Academic literature on the topic 'Canal double'
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Journal articles on the topic "Canal double"
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Banik, Shoma, Samir Banik, Mushfiq Hassan Shaikh, Parimol Chandra Mallick, Abdul Gofur, and Manjur E-Mahmud. "Bilateral double mandibular canal - a case report." Update Dental College Journal 2, no. 1 (February 25, 2013): 31–34. http://dx.doi.org/10.3329/updcj.v2i1.13958.
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Objectives: The objective is to draw attention to the anatomical variation of mandibular canal (double mandibular canals). Methods: This case report showing clinical and radiographic findings of a patient who was presented with bilateral double mandibular canals were recorded. Results: Bifid or double mandibular canals can be detected on a panoramic radiograph. More precise information about the course of the canal can be revealed on CBCT scan. Conclusions: The detection of these bifid or double mandibular canals are important because of their clinical implications. Special attention has to be made in the surgical procedures, especially involving the lower jaw.DOI: http://dx.doi.org/10.3329/updcj.v2i1.13958 Update Dent. Coll. j: 2012; 2 (1): 31-34
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Manfron, Ana Paula Tulio, Alessandra Soares Ditzel, Flávia Gasparini Kiatake Fontão, and Luciana Rei Azevedo-Alanis. "Double Retromolar Canal: a Case Report." Journal of Health Sciences 21, no. 5 (December 20, 2019): 474–76. http://dx.doi.org/10.17921/2447-8938.2019v21n5p474-476.
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AbstractThe retromolar canal is an anatomical variation of the mandibular canal. Its neurovascular bundle may extend to areas of the temporalis tendon, and areas of buccinator muscle insertion in the alveolar process at lower third molar region, beside the retromolar fossa. The observation of the retromolar canal in conventional radiographs is limited by the presence of increased bone condensation in the region due to overlapping anatomical structures. The use of three-dimensional imaging techniques, such as cone beam computed tomography can contribute significantly for the treatment planning.Some complications may occur in surgical procedures involving the retromolar area when the retromolar canals are present, such as hemorrhage, failure in anesthesia and injuries to nerve branches. This study reported an unusual case of a double retromolar canal on the left side of the mandible, that led to the change of the treatment planning in a 54-year-old male patient. Furthermore, the clinical and surgical consequences of these findings in oral rehabilitation were discussed. The cone beam computed tomography was an important diagnostic tool in the observation of the presence and the exact location of retromolar canal. Retromolar canals may be detected on a panoramic radiograph. However, more precise information about the anatomical variation can be shown on cross sectional cone beam computed tomography images. Keywords: Anatomic Variation. Mandible. Cone-Beam Computed Tomography. ResumoO canal retromolar é uma variação anatômica do canal da mandíbula. Seu feixe vásculo-nervoso pode se estender para áreas do tendão do músculo temporal, áreas de inserção do músculo bucinador e no processo alveolar na região do terceiro molar inferior, além da fossa retromolar. A observação do canal retromolar em radiografias convencionais é limitada pela presença de condensação óssea com sobreposição de estruturas anatômicas. Devido a esse fato o uso de técnicas de imagem tridimensionais, como a tomografia computadorizada de feixe cônico, contribuem significativamente para o planejamento do tratamento. Algumas complicações podem ocorrer em procedimentos cirúrgicos envolvendo a região retromolar quando o canal retromolar está presente, como hemorragia, falha na anestesia e lesões aos ramos nervosos. Este estudo relatou um caso incomum de canal retromolar duplo, do lado esquerdo da mandíbula, causando alterações no planejamento clínico do tratamento de um paciente do sexo masculino de 54 anos de idade. Além disso, as consequências clínicas e cirúrgicas desses achados na reabilitação bucal foram discutidas. Atomografia computadorizada de feixe cônico apresentou-se como importante ferramenta diagnóstica na observação da presença e localização exata do canal retromolar. Canais retromolares podem ser detectados em uma radiografia panorâmica. No entanto, informações mais precisas sobre esta variação anatômica podem ser mostradas em imagens de tomografia computadorizada de feixe cônico. Palavras-chave: Variação Anatômica. Mandíbula. Tomografia Computadorizada de Feixe Cônico.AbstractThe retromolar canal is an anatomical variation of the mandibular canal. Its neurovascular bundle may extend to areas of the temporalis tendon, and areas of buccinator muscle insertion in the alveolar process at lower third molar region, beside the retromolar fossa. The observation of the retromolar canal in conventional radiographs is limited by the presence of increased bone condensation in the region due to overlapping anatomical structures. The use of three-dimensional imaging techniques, such as cone beam computed tomography can contribute significantly for the treatment planning.Some complications may occur in surgical procedures involving the retromolar area when the retromolar canals are present, such as hemorrhage, failure in anesthesia and injuries to nerve branches. This study reported an unusual case of a double retromolar canal on the left side of the mandible, that led to the change of the treatment planning in a 54-year-old male patient. Furthermore, the clinical and surgical consequences of these findings in oral rehabilitation were discussed. The cone beam computed tomography was an important diagnostic tool in the observation of the presence and the exact location of retromolar canal. Retromolar canals may be detected on a panoramic radiograph. However, more precise information about the anatomical variation can be shown on cross sectional cone beam computed tomography images. Keywords: Anatomic Variation. Mandible. Cone-Beam Computed Tomography. ResumoO canal retromolar é uma variação anatômica do canal da mandíbula. Seu feixe vásculo-nervoso pode se estender para áreas do tendão do músculo temporal, áreas de inserção do músculo bucinador e no processo alveolar na região do terceiro molar inferior, além da fossa retromolar. A observação do canal retromolar em radiografias convencionais é limitada pela presença de condensação óssea com sobreposição de estruturas anatômicas. Devido a esse fato o uso de técnicas de imagem tridimensionais, como a tomografia computadorizada de feixe cônico, contribuem significativamente para o planejamento do tratamento. Algumas complicações podem ocorrer em procedimentos cirúrgicos envolvendo a região retromolar quando o canal retromolar está presente, como hemorragia, falha na anestesia e lesões aos ramos nervosos. Este estudo relatou um caso incomum de canal retromolar duplo, do lado esquerdo da mandíbula, causando alterações no planejamento clínico do tratamento de um paciente do sexo masculino de 54 anos de idade. Além disso, as consequências clínicas e cirúrgicas desses achados na reabilitação bucal foram discutidas. Atomografia computadorizada de feixe cônico apresentou-se como importante ferramenta diagnóstica na observação da presença e localização exata do canal retromolar. Canais retromolares podem ser detectados em uma radiografia panorâmica. No entanto, informações mais precisas sobre esta variação anatômica podem ser mostradas em imagens de tomografia computadorizada de feixe cônico. Palavras-chave: Variação Anatômica. Mandíbula. Tomografia Computadorizada de Feixe Cônico.
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Öztürk, Ayla, Ayşe Tayman, and Anitha Potluri. "Observation of Double Mandibular Canals and Types of Bifid Canals in Dry Skulls." Balkan Journal of Dental Medicine 24, no. 2 (July 1, 2020): 107–12. http://dx.doi.org/10.2478/bjdm-2020-0018.
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SummaryBackground/Aim: The aim of the present study was to assess prevalence and morphologic mandibular canal variations in dry skulls.Material and Methods: Panoramic radiographs were obtained of 57 skulls among the academic collection at the University of Pittsburgh. Orthodontic wire was inserted through the mandibular canal as a reference point at panoramic images for localization of the course of the mandibular canal.Results: Double mandibular canals were present in 2 out of 57 skulls (3,5%); one of them was unilateral the other one was bilateral. Additionally, bifurcation of the mandibular canal and different types of configurations were assessed. In five of the specimens (8,8%) bifid canals were identified. Among them, one case (1,7%) was identified as a forward type. In one case additional canal (1,7%), was detected in the retromolar region, which joined the main canal. Three of the specimens (5,3%) showed accessory canal types. These were the canals that detached from the main canal and proceeded towards the molar teeth roots (dental type). All of these bifid canal types were unilateral.Conclusions: Our results depicted the anatomical variations of the mandibular canal. Dental practitioners should be aware of this underestimated but not a rare occurrence of mandibular canal variations in order to avoid complication during surgical procedures.
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Almohaimede, Amal A., Alanoud A. Alqahtani, Norah M. Alhatlani, Nouf S. Alsaloom, and Shafia A. Alqahtani. "Interpretation of Root Canal Anatomy of Maxillary and Mandibular Permanent Canines in Saudi Subpopulation: A Cone-Beam Computed Tomography (CBCT) Study." International Journal of Dentistry 2021 (February 12, 2021): 1–7. http://dx.doi.org/10.1155/2021/5574512.
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The objective of this investigation was to evaluate the root canal anatomy of permanent canines in a Saudi subpopulation utilizing CBCT. A total of 1328 CBCT images of maxillary (634) and mandibular (694) permanent canines were collected from Saudi patients who visited the College of Dentistry at King Saud University in Riyadh. The images were analyzed for root and canal numbers, canal configuration types, and symmetry between the bilateral canine teeth in each arch. Gender, age, and tooth position were recorded. The Kappa test was used for both inter- and intraexaminer reliabilities. Data were analyzed with the chi-square test at a P value ≤ 0.05 . There were no two-rooted teeth in maxillary canines, and 1.89% had two canals. Double roots and double canals in mandibular canines were found in 2.88% and 9.94% of the teeth, respectively. Type I canal configuration was more common in maxillary canines (97.94%) compared to mandibular canines (92.07%). Maxillary canines showed higher bilateral symmetries of root and canal numbers and canal configuration types (100%, 98.1%, and 97.9%, resp.) compared to mandibular canines (97.1%, 90.1%, and 92.1%, respectively). The majority of maxillary and mandibular canines had a single root with a single canal and type I canal configuration. Mandibular canines are characterized by having more than one root and canal and alterations in root canal configurations compared to maxillary canines.
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Sana, U., I. U. Niazi, R. S. Din, M. Rasheed, I. Haider, and O. Yousaf. "Root. Canal. Morphology. of Mandibular. First. Permanent. Molars. in a Pakistani. Sub-population." Pakistan Journal of Medical and Health Sciences 15, no. 6 (June 30, 2021): 1314–16. http://dx.doi.org/10.53350/pjmhs211561314.
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Aim : To investigate the number and. patterns of. root canals. of mandibular. first. molars.. Methods.: Descriptive observational study to investigate the canal morphology using clearing technique. The duration of the study was one year from 1st February 2020 to 1st February 2021.Non purposive sampling technique was used and 200 mandibular first molar were collected. Data collected was analysed using the SPSS Vr 10. Study variables include Number and pattern of the roots in mandibular teeth. Descriptive statistics were used; frequencies of the root canals and their canal pattern were calculated. Results: In the mesial root, 14 teeth had a one root canal,186 possessed double root canals were observed. Distal root of 160 teeth possessed one canal, 40 teeth possessed two root canals with type 1 pattern mostly observed. Conclusion: Like other populations Pakistani population may have a diverse root canal system in the mandibular molars that ultimately affect endodontic therapy. Keywords: Roots, canals, anatomy, tooth clearing technique, demineralization
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Mukhaimer, Raed Hakam. "Evaluation of Root Canal Configuration of Mandibular First Molars in a Palestinian Population by Using Cone-Beam Computed Tomography: An Ex Vivo Study." International Scholarly Research Notices 2014 (August 13, 2014): 1–7. http://dx.doi.org/10.1155/2014/583621.
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Aim. The purpose of this study was to investigate the number of canals and variations in root canal configuration in the mandibular permanent first molar teeth of a Palestinian population using cone-beam computed tomography (CBCT). Methods. A sample of 320 extracted double-rooted mandibular permanent first molars from Palestinian population was collected for this study and scanned with CBCT scanner. The following observations were made: number of root canals per root and canal configuration in each root based on Vertucci’s classification. Results. Of the 320 mandibular first molars analyzed, 174 (54.4%) had three canals, 132 teeth (41.3%) had four canals, and only four teeth had two canals. The most common canal configuration in the mesial roots was Vertucci type IV (53.8%) followed by type II (38.8%). In the distal roots, the most prevalent canal configuration was Vertucci type I (57.5%) followed by type II ( 22.5%) and type III (10.6%). Conclusion. Our results showed that the number of canals and canal configuration in Palestinian population were consistent with previously reported data. The present study also indicates that CBCT is helpful as a diagnostic tool for the investigation of root canal morphology.
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Kacarska, Marina, and Julija Zivadinovic. "Root anatomy and apical canal morphology of maxillary first premolars." Macedonian Pharmaceutical Bulletin 64, no. 01 (2018): 89–94. http://dx.doi.org/10.33320/maced.pharm.bull.2018.64.01.008.
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Understanding the root anatomy and apical canal morphology of maxillary premolars is a key prerequisite for successful surgical and endodontic treatment. The aim of this study was to assess the root anatomy and apical canal morphology of maxillary first premolars. To achieve the set task, 30 maxillary first premolars were extracted. After thorough rinse visual assessment of root anatomy was made. Each root was transversally sectioned six millimeters from apex with a straight hand piece. The apical samples were decalcificated in 7.5% trichloroacetic acid, transversal sections were made, stored in 10% formalin then dyed in hematoxylin and eosin and numerated from I to VI. Apical canal morphology was evaluated with an optical microscope. Majority of maxillary first premolars had double roots (63.0%; n=19) that were mostly separated (50.0%; n=15) containing a single root canal. Minority had double roots that were fused (13.0%; n=4) with two root canals. Single root with almost equal occurrence of two, as well as variable root canal configuration were found in (30.0%; n=9). A very rare occurrence of maxillary first premolars with three roots (7.0%; n=2) was detected, two vestibular and one palatal, each containing a single canal configuration. Accessory lateral canals were detected in 20% of maxillary first premolars. Transversal communications were detected in maxillary premolars with one root and double fused roots (26.6%; n=8). A single apical foramen was detected in majority of maxillary first premolars (50.0%; n=15). Two apical foramina were detected in (33.4%; n=10), three in (10.0%; n=3) and four in (6.6%; n=2) maxillary premolars. Keywords: maxillary first premolar, root anatomy, apical canal morphology, decalcification, optical microscopy
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Dosemane, Deviprasad, Meera Niranjan Khadilkar, Shreyanshi Gupta, Pooja Nambiar, and Ria Mukherjee. "Double Trouble of Double Fistulae." Biomedicine 41, no. 1 (April 2, 2021): 163–65. http://dx.doi.org/10.51248/.v41i1.556.
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The complications of attico-antral type of Chronic Suppurative Otitis Media (CSOM) are severe due to underlying bone erosion. We describe a case of a 40-year-old lady with attico-antral CSOM and mastoiditis with a postauricular fistula, who underwent modified radical mastoidectomy with excision of the postauricular cutaneous mastoid fistula. Interestingly, another fistula over the dome of lateral semicircular canal was noted intraoperatively.Few reports of occurrence of postauricular mastoid fistula with a labyrinthine fistula have been documented.
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Islam, Mohammad Aminul, Tasnim Wakia, and Md Shamsul Alam. "Root Canal Morphology of Mandibular First Premolars of Bangladeshi Population." Update Dental College Journal 2, no. 2 (June 28, 2013): 3–7. http://dx.doi.org/10.3329/updcj.v2i2.15481.
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Background: The presence of a single root canal in mandibular first premolar cannot be assumed always. The variability in canal morpholohy of root canal includes the number & shape of the canal as well as pathways of the canals. Methods: In this study, 100 mandibular first premolar teeth were evaluated by clearing technique. Collected teeth were cleaned and merged with 5.25% NaOCl for 48 hours. Then the teeth were decalcified with 5% nitric acid for 72 hours followed by dehydrated sequentially with 80-100% alcohol. After dehydration, Indian Ink was injected into the canal through the previously prepared access cavity. Finally the teeth were made transperent by 98% methylsalicylate and examined. Results: Out of 100 mandibular first premolar teeth, 89 were single rooted, 10 with double rooted and only 1 was triple. On evaluation of canal configuration according to Weine classification, mandibular first premolars had 64% type I, 5% type II, 22% type III and 9% type IV. Apical delta was found incase of 8% mandibular first premolar tooth. Conclusion: Based on this study, mandibular first premolar teeth of Bangladeshi population have multiple roots and canals and variable canal configurations. DOI: http://dx.doi.org/10.3329/updcj.v2i2.15481 Update Dent. Coll. j: 2012; 2 (2): 03-07
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Eliades, Apostolos N., Kalliopi H. Manta, and Anastasios T. Tsirlis. "Neurovascular Content of the Mandibular Canal and Its Clinical Relevance: A Literature Review of the Related Anatomical and Radiological Studies." Balkan Journal of Dental Medicine 18, no. 3 (November 1, 2014): 124–32. http://dx.doi.org/10.1515/bjdm-2015-0020.
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SUMMARYIn literature, anatomical variations of the inferior alveolar nerve branches (infratemporal, extraosseous and intraosseous) are reported and their importance in clinical practice is discussed too. The spatial vessels’ position in relationship with the nerve in the mandibular canal was explored, which is of clinical significance in impacted third molar and implant surgery. It is believed that the neurovascular content of the main mandibular canal follows any variations of the mandibular canal i.e. bifid mandibular, retromolar and accessory mental canals. Retrospective studies and case reports reported the presence of multiple foramina on the medial surface of the ramus, near the main mandibular foramen. In some cases, one supplementary mandibular foramen was found to be connected with the lower third molar, which is called “temporal crest canal”. Others found an accessory mandibular foramen that led into a second mandibular canal which joined the main mandibular canal (double) anteriorly. The bony canals contained a terminal branch of the anterior trunk of the mandibular nerve or a branch of inferior alveolar nerve before it entered the mandibular foramen.The aim of the study was to describe and classify anatomical structures of the mandibular canal and posterior foramina of the mandible through an extensive review of the corresponding studies via the PubMed, Scopus and Google Scholar databases.
Dissertations / Theses on the topic "Canal double"
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Tuerke, Florian. "Interaction entre deux cavités opposées dans un canal hydrodynamique." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS078/document.
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Dans ce travail, nous étudions l'écoulement au sein d'un canal symétrique avec une expansion et une contraction soudaines. Cette configuration peut être considérée comme constituée de deux cavités face à face, deux cavités en miroir, que nous dénommons "double cavité". Le sujet est traité expérimentalement, numériquement et analytiquement, en faisant varier la vitesse d'entrée et de la distance entre cavités, mais en restant à des nombres de Reynolds modérés. L'accent est mis sur l'interaction entre les deux couches de cisaillement et sur le mécanisme de rétroaction intracavitaire dans la limite des écoulements incompressibles. Expérimentalement, on mesure la vitesse par Vélocimétrie par Images de Particules non résolue en temps (PIV 2D2C) dans un plan longitudinal permettent de quanti er le champ de vitesse en moyenne temporelle. Par ailleurs, des mesures par Vélocimétrie Laser à effet Doppler (LDV) et des mesures résolues en temps par PIV 2D2C permettent d'accéder à la composition spectrale des fluctuations de vitesse dans la direction de l'écoulement. L'écoulement est caractérisé à partir des séries temporelles, enregistrées dans les couches de cisaillement d'une des deux cavités, pour une large gamme de vitesses d'entrée et des distances entre cavités. Des simulations numériques directes 2D et 3D, permettent d'étudier le mécanisme hydrodynamique de rétroaction intracavitaire, à partir des champs de vitesse complet. Le champ de vorticité issu des simulations numériques 2D montre l'importance de la rotation d'ensemble au sein de la cavité qui transporte les injections de vorticité induites par les oscillations de la couche de mélange conduisant à une structure de type "carrousel" elle-même à l'origine du mécanisme de rétroaction responsable des oscillations auto-entretenues de la couche de cisaillement. La quanti cation des temps caractéristiques de cette rotation permet d'identifier le régime dans lequel se trouve l'écoulement. Une analyse de stabilité en temps seul, ainsi qu'en temps et espace est réalisée pour des écoulements non visqueux, en prenant un écoulement de base unidimensionnel pour chacun des cas: cavité simple ou double. Pour prendre en compte l'extension finie du système, dans le cas de l'analyse de stabilité linéaire spatio-temporel, on ajoute la condition dite de Kulikowskii, qui permet de prendre en compte la réflexion des ondes d'instabilité hydrodynamique aux bornes du domaine de la cavité. Ce mécanisme de rétroaction produit un ensemble discret de fréquences non-harmoniques, dont certaines correspondent effectivement aux données expérimentalesThis work investigates the flow in a symmetric channel with a sudden expansion and contraction, creating two facing cavities, a so called double cavity. Double cavity flow at moderate Reynolds numbers is studied experimentally, numerically and analytically, as the inflow velocity and the distance between the cavities are varied. The focus is put on the interaction of the two shear layers and the intracavitary hydrodynamic feedback in the incompressible limit.Experimentally, standard 2D2C particle image velocimetry (PIV) measurements in a given spanwise plane provide information on the instantaneous and mean velocity flow fields. Laser Doppler velocimetry and time resolved 2D2C PIV measurements reveal the richness of the streamwise fluctuating velocity spectra. The flow is characterized based on times series, recorded in one of the cavity's shear layers, for a wide range of inflow velocities and cavity distances.Two dimensional and three dimensional direct numerical simulations, which give easy access to the entire flow field, are used to study the intracavitary hydrodynamic feedback mechanism. Vorticity fields, obtained from 2D numerical simulations, show the importance of the recirculating intracavitary back flow. Vorticity packages, injected by the oscillating and impinging shear layer at the downstream cavity edge, are advected upstream in the recirculation region, creating a ``carousel-like'' pattern. The interaction of this vortex carousel with the oscillating shear layer is found to be responsible for the self-sustained oscillations observed experimentally in single and double cavity flow. The quantification of three characteristic time scales of the rotation allows to identify in which regime the flow resides.Temporal and spatio-temporal inviscid linear stability analyses are applied to a one dimensional base flow of single and double cavity flows. To account for the finite extent of the system, the spatio-temporal linear stability analysis is conditioned by a so called Kulikowskii condition, which allows the reflection of hydrodynamic instability waves within the cavity domain. This feedback mechanism yields a set of discrete, non-harmonic frequencies, some of which compare well with experimental results
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Retournard, Alain. "Étude et réalisation d'un canal de double résonance adapté aux expériences de RMN multi-impulsionnelles." Nancy 1, 1989. http://www.theses.fr/1989NAN10478.
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Dispositif de double résonance, couvrant la même gamme de fréquence que le canal d'émission principal et présentant la même souplesse d'utilisation quant au contrôle des amplitude, fréquence et phase. Ce dispositif, normalement placé sous contrôle du calculateur, intègre intégralement des séquences d'impulsions préprogrammées, réalisées dans le mode hardware, qui seraient difficilement générées directement par le calculateur. L'ensemble a été conçu de manière à pouvoir être utilisé de façon très souple et de permettre par conséquent la mise en œuvre de toute nouvelle séquence d'impulsions, si compliquée soit-elle
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Zoubir, Amine. "Etude des transferts thermo-convectifs dans un canal semi-ouvert : Application aux façades type double-peau." Thesis, Lyon, INSA, 2014. http://www.theses.fr/2014ISAL0003/document.
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Notre investigation porte sur la simulation numérique des échanges thermo-convectifs dans un canal vertical ouvert à flux imposé. Cette étude rentre dans le cadre des recherches sur le rafraîchissement passif des composants PV intégrés au bâtiment. À cet effet, un code numérique en Différences Finies est utilisé pour résoudre les équations de Navier-Stokes et simuler la convection naturelle dans un canal. Ce problème reste difficile à résoudre parce que l'écriture des conditions aux limites d'entrée et de sortie reste un problème ouvert. Notre travail consiste d'abord en étude des différentes conditions aux limites pour le benchmark numérique AMETH. Les travaux réalisés ont permis de faire un premier choix sur les conditions aux limites. L'étude s'oriente ensuite sur la qualification et la quantification numériques et expérimentales pour deux fluides : l'air (convection-rayonnement) et l'eau (convection pure). Les résultats numériques/expérimentaux ont été comparés et les discordances ont été analysées. Plusieurs aspects phénoménologiques (rayonnement entre surfaces, variation des propriétés thermo-physiques, variation du nombre de Prandtl) ont été abordés afin de caractériser leurs influences respectives sur l'écoulement et le transfert thermique. Enfin, dans le but d'apporter des éléments de réponses sur les conditions aux limites dynamiques, nous avons simulé la convection naturelle d'un canal dans une cavité et tenté une modélisationThe present investigation deals with natural convection flow in a vertical open-ended channel with wall constant heat flux. This study falls under the framework of research on passive cooling of building integrated PV components. For this purpose, a numerical code developed with Finite Differences scheme is used to solve Navier-Stokes equations and simulate the natural convection in a channel. This problem is difficult to solve because the writing of inlet/outlet boundary conditions remains an open problem. First, our work consists of studying different boundary conditions for the the numerical benchmark AMETH. The work carried out has enabled a first choice of boundary conditions. The study then focuses on numerical and experimental quantification and qualification for two fluids : air ( convection - radiation) and water ( pure convection) . Experimental and numerical results were compared and discrepancies were analyzed. Several phenomenological aspects ( surface radiation, thermophysical properties variation, Prandtl number variation ) were discussed in order to characterize their influence on flow and heat transfer. Finally, in order to provide some answers on dynamical boundary conditions, we simulated natural convection of a channel inside a cavity and tried a modeling
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Li, Yiqin. "Approches analytique et expérimentale de la convection naturelle en canal vertical : Application aux double-façades photovoltaïques." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEI002/document.
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Dans le contexte énergétique actuel, le développement de l'énergie solaire passe par son développement à grande échelle en milieu urbain. Les solutions actives et intégrées telles que les double-façades photovoltaïques permettent d'une part d'envisager une valorisation de la chaleur et d'autre part de valoriser l'enveloppe des bâtiments en tant que surface de captation. De plus, cette configuration limite la perte de rendement et l'accélération du vieillissement liées à la surchauffe des cellules. En effet, les composants photovoltaïques sont séparés du bâtiment par une lame d'air et la convection naturelle développée dans cet espace favorise l'évacuation de la chaleur absorbée par les panneaux. Cependant, le comportement global d'une double-façade photovoltaïque est très complexe et encore mal compris. Cette thèse se focalise sur l'expérimentation du phénomène de la convection naturelle. Un banc d'essais, développé dans le cadre de la thèse de Daverat, modélise la double-façade par un canal vertical avec chauffage pariétal. Le fluide d'étude est de l'eau afin de s'affranchir du rayonnement entre parois et d'étudier le couplage conduction-convection. Le banc d'essais est constitué d'un canal vertical de 65cm de haut, chauffé à une densité de flux uniforme, plongé dans une cellule de 1,5m de haut remplie d'eau. L'écoulement est observé par des mesures de densité de flux de chaleur, de température pariétale et de vitesse, ces dernières étant réalisées par vélocimétrie par images de particules et par vélocimétrie laser Doppler. Deux configurations de chauffage sont étudiées : symétrique et asymétrique. Pour l'étude de la configuration avec un chauffage symétrique, les données expérimentales issues du travail de thèse de Daverat sont analysées par une approche zonale. Un découpage du canal est proposé et une analyse des ordres de grandeur permet de comprendre les observations expérimentales. Ainsi, cette analyse se focalise sur le transfert thermique aux parois, l'évolution de la pression dans le canal et sur les fluctuations, en particulier, sur l'évaluation du terme croisé du tenseur de Reynolds. La configuration d'un chauffage asymétrique est étudiée expérimentalement pour la phase de démarrage et le régime stationnaire. Pour la phase de démarrage, la caractérisation des premières heures à partir de la mise en chauffage de la paroi est réalisée en termes de température pariétale, de vitesse et de comportement bi-/tri-dimensionnel de l'écoulement. Un écoulement de retour de grande échelle est mis en évidence. L'impact de la stratification thermique externe du canal est également étudié. Pour le régime stationnaire, les analyses sont réalisées sur des données pour lesquels le régime est considéré établi. Les comportements thermique et dynamique sont étudiés et mettent en évidence deux états distincts. Des écoulements de retour sont également observés. Enfin, les influences du nombre de Prandtl et de l'écartement du canal sont discutéesUnder the current energy context, the development of solar energy goes through its large scale development, especially in urban areas. Active and integrated solutions, such as photovoltaic double-skins, allow both the heat recovery for building needs and the exploitation of building envelope as collecting surface. Furthermore, this configuration limits the efficiency loss and the acceleration of ageing process due to overheating of the solar cells. Indeed, in this configuration, the photovoltaic panels are separated from the building by an air channel and the thermally driven flow that develops in the channel helps to evacuate the heat absorbed by the panels. However, the global behaviour of the photovoltaic double-skin is complex and not yet fully understood. This study is part of a scientific project on multi-scale modelling and experimentation of BIPV components. It focuses on the experimentation of the natural convection phenomenon in double-façades. An experimental apparatus developed during C. Daverat's thesis models the double-façade by a vertical channel with wall heating. The working fluid is water so as to avoid radiative heat transfer between walls. The experimental apparatus consists of a 65 cm high vertical channel, with isoflux heating, immersed in a 1.5 m high water tank. The fluid flow is instrumented with measurements of heat flux, wall temperature and velocity. The velocity measurements are made by Particle Image Velocimetry and Laser Doppler Velocimetry. Two heating configurations are studied: symmetrical (same heat flux is imposed on both walls) and asymmetrical (only one wall is heated, the other one being adiabatic). For the study with symmetrical heating configuration, experimental data from Daverat's thesis are analysed by a zonal approach. The channel is split into several zones and a scaling analysis is conducted in order to explain experimental observations. Thus, the study focuses on heat transfer, pressure evolution in the channel and fluctuations, in particular, the evaluation of the maximum Reynolds stress. The asymmetrical configuration is studied for the transient regime and the steady regime. For the transient regime, early stage (first hours) is characterised in terms of wall temperature, velocity and two- or three-dimensional flow behaviour. A large-scale reversal flow is observed. The impact of external thermal stratification is also studied. For the steady regime, thermal and dynamic behaviours are studied and two different states are distinguished and characterised. Reversal flows are also observed. Finally, the influence of the Prandtl number and the channel width is discussed
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GAGNON, YVES. "Etude numerique d'ecoulements recircules a grand nombre de reynolds par methode des vortex aleatoires : application au canal a expansion simple et au canal a expansion double." Toulouse 3, 1989. http://www.theses.fr/1989TOU30155.
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Ce travail montre la precision et la convergence de la methode des vortex aleatoires (random vortex method) pour la simulation d'ecoulements de fluide recircules a grand nombre de reynolds. Les ecoulements etudies sont instationnaires, bidimensionnels et dans le regime turbulent. La premiere geometrie est un canal a parois paralleles incorporant une expansion brusque sous la forme d'une marche simple; tandis que la deuxieme geometrie est un canal a parois paralleles incorporant une expansion brusque sous la forme d'une marche double symetrique. La methode des vortex aleatoires, une methode lagrangienne et sans grille, resout les equations completes de navier-stokes et l'equation de continuite, avec les conditions aux limites appropriees, en utilisant une formulation dans les variables de vorticite. Afin de valider le modele numerique, nous presentons les resultats numeriques sous forme de champs de vorticite, profils de vitesses, lqignes de courant, champs et profils de pression, statistiques de turbulence, analyses de correlation et analyses frequentielles. Les resultats numeriques sont compares a des resultats experimentaux publies dans la litterature
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CHARLIER, SERGERE LAURENCE. "Fermeture du canal arteriel par catheterisme interventionnel avec une double ombrelle de rashkind : a propos de 25 cas." Clermont-Ferrand 1, 1994. http://www.theses.fr/1994CLF1M011.
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Niescierowicz, Katarzyna. "Développement de la technologie des récepteurs couplés à un canal ionique pour des études structure-fonction des récepteurs couplés aux protéines G et du canal Kir6.2." Phd thesis, Université de Grenoble, 2013. http://tel.archives-ouvertes.fr/tel-01067669.
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Les Récepteurs Couplés à un Canal Ionique (ICCRs) sont des canaux ioniques artificielscréés par fusion d'un Récepteur Couplé aux Protéines G (RCPG) au canal ionique Kir6.2. Dansce concept, le canal agit comme un rapporteur direct des changements conformationnels desRCPGs permettant de détecter par simple mesure de courant, la fixation d'agonistes etd'antagonistes proportionnellement à leur concentration.Le signal induit étant directement corrélé à l'activité du récepteur, indépendamment desvoies de signalisation des protéines G, nous avons exploité cet avantage pour étendre le champd'applications des ICCRs au cours de cette thèse. Nous avons développé quatre applications quisont: 1) la caractérisation fonctionnelle des RCPG optimisés pour la cristallisation par insertionde domaine du lysozyme du phage T4 dans la boucle ICL3; 2) la détection de la dépendance desRCPGs au cholestérol; 3) la détection de ligands dits "biaisés" pour faciliter leur criblage; et 4) lacartographie fonctionnelle des portes du canal Kir6.2 régulées par des protéines membranairesinteragissant par le domaine N-terminal.
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Shchepetov, Andrey. "Étude et fabrication de dispositifs nanométriques pour applications THz." Thesis, Lille 1, 2008. http://www.theses.fr/2008LIL10069/document.
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Les applications émergentes dans la gamme des fréquences Térahertz (THz, 10¹² Hz) stimulent le développement des composants actifs et passifs rapides ainsi que des émetteurs et des détecteurs de radiation travaillant dans ce domaine. Les dispositifs actuels ne répondent pas à tous les besoins de l'industrie à cause de la consommation, la taille et le coût très importants. La solution pour la réalisation des émetteurs et des détecteurs peut venir des transistors à ondes plasma que nous avons étudiés. Ce sont les composant à base de HEMT Ill-V exploitants les nouvelles propriétés de transport électronique. Les mesures de ces dispositifs ont montré les possibilités de l'émission et de la détection de la radiation autour de 1 THz, à température basse et ambiante. Une détection résonante avec une fréquence ajustable est possible. D'un autre côté il est nécessaire de réaliser les composants actifs électroniques (transistors) capables de fonctionner aux fréquences proches du THz. Ceci est nécessaire pour la réalisation des circuits rapides comme les amplificateurs, les mélangeurs et autres. Pour répondre à cette demande, nous avons étudié deux types de transistors double-grilles. Les mesures ont prouvé l'amélioration des performances statiques et dynamiques (saturation de courant de drain et courant de drain maximal, efficacité de commande, transconductance et conductance de sortie, fréquences de fonctionnement). De plus, la consommation aux performances équivalentes est plus faible. Les simulations montrent que les performances peuvent être améliorées d'avantageThe emergent applications in the Terahertz (THz) frequencies range stimulate the development of active and passive rapid devices as much as of emitters and detectors working in this domain. Actually existent devices do not respond to all industry needs because of too high consumption, size and cost, and other inconvenient. A solution for realisation of emitters and detectors could come from plasma-wave transistor that we studied. These devices are based on 1I1-V HEMT and utilised a particular behaviour of electronic transport. Measurements have shown the possibility of emission and detection of radiation at about 1 THz. From the other hand it is necessary to realize electronic active devices (transistors) able to operate near the THz range. This is necessary for realisation of rapid integrated circuits such as amplifiers, mixers and so on. To do this we have chosen to study two kinds of double-gate transistors. Measurements have shown the increasing of static and dynamic performances (maximum drain current and drain current saturation, efficiency of charge control, transconductance, output conductance, operation frequencies). Besides, the same performances can be obtained at lower consumption. Simulations show that performances could be improved even more
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Malbert-Colas, Laurence. "Recherche et identification de partenaires du canal épithélial à sodium ENaC : étude du rôle potentiel de ces partenaires dans la régulation de l'activité de ENaC." Paris 7, 2003. http://www.theses.fr/2003PA077168.
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Doria, Rodrigo Trevisoli. "Operação analógica de transistores de múltiplas portas em função da temperatura." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/3/3140/tde-10012011-135500/.
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Neste trabalho, é apresentada uma análise da operação analógica de transistores de múltiplas portas, avaliando a tensão Early, o ganho de tensão em malha aberta, a razão da transcondutância pela corrente de dreno (gm/IDS), a condutância de dreno e, em especial, a distorção harmônica, exibida por estes dispositivos. Ao longo deste trabalho, foram estudados FinFETs, dispositivos de porta circundante (Gate-All-Around GAA) com estrutura de canal gradual (Graded-Channel GC) e transistores MOS sem junções (Junctionless - JL). Inicialmente, foi efetuada a análise da distorção harmônica apresentada por FinFETs com e sem a presença de tensão mecânica biaxial, com diversas larguras de fin (Wfin) e comprimentos de canal (L), quando estes operavam em saturação, como amplificadores de um único transistor. Nesta análise, as não-linearidades foram avaliadas através da extração das distorções harmônicas de segunda e terceira ordens (HD2 e HD3, respectivamente), mostrando que a presença de tensão mecânica tem pouca influência em HD2, mas altera levemente a HD3. Quando os ganhos de tensão em malha aberta dos dispositivos são levados em conta, transistores sem tensão, também chamados de convencionais, mais estreitos apresentam grande vantagem em termos de HD2 em relação aos tensionados. Ainda nesta análise, percebeu-se que HD2 e HD3 de transistores tensionados pioram com a redução da temperatura, especialmente em inversão mais forte. Na seqüência, foi efetuada uma análise de HD3 em FinFETs com e sem tensão mecânica de vários comprimentos e larguras de canal, operando em região triodo e aplicados a estruturas balanceadas 2-MOS, mostrando que presença de tensão mecânica traz pouca influência em HD3, mas reduz a resistência do canal dos dispositivos (RON), o que não é bom em estruturas resistivas, como as avaliadas. Nesta análise, ainda, pode-se perceber uma melhora em HD3 superior a 30 dB ao se incrementar VGT de zero a 1,0 V, em cuja tensão dispositivos mais estreitos apresentam curvas mais lineares que os mais largos. Então, foi estudada a distorção apresentada por transistores GAA e GC GAA operando em regime triodo, aplicados a estruturas 2-MOS, onde se pôde perceber que GC GAAs com maiores comprimentos da região fracamente dopada apresentam vantagem em HD3 em relação aos demais, para valores de VGT superiores a 2 V. Na avaliação destas estruturas em função da temperatura, percebeu-se que, para VGT superiores a 1,1 V, HD3 depende fortemente da temperatura e piora conforme a temperatura diminui. O estudo envolvendo transistores sem junções foi mais focado em seus parâmetros analógicos, comparando-os aos apresentados por dispositivos de porta tripla ou FinFETs. Em inversões moderada e forte, transistores sem junção apresentaram menores valores para gm/IDS em relação a dispositivos de FinFETs polarizados em um mesmo nível de corrente, entretanto, a dependência de gm/IDS com a temperatura em transistores sem junção também foi menor que a apresentada por FinFETs. JL e FinFETs apresentaram comportamentos distintos para a tensão Early e o ganho de tensão em malha aberta em função da temperatura. Estes parâmetros sempre melhoram com o aumento da temperatura em dispositivos JL, enquanto que exibem seu máximo valor em temperatura ambiente em FinFETs. Nas proximidades da tensão de limiar, transistores sem junção com largura de fin de 30 nm exibiram tensão Early e ganho superiores a 80 V a 57 dB, respectivamente, enquanto que FinFETs mostraram Tensão Early de 35 V e ganho de 50 dB. Em todos os estudos efetuados ao longo do trabalho, procurou-se apontar as causas das não-linearidades apresentadas pelos dispositivos, a partir de modelos analíticos que pudessem relacionar a física de funcionamento dos transistores com os resultados experimentalmente obtidos.In this work it is presented an analysis of the analog operation of multiple gate transistors, evaluating the Early Voltage, the open-loop voltage gain, the transconductance over the drain current ratio (gm/IDS), the drain conductance and, especially, the harmonic distortion exhibited by these devices. Along the work, FinFETs, Gate-All-Around (GAA) devices with the Graded-Channel (GC) structure and MOS transistors without junctions (Junctionless - JL) were studied. Initially, an analysis of the harmonic distortion presented by conventional and biaxially strained FinFETs with several fin widths (Wfin) and channel lengths (L) was performed, when these devices were operating in saturation as single transistor amplifiers. In this analysis, the non-linearities were evaluated through the extraction of the second and the third order harmonic distortions (HD2 and HD3, respectively), and it was shown that the presence of strain has negligible influence in HD2, but slightly changes HD3. When the open loop voltage gain of the devices is taken into consideration, narrower conventional transistors present a huge advantage with respect to the strained ones in terms of HD2. Also, it was perceived that both HD2 and HD3 of strained FinFETs worsen with the temperature decrease, especially in stronger inversion. In the sequence, an analysis of the HD3 presented by conventional and strained FinFETs of several fin widths and channel lengths operating in the triode regime was performed. These devices were applied to 2-MOS balanced structures, showing that the presence of the strain does not influence significantly the HD3, but reduces the resistance in the channel of the transistors (RON), which is not good for resistive structures as the ones evaluated. In this analysis, it can also be observed an HD3 improvement of 30 dB when VGT is increased from zero up to 1,0 V, where narrower devices present transfer characteristics more linear than the wider ones. Then, it was studied the distortion presented by GAA and GC GAA devices operating in the triode regime, applied to 2-MOS structures. In this case, it could be perceived that GC GAAs with longer lightly doped regions present better HD3 in comparison to the other devices for VGT higher than 2.0 V. In the evaluation of these structures as a function of the temperature, it could be seen that for VGT higher than 1.1 V, HD3 strongly depends on the temperature and worsens as the temperature decreases. The study involving JL transistors was focused on their analog parameters, comparing them to the ones presented by triple gate devices or FinFETs. In moderate and strong inversions, Junctionless showed lower values for gm/IDS with respect to triple gate devices biased at a similar current level. However, the dependence of gm/IDS from Junctionless with the temperature was also smaller than the one presented by FinFETs. Junctionless and FinFETs exhibited distinct behaviors for the Early voltage and the open-loop voltage gain as a function of the temperature. These parameters always improve with the temperature raise in JL devices whereas they exhibit their maximum values around room temperatures for FinFETs. In the proximity of the threshold voltage, Junctionless with fin width of 30 nm presented Early voltage and intrinsic gain larger than 80 V and 57 dB, respectively, whereas FinFETs exhibited Early voltage of 35 V and gain of 50 dB. For all the studies performed in this work, the probable causes of the non-linearities were pointed out, from analytic models that could correlate the physical work of the devices with the experimental results.
Books on the topic "Canal double"
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Limited, Compass Maps. Venice Popout Map: Venezia E Il Canal Grande/Venice and the Grand Canal : Double Map (Europe Popout Maps). 4th ed. Compass Maps, 1998.
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de Saint Aubert, Emmanuel. Rereading the Later Merleau-Ponty in the Light of his Unpublished Work. Edited by Dan Zahavi. Oxford University Press, 2018. http://dx.doi.org/10.1093/oxfordhb/9780198755340.013.24.
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Access to a large number of unpublished manuscripts allows us to follow the continuity of Merleau-Ponty’s thought from his first to his last writings, to uncover its double critical constitution, anti-Cartesian and anti-Sartrean, and to understand the status of this philosophy of the flesh as it establishes itself as ontology. This philosophy is geared toward a never-abandoned methodological challenge to grasp humanity first as another manner of being a body, the challenge of thinking a corporeity which is always already, in the very principle of its animation, intercorporeity. Through his continual pursuit of a phenomenology of perception, its insistence on the motifs of depth, the inexhaustible, the invisible, and incompletion, Merleau-Ponty’s carnal ontology proceeds in the discovery of the common negativity of human beings and the world, of myself and others, which affects its conception of being.
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Crouch, Tammy. Carpal Tunnel Syndrome and Repetitive Stress Injuries: The Comprehensive Guide to Prevention, Treatment, and Recovery. Frog, Ltd., 1996.
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Wears, Robert, and Kathleen Sutcliffe. Still Not Safe. Oxford University Press, 2019. http://dx.doi.org/10.1093/oso/9780190271268.001.0001.
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Patient safety suddenly burst into public consciousness in the late 1990s and became a “celebrated” cause in the 2000s. It has since gradually faltered, and little improvement has been noted over almost 20 years. Both the rise and fall of patient safety demand explanation. Medical harm had been known long before the 1990s, so why did it suddenly become popular? And why were safety efforts ineffective? The authors propose that this rise was due to a discursive shift that reframed “medical harm” into “medical error” in the setting of anxiety about industrialization and great change in healthcare. The “error” framing, with its inherent notion of agency, was useful in advancing the agenda of a technocratic, managerial group of health professionals and diminishing the authority of the old guard based on clinical expertise. The fall was due to this “medicalization” of safety. Health professionals and managers with little knowledge of safety science came to dominate the patient safety field, crowding out expertise from the safety sciences (e.g., psychology, engineering) and thus keeping reform under the control of the healthcare establishment. Operating with a sort of delusional clarity, this scientific-bureaucratic cabal generated a great deal of activity but made little progress because they failed to engage with expertise in the safety sciences. Twenty years after sudden popularity, there is general agreement that little of value has been achieved. The future of patient safety is in doubt, and radical reform in approaches to safety will be required for progress to be made.
Book chapters on the topic "Canal double"
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Onchis-Moaca, Darian, Simone Zappalá, Smaranda Laura Goţia, and Pedro Real. "Double Hough Transform for Estimating the Position of the Mandibular Canal in Dental Radiographs." In Applications of Computer Algebra, 317–27. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-56932-1_22.
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Alfieri, O., and B. De Mol. "Correction of Mitral Incompetence in Atrioventricular Canal Defects with Double-Orifice Mitral Valve: The Triple-Orifice Repair." In Cardiac Reconstructions, 25–29. Berlin, Heidelberg: Springer Berlin Heidelberg, 1989. http://dx.doi.org/10.1007/978-3-642-74629-1_5.
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Ginor, Isabella, and Gideon Remez. "The Soviet Regulars Move In." In The Soviet-Israeli War, 1967-1973, 135–50. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780190693480.003.0011.
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The personnel of the Soviet expeditionary force to Egypt was carefully selected, screened (for Jews and other undesirable element) and trained for desert warfare, in parallel with Egyptian crews who were ultimately to take over the weapons. The MiG-21 fighters of interceptor squadrons were transported to Egypt in a new airlift. Meanwhile Israeli air attacks foiled foiled Egyptian attempts to station SAMs along the Suez Canal, and a Soviet-made radar station was lifted by an Israeli heliborne raid, Yet-inconclusive testimonies indicate that a Soviet tank force was landed at Alexandria to protect the “Kavkaz” formations. The Israeli “depth bombings” caused casualties among the Soviet advisers, exacerbating Moscow’s motivation to counter them. The first report from a newly recruited Israeli spy, Ashraf Marwan, established the false version of a secret visit by Nasser to Moscow – the first instance of his actual operation as an Egyptian double agent. Soviet and Egyptian naval units failed to intercept five Israeli missile boats that evaded the French embargo to sail home.
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Kontturi, Katve-Kaisa. "From Double Navel To Particle-Sign: Toward The A-Signifying Work Of Painting." In Carnal Knowledge. I.B.Tauris, 2013. http://dx.doi.org/10.5040/9780755603435.ch-001.
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Kearney, Richard, and Melissa Fitzpatrick. "Carnal Hospitality." In Radical Hospitality, 49–58. Fordham University Press, 2021. http://dx.doi.org/10.5422/fordham/9780823294428.003.0005.
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This chapter makes a plea for a “double hospitality” involving both word and touch. An ethics of hospitality, as shown in the previous chapters, involves empathizing with others through the exchange of stories, memories, and faiths—the aim being to work through the wounds of history and open a space for charity and gift. Here law is supplemented by love; and in this step toward a higher poetics of pardon there comes a point where narrative exchange—of histories, traditions, confessions, testimonies—often needs to be supplemented by an exchange of physical gestures. A point where narrative hospitality calls for carnal hospitality. Where the textual solicits the tactile. Where word gives way to touch.
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Ginor, Isabella, and Gideon Remez. "Ceasefire Violation Seals a Strategic Gain." In The Soviet-Israeli War, 1967-1973, 199–210. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780190693480.003.0017.
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The ceasefire that ostensibly ended the War of Attrition went into effect at midnight between 7 and 8 August 1970. Within minutes, the standstill provision that the US initiative had stipulated was broken by Soviet and Egyptian advancement of SAM batteries to the Suez Canal bank. US inspection flights by U-2 spy planes began too late to document the violation, and the Soviets rejected American protests. Israel responded by suspending compliance with the rest of Rogers’s peace plan, including UN mediation – leaving the United States with little benefit but the Soviets with a major gain. However, for domestic consumption Israel declared victory, which limited effective countering of the increased threat. Nasser’s death the following month and his unexpected succession by Anwar Sadat led to doubts about continuing dependence on Moscow.
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Taber, Douglass F. "Organocatalytic Carbocyclic Construction: The You Synthesis of (–)-Mesembrine." In Organic Synthesis. Oxford University Press, 2015. http://dx.doi.org/10.1093/oso/9780190200794.003.0070.
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Frank Glorius of the Universität Münster devised (Angew. Chem. Int. Ed. 2011, 50, 12626) a catalyst for the enantioselective acylation of a cyclopropene 1 to the ketone 3. Geum-Sook Hwang of Chungnam National University and Do Hyun Ryu of Sungkyunkwan University effected (J. Am. Chem. Soc. 2011, 133, 20708) the enantioselective addition of the diazo ester 5 to an α,β-unsaturated aldehyde 4 to give the cyclopropane 6. We showed (J. Org. Chem. 2011, 76, 7614) that face-selective allylation of an α-iodo enone 7 followed by Suzuki coupling and oxy-Cope rearrangement delivered the cyclopentanone 9. Karl Anker Jørgensen of Aarhus University combined (Org. Lett. 2011, 13, 4790) two organocatalysts to effect the addition of 11 to an α,β-unsaturated aldehyde 10, leading to the cyclopentenone 12. Tomislav Rovis of Colorado State University also used (Chem. Sci. 2011, 2, 1835) two organocatalysts to condense 13 with 14 to give the cyclopentanone 15. Gregory C. Fu, now at CalTech, found (J. Am. Chem. Soc. 2011, 133, 12293) that both enantiomers of the racemic allene 16 combined with 17 to give the cyclopentene 18 in high ee. Piotr Kwiatkowski of the University of Warsaw found (Org. Lett. 2011, 13, 3624) that under elevated pressure (8–10 kbar), enantioselective conjugate addition of nitromethane proceeded well even with a β-substituted cyclohexenone 19. Marco Bella of the Università di Roma observed (Adv. Synth. Catal. 2011, 353, 2648) remarkable diastereoselectivity in the addition of the aldehyde 22 to an activated acceptor 21. Following the procedure of List, Jiong Yang of Texas A&M University cyclized (Org. Lett. 2011, 13, 5696) 24 to 25 in high ee. Bor-Cherng Hong of the National Chung Cheng University described (Synthesis 2011, 1887) the double Michael combination of 26 with 27 to give 28 in high ee. Observing a secondary 13C isotope effect only at the β-carbon of 30, Li Deng of Brandeis University concluded (Chem. Sci. 2011, 2, 1940) that the addition to 29 was stepwise, not concerted. In contrast, the cyclization of 32 to 33 reported (Org. Lett. 2011, 13, 3932) by Tadeusz F. Molinski of the University of California San Diego likely was concerted.
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Taber, Douglass F. "Organocatalyzed C–C Ring Construction: The Hayashi Synthesis of PGE1 Me Ester." In Organic Synthesis. Oxford University Press, 2015. http://dx.doi.org/10.1093/oso/9780190200794.003.0073.
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Xiaohua Liu and Xiaoming Feng of Sichuan University devised (J. Org. Chem. 2013, 78, 6322) a catalyst that mediated the addition of the ylide 2 to the enone 1 to give 3. Peng-fei Xu of Lanzhou University found (Chem. Commun. 2013, 49, 4625) that the vinyl pyrrole 4 was sufficiently nucleophilic to add to 5, leading to the cyclobutane 6. Albert Moyano of the Universitat de Barcelona added (Eur. J. Org. Chem. 2013, 3103) 8 to the unsaturated aldehyde 7 to give the β-amino acid precursor 9. Eugenia Marqués-López and Mathias Christmann, now at Freie Universität Berlin effected (Synthesis 2013, 45, 1016) the intramolecular Michael cyclization of 10 to give 11. Delong Liu and Wanbin Zhang of Shanghai Jiao Tong University showed (Synthesis 2013, 45, 1612) that 12 and 13 could be combined to give the cyclopentane 14. Ismail Ibrahem and Armando Córdova of Mid Sweden University combined (Angew. Chem. Int. Ed. 2013, 52, 6050) 15 and 16 to give 17, with good control of the quaternary center. Kamal Nain Singh of Panjab University prepared (Synthesis 2013, 45, 1406) a proline-derived sulfoxide that mediated the addition of cyclohexanone 18 to 19. Intramolecular aldehyde alkylation is underdeveloped as a synthetic method. David W.C. MacMillan of Princeton University established (J. Am. Chem. Soc. 2013, 135, 9358) a single-electron transfer variant, cyclizing 21 to 22. Arianna Quintavalla of the University of Bologna effected (Adv. Synth. Catal. 2013, 355, 938) the double addition of nitromethane 24 to 23 to give 25. John Cong-Gui Zhao of the University of Texas at San Antonio reported (Chem. Eur. J. 2013, 19, 1666; J. Org. Chem. 2013, 78, 4153) parallel results (not pictured) with aryl enones as the acceptors. Bor-Cherng Hong of the National Chung Cheng University condensed (Eur. J. Org. Chem. 2013, 2472) 26 with the alcohol 27 to give 28. Again, good control of the quaternary center was observed. Marc C. Kimber of Loughborough University used (J. Org. Chem. 2013, 78, 3476) an organocatalyst to rearrange the prochiral endoperoxide 29 to the hydroxy enone, to which malonate 30 was added to give 31.
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Maynard Smith, John, and Eors Szathmary. "Development in simple organisms." In The Major Transitions in Evolution. Oxford University Press, 1997. http://dx.doi.org/10.1093/oso/9780198502944.003.0016.
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Complex multicellular organisms, whose bodies consist of differentiated cells of many kinds, have evolved independently on three occasions—animals, higher plants and fungi. In addition, multicellular organisms with a lesser degree of cellular differentiation have evolved on a number of occasions. For example, the algae have given rise to ‘seaweeds’ several times. In this and the next three chapters, we discuss the origin and subsequent evolution of such organisms. Some 540 million years ago, at the beginning of the Cambrian, there appeared an array of multicellular marine animals, including the major phyla that exist today—coelenterates, platyhelminths, annelids, arthropods, molluscs, echinoderms and others. Chordates are also present in the Cambrian: they are not known from the earliest deposits, in which only hard parts are preserved, but are present in the slightly later Burgess Shale, in which soft-bodied forms are preserved. Forty years ago, this sudden appearance of metazoan fossils was not only a puzzle but something of an embarassment: the absence of any known fossils from earlier rocks was a weapon widely used by creationists. Today, the fossil evidence for prokaryotes goes back 3000 million years, and for protists some 1000 million years. The Cambrian explosion remains a puzzle, however, which has been only fitfully illuminated by the discovery of the enigmatic soft-bodied Ediacaran fauna, which had a worldwide distribution between 580 and 560 million years ago. There are still doubts about how these fossils should be interpreted (Conway Morris, 1993). The orthodox, and more plausible, view is that the fauna is dominated by coelenterates, with some specimens identified as echinoderms and annelids. An alternative interpretation (Seilacher, 1992) is that they belong to an extinct clade of multicellular eukaryotes, the ventobionts, probably lacking an alimentary canal, muscles and nervous system. Although such organisms may have existed, at least some of the Ediacaran fauna have been successfully compared to recent metazoans. If the interpretation of most of these fossils as coelenterates proves to be correct, it would fit in well with the morphological and molecular evidence. The molecular data suggest that coelenterates arose early, but probably not independently of other metazoans. Morphologically they are simple in being diploblastic (formed from two cell layers), in contrast to the triploblastic animals that predominate in the Cambrian.
Conference papers on the topic "Canal double"
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Elias, A., G. Le Corff, J. L. Bouvier, Ph Villain, and A. Serradimigni. "DISCREPANCIES BETWEEN VENOGRAPHY AND REAL TIME B MODE ULTRASOUND IMAGING IN THE DIAGNOSIS OF DEEP VEIN THROMBOSIS." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1642892.
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Methods : in this prospective study, real time B Mode ultrasound imaging (USI) was compared to bilateral ascending contrast venography, double blindly, in 430 patients suspected of deep vein thrombosis (DVT) or pulmonary embolism.A complete scan of the venous system from the inferior vena cava to the calf veins, was performed with a high resolution duplex system (DIASONICS DRF 400) and coupled systematically with a C.W. Doppler examination. The results obtained by USI were thus compared to the venograms performed on a total of 854 legs.Results : there are corresponding results in 95% of the legs (808/854). If we consider venography as the standard of reference, the sensitivity of USI is 98% (325/333) and the specificity 94% (483/514). Isolated calf vein thrombosis are detected in 91% (84/92) of the legs and proximal DVT in 100% (241/241) in this series whatever the topography and the extension of the thrombosis and whatever the degree of the obstruction of the vein.Discrepancies found in 46 legs are related to :- 8 DVT located in the calf (6 in the presumed healthy leg) diagnosed only by venography.- 27 DVT (18 distal, 9 femoral or iliac) detected only by USI- 9 doubtful examinations with USI not confirmed by venography- 2 doubtful venograms with negative USI test.Comments : Calf vein thrombosis especially located in the soleal sinuses and the gastrocnemius with in most cases the direct image of the thrombus are more often detected by USI provided that the technique and the equipment are appropriate.The absence of visualisation of venous segments with venography is not specific of venous thrombosis. These veins non affected by the thrombosis are not filled by the contrast medium when located above in occluded ilio-femoral or ilio-caval junction or when they are the site of extrinsic compression. The direct image of the vein and the surrounding structures obtained with USI enhances the diagnostic sensitivity and specificity and provides precision of the exact extension of the thrombosis.Due to these differences, can venography still be considered as the standard of reference in the diagnosis of DVT and their precise localisation ?