1,191 research outputs found
Electrodeposition in capillaries: bottom-up micro- and nanopatterning of functional materials on conductive substrates
A cost-effective and versatile methodology for bottom-up patterned growth of inorganic and metallic materials on the micro- and nanoscale is presented. Pulsed electrodeposition was employed to deposit arbitrary patterns of Ni, ZnO, and FeO(OH) of high quality, with lateral feature sizes down to 200–290 nm. The pattern was defined by an oxygen plasma-treated patterned PDMS mold in conformal contact with a conducting substrate and immersed in an electrolyte solution, so that the solid phases were deposited from the solution in the channels of the patterned mold. It is important that the distance between the entrance of the channels, and the location where deposition is needed, is kept limited. The as-formed patterns were characterized by high resolution scanning electron microscope, energy-dispersive X-ray analysis, atomic force microscopy, and X-ray diffraction
Patterning functional materials using channel diffused plasma-etched self-assembled monolayer templates
A simple and cost-effective methodology for large-area micrometer-scale patterning of a wide range of metallic and oxidic functional materials is presented. Self-assembled monolayers (SAM) of alkyl thiols on Au were micropatterned by channel-diffused oxygen plasma etching, a method in which selected areas of SAM were protected from plasma oxidation via a soft lithographic stamp. The patterned SAMs were used as templates for site-selective electrodeposition, electroless deposition and solution-phase deposition of functional materials such as ZnO, Ni, Ag thin films, and ZnO nanowires. The patterned SAMs and functional materials were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), atomic force microscopy (AFM), and tunneling AFM (TUNA).\u
Nanopatterning of functional materials by gas phase pattern deposition of self assembled molecular thin films in combination with electrodeposition
We present a general methodology to pattern functional materials on the nanometer scale using self-assembled molecular templates on conducting substrates. A soft lithographic gas phase edge patterning process using poly(dimethylsiloxane) molds was employed to form electrically isolating organosilane patterns of a few nanometer thickness and a line width that could be tuned by varying the time of deposition. Electrodeposition was employed to deposit patterns of Ni and ZnO on these prepatterned substrates. Deposition occurred only on patches of the substrate where no organosilane monolayer was present. The process is simple, inexpensive, and scalable to large areas. We achieved formation of metallic and oxide material patterns with a lateral resolution of 80 n
Color stability, Roughness, and Microhardness of Enamel and Composites Submitted to Staining/Bleaching Cycles
Objective: To compare the effect of two bleaching systems (bleaching gel and whitening strips) on the color change, roughness, and microhardness of enamel and two resin composites.
Material and methods: Two cavities were prepared on bovine enamel specimens (n = 16) and restored with two composites: a nano-hybrid [Herculite Ultra (HU)] and a micro-hybrid composite [TPH Spectra (TS)]. Baseline color (CIE L*a*b*), roughness (μm), and microhardness (kgf/mm2) were measured using a spectrophotometer, optical profilometer, and Vickers microhardness (VHN) tester, respectively. The specimens were stained with coffee for 14 days, and randomized into two bleaching groups: gel and strips (n = 8), then submitted to a 10-day bleaching/staining test. Color, roughness, and microhardness were re-measured. The outcomes were analyzed using two-way ANOVA and Fisher's-PLSD test (α = 0.05).
Results: Gel significantly improved the color (ΔE 4.9-8.3) and increased the roughness (Ra 0.04-0.08 μm) of all substrates (p < 0.0001) compared to strips. Enamel color was significantly improved (ΔE 5.4-8.3) compared to that of HU (ΔE 2.6-4.9) and TS (ΔE 2.0-4.9) with either gels or strips. TS roughness (0.03-0.08 μm) was significantly higher than that of enamel (0.01-0.05 μm) and HU (0.02-0.04 μm). Enamel had significantly reduced microhardness compared to HU (p = 0.0144).
Conclusion: Gels produced the greatest color improvement and roughness compared to strips. Enamel had significant color improvement but had the greatest decrease in microhardness.
Clinical significance: There was unacceptable color change between enamel and the composites after the combined cyclic effects of staining and bleaching
Comparing endovenous laser ablation, foam sclerotherapy, and conventional surgery for great saphenous varicose veins
BackgroundMany case series have been published on treatments of varicose veins, but comparative randomized controlled trials remain sparse.ObjectiveTo compare the anatomic success rate, frequency of major complications, and quality-of-life improvement of endovenous laser ablation (EVLA), ultrasound-guided foam sclerotherapy (UGFS), and conventional surgery (CS), after 1-year follow-up.MethodsA total of 240 consecutive patients with primary symptomatic great saphenous vein reflux were randomized to EVLA, UGFS, or CS, consisting of high ligation and short stripping. Primary outcome was anatomic success defined as obliteration or absence of the treated vein on ultrasound examination after 1 year. Secondary outcomes were complications, improvement of the “C” class of the CEAP classification, and improvement of disease-specific (Chronic Venous Insufficiency Quality-of-Life Questionnaire) and general (EuroQol 5) quality-of-life scores.ResultsMore than 80% of the study population was classified as C2 or C3 venous disease. After 1 year, the anatomic success rate was highest after EVLA (88.5%), followed by CS (88.2%) and UGFS (72.2%) (P < .001). The complication rate was low and comparable between treatment groups. All groups showed significant (P < .001) improvement of EuroQol 5 and Chronic Venous Insufficiency Quality-of-Life Questionnaire scores after therapy; 84.3% of all treated patients showed an improvement of the “C” of the CEAP classification.ConclusionsAfter 1-year follow-up, EVLA is as effective as CS and superior to UGFS according to occlusion on ultrasound duplex. Quality of life improves after treatment in all groups significantly
Nifedipine Suppresses Self-Injurious Behaviors in Animals
Self-injurious behavior is a common problem in many developmental disorders. The neurobiology of this behavior is not well understood, but the differing behavioral manifestations and associations with different disorders suggest that the underlying biological mechanisms are heterogeneous. The behavioral and biological heterogeneity is also evident in several animal models, where different manifestations can be provoked under different experimental conditions. Identifying commonalities among the different mechanisms is likely to be helpful in the design of treatments useful for the broadest populations of patients. The current studies reveal that nifedipine suppresses self-injurious behavior in 4 unrelated animal models: acute administration of high doses of ± BayK 8644 or methamphetamine in mice, dopamine agonist treatment in rats with lesions of dopamine pathways during early development and repeated administration of pemoline in rats. The effect of nifedipine does not appear to be due to nonspecific mechanisms, such as sedation, since other classes of behaviors are unaffected or exaggerated. These results suggest that nifedipine may target a common biological mechanism in the expression of self-injurious behavior, and they suggest it should be considered in the treatment or self-injury in humans
Atomic X-ray Spectroscopy of Accreting Black Holes
Current astrophysical research suggests that the most persistently luminous
objects in the Universe are powered by the flow of matter through accretion
disks onto black holes. Accretion disk systems are observed to emit copious
radiation across the electromagnetic spectrum, each energy band providing
access to rather distinct regimes of physical conditions and geometric scale.
X-ray emission probes the innermost regions of the accretion disk, where
relativistic effects prevail. While this has been known for decades, it also
has been acknowledged that inferring physical conditions in the relativistic
regime from the behavior of the X-ray continuum is problematic and not
satisfactorily constraining. With the discovery in the 1990s of iron X-ray
lines bearing signatures of relativistic distortion came the hope that such
emission would more firmly constrain models of disk accretion near black holes,
as well as provide observational criteria by which to test general relativity
in the strong field limit. Here we provide an introduction to this phenomenon.
While the presentation is intended to be primarily tutorial in nature, we aim
also to acquaint the reader with trends in current research. To achieve these
ends, we present the basic applications of general relativity that pertain to
X-ray spectroscopic observations of black hole accretion disk systems, focusing
on the Schwarzschild and Kerr solutions to the Einstein field equations. To
this we add treatments of the fundamental concepts associated with the
theoretical and modeling aspects of accretion disks, as well as relevant topics
from observational and theoretical X-ray spectroscopy.Comment: 63 pages, 21 figures, Einstein Centennial Review Article, Canadian
Journal of Physics, in pres
The EMSO Generic Instrument Module (EGIM): standardized and interoperable instrumentation for ocean observation
The oceans are a fundamental source for climate balance, sustainability of resources and life on Earth, therefore society has a strong and pressing interest in maintaining and, where possible, restoring the health of the marine ecosystems. Effective, integrated ocean observation is key to suggesting actions to reduce anthropogenic impact from coastal to deep-sea environments and address the main challenges of the 21st century, which are summarized in the UN Sustainable Development Goals and Blue Growth strategies. The European Multidisciplinary Seafloor and water column Observatory (EMSO), is a European Research Infrastructure Consortium (ERIC), with the aim of providing long-term observations via fixed-point ocean observatories in key environmental locations across European seas from the Arctic to the Black Sea. These may be supported by ship-based observations and autonomous systems such as gliders. In this paper, we present the EMSO Generic Instrument Module (EGIM), a deployment ready multi-sensor instrumentation module, designed to measure physical, biogeochemical, biological and ecosystem variables consistently, in a range of marine environments, over long periods of time. Here, we describe the system, features, configuration, operation and data management. We demonstrate, through a series of coastal and oceanic pilot experiments that the EGIM is a valuable standard ocean observation module, which can significantly improve the capacity of existing ocean observatories and provides the basis for new observatories. The diverse examples of use included the monitoring of fish activity response upon oceanographic variability, hydrothermal vent fluids and particle dispersion, passive acoustic monitoring of marine mammals and time series of environmental variation in the water column. With the EGIM available to all the EMSO Regional Facilities, EMSO will be reaching a milestone in standardization and interoperability, marking a key capability advancement in addressing issues of sustainability in resource and habitat management of the oceans.This work was funded by the project EMSODEV (Grant agreement No 676555) supported by DG Research and Innovation of the European Commission under the Research Infrastructures Programme of the H2020. EMSO-link EC project (Grant agreement No 731036) provided additional funding. Other projects which supported the work include Plan Estatal de Investigación Científica y Técnica y de Innovación 2017–2020, project BITER-LANDER PID2020- 114732RB-C32, iFADO (Innovation in the Framework of the Atlantic Deep Ocean, 2017–2021) EAPA_165/2016. The Spanish Government contributed through the “Severo Ochoa Centre Excellence” accreditation to ICM-CSIC (CEX2019-000928-S) and the Research Unit Tecnoterra (ICM-CSIC/UPC). UK colleagues were supported by Climate Linked Atlantic Sector Science (CLASS) project supported by NERC National Capability funding (NE/R015953/1).Peer ReviewedArticle signat per 33 autors/es: Nadine Lantéri; Henry A. Ruh; Andrew Gates; Enoc Martínez; Joaquin del Rio Fernandez; Jacopo Aguzzi; Mathilde Cannat; Eric Delory; Davide Embriaco; Robert Huber; Marjolaine Matabos;George Petihakis; Kieran Reilly; Jean-François Rolin; Mike van der Schaar; Michel André; Jérôme Blandin; Andrés Cianca; Marco Francescangeli; Oscar Garcia; Susan Hartman; Jean-Romain Lagadec; Julien Legrand; Paris Pagonis; Jaume Piera; Xabier Remirez; Daniel M. Toma; Giuditta Marinaro; Bertrand Moreau; Raul Santana; Hannah Wright; Juan José Dañobeitia; Paolo FavaliPostprint (published version
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