15 research outputs found

    Management of Post Endodontic Retreatment Pain With Low Level Laser Therapy

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    Introduction: Pharmacotherapy with analgesics and non-steroidal anti-inflammatory drugs has been traditionally used to relief post-operative pain of endodontic treatments. However, due to the side effects reported for these drugs, some efforts have been made to decrease the post-operative pain of the endodontic treatments through laser irradiation. The present study aimed to evaluate the effects of low level laser therapy (LLLT) on the reduction of pain after root canal retreatment.Methods: In this clinical trial, 61 patients requiring endodontic retreatments in posterior teeth were selected. A single visit endodontic retreatment was performed. After biomechanical preparation, low level laser was irradiated to the buccal and lingual mucosa overlying the apices of the target tooth in the experimental group. In the control group patients received placebo laser to eliminate the probable psychological effects of laser. Laser irradiation was done with a single dose of 808 nm wavelength (Whitening Lase II- Laser DMC, Samsung, Korea) with 100 mW power, and dose of 70 J/cm2 for 80 seconds. Pain severity was recorded before, immediately after and 4, 8, 12, 24 and 48 hours after the treatment by visual analogue scale (VAS). The pain scores were statistically analyzed by chi-square test between 2 groups. The effects of different variables on the post-operative pain experience were also studied by means of Logistic regression.Results: Pain scores decreased significantly through time until 48 hours after treatment. No significant differences were observed between the 2 modalities regarding pain scores at any time. According to regression analysis, pain severity scores were lower in the laser-irradiated specimens than control groups (OR = 5.69); however, this difference was not statistically significant. Consumption of analgesics after the treatment had significant effect in decreasing post-operative pain experience (OR = 56) while factors of age, gender, laser irradiation, pre-treatment pain scores and education level did not.Conclusion: Low level laser irradiation had limited effects to decrease pain associated with the endodontic retreatments in the first and second molars; however, more studies are required to assess the effects of different parameters of low level laser in this regard

    Highly sensitive C-reactive protein levels in Iranian patients with pulmonary complication of sulfur mustard poisoning and its correlation with severity of airway diseases

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    Background: Sulfur mustard (SM) is a chemical warfare agent that can cause serious pulmonary complications. This study was designed to determine serum highly sensitive C-reactive protein (hs-CRP) and evaluate its correlation with lung function parameters in patients with chronic obstructive pulmonary disease (COPD) due to SM poisoning. Methods: Fifty consecutive SM patients with stable COPD and a mean age 46.3 + 9.18 years were enrolled in this cross sectional study. Thirty healthymen were selected as controls. Lung function parameters were evaluated. Serum hs-CRP by immunoturbidometry assay was measured in both the patients and controls. Results: In the case group, the mean forced expiratory volume in one second (FEV1) was 2.14 + 0.76 L (58.98%+17.51% predicted). The mean serum hs-CRP was 9.4+6.78 SD and 3.9+1.92 SDmg/L in the cases and controls, respectively, with significant statistical differences (p < .001). There was negative correlation between the serum hs-CRP and FEV1 levels (p ¼ .01). The serum hs-CRP levels were also correlated with Global Initiative for ChronicObstructive Lung disease (GOLD) stages (r ¼ .45, p < .001). Conclusions:Our findings suggest that the serum hs-CRP level is increased in SM patients with COPD and may have a direct correlation with disease severity. It may then be used as a marker for the severity of COPD in patients with SM poisoning

    Bilateral Pulmonary Artery, Inferior Vena Cava, and Cardiac Echinococcosis: A Rare Presentation of Zoonotic Diseases

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    Introduction:Cystic hydatidosis is a zoonoticdisease thatis mostly observedin the Mediterranean region. This infectious disease may present throughdifferent manifestations that may delay the diagnosis and cause various complications for the patients. Most of the cases are usually diagnosed by imaging studies and the related management could be medical or surgical depending on the patient’s clinical condition and disease severity. Case presentation:In the present report, we present the case ofa 50-year-old female patient with a positive history of liver and splenichydatid cysts with hemoptysis and dyspnea. The diagnosis of pulmonary and cardiac involvement wasmade usingcomputed tomography angiography. Despite the immediate surgery, the patient died from hemorrhage after 3 days. Conclusion:Themanagement of pulmonary embolism due to Echinococcus highly depends on the clinical judgment and the outcomes are subject to the history and extent of the involvement

    Quantitative 4D seismic imaging in complex media using 2D full-waveform inversion

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    Le suivi temporel est un processus d’acquisition et d’analyse d’acquisitions multiples répétées au même endroit sur la même cible à différentes périodes de temps. Cela s’applique bien à l’exploration sismique quand les propriétés de la cible varient au cours du temps comme pour les réservoirs pétroliers. Cette technique de sismique, dite 4D en raison de l’intégration du temps dans la construction des images, permet une détection et une estimation des variations du sous-sol survenues lors de l’évolution en temps du milieu. En particulier, dans l’industrie, le suivi et la surveillance peuvent améliorer notre compréhension d’un réservoir de pétrole/gaz ou d’un site de stockage de CO2. Analyser la sismique 4D peut aider à mieux gérer les programmes de production des réservoirs. Ainsi, des acquisitions répétées permettent de suivre l’évolutiondes fronts de fluide injectés: on peut optimiser les programmes d’injection de fluides pour une récupération améliorée des hydrocarbures (enhanced oil recovery). Plusieurs méthodes ont été développées pour l’imagerie variable dans le temps en utilisant les informations des ondes sismiques. Dans ma thèse, je montre que l’inversion de forme d’onde complété (FWI) peut être utilisée pour cette imagerie. Cette m´méthode offre des images sismiques quantitatives haute résolution. Elle est une technique prometteuse pour reconstruire les petites variations de propriétés physiques macro-échelle du sous-sol. Sur une cible identifiée pour ces imageries 4D, plusieurs informations a priori sont souvent disponibles et peuvent être utilisées pour augmenter la résolution de l’image. J’ai introduit ces informations grâce à la définition d’un modèle a priori dans une approche classique FWI en l’accompagnant de la construction d’un modèle d’incertitudes a priori. On peut réaliser deux reconstructions indépendantes et faire la différence les reconstruits: on parle de différence parallèle. On peut aussi effectuer une différence séquentielle o`u l’inversion de l’ensemble de données de la second acquisition, dite moniteur, se fait `a partir du modèle de base et non plus à partir du modèle utilisé initialement. Enfin, l’approche double-différence conduit à l’inversion des différences entre les deux jeux de données que l’on rajoute aux données synthétiques du modèle de base reconstruit. J’étudie quelle stratégie est à adopter pour obtenir des changements vitesse plus précis et plus robustes. En plus, je propose une imagerie 4D ciblée en construisant un modèle d’incertitude a priori grâce `a une information (si elle existe) sur la localisation potentielle des variations attendues. Il est démontré que l’inversion 4D ciblée empêche l’apparition d’artéfacts en dehors des zones cibles: on évite la contamination des zones extérieures qui pourrait compromettre la reconstruction des changements 4D réels. Une étude de sensibilité, concernant l’échantillonnage en fréquence pour cette imagerie 4D, montre qu’il est nécessaire de faire agir simultanément un grand nombre de fréquences au cours d’un cycle d’inversion. Ce faisant, l’inversion fournit un modèle de base plus précis que l’approche temporelle, ainsi qu’un modèle des variations 4D plus robuste avec moins d’artéfacts. Toutefois, la FWI effectuée dans le domaine temporel semble être une approche plus intéressante pour l’imagerie 4D. Enfin, l’approche d’inversion 4D régularisée avec un modèle a priori est appliquée sur des ensembles de données réelles d’acquisitions sismiques répétées fournis par TOTAL. Cette reconstruction des variations locales s’inscrit dans un projet d’injection de vapeur pour améliorer la récupération des hydro-carbures: Il est possible de reconstituer des variations de vitesse fines causées par la vapeur injectée.Time-lapse monitoring is the process of acquiring and analysing multiple seismic surveys, repeatedat the same place at different time periods. This seismic technique, called 4D becauseof the integration time in the construction of images, allows detection and estimation of thesubsurface parameter variations occured through a time evolution. Particularly, in industries,the monitoring can improve our understanding of a producing oil/gas reservoir and CO2 storagesite. Analyzing the time-lapse seismics can help to better manage production programsof reservoirs. In addition, repeated surveys can monitor the evolution of injected fluid frontsand can permit to optimize injection programs which are considered for enhanced oil recovery(EOR) techniques.Several methods have been developed for time-lapse imaging using seismic wave information.In my thesis, I show that full waveform inversion (FWI) can be used for time-lapseimaging, since this method delivers high-resolution quantitative seismic images. It is a promisingtechnique to recover small variations of macro-scale physical properties of the subsurface.In time-lapse applications, several sources of prior information are often available and shouldbe used to increase the image reliability and its resolution. I have introduced this informationthrough a definition of a prior model in a classical FWI approach by also considering a prioruncertainty model. In addition, I have suggested a dynamic weighting to reduce the importanceof these prior models in the final convergence. In realistic synthetic cases, I have shownhow the prior model can reduce the sensitivity of FWI to a less accurate initial model. It istherefore possible to obtain a highly accurate baseline model for 4D imaging.Once the baseline reconstruction is achieved, several strategies can be used to assess thephysical parameter changes. We can make two independent reconstructions of baseline andmonitor models and make subtraction of the two reconstructed models. This strategy is calledparallel difference. The sequential difference strategy inverts the monitor dataset starting fromthe recovered baseline model, and not from the model used initially. Finally, the doubledifferencestrategy inverts the difference data between two datasets which are added to thecalculated baseline data computed in the recovered baseline model. I investigate which strategyshould be adopted to get more robust and more accurate time-lapse velocity changes. Inaddition, I propose a target-oriented time-lapse imaging using regularized FWI including priormodel and model weighting, if the prior information exists on the location of expected variations.It is shown that the target-oriented inversion prevents the occurrence of artifacts outsidethe target areas, which could contaminate and compromise the reconstruction of the effectivetime-lapse changes.A sensitivity study, concerning several frequency decimations for time-lapse imaging, showsthat the frequency-domain FWI requires a large number of frequencies inverting simultaneously.By doing so, the inversion provides a more precise baseline model and more robust time-lapsevariation model with less artifacts. However, the FWI performed in the time domain appearsto be a more interesting approach for time-lapse imaging considering all frequency content.Finally, the regularized time-lapse FWI with prior model is applied to the real field timelapsedatasets provided by TOTAL. The reconstruction of local variations is part of a steaminjection project to improve the recovery of hydrocarbons: it is possible to reconstruct thevelocity variations caused by the injected steam

    Imagerie sismique 4D quantitative en milieux complexes par l'inversion 2D de forme d'onde complète

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    Time-lapse monitoring is the process of acquiring and analysing multiple seismic surveys, repeatedat the same place at different time periods. This seismic technique, called 4D becauseof the integration time in the construction of images, allows detection and estimation of thesubsurface parameter variations occured through a time evolution. Particularly, in industries,the monitoring can improve our understanding of a producing oil/gas reservoir and CO2 storagesite. Analyzing the time-lapse seismics can help to better manage production programsof reservoirs. In addition, repeated surveys can monitor the evolution of injected fluid frontsand can permit to optimize injection programs which are considered for enhanced oil recovery(EOR) techniques.Several methods have been developed for time-lapse imaging using seismic wave information.In my thesis, I show that full waveform inversion (FWI) can be used for time-lapseimaging, since this method delivers high-resolution quantitative seismic images. It is a promisingtechnique to recover small variations of macro-scale physical properties of the subsurface.In time-lapse applications, several sources of prior information are often available and shouldbe used to increase the image reliability and its resolution. I have introduced this informationthrough a definition of a prior model in a classical FWI approach by also considering a prioruncertainty model. In addition, I have suggested a dynamic weighting to reduce the importanceof these prior models in the final convergence. In realistic synthetic cases, I have shownhow the prior model can reduce the sensitivity of FWI to a less accurate initial model. It istherefore possible to obtain a highly accurate baseline model for 4D imaging.Once the baseline reconstruction is achieved, several strategies can be used to assess thephysical parameter changes. We can make two independent reconstructions of baseline andmonitor models and make subtraction of the two reconstructed models. This strategy is calledparallel difference. The sequential difference strategy inverts the monitor dataset starting fromthe recovered baseline model, and not from the model used initially. Finally, the doubledifferencestrategy inverts the difference data between two datasets which are added to thecalculated baseline data computed in the recovered baseline model. I investigate which strategyshould be adopted to get more robust and more accurate time-lapse velocity changes. Inaddition, I propose a target-oriented time-lapse imaging using regularized FWI including priormodel and model weighting, if the prior information exists on the location of expected variations.It is shown that the target-oriented inversion prevents the occurrence of artifacts outsidethe target areas, which could contaminate and compromise the reconstruction of the effectivetime-lapse changes.A sensitivity study, concerning several frequency decimations for time-lapse imaging, showsthat the frequency-domain FWI requires a large number of frequencies inverting simultaneously.By doing so, the inversion provides a more precise baseline model and more robust time-lapsevariation model with less artifacts. However, the FWI performed in the time domain appearsto be a more interesting approach for time-lapse imaging considering all frequency content.Finally, the regularized time-lapse FWI with prior model is applied to the real field timelapsedatasets provided by TOTAL. The reconstruction of local variations is part of a steaminjection project to improve the recovery of hydrocarbons: it is possible to reconstruct thevelocity variations caused by the injected steam.Le suivi temporel est un processus d’acquisition et d’analyse d’acquisitions multiples répétées au même endroit sur la même cible à différentes périodes de temps. Cela s’applique bien à l’exploration sismique quand les propriétés de la cible varient au cours du temps comme pour les réservoirs pétroliers. Cette technique de sismique, dite 4D en raison de l’intégration du temps dans la construction des images, permet une détection et une estimation des variations du sous-sol survenues lors de l’évolution en temps du milieu. En particulier, dans l’industrie, le suivi et la surveillance peuvent améliorer notre compréhension d’un réservoir de pétrole/gaz ou d’un site de stockage de CO2. Analyser la sismique 4D peut aider à mieux gérer les programmes de production des réservoirs. Ainsi, des acquisitions répétées permettent de suivre l’évolutiondes fronts de fluide injectés: on peut optimiser les programmes d’injection de fluides pour une récupération améliorée des hydrocarbures (enhanced oil recovery). Plusieurs méthodes ont été développées pour l’imagerie variable dans le temps en utilisant les informations des ondes sismiques. Dans ma thèse, je montre que l’inversion de forme d’onde complété (FWI) peut être utilisée pour cette imagerie. Cette m´méthode offre des images sismiques quantitatives haute résolution. Elle est une technique prometteuse pour reconstruire les petites variations de propriétés physiques macro-échelle du sous-sol. Sur une cible identifiée pour ces imageries 4D, plusieurs informations a priori sont souvent disponibles et peuvent être utilisées pour augmenter la résolution de l’image. J’ai introduit ces informations grâce à la définition d’un modèle a priori dans une approche classique FWI en l’accompagnant de la construction d’un modèle d’incertitudes a priori. On peut réaliser deux reconstructions indépendantes et faire la différence les reconstruits: on parle de différence parallèle. On peut aussi effectuer une différence séquentielle o`u l’inversion de l’ensemble de données de la second acquisition, dite moniteur, se fait `a partir du modèle de base et non plus à partir du modèle utilisé initialement. Enfin, l’approche double-différence conduit à l’inversion des différences entre les deux jeux de données que l’on rajoute aux données synthétiques du modèle de base reconstruit. J’étudie quelle stratégie est à adopter pour obtenir des changements vitesse plus précis et plus robustes. En plus, je propose une imagerie 4D ciblée en construisant un modèle d’incertitude a priori grâce `a une information (si elle existe) sur la localisation potentielle des variations attendues. Il est démontré que l’inversion 4D ciblée empêche l’apparition d’artéfacts en dehors des zones cibles: on évite la contamination des zones extérieures qui pourrait compromettre la reconstruction des changements 4D réels. Une étude de sensibilité, concernant l’échantillonnage en fréquence pour cette imagerie 4D, montre qu’il est nécessaire de faire agir simultanément un grand nombre de fréquences au cours d’un cycle d’inversion. Ce faisant, l’inversion fournit un modèle de base plus précis que l’approche temporelle, ainsi qu’un modèle des variations 4D plus robuste avec moins d’artéfacts. Toutefois, la FWI effectuée dans le domaine temporel semble être une approche plus intéressante pour l’imagerie 4D. Enfin, l’approche d’inversion 4D régularisée avec un modèle a priori est appliquée sur des ensembles de données réelles d’acquisitions sismiques répétées fournis par TOTAL. Cette reconstruction des variations locales s’inscrit dans un projet d’injection de vapeur pour améliorer la récupération des hydro-carbures: Il est possible de reconstituer des variations de vitesse fines causées par la vapeur injectée

    Experimental and numerical investigation of the flow field in the gradual transition of rectangular to trapezoidal open channels

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    Transitions are structures that can change geometry and flow velocity through varying the cross-sections of their channels. Under subcritical flow and steady flow conditions, it is necessary to reduce the flow velocity gradually due to increasing water pressure and adverse pressure gradients. Due to the separation of flow and subsequent eddy formation, a significant energy loss is incurred along the transition. This study presents the results of experimental investigations of the subcritical flow along the expansive transition of rectangular to trapezoidal channels. A numerical simulation was developed using a finite volume of fluid (VOF) method with a Reynolds stress turbulence model. Water surface profiles and velocity distributions of flow through the transition were measured experimentally and compared with the numerical results. A good agreement between the experimental and numerical model results showed that the Reynolds model and VOF method are capable of simulating the hydraulic flow in open channel transitions. Also, the efficiency of the transition and coefficient of energy head loss were calculated. The results show that with an increasing upstream Froude number, the efficiency of the transition and coefficient of energy head loss decrease and increase, respectively. The results also show the ability of numerical simulation to simulate the flow separation zones and secondary current along the transition for different inlet discharges

    Free Radical Scavenging Potential and Essential Oil Composition of the Dorema glabrum Fisch. C.A. Mey Roots from Iran

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    Introduction: Dorema glabrum is an endangered species that grow in Transcaucasia and North West of Iran. The plant has extensive uses e.g. as an herbal remedy or food additive in these regions. The chemical composition of hydrodistilled oil of D. glabrum growing in Iran was analyzed by GC-MS for the first time. Methods: The essential oil of air-dried roots was obtained by hydrodistillation using a Clevenger type apparatus. The oil was subjected to GC-MS analysis and its free radical scavenging properties were determined by DPPH method. Results: Thirty four constituents were identified that represented 81.6% of the total oil. The main compounds were delta-Cadinene (12.77%), beta-bisabolene (7.48%), alpha-Fenchyl acetate (6.32%), Copaene (5.68%) and Cubenol (5.42%). The essential oil had weak free radical scavenging properties with the RC50 value of 2.24 mg/mL. Conclusion: Present work is the first report on chemical composition of the essential oil obtained from D. glabrum roots. GC-MS Analysis showed that the oil was rich in sesquiterpenes. It deems that weak free radical scavenging activity of the oil is due to absence of potent antioxidant compounds

    Asthma in Rhinosinusitis: A Survey from Iran

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    Introduction: The coexistence of asthma and chronic rhinosinusitis (CRS) is more common than expected given their individual prevalence in the general population and may affect patient’s quality of life. The aim of this study was to evaluate the prevalence of asthma in chronic rhinosinusitis in Mashhad, Northeast Iran.  Materials and Methods: This study was performed in two university hospital from November 2012 for 12 months. In total, 153 patients with chronic rhinosinusitis were enrolled and referred to a particular pulmonologist for asthma evaluation.  Results: The mean age of participants was 40.54±13.11 years, and 41.8% were male. In total, 63.4% of patients had the polypoid form of CRS. The proportion of patients in this study with asthma was 41.8%, compared with a general asthma prevalence in this region of 13.5%.  Conclusion: There is a high prevalence of asthma among patients with CRS, but it often remains undiagnosed. Asthma in CRS patients should be diagnosed and treated in order to improve patient’s quality of life. We recommend an evaluation of the lower airways in all of these patients as well as further studies in this field

    An introduction to full waveform inversion

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    International audienceFull waveform inversion (FWI) is a high-resolution seismic imaging technique that is based on using the entire content of seismic traces for extracting physical parameters of the medium sampled by seismic waves. The widespread strategy of seismic imaging, the single scattering formulation, at the core of FWI, assumes no prior scale in the model description. Each unexplained residual data sample at receivers for one source is assumed to come from any point of the medium, and only the summation over sources and receivers helps in locating medium property anomalies, regardless of what type of phase is involved. This pixel-oriented perturbation leads to the local optimization approach, which is a linearized differential approach based on the Newton equation. For a least-squares misfit function, there are both the gradient vector and Hessian matrix, in addition to approximations that can be considered for the related Newton equation. The forward problem of the wave propagation, used thousands of times during optimization, should be efficient, and these equations are expressed either as a first-order hyperbolic system of velocity-stress or as a second-order hyperbolic system of displacement (or velocity) only, by using a self-adjoint formulation in both cases. Gradient vectors are built as a zero-lag crosscorrelation in time between incident and adjoint wavefields with forward and backward patterns and also could be used for obtaining Hessian-matrix approximations. Resolution and uncertainties are relevant, although the actual state of the art does not provide meaningful estimation of these quantities: the FWI remains a deterministic approach at this time. An examplary North Sea data set from the Valhall reservoir illustrates the successful story for high-resolution imaging based on data-driven components, with paleorivers stored in sediments, imprints of glaciers in the bedrock, and gas clouds at different scales in the image. Alternative sources of information on the medium, such as sonic logs and geologic interpretation, are illustrated through a model-driven component of the misfit function. Although methods can be used to increase the speed of the workflow, they are quite costly. The multiparameter reconstruction, which is mandatory for elastic FWI, starts to be feasible if one improves the Hessian-matrix influence. Thus, FWI is becoming a mature strategy for high-resolution seismic imaging

    Spirometric Parameters: Hemodialysis Compared to Peritoneal Dialysis

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    Introduction: Renal failure affects the mechanical and the ventilatory function of the lungs. A few studies have evaluated the ventilatory and pulmonary function in dialysis patients. The present study aimed to compare Pulmonary Function Test (PFT) results in patients undergoing Hemodialysis (HD) and Peritoneal Dialysis (PD). Materials and Methods: We conducted a cross-sectional study on 50  patients with hemodialysis (HD) and 50 cases with PD who  underwent PFT in Ghaem and Imam Reza hospitals Mashhad, Iran from November 2010 to July 2012. Spirometric parameters including forced expiratory volume in 1s (FEV1), FEV1/forced vital capacity (FVC), forced expiratory flow 25-75% (FEF) and peak expiratory flow (PEF) were compared between the two groups of patients. Results: Approximately 68% of the HD patients, 66% of the PD patients, and 67% of all the studied cases showed a normal spirometric pattern. Moreover, there were no significant differences between the two groups considering the mean of the aforementioned spirometric parameters(restrictive ,obstructive pattern) (P=0.969). However, an insignificant inverse correlation was observed between the duration of dialysis with FEV1 (r=0.381, P=0.008), FVC (r=-0.298, P=0.04), FEF 25-75% (r=0.43, P=0.003), PEF (r= 0.349, P=0.02) and FEV1/FVC (r=-0.363, P=0.01,) in the HD patients and between the patients’ age with FEV1/FVC (r=0.03, P=0.02) in the PD patients. Conclusion: This study showed no significant difference in pulmonary function in hemo and peritoneal dialysis,so according this result ,both of the dialysis had the same affect on the lung function
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