Reconstructive surgery for burn patients

Reconstructive surgery in burn patients is difficult because of the intense scarring and the necessity to carry out multiple operative procedures for different reconstructive needs in a single patient. The primary aim of the surgeon is to prevent hypertrophic scar by early wound closure, and proper postburn treatment using a combination of silicone gel, splinting, and pressure therapy. Reconstructive procedures should be deferred until the wounds have matured. Accurate preoperative assessment and appreciation of the true tissue deficiency, appropriate application of different reconstructive options, and the establishment of the priorities of reconstruction in relation to individual requirements are essential for a successful outcome. In general, functional needs have to be met before attending to aesthetic concerns and priority should be given to restore active before passive function. Different reconstructive options using direct closure, skin grafts, flaps, free tissue transfer, and tissue expansion are discussed.published_or_final_versio

Analysis of recurrence after surgical treatment of advanced laryngeal carcinoma

The pattern of recurrences after surgical treatment of 276 patients with stage T3 and T4 laryngeal carcinoma was reviewed. Nodal recurrence was the commonest site and occurred mainly in patients with supraglottic and transglottic carcinoma. Distant metastasis was the second commonest site of recurrence, and the most distant metastases developed without locoregional recurrence. Local recurrence alone was uncommon in patients treated with primary surgery.published_or_final_versio

Reconstruction after craniofacial trauma

Management of craniofacial trauma has became a sophisticated branch of reconstructive surgery in the last 20 years. New operative techniques and advanced technologies have evolved to allow much better treatment results to be achieved. The general principles of diagnosis and management of craniofacial trauma are discussed. The approach to individual fractures is also highlighted.published_or_final_versio

Improved management of the donor site of free radial forearm flap

Conference Theme: Challenges to specialists in the 21st centurypublished_or_final_versio

Direct observation of ordered trimers on Si(111)√3×√3 R30°-Au by scanned-energy glancing-angle Kikuchi electron wave-front reconstruction

We report the first atomically resolved images of ordered Au trimers on Si(111)√3×√3R30°-Au using wave-front reconstruction of scanned-energy glancing-angle Kikuchi electron spectra. Each Au image has a resolution (full width at half magnitude) of less than 1 Å . The images indicate that Au trimers are ordered and nonrotated within the surface plane and with respect to the second-layer Si plane providing direct evidence of the conjugate honeycomb-chained-trimer model for the Au-√3 system. © 1996 The American Physical Society.published_or_final_versio

Finding optimal threshold for correction error reads in DNA assembling

Background: DNA assembling is the problem of determining the nucleotide sequence of a genome from its substrings, called reads. In the experiments, there may be some errors on the reads which affect the performance of the DNA assembly algorithms. Existing algorithms, e.g. ECINDEL and SRCorr, correct the error reads by considering the number of times each length-k substring of the reads appear in the input. They treat those length-k substrings appear at least M times as correct substring and correct the error reads based on these substrings. However, since the threshold M is chosen without any solid theoretical analysis, these algorithms cannot guarantee their performances on error correction. Results: In this paper, we propose a method to calculate the probabilities of false positive and false negative when determining whether a length-k substring is correct using threshold M. Based on this optimal threshold M that minimizes the total errors (false positives and false negatives). Experimental results on both real data and simulated data showed that our calculation is correct and we can reduce the total error substrings by 77.6% and 65.1% when compared to ECINDEL and SRCorr respectively. Conclusion: We introduced a method to calculate the probability of false positives and false negatives of the length-k substring using different thresholds. Based on this calculation, we found the optimal threshold to minimize the total error of false positive plus false negative. © 2009 Chin et al; licensee BioMed Central Ltd.published_or_final_versio

Evaluating longitudinal therapy effects via the North Star Ambulatory Assessment

Introduction/Aims: In comparative studies, treatment effects are typically evaluated at a specific time point. When data are collected periodically, an alternative, clinically meaningful approach could be used to assess the totality of treatment effects. We applied a well-developed analytical procedure for evaluating longitudinal treatment effects using North Star Ambulatory Assessment (NSAA) data for illustration. / Methods: The NSAA comprises 17 scorable items/outcomes that measure changes in motor function. Using NSAA data from the published ataluren phase 3, randomized, placebo-controlled trial (NCT01826487), cumulative counts of failures to perform each item (transition from 2/1 [able/impaired] to 0 [unable]) were collected at specified time points for each patient over 48 wk. Treatment group-wise mean cumulative item failure count curves were constructed, comparing ataluren versus placebo and deflazacort versus prednisone/prednisolone among placebo-treated patients. The steeper the curve, the worse the outcome. A clinically meaningful summary of the between-group difference was provided for each comparison. / Results: The curve was uniformly steeper for placebo than ataluren after 16 wk and for prednisone/prednisolone than deflazacort after 8 wk. The two curves in each comparison continued to diverge thereafter, indicating sustained treatment benefits over time. Using a unique analytical approach, cumulative failure rates were reduced, on average, by 27% for ataluren versus placebo (rate ratio, 0.73; 95% confidence interval [CI], 0.55–0.97; p = .027) and 28% for deflazacort versus prednisone/prednisolone (rate ratio, 0.72; 95% CI, 0.53–0.96; p = .028). / Discussion: Unlike fixed-time analyses, this analytical approach enabled demonstration of cumulative, longitudinal treatment effects over time using repeatedly measured NSAA observations

A constitutive model for cytoskeletal contractility of smooth muscle cells

The constitutive model presented in this article aims to describe the main bio-chemo-mechanical features involved in the contractile response of smooth muscle cells, in which the biochemical response is modelled by extending the four-state Hai–Murphy model to isotonic contraction of the cells and the mechanical response is mainly modelled based on the phosphorylation-dependent hyperbolic relation between isotonic shortening strain rate and tension. The one-dimensional version of the model is used to simulate shortening-induced deactivation with good agreement with selected experimental measurements. The results suggest that the Hai–Murphy biochemical model neglects the strain rate effect on the kinetics of cross-bridge interactions with actin filaments in the isotonic contractions. The two-dimensional version and three-dimensional versions of the model are developed using the homogenization method under finite strain continuum mechanics framework. The two-dimensional constitutive model is used to simulate swine carotid media strips under electrical field stimulation, experimentally investigated by Singer and Murphy, and contraction of a hollow airway and a hollow arteriole buried in a soft matrix subjected to multiple calcium ion stimulations. It is found that the transverse deformation may have significant influence on the response of the swine carotid medium. In both cases, the orientation of the maximal value of attached myosin is aligned with the orientation of maximum principal stress

Living donor liver transplantation without the use of blood products.

We report on two patients who presented with unresectable hepatocellular carcinoma complicating hepatitis B liver cirrhosis. After evaluation, both patients were accepted for liver transplantation. Being aware of the scarce availability of cadaveric liver grafts and the long waiting time, family members volunteered to be donors for the two patients. Living donor liver transplantation using right lobe liver grafts, including the middle hepatic vein, was subsequently performed without the use of blood products in both the donors and recipients. All involved recovered uneventfully from their respective operations.published_or_final_versio

Semimetallic behavior in Heusler-type Ru2TaAl and thermoelectric performance improved by off-stoichiometry

We report a study of the temperature-dependent electrical resistivity, Seebeck coefficient, thermal conductivity, specific heat, and Al27 nuclear magnetic resonance (NMR) in Heusler-type Ru2TaAl, to shed light on its semimetallic behavior. While the temperature dependence of the electrical resistivity exhibits semiconductorlike behavior, the analysis of low-temperature specific heat reveals a residual Fermi-level density of states (DOS). Both observations can be realized by means of a semimetallic scenario with the Fermi energy located in the pseudogap of the electronic DOS. The NMR Knight shift and spin-lattice relaxation rate show activated behavior at higher temperatures, attributing to the thermally excited carriers across a pseudogap in Ru2TaAl. From the first-principles band structure calculations, we further provide a clear picture that an indirect overlap between electron and hole pockets is responsible for the formation of a pseudogap in the vicinity of the Fermi level of Ru2TaAl. In addition, an effort for improving the thermoelectric performance of Ru2TaAl has been made by investigating the thermoelectric properties of Ru1.95Ta1.05Al. We found significant enhancements in the electrical conductivity and Seebeck coefficient and marked reduction in the thermal conductivity via the off-stoichiomet ric approach. This leads to an increase in the figure-of-merit ZT value from 6.1×10-4 in Ru2TaAl to 3.4×10-3 in Ru1.95Ta1.05Al at room temperature. In this respect, a further improvement of thermoelectric performance based on Ru2TaAl through other off-stoichiometric attempts is highly probable