Suppression of floatability of pyrite in coal processing by carrier microencapsulation

Carrier microencapsulation, CME, is a technique to form a thin layer of metal oxide or hydroxide on pyrite surface using a water soluble organic carrier combined with metal ions. The present study investigated the effect of CME using a tris-catecholato complex of Si⁴⁺, Si(cat)₃²⁻ on pyrite-coal separation by dynamic bubble pick-up experiments and Hallimond tube flotation experiments using coal, pyrite, and a coal-pyrite mixture. The mineral samples were treated in 0-5 mol m^− 3 Si(cat)₃²⁻ solutions at pH 4-9 at treatment times of 1-24 h. Dynamic bubble pick-up experiments showed that CME treatment converted the pyrite surface from hydrophobic to hydrophilic but did not affect coal's hydrophobic surface. The results of the Hallimond tube flotation experiments of a coal-pyrite mixture at pH 7-9 in the presence of kerosene as a collector showed that pyrite floatability was selectively suppressed after 1 h CME treatment with 0.5 mol^− 3 Si(cat)₃²⁻ while both coal and pyrite were floated without the treatment. This indicates that CME treatment is effective in suppressing pyrite floatability in coal-pyrite flotation.     

Angiotensin I-converting enzyme inhibitory activities of Chinese fermented soypaste and estimation of the inhibitory substances

Angiotensin I-converting enzyme (ACE) inhibitory activities of aqueous extracts of Chinese commercial soypaste were investigated in this work. Six samples from northern China showed potent ACE inhibitory activities with IC₅₀ values less than 40.0 μg/mL. ACE inhibitors in the sample with the strongest activity were purified by ultrafiltration, solid-phase extraction and gradient RP-HPLC. According to spectroscopic methods, a compound (M328.1) was separated as C₁₅H₂₁NO₇. It was supposed to be a conjugate of phenylalanine and glucose generated by Maillard reaction during soypaste production, providing support on the contribution of Maillard reaction products to the ACE inhibitory activity of the sample. Results further indicated that the total ACE inhibition by the sample occurred from the combined function of various bioactive substances, suggesting that Chinese soypaste could be a good source of ACE inhibitors for exploring functional foods or ingredients with antihypertensive effect.     

Rate of change of oxygen chemical potential in liquid PbO−SiO2 binary solution

The rate of the chemical potential change of oxygen in a liquid PbO?SiO₂ binary solution, with SiO₂ contents of 10, 20, and 30 mol pct, and in pure PbO, has been measured at temperatures of 900°, 950°, 1000°, 1050°, and 1100°C. The rate increased with temperature according to the Arrhenius type relation and decreased with the increase of the silica content. It is suggested that the rate-controlling step is the counter diffusion rate of Pb²⁺ and Pb⁴⁺ ions, which are considered to be the most easily movable ions in the PbO?SiO₂ solution. The relation between the rate of oxygen chemical potential change and the electrical conductivity is also discussed for the liquid PbO?SiO₂ system.     

Immunological studies of SK2 hybridoma cells microencapsulated with alginate-poly(L)lysine-alginate (APA) membrane following allogeneic transplantation

Microencapsulation of living cells or tissues has been proposed to prevent their immune destruction following transplantation. In this study, we examined whether SK2 hybridoma cells microencapsulated in an alginate-poly(L)lysine-alginate (APA) membrane (APA-SK2 cells) were immunoisolated from the allogeneic host's immune system using a cytotoxicity test. The APA membrane inhibited the activation of the host's cellular immune response, but did not prevent the production of cytotoxic antibodies against entrapped SK2 cells following allogeneic transplantation. However, the APA-SK2 cells remained vital in SK2 cell-immunized mice as well as in intact mice. We considered that complement regulatory factors which were present on cell membrane and had species-specific restriction blocked the complement-mediated cell lysis on allogeneic transplantation, since APA-SK2 cells were destroyed by rabbit anti-SK2 cell antiserum. Our results demonstrated that APA membrane could inhibit cell-cell contact between entrapped cells and the host's lymphocytes, but could not completely protect the entrapped cells from xenogeneic humoral immunity.     

Lindeman's melting law and solidus curve under pressure of Al–Si and Al–Ge solid solutions

Using the pressure dependence of the mean-square displacement, the compression effect on the melting temperature of matrix Al is studied by Lindeman's melting law. The melting curve obtained increases as a function of the pressure and is in good agreement with the observed tendency for Al. The contribution of the transverse-like acoustic modes to the mean-square displacement is important for Al and becomes more predominant under pressure. Then, considering the contributions from the band and local mode frequencies, the temperature- and pressure-dependent mean-square displacement is quantitatively calculated for Al–Si and Al–Ge solid solutions. The concentration dependence of the Debye temperature at high and low temperatures is estimated, and the pressure effect on the solidus curves is presented by applying Lindeman's melting law to the Al–Si and Al–Ge alloy systems. © 1998 Chapman & Hall     

Clinical assessment of complement activation and leukocyte kinetics during cardiopulmonary bypass: the effect of cepharanthine

Complement activation and leukosequestration to the lung was studied during cardiopulmonary bypass in eleven patients undergoing cardiac operation without blood transfusion. Six patients (group I) received methylprednisolone before and after the bypass, and the other five (group II) received cepharanthine (biscoclaurin alkaloid) before the bypass associated with methylprednisolone therapy. Leukosequestration to the lung was observed at the time of reperfusion of the lung only in group I, although complement activation estimated by the increase of C 4 a and C 3 a was quite similar in both group. Cepharanthine prevented the sequestration of the leukocyte to the lung may be by its membrane stabilizing effect.     

Zonal heterogeneity of hepatic injury following shock/resuscitation: relationship of xanthine oxidase activity to localization of neutrophil accumulation and central lobular necrosis

Post-ischemic hepatic injury is characterized by zonal heterogeneity of injury (central lobular necrosis), sinusoidal neutrophil accumulation, and injury generated by reactive oxygen metabolites. We evaluated the role of the heterogeneous distribution of hepatic xanthine oxidase in the generation of neutrophil accumulation and consequent hepatocellular injury in rats subjected to shock [controlled hemorrhagic hypotension (mean arterial pressure = 37.5 + or - 2.5 mmHg for 120 min)], with or without subsequent resuscitation and hemodynamic stabilization, compared with sham-operated rats. Shock/resuscitation produced striking neutrophil accumulation (assayed by esterase histochemistry) in the pericentral sinusoids, associated with centrolobular necrosis. This paralleled the pericentral distribution of xanthine oxidase (determined by histochemical assay of frozen sections) and its release from the liver into the circulation at resuscitation. Pretreatment with allopurinol inhibited hepatic xanthine oxidase activity, neutrophil accumulation, and pericentral hepatocyte necrosis in shock/resuscitation in rats. These findings suggest that reactive oxygen metabolites generated by heterogeneously distributed xanthine oxidase may contribute to the heterogeneity of hepatocellular injury in "ischemic hepatitis."     

Synthesis of active sites for alkene metathesis reaction on molybdenum oxide films by the reaction with alkylidene radicals

A super active catalyst (T.F. = 0.2 0.3) for alkene metathesis reaction was prepared by coordinating CH₂ radicals onto sublimed molybdenum oxide films, where the radicals were prepared by the reaction of CH₂I₂ with Al or Mg metals deposited near the oxide film.The authors are indebted to the Iwatani Naoji Foundation and the Murata Science Foundation for the support of this work.     

Multi-scale integrated analysis of societal and ecosystem metabolism (MuSIASEM): Theoretical concepts and basic rationale

The multi-scale integrated analysis of societal and ecosystem metabolism (MuSIASEM) approach makes it possible to perform a check on the feasibility and desirability of patterns of metabolism of socio-economic systems by providing a characterization at different levels and scales of: (a) the performance of socio-economic activities (for households, enterprises, economic sectors, national economies, world economy) and (b) ecological constraints (micro, meso, macro) by looking at the interference that the metabolism of matter and energy flows controlled by human activity induces on the expected pattern of metabolism of matter and energy flows associated with the self-organization of natural ecosystems. This paper presents three theoretical concepts behind the analytical approach MuSIASEM: (1) how to represent the endosomatic and exosomatic metabolism of societies using Georgescu-Roegen's flow–fund scheme; (2) how to generate a Sudoku effect across representations of different units of production and consumption defined at different levels; and (3) how to perform an impredicative loop analysis when dealing with changes (evolution) of the characteristics of dynamic budgets of metabolized flows, represented across different scales. Since sustainability deals with “becoming systems”—systems becoming something else in their process of evolution—an analysis of sustainability must adopt analytical tools semantically open in their representation of change. MuSIASEM can do that since it is a “multi-purpose grammar”, which can be used for building a shared perception and representation of this “becoming” when studying sustainability. That is, it entails an agreement on an expected set of relations between “relevant semantic categories” and “pertinent formal categories” across hierarchical levels and across different narratives; for this reason it represents a clear discontinuity from models developed within the paradigm of reductionism to deal with the issue of sustainability.