valves

Development of portable infectious disease detector

..., puttingmicroscopic arrays of channels, pumps and valves to move around minuteamounts of liquid on silicon ...ave adapted a method for molding micro-channelsand valves into a material similar to that used in soft contact lenses.This has given them the capability to ca...

UCSD team discovers specialized, rare heart stem cells in newborns

...c tissue grafts, and artificial and animal derived valves to surgically repair heart defects. While progenitor cells won't grow a whole new heart, our research has shown that they can spontaneously become cells from specific parts of the heart by simple co-exposure to other heart cells, which could augment ...

Stem cells' electric abilities might help their safe clinical use

...ur discovery of functional ion channels, which are valves in a cell's outer membrane allowing the passage of charged atoms, the basis of electricity, provides an important link to the differentiation, or maturation, and cell proliferation, or growth of human ESCs." Because human ESCs can potentially provid...

Why Christmas trees are not extinct

...not only survive but thrive: efficient microscopic valves let water flow through conifers about as easily as...ry says that if conifers had not evolved easy-flow valves to make up for the short length of their water pipes or conduits, "it is doubtful they could hold th...

Researchers develop portable 'vein finder' for faster, more accurate injections

...sticated ultrasound systems to evaluate the heart, valves and vessels for general blood-flow studies. But this kind of equipment is impractical and too costly for field use. "Although the use of Doppler technology isn't new, the novel aspect of our vein finder is the system's design, which makes it both po...

Bone and cartilage growth to blame for heart valve disease

... Medicine, who examined diseased mitral and aortic valves removed during surgery for the study. "Common wis...nity has always been that thickening of the mitral valves was part of the aging process as deposits of calcium, a mineral found in the blood, built up on the ...

Study shows pine bark naturally decreases severe chronic venous insufficiency

...researcher of the study. "Eventually, some of the valves cannot hold the weight of excessive blood, which then adds more pressure onto the next valve further downwards. Ultimately, the inability to prevent the liquid in the blood from seeping into the tissue is what causes edema, a common condition of CVI...

How blood flow dictates gene expression

...the high-flow side of developing mitral and aortic valves in the heart of a 14-day-old embryo. The researchers surmise that the mechanical stimulus of blood flowing in a vessel leads to the upregulation of Klf2, which either activates or represses genes that control smooth muscle tone, that is the calibe...

Researchers show that veins stiffen as we age

...d back to the heart. The veins are equipped with valves to prevent any backflow of blood caused by gravity as blood is returned to the heart from the lower extremities. The walls of the veins are made of collagen and elastin, two proteins that give the tube-like blood vessels flexibility and help them to ...

Engineering the heart piece by piece

...g their attack. Children born with defective heart valves might get new ones that can grow in place, rather ...eering?entire areas of the heart, as well as heart valves and major blood vessels. But hurdles still remain before the products of this tissue engineering...

Microfluidic chip helps solve cellular mating puzzle

...computer-controlled fluid pressure and microscopic valves allow the researchers to isolate and conduct experiments on extremely small clusters of cells. "The level of control we can achieve on the conditions affecting just a few cells is unbelievable," Levchenko said. "This is far beyond what you can do in ...

Natural polyester makes new sutures stronger, safer

...tificial scaffold that could be used to grow heart valves after being implanted in a patient, which would spare children with heart valve defects from undergoing repeated surgeries. Tests of the device in animals have shown promise. "We've been able to show we can produce a valve scaffold that functions ...

Magnetic computer sensors may help study biomolecules

...ndom access memory (MRAM) for biosciences. Spin valves are made by stacking thin layers of materials with...k silicon nitride membrane in fluid. When the spin valves are turned on, a local magnetic field is created that is strongest near the ends of the magnetic sta...

Percutaneous aortic valve replacement safe, successful in high-risk patients

...g in the replacement of narrowed, calcified aortic valves in patients too sick to withstand open-chest surgery. According to a study reported at the 30th Annual Scientific Sessions of the Society for Cardiovascular Angiography and Interventions (SCAI), May 9?2, 2007, in Orlando, FL, patients who were treate...