Objective Assessment of Internal Nasal Dimensions and Speech Resonance in Individuals With Repaired Unilateral Cleft Lip and Palate After Rhinoseptoplasty

The objective of the current study was to analyze the effects of rhinoseptoplasty on internal nasal dimensions and speech resonance of individuals with unilateral cleft lip and palate, estimated by acoustic rhinometry and nasometry, respectively. Twenty-one individuals (aged 15-46 years) with previously repaired unilateral cleft lip and palate were analyzed before (PRE), and 6 to 9 (POST1) and 12 to 18 months (POST2) after surgery. Acoustic rhinometry was used to measure the cross-sectional areas (CSAs) of segments corresponding to the nasal valve (CSA1), anterior portion (CSA2), and posterior portion (CSA3) of the lower turbinate, and the volumes at the nasal valve (V1) and turbinate (V2) regions at cleft and noncleft sides, before and after nasal decongestion with a topical vasoconstrictor. Nasometry was used to evaluate speech nasalance during the reading of a set of sentences containing nasal sounds and other devoid of nasal sounds. At the cleft side, before nasal decongestion, there was a significant increase (P < 0.05) in mean CSA1 and V1 values at POST1 and POST2 compared with PRE. After decongestion, increased values were also observed for CSA2 and V2 at POST2. No significant changes were observed at the noncleft side. Mean nasalance values at PRE, POST1, an POST2 were not different from each other in both oral and nasal sentences. The measurement of CSAs and volumes by acoustic rhinometry revealed that rhinoseptoplasty provided, in most cases analyzed, a significant increase in nasal patency, without concomitant changes in speech resonance, as estimated by nasalance assessment.

Zirconium oxide anodic films: Optical and structural properties

The photoluminescence of anodically prepared ZrO(2) films was investigated. Morphological and microstructural analyses reveal an oxide surface covered by a high distribution of blisters and the major crystallographic structure is the monoclinic phase with small quantities of tetragonal phase. The photoluminescence reveals a broad emission band in the range between 350 and 650 nm. It was proposed that the photoluminescence mechanism is originated from the emission of a recombination center related to defects (oxygen vacancies) formed during Zr anodization. (C) 2008 Elsevier B.V. All rights reserved.

The effects of anticalcification treatments and hydration on the molecular dynamics of bovine pericardium collagen as revealed by (13)C solid-state NMR

This article describes a solid-state NMR (SSNMR) investigation of the influence of hydration and chemical cross-linking on the molecular dynamics of the constituents of the bovine pericardium (BP) tissues and its relation to the mechanical properties of the tissue. Samples of natural phenetylamine-diepoxide (DE)- and glutaraldehyde (GL)-fixed BP were investigated by (13)C cross-polarization SSNMR to probe the dynamics of the collagen, and the results were correlated to the mechanical properties of the tissues, probed by dynamical mechanical analysis. For samples of natural BP, the NMR results show that the higher the hydration level the more pronounced the molecular dynamics of the collagen backbone and sidechains, decreasing the tissue`s elastic modulus. In contrast, in DE- and GL-treated samples, the collagen molecules are more rigid, and the hydration seems to be less effective in increasing the collagen molecular dynamics and reducing the mechanical strength of the samples. This is mostly attributed to the presence of cross-links between the collagen plates, which renders the collagen mobility less dependent on the water absorption in chemically treated samples. Copyright (C) 2010 John Wiley & Sons, Ltd.

Efficient solutions to robust, semi-implicit discretizations of the immersed boundary method

The immersed boundary method is a versatile tool for the investigation of flow-structure interaction. In a large number of applications, the immersed boundaries or structures are very stiff and strong tangential forces on these interfaces induce a well-known, severe time-step restriction for explicit discretizations. This excessive stability constraint can be removed with fully implicit or suitable semi-implicit schemes but at a seemingly prohibitive computational cost. While economical alternatives have been proposed recently for some special cases, there is a practical need for a computationally efficient approach that can be applied more broadly. In this context, we revisit a robust semi-implicit discretization introduced by Peskin in the late 1970s which has received renewed attention recently. This discretization, in which the spreading and interpolation operators are lagged. leads to a linear system of equations for the inter-face configuration at the future time, when the interfacial force is linear. However, this linear system is large and dense and thus it is challenging to streamline its solution. Moreover, while the same linear system or one of similar structure could potentially be used in Newton-type iterations, nonlinear and highly stiff immersed structures pose additional challenges to iterative methods. In this work, we address these problems and propose cost-effective computational strategies for solving Peskin`s lagged-operators type of discretization. We do this by first constructing a sufficiently accurate approximation to the system`s matrix and we obtain a rigorous estimate for this approximation. This matrix is expeditiously computed by using a combination of pre-calculated values and interpolation. The availability of a matrix allows for more efficient matrix-vector products and facilitates the design of effective iterative schemes. We propose efficient iterative approaches to deal with both linear and nonlinear interfacial forces and simple or complex immersed structures with tethered or untethered points. One of these iterative approaches employs a splitting in which we first solve a linear problem for the interfacial force and then we use a nonlinear iteration to find the interface configuration corresponding to this force. We demonstrate that the proposed approach is several orders of magnitude more efficient than the standard explicit method. In addition to considering the standard elliptical drop test case, we show both the robustness and efficacy of the proposed methodology with a 2D model of a heart valve. (C) 2009 Elsevier Inc. All rights reserved.

Sequential injection analysis (SIA) and response surface methodology: A versatile small volume approach for optimization of photo-Fenton processes

Optimization of photo-Fenton degradation of copper phthalocyanine blue was achieved by response surface methodology (RSM) constructed with the aid of a sequential injection analysis (SIA) system coupled to a homemade photo-reactor. Highest degradation percentage was obtained at the following conditions [H(2)O(2)]/[phthalocyanine] = 7, [H(2)O(2)]/[FeSO(4)] = 10, pH = 2.5, and stopped flow time in the photo reactor = 30 s. The SIA system was designed to prepare a monosegment containing the reagents and sample, to pump it toward the photo-reactor for the specified time and send the products to a flow-through spectrophotometer for monitoring the color reduction of the dye. Changes in parameters such as reagent molar ratios. residence time and pH were made by modifications in the software commanding the SI system, without the need for physical reconfiguration of reagents around the selection valve. The proposed procedure and system fed the statistical program with degradation data for fast construction of response surface plots. After optimization, 97% of the dye was degraded. (C) 2009 Elsevier B.V. All rights reserved.

Keratinocyte growth factor: a new mesothelial targeted therapy to reduce postoperative pericardial adhesions

Background: Several methods have been utilized to prevent pericardial and retrosternal adhesions, but none of them evaluated the mesothelial regenerative hypothesis. There are evidences that the mesothelial trauma reduces pericardial fibrinolytic capability and induces an adhesion process. Keratinocyte growth factor (KGF) has proven to improve mesothelial cells proliferation. This study investigated the influence of keratinocyte growth factor in reducing post-surgical adhesions. Methods: Twelve pigs were operated and an adhesion protocol was employed. Following a stratified randomization, the animals received a topical application of KGF or saline. At 8 weeks, intrapericardial adhesions were evaluated and a severity score was established. The time spent to dissect the adhesions and the amount of sharp dissection used, were recorded. Histological sections were stained with sirius red and morphometric analyses were assessed with a computer-assisted image analysis system. Results: The severity score was lower in the KGF group than in the control group (11.5 vs 17, p = 0.005). The dissection time was lower in the KGF group (9.2 +/- 1.4 min vs 33.9 +/- 9.2 min, p = 0.004) and presented a significant correlation with the severity score (r = 0.83, p = 0.001). A significantly less sharp dissection was also required in the KGF group. Also, adhesion area and adhesion collagen were significantly tower in the KGF group than in the control group. Conclusion: The simulation of pericardial cells with KGF reduced the intensity of postoperative adhesions and facilitated the re-operation. This study suggests that the mesothelial regeneration is the new horizon in anti-adhesion therapies. (C) 2008 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.

Synergism Between Keratinocyte Growth Factor and Carboxymethyl Chitosan Reduces Pericardial Adhesions

Background. Mesothelial injury is the pivot in the development of adhesions. An increase in the proliferation of mesothelial cells was verified by in vitro studies with the use of keratinocyte growth factor (KGF). This study investigated the influence of KGF associated with thermo-sterilized carboxymethyl chitosan (NOCCts) in the reduction of pericardial adhesions. Methods. An induction model of pericardial adhesion was carried out in 24 pigs. Animals were randomly allocated to receive topical application of KGF, KGF + NOCCts, NOCCts, or saline (control). At 8 weeks, intra-pericardial adhesions were evaluated and a severity score was established. The time spent to dissect the adhesions and the amount of sharp dissection used, were recorded. Histologic sections were stained with sirius red for a morphometric evaluation using a computer-assisted image analysis system. Cytokeratin AE1/AE3 immunostaining were employed to identify mesothelial cells. Results. The severity score expressed in median (minimum to maximum), in relation to the control group (17 [15 to 18]), was lower in the KGF + NOCCts group (7 [6 to 9], p < 0.01) followed by the KGF group (11.5 [9 to 12], 0.01 < p < 0.05) and the NOCCts group (12 [9 to 14], p > 0.05). The dissection time was significantly lower in the KGF + NOCCts group (7.1 +/- 0.6 vs 33.9 +/- 9.2 minutes, p < 0.001). A significantly less sharp dissection was also required in the KGF + NOCCts group. In the adhesion segment, a decreased collagen proportion was found in the KGF + NOCCts group (p < 0.05). Mesothelial cells were present more extensively in groups in which KGF was delivered (p = 0.01). Conclusions. The use of KGF associated with NOCCts resulted in a synergic action that decreases postoperative pericardial adhesions in a highly significant way. (Ann Thorac Surg 2010; 90: 566-72) (C) 2010 by The Society of Thoracic Surgeons

Simultaneous analysis of five antidepressant drugs using direct injection of biofluids in a capillary restricted-access media-liquid chromatography-tandem mass spectrometry system

Direct analysis, with minimal sample pretreatment, of antidepressant drugs, fluoxetine, imipramine, desipramine, amitriptyline, and nortriptyline in biofluids was developed with a total run time of 8 min. The setup consists of two HPLC pumps, injection valve, capillary RAM-ADS-C18 pre-column and a capillary analytical C 18 column connected by means of a six-port valve in backflush mode. Detection was performed with ESI-MS/MS and only 1 mu m of sample was injected. Validation was adequately carried out using FLU-d(5) as internal standard. Calibration curves were constructed under a linear range of 1-250 ng mL(-1) in plasma, being the limit of quantification (LOQ), determined as 1 ng mL(-1), for all the analytes. With the described approach it was possible to reach a quantified mass sensitivity of 0.3 pg for each analyte (equivalent to 1.1-1.3 fmol), translating to a lower sample consumption (in the order of 103 less sample than using conventional methods). (C) 2008 Elsevier B.V. All rights reserved.