Long term performance of porous platinum coated neural electrodes.

Over the last several years, there has been a growing interest in neural implants for the study and diagnostics of neurological disorders as well as for the symptomatic treatment of central nervous system related diseases. One of the major challenges is the trade-off between small electrode sizes for high selectivity between single neurons and large electrode-tissue interface areas for excellent stimulation and recording properties. This paper presents an approach of increasing the real surface area of the electrodes by creating a surface microstructure. Two major novelties let this work stand out from existing approaches which mainly make use of porous coatings such as platinum black or iridium oxide, or Poly(3,4-ethylenedioxythiophene) (PEDOT). Roughening is carried out by a dry etching process on the silicon electrode core before being coated by a sputtered platinum layer, eliminating complicated deposition processes as for the materials described above. The technology is compatible with any commonly used coating material. In addition, the surface roughening is compatible with high aspect ratio penetrating electrode arrays such as the well-established Utah electrode array, whose unique geometry presents a challenge in the surface modification of active electrode sites. The dry etching process is well characterized and yields a high controllability of pore size and depth. This paper confirms the superior electrochemical properties including impedance, charge injection capacity, and charge storage capacity of surface engineered electrode arrays compared to conventional arrays over a period of 12 weeks. Furthermore, mechanical stability of the modified electrodes was tested by implantation in the brain of a recently deceased rat. In conclusion, the larger interface surface of the electrodes does not only decrease the impedance which should lead to enhanced Signal to noise ratio (SNR) for recording purposes, but also yields higher charge injection capacities, which improve the stimulation characteristics of the implants.

Social knowledge and social competence: number and quality of strategies as predictors of peer behavior.

The purpose of this study was to examine the ability of two different measures of preschool children's social strategy knowledge to predict classroom behavior with peers. Thirty-two 4- and 5-year-old children attending a university sponsored preschool were administered the Preschool Interpersonal Problem-Solving Tests (PIPS) and an enactive assessment of strategy knowledge. Observational and teacher-rating measures of children's positive and aggressive peer behavior were also obtained. Significant correlations were obtained between (a) the number of strategies produced in the enactive measure and cooperative play ratings by teachers, (b) the number of strategies produced in the PIPS and observations of positive peer behavior, and (c) ratings of friendliness in the PIPS and teacher-rated cooperative play and aggression and observations of aggression. Results are discussed in terms of implications for social skill training.

Mothers' social coaching, mother-child relationship style, and children's peer competence: is the medium the message?

Contributions of mothers' social coaching and responsive style to preschoolers' peer competence were evaluated in 2 studies. In Study 1, 43 mother-child dyads participated in 3 laboratory tasks; videotapes were coded for responsive interaction style in play, advice regarding videotaped peer dilemmas (coaching), and nonsocial teaching in a puzzle task. Coaching and style were largely independent and were correlated with measures of social competence. In Study 2 (n = 62), coaching and style uniquely predicted teacher ratings, but only style predicted peer acceptance. To investigate whether coaching mediated the effects of style and/or whether style moderated the effects of coaching, the samples were combined. No evidence was found for mediation, but coaching was a more powerful predictor of lower levels of boys' aggression when the mother-child relationship was less responsive. Discussion focuses on models of socialization that stress the interplay of general style and specific socialization practices in promoting social competence.

The forgotten vital sign: temperature patterns and associations in 642 trauma patients at an urban level I trauma center.

OBJECTIVES: (1) Identify compliance with the standard of practice that trauma patients have body temperature measurement recorded. (2) Describe the range of temperatures in a sample of trauma patients. (3) Identify associations between temperature and other clinical and trauma variables. DESIGN: Descriptive analysis of a cohort of trauma victims. METHODS: We identified patients with traumatic injuries during a 14-month period with a computer-based trauma registry. Patient charts were reviewed for demographic information, injury data, assessment data, and outcomes. The ED chart, nursing notes, and trauma flow sheets were reviewed in search of a documented temperature assessment. RESULTS: A cohort of 642 trauma patients was identified during the study period. Thirty-two percent were admitted to an ICU; 17% went directly to surgery. The mortality rate was 3.4% (n = 22). Most patients were male (65%), young (mean age, 34 +/- 18 years), and victims of blunt trauma (93%). Seventy-seven percent of patients had a temperature measurement recorded in the emergency department. Patients with minor injuries were more likely to have had their temperature measured (79%) than those with moderate (64%) or severe (64%) injuries (p = 0.0009). Among the 495 patients with recorded temperatures, temperatures ranged from 26.5 degrees to 39 degrees C, with a mean of 36.7 degrees +/- 1.1 degrees C. Ten percent of the patients had temperatures less than 36 degrees C. Temperature correlated negatively with ISS (r = -0.20; p = 0.0001) and positively with RTS (r = 0.37; p < 0.0001). CONCLUSIONS: We conclude that a significant proportion of trauma patients brought to a level I trauma center are hypothermic, with temperatures lower in patients more severely injured and in patients who die. Yet temperature measurement, a simple and standard nursing procedure, is often ignored in trauma resuscitation.

Assessment and related immunization issues in the Special Supplemental Nutrition Program for Women, Infants and Children: a status report.

This article reports the results of a survey undertaken to determine the current level of collaboration between Women, Infants and Children (WIC) programs and immunization services. While the results of this study are encouraging, WIC needs to continue to place emphasis on using written or computerized immunization records for client screening, utilize available computer hardware and software to assist assessments, and expand the use of food voucher incentives as a strategy to improve coverage.

Impact of a large-scale immunization initiative in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC)

CONTEXT: Inner-city immunization rates have lagged behind those in other areas of the country. OBJECTIVE: To evaluate the impact of an initiative linking immunization with distribution of food vouchers in the inner city. DESIGN: Retrospective analysis of immunization data gathered in 1996 and 1997. SETTING: Nineteen Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) sites serving 30% of the Chicago, III, birth cohort. PARTICIPANTS: A total of 16581 children 24 months old or younger. INTERVENTIONS: Voucher incentives (varying frequency of food voucher issuance based on immunization status) and assessment of immunization status and referral to immunization provider. MAIN OUTCOME MEASURES: Age-appropriate immunization rates and WIC enrollment rates. RESULTS: During the 15-month period of evaluation, immunization rates increased from 56% to 89% at sites performing voucher incentives. The proportion of children needing voucher incentives declined from 51% to 12%. Sites performing assessment and referral, but not providing voucher incentives, showed no evidence of improvement in immunization coverage. No difference was observed in enrollment rates between sites performing voucher incentives and those that did not. CONCLUSION: Applied in a large-scale, programmatic fashion, voucher incentives in WIC can rapidly increase and sustain high childhood immunization rates in an inner-city population.