Dubna State University

The study of nanostructured drug delivery systems allows the development of novel platforms for the efficient transport and controlled release of drug molecules in the harsh microenvironment of diseased tissues of living systems, thus offering a wide range of functional nanoplatforms for smart application in biotechnology and nanomedicine. This article highlights recent advances of smart nanocarriers composed of organic (including polymeric micelles and vesicles, liposomes, dendrimers, and hydrogels) and inorganic (including quantum dots, gold and mesoporous silica nanoparticles) materials. Despite the remarkable developments of recent synthetic methodologies, most of all nanocarriers’ action is associated with a number of unwanted side effects that diminish their efficient use in biotechnology and nanomedicine applications. This highlights some critical issues in the design and engineering of nanocarrier systems for biotechnology applications, arising from the complex environment and multiform interactions established within the specific biological media.

Liposomes are nano-sized spherical vesicles composed of an aqueous core surrounded by one (or more) phospholipid bilayer shells. Owing to their high biocompatibility, chemical composition variability, and ease of preparation, as well as their large variety of structural properties, liposomes have been employed in a large variety of nanomedicine and biomedical applications, including nanocarriers for drug delivery, in nutraceutical fields, for immunoassays, clinical diagnostics, tissue engineering, and theranostics formulations. Particularly important is the role of liposomes in drug-delivery applications, as they improve the performance of the encapsulated drugs, reducing side effects and toxicity by enhancing its in vitro- and in vivo-controlled delivery and activity. These applications stimulated a great effort for the scale-up of the formation processes in view of suitable industrial development. Despite the improvements of conventional approaches and the development of novel routes of liposome preparation, their intrinsic sensitivity to mechanical and chemical actions is responsible for some critical issues connected with a limited colloidal stability and reduced entrapment efficiency of cargo molecules. This article analyzes the main features of the formation and fabrication techniques of liposome nanocarriers, with a special focus on the structure, parameters, and the critical factors that influence the development of a suitable and stable formulation. Recent developments and new methods for liposome preparation are also discussed, with the objective of updating the reader and providing future directions for research and development.

First measurements of the Collins and Sivers asymmetries of charged hadrons produced in deep-inelastic scattering of muons on a transversely polarized 6LiD target are presented. The data were taken in 2002 with the COMPASS spectrometer using the muon beam of the CERN SPS at 160 GeV/c. The Collins asymmetry turns out to be compatible with zero, as does the measured Sivers asymmetry within the present statistical errors.

We present the final results of the spin asymmetries ${A}_{1}$ and the spin structure functions ${g}_{1}$ of the proton and the deuteron in the kinematic range $0.0008<x<0.7$ and $0.2<{Q}^{2}<100{\mathrm{GeV}}^{2}.$ For the determination of ${A}_{1},$ in addition to the usual method which employs inclusive scattering events and includes a large radiative background at low x, we use a new method which minimizes the radiative background by selecting events with at least one hadron as well as a muon in the final state. We find that this hadron method gives smaller errors for $x<0.02,$ so it is combined with the usual method to provide the optimal set of results.

We have measured the spin-dependent structure function ${g}_{1}^{p}$ in inclusive deep-inelastic scattering of polarized muons off polarized protons, in the kinematic range $0.003<x<0.7$ and $1{\mathrm{GeV}}^{2}<{Q}^{2}<60{\mathrm{GeV}}^{2}.$ A next-to-leading order QCD analysis is used to evolve the measured ${g}_{1}^{p}{(x,Q}^{2})$ to a fixed ${Q}_{0}^{2}.$ The first moment of ${g}_{1}^{p}$ at ${Q}_{0}^{2}=10{\mathrm{GeV}}^{2}$ is ${\ensuremath{\Gamma}}_{1}^{p}=0.136\ifmmode\pm\else\textpm\fi{}0.013$ (stat) $\ifmmode\pm\else\textpm\fi{}0.009$ (syst) $\ifmmode\pm\else\textpm\fi{}0.005$ (evol). This result is below the prediction of the Ellis-Jaffe sum rule by more than two standard deviations. The singlet axial charge ${a}_{0}$ is found to be $0.28\ifmmode\pm\else\textpm\fi{}0.16.$ In the Adler-Bardeen factorization scheme, $\ensuremath{\Delta}g\ensuremath{\simeq}2$ is required to bring \ensuremath{\Delta}\ensuremath{\Sigma} in agreement with the quark-parton model. A combined analysis of all available proton, deuteron, and ${}^{3}\mathrm{He}$ data confirms the Bjorken sum rule.

To study fundamental questions of hadron and nuclear physics in interactions of antiprotons with nucleons and nuclei, the universal PANDA detector will be built. Gluonic excitations, the physics of strange and charm quarks and nucleon structure studies will be performed with unprecedented accuracy thereby allowing high-precision tests of the strong interaction. The proposed PANDA detector is a state-of-the art internal target detector at the HESR at FAIR allowing the detection and identification of neutral and charged particles generated within the relevant angular and energy range. This report presents a summary of the physics accessible at PANDA and what performance can be expected.

We investigate the infrared behavior of gluon and ghost propagators in Landau-gauge QCD by means of an exact renormalization group equation. We explain how, in general, the infrared momentum structure of Green functions can be extracted within this approach. An optimization procedure is devised to remove residual regulator dependences. In Landau-gauge QCD this framework is used to determine the infrared leading terms of the propagators. The results support the Kugo-Ojima confinement scenario. Possible extensions are discussed.

The unitary isobar model MAID2007 has been developed to analyze the world data of pion photo- and electroproduction. The model contains both a common background and several resonance terms. The background is unitarized according to the K-matrix prescription, and the 13 four-star resonances with masses below 2 GeV are described by appropriately unitarized Breit-Wigner forms. The data have been analyzed by both single-energy and global fits, and the transverse and longitudinal helicity amplitudes have been extracted for the four-star resonances below 2 GeV. Because of its inherent simplicity, MAID2007 is well adopted for predictions and analysis of the observables in pion photo- and electroproduction.

The lowest stationary quantum state of neutrons in the Earth's gravitational field is identified in the measurement of neutron transmission between a horizontal mirror on the bottom and an absorber/scatterer on top. Such an assembly is not transparent for neutrons if the absorber height is smaller than the ``height'' of the lowest quantum state.

A new upper limit for the probability of spontaneous muonium to antimuonium conversion was established at ${P}_{\mathrm{M}\overline{\mathrm{M}}}\ensuremath{\le}8.3\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}11}$ ( $90%$ C.L.) in 0.1 T magnetic field, which implies consequences for speculative extensions to the standard model. Coupling parameters in $R$-parity-violating supersymmetry and the mass of a flavor diagonal bileptonic gauge boson can be significantly restricted. A ${Z}_{8}$ model with radiative mass generation through heavy lepton seed and the minimal version of 331 models are disfavored.

The role of intrinsic $\mathbit{k}{\text{ }}_{\ensuremath{\perp}}$ in inclusive and semi-inclusive Deep Inelastic Scattering processes ($\ensuremath{\ell}p\ensuremath{\rightarrow}\ensuremath{\ell}hX$) is studied with exact kinematics within QCD parton model at leading order; the dependence of the unpolarized cross section on the azimuthal angle between the leptonic and the hadron production planes (Cahn effect) is compared with data and used to estimate the average values of ${k}_{\ensuremath{\perp}}$ both in quark distribution and fragmentation functions. The resulting picture is applied to the description of the weighted single spin asymmetry ${A}_{UT}^{\mathrm{sin}({\ensuremath{\phi}}_{\ensuremath{\pi}}\ensuremath{-}{\ensuremath{\phi}}_{S})}$ recently measured by the HERMES collaboration at DESY; this allows to extract some simple models for the quark Sivers functions. These are compared with the Sivers functions which succeed in describing the data on transverse single spin asymmetries in ${p}^{\ensuremath{\uparrow}}p\ensuremath{\rightarrow}\ensuremath{\pi}X$ processes; the two sets of functions are not inconsistent. The extracted Sivers functions give predictions for the COMPASS measurement of ${A}_{UT}^{\mathrm{sin}({\ensuremath{\phi}}_{\ensuremath{\pi}}\ensuremath{-}{\ensuremath{\phi}}_{S})}$ in agreement with recent preliminary data, while their contribution to HERMES ${A}_{UL}^{\mathrm{sin}{\ensuremath{\phi}}_{\ensuremath{\pi}}}$ is computed and found to be small. Predictions for ${A}_{UT}^{\mathrm{sin}({\ensuremath{\phi}}_{K}\ensuremath{-}{\ensuremath{\phi}}_{S})}$ for kaon production at HERMES are also given.

We present a complete theoretical study of the relationship between the structure (tip shape and dimensions) and function (selectivity and rectification) of asymmetric nanopores on the basis of previous experimental studies. The theoretical model uses a continuum approach based on the Nernst-Planck equations. According to our results, the nanopore transport properties, such as current-voltage (I-V) characteristics, conductance, rectification ratio, and selectivity, are dictated mainly by the shape of the pore tip (we have distinguished bullet-like, conical, trumpet-like, and hybrid shapes) and the concentration of pore surface charges. As a consequence, the nanopore performance in practical applications will depend not only on the base and tip openings but also on the pore shape. In particular, we show that the pore opening dimensions estimated from the pore conductance can be very different, depending on the pore shape assumed. The results obtained can also be of practical relevance for the design of nanopores, nanopipettes, and nanoelectrodes, where the electrical interactions between the charges attached to the nanostructure and the mobile charges confined in the reduced volume of the inside solution dictate the device performance in practical applications. Because single tracks are the elementary building blocks for nanoporous membranes, the understanding and control of their individual properties should also be crucial in protein separation, water desalination, and bio-molecule detection using arrays of identical nanopores.

We have studied the muon neutrino and antineutrino quasi-elastic (QEL) scattering reactions (ν μ n→μ − p and $\bar{\nu }_{\mu}p\to\mu^{+}n$ ) using a set of experimental data collected by the NOMAD Collaboration. We have performed measurements of the cross-section of these processes on a nuclear target (mainly carbon) normalizing it to the total ν μ ( $\bar{\nu}_{\mu}$ ) charged-current cross section. The results for the flux-averaged QEL cross sections in the (anti)neutrino energy interval 3–100 GeV are $\langle \sigma_{\mathrm{qel}}\rangle_{\nu_{\mu}}=(0.92\pm0.02(\mathrm{stat})\pm0.06(\mathrm{syst}))\times10^{-38}~\mathrm{cm}^{2}$ and $\langle\sigma_{\mathrm{qel}}\rangle_{\bar{\nu}_{\mu}}=(0.81\pm0.05(\mathrm{stat})\pm0.09(\mathrm{syst}))\times10^{-38}~\mathrm{cm}^{2}$ for neutrino and antineutrino, respectively. The axial mass parameter M A was extracted from the measured quasi-elastic neutrino cross section. The corresponding result is M A =1.05±0.02(stat)±0.06(syst) GeV. It is consistent with the axial mass values recalculated from the antineutrino cross section and extracted from the pure Q 2 shape analysis of the high purity sample of ν μ quasi-elastic 2-track events, but has smaller systematic error and should be quoted as the main result of this work. Our measured M A is found to be in good agreement with the world average value obtained in previous deuterium filled bubble chamber experiments. The NOMAD measurement of M A is lower than those recently published by K2K and MiniBooNE Collaborations. However, within the large errors quoted by these experiments on M A , these results are compatible with the more precise NOMAD value.

The NEMO 3 detector, which has been operating in the Fr\'ejus underground laboratory since February 2003, is devoted to the search for neutrinoless double-beta decay ($\ensuremath{\beta}\ensuremath{\beta}0\ensuremath{\nu}$). The half-lives of the two neutrino double-beta decay ($\ensuremath{\beta}\ensuremath{\beta}2\ensuremath{\nu}$) have been measured for $^{100}\mathrm{Mo}$ and $^{82}\mathrm{Se}$. After 389 effective days of data collection from February 2003 until September 2004 (phase I), no evidence for neutrinoless double-beta decay was found from $\ensuremath{\sim}7\text{ }\text{ }\mathrm{kg}$ of $^{100}\mathrm{Mo}$ and $\ensuremath{\sim}1\text{ }\text{ }\mathrm{kg}$ of $^{82}\mathrm{Se}$. The corresponding limits are ${T}_{1/2}(\ensuremath{\beta}\ensuremath{\beta}0\ensuremath{\nu})>4.6\ifmmode\times\else\texttimes\fi{}{10}^{23}\text{ }\mathrm{yr}$ for $^{100}\mathrm{Mo}$ and ${T}_{1/2}(\ensuremath{\beta}\ensuremath{\beta}0\ensuremath{\nu})>1.0\ifmmode\times\else\texttimes\fi{}{10}^{23}\text{ }\mathrm{yr}$ for $^{82}\mathrm{Se}$ (90% C.L.). Depending on the nuclear matrix element calculation, the limits for the effective Majorana neutrino mass are $⟨{m}_{\ensuremath{\nu}}⟩<0.7--2.8\text{ }\text{ }\mathrm{eV}$ for $^{100}\mathrm{Mo}$ and $⟨{m}_{\ensuremath{\nu}}⟩<1.7--4.9\text{ }\text{ }\mathrm{eV}$ for $^{82}\mathrm{Se}$.

High-precision measurements by the ATLAS Collaboration are presented of inclusive W + + , W - - and Z / * ( = e, ) Drell-Yan production cross sections at the LHC. The data were collected in proton-proton collisions at s = 7 TeV with an integrated luminosity of 4.6 fb -1 . Differential W + and W - cross sections are measured in a lepton pseudorapidity range | | < 2.5. Differential Z / * cross sections are measured as a function of the absolute dilepton rapidity, for |y | < 3.6, for three intervals of dilepton mass, m , extending from 46 to 150 GeV. The integrated and differential electron-and muon-channel cross sections are combined and compared to theoretical predictions using recent sets of parton distribution functions. The data, together with the final inclusive e p scattering cross-section data from H1 and ZEUS, are interpreted in a next-to-next-to-leading-order QCD analysis, and a new set of parton distribution functions, ATLAS-epWZ16, is obtained. The ratio of strange-to-light sea-quark densities in the proton is determined more accurately than in previous determinations based on collider data only, and is established to be close to unity in the sensitivity range of the data. A new measurement of the CKM matrix element |V cs | is also provided.

We present the results of a search for νμ→νe oscillations in the NOMAD experiment at CERN. The experiment looked for the appearance of νe in a predominantly νμ wide-band neutrino beam at the CERN SPS. No evidence for oscillations was found. The 90% confidence limits obtained are Δm2<0.4 eV2 for maximal mixing and sin2(2θ)<1.4×10−3 for large Δm2. This result excludes the LSND allowed region of oscillation parameters with Δm2≳10 eV2.

DANSS is a highly segmented 1 m3 plastic scintillator detector. Its 2500 one meter long scintillator strips have a Gd-loaded reflective cover. The DANSS detector is placed under an industrial 3.1 GWth reactor of the Kalinin Nuclear Power Plant 350 km NW from Moscow. The distance to the core is varied on-line from 10.7 m to 12.7 m. The reactor building provides about 50 m water-equivalent shielding against the cosmic background. DANSS detects almost 5000 ν˜e per day at the closest position with the cosmic background less than 3%. The inverse beta decay process is used to detect ν˜e. Sterile neutrinos are searched for assuming the 4ν model (3 active and 1 sterile ν). The exclusion area in the Δm142,sin2⁡2θ14 plane is obtained using a ratio of positron energy spectra collected at different distances. Therefore results do not depend on the shape and normalization of the reactor ν˜e spectrum, as well as on the detector efficiency. Results are based on 966 thousand antineutrino events collected at three different distances from the reactor core. The excluded area covers a wide range of the sterile neutrino parameters up to sin2⁡2θ14<0.01 in the most sensitive region.

This book presents a systematic and detailed account of the classical and quantum theory of the relativistic string and some of its modifications. Main attention is paid to the first-quantized string theory with possible applications to the string models of hadrons as well as to the superstring approach to unifications of all the fundamental interactions in the elementary particle physics and to the "cosmic" strings. Some new aspects are provided such as the consideration of the string in an external electromagnetic field and in the space-time of constant curvature (the de Sitter universe), th

The NOMAD experiment is a short base-line search for νμ − ντ oscillations in the CERN neutrino beam. The ντ's are searched for through their charged current interactions followed by the observation of the resulting τ− through its electronic, muonic or hadronic decays. These decays are recognized using kinematical criteria necessitating the use of a light target which enables the reconstruction of individual particles produced in the neutrino interactions. This paper describes the various components of the NOMAD detector: the target and muon drift chambers, the electromagnetic and hadronic calorimeters, the preshower and transition radiation detectors and the veto and trigger scintillation counters. The beam and data acquisition system are also described. The quality of the reconstruction and individual particles is demonstrated through the ability of NOMAD to observe Ks0's, Λ0's and π0's. Finally, the observation of τ− through its electronic decay being one of the most promising channels in the search, the identification of electrons in NOMAD is discussed.

Single- and multiple-nanopore membranes are both highly interesting for biosensing and separation processes, as well as their ability to mimic biological membranes. The density of pores, their shape, and their surface chemistry are the key factors that determine membrane transport and separation capabilities. Here, we report silicon nitride (SiN) membranes with fully controlled porosity, pore geometry, and pore surface chemistry. An ultrathin freestanding SiN platform is described with conical or double-conical nanopores of diameters as small as several nanometers, prepared by the track-etching technique. This technique allows the membrane porosity to be tuned from one to billions of pores per square centimeter. We demonstrate the separation capabilities of these membranes by discrimination of dye and protein molecules based on their charge and size. This separation process is based on an electrostatic mechanism and operates in physiological electrolyte conditions. As we have also shown, the separation capabilities can be tuned by chemically modifying the pore walls. Compared with typical membranes with cylindrical pores, the conical and double-conical pores reported here allow for higher fluxes, a critical advantage in separation applications. In addition, the conical pore shape results in a shorter effective length, which gives advantages for single biomolecule detection applications such as nanopore-based DNA analysis.