301 research outputs found

    Epitaxial growth of Co\u3csub\u3e3\u3c/sub\u3eO\u3csub\u3e3\u3c/sub\u3e on CoO(100)

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    Under mildly oxidizing ultrahigh vacuum conditions, it is possible to form on top of CoO(100) single crystal substrates, thin films that have higher oxygen content but that preserve the overall symmetry of the CoO(100) low-energy electron diffraction pattern. X-ray photoelectron spectroscopy (XPS) and high-resolution electron-energy-loss spectroscopy (HREELS) data indicate that the epitaxial film grown on CoO(100) at 625 K and 531027 Torr is Co3O3-like in both oxygen content and XP/HREEL spectroscopic characteristics. Both materials are closest packed in lattice oxygen, with the mismatch of bulk O2-–O2- distances of approximately 5%. However, the Co3O3 is only able to grow to a thickness of approximately 5 Å before the oxidation process halts. It is proposed that the orientation of Co3O3 that forms most readily on the CoO(100) surface does not present a thermodynamically stable orientation of the bulk Co3O3 substrate but is that which grows under the constraint of the best CoO(100)/Co3O3 epitaxial arrangement. While the mismatch in lattice parameters may in part be to blame for the limitation of higher oxide thickness, thicker oxide films have been grown under conditions with significantly larger mismatch

    High resolution electron energy loss spectroscopy of MnO(100) and oxidized MnO(100)

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    Single crystal MnO(100) substrates can be selectively oxidized to produce Mn2O3- and Mn3O4-like surfaces under mild oxidation/reduction conditions readily accessed under ultrahigh vacuum (UHV). MnO(100) yields a characteristic Mn 2p x-ray photoelectron spectroscopy (XPS) satellite structure and appropriate O/Mn concentrations from O 1s/Mn 2p XPS intensity ratios. Its high resolution electron energy loss (HREEL) spectrum shows a series of Fuchs–Kliewer multiple phonon excitations with a single loss energy of 70.9 meV, characteristic of the cubic manganese monoxide structure. However, the HREEL spectral (HREELS) background is high and the phonons are not as well resolved as those typically observed on comparable metal monoxides. Annealing the MnO(100) substrate at 625 K and 5×10-7 Torr O2 slowly forms Mn2O3, as indicated by O 1s and Mn 2p XPS, and does so without significantly altering the symmetry of the MnO(100) low energy electron diffraction pattern. The MnO(100)-Mn2O3 surface can be selectively reduced to Mn3O4-like composition by heating under UHV to 775 K and to MnO(100) at 1000 K. HREEL spectra for the UHV annealed surfaces are well-resolved, and for the MnO(100)-Mn3O4 substrate a second fundamental phonon loss is observed at 55.6 meV as a result of the lower symmetry of the Mn3O4 spinel structure. The UHV-annealed MnO(100) surface appears to be more highly ordered since its HREELS phonon loss peaks are better resolved. It is also somewhat reduced, however, resulting in a less intense phonon spectrum with a fundamental loss energy of only 65.1 meV

    High resolution electron energy loss spectroscopy of MnO(100) and oxidized MnO(100)

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    Single crystal MnO(100) substrates can be selectively oxidized to produce Mn2O3- and Mn3O4-like surfaces under mild oxidation/reduction conditions readily accessed under ultrahigh vacuum (UHV). MnO(100) yields a characteristic Mn 2p x-ray photoelectron spectroscopy (XPS) satellite structure and appropriate O/Mn concentrations from O 1s/Mn 2p XPS intensity ratios. Its high resolution electron energy loss (HREEL) spectrum shows a series of Fuchs–Kliewer multiple phonon excitations with a single loss energy of 70.9 meV, characteristic of the cubic manganese monoxide structure. However, the HREEL spectral (HREELS) background is high and the phonons are not as well resolved as those typically observed on comparable metal monoxides. Annealing the MnO(100) substrate at 625 K and 5×10-7 Torr O2 slowly forms Mn2O3, as indicated by O 1s and Mn 2p XPS, and does so without significantly altering the symmetry of the MnO(100) low energy electron diffraction pattern. The MnO(100)-Mn2O3 surface can be selectively reduced to Mn3O4-like composition by heating under UHV to 775 K and to MnO(100) at 1000 K. HREEL spectra for the UHV annealed surfaces are well-resolved, and for the MnO(100)-Mn3O4 substrate a second fundamental phonon loss is observed at 55.6 meV as a result of the lower symmetry of the Mn3O4 spinel structure. The UHV-annealed MnO(100) surface appears to be more highly ordered since its HREELS phonon loss peaks are better resolved. It is also somewhat reduced, however, resulting in a less intense phonon spectrum with a fundamental loss energy of only 65.1 meV

    Haloperidol and Ziprasidone for Treatment of Delirium in Critical Illness

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    BACKGROUND: There are conflicting data on the effects of antipsychotic medications on delirium in patients in the intensive care unit (ICU). METHODS: In a randomized, double-blind, placebo-controlled trial, we assigned patients with acute respiratory failure or shock and hypoactive or hyperactive delirium to receive intravenous boluses of haloperidol (maximum dose, 20 mg daily), ziprasidone (maximum dose, 40 mg daily), or placebo. The volume and dose of a trial drug or placebo was halved or doubled at 12-hour intervals on the basis of the presence or absence of delirium, as detected with the use of the Confusion Assessment Method for the ICU, and of side effects of the intervention. The primary end point was the number of days alive without delirium or coma during the 14-day intervention period. Secondary end points included 30-day and 90-day survival, time to freedom from mechanical ventilation, and time to ICU and hospital discharge. Safety end points included extrapyramidal symptoms and excessive sedation. RESULTS: Written informed consent was obtained from 1183 patients or their authorized representatives. Delirium developed in 566 patients (48%), of whom 89% had hypoactive delirium and 11% had hyperactive delirium. Of the 566 patients, 184 were randomly assigned to receive placebo, 192 to receive haloperidol, and 190 to receive ziprasidone. The median duration of exposure to a trial drug or placebo was 4 days (interquartile range, 3 to 7). The median number of days alive without delirium or coma was 8.5 (95% confidence interval [CI], 5.6 to 9.9) in the placebo group, 7.9 (95% CI, 4.4 to 9.6) in the haloperidol group, and 8.7 (95% CI, 5.9 to 10.0) in the ziprasidone group (P=0.26 for overall effect across trial groups). The use of haloperidol or ziprasidone, as compared with placebo, had no significant effect on the primary end point (odds ratios, 0.88 [95% CI, 0.64 to 1.21] and 1.04 [95% CI, 0.73 to 1.48], respectively). There were no significant between-group differences with respect to the secondary end points or the frequency of extrapyramidal symptoms. CONCLUSIONS: The use of haloperidol or ziprasidone, as compared with placebo, in patients with acute respiratory failure or shock and hypoactive or hyperactive delirium in the ICU did not significantly alter the duration of delirium. (Funded by the National Institutes of Health and the VA Geriatric Research Education and Clinical Center; MIND-USA ClinicalTrials.gov number, NCT01211522 .)

    Identification of a Robust Methylation Classifier for Cutaneous Melanoma Diagnosis

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    Early diagnosis improves melanoma survival, yet the histopathological diagnosis of cutaneous primary melanoma can be challenging, even for expert dermatopathologists. Analysis of epigenetic alterations, such as DNA methylation, that occur in melanoma can aid in its early diagnosis. Using a genome-wide methylation screening, we assessed CpG methylation in a diverse set of 89 primary invasive melanomas, 73 nevi, and 41 melanocytic proliferations of uncertain malignant potential, classified based on interobserver review by dermatopathologists. Melanomas and nevi were split into training and validation sets. Predictive modeling in the training set using ElasticNet identified a 40-CpG classifier distinguishing 60 melanomas from 48 nevi. High diagnostic accuracy (area under the receiver operator characteristic curve = 0.996, sensitivity = 96.6%, and specificity = 100.0%)was independently confirmed in the validation set (29 melanomas, 25 nevi)and other published sample sets. The 40-CpG melanoma classifier included homeobox transcription factors and genes with roles in stem cell pluripotency or the nervous system. Application of the 40-CpG melanoma classifier to the diagnostically uncertain samples assigned melanoma or nevus status, potentially offering a diagnostic tool to assist dermatopathologists. In summary, the robust, accurate 40-CpG melanoma classifier offers a promising assay for improving primary melanoma diagnosis

    Density Matrix Renormalisation Group Approach to the Massive Schwinger Model

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    The massive Schwinger model is studied, using a density matrix renormalisation group approach to the staggered lattice Hamiltonian version of the model. Lattice sizes up to 256 sites are calculated, and the estimates in the continuum limit are almost two orders of magnitude more accurate than previous calculations. Coleman's picture of `half-asymptotic' particles at background field theta = pi is confirmed. The predicted phase transition at finite fermion mass (m/g) is accurately located, and demonstrated to belong in the 2D Ising universality class.Comment: 38 pages, 18 figures, submitted to PR

    Psychiatric disorders among older prisoners: a systematic review and comparison study against older people in the community

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    Objectives: Despite emerging evidence that older prisoners experience poor mental health, literature in this area is still limited. In the present systematic review and meta-analysis, we report on the prevalence of psychiatric disorders among older prisoners and compare our findings against community studies on older people. Methods: We searched on Assia, PsycInfo, MedLine, Embase, Web of Science, Google and Gov.uk. We carried out bias assessments, rated studies for quality and ran a heterogeneity test. We meta-analysed prevalence rates of psychiatric disorders through an aggregate weighted mean and calculated Relative Risk and statistical significance against community studies. Sensitivity analyses were further performed. Results: We reviewed nine studies and obtained the following prevalence: “Any psychiatric disorder” 38.4%, depression 28.3%, schizophrenia/psychoses 5.5%, bipolar disorder 4.5%, dementia 3.3%, cognitive impairment 11.8%, personality disorder 22.9%, alcohol abuse 15.9%, anxiety disorders 14.2%, PTSD 6.2%. Older prisoners were found to have higher RR for every single psychiatric disorder against older people in the community, with the sole exception of alcohol abuse (RR=1) and dementia (RR=.75). The prevalence rates were statistically significantly higher (p<.05) among the prisoners for “Any psychiatric disorder”, depression and personality disorder. Overall, the sensitivity analyses confirmed our original results. Conclusion: Our findings point at a high prevalence of every single psychiatric disorder among older prisoners, who also experience rates of dementia and alcohol abuse comparable to those reported in the community. Our results have relevant implications for policy and practice in this area. Further research is crucial to confirm findings from this study

    Measurement of the Bs0→J/ψKS0B_s^0\to J/\psi K_S^0 branching fraction

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    The Bs0→J/ψKS0B_s^0\to J/\psi K_S^0 branching fraction is measured in a data sample corresponding to 0.41fb−1fb^{-1} of integrated luminosity collected with the LHCb detector at the LHC. This channel is sensitive to the penguin contributions affecting the sin2ÎČ\beta measurement from B0→J/ψKS0B^0\to J/\psi K_S^0 The time-integrated branching fraction is measured to be BF(Bs0→J/ψKS0)=(1.83±0.28)×10−5BF(B_s^0\to J/\psi K_S^0)=(1.83\pm0.28)\times10^{-5}. This is the most precise measurement to date

    Model-independent search for CP violation in D0→K−K+π−π+ and D0→π−π+π+π− decays

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    A search for CP violation in the phase-space structures of D0 and View the MathML source decays to the final states K−K+π−π+ and π−π+π+π− is presented. The search is carried out with a data set corresponding to an integrated luminosity of 1.0 fb−1 collected in 2011 by the LHCb experiment in pp collisions at a centre-of-mass energy of 7 TeV. For the K−K+π−π+ final state, the four-body phase space is divided into 32 bins, each bin with approximately 1800 decays. The p-value under the hypothesis of no CP violation is 9.1%, and in no bin is a CP asymmetry greater than 6.5% observed. The phase space of the π−π+π+π− final state is partitioned into 128 bins, each bin with approximately 2500 decays. The p-value under the hypothesis of no CP violation is 41%, and in no bin is a CP asymmetry greater than 5.5% observed. All results are consistent with the hypothesis of no CP violation at the current sensitivity

    Measurement of the CP-violating phase \phi s in Bs->J/\psi\pi+\pi- decays

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    Measurement of the mixing-induced CP-violating phase phi_s in Bs decays is of prime importance in probing new physics. Here 7421 +/- 105 signal events from the dominantly CP-odd final state J/\psi pi+ pi- are selected in 1/fb of pp collision data collected at sqrt{s} = 7 TeV with the LHCb detector. A time-dependent fit to the data yields a value of phi_s=-0.019^{+0.173+0.004}_{-0.174-0.003} rad, consistent with the Standard Model expectation. No evidence of direct CP violation is found.Comment: 15 pages, 10 figures; minor revisions on May 23, 201
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