Application of Tethered Ruthenium Catalysts to Asymmetric Hydrogenation of Ketones,and the Selective Hydrogenation of Aldehydes

An improved method for the synthesis of tethered ruthenium(II) complexes of monosulfonylated diamines is described, together with their application to the hydrogenation of ketones and aldehydes. The complexes were applied directly, in their chloride form, to asymmetric ketone hydrogenation, to give products in excess of 99% ee in the best cases, using 30 bar of hydrogen at 60 °C, and to the selective reduction of aldehydes over other functional groups.     

Variability of Fresh Pork Belly Quality Evaluation Results Depends on Measurement Locations

The increase in pork demand has led to an especially high increase in demand for precisely quality-defined bellies. The aim of the study was to determine the influence of quality measurement location on the pork belly on the results of qualitative evaluation and then to recommend the main measurement locations required to determine the precise quality evaluation of the whole cut. The research material consisted of 92 fresh pork belly samples, each divided on 12 testing locations. The highest pH values were noted for M2 (5.74), M1 (5.70), and D3 (5.69) locations, as well as A4 (5.53; P?≤?0.05) generating the most outliers. Location D2 was distinguished by generally obtaining the highest values for parameters L*, b*, C*, and H* and the lowest for a*; this was independent of the measurement side. The highest water holding capacity values were reported for D4 and D3 locations, and the lowest (about 7% lower than the maximal values) were obtained for A4 and A2 locations. The highest values for the cooking loss parameter were noted for D4, D1, and M4 (about 33%) locations, and the lowest values were observed for location M2 (only 22%). In the case of sensory evaluation between the analyzed locations, differences (P?≤?0.05) were recorded for all parameters. It is recommended to evaluate belly quality using one location: A1 and M3 are most accurate. The highest position in the ranking for processing quality parameters was occupied by the middle locations: M4, M1, and M3. However, when consumers ranked important quality parameters, the highest positions were given to location A1 and then D3 and M2. From a practical point of view, it is highly recommended to take quality parameters from location A1, which is much easier to obtain, and obtaining samples from this location leads to the least damage to the structure of the whole commercial cut.     

Detection and characterization of altered conformations of protein pharmaceuticals using complementary mass spectrometry-based approaches

Unlike small-molecule drugs, the conformational properties of protein biopharmaceuticals in solution are influenced by a variety of factors that are not solely defined by their covalent chemical structure. Since the conformation (or higher order structure) of a protein is a major modulator of its biological activity, the ability to detect changes in both the higher order structure and conformational dynamics of a protein, induced by an array of extrinsic factors, is of central importance in producing, purifying, and formulating a commercial biopharmaceutical with consistent therapeutic properties. In this study we demonstrate that two complementary mass spectrometry-based approaches (analysis of ionic charge-state distribution and hydrogen/deuterium exchange) can be a potent tool in monitoring conformational changes in protein biopharmaceuticals. The utility of these approaches is demonstrated by detecting and characterizing conformational changes in the biopharmaceutical product interferon beta-1a (IFN-beta-1a). The protein degradation process was modeled by inducing a single chemical modification of IFN-beta1a (alkylation of its only free cysteine residue with N-ethylmaleimide), which causes significant reduction in its antiviral activity. Analysis of IFN-beta1a ionic charge-state distributions unequivocally reveals a significant decrease of conformational stability in the degraded protein, while hydrogen/deuterium exchange measurements provide a clear indication that the higher order structure is affected well beyond the covalent modification site. Importantly, neither technique required that the location or indeed the nature of the chemical modification be known prior to or elucidated in the process of the analysis. In contrast, application of the standard armamentarium of biophysical tools, which are commonly employed for quality control of protein pharmaceuticals, met with very limited success in detection and characterization of conformational changes in the modified IFN-beta1a. This work highlights the role mass spectrometry can and should play in the biopharmaceutical industry beyond the presently assigned task of primary structure analysis.     

Implementation and analysis of numerical solution of the population balance equation in CFD packages

Simulation of polydisperse flows must include the effects of particle–particle interaction, as breakage and aggregation, coupling the population balance equation (PBE) with the multiphase modelling. In fact, the implementation of efficient and accurate new numerical techniques to solve the PBE is necessary. The direct quadrature method of moments, known as DQMOM, is a moment-based method that uses an optimal adaptive quadrature closure and came into view as a promising choice for this implementation. In the present work, DQMOM was implemented in two CFD packages: the commercial ANSYS CFX, through FORTRAN subroutines, and the open-source OpenFOAM, by directly coding the PBE solution. Transient zero-dimensional and steady one-dimensional simulations were performed in order to explore the PBE solution accuracy using several interpolation schemes. Simulation cases with dominant breakage, dominant aggregation and invariant solution (equivalent breakage and aggregation) were simulated and validated against an analytical solution. The solution of the population balance equation was then coupled to the two-fluid model, considering that all particles classes share the same velocity field. Momentum exchange terms were evaluated using the local instantaneous Sauter mean diameter of the size distribution function. The two-dimensional tests were performed in a backward facing step geometry where the vortex zones traps the particles and provides high rates of breakage and aggregation.     

Ty3/gypsy-like retrotransposons in Candida albicans and Candida dubliniensis: Tca3 and Tcd3

Ty3/gypsy retrotransposons are a widespread group of eukaryote mobile genetic elements. They are similar in structure to, and may be ancestors of, the vertebrate retroviruses. Here we describe the first Ty3/gypsy retrotransposons from the pathogenic yeasts Candida albicans and Candida dubliniensis, which we refer to as Tca3 and Tcd3, respectively. Tca3 was first identified in a variety of strains as an element lacking a large part of its coding region. Comparative analyses between C. albicans and C. dubliniensis allowed us to identify the closely related full-length Tcd3 element, and, subsequently, the full-length Tca3 elements. The full-length versions of Tca3 and Tcd3 are broadly similar in structure to other Ty3/gypsy elements, but have several features of special interest, e.g. both elements appear to have a novel mechanism for priming minus-strand DNA synthesis, probably involving conserved secondary structures adjacent to the 5' LTRs. Also, while closely related to each other, the two elements appear to be fairly distantly related to other known Ty3/gypsy-like elements. Finally, the occurrence of the internally deleted forms of Tca3 in many strains raises interesting questions concerning the evolution of these transposable elements in Candida and the evolution of Candida itself. The sequences reported in this paper have been assigned GenBank Accession Nos AF499463, AF499464 and AF510498.     

In Vitro Evaluation of Rigosertib Antitumoral and Radiosensitizing Effects against Human Cholangiocarcinoma Cells

Cholangiocarcinoma is the first most common cancer of the biliary tract. To date, surgical resection is the only potentially curative option, but it is possible only for a limited percentage of patients, and in any case survival rate is quite low. Moreover, cholangiocarcinoma is often chemotherapy-resistant, and the only drug with a significant benefit for patient’s survival is Gemcitabine. It is necessary to find new drugs or combination therapies to treat nonresectable cholangiocarcinoma and improve the overall survival rate of patients. In this work, we evaluate in vitro the antitumoral effects of Rigosertib, a multi-kinase inhibitor in clinical development, against cholangiocarcinoma EGI-1 cell lines. Rigosertib impairs EGI-1 cell viability in a dose- and time-dependent manner, reversibility is dose-dependent, and significant morphological and nuclear alterations occur. Moreover, Rigosertib induces the arrest of the cell cycle in the G2/M phase, increases autophagy, and inhibits proteasome, cell migration, and invasion. Lastly, Rigosertib shows to be a stronger radiosensitizer than Gemcitabine and 5-Fluorouracil. In conclusion, Rigosertib could be a potential therapeutic option, alone or in combination with radiations, for nonresectable patients with cholangiocarcinoma.     

Abelès method revisited

The Abelès method is a classical method for determining the refractive index of dielectric thin films. In this paper we examine the main features of the method in a formal manner, using closed-form equations, and we show that the method is ambiguous in certain yet unreported situations.     

Solid phase microextraction (SPME) combined with gas-chromatography and olfactometry-mass spectrometry for characterization of cheese aroma compounds

The applicability of solid phase microextraction (SPME) as a technique for the concentration of cheese aroma for analysis by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-olfactometry (GC-O) was assessed in this preliminary study. Three each of the following cheese varieties were examined: cheddar, hard grating and mold-ripened blue. Volatile components were concentrated by Carboxen-PDMS SPME fibres for 16 h (overnight) and analysed by GC-MS and GC-O. Odor compounds, which could be perceived at the olfactory port (OP), were matched with electron impact (EI) and methanol chemical ionization (CI) mass spectra. The volatile compounds identified were compared to previously reported cheese aroma compounds. Of the components identified via olfactometry, methanethiol, methional, dimethyl trisulfide and butanoic acid were present in all of the cheeses implying their essential role in the formation of basic cheese aroma. A number of alkyl-pyrazines were also found to impart roasted nutty, raw potato and savoury broth-like notes in some of the cheeses. In all cases, the aroma active compounds identified via olfactometry were in agreement with those reported in the literature. In a separate study, it was demonstrated on a number of cheeses that the adsorption of most important aroma volatiles increased consistently up to 16 h; i.e. sulfur compounds, lactones, pyrazines, phenolic compounds and benzene derivatives. For the strong-smelling pecorino and blue cheeses, however, some analyte displacement effects were observed. Data indicated that a sampling time between 9 and 16 h was appropriate and displacement/competition reactions tended to occur in strong cheeses, i.e. those which have undergone extensive lipolysis e.g. pecorino, very high concentration of butanoic and hexanoic acid, and/or β-oxidation e.g. blue cheese, with high concentrations of 2-heptanone and 2-nonanone.     

Impact of Copper-Doped Mesoporous Bioactive Glass Nanospheres on the Polymerisation Kinetics and Shrinkage Stress of Dental Resin Composites

We embedded copper-doped mesoporous bioactive glass nanospheres (Cu-MBGN) with antibacterial and ion-releasing properties into experimental dental composites and investigated the effect of Cu-MBGN on the polymerisation properties. We prepared seven composites with a BisGMA/TEGDMA (60/40) matrix and 65 wt.% total filler content, added Cu-MBGN or a combination of Cu-MBGN and silanised silica to the silanised barium glass base, and examined nine parameters: light transmittance, degree of conversion (DC), maximum polymerisation rate (R_max), time to reach R_max, linear shrinkage, shrinkage stress (PSS), maximum PSS rate, time to reach maximum PSS rate, and depth of cure. Cu-MBGN without silica accelerated polymerisation, reduced light transmission, and had the highest DC (58.8 ± 0.9%) and R_max (9.8 ± 0.2%/s), but lower shrinkage (3 ± 0.05%) and similar PSS (0.89 ± 0.07 MPa) versus the inert reference (0.83 ± 0.13 MPa). Combined Cu-MBGN and silica slowed the R_max and achieved a similar DC but resulted in higher shrinkage. However, using a combined 5 wt.% Cu-MBGN and silica, the PSS resembled that of the inert reference. The synergistic action of 5 wt.% Cu-MBGN and silanised silica in combination with silanised barium glass resulted in a material with the highest likelihood for dental applications in future.