192 resultados para K-Fold Accuracy


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Measurement of three-dimensional (3D) knee joint angle outside a laboratory is of benefit in clinical examination and therapeutic treatment comparison. Although several motion capture devices exist, there is a need for an ambulatory system that could be used in routine practice. Up-to-date, inertial measurement units (IMUs) have proven to be suitable for unconstrained measurement of knee joint differential orientation. Nevertheless, this differential orientation should be converted into three reliable and clinically interpretable angles. Thus, the aim of this study was to propose a new calibration procedure adapted for the joint coordinate system (JCS), which required only IMUs data. The repeatability of the calibration procedure, as well as the errors in the measurement of 3D knee angle during gait in comparison to a reference system were assessed on eight healthy subjects. The new procedure relying on active and passive movements reported a high repeatability of the mean values (offset<1 degrees) and angular patterns (SD<0.3 degrees and CMC>0.9). In comparison to the reference system, this functional procedure showed high precision (SD<2 degrees and CC>0.75) and moderate accuracy (between 4.0 degrees and 8.1 degrees) for the three knee angle. The combination of the inertial-based system with the functional calibration procedure proposed here resulted in a promising tool for the measurement of 3D knee joint angle. Moreover, this method could be adapted to measure other complex joint, such as ankle or elbow.

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In Arabidopsis thaliana, gene expression level polymorphisms (ELPs) between natural accessions that exhibit simple, single locus inheritance are promising quantitative trait locus (QTL) candidates to explain phenotypic variability. It is assumed that such ELPs overwhelmingly represent regulatory element polymorphisms. However, comprehensive genome-wide analyses linking expression level, regulatory sequence and gene structure variation are missing, preventing definite verification of this assumption. Here, we analyzed ELPs observed between the Eil-0 and Lc-0 accessions. Compared with non-variable controls, 5' regulatory sequence variation in the corresponding genes is indeed increased. However, approximately 42% of all the ELP genes also carry major transcription unit deletions in one parent as revealed by genome tiling arrays, representing a &gt;4-fold enrichment over controls. Within the subset of ELPs with simple inheritance, this proportion is even higher and deletions are generally more severe. Similar results were obtained from analyses of the Bay-0 and Sha accessions, using alternative technical approaches. Collectively, our results suggest that drastic structural changes are a major cause for ELPs with simple inheritance, corroborating experimentally observed indel preponderance in cloned Arabidopsis QTL.

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Platelet-rich plasma (PRP) is a volume of plasma fraction of autologous blood having platelet concentrations above baseline whole-blood values due to processing and concentration. PRP is used in various surgical fields to enhance soft-tissue and bone healing by delivering supra-physiological concentrations of autologous platelets at the site of tissue damage. These preparations may provide a good cellular source of various growth factors and cytokines, and modulate tissue response to injury. Common clinically available materials for blood preparations combined with a two-step centrifugation protocol at 280g each, to ensure cellular component integrity, provided platelet preparations which were concentrated 2-3 fold over total blood values. Costs were shown to be lower than those of other methods which require specific equipment and high-cost disposables, while safety and traceability can be increased. PRP can be used for the treatment of wounds of all types including burns and also of split-thickness skin graft donor sites, which are frequently used in burn management. The procedure can be standardized and is easy to adapt in clinical settings with minimal infrastructure, thus enabling large numbers of patients to benefit from a form of cellular therapy.

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The photodynamic effects of m-tetrahydroxyphenylchlorin (mTHPC) were assessed on human malignant mesothelioma, squamous cell carcinoma and adenocarcinoma xenografts grown in nude mice and were correlated with mTHPC uptake, histology and doubling time of the tumors. Non-thermal laser light was delivered to the tumor as surface radiation 4 days after intraperitoneal administration of 0.1 and 0.3 mg mTHPC/kg body weight, respectively. The extent of tumor necrosis was measured by histomorphometry. The mTHPC concentration in non-irradiated tumors was assessed by high-performance liquid chromatography (HPLC). The tumors were graded according to their doubling time and their vascular architecture as assessed by histology. The 0.1 mg/kg dose of mTHPC resulted in an equal uptake for all 3 tumor types but revealed a larger extent of photosensitized necrosis for adenocarcinoma, which displayed a delicate tumor stroma with numerous small capillary vessels, than for mesothelioma and squamous cell carcinoma, which were both poor in stroma and vessels. The 0.3 mg/kg dose of mTHPC resulted in a 2-fold higher tumor uptake for all 3 tumor types and in a larger extent of necrosis for mesothelioma and squamous cell carcinoma, but not for adenocarcinoma xenografts, compared with the lower drug dose. Our results demonstrate that different tumor xenografts respond differently to mTHPC-PDT for a given drug-light condition. In this setting, the photosensitizing effect was more closely related to the vascular architecture of the tumors than to the sensitizer uptake and doubling time of the different tumors

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PURPOSE OF REVIEW: Na,K-ATPase is an oligomeric protein composed of alpha subunits, beta subunits and FXYD proteins. The catalytic alpha subunit hydrolyzes ATP and transports the cations. Increasing experimental evidence suggest that beta subunits and FXYD proteins essentially contribute to the variable physiological needs of Na,K-ATPase function in different tissues. RECENT FINDINGS: Beta subunits have a crucial role in the structural and functional maturation of Na,K-ATPase and modulate its transport properties. The chaperone function of the beta subunit is essential, for example, in the formation of tight junctions and cell polarity. Recent studies suggest that beta subunits also have inherent functions, which are independent of Na,K-ATPase activity and which may be involved in cell-cell adhesiveness and in suppression of cell motility. As for FXYD proteins, they modulate Na,K-ATPase activity in a tissue-specific way, in some cases in close cooperation with posttranslational modifications such as phosphorylation. SUMMARY: A better understanding of the multiple functional roles of the accessory subunits of Na,K-ATPase is crucial to appraise their influence on physiological processes and their implication in pathophysiological states

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Located at the internal border of the Grand-Saint-Bernard Zone, the diorite and its aureole lie on top of intensively studied Alpine eclogitic units but this pluton, poorly studied yet, has kept locally almost undeformed. The pluton intruded, at similar to 360 Ma, country-rocks mostly composed of dark shales with Na2O > K2O and minor mafic intercalations of tholeiitic basalt affinity. This association is characteristic of the Vanoise (France) basement series, where available age determinations suggest an Early Paleozoic age. Parts of the pluton, and of its hornfels aureole that is evidenced here for the first time, in the Punta Bioula section of Valsavaranche valley (NW-Italy), have been well-preserved from the Alpine deformation. Syn-emplacement hardening, dehydration-induced, probably prevented strain-enhanced Alpine recrystallization. Magmatic rock-types range continuously from subordinate mafic types at SiO2 similar to 48%, of hornblendite with cumulative or appinite affinities, to the main body of quartz diorite to quartz monzonite (SiO2 up to 62%). P-T estimates for the pluton emplacement, based on the abundance of garnet in the hornfelses, using also zircon and apatite saturation thermometry and Al-in-hornblende barometry, suggest T similar to 800-950 degrees C and minimum P in the 0.2-0.5 GPa range, with records of higher pressure conditions (up to 1-2 GPa?) in hornblendite phlogopite-cored amphibole. The high-K, Na > K, calcalkaline geochemistry is in line with a destructive plate-margin setting. Based on major element data and radiogenic isotope signature (epsilon Nd-360 Ma from -1.2 to + 0.9, Sr-87/Sr-86(360 MA) from 0.7054 to 0.7063), the parental magmas are interpreted in terms of deep-seated metabasaltic partial melts with limited contamination from shallower sources, the low radiogenic Nd-content excluding a major contribution from Vanoise tholeiites. There is no other preserved evidence for Variscan magmatism of similar age and composition in the Western Alps, but probable analogs are known in the western and northern parts of French Massif Central. Regarding the Alpine tectonics, not only the age of the pluton and its host-rocks (instead of the Permo-Carboniferous age previously believed), but also its upper mylonitic contact, suggest revisions of the Alpine nappe model. The Cogne diorite allegedly constituted the axial part of the E-verging ``pli en retour [backfold] du Valsavaranche'', a cornerstone of popular Alpine structural models: in fact, the alleged fold limbs, as attested here by field and geochemical data, do not belong to the same unit, and the backfold hypothesis is unfounded. (C) 2012 Elsevier B.V. All rights reserved.

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The information gathered with intravascular ultrasound (IVUS) are of great value in endovascular techniques. The aim of this study was to evaluate the reliability of IVUS when measuring vessel dimensions by comparison with an established reference method. The left carotid artery was exposed in 4 pigs (45-55 kg) and two piezoelectric crystals were sutured on the adventitia in the same cross-sectional plane. The distance between them was measured either by IVUS and by sonomicrometers. The mean distance between the two crystals calculated by the sonomicrometer was 4.7+/-0.4 mm (mean systolic distance was 4.9+/-0.2 mm, mean diastolic distance was 4.6+/-0.1 mm). The mean distance between the two targets calculated by IVUS was 4. 5+/-0.2 mm (mean systolic distance was 4.6+/-0.2 mm and mean diastolic 4.4+/-0.2 mm). Regression analysis of the two series of data shows a R(2)=0.9984. IVUS measurements are an average 5% smaller than sonomicrometer measurements (3.6% up to 8.3%) and the difference is statistically significant ( p <0.05). The underestimation of IVUS measurements will affect the accuracy, and probably the long-term outcome, of endovascular procedures.

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IMPLICATIONS: A new combined ear sensor was tested for accuracy in 20 critically ill children. It provides noninvasive and continuous monitoring of arterial oxygen saturation, arterial carbon dioxide tension, and pulse rate. The sensor proved to be clinically accurate in the tested range.

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RATIONALE AND OBJECTIVES: To systematically review and meta-analyze published data about the diagnostic accuracy of fluorine-18-fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET) and PET/computed tomography (CT) in the differential diagnosis between malignant and benign pleural lesions. METHODS AND MATERIALS: A comprehensive literature search of studies published through June 2013 regarding the diagnostic performance of (18)F-FDG-PET and PET/CT in the differential diagnosis of pleural lesions was carried out. All retrieved studies were reviewed and qualitatively analyzed. Pooled sensitivity, specificity, positive and negative likelihood ratio (LR+ and LR-) and diagnostic odds ratio (DOR) of (18)F-FDG-PET or PET/CT in the differential diagnosis of pleural lesions on a per-patient-based analysis were calculated. The area under the summary receiver operating characteristic curve (AUC) was calculated to measure the accuracy of these methods. Subanalyses considering device used (PET or PET/CT) were performed. RESULTS: Sixteen studies including 745 patients were included in the systematic review. The meta-analysis of 11 selected studies provided the following results: sensitivity 95% (95% confidence interval [95%CI]: 92-97%), specificity 82% (95%CI: 76-88%), LR+ 5.3 (95%CI: 2.4-11.8), LR- 0.09 (95%CI: 0.05-0.14), DOR 74 (95%CI: 34-161). The AUC was 0.95. No significant improvement of the diagnostic accuracy considering PET/CT studies only was found. CONCLUSIONS: (18)F-FDG-PET and PET/CT demonstrated to be accurate diagnostic imaging methods in the differential diagnosis between malignant and benign pleural lesions; nevertheless, possible sources of false-negative and false-positive results should be kept in mind.

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Despite the recent advances in structural analysis of monoclonal antibodies with bottom-up, middle-down, and top-down mass spectrometry (MS), further improvements in analysis accuracy, depth, and speed are needed. The remaining challenges include quantitatively accurate assignment of post-translational modifications, reduction of artifacts introduced during sample preparation, increased sequence coverage per liquid chromatography (LC) MS experiment, and ability to extend the detailed characterization to simple antibody cocktails and more complex antibody mixtures. Here, we evaluate the recently introduced extended bottom-up proteomics (eBUP) approach based on proteolysis with secreted aspartic protease 9, Sap9, for analysis of monoclonal antibodies. Key findings of the Sap9-based proteomics analysis of a single antibody include: (i) extensive antibody sequence coverage with up to 100% for the light chain and up to 99-100% for the heavy chain in a single LC-MS run; (ii) connectivity of complementarity-determining regions (CDRs) via Sap9-produced large proteolytic peptides (3.4 kDa on average) containing up to two CDRs per peptide; (iii) reduced artifact introduction (e. g., deamidation) during proteolysis with Sap9 compared to conventional bottom-up proteomics workflows. The analysis of a mixture of six antibodies via Sap9-based eBUP produced comparable results. Due to the reasons specified above, Sap9-produced proteolytic peptides improve the identification confidence of antibodies from the mixtures compared to conventional bottom-up proteomics dealing with shorter proteolytic peptides.

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The written report (or its electronic counterpart) is the primary mode of communication between the physician interpreting an imaging study and the referring physician. The content of this report not only influences patient management and clinical outcomes but also serves as legal documentation of services provided and can be used to justify medical necessity, billing accuracy, and regulatory compliance. Generating a high-quality PET/CT report is perhaps more challenging than generating a report for other imaging studies because of the complexity of this hybrid imaging modality. This article discusses the essential elements of a concise and complete oncologic (18)F-FDG PET/CT report and illustrates these elements through examples taken from routine clinical practice.

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In vivo dosimetry is a way to verify the radiation dose delivered to the patient in measuring the dose generally during the first fraction of the treatment. It is the only dose delivery control based on a measurement performed during the treatment. In today's radiotherapy practice, the dose delivered to the patient is planned using 3D dose calculation algorithms and volumetric images representing the patient. Due to the high accuracy and precision necessary in radiation treatments, national and international organisations like ICRU and AAPM recommend the use of in vivo dosimetry. It is also mandatory in some countries like France. Various in vivo dosimetry methods have been developed during the past years. These methods are point-, line-, plane- or 3D dose controls. A 3D in vivo dosimetry provides the most information about the dose delivered to the patient, with respect to ID and 2D methods. However, to our knowledge, it is generally not routinely applied to patient treatments yet. The aim of this PhD thesis was to determine whether it is possible to reconstruct the 3D delivered dose using transmitted beam measurements in the context of narrow beams. An iterative dose reconstruction method has been described and implemented. The iterative algorithm includes a simple 3D dose calculation algorithm based on the convolution/superposition principle. The methodology was applied to narrow beams produced by a conventional 6 MV linac. The transmitted dose was measured using an array of ion chambers, as to simulate the linear nature of a tomotherapy detector. We showed that the iterative algorithm converges quickly and reconstructs the dose within a good agreement (at least 3% / 3 mm locally), which is inside the 5% recommended by the ICRU. Moreover it was demonstrated on phantom measurements that the proposed method allows us detecting some set-up errors and interfraction geometry modifications. We also have discussed the limitations of the 3D dose reconstruction for dose delivery error detection. Afterwards, stability tests of the tomotherapy MVCT built-in onboard detector was performed in order to evaluate if such a detector is suitable for 3D in-vivo dosimetry. The detector showed stability on short and long terms comparable to other imaging devices as the EPIDs, also used for in vivo dosimetry. Subsequently, a methodology for the dose reconstruction using the tomotherapy MVCT detector is proposed in the context of static irradiations. This manuscript is composed of two articles and a script providing further information related to this work. In the latter, the first chapter introduces the state-of-the-art of in vivo dosimetry and adaptive radiotherapy, and explains why we are interested in performing 3D dose reconstructions. In chapter 2 a dose calculation algorithm implemented for this work is reviewed with a detailed description of the physical parameters needed for calculating 3D absorbed dose distributions. The tomotherapy MVCT detector used for transit measurements and its characteristics are described in chapter 3. Chapter 4 contains a first article entitled '3D dose reconstruction for narrow beams using ion chamber array measurements', which describes the dose reconstruction method and presents tests of the methodology on phantoms irradiated with 6 MV narrow photon beams. Chapter 5 contains a second article 'Stability of the Helical TomoTherapy HiArt II detector for treatment beam irradiations. A dose reconstruction process specific to the use of the tomotherapy MVCT detector is presented in chapter 6. A discussion and perspectives of the PhD thesis are presented in chapter 7, followed by a conclusion in chapter 8. The tomotherapy treatment device is described in appendix 1 and an overview of 3D conformai- and intensity modulated radiotherapy is presented in appendix 2. - La dosimétrie in vivo est une technique utilisée pour vérifier la dose délivrée au patient en faisant une mesure, généralement pendant la première séance du traitement. Il s'agit de la seule technique de contrôle de la dose délivrée basée sur une mesure réalisée durant l'irradiation du patient. La dose au patient est calculée au moyen d'algorithmes 3D utilisant des images volumétriques du patient. En raison de la haute précision nécessaire lors des traitements de radiothérapie, des organismes nationaux et internationaux tels que l'ICRU et l'AAPM recommandent l'utilisation de la dosimétrie in vivo, qui est devenue obligatoire dans certains pays dont la France. Diverses méthodes de dosimétrie in vivo existent. Elles peuvent être classées en dosimétrie ponctuelle, planaire ou tridimensionnelle. La dosimétrie 3D est celle qui fournit le plus d'information sur la dose délivrée. Cependant, à notre connaissance, elle n'est généralement pas appliquée dans la routine clinique. Le but de cette recherche était de déterminer s'il est possible de reconstruire la dose 3D délivrée en se basant sur des mesures de la dose transmise, dans le contexte des faisceaux étroits. Une méthode itérative de reconstruction de la dose a été décrite et implémentée. L'algorithme itératif contient un algorithme simple basé sur le principe de convolution/superposition pour le calcul de la dose. La dose transmise a été mesurée à l'aide d'une série de chambres à ionisations alignées afin de simuler la nature linéaire du détecteur de la tomothérapie. Nous avons montré que l'algorithme itératif converge rapidement et qu'il permet de reconstruire la dose délivrée avec une bonne précision (au moins 3 % localement / 3 mm). De plus, nous avons démontré que cette méthode permet de détecter certaines erreurs de positionnement du patient, ainsi que des modifications géométriques qui peuvent subvenir entre les séances de traitement. Nous avons discuté les limites de cette méthode pour la détection de certaines erreurs d'irradiation. Par la suite, des tests de stabilité du détecteur MVCT intégré à la tomothérapie ont été effectués, dans le but de déterminer si ce dernier peut être utilisé pour la dosimétrie in vivo. Ce détecteur a démontré une stabilité à court et à long terme comparable à d'autres détecteurs tels que les EPIDs également utilisés pour l'imagerie et la dosimétrie in vivo. Pour finir, une adaptation de la méthode de reconstruction de la dose a été proposée afin de pouvoir l'implémenter sur une installation de tomothérapie. Ce manuscrit est composé de deux articles et d'un script contenant des informations supplémentaires sur ce travail. Dans ce dernier, le premier chapitre introduit l'état de l'art de la dosimétrie in vivo et de la radiothérapie adaptative, et explique pourquoi nous nous intéressons à la reconstruction 3D de la dose délivrée. Dans le chapitre 2, l'algorithme 3D de calcul de dose implémenté pour ce travail est décrit, ainsi que les paramètres physiques principaux nécessaires pour le calcul de dose. Les caractéristiques du détecteur MVCT de la tomothérapie utilisé pour les mesures de transit sont décrites dans le chapitre 3. Le chapitre 4 contient un premier article intitulé '3D dose reconstruction for narrow beams using ion chamber array measurements', qui décrit la méthode de reconstruction et présente des tests de la méthodologie sur des fantômes irradiés avec des faisceaux étroits. Le chapitre 5 contient un second article intitulé 'Stability of the Helical TomoTherapy HiArt II detector for treatment beam irradiations'. Un procédé de reconstruction de la dose spécifique pour l'utilisation du détecteur MVCT de la tomothérapie est présenté au chapitre 6. Une discussion et les perspectives de la thèse de doctorat sont présentées au chapitre 7, suivies par une conclusion au chapitre 8. Le concept de la tomothérapie est exposé dans l'annexe 1. Pour finir, la radiothérapie «informationnelle 3D et la radiothérapie par modulation d'intensité sont présentées dans l'annexe 2.

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The protein topology database KnotProt, http://knotprot.cent.uw.edu.pl/, collects information about protein structures with open polypeptide chains forming knots or slipknots. The knotting complexity of the cataloged proteins is presented in the form of a matrix diagram that shows users the knot type of the entire polypeptide chain and of each of its subchains. The pattern visible in the matrix gives the knotting fingerprint of a given protein and permits users to determine, for example, the minimal length of the knotted regions (knot's core size) or the depth of a knot, i.e. how many amino acids can be removed from either end of the cataloged protein structure before converting it from a knot to a different type of knot. In addition, the database presents extensive information about the biological functions, families and fold types of proteins with non-trivial knotting. As an additional feature, the KnotProt database enables users to submit protein or polymer chains and generate their knotting fingerprints.

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Blood pressure (BP) is a heritable, quantitative trait with intraindividual variability and susceptibility to measurement error. Genetic studies of BP generally use single-visit measurements and thus cannot remove variability occurring over months or years. We leveraged the idea that averaging BP measured across time would improve phenotypic accuracy and thereby increase statistical power to detect genetic associations. We studied systolic BP (SBP), diastolic BP (DBP), mean arterial pressure (MAP), and pulse pressure (PP) averaged over multiple years in 46,629 individuals of European ancestry. We identified 39 trait-variant associations across 19 independent loci (p < 5 × 10(-8)); five associations (in four loci) uniquely identified by our LTA analyses included those of SBP and MAP at 2p23 (rs1275988, near KCNK3), DBP at 2q11.2 (rs7599598, in FER1L5), and PP at 6p21 (rs10948071, near CRIP3) and 7p13 (rs2949837, near IGFBP3). Replication analyses conducted in cohorts with single-visit BP data showed positive replication of associations and a nominal association (p < 0.05). We estimated a 20% gain in statistical power with long-term average (LTA) as compared to single-visit BP association studies. Using LTA analysis, we identified genetic loci influencing BP. LTA might be one way of increasing the power of genetic associations for continuous traits in extant samples for other phenotypes that are measured serially over time.