Visoelastic studies on thermoplastic polyurethane nanocomposites using a nano-hardness tester

The viscoelastic behaviour of a range of polyurethane thermoplastic elastomer montmorillonite nanocomposites has been studied using a nanohardness tester. For softer Shore hardness 80A materials, the introduction of the organo-clay increased the creep strain obtained while the nano-indentor was held at constant load. The increase in creep strain was greatest for materials containing an organo-clay modified with a more hydrophilic quaternary alkylammonium surfactant and with higher loadings of the hydrophilic organo-clay. This suggested the effect might be due to a plasticising effect of the excess surfactant. For the harder Shore hardness 55D materials, the addition of the organo-clays produced only a small decrease in the creep strain, probably due to the interconnected hard domains in this material.

Psychotropic medication utilization in a child and adolescent mental health service

Objectives: This study aimed to identify rates and correlates of psychotropic drug utilization in children and adolescents in inpatient and outpatient settings. Methods: A retrospective chart review examined 122 inpatient and 126 outpatient charts from a metropolitan child and youth mental health service in Brisbane, Australia. Results: Inpatients received more psychotropic medication than outpatients (71% vs. 25%; p < 0.01). Patients receiving medication were older, had longer hospital admissions, and more complex presentations, including history of abuse or suicide attempts and more diagnoses (all p < 0.01). Selective serotonin reuptake inhibitors (SSRIs) were the most frequently used drug class (44% inpatients; 14% outpatients), primarily indicated for mood disorders (31%). SSRIs and newer antidepressants (ADs) were used more frequently in patients with a high suicide risk (p < 0.01). Atypical antipsychotics (APs) were also used (inpatients 23%; outpatients 3%), primarily for behavioral disturbances. Half of those receiving medication (51%) received polypharmacy (> 1 concurrent drug), with up to four drugs used at one time. Rates of polypharmacy were highest among patients receiving antipsychotics. Conclusions: Use of psychotropic medication is frequent in this population. Future research should initially focus on inpatients and intensive treatment settings and examine both safety and efficacy of interventions for depression in young people, atypical antipsychotics for behavioral disturbances, and polypharmacy.

Low back pain patients demonstrate increased hip extensor muscle activity during standardized submaximal rotation efforts

Study Design. A comparative study of trunk and hip extensor muscle recruitment patterns in 2 subject groups. Objective. To examine for changes in recruitment of the hip and back extensor muscles during low level isometric trunk rotation efforts in chronic low back pain (CLBP) subjects by comparison with matched asymptomatic control subjects. Summary of Background Data. Anatomic and biomechanical models have provided evidence that muscles attaching to the thoracolumbar fascia (TLF) are important for providing stabilization to the lumbopelvic region during trunk rotation. This has guided rehabilitation programs. The muscles that link diagonally to the posterior layer of the TLF have not previously been examined individually and compared during low-level trunk rotation efforts in CLBP patients and matched controls. Methods. Thirty CLBP patients and 30 matched controls were assessed using surface electromyography (EMG) as they performed low-level isometric rotation efforts while standing upright. Muscles studied included latissimus dorsi, erector spinae, upper and lower gluteus maximus, and biceps femoris. Subjects performed the rotation exertion with various levels of external trunk support, related to different functional tasks. Results. EMG results demonstrated that subjects with CLBP had significantly higher levels of recruitment for the lower and upper gluteus maximus (P < 0.05), hamstrings (P < 0.05), and erector spinae muscles (P < 0.05) during rotation to the left compared with the control subjects. Conclusion. This study provided evidence of increased muscle recruitment in CLBP patients when performing a standardized trunk rotation task. These results may have implications for the design of therapeutic exercise programs for CLBP patients.

L'aperception de soi chez shihab al-din al-suhrawardi et l'heritage avicennien

Avicenna (d. 1037) bequeathed the Arabic philosophical tradition with an aporia : self-knowledge is conceived, at times, in terms of intellection, at other times, in terms of apperception. In his Book of Discussions and Book of Notes, Avicenna has lengthy discussions on apperception, defined as a direct ontological mode of knowledge. Heir to this tradition, Shihāb al-Dīn al-Suhrawardī (d. 1191) moved away from the first conception of self-knowledge as intellection to adopt the second conception of an apperception of the self as a direct, intuitive and "presential (hcombining dot belowudcombining dot belowūrī)" perception, and which he defended with four types of arguments.