668 research outputs found

    Defective Spermatogenesis in Cryptorchid Testes: Cause or Effect?

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    Mucosal Thickening of Maxillary Sinuses of CLP vs non-CLP patients

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    poster abstractObjectives: The objective of this retrospective radiographic study was to compare mucosal thickening of maxillary sinuses of patients with cleft lip and palate (CLP) vs. non-CLP. Methods: Following IRB approval, three-dimensional cone beam computerized tomographs (CBCT; i-CAT) of children with unilateral CLP and children without CLP (age and gender matched; 8-14yoa; n=15ea) were selected randomly from pre-existing orthodontic records. Following reliability studies, one investigator segmented both sinuses from each CBCT using Dolphin-3D Imaging software. The sinuses were separated coronally into .4mm slices anterioposteriorly. Bony sinuses and airspaces were outlined manually on each slice. Software calculated total sinus and airspace area. Areas were summed and multiplied by slice thickness to determine volume. Mucosal thickening was the difference between total sinus and airspace volumes. Percent mucosal thickening was calculated. Since no significant differences existed between cleft (left) and noncleft (right) sides of either patient group (p>.05), sinuses for each group were pooled (n=30 ea). Significant differences in total sinus, airspace, mucosal thickening volumes and % mucosal thickening were determined using paired t-tests, accepting p<0.05 as significant. Principal Component Analysis (PCA) scatterplots were used to determine patterns of multivariate variation based on group, age, and sex. MANOVA was used to confirm PCA findings. Reliability was determined using Intraclass Correlations (ICC). Results: Reliability was excellent (ICC>0.99). The CLP total sinus and airspace volume were significantly smaller and mucosal thickening and % mucosal thickening were significantly greater than non-CLP sinuses (all p<.024). PCA showed that 89.6% of sample variance was explained by PC axis 1 and 2 (group and age). Age group 8-9yrs showed more separation with 13-14yrs than with 10-12yrs. MANOVA confirmed a significant effect of sample (p=.001) and age (p=.007)

    Molar-Incisor hypomineralization in controls vs CLP with primary or prior to secondary alveolar grafts

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    poster abstractMolar incisor hypomineralization (MIH) is a congenital defect of unknown etiology that can affect both esthetics and cariogenic susceptibility. The objective of this study was to determine whether MIH is greater in patients with cleft lip and palate (CLP) who underwent primary alveolar grafting (PAG) as compared to CLP prior to secondary alveolar grafting (SAG) and to controls. A retrospective analysis of intraoral photographs of 13 (10M:3F; 8.9 ± 1.2 yrs) CLP patients who underwent a PAG, 27 (18M:9F;10.0 ± 2.1 yrs) CLP prior to SAG, and 60 (30M:30F; 12.4 ± 1.8 yrs) controls without CLP was performed. Mantel-Haenszel chi-square tests were used to compare the three groups for differences in MIH scores and Wilcoxon Rank Sum tests were used to compare the groups for differences in average MIH scores. A 5% significance level was used for all tests. MIH scores were significantly higher for the PAG and SAG groups compared to the control group (p<0.001). The PAG group had significantly higher incisor MIH (p=0.016) than the SAG group. MIH average scores were significantly higher for the two graft groups compared to the controls (p<0.0001). The PAG group had significantly higher average MIH score and average MIH score for incisors than the SAG group (p=0.03). The results suggest that CLP patients, in general, have significantly greater MIH compared with controls and CLP with PAGs have significantly greater MIH in the incisor region than CLP waiting for SAGs. The increased severity of MIH could be related to the grafting during the time of incisor crown formation

    The influence of cell adsorbent interactions on protein adsorption in expanded beds

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    Expanded bed adsorption (EBA) is a primary recovery operation allowing the adsorption of proteins directly from unclarified feedstock, e.g. culture suspensions, homogenates or crude extracts. Thus solid-liquid separation is combined with adsorptive purification in a single step. The concept of integration requires that the solid components of the feed solution are regarded as a part of the process, which influences stability, reproducibility, and overall performance. This aspect is investigated here at the example of the influence of presence and concentration of intact yeast cells (S. cerevisiae) on the adsorption of model proteins (hen egg white lysozyme and bovine serum albumin) to various stationary phases (cation and anion-exchange, hydrophobic interaction, immobilised metal affinity). The interaction of the cells with the adsorbents is determined qualitatively and quantitatively by a pulse response method as well as by a finite bath technique under different operating conditions. The consequence of these interactions for the stability of expanded beds in suspensions of varying cell concentration is measured by residence time distributions (RTDs) after tracer pulse injection (NaBr, LiCl). Analysis of the measured RTD by the PDE model allows the calculation of the fraction of perfectly fluidised bed (φ), a parameter which may be regarded as a critical quantity for the estimation of the quality of fluidisation of adsorbents in cell containing suspensions. The correlation between bed stability and performance is made by analysing the breakthrough of model proteins during adsorption from unclarified yeast culture broth. A clear relationship is found between the degree of cell/adsorbent interaction, bed stability in terms of the φ parameter, and the sorption efficiency. Only beds characterised by a φ; value larger than 0.8 in the presence of cells will show a conserved performance compared to adsorption from cell free solutions. A drop in φ, which is due to interactions of the fluidised adsorbent particles with cells from the feed, will directly result in a reduced breakthrough efficiency. The data presented highlight the importance of including the potential interaction of solid feedstock components and the expanded adsorbents into the design of EBA processes, as the interrelation found here is a key factor for the overall performance of EBA as a truly integrated operation. © 2000 Elsevier Science B.V.Fil: Fernandez Lahore, Hector. Universitat Dusseldorf; Alemania. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Geilenkirchen, S.. Universitat Dusseldorf; AlemaniaFil: Boldt, K.. Universitat Dusseldorf; AlemaniaFil: Nagel, A.. Universitat Dusseldorf; AlemaniaFil: Kula, M. R.. Universitat Dusseldorf; AlemaniaFil: Thömmes, J.. Universitat Dusseldorf; Alemani

    Three-dimensional airway volumes and most constricted areas in children

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    poster abstractObjective: The objectives of this retrospective study using cone beam computed tomography (CBCT) were to determine if there are differences in the volume of various airway segments and the most constricted area (MCA) of children with different dentoskeletal patterns. Methods: The initial CBCTs of 83 orthodontic patients (30 Angle’s Class I; 26 Class II; and 27 Class III) were collected from a private orthodontic office. Following reliability studies, various parameters of the craniofacial complex, airway volume, and MCA were measured utilizing Dolphin 3D software. Comparisons among the three dental and the skeletal malocclusion classes were performed using one-way ANOVA and Fishers Protected Least Significant. Associations of the airway volumes and the MCA with other parameters were determined using correlation coefficients, accepting p < 0.05 as significant for all tests. Results: Maxillary right sinus volume was the only airway segment showing significant difference among different dental classes. Maxillary sinus volume also correlated moderately with anterior facial height and mandibular length. No significant differences were found between the MCA and different dentoskeletal classifications. Conclusions: The only significant difference in airway parameters among the dentoskeletal classes was that the dental Class II subjects had greater right sinus volume than the other classes. Shorter anterior facial height or mandibular length could be indicators for decreased airway volume in children. Funding: IUSD Graduate Research Committee, IUPUI Three-Dimensional Imaging of the Craniofacial Complex Center, Jarabak Endowed Professorshi

    Nonequilibrium coupled Brownian phase oscillators

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    A model of globally coupled phase oscillators under equilibrium (driven by Gaussian white noise) and nonequilibrium (driven by symmetric dichotomic fluctuations) is studied. For the equilibrium system, the mean-field state equation takes a simple form and the stability of its solution is examined in the full space of order parameters. For the nonequilbrium system, various asymptotic regimes are obtained in a closed analytical form. In a general case, the corresponding master equations are solved numerically. Moreover, the Monte-Carlo simulations of the coupled set of Langevin equations of motion is performed. The phase diagram of the nonequilibrium system is presented. For the long time limit, we have found four regimes. Three of them can be obtained from the mean-field theory. One of them, the oscillating regime, cannot be predicted by the mean-field method and has been detected in the Monte-Carlo numerical experiments.Comment: 9 pages 8 figure

    Irreversible and reversible modes of operation of deterministic ratchets

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    We discuss a problem of optimization of the energetic efficiency of a simple rocked ratchet. We concentrate on a low-temperature case in which the particle's motion in a ratchet potential is deterministic. We show that the energetic efficiency of a ratchet working adiabatically is bounded from above by a value depending on the form of ratchet potential. The ratchets with strongly asymmetric potentials can achieve ideal efficiency of unity without approaching reversibility. On the other hand we show that for any form of the ratchet potential a set of time-protocols of the outer force exist under which the operation is reversible and the ideal value of efficiency is also achieved. The mode of operation of the ratchet is still quasistatic but not adiabatic. The high values of efficiency can be preserved even under elevated temperatures
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