Measurements of the Generalized Electric and Magnetic Polarizabilities of the Proton at Low Q2 Using the VCS Reaction

The mean square polarizability radii of the proton have been measured for the first time in a virtual Compton scattering experiment performed at the MIT-Bates out-of-plane scattering facility. Response functions and polarizabilities obtained from a dispersion analysis of the data at Q2=0.06 GeV2/c2 are in agreement with O(p3) heavy baryon chiral perturbation theory. The data support the dominance of mesonic effects in the polarizabilities, and the increase of beta with increasing Q2 is evidence for the cancellation of long-range diamagnetism by short-range paramagnetism from the pion cloud

The Charge Form Factor of the Neutron at Low Momentum Transfer from the 2H⃗(e⃗,e′n)p^{2}\vec{\rm H}(\vec{\rm e},{\rm e}'{\rm n}){\rm p} Reaction

We report new measurements of the neutron charge form factor at low momentum transfer using quasielastic electrodisintegration of the deuteron. Longitudinally polarized electrons at an energy of 850 MeV were scattered from an isotopically pure, highly polarized deuterium gas target. The scattered electrons and coincident neutrons were measured by the Bates Large Acceptance Spectrometer Toroid (BLAST) detector. The neutron form factor ratio $G^{n}_{E}/G^{n}_{M}$ was extracted from the beam-target vector asymmetry $A_{ed}^{V}$ at four-momentum transfers $Q^{2}=0.14$, 0.20, 0.29 and 0.42 (GeV/c)$^{2}$.Comment: 5 pages, 3 figures, submitted to Phys. Rev. Let

Investigation of the conjectured nucleon deformation at low momentum transfer

We report new precise H$(e,e^\prime p)\pi^0$ measurements at the $\Delta(1232)$ resonance at $Q^2= 0.127$ (GeV/c)$^2$ using the MIT/Bates out-of-plane scattering (OOPS) facility. The data reported here are particularly sensitive to the transverse electric amplitude ($E2$) of the $\gamma^* N\to\Delta$ transition. Analyzed together with previous data yield precise quadrupole to dipole amplitude ratios $EMR = (-2.3 \pm 0.3_{stat+sys} \pm 0.6_{model})$ and $CMR = (-6.1 \pm 0.2_{stat+sys}\pm 0.5_{model})$ and for $M^{3/2}_{1+} = (41.4 \pm 0.3_{stat+sys}\pm 0.4_{model})(10^{-3}/m_{\pi^+})$. They give credence to the conjecture of deformation in hadronic systems favoring, at low $Q^2$, the dominance of mesonic effects.Comment: 4 pages, 1figur

Measurement of the proton electric to magnetic form factor ratio from \vec ^1H(\vec e, e'p)

We report the first precision measurement of the proton electric to magnetic form factor ratio from spin-dependent elastic scattering of longitudinally polarized electrons from a polarized hydrogen internal gas target. The measurement was performed at the MIT-Bates South Hall Ring over a range of four-momentum transfer squared $Q^2$ from 0.15 to 0.65 (GeV/c)$^2$. Significantly improved results on the proton electric and magnetic form factors are obtained in combination with previous cross-section data on elastic electron-proton scattering in the same $Q^2$ region.Comment: 4 pages, 2 figures, submitted to PR

Spin chemistry investigation of peculiarities of photoinduced electron transfer in donor-acceptor linked system

Photoinduced intramolecular electron transfer in linked systems, (R,S)- and (S,S)-naproxen-N-methylpyrrolidine dyads, has been studied by means of spin chemistry methods [magnetic field effect and chemically induced dynamic nuclear polarization (CIDNP)]. The relative yield of the triplet state of the dyads in different magnetic field has been measured, and dependences of the high-field CIDNP of the N-methylpyrrolidine fragment on solvent polarity have been investigated. However, both (S,S)- and (R,S)-enantiomers demonstrate almost identical CIDNP effects for the entire range of polarity. It has been demonstrated that the main peculiarities of photoprocesses in this linked system are connected with the participation of singlet exciplex alongside with photoinduced intramolecular electron transfer in chromophore excited state quenching.This work was supported by the grants 08-03-00372 and 11-03-01104 of the Russian Foundation for Basic Research, and the grant of Priority Programs of the Russian Academy of Sciences, nr. 5.1.5.Magin, I.; Polyakov, N.; Khramtsova, E.; Kruppa, A.; Stepanov, A.; Purtov, P.; Leshina, T.... (2011). Spin chemistry investigation of peculiarities of photoinduced electron transfer in donor-acceptor linked system. Applied Magnetic Resonance. 41(2-4):205-220. https://doi.org/10.1007/s00723-011-0288-3S205220412-4J.S. Park, E. Karnas, K. Ohkubo, P. Chen, K.M. Kadish, S. Fukuzumi, C.W. Bielawski, T.W. Hudnall, V.M. Lynch, J.L. Sessler, Science 329, 1324–1327 (2010)S.Y. Reece, D.G. Nocera, Annu. Rev. Biochem. 78, 673–699 (2009)M.S. Afanasyeva, M.B. Taraban, P.A. Purtov, T.V. Leshina, C.B. Grissom, J. Am. Chem. Soc. 128, 8651–8658 (2006)M.A. Fox, M. Chanon, in Photoinduced Electron Transfer. C: Photoinduced Electron Transfer Reactions: Organic Substrates (Elsevier, New York, 1988), p. 754P.J. Hayball, R.L. Nation, F. Bochner, Chirality 4, 484–487 (1992)N. Suesa, M.F. Fernandez, M. Gutierrez, M.J. Rufat, E. Rotllan, L. Calvo, D. Mauleon, G. Carganico, Chirality 5, 589–595 (1993)A.M. Evans, J. Clin. Pharmacol. 36, 7–15 (1996)Y. Inoue, T. Wada, S. Asaoka, H. Sato, J.-P. Pete, Chem Commun. 4, 251–259 (2000)T. Yorozu, K. Hayashi, M. Irie, J. Am. Chem. Soc. 103, 5480–5548 (1981)N.J. Turro, in Modern Molecular Photochemistry (Benjamin/Cummings, San Francisco, 1978)K.M. Salikhov, Y.N. Molin, R.Z. Sagdeev, A.L. Buchachenko, in Spin Polarization and Magnetic Field Effects in Radical Reactions (Akademiai Kiado, Budapest, 1984), p. 419E.A. Weiss, M.A. Ratner, M.R. Wasielewski, J. Phys. Chem. A 107, 3639–3647 (2003)A.S. Lukas, P.J. Bushard, E.A. Weiss, M.R. Wasielewski, J. Am. Chem. Soc. 125, 3921–3930 (2003)R. Nakagaki, K. Mutai, M. Hiramatsu, H. Tukada, S. Nakakura, Can. J. Chem. 66, 1989–1996 (1988)M.C. Jim′enez, U. Pischel, M.A. Miranda, J. Photochem. Photobiol. C Photochem. Rev. 8, 128–142 (2007)S. Abad, U. Pischel, M.A. Miranda, Photochem. Photobiol. Sci. 4, 69–74 (2005)U. Pischel, S. Abad, L.R. Domingo, F. Bosca, M.A. Miranda, Angew. Chem. Int. Ed. 42, 2531–2534 (2003)G.L. Closs, R.J. Miller, J. Am. Chem. Soc. 101, 1639–1641 (1979)G.L. Closs, R.J. Miller, J. Am. Chem. Soc. 103, 3586–3588 (1981)M. Goez, Chem. Phys. Lett. 188, 451–456 (1992)I.F. Molokov, Y.P. Tsentalovich, A.V. Yurkovskaya, R.Z. Sagdeev, J. Photochem. Photobiol. A 110, 159–165 (1997)U. Pischel, S. Abad, M.A. Miranda, Chem. Commun. 9, 1088–1089 (2003)H. Hayashi, S. Nagakura, Bull. Chem. Soc. Jpn. 57, 322–328 (1984)Y. Sakaguchi, H. Hayashi, S. Nagakura, Bull. Chem. Soc. Jpn. 53, 39–42 (1980)H. Yonemura, H. Nakamura, T. Matsuo, Chem. Phys. Lett. 155, 157–161 (1989)N. Hata, M. Hokawa, Chem. Lett. 10, 507–510 (1981)M. Shiotani, L. Sjoeqvist, A. Lund, S. Lunell, L. Eriksson, M.B. Huang, J. Phys. Chem. 94, 8081–8090 (1990)E. Schaffner, H. Fischer, J. Phys. Chem. 100, 1657–1665 (1996)Y. Mori, Y. Sakaguchi, H. Hayashi, Chem. Phys. Lett. 286, 446–451 (1998)I.M. Magin, A.I. Kruppa, P.A. Purtov, Chem. Phys. 365, 80–84 (2009)K.K. Barnes, Electrochemical Reactions in Nonaqueous Systems (M. Dekker, New York, 1970), p. 560J. Bargon, J. Am. Chem. Soc. 99, 8350–8351 (1977)M. Goez, I. Frisch, J. Phys. Chem. A 106, 8079–8084 (2002)A.K. Chibisov, Russ. Chem. Rev. 50, 615–629 (1981)J. Goodman, K. Peters, J. Am. Chem. Soc. 107, 1441–1442 (1985)H. Cao, Y. Fujiwara, T. Haino, Y. Fukazawa, C.-H. Tung, Y. Tanimoto, Bull. Chem. Soc. Jpn. 69, 2801–2813 (1996)P.A. Purtov, A.B. Doktorov, Chem. Phys. 178, 47–65 (1993)A.I. Kruppa, O.I. Mikhailovskaya, T.V. Leshina, Chem. Phys. Lett. 147, 65–71 (1988)M.E. Michel-Beyerle, R. Haberkorn, W. Bube, E. Steffens, H. Schröder, H.J. Neusser, E.W. Schlag, H. Seidlitz, Chem. Phys. 17, 139–145 (1976)K. Schulten, H. Staerk, A. Weller, H.-J. Werner, B. Nickel, Z. Phys. Chem. 101, 371–390 (1976)K. Gnadig, K.B. Eisenthal, Chem. Phys. Lett. 46, 339–342 (1977)T. Nishimura, N. Nakashima, N. Mataga, Chem. Phys. Lett. 46, 334–338 (1977)M.G. Kuzmin, I.V. Soboleva, E.V. Dolotova, D.N. Dogadkin, High Eng. Chem. 39, 86–96 (2005

Поиск протеомных маркеров рака молочной железы в составе суммарных экзосом крови

To improve early detection of cancer, search for tumor markers in biological fluids is of great importance. A significant portion of exosomes is associated with the surface of blood cells, however, the protein spectrum of such exosomes has not been previously studied. The use of total blood exosomes (plasma exosomes and exosomes associated with the surface of blood cells) can not only significantly increase the specificity and sensitivity of existing methods, but also suggest new tumor markers for liquid biopsy.Objective. Search for candidate protein tumor markers of breast cancer by comparing 2D-proteomic maps of total blood exosomes of healthy females (HFs) and breast cancer patients (BCPs).Methods. Exosomes were isolated from plasma and total blood of HFs and BCPs by ultrafiltration followed by ultracentrifugation and were characterized using transmission electron microscopy (TEM) and immunocytochemistry. Protein concentration in exosomes was determined using the NanoOrange Protein Quantitation kit (Invitrogen) commercial kit. Proteomes of exosomes were studied using 2d electrophoresis followed by protein identification by mass spectrometry.Results. Highly purified samples of vesicles from plasma and total blood of no more than 100 nm in size were obtained, on the surface of which markers specific for exosomes were detected by monoclonal antibodies CD9. A comparative analysis of the proteomic maps of exosomal proteins of the HFs and BCPs obtained by 2D-electrophoresis allowed us to establish significant differences in the expression level and protein set in normal and pathological conditions. The 11 proteomic markers of breast cancer were identified by the peptide fingerprint method, of which LRG и у-chain FGB were detected in the composition of exosomes for the first time (according to the Exocarta database). Using MALDI-TOF mass spectrometry, 99 proteins were identified in the exosome preparations of the blood of HFs and BCPs, of which 35% were detected in the composition of the exosomes for the first time (according to the Exocarta database). 17 (53%) proteins associated with breast cancer were detected in total blood exosomes of cancer patients.Conclusion. The results obtained indicate that total blood exosomes are a promising source of diagnostic material for the search for proteomic markers of breast cancer. The identified proteomic tumor markers require further validation.Актуальность. Актуальной задачей повышения эффективности ранней диагностики онкологических заболеваний является поиск высокоспецифичных опухолевых маркеров в биологических жидкостях организма. Значительная часть экзосом ассоциирована с поверхностью форменных элементов крови, однако белковый спектр таких экзосом ранее не исследовался. использование суммарных экзосом крови (экзосом плазмы и экзосом, ассоциированных с поверхностью клеток крови) может не только значительно повысить специфичность и чувствительность существующих методов, но и выявить новые онкомаркеры для жидкостной биопсии.Цель работы - поиск кандидатных белковых онкомаркеров рака молочной железы (РМЖ) путем сравнения 2D-протеомных карт суммарных экзосом крови здоровых женщин и больных РМЖ.Материал и методы. Экзосомы выделены из крови здоровых женщин и больных РМЖ методом ультрафильтрации с последующим ультрацентрифугированием и охарактеризованы при помощи трансмиссионной электронной микроскопии и иммуноцитохимии. Концентрацию белка в экзосомах определяли при помощи коммерческого набора NanoOrange Protein Quantitation kit (Invitrogen). Протеом экзосом исследован с помощью 2D-электрофореза с последующей идентификацией белков методом масс-спектрометрии.Результаты. Получены высокоочищенные препараты микровезикул суммарной крови размером не более 100 нм, на поверхности которых иммуноцитохимически были выявлены специфические для экзосом маркеры (CD63, CD9 и CD24). Сравнительный анализ протеомных карт экзосомальных белков здоровых женщин и больных РМЖ, полученных с помощью 2D-электрофореза, позволил установить значимые различия в уровне экспрессии и наборе белков в норме и патологии. Методом пептидного фингерпринта идентифицировано 11 перспективных протеомных маркеров РМЖ, из них LRG и у-цепь FGB выявлены в составе экзосом впервые (согласно базе Exocarta). Методом MALDI-TOF масс-спектрометрии идентифицировано 99 белков в препаратах экзосом крови здоровых женщин и больных РМЖ, из них 35 % выявлены в составе экзосом впервые (согласно базе Exocarta). В составе суммарных экзосом крови онкологических больных выявлено 17 (53 %) белков, ассоциированных с РМЖ.Заключение. Полученные результаты свидетельствуют о том, что суммарные экзосомы крови являются перспективным источником диагностического материала для поиска протеомных маркеров РМЖ. идентифицированные протеомные онкомаркеры в их составе требуют дальнейшей валидации