Trimellitic anhydride Toxicity. A cause of acute multisystem failure

A person exposed to trimellitic anhydride (TMA) an epoxy resin widely used in industry, experienced respiratory failure, anemia, and gastrointestinal bleeding. A lung biopsy specimen demonstrated intra-alveolar hemorrhage and damage to alveolar lining cells. The patient and six co-workers were examined. Results indicated the presence of hemolytic antibodies directed against TMA-haptenized erythrocytes, IgG, IgA, and IgM antibodies directed against TMA-erythrocyte complexes, and antibodies against TMA-human serum albumin. Antibody levels in the patient were greater than in the co-workers. The elevated antibody levels demonstrate the antigenic potential of TMA. However, the cause of the pulmonary and hematologic damage remains uncertain and may represent either immunologic or direct toxic effects of TMA. In patients with multisystem failure of this nature, occupational hazards should be added to the differential diagnosis.     

Correlstion and prediction of boiling temperatures and azeotropic conditions in multicomponent systems

Thermodynamic models for multicomponent mixtures were derived and tested successfully for correlation of boiling points and for determining the presenc     

Wave-induced oscillations in harbours of variable depth

An integral formulation of the Helmboltz equation is numerically tested on the problem of the wave-induced oscillations in harbours of variable depth. If the method has some disadvantages with respect to the finite element methods, it is rather simple to apply and in some cases it might be preferred. An accurate analysis of all its features and possibilities has not been carried out. A simple application has been considered. The results obtained for this problem show that the volume of the harbour basin, when the bottom is varied, is of primary importance. As the volume decreases, resonance wavenumbers decrease and peak amplitudes increase.     

Studies on clinker calcium silicates bearing CaF2 and CaSO4

The system CaOC₂SCaSO₄CaF₂ was studied at temperatures of 1000°C and 1150°C. The solid state equilibrium relations were determined only partially since liquid phase was present in many samples at the aforesaid temperatures. The system contains only a quaternary compound: the flour-ellestadite 3C₂S.3CaSO₄.CaF₂. The tests carried out lead the authors to think that the two silico-fluorides 2C₂S.CaF₂ and 3C₃S.CaF₂ can form only in the cement raw meals with Fwt%/SO₃wt% ratio > 0.158. Therefore the intermediate compounds which can generally interest the firing process of clinker are the fluor-ellestadite and the calcium silico-sulphate (2C₂S.CaSO₄). Analytical determinations carried out also by microprobe showed that the composition of “3C₃S.CaF₂” better corresponds to the formula 19CaO.7SiO₂.2CaF₂.     

Gadobenate dimeglumine (BOPTA) enhanced MR imaging: patterns of enhancement in normal liver and cirrhosis

To determine whether gadobenate dimeglumine (BOPTA) will adequately enhance cirrhotic liver parenchyma, and to document the enhancement patterns in cirrhosis, 14 cirrhotic and 20 non-cirrhotic patients were evaluated before and 60-120 minutes after gadolinium-BOPTA. Proof of liver cirrhosis was biopsy (6), surgical resection (3), and clinical follow-up (5). Enhancement effects were compared quantitatively by determining the liver signal-to-noise ratio (SNR) and signal enhancement in both populations. Qualitatively assessment of the liver enhancement was performed and classified as homogeneous or heterogeneous. Quantitative analysis: cirrhotic liver parenchyma presented a higher increase in SNR values, relative to non-cirrhotic liver parenchyma, on postcontrast images. Likewise the signal enhancement of cirrhotic liver parenchyma was superior to non-cirrhotic liver on T1-weighted SE images (P = .02) and in-phase GRE images (P < .001). There was no statistical difference on out-of-phase GRE images. Qualitative analysis: on T1-weighted SE postcontrast images, cirrhotic liver parenchyma showed a homogeneous enhancement in 7 patients and heterogeneous in 7. Whereas on GRE images, cirrhotic parenchyma showed heterogeneous enhancement in 9 patients and homogeneous in 5 patients. The heterogeneous enhancement was due to the presence of hypointense nodules in 7 patients and hyperintense nodules in 2 patients. In conclusion, our study has shown that the hepatobiliary contrast agent Gd-BOPTA is effective in the cirrhotic liver, demonstrating an increased liver enhancement compared with non-cirrhotic patients.     

Generalized and/or graphs

A generalization of AND/OR graphs is introduced as a problem solving model, in which subproblem interdependence in problem reduction can be explicitly accounted for. An ordered-search algorithm is given to find a solution. The algorithm is proven to be admissible and optimal. Examples are given which show the application of the formalism to problems which cannot be modelled by AND/OR graphs. Generalized AND/OR graphs are finally shown to be equivalent to type O grammars. Finding a solution of a generalized AND/OR graph is shown to be equivalent to deriving a sentence in the corresponding type O grammar.     

Heats of mixing of amine-alcohol systems. An analytical group solution model approach

Measured heats of mixing for amylamine with n-propanol, n-butanol and n-pentanol at 15°C and 35°C are reported. This experimental information has been used together with other literature heats-of-mixing data on amine-alcohol systems to test the ability of the extended Analytical Croup Solution Model (AGSM) to correlate and predict exothermic heats of mixing. Predictions for amine-alcohol systems, not included in the set of reference systems, are good with the exception of the predictions for systems containing methanol.     

Autothermal reactor with internal heat exchange—II: Numerical and preliminary experimental studies of transient behavior including startup in the multiple steady-state region

A radially-lumped pseudo-homogeneous mathematical simulation representing the dynamic behavior of an autothermal reactor with internal countercurrent h     

Bernardino Ramazzini's early observations of the link between musculoskeletal disorders and ergonomic factors

Bernardino Ramazzini (1633-1714) systematically studied the relationship between work and diseases. He realized that it was not possible to ascribe all workers' diseases to chemicals or physical agents and foresaw that other factors were involved. He observed that common diseases could originate following the maintenance either of prolonged stationary postures or of unnatural postures (e.g. bakers, workers who stand, sedentary worker, scribes, weavers) or following activities requiring heavy muscular performance (e.g. porters and woodworkers). Furthermore, Ramazzini recognized the need to undertake measures to prevent disorders from repetitive motions and manual lifting and anticipated the now accepted advice of moderation and recommendations of reduction of work duration for a number of hard jobs requiring a standing position or severe muscular effort. From his early writings therefore it is evident that Ramazzini realized the importance of assessing the ergonomic factors associated with the occurrence of work-related musculoskeletal disorders.