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We compute the three-loop QCD corrections to the massive quark-anti-quark-photon form factors $F_1$ and $F_2$ in the large-$N_c$ limit. The analytic results are expressed in terms of Goncharov polylogarithms. This allows for a straightforward numerical evaluation. We also derive series expansions, including power suppressed terms, for three kinematic regions corresponding to small and large invariant masses of the photon momentum, and small velocities of the heavy quarks., Comment: 20 pages

Nanoscale vanadium dioxide doped with chromium and iron is obtained via molecular layering method on the surface of a single-crystal silicon. The qualitative and quantitative composition of the samples is determined by photometry and magnetochemical analysis. The morphology is examined by AFM and SEM. Two independent methods (magnetic susceptibility and impedance spectroscopy) show the presence of the semiconductor-metal phase transition in the obtained structures in the range 100–125 K. The considerable influence of the alloying element content on the characteristics of the phase transition, including its temperature, is established.

A technique for determining Young's modulus of oriented nanowhiskers using atomic force microscopy is developed. Results of studying the effect of geometric parameters on Young's modulus of ori� ented gallium arsenide nanowhiskers are presented. Young's modulus value has been found experimentally for the GaAs nanowhiskers, which varied from 9 to 143 GPa depending on their aspect ratio. It is shown that Young's modulus of the GaAs nanowhiskers depends on their aspect ratio and can exceed Young's modulus of the bulk GaAs. The results can be used in the development of technological processes for forming struc� tures of the nanoand microsystem hardware and the nanoand microelectronics based on oriented nano� whiskers, in particular arsenide gallium nanowhiskers, as well as in the development of techniques for the nanodiagnostics of filamentary structures.

The paper presents the experimental results of the combination of AFM lithography and plasma chemical etching the surface of the gallium arsenide samples. Results dilution and application modes for AFM lithography photoresist, also shown on the image forming modes photoresist surface. Showing results nanoprofilirovaniya surface. Results regimes plasma chemical etching. The analysis of the etching rate is etched surface roughness was studied by atomic force microscopy. Judged from the vertical deflection angle of the initial structures and photoresist obtained after etching.

The results of investigation of a memristor nanostructures based on titanium nanowires fabricated by methods of focused ion beams are presented. The memristor effect in the titanium nanowires is investigated by an AFM in the mode of spreading resistance map. It is shown that the using of FIB milling allows to form conductive channels with different shapes and nanoscale dimensions. The analysis of the I-Vs of Ti nanowire memristor structures shows that the resistivity ratio in the high- and low-resistance states is higher than 10 2 . After a series of measurements determined that memristor structures have a high stability of resistance. The obtained results are most promising for developing the technological processes of the formation of resistive operation memory cells.

We present the analytic computation of all the planar master integrals which contribute to the two-loop scattering amplitudes for Higgs$\to 3$ partons, with full heavy-quark mass dependence. These are relevant for the NNLO corrections to fully inclusive Higgs production and to the NLO corrections to Higgs production in association with a jet, in the full theory. The computation is performed using the differential equations method. Whenever possible, a basis of master integrals that are pure functions of uniform weight is used. The result is expressed in terms of one-fold integrals of polylogarithms and elementary functions up to transcendental weight four. Two integral sectors are expressed in terms of elliptic functions. We show that by introducing a one-dimensional parametrization of the integrals the relevant second order differential equation can be readily solved, and the solution can be expressed to all orders of the dimensional regularization parameter in terms of iterated integrals over elliptic kernels. We express the result for the elliptic sectors in terms of two and three-fold iterated integrals, which we find suitable for numerical evaluations. This is the first time that four-point multiscale Feynman integrals have been computed in a fully analytic way in terms of elliptic functions., Comment: 46 pages, 5 figures, ancillary files provided

We use the method of differential equations to analytically evaluate all planar three-loop Feynman integrals relevant for form factor calculations involving massive particles. Our results for ninety master integrals at general $q^2$ are expressed in terms of multiple polylogarithms, and results for fiftyone master integrals at the threshold $q^2=4m^2$ are expressed in terms of multiple polylogarithms of argument one, with indices equal to zero or to a sixth root of unity.

A novel strategy for the synthesis of 4-amino-3-cyano-2,2′- and 5′-amino-4′-cyano-2,3′-bipyrroles via readily available 1-amino-3-imino-3H-pyrrolizine-2-carbonitriles has been developed. The rearrangement leading to 5′-amino-4′-cyano-2,3′-bipyrroles involves formation of the intermediate aziridine, which undergoes other side ring-opening.

Joint replacement is being actively developed within modern orthopedics. One novel material providing fast implantation is bioactive coatings. The synthesis of targeted nanocoatings on metallic nanotitanium surface is reported in this paper. TiO2-based micro- and nanocoatings were produced by sol-gel synthesis using dip-coating technology with subsequent fast (shock) drying in hot plate mode at 400 °C. As a result of shock drying, the two-level hierarchical TiO2 nanolayer on the nanotitanium was obtained. This two-level hierarchy includes nanorelief of porous xerogel and microrelief of the micron-sized “defect” network (a crack network). The thickness of TiO2 nanolayers was controlled by repeating dip-coating process the necessary number of times after the first layer deposition. The state of the MS3T3-E1 osteoblast cell line (young cells that form bone tissue) on the two-level hierarchical surface has been studied. Particularly, adhesion character, adhesion time and morphology have been studied. The reported results may serve the starting point for the development of novel bioactive coatings for bone and teeth implants.

Due to variety of applications of tin oxide thin films such as solid state gas sensors, solar cells, transparent conductive oxide coatings, catalysts, and anodes for Li-ion batteries, it is desirable to develop convenient and high effective technique of atomic layer deposition for this material. In this paper we consider in details the prospects of using tetraethyltin to produce thin films of tin dioxide by atomic layer deposition. Water, hydrogen peroxide, oxygen, ozone and oxygen plasma were used as co-reactants for SnOx deposition. It was found that the type of co-reactant has a huge impact on the growth rate, composition and morphology of the films. Features of synthesis and prospects for use the films in lithium-ion batteries are considered.

We evaluate a four-loop conformal integral, i.e. an integral over four four-dimensional coordinates, by turning to its dimensionally regularized version and applying differential equations for the set of the corresponding 213 master integrals. To solve these linear differential equations we follow the strategy suggested by Henn and switch to a uniformly transcendental basis of master integrals. We find a solution to these equations up to weight eight in terms of multiple polylogarithms. Further, we present an analytical result for the given four-loop conformal integral considered in four-dimensional space-time in terms of single-valued harmonic polylogarithms. As a by-product, we obtain analytical results for all the other 212 master integrals within dimensional regularization, i.e. considered in D dimensions., 10 pages, 2 figures

We present analytic results for the three-loop static potential of two heavy quarks. The analytic calculation of the missing ingredients is outlined and results for the singlet and octet potential are provided., 8 pages, 1 figure, v2: minor changes, references added, appendix with general octet potential added, corresponds to published version

In this contribution we discuss the four-loop relation between the on-shell and $\bar{\rm MS}$ definition of heavy quark masses which is applied to the top, bottom and charm case. We also present relations between the $\bar{\rm MS}$ quark mass and various threshold mass definitions and discuss the uncertainty at next-to-next-to-next-to-leading order.

Mesoporous silica nanoparticles (MSNs) impregnated with zero-valent Fe (Fe(0) @ MCM-41) represent an attractive nanocarrier system for drug delivery into tumor cells. The major goal of this work was to assess whether MSNs can penetrate the blood-brain barrier in a glioblastoma rat model. Synthesized MSNs nanomaterials were characterized by energy dispersive X-ray spectroscopy, measurements of X-ray diffraction, scanning electron microscopy and Mössbauer spectroscopy. For the detection of the MSNs by MR and for biodistribution studies MSNs were labeled with zero-valent Fe. Subsequent magnetometry and nonlinear-longitudinal-response-M2 (NLR-M2) measurements confirmed the MR negative contrast enhancement properties of the nanoparticles. After incubation of different tumor (C6 glioma, U87 glioma, K562 erythroleukemia, HeLa cervix carcinoma) and normal cells such as fibroblasts and peripheral blood mononuclear cells (PBMCs) MSNs rapidly get internalized into the cytosol. Intracellular residing MSNs result in an enhanced cytotoxicity as Fe(0) @ MCM-41 promote the reactive oxygen species production. MRI and histological studies indicated an accumulation of intravenously injected Fe(0) @ MCM-41 MSNs in orthotopic C6 glioma model. Biodistribution studies with measurements of second harmonic of magnetization demonstrated an increased and dose-dependent retention of MSNs in tumor tissues. Taken together, this study demonstrates that MSNs can enter the blood-brain barrier and accumulate in tumorous tissues.

The CN-functionalized pyrrole(indole)-3(2H)-furanone derivatives are readily synthesized via the domino reaction of diverse pyrrole(indole) carboxylic acids with tertiary cyanopropargylic alcohols (Et3N, MeCN, MW reactor, 100 °C, 1.2 atm) in up to 93% yield.

The aim of this study was to assess CD45-positive platelets (CD45+ platelets) involvement in restenosis development after drug-eluting stent (DES) implantation in patients with stable coronary artery disease (CAD). The study comprised 126 male and female patients with stable angina pectoris, who underwent elective coronary stenting with DES and follow-up angiography within 6–12 months. The patients were assigned to the group with restenosis (n = 53) or group without restenosis (n = 73) according to the follow-up angiograms. In both groups we compared the level in blood of CD45+ platelets, the clinical, laboratory and angiographic variables, which may affect the development of restenosis. We have also constructed a logit regression model for prognosis of restenosis occurrence after DES implantation. The blood count of CD45+ platelets was higher in patients with restenosis than in patients without: 0.82 % (0.58; 1.12) vs. 0.34 % (0.20; 0.68), p < 0.001, data are expressed as median (lower quartile; upper quartile). By binary comparisons of more than 35 different clinical, laboratory and angiographic variables we identified 8 significant risk factors for the development of stent restenosis after DES. In order to define the risk of the development of restenosis, we have built a logit regression model. The resulting logit regression equation included the level of CD45+ platelets, the neutrophil to lymphocyte ratio (NLR), small diameter arteries stenting and the number of simultaneously implanted stents in one patient. Receiver operating characteristic (ROC) curve analysis has demonstrated the high prognostic value of the resulting logit regression equation with an area under the curve (AUC) of 0.91 % (p < 0.001). The acquired data indicate the presence of a close relationship between circulating CD45+ platelets and restenosis development after DES implantation in patients with stable CAD.

Conditions were determined for the synthesis of TiO2 mesoporous thin films on silicon by the solgel method in the version of coating by dipping silicon plates in a TiO2 sol (dip-coating).

Results obtained in a study of the influence exerted by the technological modes of local anodic oxidation (LAO) on the process in which nanosized oxide structures (NOSs) are formed on the surface of gallium arsenide are reported. The effect of the amplitude and duration of voltage pulses applied to the probesubstrate system, relative air humidity in the technological chamber, and amplitude of cantilever oscillations on the geometric parameters of gallium arsenide NOSs has been examined. It was found that raising the relative humidity from 60 to 90% results in a decrease in the threshold LAO voltage from 7.0 to 6.0 V. It is shown that raising the oscillation amplitude from 0.1 to 2.8 nm leads to a decrease in the NOS height from 3.20 ± 0.34 to 1.10 ± 0.13 nm and in the NOS diameter from 218.4 ± 29.5 to 78.1 ± 10.3 nm.

Samples of pure and chromium- or iron-doped nanosized vanadium dioxide of different morphologies were fabricated by the method of atomic layer deposition (ALD) on the surface of substrates of different structures: amorphous silica and single-crystal silicon. The samples were characterized using photometry and magnetochemical analysis. The occurrence of the semiconductor-metal phase transition (SMPT) was demonstrated on the basis of temperature dependencies, and it was shown that the transition characteristics depended on the substrate type and the nature and amount of the doping element. The SMPT temperature decreases from 340 K (the value characterizing the bulk material) to 100–180 K, depending on the sample composition and structure.

Phosphine reacts with 1-methoxy-4-vinylbenzene in the superbase suspension KOH-dimethylsulfoxide (70–100 °C, atmospheric pressure) to form regiospecifically anti-Markovnikov adducts, bis[2-(4-methoxyphenyl)ethyl]phosphine (1) and tris[2-(4-methoxyphenyl)ethyl]phosphine (2), representatives of rare arylalkylphosphines. The conditions for the selective preparation of phosphines 1 or 2 in 67% and 80% yields, respectively, have been elaborated. The phosphines have been oxidized with aqueous solution of H2O2, elemental sulfur, or selenium to afford the corresponding phosphine chalcogenides in good yields (95–99%).

A three-component, atom-economic reaction between natural quinine, lupinine, or anabasine, secondary phosphines, and elemental sulfur occurs under mild conditions to yield previously unknown optically active dithiophosphinates.

TBSOTf-promoted C–C coupling of alkyl and trialkylsilyl nitronates with silyl ketene acetals yields functionalized nitroso acetals. This conversion may serve as a new simple procedure to reverse the conventional reactivity of aliphatic nitro compounds. Preliminary results on the hydrogenation of nitroso acetals into amino acids derivatives, as well as TFA-catalyzed transformations of nitroso acetals, are examined to prove the possible utility of this umpolung procedure.

The possibility of the directed regulation of geometric parameters of the porous structure of mesoporous oxide inorganic materials based on the controlled variation of the pore diameter has been studied. The pore sizes have been varied on the basis of synthesizing aluminum-oxygen nanolayers of the given thickness on the surface of silica SBA-15 pores using the molecular layering method. This made it possible to increase the thickness of the wall separating them without changing the distance between the pore centers. A formula for determining the pore radius of the obtained material has been proposed on the basis of data on the interplanar spacing and pore radius of the initial silica and the specific porosity of the modified silica.

Micro- and nanopowders of aluminum oxide with nanoparticles ranging from 200 μm to 40 nm obtained by the sol-gel technique have been investigated and the influence of their dimensions on phase transitions γ-Al2O3 → α-Al2O3 have been studied using differential thermal analysis, X-ray diffraction, and scanning electron microscopy. The data of X-ray-phase analysis show that the phase transition from γ-Al2O3 to θ-Al2O3 is typical for aluminum oxide nanoparticles at 900°C, while phase transitions from γ-Al2O3 to θ-Al2O3 are practically not observed at 900°C for microsized aluminum oxide. The transition to the form α-Al2O3 proceeds in the temperature range from 1150 to 1200°C. Generally, the results indicate that a reduction in particle sizes allows us to stabilize the formation of α-Al2O3 at lower temperatures.

We evaluate a Laurent expansion in dimensional regularization parameter ϵ = ( 4 − d ) / 2 of all the master integrals for four-loop massless propagators up to weight twelve, using a recently developed method of one of the present coauthors (R.L.) and extending thereby results by Baikov and Chetyrkin obtained at weight seven. We observe only multiple zeta values in our results. Therefore, we conclude that all the four-loop massless propagator integrals, with any integer powers of numerators and propagators, have only multiple zeta values in their epsilon expansions up to weight twelve.

A technique for determining Young's modulus of vertically aligned carbon nanotubes using the refined micromechanical model of the nanoindentation of a forest of vertically aligned carbon nanotubes is developed. The results of experimental studies of Young's modulus determination for vertically aligned car� bon nanotubes with different geometrical parameters are given. It is shown that, for a forest of carbon nano� tubes with an effective diameter of around 100 nm and an effective length of approximately 2 μm, as well as for a forest with an effective diameter of carbon nanotubes of roughly 52 nm and their effective length of nearly 500 nm, the values of Young's modulus are 1.68 ± 0.08 and 1.01 ± 0.05 TPa, respectively. Our results can be used for developing the technological processes of the formation of structures for nanoand micro� electronics and nanoand microsystem technology on the basis of vertically aligned carbon nanotubes.

The paper presents the results of experimental investigations into probe modification for atomic-force microscopy (AFM) and scanning tunneling microscopy (STM) by etching the point of AFM cantilevers and tungsten STM probes by applying the method of focused ion beams (FIBs). It is shown that the use of etching by the IB method allows one to obtain the probes with rounding that is less than 10 nm and with an aspect ratio of 1: 50. The application of these probes increases the resolution and the reliability of measuring by the AFM and STM methods. The obtained results can be used for developing the technological processes of production and modification of sensor probes for AFM and STM, as well as the methods for diagnostics of the structures of microelectronics, nanoelectronics and the microsystem and nanosystem technologies.

Conditions for the preparation of Fe3O4@SiO2 core-shell nanoparticles aggregatively stable in aqueous solutions were determined.

The sequence of isomeric transformations of intermediate adducts formed upon nuceleophilic addition of β-phenyl-α-alanine to 4-hydroxy-4-methylpent-2-ynenitrile affording a neutral or two alternative zwitterionic forms (with protonated imino or amino groups) of the product was studied quantum chemically by the B3LYP/6-31G(d,p) method and by UV spectroscopy. In the isolated state, the equilibrium is completely shifted toward the neutral form. Taking into account the polyhydrate environment increases the portion of the zwitterionic form bearing a protonated imino group of the dihydrofuran cycle. Protonation of the amino group of amino acid is thermodynamically unfavorable.

The problem of stability of colloids recently begins to attract extra attention in construction materials science. This is due to numerous attempts to employ different kind of nanoscale modifiers for production of building materials with enhanced operational properties. Problems of stability and coagulation in colloidal dispersions are studied for several decades, and numerous results were already obtained within framework of Smoluchowski coagulation theory. In the present work we have performed numerical study of the flocculation process and compared the results with well-known ones. It was shown that even for complex pairwise potential the kinetics of number density for isolated particles is not very different from the kinetics which corresponds to constant coagulation kernel. However, for number density of many-particle aggregates we have observed number of peculiarities, including semi-periodic behavior.

Compounds bearing chlorodifluoromethyl group can be assembled from organozinc chlorides, (chlorodifluoromethyl)trimethylsilane (Me3SiCF2Cl), and sulfuryl chloride as a chlorine source. Reactions of 1,1-difluoro-substituted organozinc bromides (RCF2ZnBr) with different chlorinating reagents lead to predominant or partial formation of the products bearing bromodifluoromethyl group.

The three-component reaction between isoquinoline, 1,3-diphenylprop-2-yn-1-one and nitromethane (90–100°C, 26h) affords 2,4-diphenyl- pyrido[2,1-a]isoquinolinium nitrite in 23% yield along with oligomers.

Within DFT(B3LYP) methods, the potential interaction surface of a monomethyl mercury cation with G, H, S, and Y amino acids entering into the composition of the active cavity of acetylcholinesterase is studied. The preference for different centeres of amino acids for the interaction with the metal atom is investigated. The principal possibility of Cα-deprotonation of amino acid as a result of the interaction with the electronegative carbon center of methylmercury is analyzed. The effect of deprotonation is shown to cause demethylation of methylmercury. Iterative action is assumed to occur in Hg(II) and MeHg+ biochemical objects, which explains the high toxicity of microconcentrations of these compounds.

Experimental results on the conditions of activation of probe nanolithography of a thin titanium film by means of local anodic oxidation are reported. It is established that ultraviolet stimulation reduces the geometric dimensions of nanometric oxide structures. The stimulation is accompanied by an increase in the amplitude and duration of the threshold voltage pulse, correspondingly, from 6 to 7 V and from 50 to 100 ms at the relative humidity 50%. The experimental data on the effect of the cantilever coating material and substrate temperature on the geometric dimensions of nanometric oxide structures are reported.

This work presents the results of the formation and investigation of Al2O3/ZnO:In/ZnO/Ti memristor structures. It is shown that using Ti layer can improve memristive effect. Resistive switching from high resistance state (HRS) to low resistance state (LRS) occurred at 2.1 ± 0.3 V, and from LRS to HRS at -1.5 ± 0.3 V. Endurance test showed that HRS was 5.51 ± 0.13 GΩ and LRS was 0.25 ± 0.05 GΩ. HRS/LRS coefficient equalled to 22. The results can be useful for micro- and nanoelectronics elements manufacturing, as well as micro- and nanosystem engineering using probe nanotechnologies and for ZnO- based RRAM fabrication.

A model for the oxide nanostructures formation by the local anodic oxidation method is presented. Dependences of height, depth, and diameter of titanium oxide nanostructures on the applied voltage pulse duration are obtained, as well as the oxide nanostructures profile for given technological parameters.

A layout of resistive random access memory was developed and manufactured based on TiO2 nanostructures obtained by the local anodic oxidation. It is shown that TiO2 nanostructures exhibit a stable memristor effect without carrying out an additional electroforming operation at 20 measurement cycles. The resistance ratio of the memristor nanostructure in the high-resistance state and low-resistance state was 16.

One-dimensional nanostructures based on single-layer carbon nanotubes (CNTs) with FeBr2 chains and two-dimensional nanostructures with Fe-O-Fe layers deposited on the surface of silica gel by molecular layering have been synthesized. An Mossbauer spectroscopy examination has shown that a magnetic structure with T C = 21 K and B in = 29.8 ± 0.5 T is formed in nanotubes with FeBr2 · 2H2O at T = 15 K. In the case of the Fe-O-Fe layers, the surface of silica gel has a nonmagnetic monolayer along with α-Fe2O3 nanoclusters with B in(1) = 48.5 ± 0.5 T and B in(2) = 46.4 ± 0.5 T at T = 15 K and the temperature T C = 210 K. The variation in magnetization with temperature is calculated using three models of phase transitions, namely, the model of critical indices, the two-dimensional Ising model (the Onsager formula), and the three-dimensional Heisenberg model. The experimental data are fitted best by the model of critical indices with the critical parameters α = 0.22 and 0.18 for 1D and 2D structures, respectively, demonstrating that these nanosystems approach two-dimensional structures (α = 0.15).

The electronic absorption spectra of radical cations of dipyrroles with a phenylene bridge were studied by laser flash photolysis and quantum chemical methods. Intense absorption bands of the radical cations in the visible region (λmax ≈ 500 nm, emax > 2 · 104 L mol−1 cm−1) are caused by excitation of electrons from single occupied MOs to the LUMO. In the near IR region, calculations predict additional, relatively intense (f≈ 0.27–0.29) electronic transitions associated with excitation of electrons from low-lying MOs to the single occupied MO.

All three-loop on-shell QCD Feynman integrals with two masses can be reduced to 27 master integrals. Here we calculate these master integrals, expanded in epsilon, both exactly in the mass ratio and as series in limiting cases., 22 pages; complete results as Mathematica files are available at http://www-ttp.particle.uni-karlsruhe.de/Progdata/ttp09/ttp09-08/ v2: 2 references added, v3: Ref. [16] corrected

Five-membered cyclic nitronates 3 undergo TBSOTf-catalysed C–C coupling reactions with silyl ketene acetal 4 to give good to excellent yields of 3,3-disubstituted N-(OTBS)-isoxazolidines 5, which could not be obtained by previously known procedures. The problems of diastereoselectivity of the C–C coupling reactions are discussed. The transformations of the nitroso acetals 5 upon action of AcFOH/methanol or some reducing agents (H2/NiRa, LAH, Al/Hg) have been examined.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

The deprotonation reaction of radical cations of 1-(2-pyrrolyl)-4-(1-vinyl-2-pyrrolyl)benzene has been studied by nanosecond laser photolysis. Bimolecular rate constants have been determined for the transfer of proton to the heterocyclic base. Analysis of the yields has been carried out of the final products of the radical-cation reaction of 1-(2-pyrrolyl)-4-(1-vinyl-2-pyrrolyl)benzene in the presence and absence of bases. Comparison of the results of impulse and stationary photolysis showed that inhibition of the radical cation reaction occurs at the stage of forming the radical cations.