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Search for "barrier" in Full Text gives 521 result(s) in Beilstein Journal of Nanotechnology. Showing first 200.

Plant growth regulation by seed coating with films of alginate and auxin-intercalated layered double hydroxides

  • Vander A. de Castro,
  • Valber G. O. Duarte,
  • Danúbia A. C. Nobre,
  • Geraldo H. Silva,
  • Vera R. L. Constantino,
  • Frederico G. Pinto,
  • Willian R. Macedo and
  • Jairo Tronto

Beilstein J. Nanotechnol. 2020, 11, 1082–1091, doi:10.3762/bjnano.11.93

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  • forms a barrier that decreases the absorption of H2O and the passage of O2. Consequently, the activation of enzymes, the respiration of the plant cells, and the cell duplication slow down. These factors delay the embryonic development of the plant and, subsequently, the quantity and speed of the
  • applied concentration (2.7 × 10−3 mg·L−1). Untreated seeds (control) and the seeds coated with the M3 film showed better performance than seeds coated with the M4 film. The coating acted as a physical barrier, hindering water absorption by the seeds, but also preventing the degradation of NAA, which is
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Published 24 Jul 2020

Monolayers of MoS2 on Ag(111) as decoupling layers for organic molecules: resolution of electronic and vibronic states of TCNQ

  • Asieh Yousofnejad,
  • Gaël Reecht,
  • Nils Krane,
  • Christian Lotze and
  • Katharina J. Franke

Beilstein J. Nanotechnol. 2020, 11, 1062–1071, doi:10.3762/bjnano.11.91

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  • Figure 3a) on the sample held at 230 K leads to large densely packed molecular islands on the MoS2 areas (Figure 3b). The large size and high degree of order of these islands reflects a low diffusion barrier on the MoS2 substrate. The moiré pattern of MoS2 remains intact and visible through the molecular
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Published 20 Jul 2020

Microwave photon detection by an Al Josephson junction

  • Leonid S. Revin,
  • Andrey L. Pankratov,
  • Anna V. Gordeeva,
  • Anton A. Yablokov,
  • Igor V. Rakut,
  • Victor O. Zbrozhek and
  • Leonid S. Kuzmin

Beilstein J. Nanotechnol. 2020, 11, 960–965, doi:10.3762/bjnano.11.80

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  • anomalously large lifetime, not described by the Kramers’ theory for the escape time over a barrier under the influence of fluctuations. We explain it by the phase diffusion regime, which is evident from the temperature dependence of the switching current histograms. Therefore, phase diffusion allows for a
  • the particle at rest in one well of the potential. The exit from this metastable state corresponds to the appearance of a finite voltage at the junction. In the case of low damping (but depending also on the barrier height and noise intensity), the particle, jumping over the barrier, gains enough
  • then relax into one of the potential minima [24]. When barrier and noise are large, the exit from the well and the subsequent retrapping processes may occur many times at a given bias current. The most evident signature of the phase diffusion phenomenon is the temperature dependence of the switching
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Published 23 Jun 2020

Key for crossing the BBB with nanoparticles: the rational design

  • Sonia M. Lombardo,
  • Marc Schneider,
  • Akif E. Türeli and
  • Nazende Günday Türeli

Beilstein J. Nanotechnol. 2020, 11, 866–883, doi:10.3762/bjnano.11.72

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  • Central nervous system diseases are a heavy burden on society and health care systems. Hence, the delivery of drugs to the brain has gained more and more interest. The brain is protected by the blood–brain barrier (BBB), a selective barrier formed by the endothelial cells of the cerebral microvessels
  • nanoparticles (AuNPs); blood–brain barrier (BBB); drug delivery; liposomes; nanomedicine; polymeric nanoparticles; solid lipid nanoparticles; superparamagnetic iron oxide nanoparticles (SPIONs); Introduction Neurological disorders and brain diseases are real burdens for modern societies and healthcare systems
  • damaged by ischemia [2]. One of the main limitations for the treatment of neurological disorders is the difficulty to deliver drugs to the brain. The brain is surrounded by the blood–brain barrier (BBB), a selective barrier formed by the endothelial cells of the cerebral microvessels [3][4]. The surface
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Published 04 Jun 2020

Effect of Ag loading position on the photocatalytic performance of TiO2 nanocolumn arrays

  • Jinghan Xu,
  • Yanqi Liu and
  • Yan Zhao

Beilstein J. Nanotechnol. 2020, 11, 717–728, doi:10.3762/bjnano.11.59

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  • electrons are injected intoTiO2, so the electric field intensity at the interface between Ag and TiO2 is the highest. Figure 9a shows the photoelectric energy conversion of the Ag–TiO2 structure. The contact between Ag and the n-type semiconductor TiO2 will form a Schottky barrier at the interface, which
  • results in the bending of the energy band of TiO2 [37]. Due to the influence of SPR and LSPR effects, Ag can absorb visible light and make the electron near the Fermi level transition to a higher level [38]. When the high-level electrons have enough energy, the electrons will cross the Schottky barrier
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Published 05 May 2020
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  • heterojunctions of armchair graphene and boron nitride nanoribbons, exhibiting negative differential resistance is proposed. Low-bandgap armchair graphene nanoribbons and high-bandgap armchair boron nitride nanoribbons are used to design the well and the barrier region, respectively. The effect of all possible
  • between two potential barriers, forming a so-called double-barrier quantum well structure. In the well, the energy of the electrons is quantized due to the quantum confinement of their wave function. Incident electrons with energies equal to the quantized levels of the well pass through the barriers with
  • heterojunctions perpendicular to the transport direction (Figure 1), which are required to construct the double-barrier quantum well structure. Calculation Method Figure 1a schematically shows the structure of the proposed RTD. An AGNR of 19 carbon atoms in width (19-AGNR) and four hexagonal carbon rings in
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Published 24 Apr 2020

Comparison of fresh and aged lithium iron phosphate cathodes using a tailored electrochemical strain microscopy technique

  • Matthias Simolka,
  • Hanno Kaess and
  • Kaspar Andreas Friedrich

Beilstein J. Nanotechnol. 2020, 11, 583–596, doi:10.3762/bjnano.11.46

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  • ESM data. The ESM signal, which we observe on carbon-coated LFP, is not only limited to structural boundaries within one single grain, which are known to exhibit a high mobility for ions due to structural disordering, high concentration of defects and lower energy barrier [40][54][55]. We also observe
  • signal is produced. The olivine crystal structure on the planar locations is not the only influence on the ionic mobility, but it is an additional factor next to the structural disordering, high concentration of defects and lower energy barrier and more important on planar locations than on structural
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Published 07 Apr 2020

Interfacial charge transfer processes in 2D and 3D semiconducting hybrid perovskites: azobenzene as photoswitchable ligand

  • Nicole Fillafer,
  • Tobias Seewald,
  • Lukas Schmidt-Mende and
  • Sebastian Polarz

Beilstein J. Nanotechnol. 2020, 11, 466–479, doi:10.3762/bjnano.11.38

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  • . The most likely explanation are steric factors. The photoisomerisation requires freedom to move for the molecular groups. The space within the layers is so limited that the activation barrier becomes too high and thus photoswitching cannot take place. Weaker π-stacking in 2D-AzoOC4 and 2D-AzoOC12
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Published 17 Mar 2020

DFT calculations of the structure and stability of copper clusters on MoS2

  • Cara-Lena Nies and
  • Michael Nolan

Beilstein J. Nanotechnol. 2020, 11, 391–406, doi:10.3762/bjnano.11.30

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  • applications. These materials are also interesting as supports for low-dimensional metals for catalysis, while recent work has shown increased interest in using 2D materials in the electronics industry as a Cu diffusion barrier in semiconductor device interconnects. The interaction between different metal
  • between the adsorption of single Cu atoms and the adsorption of larger structures from the publications discussed above. We choose the Cu–MoS2 ML system due to its potential significance for the electronics industry as a copper diffusion barrier [12][13][14][15]. Studying small Cun (n = 1–4) structures
  • (DOS) analysis shows the emergence of mid-gap states, indicating that the system is changing from semiconducting to metallic as Cu atoms are adsorbed, making it suitable for application as a Cu diffusion barrier. Computational Methods All calculations, for bulk MoS2 and the 2D monolayer, were carried
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Published 26 Feb 2020

Poly(1-vinylimidazole) polyplexes as novel therapeutic gene carriers for lung cancer therapy

  • Gayathri Kandasamy,
  • Elena N. Danilovtseva,
  • Vadim V. Annenkov and
  • Uma Maheswari Krishnan

Beilstein J. Nanotechnol. 2020, 11, 354–369, doi:10.3762/bjnano.11.26

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  • is overexpressed in many types of cancer including lung cancer [44]. Gremlin1 is involved in the survival of the tumor cells and promotes the formation of the stromal barrier [44]. It has also been identified as an agonist of VEGF and its receptor VEGFR2 [44]. Therefore, the VEGF silencing of the
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Published 17 Feb 2020

Interactions at the cell membrane and pathways of internalization of nano-sized materials for nanomedicine

  • Valentina Francia,
  • Daphne Montizaan and
  • Anna Salvati

Beilstein J. Nanotechnol. 2020, 11, 338–353, doi:10.3762/bjnano.11.25

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  • level [109][110]. Simulations showed a higher energy barrier for the internalization of soft and easily deformable nanoparticles than for that of rigid particles [151][152]. However, nanoparticle–cell interactions cannot be described solely by the energy barrier required to bend the lipid membrane
  • persist [122]. While this can be very useful when the target is the lysosomes, it is well known that lysosomal accumulation constitutes an ulterior barrier for the delivery of drugs to any other intracellular target [85][86]. This has led to the development of strategies to induce escape from the
  • [201][202][203]. Another important factor known to affect uptake pathways by cells in vitro is the differentiation of cells into barriers and the resulting cell polarization [159]. Uptake by cells grown to a polarized cell barrier is, in fact, different than uptake by the same cells when grown isolated
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Published 14 Feb 2020

An advanced structural characterization of templated meso-macroporous carbon monoliths by small- and wide-angle scattering techniques

  • Felix M. Badaczewski,
  • Marc O. Loeh,
  • Torben Pfaff,
  • Dirk Wallacher,
  • Daniel Clemens and
  • Bernd M. Smarsly

Beilstein J. Nanotechnol. 2020, 11, 310–322, doi:10.3762/bjnano.11.23

Graphical Abstract
  • lead to unfavorable bottlenecks. These narrow bottlenecks can act as a barrier for larger molecules, which block the pore access and lower the pore connectivity. Therefore, we want to investigate the adsorption behavior of monolithic carbon materials for larger molecules in comparison to typical gas
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Published 10 Feb 2020

Using gold nanoparticles to detect single-nucleotide polymorphisms: toward liquid biopsy

  • María Sanromán Iglesias and
  • Marek Grzelczak

Beilstein J. Nanotechnol. 2020, 11, 263–284, doi:10.3762/bjnano.11.20

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  • . Review Liquid biopsy Tissue biopsy is the state-of-the-art protocol in clinics for the evaluation of tumor progression. This procedure, however, constitutes a significant barrier for monitoring oncogenic mutations since it can introduce clinical risks for the patient [4], heterogeneity of tumor cells [5
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Published 31 Jan 2020

Anomalous current–voltage characteristics of SFIFS Josephson junctions with weak ferromagnetic interlayers

  • Tairzhan Karabassov,
  • Anastasia V. Guravova,
  • Aleksei Yu. Kuzin,
  • Elena A. Kazakova,
  • Shiro Kawabata,
  • Boris G. Lvov and
  • Andrey S. Vasenko

Beilstein J. Nanotechnol. 2020, 11, 252–262, doi:10.3762/bjnano.11.19

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  • Physical Institute, Russian Academy of Sciences, 119991 Moscow, Russia 10.3762/bjnano.11.19 Abstract We present a quantitative study of the current–voltage characteristics (CVC) of SFIFS Josephson junctions (S = bulk superconductor, F = metallic ferromagnet, I = insulating barrier) with weak ferromagnetic
  • interlayers in the diffusive limit. The problem is solved in the framework of the nonlinear Usadel equations. We consider the case of a strong tunnel barrier such that the left SF and the right FS bilayers are decoupled. We calculate the density of states (DOS) in SF bilayers using a self-consistent numerical
  • situation is resolved by addition of an insulating barrier (I) yielding a SFIFS layer sequence, which allows one to realize much larger values of the product IcRn, where Ic is the critical current of the junction and Rn its normal state resistance [36][37][38]. Recently, SIFS junctions attracted much
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Published 23 Jan 2020

Rational design of block copolymer self-assemblies in photodynamic therapy

  • Maxime Demazeau,
  • Laure Gibot,
  • Anne-Françoise Mingotaud,
  • Patricia Vicendo,
  • Clément Roux and
  • Barbara Lonetti

Beilstein J. Nanotechnol. 2020, 11, 180–212, doi:10.3762/bjnano.11.15

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Published 15 Jan 2020

Size effects of graphene nanoplatelets on the properties of high-density polyethylene nanocomposites: morphological, thermal, electrical, and mechanical characterization

  • Tuba Evgin,
  • Alpaslan Turgut,
  • Georges Hamaoui,
  • Zdenko Spitalsky,
  • Nicolas Horny,
  • Matej Micusik,
  • Mihai Chirtoc,
  • Mehmet Sarikanat and
  • Maria Omastova

Beilstein J. Nanotechnol. 2020, 11, 167–179, doi:10.3762/bjnano.11.14

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  • by increasing the content of all three GnPs. This was attributed to the high thermal stability of the GnPs, the GnPs’ shielding effect on the combustion gas diffusion into and out of the polymer during its thermal decomposition [18], the barrier effect of the GnPs, the removal of free radicals, which
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Published 14 Jan 2020

Internalization mechanisms of cell-penetrating peptides

  • Ivana Ruseska and
  • Andreas Zimmer

Beilstein J. Nanotechnol. 2020, 11, 101–123, doi:10.3762/bjnano.11.10

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  • influence the cellular uptake mechanism. Keywords: cell-penetrating peptides; direct translocation; drug delivery; endocytosis; internalization; Introduction The cell membrane is a semipermeable barrier, serving as a protective layer for the cells. It is an essential organelle for cell survival and
  • function. As a barrier, it only allows the transport of compounds with small molecular size, which can be transported using channels and specific carriers [1][2]. Macromolecules, however, are unable to use these modes of entry [2]. The production of novel therapeutic molecules, which do not adhere to the
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Published 09 Jan 2020

Recent progress in perovskite solar cells: the perovskite layer

  • Xianfeng Dai,
  • Ke Xu and
  • Fanan Wei

Beilstein J. Nanotechnol. 2020, 11, 51–60, doi:10.3762/bjnano.11.5

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  • perovskite crystallization process to fabricate films of superior quality and controllable morphology. Deng et al. [13] produced efficient PSCs with diisopropyl ether as the antisolvent, which perfectly overcome this barrier. As shown in Figure 2, perovskite films fabricated by an antisolvent deposition
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Published 06 Jan 2020

Advanced hybrid nanomaterials

  • Andreas Taubert,
  • Fabrice Leroux,
  • Pierre Rabu and
  • Verónica de Zea Bermudez

Beilstein J. Nanotechnol. 2019, 10, 2563–2567, doi:10.3762/bjnano.10.247

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  • hydrophobicity and lipophilicity. Exfoliated nanosheets of layered calcium phenylphosphonate assisted by solvent were used in “Layered calcium phenylphosphonate: a hybrid material for a new generation of nanofillers” to promote the mechanical properties and improve the barrier effect for applications such as
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Published 20 Dec 2019

Frontiers in pharmaceutical nanotechnology

  • Matthias G. Wacker

Beilstein J. Nanotechnol. 2019, 10, 2538–2540, doi:10.3762/bjnano.10.244

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  • science. They have fundamentally changed our understanding of the way dosage forms can facilitate drug therapy. Prof. Jörg Kreuter has been a pioneer in this research area and dedicated his life’s work to nanoparticle research and the blood–brain barrier [2]. One of his most outstanding discoveries, the
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Published 17 Dec 2019

Synthesis and acetone sensing properties of ZnFe2O4/rGO gas sensors

  • Kaidi Wu,
  • Yifan Luo,
  • Ying Li and
  • Chao Zhang

Beilstein J. Nanotechnol. 2019, 10, 2516–2526, doi:10.3762/bjnano.10.242

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  • sensors show an enhanced response when the temperature is increased from 150 to 200 °C, while for the pure ZnFe2O4 sensor the response has a maximum at 175 °C. This tendency is ascribed to the higher surface activation energy at elevated temperature. As a result, the activation energy barrier of surface
  • will also exist a potential barrier at the grain boundaries. In Figure 11b, when air is introduced, the resistance of the sensor will decrease as a result of the construction of the depletion layers and the potential barriers at the grain boundaries (see also Equations 2–5). When acetone is introduced
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Published 16 Dec 2019

Formation of metal/semiconductor Cu–Si composite nanostructures

  • Natalya V. Yumozhapova,
  • Andrey V. Nomoev,
  • Vyacheslav V. Syzrantsev and
  • Erzhena C. Khartaeva

Beilstein J. Nanotechnol. 2019, 10, 2497–2504, doi:10.3762/bjnano.10.240

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  • microwave electronics and radiophotonics due to their large dipole moment and the appearance of a Schottky barrier in the contact region [14]. The structure of these nanoparticles is primarily determined by the methods and conditions of synthesis, which should allow us to combine the two materials even if
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Published 13 Dec 2019

Integration of sharp silicon nitride tips into high-speed SU8 cantilevers in a batch fabrication process

  • Nahid Hosseini,
  • Matthias Neuenschwander,
  • Oliver Peric,
  • Santiago H. Andany,
  • Jonathan D. Adams and
  • Georg E. Fantner

Beilstein J. Nanotechnol. 2019, 10, 2357–2363, doi:10.3762/bjnano.10.226

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  • oxidation sharpening [29]. Studies report a 30% decrease of the oxide thickness along the sharp silicon ridges after wet oxidation at 900–950 °C [30]. This decrease is due to an increase of the activation barrier of the interfacial reactions induced by the stress build-up in these areas [31]. Due to the
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Published 29 Nov 2019

Microfluidics as tool to prepare size-tunable PLGA nanoparticles with high curcumin encapsulation for efficient mucus penetration

  • Nashrawan Lababidi,
  • Valentin Sigal,
  • Aljoscha Koenneke,
  • Konrad Schwarzkopf,
  • Andreas Manz and
  • Marc Schneider

Beilstein J. Nanotechnol. 2019, 10, 2280–2293, doi:10.3762/bjnano.10.220

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  • diffusion in the mixing channel after a certain channel length (longer mixing times). In addition, the small particles produced in microfluidics were perfectly suited to diffuse through pulmonary mucus as a biological barrier without being immobilized. NPs of approximately 60 nm in diameter have
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Published 19 Nov 2019

Ultrathin Ni1−xCoxS2 nanoflakes as high energy density electrode materials for asymmetric supercapacitors

  • Xiaoxiang Wang,
  • Teng Wang,
  • Rusen Zhou,
  • Lijuan Fan,
  • Shengli Zhang,
  • Feng Yu,
  • Tuquabo Tesfamichael,
  • Liwei Su and
  • Hongxia Wang

Beilstein J. Nanotechnol. 2019, 10, 2207–2216, doi:10.3762/bjnano.10.213

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  • the material can shorten the ion diffusion path lengths, overcoming the kinetics barrier of the faradaic redox reaction for most of the energy storage materials. The hierarchical nanostructure can provide abundant surface active sites for electrochemical reactions during the charge/discharge process
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Published 11 Nov 2019
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