Use of electron beam lithography to selectively decompose metalorganics into patterned thin‐film superconductors

Fine line superconductors, approximately 5 μm in width and 260 nm thick, were formed from Y‐Ba‐Cu on 〈100〉SrTiO3 by the combined methods of metalorganic deposition and selective area electron beam exposure. The lines were written in metal neodecanoates using an electron beam having a spot size of 0.25 μm and an energy of 25 kV. The dosage of the exposure was 1200 μC/cm2. Unexposed areas were removed with a 30 s xylene wash. A 500 °C pyrolysis in air for 300 s followed by rapid thermal annealing in oxygen produced lines having superconducting onsets above 90 K and zero resistance at 69 K.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70966/2/APPLAB-53-6-526-1.pd

PROCESS FOR THE FORMATION OF WEAR- AND SCUFF-RESISTANT CARBON COATINGS

A process for forming an adherent diamond-like carbon coating on a workpiece of suitable material such as an aluminum alloy is disclosed. The workpiece is successively immersed in different plasma atmospheres and subjected to short duration, high voltage, negative electrical potential pulses or constant negative electrical potentials or the like so as to clean the surface of oxygen atoms, implant carbon atoms into the surface of the alloy to form carbide com pounds while codepositing a carbonaceous layer on the surface, bombard and remove the carbonaceous layer, and to thereafter deposit a generally amorphous hydrogen-containing carbon layer on the surface of the article

Quantum Size Effect transition in percolating nanocomposite films

We report on unique electronic properties in Fe-SiO2 nanocomposite thin films in the vicinity of the percolation threshold. The electronic transport is dominated by quantum corrections to the metallic conduction of the Infinite Cluster (IC). At low temperature, mesoscopic effects revealed on the conductivity, Hall effect experiments and low frequency electrical noise (random telegraph noise and 1/f noise) strongly support the existence of a temperature-induced Quantum Size Effect (QSE) transition in the metallic conduction path. Below a critical temperature related to the geometrical constriction sizes of the IC, the electronic conductivity is mainly governed by active tunnel conductance across barriers in the metallic network. The high 1/f noise level and the random telegraph noise are consistently explained by random potential modulation of the barriers transmittance due to local Coulomb charges. Our results provide evidence that a lowering of the temperature is somehow equivalent to a decrease of the metal fraction in the vicinity of the percolation limit.Comment: 21 pages, 8 figure

Management of Vascular Risk Factors in the Carotid Revascularization Endarterectomy Versus Stenting Trial (CREST)

BackgroundThe Carotid Revascularization Endarterectomy Versus Stenting Trial (CREST) is a multicenter randomized trial of stenting versus endarterectomy in patients with symptomatic and asymptomatic carotid disease. This study assesses management of vascular risk factors.Methods and ResultsManagement was provided by the patient's physician, with biannual monitoring results collected by the local site. Therapeutic targets were low‐density lipoprotein, cholesterol <100 mg/dL, systolic blood pressure <140 mm Hg, fasting blood glucose <126 mg/dL, and nonsmoking status. Optimal control was defined as achieving all 4 goals concurrently. Generalized estimating equations were used to compare risk factors at baseline with those observed in scheduled follow‐up visits for up to 48 months. In the analysis cohort of 2210, significant improvements in risk‐factor control were observed across risk factors for all follow‐up visits compared with baseline. At 48 months, achievement of the low‐density lipoprotein cholesterol goal improved from 59.1% to 73.6% (P<0.001), achievement of the systolic blood pressure goal improved from 51.6% to 65.1% (P<0.001), achievement of the glucose goal improved from 74.9% to 80.7% (P=0.0101), and nonsmoking improved from 74.4% to 80.9% (P<0.0001). The percentage with optimal risk‐factor control also improved significantly, from 16.7% to 36.2% (P<0.001), but nearly 2 of 3 study participants did not achieve optimal control during the study.ConclusionsSite‐based risk‐factor control improved significantly in the first 6 months and over the long term in CREST but was often suboptimal. Intensive medical management should be considered for future trials of carotid revascularization.Clinical Trial RegistrationURL: ClinicalTrials.gov. Unique identifier: NCT00004732

Meta-analysis of genome-wide association studies of asthma in ethnically diverse North American populations.

Asthma is a common disease with a complex risk architecture including both genetic and environmental factors. We performed a meta-analysis of North American genome-wide association studies of asthma in 5,416 individuals with asthma (cases) including individuals of European American, African American or African Caribbean, and Latino ancestry, with replication in an additional 12,649 individuals from the same ethnic groups. We identified five susceptibility loci. Four were at previously reported loci on 17q21, near IL1RL1, TSLP and IL33, but we report for the first time, to our knowledge, that these loci are associated with asthma risk in three ethnic groups. In addition, we identified a new asthma susceptibility locus at PYHIN1, with the association being specific to individuals of African descent (P = 3.9 × 10(-9)). These results suggest that some asthma susceptibility loci are robust to differences in ancestry when sufficiently large samples sizes are investigated, and that ancestry-specific associations also contribute to the complex genetic architecture of asthma