Influence of hydrothermal synthesis parameters on the properties of hydroxyapatite nanoparticles

• Sylwia Kuśnieruk,
• Jacek Wojnarowicz,
• Agnieszka Chodara,
• Tadeusz Chudoba,
• Stanislaw Gierlotka and
• Witold Lojkowski

Beilstein J. Nanotechnol. 2016, 7, 1586–1601, doi:10.3762/bjnano.7.153

• was synthesis-time dependent. The purpose of this study was to further develop the previously reported synthesis methods in order to: further extend the range of particle sizes, scale up the synthesis process by six orders of magnitude of six types of nano-hydroxyapatite, and to demonstrate that a

Dynamic of cold-atom tips in anharmonic potentials

• Tobias Menold,
• Peter Federsel,
• Carola Rogulj,
• Hendrik Hölscher,
• József Fortágh and
• Andreas Günther

Beilstein J. Nanotechnol. 2016, 7, 1543–1555, doi:10.3762/bjnano.7.148

• position fixed in space and monitor the time-dependent ionization rate Γ(t) at the ion detector. Measuring Γ(t) will then unveil dynamics within the distribution function. Detecting harmonic tip oscillations For harmonic potentials the time-dependent density distribution of an oscillating tip is given via

• Equation 6, resulting in a time-dependent detector signal As a periodic function, it can be expanded to harmonic oscillations at multiples of the fundamental frequency ω0. Here we used the Jakobi–Anger expansion with Iα being the modified Bessel functions of first kind. In the limit of small oscillation

Deformation-driven catalysis of nanocrystallization in amorphous Al alloys

• Rainer J. Hebert,
• John H. Perepezko,
• Harald Rösner and
• Gerhard Wilde

Beilstein J. Nanotechnol. 2016, 7, 1428–1433, doi:10.3762/bjnano.7.134

• must have occurred throughout the metallic glass during cold rolling and not only within shear bands [50]. Recent measurements of time-dependent tracer diffusion along shear bands that showed a non-monotonic behavior with an initial increase of the diffusivity upon relaxation moreover suggest that

On the pathway of cellular uptake: new insight into the interaction between the cell membrane and very small nanoparticles

• Claudia Messerschmidt,
• Daniel Hofmann,
• Anja Kroeger,
• Katharina Landfester,
• Volker Mailänder and
• Ingo Lieberwirth

Beilstein J. Nanotechnol. 2016, 7, 1296–1311, doi:10.3762/bjnano.7.121

• serum-containing media [8][11][13][14]. Interestingly, studies using cell models like artificial liposomes or polymersomes report the uptake of SiNPs into these structures in a size-dependent manner [15]. Different groups report that silica NPs are cytotoxic in a dose, size and time-dependent manner

The self-similarity theory of high pressure torsion

• Yan Beygelzimer,
• Roman Kulagin,
• Laszlo S. Toth and
• Yulia Ivanisenko

Beilstein J. Nanotechnol. 2016, 7, 1267–1277, doi:10.3762/bjnano.7.117

• β does not explicitly appear in Equations 3–7 but the problem is time-dependent because the flow stress σs depends on the von Mises strain eM, which in turn increases with β according to Equation 8. The global solution of Equations 4–9 has the following form: where x is the position vector. 2 A self

• solution at time t0 by a simple similarity transformation: where T(t) is time-dependent. Thus, the spatial distribution of y varies with time while remaining always geometrically similar to itself. This definition generalizes the concept of similarity in geometry where two figures are called similar if one

NO gas sensing at room temperature using single titanium oxide nanodot sensors created by atomic force microscopy nanolithography

• Li-Yang Hong and
• Heh-Nan Lin

Beilstein J. Nanotechnol. 2016, 7, 1044–1051, doi:10.3762/bjnano.7.97

• sensing. After a sufficient sensing time (which is shown in blue in the current-response figures), the chamber was evacuated again for NO desorption (which is shown in white in the current-response figures). After the pumping, the sensing cycle ended and the next cycle was started. The time-dependent

Thermo-voltage measurements of atomic contacts at low temperature

• Ayelet Ofarim,
• Bastian Kopp,
• Thomas Möller,
• León Martin,
• Johannes Boneberg,
• Paul Leiderer and
• Elke Scheer

Beilstein J. Nanotechnol. 2016, 7, 767–775, doi:10.3762/bjnano.7.68

• . To determine the resistance change caused by this temperature difference we also simulate the time-dependent sensor leads resistance due to laser heating. The simulation was fed with measured resistance values of a sample which had the same dimensions and fabrication parameters as the one used in the

• behavior along the red trace (red curve) and the green trace (green curve). b) The temperature behavior along y = 0 µm where the junction is located at position (0,0). The simulation shows a temperature difference of about 7 K. Time-dependent simulation of the resistivity of the two sensor leads due to

Finite-size effect on the dynamic and sensing performances of graphene resonators: the role of edge stress

• Chang-Wan Kim,
• Mai Duc Dai and
• Kilho Eom

Beilstein J. Nanotechnol. 2016, 7, 685–696, doi:10.3762/bjnano.7.61

• resonator, we need to numerically solve the equation of motion given by Equation 18, which is not straightforward. To numerically treat the equation of motion, we employed Galerkin’s method [37][38], where the transverse deflection of graphene is assumed to be in the form of with z(t) and being the time

• -dependent amplitude of transverse deflection and the deflection eigenmode, respectively. Consequently, the equation of motion can be written as shown in Equation 19. By multiplying the deflection eigenmode into Equation 19 followed by the integration by parts, the equation of motion becomes the Duffing

Tight junction between endothelial cells: the interaction between nanoparticles and blood vessels

• Yue Zhang and
• Wan-Xi Yang

Beilstein J. Nanotechnol. 2016, 7, 675–684, doi:10.3762/bjnano.7.60

• bile duct ligation researchers suggested a relationship between the time-dependent down-regulation of the occludin expression and a time-dependent increase of superoxide radical levels in the brain [68]. Another factor, shear stress, different from normal stressors, exerts a perpendicular force on the

Unraveling the neurotoxicity of titanium dioxide nanoparticles: focusing on molecular mechanisms

• Bin Song,
• Yanli Zhang,
• Jia Liu,
• Xiaoli Feng,
• Ting Zhou and
• Longquan Shao

Beilstein J. Nanotechnol. 2016, 7, 645–654, doi:10.3762/bjnano.7.57

• ultimately be induced. Long et al. [19][20] first revealed in their in vitro studies that TiO2 NPs can induce dose- and time-dependent elevations in H2O2 levels in BV2 cells (an immortalized brain microglia cell line). BV2 internalized TiO2 NPs and subsequently swollen mitochondria were detected by

• found that prenatal exposure to TiO2 NPs could alter the expression of neurotransmitter genes as well as genes associated with apoptosis, OS, and psychiatric disorders. TiO2 NPs decreased cell viability in PC12 cells in a dose- and time-dependent manner by increasing the level of ROS and proportion of

Nanoscale effects in the characterization of viscoelastic materials with atomic force microscopy: coupling of a quasi-three-dimensional standard linear solid model with in-plane surface interactions

• Santiago D. Solares

Beilstein J. Nanotechnol. 2016, 7, 554–571, doi:10.3762/bjnano.7.49

• the latter penetrates deeper into the surface. For a spherical tip, for example, each SLS element interacting with the tip follows a time-dependent relaxation similar to that of a simple SLS element [14][22], with a time delay for the onset of deformation and with decreasing indentation for each

• illustrates the time-dependent relaxation behavior of the surface element directly under the tip (Figure 8b), the oscillation amplitude and phase (Figure 8c and Figure 8d, respectively), the peak force within one fundamental oscillation (Figure 8e), and the maximum indentation within one fundamental

Charge and heat transport in soft nanosystems in the presence of time-dependent perturbations

• Alberto Nocera,
• Carmine Antonio Perroni,
• Vincenzo Marigliano Ramaglia and
• Vittorio Cataudella

Beilstein J. Nanotechnol. 2016, 7, 439–464, doi:10.3762/bjnano.7.39

• . Effects of the electron–vibration coupling on the charge and heat transport of soft nanoscopic systems are theoretically investigated in the presence of time-dependent perturbations, such as a forcing antenna or pumping terms between the leads and the nanosystem. A well-established approach valid for non

• -equilibrium adiabatic regimes is generalized to the case where external time-dependent perturbations are present. Then, a number of relevant applications of the method are reviewed for systems composed by a quantum dot (or molecule) described by a single electronic level coupled to a vibrational mode. Results

• : Before introducing time-dependent perturbations, the range of validity of the adiabatic approach is discussed showing that a very good agreement with the results of an exact quantum calculation is obtained in the limit of low level occupation. Then, we show that the interplay between the low frequency

Hemolysin coregulated protein 1 as a molecular gluing unit for the assembly of nanoparticle hybrid structures

• Tuan Anh Pham,
• Andreas Schreiber,
• Elena V. Sturm (née Rosseeva),
• Stefan Schiller and
• Helmut Cölfen

Beilstein J. Nanotechnol. 2016, 7, 351–363, doi:10.3762/bjnano.7.32

• network as a catalyst in the reduction reaction of 4-nitrophenol. The reduction of 4-nitrophenol to 4-aminophenol is a standard reaction to evaluate the catalytic reactivity of NPs [34]. The evaluation is based on the time-dependent absorbance decrease of the 4-nitrophenol cation at 400 nm. The absorbance

• network. A) UV–vis spectra of a 4-nitrophenol solution at different reaction times after the addition of the catalyst showing decreased absorbance. B) The time-dependent absorbance change at 400 nm in a mixture with pure Au NPs and the Au network as catalyst. A) and B) SEM image and EDX analysis of Fe3O4

Molecular machines operating on the nanoscale: from classical to quantum

• Igor Goychuk

Beilstein J. Nanotechnol. 2016, 7, 328–350, doi:10.3762/bjnano.7.31

• directed currents due to broken time–space symmetries has been born. In an immediate follow-up work [44], we have, however, observed that in the above case, the directed current is produced only by breaking the time-reversal symmetry by time-dependent driving, but not otherwise. The breaking of the spatial

• modulation of the energy levels is now analyzed. The physical background of the idea of adiabatic operation is sound. However, can it be realized in popular models characterized by discrete energy levels? The minimalist model contains just one time-dependent energy

Time-dependent growth of crystalline Au⁰-nanoparticles in cyanobacteria as self-reproducing bioreactors: 2. Anabaena cylindrica

• Liz M. Rösken,
• Felix Cappel,
• Susanne Körsten,
• Christian B. Fischer,
• Andreas Schönleber,
• Sander van Smaalen,
• Stefan Geimer,
• Christian Beresko,
• Georg Ankerhold and
• Stefan Wehner

Beilstein J. Nanotechnol. 2016, 7, 312–327, doi:10.3762/bjnano.7.30

• (XRD), transmission electron microscopy (TEM) and laser-induced breakdown spectroscopy (LIBS) are applied to monitor the time-dependent development of gold nanoparticles for up to 40 hours. Some vegetative cells (VC) are filled with nanoparticles within minutes, while the extracellular polymeric

• observation of XRD and TEM that nanoparticle formation takes place in the first few hours after exposure to Au3+. As seen in Figure 6 the amount of gold is continuously increasing over the first two hours for Anabaena cylindrica. The time-dependent development seems to be the same for a ten times smaller

• . The time-dependent growth of nanoparticles and the distribution of their size were examined for the first time on a time scale of hours up to at least two days of incubation. TEM reveals a large variation between individual cells and most nanoparticles are found in vegetative cells and not in the

A simple and efficient quasi 3-dimensional viscoelastic model and software for simulation of tapping-mode atomic force microscopy

• Santiago D. Solares

Beilstein J. Nanotechnol. 2015, 6, 2233–2241, doi:10.3762/bjnano.6.229

• analytical models cannot reproduce stress relaxation and creep [10][11]. Within AFM, this means that when the tip and sample are held in contact at a fixed relative position, the model must exhibit a time-dependent reduction in the stress (stress relaxation). Additionally, when the tip and sample are held in

• contact at a fixed stress, the model must exhibit a time-dependent relaxation of the position of the sample directly under the tip. That is, the sample must yield, allowing the tip to gradually increase the depth of indentation. Furthermore, if the tip is quickly removed following yielding of the surface

Magnetic reversal dynamics of a quantum system on a picosecond timescale

• Nikolay V. Klenov,
• Alexey V. Kuznetsov,
• Igor I. Soloviev,
• Sergey V. Bakurskiy and
• Olga V. Tikhonova

Beilstein J. Nanotechnol. 2015, 6, 1946–1956, doi:10.3762/bjnano.6.199

• the stationary states and , respectively, and the time-dependent probability amplitudes of the eigenstates a(t) and b(t) obey the condition |a(t)|2 + |b(t)|2 = 1. We suppose (see Figure 1) that at t = tin an external magnetic field, H(t), directed along the OX axis, starts to act on the system and

• (when ωl = 0) became critical in recent years in connection with the possibility to create magnetic field pulses of picosecond duration [16]. The time-dependent field is then given by: In matrix notation the problem looks quite simple: where . In the general case, this problem cannot be analytically

• solved due to the presence of the complex exponential function. We seek the approximate solution of Equation 10 in the form of the matrix exponential representation: where the matrix exponent can be understood as a sum where the time-dependent matrix A(t) obeys the differential equation . The solution

Synthesis, characterization and in vitro effects of 7 nm alloyed silver–gold nanoparticles

• Simon Ristig,
• Svitlana Chernousova,
• Wolfgang Meyer-Zaika and
• Matthias Epple

Beilstein J. Nanotechnol. 2015, 6, 1212–1220, doi:10.3762/bjnano.6.124

• is possible that a passivating effect from the alloyed gold is responsible for these observations. Future studies on the time-dependent dissolution of such alloyed nanoparticles in biological media may help to better understand this effect. Experimental Chemicals We used silver nitrate (Roth, p.a

Tunable magnetism on the lateral mesoscale by post-processing of Co/Pt heterostructures

• Oleksandr V. Dobrovolskiy,
• Maksym Kompaniiets,
• Roland Sachser,
• Fabrizio Porrati,
• Christian Gspan,
• Harald Plank and
• Michael Huth

Beilstein J. Nanotechnol. 2015, 6, 1082–1090, doi:10.3762/bjnano.6.109

• °C, and dropped to 70–90 μΩ·cm after 10 oxygen pulses. Figure 3 depicts the time-dependent normalized conductance of the Pt layer of sample C during the purification process. The post-processed Pt layers exhibited a nano-porous structure and a reduction of height from 50 ± 1.5 nm to 11 ± 1.5 nm, as

• in this work. Throughout the text the samples are referred to by their labels A, B, C, and D, as indicated. SEM images of the samples. The 500 × 860 nm2 insets show the morphology of the post-processed Co/Pt FEBID nano-stripes in the middle of the overlap of the nano-stripes. Time-dependent

From lithium to sodium: cell chemistry of room temperature sodium–air and sodium–sulfur batteries

• Philipp Adelhelm,
• Pascal Hartmann,
• Conrad L. Bender,
• Martin Busche,
• Christine Eufinger and
• Juergen Janek

Beilstein J. Nanotechnol. 2015, 6, 1016–1055, doi:10.3762/bjnano.6.105

• different discharge products decompose at different potentials during charging. The matrix certainly includes some simplifications: side reactions might be time dependent, the voltage profile can change during cycling, overpotential increases with current density, etc. However, the matrix allows for a

Effects of swift heavy ion irradiation on structural, optical and photocatalytic properties of ZnO–CuO nanocomposites prepared by carbothermal evaporation method

• Sini Kuriakose,
• D. K. Avasthi and
• Satyabrata Mohapatra

Beilstein J. Nanotechnol. 2015, 6, 928–937, doi:10.3762/bjnano.6.96

• estimating the band gap energies. Raman spectra from pristine and irradiated ZnO–CuO nanocomposite samples. Growth mechanism of ZnO nanorods and nanosheets in the nanocomposites. (a–e) UV–visible absorption spectra showing the sun-light-driven time-dependent photocatalytic degradation of MB dye through

• pristine and irradiated ZnO–CuO nanocomposite samples as photocatalysts. (f) Kinetics of the photocatalytic degradation of MB shown through time dependent variation of C/C0. (g) Repetitive tests using 3 × 1013 ions/cm2 irradiated sample for two runs of photocatalytic degradation studies on MB dye. (a–d) UV

• -visible absorption spectra showing sun light driven time dependent photocatalytic degradation of MO dye using the pristine and irradiated ZnO-CuO nanocomposite samples as photocatalysts. (e) Kinetics of photocatalytic degradation of MO dye shown through time dependent variation of C/C0. (f) Repetitive

Electron-stimulated purification of platinum nanostructures grown via focused electron beam induced deposition

• Brett B. Lewis,
• Michael G. Stanford,
• Jason D. Fowlkes,
• Kevin Lester,
• Harald Plank and
• Philip D. Rack

Beilstein J. Nanotechnol. 2015, 6, 907–918, doi:10.3762/bjnano.6.94

• -deposition electron exposure treatment in a localized oxygen ambient at room temperature. Time-dependent studies demonstrate that the process occurs from the top–down. Electron beam energy and current studies demonstrate that the process is controlled by a confluence of the electron energy loss and oxygen

Protein corona – from molecular adsorption to physiological complexity

• Lennart Treuel,
• Dominic Docter,
• Michael Maskos and
• Roland H. Stauber

Beilstein J. Nanotechnol. 2015, 6, 857–873, doi:10.3762/bjnano.6.88

• compositional changes has been shaped by Vroman in 1962 [164] who described the time-dependent composition of a protein layer. This description is commonly referred to as “Vroman effect” and it suggests that the bound protein layer is dominated by highly abundant proteins at short exposure times which are later

• all consisting of HSA with just minor chemical modifications as described above. Internalization of HSAam-coated NPs by the cells was completely suppressed within the sensitivity limits of their experiment. In addition the time-dependent NP uptake by HeLa cells was investigated, using spinning disk

Production, detection, storage and release of spin currents

• Michele Cini

Beilstein J. Nanotechnol. 2015, 6, 736–743, doi:10.3762/bjnano.6.75

• the connection is not symmetric. Moreover, properly connected rings can be used to pump currents in the wires giving raise to a number of interesting new phenomena. At half filling using a time-dependent magnetic field in the plane of the ring one can pump a pure spin current, excited by the the spin

• driven by a time-dependent magnetic field. Geometry and dynamics of spin current generation In this Section, I recall the Hamiltonian Hprod, the same as in [12], which, in the half filling case, describes the magnetic production of the spin current based on a quantum pumping effect in the absence of an

• on spin and is: with the Bohr magneton μB = 5.79375 · 10−5 eV/T. The time-dependent field lies in the plane of the ring and has no flux through it. However, it couples to the electron spins in the ring, where the magnetic spin-flip combined with the spin–orbit interaction excites the spin current

Entropy effects in the collective dynamic behavior of alkyl monolayers tethered to Si(111)

• Christian Godet

Beilstein J. Nanotechnol. 2015, 6, 583–594, doi:10.3762/bjnano.6.60

• ] and measurements can be performed in a well-defined metal/OML/semiconductor planar configuration, which is relevant for molecular electronics devices. Admittance spectroscopy provides insights in the modulation of localized charge density and dipole reorientation in a system submitted to a time

• -dependent electric field. Dissipation (energy loss) mechanisms can be described by using equivalent representations of the complex admittance, including the dielectric permittivity ε* and electrical modulus M*. Dipole reorientation requires an activation of the system with energy barriers related either to