The Second Transmembrane Domain of P2X7 Contributes to Dilated Pore Formation

Activation of the purinergic receptor P2X7 leads to the cellular permeability of low molecular weight cations. To determine which domains of P2X7 are necessary for this permeability, we exchanged either the C-terminus or portions of the second transmembrane domain (TM2) with those in P2X1 or P2X4. Replacement of the C-terminus of P2X7 with either P2X1 or P2X4 prevented surface expression of the chimeric receptor. Similarly, chimeric P2X7 containing TM2 from P2X1 or P2X4 had reduced surface expression and no permeability to cationic dyes. Exchanging the N-terminal 10 residues or C-terminal 14 residues of the P2X7 TM2 with the corresponding region of P2X1 TM2 partially restored surface expression and limited pore permeability. To further probe TM2 structure, we replaced single residues in P2X7 TM2 with those in P2X1 or P2X4. We identified multiple substitutions that drastically changed pore permeability without altering surface expression. Three substitutions (Q332P, Y336T, and Y343L) individually reduced pore formation as indicated by decreased dye uptake and also reduced membrane blebbing in response to ATP exposure. Three others substitutions, V335T, S342G, and S342A each enhanced dye uptake, membrane blebbing and cell death. Our results demonstrate a critical role for the TM2 domain of P2X7 in receptor function, and provide a structural basis for differences between purinergic receptors. © 2013 Sun et al

Linear Collider Physics Resource Book for Snowmass 2001, 3: Studies of Exotic and Standard Model Physics

This Resource Book reviews the physics opportunities of a next-generation e+e- linear collider and discusses options for the experimental program. Part 3 reviews the possible experiments on that can be done at a linear collider on strongly coupled electroweak symmetry breaking, exotic particles, and extra dimensions, and on the top quark, QCD, and two-photon physics. It also discusses the improved precision electroweak measurements that this collider will make available.This Resource Book reviews the physics opportunities of a next-generation e+e- linear collider and discusses options for the experimental program. Part 3 reviews the possible experiments on that can be done at a linear collider on strongly coupled electroweak symmetry breaking, exotic particles, and extra dimensions, and on the top quark, QCD, and two-photon physics. It also discusses the improved precision electroweak measurements that this collider will make available

Технологические решения для строительства эксплуатационной наклонно-направленной скважины глубиной 2950 метров Федюшкинском нефтяном месторождении (Томская область)

Объектом исследования является (ются) Федюшкинское месторождение. Цель работы – технологические решения на строительство эксплуатационной наклонно направленной скважины глубиной 2950 метров на Федюшкинском нефтяном месторождении (Томской облости). В процессе исследования проводились технологические расчеты по проектированию скважины, рассмотрена специальная часть совершенствование процесса ремонта скважин с применением эжектора. В результате исследованияобоснован и рассчитан профиля скважины, спроектирован процесс закачивания скважины.The object of study is (are) fedoskinskoe field. Purpose – technological decisions on construction operation of the inclined directional well with a depth of 2950 meters on Fedyushkinskoye oil field (Tomsk region). During the study, carried out process calculations for the design of well considered by the special part of improving the process of repair of wells with the use of the ejector. The study justified and designed well profile, design of the process of injection wells, considered the technology of repair of wells with the use of the ejector