Graphene-Based Electromechanical Thermal Switches

Thermal management is an important challenge in modern electronics, avionics, automotive, and energy storage systems. While passive thermal solutions (like heat sinks or heat spreaders) are often used, actively modulating heat flow (e.g. via thermal switches or diodes) would offer additional degrees of control over the management of thermal transients and system reliability. Here we report the first thermal switch based on a flexible, collapsible graphene membrane, with low operating voltage, < 2 V. We also employ active-mode scanning thermal microscopy (SThM) to measure the device behavior and switching in real time. A compact analytical thermal model is developed for the general case of a thermal switch based on a double-clamped suspended membrane, highlighting the thermal and electrical design challenges. System-level modeling demonstrates the thermal trade-offs between modulating temperature swing and average temperature as a function of switching ratio. These graphene-based thermal switches present new opportunities for active control of fast (even nanosecond) thermal transients in densely integrated systems

The effectiveness of acupressure for the control and management of chemotherapy-related acute and delayed nausea:a randomized controlled trial

CONTEXT: Both positive and negative results have been reported in the literature from the use of acupressure at the P6 point, providing evidence of highly suggestive but not conclusive results. OBJECTIVES: To clarify whether acupressure is effective in the management of chemotherapy-related nausea and vomiting. METHODS: A randomized, three-group, sham-controlled trial was designed. Patients with cancer receiving chemotherapy were randomized to receive standardized antiemetics and acupressure wristbands, sham acupressure wristbands, or antiemetics alone. Primary outcome assessment (nausea) was carried out daily for seven days per chemotherapy cycle over four cycles. Secondary outcomes included vomiting, psychological distress, and quality of life. RESULTS: Five hundred patients were randomized. Primary outcome analysis (nausea in Cycle 1) revealed no statistically significant differences between the three groups, although nausea levels in the proportion of patients using wristbands (both real and sham) were somewhat lower than those in the proportion of patients using antiemetics-only group. Adjusting for gender, age, and emetic risk of chemotherapy, the odds ratio of lower nausea experience was 1.18 and 1.42 for the acupressure and sham acupressure groups, respectively. A gender interaction effect was evident (P = 0.002). No significant differences were detected in relation to vomiting, anxiety, and quality-of-life measures. CONCLUSION: No clear recommendations can be made about the use of acupressure wristbands in the management of chemotherapy-related nausea and vomiting as results did not reach statistical significance. However, the study provided evidence of encouraging signals in relation to improved nausea experience and warrants further consideration in both practice and further clinical trials. TRIAL REGISTRATION: This trial is registered with the ISRCT register, number ISRCTN87604299

Comparing American Indian/alaska Native Adolescent Daughters\u27 and Their Mothers\u27 Awareness, Knowledge, Attitudes, and Behaviors Regarding Risk for Gestational Diabetes: Implications for Mother-Daughter Communication on Reproductive Health

Purpose: The purpose of the study was to describe, compare, and examine associations at baseline of reproductive health awareness, knowledge, health beliefs, communication and behaviors related to gestational diabetes (GDM) and GDM risk reduction in a vulnerable population of both American Indian/Alaska Native (AIAN) adolescent girls and their mothers. Methods: Descriptive/comparative/correlational analyses examined multitribal baseline data on 149 mother-daughter (M-D) dyads (N = 298; daughter age = 12-24 years) enrolled in a longitudinal study to adapt and evaluate a culturally relevant diabetes preconception counseling (PC) program (Stopping-GDM). The associations between GDM risk reduction awareness, knowledge, health beliefs, and behaviors (eg, daughters’ eating, physical activity, reproductive-health [RH] choices/planning, M-D communication, daughters’ discussions on PC) were examined. Data collected online from 5 national sites. Results: Many M-D lacked awareness/knowledge of GDM and risk reduction. Both M-D were unaware of the girl’s risk for GDM. Mothers’ knowledge and beliefs on GDM prevention/RH were significantly higher than daughters. Younger daughters had greater self-efficacy healthy living. Overall sample reported low to moderate scores for both M-D communication and daughters’ GDM and RH risk-reduction behaviors. Conclusions: Knowledge, communication, and behaviors to prevent GDM were low in AIAN M-D, especially daughters. More than daughters, mothers perceive greater risk of GDM for daughters. Early culturally responsive dyadic PC programs could help decrease risk of developing GDM. Implications for M-D communication is compelling

Body-mass index and cause-specific mortality in 900 000 adults: collaborative analyses of 57 prospective studies

Prospective Studies Collaboration: Gary Whitlock,...K. Jamrozik,..