Temperature-responsive bioactive glass/polymer hybrids allow for tailoring of ion release.

Intelligent biomaterials react to their surrounding conditions, and hybrid materials are acknowledged for their remarkable customizability, achieved through the meticulous control of nanoscale interactions between organic and inorganic phases. Bioactive glasses (BG) are used clinically to regenerate bone due to their degradability, ion release, and capacity to stimulate the formation of new body tissue. In our study, we developed a core-shell hybrid system using sol-gel derived BG nano particles as the core and poly (N-isopropyl acrylamide) (PNIPAM) as the shell. This approach aims to combine the therapeutic ion release of BG with the temperature-responsive properties of PNIPAM. Our size analysis by dynamic light scattering at varying temperatures shows the formation of BG aggregates driven by the coil-to-globule transition of PNIPAM on the BG surface. This transition also affected the ion release from the core-shell system through an increase in ion transport through the porous hybrid network. Our study therefore illustrates the ability to adjust the dissolution properties of the core-shell system via surrounding temperature and, thus, control the release of Ca ions from the BG.

Dispersion, ionic bonding and vibrational shifts in phospho-aluminosilicate glasses.

Understanding the relationships between structure and properties of aluminosilicate glasses is of interest in magmatic studies as well as for glass applications as mechanical or optical components. Glass properties may be tailored by the incorporation of additional elements, and here we studied the effect of phosphate incorporation on refractive index and the degree of ionic bonding in aluminosilicate glasses. The studied glasses in the system SiO2-Al2O3-Na2O-P2O5 had a metaluminous composition (Al:Na = 1) with the content of SiO2 ranging from 50 to 70 mol% and of P2O5 from 0 to 7.5 mol%. Refractive index was measured at four wavelengths from visible to near-infrared and found to decrease both with increasing P2O5 content (at the expense of NaAlO2) and with increasing SiO2 content (by substitution of SiO4 for AlO4 groups). This trend correlated with a decrease in density while, additionally, the formation of Al-O-P bonds with an SiO2-like structure may account for this change. The degree of ionic bonding, assessed via optical basicity and oxygen polarisability, decreased with increasing P2O5 and SiO2 content. Despite the complexity of the studied glasses, oxygen polarisability and optical basicity were found to follow Duffy's empirical equation for simple oxide glasses. In the high frequency infrared and Raman spectra, band shifts were observed with increasing P2O5 and SiO2 content. They indicated changing average bond strength of the glass network and showed a linear correlation with optical basicity.

Small increases in group size improve small shoals' response to water flow in zebrafish.

Social context may influence the perception of sensory cues and the ability to display refined behavioral responses. Previous work suggests that effective responses to environmental cues can be contingent on having a sufficient number of individuals in a group. Thus, the changes in group size may have profound impacts, particularly on the behavior of small social groups. Using zebrafish (Danio rerio), here we examined how changes in group size influence the ability to respond to changes in water flow. We found that fish in relatively larger groups displayed stronger rheotaxis even when comparing pairs of fish with groups of four fish, indicating that a small increase in group size can enhance the responsiveness to environmental change. Individual fish in relatively larger groups also spent less time in the energetically costly leading position compared to individuals in pairs, indicating that even a small increase in group size may provide energetic benefits. We also found that the shoal cohesion was dependent on the size of the group but within a given group size, shoal cohesion did not vary with flow rate. Our study highlights that even a small change in group size could significantly affect the way social fish respond to the changes in water flow, which could be an important attribute that shapes the resilience of social animals in changing environments.

The effect of moderate-intensity exercise on nightly variability in objectively measured sleep parameters among older women.

Objective/Background: Exercise training has been demonstrated to beneficially influence mean-level measures of sleep; however, few studies have examined the impact of an exercise intervention on night-to-night variability in sleep. This study investigated whether four months of moderate-intensity exercise impacted night-to-night variability in sleep among older women. Methods: Participants (n = 49) were randomized to one of two moderate-intensity walking programs with different doses of energy expenditure: low-dose (n = 23: 8 kcal/kg of body weight per week) or high-dose (n = 26: 14 kcal/kg of body weight per week). Sleep parameters were assessed objectively via actigraphy at baseline, mid- (2 months), and postintervention (4 months). Nightly variability in each of the sleep parameters was calculated using the seven-day standard deviation (SD) and a coefficient of variation (SD/mean x 100%). Cardiorespiratory fitness (VO2peak) was measured at baseline and postintervention using a graded treadmill test. Results: Both measures of nightly variability demonstrated a borderline to significantly lower amount of night-to-night variability in wake time after sleep onset (WASO) and number of awakenings at postintervention in comparison to baseline (p ≤ 0.05). Higher VO2peak levels at baseline were associated with less time in bed and lower total sleep time variability throughout the exercise intervention (p < 0.05). Conclusion: Overall, participation in moderate-intensity exercise was observed to reduce the amount of nightly variability for WASO and number of awakenings over time in older women.

[Species diversity of non-tuberculous mycobacteria isolated from aquatic environments of General Pico city, Province of La Pampa (Argentina)]. / Diversidad de especies de micobacterias no tuberculosas aisladas en ambientes acuáticos de la ciudad de General Pico, La Pampa, Argentina.

Non-tuberculous mycobacteria (NTM) are studied not only for their importance as emerging opportunistic pathogens but also for their applications in biotechnology and bioremediation. Our aim was to determine the occurrence and diversity of mycobacteria in different aquatic habitats of General Pico city, Province of La Pampa. The percentage of samples with positive cultures for mycobacteria were the following: 37.5% recovered from the water supply distribution system; 32.6% from the aquifer that supplies water to the distribution system; 36.8% from rain water; 53.1% from the two wetlands in the area of influence; 80% from indoor swimming pools; and 33.3% from water fountains in downtown public squares. Of the 90 NTM isolates, 8.9% could not be identified at the species level with any of the used methods, phenotypic tests and molecular methods. Mycobacterium fortuitum and Mycobacterium gordonae were the most frequently isolated species. Some of the identified species such as, M. fortuitum, M. gordonae, M. intracellulare, M. vaccae, M. lentiflavum and M. nonchromogenicum, have been reported in cases of mycobacteriosis in Argentina. Mycobacteria with values higher than 0.8mg/ml of residual active chlorine were not recovered from the drinking water supply network, whereas in the swimming pools the presence of up to 1.5mg/l was not a constraint. Based on our results, the presence of mycobacteria in aquatic environments is close to 35% and their occurrence and diversity is affected both by contact with man and his activities as well as by the existence of animal life.

Questionnaire-based problematic relationship to eating and food is associated with 25 year body mass index trajectories during midlife: The Coronary Artery Risk Development In Young Adults (CARDIA) Study.

OBJECTIVE: Problematic eating behaviors and attitudes are of public health concern. Questionnaire-based assessment of these behaviors is important for large-scale research on eating behaviors. The questionnaire on eating and weight patterns-revised (QEWP-R) measures potential problematic behaviors and attitudes toward food (including anxieties, compensatory actions, overeating and loss of control, dieting, and shape concerns) that in aggregate may indicate diagnosable eating disorders. An important question regards the prevalence of these issues and their longitudinal associations with body mass index (BMI) in generally healthy middle aged adults. METHOD: Based on eight constructs measured on QEWP-R, we created a new problematic relationship to eating and food (PREF) scale by assigning a point for each construct endorsed. Analyses were conducted in 3,892 black and white men and women participating in the community-based Coronary Artery Risk Development in Young Adults (CARDIA) Study. The QEWP-R was administered in CARDIA year 10, when participants were aged 27-41 years. We used linear regression to model the relationship of individual constructs and the PREF scale to BMI over CARDIA follow-up. RESULTS: Fifty-five percent of participants had 1-5 points and 4% had 6-8 points on the PREF scale. Each separate construct was positively associated with BMI, except concern about weight and shape. Adjusting for age, race, sex, education, and study center, mean BMI at CARDIA year 10, the time of PREF assessment, was approximately 1.0-2.5 kg/m2 higher per PREF category. CONCLUSION: In middle age, problematic behaviors and attitudes toward food were common and associated with higher BMI.

Development of behavioral responses to thermal challenges.

Body temperature regulation involves the development of responses to cold and warm challenges. Matching our understanding of the development of body temperature regulation to warm challenges with that of cold challenges will enhance our understanding of the ontogeny of thermoregulation and reveal different adaptive specializations. Warm and cold thermoregulation are important processes, and they include direct thermal effects on offspring, as well as indirect effects on them, such as those imposed by thermally associated alterations of maternal behavior. The present paper is a selective review of the existing literature and a report of some new empirical data, aimed at processes of mammalian development, especially those affecting behavior. We briefly discuss the development of body temperature regulation in rats and mice, and thermal aspects of maternal behavior with emphasis on responses to high temperatures. The new data extend previous analyses of individual and group responses in developing rodents to warm and cool ambient temperatures. This literature not only reveals a variety of adaptive specializations during development, but it points to the earlier appearance in young mammals of abilities to combat heat loss, relative to protections from hyperthermia. These relative developmental delays in compensatory defenses to heating appear to render young mammals especially vulnerable to environmental warming. We describe cascading consequences of warming-effects that illustrate interactions across levels of physiological, neural, and behavioral development.

E-Media Use and Preferences for Physical Activity and Public Health Information: Results of a Web-Based Survey.

CONTEXT: As social media (eg, Twitter) continues to gain widespread popularity, health research and practice organizations may consider combining it with other electronic media (e-media) channels (eg, Web sites, e-newsletters) within their communication plans. However, little is known about added benefits of using social media when trying to reach public health audiences about physical activity. OBJECTIVE: Learn about current use and preference for e-media communication channels among physical activity researchers and practitioners. DESIGN: A Web-based survey was used, open for responses from August 20, 2015, through January 5, 2016. Survey participation was voluntary and anonymous. The survey was advertised through multiple channels targeting physical activity researchers and practitioners, including announcements on professional listservs and in e-newsletters, Twitter, and posts on Facebook pages of public health organizations. SETTING AND PARTICIPANTS: A total of 284 survey respondents had complete data. MAIN OUTCOME MEASURES: Typical use of e-media to receive, seek out, and share information about physical activity and health and what appeals to researchers and practitioners for professional use. RESULTS: Most respondents preferred non-social media channels to social media and these preferences did not differ widely when examining subgroups such as researchers versus practitioners or social media users versus nonusers. There were few differences by respondent demographics, though younger respondents reported using social media more than older respondents. However, limiting analyses to respondents who identified as social media users, only about 1% of respondents ranked social media sources as their preferred channels for information; thus, most people would continue to be reached if communication remained largely via non-social media e-media channels. CONCLUSIONS: The present study supports growing evidence that careful surveying of a target audience should be undertaken when considering new communication channels, as preference and use may not support the effort required to create and maintain resource-intensive strategies like social media.

High chloride content calcium silicate glasses.

Chloride is known to volatilize from silicate glass melts and until now, only a limited number of studies on oxychloride silicate glasses have been reported. In this paper we have synthesized silicate glasses that retain large amounts of CaCl2. The CaCl2 has been added to the calcium metasilicate composition (CaO·SiO2). Glasses were produced via a melt quench route and an average of 70% of the chloride was retained after melting. Up to 31.6 mol% CaCl2 has been successfully incorporated into these silicate glasses without the occurrence of crystallization. 29Si MAS-NMR spectra showed the silicon being present mainly as a Q2 silicate species. This suggests that chloride formed Cl-Ca(n) species, rather than Si-Cl bonds. Upon increasing the CaCl2 content, the Tg reduced markedly from 782 °C to 370 °C. Glass density and glass crystallization temperature decreased linearly with an increase in the CaCl2 content. However, both linear regressions revealed a breakpoint at a CaCl2 content just below 20 mol%. This might be attributed to a significant change in the structure and is also correlated with the nature of the crystallizing phases formed upon heat treatment. The glasses with less than 19.2 mol% CaCl2 crystallized to wollastonite, whilst the compositions with CaCl2 content equal to or greater than 19.2 mol% are thought to crystallize to CaCl2. In practice, the crystallization of CaCl2 could not occur until the crystallization temperature fell below the melting point of CaCl2. The implications of the results along with the high chloride retention are discussed.

Risk assessment of legionellosis in cardiology units.

Infective Endocarditis (IE) is a disease with high morbidity and mortality. Nowadays, in addition to classic pathogens were isolated exigent Gram negative bacteria as A. baumannii, A. lwoffii, C. burnetii, Bartonella, Chlamydia and Legionella. We present our experience of Legionella isolations in environmental sample (water and air) collected from the Cardiology units belonging to two hospitals in Messina (Italy). A total of 80 samples were carried out, 30 and 50, respectively in the first and in the second structure: 55 of water and 25 of aerosol. The positivity of 30% of the water samples analyzed and 15% of those aerosol strengthens the conviction of the need for greater environmental monitoring, especially in the wards at high risk.

Campylobacter: from microbiology to prevention.

In last years, Campylobacter spp has become one of the most important foodborne pathogens even in high-income countries. Particularly, in Europe, Campylobacteriosis is, since 2005, the foodborne disease most frequently notified and the second in USA, preceded by the infection due to Salmonella spp. Campylobacter spp is a commensal microorganism of the gastrointestinal tract of many wild animals (birds such as ducks and gulls), farm animals (cattle and pigs) and companion animals (such as dogs and cats) and it is responsible for zoonoses. The transmission occurs via the fecal-oral route through ingestion of contaminated food and water. The disease varied from a watery diarrhea to a severe inflammatory diarrhea with abdominal pain and fever and can be burdened by some complications. The main recognized sequelae are Guillain-Barré Syndrome (GBS), the Reactive Arthritis (REA) and irritable bowel syndrome (IBS). Recently, many cases of Campylobacter spp isolated from human infections, showed an important resistance to various antibiotics such as tetracyclines and fluoroquinolones. For these reasons, the prevention of this infection plays an essential role. Many preventive measures exist to limit the transmission of the pathogens and the subsequent disease such as the health surveillance, the vaccination of the poultry and the correct food hygiene throughout the entire production chain. A global surveillance of Campylobacteriosis is desirable and should include data from all countries, including notifications of cases and the microbiological data typing of strains isolated from both human and animal cases.

Cardiovascular effects of intensive lifestyle intervention in type 2 diabetes.

BACKGROUND: Weight loss is recommended for overweight or obese patients with type 2 diabetes on the basis of short-term studies, but long-term effects on cardiovascular disease remain unknown. We examined whether an intensive lifestyle intervention for weight loss would decrease cardiovascular morbidity and mortality among such patients. METHODS: In 16 study centers in the United States, we randomly assigned 5145 overweight or obese patients with type 2 diabetes to participate in an intensive lifestyle intervention that promoted weight loss through decreased caloric intake and increased physical activity (intervention group) or to receive diabetes support and education (control group). The primary outcome was a composite of death from cardiovascular causes, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for angina during a maximum follow-up of 13.5 years. RESULTS: The trial was stopped early on the basis of a futility analysis when the median follow-up was 9.6 years. Weight loss was greater in the intervention group than in the control group throughout the study (8.6% vs. 0.7% at 1 year; 6.0% vs. 3.5% at study end). The intensive lifestyle intervention also produced greater reductions in glycated hemoglobin and greater initial improvements in fitness and all cardiovascular risk factors, except for low-density-lipoprotein cholesterol levels. The primary outcome occurred in 403 patients in the intervention group and in 418 in the control group (1.83 and 1.92 events per 100 person-years, respectively; hazard ratio in the intervention group, 0.95; 95% confidence interval, 0.83 to 1.09; P=0.51). CONCLUSIONS: An intensive lifestyle intervention focusing on weight loss did not reduce the rate of cardiovascular events in overweight or obese adults with type 2 diabetes. (Funded by the National Institutes of Health and others; Look AHEAD ClinicalTrials.gov number, NCT00017953.).

Well-Defined SiO2@P(EtOx-stat-EI) Core-Shell Hybrid Nanoparticles via Sol-Gel Processes.

Positively charged nanoparticles (NPs) are very interesting for biomedical and pharmaceutical applications, such as nonviral gene delivery. Here, the synthesis of SiO2 nanoparticles with a covalently grafted poly(2-ethyl-2-oxazoline) (PEtOx) shell (SiO2@PEtOx) is presented. PEtOx with a degree of polymerization of 20 and 38 is synthesized via microwave supported cationic ring-opening polymerization and subsequently end-functionalized with a triethoxysilyl linker for subsequent grafting to silica particles with hydrodynamic radii of 7, 31, and 152 nm. The resulting SiO2@PEtOx particles are characterized by using dynamic light scattering (DLS), transmission electron microscopy (TEM, cryoTEM), and scanning electron microscopy (SEM) to determine changes in particle size. Thermal gravimetrical analysis is used to quantify the amount of polymer on the silica surface. Subsequent in situ transformation of SiO2@PEtOx particles into SiO2@P(EtOx-stat-EI) (poly(2-ethyl-2-oxazoline-stat-ethylene imine) grafted silica particles) under acidic conditions inverts the surface charge from negative to positive according to ζ-potential measurements. The P(EtOx-stat-EI) shell could be used for the deposition of Au NP afterward.

Are early first trimester weights valid proxies for preconception weight?

BACKGROUND: An accurate estimate of preconception weight is necessary for providing a gestational weight gain range based on the Institute of Medicine's guidelines; however, an accurate and proximal preconception weight is not available for most women. We examined the validity of first trimester weights for estimating preconception body mass index category. METHODS: Under identical measurement conditions, preconception weight and two first trimester weights (i.e., 4-10 and 12 weeks gestation) were obtained (n = 43). RESULTS: The 4-10 week and the 12 week weight correctly classified 95 and 91% women, respectively. Mean weight changes were relatively small overall (M = 0.74 ± 1.99 kg at 4-10 weeks and M = 1.02 ± 2.46 at 12 weeks). There was a significant difference in mean weight gain by body mass index category at 4-10 weeks (-0.09 ± 1.86 kg for normal weight participants vs. 1.61 + 1.76 kg for overweight/obese participants, p = 0.01), but not at 12 weeks (0.53 ± 2.29 kg for normal weight participants vs. 1.54 ± 2.58 kg for overweight/obese participants). CONCLUSIONS: Assigning gestational weight gain guidelines based on an early first trimester weight resulted in 5-9% of women being misclassified depending on the gestational week the weight was obtained. Thus, most women are correctly classified based on a first trimester weight, particularly an early first trimester weight, although it is possible that modeling strategies could be developed to further improve estimates of preconception body mass index category. TRIAL REGISTRATION: Clinicaltrials.gov # NCT01131117 , registered May 25, 2010.

Reconsidering the "acculturation gap" narrative through an analysis of parent-adolescent acculturation differences in Mexican American families.

Using a sample of 193 Mexican American adolescents (M age at Wave 1 = 14) and three waves of data over two years, this study longitudinally examined the effects of parent-youth acculturation differences, relative to no differences, on parent-adolescent relationship quality and youth problem behavior. We examined parent-youth differences in overall acculturation, Mexican acculturation, and American acculturation. We differentiated between cases in which the adolescent was more acculturated than the parent and cases in which the parent was more acculturated than the adolescent. Adolescents were more commonly similar to their parents than different. Where differences existed, adolescents were not uniformly more American than their parents, no type of difference was associated with parent-adolescent relationship quality, and no type of difference in overall acculturation was associated with youth problem behavior. One type of difference by dimension (adolescent had less Mexican acculturation than mother) was associated with less risk of problem behavior.

Bioactive glasses­structure and properties.

Bioactive glasses were the first synthetic materials to show bonding to bone, and they are successfully used for bone regeneration. They can degrade in the body at a rate matching that of bone formation, and through a combination of apatite crystallization on their surface and ion release they stimulate bone cell proliferation, which results in the formation of new bone. Despite their excellent properties and although they have been in clinical use for nearly thirty years, their current range of clinical applications is still small. Latest research focuses on developing new compositions to address clinical needs, including glasses for treating osteoporosis, with antibacterial properties, or for the sintering of scaffolds with improved mechanical stability. This Review discusses how the glass structure controls the properties, and shows how a structure-based design may pave the way towards new bioactive glass implants for bone regeneration.

Attributions of Fathering Behaviors Among Adolescents: The Role of Gender, Ethnicity, Family Structure, and Depressive Symptoms.

Little attention has been paid to how early adolescents make attributions for their fathers' behavior. Guided by symbolic interaction theory, we examined how adolescent gender, ethnicity, family structure, and depressive symptoms explained attributions for residential father behavior. 382 adolescents, grouped by ethnicity (European American, Mexican American) and family structure (intact, stepfamilies), reported attributions for their fathers' positive and negative behaviors. Results indicated that for positive events girls made significantly more stable attributions, whereas boys made more unstable attributions. Mexican American adolescents tended to make more unstable attributions for positive events than European Americans, and adolescents from intact families made more stable attributions for positive events than adolescents from stepfamilies. Implications are discussed for the role of attributions in father-adolescent relationships as prime for intervention in families.

Antimicrobial Biomaterials Based on Physical and Physicochemical Action.

Developing effective antimicrobial biomaterials is a relevant and fast-growing field in advanced healthcare materials. Several well-known (e.g., traditional antibiotics, silver, copper etc.) and newer (e.g., nanostructured, chemical, biomimetic etc.) approaches have been researched and developed in recent years and valuable knowledge has been gained. However, biomaterials associated infections (BAIs) remain a largely unsolved problem and breakthroughs in this area are sparse. Hence, novel high risk and potential high gain approaches are needed to address the important challenge of BAIs. Antibiotic free antimicrobial biomaterials that are largely based on physical action are promising, since they reduce the risk of antibiotic resistance and tolerance. Here, selected examples are reviewed such antimicrobial biomaterials, namely switchable, protein-based, carbon-based and bioactive glass, considering microbiological aspects of BAIs. The review shows that antimicrobial biomaterials mainly based on physical action are powerful tools to control microbial growth at biomaterials interfaces. These biomaterials have major clinical and application potential for future antimicrobial healthcare materials without promoting microbial tolerance. It also shows that the antimicrobial action of these materials is based on different complex processes and mechanisms, often on the nanoscale. The review concludes with an outlook and highlights current important research questions in antimicrobial biomaterials.

Exploring the cellulolytic activity of environmental mycobacteria.

Although studies on non-tuberculous mycobacteria have increased in recent years because they cause a considerable proportion of infections, their cellulolytic system is still poorly studied. This study presents a characterization of the cellulolytic activities of environmental mycobacterial isolates derived from soil and water samples from the central region of Argentina, aimed to evaluate the conservation of the mechanism for the degradation of cellulose in this group of bacteria. The molecular and genomic identification revealed identity with Mycolicibacterium septicum. The endoglucanase and total cellulase activities were assessed both qualitatively and quantitatively and the optimal enzymatic conditions were characterized. A specific protein of around 56 kDa with cellulolytic activity was detected in a zymogram. Protein sequences possibly arising from a cellulase were identified by mass spectrometry-based shotgun proteomics. Results showed that M. septicum encodes for cellulose- and hemicellulose-related degrading enzymes, including at least an active ß-1,4 endoglucanase enzyme that could be useful to improve its survival in the environment. Given the important health issues related to mycobacteria, the results of the present study may contribute to the knowledge of their cellulolytic system, which could be important for their ability to survive in many different types of environments.

Plants buffer some of the effects of a pair of cadmium-exposed zebrafish on the un-exposed majority.

Certain individuals have a disproportionate effect on group responses. Characteristics may include susceptibility to pollutants, such as cadmium (Cd), a potent trace metal. Here, we show how a pair of Cd-exposed individuals can impact the behavior of unexposed groups. We used behavioral assessments to characterize the extent of the effects of the Cd-exposed individuals on group boldness, cohesion, foraging, activity, and responses to plants. We found that groups with a pair of Cd-exposed fish remained closer to novel stimuli and plants than did groups with untreated (control) fish. The presence of plants reduced Cd-induced differences in shoal cohesion and delays feeding in male shoals. Shoals with Cd- and water-treated fish were equally active. The results suggest that fish acutely exposed to environmentally relevant Cd concentrations can have profound effects on the un-exposed majority. However, the presence of plants may mitigate the effects of contaminants on some aspects of social behavior.