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Search for "SEM" in Full Text gives 107 result(s) in Beilstein Journal of Organic Chemistry.
Thermal and oxidative stability of the Ocimum basilicum L. essential oil/β-cyclodextrin supramolecular system
Beilstein J. Org. Chem. 2014, 10, 2809–2820, doi:10.3762/bjoc.10.298
- microscopy, SEM (Inspect S, voltage of 25 kV, magnification of 3000–12000×, focus of 10–14.1 mm; see Supporting Information File 1). Rhombohedral prisms with dimensions up to ten micrometers for O. basilicum L. essential oil/β-CD complex were obtained. The relative concentration of the main compounds of the
Detonation nanodiamonds biofunctionalization and immobilization to titanium alloy surfaces as first steps towards medical application
Beilstein J. Org. Chem. 2014, 10, 2765–2773, doi:10.3762/bjoc.10.293
- -PEA. Immobilization of DND Scanning electron microscopy (SEM) was used to characterize the surface morphology of titanium samples coated with previously functionalized nanodiamonds. DND before and after functionalization were used to evaluate the improvement on the interaction of DND with the titanium
- Ti6Al7Nb followed by anodic polarization. The titanium based alloy substrate at the bottom is covered on top with an anodic oxide layer (thickness approx. 120 nm). An immobilization of 6 on titanium anodic oxide layer can clearly be seen, which was already indicated in the SEM images in Figure 4 for 6. At
- by hydrogen bridging and electrostatic affinity to positively charged amino groups. SEM results Figure 4 from unfunctionalized DND demonstrate a better interaction with the titanium oxide layer than carboxylated DND with O-PEA 3 and silanized DND 5. This may be explained by the presence of several
Preparation and evaluation of cyclodextrin polypseudorotaxane with PEGylated liposome as a sustained release drug carrier
Beilstein J. Org. Chem. 2014, 10, 2756–2764, doi:10.3762/bjoc.10.292
- obvious difference was not observed. These results suggest that the presence of DOX in PEG-LP scarcely alters the physicochemical properties of the PPRX. Additional studies by means of SEM or TEM may permit a more precise analysis and might confirm whether the LP structure is retained. Structure of CD
Encapsulation of biocides by cyclodextrins: toward synergistic effects against pathogens
Beilstein J. Org. Chem. 2014, 10, 2603–2622, doi:10.3762/bjoc.10.273
- /polyacrylonitrile/copper nanorods composite fibers by adsorption and reduction. The composite fibers were fully characterized by FTIR, SEM, TEM, energy dispersive spectroscopy and X-ray photoelectron spectroscopy. The results indicated that the copper nanorods were not only successfully synthesized on the surface
Improving the reactivity of phenylacetylene macrocycles toward topochemical polymerization by side chains modification
Beilstein J. Org. Chem. 2014, 10, 1613–1619, doi:10.3762/bjoc.10.167
- the xerogel state to form polydiacetylenes (PDAs), leading to a significant enhancement of the polymerization yields. The organogels and the PDAs were characterized using Raman spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). Keywords: carbon nanomaterials; organogels
- heating the gel from 223 to 298 K, an endotherm was observed in both cases, which is closely related to the melting point of free cyclohexane [39]. To explore the morphology of the structures created during the gel formation, scanning electron microscopy (SEM) was performed on PAM2 only since PAM3 did not
- present any gelation properties. For SEM analysis, a gel sample was allowed to dry at room temperature on a metallic substrate to form a xerogel. Then, gold was sputtered on the sample prior to imaging. SEM images of PAM2 are shown in Figure 2. As previously observed with PAM1 and other phenylacetylene
Charge-transfer interaction mediated organogels from 18β-glycyrrhetinic acid appended pyrene
Beilstein J. Org. Chem. 2013, 9, 2877–2885, doi:10.3762/bjoc.9.324
- in the formation of CT gels is demonstrated through the formation of gels in a variety of solvents. Thermal stability, stoichiometry, scanning electron microscopy (SEM), optical micrographs, and circular dichroism (CD) are performed on these CT gels to investigate their thermal and assembly
- acceptor in these CT gels. Microscopic study Generally, it is believed that the gelation system is the result of a gelator network formed during the cooling or shaking process [52]. The morphology of the xerogels obtained from CT gels was investigated by scanning electron microscopy (SEM) in order to
- -component CT interaction induced an organogel formation based on 18β-glycyrrhetinic acid–pyrene conjugate 3 and 2,4,7-trinitrofluorenone (TNF, 4). Their thermal and assembly properties were studied by thermal stability, stoichiometry, scanning electron microscopy (SEM), optical micrographs, and circular
Total synthesis of (−)-epimyrtine by a gold-catalyzed hydroamination approach
Beilstein J. Org. Chem. 2013, 9, 2042–2047, doi:10.3762/bjoc.9.242
- , 168.1387. Previously reported approach from β-aminoynones for the synthesis of pyridones. Retrosynthetic analysis of (−)-epimyrtine. Synthesis of (−)-epimyrtine. Supporting Information Supporting Information File 542: Spectra of new compounds. Acknowledgements We thank the Program Ciências Sem Fronteiras
Self-assembly of 2,3-dihydroxycholestane steroids into supramolecular organogels as a soft template for the in-situ generation of silicate nanomaterials
Beilstein J. Org. Chem. 2013, 9, 1826–1836, doi:10.3762/bjoc.9.213
- LMOG 1 in the liquid-like solution phase trapped within the SAFIN (see Supporting Information File 1 for IR spectra) [17]. The microscopic morphology of the xerogel of 1 from DCM, n-hexane and dioxane was analyzed by SEM. The images showed an entangled fibrillar network for all solvents. Particularly
- bulk due to the collapsed fibrillar network. For n-hexane and dioxane simple straight entangled fibers were observed with a minimum width of 20 nm. In all cases fibers with lengths of up to several micrometers were clearly visible. SEM images of the xerogel from dioxane showed a tighter SAFIN compared
- –gel polymerization experiments were performed with dioxane and dichloromethane gels containing 16.6% of TEOS with benzylamine as a catalyst. The morphology of the nanostructured silica obtained was analyzed by SEM microscopy (Figure 7). A first polymerization attempt using 3 μL of catalyst and 15 μL
Synthesis and biological activities of the respiratory chain inhibitor aurachin D and new ring versus chain analogues
Beilstein J. Org. Chem. 2013, 9, 1551–1558, doi:10.3762/bjoc.9.176
- (untreated cells) was set to 100% and the value of FCCP-treated cells (positive control) was set to 0%. Bars represent the mean ±SEM of all cellular segments within a well. (B) Representative HCS images of U-2 OS cells that were treated with aurachin D (4) or the geranyl analogue 9. Cells were labeled with
Simple and rapid hydrogenation of p-nitrophenol with aqueous formic acid in catalytic flow reactors
Beilstein J. Org. Chem. 2013, 9, 1156–1163, doi:10.3762/bjoc.9.129
- stabilized against precipitation by complex formation with EDTA and NH3, which also controls the deposition rate of the individual metal by modifying the redox potential [33]. SEM and EDX analysis of the plated layer indicated the mixed distribution of Pd and Ag over the inner surface (Figure 1b). It has
- a Pd–Ag co-plated layer preferentially dissolved Ag, leaving pores behind. Figure 1c shows an SEM image of the porous Pd surface after removal of Ag, where numerous pores are observed. Direct determination of the porosity of the porous metal layer was difficult because it firmly adhered and resisted
- chemicals remaining inside the tube. The Pd–Ag mixed layer thickness was estimated as ca. 4.2 μm. Subsequent removal of Ag by passing 4 M HNO3 (840 mL) at 25 °C with a flow rate of 0.5 mL min−1 gave the porous Pd surface as observed by SEM imaging. The remaining amounts of Pd and Ag were 48.1 mg (94%) and
C–C Bond formation catalyzed by natural gelatin and collagen proteins
Beilstein J. Org. Chem. 2013, 9, 1111–1118, doi:10.3762/bjoc.9.123
- tin plate and shielded by Pt (40 mA during 30 s for FE-SEM; film thickness ≈5 nm). Typical procedure for gelatin-catalyzed Henry reaction Nitromethane (27 μL, 0.5 mmol) was added in one portion to a 4 mL screw cap vial containing 4-nitrobenzaldehyde (15.1 mg, 0.1 mmol), PSTA gelatin (2 mg) and DMSO
Use of 3-[18F]fluoropropanesulfonyl chloride as a prosthetic agent for the radiolabelling of amines: Investigation of precursor molecules, labelling conditions and enzymatic stability of the corresponding sulfonamides
Beilstein J. Org. Chem. 2013, 9, 1002–1011, doi:10.3762/bjoc.9.115
- with SEM values less than 10% of the mean values. Synthesis of radiofluorination precursors 3 and 4. Reagents and conditions: (a) KSCN, CH3OH, reflux; (b) TsCl, DIPEA, pyridine, CH2Cl2, rt (for 3) or NsCl, K(CH3)3SiO, THF, rt (for 4); (c) KSCN, CH3OH, reflux; (d) NaI, acetone, reflux; (e) Ph3P, I2
Design and synthesis of tag-free photoprobes for the identification of the molecular target for CCG-1423, a novel inhibitor of the Rho/MKL1/SRF signaling pathway
Beilstein J. Org. Chem. 2013, 9, 966–973, doi:10.3762/bjoc.9.111
- migration. The change in migration over 24 h was determined by the difference between the area of the wound after 24 h and the initial area of the wound. The percent inhibition was plotted by normalizing the compound-treated cells to the DMSO control. Results are expressed as the mean (±SEM) of triplicate
A peptidic hydrogel that may behave as a “Trojan Horse”
Beilstein J. Org. Chem. 2013, 9, 417–424, doi:10.3762/bjoc.9.44
- 10.3762/bjoc.9.44 Abstract A physical hydrogel prepared with the low-molecular-weight hydrogelator (LMWHG) CH2(C3H6CO-L-Phe-D-Oxd-OH)2 and water/ethanol mixture was applied as a potential “Trojan Horse” carrier into cells. By SEM and XRD analysis we could demonstrate that a fibrous structure is present in
- , were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Hydrogel 1 is a strong and thermoreversible gel (Figure 1a) with its melting point at 45 °C. The XRD pattern from the hydrogel 1, collected at 100 K, is characterized by the presence of diffraction rings at low angle
- assembly of molecules 1 to form the fibrous structures. Moreover, XRD data and SEM observation show that in the xerogel the fibers align preferentially parallel to the film surface and may suggest that in the fiber the molecules are organized in layers (0.54 nm thick) and that they have their long axis
Self-assembled organic–inorganic magnetic hybrid adsorbent ferrite based on cyclodextrin nanoparticles
Beilstein J. Org. Chem. 2012, 8, 1867–1876, doi:10.3762/bjoc.8.215
- thermal analysis (TG/DTA), and by their magnetic behavior in aqueous suspension (see Supporting Information File 1). Fe-Ni/Zn and Fe-Ni/Zn/βCD nanoparticles morphologies were investigated in the solid state by scanning electronic microscopy (SEM), transmission electronic microscopy (TEM), and atomic force
- different aggregation levels, these materials were investigated in the solid state by SEM, TEM and AFM and also in aqueous suspension by using DLS. AFM images of Fe-Ni/Zn and Fe-Ni/Zn/βCD are presented in Figure 1. Based on these images, nanoparticles below 100 nm were verified for these materials. Looking
- ferrite synthesis, preventing the particles growing during the ferrite synthesis (nucleation process). In order to gain insight into the microstructure of these assembled materials, SEM and TEM were also carried out. TEM images of the magnetic materials, demonstrating their structure from the nanoscale
trans-2-(2,5-Dimethoxy-4-iodophenyl)cyclopropylamine and trans-2-(2,5-dimethoxy-4-bromophenyl)cyclopropylamine as potent agonists for the 5-HT2 receptor family
Beilstein J. Org. Chem. 2012, 8, 1705–1709, doi:10.3762/bjoc.8.194
- . Affinity values (Ki in nM) at human 5-HT2A and 5-HT2C receptors. All values represent mean and SEM from at least three independent experiments. Potency and percent max values for calcium release at 5-HT2A and 5-HT2C receptors. All values represent mean and SEM from at least three independent experiments
Control over molecular motion using the cis–trans photoisomerization of the azo group
Beilstein J. Org. Chem. 2012, 8, 1071–1090, doi:10.3762/bjoc.8.119
- capable of holding other molecules. The isomerization process of azobenzene generates a molecular flapping and the molecules can be expelled outside in a photoinduced way. The morphology of the light-activated mesostructured silica nanoparticles (LAMs) is evaluated by scanning electron microscopy (SEM
Cyanoethylation of the glucans dextran and pullulan: Substitution pattern and formation of nanostructures and entrapment of magnetic nanoparticles
Beilstein J. Org. Chem. 2012, 8, 551–566, doi:10.3762/bjoc.8.63
- specific interaction between cyano groups and iron could be proven. The size distribution and morphology of the nanoparticles were analyzed by dynamic light scattering (DLS), scanning electron microscopy (SEM) and energy-filtered transmission electron microscopy (EF–TEM) with parallel electron energy loss
- electron microscopy (SEM) micrographs were recorded. Using SEM the morphology of polysaccharide particles is accessible. The parameters and results of the DLS and SEM measurements are summarized in Table 3. DLS measurements were in good agreement with the evaluation of the electron microscopy images
- . According to the micrographs, the morphology of the cyanoethyl nanoparticles can be considered as spherical. Representative SEM pictures of CEP-3 + Fe-np (Table 3, entry 2) are shown in Figure 10. The influence of different amounts of ferromagnetic nanoparticle dispersion was investigated (10–200 μL or
Scaling up of continuous-flow, microwave-assisted, organic reactions by varying the size of Pd-functionalized catalytic monoliths
Beilstein J. Org. Chem. 2011, 7, 1150–1157, doi:10.3762/bjoc.7.133
- sealed within the Teflon® tube to form a flow Pd-monolith reactor system. Sample characterization Scanning electron microscopy (SEM) images were obtained by means of a Cambridge S360 scanning electron microscope operated at 20 kV. Each sample was sputter coated with a thin layer of gold–platinum
- of the cylindrical monolith. The µm-scale pore size was determined from SEM measurements. Activity measurements The experimental setup is shown schematically in Supporting Information File 1, Figure S6. The 30 mm long Pd-monolith reactor with a diameter of either 3.2 mm (Pd-monolith-3.2) or 6.4 mm
- analyzed using GC–MS (Varian 2000) as described in literature [3][4]. SEM image of silica monolith. Reactivity of the Pd-monolith-3.2 and Pd-monolith-6.4 for the Suzuki–Miyaura reaction between bromobenzene (0.1 M) and phenylboronic acid (0.12 M): The relationship of product yield with contact time
Air-stable, recyclable, and time-efficient diphenylphosphinite cellulose-supported palladium nanoparticles as a catalyst for Suzuki–Miyaura reactions
Beilstein J. Org. Chem. 2011, 7, 378–385, doi:10.3762/bjoc.7.48
- in ethanol (Scheme 1). The as-prepared Cell–OPPh2–Pd0 catalyst was characterized by inductively coupled plasma-atomic emission spectrometry (ICP-AES), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analyses (TGA), scanning electron microscopy (SEM) and
- morphology of Cell–OPPh2–Pd0 and Cell–OPPh2 was studied by SEM and TEM. A clear change in morphology is observed after anchoring palladium onto the polymer support (Figure 3). The TEM image of the Cell–OPPh2–Pd0 catalyst shows that the average size of the nanopalladium particles is in the range of 4–15 nm
- inductively coupled plasma (ICP) spectroscopy. Scanning electron microscopy (SEM) was performed with a Philips XL 30ESEM instrument. Transmission electron microscopy (TEM) was performed with a Philips Tecnai instrument operating at 40–100 kV. The chemicals were obtained from commercial sources and used as
Protonation and deprotonation induced organo/hydrogelation: Bile acid derived gelators containing a basic side chain
Beilstein J. Org. Chem. 2011, 7, 304–309, doi:10.3762/bjoc.7.40
- . Keywords: bile acid derived amines; organogelator and hydrogelator; protonation and deprotonation induced gelation; SEM and POM; thermal stability; Introduction Low molecular mass organo- and hydrogelators (LMOG) have attracted considerable attention in recent years due to their tunable physical
- transition and this time the gel turned pink colour (Figure 3c, heating and cooling reformed the gel). (C) SEM and POM characterization of the gels The gels showed birefringent textures under a polarizing optical microscope [19]. The organogel showed spherulitic structures [20] (where the fibres originated
- from nucleation centres, Figure 4a) and a highly entangled fibrillar network (Figure 4b) at higher (1.25% w/v) and lower (0.25% w/v) concentrations of gelator, respectively. SEM images showed the presence of fine fibres (diameter <1μm) in the organogel (Figure 4c, Figure 4d). However, for the DMSO
Amphiphilic dendritic peptides: Synthesis and behavior as an organogelator and liquid crystal
Beilstein J. Org. Chem. 2011, 7, 198–203, doi:10.3762/bjoc.7.26
- dendritic polyaspartic acid were designed and synthesized. The organogel and liquid crystal properties of these amphiphilic dendritic peptides were fully studied by field-emission SEM, temperature dependent FT-IR, differential scanning calorimetry, polarization optical microscopy and X-ray diffraction
- . Compound G3 gelled in n-hexane, toluene, 1,4-dioxane, and ethanol but was soluble in dichloromethane. The microscopic structure of the gel was investigated by field-emission SEM (FE-SEM). Figure 1 shows representative FE-SEM images of the xerogel of G3 formed in n-hexane. These images clearly show that
- Advance (Bruker AXS Inc.) with Cu Kα1: 1.54051 Å. FT-IR spectra were recorded with a Varian 640-IR in the range of 400–4000 cm−1. SEM measurement was performed with XL30 field emission scanning electron microscope. G1: 2.67 g N-carbobenzyloxy-L-aspartic acid (10.0 mmol) was dissolved in 60 mL of DCM. 4.79
Hoveyda–Grubbs type metathesis catalyst immobilized on mesoporous molecular sieves MCM-41 and SBA-15
Beilstein J. Org. Chem. 2011, 7, 22–28, doi:10.3762/bjoc.7.4
- adsorption isotherms: surface area SBET = 972 and 934 m²/g, average pore diameter d = 3.8 and 6.9 nm and volume of pores V = 1.14 and 0.96 cm³/g. The particle size (by SEM) ranged from 1 to 3 μm for all supports used. Techniques UV–vis spectra of catalysts were recorded with a Perkin-Elmer Lambda 950
ROMP-Derived cyclooctene-based monolithic polymeric materials reinforced with inorganic nanoparticles for applications in tissue engineering
Beilstein J. Org. Chem. 2010, 6, 1199–1205, doi:10.3762/bjoc.6.137
- (SEM) images of the powders showed agglomerates of nanoparticles (~50–100 nm) and a rhombohedral calcite crystal structure was detected both by X-ray diffraction (XRD) and Raman measurements. Nano-sized platelets with a thickness <20 nm were formed in the synthesis of HAp and exhibited a calcium
- be biocompatible [7]. SEM images of the nanoparticle-reinforced monolithic materials revealed an increase of the pore sizes with increasing nanoparticle content. An increase of the pore size from 10–30 µm (for monoliths without any inorganic component) up to 25–70 µm was observed with the addition of
- spectra were recorded on a Bruker Vector 22 using ATR technology. Raman spectra were recorded on a Bruker RFS 100. Scanning electron microscopic (SEM) images were obtained on a Zeiss Ultra 55 field-emission (FEG) SEM device (Carl Zeiss SMT, Germany) at 0.6 keV for CaCO3 and HAp powders and 1.0 keV for the
Differences between β-Ala and Gly-Gly in the design of amino acids-based hydrogels
Beilstein J. Org. Chem. 2010, 6, 973–977, doi:10.3762/bjoc.6.109
- properties were related to hydrogen bonding, hydrophobic interactions and π-π stacking. Herein, β-Ala-His-EO2-Alk was fully characterised by FT-IR, NMR, SAXS and SEM and the gelation mechanism is discussed. It appears that the number of amide groups determines the self-assembling behaviour into 1D or 2D/3D
- method at the same concentration, and was higher than the sol-to-gel transition temperature of the 2% w/v sample. On drying, the fibres aggregate to form larger fibre bundles as shown in Figure 4. The morphology of the gel was observed by scanning electron microscopy (SEM, Figure 4). The micrographs show
- ). SEM micrographs of β-Ala-His-EO2-C14 hydrogels after drying. 2D/3D self assembling of β-Ala-His-EO2-C14. Acknowledgements We thank Salveco and region Lorraine for financial support, Mehdi Yemloul for his contribution to the NMR spectra and Dr. S. Funari and HASYLAB/DESY, Hamburg for the beamtime (A2
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