Determination of Phosphorus in Brazilian Soya Bean Oils by the Saponification Method

The phosphorus contents of crude and degummed Brazilian soya bean oils were determined by a modified saponification method. The method consists in saponifying the oil with a 50% sodium hydroxide solution at 180°C, acidifying with hydrochloric acid, extracting the liberated fatty acids with hexane and determining the phosphorus in the aqueous solution spectrophometrically as molybdenum blue. The determination requires less than 3 hours of work and shows good agreement with the ashing method of the American Oil Chemists' Society. The results showed that Brazilian crude soya bean oils contain less total phospholipids but proportionally more non-hydratable phosphatides than the North American ones, this being specially evident in the equatorial region of Brazil. The high content of non-hydratable phosphatides impedes the determination of acetone-insolubles in crude oils and the application of the conventional conversion factors of phosphorus into phosphatides.     

Bruton's tyrosine kinase regulates apoptosis and JNK/SAPK kinase activity

Mast cells derived from Bruton's tyrosine kinase (Btk)-defective xid or btk null mice showed greater expansion in culture containing interleukin-3 (IL-3) than those from wild-type (wt) mice. Although the proliferative response to IL-3 was not significantly different between the wt and xid mast cells, xid and btk null mast cells died by apoptosis more slowly than their wt counterparts upon IL-3 deprivation. Consistent with these findings, the apoptosis-linked c-Jun N-terminal kinase/stress-activated protein kinase (JNK) activity was compromised in these btk-mutated cells upon Fc(epsilon)RI crosslinking or upon stimulation with IL-3 or with stem cell factor. p38 activity was less severely, but significantly, affected by btk mutation, whereas extracellular signal-regulated kinases were not affected by the same mutation. Btk-mediated regulation of apoptosis and JNK activity was confirmed by reconstitution of btk null mutant mast cells with the wt btk cDNA. Furthermore, growth factor withdrawal induced the activation and sustained activity of JNK in wt mast cells, while JNK activity was consistently lower in btk-mutated mast cells. These results support the notion that Btk regulates apoptosis through the JNK activation.     

Preparation of Medium Chain Triglycerides with the Use of Physical Refining

The application of medium chain triglycerides (MCTs) of fatty acids, mainly with C₈ and C₁₀ carbon atoms, has extended in recent years from their original clinical use for patients with deficient lipid metabolism to their utilization in infant and parenteral feedings. They may be useful in treating obesity and various other ailments. The medium chain fatty acids are prepared by fractional distillation of coconut and palmkernel oil fatty acids and the industrial synthesis of MCTs is much more complicated than the preparation of common edible oils. The esterification of medium chain fatty acids with glycerol must lead to an almost complete elimination of monoglycerides because of their bitter taste. The free fatty acid content of the end product has to be very low and the deodorization step creates problems owing to the hydrolysing action of the steam. The necessity of using a large excess of fatty acids in the esterification step to eliminate the monoglycerides, results in considerable refining losses, which increase the cost of MCTs manufacture. The present investigation was carried out with the object of replacing the alkali treatment of the esterified product by physical refining, i.e. by the removal of free fatty acids by distillation. This was achived by dispensing with the use of a catalyst during the esterification and by using nitrogen or preferably carbon dioxide instead of steam during the deacidification-deodorization step. This permitted a substantial increase in the temperature of the precess and the formation of a satisfactory product in a reasonable working time.     

The molecular pathway for the regulation of phosphoribulokinase by thioredoxin f

Phosphoribulokinase (PRK) is one of several plant enzymes that is regulated by thiol-disulfide exchange as mediated by thioredoxin, which contains spatially vicinal, redox-active cysteinyl residues. In an earlier study (Brandes, H. K., Larimer, F. W., Geck, M. K., Stringer, C. D., Schürmann, P., and Hartman, F. C. (1993) J. Biol. Chem. 268, 18411-18414), our laboratory identified Cys-46 of thioredoxin f (Trx), as opposed to the other candidate Cys-49, as the primary nucleophile that attacks the disulfide of target proteins. The goal of the present study was to identify which of the two redox-active cysteinyl residues of PRK (Cys-16 or Cys-55) is paired with Cys-46 of Trx in the interprotein disulfide intermediate of the overall oxidation-reduction pathway. Incubation of a mixture of the C16S mutant of PRK and the C49S mutant of Trx with Cu2+ results in covalent complex formation as detected by SDS-polyacrylamide gel electrophoresis. Complexation is fully reversible by dithiothreitol and is retarded by ligands for PRK. Under the same conditions, Cu2+ induces very little complex formation between the following pairs of mutants: C16S PRK/C46S Trx, C55S PRK/C49S Trx, and C55S PRK/C46S Trx. When either 5-thio-2-nitrobenzoate-derivatized C16S or C55S PRK, as mimics of the oxidized (disulfide) form of the enzyme, is mixed with C49S Trx, stable covalent complex formation occurs only with the C16S PRK. Thus, two independent approaches identify Cys-55 of PRK in the intermolecular disulfide pairing with Trx.     

Farnesyltransferase inhibitors versus Ras inhibitors

BACKGROUND: Intra-arterial regional anaesthesia (IARA) may be useful for ambulatory hand surgery in patients with poor veins. This randomized, double-blind study assessed which of the three doses of lignocaine gives the optimal analgesia with a minimum of adverse effects. METHODS: A preservative-free, alkalinized 0.5% lignocaine 1, 2 or 2.89 mg/kg body weight was injected into the radial arteries of 60 adult patients, allocated to three equal groups, to produce anaesthesia for carpal tunnel releases, capsulotomies, tenosynovectomies, palmar fasciectomies, Z-plastics, arthroplastics, arthrodeses etc. RESULTS: Surgical analgesia and motor block were best in group 3 (P < 0.01), whereas injection and tourniquet pain scores were similar in the three groups. Onset of analgesia was similar in all groups, and varied between 2 and 15 min. Cannulation time, surgery start time and tourniquet time were also similar in all groups, as were operating conditions and patient's acceptance of the method. No significant cardiovascular changes were observed after tourniquet release in any of the groups. Plasma lignocaine concentrations were lowest in group 1 (1 mg/kg) (P < 0.001). Five patients in group 1, seven in group 2 and seventeen in group 3 developed small bruises at the cannulation site (P < 0.001). Six patients (two in group 1, three in group 2 and one in group 3) had minor symptoms of lignocaine toxicity after tourniquet release (NS). No other complications were observed. CONCLUSIONS: The highest dose of lignocaine produces best surgical analgesia, without increasing the risk of toxicity. However, many patients receiving this dose will develop bruises at the injection site, and an occasional patient may need supplemental analgesia.     

Certification of NIST SRM 1962: 3 μm Diameter Polystyrene Spheres

This report describes the certification of SRM 1962, a NIST Standard Reference Material for particle diameter. It consists of an aqueous suspension of monosize 3 (μm polystyrene spheres. Two calibration techniques were used: optical microscopy and electron microscopy. The first one gave a mean diameter of D¯=2.977±0.011 μm and a standard deviation of the size distribution σ_D = 0.020 μm, based on measurement of 4600 spheres. The second technique gave D¯=2.990±0.009 μm, based on measurement of 120 spheres. The reported value covering the two results is D¯=2.983 μm with a maximum uncertainly of 0.016 μm, with σ_D=0.020 μm.     

Microform calibrations in surface metrology

Microform calibrations include the measurement of complex profile forms and position errors of micrometer scale in combination with the measurement of deviations from a specified profile and surface texture of profile segments. Tolerances on the profile form are specified and may correspond geometrically to surface texture parameters. One example of microform calibration is the calibration of Rockwell diamond indenters used for hardness testing of materials. Previously reported measurement techniques do not meet the stringent microfonn calibration requirements for Rockwell diamond indenters. Inadequate microform calibration of hardness indenters may be one factor resulting in significant interlaboratory differences in results from Rockwell hardness tests. By using a stylus instrument, in combination with a series of calibration and check standards and calibration and measurement uncertainty calculation procedures, we have calibrated Rockwell diamond indenters in accordance with the definitions specified in ISO and ASTM standards. Our procedures for conducting microform calibration yield total measurement uncertainties less than ten percent of the tolerance values specified in ISO and ASTM standards. In this paper, the general calibration requirements, calibration and check standards, and calibration and uncertainty procedures that we use in performing microform calibrations are introduced. Some general considerations on stylus radius correction, data fitting, calibration traceability, uncertainty and reproducibility are also discussed.     

Quantitative characterization of the x-ray imaging capability of rotating modulation collimators with laser light

We developed a method for making quantitative characterizations of bi-grid rotating modulation collimators (RMC's) that are used in a Fourier transform x-ray imager. With appropriate choices of the collimator spacings, this technique can be implemented with a beam-expanded He-Ne laser to simulate the plane wave produced by a point source at infinity even though the RMC's are diffraction limited at the He-Ne wavelength of 632.8 nm. The expanded beam passes through the grid pairs at a small angle with respect to their axis of rotation, and the modulated transmission through the grids as the RMC's rotate is detected with a photomultiplier tube. In addition to providing a quantitative characterization of the RMC's, the method also produces a measured point response function and provides an end-to-end check of the imaging system. We applied our method to the RMC's on the high-energy imaging device (HEIDI) balloon payload in its preflight configuration. We computed the harmonic ratios of the modulation time profile from the laser measurements and compared them with theoretical calculations, including the diffraction effects on irregular grids. Our results indicate the 25-in. (64-cm) x-ray imaging optics on HEIDI are capable of achieving images near the theoretical limit and are not seriously compromised by imperfections in the grids.     

Identified research directions for using manufacturing knowledge earlier in the product life cycle

Design for manufacturing (DFM), especially the use of manufacturing knowledge to support design decisions, has received attention in the academic domain. However, industry practice has not been studied enough to provide solutions that are mature for industry. The current state of the art for DFM is often rule-based functionality within computer-aided design (CAD) systems that enforce specific design requirements. That rule-based functionality may or may not dynamically affect geometry definition. And, if rule-based functionality exists in the CAD system, it is typically a customisation on a case-by-case basis. Manufacturing knowledge is a phrase with vast meanings, which may include knowledge on the effects of material properties decisions, machine and process capabilities or understanding the unintended consequences of design decisions on manufacturing. One of the DFM questions to answer is: How can manufacturing knowledge, depending on its definition, be used earlier in the product life cycle to enable a more collaborative development environment? This paper will discuss the results of a workshop on manufacturing knowledge that highlights several research questions needing more study. This paper proposes recommendations for investigating the relationship of manufacturing knowledge with shape, behaviour and context characteristics of a product to produce a better understanding of what knowledge is most important. In addition, the proposal includes recommendations for investigating the system-level barriers to reusing manufacturing knowledge and how model-based manufacturing may ease the burden of knowledge sharing. Lastly, the proposal addresses the direction of future research for holistic solutions of using manufacturing knowledge earlier in the product life cycle.