adapted for post-fire conditions to calculate how much soil moves based on factors such as vegetation cover and rainfall intensity. They combined this with satellite data of global wildfires from 2001 to 2019 and compared these areas with how the land looked before the flames took hold.
Burden of Central Nervous System Cancer in the United States
While incidence rates for central nervous system cancer remained stable from 1990 to 2021, both mortality and disability-adjusted life-years (DALYs) declined. Disparities by geography, age, sex, and sociodemographic status highlight needs for targeted health policy reforms and resource redistribution.
Findings In this cross-sectional study, analysis of the Global Burden of Disease Study 2021 data on US CNS cancers revealed that although the incidence rate remained relatively stable, both disability-adjusted life-years and mortality rates declined. However, substantial disparities persisted across geographical location, age, sex, and sociodemographic profile.
Meaning The persistent disparity in CNS cancer burden highlights the urgent need to reevaluate public health policies and redistribute health care resources to better support marginalized and underserved populations.
Contaminating plasmid sequences and disrupted vector genomes in the liver following adeno-associated virus gene therapy
A valuable paper examining the presence of AAV manufacturing contaminants in a human patient’s liver. These results will hopefully be leveraged for improving the safety of gene therapies in the future.
Analyses of liver biopsies from a child with spinal muscular atrophy treated with adeno-associated virus gene therapy who developed hepatitis reveal contaminating manufacturing plasmids and disrupted vector genomes, possibly resulting from recombination events.
Altered Molecular Composition of a Specific Subset of Prefrontal Cortical Excitatory Synapses in Schizophrenia
JNeurosci: Lorincz et al. provide novel insights into the molecular mechanisms underlying excitatory synaptic dysfunction in schizophrenia.
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Abnormal excitatory synaptic transmission in the human prefrontal cortex has been implicated in the pathophysiology of schizophrenia based primarily on genetic evidence. However, changes in synaptic function cannot be predicted from altered gene expressions, but determining the amount, density, and subsynaptic distribution of synaptic proteins is the only reliable indirect readout of function. Detecting proteins in individual synapses of human postmortem tissues has been severely constrained by technical limitations. Here we overcome this limitation by optimizing a high-resolution, quantitative localization method to facilitate antigen recognition at excitatory synapses in postmortem brains of both sexes.