Allery Treatment News

News From The American Chemical Society, May 14, 2008

March 16, 2017

New-generation artificial cornea could restore vision for millions worldwide

An improved artificial cornea, which could restore the vision of more than 10 million people worldwide who are blind due to diseased corneas, finally is moving toward reality, scientists in California conclude in a new analysis of research on the topic. Their study is scheduled for the June 6 issue of ACS' Biotechnology Progress, a bi-monthly journal.

Curtis Frank, Christopher Ta, David Myung, and Jennifer Cochran point out that disease or injury to the cornea - the clear tissue covering the front of the eye - is the second leading cause of blindness worldwide. Although treated in developed countries with transplants from donors, cornea transplants are unavailable in many parts of the world due to shortages of donors or to cultural or religious barriers. The growing popularity of laser eye surgery also is reducing availability of corneas by making them unacceptable for donation, the researchers add.

The report describes new materials that already have made limited-use artificial corneas available, partially fulfilling a medical dream that dates to 1771. More advanced materials, including polymer hydrogels similar to those used to make soft contact lenses, promise to so closely imitate human donor corneas that "these devices could eliminate the need for donor corneas altogether," the article notes. - MTS

ARTICLE: "Development of Hydrogel-Based Keratoprostheses: A Materials Perspective"

CONTACT:
Curtis W. Frank, Ph.D.
Stanford University
Stanford, California 94305

First evidence that bacteria get "touchy-feely" about dangerous biofilms

Researchers in Massachusetts report for the first time that bacteria use a sense of touch in deciding where to form biofilms. Those colonies of microbes grow on medical implants and other devices and play a key role in the multi-billion-dollar-per-year problem of antibiotic resistant infections. The finding could lead to safer implant materials for fighting biofilms, which are linked to thousands of deaths each year, the scientists say. It also can be used to develop materials capable of sustaining cultures of important, beneficial bacteria. Their study is scheduled for the June 9 issue of ACS' Biomacromolecules, a bi-monthly journal.

In the new report, Krystyn J. Van Vliet and colleagues note that past research focused on killing microbes that already have formed biofilms, or impregnating surfaces with antimicrobial compounds. Scientists knew about certain surface conditions that affected biofilm formation, though many results were in conflict, and the effect of mechanical stiffness of those surfaces had not been considered previously.

The researchers studied the effects of different polymer materials on the adhesion of Staphylococcus epidermidis, the most common bacterial source of hospital-based infections, and on E. coli. In laboratory tests, they found that the bacteria adhered preferentially to the stiffer polymers, as compared to other polymers. Altering the stiffness of the polymers used in implants could lead to "smarter" materials for fighting or sustaining biofilm formation, they conclude. - MTS

ARTICLE: "Substrata Mechanical Stiffness Can Regulate Adhesion of Viable Bacteria"

CONTACT:
Krystyn J. Van Vliet, Ph.D.
Massachusetts Institute of Technology
Cambridge, Massachusetts 02139

Rice grown in United States contains less-dangerous form of arsenic

Rice grown in the United States may be safer than varieties from Asia and Europe, according to a new global study of the grain that feeds over half of humanity. The study evaluated levels of arsenic, which can be toxic at high levels, in rice worldwide. The two-part report is scheduled for the May 15 issue of ACS' Environmental Science & Technology, a semi-monthly journal.

Yamily J. Zavala and colleagues point out that rice is a potentially important source of human exposure to arsenic, especially in populations with rice-based diets. Arsenic in rice is of special concern because it accumulates in much higher concentrations in rice than other staple grain crops. The researchers discovered that arsenic contamination of irrigation water was more important than soil contamination in increasing arsenic levels in rice.

Using global arsenic data, the researchers classified rice into two types, where the predominant arsenic forms were either organic or the more toxic inorganic forms. They found that rice from the United States largely contains organic arsenic, which is less easily absorbed into the body and excreted more rapidly than inorganic arsenic. Rice contaminated with inorganic arsenic prevails in Asia and Europe. The study suggests that breeding new rice varieties that convert inorganic arsenic to organic arsenic would be an "important risk reduction strategy, especially for countries like Bangladesh and India with arsenic contaminated environments and high rice consumption rates." - AD

ARTICLE:

"Arsenic in Rice: I. Estimating Normal Levels of Total Arsenic in Rice Grain"

"Arsenic in Rice: II. Arsenic Speciation in USA Grain and Implications for Human Health"

CONTACT:
Yamily J. Zavala, Ph.D.
Cornell University
Ithaca, NY 14853

A simple, low-cost carbon filter removes 90% of carbon dioxide from smokestack gases

Researchers in Wyoming report development of a low-cost carbon filter that can remove 90 percent of carbon dioxide gas from the smokestacks of electric power plants that burn coal and other fossil fuels. Their study is scheduled for the May 21 issue of ACS' monthly journal, Industrial & Engineering Chemistry Research.

Maciej Radosz and colleagues at Wyoming's Soft Materials Laboratory cite the pressing need for simple, inexpensive new technologies to remove carbon dioxide from smokestack gases. Coal-burning electric power plants are major sources of the greenhouse gas, and control measures may be required in the future.

The study describes a new carbon dioxide-capture process, called a Carbon Filter Process, designed to meet the need. It uses a simple, low-cost filter filled with porous carbonaceous sorbent that works at low pressures. Modeling data and laboratory tests suggest that the device works better than existing technologies at a fraction of their cost. - MTS

ARTICLE: "Flue-Gas Carbon Capture on Carbonaceous Sorbents: Toward a Low-Cost Multifunctional Carbon Filter for 'Green' Energy Producers"

CONTACT:
Maciej Radosz, Ph.D.
University of Wyoming
Laramie, Wyoming 82071

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The American Chemical Society - the world's largest scientific society - is a nonprofit organization chartered by the U.S. Congress and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.

Source: Mike Woods
American Chemical Society