Macromolecular theory of solvation and structure in mixtures of colloids and polymers

The structural and thermodynamic properties of mixtures of colloidal spheres and non-adsorbing polymer chains are studied within a novel general two-component macromolecular liquid state approach applicable for all size asymmetry ratios. The dilute limits, when one of the components is at infinite dilution but the other concentrated, are presented and compared to field theory and models which replace polymer coils with spheres. Whereas the derived analytical results compare well, qualitatively and quantitatively, with mean-field scaling laws where available, important differences from ``effective sphere'' approaches are found for large polymer sizes or semi-dilute concentrations.Comment: 23 pages, 10 figure

Ask Me! Self-reported features of adolescents experiencing neglect or emotional maltreatment: a rapid systematic review

Neglect is often overlooked in adolescence, due in part to assumptions about autonomy and misinterpretation of behaviors being part of normal adolescent development. Emotional maltreatment (abuse or neglect) has a damaging effect throughout the lifespan, but is rarely recognized amongst adolescents. Our review aims to identify features that adolescents experiencing neglect and/ or emotional maltreatment report. METHOD: A rapid review methodology searched 8 databases (1990-2014), supplemented by hand searching journals, and references, identifying 2,568 abstracts. Two independent reviews were undertaken of 279 articles, by trained reviewers, using standardised critical appraisal. Eligible studies: primary studies of children aged 13-17 years, with substantiated neglect and/ or emotional maltreatment, containing self-reported features. RESULTS: 19 publications from 13 studies were included, demonstrating associations between both neglect and emotional maltreatment with internalising features (9 studies) including depression, post traumatic symptomatology and anxiety; emotional maltreatment was associated with suicidal ideation, while neglect was not (1 study); neglect was associated with alcohol related problems (3 studies), substance misuse (2 studies), delinquency for boys (1 study), teenage pregnancy (1 study), and general victimization for girls (1 study), while emotionally maltreated girls reported more externalising symptoms (1 study). Dating violence victimization was associated with neglect and emotional maltreatment (2 studies), while emotional abuse of boys, but not neglect, was associated with dating violence perpetration (1 study), and neither neglect nor emotional maltreatment had an association with low self-esteem (2 studies). Neither neglect nor emotional maltreatment had an effect on school performance (1 study), but neglected boys showed greater school engagement than neglected girls (1 study). CONCLUSIONS: If asked, neglected or emotionally maltreated adolescents describe significant difficulties with their mental health, social relationships, and alcohol or substance misuse. Practitioners working with youths who exhibit these features should recognize the detrimental impact of maltreatment at this developmental stage, and identify whether maltreatment is a contributory factor that should be addressed

Mental Health and School Functioning for Girls in the Child Welfare System : the Mediating Role of Future Orientation and School Engagement

This study investigated the association between mental health problems and academic and behavioral school functioning for adolescent girls in the child welfare system and determined whether school engagement and future orientation meditated the relationship. Participants were 231 girls aged between 12 and 19 who had been involved with the child welfare system. Results indicated that 39% of girls reported depressive symptoms in the clinical range and 54% reported posttraumatic symptoms in the clinical range. The most common school functioning problems reported were failing a class (41%) and physical fights with other students (35%). Participants reported a mean number of 1.7 school functioning problems. Higher levels of depression and PTSD were significantly associated with more school functioning problems. School engagement fully mediated the relationship between depression and school functioning and between PTSD and school functioning, both models controlling for age, race, and placement stability. Future orientation was not significantly associated with school functioning problems at the bivariate level. Findings suggest that school engagement is a potentially modifiable target for interventions aiming to ameliorate the negative influence of mental health problems on school functioning for adolescent girls with histories of abuse or neglect

A Controversy That Has Been Tough to Swallow: Is the Treatment of Achalasia Now Digested?

Esophageal achalasia is a rare neurodegenerative disease of the esophagus and the lower esophageal sphincter that presents within a spectrum of disease severity related to progressive pathological changes, most commonly resulting in dysphagia. The pathophysiology of achalasia is still incompletely understood, but recent evidence suggests that degeneration of the postganglionic inhibitory nerves of the myenteric plexus could be due to an infectious or autoimmune mechanism, and nitric oxide is the neurotransmitter affected. Current treatment of achalasia is directed at palliation of symptoms. Therapies include pharmacological therapy, endoscopic injection of botulinum toxin, endoscopic dilation, and surgery. Until the late 1980s, endoscopic dilation was the first line of therapy. The advent of safe and effective minimally invasive surgical techniques in the early 1990s paved the way for the introduction of laparoscopic myotomy. This review will discuss the most up-to-date information regarding the pathophysiology, diagnosis, and treatment of achalasia, including a historical perspective. The laparoscopic Heller myotomy with partial fundoplication performed at an experienced center is currently the first line of therapy because it offers a low complication rate, the most durable symptom relief, and the lowest incidence of postoperative gastroesophageal reflux