Die Abtrennung von Ölsäuremonoglycerid aus einem Glyceridgemisch mit Hilfe eines überkritischen Extraktionsmittels

Separation of Glycerol-monooleate from a Mixture of Glycerides by Means of a Supercritical Extractant The continuous separation of pure monoglycerides out of a mixture of glycerides by means of supercritical fluid extraction was investigated. As supercritical extracting agent carbon dioxide containing propane as an entrainer was used. The phase equilibria concerning the process were measured and are discussed. In an extraction apparatus consisting of an extraction column and two separators the viability of the process was tested. At 40°C and 120 bar a product with 99.5 wt.% monoglycerides was manufactured out of a mixture of glycerides containing 59 wt.% monoglycerides.     

Evaluation of a new instrument offering sodium,potassium, and ionized calcium in combination with haematocrit,pH and blood gas analysis; the performance of the Nova Stat Profile 1

The Nova Stat Profile 1 analyser, a combined sodium, potassium, ionized calcium, haematocrit and conventional blood gas analyser, was evaluated over a four month period. In addition to assessing and demonstrating that the instrument met analytical requirements, an appreciation of the use of ionised calcium (iCa) was made. Prospective costs were characterised and practical problems of iCa measurement addressed.     

Comparative interference by haemolysis in automated assays for bilirubin at multiple analyte concentrations

The negative interference caused by haemolysis in manual bilirubin assays contrasts with the positive interference reported for some automated methods utilizing the same basic chemistry. A comparison was therefore made of the haemolysis interference associated with several automated bilirubin methodologies: multilayer film (Kodak Ektachem- total bilirubin (TBil), direct bilirubin (DBil), conjugated bilirubin (Bc), unconjugated bilirubin (Bu),; tableted reagents (Baxter Paramax- TBil, DBil); continuous flow (Technicon SMAC — TBil). Thirty serum pools were analysed (five concentrations of bilirubin, 2-229 μmol/l; six concentrations of haemoglobin, 0.00002-0.052 mmol/1). All methods, except one (Bc), exhibited both positive and negative interference, depending upon the relative haemoglobin and bilirubin concentrations. This interference, at any given haemoglobin concentration, was neither constant nor proportional with increasing bilirubin concentration. These complex patterns of interference suggest that the best characterization of interference is obtained when (1) both percentage-difference and absolute-difference ‘interferographs’ are plotted; and (2) the interference is determined at multiple analyte concentrations.     

N-(2-Hydroxyethyl)formamide as a new plasticizer for thermoplastic starch

N-(2-Hydroxyethyl)formamide (HF) was synthesized efficiently and used as a new plasticizer for corn starch to prepare thermoplastic starch (TPS). The hydrogen bond interaction between HF and starch was proved by Fourier-transform infrared (FT-IR) spectroscopy. Scanning electron microscope (SEM) revealed that starch granules were completely disrupted and a continuous phase was obtained. The crystallinity of corn starch and HF-plasticized TPS (HTPS) were characterized by X-ray diffraction (XRD). The glass transitions of glycerol-plasticized TPS (GTPS) and HTPS were investigated by differential scanning calorimetry (DSC). The water resistance of GTPS was better than that of HTPS. In addition, the flexibility of HTPS was better than that of GTPS at low relative humidity.     

Dynamic operability analysis of nonlinear process networks based on dissipativity

Most modern chemical plants are complex networks of multiple interconnected nonlinear process units, often with multiple recycle and by‐pass streams and energy integration. Interactions between process units often lead to plant‐wide operability problems (i.e., difficulties in process control). Plant‐wide operability analysis is often difficult due to the complexity and nonlinearity of the processes. This article provides a new framework of dynamic operability analysis for plant‐wide processes, based on the dissipativity of each process unit and the topology of the process network. Based on the concept of dissipative systems, this approach can deal with nonlinear processes directly. Developed from a network perspective, the proposed framework is also inherently scalable and thus can be applied to large process networks. © 2009 American Institute of Chemical Engineers AIChE J, 2009     

Structure and composition of CO2/H2 and CO2/H2/C3H8 hydrate in relation to simultaneous CO2 capture and H2 production

Gas hydrates from a (40/60 mol %) CO₂/H₂ mixture, and from a (38.2/59.2/2.6 mol %) CO₂/H₂/C₃H₈ mixture, were synthesized using ice powder. The gas uptake curves were determined from pressure drop measurements and samples were analyzed using spectroscopic techniques to identify the structure and determine the cage occupancies. Powder X‐ray diffraction (PXRD) analysis at ?110°C was used to determine the crystal structure. From the PXRD measurement it was found that the CO₂/H₂ hydrate is structure I and shows a self‐preservation behavior similar to that of CO₂ hydrate. The ternary gas mixture was found to form pure structure II hydrate at 3.8 MPa. We have applied attenuated total reflection infrared spectroscopic analysis to measure the CO₂ distribution over the large and small cavities. ¹H MAS NMR and Raman were used to follow H₂ enclathration in the small cages of structure I, as well as structure II hydrate. © 2009 American Institute of Chemical Engineers AIChE J, 2009     

Thermoforming starch‐graft‐polycaprolactone biocomposites via one‐pot microwave assisted ring opening polymerization

A thermoformable starch‐graft‐polycaprolactone biocomposite was prepared by initiating ring‐open polymerization of caprolactone monomer onto starch under microwave irradiation. In this case, the thermoplastic and hydrophobic modification of starch could be realized by one‐pot grafting PCL, where the grafted PCL chains acted as the “plasticizing” tails of thermoforming and as the hydrophobic species of water‐resistance. The resultant biocomposites were injection‐molded as the sheets and their structure and properties were investigated by Fourier transform infrared spectroscopy, X‐ray diffraction, scanning electron microscopy, differential scanning calorimetry, dynamic mechanical analysis, contact angle measurement, and tensile testing. In this case, the grafted PCL chains entangled each other, and hence contributed to the strength and elongation of biocomposites. This work provided a simple strategy of one‐pot thermoplastic and hydrophobic modification of starch, and may be applied in a continuous process of modification, compounding, and molding. Meanwhile, the resultant biocomposites containing starch are believed to have a great potential application as an environment‐friendly and/or biomedical material. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Discovery of Riociguat (BAY 63‐2521): A Potent,Oral Stimulator of Soluble Guanylate Cyclase for the Treatment of Pulmonary Hypertension

Direct stimulation of soluble guanylate cyclase (sGC) represents a promising therapeutic strategy for the treatment of a range of diseases, including the severely disabling pulmonary hypertension (PH). Optimization of the unfavorable DMPK profile of previous sGC stimulators provided riociguat, which is currently being investigated in phase III clinical trials for the oral treatment of PH.

     

Truncation and Optimisation of Peptide Inhibitors of Cyclin‐Dependent Kinase 2‐Cyclin A Through Structure‐Guided Design

Peptides that inhibit cyclin‐dependent kinase 2 by blocking the macromolecular substrate recruitment site of cyclin A were simplified, for example, by replacement of dipeptide units with β‐amino acids. The smallest inhibitor retaining activity was a tripeptide, whose binding mode was confirmed by X‐ray crystallography. This result suggests that nonpeptidic cyclin groove inhibitors may be feasible therapeutic agents.