KASCADE-Grande is an extensive air-shower experiment located at Forschungszentrum Karlsruhe, Germany. Main parts of the experiment are the Grande array spread over an area of
700
×
700
m
2
, the ...original KASCADE array covering
200
×
200
m
2
with unshielded and shielded detectors, and additional muon tracking devices. This multi-detector system allows to investigate the energy spectrum, composition, and anisotropies of cosmic rays in the energy range up to 1 EeV. LOPES is co-located at the same site to measure radio pulses from extensive air showers in coincidence with KASCADE-Grande. It consists of 30 digital antennas operated in different geometrical configurations. Read out is performed at high bandwidths and rate data processing with the aim to calibrate the emitted signal in the primary energy range of
10
16
−
10
18
eV
by making use of reconstructed air-shower observables of KASCADE-Grande. An overview on the performance of both experiments will be given and recent analysis results be reported.
Nanotechnology is showing promise in many medical applications such as drug delivery and hyperthermia. Nanoparticles administered to the respiratory tract cause local reactions and cross the ...blood–air barrier, thereby providing a means for easy systemic administration but also a potential source of toxicity. Little is known about how these effects are influenced by preexisting airway diseases such as asthma. Here, BALB/c mice are treated according to the ovalbumin (OVA) asthma protocol to promote allergic airway inflammation. Dispersions of polyethylene‐glycol‐coated (PEGylated) and citrate/tannic‐acid‐coated (citrated) 5 nm gold nanoparticles are applied intranasally to asthma and control groups, and (i) airway resistance and (ii) local tissue effects are measured as primary endpoints. Further, nanoparticle uptake into extrapulmonary organs is quantified by inductively coupled plasma mass spectrometry. The asthmatic precondition increases nanoparticle uptake. Moreover, systemic uptake is higher for PEGylated gold nanoparticles compared to citrated nanoparticles. Nanoparticles inhibit both inflammatory infiltrates and airway hyperreactivity, especially citrated gold nanoparticles. Although the antiinflammatory effects of gold nanoparticles might be of therapeutic benefit, systemic uptake and consequent adverse effects must be considered when designing and testing nanoparticle‐based asthma therapies.
When nanoparticles are applied via the respiratory tract, uptake to extrapulmonary organs is higher for PEGylated than citrated 5 nm gold nanoparticles. Asthma‐like inflammation of the respiratory system induces greater uptake of both nanoparticle types. The nanoparticles have an antiinflammatory effect in the airways, which is stronger for the citrated gold nanoparticles.
Various Nano Building Blocks (NBBs) such as polyhedral silsesquioxanes (POSS), functionalized metal oxide particles and transition metal oxoclusters have been already developed and used to improve ...thermal and mechanical properties of organic polymers. The NBBs ideal for the preparation of hybrid materials and nanocomposites are monodispersed, well-defined objects capped with polymerisable functions suitable for copolymerisation with organic monomers.
In this study zirconium oxoclusters (ZrNBB) were obtained as a crystalline precipitate by reaction between zirconium propoxide and vinylacetic acid. They were post-functionalised by copolymerisation with vinyl trimethoxysilane in different molar ratios. The hybrid samples were prepared both with the organosilane pre-hydrolysis step and without adding water. Hybrid materials were obtained through the radical polymerization process by adding benzoyl peroxide (BPO). Silane pre-hydrolysis prevents bulk samples from being obtained.
The polymerization process was studied using differential scanning calorimetry (DSC), and the shear storage modulus (G′) and loss modulus (G″) of hybrid polymers were investigated by dynamic mechanical spectroscopy (DMS). Multinuclear liquid- and solid-state NMR analyses and Fourier transform infrared (FTIR) spectroscopy were used to characterize the reagents and hybrid materials, and to study the influence of the synthesis conditions on condensation and polymerization.
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In this study surface-functionalized zirconium oxoclusters (ZrNBB), formed by reaction between vinylacetic acid and zirconium propoxide, were chemically modified through condensation with siloxane ...groups, so that the core integrity of ZrNBB was preserved. The direct coupling between zirconium oxo-clusters and siloxane moiety was performed by co-polymerisation with vinyl trimethoxysilane (VTMS) with Zr:Si molar ratio 1:2 in air at room temperature and benzoyl peroxide (BPO) was used as an initiator to start radical polymerization. The polymerisation was studied by differential scanning calorimetry (DSC) and Fourier Transform Infra Red (FTIR) spectroscopy.
29
Si and
13
C liquid and solid state NMR analyses were performed in order to study the microstructure of the hybrid material and the role of the clusters in polymerization and condensation. Beyond this, shear storage modulus (G′) and loss modulus (G′′), were investigated by dynamical mechanical spectroscopy (DMS). The results indicated a great stability at high temperature without any viscous flow during glass transition.
The synthesis of a novel proton transfer compound (2-apyH)(pdtcH),
L, derived from pyridine-2,6-bis(monothiocarboxylic) acid, (pdtcH
2), is reported. This compound was prepared from the reaction ...between pdtcH
2, and 2-aminopyridine, (2-apy), in water as solvent. The characterization was performed using
1H and
13C solution NMR and single crystal X-ray diffraction analysis. Crystal structure analysis reveals that intra- and intermolecular proton transfer from the diacid pdtcH
2 to the base 2-apy results in the formation of a supramolecular network, which is self-assembled
via non-covalent interactions. The monocationic (2-apyH)
+ and monoanionic (pdtcH)
− building blocks are connected through H-bonding, π–π interactions and ion-pairing simultaneously as shown in the X-ray crystal structure. The monoanionic fragments are located almost parallel to each other and the cationic species have also situations nearly parallel to each other, positioning almost perpendicular to anions. The aqueous solution studies were accomplished by spectrophotometric and potentiometric pH titrations. The most abundant proton transfer species present at pH
<
6 is (2-apyH)(pdtcH), in support of association between (2-apyH)
+ and (pdtcH)
− in
L, being similar to that observed by NMR spectroscopy and X-ray crystal structure analysis.
Reaction of (κ
2-P,N)–Me
2N(CH
2)
3PPh
2PtMe
2 (P∩N)PtMe
2 with HSiR
3 (triethylsilane or diphenylmethylsilane) results in the formation of MeSiR
3 and the methyl silyl complexes (P∩N)Pt(Me)SiR
3. In ...the early stages of the reaction, the hydrido complex (P∩N)Pt(Me)H is additionally observed. In the reaction of HSiMePh
2, the rearranged complex (P∩N)Pt(Ph)SiMe
2Ph is also formed. The reactivity of the complexes (P∩N)PtMe
2 is influenced by the kind of chelating P∩N ligand and appears to depend on how easily the amino group is de-coordinated.
Reaction of (κ
2-P,N)–Me
2N(CH
2)
3PPh
2PtMe
2 (P∩N)PtMe
2 with HSiEt
3 or HSiMePh
2 results in the formation of MeSiR
3 and the methyl silyl complexes (P∩N)Pt(Me)SiR
3 via the hydrido complex (P∩N)Pt(Me)H.
Well defined amphiphilic block copolymers containing a polydimethyl siloxane (PDMS) and a poly(ethylene oxide) block (PEO) were synthesized by ring opening polymerization of ...hexamethylcyclotrisiloxane, followed by chain extension with a PEO block of a defined length. These amphiphilic molecules were used as templates in a solvent-evaporation driven synthesis approach to self-assembled mesostructured silica films. Thin films and powders were prepared, and the resulting material was characterized by X-ray diffraction, transmission electron microscopy, and 29Si and 13C solid state NMR. The behavior of the PEO-b-PDMS block copolymer during heat treatment up to 600°C was followed in detail by solid state NMR.
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