Physics tip sheet #35

July 11, 2003

1) Heartbeat analysis gives clues to mortality rate
P. Allegrini, et al
Physical Review E (print issue vol. 67, June 2003)

A new paper has added diagnostic capability to an earlier study of heartbeat analysis among congestive heart failure patients. The original 2002 paper, also published in Physical Review E, suggested that the heartbeat patterns of healthy patients were significantly different from those of patients with congestive heart failure, but the study lacked the relevant clinical data needed to give it diagnostic importance. Clinical data has since been made available to the researchers, who have published an addendum to the original paper, giving it a firmer theoretical basis and claiming that the heartbeat patterns of patients with congestive heart failure can be used to determine their mortality risk.

Brief Report:
Original paper:

2) New type of superconductor
H.J. Niu and D.P. Hampshire
Physical Review Letters (to appear)

By taking conventional superconducting materials, smashing them into little pieces, gluing them back together and then cooking them, researchers have found a new type of superconductor that carries more current and remains superconducting in a much higher magnetic field than conventional superconductors. The researchers speculate the new superconducting materials can be used to make magnets that produce higher magnetic fields and MRI scanners will be able to use them to produce a sharper picture.

Journal article: Available to journalists on request

3) From nanobubbles to clouds
M. Moody and P. Attard
Physical Review Letters (to appear)

The growth of water droplets to form clouds belongs to the same class of phenomena as the separation of alloy components upon ageing; the decomposition of binary mixed fluids; and the formation of bubbles from a supersaturated or superheated solution. In all cases, the growth rate is limited by the surface energy of the droplet. The authors have developed a new computer simulation to evaluate the surface tension of supersaturated interfaces and showed that the supersaturation of the atmosphere decreases the surface tension from its usual coexistence value.

Journal article: Available to journalists on request

4) Carbon nanotube transistors: size doesn't matter
S. Wind, J. Appenzeller, P. Avouris
Phsyical Review Letters (to appear)

Smaller transistors usually perform better, a fact that has driven the semiconductor industry to shrink the size of silicon transistors by a factor of two approximately every three years. It is anticipated that in about 15 years, they will have become too small to be turned off. Carbon nanotubes are the leading candidate to replace silicon, having already been shown to carry more current per unit of width. It has so far been difficult to say what happens when they are made shorter, because the switching action in a nanotube transistor depends on the properties of the metal contacts rather than on the nanotube itself. This paper describes a new type of carbon nanotube transistor in which the flow of current in the nanotube can be switched on and off independently of the metal-nanotube contacts, allowing the researchers to study the properties of different length transistors. They found the current in the nanotube was the same regardless of length, meaning that electrons move along the nanotube channel unimpeded. This explains why nanotube transistors perform so well and suggests that, for nanotubes, size doesn't matter.

Journal article: Available to journalists on request

American Physical Society

Related Mortality Rate Articles from Brightsurf:

Mortality rate higher for US rural residents
A recent study by Syracuse University sociology professor Shannon Monnat shows that mortality rates are higher for U.S. working-age residents who live in rural areas instead of metro areas, and the gap is getting wider.

Viral load predicts mortality rate in hospitalized patients with cancer and COVID-19
Higher viral loads are associated with a greater risk of death among cancer and non-cancer patients hospitalized with coronavirus disease 2019 (COVID-19), researchers report September 15 in the journal Cancer Cell.

New analysis shows hydroxychloroquine does not lower mortality in COVID-19 patients, and is associated with increased mortality when combined with the antibiotic azithromycin
A new meta-analysis of published studies into the drug hydroxychloroquine shows that it does not lower mortality in COVID-19 patients, and using it combined with the antibiotic azithromycin is associated with a 27% increased mortality.

What's the best way to estimate and track COVID-19 mortality?
When used correctly, the symptomatic case fatality ratio (sCFR) and the infection fatality ratio (IFR) are better measures by which to monitor COVID-19 epidemics than the commonly reported case fatality ratio (CFR), according to a new study published this week in PLOS Medicine by Anthony Hauser of the University of Bern, Switzerland, and colleagues.

Study finds cancer mortality rate disparity based on hospital ratings
A new paper in the JNCI Cancer Spectrum, published by Oxford University Press, finds that the mortality rates for complex cancer procedures differ greatly between one-star hospitals (10.4%) and five-star hospitals (6.4%).

COVID-19: Bacteriophage could decrease mortality
Bacteriophage can reduce bacterial growth in the lungs, limiting fluid build-up.

Mortality rate is cut in half by a lung rescue team at Massachusetts General
A specialized Lung Rescue Team established to evaluate and treat patients with obesity receiving mechanical ventilation due to acute respiratory failure has significantly reduced the risk of mortality

Highest mortality risks for poor and unemployed
Large dataset shows that income, work status and education have a clear influence on mortality in Germany.

Addressing causes of mortality in Zambia
Despite the fact that people in sub-Saharan Africa are now living longer than they did two decades ago, their average life expectancy remains below that of the rest of the world population.

Mortality rate 'weekend effect' not a reliable measure of care quality in hospitals
The higher mortality rate for weekend hospital admissions should not be used as an indicator of quality of care due to the lack of data preceding patient admission and on the severity of their illness, a new study conducted at the University of Warwick Medical School has concluded.

Read More: Mortality Rate News and Mortality Rate Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to