Localized edge vibrations and edge reconstruction by joule heating in graphene nanostructures.

Control of the edge topology of graphene nanostructures is critical to graphene-based electronics. A means of producing atomically smooth zigzag edges using electronic current has recently been demonstrated in experiments [Jia, Science 323, 1701 (2009)10.1126/science.1166862]. We develop a microscopic theory for current-induced edge reconstruction using density functional theory. Our calculations provide evidence for localized vibrations at edge interfaces involving unpassivated armchair edges. We demonstrate that these vibrations couple to the current, estimate their excitation by Joule heating, and argue that they are the likely cause of the reconstructions observed in the experiments.

Placebo-controlled, double-blind study of the efficacy and safety of triamcinolone acetonide aerosol nasal inhaler in pediatric patients with seasonal allergic rhinitis.

Triamcinolone acetonide (TAA) aerosol nasal inhaler has been shown to effectively relieve the symptoms of seasonal allergic rhinitis in adults and adolescents. We conducted a study to evaluate the efficacy and safety of once-daily administration of TAA aerosol nasal inhaler in pediatric patients aged 6 to 11 years with grass seasonal allergic rhinitis. This multicenter, randomized, double-blind, placebo-controlled, parallel-group study enrolled 116 children who were treated with either TAA aerosol nasal inhaler (220 micrograms/d) or placebo once daily for 2 weeks. Patients evaluated the severity of rhinitis symptoms (nasal stuffiness, discharge, sneezing, and itching) daily according to a four-point scale (0 = absent, 1 = mild, 2 = moderate, and 3 = severe). Patients' and physicians' global evaluations of overall treatment efficacy were assessed at the end of the 2-week treatment period. Patients treated with TAA aerosol nasal inhaler had significantly greater reductions in all nasal symptom scores overall and in virtually all symptoms at the end of week 1 and week 2 compared with those in the placebo group. Both patients' and physicians' global evaluations of efficacy favored TAA aerosol nasal inhaler over placebo. This study demonstrated that once-daily administration of 220 micrograms of TAA aerosol nasal inhaler was well tolerated and effectively reduced the symptoms of seasonal allergic rhinitis in pediatric patients.

Efficacy and safety of triamcinolone acetonide aqueous nasal spray in patients with seasonal allergic rhinitis.

BACKGROUND: In order to accommodate increasing patient preferences a new aqueous formulation of triamcinolone acetonide nasal spray was developed for the relief of symptoms associated with seasonal and perennial allergic rhinitis. OBJECTIVE: This multicenter, randomized, double-blind study was designed to compare the efficacy and safety of once-daily triamcinolone acetonide aqueous nasal spray (220 micrograms/day) with placebo in relieving the symptoms of seasonal allergic rhinitis due to ragweed. METHODS: One hundred forty patients received either a once daily 220-microgram dose of triamcinolone acetonide aqueous nasal spray or placebo for 2 weeks. Patients evaluated the severity of seasonal allergic rhinitis symptoms daily for 2 weeks according to a 4-point scale (0 = absent, 1 = mild, 2 = moderate, 3 = severe). Physician and patient global evaluations of overall treatment effectiveness were assessed at the end of the treatment period. RESULTS: Patients receiving triamcinolone acetonide aqueous nasal spray, 220 micrograms/day, had significantly (P < .05) greater improvements in all rhinitis symptoms at weeks 1 and 2 and overall for the 2-week treatment period compared with the placebo group. A significant (P = .006) improvement in the nasal index occurred as early as 12 hours after the first dose of triamcinolone acetonide aqueous nasal spray. Both patients and physicians reported a greater overall improvement in symptoms for the triamcinolone acetonide aqueous nasal spray group. There were no differences between the two treatment groups in the incidence of adverse events. CONCLUSIONS: This study confirmed that a 220-microgram dose of triamcinolone acetonide aqueous nasal spray, administered once daily for 2 weeks, is well tolerated and reduces effectively the severity of symptoms of seasonal allergic rhinitis due to ragweed.

A comparison of effects of triamcinolone acetonide aqueous nasal spray, oral prednisone, and placebo on adrenocortical function in male patients with allergic rhinitis.

BACKGROUND: One of the risks associated with the use of oral corticosteroids is suppression of adrenocortical function. Triamcinolone acetonide (TAA) aqueous nasal spray administered once daily (110 micrograms and 220 micrograms) has been shown to reduce allergic rhinitis symptoms. OBJECTIVE: This multicenter, placebo-controlled, double-blind study determined the effects of TAA aqueous nasal spray, placebo, and oral prednisone on adrenocortical function in patients with allergic rhinitis. METHODS: Sixty-four patients received TAA aqueous nasal spray (220 micrograms or 440 micrograms), oral prednisone (10 mg), or placebo once daily for 6 weeks. Adrenocortical function was assessed after cosyntropin stimulation for 6 hours before treatment and after 6 weeks of treatment. RESULTS: There was no statistically significant effect on adrenocortical function in patients who received either dose of TAA aqueous nasal spray compared with placebo. In contrast, prednisone produced statistically significant (p < 0.001) reductions in adrenocortical function compared with placebo; reductions occurred in both the mean 6-hour plasma cortisol levels and mean change in 6-hour plasma cortisol levels from pretreatment. CONCLUSION: This study demonstrated that, unlike oral prednisone, TAA aqueous nasal spray, in therapeutic doses, did not alter adrenocortical function and was comparable to treatment with placebo in its absence of measurable effects on adrenocortical function.

Long-term safety and efficacy of triamcinolone acetonide aqueous nasal spray for the treatment of perennial allergic rhinitis.

This 12-month, multicenter, open-label study to assess the long-term safety and efficacy of triamcinolone acetonide (TAA) aqueous nasal spray for perennial allergic rhinitis (PAR) symptom relief was a continuation of a 4-week, double-blind study. Patients who received TAA Aqueous (220 micrograms/day) during the 4-week, double-blind study continued with the same treatment for the open label study; those randomized to placebo during the 4-week, double-blind study received TAA Aqueous (220 micrograms/day) for the open-label study. Dose reduction to 110 micrograms/day was allowed if it was felt that symptom relief would be maintained. Safety was assessed by daily diary entries and clinical laboratory results. Long-term efficacy was assessed by visual analog scale (VAS). Of the 172 patients who began the open-label study, 94.2 percent completed 3 months of treatment, 83.6 percent completed 6 months, and 62 percent completed 12 months. PAR symptom relief improved progressively throughout the study. Adverse events were generally mild or moderate and consistent with long-term use and winter symptoms. The most common adverse events were pharyngitis (32 percent of patients), rhinitis (28.5 percent), headache (22.1 percent), and epistaxis (18 percent). Adverse events related to the local effects of the study medication were similar to those observed in long-term studies with TAA aerosol. The aqueous nasal spray formulation of triamcinolone acetonide was well tolerated and continued to relieve nasal symptoms with long-term use in adolescent and adult patients with PAR.