RESUMO
We present the first Ge-based constraints on sub-MeV/c^{2} dark matter (DM) particles interacting with electrons using a 33.4 g Ge cryogenic detector with a 0.53 electron-hole pair (rms) resolution, operated underground at the Laboratoire Souterrain de Modane. Competitive constraints are set on the DM-electron scattering cross section, as well as on the kinetic mixing parameter of dark photons down to 1 eV/c^{2}. In particular, the most stringent limits are set for dark photon DM in the 6 to 9 eV/c^{2} range. These results demonstrate the high relevance of Ge cryogenic detectors for the search of DM-induced eV-scale electron signals.
RESUMO
Molecular weight and optical properties of the lipoprotein B, the main antigen produced by the parasite in sheep hydatid fluid, have been determined. By sedimentation equilibrium studies, its molecular weight has been found equal to 120,000. Circular dichroism and optical rotatory dispersion spectra are consistent with an alpha-helix content of about 50%, and this ordered structure is not completely destroyed by dissociation in guanidinium choloride. The ORD spectrum is discussed in relation to the biological function of the lipoprotein antigen.
Assuntos
Antígenos/análise , Echinococcus/imunologia , Lipoproteínas/análise , Animais , Cromatografia em Gel , Dicroísmo Circular , Equinococose/imunologia , Concentração de Íons de Hidrogênio , Lipoproteínas/isolamento & purificação , Peso Molecular , Dispersão Óptica Rotatória , Conformação Proteica , Ovinos , UltracentrifugaçãoAssuntos
Fosfotransferases , Animais , Arginina , Fenômenos Químicos , Química , Dicroísmo Circular , Creatina Quinase , Crustáceos/enzimologia , Nitratos , Coelhos , Hidróxido de Sódio , TirosinaAssuntos
Fosfotransferases , Trifosfato de Adenosina , Alcanos , Animais , Arginina , Fenômenos Químicos , Química , Crustáceos , Glicóis , Concentração de Íons de Hidrogênio , Nitratos , Dispersão Óptica Rotatória , Desnaturação Proteica , Espectrofotometria , Análise Espectral , Tirosina , Ultracentrifugação , ViscosidadeAssuntos
Actinas , Actinas/isolamento & purificação , Animais , Cristalização , Microscopia de Contraste de Fase , Peso Molecular , Músculos , CoelhosAssuntos
Antígenos/isolamento & purificação , Equinococose/imunologia , Echinococcus/imunologia , Lipoproteínas/isolamento & purificação , Ágar , Animais , Antígenos/análise , Cromatografia em Gel , Eletroforese , Géis , Imunoeletroforese , Isótopos de Iodo , Lipoproteínas/análise , Métodos , Peso Molecular , OvinosRESUMO
Human blood platelet actin was purified using 30% sucrose to extract actomyosin and potassium iodide to dissociate actomyosin and to depolymerize actin. Pure actin thus obtained resembles skeletic muscle actin in its polymerization properties, CD spectra and ability to activate myosin myosin Mg2+-ATPase. Isoelectric focusing gel analysis shows that human blood platelet actin exists in beta and gamma forms. The ratio of beta to gamma forms is of 5 in purified actin, in whole cell extract and in all the fractions studied.