On the self-aggregation and fluorescence quenching aptitude of surfactant ionic liquids

The aggregation behavior in aqueous solution of a number of ionic liquids was investigated at ambient conditions by using three techniques: fluorescence, interfacial tension, and H-1 NMR spectroscopy. For the first time, the fluorescence quenching effect has been used for the determination of critical micelle concentrations. This study focuses on the following ionic liquids: [C(n)mpy]Cl (1-alkyl-3-methylpyridinium chlorides) with different linear alkyl chain lengths (n = 4, 10, 12, 14, 16, or 18), [C(12)mpip]Br (1-dodecyl-1-methylpiperidinium bromide), [C(12)mpy]Br (1-dodecyl-3-methylpyridinium bromide), and [C(12)mpyrr]Br (1-dodecyl-1-methylpyrrolidinium bromide). Both the influence of the alkyl side-chain length and the type of ring in the cation (head) on the CMC were investigated. A comparison of the self-aggregation behavior of ionic liquids based on 1-alkyl-3-methylpyridinium and 1-alkyl-3-methylpyridinium cations is provided. It was observed that 1-alkyl-3-methylpyridinium ionic liquids could be used as quenchers for some fluorescence probes (fluorophores). As a consequence, a simple and convenient method to probe early evidence of aggregate formation was established.

Prevalence, phenomenology, aetiology and predictors of challenging behaviour in Smith-Magenis syndrome

Background

The prevalence, phenomenology aetiology and correlates of four forms of challenging behaviour in 32 children and adults with Smith-Magenis syndrome (SMS) were investigated.

Methods

Cognitive assessments, questionnaires and semi-structured interviews were used to gather data on intellectual disability, verbal and physical aggression, destructive behaviour and self-injury and on characteristics known to be associated with aggression.

Results

Aggression in SMS was more prevalent (87%), but not more severe than aggression in contrast groups. Aggressive behaviour was more frequently associated with environmental contingencies (e.g. attention, escape and access to tangibles) than self-injury and destructive behaviours. Severity of challenging behaviours was associated with high impulsivity.

Conclusion

Aggression is seen in the majority of people with SMS. Results suggest that behavioural disinhibition and operant social reinforcement are associated with the manifestation of aggression.

Probation staff experiences of managing suicidal and self-harming service users.

The current study sought to explore the impact of suicidal behaviours on probation staff, in relation to their experiences of working with probation service users who have carried out suicide, attempted suicide or self-harm. Thirteen in-depth interviews were carried out with probation staff who had direct contact with probation service users in one probation area, and had varying degrees of experience of managing suicidal or self-injurious service users. These were analysed using thematic analysis and five themes were identified. Findings indicate that staff felt that suicide and self-harm by service users are serious issues which need to be recognized and dealt with in an effective yet compassionate manner. Not attending the suicide prevention training, or lack of experience, were perceived as restricting their ability to know how to deal with these individuals, and offer support. Furthermore, staff were emotionally affected by these incidents and it is recommended that they should continue to be provided with access to appropriate support services after an incident.

La perception des thérapeutes sur les difficultés d’intervenir auprès des adolescents atteints d’un trouble de personnalité limite (TPL) avec conduites suicidaires

Au Québec, les tentatives de suicide chez les adolescents prennent une ampleur considérable dans le réseau public de la santé et un nombre élevé de ces adolescents suicidaires sont épris d’un trouble de personnalité limite (TPL). Ces adolescents TPL présentent de nombreuses crises associées aux conduites suicidaires et aux comportements d’automutilation les amenant à consulter des professionnels de la santé de manière récurrente due, entre autres, aux abandons prématurés de la thérapie. Considérant cette problématique préoccupante, ce mémoire s’est intéressé aux facteurs impliqués dans la complexité de l’intervention auprès des adolescents atteints d’un TPL selon la perception des thérapeutes. Ce projet exploratoire de type qualitatif a été effectué sous forme d’entrevues semi-structurées auprès de onze thérapeutes de troisième ligne en pédopsychiatrie. Dans ce contexte de soins psychiatrique au Québec, les résultats de ce projet confirme la complexité de l’intervention auprès de ces jeunes et font émerger plusieurs facteurs pouvant expliquer les difficultés liées au processus d’intervention en lien, entre autres, à la symptomatologie, au risque suicidaire élevé, au risque d’abandons prématurés, à leur grande instabilité émotionnelle, relationnelle et comportementale influençant, par le fait même, le thérapeute dans son savoir-faire et son savoir-être.

Self-assembly and film stability of a micelle of a single-chain quaternary ammonium amphiphile containing azobenzene on mica

The self-assembling behavior of a single-chain quaternary ammonium amphiphile bearing azobenzene (C₁₂AzoC₆N⁺) on freshly cleaved mica sheet has been investigated by atomic force microscopy (AFM) method. Confocal microscopic Raman spectra confirm the adsorption of the self-assembled monolayer structure. Ex-situ AFM reveals that C₁₂AzoC₆N⁺ forms branch-like stripes indicating the fusion and reorganization of the micelles during drying in air as the in-situ AFM has revealed that surfactant forms spherical micelles on the mica surface. The nano-sized surface structure is strongly dependent on the change of molecular structure, which resulted from photo-induced isomerization. The nano-sized stripe is quite stable even being annealed at 90 °C for 4 h.

Measuring self-care in chronic heart failure : a review of the psychometric properties of clinical instruments

Background : Improved self-care skills and behaviors are an important outcome of patient education and counseling. Both researchers and health professionals need to utilize instruments that are reliable and valid at measuring this outcome to advance our understanding as to the efficacy of clinical practice directed toward improving self-care.

Objective : The aim of this study was to identify instruments that measure chronic heart failure (CHF) self-care and demonstrate their psychometric properties.

Methods : A search of Medline, Cumulative Index to Nursing and Allied Health Literature, Medline, PsycArticles, Psychology and Behavioral Sciences Collection, and PsycINFO databases elucidated studies published between January 1980 and February 2009 that measure CHF self-care. The clinical instruments selected were disease-specific measures of CHF self-care behaviors that are promoted in best practice guidelines. Only instruments that reported estimates of reliability and validity were included in this review. Psychometric properties of the instruments were evaluated according to practice guidelines.

Results : The literature search identified 14 instruments published in peer-reviewed journals that measured constructs that predict or correlate to self-care rather than self-care itself. Only 2 disease-specific measures of self-care were identified (Self-care Heart Failure Index [SCHFI] and European Heart Failure Self-care Behavior Scale [EHFScBS]) that have undergone rigorous psychometric testing in CHF populations. Five aspects of validity had been demonstrated with EHFScBS, and 6 aspects of validity had been demonstrated with SCHFI. Two of 3 aspects of reliability have been demonstrated in both instruments.

Conclusion : Only 2 reliable and valid tools have been developed to specifically measure CHF self-care. Further use of these instruments in the research arena may reduce gaps in our understanding of CHF self-care and further shape clinical practice directed at improving it.

Development of mental health first aid guidelines for deliberate non-suicidal self-injury: a Delphi study

BACKGROUND: It is estimated that around 4% of the population engages, or has engaged, in deliberate non-suicidal self-injury. In clinical samples, the figures rise as high as 21%. There is also evidence to suggest that these figures may be increasing. A family member or friend may suspect that a person is injuring themselves, but very few people know how to respond if this is the case. Simple first aid guidelines may help members of the public assist people to seek and receive the professional help they require to overcome self-injury.

METHODS: This research was conducted using the Delphi methodology, a method of reaching consensus in a panel of experts. Experts recruited to the panels included 26 professionals, 16 people who had engaged in self-injurious behaviour in the past and 3 carers of people who had engaged in self-injurious behaviour in the past. Statements about providing first aid to a person engaged in self-injurious behaviour were sought from the medical and lay literature, but little was found. Panel members were asked to respond to general questions about first aid for NSSI in a variety of domains and statements were extracted from their responses. The guidelines were written using the items most consistently endorsed by the consumer and professional panels.

RESULTS: Of 79 statements rated by the panels, 18 were accepted. These statements were used to develop the guidelines appended to this paper.

CONCLUSION: There are a number of actions which are considered to be useful for members of the public when they encounter someone who is engaging in deliberate, non-suicidal self-injury. These guidelines will be useful in revising curricula for mental health first aid and NSSI first aid training programs. They can also be used by members of the public who want immediate information about how to assist a person who is engaging in such behaviour.

C 3-symmetric discotic liquid crystalline materials for molecular electronics: versatile synthesis and self-organization

This thesis presents the versatile synthesis and self-organization of C3-symmetric discotic nanographene molecules as well as their potential applications as materials in molecular electronics. The details can be described as follows: 1) A novel synthetic strategy towards properly designed C3 symmetric 1,3,5-tris-2’arylbenzene precursors has been developed. After the final planarization by treatment with FeCl3 under mild conditions, for the first time, it became possible to access a variety of new C3-symmetric hexa-peri-hexabenzocoronenes (HBCs) and a series of triangle-shaped nanographenes. D3 symmetric HBC with three alkyl substituents and C2 symmetric HBC with two alkyl substituents were synthesized and found to show the surprising decrease of isotropic points., the self-assembly at the liquid-solid interface displayed a unique zigzag and flower patterns. 2) Triangle-shaped discotics revealed a unique self-assembly behavior in solution, solid state as well as at the solution-substrate interface. A mesophase stability over the broad temperature range with helical supramoelcular arrangement were observed in the bulk state. The honeycomb pattern as the result of novel self-assembly was presented. Triangle-shaped discotics with swallow alkyl tails were fabricated into photovoltaic devices, the supramolecular arrangement upon thermal treatment was found to play a key role in the improvement of solar efficiency. 3) A novel class of C3 symmetric HBCs with alternating polar/apolar substituents was synthesized. Their peculiar self-assembly in solution, in the bulk and on the surface were investigated by NMR techniques, X-ray diffraction as well as different electron microscope techniques. 4) A novel concept for manipulating the intracolumnar stacking of discotics and thus for controlling the helical pitch was presented. A unique staggered stacking in the column was achieved for the first time. Theoretical simulations confirmed this self-organization and predicted that this packing should show the highest charge carrier mobility for all discotics.

Electrostatically self-assembled nanoparticles based on biomolecules

In this work, two different systems were investigated to develop fundamental understanding of the self-assembly behavior of polyelectrolytes and small organic counterions with a certain geometry. Complexes formed were characterized by light scattering in solution, as well as UV-Vis spectroscopy, analytical ultracentrifugation, gel electrophoresis, zeta potential and IR spectroscopy. The morphologies of the aggregates were observed by AFM in dried state on surface. The charge ratio, the valence and the structure of the counterion were shown to represent key parameters in the complexation. The influence of polyelectrolyte type and molecular weights was also determined for the structure formed.rnrnOne system was mainly focused on the association of double-strand DNA with non-intercalating divalent and tetravalent organic counterions. The other model system involved linear NaPSS and oligolysines. In addition, various influences on the morphology of the charged self-assembly complexes in AFM studies were discussed. It was shown that electrostatic self-assembly of DNA and non-intercalating counterions as well as of a linear synthetic polyelectrolyte with oligolysine counterions that can build mutual hydrogen bonds can yield supramolecular aggregates of a defined size. Various morphologies (flower-like, rod-like, toroidal and spherical) of the assemblies were obtained for different combinations of polyelectrolyte and counterions. Results presented in this work are of importance for the fundamental understanding of the association behavior of various polyelectrolytes and organic counterions. The selection of biopolymers for the study may give an opportunity to transfer the basic research results into biological applications, such as gene therapy or drug delivery.rn

Structure and properties of nanostructures from polyelectrolytes and porphyrins: Self-Assembly in aqueous solution

In this work self-assembling model systems in aqueous solution were studied. The systems contained charged polymers, polyelectrolytes, that were combined with oppositely charged counterions to build up supramolecular structures. With imaging, scattering and spectroscopic techniques it was investigated how the structure of building units influences the structure of their assemblies. Polyelectrolytes with different chemical structure, molecular weight and morphology were investigated. In addition to linear polyelectrolytes, semi-flexible cylindrical bottle-brush polymers that possess a defined cross-section and a relatively high persistence along the backbone were studied. The polyelectrolytes were combined with structural organic counterions having charge numbers one to four. Especially the self-assembly of polyelectrolytes with different tetravalent water-soluble porphyrins was studied. Porphyrins have a rigid aromatic structure that has a structural effect on their self-assembly behavior and through which porphyrins are capable of self-aggregation via π-π interaction. The main focus of the thesis is the self-assembly of cylindrical bottle-brush polyelectrolytes with tetravalent porphyrins. It was shown that the addition of porphyrins to oppositely charged brush molecules induces a hierarchical formation of stable nanoscale brush-porphyrin networks. The networks can be disconnected by addition of salt and single porphyrin-decoratedrncylindrical brush polymers are obtained. These two new morphologies, brush-porphyrin networks and porphyrin-decorated brush polymers, may have potential as functional materials with interesting mechanical and optical properties.

The contexts of scratching behavior and postconflict behavior in squirrel monkeys (Saimiri sciureus)

Self-directed behavior (SDB), such as scratching, is a reliable indicator of emotional arousal in non-human primates. In contrast, affiliative behavior, such as social grooming, has been shown to have a calming effect in primates and reduce arousal. In order to test whether the expression of SDB was related to arousal, the scratching behavior of eight captive squirrel monkeys (Saimiri sciureus) was compared across four social contexts (huddling, proximity to others, solitary and post-conflict). In addition,rates of scratching were examined before and after affiliative behavior during the postconflict context. I tested for this effect by using the post-conflict/matched control(PC/MC) method in which post-conflict (PC) behavior of an animal is compared to thebehavior of the same animal in a baseline, nonaggressive situation or a matched control(MC). Context and associated scratching data were obtained from a total of 98 hours of focal sample data. Scratching was significantly lower while animals were huddling thanthe other two contexts. Scratching rates while solitary were significantly higher than those occurring while animals were in proximity. Scratching was also higher in PC than MC. Following conflict, animals were significantly more likely to make contact withthird parties not involved in aggression. Most of these (79%) were a third party approaching a combatant. Further, scratching rates decreased following post-conflict third party contacts and the decrease was not due to a general decrease in scratching thatmight have been occurring after the aggressive interaction. Huddling behavior appears to reduce arousal in squirrel monkeys and may act as a tension-reduction mechanism. The elevated scratching in the solitary context may suggest that squirrel monkeys may be engaged in activities while solitary, such as vigilant behavior that may increase arousal. The third party post conflict affiliative contacts observed were the first such interactions observed in squirrel monkeys. The fact that these third contacts reduced scratching ratesin the combatants indicates that 'consolation' may have been demonstrated in this species. The overall pattern of results suggested that scratching was reliable behavioral indicator of anxiety in squirrel monkeys. These results indicate that overt behavior can be used to assess emotional states in this and other species, acting as a mediator to understanding how emotions regulate social behavior.

Hierarchical self-assembly of nucleotide-appended oligopyrenotides into defined supramolecular objects

Supramolecular DNA assembly blends DNA building blocks with synthetic organic and inorganic molecules giving structural and functional advantages both to the initial self-assembly process and to the final construct. Synthetic molecules can bring a number of additional interactions into DNA nanotechnology. Incorporating extended aromatic molecules as connectors of DNA strands allows folding of these strands through π-π stacking (DNA “foldamers”). In previous work it was shown that short oligopyrenotides (phosphodiester-linked pyrene oligomers) behave as staircase-like foldamers, which cooperatively self-assemble into two-dimensional supramolecular polymers in aqueous medium. Herein, we demonstrate that a 10-mer DNA-sequence modified with 7 pyrene units (see illustration) forms dimensionally-defined supramolecular polymers under thermodynamic conditions in water. We present the self-assembly behavior, morphological studies, and the spectroscopic properties of the investigated DNA-sequences (illustrative AFM picture shown below).

Hierarchical self-assembly of nucleotide-appended oligopyrenotides into defined supramolecular objects

Supramolecular DNA assembly blends DNA building blocks with synthetic organic molecules giving structural and functional advantages. Incorporating extended aromatic molecules as connectors of DNA strands allows folding of these strands through π-π stacking (DNA 'foldamers'). In previous work it was shown that short oligopyrenotides behave as staircase-like foldamers, which cooperatively self-assemble into 2D supramolecular polymers in aqueous medium. Herein, we demonstrate that 10-mer DNA-sequence conjugated with seven pyrene unites forms dimensionally-defined supramolecular polymers under thermodynamic conditions in water. We present the self-assembly behavior, morphologycal studies (AFM and TEM), and the spectroscopic properties (UV/vis, CD) of the investigated pyrene - conjugated DNA-sequence.

Dopaminergic stimulation increases selfish behavior in the absence of punishment threat.

RATIONALE People often face decisions that pit self-interested behavior aimed at maximizing personal reward against normative behavior such as acting cooperatively, which benefits others. The threat of social sanctions for defying the fairness norm prevents people from behaving overly selfish. Thus, normative behavior is influenced by both seeking rewards and avoiding punishment. However, the neurochemical processes mediating the impact of these influences remain unknown. Several lines of evidence link the dopaminergic system to reward and punishment processing, respectively, but this evidence stems from studies in non-social contexts. OBJECTIVES The present study investigates dopaminergic drug effects on individuals' reward seeking and punishment avoidance in social interaction. METHODS Two-hundred one healthy male participants were randomly assigned to receive 300 mg of L-3,4-dihydroxyphenylalanine (L-DOPA) or a placebo before playing an economic bargaining game. This game involved two conditions, one in which unfair behavior could be punished and one in which unfair behavior could not be punished. RESULTS In the absence of punishment threats, L-DOPA administration led to more selfish behavior, likely mediated through an increase in reward seeking. In contrast, L-DOPA administration had no significant effect on behavior when faced with punishment threats. CONCLUSIONS The results of this study broaden the role of the dopaminergic system in reward seeking to human social interactions. We could show that even a single dose of a dopaminergic drug may bring selfish behavior to the fore, which in turn may shed new light on potential causal relationships between the dopaminergic system and norm abiding behaviors in certain clinical subpopulations.

The association between implicit alcohol attitudes and drinking behavior is moderated by baseline activation in the lateral prefrontal cortex

OBJECTIVE Intense alcohol consumption is a risk factor for a number of health problems. Dual-process models assume that self-regulatory behavior such as drinking alcohol is guided by both reflective and impulsive processes. Evidence suggests that (a) impulsive processes such as implicit attitudes are more strongly associated with behavior when executive functioning abilities are low, and (b) higher neural baseline activation in the lateral prefrontal cortex (PFC) is associated with better inhibitory control. The present study integrates these 2 strands of research to investigate how individual differences in neural baseline activation in the lateral PFC moderate the association between implicit alcohol attitudes and drinking behavior. METHOD Baseline cortical activation was measured with resting electroencephalography (EEG) in 89 moderate drinkers. In a subsequent behavioral testing session they completed measures of implicit alcohol attitudes and self-reported drinking behavior. RESULTS Implicit alcohol attitudes were related to self-reported alcohol consumption. Most centrally, implicit alcohol attitudes were more strongly associated with drinking behavior in individuals with low as compared with high baseline activation in the right lateral PFC. CONCLUSIONS These findings are in line with predictions made on the basis of dual-process models. They provide further evidence that individual differences in neural baseline activation in the right lateral PFC may contribute to executive functioning abilities such as inhibitory control. Moreover, individuals with strongly positive implicit alcohol attitudes coupled with a low baseline activation in the right lateral PFC may be at greater risk of developing unhealthy drinking patterns than others.