Spin echo MRI in the evaluation of hearts with a double outlet right ventricle: usefulness and limitations

The surgical approach to a double outlet right ventricle (DORV) is dependent on the spatial relationship of the semilunar valves, outflow tracts and ventricular septal defect (VSD). The purpose of the study was to assess the value of MRI for the evaluation of cardiovascular anatomy in patients before and after surgery for DORV. Spin echo MRI was performed in 12 patients with DORV (eight preoperative and four postoperative patients). Thin-section MRI was performed in three orthogonal planes and selected angulated views were obtained. Conventional imaging by color Doppler echocardiography and cine-angiocardiography and surgical findings, when present, served as the reference standards. The results found that the spatial relationship between semilunar valves and VSD was accurately assessed by MRI in eight out of eight preoperative patients. In the four postoperative cases MRI depicted the morphology of both outflow tracts and provided adequate information on their patency. Of the eight preoperative patients, five have undergone corrective surgery and the MRI findings were confirmed. MRI provided additional information to conventional imaging preoperatively in three cases in which the VSD opened into the outlet portion of the DORV, without there being a direct relation to a semilunar valve. In two preoperative cases in which the VSD was directly committed to the aorta, conventional imaging was conclusive. MRI was unable to depict aberrant chordae tendineae in four out of four cases. We conclude that MRI provides accurate additional anatomic information in patients with DORV, which is helpful in presurgical planning as well as during follow-up. Spin echo MRI does not visualize aberrant chordae tendineae.     

Microstructure characterization of titanium dioxide nanodispersions and thin films for dye-sensitized solar cell devices

This article reports on the microstructure characterization of titanium dioxide nanodispersions and thin films made thereof for dye-sensitized solar cell devices. Structure–property relationships have been investigated mainly using electron microscopy to assess how microstructure (crystalline structure, defects) and morphological (e.g. heterogeneities, inclusions, voids) features in the electron transport element of the solar cell device correlate with electrical performance, namely, short-circuit photocurrent density (J_sc). This work shows that for a nanodispersion synthesized in the laboratory different electrical performances are measurable depending on the thin film forming process, more specifically, heat-sintering at 450 °C or pressure-sintering at 500 bar. For the heat-sintered device J_sc is about 7.3 mA/cm² whereas for the pressure-sintered one this value is much lower, this difference being attributed to the existence of inclusions in the titanium dioxide matrix, which are spatially isolated from the rest of the electron transport element thereby limiting the charge transport process by promoting their premature recombination. PACS 68.37.Lp; 73.61.Le; 81.40.-z; 84.60.Jt     

Resonant-cavity light-emitting diodes: quantum noise and spatial emission characteristics

We demonstrate the interplay between the intensity noise and the spatial emission characteristics of resonant-cavity light-emitting diodes. First, we find that the total aperture intensity noise exhibits a sub-shot noise behavior in a quite large pumping regime. Second, we investigate the angular, spectral, and spatial emission characteristics of the devices by controlling the shape and width of the angular intensity distribution via temperature detuning of the quantum well wavelength and the cavity resonance wavelength. Finally, the angular and aperture resolved intensity noise exhibit a super-shot noise behavior in contrast to that of the total emission. We explain this difference with anticorrelations between various radial components which increase with the temperature-tuned extension of the spatial emission. PACS 85.60.Jb; 42.50.L; 23.20.En     

Purity assessment using the mass balance approach for inorganic in-house certified reference material production at Inmetro

Accreditation and Quality Assurance - The production of Certified Reference Materials (CRMs) is one of the essential activities of the National Institute of Metrology, Quality and Technology...     

Aromatic compounds produced by endophytic fungi isolated from red alga Asparagopsis taxiformis - Falkenbergia stage

Endophytic fungi were isolated from red alga Asparagopsis taxiformis - Falkenbergia stage, collected from the Brazilian coast, and were identified as Annulohypoxylon stygium (AT-03) and A. yungensis (AT-06) based on their macro/micromorphological and molecular features. Bioassay-guided fractionation of the EtOAc extract from laboratory cultures of both strains yielded known compounds pyrogallol from A. stygium, (3R)-scytalone and (3R,4R)-4-hydroxy-scytalone from A. yungensis. Pyrogallol was active against methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli strains. An inactive fraction from A. stygium afforded two additional compounds, (3R,4R)-3,4,5-trihydroxy-1-tetralone and tyrosol. Optically active compounds had their stereochemistry determined by circular dichroism (CD) spectroscopy.     

Determination of cocaine adulterants in human urine by dispersive liquid-liquid microextraction and high-performance liquid chromatography

Analytical and Bioanalytical Chemistry - This study aimed to determine simultaneously five major street cocaine adulterants (caffeine, lidocaine, phenacetin, diltiazem, and hydroxyzine) in human...     

Some trends in the theory of groups with finitely many normalizers

Ricerche di Matematica - This paper provides an account of results and methods from the theory of infinite groups admitting only finitely many normalizers of subgroups with a given property. Some...     

Correction to: Two-Dimensional Culture Systems to Enable Mechanics-Based Assays for Stem Cell-Derived Cardiomyocytes

Experimental Mechanics - The authors would like to correct the sentence “The mass ratio……” in the subsection on Engineered Substrate System in MATERIALS AND METHODS, to read: