Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 10 de 10
Filter
Add more filters










Publication year range
1.
Circ Cardiovasc Imaging ; 17(4): e016435, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38626096

ABSTRACT

Heart valve replacement has steadily increased over the past decades due to improved surgical mortality, an aging population, and the increasing use of transcatheter valve technology. With these developments, prosthetic valve complications, including prosthetic valve endocarditis, are increasingly encountered. In this review, we aim to characterize the manifestations of prosthetic valve endocarditis using representative case studies from our institution to highlight the advances and contributions of modern multimodality imaging techniques.


Subject(s)
Endocarditis, Bacterial , Endocarditis , Heart Valve Prosthesis Implantation , Heart Valve Prosthesis , Prosthesis-Related Infections , Humans , Aged , Endocarditis, Bacterial/diagnostic imaging , Endocarditis, Bacterial/therapy , Heart Valve Prosthesis/adverse effects , Endocarditis/diagnostic imaging , Endocarditis/etiology , Heart Valve Prosthesis Implantation/adverse effects , Multimodal Imaging , Prosthesis-Related Infections/diagnostic imaging , Prosthesis-Related Infections/therapy
2.
Clean Technol Environ Policy ; 24(3): 931-948, 2022.
Article in English | MEDLINE | ID: mdl-34840551

ABSTRACT

Eco-innovations are innovations capable of helping to reduce the environmental impacts of production processes. In this sense, the adoption of models that assess comprehensively, in an integrated manner and in different perspectives, the general performance of these innovations allows managers to guide their decisions. The object of this research is the use of an eco-innovation in the production processes of cassava, where the waste generated is treated by biodigesters. These cassava processing industries are located in southern Brazil, Paraná State, comprising a multiple case study. A literature review was also carried out to propose a set of indicators capable of assessing the overall impact of this eco-innovation in eight lines of action: (1) environmental, (2) social, (3) economic, (4) human resource training, (5) institutional development, (6) introduction of innovation, (7) unwanted occurrences, and (8) characteristics of environmental management. To compile and process the data, the computerized model INOVA-tec System was used. The objective was to employ the INOVA-tec System model as an instrument for evaluating eco-innovative processes in leading companies in its segment, looking for evidence to expand its usability to other realities in the agro-industry. The results show that the technology scenario is favorable to its dissemination; however, the low performance of the indicators together makes it underutilized.

3.
Heliyon ; 6(4): e03777, 2020 Apr.
Article in English | MEDLINE | ID: mdl-32322737

ABSTRACT

Multiple Intelligence (MI) helps to evaluate the brain processes of individuals. Identifying the types of multiple intelligence can help teachers to understand their students better. Several studies have identified MI in school children; nevertheless, in Mexico, these studies have been scarce. Therefore, the objective of this study was to analyze the differences of MI between genders and the grades-in-school of Mexican elementary schoolchildren. In an effort to investigate the differences of MI in elementary school children in Mexico, we provided a self-administered questionnaire to 161 Mexican students. Overall, our findings showed that the students' mean averages in the eight categories of MI were similar in both genders; in fact, the only significant differences in gender were found in intrapersonal intelligence (males reporting higher intrapersonal differences than females). No other significant differences in MI were found, nor were there interaction effects between gender and the grade in school. In summary, these results give us an understanding that the different types of MI may not be that well implemented in elementary school children.

4.
Appl Spectrosc ; 73(6): 665-677, 2019 Jun.
Article in English | MEDLINE | ID: mdl-30990053

ABSTRACT

The use of nanomachining methods capable of reproducible construction of nano-arrayed devices have revolutionized the field of plasmonic sensing by the introduction of a diversity of rationally engineered designs. Significant strides have been made to fabricate plasmonic platforms with tailored interparticle gaps to improve their performance for surface-enhanced Raman scattering (SERS) applications. Over time, a dichotomy has emerged in the implementation of SERS for analytical applications, the construction of substrates, optimization of interparticle spacing as a means to optimize electromagnetic field enhancement at the localized surface plasmon level, and the substrate sensitivity over extended areas to achieve quantitative performance. This work assessed the enhancement factor of plasmonic Ag/SiO2/Si disc-on-pillar (DOP) arrays of variable pitch with its analytical performance for quantitative applications. Experimental data were compared with those from finite-difference time-domain (FDTD) simulations used in the optimization of the array dimensions. A self-assembled monolayer (SAM) of benzenethiol rendered highly reproducible signals (RSD ∼4-10%) and SERS substrate enhancement factor (SSEF) values in the orders of 106-108 for all pitches. Spectra corresponding to rhodamine 6G (R6G) and 4-aminobenzoic acid demonstrated the advantages of using the more densely packed DOP arrays with a 160 nm pitch (gap = 40 nm) for quantitation in spite of the strongest SSEF was attained for a pitch of 520 nm corresponding to a 400 nm gap.

5.
J Back Musculoskelet Rehabil ; 31(4): 637-643, 2018.
Article in English | MEDLINE | ID: mdl-29526837

ABSTRACT

BACKGROUND AND OBJECTIVE: The aim of this study was to evaluate the effects of a 10-week core and mobility training program on pain perception and low back disability score in professors, students and employees of a university. METHODS: Twenty-four individuals of a university who previously reported pain and low back disability were randomly assigned to an experimental group (EG; n= 8) that received 2 weekly sessions of 50 minutes of core and mobility training for 10 weeks; or to a control group (CG; n= 16). Both groups received a guideline to adopt ergonomic postures during work and activities of daily living. The visual analog pain scale (VAS) and the Roland-Morris questionnaire (RMQ) were applied pre- and post intervention. RESULTS: Significant reductions in the pain intensity perception (p= 0.014) and low back functional disability (p= 0.011) were noted in the EG pre- and post measures. However, no significant difference was observed in the CG. Thus, there was a significant difference between the EG and the CG in the post-intervention measures (p= 0.001). CONCLUSION: Core and mobility training and home-ergonomic instructions were effective to reduce the pain intensity perception and low back functional disability in the EG.


Subject(s)
Activities of Daily Living , Low Back Pain/physiopathology , Pain Perception/physiology , Physical Therapy Modalities , Adult , Female , Humans , Low Back Pain/rehabilitation , Male , Pain Measurement , Pilot Projects , Posture , Surveys and Questionnaires , Young Adult
6.
Appl Spectrosc ; 70(9): 1432-45, 2016 Sep.
Article in English | MEDLINE | ID: mdl-27566257

ABSTRACT

The fabrication of high-performance plasmonic nanomaterials for bio-sensing and trace chemical detection is a field of intense theoretical and experimental research. The use of metal-silicon nanopillar arrays as analytical sensors has been reported with reasonable results in recent years. The use of bio-inspired nanocomposite structures that follow the Fibonacci numerical architecture offers the opportunity to develop nanostructures with theoretically higher and more reproducible plasmonic fields over extended areas. The work presented here describes the nanofabrication process for a series of 40 µm × 40 µm bio-inspired arrays classified as asymmetric fractals (sunflower seeds and romanesco broccoli), bilaterally symmetric (acacia leaves and honeycombs), and radially symmetric (such as orchids and lily flowers) using electron beam lithography. In addition, analytical capabilities were evaluated using surface-enhanced Raman scattering (SERS). The substrate characterization and SERS performance of the developed substrates as the strategies to assess the design performance are presented and discussed.

7.
Appl Spectrosc ; 67(11): 1315-22, 2013 Nov.
Article in English | MEDLINE | ID: mdl-24160884

ABSTRACT

Advances in nanofabrication have allowed the production of new and more reproducible substrates for the Raman detection of trace antimicrobials in water. The superior substrate uniformity combined with the ability to control surface morphology represents a significant step forward in the design of substrates with improved enhancement factors and trace-detection capabilities. The work presented herein successfully combines electron-beam lithography (EBL) and reactive ion-etching (RIE) protocols for the construction, testing, and validation of plasmonic hybrid morphology nanoarrays for the detection of arsenic antimicrobials in water. The fabricated substrates consist of 2500 µm(2) Ag-coated silicon dioxide (SiO2)/Si pillar nanoarrays of alternating hexagonal and elliptical features. Control of simple fabrication parameters such as inter-particle spacing (gap) and its orientation relative to the laser polarization vector (parallel or orthogonal) result in over a tenfold improvement in the apparent Raman response under optimized conditions. At a 633 nm excitation frequency, the best substrate performance was observed on parallel-oriented features with a 200 nm gap, with over one order of magnitude increase in the apparent surface-enhanced Raman scattering (SERS) signal relative to standard silver-polydimethylsiloxane (Ag-PDMS) nanocomposites. Monitoring of the characteristic As-C stretching band at 594 cm(-1) allowed the detection of arsenic antimicrobials in water well within the parts per million range. Calculated surface-enhancement factors (SEF) for this substrate, employing 532, 785, and 633 nm excitation wavelengths, was within five, six, and seven orders of magnitude, respectively. The effect of substrate morphology and nanofabrication process on the Raman enhancement factor is presented.


Subject(s)
Anti-Infective Agents/analysis , Nanostructures/chemistry , Nanotechnology/instrumentation , Spectrum Analysis, Raman/instrumentation , Arsanilic Acid/analysis , Nanostructures/ultrastructure , Nanotechnology/methods , Reproducibility of Results , Silicon Dioxide/chemistry , Silver/chemistry , Spectrum Analysis, Raman/methods
8.
Appl Spectrosc ; 65(4): 423-8, 2011 Apr.
Article in English | MEDLINE | ID: mdl-21396190

ABSTRACT

Organoarsenic drugs such as roxarsone and 4-arsanilic acid are poultry feed additives widely used in US broilers to prevent coccidosis and to enhance growth and pigmentation. Despite their veterinary benefits there has been growing concern about their use because over 90% of these drugs are released intact into litter, which is often sold as a fertilizing supplement. The biochemical degradation of these antimicrobials in the litter matrix can release significant amounts of soluble As(III) and As(V) to the environment, representing a potential environmental risk. Silver/polydimethylsiloxane (Ag/PDMS) nanocomposites are a class of surfaceenhanced Raman scattering (SERS) substrates that have proven effective for the sensitive, reproducible, and field-adaptable detection of aromatic acids in water. The work presented herein uses for the first time Ag/PDMS nanocomposites as substrates for the detection and characterization of trace amounts of roxarsone, 4-arsanilic acid, and acetarsone in water. The results gathered in this study show that organoarsenic species are distributed into the PDMS surface where the arsonic acid binds onto the embedded silver nanoparticles, enhancing its characteristic 792 cm(-1) stretching band. The chemisorption of the drugs to the metal facilitates its detection and characterization in the parts per million to parts per billion range. An extensive analysis of the distinct spectroscopic features of each drug is presented with emphasis on the interactions of the arsonic acid, amino, and nitro groups with the metal surface. The benefits of SERS based methods for the study of arsenic drugs are also discussed.


Subject(s)
Anti-Bacterial Agents/analysis , Arsenicals/analysis , Dimethylpolysiloxanes/chemistry , Nanocomposites/chemistry , Spectrum Analysis, Raman/methods , Animal Feed , Anti-Bacterial Agents/chemistry , Arsanilic Acid/analysis , Arsanilic Acid/chemistry , Arsenicals/chemistry , Environmental Monitoring , Metal Nanoparticles/chemistry , Roxarsone/analysis , Roxarsone/chemistry , Silver/chemistry
9.
J Chromatogr A ; 1113(1-2): 148-61, 2006 Apr 28.
Article in English | MEDLINE | ID: mdl-16516901

ABSTRACT

The binary adsorption isotherms of the enantiomers of Tröger's base in the phase system made of Chiral Technologies ChiralPak AD [a silica-based packing coated with amylose tri(3,5-dimethyl carbamate)] as the chiral stationary phase (CSP) and 2-propanol as the mobile phase were measured by the perturbation method. The more retained enantiomer exhibits a S-shaped adsorption isotherm with a clear inflection point, the concentration of the less retained enantiomer having practically no competitive influence on this isotherm: In the entire range of concentrations studied, dq2/dC1 approximately 0. By contrast, the less retained enantiomer has a Langmuir adsorption isotherm when pure. At constant mobile phase concentrations, however, its equilibrium concentration in the adsorbed phase increases with increasing concentration of the more retained enantiomer and dq1/dC2 > 0. This cooperative adsorption behavior, opposed to the classical competitive behavior, is exceedingly rare but was clearly demonstrated in this case. Two adsorption isotherm equations that account for these physical observations were derived. They are based on the formation of an adsorbed multi-layer, as suggested by the isotherm data. The excellent agreement between the experimental overloaded elution profiles of binary mixtures and the profiles calculated with the equilibrium-dispersive model validates this binary isotherm model. The adsorption energies calculated by molecular mechanics (MM) and by molecular dynamics (MD) indicate that the chiral recognition arising from the different interactions between the functional groups of the CSP and the molecules of the Tröger's base enantiomers are mainly driven by their Van der Waals interactions. The MD data suggest that the interactions of the (-)-Tröger's base with the CSP are more favored by 8+/-(5) kJ/mol than those of (+)-Tröger's base. This difference seems to be a contributing factor to the increased retention of the - enantiomer on this chromatographic system. The modeling of the data also indicates that both enantiomers can form high stoichiometry complexes while binding onto the stationary phase, in agreement with the results of the equilibrium isotherm studies.


Subject(s)
2-Propanol/chemistry , Amylose/analogs & derivatives , Phenylcarbamates/chemistry , Silicon Dioxide/chemistry , Adsorption , Amylose/chemistry , Models, Molecular , Stereoisomerism , Thermodynamics
10.
Appl Spectrosc ; 57(11): 1346-52, 2003 Nov.
Article in English | MEDLINE | ID: mdl-14658147

ABSTRACT

Polymer-nano-metallic-particle composites have demonstrated technological potential due to their unique optical and electrical properties. Herein, we report on composites prepared via physical vapor deposition of silver metal onto pliable poly(dimethylsiloxane) (PDMS) polymer. Rapid Ag diffusion and nano-metallic-particle formation in a phase-separated surface layer of the PDMS creates unique sub-surface-based composites whose properties vary based on rate of deposition and average Ag thickness. Additionally, nanometallic-particle spacing can be altered with fair reproducibility and reversibility by physically manipulating the Ag-PDMS composite. The optical properties of the materials are studied by visible wavelength optical extinction spectrometry and surface-enhanced Raman scattering (SERS), including studies performed during physical manipulation. Direct current (DC) conductivity measurements were made during Ag deposition to study percolation conditions for the materials. Depth-profiling was performed by X-ray photoelectron spectrometry. Sample Raman spectral data collected with the composite as a SERS substrate are included. A practical technological characteristic of these composite materials arises from their potential to be molded into functional devices.


Subject(s)
Electric Conductivity , Manufactured Materials/analysis , Nanotechnology/instrumentation , Nanotubes/chemistry , Photometry/methods , Polymers/chemistry , Silver/chemistry , Spectrum Analysis, Raman/methods , Surface Plasmon Resonance/methods , Coated Materials, Biocompatible/analysis , Coated Materials, Biocompatible/chemistry , Elasticity , Materials Testing , Nanotechnology/methods , Nanotubes/analysis , Optics and Photonics , Photometry/instrumentation , Polymers/analysis , Surface Properties
SELECTION OF CITATIONS
SEARCH DETAIL
...