Patients with intermediate or advanced AMD in at least one eye show a low adherence rate to the AREDS recommendations for vitamin supplementation.

No abstract

Point-of-use filters containing granular activated carbon (GAC) are an effective method for removing certain chemicals from water, but their ability to remove bacteria and viruses has been relatively untested. Collision efficiencies (␣) were determined using clean-bed filtration theory for two bacteria (Raoutella terrigena 33257 and Escherichia coli 25922), a bacteriophage (MS2), and latex microspheres for four GAC samples. These GAC samples had particle size distributions that were bimodal, but only a single particle diameter can be used in the filtration equation. Therefore, consistent with previous reports, we used a particle diameter based on the smallest diameter of the particles (derived from the projected areas of 10% of the smallest particles). The bacterial collision efficiencies calculated using the filtration model were high (0.8 < ␣ < 4.9), indicating that GAC was an effective capture material. Collision efficiencies greater than unity reflect an underestimation of the collision frequency, likely as a result of particle roughness and wide GAC size distributions. The collision efficiencies for microspheres (0.7 < ␣ < 3.5) were similar to those obtained for bacteria, suggesting that the microspheres were a reasonable surrogate for the bacteria. The bacteriophage collision efficiencies ranged from >0.2 to <0.4. The predicted levels of removal for 1-cm-thick carbon beds ranged from 0.8 to 3 log for the bacteria and from 0.3 to 1.0 log for the phage. These tests demonstrated that GAC can be an effective material for removal of bacteria and phage and that GAC particle size is a more important factor than relative stickiness for effective particle removal.Microbial contamination of drinking water is a major health problem in many areas around the world (8, 9). Because conventional water treatment technologies are often not available in places with the greatest water contamination problems, the World Health Organization has proposed that point-of-use (POU) water treatment devices are the most efficient solution to the problem (33). Many POU devices rely on adsorption onto granular activated carbon (GAC) as a mechanism for removal of contaminants. In order for POU water treatment to be successful, the GAC must be effective in removing both chemical and microbial contaminants from the water. While GAC is widely known to be effective for decolorization, dechlorination, and chemical removal (14, 15, 17, 31), the efficiency of this material for removal of bacteria and viruses is relatively unknown.The methods used to characterize the relative adhesion of bacteria and viruses to GAC range from batch adsorption tests to column tests. Batch adsorption tests have confirmed that microorganisms adsorb exclusively to the exterior surface of GAC due to pore size exclusion (24, 25, 27), but they do not provide information that is sufficient to predict removal rates in columns. Mass transfer models can be used to characterize chemical removal with GAC in packed beds, but they do not provide detailed information concerning ...

Approximately half of refractive surgeons said they consider HIV-positive persons acceptable candidates for elective refractive surgery; a much lower proportion considered patients with AIDS acceptable candidates. The majority of the surgeons recommended additional precautions when performing refractive surgery on patients with HIV or AIDS.