PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Cicadas get a jump on cleaning

2013-04-30
(Press-News.org) VIDEO: This image shows droplets coalescing around particles before jumping off wing.
Click here for more information.

DURHAM, N.C. – As cicadas on the East Coast begin emerging from their 17-year slumber, a spritz of dew drops is all they need to keep their wings fresh and clean.

Researchers at Duke University and James Cook University in Australia have shown that dew drops can be beneficial not only in cleaning cicada wings, but other water-repellant surfaces. On these so-called superhydrophobic surfaces, dew drops "jump" by themselves, carrying away the contaminants.

A team led by Chuan-Hua Chen, Alfred M. Hunt Faculty Scholar and assistant professor of mechanical engineering and materials science at Duke's Pratt School of Engineering, demonstrated that tiny particles such as pollen can be removed from cicada wings by a phenomenon he has described as jumping droplets. When growing dew drops coalesce together, the merged drop jumps off water-repellant surfaces. The jumping motion is automatic, powered entirely by the surface energy initially stored in the dew drops.

Using a specially designed high-speed video imaging system, the engineers captured the jumping water droplets on a cicada wing, as well as the associated self-cleaning processes.

"The ability of water-repellant surfaces to self-clean has conventionally been attributed to rain droplets picking up dirt particles," Chen said. "For this conventional wisdom to work, rainfall must be present and the orientation has to be favorable for gravity to effectively remove the rain droplets. These limits severely restrict the practical use of self-cleaning superhydrophobic surfaces.

"We have found, however, that the self-propelled jumping motion of the dew drops is very effective in dislodging contaminating particles, regardless of the orientation," Chen said. "These new insights can help guide the development of man-made surfaces that are not dependent on any external forces and are therefore truly self-cleaning."

The results of Chen's research were published online in the journal Proceedings of the National Academy of Sciences. Katrina Wisdom, a Duke undergraduate and a Pratt Research Fellow in Chen's lab at the time of this study, was the paper's co-first author.

Cicadas are flying insects typically a few inches long. The most common species emerge on a yearly basis, with some U.S. species arriving every 17 years. When they dig out from underground as nymphs they molt, shedding their skin to reveal their wings. They then take flight as full-grown cicadas, spending the next four to six weeks flying around searching for and attracting mates with their distinctive song. After depositing eggs in the ground, the cicadas die and the cycle begins anew.

Cicada wings are characterized by rows and rows of tiny bumps or domes of various heights and widths. They look like upside-down ice cream cones, with the conical tips projecting upward. When a water droplet lands on this type of surface, it only touches the points of the bumps, creating pockets of air underneath the droplet. The droplet is kept aloft by this cushion of air, much like the puck in an air-hockey game.

"Most cicadas are unable to clean their own wings because of their short appendages," said Gregory Watson of James Cook University. "Furthermore, these insects commonly live in areas where there is little rain over an extended period of time. However, the areas are humid, which provides the tiny dew droplets needed to 'jump clean' their wings."

"These findings point to an alternative route to achieve self-cleaning which is fundamentally different from the conventional wisdom involving rolling or colliding droplets on a superhydrophobic surface," Chen said. "Self-cleaning surfaces using the jumping-drop mechanism can work at any orientation, which is a huge advantage for applications with unfavorable orientations with respect to gravity, such as mobile electronics and building roofs."



INFORMATION:



Chen's research is supported by the National Science Foundation, the Defense Advanced Research Projects Agency and the North Carolina Space Grant. Other members of the team were Duke's Xiapeng Qu and Fangjie Liu, as well as James Cook's Jolanta Watson.



ELSE PRESS RELEASES FROM THIS DATE:

Annals of Internal Medicine tip sheet for April 30, 2013

2013-04-30
Task Force Says Screen All Adults, Adolescents, and Pregnant Women for HIV New recommendations from the United States Preventive Services Task Force (USPSTF) urge physicians to screen all adults and adolescents aged 15 - 65 for HIV. In addition, all pregnant women should receive screening, even those who are in labor but have not yet been screened. Rapid screening tests and conventional tests are considered equally accurate for screening. In 2005, the Task Force recommended that doctors offer HIV screening to all adults and adolescents at increased risk for infection ...

Adults lack stem cells for making new eggs

2013-04-30
Baltimore, MD.—Mammalian females ovulate periodically over their reproductive lifetimes, placing significant demands on their ovaries for egg production. Whether mammals generate new eggs in adulthood using stem cells has been a source of scientific controversy. If true, these "germ-line stem cells" might allow novel treatments for infertility and other diseases. However, new research from Carnegie's Lei Lei and Allan Spradling demonstrates that adult mice do not use stem cells to produce new eggs. Their work is published by the Proceedings of the National Academy of Sciences ...

Cancer studies often lack necessary rigor to answer key questions

2013-04-30
DURHAM, N.C. – Fueled in part by an inclination to speed new treatments to patients, research studies for cancer therapies tend to be smaller and less robust than for other diseases. This raises some questions about how cancer therapies will work in practice, according to researchers at Duke Medicine, who published an analysis of nearly 9,000 oncology clinical research studies online April 29, 2013, in the journal JAMA Internal Medicine. The studies they looked at were registered on the ClinicalTrials.gov website from 2007-10. The analysis is part of the Clinical Trials ...

More evidence suggests eating omega 3s and avoiding meat, dairy linked to preserving memory

2013-04-30
MINNEAPOLIS – The largest study to date finds that eating foods that contain omega-3 fatty acids, found in fish, chicken and salad dressing and avoiding saturated fats, meat and dairy foods may be linked to preserving memory and thinking abilities. However, the same association was not found in people with diabetes. The research is published in the April 30, 2013, print issue of Neurology®, the medical journal of the American Academy of Neurology. "Since there are no definitive treatments for most dementing illnesses, modifiable activities, such as diet, that may delay ...

Relationship of medical interventions in childhood and prevalence of later intellectual disability

2013-04-30
A study by Jeffrey P. Brosco, M.D., Ph.D., of the University of Miami, Florida, and colleagues examines the relationship between medical interventions in early childhood and the increasing prevalence of later intellectual disability (ID). (Online First) Researchers reviewed medical literature and other data from 1950 through 2000 to construct estimates of the condition-specific prevalence of ID over time in the United States and Western Europe in populations of children who received a life-saving intervention within the first 5 years of life and were evaluated for ID ...

Study suggests US children born outside the United States have lower risk of allergic disease

2013-04-30
A study by Jonathan I. Silverberg, M.D., Ph.D., M.P.H., of St. Luke's—Roosevelt Hospital Center, New York, and colleagues suggests children living the in the United States but born outside the U.S. have a lower prevalence of allergic disease that increases after residing in the United States for one decade. (Online First) The cross-sectional questionnaire used for the study was distributed to 91,642 children aged 0 to 17 years enrolled in the 2007-2008 National Survey of Children's Health. The main outcomes measured were prevalence of allergic disease, including asthma, ...

SSRIs in perioperative period associated with higher risk for adverse events

2013-04-30
A study by Andrew D. Auerbach, M.D., M.P.H., of the University of California, San Francisco, suggests that receiving selective serotonin reuptake inhibitors (SSRIs) in the perioperative period was associated with a higher risk for adverse events. (Online First) The study included 530,416 patients aged 18 or older who underwent major surgery from January 2006 through December 2008 at 375 U.S. hospitals. The main outcomes researchers studied were in-hospital mortality, length of stay, readmission at 30 days, bleeding events, transfusions and incidence of ventricular arrhythmias. According ...

New subtype of ataxia identified

2013-04-30
Researchers from the Germans Trias i Pujol Health Sciences Research Institute Foundation (IGTP), the Bellvitge Biomedical Research Institute (IDIBELL), and the Sant Joan de Déu de Martorell Hospital, has identified a new subtype of ataxia, a rare disease without treatment that causes atrophy in the cerebellum and affects around 1.5 million people in the world. The results have been published online on April 29 in the journal JAMA Neurology. The cause of ataxia is a diverse genetic alteration. For this reason it is classified in subtypes. The new subtype identified described ...

Obesity in early 20s curbs chances of reaching middle age

2013-04-30
Young men who are obese in their early 20s are significantly more likely to develop serious ill health by the time they reach middle age, or not even make it that far, suggests research published in the online journal BMJ Open. It's well known that obesity in adulthood poses a risk for diabetes and cardiovascular disease, but it's not been clear whether obesity in early adulthood strengthens that risk. The authors tracked the health of 6500 Danish 22 year old men for 33 years up to the age of 55. All of them had been born in 1955, and had registered with the Military ...

Be alert to blind cord strangulation risk, parents of young children warned

2013-04-30
Window blind cords pose a particular risk of accidental strangulation for young children, doctors have warned in Archives of Disease of Childhood. Children between the ages of 16 and 36 months seem particularly vulnerable, they say. The warning comes after they treated a 22 month old boy who was brought into the emergency department. He had been found hanging on the pull chain of a window blind cord. His mother found him blue and not breathing after leaving him with his sister in a bedroom for a few minutes. He had clear strangulation marks on his neck and extensive ...

LAST 30 PRESS RELEASES:

Study shows increasing ‘healthy competition’ between menu options nudges patients towards greener, lower-fat hospital food choices

New insights into melanoma plasticity uncover a critical role of iron metabolism

A graphene sandwich — deposited or transferred?

New light-powered motor fits inside a strand of hair

Oil rig study reveals vital role of tiny hoverflies

Children’s Hospital of Philadelphia researchers boost widespread use of dental varnish across pediatric network

iRECODE: A new computational method that brings clarity to single-cell analysis

New NUS-MOH study: Singapore’s healthcare sector carbon emissions 18% lower than expected, a milestone in the city-state’s net zero journey

QUT scientists create material to turn waste heat into clean power

Major new report sets out how to tackle the ‘profound and lasting impact’ of COVID-19 on cardiovascular health

Cosmic crime scene: White dwarf found devouring Pluto-like icy world

Major report tackles Covid’s cardiovascular crisis head-on

A third of licensed GPs in England not working in NHS general practice

ChatGPT “thought on the fly” when put through Ancient Greek maths puzzle

Engineers uncover why tiny particles form clusters in turbulent air

GLP-1RA drugs dramatically reduce death and cardiovascular risk in psoriasis patients

Psoriasis linked to increased risk of vision-threatening eye disease, study finds

Reprogramming obesity: New drug from Italian biotech aims to treat the underlying causes of obesity

Type 2 diabetes may accelerate development of multiple chronic diseases, particularly in the early stages, UK Biobank study suggests

Resistance training may improve nerve health, slow aging process, study shows

Common and inexpensive medicine halves the risk of recurrence in patients with colorectal cancer

SwRI-built instruments to monitor, provide advanced warning of space weather events

Breakthrough advances sodium-based battery design

New targeted radiation therapy shows near-complete response in rare sarcoma patients

Does physical frailty contribute to dementia?

Soccer headers and brain health: Study finds changes within folds of the brain

Decoding plants’ language of light

UNC Greensboro study finds ticks carrying Lyme disease moving into western NC

New implant restores blood pressure balance after spinal cord injury

New York City's medical specialist advantage may be an illusion, new NYU Tandon research shows

[Press-News.org] Cicadas get a jump on cleaning