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Autism spectrum disorder (ASD) and obsessive-compulsive disorder (OCD) often share phenotypes of repetitive behaviours, possibly underpinned by abnormal decision-making. To compare neural correlates underlying decision-making between these disorders, brain-activation of boys with ASD (N=24), OCD (N=20) and typically developing controls (N=20) during gambling was compared, and computational modelling compared performance. Patients were unimpaired on number of risky decisions, but modelling showed that both patient groups had lower choice consistency and relied less on reinforcement learning compared to controls. ASD individuals had disorder-specific choice perseverance abnormalities compared to OCD individuals. Neurofunctionally, ASD and OCD boys shared dorsolateral/inferior frontal underactivation compared to controls during decision-making. During outcome anticipation, patients shared underactivation compared to controls in lateral-inferior/orbitofrontal cortex and ventral striatum. During reward receipt, ASD boys had disorder-specific enhanced activation in inferior frontal/insular regions relative to OCD boys and controls. Results showed that ASD and OCD individuals shared decision-making strategies that differed from controls to achieve comparable performance to controls. Patients showed shared abnormalities in lateral-(orbito)fronto-striatal reward circuitry, but ASD boys had disorder-specific lateral inferior frontal/insular overactivation, suggesting that shared and disorder-specific mechanisms underpin decision-making in these disorders. Findings provide evidence for shared neurobiological substrates that could serve as possible future biomarkers.

Colloque avec actes et comité de lecture. Internationale.; International audience; Ce travail concerne la modélisation du comportement viscoplastique d'un monocristal poreux, constitué d'une matrice continue, dans laquelle sont distribuées de façon uniforme des cavités dont la taille caractéristique est petite devant celle du cristal environnant. Ce type de microstructure peut se rencontrer dans certains aciers inoxydables austénitiques irradiés, où des cavités peuvent apparaître à l'intérieur des grains de ces polycristaux (voir par exemple [Garner, F. A., 2012. Radiation Damage in Austenitic Steels. Comprehensive Nuclear Materials, 33-95]). La matrice cristalline est prise à symétrie cubique et trois types de familles sont considérées successivement : les cubiques faces centrées, les cubiques centrées et les ioniques. Un chargement en contrainte effective hydrostatique est considéré. La méthode des stratifiés de rang infini de [Idiart, M.I., 2008. Modeling the macroscopic behavior of two-phase nonlinear composites by infinite-rank laminates. J. Mech. Phys. Solids 56, 2599-2617] est mise en ?uvre. Des développements analytiques permettent d'écrire le potentiel effectif en contrainte en fonction d'une contrainte hydrostatique d'écoulement qui dépend de la microstructure, des paramètres matériaux locaux et du chargement. Des simulations numériques à base de transformées de Fourier rapides (méthode FFT de [Moulinec, H., Suquet, P., 1994. A fast numerical method for computing the linear and nonlinear properties of composites. C. R. Acad. Sci. Paris II 318, 1417?1423]) sont réalisées sur des microstructures tridimensionnelles poreuses périodiques sous chargement en contrainte effective hydrostatique. Les trois types de familles énumérées ci-dessus sont considérés successivement. Différentes porosités et différentes valeurs de l'exposant de fluage sont traitées. Un bon accord est obtenu entre les résultats FFT et ceux du modèle basé sur la méthode des stratifiés. Cette comparaison permet de proposer une forme analytique pour la contrainte hydrostatique d'écoulement. Les résultats sont en accord avec des résultats de la littérature ([Han, X., Besson, J., Forest, S., Tanguy, B., Bugat, S., 2013. A yield function for single crystals containing voids. Int. J. Solids Struct. 50, 2115?2131], [Mbiakop, A., Constantinescu, A., Danas, K., 2015. An analytical model for porous single crystals with ellipsoidal voids. J. Mech. Phys. Solids 84, 436?467], [Paux, J., Morin, L., Brenner, R., Kondo, D., 2015. European Journal of Mechanics A/Solids 51, 1-10]).

Aim To assess the effectiveness and safety of intravitreal dexamethasone implants for treating post-surgical macular oedema, including Irvine-Gass syndrome refractory to first-line treatments. Methods Descriptive, observational, retrospective, consecutive, uncontrolled, multicentre, national case series. 50 patients were included in the study between March 2011 and June 2013 with a minimum 6 months follow-up. At baseline, each patient received a dexamethasone implant 0.7 mg (Ozurdex). Best-corrected visual acuity (BCVA), central subfield macular thickness (CSMT), and intraocular pressure (IOP) were measured at baseline and then monthly. The main outcome measure was the mean change in BCVA (in ETDRS letters (Early Treatment Diabetic Retinopathy Study): L) Results Baseline mean±SD BCVA was 55.7±15.4 L. At month 2, BCVA was 71.8±10.5 L and 61.2% of patients had an increase of more than 15 letters. Baseline mean CSMT was 544±117.2 μm and this decreased to 302 μm at month 2. Anatomic and functional recurrences were both first detected from month 3 and continued throughout follow-up, with values consistently above baseline. The peak in IOP was reached in month 1 with mean IOP of 15.3±4.6 mm Hg. Of the 39/50 patients followed up for 12 months, 49% received a second injection. The anatomic and functional response and safety patterns were similar to that obtained with the first intravitreal injection, demonstrating Ozurdex’s reproducibility. However, more than half of the patients followed-up for at least 1 year presented neither functional nor anatomical recurrence. Conclusions Ozurdex would appear to be an interesting alternative therapy for treating post-surgical macular oedema, including Irvine-Gass syndrome refractory to first-line treatments.

International audience; This work is devoted to the modeling of the effective elastic behavior of nanoporous materials containing both spherical and ellipsoidal in shape bubbles, typically the irradiated uranium dioxide (UO2) studied by the French “Institut de Radioprotection et de Sûreté Nucléaire” to investigate the response of fuel rods under reactivity initiated accident (RIA) conditions. As a first approximation, this material exhibits at least two populations of bubbles: (1) intragranular bubbles, almost spherical in shape with a typical diameter of a few nanometers, (2) intergranular bubbles, roughly lenticular in shape whose size ranges from tens to several hundred nanometers. Molecular dynamics results of [Colbert, 2012] and [Jelea et al., 2011] show the existence of a non-neglectible surface effect on the effective elastic behavior for UO2 at the intragranular bubbles scale, particularly when the surface/volume ratio of these bubbles increases.Analytical micromechanical models ([Duan et al., 2005], [Brisard et al., 2010]) concerning materials with an isotropic distribution of nano-sized spherical inclusions have been extended to the case of materials with two populations of pressurized bubbles, one relative to spherical bubbles and the other relative to ellipsoidal bubbles. The proposed model follows the general framework of the so-called ‘morphologically representative pattern-based approach’ of [Stolz and Zaoui, 1991] and is compared to existing models (with or without surface effects). The relevance of the analytical model has been assessed by comparison with finite elements simulations. A preliminary study has been performed on the evolution of the elastic moduli of the irradiated UO2 fuel obtained from this model during a RIA test condition.

This study deals with the detonation initiation by shock of condensed melt-cast high explosives. Solid explosives are heterogeneous materials, made of energetic material grains in a binder, which can be energetic itself. If the existence of hot-spots, preferred initiation sites for chemical reaction at the local scale, is widely recognized, the reaction growth topology, and the microstructure influence, are poorly known for melt-cast explosives. We study here two melt-cast explosive families: hexolites, a mix of hexogen (RDX) grains and trinitrotoluene (TNT) binder, and ontalites made of nitrotriazolone (NTO) and TNT. This study has been focused on the triptyque: characterization - experimentations - modeling.An important work of compilation and re-exploitation of literature data, combined with pure explosives’ equation of state modeling, allowed us to define laws to calculate the explosives’ comportment under a shock solicitation. These ones have been validated, thanks to a mixing method, on different melt-cast and cast-curd plastic bonded explosives. At the same time, the compositions’ microstructure has been also characterized via granulometry measurements and microtomographies, never published for this type of explosive.Plate impact tests have been performed in order to establish the reactive shock trajectory of these compositions, allowing us to determine the relation between the run-distance of detonation and the input pressure. It brought the microstructure influence on hexolite shock sensitivity to light, and gave us some first results for ontalites. The use of continuous and innovative measurements, as microwave interferometry and chirped fiber Bragg gratings, allowed us to study the shock to detonation transition (SDT) with a resolution never seen before. Finally, non-sustained plate impact test have been performed for a validation purpose.A SDT model is proposed. Based on a germination-growth approach of deflagration fronts at the local scale, it takes into account the explosive’s microstructure. This work seems to show the grain fragmentation under shock influence, point we will have to study in the future. Finally, a completion step of reactions, associated with chemical kinetics calculations, has been studied., Ce travail de thèse porte sur les mécanismes d’amorçage en détonation par choc des explosifs solides de type coulé-fondu. Les explosifs solides sont des matériaux hétérogènes constitués de grains de matière énergétique dans un liant pouvant être lui-même énergétique. Si l’existence des points chauds, sites préférentiels d’initiation des réactions chimiques à l’échelle locale, est largement reconnue, la topologie de la croissance des réactions, et l’influence de la microstructure sur cette dernière n’est que peu étudiée dans les explosifs coulés-fondus. Deux familles d’explosifs ont été retenues pour cette étude : les hexolites, mélanges de grains d’hexogène (RDX) et d’un liant trinitrotoluène (TNT) et les ontalites, composées d’oxynitrotriazole (ONTA) et de TNT. Les recherches se sont orientées autour du triptyque : caractérisation – expérimentations – modélisation.Un important travail de compilation et de ré-exploitation de données issues de la littérature, associé à une modélisation des équations d’état des explosifs purs, ont permis de définir des lois permettant de calculer le comportement de ces derniers sous choc. Ces lois ont ensuite été validées par une méthode de mélange sur différentes compositions coulées-fondues et composites. Parallèlement, la microstructure des compositions d’étude a également été caractérisée via des mesures de granulométrie et de microtomographie, inédites sur ce type d’explosif.Des expérimentations d’impact plan soutenu ont été réalisées afin d’établir les diagrammes de marche des ondes de choc réactives, permettant de relier la profondeur de transition à la détonation à la pression de sollicitation. Elles ont permis de mettre en lumière l’influence de la microstructure sur la sensibilité au choc de deux hexolites et d’acquérir des données sur deux ontalites. L’utilisation de deux métrologies innovantes, la radio-interférométrie à 94 GHz et les fibres optiques à réseau de Bragg, a permis de mesurer la transition choc – détonation (TCD) de façon continue avec une résolution inédite. Enfin des essais d’impact plan non soutenu ont été réalisés à des fins de validation.Un modèle de TCD est proposé. Ce dernier, basé sur une approche de germination-croissance des fronts de déflagration à l’échelle locale, permet de prendre en compte la microstructure des explosifs. Ces travaux semblent mettre en évidence l’influence de la fracturation des grains d’explosif sous choc, qu’il conviendra d’étudier dans le futur. Enfin, une étape de terminaison des réactions lors de la TCD, associée à des calculs thermocinétiques détaillés, a été étudiée.

CROCUS is a teaching and research zero-power reactor operated by the Laboratory for Reactor Physics and Systems Behaviour (LRS) at the Swiss Federal Institute of Technology (EPFL). Three new experimental programmes are scheduled for the forthcoming years. The first programme consists in an experimental investigation of mechanical noise induced by fuel rods vibrations. An in-core device has been designed for allowing the displacement of up to 18 uranium metal fuel rods in the core periphery. The vibration amplitude will be 6 mm in the radial direction (±3 mm around the central position), while the frequency can be tuned between 0.1 and 5 Hz. The experiments will be used to validate computational dynamic tools currently under development, which are based on DORT-TD and CASMO/S3K code systems. The second programme concerns the measurement of in-core neutron noise for axial void profile reconstruction. Simulations performed at Chalmers University have shown how the void fraction and velocity profiles can be reconstructed from noise measurements. The motivation of these experiments is to develop an experimental setup to validate in-core the method in partnership with Chalmers University. The third experimental programme aims at continuing the validation effort on the nuclear data required in the calculation of GEN-III PWR reactors with heavy steel reflectors. This is a collaboration with CEA Cadarache that extends the results of the PERLE experiments carried out in the E reactor at CEA. Scattering cross sections at around 1 MeV will be studied separately by replacing successively the water reflector by sheets of stainless steel alloy and pure metals – iron, nickel, and chromium. Data will be extracted from the measured flux attenuation using foils in the metal reflector and from the criticality effects of these reflectors. In parallel to the three reactor experiments, we develop in-core detectors and measurement systems. Following the last development of a neutron noise measurement station in pulse mode, a second neutron noise station in current mode is being designed. In current mode the reactor can be used at higher power without dead time effects. It allows faster measurement time or lower results uncertainties. Finally, a joint development of a full new detection system based on chemical vapour deposited (sCVD) diamond has been started with the CIVIDEC instrumentation start-up company. A first prototype has been tested in November 2015 in CROCUS. One of the main purposes is to work on the discrimination of gammas, thermal and fast neutrons for demonstrating the interest of this detector type in a mixed neutron-gamma field.

The Old Nubian Texts from Attiri is the first publication in the Dotawo: Monographs series. It presents heretofore unpublished material: an edition of a series of manuscripts discovered during the Aswan High Dam campaign at the site of Attiri, a rocky island in the Batn el-Hajjar region in Sudan, and does so in an innovative way, through an intensive collaboration of the editors under the name of the Attiri Collaborative. By bringing together their diverse backgrounds in linguistics, archeology, Bible studies, history, anthropology, and philology, the editors hope to have provided an example of a new model of collective manuscript editing and the results such collaboration can attain. The collection consists of 15 manuscript fragments that were all written in Old Nubian. Among these manuscripts special mention should be made of two parchment leaves from a codex dedicated to works on the Archangel Michael, a lectionary containing fragments from the Gospel of Matthew and the Second Letter to the Corinthians, as well as a rare letter written on a leather sheet.

International audience; L’UO2 irradié contient deux populations de cavités saturées par des gaz de fission (« bulles ») :- des cavités intergranulaires dont la taille varie de quelques dizaines à plusieurs centaines de nanomètres ;- des cavités intragranulaires plutôt sphériques, dont la taille est de l’ordre du nanomètre. Des travaux récents ont montré qu’il existe un effet de surface à l’échelle des cavités nanométriques qui modifie le comportement élastique effectif du combustible [Jelea et al., 2011][Colbert, 2012]. Ce travail propose un modèle micromécanique analytique capable de tenir compte de cette microstructure hétérogène ainsi que de l’effet de surface afin de décrire le comportement élastique macroscopique de l’UO2 irradié.

Type 10A phosphodiesterase (PDE10A) is highly expressed in the striatum, in striatonigral and striatopallidal medium-sized spiny neurons (MSNs), which express D1 and D2 dopamine receptors, respectively. PDE10A inhibitors have pharmacological and behavioral effects suggesting an antipsychotic profile, but the cellular bases of these effects are unclear. We analyzed the effects of PDE10A inhibition in vivo by immunohistochemistry, and imaged cAMP, cAMP-dependent protein kinase A (PKA), and cGMP signals with biosensors in mouse brain slices. PDE10A inhibition in mouse striatal slices produced a steady-state increase in intracellular cAMP concentration in D1 and D2 MSNs, demonstrating that PDE10A regulates basal cAMP levels. Surprisingly, the PKA-dependent AKAR3 phosphorylation signal was strong in D2 MSNs, whereas D1 MSNs remained unresponsive. This effect was also observed in adult mice in vivo since PDE10A inhibition increased phospho-histone H3 immunoreactivity selectively in D2 MSNs in the dorsomedial striatum. The PKA-dependent effects in D2 MSNs were prevented in brain slices and in vivo by mutation of the PKA-regulated phosphorylation site of 32 kDa dopamine- and cAMP-regulated phosphoprotein (DARPP-32), which is required for protein phosphatase-1 inhibition. These data highlight differences in the integration of the cAMP signal in D1 and D2 MSNs, resulting from stronger inhibition of protein phosphatase-1 by DARPP-32 in D2 MSNs than in D1 MSNs. This study shows that PDE10A inhibitors share with antipsychotic medications the property of activating preferentially PKA-dependent signaling in D2 MSNs.

Propices aux polémiques et à la caricature, les années 1950 sont au nombre des périodes encore mal connues de l’histoire de la CGT. Le Centre d’histoire sociale du XXe siècle et l’Institut CGT d’histoire sociale ont uni leurs compétences afin de mieux comprendre ce que fut la Confédération en ces temps difficiles. Tel était l’objet du colloque tenu en novembre 2003 dont rend compte le présent ouvrage. Durant la guerre froide, le poids du parti communiste a très fortement pesé sur la vie de la Confédération. Aussi importait-il de s’interroger sur les conséquences, directes ou non, de cette relation sur l’attitude cégétiste, qu’il s’agisse de son opposition aux gouvernements ou au patronat, de la lutte pour la paix et contre les guerres coloniales. Les auteurs s’intéressent au fonctionnement de la CGT, son « gouvernement », ses cadres et ses militants. Ils mettent en lumière les pratiques consécutives à l’engagement de la CGT dans la gestion des comités d’entreprise et de la Sécurité sociale. L’ouvrage traite encore des débats qui l’ont traversée : paupérisation, planification, stratégie syndicale internationale, relations avec les autres confédérations françaises, etc. Au fil d’études spécifiques menées à différentes échelles – locales, départementales, professionnelles –, les travaux soulignent la grande diversité des comportements cégétistes. Ils font enfin une large place aux militants et, plus précisément, aux militantes dont le rôle grandit durant la décennie. Loin de toute vision unilatérale ou réductrice, le présent ouvrage restitue pour la première fois l’histoire de la principale organisation syndicale française saisie au début des Trente Glorieuses.

La réunification de la CGT chez les cheminots précède celle de la Confédération de trois mois : elle est acquise le 10 décembre 1935 sur une base paritaire avec un secrétariat collectif de huit membres. Le Congrès de juin 1938 confirme ce choix et détermine pour chaque composante un secrétaire général, P. Semard pour les ex-CGTU et J. Jarrigion pour les ex-confédérés. Comme partout, il y a éviction des militants communistes après la signature du Pacte germano-soviétique. La rupture est accent...

National audience; Ce travail propose un modèle de type Mori et Tanaka généralisé, fondé sur l'approche par motifs morphologiques représentatifs, afin d'estimer les propriétés élastiques effectives des matériaux nanoporeux avec des cavités sphériques et sphéroïdales dont la distribution des centres est ellipsoïdale.

International audience; This work is devoted to the theoretical modeling of the overall elastic properties of random nanoporous materials.Focussing on irradiated uranium dioxide (UO2) material-type studied by the French ”Institut de Radioprotectionet de Sˆuret´e Nucl´eaire” to investigate the response of fuel rods under accident conditions, we considernanomaterials exhibiting two populations of cavities at two different scales: 1/ small scale cavities almost sphericalin shape (radius r) with a typical diameter of a few nanometers, 2/ larger scale cavities roughly ellipsoidal inshape (major axis b and shape ratio w) with a typical size of a few microns. Recent molecular dynamics results [1]show the existence of a non-neglectible surface effect on the effective elastic behavior for uranium dioxide at thesmallest scale, particularly when the surface/volume ratio is drastically increasing.Analytical micromechanical [2, 3] models concerning materials with an isotropic distribution of nano-sizedspherical inclusions are extended here to the case of materials with two populations of voids. The spatial distributionis assumed to be generally ellipsoidal which is more general than the case of spherical and ellipsoidalcavities randomly distributed in space and in orientation. The proposed model follows the general framework ofthe so-called ’morphologically representative pattern approach’ [4] and is called Mori-Tanaka-Generalized (MTG)model. This model is compared to existing models (with or without surface effects). Particularly, the present modelallows a generalization of the Ponte Casta˜neda and Willis (PCW) model [5] to the case of porous media with surfaceeffects.

Purpose To describe unusual retinal findings of a patient affected by hemochromatosis. Methods Case report of a 49-year-old patient who presented a progressive loss of vision. Fundus photography, fluorescein angiography, full-field electroretinogram, autofluorescence imaging, and spectral domain optical coherence tomography were performed. The patient was known to be homozygous for the C282Y mutation in the HFE gene. Results Visual acuity was measured at 20/20 on his right eye and 20/25 on his left eye. Retinal imaging showed alterations of the retinal pigment epithelium clearly visible on fundus autofluorescence and fluorescein angiography. The spectral domain optical coherence tomography showed retinal pigmentary epithelial atrophy associated with irregularities and focal interruption of the ellipsoid zone. A thin retina was also observed in the foveolar region associated to a thickened choroid. Full-field electroretinogram showed a decrease of rods and cones responses. Conclusion Here, the authors describe the retinal findings of a patient affected by hemochromatosis, characterized by unusual retinal pigment epithelium changes associated to altered visual function. The authors hypothesize that the retinopathy could be linked to hemochromatosis because of the pathophysiology of iron homeostasis and the toxicity of iron overload for the photoreceptors.

International audience; Homogenization estimates for viscoplastic polycrystals are derived by applying the generalized-secant linearization scheme of Liu & Ponte Castañeda (J. Mech. Phys. Solids 52 (2004), 1175–1211) to the constitutive description with strain rates as primary variables. The resulting estimates are thus particularly suitable for simulating mechanical processes where deformations are imposed and where the material softens. Their accuracy is preliminarily assessed in the context of a model material system. Good agreement with previous estimates is found.; Des estimations relatives à l'homogénéisation de polycristaux viscoplastiques sont obtenues en appliquant la méthode de linéarisation sécante généralisée de Liu & Ponte Castañeda (J. Mech. Phys. Solids 52 (2004), 1175– 1211) au cas d'une relation constitutive où les taux de déformation sont des variables primaires. Les estimations obtenues sont particulièrement adaptées pour simuler des chargements mécaniques où les déformations sont imposées et où le matériau s'adoucit. La précision de ces estimations est évaluée au préalable dans le cas d'un système matériau modèle. Un bon accord est obtenu avec des estimations antérieures.

International audience

International audience; This work is devoted to the modeling of the effective elastic properties of nanoporous materials containingspherical and spheroidal voids. The motivation for this work is relative to the behavior of the irradiated uraniumdioxide (UO2) studied by the French ”Institut de Radioprotection et de Sûreté Nucléaire” to investigate the responseof fuel rods under a reactivity accident. As a first approximation, this material exhibits two populations of cavities : i.intragranular cavities, almost spherical in shape with a typical diameter of a few nanometers, ii. intergranular cavities,lenticular in shape whose the size ranges from nanometers to few hundred nanometers. Molecular dynamics resultsshow the existence of a non-neglectable surface effect on the effective elastic behavior for uranium dioxide at thenanometric scale. A generalized Mori-Tanaka model based on the morphologically representative pattern approachis proposed to estimate the effective elastic properties of such a material. The surface effect is taken into accountby introducing the characteristic lengths of the cavities in the model. The abilities of this model are illustrated inthe particular case of a material containing spherical and spheroidal randomly oriented cavities whose the spatialdistribution of the centers is isotropic.; Ce travail concerne la modélisation des propriétés élastiques effectives des matériaux nanoporeux contenantdes cavités sphériques et sphéroïdales. La motivation de ce travail est relative au comportement du dioxyde d’uraniumirradié (UO2), étudié par l’Institut de Radioprotection et de Sûreté Nucléaire (IRSN) afin d’estimer la tenue descrayons combustibles lors d’un accident de réactivité. Ce matériau possède deux populations de cavités : i. des cavitésintragranulaires plutôt sphériques de quelques nanomètres, ii. des cavités intergranulaires lenticulaires dont la taillevarie de quelques dizaines à plusieurs centaines de nanomètres. Des travaux de dynamique moléculaire ont montrél’existence d’un effet de surface à l’échelle des cavités nanométriques dans l’UO2 qui influence le comportementélastique apparent. Un modèle de type Mori et Tanaka généralisé, fondé sur l’approche par motifs morphologiquesreprésentatifs, permettant d’estimer les propriétés élastiques effectives d’un tel matériau est proposé. L’effet de surfaceprésent à l’échelle nanométrique est pris en compte via l’introduction des tailles caractéristiques des cavités dans lemodèle. Les possibilités offertes par le modèle sont illustrées dans le cas particulier d’un matériau contenant descavités sphériques et sphéroïdales orientées aléatoirement et dont la distribution des centres est isotrope.

Abstract "Sour Service" refers to a well environment containing Hydrogen Sulfide (H2S), which is naturally associated with acid conditions. It is well known that H2S is hazardous to human health, living organisms, and more generally to the environment. It is for this reason that wells found with Sour Gas were often carefully plugged and abandoned in the past. H2S can also lead to catastrophic brittle failure of drillstring components: the physical phenomenon associated with Sour Service Environments and affecting steel based products under applied or residual stress is known as H2S embrittlement or more specifically as Sulfide Stress Cracking (SSC). With the increasing demand of gas worldwide, some highly sour oil and gas reservoirs are being explored, mainly in Russia, the Middle East, China and North America, and are now more and more associated with complex well profiles – such as deep reservoirs or extended reach wells. The use of high strength drill pipe is essential to achieve such drilling objectives; however it does represents significant technical challenges in terms of drill pipe integrity and operational safety with the current high strength grades available on the market, such as S-135 drill pipe. Because higher strength is generally detrimental to Sulfide Stress Cracking, innovative chemistries and new heat treatment processes are needed to push Sour Service material limits even further. A new high strength drill pipe family has been developed to specifically address those challenges: these new grades exhibit a minimum Yield Strength (120 ksi) higher than the current Sour Service grades available on the market as described by the current industry standards (95ksi or 105 ksi Specified Minimum Yield Strength). In order to guarantee the SSC resistance of these high strength materials, pipes and tool joints are tested as per the NACE standards. A first string of this high strength material is already being commercialized and used for the first time in offshore wells in the North Sea.