时间:2019-01-03 作者:英语课 分类:2018年VOA慢速英语(四)月


英语课

Daylight Turns Thin Plastic Barrier into Germ-Killing Material


Daylight-powered germ-killing equipment may someday help protect health workers from deadly microorganisms like Ebola virus disease.


That is a finding from a study published in the journal Science Advances.


Study organizers say they have developed membranes that produce very small amounts of hydrogen peroxide when they are left in sunlight.


Membranes are thin structures that can serve as barriers. They let some things pass through, but other things are blocked. Hydrogen peroxide, a liquid sold in drug stores, works as a disinfectant.


Nearly 500 health workers died in 2014 when Ebola spread through parts of West Africa. Caregivers wear full-body protective suits when they come into contact with patients with infectious diseases. But the process of removing the suits is a time when infection can spread if the surface is covered with microorganisms.


"If there's any live bacteria or virus on the surface, it's still transmissible and could cause infection," said Gang Sun of the University of California, Davis. He is one of the researchers that worked to develop membranes that could cover the outside of protective equipment.


When the chemical molecules on the surface of these membranes are put in sunlight, they react with oxygen in the air to produce small amounts of hydrogen peroxide.


Gang Sun explains that the process creates less hydrogen peroxide than what you would use to remove dirt on clothing, for example. But it is still enough to kill organisms.


Rohan Tikekar is a food scientist with the University of Maryland. He described the development as “quite novel,” or new and different. Tikekar was not involved with the recent study.


He said others have developed materials that produce disinfecting chemicals. But most only work under high-energy ultraviolet (UV) light, and not usual daylight.


The new membrane also works in the dark for at least an hour or two because of chemical properties that can recharge its germ-killing powers. Tikekar called that an important improvement.


Gang Sun said the new membranes could be used for things other than protective gear for health workers. They could also be added to packaging for fruits and vegetables to keep foods fresher and reduce the risk of contamination.


Some versions of the material use natural chemicals. Sun says that one of the next steps is to make it safe to eat.


I'm Jonathan Evans.


Words in This Story


germ – n. an organism known to cause disease


journal – n. a publication, such as a magazine or newspaper


packaging – n. material used to contain something


transmissible – adj. able to be spread to other people


approach – n. a method; a way of doing things


novel – adj. new or unusual


contamination - n. the process of polluting; the act of harming something



学英语单词
adhesive composition
advertising strategy
aluminum foil with paper backing
antenna choke coil
autosplenectomy
bench technique of kidney
bewrapping
bite one's thumb at someone
bitter
Brigantia
business association
buttress spacing
cant chisel
cased hole
cast up-hill
centuriator
chalk bags
chewstick
circulating type oil supply
clear cell syringoma
color of the mature pods
combinational (boolean) function
conditioned vascular reflex
constructional organization design
copperose
counting-rate-difference meter
cylindraceus
data digit
digital videotape recorder
doxorubicine
dry damping
enter the lists against
epinephelus
expert criteria
far infrared gear
fill opening
Five percent rule
flux differential relay
force of attraction
front spring
fuundament
gate-keepings
generator voltage regulator
Gilman
graphic position finding
gyrotedder hay conditioner
Harvey Wallbanger
I'll say
iminoethyl
Insect-sting
itinerant worker
Jack Bauer
jkelso
light tank turret
lime cake drainage
limitlessly
low permeable
modulation doped heterojunction
multi level control
multiprocessing executive control
net value cost
nonirritating
nyoongar
observational language
one-dimensional structure
optoacoustic transducer
parabolic beam transmission
parentification
petaliters
physiological response
pick sb's brains
pignose turtle
pityriasis lichenoides acuta
ponceing
Port Phillip Bay
program instruction frequency analyzer
Put a cork in it!
Redruth
rickburner
rncm
rubiverine
santite
schwartzs
shading yellow
smallens
subseptus
sulfhydrylase
take auspices
tent-poling
theosine
thump-up
tindalo
tool of production
track steward
Trapa manshurica
tri-cut
tunka
vagitarian
Vimtrump's cells
wire-rod concave
wvu
zony