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Sample records for adhering high conductivity

  1. Ten lessons learned from conducting an adherence intervention trial

    PubMed Central

    Lee, Jeannie K; Grace, Karen A; Taylor, Allen J

    2009-01-01

    Clinical practice research provides a unique opportunity to care for a diverse patient population in various health care system settings. Federal study of Adherence to Medications in the Elderly (FAME) was the first prospective observational and randomized controlled trial to implement effective strategies to enhance medication adherence and health outcomes in older patients using polypharmacy. Ten lessons learned from conducting this adherence intervention trial are described: (1) Link the trial to existing clinical work, (2) Begin with a thorough understanding of medication adherence, (3) Ensure that trial highlights individualized intervention, (4) Tailor inclusion criteria and study duration to target population, (5) Employ a range of outcomes linked to meaningful clinical effects, (6) Win the support of the multidisciplinary team and the administration, (7) Promote team work, (8) Consider the potential limitations, (9) Seize the grant opportunities, and (10) Share the findings. PMID:19936150

  2. 7 CFR 1484.34 - Must Cooperators adhere to specific standards of ethical conduct?

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Must Cooperators adhere to specific standards of ethical conduct? 1484.34 Section 1484.34 Agriculture Regulations of the Department of Agriculture... Cooperators adhere to specific standards of ethical conduct? (a) A Cooperator shall conduct its business in...

  3. 7 CFR 1484.34 - Must Cooperators adhere to specific standards of ethical conduct?

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Must Cooperators adhere to specific standards of ethical conduct? 1484.34 Section 1484.34 Agriculture Regulations of the Department of Agriculture... Cooperators adhere to specific standards of ethical conduct? (a) A Cooperator shall conduct its business in...

  4. Adherence to highly active antiretroviral therapy in Hyderabad, India: barriers, facilitators and identification of target groups.

    PubMed

    Dworkin, Mark S; Douglas, G W; Sabitha Rani, G P; Chakraborty, Apurba

    2016-03-01

    We assessed the barriers and facilitators to highly active antiretroviral therapy adherence and determined their prevalence among HIV/AIDS patients in Hyderabad, India. We conducted a cross-sectional study among HIV-infected adults prescribed highly active antiretroviral therapy and receiving care from nine clinics. Depression was screened using Patient Health Questionnaire 9 and facilitators of HIV medication adherence were assessed using an 11-item scale which yielded a total positive attitude to disease score. Prevalence ratios of non-adherence between different categories of potential risk factors were calculated. We compared mean 'facilitators to adherence' scores between the adherent and non-adherent population. Multivariable Poisson regression with robust variance was used to identify independent risk factors. Among the 211 respondents, nearly 20% were non-adherent, approximately 8% had either moderately severe or severe depression and mean score for combined facilitators to medication adherence was 33.35 (±7.88) out of a possible 44 points. Factors significantly associated with non-adherence included older age, female sex worker, moderate-to-severe depression and the combined facilitators to medication adherence score. These data from a broad range of clinical settings in Hyderabad reveal that key groups to focus on for adherence intervention are female sex workers, older persons and those with depression.

  5. High conductivity composite metal

    DOEpatents

    Zhou, Ruoyi; Smith, James L.; Embury, John David

    1998-01-01

    Electrical conductors and methods of producing them, where the conductors possess both high strength and high conductivity. Conductors are comprised of carbon steel and a material chosen from a group consisting of copper, nickel, silver, and gold. Diffusion barriers are placed between these two materials. The components of a conductor are assembled and then the assembly is subjected to heat treating and mechanical deformation steps.

  6. High conductivity composite metal

    DOEpatents

    Zhou, R.; Smith, J.L.; Embury, J.D.

    1998-01-06

    Electrical conductors and methods of producing them are disclosed, where the conductors possess both high strength and high conductivity. Conductors are comprised of carbon steel and a material chosen from a group consisting of copper, nickel, silver, and gold. Diffusion barriers are placed between these two materials. The components of a conductor are assembled and then the assembly is subjected to heat treating and mechanical deformation steps. 10 figs.

  7. Highly Thermal Conductive Nanocomposites

    NASA Technical Reports Server (NTRS)

    Sun, Ya-Ping (Inventor); Connell, John W. (Inventor); Veca, Lucia Monica (Inventor)

    2015-01-01

    Disclosed are methods for forming carbon-based fillers as may be utilized in forming highly thermal conductive nanocomposite materials. Formation methods include treatment of an expanded graphite with an alcohol/water mixture followed by further exfoliation of the graphite to form extremely thin carbon nanosheets that are on the order of between about 2 and about 10 nanometers in thickness. Disclosed carbon nanosheets can be functionalized and/or can be incorporated in nanocomposites with extremely high thermal conductivities. Disclosed methods and materials can prove highly valuable in many technological applications including, for instance, in formation of heat management materials for protective clothing and as may be useful in space exploration or in others that require efficient yet light-weight and flexible thermal management solutions.

  8. 7 CFR 1484.34 - Must Cooperators adhere to specific standards of ethical conduct?

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Must Cooperators adhere to specific standards of ethical conduct? 1484.34 Section 1484.34 Agriculture Regulations of the Department of Agriculture... specific standards of ethical conduct? (a) A Cooperator shall conduct its business in accordance with the...

  9. 7 CFR 1484.34 - Must Cooperators adhere to specific standards of ethical conduct?

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Must Cooperators adhere to specific standards of ethical conduct? 1484.34 Section 1484.34 Agriculture Regulations of the Department of Agriculture... specific standards of ethical conduct? (a) A Cooperator shall conduct its business in accordance with the...

  10. 7 CFR 1484.34 - Must Cooperators adhere to specific standards of ethical conduct?

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Must Cooperators adhere to specific standards of ethical conduct? 1484.34 Section 1484.34 Agriculture Regulations of the Department of Agriculture... specific standards of ethical conduct? (a) A Cooperator shall conduct its business in accordance with the...

  11. High conductance surge cable

    DOEpatents

    Murray, M.M.; Wilfong, D.H.; Lomax, R.E.

    1998-12-08

    An electrical cable for connecting transient voltage surge suppressors to electrical power panels. A strip of electrically conductive foil defines a longitudinal axis, with a length of an electrical conductor electrically attached to the metallic foil along the longitudinal axis. The strip of electrically conductive foil and the length of an electrical conductor are covered by an insulating material. For impedance matching purposes, triangular sections can be removed from the ends of the electrically conductive foil at the time of installation. 6 figs.

  12. High conductance surge cable

    DOEpatents

    Murray, Matthew M.; Wilfong, Dennis H.; Lomax, Ralph E.

    1998-01-01

    An electrical cable for connecting transient voltage surge suppressers to ectrical power panels. A strip of electrically conductive foil defines a longitudinal axis, with a length of an electrical conductor electrically attached to the metallic foil along the longitudinal axis. The strip of electrically conductive foil and the length of an electrical conductor are covered by an insulating material. For impedance matching purposes, triangular sections can be removed from the ends of the electrically conductive foil at the time of installation.

  13. Highly elastic conductive polymeric MEMS

    PubMed Central

    Ruhhammer, J; Zens, M; Goldschmidtboeing, F; Seifert, A; Woias, P

    2015-01-01

    Polymeric structures with integrated, functional microelectrical mechanical systems (MEMS) elements are increasingly important in various applications such as biomedical systems or wearable smart devices. These applications require highly flexible and elastic polymers with good conductivity, which can be embedded into a matrix that undergoes large deformations. Conductive polydimethylsiloxane (PDMS) is a suitable candidate but is still challenging to fabricate. Conductivity is achieved by filling a nonconductive PDMS matrix with conductive particles. In this work, we present an approach that uses new mixing techniques to fabricate conductive PDMS with different fillers such as carbon black, silver particles, and multiwalled carbon nanotubes. Additionally, the electrical properties of all three composites are examined under continuous mechanical stress. Furthermore, we present a novel, low-cost, simple three-step molding process that transfers a micro patterned silicon master into a polystyrene (PS) polytetrafluoroethylene (PTFE) replica with improved release features. This PS/PTFE mold is used for subsequent structuring of conductive PDMS with high accuracy. The non sticking characteristics enable the fabrication of delicate structures using a very soft PDMS, which is usually hard to release from conventional molds. Moreover, the process can also be applied to polyurethanes and various other material combinations. PMID:27877753

  14. Highly elastic conductive polymeric MEMS

    NASA Astrophysics Data System (ADS)

    Ruhhammer, J.; Zens, M.; Goldschmidtboeing, F.; Seifert, A.; Woias, P.

    2015-02-01

    Polymeric structures with integrated, functional microelectrical mechanical systems (MEMS) elements are increasingly important in various applications such as biomedical systems or wearable smart devices. These applications require highly flexible and elastic polymers with good conductivity, which can be embedded into a matrix that undergoes large deformations. Conductive polydimethylsiloxane (PDMS) is a suitable candidate but is still challenging to fabricate. Conductivity is achieved by filling a nonconductive PDMS matrix with conductive particles. In this work, we present an approach that uses new mixing techniques to fabricate conductive PDMS with different fillers such as carbon black, silver particles, and multiwalled carbon nanotubes. Additionally, the electrical properties of all three composites are examined under continuous mechanical stress. Furthermore, we present a novel, low-cost, simple three-step molding process that transfers a micro patterned silicon master into a polystyrene (PS) polytetrafluoroethylene (PTFE) replica with improved release features. This PS/PTFE mold is used for subsequent structuring of conductive PDMS with high accuracy. The non sticking characteristics enable the fabrication of delicate structures using a very soft PDMS, which is usually hard to release from conventional molds. Moreover, the process can also be applied to polyurethanes and various other material combinations.

  15. The adherence/resource priming paradigm – a randomised clinical trial conducting a bonafide psychotherapy protocol for generalised anxiety disorder

    PubMed Central

    2014-01-01

    Background Bonafide psychotherapy is an effective treatment for generalised anxiety disorder compared to no-treatment. Rather than creating increasing numbers of new overall treatment-packets within a medical meta-model, an additional approach to investigating clinical research designs may be to increase the understanding of already effective psychotherapies. Treatment manuals and protocols allow a relatively high degree of freedom for the way therapists implement the overall treatment manuals. There is a systematic lack of knowledge on how therapists should customise these overall protocols. The present study experimentally examines three ways of conducting a bonafide psychotherapy based on a 15 session time-limited cognitive-behavioural therapy (CBT) protocol and their relation to the therapists’ protocol adherence and treatment efficacy. Methods/design This trial will investigate three different methods of customising a bonafide CBT-protocol using dyadic peer-tutoring methodology (primings). The individuals with GAD will be randomly assigned to one of three priming conditions (resource priming, supportive resource priming, or adherence priming). The participant treatment allocation will be performed randomly. Therapists will be assigned to a peer-tutoring partner and priming condition based on a mutual agreement. Treatment outcomes will be assessed at the following times: observer based in-session outcomes, session-by-session post-session outcomes, treatment outcome at post assessment and treatment outcome at 6-month follow-up. Discussion The proposed trial addresses the clinically relevant question of how to customise a bonafide psychotherapy protocol using tandem peer-tutoring methodology (three priming conditions). Through the development and testing of the proposed priming procedures, this study describes levels of adherence and how to conduct an overall treatment protocol in a more systematised way. Trial registration From ClinicalTrials.gov Identifier

  16. Adherence to highly active antiretroviral therapy in HIV-infected inmates.

    PubMed

    Inés, Sandra M; Moralejo, Leticia; Marcos, Miguel; Fuertes, Aurelio; Luna, Guillermo

    2008-03-01

    Adherence to highly active antiretroviral therapy (HAART) has been scarcely studied in correctional settings. Our study aims to evaluate the relationship between adherence and virological outcome and to determine factors related to adherence in correctional settings. A cross-sectional retrospective study was performed in Topas prison (Salamanca, Spain). 50 inmates starting HAART were studied. Adherence was estimated through a self-report questionnaire and variables related to adherence (covering individual factors, the illness itself and the therapeutic regimen) were recorded. HIV-RNA levels and CD4 lymphocyte count were measured before starting therapy and six months after. Statistical analysis was performed using univariate and multivariate methods. 21 inmates (42%) were considered adherent and 29 (58%) were non-adherent. Adherence to treatment, as measured by our questionnaire, was the only significant and independent factor associated with an undetectable viral load at six months of therapy. Five variables were significantly associated with adherence to treatment, four of them as predictor factors for good adherence: an active occupation inside prison, the absence of HIV-related symptoms, a good or average acceptance of treatment, and a higher academic background; previous injection drug use as a risk factor for HIV transmission was associated with non-adherence. A simple self-report questionnaire may be useful for assessing adherence in prison inmates. Recognizing variables associated with adherence is essential to identify prisoners at high risk of being non-adherents in order to develop strategies for improving compliance.

  17. High-Thermal-Conductivity Fabrics

    NASA Technical Reports Server (NTRS)

    Chibante, L. P. Felipe

    2012-01-01

    Heat management with common textiles such as nylon and spandex is hindered by the poor thermal conductivity from the skin surface to cooling surfaces. This innovation showed marked improvement in thermal conductivity of the individual fibers and tubing, as well as components assembled from them. The problem is centered on improving the heat removal of the liquid-cooled ventilation garments (LCVGs) used by astronauts. The current design uses an extensive network of water-cooling tubes that introduces bulkiness and discomfort, and increases fatigue. Range of motion and ease of movement are affected as well. The current technology is the same as developed during the Apollo program of the 1960s. Tubing material is hand-threaded through a spandex/nylon mesh layer, in a series of loops throughout the torso and limbs such that there is close, form-fitting contact with the user. Usually, there is a nylon liner layer to improve comfort. Circulating water is chilled by an external heat exchanger (sublimator). The purpose of this innovation is to produce new LCVG components with improved thermal conductivity. This was addressed using nanocomposite engineering incorporating high-thermalconductivity nanoscale fillers in the fabric and tubing components. Specifically, carbon nanotubes were added using normal processing methods such as thermoplastic melt mixing (compounding twin screw extruder) and downstream processing (fiber spinning, tubing extrusion). Fibers were produced as yarns and woven into fabric cloths. The application of isotropic nanofillers can be modeled using a modified Nielsen Model for conductive fillers in a matrix based on Einstein s viscosity model. This is a drop-in technology with no additional equipment needed. The loading is limited by the ability to maintain adequate dispersion. Undispersed materials will plug filtering screens in processing equipment. Generally, the viscosity increases were acceptable, and allowed the filled polymers to still be

  18. The value of high adherence to tamoxifen in women with breast cancer: a community-based cohort study.

    PubMed

    McCowan, C; Wang, S; Thompson, A M; Makubate, B; Petrie, D J

    2013-09-03

    Low adherence to adjuvant tamoxifen is associated with worse health outcomes but little is known about the cost-effectiveness of high adherence. We conducted an economic evaluation using data for all women with incident breast cancer between 1993 and 2000 who were subsequently prescribed tamoxifen in the Tayside region of Scotland. Patient-level, lifetime Markov models evaluated the impact of high vs low adherence to tamoxifen using linked prescribing, cancer registry, clinical cancer audit, hospital discharge and death records. Direct medical costs were estimated for each patient and quality-of-life weights were assigned. Recurrence information was collected by case note review and adherence calculated from prescribing records with low adherence classed below 80%. A total of 354 (28%) patients had a recorded recurrence and 504 (39%) died. Four hundred and seventy-five (38%) patients had low adherence over the treatment period, which was associated with reduced time to recurrence of 52% (P<0.001). Time to other cause mortality was also reduced by 23% (P=0.055) but this was not statistically significant. For an average patient over her lifetime, low adherence was associated with a loss of 1.43 (95% CI: 1.15-1.71) discounted life years or 1.12 (95% CI: 0.91-1.34) discounted quality-adjusted life years (QALYs) and increased discounted medical costs of £5970 (95% CI: £4644-£7372). Assuming a willingness to pay threshold of £25,000 per QALY, the expected value of changing a patient from low to high adherence is £33,897 (95% CI: £28,322-£39,652). Patients with low adherence have shorter time to recurrence, increased medical costs and worse quality of life. Interventions that encourage patients to continue taking their treatment on a daily basis for the recommended 5-year period may be highly cost-effective.

  19. Calibration-free electrical conductivity measurements for highly conductive slags

    SciTech Connect

    MACDONALD,CHRISTOPHER J.; GAO,HUANG; PAL,UDAY B.; VAN DEN AVYLE,JAMES A.; MELGAARD,DAVID K.

    2000-05-01

    This research involves the measurement of the electrical conductivity (K) for the ESR (electroslag remelting) slag (60 wt.% CaF{sub 2} - 20 wt.% CaO - 20 wt.% Al{sub 2}O{sub 3}) used in the decontamination of radioactive stainless steel. The electrical conductivity is measured with an improved high-accuracy-height-differential technique that requires no calibration. This method consists of making continuous AC impedance measurements over several successive depth increments of the coaxial cylindrical electrodes in the ESR slag. The electrical conductivity is then calculated from the slope of the plot of inverse impedance versus the depth of the electrodes in the slag. The improvements on the existing technique include an increased electrochemical cell geometry and the capability of measuring high precision depth increments and the associated impedances. These improvements allow this technique to be used for measuring the electrical conductivity of highly conductive slags such as the ESR slag. The volatilization rate and the volatile species of the ESR slag measured through thermogravimetric (TG) and mass spectroscopy analysis, respectively, reveal that the ESR slag composition essentially remains the same throughout the electrical conductivity experiments.

  20. Evaluation of adherence to highly active antiretroviral therapy in adults in Jamaica.

    PubMed

    Harvey, K M; Carrington, D; Duncan, J; Figueroa, J P; Hirschorn, L; Manning, D; Jackson, S

    2008-06-01

    Highly active antiretroviral therapy (HAART) has improved morbidity and mortality and quality of life, revitalized communities and transformed the perception of HIV/AIDS from being a "death sentence" to a chronic illness. Strict and sustained adherence to medication is essential long-term viral suppression. In April 2005, an Adherence Support Programme was introduced to Jamaica's HIV Programme, whereby Persons Living with HIV/AIDS (PLWHA) who had achieved high levels of adherence were trained to provide support to other PLWHA in order to increase their adherence to HAART regimens. A cross-sectional survey of 116 individuals with advanced HIV and on HAART was performed in June and July 2006. Many participants were unemployed, poor persons with limited education. Based on self-report of seven-day adherence, 54.8% of persons were 95-100% adherent, 37.5% were 80-94% adherent and 7.7% were < 80% adherent. Having interacted with an adherence counsellor was not associated with adherence levels. Factors associated with nonadherence were: being away from home (38%), sleeping through dose-time (37%), forgetfulness (37%) and running out of pills (31%). Having no food (26.9%), not wanting to be seen taking medication (200%) and intolerable side effects (18.8%) were also reasons given. Only 44% of persons used aids to remind them of dose times. Adherence in this study group is low and may have worsened since 2005. More emphasis must be placed on preparing adults to start HAART The use of pillboxes and other reminders such as alarm clocks and cell phones must be reinforced.

  1. The value of high adherence to tamoxifen in women with breast cancer: a community-based cohort study

    PubMed Central

    McCowan, C; Wang, S; Thompson, A M; Makubate, B; Petrie, D J

    2013-01-01

    Background: Low adherence to adjuvant tamoxifen is associated with worse health outcomes but little is known about the cost-effectiveness of high adherence. Methods: We conducted an economic evaluation using data for all women with incident breast cancer between 1993 and 2000 who were subsequently prescribed tamoxifen in the Tayside region of Scotland. Patient-level, lifetime Markov models evaluated the impact of high vs low adherence to tamoxifen using linked prescribing, cancer registry, clinical cancer audit, hospital discharge and death records. Direct medical costs were estimated for each patient and quality-of-life weights were assigned. Recurrence information was collected by case note review and adherence calculated from prescribing records with low adherence classed below 80%. Results: A total of 354 (28%) patients had a recorded recurrence and 504 (39%) died. Four hundred and seventy-five (38%) patients had low adherence over the treatment period, which was associated with reduced time to recurrence of 52% (P<0.001). Time to other cause mortality was also reduced by 23% (P=0.055) but this was not statistically significant. For an average patient over her lifetime, low adherence was associated with a loss of 1.43 (95% CI: 1.15–1.71) discounted life years or 1.12 (95% CI: 0.91–1.34) discounted quality-adjusted life years (QALYs) and increased discounted medical costs of £5970 (95% CI: £4644–£7372). Assuming a willingness to pay threshold of £25 000 per QALY, the expected value of changing a patient from low to high adherence is £33 897 (95% CI: £28 322–£39 652). Conclusion: Patients with low adherence have shorter time to recurrence, increased medical costs and worse quality of life. Interventions that encourage patients to continue taking their treatment on a daily basis for the recommended 5-year period may be highly cost-effective. PMID:23949153

  2. High frequency conductivity in carbon nanotubes

    SciTech Connect

    Abukari, S. S. Mensah, S. Y.; Twum, A.; Mensah, N. G.; Adu, K. A.; Rabiu, M.

    2012-12-15

    We report on theoretical analysis of high frequency conductivity in carbon nanotubes. Using the kinetic equation with constant relaxation time, an analytical expression for the complex conductivity is obtained. The real part of the complex conductivity is initially negative at zero frequency and become more negative with increasing frequency, until it reaches a resonance minimum at ω ∼ ω{sub B} for metallic zigzag CNs and ω < ω{sub B} for armchair CNs. This resonance enhancement is indicative for terahertz gain without the formation of current instabilities induced by negative dc conductivity. We noted that due to the high density of states of conduction electrons in metallic zigzag carbon nanotubes and the specific dispersion law inherent in hexagonal crystalline structure result in a uniquely high frequency conductivity than the corresponding values for metallic armchair carbon nanotubes. We suggest that this phenomenon can be used to suppress current instabilities that are normally associated with a negative dc differential conductivity.

  3. Comparison of the weight loss and adherence of nine different polyimide films thermally aged at 315 C and 350 C in air. [high temperature lubricants

    NASA Technical Reports Server (NTRS)

    Fusaro, R. L.

    1980-01-01

    Thermal exposure experiments at 315 and 350 C were performed in air on nine different types of polyimides applied to thin 304 stainless steel foils. The tests were conducted to determine which polyimide was the most thermally stable and adherent when subjected to long exposure times at elevated temperatures. One polyimide designated PIC-7 was found to be more thermally stable than the others; however, it did not possess the adherent properties of PIC-2 and PIC-5. It was concluded that as far as thermal stability and adherence are concerned, five of the polyimides are more suitable for high temperature applications than the other four.

  4. High-frequency conductivity of photoionized plasma

    SciTech Connect

    Anakhov, M. V.; Uryupin, S. A.

    2016-08-15

    The tensor of the high-frequency conductivity of a plasma created via tunnel ionization of atoms in the field of linearly or circularly polarized radiation is derived. It is shown that the real part of the conductivity tensor is highly anisotropic. In the case of a toroidal velocity distribution of photoelectrons, the possibility of amplification of a weak high-frequency field polarized at a sufficiently large angle to the anisotropy axis of the initial nonequilibrium distribution is revealed.

  5. Trying to make things right: adherence work in high-poverty, African American neighborhoods.

    PubMed

    Senteio, Charles; Veinot, Tiffany

    2014-12-01

    Adherence to treatment recommendations for chronic diseases is notoriously low across all patient populations. But African American patients, who are more likely to live in low-income neighborhoods and to have multiple chronic conditions, are even less likely to follow medical recommendations. Yet we know little about their contextually embedded, adherence-related experiences. We interviewed individuals (n = 37) with at least two of the following conditions: hypertension, diabetes, and chronic kidney disease. Using an "invisible work" theoretical framework, we outline the adherence work that arose in patients' common life circumstances. We found five types: constantly searching for better care, stretching medications, eating what I know, keeping myself alive, and trying to make it right. Adherence work was effortful, challenging, and addressed external contingencies present in high-poverty African American neighborhoods. This work was invisible within the health care system because participants lacked ongoing, trusting relationships with providers and rarely discussed challenges with them.

  6. High Thermal Conductivity Carbon/Carbon Composites.

    DTIC Science & Technology

    1995-09-30

    The objective of this project was to develop a lowcost, high thermal conductivity carbon/carbon composite with a mesophase pitch -based matrix. A low...carbonization technique and heat treatment of the mesophase pitch was utilized to enhance composite properties by increasing the composite density...Three different fibers, T300 PAN-based, P55 pitch -based, and an experimental high thermal conductivity mesophase pitch -based, were incorporated as the

  7. Adherence to Vaginal Dilation Following High Dose Rate Brachytherapy for Endometrial Cancer

    SciTech Connect

    Friedman, Lois C.; Abdallah, Rita; Schluchter, Mark; Panneerselvam, Ashok; Kunos, Charles A.

    2011-07-01

    Purpose: We report demographic, clinical, and psychosocial factors associated with adherence to vaginal dilation and describe the sexual and marital or nonmarital dyadic functioning of women following high dose rate (HDR) brachytherapy for endometrial cancer. Methods and Materials: We retrospectively evaluated women aged 18 years or older in whom early-stage endometrial (IAgr3-IIB) cancers were treated by HDR intravaginal brachytherapy within the past 3.5 years. Women with or without a sexual partner were eligible. Patients completed questionnaires by mail or by telephone assessing demographic and clinical variables, adherence to vaginal dilation, dyadic satisfaction, sexual functioning, and health beliefs. Results: Seventy-eight of 89 (88%) eligible women with early-stage endometrial cancer treated with HDR brachytherapy completed questionnaires. Only 33% of patients were adherers, based on reporting having used a dilator more than two times per week in the first month following radiation. Nonadherers who reported a perceived change in vaginal dimension following radiation reported that their vaginas were subjectively smaller after brachytherapy (p = 0.013). Adherers reported more worry about their sex lives or lack thereof than nonadherers (p = 0.047). Patients reported considerable sexual dysfunction following completion of HDR brachytherapy. Conclusions: Adherence to recommendations for vaginal dilator use following HDR brachytherapy for endometrial cancer is poor. Interventions designed to educate women about dilator use benefit may increase adherence. Although sexual functioning was compromised, it is likely that this existed before having cancer for many women in our study.

  8. Adherence to enhanced recovery after surgery protocols across a high-volume gastrointestinal surgical service.

    PubMed

    Hammond, John S; Humphries, Sarah; Simson, Nick; Scrimshaw, Helen; Catton, James; Gornall, Christopher; Maxwell-Armstrong, Charles

    2014-01-01

    Enhanced recovery after surgery (ERAS) has been shown to improve outcomes for patients following gastrointestinal surgery. Data on protocol adherence and how this impacts on outcome are limited. This study examines how protocol adherence changes over time and determines how this impacts on outcome across a large-volume gastrointestinal surgical service. A prospective review of patients eligible for colorectal, liver and oesophagogastric ERAS over two 3-month periods in 2010 and 2011 was performed. End points included: length of stay (LOS), overall protocol adherence, individual modality adherence, reason for pathway deviation and patient outcomes. 172 patients (110 colorectal, 31 liver and 31 oesophagogastric) were evaluated. For each sub-speciality, the introduction of ERAS led to significant reductions in LOS that were sustained for the duration of the study. Adherence was achieved across 60% (colorectal), 75% (liver) and 88% (oesophagogastric) of individual pathway modalities. The major causes of pathway deviation were: post-operative nausea and vomiting (colorectal), pain (liver) and pulmonary complications (oesophagogastric). Large-scale implementation of ERAS at a high-volume centre is feasible and offers many of the benefits demonstrated in controlled trials, but adherence may diminish over time. © 2014 S. Karger AG, Basel

  9. Polyethylene nanofibres with very high thermal conductivities

    NASA Astrophysics Data System (ADS)

    Shen, Sheng; Henry, Asegun; Tong, Jonathan; Zheng, Ruiting; Chen, Gang

    2010-04-01

    Bulk polymers are generally regarded as thermal insulators, and typically have thermal conductivities on the order of 0.1 W m-1 K-1 (ref. 1). However, recent work suggests that individual chains of polyethylene-the simplest and most widely used polymer-can have extremely high thermal conductivity. Practical applications of these polymers may also require that the individual chains form fibres or films. Here, we report the fabrication of high-quality ultra-drawn polyethylene nanofibres with diameters of 50-500 nm and lengths up to tens of millimetres. The thermal conductivity of the nanofibres was found to be as high as ~104 W m-1 K-1, which is larger than the conductivities of about half of the pure metals. The high thermal conductivity is attributed to the restructuring of the polymer chains by stretching, which improves the fibre quality toward an `ideal' single crystalline fibre. Such thermally conductive polymers are potentially useful as heat spreaders and could supplement conventional metallic heat-transfer materials, which are used in applications such as solar hot-water collectors, heat exchangers and electronic packaging.

  10. Polyethylene nanofibres with very high thermal conductivities.

    PubMed

    Shen, Sheng; Henry, Asegun; Tong, Jonathan; Zheng, Ruiting; Chen, Gang

    2010-04-01

    Bulk polymers are generally regarded as thermal insulators, and typically have thermal conductivities on the order of 0.1 W m(-1) K(-1). However, recent work suggests that individual chains of polyethylene--the simplest and most widely used polymer--can have extremely high thermal conductivity. Practical applications of these polymers may also require that the individual chains form fibres or films. Here, we report the fabrication of high-quality ultra-drawn polyethylene nanofibres with diameters of 50-500 nm and lengths up to tens of millimetres. The thermal conductivity of the nanofibres was found to be as high as approximately 104 W m(-1) K(-1), which is larger than the conductivities of about half of the pure metals. The high thermal conductivity is attributed to the restructuring of the polymer chains by stretching, which improves the fibre quality toward an 'ideal' single crystalline fibre. Such thermally conductive polymers are potentially useful as heat spreaders and could supplement conventional metallic heat-transfer materials, which are used in applications such as solar hot-water collectors, heat exchangers and electronic packaging.

  11. Safety, Acceptability and Adherence of Dapivirine Vaginal Ring in a Microbicide Clinical Trial Conducted in Multiple Countries in Sub-Saharan Africa

    PubMed Central

    Nel, Annalene; Bekker, Linda-Gail; Bukusi, Elizabeth; Hellstrӧm, Elizabeth; Kotze, Philip; Louw, Cheryl; Martinson, Francis; Masenga, Gileard; Montgomery, Elizabeth; Ndaba, Nelisiwe; van der Straten, Ariane; van Niekerk, Neliëtte; Woodsong, Cynthia

    2016-01-01

    Background This was the first microbicide trial conducted in Africa to evaluate an antiretroviral-containing vaginal ring as an HIV prevention technology for women. Objectives The trial assessed and compared the safety, acceptability and adherence to product use of a 4-weekly administered vaginal ring containing the antiretroviral microbicide, dapivirine, with a matching placebo ring among women from four countries in sub-Saharan Africa. Methods 280 Healthy, sexually active, HIV-negative women, aged 18 to 40 years were enrolled with 140 women randomised to a dapivirine vaginal ring (25 mg) and 140 women to a matching placebo ring, inserted 4-weekly and used over a 12-week period. Safety was evaluated by pelvic examination, colposcopy, clinical laboratory assessments, and adverse events. Blood samples for determination of plasma concentrations of dapivirine were collected at Weeks 0, 4 and 12. Residual dapivirine levels in returned rings from dapivirine ring users were determined post-trial. Participant acceptability and adherence to ring use were assessed by self-reports. Results No safety concerns or clinically relevant differences were observed between the dapivirine and placebo ring groups. Plasma dapivirine concentrations immediately prior to ring removal were similar after removal of the first and third ring, suggesting consistent ring use over the 12-week period. No clear relationship was observed between the residual amount of dapivirine in used rings and corresponding plasma concentrations. Self-reported adherence to daily use of the vaginal rings over the 12-week trial period was very high. At the end of the trial, 96% of participants reported that the ring was usually comfortable to wear, and 97% reported that they would be willing to use it in the future if proven effective. Conclusions The dapivirine vaginal ring has a favourable safety and acceptability profile. If proven safe and effective in large-scale trials, it will be an important component of

  12. High electrical conductivity in upper mantle

    NASA Astrophysics Data System (ADS)

    Bell, Peter M.

    In a joint study by geophysicists at two national laboratories, Los Alamos Scientific Laboratory and Lawrence Livermore National Laboratory, it was concluded that upper-mantle rocks may have relatively high electrical conductivity, presumably because of small amounts of carbon situated along grain boundaries. This impurity conductivity is similar to values determined in the laboratory for low-grade oil shale during pyrolysis. The residual char has electrical conductivity of 10-1 to 10-2 S/m, which is as much as 106 greater than the conductivity of unpyrolized low-grade oil shale (T. Shankland and A. Duba, Carbon-enhanced electrical conductivity in rocks (abstract), Eos, 63, 438, 1982). This much is known; the implications follow.

  13. High quality transparent conducting oxide thin films

    DOEpatents

    Gessert, Timothy A.; Duenow, Joel N.; Barnes, Teresa; Coutts, Timothy J.

    2012-08-28

    A transparent conducting oxide (TCO) film comprising: a TCO layer, and dopants selected from the elements consisting of Vanadium, Molybdenum, Tantalum, Niobium, Antimony, Titanium, Zirconium, and Hafnium, wherein the elements are n-type dopants; and wherein the transparent conducting oxide is characterized by an improved electron mobility of about 42 cm.sup.2/V-sec while simultaneously maintaining a high carrier density of .about.4.4e.times.10.sup.20 cm.sup.-3.

  14. Medication Adherence Among Elderly Patients with High Blood Pressure in Gweru, Zimbabwe

    PubMed Central

    Wariva, Elizabeth; Maradzika, Julita

    2014-01-01

    High blood pressure is a global health concern which is mainly managed by taking anti-hypertensive medications. Although medication is available to control high blood pressure, adhering to treatment is a major problem among hypertensive patients. The purpose of the study was to assess the predisposing, enabling and reinforcing factors to medication adherence among hypertensive patients in Gweru urban aged 40-70 years. A descriptive cross sectional study was used with a sample size of 110 conveniently sampled hypertensive patients. We used an interviewer administered questionnaire designed using phase 4 of the PRECEDE model. The modal age was 70 years and mean age was 58 years (SD=10.29). There were 61.8% females and 38.2% males. Variables associated with medication adherence were: age (P=0.0059), marital status (P=0.015), average monthly income (P=0.0002), support group (P=0.027) and knowledge (P=0.0058). Providing information to patients with high blood pressure and having a good patient-provider relationship improves medication adherence. There is need to focus on the predisposing, enabling and reinforcing factors of medication adherence since demographic and socio-economic factors may be more difficult to change.

  15. High Adherence Is Necessary to Realize Health Gains from Water Quality Interventions

    PubMed Central

    Brown, Joe; Clasen, Thomas

    2012-01-01

    Background Safe drinking water is critical for health. Household water treatment (HWT) has been recommended for improving access to potable water where existing sources are unsafe. Reports of low adherence to HWT may limit the usefulness of this approach, however. Methods and Findings We constructed a quantitative microbial risk model to predict gains in health attributable to water quality interventions based on a range of assumptions about pre-treatment water quality; treatment effectiveness in reducing bacteria, viruses, and protozoan parasites; adherence to treatment interventions; volume of water consumed per person per day; and other variables. According to mean estimates, greater than 500 DALYs may be averted per 100,000 person-years with increased access to safe water, assuming moderately poor pre-treatment water quality that is a source of risk and high treatment adherence (>90% of water consumed is treated). A decline in adherence from 100% to 90% reduces predicted health gains by up to 96%, with sharpest declines when pre-treatment water quality is of higher risk. Conclusions Results suggest that high adherence is essential in order to realize potential health gains from HWT. PMID:22586491

  16. An Innovative High Thermal Conductivity Fuel Design

    SciTech Connect

    PI: James S. Tulenko; Co-PI: Ronald H. Baney,

    2007-10-14

    Uranium dioxide (UO2) is the most common fuel material in commercial nuclear power reactors. UO2 has the advantages of a high melting point, good high-temperature stability, good chemical compatibility with cladding and coolant, and resistance to radiation. The main disadvantage of UO2 is its low thermal conductivity. During a reactor’s operation, because the thermal conductivity of UO2 is very low, for example, about 2.8 W/m-K at 1000 oC [1], there is a large temperature gradient in the UO2 fuel pellet, causing a very high centerline temperature, and introducing thermal stresses, which lead to extensive fuel pellet cracking. These cracks will add to the release of fission product gases after high burnup. The high fuel operating temperature also increases the rate of fission gas release and the fuel pellet swelling caused by fission gases bubbles. The amount of fission gas release and fuel swelling limits the life time of UO2 fuel in reactor. In addition, the high centerline temperature and large temperature gradient in the fuel pellet, leading to a large amount of stored heat, increase the Zircaloy cladding temperature in a lost of coolant accident (LOCA). The rate of Zircaloy-water reaction becomes significant at the temperature above 1200 oC [2]. The ZrO2 layer generated on the surface of the Zircaloy cladding will affect the heat conduction, and will cause a Zircaloy cladding rupture. The objective of this research is to increase the thermal conductivity of UO2, while not affecting the neutronic property of UO2 significantly. The concept to accomplish this goal is to incorporate another material with high thermal conductivity into the UO2 pellet. Silicon carbide (SiC) is a good candidate, because the thermal conductivity of single crystal SiC is 60 times higher than that of UO2 at room temperature and 30 times higher at 800 oC [3]. Silicon carbide also has the properties of low thermal neutron absorption cross section, high melting point, good chemical

  17. A highly stretchable, transparent, and conductive polymer

    DOE PAGES

    Wang, Yue; Zhu, Chenxin; Pfattner, Raphael; ...

    2017-03-10

    Previous breakthroughs in stretchable electronics stem from strain engineering and nanocomposite approaches. Routes toward intrinsically stretchable molecular materials remain scarce but, if successful, will enable simpler fabrication processes, such as direct printing and coating, mechanically robust devices, and more intimate contact with objects. We report a highly stretchable conducting polymer, realized with a range of enhancers that serve a dual function: (i) they change morphology and (ii) they act as conductivity-enhancing dopants in poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). The polymer films exhibit conductivities comparable to the best reported values for PEDOT:PSS, with over 3100 S/cm under 0% strain and over 4100 S/cm undermore » 100% strain—among the highest for reported stretchable conductors. It is highly durable under cyclic loading, with the conductivity maintained at 3600 S/cm even after 1000 cycles to 100% strain. The conductivity remained above 100 S/cm under 600% strain, with a fracture strain of 800%, which is superior to even the best silver nanowire– or carbon nanotube–based stretchable conductor films. As a result, the combination of excellent electrical and mechanical properties allowed it to serve as interconnects for field-effect transistor arrays with a device density that is five times higher than typical lithographically patterned wavy interconnects.« less

  18. A highly stretchable, transparent, and conductive polymer

    PubMed Central

    Wang, Yue; Zhu, Chenxin; Pfattner, Raphael; Yan, Hongping; Jin, Lihua; Chen, Shucheng; Molina-Lopez, Francisco; Lissel, Franziska; Liu, Jia; Rabiah, Noelle I.; Chen, Zheng; Chung, Jong Won; Linder, Christian; Toney, Michael F.; Murmann, Boris; Bao, Zhenan

    2017-01-01

    Previous breakthroughs in stretchable electronics stem from strain engineering and nanocomposite approaches. Routes toward intrinsically stretchable molecular materials remain scarce but, if successful, will enable simpler fabrication processes, such as direct printing and coating, mechanically robust devices, and more intimate contact with objects. We report a highly stretchable conducting polymer, realized with a range of enhancers that serve a dual function: (i) they change morphology and (ii) they act as conductivity-enhancing dopants in poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). The polymer films exhibit conductivities comparable to the best reported values for PEDOT:PSS, with over 3100 S/cm under 0% strain and over 4100 S/cm under 100% strain—among the highest for reported stretchable conductors. It is highly durable under cyclic loading, with the conductivity maintained at 3600 S/cm even after 1000 cycles to 100% strain. The conductivity remained above 100 S/cm under 600% strain, with a fracture strain of 800%, which is superior to even the best silver nanowire– or carbon nanotube–based stretchable conductor films. The combination of excellent electrical and mechanical properties allowed it to serve as interconnects for field-effect transistor arrays with a device density that is five times higher than typical lithographically patterned wavy interconnects. PMID:28345040

  19. A highly stretchable, transparent, and conductive polymer.

    PubMed

    Wang, Yue; Zhu, Chenxin; Pfattner, Raphael; Yan, Hongping; Jin, Lihua; Chen, Shucheng; Molina-Lopez, Francisco; Lissel, Franziska; Liu, Jia; Rabiah, Noelle I; Chen, Zheng; Chung, Jong Won; Linder, Christian; Toney, Michael F; Murmann, Boris; Bao, Zhenan

    2017-03-01

    Previous breakthroughs in stretchable electronics stem from strain engineering and nanocomposite approaches. Routes toward intrinsically stretchable molecular materials remain scarce but, if successful, will enable simpler fabrication processes, such as direct printing and coating, mechanically robust devices, and more intimate contact with objects. We report a highly stretchable conducting polymer, realized with a range of enhancers that serve a dual function: (i) they change morphology and (ii) they act as conductivity-enhancing dopants in poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). The polymer films exhibit conductivities comparable to the best reported values for PEDOT:PSS, with over 3100 S/cm under 0% strain and over 4100 S/cm under 100% strain-among the highest for reported stretchable conductors. It is highly durable under cyclic loading, with the conductivity maintained at 3600 S/cm even after 1000 cycles to 100% strain. The conductivity remained above 100 S/cm under 600% strain, with a fracture strain of 800%, which is superior to even the best silver nanowire- or carbon nanotube-based stretchable conductor films. The combination of excellent electrical and mechanical properties allowed it to serve as interconnects for field-effect transistor arrays with a device density that is five times higher than typical lithographically patterned wavy interconnects.

  20. Psychiatrists’ awareness of adherence to antipsychotic medication in patients with schizophrenia: results from a survey conducted across Europe, the Middle East, and Africa

    PubMed Central

    Olivares, José Manuel; Alptekin, Köksal; Azorin, Jean-Michel; Cañas, Fernando; Dubois, Vincent; Emsley, Robin; Gorwood, Philip; Haddad, Peter M; Naber, Dieter; Papageorgiou, George; Roca, Miquel; Thomas, Pierre; Martinez, Guadalupe; Schreiner, Andreas

    2013-01-01

    Background Nonadherence is common among patients with schizophrenia, although the rates vary according to means of assessment and patient population. Failure to adhere to medication can have a major impact on the course of illness and treatment outcomes, including increasing the risk of relapse and rehospitalization. Understanding psychiatrists’ perception of the causes and consequences of nonadherence is crucial to addressing adherence problems effectively. Methods The Europe, the Middle East, and Africa (EMEA) Spanish Adherencia Terapéutica en la Esquizofrenia (ADHES) survey was conducted by questionnaire during January–March 2010 among psychiatrists treating patients with schizophrenia in 36 countries. The survey comprised 20 questions. In addition to recording the demographic details of the 4722 respondents (~12% response rate), it canvassed their preferred methods of assessing adherence, their perceptions of adherence rates, reasons for nonadherence, and strategies to improve adherence. Results Psychiatrists estimated that 53% of their patients with schizophrenia were partially/nonadherent during the previous month. They estimated only one-third of patients who deteriorated after stopping medication were able to attribute this to nonadherence. Psychiatrists assessed adherence most often by patient interview. Lack of insight was viewed as the most important cause of medication discontinuation, followed by patients feeling better and thinking their medication unnecessary, and experiencing undesirable side effects. Considerably fewer psychiatrists viewed insufficient efficacy, cognitive impairment, or drug/alcohol abuse as the most important reasons for their patients stopping medication. Conclusion Psychiatrists throughout EMEA recognize the impact of partial/nonadherence to medication, with patient enquiry being the most commonly used means of assessment. There remains a need for more proactive management of patients with schizophrenia, particularly in

  1. Psychiatrists' awareness of adherence to antipsychotic medication in patients with schizophrenia: results from a survey conducted across Europe, the Middle East, and Africa.

    PubMed

    Olivares, José Manuel; Alptekin, Köksal; Azorin, Jean-Michel; Cañas, Fernando; Dubois, Vincent; Emsley, Robin; Gorwood, Philip; Haddad, Peter M; Naber, Dieter; Papageorgiou, George; Roca, Miquel; Thomas, Pierre; Martinez, Guadalupe; Schreiner, Andreas

    2013-01-01

    Nonadherence is common among patients with schizophrenia, although the rates vary according to means of assessment and patient population. Failure to adhere to medication can have a major impact on the course of illness and treatment outcomes, including increasing the risk of relapse and rehospitalization. Understanding psychiatrists' perception of the causes and consequences of nonadherence is crucial to addressing adherence problems effectively. The Europe, the Middle East, and Africa (EMEA) Spanish Adherencia Terapéutica en la Esquizofrenia (ADHES) survey was conducted by questionnaire during January-March 2010 among psychiatrists treating patients with schizophrenia in 36 countries. The survey comprised 20 questions. In addition to recording the demographic details of the 4722 respondents (~12% response rate), it canvassed their preferred methods of assessing adherence, their perceptions of adherence rates, reasons for nonadherence, and strategies to improve adherence. Psychiatrists estimated that 53% of their patients with schizophrenia were partially/nonadherent during the previous month. They estimated only one-third of patients who deteriorated after stopping medication were able to attribute this to nonadherence. Psychiatrists assessed adherence most often by patient interview. Lack of insight was viewed as the most important cause of medication discontinuation, followed by patients feeling better and thinking their medication unnecessary, and experiencing undesirable side effects. Considerably fewer psychiatrists viewed insufficient efficacy, cognitive impairment, or drug/alcohol abuse as the most important reasons for their patients stopping medication. Psychiatrists throughout EMEA recognize the impact of partial/nonadherence to medication, with patient enquiry being the most commonly used means of assessment. There remains a need for more proactive management of patients with schizophrenia, particularly in increasing patient insight of their illness

  2. Effect of surface roughness and sterilization on bacterial adherence to ultra-high molecular weight polyethylene.

    PubMed

    Kinnari, T J; Esteban, J; Zamora, N; Fernandez, R; López-Santos, C; Yubero, F; Mariscal, D; Puertolas, J A; Gomez-Barrena, E

    2010-07-01

    Sterilization with ethylene oxide (EO) and gas plasma (GP) are well-known methods applied to ultra-high molecular weight polyethylene (UHMWPE) surfaces in the belief that they prevent major material changes caused by gamma irradiation. However, the influence of these surface sterilization methods on bacterial adherence to UHMWPE is unknown. UHMWPE samples with various degrees of roughness (0.3, 0.8 and 2.0 μm) were sterilized with either GP or EO. The variations in hydrophobicity, surface free energy and surface functional groups were investigated before and after sterilization. Sterilized samples were incubated with either Staphylococcus aureus or Staphylococcus epidermidis in order to study bacterial adherence to these materials. Fewer bacteria adhered to UHMWPE after sterilization with EO than after sterilization with GP, especially to the smoothest surfaces. No changes in chemical composition of the UHMWPE surface due to sterilization were observed using X-ray photoemission spectroscopy analysis. The decreased bacterial adherence to UHMWPE found at the smoothest surfaces after sterilization with EO was not directly related to changes in chemical composition. Increased bacterial adherence to rougher surfaces was associated with increased polar surface energy of EO-sterilized surfaces.

  3. High H- ionic conductivity in barium hydride

    NASA Astrophysics Data System (ADS)

    Verbraeken, Maarten C.; Cheung, Chaksum; Suard, Emmanuelle; Irvine, John T. S.

    2015-01-01

    With hydrogen being seen as a key renewable energy vector, the search for materials exhibiting fast hydrogen transport becomes ever more important. Not only do hydrogen storage materials require high mobility of hydrogen in the solid state, but the efficiency of electrochemical devices is also largely determined by fast ionic transport. Although the heavy alkaline-earth hydrides are of limited interest for their hydrogen storage potential, owing to low gravimetric densities, their ionic nature may prove useful in new electrochemical applications, especially as an ionically conducting electrolyte material. Here we show that barium hydride shows fast pure ionic transport of hydride ions (H-) in the high-temperature, high-symmetry phase. Although some conductivity studies have been reported on related materials previously, the nature of the charge carriers has not been determined. BaH2 gives rise to hydride ion conductivity of 0.2 S cm-1 at 630 °C. This is an order of magnitude larger than that of state-of-the-art proton-conducting perovskites or oxide ion conductors at this temperature. These results suggest that the alkaline-earth hydrides form an important new family of materials, with potential use in a number of applications, such as separation membranes, electrochemical reactors and so on.

  4. Two-step protocol for preparing adherent cells for high-throughput flow cytometry.

    PubMed

    Kaur, Mandeep; Esau, Luke

    2015-09-01

    We have developed a simple, cost-effective, and labor-efficient two-step protocol for preparing adherent cells for high-throughput flow cytometry. Adherent cells were grown on microplates, detached with 2.9 mM EDTA (pH 6.14) added directly to wells containing cell culture medium, stained, and then analyzed on a flow cytometer. This protocol bypasses washing, centrifugation, and transfer between plates, reducing the cell loss that occurs in standard multistep protocols. The method has been validated using six adherent cell lines, four commercially available dyes, and two antibodies; the results have been confirmed using two different flow cytometry (FC) instruments. Our approach has been used for estimating apoptosis, mitochondrial membrane potential, reactive oxygen species, and autophagy in response to exposure to pure compounds as well as plant and bacterial extracts.

  5. High shear flow induces migration of adherent human platelets.

    PubMed

    Kraemer, Bjoern F; Schmidt, Christine; Urban, Benjamin; Bigalke, Boris; Schwanitz, Laura; Koch, Miriam; Seizer, Peter; Schaller, Martin; Gawaz, Meinrad; Lindemann, Stephan

    2011-01-01

    Shear forces are generated in all parts of the vascular system and contribute directly and indirectly to vascular disease progression. Endothelial cells are able to adapt to flow conditions, and are known to polarize and migrate in response to shear forces. Platelets exposed to shear stress are activated and release bioactive molecules from their alpha granules. So far, platelets have been considered to be static cells that do not leave the site of tight adhesion. However, we have recently been able to demonstrate the capacity of platelets to migrate in response to stromal derived factor-1 (SDF-1). In this project, we have demonstrated that platelets accumulate in areas with a high concentration of SDF-1 under flow conditions and respond to high shear stress by cellular polarization, cytoskeletal reorganisation, and flow-directed migration. In this context, we have shown increased Wiskott-Aldrich Syndrome protein (WASP) phosphorylation and intracellular redistribution of focal adhesion kinase (FAK) under high-shear stress conditions. The effect of flow-induced platelet migration has not previously been recognized and offers a new role for platelets as mobile cells. Their migratory potential may enable platelets to cover intimal lesions and contribute to vascular repair.

  6. On the high conductivity of nonconjugated polymers

    SciTech Connect

    Lachinov, A. N. Kornilov, V. M.; Zagurenko, T. G.; Zherebov, A. Yu.

    2006-04-15

    The mechanism of charge transfer in a metal-electroactive polymer-metal structure has been experimentally studied near the threshold of the uniaxial-pressure-induced transition into a high-conductivity state in the polymer. The dynamics of the I-V curve is investigated as a function of the applied pressure. The data obtained are analyzed in terms of the model of injection currents using the concepts of possible scanning of a quasi-Fermi level near an injection level. Our estimates suggest that a narrow band made of deep trap states located near the Fermi level forms in the polymer film in the pretransition pressure range. In the immediate vicinity of the transition range, a narrow band of coherent charge transfer appears from these states; this band can be responsible for the high metal-type conductivity of thin polymer films, which has been repeatedly observed by many researchers.

  7. Highly stretchable electrospun conducting polymer nanofibers

    NASA Astrophysics Data System (ADS)

    Boubée de Gramont, Fanny; Zhang, Shiming; Tomasello, Gaia; Kumar, Prajwal; Sarkissian, Andranik; Cicoira, Fabio

    2017-08-01

    Biomedical electronics research targets both wearable and biocompatible electronic devices easily adaptable to specific functions. To achieve such goals, stretchable organic electronic materials are some of the most intriguing candidates. Herein, we develop highly stretchable poly-(3,4-ethylenedioxythiphene) (PEDOT) doped with tosylate (PEDOT:Tos) nanofibers. A two-step process involving electrospinning of a carrier polymer (with oxidant) and vapor phase polymerization was used to produce fibers on a polydimethylsiloxane substrate. The fibers can be stretched up to 140% of the initial length maintaining high conductivity.

  8. Highly conductive, printable pastes from capillary suspensions

    NASA Astrophysics Data System (ADS)

    Schneider, Monica; Koos, Erin; Willenbacher, Norbert

    2016-08-01

    We have used the capillary suspension phenomenon to design conductive pastes for printed electronic applications, such as front side metallization of solar cells, without non-volatile, organic additives that often deteriorate electrical properties. Adding a small amount of a second, immiscible fluid to a suspension creates a network of liquid bridges between the particles. This capillary force-controlled microstructure allows for tuning the flow behavior in a wide range. Yield stress and low-shear viscosity can be adjusted such that long-term stability is provided by inhibiting sedimentation, and, even more importantly, narrow line widths and high aspect ratios are accessible. These ternary mixtures, called capillary suspensions, exhibit a strong degree of shear thinning that allows for conventional coating or printing equipment to be used. Finally, the secondary fluid, beneficial for stability and processing of the wet paste, completely evaporates during drying and sintering. Thus, we obtained high purity silver and nickel layers with a conductivity two times greater than could be obtained with state-of-the-art, commercial materials. This revolutionary concept can be easily applied to other systems using inorganic or even organic conductive particles and represents a fundamental paradigm change to the formulation of pastes for printed electronics.

  9. Laser patterning of highly conductive flexible circuits.

    PubMed

    Ji, Seok Young; Ajmal, C Muhammed; Kim, Taehun; Chang, Won Seok; Baik, Seunghyun

    2017-04-21

    There has been considerable attention paid to highly conductive flexible adhesive (CFA) materials as electrodes and interconnectors for future flexible electronic devices. However, the patterning technology still needs to be developed to construct micro-scale electrodes and circuits. Here we developed the selective laser sintering technology where the pattering and curing were accomplished simultaneously without making additional masks. The CFA was composed of micro-scale Ag flakes, multiwalled carbon nanotubes decorated with Ag nanoparticles, and a nitrile-butadiene-rubber matrix. The Teflon-coated polyethylene terephthalate film was used as a flexible substrate. The width of lines (50-500 μm) and circuit patterns were controlled by the programmable scanning of a focused laser beam (power = 50 mW, scanning speed = 1 mm s(-1)). The laser irradiation removed solvent and induced effective coalescence among fillers providing a conductivity as high as 25 012 S cm(-1). The conductivity stability was excellent under the ambient air and humid environments. The normalized resistance change of the pattern was smaller than 1.2 at the bending radius of 5 mm. The cyclability and adhesion of the laser-sintered line pattern on the substrate was excellent. A flexible circuit was fabricated sequentially for operating light emitting diodes during the bending motion, demonstrating excellent feasibility for practical applications in flexible electronics.

  10. Highly Conductive Multifunctional Graphene Polycarbonate Nanocomposites

    NASA Technical Reports Server (NTRS)

    Yoonessi, Mitra; Gaier, James R.

    2010-01-01

    Graphene nanosheet bisphenol A polycarbonate nanocomposites (0.027 2.2 vol %) prepared by both emulsion mixing and solution blending methods, followed by compression molding at 287 C, exhibited dc electrical percolation threshold of approx.0.14 and approx.0.38 vol %, respectively. The conductivities of 2.2 vol % graphene nanocomposites were 0.512 and 0.226 S/cm for emulsion and solution mixing. The 1.1 and 2.2 vol % graphene nanocomposites exhibited frequency-independent behavior. Inherent conductivity, extremely high aspect ratio, and nanostructure directed assembly of the graphene using PC nanospheres are the main factors for excellent electrical properties of the nanocomposites. Dynamic tensile moduli of nanocomposites increased with increasing graphene in the nanocomposite. The glass transition temperatures were decreased with increasing graphene for the emulsion series. High-resolution electron microscopy (HR-TEM) and small-angle neutron scattering (SANS) showed isolated graphene with no connectivity path for insulating nanocomposites and connected nanoparticles for the conductive nanocomposites. A stacked disk model was used to obtain the average particle radius, average number of graphene layers per stack, and stack spacing by simulation of the experimental SANS data. Morphology studies indicated the presence of well-dispersed graphene and small graphene stacking with infusion of polycarbonate within the stacks.

  11. Highly conductive, printable pastes from capillary suspensions

    PubMed Central

    Schneider, Monica; Koos, Erin; Willenbacher, Norbert

    2016-01-01

    We have used the capillary suspension phenomenon to design conductive pastes for printed electronic applications, such as front side metallization of solar cells, without non-volatile, organic additives that often deteriorate electrical properties. Adding a small amount of a second, immiscible fluid to a suspension creates a network of liquid bridges between the particles. This capillary force-controlled microstructure allows for tuning the flow behavior in a wide range. Yield stress and low-shear viscosity can be adjusted such that long-term stability is provided by inhibiting sedimentation, and, even more importantly, narrow line widths and high aspect ratios are accessible. These ternary mixtures, called capillary suspensions, exhibit a strong degree of shear thinning that allows for conventional coating or printing equipment to be used. Finally, the secondary fluid, beneficial for stability and processing of the wet paste, completely evaporates during drying and sintering. Thus, we obtained high purity silver and nickel layers with a conductivity two times greater than could be obtained with state-of-the-art, commercial materials. This revolutionary concept can be easily applied to other systems using inorganic or even organic conductive particles and represents a fundamental paradigm change to the formulation of pastes for printed electronics. PMID:27506726

  12. Laser patterning of highly conductive flexible circuits

    NASA Astrophysics Data System (ADS)

    Ji, Seok Young; Muhammed Ajmal, C.; Kim, Taehun; Chang, Won Seok; Baik, Seunghyun

    2017-04-01

    There has been considerable attention paid to highly conductive flexible adhesive (CFA) materials as electrodes and interconnectors for future flexible electronic devices. However, the patterning technology still needs to be developed to construct micro-scale electrodes and circuits. Here we developed the selective laser sintering technology where the pattering and curing were accomplished simultaneously without making additional masks. The CFA was composed of micro-scale Ag flakes, multiwalled carbon nanotubes decorated with Ag nanoparticles, and a nitrile-butadiene-rubber matrix. The Teflon-coated polyethylene terephthalate film was used as a flexible substrate. The width of lines (50-500 μm) and circuit patterns were controlled by the programmable scanning of a focused laser beam (power = 50 mW, scanning speed = 1 mm s-1). The laser irradiation removed solvent and induced effective coalescence among fillers providing a conductivity as high as 25 012 S cm-1. The conductivity stability was excellent under the ambient air and humid environments. The normalized resistance change of the pattern was smaller than 1.2 at the bending radius of 5 mm. The cyclability and adhesion of the laser-sintered line pattern on the substrate was excellent. A flexible circuit was fabricated sequentially for operating light emitting diodes during the bending motion, demonstrating excellent feasibility for practical applications in flexible electronics.

  13. Highly Conductive Multifunctional Graphene Polycarbonate Nanocomposites

    NASA Technical Reports Server (NTRS)

    Yoonessi, Mitra; Gaier, James R.

    2010-01-01

    Graphene nanosheet bisphenol A polycarbonate nanocomposites (0.027 2.2 vol %) prepared by both emulsion mixing and solution blending methods, followed by compression molding at 287 C, exhibited dc electrical percolation threshold of approx.0.14 and approx.0.38 vol %, respectively. The conductivities of 2.2 vol % graphene nanocomposites were 0.512 and 0.226 S/cm for emulsion and solution mixing. The 1.1 and 2.2 vol % graphene nanocomposites exhibited frequency-independent behavior. Inherent conductivity, extremely high aspect ratio, and nanostructure directed assembly of the graphene using PC nanospheres are the main factors for excellent electrical properties of the nanocomposites. Dynamic tensile moduli of nanocomposites increased with increasing graphene in the nanocomposite. The glass transition temperatures were decreased with increasing graphene for the emulsion series. High-resolution electron microscopy (HR-TEM) and small-angle neutron scattering (SANS) showed isolated graphene with no connectivity path for insulating nanocomposites and connected nanoparticles for the conductive nanocomposites. A stacked disk model was used to obtain the average particle radius, average number of graphene layers per stack, and stack spacing by simulation of the experimental SANS data. Morphology studies indicated the presence of well-dispersed graphene and small graphene stacking with infusion of polycarbonate within the stacks.

  14. High Thermal Conductivity Graphite Electronic Components

    NASA Astrophysics Data System (ADS)

    Peck, S. O.; Young, G. L.; Mellberg, W. J.; Wellman, A. F.; Cooney, J. E.

    1996-08-01

    This project will apply high thermal conductivity graphite to three major spacecraft electronic components: (1) the thermal plane of a printed wiring board, (2) the subassembly or tray that holds the board, and (3) the equipment panel that the tray mounts on. The complete heat transfer path from chip level heat source to radiative rejection on the exterior surface of the equipment panel will therefore be addressed. Thermal and structural requirements representative of current spacecraft will drive an optimized solution strategy. The project will be completed by fabricating the three prototypical test articles and measuring their performance in a representative space environment.

  15. Highly Conducting Graphite Epoxy Composite Demonstrated

    NASA Technical Reports Server (NTRS)

    Gaier, James R.

    1999-01-01

    Weight savings as high as 80 percent could be achieved if graphite polymer composites could replace aluminum in structures such as electromagnetic interference shielding covers and grounding planes. This could result in significant cost savings, especially for the mobile electronics found in spacecraft, aircraft, automobiles, and hand-held consumer electronics. However, such composites had not yet been fabricated with conductivity sufficient to enable these applications. To address this lack, a partnership of the NASA Lewis Research Center, Manchester College, and Applied Sciences, Inc., fabricated nonmetallic composites with unprecedented electrical conductivity. For these composites, heat-treated, vapor-grown graphite fibers were selected which have a resistivity of about 80 mW-cm, more than 20 times more conductive than typical carbon fibers. These fibers were then intercalated with iodine bromide (IBr). Intercalation is the insertion of guest atoms or molecules between the carbon planes of the graphite fibers. Since the carbon planes are not highly distorted in the process, intercalation has little effect on mechanical and thermal properties. Intercalation does, however, lower the carbon fiber resistivity to less than 10 mW-cm, which is comparable to that of metal fibers. Scaleup of the reaction was required since the initial intercalation experiments would be carried out on 20-mg quantities of fibers, and tens of grams of intercalated fibers would be needed to fabricate even small demonstration composites. The reaction was first optimized through a time and temperature study that yielded fibers with a resistivity of 8.7 2 mW-cm when exposed to IBr vapor at 114 C for 24 hours. Stability studies indicated that the intercalated fibers rapidly lost their conductivity when exposed to temperatures as low as 40 C in air. They were not, however, susceptible to degradation by water vapor in the manner of most graphite intercalation compounds. The 1000-fold scaleup

  16. Refill non-adherence to repeat prescriptions leads to treatment gaps or to high extra costs.

    PubMed

    Krigsman, Kristin; Melander, Arne; Carlsten, Anders; Ekedahl, Anders; Nilsson, J Lars

    2007-02-01

    To determine the nature and extent of undersupply and the economic consequences of oversupply of medication among non-adherent patients. This study used copies of repeat prescriptions (= multiple dispensations), collected during 1 week in 2002 at 16 Swedish community pharmacies. For patients with a refill adherence below 80%, treatment gaps were defined as the number of days they had no drug available. The cost of drug oversupply (i.e., refill adherence > 120%) was calculated from the prices of the drug packages dispensed. The number of collected repeat prescriptions was 3,636. The median of treatment gaps among patients with a refill adherence below 80% was 53 days per 90-100 days treatment period and the corresponding median for oversupply was 40 days. The cost of oversupply for exempt patients (i.e., patients who have paid 1,800 SEK (Euro 196; US$ 243) per year for medicines) was 32,000 SEK (Euro 3,500; US$ 4,300) higher than for non-exempt patients. An extrapolation to all Sweden indicates that exemption from charges leads to an additional oversupply of about 142 million SEK (Euro 15 million; US$ 19 million) per year above that of non-exempt patients. Both undersupply and oversupply of prescribed medicines are common in Sweden. Patients with a refill adherence below 80% seem to have less than half of the prescribed treatment available. Oversupply or drug stockpiling occurs more frequently among exempt than among non-exempt patients, and this oversupply leads to high unnecessary costs.

  17. Determinants of Medication Adherence to Antihypertensive Medications among a Chinese Population Using Morisky Medication Adherence Scale

    PubMed Central

    Lee, Gabrielle K. Y.; Wang, Harry H. X.; Liu, Kirin Q. L.; Cheung, Yu; Morisky, Donald E.; Wong, Martin C. S.

    2013-01-01

    Background and Objectives Poor adherence to medications is one of the major public health challenges. Only one-third of the population reported successful control of blood pressure, mostly caused by poor drug adherence. However, there are relatively few reports studying the adherence levels and their associated factors among Chinese patients. This study aimed to study the adherence profiles and the factors associated with antihypertensive drug adherence among Chinese patients. Methods A cross-sectional study was conducted in an outpatient clinic located in the New Territories Region of Hong Kong. Adult patients who were currently taking at least one antihypertensive drug were invited to complete a self-administered questionnaire, consisting of basic socio-demographic profile, self-perceived health status, and self-reported medication adherence. The outcome measure was the Morisky Medication Adherence Scale (MMAS-8). Good adherence was defined as MMAS scores greater than 6 points (out of a total score of 8 points). Results From 1114 patients, 725 (65.1%) had good adherence to antihypertensive agents. Binary logistic regression analysis was conducted. Younger age, shorter duration of antihypertensive agents used, job status being employed, and poor or very poor self-perceived health status were negatively associated with drug adherence. Conclusion This study reported a high proportion of poor medication adherence among hypertensive subjects. Patients with factors associated with poor adherence should be more closely monitored to optimize their drug taking behavior. PMID:23638143

  18. ASH position paper: Adherence and persistence with taking medication to control high blood pressure.

    PubMed

    Hill, Martha N; Miller, Nancy H; DeGeest, Sabina

    2010-10-01

    Nonadherence and poor or no persistence in taking antihypertensive medications results in uncontrolled high blood pressure, poor clinical outcomes, and preventable health care costs. Factors associated with nonadherence are multilevel and relate not only to the patient, but also to the provider, health care system, health care organization, and community. National guideline committees have called for more aggressive approaches to implement strategies known to improve adherence and technologies known to enable changes at the systems level, including improved communication among providers and patients. Improvements in adherence and persistence are likely to be achieved by supporting patient self-management, a team approach to patient care, technology-supported office practice systems, better methods to measure adherence, and less clinical inertia. Integrating high blood pressure control into health care policies that emphasize and improve prevention and management of chronic illness remains a challenge. Four strategies are proposed: focusing on clinical outcomes; empowering informed, activated patients; developing prepared proactive practice teams; and advocating for health care policy reform. With hypertension remaining the most common reason for office visits, the time is now.

  19. Association between adherence to statin therapy and lipid control in Hong Kong Chinese patients at high risk of coronary heart disease

    PubMed Central

    Cheng, Caroline W R; Woo, Kam-sang; Chan, Juliana C N; Tomlinson, Brian; You, Joyce H S

    2004-01-01

    Aims To examine the pattern of adherence to statin therapy and to determine the association of adherence to statin therapy and the control of serum low-density lipoprotein (LDL)-cholesterol in a cohort of Hong Kong Chinese patients at high risk of coronary heart disease (CHD). Methods This was a prospective observational cohort study conducted at the outpatient clinics of a public teaching hospital in Hong Kong. Patients at high risk of CHD who had been initiated on statin monotherapy for <12 months were recruited. The statin prescription was dispensed in a bottle with the Medication Event Monitoring System (MEMS). Adherence was assessed in two dimensions: dose-count was defined as the percentage of doses taken, and dose-time was defined as the percentage of doses taken within the suggested time interval. Lipid profiles were obtained at baseline and during two follow-up visits at month 3 and month 6. Results Eighty-three patients completed the study. The median adherence to dose-count and to dose-time were 95% (25-75th percentile = 87–99%) and 78% (25–75th percentile = 17–92%), respectively. Both dose-count and dose-time adherence declined slightly over the first 6 months of therapy. Living with family [relative risk (RR) = 0.79, 95% confidence interval (CI) 0.63, 0.91] and duration of therapy (RR = 0.99, 95% CI 0.98, 1.00) were negative predictors while number of family members (among those living with family) (RR = 1.05, 95% CI 1.00, 1.08) was a positive predictor for adherence to dose-count. Monthly household income (RR = 1.01, 95% CI 1.00, 1.02) and angina (RR = 1.29, 95% CI 1.05, 1.58) were positive predictors while living with family (RR = 0.74, 95% CI 0.55, 0.90) was a negative predictor for dose-time adherence. Percent reduction in serum LDL-cholesterol was correlated to dose-count (P < 0.001) and dose-time (P = 0.047) adherence. Statistically significant correlations were observed between adherence to dose-count and LDL reduction (R2 = 0.130; P = 0

  20. An Innovative High Thermal Conductivity Fuel Design

    SciTech Connect

    Jamil A. Khan

    2009-11-21

    Thermal conductivity of the fuel in today's Light Water Reactors, Uranium dioxide, can be improved by incorporating a uniformly distributed heat conducting network of a higher conductivity material, Silicon Carbide. The higher thermal conductivity of SiC along with its other prominent reactor-grade properties makes it a potential material to address some of the related issues when used in UO2 [97% TD]. This ongoing research, in collaboration with the University of Florida, aims to investigate the feasibility and develop a formal methodology of producing the resultant composite oxide fuel. Calculations of effective thermal conductivity of the new fuel as a function of %SiC for certain percentages and as a function of temperature are presented as a preliminary approach. The effective thermal conductivities are obtained at different temperatures from 600K to 1600K. The corresponding polynomial equations for the temperature-dependent thermal conductivities are given based on the simulation results. Heat transfer mechanism in this fuel is explained using a finite volume approach and validated against existing empirical models. FLUENT 6.1.22 was used for thermal conductivity calculations and to estimate reduction in centerline temperatures achievable within such a fuel rod. Later, computer codes COMBINE-PC and VENTURE-PC were deployed to estimate the fuel enrichment required, to maintain the same burnup levels, corresponding to a volume percent addition of SiC.

  1. High-level adherence to a Mediterranean diet beneficially impacts the gut microbiota and associated metabolome.

    PubMed

    De Filippis, Francesca; Pellegrini, Nicoletta; Vannini, Lucia; Jeffery, Ian B; La Storia, Antonietta; Laghi, Luca; Serrazanetti, Diana I; Di Cagno, Raffaella; Ferrocino, Ilario; Lazzi, Camilla; Turroni, Silvia; Cocolin, Luca; Brigidi, Patrizia; Neviani, Erasmo; Gobbetti, Marco; O'Toole, Paul W; Ercolini, Danilo

    2016-11-01

    Habitual diet plays a major role in shaping the composition of the gut microbiota, and also determines the repertoire of microbial metabolites that can influence the host. The typical Western diet corresponds to that of an omnivore; however, the Mediterranean diet (MD), common in the Western Mediterranean culture, is to date a nutritionally recommended dietary pattern that includes high-level consumption of cereals, fruit, vegetables and legumes. To investigate the potential benefits of the MD in this cross-sectional survey, we assessed the gut microbiota and metabolome in a cohort of Italian individuals in relation to their habitual diets. We retrieved daily dietary information and assessed gut microbiota and metabolome in 153 individuals habitually following omnivore, vegetarian or vegan diets. The majority of vegan and vegetarian subjects and 30% of omnivore subjects had a high adherence to the MD. We were able to stratify individuals according to both diet type and adherence to the MD on the basis of their dietary patterns and associated microbiota. We detected significant associations between consumption of vegetable-based diets and increased levels of faecal short-chain fatty acids, Prevotella and some fibre-degrading Firmicutes, whose role in human gut warrants further research. Conversely, we detected higher urinary trimethylamine oxide levels in individuals with lower adherence to the MD. High-level consumption of plant foodstuffs consistent with an MD is associated with beneficial microbiome-related metabolomic profiles in subjects ostensibly consuming a Western diet. This study was registered at clinical trials.gov as NCT02118857. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  2. Conducting polymer for high power ultracapacitor

    DOEpatents

    Shi, Steven Z.; Gottesfeld, Shimshon

    2002-01-01

    In accordance with the purposes of the present invention, as embodied and broadly described herein, the present invention is directed to an electrode having a conducting polymer active material for use in an ultracapacitor. The conducting polymer active material is electropolymerized onto a carbon paper substrate from a mixed solution of a dimer of (3,3' bithiophene) (BT) and a monomer that is selected from the group of thiophenes derived in the 3-position, having an aryl group attached to thiophene in the 3-position or having aryl and alkly groups independently attached to thiophene in the 3 and 4 positions.

  3. Electric conductance of highly selective nanochannels

    NASA Astrophysics Data System (ADS)

    Schnitzer, Ory; Yariv, Ehud

    2013-05-01

    We consider electric conductance through a narrow nanochannel in the thick-double-layer limit, where the space-charge Debye layers adjacent to the channel walls overlap. At moderate surface-charge densities the electrolyte solution filling the channel comprises mainly of counterions. This allows to derive an analytic closed-form approximation for the channel conductance, independent of the salt concentration in the channel reservoirs. The derived expression consists of two terms. The first, representing electromigratory transport, is independent of the channel depth. The second, representing convective transport, depends upon it weakly.

  4. Electrochemical cell with high conductivity glass electrolyte

    DOEpatents

    Nelson, P.A.; Bloom, I.D.; Roche, M.F.

    1987-04-21

    A secondary electrochemical cell with sodium-sulfur or other molten reactants is provided with a ionically conductive glass electrolyte. The cell is contained within an electrically conductive housing with a first portion at negative potential and a second portion insulated therefrom at positive electrode potential. The glass electrolyte is formed into a plurality of elongated tubes and placed lengthwise within the housing. The positive electrode material, for instance sulfur, is sealed into the glass electrolyte tubes and is provided with an elongated axial current collector. The glass electrolyte tubes are protected by shield tubes or sheets that also define narrow annuli for wicking of the molten negative electrode material. 6 figs.

  5. Electrochemical cell with high conductivity glass electrolyte

    DOEpatents

    Nelson, P.A.; Bloom, I.D.; Roche, M.F.

    1986-04-17

    A secondary electrochemical cell with sodium-sulfur or other molten reactants is provided with an ionically conductive glass electrolyte. The cell is contained within an electrically conductive housing with a first portion at negative potential and a second portion insulated therefrom at positive electrode potential. The glass electrolyte is formed into a plurality of elongated tubes and placed lengthwise within the housing. The positive electrode material, for instance sulfur, is sealed into the glass electrolyte tubes and is provided with an elongated axial current collector. The glass electrolyte tubes are protected by shield tubes or sheets that also define narrow annuli for wicking of the molten negative electrode material.

  6. Electrochemical cell with high conductivity glass electrolyte

    DOEpatents

    Nelson, Paul A.; Bloom, Ira D.; Roche, Michael F.

    1987-01-01

    A secondary electrochemical cell with sodium-sulfur or other molten reactants is provided with a ionically conductive glass electrolyte. The cell is contained within an electrically conductive housing with a first portion at negative potential and a second portion insulated therefrom at positive electrode potential. The glass electrolyte is formed into a plurality of elongated tubes and placed lengthwise within the housing. The positive electrode material, for instance sulfur, is sealed into the glass electrolyte tubes and is provided with an elongated axial current collector. The glass electrolyte tubes are protected by shield tubes or sheets that also define narrow annuli for wicking of the molten negative electrode material.

  7. Inhibition of Enterococcus faecium adherence to collagen by antibodies against high-affinity binding subdomains of Acm.

    PubMed

    Nallapareddy, Sreedhar R; Sillanpää, Jouko; Ganesh, Vannakambadi K; Höök, Magnus; Murray, Barbara E

    2007-06-01

    Strains of Enterococcus faecium express a cell wall-anchored protein, Acm, which mediates adherence to collagen. Here, we (i) identify the minimal and high-affinity binding subsegments of Acm and (ii) show that anti-Acm immunoglobulin Gs (IgGs) purified against these subsegments reduced E. faecium TX2535 strain collagen adherence up to 73 and 50%, respectively, significantly more than the total IgGs against the full-length Acm A domain (28%) (P < 0.0001). Blocking Acm adherence with functional subsegment-specific antibodies raises the possibility of their use as therapeutic or prophylactic agents.

  8. Adherence discourse among African-American women taking HAART

    PubMed Central

    Sankar, A.; Luborsky, M.; Schuman, P.; Roberts, G.

    2014-01-01

    Low adherence is the single most important challenge to controlling HIV through the use of high acting anti-retrovirals (HAART). Non-adherence poses an immediate threat to individuals who develop resistant forms of the virus as well as a public health threat if those individuals pass on treatment-resistant forms of the virus. To understand the concerns and perceptions that promote or deter adherence to antiretroviral medication by HIV-positive African-American women, we conducted in-depth interviews with 15 African-American women taking HAART. We focused on the discourse and narratives women use in talking about their adherence practice. Discourse analysis was utilized to identify and explore the sources of influence used by these women in describing their adherence practice. Roughly a third of the sample fell into each of the three self-assessed adherence categories: always adherent, mostly adherent and somewhat adherent. Among the ‘always adherent’, 80% of the sources of influence cited supported adherence, while only 48% and 47% of the authoritative sources cited by women in the ‘mostly’ and ‘somewhat’ categories supported adherence. Each self-assessed adherence group was characterized by its own distinctive discourse style. Findings suggest that adherence to HAART among African-American HIV-positive women would be improved by identifying those influences undermining adherence. Focused study of the ‘always adherent’ types is recommended. PMID:11940279

  9. High precision cryogenic thermal conductivity standards

    NASA Technical Reports Server (NTRS)

    Hust, J. G.; Powell, R. L.; Weitzel, D. H.

    1970-01-01

    New apparatus allows accurate simultaneous measurement of thermal conductivity, electrical resistivity, and thermopower for technically important materials, such as new or uncommon alloys. A list of materials investigated is presented. Sources for obtaining data on these materials, as well as the source giving a description of the apparatus, are cited.

  10. Adherence to highly active antiretroviral therapy in depressed patients with HIV/AIDS attending a Nigerian university teaching hospital clinic.

    PubMed

    Olisah, V O; Baiyewu, O; Sheikh, T L

    2010-09-01

    To determine the prevalence of depressive disorder in patients with HIV/AIDS receiving HAART; to determine the effect of depressive disorder on adherence to antiretroviral therapy; and to determine the significance of the association. The study was conducted amongst outpatients of Ahmadu Bello University Teaching Hospital, Zaria. A sociodemographic and drug adherence questionnaire was administered. The Centre for Epidemiological Studies Depression Scale (CES-D) was used to screen for depressive symptoms while the Schedule for Clinical Assessment in Neuropsychiatry (SCAN) was used to confirm the diagnosis of depressive disorder. A total of 310 patients with HIV/AIDS receiving HAART participated in the study. 68.4% were female and the mean age was 35.5 (± 8.97 years). 37.4% had secondary education, while 27.1% had tertiary education. Sixty-six participants (21.3%) had significant depressive symptoms while 14.2% met ICD-10 diagnostic criteria for depressive disorder. Overall, 73% of participants had good adherence to HAART. 63.6% of participants with depressive disorder had poor adherence to HAART compared to 21.1% of participants without depressive disorder (p<0.05). Depressive disorder in patients with HIV/AIDS is associated with poor adherence to antiretroviral medication. Early identification and treatment of depression in such patients may improve antiretroviral medication adherence and treatment outcomes.

  11. Bioluminescent high-throughput assay for the bacteria adherence to the tissue culture cells.

    PubMed

    Brovko, L; Minikh, O; Piekna, A; Griffiths, M W

    2011-07-01

    The goal of this study was develop a rapid high-throughput method for the assessment of the bacterial adhesion to tissue culture cells and test this method by investigation of the adhesion and growth of pathogenic and non-pathogenic Escherichia coli strains in the presence of HeLa human epithelial cells. Fifteen strains of E. coli were transformed with a plasmid carrying the entire lux operon of Photorhabdus luminescens to make them bioluminescent. By using the Time-to-Detection approach and bioluminescence imaging in microplate format, the adherence and growth of bacteria in tissue culture medium in the presence of HeLa cells was monitored. It was observed that Eagle's minimal essential medium (EMEM) supplemented with 10% fetal bovine serum (FBS) significantly inhibited growth of E. coli. However, in the presence of HeLa cells the detected growth of E. coli was similar to the growth observed in LB medium. It was established that the initial number of E. coli cells present in the microplate directly correlated with the time necessary for the bioluminescence signal to reach the threshold level, hence allowing the accurate assessment of the adhered cells within 8-10 h. Neither bacterial adherence nor growth kinetics correlated with the pathogenicity of the strain though they were strain-specific. The developed approach provided new information on the interaction of E. coli with epithelial cells and could be used for both pathogenicity research and for the screening of potential therapeutic agents for the ability to minimize pathogen colonization of human tissues.

  12. Seasonal changes in the adherent microflora of the rumen in high-arctic Svalbard reindeer.

    PubMed

    Cheng, K J; McAllister, T A; Mathiesen, S D; Blix, A S; Orpin, C G; Costerton, J W

    1993-01-01

    Seasonal changes in bacterial colonization of the epithelial tissue were examined in the rumen of high-arctic Svalbard reindeer. Samples of tissue were collected from eight sites in the rumen of reindeer during summer and winter and bacterial colonization was examined using scanning and transmission electron microscopy. At two of these sites, colonization by adherent bacteria was estimated to cover approximately 30% of the ruminal epithelium in specimens collected from reindeer during summer. Bacteria at these sites resembled Ruminococcus sp. and were surrounded by large amounts of glycocalyx. In winter specimens, less than 10% of the epithelial surface was covered by adherent bacteria. Those bacteria that did colonize the epithelial surface were smaller and had virtually no glycocalyx on their surface. Bacteria attached to plant cell wall material in summer samples of reindeer ingesta contained large intracellular glycogen deposits, whereas feed particle-associated bacteria in ingesta collected in winter contained no intracellular glycogen. These data demonstrate that the ruminal bacterial population responds to seasonal changes in feed intake and quality. It is yet to be determined if these bacterial changes enhance the ability of Svalbard reindeer to survive in the hostile environment of the high Arctic.

  13. Towards high-throughput automated targeted femtosecond laser-based transfection of adherent cells

    NASA Astrophysics Data System (ADS)

    Antkowiak, Maciej; Torres-Mapa, Maria Leilani; Gunn-Moore, Frank; Dholakia, Kishan

    2011-03-01

    Femtosecond laser induced cell membrane poration has proven to be an attractive alternative to the classical methods of drug and gene delivery. It is a selective, sterile, non-contact technique that offers a highly localized operation, low toxicity and consistent performance. However, its broader application still requires the development of robust, high-throughput and user-friendly systems. We present a system capable of unassisted enhanced targeted optoinjection and phototransfection of adherent mammalian cells with a femtosecond laser. We demonstrate the advantages of a dynamic diffractive optical element, namely a spatial light modulator (SLM) for precise three dimensional positioning of the beam. It enables the implementation of a "point-and-shoot" system in which using the software interface a user simply points at the cell and a predefined sequence of precisely positioned doses can be applied. We show that irradiation in three axial positions alleviates the problem of exact beam positioning on the cell membrane and doubles the number of viably optoinjected cells when compared with a single dose. The presented system enables untargeted raster scan irradiation which provides transfection of adherent cells at the throughput of 1 cell per second.

  14. High-molecular-mass lipopolysaccharides are involved in Actinobacillus pleuropneumoniae adherence to porcine respiratory tract cells.

    PubMed Central

    Paradis, S E; Dubreuil, D; Rioux, S; Gottschalk, M; Jacques, M

    1994-01-01

    Actinobacillus pleuropneumoniae is the causative agent of porcine pleuropneumonia. The major adhesin of A. pleuropneumoniae has been identified as the lipopolysaccharides (LPSs) (M. Bélanger, D. Dubreuil, J. Harel, C. Girard, and M. Jacques, Infect. Immun. 58:3523-3530, 1990). Using immunoelectron microscopy and flow cytometry, we showed in the present study that LPSs were well exposed at the surface of this encapsulated microorganism. Immunolocalization with porcine lung and tracheal frozen sections showed that extracted LPS bound to the lung mesenchyme and vascular endothelium and to the tracheal epithelium, respectively. Inhibition of adherence of A. pleuropneumoniae with extracted LPS was also performed with lung and tracheal frozen sections. Acid hydrolysis of LPS revealed that the active component of LPS was not lipid A but the polysaccharides. LPSs from A. pleuropneumoniae serotypes 1 and 2 were separated by chromatography on Sephacryl S-300 SF, in the presence of sodium deoxycholate, according to their molecular masses. The adherence-inhibitory activity was found in the high-molecular-mass fractions. These high-molecular-mass fractions contained 2-keto-3-deoxyoctulosonic acid and neutral sugars, and they were recognized by a monoclonal antibody directed against A. pleuropneumoniae O antigen but not recognized by a monoclonal antibody against capsular antigen. Images PMID:8039902

  15. Patterns of adherence behaviour for patients with glaucoma.

    PubMed

    Cate, H; Bhattacharya, D; Clark, A; Holland, R; Broadway, D C

    2013-04-01

    Adherence to long-term treatment regimens for primary open-angle glaucoma holds a challenge for both clinicians and patients. The study aims were to (i) establish the magnitude of travoprost non-adherence using an Electronic Adherence Monitor (EAM), (ii) compare electronic with patient self-reported adherence, and (iii) explore the application of a previously reported method of graphically presenting adherence data to a larger cohort over a longer monitoring period. A cohort study of patients using travoprost for glaucoma or ocular hypertension was conducted. All participants used an EAM and adherence data were collected prospectively for 2 months. Self-reported adherence was obtained using the Morisky Medication Adherence Scale (MMAS); patients also reported frequency of missed doses. Potential predictors of adherence were collected via a structured interview. EAM-recorded interdose intervals were plotted graphically. Of 100 patients invited to participate, 98 consented and EAM data were collected successfully from 88 participants. The median EAM adherence score for the cohort was 88.9% (interquartile range: 71.2, 92.2). When dichotomised (≥80%: adherent; <80%: non-adherent), EAM identified 36.7% as non-adherent and MMAS 12.2%. EAM data were used to classify five types of adherence behaviour including a category representing levels of ≥97% maintained by 21% of participants. EAM revealed good adherence to glaucoma monotherapy but poor agreement with patient self-reported adherence. An adherence category of persistent and exceptionally high adherence to travoprost over a 2-month period was identified.

  16. Adherence to Latent Tuberculosis Infection Treatment in a Population with a High Number of Refugee Children.

    PubMed

    Rogo, Tanya; Eleanya, Cynthia; Hirway, Priya; Pelland, Doreen; Lewis, Carol; Dennehy, Penelope; Losikoff, Phyllis

    2017-02-01

    Refugee populations in the US have a higher reported prevalence of latent tuberculosis infection (LTBI). The objective of this study was to assess adherence to LTBI treatment in refugee and non-refugee children living in Rhode Island. This was a retrospective review of LTBI patients seen in the Hasbro Pediatric Tuberculosis Clinic between August 2009 and September 2011. Of 120 patients with LTBI, 93% were foreign-born and 30% were refugees. Overall, 94 children (78.3%) completed therapy. Higher rates of treatment completion were seen among patients who were female, referred within the same hospital system, used an interpreter, and did not report side effects. Refugees attended more scheduled visits compared to non-refugees (p=0.019). Overall rates of completion of LTBI treatment were high in this population. Better adherence to clinic visits, likely due to the increased support and care coordination provided to the refugee children, improved treatment completion rates. [Full article available at http://rimed.org/rimedicaljournal-2017-02.asp].

  17. Effects of high dietary fluorine on erythrocytes and erythrocyte immune adherence function in broiler chickens.

    PubMed

    Deng, Yubing; Cui, Hengmin; Peng, Xi; Fang, Jing; Zuo, Zhicai; Deng, Junliang; Luo, Qin

    2013-11-01

    Fluoride can exert toxic effects on soft tissues, giving rise to a broad array of symptoms and pathological changes. The aim of this study was to investigate on erythrocytes and erythrocyte immune adherence function in broiler chickens fed with high fluorine (F) diets by measuring the total erythrocyte count (TEC), the contents of hemoglobin (Hb), packed cell volumn (PCV), erythrocyte osmotic fragility (EOF), erythrocyte C3b receptor rosette rate (E-C3bRR), and erythrocyte immune complex rosette rate (E-ICRR). A total of 280 1-day-old healthy avian broiler chickens were randomly allotted into four equal groups of 70 birds each and fed with a corn-soybean basal diet containing 22.6 mg F/kg (control group) or same basal diets supplemented with 400, 800, and 1,200 mg F/kg (high F groups I, II, and III) in the form of sodium fluoride for 42 days. Blood samples were collected for the abovementioned parameters analysis at 14, 28, and 42 days of age during the experiment. The experimental results indicated that TEC, Hb, and PCV were significantly lower (p < 0.05 or p < 0.01), and EOF was higher (p < 0.05 or p < 0.01) in the high F groups II and III than that in the control group from 14 to 42 days of age. The E-C3bRR was significantly decreased (p < 0.01) in the three high F groups, whereas the E-ICRR was markedly increased (p < 0.01) in the high F groups II and III from 14 to 42 days of age. It was concluded that dietary F in the range of 800 to 1, 200 mg/kg could significantly cause anemia and impair the integrity of erythrocyte membrane, the transport capacity of oxygen and carbon dioxide, and erythrocyte immune adherence function in broiler chickens.

  18. Unconventional High Density Vertically Aligned Conducting Polymer

    DTIC Science & Technology

    2014-08-21

    CVD) method on silicon substrates using iron (Fe) on alumina as a catalyst . The as-grown A-CNT forests have a 1% volume fraction (Vf) of CNTs with...here, consisting of the anode of the conformal coating of oCVD PEDOT on A-CNTs (PEDOT/A-CNTs) and ultra-high density graphene-oxide cathode ( HD -a

  19. Long and high conductance helium heat pipe

    NASA Astrophysics Data System (ADS)

    Gully, Philippe

    2014-11-01

    This paper reports on the development and the thermal tests of two superfluid helium heat pipes. They feature a copper braid located inside a 6 mm outer diameter stainless tube fitted with copper ends for mechanical anchoring. The copper braid is the support of the Rollin superfluid helium film which is essential in the heat transfer. The extremely low thickness of the liquid film allows for a low filling pressure, making the technology very simple without the need for any external hot reservoir and with the possibility to easily bend the tube. We present the design and discuss the thermal performance of two heat pipes tested for several filling pressures, adverse tilt angles and in 1.4-2.0 K temperature range. A minimum filling pressure (0.6 MPa) is needed to get significant transport capacity. A 12 mW transport capacity is achieved for 3.0 MPa filling pressure. It is shown that the long heat pipe (1.2 m) and the short one (0.25 m) have similar thermal performance in adverse tilt. At 1.7 K the long heat pipe, 120 g in weight, reaches a transport capacity of 5.7 mW/4.2 mW for a tilt angle of 0 / 60° and a thermal conductance of 600 mW/K for 4 mW transferred power. When the condenser reaches the super-fluid transition temperature, the Rollin film accelerates the cool down of the evaporator down to 1.7 K with a heating power applied to the evaporator.

  20. ELECTRONIC MONITORING REVEALS HIGHLY VARIABLE ADHERENCE PATTERNS IN PATIENTS PRESCRIBED IVACAFTOR

    PubMed Central

    Siracusa, Christopher M.; Ryan, Jamie; Burns, Lisa; Wang, Yu; Zhang, Nanhua; Clancy, John P.; Drotar, Dennis

    2015-01-01

    Background Previous studies of CF treatments have shown suboptimal adherence, though little has been reported regarding adherence patterns to ivacaftor. Electronic monitoring (EM) of adherence is considered a gold standard of measurement. Methods Adherence rates by EM were prospectively obtained and patterns over time were analyzed. EM-derived adherence rates were compared to pharmacy refill history and self-report. Results 12 subjects (age 6-48 years; CFTR-G551D mutation) previously prescribed ivacaftor were monitored for a mean of 118 days. Overall adherence by EM was 61%(SD=28%) and decreased over time. Median duration between doses was 16.9 hours (IQR 13.9-24.1 hours) and increased over time. There was no correlation between EM-derived adherence and either refill history (84%, r=0.26, p=0.42) or self-report (100%, r=0.40, p=0.22). Conclusions Despite the promising nature of ivacaftor, our data suggest adherence rates are suboptimal and comparable to other prescribed CF therapies, and more commonly used assessments of adherence may be unreliable. PMID:26074007

  1. An educational intervention to improve adherence to high-dosage patching regimen for amblyopia: a randomised controlled trial.

    PubMed

    Pradeep, Archana; Proudlock, Frank Antony; Awan, Musarat; Bush, Glen; Collier, Jacqueline; Gottlob, Irene

    2014-07-01

    Previous reports suggest that adherence to patching is a major issue in amblyopia treatment. We tested with an unmasked randomised controlled clinical trial whether an intense educational/motivational intervention improves adherence when a high-dose regime is prescribed. 62 children with newly diagnosed amblyopia were randomly allocated into two treatment arms with and without educational/motivational intervention material. Both were prescribed patching 10 h/day, 6 days/week for a fixed period of 12 weeks. The intervention arm received an educational/motivational intervention before patching which included information booklets, video, a cartoon story book, sticker charts and a dedicated session with a researcher. The control arm received the usual clinical information. The primary outcome measure was adherence measured using electronic occlusion dose monitors where a success/failure binary outcome was used to account for participants who dropped out of the study defined as patching >4 h/day. Visual outcome, expressed as percentage visual deficit, was measured as secondary outcome. The intervention increased adherence success rate from 45.2% in the control group to 80.6% in the intervention group (p=0.0027). However, visual outcome was not significantly better in the intervention group (p=0.190). Our study shows that an intense educational/motivational intervention can improve adherence to patching to high prescribed doses although no significant improvement in visual outcome was observed. TRIALS REGISTRATION NUMBER: ISRCTN05346737 (International Standard Randomised Controlled Trial Number Register).

  2. CBT for insomnia in patients with high and low depressive symptom severity: adherence and clinical outcomes.

    PubMed

    Manber, Rachel; Bernert, Rebecca A; Suh, Sooyeon; Nowakowski, Sara; Siebern, Allison T; Ong, Jason C

    2011-12-15

    To evaluate whether depressive symptom severity leads to poorer response and perceived adherence to cognitive behavioral therapy for insomnia (CBTI) and to examine the impact of CBTI on well-being, depressive symptom severity, and suicidal ideation. Pre- to posttreatment case replication series comparing low depression (LowDep) and high depression (HiDep) groups (based on a cutoff of 14 on the Beck Depression Inventory [BDI]). 127 men and 174 women referred for the treatment of insomnia. Seven sessions of group CBTI. Improvement in the insomnia severity, perceived energy, productivity, self-esteem, other aspects of wellbeing, and overall treatment satisfaction did not differ between the HiDep and LowDep groups (p > 0.14). HiDep patients reported lower adherence to a fixed rise time, restricting time in bed, and changing expectations about sleep (p < 0.05). HiDep participants experienced significant reductions in BDI, after removing the sleep item. Levels of suicidal ideation dropped significantly among patients with pretreatment elevations (p < 0.0001). Results suggest that pre- to post CBTI improvements in insomnia symptoms, perceived energy, productivity, self-esteem, and other aspects of well-being were similar among patients with and without elevation in depressive symptom severity. Thus, the benefits of CBTI extend beyond insomnia and include improvements in non-sleep outcomes, such as overall well-being and depressive symptom severity, including suicidal ideation, among patients with baseline elevations. Results identify aspects of CBTI that may merit additional attention to further improve outcomes among patients with insomnia and elevated depressive symptom severity.

  3. Comparisons of Adherence to Antiretroviral Therapy in a High- Risk Population in China: A Systematic Review and Meta-Analysis

    PubMed Central

    Huan, Zhou; Fuzhi, Wang; Lu, Liu; Min, Zhang; Xingzhi, Chen; Shiyang, Jin

    2016-01-01

    Background Reports on antiretroviral therapy (ART) adherence are scare in China; we performed this meta-analysis to estimate ART adherence rates in different populations at high risk for HIV transmission in China. Methods We searched PubMed, Chinese Biomedical Literature Database (Chinese), China National Knowledge Infrastructure (Chinese), and Wanfang (Chinese) to identify studies published from January 1985 to May 2015. We used random-effects meta-analysis to calculate weighted mean estimates across studies and 95% CIs. Data were pooled with proportions transformed prior to pooling using the Freeman–Tukey double arcsine transformation and then back transformed to the original scale. We calculated the I2 (and its 95% confidence intervals) and tau2 to assess between-study heterogeneity. Results We identified 36 eligible articles, including 6885 HIV-positive individuals, reporting ART adherence. Pooled analysis produced an estimate of 77.61% (95% CI = 71.63–83.08) of patients with HIV with adequate adherence; however, high heterogeneity was observed between studies (I2 = 96.60%, 95%CI = 96.00%-97.20%; tau2 = 0.16). Three studies, which included 149 old HIV-infected patients, reported the highest ART adequate adherence rate (89.39%, 95% CI = 72.01–99.26) with high heterogeneity between the studies (I2 = 86.20%, 95%CI = 60.00–95.20%; tau2 = 0.13). While, only two studies, which included 143 heterosexual transmission group (HTG) patients, reported the lowest ART adequate adherence rate (51.55%, 95% CI = 41.33–61.71) with low heterogeneity between the studies (I2 = 31.3%, tau2 = 0.007). In the multivariable meta-regression model, high-risk populations was the main factor explaining heterogeneity (variance explained 28.14%). Conclusions ART adherence in some high-risk populations (e.g., heterosexual transmission group) is below the recommended levels for maintaining virologic suppression. It is crucial to develop comprehensive intervention strategies to promote

  4. Pulsed laser deposition of adherent hexagonal/cubic boron nitride layer systems at high growth rates

    NASA Astrophysics Data System (ADS)

    Weißmantel, Steffen; Reiße, Günter

    2002-09-01

    Cubic boron nitride (c-BN) films were prepared by ion-beam-assisted pulsed laser deposition (IAPLD) using a KrF excimer laser for ablation. The c-BN growth rates of 50 nm/min at relatively low substrate temperatures of 250 °C were achieved by using high laser energy densities of more than 30 J/cm 2 and at ion beam energies of 600-700 eV. Main advantage of IAPLD for the deposition of c-BN films is that at high laser energy densities the ratio of ions from the ion beam to ablated atoms and ions necessary for cubic film growth can be reduced to 0.14, since the ablated boron and nitrogen species themselves have high mean kinetic energies of 130-180 eV. By using pulsed laser deposited h-BN intermediate layers, 300-420 nm thick well-adherent c-BN films can be prepared on Si and WC hard metal substrates. The maximum c-BN film thickness of some 0.5 μm is limited by the accumulation of particulates, formed during the ablation process, in the films. The microstructure, stress, hardness and adhesion of such layer systems deposited at high growth rates are presented.

  5. Mobile Phone Text Messages to Support Treatment Adherence in Adults With High Blood Pressure (SMS-Text Adherence Support [StAR]): A Single-Blind, Randomized Trial.

    PubMed

    Bobrow, Kirsten; Farmer, Andrew J; Springer, David; Shanyinde, Milensu; Yu, Ly-Mee; Brennan, Thomas; Rayner, Brian; Namane, Mosedi; Steyn, Krisela; Tarassenko, Lionel; Levitt, Naomi

    2016-02-09

    We assessed the effect of automated treatment adherence support delivered via mobile phone short message system (SMS) text messages on blood pressure. In this pragmatic, single-blind, 3-arm, randomized trial (SMS-Text Adherence Support [StAR]) undertaken in South Africa, patients treated for high blood pressure were randomly allocated in a 1:1:1 ratio to information only, interactive SMS text messaging, or usual care. The primary outcome was change in systolic blood pressure at 12 months from baseline measured with a validated oscillometric device. All trial staff were masked to treatment allocation. Analyses were intention to treat. Between June 26, 2012, and November 23, 2012, 1372 participants were randomized to receive information-only SMS text messages (n=457), interactive SMS text messages (n=458), or usual care (n=457). Primary outcome data were available for 1256 participants (92%). At 12 months, the mean adjusted change in systolic blood pressure compared with usual care was -2.2 mm Hg (95% confidence interval, -4.4 to -0.04) with information-only SMS and -1.6 mm Hg (95% confidence interval, -3.7 to 0.6) with interactive SMS. Odds ratios for the proportion of participants with a blood pressure <140/90 mm Hg were 1.42 (95% confidence interval, 1.03-1.95) for information-only messaging and 1.41 (95% confidence interval, 1.02-1.95) for interactive messaging compared with usual care. In this randomized trial of an automated adherence support program delivered by SMS text message in a general outpatient population of adults with high blood pressure, we found a small reduction in systolic blood pressure control compared with usual care at 12 months. There was no evidence that an interactive intervention increased this effect. URL: http://www.clinicaltrials.gov. Unique identifier: NCT02019823. South African National Clinical Trials Register, number SANCTR DOH-27-1212-386; Pan Africa Trial Register, number PACTR201411000724141. © 2016 American Heart Association

  6. Characteristics, drug combinations and dosages of primary care patients with uncontrolled ambulatory blood pressure and high medication adherence.

    PubMed

    Grigoryan, Larissa; Pavlik, Valory N; Hyman, David J

    2013-01-01

    Most studies on the prevalence and determinants of resistant hypertension (RH) do not account for white coat hypertension, medication non-adherence, or use of suboptimal treatment dosages. We studied the characteristics, drug combinations, and dosages of patients on at least three antihypertensives of different classes who had uncontrolled blood pressure on 24-hour ambulatory blood pressure monitoring and high medication adherence measured by electronic monitoring. The data were collected as part of the baseline measures of a hypertension control trial. Of 140 monitored primary care patients, all with uncontrolled office blood pressure, 69 (49%) were on at least three antihypertensives of different classes. Of these 69, 15 (22%) were controlled on ambulatory blood pressure monitoring, 20 (29%) were uncontrolled and non-adherent, leaving only 34 (49%) adherent to their medications and having uncontrolled ambulatory hypertension (uncontrolled RH). Thirty-one (91%) of the 34 uncontrolled RH patients were prescribed a diuretic, of which 24 were on hydrochlorothiazide 25 mg. Less than half of the patients on angiotensin-converting enzyme inhibitor, angiotensin receptor blocker, or calcium channel blocker were prescribed maximal doses of these agents. Half of the RH can be attributed to white coat effect and poor medication adherence, and all of the remaining patients were on apparently suboptimal drug combinations and/or dosages. Primary care physicians need to be educated regarding the optimal treatment of RH. Copyright © 2013 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

  7. Low-Dimensional Conduction Mechanisms in Highly Conductive and Transparent Conjugated Polymers.

    PubMed

    Ugur, Asli; Katmis, Ferhat; Li, Mingda; Wu, Lijun; Zhu, Yimei; Varanasi, Kripa K; Gleason, Karen K

    2015-08-19

    Electronic conduction in conjugated polymers is of emerging technological interest for high-performance optoelectronic and thermoelectric devices. A completely new aspect and understanding of the conduction mechanism on conducting polymers is introduced, allowing the applicability of materials to be optimized. The charge-transport mechanism is explained by direct experimental evidence with a very well supported theoretical model. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. High-intensity cannabis use and adherence to antiretroviral therapy among people who use illicit drugs in a Canadian setting.

    PubMed

    Slawson, Gregory; Milloy, M-J; Balneaves, Lynda; Simo, Annick; Guillemi, Silvia; Hogg, Robert; Montaner, Julio; Wood, Evan; Kerr, Thomas

    2015-01-01

    Cannabis is increasingly prescribed clinically and utilized by people living with HIV/AIDS (PLWHA) to address symptoms of HIV disease and to manage side effects of antiretroviral therapy (ART). In light of concerns about the possibly deleterious effect of psychoactive drug use on adherence to ART, we sought to determine the relationship between high-intensity cannabis use and adherence to ART among a community-recruited cohort of HIV-positive illicit drug users. We used data from the ACCESS study, an ongoing prospective cohort study of HIV-seropositive illicit drug users linked to comprehensive ART dispensation records in a setting of universal no-cost HIV care. We estimated the relationship between at least daily cannabis use in the last 6 months, measured longitudinally, and the likelihood of optimal adherence to ART during the same period, using a multivariate linear mixed-effects model accounting for relevant socio-demographic, behavioral, clinical and structural factors. From May 2005 to May 2012, 523 HIV-positive illicit drug users were recruited and contributed 2,430 interviews. At baseline, 121 (23.1 %) participants reported at least daily cannabis use. In bivariate and multivariate analyses we did not observe an association between using cannabis at least daily and optimal adherence to prescribed HAART (Adjusted Odds Ratio = 1.12, 95 % Confidence Interval [95 % CI]: 0.76-1.64, p value = 0.555.) High-intensity cannabis use was not associated with adherence to ART. These findings suggest cannabis may be utilized by PLWHA for medicinal and recreational purposes without compromising effective adherence to ART.

  9. Rearrangement of 1D conducting nanomaterials towards highly electrically conducting nanocomposite fibres for electronic textiles.

    PubMed

    Han, Joong Tark; Choi, Sua; Jang, Jeong In; Seol, Seung Kwon; Woo, Jong Seok; Jeong, Hee Jin; Jeong, Seung Yol; Baeg, Kang-Jun; Lee, Geon-Woong

    2015-03-20

    Nanocarbon-based conducting fibres have been produced using solution- or dry-spinning techniques. Highly conductive polymer-composite fibres containing large amounts of conducting nanomaterials have not been produced without dispersants, however, because of the severe aggregation of conducting materials in high-concentration colloidal solutions. Here we show that highly conductive (electrical conductivity ~1.5 × 10(5) S m(-1)) polymer-composite fibres containing carbon nanotubes and silver nanowires can be fabricated via a conventional solution-spinning process without any other treatment. Spinning dopes were fabricated by a simple mixing of a polyvinyl alcohol solution in dimethylsulfoxide with a paste of long multi-walled carbon nanotubes dispersed in organic solvents, assisted by quadruple hydrogen-bonding networks and an aqueous silver nanowire dispersion. The high electrical conductivity of the fibre was achieved by rearrangement of silver nanowires towards the fibre skin during coagulation because of the selective favourable interaction between the silver nanowires and coagulation solvents. The prepared conducting fibres provide applications in electronic textiles such as a textile interconnector of light emitting diodes, flexible textile heaters, and touch gloves for capacitive touch sensors.

  10. Rearrangement of 1D Conducting Nanomaterials towards Highly Electrically Conducting Nanocomposite Fibres for Electronic Textiles

    PubMed Central

    Han, Joong Tark; Choi, Sua; Jang, Jeong In; Seol, Seung Kwon; Woo, Jong Seok; Jeong, Hee Jin; Jeong, Seung Yol; Baeg, Kang-Jun; Lee, Geon-Woong

    2015-01-01

    Nanocarbon-based conducting fibres have been produced using solution- or dry-spinning techniques. Highly conductive polymer-composite fibres containing large amounts of conducting nanomaterials have not been produced without dispersants, however, because of the severe aggregation of conducting materials in high-concentration colloidal solutions. Here we show that highly conductive (electrical conductivity ~1.5 × 105 S m−1) polymer-composite fibres containing carbon nanotubes and silver nanowires can be fabricated via a conventional solution-spinning process without any other treatment. Spinning dopes were fabricated by a simple mixing of a polyvinyl alcohol solution in dimethylsulfoxide with a paste of long multi-walled carbon nanotubes dispersed in organic solvents, assisted by quadruple hydrogen-bonding networks and an aqueous silver nanowire dispersion. The high electrical conductivity of the fibre was achieved by rearrangement of silver nanowires towards the fibre skin during coagulation because of the selective favourable interaction between the silver nanowires and coagulation solvents. The prepared conducting fibres provide applications in electronic textiles such as a textile interconnector of light emitting diodes, flexible textile heaters, and touch gloves for capacitive touch sensors. PMID:25792333

  11. Rearrangement of 1D Conducting Nanomaterials towards Highly Electrically Conducting Nanocomposite Fibres for Electronic Textiles

    NASA Astrophysics Data System (ADS)

    Han, Joong Tark; Choi, Sua; Jang, Jeong In; Seol, Seung Kwon; Woo, Jong Seok; Jeong, Hee Jin; Jeong, Seung Yol; Baeg, Kang-Jun; Lee, Geon-Woong

    2015-03-01

    Nanocarbon-based conducting fibres have been produced using solution- or dry-spinning techniques. Highly conductive polymer-composite fibres containing large amounts of conducting nanomaterials have not been produced without dispersants, however, because of the severe aggregation of conducting materials in high-concentration colloidal solutions. Here we show that highly conductive (electrical conductivity ~1.5 × 105 S m-1) polymer-composite fibres containing carbon nanotubes and silver nanowires can be fabricated via a conventional solution-spinning process without any other treatment. Spinning dopes were fabricated by a simple mixing of a polyvinyl alcohol solution in dimethylsulfoxide with a paste of long multi-walled carbon nanotubes dispersed in organic solvents, assisted by quadruple hydrogen-bonding networks and an aqueous silver nanowire dispersion. The high electrical conductivity of the fibre was achieved by rearrangement of silver nanowires towards the fibre skin during coagulation because of the selective favourable interaction between the silver nanowires and coagulation solvents. The prepared conducting fibres provide applications in electronic textiles such as a textile interconnector of light emitting diodes, flexible textile heaters, and touch gloves for capacitive touch sensors.

  12. Adherence in ulcerative colitis: an overview

    PubMed Central

    Testa, Anna; Castiglione, Fabiana; Nardone, Olga Maria; Colombo, Giorgio L

    2017-01-01

    Medication adherence is an important challenge while treating chronic illnesses, such as ulcerative colitis (UC), that require a long-term management to induce and maintain clinical remission. This review provides an overview of the role that medication adherence plays in the routine management of UC, with a focus on the results of a recent Italian study reporting the perception of patients with UC regarding adherence to treatment. A literature analysis was conducted on topics, such as measurement of adherence in real practice, causes, risk factors and consequences of non-adherence and strategies, to raise patients’ adherence. Most of the data refer to adherence to 5-aminosalicylic acid, and standard of care for the induction and maintenance of remission in UC. The adherence rate to 5-aminosalicylic acid is low in clinical practice, thus resulting in fivefold higher risk of relapse, likely increased risk of colorectal cancer, reduced quality of life and higher health care costs for in- and outpatient settings. There are various causes affecting non-adherence to therapy: forgetfulness, high cost of drugs, lack of understanding of the drug regimen – which are sometimes due to insufficient explanation by the specialist – anxiety created by possible adverse events, lack of confidence in physicians’ judgment and complex dosing regimen. The last aspect negatively influences adherence to medication both in clinical trial settings and in real-world practice. Regarding this feature, mesalamine in once-daily dosage may be preferable to medications with multiple doses per day because the simplification of treatment regimens improves adherence. PMID:28260866

  13. Medication adherence in schizophrenia.

    PubMed

    Acosta, Francisco Javier; Hernández, José Luis; Pereira, José; Herrera, Judit; Rodríguez, Carlos J

    2012-10-22

    Non-adherence is a major problem in the treatment of schizophrenia. Its high prevalence, potentially severe consequences and associated costs make the study of this phenomenon a priority issue. In this article, basic non-adherence concepts of prevalence, consequences, evaluation methods, methodological restrictions of available studies, risk factors and intervention strategies, are reviewed. Studying non-adherence risk factors is a necessary step toward designing adequately oriented intervention strategies. An operative definition of adherence and good knowledge of its evaluation methods are essential to study this phenomenon. Unfortunately, most available studies contain methodological restrictions, especially concerning the evaluation methods, and an agreed operative definition of adherence has only very recently been reached. Knowing non-adherence risk factors, intervention strategies and available evidence on their effectiveness is essential in making treatment decisions in daily clinical practice.

  14. Medication adherence in schizophrenia

    PubMed Central

    Acosta, Francisco Javier; Hernández, José Luis; Pereira, José; Herrera, Judit; Rodríguez, Carlos J

    2012-01-01

    Non-adherence is a major problem in the treatment of schizophrenia. Its high prevalence, potentially severe consequences and associated costs make the study of this phenomenon a priority issue. In this article, basic non-adherence concepts of prevalence, consequences, evaluation methods, methodological restrictions of available studies, risk factors and intervention strategies, are reviewed. Studying non-adherence risk factors is a necessary step toward designing adequately oriented intervention strategies. An operative definition of adherence and good knowledge of its evaluation methods are essential to study this phenomenon. Unfortunately, most available studies contain methodological restrictions, especially concerning the evaluation methods, and an agreed operative definition of adherence has only very recently been reached. Knowing non-adherence risk factors, intervention strategies and available evidence on their effectiveness is essential in making treatment decisions in daily clinical practice. PMID:24175171

  15. Oral Adherence Monitoring Using a Breath Test to Supplement Highly Active Antiretroviral Therapy

    PubMed Central

    Morey, Timothy E.; Booth, Matthew; Wasdo, Scott; Wishin, Judith; Quinn, Brian; Gonzalez, Daniel; Derendorf, Hartmut; McGorray, Susan P.; Simoni, Jane; Melker, Richard J.; Dennis, Donn M.

    2012-01-01

    A breath-based adherence system to document ingestion of oral medications (e.g., HAART) was investigated. Specifically, the food additive 2-butanol, which can be easily packaged with a drug, is converted via alcohol dehydrogenase to the volatile metabolite 2-butanone that rapidly appears in breath, indicating adherence. In healthy adults using a portable sensor and GC-MS, the following experiments were performed: yield of 2-butanone in breath following ingestion of 2-butanol, adherence system accuracy, and potential interference of the adherence system by food or misplacement of 2-butanol on the tongue. During feasibility testing, every subject exhaled 2-butanone with 6.6±1.5 min to peak concentrations of 548±235 ppb following ingestion of 2-butanol (40 mg). ROC areas at 5 and 10 min were 0.95 (0.86–1.00) and 3 1.00 (1.00–1.00). Food did not interfere. Tongue application resulted in large concentrations of 2-butanol, but not 2-butanone. A breath test to provide definitive evidence of oral medication adherence appears technically feasible. PMID:23001413

  16. High thermal conductivity lossy dielectric using a multi layer configuration

    DOEpatents

    Tiegs, Terry N.; Kiggans, Jr., James O.

    2003-01-01

    Systems and methods are described for loss dielectrics. A loss dielectric includes at least one high dielectric loss layer and at least one high thermal conductivity-electrically insulating layer adjacent the at least one high dielectric loss layer. A method of manufacturing a loss dielectric includes providing at least one high dielectric loss layer and providing at least one high thermal conductivity-electrically insulating layer adjacent the at least one high dielectric loss layer. The systems and methods provide advantages because the loss dielectrics are less costly and more environmentally friendly than the available alternatives.

  17. Humidifier for fuel cell using high conductivity carbon foam

    DOEpatents

    Klett, James W.; Stinton, David P.

    2006-12-12

    A method and apparatus of supplying humid air to a fuel cell is disclosed. The extremely high thermal conductivity of some graphite foams lends itself to enhance significantly the ability to humidify supply air for a fuel cell. By utilizing a high conductivity pitch-derived graphite foam, thermal conductivity being as high as 187 W/m.dot.K, the heat from the heat source is more efficiently transferred to the water for evaporation, thus the system does not cool significantly due to the evaporation of the water and, consequently, the air reaches a higher humidity ratio.

  18. Highly conductive single naphthalene and anthracene molecular junction with well-defined conductance

    SciTech Connect

    Liu, Chenyang; Kaneko, Satoshi; Komoto, Yuki; Fujii, Shintaro Kiguchi, Manabu

    2015-03-09

    We performed electronic investigation on single acene molecular junctions bridging Au-electrodes in ultra-high vacuum conditions using mechanically controllable break junction technique. While the molecular junctions displayed various conductance values at 100 K, they exhibited well-defined high conductance values (∼0.3 G{sub 0}) at 300 K, which is close to that of metal atomic contact. Direct π-binding of the molecules to the Au-electrodes leads to the high conductivities at the metal-molecule interface. At the elevated temperature, single molecular junctions trapped in local metastable structures can be fallen into energetically preferential more stable state and thus we fabricated structurally well-defined molecular junctions.

  19. A novel method for high-pressure freezing of adherent cells for frozen hydrated sectioning and CEMOVIS.

    PubMed

    Mesman, R J

    2013-09-01

    With the development of Cryo Electron Microscopy Of Vitreous Sections (CEMOVIS), imaging cells in a close to native state has become a reality. However with the commonly used carriers for high-pressure freezing and cryo-sectioning, adherent grown cells either need to be detached from their substrate. Here a new method is presented for high-pressure freezing adherent growing cells for frozen-hydrated sectioning and CEMOVIS. Cells are cultured on golden grids, containing a carbon coated Formvar film, and frozen on a membrane carrier which provides the grids with the structural support needed to withstand the strain of trimming and cryo-sectioning. This method was successfully tested for the two different types of high-pressure freezers, those using a pressure chamber (HPM010, EMHPF, Wohlwend Compact 01/02, HPM100) and those directly pressurizing the sample (EMPact series).

  20. High conductivity Be-Cu alloys for fusion reactors

    SciTech Connect

    Lilley, E.A.; Adachi, Takao; Ishibashi, Yoshiki

    1995-09-01

    The optimum material has not yet been identified. This will result in heat from plasma to the first wall and divertor. That is, because of cracks and melting by thermal power and shock. Today, it is considered to be some kinds of copper, alloys, however, for using, it must have high conductivity. And it is also needed another property, for example, high strength and so on. We have developed some new beryllium copper alloys with high conductivity, high strength, and high endurance. Therefore, we are introducing these new alloys as suitable materials for the heat sink in fusion reactors.

  1. High prevalence of medication non-adherence in a sample of community-dwelling older adults with adult protective services-validated self-neglect.

    PubMed

    Turner, Anisha; Hochschild, Ann; Burnett, Jason; Zulfiqar, Amber; Dyer, Carmel B

    2012-09-01

    Medication non-adherence can exacerbate disease severity, leading to impairments that interfere with self-care activities in older adults, and, ultimately, death. Elder self-neglect is the most common report to Adult Protective Services (APS) across the USA and is a significant risk factor for early mortality. These individuals often suffer from multiple comorbid diseases that require careful management, but for various reasons they are unwilling or unable to provide themselves with the self-care resources necessary for maintaining health and safety. No studies have assessed whether medication adherence is associated with elder self-neglect. The purpose of this study was to assess and describe medication adherence in this population, as well as evaluate associations between medication adherence and cognitive impairment, depression, physical function, and abilities to perform basic and instrumental activities of daily living (BADLs and IADLs). A cross-sectional study of 100 community-dwelling adults 65 years of age and older with APS-substantiated elder self-neglect were assessed. In-home comprehensive geriatric assessments (CGAs) were completed and included medication reviews. Information on each medication, including the amount taken from the date dispensed, was collected and used to determine adherence. The criteria for non-adherence were taking <80 or >110 % of at least one medication. The sample was also split into groups of low adherence (≤29 %), moderate adherence (29-86 %) and high adherence (≥86 %). Scores on the CGA measures Mini-Mental State Examination, Geriatric Depression Scale, Physical Performance Test (PPT) and Kohlman Evaluation of Living Skills were assessed to determine whether cognitive impairment, depression, physical function, and/or ability to perform BADLs and IADLs were associated with non-adherence or low, moderate or high levels of adherence. Twenty-five per cent of the sample was taking more than seven medications daily. The average

  2. Effective Thermal Conductivity of High Porosity Open Cell Nickel Foam

    NASA Technical Reports Server (NTRS)

    Sullins, Alan D.; Daryabeigi, Kamran

    2001-01-01

    The effective thermal conductivity of high-porosity open cell nickel foam samples was measured over a wide range of temperatures and pressures using a standard steady-state technique. The samples, measuring 23.8 mm, 18.7 mm, and 13.6 mm in thickness, were constructed with layers of 1.7 mm thick foam with a porosity of 0.968. Tests were conducted with the specimens subjected to temperature differences of 100 to 1000 K across the thickness and at environmental pressures of 10(exp -4) to 750 mm Hg. All test were conducted in a gaseous nitrogen environment. A one-dimensional finite volume numerical model was developed to model combined radiation/conduction heat transfer in the foam. The radiation heat transfer was modeled using the two-flux approximation. Solid and gas conduction were modeled using standard techniques for high porosity media. A parameter estimation technique was used in conjunction with the measured and predicted thermal conductivities at pressures of 10(exp -4) and 750 mm Hg to determine the extinction coefficient, albedo of scattering, and weighting factors for modeling the conduction thermal conductivity. The measured and predicted conductivities over the intermediate pressure values differed by 13%.

  3. Objective Measurement of Adherence to Out-Patient Airway Clearance Therapy by High-Frequency Chest Wall Compression in Cystic Fibrosis.

    PubMed

    Mikesell, Christina L; Kempainen, Robert R; Laguna, Theresa A; Menk, Jeremiah S; Wey, Andrew R; Gaillard, Philippe R; Regelmann, Warren E

    2017-07-01

    Objective measures of adherence to high-frequency chest wall compression (HFCWC), a form of airway clearance therapy for patients with cystic fibrosis, are lacking. We used a novel electronic monitoring device integrated into an HFCWC vest to measure adherence compared with self-reported adherence. We determined factors that influenced adherence and how adherence correlated with baseline pulmonary function and pulmonary exacerbations. Data were collected by direct measurement of date, time of day, and duration of HFCWC use to determine the number of daily treatments and daily duration of treatments. Chart review provided prescribed airway clearance therapy treatment and demographic and clinical information. Subject and caregiver report of the daily number of airway clearance therapy treatments was obtained by telephone interviews. Analysis used 2-sample and paired t test, analysis of variance, and linear regression. Average adherence was 69%. Adherence was highest in children (82%, P = .02) and those receiving assistance with treatment (82%, P < .001). Subjects overestimated therapy duration from a mean ± SD of 127 ± 169% by adults to 19.2 ± 26.3% by parents or guardians of children. Average adherence decreased with increasing prescribed therapy time (P = .02). Average daily therapy time and adherence had significant positive associations with baseline FEV1 percent of predicted (P = .02 and P = .02, respectively) and negative associations with pulmonary exacerbations during the pre-study period and at baseline (P = .044 and P = .02, respectively). Greater adherence to HFCWC measured directly by a novel recorder was associated with better baseline pulmonary function and fewer exacerbations in the pre-study and baseline period. Adherence decreased with age and prescribed therapy time and increased with therapy assistance. Self-report overestimation is large and thus not an accurate measure of adherence. Copyright © 2017 by Daedalus Enterprises.

  4. Process for forming adherent chromium electrodeposits from high energy efficient bath on ferrous metal substrates

    SciTech Connect

    McCullen, W.H.; Chessin, H.; Jones, A.R.

    1986-04-29

    A method is described of forming an adherent chromium deposit on a metal substrate comprising the steps of: (a) activating the substrate by electrolytically etching in an activation solution consisting essentially of a substantially neutral solution of an alkali metal sulfate, and (b) electrodepositing chromium on the thus-activated substrate.

  5. Adherence to treatment in adolescents

    PubMed Central

    Taddeo, Danielle; Egedy, Maud; Frappier, Jean-Yves

    2008-01-01

    Health care professionals must be alert to the high prevalence of low adherence to treatment during adolescence. Low adherence increases morbidity and medical complications, contributes to poorer quality of life and an overuse of the health care system. Many different factors have an impact on adherence. However, critical factors to consider in teens are their developmental stage and challenges, emotional issues and family dysfunction. Direct and indirect methods have been described to assess adherence. Eliciting an adherence history is the most useful way for clinicians to evaluate adherence, and could be the beginning of a constructive dialogue with the adolescent. Interventions to improve adherence are multiple – managing mental health issues appropriately, building a strong relationship, customizing the treatment regimen if possible, empowering the adolescent to deal with adherence issues, providing information, ensuring family and peer support, and motivational enhancement therapy. Evaluation of adherence at regular intervals should be an important aspect of health care for adolescents. PMID:19119348

  6. Process for fabricating composite material having high thermal conductivity

    DOEpatents

    Colella, Nicholas J.; Davidson, Howard L.; Kerns, John A.; Makowiecki, Daniel M.

    2001-01-01

    A process for fabricating a composite material such as that having high thermal conductivity and having specific application as a heat sink or heat spreader for high density integrated circuits. The composite material produced by this process has a thermal conductivity between that of diamond and copper, and basically consists of coated diamond particles dispersed in a high conductivity metal, such as copper. The composite material can be fabricated in small or relatively large sizes using inexpensive materials. The process basically consists, for example, of sputter coating diamond powder with several elements, including a carbide forming element and a brazeable material, compacting them into a porous body, and infiltrating the porous body with a suitable braze material, such as copper-silver alloy, thereby producing a dense diamond-copper composite material with a thermal conductivity comparable to synthetic diamond films at a fraction of the cost.

  7. Microbial metabolites are associated with a high adherence to a Mediterranean dietary pattern using a (1)H-NMR-based untargeted metabolomics approach.

    PubMed

    Almanza-Aguilera, Enrique; Urpi-Sarda, Mireia; Llorach, Rafael; Vázquez-Fresno, Rosa; Garcia-Aloy, Mar; Carmona, Francesc; Sanchez, Alex; Madrid-Gambin, Francisco; Estruch, Ramon; Corella, Dolores; Andres-Lacueva, Cristina

    2017-10-01

    The study of biomarkers of dietary patterns including the Mediterranean diet (MedDiet) is scarce and could improve the assessment of these patterns. Moreover, it could provide a better understanding of health benefits of dietary patterns in nutritional epidemiology. We aimed to determine a robust and accurate biomarker associated with a high adherence to a MedDiet pattern that included dietary assessment and its biological effect. In this cross-sectional study, we included 56 and 63 individuals with high (H-MDA) and low (L-MDA) MedDiet adherence categories, respectively, all from the Prevención con Dieta Mediterránea trial. A (1)H-NMR-based untargeted metabolomics approach was applied to urine samples. Multivariate statistical analyses were conducted to determine the metabolite differences between groups. A stepwise logistic regression and receiver operating characteristic curves were used to build and evaluate the prediction model for H-MDA. Thirty-four metabolites were identified as discriminant between H-MDA and L-MDA. The fingerprint associated with H-MDA included higher excretion of proline betaine and phenylacetylglutamine, among others, and decreased amounts of metabolites related to glucose metabolism. Three microbial metabolites - phenylacetylglutamine, p-cresol and 4-hydroxyphenylacetate - were included in the prediction model of H-MDA (95% specificity, 95% sensitivity and 97% area under the curve). The model composed of microbial metabolites was the biomarker that defined high adherence to a Mediterranean dietary pattern. The overall metabolite profiling identified reflects the metabolic modulation produced by H-MDA. The proposed biomarker may be a better tool for assessing and aiding nutritional epidemiology in future associations between H-MDA and the prevention or amelioration of chronic diseases. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Flexible Fabrics with High Thermal Conductivity for Advanced Spacesuits

    NASA Technical Reports Server (NTRS)

    Trevino, Luis A.; Bue, Grant; Orndoff, Evelyne; Kesterson, Matt; Connel, John W.; Smith, Joseph G., Jr.; Southward, Robin E.; Working, Dennis; Watson, Kent A.; Delozier, Donovan M.

    2006-01-01

    This paper describes the effort and accomplishments for developing flexible fabrics with high thermal conductivity (FFHTC) for spacesuits to improve thermal performance, lower weight and reduce complexity. Commercial and additional space exploration applications that require substantial performance enhancements in removal and transport of heat away from equipment as well as from the human body can benefit from this technology. Improvements in thermal conductivity were achieved through the use of modified polymers containing thermally conductive additives. The objective of the FFHTC effort is to significantly improve the thermal conductivity of the liquid cooled ventilation garment by improving the thermal conductivity of the subcomponents (i.e., fabric and plastic tubes). This paper presents the initial system modeling studies, including a detailed liquid cooling garment model incorporated into the Wissler human thermal regulatory model, to quantify the necessary improvements in thermal conductivity and garment geometries needed to affect system performance. In addition, preliminary results of thermal conductivity improvements of the polymer components of the liquid cooled ventilation garment are presented. By improving thermal garment performance, major technology drivers will be addressed for lightweight, high thermal conductivity, flexible materials for spacesuits that are strategic technical challenges of the Exploration

  9. Flexible Fabrics with High Thermal Conductivity for Advanced Spacesuits

    NASA Technical Reports Server (NTRS)

    Trevino, Luis A.; Bue, Grant; Orndoff, Evelyne; Kesterson, Matt; Connel, John W.; Smith, Joseph G., Jr.; Southward, Robin E.; Working, Dennis; Watson, Kent A.; Delozier, Donovan M.

    2006-01-01

    This paper describes the effort and accomplishments for developing flexible fabrics with high thermal conductivity (FFHTC) for spacesuits to improve thermal performance, lower weight and reduce complexity. Commercial and additional space exploration applications that require substantial performance enhancements in removal and transport of heat away from equipment as well as from the human body can benefit from this technology. Improvements in thermal conductivity were achieved through the use of modified polymers containing thermally conductive additives. The objective of the FFHTC effort is to significantly improve the thermal conductivity of the liquid cooled ventilation garment by improving the thermal conductivity of the subcomponents (i.e., fabric and plastic tubes). This paper presents the initial system modeling studies, including a detailed liquid cooling garment model incorporated into the Wissler human thermal regulatory model, to quantify the necessary improvements in thermal conductivity and garment geometries needed to affect system performance. In addition, preliminary results of thermal conductivity improvements of the polymer components of the liquid cooled ventilation garment are presented. By improving thermal garment performance, major technology drivers will be addressed for lightweight, high thermal conductivity, flexible materials for spacesuits that are strategic technical challenges of the Exploration

  10. Mobile Phone Apps to Improve Medication Adherence: A Systematic Stepwise Process to Identify High-Quality Apps.

    PubMed

    Santo, Karla; Richtering, Sarah S; Chalmers, John; Thiagalingam, Aravinda; Chow, Clara K; Redfern, Julie

    2016-12-02

    There are a growing number of mobile phone apps available to support people in taking their medications and to improve medication adherence. However, little is known about how these apps differ in terms of features, quality, and effectiveness. We aimed to systematically review the medication reminder apps available in the Australian iTunes store and Google Play to assess their features and their quality in order to identify high-quality apps. This review was conducted in a similar manner to a systematic review by using a stepwise approach that included (1) a search strategy; (2) eligibility assessment; (3) app selection process through an initial screening of all retrieved apps and full app review of the included apps; (4) data extraction using a predefined set of features considered important or desirable in medication reminder apps; (5) analysis by classifying the apps as basic and advanced medication reminder apps and scoring and ranking them; and (6) a quality assessment by using the Mobile App Rating Scale (MARS), a reliable tool to assess mobile health apps. We identified 272 medication reminder apps, of which 152 were found only in Google Play, 87 only in iTunes, and 33 in both app stores. Apps found in Google Play had more customer reviews, higher star ratings, and lower cost compared with apps in iTunes. Only 109 apps were available for free and 124 were recently updated in 2015 or 2016. Overall, the median number of features per app was 3.0 (interquartile range 4.0) and only 18 apps had ≥9 of the 17 desirable features. The most common features were flexible scheduling that was present in 56.3% (153/272) of the included apps, medication tracking history in 54.8% (149/272), snooze option in 34.9% (95/272), and visual aids in 32.4% (88/272). We classified 54.8% (149/272) of the included apps as advanced medication reminder apps and 45.2% (123/272) as basic medication reminder apps. The advanced apps had a higher number of features per app compared with the

  11. Mobile Phone Apps to Improve Medication Adherence: A Systematic Stepwise Process to Identify High-Quality Apps

    PubMed Central

    Richtering, Sarah S; Chalmers, John; Thiagalingam, Aravinda; Chow, Clara K; Redfern, Julie

    2016-01-01

    Background There are a growing number of mobile phone apps available to support people in taking their medications and to improve medication adherence. However, little is known about how these apps differ in terms of features, quality, and effectiveness. Objective We aimed to systematically review the medication reminder apps available in the Australian iTunes store and Google Play to assess their features and their quality in order to identify high-quality apps. Methods This review was conducted in a similar manner to a systematic review by using a stepwise approach that included (1) a search strategy; (2) eligibility assessment; (3) app selection process through an initial screening of all retrieved apps and full app review of the included apps; (4) data extraction using a predefined set of features considered important or desirable in medication reminder apps; (5) analysis by classifying the apps as basic and advanced medication reminder apps and scoring and ranking them; and (6) a quality assessment by using the Mobile App Rating Scale (MARS), a reliable tool to assess mobile health apps. Results We identified 272 medication reminder apps, of which 152 were found only in Google Play, 87 only in iTunes, and 33 in both app stores. Apps found in Google Play had more customer reviews, higher star ratings, and lower cost compared with apps in iTunes. Only 109 apps were available for free and 124 were recently updated in 2015 or 2016. Overall, the median number of features per app was 3.0 (interquartile range 4.0) and only 18 apps had ≥9 of the 17 desirable features. The most common features were flexible scheduling that was present in 56.3% (153/272) of the included apps, medication tracking history in 54.8% (149/272), snooze option in 34.9% (95/272), and visual aids in 32.4% (88/272). We classified 54.8% (149/272) of the included apps as advanced medication reminder apps and 45.2% (123/272) as basic medication reminder apps. The advanced apps had a higher number

  12. Assessing adherence to teriparatide therapy, causes of nonadherence and effect of adherence on bone mineral density measurements in osteoporotic patients at high risk for fracture.

    PubMed

    Mulgund, Manisha; Beattie, Karen A; Wong, Andy K O; Papaioannou, Alexandra; Adachi, Jonathan D

    2009-02-01

    To determine (a) adherence rates at 6, 9 and 18 months amongst patients receiving teriparatide treatment for severe osteoporosis and (b) causes of therapy discontinuation and the effect of teriparatide on bone mineral density (BMD) in adherent and nonadherent patients at different time intervals. A retrospective chart review of 111 patients receiving teriparatide from September 2004 to June 2007 was performed. Patients self-reports were used to record adherence and causes of nonadherence at 6, 9 and 18 months. BMDs for all patients were measured using the same DXA scanner at baseline and follow up. Of 111 participants, 17 were male (mean age 60 years) and 94 were female (mean age 69 years). Of these, 12 did not initiate therapy and 4 were lost to follow up. Reported adherence was 89.6% at 6 months, 87.6% at 9 months and 74.7% at 18 months. Causes of nonadherence included cost (n = 4), no benefit (n = 1) and adverse events (n = 8). Common adverse events were leg cramps (n = 9), headache (n = 5) and myalgia (n = 4). Mean spine and femur BMD changes were 3.30% and 0.67% at 4-9 months respectively, and 5.39% and 0.77% at 10-18 months respectively. Adherence to teriparatide was almost 90% at 9 months and decreased to 75% at 18 months. Adverse events led to nonadherence in 20% of patients. Those who were nonadherent had lower baseline BMD values than those who were adherent. Changes in BMD at the lumbar spine were greater than changes observed at the femoral neck.

  13. Divalent beta aluminas: High conductivity solid electrolytes for divalent cations

    NASA Astrophysics Data System (ADS)

    Farrington, G. C.; Dunn, B.

    1982-10-01

    The Na(+) content of beta alumina can be replaced by a variety of divalent cations in simple ion exchange reactions. The resulting divalent beta' aluminas are the first family of high conductivity solid electrolytes for divalent cations. Divalent beta' aluminas which have been prepared so far include conductors of Ca(2+), Sr(2+), Ba(2+), Zn(2+), Cd(2+), Pb(2+), Hg(2+), and Mn(2+). Most have conductivities of about 0.1/(ohm-cm) at 300-400 C. However, the conductivity of Pb(++) beta alumina is 0.0046/(ohm-cm) at 40 C, nearly equal to that of Na(+) beta alumina. Preliminary structure studies indicate that order-disorder reactions among the divalent cations and vacancies in the conduction region of beta alumina critically influence conductivity in the structure.

  14. Stretchable fine fiber with high conductivity fabricated by injection forming

    NASA Astrophysics Data System (ADS)

    Wakuda, Daisuke; Suganuma, Katsuaki

    2011-02-01

    Stretchable conductors are necessary to realize soft and rubbery electronics. A stretchable fine fiber with high conductivity was fabricated by a injection forming. The fiber is made of silicone series conductive adhesive containing Ag flake fillers. The fiber has uniform diameter without any substrate and has very long length by the injection forming method. The diameters can be controlled by changing the bore diameter of the injection needle. Furthermore, the fine fiber, 230 μm in diameter, maintains excellent conductivity under cyclic tensile stress. The conductivity is approximately 470 S/cm without tensile stress and maintains over 90 S/cm under cyclic tensile test which is stretched up to 10% strain. The result exhibits a great potential of the conductive fine fiber as a stretchable conductor.

  15. High Thermal Conducting Boron Arsenide: Crystal Growth and Characterization

    NASA Astrophysics Data System (ADS)

    Lv, Bing; Lan, Yucheng; Wang, Xiqu; Zhang, Qian; Hu, Yongjie; Jacobson, Allan J.; Broido, David; Chen, Gang; Ren, Zhifeng; Chu, Ching-Wu

    2015-03-01

    Intrigued by recent calculations [Phys. Rev. Lett. 111, 025901(2013)] which predict a remarkably high thermal conductivity of ~ 2,000 Wm-1K-1 , comparable to that of diamond, in cubic boron arsenide (BAs) crystals, we have succeeded in synthesizing single crystals of BAs with a zinc blende structure and lattice parameters of a = 4.7830(7) Å characterized by X-ray single crystal diffraction and transmission electron microscopy (TEM). A relatively high thermal conductivity is obtained but still smaller than the predicted value. We attribute the difference of thermal conductivity value to the defect scattering associated with crystal twinning and As vacancies, verified both from experimental evidence and theoretical calculations. The predicted super-thermal-conductivity may be achieved in BAs single crystals with further improvement of crystal growth by removing the defects. Lawrence Berkeley National Laboratory, Berkeley California 94720.

  16. Rethinking adherence.

    PubMed

    Steiner, John F

    2012-10-16

    In 2012, the Centers for Medicare & Medicaid Services (CMS) will introduce measures of adherence to oral hypoglycemic, antihypertensive, and cholesterol-lowering drugs into its Medicare Advantage quality program. To meet these quality goals, delivery systems will need to develop and disseminate strategies to improve adherence. The design of adherence interventions has too often been guided by the mistaken assumptions that adherence is a single behavior that can be predicted from readily available patient characteristics and that individual clinicians alone can improve adherence at the population level.Effective interventions require recognition that adherence is a set of interacting behaviors influenced by individual, social, and environmental forces; adherence interventions must be broadly based, rather than targeted to specific population subgroups; and counseling with a trusted clinician needs to be complemented by outreach interventions and removal of structural and organizational barriers. To achieve the adherence goals set by CMS, front-line clinicians, interdisciplinary teams, organizational leaders, and policymakers will need to coordinate efforts in ways that exemplify the underlying principles of health care reform.

  17. High conductivity magnetic tearing instability. [of neutral plasma sheets

    NASA Technical Reports Server (NTRS)

    Cross, M. A.; Van Hoven, G.

    1976-01-01

    Linearized equations of magnetohydrodynamics are used to investigate the tearing mode, for arbitrary values of the conductivity, through a consideration of the additional effect of the electron-inertia contribution to Ohm's law. A description is provided of the equilibrium and subsequent instability in the magnetohydrodynamic approximation. A method for solving the perturbation equations in the linear approximation is discussed and attention is given to the results in the high conductivity limit.

  18. Highly adherent bioactive glass thin films synthetized by magnetron sputtering at low temperature.

    PubMed

    Stan, G E; Pasuk, I; Husanu, M A; Enculescu, I; Pina, S; Lemos, A F; Tulyaganov, D U; El Mabrouk, K; Ferreira, J M F

    2011-12-01

    Thin (380-510 nm) films of a low silica content bioglass with MgO, B(2)O(3), and CaF(2) as additives were deposited at low-temperature (150°C) by radio-frequency magnetron sputtering onto titanium substrates. The influence of sputtering conditions on morphology, structure, composition, bonding strength and in vitro bioactivity of sputtered bioglass films was investigated. Excellent pull-out adherence (~73 MPa) was obtained when using a 0.3 Pa argon sputtering pressure (BG-a). The adherence declined (~46 MPa) upon increasing the working pressure to 0.4 Pa (BG-b) or when using a reactive gas mixture (~50 MPa). The SBF tests clearly demonstrated strong biomineralization features for all bioglass sputtered films. The biomineralization rate increased from BG-a to BG-b, and yet more for BG-c. A well-crystallized calcium hydrogen phosphate-like phase was observed after 3 and 15 days of immersion in SBF in all bioglass layers, which transformed monotonously into hydroxyapatite under prolonged SBF immersion. Alkali and alkali-earth salts (NaCl, KCl and CaCO(3)) were also found at the surface of samples soaked in SBF for 30 days. The study indicated that features such as composition, structure, adherence and bioactivity of bioglass films can be tailored simply by altering the magnetron sputtering working conditions, proving that this less explored technique is a promising alternative for preparing implant-type coatings.

  19. Highly Conductive Wire: Cu Carbon Nanotube Composite Ampacity and Metallic CNT Buckypaper Conductivity

    NASA Technical Reports Server (NTRS)

    de Groh, Henry C.

    2017-01-01

    NASA is currently working on developing motors for hybrid electric propulsion applications in aviation. To make electric power more feasible in airplanes higher power to weight ratios are sought for electric motors. One facet to these efforts is to improve (increase) the conductivity and (lower) density of the magnet wire used in motors. Carbon nanotubes (CNT) and composites containing CNT are being explored as a possible way to increase wire conductivity and lower density. Presented here are measurements of the current carrying capacity (ampacity) of a composite made from CNT and copper. The ability of CNT to improve the conductivity of such composites is hindered by the presence of semiconductive CNT (s-CNT) that exist in CNT supplies naturally, and currently, unavoidably. To solve this problem, and avoid s-CNT, various preferential growth and sorting methods are being explored. A supply of sorted 95 metallic CNT (m-CNT) was acquired in the form of thick film Buckypaper (BP) as part of this work and characterized using Raman spectroscopy, resistivity, and density measurements. The ampacity (Acm2) of the Cu-5volCNT composite was 3.8 lower than the same gauge pure Cu wire similarly tested. The lower ampacity in the composite wire is believed to be due to the presence of s-CNT in the composite and the relatively low (proper) level of longitudinal cooling employed in the test method. Although Raman spectroscopy can be used to characterize CNT, a strong relation between the ratios of the primary peaks GGand the relative amounts of m-CNT and s-CNT was not observed. The average effective conductivity of the CNT in the sorted, 95 m-CNT BP was 2.5 times higher than the CNT in the similar but un-sorted BP. This is an indication that improvements in the conductivity of CNT composites can be made by the use of sorted, highly conductive m-CNT.

  20. Acceptability and adherence of a candidate microbicide gel among high-risk women in Africa and India.

    PubMed

    Greene, Elizabeth; Batona, Georges; Hallad, Jyoti; Johnson, Sethulakshmi; Neema, Stella; Tolley, Elizabeth E

    2010-10-01

    Vaginal microbicides currently under development are substances that may prevent the transmission of HIV. Qualitative, in-depth post-trial interview data from a Phase III clinical trial of 6% Cellulose Sulfate microbicide gel in two sites in Africa (Uganda and Benin) and two in India (Chennai and Bagalkot) were examined in order to better understand factors that influence microbicide acceptability and adherence in a clinical trial setting. Women found the gel relatively easy to use with partners with whom there were no expectations of fidelity, in situations where they had access to private space and at times when they were expecting to engage in sexual intercourse. Adherence to gel seemed significantly more difficult with primary partners due to decreased perceptions of risk, inconvenience or fear of partner disapproval. Findings suggest that women in a variety of settings may find a microbicide gel to be highly acceptable for its lubricant qualities and protective benefits but that adherence and consistent use may depend greatly on contextual and partner-related factors. These findings have important implications for future trial designs, predicting determinants of microbicide use and acceptability and marketing and educational efforts should a safe and efficacious microbicide be found.

  1. High Adherence to CPAP Treatment Does Not Prevent the Continuation of Weight Gain among Severely Obese OSAS Patients

    PubMed Central

    Myllylä, Minna; Kurki, Samu; Anttalainen, Ulla; Saaresranta, Tarja; Laitinen, Tarja

    2016-01-01

    Study Objectives: Obstructive sleep apnea syndrome (OSAS) patients benefit from continuous positive airway pressure (CPAP) treatment in a dose-response manner. We determined adherence and weight control, as well as their predictors, among long-term CPAP users. Methods: Cohort of 1,023 OSAS patients had used CPAP on average of 6.6 ± 1.2 years. BMI was determined at baseline and at follow-up visits. There were 7.4 ± 1.7 BMI and 6.5 ± 1.8 CPAP usage measurements per patient on average. Using the Bayesian hierarchical model, we determined the patients' individual trends of BMI and adherence development. Patients with significantly increasing or decreasing trends were identified at the posterior probability level of > 90%. Results: The mean age in the cohort was 55.6 ± 9.8 years, BMI 33.5 ± 6.4 kg/m2, apnea-hypopnea index 33.7 ± 23.1, and CPAP usage 6.0 ± 1.8 h/day. The majority of patients had no significant change in BMI (mean annual weight gain 0.04 ± 0.29 kg/m2) or CPAP adherence (mean annual increase 11.4 ± 7.0 min/day). However, at the individual level, 10% of the patients showed significant annual weight gain (0.63 ± 0.35 kg/m2) during the 5-year follow-up period. At baseline these patients were already more severely obese (mean BMI 40.0 ± 5.9 kg/m2) despite being younger (mean 50.9 ± 9.5 years) than the rest of the cohort. Conclusions: In the majority of CPAP-treated OSAS patients, weight did not significantly change but gained slightly slower than in age-matched population in general. However, in 10% of patients, high adherence to CPAP treatment did not prevent the continuation of weight gain. These patients present a high-risk group for OSAS-related multimorbidity later in life. Citation: Myllylä M, Kurki S, Anttalainen U, Saaresranta T, Laitinen T. High adherence to CPAP treatment does not prevent the continuation of weight gain among severely obese OSAS patients. J Clin Sleep Med 2016;12(4):519–528. PMID:26888588

  2. [Cardiovascular recovery during intermittent exercise in highly-adherent partic pants with hypertension and type 2 diabetes mellitus].

    PubMed

    Cano-Montoya, Johnattan; Álvarez, Cristian; Martínez, Cristian; Salas, Andrés; Sade, Farid; Ramírez-Campillo, Rodrigo

    2016-09-01

    Despite the evidence supporting metabolic benefits of high intensity interval exercise (HIIT), there is little information about the cardiovascular response to this type of exercise in patients with type 2 diabetes (T2D) and hypertension (HTA). To analyze the changes in heart rate at rest, at the onset and at the end of each interval of training, after twelve weeks of a HIIT program in T2D and HTA patients. Twenty-three participants with T2D and HTA (20 women) participated in a controlled HIIT program. Fourteen participants attended 90% of more session of exercise and were considered as adherent. Adherent and non-adherent participants had similar body mass index (BMI), and blood pressure. A “1x2x10” (work: rest-time: intervals) HIIT exercise protocol was used both as a test and as training method during twelve weeks. The initial and finishing heart rate (HR) of each of the ten intervals before and after the intervention were measured. After twelve weeks of HIIT intervention, adherent participants had a significant reduction in the heart rate at the onset of exercise, and during intervals 4, 5, 8 and 10. A reduction in the final heart rate was observed during intervals 8 and 10. In the same participants the greatest magnitude of reduction, at the onset or end of exercise was approximately 10 beats/min. No significant changes in BMI, resting heart rate and blood pressure were observed. A HIIT program reduces the cardiovascular effort to a given work-load and improves cardiovascular recovery after exercise.

  3. High thermal conductivity in electrostatically engineered amorphous polymers

    PubMed Central

    Shanker, Apoorv; Li, Chen; Kim, Gun-Ho; Gidley, David; Pipe, Kevin P.; Kim, Jinsang

    2017-01-01

    High thermal conductivity is critical for many applications of polymers (for example, packaging of light-emitting diodes), in which heat must be dissipated efficiently to maintain the functionality and reliability of a system. Whereas uniaxially extended chain morphology has been shown to significantly enhance thermal conductivity in individual polymer chains and fibers, bulk polymers with coiled and entangled chains have low thermal conductivities (0.1 to 0.4 W m−1 K−1). We demonstrate that systematic ionization of a weak anionic polyelectrolyte, polyacrylic acid (PAA), resulting in extended and stiffened polymer chains with superior packing, can significantly enhance its thermal conductivity. Cross-plane thermal conductivity in spin-cast amorphous films steadily grows with PAA degree of ionization, reaching up to ~1.2 W m−1 K−1, which is on par with that of glass and about six times higher than that of most amorphous polymers, suggesting a new unexplored molecular engineering strategy to achieve high thermal conductivities in amorphous bulk polymers. PMID:28782022

  4. Silicon-graphene conductive photodetector with ultra-high responsivity

    PubMed Central

    Liu, Jingjing; Yin, Yanlong; Yu, Longhai; Shi, Yaocheng; Liang, Di; Dai, Daoxin

    2017-01-01

    Graphene is attractive for realizing optoelectronic devices, including photodetectors because of the unique advantages. It can easily co-work with other semiconductors to form a Schottky junction, in which the photo-carrier generated by light absorption in the semiconductor might be transported to the graphene layer efficiently by the build-in field. It changes the graphene conduction greatly and provides the possibility of realizing a graphene-based conductive-mode photodetector. Here we design and demonstrate a silicon-graphene conductive photodetector with improved responsivity and response speed. An electrical-circuit model is established and the graphene-sheet pattern is designed optimally for maximizing the responsivity. The fabricated silicon-graphene conductive photodetector shows a responsivity of up to ~105 A/W at room temperature (27 °C) and the response time is as short as ~30 μs. The temperature dependence of the silicon-graphene conductive photodetector is studied for the first time. It is shown that the silicon-graphene conductive photodetector has ultra-high responsivity when operating at low temperature, which provides the possibility to detect extremely weak optical power. For example, the device can detect an input optical power as low as 6.2 pW with the responsivity as high as 2.4 × 107 A/W when operating at −25 °C in our experiment. PMID:28106084

  5. Development of a high conductivity intercalated graphite composite wire

    SciTech Connect

    Singhal, S.C.

    1982-02-01

    Beginning in May 1979, the Department of Energy initiated the present program entitled, Development of a High Conductivity Intercalated Graphite Composite Wire, to develop the scientific base and technology for reproducibly fabricating high conductivity intercalated graphite composite wires. Toward achieving this objective, the following work was carried out in this program: (1) composite wires previously fabricated by swaging at the University of Pennsylvania and claimed to possess conductivity equal to or greater than that of copper were analyzed, (2) intercalation of HOPG crystals with SbF/sub 5/+HF mixtures was studied to assess the effect of defects in the starting graphite on the final conductivity and also to determine the conductivity as a function of the stage of the compound, and (3) composite wires consisting of copper, aluminum or lead outer sheath and SbF/sub 5/+HF- or AsF/sub 5/-intercalated graphite in the core were fabricated by swaging and/or drawing and then analyzed for their electrical conductivity.

  6. Silicon-graphene conductive photodetector with ultra-high responsivity

    NASA Astrophysics Data System (ADS)

    Liu, Jingjing; Yin, Yanlong; Yu, Longhai; Shi, Yaocheng; Liang, Di; Dai, Daoxin

    2017-01-01

    Graphene is attractive for realizing optoelectronic devices, including photodetectors because of the unique advantages. It can easily co-work with other semiconductors to form a Schottky junction, in which the photo-carrier generated by light absorption in the semiconductor might be transported to the graphene layer efficiently by the build-in field. It changes the graphene conduction greatly and provides the possibility of realizing a graphene-based conductive-mode photodetector. Here we design and demonstrate a silicon-graphene conductive photodetector with improved responsivity and response speed. An electrical-circuit model is established and the graphene-sheet pattern is designed optimally for maximizing the responsivity. The fabricated silicon-graphene conductive photodetector shows a responsivity of up to ~105 A/W at room temperature (27 °C) and the response time is as short as ~30 μs. The temperature dependence of the silicon-graphene conductive photodetector is studied for the first time. It is shown that the silicon-graphene conductive photodetector has ultra-high responsivity when operating at low temperature, which provides the possibility to detect extremely weak optical power. For example, the device can detect an input optical power as low as 6.2 pW with the responsivity as high as 2.4 × 107 A/W when operating at ‑25 °C in our experiment.

  7. Survey of Processing Methods for High Strength High Conductivity Wires for High Field Magnet Applications

    SciTech Connect

    Han, K.; Embury, J.D.

    1998-10-01

    This paper will deal with the basic concepts of attaining combination of high strength and high conductivity in pure materials, in-situ composites and macrocomposites. It will survey current attainments, and outline where some future developments may lie in developing wire products that are close to the theoretical strength of future magnet applications.

  8. High conductivity transparent carbon nanotube films deposited from superacid.

    PubMed

    Hecht, David S; Heintz, Amy M; Lee, Roland; Hu, Liangbing; Moore, Bryon; Cucksey, Chad; Risser, Steven

    2011-02-18

    Carbon nanotubes (CNTs) were deposited from a chlorosulfonic superacid solution onto PET substrates by a filtration/transfer method. The sheet resistance and transmission (at 550 nm) of the films were 60 Ω/sq and 90.9% respectively, which corresponds to a DC conductivity of 12,825 S cm(-1) and a DC/optical conductivity ratio of 64.1. This is the highest DC conductivity reported for CNT thin films to date, and attributed to both the high quality of the CNT material and the exfoliation/doping by the superacid. This work demonstrates that CNT transparent films have not reached the conductivity limit; continued improvements will enable these films to be used as the transparent electrode for applications in solid state lighting, LCD displays, touch panels, and photovoltaics.

  9. High conductivity, low cost aluminum composite for thermal management

    SciTech Connect

    Sommer, J.L.

    1997-04-01

    In order to produce an inexpensive packaging material that exhibits high thermal conductivity and low CTE, Technical Research Associates, Inc. (TRA) has shown in Phase I the feasibility of incorporating natural flake graphite in an aluminum matrix. TRA has developed a proprietary coating technique where graphite flakes have been coated with a thin layer of molybdenum/molybdenum carbide (approximately 0.2 microns). This barrier coating can protect the graphite flake from chemical reaction and high temperature degradation in molten aluminum silicon alloys. Methods to successfully vacuum infiltrate coated flake with molten aluminum alloys were developed. The resulted metal matrix composites exhibited lower CTE than aluminum metal. The CTE of the composites were significantly lower than aluminum and its alloys. The CTE can potentially be tailored for specific applications. The in plane thermal conductivity was higher than the aluminum matrix alloy. The thermal conductivity and CTE of the composite may be significantly improved by improving the bond strength of the molybdenum coating on the graphite flake. The flake can potentially be incorporated in the molten aluminum and pressure die cast to align the flakes within the aluminum matrix. By preferentially aligning high conductivity graphite flakes within a plane or direction, the thermal conductivity of the resulting composite will be above pure aluminum in the alignment direction.

  10. Ultra high Transparent and Conductive Electrodes Based on As-Grown SWNT with Metallic Conductivity

    NASA Astrophysics Data System (ADS)

    Paronyan, Tereza; Pigos, Elena; Chen, Gugang; Harutyunyan, Avetik

    2012-02-01

    Carbon based materials have been proven to be a unique material for transparent conducting films, with potential for application on liquid crystal displays, touch screens and solar cells. We successfully grew SWNT films by Chemical Vapor Deposition method using Fe nanocatalysts on quartz substrates. The ratio of semiconductor/metallic nanotubes varied depending on the treatment conditions of the catalyst nanoparticles, according to Raman analysis. SEM analysis of the samples revealed homogeneous coverage of the quartz substrates by SWNTs, which exhibit transparencies higher than 98%. Sheet resistance measurements of these SWNT films, by Van der Pauw method, demonstrated the correlation between the conductivity and the abundance of semiconductor and metallic nanotubes in the films. Increasing the content of metallic SWNTs in the film up to 90% decreased the sheet resistance down to 4-5 Kφ/, while maintaining a high transparency of over 98%. For comparison, transparent electrodes based on high quality monolayer graphene sheets were also fabricated. The conductivity and transparency of the electrodes of as grown SWNTs were comparable to the electrodes based on monolayer graphene.

  11. High ionic conductivity in confined bismuth oxide-based heterostructures

    NASA Astrophysics Data System (ADS)

    Sanna, Simone; Esposito, Vincenzo; Christensen, Mogens; Pryds, Nini

    2016-12-01

    Bismuth trioxide in the cubic fluorite phase ( δ - Bi 2 O 3 ) exhibits the highest oxygen ionic conductivity. In this study, we were able to stabilize the pure δ - Bi 2 O 3 at low temperature with no addition of stabilizer but only by engineering the interface, using highly coherent heterostructures made of alternative layers of δ - Bi 2 O 3 and Yttria Stabilized Zirconia (YSZ), deposited by pulsed laser deposition. The resulting [ δ - Bi 2 O 3 / YSZ ] heterostructures are found to be stable over a wide temperature range (500-750 °C) and exhibits stable high ionic conductivity over a long time comparable to the value of the pure δ - Bi 2 O 3 , which is approximately two orders of magnitude higher than the conductivity of YSZ bulk.

  12. Hybrid electrokinetic manipulation in high-conductivity media.

    PubMed

    Gao, Jian; Sin, Mandy L Y; Liu, Tingting; Gau, Vincent; Liao, Joseph C; Wong, Pak Kin

    2011-05-21

    This study reports a hybrid electrokinetic technique for label-free manipulation of pathogenic bacteria in biological samples toward medical diagnostic applications. While most electrokinetic techniques only function in low-conductivity buffers, hybrid electrokinetics enables effective operation in high-conductivity samples, such as physiological fluids (∼1 S m(-1)). The hybrid electrokinetic technique combines short-range electrophoresis and dielectrophoresis, and long-range AC electrothermal flow to improve its effectiveness. The major technical hurdle of electrode instability for manipulating high conductivity samples is tackled by using a Ti-Au-Ti sandwich electrode and a 3-parallel-electrode configuration is designed for continuous isolation of bacteria. The device operates directly with biological samples including urine and buffy coats. We show that pathogenic bacteria and biowarfare agents can be concentrated for over 3 orders of magnitude using hybrid electrokinetics.

  13. Deep-level transient conductance spectroscopy of high resistivity semiconductors

    NASA Astrophysics Data System (ADS)

    Alexiev, Dimitri; Prokopovich, Dale; Reinhard, Mark I.; Thomson, Stuart; Mo, Li

    2005-03-01

    We describe a deep-level transient-conductance (DLTC) spectrometer for high resistivity semiconductors, which uses a radiofrequency (40 MHz) marginal oscillator as conductance detector. The DLTC spectra are generated by periodically filling the deep-level trapping centres by carriers stimulated by a pulsed GaAs laser. Then the trap-emptying conductance's signal process through an exponential Miller correlator as the sample temperature is slowly ramped. A simple capacitive coupling of the samples to the oscillator tank circuit eliminates problems such as unwanted defect annealing and other material changes often associated with the high-temperature techniques necessary for ohmic contact formation. Representative deep-level spectra for CdTe, CdZnTe, HgI and gamma-irradiated Si are given.

  14. Cognitive function and adherence to anticoagulation treatment in patients with atrial fibrillation

    PubMed Central

    Jankowska-Polańska, Beata; Katarzyna, Lomper; Lidia, Alberska; Joanna, Jaroch; Dudek, Krzysztof; Izabella, Uchmanowicz

    2016-01-01

    Background Medication adherence is an integral part of the comprehensive care of patients with atrial fibrillation (AF) receiving oral anticoagulations (OACs) therapy. Many patients with AF are elderly and may suffer from some form of cognitive impairment. This study was conducted to investigate whether cognitive impairment affects the level of adherence to anticoagulation treatment in AF patients. Methods The study involved 111 AF patients (mean age, 73.5 ± 8.3 years) treated with OACs. Cognitive function was assessed using the Mini Mental State Examination (MMSE). The level of adherence was assessed by the 8-item Morisky Medication Adherence Scale (MMAS-8). Scores on the MMAS-8 range from 0 to 8, with scores < 6 reflecting low adherence, 6 to < 8 medium adherence, and 8 high adherence. Results 46.9% of AF patients had low adherence, 18.8% had moderate adherence, and 33.3% had high adherence to OACs. Patients with lower adherence were older than those with moderate or high adherence (76.6 ± 8.7 vs. 71.3 ± 6.4 vs. 71.1 ± 6.7 years) and obtained low MMSE scores, indicating cognitive disorders or dementia (MMSE = 22.3 ± 4.2). Patients with moderate or high adherence obtained high MMSE test results (27.5 ± 1.7 and 27.5 ± 3.6). According to Spearman's rank correlation, worse adherence to treatment with OACs was determined by older age (rS = −0.372) and lower MMSE scores (rS = 0.717). According to multivariate regression analysis, the level of cognitive function was a significant independent predictor of adherence (b = 1.139). Conclusions Cognitive impairment is an independent determinant of compliance with pharmacological therapy in elderly patients with AF. Lower adherence, beyond the assessment of cognitive function, is related to the age of patients. PMID:27605935

  15. Cognitive function and adherence to anticoagulation treatment in patients with atrial fibrillation.

    PubMed

    Jankowska-Polańska, Beata; Katarzyna, Lomper; Lidia, Alberska; Joanna, Jaroch; Dudek, Krzysztof; Izabella, Uchmanowicz

    2016-07-01

    Medication adherence is an integral part of the comprehensive care of patients with atrial fibrillation (AF) receiving oral anticoagulations (OACs) therapy. Many patients with AF are elderly and may suffer from some form of cognitive impairment. This study was conducted to investigate whether cognitive impairment affects the level of adherence to anticoagulation treatment in AF patients. The study involved 111 AF patients (mean age, 73.5 ± 8.3 years) treated with OACs. Cognitive function was assessed using the Mini Mental State Examination (MMSE). The level of adherence was assessed by the 8-item Morisky Medication Adherence Scale (MMAS-8). Scores on the MMAS-8 range from 0 to 8, with scores < 6 reflecting low adherence, 6 to < 8 medium adherence, and 8 high adherence. 46.9% of AF patients had low adherence, 18.8% had moderate adherence, and 33.3% had high adherence to OACs. Patients with lower adherence were older than those with moderate or high adherence (76.6 ± 8.7 vs. 71.3 ± 6.4 vs. 71.1 ± 6.7 years) and obtained low MMSE scores, indicating cognitive disorders or dementia (MMSE = 22.3 ± 4.2). Patients with moderate or high adherence obtained high MMSE test results (27.5 ± 1.7 and 27.5 ± 3.6). According to Spearman's rank correlation, worse adherence to treatment with OACs was determined by older age (rS = -0.372) and lower MMSE scores (rS = 0.717). According to multivariate regression analysis, the level of cognitive function was a significant independent predictor of adherence (b = 1.139). Cognitive impairment is an independent determinant of compliance with pharmacological therapy in elderly patients with AF. Lower adherence, beyond the assessment of cognitive function, is related to the age of patients.

  16. Engineering Graphene Conductivity for Flexible and High-Frequency Applications.

    PubMed

    Samuels, Alexander J; Carey, J David

    2015-10-14

    Advances in lightweight, flexible, and conformal electronic devices depend on materials that exhibit high electrical conductivity coupled with high mechanical strength. Defect-free graphene is one such material that satisfies both these requirements and which offers a range of attractive and tunable electrical, optoelectronic, and plasmonic characteristics for devices that operate at microwave, terahertz, infrared, or optical frequencies. Essential to the future success of such devices is therefore the ability to control the frequency-dependent conductivity of graphene. Looking to accelerate the development of high-frequency applications of graphene, here we demonstrate how readily accessible and processable organic and organometallic molecules can efficiently dope graphene to carrier densities in excess of 10(13) cm(-2) with conductivities at gigahertz frequencies in excess of 60 mS. In using the molecule 3,6-difluoro-2,5,7,7,8,8-hexacyanoquinodimethane (F2-HCNQ), a high charge transfer (CT) of 0.5 electrons per adsorbed molecule is calculated, resulting in p-type doping of graphene. n-Type doping is achieved using cobaltocene and the sulfur-containing molecule tetrathiafulvalene (TTF) with a CT of 0.41 and 0.24 electrons donated per adsorbed molecule, respectively. Efficient CT is associated with the interaction between the π electrons present in the molecule and in graphene. Calculation of the high-frequency conductivity shows dispersion-less behavior of the real component of the conductivity over a wide range of gigahertz frequencies. Potential high-frequency applications in graphene antennas and communications that can exploit these properties and the broader impacts of using molecular doping to modify functional materials that possess a low-energy Dirac cone are also discussed.

  17. Method of measuring thermal conductivity of high performance insulation

    NASA Technical Reports Server (NTRS)

    Hyde, E. H.; Russell, L. D.

    1968-01-01

    Method accurately measures the thermal conductivity of high-performance sheet insulation as a discrete function of temperature. It permits measurements to be made at temperature drops of approximately 10 degrees F across the insulation and ensures measurement accuracy by minimizing longitudinal heat losses in the system.

  18. Electronically conductive ceramics for high temperature oxidizing environments

    DOEpatents

    Kucera, Gene H.; Smith, James L.; Sim, James W.

    1986-01-01

    A high temperature, ceramic composition having electronic conductivity as measured by resistivity below about 500 ohm-cm, chemical stability particularly with respect to cathode conditions in a molten carbonate fuel cell, and composed of an alkali metal, transition metal oxide containing a dopant metal in the crystalline structure to replace a portion of the alkali metal or transition metal.

  19. Electronically conductive ceramics for high temperature oxidizing environments

    DOEpatents

    Kucera, G.H.; Smith, J.L.; Sim, J.W.

    1983-11-10

    This invention pertains to a high temperature, ceramic composition having electronic conductivity as measured by resistivity below about 500 ohm-cm, chemical stability particularly with respect to cathode conditions in a molten carbonate fuel cell, and composed of an alkali metal, transition metal oxide containing a dopant metal in the crystalline structure to replace a portion of the alkali metal or transition metal.

  20. Silver Nanowire Networks as Flexible, Transparent, Conducting Films: Extremely High DC to Optical Conductivity Ratios.

    PubMed

    De, Sukanta; Higgins, Thomas M; Lyons, Philip E; Doherty, Evelyn M; Nirmalraj, Peter N; Blau, Werner J; Boland, John J; Coleman, Jonathan N

    2009-07-28

    We have used aqueous dispersions of silver nanowires to prepare thin, flexible, transparent, conducting films. The nanowires are of length and diameter close to 6.5 μm and 85 nm, respectively. At low thickness, the films consist of networks but appear to become bulk-like for mean film thicknesses above ∼160 nm. These films can be very transparent with optical transmittance reaching as high as 92% for low thickness. The transmittance (550 nm) decreases with increasing thickness, consistent with an optical conductivity of 6472 S/m. The films are also very uniform; the transmittance varies spatially by typically <2%. The sheet resistance decreases with increasing thickness, falling below 1 Ω/◻ for thicknesses above 300 nm. The DC conductivity increases from 2 × 10(5) S/m for very thin films before saturating at 5 × 10(6) S/m for thicker films. Similarly, the ratio of DC to optical conductivity increases with increasing thickness from 25 for the thinnest films, saturating at ∼500 for thicknesses above ∼160 nm. We believe this is the highest conductivity ratio ever observed for nanostructured films and is matched only by doped metal oxide films. These nanowire films are electromechanically very robust, with all but the thinnest films showing no change in sheet resistance when flexed over >1000 cycles. Such results make these films ideal as replacements for indium tin oxide as transparent electrodes. We have prepared films with optical transmittance and sheet resistance of 85% and 13 Ω/◻, respectively. This is very close to that displayed by commercially available indium tin oxide.

  1. Metallic behaviour of acid doped highly conductive polymers.

    PubMed

    Massonnet, Nicolas; Carella, Alexandre; de Geyer, Arnaud; Faure-Vincent, Jérôme; Simonato, Jean-Pierre

    2015-01-01

    Conductive polymers such as poly(3,4-ethylenedioxythiophene) (PEDOT) are used in a wide range of applications as transparent electrodes, hole injecting layers or thermoelectric materials for room-temperature applications. However, progress is needed to enhance the electrical conductivities of the materials and to provide understanding about their structure-transport relationships. This work presents the synthesis of highly conductive PEDOT-based polymers using iron(iii) trifluoromethanesulfonate as oxidant for the first time. The metallic behaviour of the polymer is revealed by conductivity monitoring from 3 to 300 K. The electrical conductivity is further improved (to 2273 S cm(-1)) using acids, leading to a positive temperature coefficient of resistivity at an unprecedented 45.5% oxidation state. X-ray photoemission spectroscopy (XPS) and time of flight-secondary ion mass spectrometry (ToF-SIMS) analyses demonstrate a complete replacement of the trifluoromethanesulfonate anions by hydrogen sulphate counter ions. This substitution results in an increased concentration of charge carriers (measured in organic electrochemical transistors) along with an enhancement of the mean size of crystalline domains, highlighted by small and wide angle X-ray scattering (SAXS/WAXS), which explains the 80% increase of electrical conductivity.

  2. High ion conducting polymer nanocomposite electrolytes using hybrid nanofillers.

    PubMed

    Tang, Changyu; Hackenberg, Ken; Fu, Qiang; Ajayan, Pulickel M; Ardebili, Haleh

    2012-03-14

    There is a growing shift from liquid electrolytes toward solid polymer electrolytes, in energy storage devices, due to the many advantages of the latter such as enhanced safety, flexibility, and manufacturability. The main issue with polymer electrolytes is their lower ionic conductivity compared to that of liquid electrolytes. Nanoscale fillers such as silica and alumina nanoparticles are known to enhance the ionic conductivity of polymer electrolytes. Although carbon nanotubes have been used as fillers for polymers in various applications, they have not yet been used in polymer electrolytes as they are conductive and can pose the risk of electrical shorting. In this study, we show that nanotubes can be packaged within insulating clay layers to form effective 3D nanofillers. We show that such hybrid nanofillers increase the lithium ion conductivity of PEO electrolyte by almost 2 orders of magnitude. Furthermore, significant improvement in mechanical properties were observed where only 5 wt % addition of the filler led to 160% increase in the tensile strength of the polymer. This new approach of embedding conducting-insulating hybrid nanofillers could lead to the development of a new generation of polymer nanocomposite electrolytes with high ion conductivity and improved mechanical properties. © 2012 American Chemical Society

  3. Ultralow thermal conductivity of multilayers with highly dissimilar Debye temperatures.

    PubMed

    Dechaumphai, Edward; Lu, Dylan; Kan, Jimmy J; Moon, Jaeyun; Fullerton, Eric E; Liu, Zhaowei; Chen, Renkun

    2014-05-14

    Thermal transport in multilayers (MLs) has attracted significant interest and shows promising applications. Unlike their single-component counterparts, MLs exhibit a thermal conductivity that can be effectively engineered by both the number density of the layers and the interfacial thermal resistance between layers, with the latter being highly tunable via the contrast of acoustic properties of each layer. In this work, we experimentally demonstrated an ultralow thermal conductivity of 0.33 ± 0.04 W m(-1) K(-1) at room temperature in MLs made of Au and Si with a high interfacial density of ∼0.2 interface nm(-1). The measured thermal conductivity is significantly lower than the amorphous limit of either Si or Au and is also much lower than previously measured MLs with a similar interfacial density. With a Debye temperature ratio of ∼3.9 for Au and Si, the Au/Si MLs represent the highest mismatched system in inorganic MLs measured to date. In addition, we explore the prior theoretical prediction that full phonon dispersion could better model the interfacial thermal resistance involving materials with low Debye temperatures. Our results demonstrate that MLs with highly dissimilar Debye temperatures represent a rational approach to achieve ultralow thermal conductivity in inorganic materials and can also serve as a platform for investigating interfacial thermal transport.

  4. Thermal conductance of metal-diamond interfaces at high pressure.

    PubMed

    Hohensee, Gregory T; Wilson, R B; Cahill, David G

    2015-03-06

    The thermal conductance of interfaces between metals and diamond, which has a comparatively high Debye temperature, is often greater than can be accounted for by two-phonon processes. The high pressures achievable in a diamond anvil cell (DAC) can significantly extend the metal phonon density of states to higher frequencies, and can also suppress extrinsic effects by greatly stiffening interface bonding. Here we report time-domain thermoreflectance measurements of metal-diamond interface thermal conductance up to 50 GPa in the DAC for Pb, Au0.95Pd0.05, Pt and Al films deposited on type 1A natural [100] and type 2A synthetic [110] diamond anvils. In all cases, the thermal conductances increase weakly or saturate to similar values at high pressure. Our results suggest that anharmonic conductance at metal-diamond interfaces is controlled by partial transmission processes, where a diamond phonon that inelastically scatters at the interface absorbs or emits a metal phonon.

  5. Observation of highly decoupled conductivity in protic ionic conductors.

    PubMed

    Wojnarowska, Zaneta; Wang, Yangyang; Paluch, Krzysztof J; Sokolov, Alexei P; Paluch, Marian

    2014-05-21

    Ionic liquids (ILs) are key materials for the development of a wide range of emerging technologies. Protic ionic liquids, an important class of ILs, have long been envisioned as promising anhydrous electrolytes for fuel cells. It is well known that in comparison to all other cations, protons exhibit abnormally high conductivity in water. Such superprotonic dynamics was expected in protic ionic conductors as well. However, many years of extensive studies led to the disappointing conclusion that this is not the case and most protic ionic liquids display subionic behavior. Therefore, the relatively low conductivity seems to be the main obstacle for the application of protic ionic liquids in fuel cells. Using dielectric spectroscopy, herein we report the observation of highly decoupled conductivity in a newly synthesized protic ionic conductor. We show that its proton transport is strongly decoupled from the structural relaxation, in terms of both temperature dependence and characteristic rates. This finding offers a fresh look on the charge transport mechanism in PILs and also provides new ideas for design of anhydrous materials with exceptionally high proton conductivity.

  6. Conducting polymer nanowire arrays for high performance supercapacitors.

    PubMed

    Wang, Kai; Wu, Haiping; Meng, Yuena; Wei, Zhixiang

    2014-01-15

    This Review provides a brief summary of the most recent research developments in the fabrication and application of one-dimensional ordered conducting polymers nanostructure (especially nanowire arrays) and their composites as electrodes for supercapacitors. By controlling the nucleation and growth process of polymerization, aligned conducting polymer nanowire arrays and their composites with nano-carbon materials can be prepared by employing in situ chemical polymerization or electrochemical polymerization without a template. This kind of nanostructure (such as polypyrrole and polyaniline nanowire arrays) possesses high capacitance, superior rate capability ascribed to large electrochemical surface, and an optimal ion diffusion path in the ordered nanowire structure, which is proved to be an ideal electrode material for high performance supercapacitors. Furthermore, flexible, micro-scale, threadlike, and multifunctional supercapacitors are introduced based on conducting polyaniline nanowire arrays and their composites. These prototypes of supercapacitors utilize the high flexibility, good processability, and large capacitance of conducting polymers, which efficiently extend the usage of supercapacitors in various situations, and even for a complicated integration system of different electronic devices.

  7. Thermal conductance of metal–diamond interfaces at high pressure

    SciTech Connect

    Hohensee, Gregory T.; Wilson, R. B.; Cahill, David G.

    2015-03-06

    The thermal conductance of interfaces between metals and diamond, which has a comparatively high Debye temperature, is often greater than can be accounted for by two phonon-processes. The high pressures achievable in a diamond anvil cell can significantly extend the metal phonon density of states to higher frequencies, and can also suppress extrinsic effects by greatly stiffening interface bonding. Here we report time-domain thermoreflectance measurements of metal-diamond interface thermal conductance up to 50 GPa in the DAC for Pb, Au0.95Pd0.05, Pt, and Al films deposited on Type 1A natural [100] and Type 2A synthetic [110] diamond anvils. In all cases, the thermal conductances increase weakly or saturate to similar values at high pressure. Lastly, our results suggest that anharmonic conductance at metal-diamond interfaces is controlled by partial transmission processes, where a diamond phonon that inelastically scatters at the interface absorbs or emits a metal phonon.

  8. Thermal conductance of metal–diamond interfaces at high pressure

    DOE PAGES

    Hohensee, Gregory T.; Wilson, R. B.; Cahill, David G.

    2015-03-06

    The thermal conductance of interfaces between metals and diamond, which has a comparatively high Debye temperature, is often greater than can be accounted for by two phonon-processes. The high pressures achievable in a diamond anvil cell can significantly extend the metal phonon density of states to higher frequencies, and can also suppress extrinsic effects by greatly stiffening interface bonding. Here we report time-domain thermoreflectance measurements of metal-diamond interface thermal conductance up to 50 GPa in the DAC for Pb, Au0.95Pd0.05, Pt, and Al films deposited on Type 1A natural [100] and Type 2A synthetic [110] diamond anvils. In all cases,more » the thermal conductances increase weakly or saturate to similar values at high pressure. Lastly, our results suggest that anharmonic conductance at metal-diamond interfaces is controlled by partial transmission processes, where a diamond phonon that inelastically scatters at the interface absorbs or emits a metal phonon.« less

  9. Highly thermally conductive and mechanically strong graphene fibers

    NASA Astrophysics Data System (ADS)

    Xin, Guoqing; Yao, Tiankai; Sun, Hongtao; Scott, Spencer Michael; Shao, Dali; Wang, Gongkai; Lian, Jie

    2015-09-01

    Graphene, a single layer of carbon atoms bonded in a hexagonal lattice, is the thinnest, strongest, and stiffest known material and an excellent conductor of heat and electricity. However, these superior properties have yet to be realized for graphene-derived macroscopic structures such as graphene fibers. We report the fabrication of graphene fibers with high thermal and electrical conductivity and enhanced mechanical strength. The inner fiber structure consists of large-sized graphene sheets forming a highly ordered arrangement intercalated with small-sized graphene sheets filling the space and microvoids. The graphene fibers exhibit a submicrometer crystallite domain size through high-temperature treatment, achieving an enhanced thermal conductivity up to 1290 watts per meter per kelvin. The tensile strength of the graphene fiber reaches 1080 megapascals.

  10. Highly purified collagen coating enhances tissue adherence and integration properties of monofilament polypropylene meshes.

    PubMed

    Siniscalchi, Rodrigo Teixeira; Melo, Marli; Palma, Paulo César Rodrigues; Dal Fabbro, Inácio Maria; Vidal, Benedicto de Campos; Riccetto, Cassio Luiz Zanettini

    2013-10-01

    Complications related to tissue integration of polypropylene implants used in the treatment of pelvic organ prolapse are relatively prevalent. Collagen, a biocompatible, less immunogenic material with modulating properties on the inflammatory process, may improve polypropylene integration. The objective was to study biomechanical and histological effects of monofilament polypropylene mesh coated with purified collagen gel. Forty rats were implanted with two fragments of polypropylene mesh in their abdominal walls (one on each side of the linea alba). One of the fragments had a collagen gel coating (group I) while the other one did not (group II). The animals were euthanized at 7, 14, 90, and 180 days after implantation and their abdominal walls were excised for analysis. The biomechanical study showed that mesh adherence to neighboring tissue increased significantly in group II (p < 0.05). Acute (p < 0.001) and chronic (p = 0.004) inflammatory responses as well as granulation tissue formation (p = 0.001) were less intense in group II at 7 and 14 days. Granulomatous inflammation and foreign body reaction was less significant at 7 days in group II (p = 0.029 and p < 0.001). The birefringence analysis showed higher mean brightness density in the late phase of implantation in group II meshes (p = 0.000). Polypropylene mesh coated with purified collagen gel increases adherence to tissue, promotes a less intense and lasting inflammatory response and triggers a greater organization and packing arrangement of collagen fibers in the late phase of implantation.

  11. Fabrication of graphene films with high transparent conducting characteristics.

    PubMed

    Ma, Xiying; Zhang, Hao

    2013-10-23

    We present a study on the transparent conducting characteristics of graphene-based films prepared by means of rapid chemical vapor deposition. The graphene films were grown on quartz slides with a CH4/Ar mixed gas under a constant flow at 950°C and then annealed at 1,000°C. It was found that the graphene films present excellent electrical conductivity with high transparency. The conductivity is up to 1,240 S/cm, the sheet resistance is lower than 1 kΩ/sq, and the transparency is well over 85% in the visible wavelength range of 400 to 800 nm, showing that the graphene films have very low resistivity and superior transparency and completely satisfy the need for transparent conductors. These properties can be used in many applications, such as transparent conductor films for touch panels. PACS: 61.48.+c, 78.67.Pt, 68.37.Hk, 68.65.Ac.

  12. Fabrication of graphene films with high transparent conducting characteristics

    PubMed Central

    2013-01-01

    We present a study on the transparent conducting characteristics of graphene-based films prepared by means of rapid chemical vapor deposition. The graphene films were grown on quartz slides with a CH4/Ar mixed gas under a constant flow at 950°C and then annealed at 1,000°C. It was found that the graphene films present excellent electrical conductivity with high transparency. The conductivity is up to 1,240 S/cm, the sheet resistance is lower than 1 kΩ/sq, and the transparency is well over 85% in the visible wavelength range of 400 to 800 nm, showing that the graphene films have very low resistivity and superior transparency and completely satisfy the need for transparent conductors. These properties can be used in many applications, such as transparent conductor films for touch panels. PACS 61.48.+c, 78.67.Pt, 68.37.Hk, 68.65.Ac PMID:24153052

  13. Electrical conductivity of rigid polyurethane foam at high temperature

    NASA Astrophysics Data System (ADS)

    Johnson, R. T., Jr.

    1982-08-01

    The electrical conductivity of rigid polyurethane foam, used for electronic encapsulation, was measured during thermal decomposition to 3400 C. At higher temperatures the conductance continues to increase. With pressure loaded electrical leads, sample softening results in eventual contact between electrodes which produces electrical shorting. Air and nitrogen environments show no significant dependence of the conductivity on the atmosphere over the temperature range. The insulating characteristics of polyurethane foam below approx. 2700 C are similar to those for silicone based materials used for electronic case housings and are better than those for phenolics. At higher temperatures (greater than or equal to 2700 C) the phenolics appear to be better insulators to approx. 5000 C and the silicones to approx. 6000 C. It is concluded that the Sylgard 184/GMB encapsulant is a significantly better insulator at high temperature than the rigid polyurethane foam.

  14. Axisymmetric instabilities in electrospinning of highly conducting, viscoelastic polymer solutions

    NASA Astrophysics Data System (ADS)

    Carroll, Colman P.; Joo, Yong Lak

    2009-10-01

    In this paper the axisymmetric instabilities observed during the electrospinning of highly electrically conducting, viscoelastic poly(ethylene oxide) (PEO)/water solutions are investigated. In our theoretical study, a linear stability analysis is coupled with a model for the stable electrospun jet. The combined model is used to calculate the expected bead growth rate and wave number for given electrospinning conditions. In the experimental section of the study, PEO/water solutions are electrospun and the formation of axisymmetric beads is captured using high-speed photography. Experimental values for the bead growth rate and wave number are extracted and compared with the model predictions. An energy analysis is then carried out on the stability results to investigate the mechanism of instability via the coupling between base flow and perturbation. The analysis reveals that the unstable axisymmetric mode for electrically driven, highly conducting jets is not a capillary mode, but is mainly driven by electrical forces due to the interaction of charges on the jet. We note that this axisymmetric, conducting mode often exhibits a growth rate too small to be observed during electrospinning. However, both our experiments and stability analysis demonstrate that the axisymmetric instability with a high growth rate can be seen in practice when the electrical force is effectively coupled with viscoelastic forces.

  15. Developing a High Thermal Conductivity Fuel with Silicon Carbide Additives

    SciTech Connect

    baney, Ronald; Tulenko, James

    2012-11-20

    The objective of this research is to increase the thermal conductivity of uranium oxide (UO{sub 2}) without significantly impacting its neutronic properties. The concept is to incorporate another high thermal conductivity material, silicon carbide (SiC), in the form of whiskers or from nanoparticles of SiC and a SiC polymeric precursor into UO{sub 2}. This is expected to form a percolation pathway lattice for conductive heat transfer out of the fuel pellet. The thermal conductivity of SiC would control the overall fuel pellet thermal conductivity. The challenge is to show the effectiveness of a low temperature sintering process, because of a UO{sub 2}-SiC reaction at 1,377°C, a temperature far below the normal sintering temperature. Researchers will study three strategies to overcome the processing difficulties associated with pore clogging and the chemical reaction of SiC and UO{sub 2} at temperatures above 1,300°C:

  16. The effect of depressive symptoms and CD4 count on adherence to highly active antiretroviral therapy in sub-Saharan Africa.

    PubMed

    Memiah, Peter; Shumba, Constance; Etienne-Mesubi, Martine; Agbor, Solomon; Hossain, Mian B; Komba, Patience; Niyang, Mercy; Biadgilign, Sibhatu

    2014-01-01

    Studies have identified several programmatic and nonprogrammatic indicators that affect adherence to highly active antiretroviral therapy (HAART). Depression has been shown to impact adherence to HAART. This cross-sectional analysis of data collected from Nigeria, Uganda, Zambia, and Tanzania in 2008 examined the relationship between levels of depressive symptoms, clinical progression, and adherence to HAART. A multinational, multicenter, observational, retrospective cross-sectional evaluation of a population of focus comprised randomly selected patients on HAART. The dependent variable was adherence to HAART. The primary variable of interest to be assessed was patients' level of depressive symptom score. A multivariable logistic regression model was used to examine the relationship between explanatory variables and adherence to HAART. A total of 2344 patients were recruited for adherence survey. About 70% of the study sample reported having some level of depression. Logistic regression results show that patients who reported, respectively, low, moderate, and high levels of depressive symptoms are 35% (P < .001), 56% (P < .001), and 64% (P < .001) less likely to adhere to HAART than those who reported having no depressive symptoms. At multivariate analysis, adherence to HAART was independently associated with the levels of depressive symptoms, older age, CD4 count >200 cells/mm3, Truvada (tenofovir [TDF]/emtricitabine [FTC])-based regimens, good knowledge about HAART, and longer period on therapy. These results indicate that mental health and clinical parameters are significant factors in determining patients' adherence to their HAART, which need to be more aggressively addressed as a critical component of care and treatment support.

  17. Highly thermally conductive papers with percolative layered boron nitride nanosheets.

    PubMed

    Zhu, Hongli; Li, Yuanyuan; Fang, Zhiqiang; Xu, Jiajun; Cao, Fangyu; Wan, Jiayu; Preston, Colin; Yang, Bao; Hu, Liangbing

    2014-04-22

    In this work, we report a dielectric nanocomposite paper with layered boron nitride (BN) nanosheets wired by one-dimensional (1D) nanofibrillated cellulose (NFC) that has superior thermal and mechanical properties. These nanocomposite papers are fabricated from a filtration of BN and NFC suspensions, in which NFC is used as a stabilizer to stabilize BN nanosheets. In these nanocomposite papers, two-dimensional (2D) nanosheets form a thermally conductive network, while 1D NFC provides mechanical strength. A high thermal conductivity has been achieved along the BN paper surface (up to 145.7 W/m K for 50 wt % of BN), which is an order of magnitude higher than that in randomly distributed BN nanosheet composites and is even comparable to the thermal conductivity of aluminum alloys. Such a high thermal conductivity is mainly attributed to the structural alignment within the BN nanosheet papers; the effects of the interfacial thermal contact resistance are minimized by the fact that the heat transfer is in the direction parallel to the interface between BN nanosheets and that a large contact area occurs between BN nanosheets.

  18. Interior Regularity Estimates in High Conductivity Homogenization and Application

    NASA Astrophysics Data System (ADS)

    Briane, Marc; Capdeboscq, Yves; Nguyen, Luc

    2013-01-01

    In this paper, uniform pointwise regularity estimates for the solutions of conductivity equations are obtained in a unit conductivity medium reinforced by an ɛ-periodic lattice of highly conducting thin rods. The estimates are derived only at a distance ɛ 1+ τ (for some τ > 0) away from the fibres. This distance constraint is rather sharp since the gradients of the solutions are shown to be unbounded locally in L p as soon as p > 2. One key ingredient is the derivation in dimension two of regularity estimates to the solutions of the equations deduced from a Fourier series expansion with respect to the fibres' direction, and weighted by the high-contrast conductivity. The dependence on powers of ɛ of these two-dimensional estimates is shown to be sharp. The initial motivation for this work comes from imaging, and enhanced resolution phenomena observed experimentally in the presence of micro-structures (L erosey et al., Science 315:1120-1124, 2007). We use these regularity estimates to characterize the signature of low volume fraction heterogeneities in the fibred reinforced medium, assuming that the heterogeneities stay at a distance ɛ 1+ τ away from the fibres.

  19. The role of family caregivers in HIV medication adherence.

    PubMed

    Beals, K P; Wight, R G; Aneshensel, C S; Murphy, D A; Miller-Martinez, D

    2006-08-01

    This study examines the role that mid-life and older wives and mothers play in promoting medication adherence among their HIV-infected husbands or adult sons who require daily living assistance. Interviews were conducted with 112 caregiving dyads, with caregivers reporting on their own behaviours and attitudes towards medications, and care-recipients (persons living with HIV [PLH]) providing information about their own adherence practices. By examining how caregiver characteristics, behaviours, and attitudes may influence PLH adherence it is explicitly recognized that caregivers and PLH are linked within a caregiving dyad. Findings indicate that caregivers often remind PLH to take medications, but these reminders are not significantly associated with adherence. Caregivers also report strong attitudes about medication hassles, concerns over treatment failure and general concerns about adherence. Controlling for background characteristics, high perceived adherence hassles on the part of the caregiver were associated with low PLH adherence, providing evidence of shared influence within the caregiving dyad. Adherence interventions may maximize their effectiveness if they consider the role of the family caregiver because these data suggest that caregiver attitudes are linked with PLH adherence behaviours.

  20. Association between adherence to dietary recommendations and high-sensitivity C-reactive protein level in type 1 diabetes.

    PubMed

    Ahola, Aila J; Saraheimo, Markku; Freese, Riitta; Forsblom, Carol; Mäkimattila, Sari; Groop, Per-Henrik

    2017-04-01

    Inflammation plays an important role in the pathogenesis of cardiovascular diseases. Diet, as a modifiable risk factor, may in turn impact systemic inflammation. We therefore assessed whether adherence to the dietary recommendations is associated with high-sensitivity C-reactive protein (hs-CRP) concentrations in type 1 diabetes. Cross-sectional data from 677 FinnDiane study participants (48% men, mean±standard deviation age 46±13years) were included. Dietary intake was assessed with a self-administered questionnaire. A diet score, with higher values denoting better adherence to the recommendations, was calculated. Serum hs-CRP concentration was measured, and individuals with hs-CRP <1.0mg/l, and hs-CRP >3.0 but ≤10.0mg/l were compared. Men and women with high hs-CRP had higher BMI, waist circumference, and triglyceride concentration, but lower HDL-cholesterol concentration. Adjusted for BMI, mean diet score was higher in the low hs-CRP group, both in men (10.8±3.6 vs. 9.9±3.8, p=0.023) and women (12.7±3.4 vs. 11.6±3.5, p=0.021). After further adjustments with potential confounding factors, the difference remained significant only in men. A diet that more closely adheres to the dietary recommendations is associated with lower hs-CRP in men. A prudent diet may help reduce systemic inflammation in type 1 diabetes. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Highly transparent, conductive, flexible resin films embedded with silver nanowires.

    PubMed

    Jiang, Yaqiu; Xi, Jun; Wu, Zhaoxin; Dong, Hua; Zhao, Zhixu; Jiao, Bo; Hou, Xun

    2015-05-05

    In this article, a low sheet resistance and highly transparent silver nanowire (AgNW) resin composite film was demonstrated, which was prepared by a simple and efficacious two-step spin-coating method. By burying the AgNWs below the surface of the transparent resin matrix which was cured at 150 °C in air, we achieved a uniform, highly transparent, conductive, flexible film. Compared to the reported transparent electrodes, this composite transparent and conductive film showed 10 Ω/□ sheet resistance and nearly 90% mean optical transmittance over the UV-visible range simultaneously. Undergoing hundreds of cycles of tensile and compression folding, the composite film slightly increased its sheet resistance by less than 5%, displaying good electromechanical flexibility. These characteristics of the composite AgNW-resin films were expected to be used in applications of flexible optoelectronics.

  2. Fabrication of highly conductive carbon nanotube fibers for electrical application

    NASA Astrophysics Data System (ADS)

    Guo, Fengmei; Li, Can; Wei, Jinquan; Xu, Ruiqiao; Zhang, Zelin; Cui, Xian; Wang, Kunlin; Wu, Dehai

    2015-09-01

    Carbon nanotubes (CNTs) have great potential for use as electrical wires because of their outstanding electrical and mechanical properties. Here, we fabricate lightweight CNT fibers with electrical conductivity as high as that of stainless steel from macroscopic CNT films by drawing them through diamond wire-drawing dies. The entangled CNT bundles are straightened by suffering tension, which improves the alignment of the fibers. The loose fibers are squeezed by the diamond wire-drawing dies, which reduces the intertube space and contact resistance. The CNT fibers prepared by drawing have an electrical conductivity as high as 1.6 × 106 s m-1. The fibers are very stable when kept in the air and under cyclic tensile test. A prototype of CNT motor is demonstrated by replacing the copper wires with the CNT fibers.

  3. Powder-Derived High-Conductivity Coatings for Copper Alloys

    NASA Technical Reports Server (NTRS)

    Thomas-Ogbuji, Linus U.

    2003-01-01

    Makers of high-thermal-flux engines prefer copper alloys as combustion chamber liners, owing to a need to maximize heat dissipation. Since engine environments are strongly oxidizing in nature and copper alloys generally have inadequate resistance to oxidation, the liners need coatings for thermal and environmental protection; however, coatings must be chosen with great care in order to avoid significant impairment of thermal conductivity. Powder-derived chromia- and alumina- forming alloys are being studied under NASA's programs for advanced reusable launch vehicles to succeed the space shuttle fleet. NiCrAlY and Cu-Cr compositions optimized for high thermal conductivity have been tested for static and cyclic oxidation, and for susceptibility to blanching - a mode of degradation arising from oxidation-reduction cycling. The results indicate that the decision to coat the liners or not, and which coating/composition to use, depends strongly on the specific oxidative degradation mode that prevails under service conditions.

  4. Roles of family dynamics on adherence to highly active antiretroviral therapy among people living with HIV/AIDS at a tertiary hospital in Osogbo, south-west Nigeria.

    PubMed

    Afolabi, B A; Afolabi, M O; Afolabi, A A; Odewale, M A; Olowookere, S A

    2013-12-01

    Adherence to highly active antiretroviral therapy (HAART) has been proven to be the only effective treatment for HIV/AIDS worldwide. Good adherence to HAART might require good family support. To determine the family dynamics and social support of people living with HIV/AIDS (PLWHA) and its roles on HAART adherence at an ARV treatment clinic in Osogbo, Nigeria. Descriptive cross-sectional study. Consenting PLWHA on HAART were interviewed using pre-tested semistructured questionnaire incorporating Perceived Social Support- Family Scale and Family APGAR. HAART adherence was measured using patient self report. A total of 379 PLWHA were interviewed. Their mean age was 40.8 (SD=9.9) years. Most (60.7%) were females. More than half (55.7%) were currently married and the majority (72.1%) had secondary education and were Yoruba (86.3%). Most respondents (95.5%) were adherent to HAART. Over 90% were satisfied with support received from their family while 82.3% were treated like other family members. Most attributed their HAART adherence to the care and support received from their family. Most PLWHA had good social support and were adherent to HAART.

  5. Efficacy of interventions in improving highly active antiretroviral therapy adherence and HIV-1 RNA viral load. A meta-analytic review of randomized controlled trials.

    PubMed

    Simoni, Jane M; Pearson, Cynthia R; Pantalone, David W; Marks, Gary; Crepaz, Nicole

    2006-12-01

    Adherence to highly active antiretroviral therapy (HAART) is generally suboptimal, limiting the effectiveness of HAART. This meta-analytic review examined whether behavioral interventions addressing HAART adherence are successful in increasing the likelihood of a patient attaining 95% adherence or an undetectable HIV-1 RNA viral load (VL). We searched electronic databases from January 1996 to September 2005, consulted with experts in the field, and hand searched reference sections from relevant articles. Nineteen studies (with a total of 1839 participants) met the selection criteria of describing a randomized controlled trial among adults evaluating a behavioral intervention with HAART adherence or VL as an outcome. Random-effects models indicated that across studies, participants in the intervention arm were more likely than those in the control arm to achieve 95% adherence (odds ratio [OR] = 1.50, 95% confidence interval [CI]: 1.16 to 1.94); the effect was nearly significant for undetectable VL (OR = 1.25; 95% CI: 0.99 to 1.59). The intervention effect for 95% adherence was significantly stronger in studies that used recall periods of 2 weeks or 1 month (vs. adherence intervention strategies were shown to be successful, but more research is needed to identify the most efficacious intervention components and the best methods for implementing them in real-world settings with limited resources.

  6. Method for producing highly conformal transparent conducting oxides

    SciTech Connect

    Elam, Jeffrey W.; Mane, Anil U.

    2016-07-26

    A method for forming a transparent conducting oxide product layer. The method includes use of precursors, such as tetrakis-(dimethylamino) tin and trimethyl indium, and selected use of dopants, such as SnO and ZnO for obtaining desired optical, electrical and structural properties for a highly conformal layer coating on a substrate. Ozone was also input as a reactive gas which enabled rapid production of the desired product layer.

  7. Recent Improvements in High-Frequency Eddy Current Conductivity Spectroscopy

    NASA Astrophysics Data System (ADS)

    Abu-Nabah, Bassam A.; Nagy, Peter B.

    2008-02-01

    Due to its frequency-dependent penetration depth, eddy current measurements are capable of mapping near-surface residual stress profiles based on the so-called piezoresistivity effect, i.e., the stress-dependence of electric conductivity. To capture the peak compressive residual stress in moderately shot-peened (Almen 4-8A) nickel-base superalloys, the eddy current inspection frequency has to go as high as 50-80 MHz. Recently, we have reported the development of a new high-frequency eddy current conductivity measuring system that offers an extended inspection frequency range up to 80 MHz. Unfortunately, spurious self- and stray-capacitance effects render the complex coil impedance variation with lift-off more nonlinear as the frequency increases, which makes it difficult to achieve accurate apparent eddy current conductivity (AECC) measurements with the standard four-point linear interpolation method beyond 25 MHz. In this paper, we will demonstrate that reducing the coil size reduces its sensitivity to capacitive lift-off variations, which is just the opposite of the better known inductive lift-off effect. Although reducing the coil size also reduces its absolute electric impedance and relative sensitivity to conductivity variations, a smaller coil still yields better overall performance for residual stress assessment. In addition, we will demonstrate the benefits of a semi-quadratic interpolation scheme that, together with the reduced lift-off sensitivity of the smaller probe coil, minimizes and in some cases completely eliminates the sensitivity of AECC measurements to lift-off uncertainties. These modifications allow us to do much more robust measurements up to as high as 80-100 MHz with the required high relative accuracy of +/-0.1%.

  8. Hierarchical nanostructured conducting polymer hydrogel with high electrochemical activity

    PubMed Central

    Pan, Lijia; Yu, Guihua; Zhai, Dongyuan; Lee, Hye Ryoung; Zhao, Wenting; Liu, Nian; Wang, Huiliang; Tee, Benjamin C.-K.; Shi, Yi; Cui, Yi; Bao, Zhenan

    2012-01-01

    Conducting polymer hydrogels represent a unique class of materials that synergizes the advantageous features of hydrogels and organic conductors and have been used in many applications such as bioelectronics and energy storage devices. They are often synthesized by polymerizing conductive polymer monomer within a nonconducting hydrogel matrix, resulting in deterioration of their electrical properties. Here, we report a scalable and versatile synthesis of multifunctional polyaniline (PAni) hydrogel with excellent electronic conductivity and electrochemical properties. With high surface area and three-dimensional porous nanostructures, the PAni hydrogels demonstrated potential as high-performance supercapacitor electrodes with high specific capacitance (∼480 F·g-1), unprecedented rate capability, and cycling stability (∼83% capacitance retention after 10,000 cycles). The PAni hydrogels can also function as the active component of glucose oxidase sensors with fast response time (∼0.3 s) and superior sensitivity (∼16.7 μA·mM-1). The scalable synthesis and excellent electrode performance of the PAni hydrogel make it an attractive candidate for bioelectronics and future-generation energy storage electrodes. PMID:22645374

  9. A Novel Methodology to Synthesize Highly Conductive Anion Exchange Membranes

    NASA Astrophysics Data System (ADS)

    He, Yubin; Pan, Jiefeng; Wu, Liang; Zhu, Yuan; Ge, Xiaolin; Ran, Jin; Yang, Zhengjin; Xu, Tongwen

    2015-08-01

    Alkaline polyelectrolyte fuel cell now receives growing attention as a promising candidate to serve as the next generation energy-generating device by enabling the use of non-precious metal catalysts (silver, cobalt, nickel et al.). However, the development and application of alkaline polyelectrolyte fuel cell is still blocked by the poor hydroxide conductivity of anion exchange membranes. In order to solve this problem, we demonstrate a methodology for the preparation of highly OH- conductive anion exchange polyelectrolytes with good alkaline tolerance and excellent dimensional stability. Polymer backbones were grafted with flexible aliphatic chains containing two or three quaternized ammonium groups. The highly flexible and hydrophilic multi-functionalized side chains prefer to aggregate together to facilitate the formation of well-defined hydrophilic-hydrophobic microphase separation, which is crucial for the superior OH- conductivity of 69 mS/cm at room temperature. Besides, the as-prepared AEMs also exhibit excellent alkaline tolerance as well as improved dimensional stability due to their carefully designed polymer architecture, which provide new directions to pursue high performance AEMs and are promising to serve as a candidate for fuel cell technology.

  10. Switch on the high thermal conductivity of graphene paper.

    PubMed

    Xie, Yangsu; Yuan, Pengyu; Wang, Tianyu; Hashemi, Nastaran; Wang, Xinwei

    2016-10-14

    This work reports on the discovery of a high thermal conductivity (κ) switch-on phenomenon in high purity graphene paper (GP) when its temperature is reduced from room temperature down to 10 K. The κ after switch-on (1732 to 3013 W m(-1) K(-1)) is 4-8 times that before switch-on. The triggering temperature is 245-260 K. The switch-on behavior is attributed to the thermal expansion mismatch between pure graphene flakes and impurity-embedded flakes. This is confirmed by the switch behavior of the temperature coefficient of resistance. Before switch-on, the interactions between pure graphene flakes and surrounding impurity-embedded flakes efficiently suppress phonon transport in GP. After switch-on, the structure separation frees the pure graphene flakes from the impurity-embedded neighbors, leading to a several-fold κ increase. The measured κ before and after switch-on is consistent with the literature reported κ values of supported and suspended graphene. By conducting comparison studies with pyrolytic graphite, graphene oxide paper and partly reduced graphene paper, the whole physical picture is illustrated clearly. The thermal expansion induced switch-on is feasible only for high purity GP materials. This finding points out a novel way to switch on/off the thermal conductivity of graphene paper based on substrate-phonon scattering.

  11. Situational temptation for HIV medication adherence in high-risk youth.

    PubMed

    Macdonell, Karen E; Naar-King, Sylvie; Murphy, Debra A; Parsons, Jeffrey T; Huszti, Heather

    2011-01-01

    Abstract This study explored the role of situational temptation, a component of self-efficacy, in adolescent and young adult (ages 16-24) HIV medication adherence by assessing participants' perceptions of their temptation to miss medications in various situations (e.g., when medication causes physical side effects, when there is fear of disclosure of HIV status). Youth (n = 186; 83% African American) were participants in a multisite clinical trial examining the efficacy of a motivational intervention. Data were collected using computer-assisted personal interviewing. Youth believed the most tempting reasons or situations that might lead them to miss their HIV medications to be symptoms (if the medicine caused you to have other physical symptoms) and sick (if the medicine made you sick to your stomach or made you throw up or if it tasted bad), but these were not significantly associated with nonadherence. This suggests disconnection between youths' expectations of temptation and actual tempting situations associated with nonadherence. Situational temptations associated with nonadherence included lack of social support, needing a break from medications, and not seeing a need for medications. Interventions to improve adherence should consider perceptions of HIV medications, particularly the benefits of taking medications and expectations of physical symptoms. Interventionists and clinicians should consider situations that may tempt youth to miss doses of medication and help youth gain insight into these temptations. Emerging methods, such as Ecological Momentary Assessment (e.g., daily diaries, cell phone text messaging), may be useful in gaining insight into the day-to-day experience of youth living with HIV.

  12. Situational Temptation for HIV Medication Adherence in High-Risk Youth

    PubMed Central

    Naar-King, Sylvie; Murphy, Debra A.; Parsons, Jeffrey T.; Huszti, Heather

    2011-01-01

    Abstract This study explored the role of situational temptation, a component of self-efficacy, in adolescent and young adult (ages 16–24) HIV medication adherence by assessing participants' perceptions of their temptation to miss medications in various situations (e.g., when medication causes physical side effects, when there is fear of disclosure of HIV status). Youth (n = 186; 83% African American) were participants in a multisite clinical trial examining the efficacy of a motivational intervention. Data were collected using computer-assisted personal interviewing. Youth believed the most tempting reasons or situations that might lead them to miss their HIV medications to be symptoms (if the medicine caused you to have other physical symptoms) and sick (if the medicine made you sick to your stomach or made you throw up or if it tasted bad), but these were not significantly associated with nonadherence. This suggests disconnection between youths' expectations of temptation and actual tempting situations associated with nonadherence. Situational temptations associated with nonadherence included lack of social support, needing a break from medications, and not seeing a need for medications. Interventions to improve adherence should consider perceptions of HIV medications, particularly the benefits of taking medications and expectations of physical symptoms. Interventionists and clinicians should consider situations that may tempt youth to miss doses of medication and help youth gain insight into these temptations. Emerging methods, such as Ecological Momentary Assessment (e.g., daily diaries, cell phone text messaging), may be useful in gaining insight into the day-to-day experience of youth living with HIV. PMID:21162691

  13. High conductivity micro-wires in diamond following arbitrary paths

    NASA Astrophysics Data System (ADS)

    Sun, Bangshan; Salter, Patrick S.; Booth, Martin J.

    2014-12-01

    High quality graphitic wires embedded beneath the surface of single crystal diamond are fabricated using a combination of adaptive ultrashort pulsed laser fabrication, high numerical aperture focusing, and an axial multi-fabrication scheme. Wires are created with micrometer and sub-micrometer dimensions that can follow any three dimensional path within the diamond. The measured conductivities are over an order of magnitude greater than previously reported wires fabricated by ultra-short pulsed lasers. The increased level of graphitization control in this scheme appears particularly important for fabrication of wires parallel to the diamond surface.

  14. Direct Adherence Measurement Using an Ingestible Sensor Compared With Self-Reporting in High-Risk Cardiovascular Disease Patients Who Knew They Were Being Measured: A Prospective Intervention

    PubMed Central

    Thompson, David; Mackay, Teresa; Matthews, Maria; Edwards, Judith; Connolly, Susan B

    2017-01-01

    Background Use of appropriate cardioprotective medication is a cornerstone of cardiovascular disease prevention, but less-than-optimal patient adherence is common. Thus, strategies for improving adherence are recommended to adopt a multifaceted approach. Objective The objective of our study was to test a system comprising a biodegradable, ingestible sensor for direct measurement of medication ingestion in a group of patients at elevated cardiovascular risk attending a cardiac prevention and rehabilitation program. Methods In this prospective intervention trial in a single group of 21 patients running from April 2014 to June 2015, we measured adherence by self-report and adherence determined objectively by the system. The sensor emits a signal when it encounters the acidic environment of the stomach, detectable by an externally worn patch and linked software app. Longitudinal adherence data in the form of daily progress charts for sensed dosing events as compared with scheduled dosing are visible to patients on their tablet computer’s medication dosing app, thus providing patients with continuous medication adherence feedback. We sought feedback on patient acceptability by questionnaire assessment. Participants used the system for the 12-week period of their cardiac prevention and rehabilitation program. Results Only 1 patient at initial assessment and 1 patient at end-of-program assessment reported often missing medication. The remaining patients reported never missing medication or had missing data. Only 12 (57%) of patients overall achieved system-determined adherence of 80% or more, and 3 patients had scores below 40%. Participants reported high levels of acceptability. Conclusions This integrated system was well tolerated in a group of 21 patients over an appreciable time frame. Its ability to measure adherence reveals the sizeable disconnect between patient self-reported adherence and actual medication taking and has promising potential for clinical use as a

  15. Direct Adherence Measurement Using an Ingestible Sensor Compared With Self-Reporting in High-Risk Cardiovascular Disease Patients Who Knew They Were Being Measured: A Prospective Intervention.

    PubMed

    Thompson, David; Mackay, Teresa; Matthews, Maria; Edwards, Judith; Peters, Nicholas; Connolly, Susan B

    2017-06-12

    Use of appropriate cardioprotective medication is a cornerstone of cardiovascular disease prevention, but less-than-optimal patient adherence is common. Thus, strategies for improving adherence are recommended to adopt a multifaceted approach. The objective of our study was to test a system comprising a biodegradable, ingestible sensor for direct measurement of medication ingestion in a group of patients at elevated cardiovascular risk attending a cardiac prevention and rehabilitation program. In this prospective intervention trial in a single group of 21 patients running from April 2014 to June 2015, we measured adherence by self-report and adherence determined objectively by the system. The sensor emits a signal when it encounters the acidic environment of the stomach, detectable by an externally worn patch and linked software app. Longitudinal adherence data in the form of daily progress charts for sensed dosing events as compared with scheduled dosing are visible to patients on their tablet computer's medication dosing app, thus providing patients with continuous medication adherence feedback. We sought feedback on patient acceptability by questionnaire assessment. Participants used the system for the 12-week period of their cardiac prevention and rehabilitation program. Only 1 patient at initial assessment and 1 patient at end-of-program assessment reported often missing medication. The remaining patients reported never missing medication or had missing data. Only 12 (57%) of patients overall achieved system-determined adherence of 80% or more, and 3 patients had scores below 40%. Participants reported high levels of acceptability. This integrated system was well tolerated in a group of 21 patients over an appreciable time frame. Its ability to measure adherence reveals the sizeable disconnect between patient self-reported adherence and actual medication taking and has promising potential for clinical use as a tool to encourage better medication

  16. Conductive MOF electrodes for stable supercapacitors with high areal capacitance

    NASA Astrophysics Data System (ADS)

    Sheberla, Dennis; Bachman, John C.; Elias, Joseph S.; Sun, Cheng-Jun; Shao-Horn, Yang; Dincă, Mircea

    2016-10-01

    Owing to their high power density and superior cyclability relative to batteries, electrochemical double layer capacitors (EDLCs) have emerged as an important electrical energy storage technology that will play a critical role in the large-scale deployment of intermittent renewable energy sources, smart power grids, and electrical vehicles. Because the capacitance and charge-discharge rates of EDLCs scale with surface area and electrical conductivity, respectively, porous carbons such as activated carbon, carbon nanotubes and crosslinked or holey graphenes are used exclusively as the active electrode materials in EDLCs. One class of materials whose surface area far exceeds that of activated carbons, potentially allowing them to challenge the dominance of carbon electrodes in EDLCs, is metal-organic frameworks (MOFs). The high porosity of MOFs, however, is conventionally coupled to very poor electrical conductivity, which has thus far prevented the use of these materials as active electrodes in EDLCs. Here, we show that Ni3(2,3,6,7,10,11-hexaiminotriphenylene)2 (Ni3(HITP)2), a MOF with high electrical conductivity, can serve as the sole electrode material in an EDLC. This is the first example of a supercapacitor made entirely from neat MOFs as active materials, without conductive additives or other binders. The MOF-based device shows an areal capacitance that exceeds those of most carbon-based materials and capacity retention greater than 90% over 10,000 cycles, in line with commercial devices. Given the established structural and compositional tunability of MOFs, these results herald the advent of a new generation of supercapacitors whose active electrode materials can be tuned rationally, at the molecular level.

  17. Highly conductive paper for energy-storage devices

    PubMed Central

    Hu, Liangbing; Choi, Jang Wook; Yang, Yuan; Jeong, Sangmoo; La Mantia, Fabio; Cui, Li-Feng; Cui, Yi

    2009-01-01

    Paper, invented more than 2,000 years ago and widely used today in our everyday lives, is explored in this study as a platform for energy-storage devices by integration with 1D nanomaterials. Here, we show that commercially available paper can be made highly conductive with a sheet resistance as low as 1 ohm per square (Ω/sq) by using simple solution processes to achieve conformal coating of single-walled carbon nanotube (CNT) and silver nanowire films. Compared with plastics, paper substrates can dramatically improve film adhesion, greatly simplify the coating process, and significantly lower the cost. Supercapacitors based on CNT-conductive paper show excellent performance. When only CNT mass is considered, a specific capacitance of 200 F/g, a specific energy of 30–47 Watt-hour/kilogram (Wh/kg), a specific power of 200,000 W/kg, and a stable cycling life over 40,000 cycles are achieved. These values are much better than those of devices on other flat substrates, such as plastics. Even in a case in which the weight of all of the dead components is considered, a specific energy of 7.5 Wh/kg is achieved. In addition, this conductive paper can be used as an excellent lightweight current collector in lithium-ion batteries to replace the existing metallic counterparts. This work suggests that our conductive paper can be a highly scalable and low-cost solution for high-performance energy storage devices. PMID:19995965

  18. Conductive MOF electrodes for stable supercapacitors with high areal capacitance.

    PubMed

    Sheberla, Dennis; Bachman, John C; Elias, Joseph S; Sun, Cheng-Jun; Shao-Horn, Yang; Dincă, Mircea

    2017-02-01

    Owing to their high power density and superior cyclability relative to batteries, electrochemical double layer capacitors (EDLCs) have emerged as an important electrical energy storage technology that will play a critical role in the large-scale deployment of intermittent renewable energy sources, smart power grids, and electrical vehicles. Because the capacitance and charge-discharge rates of EDLCs scale with surface area and electrical conductivity, respectively, porous carbons such as activated carbon, carbon nanotubes and crosslinked or holey graphenes are used exclusively as the active electrode materials in EDLCs. One class of materials whose surface area far exceeds that of activated carbons, potentially allowing them to challenge the dominance of carbon electrodes in EDLCs, is metal-organic frameworks (MOFs). The high porosity of MOFs, however, is conventionally coupled to very poor electrical conductivity, which has thus far prevented the use of these materials as active electrodes in EDLCs. Here, we show that Ni3(2,3,6,7,10,11-hexaiminotriphenylene)2 (Ni3(HITP)2), a MOF with high electrical conductivity, can serve as the sole electrode material in an EDLC. This is the first example of a supercapacitor made entirely from neat MOFs as active materials, without conductive additives or other binders. The MOF-based device shows an areal capacitance that exceeds those of most carbon-based materials and capacity retention greater than 90% over 10,000 cycles, in line with commercial devices. Given the established structural and compositional tunability of MOFs, these results herald the advent of a new generation of supercapacitors whose active electrode materials can be tuned rationally, at the molecular level.

  19. Conductive MOF electrodes for stable supercapacitors with high areal capacitance

    NASA Astrophysics Data System (ADS)

    Sheberla, Dennis; Bachman, John C.; Elias, Joseph S.; Sun, Cheng-Jun; Shao-Horn, Yang; Dincă, Mircea

    2017-02-01

    Owing to their high power density and superior cyclability relative to batteries, electrochemical double layer capacitors (EDLCs) have emerged as an important electrical energy storage technology that will play a critical role in the large-scale deployment of intermittent renewable energy sources, smart power grids, and electrical vehicles. Because the capacitance and charge-discharge rates of EDLCs scale with surface area and electrical conductivity, respectively, porous carbons such as activated carbon, carbon nanotubes and crosslinked or holey graphenes are used exclusively as the active electrode materials in EDLCs. One class of materials whose surface area far exceeds that of activated carbons, potentially allowing them to challenge the dominance of carbon electrodes in EDLCs, is metal-organic frameworks (MOFs). The high porosity of MOFs, however, is conventionally coupled to very poor electrical conductivity, which has thus far prevented the use of these materials as active electrodes in EDLCs. Here, we show that Ni3(2,3,6,7,10,11-hexaiminotriphenylene)2 (Ni3(HITP)2), a MOF with high electrical conductivity, can serve as the sole electrode material in an EDLC. This is the first example of a supercapacitor made entirely from neat MOFs as active materials, without conductive additives or other binders. The MOF-based device shows an areal capacitance that exceeds those of most carbon-based materials and capacity retention greater than 90% over 10,000 cycles, in line with commercial devices. Given the established structural and compositional tunability of MOFs, these results herald the advent of a new generation of supercapacitors whose active electrode materials can be tuned rationally, at the molecular level.

  20. Thermal conduction in single-layer black phosphorus: highly anisotropic?

    PubMed

    Jiang, Jin-Wu

    2015-02-06

    The single-layer black phosphorus is characteristic for its puckered structure, which has led to distinct anisotropy in its optical, electronic, and mechanical properties. We use the non-equilibrium Green's function approach and the first-principles method to investigate the thermal conductance for single-layer black phosphorus in the ballistic transport regime, in which the phonon-phonon scattering is neglected. We find that the anisotropy in the thermal conduction is very weak for the single-layer black phosphorus--the difference between two in-plane directions is less than 4%. Our phonon calculations disclose that the out-of-plane acoustic phonon branch has lower group velocities in the direction perpendicular to the pucker, as the black phosphorus is softer in this direction, leading to a weakening effect for the thermal conductance in the perpendicular direction. However, the longitudinal acoustic phonon branch behaves abnormally; i.e., the group velocity of this phonon branch is higher in the perpendicular direction, although the single-layer black phosphorus is softer in this direction. The abnormal behavior of the longitudinal acoustic phonon branch is closely related to the highly anisotropic Poisson's ratio in the single-layer black phosphorus. As a result of the counteraction between the out-of-plane phonon mode and the in-plane phonon modes, the thermal conductance in the perpendicular direction is weaker than the parallel direction, but the anisotropy is pretty small.

  1. Highly conductive grain boundaries in copper oxide thin films

    NASA Astrophysics Data System (ADS)

    Deuermeier, Jonas; Wardenga, Hans F.; Morasch, Jan; Siol, Sebastian; Nandy, Suman; Calmeiro, Tomás; Martins, Rodrigo; Klein, Andreas; Fortunato, Elvira

    2016-06-01

    High conductivity in the off-state and low field-effect mobility compared to bulk properties is widely observed in the p-type thin-film transistors of Cu2O, especially when processed at moderate temperature. This work presents results from in situ conductance measurements at thicknesses from sub-nm to around 250 nm with parallel X-ray photoelectron spectroscopy. An enhanced conductivity at low thickness is explained by the occurrence of Cu(II), which is segregated in the grain boundary and locally causes a conductivity similar to CuO, although the surface of the thick film has Cu2O stoichiometry. Since grains grow with an increasing film thickness, the effect of an apparent oxygen excess is most pronounced in vicinity to the substrate interface. Electrical properties of Cu2O grains are at least partially short-circuited by this effect. The study focuses on properties inherent to copper oxide, although interface effects cannot be ruled out. This non-destructive, bottom-up analysis reveals phenomena which are commonly not observable after device fabrication, but clearly dominate electrical properties of polycrystalline thin films.

  2. Highly conductive grain boundaries in copper oxide thin films

    SciTech Connect

    Deuermeier, Jonas; Wardenga, Hans F.; Morasch, Jan; Siol, Sebastian; Klein, Andreas; Nandy, Suman; Calmeiro, Tomás; Martins, Rodrigo; Fortunato, Elvira

    2016-06-21

    High conductivity in the off-state and low field-effect mobility compared to bulk properties is widely observed in the p-type thin-film transistors of Cu{sub 2}O, especially when processed at moderate temperature. This work presents results from in situ conductance measurements at thicknesses from sub-nm to around 250 nm with parallel X-ray photoelectron spectroscopy. An enhanced conductivity at low thickness is explained by the occurrence of Cu(II), which is segregated in the grain boundary and locally causes a conductivity similar to CuO, although the surface of the thick film has Cu{sub 2}O stoichiometry. Since grains grow with an increasing film thickness, the effect of an apparent oxygen excess is most pronounced in vicinity to the substrate interface. Electrical properties of Cu{sub 2}O grains are at least partially short-circuited by this effect. The study focuses on properties inherent to copper oxide, although interface effects cannot be ruled out. This non-destructive, bottom-up analysis reveals phenomena which are commonly not observable after device fabrication, but clearly dominate electrical properties of polycrystalline thin films.

  3. Fabrication of setup for high temperature thermal conductivity measurement

    NASA Astrophysics Data System (ADS)

    Patel, Ashutosh; Pandey, Sudhir K.

    2017-01-01

    In this work, we report the fabrication of an experimental setup for high temperature thermal conductivity (κ) measurement. It can characterize samples with various dimensions and shapes. Steady state based axial heat flow technique is used for κ measurement. Heat loss is measured using parallel thermal conductance technique. Simple design, lightweight, and small size sample holder is developed by using a thin heater and limited components. Low heat loss value is achieved by using very low thermal conductive insulator block with small cross-sectional area. Power delivered to the heater is measured accurately by using 4-wire technique and for this, the heater is developed with 4 wires. This setup is validated by using Bi0.36Sb1.45Te3, polycrystalline bismuth, gadolinium, and alumina samples. The data obtained for these samples are found to be in good agreement with the reported data. The maximum deviation of 6% in the value κ is observed. This maximum deviation is observed with the gadolinium sample. We also report the thermal conductivity of polycrystalline tellurium from 320 K to 550 K and the nonmonotonous behavior of κ with temperature is observed.

  4. Method and apparatus for connecting high voltage leads to a high temperature super-conducting transformer

    DOEpatents

    Golner, Thomas M.; Mehta, Shirish P.

    2005-07-26

    A method and apparatus for connecting high voltage leads to a super-conducting transformer is provided that includes a first super-conducting coil set, a second super-conducting coil set, and a third super-conducting coil set. The first, second and third super-conducting coil sets are connected via an insulated interconnect system that includes insulated conductors and insulated connectors that are utilized to connect the first, second, and third super-conducting coil sets to the high voltage leads.

  5. High Conductance Loop Heat Pipes for Space Application

    NASA Astrophysics Data System (ADS)

    Semenov, Sergey Y.; Cho, Wei-Lin; Jensen, Scott M.

    2006-01-01

    Three high conductance Loop Heat Pipes (LHPs) for the Geostationary Imaging Fourier Transform Spectrometer (GIFTS) were designed, fabricated and thermal vacuum tested. One LHP with ammonia working fluid was designed for heat removal from a cryocooler cold head. Two ethane LHPs were designed to reject heat from the aft and fore optics to space. Thermal performance tests were performed in a vacuum chamber with attached masses simulating actual components. Thermal tests were also conducted on the bench and in an environmental chamber. The following features of the GIFTS LHPs were observed: (a) reliable startup and steady state operation with conductance as high as 83W/°C at various temperatures; (b) precision temperature control using compensation chamber heater during thermal cycling. Heat input power and condenser temperatures were varied periodically, while evaporator was maintained at a constant temperature. Temperature of the evaporator heat input surface fluctuated only by a fraction of a degree; (c) in addition there was no thermal performance degradation after 16 month of storage. The LHPs are installed on the instrument and waiting for a launch platform.

  6. High Surface Area Conducting Polymer Composites for Hydrogen Storage

    NASA Astrophysics Data System (ADS)

    Gutowska, Anna; Tarasevich, Barbara; Shin, Yongsoon; Ferris, Kim; Linehan, John; White, James

    2004-03-01

    We are investigating high surface area mesoporous conducting polymer composites as new materials for on-board hydrogen storage. A recent study reported significant levels of hydrogen storage in two conducting polymers, polyaniline (PANI) and polypyrrole (PPy) (8 wtPANI).1 We have used templated synthesis methods to obtain PPy and PANI composites with mesoporous structure. We have designed composites that offer a combination of several desirable properties: - favorable wt. - multiple mechanisms of hydrogen storage (physi-, chemi-sorption, and voids available for gas compression), and high surface area meoporous morphology for enhanced gas-material interactions and greater control of gas transport. Our experimental approaches to materials design were supported by computational methods aimed at developing predictive capabilities for the structure-property relationship (SPR) of electronic structure effects on hydrogen storage capacity in conducting polymers. Computational methods were also used to support design of mesoporous structures for optimized gas-material interactions and effective diffusion control of gas transport. 1. Cho, J. J.; Song, K. S.; Kim, J. W.; Kim, T. H.; Choo, K. Fuel Chemistry Div. Reprints 2002, 47, 790.

  7. Highly-conducting molecular circuits based on antiaromaticity

    NASA Astrophysics Data System (ADS)

    Fujii, Shintaro; Marqués-González, Santiago; Shin, Ji-Young; Shinokubo, Hiroshi; Masuda, Takuya; Nishino, Tomoaki; Arasu, Narendra P.; Vázquez, Héctor; Kiguchi, Manabu

    2017-07-01

    Aromaticity is a fundamental concept in chemistry. It is described by Hückel's rule that states that a cyclic planar π-system is aromatic when it shares 4n+2 π-electrons and antiaromatic when it possesses 4n π-electrons. Antiaromatic compounds are predicted to exhibit remarkable charge transport properties and high redox activities. However, it has so far only been possible to measure compounds with reduced aromaticity but not antiaromatic species due to their energetic instability. Here, we address these issues by investigating the single-molecule charge transport properties of a genuinely antiaromatic compound, showing that antiaromaticity results in an order of magnitude increase in conductance compared with the aromatic counterpart. Single-molecule current-voltage measurements and ab initio transport calculations reveal that this results from a reduced energy gap and a frontier molecular resonance closer to the Fermi level in the antiaromatic species. The conductance of the antiaromatic complex is further modulated electrochemically, demonstrating its potential as a high-conductance transistor.

  8. The zwitterion effect in high-conductivity polyelectrolyte materials.

    PubMed

    Tiyapiboonchaiya, Churat; Pringle, Jennifer M; Sun, Jiazeng; Byrne, Nolene; Howlett, Patrick C; MacFarlane, Douglas R; Forsyth, Maria

    2004-01-01

    The future of lithium metal batteries as a widespread, safe and reliable form of high-energy-density rechargeable battery depends on a significant advancement in the electrolyte material used in these devices. Molecular solvent-based electrolytes have been superceded by polymer electrolytes in some prototype devices, primarily in a drive to overcome leakage and flammability problems, but these often exhibit low ionic conductivity and prohibitively poor lithium-ion transport. To overcome this, it is necessary to encourage dissociation of the lithium ion from the anionic polymer backbone, ideally without the introduction of competing, mobile ionic species. Here we demonstrate the effect of zwitterionic compounds, where the cationic and anionic charges are immobilized on the same molecule, as extremely effective lithium ion 'dissociation enhancers'. The zwitterion produces electrolyte materials with conductivities up to seven times larger than the pure polyelectrolyte gels, a phenomenon that appears to be common to a number of different copolymer and solvent systems.

  9. High Power Tests of Normal Conducting Single-Cell Structures

    SciTech Connect

    Dolgashev, V.A.; Tantawi, S.G.; Nantista, C.D.; Higashi, Y.; Higo, T.; /KEK, Tsukuba

    2007-11-07

    We report the results of the first high power tests of single-cell traveling-wave and standing-wave structures. These tests are part of an experimental and theoretical study of rf breakdown in normal conducting structures at 11.4 GHz. The goal of this study is to determine the gradient potential of normal-conducting rf-powered particle beam accelerators. The test setup consists of reusable mode converters and short test structures and is powered by SLAC's XL-4 klystron. This setup was created for economical testing of different cell geometries, cell materials and preparation techniques with short turn-around time. The mode launchers and structures were manufactured at SLAC and KEK and tested in the SLAC Klystron Test Lab.

  10. Mechanical property determination of high conductivity metals and alloys

    NASA Technical Reports Server (NTRS)

    Harrod, D. L.; Vandergrift, E.; France, L.

    1973-01-01

    Pertinent mechanical properties of three high conductivity metals and alloys; namely, vacuum hot pressed grade S-200E beryllium, OFHC copper and beryllium-copper alloy no. 10 were determined. These materials were selected based on their possible use in rocket thrust chamber and nozzle hardware. They were procured in a form and condition similar to that which might be ordered for actual hardware fabrication. The mechanical properties measured include (1) tension and compression stress strain curves at constant strain rate (2) tensile and compressive creep, (3) tensile and compressive stress-relaxation behavior and (4) elastic properties. Tests were conducted over the temperature range of from 75 F to 1600 F. The resulting data is presented in both graphical and tabular form.

  11. Transient Response of Different Highly Conductive PCM Composites

    NASA Astrophysics Data System (ADS)

    Mahmoud Alhamdo, Mohammed H.; Bdaiwi, Bashar A.; Hasan, Ali H.

    In this work, the thermal conductivity of paraffin wax has been enhanced by employing four different high conductivity additives infiltrated within the PCM. These include the use of Graphite Powder (GP), Copper Particles (CP), Aluminum oxide Particles (AP), and Copper Network (CN). Four different types of pure waxes were selected, tested and compared. Twelve samples of wax/additives composites were prepared by adding different mass ratios of 3, 6 and 9 % of additives by weight in each type of wax. The storage system contains spherical capsules filled with composite PCMs that are packed in an insulated cylindrical storage. Transient temperature based governing equations have been developed and solved numerically by both ANSYS FLUENT 14 code and by numerical implicit time marching model. With progress of time, results showed that the numerical predictions of ANSYS software start to deviate from the experimental observations. The grade-B paraffin was found to be the best one. Results indicate that all the enhancement methods have significant effect on the thermal response of the system. However, the utilization of 6 % additives by weight has been found to provide the best enhancement effect. The developed new-sort CN composite is found to produce the best thermal response due to its good homogeneity with wax and its high conductivity. Results showed that for CN composite with 6 % additives, the charging and discharging time decreased by 26.4 and 30.3 % respectively than that of pure wax and the thermal conductivity enhanced by 2.57 times that of pure wax.

  12. High-strength carbon nanotube fibre-like ribbon with high ductility and high electrical conductivity.

    PubMed

    Wang, J N; Luo, X G; Wu, T; Chen, Y

    2014-06-25

    Macroscopic fibres made up of carbon nanotubes exhibit properties far below theoretical predictions and even much lower than those for conventional carbon fibres. Here we report improvements of mechanical and electrical properties by more than one order of magnitude by pressurized rolling. Our carbon nanotubes self-assemble to a hollow macroscopic cylinder in a tube reactor operated at high temperature and then condense in water or ethanol to form a fibre, which is continually spooled in an open-air environment. This initial fibre is densified by rolling under pressure, leading to a combination of high tensile strength (3.76-5.53 GPa), high tensile ductility (8-13%) and high electrical conductivity ((1.82-2.24) × 10(4) S cm(-1)). Our study therefore demonstrates strategies for future performance maximization and the very considerable potential of carbon nanotube assemblies for high-end uses.

  13. High Adherence to Iron/Folic Acid Supplementation during Pregnancy Time among Antenatal and Postnatal Care Attendant Mothers in Governmental Health Centers in Akaki Kality Sub City, Addis Ababa, Ethiopia: Hierarchical Negative Binomial Poisson Regression

    PubMed Central

    Gebreamlak, Bisratemariam; Dadi, Abel Fekadu; Atnafu, Azeb

    2017-01-01

    Background Iron deficiency during pregnancy is a risk factor for anemia, preterm delivery, and low birth weight. Iron/Folic Acid supplementation with optimal adherence can effectively prevent anemia in pregnancy. However, studies that address this area of adherence are very limited. Therefore, the current study was conducted to assess the adherence and to identify factors associated with a number of Iron/Folic Acid uptake during pregnancy time among mothers attending antenatal and postnatal care follow up in Akaki kality sub city. Methods Institutional based cross-sectional study was conducted on a sample of 557 pregnant women attending antenatal and postnatal care service. Systematic random sampling was used to select study subjects. The mothers were interviewed and the collected data was cleaned and entered into Epi Info 3.5.1 and analyzed by R version 3.2.0. Hierarchical Negative Binomial Poisson Regression Model was fitted to identify the factors associated with a number of Iron/Folic Acid uptake. Adjusted Incidence rate ratio (IRR) with 95% confidence interval (CI) was computed to assess the strength and significance of the association. Result More than 90% of the mothers were supplemented with at least one Iron/Folic Acid supplement from pill per week during their pregnancy time. Sixty percent of the mothers adhered (took four or more tablets per week) (95%CI, 56%—64.1%). Higher IRR of Iron/Folic Acid supplementation was observed among women: who received health education; which were privately employed; who achieved secondary education; and who believed that Iron/Folic Acid supplements increase blood, whereas mothers who reported a side effect, who were from families with relatively better monthly income, and who took the supplement when sick were more likely to adhere. Conclusion Adherence to Iron/Folic Acid supplement during their pregnancy time among mothers attending antenatal and postnatal care was found to be high. Activities that would address the

  14. Advanced Liquid-Cooling Garment Using Highly Thermally Conductive Sheets

    NASA Technical Reports Server (NTRS)

    Ruemmele, Warren P.; Bue, Grant C.; Orndoff, Evelyne; Tang, Henry

    2010-01-01

    This design of the liquid-cooling garment for NASA spacesuits allows the suit to remove metabolic heat from the human body more effectively, thereby increasing comfort and performance while reducing system mass. The garment is also more flexible, with fewer restrictions on body motion, and more effectively transfers thermal energy from the crewmember s body to the external cooling unit. This improves the garment s performance in terms of the maximum environment temperature in which it can keep a crewmember comfortable. The garment uses flexible, highly thermally conductive sheet material (such as graphite), coupled with cooling water lines of improved thermal conductivity to transfer the thermal energy from the body to the liquid cooling lines more effectively. The conductive sheets can be layered differently, depending upon the heat loads, in order to provide flexibility, exceptional in-plane heat transfer, and good through-plane heat transfer. A metal foil, most likely aluminum, can be put between the graphite sheets and the external heat source/sink in order to both maximize through-plane heat transfer at the contact points, and to serve as a protection to the highly conductive sheets. Use of a wicking layer draws excess sweat away from the crewmember s skin and the use of an outer elastic fabric ensures good thermal contact of the highly conductive underlayers with the skin. This allows the current state of the art to be improved by having cooling lines that can be more widely spaced to improve suit flexibility and to reduce weight. Also, cooling liquid does not have to be as cold to achieve the same level of cooling. Specific areas on the human body can easily be targeted for greater or lesser cooling to match human physiology, a warmer external environment can be tolerated, and spatial uniformity of the cooling garment can be improved to reduce vasoconstriction limits. Elements of this innovation can be applied to other embodiments to provide effective heat

  15. Flux-freezing breakdown in high-conductivity magnetohydrodynamic turbulence.

    PubMed

    Eyink, Gregory; Vishniac, Ethan; Lalescu, Cristian; Aluie, Hussein; Kanov, Kalin; Bürger, Kai; Burns, Randal; Meneveau, Charles; Szalay, Alexander

    2013-05-23

    The idea of 'frozen-in' magnetic field lines for ideal plasmas is useful to explain diverse astrophysical phenomena, for example the shedding of excess angular momentum from protostars by twisting of field lines frozen into the interstellar medium. Frozen-in field lines, however, preclude the rapid changes in magnetic topology observed at high conductivities, as in solar flares. Microphysical plasma processes are a proposed explanation of the observed high rates, but it is an open question whether such processes can rapidly reconnect astrophysical flux structures much greater in extent than several thousand ion gyroradii. An alternative explanation is that turbulent Richardson advection brings field lines implosively together from distances far apart to separations of the order of gyroradii. Here we report an analysis of a simulation of magnetohydrodynamic turbulence at high conductivity that exhibits Richardson dispersion. This effect of advection in rough velocity fields, which appear non-differentiable in space, leads to line motions that are completely indeterministic or 'spontaneously stochastic', as predicted in analytical studies. The turbulent breakdown of standard flux freezing at scales greater than the ion gyroradius can explain fast reconnection of very large-scale flux structures, both observed (solar flares and coronal mass ejections) and predicted (the inner heliosheath, accretion disks, γ-ray bursts and so on). For laminar plasma flows with smooth velocity fields or for low turbulence intensity, stochastic flux freezing reduces to the usual frozen-in condition.

  16. High conductance ohmic junction for monolithic semiconductor devices

    NASA Technical Reports Server (NTRS)

    Lewis, Carol R. (Inventor)

    1988-01-01

    In order to increase the efficiency of solar cells, a monolithic stacked device is constructed comprising a plurality of solar sub-cells adjusted for different bands of radiation. The interconnection between these sub-cells has been a significant technical problem. The invention provides an interconnection which is a thin layer of high ohmic conductance material formed between the sub-cells. Such a layer tends to form beads which serve as a shorting interconnect while passing a large fraction of the radiation to the lower sub-cells and permitting lattice-matching between the sub-cells to be preserved.

  17. Development of a high capacity variable conductance heat pipe.

    NASA Technical Reports Server (NTRS)

    Kosson, R.; Hembach, R.; Edelstein, F.; Loose, J.

    1973-01-01

    The high-capacity, pressure-primed, tunnel-artery wick concept was used in a gas-controlled variable conductance heat pipe. A variety of techniques were employed to control the size of gas/vapor bubbles trapped within the artery. Successful operation was attained with a nominal 6-foot long, 1-inch diameter cold reservoir VCHP using ammonia working fluid and nitrogen control gas. The pipe contained a heat exchanger to subcool the liquid in the artery. Maximum transport capacity with a 46-inch effective length was 1200 watts level (more than 50,000 watt-inches) and 800 watts at 0.5-inch adverse tilt.

  18. Effect of high-fructose corn syrup on the acidogenicity, adherence and biofilm formation of Streptococcus mutans.

    PubMed

    Ma, R; Sun, M; Wang, S; Kang, Q; Huang, L; Li, T; Xia, W-W

    2013-06-01

    Although high-fructose corn syrup (HFCS) as a kind of sugar has been widely used in manufactured foods recently, there is little information available regarding its cariogenicity. The aim of this study was to evaluate the cariogenic potential of HFCS. Streptococcus mutans UA159 was inoculated into HFCS media and cultivated. The pH of each culture was measured to assess acidogenicity. Spectrophotometric turbidity was measured to determine the percentage of adherence. Confocal laser scanning microscopy and SYTO-9 staining were employed to observe biofilm formation. Sucrose media was used as a positive control. The ΔpH in HFCS media was significantly larger than that in sucrose media and the pH in HFCS media decreased faster (p < 0.05). The percentage of adherence of S. mutans in HFCS media was significantly lower than that in sucrose media (p < 0.05). The biofilm formed in sucrose media was significantly thicker than that in HFCS media (p < 0.05). The results of this study suggest that the cariogenicity of S. mutans in the presence of HFCS may differ compared to its cariogenicity in the presence of sucrose. Further in vivo studies need to be undertaken to resolve this uncertainty. © 2013 Australian Dental Association.

  19. Laser surface modification of titanium substrate for pulsed laser deposition of highly adherent hydroxyapatite.

    PubMed

    Rajesh, P; Muraleedharan, C V; Komath, Manoj; Varma, Harikrishna

    2011-07-01

    Biomedical implant devices made out of titanium and its alloys are benefited by a modified surface or a bioactive coating to enhance bone bonding ability and to function effectively in vivo for the intended period of time. In this respect hydroxyapatite coating developed through pulsed laser deposition is a promising approach. Since the success of the bioactive ceramic coated implant depends mainly on the substrate-coating strength; an attempt has been made to produce micro patterned surface structure on titanium substrate for adherent hydroxyapatite coating. A pulsed Nd-YAG laser beam (355 nm) with 10 Hz repetition rate was used for surface treatment of titanium as well as hydroxyapatite deposition. The unfocussed laser beam was used to modify the substrate surface with 500-18,000 laser pulses while keeping the polished substrate in water. Hydroxyapatite deposition was done in a vacuum deposition chamber at 400 °C with the focused laser beam under 1 × 10⁻³ mbar oxygen pressure. Deposits were analyzed to understand the physico-chemical, morphological and mechanical characteristics. The obtained substrate and coating surface morphology indicates that laser treatment method can provide controlled micro-topography. Scratch test analysis and microindentation hardness values of coating on laser treated substrate indicate higher mechanical adhesion with respect to coatings on untreated substrates.

  20. Highly Efficient Neural Conversion of Human Pluripotent Stem Cells in Adherent and Animal‐Free Conditions

    PubMed Central

    Lukovic, Dunja; Diez Lloret, Andrea; Stojkovic, Petra; Rodríguez‐Martínez, Daniel; Perez Arago, Maria Amparo; Rodriguez‐Jimenez, Francisco Javier; González‐Rodríguez, Patricia; López‐Barneo, José; Sykova, Eva; Jendelova, Pavla; Kostic, Jelena; Moreno‐Manzano, Victoria; Stojkovic, Miodrag; Bhattacharya, Shomi S.

    2017-01-01

    Abstract Neural differentiation of human embryonic stem cells (hESCs) and induced pluripotent stem cells (hiPSCs) can produce a valuable and robust source of human neural cell subtypes, holding great promise for the study of neurogenesis and development, and for treating neurological diseases. However, current hESCs and hiPSCs neural differentiation protocols require either animal factors or embryoid body formation, which decreases efficiency and yield, and strongly limits medical applications. Here we develop a simple, animal‐free protocol for neural conversion of both hESCs and hiPSCs in adherent culture conditions. A simple medium formula including insulin induces the direct conversion of >98% of hESCs and hiPSCs into expandable, transplantable, and functional neural progenitors with neural rosette characteristics. Further differentiation of neural progenitors into dopaminergic and spinal motoneurons as well as astrocytes and oligodendrocytes indicates that these neural progenitors retain responsiveness to instructive cues revealing the robust applicability of the protocol in the treatment of different neurodegenerative diseases. The fact that this protocol includes animal‐free medium and human extracellular matrix components avoiding embryoid bodies makes this protocol suitable for the use in clinic. Stem Cells Translational Medicine 2017;6:1217–1226 PMID:28213969

  1. Highly Efficient Neural Conversion of Human Pluripotent Stem Cells in Adherent and Animal-Free Conditions.

    PubMed

    Lukovic, Dunja; Diez Lloret, Andrea; Stojkovic, Petra; Rodríguez-Martínez, Daniel; Perez Arago, Maria Amparo; Rodriguez-Jimenez, Francisco Javier; González-Rodríguez, Patricia; López-Barneo, José; Sykova, Eva; Jendelova, Pavla; Kostic, Jelena; Moreno-Manzano, Victoria; Stojkovic, Miodrag; Bhattacharya, Shomi S; Erceg, Slaven

    2017-04-01

    Neural differentiation of human embryonic stem cells (hESCs) and induced pluripotent stem cells (hiPSCs) can produce a valuable and robust source of human neural cell subtypes, holding great promise for the study of neurogenesis and development, and for treating neurological diseases. However, current hESCs and hiPSCs neural differentiation protocols require either animal factors or embryoid body formation, which decreases efficiency and yield, and strongly limits medical applications. Here we develop a simple, animal-free protocol for neural conversion of both hESCs and hiPSCs in adherent culture conditions. A simple medium formula including insulin induces the direct conversion of >98% of hESCs and hiPSCs into expandable, transplantable, and functional neural progenitors with neural rosette characteristics. Further differentiation of neural progenitors into dopaminergic and spinal motoneurons as well as astrocytes and oligodendrocytes indicates that these neural progenitors retain responsiveness to instructive cues revealing the robust applicability of the protocol in the treatment of different neurodegenerative diseases. The fact that this protocol includes animal-free medium and human extracellular matrix components avoiding embryoid bodies makes this protocol suitable for the use in clinic. Stem Cells Translational Medicine 2017;6:1217-1226. © 2017 The Authors Stem Cells Translational Medicine published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

  2. High efficiency, site-specific transfection of adherent cells with siRNA using microelectrode arrays (MEA).

    PubMed

    Patel, Chetan; Muthuswamy, Jit

    2012-09-13

    The discovery of RNAi pathway in eukaryotes and the subsequent development of RNAi agents, such as siRNA and shRNA, have achieved a potent method for silencing specific genes for functional genomics and therapeutics. A major challenge involved in RNAi based studies is the delivery of RNAi agents to targeted cells. Traditional non-viral delivery techniques, such as bulk electroporation and chemical transfection methods often lack the necessary spatial control over delivery and afford poor transfection efficiencies. Recent advances in chemical transfection methods such as cationic lipids, cationic polymers and nanoparticles have resulted in highly enhanced transfection efficiencies. However, these techniques still fail to offer precise spatial control over delivery that can immensely benefit miniaturized high-throughput technologies, single cell studies and investigation of cell-cell interactions. Recent technological advances in gene delivery have enabled high-throughput transfection of adherent cells, a majority of which use microscale electroporation. Microscale electroporation offers precise spatio-temporal control over delivery (up to single cells) and has been shown to achieve high efficiencies. Additionally, electroporation based approaches do not require a prolonged period of incubation (typically 4 hours) with siRNA and DNA complexes as necessary in chemical based transfection methods and lead to direct entry of naked siRNA and DNA molecules into the cell cytoplasm. As a consequence gene expression can be achieved as early as six hours after transfection. Our lab has previously demonstrated the use of microelectrode arrays (MEA) for site-specific transfection in adherent mammalian cell cultures. In the MEA based approach, delivery of genetic payload is achieved via localized micro-scale electroporation of cells. An application of electric pulse to selected electrodes generates local electric field that leads to electroporation of cells present in the region

  3. Tracking in real time the crawling dynamics of adherent living cells with a high resolution surface plasmon microscope

    NASA Astrophysics Data System (ADS)

    Streppa, L.; Berguiga, L.; Boyer Provera, E.; Ratti, F.; Goillot, E.; Martinez Torres, C.; Schaeffer, L.; Elezgaray, Juan; Arneodo, A.; Argoul, F.

    2016-03-01

    We introduce a high resolution scanning surface plasmon microscope for long term imaging of living adherent mouse myoblast cells. The coupling of a high numerical aperture objective lens with a fibered heterodyne interferometer provides both enhanced sensitivity and long term stability. This microscope takes advantage of the plasmon resonance excitation and the amplification of the electromagnetic field in near-field distance to the gold coated coverslip. This plasmon enhanced evanescent wave microscopy is particularly attractive for the study of cell adhesion and motility since it can be operated without staining of the biological sample. We show that this microscope allows very long-term imaging of living samples, and that it can capture and follow the temporal deformation of C2C12 myoblast cell protusions (lamellipodia), during their migration on a at surface.

  4. Subgap conductivity in SIN-junctions of high barrier transparency

    NASA Astrophysics Data System (ADS)

    Lotkhov, S. V.; Balashov, D. V.; Khabipov, M. I.; Buchholz, F.-I.; Zorin, A. B.

    2006-11-01

    We investigate the current-voltage characteristics of high-transparency superconductor-insulator-normal metal (SIN) junctions with the specific tunnel resistance ρ ≲ 30 Ω μm2. The junctions were fabricated from different superconducting and normal conducting materials, including Nb, Al, AuPd and Cu. The subgap leakage currents were found to be appreciably larger than those given by the standard tunnelling model. We explain our results using the model of two-electron tunnelling in the coherent diffusive transport regime. We demonstrate that even in the high-transparency SIN-junctions, a noticeable reduction of the subgap current can be achieved by splitting a junction into several submicron sub-junctions. These structures can be used as nonlinear low-noise shunts in rapid-single-flux-quantum (RSFQ) circuitry for controlling Josephson qubits.

  5. Unusually High and Anisotropic Thermal Conductivity in Amorphous Silicon Nanostructures.

    PubMed

    Kwon, Soonshin; Zheng, Jianlin; Wingert, Matthew C; Cui, Shuang; Chen, Renkun

    2017-02-02

    Amorphous Si (a-Si) nanostructures are ubiquitous in numerous electronic and optoelectronic devices. Amorphous materials are considered to possess the lower limit to the thermal conductivity (κ), which is ∼1 W·m(-1) K(-1) for a-Si. However, recent work suggested that κ of micrometer-thick a-Si films can be greater than 3 W·m(-1) K(-1), which is contributed to by propagating vibrational modes, referred to as "propagons". However, precise determination of κ in a-Si has been elusive. Here, we used structures of a-Si nanotubes and suspended a-Si films that enabled precise in-plane thermal conductivity (κ∥) measurement within a wide thickness range of 5 nm to 1.7 μm. We showed unexpectedly high κ∥ in a-Si nanostructures, reaching ∼3.0 and 5.3 W·m(-1) K(-1) at ∼100 nm and 1.7 μm, respectively. Furthermore, the measured κ∥ is significantly higher than the cross-plane κ on the same films. This unusually high and anisotropic thermal conductivity in the amorphous Si nanostructure manifests the surprisingly broad propagon mean free path distribution, which is found to range from 10 nm to 10 μm, in the disordered and atomically isotropic structure. This result provides an unambiguous answer to the century-old problem regarding mean free path distribution of propagons and also sheds light on the design and performance of numerous a-Si based electronic and optoelectronic devices.

  6. High-Temperature Proton-Conducting Ceramics Developed

    NASA Technical Reports Server (NTRS)

    Sayir, Ali; Dynys, Frederick W.; Berger, M. H.

    2005-01-01

    High-temperature protonic conductors (HTPC) are needed for hydrogen separation, hydrogen sensors, fuel cells, and hydrogen production from fossil fuels. The HTPC materials for hydrogen separation at high temperatures are foreseen to be metal oxides with the perovskite structure A(sup 2+)B(sup 4+)C(sup 2-, sub 3) and with the trivalent cation (M(sup 3+)) substitution at the B(sup 4+)-site to introduce oxygen vacancies. The high affinity for hydrogen ions (H(sup +)) is advantageous for protonic transport, but it increases the reactivity toward water (H2O) and carbon dioxide (CO2), which can lead to premature membrane failure. In addition, there are considerable technological challenges related to the processing of HTPC materials. The high melting point and multi-cation chemistry of HTPC materials creates difficulties in in achieving high-density, single-phase membranes by solid-state sintering. The presence of secondary phases and grain-boundary interfaces are detrimental to the protonic conduction and environmental stability of polycrystalline HTPC materials.

  7. Sodium-sulfur cells with high conductivity glass electrolytes

    NASA Astrophysics Data System (ADS)

    Nelson, P. A.; Bloom, I.; Bradley, J.; Roche, M. F.

    1985-05-01

    A study is under way to develop glasses in the soda-alumina-zirconia-silica system that have high conductivity for sodium ions. Sodium-conductivity and corrosion experiments indicate that the target resistivity of 100 ohm-cm at 300(0)C can be achieved for glasses having satisfactory corrosion resistance for use in sodium-sulfur cells. The low resistivity makes possible a unique approach to cell design. Cells of 150 A-hr capacity were designed having 6-mm dia electrolytes and are expected to achieve a specific energy of up to 270 W-hr/kg. Others having 1.5-mm dia electrolytes are expected to attain a specific power of up to 2 or 3 kW/kg. Excellent heat removal can be provided for high-specific-power cells by short metallic paths from the center of the cell to the cooled cell wall. Reliability of the cell may be achieved by: (1) use of a protective tube around each electrolyte tube to protect against failure propagation, and (2) the provision for automatic disconnection of a failed element by burnout of its current collector wire.

  8. The thermal conductivity of electrically-conducting liquids at high pressures

    NASA Astrophysics Data System (ADS)

    Wakeham, W. A.; Zalaf, M.

    1986-05-01

    The paper describes a new instrument for the measurement of the thermal conductivity of electrically-conducting liquids at pressures up to 700 MPa with an accuracy of ±0.3%. The instrument is based upon the transient hot-wire principle and the novel features that make it applicable to electrically-conducting fluids are described. In particular a new automatic bridge for the direct measurement of the temperature rise of the hot-wires is discussed.

  9. A Systematic Review of Adherence to Oral Antineoplastic Therapies

    PubMed Central

    Amoyal, Nicole; Nisotel, Lauren; Fishbein, Joel N.; MacDonald, James; Stagl, Jamie; Lennes, Inga; Temel, Jennifer S.; Safren, Steven A.; Pirl, William F.

    2016-01-01

    Background. Oral antineoplastic therapies not only improve survival but also reduce the burden of care for patients. Yet patients and clinicians face new challenges in managing adherence to these oral therapies. We conducted a systematic literature review to assess rates and correlates of adherence to oral antineoplastic therapies and interventions aimed at improving adherence. Methods. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we conducted a comprehensive literature search of the Ovid MEDLINE database from January 1, 2003 to June 30, 2015, using relevant terminology for oral antineoplastic agents. We included observational, database, and intervention studies. At least two researchers evaluated each paper to ensure accuracy of results and determine risk of bias. Results. We identified 927 records from the search and screened 214 abstracts. After conducting a full-text review of 167 papers, we included in the final sample 51 papers on rates/correlates of adherence to oral antineoplastic therapy and 12 papers on intervention studies to improve adherence. Rates of adherence varied widely, from 46% to 100%, depending on patient sample, medication type, follow-up period, assessment measure, and calculation of adherence. Of the intervention studies, only 1 of the randomized trials and 2 of the cohort studies showed benefit regarding adherence, with the majority suffering high risk of bias. Conclusions. Although no reliable estimate of adherence to oral antineoplastic therapies can be gleaned from the literature, a substantial proportion of patients struggle to adhere to these medications as prescribed. The few intervention studies for adherence have notable methodological concerns, thereby limiting the evidence to guide practice in promoting medication adherence among patients with cancer. Implications for Practice: Given the tremendous growth and development of oral antineoplastic therapies in the last decade, significant

  10. Understanding Specific Contexts of Antiretroviral Therapy Adherence in Rural South Africa: A Thematic Analysis of Digital Stories from a Community with High HIV Prevalence

    PubMed Central

    Treffry-Goatley, Astrid; Lessells, Richard; Sykes, Pam; Bärnighausen, Till; de Oliveira, Tulio; Moletsane, Relebohile; Seeley, Janet

    2016-01-01

    Near-perfect adherence to antiretroviral therapy (ART) is required to achieve the best possible prevention and treatment outcomes. Yet, there have been particular concerns about the challenges of adherence among patients living in resource-limited settings in sub-Saharan Africa. The primary objective of this study was to explore adherence in a low-resourced, rural community of high HIV prevalence in South Africa and to identify specific individual and structural factors that can either challenge or support adherence in this context. We applied digital stories as a qualitative research tool to gain insights into personal contexts of HIV and ART adherence. Through an inductive thematic analysis of twenty story texts, soundtracks and drawings, we explored experiences, understandings, and contexts of the participants and identified potential barriers and facilitators for those on lifelong treatment. We found that many of the stories reflected a growing confidence in the effectiveness of ART, which should be viewed as a key facilitator to successful adherence since this attitude can promote disclosure and boost access to social support. Nevertheless, stories also highlighted the complexity of the issues that individuals and households face as they deal with HIV and ART in this setting and it is clear that an overburdened local healthcare system has often struggled to meet the demands of a rapidly expanding epidemic and to provide the necessary medical and emotional support. Our analysis suggests several opportunities for further research and the design of novel health interventions to support optimal adherence. Firstly, future health promotion campaigns should encourage individuals to test together, or at least accompany each other for testing, to encourage social support from the outset. Additionally, home-based testing and ART club interventions might be recommended to make it easier for individuals to adhere to their treatment regimens and to provide a sense of

  11. Patient Education in a 14-month Randomised Trial Fails to Improve Adherence in Ulcerative Colitis: Influence of Demographic and Clinical Parameters on Non-adherence.

    PubMed

    Nikolaus, S; Schreiber, S; Siegmund, B; Bokemeyer, B; Bästlein, E; Bachmann, O; Görlich, D; Hofmann, U; Schwab, M; Kruis, W

    2017-09-01

    Recent observational studies document that non-adherence to mesalamine therapy during remission is frequent. We aimed to investigate patient impact of patient education using objective assessments of adherence. A 14-month randomised, prospective clinical trial of adherence to mesalamine was conducted in 248 patients with ulcerative colitis [UC], Colitis Activity Index [CAI] ≤ 9, receiving standard care [n = 122] versus a standardised patient education programme [n = 126]. Primary endpoint was adherence at all visits (5-aminosalicylic acid [5-ASA] urine levels). Secondary endpoints included quality of life (inflammatory bowel disease questionnaise [IBDQ]), disease activity, partial adherence, and self-assessment of adherence. Patient allocation was well balanced. Baseline non-adherence was high in quiescent/mildly active UC [52.4%] without difference between the groups (52.4% of patients in the education group versus 52.5% in the standard care group [p = 0.99]). No difference between the intervention group and standard care was seen in IBDQ, partial adherence, self-assessment of adherence, or therapy satisfaction at all visits. We suggest a model in which individual risks for non-adherence are driven by patients with young age, short disease duration, and low education levels. Non-adherence is frequent in a population with quiescent/mildly active UC. Although more than 25% of the population was not in remission at the various time points, no relationship between disease activity and adherence was seen over the 14-month observation period. Physicians should maximise their efforts to motivate high-risk patients for adherence. Future trials should use objective exposure assessments to examine the impact of continuous education and consultations on the background of individual risks to develop non-adherence.

  12. Highly conductive Li garnets by a multielement doping strategy.

    PubMed

    Tong, Xia; Thangadurai, Venkataraman; Wachsman, Eric D

    2015-04-06

    Highly conductive Li7La3Zr2O12 (LLZ) garnet-type solid electrolytes were further optimized to improve Li-ion conduction by La(3+)-sites substitution with Ba(2+) and Zr(4+)-sites substitution with Ta(5+) and Nb(5+). Garnet-structured metal oxides of the nominal chemical compositions Li6.65La2.75Ba0.25Zr1.4Ta0.5Nb0.1O12, Li6.4La3Zr1.4Ta0.6-xNbxO12 (x = 0, 0.1, 0.2, and 0.3), and the parent LLZ, as a reference, were prepared via conventional solid-state reaction to investigate the effect of multielement doping on ionic conductivity. The phase formation, morphology, and Li ion conductivity were characterized using powder X-ray diffraction (PXRD), scanning electron microscopy, and alternating current impedance spectroscopy methods, respectively. In addition, solid-state (27)Al and (7)Li magic-angle spinning (MAS) NMR was used to study the effect of "Al doping" on the investigated multielement doped Li-stuffed garnet metal oxides. All the prepared samples obtained the cubic garnet-type structure (space group: Ia3̅d; No. 230) at 1150 °C, similar to that of cubic LLZ. Except for Li6.4La3Zr1.4Ta0.6O12, all the members show Al content by Al MAS NMR. However, it was not possible to detect Al-based impurity phases using PXRD in any of the investigated garnets. Among the samples investigated in this work, "Al-free" Li6.4La3Zr1.4Ta0.6O12 demonstrated a bulk Li ion conductivity of 0.72 mS cm(-1) at 25 °C, with apparent activation energy of 0.26 eV, significantly higher than the parent LLZ.

  13. Poor medication adherence to bisphosphonates and high self-perception of aging in elderly female patients with osteoporosis.

    PubMed

    Wu, X; Wei, D; Sun, B; Wu, X N

    2016-10-01

    Non-adherence to bisphosphonates exposes the elderly female osteoporosis patients to an increased risk of fracture. This was one of the first studies to explore the relationship between medication adherence and self-perception of aging. Feelings of lacking control and expectations for negative events, beliefs of illness's chronic duration nature, and its linkage with aging were associated with of poor medication adherence. To examine the relationship between medication adherence to bisphosphonates and self-perception of aging in elderly female patients with osteoporosis. This was a cross-sectional survey. A convenience sample of 245 elderly female patients with osteoporosis prescribed regular oral bisphosphonate therapy was recruited from three tertiary hospitals in China. Sociodemographic and osteoporosis-related data, Morisky Medication Adherence Scale-8 (MMAS-8) and Aging Perceptions Questionnaire (APQ) data were collected. Mean adherence score measured by MMAS-8 was 4.46(SD = 1.91; range, 0.25-7.00). Percentages of good and poor adherence were 28.6 and 71.4 %, which showed a poor medication adherence. Six domains of APQ statistically significantly associated with medication adherence. Interestingly, with control of age, educational status, marital status, and symptoms accompanying osteoporosis as covariates in the multivariate linear regression model, the effects of three domains disappeared. Significantly, worse adherence was observed in those patients who had higher feelings of lack of control, more expectations for negative events, more beliefs of osteoporosis's chronic duration nature and its linkage with aging. We conclude that feelings of lacking control, expectations for negative events, beliefs of illness's chronic duration nature, and its linkage with aging were associated with poor medication adherence in elderly female patients with osteoporosis. Concerns about self-perception of aging need to be addressed in order to improve medication adherence.

  14. Relationship of race-, sexual orientation-, and HIV-related discrimination with adherence to HIV treatment: a pilot study.

    PubMed

    Boarts, Jessica M; Bogart, Laura M; Tabak, Melanie A; Armelie, Aaron P; Delahanty, Douglas L

    2008-10-01

    Adherence to highly active antiretroviral therapy (HAART) must be close to perfect in order to maintain suppression of HIV viral load, and to prevent the development of drug resistant strains of HIV. People living with HIV (PLWH) often report low levels of adherence. One variable that has been linked to poor adherence is perceived discrimination; however, research has generally not considered the possible unique effects of different types of discrimination on adherence. The present pilot study aimed to examine the association of three types of discrimination (due to HIV+ status, race, or sexual orientation) with adherence among 57 PLWH. Logistic regression analyses were conducted to demonstrate the relationships between each type of discrimination and self-reported adherence. Racial discrimination significantly predicted lower adherence levels, whereas sexual orientation- and HIV-related discrimination did not. Results underscore the importance of addressing discrimination issues, specifically racial, when designing interventions to improve adherence to HAART.

  15. How Patients Take Malaria Treatment: A Systematic Review of the Literature on Adherence to Antimalarial Drugs

    PubMed Central

    Bruxvoort, Katia; Goodman, Catherine; Kachur, S. Patrick; Schellenberg, David

    2014-01-01

    Background High levels of patient adherence to antimalarial treatment are important in ensuring drug effectiveness. To achieve this goal, it is important to understand levels of patient adherence, and the range of study designs and methodological challenges involved in measuring adherence and interpreting results. Since antimalarial adherence was reviewed in 2004, there has been a major expansion in the use of artemisinin-based combination therapies (ACTs) in the public sector, as well as initiatives to make them more widely accessible through community health workers and private retailers. These changes and the large number of recent adherence studies raise the need for an updated review on this topic. Objective We conducted a systematic review of studies reporting quantitative results on patient adherence to antimalarials obtained for treatment. Results The 55 studies identified reported extensive variation in patient adherence to antimalarials, with many studies reporting very high adherence (90–100%) and others finding adherence of less than 50%. We identified five overarching approaches to assessing adherence based on the definition of adherence and the methods used to measure it. Overall, there was no clear pattern in adherence results by approach. However, adherence tended to be higher among studies where informed consent was collected at the time of obtaining the drug, where patient consultations were directly observed by research staff, and where a diagnostic test was obtained. Conclusion Variations in reported adherence may reflect factors related to patient characteristics and the nature of their consultation with the provider, as well as methodological variations such as interaction between the research team and patients before and during the treatment. Future studies can benefit from an awareness of the impact of study procedures on adherence outcomes, and the identification of improved measurement methods less dependent on self-report. PMID:24465418

  16. Adherence is a multi-dimensional construct in the POUNDS LOST trial.

    PubMed

    Williamson, Donald A; Anton, Stephen D; Han, Hongmei; Champagne, Catherine M; Allen, Ray; LeBlanc, Eric; Ryan, Donna H; McManus, Katherine; Laranjo, Nancy; Carey, Vincent J; Loria, Catherine M; Bray, George A; Sacks, Frank M

    2010-02-01

    Research on the conceptualization of adherence to treatment has not addressed a key question: Is adherence best defined as being a uni-dimensional or multi-dimensional behavioral construct? The primary aim of this study was to test which of these conceptual models best described adherence to a weight management program. This ancillary study was conducted as a part of the POUNDS LOST trial that tested the efficacy of four dietary macronutrient compositions for promoting weight loss. A sample of 811 overweight/obese adults was recruited across two clinical sites, and each participant was randomly assigned to one of four macronutrient prescriptions: (1) Low fat (20% of energy), average protein (15% of energy); (2) High fat (40%), average protein (15%); (3) Low fat (20%), high protein (25%); (4) High fat (40%), high protein (25%). Throughout the first 6 months of the study, a computer tracking system collected data on eight indicators of adherence. Computer tracking data from the initial 6 months of the intervention were analyzed using exploratory and confirmatory analyses. Two factors (accounting for 66% of the variance) were identified and confirmed: (1) behavioral adherence and (2) dietary adherence. Behavioral adherence did not differ across the four interventions, but prescription of a high fat diet (vs. a low fat diet) was found to be associated with higher levels of dietary adherence. The findings of this study indicated that adherence to a weight management program was best conceptualized as being multi-dimensional, with two dimensions: behavioral and dietary adherence.

  17. Highly Conductive, Stretchable, and Transparent Solid Polymer Electrolyte Membrane

    NASA Astrophysics Data System (ADS)

    He, Ruixuan; Echeverri, Mauricio; Kyu, Thein

    2014-03-01

    With the guidance of ternary phase diagrams, completely amorphous polymer electrolyte membranes (PEM) were successfully prepared by melt processing for lithium-ion battery. The PEM under consideration consisted of poly (ethylene glycol diacrylate) (PEGDA), succinonitrile (SCN) and Lithium bis(trifluoro-methane)sulfonamide (LiTFSI). After UV-crosslinking, the PEM is transparent and light-weight. Addition of SCN plastic crystal affords not only dissociation of the lithium salt, but also plasticization to the crosslinked PEGDA network. Of particular importance is the achievement of room-temperature ionic conductivity of ~10-3 S/cm, which is comparable to that of commercial liquid electrolyte. Higher ionic conductivities were achieved at elevated temperatures or with use of a moderately higher molecular weight of PEGDA. In terms of electrochemical and chemical stability, the PEM exhibited oxidative stability up to 5 V against lithium reference electrode. Stable interface behavior between the PEM and lithium electrode is also seen with ageing time. In the tensile tests, samples containing low molecular weight PEGDA are stiffer, whereas the high molecular weight PEGDA is stretchable up to 80% elongation. Supported by NSF-DMR 1161070.

  18. Thermal Conductance Engineering for High-Speed TES Microcalorimeters

    NASA Astrophysics Data System (ADS)

    Hays-Wehle, J. P.; Schmidt, D. R.; Ullom, J. N.; Swetz, D. S.

    2016-07-01

    Many current and future applications for superconducting transition-edge sensor (TES) microcalorimeters require significantly faster pulse response than is currently available. X-ray spectroscopy experiments at next-generation synchrotron light sources need to successfully capture very large fluxes of photons, while detectors at free-electron laser facilities need pulse response fast enough to match repetition rates of the source. Additionally, neutrino endpoint experiments such as HOLMES need enormous statistics, yet are extremely sensitive to pile-up effects that can distort spectra. These issues can be mitigated only by fast rising and falling edges. To address these needs, we have designed high-speed TES detectors with novel geometric enhancements to increase the thermal conductance of pixels suspended on silicon nitride membranes. This paper shows that the thermal conductivity can be precisely engineered to values spanning over an order of magnitude to achieve fast thermal relaxation times tailored to the relevant applications. Using these pixel prototypes, we demonstrate decay time constants faster than 100 μ s, while still maintaining spectral resolution of 3 eV FWHM at 1.5 keV. This paper also discusses the trade-offs inherent in reducing the pixel time constant, such as increased bias current leading to degradation in energy resolution, and potential modifications to improve performance.

  19. High conductance values in π-folded molecular junctions

    NASA Astrophysics Data System (ADS)

    Carini, Marco; Ruiz, Marta P.; Usabiaga, Imanol; Fernández, José A.; Cocinero, Emilio J.; Melle-Franco, Manuel; Diez-Perez, Ismael; Mateo-Alonso, Aurelio

    2017-05-01

    Folding processes play a crucial role in the development of function in biomacromolecules. Recreating this feature on synthetic systems would not only allow understanding and reproducing biological functions but also developing new functions. This has inspired the development of conformationally ordered synthetic oligomers known as foldamers. Herein, a new family of foldamers, consisting of an increasing number of anthracene units that adopt a folded sigmoidal conformation by a combination of intramolecular hydrogen bonds and aromatic interactions, is reported. Such folding process opens up an efficient through-space charge transport channel across the interacting anthracene moieties. In fact, single-molecule conductance measurements carried out on this series of foldamers, using the scanning tunnelling microscopy-based break-junction technique, reveal exceptionally high conductance values in the order of 10-1 G0 and a low length decay constant of 0.02 Å-1 that exceed the values observed in molecular junctions that make use of through-space charge transport pathways.

  20. High conductance values in π-folded molecular junctions.

    PubMed

    Carini, Marco; Ruiz, Marta P; Usabiaga, Imanol; Fernández, José A; Cocinero, Emilio J; Melle-Franco, Manuel; Diez-Perez, Ismael; Mateo-Alonso, Aurelio

    2017-05-18

    Folding processes play a crucial role in the development of function in biomacromolecules. Recreating this feature on synthetic systems would not only allow understanding and reproducing biological functions but also developing new functions. This has inspired the development of conformationally ordered synthetic oligomers known as foldamers. Herein, a new family of foldamers, consisting of an increasing number of anthracene units that adopt a folded sigmoidal conformation by a combination of intramolecular hydrogen bonds and aromatic interactions, is reported. Such folding process opens up an efficient through-space charge transport channel across the interacting anthracene moieties. In fact, single-molecule conductance measurements carried out on this series of foldamers, using the scanning tunnelling microscopy-based break-junction technique, reveal exceptionally high conductance values in the order of 10(-1) G0 and a low length decay constant of 0.02 Å(-1) that exceed the values observed in molecular junctions that make use of through-space charge transport pathways.

  1. Stable high conductivity ceria/bismuth oxide bilayered electrolytes

    SciTech Connect

    Wachsman, E.D.; Jayaweera, P.; Jiang, N.; Lowe, D.M.; Pound, B.G.

    1997-01-01

    The authors have developed a high conductivity bilayered ceria/bismuth oxide anolyte/electrolyte that uses the Po{sub 2} gradient to obtain stability at the anolyte-electrolyte interface and reduced electronic conduction due to the electrolyte region. Results in terms of solid oxide fuel cell (SOFC) performance and stability are presented. These results include a 90 to 160 mV increase in open-circuit potential, depending on temperature, with the bilayered structure as compared to SOFCs fabricated from a single ceria layer. An open-circuit potential of >1.0 V was obtained at 500 C with the bilayered structure. This increase in open-circuit potential is obtained without any measurable increase in cell resistance and is stable for over 1,400 h of testing, under both open-circuit and maximum power conditions. Moreover, SOFCs fabricated from the bilayered structure result in a 33% greater power density as compared to cells with a single ceria electrolyte layer.

  2. Evaluation of adherence to therapy in patients of chronic kidney disease.

    PubMed

    Sontakke, Smita; Budania, Ritu; Bajait, Chaitali; Jaiswal, Kavita; Pimpalkhute, Sonali

    2015-01-01

    To evaluate adherence to medication and study factors associated with non-adherence in chronic kidney disease (CKD) patients. A prospective, cross-sectional, questionnaire based study was conducted in Nephrology department of a super specialty hospital. Patients above 18 years of age, suffering from CKD from six months or more were interviewed using self-designed, semi-structured questionnaire to get information about adherence to medication, diet restriction and lifestyle modification (n = 150). Morisky medication adherence questionnaire was used to calculate overall adherence. In this higher score indicates poor adherence. Main outcome measures included prevalence of non-adherence and factors associated with the same. Average number of medicines taken by each patient was 8.0+1.612 (mean+SD) per day. Non-adherence to medication schedule was reported in 34% patients. Common causes of non-adherence were high cost (21.3%), complex dosing schedule (20%), fear of adverse effects (16%). Sixty-eight% patients were not aware about importance of taking each medicine. Sixteen% stopped taking medicines due to high cost. Forty-two% suggested that government should adopt measures to provide free medicines to poor patients. In Morisky medication adherence questionnaire high, medium and low adherence was reported in 7.3%, 55.3% and 37.3% of patients, respectively. Moderately positive correlation was observed between poor adherence and number of concurrent illnesses and number of medicines taken. Since majority of patients were not aware about importance of taking each medicine, creating awareness about the same is essential for improving adherence to therapy. Measures to provide free medicines to non-affording patients need to be implemented since high cost was other major cause of non-adherence.

  3. Fibrinogen and thrombin concentrations are critical for fibrin glue adherence in rat high-risk colon anastomoses

    PubMed Central

    Buen, Eliseo Portilla-de; Orozco-Mosqueda, Abel; Leal-Cortés, Caridad; Vázquez-Camacho, Gonzalo; Fuentes-Orozco, Clotilde; Alvarez-Villaseñor, Andrea Socorro; Macías-Amezcua, Michel Dassaejv; González-Ojeda, Alejandro

    2014-01-01

    OBJECTIVE: Fibrin glues have not been consistently successful in preventing the dehiscence of high-risk colonic anastomoses. Fibrinogen and thrombin concentrations in glues determine their ability to function as sealants, healers, and/or adhesives. The objective of the current study was to compare the effects of different concentrations of fibrinogen and thrombin on bursting pressure, leaks, dehiscence, and morphology of high-risk ischemic colonic anastomoses using fibrin glue in rats. METHODS: Colonic anastomoses in adult female Sprague-Dawley rats (weight, 250-350 g) treated with fibrin glue containing different concentrations of fibrinogen and thrombin were evaluated at post-operative day 5. The interventions were low-risk (normal) or high-risk (ischemic) end-to-end colonic anastomoses using polypropylene sutures and topical application of fibrinogen at high (120 mg/mL) or low (40 mg/mL) concentrations and thrombin at high (1000 IU/mL) or low (500 IU/mL) concentrations. RESULTS: Ischemia alone, anastomosis alone, or both together reduced the bursting pressure. Glues containing a low fibrinogen concentration improved this parameter in all cases. High thrombin in combination with low fibrinogen also improved adherence exclusively in low-risk anastomoses. No differences were detected with respect to macroscopic parameters, histopathology, or hydroxyproline content at 5 days post-anastomosis. CONCLUSIONS: Fibrin glue with a low fibrinogen content normalizes the bursting pressure of high-risk ischemic left-colon anastomoses in rats at day 5 after surgery. PMID:24714834

  4. High frequency conductivity of hot electrons in carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Amekpewu, M.; Mensah, S. Y.; Musah, R.; Mensah, N. G.; Abukari, S. S.; Dompreh, K. A.

    2016-05-01

    High frequency conductivity of hot electrons in undoped single walled achiral Carbon Nanotubes (CNTs) under the influence of ac-dc driven fields was considered. We investigated semi-classically Boltzmann's transport equation with and without the presence of the hot electrons' source by deriving the current densities in CNTs. Plots of the normalized current density versus frequency of ac-field revealed an increase in both the minimum and maximum peaks of normalized current density at lower frequencies as a result of a strong injection of hot electrons. The applied ac-field plays a twofold role of suppressing the space-charge instability in CNTs and simultaneously pumping an energy for lower frequency generation and amplification of THz radiations. These have enormous promising applications in very different areas of science and technology.

  5. Secondary emission conductivity of high purity silica fabric

    NASA Technical Reports Server (NTRS)

    Belanger, V. J.; Eagles, A. E.

    1977-01-01

    High purity silica fabrics were proposed for use as a material to control the effects of electrostatic charging of satellites at synchronous altitudes. These materials exhibited very quiet behavior when placed in simulated charging environments as opposed to other dielectrics used for passive thermal control which exhibit varying degrees of electrical arcing. Secondary emission conductivity is proposed as a mechanism for this superior behavior. Design of experiments to measure this phenomena and data taken on silica fabrics are discussed as they relate to electrostatic discharge (ESD) control on geosynchronous orbit spacecraft. Studies include the apparent change in resistivity of the material as a function of the electron beam energy, flux intensity, and the effect of varying electric fields impressed across the material under test.

  6. Using high hydraulic conductivity nodes to simulate seepage lakes.

    PubMed

    Anderson, Mary P; Hunt, Randall J; Krohelski, James T; Chung, Kuopo

    2002-01-01

    In a typical ground water flow model, lakes are represented by specified head nodes requiring that lake levels be known a priori. To remove this limitation, previous researchers assigned high hydraulic conductivity (K) values to nodes that represent a lake, under the assumption that the simulated head at the nodes in the high-K zone accurately reflects lake level. The solution should also produce a constant water level across the lake. We developed a model of a simple hypothetical ground water/lake system to test whether solutions using high-K lake nodes are sensitive to the value of K selected to represent the lake. Results show that the larger the contrast between the K of the aquifer and the K of the lake nodes, the smaller the error tolerance required for the solution to converge. For our test problem, a contrast of three orders of magnitude produced a head difference across the lake of 0.005 m under a regional gradient of the order of 10(-3) m/m, while a contrast of four orders of magnitude produced a head difference of 0.001 m. The high-K method was then used to simulate lake levels in Pretty Lake, Wisconsin. Results for both the hypothetical system and the application to Pretty Lake compared favorably with results using a lake package developed for MODFLOW (Merritt and Konikow 2000). While our results demonstrate that the high-K method accurately simulates lake levels, this method has more cumbersome postprocessing and longer run times than the same problem simulated using the lake package.

  7. Using high hydraulic conductivity nodes to simulate seepage lakes

    USGS Publications Warehouse

    Anderson, Mary P.; Hunt, Randall J.; Krohelski, James T.; Chung, Kuopo

    2002-01-01

    In a typical ground water flow model, lakes are represented by specified head nodes requiring that lake levels be known a priori. To remove this limitation, previous researchers assigned high hydraulic conductivity (K) values to nodes that represent a lake, under the assumption that the simulated head at the nodes in the high-K zone accurately reflects lake level. The solution should also produce a constant water level across the lake. We developed a model of a simple hypothetical ground water/lake system to test whether solutions using high-K lake nodes are sensitive to the value of K selected to represent the lake. Results show that the larger the contrast between the K of the aquifer and the K of the lake nodes, the smaller the error tolerance required for the solution to converge. For our test problem, a contrast of three orders of magnitude produced a head difference across the lake of 0.005 m under a regional gradient of the order of 10−3 m/m, while a contrast of four orders of magnitude produced a head difference of 0.001 m. The high-K method was then used to simulate lake levels in Pretty Lake, Wisconsin. Results for both the hypothetical system and the application to Pretty Lake compared favorably with results using a lake package developed for MODFLOW (Merritt and Konikow 2000). While our results demonstrate that the high-K method accurately simulates lake levels, this method has more cumbersome postprocessing and longer run times than the same problem simulated using the lake package.

  8. Flexible and conductive MXene films and nanocomposites with high capacitance

    PubMed Central

    Ling, Zheng; Ren, Chang E.; Zhao, Meng-Qiang; Yang, Jian; Giammarco, James M.; Qiu, Jieshan; Barsoum, Michel W.; Gogotsi, Yury

    2014-01-01

    MXenes, a new family of 2D materials, combine hydrophilic surfaces with metallic conductivity. Delamination of MXene produces single-layer nanosheets with thickness of about a nanometer and lateral size of the order of micrometers. The high aspect ratio of delaminated MXene renders it promising nanofiller in multifunctional polymer nanocomposites. Herein, Ti3C2Tx MXene was mixed with either a charged polydiallyldimethylammonium chloride (PDDA) or an electrically neutral polyvinyl alcohol (PVA) to produce Ti3C2Tx/polymer composites. The as-fabricated composites are flexible and have electrical conductivities as high as 2.2 × 104 S/m in the case of the Ti3C2Tx/PVA composite film and 2.4 × 105 S/m for pure Ti3C2Tx films. The tensile strength of the Ti3C2Tx/PVA composites was significantly enhanced compared with pure Ti3C2Tx or PVA films. The intercalation and confinement of the polymer between the MXene flakes not only increased flexibility but also enhanced cationic intercalation, offering an impressive volumetric capacitance of ∼530 F/cm3 for MXene/PVA-KOH composite film at 2 mV/s. To our knowledge, this study is a first, but crucial, step in exploring the potential of using MXenes in polymer-based multifunctional nanocomposites for a host of applications, such as structural components, energy storage devices, wearable electronics, electrochemical actuators, and radiofrequency shielding, to name a few. PMID:25389310

  9. Flexible and conductive MXene films and nanocomposites with high capacitance

    DOE PAGES

    Ling, Zheng; Ren, Chang E.; Zhao, Meng-Qiang; ...

    2014-11-11

    MXenes, a new family of 2D materials, combine hydrophilic surfaces with metallic conductivity. Delamination of MXene produces single-layer nanosheets with thickness of about a nanometer and lateral size of the order of micrometers. The high aspect ratio of delaminated MXene renders it promising nanofiller in multifunctional polymer nanocomposites. In this study, Ti3C2Tx MXene was mixed with either a charged polydiallyldimethylammonium chloride (PDDA) or an electrically neutral polyvinyl alcohol (PVA) to produce Ti3C2Tx/polymer composites. The as-fabricated composites are flexible and have electrical conductivities as high as 2.2 × 104 S/m in the case of the Ti3C2Tx/PVA composite film and 2.4 ×more » 105 S/m for pure Ti3C2Tx films. The tensile strength of the Ti3C2Tx/PVA composites was significantly enhanced compared with pure Ti3C2Tx or PVA films. The intercalation and confinement of the polymer between the MXene flakes not only increased flexibility but also enhanced cationic intercalation, offering an impressive volumetric capacitance of ~530 F/cm3 for MXene/PVA-KOH composite film at 2 mV/s. Finally, to our knowledge, this study is a first, but crucial, step in exploring the potential of using MXenes in polymer-based multifunctional nanocomposites for a host of applications, such as structural components, energy storage devices, wearable electronics, electrochemical actuators, and radiofrequency shielding, to name a few.« less

  10. Flexible and conductive MXene films and nanocomposites with high capacitance

    SciTech Connect

    Ling, Zheng; Ren, Chang E.; Zhao, Meng-Qiang; Yang, Jian; Giammarco, James M.; Qiu, Jieshan; Barsoum, Michel W.; Gogotsi, Yury

    2014-11-11

    MXenes, a new family of 2D materials, combine hydrophilic surfaces with metallic conductivity. Delamination of MXene produces single-layer nanosheets with thickness of about a nanometer and lateral size of the order of micrometers. The high aspect ratio of delaminated MXene renders it promising nanofiller in multifunctional polymer nanocomposites. In this study, Ti3C2Tx MXene was mixed with either a charged polydiallyldimethylammonium chloride (PDDA) or an electrically neutral polyvinyl alcohol (PVA) to produce Ti3C2Tx/polymer composites. The as-fabricated composites are flexible and have electrical conductivities as high as 2.2 × 104 S/m in the case of the Ti3C2Tx/PVA composite film and 2.4 × 105 S/m for pure Ti3C2Tx films. The tensile strength of the Ti3C2Tx/PVA composites was significantly enhanced compared with pure Ti3C2Tx or PVA films. The intercalation and confinement of the polymer between the MXene flakes not only increased flexibility but also enhanced cationic intercalation, offering an impressive volumetric capacitance of ~530 F/cm3 for MXene/PVA-KOH composite film at 2 mV/s. Finally, to our knowledge, this study is a first, but crucial, step in exploring the potential of using MXenes in polymer-based multifunctional nanocomposites for a host of applications, such as structural components, energy storage devices, wearable electronics, electrochemical actuators, and radiofrequency shielding, to name a few.

  11. Assessment of adherence to the CONSORT statement for quality of reports on randomized controlled trial abstracts from four high-impact general medical journals.

    PubMed

    Ghimire, Saurav; Kyung, Eunjung; Kang, Wonku; Kim, Eunyoung

    2012-06-07

    The extended Consolidated Standards of Reporting Trials (CONSORT) Statement for Abstracts was developed to improve the quality of reports of randomized controlled trials (RCTs) because readers often base their assessment of a trial solely on the abstract. To date, few data exist regarding whether it has achieved this goal. We evaluated the extent of adherence to the CONSORT for Abstract statement for quality of reports on RCT abstracts by four high-impact general medical journals. A descriptive analysis of published RCT abstracts in The New England Journal of Medicine (NEJM), The Lancet, The Journal of American Medical Association (JAMA), and the British Medical Journal (BMJ) in the year 2010 was conducted by two reviewers, independently extracting data from a MEDLINE/PubMed search. We identified 271 potential RCT abstracts meeting our inclusion criteria. More than half of the abstracts identified the study as randomized in the title (58.7%; 159/271), reported the specific objective/hypothesis (72.7%; 197/271), described participant eligibility criteria with settings for data collection (60.9%; 165/271), detailed the interventions for both groups (90.8%; 246/271), and clearly defined the primary outcome (94.8%; 257/271). However, the methodological quality domains were inadequately reported: allocation concealment (11.8%; 32/271) and details of blinding (21.0%; 57/271). Reporting the primary outcome results for each group was done in 84.1% (228/271). Almost all of the abstracts reported trial registration (99.3%; 269/271), whereas reports of funding and of harm or side effects from the interventions were found in only 47.6% (129/271) and 42.8% (116/271) of the abstracts, respectively. These findings show inconsistencies and non-adherence to the CONSORT for abstract guidelines, especially in the methodological quality domains. Improvements in the quality of RCT reports can be expected by adhering to existing standards and guidelines as expressed by the CONSORT group.

  12. HIV Medication Adherence

    MedlinePlus

    HIV Treatment HIV Medication Adherence (Last updated 3/2/2017; last reviewed 3/2/2017) Key Points Medication adherence means sticking ... exactly as prescribed. Why is adherence to an HIV regimen important? Adherence to an HIV regimen gives ...

  13. Toward nanofluids of ultra-high thermal conductivity.

    PubMed

    Wang, Liqiu; Fan, Jing

    2011-02-18

    The assessment of proposed origins for thermal conductivity enhancement in nanofluids signifies the importance of particle morphology and coupled transport in determining nanofluid heat conduction and thermal conductivity. The success of developing nanofluids of superior conductivity depends thus very much on our understanding and manipulation of the morphology and the coupled transport. Nanofluids with conductivity of upper Hashin-Shtrikman (H-S) bound can be obtained by manipulating particles into an interconnected configuration that disperses the base fluid and thus significantly enhancing the particle-fluid interfacial energy transport. Nanofluids with conductivity higher than the upper H-S bound could also be developed by manipulating the coupled transport among various transport processes, and thus the nature of heat conduction in nanofluids. While the direct contributions of ordered liquid layer and particle Brownian motion to the nanofluid conductivity are negligible, their indirect effects can be significant via their influence on the particle morphology and/or the coupled transport.

  14. Level of adherence and HIV RNA suppression in the current era of Highly Active Antiretroviral Therapy (HAART)

    PubMed Central

    Viswanathan, Shilpa; Detels, Roger; Mehta, Shruti H.; Macatangay, Bernard J.C.; Kirk, Gregory D.; Jacobson, Lisa P.

    2014-01-01

    The need to achieve ≥95% adherence to HAART for treatment effectiveness may be a barrier for universal initiation at early stages of HIV. Using longitudinal data collected from 2006-2011 from cohort studies of MSM (MACS) and IDUs (ALIVE study), we estimated the minimum adherence needed to achieve HIV RNA suppression (<50 copies/mL), defined as the level at which at least 80% were virally suppressed, and the odds of suppression was not significantly different than that observed with ≥95% adherence. In the MACS, ≥80% suppression was observed with 80-84% adherence and the odds ratio for suppression (vs.≥95% adherence) was 1.43 (0.61, 3.33). In the ALIVE study where <35% were on newer drugs, only 71.4% were suppressed among those who reported ≥95% adherence. Although IDUs on older HAART regimens may need to be ≥95% adherent, concerns related to non-adherence may be less of a barrier to initiation of modern HAART regimens. PMID:25342151

  15. Fabrication of highly oriented hexagonal boron nitride nanosheet/elastomer nanocomposites with high thermal conductivity.

    PubMed

    Kuang, Zhiqiao; Chen, Yulong; Lu, Yonglai; Liu, Li; Hu, Shui; Wen, Shipeng; Mao, Yingyan; Zhang, Liqun

    2015-04-08

    A homogeneous dispersion of hexagonal boron nitride nanosheets (BNNSs) in elastomers is obtained by solution compounding methods, and a high orientation of BNNSs is achieved by strong shearing. The composites show high thermal conductivities, especially when BNNS loading exceeds 17.5 vol%, indicating that the material is promising for thermal-management applications which need high thermal conductivity, low dielectric constant, and adequate softness.

  16. Highly Electrically Conducting Glass-Graphene Nanoplatelets Hybrid Coatings.

    PubMed

    Garcia, E; Nistal, A; Khalifa, A; Essa, Y; Martín de la Escalera, F; Osendi, M I; Miranzo, P

    2015-08-19

    Hybrid coatings consisting of a heat resistant Y2O3-Al2O3-SiO2 (YAS) glass containing 2.3 wt % of graphene nanoplatelets (GNPs) were developed by flame spraying homogeneous ceramic powders-GNP granules. Around 40% of the GNPs survived the high spraying temperatures and were distributed along the splat-interfaces, forming a percolated network. These YAS-GNP coatings are potentially interesting in thermal protection systems and electromagnetic interference shields for aerospace applications; therefore silicon carbide (SiC) materials at the forefront of those applications were employed as substrates. Whereas the YAS coatings are nonconductive, the YAS-GNP coatings showed in-plane electrical conductivity (∼10(2) S·m(-1)) for which a low percolation limit (below 3.6 vol %) is inferred. Indentation tests revealed the formation of a highly damaged indentation zone showing multiple shear displacements between adjacent splats probably favored by the graphene sheets location. The indentation radial cracks typically found in brittle glass coatings are not detected in the hybrid coatings that are also more compliant.

  17. Highly Transparent Conducting Nanopaper for Solid State Foldable Electrochromic Devices.

    PubMed

    Kang, Wenbin; Lin, Meng-Fang; Chen, Jingwei; Lee, Pooi See

    2016-12-01

    It is of great challenge to develop a transparent solid state electrochromic device which is foldable at the device level. Such devices require delicate designs of every component to meet the stringent requirements for transparency, foldability, and deformation stability. Meanwhile, nanocellulose, a ubiquitous natural resource, is attracting escalating attention recently for foldable electronics due to its extreme flexibility, excellent mechanical strength, and outstanding transparency. In this article, transparent conductive nanopaper delivering the state-of-the-art electro-optical performance is achieved with a versatile nanopaper transfer method that facilitates junction fusing for high-quality electrodes. The highly compliant nanopaper electrode with excellent electrode quality, foldability, and mechanical robustness suits well for the solid state electrochromic device that maintains good performance through repeated folding, which is impossible for conventional flexible electrodes. A concept of camouflage wearables is demonstrated using gloves with embedded electrochromics. The discussed strategies here for foldable electrochromics serve as a platform technology for futuristic deformable electronics. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Factors associated with medication adherence in school-aged children with asthma.

    PubMed

    Chan, Amy H Y; Stewart, Alistair W; Foster, Juliet M; Mitchell, Edwin A; Camargo, Carlos A; Harrison, Jeff

    2016-01-01

    Adherence to preventive asthma treatment is poor, particularly in children, yet the factors associated with adherence in this age group are not well understood. Adherence was monitored electronically over 6 months in school-aged children who attended a regional emergency department in New Zealand for an asthma exacerbation and were prescribed twice-daily inhaled corticosteroids. Participants completed questionnaires including assessment of family demographics, asthma responsibility and learning style. Multivariable analysis of factors associated with adherence was conducted. 101 children (mean (range) age 8.9 (6-15) years, 51% male) participated. Median (interquartile range) preventer adherence was 30% (17-48%) of prescribed. Four explanatory factors were identified: female sex (+12% adherence), Asian ethnicity (+19% adherence), living in a smaller household (-3.0% adherence per person in the household), and younger age at diagnosis (+2.7% for every younger year of diagnosis) (all p<0.02). In school-aged children attending the emergency department for asthma, males and non-Asian ethnic groups were at high risk for poor inhaled corticosteroid adherence and may benefit most from intervention. Four factors explained a small proportion of adherence behaviour indicating the difficulty in identifying adherence barriers. Further research is recommended in other similar populations.

  19. Factors associated with medication adherence in school-aged children with asthma

    PubMed Central

    Stewart, Alistair W.; Foster, Juliet M.; Mitchell, Edwin A.; Camargo, Carlos A.; Harrison, Jeff

    2016-01-01

    Adherence to preventive asthma treatment is poor, particularly in children, yet the factors associated with adherence in this age group are not well understood. Adherence was monitored electronically over 6 months in school-aged children who attended a regional emergency department in New Zealand for an asthma exacerbation and were prescribed twice-daily inhaled corticosteroids. Participants completed questionnaires including assessment of family demographics, asthma responsibility and learning style. Multivariable analysis of factors associated with adherence was conducted. 101 children (mean (range) age 8.9 (6–15) years, 51% male) participated. Median (interquartile range) preventer adherence was 30% (17–48%) of prescribed. Four explanatory factors were identified: female sex (+12% adherence), Asian ethnicity (+19% adherence), living in a smaller household (−3.0% adherence per person in the household), and younger age at diagnosis (+2.7% for every younger year of diagnosis) (all p<0.02). In school-aged children attending the emergency department for asthma, males and non-Asian ethnic groups were at high risk for poor inhaled corticosteroid adherence and may benefit most from intervention. Four factors explained a small proportion of adherence behaviour indicating the difficulty in identifying adherence barriers. Further research is recommended in other similar populations. PMID:27730181

  20. Suboptimal treatment adherence in bipolar disorder: impact on clinical outcomes and functioning

    PubMed Central

    Montes, Jose Manuel; Maurino, Jorge; de Dios, Consuelo; Medina, Esteban

    2013-01-01

    Background The primary aim of this study was to assess drug treatment adherence in patients with bipolar disorder and to identify factors associated with adherence. The secondary aim was to analyze the impact of suboptimal adherence on clinical and functional outcomes. Methods A cross-sectional study was conducted in a sample of outpatients receiving an oral antipsychotic drug. Medication adherence was assessed combining the 10-item Drug Attitude Inventory, the Morisky Green Adherence Questionnaire, and the Compliance Rating Scale. Logistic regression was used to determine significant variables associated with suboptimal adherence to medication. Results Three hundred and three patients were enrolled into the study. The mean age was 45.9 ± 12.8 years, and 59.7% were females. Sixty-nine percent of patients showed suboptimal adherence. Disease severity and functioning were significantly worse in the suboptimal group than in the adherent group. Multivariate analysis showed depressive polarity of the last acute episode, presence of subsyndromal symptoms, and substance abuse/dependence to be significantly associated with suboptimal treatment adherence (odds ratios 3.41, 2.13, and 1.95, respectively). Conclusion A high prevalence of nonadherence was found in an outpatient sample with bipolar disorder. Identification of factors related to treatment adherence would give clinicians the opportunity to select more adequately patients who are eligible for potential adherence-focused interventions. PMID:23378745

  1. Subcutaneous Interferon β-1a Administration by Electronic Auto-injector is Associated with High Adherence in Patients with Relapsing Remitting Multiple Sclerosis in a Real-life Study

    PubMed Central

    Järvinen, Elina; Multanen, Juha; Atula, Sari

    2017-01-01

    The objective was to investigate adherence measured by an electronic auto-injector device, and self-reported adherence and treatment convenience in subjects with relapsing remitting multiple sclerosis (RRMS), using an electronic auto-injector Rebismart® to self-inject interferon β-1a. Thirty one patients with RRMS using the electronic auto-injector Rebismart® for self-injecting interferon β-1a subcutaneously three times weekly were included in a real-life clinical multicenter study for 24 weeks in Finland. Mean adherence reported by the device and mean self-assessment of adherence were studied. Reasons for missing injections and treatment convenience were assessed. Association between adherence and gender and age were studied. The mean adherence calculated from the device data was 93.5%. The mean self-assessment of adherence was 96.6%. The most common reason for missing an injection was forget-fulness. Adherence (measured by the device) was not changed over time. In the high adherence group there were more females and young patients (<30 years of age). The auto-injector was found to substantially ease the treatment by 90% of the patients. The electronic auto-injector was associated with high adherence to treatment. The device was found to ease the patient’s treatment and it was perceived as easy to use. It is a convenient tool to assess patient’s adherence to treatment. PMID:28286627

  2. Subcutaneous Interferon β-1a Administration by Electronic Auto-injector is Associated with High Adherence in Patients with Relapsing Remitting Multiple Sclerosis in a Real-life Study.

    PubMed

    Järvinen, Elina; Multanen, Juha; Atula, Sari

    2017-02-20

    The objective was to investigate adherence measured by an electronic auto-injector device, and self-reported adherence and treatment convenience in subjects with relapsing remitting multiple sclerosis (RRMS), using an electronic auto-injector Rebismart(®) to self-inject interferon β-1a. Thirty one patients with RRMS using the electronic auto-injector Rebismart(®) for self-injecting interferon β-1a subcutaneously three times weekly were included in a real-life clinical multicenter study for 24 weeks in Finland. Mean adherence reported by the device and mean self-assessment of adherence were studied. Reasons for missing injections and treatment convenience were assessed. Association between adherence and gender and age were studied. The mean adherence calculated from the device data was 93.5%. The mean self-assessment of adherence was 96.6%. The most common reason for missing an injection was forget-fulness. Adherence (measured by the device) was not changed over time. In the high adherence group there were more females and young patients (<30 years of age). The auto-injector was found to substantially ease the treatment by 90% of the patients. The electronic auto-injector was associated with high adherence to treatment. The device was found to ease the patient's treatment and it was perceived as easy to use. It is a convenient tool to assess patient's adherence to treatment.

  3. Scratch-resistant, highly conductive, and high-strength carbon nanotube-based composite yarns.

    PubMed

    Liu, Kai; Sun, Yinghui; Lin, Xiaoyang; Zhou, Ruifeng; Wang, Jiaping; Fan, Shoushan; Jiang, Kaili

    2010-10-26

    High-strength and conductive carbon nanotube (CNT) yarns are very attractive in many potential applications. However, there is a difficulty when simultaneously enhancing the strength and conductivity of CNT yarns. Adding some polymers into CNT yarns to enhance their strength will decrease their conductivity, while treating them in acid or coating them with metal nanoparticles to enhance their conductivity will reduce their strength. To overcome this difficulty, here we report a method to make high-strength and highly conductive CNT-based composite yarns by using a continuous superaligned CNT (SACNT) yarn as a conductive framework and then inserting polyvinyl alcohol (PVA) into the intertube spaces of the framework through PVA/dimethyl sulphoxide solution to enhance the strength of yarns. The as-produced CNT/PVA composite yarns possess very high tensile strengths up to 2.0 GPa and Young's moduli more than 120 GPa, much higher than those of the CNT/PVA yarns reported. The electric conductivity of as-produced composite yarns is as high as 9.2 × 10(4) S/m, comparable to HNO(3)-treated or Au nanoparticle-coated CNT yarns. These composite yarns are flexible, lightweight, scratch-resistant, very stable in the lab environment, and resistant to extremely humid ambient and as a result can be woven into high-strength and heatable fabrics, showing potential applications in flexible heaters, bullet-proof vests, radiation protection suits, and spacesuits.

  4. Plasma formation in water vapour layers in high conductivity liquids

    NASA Astrophysics Data System (ADS)

    Kelsey, C. P.; Schaper, L.; Stalder, K. R.; Graham, W. G.

    2011-10-01

    The vapour layer development stage of relatively low voltage plasmas in conducting solutions has already been well explored. The nature of the discharges formed within the vapour layer however is still largely unexplored. Here we examine the nature of such discharges through a combination of fast imaging and spatially, temporally resolved spectroscopy and electrical characterisation. The experimental setup used is a pin-to-plate discharge configuration with a -350V, 200 μs pulse applied at a repetition rate of 2Hz. A lens, followed by beam splitter allows beams to one Andor ICCD camera to capture images of the plasma emission with a second camera at the exit of a high resolution spectrometer. Through synchronization of the camera images at specified times after plasma ignition (as determined from current-voltage characteristics) they can be correlated with the spectra features. Initial measurements reveal two apparently different plasma formations. Stark broadening of the hydrogen Balmer beta line indicate electron densities of 3 to 5 ×1020 m-3 for plasmas produced early in the voltage pulse and an order of magnitude less for the later plasmas. The vapour layer development stage of relatively low voltage plasmas in conducting solutions has already been well explored. The nature of the discharges formed within the vapour layer however is still largely unexplored. Here we examine the nature of such discharges through a combination of fast imaging and spatially, temporally resolved spectroscopy and electrical characterisation. The experimental setup used is a pin-to-plate discharge configuration with a -350V, 200 μs pulse applied at a repetition rate of 2Hz. A lens, followed by beam splitter allows beams to one Andor ICCD camera to capture images of the plasma emission with a second camera at the exit of a high resolution spectrometer. Through synchronization of the camera images at specified times after plasma ignition (as determined from current

  5. Effectiveness of adherence to lipid lowering therapy on LDL-cholesterol in patients with very high cardiovascular risk: A real-world evidence study in primary care.

    PubMed

    Guglielmi, Valeria; Bellia, Alfonso; Pecchioli, Serena; Della-Morte, David; Parretti, Damiano; Cricelli, Iacopo; Medea, Gerardo; Sbraccia, Paolo; Lauro, Davide; Cricelli, Claudio; Lapi, Francesco

    2017-08-01

    Despite management guidelines advocating statin/ezetimibe use in very high cardiovascular risk (CV) conditions, adherence to this therapy is still suboptimal and LDL-C target attainment unsatisfactory. We aimed to investigate the level of adherence to statin/ezetimibe and LDL-C target achievement rates in an unselected very high CV risk population in primary care setting in Italy. We performed a retrospective population-based study using the Health Search IMS Health Longitudinal Patient Database (HSD), including adult patients at very high CV risk, newly treated with statin, ezetimibe or their combination, with 3 and 6 months of follow-up. Although the large majority of patients had previous major CV events (99.9%), only 61% and 55.14% resulted adherent (Proportion of Days Covered, PDC≥80%) after 3 and 6 months, respectively. High adherence entailed almost a three times higher probability to reach the therapeutic LDL-C target (3 months: OR = 2.26 [95% [CI]: 1.88 to 2.72]; 6-months: OR = 2.74 [95% CI: 2.27 to 3.31]). The odds to treat to LDL-C target was greater for simvastatin-ezetimibe fixed combination, simvastatin, atorvastatin and rosuvastatin, in decreasing order. Finally, poor adherence was slightly more prevalent among patients treated with less effective statins, and at both low and maximal dosage regimens. This population-based study showed that adherence to statin therapy is poor even among patients who have already experienced a CV event. Failure to achieve recommended LDL-C levels appears imputable to the use of moderate doses and low to standard efficacy statins. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Method of forming macro-structured high surface area transparent conductive oxide electrodes

    DOEpatents

    Forman, Arnold J.; Chen, Zhebo; Jaramillo, Thomas F.

    2016-01-05

    A method of forming a high surface area transparent conducting electrode is provided that includes depositing a transparent conducting thin film on a conductive substrate, where the transparent conducting thin film includes transparent conductive particles and a solution-based transparent conducting adhesive layer which serves to coat and bind together the transparent conducting particles, and heat treating the transparent conducting adhesion layer on the conductive substrate, where an increased surface area transparent conducting electrode is formed.

  7. Thermophysical Properties of Polymer Materials with High Thermal Conductivity

    NASA Astrophysics Data System (ADS)

    Lebedev, S. M.; Gefle, O. S.; Dneprovskii, S. N.; Amitov, E. T.

    2015-06-01

    Results of studies on the main thermophysical properties of new thermally conductive polymer materials are presented. It is shown that modification of polymer dielectrics by micron-sized fillers allows thermally conductive materials with thermal conductivity not less than 2 W/(m K) to be produced, which makes it possible to use such materials as cooling elements of various electrical engineering and semiconductor equipment and devices.

  8. Modeling of thermal conductivity in high performing thermoelectric materials

    NASA Astrophysics Data System (ADS)

    Hatzikraniotis, E.; Kyratsi, Th.; Paraskevopoulos, K. M.

    2017-01-01

    The enhanced TE-performance in Mg2Si-Mg2Sn based pseudo-binaries is presented, which is attributed to low thermal conductivity. Sn-Si alloying, reduces the lattice thermal conductivity due to mass fluctuation. Furthermore, miscibility gap in the Sn-Si substitution causes the formation of composites, with Si-rich and Sn-rich phases, which span from mm to nm scale, and these nano-inclusions reduce further lattice thermal conductivity.

  9. Inkjet printed organic electrochemical transistors with highly conducting polymer electrolytes

    NASA Astrophysics Data System (ADS)

    Afonso, Mónica; Morgado, Jorge; Alcácer, Luís

    2016-10-01

    Organic Electrochemical Transistors (OECTs) were fabricated with two kinds of highly conducting polymer electrolytes, one with cations of small dimensions (Li+) and the other with cations of large dimensions (1-ethyl-3-methylimidazolium, EMI+). All OECTs exhibit transconductance values in the millisiemens range. Those with the larger EMI+ cations reach higher transconductance values and the saturated region of their I(V) characteristics extends to drain negative voltages of the order of -2 V without breakdown. These OECTs aim at potential applications for which it is relevant to use a solid polymer electrolyte instead of an aqueous electrolyte, namely, for integration in complex devices or in sensors and transducers where the electrolyte film may act as a membrane to prevent direct contact of the active material (PEDOT:PSS) with the biological media. The choice of electrolytes with cations of disparate sizes aims at assessing the nature (Faradaic or capacitive) of the processes occurring at the electrolyte/channel interface. The results obtained are consistent with a Faradaic-based operation mechanism.

  10. Life cycle assessment of Japanese high-temperature conductive adhesives.

    PubMed

    Andrae, Anders S G; Itsubo, Norihiro; Yamaguchi, Hiroshi; Inaba, Atsushi

    2008-04-15

    The electrically conductive adhesives (ECA) are on the verge of a breakthrough as reliable interconnection materials for electronic components. As the ban of lead (Pb) in the electronics industry becomes a reality, the ECA's could be attractive overall alternatives to high melting point (HMP) Pb-based solder pastes. Environmental life cycle assessment (LCA) was used to estimate trade-offs between the energy use and the potential toxicity of two future types of ECA's and one HMP Pb-based. The probability is around 90% that the overall CO2 emissions from an ECA based on a tin-bismuth alloy are lower than for a silver-epoxy based ECA, whereas the probability is about 80% that the cumulative energy demand would be lower. It is more uncertain whether the tin-bismuth ECA would contribute to less CO2, or consume less energy, than a HMP Pb-based solder paste. Moreover, for the impact categories contributing to the life-cycle impact assessment method based on end point modeling (LIME) damage category of human health, the tin-bismuth ECA shows a 25 times lower score, and a silver-epoxy based ECA shows an 11 times lower score than the HMP Pb-based solder paste. In order to save resources and decrease CO2 emissions it is recommended to increase the collection and recycling of printed board assemblies using silver-epoxy based ECA.

  11. Development of Highly-Conductive Polyelectrolytes for Lithium Batteries

    NASA Technical Reports Server (NTRS)

    Shriver, D. F.; Ratner, M. A.; Vaynman, S.; Annan, K. O.; Snyder, J. F.

    2003-01-01

    Future NASA and Air Force missions require reliable and safe sources of energy with high specific energy and energy density that can provide thousands of charge-discharge cycles at more than 40% depth- of-discharge and that can operate at low temperatures. All solid-state batteries have substantial advantages with respect to stability, energy density, storage fife and cyclability. Among all solid-state batteries, those with flexible polymer electrolytes offer substantial advantages in cell dimensionality and commensurability, low temperature operation and thin film design. The above considerations suggest that lithium-polymer electrolyte systems are promising for high energy density batteries and should be the systems of choice for NASA and US Air Force applications. Polyelectrolytes (single ion conductors) are among most promising avenues for achieving a major breakthrough 'in the applicability of polymer- based electrolyte systems. Their major advantages include unit transference number for the cation, reduced cell polarization, minimal salt precipitation, and favorable electrolyte stability at interfaces. Our research is focused on synthesis, modeling and cell testing of single ion carriers, polyelectrolytes. During the first year of this project we attempted the synthesis of two polyelectrolytes. The synthesis of the first one, the poly(ethyleneoxide methoxy acrylateco-lithium 1,1,2-trifluorobutanesulfonate acrylate, was attempted few times and it was unsuccessful. We followed the synthetic route described by Cowie and Spence. The yield was extremely low and the final product could not be separated from the impurities. The synthesis of this polyelectrolyte is not described in this report. The second polyelectrolyte, comb polysiloxane polyelectrolyte containing oligoether and perfluoroether sidechains, was synthesized in sufficient quantity to study the range of properties such as thermal stability, Li- ion- conductivity and stability toward lithium metal. Also

  12. High conducting oxide--sulfide composite lithium superionic conductor

    DOEpatents

    Liang, Chengdu; Rangasamy, Ezhiylmurugan; Dudney, Nancy J.; Keum, Jong Kahk; Rondinone, Adam Justin

    2017-01-17

    A solid electrolyte for a lithium-sulfur battery includes particles of a lithium ion conducting oxide composition embedded within a lithium ion conducting sulfide composition. The lithium ion conducting oxide composition can be Li.sub.7La.sub.3Zr.sub.2O.sub.12 (LLZO). The lithium ion conducting sulfide composition can be .beta.-Li.sub.3PS.sub.4 (LPS). A lithium ion battery and a method of making a solid electrolyte for a lithium ion battery are also disclosed.

  13. Development of a high conductivity intercalated graphite composite wire

    NASA Astrophysics Data System (ADS)

    Singhal, S. C.

    1982-02-01

    Composite wires previously fabricated by swaging and claimed to possess conductivity equal to or greater than that of copper were analyzed. Intercalation of HOPG crystals with SbF5+HF mixtures was studied to assess the effect of defects in the starting graphite on the final conductivity and also to determine the conductivity as a function of the stage of the compound. Composite wires consisting of copper, aluminum or lead outer sheath and SbF5+HF-or AsF5-intercalated graphite in the core were fabricated by swaging and/or drawing and then analyzed for their electrical conductivity.

  14. Observing versus Predicting: Initial Patterns of Filling Predict Long-Term Adherence More Accurately Than High-Dimensional Modeling Techniques.

    PubMed

    Franklin, Jessica M; Shrank, William H; Lii, Joyce; Krumme, Alexis K; Matlin, Olga S; Brennan, Troyen A; Choudhry, Niteesh K

    2016-02-01

    Despite the proliferation of databases with increasingly rich patient data, prediction of medication adherence remains poor. We proposed and evaluated approaches for improved adherence prediction. We identified Medicare beneficiaries who received prescription drug coverage through CVS Caremark and initiated a statin. A total of 643 variables were identified at baseline from prior claims and linked Census data. In addition, we identified three postbaseline predictors, indicators of adherence to statins during each of the first 3 months of follow-up. We estimated 10 models predicting subsequent adherence, using logistic regression and boosted logistic regression, a nonparametric data-mining technique. Models were also estimated within strata defined by the index days supply. In 77,703 statin initiators, prediction using baseline variables only was poor with maximum cross-validated C-statistics of 0.606 and 0.577 among patients with index supply ≤30 days and >30 days, respectively. Using only indicators of initial statin adherence improved prediction accuracy substantially among patients with shorter initial dispensings (C = 0.827/0.518), and, when combined with investigator-specified variables, prediction accuracy was further improved (C = 0.842/0.596). Observed adherence immediately after initiation predicted future adherence for patients whose initial dispensings were relatively short. © Health Research and Educational Trust.

  15. [Information about the medicines and adherence to high activity antiretroviral treatment in patients with HIV/AIDS in a hospital of Lima, Peru].

    PubMed

    Pacífico, Juana; Gutiérrez, César

    2015-01-01

    Determine the association between the information received on high activity antiretroviral treatment (HAART) and the adherence to this treatment in patients with HIV / AIDS of a hospital of Lima, Peru. Cross-sectional analytical study. Through interviews were applied the questionnaire SIMS (Satisfaction with Information about Medicines Scale) to measure satisfaction with information received about medications and SMAQ (Simplified Medication Adherence Questionnaire) to determine adherence to HAART. By reviewing medical records sociodemographic and clinical data were collected. 364 patients were interviewed. Satisfaction with the information received about drugs was not associated with adherence to HAART (p = 0.611). Factors associated with the satisfaction with information were: female (ORa = 0.52; 95% CI 0.30 to 0.90); level of higher education (ORa = 0.45; 95% CI 0.27 to 0.75) and age (ORa = 1.05; 95% CI 1.02 to 1.08). There were more satisfaction with the information received on the action and drug use compared with information about potential adverse events (48.9% vs. 43.1%; p = 0.0291). Satisfaction with information received about drugs was not associated with adherence to HAART. This satisfaction increases with age and is lower in females and in the degree of higher education. There are desires for further information on the potential adverse reactions to HAART.

  16. High strength-high conductivity Cu--Fe composites produced by powder compaction/mechanical reduction

    DOEpatents

    Verhoeven, John D.; Spitzig, William A.; Gibson, Edwin D.; Anderson, Iver E.

    1991-08-27

    A particulate mixture of Cu and Fe is compacted and mechanically reduced to form an "in-situ" Cu-Fe composite having high strength and high conductivity. Compaction and mechanical reduction of the particulate mixture are carried out at a temperature and time at temperature selected to avoid dissolution of Fe into the Cu matrix particulates to a harmful extent that substantially degrades the conductivity of the Cu-Fe composite.

  17. High strength-high conductivity Cu-Fe composites produced by powder compaction/mechanical reduction

    DOEpatents

    Verhoeven, J.D.; Spitzig, W.A.; Gibson, E.D.; Anderson, I.E.

    1991-08-27

    A particulate mixture of Cu and Fe is compacted and mechanically reduced to form an ''in-situ'' Cu-Fe composite having high strength and high conductivity. Compaction and mechanical reduction of the particulate mixture are carried out at a temperature and time at temperature selected to avoid dissolution of Fe into the Cu matrix particulates to a harmful extent that substantially degrades the conductivity of the Cu-Fe composite. 5 figures.

  18. High carrier concentration p-type transparent conducting oxide films

    DOEpatents

    Yan, Yanfa; Zhang, Shengbai

    2005-06-21

    A p-type transparent conducting oxide film is provided which is consisting essentially of, the transparent conducting oxide and a molecular doping source, the oxide and doping source grown under conditions sufficient to deliver the doping source intact onto the oxide.

  19. Incidence and Predictors of Multiple Fractures Despite High Adherence to Oral Bisphosphonates: A Binational Population-Based Cohort Study.

    PubMed

    Hawley, Samuel; Javaid, M Kassim; Rubin, Katrine H; Judge, Andrew; Arden, Nigel K; Vestergaard, Peter; Eastell, Richard; Diez-Perez, Adolfo; Cooper, Cyrus; Abrahamsen, Bo; Prieto-Alhambra, Daniel

    2016-01-01

    Oral bisphosphonates (BPs) are highly effective in preventing fractures and are recommended first-line therapies for patients with osteoporosis. We identified the incidence and predictors of oral BP treatment failure, defined as the incidence of two or more fractures while on treatment (≥2 FWOT) among users with high adherence. Fractures were considered from 6 months after treatment initiation and up to 6 months after discontinuation. Data from computerized records and pharmacy invoices were obtained from Sistema d'Informació per al Desenvolupament de l'Investigació en Atenció Primària (SIDIAP; Catalonia, Spain) and Danish Health Registries (Denmark) for all incident users of oral BPs in 2006-2007 and 2000-2001, respectively. Fine and Gray survival models using backward-stepwise selection (p-entry 0.049; p- exit 0.10) and accounting for the competing risk of therapy cessation were used to identify predictors of ≥2 FWOT among patients having persisted with treatment ≥6 months with overall medication possession ratio (MPR) ≥80%. Incidence of ≥2 FWOT was 2.4 (95% confidence interval [CI], 1.8 to 3.2) and 1.7 (95% CI, 1.2 to 2.2) per 1000 patient-years (PYs) within Catalonia and Denmark, respectively. Older age was predictive of ≥2 FWOT in both Catalonian and Danish cohorts: subhazard ratio (SHR) = 2.28 (95% CI, 1.11 to 4.68) and SHR = 2.61 (95% CI, 0.98 to 6.95), respectively, for 65 to <80 years; and SHR = 3.19 (95% CI, 1.33 to 7.69) and SHR = 4.88 (95% CI, 1.74 to 13.7), respectively, for ≥80 years. Further significant predictors of ≥2 FWOT identified within only one cohort were dementia, SHR = 4.46 (95% CI, 1.02 to 19.4) (SIDIAP); and history of recent or older fracture, SHR = 3.40 (95% CI, 1.50 to 7.68) and SHR = 2.08 (95% CI: 1.04-4.15), respectively (Denmark). Even among highly adherent users of oral BP therapy, a minority sustain multiple fractures while on treatment. Older age was predictive of increased risk

  20. High and low thermal conductivity of amorphous macromolecules

    NASA Astrophysics Data System (ADS)

    Xie, Xu; Yang, Kexin; Li, Dongyao; Tsai, Tsung-Han; Shin, Jungwoo; Braun, Paul V.; Cahill, David G.

    2017-01-01

    We measure the thermal conductivity, heat capacity and sound velocity of thin films of five polymers, nine polymer salts, and four caged molecules to advance the fundamental understanding of the lower and upper limits to heat conduction in amorphous macromolecules. The thermal conductivities vary by more than one order of magnitude, from 0.06 W m-1K-1 for [6,6]-phenyl-C71-butyric acid methyl ester to 0.67 W m-1K-1 for poly(vinylphosphonic acid calcium salt). Minimum thermal conductivity calculated from the measured sound velocity and effective atomic density is in good agreement with the thermal conductivity of macromolecules with various molecular structures and intermolecular bonding strength.

  1. Electrical Conductivity of HgTe at High Temperatures

    NASA Technical Reports Server (NTRS)

    Li, C.; Lehoczky, S. L.; Su, C.-H.; Scripa, R. N.

    2004-01-01

    The electrical conductivity of HgTe was measured using a rotating magnetic field method from 300 K to the melting point (943 K). A microscopic theory for electrical conduction was used to calculate the expected temperature dependence of the HgTe conductivity. A comparison between the measured and calculated conductivities was used to obtain the estimates of the temperature dependence of Gamma(sub 6)-Gamma(sub 8) energy gap from 300 K to 943 K. The estimated temperature coefficient for the energy gap was comparable to the previous results at lower temperatures (less than or equal to 300 K). A rapid increase in the conductivity just above 300 K and a subsequent decrease at 500 K is attributed to band crossover effects. This paper describes the experimental approach and some of the theoretical calculation details.

  2. Electrical Conductivity of HgTe at High Temperatures

    NASA Technical Reports Server (NTRS)

    Li, C.; Lehoczky, S. L.; Su, C.-H.; Scripa, R. N.

    2004-01-01

    The electrical conductivity of HgTe was measured using a rotating magnetic field method from 300 K to the melting point (943 K). A microscopic theory for electrical conduction was used to calculate the expected temperature dependence of the HgTe conductivity. A comparison between the measured and calculated conductivities was used to obtain the estimates of the temperature dependence of Gamma(sub 6)-Gamma(sub 8) energy gap from 300 K to 943 K. The estimated temperature coefficient for the energy gap was comparable to the previous results at lower temperatures (less than or equal to 300 K). A rapid increase in the conductivity just above 300 K and a subsequent decrease at 500 K is attributed to band crossover effects. This paper describes the experimental approach and some of the theoretical calculation details.

  3. [Adherence to Phase III Cardiac Rehabilitation Programs: A Prospective, Randomized Comparison between a Conventionally Conducted Program and a Tai Chi-Based Program].

    PubMed

    Wieczorrek, G; Weber, U; Wienke, A; Egner, E; Schröder, J; Vogt, A; Müller-Werdan, U; Weber, A; Steighardt, J; Girschick, C; Schlitt, A

    2016-06-01

    In patients with cardiac diseases, lifestyle changes such as an increase in physical activity are recommended to prevent further cardiac events. In Germany this is possible by attending outpatient heart groups. A problem inherent in these programs is the lack of adherence since more than two thirds of patients stop attending cardiac rehabilitation programs after six months. An alternative to the conventional implementation of heart groups is Tai Chi, which was found to improve adherence to cardiac rehabilitation programs in international studies. Patients were randomly assigned to a conventional heart group or a heart group with Tai Chi exercises. At the beginning of the study, a medical history was taken and physical and instrumental tests were carried out, including an assessment of anxiety/depression (HADS questionnaire) and physical well-being (SD-12). Follow-up tests were performed every three months. Patients were 62.6 ± 8.5 years old, the mean BMI was 28.6 ± 62 kg/m(2), and the proportion of women was 29.8 %. The groups were different in terms of age (conventional heart group: 65.0 ± 7.5; Tai Chi group: 59.9 ± 8.9 years). Therefore, age-adjusted analyses were performed in addition to the planned analyses. Regarding the primary endpoint of the study, there was no difference between the groups. After twelve months, 50 % of subjects were active in the Tai Chi group and 48 % in the conventional heart group (odds ratio 0.92, p = 0.891). After adjustment for age by logistic regression, the odds ratio was 0.47 (p = 0.285). Furthermore, both the participation period in weeks (Tai Chi group: 43.3 ± 26.0; conventional group: 45.5 ± 24.2, p = 0.766) and the participation rate (Tai Chi group: 66.8 ± 19.2 % Tai Chi, conventional group: 76.3 ± 16.5 %, p = 0.074) did not differ between the two groups. A further analysis showed a non-significant trend for improvement of anxiety, depression and physical

  4. Transmission eigenvalue distributions in highly conductive molecular junctions

    PubMed Central

    Barr, Joshua D; Stafford, Charles A

    2012-01-01

    Summary Background: The transport through a quantum-scale device may be uniquely characterized by its transmission eigenvalues τn. Recently, highly conductive single-molecule junctions (SMJ) with multiple transport channels (i.e., several τn > 0) have been formed from benzene molecules between Pt electrodes. Transport through these multichannel SMJs is a probe of both the bonding properties at the lead–molecule interface and of the molecular symmetry. Results: We use a many-body theory that properly describes the complementary wave–particle nature of the electron to investigate transport in an ensemble of Pt–benzene–Pt junctions. We utilize an effective-field theory of interacting π-electrons to accurately model the electrostatic influence of the leads, and we develop an ab initio tunneling model to describe the details of the lead–molecule bonding over an ensemble of junction geometries. We also develop a simple decomposition of transmission eigenchannels into molecular resonances based on the isolated resonance approximation, which helps to illustrate the workings of our many-body theory, and facilitates unambiguous interpretation of transmission spectra. Conclusion: We confirm that Pt–benzene–Pt junctions have two dominant transmission channels, with only a small contribution from a third channel with τn << 1. In addition, we demonstrate that the isolated resonance approximation is extremely accurate and determine that transport occurs predominantly via the HOMO orbital in Pt–benzene–Pt junctions. Finally, we show that the transport occurs in a lead–molecule coupling regime where the charge carriers are both particle-like and wave-like simultaneously, requiring a many-body description. PMID:22428095

  5. Teachers' Adherence to Highly Effective Instructional Practices as Related to Graduation Rates in Average-Need School Districts in New York State

    ERIC Educational Resources Information Center

    Yannucci, Michael J.

    2014-01-01

    The purpose of this study was to investigate school administrators' perceptions of teachers' adherence to the highly effective critical attributes of the four domains of Charlotte Danielson's "Framework for Teaching" (Planning and Preparation, The Classroom Environment, Instruction, and Professional Responsibilities) in kindergarten…

  6. Teachers' Adherence to Highly Effective Instructional Practices as Related to Graduation Rates in Average-Need School Districts in New York State

    ERIC Educational Resources Information Center

    Yannucci, Michael J.

    2014-01-01

    The purpose of this study was to investigate school administrators' perceptions of teachers' adherence to the highly effective critical attributes of the four domains of Charlotte Danielson's "Framework for Teaching" (Planning and Preparation, The Classroom Environment, Instruction, and Professional Responsibilities) in kindergarten…

  7. Understanding Dutch practice nurses' adherence to evidence-based smoking cessation guidelines and their needs for web-based adherence support: results from semistructured interviews

    PubMed Central

    de Ruijter, D; Smit, E S; de Vries, H; Goossens, L; Hoving, C

    2017-01-01

    Objectives Practice nurses in general practices suboptimally adhere to smoking cessation guidelines. Since the effectiveness of their smoking cessation support is greatest when full adherence to these guidelines is achieved, interventions need to be developed to improve practice nurses' guideline adherence, for example, by tailoring their content to adherence determinants. However, the sociocognitive determinants explaining adherence have not yet been investigated. Therefore, this qualitative needs assessment aimed to explore practice nurses' current counselling practices, as well as their sociocognitive beliefs related to their smoking cessation guideline adherence and their needs regarding web-based adherence support. Setting Primary care; general practices in the Netherlands. Participants 19 practice nurses, actively involved in smoking cessation counselling. Methods Semistructured individual interviews, based on the I-Change Model and the Diffusion of Innovations Theory, were conducted from May to September 2014. Data were systematically analysed using the Framework Method and considered reliable (κ 0.77; % agreement 99%). Results Respondents felt able to be empathic and collaborative during smoking cessation consultations. They also reported psychological (eg, low self-efficacy to increase patient motivation and arranging adequate follow-up consultations) and practical barriers (eg, outdated information on quit support compensation and a perceived lack of high-quality trainings for practice nurses) to smoking cessation guideline adherence. Most respondents were interested in web-based adherence support to overcome these barriers. Conclusions Sociocognitive determinants influence practice nurses' smoking cessation guideline adherence. To improve their adherence, web-based tailored adherence support can provide practice nurses with personally relevant feedback tailored to individually perceived barriers to smoking cessation guideline adherence. More

  8. Microplate cell-retaining methodology for high-content analysis of individual non-adherent unanchored cells in a population.

    PubMed

    Deutsch, Assaf; Zurgil, Naomi; Hurevich, Ihar; Shafran, Yana; Afrimzon, Elena; Lebovich, Pnina; Deutsch, Mordechai

    2006-12-01

    A high throughput Microtiter plate Cell Retainer (MCR) has been developed to enable, for the first time, high-content, time-dependent analysis of the same single non-adherent and non-anchored cells in a large cell population, while bio-manipulating the cells. The identity of each cell in the investigated population is secured, even during bio-manipulation, by cell retention in a specially designed concave microlens, acting as a picoliter well (PW). The MCR technique combines micro-optical features and microtiter plate methodology. The array of PWs serves as the bottom of a microtiter plate, fitted with a unique flow damper element. The latter enables rapid fluid exchange without dislodging the cells from their original PWs, thus maintaining the cells' identity. Loading cell suspensions and reagents into the MCR is performed by simple pouring, followed by gravitational sedimentation and settling of cells into the PWs. Cell viability and cell division within the MCR were shown to be similar to those obtained under similar conditions in a standard microtiter plate. The efficiency of single cell occupancy in the MCR exceeded 90%. No cell dislodging was observed when comparing images before and after bio-manipulations (rinsing, staining, etc.). The MCR permits the performance of kinetic measurements on an individual cell basis. Data acquisition is governed by software, controlling microscope performance, stage position and image acquisition and analysis. The PW's unique micro-optical features enable rapid, simultaneous signal analysis of each individual cell, bypassing lengthy image analysis.

  9. Potential Dependence of the Conductivity of Highly Oxidized Polythiophenes, Polypyrroles, and Polyaniline: Finite Windows of High Conductivity

    DTIC Science & Technology

    1990-05-16

    protonation/deprotonation mechanism . Conductivity increases by at least 108 upon oxidizing polyani-ine from neutral to maximally conducting, and decreases...reversible, potential dependent changes in conductivity in liquid S02/electrolyte in the apparent absence of a protonation/deprotonation mechanism ...polyaniline is similar in 0.5 M H2SO4 ,1 liquid S02 /electrolyte, and poly(vinyl alchohol )/H 3PO4.nH20.8 However, the positive potential limit in aqueous

  10. Electrical conductivity of rocks at high pressures and temperatures

    NASA Technical Reports Server (NTRS)

    Parkhomenko, E. I.; Bondarenko, A. T.

    1986-01-01

    The results of studies of the electrical conductivity in the most widely distributed types of igneous rocks, at temperatures of up to 1200 C, at atmospheric pressure, and also at temperatures of up to 700 C and at pressures of up to 20,000 kg/sq cm are described. The figures of electrical conductivity, of activaation energy and of the preexponential coefficient are presented and the dependence of these parameters on the petrochemical parameters of the rocks are reviewed. The possible electrical conductivities for the depository, granite and basalt layers of the Earth's crust and of the upper mantle are presented, as well as the electrical conductivity distribution to the depth of 200 to 240 km for different geological structures.

  11. High Thermal Conductive BBL/Graphene Nanocomposite System

    DTIC Science & Technology

    2011-09-02

    properties. Composite materials employing carbon -based materials such as carbon - nanotube (CNT), graphene, and fullerene have been explored. However, at...fraction as low as 0.1 vol %, comparable to those observed in carbon nanotube -based composites1c and a conductivity of 0.1 Sm-1, sufficient for many...in both poly(benzimidazobenzophenanthroline) (BBL) and the carbon sheets of the graphene so that the electrical-conductivity levels of the composites

  12. STABLCOR™: A high conductivity, low CTE printed circuit board

    NASA Astrophysics Data System (ADS)

    Davis, William E.

    2002-01-01

    The power dissipation levels and the size (footprint) of integrated circuit components that are being assembled to printed circuit boards is causing significant thermal problems that require higher thermal conductivity and close matching of coefficient of thermal expansion. This is especially true when using chip scale devices, chip on board assembly and flip chip on board assembly procedures. AMT has developed a unique printed circuit board that has a thermally conductive layer laminated into the board, which has a thermal conductivity of 225 w/m-k and a very low coefficient of thermal expansion. These properties result in a printed circuit board that is thermally conductive and which has a coefficient of thermal expansion that is closely matched to silicon die and ceramic packages. AMT has demonstrated the benefits of this printed circuit board by conducting thermal cycling tests and vibration tests of boards that were populated with surface mount parts and flip chip on board parts. The testing was conducted under SBIR contracts funded by NASA Glenn Research Center. .

  13. Unique high temperature microwave sintering of aluminum nitride based ceramics with high thermal conductivity

    NASA Astrophysics Data System (ADS)

    Xu, Gengfu

    High temperature microwave sintering is one of the most challenging areas in microwave processing of ceramics. In this dissertation, for the first time, stable, controlled "ultra" high temperature (up to 2100°C) microwave sintering was achieved by development of a unique insulation system based on BN/ZrO2 fiber composite powder synthesized by a unique processing route. It uses a system approach to mitigate the tendency of all insulation materials to interfere with specimen coupling. This insulation system allows stable, controlled ultra high microwave sintering and could be modified to microwave process materials with different thermal, dielectric properties with improved properties. In addition, unlike other high temperature microwave insulation schemes that must be replaced after each run, the insulation system is robust enough for repeated use. Using the insulation design, high density and very high thermal conductivity (˜225 W/m·K) AlN ceramics were fabricated much more efficiently (≤6 hours versus 10's to 100's of hours at high temperature) by microwave sintering than by comparable conventional sintering. A detailed data study of densification, grain growth and thermal conductivity in microwave sintered AlN indicated that there were two time regimes in the development of high thermal conductivity AlN and that oxygen removal was more important to the development of high thermal conductivity than removal of the liquid phase sintering phase. While there have been many previous studies examining processing of high thermal conductivity AlN, this was the first study of microwave processing of high thermal conductivity AlN. AlN-TiB2 composites, which had previously only been successfully densified with pressure-assisted techniques such as HIPing or hot pressing, were successfully microwave sintered in this dissertation. The effect of TiB 2 on the densification behavior and thermal, mechanical, and dielectric properties of microwave sintered AlN based composites

  14. Long-Term Adherence to Antiretroviral Treatment and Program Drop-Out in a High-Risk Urban Setting in Sub-Saharan Africa: A Prospective Cohort Study

    PubMed Central

    Unge, Christian; Södergård, Björn; Marrone, Gaetano; Thorson, Anna; Lukhwaro, Abigael; Carter, Jane; Ilako, Festus; Ekström, Anna Mia

    2010-01-01

    Background Seventy percent of urban populations in sub-Saharan Africa live in slums. Sustaining HIV patients in these high-risk and highly mobile settings is a major future challenge. This study seeks to assess program retention and to find determinants for low adherence to antiretroviral treatment (ART) and drop-out from an established HIV/ART program in Kibera, Nairobi, one of Africa's largest informal urban settlements. Methods and Findings A prospective open cohort study of 800 patients was performed at the African Medical Research Foundation (AMREF) clinic in the Kibera slum. Adherence to ART and drop-out from the ART program were independent outcomes. Two different adherence measures were used: (1) “dose adherence” (the proportion of a prescribed dose taken over the past 4 days) and (2) “adherence index” (based on three adherence questions covering dosing, timing and special instructions). Drop-out from the program was calculated based on clinic appointment dates and number of prescribed doses, and a patient was defined as being lost to follow-up if over 90 days had expired since the last prescribed dose. More than one third of patients were non-adherent when all three aspects of adherence – dosing, timing and special instructions – were taken into account. Multivariate logistic regression revealed that not disclosing HIV status, having a low level of education, living below the poverty limit (US$ 2/day) and not having a treatment buddy were significant predictors for non-adherence. Additionally, one quarter of patients dropped out for more than 90 days after the last prescribed ART dose. Not having a treatment buddy was associated with increased risk for drop-out (hazard ratio 1.4, 95% CI = 1.0–1.9). Conclusion These findings point to the dilemma of trying to sustain a growing number of people on life-long ART in conditions where prevailing stigma, poverty and food shortages threatens the long-term success of HIV treatment. PMID:21049045

  15. Multicenter cluster-randomized trial of a multifactorial intervention to improve antihypertensive medication adherence and blood pressure control among patients at high cardiovascular risk (the COM99 study).

    PubMed

    Pladevall, Manel; Brotons, Carlos; Gabriel, Rafael; Arnau, Anna; Suarez, Carmen; de la Figuera, Mariano; Marquez, Emilio; Coca, Antonio; Sobrino, Javier; Divine, George; Heisler, Michele; Williams, L Keoki

    2010-09-21

    Medication nonadherence is common and results in preventable disease complications. This study assessed the effectiveness of a multifactorial intervention to improve both medication adherence and blood pressure control and to reduce cardiovascular events. In this multicenter, cluster-randomized trial, physicians from hospital-based hypertension clinics and primary care centers across Spain were randomized to receive and provide the intervention to their high-risk patients. Eligible patients were ≥ 50 years of age, had uncontrolled hypertension, and had an estimated 10-year cardiovascular risk greater than 30%. Physicians randomized to the intervention group counted patients' pills, designated a family member to support adherence behavior, and provided educational information to patients. The primary outcome was blood pressure control at 6 months. Secondary outcomes included both medication adherence and a composite end point of all-cause mortality and cardiovascular-related hospitalizations. Seventy-nine physicians and 877 patients participated in the trial. The mean duration of follow-up was 39 months. Intervention patients were less likely to have an uncontrolled systolic blood pressure (odds ratio 0.62, 95% confidence interval 0.50 to 0.78) and were more likely to be adherent (odds ratio 1.91, 95% confidence interval 1.19 to 3.05) than control group patients at 6 months. After 5 years, 16% of the patients in the intervention group and 19% in the control group met the composite end point (hazard ratio 0.97, 95% confidence interval 0.67 to 1.39). A multifactorial intervention to improve adherence to antihypertensive medication was effective in improving both adherence and blood pressure control, but it did not appear to improve long-term cardiovascular events.

  16. Antidepressant adherence after psychiatric hospitalization

    PubMed Central

    Zivin, Kara; Ganoczy, Dara; Pfeiffer, Paul N.; Miller, Erin M.; Valenstein, Marcia

    2010-01-01

    Objective Depressed patients discharged from psychiatric hospitalizations face increased risks for adverse outcomes including suicide, yet antidepressant adherence rates during this high-risk period are unknown. Using Veterans Affairs (VA) data, we assessed antidepressant adherence and predictors of poor adherence among depressed veterans following psychiatric hospitalization. Method We identified VA patients nationwide with depressive disorders who had a psychiatric hospitalization between April 1, 1999 and September 30, 2003, received antidepressant medication, and had an outpatient appointment following discharge. We calculated medication possession ratios (MPRs), a measure of medication adherence, within three and six months following discharge. We assessed patient factors associated with having lower levels of adherence (MPRs <0.8) after discharge. Results 20,931 and 23,182 patients met criteria for three and six month MPRs. The mean three month MPR was 0.79 (s.d.=0.37). The mean six month MPR was 0.66 (s.d.=0.40). Patients with poorer adherence were male, younger, non-white, and had a substance abuse disorder, but were less likely to have PTSD or other anxiety disorders. Conclusion Poor antidepressant adherence is common among depressed patients after psychiatric hospitalization. Efforts to improve adherence at this time may be critical in improving the outcomes of these high-risk patients. PMID:19609666

  17. High temperature electrically conducting ceramic heating element and control system

    NASA Technical Reports Server (NTRS)

    Halbach, C. R.; Page, R. J.

    1975-01-01

    Improvements were made in both electrode technology and ceramic conductor quality to increase significantly the lifetime and thermal cycling capability of electrically conducting ceramic heater elements. These elements were operated in vacuum, inert and reducing environments as well as oxidizing atmospheres adding to the versatility of the conducting ceramic as an ohmic heater. Using stabilized zirconia conducting ceramic heater elements, a furnace was fabricated and demonstrated to have excellent thermal response and cycling capability. The furnace was used to melt platinum-20% rhodium alloy (melting point 1904 C) with an isothermal ceramic heating element having a nominal working cavity size of 2.5 cm diameter by 10.0 cm long. The furnace was operated to 1940 C with the isothermal ceramic heating element. The same furnace structure was fitted with a pair of main heater elements to provide axial gradient temperature control over a working cavity length of 17.8 cm.

  18. Estimated Viscosities and Thermal Conductivities of Gases at High Temperatures

    NASA Technical Reports Server (NTRS)

    Svehla, Roger A.

    1962-01-01

    Viscosities and thermal conductivities, suitable for heat-transfer calculations, were estimated for about 200 gases in the ground state from 100 to 5000 K and 1-atmosphere pressure. Free radicals were included, but excited states and ions were not. Calculations for the transport coefficients were based upon the Lennard-Jones (12-6) potential for all gases. This potential was selected because: (1) It is one of the most realistic models available and (2) intermolecular force constants can be estimated from physical properties or by other techniques when experimental data are not available; such methods for estimating force constants are not as readily available for other potentials. When experimental viscosity data were available, they were used to obtain the force constants; otherwise the constants were estimated. These constants were then used to calculate both the viscosities and thermal conductivities tabulated in this report. For thermal conductivities of polyatomic gases an Eucken-type correction was made to correct for exchange between internal and translational energies. Though this correction may be rather poor at low temperatures, it becomes more satisfactory with increasing temperature. It was not possible to obtain force constants from experimental thermal conductivity data except for the inert atoms, because most conductivity data are available at low temperatures only (200 to 400 K), the temperature range where the Eucken correction is probably most in error. However, if the same set of force constants is used for both viscosity and thermal conductivity, there is a large degree of cancellation of error when these properties are used in heat-transfer equations such as the Dittus-Boelter equation. It is therefore concluded that the properties tabulated in this report are suitable for heat-transfer calculations of gaseous systems.

  19. A highly conductive electrolyte for molten oxide fuel cells.

    PubMed

    Belousov, V V; Fedorov, S V

    2017-01-03

    A gas-tight and ductile solid/liquid δ-Bi2O3-0.2 wt% B2O3 electrolyte for molten oxide fuel cells (MOFCs) is developed. The MOFCs are a new class of intermediate temperature fuel cells. The composite, consisting of solid (δ-Bi2O3) and liquid (molten Bi2O3 + B2O3) oxygen ion-conducting phases, demonstrates the promising application as an MOFC electrolyte with the highest oxygen ionic conductivity.

  20. Suboptimal inhaler medication adherence and incorrect technique are common among chronic obstructive pulmonary disease patients.

    PubMed

    Sriram, Krishna B; Percival, Matthew

    2016-02-01

    Patients with chronic obstructive pulmonary disease (COPD) are routinely prescribed one or more inhaled medications. Adherence to inhaler medications and correct inhaler device technique are crucial to successful COPD management. The goals of this study were to estimate adherence and inhaler technique in a cohort of COPD patients. This was an observational study conducted on a sample of 150 COPD patients. Medication adherence was assessed using the Medication Adherence Report Scale (MARS). Inhaler technique was assessed using standardized checklists. Clinical data were collected using a proforma. Of the 150 patients (mean age 70.3 years, 52% male), 58% reported suboptimal adherence (MARS ≤ 24). High adherence to therapy (MARS = 25) was associated with older age (p = 0.001), but not any of the other studied variables. Medication non-adherence was not associated with COPD exacerbations. Errors (≥ 1) in inhaler technique were common across all of the types of inhaler devices reportedly used by patients, with the highest proportion of errors among Turbuhaler users (83%) and the least proportion of errors among Handihaler users (50%). No clinical variables were associated with errors in inhaler technique. Suboptimal adherence and errors in inhaler technique are common among COPD patients. No clinical variables to assist in the prediction of medication non-adherence and poor inhaler technique were identifiable. Consequently, regular assessment of medication adherence and inhaler technique should be incorporated into routine clinical practice to facilitate improved health outcomes among patients with COPD.

  1. ADHERENCE AND QUALITY OF LIFE IN PATIENTS WITH TYPE II DIABETES MELLITUS IN NORTHERN GREECE

    PubMed Central

    Zioga, Efrosini; Kazakos, Kyriakos; Dimopoulos, Evagelos; Koutras, Christos; Marmara, Kalliopi; Marmara, Eleni-Efrosini; Marmaras, Athanasios; Lavdaniti, Maria

    2016-01-01

    Introduction: Adherence as a concept includes various types of health-related behavior. Better medical adherence leads to improved disease control and fewer diabetes–related complications. Quality of life and medication adherence are interrelated. Patients with diabetes who adhere to their treatment can experience an improvement in quality of life and vice versa. Aim: To assess treatment adherence in patients with type II diabetes, as well as the connection between adherence and quality of life. Methodology: A descriptive non-experimental study was conducted in a provincial hospital in Northern Greece. The sample examined was a convenience sample consisting of 108 patients with type II diabetes mellitus. They completed the “Diabetes Self-Care Activities Questionnaire” and SF-36 “Quality of Life Questionnaire”. Results: Participants demonstrated good adherence to diet and blood test / blood glucose test routines, but did not experience high levels of quality of life. The type of treatment affected the adherence to blood tests with a statistically significant difference (p=0,000). Also, marital status affected mental health with a statistically significant difference (p=0,032). The adherence sub scales are correlated with the all domains of quality of life. Conclusions: According to our findings, it is important to plan interventions to enhance adherence to other types of treatment and to help patients to further improve their quality of life. PMID:27698597

  2. Adherence to endocrine therapy in breast cancer adjuvant and prevention settings.

    PubMed

    Chlebowski, Rowan T; Kim, Jisang; Haque, Reina

    2014-04-01

    Adherence to oral endocrine therapy in adjuvant breast cancer settings is a substantial clinical problem. To provide current perspective on adherence to oral endocrine therapies, a comprehensive literature review was conducted. In adjuvant trials, endocrine therapy adherence is relatively high with greater adherence for aromatase inhibitors compared with tamoxifen. In contrast, adherence to adjuvant therapy in clinical practice is relatively poor, with only about 50% of women successfully completing 5-year therapy. Importantly, good adherence (>80% use) has been associated with lower recurrence risk. Endocrine therapy adherence in primary breast cancer prevention trials parallels that seen in adjuvant trials. Factors associated with nonadherence include low recurrence risk perception, side effects, age extremes, medication cost, suboptimal patient-physician communication, and lack of social support. Few prospective studies have evaluated interventions designed to improve adherence. Interventions currently proposed reflect inferences from clinical trial procedures in which clinical contacts are commonly greater than in usual practice settings. In conclusion, for optimal breast cancer outcome, adherence to endocrine therapy must improve. Although general recommendations likely to improve adherence can be made based on clinical trial results and preliminary prospective trial findings, research specifically targeting this issue is needed to establish effective intervention strategies.

  3. ADHERENCE AND QUALITY OF LIFE IN PATIENTS WITH TYPE II DIABETES MELLITUS IN NORTHERN GREECE.

    PubMed

    Zioga, Efrosini; Kazakos, Kyriakos; Dimopoulos, Evagelos; Koutras, Christos; Marmara, Kalliopi; Marmara, Eleni-Efrosini; Marmaras, Athanasios; Lavdaniti, Maria

    2016-07-24

    Adherence as a concept includes various types of health-related behavior. Better medical adherence leads to improved disease control and fewer diabetes-related complications. Quality of life and medication adherence are interrelated. Patients with diabetes who adhere to their treatment can experience an improvement in quality of life and vice versa. To assess treatment adherence in patients with type II diabetes, as well as the connection between adherence and quality of life. A descriptive non-experimental study was conducted in a provincial hospital in Northern Greece. The sample examined was a convenience sample consisting of 108 patients with type II diabetes mellitus. They completed the "Diabetes Self-Care Activities Questionnaire" and SF-36 "Quality of Life Questionnaire". Participants demonstrated good adherence to diet and blood test / blood glucose test routines, but did not experience high levels of quality of life. The type of treatment affected the adherence to blood tests with a statistically significant difference (p=0,000). Also, marital status affected mental health with a statistically significant difference (p=0,032). The adherence sub scales are correlated with the all domains of quality of life. According to our findings, it is important to plan interventions to enhance adherence to other types of treatment and to help patients to further improve their quality of life.

  4. Pill count adherence to prenatal multivitamin/mineral supplement use among low-income women.

    PubMed

    Jasti, Sunitha; Siega-Riz, Anna Maria; Cogswell, Mary E; Hartzema, Abraham G; Bentley, Margaret E

    2005-05-01

    In the United States, the prevalence of third trimester anemia among low-income pregnant women is 29% and has not improved since the 1980s. Although low adherence has been linked to the ineffectiveness of iron supplementation programs, data regarding adherence to supplementation in low-income women are currently lacking. Hence this study was conducted to better understand the factors associated with adherence to the use of iron-containing prenatal multivitamin/mineral supplements among low-income pregnant women. Adherence to supplement use was assessed by pill counts among 244 pregnant women of 867 women who were initially randomized to receive 1 of 3 prenatal supplements. All women received care at a public prenatal clinic. Maternal characteristics associated with adherence were identified using predictive modeling. Women took 74% of supplements as prescribed. Adherence was higher among non-Hispanic white women than among non-Hispanic black women (79% vs. 72%, P high school, unmarried status, nulligravidity, and smoking were positively associated with adherence. In contrast, among the black women, supplement use 3 mo prior to current pregnancy and no loss of appetite were positively associated with adherence. Further research investigating the influence of cultural factors is necessary to better understand adherence to supplement use and the differences in adherence among ethnic groups.

  5. Predictors of Adherence to Relaxation Guided Imagery During Pregnancy in Women with Preterm Labor.

    PubMed

    Chuang, Li-Lan; Liu, Shu-Chen; Chen, Yi-Heng; Lin, Li-Chan

    2015-09-01

    To examine adherence to relaxation guided imagery in women experiencing preterm labor as well as predictors influencing adherence. This study used a longitudinal follow-up approach. Each of the 57 participating women received a mini-MP3 player containing a 13-minute relaxation guided imagery audio program that they were instructed to follow daily until giving birth. Follow-up interviews were conducted weekly. A generalized estimating equation was used to predict adherence. The total adherence rate was 58%. Higher adherence was predicted by the presence of at least a college degree (p=0.006), greater perceived stress (p=0.006), a higher risk of preterm delivery (p<0.001), and greater relaxation effects (p=0.028). Older maternal age was associated with lower adherence (p=0.001). In addition, adherence decreased significantly over time (p<0.001). Adherence was not related to marital status, employment, parity, the baseline level of anxiety, or hospitalization. Pregnant women with a high risk for preterm birth and greater perceived stress showed higher adherence to relaxation guided imagery. For women with a lower adherence to relaxation guided imagery, health care professionals may consider individual preferences regarding relaxation techniques.

  6. Highly conductive self-assembled nanoribbons of coordination polymers.

    PubMed

    Welte, Lorena; Calzolari, Arrigo; Di Felice, Rosa; Zamora, Felix; Gómez-Herrero, Julio

    2010-02-01

    Organic molecules can self-assemble into well-ordered structures, but the conductance of these structures is limited, which is a disadvantage for applications in molecular electronics. Conductivity can be improved by using coordination polymers-in which metal centres are incorporated into a molecular backbone-and such structures have been used as molecular wires by self-assembling them into ordered films on metal surfaces. Here, we report electrically conductive nanoribbons of the coordination polymer [Pt(2)I(S(2)CCH(3))(4)](n) self-assembled on an insulating substrate by direct sublimation of polymer crystals. Conductance atomic force microscopy is used to probe the electrical characteristics of a few polymer chains ( approximately 10) within the nanoribbons. The observed currents exceed those previously sustained in organic and metal-organic molecules assembled on surfaces by several orders of magnitude and over much longer distances. These results, and the results of theoretical calculations based on density functional theory, confirm coordination polymers as candidate materials for applications in molecular electronics.

  7. Affordable, Lightweight, Highly Conductive Polymer Composite Electronic Packaging Structures

    DTIC Science & Technology

    1996-06-01

    matrix composite materials and how various material designs can be utilized in various structural/thermal configurations to produce electronic housings and...conductive polymer composite electronic packaging (i.e., electronic housings and heat sinks). The research will center on predominately polymer

  8. Thermal conductivity of earth materials at high temperatures.

    NASA Technical Reports Server (NTRS)

    Schatz, J. F.; Simmons, G.

    1972-01-01

    The total thermal conductivity (lattice plus radiative) of several important earth materials is measured in the temperature range from 500 to 1900 K. A new technique is used in which a CO2 laser generates a low-frequency temperature wave at one face of a small disk-shaped sample, and an infrared detector views the opposite face to detect the phase of the emerging radiation. Phase data at several frequencies yield the simultaneous determination of the thermal diffusivity and the mean extinction coefficient of the material. The lattice, radiative, and total thermal conductivities are then calculated. Results for single-crystal and polycrystalline forsterite-rich olivines and an enstatite indicate that, even in relatively pure large-grained material, the radiative conductivity does not increase rapidly with temperature. The predicted maximum total thermal conductivity at a depth of 400 km in an olivine mantle is 0.020 cal/cm/sec/deg C, which is less than twice the surface value.

  9. Mobilizing Your Medications: An Automated Medication Reminder Application for Mobile Phones and Hypertension Medication Adherence in a High-Risk Urban Population

    PubMed Central

    Patel, Samir; Jacobus-Kantor, Laura; Marshall, Lorraine; Ritchie, Clark; Kaplinski, Michelle; Khurana, Parvinder S.; Katz, Richard J.

    2013-01-01

    Background Hypertension frequently accompanies diabetes mellitus, worsening prognosis and complicating medical care for patients. Low medication adherence with multiple medications is a major factor in the inadequate achievement of blood pressure treatment goals. Widespread access to mobile phones offers a new opportunity to communicate with patients and enhance disease self-management. Methods We recruited 50 high-risk urban patients with hypertension, who are using at least two prescription medications for hypertension, into an open-label trial using medication reminder software on a mobile phone. Medication adherence was assessed by review of pharmacy refill rates before, during, and after availability of the medication reminder software (pre-activation, activation, and post-activation phase, respectively). Results Forty-eight patients completed the study. All subjects were insured by Medicaid, 96% were African-American, and the majority had diabetes mellitus. The proportion of days covered for each study phase was as follows: pre-activation phase = 0.54, activation phase = 0.58, and post-activation phase = 0.46. A significant difference was found between the activation and post-activation phases (p = .001). The increase in measured adherence between the pre-activation and activation phases approached significance (p =.057). Forty-six patients completed the pre- and post-Morisky medication adherence survey. The median score rose from 2.0 at baseline to 3.0 at study completion (p <.001). Average blood pressure and level of control during study period improved significantly after initiation of the study and remained improved from baseline through the course of the study. The 48 subjects who completed the study reported a high level of satisfaction with the medication reminder application at the final study visit. Conclusions A mobile-phone-based automated medication reminder system shows promise in improving medication adherence and blood pressure in high

  10. [Strategies to improve medication adherence].

    PubMed

    Laufs, U; Böhm, M; Kroemer, H K; Schüssel, K; Griese, N; Schulz, M

    2011-08-01

    Up to 50 % of patients with chronic diseases do not take their medication regularly. Poor adherence to drug therapy is associated with higher morbidity and mortality. A selective literature search using the terms adherence, compliance, concordance, persistence, medication management, and pharmaceutical care was performed. Evidence for improving adherence has been provided for the following principles: individual counselling of patients and care givers, medication management including simplifying dosing and use of combination tablets as well as the use of individual unit doses, e. g. blister cards. The effectiveness has only been shown for the duration of the interventions. The improvement of medication adherence represents an area of research with high impact on outcomes and cost. Measures to improve adherence may be as important as the development of novel therapies. However, prospective clinical evaluations with clinical endpoints are missing especially for the German health care system in order to develop recommendations for clinical practice. Joint efforts of physicians and pharmacists are needed.

  11. Complex conductivity of UTX compounds in high magnetic fields

    SciTech Connect

    Mielke, Charles H; Mcdonald, Ross D; Zapf, Vivien; Altarawneh, M M; Lacerda, A; Alsmadi, A M; Alyones, S; Chang, S; Adak, S; Kothapalli, K; Nakotte, H

    2009-01-01

    We have performed rf-skin depth (complex-conductivity) and magnetoresistance measurements of anti ferromagnetic UTX compounds (T=Ni and X=Al, Ga, Ge) in applied magnetic fields up to 60 T applied parallel to the easy directions. The rf penetration depth was measured by coupling the sample to the inductive element of a resonant tank circuit and then, measuring the shifts in the resonant frequency {Delta}f of the circuit. Shifts in the resonant frequency {Delta}f are known to be proportional to the skin depth of the sample and we find a direct correspondence between the features in {Delta}f and magnetoresistance. Several first-order metamagnetic transitions, which are accompanied by a drastic change in {Delta}f, were observed in these compounds. In general, the complex-conductivity results are consistent with magnetoresistance data.

  12. Complex conductivity of UTX compounds in high magnetic fields

    SciTech Connect

    Lacerda, Alex Hugo; Mielke, Charles H; Mc Donald, Ross D

    2008-01-01

    We have performed Resonance Frequency (RF) skin depth (complex-conductivity) and magnetoresistance measurements of antiferromagnetic UTX compounds (T Ni, and X := AI, Ga, Ge) in applied magnetic fields up to 60 T applied parallel to the easy directions. The RF penetration depth was measured by coupling the sample to the inductive element of a resonant tank circuit and then, measuring the shifts in the resonant frequency {Delta}f of the circuit. Shifts in the resonant frequency {Delta}f are known to be proportional to the skin depth of the sample and we find a direct correspondence between the features in {Delta}f and magnetoresistance. Several first-order metamagnetic transitions, which are accompanied by a drastic change in {Delta}f, were observed in these compounds. In general, the complex-conductivity results are consistent with magnetoresistance data.

  13. Electrical conductivity of noble gases at high pressures.

    PubMed

    Adams, J R; Reinholz, H; Redmer, R; Mintsev, V B; Shilkin, N S; Gryaznov, V K

    2007-09-01

    Theoretical results for the electrical conductivity of noble gas plasmas are presented in comparison with experiment. The composition is determined within a partially ionized plasma model. The conductivity is then calculated using linear response theory, in which the relevant scattering mechanisms of electrons from ions, electrons, and neutral species are taken into account. In particular, the Ramsauer-Townsend effect in electron-neutral scattering is discussed and the importance of a correct description of the Coulomb logarithm in electron scattering by charged particles is shown. A detailed comparison with recent experiments on argon and xenon plasmas is given and results for helium and neon are also revisited. Excellent agreement between theory and experiment is observed, showing considerable improvement upon previous calculations.

  14. Development of Conducting Polymers of High Structural Strength

    DTIC Science & Technology

    1988-05-31

    electrical conductivity measurements over an extended range of temperatures for both pristine and chemically doped samples. Doping of samples by ion...GPC, TGA, DSC , TMA, etc. were charried out. Defects which limit optical nonlinearity have been identified. The most serious of these appears to be...been synthesized. For example, we have prepared copolymers of polythiophene and polyaniline and have characterized the nonlinear optical as well as

  15. High-Voltage Power Switching for a Conducting Tether

    DTIC Science & Technology

    2006-01-01

    emission, and external cross-field conduction. Under an Air Force SBIR contract1, we designed a spacecraft called the ElectroDynamic Delivery Express...of orbital position and spin plane and phase, the EDDE spacecraft can adjust its spin state and all 6 elements of its orbit: altitude, inclination...effort to maintain). The solar arrays are centrifugally stabilized, and track the sun only around the tether axis. II. Current Control System The

  16. Measurement of Thermal Conductivity of Liquids at High Temperature

    NASA Astrophysics Data System (ADS)

    Schick, V.; Remy, B.; Degiovanni, A.; Demeurie, F.; Meulemans, J.; Lombard, P.

    2012-11-01

    The goal purchased in this paper is to implement a pulse method to measure the thermal conductivity of liquid silica glass above 1200°C until 1600°C. A heat flux stimulation controlled in energy and in time is generated on the front face of an experimental cell. The temperature rise is measured on the rear face of this cell face by using a fast cooled infrared camera. The choice of the measurement cell geometry is fundamental to be able to estimate at the same time the thermal diffusivity and the specific heat of the liquid by an inverse technique. The parameters estimation problem takes into account the optimization of the cell wall thickness. The theoretical model used for the inversion takes into account the coupled heat transfer modes (conduction, convection and radiation) that can occur during the experiment, particularly the thermal conductive short-cut through metallic lateral walls of the cell and radiative transfer within the semi-transparent and participating medium. First measurements are performed on a cell filled with water at ambient temperature in order to validate the parameters estimation procedure.

  17. Highly conductive, capacitive, flexible and soft electrodes based on a 3D graphene-nanotube-palladium hybrid and conducting polymer.

    PubMed

    Kim, Hyun-Jun; Randriamahazaka, Hyacinthe; Oh, Il-Kwon

    2014-12-29

    Highly conductive, capacitive and flexible electrodes are fabricated by employing 3D graphene-nanotube-palladium nanostructures and a PEDOT:PSS conducting polymer. The fabricated flexible electrodes, without any additional metallic current collectors, exhibit increased charge mobility and good mechanical properties; they also allow greater access to the electrolyte ions and hence are suitable for flexible energy storage applications. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Current Concepts for PrEP Adherence

    PubMed Central

    Haberer, Jessica E.

    2016-01-01

    Purpose of review This review describes 1) the current understanding of adherence to oral PrEP, 2) methods for adherence measurement, 3) approaches to supporting PrEP adherence, and 4) guidance for defining PrEP adherence goals within the larger context of HIV prevention. Recent findings PrEP adherence has generally been higher in recent trials, open-label extensions, and demonstration projects compared to the initial clinical trials; potential explanations include known PrEP efficacy and different motivations to take PrEP. Recent studies have explored adherence monitoring through electronic pill containers, short message service (SMS), and drug concentrations in hair and dried blood spots. The few PrEP adherence interventions developed to date include combinations of enhanced counseling, feedback of objective adherence measurement, and SMS. Conceptualization of PrEP adherence is evolving. The goal is not 100% adherence indefinitely, as it was in clinical trials. PrEP adherence should be defined with respect to HIV exposure, which varies over time by sexual behavior and use of other prevention strategies. Summary PrEP adherence beyond clinical trials has generally been high enough to achieve reliable HIV prevention. Future efforts to measure and support PrEP adherence should focus on the context of risk for HIV acquisition, accounting for dynamic behaviors and choices among HIV prevention options. PMID:26633638

  19. Highly stretchable and highly conductive metal electrode by very long metal nanowire percolation network.

    PubMed

    Lee, Phillip; Lee, Jinhwan; Lee, Hyungman; Yeo, Junyeob; Hong, Sukjoon; Nam, Koo Hyun; Lee, Dongjin; Lee, Seung Seob; Ko, Seung Hwan

    2012-07-03

    A highly stretchable metal electrode is developed via the solution-processing of very long (>100 μm) metallic nanowires and subsequent percolation network formation via low-temperature nanowelding. The stretchable metal electrode from very long metal nanowires demonstrated high electrical conductivity (~9 ohm sq(-1) ) and mechanical compliance (strain > 460%) at the same time. This method is expected to overcome the performance limitation of the current stretchable electronics such as graphene, carbon nanotubes, and buckled nanoribbons.

  20. Conductive Polymer Binder for High-Tap-Density Nanosilicon Material for Lithium-Ion Battery Negative Electrode Application.

    PubMed

    Zhao, Hui; Wei, Yang; Qiao, Ruimin; Zhu, Chenhui; Zheng, Ziyan; Ling, Min; Jia, Zhe; Bai, Ying; Fu, Yanbao; Lei, Jinglei; Song, Xiangyun; Battaglia, Vincent S; Yang, Wanli; Messersmith, Phillip B; Liu, Gao

    2015-12-09

    High-tap-density silicon nanomaterials are highly desirable as anodes for lithium ion batteries, due to their small surface area and minimum first-cycle loss. However, this material poses formidable challenges to polymeric binder design. Binders adhere on to the small surface area to sustain the drastic volume changes during cycling; also the low porosities and small pore size resulting from this material are detrimental to lithium ion transport. This study introduces a new binder, poly(1-pyrenemethyl methacrylate-co-methacrylic acid) (PPyMAA), for a high-tap-density nanosilicon electrode cycled in a stable manner with a first cycle efficiency of 82%-a value that is further improved to 87% when combined with graphite material. Incorporating the MAA acid functionalities does not change the lowest unoccupied molecular orbital (LUMO) features or lower the adhesion performance of the PPy homopolymer. Our single-molecule force microscopy measurement of PPyMAA reveals similar adhesion strength between polymer binder and anode surface when compared with conventional polymer such as homopolyacrylic acid (PAA), while being electronically conductive. The combined conductivity and adhesion afforded by the MAA and pyrene copolymer results in good cycling performance for the high-tap-density Si electrode.

  1. Highly conductive anion exchange membrane for high power density fuel-cell performance.

    PubMed

    Ren, Xiaoming; Price, Samuel C; Jackson, Aaron C; Pomerantz, Natalie; Beyer, Frederick L

    2014-08-27

    Anion exchange membrane fuel cells (AEMFCs) are regarded as a new generation of fuel cell technology that has the potential to overcome many obstacles of the mainstream proton exchange membrane fuel cells (PEMFCs) in cost, catalyst stability, efficiency, and system size. However, the low ionic conductivity and poor thermal stability of current anion exchange membranes (AEMs) have been the key factors limiting the performance of AEMFCs. In this study, an AEM made of styrenic diblock copolymer with a quaternary ammonium-functionalized hydrophilic block and a cross-linkable hydrophobic block and possessing bicontinuous phases of a hydrophobic network and hydrophilic conduction paths was found to have high ionic conductivity at 98 mS cm(-1) and controlled membrane swelling with water uptake at 117 wt % at 22 °C. Membrane characterizations and fuel cell tests of the new AEM were carried out together with a commercial AEM, Tokuyama A201, for comparison. The high ionic conductivity and water permeability of the new membrane reported in this study is attributed to the reduced torturosity of the ionic conduction paths, while the hydrophobic network maintains the membrane mechanical integrity, preventing excessive water uptake.

  2. New family of lithium salts for highly conductive nonaqueous electrolytes.

    PubMed

    Barbarich, Thomas J; Driscoll, Peter F; Izquierdo, Suzette; Zakharov, Lev N; Incarvito, Christopher D; Rheingold, Arnold L

    2004-11-29

    New lithium salts of weakly coordinating anions were prepared by treating lithium imidazolates or LiN(CH3)2 with 2 equiv of BF(3). They are LiIm(BF3)2, Li 2-MeIm(BF3)2, Li 4-MeIm(BF3)2, LiBenzIm(BF3)2, Li 2-iPrIm(BF3)2, and LiN(CH3)2(BF3)2 (Im=imidazolate, Me=methyl, iPr=isopropyl, BenzIm=benzoimidazolate). The salts were characterized by NMR spectroscopy and mass spectrometry. The structure of LiBenzIm(BF3)2 consists of a dimeric centrosymmetric unit with each lithium atom forming a bridge between the two anions through one fluorine contact to each anion. The structure of a hydrate of LiN(CH3)2(BF3)2 consists of an infinite chain in which each anion chelates two different lithium atoms through Li-F bonds. The conductivities of electrolyte solutions of these salts were measured and are discussed in terms of different ion-pairing modes determined from the solid-state structures, the anion's ability to distribute charge, and solution viscosity. Organic carbonate solutions of LiIm(BF3)2 partially disproportionate at 85 degrees C forming LiBF4, LiBF2[Im(BF3)]2, and Li[(BF3)ImBF2ImBF2Im(BF3)], reaching equilibrium by 3 months at 85 degrees C but not disproportionating at room temperature after 9 months. A mechanism for the formation of these disproportionation products is proposed. The lower conductivity of the 1 M LiIm(BF3)2 solution that has undergone disproportionation is attributed to the formation LiBF4, which is less conductive, and LiBF2[Im(BF3)]2 and Li[(BF3)ImBF2ImBF2Im(BF3)], which increase solution viscosity.

  3. Source conductance scaling for high frequency superconducting quasiparticle receivers

    NASA Technical Reports Server (NTRS)

    Ke, Qing; Feldman, M. J.

    1992-01-01

    It has been suggested that the optimum source conductance G(sub s) for the superconductor-insulator-superconductor (SIS) quasiparticle mixer should have a l/f dependence. This would imply that the critical current density of SIS junctions used for mixing should increase as frequency squared, a stringent constraint on the design of submillimeter SIS mixers, rather than in simple proportion to frequency as previously believed. We have used Tucker's quantum theory of mixing for extensive numerical calculations to determine G(sub s) for an optimized SIS receiver. We find that G(sub s) is very roughly independent of frequency (except for the best junctions at low frequency), and discuss the implications of our results for the design of submillimeter SIS mixers.

  4. Low-temperature thermal conductivity of highly porous copper

    NASA Astrophysics Data System (ADS)

    Tomás, G.; Martins, D.; Cooper, A.; Bonfait, G.

    2015-12-01

    The development and characterization of new materials is of extreme importance in the design of cryogenic apparatus. Recently Versarien® PLC developed a technique capable of producing copper foam with controlled porosity and pore size. Such porous materials could be interesting for cryogenic heat exchangers as well as of special interest in some devices used in microgravit.y environments where a cryogenic liquid is confined by capillarity. In the present work, a system was developed to measure the thermal conductivity by the differential steady-state mode of four copper foam samples with porosity between 58% and 73%, within the temperatures range 20 - 260 K, using a 2 W @ 20 K cryocooler. Our measurements were validated using a copper control sample and by the estimation of the Lorenz number obtained from electrical resistivity measurements at room temperature. With these measurements, the Resistivity Residual Ratio and the tortuosity were obtained.

  5. Development of high performance proton-conducting solid electrolytes

    SciTech Connect

    Linkous, C.A.; Kopitzke, R.W.

    1998-08-01

    This work seeks to improve the efficiency of fuel cell and electrolyzer operation by developing solid electrolytes that will function at higher temperatures. Two objectives were pursued: (1) determine the mechanism of hydrolytic decomposition of aromatic sulfonic acid ionomers, with the intent of identifying structural weaknesses that can be avoided in future materials; and (2) identify new directions in solid electrolyte development. After evaluating a number of aromatic sulfonates, it became apparent that no common mechanism was going to be found; instead, each polymer had its own sequence of degradation steps, involving some combination of desulfonation and/or chain scission. For electrochemical cell operation at temperatures > 200 C, it will be necessary to develop solid electrolytes that do not require sulfonic acids and do not require water to maintain its conductivity mechanism.

  6. High Resolution Thermal Conductivity Measurements of Wide Gap Semiconductors

    NASA Astrophysics Data System (ADS)

    Pollak, Fred

    2002-03-01

    Despite the considerable amount of work on the electronic, optical, and structural properties of wide gap semiconductors (e.g. GaN, AlN, SiC, ZnO) relatively few thermal conductivity (κ)results have been reported. κ is a function of both intrinsic (anharmonic phonon-phonon scattering) and extrinsic (phonon scattering by dislocations, imputities, process-induced damage). Thus κ provides a measure of a material's quality and hence is important from both applied (device heat management, sample quality) and fundamental perspectives. κ can be evaluated by a number of methods including steady-state longitudinal heat flow, modified Angstrom's method, optical pump-probe, laser flash, third harmonic, and scanning thermal microscopy (SThM). With the exception of SThM these approaches require either contacts (destructive) and/or samples thicker than about 100 microns. SThM is essentially nondestructive. flexible, and has a spatial/depth resolution of 2-3 microns. The latter is important for examining low-defect techniques such as LEO in addition to mapping variations in κ across a wafer. This talk will review recent SThM thermal conductivity results on (0001) GaN [LEO (2.0-2.1 W/cm-K), for OMCVD materials sample thickness, n-type doping, grain boundaries, process-induced effects], thick free standing films of (0001) AlN (3.0-3.3 W/cm-K), (0001) SiC wafers including mapping (3.8-3.9 W/cm-K), and the Zn (1.16 W/cm-K) and O (1.02 W/cm-K) faces of bulk (0001) ZnO. Work supported by ONR contract N00014-99-C-0663 administered by Dr. Colin Wood

  7. Adherence management for patients with cancer taking capecitabine: a prospective two-arm cohort study

    PubMed Central

    Krolop, Linda; Ko, Yon-Dschun; Schwindt, Peter Florian; Schumacher, Claudia; Fimmers, Rolf; Jaehde, Ulrich

    2013-01-01

    Objective To develop and evaluate a multiprofessional modular medication management to assure adherence to capecitabine. Methods The study was conducted as a prospective, multicentred observational cohort study. All participants received pharmaceutical care consisting of oral and written information. Daily adherence was defined as percentage of days with correctly administered capecitabine doses and assessed using medication event monitoring. According to their daily adherence during the first cycle, patients were identified as initially non-adherent (<90% adherence) or adherent (≥90% adherence). Initially non-adherent patients received additional adherence support. Results Seventy-three patients with various tumour entities were enrolled, 58 were initially adherent and 15 non-adherent. Median daily adherence of initially non-adherent patients increased from 85.7% to 97.6% during the observation period of six cycles. Throughout all cycles, median daily adherence of initially adherent patients was 100.0%. Daily adherence was not associated with sociodemographic and disease-related factors. No patient was non-persistent. Conclusions An early adherence screening effectively distinguishes between patients adhering and non-adhering to capecitabine. The provision of specific adherence support is associated with enhanced adherence of initially non-adherent patients, whereas initially adherent patients remain adherent for at least six cycles without specific support. Our needs-based approach helps to use available resources for adherence management efficiently. PMID:23872296

  8. Proton conductivity of perfluorosulfonate ionomers at high temperature and high relative humidity

    SciTech Connect

    Matos, Bruno R.; Goulart, Cleverson A.; Santiago, Elisabete I.; Muccillo, R.; Fonseca, Fabio C.

    2014-03-03

    The proton transport properties of Nafion membranes were studied in a wide range of temperature by using an air-tight sample holder able to maintain the sample hydrated at high relative humidity. The proton conductivity of hydrated Nafion membranes continuously increased in the temperature range of 40–180 °C with relative humidity kept at RH = 100%. In the temperature range of 40–90 °C, the proton conductivity followed the Arrhenius-like thermal dependence. The calculated apparent activation energy E{sub a} values are in good agreement with proton transport via the structural diffusion in absorbed water. However, at higher measuring temperatures an upturn of the electrical conductivity was observed to be dependent on the thermal history of the sample.

  9. High Temperature Variable Conductance Heat Pipes for Radioisotope Stirling Systems

    NASA Technical Reports Server (NTRS)

    Tarau, Calin; Walker, Kara L.; Anderson, William G.

    2009-01-01

    In a Stirling radioisotope system, heat must continually be removed from the GPHS modules, to maintain the GPHS modules and surrounding insulation at acceptable temperatures. Normally, the Stirling convertor provides this cooling. If the Stirling convertor stops in the current system, the insulation is designed to spoil, preventing damage to the GPHS, but also ending the mission. An alkali-metal Variable Conductance Heat Pipe (VCHP) is under development to allow multiple stops and restarts of the Stirling convertor. The status of the ongoing effort in developing this technology is presented in this paper. An earlier, preliminary design had a radiator outside the Advanced Stirling Radioisotope Generator (ASRG) casing, used NaK as the working fluid, and had the reservoir located on the cold side adapter flange. The revised design has an internal radiator inside the casing, with the reservoir embedded inside the insulation. A large set of advantages are offered by this new design. In addition to reducing the overall size and mass of the VCHP, simplicity, compactness and easiness in assembling the VCHP with the ASRG are significantly enhanced. Also, the permanently elevated temperatures of the entire VCHP allows the change of the working fluid from a binary compound (NaK) to single compound (Na). The latter, by its properties, allows higher performance and further mass reduction of the system. Preliminary design and analysis shows an acceptable peak temperature of the ASRG case of 140 C while the heat losses caused by the addition of the VCHP are 1.8 W.

  10. High rechargeable sodium metal-conducting polymer batteries

    NASA Astrophysics Data System (ADS)

    Guerfi, A.; Trottier, J.; Gagnon, C.; Barray, F.; Zaghib, K.

    2016-12-01

    Rechargeable lithium batteries accelerated the wireless revolution over the last two decades, and they are now a mature technology for transportation applications in electric vehicles (EV). However, numerous studies have concluded that the proven lithium reserves can hardly absorb the growth in demand. Therefore, sustainable sodium batteries are being considered to overcome the lithium resource shortages that may arise from large-scale application in EVs and stationary energy storage. It is difficult to find a suitable host material for reversible Na-ion storage due to the size of the Na+ ion (0.102 nm) compared to the Li+ ion (0.076 nm). Here we report a low cost and simple sodium technology that is based on a metal-free cathode material. Sodium metal was used as the anode with a conducting polymer cathode and electrochemically tested in a liquid electrolyte. With this technology, a host material for Na intercalation is not required, and because a polymer conductor is used, the size of the Na ion is not an issue.

  11. NMR evidence for the metallic nature of highly conducting polyaniline

    NASA Astrophysics Data System (ADS)

    Kolbert, A. C.; Caldarelli, S.; Thier, K. F.; Sariciftci, N. S.; Cao, Y.; Heeger, A. J.

    1995-01-01

    Polyaniline doped with camphor sulphonic acid (PANI-CSA) has been shown to yield a material that, after casting from solution in meta-cresol, exhibits a temperature-independent magnetic susceptibility [Y. Cao, P. Smith, and A. J. Heeger, Synth. Met. 48, 91 (1992); N. S. Sariciftici, A. J. Heeger, and Y. Cao, Phys. Rev. B 49, 5988 (1994)]. We report recent 13C NMR experiments on uniformly 13enriched PANI-CSA in which the 13C spin-lattice relaxation rates are shown to obey a modified Korringa relation for relaxation via the hyperfine coupling to conduction electrons. This observation of Korringa relaxation in polyaniline provides strong evidence for a metallic state in this material. An estimate is made of the Korringa enhancement factor that provides a measure of the degree of electron-electron correlations present. Two-dimensional spin-exchange experiments are also reported, which show that the 13C NMR signal results from a heterogeneity in the sample over at least a 30-Å distance scale. These results are discussed in terms of the spatial extent of the doping-induced defect.

  12. Ultra-high strength, high conductivity Cu-Ag alloy wires

    SciTech Connect

    Sakai, Y.; Schneider-Muntau, H.J.

    1997-03-01

    A new wire-conductor fabrication method has been developed for Cu-Ag alloys containing 6--24 wt% Ag in which ultra-high strength and high conductivity are obtained by cold drawing combined with intermediate heat treatments. At optimized stages of cold drawing, the wires were given five intermediate heat treatments at 330--430 C for 1--2 hr. This new fabrication method has made it possible to get ultra-high strength at low reduction. The optimized Cu-24 wt% Ag alloy wire with a total drawing strain of {eta} = 5.8 shows an ultimate tensile strength of 1.5 GPa and an electrical conductivity of 65% IACS at room temperature. One advantage of this processing from a manufacturing point of view is that a special technique, such as rebundling, is not required to obtain ultra-high strength, only cold drawing combined with intermediate heat treatments. Also, this fabrication method has made it possible to produce ultra-high strength at low reductions making high-strength, large cross-section conductors a possibility. The wires fabricated by this method are promising candidate conductors for high-field pulse magnets.

  13. Identifying determinants of medication adherence following myocardial infarction using the Theoretical Domains Framework and the Health Action Process Approach.

    PubMed

    Presseau, Justin; Schwalm, J D; Grimshaw, Jeremy M; Witteman, Holly O; Natarajan, Madhu K; Linklater, Stefanie; Sullivan, Katrina; Ivers, Noah M

    2016-12-20

    Despite evidence-based recommendations, adherence with secondary prevention medications post-myocardial infarction (MI) remains low. Taking medication requires behaviour change, and using behavioural theories to identify what factors determine adherence could help to develop novel adherence interventions. Compare the utility of different behaviour theory-based approaches for identifying modifiable determinants of medication adherence post-MI that could be targeted by interventions. Two studies were conducted with patients 0-2, 3-12, 13-24 or 25-36 weeks post-MI. Study 1: 24 patients were interviewed about barriers and facilitators to medication adherence. Interviews were conducted and coded using the Theoretical Domains Framework. Study 2: 201 patients answered a telephone questionnaire assessing Health Action Process Approach constructs to predict intention and medication adherence (MMAS-8). Study 1: domains identified: Beliefs about Consequences, Memory/Attention/Decision Processes, Behavioural Regulation, Social Influences and Social Identity. Study 2: 64, 59, 42 and 58% reported high adherence at 0-2, 3-12, 13-24 and 25-36 weeks. Social Support and Action Planning predicted adherence at all time points, though the relationship between Action Planning and adherence decreased over time. Using two behaviour theory-based approaches provided complimentary findings and identified modifiable factors that could be targeted to help translate Intention into action to improve medication adherence post-MI.

  14. Highly Conducting, Iodine-Doped Fluoroaluminum and Fluorogallium Naphthalocyanine Polymers.

    DTIC Science & Technology

    1982-10-20

    manium (8), alumif (10), and gallium (10) polymers are stable at high tea "Orattes under vacuum and that the silicon polymer is inert to concen...but this did not interfere.) Properties and Structures of Fluoroaluminum and Fluorogallium 2,3-Naphthalo- cyanine The two fluorides are dark green when...Can " ONR Pasadena Detachment Attn: Dr. A# B. Amster, Attn: Dr. R. J. Marcus Chemistry Division 1030 East Green Street China. Lake, California 93555

  15. Older Australians Can Achieve High Adherence to the Mediterranean Diet during a 6 Month Randomised Intervention; Results from the Medley Study.

    PubMed

    Davis, Courtney; Hodgson, Jonathan; Bryan, Janet; Garg, Manohar; Woodman, Richard; Murphy, Karen

    2017-05-24

    Adherence to a Mediterranean diet (MedDiet) is thought to be achievable in non-Mediterranean regions, but this has yet to be investigated. We aimed to determine if an older Australian population could adhere to a MedDiet for six months. We conducted a randomised, parallel dietary intervention trial with two dietary arms: the Mediterranean diet (MedDiet) group and the habitual diet (HabDiet) control group. A 15-point Mediterranean diet adherence score and food and nutrient intakes were estimated from three-day weighed food records collected at baseline, two and four months. Erythrocyte fatty acids, serum carotenoids and urinary metabolites were assessed at baseline, three and six months. We enrolled 166 participants; 152 commenced and 137 completed the study (70 in the MedDiet group, 67 in the HabDiet group). Adherence scores were significantly higher in the MedDiet group at two months (between group difference 2.2, 95% CI 1.3, 2.9) and four months (between group difference 2.6, 95% CI 1.9, 3.3). Consumption of vegetables, fruits, fish, legumes, nuts and olive oil significantly increased in the MedDiet group compared to the control, and discretionary food intake decreased (p < 0.01). Measures of compliance including serum β-carotene, lycopene and erythrocyte monounsaturated fatty acids were significantly higher in the MedDiet group at three and six months (p < 0.05). Our results indicate that a population of older Australians can adopt a Mediterranean diet over a six month period.

  16. Older Australians Can Achieve High Adherence to the Mediterranean Diet during a 6 Month Randomised Intervention; Results from the Medley Study

    PubMed Central

    Davis, Courtney; Hodgson, Jonathan; Bryan, Janet; Garg, Manohar; Woodman, Richard; Murphy, Karen

    2017-01-01

    Adherence to a Mediterranean diet (MedDiet) is thought to be achievable in non-Mediterranean regions, but this has yet to be investigated. We aimed to determine if an older Australian population could adhere to a MedDiet for six months. We conducted a randomised, parallel dietary intervention trial with two dietary arms: the Mediterranean diet (MedDiet) group and the habitual diet (HabDiet) control group. A 15-point Mediterranean diet adherence score and food and nutrient intakes were estimated from three-day weighed food records collected at baseline, two and four months. Erythrocyte fatty acids, serum carotenoids and urinary metabolites were assessed at baseline, three and six months. We enrolled 166 participants; 152 commenced and 137 completed the study (70 in the MedDiet group, 67 in the HabDiet group). Adherence scores were significantly higher in the MedDiet group at two months (between group difference 2.2, 95% CI 1.3, 2.9) and four months (between group difference 2.6, 95% CI 1.9, 3.3). Consumption of vegetables, fruits, fish, legumes, nuts and olive oil significantly increased in the MedDiet group compared to the control, and discretionary food intake decreased (p < 0.01). Measures of compliance including serum β-carotene, lycopene and erythrocyte monounsaturated fatty acids were significantly higher in the MedDiet group at three and six months (p < 0.05). Our results indicate that a population of older Australians can adopt a Mediterranean diet over a six month period. PMID:28538676

  17. High Temperature Variable Conductance Heat Pipes for Radioisotope Stirling Systems

    SciTech Connect

    Tarau, Calin; Walker, Kara L.; Anderson, William G.

    2009-03-16

    In a Stirling radioisotope system, heat must continually be removed from the GPHS modules, to maintain the GPHS modules and surrounding insulation at acceptable temperatures. Normally, the Stirling converter provides this cooling. If the Stirling engine stops in the current system, the insulation is designed to spoil, preventing damage to the GPHS, but also ending the mission. An alkali-metal Variable Conductance Heat Pipe (VCHP) is under development to allow multiple stops and restarts of the Stirling engine. The status of the ongoing effort in developing this technology is presented in this paper. An earlier, preliminary design had a radiator outside the Advanced Stirling Radioisotope Generator (ASRG) casing, used NaK as the working fluid, and had the reservoir located on the cold side adapter flange. The revised design has an internal radiator inside the casing, with the reservoir embedded inside the insulation. A large set of advantages are offered by this new design. In addition to reducing the overall size and mass of the VCHP, simplicity, compactness and easiness in assembling the VCHP with the ASRG are significantly enhanced. Also, the permanently elevated temperatures of the entire VCHP allows the change of the working fluid from a binary compound (NaK) to single compound (Na). The latter, by its properties, allows higher performance and further mass reduction of the system. Preliminary design and analysis shows an acceptable peak temperature of the ASRG case of 140 deg. C while the heat losses caused by the addition of the VCHP are 1.8 W.

  18. Influence of dehydration on the electrical conductivity of epidote and implications for high-conductivity anomalies in subduction zones

    NASA Astrophysics Data System (ADS)

    Hu, Haiying; Dai, Lidong; Li, Heping; Hui, Keshi; Sun, Wenqing

    2017-04-01

    The anomalously high electrical conductivities ( 0.1 to 1 S/m) in deep mantle wedge regions extensively detected by magnetotelluric studies are often associated with the presence of fluids released from the progressive dehydration of subducting slabs. Epidote minerals are the Ca-Al-rich hydrous silicates with huge stability fields exceeding those of amphibole (>70-80 km) in subducting oceanic crust, and they may therefore be transported to greater depth than amphibole and release water to the mantle wedge. In this study, the electrical conductivities of epidote were measured at 0.5-1.5 GPa and 573-1273 K by using a Solartron-1260 Impedance/Gain-Phase Analyzer in a YJ-3000t multianvil pressure within the frequency range of 0.1-106 Hz. The results demonstrate that the influence of pressure on electrical conductivity of epidote is relatively small compared to that of temperature. The dehydration reaction of epidote is observed through the variation of electrical conductivity around 1073 K, and electrical conductivity reaches up to 1 S/m at 1273 K, which can be attributed to aqueous fluid released from epidote dehydration. After sample dehydration, electrical conductivity noticeably decreases by as much as nearly a log unit compared with that before dehydration, presumably due to a combination of the presence of coexisting mineral phases and aqueous fluid derived from the residual epidote. Taking into account the petrological and geothermal structures of subduction zones, it is suggested that the aqueous fluid produced by epidote dehydration could be responsible for the anomalously high conductivities in deep mantle wedges at depths of 70-120 km, particularly in hot subduction zones.

  19. Joint longitudinal data analysis in detecting determinants of CD4 cell count change and adherence to highly active antiretroviral therapy at Felege Hiwot Teaching and Specialized Hospital, North-west Ethiopia (Amhara Region).

    PubMed

    Seyoum, Awoke; Ndlovu, Principal; Temesgen, Zewotir

    2017-03-16

    Adherence and CD4 cell count change measure the progression of the disease in HIV patients after the commencement of HAART. Lack of information about associated factors on adherence to HAART and CD4 cell count reduction is a challenge for the improvement of cells in HIV positive adults. The main objective of adopting joint modeling was to compare separate and joint models of longitudinal repeated measures in identifying long-term predictors of the two longitudinal outcomes: CD4 cell count and adherence to HAART. A longitudinal retrospective cohort study was conducted to examine the joint predictors of CD4 cell count change and adherence to HAART among HIV adult patients enrolled in the first 10 months of the year 2008 and followed-up to June 2012. Joint model was employed to determine joint predictors of two longitudinal response variables over time. Furthermore, the generalized linear mixed effect model had been used for specification of the marginal distribution, conditional to correlated random effect. A total of 792 adult HIV patients were studied to analyze the longitudinal joint model study. The result from this investigation revealed that age, weight, baseline CD4 cell count, ownership of cell phone, visiting times, marital status, residence area and level of disclosure of the disease to family members had significantly affected both outcomes. From the two-way interactions, time * owner of cell phone, time * sex, age * sex, age * level of education as well as time * level of education were significant for CD4 cell count change in the longitudinal data analysis. The multivariate joint model with linear predictor indicates that CD4 cell count change was positively correlated (p ≤ 0.0001) with adherence to HAART. Hence, as adherence to HAART increased, CD4 cell count also increased; and those patients who had significant CD4 cell count change at each visiting time had been encouraged to be good adherents. Joint model analysis was more

  20. Electrical conductivity measurements of aqueous electrolyte solutions at high temperatures and high pressures

    SciTech Connect

    Ho, P.C.; Palmer, D.A.

    1995-02-01

    In aqueous solutions all electrolytes tend to associate at high temperatures (low dielectric constants). Ion association results in the formation of uncharged substrates, which are substantially more volatile than their precursor ions. Thus knowledge of the association constants is important in interpreting the thermodynamics of the partitioning of electrolytes to the vapor phase in a fully speciated approach. Electrical conductance measurements provide a unique window into ionic interactions of solutions at high temperatures and pressures. In this study, the electrical conductivities of dilute (<0.1 molal) aqueous solutions of NaCl (100-600{degrees}C to 300 MPa) and sodium and potassium hydroxides (0-600 and 100-600{degrees}C, respectively, and to 300 MPa) were measured. The results show that the extent of association of Na{sup +} and Cl{sup -} is similar to those for Na{sup +} and K{sup +} with OH{sup -} in solution from subcritical to supercritical conditions.

  1. High frequency electrical conduction block of the pudendal nerve

    NASA Astrophysics Data System (ADS)

    Bhadra, Narendra; Bhadra, Niloy; Kilgore, Kevin; Gustafson, Kenneth J.

    2006-06-01

    A reversible electrical block of the pudendal nerves may provide a valuable method for restoration of urinary voiding in individuals with bladder-sphincter dyssynergia. This study quantified the stimulus parameters and effectiveness of high frequency (HFAC) sinusoidal waveforms on the pudendal nerves to produce block of the external urethral sphincter (EUS). A proximal electrode on the pudendal nerve after its exit from the sciatic notch was used to apply low frequency stimuli to evoke EUS contractions. HFAC at frequencies from 1 to 30 kHz with amplitudes from 1 to 10 V were applied through a conforming tripolar nerve cuff electrode implanted distally. Sphincter responses were recorded with a catheter mounted micro-transducer. A fast onset and reversible motor block was obtained over this range of frequencies. The HFAC block showed three phases: a high onset response, often a period of repetitive firing and usually a steady state of complete or partial block. A complete EUS block was obtained in all animals. The block thresholds showed a linear relationship with frequency. HFAC pudendal nerve stimulation effectively produced a quickly reversible block of evoked urethral sphincter contractions. The HFAC pudendal block could be a valuable tool in the rehabilitation of bladder-sphincter dyssynergia.

  2. A NASA DC-8 conducts high-altitude hurricane studies

    NASA Technical Reports Server (NTRS)

    1998-01-01

    This NASA Dryden Flight Research Center DC-8 takes off from Patrick Air Force Base to pursue its goal of collecting high- altitude information about Atlantic hurricanes and tropical storms. Flying at 35,000 to 40,000 feet, the plane is equipped with instruments to measure the storm's structure, environment and changes in intensity and tracking. The DC-8 is part of the NASA-led Atmospheric Dynamics and Remote Sensing program that includes other government weather researchers and the university community in a study of Atlantic hurricanes and tropical storms. The hurricane study, which lasts through September, is part of NASA's Earth Science enterprise to better understand the total Earth system and the effects of natural and human-induced changes on the global environment.

  3. Electronic monitoring of medication adherence in a 1-year clinical study of 2 dosing regimens of mesalazine for adults in remission with ulcerative colitis.

    PubMed

    Gillespie, David; Hood, Kerenza; Farewell, Daniel; Stenson, Rachel; Probert, Christopher; Hawthorne, A Barney

    2014-01-01

    Adherence to medication is an issue of great importance for patients with ulcerative colitis. Once daily mesalazine seems to be no worse than divided doses in preventing relapse in remitting patients. Although this has been attributed to improved adherence, detailed measures of adherence have been lacking from previous studies. A 1-year substudy was conducted alongside a trial that compared 2 different dosing regimens (once daily versus three times daily) of mesalazine for patients in remission with ulcerative colitis. Participants in the substudy had their adherence monitored electronically using the medication event monitoring system, self-report, and tablet counts. We compared measures, determined factors associated with adherence and associations between adherence and relapse, modeled adherence over time, and explored behavioral aspects. We included 58 participants. Adherence was high across all measures (89.3% self-report, 96.7% tablet counts, and 89.2% medication event monitoring system). Agreement between the measures was poor at times. Adherence according to the medication event monitoring system best distinguished between the participants who relapsed (71.4%) and those who remained in remission (93.4%), although this difference was not statistically discernible at the 5% level. Adherence deteriorated over the study period, with three times daily participants generally less adherent than once-daily participants (odds ratio, 0.03; 95% confidence interval, 0.01-0.08). Adherence was higher on weekdays (odds ratio, 1.47; 95% confidence interval, 1.31-1.65) and around clinic visit dates (odds ratio, 1.43; 95% confidence interval, 1.18-1.72). Simple dosing regimens are preferable to multiple daily dosing regimens. Electronic monitoring of adherence should be used more often in clinical studies. Self-reported adherence and tablet counts may underestimate adherence. Adherence declined over time, and adherence was generally lower and more varied for those allocated

  4. High Power Terahertz Conductive Antenna with Chaotic Electrodes

    NASA Astrophysics Data System (ADS)

    Kim, Christopher; Graber, Benjamin; Wu, Dong Ho

    2015-03-01

    Time domain terahertz spectroscopy (TDTS) is now widely adopted and being used for various purposes, including chemical and material analysis as well as detection of hazardous materials in the laboratories. While there are several different methods available to generate a wideband terahertz pulse for the TDTS, currently a terahertz photoconductive antenna may be the most popular one, as it can produce a wideband terahertz pulse very efficiently. However our experimental investigation indicates that the conventional photoconductive antenna with a pair of parallel electrodes can produce a terahertz pulse at most about 100 micro-Watts. When attempted to produce a higher power terahertz pulse the antenna may experience irrevocable failure. In order to overcome this problem we recently redesigned the photoconductive antenna and implemented electrodes that lead to a chaotic trajectories of charged particles. With the new electrodes we have demonstrated a high power (>2 mW) coherent terahertz beam, and we found that the lifetime of the antenna is also substantially longer than that of the conventional antenna. In this talk I will present our experimental results and disclose some of our new antenna designs. Supported by DTRA and Naval Research Laboratory.

  5. Bond Durability of Carbon-Microfiber-Reinforced Alkali-Activated High-Temperature Cement Adhering to Carbon Steel

    DOE PAGES

    Sugama, Toshifumi; Pyatina, Tatiana

    2017-02-01

    The study aims at evaluating the bond durability of a carbon microfiber (CMF)-reinforced alkali-activating calcium aluminate cement (CAC)/fly ash F (FAF) blend cementitious material adhering to carbon steel (CS) under stresses induced by a 350°C heat-25°Cwater cooling cycle. This cementitious material/CS joint sample was originally prepared in an autoclave at 300°C under a pressure of 8.3 MPa. For comparison, two reference geothermal well cements, Class G modified with silica (G) and calciumaluminum phosphate (CaP), were employed as well reinforced with CMF. In the CAC/FAF blending cement systems, the CAC-derived cementitious reaction products preferentially adhered to CS surfaces, rather than thatmore » of FAF-related reaction products. CMF played a pivotal role in creating tough interfacial bond structure of cement layer adhering to CS. The bond toughness also was supported by the crystalline cementitious reaction products including sodalite, brownmillerite, and hedenbergite as major phases, and aragonite, boehmite, and garronite as minor ones. The brownmillerite as an interfacial reaction product between cement and CS promoted the chemical bonding of the cement to CS, while the other phases served in providing the attractive bonding of the cement to CS. The post-stress-test joint samples revealed the formation of additional brown-millerite, aragonite, and garronite, in particular brownmillerite as the major one. The combination of chemical bonding and self-advancing adherence behavior of the cement was essential for creating a better interfacial bond structure. A similar interfacial bond structure was observed with CaP. The crystalline phase composition of the autoclaved cement revealed apatite, zeolite, and ferrowyllieite as major reaction products, and aragonite and al-katoite as the minor ones. Ferrowyllieite was identified as cement/CS interfacial reaction product contributing to the chemical bond of cement, while the other phases aided in providing the

  6. Chemical vapor deposition of highly adherent diamond coatings onto co-cemented tungsten carbides irradiated by high power diode laser.

    PubMed

    Barletta, M; Rubino, G; Valle, R; Polini, R

    2012-02-01

    The present investigation deals with the definition of a new eco-friendly alternative to pretreat Co-cemented tungsten carbide (WC-Co) substrates before diamond deposition by hot filament chemical vapor deposition (HFCVD). In particular, WC-5.8 wt %Co substrates were submitted to a thermal treatment by a continuous wave-high power diode laser to reduce surface Co concentration and promote the reconstruction of the WC grains. Laser pretreatments were performed both in N(2) and Ar atmosphere to prevent substrate oxidation. Diamond coatings were deposited onto the laser pretreated substrates by HFCVD. For comparative purpose, diamond coatings were also deposited on WC-5.8 wt %Co substrates chemically etched by the well-known two-step pretreatment employing Murakami's reagent and Caro's acid. Surface morphology, microstructure, and chemical composition of the WC-5.8 wt %Co substrates after the different pretreatments and the deposition of diamond coatings were assessed by surface profiler, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction analyses. Wear performance of the diamond coatings was checked by dry sliding linear reciprocating tribological tests. The worn volume of the diamond coatings deposited on the laser pretreated substrates was always found lower than the one measured on the chemically etched substrates, with the N(2) atmosphere being particularly promising.

  7. Highly conductive ionic liquids toward high-performance space-lubricating greases.

    PubMed

    Fan, Xiaoqiang; Wang, Liping

    2014-08-27

    Although ionic liquids (ILs) as a class of promising materials have a wide range of applications due to the excellent properties, their potential as space lubricants has been not systematically explored. Here two kinds of conductive alkyl imidazolium ILs greases were prepared using 1-hexyl-3-methylimidazolium tetrafluoroborate (LB106) and 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl) amide (L-F106) as base oil and the polytetrafluoroethylene (PTFE) as thickener, with multiple-alkylated cyclopentane grease (MACs) as a comparison. Their chemical composition and tribological properties were investigated in detail under simulated space environment which is composed of high vacuum, high temperature and irradiation. Results show that the high conductive ILs greases not only possess good adaptive abilities to space environment and thermal stability but also provide excellent friction reducing and antiwear behaviors as well as high load carrying capacities. The unique physicochemical properties are attributed to a combination of special anions and cations, the excellent tribological properties are strongly dependent on a boundary protective film on the rubbing surfaces.

  8. Extremely high thermal conductivity anisotropy of double-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Ma, Zhaoji; Guo, Zhengrong; Zhang, Hongwei; Chang, Tienchong

    2017-06-01

    Based on molecular dynamics simulations, we reveal that double-walled carbon nanotubes can possess an extremely high anisotropy ratio of radial to axial thermal conductivities. The mechanism is basically the same as that for the high thermal conductivity anisotropy of graphene layers - the in-plane strong sp2 bonds lead to a very high intralayer thermal conductivity while the weak van der Waals interactions to a very low interlayer thermal conductivity. However, different from flat graphene layers, the tubular structures of carbon nanotubes result in a diameter dependent thermal conductivity. The smaller the diameter, the larger the axial thermal conductivity but the smaller the radial thermal conductivity. As a result, a DWCNT with a small diameter may have an anisotropy ratio of thermal conductivity significantly higher than that for graphene layers. The extremely high thermal conductivity anisotropy allows DWCNTs to be a promising candidate for thermal management materials.

  9. Combining Proximal and Penetrating Soil Electrical Conductivity Sensors for High Resolution Digital Soil Mapping

    USDA-ARS?s Scientific Manuscript database

    Proximal ground conductivity sensors produce high spatial resolution maps that integrate the bulk electrical conductivity (ECa) of the soil profile. Variability in conductivity maps must either be inverted to profile conductivity, or be directly calibrated to profile properties for meaningful interp...

  10. Achieving high strength and high electrical conductivity in Ag/Cu multilayers

    NASA Astrophysics Data System (ADS)

    Wei, M. Z.; Xu, L. J.; Shi, J.; Pan, G. J.; Cao, Z. H.; Meng, X. K.

    2015-01-01

    In this work, we investigated the microstructure evolution of Ag/Cu multilayers and its influences on the hardness and electric resistivity with individual layer thickness (h) ranging from 3 to 50 nm. The hardness increases with the decreasing h in the range of 5-20 nm. The barrier to dislocation transmission by stacking faults, twin boundaries, and interfaces leads to hardness enhancement. Simultaneously, in order to get high conductivity, the strong textures in-layers were induced to form for reducing the amount of grain boundaries. The resistivity keeps low even when h decreases to 10 nm. Furthermore, we developed a facile model to evaluate the comprehensive property of Ag/Cu multilayers—the results indicate that the best combination of strength and conductivity occurs when h = 10 nm.

  11. High-strength high-conductivity Cu-Nb microcomposite sheet fabricated via multiple roll bonding

    NASA Astrophysics Data System (ADS)

    Jha, S. C.; Delagi, R. G.; Forster, J. A.; Krotz, P. D.

    1993-01-01

    Copper-niobium microcomposites are a new class of high-strength high-conductivity materials that have attractive properties for room- and elevated-temperature applications. Since Nb has little solid solubility in Cu, addition of Nb to Cu does not affect its conductivity. Copper-niobium microcomposites are melted and cast so that the microstructure of cast Cu-Nb ingots consists of 1-to 10 μm Nb dendrites uniformly distributed within the copper matrix. Extensive wire drawing with a true processing strain ( η > 12) of Cu-Nb alloy leads to refinement and elongation of Nb dendrites into 1-to 10 nm-thick filaments. The presence of such fine Nb filaments causes a significant increase in the strength of Cu-Nb wires. The tensile strength of heavily drawn Cu-Nb wires was determined to be significantly higher than the values predicted by the rule of mixtures. This article reports the fabrication of high-strength Cu-Nb micro-composite sheet by multiple roll bonding. It is difficult and impractical to attain high processing strains ( η > 3) by simple cold rolling. In most practical cold-rolling operation, the thickness reduction does not exceed 90 pct ( η ≅ 2). Therefore, innovative processing is required to generate high strength in Cu-Nb microcomposite sheet. Multiple roll bonding of Cu-Nb has been utilized to store high processing strain ( η > 10) in the material and refine the Nb particle size within the copper matrix. This article describes the microstructure, mechanical properties, and thermal stability of roll-bonded Cu-Nb microcomposite sheet.

  12. Novel high refractive index, thermally conductive additives for high brightness white LEDs

    NASA Astrophysics Data System (ADS)

    Hutchison, Richard Stephen

    In prior works the inclusion of nanoparticle fillers has typically been shown to increase the thermal conductivity or refractive index of polymer nanocomposites separately. High refractive index zirconia nanoparticles have already proved their merit in increasing the optical efficiency of encapsulated light emitting diodes. However, the thermal properties of zirconia-silicone nanocomposites have yet to be investigated. While phosphor-converted light emitting diodes are at the forefront of solid-state lighting technologies for producing white light, they are plagued by efficiency losses due to excessive heating at the semiconductor die and in and around the phosphor particles, as well as photon scattering losses in the phosphor layer. It would then be of great interest if the high refractive index nanoparticles were found to both be capable of increasing the refractive index, thus reducing the optical scattering, and also the thermal conductivity, channeling more heat away from the LED die and phosphors, mitigating efficiency losses from heat. Thermal conductance measurements on unfilled and nanoparticle loaded silicone samples were conducted to quantify the effect of the zirconia nanoparticle loading on silicone nanocomposite thermal conductivity. An increase in thermal conductivity from 0.27 W/mK to 0.49 W/mK from base silicone to silicone with 33.5 wt% zirconia nanoparticles was observed. This trend closely mirrored a basic rule of mixtures prediction, implying a further enhancement in thermal conductivity could be achieved at higher nanoparticle loadings. The optical properties of transparency and light extraction efficiency of these composites were also investigated. While overall the zirconia nanocomposite showed good transparency, there was a slight decrease at the shorter wavelengths with increasing zirconia content. For longer wavelength LEDs, such as green or red, this might not matter, but phosphor-converted white LEDs use a blue LED as the photon source

  13. Cervical cancer screening practices, knowledge of screening and risk, and highly active antiretroviral therapy adherence among women living with human immunodeficiency virus in Lima, Peru.

    PubMed

    Delgado, Jeanne R; Menacho, Luis; Segura, Eddy R; Roman, Fernando; Cabello, Robinson

    2017-03-01

    Cervical cancer (CC) is the leading cause of cancer death among Peruvian women. Awareness shown by women living with HIV (WLHIV) of their increased risk and Papanicoloau (Pap) smear frequency is understudied, particularly in Peru. We assessed the uptake of guidelines-based CC screening practices and its associations with two predictors, knowledge of CC screening and risk and highly active antiretroviral therapy (HAART) adherence, among WLHIV. Collected by self-administered questionnaires from 2014 to 2016, we analyzed the data of 71 WLHIV. Most WLHIV (77.5%, n = 55/71) were overdue to CC screening by not having a Pap smear within the prior 12 months. WLHIV who had on-time Pap smears had a higher median composite 'knowledge' score of 3.0 ([interquartile range] 1.5-4) compared to 2.0 (IQR 1-3) for overdue WLHIV. On-time and overdue WLHIV had the same median composite 'HAART adherence' score of 3.0 (IQR 2-4). Bivariate analysis found no association between knowledge nor adherence with on-time Pap smears. Although on-time WLHIV were more knowledgeable about CC screening and risk, overall CC screening uptake was poor. Larger studies of this population are needed to assess the educational, social, and structural barriers contributing to this low prevalence of screening.

  14. High-yield and phylogenetically robust methods of DNA recovery for analysis of microbial biofilms adherent to plant biomass in the herbivore gut.

    PubMed

    Rosewarne, Carly P; Pope, Phillip B; Denman, Stuart E; McSweeney, Christopher S; O'Cuiv, Paraic; Morrison, Mark

    2011-02-01

    Recent studies have shown the microbial biofilms adherent to plant biomass in the gastrointestinal tracts of humans and other herbivores are quite different to planktonic populations. If these biofilm communities are to be properly characterized by metagenomics methods, then the microbial desorption methods used must ensure the phylogenetic diversity and genetic potential recovered is biologically valid. To that end, we describe here two different methods for desorbing microbes tightly adherent to plant biomass; and used PCR-DGGE analyses of the Bacteria and Archaea rrs genes to show both these desorption methods were effective in recovering the adherent microbial biofilm with no apparent biases in microbe recovery. We also present a derivation of the "repeated bead beating and column (RBB+C) purification" method of DNA extraction that results in the recovery of high molecular weight DNA. These DNA samples can be fragmented and size fractionated by sucrose density gradient centrifugation, bypassing the use of gel-plug lysis and pulsed-field gel electrophoresis separation of DNA for metagenomic library constructions.

  15. The use of cell phone reminder calls for assisting HIV-infected adolescents and young adults to adhere to highly active antiretroviral therapy: a pilot study.

    PubMed

    Puccio, Joseph A; Belzer, Marvin; Olson, Johanna; Martinez, Miguel; Salata, Cathy; Tucker, Diane; Tanaka, Diane

    2006-06-01

    Long-term medication regimen adherence is challenging in all populations, but in the HIV-infected adolescent population the frequency of poverty, homelessness, substance abuse, and mental illness make highly active antiretroviral therapy (HAART) adherence even more challenging. In 2003, we developed a pilot program for HIV-infected adolescents and young adults between the ages of 16 and 24 who were either going to begin a HAART regimen for the first time or begin a new HAART regimen. Participants received a free cell phone with a local service plan for approximately 6 months. Participants received phone call reminders for 12 weeks. Call frequency was tapered at 4-week intervals. Patients were assessed at 4-week intervals to determine the perceived intrusiveness or helpfulness of receiving calls, and missed medication doses. Eight consecutive patients were recruited for the study, and five were able to complete it through the 24 weeks. Most participants found the calls to be helpful and the level of intrusion into their daily lives acceptable. Using cell phone reminders to assist patients does not require an extensive amount of daily staff time. Tapering calls rapidly over 3 months, followed by discontinuation of calls provided inadequate support for subjects, especially those with significant psychosocial issues such as substance abuse. Use of cell phone reminders to assist adolescents adhere with HIV medications was practical and acceptable to pilot study participants. Viral suppression waned for all but two patients after termination of cell phone reminders and suggests that a 12-week intervention was not adequate for most subjects. Larger prospective studies of cell phone observation of therapy will be needed to determine if this intervention can improve long-term adherence and health outcomes.

  16. High-resolution and high-conductive electrode fabrication on a low thermal resistance flexible substrate

    NASA Astrophysics Data System (ADS)

    Kang, Bongchul; Kno, Jinsung; Yang, Minyang

    2011-07-01

    Processes based on the liquid-state pattern transfer, like inkjet printing, have critical limitations including low resolution and low electrical conductivity when fabricating electrodes on low thermal resistance flexible substrates such as polyethylene terephthalate (PET). Those are due to the nonlinear transfer mechanism and the limit of the sintering temperature. Although the laser direct curing (LDC) of metallic inks is an alternative process to improve the resolution, it is also associated with the disadvantages of causing thermal damage to the polymer substrate. This paper suggests the laser induced pattern adhesion transfer method to fabricate electrodes of both high electrical conductivity and high resolution on a PET substrate. First, solid patterns are cost-effectively created by the LDC of the organometallic silver ink on a glass that is optically and thermally stable. The solid patterns sintered on the glass are transferred to the PET substrate by the photo-thermally generated adhesion force of the substrate. Therefore, we achieved electrodes with a minimum line width of 10 µm and a specific resistance of 3.6 μΩcm on the PET substrate. The patterns also showed high mechanical reliability.

  17. High levels of adherence to a rectal microbicide gel and to oral Pre-Exposure Prophylaxis (PrEP) achieved in MTN-017 among men who have sex with men (MSM) and transgender women

    PubMed Central

    Carballo-Diéguez, Alex; Marzinke, Mark A.; Hendrix, Craig W.; Piper, Jeanna M.; Richardson, Barbra A.; Grossman, Cynthia; Johnson, Sherri; Gomez, Kailazarid; Horn, Stephanie; Kunjara Na Ayudhya, Ratiya Pamela; Patterson, Karen; Jacobson, Cindy; Bekker, Linda-Gail; Chariyalertsak, Suwat; Chitwarakorn, Anupong; Gonzales, Pedro; Holtz, Timothy H.; Liu, Albert; Mayer, Kenneth H.; Zorrilla, Carmen; Lama, Javier; McGowan, Ian; Cranston, Ross D.

    2017-01-01

    Trials to assess microbicide safety require strict adherence to prescribed regimens. If adherence is suboptimal, safety cannot be adequately assessed. MTN-017 was a phase 2, randomized sequence, open-label, expanded safety and acceptability crossover study comparing 1) daily oral emtricitabine/tenofovir disoproxil fumarate (FTC/TDF), 2) daily use of reduced-glycerin 1% tenofovir (RG-TFV) gel applied rectally, and 3) RG-TFV gel applied before and after receptive anal intercourse (RAI)—if participants had no RAI in a week, they were asked to use two doses of gel within 24 hours. Product use was assessed by mixed methods including unused product return count, text messaging reports, and qualitative plasma TFV pharmacokinetic (PK) results. Convergence interviews engaged participants in determining the most accurate number of doses used based on product count and text messaging reports. Client-centered adherence counseling was also used. Participants (N = 187) were men who have sex with men and transgender women enrolled in the United States (42%), Thailand (29%), Peru (19%) and South Africa (10%). Mean age was 31.4 years (range 18–64 years). Based on convergence interviews, over an 8-week period, 94% of participants had ≥80% adherence to daily tablet, 41% having perfect adherence; 83% had ≥80% adherence to daily gel, 29% having perfect adherence; and 93% had ≥80% adherence to twice-weekly use during the RAI-associated gel regimen, 75% having perfect adherence and 77% having ≥80% adherence to gel use before and after RAI. Only 4.4% of all daily product PK results were undetectable and unexpected (TFV concentrations <0.31 ng/mL) given self-reported product use near sampling date. The mixed methods adherence measurement indicated high adherence to product use in all three regimens. Adherence to RAI-associated rectal gel use was as high as adherence to daily oral PrEP. A rectal microbicide gel, if efficacious, could be an alternative for individuals

  18. High levels of adherence to a rectal microbicide gel and to oral Pre-Exposure Prophylaxis (PrEP) achieved in MTN-017 among men who have sex with men (MSM) and transgender women.

    PubMed

    Carballo-Diéguez, Alex; Balán, Ivan C; Brown, William; Giguere, Rebecca; Dolezal, Curtis; Leu, Cheng-Shiun; Marzinke, Mark A; Hendrix, Craig W; Piper, Jeanna M; Richardson, Barbra A; Grossman, Cynthia; Johnson, Sherri; Gomez, Kailazarid; Horn, Stephanie; Kunjara Na Ayudhya, Ratiya Pamela; Patterson, Karen; Jacobson, Cindy; Bekker, Linda-Gail; Chariyalertsak, Suwat; Chitwarakorn, Anupong; Gonzales, Pedro; Holtz, Timothy H; Liu, Albert; Mayer, Kenneth H; Zorrilla, Carmen; Lama, Javier; McGowan, Ian; Cranston, Ross D

    2017-01-01

    Trials to assess microbicide safety require strict adherence to prescribed regimens. If adherence is suboptimal, safety cannot be adequately assessed. MTN-017 was a phase 2, randomized sequence, open-label, expanded safety and acceptability crossover study comparing 1) daily oral emtricitabine/tenofovir disoproxil fumarate (FTC/TDF), 2) daily use of reduced-glycerin 1% tenofovir (RG-TFV) gel applied rectally, and 3) RG-TFV gel applied before and after receptive anal intercourse (RAI)-if participants had no RAI in a week, they were asked to use two doses of gel within 24 hours. Product use was assessed by mixed methods including unused product return count, text messaging reports, and qualitative plasma TFV pharmacokinetic (PK) results. Convergence interviews engaged participants in determining the most accurate number of doses used based on product count and text messaging reports. Client-centered adherence counseling was also used. Participants (N = 187) were men who have sex with men and transgender women enrolled in the United States (42%), Thailand (29%), Peru (19%) and South Africa (10%). Mean age was 31.4 years (range 18-64 years). Based on convergence interviews, over an 8-week period, 94% of participants had ≥80% adherence to daily tablet, 41% having perfect adherence; 83% had ≥80% adherence to daily gel, 29% having perfect adherence; and 93% had ≥80% adherence to twice-weekly use during the RAI-associated gel regimen, 75% having perfect adherence and 77% having ≥80% adherence to gel use before and after RAI. Only 4.4% of all daily product PK results were undetectable and unexpected (TFV concentrations <0.31 ng/mL) given self-reported product use near sampling date. The mixed methods adherence measurement indicated high adherence to product use in all three regimens. Adherence to RAI-associated rectal gel use was as high as adherence to daily oral PrEP. A rectal microbicide gel, if efficacious, could be an alternative for individuals uninterested in

  19. Adolescent Smoking Cessation With Bupropion: The Role of Adherence.

    PubMed

    Leischow, Scott J; Muramoto, Myra L; Matthews, Eva; Floden, Lysbeth L; Grana, Rachel A

    2016-05-01

    While many medications can be effective aids to quitting tobacco, real world adherence to smoking cessation medications may render a potentially effective medication ineffective. The present study investigated the role of adherence on treatment outcomes in a bupropion dose-response study among adolescent smokers trying to quit smoking. Three hundred twelve adolescent boys (n = 143) and girls (n = 169) between the ages of 14-17 were enrolled in the study, and were randomly assigned to use either 300 mg, 150 mg or placebo bupropion to quit smoking. Among the eligibility criterion, participants had to smoke at least six cigarettes per day, be motivated to quit smoking (self report), have an exhaled carbon monoxide level greater than or equal to 10 ppm, and report at least two previous quit attempts. Adherence to medication was determined by both self-report and actual counts of unused medication and empty medication packaging. Smoking status was determined by a combination of self-report and biochemical verification (breath carbon monoxide and urine cotinine). Cotinine-confirmed quit rates were significantly higher as a function of high adherence (20.69%) relative to low adherence (0.00%) in the 300-mg Bupropion Sustained Release group. Overall adherence in all study conditions in this highly controlled study was high (74%), but was significantly lower in non-white participants. Effectiveness of bupropion for adolescent smoking cessation is contingent on achieving high rates of medication adherence, but considerable variations in adherence impacted outcomes. Few studies have assessed the safety and efficacy of medications to help adolescent smokers quit, and we conducted one such study assessing bupropion. In this analysis of that original study, we assess the role of adherence in use of medication and quit rates. We found that adherence was related to outcomes, particularly in the 300-mg dose of bupropion. © The Author 2015. Published by Oxford University Press on

  20. Vets, denialists and rememberers: social typologies of patient adherence and non-adherence to HAART from the perspective of HIV care providers.

    PubMed

    Orchard, Treena; Salters, Kate; Palmer, Alexis; Michelow, Warren; Lepik, Katherine J; Hogg, Robert

    2015-01-01

    For many people living with HIV/AIDS taking highly active antiretroviral therapy (HAART) is difficult due to various individual and social factors, including the side effects of these medications, HIV/AIDS stigma and poor patient-provider relationships. Most studies that examine barriers to and facilitators of adherence to HAART have been conducted with people on these medications, which is critical to improving adherence among various HIV-affected groups. Less attention has been paid to the experiences of HIV care providers, which is an important gap in the literature considering the key role they play in the delivery of HAART and the management of patient treatment plans. This paper presents findings from a qualitative pilot study that explored how HIV care providers assess adherence and non-adherence to HAART among their HIV-positive patients in Vancouver, British Columbia. Drawing upon individual interviews conducted with HIV physicians (n = 3), social service providers (n = 3) and pharmacists (n = 2), this discussion focuses on the social typologies our participants use to assess patient success and failure related to adherence. Eleven unique categories are featured and the diversity within and across these categories illustrate a broad spectrum of adherence-related behaviours among patients and the social meanings providers attribute to these behaviours. As one of the first explorations of the social typologies used by HIV care providers to assess patient performance on HAART, these data contribute valuable insights into the experiences of providers within the context of adherence-related care delivery.

  1. A Qualitative Study of Patient Motivation to Adhere to Combination Antiretroviral Therapy in South Africa

    PubMed Central

    Gray, Debra; Gengiah, Santhanalakshmi; Kunene, Pinky; Gengiah, Tanuja N.; Naidoo, Kogieleum; Grant, Alison D.

    2015-01-01

    Abstract Taken as prescribed, that is, with high adherence, combination antiretroviral therapy (ART) has changed HIV infection and disease from being a sure predictor of death to a manageable chronic illness. Adherence, however, is difficult to achieve and maintain. The CAPRISA 058 study was conducted between 2007 and 2009 to test the efficacy of individualized motivational counselling to enhance ART adherence in South Africa. As part of the overall trial, a qualitative sub-study was conducted, including 30 individual interviews and four focus group discussions with patients in the first 9 months of ART initiation. Data were inductively analyzed, using thematic analysis, to identify themes central to ART adherence in this context. Four themes emerged that characterize the participants' experiences and high motivation to adhere to ART. Participants in this study were highly motivated to adhere, as they acknowledged that ART was ‘life-giving’, in the face of a large amount of morbidity and mortality. They were further supported by techniques of routine remembering, and highlighted the importance of good social support and access to supportive healthcare workers, to their continued success in negotiating their treatment. Participants in the current study told us that their adherence motivation is enhanced by free accessible care, approachable and supportive healthcare workers, broad social acceptance of ART, and past first-hand experiences with AIDS-related co-morbidity and mortality. Programs that include specific attention to these aspects of care will likely be successful in the long term. PMID:25692575

  2. Mediterranean diet adherence by patients with primary open angle glaucoma.

    PubMed

    Abreu-Reyes, J A; Álvarez-Luis, D; Arteaga-Hernández, V; Sánchez-Mendez, M; Abreu-González, R

    2017-08-01

    To study the adherence to the Mediterranean diet in patients affected by primary open angle glaucoma (POAG). An observational study was conducted to assess the adherence to the Mediterranean diet in patients affected by POAG, and who attended the Ophthalmology Department of the Canary Islands University Hospital. The study included completing a 14-item questionnaire validated by the PREDIMED Study, in person or by telephone. A total of 100 questionnaires were completed successfully by 50 males and 50 females. The mean age was 69.58 years for the males and 67.42 years for women. The men had more comorbidities than women (tobacco 14 vs. 3%), arterial hypertension, and diabetes (30 vs. 28%, and 16 vs. 6%, respectively). Adherence to the Mediterranean diet in males, was low in 9 patients (18%), moderate in 37 (74%), and high in 4 (8%) cases. In women adherence was low in 14 patients (28%), moderate in 34 (68%), and high in 2 (6%) cases. The overall adhesion to the Mediterranean diet is low in 23%, moderate in 71% and high in 6% of the cases. Patients who are affected by POAG have moderate adherence to the Mediterranean diet. Copyright © 2017 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

  3. Spermine selectively inhibits high-conductance, but not low-conductance calcium-induced permeability transition pore.

    PubMed

    Elustondo, Pia A; Negoda, Alexander; Kane, Constance L; Kane, Daniel A; Pavlov, Evgeny V

    2015-02-01

    The permeability transition pore (PTP) is a large channel of the mitochondrial inner membrane, the opening of which is the central event in many types of stress-induced cell death. PTP opening is induced by elevated concentrations of mitochondrial calcium. It has been demonstrated that spermine and other polyamines can delay calcium-induced swelling of isolated mitochondria, suggesting their role as inhibitors of the mitochondrial PTP. Here we further investigated the mechanism by which spermine inhibits the calcium-induced, cyclosporine A (CSA) -sensitive PTP by using three indicators: 1) calcium release from the mitochondria detected with calcium green, 2) mitochondrial membrane depolarization using TMRM, and 3) mitochondrial swelling by measuring light absorbance. We found that despite calcium release and membrane depolarization, indicative of PTP activation, mitochondria underwent only partial swelling in the presence of spermine. This was in striking contrast to the high-amplitude swelling detected in control mitochondria and in mitochondria treated with the PTP inhibitor CSA. We conclude that spermine selectively prevents opening of the high-conductance state, while allowing activation of the lower conductance state of the PTP. We propose that the existence of lower conductance, stress-induced PTP might play an important physiological role, as it is expected to allow the release of toxic levels of calcium, while keeping important molecules (e.g., NAD) within the mitochondrial matrix.

  4. Factors associated with adherence to asthma treatment with inhaled corticosteroids: A cross-sectional exploratory study.

    PubMed

    Adouni Lawani, Moulikatou; Zongo, Frank; Breton, Marie-Claude; Moisan, Jocelyne; Grégoire, Jean-Pierre; Dorval, Eileen; Boulet, Louis-Philippe; Jobin, Marie-Sophie; Guénette, Line

    2017-05-04

    Understanding factors at the patient, provider or organizational level associated with inhaled corticosteroids (ICSs) adherence is important when planning adherence-enhancing interventions. To explore factors associated with adherence to ICS among patients with asthma aged 12-45 years. A cross-sectional study was conducted among patients with asthma reporting ICS prescription during the baseline interview of an intervention study. Three methods were used to measure ICS adherence: a 4-item self-report questionnaire, a single question (SQ) measuring past 7-day exposure to ICS and a medication possession ratio (MPR, i.e., the sum of ICS days of supply/365). We assessed 46 potential factors of ICS adherence derived from the Predisposing, Reinforcing and Enabling Constructs in Educational Diagnosis and Evaluation (PRECEDE) model. Their association with ICS adherence was measured using multivariate logistic regressions. Among the 319 participants included, 16.0% were deemed adherent according to the 4-item questionnaire. This proportion was 43.0% and 9.1% for the SQ and the MPR method, respectively. Ten factors were associated with good ICS adherence. Among these factors, four were associated with adherence through one of the measuring methods: a low family income level, a high number of asthma drugs used, a good knowledge of asthma pathophysiology and the perception that following the ICS prescription was easy. Two factors emerged through more than one measure: perceiving asthma severity as moderate to very severe and perceiving a high risk of death if ICSs are not taken as prescribed. ICS adherence was poor in those individuals with asthma. Future adherence-enhancing interventions could target the identified modifiable risk factors. ClinicalTrials.gov Identifier NCT02093013.

  5. K+ Conduction and Mg2+ Blockade in a Shaker Kv-Channel Single Point Mutant with an Unusually High Conductance

    PubMed Central

    Moscoso, Cristian; Vergara-Jaque, Ariela; Márquez-Miranda, Valeria; Sepúlveda, Romina V.; Valencia, Ignacio; Díaz-Franulic, Ignacio; González-Nilo, Fernando; Naranjo, David

    2012-01-01

    Potassium channels exhibit a large diversity of single-channel conductances. Shaker is a low-conductance K-channel in which Pro475→Asp, a single-point mutation near the internal pore entrance, promotes 6- to 8-fold higher unitary current. To assess the mechanism for this higher conductance, we measured Shaker-P475D single-channel current in a wide range of symmetrical K+ concentrations and voltages. Below 300 mM K+, the current-to-voltage relations (i-V) showed inward rectification that disappeared at 1000 mM K+. Single-channel conductance reached a maximum of ∼190 pS at saturating [K+], a value 4- to 5-fold larger than that estimated for the native channel. Intracellular Mg2+ blocked this variant with ∼100-fold higher affinity. Near zero voltage, blockade was competitively antagonized by K+; however, at voltages >100 mV, it was enhanced by K+. This result is consistent with a lock-in effect in a single-file diffusion regime of Mg2+ and K+ along the pore. Molecular-dynamics simulations revealed higher K+ density in the pore, especially near the Asp-475 side chains, as in the high-conductance MthK bacterial channel. The molecular dynamics also showed that K+ ions bound distally can coexist with other K+ or Mg2+ in the cavity, supporting a lock-in mechanism. The maximal K+ transport rate and higher occupancy could be due to a decrease in the electrostatic energy profile for K+ throughout the pore, reducing the energy wells and barriers differentially by ∼0.7 and ∼2 kT, respectively. PMID:22995492

  6. Latest Progress In Novel High Conductivity And Highly Stable Composite Structure Developments For Satellite Applications

    NASA Astrophysics Data System (ADS)

    Klebor, Maximillian; Reichmann, Olaf; Pfeiffer, Ernst K.; Ihle, Alexander; Linke, Stefan; Tschepe, Christoph; Roddecke, Susanne; Richter, Ines; Berrill, Mark; Santiago-Prowald, Julian

    2012-07-01

    Materials such as aluminium, titanium and carbon fibre based composites are indispensable in space business. However, special demands on spaceborne applications require both new ideas and new concepts but also powerful novel materials. These days the trend is to substitute aluminium for CFRP basically in order to safe mass or to decrease thermal expansions. Nevertheless there are upcoming requirements that cannot be met using standard CFRP materials. In this connection innovative composites have to be introduced. In the frame of this paper three major applications for such material requests are considered, i.e.: • antennas • satellite platform structural panels • radiators. The new composites need to cope with the following challenges and demands: high operational temperature range, high stiffness, high strength, high thermal conductivity, vacuum compatibility, low mass, high in- orbit stability, compatibility with metallic parts and many more. Some of these demands have to be fulfilled in conjunction. Herein the innovative composites cover new raw materials and their combination, manufacturing process enhancement as well as new inspection and test methods. It has been observed that by using the developed CFRPs it is possible to satisfy and excel the needs. However, these materials feature a different behaviour than conventional composites which has to be taken into account during future design.

  7. Very high childhood obesity prevalence and low adherence rates to the Mediterranean diet in Greek children: the GRECO study.

    PubMed

    Farajian, Paul; Risvas, Grigoris; Karasouli, Konstantina; Pounis, Georgios D; Kastorini, Christina M; Panagiotakos, Demosthenes B; Zampelas, Antonis

    2011-08-01

    In order to provide estimates of overweight and obesity among Greek schoolchildren, and the adherence rates to the Mediterranean diet (MD), a nationwide survey was performed among fifth and sixth grade students aged 10-12 years old. A stratified sampling in 10 regions of the country was applied to voluntarily enroll a representative sample of 4786 children. Children were weighed and measured and completed a semi-quantitative food frequency questionnaire with a supplementary section for the assessment of dietary aspects and physical activity levels. Additionally, the KIDMED index was used to evaluate the degree of adherence to the MD. According to the IOTF cut-offs, overweight (OW) and obesity (OB) prevalence among boys was 29.9% and 12.9%, while in girls 29.2% and 10.6%, respectively. Only 4.3% of the children had an optimal KIDMED score. KIDMED score did not differ between boys and girls and no differences were detected between normal weight and OW and OB children. However, children from semi-urban or rural regions had higher score. Furthermore, children with higher KIDMED score reported following a healthier diet and having higher physical activity levels. The prevalence of childhood obesity in Greece is the highest ever reported together with low adherence rates to the dietary patterns of the MD. Current findings suggest an increased risk for even higher rates of obesity in adolescence and adulthood in the near future. Taking into account that children are also abandoning the traditional cardio-protective MD, the increased risk for future adverse health consequences seems evident. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  8. Tensile and electrical properties of high-strength high-conductivity copper alloys

    SciTech Connect

    Zinkle, S.J.; Eatherly, W.S.

    1998-09-01

    Electrical conductivity and tensile properties have been measured on an extruded and annealed CuCrNb dispersion strengthened copper alloy which has been developed for demanding aerospace high heat flux applications. The properties of this alloy are somewhat inferior to GlidCop dispersion strengthened copper and prime-aged CuCrZr over the temperature range of 20--500 C. However, if the property degradation in CuCrZr due to joining operations and the anisotropic properties of GlidCop in the short transverse direction are taken into consideration, CuCrNb may be a suitable alternative material for high heat flux structural applications in fusion energy devices. The electrical conductivity and tensile properties of CuCrZr that was solution annealed and then simultaneously aged and diffusion bonded are also summarized. A severe reduction in tensile elongation is observed in the diffusion bonded joint, particularly if a thin copper shim is not placed in the diffusion bondline.

  9. Highly Porous, Rigid-Rod Polyamide Aerogels with Superior Mechanical Properties and Unusually High Thermal Conductivity.

    PubMed

    Williams, Jarrod C; Nguyen, Baochau N; McCorkle, Linda; Scheiman, Daniel; Griffin, Justin S; Steiner, Stephen A; Meador, Mary Ann B

    2017-01-18

    We report here the fabrication of polyamide aerogels composed of poly-p-phenylene-terephthalamide, the same backbone chemistry as DuPont's Kevlar. The all-para-substituted polymers gel without the use of cross-linker and maintain their shape during processing-an improvement over the meta-substituted cross-linked polyamide aerogels reported previously. Solutions containing calcium chloride (CaCl2) and para-phenylenediamine (pPDA) in N-methylpyrrolidinone (NMP) at low temperature are reacted with terephthaloyl chloride (TPC). Polymerization proceeds over the course of 5 min resulting in gelation. Removal of the reaction solvent via solvent exchange followed by extraction with supercritical carbon dioxide provides aerogels with densities ranging from 0.1 to 0.3 g/cm(3), depending on the concentration of calcium chloride, the formulated number of repeat units, n, and the concentration of polymer in the reaction mixture. These variables were assessed in a statistical experimental study to understand their effects on the properties of the aerogels. Aerogels made using at least 30 wt % CaCl2 had the best strength when compared to aerogels of similar density. Furthermore, aerogels made using 30 wt % CaCl2 exhibited the lowest shrinkage when aged at elevated temperatures. Notably, whereas most aerogel materials are highly insulating (thermal conductivities of 10-30 mW/m K), the polyamide aerogels produced here exhibit remarkably high thermal conductivities (50-80 mW/(m K)) at the same densities as other inorganic and polymer aerogels. These high thermal conductivities are attributed to efficient phonon transport by the rigid-rod polymer backbone. In conjunction with their low cost, ease of fabrication with respect to other polymer aerogels, low densities, and high mass-normalized strength and stiffness properties, these aerogels are uniquely valuable for applications such as lightweighting in consumer electronics, automobiles, and aerospace where weight reduction is

  10. Adherence to Pharmacotherapy and Medication-Related Beliefs in Patients with Hypertension in Lima, Peru

    PubMed Central

    Miranda, J. Jaime; Diez-Canseco, Francisco; Malaga, German

    2014-01-01

    Objective To characterize adherence to pharmacological medication and beliefs towards medication in a group of patients with hypertension in a large national hospital. Materials and Methods Cross-sectional survey among patients with hypertension attending the outpatient clinic of a large national hospital. Exposure of interest was the patient's beliefs towards general medication and antihypertensive drugs, i.e. beliefs of harm, overuse, necessity and concern, measured using the Beliefs about Medication questionnaire. Main outcome was adherence measured using the Morisky Medication Adherence Scale-8. Multivariate analysis was conducted using Poisson distribution logistic regression, prevalence ratios and 95% confidence intervals were calculated. Results Data from 115 participants, 67% females and mean age 62.7 years were analyzed. Low adherence was found in 57.4%. Highest scores were on the ideas of necessity and one of the most rated statements was “physicians would prescribe less medication if they spent more time with patients”. Beliefs of harm about medications and concerns about antihypertensive drugs were higher in the low adherence group (p<0.01). Those who scored higher on ideas of harm were 52% less likely of being high adherents (PR 0.48; 95% CI 0.25–0.93) and those with higher scores on concerns were 41% less likely of being high adherents (PR 0.59; 95% CI 0.39–0.91). Patients whose ideas of necessity outweighed their concerns were more likely to be adherent (PR 2.65; 95% CI 1.21–5.81). Conclusions Low adherence to antihypertensive medication is common. High scores on ideas of harm, concern and a high necessity-concern differential were predictors of medication adherence. PMID:25470372

  11. Improving medication adherence among community-dwelling seniors with cognitive impairment: a systematic review of interventions.

    PubMed

    Kröger, Edeltraut; Tatar, Ovidiu; Vedel, Isabelle; Giguère, Anik M C; Voyer, Philippe; Guillaumie, Laurence; Grégoire, Jean-Pierre; Guénette, Line

    2017-08-01

    Background Medication non-adherence may lead to poor therapeutic outcomes. Cognitive functions deteriorate with age, contributing to decreased adherence. Interventions have been tested to improve adherence in seniors with cognitive impairment or Alzheimer disease (AD), but high-quality systematic reviews are lacking. It remains unclear which interventions are promising. Objectives We conducted a systematic review to identify, describe, and evaluate interventions aimed at improving medication adherence among seniors with any type of cognitive impairment. Methods Following NICE guidance, databases and websites were searched using combinations of controlled and free vocabulary. All adherence-enhancing interventions and study designs were considered. Studies had to include community dwelling seniors, aged 65 years or older, with cognitive impairment, receiving at least one medication for a chronic condition, and an adherence measure. Study characteristics and methodological quality were assessed. Results We identified 13 interventions, including six RCTs. Two studies were of poor, nine of low/medium and two of high quality. Seven studies had sample sizes below 50 and six interventions focused on adherence to AD medication. Six interventions tested a behavioral, four a medication oriented, two an educational and one a multi-faceted approach. Studies rarely assessed therapeutic outcomes. All but one intervention showed improved adherence. Conclusion Three medium quality studies showed better adherence with patches than with pills for AD treatment. Promising interventions used educational or reminding strategies, including one high quality RCT. Nine studies were of low/moderate quality. High quality RCTs using a theoretical framework for intervention selection are needed to identify strategies for improved adherence in these seniors.

  12. Fabrication of high thermal conductive Al-cBN ceramic sinters by high temperature high pressure method

    NASA Astrophysics Data System (ADS)

    Wang, P. F.; Li, Zh. H.; Zhu, Y. M.

    2011-05-01

    Al-cBN ceramic sinters were fabricated by sintering micro-powder mixture of Al and cBN under high temperature and high pressure condition. Differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electronic microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) elemental mapping analyses and laser flashing thermal conductivity measurements were performed to investigate the sintering properties and thermal conductivity of the Al-cBN ceramic sinters. XRD analysis revealed these Al-cBN ceramic sinters were composed of a large portion of cBN and of a small portion of AlN, and very little amount of AlB 12 and hBN. Formation of boundary phase resulted in the rapid densification of the sinters, as well as the increase of their relative density with increasing Al additions. The Al-cBN ceramic sinters have a maximum thermal conductivity of about 1.94 W/cm K at room temperature and a much higher value of about 2.04 W/cm K at 200 °C. Their high thermal conductivity over that of AlN-hBN composites promise Al-cBN ceramic sinters favorite candidates as high efficiency heat sink materials for wide band gap semiconductors.

  13. Bridging the gap between antiretroviral access and adherence in Mexico.

    PubMed

    Campero, Lourdes; Herrera, Cristina; Kendall, Tamil; Caballero, Marta

    2007-05-01

    The goal in this article is to examine social problems associated with highly active antiretroviral therapy (HAART) adherence in Mexico and the related challenges for Mexican persons living with HIV/AIDS (PLWHAs). The study was conducted from the perspective of infected and affected individuals. The authors completed 64 in-depth interviews with heterosexual male and female PLWHAs, as well as with some key individuals from their social network. Following the principles of grounded theory, they carried out inductive analysis to create codes and organize central themes. The authors identified problems related to accessing HAART and found that conditions for implementing recommendations made in the international literature to improve adherence are poor. The findings highlight the importance of social factors, such as health care system irregularities, ineffective physician-patient communication, and availability of family and other sources of social support such as self-help groups for PLWHAs' access and adherence to antiretroviral therapy in Mexico.

  14. Evaluation of adherence predictors for the treatment of moderate to severe psoriasis with biologics: the importance of physician-patient interaction and communication.

    PubMed

    Zschocke, I; Ortland, C; Reich, K

    2017-06-01

    Treatment efficacy of biologic agents in moderate to severe psoriasis is regarded as high with patient adherence being higher than for traditional therapies. However, use of biologics is connected to high discontinuation rates. The current investigator-initiated study was conducted to improve the understanding of adherence. The study was designed as non-interventional retrospective multicentre trial in Germany. Questionnaires were developed based on the adherence dimensions identified by the World Health Organization, WHO. Thirteen dermatologists and 246 patients participated in the study and replied to the questionnaires. Study data were analysed for potential predictors of adherence in an explorative manner. Based on the physician's assessment of the patients' individual adherence, subsets of adherent and non-adherent patients were discriminated. Two main drivers were identified on the patients' side that were positively connected to adherence: a lack of efficacy of the previous treatments and the knowledge of comorbidities associated with severe psoriasis. Furthermore, physician-patient communication seems to play a central role, as on the dermatologists' side, there was a strong association of adherence and positive personal interrelation between dermatologist and patient. The data reported here underline the importance of patient education and information delivery to optimize patient adherence and thereby treatment outcomes. Treating physicians should be aware that soft aspects of their interaction with the patient might influence treatment adherence. © 2017 European Academy of Dermatology and Venereology.

  15. Establishing Specifications for Low Enriched Uranium Fuel Operations Conducted Outside the High Flux Isotope Reactor Site

    SciTech Connect

    Pinkston, Daniel; Primm, Trent; Renfro, David G; Sease, John D

    2010-10-01

    The National Nuclear Security Administration (NNSA) has funded staff at Oak Ridge National Laboratory (ORNL) to study the conversion of the High Flux Isotope Reactor (HFIR) from the current, high enriched uranium fuel to low enriched uranium fuel. The LEU fuel form is a metal alloy that has never been used in HFIR or any HFIR-like reactor. This report provides documentation of a process for the creation of a fuel specification that will meet all applicable regulations and guidelines to which UT-Battelle, LLC (UTB) the operating contractor for ORNL - must adhere. This process will allow UTB to purchase LEU fuel for HFIR and be assured of the quality of the fuel being procured.

  16. Factors influencing medication adherence in patients with gout: A descriptive correlational study.

    PubMed

    Chua, Xin Hui Jasmine; Lim, Siriwan; Lim, Fui Ping; Lim, Yee Nah Anita; He, Hong-Gu; Teng, Gim Gee

    2017-06-15

    To examine the factors influencing adherence to urate-lowering therapy in patients with gout in Singapore. Gout is the most common type of chronic inflammatory arthritis. Urate-lowering therapy (ULT) is used to treat gout by reducing serum uric acid levels. However, adherence to ULT among patients remains poor. To date, there have been no available studies based on a conceptual framework that examined factors influencing medication adherence in patients with gout. Cross-sectional, descriptive correlational study. A convenience sample of outpatients (n = 108) was recruited between October 2014 and January 2015 from a tertiary hospital in Singapore. Outcomes were measured by relevant valid and reliable instruments. Descriptive statistics and parametric tests including multiple linear regression were used to analyse the data. Although 44.4% of the participants were high adherers to urate-lowering therapy, the mean adherence level was moderate. Significant differences in medication adherence scores were found among the subgroups of gender, ethnicity, marital status, employment status, and presence of comorbidity. Medication adherence was positively significantly correlated with age, number of comorbidities, and beliefs about medicines. Linear regression showed that higher level of beliefs about medicines, presence of comorbidity, and being married were factors positively influencing medication adherence. This study revealed moderate adherence to ULT in patients with gout in Singapore, indicating the need for strategies to improve adherence by considering its main influencing factors. Future research should be conducted to develop interventions targeted at modifying patients' beliefs about medicines in order to improve medication adherence. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  17. Treatment adherence in patients with headache: a systematic review.

    PubMed

    Ramsey, Rachelle R; Ryan, Jamie L; Hershey, Andrew D; Powers, Scott W; Aylward, Brandon S; Hommel, Kevin A

    2014-05-01

    To review and critically evaluate the extant research literature pertaining to adherence in youth and adults with headache and to provide recommendations for future research. This article provides the first systematic review of pediatric headache adherence and updates a previous review of treatment adherence in adults with headache. Systematic review of empirical literature. A literature search with no date restriction was conducted using PubMed and PsycINFO electronic databases and bibliographies of relevant articles. Adherence rates in adults with headache range considerably from 25% to 94% across treatment, assessment method, and definition of adherence utilized. Methods to assess adherence included retrospective prescription claims data, paper or electronic diaries, follow-up appointment attendance, written and verbal self-report of general adherence, verbal self-report of adherence over a specific amount of time via in person interview or telephone, validated adherence measures, adherence questionnaires without validation, and counselor ratings of homework. Each methodology and assessment tool demonstrated strengths and weaknesses. No studies have systematically examined medication adherence in children with headache, and the few available studies examining adherence to behavioral treatment have documented adherence rates ranging from 52% to 86%. Adherence research in adults with headache is growing, but studies demonstrate a number of methodological shortcomings. Adherence research in children with headache, and adherence intervention research in both adults and children, is scant. Future research should use objective measures of adherence, consider over-the-counter medications and medication overuse, examine demographic, psychological, and behavioral correlates of adherence, assess adherence to botulinum toxin type A, and examine the efficacy of adherence interventions in individuals with headache. © 2014 American Headache Society.

  18. Might ART Adherence Estimates Be Improved by Combining Biomarker and Self-Report Data?

    PubMed Central

    Rhead, Rebecca; Masimirembwa, Collen; Cooke, Graham; Takaruza, Albert; Nyamukapa, Constance; Mutsimhi, Cosmas; Gregson, Simon

    2016-01-01

    Background As we endeavour to examine rates of viral suppression in PLHIV, reliable data on ART adherence are needed to distinguish between the respective contributions of poor adherence and treatment failure on high viral load. Self-reported data are susceptible to response bias and although biomarker data on drug presence and concentration can provide a superior, alternative method of measurement, complications due to drug-drug interactions and genetic variations can cause some inaccuracies. We investigate the feasibility of combining both biomarker and self-report data to produce a potentially more accurate measure of ART adherence. Methods Data were taken from a large general-population survey in the Manicaland province, Zimbabwe, conducted in 2009–2011. HIV-infected adults who had initiated ART (N = 560) provided self-report data on adherence and dried blood spot samples that were analysed for traces of ART medication. A new three-category measure of ART adherence was constructed, based on biomarker data but using self-report data to adjust for cases with abnormally low and high drug concentrations due to possible drug-drug interactions and genetic factors, and was assessed for plausibility using survey data on socio-demographic correlates. Results 94.3% (528/560) and 92.7% (519/560) of the sample reported faithful adherence to their medication and had traces of ART medication, respectively. The combined measure estimated good evidence of ART adherence at 69% and excellent evidence of adherence at 53%. The regression analysis results showed plausible patterns of ART adherence by socio-demographic status with men and younger participants being more likely to adhere poorly to medication, and higher socio-economic status individuals and those living in more urban locations being more likely to adhere well. Conclusion Biomarker and self-reported measures of adherence can be combined in a meaningful way to produce a potentially more accurate measure of ART

  19. High yield sample preconcentration using a highly ion-conductive charge-selective polymer.

    PubMed

    Chun, Honggu; Chung, Taek Dong; Ramsey, J Michael

    2010-07-15

    The development and analysis of a microfluidic sample preconcentration system using a highly ion-conductive charge-selective polymer [poly-AMPS (2-acrylamido-2-methyl-1-propanesulfonic acid)] is reported. The preconcentration is based on the phenomenon of concentration polarization which develops at the boundaries of the poly-AMPS with buffer solutions. A negatively charged polymer, poly-AMPS, positioned between two microchannels efficiently extracts cations through its large cross section, resulting in efficient anion sample preconcentration. The present work includes the development of a robust polymer that is stable over a wide range of buffers with varying chemical compositions. The sample preconcentration effect remains linear to over 3 mM (0.15 pmol) and 500 microM (15 fmol) for fluorescein and TRITC-tagged albumin solutions, respectively. The system can potentially be used for concentrating proteins on microfluidic devices with subsequent analysis for proteomic applications.

  20. Cohort study of adherence to adjuvant endocrine therapy, breast cancer recurrence and mortality.

    PubMed

    Makubate, B; Donnan, P T; Dewar, J A; Thompson, A M; McCowan, C

    2013-04-16

    Adjuvant endocrine therapy is recommended for women with oestrogen receptor-positive breast cancer, but many women do not take the medication as directed and they stop treatment before completing the standard 5-year duration. This retrospective cohort study conducted between 1993 and 2008 of all women with incident breast cancer, who are residing in the Tayside region of Scotland, examined adherence to prescribed adjuvant tamoxifen or aromatase inhibitors (AIs). Survival analysis examined the effect of adherence on all-cause mortality, breast cancer death and recurrence, using linked prescribing, cancer registry, clinical cancer audit, hospital discharge and death records. A total of 3361 women with breast cancer were followed for a median 4.47 years (interquartile range (IQR)=2.04-8.55). The median overall adherence was 90% (IQR=90-100%), but the annual adherence reduced after a longer period from diagnosis. Low adherence of <80% was associated with poorer survival (hazard ratios=1.20; 95% confidence interval=1.03-1.40, P=0.019). There was no significant difference for low adherence over the treatment period and recurrence, or breast cancer death, but patients with high annual adherence for 5 years had better outcomes than those with 3 or less. Low adherence to all adjuvant endocrine therapy for women with breast cancer, whether tamoxifen or AI, increases the risk of death.

  1. Factors associated with antidiabetic medication non-adherence in patients with incident comorbid depression.

    PubMed

    Lunghi, Carlotta; Zongo, Arsène; Moisan, Jocelyne; Grégoire, Jean-Pierre; Guénette, Line

    2017-07-01

    To identify factors associated with antidiabetic drug (AD) non-adherence among patients with type 2 diabetes and depression. We conducted a population-based retrospective cohort study among new AD users with a diagnosis of depression following AD initiation. We used public health insurance data from Quebec. The dependent variable was non-adherence (i.e., <90% of days covered by ≥1AD) in the year after a depression diagnosis. Different sociodemographic, clinical and medication-related variables were assessed as potential factors of non-adherence to AD treatment. We performed univariate and multivariate logistic regressions. We identified 3106 new users of ADs with a diagnosis of depression between 2000 and 2006. Of these individuals, 52% were considered non-adherent to their ADs. Baseline non-adherence, younger age, the addition of another AD to the initial treatment, <4 drug claims, visits with several different physicians, high socioeconomic status, and a small number of diabetes complications were associated with AD non-adherence. The factors identified in the present study may help clinicians recognize patients with type 2 diabetes and incident depression at increased risk for non-adherence. In these patients, close follow-up and targeted interventions could help improve adherence to AD treatment, improve glycemic control and reduce complications. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Anaerobic granule-based biofilms formation reduces propionate accumulation under high H2 partial pressure using conductive carbon felt particles.

    PubMed

    Xu, Heng; Wang, Cuiping; Yan, Kun; Wu, Jing; Zuo, Jiane; Wang, Kaijun

    2016-09-01

    Syngas based co-digestion is not only more economically attractive than separate syngas methanation but also able to upgrade biogas and increase overall CH4 amount simultaneously. However, high H2 concentration in the syngas could inhibit syntrophic degradation of propionate, resulting in propionate accumulation and even failure of the co-digestion system. In an attempt to reduce propionate accumulation via enhancing both H2 interspecies transfer (HIT) and direct interspecies electron transfer (DIET) pathways, layered granule-based biofilms induced by conductive carbon felt particles (CCFP) was employed. The results showed that propionate accumulation was effectively reduced with influent COD load up to 7gL(-1)d(-1). Two types of granule-based biofilms, namely biofilm adhered to CCFP (B-CCFP) and granules formed by self-immobilization (B-SI) were formed in the reactor. Clostridium, Syntrophobacter, Methanospirillum were possibly involved in HIT and Clostridium, Geobacter, Anaerolineaceae, Methanosaeta in DIET, both of which might be responsible for the high-rate propionate degradation.

  3. Adherence to oral chemotherapy medications among gastroenterological cancer patients visiting an outpatient clinic.

    PubMed

    Hirao, Chieko; Mikoshiba, Naoko; Shibuta, Tomomi; Yamahana, Reiko; Kawakami, Aki; Tateishi, Ryosuke; Yamaguchi, Hironori; Koike, Kazuhiko; Yamamoto-Mitani, Noriko

    2017-09-01

    The purpose of this study was to investigate medication adherence to oral chemotherapy medications and determinants of medication non-adherence to them among gastroenterological cancer patients. A cross-sectional study was conducted on 117 consecutive, consenting, eligible patients visiting an outpatient clinic of university hospital in Japan. Good medication adherence was defined as taking 100% of the prescribed dose. Medication adherence was measured via self-report. We hypothesized that there was a significant relationship between medication non-adherence and the five factors defined by the World Health Organization: patient-related, socioeconomic-related, condition-related, treatment-related, and healthcare-system/provider-related factors. Multiple logistic regression models were used to identify factors associated with oral chemotherapy medication non-adherence. The proportion of patients showing good medication adherence was 56.4%. The multiple logistic regression analysis revealed that the determinants of medication non-adherence to oral chemotherapy medications included having a history of patient-caused treatment interruptions due to worsening of symptoms (adjusted odds ratio [AOR] = 9.59, 95% confidence interval [CI] = 1.38-66.47), having diarrhea (AOR = 3.25, 95% CI = 1.13-9.34), experiencing pain (AOR = 0.17, 95% CI = 0.05-0.55), taking oral chemotherapy medication every 8 h (AOR = 5.52, 95% CI = 1.71-17.81), and diminished sense of priority for medication (AOR = 1.40, 95% CI = 1.21-1.63). This study suggests that many patients with gastroenterological cancer were non-adherent to oral chemotherapy medications. It might be necessary to conduct periodic screening and connect patients at a high risk of medication non-adherence to appropriate support.

  4. Medication non-adherence among adult psychiatric out patients in Jimma University Specialized Hospital, Southwest Ethiopia.

    PubMed

    Tesfay, Kenfe; Girma, Eshetu; Negash, Alemayehu; Tesfaye, Markos; Dehning, Sandra

    2013-11-01

    Information on adherence of adult psychiatric patients to biological modes of treatment is scarce in Ethiopia. Knowledge on adherence is essential in terms of future prognosis, quality of life and functionality of such patients. This study was conducted to assess the magnitude and associated factors of non-adherence to medication. A hospital based cross-sectional study was conducted in November 2011 at the psychiatry facility of Jimma University Specialized Hospital, which provides service to more than 10 mill people. A sample of 422 adults with psychiatric illness in the follow-up outpatients was selected consecutively. Data was collected using a pre-tested questionnaire by face-to-face interview and from patient medical records. The four-item Morisky scale was used to assess degree of medication adherence. Data was analyzed using SPSS version 16 and descriptive, chi-square test and logistic regression statistical methods were used. P-Value of less than 0.05 was considered as statistically significant in the final model. Out of the 422 patients, 40.3% were females and 59.7% males. The prevalence rate for non-adherence was 41.2%, non-affective psychoses diagnosis contributing the highest rate (44.5%). From the total non-adherent respondents, 78.2% attributed their non-adherence to forgetting. Irregular follow-up, poor social support and complex drug regimen were independently associated variables with non-adherence. The result of the study showed that non-adherence among psychiatric patients in Southwest Ethiopia is high and revealed possible associated factors. Adherence needs integrated efforts in creating a mechanism in enhancing regular follow-up, informal social support system and ongoing awareness creation among professionals.

  5. Evaluation of high strength, high conductivity CuNiBe alloys for fusion energy applications

    SciTech Connect

    Zinkle, Steven J

    2014-06-01

    The unirradiated tensile properties for several different heats and thermomechanical treatment conditions of precipitation strengthened Hycon 3HPTM CuNiBe (Cu-2%Ni-0.35%Be in wt.%) have been measured over the temperature range of 20-500 C for longitudinal and long transverse orientations. The room temperature electrical conductivity has also been measured for several heats, and the precipitate microstructure was characterized using transmission electron microscopy. The CuNiBe alloys exhibit very good combination of strength and conductivity at room temperature, with yield strengths of 630-725 MPa and electrical conductivities of 65-72% International Annealed Copper Standard (IACS). The strength remained relatively high at all test temperatures, with yield strengths of 420-520 MPa at 500 C. However, low levels of ductility (<5% uniform elongation) were observed at test temperatures above 200-250 C, due to flow localization near grain boundaries (exacerbated by having only 10-20 grains across the gage thickness of the miniaturized sheet tensile specimens). Scanning electron microscopy observation of the fracture surfaces found a transition from ductile transgranular to ductile intergranular fracture with increasing test temperature. Fission neutron irradiation to a dose of ~0.7 displacements per atom (dpa) at temperatures between 100 and 240 C produced a slight increase in strength and a significant decrease in ductility. The measured tensile elongation increased with increasing irradiation temperature, with a uniform elongation of ~3.3% observed at 240 C. The electrical conductivity decreased slightly following irradiation, due to the presence of defect clusters and Ni, Zn, Co transmutation products. Considering also previously published fracture toughness data, this indicates that CuNiBe alloys have irradiated tensile and electrical properties comparable or superior to CuCrZr and oxide dispersion strengthened copper at temperatures <250 C, and may be an attractive

  6. The impact of medication adherence on coronary artery disease costs and outcomes: a systematic review.

    PubMed

    Bitton, Asaf; Choudhry, Niteesh K; Matlin, Olga S; Swanton, Kellie; Shrank, William H

    2013-04-01

    Given the huge burden of coronary artery disease and the effectiveness of medication therapy, understanding and quantifying known impacts of poor medication adherence for primary and secondary prevention is crucial. We sought to systematically review the literature on this topic area with a focus on quantified cost and clinical outcomes related to adherence. We conducted a systematic review of the literature between 1966 and November 2011 using a fixed search strategy, multiple reviewers, and a quality rating scale. We found 2636 articles using this strategy, eventually weaning them down to 25 studies that met our inclusion criteria. Three reviewers independently reviewed the studies and scored them for quality using the Newcastle Ottawa Scoring Scale. We found 5 studies (4 of which focused on statins) that measured the impact of medication adherence on primary prevention of coronary artery disease and 20 articles that focused on the relationship between medication adherence to costs and outcomes related to secondary prevention of coronary artery disease. Most of these latter studies focused on antihypertensive medications and aspirin. All controlled for confounding comorbidities and sociodemographic characteristics, but few controlled for likelihood of adherent patients to have healthier behaviors ("healthy adherer effect"). Three studies found that high adherence significantly improves health outcomes and reduces annual costs for secondary prevention of coronary artery disease (between $294 and $868 per patient, equating to 10.1%-17.8% cost reductions between high- and low-adherence groups). The studies were all of generally of high quality on the Newcastle Ottawa Scale (median score 8 of 9). Increased medication adherence is associated with improved outcomes and reduced costs, but most studies do not control for a "healthy adherer" effect. Copyright © 2013 Elsevier Inc. All rights reserved.

  7. Medication adherence to oral anticancer drugs: systematic review.

    PubMed

    Huang, Wen-Chuan; Chen, Chung-Yu; Lin, Shun-Jin; Chang, Chao-Sung

    2016-01-01

    Many studies have demonstrated that non-adherence to oral anticancer drugs (OACDs) has challenged treatment efficacy. Otherwise, few validated tools exist to measure patients' adherence to medication regimen in clinical practice. To synthesize previous studies on adherence by cancer patients taking OACDs, especially in targeted therapy, a systematic search of several electronic databases was conducted. We analyzed existing scales' contents for various cancer patients and outcomes of studies assessing adherence. However, a well-validated scale designed particularly for OACD adherence is still lacking. Most adherence scales used in the studies reviewed contain items focused on measuring patients' medication-taking behavior more than their barriers to medication compliance and beliefs. However, non-adherence to OACDs is a complex phenomenon, and drug-taking barriers and patient beliefs significantly affect patients' non-adherence. To understand the key drivers and predisposing factors for non-adherence, we need to develop a well-validated, multidimensional scale.

  8. High-intensity interval and moderate-intensity continuous training elicit similar enjoyment and adherence levels in overweight and obese adults.

    PubMed

    Vella, Chantal A; Taylor, Katrina; Drummer, Devin

    2017-10-01

    High-intensity interval training (HIIT) has been shown to improve cardiometabolic health during supervised lab-based studies but adherence, enjoyment, and health benefits of HIIT performed independently are yet to be understood. We compared adherence, enjoyment, and cardiometabolic outcomes after 8 weeks of HIIT or moderate-intensity continuous training (MICT), matched for energy expenditure, in overweight and obese young adults. 17 adults were randomized to HIIT or MICT. After completing 12 sessions of supervised training over 3 weeks, participants were asked to independently perform HIIT or MICT for 30 min, 4 times/week for 5 weeks. Cardiometabolic outcomes included cardiorespiratory fitness (VO2 peak), lipids, and inflammatory markers. Exercise enjoyment was measured by the validated Physical Activity Enjoyment Scale. Exercise adherence (93.4 ± 3.1% vs. 93.1 ± 3.7%, respectively) and mean enjoyment across the intervention (100.1 ± 4.3 vs. 100.3 ± 4.4, respectively) were high, with no differences between HIIT and MICT (p > .05). Similarly, enjoyment levels did not change over time in either group (p > .05). After training, HIIT exhibited a greater decrease in low-density lipoprotein cholesterol than MICT (-0.66 mmol L(-1) vs. -0.03 mmol L(-1), respectively) and a greater increase in VO2 peak than MICT (p < .05, +2.6 mL kg min(-1) vs. +0.4 mL kg min(-1), respectively). Interleukin-6 and C-reactive protein increased in HIIT (+0.5 pg mL(-1) and + 31.4 nmol L(-1), respectively) and decreased in MICT (-0.6 pg mL(-1) and -6.7 nmol L(-1), respectively, p < .05). Our novel findings suggest that HIIT is enjoyable and has high unsupervised adherence rates in overweight and obese adults. However, HIIT may be associated with an increase in inflammation with short-term exercise in this population.

  9. Ultrahigh Oxidation Resistance and High Electrical Conductivity in Copper-Silver Powder.

    PubMed

    Li, Jiaxiang; Li, Yunping; Wang, Zhongchang; Bian, Huakang; Hou, Yuhang; Wang, Fenglin; Xu, Guofu; Liu, Bin; Liu, Yong

    2016-12-22

    The electrical conductivity of pure Cu powder is typically deteriorated at elevated temperatures due to the oxidation by forming non-conducting oxides on surface, while enhancing oxidation resistance via alloying is often accompanied by a drastic decline of electrical conductivity. Obtaining Cu powder with both a high electrical conductivity and a high oxidation resistance represents one of the key challenges in developing next-generation electrical transferring powder. Here, we fabricate a Cu-Ag powder with a continuous Ag network along grain boundaries of Cu particles and demonstrate that this new structure can inhibit the preferential oxidation in grain boundaries at elevated temperatures. As a result, the Cu-Ag powder displays considerably high electrical conductivity and high oxidation resistance up to approximately 300 °C, which are markedly higher than that of pure Cu powder. This study paves a new pathway for developing novel Cu powders with much enhanced electrical conductivity and oxidation resistance in service.

  10. Ultrahigh Oxidation Resistance and High Electrical Conductivity in Copper-Silver Powder

    NASA Astrophysics Data System (ADS)

    Li, Jiaxiang; Li, Yunping; Wang, Zhongchang; Bian, Huakang; Hou, Yuhang; Wang, Fenglin; Xu, Guofu; Liu, Bin; Liu, Yong

    2016-12-01

    The electrical conductivity of pure Cu powder is typically deteriorated at elevated temperatures due to the oxidation by forming non-conducting oxides on surface, while enhancing oxidation resistance via alloying is often accompanied by a drastic decline of electrical conductivity. Obtaining Cu powder with both a high electrical conductivity and a high oxidation resistance represents one of the key challenges in developing next-generation electrical transferring powder. Here, we fabricate a Cu-Ag powder with a continuous Ag network along grain boundaries of Cu particles and demonstrate that this new structure can inhibit the preferential oxidation in grain boundaries at elevated temperatures. As a result, the Cu-Ag powder displays considerably high electrical conductivity and high oxidation resistance up to approximately 300 °C, which are markedly higher than that of pure Cu powder. This study paves a new pathway for developing novel Cu powders with much enhanced electrical conductivity and oxidation resistance in service.

  11. Ultrahigh Oxidation Resistance and High Electrical Conductivity in Copper-Silver Powder

    PubMed Central

    Li, Jiaxiang; Li, Yunping; Wang, Zhongchang; Bian, Huakang; Hou, Yuhang; Wang, Fenglin; Xu, Guofu; Liu, Bin; Liu, Yong

    2016-01-01

    The electrical conductivity of pure Cu powder is typically deteriorated at elevated temperatures due to the oxidation by forming non-conducting oxides on surface, while enhancing oxidation resistance via alloying is often accompanied by a drastic decline of electrical conductivity. Obtaining Cu powder with both a high electrical conductivity and a high oxidation resistance represents one of the key challenges in developing next-generation electrical transferring powder. Here, we fabricate a Cu-Ag powder with a continuous Ag network along grain boundaries of Cu particles and demonstrate that this new structure can inhibit the preferential oxidation in grain boundaries at elevated temperatures. As a result, the Cu-Ag powder displays considerably high electrical conductivity and high oxidation resistance up to approximately 300 °C, which are markedly higher than that of pure Cu powder. This study paves a new pathway for developing novel Cu powders with much enhanced electrical conductivity and oxidation resistance in service. PMID:28004839

  12. Interplay between Oral Hypoglycemic Medication Adherence and Quality of Life among Elderly Type 2 Diabetes Mellitus Patients

    PubMed Central

    Manan, Mohamed Mansor; Husin, Akhma Radzuanna; Alkhoshaiban, Ali Saleh; Al-Worafi, Yaser Mohammed Ali

    2014-01-01

    Background: Adherence to medications is an important factor that contributes to therapeutic success. With the current increase in the elderly population, information relating to adherence to treatment and quality of life (QoL) of diabetic elderly patients will help the healthcare provider to improve their treatment. Thus, this study aims to determine the factors affecting adherence to medications and the consequence of non adherence to QoL. Materials and Methods: This was a cross-sectional study using validated Morisky Medication Adherence Scale (MMAS) Questionnaire. This study was conducted to assess the level of adherence on oral hypoglycemic medications (OHM) and quality of life of the Type 2 diabetes mellitus (T2DM) elderly patients in an urban health centre in Malaysia. A retrospective medication record review was also conducted to collect and confirm data on patients’ demographics, diagnosis, treatments, and outcomes. Results: One hundred and seventy nine patients were recruited in this study. Median adherence score was 7.75 (IQR 6.50- 8.00). Good adherer was observed in 48.00% of the participants. A Chi-square test indicated significant correlation between adherence and HbA1c (p= 0.010). The mean elderly diabetes mellitus Problem Areas in Diabetes (PAID) score was 6.30 ±SD 8.50. A significant inversed association was observed between PAID score and the level of adherence (r = - 0.175, p< 0.05). A highly significant difference in the low adherence group (p = 0.002). PAID score significantly correlated with age (years), female gender and HbA1c (p <0.05). A negative association between HbA1c levels and adherence was identified where a 1% increase in HbA1c was associated with a 30% decrease in the likelihood of being adherent. Conclusion: A medication adherence rate of 48% was obtained among elderly T2DM patients treated in the primary care clinic. This study showed that HbA1c is a relevant tool to assess patient glycemic control and adherence

  13. Treatment effect, adherence, and safety of high fluid intake for the prevention of incident and recurrent kidney stones: a systematic review and meta-analysis.

    PubMed

    Cheungpasitporn, Wisit; Rossetti, Sandro; Friend, Keith; Erickson, Stephen B; Lieske, John C

    2016-04-01

    The objective of this systematic review and meta-analysis were to evaluate the effectiveness of high fluid intake for the prevention of incident and recurrent kidney stones, as well as its adherence and safety. A literature search was performed encompassing 1980 through July 2014. Studies that reported relative risks, odds ratios, or hazard ratios comparing the risk of kidney stone events in patients with high vs inadequate fluid intake were included. Pooled risk ratios (RRs) and 95 % confidence intervals (CIs) were calculated using a random-effect, generic inverse variance method. Nine studies [2 randomized controlled trials (RCTs) with 269 patients; 7 observational studies with 273,685 individuals] were included in the meta-analysis. Pooled RRs of kidney stones in individuals with high-fluid intake were 0.40 (95 % CI 0.20-0.79) and 0.49 (0.34-0.71) in RCTs and observational studies, respectively. High fluid intake was significantly associated with reduced risk of recurrent kidney stones: RRs 0.40 (95 % CI 0.20-0.79) and 0.20 (0.09-0.44) in RCTs and observational studies, respectively. Adherence and safety data on high fluid intake treatment were limited; 1 RCT reported no withdrawals due to adverse events. This analysis demonstrated a significantly reduced risk of incident kidney stones among individuals with high fluid consumption. High fluid consumption also reduced the risk of recurrent kidney stones. Furthermore, the magnitude of risk reduction was high. Although increased water intake appears to be safe, future studies on its safety in patients with high risk of volume overload or hyponatremia may be indicated.

  14. Highly Conductive Aromatic Functionalized Multi-Walled Carbon Nanotube for Inkjet Printable High Performance Supercapacitor Electrodes

    PubMed Central

    Attri, Pankaj

    2015-01-01

    We report the functionalization of multiwalled carbon nanotubes (MWCNT) via the 1,3-dipolar [3+2] cycloaddition of aromatic azides, which resulted in a detangled CNT as shown by transmission electron microscopy (TEM). Carboxylic moieties (-COOH) on aromatic azide result in highly stable aqueous dispersion (max. conc. ~ 10 mg/mL H2O), making the suitable for inkjet printing. Printed patterns on polyethylene terephthalate (PET) flexible substrate exhibit low sheet resistivity ~65 Ω. cm, which is attributed to enhanced conductivity. Fabricated Supercapacitors (SC) assembled using these printed substrates exhibit good electrochemical performance in organic as well as aqueous electrolytes. High energy and power density (57.8 Wh/kg and 0.85 kW/kg) in 1M H2SO4 aqueous electrolyte demonstrate the excellent performance of the proposed supercapacitor. Capacitive retention varies from ~85–94% with columbic efficiency ~95% after 1000 charge/discharge cycles in different electrolytes, demonstrating the excellent potential of the device for futuristic power applications. PMID:26153688

  15. High Transparent Conductive Aluminum-Doped Zinc Oxide Thin Films by Reactive Co-Sputtering (Postprint)

    DTIC Science & Technology

    2016-03-30

    AFRL-RX-WP-JA-2017-0144 HIGH TRANSPARENT CONDUCTIVE ALUMINUM - DOPED ZINC OXIDE THIN FILMS BY REACTIVE CO- SPUTTERING (POSTPRINT...TRANSPARENT CONDUCTIVE ALUMINUM -DOPED ZINC OXIDE THIN FILMS BY REACTIVE CO-SPUTTERING (POSTPRINT) 5a. CONTRACT NUMBER FA8650-16-D-5402-0001 5b. GRANT...ANSI Std. Z39-18 TD.11.pdf Optical Interference Coatings (OIC) 2016 © OSA 2016 1 High Transparent Conductive Aluminum -doped Zinc Oxide Thin

  16. Improved outcomes with European Society of Cardiology guideline-adherent antithrombotic treatment in high-risk patients with atrial fibrillation: a report from the EORP-AF General Pilot Registry.

    PubMed

    Lip, Gregory Y H; Laroche, Cécile; Popescu, Mircea Iaochim; Rasmussen, Lars Hvilsted; Vitali-Serdoz, Laura; Dan, Gheorghe-Andrei; Kalarus, Zbigniew; Crijns, Harry J G M; Oliveira, Mario Martins; Tavazzi, Luigi; Maggioni, Aldo P; Boriani, Giuseppe

    2015-12-01

    Guideline-adherent therapy for stroke prevention in atrial fibrillation has been associated with better outcomes, in terms of thromboembolism (TE) and bleeding. In this report from the EuroObservational Research Programme-Atrial Fibrillation (EORP-AF) Pilot General Registry, we describe the associated baseline features of 'high risk' AF patients in relation to guideline-adherent antithrombotic treatment, i.e. whether they were adherent, over-treated, or under-treated based on the 2012 European Society of Cardiology (ESC) guidelines. Secondly, we assessed the predictors of guideline-adherent antithrombotic treatment. Thirdly, we evaluated outcomes for all-cause mortality, TE, bleeding, and the composite endpoint of 'any TE, cardiovascular death or bleeding' in relation to whether they were ESC guideline-adherent treatment. From the EORP-AF cohort, the follow-up dataset of 2634 subjects was used to assess the impact of guideline adherence or non-adherence. Of these, 1602 (60.6%) were guideline adherent, whilst 458 (17.3%) were under-treated, and 574 (21.7%) were over-treated. Non-guideline-adherent treatment can be related to region of Europe as well as associated clinical features, but not age, AF type, symptoms, or echocardiography indices. Over-treatment per se was associated with symptoms, using the EHRA score, as well as other comorbidities. Guideline-adherent antithrombotic management based on the ESC guidelines is associated with significantly better outcomes. Specifically, the endpoint of 'all cause death and any TE' is increased by >60% by undertreatment [hazard ratio (HR) 1.679 (95% confidence interval (CI) 1.202-2.347)] or over-treatment [HR 1.622 (95% CI 1.173-2.23)]. For the composite endpoint of 'cardiovascular death, any TE or bleeding', over-treatment increased risk by >70% [HR 1.722 (95% CI 1.200-2.470)]. Even in this cohort with high overall rates of oral anticoagulation use, ESC guideline-adherent antithrombotic management is associated with

  17. High adherence to a neuromuscular injury prevention programme (FIFA 11+) improves functional balance and reduces injury risk in Canadian youth female football players: a cluster randomised trial.

    PubMed

    Steffen, Kathrin; Emery, Carolyn A; Romiti, Maria; Kang, Jian; Bizzini, Mario; Dvorak, Jiri; Finch, Caroline F; Meeuwisse, Willem H

    2013-08-01

    A protective effect on injury risk in youth sports through neuromuscular warm-up training routines has consistently been demonstrated. However, there is a paucity of information regarding the quantity and quality of coach-led injury prevention programmes and its impact on the physical performance of players. The aim of this cluster-randomised controlled trial was to assess whether different delivery methods of an injury prevention programme (FIFA 11+) to coaches could improve player performance, and to examine the effect of player adherence on performance and injury risk. During the 2011 football season (May-August), coaches of 31 tiers 1-3 level teams were introduced to the 11+ through either an unsupervised website or a coach-focused workshop with and without additional on-field supervisions. Playing exposure, adherence to the 11+, and injuries were recorded for female 13-year-old to 18-year-old players. Performance testing included the Star Excursion Balance Test (SEBT), single-leg balance, triple hop and jumping-over-a-bar tests. Complete preseason and postseason performance tests were available for 226 players (66.5%). Compared to the unsupervised group, single-leg balance (OR=2.8; 95% CI 1.1 to 4.6) and the anterior direction of the SEBT improved significantly in the onfield supervised group of players (OR=4.7; 95% CI 2.2 to 7.1), while 2-leg jumping performance decreased (OR=-5.1; 95% CI -9.9 to -0.2). However, significant improvements in 5 of 6 reach distances in the SEBT were found, favouring players who highly adhered to the 11+. Also, injury risk was lower for those players (injury rate ratio, IRR=0.28, 95% CI 0.10 to 0.79). Different delivery methods of the FIFA 11+ to coaches influenced players' physical performance minimally. However, high player adherence to the 11+ resulted in significant improvements in functional balance and reduced injury risk.

  18. Short-term garlic supplementation and highly active antiretroviral treatment adherence, CD4+ cell counts, and human immunodeficiency virus viral load.

    PubMed

    Liu, Chenglong; Wang, Cuiwei; Robison, Esther; Levine, Alexandra M; Gandhi, Monica; Schwartz, Rebecca; Weber, Kathleen M; Merenstein, Daniel

    2012-01-01

    Human immunodeficiency virus (HIV)-infected individuals frequently have consumed garlic, a popular complementary supplement. Researchers rarely have studied garlic's association with antiretroviral therapies, however, even though that association is very relevant clinically. To examine associations of supplemental use of garlic with highly active antiretroviral treatment (HAART) adherence level and HAART effectiveness (HIV viral load and CD4+ cell counts) in HIV-infected women. The research team carried out a self-controlled, longitudinal study nested within the Women's Interagency HIV Study (WIHS). The team used a paired study design that allowed participants to serve as their own controls. The team first identified all of the studies visits in which the participant self-reported the use of a garlic supplement since her last visit (index visit). Then for each index visit, the team identified a matching visit (a control visit) using the following criteria: (a) the visit must be one for the same participant in which that participant reported no garlic supplementation; (b) the visit must immediately precede the index visit (less than 1 year apart); and (c) at the time of the control visit, the participant must have been using antiretroviral therapy identical to that used at the time of the index visit. Participants were persons using garlic supplementation who already were participants in the WIHS. The research team used a logistic regression model to examine the association between garlic supplementation and HAART adherence level. The team used a mixed linear model to examine the association of garlic supplementation with HIV viral load and CD4+ cell counts. From October 1994 to April 2009, 390 HIV-infected women in the WIHS made 1112 visits at which they reported using garlic supplements. Seventy-seven HIV-infected women using HAART met the research teams selection criteria and contributed 99 pairs of visits for the study. Among the women who used garlic

  19. Short-term Garlic Supplementation and Highly Active Antiretroviral Treatment Adherence, CD4+ Cell Counts, and Human Immunodeficiency Virus Viral Load

    PubMed Central

    Liu, Chenglong; Wang, Cuiwei; Robison, Esther; Levine, Alexandra M.; Gandhi, Monica; Schwartz, Rebecca; Weber, Kathleen M.; Merenstein, Daniel

    2012-01-01

    Context Human immunodeficiency virus (HIV)–infected individuals frequently have consumed garlic, a popular complementary supplement. Researchers rarely have studied garlic’s association with antiretroviral therapies, however, even though that association is very relevant clinically. Objective To examine associations of supplemental use of garlic with highly active antiretroviral treatment (HAART) adherence level and HAART effectiveness (HIV viral load and CD4+ cell counts) in HIV-infected women. Design The research team carried out a self-controlled, longitudinal study nested within the Women’s Interagency HIV Study (WIHS). The team used a paired study design that allowed participants to serve as their own controls. The team first identified all of the study’s visits in which the participant self-reported the use of a garlic supplement since her last visit (index visit). Then for each index visit, the team identified a matching visit (a control visit) using the following criteria: (a) the visit must be one for the same participant in which that participant reported no garlic supplementation; (b) the visit must immediately precede the index visit (less than 1 year apart); and (c) at the time of the control visit, the participant must have been using antiretroviral therapy identical to that used at the time of the index visit. Participants Participants were persons using garlic supplementation who already were participants in the WIHS. Outcome Measures The research team used a logistic regression model to examine the association between garlic supplementation and HAART adherence level. The team used a mixed linear model to examine the association of garlic supplementation with HIV viral load and CD4+ cell counts. Results From October 1994 to April 2009, 390 HIV-infected women in the WIHS made 1112 visits at which they reported using garlic supplements. Seventy-seven HIV-infected women using HAART met the research team’s selection criteria and contributed 99

  20. Adherence to Antihypertensive Therapy.

    PubMed

    Peacock, Erin; Krousel-Wood, Marie

    2017-01-01

    Adherence to antihypertensive medication remains a key modifiable factor in the management of hypertension. The multidimensional nature of adherence and blood pressure (BP) control call for multicomponent, patient-centered interventions to improve adherence. Promising strategies to improve antihypertensive medication adherence and BP control include regimen simplification, reduction of out-of-pocket costs, use of allied health professionals for intervention delivery, and self-monitoring of BP. Research to understand the effects of technology-mediated interventions, mechanisms underlying adherence behavior, and sex-race differences in determinants of low adherence and intervention effectiveness may enhance patient-specific approaches to improve adherence and disease control. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Psychological factors predict adherence to methotrexate in rheumatoid arthritis; findings from a systematic review of rates, predictors and associations with patient-reported and clinical outcomes

    PubMed Central

    Bluett, James; Barton, Anne; Hyrich, Kimme L; Cordingley, Lis; Verstappen, Suzanne M M

    2016-01-01

    Treatment response to methotrexate (MTX) for rheumatoid arthritis (RA) is not universal and non-adherence may partially explain this. The aims of this systematic review were to: (1) summarise existing rates of adherence to MTX, (2) identify predictors of adherence to MTX, and (3) assess the association between non-adherence and patient outcomes. The authors conducted a systematic search of papers published from January 1980 to February 2015 in PubMed, PsycINFO, EMBASE and CINAHL databases. Studies were eligible for inclusion if: (1) MTX was used as monotherapy or in combination with other therapies, (2) MTX was used in an RA or inflammatory polyarthritis population, (3) adherence was defined and measured as the extent to which patients followed their MTX regimen during the period of prescription, and (4) it was an original piece of research. In total, 10 studies met the inclusion criteria and 8 were evaluated as high quality. Rates of adherence ranged from 59% to 107%, and exposed differences in definitions of adherence, study methodologies and sample heterogeneity. A number of potential predictors of MTX adherence were identified; the strongest being related to beliefs in the necessity and efficacy of MTX, absence of low mood, mild disease and MTX monotherapy. Furthermore, 3 studies tested the association of adherence with disease activity as an outcome measure; all 3 found non-adherence associated with poor treatment response. This systematic review shows the importance of adherence to MTX treatment and summarises the associated modifiable factors. PMID:26848403

  2. Interventions to improve adherence to inhaled steroids for asthma.

    PubMed

    Normansell, Rebecca; Kew, Kayleigh M; Stovold, Elizabeth

    2017-04-18

    priori assumptions about how trials would be categorised but conducted meta-analyses only if treatments, participants and the underlying clinical question were similar enough for pooling to make sense. We included 39 parallel randomised controlled trials (RCTs) involving adults and children with asthma, 28 of which (n = 16,303) contributed data to at least one meta-analysis. Follow-up ranged from two months to two years (median six months), and trials were conducted mainly in high-income countries. Most studies reported some measure of adherence to ICS and a variety of other outcomes such as quality of life and asthma control. Studies generally were at low or unclear risk of selection bias and at high risk of biases associated with blinding. We considered around half the studies to be at high risk for attrition bias and selective outcome reporting.We classified studies into four comparisons: adherence education versus control (20 studies); electronic trackers or reminders versus control (11 studies); simplified drug regimens versus usual drug regimens (four studies); and school-based directly observed therapy (three studies). Two studies are described separately.All pooled results for adherence education, electronic trackers or reminders and simplified regimens showed better adherence than controls. Analyses limited to studies using objective measures revealed that adherence education showed a benefit of 20 percentage points over control (95% confidence interval (CI) 7.52 to 32.74; five studies; low-quality evidence); electronic trackers or reminders led to better adherence of 19 percentage points (95% CI 14.47 to 25.26; six studies; moderate-quality evidence); and simplified regimens led to better adherence of 4 percentage points (95% CI 1.88 to 6.16; three studies; moderate-quality evidence). Our confidence in the evidence was reduced by risk of bias and inconsistency.Improvements in adherence were not consistently translated into observable benefit for clinical

  3. Facile Method to Fabricate Highly Thermally Conductive Graphite/PP Composite with Network Structures.

    PubMed

    Feng, Changping; Ni, Haiying; Chen, Jun; Yang, Wei

    2016-08-03

    Thermally conductive polymer composites have aroused significant academic and industrial interest for several decades. Herein, we report a novel fabrication method of graphite/polypropylene (PP) composites with high thermal conductivity in which graphite flakes construct a continuous thermally conductive network. The thermal conductivity coefficient of the graphite/PP composites is markedly improved to be 5.4 W/mK at a graphite loading of 21.2 vol %. Such a great improvement of the thermal conductivity is ascribed to the occurrence of orientations of crystalline graphite flakes with large particles around PP resin particles and the formation of a perfect thermally conductive network. The model of Hashin-Shtrikman (HS) is adopted to interpret the outstanding thermally conductive property of the graphite/PP composites. This work provides a guideline for the easy fabrication of thermally conductive composites with network structures.

  4. Directly patternable, highly conducting polymers for broad applications in organic electronics.

    PubMed

    Yoo, Joung Eun; Lee, Kwang Seok; Garcia, Andres; Tarver, Jacob; Gomez, Enrique D; Baldwin, Kimberly; Sun, Yangming; Meng, Hong; Nguyen, Thuc-Quyen; Loo, Yueh-Lin

    2010-03-30

    Postdeposition solvent annealing of water-dispersible conducting polymers induces dramatic structural rearrangement and improves electrical conductivities by more than two orders of magnitude. We attain electrical conductivities in excess of 50 S/cm when polyaniline films are exposed to dichloroacetic acid. Subjecting commercially available poly(ethylene dioxythiophene) to the same treatment yields a conductivity as high as 250 S/cm. This process has enabled the wide incorporation of conducting polymers in organic electronics; conducting polymers that are not typically processable can now be deposited from solution and their conductivities subsequently enhanced to practical levels via a simple and straightforward solvent annealing process. The treated conducting polymers are thus promising alternatives for metals as source and drain electrodes in organic thin-film transistors as well as for transparent metal oxide conductors as anodes in organic solar cells and light-emitting diodes.

  5. Pulling on adhered vesicles

    NASA Astrophysics Data System (ADS)

    Smith, Ana-Suncana; Goennenwein, Stefanie; Lorz, Barbara; Seifert, Udo; Sackmann, Erich

    2004-03-01

    , E. Sackmann, U. Seifert: Pulling tethers from adhered vesicles, submitted for publication. 3. S. Goennenwein, A.-S. Smith, B. Lorz, E. Sackmann: Unbinding of specifically adhered vesicles: Comparison of systems with high and low adhesion affinities, submitted for publication. 4. A.-S. Smith, S. Goennenwein, , B. Lorz, U. Seifert, E. Sackmann: Pulling on adhered vesicles: Comparison of theory and experiment, submitted for publication.

  6. Mechanical ventilation weaning protocol improves medical adherence and results.

    PubMed

    Borges, Luís Guilherme Alegretti; Savi, Augusto; Teixeira, Cassiano; de Oliveira, Roselaine Pinheiro; De Camillis, Marcio Luiz Ferreira; Wickert, Ricardo; Brodt, Sérgio Fernando Monteiro; Tonietto, Túlio Frederico; Cremonese, Ricardo; da Silva, Leonardo Silveira; Gehm, Fernanda; Oliveira, Eubrando Silvestre; Barth, Jose Herve Diel; Macari, Juçara Gasparetto; de Barros, Cíntia Dias; Vieira, Sílvia Regina Rios

    2017-10-01

    Implementation of a weaning protocol is related to better patient prognosis. However, new approaches may take several years to become the standard of care in daily practice. We conducted a prospective cohort study to investigate the effectiveness of a multifaceted strategy to implement a protocol to wean patients from mechanical ventilation (MV) and to evaluate the weaning success rate as well as practitioner adherence to the protocol. We investigated all consecutive MV-dependent subjects admitted to a medical-surgical intensive care unit (ICU) for >24h over 7years. The multifaceted strategy consisted of continuing education of attending physicians and ICU staff and regular feedback regarding patient outcomes. The study was conducted in three phases: protocol development, protocol and multifaceted strategy implementation, and protocol monitoring. Data regarding weaning outcomes and physician adherence to the weaning protocol were collected during all phases. We enrolled 2469 subjects over 7years, with 1,943 subjects (78.7%) experiencing weaning success. Physician adherence to the protocol increased during the years of protocol and multifaceted strategy implementation (from 38% to 86%, p<0.01) and decreased in the protocol monitoring phase (from 73.9% to 50.0%, p<0.01). However, during the study years, the weaning success of all subjects increased (from 73.1% to 85.4%, p<0.001). When the weaning protocol was evaluated step-by-step, we found high adherence for noninvasive ventilation use (95%) and weaning predictor measurement (91%) and lower adherence for control of fluid balance (57%) and daily interruption of sedation (24%). Weaning success was higher in patients who had undergone the weaning protocol compared to those who had undergone weaning based in clinical practice (85.6% vs. 67.7%, p<0.001). A multifaceted strategy consisting of continuing education and regular feedback can increase physician adherence to a weaning protocol for mechanical ventilation

  7. Enjoyment for High-Intensity Interval Exercise Increases during the First Six Weeks of Training: Implications for Promoting Exercise Adherence in Sedentary Adults.

    PubMed

    Heisz, Jennifer J; Tejada, Mary Grace M; Paolucci, Emily M; Muir, Cameron

    2016-01-01

    This is the first study to show that enjoyment for high-intensity interval exercise increases with chronic training. Prior acute studies typically report high-intensity interval training (HIT) as being more enjoyable than moderate continuous training (MCT) unless the high-intensity intervals are too strenuous or difficult to complete. It follows that exercise competency may be a critical factor contributing to the enjoyment of HIT, and therefore building competency through chronic training may be one way to increase its enjoyment. To test this, we randomly assigned sedentary young adults to six weeks of HIT or MCT, and tracked changes in their enjoyment for the exercise. Enjoyment for HIT increased with training whereas enjoyment for MCT remained constant and lower. Changes in exercise enjoyment were predicted by increases in workload, suggesting that strength adaptions may be important for promoting exercise enjoyment. The results point to HIT as a promising protocol for promoting exercise enjoyment and adherence in sedentary young adults.

  8. How Presentation of Drug Detection Results Changed Reports of Product Adherence in South Africa, Uganda and Zimbabwe.

    PubMed

    Musara, Petina; Montgomery, Elizabeth T; Mgodi, Nyaradzo M; Woeber, Kubashni; Akello, Carolyne A; Hartmann, Miriam; Cheng, Helen; Levy, Lisa; Katz, Ariana; Grossman, Cynthia I; Chirenje, Z Mike; van der Straten, Ariane; Mensch, Barbara

    2017-01-21

    Accurate estimates of study product use are critical to understanding and addressing adherence challenges in HIV prevention trials. The VOICE trial exposed a significant gap between self-reported adherence and drug detection. The VOICE-D qualitative study was designed to better understand non-adherence during VOICE, and was conducted in 2 stages: before (stage 1) and after (stage 2) drug detection results were provided to participants. Transcripts from 44 women who participated in both stages were analysed to understand the effect of presenting drug detection data on narratives of product use. Thirty-six women reported high adherence in stage 1, yet admitted non-use in stage 2, three reported high adherence in both stages (contrary to their drug detection results) and five had consistent responses across both stages and drug results. Presenting objective measures of use may facilitate more accurate product use reporting and should be evaluated in future prevention trials.

  9. High-frequency conductivity of multilayer graphene and graphite under the conditions of quantum cyclotron resonance

    NASA Astrophysics Data System (ADS)

    Kozlov, I. V.; Medina Pantoja, J. C.

    2014-06-01

    The conductivity tensor of a layered conductor with the Dirac-type energy spectrum of charge carriers placed in a quantizing magnetic field under the condition of normal skin-effect is investigated using the method of quantum kinetic equation. It is shown that under the cyclotron resonance conditions there appear high-temperature quantum oscillations of conductivity, which are weakly sensitive to thermal broadening of the Fermi level. We present the expressions for the classical and high-temperature contributions to the conductivity tensor which determine the conductivity in the range of not too low temperatures where the Shubnikov-de Haas oscillations are vanishing.

  10. Multiscale modeling of thermal conductivity of high burnup structures in UO2 fuels

    SciTech Connect

    Bai, Xian -Ming; Tonks, Michael R.; Zhang, Yongfeng; Hales, Jason D.

    2015-12-22

    The high burnup structure forming at the rim region in UO2 based nuclear fuel pellets has interesting physical properties such as improved thermal conductivity, even though it contains a high density of grain boundaries and micron-size gas bubbles. To understand this counterintuitive phenomenon, mesoscale heat conduction simulations with inputs from atomistic simulations and experiments were conducted to study the thermal conductivities of a small-grain high burnup microstructure and two large-grain unrestructured microstructures. We concluded that the phonon scattering effects caused by small point defects such as dispersed Xe atoms in the grain interior must be included in order to correctly predict the thermal transport properties of these microstructures. In extreme cases, even a small concentration of dispersed Xe atoms such as 10-5 can result in a lower thermal conductivity in the large-grain unrestructured microstructures than in the small-grain high burnup structure. The high-density grain boundaries in a high burnup structure act as defect sinks and can reduce the concentration of point defects in its grain interior and improve its thermal conductivity in comparison with its large-grain counterparts. Furthermore, an analytical model was developed to describe the thermal conductivity at different concentrations of dispersed Xe, bubble porosities, and grain sizes. Upon calibration, the model is robust and agrees well with independent heat conduction modeling over a wide range of microstructural parameters.

  11. Multiscale modeling of thermal conductivity of high burnup structures in UO2 fuels

    DOE PAGES

    Bai, Xian -Ming; Tonks, Michael R.; Zhang, Yongfeng; ...

    2015-12-22

    The high burnup structure forming at the rim region in UO2 based nuclear fuel pellets has interesting physical properties such as improved thermal conductivity, even though it contains a high density of grain boundaries and micron-size gas bubbles. To understand this counterintuitive phenomenon, mesoscale heat conduction simulations with inputs from atomistic simulations and experiments were conducted to study the thermal conductivities of a small-grain high burnup microstructure and two large-grain unrestructured microstructures. We concluded that the phonon scattering effects caused by small point defects such as dispersed Xe atoms in the grain interior must be included in order to correctlymore » predict the thermal transport properties of these microstructures. In extreme cases, even a small concentration of dispersed Xe atoms such as 10-5 can result in a lower thermal conductivity in the large-grain unrestructured microstructures than in the small-grain high burnup structure. The high-density grain boundaries in a high burnup structure act as defect sinks and can reduce the concentration of point defects in its grain interior and improve its thermal conductivity in comparison with its large-grain counterparts. Furthermore, an analytical model was developed to describe the thermal conductivity at different concentrations of dispersed Xe, bubble porosities, and grain sizes. Upon calibration, the model is robust and agrees well with independent heat conduction modeling over a wide range of microstructural parameters.« less

  12. High performance heat curing copper-silver powders filled electrically conductive adhesives

    NASA Astrophysics Data System (ADS)

    Cui, Hui-Wang; Jiu, Jin-Ting; Sugahara, Tohru; Nagao, Shijo; Suganuma, Katsuaki; Uchida, Hiroshi

    2015-03-01

    In this study, high performance electrically conductive adhesives were fabricated from a vinyl ester resin, a thermal initiator, silver coated copper powders, and pure silver powders, without using any other coupling agent, dispersing agent, and reducing agent. The heat cured copper-silver powders filled electrically conductive adhesives presented low bulk resistivity (e.g., 4.53 × 10-5 Ω·cm) due to the silver powders that had given high electrical conductivity to the adhesives, and high shear strength (e.g., 16.22 MPa) provided by the crosslinked structures of vinyl ester resin. These high performance copper-silver powders filled electrically conductive adhesives have lower cost than those filled by pure silver powders, which can be well used in the electronic packaging and can enlarge the application prospects of electrically conductive adhesives. [Figure not available: see fulltext.

  13. Factors influencing adherence in CML and ways to improvement: Results of a patient-driven survey of 2546 patients in 63 countries.

    PubMed

    Geissler, Jan; Sharf, Giora; Bombaci, Felice; Daban, Mina; De Jong, Jan; Gavin, Tony; Pelouchova, Jana; Dziwinski, Euzebiusz; Hasford, Joerg; Hoffmann, Verena Sophia

    2017-07-01

    Optimal adherence to CML therapy is of key importance to maximize treatment effectiveness. Two clinical studies (ADAGIO and Hammersmith) have proven a clear correlation between adherence and achieving optimal treatment response and have revealed that non-adherence is common in CML patients (Marin et al. in J Clin Oncol 28(24):2381-2388, 2010, Noens et al. in Haematologica 99(33):437-447, 2014). The aim of this study is to assess the extent of suboptimal adherence and to investigate motivations and behavioural patterns of adherence in a worldwide patient sample. Questionnaires were provided by the CML Advocates Network and were filled in by patients online and offline. Patient characteristics, treatment and motivations were collected. Adherence was assessed by the 8-item Morisky Medication Adherence scale. Logistic regression models were fitted to investigate the influence of different factors on adherence. Overall, 2 546 questionnaires from 63 countries and 79 CML patient organisations were evaluable. 32.7% of participants were highly adherent, 46.5% were in the medium and 20.7% in the low adherence group. Factors increasing the probability of being in the high adherence group are older age, male sex, management of side effects, only one tablet per day and feeling well informed about CML by the doctor. More than 2 years since diagnosis were significantly lowering the chance as was the use of reminding tools. Living arrangements, multiple medication and personal payment obligations increased the probability to be at least in the medium adherent group. This is the most comprehensive study conducted to date to gain knowledge about factors causing non-adherence in CML. Better information on the disease, medication and management of side effects, supported by haematologists, is key to improve adherence.

  14. Structural properties of highly conductive ultra-nanocrystalline diamond films grown by hot-filament CVD

    NASA Astrophysics Data System (ADS)

    Mertens, M.; Lin, I.-N.; Manoharan, D.; Moeinian, A.; Brühne, K.; Fecht, H. J.

    2017-01-01

    In this work we show the correlation of the electrical conductivity of ultra-nanocrystalline (UNCD) diamond films grown by hot filament chemical vapor deposition (HFCVD) with their structural properties. The substrate temperature, the methane to hydrogen ratio and the pressure are the main factor influencing the growth of conductive UNCD films, which extends from electrical resistive diamond films (<10-4 S/cm) to highly conductive diamond films with a specific conductivity of 300 S/cm. High-resolution-transmission-electron-microscopy (HRTEM) and electron-energy-loss-spectroscopy (EELS) have been done on the highly conductive diamond films, to show the origin of the high electrical conductivity. The HRTEM results show random oriented diamond grains and a large amount of nano-graphite between the diamond crystals. EELS investigations are confirming these results. Raman measurements are correlated with the specific conductivity, which shows structural changes of sp2 carbons bonds as function of conductivity. Hall experiments complete the results, which lead to a model of an electron mobility based conductivity, which is influenced by the structural properties of the grain boundary regions in the ultra-nanocrystalline diamond films.

  15. Experimental Study on the Electrical Conductivity of Pyroxene Andesite at High Temperature and High Pressure

    NASA Astrophysics Data System (ADS)

    Hui, KeShi; Dai, LiDong; Li, HePing; Hu, HaiYing; Jiang, JianJun; Sun, WenQing; Zhang, Hui

    2016-09-01

    The electrical conductivity of pyroxene andesite was in situ measured under conditions of 1.0-2.0 GPa and 673-1073 K using a YJ-3000t multi-anvil press and Solartron-1260 Impedance/Gain-phase analyzer. Experimental results indicate that the electrical conductivities of pyroxene andesite increase with increasing temperature, and the electrical conductivities decrease with the rise of pressure, and the relationship between electrical conductivity (σ) and temperature (T) conforms to an Arrhenius relation within a given pressure and temperature range. When temperature rises up to 873-923 K, the electrical conductivities of pyroxene andesite abruptly increase, and the activation enthalpy increases at this range, which demonstrates that pyroxene andesite starts to dehydrate. By the virtue of the activation enthalpy (0.35-0.42 eV) and the activation volume (-6.75 ± 1.67 cm3/mole) which characterizes the electrical properties of sample after dehydration, we consider that the conduction mechanism is the small polaron conduction before and after dehydration, and that the rise of carrier concentration is the most important reason of increased electrical conductivity.

  16. Experimental Study on the Electrical Conductivity of Pyroxene Andesite at High Temperature and High Pressure

    NASA Astrophysics Data System (ADS)

    Hui, KeShi; Dai, LiDong; Li, HePing; Hu, HaiYing; Jiang, JianJun; Sun, WenQing; Zhang, Hui

    2017-03-01

    The electrical conductivity of pyroxene andesite was in situ measured under conditions of 1.0-2.0 GPa and 673-1073 K using a YJ-3000t multi-anvil press and Solartron-1260 Impedance/Gain-phase analyzer. Experimental results indicate that the electrical conductivities of pyroxene andesite increase with increasing temperature, and the electrical conductivities decrease with the rise of pressure, and the relationship between electrical conductivity ( σ) and temperature ( T) conforms to an Arrhenius relation within a given pressure and temperature range. When temperature rises up to 873-923 K, the electrical conductivities of pyroxene andesite abruptly increase, and the activation enthalpy increases at this range, which demonstrates that pyroxene andesite starts to dehydrate. By the virtue of the activation enthalpy (0.35-0.42 eV) and the activation volume (-6.75 ± 1.67 cm3/mole) which characterizes the electrical properties of sample after dehydration, we consider that the conduction mechanism is the small polaron conduction before and after dehydration, and that the rise of carrier concentration is the most important reason of increased electrical conductivity.

  17. Combination of benzoyl peroxide 5% gel with liquid cleanser and moisturizer SPF 30 in acne treatment results in high levels of subject satisfaction, good adherence and favorable tolerability.

    PubMed

    Kim, Mi-Ran; Kerrouche, Nabil

    2017-07-05

    Skin care products (cleansers and moisturizers) to complement benzoyl peroxide (BPO) in the treatment of acne may improve treatment tolerability and adherence. Evaluate subject satisfaction after use of BPO 5% gel in combination with liquid cleanser and moisturizer SPF 30. Open-label study including subjects aged ≥12 years with mild-to-moderate facial acne; ClinicalTrials.gov Identifier: NCT02589405. Once daily BPO 5% gel, twice daily liquid cleanser and once daily moisturizer SPF 30 were applied for 12 weeks. Assessments included a subject satisfaction questionnaire, investigator global assessment of improvement, lesion counts, the presence of Propionibacterium acnes, and safety. Fifty subjects were enrolled. Most subjects were overall satisfied with the three-part regimen (87%) and felt better about themselves (94%). Subjects indicated the skin care products helped prepare the skin for treatment (85%), relieve itchy skin (81%) and reduce irritation (87%). Most subjects considered that the liquid cleanser (80%) and moisturizer SPF 30 (84%) were a necessary part of acne treatment. BPO reduced P. acnes load by 89% at week 1. The treatment was well tolerated. The combination of BPO 5% gel with liquid cleanser and moisturizer SPF 30 resulted in high levels of subject satisfaction, good tolerability and treatment adherence.

  18. Production of high-titer human influenza A virus with adherent and suspension MDCK cells cultured in a single-use hollow fiber bioreactor.

    PubMed

    Tapia, Felipe; Vogel, Thomas; Genzel, Yvonne; Behrendt, Ilona; Hirschel, Mark; Gangemi, J David; Reichl, Udo

    2014-02-12

    Hollow fiber bioreactors (HFBRs) have been widely described as capable of supporting the production of highly concentrated monoclonal antibodies and recombinant proteins. Only recently HFBRs have been proposed as new single-use platforms for production of high-titer influenza A virus. These bioreactors contain multiple hollow fiber capillary tubes that separate the bioreactor in an intra- and an extra-capillary space. Cells are usually cultured in the extra-capillary space and can grow to a very high cell concentration. This work describes the evaluation of the single-use hollow fiber bioreactor PRIMER HF (Biovest International Inc., USA) for production of influenza A virus. The process was setup, characterized and optimized by running a total of 15 cultivations. The HFBRs were seeded with either adherent or suspension MDCK cells, and infected with influenza virus A/PR/8/34 (H1N1), and the pandemic strain A/Mexico/4108/2009 (H1N1). High HA titers and TCID₅₀ of up to 3.87 log₁₀(HA units/100 μL) and 1.8 × 10(10)virions/mL, respectively, were obtained for A/PR/8/34 influenza strain. Influenza virus was collected by performing multiple harvests of the extra-capillary space during a virus production time of up to 12 days. Cell-specific virus yields between 2,000 and 8,000 virions/cell were estimated for adherent MDCK cells, and between 11,000 and 19,000 virions/cell for suspension MDCK.SUS2 cells. These results do not only coincide with the cell-specific virus yields obtained with cultivations in stirred tank bioreactors and other high cell density systems, but also demonstrate that HFBRs are promising and competitive single-use platforms that can be considered for commercial production of influenza virus. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Highly electrically conductive nanocomposites based on polymer-infused graphene sponges.

    PubMed

    Li, Yuanqing; Samad, Yarjan Abdul; Polychronopoulou, Kyriaki; Alhassan, Saeed M; Liao, Kin

    2014-04-11

    Conductive polymer composites require a three-dimensional 3D network to impart electrical conductivity. A general method that is applicable to most polymers for achieving a desirable graphene 3D network is still a challenge. We have developed a facile technique to fabricate highly electrical conductive composite using vacuum-assisted infusion of epoxy into graphene sponge GS scaffold. Macroscopic GSs were synthesized from graphene oxide solution by a hydrothermal method combined with freeze drying. The GS/epoxy composites prepared display consistent isotropic electrical conductivity around 1 S/m, and it is found to be close to that of the pristine GS. Compared with neat epoxy, GS/epoxy has a 12-orders-of-magnitude increase in electrical conductivity, attributed to the compactly interconnected graphene network constructed in the polymer matrix. This method can be extended to other materials to fabricate highly conductive composites for practical applications such as electronic devices, sensors, actuators, and electromagnetic shielding.

  20. Microstructural modeling of thermal conductivity of high burn-up mixed oxide fuel

    NASA Astrophysics Data System (ADS)

    Teague, Melissa; Tonks, Michael; Novascone, Stephen; Hayes, Steven

    2014-01-01

    Predicting the thermal conductivity of oxide fuels as a function of burn-up and temperature is fundamental to the efficient and safe operation of nuclear reactors. However, modeling the thermal conductivity of fuel is greatly complicated by the radially inhomogeneous nature of irradiated fuel in both composition and microstructure. In this work, radially and temperature-dependent models for effective thermal conductivity were developed utilizing optical micrographs of high burn-up mixed oxide fuel. The micrographs were employed to create finite element meshes with the OOF2 software. The meshes were then used to calculate the effective thermal conductivity of the microstructures using the BISON [1] fuel performance code. The new thermal conductivity models were used to calculate thermal profiles at end of life for the fuel pellets. These results were compared to thermal conductivity models from the literature, and comparison between the new finite element-based thermal conductivity model and the Duriez-Lucuta model was favorable.

  1. Microstructural Modeling of Thermal Conductivity of High Burn-up Mixed Oxide Fuel

    SciTech Connect

    Melissa Teague; Michael Tonks; Stephen Novascone; Steven Hayes

    2014-01-01

    Predicting the thermal conductivity of oxide fuels as a function of burn-up and temperature is fundamental to the efficient and safe operation of nuclear reactors. However, modeling the thermal conductivity of fuel is greatly complicated by the radially inhomogeneous nature of irradiated fuel in both composition and microstructure. In this work, radially and temperature-dependent models for effective thermal conductivity were developed utilizing optical micrographs of high burn-up mixed oxide fuel. The micrographs were employed to create finite element meshes with the OOF2 software. The meshes were then used to calculate the effective thermal conductivity of the microstructures using the BISON fuel performance code. The new thermal conductivity models were used to calculate thermal profiles at end of life for the fuel pellets. These results were compared to thermal conductivity models from the literature, and comparison between the new finite element-based thermal conductivity model and the Duriez–Lucuta model was favorable.

  2. How payment scheme affects patients’ adherence to medications? A systematic review

    PubMed Central

    Aziz, Hamiza; Hatah, Ernieda; Makmor Bakry, Mohd; Islahudin, Farida

    2016-01-01

    Background A previous systematic review reported that increase in patients’ medication cost-sharing reduced patients’ adherence to medication. However, a study among patients with medication subsidies who received medication at no cost found that medication nonadherence was also high. To our knowledge, no study has evaluated the influence of different medication payment schemes on patients’ medication adherence. Objective This study aims to review research reporting the influence of payment schemes and their association with patients’ medication adherence behavior. Methods This study was conducted using systematic review of published articles. Relevant published articles were located through three electronic databases Medline, ProQuest Medical Library, and ScienceDirect since inception to February 2015. Included articles were then reviewed and summarized narratively. Results Of the total of 2,683 articles located, 21 were included in the final analysis. There were four types of medication payment schemes reported in the included studies: 1) out-of-pocket expenditure or copayments; 2) drug coverage or insurance benefit; 3) prescription cap; and 4) medication subsidies. Our review found that patients with “lower self-paying constraint” were more likely to adhere to their medication (adherence rate ranged between 28.5% and 94.3%). Surprisingly, the adherence rate among patients who received medication as fully subsidized was similar (rate between 34% and 84.6%) as that of other payment schemes. The studies that evaluated patients with fully subsidized payment scheme found that the medication adherence was poor among patients with nonsevere illness. Conclusion Although medication adherence was improved with the reduction of cost-sharing such as lower copayment, higher drug coverage, and prescription cap, patients with full-medication subsidies payment scheme (received medication at no cost) were also found to have poor adherence to their medication. Future

  3. Nurse interventions to improve medication adherence among discharged older adults: a systematic review.

    PubMed

    Verloo, Henk; Chiolero, Arnaud; Kiszio, Blanche; Kampel, Thomas; Santschi, Valérie

    2017-09-01

    discharged older adult inpatients are often prescribed numerous medications. However, they only take about half of their medications and many stop treatments entirely. Nurse interventions could improve medication adherence among this population. to conduct a systematic review of trials that assessed the effects of nursing interventions to improve medication adherence among discharged, home-dwelling and older adults. we conducted a systematic review according to the methods in the Cochrane Collaboration Handbook and reported results according to the PRISMA statement. We searched for controlled clinical trials (CCTs) and randomised CCTs (RCTs), published up to 8 November 2016 (using electronic databases, grey literature and hand searching), that evaluated the effects of nurse interventions conducted alone or in collaboration with other health professionals to improve medication adherence among discharged older adults. Medication adherence was defined as the extent to which a patient takes medication as prescribed. out of 1,546 records identified, 82 full-text papers were evaluated and 14 studies were included-11 RCTs and 2 CCTs. Overall, 2,028 patients were included (995 in intervention groups; 1,033 in usual-care groups). Interventions were nurse-led in seven studies and nurse-collaborative in seven more. In nine studies, adherence was higher in the intervention group than in the usual-care group, with the difference reaching statistical significance in eight studies. There was no substantial difference in increased medication adherence whether interventions were nurse-led or nurse-collaborative. Four of the 14 studies were of relatively high quality. nurse-led and nurse-collaborative interventions moderately improved adherence among discharged older adults. There is a need for large, well-designed studies using highly reliable tools for measuring medication adherence.

  4. A Novel Method for Measuring Electrical Conductivity of High Insulating Oil Using Charge Decay

    NASA Astrophysics Data System (ADS)

    Wang, Z. Q.; Qi, P.; Wang, D. S.; Wang, Y. D.; Zhou, W.

    2016-05-01

    For the high insulating oil, it is difficult to measure the conductivity precisely using voltammetry method. A high-precision measurementis proposed for measuring bulk electrical conductivity of high insulating oils (about 10-9--10-15S/m) using charge decay. The oil is insulated and charged firstly, and then grounded fully. During the experimental procedure, charge decay is observed to show an exponential law according to "Ohm" theory. The data of time dependence of charge density is automatically recorded using an ADAS and a computer. Relaxation time constant is fitted from the data using Gnuplot software. The electrical conductivity is calculated using relaxation time constant and dielectric permittivity. Charge density is substituted by electric potential, considering charge density is difficult to measure. The conductivity of five kinds of oils is measured. Using this method, the conductivity of diesel oil is easily measured to beas low as 0.961 pS/m, as shown in Fig. 5.

  5. Layered conductive polymer on nylon membrane templates for high performance, thin-film supercapacitor electrodes

    NASA Astrophysics Data System (ADS)

    Shi, HaoTian Harvey; Naguib, Hani E.

    2016-04-01

    Flexible Thin-film Electrochemical Capacitors (ECs) are emerging technology that plays an important role as energy supply for various electronics system for both present era and the future. Intrinsically conductive polymers (ICPs) are promising pseudo-capacitive materials as they feature both good electrical conductivity and high specific capacitance. This study focuses on the construction and characterization of ultra-high surface area porous electrodes based on coating of nano-sized conductive polymer materials on nylon membrane templates. Herein, a novel nano-engineered electrode material based on nylon membranes was presented, which allows the creation of super-capacitor devices that is capable of delivering competitive performance, while maintaining desirable mechanical characteristics. With the formation of a highly conductive network with the polyaniline nano-layer, the electrical conductivity was also increased dramatically to facilitate the charge transfer process. Cyclic voltammetry and specific capacitance results showed promising application of this type of composite materials for future smart textile applications.

  6. High relapse rate and poor medication adherence in the Chinese population with schizophrenia: results from an observational survey in the People’s Republic of China

    PubMed Central

    Xiao, Jingbo; Mi, Weifeng; Li, Lingzhi; Shi, Ying; Zhang, Hongyan

    2015-01-01

    Background Relapse is common in schizophrenia, and seriously impacts patients’ quality of life and social functioning. Many factors have been identified that may potentially increase the risk of relapse. This study was designed to investigate the relapse rate in the year following hospital discharge among Chinese patients with schizophrenia in the naturalistic condition, and to explore possible risk factors related to relapse. Methods We conducted a large, multicenter, retrospective, observational study in ten psychiatric hospitals throughout the People’s Republic of China. Nine hundred and ninety-two schizophrenic outpatients aged 18–65 years discharged from these hospitals between September 2011 and February 2012 with recovery/improvement of their condition were included in the study. Information about relapse and correlative factors during the year after discharge was collected by telephone interview using a questionnaire. Results Eight hundred and seventy-six of 992 eligible patients completed the telephone survey. Of these patients, 293 (33.4%) had at least one relapse within 1 year after discharge, and 165 (18.8%) were rehospitalized. In respondents’ view, the most important factor contributing to relapse was poor medication adherence (50.7%). Approximately 30% of the respondents had a negative attitude toward medication, with the impression that there was no need to take drugs at all or for a long time. Nonadherent patients (37.9%) had a relapse rate that was 2.5-fold higher than adherent patients (54.5% versus 20.7%, P<0.001). The top five risk factors associated with relapse were nonadherence to medication (odds ratio [OR] 4.602, 95% confidence interval [CI] 3.410–6.211), being without work (OR 3.275, 95% CI 2.291–4.681), poor self-care ability (OR 2.996, 95% CI 2.129–4.214), poor interpersonal skills (OR 2.635, 95% CI 1.951–3.558), and hospitalization on more than three occasions (OR 2.299, 95% CI 1.691–3.126). Conclusion The 1-year

  7. Adherence: a concept analysis.

    PubMed

    Gardner, Carrie Lee

    2015-04-01

    To utilize a Wilsonian method of concept analysis to define and describe the concept of adherence. Published research articles, nursing literature, published books, and national and international advisory reports. The concept of adherence was analyzed using the Wilson method. Results, applications, and practice implications in regards to the concept of adherence were then derived from the analysis. Adherence is a complex, multifaceted concept that can greatly impact patient behaviors and nursing practice. Further clarification of adherence is needed to help delineate this concept from other related terms. Healthcare providers should have an understanding of the concept of adherence in the context of patient care in order to guide patient self-care behaviors. © 2014 NANDA International, Inc.

  8. Adolescents in southern regions of Italy adhere to the Mediterranean diet more than those in the northern regions.

    PubMed

    Noale, Marianna; Nardi, Mariateresa; Limongi, Federica; Siviero, Paola; Caregaro, Lorenza; Crepaldi, Gaetano; Maggi, Stefania

    2014-09-01

    There is a large amount of literature regarding the benefits of the Mediterranean diet in the adult population; however, there is growing curiosity about the individuals who naturally adhere to those principles early in life. The "Evaluation of Dietary Habits in Adolescents," carried out by the National Research Council of Italy in 2009, is a survey that aimed to assess the dietary habits and lifestyles of Italian adolescents and their adherence to the Mediterranean diet. We hypothesized that there would be differences across regions, with a higher adherence in Southern Italy compared with Northern Italy based on geography. The survey was conducted in 3 different geographic locations in Italy and included a convenience sample of adolescents who attended either a middle or high school. The participants were asked to fill out a questionnaire concerning demographic data, lifestyle factors, and eating patterns, and scores were assigned according to adherence to the Mediterranean diet, as calculated using Trichopoulou's Mediterranean diet scale. The final sample included 565 adolescents, between 12 and 19 years old, who attended school in the northeastern, northwestern, or southern regions of Italy in 2009. According to the findings, 38.6% of the respondents had scores indicating a low adherence to the Mediterranean diet, whereas only 14% had scores showing a high adherence. Teenagers from the Southern region showed the highest adherence. Those with a high adherence to the Mediterranean diet consumed higher quantities of fiber, iron, vitamin B6, vitamin C, folic acid, vitamin A, vitamin D, and monounsaturated fats.

  9. Highly conductive and stretchable polymer composites based on graphene/MWCNT network.

    PubMed

    Chen, Mengting; Tao, Tao; Zhang, Ling; Gao, Wei; Li, Chunzhong

    2013-02-25

    We have manufactured a highly conductive and stretchable composite by backfilling a preformed graphene/MWCNT aerogel with poly(dimethylsiloxane) (PDMS). The electrical conductivity of our product can reach 2.8 S cm(-1) with only 1.3 wt% graphene/MWCNT loading, and remains constant after 100 times repeated stretching by 20% and 5000 times bending.

  10. Carbon-nanotube/silver networks in nitrile butadiene rubber for highly conductive flexible adhesives.

    PubMed

    Ma, Rujun; Kwon, Seoyoung; Zheng, Qing; Kwon, Hyeok Yong; Kim, Jae Il; Choi, Hyouk Ryeol; Baik, Seunghyun

    2012-07-03

    An adhesive with high conductivity, flexibility, cyclability, oxidation resistance, and good adhesion is developed using microscale silver flakes, multiwalled carbon nanotubes decorated with nanoscale silver particles, and nitrile butadiene rubber. Light-emitting-diode chips are attached to the conductive, flexible adhesive pattern on a poly(ethylene terephthalate) substrate as a visual demonstration. The brightness is invariant during bending tests.

  11. Middle-Ear Function At High Frequencies Quantified With Advanced Bone Conduction Measures

    PubMed Central

    Popelka, Gerald R.; Telukuntla, Goutham; Puria, Sunil

    2009-01-01

    Auditory thresholds with standardized clinical procedures are obtained over a much narrower frequency range by bone conduction than by air conduction. As a result, diagnostic information for both sensorineural and conductive-mechanism function is incomplete for high frequencies. A new magnetostrictive bone-conduction transducer that has the potential for improved output in the high-frequency range was evaluated in the laboratory and in a variety of subjects with normal hearing (N=11) or sensorineural hearing loss (N=9). Laboratory results indicated that harmonic distortion and acoustic radiation were both sufficiently low to allow accurate threshold measurements. Auditory thresholds obtained with this magnetostrictive bone-conduction transducer can be measured accurately under conventional clinical conditions for frequencies up to 16 kHz and levels up to 85 dB HL. These measures can be used to accurately characterize sensorineural hearing sensitivity for high frequencies and, when combined with standard air-conduction measures for high frequencies, to accurately characterize conductive-mechanism function for frequencies higher than possible with current diagnostic bone-conduction technology. PMID:19900526

  12. A promising structure for fabricating high strength and high electrical conductivity copper alloys

    PubMed Central

    Li, Rengeng; Kang, Huijun; Chen, Zongning; Fan, Guohua; Zou, Cunlei; Wang, Wei; Zhang, Shaojian; Lu, Yiping; Jie, Jinchuan; Cao, Zhiqiang; Li, Tingju; Wang, Tongmin

    2016-01-01

    To address the trade-off between strength and electrical conductivity, we propose a strategy: introducing precipitated particles into a structure composed of deformation twins. A Cu-0.3%Zr alloy was designed to verify our strategy. Zirconium was dissolved into a copper matrix by solution treatment prior to cryorolling and precipitated in the form of Cu5Zr from copper matrix via a subsequent aging treatment. The microstructure evolutions of the processed samples were investigated by transmission electron microscopy and X-ray diffraction analysis, and the mechanical and physical behaviours were evaluated through tensile and electrical conductivity tests. The results demonstrated that superior tensile strength (602.04 MPa) and electrical conductivity (81.4% IACS) was achieved. This strategy provides a new route for balancing the strength and electrical conductivity of copper alloys, which can be developed for large-scale industrial application. PMID:26856764

  13. A promising structure for fabricating high strength and high electrical conductivity copper alloys.

    PubMed

    Li, Rengeng; Kang, Huijun; Chen, Zongning; Fan, Guohua; Zou, Cunlei; Wang, Wei; Zhang, Shaojian; Lu, Yiping; Jie, Jinchuan; Cao, Zhiqiang; Li, Tingju; Wang, Tongmin

    2016-02-09

    To address the trade-off between strength and electrical conductivity, we propose a strategy: introducing precipitated particles into a structure composed of deformation twins. A Cu-0.3%Zr alloy was designed to verify our strategy. Zirconium was dissolved into a copper matrix by solution treatment prior to cryorolling and precipitated in the form of Cu5Zr from copper matrix via a subsequent aging treatment. The microstructure evolutions of the processed samples were investigated by transmission electron microscopy and X-ray diffraction analysis, and the mechanical and physical behaviours were evaluated through tensile and electrical conductivity tests. The results demonstrated that superior tensile strength (602.04 MPa) and electrical conductivity (81.4% IACS) was achieved. This strategy provides a new route for balancing the strength and electrical conductivity of copper alloys, which can be developed for large-scale industrial application.

  14. High temperature liquid metal corrosion and high temperature electrical conductivity of Y 2O 3

    NASA Astrophysics Data System (ADS)

    Yoneoka, Toshiaki; Terai, Takayuki; Takahashi, Yoichi

    1997-09-01

    Yttrium sesquioxide has been proposed as a promising candidate material for collector electrodes used in the laser enrichment system of uranium-235. For this purpose, yttria is expected to be compatible with molten uranium and electrically conductive. A corrosion test of yttria with molten lanthanum as a simulating metal for uranium and a measurement of its electrical conductivity under extremely low oxygen pressure were performed. It was shown from the corrosion test that a yttria sample was considerably corroded by the molten lanthanum at 1513 K and the maximum corrosion depth for 5 Ms was 0.162 mm. The electrical conductivity of hypo-stoichiometric yttria reduced by titanium was higher than that of pure germanium at room temperature (2.1 S/m). The oxygen pressures equilibrated with the yttria specimens were estimated to discuss the relation to measured conductivities.

  15. Medication Adherence Interventions That Target Subjects with Adherence Problems: Systematic Review and Meta-analysis

    PubMed Central

    Conn, Vicki S.; Ruppar, Todd M.; Enriquez, Maithe; Cooper, Pam

    2015-01-01

    Background Inadequate medication adherence is a pervasive, under-recognized cause of poor health outcomes. Many intervention trials designed to improve medication adherence have targeted adults with adherence problems. No previous reviews have synthesized the effectiveness of medication adherence interventions focused on subjects with medication adherence difficulties. Objective This systematic review and meta-analysis synthesized findings from medication adherence intervention studies conducted among adults with medication adherence difficulties. Methods Primary research studies were eligible for inclusion if they tested an intervention designed to increase medication adherence among adults with documented adherence difficulties and reported medication adherence behavior outcomes. Comprehensive search strategies of 13 computerized databases, author and ancestry searches, and hand searches of 57 journals were used to locate eligible primary research. Participant demographics, intervention characteristics, and methodological features were reliably coded from reports along with medication adherence outcomes. Effect sizes for outcomes were calculated as standardized mean differences, and random effects models were used to estimate overall mean effects. Exploratory dichotomous and continuous variable moderator analyses were employed to examine potential associations between medication adherence effect size and sample, intervention, and methodological characteristics. Results Data were extracted from 53 reports of studies involving 8,243 individual primary study participants. The overall standardized mean difference effect size for treatment vs. control subjects was 0.301. For treatment pre- vs. post-intervention comparisons, the overall effect size was 0.533. Significantly larger effect sizes were associated with interventions incorporating prompts to take medications than interventions lacking medication prompts (0.497 vs. 0.234). Larger effect sizes were also found

  16. Arginine-glycine-aspartic acid- and fibrinogen gamma-chain carboxyterminal peptides inhibit platelet adherence to arterial subendothelium at high wall shear rates. An effect dissociable from interference with adhesive protein binding.

    PubMed Central

    Lawrence, J B; Kramer, W S; McKeown, L P; Williams, S B; Gralnick, H R

    1990-01-01

    Arg-Gly-Asp (RGD)- and fibrinogen gamma-chain carboxyterminal (GQQHHLGGAKQAGDV) peptides inhibit fibrinogen, fibronectin (Fn), vitronectin, and von Willebrand factor (vWF) binding to the platelet glycoprotein IIb-IIIa complex (GP IIb-IIIa). GP IIb-IIIa, vWF, and Fn are essential for normal platelet adherence to subendothelium. We added peptides to normal citrated whole blood before perfusion over human umbilical artery subendothelium and evaluated platelet adherence morphometrically at high (2,600 s-1) and low (800 s-1) wall shear rates. We also examined the effects of the peptides on platelet adhesion to collagen in a static system. At the high wall shear rate, RGDS and GQQHHLGGAKQAGDV caused dose-dependent reduction in the surface coverage with spread and adherent platelets. Amino acid transposition and conservative substitutions of RGD peptides and the AGDV peptide significantly inhibited platelet adherence at 2,600 s-1. By contrast, the modified RGD peptides and AGDV do not affect adhesive protein binding to platelets. None of the native or modified RGD- or fibrinogen gamma-chain peptides significantly inhibited either platelet adherence to subendothelium at 800 s-1 or platelet adhesion to collagen. Our findings demonstrate that peptides that interfere with adhesive protein binding to GP IIb-IIIa inhibit platelet adherence to vascular subendothelium with flowing blood only at high wall shear rates. Platelet adherence to subendothelium at high wall shear rates appears to be mediated by different recognition specificities from those required for fluid-phase adhesive protein binding or static platelet adhesion. PMID:2243140

  17. [The importance of adherence to oral therapies in the field of oncology: the example of breast cancer].

    PubMed

    Huiart, Laetitia; Bardou, Valérie-Jeanne; Giorgi, Roch

    2013-10-01

    Today, over 40 different oral anticancer therapies are available in the French prescription pricing authority dictionary. Adherence to these therapies has become a major issue in the field of oncology. Most of the available research has focused on adherence to hormonal therapy for breast cancer (BC). The objective of this paper is to synthesize current knowledge on adherence and persistence to hormonal therapy for BC. Available studies display significant heterogeneity due to variability in the measurements and data sources used, as well as in the timing of the measurements. Adherence and persistence estimates have recently been summarized in a meta-regression analysis. For tamoxifen, adherence ranges from 79% at one year to 65% at five years, and for Aromatase Inhibitors (AI), from 80% at one year to 72% at five years. Persistence decreases with the increasing duration of treatment: from a high of 86% of patients persistent at 1 year to a low of 53% at five years for tamoxifen, and from 88% to 69% for AI. Some of the modifiable determinants of adherence are directly linked to the patient-physician relation, to information provided during consultations, or to the specialty of the physician involved in the patient follow-up. Non-modifiable determinants, such as age or comorbidities, can be used to identify sub-groups of patients at high risk of non-adherence in order to target interventions. Few trials have been conducted in oncology to evaluate the efficacy of interventions to improve adherence. Adherence directly impacts both the efficacy of treatment and long-term treatment costs. Interventions to improve adherence to oral therapies should be systematically promoted in oncology. Improving adherence should be considered a priority in the field, lest physicians continue writing inefficient prescriptions for highly efficacious treatments.

  18. Rubbery solid electrolytes with dominant cationic transport and high ambient conductivity

    NASA Astrophysics Data System (ADS)

    Angell, C. A.; Liu, C.; Sanchez, E.

    1993-03-01

    EFFORTS to develop a high-voltage, lightweight rechargeable battery for electrically powered vehicles have focused on batteries based on solid electrolytes, which offer good mechanical strength, easy packaging and high energy densities. An important objective is to identify an electrolyte with the desired combination of mechanical properties, electrical conductivity and stability against powerfully oxidizing and reducing electrodes (lithium is preferred for the anode). Among the most promising materials are rubbery 'salt-in-polymer' electrolytes and highly conducting but brittle superionic glass electrolytes. In the latter category are salts with good lithium-ion conductivity, which are compatible with lithium-anode systems. Here we describe new ionic conductors - 'polymer-in-salt' materials - in which lithium salts are mixed with small quantities of the polymers polypropylene oxide and polyethylene oxide. These materials have glass transitions low enough to remain rubbery at room temperature while preserving good lithium-ion conductivities and high electrochemical stability.

  19. Thermopower and High Pressure Electrical Conductivity Measurements of Template Synthesized Polypyrrole.

    DTIC Science & Technology

    1996-01-01

    We present results of high pressure - low temperature studies of template synthesized polypyrrole . Thermopower measurements at ambient pressure show...conductivity, especially at very low temperatures. The comparison with bulk samples of polypyrrole suggests that the template synthesis increases the

  20. Surprisingly High Conductivity and Efficient Exciton Blocking in Fullerene/Wide-Energy-Gap Small Molecule Mixtures.

    PubMed

    Bergemann, Kevin J; Amonoo, Jojo A; Song, Byeongseop; Green, Peter F; Forrest, Stephen R

    2015-06-10

    We find that mixtures of C60 with the wide energy gap, small molecular weight semiconductor bathophenanthroline (BPhen) exhibit a combination of surprisingly high electron conductivity and efficient exciton blocking when employed as buffer layers in organic photovoltaic cells. Photoluminescence quenching measurements show that a 1:1 BPhen/C60 mixed layer has an exciton blocking efficiency of 84 ± 5% compared to that of 100% for a neat BPhen layer. This high blocking efficiency is accompanied by a 100-fold increase in electron conductivity compared with neat BPhen. Transient photocurrent measurements show that charge transport through a neat BPhen buffer is dispersive, in contrast to nondispersive transport in the compound buffer. Interestingly, although the conductivity is high, there is no clearly defined insulating-to-conducting phase transition with increased insulating BPhen fraction. Thus, we infer that C60 undergoes nanoscale (<10 nm domain size) phase segregation even at very high (>80%) BPhen fractions.

  1. High Conductivity Water Treatment Using Water Surface Discharge with Nonmetallic Electrodes

    NASA Astrophysics Data System (ADS)

    Wang, Xiaoping; Zhang, Xingwang; Lei, Lecheng

    2013-06-01

    Although electrohydraulic discharge is effective for wastewater treatment, its application is restricted by water conductivity and limited to the treatment of low conductivity water. For high conductivity water treatment, water-surface discharge is the preferred choice. However, the metallic electrodes are easily corroded because of the high temperature and strong oxidative environment caused by gas phase discharge and the electrochemical reaction in water. As a result, the efficiency of the water treatment might be affected and the service life of the reactor might be shortened. In order to avoid the corrosion problem, nonmetallic electrode water-surface discharge is introduced into high conductivity water treatment in the present study. Carbon-felt and water were used as the high voltage electrode and ground electrode, respectively. A comparison of the electrical and chemical characteristics showed that nonmetallic electrode discharge maintained the discharge characteristics and enhanced the energy efficiency, and furthermore, the corrosion of metal electrodes was avoided.

  2. Level of adherence to the Mediterranean diet among children from Cyprus: the CYKIDS study.

    PubMed

    Lazarou, Chrystalleni; Panagiotakos, Demosthenes B; Matalas, Antonia-Leda

    2009-07-01

    The Mediterranean diet (MD) prototype is widely used as an educational tool in public health programmes; few studies, however, have been conducted on the adherence of children to this diet. To evaluate the quality of Cypriot children's diet by assessing the degree of adherence to the MD. A national cross-sectional study among 1140 children (mean age = 10.7 (SD 0.98) years), using stratified multistage sampling design, was conducted in primary schools of Cyprus. Dietary assessment was based on a 154-item semi-quantitative FFQ and the two supplementary questionnaires (a Food Groups Frequency Questionnaire and a Short Eating Habits Questionnaire). Adherence to the MD was assessed by the KIDMED index. The association between the frequencies of consumption of various food groups and the level of adherence to the MD (poor v. average v. good KIDMED score) was also evaluated. Multiple logistic regression analyses were used to adjust for potential confounders. Only 6.7% of the sample was classified as high adherers of MD, whereas 37% had a poor KIDMED score. Multiple logistic regression analysis has shown that children with at least an average KIDMED score were more likely to eat frequently seafood and fish, legumes, nuts, bread, fruits, leafy vegetables, olives, low glycaemic index foods and unrefined foods. Effect size of associations was from medium to high. Higher adherence to MD is associated with better diet quality in children. The MD prototype may thus represent a useful educational tool for promotion of healthy eating habits in children.

  3. Densely adherent growth mode, rather than extracellular polymer substance matrix build-up ability, contributes to high resistance of Staphylococcus epidermidis biofilms to antibiotics.

    PubMed

    Qu, Yue; Daley, Andrew J; Istivan, Taghrid S; Rouch, Duncan A; Deighton, Margaret A

    2010-07-01

    (i) To evaluate the role of the adherent growth mode and extracellular polymer substance build-up in biofilm resistance to antibiotics. (ii) To re-assess various mechanisms leading to biofilm resistance to antibiotics. We compared the biofilm MICs, biofilm MBCs using the viable count method, biofilm MBCs based on broth recovery methods and minimum biofilm eradication concentrations (MBECs) of antistaphylococcal antibiotics for multilayer biofilms formed by 'biofilm-positive' S. epidermidis strains and monolayer biofilms formed by their 'biofilm-negative' mutants/variants. Bacterial densities and the quantity of persister cells in both multilayer and monolayer biofilms were assessed to evaluate their roles in biofilm resistance. Monolayer and multilayer biofilms presented similar susceptibilities to multiple antibiotics, based on biofilm MIC, broth recovery-based biofilm MBC and MBEC results. Multilayer biofilms demonstrated higher viable count-based MBCs than monolayer biofilms. Both monolayer and multilayer biofilms had very high bacterial densities of approximately 10(11-12) cfu/mL. Persister cells were found in both monolayer and multilayer biofilms, but not in planktonic cultures at log phase. The presence of persister cells in monolayer and multilayer biofilms appeared to be strain and antibiotic dependent. The adherent growth mode, rather than the ability to build up a typical multilayer biofilm structure, contributes to the high resistance of biofilms to antibiotics, and therefore might be the main virulence factor of coagulase-negative staphylococci (CoNS) with respect to antibiotic resistance. The presence of persister cells in CoNS biofilms plays an important role in antibiotic resistance. Growth at high bacterial densities is another significant factor in biofilm resistance.

  4. Enhanced charge transport in highly conducting PEDOT-PSS films after acid treatment

    NASA Astrophysics Data System (ADS)

    Shiva, V. Akshaya; Bhatia, Ravi; Menon, Reghu

    The high electrical conductivity, good stability, high strength, flexibility and good transparency of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT-PSS), make it useful for many applications including polymeric anodes for organic photovoltaics, light-emitting diodes, flexible electrodes, supercapacitors, electrochromic devices, field-effect transistors and antistatic-coatings. However, the electrical conductivity of PEDOT-PSS has to be increased significantly for replacement of indium tin oxide (ITO) as the transparent electrode in optoelectronic devices. The as prepared (pristine) PEDOT-PSS film prepared from the PEDOT-PSS aqueous solution usually has conductivity below 1Scm-1, remarkably lower than ITO. Significant conductivity enhancement has been observed on transparent and conductive PEDOT-PSS films after a treatment with inorganic acids. Our study investigates the charge transport in pristine and H2SO4, HNO3, HCl treated PEDOT-PSS films. We have treated the films with various concentrations of acids to probe the effect of the acid treatment on the conduction mechanism. The study includes the measurement of dc and electric field dependent conductivity of films in the temperature range of 4.2K-300K. We have also performed magneto-resistance measurements in the range of 0-5T. An enhancement by a factor of~103 has been observed in the room temperature conductivity. The detailed magneto-transport studies explain the various mechanisms for the conductivity enhancement observed.

  5. Challenges in using mobile phones for collection of antiretroviral therapy adherence data in a resource-limited setting.

    PubMed

    Haberer, Jessica E; Kiwanuka, Julius; Nansera, Denis; Wilson, Ira B; Bangsberg, David R

    2010-12-01

    Frequent antiretroviral therapy adherence monitoring could detect incomplete adherence before viral rebound develops and thus potentially prevent treatment failure. Mobile phone technologies make frequent, brief adherence interviews possible in resource-limited settings; however, feasibility and acceptability are unknown. Interactive voice response (IVR) and short message service (SMS) text messaging were used to collect adherence data from 19 caregivers of HIV-infected children in Uganda. IVR calls or SMS quantifying missed doses were sent in the local language once weekly for 3-4 weeks. Qualitative interviews were conducted to assess participant impressions of the technologies. Participant interest and participation rates were high; however, weekly completion rates for adherence queries were low (0-33%), most commonly due to misunderstanding of personal identification numbers. Despite near ubiquity of mobile phone technology in resource-limited settings, individual level collection of healthcare data presents challenges. Further research is needed for effective training and incentive methods.

  6. NanoCapillary Network Proton Conducting Membranes for High Temperature Hydrogen/Air Fuel Cells

    SciTech Connect

    Pintauro, Peter

    2012-07-09

    The objective of this proposal is to fabricate and characterize a new class of NanoCapillary Network (NCN) proton conducting membranes for hydrogen/air fuel cells that operate under high temperature, low humidity conditions. The membranes will be intelligently designed, where a high density interconnecting 3-D network of nm-diameter electrospun proton conducting polymer fibers is embedded in an inert (uncharged) water/gas impermeable polymer matrix. The high density of fibers in the resulting mat and the high ion-exchange capacity of the fiber polymer will ensure high proton conductivity. To further enhance water retention, molecular silica will be added to the sulfonated polymer fibers. The uncharged matrix material will control water swelling of the high ion-exchange capacity proton conducting polymer fibers and will impart toughness to the final nanocapillary composite membrane. Thus, unlike other fuel cell membranes, the role of the polymer support matrix will be decoupled from that of the proton-conducting channels. The expected final outcome of this 5-year project is the fabrication of fuel cell membranes with properties that exceed the DOE’s technical targets, in particular a proton conductivity of 0.1 S/cm at a temperature less than or equal to120°C and 25-50% relative humidity.

  7. Refining a Personalized mHealth Intervention to Promote Medication Adherence among HIV+ Methamphetamine Users

    PubMed Central

    Montoya, Jessica L.; Georges, Shereen; Poquette, Amelia; Depp, Colin A.; Atkinson, J. Hampton; Moore, David J.

    2014-01-01

    Mobile health (mHealth) interventions to promote antiretroviral therapy (ART) adherence have shown promise; however, among persons living with HIV who abuse methamphetamine (MA) effective tailoring of content to match the expressed needs of this patient population may be necessary. This study aimed: 1) to understand patient perspectives of barriers and facilitators of ART adherence among people with HIV who use MA, and 2) to obtain feedback on the thematic content of an mHealth intervention in order to tailor the intervention to this subgroup. Two separate focus groups, each with ten HIV+/MA+ individuals, were conducted. Transcribed audio recordings were qualitatively analyzed to identify emergent themes. Interrater reliability of themes was high (mean Kappa=.97). Adherence barriers included MA use, misguided beliefs about ART adherence, memory and planning difficulties, social barriers and perceived stigma, and mental heath issues. Facilitators of effective ART adherence were cognitive compensatory strategies, promotion of well being, health care supports, adherence education, and social support. Additionally, the focus groups generated content for reminder text messages to be used in the medication adherence intervention. This qualitative study demonstrates feasibility of using focus groups to derive patient-centered intervention content to address the health challenge at hand in targeted populations. Clinical Trial # NCT01317277 PMID:24911433

  8. Gender Difference in Cancer Patients' Adherence to Analgesics and Related Outcomes of Pain Management.

    PubMed

    Chou, Pi-Ling; Fang, Su-Ying; Sun, Jia-Ling; Rau, Kun-Ming; Lee, Bih-O

    2017-07-27

    Males and females have significant differences in certain medical outcomes. However, little research has explored the gender differences in cancer patient perceptions of analgesics, the relationship between gender and analgesic adherence, or the effectiveness of pain management. The objectives of this study were to compare gender differences associated with hesitancy to use analgesics, analgesic adherence, or pain management effectiveness and to examine whether gender can precisely predict analgesic adherence. The study was conducted in the outpatient oncology department of a medical center in Taiwan. A descriptive and cross-sectional design was used. The study samples were collected from 362 cancer patients. The participants completed the short version of the Barriers Questionnaire-Taiwan, the Morisky Analgesics Adherence Measure-Taiwan version, the Brief Pain Inventory-Chinese version, the Pain Management Index, and a demographic and disease questionnaire. The pain intensity and hesitancy to use analgesics scores were significantly higher among females than among males. The Pain Management Index results indicated that a larger percentage of males had adequate pain management. In addition, being male was a significant predictor of higher analgesic adherence (odds ratio, 1.93; P < .05). Gender could precisely predict cancer patients' medication adherence. Women experienced significantly greater pain than did men but also had more hesitancy to use analgesics, lower adherence, and inadequate pain management. Healthcare professionals should consider women as a high-risk group for inadequate pain control. It is crucial for health providers to consider the gender discrepancy when attempting to improve cancer pain management.

  9. Nanostructured Cu-Cr alloy with high strength and electrical conductivity

    SciTech Connect

    Islamgaliev, R. K. Nesterov, K. M.; Bourgon, J.; Champion, Y.; Valiev, R. Z.

    2014-05-21

    The influence of nanostructuring by high pressure torsion (HPT) on strength and electrical conductivity in the Cu-Cr alloy has been investigated. Microstructure of HPT samples was studied by transmission electron microscopy with special attention on precipitation of small chromium particles after various treatments. Effect of dynamic precipitation leading to enhancement of strength and electrical conductivity was observed. It is shown that nanostructuring leads to combination of high ultimate tensile strength of 790–840 MPa, enhanced electrical conductivity of 81%–85% IACS and thermal stability up to 500 °C. The contributions of grain refinement and precipitation to enhanced properties of nanostructured alloy are discussed.

  10. In Situ Polymerization and Characterization of Highly Conducting Polypyrrole Fish Scales for High-Frequency Applications

    NASA Astrophysics Data System (ADS)

    Velhal, Ninad B.; Patil, Narayan D.; Puri, Vijaya R.

    2015-12-01

    Polypyrrole (Ppy) thin films on alumina were synthesized by an in situ chemical oxidative polymerization method at 300 K with equal monomer-to-oxidant ratio. Fourier transform infrared spectroscopy (FTIR) and FT-Raman spectroscopy confirmed the formation of Ppy. A thickness-dependent change from cauliflower to fish-scale morphology was observed. Microwave properties such as transmission, reflection, shielding effectiveness, permittivity, and microwave conductivity are reported in the frequency range from 8 GHz to 12 GHz. The direct-current (DC) conductivity varied from 9.45 × 10-3 S/cm to 17.29 × 10-3 S/cm, whereas the microwave conductivity varied from 63.07 S/cm to 349.08 S/cm. The shielding effectiveness varied between 6.18 dB and 10.39 dB.

  11. Spirally Structured Conductive Composites for Highly Stretchable, Robust Conductors and Sensors.

    PubMed

    Wu, Xiaodong; Han, Yangyang; Zhang, Xinxing; Lu, Canhui

    2017-07-12

    Flexible and stretchable electronics are highly desirable for next generation devices. However, stretchability and conductivity are fundamentally difficult to combine for conventional conductive composites, which restricts their widespread applications especially as stretchable electronics. Here, we innovatively develop a new class of highly stretchable and robust conductive composites via a simple and scalable structural approach. Briefly, carbon nanotubes are spray-coated onto a self-adhesive rubber film, followed by rolling up the film completely to create a spirally layered structure within the composites. This unique spirally layered structure breaks the typical trade-off between stretchability and conductivity of traditional conductive composites and, more importantly, restrains the generation and propagation of mechanical microcracks in the conductive layer under strain. Benefiting from such structure-induced advantages, the spirally layered composites exhibit high stretchability and flexibility, good conductive stability, and excellent robustness, enabling the composites to serve as highly stretchable conductors (up to 300% strain), versatile sensors for monitoring both subtle and large human activities, and functional threads for wearable electronics. This novel and efficient methodology provides a new design philosophy for manufacturing not only stretchable conductors and sensors but also other stretchable electronics, such as transistors, generators, artificial muscles, etc.

  12. Interventions to increase adherence to medications for tobacco dependence.

    PubMed

    Hollands, Gareth J; McDermott, Máirtín S; Lindson-Hawley, Nicola; Vogt, Florian; Farley, Amanda; Aveyard, Paul

    2015-02-23

    Pharmacological treatments for tobacco dependence, such as nicotine replacement therapy (NRT), have been shown to be safe and effective interventions for smoking cessation. Higher levels of adherence to these medications increase the likelihood of sustained smoking cessation, but many smokers use them at a lower dose and for less time than is optimal. It is therefore important to determine the effectiveness of interventions designed specifically to increase medication adherence. Such interventions may include further educating individuals about the value of taking medications and providing additional support to overcome problems with maintaining adherence. The primary objective of this review was to assess the effectiveness of interventions to increase adherence to medications for smoking cessation, such as NRT, bupropion, nortriptyline and varenicline (and combination regimens). This was considered in comparison to a control group, typically representing standard care. Secondary objectives were to i) assess which intervention approaches are most effective; ii) determine the impact of interventions on potential precursors of adherence, such as understanding of the treatment and efficacy perceptions; and iii) evaluate key outcomes influenced by prior adherence, principally smoking cessation. We searched the following databases using keywords and medical subject headings: Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library), MEDLINE (OVID SP) (1946 to July Week 3 2014), EMBASE (OVID SP) (1980 to Week 29 2014), and PsycINFO (OVID SP) (1806 to July Week 4 2014). The Cochrane Tobacco Addiction Group Specialized Register was searched on 9th July 2014. We conducted forward and backward citation searches. Randomised, cluster-randomised or quasi-randomised studies in which participants using active pharmacological treatment for smoking cessation are allocated to an intervention arm or a control arm. Eligible participants were adult (18+) smokers

  13. Association Between Adherence to Glasses Wearing During Amblyopia Treatment and Improvement in Visual Acuity.

    PubMed

    Maconachie, Gail D E; Farooq, Shegufta; Bush, Glen; Kempton, Julie; Proudlock, Frank A; Gottlob, Irene

    2016-12-01

    Occlusion dose monitors have helped establish that better adherence to occlusion is associated with improved visual outcomes in patients undergoing amblyopia treatment. However, the role of adherence to glasses wearing is unknown. To establish the feasibility and reliability of objectively monitoring adherence to glasses wearing using age-based norms, establish the association between adherence to glasses wearing and improvement in visual acuity (VA) after optical treatment and occlusion therapy, and analyze the effect of age, sex, refractive errors, type of amblyopia, and adherence to glasses wearing on improvement in VA. A prospective, observational, nonmasked, cohort study was conducted between June 8, 2008, and June 30, 2013, among patients at a pediatric ophthalmology clinic of a tertiary care hospital who were newly diagnosed with anisometropic and/or strabismic amblyopia and had not undergone previous treatment. The study consisted of a glasses phase (18 weeks) and a patching phase (glasses and occlusion for 10 hours per day for 12 weeks). Reliability of the glasses monitors was assessed by comparing diary entries and monitor recordings in adults. Objective monitoring of glasses wearing and occlusion. Adherence to glasses wearing (hours per day) and effect on VA. Among 20 children with anisometropia (mean [SD] age, 6.20 [2.16] years; 11 boys and 9 girls) and 20 with strabismic or mixed amblyopia (mean [SD] age, 4.90 [1.36] years; 10 boys and 10 girls), adherence to glasses wearing was successfully monitored in all but 1 patient. Agreement between diaries and monitored times wearing glasses in adults was high (intraclass correlation coefficient, 1.00; 95% CI, 0.999-1.00). Median (SD) adherence to glasses wearing was 70% (25.3%). A moderate correlation was observed between adherence to glasses wearing and percentage improvement in VA during the glasses phase (r = 0.462; P = .003). Multiple regression revealed that age (β = -0.535; P = .001

  14. Factors Influencing Antiretroviral Adherence and Virological Outcomes in People Living with HIV in the Highlands of Papua New Guinea.

    PubMed

    Gare, Janet; Kelly-Hanku, Angela; Ryan, Claire E; David, Matthew; Kaima, Petronia; Imara, Ulato; Lote, Namarola; Crowe, Suzanne M; Hearps, Anna C

    2015-01-01

    Adherence to antiretroviral therapy (ART) is paramount for virological suppression and positive treatment outcomes. ART has been rapidly scaled up in Papua New Guinea (PNG) in recent years, however clinical monitoring of HIV+ individuals on ART is limited. A cross-sectional study was conducted at two major sexual health clinics in high HIV prevalence provinces in the Highlands Region of PNG to assess ART adherence, factors affecting adherence and the relationship between ART adherence and virological outcomes. Ninety-five HIV+ individuals were recruited and administered a questionnaire to gather demographic and ART adherence information whilst clinical data and pill counts were extracted from patient charts and blood was collected for viral load testing. Bivariate analysis was performed to identify independent predictors of ART adherence. Fourteen percent (n = 12) of participants showed evidence of virological failure. Although the majority of participants self-reported excellent ART adherence in the last seven days (78.9%, 75/91), pill count measurements indicated only 40% (34/84) with >95% adherence in the last month. Taking other medications while on ART (p = 0.01) and taking ART for ≥1 year (p = 0.037) were positively associated with adherence by self-report and pill count, respectively. Participants who had never heard of drug resistance were more likely to show virological failure (p = 0.033). Misconception on routes of HIV transmission still persists in the studied population. These findings indicate that non-adherence to ART is high in this region of PNG and continued education and strategies to improve adherence are required to ensure the efficacy of ART and prevent HIV drug resistance.

  15. Factors Influencing Antiretroviral Adherence and Virological Outcomes in People Living with HIV in the Highlands of Papua New Guinea

    PubMed Central

    Gare, Janet; Kelly-Hanku, Angela; Ryan, Claire E.; David, Matthew; Kaima, Petronia; Imara, Ulato; Lote, Namarola; Crowe, Suzanne M.; Hearps, Anna C.

    2015-01-01

    Adherence to antiretroviral therapy (ART) is paramount for virological suppression and positive treatment outcomes. ART has been rapidly scaled up in Papua New Guinea (PNG) in recent years, however clinical monitoring of HIV+ individuals on ART is limited. A cross-sectional study was conducted at two major sexual health clinics in high HIV prevalence provinces in the Highlands Region of PNG to assess ART adherence, factors affecting adherence and the relationship between ART adherence and virological outcomes. Ninety-five HIV+ individuals were recruited and administered a questionnaire to gather demographic and ART adherence information whilst clinical data and pill counts were extracted from patient charts and blood was collected for viral load testing. Bivariate analysis was performed to identify independent predictors of ART adherence. Fourteen percent (n = 12) of participants showed evidence of virological failure. Although the majority of participants self-reported excellent ART adherence in the last seven days (78.9%, 75/91), pill count measurements indicated only 40% (34/84) with >95% adherence in the last month. Taking other medications while on ART (p = 0.01) and taking ART for ≥1 year (p = 0.037) were positively associated with adherence by self-report and pill count, respectively. Participants who had never heard of drug resistance were more likely to show virological failure (p = 0.033). Misconception on routes of HIV transmission still persists in the studied population. These findings indicate that non-adherence to ART is high in this region of PNG and continued education and strategies to improve adherence are required to ensure the efficacy of ART and prevent HIV drug resistance. PMID:26244516

  16. Highly conductive graphene by low-temperature thermal reduction and in situ preparation of conductive polymer nanocomposites.

    PubMed

    Yang, Liping; Kong, Junhua; Yee, Wu Aik; Liu, Wanshuang; Phua, Si Lei; Toh, Cher Ling; Huang, Shu; Lu, Xuehong

    2012-08-21

    Polydopamine-coated graphene oxide (DGO) films exhibit electrical conductivities of 11,000 S m(-1) and 30,000 S m(-1) upon vacuum annealing at 130 °C and 180 °C, respectively. Conductive poly(vinyl alcohol)/graphene and epoxy/graphene nanocomposites show low percolation thresholds due to the excellent dispersibility of the DGO sheets and their effective in situ reduction.

  17. Composite material having high thermal conductivity and process for fabricating same

    DOEpatents

    Colella, Nicholas J.; Davidson, Howard L.; Kerns, John A.; Makowiecki, Daniel M.

    1998-01-01

    A process for fabricating a composite material such as that having high thermal conductivity and having specific application as a heat sink or heat spreader for high density integrated circuits. The composite material produced by this process has a thermal conductivity between that of diamond and copper, and basically consists of coated diamond particles dispersed in a high conductivity metal, such as copper. The composite material can be fabricated in small or relatively large sizes using inexpensive materials. The process basically consists, for example, of sputter coating diamond powder with several elements, including a carbide forming element and a brazeable material, compacting them into a porous body, and infiltrating the porous body with a suitable braze material, such as copper-silver alloy, thereby producing a dense diamond-copper composite material with a thermal conductivity comparable to synthetic diamond films at a fraction of the cost.

  18. Composite material having high thermal conductivity and process for fabricating same

    DOEpatents

    Colella, N.J.; Davidson, H.L.; Kerns, J.A.; Makowiecki, D.M.

    1998-07-21

    A process is disclosed for fabricating a composite material such as that having high thermal conductivity and having specific application as a heat sink or heat spreader for high density integrated circuits. The composite material produced by this process has a thermal conductivity between that of diamond and copper, and basically consists of coated diamond particles dispersed in a high conductivity metal, such as copper. The composite material can be fabricated in small or relatively large sizes using inexpensive materials. The process basically consists, for example, of sputter coating diamond powder with several elements, including a carbide forming element and a brazeable material, compacting them into a porous body, and infiltrating the porous body with a suitable braze material, such as copper-silver alloy, thereby producing a dense diamond-copper composite material with a thermal conductivity comparable to synthetic diamond films at a fraction of the cost. 7 figs.

  19. Printable elastic conductors with a high conductivity for electronic textile applications

    NASA Astrophysics Data System (ADS)

    Matsuhisa, Naoji; Kaltenbrunner, Martin; Yokota, Tomoyuki; Jinno, Hiroaki; Kuribara, Kazunori; Sekitani, Tsuyoshi; Someya, Takao

    2015-06-01

    The development of advanced flexible large-area electronics such as flexible displays and sensors will thrive on engineered functional ink formulations for printed electronics where the spontaneous arrangement of molecules aids the printing processes. Here we report a printable elastic conductor with a high initial conductivity of 738 S cm-1 and a record high conductivity of 182 S cm-1 when stretched to 215% strain. The elastic conductor ink is comprised of Ag flakes, a fluorine rubber and a fluorine surfactant. The fluorine surfactant constitutes a key component which directs the formation of surface-localized conductive networks in the printed elastic conductor, leading to a high conductivity and stretchability. We demonstrate the feasibility of our inks by fabricating a stretchable organic transistor active matrix on a rubbery stretchability-gradient substrate with unimpaired functionality when stretched to 110%, and a wearable electromyogram sensor printed onto a textile garment.

  20. Printable elastic conductors with a high conductivity for electronic textile applications.

    PubMed

    Matsuhisa, Naoji; Kaltenbrunner, Martin; Yokota, Tomoyuki; Jinno, Hiroaki; Kuribara, Kazunori; Sekitani, Tsuyoshi; Someya, Takao

    2015-06-25

    The development of advanced flexible large-area electronics such as flexible displays and sensors will thrive on engineered functional ink formulations for printed electronics where the spontaneous arrangement of molecules aids the printing processes. Here we report a printable elastic conductor with a high initial conductivity of 738 S cm(-1) and a record high conductivity of 182 S cm(-1) when stretched to 215% strain. The elastic conductor ink is comprised of Ag flakes, a fluorine rubber and a fluorine surfactant. The fluorine surfactant constitutes a key component which directs the formation of surface-localized conductive networks in the printed elastic conductor, leading to a high conductivity and stretchability. We demonstrate the feasibility of our inks by fabricating a stretchable organic transistor active matrix on a rubbery stretchability-gradient substrate with unimpaired functionality when stretched to 110%, and a wearable electromyogram sensor printed onto a textile garment.

  1. Printable elastic conductors with a high conductivity for electronic textile applications

    PubMed Central

    Matsuhisa, Naoji; Kaltenbrunner, Martin; Yokota, Tomoyuki; Jinno, Hiroaki; Kuribara, Kazunori; Sekitani, Tsuyoshi; Someya, Takao

    2015-01-01

    The development of advanced flexible large-area electronics such as flexible displays and sensors will thrive on engineered functional ink formulations for printed electronics where the spontaneous arrangement of molecules aids the printing processes. Here we report a printable elastic conductor with a high initial conductivity of 738 S cm−1 and a record high conductivity of 182 S cm−1 when stretched to 215% strain. The elastic conductor ink is comprised of Ag flakes, a fluorine rubber and a fluorine surfactant. The fluorine surfactant constitutes a key component which directs the formation of surface-localized conductive networks in the printed elastic conductor, leading to a high conductivity and stretchability. We demonstrate the feasibility of our inks by fabricating a stretchable organic transistor active matrix on a rubbery stretchability-gradient substrate with unimpaired functionality when stretched to 110%, and a wearable electromyogram sensor printed onto a textile garment. PMID:26109453

  2. Asthma morbidity among inner-city adolescents receiving guidelines-based therapy: Role of predictors in the setting of high adherence

    PubMed Central

    Gruchalla, Rebecca S.; Sampson, Hugh A.; Matsui, Elizabeth; David, Gloria; Gergen, Peter J.; Calatroni, Agustin; Brown, Mark; Liu, Andrew H.; Bloomberg, Gordon R.; Chmiel, James F.; Kumar, Rajesh; Lamm, Carin; Smartt, Ernestine; Sorkness, Christine A.; Steinbach, Suzanne F.; Stone, Kelly D.; Szefler, Stanley J.; Busse, William W.

    2009-01-01

    Background With the expanding effort to provide guidelines-based therapy to adolescents with asthma, attention must be directed to evaluating which factors predict future asthma control when guidelines-based management is applied. Objective We evaluated the role of FeNO, markers of allergic sensitization, airway inflammation and measures of asthma severity in determining future risk of asthma symptoms and exacerbations in adolescents and young adults participating in the Asthma Control Evaluation (ACE) study. Methods Five hundred forty-six inner-city residents, ages 12 through 20 years, with persistent asthma were extensively evaluated at study entry for predictors of future symptoms and exacerbations over the subsequent 46-weeks during which guidelines-based, optimal asthma management was offered. Baseline measurements included: FeNO, total IgE, allergen-specific IgE, allergen skin test reactivity, asthma symptoms, lung function, peripheral blood eosinophils, and, for a subset, airway hyperresponsiveness and sputum eosinophils. Results The baseline characteristics we examined accounted for only a small portion of the variance for future maximum symptom days and exacerbations, 11.4% and 12.6%, respectively. Future exacerbations were somewhat predicted by asthma symptoms, albuterol use, previous exacerbations and lung function while maximum symptom days were predicted , also to a modest extent, by symptoms, albuterol use and previous exacerbations but not lung function. Conclusion Our findings demonstrate that the usual predictors of future disease activity have little predictive power when applied to a highly-adherent, persistent asthma population that is receiving guidelines-based care. Thus, new predictors need to be identified that will be able to measure the continued fluctuation of disease that persists in highly adherent, well-treated populations such as the one studied. PMID:19615730

  3. Extraordinarily High Conductivity of Stretchable Fibers of Polyurethane and Silver Nanoflowers.

    PubMed

    Ma, Rujun; Kang, Byeongguk; Cho, Suik; Choi, Minjun; Baik, Seunghyun

    2015-11-24

    Stretchable conductive composites have received considerable attention recently, and they should have high conductivity and mechanical strength. Here we report highly conductive stretchable fibers synthesized by the scalable wet spinning process using flower-shaped silver nanoparticles with nanodisc-shaped petals (Ag nanoflowers) and polyurethane. An extraordinarily high conductivity (41,245 S cm(-1)) was obtained by Ag nanoflowers, which is 2 orders of magnitude greater than that of fibers synthesized using spherical Ag nanoparticles. This was due to the enhanced surface area and vigorous coalescence of nanodisc-shaped petals during the curing process. There was a trade-off relationship between conductivity and stretchability, and the maximum rupture strain was 776%. An analytical model revealed that the enhanced adhesion between Ag nanoflowers and polyurethane provided a high Young's modulus (731.5 MPa) and ultimate strength (39.6 MPa) of the fibers. The fibers exhibited an elastic property after prestretching, and the resistance change of weft-knitted fabric was negligible up to 200% strain. The fibers with extraordinarily high conductivity, stretchability, and mechanical strength may be useful for wearable electronics applications.

  4. Improving Blood Pressure Control through a Clinical Pharmacist Outreach Program in Diabetes Patients in Two-High Performing Health Systems: The Adherence and Intensification of Medications (AIM) Cluster Randomized Controlled Pragmatic Trial

    PubMed Central

    Heisler, Michele; Hofer, Timothy P.; Schmittdiel, Julie A.; Selby, Joe V.; Klamerus, Mandi L.; Bosworth, Hayden B.; Bermann, Martin; Kerr, Eve A.

    2013-01-01

    Background Even in high performing health systems, some hypertensive patients with diabetes have persistent poor blood pressure (BP) control. Medication nonadherence and lack of medication intensification contribute to this poor control. We examined whether the Adherence and Intensification of Medications (AIM) intervention, a targeted pharmacist-led intervention that combined state-of-the-art elements found in efficacy studies to lower BP, could improve BP among diabetes patients with persistent hypertension and poor refill adherence or insufficient medication intensification. Methods and Results We conducted a prospective, multi-site cluster randomized pragmatic trial with randomization of 16 primary care teams at five medical centers (3 Veterans Affairs [VA] and 2 Kaiser Permanente [KP]) to the AIM intervention or usual care. The primary outcome was the relative change in systolic blood pressure (SBP) measurements, comparing 1,797 eligible intervention team patients to 2,303 eligible control team patients, between the 6-months preceding and the 6-months following the 14-month intervention period. We examined shorter-term changes in SBP as a secondary outcome. In our primary analysis, the intervention group SBP change from 6-months prior to 6-months after the 14-month intervention period was approximately the same as the control group, declining approximately 9 mm Hg in both groups. SBP lowering occurred more rapidly among eligible intervention team patients, with mean SBPs 2.4 mm Hg lower (95% CI: −3.4 to −1.5; p<.001) immediately after the intervention than those achieved by eligible control patients. Conclusions The AIM program more rapidly lowered SBPs among eligible intervention patients, but there was no significant difference in blood pressure between intervention and control patients 6 months following the intervention period. These findings show the importance of rigorously evaluating in different real-life clinical settings programs found in

  5. Improving Patient's Primary Medication Adherence

    PubMed Central

    Leguelinel-Blache, Géraldine; Dubois, Florent; Bouvet, Sophie; Roux-Marson, Clarisse; Arnaud, Fabrice; Castelli, Christel; Ray, Valérie; Kinowski, Jean-Marie; Sotto, Albert

    2015-01-01

    Abstract Quality of transitions of care is one of the first concerns in patient safety. Redesigning the discharge process to incorporate clinical pharmacy activities could reduce the incidence of postdischarge adverse events by improving medication adherence. The present study investigated the value of pharmacist counseling sessions on primary medication adherence after hospital discharge. This study was conducted in a 1844-bed hospital in France. It was divided in an observational period and an interventional period of 3 months each. In both periods, ward-based clinical pharmacists performed medication reconciliation and inpatient follow-up. In interventional period, initial counseling and discharge counseling sessions were added to pharmaceutical care. The primary medication adherence was assessed by calling community pharmacists 7 days after patient discharge. We compared the measure of adherence between the patients from the observational period (n = 201) and the interventional period (n = 193). The rate of patients who were adherent increased from 51.0% to 66.7% between both periods (P < 0.01). When discharge counseling was performed (n = 78), this rate rose to 79.7% (P < 0.001). The multivariate regression performed on data from both periods showed that age of at least 78 years old, and 3 or less new medications on discharge order were predictive factors of adherence. New medications ordered at discharge represented 42.0% (n = 1018/2426) of all medications on discharge order. The rate of unfilled new medications decreased from 50.2% in the observational period to 32.5% in the interventional period (P < 10−7). However, patients included in the observational period were not significantly more often readmitted or visited the emergency department than the patients who experienced discharge counseling during the interventional period (45.3% vs. 46.2%; P = 0.89). This study highlights that discharge counseling sessions are

  6. Exercise Adherence. ERIC Digest.

    ERIC Educational Resources Information Center

    Sullivan, Pat

    This digest discusses exercise adherence, noting its vital role in maximizing the benefits associated with physical activity. Information is presented on the following: (1) factors that influence adherence to self-monitored programs of regular exercise (childhood eating habits, and psychological, physical, social, and situational factors); (2)…

  7. A robust, highly stretchable supramolecular polymer conductive hydrogel with self-healability and thermo-processability.

    PubMed

    Wu, Qian; Wei, Junjie; Xu, Bing; Liu, Xinhua; Wang, Hongbo; Wang, Wei; Wang, Qigang; Liu, Wenguang

    2017-01-30

    Dual amide hydrogen bond crosslinked and strengthened high strength supramolecular polymer conductive hydrogels were fabricated by simply in situ doping poly (N-acryloyl glycinamide-co-2-acrylamide-2-methylpropanesulfonic) (PNAGA-PAMPS) hydrogels with PEDOT/PSS. The nonswellable conductive hydrogels in PBS demonstrated high mechanical performances-0.22-0.58 MPa tensile strength, 1.02-7.62 MPa compressive strength, and 817-1709% breaking strain. The doping of PEDOT/PSS could significantly improve the specific conductivities of the hydrogels. Cyclic heating and cooling could lead to reversible sol-gel transition and self-healability due to the dynamic breakup and reconstruction of hydrogen bonds. The mending hydrogels recovered not only the mechanical properties, but also conductivities very well. These supramolecular conductive hydrogels could be designed into arbitrary shapes with 3D printing technique, and further, printable electrode can be obtained by blending activated charcoal powder with PNAGA-PAMPS/PEDOT/PSS hydrogel under melting state. The fabricated supercapacitor via the conducting hydrogel electrodes possessed high capacitive performances. These cytocompatible conductive hydrogels have a great potential to be used as electro-active and electrical biomaterials.

  8. A robust, highly stretchable supramolecular polymer conductive hydrogel with self-healability and thermo-processability

    PubMed Central

    Wu, Qian; Wei, Junjie; Xu, Bing; Liu, Xinhua; Wang, Hongbo; Wang, Wei; Wang, Qigang; Liu, Wenguang

    2017-01-01

    Dual amide hydrogen bond crosslinked and strengthened high strength supramolecular polymer conductive hydrogels were fabricated by simply in situ doping poly (N-acryloyl glycinamide-co-2-acrylamide-2-methylpropanesulfonic) (PNAGA-PAMPS) hydrogels with PEDOT/PSS. The nonswellable conductive hydrogels in PBS demonstrated high mechanical performances—0.22–0.58 MPa tensile strength, 1.02–7.62 MPa compressive strength, and 817–1709% breaking strain. The doping of PEDOT/PSS could significantly improve the specific conductivities of the hydrogels. Cyclic heating and cooling could lead to reversible sol-gel transition and self-healability due to the dynamic breakup and reconstruction of hydrogen bonds. The mending hydrogels recovered not only the mechanical properties, but also conductivities very well. These supramolecular conductive hydrogels could be designed into arbitrary shapes with 3D printing technique, and further, printable electrode can be obtained by blending activated charcoal powder with PNAGA-PAMPS/PEDOT/PSS hydrogel under melting state. The fabricated supercapacitor via the conducting hydrogel electrodes possessed high capacitive performances. These cytocompatible conductive hydrogels have a great potential to be used as electro-active and electrical biomaterials. PMID:28134283

  9. A robust, highly stretchable supramolecular polymer conductive hydrogel with self-healability and thermo-processability

    NASA Astrophysics Data System (ADS)

    Wu, Qian; Wei, Junjie; Xu, Bing; Liu, Xinhua; Wang, Hongbo; Wang, Wei; Wang, Qigang; Liu, Wenguang

    2017-01-01

    Dual amide hydrogen bond crosslinked and strengthened high strength supramolecular polymer conductive hydrogels were fabricated by simply in situ doping poly (N-acryloyl glycinamide-co-2-acrylamide-2-methylpropanesulfonic) (PNAGA-PAMPS) hydrogels with PEDOT/PSS. The nonswellable conductive hydrogels in PBS demonstrated high mechanical performances—0.22–0.58 MPa tensile strength, 1.02–7.62 MPa compressive strength, and 817–1709% breaking strain. The doping of PEDOT/PSS could significantly improve the specific conductivities of the hydrogels. Cyclic heating and cooling could lead to reversible sol-gel transition and self-healability due to the dynamic breakup and reconstruction of hydrogen bonds. The mending hydrogels recovered not only the mechanical properties, but also conductivities very well. These supramolecular conductive hydrogels could be designed into arbitrary shapes with 3D printing technique, and further, printable electrode can be obtained by blending activated charcoal powder with PNAGA-PAMPS/PEDOT/PSS hydrogel under melting state. The fabricated supercapacitor via the conducting hydrogel electrodes possessed high capacitive performances. These cytocompatible conductive hydrogels have a great potential to be used as electro-active and electrical biomaterials.

  10. Dehydration of chlorite explains anomalously high electrical conductivity in the mantle wedges

    PubMed Central

    Manthilake, Geeth; Bolfan-Casanova, Nathalie; Novella, Davide; Mookherjee, Mainak; Andrault, Denis

    2016-01-01

    Mantle wedge regions in subduction zone settings show anomalously high electrical conductivity (~1 S/m) that has often been attributed to the presence of aqueous fluids released by slab dehydration. Laboratory-based measurements of the electrical conductivity of hydrous phases and aqueous fluids are significantly lower and cannot readily explain the geophysically observed anomalously high electrical conductivity. The released aqueous fluid also rehydrates the mantle wedge and stabilizes a suite of hydrous phases, including serpentine and chlorite. In this present study, we have measured the electrical conductivity of a natural chlorite at pressures and temperatures relevant for the subduction zone setting. In our experiment, we observe two distinct conductivity enhancements when chlorite is heated to temperatures beyond its thermodynamic stability field. The initial increase in electrical conductivity to ~3 × 10−3 S/m can be attributed to chlorite dehydration and the release of aqueous fluids. This is followed by a unique, subsequent enhancement of electrical conductivity of up to 7 × 10−1 S/m. This is related to the growth of an interconnected network of a highly conductive and chemically impure magnetite mineral phase. Thus, the dehydration of chlorite and associated processes are likely to be crucial in explaining the anomalously high electrical conductivity observed in mantle wedges. Chlorite dehydration in the mantle wedge provides an additional source of aqueous fluid above the slab and could also be responsible for the fixed depth (120 ± 40 km) of melting at the top of the subducting slab beneath the subduction-related volcanic arc front. PMID:27386526

  11. High Thermal Conductivity NARloy-Z-Diamond Composite Combustion Chamber Liner For Advanced Rocket Engines

    NASA Technical Reports Server (NTRS)

    Bhat, Biliyar N.; Ellis, David; Singh, Jogender

    2014-01-01

    Advanced high thermal conductivity materials research conducted at NASA Marshall Space Flight Center (MSFC) with state of the art combustion chamber liner material NARloy-Z showed that its thermal conductivity can be increased significantly by adding diamond particles and sintering it at high temperatures. For instance, NARloy-Z containing 40 vol. percent diamond particles, sintered at 975C to full density by using the Field assisted Sintering Technology (FAST) showed 69 percent higher thermal conductivity than baseline NARloy-Z. Furthermore, NARloy-Z-40vol. percent D is 30 percent lighter than NARloy-Z and hence the density normalized thermal conductivity is 140 percent better. These attributes will improve the performance and life of the advanced rocket engines significantly. By one estimate, increased thermal conductivity will directly translate into increased turbopump power up to 2X and increased chamber pressure for improved thrust and ISP, resulting in an expected 20 percent improvement in engine performance. Follow on research is now being conducted to demonstrate the benefits of this high thermal conductivity NARloy-Z-D composite for combustion chamber liner applications in advanced rocket engines. The work consists of a) Optimizing the chemistry and heat treatment for NARloy-Z-D composite, b) Developing design properties (thermal and mechanical) for the optimized NARloy-Z-D, c) Fabrication of net shape subscale combustion chamber liner, and d) Hot fire testing of the liner for performance. FAST is used for consolidating and sintering NARlo-Z-D. The subscale cylindrical liner with built in channels for coolant flow is also fabricated near net shape using the FAST process. The liner will be assembled into a test rig and hot fire tested in the MSFC test facility to determine performance. This paper describes the development of this novel high thermal conductivity NARloy-Z-D composite material, and the advanced net shape technology to fabricate the combustion

  12. Dehydration of chlorite explains anomalously high electrical conductivity in the mantle wedges.

    PubMed

    Manthilake, Geeth; Bolfan-Casanova, Nathalie; Novella, Davide; Mookherjee, Mainak; Andrault, Denis

    2016-05-01

    Mantle wedge regions in subduction zone settings show anomalously high electrical conductivity (~1 S/m) that has often been attributed to the presence of aqueous fluids released by slab dehydration. Laboratory-based measurements of the electrical conductivity of hydrous phases and aqueous fluids are significantly lower and cannot readily explain the geophysically observed anomalously high electrical conductivity. The released aqueous fluid also rehydrates the mantle wedge and stabilizes a suite of hydrous phases, including serpentine and chlorite. In this present study, we have measured the electrical conductivity of a natural chlorite at pressures and temperatures relevant for the subduction zone setting. In our experiment, we observe two distinct conductivity enhancements when chlorite is heated to temperatures beyond its thermodynamic stability field. The initial increase in electrical conductivity to ~3 × 10(-3) S/m can be attributed to chlorite dehydration and the release of aqueous fluids. This is followed by a unique, subsequent enhancement of electrical conductivity of up to 7 × 10(-1) S/m. This is related to the growth of an interconnected network of a highly conductive and chemically impure magnetite mineral phase. Thus, the dehydration of chlorite and associated processes are likely to be crucial in explaining the anomalously high electrical conductivity observed in mantle wedges. Chlorite dehydration in the mantle wedge provides an additional source of aqueous fluid above the slab and could also be responsible for the fixed depth (120 ± 40 km) of melting at the top of the subducting slab beneath the subduction-related volcanic arc front.

  13. Anisotropy of synthetic quartz electrical conductivity at high pressure and temperature

    NASA Astrophysics Data System (ADS)

    Wang, Duojun; Li, Heping; Yi, Li; Matsuzaki, Takuya; Yoshino, Takashi

    2010-09-01

    AC measurements of the electrical conductivity of synthetic quartz along various orientations were made between 0.1 and 1 MHz, at ˜855˜1601 K and at 1.0 GPa. In addition, the electrical conductivity of quartz along the c axis has been studied at 1.0-3.0 GPa. The impedance arcs representing bulk conductivity occur in the frequency range of 103-106 Hz, and the electrical responses of the interface between the sample and the electrode occur in the 0.1˜103 Hz range. The pressure has a weak effect on the electrical conductivity. The electrical conductivity experiences no abrupt change near the α - β phase transition point. The electrical conductivity of quartz is highly anisotropic; the electrical conductivity along the c axis is strongest and several orders of magnitude larger than in other directions. The activation enthalpies along various orientations are determined to be 0.6 and 1.2 eV orders of magnitude, respectively. The interpretation of the former is based on the contribution of alkali ions, while the latter effect is attributed to additional unassociated aluminum ions. Comparison of determined anisotropic conductivity of quartz determined with those from field geophysical models shows that the quartz may potentially provide explanations for the behavior of electrical conductivity of anisotropy in the crust that are inferred from the transverse magnetic mode.

  14. Protection of Conductive and Non-conductive Advanced Polymer-based Paints from Highly Aggressive Oxidative Environments

    NASA Technical Reports Server (NTRS)

    Gudimenko, Y.; Ng, R.; Iskanderova, Z.; Kleiman, J.; Grigorevsky, A.; Kiseleva, L.; Finckenor, M.; Edwards, D.

    2005-01-01

    Research has been continued to further improve the space durability of conductive and non-conductive polymer-based paints and of conductive thermal control paints for space applications. Efforts have been made to enhance the space durability and stability of functional Characteristics in ground-based space environment imitating conditions, using specially developed surface modification treatment. The results of surface modification of new conductive paints, including the ground-based testing in aggressive oxidative environments, such as atomic oxygen/UV and oxygen plasma, and performance evaluation are presented. Functional properties and performance characteristics, such as thermal optical properties (differential solar absorptance and thermal emittance representing the thermal optical performance of thermal control paints) and surface resistivity characteristics of pristine, surface modified, and tested materials were verified. Extensive surface analysis studies have been performed using complementary surface analyses including SEM/EDS and XPS. Test results revealed that the successfully treated materials exhibit reduced mass loss and no surface morphology change, thus indicating good protection from the severe oxidative environment. It was demonstrated that the developed surface modification treatment could be applied successfully to charge dissipative and conductive paints.

  15. High Conductivity Materials for High Heat Flux Applications in Space Propulsion Systems

    NASA Technical Reports Server (NTRS)

    Nathal, M. V.; Ellis, D. L.; Loewenthal, W. S.; Raj, S. V.; Thomas-Ogbuji, L. U.; Ghosn, J.; Greenbauer-Seng, L. A.; Gayda, J.; Barrett, C. A.

    2003-01-01

    GRCop-84 is a new copper base alloy with an excellent combination of strength and conductivity and has been developed to the point that it is a strong candidate for near term rocket engine applications. This work sought to establish the feasibility of new alloys with capabilities beyond GRCop-84. The use of coatings as environmental and thermal barriers adds further capability into the Copper base structure. Finally, Nickel-Aluminum based systems have also been explored.

  16. High-performance electrically conductive silver paste prepared by silver-containing precursor

    NASA Astrophysics Data System (ADS)

    Liu, Jianguo; Cao, Yu; Li, Xiangyou; Wang, Xiaoye; Zeng, Xiaoyan

    2010-09-01

    A high-performance electrically conductive silver paste with no solid particles before drying and/or sintering is developed, in which silver-containing precursor is employed as conductive functional phase. Thermogravimetry analysis, volume electrical resistivity tests and sintering experiments show that the paste with about 14 wt.% silver pristine content is able to achieve the volume electrical resistivity of (2-3) ×10-5 Ω cm after it is sintered at 220°C. A micro-pen direct-writing process indicates that it is very suitable for the fabrication of high-resolution (25 μm) and high-integration devices and apparatus.

  17. Development of Low Conductivity and Ultra High Temperature Ceramic Coatings Using A High-Heat-Flux Testing Approach

    NASA Technical Reports Server (NTRS)

    Zhu, Dongming; Miller, Robert A.

    1990-01-01

    The development of low conductivity, robust thermal and environmental barrier coatings requires advanced testing techniques that can accurately and effectively evaluate coating thermal conductivity and cyclic resistance at very high surface temperatures (up to 17OOOC) under large thermal gradients. In this study, a laser high-heat-flux test approach is established for evaluating advanced low conductivity, ultra-high temperature ceramic thermal and environmental barrier coatings under the NASA Ultra Efficient Engine Technology (UEET) program. The test approach emphasizes the real-time monitoring and assessment of the coating thermal conductivity: the initial conductivity rise under a steady-state high temperature thermal gradient test due to coating sintering, and the later coating conductivity reduction under a subsequent cyclic thermal gradient test due to coating cracking/delamination. The coating system is then evaluated based on the damage accumulations and failure after the combined steady-state and cyclic thermal gradient tests. The lattice and radiation thermal conductivity of advanced ceramic coatings can also be evaluated using laser heat-flux techniques. The coating external radiation resistance is assessed based on the measured specimen temperature response under a laser heated intense radiation flux source. The coating internal radiation contribution is investigated based on the measured apparent coating conductivity increases with the coating surface test temperature under large thermal gradient test conditions. Since an increased radiation contribution is observed at these very high surface test temperatures, by varying the laser heat-flux and coating average test temperature, the complex relation between the lattice and radiation conductivity as a function of surface and interface test temperature is derived.

  18. Development of Low Conductivity and Ultra High Temperature Ceramic Coatings Using A High-Heat-Flux Testing Approach

    NASA Technical Reports Server (NTRS)

    Zhu, Dongming; Miller, Robert A.

    1990-01-01

    The development of low conductivity, robust thermal and environmental barrier coatings requires advanced testing techniques that can accurately and effectively evaluate coating thermal conductivity and cyclic resistance at very high surface temperatures (up to 17OOOC) under large thermal gradients. In this study, a laser high-heat-flux test approach is established for evaluating advanced low conductivity, ultra-high temperature ceramic thermal and environmental barrier coatings under the NASA Ultra Efficient Engine Technology (UEET) program. The test approach emphasizes the real-time monitoring and assessment of the coating thermal conductivity: the initial conductivity rise under a steady-state high temperature thermal gradient test due to coating sintering, and the later coating conductivity reduction under a subsequent cyclic thermal gradient test due to coating cracking/delamination. The coating system is then evaluated based on the damage accumulations and failure after the combined steady-state and cyclic thermal gradient tests. The lattice and radiation thermal conductivity of advanced ceramic coatings can also be evaluated using laser heat-flux techniques. The coating external radiation resistance is assessed based on the measured specimen temperature response under a laser heated intense radiation flux source. The coating internal radiation contribution is investigated based on the measured apparent coating conductivity increases with the coating surface test temperature under large thermal gradient test conditions. Since an increased radiation contribution is observed at these very high surface test temperatures, by varying the laser heat-flux and coating average test temperature, the complex relation between the lattice and radiation conductivity as a function of surface and interface test temperature is derived.

  19. Handbook of Instructions for Conducting Follow-Up Studies of High School Graduates. Book I.

    ERIC Educational Resources Information Center

    Donaldson, Evelyn T. Comp.; And Others

    This handbook is designed to enable high schools to conduct follow-up studies on their graduates for 5 years after graduation. The information gathered should give schools pertinent data about: (1) post high school activities of graduates; (2) reactions of graduates to counseling and guidance opportunities; (3) reactions of graduates to…

  20. Development of high pressure-high vacuum-high conductance piston valve for gas-filled radiation detectors

    NASA Astrophysics Data System (ADS)

    Prasad, D. N.; Ayyappan, R.; Kamble, L. P.; Singh, J. P.; Muralikrishna, L. V.; Alex, M.; Balagi, V.; Mukhopadhyay, P. K.

    2008-05-01

    Gas-filled radiation detectors need gas filling at pressures that range from few cms of mercury to as high as 25kg/cm2 at room temperature. Before gas-filling these detectors require evacuation to a vacuum of the order of ~1 × 10-5 mbar. For these operations of evacuation and gas filling a system consisting of a vacuum pump with a high vacuum gauge, gas cylinder with a pressure gauge and a valve is used. The valve has to meet the three requirements of compatibility with high-pressure and high vacuum and high conductance. A piston valve suitable for the evacuation and gas filling of radiation detectors has been designed and fabricated to meet the above requirements. The stainless steel body (80mm×160mm overall dimensions) valve with a piston arrangement has a 1/2 inch inlet/outlet opening, neoprene/viton O-ring at piston face & diameter for sealing and a knob for opening and closing the valve. The piston movement mechanism is designed to have minimum wear of sealing O-rings. The valve has been hydrostatic pressure tested up to 75bars and has Helium leak rate of less than 9.6×10-9 m bar ltr/sec in vacuum mode and 2×10-7 mbar ltr/sec in pressure mode. As compared to a commercial diaphragm valve, which needed 3 hours to evacuate a 7 litre chamber to 2.5×10-5 mbar, the new valve achieved vacuum 7.4×10-6mbar in the same time under the same conditions.

  1. HIGH PROTON CONDUCTIVITY OF MESOPOROUS Al2O3

    NASA Astrophysics Data System (ADS)

    Shen, Hangyan; Maekawa, Hideki; Fujimaki, Yutaka; Kawada, Koutaro; Yamamura, Tsutomu

    Mesoporous Al2O3 was synthesized by the sol-gel method and the pore size was controlled over the range of 3-15nm. Proton conductivity of these samples was examined, which was as high as 0.004 S·cm-1 at 25°C. A systematic dependence of conductivity upon pore size was observed, in which the conductivity increased with increasing the pore size. Meanwhile the conductivity increased with increasing the humidity. Two peaks were observed in 1H NMR spectra, assigned to a "mobile" and an "immobile" proton, respectively. It can be seen that the conductivity of mesoporous-Al2O3 increased with increasing the "mobile" proton concentration. From TG-DTA measurement, proton species were categorized into three groups. It is suggested the group II protons have close relation with the NMR observed "mobile" protons.

  2. Equivalent Thermal Conductivity of Open-Cell Ceramic Foams at High Temperatures

    NASA Astrophysics Data System (ADS)

    Li, J. E.; Wang, B.

    2014-01-01

    At high temperature, heat transfer in open-cell foams occurs by thermal radiation through the whole medium as well as by conduction through the solid matrix and air filling the pores. This paper applies the body-centered cubic cell model to predict radiative properties and the thermal conductivity of the open-cell foams. The model is validated by comparing the results with previous published works. Effects of structural characteristic parameters (cell diameter and porosity) and optical properties of the solid matrix (reflectivity and specularity parameter) on extinction coefficients and the radiative conductivity are discussed. The influence of temperature on the thermal conductivities including the effective, radiative, and the equivalent conductivity of open-cell ceramic foams are analyzed.

  3. Heat Pipe Embedded AlSiC Plates for High Conductivity - Low CTE Heat Spreaders

    SciTech Connect

    Johnson, Matthew ); Weyant, J.; Garner, S. ); Occhionero, M. )

    2010-01-07

    Heat pipe embedded aluminum silicon carbide (AlSiC) plates are innovative heat spreaders that provide high thermal conductivity and low coefficient of thermal expansion (CTE). Since heat pipes are two phase devices, they demonstrate effective thermal conductivities ranging between 50,000 and 200,000 W/m-K, depending on the heat pipe length. Installing heat pipes into an AlSiC plate dramatically increases the plate’s effective thermal conductivity. AlSiC plates alone have a thermal conductivity of roughly 200 W/m-K and a CTE ranging from 7-12 ppm/ deg C, similar to that of silicon. An equivalent sized heat pipe embedded AlSiC plate has effective thermal conductivity ranging from 400 to 500 W/m-K and retains the CTE of AlSiC.

  4. Prospects for nanowire-doped polycrystalline graphene films for ultratransparent, highly conductive electrodes.

    PubMed

    Jeong, Changwook; Nair, Pradeep; Khan, Mohammad; Lundstrom, Mark; Alam, Muhammad A

    2011-11-09

    Traditional transparent conducting materials such as ITO are expensive, brittle, and inflexible. Although alternatives like networks of carbon