10 research outputs found

    Thermal stability and nanostructure of CoCrPt longitudinal recording media

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    We report a systematic study of activation volumes and their correlation with physical grain sizes and thermal stability in CoCrPt media fabricated by magnetron sputtering. Different underlayers and CoCrPt layer thicknesses were used to provide a range of lateral grain sizes, MIδ (product of remanence MI and film thickness δ) values, and remanence coercivities. Two methods, namely the field-sweep-rate dependence of coercivity and measurements of magnetic viscosity and irreversible susceptibility, were used to determine the activation volumes and the results obtained from the two methods are in reasonable agreement. For CoCrPt layer thickness from 10 nm to 27 nm, the activation volumes of these films range from about 3x10-18 cm3 to 5X IO-18 cm 3, which indicate that these films are thermally stable. Furthermore, for most samples the activation volumes are close to the volumes of the physical CoCrPt grains. This suggests that the magnetic grains in these films switch almost independently. Films with physical grain sizes small enough to approach thermal instability are also discussed

    Thermal stability and nanostructure of CoCrPt longitudinal recording media

    Get PDF
    We report a systematic study of activation volumes and their correlation with physical grain sizes and thermal stability in CoCrPt media fabricated by magnetron sputtering. Different underlayers and CoCrPt layer thicknesses were used to provide a range of lateral grain sizes, MIδ (product of remanence MI and film thickness δ) values, and remanence coercivities. Two methods, namely the field-sweep-rate dependence of coercivity and measurements of magnetic viscosity and irreversible susceptibility, were used to determine the activation volumes and the results obtained from the two methods are in reasonable agreement. For CoCrPt layer thickness from 10 nm to 27 nm, the activation volumes of these films range from about 3x10-18 cm3 to 5X IO-18 cm 3, which indicate that these films are thermally stable. Furthermore, for most samples the activation volumes are close to the volumes of the physical CoCrPt grains. This suggests that the magnetic grains in these films switch almost independently. Films with physical grain sizes small enough to approach thermal instability are also discussed

    An Outline History of Conservation in Archaeology and Anthropology as Presented Through Its Publications

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    Comprehensive molecular characterization of human colon and rectal cancer

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    To characterize somatic alterations in colorectal carcinoma, we conducted a genome-scale analysis of 276 samples, analysing exome sequence, DNA copy number, promoter methylation and messenger RNA and microRNA expression. A subset of these samples (97) underwent low-depth-of-coverage whole-genome sequencing. In total, 16% of colorectal carcinomas were found to be hypermutated: three-quarters of these had the expected high microsatellite instability, usually with hypermethylation and MLH1 silencing, and one-quarter had somatic mismatch-repair gene and polymerase ε (POLE) mutations. Excluding the hypermutated cancers, colon and rectum cancers were found to have considerably similar patterns of genomic alteration. Twenty-four genes were significantly mutated, and in addition to the expected APC, TP53, SMAD4, PIK3CA and KRAS mutations, we found frequent mutations in ARID1A, SOX9 and FAM123B. Recurrent copy-number alterations include potentially drug-targetable amplifications of ERBB2 and newly discovered amplification of IGF2. Recurrent chromosomal translocations include the fusion of NAV2 and WNT pathway member TCF7L1. Integrative analyses suggest new markers for aggressive colorectal carcinoma and an important role for MYC-directed transcriptional activation and repression.National Institutes of Health (U.S.) (Grant U24CA143799)National Institutes of Health (U.S.) (Grant U24CA143835)National Institutes of Health (U.S.) (Grant U24CA143840)National Institutes of Health (U.S.) (Grant U24CA143843)National Institutes of Health (U.S.) (Grant U24CA143845)National Institutes of Health (U.S.) (Grant U24CA143848)National Institutes of Health (U.S.) (Grant U24CA143858)National Institutes of Health (U.S.) (Grant U24CA143866)National Institutes of Health (U.S.) (Grant U24CA143867)National Institutes of Health (U.S.) (Grant U24CA143882)National Institutes of Health (U.S.) (Grant U24CA143883)National Institutes of Health (U.S.) (Grant U24CA144025)National Institutes of Health (U.S.) (Grant U54HG003067)National Institutes of Health (U.S.) (Grant U54HG003079)National Institutes of Health (U.S.) (Grant U54HG003273

    Ofatumumab versus Teriflunomide in Multiple Sclerosis

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    BACKGROUND: Ofatumumab, a subcutaneous anti-CD20 monoclonal antibody, selectively depletes B cells. Teriflunomide, an oral inhibitor of pyrimidine synthesis, reduces T-cell and B-cell activation. The relative effects of these two drugs in patients with multiple sclerosis are not known. METHODS: In two double-blind, double-dummy, phase 3 trials, we randomly assigned patients with relapsing multiple sclerosis to receive subcutaneous ofatumumab (20 mg every 4 weeks after 20-mg loading doses at days 1, 7, and 14) or oral teriflunomide (14 mg daily) for up to 30 months. The primary end point was the annualized relapse rate. Secondary end points included disability worsening confirmed at 3 months or 6 months, disability improvement confirmed at 6 months, the number of gadolinium-enhancing lesions per T1-weighted magnetic resonance imaging (MRI) scan, the annualized rate of new or enlarging lesions on T2-weighted MRI, serum neurofilament light chain levels at month 3, and change in brain volume. RESULTS: Overall, 946 patients were assigned to receive ofatumumab and 936 to receive teriflunomide; the median follow-up was 1.6 years. The annualized relapse rates in the ofatumumab and teriflunomide groups were 0.11 and 0.22, respectively, in trial 1 (difference, -0.11; 95% confidence interval [CI], -0.16 to -0.06; P<0.001) and 0.10 and 0.25 in trial 2 (difference, -0.15; 95% CI, -0.20 to -0.09; P<0.001). In the pooled trials, the percentage of patients with disability worsening confirmed at 3 months was 10.9% with ofatumumab and 15.0% with teriflunomide (hazard ratio, 0.66; P = 0.002); the percentage with disability worsening confirmed at 6 months was 8.1% and 12.0%, respectively (hazard ratio, 0.68; P = 0.01); and the percentage with disability improvement confirmed at 6 months was 11.0% and 8.1% (hazard ratio, 1.35; P = 0.09). The number of gadolinium-enhancing lesions per T1-weighted MRI scan, the annualized rate of lesions on T2-weighted MRI, and serum neurofilament light chain levels, but not the change in brain volume, were in the same direction as the primary end point. Injection-related reactions occurred in 20.2% in the ofatumumab group and in 15.0% in the teriflunomide group (placebo injections). Serious infections occurred in 2.5% and 1.8% of the patients in the respective groups. CONCLUSIONS: Among patients with multiple sclerosis, ofatumumab was associated with lower annualized relapse rates than teriflunomide. (Funded by Novartis; ASCLEPIOS I and II ClinicalTrials.gov numbers, NCT02792218 and NCT02792231.)

    Effects of pre-operative isolation on postoperative pulmonary complications after elective surgery: an international prospective cohort study

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    Delayed colorectal cancer care during covid-19 pandemic (decor-19). Global perspective from an international survey

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    Background The widespread nature of coronavirus disease 2019 (COVID-19) has been unprecedented. We sought to analyze its global impact with a survey on colorectal cancer (CRC) care during the pandemic. Methods The impact of COVID-19 on preoperative assessment, elective surgery, and postoperative management of CRC patients was explored by a 35-item survey, which was distributed worldwide to members of surgical societies with an interest in CRC care. Respondents were divided into two comparator groups: 1) ‘delay’ group: CRC care affected by the pandemic; 2) ‘no delay’ group: unaltered CRC practice. Results A total of 1,051 respondents from 84 countries completed the survey. No substantial differences in demographics were found between the ‘delay’ (745, 70.9%) and ‘no delay’ (306, 29.1%) groups. Suspension of multidisciplinary team meetings, staff members quarantined or relocated to COVID-19 units, units fully dedicated to COVID-19 care, personal protective equipment not readily available were factors significantly associated to delays in endoscopy, radiology, surgery, histopathology and prolonged chemoradiation therapy-to-surgery intervals. In the ‘delay’ group, 48.9% of respondents reported a change in the initial surgical plan and 26.3% reported a shift from elective to urgent operations. Recovery of CRC care was associated with the status of the outbreak. Practicing in COVID-free units, no change in operative slots and staff members not relocated to COVID-19 units were statistically associated with unaltered CRC care in the ‘no delay’ group, while the geographical distribution was not. Conclusions Global changes in diagnostic and therapeutic CRC practices were evident. Changes were associated with differences in health-care delivery systems, hospital’s preparedness, resources availability, and local COVID-19 prevalence rather than geographical factors. Strategic planning is required to optimize CRC care
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