Photodynamic Therapy in Complex Therapy of Retroperitoneal Tumors in Children

During the period from 2009 to 2021, 93 patients aged 0–11 years (48 boys and 45 girls) with retroperitoneal tumors were treated. There were 66 patients with nephroblastoma and 27 patients with adrenal neuroblastoma among them. As per treatment strategies, the patients were separated into two groups: the control group and the study group. The control group (comparison) received therapy according to the protocols, whereas the study group consisted of patients who received photodynamic therapy (PDT) in addition to the standard treatment. The control group consists of 47 patients with retroperitoneal tumors, including 35 patients with nephroblastoma and 12 patients with adrenal neuroblastoma. The study group included 46 children: 31 patients with nephroblastoma and 15 patients with adrenal neuroblastoma. The 5-year survival rate in the control group was 74.5%, and it was 91.3% in the study group (p = 0.030). Recurrent tumors developed in 14.9% of the patients in the control group, while in the study group, relapse occurred in 8.7% of the patients (p = 0.357). The PDT used in this study for treatment of retroperitoneal tumors improves the results of surgical treatment. It also appreciably increases the survival rate of patients with retroperitoneal tumors. Overall, PDT is a hopeful antitumor approach and can be effectively used in the complex therapy of retroperitoneal tumors in children

Time-dependent perturbations in two-dimensional String Black Holes

We discuss time-dependent perturbations (induced by matter fields) of a black-hole background in tree-level two-dimensional string theory. We analyse the linearized case and show the possibility of having black-hole solutions with time-dependent horizons. The latter exist only in the presence of time-dependent `tachyon' matter fields, which constitute the only propagating degrees of freedom in two-dimensional string theory. For real tachyon field configurations it is not possible to obtain solutions with horizons shrinking to a point. On the other hand, such a possibility seems to be realized in the case of string black-hole models formulated on higher world-sheet genera. We connect this latter result with black hole evaporation/decay at a quantum level.}Comment: 11 pages, two figures,UA-NPPS.9/92; CERN-TH.6671/9

A Coupled-Cluster Formulation of Hamiltonian Lattice Field Theory: The Non-Linear Sigma Model

We apply the coupled cluster method (CCM) to the Hamiltonian version of the latticised O(4) non-linear sigma model. The method, which was initially developed for the accurate description of quantum many-body systems, gives rise to two distinct approximation schemes. These approaches are compared with each other as well as with some other Hamiltonian approaches. Our study of both the ground state and collective excitations leads to indications of a possible chiral phase transition as the lattice spacing is varied.Comment: 44 Pages, 14 figures. Uses Latex2e, graphicx, amstex and geometry package

The Origin of Space-Time as WW Symmetry Breaking in String Theory

Physics in the neighbourhood of a space-time metric singularity is described by a world-sheet topological gauge field theory which can be represented as a twisted $N=2$ superconformal Wess-Zumino model with a $W_{1+\infty} \otimes W_{1+\infty}$ bosonic symmetry. The measurable $W$-hair associated with the singularity is associated with Wilson loop integrals around gauge defects. The breaking of $W_{1+\infty}$ $\otimes$ $W_{1+\infty}$ $\rightarrow$ $W_{1+\infty}$ is associated with expectation values for open Wilson lines that make the metric non-singular away from the singularity. This symmetry breaking is accompanied by massless discrete `tachyon' states that appear as leg poles in $S$-matrix elements. The triviality of the $S$-matrix in the high-energy limit of the $c=1$ string model, after renormalisation by the leg pole factors, is due to the restoration of double $W$-symmetry at the singularity.Comment: 13 page

String Theory Modifies Quantum Mechanics

We argue that the light particles in string theory obey an effective quantum mechanics modified by the inclusion of a quantum-gravitational friction term, induced by unavoidable couplings to unobserved massive string states in the space-time foam. This term is related to the $W$-symmetries that couple light particles to massive solitonic string states in black hole backgrounds, and has a formal similarity to simple models of environmental quantum friction. It increases apparent entropy, and may induce the wave functions of macroscopic systems to collapse.Comment: 18 pages, CERN-6595/9

Abelian Magnetic Monopole Dominance in Quark Confinement

We prove Abelian magnetic monopole dominance in the string tension of QCD. Abelian and monopole dominance in low energy physics of QCD has been confirmed for various quantities by recent Monte Carlo simulations of lattice gauge theory. In order to prove this dominance, we use the reformulation of continuum Yang-Mills theory in the maximal Abelian gauge as a deformation of a topological field theory of magnetic monopoles, which was proposed in the previous article by the author. This reformulation provides an efficient way for incorporating the magnetic monopole configuration as a topological non-trivial configuration in the functional integral. We derive a version of the non-Abelian Stokes theorem and use it to estimate the expectation value of the Wilson loop. This clearly exhibits the role played by the magnetic monopole as an origin of the Berry phase in the calculation of the Wilson loop in the manifestly gauge invariant manner. We show that the string tension derived from the diagonal (abelian) Wilson loop in the topological field theory (studied in the previous article) converges to that of the full non-Abelian Wilson loop in the limit of large Wilson loop. Therefore, within the above reformulation of QCD, this result (together with the previous result) completes the proof of quark confinement in QCD based on the criterion of the area law of the full non-Abelian Wilson loop.Comment: 33 pages, Latex, no figures, version accepted for publication in Phys. Rev. D (additions of sec. 4.5 and references, and minor changes

Low field photo-CIDNP in the intramolecular electron transfer in naproxen-pyrrolidine dyads

[EN] Photoinduced processes with partial (exciplex) and full charge transfer in donor-acceptor systems are of interest because they are frequently used for modeling drug-protein binding. Low field photo-CIDNP (chemically induced dynamic nuclear polarization) for these processes in dyads, including the drug, (S)-and (R)-naproxen and (S)-N-methyl pyrrolidine in solutions with strong and weak permittivity have been measured. The dramatic influence of solvent permittivity on the field dependence of the N-methyl pyrrolidine H-1 CIDNP effects has been found. The field dependences of both (R, S)-and (S, S)-dyads in a polar medium are the curves with a single extremum in the area of the S-T+ terms intersection. Moreover, the CIDNP field dependences of the same protons measured in a low polar medium present curves with several extrema. The shapes of the experimental CIDNP field dependence with two extrema have been described using the Green function approach for the calculation of the CIDNP effects in the system without electron exchange interactions. The article discusses the possible causes of the differences between the CIDNP field dependence detected in a low-permittivity solvent with the strong Coulomb interactions and in a polar solvent.This study was supported by the grant 14-03-00-192 of the Russian Foundation of Basic Research. The authors are also deeply grateful to Professor Hans-Martin Vieth for the given opportunity to conduct experiments on his unique equipment.Magin, I.; Polyakov, N.; Kruppa, AI.; Purtov, P.; Leshina, TV.; Kiryutin, AS.; Miranda Alonso, MÁ.... (2016). Low field photo-CIDNP in the intramolecular electron transfer in naproxen-pyrrolidine dyads. Physical Chemistry Chemical Physics. 18(2):901-907. https://doi.org/10.1039/C5CP04233JS901907182Reece, S. Y., & Nocera, D. G. (2009). Proton-Coupled Electron Transfer in Biology: Results from Synergistic Studies in Natural and Model Systems. Annual Review of Biochemistry, 78(1), 673-699. doi:10.1146/annurev.biochem.78.080207.092132Richert, S., Rosspeintner, A., Landgraf, S., Grampp, G., Vauthey, E., & Kattnig, D. R. (2013). Time-Resolved Magnetic Field Effects Distinguish Loose Ion Pairs from Exciplexes. Journal of the American Chemical Society, 135(40), 15144-15152. doi:10.1021/ja407052tAich, S., & Basu, S. (1998). Magnetic Field Effect: A Tool for Identification of Spin State in a Photoinduced Electron-Transfer Reaction. The Journal of Physical Chemistry A, 102(4), 722-729. doi:10.1021/jp972264mVayá, I., Pérez-Ruiz, R., Lhiaubet-Vallet, V., Jiménez, M. C., & Miranda, M. A. (2010). Drug–protein interactions assessed by fluorescence measurements in the real complexes and in model dyads. Chemical Physics Letters, 486(4-6), 147-153. doi:10.1016/j.cplett.2009.12.091Werner, U., & Staerk, H. (1995). Magnetic Field Effect in the Recombination Reaction of Radical Ion Pairs: Dependence on Solvent Dielectric Constant. The Journal of Physical Chemistry, 99(1), 248-254. doi:10.1021/j100001a038Kattnig, D. R., Rosspeintner, A., & Grampp, G. (2008). Fully Reversible Interconversion between Locally Excited Fluorophore, Exciplex, and Radical Ion Pair Demonstrated by a New Magnetic Field Effect. Angewandte Chemie International Edition, 47(5), 960-962. doi:10.1002/anie.200703488Kattnig, D. R., Rosspeintner, A., & Grampp, G. (2011). Magnetic field effects on exciplex-forming systems: the effect on the locally excited fluorophore and its dependence on free energy. Phys. Chem. Chem. Phys., 13(8), 3446-3460. doi:10.1039/c0cp01517bVayá, I., Lhiaubet-Vallet, V., Jiménez, M. C., & Miranda, M. A. (2014). Photoactive assemblies of organic compounds and biomolecules: drug–protein supramolecular systems. Chem. Soc. Rev., 43(12), 4102-4122. doi:10.1039/c3cs60413fPolyakov, N. E., Taraban, M. B., & Leshina, T. V. (2004). Photo-CIDNP Study of the Interaction of Tyrosine with Nifedipine. An Attempt to Model the Binding Between Calcium Receptor and Calcium Antagonist Nifedipine¶. Photochemistry and Photobiology, 80(3), 565. doi:10.1562/0031-8655(2004)0802.0.co;2Cao, H., Fujiwara, Y., Haino, T., Fukazawa, Y., Tung, C.-H., & Tanimoto, Y. (1996). Magnetic Field Effects on Intramolecular Exciplex Fluorescence of Chain-Linked Phenanthrene andN,N-Dimethylaniline: Influence of Chain Length, Solvent, and Temperature. Bulletin of the Chemical Society of Japan, 69(10), 2801-2813. doi:10.1246/bcsj.69.2801Magin, I. M., Polyakov, N. E., Khramtsova, E. A., Kruppa, A. I., Tsentalovich, Y. P., Leshina, T. V., … Marin, M. L. (2011). Spin effects in intramolecular electron transfer in naproxen-N-methylpyrrolidine dyad. Chemical Physics Letters, 516(1-3), 51-55. doi:10.1016/j.cplett.2011.09.057Khramtsova, E. A., Plyusnin, V. F., Magin, I. M., Kruppa, A. I., Polyakov, N. E., Leshina, T. V., … Miranda, M. A. (2013). Time-Resolved Fluorescence Study of Exciplex Formation in Diastereomeric Naproxen–Pyrrolidine Dyads. The Journal of Physical Chemistry B, 117(50), 16206-16211. doi:10.1021/jp4083147Magin, I. M., Purtov, P. A., Kruppa, A. I., & Leshina, T. V. (2005). Peculiarities of Magnetic and Spin Effects in a Biradical/Stable Radical Complex (Three-Spin System). Theory and Comparison with Experiment. The Journal of Physical Chemistry A, 109(33), 7396-7401. doi:10.1021/jp051115ySubramanian, V., Bellubbi, B. S., & Sobhanadri, J. (1993). Dielectric studies of some binary liquid mixtures using microwave cavity techniques. Pramana, 41(1), 9-20. doi:10.1007/bf02847313Acemioğlu, B., Arık, M., Efeoğlu, H., & Onganer, Y. (2001). Solvent effect on the ground and excited state dipole moments of fluorescein. Journal of Molecular Structure: THEOCHEM, 548(1-3), 165-171. doi:10.1016/s0166-1280(01)00513-9Grosse, S., Gubaydullin, F., Scheelken, H., Vieth, H.-M., & Yurkovskaya, A. V. (1999). Field cycling by fast NMR probe transfer: Design and application in field-dependent CIDNP experiments. Applied Magnetic Resonance, 17(2-3), 211-225. doi:10.1007/bf03162162Magin, I. M., Polyakov, N. E., Khramtsova, E. A., Kruppa, A. I., Stepanov, A. A., Purtov, P. A., … Marin, M. L. (2011). Spin Chemistry Investigation of Peculiarities of Photoinduced Electron Transfer in Donor–Acceptor Linked System. Applied Magnetic Resonance, 41(2-4), 205-220. doi:10.1007/s00723-011-0288-3C. K. Mann and K. K.Barnes, Electrochemical Reactions in Nonaqueous Systems, M. Dekker, New York, 1970N. S. Landolt-Bornstein , Numerical Data and Functional Relationship in Science and Technology: Magnetic Properties of Free Radicals, Springer-Verlag, Berlin, 1988Grigoryants, V. M., Anisimov, O. A., & Molin, Y. N. (1982). Study of the radical-cations of triethylamine and benzene derivatives by the optical detection of the EPR spectra of radical-ion Pairs. 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V., Taraban, M. B., Sagdeev, R. Z., & Salikhov, K. M. (1986). Application of the semiclassical description of hyperfine interaction to studies of the dependence of the CIDNP effect on an external magnetic field. Chemical Physics Letters, 129(4), 357-361. doi:10.1016/0009-2614(86)80358-xShiotani, M., Sjoeqvist, L., Lund, A., Lunell, S., Eriksson, L., & Huang, M. B. (1990). An ESR and theoretical ab initio study of the structure and dynamics of the pyrrolidine radical cation and the neutral 1-pyrrolidinyl radical. The Journal of Physical Chemistry, 94(21), 8081-8090. doi:10.1021/j100384a020De Kanter, F. J. J., den Hollander, J. A., Huizer, A. H., & Kaptein, R. (1977). Biradical CIDNP and the dynamics of polymethylene chains. Molecular Physics, 34(3), 857-874. doi:10.1080/00268977700102161De Kanter, F. J. J., Kaptein, R., & Van Santen, R. A. (1977). Magnetic field dependent biradical CIDNP as a tool for the study of conformations of polymethylene chains. Chemical Physics Letters, 45(3), 575-579. doi:10.1016/0009-2614(77)80093-6Tsentalovich, Y. P., Yurkovskaya, A. V., Sagdeev, R. Z., Obynochny, A. A., Purtov, P. A., & Shargorodsky, A. A. (1989). Kinetics of nuclear polarization in the geminate recombination of biradicals. Chemical Physics, 139(2-3), 307-315. doi:10.1016/0301-0104(89)80143-0Popov, A. V., Purtov, P. A., & Yurkovskaya, A. V. (2000). Calculation of CIDNP field dependences in biradicals in the photolysis of large-ring cycloalkanones. Chemical Physics, 252(1-2), 83-95. doi:10.1016/s0301-0104(99)00293-1Magin, I. M., Shevel’kov, V. S., Obynochny, A. A., Kruppa, A. I., & Leshina, T. V. (2002). CIDNP study of the third spin effect on the singlet–triplet evolution in radical pairs. Chemical Physics Letters, 357(5-6), 351-357. doi:10.1016/s0009-2614(02)00544-4Schulten, K., & Wolynes, P. G. (1978). Semiclassical description of electron spin motion in radicals including the effect of electron hopping. The Journal of Chemical Physics, 68(7), 3292-3297. doi:10.1063/1.436135Kalneus, E. V., Stass, D. V., & Molin, Y. N. (2005). Typical applications of MARY spectroscopy: Radical ions of substituted benzenes. Applied Magnetic Resonance, 28(3-4), 213-229. doi:10.1007/bf03166757Kruppa, A. I., Leshina, T. V., Sagdeev, R. Z., Korolenko, E. C., & Shokhirev, N. V. (1987). Low-field CIDNP study of photoinduced electron transfer reactions. Chemical Physics, 114(1), 95-101. doi:10.1016/0301-0104(87)80022-

Search for light pseudoscalar sgoldstino in K- decays

A search for the light pseudoscalar sgoldstino production in the three body K- decay K-->pipi0P has been performed with the ISTRA+ detector exposed to the 25 GeV negative secondary beam of the U70 proton synchrotron. No signal is seen. An upper limit for the branching ratio Br(K->pipi0P), at 90% confidence level, is found to be around 9*10**-6 in the effective mass m(P) range from 0 till 200 MeV, excluding the region near m(pi0) where it degrades to 3.5*10**-5.Comment: 10 pages, LATEX, 8 EPS figures, revised version, to be published in Phys.Lett.

High statistic measurement of the K- -> pi0 e- nu decay form-factors

The decay K- -> pi0 e- nu is studied using in-flight decays detected with the ISTRA+ spectrometer. About 920K events are collected for the analysis. The lambda+ slope parameter of the decay form-factor f+(t) in the linear approximation (average slope) is measured: lambda+(lin)= 0.02774 +- 0.00047(stat) +- 0.00032(syst). The quadratic contribution to the form-factor was estimated to be lambda'+ = 0.00084 +- 0.00027(stat) +- 0.00031(syst). The linear slope, which has a meaning of df+(t)/dt|_{t=0} for this fit, is lambda+ = 0.02324 +- 0.00152(stat) +- 0.00032(syst). The limits on possible tensor and scalar couplings are derived: f_{T}/f_{+}(0)=-0.012 +- 0.021(stat) +- 0.011$(syst), f_{S}/f_{+}(0)=-0.0037^{+0.0066}_{-0.0056}(stat) +- 0.0041(syst).Comment: 11 pages, 8 figures. Accepted by Phys.Lett.

Quantum Mechanics and Black Holes in Four-Dimensional String Theory

In previous papers we have shown how strings in a two-dimensional target space reconcile quantum mechanics with general relativity, thanks to an infinite set of conserved quantum numbers, ``W-hair'', associated with topological soliton-like states. In this paper we extend these arguments to four dimensions, by considering explicitly the case of string black holes with radial symmetry. The key infinite-dimensional W-symmetry is associated with the $\frac{SU(1,1)}{U(1)}$ coset structure of the dilaton-graviton sector that is a model-independent feature of spherically symmetric four-dimensional strings. Arguments are also given that the enormous number of string {\it discrete (topological)} states account for the maintenance of quantum coherence during the (non-thermal) stringy evaporation process, as well as quenching the large Hawking-Bekenstein entropy associated with the black hole. Defining the latter as the measure of the loss of information for an observer at infinity, who - ignoring the higher string quantum numbers - keeps track only of the classical mass,angular momentum and charge of the black hole, one recovers the familiar a quadratic dependence on the black-hole mass by simple counting arguments on the asymptotic density of string states in a linear-dilaton background.Comment: 18 page