Preparation, Characterisation and Measurement of the in vitro Cytotoxicity of Mesoporous Silica Nanoparticles Loaded with Cytotoxic Pt(II) Oxadiazoline Complexes

Cytotoxic platinum compounds play a major role in the chemotherapy of a large number of human cancers. However, due to the severe side effects for the patient and other problems associated with their use, there is a need for the development of more efficient drugs and new methods for their selective delivery to the tumours. One way to achieve the latter could be in the use of nanoparticular carrier materials that can adsorb or chemically bind the drug. In the cell, the drug is supposed to be slowly released, either by physical desorption or by dissolution of the particle framework. Ideally, the cytotoxic properties of the platinum drug unfold only then, in the cancer cell and over a longer period of time due to the gradual release. In this paper, we report on our first steps in this direction. The binding properties of a series of cytotoxic Pt(II) oxadiazoline compounds to mesoporous silica particles has been studied by NMR and UV/vis spectroscopy. High loadings were achieved when the Pt(II) compound was relatively polar, and has been dissolved in a relatively unpolar solvent before the silica was added. Typically, 6-10 hours were required for complete equilibration, suggesting the adsorption did not only occur to the outer surface but also to the interior of the pores. The untreated and Pt(II) loaded particles were characterised by C,H,N combustion analysis, BET/BJH nitrogen sorption, electron microscopy (REM and TEM) and EDX. With the latter methods we were able to demonstrate the homogenous distribution of the Pt(II) compound on and in the silica particles, and no Pt(II) bulk precipitate had formed. The in vitro cytotoxicity in a human cancer cell line (HeLa) has been determined for one of the new platinum compounds adsorbed to mesoporous silica particles of different size, and compared with the corresponding compound in solution. The IC50 data are similar in all cases, suggesting that the release of the Pt(II) compound was relatively fast and possibly occurred before the particles reached the cells. Overall, the platinum drug is chemically stable on silica and retained its activity upon prolonged storage

Effects of RNA branching on the electrostatic stabilization of viruses

Many single-stranded (ss) RNA viruses self assemble from capsid protein subunits and the nucleic acid to form an infectious virion. It is believed that the electrostatic interactions between the negatively charged RNA and the positively charged viral capsid proteins drive the encapsidation, although there is growing evidence that the sequence of the viral RNA also plays a role in packaging. In particular the sequence will determine the possible secondary structures that the ssRNA will take in solution. In this work, we use a mean field theory to investigate how the secondary structure of the RNA combined with electrostatic interactions affects the efficiency of assembly and stability of the assembled virions. We show that the secondary structure of RNA may result in negative osmotic pressures while a linear polymer causes positive osmotic pressures for the same conditions. This may suggest that the branched structure makes the RNA more effectively packaged and the virion more stable

Dissolved black carbon in aquatic ecosystems

The incomplete combustion of organic molecules produces a chemically diverse suite of pyrogenic residues termed black carbon (BC). The significance of BC cycling on land has long been recognized, and the recognition of dissolved BC (DBC) as a major component of the aquatic carbon cycle is developing rapidly. As we seek a greater understanding of DBC cycling, our interpretation of environmental DBC concentrations and molecular composition should take into account both the formation conditions of charred residues, and the physico‐chemical transformation of DBC that occurs during transit within aquatic systems. We present the current state of knowledge concerning sources, processing, and sinks of DBC in inland, coastal/estuarine, and ocean waters. We feature studies and new methodologies which focus specifically on the aquatic cycling of DBC, explore the relationship between particulate and dissolved BC, and highlight research gaps which should be targeted to advance our current knowledge of DBC biogeochemistry

Prinz Eugen von Savoyen als Mäzen

Für den Autor ist der Diplomat und Feldherr Prinz Eugen von Savoyen, der zu seiner Zeit einer der größten Kunstsammler und Bauherren des Reiches war, auch herausragender Mäzen. Im Verlauf dieser Arbeit wird diese Behauptung dadurch untermauert, dass seine weit über das normale Ausmaß von Auftraggeber zu Auftragnehmer hinausgehende Beziehungen zu den einzelnen Künstlern dokumentiert werden.The author sees the diplomat and general Prince Eugen of Savoyen being on of the greatest collector of art and builder in the Holy Roman Empire as one of the most outstanding patron. In the course of his paper the author supports this thesis by documenting the close relationship between patron and the individual artist

Pengaruh Intellectual Capital Terhadap Kinerja Keuangan Dan Nilai Pasar Perusahaan

The objective of this study was to investigate influence of firm’sintellectual capital on their financial performance and market value. The objects of this paper are manufacturing industries listed at the Indonesian Stock Exchange period 2007 to 2008. By using 41 companies sample using purposive sampling method. This study used simple regression to examinethe influence intellectual capital (Value added intellectual capital (VAIC)) to financial performances and company market value. To examine the influence of three component of intellectual capital (capital employed efficiency(VACA), human capital efficiency (VAHU) and structural capital efficiency (STVA) to financial performances and company market value, this study uses multiple regression. The results showed that only VAHU has significant influence to company market value and only STVA has significant influenceto financial performance

Influence of wavy surfaces on coherent structures in a turbulent flow

We describe how outer flow turbulence phenomena depend on the interaction with the wall. We investigate coherent structures in turbulent flows over different wavy surfaces and specify the influence of the different surface geometries on the coherent structures. The most important contribution to the turbulent momentum transport is attributed to these structures, therefore this flow configuration is of large engineering interest. In order to achieve a homogeneous and inhomogeneous reference flow situation two different types of surface geometries are considered: (1) three sinusoidal bottom wall profiles with different amplitude-to-wavelength ratios of α =2a/Λ=0.2 (Λ = 30mm), α=0.2 (Λ = 15mm), and α=0.1 (Λ =30mm); and (2) a profile consisting of two superimposed sinusoidal waves with α=0.1 (Λ =30mm). Measurements are carried out in a wide water channel facility (aspect ratio 12:1). Digital particle image velocimetry (PIV) is performed to examine the spatial variation of the streamwise, spanwise and wall-normal velocity components in three measurement planes. Measurements are performed at a Reynolds number of 11,200, defined with the half channel height h and the bulk velocity U B. We apply the method of snapshots and perform a proper orthogonal decomposition (POD) of the streamwise, spanwise, and wall-normal velocity components to extract the most dominant flow structures. The structure of the most dominant eigenmode is related to counter-rotating, streamwise-oriented vortices. A qualitative comparison of the eigenfunctions for different sinusoidal wall profiles shows similar structures and comparable characteristic spanwise scales Λ z =1.5H in the spanwise direction for each mode. The scale is observed to be slightly smaller for α=0.2 (Λ =15mm) and slightly larger for α=0.2 (Λ =30mm). This scaling for the flow over the basic wave geometries indicates that the size of the largest structures is neither directly linked to the solid wave amplitude, nor to the wavelength. The characteristic spanwise scale of the dominant eigenmode for the developed flow over the surface consisting of two superimposed waves reduces to 0.85H. However, a scale in the order of 1.3H is identified for the second mode. The eigenvalue spectra for the superimposed waves is much broader, more modes contribute to the energy-containing range. The turbulent flow with increased complexity of the bottom surface is characterized by an increased number of dominant large-scale structures with different spanwise scale

Scalar transport from a point source in flows over wavy walls

Simultaneous measurements of the velocity and concentration field in fully developed turbulent flows over a wavy wall are described. The concentration field originates from a low-momentum plume of a passive tracer. PLIF and digital particle image velocimetry are used to make spatially resolved measurements of the structure of the scalar distribution and the velocity. The measurements are performed at three different Reynolds numbers of Re b = 5,600, Re b = 11,200 and Re b = 22,400, respectively, based on the bulk velocity u b and the total channel height 2h. The velocity field and the scalar field are investigated in a water channel with an aspect ratio of 12:1, where the bottom wall of the test section consists of a train of sinusoidal waves. The wavy wall is characterized by the amplitude to wavelength ratio α = 0.05 and the ratio β between the wave amplitude and the half channel height where β = 0.1. The scalar is released from a point source at the wave crest. For the concentration measurements, Rhodamine B is used as tracer dye. At low to moderate Reynolds number, the flow field is characterized through a recirculation zone which develops after the wave crest. The recirculation zone induces high intensities of the fluctuations of the streamwise velocity and wall-normal velocity. Furthermore, large-scale structures are apparent in the flow field. In previous investigations it has been shown that these large-scale structures meander laterally in flows over wavy bottom walls. The investigations show a strong effect of the wavy bottom wall on the scalar mixing. In the vicinity of the source, the scalar is transported by packets of fluid with a high scalar concentration. As they move downstream, these packets disintegrate into filament-like structures which are subject to strong gradients between the filaments and the surrounding fluid. The lateral scale of the turbulent plume is smaller than the lateral scale of the large-scale structures in the flow field and the plume dispersion is dominated by the structures in the flow field. Due to the lateral meandering of the large-scale structures of the flow field, also the scalar plume meanders laterally. Compared to turbulent plumes in plane channel flows, the wavy bottom wall enhances the mixing effect of the turbulent flow and the spreading rate of the scalar plume is increase

Which Swiss Gnomes Attract Money? Efficiency and Reputation as Performance Drivers of Wealth Management Banks

Wealth management constitutes an important aspect of today's banking world, but very little is known about what explains the differences among banks in their ability to attract new assets under management. Using a unique panel database of Swiss private banks, we test the hypothesis that the performance of a bank in attracting new money depends on two input factors: skill and reputation. Relatively skilled banks -- that is, banks that are more cost-efficient than predicted by their input factors -- also perform better in attracting net new money. We also find that negative media coverage (such as in the context of fraudulent business practices related to tax evasion) strongly diminishes the future ability to attract assets under management, especially at small banks. The present value of lost profits is 3.35 (0.73) times the median annual net profit of a small (large) bank. Thus, adding to the explicit fines that many Swiss banks had to pay in the course of the U.S. Department of Justice's investigations, there are substantial implicit and reputational costs to banks of having negative media coverage. Investment performance for clients seems not to explain future net new money growth. In sum, these results underscore the importance of trust in money management