Practicing orthodontists\u27 use and perceived efficacy of self-ligating brackets

Introduction. The purpose of this study was to compare perceptions of efficacy and efficiency of Self-Ligating Brackets vs. conventional brackets between practicing Orthodontists and Orthodontic Residents. Methods. Cross-sectional survey research using a three-wave emailing of addresses from the current American Association of Orthodontists directory. The directors of all orthodontic residency programs in the US were asked to also distribute to all residents. The survey included five sections: (1) respondents\u27 experience, (2) factors that influence, (3) positive or negative factors, (4) the perceived efficiency/efficacy, and (5) demographics. A 39% response rate (N=707) was obtained. Results. Over half (51.8%) stated using self-ligation in their practice. Non-board certified orthodontist (57.1%) reported using self-ligation more often than board certified orthodontists at 46.2%. The two most common systems used were GAC Innovation-R (52.7%) and Damon (50.3%). Of the advantages cited, the most common was decreased chair time (64.3%). Most (71.7%) felt negatively about the price of self-ligating brackets, and increased difficulty finishing cases (62.4%). Due to low response rate from residents, no comparison could be made between orthodontists and orthodontic residents. Conclusion. While this project answered questions about use of self-ligating brackets, it is still uncertain the motivating factors of orthodontists of their use of self-ligation. Self-ligation has seen a growth in the number of products available, and the amount of doctors using this technology in the last two decades. While there are still an increasing number of practitioners that are using self-ligation, there are still many practitioners who choose conventional brackets over self-ligation

On the Nonexistence of Relevant Subsets in Location Models

1 online resource (PDF, 9 pages

Cluster-Impact Fusion and Effective Deuteron Temperature

Temperature and kinematic line broadening are the primary contributions to the width of the proton energy spectrum measured in cluster-impact fusion experiments. By ascertaining these two contributions, we have determined an effective temperature for the high-velocity deuteron component that is responsible for the measured fusion yield. The extracted effective temperature is substantially higher than conventional estimates., and implies that cluster-impact fusion is hot fusion on an atomic scale. The proton spectrum rules out contaminants in explaining the high yield.Comment: 11 pages, 2 figures. PACS numbers: 79.20.RF, 25.45.--z, 47.40.Nm, 52.50. L

Initial postmarketing experience with crotalidae polyvalent immune Fab for treatment of rattlesnake envenomation.

STUDY OBJECTIVE: We describe our postmarketing experience with patients receiving Crotalidae polyvalent immune Fab (CroFab; FabAV) antivenom for treatment of rattlesnake envenomation. METHODS: The charts of 28 patients admitted between March 1 and September 9, 2001, with rattlesnake envenomation and treated with FabAV were reviewed for demographic information, time until antivenom treatment, laboratory findings, evidence of hypersensitivity reaction, length of hospital stay, and readmission to the hospital. RESULTS: All patients had swelling, 20 patients had elevated prothrombin times (\u3e14 seconds), 12 patients had low fibrinogen levels (/dL), and 6 patients had thrombocytopenia (platelet count \u3c120,000/mm(3)) on presentation. The total dose of FabAV ranged from 10 to 47 vials per patient. Hypofibrinogenemia was resistant to FabAV in some patients. On follow-up, recurrence of coagulopathy was detected in 3 patients, and recurrence of thrombocytopenia was detected in 1 patient. Two patients demonstrated delayed-onset severe thrombocytopenia. Recurrence or delayed-onset toxicity might have been underestimated because of incomplete follow-up in some patients. No acute hypersensitivity reactions occurred. Two patients reported mild symptoms of possible serum sickness on follow-up. CONCLUSION: FabAV effectively controlled the effects of envenomation; however, initial control of coagulopathy was difficult to achieve in some cases, and recurrence or delayed-onset hematotoxicity was common. When initially managing hematotoxicity, a trend toward normalization of laboratory values might be a more reasonable end point for FabAV treatment than attainment of normal reference values in nonbleeding patients

Manipulating the motion of large neutral molecules

Large molecules have complex potential-energy surfaces with many local minima. They exhibit multiple stereo-isomers, even at very low temperatures. In this paper we discuss the different approaches for the manipulation of the motion of large and complex molecules, like amino acids or peptides, and the prospects of state- and conformer-selected, focused, and slow beams of such molecules for studying their molecular properties and for fundamental physics studies. Accepted for publication in Faraday Disc. 142 (2009), DOI: 10.1039/b820045aComment: 12 page

Guest—Host Cross-linked Polyimides for Integrated Optics

We report on the optical and electrical characterization of aromatic, fluorinated, fully imidized, organic soluble, thermally and photochemically, crosslinkable, guest-host polyimides for integrated optics. Refractive indices and optical losses were measured to evaluate the performance of these materials for passive applications. Materials were doped with two high temperature nonlinear optical chromophores, and poled during crosslinking to produce nonlinear optical materials. Measurements of electro-optic coefficient, macroscopic second order susceptibility, and conductivity were performed to assess these materials as potential candidates for active devices

Clinical Features of Reported Ethylene Glycol Exposures in the United States

BackgroundEthylene glycol is highly toxic and represents an important cause of poisonings worldwide. Toxicity can result in central nervous system dysfunction, cardiovascular compromise, elevated anion gap metabolic acidosis and acute kidney injury. Many states have passed laws requiring addition of the bittering agent, denatonium benzoate, to ethylene glycol solutions to reduce severity of exposures. The objectives of this study were to identify differences between unintentional and intentional exposures and to evaluate the utility of denatonium benzoate as a deterrent.Methods and FindingsUsing the National Poison Data System, we performed a retrospective analysis of reported cases of ethylene glycol exposures from January 2006 to December 2013. Outcome classification was summed for intentionality and used as a basis for comparison of effect groups. There were 45,097 cases of ethylene glycol exposures resulting in 154 deaths. Individuals more likely to experience major effects or death were older, male, and presented with more severe symptoms requiring higher levels of care. Latitude and season did not correlate with increased exposures; however, there were more exposures in rural areas. Denatonium benzoate use appeared to have no effect on exposure severity or number.ConclusionDeaths due to ethylene glycol exposure were uncommon; however, there were major clinical effects and more exposures in rural areas. Addition of denatonium benzoate was not associated with a reduction in exposures. Alternative means to deter ingestion are needed. These findings suggest the need to consider replacing ethylene glycol with alternative and less toxic agents