New Antiadhesive Hydrophobic Polysiloxanes.

Intrinsic hydrophobicity is the reason for efficient bacterial settlement and biofilm growth on silicone materials. Those unwelcomed phenomena may play an important role in pathogen transmission. We have proposed an approach towards the development of new anti-biofilm strategies that resulted in novel antimicrobial hydrophobic silicones. Those functionalized polysiloxanes grafted with side 2-(carboxymethylthioethyl)-, 2-(n-propylamidomethylthioethyl)- and 2-(mercaptoethylamidomethylthioethyl)- groups showed a wide range of antimicrobial properties towards selected strains of bacteria (reference strains Staphylococcus aureus, Escherichia coli and water-borne isolates Agrobacterium tumefaciens, Aeromonas hydrophila), fungi (Aureobasidium pullulans) and algae (Chlorella vulgaris), which makes them valuable antibacterial and antibiofilm agents. Tested microorganisms showed various levels of biofilm formation, but particularly effective antibiofilm activity was demonstrated for bacterial isolate A. hydrophila with high adhesion abilities. In the case of modified surfaces, the relative coefficient of adhesion for this strain was 18 times lower in comparison to the control glass sample.

Modification of Polylactide Nonwovens with Carbon Nanotubes and Ladder Poly(silsesquioxane).

Electrospun nonwovens of poly(L-lactide) (PLLA) modified with multiwall carbon nanotubes (MWCNT) and linear ladder-like poly(silsesquioxane) with methoxycarbonyl side groups (LPSQ-COOMe) were obtained. MWCNT and LPSQ-COOMe were added to the polymer solution before the electrospinning. In addition, nonwovens of PLLA grafted to modified MWCNT were electrospun. All modified nonwovens exhibited higher tensile strength than the neat PLA nonwoven. The addition of 10 wt.% of LPSQ-COOMe and 0.1 wt.% of MWCNT to PLLA increased the tensile strength of the nonwovens 2.4 times, improving also the elongation at the maximum stress.

Supramolecular Interactions in Hybrid Polylactide Blends-The Structures, Mechanisms and Properties.

The conformation of polylactide (PLA) chains can be adjusted by supramolecular interactions (the formation of hydrogen bonds or host-guest complexes) with appropriate organic molecules. The structures formed due to those intermolecular interactions may act as crystal nuclei in the PLA matrix ("soft templating"). In this review, the properties of several supramolecular nucleating systems based on synthetic organic nucleators (arylamides, hydrazides, and 1,3:2,4-dibenzylidene-d-sorbitol) are compared to those achieved with biobased nucleating agents (orotic acid, humic acids, fulvic acids, nanocellulose, and cyclodextrins) that can also improve the mechanical properties of PLA. The PLA nanocomposites containing both types of nucleating agents/additives are discussed and evaluated in the context of their biomedical applicability.

Antimicrobial and Antibiofilm N-acetyl-L-cysteine Grafted Siloxane Polymers with Potential for Use in Water Systems.

Antibiofilm strategies may be based on the prevention of initial bacterial adhesion, the inhibition of biofilm maturation or biofilm eradication. N-acetyl-L-cysteine (NAC), widely used in medical treatments, offers an interesting approach to biofilm destruction. However, many Eubacteria strains are able to enzymatically decompose the NAC molecule. This is the first report on the action of two hybrid materials, NAC-Si-1 and NAC-Si-2, against bacteria isolated from a water environment: Agrobacterium tumefaciens, Aeromonas hydrophila, Citrobacter freundii, Enterobacter soli, Janthinobacterium lividum and Stenotrophomonas maltophilia. The NAC was grafted onto functional siloxane polymers to reduce its availability to bacterial enzymes. The results confirm the bioactivity of NAC. However, the final effect of its action was environment- and strain-dependent. Moreover, all the tested bacterial strains showed the ability to degrade NAC by various metabolic routes. The NAC polymers were less effective bacterial inhibitors than NAC, but more effective at eradicating mature bacterial biofilms.

[School performance as a mediator of the association between family affluence and risk behaviour in adolescents in Poland].

It can be assumed that family socioeconomic status does affect the frequency of undertaking risk behaviours by adolescents directly or indirectly, i.e. by having impact on other proven risk factors. The objective of the study was to show the combined influence of family affluence and school performance on alcohol consumption and tobacco and marijuana smoking, defined as risk behaviour syndrome. Material and Methods: The survey was conducted on a nationwide sample of 1,202 adolescents aged on average 15.6 years (SD=0.31), who participated in the HBSC (Health Behaviour in School-aged Children) survey. Structural equation models were used in the analysis in order to test the hypothesis that school performance is a mediator of the association between family affluence and risk behaviour. Results: It was found that 23.0% of adolescents smoked tobacco; 40.8% drank alcohol; 10.2% smoked marijuana. One fifth of the respondents used one of those substances frequently, i.e. more than 5 days in the last month. It was shown that family affluence is strongly correlated with school performance (p<0.001), however, there was no direct relationship with the general level of psychoactive substance use (p=0.481). In analysing individual substances, only with regard to marijuana it was found that it was used less frequently in more affluent families. School performance resulted to be a stronger mediator of the relationship between family affluence and risk behaviour in girls (Sobel's test: p=0.013) than in boys (p=0.111). In the analysis of the social determinants of the health behaviour of adolescents, indirect correlations and confounding variables should be considered. Worse school performance may be the cause or effect of a more frequent psychoactive substance.

Current trends in tobacco smoking among 15-year-old adolescents in Poland in the background of 30 countries.

The international HBSC (Health Behaviour in School-aged Children) survey has enabled the comparison of the patterns of changes with respect to a number of health indicators in adolescence. The aim of the study was to show international trends and how the position of Poland in international rankings of smoking prevalence has changed since 2002. Material and Methods: The study comprised 30 countries for which data was available from four rounds of HBSC survey (2002-2014). In total, 218 759 15-year-olds were surveyed, including 7289 in Poland. For each country a linear trend was estimated, separately for boys and girls, to describe changes in regular smoking (daily or at least once a week). Results: In the investigated period, the percentage of 15-year-old boys who smoke every week fell in Poland from 26.2% to 15.5%, and the respective percentage in girls decreased from 17.2% to 14.7%. This means annual decrease of 0.88% in boys and 0.24% in girls. In a combined international sample, exactly the same as in Poland rate of change was noted in boys; however, a definitely faster in girls (0.95% a year). The highest rate of change was observed in Ukraine, Germany and Norway, while the lowest in Greece, Croatia and Israel. Poland's position in the international ranking moved from 8th to 24th, providing that the countries are listed according to the growing percentage of 15-year-olds of both genders who smoke regularly. Conclusions: Decrease in the prevalence of smoking among Polish adolescents, observed from the beginning of this century, has been undoubtedly a success related to the implemented preventive measures. However, attention should be drawn to the strategies launched in countries which achieved better results than Poland, as well as to the reasons of less positive trends among Polish girls.

Supramolecular self-assembly of linear oligosilsesquioxanes on mica--AFM surface imaging and hydrophilicity studies.

Linear oligomeric [2-(carboxymethylthio)ethylsilsesquioxanes] (LPSQ-COOH) adsorb spontaneously on muscovite mica and form smooth, well-ordered lamellar structures at the liquid-solid interface. Side carboxylic groups, having donor-acceptor character with regard to hydrogen bonds, are engaged both in multipoint molecule-to-substrate interactions and intermolecular cross-linking. The unique arrangement of silsesquioxane macromolecules, with COOH groups situated at the interface with air, produces highly hydrophilic surfaces of good thermal and solvolytic stability. Supramolecular assemblies of LPSQ-COOH were studied using atomic force microscopy (AFM), angle-resolved X-ray photoelectron spectroscopy (ARXPS) and attenuated total reflectance (ATR) FTIR spectroscopy. Comparative height profile analysis combined with ATR-FTIR studies of the spectral regions characteristic of carboxylic groups and C1s core level envelope by XPS confirmed specific interactions between LPSQ-COOH and mica.

Which aspects of long-term outcome are predicted by positive and negative symptoms in early-onset psychosis? An exploratory eight-year follow-up study.

BACKGROUND: Early-onset psychoses show substantial variability of diagnostic and functional outcome. Finding reliable prognostic factors may allow to allocate resources to those with the worst prognosis. The aim of the study was to gain new insights regarding the potential value of baseline negative and positive symptoms as predictors of outcome in psychoses of early onset. METHOD: Sixty-three patients with early-onset schizophrenia spectrum psychosis hospitalized in an adolescent psychiatry unit were assessed with the Positive and Negative Syndrome Scale during the index admission. Associations with diagnosis, illness course and functional outcome were analysed in mean 8 years of follow-up (range 3.4-13.5 years). RESULTS: The mean age at the index admission and the follow-up was 16.6 ± 1.2 and 24.5 ± 3.0 years, respectively. A significant majority of subjects continued psychiatric treatment (95%) and had been readmitted (71%). The mortality rate was 3% (suicide and accident). Negative symptoms were related to mental health service utilization during the follow-up. General severity of symptoms, specifically positive and cognitive factors were associated with the diagnosis of schizophrenia and inversely with diagnostic shift outside the schizophrenia spectrum at the catamnesis. Poor impulse control at baseline was associated with worse functional outcome. The drug-free subgroup with no occupational/educational activity compared with the drug-treated subjects showed lower levels of baseline negative symptomatology. CONCLUSION: The study findings suggest that in patients with early-onset psychosis negative and positive symptoms show a differential prognostic value. Pharmacotherapy may attenuate the effect of symptoms on functional outcome. These hypotheses need to be tested in future studies using confirmatory approaches.

[Family structure of smoking onset and regular smoking among adolescents in Poland]. / Struktura rodziny a inicjacja tytoniowa i regularne palenie tytoniu przez mlodziez w Polsce.

The aim of the research was to present the prevalence of the regular tobacco smoking, the age of Polish adolescents' smoking onset, as well as the trends in these behaviours in 2010-2014, and to identify the fam- ily factors related to early tobacco initiation, and regular smoking. The study was conducted in 2013/2014 as a part of the HBSC--Health Behaviour in School-aged Children: A WHO collaborative cross-national study, in a representative sample of Polish students (n=4545; 2263 boys, and 2282 girls), in three age groups, in mean age 11.6; 13.6; 15.6. The international, standard HBSC questionnaire was used. Results showed that prevalence of adolescents smoking onset, as well as regular smoking increased with age. There was no statistically significant difference comparing to HBSC study conducted in 2009/10. The important predictors of early tobacco initiation were: the male gender, living in broken or reconstructed family, and living in the rural area. Considering regular smoking, the most important risk factors were: older age (13,15 y.o.) and living with single parent or in reconstructed family. In planning the prevention strategies there is a need to take into account the family role in children and adolescents' smoking prevention, as well as how to support single parents.

[Smoking among 15-year-olds in Poland depending on selected sociodemographic factors--trends 2006-2014]. / Palenie tytoniu przez 15-latków w Polsce w zaleznosci od wybranych czynników socjodemograficznych--tendencje zmian 2006-2014.

International HBSC (Health Behavior in School-aged Children) studies provide an unique opportunity to monitor trends in health behaviours. The purpose of the present study is to describe current trends in the prevalence and determinants of daily smoking among Polish adolescents. Materials and methods: Analyses were based on data from the samples of 15-year-olds who participated in the HBSC study in 2005/2006, 2009/2010 and 2013/2014 (total N = 5722). A dichotomous variable was created, representing daily smoking. Family socioeconomic status was described by a subjective indicator (PFW--perceived family well-off) and neighborhood well-off Daily smoking rates decreased in 2006-2014, however gender influenced. An upward trend was observed in girls. Gender convergence in smoking was due to coexisting increase of rates in girls and decrease in boys. Based on the data from the combined sample, daily smoking was more prevalent in poor families and in regions with more local problems, which applied both to boys and girls. An increase risk of smoking in rich families was observed only in 2006. In the last survey only local area status remained in the final model. Conclusions: Preliminary results of the new HBSC study conducted in Poland suggest unfavorable trends in tobacco smoking mostly in adolescent girls. It is worth to pay attention to the environmental aspects of smoking in adolescence and to analyze both the impact of family and neighborhood well-off.

Executive impairment predicts schizophrenia diagnosis and treatment status in mid-term follow-up of early-onset psychosis.

OBJECTIVES: Early-onset psychoses (EOP) vary considerably with regard to diagnostic stability and functional outcome. The aim of this study was the assessment of executive dysfunction as a predictor of outcome in EOP. METHOD: This was a retrospective cohort study. Twenty-five hospitalized patients with non-affective EOP were assessed with the Wisconsin Card Sorting Test (WCST) during the index admission. Associations with current diagnosis, further admissions, current treatment status and occupational and relationship outcome were analyzed in 6 years of follow-up. RESULTS: The mean age at the index admission and the follow-up was 16.1 ± 1.35 and 22.0 ± 2.1 years, respectively. After discharge, almost all subjects (96%) at least briefly continued psychiatric treatment, and the majority of them (76%) were readmitted. Worse baseline WCST results were associated with a follow-up schizophrenia diagnosis, being a psychiatric in- or outpatient at the moment of follow-up assessment and receiving psychotropic medication. A low number of completed categories correlated with receiving a disability pension at the follow-up. CONCLUSION: In patients with EOP, baseline executive function impairment was associated with schizophrenia diagnosis and psychiatric treatment at the follow-up. The association between baseline results and psychiatric treatment may explain the limited effect of baseline impairment on follow-up occupational and relationship status.

Adolescent insanity revisited: course and outcome in early-onset schizophrenia spectrum psychoses in an 8-year follow-up study.

OBJECTIVES: Despite inclusion of adolescent insanity-a concept proposed by Thomas Clouston in late XIX century-into the broader nosological entity of dementia praecox, the uniqueness of early psychosis is still discussed. The aim of the current study is the assessment of course and outcome in the large sample of early-onset psychosis subjects. METHOD: Of 299 patients hospitalized in the period 1998-2008 in an adolescent psychiatry ward with schizophrenia spectrum diagnosis 158 completed a follow-up interview. Data concerning current diagnosis, further admissions, current treatment status and occupational and relationship outcome were analyzed after a mean of 8 years of follow-up. RESULTS: Mean age at the index admission and the follow-up was 16.6 ± 1.2 and 24.5 ± 3.0 years respectively. After the subsequent discharge almost all subjects (97%) at least briefly continued psychiatric treatment and 75% of patients had been readmitted. Overall diagnostic stability was 42%. For schizophrenia spectrum disorders and schizophrenia diagnostic stability was 72% and 78%, respectively. At the follow-up assessment 119 (77.3%) of the traced subjects declared current psychiatric treatment and 110 (73.3%) were receiving pharmacotherapy. Almost half of the subjects (48%) were employed or studying and more than a third (35.8%) remained in a stable relationship. Different distributions of baseline diagnoses were observed in males and females, and the latter showed a better outcome. CONCLUSION: Early-onset psychoses were characterized by limited diagnostic stability, a necessity for further treatment and hospitalizations and significant percentage of unfavorable functional outcomes. Baseline diagnosis of acute and transient psychotic disorders and female gender were associated with an overall better outcome.

Synergistic Self-Healing Enhancement in Multifunctional Silicone Elastomers and Their Application in Smart Materials.

Organosilicon polymers (silicones) are of enduring interest both as an established branch of polymer chemistry and as a segment of commercial products. Their unique properties were exploited in a wide range of everyday applications. However, current silicone trends in chemistry and materials engineering are focused on new smart applications, including stretchable electronics, wearable stress sensors, protective coatings, and soft robotics. Such applications require a fresh approach to methods for increasing the durability and mechanical strength of polysiloxanes, including crosslinked systems. The introduction of self-healing options to silicones has been recognized as a promising alternative in this field, but only carefully designed multifunctional systems operating with several different self-healing mechanisms can truly address the demands placed on such valuable materials. In this review, we summarized the progress of research efforts dedicated to the synthesis and applications of self-healing hybrid materials through multi-component systems that enable the design of functional silicon-based polymers for smart applications.

Adolescent's perception of peer substance use in relation to social relationship and the neighbourhood social capital.

The objective of the study was to examine the relationship between the perception of selected peer behaviours, social relationships and the neighbourhood social capital among 15-year-old adolescents in Poland. Research was carried out in 2010 as part of a successive series of the HBSC international studies on health behaviours in school-aged children (Health Behaviour in School-aged Children: AWHO Collaborative Cross-national Study). 1551 students in the third grade of junior high schools were surveyed (762 boys and 789 girls). The standard, international, anonymous HBSC questionnaire was used in the surveys. In the analyses the scales for perception of male and female risky peer behaviours, the scales for communication with peers as well as the scales of confidence in friends, social competences and the social capital were used. It was found that the perception among respondents of their male and female friends as individuals engaging in risky behaviours (tobacco smoking, alcohol consumption, getting drunk) was widespread. Almost 40% of respondents claimed that all or most of their friends smoked cigarettes; one in two respondents was of the opinion that they drank alcohol; and one in ten that they get drunk. In the analyses comprising linear regression it was demonstrated that as the intensity of risky peer behaviours increases, selected social relationships deteriorate; this particularly applies to the general assessment of social capital. With regard to preventive measures aimed at counteracting risky behaviours among adolescents more attention should be paid to compliance with the provisions of law on tobacco smoking and alcohol consumption by minors among private individuals as well as those professionally dealing with law enforcement. An important task is also to raise the awareness of adolescents and adults of the relationship between young people engaging in risky behaviours and declining confidence in individuals and formal and informal institutions.

Self-Healing Antimicrobial Silicones-Mechanisms and Applications.

Organosilicon polymers (silicones) are an important part of material chemistry and a well-established commercial product segment with a wide range of applications. Silicones are of enduring interest due to their unique properties and utility. Recently, new application areas for silicone-based materials have emerged, such as stretchable electronics, wearable stress sensors, smart coatings, and soft robotics. For this reason, research interest over the past decade has been directed towards new methods of crosslinking and increasing the mechanical strength of polyorganosiloxanes. The introduction of self-healing mechanisms may be a promising alternative for such high-value materials. This approach has gained both growing research interest and a rapidly expanding range of applications. Inherent extrinsic and intrinsic self-healing methods have been used in the self-healing of silicones and have resulted in significant advances in polymer composites and coatings, including multicomponent systems. In this review, we present a summary of research work dedicated to the synthesis and applications of self-healing hybrid materials containing polysiloxane segments, with a focus on antimicrobial and antifouling coatings.

Hybrid Perovskite-Based Materials Modified with Polyhedral Silsesquioxanes-Structure and Properties.

Polyhedral oligomeric silsesquioxanes (POSS) and hybrid organo-halide perovskites are two important types of hybrid nanoscale frameworks with great potential in materials chemistry. Both are currently under intensive investigation for a wide range of possible applications. Recent results suggest that POSS can be attractive passivating and structure-controlling agents for perovskite materials. In this review, we present the importance of POSS in engineering the structures of inorganic cesium-halide perovskites CsPbX3 (X = Cl, Br, I) to create a new class of hybrid derivatives with improved properties. The combination of these two components can be an effective strategy for controlling the perovskite crystallization process. In addition, passivation of surface defects/bulk and the engineering of energy and optoelectronic properties of perovskite-based materials can be achieved following this method. In this minireview, we summarized the existing literature reports on the structural specificity and properties of hybrid POSS perovskites.

Eugenol-Based Polymeric Materials-Antibacterial Activity and Applications.

Eugenol (4-Allyl-2-methoxy phenol) (EUG) is a plant-derived allyl chain-substituted guaiacol, widely known for its antimicrobial and anesthetic properties, as well as the ability to scavenge reactive oxygen species. It is typically used as a mixture with zinc oxide (ZOE) for the preparation of restorative tooth fillings and treatment of root canal infections. However, the high volatility of this insoluble-in-water component of natural essential oils can be an obstacle to its wider application. Moreover, molecular eugenol can be allergenic and even toxic if taken orally in high doses for long periods of time. Therefore, a growing interest in eugenol loading in polymeric materials (including the encapsulation of molecular eugenol and polymerization of EUG-derived monomers) has been noted recently. Such active macromolecular systems enhance the stability of eugenol action and potentially provide prolonged contact with pathogens without the undesired side effects of free EUG. In this review, we present an overview of methods leading to the formation of macromolecular derivatives of eugenol as well as the latest developments and further perspectives in their pharmacological and antimicrobial applications.

Hybrid Bio-Based Silicone Coatings with Anti-adhesive Properties.

Hybrid polysiloxanes and polysilsesquioxanes grafted with naturally occurring bioactive phytochemicals: eugenol and linalool, were synthesized and investigated with regard to their structure and properties. The two series of materials, differing in the type of inorganic structure and the content of active groups, were coated onto the surface of glass plates, and their antibiofilm activities against bacteria Aeromonas hydrophila were assessed by luminometry and fluorescence microscopy. Bioactivity was correlated with specific properties of the hybrid coatings (chemical structure, surface free energy and adhesiveness). The functionalized polysilsesquioxanes exhibited the most favorable anti-adhesive effects. Cell adhesion after 6 days of incubation, expressed as RLU/cm2, was significantly reduced (44 and 67 for, respectively, Z-E-100 and Z-L-100, compared to 517 for the control glass carrier). The surface stickiness of polysiloxane films deteriorated their anti-adhesion properties, despite the presence of a large amount of bioactive species.

[Smoking initiation and watching television, video, DVD among adolescents in Poland]. / Próby palenia tytoniu a ogladanie telewizji video, dvd przez mlodziez w Polsce.

The aim of the study was to analyse the relationship between smoking initiation and the time spent watching TV, video, DVD by adolescents 11, 13, and 15-year-old in Poland. The research was conducted in 2010 as a part of Health Behaviour in School-aged Children: A WHO Collaborative Cross-national Study (HBSC) in a sample of 4751 students, using a standard, international HBSC questionnaire. It was found that there is a relationship between smoking attempts made by the young people and time spent watching TV during weekdays. In the analyzes using logistic regression combined variable relating to the time to watch TV on weekdays and weekends was used. Nearly a quarter of respondents (24.3%) were qualified to the group of adolescents spending too much time in front of the screen. Age was the strongest predictor of smoking onset. Between 11 and 13 years of age the risk of taking the first cigarette increased three times, and between 11 and 15 years of age more than seven times. Relative risk of smoking attempts related to gender and frequency of watching television, video or DVD was both equal to 1.5. In smoking prevention focused on adolescents it is should be better to pay more attention on constructive leisure time activities, and the role of parents in shaping pro-health attitudes. This is particularly important in the initial stages of schooling, when to develop and enhance the psychosocial competences as a the protective factor of risk taking behaviors among adolescents.

Self-Healing Silsesquioxane-Based Materials.

This review is devoted to self-healing materials (SHM) containing polyhedral oligomeric silsesquioxanes (POSS) as building blocks. The synthetic approach can vary depending on the role POSS are expected to play in a given system. POSS (especially double-decker silsesquioxanes) can be grafted in side chains of a polymer backbone or used as segments of the main chain. Appropriate functionalization allows the formation of dynamic bonds with POSS molecules and makes them an active component of SHM, both as crosslinking agents and as factors that enhance the dynamics of macromolecules in the polymer matrix. The latter effect can be achieved by reversible release of bulky POSS cages or by the formation of separated inclusions in the polymer matrix through hydrophobic interactions and POSS aggregation. The unique properties of POSS-based self-healing systems make them interesting and versatile materials for various applications (e.g., repairable coatings, sealants, sensors, soft materials for tissue engineering, drug delivery, and wound healing).