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Runaway Reactions – Their Course and Methods for the Choice and Design of Safe Processes. Literature about runaway reactions is usually concerned with the consequences of explosions such as destruction and emission of hazardous and inflammable substances. DIERS literature describes methods for the design of relief orifices for which experimental studies are necessary. Only few data are available relating to the course of runaway reactions, which, more-over, are also attributable to variety of causes. The present report describes the various process deviations which can trigger a thermal explosion. In addition, the determination of the necessary data and considerations for risk analysis and for the development of inherently safe processes and for lessening the consequences of thermal explosions are discussed. Any possible dangerous process deviation is illustrated with the aid of examples and experimental data obtained in laboratory experiments. The various dangerous process states which can lead to a thermal explosion are thus subjected to systematic study.     

Influence of a Constant Magnetic Field on Nervous Tissues: II. Voltage-Clamp Studies

In this paper a study of the biomagnetic response of the lobster nerve membrane is reported. Experiments were made on the giant axon of the circumesophageal connective of the lobster in order to investigate the influence of a constant strong magnetic field upon the membrane potentials and the transmembrane currents under voltage-clamp conditions, using the double sucrose gap technique. It was found that within the uncertainties and limitations of these experiments, neither the membrane potentials nor the transmembrane currents were affected in any detectable manner by a constant 1.2 T magnetic field parallel or perpendicular to the axon.     

Analysis of furin ectodomain shedding in epididymal fluid of mammals: demonstration that shedding of furin occurs in vivo

Sperm cell surface proteins and proteins of their surrounding fluids are reported to be proteolytically processed in relation to acquisition of sperm fertility during epididymal transit. Several of these proteins might be potential targets for subtilisin-like pro-protein convertase. Using immunochemistry and mass spectrometry analysis, we found that an 80 kDa form of furin (EC 3.4.21.75) is present in the fluid from the mid-caput to the distal corpus regions of the epididymis of various domestic mammals. This protein is absent from the fluid of the caudal region, suggesting that it is reabsorbed or degraded. The cDNA sequence of ovine furin was obtained and the mRNA was found throughout this organ, although in greater amounts in the mid and distal caput regions. Metabolic labeling with (35)S-amino acids indicated that the protein was synthesized and released from the epithelium only in a restricted area of the mid-caput, suggesting a specific regionalized mechanism of secretion. The fluid protein is not pelleted at 100 000 g and did not react with a C-terminal antibody indicating that it is not bound to membranous materials. These findings demonstrate that a furin ectodomain shedding occurs naturally in vivo in the epididymis where this enzyme could be involved in fluid and/or sperm membrane protein processing.     

DETERMINATION OF THE METASTABLE ZONE WIDTH OF GLYCINE AQUEOUS SOLUTIONS FOR BATCH CRYSTALLIZATIONS

The aim of this study was to determine the metastable zone width of aqueous solutions of glycine for non-seeded batch crystallizations. The saturation curve was determined by studying the heating rate influence on the apparent saturation temperatures of several solutions. A linear regression was then applied to obtain the saturation temperatures. The spontaneous nucleation curve was obtained by measuring the crystallization temperatures of several solutions at different cooling rates. The results show that the apparent nucleation order of the glycine aqueous solutions was around 3.5 ± 0.5. Moreover, from the experimental data, a second-order polynomial model was established by using the experimental design method. This model enables the expression of crystallization temperature to be defined as a function of concentration and cooling rate. The results show that the model fits well (R² > 0.99; Q² > 0.98) and that the cooling rate is the most influential parameter.     

Estimating non-fatal road casualties in a large French county, using the capture-recapture method

INTRODUCTION: Non-fatal road casualties are under-reported, with official figures coming from the police. In the French Rh?ne county, a road trauma registry constitutes a second source of reporting but its completeness needs to be assessed. We also wish to estimate an incidence rate of non-fatal road casualties that is corrected for under-count. METHODS: Having two sources of reporting available, we can apply the capture-recapture method under certain conditions. To take into account different reporting probabilities among casualties, the capture-recapture analysis is stratified according to injury severity (New Injury Severity Score=NISS), road user type and human third party. To evaluate the sensitivity of the capture-recapture estimate on the number of matched casualties between the police file and the registry, three scenarios of record-linkage are considered. RESULTS: For serious (NISS 9+) non-fatal road casualties, the police ascertainment rate is at most 57%, the registry ascertainment rate is at most 87%, and the aggregate ascertainment rate is at most 95%. The ascertainment-corrected incidence rate for serious (NISS 9+) non-fatal road casualties is at least 65 per 100,000. CONCLUSION: The degree of completeness of the registry for serious casualties is rather high, though not satisfactory.     

High-finesse Fabry-Perot electro-optic sensors with enhanced sensitivity and high spatial resolution

We present a high-finesse optical cavity containing a LiTaO(3) electro-optic crystal, devoted to free-space electric field characterization. Theoretical considerations will show that the modulation depth is directly related to the transversal components of the field to be measured, thus opening the way to vectorial mapping of the electric field using a single electro-optic crystal. Also, a discussion about noise and sensitivity will be given. As the latter increases with the effective cavity length, and bandwidth decreases, a trade-off is realized, allowing us to measure an electric field of 60 mV/m/ sqrt[Hz] in a 110 MHz bandwidth. Cavity dimensions are less than 8 mm(3), giving an inner-crystal transverse spatial resolution of 70 microm and allowing pigtailed systems to integrate.     

Five-substrate cocktail as a sensor array for measuring enzyme activity fingerprints of lipases and esterases

Substrate arrays for measuring enzyme activity fingerprints can be conveniently formulated as cocktails designed such that the reaction products can be separated and quantified by analytical high-performance liquid chromatography (HPLC). Fingerprinting of lipases and esterases, an important class of microbial enzymes, is reported with a cocktail of only five substrates as a practical fingerprinting reagent. An unusually strong C4-esterase activity was thus revealed in a recently discovered microbial esterase.     

Analysis of Amyloid-β Peptides in Cerebrospinal Fluid Samples by Capillary Electrophoresis Coupled with LIF Detection

We report a CE-LIF method for the separation and detection of five synthetic amyloid-β peptides corresponding to an important family of CSF-biomarkers in the context of Alzheimer disease (AD). The presumed most relevant peptides (Aβ1-42, Aβ1-40, and Aβ1-38) that may support the differentiation between AD and healthy patients or other dementias were successfully detected in CSF by incorporating an immunoconcentration step prior to CE analysis of derivatized peptides. We labeled the Aβ peptides with a fluoroprobe dye before CE-LIF analysis. This reagent reacts with the amino groups of lysine residues and produced mostly ditagged Aβ peptides under the proposed experimental conditions. The labeling reaction displayed similar efficiency with each one of the five different synthetic Aβ peptides that were tested. The limit of detection of the CE-LIF method approached 280 attomoles of injected synthetic labeled Aβ peptides. We obtained excellent correlation between peak areas and peptide concentrations from 35 nM to 750 nM. For the detection of Aβ peptides in human CSF samples, we enriched the peptides by immunoprecipitation prior to the CE-LIF analysis. The comparison of the CE-LIF profiles obtained from CSF samples from 3 AD patients and 4 non-demented control subjects indicated noticeable differences, suggesting that this method, which relies on a multibiomarker approach, may have potential as a clinical diagnostic test for AD.     

New insight into marine alkaloid metabolic pathways: revisiting oroidin biosynthesis

Sponge natural product biosynthesis: A highly sensitive in vivo protocol based on (14)C radiolabeled precursors and beta-imager autoradiography allowed the unraveling of the origin of the pyrrole 2-aminoimidazole-containing key biosynthetic intermediate oroidin. Proline and lysine are now proposed as the early precursors of the pyrrole and the 2-aminoimidazole moieties of oroidin respectively.     

Trends to Attain a Lower Interfacial Tension in a Revisited Pure Alkyl Polyethyleneglycol Surfactant–Alkane–Water Ternary System. Basic Concepts and Straightforward Guidelines for Improving Performance in Enhanced Oil Recovery Formulations

Surfactant–oil–water systems exhibit a low interfacial tension minimum when the interactions between the adsorbed surfactant with water exactly coincide with its interactions with oil. This occurrence takes place at the so‐called optimum formulation, which was conceptually derived by Winsor in the 1950s and rendered by numerical correlations for enhanced oil recovery in the 1970s. The actual low value of the interfacial tension minimum has been found to increase or decrease with formulation variables and though some hints are available, no general relationship has been reported up to now, probably because too many variables are involved in complex interactions. It is shown in the present article that a linear relationship between low‐tension performance and formulation variables can be found for very simple ternary systems containing a pure ethoxylated alcohol, n‐alkane and water at variable temperature, i.e., when there are only four degrees of freedom. In such a case the iso‐performance contours studied in bi‐dimensional spaces are reported to be almost straight lines and as a consequence the path to lower the tension through formulation adjustments is easy to find as being perpendicular as possible to the contours. On the other hand, it is shown that displacing the limit of restrictions like the surfactant precipitation boundary is a priority issue, thus justifying many trends which have been proposed on empirical grounds in the past years. The reported simple guidelines for a simple surfactant–oil–water ternary is likely to considerably facilitate the formulator's work in a real system with a score of formulation variables.