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Selected AbstractsA continued-fraction-based high-order transmitting boundary for wave propagation in unbounded domains of arbitrary geometryINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 2 2008Mohammad Hossein Bazyar Abstract A high-order local transmitting boundary is developed to model the propagation of elastic waves in unbounded domains. This transmitting boundary is applicable to scalar and vector waves, to unbounded domains of arbitrary geometry and to anisotropic materials. The formulation is based on a continued-fraction solution of the dynamic-stiffness matrix of an unbounded domain. The coefficient matrices of the continued fraction are determined recursively from the scaled boundary finite element equation in dynamic stiffness. The solution converges rapidly over the whole frequency range as the order of the continued fraction increases. Using the continued-fraction solution and introducing auxiliary variables, a high-order local transmitting boundary is formulated as an equation of motion with symmetric and frequency-independent coefficient matrices. It can be coupled seamlessly with finite elements. Standard procedures in structural dynamics are directly applicable for evaluating the response in the frequency and time domains. Analytical and numerical examples demonstrate the high rate of convergence and efficiency of this high-order local transmitting boundary. Copyright © 2007 John Wiley & Sons, Ltd. [source] Unit-cell determination from randomly oriented electron-diffraction patternsACTA CRYSTALLOGRAPHICA SECTION D, Issue 7 2009Linhua Jiang Unit-cell determination is the first step towards the structure solution of an unknown crystal form. Standard procedures for unit-cell determination cannot cope with data collections that consist of single diffraction patterns of multiple crystals, each with an unknown orientation. However, for beam-sensitive nanocrystals these are often the only data that can be obtained. An algorithm for unit-cell determination that uses randomly oriented electron-diffraction patterns with unknown angular relationships is presented here. The algorithm determined the unit cells of mineral, pharmaceutical and protein nanocrystals in orthorhombic high- and low-symmetry space groups, allowing (well oriented) patterns to be indexed. [source] Thyroid fine needle aspiration: the morphological features on ThinPrep® slide preparations.CYTOPATHOLOGY, Issue 6 2003Eighty cases with histological control This study had several purposes: to define cytomorphological features of thyroid cells that might be modified by alcohol fixation; to optimize May-Grünwald,Giemsa (MGG) staining on ThinPrep® (TP; Cytyc Inc., Bexborough, MA, USA) slides and to compare the diagnostic accuracy of slides prepared by a liquid-based method with those obtained by conventional technique. This study included 120 cases of ultrasound-guided fine needle aspiration (FNA) of the thyroid and 55 FNAs performed on surgically resected thyroid specimens. Histological control was available in 80 cases. In the first group of 120 FNAs, a split-sample technique was used for the TP. Three screenings were performed: first, an individual screening of the conventional smears (CS) and of the TP, a second screening to compare cells observed on the TP with the histological control and a third screening to assess the previously defined diagnostic criteria. Twenty-seven TP cases (22%) were considered unsatisfactory for diagnosis compared with 10 in CS (8%). The high rate of unsatisfactory cases with TP is likely to be due to the use of the split-sample technique. The sensitivity was 94% for CS and 81% for TP. The specificity was 67% and 60% for CS and TP, respectively. Two occult papillary carcinomas were missed by both methods. As for the MGG staining, the modified technique used for TP resulted in the same quality as the standard procedure. Conversely, TP did however induce uncommon morphological features. In this study, sensitivity and specificity levels are higher for CS than for TP; the difference may be explained by the fact that the methanol fixative used for TP induces some cytological alterations, especially in oncocytic tumours and lymphocytic thyroïditis. [source] SECOND LOOK COLONOSCOPY: INDICATION AND REQUIREMENTSDIGESTIVE ENDOSCOPY, Issue 2009Jean-Francois Rey Background:, There are circumstances when a colonoscopy should be repeated after a short interval following the first endoscopic procedure which has not completely fulfilled its objective. Review of the literature:, A second look colonoscopy is proposed when there remains a doubt about missed neoplastic lesions, either because the intestinal preparation was poor or because the video-endoscope did not achieved a complete course in the colon. The second look colonoscopy is also proposed at a short interval when it is suspected that the endoscopic removal of a single or of multiple neoplastic lesions was incomplete and that a complement of treatment is required. When the initial endoscopic procedure has completely fulfilled its objective, a second look colonoscopy can be proposed at longer intervals in surveillance programs. The intervals in surveillance after polypectomy are now adapted to the initial findings according to established guidelines. This also applies to the surveillance of incident focal cancer in patients suffering from a chronic inflammatory bowel disease. Conclusion:, Finally, in most developed countries, a priority is attributed to screening of colorectal cancer and focus is given on quality assurance of colonoscopy which is considered as the gold standard procedure in the secondary prevention of colorectal cancer. [source] Occurrence and fate of micropollutants in the Vidy Bay of Lake Geneva, Switzerland.ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 8 2010Part I: Priority list for environmental risk assessment of pharmaceuticals Abstract Pharmaceuticals are substances designed to have a biological effect in humans. Their presence in the environment, especially in surface waters, is of increasing concern because of their potential risk to non-target species. A large number of pharmaceuticals are on the market; for example, approximately 2,000 active ingredients are approved in Europe, and many of them have already been detected in surface water. It is therefore crucial to select the substances that may do the most harm to the environment prior to performing measurements and extensive risk assessment. In the present study, a method to determine a list of pharmaceuticals to survey in surface water is proposed. Inclusion of substances on the list was based on a screening procedure, the analytical feasibility, and previous knowledge of pharmaceuticals detected in water. The screening procedure proposed here is an improvement on the standard procedure of the European Medicine Evaluation Agency (EMEA). It is designed to decrease the number of pharmaceuticals to be evaluated in a stepwise manner, thus decreasing the number of data necessary for the evaluation. We applied our approach to determine a list of 37 pharmaceuticals and four hormones to survey in a specific region of Switzerland, the Lake Geneva area, and discussed the advantages and weak points of the method. Environ. Toxicol. Chem. 2010; 29:1649,1657. © 2010 SETAC [source] Theoretical framework for the distribution of trace metals among the operationally defined speciation phases of a sedimentENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 4 2001René A. Nome Abstract The use of a model based on Langmuir's isotherm to evaluate the metal associated with separate geochemical phases of a sediment is proposed and its validity tested with sediments of certified composition. The model takes into account a standard procedure for a certified reference material (CRM601), which defines, experimentally, a set of sequential extractions that divide the sediment into four operational fractions. The derived equations allow the treatment of data from sediment of Flumendosa Lake, Italy, and certified material CRM601 and also allow the computation of corrected concentrations, i.e., the metal affinities for each fraction. Experimental values for Ni show its low sensitivity and an equal distribution among different phases, which suggests a similar adsorption mechanism in all cases. In the case of Cd, the corrected concentration in the Fe/Mn oxide phase is nine times higher than for the residual fraction. For sediment of the Bèsos River, Spain, results show the percentage distribution of Ni over different fractions. Affinity values for Ni on a Flumendosa Lake sediment have also been calculated. The present model is simple to apply and shows satisfactory agreement with experimental data. [source] Molecular Genetic Study on Angelman Syndrome Patients without a Chromosomal DeletionEPILEPSIA, Issue 2000Shinji Saitoh Purpose: Angelman syndrome (AS) is a ncurobehavioral disorder characterized by severe mental retardation, easily cvoked laughter, ataxic gait, and epilepsy. Epilepsy associated with AS is characterized by early childhood onset gencralized seizures with profound EEG abnormalities. Therefore, AS is a good human model for genetic epilepsy syndromes. Approximately 70% of AS cases are caused by maternal deletions of chromosomc 15q I I-qI3; whereas, 30% are not associated with a chromosomal dcletion. Thcse non-deletion AS patients are caused by paternal uniparental disomy (UPD), imprinting mutation (IM), or loss-or-function mutations of the UBE3A gene, cach of which predisposes different recurrence risk. To elucidate molecular etiology of non-dclction AS patients, we investigated 34 AS patients without a chromosomal deletion. Methods: Thirty sporadic AS patients, and 4 familial AS patients (2 families of 2 sibs) were enrolled to the study. The diagnosis of AS was based on Williams' criteria (Williams et al., Am J Med Genet 1995, 56: 237). Genomic DNA was extracted from peripheral blood by a standard procedure. DNA mcthylation tcst at SNRPN locus and genotyping using 7 highly informative PCR-based polymorphisms within 15q I I - q I3 were carried out to identify UPD and IM. When both UPD and IM were ruled out, the patients were classified :LS non-UPD, non-IM. For thcsc non-UPD, non-1M paticnts, UBE3A mutations were screened by PCR-SSCP analysis using 10 sets ofprimcrs covering all coding exons. Results: Among 30 sporadic patients, I UPD and 3 IM patients were identified, and the remaining 26 patients were classified as non-UPD, non-IM. Among 4 familial patients, 2 sibs from I family were detected as IM, whcrcas 2 sibs from another family were classified as non-UPD, non-IM. No UBE3A mutations were identified within 26 sporadic and 2 familial non-UPD, non-IM patients. Conclusion: Threc molecular classes were identified for noindeletion AS patients. Therefore, the underlying genetic mechanism was dcmonstratcd to be complex for AS patients without a chromosomal deletion. Combination of the DNA methylation test and PCR-based polymorphisms was sufficient to detect UPD and IM patients. Because recurrence risk is low for UPD and high lor IM, systematic molecular investigation including the DNA methylation test and PCR-based polymorphisms should bc donc for non-delction AS paticnts for genetic counscling purpose. A majority of non-deletion patients were classified as noii-UPD, non-1M. Although, approximate 30% of non-UPD, nonIM patients arc rcportcd to have UBE3A mutations, no such mutations were identified in our study. An underlying molecular mechanism was not rcvealcd for this group of patients, and therefore, assessment of recurrence risk was difficult. Further investigation is necessary for noii-UPD, non-1M paticnts. [source] Autologous transplantation in relapsed and refractory Hodgkin's diseaseEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 2005Andreas Josting Abstract:, The current data support the use of high-dose chemotherapy (HDCT) and autologous stem cell transplantation (ASCT) as standard procedure for the majority of patients with Hodgkin's disease (HD) relapsing or progressing after combination chemotherapy. Prognostic factors reflecting unfavourable prognostic features of the disease as well as resistance to conventional salvage therapy have been identified. Preliminary data suggests a high efficacy of high-dose sequential chemotherapies in these patients. An ongoing randomized trial is comparing standard HDCT versus sequential HDCT in patients with relapsed HD. [source] A multivariate analysis of the outcome of endodontic treatmentEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 3 2004Dag Ørstavik In the present study, multivariate analyses were performed on clinical and treatment variables that may influence the outcome of endodontic treatment. Data collected in a previous clinical-radiographic follow-up study were used. Of 810 treated, 675 roots in 498 teeth were followed for 6 months to 4 yr. Of these, 192 (the CAP group) had pre-existing, chronic apical periodontitis and 483 (the NAP group) had not. Root canal treatment followed a standard procedure with one of three sealers chosen at random. Demographic, clinical and radiographic variables were recorded at the start of, and during treatment. The periapical index (PAI) score was used to record the outcome of treatment, and applied in two different endpoint modes (END1 and END2) as the dependent variable for multivariate statistical analyses using logistic regression and the general model. The modes reflected increasing PAI scores (END1) and conventional success/failure assessment (END2). Dropouts were largely similar to the cases followed up. A total of 10 preoperative and peroperative variables were found to be significantly associated with treatment outcome by the multivariate analyses of either the total material or the NAP or CAP subgroups. Several of these were not significant in univariate analyses (e.g. the effect of sealer). Conventional success/failure analyses (END2) identified fewer of the influential variables and had low explanatory power, whereas PAI scores on an ordinal scale (END1) were most sensitive in identifying variables of influence on the treatment outcome. [source] Blocking Fluorine Substitution in Biotransformation of Nortricyclanyl N -Phenylcarbamates with Beauveria bassianaEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 11 2003Günter Haufe Abstract The biotransformation of tricyclo[2.2.1.02,6]hept-3-yl N -phenylcarbamate (8) by a standard procedure using Beauveria bassiana gave a 7:1 mixture of optically active exo,exo - and exo,endo -5-hydroxytricyclo[2.2.1.02,6]hept-3-yl N -phenylcarbamates 15 and 16 in 19% isolated yield. No ring opening of the three-membered ring was observed. Substitution with a fluorine atom at the 5- endo - or 5- exo -position prevented hydroxylation of any alicyclic position of the molecules, p -hydroxylation of the aromatic ring occurring to a small extent instead. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source] TOWARDS A UNIFORM CONCEPT FOR THE COMPARISON AND EXTRAPOLATION OF ROCKWALL RETREAT AND ROCKFALL SUPPLYGEOGRAFISKA ANNALER SERIES A: PHYSICAL GEOGRAPHY, Issue 1 2007MICHAEL KRAUTBLATTER ABSTRACT. Rates of rockwall retreat and rockfall supply are fundamental components of sediment budgets in steep environments. However, the standard procedure of referencing rockwall retreat rates using only lithology is inconsistent with research findings and results in a variability that exceeds three orders of magnitude. The concept proposed in this paper argues that the complexity inherent in rockfall studies can be reduced if the stages of (i) backweathering, (ii) filling and depletion of intermediate storage on the rock face and (iii) final rockfall supply onto the talus slopes are separated as these have different response functions and controlling factors. Backweathering responds to preweathering and weathering conditions whereas the filling and depletion of intermediate storage in the rock face is mainly a function of internal and external triggers. The noise apparent in backweathering rates and rockfall supply can be reduced by integrating the relevant controlling factors in the response functions. Simple conceptual models for the three stages are developed and are linked by a time-dependent ,rockfall delivery rate', which is defined as the difference between backweathering and rockfall supply, thus reflecting the specific importance of intermediate storage in the rock face. Existing studies can be characterized according to their ,rockfall delivery ratio', a concept similar to the ,sediment delivery ratio' used in fluvial geomorphology. Their outputs can be qualified as trigger-dependent rockfall supply rates or backweathering rates dependent on (pre-)weathering conditions. It is shown that the existing quantitative backweathering and rockfall supply models implicitly follow the proposed conceptual models and can be accommodated into the uniform model. Suggestions are made for how best to incorporate non-linearities, phase transitions, path dependencies and different timescales into rockfall response functions. [source] Rigorous filtration for protein crystallizationJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 4 2009Naomi E. Chayen Centrifugation or filtration of protein samples through 0.22,µm mesh size filters is standard procedure before setting up trials for crystallization. This note concerns other, mostly unused filters, namely 0.1,µm and 100,000,300,000 molecular weight cut-off filters, which have proved to aid in obtaining single high-quality crystals. It serves to pool together information concerning filtration which has been scattered, and somewhat concealed, in various publications over the years and to add information that has not yet been published. Filtration is relevant to all methods of crystallization for both screening and optimization. [source] Single-crystal structure validation with the program PLATONJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 1 2003A. L. Spek The results of a single-crystal structure determination when in CIF format can now be validated routinely by automatic procedures. In this way, many errors in published papers can be avoided. The validation software generates a set of ALERTS detailing issues to be addressed by the experimenter, author, referee and publication journal. Validation was pioneered by the IUCr journal Acta Crystallographica Section C and is currently standard procedure for structures submitted for publication in all IUCr journals. The implementation of validation procedures by other journals is in progress. This paper describes the concepts of validation and the classes of checks that are carried out by the program PLATON as part of the IUCr checkCIF facility. PLATON validation can be run at any stage of the structure refinement, independent of the structure determination package used, and is recommended for use as a routine tool during or at least at the completion of every structure determination. Two examples are discussed where proper validation procedures could have avoided the publication of incorrect structures that had serious consequences for the chemistry involved. [source] Ward reduction of gastroschisis in a single stage without general anaesthesia may increase the risk of short-term morbidities: Results of a retrospective auditJOURNAL OF PAEDIATRICS AND CHILD HEALTH, Issue 6 2009Shripada C Rao Background: Ward reduction of gastroschisis in a single stage without the need for general inhalational anaesthesia (ward reduction) has been reported by some authors to be effective and safe. We introduced this practice to our neonatal unit 2 years ago. Aim: To compare the short-term outcomes of this new practice with the standard procedure of reduction under general anaesthesia (GA). Methods: Retrospective case series of all infants with gastroschisis between January 2004 and January 2008. Results: Twenty-seven infants were managed with the traditional approach and 11 infants underwent ward reduction without GA. Infants in the ward reduction group had an increased frequency for all the three major adverse events (ischemic necrosis of bowel: 27.3% vs. 3.7%, odds ratio (OR) 10.72, 95% confidence interval (CI): 0.72, 159.6; need for total parenteral nutrition (TPN) more than 60 days: 18% vs. 3.7%, OR 4.13, 95% CI: 0.28, 61.55; and unplanned return to theatre: 27.3% vs. 7.4%, OR 3.88, 95% CI: 0.44, 34.08), although none of these events reached statistical significance. There were no significant differences between the groups for the outcomes of time to reach full feeds, duration of hospital stay and number of days on antibiotics. Conclusions: These results raise concerns over the role of ward reduction of gastroschisis in a single sitting without the use of GA. Randomised trials with appropriate design and sample size are needed before embracing this method as a standard practice. [source] Rapid screening of beta-adrenergic agents and related compounds in human urine for anti-doping purpose using capillary electrophoresis with dynamic coatingJOURNAL OF SEPARATION SCIENCE, JSS, Issue 20 2009Monica Mazzarino Abstract This paper presents a capillary electrophoresis method, developed for the detection, in human urine, of beta-adrenergic agents and phenolalkylamines. The electrophoretic separation is achieved in less than 10 min and is based on the use of CEofix kit, for the dynamic capillary coating. The effects of accelerator buffer pH and separation voltage were investigated. The optimum buffer pH was found to be 2.5 for beta2-agonists and 6.2 for beta-blockers and phenoalkylamines with a separation voltage of 15 kV. Urine samples spiked with the compounds here studied were treated according to the standard procedure (SPE and evaporation to dryness) and analyzed by CE interfaced with an UV diode-array, set at 195 and 210 nm. The quantitative validation results, obtained analyzing samples at three different concentrations, show a good precision of peak areas that do not exceed 5% for intra-day assays and 10% for inter-day assays. Good linearity (r2 > 0.995) was obtained within the 50,500 ng/mL concentration range. The qualitative validation data show a relative migration times (MTs) variation lower than 1%. The analytes were clearly distinguishable in urine, with LOD and LOQ in the range of 10,80 and 40,100 ng/mL, respectively. [source] Percutaneous liver biopsy in clinical practiceLIVER INTERNATIONAL, Issue 9 2007Bandar Al Knawy Abstract Percutaneous liver biopsy (PLB) is the standard procedure for obtaining hepatic tissue for histopathological examination, and remains an essential tool in the diagnosis and management of parenchymal liver diseases. The use of liver biopsy (LB) is increasing with the advent of liver transplantation and the progress being made in antiviral therapeutic agents. While blind percutaneous needle biopsy is the traditional technique, the use of ultrasound (US) guidance has increased considerably. Literatures were reviewed to assess the existing clinical practice of PLB with an emphasis on the technique, the operator, types of biopsy needles, quality of LB specimens and the risk of complications. The best available evidence indicates that the use of ultrasound-guided biopsy (UGB) is superior to blind needle biopsy (BNB). The odds ratios of the controlled studies showed that BNB carried a higher risk for major complications, postbiopsy pain and biopsy failure. Therefore, percutaneous LB under US control is superior to BNB and it is recommended that UGB be considered the standard of care for this important and widely used invasive procedure in the field of clinical hepatology. [source] Technique and outcome of autologous portal Y-graft interposition for anomalous right portal veins in living donor liver transplantationLIVER TRANSPLANTATION, Issue 4 2009Shin Hwang This study was intended to describe in detail the surgical technique and long-term outcome of autologous portal vein (PV) Y-graft interposition for adult living donor liver transplantation (LDLT). We assessed the outcome of 841 patients who underwent right lobe LDLT from January 2002 to December 2007 with respect to the reconstruction of double-graft PVs. PV anatomy of the donor livers was classified as type I in 796 patients (94.6%), type II in 15 patients (1.8%), and type III in 30 patients (3.6%). Seven type II grafts and all type III PV grafts had double PV orifices. Autologous PV Y-graft interposition was used in 31 patients, and complications occurred in only 1 patient during a median follow-up of 27 months. Overall, the 1- and 3-year graft survival rates were 87.5% and 80.6%, respectively. Use of a Y-graft was not a risk factor for biliary complications, but the liver anatomy of anomalous PV per se seems to be associated with a higher occurrence of biliary complications, especially during the early posttransplant period. The favorable outcome and technical feasibility of autologous portal Y-graft interposition imply that this technique could be the standard procedure for reconstruction of right lobe grafts with double PV orifices. Liver Transpl 15:427,434, 2009. © 2009 AASLD. [source] Detecting dyads of related individuals in large collections of DNA-profiles by controlling the false discovery rateMOLECULAR ECOLOGY RESOURCES, Issue 4 2010H. J. SKAUG Abstract The search for pairs (dyads) of related individuals in large databases of DNA-profiles has become an increasingly important inference tool in ecology. However, the many, partly dependent, pairwise comparisons introduce statistical issues. We show that the false discovery rate (FDR) procedure is well suited to control for the proportion of false positives, i.e. dyads consisting of unrelated individuals, which under normal circumstances would have been labelled as related individuals. We verify the behaviour of the standard FDR procedure by simulation, demonstrating that the FDR procedure works satisfactory in spite of the many dependent pairwise comparisons involved in an exhaustive database screening. A computer program that implements this method is available online. In addition, we propose to implement a second stage in the procedure, in which additional independent genetic markers are used to identify the false positives. We demonstrate the application of the approach in an analysis of a DNA database consisting of 3300 individual minke whales (Balaenoptera acutorostrata) each typed at ten microsatellite loci. Applying the standard procedure with an FDR of 50% led to the identification of 74 putative dyads of 1st- or 2nd-order relatives. However, introducing the second step, which involved additional genotypes at 15 microsatellite loci, revealed that only 21 of the putative dyads can be claimed with high certainty to be true dyads. [source] Transients from initial conditions in cosmological simulationsMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 1 2006Martín Crocce ABSTRACT We study the impact of setting initial conditions in numerical simulations using the standard procedure based on the Zel'dovich approximation (ZA). As it is well known from the perturbation theory, ZA initial conditions have incorrect second- and higher-order growth and therefore excite long-lived transients in the evolution of the statistical properties of density and velocity fields. We also study the improvement brought by using more accurate initial conditions based on second-order Lagrangian perturbation theory (2LPT). We show that 2LPT initial conditions reduce transients significantly and thus are much more appropriate for numerical simulations devoted to precision cosmology. Using controlled numerical experiments with ZA and 2LPT initial conditions, we show that simulations started at redshift zi= 49 using the ZA underestimate the power spectrum in the non-linear regime by about 2, 4 and 8 per cent at z= 0, 1, and 3, respectively, whereas the mass function of dark matter haloes is underestimated by 5 per cent at m= 1015 M, h,1 (z= 0) and 10 per cent at m= 2 × 1014 M, h,1 (z= 1). The clustering of haloes is also affected to the few per cent level at z= 0. These systematics effects are typically larger than statistical uncertainties in recent mass function and power spectrum fitting formulae extracted from numerical simulations. At large scales, the measured transients in higher-order correlations can be understood from first principle calculations based on perturbation theory. [source] Time-Domain and Morphological Analysis of the P-Wave.PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 7 2008Part I: Technical Aspects for Automatic Quantification of P-Wave Features Introduction: Time-domain and morphological analysis of P-wave from surface electrocardiogram has been extensively used to identify patients prone to atrial arrhythmias, especially atrial fibrillation (AF). However, since no standard procedure exists for P-wave preprocessing, standardization of cut-off values for P-wave duration and morphological features is difficult. This study is a methodological investigation of P-wave preprocessing procedures for automatic time-domain and morphological analysis. Methods: We compared, on simulated and real data, the P-wave template obtained applying three alignment algorithms with that obtained without alignment, in terms of template error, shift error, P-wave duration, and morphological parameters. We also proposed automatic algorithms for estimation of P-wave duration. Results: We found that alignment is necessary for a reliable extraction of P-wave template by the averaging procedure, in order to perform time-domain and morphological analysis. On simulated and real data, the error on P-wave duration can be as high as 30 ms on a template obtained without alignment; if alignment procedure is performed, the error on P-wave duration is negligible. Analogously, morphological features are correctly estimated only on a P-wave template obtained with P-waves alignment. We also found that the proposed algorithm for the automatic estimation of the P-wave duration gave reliable results. [source] QRS Amplitude and Shape Variability in MagnetocardiogramsPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 2 2000MARKUS HUCK In magnetocardiography, averaging of QRS complexes is often used to improve the signal-to-noise ratio. However, averaging of QRS complexes ignores the variation in amplitude and shape of the signals caused, for example, by respiration. This may lead to suppression of signal portions within the QRS complexes. Furthermore, for inverse source, reconstructions of dipoles and of current density distributions errors in the special arrangement may occur. To overcome these problems we developed a method for separating and selective averaging QRS complexes with different shapes and amplitudes. The method is based on a spline interpolation of the QRS complex averaged by a standard procedure. This spline function then is fitted to each QRS complex in the raw data by means of nonlinear regression (Levenberg-Marquardt method). Five regression parameters are applied: a linear amplitude scaling, two parameters describing the baseline drift, a time scaling parameter, and a time shift parameter. We found that both amplitude and shape of the QRS complex are influenced by respiration. The baseline shows a weaker influence of the respiration. The regression parameters of two neighboring measurement channels correlate linearly. Thus, selective averaging of a larger number of sensors can be performed simultaneously. [source] Postoperative complications after extracapsular dissection of benign parotid lesions with particular reference to facial nerve functionTHE LARYNGOSCOPE, Issue 3 2010Nils Klintworth MD Abstract Objectives/Hypothesis: The desirable extent of surgical intervention for benign parotid tumors remains a matter of controversy. Superficial or total parotidectomy as a standard procedure is often said to be the gold standard; however, with it the risk of intraoperative damage to the facial nerve cannot be ignored. For some time now, extracapsular dissection without exposure of the main trunk of the facial nerve has been favored as an alternative for the treatment of discrete parotid tumors. Data on the incidence of facial nerve lesions and other acute postoperative complications of extracapsular dissection have been lacking until now. Study Design: Retrospective analysis. Methods: We performed a retrospective analysis of the data from patients in whom extracapsular dissection of a benign parotid tumor had been performed under facial nerve monitoring and as a primary intervention in our department between 2000 and 2008. Results: A total of 934 patients were operated on for a newly diagnosed benign tumor of the parotid gland. Three hundred seventy-seven patients (40%) underwent extracapsular dissection as a primary intervention. The most common postoperative complication was hypoesthesia of the cheek or the earlobe, as reported by 38 patients (10%). Eighteen patients (5%) developed a seroma and 13 patients (3%) a hematoma. A salivary fistula formed in eight patients (2%). Secondary bleeding occurred in three patients (0.8%). In 346 patients (92%) facial nerve function was normal (House-Brackmann grade I) in the immediate postoperative period, whereas 23 patients (6%) showed temporary facial nerve paresis (House-Brackmann grade II or III) and eight patients (2%) developed permanent facial nerve paresis (seven patients House-Brackmann grade II, one patient House-Brackmann grade III). Conclusions: Extracapsular dissection of benign parotid tumors is associated with a low rate of postoperative complications, a fact that is confirmed by the available literature. We therefore recommend that use of this technique always be considered as a means of treating benign parotid tumors as conservatively, that is, as uninvasively, as possible. Laryngoscope, 2010 [source] Optimising the unprotected airway with a prototype Jaw-Thrust-Device , a prospective randomised cross-over studyANAESTHESIA, Issue 11 2009A. Von Goedecke Summary Despite being a standard procedure during induction of anaesthesia, facemask ventilation can be a major challenge especially for inexperienced anaesthetists. We manufactured a Jaw-Thrust-Device designed to keep the patient's jaws in an optimised position, and thus to maintain the airway in a permanently patent state. Using a cross over design, we compared the influence of using the Esmarch manoeuvre (bimanual jaw-thrust), a nasopharyngeal airway, an oropharyngeal airway, or the Jaw-Thrust-Device on airway physiology in 50 healthy adults with body mass index < 35 kg.m,2, undergoing standard facemask ventilation for routine induction of anaesthesia. The main study endpoints were expiratory tidal volumes, airway resistances, and gas flow rates. The Jaw-Thrust-Device was more effective in increasing expiratory tidal volumes and peak inspiratory flow than a standard Esmarch manoeuvre, and was more effective than both nasopharyngeal and oropharyngeal airways in decreasing airway resistance. [source] Reconstruction of seminal ducts in obstructive azoospermiaANDROLOGIA, Issue 4 2001G. Popken Summary. Depending on the localization of the obstruction of the seminal ducts, either a microsurgical reconstruction (tubulovasostomy, vasovasostomy) or a transurethral resection of the ejaculatory ducts is carried out. We have compared the effectiveness and economic advantages of reconstructive microsurgery of the epididymis and vas deferens with standard procedures in animal experiments. Microsurgical invagination techniques in tubulovasostomy are equal to the standard procedure from the point of view of the patency and fertility rates. They are also easier to learn and carry out. Less time is required for the invagination technique, and also less microsurgical suture material. The double-layer technique in vasovasostomy is equal to the one-layer microsurgical technique from the point of view of patency and fertility rates. The one-layer technique requires less time and suture material. It seems that the discrepancy between the patency and the fertility rate is related to immunological processes after reconstruction of the seminal ducts. In cases of obstructive azoospermia it is necessary to investigate the individual conditions and possibilities of the infertile couple. As a result of the high success rate obtainable today by surgical reconstruction of the seminal ducts, this must constitute the first type of treatment to be considered, before any of the procedures of reproductive medicine are undertaken. [source] Surgical strategies in the laparoscopic therapy of cholecystolithiasis and common duct stonesANZ JOURNAL OF SURGERY, Issue 8 2002Kaja Ludwig Background: The purpose of the present study was to examine the current approach and different strategies adopted for laparoscopic cholecystectomy in Germany. Methods: A retrospective survey was conducted at 859 (n = 1200; 67.6%) hospitals in Germany. Data from 123 090 patients who had undergone cholecystectomy were analysed. Results: 71.9% of the operations were finished laparoscopically (n= 88 537) whereas 22.5% were carried out using the open technique. Conversion to open surgery was required in 7.1% of the laparoscopically started operations. When common bile duct stones were diagnosed preoperatively, 74.4% of the participants favoured the primary endoscopic extraction, following laparoscopic cholecystectomy. In cases of intraoperative diagnoses, laparoscopic cholecystectomy was finished and postoperative primary endoscopic extraction was carried out in more than half of the hospitals (58.4%). Sixteen per cent converted to an open operation with simultaneous exploration of the common duct. Laparoscopic desobstruction of the common bile duct was extremely rare (4.4%). Compared with open cholecystectomy, the results show a lower incidence of postoperative reinterventions (0.9 vs 1.8%) and fatal outcomes (0.04 vs 0.53%) for laparoscopic cholecystectomy. In contrast, common bile duct injuries were more frequent in the laparoscopic cholecystectomy group (0.32 vs 0.12%). The median duration of hospitalization was 6.1 days (range: 2.8,12) in the laparoscopic cholecystectomy group compared with 10.4 days (range: 3,28) in the open cholecystectomy group. Conclusions: Laparoscopic cholecystectomy is the standard procedure for the treatment of uncomplicated gallstone disease. There are reasonable differences between the hospitals in type of cholecystectomy for acute cholecystitis, management of common duct stones and intraoperative diagnostics in laparoscopic cholecystectomy, even after adjustment for differences in patient comorbidities. [source] Flat bulk-solvent model: obtaining optimal parametersACTA CRYSTALLOGRAPHICA SECTION D, Issue 9 2002Andrei Fokine A bulk-solvent correction is regularly used for macromolecular refinement. The flat model of the bulk solvent is considered to be the most reliable. It is shown that the standard procedure does not always result in the optimal values of the bulk-solvent correction parameters. A method to obtain the best values for parameters ksol and Bsol of the flat-solvent model is discussed. The values of correctly determined parameters for crystallographic structures deposited in the Protein Data Bank are clustered around ksol = 0.35,e,Å,3 and Bsol = 46,Å2, which have a reasonable physical meaning. Such a distribution allows the use of these mean values of solvent parameters for many practical applications when refined parameters cannot be obtained, especially when an atomic model in the unit cell is not yet known. [source] Adaptive significance of food income in European snakes: body size is related to prey energeticsBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 2 2010MARCO A. L. ZUFFI Feeding strategies and diet patterns have been extensively investigated in vertebrates and, more specifically, in snakes. Although it has been hypothesized that prey species may differ in terms of energy content, almost no theoretical or practical study has been carried out to determine actual nutritional values of the common prey types of wild snakes. Our model taxa were a selection of widely distributed and well known European snake species, which have all been studied in depth: approximately 76% of their diet is composed of mammals, reptiles, and insects. We therefore selected a single model species for each of these categories and proceeded with the analyses. Nutritional values were determined using a standard procedure: lizards and mice were richer in proteins than insects (crickets); insects and mice were richer in lipids than lizards, and mice and crickets have a higher energy content than lizards; lizards were rich in ashes. We then applied our experimental results to a selected sample of European terrestrial snakes (11 populations, ten species, seven genera, two families) characterized by different body size (50,160 cm total length) and reproductive strategies (oviparous versus viviparous), aiming to correlate these parameters with patterns of energy income. A direct relationship was found between body mass/body length ratio (BCI, body condition index) and meal energetics: the higher the BCI, the higher was the metabolic requirement, whereas BCI was independent of species or of reproductive system effect. Large-sized snakes thus need a highly diversified and more energy-rich diet than smaller snakes, supporting previous hypotheses. The simple applicability of this method could be of valuable support in further comparative research work, reducing experimental costs and stimulating further ecological, behavioural, and, possibly, phylogenetic comparisons. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 100, 307,317. [source] Testing Equality between Two Diagnostic Procedures in Paired-Sample Ordinal DataBIOMETRICAL JOURNAL, Issue 6 2004Kung-Jong Lui Abstract When a new diagnostic procedure is developed, it is important to assess whether the diagnostic accuracy of the new procedure is different from that of the standard procedure. For paired-sample ordinal data, this paper develops two test statistics for testing equality of the diagnostic accuracy between two procedures without assuming any parametric models. One is derived on the basis of the probability of correctly identifying the case for a randomly selected pair of a case and a non-case over all possible cutoff points, and the other is derived on the basis of the sensitivity and specificity directly. To illustrate the practical use of the proposed test procedures, this paper includes an example regarding the use of digitized and plain films for screening breast cancer. This paper also applies Monte Carlo simulation to evaluate the finite sample performance of the two statistics developed here and notes that they can perform well in a variety of situations. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] 65 Multi-resistant Escherichia coli septicaemia following transrectal ultrasound guided prostate biopsy , an emerging riskBJU INTERNATIONAL, Issue 2006A.-J. DAVIDSON Introduction:, Transrectal ultrasound (TRUS) guided biopsy of the prostate is the standard procedure for diagnosing prostate carcinoma. Complications range from discomfort and bleeding to asymptomatic bacteruria and sepsis. Rarely, sepsis is fatal. E. coli is the most common pathogen causing infection and although no international standard for the use of prophylactic antibiotics exists their use has decreased the incidence of infection to around 2%. Worldwide the incidence of multi-resistant E. coli (MREC) is increasing, and we report two cases of septicaemia secondary to MREC infection postprostate biopsy. Methods:, We performed a review of case records involving postprostate biopsy MREC infection. A comprehensive literature review of TRUS guided biopsy of the prostate was also performed. Results:, All patients in our series had MREC cultured following TRUS guided biopsy of the prostate. All received the same prophylactic antibiotic regime (norfloxacin and gentamicin). They required admission to hospital for intravenous antibiotics and in two cases inotropic support, eventually making full recoveries. All had a history of recent travel to a developing country whilst two had self-limiting diarrhoea and this is the first report in the English literature of MREC following prostate biopsy. Other risk factors for acquiring multi-resistant urinary tract infections have been identified including age and previous quinolone therapy. Conclusion:, Antibiotic prophylaxis for biopsy of the prostate, being predominantly quinolones, will continue to aid in reducing morbidity. However, with the prevalence of MREC increasing current regimens will not cover such organisms potentially leading to sepsis. In our cases travel to developing countries appeared to be a risk factor for being colonised with MREC. We believe through careful history risk factors for multi-resistant urinary tract infection including travel may alert doctors to the potential risk of MREC at the time of biopsy leading to the addition of a broader spectrum antibiotic such as intravenous meropenem. [source] Outcome of pylorus-preserving gastrectomy for early gastric cancerBRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 9 2008S. Morita Background: Pylorus-preserving gastrectomy has been introduced as a function-preserving operation for early gastric cancer in Japan. The aim of this study was to investigate the safety and radicality of the procedure. Methods: Between 1995 and 2004, 611 patients with apparent early gastric cancer in the middle third of the stomach had pylorus-preserving gastrectomy. The short-term surgical and long-term oncological outcomes of these operations were assessed. Results: The accuracy of preoperative diagnosis of early gastric cancer was 94·3 per cent. Nodal involvement was seen in 62 patients (10·1 per cent). There were no postoperative deaths. Complications developed in 102 patients (16·7 per cent). Major complications, such as leakage and abscess, were observed in 19 (3·1 per cent). The most common complication was gastric stasis, occurring in 49 (8·0 per cent). The overall 5-year survival rate in patients with early gastric cancer was 96·3 per cent. Conclusion: Pylorus-preserving gastrectomy is a safe operation with an excellent prognosis in patients with early gastric cancer. It is recommended as the standard procedure for early gastric cancer in the middle third of the stomach. Copyright © 2008 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. [source] | |||||||||||||||||||||||||||||||||||||||||||