28 research outputs found
Enhancement of the magnetic anisotropy of nanometer-sized Co clusters: influence of the surface and of the inter-particle interactions
We study the magnetic properties of spherical Co clusters with diameters
between 0.8 nm and 5.4 nm (25 to 7500$ atoms) prepared by sequential sputtering
of Co and Al2O3. The particle size distribution has been determined from the
equilibrium susceptibility and magnetization data and it is compared to
previous structural characterizations. The distribution of activation energies
was independently obtained from a scaling plot of the ac susceptibility.
Combining these two distributions we have accurately determined the effective
anisotropy constant Keff. We find that Keff is enhanced with respect to the
bulk value and that it is dominated by a strong anisotropy induced at the
surface of the clusters. Interactions between the magnetic moments of adjacent
layers are shown to increase the effective activation energy barrier for the
reversal of the magnetic moments. Finally, this reversal is shown to proceed
classically down to the lowest temperature investigated (1.8 K).Comment: 13 figures submitted to Phys. Rev.
Recommended from our members
Cause of Death and Predictors of All-Cause Mortality in Anticoagulated Patients With Nonvalvular Atrial Fibrillation : Data From ROCKET AF
M. Kaste on työryhmän ROCKET AF Steering Comm jäsen.Background-Atrial fibrillation is associated with higher mortality. Identification of causes of death and contemporary risk factors for all-cause mortality may guide interventions. Methods and Results-In the Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET AF) study, patients with nonvalvular atrial fibrillation were randomized to rivaroxaban or dose-adjusted warfarin. Cox proportional hazards regression with backward elimination identified factors at randomization that were independently associated with all-cause mortality in the 14 171 participants in the intention-to-treat population. The median age was 73 years, and the mean CHADS(2) score was 3.5. Over 1.9 years of median follow-up, 1214 (8.6%) patients died. Kaplan-Meier mortality rates were 4.2% at 1 year and 8.9% at 2 years. The majority of classified deaths (1081) were cardiovascular (72%), whereas only 6% were nonhemorrhagic stroke or systemic embolism. No significant difference in all-cause mortality was observed between the rivaroxaban and warfarin arms (P=0.15). Heart failure (hazard ratio 1.51, 95% CI 1.33-1.70, P= 75 years (hazard ratio 1.69, 95% CI 1.51-1.90, P Conclusions-In a large population of patients anticoagulated for nonvalvular atrial fibrillation, approximate to 7 in 10 deaths were cardiovascular, whereasPeer reviewe
Recommended from our members
How patients experience endocrine therapy for breast cancer: an online survey of side effects, adherence, and medical team support.
PurposeMany patients with hormone receptor-positive (HR+) breast cancer do not adhere to endocrine therapy (ET), and treatment-related side effects are often discussed by participants in online breast cancer forums. Our aim was to survey this unique group of patients about their ET-related experiences.MethodsWe partnered with patients active in breast cancer social media communities to develop a survey assessing ET-related side effects and medical team communication. Patients with a history of HR+ breast cancer who had received a recommendation to take ET were eligible to participate in the anonymous, online survey.ResultsRespondents included 2353 women and 54 men. Aromatase inhibitors were the most commonly used medication. Side effects were reported by 91.2%, were more often experienced by women than men (p < 0.001), and were primarily related to medication type. Approximately one-third of respondents discontinued therapy early. While most felt supported by their medical team, 31.5% reported that their side effects were dismissed or minimized. Survey respondents most frequently reported that a healthy diet and exercise, yoga/acupuncture, and vitamins/supplements were helpful in managing ET-related side effects.ConclusionsET-related side effects are very common, and one-third discontinued treatment early. Lifestyle changes and complementary therapies can be important tools for side effect management. One-third of patients did not feel that their side effects were taken seriously.Implications for cancer survivorsThis is the largest survey of ET use by participants in online breast cancer communities. Further research is needed to identify strategies to improve treatment adherence and to better manage ET-related side effects
Recommended from our members
How patients experience endocrine therapy for breast cancer: an online survey of side effects, adherence, and medical team support.
PurposeMany patients with hormone receptor-positive (HR+) breast cancer do not adhere to endocrine therapy (ET), and treatment-related side effects are often discussed by participants in online breast cancer forums. Our aim was to survey this unique group of patients about their ET-related experiences.MethodsWe partnered with patients active in breast cancer social media communities to develop a survey assessing ET-related side effects and medical team communication. Patients with a history of HR+ breast cancer who had received a recommendation to take ET were eligible to participate in the anonymous, online survey.ResultsRespondents included 2353 women and 54 men. Aromatase inhibitors were the most commonly used medication. Side effects were reported by 91.2%, were more often experienced by women than men (p < 0.001), and were primarily related to medication type. Approximately one-third of respondents discontinued therapy early. While most felt supported by their medical team, 31.5% reported that their side effects were dismissed or minimized. Survey respondents most frequently reported that a healthy diet and exercise, yoga/acupuncture, and vitamins/supplements were helpful in managing ET-related side effects.ConclusionsET-related side effects are very common, and one-third discontinued treatment early. Lifestyle changes and complementary therapies can be important tools for side effect management. One-third of patients did not feel that their side effects were taken seriously.Implications for cancer survivorsThis is the largest survey of ET use by participants in online breast cancer communities. Further research is needed to identify strategies to improve treatment adherence and to better manage ET-related side effects
Recommended from our members
Phase II randomized trial of a non-steroidal mouth wash for prevention and treatment of stomatitis in women with hormone receptor positive breast cancer treated with everolimus.
BackgroundStomatitis is a frequent dose limiting toxicity of everolimus, an approved therapy for patients with metastatic breast cancer. No randomized trials of a prophylactic measure to prevent mucositis have been reported.MethodsWe conducted a phase II, open-label trial in which patients with metastatic breast cancer starting everolimus were randomized to best supportive care (BSC) versus prophylactic use of an oral mucoadhesive, non-steroid containing mouth wash. The primary endpoint was rate of any grade stomatitis as reported by the treating physicians. Secondary endpoints were severity of stomatitis according to the Oral Mucositis Assessment Scale (OMAS) and rates of everolimus dose reduction or discontinuation due to mucositis.ResultsOf 61 evaluable patients, 32 were randomized to and treated with oral mucoadhesive and 29 with BSC. Any grade stomatitis developed in 46.9% (15/32) of study arm and 65.5% (19/29) of BSC arm patients (p = 0.14). The difference between the two arms was significantly in favor of the mucoadhesive arm when mucositis was scored according to the OMAS with average score of 0.3 in study arm versus 0.5 in the control arm (p = 0.03). There were fewer dose adjustments or therapy discontinuations in the study arm compared with BSC (16% versus 31%, respectively) but the difference did not reach statistical significance.ConclusionHere we provide early evidence from the first randomized trial supporting the use of oral prophylactic mucoadhesive for everolimus-associated stomatitis. A trial comparing prophylactic oral mucoadhesive to steroid mouth wash may be warranted