Mosquitoes are perhaps useful for something after all, besides feeding frogs. Along with his colleagues at Osaka's Kansai University, mechanical engineer Seiji Aoyagi has created an almost pain-free hypodermic needle that is based on a mosquito's proboscis. Perhaps surprisingly, the needle's patient-friendliness comes from the fact that its outer surface is jagged, not smooth.
While mosquito bites definitely do itch, the itching only occurs after the feeding is complete, due to bacteria in the anticoagulant injected by the insects. The initial "bite" itself can barely be felt. How is this possible?
A mosquito's proboscis includes an internal tubular labrum (that does the bloodsucking), which is sheathed between two serrated maxillae – one on either side. The maxillae are what first penetrate the skin and then sink into it, after which the labrum slides down between them. Because the maxillae have a jagged outer surface, they present a minimum amount of surface area to nerves in the skin. A smooth steel hypodermic needle, by contrast, makes contact with a maximum number of nerves, and is therefore uncomfortable.
Professor Aoyagi's needle, etched from silicon, mimics the labrum and maxillae. Two harpoon-like jagged-edged outer shanks first penetrate the skin, after which a smooth drug-delivering/blood-taking tube moves down between them, only touching the patient at its sharpened tip. Mosquitos vibrate their proboscis to help the maxillae ease down through the tissue, which Aoyagi has also copied – each of the three parts of his device are vibrated by tiny piezoelectric crystal motors at around 15 hertz.
The needle in its present form is tiny, at just one millimeter in length, 0.1 millimeters in diameter, and with walls a mere 1.6 micrometers thick. It is attached to a five-millimeter-wide tank, designed for storing fluids that the needle collects. To test the needle, Aoyagi's Kansai team used it to puncture silicone rubber with a skin-like resistance, underneath which was a container of red dye. The needle successfully drew the dye into its tank.
When tested on humans, the test subjects stated that it was much less painful than a traditional hypodermic, but that what discomfort there was lasted longer. Aoyagi believes that by copying more of the mosquito's seven mouthparts, including a system to steady the needle as it enters the skin, that discomfort could be further reduced in future versions.
He hopes that the needle could eventually be used to draw samples in labs, or that it could lead to the development of small wireless monitoring devices, which would be permanently attached to the bodies of people such as diabetics.
2011年10月9日星期日
2011年9月5日星期一
Afternoon police update has tools stolen, assault on officer
David Benitez Sr., 41, of the 2300 block of South 2nd Street was arrested Friday on charges of aggravated assault and possession of a weapon for unlawful purposes.
Tracey P. Lamb Sr., 48, of Oakview apartments at East Broad Street and Wade Boulevard was arrested Friday on charges of theft and conspiracy.
Loman Edward Mays, 42, of the 300 block of East Broad Street was arrested Friday at ShopRite on North 2nd Street on a shoplifting charge.
Brittany N. Lane, 22, of the 200 block of West Main Street was arrested Friday on charges of shoplifting, possession of drug paraphernalia and possession of a hypodermic needle.
Robert McNair, 34, of the 800 block of Cedar Street was arrested Friday on a contempt warrant.
Police are investigating a burglary early Friday morning on Louis Drive. Stolen were a Kohler Courage power washer, a 16-inch chainsaw, a leaf blower and bagger, a Black and Decker Weedwhacker, an electric Black and Decker cultivator, a 21-inch Lawn Boy push mower and numerous hand tools including sockets, wrenches, drill and a circular saw.
Irwin Krakow was arrested Friday at Walmart on North 2nd Street on a shoplifting charge. He also was wanted on a Millville warrant.
An Eastern model bicycle was reported stolen Saturday from a house at 6th and Oak streets. Four young males were involved.
Lawrence Conquest, 48, of Louis Drive was arrested Saturday on a simple assault charge.
Reuben Devine, 40, of the 400 block of East Broad Street was arrested Saturday at North 4th and East Pine streets on charges of simple assault on a law enforcement officer, evidence tampering, obstruction, resisting arrest, loitering and possession of a controlled dangerous substance.
Family Dollar Store on North 2nd Street reported Sunday that a man stole a pink bookbag filled with merchandise.
Rite Aid on North High Street reported early Monday morning that a man walked out without paying for five bottles of shampoo.
Tracey P. Lamb Sr., 48, of Oakview apartments at East Broad Street and Wade Boulevard was arrested Friday on charges of theft and conspiracy.
Loman Edward Mays, 42, of the 300 block of East Broad Street was arrested Friday at ShopRite on North 2nd Street on a shoplifting charge.
Brittany N. Lane, 22, of the 200 block of West Main Street was arrested Friday on charges of shoplifting, possession of drug paraphernalia and possession of a hypodermic needle.
Robert McNair, 34, of the 800 block of Cedar Street was arrested Friday on a contempt warrant.
Police are investigating a burglary early Friday morning on Louis Drive. Stolen were a Kohler Courage power washer, a 16-inch chainsaw, a leaf blower and bagger, a Black and Decker Weedwhacker, an electric Black and Decker cultivator, a 21-inch Lawn Boy push mower and numerous hand tools including sockets, wrenches, drill and a circular saw.
Irwin Krakow was arrested Friday at Walmart on North 2nd Street on a shoplifting charge. He also was wanted on a Millville warrant.
An Eastern model bicycle was reported stolen Saturday from a house at 6th and Oak streets. Four young males were involved.
Lawrence Conquest, 48, of Louis Drive was arrested Saturday on a simple assault charge.
Reuben Devine, 40, of the 400 block of East Broad Street was arrested Saturday at North 4th and East Pine streets on charges of simple assault on a law enforcement officer, evidence tampering, obstruction, resisting arrest, loitering and possession of a controlled dangerous substance.
Family Dollar Store on North 2nd Street reported Sunday that a man stole a pink bookbag filled with merchandise.
Rite Aid on North High Street reported early Monday morning that a man walked out without paying for five bottles of shampoo.
2011年4月28日星期四
The Needle: Trees and Leaves Edition
Outfoxed: When President Barack Obama and First Lady Michelle Obama went to Shiloh Baptist Church for Easter services, it should have been a boon for the Shaw house of worship—publicity is always nice, after all, and a presidential visit brings a lot of good publicity. And also, apparently, a lot of hate mail. After the Obamas visited, Fox News Channel's Sean Hannity apparently decided to make Shiloh Baptist's pastor, the Rev. Wallace Charles Smith, into the next Jeremiah Wright in the right-wing imagination. The church has now received death threats, faxes with monkey images, and vulgar phone calls. Happy Easter! -3
Twist and Shout: The horrific weather responsible for killing more than 100 people across the South moved through the D.C. region last night and today; tornadoes were spotted in Virginia and Maryland counties, and a watch extended over the entire area for most of the day. Mayor Vince Gray sent condolences on behalf of the District. If a tornado had devastated D.C., we don't think it would make us feel much better if the mayor of Huntsville, Ala., sent along a note. But it's always nice to be polite. -2
Mow the Lawn—Or Else: The smell of freshly cut grass isn't just a nice luxury in the summertime; starting this weekend, it's also mandatory. D.C. government officials can fine homeowners whose lawns reach heights of 10 inches or more up to $500. A few years ago, the District issued 1,400 citations. (Note: Mowing the Gray administration's "D.C. One City" slogan into the lawn, while encouraged, is technically optional.) +1
Trick or Tree: Meanwhile, though the city is quite careful to patrol your treatment of your lawn, it's not so good with its own flora. Casey Trees just gave the District a C for its tree care, dropping from last year's B- mostly because D.C. officials took $539,000 from a tree fund to cover budget shortfalls. The city's records have apparently lost track of 10,000 trees planted since 2002—so no one even knows whether they're alive. Or for that matter, if they were planted at all. Which reminds us of the famous Zen koan: If a tree is planted in the city, and no one writes it down, does it make a sound?
Twist and Shout: The horrific weather responsible for killing more than 100 people across the South moved through the D.C. region last night and today; tornadoes were spotted in Virginia and Maryland counties, and a watch extended over the entire area for most of the day. Mayor Vince Gray sent condolences on behalf of the District. If a tornado had devastated D.C., we don't think it would make us feel much better if the mayor of Huntsville, Ala., sent along a note. But it's always nice to be polite. -2
Mow the Lawn—Or Else: The smell of freshly cut grass isn't just a nice luxury in the summertime; starting this weekend, it's also mandatory. D.C. government officials can fine homeowners whose lawns reach heights of 10 inches or more up to $500. A few years ago, the District issued 1,400 citations. (Note: Mowing the Gray administration's "D.C. One City" slogan into the lawn, while encouraged, is technically optional.) +1
Trick or Tree: Meanwhile, though the city is quite careful to patrol your treatment of your lawn, it's not so good with its own flora. Casey Trees just gave the District a C for its tree care, dropping from last year's B- mostly because D.C. officials took $539,000 from a tree fund to cover budget shortfalls. The city's records have apparently lost track of 10,000 trees planted since 2002—so no one even knows whether they're alive. Or for that matter, if they were planted at all. Which reminds us of the famous Zen koan: If a tree is planted in the city, and no one writes it down, does it make a sound?
订阅：
博文 (Atom)