An adapted Coffey model for studying susceptibility losses in interacting magnetic nanoparticles

• Mihaela Osaci and
• Matteo Cacciola

Beilstein J. Nanotechnol. 2015, 6, 2173–2182, doi:10.3762/bjnano.6.223

• magnitude of the applied field, respectively, μ0 is the magnetic permeability of free space, τeff is the average effective magnetic relaxation time of the nanoparticle system, and χ0 is the equilibrium average magnetic susceptibility of the nanoparticle assembly [3][9]: In Equation 2, rV is the volume

• vectors of the magnetic moments of the nanoparticles i and j, respectively, and μ0 is the magnetic permeability of vacuum. Due to clinical limitations on the amplitude of the external magnetic field Hext [4][6][10], the anisotropy axes of the spherical nanoparticles are not perfectly aligned to the

Selective porous gates made from colloidal silica nanoparticles

• Roberto Nisticò,
• Paola Avetta,
• Paola Calza,
• Debora Fabbri,
• Giuliana Magnacca and
• Dominique Scalarone

Beilstein J. Nanotechnol. 2015, 6, 2105–2112, doi:10.3762/bjnano.6.215

• characterized by a depth filter-like structure with internal porosity due to interparticle voids. Permeability and size-selectivity were studied by monitoring the diffusion of probe molecules under standard conditions and under the application of an external stimulus (i.e., electric field). Promising results

• commercial Si3N4 microsieves for membrane applications. Moreover, permeability and size-selectivity were studied by monitoring the diffusion of different probe molecules under standard conditions and under the application of an electric field as external stimulus. Selected probe molecules were the cationic

• separation processes and dosing of chemicals. In this study, the surface functionalization of silicon nitride commercial microsieves by means of colloidal silica nanoparticles has been proposed as a novel strategy to fabricate composite membranes for microfluidic devices. The permeability and size

Radiation losses in the microwave K_u band in magneto-electric nanocomposites

• Talwinder Kaur,
• Sachin Kumar,
• Jyoti Sharma and
• A. K. Srivastava

Beilstein J. Nanotechnol. 2015, 6, 1700–1707, doi:10.3762/bjnano.6.173

• initial permeability, line width, domain-wall displacement and coercive force. The new absorption mechanism arises from the reduced particle size in nanometre range. The natural resonance frequency of barium hexaferrite lies in the range of 50–60 GHz because of the large magneto-crystalline anisotropy and

• energy. Reflection loss calculation has been carried out by using the input impedance from the following relations in accordance with theory of absorbing wall [41]: where Z is the normalized input impedance, ε* is complex permittivity and µ* is the complex permeability, λ is the wavelength and tis the

• thickness of the sample pellet. It has been observed from XRD and VNA analysis that reflection loss depends on size of the crystallite size. Permittivity and permeability are calculated according to Nicholson–Ross–Weir method. Figure 7 is showing the real (µ′) and the imaginary part (µ″) of the complex

PLGA nanoparticles as a platform for vitamin D-based cancer therapy

• Maria J. Ramalho,
• Joana A. Loureiro,
• Bárbara Gomes,
• Manuela F. Frasco,
• Manuel A. N. Coelho and
• M. Carmo Pereira

Beilstein J. Nanotechnol. 2015, 6, 1306–1318, doi:10.3762/bjnano.6.135

• internalized by targeted cells, increasing intracellular drug delivery [20], allowing a sustained and controlled drug release over time [19]. Moreover, PLGA NPs could offer selective drug delivery to tumor tissue either by passive targeting with the enhanced permeability and retention effect (EPR) [18] or by

Interaction of electromagnetic radiation in the 20–200 GHz frequency range with arrays of carbon nanotubes with ferromagnetic nanoparticles

• Agylych Atdayev,
• Alexander L. Danilyuk and
• Serghej L. Prischepa

Beilstein J. Nanotechnol. 2015, 6, 1056–1064, doi:10.3762/bjnano.6.106

• form resonance resistive–inductive–capacitive circuits. It is shown that the influence of the resonant circuits leads to the emergence of specific resonances, namely peaks and valleys in the frequency dependence of the permeability of the nanocomposite, and in the frequency dependence of the reflection

• permeability and permittivity of the nanocomposite taking into account the possible resistive, capacitive and inductive coupling between the components of the sample. Indeed, in the frequency range of tens or hundreds of GHz, the microwave properties of the nanocomposite should strongly depend not only on the

• of the same size and all interfaces have the same capacitance. Under these assumptions, the RiLiCi circuit describing the nanocomposite properties is resonant, that is, it has its own resonance frequency. To model the permeability of such a nanostructured composite, we obtained the following modified

Graphene quantum interference photodetector

• Mahbub Alam and
• Paul L. Voss

Beilstein J. Nanotechnol. 2015, 6, 726–735, doi:10.3762/bjnano.6.74

• volume of V, c is the speed of light, εr is the relative permittivity, μr is the relative permeability and ε is the absolute permittivity. The photon scattering functions, and , are calculated assuming monochromatic light and two energy levels for excitation. Both the acoustic phonon and optical phonon

Pulmonary surfactant augments cytotoxicity of silica nanoparticles: Studies on an in vitro air–blood barrier model

• Jennifer Y. Kasper,
• Lisa Feiden,
• Maria I. Hermanns,
• Christoph Bantz,
• Michael Maskos,
• Ronald E. Unger and
• C. James Kirkpatrick

Beilstein J. Nanotechnol. 2015, 6, 517–528, doi:10.3762/bjnano.6.54

• its inter-head groups, which causes a higher mobility of the N(CH3)3+ group terminus of the phospholipids. Consequently, silica alters the membrane permeability and the fluidity of the bilayers is decreased, which finally leads to membrane perturbation and disruption [36]. The latter can be sensed by

Dynamic force microscopy simulator (dForce): A tool for planning and understanding tapping and bimodal AFM experiments

• Horacio V. Guzman,
• Pablo D. Garcia and
• Ricardo Garcia

Beilstein J. Nanotechnol. 2015, 6, 369–379, doi:10.3762/bjnano.6.36

• –Verbey–Overbeek (DLVO) The DLVO force [46] describes interactions in liquid by including the contributions from the electrical double layer and the van der Waals interactions. The DLVO force is given by where λD is the Debye length, ε is the relative permeability, ε0 is the vacuum permeability, σt is the

The effect of surface charge on nonspecific uptake and cytotoxicity of CdSe/ZnS core/shell quantum dots

• Vladimir V. Breus,
• Anna Pietuch,
• Marco Tarantola,
• Thomas Basché and
• Andreas Janshoff

Beilstein J. Nanotechnol. 2015, 6, 281–292, doi:10.3762/bjnano.6.26

• membrane permeability assays. We demonstrate that these methods, however, can overlook other more subtle impacts on cell viability and metabolism caused by binding of QDs to cellular compartments, without release of Cd2+ ions. In the present study, we use a noninvasive and label-free impedance setup to

Boosting the local anodic oxidation of silicon through carbon nanofiber atomic force microscopy probes

• Gemma Rius,
• Matteo Lorenzoni,
• Soichiro Matsui,
• Masaki Tanemura and
• Francesc Perez-Murano

Beilstein J. Nanotechnol. 2015, 6, 215–222, doi:10.3762/bjnano.6.20

• thickness of grown SiOx is not only the decrease of the strength of the electric field as the SiOx becomes thicker, but also other self-limiting mechanism which decrease the permeability of the hydroxy anions at a given electric field, such as charge build-up in the oxide [21]. Furthermore, one concern when

Synthesis of boron nitride nanotubes and their applications

• Saban Kalay,
• Zehra Yilmaz,
• Ozlem Sen,
• Melis Emanet,
• Emine Kazanc and
• Mustafa Çulha

Beilstein J. Nanotechnol. 2015, 6, 84–102, doi:10.3762/bjnano.6.9

• showed that the BNNTs have potential to carry new drugs or radioisotopes [86]. Electroporation is used for increasing the cell permeability for introduction of molecules into cells. However, it requires a high voltage, which is one of the problems for drug delivery. The applicability of BNNTs in an

Intake of silica nanoparticles by giant lipid vesicles: influence of particle size and thermodynamic membrane state

• Florian G. Strobl,
• Florian Seitz,
• Christoph Westerhausen,
• Armin Reller,
• Adriano A. Torrano,
• Christoph Bräuchle,
• Achim Wixforth and
• Matthias F. Schneider

Beilstein J. Nanotechnol. 2014, 5, 2468–2478, doi:10.3762/bjnano.5.256

• constant surface area can certainly not explain the observed massive particle uptake for all sizes. If we now assume the simple case that each fission event induces a pore with characteristic size and opening time, the permeability of the vesicle will scale linearly with N. Hence, it seems very plausible

• interactions and possible thermodynamic changes of the lipid membrane, which can result in drastic alterations of its physical properties (e.g., bending stiffness, permeability and spontaneous curvature). Even though the model system that was investigated here is quite distinct from a real cell membrane we

• concentration Cs of particles: where P denotes an effective membrane “permeability”, i.e., its affinity to particle uptake. Hence, one would expect an exponential decay of the vesicle surface area with a decay constant τ−1 = PCs: Fitting this equation to the experimental A(t)-curves yields the decay constants

Functionalized polystyrene nanoparticles as a platform for studying bio–nano interactions

• Cornelia Loos,
• Tatiana Syrovets,
• Anna Musyanovych,
• Volker Mailänder,
• Katharina Landfester,
• G. Ulrich Nienhaus and
• Thomas Simmet

Beilstein J. Nanotechnol. 2014, 5, 2403–2412, doi:10.3762/bjnano.5.250

• lysosomes are capable of activating directly procaspases in vitro [61][62]. Another in vitro study showed that lysosomal enzymes can truncate Bid and activate Bax, the proapoptotic members of the Bcl2 family, which regulate the permeability of the mitochondrial membrane [63]. Lysosomal damage and activation

Nanoencapsulation of ultra-small superparamagnetic particles of iron oxide into human serum albumin nanoparticles

• Matthias G. Wacker,
• Mahmut Altinok,
• Stephan Urfels and
• Johann Bauer

Beilstein J. Nanotechnol. 2014, 5, 2259–2266, doi:10.3762/bjnano.5.235

• tumors due to the enhanced permeability and retention effect [5]. While circulating through the blood stream, these colloids undergo an opsonization by the immune system followed by endocytosis into macrophages. Particles of greater diameters are rapidly cleared from the plasma and smaller colloidal

Optical properties and electrical transport of thin films of terbium(III) bis(phthalocyanine) on cobalt

• Peter Robaschik,
• Pablo F. Siles,
• Daniel Bülz,
• Peter Richter,
• Manuel Monecke,
• Michael Fronk,
• Svetlana Klyatskaya,
• Daniel Grimm,
• Oliver G. Schmidt,
• Mario Ruben,
• Dietrich R. T. Zahn and
• Georgeta Salvan

Beilstein J. Nanotechnol. 2014, 5, 2070–2078, doi:10.3762/bjnano.5.215

• the Q and B band, of phthalocyanines are highlighted in Figure 2. They correspond to ligand-related π–π* transitions [15]. For organic semiconductors we can consider the relative magnetic permeability to be µr ≈ 1. Thus, we can easily determine the optical constants from the diagonal elements εii of

Effect of silver nanoparticles on human mesenchymal stem cell differentiation

• Christina Sengstock,
• Jörg Diendorf,
• Matthias Epple,
• Thomas A. Schildhauer and
• Manfred Köller

Beilstein J. Nanotechnol. 2014, 5, 2058–2069, doi:10.3762/bjnano.5.214

• rapidly to biomolecules, such as DNA [27], negatively charged cell-wall components and the sulfhydryl groups of metabolic enzymes [7][28][29], which results in the inhibition of DNA-replication, an increase in membrane permeability and the disturbance of different metabolic pathways [30]. In contrast to

Spin annihilations of and spin sifters for transverse electric and transverse magnetic waves in co- and counter-rotations

• Hyoung-In Lee and
• Jinsik Mok

Beilstein J. Nanotechnol. 2014, 5, 1887–1898, doi:10.3762/bjnano.5.199

• limits |q| → 0 and |q| → ∞ refer, respectively, to the pure TM and pure TE modes. Besides, |q|2 ≡ q*·q, and ε is the permittivity, which is positive for dielectric media so that ε ≡ n2 with n being the refractive index. In addition, μ = 1 is the permeability for non-magnetic materials. Note that both ε

Molecular biology approaches in bioadhesion research

• Marcelo Rodrigues,
• Birgit Lengerer,
• Thomas Ostermann and
• Peter Ladurner

Beilstein J. Nanotechnol. 2014, 5, 983–993, doi:10.3762/bjnano.5.112

• be required. Critical steps are the fixation and the achievement of permeability of the tissue without losing endogenous mRNA or structural tissue integrity. Usually, good results are achieved with a fixation using 4% paraformaldehyde and proteinase K treatment. Treatment times and concentrations

• vary depending on tissue hardness and size and must be empirically tested for every tissue. If permeability and transparency cannot be achieved in a whole mount specimen, it may be necessary to perform the ISH on tissue sections [48]. After pre-treatments of the tissue, the DIG-labelled RNA probe is

Manipulation of isolated brain nerve terminals by an external magnetic field using D-mannose-coated γ-Fe₂O₃ nano-sized particles and assessment of their effects on glutamate transport

• Tatiana Borisova,
• Natalia Krisanova,
• Arsenii Borуsov,
• Roman Sivko,
• Ludmila Ostapchenko,
• Michal Babic and
• Daniel Horak

Beilstein J. Nanotechnol. 2014, 5, 778–788, doi:10.3762/bjnano.5.90

• away, the inner magnetization of nanoparticles disappears, and therefore their agglomeration, which carries the risk of embolization of the capillary vessels, can be avoided [3]. A key issue for enhancing of permeability of iron oxide nanoparticles through the cell membrane is the modification of their

Hole-mask colloidal nanolithography combined with tilted-angle-rotation evaporation: A versatile method for fabrication of low-cost and large-area complex plasmonic nanostructures and metamaterials

• Jun Zhao,
• Bettina Frank,
• Frank Neubrech,
• Chunjie Zhang,
• Paul V. Braun and
• Harald Giessen

Beilstein J. Nanotechnol. 2014, 5, 577–586, doi:10.3762/bjnano.5.68

• based on metallic split-ring resonators (SRRs) were able to simultaneously demonstrate negative dielectric permittivity as well as magnetic permeability, which leads to a negative refractive index [11]. In hybrid solar cells and organic light emitting diodes, plasmonic nanostructures enhanced the

Near-infrared dye loaded polymeric nanoparticles for cancer imaging and therapy and cellular response after laser-induced heating

• Tingjun Lei,
• Alicia Fernandez-Fernandez,
• Romila Manchanda,
• Yen-Chih Huang and
• Anthony J. McGoron

Beilstein J. Nanotechnol. 2014, 5, 313–322, doi:10.3762/bjnano.5.35

• advantage of NPs is that they are passively targeted to tumor sites because of the enhanced permeability and retention (EPR) effect. This effect occurs as a result of a combination of factors, including increased pore sizes of tumor vasculature, fast tumor angiogenesis from increased secretion of vascular

En route to controlled catalytic CVD synthesis of densely packed and vertically aligned nitrogen-doped carbon nanotube arrays

• Slawomir Boncel,
• Sebastian W. Pattinson,
• Valérie Geiser,
• Milo S. P. Shaffer and
• Krzysztof K. K. Koziol

Beilstein J. Nanotechnol. 2014, 5, 219–233, doi:10.3762/bjnano.5.24

• areal density of up to 5 × 108 N-CNTs per mm2 in the array was gained for nanotubes of OD equal to 26 ± 15 nm grown at [Pz] = 5 wt % and [FeCp2] = 9.6 wt %. These results make N-CNTs the perfect construction material for separation membranes of tuneable permeability. N-CNTs of a high N-doping level can

Novel composite Zr/PBI-O-PhT membranes for HT-PEFC applications

• Mikhail S. Kondratenko,
• Igor I. Ponomarev,
• Marat O. Gallyamov,
• Dmitry Y. Razorenov,
• Yulia A. Volkova,
• Elena P. Kharitonova and
• Alexei R. Khokhlov

Beilstein J. Nanotechnol. 2013, 4, 481–492, doi:10.3762/bjnano.4.57

• design of an advanced membrane for HT-PEFC applications necessitates the finding of an appropriate compromise between proton conductivity on the one hand and good mechanical properties as well as low gas permeability on the other hand. Various PBI-based composites have been proposed in order to achieve

• low hydrogen permeability. Indeed, the measured hydrogen crossover-currents (Figure 9) are about 3 mA·cm−2 for all samples of the membranes. This is lower than the 4–5 mA·cm−2 reported by Neyerlin et al. [20] for PBI membranes from a commercial Celtec P-1000 MEA (BASF). Polarisation curves of fuel

Friction and durability of virgin and damaged skin with and without skin cream treatment using atomic force microscopy

• Bharat Bhushan,
• Si Chen and
• Shirong Ge

Beilstein J. Nanotechnol. 2012, 3, 731–746, doi:10.3762/bjnano.3.83

• epidermis, hair-follicle density, epidermal turnover kinetics, lipid composition and the biophysical properties of the lipids [27][28], and similar permeability, i.e., the fluxes through the skin and concentrations in the skin are of the same order of magnitude for both tissues [25][26]. Understanding the

Focused electron beam induced deposition: A perspective

• Michael Huth,
• Fabrizio Porrati,
• Christian Schwalb,
• Marcel Winhold,
• Roland Sachser,
• Maja Dukic,
• Jonathan Adams and
• Georg Fantner

Beilstein J. Nanotechnol. 2012, 3, 597–619, doi:10.3762/bjnano.3.70