85 research outputs found
The predictive role of pelvic magnetic resonance in the follow up of spontaneous or induced puberty in turner syndrome
Puberty is a critical age for patients with Turner syndrome (TS): infertility is reported to be linked to karyotype and spontaneous puberty and menarche occur in approximately 30% of patients, especially in mosaicism. However, it is not always predictable considering hormonal pattern and pelvic transabdominal ultrasound scan (US). The aim of the study is to compare the accuracy of Magnetic Resonance Imaging (MRI) and US to evaluate uterine and gonads volume, to visualize the presence of follicles and to predict spontaneous puberty and menarche in girls with TS. In a retrospective study, we evaluated 19 TS patients (age: 9-16 years), who underwent transabdominal pelvic US and pelvic MRI as required by parents. We correlated pelvic imaging with karyotype, hormonal data and pubertal outcome, and we compared US resolution to MRI. MRI revealed a higher accuracy in the study of uterus and ovaries, and permitted to measure ovaries not visualized by US. Ovarian volume, the presence of follicles and the occurrence of spontaneous puberty were not related to the karyotype; spontaneous puberty started in one patient with a karyotype 45,X and in two patients with mosaicism (45,X/46,XX; 47,XXX/45, X). Ovarian follicles were relieved by MRI in patients with a spontaneous menarche and the persistence of menstrual cycles correlated with an ovarian volume corresponding to Tanner stage 3-4. We stress the role of MRI in the follow-up of TS adolescents, guide in the choice of the timing of treatment
Low field vortex matter in YBCO: an atomic beam magnetic resonance study
We report measurements of the low field structure of the magnetic vortex
lattice in an untwinned YBCO single-crystal platelet. Measurements were carried
out using a novel atomic beam magnetic resonance (ABMR) technique. For a 10.7 G
field applied parallel to the c-axis of the sample, we find a triangular
lattice with orientational order extending across the entire sample. We find
the triangular lattice to be weakly distorted by the a-b anisotropy of the
material and measure a distortion factor, f = 1.16. Model-experiment
comparisons determine a penetration depth, lambda_ab = 140 (+-20) nm. The paper
includes the first detailed description of the ABMR technique. We discuss both
technical details of the experiment and the modeling used to interpret the
measurements.Comment: 44 pages, 13 figures, submitted to Phys. Rev. B Revision includes
Postscript wrapped figures + minor typo
Standard addition method based on four-way PARAFAC decomposition to solve the matrix interferences in the determination of carbamate pesticides in lettuce using excitationâemission fluorescence data
The simultaneous determination of two carbamate pesticides (carbaryl and carbendazim) and of the degradation product of carbaryl (1-naphthol) in iceberg lettuce was achieved by means of PARAFAC decomposition and excitationâemission fluorescence matrices. A standard addition method for a calibration based on four-way data was applied using different dilutions of the extract from iceberg lettuce as a fourth way that provided the enough variation of the matrix to carry out the four-way analysis. A high fluorescent overlapping existed between the three analytes and the fluorophores of the matrix. The identification of two fluorescent matrix constituents through the four-way model enabled to know the matrix contribution in each dilution of the extract. This contribution was subtracted from the previous signals and a subsequent three-way analysis was carried out with the tensors corresponding to each dilution. The PARAFAC decomposition of these resulting tensors showed a CORCONDIA index equal to 99%. For the identification of the analytes, the correlation between the PARAFAC spectral loadings and the reference spectra has been used. The trueness of the method, in the concentration range studied, was guaranteed because there was neither constant nor proportional bias according to the appropriate hypothesis tests. The best recovery percentages were obtained with the data from the most diluted extract, being the results: 127.6% for carbaryl, 125.55% for carbendazim and 87.6% for 1-naphthol. When the solvent calibration was performed, the decision limit (CCα) and the capability of detection (CCÎČ) values, in x0=0, were 2.21 and 4.38 ÎŒg Lâ1 for carbaryl, 4.87 and 9.64 ÎŒg Lâ1 for carbendazim; and 3.22 and 6.38 ÎŒg Lâ1 for 1-naphthol, respectively, for probabilities of false positive and false negative fixed at 0.05. However, these values were 5.30 and 10.49 ÎŒg Lâ1 for carbaryl, 18.05 and 35.73 ÎŒg Lâ1 for carbendazim; and 1.92 and 3.79 ÎŒg Lâ1 for 1-naphthol, respectively, when the matrix-matched calibration using the most diluted extract was carried out in the recovery study.Ministerio de EconomĂa y Competitividad(CTQ2011-26022)
and JuntadeCastillayLeĂłn(BU108A11-2)
Melting and Dimensionality of the Vortex Lattice in Underdoped YBa2Cu3O6.60
Muon spin rotation measurements of the magnetic field distribution in the
vortex state of the oxygen deficient high-Tc superconductor YBa{2}Cu{3}O{6.60}
reveal a vortex-lattice melting transition at much lower temperature than that
in the fully oxygenated material. The transition is best described by a model
in which adjacent layers of ``pancake'' vortices decouple in the liquid phase.
Evidence is also found for a pinning-induced crossover from a solid 3D to
quasi-2D vortex lattice, similar to that observed in the highly anisotropic
superconductor Bi{2+x}Sr{2-x}CaCu{2}O{8+y}.Comment: 8 pages, 4 figures, 5 postscript file
Identification and quantification of carbamate pesticides in dried lime tree flowers by means of excitation-emission molecular fluorescence and parallel factor analysis when quenching effect exists
A non-separative, fast and inexpensive spectrofluorimetric method based on the second order calibration of excitation-emission fluorescence matrices (EEMs) was proposed for the determination of carbaryl, carbendazim and 1-naphthol in dried lime tree flowers. The trilinearity property of three-way data was used to handle the intrinsic fluorescence of lime flowers and the difference in the fluorescence intensity of each analyte. It also made possible to identify unequivocally each analyte. Trilinearity of the data tensor guarantees the uniqueness of the solution obtained through parallel factor analysis (PARAFAC), so the factors of the decomposition match up with the analytes. In addition, an experimental procedure was proposed to identify, with three-way data, the quenching effect produced by the fluorophores of the lime flowers. This procedure also enabled the selection of the adequate dilution of the lime flowers extract to minimize the quenching effect so the three analytes can be quantified. Finally, the analytes were determined using the standard addition method for a calibration whose standards were chosen with a D-optimal design.
The three analytes were unequivocally identified by the correlation between the pure spectra and the PARAFAC excitation and emission spectral loadings. The trueness was established by the accuracy line âcalculated concentration versus added concentrationâ in all cases. Better decision limit values (CCα), in x0 = 0 with the probability of false positive fixed at 0.05, were obtained for the calibration performed in pure solvent: 2.97 ÎŒg Lâ1 for 1-naphthol, 3.74 ÎŒg Lâ1 for carbaryl and 23.25 ÎŒg Lâ1 for carbendazim. The CCα values for the second calibration carried out in matrix were 1.61, 4.34 and 51.75 ÎŒg Lâ1 respectively; while the values obtained considering only the pure samples as calibration set were: 2.65, 8.61 and 28.7 ÎŒg Lâ1, respectively.theMinisteriodeEconomĂayCompetitividad(CTQ2011-26022)
and JuntadeCastillayLeĂłn(BU108A11-2
Correction to: The Italian version of the Juvenile Arthritis Multidimensional Assessment Report (JAMAR)
The family name of author Francesco La Torre was incorrect in the published article. The correct family name should read as La Torre F
Polymorphism: an evaluation of the potential risk to the quality of drug products from the FarmĂĄcia Popular Rede PrĂłpria
Polymorphism in solids is a common phenomenon in drugs, which can lead to compromised quality due to changes in their physicochemical properties, particularly solubility, and, therefore, reduce bioavailability. Herein, a bibliographic survey was performed based on key issues and studies related to polymorphism in active pharmaceutical ingredient (APIs) present in medications from the Farmácia Popular Rede Própria. Polymorphism must be controlled to prevent possible ineffective therapy and/or improper dosage. Few mandatory tests for the identification and control of polymorphism in medications are currently available, which can result in serious public health concerns
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