Abrégé

The present invention relates to the treatment of cancer. Here, the inventors identified a subset of prostate cancer patients showing an up-regulation of the epigenetic enzymes SUV4-20H1 and SUV4-20H2, two methyltransferases responsible for the di- and tri- methylation of histone H4 at lysine 20 (H4K20me2/3). Consistent with this, the inventors demonstrate that the pharmacological inhibition of both SUV4-20H1 and SUV4-20H2 enzymes by the chemical compound A196 (14) leads to the complete loss of H4K20me2/3 states in prostate cancer cells. Although displaying epigenetic reprograming at genome-wide levels, cancer cells display any significant impairment in their survival or proliferation, thereby demonstrating that the inhibition of SUV4-20H1 and SUV4-20H2 is not toxic per se. Yet, the inventors showed that the pharmacological inhibition of SUV4-2H1 and SUV4-20H2 subtly affects DNA repair mechanisms and the levels of trapped topoisomerase II (TOPO2) complex in silent chromatin regions upon TOPO2 poisons. This creates in vitro as well as in vivo a lethal synergy between A196 and the TOPO2-poison etoposide in prostate cancer cells. Altogether, the results of the inventors showed that the simultaneous inhibition of SUV4-20H and TOPO2 enzymatic activity constitutes indeed a new therapeutic approach for the treatment of advanced or metastatic prostate cancers, which are particularly addicted to SUV4-20H2 and TOPO2 activities. Other cancers could also benefit of this drug combination, since the co-treatment of A196 and etoposide induces similar lethal synergy in other epithelial cancer cells such as breast cancer cell lines. Thus, the present invention relates to a combination of a SUV4-20H inhibitor and a TOPO2 inhibitor for use in the treatment of a cancer in a subject in need thereof.

Classes IPC  ?

• A61K 31/136 - Amines, p. ex. amantadine ayant des cycles aromatiques, p. ex. méthadone ayant le groupe amino lié directement au cycle aromatique, p. ex. benzène-amine
• A61K 31/501 - PyridazinesPyridazines hydrogénées non condensées et contenant d'autres hétérocycles
• A61K 31/704 - Composés ayant des radicaux saccharide liés à des composés non-saccharide par des liaisons glycosidiques liés à un composé carbocyclique, p. ex. phloridzine liés à un système carbocyclique condensé, p. ex. sennosides, thiocolchicosides, escine, daunorubicine, digitoxine
• A61K 31/7048 - Composés ayant des radicaux saccharide et des hétérocycles ayant l'oxygène comme hétéro-atome d'un cycle, p. ex. leucoglucosane, hespéridine, érythromycine, nystatine
• A61K 45/06 - Mélanges d'ingrédients actifs sans caractérisation chimique, p. ex. composés antiphlogistiques et pour le cœur
• A61P 35/00 - Agents anticancéreux

Abrégé

A flame retardant treatment of a lignocellulosic material, which includes: optionally steam exploding the lignocellulosic material, impregnating the optionally steam-exploded lignocellulosic material, in or with an aqueous solution, from 0.5% to 10% of phytic acid and from 1% to 30% of urea, based on the total weight of the aqueous solution, optionally drying of the impregnated lignocellulosic material, until the impregnated lignocellulosic material has a moisture content from 5% to 20% by weight, cooking the impregnated and optionally dried lignocellulosic material, the resulting flame-retarded lignocellulosic material including a phosphorous content originating from the phytic acid from 0.1% to 10% by weight. Also, the resulting flame-retarded lignocellulosic material and the use thereof for manufacturing flame-retarded composite materials based on plant fibres, woven or nonwoven flame-retarded flexible materials based on plant fibres, and particularly textiles, flame-retarded materials based on wood fibres and/or on wood particles, and particularly flame-retarded wood panels.

Classes IPC  ?

• B27K 3/02 - ProcédésAppareillage
• B27K 3/34 - Agents d'imprégnation organiques
• B27K 3/36 - Composés aliphatiques
• B27K 3/38 - Composés aromatiques
• B27K 3/50 - Mélanges de différents agents d'imprégnation organiques

Abrégé

A nickel-silicon catalyst for dry reforming of methane, wherein the nickel is present in an elemental weight percent of 1 to 7.5% considering the total weight of the catalyst, said nickel-silicon catalyst comprising a silicon oxide support bearing the nickel nanoparticles; and wherein the dispersion rate of the catalyst is at least 15%.

Classes IPC  ?

• B01J 21/08 - Silice
• B01J 23/755 - Nickel
• B01J 35/00 - Catalyseurs caractérisés par leur forme ou leurs propriétés physiques, en général
• B01J 35/10 - Catalyseurs caractérisés par leur forme ou leurs propriétés physiques, en général solides caractérisés par leurs propriétés de surface ou leur porosité
• B01J 35/02 - Catalyseurs caractérisés par leur forme ou leurs propriétés physiques, en général solides
• B01J 37/02 - Imprégnation, revêtement ou précipitation
• C01B 3/40 - Production d'hydrogène ou de mélanges gazeux contenant de l'hydrogène par réaction de composés organiques gazeux ou liquides avec des agents gazéifiants, p. ex. de l'eau, du gaz carbonique, de l'air par réaction d'hydrocarbures avec des agents gazéifiants avec des catalyseurs caractérisée par le catalyseur
• B01J 37/18 - Réduction avec des gaz contenant de l'hydrogène libre

Abrégé

A nickel-silicon catalyst, wherein the nickel is present in an elemental weight percent of 1 to 7.5% considering the total weight of the catalyst, said nickel-silicon catalyst comprising a silicon oxide support bearing the nickel nanoparticles; and wherein the dispersion of the catalyst is at least 15%.

Classes IPC  ?

• B01J 21/08 - Silice
• B01J 23/755 - Nickel
• B01J 35/00 - Catalyseurs caractérisés par leur forme ou leurs propriétés physiques, en général
• B01J 35/10 - Catalyseurs caractérisés par leur forme ou leurs propriétés physiques, en général solides caractérisés par leurs propriétés de surface ou leur porosité
• B01J 35/02 - Catalyseurs caractérisés par leur forme ou leurs propriétés physiques, en général solides
• B01J 37/02 - Imprégnation, revêtement ou précipitation
• C01B 3/40 - Production d'hydrogène ou de mélanges gazeux contenant de l'hydrogène par réaction de composés organiques gazeux ou liquides avec des agents gazéifiants, p. ex. de l'eau, du gaz carbonique, de l'air par réaction d'hydrocarbures avec des agents gazéifiants avec des catalyseurs caractérisée par le catalyseur
• B01J 37/18 - Réduction avec des gaz contenant de l'hydrogène libre

Abrégé

The present invention relates to a flame retardant treatment of a lignocellulosic material, characterized in that it comprises the following steps: - optionally steam explosion of the lignocellulosic material, - impregnation of the optionally steam-exploded lignocellulosic material, in or with an aqueous solution comprising from 0.5% to 10% of phytic acid and from 1% to 30% of urea, and preferably from 3% to 7% of phytic acid and from 15% to 22% of urea, said percentages being expressed by weight relative to the total weight of the aqueous solution, - optionally drying of the impregnated lignocellulosic material, until it has a moisture content ranging from 5% to 20%, said percentages being expressed by weight relative to the total weight of the impregnated lignocellulosic material, - cooking of the impregnated and optionally dried lignocellulosic material, the resulting flame-retarded lignocellulosic material comprising a content of phosphorus originating from the phytic acid ranging from 0.1% to 10%, preferably ranging from 0.3% to 3%, said percentages being expressed by weight relative to the total weight of the flame-retarded lignocellulosic material. The invention also relates to the resulting flame-retarded lignocellulosic material and the use thereof for manufacturing: - flame-retarded composite materials based on plant fibres, - woven or nonwoven flame-retarded flexible materials based on plant fibres, and particularly textiles, - flame-retarded materials based on wood fibres and/or on wood particles, and particularly flame-retarded wood panels.

Classes IPC  ?

• B27K 3/02 - ProcédésAppareillage
• B27K 3/34 - Agents d'imprégnation organiques
• B27K 3/42 - Composés aromatiques nitrés, ou nitrés et halogénés
• B27K 3/50 - Mélanges de différents agents d'imprégnation organiques
• C07C 273/00 - Préparation d'urée ou de ses dérivés, c.-à-d. de composés contenant l'un des groupes les atomes d'azote ne faisant pas partie de groupes nitro ou nitroso
• C07F 9/117 - Esters des acides phosphoriques avec des alcools cycloaliphatiques
• C08L 97/02 - Matériau lignocellulosique, p. ex. bois, paille ou bagasse
• C09K 21/00 - Substances ignifugeantes
• D06M 13/00 - Traitement des fibres, fils, filés, tissus ou articles fibreux faits de ces matières, avec des composés organiques non macromoléculairesUn tel traitement combiné avec un traitement mécanique

Abrégé

A mechanism is presented for attributing users to one or more of a plurality of sub-bands in a multiple access communications system, wherein in an initial assignment phase, a first user is selected for a sub band, for example on the basis of a user priority. Users having complementary channel gains to that of the first user are identified, and then a second sub-band user maximizing a performance metric reflecting the achieved throughput, and/or fairness across users, is selected to accompany the first user on that sub-band. The initial assignment phase may terminate once all users have been assigned to a sub-band once. After the first phase is complete, the first user for each sub-band may be the user whose achieved total throughput is furthest from a target throughput defined for that user, wherein each user is assigned to the remaining sub-band to which no first user is currently attributed offering the highest channel gain for that user. Mechanisms for determining user priority, making provisional and definitive power allocations, and performance metrics are proposed.

Classes IPC  ?

• H04L 5/00 - Dispositions destinées à permettre l'usage multiple de la voie de transmission
• H04W 52/32 - TPC des canaux de radiodiffusion ou de commande
• H04W 72/04 - Affectation de ressources sans fil
• H04W 72/10 - Affectation de ressources sans fil sur la base de critères de priorité

Abrégé

2), and each user attributed to a sub-band other than the selected sub-band. User pairs for consideration may consider all possible pairs, or may be limited to candidate pairs satisfying together, or comprising one or both users who satisfy a criterion such as channel gain, distance to a target, throughput or a combination of some or all of these factors. The power allocated to each sub-band may be attributed by a waterfilling algorithm.

Classes IPC  ?

• H04W 52/34 - Gestion du TPC, c.-à-d. partage de la quantité limitée de puissance entre les utilisateurs ou les canaux ou encore les types de données, p. ex. charge des cellules
• H04L 5/00 - Dispositions destinées à permettre l'usage multiple de la voie de transmission
• H04W 72/04 - Affectation de ressources sans fil

Abrégé

A method and system for assigning power to sub-bands in a multiple access communications system, where users are assigned iteratively to sub-bands, and at each iteration a provisional partial power budget is determined for the subset of sub-bands comprising the sub-bands to which users have been assigned in the present time slot and the sub-band under consideration in the sequence, where the fraction of the total available power determined as the provisional partial power budget corresponds to the fraction of the number of sub-bands in the subset from the total number of sub-bands to be assigned, and the provisional power allocation for the sub-band under consideration is obtained by performing a waterfilling distribution of the provisional partial power budget amongst the subset of the sub-bands, based on the channel gain of the users already assigned to sub-bands in the present time slot.

Classes IPC  ?

• H04W 52/34 - Gestion du TPC, c.-à-d. partage de la quantité limitée de puissance entre les utilisateurs ou les canaux ou encore les types de données, p. ex. charge des cellules
• H04W 52/42 - Commande de puissance d'émission [TPC Transmission power control] le TPC étant effectué dans des situations particulières dans des systèmes à diversité de temps, d'espace, de fréquence ou de polarisation
• H04W 72/044 - Affectation de ressources sans fil sur la base du type de ressources affectées
• H04W 72/542 - Critères d’affectation ou de planification des ressources sans fil sur la base de critères de qualité en utilisant la qualité mesurée ou perçue

Abrégé

2) are selected as the pair of candidate users corresponding to an extremum of the ratio between a first term reflecting the total throughput achievable by any pair of the candidate users assigned to the sub-band (s) under consideration, and a second term reflecting the known throughput achieved by that same pair of candidate users over a predetermined preceding period. Implementations include a method of determining a performance metric is presented for attributing users to one or more of a plurality of sub-bands in a multiple access communications system, wherein in an initial assignment phase for a specific sub-band, a first user is selected for that band on the basis of one or more criteria such as user priority. Then a second sub-band user maximizing or minimizing the performance metric.

Classes IPC  ?

• H04L 5/00 - Dispositions destinées à permettre l'usage multiple de la voie de transmission

Abrégé

A mechanism is presented for attributing users to one or more of a plurality of sub-bands in a multiple access communications system, in which in an initial assignment phase, a first user is selected for a sub band, for example on the basis of a user priority. Users having complementary channel gains to that of the first user are identified, and then a second sub-band user maximizing a performance metric reflecting the achieved throughput, and/or fairness across users, is selected to accompany the first user on that sub-band. The initial assignment phase may terminate once all users have been assigned to a sub-band once. After the first phase is complete, the first user for each sub- band may be the user whose achieved total throughput is furthest from a target throughput defined for that user, wherein each user is assigned to the remaining sub-band to which no first user is currently attributed offering the highest channel gain for that user. Mechanisms for determining user priority, making provisional and definitive power allocations, and performance metrics are proposed.

Classes IPC  ?

• H04L 5/00 - Dispositions destinées à permettre l'usage multiple de la voie de transmission

Abrégé

A method and system for assigning power to sub-bands in a multiple access communications system, where users are assigned iteratively to sub-bands, and at each iteration a provisional partial power budget is determined for the subset of sub-bands comprising the sub-bands to which users have been assigned in the present time slot and the sub-band under consideration in the sequence, where the fraction of the total available power determined as the provisional partial power budget corresponds to the fraction of the number of sub-bands in the subset from the total number of sub-bands to be assigned, and the provisional power allocation for the sub-band under consideration is obtained by performing a waterfilling distribution of the provisional partial power budget amongst the subset of the sub-bands, based on the channel gain of the users already assigned to sub-bands in the present time slot.

Classes IPC  ?

• H04W 52/34 - Gestion du TPC, c.-à-d. partage de la quantité limitée de puissance entre les utilisateurs ou les canaux ou encore les types de données, p. ex. charge des cellules

Abrégé

k1k2 2 ) are selected as the pair of candidate users corresponding to an extremum of the ratio between a first term reflecting the total throughput achievable by any pair of the candidate users assigned to the sub-band (s) under consideration, and a second term reflecting the known throughput achieved by that same pair of candidate users over a predetermined preceding period. Implementations include a method of determining a performance metric is presented for attributing users to one or more of a plurality of sub-bands in a multiple access communications system, in which in an initial assignment phase for a specific sub-band, a first user is selected for that band on the basis of one or more criteria such as user priority. Then a second sub-band user maximizing or minimizing the performance metric.

Classes IPC  ?

• H04L 5/00 - Dispositions destinées à permettre l'usage multiple de la voie de transmission

Abrégé

k11 k22 2 ), and each user attributed to a sub-band other than said selected sub-band. User pairs for consideration may consider all possible pairs, or may be limited to candidate pairs satisfying together, or comprising one or both users who satisfy a criterion such as channel gain, distance to a target, throughput or a combination of some or all of these factors. The power allocated to each sub-band may be attributed by a waterfilling algorithm.

Classes IPC  ?

• H04J 11/00 - Systèmes multiplex orthogonaux
• H04L 5/00 - Dispositions destinées à permettre l'usage multiple de la voie de transmission
• H04W 52/34 - Gestion du TPC, c.-à-d. partage de la quantité limitée de puissance entre les utilisateurs ou les canaux ou encore les types de données, p. ex. charge des cellules
• H04J 99/00 - Matière non prévue dans les autres groupes de la présente sous-classe

Abrégé

A mechanism for attributing users to a plurality of sub bands in a time slot t in a multiple access communications system, said method comprising assigning a combination of users to a sub band on a Proportional Fairness basis, that is to say whichever combination of users maximizes a Proportional Fairness performance metric for that channel, where the performance metric is weighted by a weighting factor reflecting the difference for that user between a target throughput and a projected throughput.

Classes IPC  ?

• H04W 28/02 - Gestion du trafic, p. ex. régulation de flux ou d'encombrement
• H04W 72/12 - Planification du trafic sans fil
• H04W 28/18 - Négociation des paramètres de télécommunication sans fil
• H04W 28/26 - Réservation de ressources
• H04B 7/06 - Systèmes de diversitéSystèmes à plusieurs antennes, c.-à-d. émission ou réception utilisant plusieurs antennes utilisant plusieurs antennes indépendantes espacées à la station d'émission
• H04L 25/02 - Systèmes à bande de base Détails
• H04W 72/04 - Affectation de ressources sans fil

Abrégé

Heterojunction structure, also referred to as a heterostructure, of semiconductor material, in particular for a high electron mobility transistor (HEMT), includes a substrate, a stack of at least three buffer layers of a same semiconductor material with a wide bandgap EG1 based on a column-III nitride, namely an unintentionally doped first buffer layer, a second buffer layer, an unintentionally doped third buffer layer, an unintentionally doped intermediate layer, and a barrier layer arranged on the intermediate layer, said barrier layer being of a semiconductor material with a wide bandgap EG2 based on a column-III nitride; the second buffer layer has constant P+ doping throughout some or all of its thickness; and the third buffer layer includes a first region which is unintentionally doped throughout its entire thickness and at least one second region adjacent to said first region with N+ doping surrounding the first region.

Classes IPC  ?

• H01L 29/66 - Types de dispositifs semi-conducteurs
• H01L 29/10 - Corps semi-conducteurs caractérisés par les formes, les dimensions relatives, ou les dispositions des régions semi-conductrices avec des régions semi-conductrices connectées à une électrode ne transportant pas le courant à redresser, amplifier ou commuter, cette électrode faisant partie d'un dispositif à semi-conducteur qui comporte trois électrodes ou plus
• H01L 29/778 - Transistors à effet de champ avec un canal à gaz de porteurs de charge à deux dimensions, p.ex. transistors à effet de champ à haute mobilité électronique HEMT
• H01L 29/20 - Corps semi-conducteurs caractérisés par les matériaux dont ils sont constitués comprenant, à part les matériaux de dopage ou autres impuretés, uniquement des composés AIIIBV

Abrégé

Power allocation in NOMA systems for example on the basis Proportional Fairness calculations depends on knowledge of user throughput on a specified sub-band, which implies that users have already been allocated to particular sub-bands. Meanwhile, maximum throughput can generally be achieved where there is the greatest possible difference in transmission power for the users on a given sub-band, so that optimal allocation of users to sub-bands requires knowledge of the power available for each user. A mechanism is proposed based on iteratively applying a waterfilling algorithm to distribute power across a progressive subset of sub-bands to provisionally distribute the power budget across that subset of sub-bands, where at each iteration the water filling algorithm is carried out for each possible combination of users assignable to the newly considered sub-band using a floor for that sub band proportional to the reciprocal of the square of the highest channel gain value of any user in that combination, and calculating a throughput for that combination with the corresponding power attribution, whereby the combination retained for the next iteration (with an additional sub-band) is whichever gives the highest throughput. This process is thus repeated until users are assigned to all sub-bands, whereupon power allocations from the last iteration are definitive.

Classes IPC  ?

• H04W 52/22 - Commande de puissance d'émission [TPC Transmission power control] le TPC étant effectué selon des paramètres spécifiques tenant compte des informations ou des instructions antérieures
• H04W 52/34 - Gestion du TPC, c.-à-d. partage de la quantité limitée de puissance entre les utilisateurs ou les canaux ou encore les types de données, p. ex. charge des cellules
• H04W 72/04 - Affectation de ressources sans fil
• H04W 52/24 - Commande de puissance d'émission [TPC Transmission power control] le TPC étant effectué selon des paramètres spécifiques utilisant le rapport signal sur parasite [SIR Signal to Interference Ratio] ou d'autres paramètres de trajet sans fil
• H04W 52/26 - Commande de puissance d'émission [TPC Transmission power control] le TPC étant effectué selon des paramètres spécifiques utilisant le débit de transmission ou la qualité de service [QoS Quality of Service]
• H04W 52/36 - Commande de puissance d'émission [TPC Transmission power control] utilisant les limitations de la quantité totale de puissance d'émission disponible avec une plage ou un ensemble discrets de valeurs, p. ex. incrément, variation graduelle ou décalages

Abrégé

A heterojunction structure of semiconductor material, for a high electron mobility transistor includes a substrate, a buffer layer, arranged on the substrate, of a large bandgap semiconductor material, based on a nitride from column III, where the buffer layer is not intentionally doped with n-type carriers, a barrier layer arranged above the buffer layer, of a large bandgap semiconductor material based on a nitride from column III, where the width of the bandgap of the barrier layer is less than the width of the bandgap of the buffer layer. The heterojunction structure additionally comprises an intentionally doped area, of a material based on a nitride from column III identical to the material of the buffer layer, in a plane parallel to the plane of the substrate and a predefined thickness along a direction orthogonal to the plane of the substrate, where the area is comprised in the buffer layer.

Classes IPC  ?

• H01L 29/66 - Types de dispositifs semi-conducteurs
• H01L 21/338 - Transistors à effet de champ à grille Schottky
• H01L 29/778 - Transistors à effet de champ avec un canal à gaz de porteurs de charge à deux dimensions, p.ex. transistors à effet de champ à haute mobilité électronique HEMT
• H01L 29/10 - Corps semi-conducteurs caractérisés par les formes, les dimensions relatives, ou les dispositions des régions semi-conductrices avec des régions semi-conductrices connectées à une électrode ne transportant pas le courant à redresser, amplifier ou commuter, cette électrode faisant partie d'un dispositif à semi-conducteur qui comporte trois électrodes ou plus
• H01L 29/20 - Corps semi-conducteurs caractérisés par les matériaux dont ils sont constitués comprenant, à part les matériaux de dopage ou autres impuretés, uniquement des composés AIIIBV

Abrégé

Semiconductor heterojunction structure, i.e. what is also referred to as a heterostructure, especially for a high electron mobility transistor (HEMT), comprising a substrate (4) and a stack of at least three buffer layers made of the same semiconductor of wide bandgap EG1 based on a nitride of column, namely an unintentionally doped first buffer layer (6), a second buffer layer (8) and an unintentionally doped third buffer layer (10), an unintentionally doped intermediate layer (11) and a barrier layer (12) that is placed on the intermediate layer (11), said barrier layer (12) being made of a semiconductor of wide bandgap EG2 based on a nitride of column III; the second buffer layer (8) has a constant p+-type dopant concentration through all or some of its thickness; and the third buffer layer (10) has a first unintentionally doped region (16) right through its thickness and at least one second region (18) adjacent said first region with an n+ doping surrounding the first region (16).

Classes IPC  ?

• H01L 29/778 - Transistors à effet de champ avec un canal à gaz de porteurs de charge à deux dimensions, p.ex. transistors à effet de champ à haute mobilité électronique HEMT
• H01L 21/338 - Transistors à effet de champ à grille Schottky
• H01L 21/336 - Transistors à effet de champ à grille isolée
• H01L 29/10 - Corps semi-conducteurs caractérisés par les formes, les dimensions relatives, ou les dispositions des régions semi-conductrices avec des régions semi-conductrices connectées à une électrode ne transportant pas le courant à redresser, amplifier ou commuter, cette électrode faisant partie d'un dispositif à semi-conducteur qui comporte trois électrodes ou plus
• H01L 29/20 - Corps semi-conducteurs caractérisés par les matériaux dont ils sont constitués comprenant, à part les matériaux de dopage ou autres impuretés, uniquement des composés AIIIBV

Abrégé

A heterojunction structure, also called a hetero-structure, made from a semiconductor material, in particular for a high electron mobility transistor (HEMT) comprising a substrate, a buffer layer disposed on the substrate made from a wide-bandgap semiconductor material made from a column-III nitride, said buffer layer (1) being unintentionally doped with N-type carriers, a barrier layer, disposed on top of the buffer layer, made from a wide-bandgap Eg2 semiconductor material made from a column-III nitride, the width of bandgap Eg2 of the barrier layer being less than the width of bandgap Eg1 of the buffer layer. The heterojunction structure further comprises an intentionally doped area, made from a column-III material identical to the material of the buffer layer, in a plane parallel to the plane of the substrate and having a thickness defined in a direction orthogonal to the plane of the substrate, said area being included in the buffer layer.

Classes IPC  ?

• H01L 29/778 - Transistors à effet de champ avec un canal à gaz de porteurs de charge à deux dimensions, p.ex. transistors à effet de champ à haute mobilité électronique HEMT
• H01L 29/10 - Corps semi-conducteurs caractérisés par les formes, les dimensions relatives, ou les dispositions des régions semi-conductrices avec des régions semi-conductrices connectées à une électrode ne transportant pas le courant à redresser, amplifier ou commuter, cette électrode faisant partie d'un dispositif à semi-conducteur qui comporte trois électrodes ou plus