527 research outputs found

    Effectiveness of maxillary protraction using a hybrid hyrax-facemask combination: A controlled clinical study

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    OBJECTIVE: To evaluate the treatment effects of a hybrid hyrax-facemask (FM) combination in growing Class III patients. MATERIAL AND METHODS: A sample of 16 prepubertal patients (mean age, 9.5 ± 1.6 years) was investigated by means of pre- and posttreatment cephalograms. The treatment comprised rapid palatal expansion with a hybrid hyrax, a bone- and toothborne device. Simultaneously, maxillary protraction using an FM was performed. Mean treatment duration was 5.8 ± 1.6 months. The treatment group was compared with a matched control group of 16 untreated Class III subjects. Statistical comparisons were performed with the Mann-Whitney U-test. RESULTS: Significant improvement in skeletal sagittal values could be observed in the treatment group over controls: SNA: 2.4°, SNB: −1.7°, Co-Gn: −2.3 mm, Wits appraisal: 4.5 mm. Regarding vertical changes, maintenance of vertical growth was obtained as shown by a small nonsignificant increase of FMA and a small significant decrease of the Co-Go-Me angle. CONCLUSIONS: The hybrid hyrax-FM combination was found to be effective for orthopedic treatment in growing Class III patients in the short term. Favorable skeletal changes were observed both in the maxilla and in the mandible. No dentoalveolar compensations were found

    Sample preservation and storage significantly impact taxonomic and functional profiles in metaproteomics studies of the human gut microbiome

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    With the technological advances of the last decade, it is now feasible to analyze microbiome samples, such as human stool specimens, using multi-omic techniques. Given the inherent sample complexity, there exists a need for sample methods which preserve as much information as possible about the biological system at the time of sampling. Here, we analyzed human stool samples preserved and stored using different methods, applying metagenomics as well as metaproteomics. Our results demonstrate that sample preservation and storage have a significant effect on the taxonomic composition of identified proteins. The overall identification rates, as well as the proportion of proteins from were much higher when samples were flash frozen. Preservation in RNAlater overall led to fewer protein identifications and a considerable increase in the share of , as well as . Additionally, a decrease in the share of metabolism-related proteins and an increase of the relative amount of proteins involved in the processing of genetic information was observed for RNAlater-stored samples. This suggests that great care should be taken in choosing methods for the preservation and storage of microbiome samples, as well as in comparing the results of analyses using different sampling and storage methods. Flash freezing and subsequent storage at -80 °C should be chosen wherever possible

    Comparison of low--energy resonances in 15N(alpha,gamma)19F and 15O(alpha,gamma)19Ne and related uncertainties

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    A disagreement between two determinations of Gamma_alpha of the astro- physically relevant level at E_x=4.378 MeV in 19F has been stated in two recent papers by Wilmes et al. and de Oliveira et al. In this work the uncertainties of both papers are discussed in detail, and we adopt the value Gamma_alpha=(1.5^{+1.5}_{-0.8})10^-9eV for the 4.378 MeV state. In addition, the validity and the uncertainties of the usual approximations for mirror nuclei Gamma_gamma(19F) approx Gamma_gamma(19Ne), theta^2_alpha(19F) approx theta^2_alpha(19Ne) are discussed, together with the resulting uncertainties on the resonance strengths in 19Ne and on the 15O(alpha,gamma)19Ne rate.Comment: 9 pages, Latex, To appear in Phys. Rev.

    Fine‐scale seascape genomics of an exploited marine species, the common cockle Cerastoderma edule, using a multimodelling approach

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    Population dynamics of marine species that are sessile as adults are driven by oceanographic dispersal of larvae from spawning to nursery grounds. This is mediated by life-history traits such as the timing and frequency of spawning, larval behaviour and duration, and settlement success. Here, we use 1725 single nucleotide polymorphisms (SNPs) to study the fine scale spatial genetic structure in the commercially important cockle species Cerastoderma edule and compare it to environmental variables and current-mediated larval dispersal within a modelling framework. Hydrodynamic modelling employing the NEMO Atlantic Margin Model (AMM15) was used to simulate larval transport and estimate connectivity between populations during spawning months (April - September), factoring in larval duration and inter-annual variability of ocean currents. Results at neutral loci reveal the existence of three separate genetic clusters (mean FST=0.021) within a relatively fine spatial scale in the northwest Atlantic. Environmental Association analysis indicates that oceanographic currents and geographical proximity explain over 20% of the variance observed at neutral loci, while genetic variance (71%) at outlier loci was explained by sea surface temperatures extremes. These results fill an important knowledge gap in the management of a commercially important and overexploited species, bringing us closer to understanding the role of larval dispersal in connecting populations at a fine geographical scale

    NON-INVASIVE IN VIVU TEhlPERATURE MAPPING OF ULTRASOUND HEATING USING MAGNETIC RESONANCE TECHNIQUES

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    Abstract-A major problem with conventional methods of measuring heating in vhu is that they are invasive and therefore interfere with heat propagation. A sensitive non-invasi\v method for temperature measurement using in \ivo magnetic resonance spectroscopy (MRS) of the temperature dependent chemical shift of the cobalt(II1) nucleus has been developed. Initial experiments demonstrate that this technique can be used to measure ultrasound induced temperature changes in the liver. Tris(ethy1enediamine) cobalt(II1) trichloride was encapsulated in liposomes and injected into seven rats. Heating was performed using a calibrated unfocused transducer operating at 3.41 MHz. After 5 minutes of CW ultrasound exposure, the chemical shift of the cobalt complex indicated that the temperature rise within the liver was 2.0k1.2 OC. This was seen to return to normal upon cessation of heating. The acoustic power was determined in a water bath using a calibrated hydrophone. Theoretical calculations based on the transducer calibration characteristics using the monopole-source solution for estimating tissue temperature increase yielded 2.0 OC based on steady state conditions. These results indicate that experimental values agree with the heating theory
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