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
abranchial
active carbon ?
al hadhalil plat.
Alloca
annual cutting area
aptitude-treatment
atonic dyspepsia
B and T
berlaken
blaya
body refuse
bricker
checkouts
Chincoteague Island
chitterings
chordwise component
close defect
coccygeal pain
concentric sclerosis
coordinated wage policy
copperized lead
costimulant
Court-Saint-Etienne
craggly
dense pubescent types
dicyanoargentate
Dudarevskiy
electric defrost
encounter a complete defeat
end-of-file operation
enpiroline
enteroenteric
excess voltage protection
extremal statistic
fluvial sand
freiers
front-mounted toolbar
gene-napper
GF
glovemaking
hand-prosthesis
high-calorie
housej property management
hyperite (gabro-norite)
leek moth
lig. menisci fibularis
linear cumulative damage
little barleys
livedo reticularis symptomatica
lung counter
make sunset
minkishi
mosh pits
moss families
n. occipitalis minor
nanum
nasal superior quadrant
non-precision-instrument runway
nonconfident
nonsilence
Norheimsund
normocholesterolaemic
octil
orthorhombicity
P54C
peptidyl site
pexborate
platen-pressed particle board
praetorian
pressure-sensitive vehicle detector
production accident
propeller disc
Psyllidae
Pyramon
QKt, Qk
recirculating cooling water
relesse
runway condition report
Sainjang
salary structure
scheme of compromise or arrangement
sclaffed
Sedum truncatistigmum
segment-gear
selfsetting die
senile warts of lid
situation board
skeletal structures
slimlining
slow ahead starboard
space cadet
specif.
spitting image
squeeze-box
superior maxillary branch (or maxillary nerve)
system trap
telemetering data receiving set
touchier
tree-structured
turnbuckle screw
wet-fed cement kiln
you got it