Modular Add-On Brings Polarized Light Microscopy, Malaria Diagnosis to Smartphones

Researchers at Texas A&M University have developed a novel point-of-care device for field-based diagnosis of malaria using a smartphone. The mobile-optical-polarization imaging device (MOPID) attaches to smartphones or tablets and co-opts the camera to detect birefringent hemozoin in histological samples, which is indicative of malarial infection.

Despite advances in diagnostic approaches and treatment, malaria remains one of the leading sources of disease and death in developing nations. The “gold standard” of detection, evaluation of Giemsa-stained blood smears via bright-field microscopy, often requires skilled technicians and laboratory environments that are few and far between in the regions that are most in need. Even when available for field-testing, white light microscopy tends to report many false positive diagnoses as well. Bench-top polarized light microscopy systems, while more definitive, are large, expensive pieces of equipment that are complex to operate, and to maintain as well.

The MOPID, though, appears to offer a highly-mobile and effective alternative, at a cost that should be palatable in underserved countries. The device in its current form has demonstrated imaging properties that compare favorably with a reference Leica DMLM polarized microscope – a resolution of 1.05 μm, system magnification in the range of 50x, and field of view measuring 0.78 mm x 0.79 mm.

Going forward towards release and dissemination of the technology, the group is currently concentrating on preparing units for in vivo field-testing in Rwanda. To do so, they will be taking efforts to lower the physical profile of the device, improve upon human factors engineering and user-interface components, and lower costs. The ultimate vision is for each MOPID diagnostic test to be priced under $1.00 per result, anywhere in the world.

The MOPID device marks another in a series of recent mobile device imaging innovations that are empowering clinicians and researchers without access to traditional acquisition tools (see our recent post on the smartphone-powered D-EYE Digital Ophthalmoscope or read about technology pioneer Jonathan Rothberg’s plan to bring ultrasound to mobile devices).

Study in Scientific Reports: Malaria Diagnosis Using a Mobile Phone Polarized Microscope…

ORIGINAL: Medgadget

ZACH KAUFMAN

SEPTEMBER 4TH, 2015 

Making polymers from a greenhouse gas

A future where power plants feed their carbon dioxide directly into an adjacent production facility instead of spewing it up a chimney and into the atmosphere is definitely possible, because CO2 isn't just an undesirable greenhouse gas; it is also a good source of carbon for processes like polymer production. In the journal Angewandte Chemie, American scientists have now introduced a two-step, one-pot conversion of CO2 and epoxides to polycarbonate block copolymers that contain both water-soluble and hydrophobic regions and can aggregate into nanoparticles or micelles.

CO2 and epoxides (highly reactive compounds with a three-membered ring made of two carbon atoms and one oxygen atom) can be polymerized to form polycarbonates in reactions that use special catalysts. These processes are a more environmentally friendly alternative to conventional production processes and have already been introduced by several companies. However, because current CO2-based polycarbonates are hydrophobic and have no functional groups, their applications are limited. In particular, biomedical applications, an area where the use of biocompatible polycarbonates is well established, have been left out.

A team led by Donald J. Darensbourg along with graduate student Yanyan Wang at Texas A&M University (USA) has provided a solution. For the first time, the researchers have been able to produce amphiphilic polycarbonate block copolymers in which both the hydrophilic and hydrophobic regions are based on CO2. They were also able to incorporate a variety of functional and charged groups into the polymers. Because it is very difficult to find building blocks to make hydrophilic polycarbonates, the researchers used a trick: they polymerized first and attached the water-soluble groups afterwards.

The entire process is even a "one-pot reaction": The researchers first produce the hydrophobic regions by polymerizing CO2 and propylene oxide (as the epoxide component). In the same vessel, they then change to a different building block, allyl glycidyl ether (AGE), an epoxide with a double bond in its side chain, and continue the polymerization. The AGE-containing polymer grows on both ends of the existing polycarbonate, leading to a triblock copolymer. The length of the blocks can be controlled precisely. Subsequently a "thiol–ene click reaction" can be used to simply "click" a water-soluble group into place at the double bond. This makes it possible to attach acidic and/or basic groups that carry a positive or negative charge in certain pH ranges. Some of the amphiphilic polycarbonates made by this method are able to aggregate into particles or micelles in a self-organization process. This, and the ability to attach bioactive substances, for example, could provide many more possibilities for biomedical applications.

Explore further:  

Bristly Spheres as Capsules

More information: "Construction of Versatile and Functional Nanostructures Derived from CO2-based Polycarbonates." Angew. Chem. Int. Ed.. doi: 10.1002/anie.201505076


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Absurd Creature of the Week: 10-Foot Bobbit Worm Is the Ocean’s Most Disturbing Predator

ORIGINAL: Wired

By Matt Simon
09.06.13

Image: Wikimedia

If I could go back to my childhood I would have never waited for rainstorms to flush out all of the earthworms for me to grab, place on leaves, and send down the flooded gutters into the sewers. I thought it was a funny race. But now I wish I could take it all back. Because in tropical oceans there exists a worm that could violently avenge its relatives.

This is Eunice aphroditois, also known as the bobbit worm, a mix between the Mongolian death worm, the Graboids from Tremors, the Bugs from Starship Troopers, and a rainbow — but it’s a really dangerous rainbow, like in Mario Kart. And it hunts in pretty much the most nightmarish way imaginable, digging itself into the sea floor, exposing a few inches of its body — which can grow to 10 feet long — and waiting.

Using five antennae, the bobbit worm senses passing prey, snapping down on them with supremely muscled mouth parts, called a pharynx. It does this with such speed and strength that it can split a fish in two. And that, quite frankly, would be a merciful exit. If you survive initially, you get to find out what it’s like to be yanked into the worm’s burrow and into untold nightmares.

A mix between the Mongolian death worm, the Graboids from Tremors, the Bugs from Starship Troopers, and a rainbow.

“What happens next is rather unknown, especially because they have not been observed directly,” Luis F. Carrera-Parra and Sergio I. Salazar-Vallejo, ecologists specializing in annelid polychaetes at El Colegio de la Frontera Sur (ECOSUR) in Campeche, Mexico, wrote in a joint email to WIRED. “We think that the eunicid injects some narcotizing or killing toxin in their prey animal, such that it can be safely ingested — especially if they are larger than the worm — and then digested through the gut.”

Before we go any further, let’s just go ahead and get this out of the way. The bobbit worm may or may not be named after John Bobbitt, whose misadventures won’t be elaborated on here. The story goes that an underwater photographer saw the worm’s powers of … amputation as being analogous to those of John’s wife Lorena. But according to Anja Schulze, a marine biologist at Texas A&M University at Galveston, the origin of the name is far from clear.

In fact, scientists can’t seem to agree on how to even classify the thing. “We might actually have not just different species, but different genera of these worms,” Schulze said. “The color patterns can vary quite a bit, and we really don’t know how many species it refers to.” Complicating matters is the preservation process. According to Schulze, pickled specimens available to scientists have been soaking in formalin or ethanol, which leaches out their gorgeous iridescent color.

And marine biologists don’t come across bobbit worms too often in the wild, Schulze says. But every once in a while one just appears in an aquarium, like a kraken, ready to make a mess of things, as if Liam Neeson himself ordered it into existence. Indeed, it has become the bane of many an aquarist. When folks introduce live rocks — which are actually skeletons of dead coral — into their saltwater aquariums, a teeny-tiny bobbit worm can come along for the ride. But they don’t stay small for long.

Bobbit worms can tuck themselves away among coral and decimate an aquarium, picking off fish one by one, which you can imagine is quite confusing for the owner, since contrary to the events in Finding Nemo, fish typically don’t just disappear. And they can even take the pros by surprise. When a public aquarium in England was having a problem with mysteriously maimed fish and even corals, they set out bait night after night, which disappeared, hooks and all. Staffers eventually had to dismantle the exhibit, finding a 4-foot bobbit worm named Barry (presumably they gave him this name — he probably hadn’t always gone by Barry).

A Daily Mail story about Barry suggested that the bobbit worm can permanently paralyze human appendages with its bristles, though Carrera-Parra and Salazar-Vallejo question this. They say a different family of worms, the fireworms, have harpoon-shaped chaetae — bristles of sorts — that release a toxin that can cause severe skin irritation, but bobbit worms “do not have abundant chaetae and their chaetae are not used for defensive purposes, but for improving traction for crawling over the sediment or inside their galleries or tubes.”

And as for reproduction, the bobbit worm’s habits remain a mystery. But Carrera-Parra and Salazar-Vallejo look to the somewhat troubling rituals of its relatives for insight into what could be going on. Gentlemen, take it away.

“Some eunicid polychaetes have an impressive transformation of their body for reproduction. The posterior part of their bodies are modified to contain sperm or oocytes and often have a large eyespot. During a very short period of time, depending on the season and under the influence of a certain phase of the moon, these posterior regions, or even the whole body, leave their shelter and swim en masse to the surface of the sea. This swarming behavior concludes with the massive release of sperm and eggs such that fecundation can be done.”

Hate to leave you with the image of a beautiful tropical ocean swarming with sex-crazed 10-foot-long worms with hair-trigger jaws, but that’s totally happening now.