Technology

... subsurface water.(17-19) Chemical analysis of the organics at the sea surface has shown that ... 51) is believed to be necessary to reconcile observed gas-phase halogen concentrations with model calculations, which include all known gas-and solution-phase chemistry. ...

A fundamental study of the separation of homopolymers from polystyrene-block-polymethylmethacrylate (PS-b-PMMA) by liquid chromatography with preloaded discrete and continuous adsorption promoting barriers was performed. The impact of barrier composition on the separation of block copolymers (BCP) was studied by a dual detection (ultraviolet (UV) and evaporated light scattering (ELSD) detectors) system that enabled monitoring both barrier composition and BCP separation simultaneously. The separation of homopolymers from BCP by preloaded discrete adsorption promoting barriers was validated via a series of control experiments by blending known amounts of homopolymers PS or PMMA with PS-b-PMMA, and the resulting chromatograms were free from co-elution of homopolymers and BCP. Quantitation of homopolymers and BCP by ELSD was also demonstrated. The influence of BCP chemical composition on the separation by preloaded discrete adsorption promoting barriers was investigated. Results showed a PS-b-PMMA having 90wt% PMMA co-eluted with homopolymer PMMA, whereas PS-b-PMMA samples having lower amounts of PMMA block could be separated from homopolymer PMMA, successfully. Attempts at using a preloaded solvent gradient for separating homopolymers from block copolymers were unsuccessful. UV detection of the solvent gradient revealed significant deviation in solvent composition compared to the nominally loaded gradient. This deviation was due to the interaction of strong desorption solvent with column stationary phase. As such, the barrier composition in the preloaded gradient method was not as expected. Therefore, one can obtain undesired separation results by preloaded solvent gradients.

Recent advances in catalyst technology have enabled the synthesis of olefin block copolymers (OBC). One type is a "hard-soft" OBC with a high density polyethylene (HDPE) block and a relatively low density polyethylene (VLDPE) block targeted as thermoplastic elastomers. Presently, one of the major challenges is to fractionate HDPE segments from the other components in an experimental OBC sample (block copolymers and VLDPE segments). Interactive high temperature liquid chromatography (HTLC) is ineffective for OBC separation as the HDPE segments and block copolymer chains experience nearly identical enthalpic interactions with the stationary phase and co-elute. In this work we have overcome this challenge by using liquid chromatography under the limiting conditions of desorption (LC LCD). A solvent plug (discrete barrier) is introduced in front of the sample which specifically promotes the adsorption of HDPE segments on the stationary phase (porous graphitic carbon). Under se...

A Russian Doll encapsulation architecture utilizing pairs of free-standing barrier films and epoxy seals separated by nitrogen spacers is presented, enabling the use of low-cost epoxy to attach two or more free-standing barrier films to a substrate with improved barrier performance. The performance of various Russian Doll encapsulations was evaluated with the calcium thin film optical transmission test, showing improved performance of the Russian doll configuration relative to a non-nested barrier/spacer architecture, and demonstrating that water vapor transmission rates of 0.0021 g/(m^2, day) or below can be achieved with low-cost materials in this architecture. This WVTR correlates to a predicted lifetime of more than 10 years for inverted organic P3HT:PCBM bulk heterojunction solar cell modules fabricated and tested by Konarka Technologies (Lowell, MA, USA).

A Russian Doll encapsulation architecture utilizing pairs of free-standing barrier films and epoxy seals separated by nitrogen spacers is presented, enabling the use of low-cost epoxy to attach two or more free-standing barrier films to a substrate with improved barrier performance. ...

The studies described in this report were performed to determine, whether it is possible to produce live virus vaccines without serum or fractions thereof used during any cell or virus passage, thus completely serum-free. Two viruses were included in the experiments: Bovine Herpesvirus 1 (BHV-1) and Bovine Parainfluenza type 3 virus (PI3). Both viruses were found to grow to satisfactory titers, and to be stable after freeze-drying and subsequent storage at temperatures of +4 degrees C and -20 degrees C for at least one year. Moreover, a vaccine containing serum free produced BHV-1 was tested in a vaccination-challenge experiment. For comparison, a vaccine batch with BHV-1 grown in serum-containing cell culture medium was included in the study. Both vaccine preparations performed equally well and both met the strict requirements as laid down in the European Phamacopeia. Moreover, in two separate experiments the safety of serum-free produced BHV-1 and PI3 after overdose and repeated a...

A cell's ability to recognize and adapt to the physical environment is central to its survival and function, but how mechanical cues are perceived and transduced into intracellular signals remains unclear. In mesenchymal stem cells (MSC), high magnitude substrate strain (HMS, ≥2%) effectively suppresses adipogenesis via induction of FAK/mTORC2/Akt signaling generated at focal adhesions [1]. Physiologic systems also rely on a persistent barrage of low level signals to regulate behavior [2]. Exposing MSC to extremely low magnitude mechanical signals (LMS) suppresses adipocyte formation [3] despite the virtual absence of substrate strain(<0.001%) [2], suggesting that LMS-induced dynamic accelerations can generate force within the cell. Here we show that MSC response to LMS is enabled through mechanical coupling between the cytoskeleton and the nucleus, in turn activating focal adhesion kinase (FAK) and Akt signaling followed by FAK-dependent induction of RhoA. While LMS and HMS ...

Gold nanoshells around 26 nm in diameter with a 7 nm thick wall were fabricated in an aqueous solution using pre-reconstituted ferritin proteins as a removable bio-template. The synthesis of gold nanoshells was initiated by planting gold nanoparticle seeds in the hydrophilic three-fold channels of the ferritin protein. The process was facilitated by the energetically favorable gold-sulfur bonds formed at the cysteine residues lining these channels.

ABSTRACT We present a facile, one-step, and surfactant-free method for direct synthesis and loading of stable gold and gold-alloy nanoparticles (NPs) on large-area graphene using an electrical discharge in a liquid environment, termed solution plasma. We observed a charge doping of graphene by the gold NPs, which depends on the particles’ chemical composition, even if the NPs contain a few percent of trivalent sp metals, such as indium (In) or gallium (Ga). Raman and electron energy loss spectroscopy (EELS) methods show that graphene is doped with electrons (n-type) in the case of gold NPs and with holes (p-type) in the case of gold-alloy NPs. The Raman band shift indicates that the amount of the transferred electrons from the gold NPs to graphene is −2 × 10–4 electrons per unit cell. The gold-alloy NPs receive from graphene (2 and 4) × 10–5 electrons per unit cell if the gold NPs contain In and Ga, respectively. In the EELS spectra, the decrease in the intensity of the 1s-π* transition and the shift of the π* peak to higher energy confirm the depopulation of the antibonding states caused by the electron transfer from graphene to the gold-alloy NPs.

Bunch-shaped ZnO nanowires film was successfully fabricated by the forced-hydrolysis-initiated-nucleation of anhydrous zinc acetate in an aqueous solution of zinc acetate and sodium hydroxide at low temperature. X-ray diffraction and a field emission scanning electron microscope clarified their formation mechanism and morphology development. The morphology was controllable by adjusting the solution temperature and deposition time. ZnO nanowires obtained at 65 degrees C for 6 h have a high aspect ratio of about 106. The smaller diameter with higher aspect ratio of ZnO nanowires, the easier the formation of bunch shapes by the capillary force during the drying process. This fabrication technique indicated that bunched ZnO film was prepared at low cost, and fittable to low heat-resistance substrates such as a polymer substarte.

ABSTRACT We study the electronic structure of Co, Ni, and Cu impurities and of their vacancy-associated complexes in SrTiO3 crystals by means of density functional theory (DFT) and DFT + U calculations. Simple substitutionals prefer low-spin states, as expected from ligand field theory. On the other hand, the formation energy of vacancies (which tend to stay close to the impurity) is rather low for all the doped systems, and decreases with Z. This reflects the low stability of the +IV oxidation state for the impurities. Contrary to simple impurities, high-spin states are predicted to be stable when impurities are associated to vacancies.

We analyze the behavior in several solvents of a perspective metal sensor, namely benzonitrile (DMABN-Crown5), a derivative of 4-(N,N-dimethylamino) benzonitrile (DMABN) that exhibits a dual fluorescence due to a twisted intra-molecular charge transfer process. To this end, we extend a stochastic modeling previously employed for DMABN, in which internal degrees of freedom are coupled with an effective solvent relaxation variable. Evaluation of potential energy surfaces using advanced QM approach and estimates of dissipative parameters based on hydrodynamic arguments are discussed. Emission fluorescence is calculated by solving a diffusion/sink/source equation for the stationary population of excited state, and compared to experimentally measured emission fluorescence of DMABN-Crown5.

ABSTRACT Olive oil phenolic and secoiridoid compound derivatives were detected by mass spectrometry. Chemical ionization (CI) allowed us to obtain parent ions, that were not detectable in the electron impact mode. CI experiments were performed using either CH4 or NH3 as the reactant gas. Unlike CH4-CI, which fails to give molecular mass information, NH3-CI provided, in all the cases explored, an adduct ion [M+18]+ that was sufficiently stable to be detected and recorded. Information about molecular masses was very useful for the complete characterization of aglycons from glycosides occurring in virgin olive oils. Aglycons of ligstroside, of decarbomethoxyoleuropein and of oleuropein were detected. Each aglycon, because of several tautomeric equilibria involving the ring opening of secoiridoid, showed up as compounds with four main structures after derivatization with bis(trimethylsilyl)trifluoracetamide.

The predictive capability of the retention time prediction model based on quantitative structure-retention relationships (QSRR) was tested. QSRR model was derived with the use of set of peptides identified with the highest scores and originated from 8 known proteins annotated as model ones. The predictive ability of the QSRR model was verified with the use of aBacillus subtilisproteome digest after separation and identification of the peptides by LC-ESI-MS/MS. That ability was tested with three sets of testing peptides assigned to the proteins identified with different levels of confidence. First, the set of peptides identified with the highest scores achieved in the search were considered. Hence, proteins identified on the basis of more than one peptide were taken into account. Furthermore, proteins identified on the basis of just one peptide were also considered and, depending on the possessed scores, both above and below the assumed threshold, were analyzed in two separated sets....