Self-assembly and bioactivity of a polymer/peptide conjugate containing the RGD cell adhesion motif and PEG

The self-assembly and bioactivity of the peptide–polymer conjugate DGRFFF–PEG3000 containing the RGD cell adhesion motif has been examined, in aqueous solution. The conjugate is designed to be amphiphilic by incorporation of three hydrophobic phenylalanine residues as well as the RGD unit and a short poly(ethylene glycol) (PEG) chain of molar mass 3000 kg mol-1. Above a critical aggregation concentration, determined by fluorescence measurements, signals of b-sheet structure are revealed by spectroscopic measurements, as well as X-ray diffraction. At high concentration, a self-assembled fibril nanostructure is revealed by electron microscopy. The fibrils are observed despite PEG crystallization which occurs on drying. This suggests that DGRFFF has an aggregation tendency that is sufficiently strong not to be prevented by PEG crystallization. The adhesion, viability and proliferation of human corneal fibroblasts was examined for films of the conjugate on tissue culture plates (TCPs) as well as low attachment plates. On TCP, DGRFFF–PEG3000 films prepared at sufficiently low concentration are viable, and cell proliferation is observed. However, on low attachment surfaces, neither cell adhesion nor proliferation was observed, indicating that the RGD motif was not available to enhance cell adhesion. This was ascribed to the core–shell architecture of the self-assembled fibrils with a peptide core surrounded by a PEG shell which hinders access to the RGD unit.

A self-assembling fluorescent dipeptide conjugate for cell labelling

Derivatives of fluorophore FITC (fluorescein isothiocyanate) are widely used in bioassays to label proteins and cells. An N-terminal leucine dipeptide is attached to FITC, and we show that this simple conjugate molecule is cytocompatible and is uptaken by cells (human dermal and corneal fibroblasts) in contrast to FITC itself. Co-localisation shows that FITC-LL segregates in peri-nuclear and intracellular vesicle regions. Above a critical aggregation concentration, the conjugate is shown to self-assemble into beta-sheet nanostructures comprising molecular bilayers.

Self-immolative base-mediated conjugate release from triazolylmethylcarbamates

A range of carbamate functionalized 1,4-disubstituted triazoles featuring a base sensitive trigger residue, plus a model aromatic amine reporter group, were prepared via copper(I) catalysed azide–alkyne cycloaddition and evaluated for their self-immolative characteristics. This study revealed a clear structure–reactivity relationship, via Hammett analysis, between the structure of the 1,4-disubstituted triazole and the rate of self-immolative release of the amine reporter group, thus demonstrating that under basic conditions this type of triazole derivative has the potential to be employed in a range of chemical release systems.

Self-assembly of telechelic tyrosine end-capped PEO and poly(alanine) polymers in aqueous solution

The self-assembly in aqueous solution of three novel telechelic conjugates comprising a central hydrophilic polymer and short (trimeric or pentameric) tyrosine end-caps has been investigated. Two of the conjugates have a central poly(oxyethylene) (polyethylene oxide, PEO) central block with different molar masses. The other conjugate has a central poly(l-alanine) (PAla) sequence in a purely amino-acid based conjugate. All three conjugates self-assemble into β-sheet based fibrillar structures, although the fibrillar morphology revealed by cryogenic-TEM is distinct for the three polymers—in particular the Tyr5-PEO6k-Tyr5 forms a population of short straight fibrils in contrast to the more diffuse fibril aggregates observed for Tyr5-PEO2k-Tyr5 and Tyr3-PAla-Tyr3. Hydrogel formation was not observed for these samples (in contrast to prior work on related systems) up to quite high concentrations, showing that it is possible to prepare solutions of peptide–polymer-peptide conjugates with hydrophobic end-caps without conformational constraints associated with hydrogelation. The Tyr5-PEO6k-Tyr5 shows significant PEO crystallization upon drying in contrast to the Tyr5-PEO2k-Tyr5 conjugate. Our findings point to the remarkable ability of short hydrophobic peptide end groups to modulate the self-assembly properties of polymers in solution in model peptide-capped “associative polymers”. Retention of fluidity at high conjugate concentration may be valuable in potential future applications of these conjugates as bioresponsive or biocompatible materials, for example exploiting the enzyme-responsiveness of the tyrosine end-groups

A FOSSIL BULGE GLOBULAR CLUSTER REVEALED BY VERY LARGE TELESCOPE MULTI-CONJUGATE ADAPTIVE OPTICS

The globular cluster HP 1 is projected on the bulge, very close to the Galactic center. The Multi-Conjugate Adaptive Optics Demonstrator on the Very Large Telescope allowed us to acquire high-resolution deep images that, combined with first epoch New Technology Telescope data, enabled us to derive accurate proper motions. The cluster and bulge fields` stellar contents were disentangled through this process and produced an unprecedented definition in color-magnitude diagrams of this cluster. The metallicity of [Fe/H] approximate to -1.0 from previous spectroscopic analysis is confirmed, which together with an extended blue horizontal branch imply an age older than the halo average. Orbit reconstruction results suggest that HP 1 is spatially confined within the bulge.

Multi-Conjugate Adaptive Optics VLT imaging of the distant old open cluster FSR 1415

We employ the recently installed near-infrared Multi-Conjugate Adaptive Optics demonstrator (MAD) to determine the basic properties of a newly identified, old and distant, Galactic open cluster (FSR 1415). The MAD facility remarkably approaches the diffraction limit, reaching a resolution of 0.07 arcsec (in K), that is also uniform in a field of similar to 1.8 arcmin in diameter. The MAD facility provides photometry that is 50 per cent complete at K similar to 19. This corresponds to about 2.5 mag below the cluster main-sequence turn-off. This high-quality data set allows us to derive an accurate heliocentric distance of 8.6 kpc, a metallicity close to solar and an age of similar to 2.5 Gyr. On the other hand, the deepness of the data allows us to reconstruct (completeness-corrected) mass functions (MFs) indicating a relatively massive cluster, with a flat core MF. The Very Large Telescope/MAD capabilities will therefore provide fundamental data for identifying/analysing other faint and distant open clusters in the Galaxy III and IV quadrants.

COMPARISON RESULTS FOR CONJUGATE AND FOCAL POINTS IN SEMI-RIEMANNIAN GEOMETRY VIA MASLOV INDEX

We prove an estimate on the difference of Maslov indices relative to the choice of two distinct reference Lagrangians of a continuous path in the Lagrangian Grassmannian of a symplectic space. We discuss some applications to the study of conjugate and focal points along a geodesic in a semi-Riemannian manifold.

Redução de danos e o saber-fazer de profissionais de um CAPS ad em Natal-RN

The present study had as a main objective to analyze how the professionals at a CAPS ad unit in Natal-RN conceive the knowledge-practice process with regard to the Harm Reduction Policy (HRP) towards alcohol and other drugs. For the accomplishment of this proposal, it was intended: 1) Verifying the possibilities and limits of the HRP implementation at a CAPS ad unit in Natal-RN; 2) Relating the professionals knowledge at a CAPS ad unit in Natal in regard to the Harm Reduction Policy; 3) Enumerating the HRP programmatic actions at the institution. The research had exploratory, descriptive and qualitative approach aspects, guided by the concepts of biopower and self care proposed by Michel Foucault. Data collection occurred in June and July 2011, in which the focal group technique was used. After that, collect field material was analyzed through the content analysis method proposed by Minayo. The results showed some conceptual and practical approach between the harm reduction strategy and the knowledge-practice of the professionals at this CAPS ad unit. The discursive models about drug usage, especially the moral-legal model, still have a significant role in the daily lives of these professionals, being amplified by some demands of their jobs or even through the instituted discourse. The individuals recognize the need for less prohibited practices and more socializing ones, identifying them with the Harm Reduction (HR) logic, when there is a coherent and well-founded understanding about HR among the professionals. Distorted and reductionist views about HR as considering the simple instrumental function of this strategy (distribution of basic supplies) among the professionals, represent one of the main barriers for its implementation. There are few programmatic activities that are related to the RD strategy at this CAPS ad unit which makes a more effective appropriation by the working team difficult to reach. The working processes and the postures adopted by this CAP ad unit professionals have been showing that many of their practices and conceptions were modified to the detriment of new necessities emerged from the demands. Consequently, the self care notion is revealed which brings the need for the valorization of these care agents roles, that is, their collective and individual contribution.

Conquistas e desafios do processo de trabalho de enfermagem: o caso dos CAPS em Natal/RN

The Brazilian Psychiatric Reform proposes creating linkages / interactions of the mentally ill with civil society , through promoting citizenship and assistance to the mentally ill. The deinstitutionalization of mental health advocates from the guidelines decreased supply of hospital beds and consequently the creation of substitute services for psychosocial care, especially with regard to therapeutic practices emancipatory. From this scenario, the present study aims to investigate the relevance and challenges of the process of nursing work in CAPS III in Natal / RN. It is descriptive research with a qualitative and exploratory. The subjects are employees of the nursing team in CAPS III East of Natal / RN. This service has actions for the psychosocial care of the subjects treated with daily multidisciplinary care by behaving the length of treatment and follow-up activities, industrial and cultural activities. Employ the semi-structured interview as a tool for data collection. The data analysis was done by means of thematic analysis proposed by Bardin. Thus, this sought to bring to the discussion of how this process is consolidated in the daily service. Thus, purposed to contribute to the debate on deinstitutionalization in psychosocial care as a guideline in the process of mental health nursing work in a CAPSIII, Natal / RN

Análise do modelo de gestão implantado no Centro de Atenção Psicossocial CAPS II OESTE de 1995 a 2005, situado no distrito sanitário Oeste do município de Natal/RN, à luz da Co-gestão

This dissertation has as aim the praxis of co-management of the health service of CAPS II OESTE of Natal-RN, where health workers, family members got to materialize guidelines and principles of psychiatric Brazilian reform in real possibilities of subjectivity construction, whereas they changed social relations in daily life. The path chosen to record was from testimonials and contributions of those who meant their done. Redeeming this story from social representations of the majority of their builders was an instigating, delicate and rewarding task, emphasizing the living memory, rebuilt in a line of time which could not be found in simple documentary collections. Mainly, by knowing that service routine was intense and had as characteristic the singular mobility itself from a creation process and therefore not always its dynamic allowed adequate records. At the same time, from this occurred the field and bibliographic research which allowed the detailed information from the prior milestones and motivated to the practice here reported. The rereading of concepts in an interface with the reports of the interviewees enabled the verification that the model of mental health advocated by psychiatric reform was understood. Once noticed the presence of the beliefs and values of people in motivating energy for the progress of reform, it has gone to fetch theoretical subsidies of administrative order to understand how they saw this building and that uniqueness has been printed. The theoretical way and praxis have tracked here has allowed to analyze how occurred such a process of production and subjectivity and collectives that when organize enabled themselves for analysis and intervention, including in crisis situations. Therefore, it was revealed that ethical and multi-disciplinarity, the humanitarian sense, the coresponsibility, co-production and horizontal management were the key factors for spread from a changing protagonist. One can thus conclude that co-management from that collective has been multi-disciplinary weaving a cross