Numerical simulations of annular extrudate swell of polymer melts

Numerical viscoelastic simulations were carried out using a K-BKZ type of separable integral constitutive equation. Both reversible and irreversible models were tried for several types of damping functions to calculate the annular extrudate behavior of high-density polyethylene (HDPE). There are two aims in this study; first, to clarify the properties of these dumping functions, and second, to investigate the influence of rheological characteristics on annular extrudate swell. In these numerical simulations, relaxation spectrum and shear viscosity were fixed, and the other characteristics were varied. The reversional response of the damping function mainly has an effect on the magnitude of the area swell even if the die is straight. The irreversible model expresses the experimental results of annular extrudate swell better than the reversible model. The accurate fitting of N1 by the damping model is important for predicting it. The magnitude of N1 predicted from the Wagner exponential model is lower than that of the PSM model, and the area swell shows the same tendency as N1. A modified PSM model that allows the N1 curve to shift can fit the magnitude of area swell. The relationship between the diameter and thickness of the extrudate depends on N2/N1, and it was estimated by simple linear elasticity of solids. The time dependent viscosity varies with the type of damping function, and it influences the time-dependent swell.     

Micropatterning of liquid crystalline polyacetylene derivative by using self-organization processes

Side-chain type liquid crystalline polyacetylene, which has mesogenic moieties as side chains, is one of the promising materials for practical applications in the electronics. Micropatterning of the conductive polymer is a significant issue in this field. We show a simple method to fabricate micropatterns of side-chain type liquid crystalline polyacetylene derivative. Under dry condition, stripes patterns and lattice pattern were formed based on the fingering instability and stick-slip motion of the receding meniscus. Honeycomb-patterned polymer film was obtained by casting polymer solution under humid condition. The micropatterns drastically changed by changing solution concentration and preparation conditions.     

Noninsulin-dependent diabetes mellitus-related encephalopathy presenting with amnesia, personality change, and autonomic seizure

OBJECTIVE: To determine the knowledge of rubella immune status among practicing obstetrician-gynecologists in the United States and of rubella immunity policies covering healthcare workers in the obstetric-care office setting. DESIGN: Mailed survey questionnaire, August through December 1994. SETTING: Physicians from multiple-practice sites including private office, public institution, university or teaching hospital, and closed panel health maintenance organization settings. PARTICIPANTS: 3,302 practicing obstetrician-gynecologists, chosen by a systematic random sample from the AMA national physician database. MAIN OUTCOME MEASURES: Participants were defined as rubella immune if they reported knowledge of prior rubella vaccination or positive antibody titer. Knowledge of a policy for documenting rubella immunity among employees in the office-based practice setting also was assessed. RESULTS: Questionnaires were returned from 50% (1,666) of the 3,302 surveyed, and 96% (1,599) were evaluable. Approximately 20% (304/1,599) of the responding obstetrician-gynecologists did not have knowledge of documented rubella immunity, and the majority of office-based practices did not require documentation of rubella immunity in the following groups: physicians, 66% (723/1,094); office nurses, 62% (666/1,070); and other office staff, 69% (728/1,063). Sixty-two percent (993/1,599) of responding physicians had individual rubella serologies performed, with 916 known to be positive, 53 reported negative, and 24 reported unknown. Fifty-seven percent (918/1,599) reported receiving monovalent rubella vaccine or trivalent measles-mumps-rubella vaccine. Multiple logistic regression analysis revealed the following to be independent predictors of positive immune status among respondents: female gender (odds ratio [OR], 2.4; 95% confidence interval [CI95], 1.8-3.1), medical school graduation since 1980 (OR, 2.6; CI95, 2.0-3.3), providing obstetric or fertility services (OR, 1.5; CI95, 1.2-1.9), and group practice setting (> or = 5 physicians; OR, 1.2; CI95, 1.1-1.4). CONCLUSIONS: Nationally, nearly one of every five practicing obstetricians may not have documented rubella immunity, and the majority of office-based practices have no system for assuring such immunity. Rubella immunity should extend beyond the hospital setting, with consideration for requiring rubella immunity as a condition for employment. Methods for effective implementation and documentation of current guidelines need to be addressed, particularly in the office setting.     

Circulating vascular cell adhesion molecule-1 (VCAM-1) in atherosclerotic NIDDM patients

Vascular cell adhesion molecule-1 (VCAM-1) has been shown to be highly expressed in atherosclerotic lesions. Although the soluble form of VCAM-1 (sVCAM-1) is detected in human sera, the relation between the degree of atherosclerosis and serum sVCAM-1 level has not been defined. In the present study, sVCAM-1 concentrations were measured in sera from 101 Japanese NIDDM patients. The mean +/- SD serum sVCAM-1 concentration in 26 patients with symptomatic atherosclerotic vascular diseases (789 +/- 187 ng/ml) was higher than that in 75 patients without the disease (664 +/- 175 ng/ml). Among the 101 NIDDM patients, 56 had atherosclerotic change of the carotid arteries, based on the evaluation by high-resolution B-mode ultrasonography. Their sVCAM-1 level was 759 +/- 201 ng/ml, higher than that in 45 patients without any detectable atherosclerosis of the carotid arteries (619 +/- 130 ng/ml). In addition, there was a positive correlation between sVCAM-1 concentration and thickness of the intimal plus medial complex (IMT) of the carotid arteries in the NIDDM patients (r = 0.41, P < 0.0001). Multivariate regression analysis revealed significant predictors of mean IMT value to be sVCAM-1 concentration (F = 62.88, P = 0.0001) and age (F = 9.59, P = 0.0026). By contrast, sVCAM-1 concentration was not increased in nondiabetic patients with atherosclerotic change of the carotid arteries (668 +/- 191 ng/ml; n = 36) compared with those without the atherosclerotic change (632 +/- 177 ng/ml; n = 28), and there was no correlation between sVCAM-1 level and IMT of the carotid arteries in the nondiabetic subjects. These results indicate that circulating sVCAM-1 may be a marker of atherosclerotic lesions in NIDDM patients with symptomatic and asymptomatic atherosclerosis.     

An ecological perspective on smoking among Asian American college students: The roles of social smoking and smoking motives.

Using electronic diaries, the present study examined the roles of social smoking and smoking motives in relation to cigarette use patterns among Asian American college smokers. Multilevel modeling results showed that participants smoked more cigarettes when smoking with peers than when smoking alone. Participants' coping (but not social) motives moderated the within-person associations between smoking with peers and the cigarettes smoked during a smoking episode. The findings support the utility of an ecological perspective in examining the dynamic interaction between smoking motives and the social settings of cigarette use, and call for further research on the social smoking behaviors in diverse populations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ubiquitous Memories: a memory externalization system using physical objects

In this paper we propose an object-triggered human memory augmentation system named “Ubiquitous Memories” that enables a user to directly associate his/her experience data with physical objects by using a “touching” operation. A user conceptually encloses his/her experiences gathered through sense organs into physical objects by simply touching an object. The user can also disclose and re-experience for himself/herself the experiences accumulated in an object by the same operation. We implemented a prototype system composed basically of a radio frequency identification (RFID) device. Physical objects are also attached to RFID tags. We conducted two experiments. The first experiment confirms a succession of the “encoding specificity principle,” which is well known in the research field of psychology, to the Ubiquitous Memories system. The second experiment aims at a clarification of the system’s characteristics by comparing the system with other memory externalization strategies. The results show the Ubiquitous Memories system is effective for supporting memorization and recollection of contextual events.