The identity of psychoanalysis and psychoanalysts.

Psychoanalysis has been in a constant uninterrupted debate about its identity as a discipline and as a social institution. This article considers the place of science in psychoanalysis, on the one hand, and the hermeneutic nature of our discipline, on the other. The aim is to articulate a typology of psychoanalytic knowledge that characterizes psychoanalysis as a form of therapy, an intellectual movement, and a theoretical system. This typology considers psychoanalysis as a thought collective that influences its members by exchanging and maintaining ideas. To be a well-rounded psychoanalytic thinker or practitioner one must be able to move easily among three realms of knowledge--the humanities, the social sciences, and the natural sciences. Each realm has its own criteria of truth and the challenge is to know when to employ which criteria. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Metabolism of lysophosphatidylcholine by swine platelets

Incubation of intact platelets from Sinclair(S-1) miniature swine with³²P-labeled lysophosphatidylcholine (lyso PC) indicated the presence of an active lysophospholipase with a pH optimum of 8.0 for hydrolysis of the substrate. However, lyso PC was incorporated into the membrane phosphatidylcholines by the acyltransferase pathway upon addition of ATP, Mg⁺⁺ and CoA to the platelet suspension. These results suggest that intact platelets are able to resist the cytotoxic effects of lyso PC in plasma, and the phospholipids in platelet membranes are not readily affected by the lipid environment of the plasma. The acyltransfer reaction apparently is saturated with endogenous free fatty acids since arachidonic acid added exogenously did not further enhance the incorporation activity. Neither the acyltransferase nor the lysophospholipase activity was affected by Ca⁺⁺, but divalent metal ions such as Zn⁺⁺ inhibited the lysophospholipase activity. Cholesterol but not cholesteryl esters elicited a biphasic effect on both enzymes, stimulating at low concentration but inhibiting at a cholesterol to lyso PC ratio greater than 1. Serum albumin inhibited the lysophospholipase but gave a small biphasic effect to the acyltransferase.     

Development of Biarylalkyl Carboxylic Acid Amides with Improved Anti-schistosomal Activity

The parasitic disease schistosomiasis is the cause of more than 200 000 human deaths per year. Although the disease is treatable, there is one major shortcoming: praziquantel has been the only drug used to combat these parasites since 1977. The risk of the emergence of resistant schistosomes is known to be increasing, as a reduced sensitivity of these parasites toward praziquantel has been observed. We developed a new class of substances, which are derived from inhibitors of human aldose reductase, and which showed promising activity against Schistosoma mansoni couples in vitro. Further optimisation of the compounds led to an increase in anti-schistosomal activity with observed phenotypes such as reduced egg production, vitality, and motility as well as tegumental damage and gut dilatation. Here, we performed structure–activity relationship studies on the carboxylic acid moiety of biarylalkyl carboxylic acids. Out of 82 carboxylic acid amides, we identified 10 compounds that are active against S. mansoni at 25 μm . The best five compounds showed an anti-schistosomal activity up to 10 μm and induced severe phenotypes. Cytotoxicity tests in human cell lines showed that two derivatives had no cytotoxicity at 50 or 100 μm . These compounds are promising candidates for further optimisation toward the new anti-schistosomal agents.     

The development of a silica nanoparticle-based label-free DNA biosensor

A silica nanoparticle-based DNA biosensor capable of detecting Bacillus anthracis bacteria through the use of unlabelled ss-oligonucleotides has been developed. The biosensor makes use of the optical changes that accompany a nanoparticle-immobilized cationic conjugated polymer (polythiophene) interacting with single-stranded vs. hybridized oligonucleotides, where a fluorescence signal appears only when hybridized DNA is present (i.e. only when the ss-oligonucleotide interacting with the polymer has hybridized with its complement). In order to enhance the sensitivity of the biosensor, two different nanoparticle architectures were developed and used to elucidate how the presence of neighboring fluorophores on the nanoparticle surface affects F?rster-resonant energy transfer (FRET) between the polythiophene/oligonucleotide complex (FRET donor) and the fluorophores (FRET acceptors). We demonstrate that the silica nanoparticle-based FRET platform lowers the limit of detection at least 10-fold in comparison to the polythiophene itself, and allows the detection of ～2 × 10(-12) moles of ss-oligonucleotide in a 100 μL sample with a standard fluorimeter (i.e. has a limit of detection of ～2 nM ssDNA). Such nanoparticle-based biosensor platforms are beneficial because of the robustness and stability inherent to their covalent assembly and they provide a valuable new tool that may allow for the sensitive, label-free detection (the target DNA that produces the fluorescence signal is unlabelled) without the use of polymerase chain reaction.     

Effect of chain rigidity on block copolymer micelle formation and dissolution as observed by 1H-NMR spectroscopy

Amphiphilic copolymers poly(methyl methacrylate-b-acrylic acid), poly(methyl methacrylate-b-methacrylic acid), poly(methyl acrylate-b-acrylic acid) and poly(methyl acrylate-b-methacrylic acid) were prepared by reversible addition fragmentation chain-transfer (RAFT) polymerization. The hydrophilic polyacid blocks were either synthesized directly or formed by the hydrolysis of poly(tert-butyl acrylate) or poly(tert-butyl methacrylate) blocks. The hydrophobic blocks consisted of either the more rigid, high glass transition temperature (T _g ) poly(methyl methacrylate) or more flexible, low T _g poly(methyl acrylate) material. The hydrophilic blocks were either poly(methacrylic acid) (rigid, high T _g ) or poly(acrylic acid) (flexible, low T _g ). The micellization behavior of the polymers was studied by proton nuclear magnetic resonance (¹H-NMR) spectroscopy in mixtures of 1,4-dioxane-d₈ and D₂O. All four polymers were soluble in neat dioxane. In solutions of higher water content, the polymers with the more rigid hydrophobic blocks formed into micelles as was evidenced by broadening of the resonances resulting from the protons in those blocks. At moderate water concentration (25–50%), dissolution of the micelles was observed upon heating the solution. No micellization was observed in polymers containing the less rigid poly(methyl acrylate) hydrophobic block regardless of the identity of the hydrophilic block. As further evidence of micellization formation and dissolution, the spin-lattice (T ₁) and spin-spin (T ₂) relaxation times of protons in the hydrophobic and hydrophilic blocks were measured. Significant differences in the relaxation times as functions of temperature and solvent concentration were observed between the hydrophilic and hydrophobic blocks of the micelle-forming polymers.     

Microstructure of the HMX‐Based PBX KS32 after Mechanical Loading

Non‐destructive X‐ray diffraction techniques were applied in order to monitor the influence of mechanical and shock‐loading on the microstructure of the plastic‐bonded high explosive KS32. The investigations uncovered damage to embedded coarse HMX crystals and to the binder system HTPB‐IPDI. Damage to the crystals occurred already during the kneading process in terms of deformation twinning. On higher loading between 400 MPa (static) and 480 MPa (dynamic) also crystal fracture was observed. The change in the binder structure was found after both static and dynamic loading, but not in the cured, differently kneaded samples. Moreover, the change in binder structure after dynamic loading was verified by dynamic mechanical analysis, and interpreted as a partial damage of the binder rubber shell around the explosive particles. The results are compared to literature data from imaging techniques.     

Funktionspolymere-ein interdisziplinäres forschungsgebiet-

Functional polymers differ from structural polymers in various aspects. The most evident difference is their lack of visibility as they are mostly empolyed in surface applications, e.g. as crystal growth modifiers to inhibit encrustation in detergents, as hair setting agents, or as electro-conductive films. Additional important differences concerning the motivation for new developments, market aspects, and customer relationships are the subject of this paper. The development of technology and market competence in the field of functional polymers and the special problems of low-volume, high-performance chemicals are discussed in detail. The paper deals with examples of recent developments: Polyaramides for membranes, 3,4-polyethylenedioxythiophene as an electroconductive polymer, polyaspartic acid as a biodegradable polycarboxylate in detergents, highly crosslinked, insoluble vinylpyrrolidone/vinylimidazole copolymers for the removal of heavy metals from wine, and finally an insoluble, crosslinked polyvinylpyrrolidone-iodine complex for the sterile filtration of liquids. The outlook discusses the research challenges which remain before a full understanding of the structure/property relationships can be attained.     

Synthesis of magnetic nanocomposite microparticles for binding of chlorinated organics in contaminated water sources

In this work, the development of novel magnetic nanocomposite microparticles (MNMs) via free radical polymerization for their application in the remediation of contaminated water is presented. Acrylated plant-based polyphenols, curcumin multiacrylate (CMA) and quercetin multiacrylate (QMA), were incorporated as functional monomers to create high affinity binding sites for the capture of polychlorinated biphenyls (PCBs), as a model pollutant. The MNMs were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, dynamic light scattering, and UV–visible spectroscopy. The affinity of these novel materials for PCB 126 was evaluated and fitted to the nonlinear Langmuir model to determine binding affinities (K_D). The results suggest the presence of the polyphenolic moieties enhances the binding affinity for PCB 126, with K_D values comparable to that of antibodies. This demonstrates that these nanocomposite materials have promising potential as environmental remediation adsorbents for harmful contaminants.     

Cloning and heterologous expression of three type II PKS gene clusters from Streptomyces bottropensis

Mensacarcin is a potent cytotoxic agent isolated from Streptomyces bottropensis. It possesses a high content of oxygen atoms and two epoxide groups, and shows cytostatic and cytotoxic activity comparable to that of doxorubicin, a widely used drug for antitumor therapy. Another natural compound, rishirilide A, was also isolated from the fermentation broth of S. bottropensis. Screening a cosmid library of S. bottropensis with minimal PKS-gene-specific primers revealed the presence of three different type II polyketide synthase (PKS) gene clusters in this strain: the msn cluster (mensacarcin biosynthesis), the rsl cluster (rishirilide biosynthesis), and the mec cluster (putative spore pigment biosynthesis). Interestingly, luciferase-like oxygenases, which are very rare in Streptomyces species, are enriched in both the msn cluster and the rsl cluster. Three cosmids, cos2 (containing the major part of the msn cluster), cos3 (harboring the mec cluster), and cos4 (spanning probably the whole rsl cluster) were introduced into the general heterologous host Streptomyces albus by intergeneric conjugation. Expression of cos2 and cos4 in S. albus led to the production of didesmethylmensacarcin (DDMM, a precursor of mensacarcin) and the production of rishirilide A and B (a precursor of rishirilide A), respectively. However, no product was detected from the expression of cos3. In addition, based on the results of isotope-feeding experiments in S. bottropensis, a putative biosynthesis pathway for mensacarcin is proposed.     

A molecular dynamics simulation of bacteriophage T4 lysozyme

An analysis of a 400 ps molecular dynamics simulation of the164 amino acid enzyme T4 lysozyme is presented. The simulationwas carried out with all hydrogen atoms modeled explicitly,the inclusion of all 152 crystallographic waters and at a temperatureof 300 K. Temporal analysis of the trajectory versus energy,hydrogen bond stability, r.m.s. deviation from the startingcrystal structure and radius of gyration, demonstrates thatthe simulation was both stable and representative of the averageexperimental structure. Average structural properties were calculatedfrom the enzyme trajectory and compared with the crystal structure.The mean value of the C displacements of the average simulatedstructure from the X-ray structure was 1.1 ± 0.1 Å;differences of the backbone and angles between the averagesimulated structure and the crystal structure were also examined.Thermal-B factors were calculated from the simulation for heavyand backbone atoms and both were in good agreement with experimentalvalues. Relationships between protein secondary structure elementsand internal motions were studied by examining the positionalfluctuations of individual helix, sheet and turn structures.The structural integrity in the secondary structure units waspreserved throughout the simulation; however, the A helix didshow some unusually high atomic fluctuations. The largest backboneatom r.m.s. fluctuations were found in non-secondary structureregions; similar results were observed for r.m.s. fluctuationsof non-secondary structure and angles. In general, the calculatedvalues of r.m.s. fluctuations were quite small for the secondarystructure elements. In contrast, surface loops and turns exhibitedmuch larger values, being able to sample larger regions of conformationalspace. The C difference distance matrix and super-positioninganalyses comparing the X-ray structure with the average dynamicsstructure suggest that a ‘hinge-bending’ motionoccurs between the N- and C-terminal domains.