valve

Implanted Devices Detect High-Risk Heart Failure Patients

...e, high blood pressure, previous heart attacks and valve problems. An estimated 4.7 million Americans suffer from the condition, with 400,000 new cases reported each year. Roughly one-half of patients die within five years of diagnosis. Although there is no cure, drugs can improve the strength of the hear...

Why Christmas trees are not extinct

...ng through microscopic pores. But in conifers, the valve membranes have what is known as "torus-margo" stru...t they compensate for that because each individual valve is so much more efficient," Sperry says. "The flow resistance through a valve of a given size is 59 ...

Sun protection for plants

...s in these membranes. This unique nanoscale safety valve prevents plant damage by harmlessly dissipating the lethal excess radiation. This photoprotective process was found to be aided by a special carotenoid molecule called zeaxanthin and plants with higher levels of this molecule appear to be better prot...

Bone and cartilage growth to blame for heart valve disease

...ve rather than passive process that leads to heart valve degeneration, furthering a Northwestern researcher...the medical community's beliefs about the cause of valve disease. Heart valve disease is caused not by a 'wear and tear' phenomenon, but by an inflammatory ...

Chocolate, wine, spicy foods may be OK for heartburn, Stanford study finds

...e exerted by the esophageal sphincter, the control valve that keeps the food you've swallowed and your digestive acids down in your stomach, where they belong. Heartburn is most commonly caused when the esophageal sphincter relaxes more often than it is supposed to, allowing stomach acid to flow up into t...

New GI technologies improve internal organ visualization

...m, researchers punctured the myocardium and aortic valve or coronary artery in the six pigs; three received angiography and three received thermal ablation, or clearing of the aortic valve. The repeat puncture of the cardiac walls and injection of contrast to help visualize the tissues showed no complicat...

Sticky surfaces turn slippery with the flip of a molecular light switch

...a protein filter for biological mixtures to a tiny valve on a "lab-on-a-chip." Synthetic polymer membranes...at the new material could be employed as a surface valve that can be opened and closed by applying light, offering the ability to control liquid flow in a ch...

Study shows pine bark naturally decreases severe chronic venous insufficiency

...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." Researchers at L'Aquila University in Italy conducted a comparative analysis by supple...

Making a face: A new and earlier marker of neural crest development

...l nervous system. In humans, cleft palate, heart valve malformations and various tumors are among the common malformations associated with disruption of neural crest development. Chick embryos have well-characterized stages and are a valuable model for examining vertebrate development. While it was kn...

Light-sensitive photoswitches could restore sight to those with macular degeneration

...compound to a broken potassium channel, which is a valve found in nerve cells. When attached, one end of the compound sticks in the channel pore and blocks it like a drain plug. When hit with UV light, the molecule kinks and pulls the plug, allowing ions to flow through the channel and activate the nerve c...

Minorities, uninsured less likely to receive care at high-volume hospitals

...ip fracture repair, lung cancer resection, cardiac valve replacement, coronary angioplasty, pancreatic cancer resection, and total knee replacement. According to this database, a total of 719,608 patients received 1 of the 10 operations. The researchers found that "in general, blacks, Asians, Hispanics, ...

Engineering the heart piece by piece

...at 1 Hertz. The growing of heart muscle, heart valve and blood vessel tissue in the lab also requires careful control of conditions such as temperature, oxygen and carbon dioxide levels, nutrients and pH level. This can then encourage the cells to begin producing the kinds of molecules needed to signal...

Ultrasound upgrade produces images that work like 3-D movies

... to ultrasound images in living animals of a heart valve and blood vessels and needle biopsies of the animals' brains and esophagi. The researchers have since recorded ultrasound images of a model human fetus that is traditionally used in the testing of fetal ultrasound imaging devices. (Watch the video...

Natural polyester makes new sutures stronger, safer

...uding stents, surgical meshes and possibly a heart valve scaffold, says Simon Williams, CEO of Tepha and a ...n a patient, which would spare children with heart valve defects from undergoing repeated surgeries. Tests of the device in animals have shown promise. "W...

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

...ienced improvements in both the size of the aortic valve and in the severity of heart failure. To evaluat...mal activity. With the CoreValve system, aortic valve replacement is performed by threading a special delivery catheter through the femoral artery in the ...