The invention relates to a process for prepg. a chitosan-contg. microcapsules and emulsions of an oil including the steps of (a) forming an oil-in-water emulsion by homogenizing the oil into an aq. soln. contg. an anionic emulsifier; and (b) adding to the emulsion obtained in (a) an aq. chitosan soln. while continuously homogenizing the mixt. to give a stable emulsion, which is converted into microcapsules by using the proper electrolyte and pH changes. Also encompassed are prepns. including as active ingredient a lice repelling agent, vitamin E or a UV radiation photoprotectant. The prepns. may be sustained-release or long-acting prepns. Rosemary oils were dropwise added into a lecithin soln. in water in a homogenizer to obtain a white emulsion, to which a chitosan soln. (prepd. by dissolving chitosan into a citric acid soln.) was added. The final compn. (pH 3.5) contained rosemary oil 15, chitosan 0.5, citric acid 5, lecithin 0.35, and water 79.15 %. An excellent lice repellency of the emulsion was demonstrated. [on SciFinder(R)]
A method has been developed for the formation of submicron particles (nanoparticles) by heat-denaturation of proteins (such as human serum albumin) in the presence of multivalent ions (such as calcium). Also provided are novel products produced by the invention method. An appropriate concn. of multivalent ions, within a relatively narrow range of concns., induces the pptn. of protein in the form of colloidal particles, at a temp. which is well below the heat denaturation temp. of the protein (as low as 60 °C for serum albumin). Temps. at which invention method operates are sufficiently low to permit incorporation of other mols. (e.g., by co-pptn.), into submicron particles according to the invention, including compds. which cannot withstand high temps. Invention methods facilitate the prodn. of protein nanoparticles and microparticles contg. various mols. (such as nucleic acids, oligonucleotides, polynucleotides, DNA, RNA, polysaccharides, ribozymes, pharmacol. active compds., and the like) useful for therapeutic, diagnostic and other purposes. The addn. of multivalent cations serves both to induce pptn., and to allow linking of neg. charged mols., such as DNA, to the neg. charged protein. Microparticles and nanoparticles were formed from albumin in the presence of CaCL2. [on SciFinder(R)]
The probability of an error in a Monte Carlo integration is shown to be exponentially small in the number of points used, with the magnitude of the exponent being determined by a relevant entropy. Implications for importance sampling and for the significance of the maximum entropy formalism an discussed. Specifically it is shown that the optimal sampling distribution is one of maximal entropy. The Monte Cal-lo method or its variants play an essential role in classical trajectory computations. Practitioners are aware that generating few trajectories is already sufficient for typical quantities such as the mean energy of the products to settle down to the correct value. The present results provide further insight and suggest why a distribution of maximal entropy can provide such useful representation of the results. The discussion is based on the information theoretic bound for the error of transmission and can also be derived from the Chernoff bound in hypothesis testing. (C) 1998 Elsevier Science B.V.
The paper criticizes standard functionalist arguments for multiple realization. It focuses on arguments in which psychological states are conceived as computational, which is precisely where the multiple realization doctrine has seemed the strongest. It is argued that a type-type identity thesis between computational states and physical states is no less plausible than a multiple realization thesis. The paper also presents, more tentatively, positive arguments for a picture of local reduction.
Disorder is shown to induce qualitative changes in the electronic spectrum and hence in the response of assemblies of quantum dots. Lattices of quantum dots have one unique source of disorder: the dots themselves can be prepared with a narrow distribution of properties but they are never quite identical. This is unlike a lattice of atoms or molecules. In addition, lattices of quantum dots have a configurational disorder and can also be prepared with compositional disorder. The relaxation of selection rules and the splittings of degeneracies due to symmetry breaking induced by these fluctuations can be probed by optical means. Special attention is given to the enhancement and to the variation of the second harmonic response as a function of the spacing between the dots.
We report the first observation of spatial one-dimensional photorefractive screening solitons in centrosymmetric media and compare the experimental results with recent theoretical predictions. We find good qualitative agreement with theory. (C) 1998 Optical Society of America.
Lay summary:
This review of Alon Peled's "A Question of Loyalty: Military Manpower Policy in Multiethnic States" praises Peled's crisp, skillful investigation of three countries' (South Africa, Singapore, and Israel)'s attempts to forge separate, antagonistic ethnic groups into effective military organizations. The primary concern, in such cases, is that a militarily trained ethnic group will revolt against the state. The book finds that military professionalism is key to creating a unified military force.
Publication significance:
Creating a united military force from citizens of diverse ethnic identities is a pressing issue in numerous nation states. A unified military is crucial to ensure the longevity and security of a state's regime. Peled's book tackles this issue and provides findings with important practical implications: professionalism is key to creating a unified, efficient military organization.
The mechanisms of cellular damage caused by infectious and inflammatory processes are complex and are still not fully understood. There is, however, a consensus that reactive oxygen species (ROS) generated by phagocytes migrating to injured tissues might be the main agents responsible for cellular damage in inflammatory processes. However, because both activated phagocytes and catalase-negative, peroxide-producing, toxigenic bacteria (Streptococci, Clostridiae) secrete a near-identical array of proinflammatory agonists, including reactive oxygen species (ROS), and because these microbial species might kill their targets by a synergism among several of their secreted enzymes (a multicomponent system), we postulated that activated phagocytes might also function in the same way. Using radiolabeled targets, in culture, we demonstrated that subtoxic amounts of a variety of oxidants (H2O2, radicals produced by xanthine-xanthine-oxidase, peroxyl radical, NO) acted synergistically with subtoxic amounts of a large series of membrane-perforating agents (microbial hemolysins, phospholipases, fatty acids, cationic proteins, proteinases, bile salts, the attack complex of complement, the xenobiotics, lindane, ethanol, methanol) to kill cells in culture and to release large amounts of arachidonic acid and metabolites. Membrane perforators might act primarily to overcome the potent antioxidant systems present in all mammalian cells and scavengers of ROS and inhibitors of the additional agonists might act to abolish the synergism among ROS and the membrane-damaging agents. It is also proposed that protection against tissue damage in vivo should also include 'cocktails' of appropriate antagonists. It is enigmatic that those publications which do describe both in-vitro and in-vivo models proposing that a synergism among a multiplicity of agonists might truly represent the mechanisms by which tissues are injured, in vivo, are hardly ever quoted in the current literature.
Electric-field multiplexing (EFM) results from the tuning of the effective wavelength of the light beam inside a photorefractive crystal. This tuning results from the application of an external electric field to the crystal during holographic recording. We demonstrate the high Bragg selectivity of this multiplexing technique in paraelectric crystals and compare it with the selectivity obtained in the ferroelectric phase. The effects of the two major physical parameters of working in the paraelectric phase, the temperature and the external electric field applied during the writing stage, are investigated. Experimental results of the EFM of three image-bearing holograms recorded in reflection geometry are presented along with a qualitative analysis of the Bragg selectivity in paraelectric crystals.
An in vitro model was employed to study the potential role of streptococcal extra-cellular products, rich in streptolysin O, in cellular injury as related to streptococcal infections and post-streptococcal sequelae. Extra-cellular products (EXPA) rich in streptolysin O were isolated from type 4, group A hemolytic streptococci grown in a chemostat, in a synthetic medium. EXPA induced moderate cytopathogenic changes in monkey kidney epithelial cells and in rat heart cells pre-labeled with 3H-arachidonate. However very strong toxic effects were induced when EXP was combined with oxidants (glucose oxides generated H2O2, AAPH-induced peroxyl radical (ROO.), NO generated by sodium nitroprusside) and proteinases (plasmin, trypsin). Cell killing was distinctly synergistic in nature. Cell damage induced by the multi-component cocktails was strongly inhibited either by micromolar amounts of gamma globulin, and Evan's blue which neutralized SLO activity, by tetracycline, trasylol (aprotinin), epsilon amino caproic acid and by soybean trypsin inhibitor, all proteinase inhibitors as well as by a non-penetrating PLA2 inhibitor A. The results suggest that fasciitis, myositis and sepsis resulting from infections with hemolytic streptococci might be caused by a coordinated 'cross-talk' among microbial, leukocyte and additional host-derived pro-inflammatory agents. Since attempts to prolong lives of septic patients by the exclusive administration of single antagonists invariably failed, it is proposed that the administration of 'cocktails' of putative inhibitors against major pro-inflammatory agonizes generated in inflammation and infection might protect against the deleterious effects caused by the biochemical and pharmacological cascades which are known to be activated in sepsis.
From Philo's religious perspective, paganism had a mistaken esteem for human fabrications and fancies. He maintained a firm boundary between pagan myth and Jewish scripture, a distinction based on his own intuition and on his appreciation of Plato. His criticism of pagan myth reflects Platonic arguments, which he sharpened with a view to stressing characteristic shortcomings of Hellenistic culture and contrasting them to Judaism. Ironically, Philo appropriated pagan hermeneutics and philosophy in order to maintain and redefine the boundary between Judaism and paganism.
