3,883 research outputs found
Low frequency noise due to magnetic inhomogeneities in submicron FeCoB/MgO/FeCoB magnetic tunnel junctions
We report on room temperature low frequency noise due to magnetic
inhomogeneities/domain walls (MI/DWs) in elliptic submicron FeCoB/MgO/FeCoB
magnetic tunnel junctions with an area between 0.0245 and 0.0675{\mu}m2. In the
smaller area junctions we found an unexpected random telegraph noise (RTN1),
deeply in the parallel state, possibly due to stray field induced MI/DWs in the
hard layer. The second noise source (RTN2) is observed in the antiparallel
state for the largest junctions. Strong asymmetry of RTN2 and of related
resistance steps with current indicate spin torque acting on the MI/DWs in the
soft layer at current densities below 5x10^5 A/cm2.Comment: 12 pages, 4 figure
EEMI - An Electronic Health Record for Pediatricians: Adoption Barriers, Services and Use in Mexico
The use of paper health records and handwritten prescriptions are prone to preset errors of misunderstanding instructions or interpretations that derive in affecting patientsâ health. Electronic Health Records (EHR) systems are useful tools that among other functions can assists physiciansâ tasks such as finding recommended medicines (and their contraindications) and dosage for a given diagnosis, filling prescriptions and support data sharing with other systems. By using an EHR many errors can be avoided. This paper presents EEMI (Expediente ElectrĂłnico MĂ©dico Infantil), a Children EHR focused on assisting pediatricians in their daily office practice. EEMI functionality keeps the relationships among diagnosis, treatment, and medications. EEMI also calculates dosages and automatically creates prescriptions which can be personalized by the physician. The system also validates patient allergies to avoid prescription of any pharmaceutical with alerts. EEMI was developed based on the experience of pediatricians in the Monterrey metropolitan area. This paper also presents the current use of EHRs in Mexico, the Mexican Norm (NOM-024-SSA3-2010), standards for the development of electronic medical records and its relationships with other standards for data exchange and data representation in the health area. This system is currently in production. It uses novel technologies such as cloud computing and software services
Environmentally friendly analysis of emerging contaminants by pressurized hot water extraction-stir bar sorptive extraction-derivatization and gas chromatography-mass spectrometry
This work describes the development, optimiza-
tion, and validation of a new method for the simultaneous
determination of a wide range of pharmaceuticals (beta-
blockers, lipid regulators
...
) and personal care products
(fragrances, UV filters, phthalates
...
) in both aqueous and
solid environmental matrices. Target compounds were
extracted from sediments using pressurized hot water ex-
traction followed by stir bar sorptive extraction. The first
stage was performed at 1,500 psi during three static extrac-
tion cycles of 5 min each after optimizing the extraction
temperature (50
â
150 °C) and addition of organic modifiers
(% methanol) to water, the extraction solvent. Next, aqueous
extracts and water samples were processed using polydime-
thylsiloxane bars. Several parameters were optimized for
this technique, including extraction and desorption time,
ionic strength, presence of organic modifiers, and pH. Fi-
nally, analytes were extracted from the bars by ultrasonic
irradiation using a reduced amount of solvent (0.2 mL) prior
to derivatization and gas chromatography
â
mass spectrome-
try analysis. The optimized protocol uses minimal amounts
of organic solvents (<10 mL/sample) and time (
â
8 h/sam-
ple) compared to previous ex
isting methodologies. Low
standard deviation (usually below 10 %) and limits of de-
tection (sub-ppb) vouch for the applicability of the method-
ology for the analysis of target compounds at trace levels.
Once developed, the method was applied to determin
Genetic consequences of selection cutting on sugar maple (Acer saccharum Marshall)
Selection cutting is a treatment that emulates tree-by-tree replacement for forests with uneven-age structures. It creates small openings in large areas and often generates a more homogenous forest structure (fewer large leaving trees and defective trees) that differs from old-growth forest. In this study, we evaluated whether this type of harvesting has an impact on genetic diversity of sugar maple (Acer saccharum Marshall). Genetic diversity among seedlings, saplings, and mature trees was compared between selection cut and old-growth forest stands in Québec, Canada. We found higher observed heterozygosity and a lower inbreeding coefficient in mature trees than in younger regeneration cohorts of both forest types. We detected a recent bottleneck in all stands undergoing selection cutting. Other genetic indices of diversity (allelic richness, observed and expected heterozygosity, and rare alleles) were similar between forest types. We concluded that the effect of selection cutting on the genetic diversity of sugar maple was recent and no evidence of genetic erosion was detectable in Québec stands after one harvest. However, the cumulative effect of recurring applications of selection cutting in bottlenecked stands could lead to fixation of deleterious alleles, and this highlights the need for adopting better forest management practices
Atmospheric pressure gas chromatography-time-of-flight-mass spectrometry (APGC-ToF-MS) for the determination of regulated and emerging contaminants in aqueous samples after stir bar sorptive extraction (SBSE)
This work presents the development, optimization and validation of a multi-residue method for the simultaneous determination of 102 contaminants, including fragrances, UV filters, repellents, endocrine disruptors, biocides, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and several types of pesticides in aqueous matrices. Water samples were processed using stir bar sorptive extraction (SBSE) after the optimization of several parameters: agitation time, ionic strength, presence of organic modifiers, pH, and volume of the derivatizing agent. Target compounds were extracted from the bars by liquid desorption (LD). Separation, identification and quantification of analytes were carried out by gas chromatography (GC) coupled to time-of-flight (ToF-MS) mass spectrometry. A new ionization source, atmospheric pressure gas chromatography (APGC), was tested. The optimized protocol showed acceptable recovery percentages (50â100%) and limits of detection below 1 ng Lâ1 for most of the compounds. Occurrence of 21 out of 102 analytes was confirmed in several environmental aquatic matrices, including seawater, sewage effluent, river water and groundwater. Non-target compounds such as organophosphorus flame retardants were also identified in real samples by accurate mass measurement of their molecular ions using GC-APGCâToF-MS. To the best of our knowledge, this is the first time that this technique has been applied for the analysis of contaminants in aquatic systems. By employing lower energy than the more widely used electron impact ionization (EI), AGPC provides significant advantages over EI for those substances very susceptible to high fragmentation (e.g., fragrances, pyrethroids)
Comparison of plaque prolapse in consecutive patients treated with Xience V and Taxus Liberte stents
The purpose of this article is to investigate the prevalence of plaque prolapse (PP) after Xience V and Taxus Liberte stent implantation. During the study period 2006-2007, 200 consecutive patients underwent coronary revascularization for de novo lesions and received an intravascular ultrasound (IVUS) post-stenting evaluation, (n = 124 patients with Taxus Liberte and n = 76 with Xience V) (227 stent segments). Cross-sectional and longitudinal 3D IVUS images were analyzed in a blind fashion, evaluating the prevalence of PP and calculating its depth and angle. The angulation degree of the coronary artery at the lesion site pre-stent implantation was also evaluated by angiography. The prevalence of PP was 23.9% in Xience V versus 38.1% in Taxus Liberte (P = 0.025). The depth and angle of PP were greater in Taxus Liberte stent than Xience V stent (0.4 ± 0.1 mm versus 0.5 ± 0.2 mm, P = 0.004; and 32.0 ± 8.9° versus 44.6 ± 27.6°, P = 0.044, respectively). The angulation degree of the coronary artery at the lesion site was higher in presence of plaque prolapse than in its absence (48.2 ± 29.3° vs. 38.2 ± 28.1°, P = 0.013). By multivariate analysis, stent type was independently associated with incidence of plaque prolapse. Xience V stent has less plaque prolapse than Taxus Liberte stent. Stent design may play a role in the prevalence of plaque prolapse
Morphology of coronary artery lesions assessed by virtual histology intravascular ultrasound tissue characterization and fractional flow reserve
Fractional flow reserve (FFR) is an index of the physiological significance of a coronary stenosis. Patients who have lesions with a FFR of >0.80, even optimally treated with medication, have however a MACE rate ranging from 8 to 21%. Coronary plaques at high risk of rupture and clinical events can be also identified by virt
American Association of Colleges of Pharmacy (AACP) Co-Curriculum Toolkit
The co-curriculum is intended to run parallel to the formal curriculum and support the development of studentsâ professional knowledge, skills, abilities, behaviors, and attitudes, including scientific foundation, knowledge application, and practice competencies. Additionally, the co-curriculum can also support proficiency in skills and achievement of competencies that are concurrently taught within the formal curriculum. ACPE evaluates the way programs assess studentsâ acquisition of knowledge and application of knowledge to practice within co-curricular experiences and especially how they advance the professional development of students within affective domain areas of learning
- âŠ