Design and characterization of polymeric microneedles containing extracts of Brazilian green propolis

• Camila Felix Vecchi,
• Rafaela Said dos Santos,
• Jéssica Bassi da Silva and
• Marcos Luciano Bruschi

Beilstein J. Nanotechnol. 2022, 13, 503–516, doi:10.3762/bjnano.13.42

• Abstract Microneedles (MNs) are a means to break the protective skin barrier in a minimally invasive way. By creating temporary micropores, they make biologically active agents available in the skin layers. Propolis (PRP) is a gum resin with a complex chemical composition, produced by bees Apis mellifera L

• holes created and will be taken, by diffusion, to the innermost layers to have its systemic action [5][12]. Coated microneedles are solid MNs made of inert material and coated with a formulation containing the drug to be administered [5][13]. After skin perforation, this lining is retained in the

Ethosomal (−)-epigallocatechin-3-gallate as a novel approach to enhance antioxidant, anti-collagenase and anti-elastase effects

• Çiğdem Yücel,
• Gökçe Şeker Karatoprak,
• Sena Yalçıntaş and
• Tuğba Eren Böncü

Beilstein J. Nanotechnol. 2022, 13, 491–502, doi:10.3762/bjnano.13.41

• many drugs. The stratum corneum in the epidermis, which is the top layer of the skin consisting of three layers, acts as an important barrier against penetration into the skin [9][16]. To overcome penetration limitations, various techniques such as penetration enhancers, phonophoresis, electroporation

• high amounts of ethanol that can carry both hydrophilic and lipophilic drug molecules. They are also highly deformable and reach deep skin layers [18][19]. ETHs are similar to the lipid bilayer composition of cells in the epidermis, due to the presence of phospholipids in their structure, and thus

• synergistic effect of phospholipids and ethanol enables the ETHs and drug molecules to reach the deeper layers of the skin [19][22][23]. The skin penetration mechanism of drug-loaded ETHs is explained by both the ETH effect and the ethanol effect. While ethanol increases drug penetration by increasing the

Zinc oxide nanostructures for fluorescence and Raman signal enhancement: a review

• Ioana Marica,
• Fran Nekvapil,
• Maria Ștefan,
• Cosmin Farcău and
• Alexandra Falamaș

Beilstein J. Nanotechnol. 2022, 13, 472–490, doi:10.3762/bjnano.13.40

Investigation of electron-induced cross-linking of self-assembled monolayers by scanning tunneling microscopy

• Patrick Stohmann,
• Sascha Koch,
• Yang Yang,
• Christopher David Kaiser,
• Julian Ehrens,
• Jürgen Schnack,
• Niklas Biere,
• Dario Anselmetti,
• Armin Gölzhäuser and
• Xianghui Zhang

Beilstein J. Nanotechnol. 2022, 13, 462–471, doi:10.3762/bjnano.13.39

• collision, rotational or vibrational transitions, electron attachment, electronic excitation, and ionization [4][5]. Oriented molecular layers on surfaces are particularly well suited for such studies as surface analytical tools, such as scanning tunneling microscopy (STM), allow for detailed observations

Tubular glassy carbon microneedles with fullerene-like tips for biomedical applications

• Sharali Malik and
• George E. Kostakis

Beilstein J. Nanotechnol. 2022, 13, 455–461, doi:10.3762/bjnano.13.38

• interlayer spacing in glassy carbon corresponds to the nature of the intercalating species [26]. Here the “stress” arises from the constraints of the growing glassy carbon layers from the curved alumina gas-flow tube and the intercalating species, which are gaseous species, generated when methane undergoes

Tunable superconducting neurons for networks based on radial basis functions

• Andrey E. Schegolev,
• Nikolay V. Klenov,
• Sergey V. Bakurskiy,
• Igor I. Soloviev,
• Mikhail Yu. Kupriyanov,
• Maxim V. Tereshonok and
• Anatoli S. Sidorenko

Beilstein J. Nanotechnol. 2022, 13, 444–454, doi:10.3762/bjnano.13.37

• , ferromagnetic, and normal layers. Keywords: networks on radial basis functions; Josephson circuits; radial basis functions (RBFs); spintronics; superconducting electronics; superconducting neural network; Introduction For modern telecommunications, probabilistic identification of various sources in a

• the chip. In thin layers of superconductors used to create parts of a neuron, the kinetic inductance is relatively large compared to the geometric one [52]. This is important for us since one can change the kinetic inductance relatively simply by controlling the concentration of superconducting charge

• proximity effect. The typical spin valve [55][56][57] is a hybrid structure containing at least a pair of ferromagnetic (FM) layers with different coercive forces. Variations in the relative orientation of their magnetizations change the spatial distribution of the superconducting order parameter. In the

The role of sulfonate groups and hydrogen bonding in the proton conductivity of two coordination networks

• Ali Javed,
• Felix Steinke,
• Stephan Wöhlbrandt,
• Hana Bunzen,
• Norbert Stock and
• Michael Tiemann

Beilstein J. Nanotechnol. 2022, 13, 437–443, doi:10.3762/bjnano.13.36

• ions, resulting in the formation of layers. This way, each phosphonate group is coordinating with two oxygen atoms, while the third one is protonated. The –C6H4-SO3 group points into the interlayer space. A network of hydrogen bonds between the sulfonate residues and coordinated water molecules as well

• as crystal water interconnect the layers into a three-dimensional network consisting of interlocked layers. In contrast, in the structure of [Pb2(HL)]·H2O, each sulfonate group is coordinating to several Pb2+ ions. A 2D inorganic building unit is observed and the coordination of the sulfonate groups

• maximum in the region from 103 to 104 Hz remains. The phase angle for the Pb-MOF sample shows only one maximum (at ca. 102 Hz) both before and after activation. We conclude that the second conductance mode in the non-activated Mg-CP material may be caused by interparticle water adsorbate layers that are

A chemiresistive sensor array based on polyaniline nanocomposites and machine learning classification

• Jiri Kroutil,
• Alexandr Laposa,
• Ali Ahmad,
• Jan Voves,
• Vojtech Povolny,
• Ladislav Klimsa,
• Marina Davydova and
• Miroslav Husak

Beilstein J. Nanotechnol. 2022, 13, 411–423, doi:10.3762/bjnano.13.34

• composed by seven different conductive sensors with composite sensing layers are measured and analyzed using machine learning. Statistical tools, such as principal component analysis and linear discriminant analysis, are used as dimensionality reduction methods. Five different classification methods

• (carbon nanotubes (CNT), SnO2, TiO2) materials in a gas sensors based on nanocomposite layers with good sensitivity, temperature stability, reversibility, which was operating at room temperature. Herein, we extended our study by applying other nanocomposite sensing layers, namely PANI/ZnO, PANI/WO3

• (nanopowder), PANI/WO3 (nanotubes), PANI/In2O3, PANI/C60 (fullerene), PANI/nanocrystalline diamond (NCD), and PANI/BaTiO3, deposited on a flexible sensor array platform with a new design. Seven different nanocomposite sensing layers deposited on the array were exposed to six different gases (ammonia, carbon

Electrostatic pull-in application in flexible devices: A review

• Teng Cai,
• Yuming Fang,
• Yingli Fang,
• Ruozhou Li,
• Ying Yu and
• Mingyang Huang

Beilstein J. Nanotechnol. 2022, 13, 390–403, doi:10.3762/bjnano.13.32

• common electrode materials are GR-Au and GR-GR. By adjusting the size of the graphene sheets, the number of layers and the gap, different pull-in voltages can be obtained. GR-Au: A typical GR-Au structure is shown in Figure 3a. As the structure requires a sacrificial layer to keep GR suspended and avoid

• , the gap was 170 nm, and the pull-in voltage was about 2 V. In 2016, Sun et al. [6] prepared a graphene cantilever switch with a thickness of about 10 layers, as shown in Figure 3a. The graphene sheet has an area of 1 µm × 2 µm, a gap of 1401 nm, and a critical voltage of 3.8 V. In addition, Liu et al

• , Huynh Van et al. [5] prepared a three-terminal fully flexible graphene switch for the first time, as shown in Figure 4. The switch is made of fully flexible materials. The three electrodes are all made of 1–2 layers of graphene, and the insulating medium layer is made of h-BN. The pull-in voltage at

Micro- and nanotechnology in biomedical engineering for cartilage tissue regeneration in osteoarthritis

• Zahra Nabizadeh,
• Mahmoud Nasrollahzadeh,
• Hamed Daemi,
• Mohamadreza Baghaban Eslaminejad,
• Ali Akbar Shabani,
• Mehdi Dadashpour,
• Majid Mirmohammadkhani and
• Davood Nasrabadi

Beilstein J. Nanotechnol. 2022, 13, 363–389, doi:10.3762/bjnano.13.31

• supports deeper layers from shear stresses [5]. The middle or transitional zone constitutes the thickest portion of articular cartilage (40–60%) and has fewer chondrocytes with a more rounded morphology [6]. In this layer, the collagen fibrils are arranged randomly and obliquely and the cells synthesize

• and vertical to the articular surface. Meanwhile, this zone provides the greatest resistance to compressive forces [6]. The calcified cartilage zone, which is presumed to be an interface layer between the upper cartilage layers and the rigid subchondral bone, contains chondrocytes, which usually

• inexpensive and abundant inorganic compound, which can be obtained from mines. Aluminosilicate layers can be rolled into a hollow cylinder structure to form tube structures less than 100 nm in diameter. Halloysite is a biocompatible nanomaterial, which does not need to be functionalized and can be a potent

Alcohol-perturbed self-assembly of the tobacco mosaic virus coat protein

• Ismael Abu-Baker and
• Amy Szuchmacher Blum

Beilstein J. Nanotechnol. 2022, 13, 355–362, doi:10.3762/bjnano.13.30

• between in TEM. The bilayer disk has been reported in two different polymorphs: a polar disk with both layers in the same orientation or a bipolar disk with the two layers related by C2 symmetry [18][19][20]. Under basic conditions and at high ionic strength, a four-layer disk aggregate is observed [21

• presence of different alcohol additives. (A) 5.0 mol % methanol; (B) 10.0 mol % methanol; (C) 3.5 mol % isopropyl alcohol. Orange arrows indicate long rod species. PyMOL [47] schematic showing (A) one face of the disk and (B) the side view of two layers of the disk. Hydrophobic residues are coloured in red

Selected properties of Al_xZn_yO thin films prepared by reactive pulsed magnetron sputtering using a two-element Zn/Al target

• Witold Posadowski,
• Artur Wiatrowski,
• Jarosław Domaradzki and
• Michał Mazur

Beilstein J. Nanotechnol. 2022, 13, 344–354, doi:10.3762/bjnano.13.29

• an order of magnitude greater than the minimum resistance of the layers deposited at the front of the substrate. In our opinion, film deposition on the back substrate surface was possible because the sputtered particles reached the back substrate side from collisions. They condensed on the substrate

Controllable two- and three-state magnetization switching in single-layer epitaxial Pd_1−xFe_x films and an epitaxial Pd_0.92Fe_0.08/Ag/Pd_0.96Fe_0.04 heterostructure

• Igor V. Yanilkin,
• Amir I. Gumarov,
• Gulnaz F. Gizzatullina,
• Roman V. Yusupov and
• Lenar R. Tagirov

Beilstein J. Nanotechnol. 2022, 13, 334–343, doi:10.3762/bjnano.13.28

• the film. In a wide range of the appled field directions, the magnetization reversal proceeds in two steps via the intermediate easy axis. An epitaxial heterostructure of two magnetically separated ferromagnetic layers, Pd0.92Fe0.08/Ag/Pd0.96Fe0.04, was synthesized and studied with dc magnetometry

• . Its magnetic configuration diagram has been constructed and the conditions have been determined for a controllable switching between stable parallel, orthogonal, and antiparallel arrangements of magnetic moments of the layers. Keywords: anisotropic magnetoresistance; magnetization reversal; Pd–Fe

• ], stable parallel and antiparallel configurations of magnetic moments were obtained. However, the maximum amplitude of the triplet pairing component in the PdFe1/N/PdFe2 bilayer structure is achieved near the orthogonal magnetic configuration of the ferromagnetic layers PdFe1 and PdFe2 [6]. Therefore, it

Interfacial nanoarchitectonics for ZIF-8 membranes with enhanced gas separation

• Season S. Chen,
• Zhen-Jie Yang,
• Chia-Hao Chang,
• Hoong-Uei Koh,
• Sameerah I. Al-Saeedi,
• Kuo-Lun Tung and
• Kevin C.-W. Wu

Beilstein J. Nanotechnol. 2022, 13, 313–324, doi:10.3762/bjnano.13.26

• ., strong acids or bases or organic solvents) compared to polymer substrates. The particle size of α-Al2O3 on dense top layers of these disks is around 200 nm (information from Fraunhofer IKTS, Germany). The porosity of the disks was measured as 41.58% by mercury porosimeter measurements. The XRD patterns

Investigation of a memory effect in a Au/(Ti–Cu)Ox-gradient thin film/TiAlV structure

• Damian Wojcieszak,
• Jarosław Domaradzki,
• Michał Mazur,
• Tomasz Kotwica and
• Danuta Kaczmarek

Beilstein J. Nanotechnol. 2022, 13, 265–273, doi:10.3762/bjnano.13.21

• a much wider (several hundred nanometers) semiconducting (e.g., doped or nonstoichiometric oxide) layer. Materials used either for insulating or semiconducting layers include HfO2 [3][15][16][17][18], ZnO [19][20], CuO [21][22][23][24][25][26][27], ZrO2 [12], Ta2O5 [28][29], and NiO [3][30][31][32

• ]. The most commonly used material in resistive switching devices is TiO2−x [33][34][35][36][37][38]. In addition to the oxide layers, the material used for metal electrodes plays another crucial role in the resistive switching mechanism. Usually, materials such as Au, Ag, Ni, Ti, W, TiN, or ITO are used

• . Therefore, to increase the sputtering flux of titanium species, two Ti and one Cu targets were sputtered in the so-called simultaneous mode. The magnetrons were arranged in a confocal configuration. To obtain a gradient distribution of elements as a function of the thickness of the deposited layers

Photothermal ablation of murine melanomas by Fe₃O₄ nanoparticle clusters

• Xue Wang,
• Lili Xuan and
• Ying Pan

Beilstein J. Nanotechnol. 2022, 13, 255–264, doi:10.3762/bjnano.13.20

• and lower hyperthermia efficiency [11]. Indeed, other researchers find that the temperature increase by magnetic hyperthermia is much lower than that of NIR-induced heating, presumably due to the coating layers needed for biological dispersion [12]. Yu et al. first discovered strong photothermal

Relationship between corrosion and nanoscale friction on a metallic glass

• Haoran Ma and
• Roland Bennewitz

Beilstein J. Nanotechnol. 2022, 13, 236–244, doi:10.3762/bjnano.13.18

• surface dissolution at the interface of the two layers. The findings contribute to the understanding of mechanical contacts with metallic glasses under corrosive conditions by exploring the interrelation of microscopic corrosion mechanisms and nanoscale friction. Keywords: atomic force microscopy (AFM

• solution and corrosion products on the surfaces reduced the friction coefficient [16][17]. The native oxide layers grown in the air were found to strengthen the friction coefficient and the wear resistance of MGs at the nanoscale [18][19]. The thermal oxidation caused a higher contribution of shearing and

• of the friction coefficient and the adhesion force on immersion time for inner and outer layers. The friction coefficient is calculated as the slope of a linear fit to the friction force versus normal load data (Figure 4). The adhesion force of the inner layer versus the AFM tip is determined as the

Theoretical understanding of electronic and mechanical properties of 1T′ transition metal dichalcogenide crystals

• Seyedeh Alieh Kazemi,
• Sadegh Imani Yengejeh,
• Vei Wang,
• William Wen and
• Yun Wang

Beilstein J. Nanotechnol. 2022, 13, 160–171, doi:10.3762/bjnano.13.11

• from catalysis to energy storage and electronic devices [1][2][3][4][5][6]. Generally, each TMD layer can be described as a sandwich type of structure (X–TM–X), where TM and X are transition metal cations (e.g., Mo and W) and chalcogen anions (e.g., S and Se). Individual layers are bound via

• mechanical properties using the axial loading and transverse loading models, respectively. The Young’s modulus Y, Poisson’s ratio ν and the microhardness parameter H can be obtained as: To investigate the impact of the bonding strength between atoms and layers of TMDs on their mechanical properties, the

• . Eint was calculated using the following equation: where Ebulk and Emono are the energies of the bulk and monolayer of TMDs, respectively. N is the number of the layers in each unit cell. To understand the bonding strength between TM and X atoms as well as its impact on the cohesive energy of the TMDs

A comprehensive review on electrospun nanohybrid membranes for wastewater treatment

• Senuri Kumarage,
• Imalka Munaweera and
• Nilwala Kottegoda

Beilstein J. Nanotechnol. 2022, 13, 137–159, doi:10.3762/bjnano.13.10

A photonic crystal material for the online detection of nonpolar hydrocarbon vapors

• Evgenii S. Bolshakov,
• Aleksander V. Ivanov,
• Andrei A. Kozlov,
• Anton S. Aksenov,
• Elena V. Isanbaeva,
• Sergei E. Kushnir,
• Aleksei D. Yapryntsev,
• Aleksander E. Baranchikov and
• Yury A. Zolotov

Beilstein J. Nanotechnol. 2022, 13, 127–136, doi:10.3762/bjnano.13.9

• hold this array, preventing it from moving apart due to the swelling of the polydimethylsiloxane layer, whereas when exposed to the test alkanes, this does not happen so quickly, and the shift of the lower layers is delayed, resulting in broadening of the photonic bandgap and a less pronounced color

Bacterial safety study of the production process of hemoglobin-based oxygen carriers

• Axel Steffen,
• Yu Xiong,
• Radostina Georgieva,
• Ulrich Kalus and
• Hans Bäumler

Beilstein J. Nanotechnol. 2022, 13, 114–126, doi:10.3762/bjnano.13.8

• inhibit DNA synthesis in bacteria, and similar effects are also seen on RNA and protein syntheses [44][45]. In addition, glutaraldehyde particularly acts on the outer layers of E. coli and cross-links lipoproteins and proteins there as well. This fixation of bacteria prevents the bacterial cells from

Tin dioxide nanomaterial-based photocatalysts for nitrogen oxide oxidation: a review

• Viet Van Pham,
• Hong-Huy Tran,
• Thao Kim Truong and
• Thi Minh Cao

Beilstein J. Nanotechnol. 2022, 13, 96–113, doi:10.3762/bjnano.13.7

• cell of rutile SnO2, a Sn4+ ion is bonded to six oxygen ions, and every oxygen atom is coordinated by three Sn4+ ions, forming a (6, 3) coordination structure [44]. When SnO2 materials are prepared as thin films with two to eight layers the bandgap is larger than that of bulk SnO2 and decreases with

Nanoscale friction and wear of a polymer coated with graphene

• Robin Vacher and
• Astrid S. de Wijn

Beilstein J. Nanotechnol. 2022, 13, 63–73, doi:10.3762/bjnano.13.4

• layers of graphene oxide and polyethylenimine. The authors showed that a transfer film of graphene on the polymer leads to lower friction. While to our knowledge there have been no numerical studies of friction on graphene-coated polymers, the graphene–polymer interface has been studied. Rissanou et al

• polymer near the surface is affected by the graphene layer. In the case of the flat graphene sheet, the particles of the polymer align in layers parallel to the surface, as can be seen in Figure 4b. In Figure 4b, the red flat region corresponds to a depth at which there is a high density of polymers. A

• graphene sheet is not just protecting the polymer from the tip, but also constraining the chains. Our work thus shows that it is the interaction between graphene and polymer that plays a crucial role in the friction and wear. The graphene layers we have used, both flat and crumpled, are constrained to

Sputtering onto liquids: a critical review

• Anastasiya Sergievskaya,
• Adrien Chauvin and
• Stephanos Konstantinidis

Beilstein J. Nanotechnol. 2022, 13, 10–53, doi:10.3762/bjnano.13.2

Topographic signatures and manipulations of Fe atoms, CO molecules and NaCl islands on superconducting Pb(111)

• Carl Drechsel,
• Philipp D’Astolfo,
• Jung-Ching Liu,
• Thilo Glatzel,
• Rémy Pawlak and
• Ernst Meyer

Beilstein J. Nanotechnol. 2022, 13, 1–9, doi:10.3762/bjnano.13.1

• ]. In this work, we report on the topographic features of adsorbed CO molecules, NaCl layers and Fe adatoms on a superconducting Pb(111) surface, investigated with STM at 4.8 K. We show that CO molecules on Pb(111) are hardly visible in STM images due to their high diffusion induced by the tip even at