DOE Office of Scientific and Technical Information (OSTI.GOV)

MANI,SEETHAMBAL S.; FLEMING,JAMES G.; WALRAVEN,JEREMY A.

Two major problems associated with Si-based MEMS (MicroElectroMechanical Systems) devices are stiction and wear. Surface modifications are needed to reduce both adhesion and friction in micromechanical structures to solve these problems. In this paper, the authors present a CVD (Chemical Vapor Deposition) process that selectively coats MEMS devices with tungsten and significantly enhances device durability. Tungsten CVD is used in the integrated-circuit industry, which makes this approach manufacturable. This selective deposition process results in a very conformal coating and can potentially address both stiction and wear problems confronting MEMS processing. The selective deposition of tungsten is accomplished through the siliconmore » reduction of WF{sub 6}. The self-limiting nature of the process ensures consistent process control. The tungsten is deposited after the removal of the sacrificial oxides to minimize stress and process integration problems. The tungsten coating adheres well and is hard and conducting, which enhances performance for numerous devices. Furthermore, since the deposited tungsten infiltrates under adhered silicon parts and the volume of W deposited is less than the amount of Si consumed, it appears to be possible to release adhered parts that are contacted over small areas such as dimples. The wear resistance of tungsten coated parts has been shown to be significantly improved by microengine test structures.« less

Intervention Fidelity for a Complex Behaviour Change Intervention in Community Pharmacy Addressing Cardiovascular Disease Risk

ERIC Educational Resources Information Center

McNamara, K. P.; O'Reilly, S. L.; George, J.; Peterson, G. M.; Jackson, S. L.; Duncan, G.; Howarth, H.; Dunbar, J. A.

2015-01-01

Background: Delivery of cardiovascular disease (CVD) prevention programs by community pharmacists appears effective and enhances health service access. However, their capacity to implement complex behavioural change processes during patient counselling remains largely unexplored. This study aims to determine intervention fidelity by pharmacists…

Factors associated with blue-collar workers' risk perception of cardiovascular disease.

PubMed

Hwang, Won Ju; Hong, Oisaeng; Kim, Mi Ja

2012-12-01

The purpose of this study was to investigate the contribution of actual cardiovascular disease (CVD) risk, as well as, individual, psychosocial, and work-related factors as predictors of CVD risk perception among Korean blue-collar workers. The participants were 238 Korean blue-collar workers who worked in small companies. Data were collected through a survey; anthropometric and blood pressure measures; and blood sampling for lipid levels. Blue-collar workers had high actual CVD risk and low CVD risk perception. The significant predictors of risk perception included perceived health status, alcohol consumption, knowledge of CVD risk, actual CVD risk, decision latitude, and shift work. The model explained 26% of the variance in CVD risk perception. The result suggests when occupational health nurses are giving routine health examination in small companies, they can enhance CVD risk perception in blue-collar workers by providing essential information about CVD risk factors and personal counseling on the individual worker's CVD risk status.

CVD Polymers for Devices and Device Fabrication.

PubMed

Wang, Minghui; Wang, Xiaoxue; Moni, Priya; Liu, Andong; Kim, Do Han; Jo, Won Jun; Sojoudi, Hossein; Gleason, Karen K

2017-03-01

Chemical vapor deposition (CVD) polymerization directly synthesizes organic thin films on a substrate from vapor phase reactants. Dielectric, semiconducting, electrically conducting, and ionically conducting CVD polymers have all been readily integrated into devices. The absence of solvent in the CVD process enables the growth of high-purity layers and avoids the potential of dewetting phenomena, which lead to pinhole defects. By limiting contaminants and defects, ultrathin (<10 nm) CVD polymeric device layers have been fabricated in multiple laboratories. The CVD method is particularly suitable for synthesizing insoluble conductive polymers, layers with high densities of organic functional groups, and robust crosslinked networks. Additionally, CVD polymers are prized for the ability to conformally cover rough surfaces, like those of paper and textile substrates, as well as the complex geometries of micro- and nanostructured devices. By employing low processing temperatures, CVD polymerization avoids damaging substrates and underlying device layers. This report discusses the mechanisms of the major CVD polymerization techniques and the recent progress of their applications in devices and device fabrication, with emphasis on initiated CVD (iCVD) and oxidative CVD (oCVD) polymerization. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Growth of hybrid carbon nanostructures on iron-decorated ZnO nanorods

NASA Astrophysics Data System (ADS)

Mbuyisa, Puleng N.; Rigoni, Federica; Sangaletti, Luigi; Ponzoni, Stefano; Pagliara, Stefania; Goldoni, Andrea; Ndwandwe, Muzi; Cepek, Cinzia

2016-04-01

A novel carbon-based nanostructured material, which includes carbon nanotubes (CNTs), porous carbon, nanostructured ZnO and Fe nanoparticles, has been synthetized using catalytic chemical vapour deposition (CVD) of acetylene on vertically aligned ZnO nanorods (NRs). The deposition of Fe before the CVD process induces the presence of dense CNTs in addition to the variety of nanostructures already observed on the process done on the bare NRs, which range from amorphous graphitic carbon up to nanostructured dendritic carbon films, where the NRs are partially or completely etched. The combination of scanning electron microscopy and in situ photoemission spectroscopy indicate that Fe enhances the ZnO etching, and that the CNT synthesis is favoured by the reduced Fe mobility due to the strong interaction between Fe and the NRs, and to the presence of many defects, formed during the CVD process. Our results demonstrate that the resulting new hybrid shows a higher sensitivity to ammonia gas at ambient conditions (∼60 ppb) than the carbon nanostructures obtained without the aid of Fe, the bare ZnO NRs, or other one-dimensional carbon nanostructures, making this system of potential interest for environmental ammonia monitoring. Finally, in view of the possible application in nanoscale optoelectronics, the photoexcited carrier behaviour in these hybrid systems has been characterized by time-resolved reflectivity measurements.

Gut flora metabolism of phosphatidylcholine promotes cardiovascular disease

PubMed Central

Wang, Zeneng; Klipfell, Elizabeth; Bennett, Brian J.; Koeth, Robert; Levison, Bruce S.; DuGar, Brandon; Feldstein, Ariel E.; Britt, Earl B.; Fu, Xiaoming; Chung, Yoon-Mi; Wu, Yuping; Schauer, Phil; Smith, Jonathan D.; Allayee, Hooman; Tang, W. H. Wilson; DiDonato, Joseph A.; Lusis, Aldons J.; Hazen, Stanley L.

2011-01-01

Metabolomics studies hold promise for discovery of pathways linked to disease processes. Cardiovascular disease (CVD) represents the leading cause of death and morbidity worldwide. A metabolomics approach was used to generate unbiased small molecule metabolic profiles in plasma that predict risk for CVD. Three metabolites of the dietary lipid phosphatidylcholine, namely choline, trimethylamine N-oxide (TMAO), and betaine, were identified and then shown to predict risk for CVD in an independent large clinical cohort. Dietary supplementation of mice with choline, TMAO or betaine promoted up-regulation of multiple macrophage scavenger receptors linked to atherosclerosis, and supplementation with choline or TMAO promoted atherosclerosis. Studies using germ-free mice confirmed a critical role for dietary choline and gut flora in TMAO production, augmented macrophage cholesterol accumulation and foam cell formation. Suppression of intestinal microflora in atherosclerosis-prone mice inhibited dietary choline-enhanced atherosclerosis. Genetic variations controlling expression of flavin monooxygenases (FMOs), an enzymatic source of TMAO, segregated with atherosclerosis in hyperlipidemic mice. Discovery of a relationship between gut flora-dependent metabolism of dietary phosphatidylcholine and CVD pathogenesis provides opportunities for development of both novel diagnostic tests and therapeutic approaches for atherosclerotic heart disease. PMID:21475195

Social-Strata-Related Cardiovascular Health Disparity and Comorbidity in an Aging Society: Implications for Professional Care

ERIC Educational Resources Information Center

Ai, Amy L.; Carrigan, Lynn T.

2007-01-01

Cardiovascular disease (CVD) is on the rise in the aging population of the United States. Heart disease is the leading cause of death, hospital bed use, and social security disability. Enhancing knowledge about CVD may improve social work's professional role in the health care system. This article focuses on a pressing CVD-related issue that needs…

Deposition and micro electrical discharge machining of CVD-diamond layers incorporated with silicon

NASA Astrophysics Data System (ADS)

Kühn, R.; Berger, T.; Prieske, M.; Börner, R.; Hackert-Oschätzchen, M.; Zeidler, H.; Schubert, A.

2017-10-01

In metal forming, lubricants have to be used to prevent corrosion or to reduce friction and tool wear. From an economical and ecological point of view, the aim is to avoid the usage of lubricants. For dry deep drawing of aluminum sheets it is intended to apply locally micro-structured wear-resistant carbon based coatings onto steel tools. One type of these coatings are diamond layers prepared by chemical vapor deposition (CVD). Due to the high strength of diamond, milling processes are unsuitable for micro-structuring of these layers. In contrast to this, micro electrical discharge machining (micro EDM) is a suitable process for micro-structuring CVD-diamond layers. Due to its non-contact nature and its process principle of ablating material by melting and evaporating, it is independent of the hardness, brittleness or toughness of the workpiece material. In this study the deposition and micro electrical discharge machining of silicon incorporated CVD-diamond (Si-CVD-diamond) layers were presented. For this, 10 µm thick layers were deposited on molybdenum plates by a laser-induced plasma CVD process (LaPlas-CVD). For the characterization of the coatings RAMAN- and EDX-analyses were conducted. Experiments in EDM were carried out with a tungsten carbide tool electrode with a diameter of 90 µm to investigate the micro-structuring of Si-CVD-diamond. The impact of voltage, discharge energy and tool polarity on process speed and resulting erosion geometry were analyzed. The results show that micro EDM is a suitable technology for micro-structuring of silicon incorporated CVD-diamond layers.

Canadian-led capacity-building in biostatistics and methodology in cardiovascular and diabetes trials: the CANNeCTIN Biostatistics and Methodological Innovation Working Group

PubMed Central

2011-01-01

The Biostatistics and Methodological Innovation Working (BMIW) Group is one of several working groups within the CANadian Network and Centre for Trials INternationally (CANNeCTIN). This programme received funding from the Canadian Institutes of Health Research and the Canada Foundation for Innovation beginning in 2008, to enhance the infrastructure and build capacity for large Canadian-led clinical trials in cardiovascular diseases (CVD) and diabetes mellitus (DM). The overall aims of the BMIW Group's programme within CANNeCTIN, are to advance biostatistical and methodological research, and to build biostatistical capacity in CVD and DM. Our program of research and training includes: monthly videoconferences on topical biostatistical and methodological issues in CVD/DM clinical studies; providing presentations on methods issues at the annual CANNeCTIN meetings; collaborating with clinician investigators on their studies; training young statisticians in biostatistics and methods in CVD/DM trials and organizing annual symposiums on topical methodological issues. We are focused on the development of new biostatistical methods and the recruitment and training of highly qualified personnel - who will become leaders in the design and analysis of CVD/DM trials. The ultimate goal is to enhance global health by contributing to efforts to reduce the burden of CVD and DM. PMID:21332987

Rheumatologist and Primary Care Management of Cardiovascular Disease Risk in Rheumatoid Arthritis: Patient and Provider Perspectives.

PubMed

Bartels, Christie M; Roberts, Tonya J; Hansen, Karen E; Jacobs, Elizabeth A; Gilmore, Andrea; Maxcy, Courtney; Bowers, Barbara J

2016-04-01

Despite increased cardiovascular disease (CVD) risk, rheumatoid arthritis (RA) patients often lack CVD preventive care. We examined CVD preventive care processes from RA patient and provider perspectives to develop a process map for identifying targets for future interventions to improve CVD preventive care. Thirty-one participants (15 patients, 7 rheumatologists, and 9 primary care physicians [PCPs]) participated in interviews that were coded using NVivo software and analyzed using grounded theory techniques. Patients and providers reported that receipt of preventive care depends upon identifying and acting on risk factors, although most noted that both processes rarely occurred. Engagement in these processes was influenced by various provider-, system-, visit-, and patient-related conditions, such as patient activation or patients' knowledge about their risk. While nearly half of patients and PCPs were unaware of RA-CVD risk, all rheumatologists were aware of risk. Rheumatologists reported not systematically identifying risk factors, or, if identified, they described communicating about CVD risk factors via clinic notes to PCPs instead of acting directly due to perceived role boundaries. PCPs suggested that scheduling PCP visits could improve CVD risk management, and all participants viewed comanagement positively. Findings from this study illustrate important gaps and opportunities to support identifying and acting on CVD risk factors in RA patients from the provider, system, visit, and patient levels. Future work should investigate professional role support through improved guidelines, patient activation, and system-based RA-CVD preventive care strategies. © 2016, American College of Rheumatology.

Exposure to Experimental Preeclampsia in Mice Enhances the Vascular Response to Future Injury

PubMed Central

Pruthi, Dafina; Khankin, Eliyahu V.; Blanton, Robert M.; Aronovitz, Mark; Burke, Suzanne D.; McCurley, Amy; Karumanchi, S. Ananth; Jaffe, Iris Z.

2015-01-01

Cardiovascular disease (CVD) remains the leading killer of women in developed nations. One gender-specific risk factor is preeclampsia (PE), a syndrome of hypertension and proteinuria that complicates 5% of pregnancies. Although PE resolves after delivery, exposed women are at increased long term risk of premature CVD and mortality. Preexisting CVD risk factors are associated with increased risk of developing PE but whether PE merely uncovers risk or contributes directly to future CVD remains a critical unanswered question. A mouse PE model was used to test the hypothesis that PE causes an enhanced vascular response to future vessel injury. A PE-like state was induced in pregnant CD1 mice by overexpressing soluble fms-like tyrosine kinase-1 (sFlt-1), a circulating anti-angiogenic protein that induces hypertension and glomerular disease resembling human PE. Two months post-partum, sFlt-1 levels and blood pressure normalized and cardiac size and function by echocardiography and renal histology were indistinguishable in PE-exposed compared to control mice. Mice were then challenged with unilateral carotid injury. PE-exposed mice had significantly enhanced vascular remodeling with increased vascular smooth muscle cell proliferation (180% increase, P<0.01) and vessel fibrosis (216% increase, P<0.001) compared to control pregnancy. In the contralateral uninjured vessel, there was no difference in remodeling after exposure to PE. These data support a new model in which vessels exposed to PE retain a persistently enhanced vascular response to injury despite resolution of PE after delivery. This new paradigm may contribute to the substantially increased risk of CVD in woman exposed to PE. PMID:25712723

Reduced graphene oxide nanoshells for flexible and stretchable conductors

NASA Astrophysics Data System (ADS)

Jiang, Wen-Shuai; Liu, Zhi-Bo; Xin, Wei; Chen, Xu-Dong; Tian, Jian-Guo

2016-03-01

Graphene has been extensively investigated for its use in flexible electronics, especially graphene synthesized by chemical vapor deposition (CVD). To enhance the flexibility of CVD graphene, wrinkles are often introduced. However, reports on the flexibility of reduced graphene oxide (RGO) films are few, because of their weak conductivity and, in particular, poor flexibility. To improve the flexibility of RGO, reduced graphene oxide nanoshells are fabricated, which combine self-assembled polystyrene nanosphere arrays and high-temperature thermal annealing processes. The resulting RGO films with nanoshells present a better resistance stabilization after stretching and bending the devices than RGO without nanoshells. The sustainability and performance advances demonstrated here are promising for the adoption of flexible electronics in a wide variety of future applications.

PATHway: Decision Support in Exercise Programmes for Cardiac Rehabilitation.

PubMed

Filos, Dimitris; Triantafyllidis, Andreas; Chouvarda, Ioanna; Buys, Roselien; Cornelissen, Véronique; Budts, Werner; Walsh, Deirdre; Woods, Catherine; Moran, Kieran; Maglaveras, Nicos

2016-01-01

Rehabilitation is important for patients with cardiovascular diseases (CVD) to improve health outcomes and quality of life. However, adherence to current exercise programmes in cardiac rehabilitation is limited. We present the design and development of a Decision Support System (DSS) for telerehabilitation, aiming to enhance exercise programmes for CVD patients through ensuring their safety, personalising the programme according to their needs and performance, and motivating them toward meeting their physical activity goals. The DSS processes data originated from a Microsoft Kinect camera, a blood pressure monitor, a heart rate sensor and questionnaires, in order to generate a highly individualised exercise programme and improve patient adherence. Initial results within the EU-funded PATHway project show the potential of our approach.

Plasma Enhanced Growth of Carbon Nanotubes For Ultrasensitive Biosensors

NASA Technical Reports Server (NTRS)

Cassell, Alan M.; Meyyappan, M.

2004-01-01

The multitude of considerations facing nanostructure growth and integration lends itself to combinatorial optimization approaches. Rapid optimization becomes even more important with wafer-scale growth and integration processes. Here we discuss methodology for developing plasma enhanced CVD growth techniques for achieving individual, vertically aligned carbon nanostructures that show excellent properties as ultrasensitive electrodes for nucleic acid detection. We utilize high throughput strategies for optimizing the upstream and downstream processing and integration of carbon nanotube electrodes as functional elements in various device types. An overview of ultrasensitive carbon nanotube based sensor arrays for electrochemical bio-sensing applications and the high throughput methodology utilized to combine novel electrode technology with conventional MEMS processing will be presented.

Plasma Enhanced Growth of Carbon Nanotubes For Ultrasensitive Biosensors

NASA Technical Reports Server (NTRS)

Cassell, Alan M.; Li, J.; Ye, Q.; Koehne, J.; Chen, H.; Meyyappan, M.

2004-01-01

The multitude of considerations facing nanostructure growth and integration lends itself to combinatorial optimization approaches. Rapid optimization becomes even more important with wafer-scale growth and integration processes. Here we discuss methodology for developing plasma enhanced CVD growth techniques for achieving individual, vertically aligned carbon nanostructures that show excellent properties as ultrasensitive electrodes for nucleic acid detection. We utilize high throughput strategies for optimizing the upstream and downstream processing and integration of carbon nanotube electrodes as functional elements in various device types. An overview of ultrasensitive carbon nanotube based sensor arrays for electrochemical biosensing applications and the high throughput methodology utilized to combine novel electrode technology with conventional MEMS processing will be presented.

Community cardiovascular disease risk from cross-sectional general practice clinical data: a spatial analysis.

PubMed

Bagheri, Nasser; Gilmour, Bridget; McRae, Ian; Konings, Paul; Dawda, Paresh; Del Fante, Peter; van Weel, Chris

2015-02-26

Cardiovascular disease (CVD) continues to be a leading cause of illness and death among adults worldwide. The objective of this study was to calculate a CVD risk score from general practice (GP) clinical records and assess spatial variations of CVD risk in communities. We used GP clinical data for 4,740 men and women aged 30 to 74 years with no history of CVD. A 10-year absolute CVD risk score was calculated based on the Framingham risk equation. The individual risk scores were aggregated within each Statistical Area Level One (SA1) to predict the level of CVD risk in that area. Finally, the pattern of CVD risk was visualized to highlight communities with high and low risk of CVD. The overall 10-year risk of CVD in our sample population was 14.6% (95% confidence interval [CI], 14.3%-14.9%). Of the 4,740 patients in our study, 26.7% were at high risk, 29.8% were at moderate risk, and 43.5% were at low risk for CVD over 10 years. The proportion of patients at high risk for CVD was significantly higher in the communities of low socioeconomic status. This study illustrates methods to further explore prevalence, location, and correlates of CVD to identify communities of high levels of unmet need for cardiovascular care and to enable geographic targeting of effective interventions for enhancing early and timely detection and management of CVD in those communities.

Chemical vapor deposition growth

NASA Technical Reports Server (NTRS)

Ruth, R. P.; Manasevit, H. M.; Campbell, A. G.; Johnson, R. E.; Kenty, J. L.; Moudy, L. A.; Shaw, G. L.; Simpson, W. I.; Yang, J. J.

1978-01-01

The objective was to investigate and develop chemical vapor deposition (CVD) techniques for the growth of large areas of Si sheet on inexpensive substrate materials, with resulting sheet properties suitable for fabricating solar cells that would meet the technical goals of the Low Cost Silicon Solar Array Project. The program involved six main technical tasks: (1) modification and test of an existing vertical-chamber CVD reactor system; (2) identification and/or development of suitable inexpensive substrate materials; (3) experimental investigation of CVD process parameters using various candidate substrate materials; (4) preparation of Si sheet samples for various special studies, including solar cell fabrication; (5) evaluation of the properties of the Si sheet material produced by the CVD process; and (6) fabrication and evaluation of experimental solar cell structures, using impurity diffusion and other standard and near-standard processing techniques supplemented late in the program by the in situ CVD growth of n(+)/p/p(+) sheet structures subsequently processed into experimental cells.

Chemical vapor deposition growth

NASA Technical Reports Server (NTRS)

Ruth, R. P.; Manasevit, H. M.; Kenty, J. L.; Moudy, L. A.; Simpson, W. I.; Yang, J. J.

1976-01-01

The chemical vapor deposition (CVD) method for the growth of Si sheet on inexpensive substrate materials is investigated. The objective is to develop CVD techniques for producing large areas of Si sheet on inexpensive substrate materials, with sheet properties suitable for fabricating solar cells meeting the technical goals of the Low Cost Silicon Solar Array Project. Specific areas covered include: (1) modification and test of existing CVD reactor system; (2) identification and/or development of suitable inexpensive substrate materials; (3) experimental investigation of CVD process parameters using various candidate substrate materials; (4) preparation of Si sheet samples for various special studies, including solar cell fabrication; (5) evaluation of the properties of the Si sheet material produced by the CVD process; and (6) fabrication and evaluation of experimental solar cell structures, using standard and near-standard processing techniques.

Chemical vapor deposition modeling for high temperature materials

NASA Technical Reports Server (NTRS)

Gokoglu, Suleyman A.

1992-01-01

The formalism for the accurate modeling of chemical vapor deposition (CVD) processes has matured based on the well established principles of transport phenomena and chemical kinetics in the gas phase and on surfaces. The utility and limitations of such models are discussed in practical applications for high temperature structural materials. Attention is drawn to the complexities and uncertainties in chemical kinetics. Traditional approaches based on only equilibrium thermochemistry and/or transport phenomena are defended as useful tools, within their validity, for engineering purposes. The role of modeling is discussed within the context of establishing the link between CVD process parameters and material microstructures/properties. It is argued that CVD modeling is an essential part of designing CVD equipment and controlling/optimizing CVD processes for the production and/or coating of high performance structural materials.

Surface structuring of boron doped CVD diamond by micro electrical discharge machining

NASA Astrophysics Data System (ADS)

Schubert, A.; Berger, T.; Martin, A.; Hackert-Oschätzchen, M.; Treffkorn, N.; Kühn, R.

2018-05-01

Boron doped diamond materials, which are generated by Chemical Vapor Deposition (CVD), offer a great potential for the application on highly stressed tools, e. g. in cutting or forming processes. As a result of the CVD process rough surfaces arise, which require a finishing treatment in particular for the application in forming tools. Cutting techniques such as milling and grinding are hardly applicable for the finish machining because of the high strength of diamond. Due to its process principle of ablating material by melting and evaporating, Electrical Discharge Machining (EDM) is independent of hardness, brittleness or toughness of the workpiece material. EDM is a suitable technology for machining and structuring CVD diamond, since boron doped CVD diamond is electrically conductive. In this study the ablation characteristics of boron doped CVD diamond by micro electrical discharge machining are investigated. Experiments were carried out to investigate the influence of different process parameters on the machining result. The impact of tool-polarity, voltage and discharge energy on the resulting erosion geometry and the tool wear was analyzed. A variation in path overlapping during the erosion of planar areas leads to different microstructures. The results show that micro EDM is a suitable technology for finishing of boron doped CVD diamond.

Follow YOUR Heart: development of an evidence-based campaign empowering older women with HIV to participate in a large-scale cardiovascular disease prevention trial.

PubMed

Zanni, Markella V; Fitch, Kathleen; Rivard, Corinne; Sanchez, Laura; Douglas, Pamela S; Grinspoon, Steven; Smeaton, Laura; Currier, Judith S; Looby, Sara E

2017-03-01

Women's under-representation in HIV and cardiovascular disease (CVD) research suggests a need for novel strategies to ensure robust representation of women in HIV-associated CVD research. To elicit perspectives on CVD research participation among a community-sample of women with or at risk for HIV, and to apply acquired insights toward the development of an evidence-based campaign empowering older women with HIV to participate in a large-scale CVD prevention trial. In a community-based setting, we surveyed 40 women with or at risk for HIV about factors which might facilitate or impede engagement in CVD research. We applied insights derived from these surveys into the development of the Follow YOUR Heart campaign, educating women about HIV-associated CVD and empowering them to learn more about a multi-site HIV-associated CVD prevention trial: REPRIEVE. Endorsed best methods for learning about a CVD research study included peer-to-peer communication (54%), provider communication (46%) and video-based communication (39%). Top endorsed non-monetary reasons for participating in research related to gaining information (63%) and helping others (47%). Top endorsed reasons for not participating related to lack of knowledge about studies (29%) and lack of request to participate (29%). Based on survey results, the REPRIEVE Follow YOUR Heart campaign was developed. Interwoven campaign components (print materials, video, web presence) offer provider-based information/knowledge, peer-to-peer communication, and empowerment to learn more. Campaign components reflect women's self-identified motivations for research participation - education and altruism. Investigation of factors influencing women's participation in HIV-associated CVD research may be usefully applied to develop evidence-based strategies for enhancing women's enrollment in disease-specific large-scale trials. If proven efficacious, such strategies may enhance conduct of large-scale research studies across disciplines.

Exposure to experimental preeclampsia in mice enhances the vascular response to future injury.

PubMed

Pruthi, Dafina; Khankin, Eliyahu V; Blanton, Robert M; Aronovitz, Mark; Burke, Suzanne D; McCurley, Amy; Karumanchi, S Ananth; Jaffe, Iris Z

2015-04-01

Cardiovascular disease (CVD) remains the leading killer of women in developed nations. One sex-specific risk factor is preeclampsia, a syndrome of hypertension and proteinuria that complicates 5% of pregnancies. Although preeclampsia resolves after delivery, exposed women are at increased long-term risk of premature CVD and mortality. Pre-existing CVD risk factors are associated with increased risk of developing preeclampsia but whether preeclampsia merely uncovers risk or contributes directly to future CVD remains a critical unanswered question. A mouse preeclampsia model was used to test the hypothesis that preeclampsia causes an enhanced vascular response to future vessel injury. A preeclampsia-like state was induced in pregnant CD1 mice by overexpressing soluble fms-like tyrosine kinase-1, a circulating antiangiogenic protein that induces hypertension and glomerular disease resembling human preeclampsia. Two months postpartum, soluble fms-like tyrosine kinase-1 levels and blood pressure normalized and cardiac size and function by echocardiography and renal histology were indistinguishable in preeclampsia-exposed compared with control mice. Mice were then challenged with unilateral carotid injury. Preeclampsia-exposed mice had significantly enhanced vascular remodeling with increased vascular smooth muscle cell proliferation (180% increase; P<0.01) and vessel fibrosis (216% increase; P<0.001) compared with control pregnancy. In the contralateral uninjured vessel, there was no difference in remodeling after exposure to preeclampsia. These data support a new model in which vessels exposed to preeclampsia retain a persistently enhanced vascular response to injury despite resolution of preeclampsia after delivery. This new paradigm may contribute to the substantially increased risk of CVD in woman exposed to preeclampsia. © 2015 American Heart Association, Inc.

Orientation effect in d(d,n)3He reaction initiated by 20 keV deuterons at channeling in textured CVD-Diamond target

NASA Astrophysics Data System (ADS)

Bagulya, A. V.; Dalkarov, O. D.; Negodaev, M. A.; Pivovarov, Yu. L.; Rusetskii, A. S.; Tukhfatullin, T. A.

2017-07-01

Orientation effect of increasing the enhancement factor of DD-reaction in CVD-Diamond was investigated by simulation. It is obtained that the flux peaking effect up to 2.2 times increases the relative enhancement factor for a parallel beam and up to 1.2 times for the deuteron beam with angular divergence equals 3 critical channeling angles. Qualitative agreement with the experiment was obtained.

Advanced methods for processing ceramics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carter, W.B.

1997-04-01

Combustion chemical vapor deposition (combustion CVD) is being developed for the deposition of high temperature oxide coatings. The process is being evaluated as an alternative to more capital intensive conventional coating processes. The thrusts during this reporting period were the development of the combustion CVD process for depositing lanthanum monazite, the determination of the influence of aerosol size on coating morphology, the incorporation of combustion CVD coatings into thermal barrier coatings (TBCs) and related oxidation research, and continued work on the deposition of zirconia-yttria coatings.

Automatic chemical vapor deposition

NASA Technical Reports Server (NTRS)

Kennedy, B. W.

1981-01-01

Report reviews chemical vapor deposition (CVD) for processing integrated circuits and describes fully automatic machine for CVD. CVD proceeds at relatively low temperature, allows wide choice of film compositions (including graded or abruptly changing compositions), and deposits uniform films of controllable thickness at fairly high growth rate. Report gives overview of hardware, reactants, and temperature ranges used with CVD machine.

The CRDS method application for study of the gas-phase processes in the hot CVD diamond thin film.

NASA Astrophysics Data System (ADS)

Buzaianumakarov, Vladimir; Hidalgo, Arturo; Morell, Gerardo; Weiner, Brad; Buzaianu, Madalina

2006-03-01

For detailed analysis of problem related to the hot CVD carbon-containing nano-material growing, we have to detect different intermediate species forming during the growing process as well as investigate dependences of concentrations of these species on different experimental parameters (concentrations of the CJH4, H2S stable chemical compounds and distance from the filament system to the substrate surface). In the present study, the HS and CS radicals were detected using the Cavity Ring Down Spectroscopic (CRDS) method in the hot CVD diamond thin film for the CH4(0.4 %) + H2 mixture doped by H2S (400 ppm). The absolute absorption density spectra of the HS and CS radicals were obtained as a function of different experimental parameters. This study proofs that the HS and CS radicals are an intermediate, which forms during the hot filament CVD process. The kinetics approach was developed for detailed analysis of the experimental data obtained. The kinetics scheme includes homogenous and heterogenous processes as well as processes of the chemical species transport in the CVD chamber.

Effect of process conditions and chemical composition on the microstructure and properties of chemically vapor deposited SiC, Si, ZnSe, ZnS and ZnS(x)Se(1-x)

NASA Technical Reports Server (NTRS)

Pickering, Michael A.; Taylor, Raymond L.; Goela, Jitendra S.; Desai, Hemant D.

1992-01-01

Subatmospheric pressure CVD processes have been developed to produce theoretically dense, highly pure, void-free and large area bulk materials, SiC, Si, ZnSe, ZnS and ZnS(x)Se(1-x). These materials are used for optical elements, such as mirrors, lenses and windows, over a wide spectral range from the VUV to the IR. We discuss the effect of CVD process conditions on the microstructure and properties of these materials, with emphasis on optical performance. In addition, we discuss the effect of chemical composition on the properties of the composite material ZnS(x)Se(1-x). We first present a general overview of the bulk CVD process and the relationship between process conditions, such as temperature, pressure, reactant gas concentration and growth rate, and the microstructure, morphology and properties of CVD-grown materials. Then we discuss specific results for CVD-grown SiC, Si, ZnSe, ZnS and ZnS(x)Se(1-x).

Decision-making in an era of cancer prevention via aspirin: New Zealand needs updated guidelines and risk calculators.

PubMed

Wilson, Nick; Selak, Vanessa; Blakely, Tony; Leung, William; Clarke, Philip; Jackson, Rod; Knight, Josh; Nghiem, Nhung

2016-03-11

Based on new systematic reviews of the evidence, the US Preventive Services Task Force has drafted updated guidelines on the use of low-dose aspirin for the primary prevention of both cardiovascular disease (CVD) and cancer. The Task Force generally recommends consideration of aspirin in adults aged 50-69 years with 10-year CVD risk of at least 10%, in who absolute health gain (reduction of CVD and cancer) is estimated to exceed absolute health loss (increase in bleeds). With the ongoing decline in CVD, current risk calculators for New Zealand are probably outdated, so it is difficult to be precise about what proportion of the population is in this risk category (roughly equivalent to 5-year CVD risk ≥5%). Nevertheless, we suspect that most smokers aged 50-69 years, and some non-smokers, would probably meet the new threshold for taking low-dose aspirin. The country therefore needs updated guidelines and risk calculators that are ideally informed by estimates of absolute net health gain (in quality-adjusted life-years (QALYs) per person) and cost-effectiveness. Other improvements to risk calculators include: epidemiological rigour (eg, by addressing competing mortality); providing enhanced graphical display of risk to enhance risk communication; and possibly capturing the issues of medication disutility and comparison with lifestyle changes.

Heparin free coating on PLA membranes for enhanced hemocompatibility via iCVD

NASA Astrophysics Data System (ADS)

Wang, Hui; Shi, Xiao; Gao, Ailin; Lin, Haibo; Chen, Yongliang; Ye, Yumin; He, Jidong; Liu, Fu; Deng, Gang

2018-03-01

In the present work, we report one-step immobilization of nano-heparin coating on PLA membranes via initiated chemical vapor deposition (iCVD) for enhanced hemocompatibility. The nano-coating introduced onto the membrane surface via the crosslinking of P(MAA-EGDA) was confirmed by the FTIR, SEM and weight measurement respectively. The negative carboxyl groups could form the hydration interaction with the protein and platelets and electrostatic interaction with amide groups of thrombin by the mediation of antithrombin, which is similar but different with heparin. The P(MAA-EGDA) coated membranes showed suppressed platelet adhesion and prolonged clotting time (APTTs increased to 59 s, PTs increased to 20.4 s, TTs increased to 17.5 s, and the FIBs declined by 30 mg/dL). Moreover, the complement activation tests demonstrated the formation of C3a and C5a was inhibited. All results demonstrated that the nano-coating of P(MAA-EGDA) via iCVD significantly enhanced the hemocompatibility of PLA membranes, which is also applicable for various membranes.

Improving compliance in remote healthcare systems through smartphone battery optimization.

PubMed

Alshurafa, Nabil; Eastwood, Jo-Ann; Nyamathi, Suneil; Liu, Jason J; Xu, Wenyao; Ghasemzadeh, Hassan; Pourhomayoun, Mohammad; Sarrafzadeh, Majid

2015-01-01

Remote health monitoring (RHM) has emerged as a solution to help reduce the cost burden of unhealthy lifestyles and aging populations. Enhancing compliance to prescribed medical regimens is an essential challenge to many systems, even those using smartphone technology. In this paper, we provide a technique to improve smartphone battery consumption and examine the effects of smartphone battery lifetime on compliance, in an attempt to enhance users' adherence to remote monitoring systems. We deploy WANDA-CVD, an RHM system for patients at risk of cardiovascular disease (CVD), using a wearable smartphone for detection of physical activity. We tested the battery optimization technique in an in-lab pilot study and validated its effects on compliance in the Women's Heart Health Study. The battery optimization technique enhanced the battery lifetime by 192% on average, resulting in a 53% increase in compliance in the study. A system like WANDA-CVD can help increase smartphone battery lifetime for RHM systems monitoring physical activity.

Zinc Oxide Grown by CVD Process as Transparent Contact for Thin Film Solar Cell Applications

NASA Astrophysics Data System (ADS)

Faÿ, S.; Shah, A.

Metalorganic chemical vapor deposition of ZnO films (MOCVD) [1] started to be comprehensively investigated in the 1980s, when thin film industries were looking for ZnO deposition processes especially useful for large-scale coatings at high growth rates. Later on, when TCO for thin film solar cells started to be developed, another advantage of growing TCO films by the CVD process has been highlighted: the surface roughness. Indeed, a large number of studies on CVD ZnO revealed that an as-grown rough surface cn be obtained with this deposition process [2-4]. A rough surface induces a light scattering effect, which can significantly improve light trapping (and therefore current photo-generation) within thin film silicon solar cells. The CVD process, indeed, directly leads to as-grown rough ZnO films without any post-etching step (the latter is often introduced to obtain a rough surface, when working with as-deposited flat sputtered ZnO). This fact could turn out to be a significant advantage when upscaling the manufacturing process for actual commercial production of thin film solar modules. The zinc and oxygen sources for CVD growth of ZnO films are given in Table 6.1.

Nanoscale plasma chemistry enables fast, size-selective nanotube nucleation.

PubMed

Ostrikov, Kostya Ken; Mehdipour, Hamid

2012-03-07

The possibility of fast, narrow-size/chirality nucleation of thin single-walled carbon nanotubes (SWCNTs) at low, device-tolerant process temperatures in a plasma-enhanced chemical vapor deposition (CVD) is demonstrated using multiphase, multiscale numerical experiments. These effects are due to the unique nanoscale reactive plasma chemistry (NRPC) on the surfaces and within Au catalyst nanoparticles. The computed three-dimensional process parameter maps link the nanotube incubation times and the relative differences between the incubation times of SWCNTs of different sizes/chiralities to the main plasma- and precursor gas-specific parameters and explain recent experimental observations. It is shown that the unique NRPC leads not only to much faster nucleation of thin nanotubes at much lower process temperatures, but also to better selectivity between the incubation times of SWCNTs with different sizes and chiralities, compared to thermal CVD. These results are used to propose a time-programmed kinetic approach based on fast-responding plasmas which control the size-selective, narrow-chirality nucleation and growth of thin SWCNTs. This approach is generic and can be used for other nanostructure and materials systems. © 2012 American Chemical Society

Plasma boriding of a cobalt-chromium alloy as an interlayer for nanostructured diamond growth

NASA Astrophysics Data System (ADS)

Johnston, Jamin M.; Jubinsky, Matthew; Catledge, Shane A.

2015-02-01

Chemical vapor deposited (CVD) diamond coatings can potentially improve the wear resistance of cobalt-chromium medical implant surfaces, but the high cobalt content in these alloys acts as a catalyst to form graphitic carbon. Boriding by high temperature liquid baths and powder packing has been shown to improve CVD diamond compatibility with cobalt alloys. We use the microwave plasma-enhanced (PE) CVD process to deposit interlayers composed primarily of the borides of cobalt and chromium. The use of diborane (B2H6) in the plasma feedgas allows for the formation of a robust boride interlayer for suppressing graphitic carbon during subsequent CVD of nano-structured diamond (NSD). This metal-boride interlayer is shown to be an effective diffusion barrier against elemental cobalt for improving nucleation and adhesion of NSD coatings on a CoCrMo alloy. Migration of elemental cobalt to the surface of the interlayer is significantly reduced and undetectable on the surface of the subsequently-grown NSD coating. The effects of PECVD boriding are compared for a range of substrate temperatures and deposition times and are evaluated using glancing-angle X-ray diffraction (XRD), cross-sectional scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and micro-Raman spectroscopy. Boriding of CoCrMo results in adhered nanostructured diamond coatings with low surface roughness.

Development of CVD Diamond for Industrial Applications Final Report CRADA No. TC-2047-02

DOE Office of Scientific and Technical Information (OSTI.GOV)

Caplan, M.; Olstad, R.; Jory, H.

2017-09-08

This project was a collaborative effort to develop and demonstrate a new millimeter microwave assisted chemical vapor deposition(CVD) process for manufacturing large diamond disks with greatly reduced processing times and costs from those now available. In the CVD process, carbon based gases (methane) and hydrogen are dissociated into plasma using microwave discharge and then deposited layer by layer as polycrystalline diamond onto a substrate. The available low frequency (2.45GHz) microwave sources used elsewhere (De Beers) result in low density plasmas and low deposition rates: 4 inch diamond disks take 6-8 weeks to process. The new system developed in this projectmore » uses a high frequency 30GHz Gyrotron as the microwave source and a quasi-optical CVD chamber resulting in a much higher density plasma which greatly reduced the diamond processing times (1-2 weeks)« less

Synthesis of SiV-diamond particulates via the microwave plasma chemical deposition of ultrananocrystalline diamond on soda-lime glass fibers

NASA Astrophysics Data System (ADS)

Kunuku, Srinivasu; Chen, Yen-Chun; Yeh, Chien-Jui; Chang, Wen-Hao; Manoharan, Divinah; Leou, Keh-Chyang; Lin, I.-Nan

2016-10-01

We report the synthesis of silicon-vacancy (SiV) incorporated spherical shaped ultrananocrystalline diamond (SiV-UNCD) particulates (size ∼1 μm) with bright luminescence at 738 nm. For this purpose, different granular structured polycrystalline diamond films and particulates were synthesized by using three different kinds of growth plasma conditions on the three types of substrate materials in the microwave plasma enhanced CVD process. The grain size dependent photoluminescence properties of nitrogen vacancy (NV) and SiV color centers have been investigated for different granular structured diamond samples. The luminescence of NV center and the associated phonon sidebands, which are usually observed in microcrystalline diamond and nanocrystalline diamond films, were effectively suppressed in UNCD films and UNCD particulates. Micron sized SiV-UNCD particulates with bright SiV emission has been attained by transfer of SiV-UNCD clusters on soda-lime glass fibers to inverted pyramidal cavities fabricated on Si substrates by the simple crushing of UNCD/soda-lime glass fibers in deionized water and ultrasonication. Such a plasma enhanced CVD process for synthesizing SiV-UNCD particulates with suppressed NV emission is simple and robust to attain the bright SiV-UNCD particulates to employ in practical applications.

Development and optimization of carvedilol orodispersible tablets: enhancement of pharmacokinetic parameters in rabbits

PubMed Central

Aljimaee, Yazeed HM; El-Helw, Abdel-Rahim M; Ahmed, Osama AA; El-Say, Khalid M

2015-01-01

Background Carvedilol (CVD) is used for the treatment of essential hypertension, heart failure, and systolic dysfunction after myocardial infarction. Due to its lower aqueous solubility and extensive first-pass metabolism, the absolute bioavailability of CVD does not exceed 30%. To overcome these drawbacks, the objective of this work was to improve the solubility and onset of action of CVD through complexation with hydroxypropyl-β-cyclodextrin and formulation of the prepared complex as orodispersible tablets (ODTs). Methods Compatibility among CVD and all tablet excipients using differential scanning calorimetry and Fourier transform infrared spectroscopy, complexation of CVD with different polymers, and determination of the solubility of CVD in the prepared complexes were first determined. A Box-Behnken design (BBD) was used to study the effect of tablet formulation variables on the characteristics of the prepared tablets and to optimize preparation conditions. According to BBD design, 15 formulations of CVD-ODTs were prepared by direct compression and then evaluated for their quality attributes. The relative pharmacokinetic parameters of the optimized CVD-ODTs were compared with those of the marketed CVD tablet. A single dose, equivalent to 2.5 mg/kg CVD, was administered orally to New Zealand white rabbits using a double-blind, randomized, crossover design. Results The solubility of CVD was improved from 7.32 to 22.92 mg/mL after complexation with hydroxypropyl-β-cyclodextrin at a molar ratio of 1:2 (CVD to cyclodextrin). The formulated CVD-ODTs showed satisfactory results concerning tablet hardness (5.35 kg/cm2), disintegration time (18 seconds), and maximum amount of CVD released (99.72%). The pharmacokinetic data for the optimized CVD-ODT showed a significant (P<0.05) increase in maximum plasma concentration from 363.667 to 496.4 ng/mL, and a shortening of the time taken to reach maximum plasma concentration to 2 hours in comparison with the marketed tablet. Conclusion The optimized CVD-ODTs showed improved oral absorption of CVD and a subsequent acceleration of clinical effect, which is favored for hypertensive and cardiac patients. PMID:25834396

Impact of growth rate on graphene lattice-defect formation within a single crystalline domain.

PubMed

Chin, Hao-Ting; Lee, Jian-Jhang; Hofmann, Mario; Hsieh, Ya-Ping

2018-03-06

Chemical vapor deposition (CVD) is promising for the large scale production of graphene and other two-dimensional materials. Optimization of the CVD process for enhancing their quality is a focus of ongoing effort and significant progress has been made in decreasing the defectiveness associated with grain boundaries and nucleation spots. However, little is known about the quality and origin of structural defects in the outgrowing lattice which are present even in single-crystalline material and represent the limit of current optimization efforts. We here investigate the formation kinetics of such defects by controlling graphene's growth rate over a wide range using nanoscale confinements. Statistical analysis of Raman spectroscopic results shows a clear trend between growth rate and defectiveness that is in quantitative agreement with a model where defects are healed preferentially at the growth front. Our results suggest that low growth rates are required to avoid the freezing of lattice defects and form high quality material. This conclusion is confirmed by a fourfold enhancement in graphene's carrier mobility upon optimization of the growth rate.

Rate equation analysis of hydrogen uptake on Si (100) surfaces

DOE Office of Scientific and Technical Information (OSTI.GOV)

Inanaga, S.; Rahman, F.; Khanom, F.

2005-09-15

We have studied the uptake process of H on Si (100) surfaces by means of rate equation analysis. Flowers' quasiequilibrium model for adsorption and desorption of H [M. C. Flowers, N. B. H. Jonathan, A. Morris, and S. Wright, Surf. Sci. 396, 227 (1998)] is extended so that in addition to the H abstraction (ABS) and {beta}{sub 2}-channel thermal desorption (TD) the proposed rate equation further includes the adsorption-induced desorption (AID) and {beta}{sub 1}-TD. The validity of the model is tested by the experiments of ABS and AID rates in the reaction system H+D/Si (100). Consequently, we find it canmore » well reproduce the experimental results, validating the proposed model. We find the AID rate curve as a function of surface temperature T{sub s} exhibits a clear anti-correlation with the bulk dangling bond density versus T{sub s} curve reported in the plasma-enhanced chemical vapor deposition (CVD) for amorphous Si films. The significance of the H chemistry in plasma-enhanced CVD is discussed.« less

Controlling cardiovascular diseases in low and middle income countries by placing proof in pragmatism

PubMed Central

Owolabi, Mayowa; Miranda, Jaime J; Yaria, Joseph; Ovbiagele, Bruce

2016-01-01

Low and middle income countries (LMICs) bear a huge, disproportionate and growing burden of cardiovascular disease (CVD) which constitutes a threat to development. Efforts to tackle the global burden of CVD must therefore emphasise effective control in LMICs by addressing the challenge of scarce resources and lack of pragmatic guidelines for CVD prevention, treatment and rehabilitation. To address these gaps, in this analysis article, we present an implementation cycle for developing, contextualising, communicating and evaluating CVD recommendations for LMICs. This includes a translatability scale to rank the potential ease of implementing recommendations, prescriptions for engaging stakeholders in implementing the recommendations (stakeholders such as providers and physicians, patients and the populace, policymakers and payers) and strategies for enhancing feedback. This approach can help LMICs combat CVD despite limited resources, and can stimulate new implementation science hypotheses, research, evidence and impact. PMID:27840737

Cardiovascular disease prevention and health promotion with the transcendental meditation program and Maharishi consciousness-based health care.

PubMed

Schneider, Robert H; Walton, Kenneth G; Salerno, John W; Nidich, Sanford I

2006-01-01

This article summarizes the background, rationale, and clinical research on a traditional system of natural health care that may be useful in the prevention of cardiovascular disease (CVD) and promotion of health. Results recently reported include reductions in blood pressure, psychosocial stress, surrogate markers for atherosclerotic CVD, and mortality. The randomized clinical trials conducted so far have involved applications to both primary and secondary prevention as well as to health promotion more generally. The results support the applicability of this approach for reducing ethnic health disparities associated with environmental and psychosocial stress. Proposed mechanisms for the effects of this traditional system include enhanced resistance to physiological and psychological stress and improvements in homeostatic and self-repair processes. This system may offer clinical and cost effectiveness advantages for health care, particularly in preventive cardiology.

Controlled growth of CNT in mesoporous AAO through optimized conditions for membrane preparation and CVD operation

NASA Astrophysics Data System (ADS)

Ciambelli, P.; Arurault, L.; Sarno, M.; Fontorbes, S.; Leone, C.; Datas, L.; Sannino, D.; Lenormand, P.; Le Blond Du Plouy, S.

2011-07-01

Anodic aluminium oxide (RAAO) membranes with a mesoporous structure were prepared under strictly controlling experimental process conditions, and physically and chemically characterized by a wide range of experimental techniques. Commercial anodic aluminium oxide (CAAO) membranes were also investigated for comparison. We demonstrated that RAAO membranes have lower content of both water and phosphorus and showed better porosity shape than CAAO. The RAAO membranes were used for template growth of carbon nanotubes (CNT) inside its pores by ethylene chemical vapour deposition (CVD) in the absence of a catalyst. A composite material, containing one nanotube for each channel, having the same length as the membrane thickness and an external diameter close to the diameter of the membrane holes, was obtained. Yield, selectivity and quality of CNTs in terms of diameter, length and arrangement (i.e. number of tubes for each channel) were optimized by investigating the effect of changing the experimental conditions for the CVD process. We showed that upon thermal treatment RAAO membranes were made up of crystallized allotropic alumina phases, which govern the subsequent CNT growth, because of their catalytic activity, likely due to their Lewis acidity. The strict control of experimental conditions for membrane preparation and CNT growth allowed us to enhance the carbon structural order, which is a critical requisite for CNT application as a substitute for copper in novel nano-interconnects.

Controlled growth of CNT in mesoporous AAO through optimized conditions for membrane preparation and CVD operation.

PubMed

Ciambelli, P; Arurault, L; Sarno, M; Fontorbes, S; Leone, C; Datas, L; Sannino, D; Lenormand, P; Du Plouy, S Le Blond

2011-07-01

Anodic aluminium oxide (RAAO) membranes with a mesoporous structure were prepared under strictly controlling experimental process conditions, and physically and chemically characterized by a wide range of experimental techniques. Commercial anodic aluminium oxide (CAAO) membranes were also investigated for comparison. We demonstrated that RAAO membranes have lower content of both water and phosphorus and showed better porosity shape than CAAO. The RAAO membranes were used for template growth of carbon nanotubes (CNT) inside its pores by ethylene chemical vapour deposition (CVD) in the absence of a catalyst. A composite material, containing one nanotube for each channel, having the same length as the membrane thickness and an external diameter close to the diameter of the membrane holes, was obtained. Yield, selectivity and quality of CNTs in terms of diameter, length and arrangement (i.e. number of tubes for each channel) were optimized by investigating the effect of changing the experimental conditions for the CVD process. We showed that upon thermal treatment RAAO membranes were made up of crystallized allotropic alumina phases, which govern the subsequent CNT growth, because of their catalytic activity, likely due to their Lewis acidity. The strict control of experimental conditions for membrane preparation and CNT growth allowed us to enhance the carbon structural order, which is a critical requisite for CNT application as a substitute for copper in novel nano-interconnects.

Highly crystalline lithium titanium oxide sheets coated with nitrogen-doped carbon enable high-rate lithium-ion batteries.

PubMed

Han, Cuiping; He, Yan-Bing; Li, Baohua; Li, Hongfei; Ma, Jun; Du, Hongda; Qin, Xianying; Yang, Quan-Hong; Kang, Feiyu

2014-09-01

Sheets of Li4Ti5O12 with high crystallinity are coated with nitrogen-doped carbon (NC-LTO) using a controlled process, comprising hydrothermal reaction followed by chemical vapor deposition (CVD). Acetonitrile (CH3 CN) vapor is used as carbon and nitrogen source to obtain a thin coating layer of nitrogen-doped carbon. The layer enables the NC-LTO material to maintain its sheet structure during the high-temperature CVD process and to achieve high crystallinity. Doping with nitrogen introduces defects into the carbon coating layer, and this increased degree of disorder allows fast transportation of lithium ions in the layer. An electrode of NC-LTO synthesized at 700 °C exhibits greatly improved rate and cycling performance due to a markedly decreased total cell resistance and enhanced Li-ion diffusion coefficient (D(Li)). Specific capacities of 159.2 and 145.8 mA h g(-1) are obtained using the NC-LTO sheets, at charge/discharge rates of 1 and 10 C, respectively. These values are much higher than values for LTO particles did not undergo the acetonitrile CVD treatment. A capacity retention value as high as 94.7% is achieved for the NC-LTO sheets after 400 cycles in a half-cell at 5 C discharge rate. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cardiovascular benefits of lycopene: fantasy or reality?

PubMed

Thies, Frank; Mills, Lynsey M; Moir, Susan; Masson, Lindsey F

2017-05-01

Epidemiological evidence indicates that high consumption of tomatoes and tomato-based products reduces the risk of chronic diseases such as CVD and cancer. Such potential benefits are often ascribed to high concentrations of lycopene present in tomato products. Mainly from the results of in vitro studies, potential biological mechanisms by which carotenoids could protect against heart disease and cancer have been suggested. These include cholesterol reduction, inhibition of oxidation processes, modulation of inflammatory markers, enhanced intercellular communication, inhibition of tumourigenesis and induction of apoptosis, metabolism to retinoids and antiangiogenic effects. However, with regard to CVD, results from intervention studies gave mixed results. Over fifty human intervention trials with lycopene supplements or tomato-based products have been conducted to date, the majority being underpowered. Many showed some beneficial effects but mostly on non-established cardiovascular risk markers such as lipid peroxidation, DNA oxidative damage, platelet activation and inflammatory markers. Only a few studies showed improvement in lipid profiles, C reactive protein and blood pressure. However, recent findings indicate that lycopene could exert cardiovascular protection by lowering HDL-associated inflammation, as well as by modulating HDL functionality towards an antiatherogenic phenotype. Furthermore, in vitro studies indicate that lycopene could modulate T lymphocyte activity, which would also inhibit atherogenic processes and confer cardiovascular protection. These findings also suggest that HDL functionality deserves further consideration as a potential early marker for CVD risk, modifiable by dietary factors such as lycopene.

Work stress and cardiovascular disease: a life course perspective.

PubMed

Li, Jian; Loerbroks, Adrian; Bosma, Hans; Angerer, Peter

2016-05-25

Individuals in employment experience stress at work, and numerous epidemiological studies have documented its negative health effects, particularly on cardiovascular disease (CVD). Although evidence on the various interrelationships between work stress and CVD has been accumulated, those observations have not yet been conceptualized in terms of a life course perspective. Using the chain of risk model, we would like to propose a theoretical model incorporating six steps: (1) work stress increases the risk of incident CVD in healthy workers. (2) Among those whose work ability is not fully and permanently damaged, work stress acts as a determinant of the process of return to work after CVD onset. (3) CVD patients experience higher work stress after return to work. (4) Work stress increases the risk of recurrent CVD in workers with prior CVD. (5) CVD patients who fully lose their work ability transit to disability retirement. (6) Disability retirees due to CVD have an elevated risk of CVD mortality. The life course perspective might facilitate an in-depth understanding of the diverse interrelationships between work stress and CVD, thereby leading to work stress management interventions at each period of the lifespan and three-level prevention of CVD.

Retinal vascular imaging in early life: insights into processes and risk of cardiovascular disease

PubMed Central

Li, Ling‐Jun; Ikram, Mohammad Kamran

2015-01-01

Abstract Cardiovascular disease (CVD) is the leading cause of morbidity and mortality globally. In recent years, studies have shown that the origins of CVD may be traced to vascular and metabolic processes in early life. Retinal vascular imaging is a new technology that allows detailed non‐invasive in vivo assessment and monitoring of the microvasculature. In this systematic review, we described the application of retinal vascular imaging in children and adolescents, and we examined the use of retinal vascular imaging in understanding CVD risk in early life. We reviewed all publications with quantitative retinal vascular assessment in two databases: PubMed and Scopus. Early life CVD risk factors were classified into four groups: birth risk factors, environmental risk factors, systemic risk factors and conditions linked to future CVD development. Retinal vascular changes were associated with lower birth weight, shorter gestational age, low‐fibre and high‐sugar diet, lesser physical activity, parental hypertension history, childhood hypertension, childhood overweight/obesity, childhood depression/anxiety and childhood type 1 diabetes mellitus. In summary, there is increasing evidence supporting the view that structural changes in the retinal microvasculature are associated with CVD risk factors in early life. Thus, the retina is a useful site for pre‐clinical assessment of microvascular processes that may underlie the future development of CVD in adulthood. PMID:26435039

Alzheimer biomarkers and clinical Alzheimer disease were not associated with increased cerebrovascular disease in a memory clinic population.

PubMed

Spies, Petra E; Verbeek, Marcel M; Sjogren, Magnus J C; de Leeuw, Frank-Erik; Claassen, Jurgen A H R

2014-01-01

Preclinical and post-mortem studies suggest that Alzheimer disease (AD) causes cerebrovascular dysfunction, and therefore may enhance susceptibility to cerebrovascular disease (CVD). The objective of this study was to investigate this association in a memory clinic population. The AD biomarkers CSF amyloid β42, amyloid β40 and APOE-ε4 status have all been linked to increased CVD risk in AD, and therefore the first aim of this study was to analyze the association between these biomarkers and CVD. In 92 memory clinic patients the cross-sectional association between AD biomarkersand the severity of CVD was investigated with linear regression analysis. Additionally, we studied whether AD biomarkers modified the relation between vascular risk factors and CVD. CVD was assessed on MRI through a visual rating scale.Analyses were adjusted for age. The second aim of this study was to investigate the association between clinical AD and CVD, where 'clinical AD' was defined as follows: impairment in episodic memory, hippocampal atrophy and an aberrant concentration of cerebrospinal fluid (CSF) biomarkers. 47 of the 92 patients had AD. No association between CSF amyloid β42, amyloid β40 or APOE-ε4 status and CVD severity was found, nor did these AD biomarkers modify the relation between vascular risk factors and CVD. Clinical AD was not associated with CVD severity (p=0.83). Patients with more vascular risk factors had more CVD, but this relationship was not convincingly modified by AD (p=0.06). In this memory clinic population, CVD in patients with AD was related to vascular risk factors and age, comparable to patients without AD. Therefore, in our study, the preclinical and post-mortem evidence that AD would predispose to CVD could not be translated clinically. Further work, including replication of this work in a different and larger sample, is warranted.

Large-scale synthesis of high-quality hexagonal boron nitride nanosheets for large-area graphene electronics.

PubMed

Lee, Kang Hyuck; Shin, Hyeon-Jin; Lee, Jinyeong; Lee, In-yeal; Kim, Gil-Ho; Choi, Jae-Young; Kim, Sang-Woo

2012-02-08

Hexagonal boron nitride (h-BN) has received a great deal of attention as a substrate material for high-performance graphene electronics because it has an atomically smooth surface, lattice constant similar to that of graphene, large optical phonon modes, and a large electrical band gap. Herein, we report the large-scale synthesis of high-quality h-BN nanosheets in a chemical vapor deposition (CVD) process by controlling the surface morphologies of the copper (Cu) catalysts. It was found that morphology control of the Cu foil is much critical for the formation of the pure h-BN nanosheets as well as the improvement of their crystallinity. For the first time, we demonstrate the performance enhancement of CVD-based graphene devices with large-scale h-BN nanosheets. The mobility of the graphene device on the h-BN nanosheets was increased 3 times compared to that without the h-BN nanosheets. The on-off ratio of the drain current is 2 times higher than that of the graphene device without h-BN. This work suggests that high-quality h-BN nanosheets based on CVD are very promising for high-performance large-area graphene electronics. © 2012 American Chemical Society

The Autophagy Enhancer Spermidine Reverses Arterial Aging

PubMed Central

LaRocca, Thomas J.; Gioscia-Ryan, Rachel A.; Hearon, Christopher M.; Seals, Douglas R.

2013-01-01

Arterial aging, characterized by stiffening of large elastic arteries and the development of arterial endothelial dysfunction, increases cardiovascular disease (CVD) risk. We tested the hypothesis that spermidine, a nutrient associated with the anti-aging process autophagy, would improve arterial aging. Aortic pulse wave velocity (aPWV), a measure of arterial stiffness, was ~20% greater in old (O, 28 months) compared with young C57BL6 mice (Y, 4 months, P < 0.05). Arterial endothelium-dependent dilation (EDD), a measure of endothelial function, was ~25% lower in O (P < 0.05 vs. Y) due to reduced nitric oxide (NO) bioavailability. These impairments were associated with greater arterial oxidative stress (nitrotyrosine), superoxide production, and protein cross-linking (advanced glycation end-products, AGEs) in O (all P < 0.05). Spermidine supplementation normalized aPWV, restored NO-mediated EDD and reduced nitrotyrosine, superoxide, AGEs and collagen in O. These effects of spermidine were associated with enhanced arterial expression of autophagy markers, and in vitro experiments demonstrated that vascular protection by spermidine was autophagy-dependent. Our results indicate that spermidine exerts a potent anti-aging influence on arteries by increasing NO bioavailability, reducing oxidative stress, modifying structural factors and enhancing autophagy. Spermidine may be a promising nutraceutical treatment for arterial aging and prevention of age-associated CVD. PMID:23612189

Vertical graphene nanosheets synthesized by thermal chemical vapor deposition and the field emission properties

NASA Astrophysics Data System (ADS)

Guo, Xin; Qin, Shengchun; Bai, Shuai; Yue, Hongwei; Li, Yali; Chen, Qiang; Li, Junshuai; He, Deyan

2016-09-01

In this paper, we explored synthesis of vertical graphene nanosheets (VGNs) by thermal chemical vapor deposition (CVD). Through optimizing the experimental condition, growth of well aligned VGNs with uniform morphologies on nickel-coated stainless steel (SS) was realized for the first time by thermal CVD. In the meantime, influence of growth parameters on the VGN morphology was understood based on the balancing between the concentration and kinetic energy of carbon-containing radicals. Structural characterizations demonstrate that the achieved VGNs are normally composed of several graphene layers and less corrugated compared to the ones synthesized by other approaches, e.g. plasma enhanced (PE) CVD. The field emission measurement indicates that the VGNs exhibit relatively stable field emission and a field enhancement factor of about 1470, which is comparable to the values of VGNs prepared by PECVD can be achieved.

Dietary antioxidant capacity of the patients with cardiovascular disease in a cross-sectional study.

PubMed

Zujko, Małgorzata E; Witkowska, Anna M; Waśkiewicz, Anna; Piotrowski, Walerian; Terlikowska, Katarzyna M

2015-03-15

The purpose of this study was to establish sources and patterns of antioxidant, polyphenol and flavonoid intakes in men and women with cardiovascular disease (CVD). The subjects with CVD and healthy controls (HC) were participants of the Polish National Multicenter Health Survey (WOBASZ). Food intakes were measured with the 1-day 24-hour recall method. A self-developed database was used to calculate dietary total antioxidant capacity (DTAC), dietary total polyphenol content (DTPC) and dietary total flavonoid content (DTFC). DTAC did not differ between the men with CVD and HC men (6442 vs. 6066 μmol trolox equivalents - TE), but in the women with CVD it was significantly higher than in the HC women (6182 vs. 5500 μmol TE). The main sources of antioxidants in the males with CVD were: tea, coffee, apples, and nuts and seeds, and tea, coffee and apples in HC. In the females they were: tea, coffee, apples and strawberries, both in the women with CVD and HC. DTPC in the men with CVD did not differ from HC (1198 vs. 1114 mg gallic acid equivalents, GAE). In the females, DTPC was significantly higher in the subjects with CVD as compared to HC (1075 vs. 981 mg GAE). Predominant sources of polyphenols were: tea, coffee, cabbage, potatoes, apples and white bread in the men with CVD, and tea, coffee, potatoes, white bread and apples in HC, while in the women (both with CVD and HC): tea, coffee, apples, potatoes and cabbage. No differences in DTFC have been found between the males with CVD and HC (212 vs. 202 mg quercetine equivalents, QE). In the women with CVD, DTFC was significantly higher than in HC (200 vs. 177 mg QE). Main sources of flavonoids in all participants (men and women, CVD and HC) were tea, apples, cabbage and coffee. Polish men and women faced with CVD beneficially modify their dietary practices by enhancing intakes of foods that are sources of antioxidants, polyphenols and flavonoids. Different sources and patterns of antioxidant, polyphenol and flavonoid intakes, however, between male and female patients with CVD were observed.

Cardiovascular Disease Prevention and Health Promotion with the Transcendental Meditation Program and Maharishi Consciousness-Based Health Care

PubMed Central

Schneider, Robert H.; Walton, Kenneth G.; Salerno, John W.; Nidich, Sanford I.

2008-01-01

This article summarizes the background, rationale, and clinical research on a traditional system of natural health care that may be useful in the prevention of cardiovascular disease (CVD) and promotion of health. Results recently reported indude reductions in blood pressure, psychosocial stress, surrogate markers for atherosclerotic CVD, and mortality. The randomized clinical trials conducted so far have involved applications to both primary and secondary prevention as well as to health promotion more generally. The results support the applicability of this approach for reducing ethnic health disparities associated with environmental and psychosocial stress. Proposed mechanisms for the effects of this traditional system include enhanced resistance to physiological and psychological stress and improvements in homeostatic and self-repair processes. This system may offer clinical and cost effectiveness advantages for health care, particularly in preventive cardiology. PMID:16938913

Enhancing quality of carbon nanotubes through a real-time controlled CVD process with application to next-generation nanosystems

NASA Astrophysics Data System (ADS)

Laxminarayana, Karthik; Jalili, Nader

2004-07-01

Nanocrystals and nanostructures will be the building blocks for future materials that will exhibit enhanced or entirely new combinations of properties with tremendous opportunity for novel technologies that can have far-reaching impact on our society. It is, however, realized that a major challenge for the near future is the design, synthesis and integration of nanostructures to develop functional nanosystems. In view of this, this exploratory research seeks to facilitate the development of a controlled and deterministic framework for nanomanufacturing of nanotubes as the most suitable choice among nanostructures for a plethora of potential applications in areas such as nanoelectronic devices, biological probes, fuel cell electrodes, supercapacitors and filed emission devices. Specifically, this paper proposes to control and maintain the most common nanotube growth parameters (i.e., reaction temperature and gas flow rate) through both software and hardware modifications. The influence of such growth parameters in a CVD process on some of the most vital and crucial aspects of nanotubes (e.g., length, diameter, yield, growth rate and structure) can be utilized to arrive at some unique and remarkable properties for the nanotubes. The objective here is, therefore, to control the process parameters to pinpoint accuracy, which would enable us to fabricate nanotubes having the desired properties and thereby maximize their ability to function at its fullest potential. To achieve this and in order to provide for experimental validation of the proposed research program, an experimental test-bed using the nanotube processing test chamber and a mechatronics workstation are being constructed.

Water-Assisted Vapor Deposition of PEDOT Thin Film.

PubMed

Goktas, Hilal; Wang, Xiaoxue; Ugur, Asli; Gleason, Karen K

2015-07-01

The synthesis and characterization of poly(3,4-ethylenedioxythiophene) (PEDOT) using water-assisted vapor phase polymerization (VPP) and oxidative chemical vapor deposition (oCVD) are reported. For the VPP PEDOT, the oxidant, FeCl3 , is sublimated onto the substrate from a heated crucible in the reactor chamber and subsequently exposed to 3,4-ethylenedioxythiophene (EDOT) monomer and water vapor in the same reactor. The oCVD PEDOT was produced by introducing the oxidant, EDOT monomer, and water vapor simultaneously to the reactor. The enhancement of doping and crystallinity is observed in the water-assisted oCVD thin films. The high doping level observed at UV-vis-NIR spectra for the oCVD PEDOT, suggests that water acts as a solubilizing agent for oxidant and its byproducts. Although the VPP produced PEDOT thin films are fully amorphous, their conductivities are comparable with that of the oCVD produced ones. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Drastically Enhanced High-Rate Performance of Carbon-Coated LiFePO4 Nanorods Using a Green Chemical Vapor Deposition (CVD) Method for Lithium Ion Battery: A Selective Carbon Coating Process.

PubMed

Tian, Ruiyuan; Liu, Haiqiang; Jiang, Yi; Chen, Jiankun; Tan, Xinghua; Liu, Guangyao; Zhang, Lina; Gu, Xiaohua; Guo, Yanjun; Wang, Hanfu; Sun, Lianfeng; Chu, Weiguo

2015-06-03

Application of LiFePO4 (LFP) to large current power supplies is greatly hindered by its poor electrical conductivity (10(-9) S cm(-1)) and sluggish Li+ transport. Carbon coating is considered to be necessary for improving its interparticle electronic conductivity and thus electrochemical performance. Here, we proposed a novel, green, low cost and controllable CVD approach using solid glucose as carbon source which can be extended to most cathode and anode materials in need of carbon coating. Hydrothermally synthesized LFP nanorods with optimized thickness of carbon coated by this recipe are shown to have superb high-rate performance, high energy, and power densities, as well as long high-rate cycle lifetime. For 200 C (18s) charge and discharge, the discharge capacity and voltage are 89.69 mAh g(-1) and 3.030 V, respectively, and the energy and power densities are 271.80 Wh kg(-1) and 54.36 kW kg(-1), respectively. The capacity retention of 93.0%, and the energy and power density retention of 93.6% after 500 cycles at 100 C were achieved. Compared to the conventional carbon coating through direct mixing with glucose (or other organic substances) followed by annealing (DMGA), the carbon phase coated using this CVD recipe is of higher quality and better uniformity. Undoubtedly, this approach enhances significantly the electrochemical performance of high power LFP and thus broadens greatly the prospect of its applications to large current power supplies such as electric and hybrid electric vehicles.

A Markov model of the cost-effectiveness of pharmacist care for diabetes in prevention of cardiovascular diseases: evidence from Kaiser Permanente Northern California.

PubMed

Yu, Junhua; Shah, Bijal M; Ip, Eric J; Chan, James

2013-03-01

It has been demonstrated in previous studies that pharmacist management of patients with type 2 diabetes mellitus (T2DM) in the outpatient setting not only improves diabetes-related clinical outcomes such as hemoglobin A1c but also blood pressure (BP), total cholesterol (TC), and quality of life. Improved control of BP and TC has been shown to reduce the risks of cardiovascular disease (CVD), which has placed a heavy economic burden on the health care system. However, no study has evaluated the cost-effectiveness of pharmacist intervention programs with respect to the long-term preventive effects on CVD outcomes among T2DM patients. To (a) quantify the long-term preventive effects of pharmacist intervention on CVD outcomes among T2DM patients using evidence from a matched cohort study in the outpatient primary care setting and (b) assess the relative cost-effectiveness of adding a clinical pharmacist to the primary care team for the management of patients with T2DM based on improvement in CVD risks with the aid of an economic model. Clinical data between the periods of June 2007 to February 2010 were collected from electronic medical records at 2 separate clinics at Kaiser Permanente (KP) Northern California, 1 with primary care physicians only (control group) and the other with the addition of a pharmacist (enhanced care group). Patients in the enhanced care group were matched 1:1 with patients in the control group according to baseline characteristics that included age, gender, A1c, and Charlson comorbidity score. The estimated 10-year CVD risk for both groups was calculated by the United Kingdom Prospective Diabetes Study (UKPDS) Risk Engine (version 2) based on age, sex, race, smoking status, atrial fibrillation, duration of diabetes, levels of A1c, systolic BP (SBP) and TC, and high-density lipoprotein cholesterol (HDL-C) observed at 12 months. There was no statistical difference in the baseline clinical inputs to the Risk Engine (A1c [P=0.115], SBP [P=0.184], TC [P=0.055], and HDL-C [P=0.475]) between the 2 groups. A Markov model was developed to simulate the estimated CVD outcomes over 10 years and to estimate cost-effectiveness. The final outcomes examined included incremental cost and effectiveness measured by life years and per quality-adjusted life year gained. Both deterministic sensitivity analysis (SA) and probabilistic SA were conducted to examine the robustness of the results. The estimated risks for coronary heart disease (CHD) and stroke (both nonfatal and fatal) at the end of the follow-up were consistently lower in the enhanced care group compared with the control group, even though baseline risks in both groups were similar. The absolute risk reduction (ARR) between the enhanced care and control groups increased over time. For example, the ARR for nonfatal CHD risk in year 1 was 0.5% (1.2% vs. 0.7%), whereas the ARR increased to 5.5% in year 10 (14.8% vs. 9.3%). Similarly, the ARR between the enhanced care and the control groups was calculated as 0.3% for fatal CHD in year 1 and increased to 4.6% in year 10. Results from the Markov model suggest that the enhanced care group was shown to be a dominant strategy (less expensive and more effective) compared with the control group in the 10-year evaluation period in the base-case (average or mean results) scenario. Sensitivity analysis that took into account the uncertainty in all important variables, such as wage of pharmacists, utility weight (the degree of preference individuals have for a particular health state or condition), response rate to pharmacists' care, and uncertainty associated with the estimated 10 years of CVD risk, revealed that the relative value of enhanced care was robust to most of the variations in these parameters. Notably, the level of cost-effectiveness measured by net monetary value depends on the time horizon adopted by the payers and the magnitude of CVD risk reduction. The enhanced care group has a higher chance of being considered as a cost-effective strategy when a longer time horizon such as a minimum of 4 to 5 years is adopted. Adding pharmacists to the health care management team for diabetic patients improves the long-term CVD risks. The longer-term CVD risk reductions were shown to be more dramatic than the short-term reduction. A longer time horizon adopted by health plans in managing T2DM patients has a higher probability of making the intervention cost-effective.

Direct growth of high crystallinity graphene from water-soluble polymer powders

NASA Astrophysics Data System (ADS)

Chen, Qiao; Zhong, Yujia; Huang, Meirong; Zhao, Guoke; Zhen, Zhen; Zhu, Hongwei

2018-07-01

The use of solid-state carbon sources is effective to produce graphene by safe and low-cost chemical vapor deposition (CVD) process. Water-soluble polymers are generally environmentally friendly and have great potential on large-scale green production of graphene. Here, we systematically study the growth of graphene from water-soluble polymers on copper foils. Two different conversion ways are adopted to investigate the growth mechanism of graphene from water-soluble polymers. We find that the metal-binding functional group hydroxyl strongly influences the vaporization of water-soluble polymers on Cu foils, which hinders the formation of graphene films by rapid thermal treatment. In direct CVD process using water-soluble polymer powders as precursors, oxygenated functional groups in polymers can enhance the crystallinity of as-grown graphene in contrast to solid hydrocarbons without containing oxygen (e.g. polyethylene). Large and continuous graphene films of high quality are synthesized from polyvinyl alcohol and polyethylene glycol. Nitrogen doping in graphene can be easily realized by using nitrogen-containing water-soluble polymers (e.g. polyvinyl pyrrolidone).

A Community-Engaged Cardiovascular Health Disparities Research Training Curriculum: Implementation and Preliminary Outcomes

PubMed Central

Golden, Sherita Hill; Purnell, Tanjala; Halbert, Jennifer P.; Matens, Richard; Miller, Edgar R. “Pete”; Levine, David M.; Nguyen, Tam H.; Gudzune, Kimberly A.; Crews, Deidra C.; Mahlangu-Ngcobo, Mankekolo; Cooper, Lisa A.

2014-01-01

To overcome cardiovascular disease (CVD) disparities impacting high-risk populations, it is critical to train researchers and leaders in conducting community-engaged CVD disparities research. The authors summarize the key elements, implementation, and preliminary outcomes of the CVD Disparities Fellowship and Summer Internship Programs at the Johns Hopkins University Schools of Medicine, Nursing, and Bloomberg School of Public Health. In 2010, program faculty and coordinators established a trans-disciplinary CVD disparities training and career development fellowship program for scientific investigators who desire to conduct community-engaged clinical and translational disparities research. The program was developed to enhance mentorship support and research training for faculty, post-doctoral fellows, and pre-doctoral students interested in conducting CVD disparities research. A CVD Disparities Summer Internship Program for undergraduate and pre-professional students was also created to provide a broad experience in public health and health disparities in Baltimore, Maryland, with a focus on CVD. Since 2010, 39 pre-doctoral, post-doctoral, and faculty fellows have completed the program. Participating fellows have published disparities-related research and given presentations both nationally and internationally. Five research grant awards have been received by faculty fellows. Eight undergraduates, 1 post-baccalaureate, and 2 medical professional students representing seven universities have participated in the summer undergraduate internship. Over half of the undergraduate students are applying to or have been accepted into medical or graduate school. The tailored CVD health disparities training curriculum has been successful at equipping varying levels of trainees (from undergraduate students to faculty) with clinical research and public health expertise to conducting community-engaged CVD disparities research. PMID:25054421

Cerebrovascular disease, beta-amyloid and cognition in aging

PubMed Central

Marchant, Natalie L.; Reed, Bruce R.; DeCarli, Charles S.; Madison, Cindee M.; Weiner, Michael W.; Chui, Helena C.; Jagust, William J.

2011-01-01

The present study evaluated cerebrovascular disease (CVD), β-amyloid (Aβ), and cognition in clinically normal elderly adults. Fifty-four participants underwent MRI, PIB-PET imaging, and neuropsychological evaluation. High white matter hyperintensity burden and/or presence of infarct defined CVD status (CVD−: N = 27; CVD+: N = 27). PIB-PET ratios of Aβ deposition were extracted using Logan plotting (cerebellar reference). Presence of high levels of Aβ in prespecified regions determined PIB status (PIB−: N = 33; PIB+: N = 21). Executive functioning and episodic memory were measured using composite scales. CVD and Aβ, defined as dichotomous or continuous variables, were unrelated to one another. CVD+ participants showed lower executive functioning (P = 0.001) when compared to CVD− individuals. Neither PIB status nor amount of Aβ affected cognition (Ps ≥ .45), and there was no statistical interaction between CVD and PIB on either cognitive measure. Within this spectrum of normal aging CVD and Aβ aggregation appear to be independent processes with CVD primarily affecting cognition. PMID:22048124

Management of cardiovascular disease in African-American women: utility of the metabolic syndrome guidelines.

PubMed

Blevins, Lisa P; Berry, Diane; Barksdale, Debra J

2008-07-01

Cardiovascular disease (CVD) is the leading cause of death in the Unites States and is disproportionately more prevalent among African-American women than members of other ethnic groups. The National Cholesterol Education Adult Treatment Panel III (ATP III) metabolic syndrome guidelines are useful in clinical practice to identify individuals who are at risk for developing CVD. Amendments to the ATP III criteria might be indicated to enhance early identification of CVD risk factors among African-American women, even when only one or two of the criteria are met. The addition of body mass index (BMI) and the identification of acanthosis nigricans as a marker of insulin resistance to the ATP III metabolic syndrome guidelines might facilitate early CVD risk identification, strategy implementation, and reduction of premature morbidity and mortality within this population.

Control of Reaction Surface in Low Temperature CVD to Enhance Nucleation and Conformal Coverage

ERIC Educational Resources Information Center

Kumar, Navneet

2009-01-01

The Holy Grail in CVD community is to find precursors that can afford the following: good nucleation on a desired substrate and conformal deposition in high AR features. Good nucleation is not only necessary for getting ultra-thin films at low thicknesses; it also offers films that are smooth at higher thickness values. On the other hand,…

Perceptions and Motivations to Prevent Heart Disease among Puerto Ricans

PubMed Central

Mattei, Josiemer; Mendez, Jacqueline; Falcon, Luis M.; Tucker, Katherine L.

2016-01-01

Objectives We performed a qualitative assessment of Puerto Ricans’ knowledge and perceptions of cardiovascular disease (CVD), and motivations/barriers and preferences to participate in community/ clinical programs for CVD-prevention. Methods Four guided focus group discussions were conducted on a total of 24 Puerto Ricans, aged 40–60 years in Boston, MA. Results Participants were aware of CVD, but less knowledgeable about its prevention. They perceived it as serious, and either had CVD or knew someone who had it. They favored education and activities on nutrition, exercise, clinical advice, and social interaction, in weekly/ biweekly small-group sessions with other Latinos, led in Spanish by a familiar health professional, in a convenient community location. Age- and culture-specific program content and educational materials were preferred. A theme emerged on ‘personal or family motivations’ such as to become healthier and live longer so they would feel better and support their families, or to learn about CVD-prevention. Main barriers included family obligations, weather, safety concerns, transportation, and depressive mood. Conclusions Culturally-tailored CVD-prevention programs for Puerto Ricans should include multiple behavioral and social approaches, and draw on intrinsic motivators while reducing barriers to help enhance efficacy and sustainability. PMID:27103411

Measuring Childhood Adversity in Life Course Cardiovascular Research: A Systematic Review.

PubMed

Appleton, Allison A; Holdsworth, Elizabeth; Ryan, Margaret; Tracy, Melissa

2017-05-01

Identifying the life course health effects of childhood adversity is a burgeoning area of research, particularly in relation to cardiovascular disease (CVD). However, adversity measurement varies widely across studies, which may hamper our ability to make comparisons across studies and identify mechanisms linking adversity to CVD. The purposes of this review are to summarize adversity measurement approaches in the context of CVD, identify gaps, and make recommendations for future research. PubMed and PsycINFO searches were conducted through June 2016. Studies were selected if CVD end point or predisease risk markers were investigated in association with a measure of childhood adversity. Forty-three studies were reviewed. A meta-analysis was not conducted because of the variation in exposures and outcomes assessed. Adversity measurement was heterogeneous across studies. Metrics included different sets of adverse events, relational factors, and socioeconomic indicators. Thirty-seven percent measured childhood adversity prospectively, 23% examined a CVD end point, and 77% treated adversity as an unweighted summary score. Despite the heterogeneity in measurement, most studies found a positive association between childhood adversity and CVD risk, and the association seems to be dose-response. The literature on childhood adversity and CVD would benefit from improving consistency of measurement, using weighted adversity composites, modeling adversity trajectories over time, and considering socioeconomic status as an antecedent factor instead of a component part of an adversity score. We suggest conceptual and analytic strategies to enhance, refine, and replicate the observed association between childhood adversity and CVD risk.

Family history of cardiovascular disease (CVD), perceived CVD risk, and health-related behavior: A review of the literature

PubMed Central

Imes, Christopher C.; Lewis, Frances Marcus

2012-01-01

Background Over 82 million Americans have one or more forms of cardiovascular disease (CVD), accounting for 32.8% of all deaths in the United States. Although the evidence for the familial aggregation of CVD is strong, the relationship between family history (FH) of CVD, perceived risk for CVD and their relationship to health-related behavior is poorly understood. Objective The objective of this article is to review and summarize the published research on the relationship between a FH of CVD, an individual’s perceived risk, and health-related behavior in order to make recommendations for clinical practice and future research. Methods A literature search was conducted using PubMed, CINAHL Plus, and PsycINFO to identify articles that examined the relationship between a FH of CVD, perceived CVD risk, and health-promoting behaviors. A total of 263 unique articles were reviewed. Two hundred thirty-eight were excluded, resulting in a total of 25 articles included in the paper. Results There was a positive relationship between a reported FH of CVD and perceived risk. However, the relationship between a FH of CVD and health-related behavior change and perceived risk and behavior change was inconsistent. Conclusions A person’s awareness of their FH of CVD or their own risk for CVD is not a sufficient predictor of changes in their health-related behavior. Future studies are needed to better explain the processes by which perceived CVD risk or FH of CVD can be used to affect health-related behavior changes. It appears that both FH and perceived personal risk for CVD are necessary but not sufficient conditions to change health-related behavior in high-risk populations. Future studies should also test interventions that help individuals with a FH of CVD attribute increased personal risk to themselves for developing CVD, while providing lifestyle management options to minimize their risk. PMID:23321782

Evaluation of infrared thermography as a diagnostic tool in CVD applications

NASA Astrophysics Data System (ADS)

Johnson, E. J.; Hyer, P. V.; Culotta, P. W.; Clark, I. O.

1998-05-01

This research is focused on the feasibility of using infrared temperature measurements on the exterior of a chemical vapor deposition (CVD) reactor to ascertain both real-time information on the operating characteristics of a CVD system and provide data which could be post-processed to provide quantitative information for research and development on CVD processes. Infrared thermography techniques were used to measure temperatures on a horizontal CVD reactor of rectangular cross section which were correlated with the internal gas flow field, as measured with the laser velocimetry (LV) techniques. For the reactor tested, thermal profiles were well correlated with the gas flow field inside the reactor. Correlations are presented for nitrogen and hydrogen carrier gas flows. The infrared data were available to the operators in real time with sufficient sensitivity to the internal flow field so that small variations such as misalignment of the reactor inlet could be observed. The same data were post-processed to yield temperature measurements at known locations on the reactor surface. For the experiments described herein, temperatures associated with approximately 3.3 mm 2 areas on the reactor surface were obtained with a precision of ±2°C. These temperature measurements were well suited for monitoring a CVD production reactor, development of improved thermal boundary conditions for use in CFD models of reactors, and for verification of expected thermal conditions.

NEXAFS Study of the Annealing Effect on the Local Structure of FIB-CVD DLC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saikubo, Akihiko; Kato, Yuri; Igaki, Jun-ya

2007-01-19

Annealing effect on the local structure of diamond like carbon (DLC) formed by focused ion beam-chemical vapor deposition (FIB-CVD) was investigated by the measurement of near edge x-ray absorption fine structure (NEXAFS) and energy dispersive x-ray (EDX) spectra. Carbon K edge absorption NEXAFS spectrum of FIB-CVD DLC was measured in the energy range of 275-320 eV. In order to obtain the information on the location of the gallium in the depth direction, incidence angle dependence of NEXAFS spectrum was measured in the incident angle range from 0 deg. to 60 deg. . The peak intensity corresponding to the resonance transitionmore » of 1s{yields}{sigma}* originating from carbon-gallium increased from the FIB-CVD DLC annealed at 200 deg. C to the FIB-CVD DLC annealed at 400 deg. C and decreased from that at 400 deg. C to that at 600 deg. C. Especially, the intensity of this peak remarkably enhanced in the NEXAFS spectrum of the FIB-CVD DLC annealed at 400 deg. C at the incident angle of 60 deg. . On the contrary, the peak intensity corresponding to the resonance transition of 1s{yields}{pi}* originating from carbon double bonding of emission spectrum decreased from the FIB-CVD DLC annealed at 200 deg. C to that at 400 deg. C and increased from that at 400 deg. C to that at 600 deg. C. Gallium concentration in the FIB-CVD DLC decreased from {approx_equal}2.2% of the as-deposited FIB-CVD DLC to {approx_equal}1.5% of the FIB-CVD DLC annealed at 600 deg. C from the elementary analysis using EDX. Both experimental results indicated that gallium atom departed from FIB-CVD DLC by annealing at the temperature of 600 deg. C.« less

Photoinitiated chemical vapor deposition of cytocompatible poly(2-hydroxyethyl methacrylate) films.

PubMed

McMahon, Brian J; Pfluger, Courtney A; Sun, Bing; Ziemer, Katherine S; Burkey, Daniel D; Carrier, Rebecca L

2014-07-01

Poly(2-hydroxyethyl methacrylate) (pHEMA) is a widely utilized biomaterial due to lack of toxicity and suitable mechanical properties; conformal thin pHEMA films produced via chemical vapor deposition (CVD) would thus have broad biomedical applications. Thin films of pHEMA were deposited using photoinitiated CVD (piCVD). Incorporation of ethylene glycol diacrylate (EGDA) into the pHEMA polymer film as a crosslinker, confirmed via Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy, resulted in varied swelling and degradation behavior. 2-Hydroxyethyl methacrylate-only films showed significant thickness loss (up to 40%), possibly due to extraction of low-molecular-weight species or erosion, after 24 h in aqueous solution, whereas films crosslinked with EGDA (9.25-12.4%) were stable for up to 21 days. These results differ significantly from those obtained with plasma-polymerized pHEMA, which degraded steadily over a 21-day period, even with crosslinking. This suggests that the piCVD films differ structurally from those fabricated via plasma polymerization (plasma-enhanced CVD). piCVD pHEMA coatings proved to be good cell culture materials, with Caco-2 cell attachment and viability comparable to results obtained on tissue-culture polystyrene. Thus, thin film CVD pHEMA offers the advantage of enabling conformal coating of a cell culture substrate with tunable properties depending on method of preparation and incorporation of crosslinking agents. © 2013 Wiley Periodicals, Inc.

Transport mechanisms through PE-CVD coatings: influence of temperature, coating properties and defects on permeation of water vapour

NASA Astrophysics Data System (ADS)

Kirchheim, Dennis; Jaritz, Montgomery; Mitschker, Felix; Gebhard, Maximilian; Brochhagen, Markus; Hopmann, Christian; Böke, Marc; Devi, Anjana; Awakowicz, Peter; Dahlmann, Rainer

2017-03-01

Gas transport mechanisms through plastics are usually described by the temperature-dependent Arrhenius-model and compositions of several plastic layers are represented by the CLT. When it comes to thin films such as plasma-enhanced chemical vapour deposition (PE-CVD) or plasma-enhanced atomic layer deposition (PE-ALD) coatings on substrates of polymeric material, a universal model is lacking. While existing models describe diffusion through defects, these models presume that permeation does not occur by other means of transport mechanisms. This paper correlates the existing transport models with data from water vapour transmission experiments.

Scalable graphene coatings for enhanced condensation heat transfer.

PubMed

Preston, Daniel J; Mafra, Daniela L; Miljkovic, Nenad; Kong, Jing; Wang, Evelyn N

2015-05-13

Water vapor condensation is commonly observed in nature and routinely used as an effective means of transferring heat with dropwise condensation on nonwetting surfaces exhibiting heat transfer improvement compared to filmwise condensation on wetting surfaces. However, state-of-the-art techniques to promote dropwise condensation rely on functional hydrophobic coatings that either have challenges with chemical stability or are so thick that any potential heat transfer improvement is negated due to the added thermal resistance of the coating. In this work, we show the effectiveness of ultrathin scalable chemical vapor deposited (CVD) graphene coatings to promote dropwise condensation while offering robust chemical stability and maintaining low thermal resistance. Heat transfer enhancements of 4× were demonstrated compared to filmwise condensation, and the robustness of these CVD coatings was superior to typical hydrophobic monolayer coatings. Our results indicate that graphene is a promising surface coating to promote dropwise condensation of water in industrial conditions with the potential for scalable application via CVD.

Comparative study of organic transistors with different graphene electrodes fabricated using a simple patterning method

NASA Astrophysics Data System (ADS)

Kang, Narae; Smith, Christian W.; Ishigami, Masa; Khondaker, Saiful I.

2017-12-01

The performance of organic field-effect transistors (OFETs) can be greatly limited due to the inefficient charge injection caused by the large interfacial barrier at the metal/organic semiconductor interface. To improve this, two-dimensional graphene films have been suggested as alternative electrode materials; however, a comparative study of OFET performances using different types of graphene electrodes has not been systematically investigated. Here, we present a comparative study on the performance of pentacene OFETs using chemical vapor deposition (CVD) grown graphene and reduced graphene oxide (RGO) as electrodes. The large area electrodes were patterned using a simple and environmentally benign patterning technique. Although both the CVD graphene and RGO electrodes showed enhanced device performance compared to metal electrodes, we found the maximum performance enhancement from CVD grown graphene electrodes. Our study suggests that, in addition to the strong π-π interaction at the graphene/organic interface, the higher conductivity of the electrodes also plays an important role in the performance of OFETs.

Low-temperature growth of nitrogen-doped carbon nanofibers by acetonitrile catalytic CVD using Ni-based catalysts

NASA Astrophysics Data System (ADS)

Iwasaki, Tomohiro; Makino, Yuri; Fukukawa, Makoto; Nakamura, Hideya; Watano, Satoru

2016-11-01

To synthesize nitrogen-doped carbon nanofibers (N-CNFs) at high growth rates and low temperatures less than 673 K, nickel species (metallic nickel and nickel oxide) supported on alumina particles were used as the catalysts for an acetonitrile catalytic chemical vapor deposition (CVD) process. The nickel:alumina mass ratio in the catalysts was fixed at 0.05:1. The catalyst precursors were prepared from various nickel salts (nitrate, chloride, sulfate, acetate, and lactate) and then calcined at 1073 K for 1 h in oxidative (air), reductive (hydrogen-containing argon), or inert (pure argon) atmospheres to activate the nickel-based catalysts. The effects of precursors and calcination atmosphere on the catalyst activity at low temperatures were studied. We found that the catalysts derived from nickel nitrate had relatively small crystallite sizes of nickel species and provided N-CNFs at high growth rates of 57 ± 4 g-CNF/g-Ni/h at 673 K in the CVD process using 10 vol% hydrogen-containing argon as the carrier gas of acetonitrile vapor, which were approximately 4 times larger than that of a conventional CVD process. The obtained results reveal that nitrate ions in the catalyst precursor and hydrogen in the carrier gas can contribute effectively to the activation of catalysts in low-temperature CVD. The fiber diameter and nitrogen content of N-CNFs synthesized at high growth rates were several tens of nanometers and 3.5 ± 0.3 at.%, respectively. Our catalysts and CVD process may lead to cost reductions in the production of N-CNFs.

A novel Mo-W interlayer approach for CVD diamond deposition on steel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kundrát, Vojtěch; Sullivan, John; Ye, Haitao, E-mail: h.ye@aston.ac.uk

Steel is the most widely used material in engineering for its cost/performance ratio and coatings are routinely applied on its surface to further improve its properties. Diamond coated steel parts are an option for many demanding industrial applications through prolonging the lifetime of steel parts, enhancement of tool performance as well as the reduction of wear rates. Direct deposition of diamond on steel using conventional chemical vapour deposition (CVD) processes is known to give poor results due to the preferential formation of amorphous carbon on iron, nickel and other elements as well as stresses induced from the significant difference inmore » the thermal expansion coefficients of those materials. This article reports a novel approach of deposition of nanocrystalline diamond coatings on high-speed steel (M42) substrates using a multi-structured molybdenum (Mo) – tungsten (W) interlayer to form steel/Mo/Mo-W/W/diamond sandwich structures which overcome the adhesion problem related to direct magnetron sputtering deposition of pure tungsten. Surface, interface and tribology properties were evaluated to understand the role of such an interlayer structure. The multi-structured Mo-W interlayer has been proven to improve the adhesion between diamond films and steel substrates by acting as an effective diffusion barrier during the CVD diamond deposition.« less

A novel Mo-W interlayer approach for CVD diamond deposition on steel

NASA Astrophysics Data System (ADS)

Kundrát, Vojtěch; Zhang, Xiaoling; Cooke, Kevin; Sun, Hailin; Sullivan, John; Ye, Haitao

2015-04-01

Steel is the most widely used material in engineering for its cost/performance ratio and coatings are routinely applied on its surface to further improve its properties. Diamond coated steel parts are an option for many demanding industrial applications through prolonging the lifetime of steel parts, enhancement of tool performance as well as the reduction of wear rates. Direct deposition of diamond on steel using conventional chemical vapour deposition (CVD) processes is known to give poor results due to the preferential formation of amorphous carbon on iron, nickel and other elements as well as stresses induced from the significant difference in the thermal expansion coefficients of those materials. This article reports a novel approach of deposition of nanocrystalline diamond coatings on high-speed steel (M42) substrates using a multi-structured molybdenum (Mo) - tungsten (W) interlayer to form steel/Mo/Mo-W/W/diamond sandwich structures which overcome the adhesion problem related to direct magnetron sputtering deposition of pure tungsten. Surface, interface and tribology properties were evaluated to understand the role of such an interlayer structure. The multi-structured Mo-W interlayer has been proven to improve the adhesion between diamond films and steel substrates by acting as an effective diffusion barrier during the CVD diamond deposition.

Association of sleep-disordered breathing with severe chronic vascular disease in patients with type 2 diabetes.

PubMed

Stadler, Stefan; Jalili, Shabnam; Schreib, Andreas; Jung, Bettina; Zeman, Florian; Böger, Carsten A; Heid, Iris M; Arzt, Michael

2018-05-14

Severe chronic vascular disease (CVD) is a major cause of co-morbidity and mortality in patients with type 2 diabetes (DM2). Sleep-disordered breathing (SDB) has been linked to CVD in the general population due to enhanced sympathetic activation, oxidative stress, endothelial dysfunction, and hypertension; however data for DM2 patients is scarce. Therefore, the aim of the present analysis to assess whether SDB is associated with CVD in patients with DM2, independent of other known associated factors. We analyzed cross-sectional data of 679 patients with DM2 from the DIACORE-SDB sub-study for association of SDB with CVD. SDB was assessed with a validated 2-channel ambulatory monitoring device. CVD was ascertained as a previous diagnosis of peripheral artery disease (PAD), coronary artery disease (CAD), or stroke via medical records and general practitioners. Of the analyzed 679 patients, 228 (34%) had SDB (respiratory event index [REI] ≥15/hour); and were significantly more often affected by CVD than patients without SDB (38% vs. 23%, p < 0.01; PAD 7% vs. 2%, p = 0.01; CAD 27% vs. 18%, p = 0.01; stroke 11% vs. 6%, p = 0.07). Regression analysis accounting for known modulators of CVD, such as age, body-mass index, systolic blood pressure, duration of DM2, HbA1c, smoking status, and low-density lipoprotein showed that the REI was independently associated with CVD (OR 1.099 per 5 REI points; 95%CI = [1.024, 1.179]). In patients with DM2, SDB is significantly associated with CVD, independent of other known modulators of atherosclerosis. Copyright © 2018 Elsevier B.V. All rights reserved.

Catalytic CVD synthesis of boron nitride and carbon nanomaterials - synergies between experiment and theory.

PubMed

McLean, Ben; Eveleens, Clothilde A; Mitchell, Izaac; Webber, Grant B; Page, Alister J

2017-10-11

Low-dimensional carbon and boron nitride nanomaterials - hexagonal boron nitride, graphene, boron nitride nanotubes and carbon nanotubes - remain at the forefront of advanced materials research. Catalytic chemical vapour deposition has become an invaluable technique for reliably and cost-effectively synthesising these materials. In this review, we will emphasise how a synergy between experimental and theoretical methods has enhanced the understanding and optimisation of this synthetic technique. This review examines recent advances in the application of CVD to synthesising boron nitride and carbon nanomaterials and highlights where, in many cases, molecular simulations and quantum chemistry have provided key insights complementary to experimental investigation. This synergy is particularly prominent in the field of carbon nanotube and graphene CVD synthesis, and we propose here it will be the key to future advances in optimisation of CVD synthesis of boron nitride nanomaterials, boron nitride - carbon composite materials, and other nanomaterials generally.

Processed red meat contribution to dietary patterns and the associated cardio-metabolic outcomes.

PubMed

Lenighan, Yvonne M; Nugent, Anne P; Li, Kaifeng F; Brennan, Lorraine; Walton, Janette; Flynn, Albert; Roche, Helen M; McNulty, Breige A

2017-08-01

Evidence suggests that processed red meat consumption is a risk factor for CVD and type 2 diabetes (T2D). This analysis investigates the association between dietary patterns, their processed red meat contributions, and association with blood biomarkers of CVD and T2D, in 786 Irish adults (18-90 years) using cross-sectional data from a 2011 national food consumption survey. All meat-containing foods consumed were assigned to four food groups (n 502) on the basis of whether they contained red or white meat and whether they were processed or unprocessed. The remaining foods (n 2050) were assigned to twenty-nine food groups. Two-step and k-means cluster analyses were applied to derive dietary patterns. Nutrient intakes, plasma fatty acids and biomarkers of CVD and T2D were assessed. A total of four dietary patterns were derived. In comparison with the pattern with lower contributions from processed red meat, the dietary pattern with greater processed red meat intakes presented a poorer Alternate Healthy Eating Index (21·2 (sd 7·7)), a greater proportion of smokers (29 %) and lower plasma EPA (1·34 (sd 0·72) %) and DHA (2·21 (sd 0·84) %) levels (P<0·001). There were no differences in classical biomarkers of CVD and T2D, including serum cholesterol and insulin, across dietary patterns. This suggests that the consideration of processed red meat consumption as a risk factor for CVD and T2D may need to be re-assessed.

Impact of Sex Hormone Metabolism on the Vascular Effects of Menopausal Hormone Therapy in Cardiovascular Disease

PubMed Central

Masood, Durr-e-Nayab; Roach, Emir C.; Beauregard, Katie G.; Khalil, Raouf A.

2010-01-01

Epidemiological studies have shown that cardiovascular disease (CVD) is less common in pre-menopausal women (Pre-MW) compared to men of the same age or post-menopausal women (Post-MW), suggesting cardiovascular benefits of estrogen. Estrogen receptors (ERs) have been identified in the vasculature, and experimental studies have demonstrated vasodilator effects of estrogen/ER on the endothelium, vascular smooth muscle (VSM) and extracellular matrix. Several natural and synthetic estrogenic preparations have been developed for relief of menopausal vasomotor symptoms. However, whether menopausal hormone therapy (MHT) is beneficial in postmenopausal CVD remains controversial. Despite reports of vascular benefits of MHT from observational and experimental studies, randomized clinical trials (RCTs), such as the Heart and Estrogen/progestin Replacement Study (HERS) and the Women’s Health Initiative (WHI), have suggested that, contrary to expectations, MHT may increase the risk of CVD. These discrepancies could be due to age-related changes in sex hormone synthesis and metabolism, which would influence the effective dose of MHT and the sex hormone environment in Post-MW. Age-related changes in the vascular ER subtype, structure, expression, distribution, and post-ER signaling pathways in the endothelium and VSM, along with factors related to the design of RCTs, preexisting CVD condition, and structural changes in the blood vessels architecture have also been suggested as possible causes of MHT failure in CVD. Careful examination of these factors should help in identifying the causes of the changes in the vascular effects of estrogen with age. The sex hormone metabolic pathways, the active versus inactive estrogen metabolites, and their effects on vascular function, the mitochondria, the inflammatory process and angiogenesis should be further examined. Also, the genomic and non-genomic effects of estrogenic compounds should be viewed as integrated rather than discrete responses. The complex interactions between these factors highlight the importance of careful design of MHT RCTs, and the need of a more customized approach for each individual patient in order to enhance the vascular benefits of MHT in postmenopausal CVD. PMID:21189141

Improved functionality of graphene and carbon nanotube hybrid foam architecture by UV-ozone treatment

NASA Astrophysics Data System (ADS)

Wang, Wei; Ruiz, Isaac; Lee, Ilkeun; Zaera, Francisco; Ozkan, Mihrimah; Ozkan, Cengiz S.

2015-04-01

Optimization of the electrode/electrolyte double-layer interface is a key factor for improving electrode performance of aqueous electrolyte based supercapacitors (SCs). Here, we report the improved functionality of carbon materials via a non-invasive, high-throughput, and inexpensive UV generated ozone (UV-ozone) treatment. This process allows precise tuning of the graphene and carbon nanotube hybrid foam (GM) transitionally from ultrahydrophobic to hydrophilic within 60 s. The continuous tuning of surface energy can be controlled by simply varying the UV-ozone exposure time, while the ozone-oxidized carbon nanostructure maintains its integrity. Symmetric SCs based on the UV-ozone treated GM foam demonstrated enhanced rate performance. This technique can be readily applied to other CVD-grown carbonaceous materials by taking advantage of its ease of processing, low cost, scalability, and controllability.Optimization of the electrode/electrolyte double-layer interface is a key factor for improving electrode performance of aqueous electrolyte based supercapacitors (SCs). Here, we report the improved functionality of carbon materials via a non-invasive, high-throughput, and inexpensive UV generated ozone (UV-ozone) treatment. This process allows precise tuning of the graphene and carbon nanotube hybrid foam (GM) transitionally from ultrahydrophobic to hydrophilic within 60 s. The continuous tuning of surface energy can be controlled by simply varying the UV-ozone exposure time, while the ozone-oxidized carbon nanostructure maintains its integrity. Symmetric SCs based on the UV-ozone treated GM foam demonstrated enhanced rate performance. This technique can be readily applied to other CVD-grown carbonaceous materials by taking advantage of its ease of processing, low cost, scalability, and controllability. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr06795a

COACH trial: A randomized controlled trial of nurse practitioner/community health worker cardiovascular disease risk reduction in urban community health centers: Rationale and design

PubMed Central

Allen, Jerilyn K; Himmelfarb, Cheryl R Dennison; Szanton, Sarah L; Bone, Lee; Hill, Martha N; Levine, David M

2011-01-01

Background Despite well-publicized guidelines on the appropriate management of cardiovascular disease (CVD) and type 2 diabetes, implementation of risk-reducing practices remains poor. This paper describes the rationale and design of a randomized controlled clinical trial evaluating the effectiveness of a comprehensive program of CVD risk reduction delivered by nurse practitioner (NP)/community health worker (CHW) teams versus enhanced usual care in improving the proportion of patients in urban community health centers who achieve goal levels recommended by national guidelines for lipids, blood pressure, HbA1c and prescription of appropriate medications. Methods The COACH (Community Outreach and Cardiovascular Health) trial is a randomized controlled trial in which patients at federally-qualified community health centers were randomly assigned to one of two groups: comprehensive intensive management of CVD risk factors for one year by a NP/CHW team or an enhanced usual care control group. Results A total of 3899 patients were assessed for eligibility and 525 were randomized. Groups were comparable at baseline on sociodemographic and clinical characteristics with the exception of statistically significant differences in total cholesterol and hemoglobin A1c. Conclusions This study is a novel amalgam of multilevel interdisciplinary strategies to translate highly efficacious therapies to low-income federally-funded health centers that care for patients who carry a disproportionate burden of CVD, type 2 diabetes and uncontrolled CVD risk factors. The impact of such a community clinic-based intervention is potentially enormous. PMID:21241828

COACH trial: a randomized controlled trial of nurse practitioner/community health worker cardiovascular disease risk reduction in urban community health centers: rationale and design.

PubMed

Allen, Jerilyn K; Himmelfarb, Cheryl R Dennison; Szanton, Sarah L; Bone, Lee; Hill, Martha N; Levine, David M

2011-05-01

Despite well-publicized guidelines on the appropriate management of cardiovascular disease (CVD) and type 2 diabetes, implementation of risk-reducing practices remains poor. This paper describes the rationale and design of a randomized controlled clinical trial evaluating the effectiveness of a comprehensive program of CVD risk reduction delivered by nurse practitioner (NP)/community health worker (CHW) teams versus enhanced usual care in improving the proportion of patients in urban community health centers who achieve goal levels recommended by national guidelines for lipids, blood pressure, HbA1c and prescription of appropriate medications. The COACH (Community Outreach and Cardiovascular Health) trial is a randomized controlled trial in which patients at federally-qualified community health centers were randomly assigned to one of two groups: comprehensive intensive management of CVD risk factors for one year by a NP/CHW team or an enhanced usual care control group. A total of 3899 patients were assessed for eligibility and 525 were randomized. Groups were comparable at baseline on sociodemographic and clinical characteristics with the exception of statistically significant differences in total cholesterol and hemoglobin A1c. This study is a novel amalgam of multilevel interdisciplinary strategies to translate highly efficacious therapies to low-income federally-funded health centers that care for patients who carry a disproportionate burden of CVD, type 2 diabetes and uncontrolled CVD risk factors. The impact of such a community clinic-based intervention is potentially enormous. Copyright © 2011 Elsevier Inc. All rights reserved.

A study of the knowledge, attitudes, and practices (KAP) of the women referred to health centers for cardiovascular disease (CVDs) and their risk factors.

PubMed

Mazloomy, Seyed Said; Baghianimoghadam, Mohammad Hosein; Ehrampoush, Mohammad Hasan; Baghianimoghadam, Behnam; Mazidi, Maysam; Mozayan, Mohammad Reza

2014-01-01

Hypertension, dyslipidemia, and diabetes are established risk factors for cardiovascular disease (CVD) morbidity and mortality. In the past decade a general increase in CVD risk factors in the population aged 65 and older, along with suboptimal control rates, have occurred. In this descriptive, cross-sectional study, the authors describe the knowledge, attitudes, and practices (KAP) of Iranian females regarding risk factors for CVD, in an attempt to help with the development of strategies to control risk factors and CVD. Participants were 200 women ages 15-49 referred to health centers in Yazd, selected from four different centers. Data were gathered through a questionnaire consisting of demographics and questions related to KAP. The validity of the questionnaire was determined by a health education specialist, with its reliability determined by piloting and measuring the related Cronbach's alpha (Alpha = 0.720). Measuring knowledge of CVD on a scale of 0-20, the mean knowledge score was 10.203.91. More than 76% of the participants knew that CVD is preventable. Ninety-one percent liked exercising and believed that exercising would make them feel better. The average mean scores for attitudes of participants toward CVD were 30.31 ± 3.21 out of 36. The authors conclude that there is a need for enhancing mothers' general knowledge about the disease, because of the increasing rates of CVD in females. This will lead to improvements in attitude and practice. Furthermore, learning in groups of 12 can be a beneficial educational method.

The influence of pharmacy and pharmacist characteristics on the secondary prevention of cardiovascular disease.

PubMed

Puspitasari, Hanni Prihhastuti; Aslani, Parisa; Krass, Ines

2015-10-01

A range of extended/enhanced pharmacy services (EPS) are increasingly being offered in community pharmacies following a global paradigm shift in professional pharmacy practice from a product-oriented focus to a patient-centered approach. A number of pharmacy/pharmacist characteristics have been reported to influence EPS provision. To investigate the association between EPS provision and community pharmacists' support in CVD secondary prevention and to identify pharmacy/pharmacist characteristics which predict EPS provision and CVD support. Setting Australian community pharmacies. Mail surveys to 1350 randomly selected pharmacies, stratified by state/territory, exploring professional activities provided to clients with CVD, characteristics of pharmacies (including EPS provision), and pharmacist characteristics. The survey data were analyzed using univariate analyses and multiple linear regression analysis. The level of community pharmacists' CVD support, determined by summing respondents' score for seven CVD support-related activities, and the pharmacies' level of involvement in EPS provision, determined by summing respondents' score for four types of EPS. EPS provision was then used as an independent variable in the regression analysis of CVD support. A response rate of 15.8% (209/1320) was obtained after three waves of the survey. Pharmacy documentation, a private area, Quality Care Pharmacy Program accreditation, number of pharmacists, and pharmacists' resource adequacy were predictors of EPS provision (adjusted R2 = 0.299, p < 0.001). The provision of CVD support was predicted by EPS provision (β = 0.290, p < 0.001), pharmacists' frequent contacts with general practitioners (β = 0.298, p < 0.001), and pharmacy documentation (β = 0.134, p = 0.033). The regression model of CVD support explained 34.2% of the variation (p < 0.001). Community pharmacists could contribute to CVD secondary prevention if they had frequent contacts with general practitioners and worked in pharmacies with a higher level of involvement in EPS provision. Of all influencing factors, documentation was a predictor of both EPS provision and CVD support, indicating the importance of documentation in supporting the management of chronic conditions.

Surface modification for interaction study with bacteria and preosteoblast cells

NASA Astrophysics Data System (ADS)

Song, Qing

Surface modification plays a pivotal role in bioengineering. Polymer coatings can provide biocompatibility and biofunctionalities to biomaterials through surface modification. In this dissertation, initiated chemical vapor deposition (iCVD) was utilized to coat two-dimensional (2D) and three-dimensional (3D) substrates with differently charged polyelectrolytes in order to generate antimicrobial and osteocompatible biomaterials. ICVD is a modified CVD technique that enables surface modification in an all-dry condition without substrate damage and solvent contamination. The free-radical polymerization allows the vinyl polymers to conformally coat on various micro- and nano-structured substrates and maintains the delicate structure of the functional groups. The vapor deposition of polycations provided antimicrobial activity to planar and porous substrates through destroying the negatively charged bacterial membrane and brought about high contact-killing efficiency (99.99%) against Gram-positive Bacillus subtilis and Gram-negative Escherichia coli. Additionally, the polyampholytes synthesized by iCVD exhibited excellent antifouling performance against the adhesion of Gram-positive Listeria innocua and Gram-negative E. coli in phosphate buffered saline (PBS). Their antifouling activities were attributed to the electrostatic interaction and hydration layers that served as physical and energetic barriers to prevent bacterial adhesion. The contact-killing and antifouling polymers synthesized by iCVD can be applied to surface modification of food processing equipment and medical devices with the aim of reducing foodborne diseases and medical infections. Moreover, the charged polyelectrolyte modified 2D polystyrene surfaces displayed good osteocompatibility and enhanced osteogenesis of preosteoblast cells than the un-modified polystyrene surface. In order to promote osteoinduction of hydroxyapatite (HA) scaffolds, bioinspired polymer-controlled mineralization was conducted on the polyelectrolyte modified HA scaffolds. The mineralized scaffolds stimulated osteogenesis of preosteoblast cells compared with the control HA scaffolds. Therefore, the surface modification through vapor deposition of polyelectrolytes and polymer-controlled mineralization can improve osteoinduction of bone materials. In summary, the iCVD-mediated surface modification is a simple and promising approach to biofunctionalizing various structured substrates and generating antimicrobial and biocompatible biomaterials.

Fibrinogen concentration and its role in CVD risk in black South Africans--effect of urbanisation.

PubMed

Pieters, Marlien; de Maat, Moniek P M; Jerling, Johann C; Hoekstra, Tiny; Kruger, Annamarie

2011-09-01

The aim of this study was to investigate correlates of fibrinogen concentration in black South Africans, as well as its association with cardiovascular disease (CVD) risk and whether urbanisation influences this association. A total of 1,006 rural and 1,004 urban black South Africans from the PURE study were cross-sectionally analysed. The association of fibrinogen with CVD risk was determined by investigating the association of fibrinogen with other CVD risk markers as well as with predicted CVD risk using the Reynolds Risk score. The rural group had a significantly higher fibrinogen concentration than the urban group, despite higher levels of risk factors and increased predicted CVD risk in the urban group. Increased levels of CVD risk factors were, however, still associated with increased fibrinogen concentration. Fibrinogen correlated significantly, but weakly, with overall predicted CVD risk. This correlation was stronger in the urban than in the rural group. Multiple regression analysis showed that a smaller percentage of the variance in fibrinogen is explained by the traditional CVD risk factors in the rural than in the urban group. In conclusion, fibrinogen is weakly associated with CVD risk (predicted overall risk as well with individual risk factors) in black South Africans, and is related to the degree of urbanisation. Increased fibrinogen concentration, in black South Africans, especially in rural areas, is largely unexplained, and likely not strongly correlated with traditional CVD-related lifestyle and pathophysiological processes. This does, however, not exclude the possibility that once increased, the fibrinogen concentration contributes to future development of CVD.

History of preterm birth and subsequent cardiovascular disease: a systematic review.

PubMed

Robbins, Cheryl L; Hutchings, Yalonda; Dietz, Patricia M; Kuklina, Elena V; Callaghan, William M

2014-04-01

A history of preterm birth (PTB) may be an important lifetime risk factor for cardiovascular disease (CVD) in women. We identified all peer-reviewed journal articles that met study criteria (English language, human studies, female, and adults ≥19 years old), that were found in the PubMed/MEDLINE databases, and that were published between Jan. 1, 1995, and Sept. 17, 2012. We summarized 10 studies that assessed the association between having a history of PTB and subsequent CVD morbidity or death. Compared with women who had term deliveries, women with any history of PTB had increased risk of CVD morbidity (variously defined; adjusted hazard ratio [aHR] ranged from 1.2-2.9; 2 studies), ischemic heart disease (aHR, 1.3-2.1; 3 studies), stroke (aHR, 1.7; 1 study), and atherosclerosis (aHR, 4.1; 1 study). Four of 5 studies that examined death showed that women with a history of PTB have twice the risk of CVD death compared with women who had term births. Two studies reported statistically significant higher risk of CVD-related morbidity and death outcomes (variously defined) among women with ≥2 pregnancies that ended in PTBs compared with women who had at least 2 births but which ended in only 1 PTB. Future research is needed to understand the potential impact of enhanced monitoring of CVD risk factors in women with a history of PTB on risk of future CVD risk. Copyright © 2014 Mosby, Inc. All rights reserved.

CVD2014-A Database for Evaluating No-Reference Video Quality Assessment Algorithms.

PubMed

Nuutinen, Mikko; Virtanen, Toni; Vaahteranoksa, Mikko; Vuori, Tero; Oittinen, Pirkko; Hakkinen, Jukka

2016-07-01

In this paper, we present a new video database: CVD2014-Camera Video Database. In contrast to previous video databases, this database uses real cameras rather than introducing distortions via post-processing, which results in a complex distortion space in regard to the video acquisition process. CVD2014 contains a total of 234 videos that are recorded using 78 different cameras. Moreover, this database contains the observer-specific quality evaluation scores rather than only providing mean opinion scores. We have also collected open-ended quality descriptions that are provided by the observers. These descriptions were used to define the quality dimensions for the videos in CVD2014. The dimensions included sharpness, graininess, color balance, darkness, and jerkiness. At the end of this paper, a performance study of image and video quality algorithms for predicting the subjective video quality is reported. For this performance study, we proposed a new performance measure that accounts for observer variance. The performance study revealed that there is room for improvement regarding the video quality assessment algorithms. The CVD2014 video database has been made publicly available for the research community. All video sequences and corresponding subjective ratings can be obtained from the CVD2014 project page (http://www.helsinki.fi/psychology/groups/visualcognition/).

The Dependence of CNT Aerogel Synthesis on Sulfur-driven Catalyst Nucleation Processes and a Critical Catalyst Particle Mass Concentration.

PubMed

Hoecker, Christian; Smail, Fiona; Pick, Martin; Weller, Lee; Boies, Adam M

2017-11-06

The floating catalyst chemical vapor deposition (FC-CVD) process permits macro-scale assembly of nanoscale materials, enabling continuous production of carbon nanotube (CNT) aerogels. Despite the intensive research in the field, fundamental uncertainties remain regarding how catalyst particle dynamics within the system influence the CNT aerogel formation, thus limiting effective scale-up. While aerogel formation in FC-CVD reactors requires a catalyst (typically iron, Fe) and a promotor (typically sulfur, S), their synergistic roles are not fully understood. This paper presents a paradigm shift in the understanding of the role of S in the process with new experimental studies identifying that S lowers the nucleation barrier of the catalyst nanoparticles. Furthermore, CNT aerogel formation requires a critical threshold of Fe x C y  > 160 mg/m 3 , but is surprisingly independent of the initial catalyst diameter or number concentration. The robustness of the critical catalyst mass concentration principle is proved further by producing CNTs using alternative catalyst systems; Fe nanoparticles from a plasma spark generator and cobaltocene and nickelocene precursors. This finding provides evidence that low-cost and high throughput CNT aerogel routes may be achieved by decoupled and enhanced catalyst production and control, opening up new possibilities for large-scale CNT synthesis.

Charge multiplication effect in thin diamond films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Skukan, N., E-mail: nskukan@irb.hr; Grilj, V.; Sudić, I.

2016-07-25

Herein, we report on the enhanced sensitivity for the detection of charged particles in single crystal chemical vapour deposition (scCVD) diamond radiation detectors. The experimental results demonstrate charge multiplication in thin planar diamond membrane detectors, upon impact of 18 MeV O ions, under high electric field conditions. Avalanche multiplication is widely exploited in devices such as avalanche photo diodes, but has never before been reproducibly observed in intrinsic CVD diamond. Because enhanced sensitivity for charged particle detection is obtained for short charge drift lengths without dark counts, this effect could be further exploited in the development of sensors based on avalanchemore » multiplication and radiation detectors with extreme radiation hardness.« less

Chemical vapor deposition of mullite coatings

DOEpatents

Sarin, Vinod; Mulpuri, Rao

1998-01-01

This invention is directed to the creation of crystalline mullite coatings having uniform microstructure by chemical vapor deposition (CVD). The process comprises the steps of establishing a flow of reactants which will yield mullite in a CVD reactor, and depositing a crystalline coating from the reactant flow. The process will yield crystalline coatings which are dense and of uniform thickness.

Process stability and morphology optimization of very thick 4H-SiC epitaxial layers grown by chloride-based CVD

NASA Astrophysics Data System (ADS)

Yazdanfar, M.; Stenberg, P.; Booker, I. D.; Ivanov, I. G.; Kordina, O.; Pedersen, H.; Janzén, E.

2013-10-01

The development of a chemical vapor deposition (CVD) process for very thick silicon carbide (SiC) epitaxial layers suitable for high power devices is demonstrated by epitaxial growth of 200 μm thick, low doped 4H-SiC layers with excellent morphology at growth rates exceeding 100 μm/h. The process development was done in a hot wall CVD reactor without rotation using both SiCl4 and SiH4+HCl precursor approaches to chloride based growth chemistry. A C/Si ratio <1 and an optimized in-situ etch are shown to be the key parameters to achieve 200 μm thick, low doped epitaxial layers with excellent morphology.

Raman Enhancement and Photo-Bleaching of Organic Dyes in the Presence of Chemical Vapor Deposition-Grown Graphene.

PubMed

Weng, Jiaxin; Zhao, Shichao; Li, Zhiting; Ricardo, Karen B; Zhou, Feng; Kim, Hyojeong; Liu, Haitao

2017-10-19

Fluorescent organic dyes photobleach under intense light. Graphene has been shown to improve the photo-stability of organic dyes. In this paper, we investigated the Raman spectroscopy and photo-bleaching kinetics of dyes in the absence/presence of chemical vapor deposition (CVD)-grown graphene. We show that graphene enhances the Raman signal of a wide range of dyes. The photo-bleaching of the dyes was reduced when the dyes were in contact with graphene. In contrast, monolayer hexagonal boron nitride (h-BN) was much less effective in reducing the photo-bleaching rate of the dyes. We attribute the suppression of photo-bleaching to the energy or electron transfer from dye to graphene. The results highlight the potential of CVD graphene as a substrate for protecting and enhancing Raman response of organic dyes.

'I should have taken that further' - missed opportunities during cardiovascular risk assessment in patients with psoriasis in UK primary care settings: a mixed-methods study.

PubMed

Nelson, Pauline A; Kane, Karen; Chisholm, Anna; Pearce, Christina J; Keyworth, Christopher; Rutter, Martin K; Chew-Graham, Carolyn A; Griffiths, Christopher E M; Cordingley, Lis

2016-10-01

Unhealthy lifestyle is common in psoriasis, contributing to worsening disease and increased cardiovascular disease (CVD) risk. CVD risk communication should improve patients' understanding of risk and risk-reducing behaviours; however, the effectiveness of risk screening is debated and evaluation currently limited. To examine the process of assessing for and communicating about CVD risk in the context of psoriasis. Mixed-methods study in English general practices to (i) determine proportions of CVD risk factors among patients with psoriasis at risk assessment and (ii) examine patient and practitioner experiences of risk communication to identify salient 'process' issues. Audio recordings of consultations informed in-depth interviews with patients and practitioners using tape-assisted recall, analysed with framework analysis. Patients with psoriasis (n = 287) undergoing CVD risk assessment; 29 patients and 12 practitioners interviewed. A high proportion of patients had risk factor levels apparent at risk assessment above NICE recommendations: very high waist circumference (52%), obesity (35%), raised blood pressure (29%), smoking (18%) and excess alcohol consumption (18%). There was little evidence of personalized discussion about CVD risk and behaviour change support in consultations. Professionals reported a lack of training in behaviour change, while patients wanted to discuss CVD risk/risk reduction and believed practitioners to be influential in supporting lifestyle management. Despite high levels of risk factors identified, opportunities may be missed in consultations to support patients with psoriasis to understand CVD risk/risk reduction. Practitioners need training in behaviour change techniques to capitalize on 'teachable moments' and increase the effectiveness of risk screening. © 2015 The Authors. Health Expectations Published by John Wiley & Sons Ltd.

Injection doping of ultrathin microcrystalline silicon films prepared by CC-CVD

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koynov, S.; Grebner, S.; Schwarz, R.

1997-07-01

Recently, the authors have proposed a cyclic method, referred to as Closed Chamber CVD (CC-CVD), for the preparation of {micro}c-Si films of high crystalline fraction at increased deposition rates. In this work, they first report new process conditions of CC-CVD, which result in growth of highly crystalline films with a sharp interface on a foreign substrate. Then these conditions are further used together with a pulsed injection of B{sub 2}H{sub 6} in an appropriate moment of each cycle, so that the disturbance of the crystallization process is prevented. A series of ultrathin {micro}c-Si films, doped by this technique, is characterizedmore » by conductivity measurements, SEM, Raman Scattering, optical transmission and UV reflection. A strong reduction of the transient interface layer is achieved and conductivity as high as 2 S/cm with an activation energy of 27 meV is reached.« less

Challenges of developing a cardiovascular risk calculator for patients with rheumatoid arthritis.

PubMed

Crowson, Cynthia S; Rollefstad, Silvia; Kitas, George D; van Riel, Piet L C M; Gabriel, Sherine E; Semb, Anne Grete

2017-01-01

Cardiovascular disease (CVD) risk calculators designed for use in the general population do not accurately predict the risk of CVD among patients with rheumatoid arthritis (RA), who are at increased risk of CVD. The process of developing risk prediction models involves numerous issues. Our goal was to develop a CVD risk calculator for patients with RA. Thirteen cohorts of patients with RA originating from 10 different countries (UK, Norway, Netherlands, USA, Sweden, Greece, South Africa, Spain, Canada and Mexico) were combined. CVD risk factors and RA characteristics at baseline, in addition to information on CVD outcomes were collected. Cox models were used to develop a CVD risk calculator, considering traditional CVD risk factors and RA characteristics. Model performance was assessed using measures of discrimination and calibration with 10-fold cross-validation. A total of 5638 RA patients without prior CVD were included (mean age: 55 [SD: 14] years, 76% female). During a mean follow-up of 5.8 years (30139 person years), 389 patients developed a CVD event. Event rates varied between cohorts, necessitating inclusion of high and low risk strata in the models. The multivariable analyses revealed 2 risk prediction models including either a disease activity score including a 28 joint count and erythrocyte sedimentation rate (DAS28ESR) or a health assessment questionnaire (HAQ) along with age, sex, presence of hypertension, current smoking and ratio of total cholesterol to high-density lipoprotein cholesterol. Unfortunately, performance of these models was similar to general population CVD risk calculators. Efforts to develop a specific CVD risk calculator for patients with RA yielded 2 potential models including RA disease characteristics, but neither demonstrated improved performance compared to risk calculators designed for use in the general population. Challenges encountered and lessons learned are discussed in detail.

Patterns of population differentiation of candidate genes for cardiovascular disease.

PubMed

Kullo, Iftikhar J; Ding, Keyue

2007-07-12

The basis for ethnic differences in cardiovascular disease (CVD) susceptibility is not fully understood. We investigated patterns of population differentiation (FST) of a set of genes in etiologic pathways of CVD among 3 ethnic groups: Yoruba in Nigeria (YRI), Utah residents with European ancestry (CEU), and Han Chinese (CHB) + Japanese (JPT). We identified 37 pathways implicated in CVD based on the PANTHER classification and 416 genes in these pathways were further studied; these genes belonged to 6 biological processes (apoptosis, blood circulation and gas exchange, blood clotting, homeostasis, immune response, and lipoprotein metabolism). Genotype data were obtained from the HapMap database. We calculated FST for 15,559 common SNPs (minor allele frequency > or = 0.10 in at least one population) in genes that co-segregated among the populations, as well as an average-weighted FST for each gene. SNPs were classified as putatively functional (non-synonymous and untranslated regions) or non-functional (intronic and synonymous sites). Mean FST values for common putatively functional variants were significantly higher than FST values for nonfunctional variants. A significant variation in FST was also seen based on biological processes; the processes of 'apoptosis' and 'lipoprotein metabolism' showed an excess of genes with high FST. Thus, putative functional SNPs in genes in etiologic pathways for CVD show greater population differentiation than non-functional SNPs and a significant variance of FST values was noted among pairwise population comparisons for different biological processes. These results suggest a possible basis for varying susceptibility to CVD among ethnic groups.

Making Ceramic Fibers By Chemical Vapor

NASA Technical Reports Server (NTRS)

Revankar, Vithal V. S.; Hlavacek, Vladimir

1994-01-01

Research and development of fabrication techniques for chemical vapor deposition (CVD) of ceramic fibers presented in two reports. Fibers of SiC, TiB2, TiC, B4C, and CrB2 intended for use as reinforcements in metal-matrix composite materials. CVD offers important advantages over other processes: fibers purer and stronger and processed at temperatures below melting points of constituent materials.

Advances in the Development of a WCl6 CVD System for Coating UO2 Powders with Tungsten

NASA Technical Reports Server (NTRS)

Mireles, Omar R.; Tieman, Alyssa; Broadway, Jeramie; Hickman, Robert

2013-01-01

Demonstrated viability and utilization of: a) Fluidized powder bed. b) WCl6 CVD process. c) Coated spherical particles with tungsten. The highly corrosive nature of the WCl6 solid reagent limits material of construction. Indications that identifying optimized process variables with require substantial effort and will likely vary with changes in fuel requirements.

Large Area CVD MoS2 RF transistors with GHz performance

NASA Astrophysics Data System (ADS)

Nagavalli Yogeesh, Maruthi; Sanne, Atresh; Park, Saungeun; Akinwade, Deji; Banerjee, Sanjay

Molybdenum disulfide (MoS2) is a 2D semiconductor in the family of transition metal dichalcogenides (TMDs). Its single layer direct bandgap of 1.8 eV allows for high ION/IOFF metal-oxide semiconducting field-effect transistors (FETs). More relevant for radio frequency (RF) wireless applications, theoretical studies predict MoS2 to have saturation velocities, vsat >3×106 cm/s. Facilitated by cm-scale CVD MoS2, here we design and fabricate both top-gated and embedded gate short channel MoS2 RF transistors, and provide a systematic comparison of channel length scaling, extrinsic doping from oxygen-deficient dielectrics, and a gate-first gate-last process flow. The intrinsic fT (fmax) obtained from the embedded gate transistors shows 3X (2X) improvement over top-gated CVD MoS2 RF FETs, and the largest high-field saturation velocity, vsat = 1.88 ×106 cm/s, in MoS2 reported so far. The gate-first approach, offers enhancement mode operation, ION/IOFF ratio of 10, 8< and the highest reported transconductance (gm) of 70 μS/ μm. By manipulating the interfacial oxygen vacancies in atomic layer deposited (ALD) HfO2-x we are able to achieve 2X current density over stoichiometric Al2O3. We demonstrate a common-source (CS) amplifier with voltage gain of 14 dB and an active frequency mixer with conversion gain of -15 dB. Our results of gigahertz frequency performance as well as analog circuit operation show that large area CVD MoS2 may be suitable for industrial-scale electronic applications.

Personalized Weight Management Interventions for Cardiovascular Risk Reduction: A Viable Option for African-American Women.

PubMed

Franklin, Nina C; Arena, Ross

2016-01-01

Obesity is an independent contributor to cardiovascular disease (CVD) and a major driving force behind racial/ethnic and gender disparities in risk. Due to a multitude of interrelating factors (i.e., personal, social, cultural, economic and environmental), African-American (AA) women are disproportionately obese and twice as likely to succumb to CVD, yet they are significantly underrepresented in behavioral weight management interventions. In this selective review we highlight components of the limited interventions shown to enhance weight loss outcomes in this population and make a case for leveraging Web-based technology and artificial intelligence techniques to deliver personalized programs aimed at obesity treatment and CVD risk reduction. Although many of the approaches discussed are generally applicable across populations burdened by disparate rates of obesity and CVD, we specifically focus on AA women due to the disproportionate impact of these non-communicable diseases and the general paucity of interventions targeted to this high-risk group. Copyright © 2016 Elsevier Inc. All rights reserved.

Improving Medication Adherence in Cardiometabolic Disease

PubMed Central

Ferdinand, Keith C.; Senatore, Fortunato Fred; Clayton-Jeter, Helene; Cryer, Dennis R.; Lewin, John C.; Nasser, Samar A.; Fiuzat, Mona; Califf, Robert M.

2017-01-01

Medication nonadherence, a major problem in cardiovascular disease (CVD), contributes yearly to approximately 125,000 preventable deaths, which is partly attributable to only about one-half of CVD patients consistently taking prescribed life-saving medications. Current interest has focused on how labeling and education influence adherence. This paper summarizes the scope of CVD nonadherence, describes key U.S. Food and Drug Administration initiatives, and identifies potential targets for improvement. We describe key adherence factors, methods, and technological applications for simplifying regimens and enhancing adherence, and 4 areas where additional collaborative research and implementation involving the regulatory system and clinical community could substantially reduce nonadherence: 1) identifying monitoring methods; 2) improving the evidence base to better understand adherence; 3) developing patient/health provider team-based engagement strategies; and 4) alleviating health disparities. Alignment of U.S. Food and Drug Administration approaches to dissemination of information about appropriate use with clinical practice could improve adherence, and thereby reduce CVD death and disability. PMID:28126162

Triglyceride-rich lipoproteins as a causal factor for cardiovascular disease

PubMed Central

Toth, Peter P

2016-01-01

Approximately 25% of US adults are estimated to have hypertriglyceridemia (triglyceride [TG] level ≥150 mg/dL [≥1.7 mmol/L]). Elevated TG levels are associated with increased cardiovascular disease (CVD) risk, and severe hypertriglyceridemia (TG levels ≥500 mg/dL [≥5.6 mmol/L]) is a well-established risk factor for acute pancreatitis. Plasma TG levels correspond to the sum of the TG content in TG-rich lipoproteins (TRLs; ie, very low-density lipoproteins plus chylomicrons) and their remnants. There remains some uncertainty regarding the direct causal role of TRLs in the progression of atherosclerosis and CVD, with cardiovascular outcome studies of TG-lowering agents, to date, having produced inconsistent results. Although low-density lipoprotein cholesterol (LDL-C) remains the primary treatment target to reduce CVD risk, a number of large-scale epidemiological studies have shown that elevated TG levels are independently associated with increased incidence of cardiovascular events, even in patients treated effectively with statins. Genetic studies have further clarified the causal association between TRLs and CVD. Variants in several key genes involved in TRL metabolism are strongly associated with CVD risk, with the strength of a variant’s effect on TG levels correlating with the magnitude of the variant’s effect on CVD. TRLs are thought to contribute to the progression of atherosclerosis and CVD via a number of direct and indirect mechanisms. They directly contribute to intimal cholesterol deposition and are also involved in the activation and enhancement of several proinflammatory, proapoptotic, and procoagulant pathways. Evidence suggests that non-high-density lipoprotein cholesterol, the sum of the total cholesterol carried by atherogenic lipoproteins (including LDL, TRL, and TRL remnants), provides a better indication of CVD risk than LDL-C, particularly in patients with hypertriglyceridemia. This article aims to provide an overview of the available epidemiological, clinical, and genetic evidence relating to the atherogenicity of TRLs and their role in the progression of CVD. PMID:27226718

Projection of temperature-related mortality due to cardiovascular disease in beijing under different climate change, population, and adaptation scenarios.

PubMed

Zhang, Boya; Li, Guoxing; Ma, Yue; Pan, Xiaochuan

2018-04-01

Human health faces unprecedented challenges caused by climate change. Thus, studies of the effect of temperature change on total mortality have been conducted in numerous countries. However, few of those studies focused on temperature-related mortality due to cardiovascular disease (CVD) or considered future population changes and adaptation to climate change. We present herein a projection of temperature-related mortality due to CVD under different climate change, population, and adaptation scenarios in Beijing, a megacity in China. To this end, 19 global circulation models (GCMs), 3 representative concentration pathways (RCPs), 3 socioeconomic pathways, together with generalized linear models and distributed lag non-linear models, were used to project future temperature-related CVD mortality during periods centered around the years 2050 and 2070. The number of temperature-related CVD deaths in Beijing is projected to increase by 3.5-10.2% under different RCP scenarios compared with that during the baseline period. Using the same GCM, the future daily maximum temperatures projected using the RCP2.6, RCP4.5, and RCP8.5 scenarios showed a gradually increasing trend. When population change is considered, the annual rate of increase in temperature-related CVD deaths was up to fivefold greater than that under no-population-change scenarios. The decrease in the number of cold-related deaths did not compensate for the increase in that of heat-related deaths, leading to a general increase in the number of temperature-related deaths due to CVD in Beijing. In addition, adaptation to climate change may enhance rather than ameliorate the effect of climate change, as the increase in cold-related CVD mortality greater than the decrease in heat-related CVD mortality in the adaptation scenarios will result in an increase in the total number of temperature-related CVD mortalities. Copyright © 2018 Elsevier Inc. All rights reserved.

Process in manufacturing high efficiency AlGaAs/GaAs solar cells by MO-CVD

NASA Technical Reports Server (NTRS)

Yeh, Y. C. M.; Chang, K. I.; Tandon, J.

1984-01-01

Manufacturing technology for mass producing high efficiency GaAs solar cells is discussed. A progress using a high throughput MO-CVD reactor to produce high efficiency GaAs solar cells is discussed. Thickness and doping concentration uniformity of metal oxide chemical vapor deposition (MO-CVD) GaAs and AlGaAs layer growth are discussed. In addition, new tooling designs are given which increase the throughput of solar cell processing. To date, 2cm x 2cm AlGaAs/GaAs solar cells with efficiency up to 16.5% were produced. In order to meet throughput goals for mass producing GaAs solar cells, a large MO-CVD system (Cambridge Instrument Model MR-200) with a susceptor which was initially capable of processing 20 wafers (up to 75 mm diameter) during a single growth run was installed. In the MR-200, the sequencing of the gases and the heating power are controlled by a microprocessor-based programmable control console. Hence, operator errors can be reduced, leading to a more reproducible production sequence.

Enhancing the oxidation resistance of graphite by applying an SiC coat with crack healing at an elevated temperature

NASA Astrophysics Data System (ADS)

Park, Jae-Won; Kim, Eung-Seon; Kim, Jae-Un; Kim, Yootaek; Windes, William E.

2016-08-01

The potential of reducing the oxidation of the supporting graphite components during normal and/or accident conditions in the Very High Temperature Reactor (VHTR) design has been studied. In this work efforts have been made to slow the oxidation process of the graphite with a thin SiC coating (∼ 10 μm). Upon heating at ≥ 1173 K in air, the spallations and cracks were formed in the dense columnar structured SiC coating layer grown on the graphite with a functionally gradient electron beam physical vapor deposition (EB-PVD. In accordance with the formations of these defects, the sample was vigorously oxidized, leaving only the SiC coating layer. Then, efforts were made to heal the surface defects using additional EB-PVD with ion beam bombardment and chemical vapor deposition (CVD). The EB-PVD did not effectively heal the cracks. But, the CVD was more appropriate for crack healing, likely due to its excellent crack line filling capability with a high density and high aspect ratio. It took ∼ 34 min for the 20% weight loss of the CVD crack healed sample in the oxidation test with annealing at 1173 K, while it took ∼ 8 min for the EB-PVD coated sample, which means it took ∼4 times longer at 1173 K for the same weight reduction in this experimental set-up.

Intervention fidelity for a complex behaviour change intervention in community pharmacy addressing cardiovascular disease risk.

PubMed

McNamara, K P; O'Reilly, S L; George, J; Peterson, G M; Jackson, S L; Duncan, G; Howarth, H; Dunbar, J A

2015-12-01

Delivery of cardiovascular disease (CVD) prevention programs by community pharmacists appears effective and enhances health service access. However, their capacity to implement complex behavioural change processes during patient counselling remains largely unexplored. This study aims to determine intervention fidelity by pharmacists for behavioural components of a complex educational intervention for CVD prevention. After receiving training to improve lifestyle and medicines adherence, pharmacists recruited 70 patients aged 50-74 years without established CVD, and taking antihypertensive or lipid lowering therapy. Patients received five counselling sessions, each at monthly intervals. Researchers assessed biomedical and behavioural risk factors at baseline and six months. Pharmacists documented key outcomes from counselling after each session. Most patients (86%) reported suboptimal cardiovascular diets, 41% reported suboptimal medicines adherence, and 39% were physically inactive. Of those advised to complete the intervention, 85% attended all five sessions. Pharmacists achieved patient agreement with most recommended goals for behaviour change, and overwhelmingly translated goals into practical behavioural strategies. Barriers to changing behaviours were regularly documented, and pharmacists reported most behavioural strategies as having had some success. Meaningful improvements to health behaviours were observed post-intervention. Findings support further exploration of pharmacists' potential roles for delivering interventions with complex behaviour change requirements. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Mindfulness and Cardiovascular Disease Risk: State of the Evidence, Plausible Mechanisms, and Theoretical Framework.

PubMed

Loucks, Eric B; Schuman-Olivier, Zev; Britton, Willoughby B; Fresco, David M; Desbordes, Gaelle; Brewer, Judson A; Fulwiler, Carl

2015-12-01

The purpose of this review is to provide (1) a synopsis on relations of mindfulness with cardiovascular disease (CVD) and major CVD risk factors, and (2) an initial consensus-based overview of mechanisms and theoretical framework by which mindfulness might influence CVD. Initial evidence, often of limited methodological quality, suggests possible impacts of mindfulness on CVD risk factors including physical activity, smoking, diet, obesity, blood pressure, and diabetes regulation. Plausible mechanisms include (1) improved attention control (e.g., ability to hold attention on experiences related to CVD risk, such as smoking, diet, physical activity, and medication adherence), (2) emotion regulation (e.g., improved stress response, self-efficacy, and skills to manage craving for cigarettes, palatable foods, and sedentary activities), and (3) self-awareness (e.g., self-referential processing and awareness of physical sensations due to CVD risk factors). Understanding mechanisms and theoretical framework should improve etiologic knowledge, providing customized mindfulness intervention targets that could enable greater mindfulness intervention efficacy.

Mindfulness and Cardiovascular Disease Risk: State of the Evidence, Plausible Mechanisms, and Theoretical Framework

PubMed Central

Schuman-Olivier, Zev; Britton, Willoughby B.; Fresco, David M.; Desbordes, Gaelle; Brewer, Judson A.; Fulwiler, Carl

2016-01-01

The purpose of this review is to provide (1) a synopsis on relations of mindfulness with cardiovascular disease (CVD) and major CVD risk factors, and (2) an initial consensus-based overview of mechanisms and theoretical framework by which mindfulness might influence CVD. Initial evidence, often of limited methodological quality, suggests possible impacts of mindfulness on CVD risk factors including physical activity, smoking, diet, obesity, blood pressure, and diabetes regulation. Plausible mechanisms include (1) improved attention control (e.g., ability to hold attention on experiences related to CVD risk, such as smoking, diet, physical activity, and medication adherence), (2) emotion regulation (e.g., improved stress response, self-efficacy, and skills to manage craving for cigarettes, palatable foods, and sedentary activities), and (3) self-awareness (e.g., self-referential processing and awareness of physical sensations due to CVD risk factors). Understanding mechanisms and theoretical framework should improve etiologic knowledge, providing customized mindfulness intervention targets that could enable greater mindfulness intervention efficacy. PMID:26482755

Observation of twinning in diamond CVD films

NASA Astrophysics Data System (ADS)

Marciniak, W.; Fabisiak, K.; Orzeszko, S.; Rozploch, F.

1992-10-01

Diamond particles prepared by dc-glow-discharge enhanced HF-CVD hybrid method, from a mixture of acetone vapor and hydrogen gas have been examined by TEM, RHEED and dark field method of observation. Results suggest the presence of twinned diamond particles, which can be reconstructed by a sequence of twinning operations. Contrary to the 'stick model' of the lattice, very common five-fold symmetry of diamond microcrystals may be obtained by applying a number of edge dislocations rather than the continuous deformation of many tetrahedral C-C bonds.

Prevalence of Refractive Errors in Students with and without Color Vision Deficiency

PubMed Central

Ostadimoghaddam, Hadi; Yekta, Abbas Ali; Heravian, Javad; Azimi, Abbas; Hosseini, Seyed Mahdi Ahmadi; Vatandoust, Sakineh; Sharifi, Fatemeh; Abolbashari, Fereshteh

2014-01-01

Purpose: To evaluate refractive errors in school age children with color vision deficiency (CVD) and those with normal color vision (NCV) in order to make a better understanding of the emmetropization process. Methods: A total of 4,400 primary school students aged 7–12 years were screened for color vision using Ishihara pseudoisochromatic color vision plate sets. Of these, 160 (3.6%) students had CVD. A total of 400 age- and sex-matched students with NCV were selected as controls. Refractive status was evaluated using objective cyclorefraction. Results: The CVD group included 136 male (85%) and 24 female (15%) subjects with mean age of 10.1 ± 1.8 years. The NCV group comprised of 336 male (84%) and 64 female (16%) subjects with mean age of 10.5 ± 1.2 years. The prevalence of myopia (7.7% vs. 13.9%, P < 0.001) and hyperopia (41% vs. 57.4%, P = 0.03) was significantly lower in the CVD group. Furthermore, subjects with CVD subjects demonstrated a lower magnitude of refractive errors as compared to the CVD group (mean refractive error: +0.54 ± 0.19 D versus + 0.74 ± 1.12 D, P < 0.001). Conclusion: Although the lower prevalence of myopia in subjects with CVD group supports the role of longitudinal chromatic aberration in the development of refractive errors; the lower prevalence of hyperopia in this group is an opposing finding. Myopia is a multifactorial disorder and longitudinal chromatic aberration is not the only factor influencing the emmetropization process. PMID:25709775

The place of Ruscus extract, hesperidin methyl chalcone, and vitamin C in the management of chronic venous disease.

PubMed

Jawien, Arkadiusz; Bouskela, Eliete; Allaert, François A; Nicolaïdes, Andrew N

2017-02-01

Despite continuous improvement in our knowledge and management of chronic venous disease (CVD), certain areas, such as the role of muscarinic receptors in the pathology and treatment of CVD, remain unexplored. The symposium "The place of Ruscus extract, hesperidin methyl chalcone, and vitamin C in the management of CVD", held at the Annual Meeting of the European Venous Forum on 7-9 July 2016 in London, presented an update on the pathophysiology of CVD and highlighted how the combination of Ruscus extract, hesperidin methyl chalcone, and vitamin C (Ruscus/HMC/VitC; Cyclo 3® Fort), may counteract the deleterious processes underlying CVD. The data presented during this symposium are reported here. The pathophysiology of CVD is driven by a complex process involving numerous factors, with the two key players being venous hypertension and the inflammatory response. The cascade of reactions induced by disturbed venous flow, inflammation, and tissue alterations results in the early appearance of symptoms and progressive development of clinical signs of disease. Previous studies have shown that Ruscus extract acts at three levels: on the veins, capillaries and lymphatics, and has anti-inflammatory properties. A series of recent experiments has shed new light on the mechanism of action of the combination of Ruscus/HMC/VitC. The efficacy of Ruscus/HMC/VitC in CVD is supported by clinical studies, while two meta-analyses have confirmed a significant decrease of several symptoms and ankle circumference in response to treatment with this agent, leading to the conclusion that Ruscus/HMC/VitC deserves a Grade A rating.

Silicon-on-Insulator Pin Diodes.

DTIC Science & Technology

1987-12-01

Thin (0.5 Micron) Silicon-on-Oxidized Silicon Fig. 2.8 SEM Photographs of CVD Silicon Dioxide on Aluminum 28 After 1500 0 C Anneal in Oxygen...silicon nitride over the silicon dioxide encapsu- -9- lation layer and by depositing the silicon dioxide with a plasma CVD process which uses N20 as...relief via thermal expansion matching varies lin- -27- A B Figure 2.8: SEM Photographs of CVD Silicon Dioxide on Aluminum after 15000 C Anneal in Oxygen

Study of the triton-burnup process in different JET scenarios using neutron monitor based on CVD diamond

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nemtsev, G., E-mail: g.nemtsev@iterrf.ru; Amosov, V.; Meshchaninov, S.

We present the results of analysis of triton burn-up process using the data from diamond detector. Neutron monitor based on CVD diamond was installed in JET torus hall close to the plasma center. We measure the part of 14 MeV neutrons in scenarios where plasma current varies in a range of 1-3 MA. In this experiment diamond neutron monitor was also able to detect strong gamma bursts produced by runaway electrons arising during the disruptions. We can conclude that CVD diamond detector will contribute to the study of fast particles confinement and help predict the disruption events in future tokamaks.

Chemical vapor deposition fluid flow simulation modelling tool

NASA Technical Reports Server (NTRS)

Bullister, Edward T.

1992-01-01

Accurate numerical simulation of chemical vapor deposition (CVD) processes requires a general purpose computational fluid dynamics package combined with specialized capabilities for high temperature chemistry. In this report, we describe the implementation of these specialized capabilities in the spectral element code NEKTON. The thermal expansion of the gases involved is shown to be accurately approximated by the low Mach number perturbation expansion of the incompressible Navier-Stokes equations. The radiative heat transfer between multiple interacting radiating surfaces is shown to be tractable using the method of Gebhart. The disparate rates of reaction and diffusion in CVD processes are calculated via a point-implicit time integration scheme. We demonstrate the use above capabilities on prototypical CVD applications.

Superhydrophobic Copper Surfaces with Anticorrosion Properties Fabricated by Solventless CVD Methods.

PubMed

Vilaró, Ignasi; Yagüe, Jose L; Borrós, Salvador

2017-01-11

Due to continuous miniaturization and increasing number of electrical components in electronics, copper interconnections have become critical for the design of 3D integrated circuits. However, corrosion attack on the copper metal can affect the electronic performance of the material. Superhydrophobic coatings are a commonly used strategy to prevent this undesired effect. In this work, a solventless two-steps process was developed to fabricate superhydrophobic copper surfaces using chemical vapor deposition (CVD) methods. The superhydrophobic state was achieved through the design of a hierarchical structure, combining micro-/nanoscale domains. In the first step, O 2 - and Ar-plasma etchings were performed on the copper substrate to generate microroughness. Afterward, a conformal copolymer, 1H,1H,2H,2H-perfluorodecyl acrylate-ethylene glycol diacrylate [p(PFDA-co-EGDA)], was deposited on top of the metal via initiated CVD (iCVD) to lower the surface energy of the surface. The copolymer topography exhibited a very characteristic and unique nanoworm-like structure. The combination of the nanofeatures of the polymer with the microroughness of the copper led to achievement of the superhydrophobic state. AFM, SEM, and XPS were used to characterize the evolution in topography and chemical composition during the CVD processes. The modified copper showed water contact angles as high as 163° and hysteresis as low as 1°. The coating withstood exposure to aggressive media for extended periods of time. Tafel analysis was used to compare the corrosion rates between bare and modified copper. Results indicated that iCVD-coated copper corrodes 3 orders of magnitude slower than untreated copper. The surface modification process yielded repeatable and robust superhydrophobic coatings with remarkable anticorrosion properties.

Transport Imaging in the One Dimensional Limit

DTIC Science & Technology

2006-06-01

Spatial luminescence from single bottom-up GaN and ZnO nanowires deposited by metal initiated metal -organic CVD on Au and SiO2 substrates is imaged. CL...this thesis were deposited by metal initiated metal -organic CVD on Au and SiO2 substrates . The process was carried out with different reagents in...are reported. Spatial luminescence from single bottom-up GaN and ZnO nanowires deposited by metal initiated metal -organic CVD on Au and SiO2

Low temperature growth of diamond films on optical fibers using Linear Antenna CVD system

NASA Astrophysics Data System (ADS)

Ficek, M.; Drijkoningen, S.; Karczewski, J.; Bogdanowicz, R.; Haenen, K.

2016-01-01

It is not trivial to achieve a good quality diamond-coated fibre interface due to a large difference in the properties and composition of the diamond films (or use coating even) and the optical fibre material, i.e. fused silica. One of the biggest problems is the high temperature during the deposition which influences the optical fibre or optical fibre sensor structure (e.g. long-period gratings (LPG)). The greatest advantage of a linear antenna microwave plasma enhanced chemical vapor deposition system (LA MW CVD) is the fact that it allows to grow the diamond layers at low temperature (below 300°C) [1]. High quality nanocrystalline diamond (NCD) thin films with thicknesses ranging from 70 nm to 150 nm, were deposited on silicon, glass and optical fibre substrates [2]. Substrates pretreatment by dip-coating and spin coating process with a dispersion consisting of detonation nanodiamond (DND) in dimethyl sulfoxide (DMSO) with polyvinyl alcohol (PVA) has been applied. During the deposition process the continuous mode of operation of the LA MW CVD system was used, which produces a continuous wave at a maximum power of 1.9 kW (in each antenna). Diamond films on optical fibres were obtained at temperatures below 350°C, providing a clear improvement of results compared to our earlier work [3]. The samples were characterized by scanning electron microscopy (SEM) imaging to investigate the morphology of the nanocrystalline diamond films. The film growth rate, film thickness, and optical properties in the VIS-NIR range, i.e. refractive index and extinction coefficient will be discussed based on measurements on reference quartz plates by using spectroscopic ellipsometry (SE).

The role of NH3 and hydrocarbon mixtures in GaN pseudo-halide CVD: a quantum chemical study.

PubMed

Gadzhiev, Oleg B; Sennikov, Peter G; Petrov, Alexander I; Kachel, Krzysztof; Golka, Sebastian; Gogova, Daniela; Siche, Dietmar

2014-11-01

The prospects of a control for a novel gallium nitride pseudo-halide vapor phase epitaxy (PHVPE) with HCN were thoroughly analyzed for hydrocarbons-NH3-Ga gas phase on the basis of quantum chemical investigation with DFT (B3LYP, B3LYP with D3 empirical correction on dispersion interaction) and ab-initio (CASSCF, coupled clusters, and multireference configuration interaction including MRCI+Q) methods. The computational screening of reactions for different hydrocarbons (CH4, C2H6, C3H8, C2H4, and C2H2) as readily available carbon precursors for HCN formation, potential chemical transport agents, and for controlled carbon doping of deposited GaN was carried out with the B3LYP method in conjunction with basis sets up to aug-cc-pVTZ. The gas phase intermediates for the reactions in the Ga-hydrocarbon systems were predicted at different theory levels. The located π-complexes Ga…C2H2 and Ga…C2H4 were studied to determine a probable catalytic activity in reactions with NH3. A limited influence of the carbon-containing atmosphere was exhibited for the carbon doping of GaN crystal in the conventional GaN chemical vapor deposition (CVD) process with hydrocarbons injected in the gas phase. Our results provide a basis for experimental studies of GaN crystal growth with C2H4 and C2H2 as auxiliary carbon reagents for the Ga-NH3 and Ga-C-NH3 CVD systems and prerequisites for reactor design to enhance and control the PHVPE process through the HCN synthesis.

Single liquid source plasma-enhanced metalorganic chemical vapor deposition of high-quality YBa2Cu3O(7-x) thin films

NASA Technical Reports Server (NTRS)

Zhang, Jiming; Gardiner, Robin A.; Kirlin, Peter S.; Boerstler, Robert W.; Steinbeck, John

1992-01-01

High quality YBa2Cu3O(7-x) films were grown in-situ on LaAlO3 (100) by a novel single liquid source plasma-enhanced metalorganic chemical vapor deposition process. The metalorganic complexes M(thd) (sub n), (thd = 2,2,6,6-tetramethyl-3,5-heptanedionate; M = Y, Ba, Cu) were dissolved in an organic solution and injected into a vaporizer immediately upstream of the reactor inlet. The single liquid source technique dramatically simplifies current CVD processing and can significantly improve the process reproducibility. X-ray diffraction measurements indicated that single phase, highly c-axis oriented YBa2Cu3O(7-x) was formed in-situ at substrate temperature 680 C. The as-deposited films exhibited a mirror-like surface, had transition temperature T(sub cO) approximately equal to 89 K, Delta T(sub c) less than 1 K, and Jc (77 K) = 10(exp 6) A/sq cm.

Patterns of population differentiation of candidate genes for cardiovascular disease

PubMed Central

Kullo, Iftikhar J; Ding, Keyue

2007-01-01

Background The basis for ethnic differences in cardiovascular disease (CVD) susceptibility is not fully understood. We investigated patterns of population differentiation (FST) of a set of genes in etiologic pathways of CVD among 3 ethnic groups: Yoruba in Nigeria (YRI), Utah residents with European ancestry (CEU), and Han Chinese (CHB) + Japanese (JPT). We identified 37 pathways implicated in CVD based on the PANTHER classification and 416 genes in these pathways were further studied; these genes belonged to 6 biological processes (apoptosis, blood circulation and gas exchange, blood clotting, homeostasis, immune response, and lipoprotein metabolism). Genotype data were obtained from the HapMap database. Results We calculated FST for 15,559 common SNPs (minor allele frequency ≥ 0.10 in at least one population) in genes that co-segregated among the populations, as well as an average-weighted FST for each gene. SNPs were classified as putatively functional (non-synonymous and untranslated regions) or non-functional (intronic and synonymous sites). Mean FST values for common putatively functional variants were significantly higher than FST values for nonfunctional variants. A significant variation in FST was also seen based on biological processes; the processes of 'apoptosis' and 'lipoprotein metabolism' showed an excess of genes with high FST. Thus, putative functional SNPs in genes in etiologic pathways for CVD show greater population differentiation than non-functional SNPs and a significant variance of FST values was noted among pairwise population comparisons for different biological processes. Conclusion These results suggest a possible basis for varying susceptibility to CVD among ethnic groups. PMID:17626638

CVD diamond substrate for microelectronics. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burden, J.; Gat, R.

1996-11-01

Chemical Vapor Deposition (CVD) of diamond films has evolved dramatically in recent years, and commercial opportunities for diamond substrates in thermal management applications are promising. The objective of this technology transfer initiative (TTI) is for Applied Science and Technology, Inc. (ASTEX) and AlliedSignal Federal Manufacturing and Technologies (FM&T) to jointly develop and document the manufacturing processes and procedures required for the fabrication of multichip module circuits using CVD diamond substrates, with the major emphasis of the project concentrating on lapping/polishing prior to metallization. ASTEX would provide diamond films for the study, and FM&T would use its experience in lapping, polishing,more » and substrate metallization to perform secondary processing on the parts. The primary goal of the project was to establish manufacturing processes that lower the manufacturing cost sufficiently to enable broad commercialization of the technology.« less

Simple Chemical Vapor Deposition Experiment

ERIC Educational Resources Information Center

Pedersen, Henrik

2014-01-01

Chemical vapor deposition (CVD) is a process commonly used for the synthesis of thin films for several important technological applications, for example, microelectronics, hard coatings, and smart windows. Unfortunately, the complexity and prohibitive cost of CVD equipment makes it seldom available for undergraduate chemistry students. Here, a…

History of preterm birth and subsequent cardiovascular disease: a systematic review

PubMed Central

Robbins, Cheryl L.; Hutchings, Yalonda; Dietz, Patricia M.; Kuklina, Elena V.; Callaghan, William M.

2015-01-01

A history of preterm birth (PTB) may be an important lifetime risk factor for cardiovascular disease (CVD) in women. We identified all peer-reviewed journal articles that met study criteria (English language, human studies, female, and adults ≥19 years old), that were found in the PubMed/MEDLINE databases, and that were published between Jan. 1, 1995, and Sept. 17, 2012. We summarized 10 studies that assessed the association between having a history of PTB and subsequent CVD morbidity or death. Compared with women who had term deliveries, women with any history of PTB had increased risk of CVD morbidity (variously defined; adjusted hazard ratio [aHR] ranged from 1.2e2.9; 2 studies), ischemic heart disease (aHR, 1.3e2.1; 3 studies), stroke (aHR, 1.7; 1 study), and atherosclerosis (aHR, 4.1; 1 study). Four of 5 studies that examined death showed that women with a history of PTB have twice the risk of CVD death compared with women who had term births. Two studies reported statistically significant higher risk of CVD—rerelated morbidity and death outcomes (variously defined) among women with —2 pregnancies that ended in PTBs compared with women who had at least 2 births but which ended in only 1 PTB. Future research is needed to understand the potential impact of enhanced monitoring of CVD risk factors in women with a history of PTB on risk of future CVD risk. PMID:24055578

Central venous device-related thrombosis as imaged with MDCT in oncologic patients: prevalence and findings.

PubMed

Catalano, Orlando; de Lutio di Castelguidone, Elisabetta; Sandomenico, Claudia; Petrillo, Mario; Aprea, Pasquale; Granata, Vincenza; D'Errico, Adolfo Gallipoli

2011-03-01

Venous thrombosis is a common occurrence in cancer patients, developing spontaneously or in combination with indwelling central venous devices (CVD). To analyze the multidetector CT (MDCT) prevalence, appearance, and significance of catheter-related thoracic venous thrombosis in oncologic patients and to determine the percentage of thrombi identified in the original reports. Five hundred consecutive patients were considered. Inclusion criteria were: presence of a CVD; availability of a contrast-enhanced MDCT; and cancer history. Exclusion criteria were: direct tumor compression/infiltration of the veins; poor image quality; device tip not in the scanned volume; and missing clinical data. Seventeen (3.5%) out of the final 481 patients had a diagnosis of venous thrombosis. Factors showing the highest correlation with thrombosis included peripherally-inserted CVD, right brachiocephalic vein tip location, patient performance status 3, metastatic stage disease, ongoing chemotherapy, and longstanding CVD. The highest prevalence was in patients with lymphoma, lung carcinoma, melanoma, and gynecologic malignancies. Eleven out of 17 cases had not been identified in the original report. CVD-related thrombosis is not uncommon in cancer patients and can also be observed in outpatients with a good performance status and a non-metastatic disease. Thrombi can be very tiny. Radiologists should be aware of the possibility to identify (or overlook) small thrombi.

Effects of reducing processed culinary ingredients and ultra-processed foods in the Brazilian diet: a cardiovascular modelling study.

PubMed

Moreira, Patrícia Vl; Hyseni, Lirije; Moubarac, Jean-Claude; Martins, Ana Paula B; Baraldi, Larissa G; Capewell, Simon; O'Flaherty, Martin; Guzman-Castillo, Maria

2018-01-01

To estimate the impact of reducing saturated fat, trans-fat, salt and added sugar from processed culinary ingredients and ultra-processed foods in the Brazilian diet on preventing cardiovascular deaths by 2030. A modelling study. Data were obtained from the Brazilian Household Budget Survey 2008/2009. All food items purchased were categorized into food groups according to the NOVA classification. We estimated the energy and nutrient profile of foods then used the IMPACT Food Policy model to estimate the reduction in deaths from CVD up to 2030 in three scenarios. In Scenario A, we assumed that the intakes of saturated fat, trans-fat, salt and added sugar from ultra-processed foods and processed culinary ingredients were reduced by a quarter. In Scenario B, we assumed a reduction of 50 % of the same nutrients in ultra-processed foods and processed culinary ingredients. In Scenario C, we reduced the same nutrients in ultra-processed foods by 75 % and in processed culinary ingredients by 50 %. Approximately 390 400 CVD deaths might be expected in 2030 if current mortality patterns persist. Under Scenarios A, B and C, CVD mortality can be reduced by 5·5, 11·0 and 29·0 %, respectively. The main impact is on stroke with a reduction of approximately 6·0, 12·6 and 32·0 %, respectively. Substantial potential exists for reducing the CVD burden through overall improvements of the Brazilian diet. This might require reducing the penetration of ultra-processed foods by means of regulatory policies, as well as improving the access to and promotion of fresh and minimally processed foods.

Scalable graphene production: perspectives and challenges of plasma applications

NASA Astrophysics Data System (ADS)

Levchenko, Igor; Ostrikov, Kostya (Ken); Zheng, Jie; Li, Xingguo; Keidar, Michael; B. K. Teo, Kenneth

2016-05-01

Graphene, a newly discovered and extensively investigated material, has many unique and extraordinary properties which promise major technological advances in fields ranging from electronics to mechanical engineering and food production. Unfortunately, complex techniques and high production costs hinder commonplace applications. Scaling of existing graphene production techniques to the industrial level without compromising its properties is a current challenge. This article focuses on the perspectives and challenges of scalability, equipment, and technological perspectives of the plasma-based techniques which offer many unique possibilities for the synthesis of graphene and graphene-containing products. The plasma-based processes are amenable for scaling and could also be useful to enhance the controllability of the conventional chemical vapour deposition method and some other techniques, and to ensure a good quality of the produced graphene. We examine the unique features of the plasma-enhanced graphene production approaches, including the techniques based on inductively-coupled and arc discharges, in the context of their potential scaling to mass production following the generic scaling approaches applicable to the existing processes and systems. This work analyses a large amount of the recent literature on graphene production by various techniques and summarizes the results in a tabular form to provide a simple and convenient comparison of several available techniques. Our analysis reveals a significant potential of scalability for plasma-based technologies, based on the scaling-related process characteristics. Among other processes, a greater yield of 1 g × h-1 m-2 was reached for the arc discharge technology, whereas the other plasma-based techniques show process yields comparable to the neutral-gas based methods. Selected plasma-based techniques show lower energy consumption than in thermal CVD processes, and the ability to produce graphene flakes of various sizes reaching hundreds of square millimetres, and the thickness varying from a monolayer to 10-20 layers. Additional factors such as electrical voltage and current, not available in thermal CVD processes could potentially lead to better scalability, flexibility and control of the plasma-based processes. Advantages and disadvantages of various systems are also considered.

Scalable graphene production: perspectives and challenges of plasma applications.

PubMed

Levchenko, Igor; Ostrikov, Kostya Ken; Zheng, Jie; Li, Xingguo; Keidar, Michael; B K Teo, Kenneth

2016-05-19

Graphene, a newly discovered and extensively investigated material, has many unique and extraordinary properties which promise major technological advances in fields ranging from electronics to mechanical engineering and food production. Unfortunately, complex techniques and high production costs hinder commonplace applications. Scaling of existing graphene production techniques to the industrial level without compromising its properties is a current challenge. This article focuses on the perspectives and challenges of scalability, equipment, and technological perspectives of the plasma-based techniques which offer many unique possibilities for the synthesis of graphene and graphene-containing products. The plasma-based processes are amenable for scaling and could also be useful to enhance the controllability of the conventional chemical vapour deposition method and some other techniques, and to ensure a good quality of the produced graphene. We examine the unique features of the plasma-enhanced graphene production approaches, including the techniques based on inductively-coupled and arc discharges, in the context of their potential scaling to mass production following the generic scaling approaches applicable to the existing processes and systems. This work analyses a large amount of the recent literature on graphene production by various techniques and summarizes the results in a tabular form to provide a simple and convenient comparison of several available techniques. Our analysis reveals a significant potential of scalability for plasma-based technologies, based on the scaling-related process characteristics. Among other processes, a greater yield of 1 g × h(-1) m(-2) was reached for the arc discharge technology, whereas the other plasma-based techniques show process yields comparable to the neutral-gas based methods. Selected plasma-based techniques show lower energy consumption than in thermal CVD processes, and the ability to produce graphene flakes of various sizes reaching hundreds of square millimetres, and the thickness varying from a monolayer to 10-20 layers. Additional factors such as electrical voltage and current, not available in thermal CVD processes could potentially lead to better scalability, flexibility and control of the plasma-based processes. Advantages and disadvantages of various systems are also considered.

Psychological factors and mortality in the Japan Collaborative Cohort Study for Evaluation of Cancer (JACC).

PubMed

Tanno, Kozo; Sakata, Kiyomi

2007-01-01

Psychological factors may have an influence on disease processes and therefore they were investigated in the Japan Collaborative Cohort Study. Overall there were very few consistent associations with cancer death. Persons with 'ikigai', defined as 'that which most makes one's life seem worth living', demonstrated decreased risk of mortality from all causes, ischemic heart disease (IHD) and cerebrovascular disease (CVD).There was no consistent link with being quick to judge, although those answering no to quick judgement were at increased risk of all cause, IHD and CVD mortality. psychological stress was related to a slightly elevated risk of all cause death, IHD in men and CVD in women. However, a sense of hurry was linked to a slightly reduced risk for mortality from all causes and CVD. Persons who were likely to be angry had an increased risk for mortality from all causes. In women not likely to be angry there were also positive links to death from cancers like breast. Joyfulness was associated with decreased mortality, especially from CVD. A feeling of being trusted was also protective, again particularly for CVD.

Specific Amino Acids Affect Cardiovascular Diseases and Atherogenesis via Protection against Macrophage Foam Cell Formation: Review Article.

PubMed

Grajeda-Iglesias, Claudia; Aviram, Michael

2018-06-20

The strong relationship between cardiovascular diseases (CVD), atherosclerosis, and endogenous or exogenous lipids has been recognized for decades, underestimating the contribution of other dietary components, such as amino acids, to the initiation of the underlying inflammatory disease. Recently, specific amino acids have been associated with incident cardiovascular disorders, suggesting their significant role in the pathogenesis of CVD. Special attention has been paid to the group of branched-chain amino acids (BCAA), leucine, isoleucine, and valine, since their plasma values are frequently found in high concentrations in individuals with CVD risk. Nevertheless, dietary BCAA, leucine in particular, have been associated with improved indicators of atherosclerosis. Therefore, their potential role in the process of atherogenesis and concomitant CVD development remains unclear. Macrophages play pivotal roles in the development of atherosclerosis. They can accumulate high amounts of circulating lipids, through a process known as macrophage foam cell formation, and initiate the atherogenesis process. We have recently screened for anti- or pro-atherogenic amino acids in the macrophage model system. Our study showed that glycine, cysteine, alanine, leucine, glutamate, and glutamine significantly affected macrophage atherogenicity mainly through modulation of the cellular triglyceride metabolism. The anti-atherogenic properties of glycine and leucine, and the pro-atherogenic effects of glutamine, were also confirmed in vivo. Further investigation is warranted to define the role of these amino acids in atherosclerosis and CVD, which may serve as a basis for the development of anti-atherogenic nutritional and therapeutic approaches.

Improving Medication Adherence in Cardiometabolic Disease: Practical and Regulatory Implications.

PubMed

Ferdinand, Keith C; Senatore, Fortunato Fred; Clayton-Jeter, Helene; Cryer, Dennis R; Lewin, John C; Nasser, Samar A; Fiuzat, Mona; Califf, Robert M

2017-01-31

Medication nonadherence, a major problem in cardiovascular disease (CVD), contributes yearly to approximately 125,000 preventable deaths, which is partly attributable to only about one-half of CVD patients consistently taking prescribed life-saving medications. Current interest has focused on how labeling and education influence adherence. This paper summarizes the scope of CVD nonadherence, describes key U.S. Food and Drug Administration initiatives, and identifies potential targets for improvement. We describe key adherence factors, methods, and technological applications for simplifying regimens and enhancing adherence, and 4 areas where additional collaborative research and implementation involving the regulatory system and clinical community could substantially reduce nonadherence: 1) identifying monitoring methods; 2) improving the evidence base to better understand adherence; 3) developing patient/health provider team-based engagement strategies; and 4) alleviating health disparities. Alignment of U.S. Food and Drug Administration approaches to dissemination of information about appropriate use with clinical practice could improve adherence, and thereby reduce CVD death and disability. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Ferromagnetic tunnel contacts to graphene: Contact resistance and spin signal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cubukcu, M.; Laczkowski, P.; Vergnaud, C.

2015-02-28

We report spin transport in CVD graphene-based lateral spin valves using different magnetic contacts. We compared the spin signal amplitude measured on devices where the cobalt layer is directly in contact with the graphene to the one obtained using tunnel contacts. Although a sizeable spin signal (up to ∼2 Ω) is obtained with direct contacts, the signal is strongly enhanced (∼400 Ω) by inserting a tunnel barrier. In addition, we studied the resistance-area product (R.A) of a variety of contacts on CVD graphene. In particular, we compared the R.A products of alumina and magnesium oxide tunnel barriers grown by sputteringmore » deposition of aluminum or magnesium and subsequent natural oxidation under pure oxygen atmosphere or by plasma. When using an alumina tunnel barrier on CVD graphene, the R.A product is high and exhibits a large dispersion. This dispersion can be highly reduced by using a magnesium oxide tunnel barrier, as for the R.A value. This study gives insight in the material quest for reproducible and efficient spin injection in CVD graphene.« less

The Burden of Cardiovascular Diseases Among US States, 1990-2016.

PubMed

Roth, Gregory A; Johnson, Catherine O; Abate, Kalkidan Hassen; Abd-Allah, Foad; Ahmed, Muktar; Alam, Khurshid; Alam, Tahiya; Alvis-Guzman, Nelson; Ansari, Hossein; Ärnlöv, Johan; Atey, Tesfay Mehari; Awasthi, Ashish; Awoke, Tadesse; Barac, Aleksandra; Bärnighausen, Till; Bedi, Neeraj; Bennett, Derrick; Bensenor, Isabela; Biadgilign, Sibhatu; Castañeda-Orjuela, Carlos; Catalá-López, Ferrán; Davletov, Kairat; Dharmaratne, Samath; Ding, Eric L; Dubey, Manisha; Faraon, Emerito Jose Aquino; Farid, Talha; Farvid, Maryam S; Feigin, Valery; Fernandes, João; Frostad, Joseph; Gebru, Alemseged; Geleijnse, Johanna M; Gona, Philimon Nyakauru; Griswold, Max; Hailu, Gessessew Bugssa; Hankey, Graeme J; Hassen, Hamid Yimam; Havmoeller, Rasmus; Hay, Simon; Heckbert, Susan R; Irvine, Caleb Mackay Salpeter; James, Spencer Lewis; Jara, Dube; Kasaeian, Amir; Khan, Abdur Rahman; Khera, Sahil; Khoja, Abdullah T; Khubchandani, Jagdish; Kim, Daniel; Kolte, Dhaval; Lal, Dharmesh; Larsson, Anders; Linn, Shai; Lotufo, Paulo A; Magdy Abd El Razek, Hassan; Mazidi, Mohsen; Meier, Toni; Mendoza, Walter; Mensah, George A; Meretoja, Atte; Mezgebe, Haftay Berhane; Mirrakhimov, Erkin; Mohammed, Shafiu; Moran, Andrew Edward; Nguyen, Grant; Nguyen, Minh; Ong, Kanyin Liane; Owolabi, Mayowa; Pletcher, Martin; Pourmalek, Farshad; Purcell, Caroline A; Qorbani, Mostafa; Rahman, Mahfuzar; Rai, Rajesh Kumar; Ram, Usha; Reitsma, Marissa Bettay; Renzaho, Andre M N; Rios-Blancas, Maria Jesus; Safiri, Saeid; Salomon, Joshua A; Sartorius, Benn; Sepanlou, Sadaf Ghajarieh; Shaikh, Masood Ali; Silva, Diego; Stranges, Saverio; Tabarés-Seisdedos, Rafael; Tadele Atnafu, Niguse; Thakur, J S; Topor-Madry, Roman; Truelsen, Thomas; Tuzcu, E Murat; Tyrovolas, Stefanos; Ukwaja, Kingsley Nnanna; Vasankari, Tommi; Vlassov, Vasiliy; Vollset, Stein Emil; Wakayo, Tolassa; Weintraub, Robert; Wolfe, Charles; Workicho, Abdulhalik; Xu, Gelin; Yadgir, Simon; Yano, Yuichiro; Yip, Paul; Yonemoto, Naohiro; Younis, Mustafa; Yu, Chuanhua; Zaidi, Zoubida; Zaki, Maysaa El Sayed; Zipkin, Ben; Afshin, Ashkan; Gakidou, Emmanuela; Lim, Stephen S; Mokdad, Ali H; Naghavi, Mohsen; Vos, Theo; Murray, Christopher J L

2018-04-11

Cardiovascular disease (CVD) is the leading cause of death in the United States, but regional variation within the United States is large. Comparable and consistent state-level measures of total CVD burden and risk factors have not been produced previously. To quantify and describe levels and trends of lost health due to CVD within the United States from 1990 to 2016 as well as risk factors driving these changes. Using the Global Burden of Disease methodology, cardiovascular disease mortality, nonfatal health outcomes, and associated risk factors were analyzed by age group, sex, and year from 1990 to 2016 for all residents in the United States using standardized approaches for data processing and statistical modeling. Burden of disease was estimated for 10 groupings of CVD, and comparative risk analysis was performed. Data were analyzed from August 2016 to July 2017. Residing in the United States. Cardiovascular disease disability-adjusted life-years (DALYs). Between 1990 and 2016, age-standardized CVD DALYs for all states decreased. Several states had large rises in their relative rank ordering for total CVD DALYs among states, including Arkansas, Oklahoma, Alabama, Kentucky, Missouri, Indiana, Kansas, Alaska, and Iowa. The rate of decline varied widely across states, and CVD burden increased for a small number of states in the most recent years. Cardiovascular disease DALYs remained twice as large among men compared with women. Ischemic heart disease was the leading cause of CVD DALYs in all states, but the second most common varied by state. Trends were driven by 12 groups of risk factors, with the largest attributable CVD burden due to dietary risk exposures followed by high systolic blood pressure, high body mass index, high total cholesterol level, high fasting plasma glucose level, tobacco smoking, and low levels of physical activity. Increases in risk-deleted CVD DALY rates between 2006 and 2016 in 16 states suggest additional unmeasured risks beyond these traditional factors. Large disparities in total burden of CVD persist between US states despite marked improvements in CVD burden. Differences in CVD burden are largely attributable to modifiable risk exposures.

Mediator complex dependent regulation of cardiac development and disease.

PubMed

Grueter, Chad E

2013-06-01

Cardiovascular disease (CVD) is a leading cause of morbidity and mortality. The risk factors for CVD include environmental and genetic components. Human mutations in genes involved in most aspects of cardiovascular function have been identified, many of which are involved in transcriptional regulation. The Mediator complex serves as a pivotal transcriptional regulator that functions to integrate diverse cellular signals by multiple mechanisms including recruiting RNA polymerase II, chromatin modifying proteins and non-coding RNAs to promoters in a context dependent manner. This review discusses components of the Mediator complex and the contribution of the Mediator complex to normal and pathological cardiac development and function. Enhanced understanding of the role of this core transcriptional regulatory complex in the heart will help us gain further insights into CVD. Copyright © 2013. Production and hosting by Elsevier Ltd.

Chemical Vapor Deposition of Aluminum Oxide Thin Films

ERIC Educational Resources Information Center

Vohs, Jason K.; Bentz, Amy; Eleamos, Krystal; Poole, John; Fahlman, Bradley D.

2010-01-01

Chemical vapor deposition (CVD) is a process routinely used to produce thin films of materials via decomposition of volatile precursor molecules. Unfortunately, the equipment required for a conventional CVD experiment is not practical or affordable for many undergraduate chemistry laboratories, especially at smaller institutions. In an effort to…

Fabrication of lightweight Si/SiC LIDAR mirrors

NASA Technical Reports Server (NTRS)

Goela, Jitendra S.; Taylor, Raymond L.

1991-01-01

A new, chemical vapor deposition (CVD) process was developed for fabricating lightweight, polycrystalline silicon/silicon-carbide (Si/SiC) mirrors. The process involves three CVD steps: (1) to produce the mirror faceplate; (2) to form the lightweight backstructure, which is deposited integral to the faceplate; and (3) to deposit a layer of optical-grade material, e.g., Si, onto the front surface of the faceplate. The mirror figure and finish are fabricated into the faceplate.

Natriuretic Peptide and High-Sensitivity Troponin for Cardiovascular Risk Prediction in Diabetes: The Atherosclerosis Risk in Communities (ARIC) Study

PubMed Central

Gori, Mauro; Gupta, Deepak K.; Claggett, Brian; Selvin, Elizabeth; Folsom, Aaron R.; Matsushita, Kunihiro; Bello, Natalie A.; Cheng, Susan; Shah, Amil; Skali, Hicham; Vardeny, Orly; Ni, Hanyu; Ballantyne, Christie M.; Astor, Brad C.; Klein, Barbara E.; Aguilar, David

2016-01-01

OBJECTIVE Cardiovascular disease (CVD) is the major cause of morbidity and mortality in diabetes; yet, heterogeneity in CVD risk has been suggested in diabetes, providing a compelling rationale for improving diabetes risk stratification. We hypothesized that N-terminal prohormone brain natriuretic peptide (NTproBNP) and high-sensitivity troponin T may enhance CVD risk stratification beyond commonly used markers of risk and that CVD risk is heterogeneous in diabetes. RESEARCH DESIGN AND METHODS Among 8,402 participants without prevalent CVD at visit 4 (1996–1998) of the Atherosclerosis Risk in Communities (ARIC) study there were 1,510 subjects with diabetes (mean age 63 years, 52% women, 31% African American, and 60% hypertensive). RESULTS Over a median follow-up of 13.1 years, there were 540 incident fatal/nonfatal CVD events (coronary heart disease, heart failure, and stroke). Both troponin T ≥14 ng/L (hazard ratio [HR] 1.96 [95% CI 1.57–2.46]) and NTproBNP >125 pg/mL (1.61 [1.29–1.99]) were independent predictors of incident CVD events at multivariable Cox proportional hazard models. Addition of circulating cardiac biomarkers to traditional risk factors, abnormal electrocardiogram (ECG), and conventional markers of diabetes complications including retinopathy, nephropathy, and peripheral arterial disease significantly improved CVD risk prediction (net reclassification index 0.16 [95% CI 0.07–0.22]). Compared with individuals without diabetes, subjects with diabetes had 1.6-fold higher adjusted risk of incident CVD. However, participants with diabetes with normal cardiac biomarkers and no conventional complications/abnormal ECG (n = 725 [48%]) were at low risk (HR 1.12 [95% CI 0.95–1.31]), while those with abnormal cardiac biomarkers, alone (n = 186 [12%]) or in combination with conventional complications/abnormal ECG (n = 243 [16%]), were at greater risk (1.99 [1.59–2.50] and 2.80 [2.34–3.35], respectively). CONCLUSIONS Abnormal levels of NTproBNP and troponin T may help to distinguish individuals with high diabetes risk from those with low diabetes risk, providing incremental risk prediction beyond commonly used markers of risk. PMID:26740635

Education status determines 10-year (2002-2012) survival from cardiovascular disease in Athens metropolitan area: the ATTICA study, Greece.

PubMed

Panagiotakos, Demosthenes; Georgousopoulou, Ekavi; Notara, Venetia; Pitaraki, Evangelia; Kokkou, Eleni; Chrysohoou, Christina; Skoumas, Yannis; Metaxa, Vassiliki; Pitsavos, Christos; Stefanadis, Christodoulos

2016-05-01

Cardiovascular disease (CVD) remains the leading cause of morbidity and mortality worldwide, and educational level seems to be an important determinant of the disease occurrence. The aim of this work was to investigate the association between education status and 10-year incidence of CVD, controlling for various socio-demographic lifestyle and clinical factors. From May 2001 to December 2002, 1514 men and 1528 women (>18 years) without any clinical evidence of CVD or any other chronic disease, at baseline, living in greater Athens area, Greece, were enrolled. In 2011-2012, the 10-year follow-up was performed in 2583 participants (15% of the participants were lost to follow-up). Incidence of fatal or non-fatal CVD was defined according to WHO-ICD-10 criteria. Education status was measured in years of schooling. The 10-year incidence of CVD was 15.7% [95% confidence intervals (CI) 14.1%-17.4%], 19.7% in men and 11.7% in women (Pgender < 0.001). Age-and gender-adjusted analyses revealed that those with low education (<9 years of schooling) were 1.52 times more likely (95% CI 1.03-2.23%) to have CVD compared with those with high education (>12 years of schooling). People in the low education group had higher prevalence of hypertension, diabetes and dyslipidaemias, were more likely to be smokers and sedentary, had less healthy dietary habits, as compared with those in the high education group. When controlling for participants' medical history, smoking, dietary and lifestyle habits, low education was no longer significantly associated with CVD, illustrating the mediating effect of clinical and behavioural factors in the link between education and disease. It was of interest that low education status interacted with alcohol drinking, enhancing the adverse effect of low education on CVD risk (relative risk 1.44, 95% CI 0.94%-2.20%), after various adjustments made. In this study, it was concluded that low educational level was associated with increased CVD risk. This was mainly explained by the intermediate association of low education with unhealthy choices that consequently worsen clinical status. © 2015 John Wiley & Sons Ltd.

Interplay between Oxidative Stress and Nutrient Sensing Signaling in the Developmental Origins of Cardiovascular Disease

PubMed Central

Tain, You-Lin; Hsu, Chien-Ning

2017-01-01

Cardiovascular disease (CVD) presents a global health burden, despite recent advances in management. CVD can originate from early life by so-called “developmental origins of health and disease” (DOHaD). Epidemiological and experimental evidence supports that early-life insults can induce programming of later CVD. Underlying the DOHaD concept, early intervention may offset programming process to prevent the development of CVD, namely reprogramming. Oxidative stress and nutrient sensing signals have been considered to be major mechanisms of cardiovascular programming, while the interplay between these two mechanisms have not been examined in detail. This review summarizes current evidence that supports the link between oxidative stress and nutrient sensing signaling to cardiovascular programming, with an emphasis on the l-arginine–asymmetric dimethylarginine (ADMA)–nitric oxide (NO) pathway. This review provides an overview of evidence from human studies supporting fetal programming of CVD, insight from animal models of cardiovascular programming and oxidative stress, impact of the l-arginine–ADMA–NO pathway in cardiovascular programming, the crosstalk between l-arginine metabolism and nutrient sensing signals, and application of reprogramming interventions to prevent the programming of CVD. A greater understanding of the mechanisms underlying cardiovascular programming is essential to developing early reprogramming interventions to combat the globally growing epidemic of CVD. PMID:28420139

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ioakeimidis, Apostolos; Christodoulou, Christos; Lux-Steiner, Martha

In this work we fabricate all-vacuum processed methyl ammonium lead halide perovskite by a sequence of physical vapour deposition of PbI{sub 2} and chemical vapour deposition (CVD) of CH{sub 3}NH{sub 3}I under a static atmosphere. We demonstrate that for higher deposition rate the (001) planes of PbI{sub 2} film show a higher degree of alignment parallel to the sample's surface. From X-ray diffraction data of the resulted perovskite film we derive that the intercalation rate of CH{sub 3}NH{sub 3}I is fostered for PbI{sub 2} films with higher degree of (001) planes alignment. The stoichiometry of the produced perovskite film ismore » also studied by Hard X-ray photoelectron spectroscopy measurements. Complete all-vacuum perovskite solar cells were fabricated on glass/ITO substrates coated by an ultra-thin (5 nm) Zn-phthalocyanine film as hole selective layer. A dependence of residual PbI{sub 2} on the solar cells performance is displayed, while photovoltaic devices with efficiency up to η=11.6% were achieved. - Graphical abstract: A two-step PVD/CVD processed perovskite film with the CVD intercalation rate of CH{sub 3}NCH{sub 3} molecules been fostered by increasing the PVD rate of PbI{sub 2} and prolonging the CVD time. - Highlights: • A simple PVD/CVD process for perovskite film production. • Increased PVD rate yields better alignment of the PbI{sub 2} (001) crystallite planes. • CH{sub 3}NH{sub 3}I intercalation process fostered by increased PbI{sub 2} PVD rate. • Stoichiometric CH{sub 3}NH{sub 3}PbI{sub 3} suitable as absorber in photovoltaic applications • Reduced PbI{sub 2} residue at the bottom of CH{sub 3}NH{sub 3}PbI{sub 3} improves device performance.« less

APOC3 induces endothelial dysfunction through TNF-α and JAM-1.

PubMed

Tao, Yun; Xiong, Yisong; Wang, Huimin; Chu, Shaopeng; Zhong, Renqian; Wang, Jianxin; Wang, Guihua; Ren, Xiumei; Yu, Juan

2016-09-13

The fatality rate for cardiovascular disease (CVD) has increased in recent years and higher levels of triglyceride have been shown to be an independent risk factor for atherosclerotic CVD. Dysfunction of endothelial cells (ECs) is also a key factor of CVD. APOC3 is an important molecule in lipid metabolism that is closely associated with hyperlipidemia and an increased risk of developing CVD. But the direct effects of APOC3 on ECs were still unknown. This study was aimed at determining the effects of APOC3 on inflammation, chemotaxis and exudation in ECs. ELISA, qRT-PCR, immunofluorescence, flow cytometry and transwell assays were used to investigate the effects of APOC3 on human umbilical vein endothelial cells (HUVECs). SiRNA-induced TNF-α and JAM-1 silencing were used to observe how APOC3 influenced the inflammatory process in the ECs. Our results showed that APOC3 was closely associated with the inflammatory process in ECs, and that this process was characterized by the increased expression of TNF-α. Inflammatory processes further disrupted the tight junctions (TJs) between HUVECs by causing increased expression of JAM-1. JAM-1 was involved in maintaining the integrity of TJs, and it promoted the assembly of platelets and the exudation of leukocytes. Changes in its expression promoted chemotaxis and the exudation of ECs, which contributed to atherosclerosis. While the integrity of the TJs was disrupted, the adhesion of THP-1 cells to HUVECs was also increased by APOC3. In this study, we describe the mechanism by which APOC3 causes inflammation, chemotaxis and the exudation of ECs, and we suggest that controlling the inflammatory reactions that are caused by APOC3 may be a new method to treat CVD.

Evaluating the use of mobile phone technology to enhance cardiovascular disease screening by community health workers.

PubMed

Surka, Sam; Edirippulige, Sisira; Steyn, Krisela; Gaziano, Thomas; Puoane, Thandi; Levitt, Naomi

2014-09-01

Primary prevention of cardiovascular disease (CVD),by identifying individuals at risk is a well-established, but costly strategy when based on measurements that depend on laboratory analyses. A non-laboratory, paper-based CVD risk assessment chart tool has previously been developed to make screening more affordable in developing countries. Task shifting to community health workers (CHWs) is being investigated to further scale CVD risk screening. This study aimed to develop a mobile phone CVD risk assessment application and to evaluate its impact on CHW training and the duration of screening for CVD in the community by CHWs. A feature phone application was developed using the open source online platform, CommCare(©). CHWs (n=24) were trained to use both paper-based and mobile phone CVD risk assessment tools. They were randomly allocated to using one of the risk tools to screen 10-20 community members and then crossed over to screen the same number, using the alternate risk tool. The impact on CHW training time, screening time and margin of error in calculating risk scores was recorded. A focus group discussion evaluated experiences of CHWs using the two tools. The training time was 12.3h for the paper-based chart tool and 3h for the mobile phone application. 537 people were screened. The mean screening time was 36 min (SD=12.6) using the paper-base chart tool and 21 min (SD=8.71) using the mobile phone application, p=<0.0001. Incorrect calculations (4.3% of average systolic BP measurements, 10.4% of BMI and 3.8% of CVD risk score) were found when using the paper-based chart tool while all the mobile phone calculations were correct. Qualitative findings from the focus group discussion corresponded with the findings of the pilot study. The reduction in CHW training time, CVD risk screening time, lack of errors in calculation of a CVD risk score and end user satisfaction when using a mobile phone application, has implications in terms of adoption and sustainability of this primary prevention strategy to identify people with high CVD risk who can be referred for appropriate diagnoses and treatment. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Evaluating the use of mobile phone technology to enhance cardiovascular disease screening by community health workers

PubMed Central

Surka, Sam; Edirippulige, Sisira; Steyn, Krisela; Gaziano, Thomas; Puoane, Thandi; Levitt, Naomi

2014-01-01

Background Primary prevention of cardiovascular disease (CVD),by identifying individuals at risk is a well-established, but costly strategy when based on measurements that depend on laboratory analyses. A non-laboratory, paper-based CVD risk assessment chart tool has previously been developed to make screening more affordable in developing countries. Task shifting to community health workers (CHWs) is being investigated to further scale CVD risk screening. This study aimed to develop a mobile phone CVD risk assessment application and to evaluate it’s impact on CHW training and the duration of screening for CVD in the community by CHWs. Methods A feature phone application was developed using the open source online platform, CommCare©. CHWs (n=24) were trained to use both paper-based and mobile phone CVD risk assessment tools. They were randomly allocated to using one of the risk tools to screen 10-20 community members and then crossed over to screen the same number, using the alternate risk tool. The impact on CHW training time, screening time and margin of error in calculating risk scores was recorded. A focus group discussion evaluated experiences of CHWs using the two tools. Results The training time was 12.3 hrs for the paper-based chart tool and 3 hours for the mobile phone application. 537 people were screened. The mean screening time was 36 minutes (SD=12.6) using the paper-base chart tool and 21 minutes (SD=8.71) using the mobile phone application , p = <0.0001. Incorrect calculations (4.3 % of average systolic BP measurements, 10.4 % of BMI and 3.8% of CVD risk score) were found when using the paper-based chart tool while all the mobile phone calculations were correct. Qualitative findings from the focus group discussion corresponded with the findings of the pilot study. Conclusion The reduction in CHW training time, CVD risk screening time, lack of errors in calculation of a CVD risk score and end user satisfaction when using a mobile phone application, has implications in terms of adoption and sustainability of this primary prevention strategy to identify people with high CVD risk who can be referred for appropriate diagnoses and treatment. PMID:25002305

Development of CVD mullite coatings for Si-based ceramics

NASA Astrophysics Data System (ADS)

Auger, Michael Lawrence

1999-09-01

To raise fuel efficiencies, the next generation of engines and fuel systems must be lighter and operate at higher temperatures. Ceramic-based materials, which are considerably lighter than metals and can withstand working temperatures of up to 1400sp°C, have been targeted to replace traditional metal-based components. The materials used in combustion environments must also be capable of withstanding erosion and corrosion caused by combustion gases, particulates, and deposit-forming corrodants. With these demanding criteria, silicon-based ceramics are the leading candidate materials for high temperature engine and heat exchanger structural components. However, these materials are limited in gaseous environments and in the presence of molten salts since they form liquid silicates on exposed surfaces at temperatures as low as 800sp°C. Protective coatings that can withstand higher operating temperatures and corrosive atmospheres must be developed for silicon-based ceramics. Mullite (3Alsb2Osb3{*}2SiOsb2) was targeted as a potential coating material due to its unique ability to resist corrosion, retain its strength, resist creep, and avoid thermal shock failure at elevated temperatures. Several attempts to deposit mullite coatings by various processing methods have met with limited success and usually resulted in coatings that have had pores, cracks, poor adherence, and required thermal post-treatments. To overcome these deficiencies, the direct formation of chemically vapor deposited (CVD) mullite coatings has been developed. CVD is a high temperature atomistic deposition technique that results in dense, adherent crystalline coatings. The object of this dissertation was to further the understanding of the CVD mullite deposition process and resultant coating. The kinetics of CVD mullite deposition were investigated as a function of the following process parameters: temperature, pressure, and the deposition reactor system. An empirical kinetic model was developed indicating that an intermediate gaseous reaction is significant to the growth rate of mullite. CVD mullite coatings were deposited on SiC and Sisb3Nsb4 substrates and subjected to both simulated coal gasification and simulated jet fuel combustion conditions. Corrosion resistance of CVD mullite coated ceramics was superior to traditional refractory materials including alumina, solid mullite, Sisb3Nsb4, and silicon carbide.

Efficiency enhancement of silicon nanowire solar cells by using UV/Ozone treatments and micro-grid electrodes

NASA Astrophysics Data System (ADS)

Chen, Junyi; Subramani, Thiyagu; Sun, Yonglie; Jevasuwan, Wipakorn; Fukata, Naoki

2018-05-01

Silicon nanowire solar cells were fabricated by metal catalyzed electroless etching (MCEE) followed by thermal chemical vapor deposition (CVD). In this study, we investigated two effects, a UV/ozone treatment and the use of a micro-grid electrodes, to enhance light absorption and reduce the optic losses in the solar cell device. The UV/ozone treatment successfully improved the conversion efficiency. The micro-grid electrodes were then applied in solar cell devices subjected to a back surface field (BSF) treatment and rapid thermal annealing (RTA). These effects improved the conversion efficiency from 9.4% to 10.9%. Moreover, to reduce surface recombination and improve the continuity of front electrodes, we optimized the etching time of the MCEE process, giving a high efficiency of 12.3%.

Estrogen Receptors and Chronic Venous Disease.

PubMed

Serra, R; Gallelli, L; Perri, P; De Francesco, E M; Rigiracciolo, D C; Mastroroberto, P; Maggiolini, M; de Franciscis, S

2016-07-01

Chronic venous disease (CVD) is a common and relevant problem affecting Western people. The role of estrogens and their receptors in the venous wall seems to support the major prevalence of CVD in women. The effects of the estrogens are mediated by three estrogen receptors (ERs): ERα, ERβ, and G protein-coupled ER (GPER). The expression of ERs in the vessel walls of varicose veins is evaluated. In this prospective study, patients of both sexes, with CVD and varicose veins undergoing open venous surgery procedures, were enrolled in order to obtain vein samples. To obtain control samples of healthy veins, patients of both sexes without CVD undergoing coronary artery bypass grafting with autologous saphenous vein were recruited (control group). Samples were processed in order to evaluate gene expression. Forty patients with CVD (10 men [25%], 30 women [75%], mean age 54.3 years [median 52 years, range 33-74 years]) were enrolled. Five patients without CVD (three men, two women [aged 61-73 years]) were enrolled as the control group. A significant increase of tissue expression of ERα, ERβ and GPER in patients with CVD was recorded (p < .01), which was also related to the severity of venous disease. ERs seem to play a role in CVD; in this study, the expression of ERs correlated with the severity of the disease, and their expression was correlated with the clinical stage. Copyright © 2016 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Atherosclerotic Cardiovascular Disease Beginning in Childhood

PubMed Central

2010-01-01

Although the clinical manifestations of cardiovascular disease (CVD), such as myocardial infarction, stroke, and peripheral vascular disease, appear from middle age, the process of atherosclerosis can begin early in childhood. The early stage and progression of atherosclerosis in youth are influenced by risk factors that include obesity, hypertension, dyslipidemia, and smoking, and by the presence of specific diseases, such as diabetes mellitus and Kawasaki disease (KD). The existing evidence indicates that primary prevention of atherosclerotic disease should begin in childhood. Identification of children at risk for atherosclerosis may allow early intervention to decrease the atherosclerotic process, thereby preventing or delaying CVD. This review will describe the origin and progression of atherosclerosis in childhood, and the identification and management of known risk factors for atherosclerotic CVD in children and young adults. PMID:20111646

Direct synthesis of vertically aligned ZnO nanowires on FTO substrates using a CVD method and the improvement of photovoltaic performance

PubMed Central

2012-01-01

In this work, we report a direct synthesis of vertically aligned ZnO nanowires on fluorine-doped tin oxide-coated substrates using the chemical vapor deposition (CVD) method. ZnO nanowires with a length of more than 30 μm were synthesized, and dye-sensitized solar cells (DSSCs) based on the as-grown nanowires were fabricated, which showed improvement of the device performance compared to those fabricated using transferred ZnO nanowires. Dependence of the cell performance on nanowire length and annealing temperature was also examined. This synthesis method provided a straightforward, one-step CVD process to grow relatively long ZnO nanowires and avoided subsequent nanowire transfer process, which simplified DSSC fabrication and improved cell performance. PMID:22673046

Enhanced photoresponse characteristics of transistors using CVD-grown MoS2/WS2 heterostructures

NASA Astrophysics Data System (ADS)

Shan, Junjie; Li, Jinhua; Chu, Xueying; Xu, Mingze; Jin, Fangjun; Fang, Xuan; Wei, Zhipeng; Wang, Xiaohua

2018-06-01

Semiconductor heterostructures based on transition metal dichalcogenides provide a broad platform to research two-dimensional nanomaterials and design atomically thin devices for fundamental and applied interests. The MoS2/WS2 heterostructure was prepared on SiO2/Si substrate by chemical vapor deposition (CVD) in our research. And the optical properties of the heterostructure was characterized by Raman and photoluminescence (PL) spectroscopy. The similar 2 orders of magnitude decrease of PL intensity in MoS2/WS2 heterostructures was tested, which is attribute to the electrical and optical modulation effects are connected with the interfacial charge transfer between MoS2 and WS2 films. Using MoS2/WS2 heterostructure as channel material of the phototransistor, we demonstrated over 50 folds enhanced photoresponsivity of multilayer MoS2 field-effect transistor. The results indicate that the MoS2/WS2 films can be a promising heterostructure material to enhance the photoresponse characteristics of MoS2-based phototransistors.

Intervention Trials with the Mediterranean Diet in Cardiovascular Prevention: Understanding Potential Mechanisms through Metabolomic Profiling.

PubMed

Martínez-González, Miguel Á; Ruiz-Canela, Miguel; Hruby, Adela; Liang, Liming; Trichopoulou, Antonia; Hu, Frank B

2016-03-09

Large observational epidemiologic studies and randomized trials support the benefits of a Mediterranean dietary pattern on cardiovascular disease (CVD). Mechanisms postulated to mediate these benefits include the reduction of low-grade inflammation, increased adiponectin concentrations, decreased blood coagulation, enhanced endothelial function, lower oxidative stress, lower concentrations of oxidized LDL, and improved apolipoprotein profiles. However, the metabolic pathways through which the Mediterranean diet influences CVD risk remain largely unknown. Investigating specific mechanisms in the context of a large intervention trial with the use of high-throughput metabolomic profiling will provide more solid public health messages and may help to identify key molecular targets for more effective prevention and management of CVD. Although metabolomics is not without its limitations, the techniques allow for an assessment of thousands of metabolites, providing wide-ranging profiling of small molecules related to biological status. Specific candidate plasma metabolites that may be associated with CVD include branched-chain and aromatic amino acids; the glutamine-to-glutamate ratio; some short- to medium-chain acylcarnitines; gut flora metabolites (choline, betaine, and trimethylamine N-oxide); urea cycle metabolites (citrulline and ornithine); and specific lipid subclasses. In addition to targeted metabolites, the role of a large number of untargeted metabolites should also be assessed. Large intervention trials with the use of food patterns for the prevention of CVD provide an unparalleled opportunity to examine the effects of these interventions on plasma concentrations of specific metabolites and determine whether such changes mediate the benefits of the dietary interventions on CVD risk. © 2016 American Society for Nutrition.

Advanced purification of petroleum refinery wastewater by catalytic vacuum distillation.

PubMed

Yan, Long; Ma, Hongzhu; Wang, Bo; Mao, Wei; Chen, Yashao

2010-06-15

In our work, a new process, catalytic vacuum distillation (CVD) was utilized for purification of petroleum refinery wastewater that was characteristic of high chemical oxygen demand (COD) and salinity. Moreover, various common promoters, like FeCl(3), kaolin, H(2)SO(4) and NaOH were investigated to improve the purification efficiency of CVD. Here, the purification efficiency was estimated by COD testing, electrolytic conductivity, UV-vis spectrum, gas chromatography-mass spectrometry (GC-MS) and pH value. The results showed that NaOH promoted CVD displayed higher efficiency in purification of refinery wastewater than other systems, where the pellucid effluents with low salinity and high COD removal efficiency (99%) were obtained after treatment, and the corresponding pH values of effluents varied from 7 to 9. Furthermore, environment estimation was also tested and the results showed that the effluent had no influence on plant growth. Thus, based on satisfied removal efficiency of COD and salinity achieved simultaneously, NaOH promoted CVD process is an effective approach to purify petroleum refinery wastewater. Copyright 2010 Elsevier B.V. All rights reserved.

Observation of Charge Generation and Transfer during CVD Growth of Carbon Nanotubes.

PubMed

Wang, Jiangtao; Liu, Peng; Xia, Bingyu; Wei, Haoming; Wei, Yang; Wu, Yang; Liu, Kai; Zhang, Lina; Wang, Jiaping; Li, Qunqing; Fan, Shoushan; Jiang, Kaili

2016-07-13

Carbon nanotube (CNT) is believed to be the most promising material for next generation IC industries with the prerequisite of chirality specific growth. For various approaches to controlling the chiral indices of CNTs, the key is to deepen the understanding of the catalytic growth mechanism in chemical vapor deposition (CVD). Here we show our discovery that the as-grown CNTs are all negatively charged after Fe-catalyzed CVD process. The extra electrons come from the charge generation and transfer during the growth of CNTs, which indicates that an electrochemical process happens in the surface reaction step. We then designed an in situ measurement equipment, verifying that the CVD growth of CNTs can be regarded as a primary battery system. Furthermore, we found that the variation of the Fermi level in Fe catalysts have a significant impact on the chirality of CNTs when different external electric fields are applied. These findings not only provide a new perspective on the growth of CNTs but also open up new possibilities for controlling the growth of CNTs by electrochemical methods.

Development of the Champlain primary care cardiovascular disease prevention and management guideline

PubMed Central

Montoya, Lorraine; Liddy, Clare; Hogg, William; Papadakis, Sophia; Dojeiji, Laurie; Russell, Grant; Akbari, Ayub; Pipe, Andrew; Higginson, Lyall

2011-01-01

Abstract Problem addressed A well documented gap remains between evidence and practice for clinical practice guidelines in cardiovascular disease (CVD) care. Objective of program As part of the Champlain CVD Prevention Strategy, practitioners in the Champlain District of Ontario launched a large quality-improvement initiative that focused on increasing the uptake in primary care practice settings of clinical guidelines for heart disease, stroke, diabetes, and CVD risk factors. Program description The Champlain Primary Care CVD Prevention and Management Guideline is a desktop resource for primary care clinicians working in the Champlain District. The guideline was developed by more than 45 local experts to summarize the latest evidence-based strategies for CVD prevention and management, as well as to increase awareness of local community-based programs and services. Conclusion Evidence suggests that tailored strategies are important when implementing specific practice guidelines. This article describes the process of creating an integrated clinical guideline for improvement in the delivery of cardiovascular care. PMID:21673196

Process simulation for advanced composites production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allendorf, M.D.; Ferko, S.M.; Griffiths, S.

1997-04-01

The objective of this project is to improve the efficiency and lower the cost of chemical vapor deposition (CVD) processes used to manufacture advanced ceramics by providing the physical and chemical understanding necessary to optimize and control these processes. Project deliverables include: numerical process models; databases of thermodynamic and kinetic information related to the deposition process; and process sensors and software algorithms that can be used for process control. Target manufacturing techniques include CVD fiber coating technologies (used to deposit interfacial coatings on continuous fiber ceramic preforms), chemical vapor infiltration, thin-film deposition processes used in the glass industry, and coatingmore » techniques used to deposit wear-, abrasion-, and corrosion-resistant coatings for use in the pulp and paper, metals processing, and aluminum industries.« less

Effects of oxidative stress on fatty acid- and one-carbon-metabolism in psychiatric and cardiovascular disease comorbidity

PubMed Central

Assies, J; Mocking, R J T; Lok, A; Ruhé, H G; Pouwer, F; Schene, A H

2014-01-01

Objective Cardiovascular disease (CVD) is the leading cause of death in severe psychiatric disorders (depression, schizophrenia). Here, we provide evidence of how the effects of oxidative stress on fatty acid (FA) and one-carbon (1-C) cycle metabolism, which may initially represent adaptive responses, might underlie comorbidity between CVD and psychiatric disorders. Method We conducted a literature search and integrated data in a narrative review. Results Oxidative stress, mainly generated in mitochondria, is implicated in both psychiatric and cardiovascular pathophysiology. Oxidative stress affects the intrinsically linked FA and 1-C cycle metabolism: FAs decrease in chain length and unsaturation (particularly omega-3 polyunsaturated FAs), and lipid peroxidation products increase; the 1-C cycle shifts from the methylation to transsulfuration pathway (lower folate and higher homocysteine and antioxidant glutathione). Interestingly, corresponding alterations were reported in psychiatric disorders and CVD. Potential mechanisms through which FA and 1-C cycle metabolism may be involved in brain (neurocognition, mood regulation) and cardiovascular system functioning (inflammation, thrombosis) include membrane peroxidizability and fluidity, eicosanoid synthesis, neuroprotection and epigenetics. Conclusion While oxidative-stress-induced alterations in FA and 1-C metabolism may initially enhance oxidative stress resistance, persisting chronically, they may cause damage possibly underlying (co-occurrence of) psychiatric disorders and CVD. This might have implications for research into diagnosis and (preventive) treatment of (CVD in) psychiatric patients. PMID:24649967

Low-temperature graphene synthesis using microwave plasma CVD

NASA Astrophysics Data System (ADS)

Yamada, Takatoshi; Kim, Jaeho; Ishihara, Masatou; Hasegawa, Masataka

2013-02-01

The graphene chemical vapour deposition (CVD) technique at substrate temperatures around 300 °C by a microwave plasma sustained by surface waves (surface wave plasma chemical vapour deposition, SWP-CVD) is discussed. A low-temperature, large-area and high-deposition-rate CVD process for graphene films was developed. It was found from Raman spectra that the deposited films on copper (Cu) substrates consisted of high-quality graphene flakes. The fabricated graphene transparent conductive electrode showed uniform optical transmittance and sheet resistance, which suggests the possibility of graphene for practical electrical and optoelectronic applications. It is intriguing that graphene was successfully deposited on aluminium (Al) substrates, for which we did not expect the catalytic effect to decompose hydrocarbon and hydrogen molecules. We developed a roll-to-roll SWP-CVD system for continuous graphene film deposition towards industrial mass production. A pair of winder and unwinder systems of Cu film was installed in the plasma CVD apparatus. Uniform Raman spectra were confirmed over the whole width of 297 mm of Cu films. We successfully transferred the deposited graphene onto PET films, and confirmed a transmittance of about 95% and a sheet resistance of less than 7 × 105 Ω/sq.

A systematic review and appraisal of methods of developing and validating lifestyle cardiovascular disease risk factors questionnaires.

PubMed

Nse, Odunaiya; Quinette, Louw; Okechukwu, Ogah

2015-09-01

Well developed and validated lifestyle cardiovascular disease (CVD) risk factors questionnaires is the key to obtaining accurate information to enable planning of CVD prevention program which is a necessity in developing countries. We conducted this review to assess methods and processes used for development and content validation of lifestyle CVD risk factors questionnaires and possibly develop an evidence based guideline for development and content validation of lifestyle CVD risk factors questionnaires. Relevant databases at the Stellenbosch University library were searched for studies conducted between 2008 and 2012, in English language and among humans. Using the following databases; pubmed, cinahl, psyc info and proquest. Search terms used were CVD risk factors, questionnaires, smoking, alcohol, physical activity and diet. Methods identified for development of lifestyle CVD risk factors were; review of literature either systematic or traditional, involvement of expert and /or target population using focus group discussion/interview, clinical experience of authors and deductive reasoning of authors. For validation, methods used were; the involvement of expert panel, the use of target population and factor analysis. Combination of methods produces questionnaires with good content validity and other psychometric properties which we consider good.

Measuring Physical Activity in Outdoor Community Recreational Environments: Implications for Research, Policy, and Practice.

PubMed

Aytur, Semra A; Jones, Sydney A; Stransky, Michelle; Evenson, Kelly R

2015-01-01

Chronic diseases such as cardiovascular disease (CVD) are major contributors to escalating health care costs in the USA. Physical activity is an important protective factor against CVD, and the National Prevention Strategy recognizes active living (defined as a way of life that integrates physical activity into everyday routines) as a priority for improving the nation's health. This paper focuses on developing more inclusive measures of physical activity in outdoor community recreational environments, specifically parks and trails, to enhance their usability for at-risk populations such as persons with mobility limitations. We develop an integrated conceptual framework for measuring physical activity in outdoor community recreational environments, describe examples of evidence-based tools for measuring physical activity in these settings, and discuss strategies to improve measurement of physical activity for persons with mobility limitations. Addressing these measurement issues is critically important to making progress towards national CVD goals pertaining to active community environments.

Postmortem heart weight: relation to body size and effects of cardiovascular disease and cancer.

PubMed

Kumar, Neena Theresa; Liestøl, Knut; Løberg, Else Marit; Reims, Henrik Mikael; Mæhlen, Jan

2014-01-01

Gender, body weight, and cardiovascular disease (CVD) are all variables known to influence human heart weight. The impact of cancer is less studied, and the influence of age is not unequivocal. We aimed to describe the relationship between body size and heart weight in a large autopsy cohort and to compare heart weight in patients with cancer, CVD, and other diseases. Registered information, including cause of death, evidence of cancer and/or CVD, heart weight, body weight, and height, was extracted from the autopsy reports of 1410 persons (805 men, mean age 66.5 years and 605 women, mean age 70.6 years). The study population was divided in four groups according to cause of death; cancer (n=349), CVD (n=470), mixed group who died from cancer and CVD and/or lung disease (n=263), and a reference group with patients who did not die from any of these conditions (n=328). In this last group, heart weight correlated only slightly better with body surface area than body weight, and nomograms based on body weight are presented. Compared to the reference group (mean heart weight: 426 g and 351 g in men and women, respectively), heart weight was significantly lower (men: P<.05, women: P<.001) in cancer patients (men: 392 g, women: 309 g) and higher (P<.001) in patients who died from CVD (men: 550 g, women: 430 g). Similar results were obtained in linear regression models adjusted for body weight and age. Among CVD, heart valve disease had the greatest impact on heart weight, followed by old myocardial infarction, coronary atherosclerosis, and hypertension. Absolute heart weight decreased with age, but we demonstrated an increase relative to body weight. The weight of the human heart is influenced by various disease processes, in addition to body weight, gender, and age. While the most prevalent types of CVD are associated with increased heart weight, patients who die from cancer have lower average heart weight than other patient groups. The latter finding, however, is diminished when adjusting for body weight. The present study demonstrates that the weight of the human heart is influenced by various disease processes like cancer and CVD, in addition to body weight, gender and, possibly, age. © 2013.

Optimal Magnetorheological Fluid for Finishing of Chemical-Vapor-Deposited Zinc Sulfide

NASA Astrophysics Data System (ADS)

Salzman, Sivan

Magnetorheological finishing (MRF) of polycrystalline, chemical-vapor- deposited zinc sulfide (ZnS) optics leaves visible surface artifacts known as "pebbles". These artifacts are a direct result of the material's inner structure that consists of cone-like features that grow larger (up to a few millimeters in size) as deposition takes place, and manifest on the top deposited surface as "pebbles". Polishing the pebble features from a CVD ZnS substrate to a flat, smooth surface to below 10 nm root-mean-square is challenging, especially for a non-destructive polishing process such as MRF. This work explores ways to improve the surface finish of CVD ZnS processed with MRF through modification of the magnetorheological (MR) fluid's properties. A materials science approach is presented to define the anisotropy of CVD ZnS through a combination of chemical and mechanical experiments and theoretical predictions. Magnetorheological finishing experiments with single crystal samples of ZnS, whose cuts and orientations represent most of the facets known to occur in the polycrystalline CVD ZnS, were performed to explore the influence of material anisotropy on the material removal rate during MRF. By adjusting the fluid's viscosity, abrasive type concentration, and pH to find the chemo-mechanical conditions that equalize removal rates among all single crystal facets during MRF, we established an optimized, novel MR formulation to polish CVD ZnS without degrading the surface finish of the optic.

Chemical vapor deposition modeling: An assessment of current status

NASA Technical Reports Server (NTRS)

Gokoglu, Suleyman A.

1991-01-01

The shortcomings of earlier approaches that assumed thermochemical equilibrium and used chemical vapor deposition (CVD) phase diagrams are pointed out. Significant advancements in predictive capabilities due to recent computational developments, especially those for deposition rates controlled by gas phase mass transport, are demonstrated. The importance of using the proper boundary conditions is stressed, and the availability and reliability of gas phase and surface chemical kinetic information are emphasized as the most limiting factors. Future directions for CVD are proposed on the basis of current needs for efficient and effective progress in CVD process design and optimization.

CVD Growth of Carbon Nanotubes: Structure, Catalyst, and Growth

NASA Technical Reports Server (NTRS)

Delzeit, Lance

2003-01-01

Carbon nanotubes (CNTs) exhibit extraordinary mechanical and unique electronic properties and hence have been receiving much attention in recent years for their potential in nanoelectronics, field emission devices, scanning probes, high strength composites and many more applications. Catalytic decomposition of hydrocarbon feedstock with the aid of supported transition metal catalysts - also known as chemical vapor deposition (CVD) - has become popular to produce single-walled and multi-walled nanotubes (SWNTs, MWNTs) and multiwalled nanofibers (MWNFs). The ability to grow CNTs on patterned substrates and in vertically aligned arrays, and the simplicity of the process, has made CVD growth of CNTs an attractive approach.

Cold Vacuum Drying facility civil structural system design description (SYS 06)

DOE Office of Scientific and Technical Information (OSTI.GOV)

PITKOFF, C.C.

This document describes the Cold Vacuum Drying (CVD) Facility civil - structural system. This system consists of the facility structure, including the administrative and process areas. The system's primary purpose is to provide for a facility to house the CVD process and personnel and to provide a tertiary level of containment. The document provides a description of the facility and demonstrates how the design meets the various requirements imposed by the safety analysis report and the design requirements document.

Chemical Vapor Deposited Zinc Sulfide. SPIE Press Monograph

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCloy, John S.; Tustison, Randal W.

2013-04-22

Zinc sulfide has shown unequaled utility for infrared windows that require a combination of long-wavelength infrared transparency, mechanical durability, and elevated-temperature performance. This book reviews the physical properties of chemical vapor deposited ZnS and their relationship to the CVD process that produced them. An in-depth look at the material microstructure is included, along with a discussion of the material's optical properties. Finally, because the CVD process itself is central to the development of this material, a brief history is presented.

Mirror Technology

NASA Technical Reports Server (NTRS)

1992-01-01

Under a NASA contract, MI-CVD developed a process for producing bulk silicon carbide by means of a chemical vapor deposition process. The technology allows growth of a high purity material with superior mechanical/thermal properties and high polishability - ideal for mirror applications. The company employed the technology to develop three research mirrors for NASA Langley and is now marketing it as CVD SILICON CARBIDE. Its advantages include light weight, thermal stability and high reflectivity. The material has nuclear research facility applications and is of interest to industrial users of high power lasers.

Engineering a mobile health tool for resource-poor settings to assess and manage cardiovascular disease risk: SMARThealth study.

PubMed

Raghu, Arvind; Praveen, Devarsetty; Peiris, David; Tarassenko, Lionel; Clifford, Gari

2015-04-29

The incidence of chronic diseases in low- and middle-income countries is rapidly increasing both in urban and rural regions. A major challenge for health systems globally is to develop innovative solutions for the prevention and control of these diseases. This paper discusses the development and pilot testing of SMARTHealth, a mobile-based, point-of-care Clinical Decision Support (CDS) tool to assess and manage cardiovascular disease (CVD) risk in resource-constrained settings. Through pilot testing, the preliminary acceptability, utility, and efficiency of the CDS tool was obtained. The CDS tool was part of an mHealth system comprising a mobile application that consisted of an evidence-based risk prediction and management algorithm, and a server-side electronic medical record system. Through an agile development process and user-centred design approach, key features of the mobile application that fitted the requirements of the end users and environment were obtained. A comprehensive analytics framework facilitated a data-driven approach to investigate four areas, namely, system efficiency, end-user variability, manual data entry errors, and usefulness of point-of-care management recommendations to the healthcare worker. A four-point Likert scale was used at the end of every risk assessment to gauge ease-of-use of the system. The system was field-tested with eleven village healthcare workers and three Primary Health Centre doctors, who screened a total of 292 adults aged 40 years and above. 34% of participants screened by health workers were identified by the CDS tool to be high CVD risk and referred to a doctor. In-depth analysis of user interactions found the CDS tool feasible for use and easily integrable into the workflow of healthcare workers. Following completion of the pilot, further technical enhancements were implemented to improve uptake of the mHealth platform. It will then be evaluated for effectiveness and cost-effectiveness in a cluster randomized controlled trial involving 54 southern Indian villages and over 16000 individuals at high CVD risk. An evidence-based CVD risk prediction and management tool was used to develop an mHealth platform in rural India for CVD screening and management with proper engagement of health care providers and local communities. With over a third of screened participants being high risk, there is a need to demonstrate the clinical impact of the mHealth platform so that it could contribute to improved CVD detection in high risk low resource settings.

Development, Testing, and Implementation of a Training Curriculum for Nonphysician Health Workers to Reduce Cardiovascular Disease.

PubMed

Khan, Maheer; Lamelas, Pablo; Musa, Hadi; Paty, Jared; McCready, Tara; Nieuwlaat, Robby; Ng, Eleonor; Lopez-Jaramillo, Patricio; Lopez-Lopez, Jose; Yusoff, Khalid; Majid, Fadhlina A; Ng, Kien Keat; Garis, Len; Onuma, Oyere; Yusuf, Salim; Schwalm, Jon-David

2018-01-10

Cardiovascular disease (CVD) is the leading cause of death worldwide. The need to address CVD is greatest in low- and middle-income countries where there is a shortage of trained health workers in CVD detection, prevention, and control. Based on the growing evidence that many elements of chronic disease management can be shifted to nonphysician health care workers (NPHW), the HOPE-4 (Heart Outcomes Prevention and Evaluation Program) aimed to develop, test, and implement a training curriculum on CVD prevention and control in Colombia, Malaysia, and low-resource settings in Canada. Curriculum development followed an iterative and phased approach where evidence-based guidelines, revised blood pressure treatment algorithms, and culturally relevant risk factor counseling were incorporated. Through a pilot-training process with high school students in Canada, the curriculum was further refined. Implementation of the curriculum in Colombia, Malaysia, and Canada occurred through partner organizations as the HOPE-4 team coordinated the program from Hamilton, Ontario, Canada. In addition to content on the burden of disease, cardiovascular system pathophysiology, and CVD risk factors, the curriculum also included evaluations such as module tests, in-class exercises, and observed structured clinical examinations, which were administered by the local partner organizations. These evaluations served as indicators of adequate uptake of curriculum content as well as readiness to work as an NPHW in the field. Overall, 51 NPHW successfully completed the training curriculum with an average score of 93.19% on module tests and 84.76% on the observed structured clinical examinations. Since implementation, the curriculum has also been adapted to the World Health Organization's HEARTS Technical Package, which was launched in 2016 to improve management of CVD in primary health care. The robust curriculum development, testing, and implementation process described affirm that NPHW in diverse settings can be trained in implementing measures for CVD prevention and control. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Chemical vapor deposition and characterization of polysilanes polymer based thin films and their applications in compound semiconductors and silicon devices

NASA Astrophysics Data System (ADS)

Oulachgar, El Hassane

As the semiconductors industry is moving toward nanodevices, there is growing need to develop new materials and thin films deposition processes which could enable strict control of the atomic composition and structure of thin film materials in order to achieve precise control on their electrical and optical properties. The accurate control of thin film characteristics will become increasingly important as the miniaturization of semiconductor devices continue. There is no doubt that chemical synthesis of new materials and their self assembly will play a major role in the design and fabrication of next generation semiconductor devices. The objective of this work is to investigate the chemical vapor deposition (CVD) process of thin film using a polymeric precursor as a source material. This process offers many advantages including low deposition cost, hazard free working environment, and most importantly the ability to customize the polymer source material through polymer synthesis and polymer functionalization. The combination between polymer synthesis and CVD process will enable the design of new generation of complex thin film materials with a wide range of improved chemical, mechanical, electrical and optical properties which cannot be easily achieved through conventional CVD processes based on gases and small molecule precursors. In this thesis we mainly focused on polysilanes polymers and more specifically poly(dimethylsilanes). The interest in these polymers is motivated by their distinctive electronic and photonic properties which are attributed to the delocalization of the sigma-electron along the Si-Si backbone chain. These characteristics make polysilane polymers very promising in a broad range of applications as a dielectric, a semiconductor and a conductor. The polymer-based CVD process could be eventually extended to other polymer source materials such as polygermanes, as well as and a variety of other inorganic and hybrid organic-inorganic polymers. This work has demonstrated that a polysilane polymeric source can be used to deposit a wide range of thin film materials exhibiting similar properties with conventional ceramic materials such as silicon carbide (SiC), silicon oxynitride (SiON), silicon oxycarbide (SiOC) silicon dioxide (SiO2) and silicon nitride (Si3N4). The strict control of the deposition process allows precise control of the electrical, optical and chemical properties of polymer-based thin films within a broad range. This work has also demonstrated for the first time that poly(dimethylsilmaes) polymers deposited by CVD can be used to effectively passivate both silicon and gallium arsenide MOS devices. This finding makes polymer-based thin films obtained by CVD very promising for the development of high-kappa dielectric materials for next generation high-mobility CMOS technology. Keywords. Thin films, Polymers, Vapor Phase Deposition, CVD, Nanodielectrics, Organosilanes, Polysilanes, GaAs Passivation, MOSFET, Silicon Oxynitride, Integrated Waveguide, Silicon Carbide, Compound Semiconductors.

Cardiovascular reactivity, stress, and physical activity

PubMed Central

Huang, Chun-Jung; Webb, Heather E.; Zourdos, Michael C.; Acevedo, Edmund O.

2013-01-01

Psychological stress has been proposed as a major contributor to the progression of cardiovascular disease (CVD). Acute mental stress can activate the sympathetic-adrenal-medullary (SAM) axis, eliciting the release of catecholamines (NE and EPI) resulting in the elevation of heart rate (HR) and blood pressure (BP). Combined stress (psychological and physical) can exacerbate these cardiovascular responses, which may partially contribute to the elevated risk of CVD and increased proportionate mortality risks experienced by some occupations (e.g., firefighting and law enforcement). Studies have supported the benefits of physical activity on physiological and psychological health, including the cardiovascular response to acute stress. Aerobically trained individuals exhibit lower sympathetic nervous system (e.g., HR) reactivity and enhanced cardiovascular efficiency (e.g., lower vascular reactivity and decreased recovery time) in response to physical and/or psychological stress. In addition, resistance training has been demonstrated to attenuate cardiovascular responses and improve mental health. This review will examine stress-induced cardiovascular reactivity and plausible explanations for how exercise training and physical fitness (aerobic and resistance exercise) can attenuate cardiovascular responses to stress. This enhanced functionality may facilitate a reduction in the incidence of stroke and myocardial infarction. Finally, this review will also address the interaction of obesity and physical activity on cardiovascular reactivity and CVD. PMID:24223557

The impact of a point-of-care testing device on CVD risk assessment completion in New Zealand primary-care practice: A cluster randomised controlled trial and qualitative investigation.

PubMed

Wells, Sue; Rafter, Natasha; Kenealy, Timothy; Herd, Geoff; Eggleton, Kyle; Lightfoot, Rose; Arcus, Kim; Wadham, Angela; Jiang, Yannan; Bullen, Chris

2017-01-01

To assess the effect of a point of care (POC) device for testing lipids and HbA1c in addition to testing by community laboratory facilities (usual practice) on the completion of cardiovascular disease (CVD) risk assessments in general practice. We conducted a pragmatic, cluster randomised controlled trial in 20 New Zealand general practices stratified by size and rurality and randomised to POC device plus usual practice or usual practice alone (controls). Patients aged 35-79 years were eligible if they met national guideline criteria for CVD risk assessment. Data on CVD risk assessments were aggregated using a web-based decision support programme common to each practice. Data entered into the on-line CVD risk assessment form could be saved pending blood test results. The primary outcome was the proportion of completed CVD risk assessments. Qualitative data on practice processes for CVD risk assessment and feasibility of POC testing were collected at the end of the study by interviews and questionnaire. The POC testing was supported by a comprehensive quality assurance programme. A CVD risk assessment entry was recorded for 7421 patients in 10 POC practices and 6217 patients in 10 control practices; 99.5% of CVD risk assessments had complete data in both groups (adjusted odds ratio 1.02 [95%CI 0.61-1.69]). There were major external influences that affected the trial: including a national performance target for CVD risk assessment and changes to CVD guidelines. All practices had invested in systems and dedicated staff time to identify and follow up patients to completion. However, the POC device was viewed by most as an additional tool rather than as an opportunity to review practice work flow and leverage the immediate test results for patient education and CVD risk management discussions. Shortly after commencement, the trial was halted due to a change in the HbA1c test assay performance. The trial restarted after the manufacturing issue was rectified but this affected the end use of the device. Performance incentives and external influences were more powerful modifiers of practice behaviours than the POC device in relation to CVD risk assessment completion. The promise of combining risk assessment, communication and management within one consultation was not realised. With shifts in policy focus, the utility of POC devices for patient engagement in CVD preventive care may be demonstrated if fully integrated into the clinical setting. Australian New Zealand Clinical Trials Registry ACTRN12613000607774.

Influence of CVD diamond tips and Er:YAG laser irradiation on bonding of different adhesive systems to dentin.

PubMed

da Silva, Melissa Aline; Di Nicolo, Rebeca; Barcellos, Daphne Camara; Batista, Graziela Ribeiro; Pucci, Cesar Rogerio; Rocha Gomes Torres, Carlos; Borges, Alessandra Bühler

2013-01-01

The aim of this study was to compare the microtensile bond strength of three adhesive systems, using different methods of dentin preparation. A hundred and eight bovine teeth were used. The dentin from buccal face was exposed and prepared with three different methods, divided in 3 groups: Group 1 (DT)- diamond tip on a high-speed handpiece; Group 2 (CVD)-CVD tip on a ultrasonic handpiece; Group 3 (LA)-Er: YAG laser. The teeth were divided into 3 subgroups, according adhesive systems used: Subgroup 1-Adper Single Bond Plus/3M ESPE (SB) total-etch adhesive; Subgroup 2-Adper Scotchbond SE/3M ESPE (AS) selfetching adhesive; Subgroup 3-Clearfil SE Bond/Kuraray (CS) selfetching adhesive. Blocks of composite (Filtek Z250-3M ESPE) 4 mm high were built up and specimens were stored in deionized water for 24 hours at 37°C. Serial mesiodistal and buccolingual cuts were made and stick-like specimens were obtained, with transversal section of 1.0 mm(2). The samples were submitted to microtensile test at 1 mm/min and load of 10 kg in a universal testing machine. Data (MPa) were subjected to ANOVA and Tukey's tests (p < 0.05). Surface treatment with Diamond or CVD tips associated with Clearfil SE Bond adhesive produced significantly lower bond strength values compared to other groups. Surface treatment with Er: YAG laser associated with Single Bond Plus or Clearfil SE Bond adhesives and surface treatment with CVD tip associated with Adper Scotchbond SE adhesive produced significantly lower bond strength values compared to surface treatment with diamond or CVD tips associated with Single Bond Plus or Adper Scotchbond SE adhesives. Interactions between laser and the CVD tip technologies and the different adhesive systems can produce a satisfactory bonding strength result, so that these associations may be beneficial and enhance the clinical outcomes.

Material removal characteristics of orthogonal velocity polishing tool for efficient fabrication of CVD SiC mirror surfaces

NASA Astrophysics Data System (ADS)

Seo, Hyunju; Han, Jeong-Yeol; Kim, Sug-Whan; Seong, Sehyun; Yoon, Siyoung; Lee, Kyungmook; Lee, Haengbok

2015-09-01

Today, CVD SiC mirrors are readily available in the market. However, it is well known to the community that the key surface fabrication processes and, in particular, the material removal characteristics of the CVD SiC mirror surface varies sensitively depending on the shop floor polishing and figuring variables. We investigated the material removal characteristics of CVD SiC mirror surfaces using a new and patented polishing tool called orthogonal velocity tool (OVT) that employs two orthogonal velocity fields generated simultaneously during polishing and figuring machine runs. We built an in-house OVT machine and its operating principle allows for generation of pseudo Gaussian shapes of material removal from the target surface. The shapes are very similar to the tool influence functions (TIFs) of other polishing machine such as IRP series polishing machines from Zeeko. Using two CVD SiC mirrors of 150 mm in diameter and flat surface, we ran trial material removal experiments over the machine run parameter ranges from 12.901 to 25.867 psi in pressure, 0.086 m/sec to 0.147 m/sec in tool linear velocity, and 5 to 15 sec in dwell time. An in-house developed data analysis program was used to obtain a number of Gaussian shaped TIFs and the resulting material removal coefficient varies from 3.35 to 9.46 um/psi hour m/sec with the mean value to 5.90 ± 1.26(standard deviation). We report the technical details of the new OVT machine, of the data analysis program, of the experiments and the results together with the implications to the future development of the OVT machine and process for large CVD SiC mirror surfaces.

Report of work done for technical assistance agreement 1269 between Sandia National Laboratories and the Watkins-Johnson Company: Chemical reaction mechanisms for computational models of SiO{sub 2} CVD

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ho, P.; Johannes, J.; Kudriavtsev, V.

The use of computational modeling to improve equipment and process designs for chemical vapor deposition (CVD) reactors is becoming increasingly common. Commercial codes are available that facilitate the modeling of chemically-reacting flows, but chemical reaction mechanisms must be separately developed for each system of interest. One f the products of the Watkins-Johnson Company (WJ) is a reactor marketed to semiconductor manufacturers for the atmospheric-pressure chemical vapor deposition (APCVD) of silicon oxide films. In this process, TEOS (tetraethoxysilane, Si(OC{sub 2}H{sub 5}){sub 4}) and ozone (O{sub 3}) are injected (in nitrogen and oxygen carrier gases) over hot silicon wafers that are beingmore » carried through the system on a moving belt. As part of their equipment improvement process, WJ is developing computational models of this tool. In this effort, they are collaborating with Sandia National Laboratories (SNL) to draw on Sandia`s experience base in understanding and modeling the chemistry of CVD processes.« less

A Community-Based Participatory Approach to Personalized, Computer-Generated Nutrition Feedback Reports: The Healthy Environments Partnership

PubMed Central

Kannan, Srimathi; Schulz, Amy; Israel, Barbara; Ayra, Indira; Weir, Sheryl; Dvonch, Timothy J.; Rowe, Zachary; Miller, Patricia; Benjamin, Alison

2008-01-01

Background Computer tailoring and personalizing recommendations for dietary health-promoting behaviors are in accordance with community-based participatory research (CBPR) principles, which emphasizes research that benefits the participants and community involved. Objective To describe the CBPR process utilized to computer-generate and disseminate personalized nutrition feedback reports (NFRs) for Detroit Healthy Environments Partnership (HEP) study participants. METHODS The CBPR process included discussion and feedback from HEP partners on several draft personalized reports. The nutrition feedback process included defining the feedback objectives; prioritizing the nutrients; customizing the report design; reviewing and revising the NFR template and readability; producing and disseminating the report; and participant follow-up. Lessons Learned Application of CBPR principles in designing the NFR resulted in a reader-friendly product with useful recommendations to promote heart health. Conclusions A CBPR process can enhance computer tailoring of personalized NFRs to address racial and socioeconomic disparities in cardiovascular disease (CVD). PMID:19337572

Risk of Cardiovascular Disease from Cumulative Cigarette Use and the Impact of Smoking Intensity.

PubMed

Lubin, Jay H; Couper, David; Lutsey, Pamela L; Woodward, Mark; Yatsuya, Hiroshi; Huxley, Rachel R

2016-05-01

Relative risks (RRs) for cardiovascular disease (CVD) by smoking rate exhibit a concave pattern, with RRs in low rate smokers exceeding a linear extrapolation from higher rate smokers. However, cigarettes/day does not by itself fully characterize smoking-related risks. A reexamination of the concave pattern using a comprehensive representation of smoking may enhance insights. Data were from the Atherosclerosis Risk in Communities (ARIC) Study, a prospective cohort enrolled in four areas of the US in 1987-1989. Follow-up was through 2008. Analyses included 14,233 participants, 245,915 person-years, and 3,411 CVD events. The concave RRs with cigarettes/day were consistent with cigarettes/day modifying a linear RR association of pack-years with CVD (i.e., strength of the pack-years association depended on cigarettes/day, indicating that the manner of pack-years accrual impacted risk). Smoking fewer cigarettes/day for longer duration was more deleterious than smoking more cigarettes/day for shorter duration (P < 0.01). For 50 pack-years (365,000 cigarettes), estimated RRs of CVD were 2.1 for accrual at 20 cigarettes/day and 1.6 for accrual at 50 cigarettes/day. Years since smoking cessation did not alter the diminishing strength of association with increasing cigarettes/day. Analyses that accounted for competing risks did not affect findings. Pack-years remained the primary determinant of smoking-related CVD risk; however, accrual influenced RRs. For equal pack-years, smoking fewer cigarettes/day for longer duration was more deleterious than smoking more cigarettes/day for shorter duration. This observation provides clues to better understanding the biological mechanisms, and reinforces the importance of cessation rather than smoking less to reduce CVD risk.

Status of the secondary mirrors (M2) for the Gemini 8-m telescopes

NASA Astrophysics Data System (ADS)

Knohl, Ernst-Dieter; Schoeppach, Armin; Pickering, Michael A.

1998-08-01

The 1-m diameter lightweight secondary mirrors (M2) for the Gemini 8-m telescopes will be the largest CVD-SiC mirrors ever produced. The design and manufacture of these mirrors is a very challenging task. In this paper we will discuss the mirror design, structural and mechanical analysis, and the CVD manufacturing process used to produce the mirror blanks. The lightweight design consist of a thin faceplate (4-mm) and triangular backstructure cells with ribs of varying heights. The main drivers in the design were weight (40 kg) and manufacturing limitations imposed on the backstructure cells and mirror mounts. Finite element modeling predicts that the mirror design will meet all of the Gemini M2 requirements for weight, mechanical integrity, resonances, and optical performance. Special design considerations were necessary to avoid stress concentration in the mounting areas and to meet the requirement that the mirror survive an 8-g earthquake. The highest risk step in the mirror blank manufacturing process is the near-net-shape CVD deposition of the thin, curved faceplate. Special tooling and procedures had to be developed to produce faceplates free of fractures, cracks, and stress during the cool-down from deposition temperature (1350 C) to room temperature. Due to time delay with the CVD manufacturing process in the meantime a backup solution from Zerodur has been started. This mirror is now in the advanced polishing process. Because the design of both mirrors is very similar an excellent comparison of both solutions is possible.

Synthesis of Sr2Si5N8:Ce3+ phosphors for white LEDs via an efficient chemical deposition

PubMed Central

Yang, Che-Yuan; Som, Sudipta; Das, Subrata; Lu, Chung-Hsin

2017-01-01

Novel chemical vapor deposition (CVD) process was successfully developed for the growth of Sr2Si5N8:Ce3+ phosphors with elevated luminescent properties. Metallic strontium was used as a vapor source for producing Sr3N2 vapor to react with Si3N4 powder via a homogeneous gas-solid reaction. The phosphors prepared via the CVD process showed high crystallinity, homogeneous particle size ranging from 8 to 10 μm, and high luminescence properties. In contrast, the phosphors prepared via the conventional solid-state reaction process exhibited relative low crystallinity, non-uniform particle size in the range of 0.5–5 μm and relatively lower luminescent properties than the phosphors synthesized via the CVD process. Upon the blue light excitation, Sr2−xCexSi5N8 phosphors exhibited a broad yellow band. A red shift of the emission band from 535 to 556 nm was observed with the increment in the doping amount of Ce3+ ions from x = 0.02 to x = 0.10. The maximum emission was observed at x = 0.06, and the external and internal quantum efficiencies were calculated to be 51% and 71%, respectively. Furthermore, the CVD derived optimum Sr1.94Ce0.06Si5N8 phosphor exhibited sufficient thermal stability for blue-LEDs and the activation energy was calculated to be 0.33 eV. The results demonstrate a potential synthesis process for nitride phosphors suitable for light emitting diodes. PMID:28361999

Synthesis of Sr2Si5N8:Ce3+ phosphors for white LEDs via an efficient chemical deposition

NASA Astrophysics Data System (ADS)

Yang, Che-Yuan; Som, Sudipta; Das, Subrata; Lu, Chung-Hsin

2017-03-01

Novel chemical vapor deposition (CVD) process was successfully developed for the growth of Sr2Si5N8:Ce3+ phosphors with elevated luminescent properties. Metallic strontium was used as a vapor source for producing Sr3N2 vapor to react with Si3N4 powder via a homogeneous gas-solid reaction. The phosphors prepared via the CVD process showed high crystallinity, homogeneous particle size ranging from 8 to 10 μm, and high luminescence properties. In contrast, the phosphors prepared via the conventional solid-state reaction process exhibited relative low crystallinity, non-uniform particle size in the range of 0.5-5 μm and relatively lower luminescent properties than the phosphors synthesized via the CVD process. Upon the blue light excitation, Sr2-xCexSi5N8 phosphors exhibited a broad yellow band. A red shift of the emission band from 535 to 556 nm was observed with the increment in the doping amount of Ce3+ ions from x = 0.02 to x = 0.10. The maximum emission was observed at x = 0.06, and the external and internal quantum efficiencies were calculated to be 51% and 71%, respectively. Furthermore, the CVD derived optimum Sr1.94Ce0.06Si5N8 phosphor exhibited sufficient thermal stability for blue-LEDs and the activation energy was calculated to be 0.33 eV. The results demonstrate a potential synthesis process for nitride phosphors suitable for light emitting diodes.

The influence of socioeconomic factors on cardiovascular disease risk factors in the context of economic development in the Samoan archipelago.

PubMed

Ezeamama, Amara E; Viali, Satupaitea; Tuitele, John; McGarvey, Stephen T

2006-11-01

Early in economic development there are positive associations between socioeconomic status (SES) and cardiovascular disease (CVD) risk factors, and in the most developed market economy societies there are negative associations. The purpose of this report is to describe cross-sectional and longitudinal associations between indicators of SES and CVD risk factors in a genetically homogenous population of Samoans at different levels of economic development. At baseline 1289 participants 25-58yrs, and at 4-year follow-up, 963 participants were studied in less economically developed Samoa and in more developed American Samoa. SES was assessed by education, occupation, and material lifestyle at baseline. The CVD risk factors, obesity, type-2 diabetes and hypertension were measured at baseline and 4-year follow-up, and an index of any incident CVD risk factor at follow-up was calculated. Sex and location (Samoa and American Samoa) specific multivariable logistic regression models were used to test for relationships between SES and CVD risk factors at baseline after adjustment for age and the other SES indicators. In addition an ordinal SES index was constructed for each individual based on all three SES indicators, and used in a multivariable model to estimate the predicted probability of CVD risk factors across the SES index for the two locations. In both the models using specific SES measures and CVD risk factor outcomes, and the models using the ordinal SES index and predicted probabilities of CVD risk factors, we detected a pattern of high SES associated with: (1) elevated odds of CVD risk factors in less developed Samoa, and (2) decreased odds of CVD risk factors in more developed American Samoa. We conclude that the pattern of inverse associations between SES and CVD risk factors in Samoa and direct associations in American Samoa is attributable to the heterogeneity across the Samoas in specific exposures to social processes of economic development and the natural history of individual CVD risk factors. The findings suggest that interventions on non-communicable diseases in the Samoas must be devised based on the level of economic development, the socio-economic context of risk factor exposures, and individual characteristics such as age, sex and education level.

Cardiovascular disease prevention and lifestyle interventions: effectiveness and efficacy.

PubMed

Haskell, William L

2003-01-01

Over the past half century scientific data support the strong relationship between the way a person or population lives and their risk for developing or dying from cardiovascular disease (CVD). While heredity can be a major factor for some people, their personal health habits and environmental/cultural exposure are more important factors. CVD is a multifactor process that is contributed to by a variety of biological and behavioral characteristics of the person including a number of well-established and emerging risk factors. Not smoking, being physically active, eating a heart healthy diet, staying reasonably lean, and avoiding major stress and depression are the major components of an effective CVD prevention program. For people at high risk of CVD, medications frequently need to be added to a healthy lifestyle to minimize their risk of a heart attack or stroke, particularly in persons with conditions such as hypertension, hypercholesterolemia, or hyperglycemia. Maintaining an effective CVD prevention program in technologically advanced societies cannot be achieved by many high-risk persons without effective and sustained support from a well-organized health care system. Nurse-provided or nurse-coordinated care management programs using an integrated or multifactor approach have been highly effective in reducing CVD morbidity and mortality of high-risk persons.

Low-temperature-grown continuous graphene films from benzene by chemical vapor deposition at ambient pressure

NASA Astrophysics Data System (ADS)

Jang, Jisu; Son, Myungwoo; Chung, Sunki; Kim, Kihyeun; Cho, Chunhum; Lee, Byoung Hun; Ham, Moon-Ho

2015-12-01

There is significant interest in synthesizing large-area graphene films at low temperatures by chemical vapor deposition (CVD) for nanoelectronic and flexible device applications. However, to date, low-temperature CVD methods have suffered from lower surface coverage because micro-sized graphene flakes are produced. Here, we demonstrate a modified CVD technique for the production of large-area, continuous monolayer graphene films from benzene on Cu at 100-300 °C at ambient pressure. In this method, we extended the graphene growth step in the absence of residual oxidizing species by introducing pumping and purging cycles prior to growth. This led to continuous monolayer graphene films with full surface coverage and excellent quality, which were comparable to those achieved with high-temperature CVD; for example, the surface coverage, transmittance, and carrier mobilities of the graphene grown at 300 °C were 100%, 97.6%, and 1,900-2,500 cm2 V-1 s-1, respectively. In addition, the growth temperature was substantially reduced to as low as 100 °C, which is the lowest temperature reported to date for pristine graphene produced by CVD. Our modified CVD method is expected to allow the direct growth of graphene in device manufacturing processes for practical applications while keeping underlying devices intact.

Training community health workers to screen for cardiovascular disease risk in the community: experiences from Cape Town, South Africa

PubMed Central

Puoane, Thandi; Abrahams-Gessel, Shafika; Gaziano, Thomas A; Levitt, Naomi

2017-01-01

Summary Introduction This article describes a training process to equip community health workers (CHWs) with knowledge and skills to identify individuals at high risk for cardiovascular disease (CVD) in a township in Cape Town. Methods: CHWs were employed by a non-governmental organisation (NGO) primarily focusing on non-communicable diseases (NCDs). They were trained in the theory of CVD, including physiological changes and related risk factors and in obtaining anthropometric and blood pressure measurements. Pre- and post-training tests assessed learning needs and the effectiveness of imparting knowledge about CVD, respectively. Results: Training increased knowledge about CVD risk factors. CHWs were able to screen and identify those at risk for CVD and refer them to health professionals for validation of scores. The initial one-week training was too short, given the amount of information covered. Some CHWs had difficulty with English as the primary instruction medium and as the only language in which tests were offered. Conclusion: Although CHWs could be trained to screen for CVD risk, increased training time was required to impart the knowledge. The language used during training and testing presented challenges for those trainees whose dominant, spoken language was not English. PMID:28759089

Revealing the microscopic CVD growth mechanism of MoSe2 and the role of hydrogen gas during the growth procedure.

PubMed

Wang, Hulian; Zhu, Dancheng; Jiang, Feng; Zhao, Pei; Wang, Hongtao; Zhang, Ze; Chen, Xin; Jin, Chuanhong

2018-08-03

Understanding the microscopic mechanisms for the nucleation and growth of two-dimensional molybdenum diselenide (2D MoSe 2 ) via chemical vapor deposition (CVD) is crucial towards the precisely controlled growth of the 2D material. In this work, we employed a joint use of transmission electron microscopy and CVD, in which the 2D MoSe 2 were directly grown on a graphene membrane based on grids, that enables the microstructural characterization of as-grown MoSe 2 flakes. We further explore the role of hydrogen gas and find: in an argon ambient, the primary products are few-layer MoSe 2 flakes, along with MoO x nanoparticles; while with the introduction of H 2 , single-layer MoSe 2 became the dominant product during the CVD growth. Quantitative analysis of the effects of H 2 flow rate on the flake sizes, and areal coverage was also given. Nevertheless, we further illuminated the evolution of shape morphology and edge structures of single-layer MoSe 2 , and proposed the associated growth routes during a typical CVD process.

[Time analysis of mortality from cerebrovascular diseases in Andalucia (1975-1999)].

PubMed

Cayuela-Domínguez, A; Rodríguez-Domínguez, S; Iglesias-Bonilla, P; Mir-Rivera, P; Martínez-Fernández, E

In previous publications we analysed the tendency of mortality from cerebrovascular diseases (CVD) in Andalusia over the period 1975-1992, and we observed a marked decrease in the mortality rates in both sexes. AIMS. To describe the evolution of mortality from CVD in Andalusia throughout the period 1975-1999. Deaths from CVD over the period 1975 1999 were obtained from the Instituto Andaluz de Estadística. We employed the direct method of standardisation of rates (world standard population). The rates were subjected to logarithmic transformations and the regression lines were adjusted. A considerable decrease was found in the rates: 3.9% in males and 4.0% in females. The drop in truncated rates (35 64 years old) was greater in women ( 5.9%) than in men ( 4.3%). Our work shows a marked and continuous decrease in mortality from CVD in Andalusia (1975-1999). In accordance with the process of aging of the population, the magnitude of CVD measured in terms of deaths, invalidity and health costs still represents a great challenge for preventative and health care policies.

Study of Silicidation Process of Tungsten Catalyzer during Silicon Film Deposition in Catalytic Chemical Vapor Deposition

NASA Astrophysics Data System (ADS)

Honda, Kazuhiro; Ohdaira, Keisuke; Matsumura, Hideki

2008-05-01

In catalytic chemical vapor deposition (Cat-CVD), often called hot-wire CVD, source gases are decomposed by catalytic cracking reactions with heated catalyzing metal wires. In the case of silicon (Si) film deposition, such metal wires are often converted to silicide, which shortens the lifetime of catalyzing wires. As a catalyzer, tungsten (W) is widely used. Thus, the process of silicidation of a W catalyzer at temperatures over 1650 °C, which is the temperature used in Cat-CVD for Si film deposition, was studied extensively in various experiments. It is found that two phases of tungsten-silicide, WSi2 and W5Si3, are formed at this temperature, and that the radiation emissivity of WSi2 is 1.2 to 1.7 times higher than that of W5Si3 and pure W. The increase of surface emissivity due to the formation of WSi2 decreases the catalyzer surface temperature which induces further growth of the tungsten-silicide layer. It is also found that the suppression of WSi2 formation by elevating catalyzer temperatures over 1750 °C is a key to extending the lifetime of the W catalyzer in Cat-CVD.

High prevalence of cardiovascular disease in South Asians: Central role for brown adipose tissue?

PubMed

Boon, Mariëtte R; Bakker, Leontine E H; van der Linden, Rianne A D; van Ouwerkerk, Antoinette F; de Goeje, Pauline L; Counotte, Jacqueline; Jazet, Ingrid M; Rensen, Patrick C N

2015-01-01

Cardiovascular disease (CVD) is the leading cause of death in modern society. Interestingly, the risk of developing CVD varies between different ethnic groups. A particularly high risk is faced by South Asians, representing over one-fifth of the world's population. Here, we review potential factors contributing to the increased cardiovascular risk in the South Asian population and discuss novel therapeutic strategies based on recent insights. In South Asians, classical ('metabolic') risk factors associated with CVD are highly prevalent and include central obesity, insulin resistance, type 2 diabetes, and dyslipidemia. A contributing factor that may underlie the development of this disadvantageous metabolic phenotype is the presence of a lower amount of brown adipose tissue (BAT) in South Asian subjects, resulting in lower energy expenditure and lower lipid oxidation and glucose uptake. As it has been established that the increased prevalence of classical risk factors in South Asians cannot fully explain their increased risk for CVD, other non-classical risk factors must underlie this residual risk. In South Asians, the prevalence of "inflammatory" risk factors including visceral adipose tissue inflammation, endothelial dysfunction, and HDL dysfunction are higher compared with Caucasians. We conclude that a potential novel therapy to lower CVD risk in the South Asian population is to enhance BAT volume or its activity in order to diminish classical risk factors. Furthermore, anti-inflammatory therapy may lower non-classical risk factors in this population and the combination of both strategies may be especially effective.

TACKLING THE GROWING DIABETES BURDEN IN SUB-SAHARAN AFRICA: A FRAMEWORK FOR ENHANCING OUTCOMES IN STROKE PATIENTS

PubMed Central

Ovbiagele, Bruce

2014-01-01

According to the World Health Organization (WHO), more than 80% of worldwide diabetes (DM)-related deaths presently occur in low- and middle- income countries (LMIC), and left unchecked these DM-related deaths will likely double over the next 20 years. Cardiovascular disease (CVD) is the most prevalent and detrimental complication of DM: doubling the risk of CVD events (including stroke) and accounting for up to 80% of DM-related deaths. Given the aforementioned, interventions targeted at reducing CVD risk among people with DM are integral to limiting DM-related morbidity and mortality in LMIC, a majority of which are located in Sub-Saharan Africa (SSA). However, SSA is contextually unique: socioeconomic obstacles, cultural barriers, under-diagnosis, uncoordinated care, and shortage of physicians currently limit the capacity of SSA countries to implement CVD prevention among people with DM in a timely and sustainable manner. This article proposes a theory-based framework for conceptualizing integrated protocol-driven risk factor patient self-management interventions that could be adopted or adapted in future studies among hospitalized stroke patients with DM encountered in SSA. These interventions include systematic health education at hospital discharge, use of post-discharge trained community lay navigators, implementation of nurse-led group clinics and administration of health technology (personalized phone text messaging and home tele-monitoring), all aimed at increasing patient self-efficacy and intrinsic motivation for sustained adherence to therapies proven to reduce CVD event risk. PMID:25475149

Ion beam figuring of CVD silicon carbide mirrors

NASA Astrophysics Data System (ADS)

Gailly, P.; Collette, J.-P.; Fleury Frenette, K.; Jamar, C.

2017-11-01

Optical and structural elements made of silicon carbide are increasingly found in space instruments. Chemical vapor deposited silicon carbide (CVD-SiC) is used as a reflective coating on SiC optics in reason of its good behavior under polishing. The advantage of applying ion beam figuring (IBF) to CVD-SiC over other surface figure-improving techniques is discussed herein. The results of an IBF sequence performed at the Centre Spatial de Liège on a 100 mm CVD-SiC mirror are reported. The process allowed to reduce the mirror surface errors from 243 nm to 13 nm rms . Beside the surface figure, roughness is another critical feature to consider in order to preserve the optical quality of CVD-SiC . Thus, experiments focusing on the evolution of roughness were performed in various ion beam etching conditions. The roughness of samples etched at different depths down to 3 ≠m was determined with an optical profilometer. These measurements emphasize the importance of selecting the right combination of gas and beam energy to keep roughness at a low level. Kaufman-type ion sources are generally used to perform IBF but the performance of an end-Hall ion source in figuring CVD-SiC mirrors was also evaluated in this study. In order to do so, ion beam etching profiles obtained with the end-Hall source on CVD-SiC were measured and used as a basis for IBF simulations.

Low Temperature Graphene Growth and Its Applications in Electronic and Optical Devices

NASA Astrophysics Data System (ADS)

Chugh, Sunny

Graphene, a two dimensional allotrope of carbon in a honeycomb lattice, has gathered wide attention due to its excellent electrical, thermal, optical and mechanical properties. It has extremely high electron/hole mobility, very high thermal conductivity and fascinating optical properties, and combined with its mechanical strength and elasticity, graphene is believed to find commercial applications in existing as well as novel technologies. One of the biggest reasons behind the rapid development in graphene research during the last decade is the fact that laboratory procedures to obtain high quality graphene are rather cheap and simple. However, any new material market is essentially driven by the progress in its large scale commercial production with minimal costs, with properties that are suited for different applications. And it is in this aspect that graphene is still required to make a huge progress before its commercial benefits can be derived. Laboratory graphene synthesis techniques such as mechanical exfoliation, liquid phase exfoliation and SiC graphene growth pose several challenges in terms of cost, reliability and scalability. To this end, Chemical Vapor Deposition (CVD) growth of graphene has emerged as a widely used synthesis method that overcomes these problems. Unfortunately, conventional thermal CVD requires a high temperature of growth and a catalytic metal substrate, making the undesirable step of graphene transfer a necessity. Besides requiring a catalyst, the high temperature of growth also limits the range of growth substrates. In this work, I have successfully demonstrated low temperature ( 550 °C) growth of graphene directly on dielectric materials using a Plasma-Enhanced CVD (PECVD) process. The PECVD technique described here solves the issues faced by conventional CVD methods and provides a direct route for graphene synthesis on arbitrary materials at relatively low temperatures. Detailed growth studies, as described here, illustrate the difference between the PECVD and the CVD growth mechanisms. This work also provides the first experimental comparison of graphene growth rates on different substrates using PECVD. In the second part of my thesis, I have discussed some of the potential applications of PECVD graphene, including graphene as a diffusion barrier, ultra-dark graphene metamaterials, graphene-protected metal plasmonics and copper-graphene hybrids for RF transmission line applications. The experimental findings discussed here lay a solid platform for integration of graphene in damascene structures, low-loss plasmonic materials, flexible electronics and dark materials, among others.

An evaluation of automatic coronary artery calcium scoring methods with cardiac CT using the orCaScore framework.

PubMed

Wolterink, Jelmer M; Leiner, Tim; de Vos, Bob D; Coatrieux, Jean-Louis; Kelm, B Michael; Kondo, Satoshi; Salgado, Rodrigo A; Shahzad, Rahil; Shu, Huazhong; Snoeren, Miranda; Takx, Richard A P; van Vliet, Lucas J; van Walsum, Theo; Willems, Tineke P; Yang, Guanyu; Zheng, Yefeng; Viergever, Max A; Išgum, Ivana

2016-05-01

The amount of coronary artery calcification (CAC) is a strong and independent predictor of cardiovascular disease (CVD) events. In clinical practice, CAC is manually identified and automatically quantified in cardiac CT using commercially available software. This is a tedious and time-consuming process in large-scale studies. Therefore, a number of automatic methods that require no interaction and semiautomatic methods that require very limited interaction for the identification of CAC in cardiac CT have been proposed. Thus far, a comparison of their performance has been lacking. The objective of this study was to perform an independent evaluation of (semi)automatic methods for CAC scoring in cardiac CT using a publicly available standardized framework. Cardiac CT exams of 72 patients distributed over four CVD risk categories were provided for (semi)automatic CAC scoring. Each exam consisted of a noncontrast-enhanced calcium scoring CT (CSCT) and a corresponding coronary CT angiography (CCTA) scan. The exams were acquired in four different hospitals using state-of-the-art equipment from four major CT scanner vendors. The data were divided into 32 training exams and 40 test exams. A reference standard for CAC in CSCT was defined by consensus of two experts following a clinical protocol. The framework organizers evaluated the performance of (semi)automatic methods on test CSCT scans, per lesion, artery, and patient. Five (semi)automatic methods were evaluated. Four methods used both CSCT and CCTA to identify CAC, and one method used only CSCT. The evaluated methods correctly detected between 52% and 94% of CAC lesions with positive predictive values between 65% and 96%. Lesions in distal coronary arteries were most commonly missed and aortic calcifications close to the coronary ostia were the most common false positive errors. The majority (between 88% and 98%) of correctly identified CAC lesions were assigned to the correct artery. Linearly weighted Cohen's kappa for patient CVD risk categorization by the evaluated methods ranged from 0.80 to 1.00. A publicly available standardized framework for the evaluation of (semi)automatic methods for CAC identification in cardiac CT is described. An evaluation of five (semi)automatic methods within this framework shows that automatic per patient CVD risk categorization is feasible. CAC lesions at ambiguous locations such as the coronary ostia remain challenging, but their detection had limited impact on CVD risk determination.

Advances in the Development of a WCl6 CVD System for Coating UO2 Powders with Tungsten

NASA Technical Reports Server (NTRS)

Mireles, Omar R.; Tieman, Alyssa; Broadway, Jeramie; Hickman, Robert

2013-01-01

W-UO2 CERMET fuels are under development to enable Nuclear Thermal Propulsion (NTP) for deep space exploration. Research efforts with an emphasis on fuel fabrication, testing, and identification of potential risks is underway. One primary risk is fuel loss due to CTE mismatch between W and UO2 and the grain boundary structure of W particles resulting in higher thermal stresses. Mechanical failure can result in significant reduction of the UO2 by hot hydrogen. Fuel loss can be mitigated if the UO2 particles are coated with a layer of high density tungsten before the consolidation process. This paper discusses the work to date, results, and advances of a fluidized bed chemical vapor deposition (CVD) system that utilizes the H2-WCl6 reduction process. Keywords: Space, Nuclear, Thermal, Propulsion, Fuel, CERMET, CVD, Tungsten, Uranium

iCVD Cyclic Polysiloxane and Polysilazane as Nanoscale Thin-Film Electrolyte: Synthesis and Properties.

PubMed

Chen, Nan; Reeja-Jayan, B; Liu, Andong; Lau, Jonathan; Dunn, Bruce; Gleason, Karen K

2016-03-01

A group of crosslinked cyclic siloxane (Si-O) and silazane (Si-N) polymers are synthesized via solvent-free initiated chemical vapor deposition (iCVD). Notably, this is the first report of cyclic polysilazanes synthesized via the gas-phase iCVD method. The deposited nanoscale thin films are thermally stable and chemically inert. By iCVD, they can uniformly and conformally cover nonplanar surfaces having complex geometry. Although polysiloxanes are traditionally utilized as dielectric materials and insulators, our research shows these cyclic organosilicon polymers can conduct lithium ions (Li(+) ) at room temperature. The conformal coating and the room temperature ionic conductivity make these cyclic organosilicon polymers attractive for use as thin-film electrolytes in solid-state batteries. Also, their synthesis process and properties have been systemically studied and discussed. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Rhenium material properties

NASA Technical Reports Server (NTRS)

Biaglow, James A.

1995-01-01

Tensile data were obtained from four different types of rhenium at ambient and elevated temperatures. The four types of rhenium included chemical vapor deposition (CVD) and three powder metallurgy (PM) types, i.e., rolled sheet and pressed and sintered bars, with and without hot isostatic pressure (HIP) treatment. Results revealed a wide range of values with ultimate strengths at ambient temperatures varying from 663 MPa for CVD rhenium to 943 MPa for rolled sheet. A similar spread was also obtained for material tested at 1088 K and 1644 K. The wide variance observed with the different materials indicated that the rhenium manufacturing process, material composition and prior handling strongly dictated its properties. In addition to tensile properties, CVD, pressed and sintered material and HIP rhenium successfully completed 100 cycles of low cycle fatigue. Creep data were also obtained showing that CVD and pressed and sintered rhenium could sustain five hours of testing under a tension of 27.5 MPa at 1922 K.

Chemical reactivity of CVC and CVD SiC with UO2 at high temperatures

NASA Astrophysics Data System (ADS)

Silva, Chinthaka M.; Katoh, Yutai; Voit, Stewart L.; Snead, Lance L.

2015-05-01

Two types of silicon carbide (SiC) synthesized using two different vapor deposition processes were embedded in UO2 pellets and evaluated for their potential chemical reaction with UO2. While minor reactivity between chemical-vapor-composited (CVC) SiC and UO2 was observed at comparatively low temperatures of 1100 and 1300 °C, chemical-vapor-deposited (CVD) SiC did not show any such reactivity. However, both CVD and CVC SiCs showed some reaction with UO2 at a higher temperature (1500 °C). Elemental maps supported by phase maps obtained using electron backscatter diffraction indicated that CVC SiC was more reactive than CVD SiC at 1500 °C. Furthermore, this investigation indicated the formation of uranium carbides and uranium silicide chemical phases such as UC, USi2, and U3Si2 as a result of SiC reaction with UO2.

Gaalas/Gaas Solar Cell Process Study

NASA Technical Reports Server (NTRS)

Almgren, D. W.; Csigi, K. I.

1980-01-01

Available information on liquid phase, vapor phase (including chemical vapor deposition) and molecular beam epitaxy growth procedures that could be used to fabricate single crystal, heteroface, (AlGa) As/GaAs solar cells, for space applications is summarized. A comparison of the basic cost elements of the epitaxy growth processes shows that the current infinite melt LPE process has the lower cost per cell for an annual production rate of 10,000 cells. The metal organic chemical vapor deposition (MO-CVD) process has the potential for low cost production of solar cells but there is currently a significant uncertainty in process yield, i.e., the fraction of active material in the input gas stream that ends up in the cell. Additional work is needed to optimize and document the process parameters for the MO-CVD process.

Kinetics of low pressure CVD growth of SiO2 on InP and Si

NASA Technical Reports Server (NTRS)

Iyer, R.; Lile, D. L.

1988-01-01

The kinetics of low pressure CVD growth of SiO2 from SiH4 and O2 has been investigated for the case of an indirect (remote) plasma process. Homogeneous (gas phase) and heterogeneous operating ranges have been experimentally identified. The process was shown to be consistent within the heterogeneous surface-reaction dominated range of operation. A kinetic rate equation is given for growth at 14 W RF power input and 400 mtorr total pressure on both InP and Si substrates. The process exhibits an activation energy of 8.4 + or - 0.6 kcal/mol.

EULAR recommendations for cardiovascular disease risk management in patients with rheumatoid arthritis and other forms of inflammatory joint disorders: 2015/2016 update.

PubMed

Agca, R; Heslinga, S C; Rollefstad, S; Heslinga, M; McInnes, I B; Peters, M J L; Kvien, T K; Dougados, M; Radner, H; Atzeni, F; Primdahl, J; Södergren, A; Wallberg Jonsson, S; van Rompay, J; Zabalan, C; Pedersen, T R; Jacobsson, L; de Vlam, K; Gonzalez-Gay, M A; Semb, A G; Kitas, G D; Smulders, Y M; Szekanecz, Z; Sattar, N; Symmons, D P M; Nurmohamed, M T

2017-01-01

Patients with rheumatoid arthritis (RA) and other inflammatory joint disorders (IJD) have increased cardiovascular disease (CVD) risk compared with the general population. In 2009, the European League Against Rheumatism (EULAR) taskforce recommended screening, identification of CVD risk factors and CVD risk management largely based on expert opinion. In view of substantial new evidence, an update was conducted with the aim of producing CVD risk management recommendations for patients with IJD that now incorporates an increasing evidence base. A multidisciplinary steering committee (representing 13 European countries) comprised 26 members including patient representatives, rheumatologists, cardiologists, internists, epidemiologists, a health professional and fellows. Systematic literature searches were performed and evidence was categorised according to standard guidelines. The evidence was discussed and summarised by the experts in the course of a consensus finding and voting process. Three overarching principles were defined. First, there is a higher risk for CVD in patients with RA, and this may also apply to ankylosing spondylitis and psoriatic arthritis. Second, the rheumatologist is responsible for CVD risk management in patients with IJD. Third, the use of non-steroidal anti-inflammatory drugs and corticosteroids should be in accordance with treatment-specific recommendations from EULAR and Assessment of Spondyloarthritis International Society. Ten recommendations were defined, of which one is new and six were changed compared with the 2009 recommendations. Each designated an appropriate evidence support level. The present update extends on the evidence that CVD risk in the whole spectrum of IJD is increased. This underscores the need for CVD risk management in these patients. These recommendations are defined to provide assistance in CVD risk management in IJD, based on expert opinion and scientific evidence. 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/.

Gene expression profile in cardiovascular disease and preeclampsia: a meta-analysis of the transcriptome based on raw data from human studies deposited in Gene Expression Omnibus.

PubMed

Sitras, V; Fenton, C; Acharya, G

2015-02-01

Cardiovascular disease (CVD) and preeclampsia (PE) share common clinical features. We aimed to identify common transcriptomic signatures involved in CVD and PE in humans. Meta-analysis of individual raw microarray data deposited in GEO, obtained from blood samples of patients with CVD versus controls and placental samples from women with PE versus healthy women with uncomplicated pregnancies. Annotation of cases versus control samples was taken directly from the microarray documentation. Genes that showed a significant differential expression in the majority of experiments were selected for subsequent analysis. Hypergeometric gene list analysis was performed using Bioconductor GOstats package. Bioinformatic analysis was performed in PANTHER. Seven studies in CVD and 5 studies in PE were eligible for meta-analysis. A total of 181 genes were found to be differentially expressed in microarray studies investigating gene expression in blood samples obtained from patients with CVD compared to controls and 925 genes were differentially expressed between preeclamptic and healthy placentas. Among these differentially expressed genes, 22 were common between CVD and PE. Bioinformatic analysis of these genes revealed oxidative stress, p-53 pathway feedback, inflammation mediated by chemokines and cytokines, interleukin signaling, B-cell activation, PDGF signaling, Wnt signaling, integrin signaling and Alzheimer disease pathways to be involved in the pathophysiology of both CVD and PE. Metabolism, development, response to stimulus, immune response and cell communication were the associated biologic processes in both conditions. Gene set enrichment analysis showed the following overlapping pathways between CVD and PE: TGF-β-signaling, apoptosis, graft-versus-host disease, allograft rejection, chemokine signaling, steroid hormone synthesis, type I and II diabetes mellitus, VEGF signaling, pathways in cancer, GNRH signaling, Huntingtons disease and Notch signaling. CVD and PE share same common traits in their gene expression profile indicating common pathways in their pathophysiology. Copyright © 2014 Elsevier Ltd. All rights reserved.

Is the relationship between cigarette smoking and male erectile dysfunction independent of cardiovascular disease? Findings from a population-based cross-sectional study.

PubMed

Chew, Kew-Kim; Bremner, Alexandra; Stuckey, Bronwyn; Earle, Carolyn; Jamrozik, Konrad

2009-01-01

Cigarette smoking has been implicated in the pathophysiology of cardiovascular disease (CVD) and as a risk factor for erectile dysfunction (ED). However, various aspects of the associations between cigarette smoking, ED, and CVD need further elucidation. We explored the relationship between cigarette smoking, ED, and CVD using data from a population-based cross-sectional study of 1,580 participants. Postal questionnaires were sent to randomly selected age-stratified male population samples obtained from the Western Australia Electoral Roll. In addition to items covering sociodemographic and self-reported clinical information and smoking habits, the 5-item International Index of Erectile Function was used to assess erectile function. Compared with never smokers, the odds of ED, adjusted for age, square of age, and CVD, were significantly higher among current smokers (odds ratio [OR] = 1.40; 95% confidence interval [CI] 1.02, 1.92) and ever smokers (OR = 1.57; 95% CI 1.02, 2.42). Similarly, the adjusted odds of severe ED were significantly higher among former smokers. Albeit not statistically significant, the age-adjusted odds of ED among current smokers increased with the number of cigarettes smoked. Among former smokers, the age-adjusted odds of ED were significantly higher 6-10 years following cessation of smoking than < or = 5 or > 10 years. Compared with never smokers without CVD, the age-adjusted odds of ED among former smokers and ever smokers without CVD were about 1.6. Regardless of smoking, these odds were significantly higher among participants with CVD. Compared with never smokers, former smokers and ever smokers have significantly higher odds of ED. The relationship between smoking and ED is independent of that between smoking and CVD, and not because of confounding by CVD. Patterns of ED in former smokers suggest that there may be a latent interval between active smoking and symptomatic ED, involving a process initially triggered by smoking.

Chinese Cardiovascular Disease Mobile Apps’ Information Types, Information Quality, and Interactive Functions for Self-Management: Systematic Review

PubMed Central

Xie, Bo; Su, Zhaohui; Zhang, Wenhui

2017-01-01

Background China has a large population with cardiovascular disease (CVD) that requires extensive self-management. Mobile health (mHealth) apps may be a useful tool for CVD self-management. Little is currently known about the types and quality of health information provided in Chinese CVD mobile apps and whether app functions are conducive to promoting CVD self-management. Objective We undertook a systematic review to evaluate the types and quality of health information provided in Chinese CVD mobile apps and interactive app functions for promoting CVD self-management. Methods Mobile apps targeting end users in China with CVD conditions were selected in February 2017 through a multi-stage process. Three frameworks were used to evaluate the selected apps: (1) types of health information offered were assessed using our Health Information Wants framework, which encompasses 7 types of information; (2) quality of information provided in the apps was assessed using the 11 guidelines recommended by the National Library of Medicine of the National Institutes of Health; and (3) types of interactive app functions for CVD self-management were assessed using a 15-item framework adapted from the literature, including our own prior work. Results Of 578 apps identified, 82 were eligible for final review. Among these, information about self-care (67/82, 82%) and information specifically regarding CVD (63/82, 77%) were the most common types of information provided, while information about health care providers (22/82, 27%) and laboratory tests (5/82, 6%) were least common. The most common indicators of information quality were the revealing of apps’ providers (82/82, 100%) and purpose (82/82, 100%), while the least common quality indicators were the revealing of how apps’ information was selected (1/82, 1%) and app sponsorship (0/82, 0%). The most common interactive functions for CVD self-management were those that enabled user interaction with the app provider (57/82, 70%) and with health care providers (36/82, 44%), while the least common interactive functions were those that enabled lifestyle management (13/82, 16%) and psychological health management (6/82, 7%). None of the apps covered all 7 types of health information, all 11 indicators of information quality, or all 15 interactive functions for CVD self-management. Conclusions Chinese CVD apps are insufficient in providing comprehensive health information, high-quality information, and interactive functions to facilitate CVD self-management. End users should exercise caution when using existing apps. Health care professionals and app developers should collaborate to better understand end users’ preferences and follow evidence-based guidelines to develop mHealth apps conducive to CVD self-management. PMID:29242176

Chinese Cardiovascular Disease Mobile Apps' Information Types, Information Quality, and Interactive Functions for Self-Management: Systematic Review.

PubMed

Xie, Bo; Su, Zhaohui; Zhang, Wenhui; Cai, Run

2017-12-14

China has a large population with cardiovascular disease (CVD) that requires extensive self-management. Mobile health (mHealth) apps may be a useful tool for CVD self-management. Little is currently known about the types and quality of health information provided in Chinese CVD mobile apps and whether app functions are conducive to promoting CVD self-management. We undertook a systematic review to evaluate the types and quality of health information provided in Chinese CVD mobile apps and interactive app functions for promoting CVD self-management. Mobile apps targeting end users in China with CVD conditions were selected in February 2017 through a multi-stage process. Three frameworks were used to evaluate the selected apps: (1) types of health information offered were assessed using our Health Information Wants framework, which encompasses 7 types of information; (2) quality of information provided in the apps was assessed using the 11 guidelines recommended by the National Library of Medicine of the National Institutes of Health; and (3) types of interactive app functions for CVD self-management were assessed using a 15-item framework adapted from the literature, including our own prior work. Of 578 apps identified, 82 were eligible for final review. Among these, information about self-care (67/82, 82%) and information specifically regarding CVD (63/82, 77%) were the most common types of information provided, while information about health care providers (22/82, 27%) and laboratory tests (5/82, 6%) were least common. The most common indicators of information quality were the revealing of apps' providers (82/82, 100%) and purpose (82/82, 100%), while the least common quality indicators were the revealing of how apps' information was selected (1/82, 1%) and app sponsorship (0/82, 0%). The most common interactive functions for CVD self-management were those that enabled user interaction with the app provider (57/82, 70%) and with health care providers (36/82, 44%), while the least common interactive functions were those that enabled lifestyle management (13/82, 16%) and psychological health management (6/82, 7%). None of the apps covered all 7 types of health information, all 11 indicators of information quality, or all 15 interactive functions for CVD self-management. Chinese CVD apps are insufficient in providing comprehensive health information, high-quality information, and interactive functions to facilitate CVD self-management. End users should exercise caution when using existing apps. Health care professionals and app developers should collaborate to better understand end users' preferences and follow evidence-based guidelines to develop mHealth apps conducive to CVD self-management. ©Bo Xie, Zhaohui Su, Wenhui Zhang, Run Cai. Originally published in JMIR Mhealth and Uhealth (http://mhealth.jmir.org), 14.12.2017.

Cardiovascular disease medication health literacy among Indigenous peoples: design and protocol of an intervention trial in Indigenous primary care services.

PubMed

Crengle, Sue; Smylie, Janet; Kelaher, Margaret; Lambert, Michelle; Reid, Susan; Luke, Joanne; Anderson, Ian; Harré Hindmarsh, Jennie; Harwood, Matire

2014-07-12

Cardiovascular diseases (CVD) are leading causes of mortality and morbidity among Indigenous people in New Zealand, Australia and Canada and are a major driver of the inequities in life expectancy between Indigenous and non-Indigenous people in these countries. Evidence-based pharmaceutical management of CVD can significantly reduce mortality and morbidity for persons diagnosed with CVD or for those at intermediate or high risk of CVD. Health literacy has been identified as a major barrier in the communication and implementation of appropriate pharmaceutical management plans for CVD. Addressing health literacy is particularly relevant in Indigenous populations where there are unique health and adult literacy challenges. This study will examine the effect of a customized, structured CVD medication programme, delivered by health professionals, on the health literacy of Indigenous people with, or at risk, of CVD. Primary outcomes are patient's knowledge about CVD medications; secondary outcomes examine changes in health literacy skills and practices. The study will employ a multi-site pre-post design with multiple measurement points to assess intervention efficacy. Participants will be recruited from four Indigenous primary care services in Australia, Canada and New Zealand. Three educational sessions will be delivered over four weeks. A tablet application will support the education sessions and produce a customized pill card for each participant. Participants will be provided with written information about CVD medications. Medication knowledge scores, and specific health literacy skills and practices will be assessed before and after the three sessions. Statistical analyses will identify significant changes in outcomes over each session, and from the pre-session one to post-session three time points. This study will make an important contribution to understanding the effect of a structured primary care-based intervention on CVD health literacy in Indigenous populations. The study also illustrates the incorporation of Indigenous health research principles and processes in clinical trials and provides insights that may be useful in other contexts. Australian and New Zealand Clinical Trials Register (ACTRN12612001309875; date of registration 18/12/2012).

Measuring Physical Activity in Outdoor Community Recreational Environments: Implications for Research, Policy, and Practice

PubMed Central

Jones, Sydney A.; Stransky, Michelle; Evenson, Kelly R.

2015-01-01

Chronic diseases such as cardiovascular disease (CVD) are major contributors to escalating health care costs in the USA. Physical activity is an important protective factor against CVD, and the National Prevention Strategy recognizes active living (defined as a way of life that integrates physical activity into everyday routines) as a priority for improving the nation’s health. This paper focuses on developing more inclusive measures of physical activity in outdoor community recreational environments, specifically parks and trails, to enhance their usability for at-risk populations such as persons with mobility limitations. We develop an integrated conceptual framework for measuring physical activity in outdoor community recreational environments, describe examples of evidence-based tools for measuring physical activity in these settings, and discuss strategies to improve measurement of physical activity for persons with mobility limitations. Addressing these measurement issues is critically important to making progress towards national CVD goals pertaining to active community environments. PMID:26005510

Garlic-Derived Organic Polysulfides and Myocardial Protection123

PubMed Central

Bradley, Jessica M; Organ, Chelsea L; Lefer, David J

2016-01-01

For centuries, garlic has been shown to exert substantial medicinal effects and is considered to be one of the best disease-preventative foods. Diet is important in the maintenance of health and prevention of many diseases including cardiovascular disease (CVD). Preclinical and clinical evidence has shown that garlic reduces risks associated with CVD by lowering cholesterol, inhibiting platelet aggregation, and lowering blood pressure. In recent years, emerging evidence has shown that hydrogen sulfide (H2S) has cardioprotective and cytoprotective properties. The active metabolite in garlic, allicin, is readily degraded into organic diallyl polysulfides that are potent H2S donors in the presence of thiols. Preclinical studies have shown that enhancement of endogenous H2S has an impact on vascular reactivity. In CVD models, the administration of H2S prevents myocardial injury and dysfunction. It is hypothesized that these beneficial effects of garlic may be mediated by H2S-dependent mechanisms. This review evaluates the current knowledge concerning the cardioprotective effects of garlic-derived diallyl polysulfides. PMID:26764335

Interface properties of SiO2/GaN structures formed by chemical vapor deposition with remote oxygen plasma mixed with Ar or He

NASA Astrophysics Data System (ADS)

Truyen, Nguyen Xuan; Taoka, Noriyuki; Ohta, Akio; Makihara, Katsunori; Yamada, Hisashi; Takahashi, Tokio; Ikeda, Mitsuhisa; Shimizu, Mitsuaki; Miyazaki, Seiichi

2018-06-01

The impacts of noble gas species (Ar and He) on the formation of a SiO2/GaN structure formed by a remote oxygen plasma-enhanced chemical vapor deposition (ROPE-CVD) method were systematically investigated. Atomic force microscopy revealed that ROPE-CVD with He leads to a smooth SiO2 surface compared with the case of Ar. We found that no obvious oxidations of the GaN surfaces after the SiO2 depositions with the both Ar and He cases were observed. The capacitance–voltage (C–V) curves of the GaN MOS capacitors formed by ROPE-CVD with the Ar and He dilutions show good interface properties with no hysteresis and good agreement with the ideal C–V curves even after post deposition annealing at 800 °C. Besides, we found that the current density–oxide electric field characteristics shows a gate leakage current for the Ar case lower than the He case.

Radio frequency and microwave plasma for optical thin-film deposition

NASA Astrophysics Data System (ADS)

Otto, Juergen; Paquet, Volker; Kersten, Ralf T.; Etzkorn, Heinz-Werner; Brusasco, Raymond M.; Britten, Jerald A.; Campbell, Jack H.; Thorsness, J. B.

1990-12-01

For the next generation of fusion lasers reflecting mirrors with laser damage thresholds of at least 40 J/cm2 for 1 0 ns laser pulses at 1 .064 pm are needed. Up to now, no deposition technique has been developed to produce such mirrors. Best R&D-values realized today are around 30 J/cm2 for e-beam evaporated mirrors. R&D on conventional e-beam coating processes over the last 1 0 years has come up with marginal improvements in laser damage thresholds only. However, new technologies, like PICVD (Plasma-Impulse CVD) developed for the fabrication of ultra-low loss fiber preforms, seem to offer the potential to solve this problem. First results have been reported already [1-3]. It is well known that fused silica produced by CVD processes can have laser damage thresholds as high as 80 J/cm2. However, the thickness of a single deposited film is in the pm-range for most of the CVD-processes used for preform manufacturing; since interference optics need films in the ; /4n range (where n is the refractive index of the dielectric material) the use of preform-fabrication processes for the purpose of interference mirror fabrication is limited to a few plasma based CVD technologies, namely PCVD (Plasma-CVD, Philips [4]; PICVD, SCHOTT [5]). Especially PICVD is a very powerful technology to fabricate thin film multilayers for interference mirrors, because this technique is able to produce films down to monolayer thickness with nearly perfect stoichiometry and morphology. In first and preliminary experiments the usual deposition in a circular tube at high temperatures has been used for simplicity. However, to produce large area high quality laser mirrors this principle know-how has to be transfered from circular to planar geometry. Experiments showed, that there may be some limitations with respect to the homogeneity of a planar deposition using microwave excitation for the plasma. Therefore experiments have been performed in parallel with both RF and microwave excitation for comparison. In the following we will restrict ourselves to the description and discussions of the planar processes; the principle and details of the PICVD-process are described elsewhere [5] while RF-plasma technology is a well known process.

Dietary fat intake and risk of cardiovascular disease and all-cause mortality in a population at high risk of cardiovascular disease.

PubMed

Guasch-Ferré, Marta; Babio, Nancy; Martínez-González, Miguel A; Corella, Dolores; Ros, Emilio; Martín-Peláez, Sandra; Estruch, Ramon; Arós, Fernando; Gómez-Gracia, Enrique; Fiol, Miquel; Santos-Lozano, José M; Serra-Majem, Lluís; Bulló, Mònica; Toledo, Estefanía; Barragán, Rocío; Fitó, Montserrat; Gea, Alfredo; Salas-Salvadó, Jordi

2015-12-01

Dietary fat quality and fat replacement are more important for cardiovascular disease (CVD) prevention than is total dietary fat intake. The aim was to evaluate the association between total fat intake and fat subtypes with the risk of CVD (myocardial infarction, stroke, or death from cardiovascular causes) and cardiovascular and all-cause death. We also examined the hypothetical effect of the isocaloric substitution of one macronutrient for another. We prospectively studied 7038 participants at high CVD risk from the PREvención con DIeta MEDiterránea (PREDIMED) study. The trial was conducted from 2003 to 2010, but the present analysis was based on an expanded follow-up until 2012. At baseline and yearly thereafter, total and specific fat subtypes were repeatedly measured by using validated food-frequency questionnaires. Time-dependent Cox proportional hazards models were used. After 6 y of follow-up, we documented 336 CVD cases and 414 total deaths. HRs (95% CIs) for CVD for those in the highest quintile of total fat, monounsaturated fatty acid (MUFA), and polyunsaturated fatty acid (PUFA) intake compared with those in the lowest quintile were 0.58 (0.39, 0.86), 0.50 (0.31, 0.81), and 0.68 (0.48, 0.96), respectively. In the comparison between extreme quintiles, higher saturated fatty acid (SFA) and trans-fat intakes were associated with 81% (HR: 1.81; 95% CI: 1.05, 3.13) and 67% (HR: 1.67; 95% CI: 1.09, 2.57) higher risk of CVD. Inverse associations with all-cause death were also observed for PUFA and MUFA intakes. Isocaloric replacements of SFAs with MUFAs and PUFAs or trans fat with MUFAs were associated with a lower risk of CVD. SFAs from pastries and processed foods were associated with a higher risk of CVD. Intakes of MUFAs and PUFAs were associated with a lower risk of CVD and death, whereas SFA and trans-fat intakes were associated with a higher risk of CVD. The replacement of SFAs with MUFAs and PUFAs or of trans fat with MUFAs was inversely associated with CVD. This trial was registered at www.controlled-trials.com as ISRCTN 35739639. © 2015 American Society for Nutrition.

Potential Approaches to Enhance the Effects of Estrogen on Senescent Blood Vessels and Postmenopausal Cardiovascular Disease

PubMed Central

Khalil, Raouf A.

2010-01-01

Cardiovascular disease (CVD) is more common in postmenopausal than premenopausal women, suggesting vascular protective effects of estrogen. Vascular estrogen receptors ERα, ERβ and a transmembrane estrogen-binding protein GPR30 have been described. Also, experimental studies have demonstrated vasodilator effects of estrogen on the endothelium, vascular smooth muscle and extracellular matrix. However, randomized clinical trials have not supported vascular benefits of menopausal hormone therapy (MHT), possibly due to the subjects' advanced age and age-related changes in estrogen synthesis and metabolic pathways, the vascular ERs number, distribution and integrity, and the post-ER vascular signaling pathways. Current MHT includes natural estrogens such as conjugated equine estrogen, as well as synthetic and semi-synthetic estrogens. New estrogenic formulations and hormone combinations have been developed. Phytoestrogens is being promoted as an alternative MHT. Specific ER modulators (SERMs), and selective agonists for ERα such as PPT, ERβ such as DPN, and GPR30 such as G1 are being evaluated. In order to enhance the vascular effectiveness of MHT, its type, dose, route of administration and timing may need to be customized depending on the subject's age and pre-existing CVD. Also, the potential interaction of estrogen with progesterone and testosterone on vascular function may need to be considered in order to maximize the vascular benefits of MHT on senescent blood vessels and postmenopausal CVD. PMID:20210774

Diffusion mechanisms in chemical vapor-deposited iridium coated on chemical vapor-deposited rhenium

NASA Technical Reports Server (NTRS)

Hamilton, J. C.; Yang, N. Y. C.; Clift, W. M.; Boehme, D. R.; Mccarty, K. F.; Franklin, J. E.

1992-01-01

Radiation-cooled rocket thruster chambers have been developed which use CVD Re coated with CVD Ir on the interior surface that is exposed to hot combustion gases. The Ir serves as an oxidation barrier which protects the structural integrity-maintaining Re at elevated temperatures. The diffusion kinetics of CVD materials at elevated temperatures is presently studied with a view to the prediction and extension of these thrusters' performance limits. Line scans for Ir and Re were fit on the basis of a diffusion model, in order to extract relevant diffusion constants; the fastest diffusion process is grain-boundary diffusion, where Re diffuses down grain boundaries in the Ir overlayer.

Synthesis of high performance ceramic fibers by chemical vapor deposition for advanced metallics reinforcing

NASA Technical Reports Server (NTRS)

Revankar, Vithal; Hlavacek, Vladimir

1991-01-01

The chemical vapor deposition (CVD) synthesis of fibers capable of effectively reinforcing intermetallic matrices at elevated temperatures which can be used for potential applications in high temperature composite materials is described. This process was used due to its advantage over other fiber synthesis processes. It is extremely important to produce these fibers with good reproducible and controlled growth rates. However, the complex interplay of mass and energy transfer, blended with the fluid dynamics makes this a formidable task. The design and development of CVD reactor assembly and system to synthesize TiB2, CrB, B4C, and TiC fibers was performed. Residual thermal analysis for estimating stresses arising form thermal expansion mismatch were determined. Various techniques to improve the mechanical properties were also performed. Various techniques for improving the fiber properties were elaborated. The crystal structure and its orientation for TiB2 fiber is discussed. An overall view of the CVD process to develop CrB2, TiB2, and other high performance ceramic fibers is presented.

Shared molecular pathways and gene networks for cardiovascular disease and type 2 diabetes mellitus in women across diverse ethnicities.

PubMed

Chan, Kei Hang K; Huang, Yen-Tsung; Meng, Qingying; Wu, Chunyuan; Reiner, Alexander; Sobel, Eric M; Tinker, Lesley; Lusis, Aldons J; Yang, Xia; Liu, Simin

2014-12-01

Although cardiovascular disease (CVD) and type 2 diabetes mellitus (T2D) share many common risk factors, potential molecular mechanisms that may also be shared for these 2 disorders remain unknown. Using an integrative pathway and network analysis, we performed genome-wide association studies in 8155 blacks, 3494 Hispanic American, and 3697 Caucasian American women who participated in the national Women's Health Initiative single-nucleotide polymorphism (SNP) Health Association Resource and the Genomics and Randomized Trials Network. Eight top pathways and gene networks related to cardiomyopathy, calcium signaling, axon guidance, cell adhesion, and extracellular matrix seemed to be commonly shared between CVD and T2D across all 3 ethnic groups. We also identified ethnicity-specific pathways, such as cell cycle (specific for Hispanic American and Caucasian American) and tight junction (CVD and combined CVD and T2D in Hispanic American). In network analysis of gene-gene or protein-protein interactions, we identified key drivers that included COL1A1, COL3A1, and ELN in the shared pathways for both CVD and T2D. These key driver genes were cross-validated in multiple mouse models of diabetes mellitus and atherosclerosis. Our integrative analysis of American women of 3 ethnicities identified multiple shared biological pathways and key regulatory genes for the development of CVD and T2D. These prospective findings also support the notion that ethnicity-specific susceptibility genes and process are involved in the pathogenesis of CVD and T2D. © 2014 American Heart Association, Inc.

Concentration variance decay during magma mixing: a volcanic chronometer.

PubMed

Perugini, Diego; De Campos, Cristina P; Petrelli, Maurizio; Dingwell, Donald B

2015-09-21

The mixing of magmas is a common phenomenon in explosive eruptions. Concentration variance is a useful metric of this process and its decay (CVD) with time is an inevitable consequence during the progress of magma mixing. In order to calibrate this petrological/volcanological clock we have performed a time-series of high temperature experiments of magma mixing. The results of these experiments demonstrate that compositional variance decays exponentially with time. With this calibration the CVD rate (CVD-R) becomes a new geochronometer for the time lapse from initiation of mixing to eruption. The resultant novel technique is fully independent of the typically unknown advective history of mixing - a notorious uncertainty which plagues the application of many diffusional analyses of magmatic history. Using the calibrated CVD-R technique we have obtained mingling-to-eruption times for three explosive volcanic eruptions from Campi Flegrei (Italy) in the range of tens of minutes. These in turn imply ascent velocities of 5-8 meters per second. We anticipate the routine application of the CVD-R geochronometer to the eruptive products of active volcanoes in future in order to constrain typical "mixing to eruption" time lapses such that monitoring activities can be targeted at relevant timescales and signals during volcanic unrest.

Improving diabetes care: Multi-component CArdiovascular Disease Risk Reduction Strategies for People with Diabetes in South Asia - The CARRS Multi-center Translation Trial

PubMed Central

Shah, Seema; Singh, Kavita; Ali, Mohammed K.; Mohan, V.; Kadir, Muhammad Masood; Unnikrishnan, A.G.; Sahay, Rakesh Kumar; Varthakavi, Premlata; Dharmalingam, Mala; Viswanathan, Vijay; Masood, Qamar; Bantwal, Ganapathi; Khadgawat, Rajesh; Desai, Ankush; Sethi, Bipin Kumar; Shivashankar, Roopa; Ajay, Vamadevan S; Reddy, K. Srinath; Narayan, K.M. Venkat; Prabhakaran, Dorairaj; Tandon, Nikhil

2012-01-01

Aims Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in people with diabetes in South Asia. The CARRS translation trial tests the effectiveness, cost-effectiveness, and sustainability of a clinic-based multi-component CVD risk reduction intervention among people with diabetes in India and Pakistan. Methods We randomly assigned 1,146 adults with diabetes recruited from 10 urban clinic sites, to receive usual care by physicians or to receive an integrated multi-component CVD risk reduction intervention. The intervention involves electronic health record management, decision-support prompts to the healthcare team, and the support of a care coordinator to actively facilitate patient and provider adherence to evidence-based guidelines. The primary outcome is a composite of multiple CVD risk factor control (blood glucose and either blood pressure or cholesterol, or all three). Other outcomes include control of the individual CVD risk factors, process and patient-centered measures, cost-effectiveness, and acceptability/feasibility. Conclusion The CARRS translation trial tests a low-cost diabetes care delivery model in urban South Asia to achieve comprehensive cardio-metabolic disease case-management of high-risk patients (clinicaltrials.gov number: NCT01212328). PMID:23084280

Optical materials characterization final technical report february 1, 1978-september 30, 1978. Technical note

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feldman, A.; Horowitz, D.; Waxter, R.M.

1979-02-01

Data obtained as part of the Optical Materials Characterization Program are summarized in this report. Room temperature values of refractive index as a function of wavelength are presented for the following materials: commercially grown KCl, reactive atmosphere processed (RAP) KCl, KCl nominally doped with 1.5% KI, hot forged CaF2, fusion cast CaF2, CaF2 doped with Er (0.001% to 3% Er), SrF2, chemical vapor deposited (CVD) ZnSe (2 specimens), and ZnS (CVD, 2 specimens). Data for the thermo-optic constant (dn/dT) and the linear thermal expansion coefficient are given for the following materials over the temperature range -180 degrees C to 200more » degrees C: Al2O3, BaF2, CaF2, CdF2, KBr, KCl, LiF, MgF2, NaCl, NaF, SrF2, ZnS (CVD), and ZnSe (CVD). The piezo-optic constants of the following materials are presented: As2S3 glass, CaF2, BaF2, Ge, KCl, fused SiO2, SrF2, a chalcogenide glass (Ge 33%, As 12%, Se 55%) and ZnSe (CVD).« less

Deposition and Characterization of Thin Films on Metallic Substrates

NASA Technical Reports Server (NTRS)

Gatica, Jorge E.

2005-01-01

A CVD method was successfully developed to produce conversion coatings on aluminum alloys surfaces with reproducible results with a variety of precursors. A well defined protocol to prepare the precursor solutions formulated in a previous research was extended to other additives. It was demonstrated that solutions prepared following such a protocol could be used to systematically generate protective coatings onto aluminum surfaces. Experiments with a variety of formulations revealed that a refined deposition protocol yields reproducible conversion coatings of controlled composition. A preliminary correlation between solution formulations and successful precursors was derived. Coatings were tested for adhesion properties enhancement for commercial paints. A standard testing method was followed and clear trends were identified. Only one precursors was tested systematically. Anticipated work on other precursors should allow a better characterization of the effect of intermetallics on the production of conversion/protective coatings on metals and ceramics. The significance of this work was the practical demonstration that chemical vapor deposition (CVD) techniques can be used to systematically generate protective/conversion coating on non-ferrous surfaces. In order to become an effective approach to replace chromate-based pre- treatment processes, namely in the aerospace or automobile industry, the process parameters must be defined more precisely. Moreover, the feasibility of scale-up designs necessitates a more comprehensive characterization of the fluid flow, transport phenomena, and chemical kinetics interacting in the process. Kinetic characterization showed a significantly different effect of magnesium-based precursors when compared to iron-based precursors. Future work will concentrate on refining the process through computer simulations and further experimental studies on the effect of other transition metals to induce deposition of conversion/protective films on aluminum and other metallic substrates.

CREATE Wellness: A multi-component behavioral intervention for patients not responding to traditional Cardiovascular disease management.

PubMed

Miller-Rosales, Chris; Sterling, Stacy A; Wood, Sabrina B; Ross, Thekla; Makki, Mojdeh; Zamudio, Cindy; Kane, Irene M; Richardson, Megan C; Samayoa, Claudia; Charvat-Aguilar, Nancy; Lu, Wendy Y; Vo, Michelle; Whelan, Kimberly; Uratsu, Connie S; Grant, Richard W

2017-12-01

Cardiovascular disease (CVD) is the leading cause of death in the US. Many patients do not benefit from traditional disease management approaches to CVD risk reduction. Here we describe the rationale, development, and implementation of a multi-component behavioral intervention targeting patients who have persistently not met goals of CVD risk factor control. Informed by published evidence, relevant theoretical frameworks, stakeholder advice, and patient input, we developed a group-based intervention (Changing Results: Engage and Activate to Enhance Wellness; "CREATE Wellness") to address the complex needs of patients with elevated or unmeasured CVD-related risk factors. We are testing this intervention in a randomized trial among patients with persistent (i.e > 2 years) sub-optimal risk factor control despite being enrolled in an advanced and highly successful CVD disease management program. The CREATE Wellness intervention is designed as a 3 session, group-based intervention combining proven elements of patient activation, health system engagement skills training, shared decision making, care planning, and identification of lifestyle change barriers. Our key learnings in designing the intervention included the value of multi-level stakeholder input and the importance of pragmatic skills training to address barriers to care. The CREATE Wellness intervention represents an evidence-based, patient-centered approach for patients not responding to traditional disease management. The trial is currently underway at three medical facilities within Kaiser Permanente Northern California and next steps include an evaluation of efficacy, adaptation for non-English speaking patient populations, and modification of the curriculum for web- or phone-based versions. NCT02302612.

Structurally controlled deposition of silicon onto nanowires

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Weijie; Liu, Zuqin; Han, Song

Provided herein are nanostructures for lithium ion battery electrodes and methods of fabrication. In some embodiments, a nanostructure template coated with a silicon coating is provided. The silicon coating may include a non-conformal, more porous layer and a conformal, denser layer on the non-conformal, more porous layer. In some embodiments, two different deposition processes, e.g., a PECVD layer to deposit the non-conformal layer and a thermal CVD process to deposit the conformal layer, are used. Anodes including the nanostructures have longer cycle lifetimes than anodes made using either a PECVD or thermal CVD method alone.

Effects of Simulated Heat Waves with Strong Sudden Cooling Weather on ApoE Knockout Mice

PubMed Central

Zhang, Shuyu; Kuang, Zhengzhong; Zhang, Xiakun

2015-01-01

This study analyzes the mechanism of influence of heat waves with strong sudden cooling on cardiovascular diseases (CVD) in ApoE−/− mice. The process of heat waves with strong sudden cooling was simulated with a TEM1880 meteorological-environment simulation chamber according to the data obtained at 5 a.m. of 19 June 2006 to 11 p.m. of 22 June 2006. Forty-eight ApoE−/− mice were divided into six blocks based on their weight. Two mice from each block were randomly assigned to control, heat wave, temperature drop, and rewarming temperature groups. The experimental groups were transferred into the climate simulator chamber for exposure to the simulated heat wave process with strong sudden temperature drop. After 55, 59, and 75 h of exposure, the experimental groups were successively removed from the chamber to monitor physiological indicators. Blood samples were collected by decollation, and the hearts were harvested in all groups. The levels of heat stress factors (HSP60, SOD, TNF, sICAM-1, HIF-1α), cold stress factors (NE, EPI), vasoconstrictor factors (ANGII, ET-1, NO), and four items of blood lipid (TC, TG, HDL-C, and LDL-C) were measured in each ApoE−/− mouse. Results showed that the heat waves increased the levels of heat stress factors except SOD decreased, and decreased the levels of vasoconstrictor factors and blood lipid factors except TC increased. The strong sudden temperature drop in the heat wave process increased the levels of cold stress factors, vasoconstrictor factors and four blood lipid items (except the level of HDL-C which decreased) and decreased the levels of heat stress factors (except the level of SOD which increased). The analysis showed that heat waves could enhance atherosclerosis of ApoE−/− mice. The strong sudden temperature drop during the heat wave process increased the plasma concentrations of NE and ANGII, which indicates SNS activation, and resulted in increased blood pressure. NE and ANGII are vasoconstrictors involved in systemic vasoconstriction especially in the superficial areas of the body and conducive to increased blood pressure. The increase in the blood lipid levels of TG, LDL-C, TC, and LDL-C/HDL-C further aggravated CVD. This paper explored the influence mechanism of the heat waves with sudden cooling on CVD in ApoE−/− mice. PMID:26016434

Effects of Simulated Heat Waves with Strong Sudden Cooling Weather on ApoE Knockout Mice.

PubMed

Zhang, Shuyu; Kuang, Zhengzhong; Zhang, Xiakun

2015-05-26

This study analyzes the mechanism of influence of heat waves with strong sudden cooling on cardiovascular diseases (CVD) in ApoE-/- mice. The process of heat waves with strong sudden cooling was simulated with a TEM1880 meteorological-environment simulation chamber according to the data obtained at 5 a.m. of 19 June 2006 to 11 p.m. of 22 June 2006. Forty-eight ApoE-/- mice were divided into six blocks based on their weight. Two mice from each block were randomly assigned to control, heat wave, temperature drop, and rewarming temperature groups. The experimental groups were transferred into the climate simulator chamber for exposure to the simulated heat wave process with strong sudden temperature drop. After 55, 59, and 75 h of exposure, the experimental groups were successively removed from the chamber to monitor physiological indicators. Blood samples were collected by decollation, and the hearts were harvested in all groups. The levels of heat stress factors (HSP60, SOD, TNF, sICAM-1, HIF-1α), cold stress factors (NE, EPI), vasoconstrictor factors (ANGII, ET-1, NO), and four items of blood lipid (TC, TG, HDL-C, and LDL-C) were measured in each ApoE-/- mouse. Results showed that the heat waves increased the levels of heat stress factors except SOD decreased, and decreased the levels of vasoconstrictor factors and blood lipid factors except TC increased. The strong sudden temperature drop in the heat wave process increased the levels of cold stress factors, vasoconstrictor factors and four blood lipid items (except the level of HDL-C which decreased) and decreased the levels of heat stress factors (except the level of SOD which increased). The analysis showed that heat waves could enhance atherosclerosis of ApoE-/- mice. The strong sudden temperature drop during the heat wave process increased the plasma concentrations of NE and ANGII, which indicates SNS activation, and resulted in increased blood pressure. NE and ANGII are vasoconstrictors involved in systemic vasoconstriction especially in the superficial areas of the body and conducive to increased blood pressure. The increase in the blood lipid levels of TG, LDL-C, TC, and LDL-C/HDL-C further aggravated CVD. This paper explored the influence mechanism of the heat waves with sudden cooling on CVD in ApoE-/- mice.

Cardiovascular disease in autoimmune rheumatic diseases.

PubMed

Hollan, Ivana; Meroni, Pier Luigi; Ahearn, Joseph M; Cohen Tervaert, J W; Curran, Sam; Goodyear, Carl S; Hestad, Knut A; Kahaleh, Bashar; Riggio, Marcello; Shields, Kelly; Wasko, Mary C

2013-08-01

Various autoimmune rheumatic diseases (ARDs), including rheumatoid arthritis, spondyloarthritis, vasculitis and systemic lupus erythematosus, are associated with premature atherosclerosis. However, premature atherosclerosis has not been uniformly observed in systemic sclerosis. Furthermore, although experimental models of atherosclerosis support the role of antiphospholipid antibodies in atherosclerosis, there is no clear evidence of premature atherosclerosis in antiphospholipid syndrome (APA). Ischemic events in APA are more likely to be caused by pro-thrombotic state than by enhanced atherosclerosis. Cardiovascular disease (CVD) in ARDs is caused by traditional and non-traditional risk factors. Besides other factors, inflammation and immunologic abnormalities, the quantity and quality of lipoproteins, hypertension, insulin resistance/hyperglycemia, obesity and underweight, presence of platelets bearing complement protein C4d, reduced number and function of endothelial progenitor cells, apoptosis of endothelial cells, epigenetic mechanisms, renal disease, periodontal disease, depression, hyperuricemia, hypothyroidism, sleep apnea and vitamin D deficiency may contribute to the premature CVD. Although most research has focused on systemic inflammation, vascular inflammation may play a crucial role in the premature CVD in ARDs. It may be involved in the development and destabilization of both atherosclerotic lesions and of aortic aneurysms (a known complication of ARDs). Inflammation in subintimal vascular and perivascular layers appears to frequently occur in CVD, with a higher frequency in ARD than in non-ARD patients. It is possible that this inflammation is caused by infections and/or autoimmunity, which might have consequences for treatment. Importantly, drugs targeting immunologic factors participating in the subintimal inflammation (e.g., T- and B-cells) might have a protective effect on CVD. Interestingly, vasa vasorum and cardiovascular adipose tissue may play an important role in atherogenesis. Inflammation and complement depositions in the vessel wall are likely to contribute to vascular stiffness. Based on biopsy findings, also inflammation in the myocardium and small vessels may contribute to premature CVD in ARDs (cardiac ischemia and heart failure). There is an enormous need for an improved CVD prevention in ARDs. Studies examining the effect of DMARDs/biologics on vascular inflammation and CV risk are warranted. Copyright © 2013 Elsevier B.V. All rights reserved.

Both common and specialty mushrooms inhibit adhesion molecule expression and in vitro binding of monocytes to human aortic endothelial cells in a pro-inflammatory environment

PubMed Central

2010-01-01

Background Cardiovascular disease (CVD) is a leading cause of mortality in the United States as well as globally. Epidemiological studies show that regular fruit and vegetable consumption reduces CVD risk, in part, due to antioxidant activity and immunomodulation since oxidative stress and inflammation are features of atherogenesis. Accumulating evidence also shows that dietary fungi, viz., mushrooms, can protect against chronic disease by altering inflammatory environments such as those associated with CVD although most research has focused on specialty mushrooms. In this study, we tested the ability of both common and specialty mushrooms to inhibit cellular processes associated with CVD. Methods Human aortic endothelial cells (HAEC) were incubated overnight with control media with dimethylsulfoxide (DMSO) vehicle (1% v/v) or containing DMSO extracts of whole dehydrated mushrooms (0.1 mg/mL), which included Agaricus bisporus (white button and crimini), Lentinula edodes (shiitake), Pleurotus ostreatus (oyster), and Grifola frondosa (maitake). Monolayers were subsequently washed and incubated with medium alone or containing the pro-inflammatory cytokine IL-1β (5 ng/mL) for 6 h to upregulate pro-atherosclerotic adhesion molecules (AM). AM expression was assayed by ELISA and binding of U937 human monocytes pre-loaded with fluorescent dye was determined. Results White button mushrooms consistently reduced (p < 0.05) VCAM-1, ICAM-1, and E-selectin-1 expression, whereas other test mushrooms significantly modulated AM expression singly, collectively, or combinatorially. All mushrooms, however, significantly reduced binding of monocytes to both quiescent and cytokine-stimulated monolayers. Conclusion These data provide evidence that dietary mushrooms can inhibit cellular processes such as adhesion molecule expression and ultimate binding of monocytes to the endothelium under pro-inflammatory conditions, which are associated with CVD. As a result, these findings support the notion that dietary mushrooms can be protective against CVD. PMID:20637088

Saturated Fats Versus Polyunsaturated Fats Versus Carbohydrates for Cardiovascular Disease Prevention and Treatment

PubMed Central

Siri-Tarino, Patty W.; Chiu, Sally; Bergeron, Nathalie; Krauss, Ronald M.

2016-01-01

The effects of saturated fatty acids (SFAs) on cardiovascular disease (CVD) risk are modulated by the nutrients that replace them and their food matrices. Replacement of SFAs with polyunsaturated fatty acids has been associated with reduced CVD risk, although there is heterogeneity in both fatty acid categories. In contrast, replacement of SFAs with carbohydrates, particularly sugar, has been associated with no improvement or even a worsening of CVD risk, at least in part through effects on atherogenic dyslipidemia, a cluster of traits including small, dense low-density lipoprotein particles. The effects of dietary SFAs on insulin sensitivity, inflammation, vascular function, and thrombosis are less clear. There is growing evidence that SFAs in the context of dairy foods, particularly fermented dairy products, have neutral or inverse associations with CVD. Overall dietary patterns emphasizing vegetables, fish, nuts, and whole versus processed grains form the basis of heart-healthy eating and should supersede a focus on macronutrient composition. PMID:26185980

Saturated Fats Versus Polyunsaturated Fats Versus Carbohydrates for Cardiovascular Disease Prevention and Treatment.

PubMed

Siri-Tarino, Patty W; Chiu, Sally; Bergeron, Nathalie; Krauss, Ronald M

2015-01-01

The effects of saturated fatty acids (SFAs) on cardiovascular disease (CVD) risk are modulated by the nutrients that replace them and their food matrices. Replacement of SFAs with polyunsaturated fatty acids has been associated with reduced CVD risk, although there is heterogeneity in both fatty acid categories. In contrast, replacement of SFAs with carbohydrates, particularly sugar, has been associated with no improvement or even a worsening of CVD risk, at least in part through effects on atherogenic dyslipidemia, a cluster of traits including small, dense low-density lipoprotein particles. The effects of dietary SFAs on insulin sensitivity, inflammation, vascular function, and thrombosis are less clear. There is growing evidence that SFAs in the context of dairy foods, particularly fermented dairy products, have neutral or inverse associations with CVD. Overall dietary patterns emphasizing vegetables, fish, nuts, and whole versus processed grains form the basis of heart-healthy eating and should supersede a focus on macronutrient composition.

Gender Differences in Cardiovascular Disease: Hormonal and Biochemical Influences

PubMed Central

Pérez-López, Faustino R.; Larrad-Mur, Luis; Kallen, Amanda; Chedraui, Peter; Taylor, Hugh S.

2011-01-01

Objective Atherosclerosis is a complex process characterized by an increase in vascular wall thickness owing to the accumulation of cells and extracellular matrix between the endothelium and the smooth muscle cell wall. There is evidence that females are at lower risk of developing cardiovascular disease (CVD) as compared to males. This has led to an interest in examining the contribution of genetic background and sex hormones to the development of CVD. The objective of this review is to provide an overview of factors, including those related to gender, that influence CVD. Methods Evidence analysis from PubMed and individual searches concerning biochemical and endocrine influences and gender differences, which affect the origin and development of CVD. Results Although still controversial, evidence suggests that hormones including estradiol and androgens are responsible for subtle cardiovascular changes long before the development of overt atherosclerosis. Conclusion Exposure to sex hormones throughout an individual's lifespan modulates many endocrine factors involved in atherosclerosis. PMID:20460551

Formation of Aluminide Coatings on Fe-Based Alloys by Chemical Vapor Deposition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Ying; Pint, Bruce A; Cooley, Kevin M

2008-01-01

Aluminide and Al-containing coatings were synthesized on commercial ferritic (P91) and austenitic (304L) alloys via a laboratory chemical vapor deposition (CVD) procedure for rigorous control over coating composition, purity and microstructure. The effect of the CVD aluminizing parameters such as temperature, Al activity, and post-aluminizing anneal on coating growth was investigated. Two procedures involving different Al activities were employed with and without including Cr-Al pellets in the CVD reactor to produce coatings with suitable thickness and composition for coating performance evaluation. The phase constitution of the as-synthesized coatings was assessed with the aid of a combination of X-ray diffraction, electronmore » probe microanalysis, and existing phase diagrams. The mechanisms of formation of these CVD coatings on the Fe-based alloys are discussed, and compared with nickel aluminide coatings on Ni-base superalloys. In addition, Cr-Al pellets were replaced with Fe-Al metals in some aluminizing process runs and similar coatings were achieved.« less

Chemical reactivity of CVC and CVD SiC with UO 2 at high temperatures

DOE PAGES

Silva, Chinthaka M.; Katoh, Yutai; Voit, Stewart L.; ...

2015-02-11

Two types of silicon carbide (SiC) synthesized using two different vapor deposition processes were embedded in UO 2 pellets and evaluated for their potential chemical reaction with UO 2. While minor reactivity between chemical-vapor-composited (CVC) SiC and UO 2 was observed at comparatively low temperatures of 1100 and 1300 C, chemical-vapor-deposited (CVD) SiC did not show any such reactivity, according to microstructural investigations. But, both CVD and CVC SiCs showed some reaction with UO 2 at a higher temperature (1500 C). Elemental maps supported by phase maps obtained using electron backscatter diffraction indicated that CVC SiC was more reactive thanmore » CVD SiC at 1500 C. Moreover, this investigation indicated the formation of uranium carbides and uranium silicide chemical phases such as UC, USi 2, and U 3Si 2 as a result of SiC reaction with UO 2.« less

Oxidative stress-induced telomeric erosion as a mechanism underlying airborne particulate matter-related cardiovascular disease

PubMed Central

2012-01-01

Particulate matter (PM) pollution is responsible for hundreds of thousands of deaths worldwide, the majority due to cardiovascular disease (CVD). While many potential pathophysiological mechanisms have been proposed, there is not yet a consensus as to which are most important in causing pollution-related morbidity/mortality. Nor is there consensus regarding which specific types of PM are most likely to affect public health in this regard. One toxicological mechanism linking exposure to airborne PM with CVD outcomes is oxidative stress, a contributor to the development of CVD risk factors including atherosclerosis. Recent work suggests that accelerated shortening of telomeres and, thus, early senescence of cells may be an important pathway by which oxidative stress may accelerate biological aging and the resultant development of age-related morbidity. This pathway may explain a significant proportion of PM-related adverse health outcomes, since shortened telomeres accelerate the progression of many diseases. There is limited but consistent evidence that vehicular emissions produce oxidative stress in humans. Given that oxidative stress is associated with accelerated erosion of telomeres, and that shortened telomeres are linked with acceleration of biological ageing and greater incidence of various age-related pathology, including CVD, it is hypothesized that associations noted between certain pollution types and sources and oxidative stress may reflect a mechanism by which these pollutants result in CVD-related morbidity and mortality, namely accelerated aging via enhanced erosion of telomeres. This paper reviews the literature providing links among oxidative stress, accelerated erosion of telomeres, CVD, and specific sources and types of air pollutants. If certain PM species/sources might be responsible for adverse health outcomes via the proposed mechanism, perhaps the pathway to reducing mortality/morbidity from PM would become clearer. Not only would pollution reduction imperatives be more focused, but interventions which could reduce oxidative stress would become all the more important. PMID:22713210

Large scale integration of CVD-graphene based NEMS with narrow distribution of resonance parameters

NASA Astrophysics Data System (ADS)

Arjmandi-Tash, Hadi; Allain, Adrien; (Vitto Han, Zheng; Bouchiat, Vincent

2017-06-01

We present a novel method for the fabrication of the arrays of suspended micron-sized membranes, based on monolayer pulsed-CVD graphene. Such devices are the source of an efficient integration of graphene nano-electro-mechanical resonators, compatible with production at the wafer scale using standard photolithography and processing tools. As the graphene surface is continuously protected by the same polymer layer during the whole process, suspended graphene membranes are clean and free of imperfections such as deposits, wrinkles and tears. Batch fabrication of 100 μm-long multi-connected suspended ribbons is presented. At room temperature, mechanical resonance of electrostatically-actuated devices show narrow distribution of their characteristic parameters with high quality factor and low effective mass and resonance frequencies, as expected for low stress and adsorbate-free membranes. Upon cooling, a sharp increase of both resonant frequency and quality factor is observed, enabling to extract the thermal expansion coefficient of CVD graphene. Comparison with state-of-the-art graphene NEMS is presented.

Investigation of chemical vapor deposition of garnet films for bubble domain memories

NASA Technical Reports Server (NTRS)

Besser, P. J.; Hamilton, T. N.

1973-01-01

The important process parameters and control required to grow reproducible device quality ferrimagnetic films by chemical vapor deposition (CVD) were studied. The investigation of the critical parameters in the CVD growth process led to the conclusion that the required reproducibility of film properties cannot be achieved with individually controlled separate metal halide sources. Therefore, the CVD growth effort was directed toward replacement of the halide sources with metallic sources with the ultimate goal being the reproducible growth of complex garnet compositions utilizing a single metal alloy source. The characterization of the YGdGaIG films showed that certain characteristics of this material, primarily the low domain wall energy and the large temperature sensitivity, severely limited its potential as a useful material for bubble domain devices. Consequently, at the time of the change from halide to metallic sources, the target film compositions were shifted to more useful materials such as YGdTmGaIG, YEuGaIG and YSmGaIG.

Common Carotid Artery Diameter and Risk of Cardiovascular Events and Mortality: Pooled Analyses of Four Cohort Studies.

PubMed

Sedaghat, Sanaz; van Sloten, Thomas T; Laurent, Stéphane; London, Gérard M; Pannier, Bruno; Kavousi, Maryam; Mattace-Raso, Francesco; Franco, Oscar H; Boutouyrie, Pierre; Ikram, M Arfan; Stehouwer, Coen D A

2018-05-21

Carotid arterial diameter enlargement is a manifestation of arterial remodeling and may be a risk factor for cardiovascular disease (CVD). We evaluated the association between carotid artery diameter and risk of stroke, coronary heart disease, CVD, and all-cause mortality and explored whether the associations could be explained by processes involved in arterial remodeling, that is, blood pressure-related media thickening, arterial stiffness, arterial wall stress, and atherosclerosis. We included 4887 participants (mean age 67±9 years; 54% women) from 4 cohort studies: Rotterdam Study, NEPHROTEST, Hoorn Study, and a study by Blacher et al. Common carotid artery properties were measured using echotracking. Incident cases were recorded based on medical records. We used Cox proportional hazard models adjusting for cardiovascular risk factors and estimates of processes underlying arterial remodeling. During follow-up (mean, 11 years), 379 (8%) individuals had a stroke, 516 had a (11%) coronary heart disease, 807 had a (17%) CVD, and 1486 (30%) had died. After adjustment for cardiovascular risk factors, individuals in the highest tertile of carotid diameter (diameter >8 mm) compared with those in the lowest tertile (diameter <7 mm) had a higher incidence of stroke (hazard ratio, 1.5; 95% confidence interval, 1.1-2.0). From all estimates of processes underlying arterial remodeling, adjustment for carotid intima-media thickness attenuated this association (hazard ratio after adjustment for intima-media thickness, 1.2; 95% confidence interval, 0.9-1.6). Larger carotid diameter was associated with risk of CVD and mortality but not clearly with coronary heart disease risk. We showed that a larger carotid diameter is associated with incident stroke, CVD, and mortality. Carotid intima-media thickness, a measure of blood pressure-related media thickening, partially explained the association with stroke incidence. © 2018 American Heart Association, Inc.

Enhanced Tunnel Spin Injection into Graphene using Chemical Vapor Deposited Hexagonal Boron Nitride

PubMed Central

Kamalakar, M. Venkata; Dankert, André; Bergsten, Johan; Ive, Tommy; Dash, Saroj P.

2014-01-01

The van der Waals heterostructures of two-dimensional (2D) atomic crystals constitute a new paradigm in nanoscience. Hybrid devices of graphene with insulating 2D hexagonal boron nitride (h-BN) have emerged as promising nanoelectronic architectures through demonstrations of ultrahigh electron mobilities and charge-based tunnel transistors. Here, we expand the functional horizon of such 2D materials demonstrating the quantum tunneling of spin polarized electrons through atomic planes of CVD grown h-BN. We report excellent tunneling behavior of h-BN layers together with tunnel spin injection and transport in graphene using ferromagnet/h-BN contacts. Employing h-BN tunnel contacts, we observe enhancements in both spin signal amplitude and lifetime by an order of magnitude. We demonstrate spin transport and precession over micrometer-scale distances with spin lifetime up to 0.46 nanosecond. Our results and complementary magnetoresistance calculations illustrate that CVD h-BN tunnel barrier provides a reliable, reproducible and alternative approach to address the conductivity mismatch problem for spin injection into graphene. PMID:25156685

Relation of Gemfibrozil Treatment and High Density Lipoprotein (HDL) Subpopulation Profile with Cardiovascular Events in the Veterans Affairs HDL Intervention Trial (VA-HIT)

PubMed Central

Asztalos, Bela F.; Collins, Dorothea; Horvath, Katalin V.; Bloomfield, Hanna E.; Robins, Sander J.; Schaefer, Ernst J.

2007-01-01

Objective The significant cardiovascular disease (CVD) event reduction in VA-HIT could not be fully explained by the 6% increase in HDL-C with the fibrate, gemfibrozil. We examined whether measurement of HDL subpopulations provided additional information relative to CVD-risk reduction. Methods and Results HDL subpopulations were characterized by 2-dimensional gel-electrophoresis in subjects who were treated with gemfibrozil (n=754) or placebo (n=741). In this study, samples obtained at the 3-month visit were used and data were analyzed prospectively using CVD events (CHD death, MI, or stroke) during the 5.1 years follow up. Analyses in the gemfibrozil arm showed that subjects with recurrent CVD events had significantly higher preβ-1 and had significantly lower α-1 and α-2 HDL levels than those without such events. Preβ-1 level was a significant positive predictor; α-1 and α-2 levels were significant negative risk factors for future CVD events. α-2 level was superior to HDL-C level in CVD-risk assessment after adjustment for established risk factors. Gemfibrozil treatment was associated with 3%-6% decreases in the small, lipid-poor preβ-1 HDL and in the large, lipid-rich α-1 and α-2 HDL and with increases in the small α-3 (3%) and preα-3 (16%) HDLs. Conclusions While the use of gemfibrozil has been associated with reduction in CVD events in VA-HIT, HDL subpopulation analysis indicates that gemfibrozil-mediated improvement in CVD risk might not be the result of its effects on HDL. It is quite possible that much of the cardiovascular benefits of gemfibrozil are due to a much wider spectrum of effects on metabolic processes that is not reflected by changes in blood lipids and HDL subpopulations. PMID:18078862

Economic assessment of single-walled carbon nanotube processes

NASA Astrophysics Data System (ADS)

Isaacs, J. A.; Tanwani, A.; Healy, M. L.; Dahlben, L. J.

2010-02-01

The carbon nanotube market is steadily growing and projected to reach 1.9 billion by 2010. This study examines the economics of manufacturing single-walled carbon nanotubes (SWNT) using process-based cost models developed for arc, CVD, and HiPco processes. Using assumed input parameters, manufacturing costs are calculated for 1 g SWNT for arc, CVD, and HiPco, totaling 1,906, 1,706, and 485, respectively. For each SWNT process, the synthesis and filtration steps showed the highest costs, with direct labor as a primary cost driver. Reductions in production costs are calculated for increased working hours per day and for increased synthesis reaction yield (SRY) in each process. The process-based cost models offer a means for exploring opportunities for cost reductions, and provide a structured system for comparisons among alternative SWNT manufacturing processes. Further, the models can be used to comprehensively evaluate additional scenarios on the economics of environmental, health, and safety best manufacturing practices.

Confronting the Growing Crisis of Cardiovascular Disease and Heart Health Among Aboriginal Peoples in Canada.

PubMed

Reading, Jeffrey

2015-09-01

Although the prevalence of cardiovascular disease (CVD) has been decreasing worldwide, Aboriginal populations of Canada (including First Nations, Métis, and Inuit Peoples) continue to experience a rapidly growing burden of CVD morbidity and mortality. This article provides a succinct summary of the current crisis of CVD among Canadian Aboriginal peoples, including how and why it originated, elucidates the underlying population health risks driving higher rates of aboriginal CVD, and articulates the urgent need for community-engagement solutions and innovations in the areas of prevention, treatment and care, rehabilitation services, aboriginal-specific CVD surveillance, and advanced knowledge. In the past, particularly in rural and remote communities, Aboriginal Peoples' survival depended (and often still does) on hunting, fishing, and other forms of traditional food-gathering. However, the traditional life is being changed for many Aboriginal communities, resulting in significantly impaired dietary options and the undermining of a long-established way of life that was healthy and physically active. Reclaiming CVD health and well-being requires replacement of the calorie-dense and nutritionally inadequate diets of highly processed store-bought foods with fresh and nutritionally balanced diets and addressing the physically inactive lifestyles that together have contributed to an increase in CVD prevalence. Furthermore, disparities exist for hospital-based treatment experiences for patients from areas with high proportions of Aboriginal Peoples vs those with low proportions of Aboriginal Peoples. It is crucial to investigate and develop concrete plans to reduce the burden of CVDs among Aboriginal Peoples by improved prevention and treatment in a community-centred way. Copyright © 2015 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

Use of focus groups to develop methods to communicate cardiovascular disease risk and potential for risk reduction to people with type 2 diabetes.

PubMed

Price, Hermione C; Dudley, Christina; Barrow, Beryl; Kennedy, Ian; Griffin, Simon J; Holman, Rury R

2009-10-01

People need to perceive a risk in order to build an intention-to-change behaviour yet our ability to interpret information about risk is highly variable. We aimed to use a user-centred design process to develop an animated interface for the UK Prospective Diabetes Study (UKPDS) Risk Engine to illustrate cardiovascular disease (CVD) risk and the potential to reduce this risk. In addition, we sought to use the same approach to develop a brief lifestyle advice intervention. Three focus groups were held. Participants were provided with examples of materials used to communicate CVD risk and a leaflet containing a draft brief lifestyle advice intervention and considered their potential to increase motivation-to-change behaviours including diet, physical activity, and smoking in order to reduce CVD risk. Discussions were tape-recorded, transcribed and coded and recurring themes sought. Sixty-two percent of participants were male, mean age was 66 years (range = 47-76 years) and median age at leaving full-time education was 18 years (range = 15-40 years). Sixteen had type 2 diabetes and none had a prior history of CVD. Recurring themes from focus group discussions included the following: being less numerate is common, CVD risk reduction is important and a clear visual representation aids comprehension. A simple animated interface of the UKPDS Risk Engine to illustrate CVD risk and the potential for reducing this risk has been developed for use as a motivational tool, along with a brief lifestyle advice intervention. Future work will investigate whether use of this interactive version of the UKPDS Risk Engine and brief lifestyle advice is associated with increased behavioural intentions and changes in health behaviours designed to reduce CVD risk.

Shared genetic regulatory networks for cardiovascular disease and type 2 diabetes in multiple populations of diverse ethnicities in the United States

PubMed Central

Zhang, Guanglin; Codoni, Veronica; Yang, Jun; Wilson, James G.; Levy, Daniel; Lusis, Aldons J.; Liu, Simin; Yang, Xia

2017-01-01

Cardiovascular diseases (CVD) and type 2 diabetes (T2D) are closely interrelated complex diseases likely sharing overlapping pathogenesis driven by aberrant activities in gene networks. However, the molecular circuitries underlying the pathogenic commonalities remain poorly understood. We sought to identify the shared gene networks and their key intervening drivers for both CVD and T2D by conducting a comprehensive integrative analysis driven by five multi-ethnic genome-wide association studies (GWAS) for CVD and T2D, expression quantitative trait loci (eQTLs), ENCODE, and tissue-specific gene network models (both co-expression and graphical models) from CVD and T2D relevant tissues. We identified pathways regulating the metabolism of lipids, glucose, and branched-chain amino acids, along with those governing oxidation, extracellular matrix, immune response, and neuronal system as shared pathogenic processes for both diseases. Further, we uncovered 15 key drivers including HMGCR, CAV1, IGF1 and PCOLCE, whose network neighbors collectively account for approximately 35% of known GWAS hits for CVD and 22% for T2D. Finally, we cross-validated the regulatory role of the top key drivers using in vitro siRNA knockdown, in vivo gene knockout, and two Hybrid Mouse Diversity Panels each comprised of >100 strains. Findings from this in-depth assessment of genetic and functional data from multiple human cohorts provide strong support that common sets of tissue-specific molecular networks drive the pathogenesis of both CVD and T2D across ethnicities and help prioritize new therapeutic avenues for both CVD and T2D. PMID:28957322

Projected Impact of a Sodium Consumption Reduction Initiative in Argentina: An Analysis from the CVD Policy Model – Argentina

PubMed Central

Konfino, Jonatan; Mekonnen, Tekeshe A.; Coxson, Pamela G.; Ferrante, Daniel; Bibbins-Domingo, Kirsten

2013-01-01

Background Cardiovascular disease (CVD) is the leading cause of death in adults in Argentina. Sodium reduction policies targeting processed foods were implemented in 2011 in Argentina, but the impact has not been evaluated. The aims of this study are to use Argentina-specific data on sodium excretion and project the impact of Argentina’s sodium reduction policies under two scenarios - the 2-year intervention currently being undertaken or a more persistent 10 year sodium reduction strategy. Methods We used Argentina-specific data on sodium excretion by sex and projected the impact of the current strategy on sodium consumption and blood pressure decrease. We assessed the projected impact of sodium reduction policies on CVD using the Cardiovascular Disease (CVD) Policy Model, adapted to Argentina, modeling two alternative policy scenarios over the next decade. Results Our study finds that the initiative to reduce sodium consumption currently in place in Argentina will have substantial impact on CVD over the next 10 years. Under the current proposed policy of 2-year sodium reduction, the mean sodium consumption is projected to decrease by 319–387 mg/day. This decrease is expected to translate into an absolute reduction of systolic blood pressure from 0.93 mmHg to 1.81 mmHg. This would avert about 19,000 all-cause mortality, 13,000 total myocardial infarctions, and 10,000 total strokes over the next decade. A more persistent sodium reduction strategy would yield even greater CVD benefits. Conclusion The impact of the Argentinean initiative would be effective in substantially reducing mortality and morbidity from CVD. This paper provides evidence-based support to continue implementing strategies to reduce sodium consumption at a population level. PMID:24040085

Effects of a cardiovascular risk reduction intervention with psychobehavioral strategies for Korean adults with type 2 diabetes and metabolic syndrome.

PubMed

Kim, Chun-Ja; Kim, Dae-Jung; Park, Hyung-Ran

2011-01-01

Type 2 diabetes mellitus (DM) and metabolic syndrome are associated with high risk of cardiovascular disease (CVD) and depression. Although lifestyle modifications including regular exercise and weight control are recommended as a primary approach to glycemic control and CVD risk reduction for people with DM and/or metabolic syndrome, little is known concerning the effects of CVD risk reduction interventions using psychobehavioral strategies in this population. This pilot study investigated the effects of a 16-week CVD risk reduction intervention in Korean adults with type 2 DM and metabolic syndrome. A prospective, pretest and posttest, controlled, quasi-experimental design enrolled a convenience sample of 43 Korean adults with type 2 DM and metabolic syndrome at a university hospital. The adults in the intervention group participated in a 16-week CVD risk reduction intervention consisting of 150 minutes of regular exercise per week; 200- to 300-kcal reduced daily diet for weight control; one-on-one psychobehavioral counseling based on constructs from the Transtheoretical Model such as processes of change, self-efficacy, and decisional balance; and telephone coaching for behavioral modification. Participants in the control group received a booklet with basic diabetic education as part of their routine care. Repeated-measures analysis of variance was used for analyzing the effects of the CVD risk reduction intervention on cardiometabolic risk factors including the UK Prospective Diabetes Study score for 10-year CVD risk, glycated hemoglobin (HbA1c), and depression. The intervention group showed significant reductions (P < .05) at 16 weeks, compared with the control group on the UK Prospective Diabetes Study fatal risk scale (-1.73% vs -0.04%), triglycerides (-38.5 vs -15.1 mg/dL), fasting plasma glucose (-29.24 vs +1.77 mg/dL), HbA1c (-0.37% vs +0.17%), and depression (score, -3.24 vs 1.40) measurements. This pilot study yielded evidence for the beneficial impact of the CVD risk reduction intervention for Korean adults with type 2 DM and metabolic syndrome on improved glycemic control, reduced CVD risk, and depression.

Skin Autofluorescence and Mortality in Patients on Peritoneal Dialysis

PubMed Central

Mácsai, Emília; Benke, Attila; Kiss, István

2015-01-01

Abstract Skin autofluorescence (SAF) is a proven prognostic factor of mortality in hemodialysis patients. Traditional and nontraditional risk factors are almost equivalent in peritoneal dialysis (PD), and cardiovascular disease (CVD) is the leading cause of death. Moreover, peritoneal glucose absorption accelerates the degenerative processes of connective tissues as in diabetes. In our study, we examined the predictive value of SAF for total mortality in the PD population. Data were collected from 198 prevalently adult Caucasian PD patients. One hundred twenty-six patients (mean age 66.2 y, men [n = 73], diabetes ratio 75/126) had anamnestic CVD (coronary heart disease, cerebrovascular disease, peripheral arterial disease). Initially, we evaluated factors affecting SAF and CVD by multivariate linear regression. Survival rates were estimated by recording clinical and demographic data associated with mortality during a 36-month follow-up using the Kaplan–Meier method. Analyses were further stratified based on the presence or absence of CVD and SAF levels above or below the upper tercile 3.61 arbitrary units. Skin autofluorescence was influenced by CVD (P < 0.01, 95% confidence interval [CI] 0.1–0.5) and white blood cell counts (P < 0.001, 95% CI 0.031–0.117). According to the Spearman correlation, SAF correlated with peritoneal cumulative glucose exposure (P = 0.02) and elapsed time in PD (P = 0.008). CVD correlated with age (P < 0.001, 95% CI 1.24–1.65) and diabetes (P < 0.001, 95% CI 2.58–10.66). More deaths were observed in the high SAF group than in the low SAF group (34/68 vs 44/130; P = 0.04). Comparing the CVD(−) low SAF group survival (mean 33.9 mos, standard error [SE] 1.39) to CVD(+) low SAF (mean 30.5 mos, SE 1.37, P = 0.03) and to CVD(+) high SAF group (mean 27.1 mos, SE 1.83, P = 0.001), the difference was significant. In conclusion, among PD patients, SAF values over 3.61 arbitrary units seem to be a predictor of mortality. The relationship among peritoneal glucose exposure, CVD, and diabetes suggests its suitability to characterize systemic cumulative glucose load in this patient population. PMID:26559261

Evaluation of the quality of care of a multi-disciplinary Risk Factor Assessment and Management Programme for Hypertension (RAMP-HT).

PubMed

Yu, Esther Yee Tak; Wan, Eric Yuk Fai; Chan, Karina Hiu Yen; Wong, Carlos King Ho; Kwok, Ruby Lai Ping; Fong, Daniel Yee Tak; Lam, Cindy Lo Kuen

2015-06-19

There is some evidence to support a risk-stratified, multi-disciplinary approach to manage patients with hypertension in primary care. The aim of this study is to evaluate the quality of care (QOC) of a multi-disciplinary Risk Assessment and Management Programme for Hypertension (RAMP-HT) for hypertensive patients in busy government-funded primary care clinics in Hong Kong. The objectives are to develop an evidence-based, structured and comprehensive evaluation framework on quality of care, to enhance the QOC of the RAMP-HT through an audit spiral of two evaluation cycles and to determine the effectiveness of the programme in reducing cardiovascular disease (CVD) risk. A longitudinal study is conducted using the Action Learning and Audit Spiral methodologies to measure whether pre-set target standards of care intended by the RAMP-HT are achieved. A structured evaluation framework on the quality of structure, process and outcomes of care has been developed based on the programme objectives and literature review in collaboration with the programme workgroup and health service providers. Each participating clinic is invited to complete a structure of care evaluation questionnaire in each evaluation cycle. The data of all patients who have enrolled into the RAMP-HT in the pre-defined evaluation periods are used for the evaluation of the process and outcomes of care in each evaluation cycle. For evaluation of the effectiveness of RAMP-HT, the primary outcomes including blood pressure (both systolic and diastolic), low-density lipoprotein cholesterol and estimated 10-year CVD risk of RAMP-HT participants are compared to those of hypertensive patients in usual care without RAMP-HT. The QOC and effectiveness of the RAMP-HT in improving clinical and patient-reported outcomes for patients with hypertension in normal primary care will be determined. Possible areas for quality enhancement and standards of good practice will be established to inform service planning and policy decision making.

Surface functionalization of 3D-printed plastics via initiated chemical vapor deposition

PubMed Central

Cheng, Christine

2017-01-01

3D printing is a useful fabrication technique because it offers design flexibility and rapid prototyping. The ability to functionalize the surfaces of 3D-printed objects allows the bulk properties, such as material strength or printability, to be chosen separately from surface properties, which is critical to expanding the breadth of 3D printing applications. In this work, we studied the ability of the initiated chemical vapor deposition (iCVD) process to coat 3D-printed shapes composed of poly(lactic acid) and acrylonitrile butadiene styrene. The thermally insulating properties of 3D-printed plastics pose a challenge to the iCVD process due to large thermal gradients along the structures during processing. In this study, processing parameters such as the substrate temperature and the filament temperature were systematically varied to understand how these parameters affect the uniformity of the coatings along the 3D-printed objects. The 3D-printed objects were coated with both hydrophobic and hydrophilic polymers. Contact angle goniometry and X-ray photoelectron spectroscopy were used to characterize the functionalized surfaces. Our results can enable the use of iCVD to functionalize 3D-printed materials for a range of applications such as tissue scaffolds and microfluidics. PMID:28875099

An integrated general practice and pharmacy-based intervention to promote the use of appropriate preventive medications among individuals at high cardiovascular disease risk: protocol for a cluster randomized controlled trial.

PubMed

Hayek, Adina; Joshi, Rohina; Usherwood, Tim; Webster, Ruth; Kaur, Baldeep; Saini, Bandana; Armour, Carol; Krass, Ines; Laba, Tracey-Lea; Reid, Christopher; Shiel, Louise; Hespe, Charlotte; Hersch, Fred; Jan, Stephen; Lo, Serigne; Peiris, David; Rodgers, Anthony; Patel, Anushka

2016-09-23

Cardiovascular diseases (CVD) are responsible for significant morbidity, premature mortality, and economic burden. Despite established evidence that supports the use of preventive medications among patients at high CVD risk, treatment gaps remain. Building on prior evidence and a theoretical framework, a complex intervention has been designed to address these gaps among high-risk, under-treated patients in the Australian primary care setting. This intervention comprises a general practice quality improvement tool incorporating clinical decision support and audit/feedback capabilities; availability of a range of CVD polypills (fixed-dose combinations of two blood pressure lowering agents, a statin ± aspirin) for prescription when appropriate; and access to a pharmacy-based program to support long-term medication adherence and lifestyle modification. Following a systematic development process, the intervention will be evaluated in a pragmatic cluster randomized controlled trial including 70 general practices for a median period of 18 months. The 35 general practices in the intervention group will work with a nominated partner pharmacy, whereas those in the control group will provide usual care without access to the intervention tools. The primary outcome is the proportion of patients at high CVD risk who were inadequately treated at baseline who achieve target blood pressure (BP) and low-density lipoprotein cholesterol (LDL-C) levels at the study end. The outcomes will be analyzed using data from electronic medical records, utilizing a validated extraction tool. Detailed process and economic evaluations will also be performed. The study intends to establish evidence about an intervention that combines technological innovation with team collaboration between patients, pharmacists, and general practitioners (GPs) for CVD prevention. Australian New Zealand Clinical Trials Registry ACTRN12616000233426.

Selected Activities of Citrus Maxima Merr. Fruits on Human Endothelial Cells: Enhancing Cell Migration and Delaying Cellular Aging

PubMed Central

Buachan, Paiwan; Chularojmontri, Linda; Wattanapitayakul, Suvara K.

2014-01-01

Endothelial injury and damage as well as accumulated reactive oxygen species (ROS) in aging play a significant role in the development of cardiovascular disease (CVD). Recent studies show an association of high citrus fruit intake with a lower risk of CVD and stroke but the mechanisms involved are not fully understood. This study investigated the effects of pummelo (Citrus maxima Merr. var. Tubtim Siam, CM) fruit extract on human umbilical vein endothelial cell (HUVECs) migration and aging. The freeze-dried powder of fruit extract was characterized for antioxidant capacity (FRAP assay) and certain natural antioxidants, including ascorbic acid, gallic acid, hesperidin, and naringin (HPLC). Short-term (48 h) co-cultivation of HUVECs with CM enhanced cell migration as evaluated by a scratch wound assay and Boyden chamber assay. A long-term treatment with CM for 35 days significantly increased HUVEC proliferation capability as indicated by population doubling level (PDL). CM also delayed the onset of aging phenotype shown by senescence-associated β-galactosidase (SA-β-gal) staining. Furthermore, CM was able to attenuate increased ROS levels in aged cells when determined by 2′,7′-dichlorodihydrofluorescein diacetate (DCDHF) while eNOS mRNA expression was increased but the eNOS protein level was not changed. Thus, further in vivo and clinical studies are warranted to support the use of pummelo as a functional fruit for endothelial health and CVD risk reduction. PMID:24763109

Does dairy calcium intake enhance weight loss among overweight diabetic patients?

PubMed

Shahar, Danit R; Abel, Relly; Elhayany, Asher; Vardi, Hillel; Fraser, Drora

2007-03-01

To examine the effect of dairy calcium consumption on weight loss and improvement in cardiovascular disease (CVD) and diabetes indicators among overweight diabetic patients. This was an ancillary study of a 6-month randomized clinical trial assessing the effect of three isocaloric diets in type 2 diabetic patients: 1) mixed glycemic index carbohydrate diet, 2) low-glycemic index diet, and 3) modified Mediterranean diet. Low-fat dairy product consumption varied within and across the groups by personal choice. Dietary intake, weight, CVD risk factors, and diabetes indexes were measured at baseline and at 6 months. A total of 259 diabetic patients were recruited with an average BMI >31 kg/m2 and mean age of 55 years. No difference was found at baseline between the intervention groups in CVD risk factors, diabetes indicators, macronutrient intake, and nutrient intake from dairy products. Dairy calcium intake was associated with percentage of weight loss. Among the high tertile of dairy calcium intake, the odds ratio for weight loss of >8% was 2.4, P = 0.04, compared with the first tertile, after controlling for nondairy calcium intake, diet type, and the change in energy intake from baseline. No association was noted between dairy calcium and other health indexes except for triglyceride levels. A diet rich in dairy calcium intake enhances weight reduction in type 2 diabetic patients. Such a diet could be tried in diabetic patients, especially those with difficulty adhering to other weight reduction diets.

Cardiac Dysfunction and Oxidative Stress in the Metabolic Syndrome: an Update on Antioxidant Therapies

PubMed Central

Ilkun, Olesya; Boudina, Sihem

2013-01-01

The metabolic syndrome (MetS) is a cluster of risk factors including obesity, insulin resistance, dyslipidemia, elevated blood pressure and glucose intolerance. The MetS increases the risk for cardiovascular disease (CVD) and type 2 diabetes. Each component of the MetS causes cardiac dysfunction and their combination carries additional risk. The mechanisms underlying cardiac dysfunction in the MetS are complex and might include lipid accumulation, increased fibrosis and stiffness, altered calcium homeostasis, abnormal autophagy, altered substrate utilization, mitochondrial dysfunction and increased oxidative stress. Mitochondrial and extra-mitochondrial sources of reactive oxygen species (ROS) and reduced antioxidant defense mechanisms characterize the myocardium of humans and animals with the MetS. The mechanisms for increased cardiac oxidative stress in the MetS are not fully understood but include increased fatty acid oxidation, mitochondrial dysfunction and enhanced NADPH oxidase activity. Therapies aimed to reduce oxidative stress and enhance antioxidant defense have been employed to reduce cardiac dysfunction in the MetS in animals. In contrast, large scale clinical trials using antioxidants therapies for the treatment of CVD have been disappointing because of the lack of efficacy and undesired side effects. The focus of this review is to summarize the current knowledge about the mechanisms underlying cardiac dysfunction in the MetS with a special interest in the role of oxidative stress. Finally, we will update the reader on the results obtained with natural antioxidant and mitochondria-targeted antioxidant therapies for the treatment of CVD in the MetS. PMID:23323621

Selected activities of Citrus maxima Merr. fruits on human endothelial cells: enhancing cell migration and delaying cellular aging.

PubMed

Buachan, Paiwan; Chularojmontri, Linda; Wattanapitayakul, Suvara K

2014-04-21

Endothelial injury and damage as well as accumulated reactive oxygen species (ROS) in aging play a significant role in the development of cardiovascular disease (CVD). Recent studies show an association of high citrus fruit intake with a lower risk of CVD and stroke but the mechanisms involved are not fully understood. This study investigated the effects of pummelo (Citrus maxima Merr. var. Tubtim Siam, CM) fruit extract on human umbilical vein endothelial cell (HUVECs) migration and aging. The freeze-dried powder of fruit extract was characterized for antioxidant capacity (FRAP assay) and certain natural antioxidants, including ascorbic acid, gallic acid, hesperidin, and naringin (HPLC). Short-term (48 h) co-cultivation of HUVECs with CM enhanced cell migration as evaluated by a scratch wound assay and Boyden chamber assay. A long-term treatment with CM for 35 days significantly increased HUVEC proliferation capability as indicated by population doubling level (PDL). CM also delayed the onset of aging phenotype shown by senescence-associated β-galactosidase (SA-β-gal) staining. Furthermore, CM was able to attenuate increased ROS levels in aged cells when determined by 2',7'-dichlorodihydrofluorescein diacetate (DCDHF) while eNOS mRNA expression was increased but the eNOS protein level was not changed. Thus, further in vivo and clinical studies are warranted to support the use of pummelo as a functional fruit for endothelial health and CVD risk reduction.

Ultra-large suspended graphene as a highly elastic membrane for capacitive pressure sensors

NASA Astrophysics Data System (ADS)

Chen, Yu-Min; He, Shih-Ming; Huang, Chi-Hsien; Huang, Cheng-Chun; Shih, Wen-Pin; Chu, Chun-Lin; Kong, Jing; Li, Ju; Su, Ching-Yuan

2016-02-01

In this work, we fabricate ultra-large suspended graphene membranes, where stacks of a few layers of graphene could be suspended over a circular hole with a diameter of up to 1.5 mm, with a diameter to thickness aspect ratio of 3 × 105, which is the record for free-standing graphene membranes. The process is based on large crystalline graphene (~55 μm) obtained using a chemical vapor deposition (CVD) method, followed by a gradual solvent replacement technique. Combining a hydrogen bubbling transfer approach with thermal annealing to reduce polymer residue results in an extremely clean surface, where the ultra-large suspended graphene retains the intrinsic features of graphene, including phonon response and an enhanced carrier mobility (200% higher than that of graphene on a substrate). The highly elastic mechanical properties of the graphene membrane are demonstrated, and the Q-factor under 2 MHz stimulation is measured to be 200-300. A graphene-based capacitive pressure sensor is fabricated, where it shows a linear response and a high sensitivity of 15.15 aF Pa-1, which is 770% higher than that of frequently used silicon-based membranes. The reported approach is universal, which could be employed to fabricate other suspended 2D materials with macro-scale sizes on versatile support substrates, such as arrays of Si nano-pillars and deep trenches.In this work, we fabricate ultra-large suspended graphene membranes, where stacks of a few layers of graphene could be suspended over a circular hole with a diameter of up to 1.5 mm, with a diameter to thickness aspect ratio of 3 × 105, which is the record for free-standing graphene membranes. The process is based on large crystalline graphene (~55 μm) obtained using a chemical vapor deposition (CVD) method, followed by a gradual solvent replacement technique. Combining a hydrogen bubbling transfer approach with thermal annealing to reduce polymer residue results in an extremely clean surface, where the ultra-large suspended graphene retains the intrinsic features of graphene, including phonon response and an enhanced carrier mobility (200% higher than that of graphene on a substrate). The highly elastic mechanical properties of the graphene membrane are demonstrated, and the Q-factor under 2 MHz stimulation is measured to be 200-300. A graphene-based capacitive pressure sensor is fabricated, where it shows a linear response and a high sensitivity of 15.15 aF Pa-1, which is 770% higher than that of frequently used silicon-based membranes. The reported approach is universal, which could be employed to fabricate other suspended 2D materials with macro-scale sizes on versatile support substrates, such as arrays of Si nano-pillars and deep trenches. Electronic supplementary information (ESI) available: The detailed process/recipe for CVD-grown graphene and the transferring process, SEM and TEM images, contact angles, force curves, and movie clips. See DOI: 10.1039/c5nr08668j

Concentration variance decay during magma mixing: a volcanic chronometer

PubMed Central

Perugini, Diego; De Campos, Cristina P.; Petrelli, Maurizio; Dingwell, Donald B.

2015-01-01

The mixing of magmas is a common phenomenon in explosive eruptions. Concentration variance is a useful metric of this process and its decay (CVD) with time is an inevitable consequence during the progress of magma mixing. In order to calibrate this petrological/volcanological clock we have performed a time-series of high temperature experiments of magma mixing. The results of these experiments demonstrate that compositional variance decays exponentially with time. With this calibration the CVD rate (CVD-R) becomes a new geochronometer for the time lapse from initiation of mixing to eruption. The resultant novel technique is fully independent of the typically unknown advective history of mixing – a notorious uncertainty which plagues the application of many diffusional analyses of magmatic history. Using the calibrated CVD-R technique we have obtained mingling-to-eruption times for three explosive volcanic eruptions from Campi Flegrei (Italy) in the range of tens of minutes. These in turn imply ascent velocities of 5-8 meters per second. We anticipate the routine application of the CVD-R geochronometer to the eruptive products of active volcanoes in future in order to constrain typical “mixing to eruption” time lapses such that monitoring activities can be targeted at relevant timescales and signals during volcanic unrest. PMID:26387555

Ethical considerations in clinical research on herbal medicine for prevention of cardiovascular disease in the ageing.

PubMed

Koonrungsesomboon, Nut; Karbwang, Juntra

2016-10-15

Cardiovascular disease (CVD) in the ageing is a major public health problem worldwide. The nature of most CVD is subclinical with pathological processes that can span over years. Use of preventive measures could be an appropriate approach to prevailing over CVD in the ageing, and herbal medicine is one of the promising preventive approaches and is currently of interest among medical societies. In the evidence-based era, herbal medicine is, however, often underestimated and approached with skepticism, mainly due to the paucity of scientific evidence. Properly designed clinical trials on herbal medicine for prevention of CVD in a geriatric population are thus of importance and of clinical value. To review ethical issues and discuss considerations when such research is proposed. Four ethical issues, including the scientific validity of research, risk-benefit assessments, subject selection and vulnerability, and informed consent, are structured and extensively discussed in this article. Ethical core considerations of prevention research of CVD on herbal medicine involve particular attention on the scientific validity of research, risk-benefit assessments, subject selection and vulnerability, and informed consent. These issues and considerations are keys, although they must be adapted to an individual research setting in which a clinical study is proposed. Copyright © 2015 Elsevier GmbH. All rights reserved.

HDL and microRNA Therapeutics in Cardiovascular Disease

PubMed Central

Michell, Danielle L.; Vickers, Kasey C.

2016-01-01

microRNAs (miRNA) are small non-coding RNAs (sRNA) that post-transcriptionally regulate gene (mRNA) expression and are implicated in many biological processes and diseases. Many miRNAs have been reported to be altered in cardiovascular disease (CVD); both cellular and extracellular miRNA levels are affected by hypercholesterolemia and atherosclerosis. We and other groups have reported that lipoproteins transport miRNAs in circulation and these lipoprotein signatures are significantly altered in hypercholesterolemia and coronary artery disease (CAD). Extracellular miRNAs are a new class of potential biomarkers for CVD; however, they may also be new drug targets as high-density lipoproteins (HDL) transfer functional miRNAs to recipient cells in an endocrine-like form of intercellular communication that likely suppresses vascular inflammation. Recently, RNA-based drugs have emerged as the next frontier in drug therapy, and there are many miRNA inhibitors and mimics in clinical development. Here, we discuss specific miRNA drug targets and how their manipulation may impact CVD. We also address the potential for manipulating HDL-miRNA levels to treat CVD and the use of HDL as a delivery vehicle for RNA and chemical drugs. Finally, we outline the current and future challenges for HDL and miRNA-based therapeutics for the prevention and treatment of CVD. PMID:27595929

Evaluation of HDL-modulating interventions for cardiovascular risk reduction using a systems pharmacology approach[S

PubMed Central

Gadkar, Kapil; Lu, James; Sahasranaman, Srikumar; Davis, John; Mazer, Norman A.; Ramanujan, Saroja

2016-01-01

The recent failures of cholesteryl ester transport protein inhibitor drugs to decrease CVD risk, despite raising HDL cholesterol (HDL-C) levels, suggest that pharmacologic increases in HDL-C may not always reflect elevations in reverse cholesterol transport (RCT), the process by which HDL is believed to exert its beneficial effects. HDL-modulating therapies can affect HDL properties beyond total HDL-C, including particle numbers, size, and composition, and may contribute differently to RCT and CVD risk. The lack of validated easily measurable pharmacodynamic markers to link drug effects to RCT, and ultimately to CVD risk, complicates target and compound selection and evaluation. In this work, we use a systems pharmacology model to contextualize the roles of different HDL targets in cholesterol metabolism and provide quantitative links between HDL-related measurements and the associated changes in RCT rate to support target and compound evaluation in drug development. By quantifying the amount of cholesterol removed from the periphery over the short-term, our simulations show the potential for infused HDL to treat acute CVD. For the primary prevention of CVD, our analysis suggests that the induction of ApoA-I synthesis may be a more viable approach, due to the long-term increase in RCT rate. PMID:26522778

Evaluation of HDL-modulating interventions for cardiovascular risk reduction using a systems pharmacology approach.

PubMed

Gadkar, Kapil; Lu, James; Sahasranaman, Srikumar; Davis, John; Mazer, Norman A; Ramanujan, Saroja

2016-01-01

The recent failures of cholesteryl ester transport protein inhibitor drugs to decrease CVD risk, despite raising HDL cholesterol (HDL-C) levels, suggest that pharmacologic increases in HDL-C may not always reflect elevations in reverse cholesterol transport (RCT), the process by which HDL is believed to exert its beneficial effects. HDL-modulating therapies can affect HDL properties beyond total HDL-C, including particle numbers, size, and composition, and may contribute differently to RCT and CVD risk. The lack of validated easily measurable pharmacodynamic markers to link drug effects to RCT, and ultimately to CVD risk, complicates target and compound selection and evaluation. In this work, we use a systems pharmacology model to contextualize the roles of different HDL targets in cholesterol metabolism and provide quantitative links between HDL-related measurements and the associated changes in RCT rate to support target and compound evaluation in drug development. By quantifying the amount of cholesterol removed from the periphery over the short-term, our simulations show the potential for infused HDL to treat acute CVD. For the primary prevention of CVD, our analysis suggests that the induction of ApoA-I synthesis may be a more viable approach, due to the long-term increase in RCT rate. Copyright © 2016 by the American Society for Biochemistry and Molecular Biology, Inc.

Laser assisted processing; Proceedings of the Meeting, Hamburg, Federal Republic of Germany, Sept. 19, 20, 1988

NASA Astrophysics Data System (ADS)

Laude, Lucien D.; Rauscher, Gerhard

The use of lasers in industrial material processing is discussed in reviews and reports. Sections are devoted to high-precision laser machining, deposition methods, ablation and polymers, and synthesis and oxidation. Particular attention is given to laser cutting of steel sheets, laser micromachining of material surfaces, process control in laser soldering, laser-induced CVD of doped Si stripes on SOS and their characterization by piezoresistivity measurements, laser CVD of Pt spots on glass, laser deposition of GaAs, UV-laser photoablation of polymers, ArF excimer-laser ablation of HgCdTe semiconductor, pulsed laser synthesis of Ti silicides and nitrides, the kinetics of laser-assisted oxidation of metallic films, and excimer-laser-assisted etching of solids for microelectronics.

TaC-coated graphite prepared via a wet ceramic process: Application to CVD susceptors for epitaxial growth of wide-bandgap semiconductors

NASA Astrophysics Data System (ADS)

Nakamura, Daisuke; Kimura, Taishi; Narita, Tetsuo; Suzumura, Akitoshi; Kimoto, Tsunenobu; Nakashima, Kenji

2017-11-01

A novel sintered tantalum carbide coating (SinTaC) prepared via a wet ceramic process is proposed as an approach to reducing the production cost and improving the crystal quality of bulk-grown crystals and epitaxially grown films of wide-bandgap semiconductors. Here, we verify the applicability of the SinTaC components as susceptors for chemical vapor deposition (CVD)-SiC and metal-organic chemical vapor deposition (MOCVD)-GaN epitaxial growth in terms of impurity incorporation from the SinTaC layers and also clarify the surface-roughness controllability of SinTaC layers and its advantage in CVD applications. The residual impurity elements in the SinTaC layers were confirmed to not severely incorporate into the CVD-SiC and MOCVD-GaN epilayers grown using the SinTaC susceptors. The quality of the epilayers was also confirmed to be equivalent to that of epilayers grown using conventional susceptors. Furthermore, the surface roughness of the SinTaC components was controllable over a wide range of average roughness (0.4 ≤ Ra ≤ 5 μm) and maximum height roughness (3 ≤ Rz ≤ 36 μm) through simple additional surface treatment procedures, and the surface-roughened SinTaC susceptor fabricated using these procedures was predicted to effectively reduce thermal stress on epi-wafers. These results confirm that SinTaC susceptors are applicable to epitaxial growth processes and are advantageous over conventional susceptor materials for reducing the epi-cost and improving the quality of epi-wafers.

Giving Bigger Satellites a Boost

NASA Technical Reports Server (NTRS)

2000-01-01

Ultramet, Inc. has spurred a new process for producing rocket engine thrust chambers, through SBIR funding and the Glenn Research Center. High-temperature oxidation-resistant thruster materials are being produced in order to achieve high-temperature capability without sacrificing reliability. These thruster materials lead to an estimated three-percent improvement in propulsion system performance. To develop this material, Ultramet used a process called chemical vapor deposition (CVD). CVD involves heating precursors for metals, like iridium and rhenium, to temperatures at which they become gaseous. They are then deposited onto a mandrel, or spindle, layer-by-layer to produce high-density, highly resistant materials from the inside out.

Toxicological and epidemiological studies of cardiovascular effects of ambient air fine particulate matter (PM2.5) and its chemical components: coherence and public health implications.

PubMed

Lippmann, Morton

2014-04-01

Recent investigations on PM2.5 constituents' effects in community residents have substantially enhanced our knowledge on the impacts of specific components, especially the HEI-sponsored National Particle Toxicity Component (NPACT) studies at NYU and UW-LRRI that addressed the impact of long-term PM2.5 exposure on cardiovascular disease (CVD) effects. NYU's mouse inhalation studies at five sites showed substantial variations in aortic plaque progression by geographic region that was coherent with the regional variation in annual IHD mortality in the ACS-II cohort, with both the human and mouse responses being primarily attributable to the coal combustion source category. The UW regressions of associations of CVD events and mortality in the WHI cohort, and of CIMT and CAC progression in the MESA cohort, indicated that [Formula: see text] had stronger associations with CVD-related human responses than OC, EC, or Si. The LRRI's mice had CVD-related biomarker responses to [Formula: see text]. NYU also identified components most closely associated with daily hospital admissions (OC, EC, Cu from traffic and Ni and V from residual oil). For daily mortality, they were from coal combustion ([Formula: see text], Se, and As). While the recent NPACT research on PM2.5 components that affect CVD has clearly filled some major knowledge gaps, and helped to define remaining uncertainties, much more knowledge is needed on the effects in other organ systems if we are to identify and characterize the most effective and efficient means for reducing the still considerable adverse health impacts of ambient air PM. More comprehensive speciation data are needed for better definition of human responses.

Vitamin D and Cardiovascular Disease: Can Novel Measures of Vitamin D Status Improve Risk Prediction and Address the Vitamin D Racial Paradox?

PubMed

Kim, Samuel M; Lutsey, Pamela L; Michos, Erin D

2017-01-01

To provide a state-of-the-art update on some emerging measures of vitamin D status and discuss how assessment of these key vitamin D metabolites might improve prognostication of risk for cardiovascular disease (CVD) outcomes. Vitamin D deficiency is a highly prevalent condition and relatively easy to treat with supplementation and/or modest sunlight exposure. A substantial body of experimental and epidemiological evidence suggest that vitamin D deficiency is a risk factor for CVD. Most epidemiologic studies to date have focused on total 25-hydroxyvitamin D [25(OH)D] concentrations, which is the established marker of vitamin D stores. However, there is emerging evidence that other novel markers of vitamin D metabolism may better characterize 'true' vitamin D status. Some key novel measures include bioavailable 25(OH)D, free 25(OH)D, 1-25 dihydroxyvitamin D, 24,25-dihydroxyvitamin D3 [24,25(OH) 2 D3], and ratio of 24,25(OH) 2 D3 to 25(OH)D [the vitamin D metabolic ratio]. Utilization of these biomarkers may enhance understanding of the association between vitamin D and CVD risk, and may provide explanation for the observation that 25(OH)D is a stronger CVD risk factor in whites than blacks. Novel measures of vitamin D status could potentially change clinical practice regarding how patients are currently screened for vitamin D status and defined as vitamin D deficient or not. However, whether measuring any of these alternate markers of vitamin D status can provide further insight regarding CVD risk beyond the traditionally measured 25(OH)D concentrations is uncertain at this time. This is an area where further research is strongly needed.

Vitamin D and Cardiovascular Disease: Can Novel Measures of Vitamin D Status Improve Risk Prediction and Address the Vitamin D Racial Paradox?

PubMed Central

Kim, Samuel M.; Lutsey, Pamela L.; Michos, Erin D.

2017-01-01

Purpose of review To provide a state-of-the-art update on some emerging measures of vitamin D status and discuss how assessment of these key vitamin D metabolites might improve prognostication of risk for cardiovascular disease (CVD) outcomes. Recent findings Vitamin D deficiency is a highly prevalent condition and relatively easy to treat with supplementation and/or modest sunlight exposure. A substantial body of experimental and epidemiological evidence suggest that vitamin D deficiency is a risk factor for CVD. Most epidemiologic studies to date have focused on total 25-hydroxyvitamin D [25(OH)D] concentrations, which is the established marker of vitamin D stores. However, there is emerging evidence that other novel markers of vitamin D metabolism may better characterize ‘true’ vitamin D status. Some key novel measures include bioavailable 25(OH)D, free 25(OH)D, 1–25 dihydroxyvitamin D, 24,25-dihydroxyvitamin D3 [24,25(OH)2D3], and ratio of 24,25(OH)2D3 to 25(OH)D [the vitamin D metabolic ratio]. Utilization of these biomarkers may enhance understanding of the association between vitamin D and CVD risk, and may provide explanation for the observation that 25(OH)D is a stronger CVD risk factor in whites than blacks Summary Novel measures of vitamin D status could potentially change clinical practice regarding how patients are currently screened for vitamin D status and defined as vitamin D deficient or not. However, whether measuring any of these alternate markers of vitamin D status can provide further insight regarding CVD risk beyond the traditionally measured 25(OH)D concentrations is uncertain at this time. This is an area where further research is strongly needed. PMID:28261371

Effect of catalyst film thickness on carbon nanotube growth by selective area chemical vapor deposition

NASA Astrophysics Data System (ADS)

Wei, Y. Y.; Eres, Gyula; Merkulov, V. I.; Lowndes, D. H.

2001-03-01

The correlation between prepatterned catalyst film thickness and carbon nanotube (CNT) growth by selective area chemical vapor deposition (CVD) was studied using Fe and Ni as catalyst. To eliminate sample-to-sample variations and create a growth environment in which the film thickness is the sole variable, samples with continuously changing catalyst film thickness from 0 to 60 nm were fabricated by electron-gun evaporation. Using thermal CVD CNTs preferentially grow as a dense mat on the thin regions of the catalyst film. Moreover, beyond a certain critical film thickness no tubes were observed. The critical film thickness for CNT growth was found to increase with substrate temperature. There appears to be no strong correlation between the film thickness and the diameter of the tubes. In contrast, using plasma enhanced CVD with Ni as catalyst, vertically oriented CNTs grow in the entire range of catalyst film thickness. The diameter of these CNTs shows a strong correlation with the catalyst film thickness. The significance of these experimental trends is discussed within the framework of the diffusion model for CNT growth.

Loneliness, Social Isolation, and Cardiovascular Health.

PubMed

Xia, Ning; Li, Huige

2018-03-20

Social and demographic changes have led to an increased prevalence of loneliness and social isolation in modern society. Recent Advances: Population-based studies have demonstrated that both objective social isolation and the perception of social isolation (loneliness) are correlated with a higher risk of mortality and that both are clearly risk factors for cardiovascular disease (CVD). Lonely individuals have increased peripheral vascular resistance and elevated blood pressure. Socially isolated animals develop more atherosclerosis than those housed in groups. Molecular mechanisms responsible for the increased cardiovascular risk are poorly understood. In recent reports, loneliness and social stress were associated with activation of the hypothalamic-pituitary-adrenocortical axis and the sympathetic nervous system. Repeated and chronic social stress leads to glucocorticoid resistance, enhanced myelopoiesis, upregulated proinflammatory gene expression, and oxidative stress. However, the causal role of these mechanisms in the development of loneliness-associated CVD remains unclear. Elucidation of the molecular mechanisms of how CVD is induced by loneliness and social isolation requires additional studies. Understanding of the pathomechanisms is essential for the development of therapeutic strategies to prevent the detrimental effects of social stress on health. Antioxid. Redox Signal. 28, 837-851.

Chocolate--guilty pleasure or healthy supplement?

PubMed

Latham, Laura S; Hensen, Zeb K; Minor, Deborah S

2014-02-01

Dark chocolate and other cocoa products are popular in the population as a whole, but their overall health benefit remains controversial. Observations from the Kuna Indian population have shown an impressive cardiovascular health benefit from cocoa. For various reasons, this benefit has not been as robust as in other populations. Additionally, several mechanisms have been proposed that might confer cocoa's possible health benefit, but no consensus has been reached on cocoa's physiologic role in promoting cardiovascular health. Flavanols, as well as theobromine, may contribute to enhancements in endothelial function and subsequent improvements in various contributors to cardiovascular disease (CVD) including hypertension, platelet aggregation and adhesion, insulin resistance, and hypercholesterolemia. While the benefits of cocoa may be altered at the various stages of growth, development, and production, it appears that for many people "healthy" dark chocolate may, indeed, provide a pleasurable role in CVD risk reduction. The objectives of this review are to discuss the associations of cocoa with decreased blood pressure and improved CVD risk, to describe the possible mechanisms for these potential benefits, and to highlight considerations for the use of cocoa as a dietary supplement.

Use of centrifugal-gravity concentration for rejection of talc and recovery improvement in base-metal flotation

NASA Astrophysics Data System (ADS)

Klein, Bern; Altun, Naci Emre; Ghaffari, Hassan

2016-08-01

The possibility of using a centrifugal-gravity concentrator to reject Mg-bearing minerals and minimize metal losses in the flotation of base metals was evaluated. Sample characterization, batch scoping tests, pilot-scale tests, and regrind-flotation tests were conducted on a Ni flotation tailings stream. Batch tests revealed that the Mg grade decreased dramatically in the concentrate products. Pilot-scale testing of a continuous centrifugal concentrator (Knelson CVD6) on the flotation tailings revealed that a concentrate with a low mass yield, low Mg content, and high Ni upgrade ratio could be achieved. Under optimum conditions, a concentrate at 6.7% mass yield was obtained with 0.85% Ni grade at 12.9% Ni recovery and with a low Mg distribution (1.7%). Size partition curves demonstrated that the CVD also operated as a size classifier, enhancing the rejection of talc fines. Overall, the CVD was capable of rejecting Mg-bearing minerals. Moreover, an opportunity exists for the novel use of centrifugal-gravity concentration for scavenging flotation tailings and/or after comminution to minimize amount of Mg-bearing minerals reporting to flotation.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kozlovski, V. V.; Lebedev, A. A.; Bogdanova, E. V.

The model of conductivity compensation in SiC under irradiation with high-energy electrons is presented. The following processes are considered to cause a decrease in the free carrier concentration: (i) formation of deep traps by intrinsic point defects, Frenkel pairs produced by irradiation; (ii) 'deactivation' of the dopant via formation of neutral complexes including a dopant atom and a radiation-induced point defect; and (iii) formation of deep compensating traps via generation of charged complexes constituted by a dopant atom and a radiation-induced point defect. To determine the compensation mechanism, dose dependences of the deep compensation of moderately doped SiC (CVD) undermore » electron irradiation have been experimentally studied. It is demonstrated that, in contrast to n-FZ-Si, moderately doped SiC (CVD) exhibits linear dependences (with a strongly nonlinear dependence observed for Si). Therefore, the conductivity compensation in silicon carbide under electron irradiation occurs due to deep traps formed by primary radiation defects (vacancies and interstitial atoms) in the silicon and carbon sublattices. It is known that the compensation in silicon is due to the formation of secondary radiation defects that include a dopant atom. It is shown that, in contrast to n-SiC (CVD), primary defects in only the carbon sublattice of moderately doped p-SiC (CVD) cannot account for the compensation process. In p-SiC, either primary defects in the silicon sublattice or defects in both sublattices are responsible for the conductivity compensation.« less

Evaluation of community health screening participants' knowledge of cardiovascular risk factors.

PubMed

Mooney, Leslie A; Franks, Amy M

2009-01-01

To assess knowledge of cardiovascular disease (CVD) risk factors among a group of health screening participants and to compare knowledge between participants with high and low CVD risk. Cross-sectional pilot study. Jonesboro, AR, during June 2007. 121 adult volunteers participating in a community health screening. 34-item self-administered written questionnaire. Ability to identify CVD risk factors and healthy values for CVD risk factors and the differences in these abilities between participants with high and low CVD risk. Participants demonstrated good knowledge of traditional CVD risk factors such as high blood pressure, high cholesterol, lack of exercise, and overweight or obese status. Knowledge of other CVD risk factors and healthy values for major CVD risk factors was limited. Participants with high CVD risk were significantly more likely to correctly identify high triglycerides as a CVD risk factor and to identify healthy values for fasting blood glucose and total cholesterol compared with participants with low CVD risk. Overall, participants lacked knowledge of the risk factor status and healthy values for many CVD risk factors. Participants with high CVD risk may have better knowledge of some CVD risk factors than participants with low CVD risk. These findings highlight the need for more education to improve knowledge in both risk groups.

Initiated chemical vapor deposition polymers for high peak-power laser targets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baxamusa, Salmaan H.; Lepro, Xavier; Lee, Tom

2016-12-05

Here, we report two examples of initiated chemical vapor deposition (iCVD) polymers being developed for use in laser targets for high peak-power laser systems. First, we show that iCVD poly(divinylbenzene) is more photo-oxidatively stable than the plasma polymers currently used in laser targets. Thick layers (10–12 μm) of this highly crosslinked polymer can be deposited with near-zero intrinsic film stress. Second, we show that iCVD epoxy polymers can be crosslinked after deposition to form thin adhesive layers for assembling precision laser targets. The bondlines can be made as thin as ~ 1 μm, approximately a factor of 2 thinner thanmore » achievable using viscous resin-based adhesives. These bonds can withstand downstream coining and stamping processes.« less

Ultrahigh-mobility graphene devices from chemical vapor deposition on reusable copper

PubMed Central

Banszerus, Luca; Schmitz, Michael; Engels, Stephan; Dauber, Jan; Oellers, Martin; Haupt, Federica; Watanabe, Kenji; Taniguchi, Takashi; Beschoten, Bernd; Stampfer, Christoph

2015-01-01

Graphene research has prospered impressively in the past few years, and promising applications such as high-frequency transistors, magnetic field sensors, and flexible optoelectronics are just waiting for a scalable and cost-efficient fabrication technology to produce high-mobility graphene. Although significant progress has been made in chemical vapor deposition (CVD) and epitaxial growth of graphene, the carrier mobility obtained with these techniques is still significantly lower than what is achieved using exfoliated graphene. We show that the quality of CVD-grown graphene depends critically on the used transfer process, and we report on an advanced transfer technique that allows both reusing the copper substrate of the CVD growth and making devices with mobilities as high as 350,000 cm2 V–1 s–1, thus rivaling exfoliated graphene. PMID:26601221

Modelling elderly cardiac patients decision making using Cognitive Work Analysis: identifying requirements for patient decision aids.

PubMed

Dhukaram, Anandhi Vivekanandan; Baber, Chris

2015-06-01

Patients make various healthcare decisions on a daily basis. Such day-to-day decision making can have significant consequences on their own health, treatment, care, and costs. While decision aids (DAs) provide effective support in enhancing patient's decision making, to date there have been few studies examining patient's decision making process or exploring how the understanding of such decision processes can aid in extracting requirements for the design of DAs. This paper applies Cognitive Work Analysis (CWA) to analyse patient's decision making in order to inform requirements for supporting self-care decision making. This study uses focus groups to elicit information from elderly cardiovascular disease (CVD) patients concerning a range of decision situations they face on a daily basis. Specifically, the focus groups addressed issues related to the decision making of CVD in terms of medication compliance, pain, diet and exercise. The results of these focus groups are used to develop high level views using CWA. CWA framework decomposes the complex decision making problem to inform three approaches to DA design: one design based on high level requirements; one based on a normative model of decision-making for patients; and the third based on a range of heuristics that patients seem to use. CWA helps in extracting and synthesising decision making from different perspectives: decision processes, work organisation, patient competencies and strategies used in decision making. As decision making can be influenced by human behaviour like skills, rules and knowledge, it is argued that patients require support to different types of decision making. This paper also provides insights for designers in using CWA framework for the design of effective DAs to support patients in self-management. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Raman Excitation Profile of the G-band Enhancement in Twisted Bilayer Graphene

NASA Astrophysics Data System (ADS)

Eliel, G. S. N.; Ribeiro, H. B.; Sato, K.; Saito, R.; Lu, Chun-Chieh; Chiu, Po-Wen; Fantini, C.; Righi, A.; Pimenta, M. A.

2017-12-01

A resonant Raman study of twisted bilayer graphene (TBG) samples with different twisting angles using many different laser lines in the visible range is presented. The samples were fabricated by CVD technique and transferred to Si/SiO2 substrates. The Raman excitation profiles of the huge enhancement of the G-band intensity for a group of different TBG flakes were obtained experimentally, and the analysis of the profiles using a theoretical expression for the Raman intensities allowed us to obtain the energies of the van Hove singularities generated by the Moiré patterns and the lifetimes of the excited state of the Raman process. Our results exhibit a good agreement between experimental and calculated energies for van Hove singularities and show that the lifetime of photoexcited carrier does not depend significantly on the twisting angle in the range intermediate angles ( 𝜃 between 10∘ and 15∘). We observed that the width of the resonance window (Γ ≈ 250 meV) is much larger than the REP of the Raman modes of carbon nanotubes, which are also enhanced by resonances with van Hove singularities.

Parental Age of Onset of Cardiovascular Disease as a Predictor for Offspring Age of Onset of Cardiovascular Disease.

PubMed

Allport, Shannon Anjelica; Kikah, Ngum; Abu Saif, Nessim; Ekokobe, Fonkem; Atem, Folefac D

2016-01-01

The risk for cardiovascular disease (CVD) is higher for individuals with a first-degree relative who developed premature CVD (with a threshold at age 55 years for a male or 65 years for a female). However, little is known about the effect that each unit increase or decrease of maternal or paternal age of onset of CVD has on offspring age of onset of CVD. We hypothesized that there is an association between maternal and paternal age of onset of CVD and offspring age of onset of CVD. We used the Framingham Heart Study database and performed conditional imputation for CVD-censored parental age (i.e. parents that didn't experience onset of CVD) and Cox proportional regression analysis, with offspring's age of onset of CVD as the dependent variable and parental age of onset of CVD as the primary predictor. Modifiable risk factors in offspring, such as cigarette smoking, body mass index (BMI), diabetes mellitus, systolic blood pressure (SBP), high-density lipoprotein (HDL) level, and low-density lipoprotein (LDL) level, were controlled for. Separate analyses were performed for the association between maternal age of onset of CVD and offspring age of onset of CVD and the association between paternal age of onset of CVD and offspring age of onset of CVD. Parental age of onset of CVD was predictive of offspring age of onset of CVD for maternal age of onset of CVD (P < .0001; N = 1401) and for paternal age of onset of CVD (P = 0.0134; N = 1221). A negative estimate of the coefficient of interest signifies that late onset of cardiovascular events in parents is protective of onset of CVD in offspring. Cigarette smoking and HDL level were important associated confounders. Offspring age of onset of cardiovascular disease is significantly associated with both maternal and paternal age of onset CVD. The incorporation of the parameters, maternal or paternal age of onset of CVD, into risk estimate calculators may improve accuracy of identification of high-risk patients in clinical settings.

C-Ni-Pd and CNT-Ni-Pd film's molecular and crystalline structure investigations by FTIR spectroscopy and XRD diffraction

NASA Astrophysics Data System (ADS)

Stepińska, Izabela; Czerwosz, ElŻbieta; Diduszko, Ryszard; Kozłowski, Mirosław; Wronka, Halina

2017-08-01

In this work molecular and crystalline structure of new type of nanocomposite films were investigated. These films compose of CNT decorated with palladium nanograins. They were prepared on a base of C-Ni films modified in CVD process. C-Ni nanocomposite films were obtained by PVD process and their modification by CVD leads to a growth of CNT film. CNTs-Ni or C-Ni films were treated with additional PVD process with palladium. Nickel and palladium acetate and fulleren C60 are precursors of films in PVD process. FTIR spectroscopy was used to studied the molecular structure of film in every stage of preparation . The crystalline structure of these films was studied by X-ray diffraction. SEM (scanning electron microscopy) was applied to investigate film's surface topography.

Chemical vapor deposition on chabazite (CHA) zeolite membranes for effective post-combustion CO2 capture.

PubMed

Kim, Eunjoo; Lee, Taehee; Kim, Hyungmin; Jung, Won-Jin; Han, Doug-Young; Baik, Hionsuck; Choi, Nakwon; Choi, Jungkyu

2014-12-16

Chabazite (CHA) zeolites with a pore size of 0.37 × 0.42 nm(2) are expected to separate CO2 (0.33 nm) from larger N2 (0.364 nm) in postcombustion flue gases by recognizing their minute size differences. Furthermore, the hydrophobic siliceous constituent in CHA membranes can allow for maintaining the CO2/N2 separation performance in the presence of H2O in contrast with the CO2 affinity-based membranes. In an attempt to increase the molecular sieving ability, the pore mouth size of all silica CHA (Si-CHA) particles was reduced via the chemical vapor deposition (CVD) of a silica precursor (tetraethyl orthosilicate). Accordingly, an increase of the CVD treatment duration decreased the penetration rate of CO2 into the CVD-treated Si-CHA particles. Furthermore, the CVD process was applied to siliceous CHA membranes in order to improve their CO2/N2 separation performance. Compared to the intact CHA membranes, the CO2/N2 maximum separation factor (max SF) for CVD-treated CHA membranes was increased by ∼ 2 fold under dry conditions. More desirably, the CO2/N2 max SF was increased by ∼ 3 fold under wet conditions at ∼ 50 °C, a representative temperature of the flue gas stream. In fact, the presence of H2O in the feed disfavored the permeation of N2 more than that of CO2 through CVD-modified CHA membranes and thus, contributed to the increased CO2/N2 separation factor.

Trauma exposure and endothelial function among midlife women.

PubMed

Thurston, Rebecca C; Barinas-Mitchell, Emma; von Känel, Roland; Chang, Yuefang; Koenen, Karestan C; Matthews, Karen A

2018-04-01

Trauma is a potent exposure that can have implications for health. However, little research has considered whether trauma exposure is related to endothelial function, a key process in the pathophysiology of cardiovascular disease (CVD). We tested whether exposure to traumatic experiences was related to poorer endothelial function among midlife women, independent of CVD risk factors, demographic factors, psychosocial factors, or a history of childhood abuse. In all, 272 nonsmoking perimenopausal and postmenopausal women aged 40 to 60 years without clinical CVD completed the Brief Trauma Questionnaire, the Child Trauma Questionnaire, physical measures, a blood draw, and a brachial ultrasound for assessment of brachial artery flow-mediated dilation (FMD). Relations between trauma and FMD were tested in linear regression models controlling for baseline vessel diameter, demographics, depression/anxiety, CVD risk factors, health behaviors, and, additionally, a history of childhood abuse. Over 60% of the sample had at least one traumatic exposure, and 18% had three or more exposures. A greater number of traumatic exposures was associated with lower FMD, indicating poorer endothelial function in multivariable models (beta, β [standard error, SE] -1.05 [0.40], P = 0.01). Relations between trauma exposure and FMD were particularly pronounced for three or more trauma exposures (b [SE] -1.90 [0.71], P = 0.008, relative to no exposures, multivariable). A greater number of traumatic exposures were associated with poorer endothelial function. Relations were not explained by demographics, CVD risk factors, mood/anxiety, or a by history of childhood abuse. Women with greater exposure to trauma over life maybe at elevated CVD risk.

Development and evaluation of die materials for use in the growth of silicon ribbons by the inverted ribbon growth process, task 2. LSSA project

NASA Technical Reports Server (NTRS)

Duffy, M. T.; Berkman, S.; Moss, H. S.; Cullen, G. W.

1978-01-01

The results of emission spectroscopic analysis indicate that molten silicon can remain in contact with hot-pressed Si3N4 (99.2 percent theoretical density) for prolonged periods without attaining the impurity content level of the nitride. Although MgO was used as binder, Mg was not found present in the silicon sessile drop in quantities much above the level initially present in the silicon source material. Preliminary experiments with EFG-type dies coated with CVD Si3N4 or CVD SiOxNy indicate that capillary rise does not occur readily in these dies. The same was found to be true of hot-pressed and reaction-sintered Si3N4 obtained commercially. However, when dies were formed by depositing CVD layers on shaped silicon slabs, a column of molten silicon was maintained in each CVD die while being heated in contact with a crucible of molten silicon. Preliminary wetting of dies appears necessary for EFG growth. Several ribbon growth experiments were performed from V-shaped dies.

Mixed Convection Flow in Horizontal CVD Reactors

NASA Astrophysics Data System (ADS)

Chiu, Wilson K. S.; Richards, Cristy J.; Jaluria, Yogesh

1998-11-01

Increasing demands for high quality films and production rates are challenging current Chemical Vapor Deposition (CVD) technology. Since film quality and deposition rates are strongly dependent on gas flow and heat transfer (W.K.S. Chiu and Y. Jaluria, ASME HTD-Vol. 347, pp. 293-311, 1997.), process improvement is obtained through the study of mixed convection flow and temperature distribution in a CVD reactor. Experimental results are presented for a CVD chamber with a horizontal or inclined resistance heated susceptor. Vaporized glycol solution illuminated by a light sheet is used for flow visualization. Temperature measurements are obtained by inserting thermocouple probes into the gas stream or embedding probes into the reactor walls. Flow visualization and temperature measurements show predominantly two dimensional flow and temperature distributions along the streamwise direction under forced convection conditions. Natural convection dominates under large heating rates and low flow rates. Over the range of parameters studied, several distinct flow regimes, characterized by instability, separation, and turbulence, are evident. Different flow regimes alter the flow pattern and temperature distribution, and in consequence, significantly modify deposition rates and uniformity.

Surface modification of pitch-based spherical activated carbon by CVD of NH 3 to improve its adsorption to uric acid

NASA Astrophysics Data System (ADS)

Liu, Chaojun; Liang, Xiaoyi; Liu, Xiaojun; Wang, Qin; Zhan, Liang; Zhang, Rui; Qiao, Wenming; Ling, Licheng

2008-08-01

Surface chemistry of pitch-based spherical activated carbon (PSAC) was modified by chemical vapor deposition of NH 3 (NH 3-CVD) to improve the adsorption properties of uric acid. The texture and surface chemistry of PSAC were studied by N 2 adsorption, pH PZC (point of zero charge), acid-base titration and X-ray photoelectron spectroscopy (XPS). NH 3-CVD has a limited effect on carbon textural characteristics but it significantly changed the surface chemical properties, resulting in positive effects on uric acid adsorption. After modification by NH 3-CVD, large numbers of nitrogen-containing groups (especially valley-N and center-N) are introduced on the surface of PSAC, which is responsible for the increase of pH PZC, surface basicity and uric acid adsorption capacity. Pseudo-second-order kinetic model can be used to describe the dynamic adsorption of uric acid on PSAC, and the thermodynamic parameters show that the adsorption of uric acid on PSAC is spontaneous, endothermic and irreversible process in nature.

High performance Ω-gated Ge nanowire MOSFET with quasi-metallic source/drain contacts.

PubMed

Burchhart, T; Zeiner, C; Hyun, Y J; Lugstein, A; Hochleitner, G; Bertagnolli, E

2010-10-29

Ge nanowires (NWs) about 2 µm long and 35 nm in diameter are grown heteroepitaxially on Si(111) substrates in a hot wall low-pressure chemical vapor deposition (LP-CVD) system using Au as a catalyst and GeH(4) as precursor. Individual NWs are contacted to Cu pads via e-beam lithography, thermal evaporation and lift-off techniques. Self-aligned and atomically sharp quasi-metallic copper-germanide source/drain contacts are achieved by a thermal activated phase formation process. The Cu(3)Ge segments emerge from the Cu contact pads through axial diffusion of Cu which was controlled in situ by SEM, thus the active channel length of the MOSFET is adjusted without any restrictions from a lithographic process. Finally the conductivity of the channel is enhanced by Ga(+) implantation leading to a high performance Ω-gated Ge-NW MOSFET with saturation currents of a few microamperes.

Spray CVD for Making Solar-Cell Absorber Layers

NASA Technical Reports Server (NTRS)

Banger, Kulbinder K.; Harris, Jerry; Jin, Michael H.; Hepp, Aloysius

2007-01-01

Spray chemical vapor deposition (spray CVD) processes of a special type have been investigated for use in making CuInS2 absorber layers of thin-film solar photovoltaic cells from either of two subclasses of precursor compounds: [(PBu3) 2Cu(SEt)2In(SEt)2] or [(PPh3)2Cu(SEt)2 In(SEt)2]. The CuInS2 films produced in the experiments have been characterized by x-ray diffraction, scanning electron microscopy, energy-dispersive spectroscopy, and four-point-probe electrical tests.

Ultratough CVD single crystal diamond and three dimensional growth thereof

DOEpatents

Hemley, Russell J [Washington, DC; Mao, Ho-kwang [Washington, DC; Yan, Chih-shiue [Washington, DC

2009-09-29

The invention relates to a single-crystal diamond grown by microwave plasma chemical vapor deposition that has a toughness of at least about 30 MPa m.sup.1/2. The invention also relates to a method of producing a single-crystal diamond with a toughness of at least about 30 MPa m.sup.1/2. The invention further relates to a process for producing a single crystal CVD diamond in three dimensions on a single crystal diamond substrate.

Vascular Ageing and Exercise: Focus on Cellular Reparative Processes.

PubMed

Ross, Mark D; Malone, Eva; Florida-James, Geraint

2016-01-01

Ageing is associated with an increased risk of developing noncommunicable diseases (NCDs), such as diabetes and cardiovascular disease (CVD). The increased risk can be attributable to increased prolonged exposure to oxidative stress. Often, CVD is preceded by endothelial dysfunction, which carries with it a proatherothrombotic phenotype. Endothelial senescence and reduced production and release of nitric oxide (NO) are associated with "vascular ageing" and are often accompanied by a reduced ability for the body to repair vascular damage, termed "reendothelialization." Exercise has been repeatedly shown to confer protection against CVD and diabetes risk and incidence. Regular exercise promotes endothelial function and can prevent endothelial senescence, often through a reduction in oxidative stress. Recently, endothelial precursors, endothelial progenitor cells (EPC), have been shown to repair damaged endothelium, and reduced circulating number and/or function of these cells is associated with ageing. Exercise can modulate both number and function of these cells to promote endothelial homeostasis. In this review we look at the effects of advancing age on the endothelium and these endothelial precursors and how exercise appears to offset this "vascular ageing" process.

MOCVD of aluminium oxide films using aluminium β-diketonates as precursors

NASA Astrophysics Data System (ADS)

Devi, A.; Shivashankar, S. A.; Samuelson, A. G.

2002-06-01

Deposition of Al203 coatings by CVD is of importance because they are often used as abrading material in cemented carbide cutting tools. The conventionally used CVD process for Al203 involves the corrosive reactant AICl3. In this paper, we report on the thermal characterisation of the metalorganic precursors namely aluminium tris-tetramethyl-heptanedionate [ Al(thd)3] and aluminium tris-acetylacetonate [ Al(acac)3] and their application to the CVD of Al203 films. Crystalline A1203 films were deposited by MOCVD at low temperatures by the pyrolysis of Al(thd)3 and AI(acac)3. The films were deposited on a TiN-coated tungsten carbide (TiN/WC) and Si(100) substrates in the temperature range 500-1100 °C. The as-deposited films were characterised by x-ray diffraction, optical microscopy, scanning and transmission electron microscopy, Auger electron spectroscopy. The observed crystallinity of films grown at low temperatures, their microstructure, and composition may be interpreted in terms of a growth process that involves the melting of the metalorganic precursor on the hot growth surface.

Alternate electrode materials for the SP100 reactor

NASA Astrophysics Data System (ADS)

Randich, E.

1992-05-01

This work was performed in response to a request by the Astro-Space Division of the General Electric Co. to develop alternate electrodes materials for the electrodes of the PD2 modules to be used in the SP100 thermoelectric power conversion system. Initially, the project consisted of four tasks: (1) development of a ZrB2 (C) CVD coating on SiMo substrates; (2) development of a ZrB2 (C) CVD coating on SiGe substrates; (3) development of CVI W for porous graphite electrodes; and (4) technology transfer of pertinent developed processes. The project evolved initially into developing only ZrB2 coatings on SiGe and graphite substrates, and later into developing ZrB2 coatings only on graphite substrates. Several sizes of graphite and pyrolytic carbon-coated graphite substrates were coated with ZrB2 during the project. For budgetary reasons, the project was terminated after half the allotted time had passed. Apart from the production of coated specimens for evaluation, the major accomplishment of the project was the development of the CVD processing to produce the desired coatings.

LARGE—A Plasma Torch for Surface Chemistry Applications and CVD Processes—A Status Report

NASA Astrophysics Data System (ADS)

Zimmermann, Stephan; Theophile, Eckart; Landes, Klaus; Schein, Jochen

2008-12-01

The LARGE ( LONG ARG GENERATOR) is a new generation DC-plasma torch featuring an extended arc which is operated with a perpendicular gas flow to create a wide (up to 45 cm) plasma jet well suited for large area plasma processing. Using plasma diagnostic systems like high speed imaging, enthalpy probe, emission spectroscopy, and tomography, the LARGE produced plasma jet characteristics have been measured and sources of instability have been identified. With a simple model/simulation of the system LARGE III-150 and numerous experimental results, a new nozzle configuration and geometry (LARGE IV-150) has been designed, which produces a more homogenous plasma jet. These improvements enable the standard applications of the LARGE plasma torch (CVD coating process and surface activation process) to operate with higher efficiency.

Cardiovascular Disease Prevalence and Risk Factors of Persons with Mental Retardation

ERIC Educational Resources Information Center

Draheim, Christopher C.

2006-01-01

This paper reviews the recent literature on cardiovascular disease (CVD) prevalence, CVD-related mortality, physiological CVD risk factors, and behavioral CVD risk factors in adults with mental retardation (MR). The literature on the potential influences of modifiable behavioral CVD risk factors and the physiological CVD risk factors are also…

Vasomotor symptoms and cardiovascular events in postmenopausal women

PubMed Central

Szmuilowicz, Emily D.; Manson, JoAnn E.; Rossouw, Jacques E.; Howard, Barbara V.; Margolis, Karen L.; Greep, Nancy C.; Brzyski, Robert G.; Stefanick, Marcia L.; O'Sullivan, Mary Jo; Wu, Chunyuan; Allison, Matthew; Grobbee, Diederick E.; Johnson, Karen C.; Ockene, Judith K.; Rodriguez, Beatriz L.; Sarto, Gloria E.; Vitolins, Mara Z.; Seely, Ellen W.

2010-01-01

Objective Emerging evidence suggests that women with menopausal vasomotor symptoms (VMS) have increased cardiovascular disease (CVD) risk as measured by surrogate markers. We investigated the relationships between VMS and clinical CVD events and all-cause mortality in the Women's Health Initiative Observational Study (WHI-OS). Methods We compared the risk of incident CVD events and all-cause mortality between four groups of women (total N=60,027): (1) No VMS at menopause onset and no VMS at WHI-OS enrollment (no VMS [referent group]); (2) VMS at menopause onset, but not at WHI-OS enrollment (early VMS); (3) VMS at both menopause onset and WHI-OS enrollment (persistent VMS [early and late]); and (4) VMS at WHI-OS enrollment, but not at menopause onset (late VMS). Results For women with early VMS (N=24,753), compared to no VMS (N=18,799), hazard ratios (HRs) and 95% confidence intervals (CIs) in fully-adjusted models were: major CHD, 0.94 (0.84, 1.06); stroke, 0.83 (0.72, 0.96); total CVD, 0.89 (0.81, 0.97); and all-cause mortality, 0.92 (0.85, 0.99). For women with persistent VMS (N=15,084), there was no significant association with clinical events. For women with late VMS (N=1,391) compared to no VMS, HRs and 95% CIs were: major CHD, 1.32 (1.01, 1.71); stroke, 1.14 (0.82, 1.59); total CVD, 1.23 (1.00, 1.52); and all-cause mortality, 1.29 (1.08, 1.54). Conclusions Early VMS were not associated with increased CVD risk. Rather, early VMS were associated with decreased risk of stroke, total CVD events, and all-cause mortality. Late VMS were associated with increased CHD risk and all-cause mortality. The predictive value of VMS for clinical CVD events may vary with onset of VMS at different stages of menopause. Further research examining the mechanisms underlying these associations is needed. Future studies will also be necessary to investigate whether VMS that develop for the first time in the later postmenopausal years represent a pathophysiologic process distinct from classical perimenopausal VMS. PMID:21358352

Silicon carbide, a semiconductor for space power electronics

NASA Technical Reports Server (NTRS)

Powell, J. Anthony; Matus, Lawrence G.

1991-01-01

After many years of promise as a high temperature semiconductor, silicon carbide (SiC) is finally emerging as a useful electronic material. Recent significant progress that has led to this emergence has been in the areas of crystal growth and device fabrication technology. High quality single-crystal SiC wafers, up to 25 mm in diameter, can now be produced routinely from boules grown by a high temperature (2700 K) sublimation process. Device fabrication processes, including chemical vapor deposition (CVD), in situ doping during CVD, reactive ion etching, oxidation, metallization, etc. have been used to fabricate p-n junction diodes and MOSFETs. The diode was operated to 870 K and the MOSFET to 770 K.

Effects of etchants in the transfer of chemical vapor deposited graphene

NASA Astrophysics Data System (ADS)

Wang, M.; Yang, E. H.; Vajtai, R.; Kono, J.; Ajayan, P. M.

2018-05-01

The quality of graphene can be strongly modified during the transfer process following chemical vapor deposition (CVD) growth. Here, we transferred CVD-grown graphene from a copper foil to a SiO2/Si substrate using wet etching with four different etchants: HNO3, FeCl3, (NH4)2S2O8, and a commercial copper etchant. We then compared the quality of graphene after the transfer process in terms of surface modifications, pollutions (residues and contaminations), and electrical properties (mobility and density). Our tests and analyses showed that the commercial copper etchant provides the best structural integrity, the least amount of residues, and the smallest doping carrier concentration.

75 FR 74773 - Mandatory Reporting of Greenhouse Gases: Additional Sources of Fluorinated GHGs

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-01

..., Methods for Estimating Air Emissions from Chemical Manufacturing Facilities; Protocol for Equipment Leak... chemical vapor deposition process (CVD) or other manufacturing processes use N 2 O. Production processes.... N 2 O emissions from chemical vapor deposition and other electronics manufacturing processes...

Robofurnace: A semi-automated laboratory chemical vapor deposition system for high-throughput nanomaterial synthesis and process discovery

PubMed Central

Oliver, C. Ryan; Westrick, William; Koehler, Jeremy; Brieland-Shoultz, Anna; Anagnostopoulos-Politis, Ilias; Cruz-Gonzalez, Tizoc; Hart, A. John

2013-01-01

Laboratory research and development on new materials, such as nanostructured thin films, often utilizes manual equipment such as tube furnaces due to its relatively low cost and ease of setup. However, these systems can be prone to inconsistent outcomes due to variations in standard operating procedures and limitations in performance such as heating and cooling rates restrict the parameter space that can be explored. Perhaps more importantly, maximization of research throughput and the successful and efficient translation of materials processing knowledge to production-scale systems, relies on the attainment of consistent outcomes. In response to this need, we present a semi-automated lab-scale chemical vapor deposition (CVD) furnace system, called “Robofurnace.” Robofurnace is an automated CVD system built around a standard tube furnace, which automates sample insertion and removal and uses motion of the furnace to achieve rapid heating and cooling. The system has a 10-sample magazine and motorized transfer arm, which isolates the samples from the lab atmosphere and enables highly repeatable placement of the sample within the tube. The system is designed to enable continuous operation of the CVD reactor, with asynchronous loading/unloading of samples. To demonstrate its performance, Robofurnace is used to develop a rapid CVD recipe for carbon nanotube (CNT) forest growth, achieving a 10-fold improvement in CNT forest mass density compared to a benchmark recipe using a manual tube furnace. In the long run, multiple systems like Robofurnace may be linked to share data among laboratories by methods such as Twitter. Our hope is Robofurnace and like automation will enable machine learning to optimize and discover relationships in complex material synthesis processes. PMID:24289435

Impact of acute psychological stress on cardiovascular risk factors in face of insulin resistance.

PubMed

Jones, Kristian T; Shelton, Richard C; Wan, Jun; Li, Li

2016-11-01

Individuals with insulin resistance (IR) are at greater risk for cardiovascular disease (CVD). Psychological stress may contribute to develop CVD in IR, although mechanisms are poorly understood. Our aim was to test the hypothesis that individuals with IR have enhanced emotional and physiological responses to acute psychological stress, leading to increased CVD risk. Sixty participants were enrolled into the study, and classified into IR group (n = 31) and insulin sensitive group (n = 29) according to the Quantitative insulin sensitivity check index, which was calculated based on an oral glucose tolerance test. The Trier social stress test, a standardized experimental stress paradigm, was performed on each participant, and emotional and physiological responses were examined. Blood was collected from each subject for insulin, cytokines, and cortisol measurements. Compared with the insulin-sensitive group, individuals with IR had significantly lower ratings of energy and calm, but higher fatigue levels in response to acute stressors. Individuals with IR also showed blunted heart rate reactivity following stress. In addition, the IR status was worsened by acute psychological stress as demonstrated by further increased insulin secretion. Furthermore, individuals with IR showed significantly increased levels of leptin and interleukin-6, but decreased levels of adiponectin, at baseline, stress test, and post-stress period. Our findings in individuals with IR under acute stress would allow a better understanding of the risks for developing CVD and to tailor the interventions for better outcomes.

Effect of Pioglitazone on Cardio-Metabolic Risk in Patients with Obstructive Sleep Apnea

PubMed Central

Liu, Alice; Abbasi, Fahim; Kim, Sun H.; Ariel, Danit; Lamendola, Cindy; Cardell, James; Xu, Shiming; Patel, Shailja; Tomasso, Vanessa; Mojaddidi, Hafasa; Grove, Kaylene; Tsao, Philip S.; Kushida, Clete A.; Reaven, Gerald M.

2017-01-01

Prevalence of insulin resistance is increased in patients with obstructive sleep apnea (OSA). Since insulin resistance is an independent predictor of cardiovascular disease (CVD), this study was initiated to see if pioglitazone administration would improve insulin sensitivity, and thereby decrease risk of CVD in overweight/obese, nondiabetic, insulin-resistant patients with untreated OSA. Patients (n=30) were administered pioglitazone (45 mg/day) for 8 weeks, and measurements were made before and after intervention of insulin action (insulin-mediated glucose uptake by the insulin suppression test), C-reactive protein, lipid/lipoprotein profile, and gene expression profile of peri-umbilical subcutaneous fat tissue. Insulin sensitivity increased 31% (p<0.001) among pioglitazone-treated individuals, associated with a decrease in C-reactive protein concentration (p≤ 0.001), a decrease in plasma triglyceride and increase in high-density lipoprotein cholesterol concentrations (p≤ 0.001), accompanied by significant changes in apolipoprotein A1 and B concentrations and lipoprotein subclasses known to decrease CVD risk. In addition, subcutaneous adipose tissue gene expression profile showed a 1.6-fold (p<0.01) increase in GLUT4 expression, as well as decreased expression in 5 of 9 inflammatory genes (p<0.05). In conclusion, enhanced insulin sensitivity can significantly decrease multiple cardio-metabolic risk factors in patients with untreated OSA, consistent with the view that coexisting insulin resistance plays an important role in the association between OSA and increased risk of CVD. PMID:28219664

Impact of Acute Psychological Stress on Cardiovascular Risk Factors in Face of Insulin Resistance

PubMed Central

Jones, Kristian T.; Shelton, Richard C.; Wan, Jun; Li, Li

2016-01-01

Individuals with insulin resistance (IR) are at greater risk for cardiovascular disease (CVD). Psychological stress may contribute to develop CVD in IR although mechanisms are poorly understood. Our aim was to test the hypothesis that individuals with IR have enhanced emotional and physiological responses to acute psychological stress, leading to increased CVD risk. Sixty participants were enrolled into the study, and classified into IR group (n=31) and insulin sensitive group (n=29) according to the Quantitative insulin sensitivity check index, which was calculated based on an oral glucose tolerance test. The Trier social stress test, a standardized experimental stress paradigm, was performed on each participant, and emotional and physiological responses were examined. Blood was collected from each subject for insulin, cytokines and cortisol measurements. Compared with insulin sensitive group, individuals with IR had significantly lower ratings of energy and calm, but higher fatigue levels in response to acute stressors. Individuals with IR also showed blunted heart rate reactivity following stress. In addition, the IR status was worsened by acute psychological stress as demonstrated by further increased insulin secretion. Furthermore, individuals with IR showed significantly increased levels of leptin and interleukin-6, but decreased levels of adiponectin, at baseline, stress test and post-stress period. Our findings in individuals with IR under acute stress would allow a better understanding of the risks for developing CVD and to tailor the interventions for better outcomes. PMID:27588343

Anthocyanins in Cardiovascular Disease1

PubMed Central

Wallace, Taylor C.

2011-01-01

Anthocyanins are a group of abundant and widely consumed flavonoid constituents that occur ubiquitously in the plant kingdom, providing the bright red-orange to blue-violet colors present in many fruit- and vegetable-based food products. Their intake has been estimated to be up to 9-fold higher than that of other dietary flavonoids. Anthocyanins have become increasingly important to the food industry as their use as natural alternatives to artificial colors has become widespread and knowledge of their health-promoting properties has become more evident. Epidemiological studies suggest that increased consumption of anthocyanins lowers the risk of cardiovascular disease (CVD), the most common cause of mortality among men and women. Anthocyanins frequently interact with other phytochemicals, exhibiting synergistic biological effects but making contributions from individual components difficult to decipher. Over the past 2 decades, many peer-reviewed publications have demonstrated that in addition to their noted in vitro antioxidant activity, anthocyanins may regulate different signaling pathways involved in the development of CVD. This review summarizes the latest developments on the bioavailability/bioactivity and CVD preventative activities of anthocyanins, including results from in vitro cell culture and in vivo animal model systems as related to their multiple proposed mechanisms of action. Limited yet promising data from epidemiological studies and human clinical trials are also presented. Future studies aimed at enhancing the absorption of anthocyanins and characterizing their metabolic and/or breakdown products are necessary to ultimately evaluate their use for protection/prevention against the development of CVD. PMID:22211184

Prevention and Control Program for Cardiovascular Diseases in Turkish Population: PRE-CONTROL Study Group.

PubMed

Kozan, Ömer; Zoghi, Mehdi; Ergene, Oktay; Arıcı, Mustafa; Derici, Ülver; Bakaç, Göksel; Güllü, Sevim; Sain Güven, Gülay

2013-06-01

Cardiovascular disease (CVD) is the leading cause of death throughout the world. Despite its high prevalence, the atherosclerotic process can be slowed and its consequences markedly reduced by preventive measures. The lack of risk factor awareness is a major barrier. We aimed to assess total CV risk, determine the knowledge and awareness regarding CVD, and evaluate the effectiveness of education program in urban population of Turkey. A 24-item questionnaire was used to detect CV risk factors and the awareness of participants about CVD. The feedback data for the education program were collected by either questionnaires or individual interviews with participants. For comparison of total CVD risk in men and women in different age groups, a sample t test was used. The level of statistical significance was set at p < 0.05. The prevalence of hyperlipidemia was established to be 41.3%. Nearly one-quarter of the women and one-third of the men were smokers (p < 0.001). One-quarter of the responders had a history of hypertension (men: 21.5%, women: 18.6%), and one-tenth were diabetic. The high CV risk rate was more pronounced among men (p < 0.01) and those with low socioeconomic level (p < 0.01). Awareness regarding CV risk factors following the educational program increased from 6.6% to 12.7% for high blood pressure, from 3.9% to 9.2% for diabetes mellitus, and from 10.2% to 15.1% for elevated cholesterol levels. All the increases were statistically significant. The educational program significantly increased the awareness of CVD and risk factors. The prevalence of CV risk factors was higher in low socioeconomic level groups. The knowledge and awareness of the risk factors for CVD before the education program was very low in our study group. The awareness of CVD and risk factors significantly increased following our education programs. Copyright © 2013 World Heart Federation (Geneva). Published by Elsevier B.V. All rights reserved.

Exposure monitoring of graphene nanoplatelets manufacturing workplaces.

PubMed

Lee, Ji Hyun; Han, Jong Hun; Kim, Jae Hyun; Kim, Boowook; Bello, Dhimiter; Kim, Jin Kwon; Lee, Gun Ho; Sohn, Eun Kyung; Lee, Kyungmin; Ahn, Kangho; Faustman, Elaine M; Yu, Il Je

2016-01-01

Graphenes have emerged as a highly promising, two-dimensional engineered nanomaterial that can possibly substitute carbon nanotubes. They are being explored in numerous R&D and industrial applications in laboratories across the globe, leading to possible human and environmental exposures to them. Yet, there are no published data on graphene exposures in occupational settings and no readily available methods for their detection and quantitation exist. This study investigates for the first time the potential exposure of workers and research personnel to graphenes in two research facilities and evaluates the status of the control measures. One facility manufactures graphene using graphite exfoliation and chemical vapor deposition (CVD), while the other facility grows graphene on a copper plate using CVD, which is then transferred to a polyethylene terephthalate (PET) sheet. Graphene exposures and process emissions were investigated for three tasks - CVD growth, exfoliation, and transfer - using a multi-metric approach, which utilizes several direct reading instruments, integrated sampling, and chemical and morphological analysis. Real-time instruments included a dust monitor, condensation particle counter (CPC), nanoparticle surface area monitor, scanning mobility particle sizer, and an aethalometer. Morphologically, graphenes and other nanostructures released from the work process were investigated using a transmission electron microscope (TEM). Graphenes were quantified in airborne respirable samples as elemental carbon via thermo-optical analysis. The mass concentrations of total suspended particulate at Workplaces A and B were very low, and elemental carbon concentrations were mostly below the detection limit, indicating very low exposure to graphene or any other particles. The real-time monitoring, especially the aethalometer, showed a good response to the released black carbon, providing a signature of the graphene released during the opening of the CVD reactor at Workplace A. The TEM observation of the samples obtained from Workplaces A and B showed graphene-like structures and aggregated/agglomerated carbon structures. Taken together, the current findings on common scenarios (exfoliation, CVD growth, and transfer), while not inclusive of all graphene manufacturing processes, indicate very minimal graphene or particle exposure at facilities manufacturing graphenes with good manufacturing practices.

Chemical vapour deposition growth of carbon nanotube forests: kinetics, morphology, composition, and their mechanisms

NASA Astrophysics Data System (ADS)

Vinten, Phillip

This thesis analyzes the chemical vapour deposition (CVD) growth of vertically aligned carbon nanotube (CNT) forests in order to understand how CNT forests grow, why they stop growing, and how to control the properties of the synthesized CNTs. in situ kinetics data of the growth of CNT forests are gathered by in situ optical microscopy. The overall morphology of the forests and the characteristics of the individual CNTs in the forests are investigated using scanning electron microscopy and Raman spectroscopy. The in situ data show that forest growth and termination are activated processes (with activation energies on the order of 1 eV), suggesting a possible chemical origin. The activation energy changes at a critical temperature for ethanol CVD (approximately 870°C). These activation energies and critical temperature are also seen in the temperature dependence of several important characteristics of the CNTs, including the defect density as determined by Raman spectroscopy. This observation is seen across several CVD processes and suggests a mechanism of defect healing. The CNT diameter also depends on the growth temperature. In this thesis, a thermodynamic model is proposed. This model predicts a temperature and pressure dependence of the CNT diameter from the thermodynamics of the synthesis reaction and the effect of strain on the enthalpy of formation of CNTs. The forest morphology suggests significant interaction between the constituent CNTs. These interactions may play a role in termination. The morphology, in particular a microscale rippling feature that is capable of diffracting light, suggest a non-uniform growth rate across the forest. A gas phase diffusion model predicts a non-uniform distribution of the source gas. This gas phase diffusion is suggested as a possible explanation for the non-uniform growth rate. The gas phase diffusion is important because growth by acetylene CVD is found to be very efficient (approximately 30% of the acetylene is converted to CNTs). It is seen that multiple mechanisms are active during CNT growth. The results of this thesis provide insight into both the basic understanding of the microscopic processes involved in CVD growth and how to control the properties of the synthesized CNTs.

Geographic Variation in Morbidity and Mortality of Cerebrovascular Diseases in Korea during 2011-2015.

PubMed

Lee, Juyeon; Bahk, Jinwook; Kim, Ikhan; Kim, Yeon-Yong; Yun, Sung-Cheol; Kang, Hee-Yeon; Lee, Jeehye; Park, Jong Heon; Shin, Soon-Ae; Khang, Young-Ho

2018-03-01

Little is known about within-country variation in morbidity and mortality of cerebrovascular diseases (CVDs). Geographic differences in CVD morbidity and mortality have yet to be properly examined. This study examined geographic variation in morbidity and mortality of CVD, neighborhood factors for CVD morbidity and mortality, and the association between CVD morbidity and mortality across the 245 local districts in Korea during 2011-2015. District-level health care utilization and mortality data were obtained to estimate age-standardized CVD morbidity and mortality. The bivariate Pearson correlation was used to examine the linear relationship between district-level CVD morbidity and mortality Z-scores. Simple linear regression and multivariate analyses were conducted to investigate the associations of area characteristics with CVD morbidity, mortality, and discrepancies between morbidity and mortality. Substantial variation was found in CVD morbidity and mortality across the country, with 1074.9 excess CVD inpatients and 73.8 excess CVD deaths per 100,000 between the districts with the lowest and highest CVD morbidity and mortality, respectively. Higher rates of CVD admissions and deaths were clustered in the noncapital regions. A moderate geographic correlation between CVD morbidity and mortality was found (Pearson correlation coefficient = .62 for both genders). Neighborhood level indicators for socioeconomic disadvantages, undersupply of health care resources, and unhealthy behaviors were positively associated with CVD morbidity and mortality and the relative standing of CVD mortality vis-à-vis morbidity. Policy actions targeting life-course socioeconomic conditions, equitable distribution of health care resources, and behavioral risk factors may help reduce geographic differences in CVD morbidity and mortality in Korea. Copyright © 2018 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Vivir Con Un Corazón Saludable: a Community-Based Educational Program Aimed at Increasing Cardiovascular Health Knowledge in High-Risk Hispanic Women.

PubMed

Romero, Daniela C; Sauris, Aileen; Rodriguez, Fátima; Delgado, Daniela; Reddy, Ankita; Foody, JoAnne M

2016-03-01

Hispanic women suffer from high rates of cardiometabolic risk factors and an increasingly disproportionate burden of cardiovascular disease (CVD). Particularly, Hispanic women with limited English proficiency suffer from low levels of CVD knowledge associated with adverse CVD health outcomes. Thirty-two predominantly Spanish-speaking Hispanic women completed, Vivir Con un Corazón Saludable (VCUCS), a culturally tailored Spanish language-based 6-week intensive community program targeting CVD health knowledge through weekly interactive health sessions. A 30-question CVD knowledge questionnaire was used to assess mean changes in CVD knowledge at baseline and postintervention across five major knowledge domains including CVD epidemiology, dietary knowledge, medical information, risk factors, and heart attack symptoms. Completion of the program was associated with a statistically significant (p < 0.001) increase in total mean CVD knowledge scores from 39 % (mean 11.7/30.0) to 66 % (mean 19.8/30.0) postintervention consistent with a 68 % increase in overall mean CVD scores. There was a statistically significant (p < 0.001) increase in mean knowledge scores across all five CVD domains. A culturally tailored Spanish language-based health program is effective in increasing CVD awareness among high CVD risk Hispanic women with low English proficiency and low baseline CVD knowledge.

Dose-dependent consumption of farmed Atlantic salmon (salmo salar) increases plasma phospholipid n-3 fatty acids differentially

USDA-ARS?s Scientific Manuscript database

ABSTRACT Background: Enhanced n-3 intake benefit CVD risk reduction. Increasing consumption at a population level will be better addressed by dietary modification than through supplementation. However, limited data are available on the effect of increasing doses of fish intake on circulating level...

Exploiting Anti-T-shaped Graphene Architecture to Form Low Tortuosity, Sieve-like Interfaces for High-Performance Anodes for Li-Based Cells

PubMed Central

2017-01-01

Graphitic carbon anodes have long been used in Li ion batteries due to their combination of attractive properties, such as low cost, high gravimetric energy density, and good rate capability. However, one significant challenge is controlling, and optimizing, the nature and formation of the solid electrolyte interphase (SEI). Here it is demonstrated that carbon coating via chemical vapor deposition (CVD) facilitates high electrochemical performance of carbon anodes. We examine and characterize the substrate/vertical graphene interface (multilayer graphene nanowalls coated onto carbon paper via plasma enhanced CVD), revealing that these low-tortuosity and high-selection graphene nanowalls act as fast Li ion transport channels. Moreover, we determine that the hitherto neglected parallel layer acts as a protective surface at the interface, enhancing the anode performance. In summary, these findings not only clarify the synergistic role of the parallel functional interface when combined with vertical graphene nanowalls but also have facilitated the development of design principles for future high rate, high performance batteries. PMID:29392179

Patterns of Relationships between Cardiovascular Disease Risk Factors and Neurocognitive Function in African Americans

PubMed Central

Sims, Regina; Madhere, Serge; Callender, Clive; Campbell, Alfonso

2013-01-01

Objective The association between cardiovascular disease (CVD) risk and neurocognitive function has gathered a good deal of attention in the health and social science literature; however, the relationship among several CVD risk factors and neurocognitive function has not been fully explored in an African American sample. The purpose of this study was to examine the pattern of relationships among four CVD risk factors and five measures of higher cortical functions. Methods Data were collected from a sample of 106 African American community-dwelling adults in the metropolitan Washington, DC, area. A nurse collected blood pressure, waist circumference, and a blood sample (to assess triglycerides and high-density lipoprotein (HDL) cholesterol) from study participants. Participants completed the Symbol Digit Modalities Test, Trailmaking B, Stroop Colorword Task, California Verbal Learning Test-II, and Wisconsin Card Sorting Test as assessments of neurocognitive function. Canonical analysis and multiple regression analysis were the major statistical methods utilized to assess relationships between CVD risk factors and neurocognitive function. Results The results suggest that 1) attentional processes are associated with diastolic blood pressure levels, 2) verbal learning processes are associated with diastolic blood pressure and triglyceride levels, and 3) the ability to shift cognitive set is associated with HDL cholesterol levels. Conclusion As cardiovascular health worsens in our society, particularly among ethnic minorities, the neurocognitive consequences must be clearly understood. Future studies should focus on identifying and building awareness of cardiovascular and neurocognitive links through longitudinal research designs and brain imaging technology. PMID:19157252

Growth Mechanism of Transition Metal Dichalcogenide Monolayers: The Role of Self-Seeding Fullerene Nuclei.

PubMed

Cain, Jeffrey D; Shi, Fengyuan; Wu, Jinsong; Dravid, Vinayak P

2016-05-24

Due to their unique optoelectronic properties and potential for next generation devices, monolayer transition metal dichalcogenides (TMDs) have attracted a great deal of interest since the first observation of monolayer MoS2 a few years ago. While initially isolated in monolayer form by mechanical exfoliation, the field has evolved to more sophisticated methods capable of direct growth of large-area monolayer TMDs. Chemical vapor deposition (CVD) is the technique used most prominently throughout the literature and is based on the sulfurization of transition metal oxide precursors. CVD-grown monolayers exhibit excellent quality, and this process is widely used in studies ranging from the fundamental to the applied. However, little is known about the specifics of the nucleation and growth mechanisms occurring during the CVD process. In this study, we have investigated the nucleation centers or "seeds" from which monolayer TMDs typically grow. This was accomplished using aberration-corrected scanning transmission electron microscopy to analyze the structure and composition of the nuclei present in CVD-grown MoS2-MoSe2 alloys. We find that monolayer growth proceeds from nominally oxi-chalcogenide nanoparticles which act as heterogeneous nucleation sites for monolayer growth. The oxi-chalcogenide nanoparticles are typically encased in a fullerene-like shell made of the TMD. Using this information, we propose a step-by-step nucleation and growth mechanism for monolayer TMDs. Understanding this mechanism may pave the way for precise control over the synthesis of 2D materials, heterostructures, and related complexes.

Clinical Inertia in a Randomized Trial of Telemedicine-Based Chronic Disease Management: Lessons Learned.

PubMed

Barton, Anna Beth; Okorodudu, Daniel E; Bosworth, Hayden B; Crowley, Matthew J

2018-01-17

Treatment nonadherence and clinical inertia perpetuate poor cardiovascular disease (CVD) risk factor control. Telemedicine interventions may counter both treatment nonadherence and clinical inertia. We explored why a telemedicine intervention designed to reduce treatment nonadherence and clinical inertia did not improve CVD risk factor control, despite enhancing treatment adherence versus usual care. In this analysis of a randomized trial, we studied recipients of the 12-month telemedicine intervention. This intervention comprised two nurse-administered components: (1) monthly self-management education targeting improved treatment adherence; and (2) quarterly medication management facilitation designed to support treatment intensification by primary care (thereby reducing clinical inertia). For each medication management facilitation encounter, we ascertained whether patients met treatment goals, and if not, whether primary care recommended treatment intensification following the encounter. We assessed disease control associated with encounters, where intensification was/was not recommended. We examined 455 encounters across 182 intervention recipients (100% African Americans with type 2 diabetes). Even after accounting for valid reasons for deferring intensification (e.g., treatment nonadherence), intensification was not recommended in 67.5% of encounters in which hemoglobin A1c was above goal, 72.5% in which systolic blood pressure was above goal, and 73.9% in which low-density lipoprotein cholesterol was above goal. In each disease state, treatment intensification was more likely with poorer control. Despite enhancing treatment adherence, this intervention was unsuccessful in countering clinical inertia, likely explaining its lack of effect on CVD risk factors. We identify several lessons learned that may benefit investigators and healthcare systems.

Spatially Controlled Fabrication of Brightly Fluorescent Nanodiamond-Array with Enhanced Far-Red Si-V Luminescence

PubMed Central

Singh, Sonal; Thomas, Vinoy; Martyshkin, Dmitry; Kozlovskaya, Veronika; Kharlampieva, Eugenia

2014-01-01

We demonstrate a novel approach to precise pattern fluorescent nanodiamond-arrays with enhanced far-red intense photostable luminescence from silicon-vacancy (Si-V) defect centers. The precision-patterned pre-growth seeding of nanodiamonds is achieved by scanning probe “Dip-Pen” nanolithography technique using electrostatically-driven transfer of nanodiamonds from “inked” cantilevers to a UV-treated hydrophilic SiO2 substrate. The enhanced emission from nanodiamond-dots in the far-red is achieved by incorporating Si-V defect centers in subsequent chemical vapor deposition treatment. The development of a suitable nanodiamond ink, mechanism of ink transport, and effect of humidity, dwell time on nanodiamond patterning are investigated. The precision-patterning of as-printed (pre-CVD) arrays with dot diameter and dot height as small as 735 nm ± 27 nm, 61 nm ± 3 nm, respectively and CVD-treated fluorescent ND-arrays with consistently patterned dots having diameter and height as small as 820 nm ± 20 nm, 245 nm ± 23 nm, respectively using 1 s dwell time and 30% RH is successfully achieved. We anticipate that the far-red intense photostable luminescence (~738 nm) observed from Si-V defect centers integrated in spatially arranged nanodiamonds could be beneficial for the development of the next generation fluorescent based devices and applications. PMID:24394286

Preparation of LiMn{sub 2}O{sub 4} cathode thin films for thin film lithium secondary batteries by a mist CVD process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tadanaga, Kiyoharu, E-mail: tadanaga@chem.osakafu-u.ac.jp; Yamaguchi, Akihiro; Sakuda, Atsushi

2014-05-01

Highlights: • LiMn{sub 2}O{sub 4} thin films were prepared by using the mist CVD process. • An aqueous solution of lithium and manganese acetates is used for the precursor solution. • The cell with the LiMn{sub 2}O{sub 4} thin films exhibited a capacity of about 80 mAh/g. • The cell showed good cycling performance during 10 cycles. - Abstract: LiMn{sub 2}O{sub 4} cathode thin films for thin film lithium secondary batteries were prepared by using so-called the “mist CVD process”, employing an aqueous solution of lithium acetate and manganese acetate, as the source of Li and Mn, respectively. The aqueousmore » solution of starting materials was ultrasonically atomized to form mist particles, and mists were transferred by nitrogen gas to silica glass substrate to form thin films. FE-SEM observation revealed that thin films obtained by this process were dense and smooth, and thin films with a thickness of about 750 nm were obtained. The electrochemical cell with the thin films obtained by sintering at 700 °C exhibited a capacity of about 80 mAh/g, and the cell showed good cycling performance during 10 cycles.« less

Large scale atomistic simulation of single-layer graphene growth on Ni(111) surface: molecular dynamics simulation based on a new generation of carbon-metal potential

NASA Astrophysics Data System (ADS)

Xu, Ziwei; Yan, Tianying; Liu, Guiwu; Qiao, Guanjun; Ding, Feng

2015-12-01

To explore the mechanism of graphene chemical vapor deposition (CVD) growth on a catalyst surface, a molecular dynamics (MD) simulation of carbon atom self-assembly on a Ni(111) surface based on a well-designed empirical reactive bond order potential was performed. We simulated single layer graphene with recorded size (up to 300 atoms per super-cell) and reasonably good quality by MD trajectories up to 15 ns. Detailed processes of graphene CVD growth, such as carbon atom dissolution and precipitation, formation of carbon chains of various lengths, polygons and small graphene domains were observed during the initial process of the MD simulation. The atomistic processes of typical defect healing, such as the transformation from a pentagon into a hexagon and from a pentagon-heptagon pair (5|7) to two adjacent hexagons (6|6), were revealed as well. The study also showed that higher temperature and longer annealing time are essential to form high quality graphene layers, which is in agreement with experimental reports and previous theoretical results.To explore the mechanism of graphene chemical vapor deposition (CVD) growth on a catalyst surface, a molecular dynamics (MD) simulation of carbon atom self-assembly on a Ni(111) surface based on a well-designed empirical reactive bond order potential was performed. We simulated single layer graphene with recorded size (up to 300 atoms per super-cell) and reasonably good quality by MD trajectories up to 15 ns. Detailed processes of graphene CVD growth, such as carbon atom dissolution and precipitation, formation of carbon chains of various lengths, polygons and small graphene domains were observed during the initial process of the MD simulation. The atomistic processes of typical defect healing, such as the transformation from a pentagon into a hexagon and from a pentagon-heptagon pair (5|7) to two adjacent hexagons (6|6), were revealed as well. The study also showed that higher temperature and longer annealing time are essential to form high quality graphene layers, which is in agreement with experimental reports and previous theoretical results. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr06016h

Engineering Nanoscale Polymers in Photovoltaics and Supercapacitors: Experimental and Theoretical Studies

NASA Astrophysics Data System (ADS)

Smolin, Yuriy Y.

Dye sensitized solar cells (DSSCs) and carbon-based supercapacitors are promising energy conversion and storage systems, respectively, because they can be made inexpensively, have good performance, and can be integrated into portable and flexible electronics. Both systems utilize nanostructured porous electrodes, leading to fewer diffusion limitations and higher active surface areas for interfacial processes compared to planar electrodes. A major drawback of the DSSC design is the use of a liquid electrolyte, since it is prone to leakage and evaporation--hindering DSSC applications, durability, and thermal stability. A polymer electrolyte (PE) can overcome these shortcomings; however, the integration of a PE within the mesoporous TiO2 photoanode of DSSCs with pore openings of 10-20 nm and photoanode thicknesses of 10 microm is very challenging. Solution-based deposition methods such as spin coating and drop casting to deposit PEs has led to incomplete pore filling inside the mesoporous photoanode, resulting in lower than optimal efficiencies. To overcome these challenges, a solvent-free method called initiated chemical vapor deposition (iCVD) was adopted to deposit PEs within the porous TiO2 electrode. In iCVD, the monomer and initiator are vapors which easily penetrate into the porous electrode. By carefully controlling the iCVD processing parameters, complete pore filling of PEs into the TiO2 photoanode was achieved, leading to 50% improvement in conversion efficiency. Polymers with ether, ester, pyridine, pyrrolidone, imidazole and epoxy functionality were synthesized and integrated. The findings indicated that DSSC characteristics, including open circuit voltage, short circuit current density and fill factor, can be tuned by polymer chemistry. A promising approach to improve the energy density of supercapacitor electrodes is to integrate inexpensive conducting polymers (CPs), such as polyaniline (PANI). Unfortunately, most CPs are insoluble, and integrating CPs into tortuous electrode pores with aspect ratios of >10,000 while preserving the intrinsic pore structures, to retain the double layer capacitance, is very challenging. Therefore, similarly to the iCVD process, oxidative CVD (oCVD) was chosen to bypass the limited solubility of CPs to deposit thin conformal CP films onto porous electrodes. By controlling the oCVD deposition parameters, PANI films on the order of a few nm were integrated into carbide-derived-carbon (CDC) electrodes, leading to a doubling of the capacitance. This yielded a PANI-only capacitance of 690 F/g, close to the theoretical value of 750 F/g. This work also combined experiments with first-principles modeling to develop a model-guided design and optimization framework, allowing for optimal device design and the intelligent selection of polymer chemistries with minimal experimental investigations. For example, to determine the effects of PE chemistry on DSSC processes, parameter estimation and parametric sensitivity studies were conducted which indicated that a shift in the conduction band of TiO2 and a suppression of the back electron transfer at the dye-TiO2-PE interface was induced by the side group PE chemistry. Furthermore, optimal design specifications for a PE DSSC were calculated using the model, and optimally performing DSSCs were subsequently fabricated and tested, validating the model.

A Computational Chemistry Database for Semiconductor Processing

NASA Technical Reports Server (NTRS)

Jaffe, R.; Meyyappan, M.; Arnold, J. O. (Technical Monitor)

1998-01-01

The concept of 'virtual reactor' or 'virtual prototyping' has received much attention recently in the semiconductor industry. Commercial codes to simulate thermal CVD and plasma processes have become available to aid in equipment and process design efforts, The virtual prototyping effort would go nowhere if codes do not come with a reliable database of chemical and physical properties of gases involved in semiconductor processing. Commercial code vendors have no capabilities to generate such a database, rather leave the task to the user of finding whatever is needed. While individual investigations of interesting chemical systems continue at Universities, there has not been any large scale effort to create a database. In this presentation, we outline our efforts in this area. Our effort focuses on the following five areas: 1. Thermal CVD reaction mechanism and rate constants. 2. Thermochemical properties. 3. Transport properties.4. Electron-molecule collision cross sections. and 5. Gas-surface interactions.

Ultrasonic cavity preparation using CVD coated diamond bur: A case report

PubMed Central

de Vasconcellos, Beatriz Tholt; Thompson, Jeffrey Y.; de Paula Macedo, Manoel Roberto; de Oliveira Maia, Janaína Monalisa; Oda, Margareth; Garone-Netto, Narciso

2013-01-01

Before any restorative procedure can be undertaken a proper cavity preparation is required. This clinical step is the mechanical alteration of the tooth to receive a restorative material with which a satisfactory form, function and the esthetics of the tooth will be established. In recent years improvements in materials and techniques have been devised and new technologies are now available for this purpose. The aim of the present study is to report two clinical cases in which a CVD coated diamond bur coupled to an ultrasonic handpiece is used in dental preparation. This technique provides an accurate and conservative tooth preparation with ideal access and visibility and because of enhanced efficiency can also play a role in eliminating some of the patient discomfort of the dental treatment. PMID:23408140

Cardiovascular disease risk factors and the perception of general health among male law enforcement officers: encouraging behavioral change.

PubMed

Ramey, Sandra L

2003-05-01

The relationship among cardiovascular disease (CVD) morbidity, risk factors (including stress), and the perception of health among male law enforcement officers (LEOs) compared to men in the general population were examined in this study. Self reported prevalence of CVD and CVD risk factors among currently employed male LEOs from nine states (n = 2,818) were compared to those of other men in the same states (n = 9,650 for CVD risk factors, n = 3,147 for CVD prevalence). Perceived stress in LEOs was assessed to determine if it affected the relationship between CVD prevalence and CVD risk factors. Cross tabulated simple percentages showed CVD was less prevalent in the LEO group than among the general population. The best predictor variables for CVD were perceived stress, time in the profession, and hypertension. The LEO group had greater prevalence of hypercholesterolemia, overweight, and tobacco use than the general population. However, a greater percentage of LEOs perceived their health as "good to excellent" compared to men in the general population. Using multivariate analysis of variance (MANOVA) it was determined that perceived stress was associated with CVD in the LEO group and three CVD risk factors (i.e., cholesterol, hypertension, physical activity) were significantly affected by perceived stress. Among susceptible officers, stress may contribute to CVD development as well as potentiate several CVD risk factors. However, an apparent lack of association exists between perception of general health and CVD risk in LEOs.

Core-shell SrTiO3/graphene structure by chemical vapor deposition for enhanced photocatalytic performance

NASA Astrophysics Data System (ADS)

He, Chenye; Bu, Xiuming; Yang, Siwei; He, Peng; Ding, Guqiao; Xie, Xiaoming

2018-04-01

Direct growth of high quality graphene on the surface of SrTiO3 (STO) was realized through chemical vapor deposition (CVD), to construct few-layer 'graphene shell' on every STO nanoparticle. The STO/graphene composite shows significantly enhanced UV light photocatalytic activity compared with the STO/rGO reference. Mechanism analysis confirms the role of special core-shell structure and chemical bond (Tisbnd C) for rapid interfacial electron transfer and effective electron-hole separation.

Computational Modeling in Structural Materials Processing

NASA Technical Reports Server (NTRS)

Meyyappan, Meyya; Arnold, James O. (Technical Monitor)

1997-01-01

High temperature materials such as silicon carbide, a variety of nitrides, and ceramic matrix composites find use in aerospace, automotive, machine tool industries and in high speed civil transport applications. Chemical vapor deposition (CVD) is widely used in processing such structural materials. Variations of CVD include deposition on substrates, coating of fibers, inside cavities and on complex objects, and infiltration within preforms called chemical vapor infiltration (CVI). Our current knowledge of the process mechanisms, ability to optimize processes, and scale-up for large scale manufacturing is limited. In this regard, computational modeling of the processes is valuable since a validated model can be used as a design tool. The effort is similar to traditional chemically reacting flow modeling with emphasis on multicomponent diffusion, thermal diffusion, large sets of homogeneous reactions, and surface chemistry. In the case of CVI, models for pore infiltration are needed. In the present talk, examples of SiC nitride, and Boron deposition from the author's past work will be used to illustrate the utility of computational process modeling.

Evidence of Dietary Improvement and Preventable Costs of Cardiovascular Disease.

PubMed

Zhang, Donglan; Cogswell, Mary E; Wang, Guijing; Bowman, Barbara A

2017-11-01

We conducted a review to summarize preventable medical costs of cardiovascular disease (CVD) associated with improved diet, as defined by the 2020 Strategic Impact Goal of the American Heart Association. We searched databases of PubMed, Embase, CINAHL and ABI/INFORM to identify population-based studies published from January 1995 to December 2015 on CVD medical costs related to excess intake of salt/sodium or sugar-sweetened beverages, and inadequate intake of fruits and vegetables, fish/fish oils/omega-3 fatty acids, or whole grains/fiber/dietary fiber. Based on the American Heart Association's secondary dietary metrics, we also searched the literature on inadequate intake of nuts and excess intake of processed meat and saturated fat. For each component, we evaluated the CVD cost savings if consumption levels were changed. The cost savings were adjusted into 2013 US dollars. Among 330 studies focusing on diet and economic consequences, 16 studies evaluated CVD costs associated with 1 or more dietary components: salt/sodium (n = 13), fruits and vegetables (n = 1), meat (n = 1), and saturated fat (n = 3). In the United States, reducing individual sodium intake to 2,300 mg/day from the current level could potentially save $1,990.9/person per year for hypertension treatment, based on a simulation study. Increasing consumption of fruits and vegetables from <0.5 cup/day to >1.5 cups/day could save $1,568.0/person per year in treatment costs for CVD, based on a cohort study. Potential CVD cost savings associated with diet improvement are substantial. Interventions for reducing sodium intake and increasing fruit and vegetable consumption could be viable means to alleviate the increasing national medical expenditures. Published by Elsevier Inc.

Which hemostatic markers add to the predictive value of conventional risk factors for coronary heart disease and ischemic stroke? The Caerphilly Study.

PubMed

Smith, Ann; Patterson, Chris; Yarnell, John; Rumley, Ann; Ben-Shlomo, Yoav; Lowe, Gordon

2005-11-15

Few studies have examined whether hemostatic markers contribute to risk of coronary disease and ischemic stroke independently of conventional risk factors. This study examines 11 hemostatic markers that reflect different aspects of the coagulation process to determine which have prognostic value after accounting for conventional risk factors. A total of 2398 men aged 49 to 65 years were examined in 1984 to 1988, and the majority gave a fasting blood sample for assay of lipids and hemostatic markers. Men were followed up for a median of 13 years, and cardiovascular disease (CVD) events were recorded. There were 486 CVD events in total, 353 with prospective coronary disease and 133 with prospective ischemic stroke. On univariable analysis, fibrinogen, low activated protein C ratio, D-dimer, tissue plasminogen activator (tPA), and plasminogen activator inhibitor-1 (PAI-1) were associated significantly with risk of CVD. On multivariable analyses with conventional risk factors forced into the proportional hazards model, fibrinogen, D-dimer, and PAI-1 were significantly associated with risk of CVD, whereas factor VIIc showed an inverse association (P=0.001). In a model that contained the conventional risk factors, the hazard ratio for subsequent CVD in the top third of the distribution of predicted risk relative to the bottom third was 2.7 for subjects without preexisting CVD. This ratio increased to 3.7 for the model that also contained the 4 hemostatic factors. Fibrinogen, D-dimer, PAI-1 activity, and factor VIIc each has potential to increase the prediction of coronary disease/ischemic stroke in middle-aged men, in addition to conventional risk factors.

The role of non-invasive cardiovascular imaging in the assessment of cardiovascular risk in rheumatoid arthritis: where we are and where we need to be.

PubMed

Fent, Graham J; Greenwood, John P; Plein, Sven; Buch, Maya H

2017-07-01

This review assesses the risk assessment of cardiovascular disease (CVD) in rheumatoid arthritis (RA) and how non-invasive imaging modalities may improve risk stratification in future. RA is common and patients are at greater risk of CVD than the general population. Cardiovascular (CV) risk stratification is recommended in European guidelines for patients at high and very high CV risk in order to commence preventative therapy. Ideally, such an assessment should be carried out immediately after diagnosis and as part of ongoing long-term patient care in order to improve patient outcomes. The risk profile in RA is different from the general population and is not well estimated using conventional clinical CVD risk algorithms, particularly in patients estimated as intermediate CVD risk. Non-invasive imaging techniques may therefore play an important role in improving risk assessment. However, there are currently very limited prognostic data specific to patients with RA to guide clinicians in risk stratification using these imaging techniques. RA is associated with increased risk of CV mortality, mainly attributable to atherosclerotic disease, though in addition, RA is associated with many other disease processes which further contribute to increased CV mortality. There is reasonable evidence for using carotid ultrasound in patients estimated to be at intermediate risk of CV mortality using clinical CVD risk algorithms. Newer imaging techniques such as cardiovascular magnetic resonance and CT offer the potential to improve risk stratification further; however, longitudinal data with hard CVD outcomes are currently lacking. 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/.

The obesity paradox and incident cardiovascular disease: A population-based study.

PubMed

Chang, Virginia W; Langa, Kenneth M; Weir, David; Iwashyna, Theodore J

2017-01-01

Prior work suggests that obesity may confer a survival advantage among persons with cardiovascular disease (CVD). This obesity "paradox" is frequently studied in the context of prevalent disease, a stage in the disease process when confounding from illness-related weight loss and selective survival are especially problematic. Our objective was to examine the association of obesity with mortality among persons with incident CVD, where biases are potentially reduced, and to compare these findings with those based on prevalent disease. We used data from the Health and Retirement Study, an ongoing, nationally representative longitudinal survey of U.S. adults age 50 years and older initiated in 1992 and linked to Medicare claims. Cox proportional hazard models were used to estimate the association between weight status and mortality among persons with specific CVD diagnoses. CVD diagnoses were established by self-reported survey data as well as Medicare claims. Prevalent disease models used concurrent weight status, and incident disease models used pre-diagnosis weight status. We examined myocardial infarction, congestive heart failure, stroke, and ischemic heart disease. A strong and significant obesity paradox was consistently observed in prevalent disease models (hazard of death 18-36% lower for obese class I relative to normal weight), replicating prior findings. However, in incident disease models of the same conditions in the same dataset, there was no evidence of this survival benefit. Findings from models using survey- vs. claims-based diagnoses were largely consistent. We observed an obesity paradox in prevalent CVD, replicating prior findings in a population-based sample with longer-term follow-up. In incident CVD, however, we did not find evidence of a survival advantage for obesity. Our findings do not offer support for reevaluating clinical and public health guidelines in pursuit of a potential obesity paradox.

Risks of restrictive red blood cell transfusion strategies in patients with cardiovascular disease (CVD): a meta-analysis.

PubMed

Cortés-Puch, I; Wiley, B M; Sun, J; Klein, H G; Welsh, J; Danner, R L; Eichacker, P Q; Natanson, C

2018-04-19

To evaluate the risks of restrictive red blood cell transfusion strategies (haemoglobin 7-8 g dL -1 ) in patients with and without known cardiovascular disease (CVD). Recent guidelines recommend restrictive strategies for CVD patients hospitalised for non-CVD indications, patients without known CVD and patients hospitalised for CVD corrective procedures. Database searches were conducted through December 2017 for randomised clinical trials that enrolled patients with and without known CVD, hospitalised either for CVD-corrective procedures or non-cardiac indications, comparing effects of liberal with restrictive strategies on major adverse coronary events (MACE) and death. In CVD patients not undergoing cardiac interventions, a liberal strategy decreased (P = 0·01) the relative risk (95% CI) (RR) of MACE [0·50 (0·29-0·86)] (I 2  = 0%). Among patients without known CVD, the incidence of MACE was lower (1·7 vs 3·9%), and the effect of a liberal strategy on MACE [0·79, (0·39-1·58)] was smaller and non-significant but not different from CVD patients (P = 0·30). Combining all CVD and non-CVD patients, a liberal strategy decreased MACE [0·59, (0·39-0·91); P = 0·02]. Conversely, among studies reporting mortality, a liberal strategy decreased mortality in CVD patients (11·7% vs·13·3%) but increased mortality (19·2% vs 18·0%) in patients without known CVD [interaction P = 0·05; ratio of RR 0·73, (0·53-1·00)]. A liberal strategy also did not benefit patients undergoing cardiac surgery; data were insufficient for percutaneous cardiac procedures. In patients hospitalised for non-cardiac indications, liberal transfusion strategies are associated with a decreased risk of MACE in both those with and without known CVD. However, this only provides a survival benefit to CVD patients not admitted for CVD-corrective procedures. © 2018 British Blood Transfusion Society.

Chronic Kidney Disease as a Predictor of Cardiovascular Disease (From the Framingham Heart Study)

PubMed Central

Parikh, Nisha I.; Hwang, Shih-Jen; Larson, Martin G.; Levy, Daniel; Fox, Caroline S.

2008-01-01

Chronic kidney disease (CKD) is a risk factor for cardiovascular disease (CVD), although shared risk factors may mediate much of the association. We related CKD and CVD in the setting of specific CVD risk factors and determined whether more advanced CKD was a CVD risk equivalent. The Framingham Heart Study original cohort (n=2471, mean age 68 years, 58.9% women) was studied. Glomerular filtration rate (eGFR) was estimated using the simplified Modification of Diet in Renal Disease Study equation. CKD was defined as eGFR < 59 mL/min per 1.73 m2 (women) and < 64 (men) and Stage 3b CKD defined as eGFR 30-44 (women) and 30-50 (men). Cox Proportional Hazard models adjusting for CVD risk factors were used to relate CKD to CVD. We tested for effect modification by CVD risk factors. Overall, 23.2% of the study sample had CKD (n=574; mean eGFR 50 mL/min per 1.73 m2) and 5.3% had Stage 3b CKD (n=131; mean eGFR 42 mL/min per 1.73 m2). In multivariable models (mean follow-up time 16 years), Stage 3 CKD was marginally associated with CVD (HR=1.17, 95% CI 0.99-1.38, p=0.06), whereas Stage 3b CKD was associated with CVD [HR=1.41, 95% CI 1.05-1.91, p=0.02]. Upon testing CVD risk equivalency, the risk of CVD for Stage 3b CKD among participants with prior CVD was significantly lower as compared to participants with prior CVD and no Stage 3b CKD (age- and sex-adjusted HR for CVD = 0.66 [95% CI 0.47 to 0.91], p=0.01). Low HDL modified the association between CKD and CVD (p-value=0.004 for interaction). Stage 3b CKD is associated with CVD but is not a CVD risk equivalent. In conclusion, CVD risk in the setting of CKD is higher in the setting of low HDL cholesterol. PMID:18572034

Excellent Field Emission Properties of Short Conical Carbon Nanotubes Prepared by Microwave Plasma Enhanced CVD Process

PubMed Central

2008-01-01

Randomly oriented short and low density conical carbon nanotubes (CNTs) were prepared on Si substrates by tubular microwave plasma enhanced chemical vapor deposition process at relatively low temperature (350–550 °C) by judiciously controlling the microwave power and growth time in C2H2 + NH3gas composition and Fe catalyst. Both length as well as density of the CNTs increased with increasing microwave power. CNTs consisted of regular conical compartments stacked in such a way that their outer diameter remained constant. Majority of the nanotubes had a sharp conical tip (5–20 nm) while its other side was either open or had a cone/pear-shaped catalyst particle. The CNTs were highly crystalline and had many open edges on the outer surface, particularly near the joints of the two compartments. These films showed excellent field emission characteristics. The best emission was observed for a medium density film with the lowest turn-on and threshold fields of 1.0 and 2.10 V/μm, respectively. It is suggested that not only CNT tip but open edges on the body also act as active emission sites in the randomly oriented geometry of such periodic structures.

Adhesion scratch testing - A round-robin experiment

NASA Technical Reports Server (NTRS)

Perry, A. J.; Valli, J.; Steinmann, P. A.

1988-01-01

Six sets of samples, TiN coated by chemical or physical vapor deposition methods (CVD or PVD) onto cemented carbide or high-speed steel (HSS), and TiC coated by CVD onto cemented carbide have been scratch tested using three types of commercially available scratch adhesion tester. With exception of one cemented carbide set, the reproducibility of the critical loads for any given set with a given stylus is excellent, about + or - 5 percent, and is about + or - 20 percent for different styli. Any differences in critical loads recorded for any given sample set can be attributed to the condition of the stylus (clean, new, etc.), the instrument used, the stylus itself (friction coefficient, etc.), and the sample set itself. One CVD set showed remarkably large differences in critical loads for different styli, which is thought to be related to a mechanical interaction between stylus and coating which is enhanced by a plastic deformability in the film related to the coating microstructure. The critical load for TiN on HSS increases with coating thickness, and differences in frictional conditions led to a systematic variation in the critical loads depending on the stylus used.

Loneliness, Social Isolation, and Cardiovascular Health

PubMed Central

Xia, Ning

2018-01-01

Abstract Significance: Social and demographic changes have led to an increased prevalence of loneliness and social isolation in modern society. Recent Advances: Population-based studies have demonstrated that both objective social isolation and the perception of social isolation (loneliness) are correlated with a higher risk of mortality and that both are clearly risk factors for cardiovascular disease (CVD). Lonely individuals have increased peripheral vascular resistance and elevated blood pressure. Socially isolated animals develop more atherosclerosis than those housed in groups. Critical Issues: Molecular mechanisms responsible for the increased cardiovascular risk are poorly understood. In recent reports, loneliness and social stress were associated with activation of the hypothalamic–pituitary–adrenocortical axis and the sympathetic nervous system. Repeated and chronic social stress leads to glucocorticoid resistance, enhanced myelopoiesis, upregulated proinflammatory gene expression, and oxidative stress. However, the causal role of these mechanisms in the development of loneliness-associated CVD remains unclear. Future Directions: Elucidation of the molecular mechanisms of how CVD is induced by loneliness and social isolation requires additional studies. Understanding of the pathomechanisms is essential for the development of therapeutic strategies to prevent the detrimental effects of social stress on health. Antioxid. Redox Signal. 28, 837–851. PMID:28903579

Method and apparatus for removing and preventing window deposition during photochemical vapor deposition (photo-CVD) processes

DOEpatents

Tsuo, S.; Langford, A.A.

1989-03-28

Unwanted build-up of the film deposited on the transparent light-transmitting window of a photochemical vacuum deposition (photo-CVD) chamber is eliminated by flowing an etchant into the part of the photolysis region in the chamber immediately adjacent the window and remote from the substrate and from the process gas inlet. The respective flows of the etchant and the process gas are balanced to confine the etchant reaction to the part of the photolysis region proximate to the window and remote from the substrate. The etchant is preferably one that etches film deposit on the window, does not etch or affect the window itself, and does not produce reaction by-products that are deleterious to either the desired film deposited on the substrate or to the photolysis reaction adjacent the substrate. 3 figs.

Method and apparatus for removing and preventing window deposition during photochemical vapor deposition (photo-CVD) processes

DOEpatents

Tsuo, Simon; Langford, Alison A.

1989-01-01

Unwanted build-up of the film deposited on the transparent light-transmitting window of a photochemical vacuum deposition (photo-CVD) chamber is eliminated by flowing an etchant into the part of the photolysis region in the chamber immediately adjacent the window and remote from the substrate and from the process gas inlet. The respective flows of the etchant and the process gas are balanced to confine the etchant reaction to the part of the photolysis region proximate to the window and remote from the substrate. The etchant is preferably one that etches film deposit on the window, does not etch or affect the window itself, and does not produce reaction by-products that are deleterious to either the desired film deposited on the substrate or to the photolysis reaction adjacent the substrate.

An overview on tritium permeation barrier development for WCLL blanket concept

NASA Astrophysics Data System (ADS)

Aiello, A.; Ciampichetti, A.; Benamati, G.

2004-08-01

The reduction of tritium permeation through blanket structural materials and cooling tubes has to be carefully evaluated to minimise radiological hazards. A strong effort has been made in the past to select the best technological solution for the realisation of tritium permeation barriers (TPB) on complex structures not directly accessible after the completion of the manufacturing process. The best solution was identified in aluminium rich coatings, which form Al 2O 3 at their surface. Two technologies were selected as reference for the realisation of coating in the WCLL blanket concept: the chemical vapour deposition (CVD) process developed on laboratory scale by CEA, and the hot dipping (HD) process developed by FZK. The results obtained during three years of tests on CVD and HD coated specimens in gas and liquid metal phase are summarised and discussed.

Room temperature chemical vapor deposition of c-axis ZnO

NASA Astrophysics Data System (ADS)

Barnes, Teresa M.; Leaf, Jacquelyn; Fry, Cassandra; Wolden, Colin A.

2005-02-01

Highly (0 0 2) oriented ZnO films have been deposited at temperatures between 25 and 230 °C by high-vacuum plasma-assisted chemical vapor deposition (HVP-CVD) on glass and silicon substrates. The HVP-CVD process was found to be weakly activated with an apparent activation energy of ∼0.1 eV, allowing room temperature synthesis. Films deposited on both substrates displayed a preferential c-axis texture over the entire temperature range. Films grown on glass demonstrated high optical transparency throughout the visible and near infrared.

Dietary intake practices associated with cardiovascular risk in urban and rural Ecuadorian adolescents: a cross-sectional study.

PubMed

Ochoa-Avilés, Angélica; Verstraeten, Roosmarijn; Lachat, Carl; Andrade, Susana; Van Camp, John; Donoso, Silvana; Kolsteren, Patrick

2014-09-09

Cardiovascular diseases (CVD) are amongst the leading causes of death worldwide. Risk factors of CVD develop during childhood and adolescence, and dietary quality has been linked to the development of CVD itself. This study examines the association between dietary patterns and cardiovascular risk in a group of urban and rural Ecuadorian adolescents from different socioeconomic backgrounds. A cross-sectional study was conducted from January 2008 to April 2009 among 606 adolescents from the 8th, 9th and 10th grade in an urban area (Cuenca), and 173 adolescents from a rural area (Nabón) in Ecuador. Data collection involved measuring anthropometric data (weight, height and waist circumference), blood pressure, dietary intake (2-day 24 h recall) and socio-demographic characteristics. Fasting blood lipids and glucose were measured in a subsample of 334 adolescents. Factor analysis was used to identify dietary patterns and linear regression models were used to (i) identify differences in food intake practices according to socioeconomic status and place of residence and (ii) establish relationships between dietary patterns and cardiovascular risk factors. Median energy intake was 1851 kcal/day. Overall, fiber, fish and fruit and vegetables were scarcely consumed, while added sugar, refined cereals and processed food were important constituents of the diet. Two dietary patterns emerged, one labelled as "rice-rich non-animal fat pattern" and the other one as "wheat-dense animal-fat pattern". The first pattern was correlated with a moderate increase in glucose in urban participants, while the second pattern was associated with higher LDL and cholesterol blood levels in rural participants. This group of adolescents presented various dietary practices conducive to CVD development. Effective strategies are needed to prevent CVD in the Ecuadorian population by encouraging a balanced diet, which contains less refined cereals, added sugar, and processed food, but has more fruits, vegetables and whole grain cereals.

Hierarchical multifunctional composites by conformally coating aligned carbon nanotube arrays with conducting polymer.

PubMed

Vaddiraju, Sreeram; Cebeci, Hülya; Gleason, Karen K; Wardle, Brian L

2009-11-01

A novel method for the fabrication of carbon nanotube (CNT)-conducting polymer composites is demonstrated by conformally coating extremely high aspect ratio vertically aligned-CNT (A-CNT) arrays with conducting polymer via oxidative chemical vapor deposition (oCVD). A mechanical densification technique is employed that allows the spacing of the A-CNTs to be controlled, yielding a range of inter-CNT distances between 20 and 70 nm. Using this morphology control, oCVD is shown to conformally coat 8-nm-diameter CNTs having array heights up to 1 mm (an aspect ratio of 10(5)) at all inter-CNT spacings. Three phase CNT-conducting polymer nanocomposites are then fabricated by introducing an insulating epoxy via capillary-driven wetting. CNT morphology is maintained during processing, allowing quantification of direction-dependent (nonisotropic) composite properties. Electrical conductivity occurs primarily along the CNT axial direction, such that the conformal conducting polymer has little effect on the activation energy required for charge conduction. In contrast, the conducting polymer coating enhanced the conductivity in the radial direction by lowering the activation energy required for the creation of mobile charge carriers, in agreement with variable-range-hopping models. The fabrication strategy introduced here can be used to create many multifunctional materials and devices (e.g., direction-tailorable hydrophobic and highly conducting materials), including a new four-phase advanced fiber composite architecture.

A Community Health Advisor Program to reduce cardiovascular risk among rural African-American women

PubMed Central

Cornell, C. E.; Littleton, M. A.; Greene, P. G.; Pulley, L.; Brownstein, J. N.; Sanderson, B. K.; Stalker, V. G.; Matson-Koffman, D.; Struempler, B.; Raczynski, J. M.

2009-01-01

The Uniontown, Alabama Community Health Project trained and facilitated Community Health Advisors (CHAs) in conducting a theory-based intervention designed to reduce the risk for cardiovascular disease (CVD) among rural African-American women. The multiphased project included formative evaluation and community organization, CHA recruitment and training, community intervention and maintenance. Formative data collected to develop the training, intervention and evaluation methods and materials indicated the need for programs to increase knowledge, skills and resources for changing behaviors that increase the risk of CVD. CHAs worked in partnership with staff to develop, implement, evaluate and maintain strategies to reduce risk for CVD in women and to influence city officials, business owners and community coalitions to facilitate project activities. Process data documented sustained increases in social capital and community capacity to address health-related issues, as well as improvements in the community’s physical infrastructure. This project is unique in that it documents that a comprehensive CHA-based intervention for CVD can facilitate wide-reaching changes in capacity to address health issues in a rural community that include improvements in community infrastructure and are sustained beyond the scope of the originally funded intervention. PMID:19047648

Effect of irradiation with MeV protons and electrons on the conductivity compensation and photoluminescence of moderately doped p-4H-SiC (CVD)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kozlovski, V. V.; Lebedev, A. A., E-mail: shura.lebe@mail.ioffe.ru; Bogdanova, E. V.

The compensation of moderately doped p-4H-SiC samples grown by the chemical vapor deposition (CVD) method under irradiation with 0.9-MeV electrons and 15-MeV protons is studied. The experimentally measured carrier removal rates are 1.2–1.6 cm{sup –1} for electrons and 240–260 cm{sup –1} for protons. The dependence of the concentration of uncompensated acceptors and donors, measured in the study, demonstrates a linear decrease with increasing irradiation dose to the point of complete compensation. This run of the dependence shows that compensation of the samples is due to the transition of carriers to deep centers formed by primary radiation-induced defects. It is demonstratedmore » that, in contrast to n-SiC (CVD), primary defects in the carbon sublattice of moderately doped p-SiC (CVD) only cannot account for the compensation process. In p-SiC, either primary defects in the silicon sublattice, or defects in both sublattices are responsible for conductivity compensation. Also, photoluminescence spectra are examined in relation to the irradiation dose.« less

Chronic Inflammatory Diseases and Atherosclerotic Cardiovascular Disease: Innocent Bystanders or Partners in Crime?

PubMed

Hansen, Peter Riis

2018-01-01

Inflammation plays a significant role in atherosclerosis and cardiovascular disease (CVD). Patients with chronic inflammatory diseases are at increased risk of CVD, but it is debated whether this association is causal or dependent on shared risk factors, other exposures, genes, and/or inflammatory pathways. The current review summarizes epidemiological, clinical, and experimental data supporting the role of shared inflammatory mechanisms between atherosclerotic CVD and rheumatoid arthritis, psoriasis, inflammatory bowel disease, and periodontitis, respectively, and provides insights to future prospects in this area of research. Awareness of the role of inflammation in CVD in patients with chronic inflammatory diseases and the potential for anti-inflammatory therapy, e.g., with tumor necrosis factor-α inhibitors, to also reduce atherosclerotic CVD has evolved into guideline- based recommendations. These include regular CVD risk assessment, aggressive treatment of traditional CVD risk factors, and recognition of reduced CVD as an added benefit of strict inflammatory disease control. At present, chronic inflammatory diseases would appear to qualify as partners in crime and not merely innocent bystanders to CVD. However, definite incremental contributions of inflammation versus effects of the complex interplay with other CVD risk factors may never be fully elucidated and for the foreseeable future, inflammation is posed to maintain its current position as both a marker and a maker of CVD, with clinical utility both for identification of patient at risk of CVD and as target for therapy to reduce CVD. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Cardiovascular risk estimation by professionally active cardiovascular nurses: results from the Basel 2005 Nurses Cohort.

PubMed

Scholte op Reimer, Wilma J M; Moons, Philip; De Geest, Sabina; Fridlund, Bengt; Heikkilä, Johanna; Jaarsma, Tiny; Lenzen, Mattie; Martensson, Jan; Norekvål, Tone M; Smith, Karen; Stewart, Simon; Strömberg, Anna; Thompson, David R

2006-12-01

Nurses play a key role in the prevention of cardiovascular disease (CVD) and one would, therefore, expect them to have a heightened awareness of the need for systematic screening and their own CVD risk profile. The aim of this study was to examine personal awareness of CVD risk among a cohort of cardiovascular nurses attending a European conference. Of the 340 delegates attending the 5th annual Spring Meeting on Cardiovascular Nursing (Basel, Switzerland, 2005), 287 (83%) completed a self-report questionnaire to assess their own risk factors for CVD. Delegates were also asked to give an estimation of their absolute total risk of experiencing a fatal CVD event in the next 10 years. Level of agreement between self-reported CVD risk estimation and their actual risk according to the SCORE risk assessment system was compared by calculating weighted Kappa (kappa(w)). Overall, 109 responders (38%) self-reported having either pre-existing CVD (only 2%), one or more markedly raised CVD risk factors, a high total risk of fatal CVD (> or =5% in 10 years) or a strong family history of CVD. About half of this cohort (53%) did not know their own total cholesterol level. Less than half (45%) reported having a 10-year risk of fatal CVD of <1%, while 13% reported having a risk > or =5%. Based on the SCORE risk function, the estimated 10-year risk of a fatal CVD event was <1% for 96% of responders: only 2% had a > or =5% risk of such an event. Overall, less than half (46%) of this cohort's self-reported CVD risk corresponded with that calculated using the SCORE risk function (kappa(w)=0.27). Most cardiovascular nurses attending a European conference in 2005 poorly understood their own CVD risk profile, and the agreement between their self-reported 10-year risk of a fatal CVD and their CVD risk using SCORE was only fair. Given the specialist nature of this conference, our findings clearly demonstrate a need to improve overall nursing awareness of the role and importance of systematic CVD risk assessment.

Comparison of observed and modeled seasonal crustal vertical displacements derived from multi-institution GPS and GRACE solutions

NASA Astrophysics Data System (ADS)

Gu, Yanchao; Fan, Dongming; You, Wei

2017-07-01

Eleven GPS crustal vertical displacement (CVD) solutions for 110 IGS08/IGS14 core stations provided by the International Global Navigation Satellite Systems Service Analysis Centers are compared with seven Gravity Recovery and Climate Experiment (GRACE)-modeled CVD solutions. The results of the internal comparison of the GPS solutions from multiple institutions imply large uncertainty in the GPS postprocessing. There is also evidence that GRACE solutions from both different institutions and different processing approaches (mascon and traditional spherical harmonic coefficients) show similar results, suggesting that GRACE can provide CVD results of good internal consistency. When the uncertainty of the GPS data is accounted for, the GRACE data can explain as much as 50% of the actual signals and more than 80% of the GPS annual signals. Our study strongly indicates that GRACE data have great potential to correct the nontidal loading in GPS time series.

CVD-Enabled Graphene Manufacture and Technology

PubMed Central

2015-01-01

Integrated manufacturing is arguably the most challenging task in the development of technology based on graphene and other 2D materials, particularly with regard to the industrial demand for “electronic-grade” large-area films. In order to control the structure and properties of these materials at the monolayer level, their nucleation, growth and interfacing needs to be understood to a level of unprecedented detail compared to existing thin film or bulk materials. Chemical vapor deposition (CVD) has emerged as the most versatile and promising technique to develop graphene and 2D material films into industrial device materials and this Perspective outlines recent progress, trends, and emerging CVD processing pathways. A key focus is the emerging understanding of the underlying growth mechanisms, in particular on the role of the required catalytic growth substrate, which brings together the latest progress in the fields of heterogeneous catalysis and classic crystal/thin-film growth. PMID:26240694

Reducing flicker noise in chemical vapor deposition graphene field-effect transistors

NASA Astrophysics Data System (ADS)

Arnold, Heather N.; Sangwan, Vinod K.; Schmucker, Scott W.; Cress, Cory D.; Luck, Kyle A.; Friedman, Adam L.; Robinson, Jeremy T.; Marks, Tobin J.; Hersam, Mark C.

2016-02-01

Single-layer graphene derived from chemical vapor deposition (CVD) holds promise for scalable radio frequency (RF) electronic applications. However, prevalent low-frequency flicker noise (1/f noise) in CVD graphene field-effect transistors is often up-converted to higher frequencies, thus limiting RF device performance. Here, we achieve an order of magnitude reduction in 1/f noise in field-effect transistors based on CVD graphene transferred onto silicon oxide substrates by utilizing a processing protocol that avoids aqueous chemistry after graphene transfer. Correspondingly, the normalized noise spectral density (10-7-10-8 μm2 Hz-1) and noise amplitude (4 × 10-8-10-7) in these devices are comparable to those of exfoliated and suspended graphene. We attribute the reduction in 1/f noise to a decrease in the contribution of fluctuations in the scattering cross-sections of carriers arising from dynamic redistribution of interfacial disorder.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schulberg, M.T.; Allendorf, M.D.; Outka, D.A.

NH{sub 3} is an important component of many chemical vapor deposition (CVD) processes for TiN films, which are used for diffusion barriers and other applications in microelectronic circuits. In this study, the interaction of NH{sub 3} with TiN surfaces is examined with temperature programmed desorption (TPD) and Auger electron spectroscopy. NH{sub 3} has two adsorption states on TiN: a chemisorbed state and a multilayer state. A new method for analyzing TPD spectra in systems with slow pumping speeds yields activation energies for desorption for the two states of 24 kcal/mol and 7.3 kcal/mol, respectively. The sticking probability into the chemisorptionmore » state is {approximately}0.06. These results are discussed in the context of TiN CVD. In addition, the high temperature stability of TiN is investigated. TiN decomposes to its elements only after heating to 1300 K, showing that decomposition is unlikely to occur under CVD conditions.« less

Graphene growth with ‘no’ feedstock

NASA Astrophysics Data System (ADS)

Qing, Fangzhu; Jia, Ruitao; Li, Bao-Wen; Liu, Chunlin; Li, Congzhou; Peng, Bo; Deng, Longjiang; Zhang, Wanli; Li, Yanrong; Ruoff, Rodney S.; Li, Xuesong

2017-06-01

Synthesis of graphene by chemical vapor deposition (CVD) from hydrocarbons on Cu foil substrates can yield high quality and large area graphene films. In a typical CVD process, a hydrocarbon in the gas phase is introduced for graphene growth and hydrogen is usually required to achieve high quality graphene. We have found that in a low pressure CVD system equipped with an oil mechanical vacuum pump located downstream, graphene can be grown without deliberate introduction of a carbon feedstock but with only trace amounts of C present in the system, the origin of which we attribute to the vapor of the pump oil. This finding may help to rationalize the differences in graphene growth reported by different research groups. It should also help to gain an in-depth understanding of graphene growth mechanisms with the aim to improve the reproducibility and structure control in graphene synthesis, e.g. the formation of large area single crystal graphene and uniform bilayer graphene.

The optical properties of transferred graphene and the dielectrics grown on it obtained by ellipsometry

NASA Astrophysics Data System (ADS)

Kasikov, Aarne; Kahro, Tauno; Matisen, Leonard; Kodu, Margus; Tarre, Aivar; Seemen, Helina; Alles, Harry

2018-04-01

Graphene layers grown by chemical vapour deposition (CVD) method and transferred from Cu-foils to the oxidized Si-substrates were investigated by spectroscopic ellipsometry (SE), Raman and X-Ray Photoelectron Spectroscopy (XPS) methods. The optical properties of transferred CVD graphene layers do not always correspond to the ones of the exfoliated graphene due to the contamination from the chemicals used in the transfer process. However, the real thickness and the mean properties of the transferred CVD graphene layers can be found using ellipsometry if a real thickness of the SiO2 layer is taken into account. The pulsed laser deposition (PLD) and atomic layer deposition (ALD) methods were used to grow dielectric layers on the transferred graphene and the obtained structures were characterized using optical methods. The approach demonstrated in this work could be useful for the characterization of various materials grown on graphene.

Growth process of hydrogenated amorphous carbon films synthesized by atmospheric pressure plasma enhanced CVD using nitrogen and helium as a dilution gas

NASA Astrophysics Data System (ADS)

Mori, Takanori; Sakurai, Takachika; Sato, Taiki; Shirakura, Akira; Suzuki, Tetsuya

2016-04-01

Hydrogenated amorphous carbon films with various thicknesses were synthesized by dielectric barrier discharge-based plasma deposition under atmospheric pressure diluted with nitrogen (N2) and helium (He) at various pulse frequencies. The C2H2/N2 film showed cauliflower-like-particles that grew bigger with the increase in film’s thickness. At 5 kHz, the film with a thickness of 2.7 µm and smooth surface was synthesized. On the other hand, the films synthesized from C2H2/He had a smooth surface and was densely packed with domed particles. The domed particles extended with the increase in the film thickness, enabling it to grow successfully to 37 µm with a smooth surface.

Chemical vapor deposition of anisotropic ultrathin gold films on optical fibers: real-time sensing by tilted fiber Bragg gratings and use of a dielectric pre-coating

NASA Astrophysics Data System (ADS)

Mandia, David J.; Zhou, Wenjun; Ward, Matthew J.; Joress, Howie; Giorgi, Javier B.; Gordon, Peter; Albert, Jacques; Barry, Seán. T.

2014-09-01

Tilted fiber Bragg gratings (TFBGs) are refractometry-based sensor platforms that have been employed herein as devices for the real-time monitoring of chemical vapour deposition (CVD) in the near-infrared range (NIR). The coreguided light launched within the TFBG core is back-reflected off a gold mirror sputtered onto the fiber-end and is scattered out into the cladding where it can interact with a nucleating thin film. Evanescent fields of the growing gold nanostructures behave differently depending on the polarization state of the core-guided light interrogating the growing film, therefore the resulting spectral profile is typically decomposed into two separate peak families for the orthogonal S- and P-polarizations. Wavelength shifts and attenuation profiles generated from gold films in the thickness regime of 5-100 nm are typically degenerate for deposition directly onto the TFBG. However, a polarization-dependence can be imposed by adding a thin dielectric pre-coating onto the TFBG prior to using the device for CVD monitoring of the ultrathin gold films. It is found that addition of the pre-coating enhances the sensitivity of the P-polarized peak family to the deposition of ultrathin gold films and renders the films optically anisotropic. It is shown herein that addition of the metal oxide coating can increase the peak-to-peak wavelength separation between orthogonal polarization modes as well as allow for easy resonance tracking during deposition. This is also the first reporting of anisotropic gold films generated from this particular gold precursor and CVD process. Using an ensemble of x-ray techniques, the local fine structure of the gold films deposited directly on the TFBG is compared to gold films of similar thicknesses deposited on the Al2O3 pre-coated TFBG and witness slides.

Strain Gauges Based on CVD Graphene Layers and Exfoliated Graphene Nanoplatelets with Enhanced Reproducibility and Scalability for Large Quantities

PubMed Central

Yokaribas, Volkan; Schneider, Daniel S.; Friebertshäuser, Philipp; Lemme, Max C.; Fritzen, Claus-Peter

2017-01-01

The two-dimensional material graphene promises a broad variety of sensing activities. Based on its low weight and high versatility, the sensor density can significantly be increased on a structure, which can improve reliability and reduce fluctuation in damage detection strategies such as structural health monitoring (SHM). Moreover; it initializes the basis of structure–sensor fusion towards self-sensing structures. Strain gauges are extensively used sensors in scientific and industrial applications. In this work, sensing in small strain fields (from −0.1% up to 0.1%) with regard to structural dynamics of a mechanical structure is presented with sensitivities comparable to bulk materials by measuring the inherent piezoresistive effect of graphene grown by chemical vapor deposition (CVD) with a very high aspect ratio of approximately 4.86 × 108. It is demonstrated that the increasing number of graphene layers with CVD graphene plays a key role in reproducible strain gauge application since defects of individual layers may become less important in the current path. This may lead to a more stable response and, thus, resulting in a lower scattering.. Further results demonstrate the piezoresistive effect in a network consisting of liquid exfoliated graphene nanoplatelets (GNP), which result in even higher strain sensitivity and reproducibility. A model-assisted approach provides the main parameters to find an optimum of sensitivity and reproducibility of GNP films. The fabricated GNP strain gauges show a minimal deviation in PRE effect with a GF of approximately 5.6 and predict a linear electromechanical behaviour up to 1% strain. Spray deposition is used to develop a low-cost and scalable manufacturing process for GNP strain gauges. In this context, the challenge of reproducible and reliable manufacturing and operating must be overcome. The developed sensors exhibit strain gauges by considering the significant importance of reproducible sensor performances and open the path for graphene strain gauges for potential usages in science and industry. PMID:29258260

Telemonitoring can assist in managing cardiovascular disease in primary care: a systematic review of systematic reviews

PubMed Central

2014-01-01

Background There has been growing interest regarding the impact of telemonitoring and its ability to reduce the increasing burden of chronic diseases, including chronic cardiovascular disease (CVD), on healthcare systems. A number of randomised trials have been undertaken internationally and synthesised into various systematic reviews to establish an evidence base for this model of care. This study sought to synthesise and critically evaluate this large body of evidence to inform clinicians, researchers and policy makers. Methods A systematic review of systematic reviews investigating the impact of telemonitoring interventions in the primary care management of CVD was conducted. Reviews were included if they explored primary care based telemonitoring in either CVD, heart failure or hypertension, were reported in the English language and were published between 2000 and 2013. Data was extracted by one reviewer and checked by a second reviewer using a standardised form. Two assessors then rated the quality of each review using the Overview Quality Assessment Questionnaire (OQAQ). Results Of the 13 included reviews, four focused on telemonitoring interventions in hypertension or CVD management and the remaining 9 reviews investigated telemonitoring in HF management. Seven reviews scored a five or above on the OQAQ evidencing good quality reviews. Findings suggest that telemonitoring can contribute to significant reductions in blood pressure, decreased all-cause and HF related hospitalisations, reduced all-cause mortality and improved quality of life. Telemonitoring was also demonstrated to reduce health care costs and appears acceptable to patients. Conclusion Telemonitoring has the potential to enhance primary care management of CVD by improving patient outcomes and reducing health costs. However, further research needs to explore the specific elements of telemonitoring interventions to determine the relative value of the various elements. Additionally, the ways in which telemonitoring care improves health outcomes needs to be further explored to understand the nature of these interventions. PMID:24606887

Vascular or chronological age: which is the better marker to estimate the cardiovascular risk in patients with type 1 diabetes?

PubMed

de Andrade, Carlos Roberto Moraes; Silva, Eliete Leão Clemente; da Matta, Maria de Fátima Bevilaqua; Castier, Marcia Bueno; Rosa, Maria Luiza Garcia; Gomes, Marília Brito

2016-12-01

To evaluate whether using vascular age (VA) instead of chronological age (CA) in the Framingham score would enhance the cardiovascular disease (CVD) risk estimation in patients with type 1 diabetes (T1D). This was a cross-sectional study comprising 58 T1D patients and 38 control subjects matched by age, gender and body mass index. To estimate the VA, we used carotid intima-media thickness normality estimation tables that took into account age, gender and ethnic group. Compared to the control group, T1D patients had an older VA with an 8.8-year difference (p < 0.001), a higher CVD risk stratification comparing CA and VA (p < 0.001). In the group of T1D patients, there was a 9.4-year difference between VA and CA (p < 0.001), mainly due to a greater increase in women compared to men (11.2 vs 6.4 years, respectively) and 29.3 % of the patients with T1D increased their CVD risk stratification using VA as a parameter. Still, in the group of T1D patients, women had a higher increase in VA for each 1-year increase in CA than men (1.2 years vs 0.8 years, respectively, p < 0.001). This difference persisted as we compared women with T1D with women in the control group (0.4 years), p = 0.006. T1D patients have an increased VA, a marker of subclinical atherosclerosis. The use of VA age may contribute to the identification of high CVD risk in T1D. In patients with T1D, a younger chronological age, particularly in women, might not be a protective factor for CVD.

Contemporary Management and Control of Uncomplicated Hypertension in Canada: Insight From the Primary Care Audit of Global Risk Management (PARADIGM) Study.

PubMed

Gupta, Milan; Szmitko, Paul; Singh, Narendra; Tsigoulis, Michelle; Kajil, Mahesh; Stone, James

2015-05-01

Although clinical practice guidelines for the management of hypertension exist in Canada, the rate of contemporary blood pressure (BP) control remains unclear. In the Primary Care Audit of Global Risk Management (PARADIGM) study, 3015 healthy, middle-aged Canadians, free of cardiovascular disease (CVD) or diabetes were evaluated. In this analysis, we characterized the CVD risk factors, treatment patterns, and BP control rates in subjects with uncomplicated hypertension. A total of 917 subjects (30.4%) had a diagnosis of hypertension. The median age was 59 ± 8 years. The mean treated systolic/diastolic BP were 134 ± 14 mm Hg/82 ± 9 mm Hg, respectively. CVD risk factors included past/current smoking (35.9%), abdominal obesity (62.5%), and dyslipidemia (59.4%). Using the Framingham Risk Score, 20.4%, 41.0%, and 38.5% of the subjects were at low, intermediate, and high risk, respectively. Of the 88% with treated hypertension, 46.9%, 38.7%, and 14.3% received 1, 2, or ≥3 drugs, respectively. The rate of BP control was 57.4% (systolic BP < 140 and diastolic BP < 90 mm Hg). The rate of BP control was lower in patients prescribed diuretic monotherapy (53.2%) vs those who received angiotensin converting enzyme inhibitor/angiotensin receptor blocker monotherapy (66.5%; P < 0.01). Importantly, BP control deteriorated with increasing Framingham Risk Score, and was lower in patients with metabolic syndrome vs those without (P < 0.00001 for both). PARADIGM demonstrated that CVD risk factors are prevalent in Canadians with uncomplicated hypertension. BP control was modest (57.4%) and was lowest in patients prescribed diuretic monotherapy and in those at highest CVD risk. Despite the success of national hypertension strategies, enhanced efforts are warranted to improve BP control in Canada. Copyright © 2015 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

The APOA4 T347S variant is associated with reduced plasma TAOS in subjects with diabetes mellitus and cardiovascular disease.

PubMed

Wong, Wai-Man R; Stephens, Jeffrey W; Acharya, Jayshree; Hurel, Steven J; Humphries, Steve E; Talmud, Philippa J

2004-08-01

Apolipoprotein A-IV (apoA-IV) has been postulated to be antiatherogenic. Transgenic APOA4/Apoe-/- mice are protected against atherosclerosis, with plasma apoA-IV displaying antioxidant activity in vitro. In humans, there is an inverse relationship between apoA-IV levels and risk of coronary heart disease (CHD). Furthermore, the APOA4 T347S rare allele has been associated with increased risk of CHD and reduced apoA-IV levels. Reduced total antioxidant status (TAOS) due to increased oxidative stress is implicated in the process of atherogenesis. Thus, this study aimed to examine the association between the APOA4 T347S variant and TAOS in diabetic patients with (n = 196) or without (n = 509) cardiovascular disease (CVD). A higher percentage of CVD patients were present in the lowest quartile of TAOS, compared with the rest (P = 0.04). Overall, there was no association between genotype and TAOS. However, in patients with CVD, homozygotes for the S347 allele had significantly lower TAOS compared with TT and TS subjects (31.2 +/- 9.89% and 42.5 +/- 13.04% TAOS, respectively; P = 0.0024), an effect that was not seen in the patients without CVD. This study offers direct support for an antioxidant capacity of apoA-IV, thus providing some explanation for the antiatherogenic role of apoA-IV and the higher CVD risk in S347 homozygotes. Copyright 2004 American Society for Biochemistry and Molecular Biology, Inc.

Cardiovascular disease incidence in adolescent and young adult cancer survivors: a retrospective cohort study.

PubMed

Keegan, Theresa H M; Kushi, Lawrence H; Li, Qian; Brunson, Ann; Chawla, X; Chew, Helen K; Malogolowkin, Marcio; Wun, Ted

2018-06-01

Few population-based studies have focused on cardiovascular disease (CVD) risk in adolescent and young adult (AYA; 15-39 years) cancer survivors and none have considered whether CVD risk differs by sociodemographic factors. Analyses focused on 79,176 AYA patients diagnosed with 14 first primary cancers in 1996-2012 and surviving > 2 years after diagnosis with follow-up through 2014. Data were obtained from the California Cancer Registry and State hospital discharge data. CVD included coronary artery disease, heart failure, and stroke. The cumulative incidence of developing CVD accounted for the competing risk of death. Multivariable Cox proportional hazards regression evaluated factors associated with CVD and the impact of CVD on mortality. Overall, 2249 (2.8%) patients developed CVD. Survivors of central nervous system cancer (7.3%), acute lymphoid leukemia (6.9%), acute myeloid leukemia (6.8%), and non-Hodgkin lymphoma (4.1%) had the highest 10-year CVD incidence. In multivariable models, African-Americans (hazard ratio (HR) = 1.55, 95% confidence interval (CI) = 1.33-1.81; versus non-Hispanic Whites), those with public/no health insurance (HR = 1.78, 95% CI = 1.61-1.96; versus private) and those who resided in lower socioeconomic status neighborhoods had a higher CVD risk. These sociodemographic differences in CVD incidence were apparent across most cancer sites. The risk of death was increased by eightfold or higher among AYAs who developed CVD. While cancer therapies are known to increase the risk of CVD, this study additionally shows that CVD risk varies by sociodemographic factors. The identification and mitigation of CVD risk factors in these subgroups may improve long-term patient outcomes.

Dietary Choline and Betaine and Risk of CVD: A Systematic Review and Meta-Analysis of Prospective Studies

PubMed Central

Meyer, Katie A.; Shea, Jonathan W.

2017-01-01

Studies implicate choline and betaine metabolite trimethylamine N-oxide (TMAO) in cardiovascular disease (CVD). We conducted a systematic review and random-effects meta-analysis to quantify a summary estimated effect of dietary choline and betaine on hard CVD outcomes (incidence and mortality). Eligible studies were prospective studies in adults with comprehensive diet assessment and follow-up for hard CVD endpoints. We identified six studies that met our criteria, comprising 18,076 incident CVD events, 5343 CVD deaths, and 184,010 total participants. In random effects meta-analysis, incident CVD was not associated with choline (relative risk (RR): 1.00; 95% CI: 0.98, 1.02) or betaine (RR: 0.99; 95% CI: 0.98, 1.01) intake. Results did not vary by study outcome (incident coronary heart disease, stroke, total CVD) and there was no evidence for heterogeneity among studies. Only two studies provided data on phosphatidylcholine and CVD mortality. Random effects meta-analysis did not support an association between choline and CVD mortality (RR: 1.09, 95% CI: 0.89, 1.35), but one study supported a positive association and there was significant heterogeneity (I2 = 84%, p-value < 0.001). Our findings do not support an association between dietary choline/betaine with incident CVD, but call for further research into choline and CVD mortality. PMID:28686188

Dietary Choline and Betaine and Risk of CVD: A Systematic Review and Meta-Analysis of Prospective Studies.

PubMed

Meyer, Katie A; Shea, Jonathan W

2017-07-07

Studies implicate choline and betaine metabolite trimethylamine N-oxide (TMAO) in cardiovascular disease (CVD). We conducted a systematic review and random-effects meta-analysis to quantify a summary estimated effect of dietary choline and betaine on hard CVD outcomes (incidence and mortality). Eligible studies were prospective studies in adults with comprehensive diet assessment and follow-up for hard CVD endpoints. We identified six studies that met our criteria, comprising 18,076 incident CVD events, 5343 CVD deaths, and 184,010 total participants. In random effects meta-analysis, incident CVD was not associated with choline (relative risk (RR): 1.00; 95% CI: 0.98, 1.02) or betaine (RR: 0.99; 95% CI: 0.98, 1.01) intake. Results did not vary by study outcome (incident coronary heart disease, stroke, total CVD) and there was no evidence for heterogeneity among studies. Only two studies provided data on phosphatidylcholine and CVD mortality. Random effects meta-analysis did not support an association between choline and CVD mortality (RR: 1.09, 95% CI: 0.89, 1.35), but one study supported a positive association and there was significant heterogeneity ( I ² = 84%, p -value < 0.001). Our findings do not support an association between dietary choline/betaine with incident CVD, but call for further research into choline and CVD mortality.

Growth-substrate induced performance degradation in chemically synthesized monolayer MoS{sub 2} field effect transistors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Amani, Matin; Chin, Matthew L.; Mazzoni, Alexander L.

2014-05-19

We report on the electronic transport properties of single-layer thick chemical vapor deposition (CVD) grown molybdenum disulfide (MoS{sub 2}) field-effect transistors (FETs) on Si/SiO{sub 2} substrates. MoS{sub 2} has been extensively investigated for the past two years as a potential semiconductor analogue to graphene. To date, MoS{sub 2} samples prepared via mechanical exfoliation have demonstrated field-effect mobility values which are significantly higher than that of CVD-grown MoS{sub 2}. In this study, we will show that the intrinsic electronic performance of CVD-grown MoS{sub 2} is equal or superior to that of exfoliated material and has been possibly masked by a combinationmore » of interfacial contamination on the growth substrate and residual tensile strain resulting from the high-temperature growth process. We are able to quantify this strain in the as-grown material using pre- and post-transfer metrology and microscopy of the same crystals. Moreover, temperature-dependent electrical measurements made on as-grown and transferred MoS{sub 2} devices following an identical fabrication process demonstrate the improvement in field-effect mobility.« less

Nonaligned carbon nanotubes anchored on porous alumina: formation, process modeling, gas-phase analysis, and field-emission properties.

PubMed

Lysenkov, Dmitry; Engstler, Jörg; Dangwal, Arti; Popp, Alexander; Müller, Günter; Schneider, Jörg J; Janardhanan, Vinod M; Deutschmann, Olaf; Strauch, Peter; Ebert, Volker; Wolfrum, Jürgen

2007-06-01

We have developed a chemical vapor deposition (CVD) process for the catalytic growth of carbon nanotubes (CNTs), anchored in a comose-type structure on top of porous alumina substrates. The mass-flow conditions of precursor and carrier gases and temperature distributions in the CVD reactor were studied by transient computational fluid dynamic simulation. Molecular-beam quadrupole mass spectroscopy (MB-QMS) has been used to analyze the gas phase during ferrocene CVD under reaction conditions (1073 K) in the boundary layer near the substrate. Field-emission (FE) properties of the nonaligned CNTs were measured for various coverages and pore diameters of the alumina. Samples with more dense CNT populations provided emitter-number densities up to 48,000 cm(-2) at an electric field of 6 V microm(-1). Samples with fewer but well-anchored CNTs in 22-nm pores yielded the highest current densities. Up to 83 mA cm(-2) at 7 V microm(-1) in dc mode and more than 200 mA cm(-2) at 11 V microm(-1) in pulsed diode operation have been achieved from a cathode size of 24 mm2.

Ageing, metabolism and cardiovascular disease.

PubMed

Costantino, Sarah; Paneni, Francesco; Cosentino, Francesco

2016-04-15

Age is one of the major risk factors associated with cardiovascular disease (CVD). About one-fifth of the world population will be aged 65 or older by 2030, with an exponential increase in CVD prevalence. It is well established that environmental factors (overnutrition, smoking, pollution, sedentary lifestyles) may lead to premature defects in mitochondrial functionality, insulin signalling, endothelial homeostasis and redox balance, fostering early senescent features. Over the last few years, molecular investigations have unveiled common signalling networks which may link the ageing process with deterioration of cardiovascular homeostasis and metabolic disturbances, namely insulin resistance. These different processes seem to be highly interconnected and their interplay may favour adverse vascular and cardiac phenotypes responsible for myocardial infarction, stroke and heart failure. In the present review, we carefully describe novel molecular cues underpinning ageing, metabolism and CVD. In particular, we describe a dynamic interplay between emerging pathways such as FOXOs, AMPK, SIRT1, p66(Shc) , JunD and NF-kB. This overview will provide the background for attractive molecular targets to prevent age-driven pathology in the vasculature and the heart. © 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society.

The Chemistry of Inorganic Precursors during the Chemical Deposition of Films on Solid Surfaces.

PubMed

Barry, Seán T; Teplyakov, Andrew V; Zaera, Francisco

2018-03-20

The deposition of thin solid films is central to many industrial applications, and chemical vapor deposition (CVD) methods are particularly useful for this task. For one, the isotropic nature of the adsorption of chemical species affords even coverages on surfaces with rough topographies, an increasingly common requirement in microelectronics. Furthermore, by splitting the overall film-depositing reactions into two or more complementary and self-limiting steps, as it is done in atomic layer depositions (ALD), film thicknesses can be controlled down to the sub-monolayer level. Thanks to the availability of a vast array of inorganic and metalorganic precursors, CVD and ALD are quite versatile and can be engineered to deposit virtually any type of solid material. On the negative side, the surface chemistry that takes place in these processes is often complex, and can include undesirable side reactions leading to the incorporation of impurities in the growing films. Appropriate precursors and deposition conditions need to be chosen to minimize these problems, and that requires a proper understanding of the underlying surface chemistry. The precursors for CVD and ALD are often designed and chosen based on their known thermal chemistry from inorganic chemistry studies, taking advantage of the vast knowledge developed in that field over the years. Although a good first approximation, however, this approach can lead to wrong choices, because the reactions of these precursors at gas-solid interfaces can be quite different from what is seen in solution. For one, solvents often aid in the displacement of ligands in metalorganic compounds, providing the right dielectric environment, temporarily coordinating to the metal, or facilitating multiple ligand-complex interactions to increase reaction probabilities; these options are not available in the gas-solid reactions associated with CVD and ALD. Moreover, solid surfaces act as unique "ligands", if these reactions are to be viewed from the point of view of the metalorganic complexes used as precursors: they are bulky and rigid, can provide multiple binding sites for a single reaction, and can promote unique bonding modes, especially on metals, which have delocalized electronic structures. The differences between the molecular and surface chemistry of CVD and ALD precursors can result in significant variations in their reactivity, ultimately leading to unpredictable properties in the newly grown films. In this Account, we discuss some of the main similarities and differences in chemistry that CVD/ALD precursors follow on surfaces when contrasted against their known behavior in solution, with emphasis on our own work but also referencing other key contributions. Our approach is unique in that it combines expertise from the inorganic, surface science, and quantum-mechanics fields to better understand the mechanistic details of the chemistry of CVD and ALD processes and to identify new criteria to consider when designing CVD/ALD precursors.

Interlayer utilization (including metal borides) for subsequent deposition of NSD films via microwave plasma CVD on 316 and 440C stainless steels

NASA Astrophysics Data System (ADS)

Ballinger, Jared

Diamond thin films have promising applications in numerous fields due to the extreme properties of diamonds in conjunction with the surface enhancement of thin films. Biomedical applications are numerous including temporary implants and various dental and surgical instruments. The unique combination of properties offered by nanostructured diamond films that make it such an attractive surface coating include extreme hardness, low obtainable surface roughness, excellent thermal conductivity, and chemical inertness. Regrettably, numerous problems exist when attempting to coat stainless steel with diamond generating a readily delaminated film: outward diffusion of iron to the surface, inward diffusion of carbon limiting necessary surface carbon precursor, and the mismatch between the coefficients of thermal expansion yielding substantial residual stress. While some exotic methods have been attempted to overcome these hindrances, the most common approach is the use of an intermediate layer between the stainless steel substrate and the diamond thin film. In this research, both 316 stainless steel disks and 440C stainless steel ball bearings were tested with interlayers including discrete coatings and graded, diffusion-based surface enhancements. Titanium nitride and thermochemical diffusion boride interlayers were both examined for their effectiveness at allowing for the growth of continuous and adherent diamond films. Titanium nitride interlayers were deposited by cathodic arc vacuum deposition on 440C bearings. Lower temperature diamond processing resulted in improved surface coverage after cooling, but ultimately, both continuity and adhesion of the nanostructured diamond films were unacceptable. The ability to grow quality diamond films on TiN interlayers is in agreement with previous work on iron and low alloy steel substrates, and the similarly seen inadequate adhesion strength is partially a consequence of the lacking establishment of an interfacial carbide phase. Surface boriding was implemented using the novel method of microwave plasma CVD with a mixture of hydrogen and diborane gases. On 440C bearings, dual phase boride layers of Fe2B and FeB were formed which supported adhered nanostructured diamond films. Continuity of the films was not seamless with limited regions remaining uncoated potentially corresponding to delamination of the film as evidenced by the presence of tubular structures presumably composed of sp2 bonded carbon. Surface boriding of 316 stainless steel discs was conducted at various powers and pressures to achieve temperatures ranging from 550-800 °C. The substrate boriding temperature was found to substantially influence the resultant interlayer by altering the metal boride(s) present. The lowest temperatures produced an interlayer where CrB was the single detected phase, higher temperatures yielded the presence of only Fe2B, and a combination of the two phases resulted from an intermediate boriding temperature. Compared with the more common, commercialized boriding methods, this a profound result given the problems posed by the FeB phase in addition to other advantages offered by CVD processes and microwave generated plasmas in general. Indentation testing of the boride layers revealed excellent adhesion strength for all borided interlayers, and above all, no evidence of cracking was observed for a sole Fe2B phase. As with boriding of 440C bearings, subsequent diamond deposition was achieved on these interlayers with substantially improved adhesion strength relative to diamond coated TiN interlayers. Both XRD and Raman spectroscopy confirmed a nanostructured diamond film with interfacial chromium carbides responsible for enhanced adhesion strength. Interlayers consisting solely of Fe2B have displayed an ability to support fully continuous nanostructured diamond films, yet additional study is required for consistent reproduction. This is in good agreement with initial work on pack borided high alloy steels to promote diamond film surface modification. The future direction for continued research of nanostructured diamond coatings on microwave plasma CVD borided stainless steel should further investigate the adhesion of both borided interlayers and subsequent NSD films in addition to short, interrupted diamond depositions to study the interlayer/diamond film interface.

Racial and Ethnic Disparities in Cardiovascular Disease: An Assessment of Obstetrician-Gynecologists' Knowledge, Attitudes, and Practice Patterns.

PubMed

Jones, Katherine M; Carter, Michele M; Schulkin, Jay

2015-06-01

African American and Hispanic women are disproportionately affected by cardiovascular disease (CVD) and its many risk factors. Obstetrician-gynecologists (OB/GYNs) play an integral role in well-woman care and have a unique opportunity to provide CVD counseling and screening to these at-risk and underserved groups. To assess whether OB/GYN race/ethnicity and OB/GYN practices with increasing minority patient populations predicted differences in OB/GYNs' knowledge, attitudes, and practice patterns relevant to racial/ethnic disparities in CVD. This study also sought to determine provider and patient-related barriers to CVD care. A questionnaire on CVD was mailed to 273 members of The American College of Obstetricians and Gynecologists in March-July 2013. African American and Hispanic OB/GYNs and OB/GYN practices with increasing minority patient populations were more knowledgeable of CVD disparities. These OB/GYNs reported greater concern for minority women's CVD risk relative to White OB/GYNs. Overall, OB/GYNs appear less knowledgeable and concerned with Hispanics' increased CVD risk relative to African Americans'. The most commonly reported provider and patient-related barriers to CVD care were time constraints, patient nonadherence to treatment recommendations, and inadequate training. It is likely that minority OB/GYNs and those with practices with increasing minority patient populations have greater exposure to women at risk for CVD. Dissemination of educational information regarding Hispanic women's CVD risk profile may improve OB/GYN knowledge, counseling, and screening. Increased training in CVD and multicultural competency during medical school and residency should help OB/GYNs overcome what they report as primary barriers to CVD care.

Polycystic ovary syndrome and early-onset preeclampsia: reproductive manifestations of increased cardiovascular risk.

PubMed

Veltman-Verhulst, Susanne M; van Rijn, Bas B; Westerveld, H Egbertine; Franx, Arie; Bruinse, Hein W; Fauser, Bart C J M; Goverde, Angelique J

2010-01-01

Primary prevention of cardiovascular disease (CVD) in women is a major healthcare issue. Detection of premenopausal women with increased risk of CVD could enhance prevention strategies and reduce first event-related morbidity and mortality. In this study, we argue that an unfavorable metabolic constitution in women may present itself early in life as a reproductive complication, such as polycystic ovary syndrome (PCOS) and preeclampsia. We evaluated the cardiovascular risk of women with a history of early-onset preeclampsia and women with PCOS and assessed their need for implementation of early risk factor-reduction strategies. We performed a standardized evaluation of 240 women with a history of early-onset preeclampsia and 456 women diagnosed with PCOS for established major CVD risk factors. Metabolic syndrome characteristics were analyzed per body mass index category. Mean age was 30.6 and 29.0 years for women with preeclampsia and PCOS, respectively. High percentages of metabolic syndrome were found in both groups (preeclampsia group, 14.6%; and PCOS group, 18.4%), with an incidence of greater than 50% in both groups of women if body mass index was greater than 30 kg/m. Overall, more than 90% of the women qualified for either lifestyle or medical intervention according to the American Heart Association guideline for CVD prevention in women. Women with PCOS and early-onset preeclampsia already show an unfavorable cardiovascular risk profile with high need for lifestyle or medical intervention at a young age. We therefore recommend an active role of the gynecologist in routine screening and follow-up of women with reproductive conditions linked to future cardiovascular risk.

Edward F. Adolph Distinguished Lecture: The remarkable anti-aging effects of aerobic exercise on systemic arteries

PubMed Central

2014-01-01

Cardiovascular diseases (CVD) remain the leading cause of morbidity and mortality in modern societies, and advancing age is the major risk factor for CVD. Arterial dysfunction, characterized by large elastic artery stiffening and endothelial dysfunction, is the key event leading to age-associated CVD. Our work shows that regular aerobic exercise inhibits large elastic artery stiffening with aging (optimizes arterial compliance) and preserves endothelial function. Importantly, among previously sedentary late middle-aged and older adults, aerobic exercise improves arterial stiffness and enhances endothelial function in most groups and, therefore, also can be considered a treatment for age-associated arterial dysfunction. The mechanisms by which regular aerobic exercise destiffens large elastic arteries are incompletely understood, but existing evidence suggests that reductions in oxidative stress associated with decreases in both adventitial collagen (fibrosis) and advanced glycation end-products (structural protein cross-linking molecules), play a key role. Aerobic exercise preserves endothelial function with aging by maintaining nitric oxide bioavailability via suppression of excessive superoxide-associated oxidative stress, and by inhibiting the development of chronic low-grade vascular inflammation. Recent work from our laboratory supports the novel hypothesis that aerobic exercise may exert these beneficial effects by directly inducing protection to aging arteries against multiple adverse factors to which they are chronically exposed. Regular aerobic exercise should be viewed as a “first line” strategy for prevention and treatment of arterial aging and a vital component of a contemporary public health approach for reducing the projected increase in population CVD burden. PMID:24855137

Edward F. Adolph Distinguished Lecture: The remarkable anti-aging effects of aerobic exercise on systemic arteries.

PubMed

Seals, Douglas R

2014-09-01

Cardiovascular diseases (CVD) remain the leading cause of morbidity and mortality in modern societies, and advancing age is the major risk factor for CVD. Arterial dysfunction, characterized by large elastic artery stiffening and endothelial dysfunction, is the key event leading to age-associated CVD. Our work shows that regular aerobic exercise inhibits large elastic artery stiffening with aging (optimizes arterial compliance) and preserves endothelial function. Importantly, among previously sedentary late middle-aged and older adults, aerobic exercise improves arterial stiffness and enhances endothelial function in most groups and, therefore, also can be considered a treatment for age-associated arterial dysfunction. The mechanisms by which regular aerobic exercise destiffens large elastic arteries are incompletely understood, but existing evidence suggests that reductions in oxidative stress associated with decreases in both adventitial collagen (fibrosis) and advanced glycation end-products (structural protein cross-linking molecules), play a key role. Aerobic exercise preserves endothelial function with aging by maintaining nitric oxide bioavailability via suppression of excessive superoxide-associated oxidative stress, and by inhibiting the development of chronic low-grade vascular inflammation. Recent work from our laboratory supports the novel hypothesis that aerobic exercise may exert these beneficial effects by directly inducing protection to aging arteries against multiple adverse factors to which they are chronically exposed. Regular aerobic exercise should be viewed as a "first line" strategy for prevention and treatment of arterial aging and a vital component of a contemporary public health approach for reducing the projected increase in population CVD burden. Copyright © 2014 the American Physiological Society.

Lack of supervision after residential cardiac rehabilitation increases cardiovascular risk factors.

PubMed

Berent, Robert; von Duvillard, Serge P; Auer, Johann; Sinzinger, Helmut; Schmid, Peter

2010-06-01

Cardiovascular rehabilitation (CR) is an important component of care for patients with cardiovascular disease (CVD) and has been well documented and promoted by various health organizations and position statements worldwide. The purpose of this study was to investigate whether patients readmitted to CR on average 16 months after their previous discharge, maintained the reduction in CVD risk factors, maintained or improved functional capacity, occurrence of adverse cardiovascular events, and possible modifications in prescribed medications. Five hundred and seventy patients (60+/-10 years) underwent cycle ergometry and blood sampling at the beginning, the end of 21+/-2 days of the previous CR, and again at readmission to CR. The CR consisted of cycling for 17+/-4 min at frequency of six times a week and daily walking for 45 min at 60-70% of the maximal individual heart rate. Blood total cholesterol, low-density lipoprotein-cholesterol, triglycerides, and body mass index decreased significantly during CR. Resting blood pressure, maximal performance (watts), maximal oxygen uptake, and heart rate recovery improved significantly in 1 min (P<0.001). At readmission, all traditional CVD risk factors increased significantly, although medication was unchanged and angiotensin-converting enzyme inhibitors were partly replaced by angiotensin II receptor antagonists. Exercise performance remained unchanged. At readmission, we observed an increase in CVD risk factors, although, physical fitness remained stable. Thus, failure of lifestyle modification after CR indicates the cause for concern. Reinforcement of home setting sessions of CR patients or other strategies to enhance long-term compliance to lifestyle changes could reduce the observed attrition in CR benefits.

l-Carnitine and heart disease.

PubMed

Wang, Zhong-Yu; Liu, Ying-Yi; Liu, Guo-Hui; Lu, Hai-Bin; Mao, Cui-Ying

2018-02-01

Cardiovascular disease (CVD) is a key cause of deaths worldwide, comprising 15-17% of healthcare expenditure in developed countries. Current records estimate an annual global average of 30 million cardiac dysfunction cases, with a predicted escalation by two-three folds for the next 20-30years. Although β-blockers and angiotensin-converting-enzymes are commonly prescribed to control CVD risk, hepatotoxicity and hematological changes are frequent adverse events associated with these drugs. Search for alternatives identified endogenous cofactor l-carnitine, which is capable of promoting mitochondrial β-oxidation towards a balanced cardiac energy metabolism. l-Carnitine facilitates transport of long-chain fatty acids into the mitochondrial matrix, triggering cardioprotective effects through reduced oxidative stress, inflammation and necrosis of cardiac myocytes. Additionally, l-carnitine regulates calcium influx, endothelial integrity, intracellular enzyme release and membrane phospholipid content for sustained cellular homeostasis. Carnitine depletion, characterized by reduced expression of "organic cation transporter-2" gene, is a metabolic and autosomal recessive disorder that also frequently associates with CVD. Hence, exogenous carnitine administration through dietary and intravenous routes serves as a suitable protective strategy against ventricular dysfunction, ischemia-reperfusion injury, cardiac arrhythmia and toxic myocardial injury that prominently mark CVD. Additionally, carnitine reduces hypertension, hyperlipidemia, diabetic ketoacidosis, hyperglycemia, insulin-dependent diabetes mellitus, insulin resistance, obesity, etc. that enhance cardiovascular pathology. These favorable effects of l-carnitine have been evident in infants, juvenile, young, adult and aged patients of sudden and chronic heart failure as well. This review describes the mechanism of action, metabolism and pharmacokinetics of l-carnitine. It specifically emphasizes upon the beneficial role of l-carnitine in cardiomyopathy. Copyright © 2017 Elsevier Inc. All rights reserved.

Processing - microstructure relationships of chemically vapor deposited zirconia fiber coating for environmentally durable silicon carbide/silicon carbide composites

NASA Astrophysics Data System (ADS)

Lee, Jinil

In SiC/SiC ceramic matrix composites, toughness is obtained by adding a fiber coating which provides a weak interface for crack deflection and debonding between the fiber and the matrix. However, the most commonly used fiber coatings, carbon and boron nitride, are unstable in oxidative environments. In the present study, the feasibility of using a chemically vapor deposited zirconia (CVD-ZrO 2) fiber coating as an oxidation-resistant interphase for SiC/SiC composites was investigated. The feasibility of the CVD-ZrO2 coating as a useful interphase for SiC/SiC composites was investigated with emphasis on developing critical processing-microstructure relationships. A study of morphological evolution in the CVD-ZrO2 coating suggested that a size-controlled displacive phase transformation from tetragonal ZrO2 (t-ZrO2) to monoclinic ZrO2 (m-ZrO2) was the key mechanism responsible for the weak interface behavior exhibited by the ZrO2 coating. The pre-delamination occurred as a result of (i) continuous formation of t-ZrO2 nuclei on the deposition surface; (ii) martensitic transformation of the tetragonal phase to a monoclinic phase upon reaching a critical grain size; and (iii) development of significant compressive hoop stresses due to the volume dilation associated with the transformation. We also discovered that low oxygen partial pressure in the CVD reactor was required for the nucleation of t-ZrO2 and was ultimately responsible for the delamination behavior. The effects of oxygen partial pressure on the nucleation behavior of the CVD-ZrO2 coating was systematically studied by intentionally adding the controlled amount of O2 into the CVD chamber. Characterization results suggested that the number density of t-ZrO2 nuclei apparently decreased with increasing the oxygen partial pressure from 0.004 to 1.6 Pa. Also, the coating layer became more columnar and contained larger m-ZrO2 grains. The observed relationships between the oxygen partial pressure and the morphological characteristics of the ZrO 2 coating were explained in the context of the grain size and oxygen deficiency effects which have been previously reported to cause the stabilization of the t-ZrO2 phase in bulk ZrO2 specimens.

Achieving best outcomes of patients with cardiovascular diseases in China by enhancing the quality of medical care and establishing a learning health care system

PubMed Central

Jiang, Lixin; Krumholz, Harlan M; Li, Xi; Li, Jing; Hu, Shengshou

2016-01-01

Summary China faces the immediate need of addressing the rapidly growing population with cardiovascular disease (CVD) events and the increasing numbers who are living with CVD. Despite progress in increasing access to services, China faces the dual challenge of addressing gaps in quality of care and producing more evidence to support clinical practice. In this article, we address opportunities to strengthen performance measurement, programs to improve quality of care and national capacity to produce high impact knowledge for clinical practice. Moreover, we propose recommendations, with implications for other conditions, for how China can immediately leverage its Hospital Quality Monitoring System and other existing national platforms to evaluate and improve performance, as well as generate new knowledge to inform clinical decisions and national policies. PMID:26466053

EULAR task force recommendations on annual cardiovascular risk assessment for patients with rheumatoid arthritis: an audit of the success of implementation in a rheumatology outpatient clinic.

PubMed

Ikdahl, Eirik; Rollefstad, Silvia; Olsen, Inge C; Kvien, Tore K; Hansen, Inger Johanne Widding; Soldal, Dag Magnar; Haugeberg, Glenn; Semb, Anne Grete

2015-01-01

EULAR recommendations for cardiovascular disease (CVD) risk management include annual CVD risk assessments for patients with rheumatoid arthritis (RA). We evaluated the recording of CVD risk factors (CVD-RF) in a rheumatology outpatient clinic, where EULAR recommendations had been implemented. Further, we compared CVD-RF recordings between a regular rheumatology outpatient clinic (RegROC) and a structured arthritis clinic (AC). In 2012, 1142 RA patients visited the rheumatology outpatient clinic: 612 attended RegROC and 530 attended AC. We conducted a search in the patient journals to ascertain the rate of CVD-RF recording. The overall CVD-RF recording rate was 40.1% in the rheumatology outpatient clinic, reflecting a recording rate of 59.1% in the AC and 23.6% in the RegROC. The odds ratios for having CVD-RFs recorded for patients attending AC compared to RegROC were as follows: blood pressure: 12.4, lipids: 5.0-6.0, glucose: 9.1, HbA1c: 6.1, smoking: 1.4, and for having all the CVD-RFs needed to calculate the CVD risk by the systematic coronary risk evaluation (SCORE): 21.0. The CVD-RF recording rate was low in a rheumatology outpatient clinic. However, a systematic team-based model was superior compared to a RegROC. Further measures are warranted to improve CVD-RF recording in RA patients.

Suicide in males and females with cardiovascular disease and comorbid depression.

PubMed

Hawkins, Michael; Schaffer, Ayal; Reis, Catherine; Sinyor, Mark; Herrmann, Nathan; Lanctôt, Krista L

2016-06-01

Myocardial infarction (MI) has been associated with an increased risk of suicide, further increased among individuals with a comorbid psychiatric illness. A paucity of studies have examined details of suicide among individuals with cardiovascular disease (CVD) and comorbid depression. We aimed to compare demographic, clinical and suicide-specific characteristics between suicide victims with CVD with depression (CVD+D) and without comorbid depression (CVD-D). Coroner data on suicide decedents with CVD (n=413) occurring in Toronto, Canada from 1998 to 2012 were collected. Characteristics were compared between the CVD+D and CVD-D groups. Regression analysis examined for gender differences in these groups. CVD+D subjects compared to CVD-D were more likely to have had a past suicide attempt (p=0.008), and to have experienced a bereavement (p=0.008) or financial stressor (p=0.005) in the past year. Each of these variables remained significantly associated with the presence of depression after the regression analysis. Within the CVD+D group, females were more likely to die from suicide by self-poisoning (p<0.0001) and males by shooting (p=0.001). Psychological autopsies were not available. The definition of CVD was broad and the accuracy of its diagnosis could not be confirmed. Individuals with CVD+D who died from suicide had significant differences in clinical characteristics and specific stressors compared to those without depression. These data may help to better characterize suicide risk and prevention in this vulnerable population. Copyright © 2016 Elsevier B.V. All rights reserved.

Electrical property of macroscopic graphene composite fibers prepared by chemical vapor deposition

NASA Astrophysics Data System (ADS)

Sun, Haibin; Fu, Can; Gao, Yanli; Guo, Pengfei; Wang, Chunlei; Yang, Wenchao; Wang, Qishang; Zhang, Chongwu; Wang, Junya; Xu, Junqi

2018-07-01

Graphene fibers are promising candidates in portable and wearable electronics due to their tiny volume, flexibility and wearability. Here, we successfully synthesized macroscopic graphene composite fibers via a two-step process, i.e. first electrospinning and then chemical vapor deposition (CVD). Briefly, the well-dispersed PAN nanofibers were sprayed onto the copper surface in an electrified thin liquid jet by electrospinning. Subsequently, CVD growth process induced the formation of graphene films using a PAN-solid source of carbon and a copper catalyst. Finally, crumpled and macroscopic graphene composite fibers were obtained from carbon nanofiber/graphene composite webs by self-assembly process in the deionized water. Temperature-dependent conduct behavior reveals that electron transport of the graphene composite fibers belongs to hopping mechanism and the typical electrical conductivity reaches 4.59 × 103 S m‑1. These results demonstrated that the graphene composite fibers are promising for the next-generation flexible and wearable electronics.

Epidemiology of ischemic heart disease in HIV.

PubMed

Triant, Virginia A; Grinspoon, Steven K

2017-11-01

The purpose of this review is to summarize and synthesize recent data on the risk of ischemic heart disease (IHD) in HIV-infected individuals. Recent studies in the field demonstrate an increasing impact of cardiovascular disease (CVD) on morbidity and mortality in HIV relative to AIDS-related diagnoses. Studies continue to support an approximately 1.5 to two-fold increased risk of IHD conferred by HIV, with specific risk varying by sex and virologic/immunologic status. Risk factors include both traditional CVD risk factors and novel, HIV-specific factors including inflammation and immune activation. Specific antiretroviral therapy (ART) drugs may increase CVD risk, yet the net effect of ART with viral suppression is beneficial with regard to CVD risk. Management of cardiovascular risk and prevention of CVD is complex, because current general population strategies target traditional CVD risk factors only. Extensive investigation is being directed at developing tailored CVD risk prediction algorithms and interventions to reduce CVD risk in HIV. Increased IHD risk is a significant clinical and public health challenge in HIV. The development and application of HIV-specific interventions to manage CVD risk factors and reduce CVD risk will improve the long-term health of this ageing population.

All-Cause and CVD Mortality in Native Hawaiians

PubMed Central

Aluli, N. Emmett; Reyes, Phillip W.; Brady, S. Kalani; Tsark, JoAnn U.; Jones, Kristina L.; Mau, Marjorie; Howard, Wm. J.; Howard, Barbara V.

2010-01-01

Aims Cardiovascular disease (CVD) is the leading cause of death among Native Hawaiians. In this article, all-cause and cardiovascular mortality rates among Native Hawaiians are examined, along with associated CVD risk factors. Methods A total of 855 Native Hawaiians (343 men and 512 women, ages 19–88) were examined as participants of the Cardiovascular Risk Clinics program (1992–1998) and underwent surveillance through September 2007. Cause of each death was determined by review of medical records, death certificates, newspapers, and through queries to community members. Results CVD accounted for 55% of deaths. Coronary heart disease (CHD) accounted for the majority of CVD deaths. CVD increased with age and was higher in those with diabetes, hypertension, or high low-density lipoprotein cholesterol (LDL-C). CVD rates were higher in men than in women and 4-fold higher in those with diabetes. In addition to age, diabetes, hypertension, and elevated LDL-C were major risk factors. Conclusions Diabetes is a major determinant of CVD in this population and most of the CVD is occurring in those with diabetes. Strategies to prevent diabetes and manage blood pressure and lipids should reduce CVD rates in Native Hawaiians. PMID:20392507

Prediction of cardiovascular risk in rheumatoid arthritis: performance of original and adapted SCORE algorithms.

PubMed

Arts, E E A; Popa, C D; Den Broeder, A A; Donders, R; Sandoo, A; Toms, T; Rollefstad, S; Ikdahl, E; Semb, A G; Kitas, G D; Van Riel, P L C M; Fransen, J

2016-04-01

Predictive performance of cardiovascular disease (CVD) risk calculators appears suboptimal in rheumatoid arthritis (RA). A disease-specific CVD risk algorithm may improve CVD risk prediction in RA. The objectives of this study are to adapt the Systematic COronary Risk Evaluation (SCORE) algorithm with determinants of CVD risk in RA and to assess the accuracy of CVD risk prediction calculated with the adapted SCORE algorithm. Data from the Nijmegen early RA inception cohort were used. The primary outcome was first CVD events. The SCORE algorithm was recalibrated by reweighing included traditional CVD risk factors and adapted by adding other potential predictors of CVD. Predictive performance of the recalibrated and adapted SCORE algorithms was assessed and the adapted SCORE was externally validated. Of the 1016 included patients with RA, 103 patients experienced a CVD event. Discriminatory ability was comparable across the original, recalibrated and adapted SCORE algorithms. The Hosmer-Lemeshow test results indicated that all three algorithms provided poor model fit (p<0.05) for the Nijmegen and external validation cohort. The adapted SCORE algorithm mainly improves CVD risk estimation in non-event cases and does not show a clear advantage in reclassifying patients with RA who develop CVD (event cases) into more appropriate risk groups. This study demonstrates for the first time that adaptations of the SCORE algorithm do not provide sufficient improvement in risk prediction of future CVD in RA to serve as an appropriate alternative to the original SCORE. Risk assessment using the original SCORE algorithm may underestimate CVD risk in patients with RA. 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/

Carotid Plaque Score and Risk of Cardiovascular Mortality in the Oldest Old: Results from the TOOTH Study.

PubMed

Hirata, Takumi; Arai, Yasumichi; Takayama, Michiyo; Abe, Yukiko; Ohkuma, Kiyoshi; Takebayashi, Toru

2018-01-01

Accumulating evidence suggests that predictability of traditional cardiovascular risk factors declines with advancing age. We investigated whether carotid plaque scores (CPSs) were associated with cardiovascular disease (CVD) death in the oldest old, and whether asymmetrical dimethylarginine (ADMA), a marker of endothelial dysfunction, moderated the association between the CPS and CVD death. We conducted a prospective cohort study of Japanese subjects aged ≥85 years without CVD at baseline. We followed this cohort for 6 years to investigate the association of CPS with CVD death via multivariable Cox proportional hazard analysis. We divided participants into three groups according to CPS (no, 0 points; low, 1.2-4.9 points; high, ≥5.0 points). The predictive value of CPS for estimating CVD death risk over CVD risk factors, including ADMA, was examined using C-statistics. We analyzed 347 participants (151 men, 196 women; mean age, 87.6 years), of which 135 (38.9%) had no carotid plaque at baseline, and 48 (13.8%) had high CPS. Of the total, 29 (8.4%) participants experienced CVD-related death during the study period. Multivariable analysis revealed a significant association of high CPS with CVD-related mortality relative to no CPS (hazard ratio, 3.90; 95% confidence interval: 1.47-10.39). ADMA was not associated with CVD death, but the significant association between CPS and CVD death was observed only in lower ADMA level. The addition of CPS to other risk factors improved the predictability of CVD death (p=0.032). High CPS correlated significantly with a higher CVD death risk in the oldest old with low cardiovascular risk. Ultrasound carotid plaque evaluation might facilitate risk evaluations of CVD death in the very old.

Impact of anti-rheumatic treatment on cardiovascular risk in Asian patients with rheumatoid arthritis.

PubMed

Cho, Soo-Kyung; Kim, Dam; Won, Soyoung; Lee, Jiyoung; Park, ByeongJu; Jang, Eun Jin; Bae, Sang-Cheol; Sung, Yoon-Kyoung

2018-02-01

To estimate the incidence of cardiovascular disease (CVD) in Asian patients with rheumatoid arthritis (RA) and to evaluate the impact of anti-rheumatic treatment on the development of CVD. A retrospective cohort of Asian patients with RA was established to identify the incidence rate (IR) of CVD in RA patients. The cohort was generated using the Korean National Healthcare claims database, which contained claims from Jan 2009 to Dec 2013. A total of 137,512 RA patients were identified; individuals with a history of CVD for 6 months or more before the index date were excluded. Nested case-control samples were drawn from the full study population with a case:control ratio of 1:4 (n = 7102 cases; n = 27,018 controls without CVD). A conditional multivariate regression model was used to evaluate the impact of anti-rheumatic treatment on the development of CVD in RA patients after matching for age, sex, RA index date, comorbidities, and drug use (e.g., antiplatelet agents and cholesterol-lowering agents). The IR for development of overall CVD in RA patients was 182.1 (95% CI: 178.4-185.9) per 10,000 person-years. In models adjusted for other CVD risk factors, disease-modifying anti-rheumatic drugs (DMARDs) (OR = 0.79) were protective against CVD, and biologic DMARDs were not significantly associated with CVD risk (OR = 0.85). Corticosteroids (OR = 1.26) and NSAIDs (nonselective NSAIDs: OR = 1.32, Cox-2 inhibitors: OR = 1.31) were risk factors for CVD in RA patients. The use of DMARDs is protective against CVD, while corticosteroids and NSAIDs increased the risk of CVD in RA patients. Copyright © 2018 Elsevier Inc. All rights reserved.

Standard cardiovascular disease risk algorithms underestimate the risk of cardiovascular disease in schizophrenia: evidence from a national primary care database.

PubMed

McLean, Gary; Martin, Julie Langan; Martin, Daniel J; Guthrie, Bruce; Mercer, Stewart W; Smith, Daniel J

2014-10-01

Schizophrenia is associated with increased cardiovascular mortality. Although cardiovascular disease (CVD) risk prediction algorithms are widely in the general population, their utility for patients with schizophrenia is unknown. A primary care dataset was used to compare CVD risk scores (Joint British Societies (JBS) score), cardiovascular risk factors, rates of pre-existing CVD and age of first diagnosis of CVD for schizophrenia (n=1997) relative to population controls (n=215,165). Pre-existing rates of CVD and the recording of risk factors for those without CVD were higher in the schizophrenia cohort in the younger age groups, for both genders. Those with schizophrenia were more likely to have a first diagnosis of CVD at a younger age, with nearly half of men with schizophrenia plus CVD diagnosed under the age of 55 (schizophrenia men 46.1% vs. control men 34.8%, p<0.001; schizophrenia women 28.9% vs. control women 23.8%, p<0.001). However, despite high rates of CVD risk factors within the schizophrenia group, only a very small percentage (3.2% of men and 7.5% of women) of those with schizophrenia under age 55 were correctly identified as high risk for CVD according to the JBS risk algorithm. The JBS2 risk score identified only a small proportion of individuals with schizophrenia under the age of 55 as being at high risk of CVD, despite high rates of risk factors and high rates of first diagnosis of CVD within this age group. The validity of CVD risk prediction algorithms for schizophrenia needs further research. Copyright © 2014 Elsevier B.V. All rights reserved.

Fabrication of nanostructured electrodes and interfaces using combustion CVD

NASA Astrophysics Data System (ADS)

Liu, Ying

Reducing fabrication and operation costs while maintaining high performance is a major consideration for the design of a new generation of solid-state ionic devices such as fuel cells, batteries, and sensors. The objective of this research is to fabricate nanostructured materials for energy storage and conversion, particularly porous electrodes with nanostructured features for solid oxide fuel cells (SOFCs) and high surface area films for gas sensing using a combustion CVD process. This research started with the evaluation of the most important deposition parameters: deposition temperature, deposition time, precursor concentration, and substrate. With the optimum deposition parameters, highly porous and nanostructured electrodes for low-temperature SOFCs have been then fabricated. Further, nanostructured and functionally graded La0.8Sr0.2MnO2-La 0.8SrCoO3-Gd0.1Ce0.9O2 composite cathodes were fabricated on YSZ electrolyte supports. Extremely low interfacial polarization resistances (i.e. 0.43 Ocm2 at 700°C) and high power densities (i.e. 481 mW/cm2 at 800°C) were generated at operating temperature range of 600°C--850°C. The original combustion CVD process is modified to directly employ solid ceramic powder instead of clear solution for fabrication of porous electrodes for solid oxide fuel cells. Solid particles of SOFC electrode materials suspended in an organic solvent were burned in a combustion flame, depositing a porous cathode on an anode supported electrolyte. Combustion CVD was also employed to fabricate highly porous and nanostructured SnO2 thin film gas sensors with Pt interdigitated electrodes. The as-prepared SnO2 gas sensors were tested for ethanol vapor sensing behavior in the temperature range of 200--500°C and showed excellent sensitivity, selectivity, and speed of response. Moreover, several novel nanostructures were synthesized using a combustion CVD process, including SnO2 nanotubes with square-shaped or rectangular cross sections, well-aligned ZnO nanorods, and two-dimensional ZnO flakes. Solid-state gas sensors based on single piece of these nanostructures demonstrated superior gas sensing performances. These size-tunable nanostructures could be the building blocks of or a template for fabrication of functional devices. In summary, this research has developed new ways for fabrication of high-performance solid-state ionic devices and has helped generating fundamental understanding of the correlation between processing conditions, microstructure, and properties of the synthesized structures.

Spatially controlled fabrication of a bright fluorescent nanodiamond-array with enhanced far-red Si-V luminescence.

PubMed

Singh, Sonal; Thomas, Vinoy; Martyshkin, Dmitry; Kozlovskaya, Veronika; Kharlampieva, Eugenia; Catledge, Shane A

2014-01-31

We demonstrate a novel approach to precisely pattern fluorescent nanodiamond-arrays with enhanced far-red intense photostable luminescence from silicon-vacancy (Si-V) defect centers. The precision-patterned pre-growth seeding of nanodiamonds is achieved by a scanning probe 'dip-pen' nanolithography technique using electrostatically driven transfer of nanodiamonds from 'inked' cantilevers to a UV-treated hydrophilic SiO2 substrate. The enhanced emission from nanodiamond dots in the far-red is achieved by incorporating Si-V defect centers in a subsequent chemical vapor deposition treatment. The development of a suitable nanodiamond ink and mechanism of ink transport, and the effect of humidity and dwell time on nanodiamond patterning are investigated. The precision patterning of as-printed (pre-CVD) arrays with dot diameter and dot height as small as 735 nm ± 27 nm and 61 nm ± 3 nm, respectively, and CVD-treated fluorescent ND-arrays with consistently patterned dots having diameter and height as small as 820 nm ± 20 nm and, 245 nm ± 23 nm, respectively, using 1 s dwell time and 30% RH is successfully achieved. We anticipate that the far-red intense photostable luminescence (~738 nm) observed from Si-V defect centers integrated in spatially arranged nanodiamonds could be beneficial for the development of next generation fluorescence-based devices and applications.

A general strategy toward graphitized carbon coating on iron oxides as advanced anodes for lithium-ion batteries.

PubMed

Ding, Chunyan; Zhou, Weiwei; Wang, Bin; Li, Xin; Wang, Dong; Zhang, Yong; Wen, Guangwu

2017-08-25

Integration of carbon materials with benign iron oxides is blazing a trail in constructing high-performance anodes for lithium-ion batteries (LIBs). In this paper, a unique general, simple, and controllable strategy is developed toward in situ uniform coating of iron oxide nanostructures with graphitized carbon (GrC) layers. The basic synthetic procedure only involves a simple dip-coating process for the loading of Ni-containing seeds and a subsequent Ni-catalyzed chemical vapor deposition (CVD) process for the growth of GrC layers. More importantly, the CVD treatment is conducted at a quite low temperature (450 °C) and with extremely facile liquid carbon sources consisting of ethylene glycol (EG) and ethanol (EA). The GrC content of the resulting hybrids can be controllably regulated by altering the amount of carbon sources. The electrochemical results reveal remarkable performance enhancements of iron oxide@GrC hybrids compared with pristine iron oxides in terms of high specific capacity, excellent rate and cycling performance. This can be attributed to the network-like GrC coating, which can improve not only the electronic conductivity but also the structural integrity of iron oxides. Moreover, the lithium storage performance of samples with different GrC contents is measured, manifesting that optimized electrochemical property can be achieved with appropriate carbon content. Additionally, the superiority of GrC coating is demonstrated by the advanced performance of iron oxide@GrC compared with its corresponding counterpart, i.e., iron oxides with amorphous carbon (AmC) coating. All these results indicate the as-proposed protocol of GrC coating may pave the way for iron oxides to be promising anodes for LIBs.

Circulating Branched-Chain Amino Acids and Incident Cardiovascular Disease in a Prospective Cohort of US Women.

PubMed

Tobias, Deirdre K; Lawler, Patrick R; Harada, Paulo H; Demler, Olga V; Ridker, Paul M; Manson, JoAnn E; Cheng, Susan; Mora, Samia

2018-04-01

Circulating branched-chain amino acids (BCAAs; isoleucine, leucine, and valine) are strong predictors of type 2 diabetes mellitus (T2D), but their association with cardiovascular disease (CVD) is uncertain. We hypothesized that plasma BCAAs are positively associated with CVD risk and evaluated whether this was dependent on an intermediate diagnosis of T2D. Participants in the Women's Health Study prospective cohort were eligible if free of CVD at baseline blood collection (n=27 041). Plasma metabolites were measured via nuclear magnetic resonance spectroscopy. Multivariable Cox regression models estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for BCAAs with incident CVD (myocardial infarction, stroke, and coronary revascularization). We confirmed 2207 CVD events over a mean 18.6 years of follow-up. Adjusting for age, body mass index, and other established CVD risk factors, total BCAAs were positively associated with CVD (per SD: HR, 1.13; 95% CI, 1.08-1.18), comparable to LDL-C (low-density lipoprotein cholesterol) with CVD (per SD: HR, 1.12; 95% CI, 1.07-1.17). BCAAs were associated with coronary events (myocardial infarction: HR, 1.16; 95% CI, 1.06-1.26; revascularization: HR, 1.17; 95% CI, 1.11-1.25), and borderline significant association with stroke (HR, 1.07; 95% CI, 0.99-1.15). The BCAA-CVD association was greater ( P interaction=0.036) among women who developed T2D before CVD (HR, 1.20; 95% CI, 1.08-1.32) versus women without T2D (HR, 1.08; 95% CI, 1.03-1.14). Adjusting for LDL-C, an established CVD risk factor, did not attenuate these findings; however, adjusting for HbA1c and insulin resistance eliminated the associations of BCAAs with CVD. Circulating plasma BCAAs were positively associated with incident CVD in women. Impaired BCAA metabolism may capture the long-term risk of the common cause underlying T2D and CVD. © 2018 American Heart Association, Inc.

Role of pharmacist in cardiovascular disease-related health promotion and in hypertension and dyslipidemia management: a cross-sectional study in the State of Qatar.

PubMed

El Hajj, Maguy Saffouh; Mahfoud, Ziyad R; Al Suwaidi, Jassim; Alkhiyami, Dania; Alasmar, Aya Riyad

2016-06-01

In Qatar, cardiovascular diseases (CVD) have recently become the leading cause of morbidity and mortality. Prevention, detection and management of CVD risk factors reduce CVD chance. The study objectives were to assess Qatar pharmacists' involvement in CVD health promotion, to identify the activities that they currently provide to patients with CVD risk factors, to describe their attitudes towards their involvement in CVD prevention and to assess their perceived barriers for provision of CVD prevention services We conducted a cross-sectional survey of community and ambulatory pharmacists in Qatar. Pharmacist characteristics, involvement in CVD-related activities along with their attitudes and perceived barriers were analysed using frequency distributions. Bivariate linear regression models were used to test for associations between CVD health promotion activity score and each variable. Variables with a P-value of 0.20 or less were included in the multivariate model. A total of 141 pharmacists completed the survey (response rate 60%). More than 70% responded with rarely or never to 6 out of the 10 CVD health promotion activities. Eighty-four per cent and 68% always or often describe to patients the appropriate time to take antihypertensive medications and the common medication adverse effects, respectively. Yet, 50% rarely or never review the medication refill history or provide adherence interventions. Lack of CVD educational materials was the top perceived barrier (55%) in addition to lack of having private counselling area (44.6%), and lack of time (38.3%). Females and community pharmacists were more involved in CVD health promotion (P = 0.046 and P = 0.017, respectively) than their counterparts. Health promotion practice increased with increasing attitudes score and decreased with increased barriers score (P = 0.012 and P = 0.001). The scope of pharmacy practice in CVD prevention is limited in Qatar. Efforts need to be exerted to increase pharmacists' involvement in CVD prevention. © 2015 John Wiley & Sons, Ltd.

In-situ sensing using mass spectrometry and its use for run-to-run control on a W-CVD cluster tool

NASA Astrophysics Data System (ADS)

Gougousi, T.; Sreenivasan, R.; Xu, Y.; Henn-Lecordier, L.; Rubloff, G. W.; Kidder, , J. N.; Zafiriou, E.

2001-01-01

A 300 amu closed-ion-source RGA (Leybold-Inficon Transpector 2) sampling gases directly from the reactor of an ULVAC ERA-1000 cluster tool has been used for real time process monitoring of a W CVD process. The process involves H2 reduction of WF6 at a total pressure of 67 Pa (0.5 torr) to produce W films on Si wafers heated at temperatures around 350 °C. The normalized RGA signals for the H2 reagent depletion and the HF product generation were correlated with the W film weight as measured post-process with an electronic microbalance for the establishment of thin-film weight (thickness) metrology. The metrology uncertainty (about 7% for the HF product) was limited primarily by the very low conversion efficiency of the W CVD process (around 2-3%). The HF metrology was then used to drive a robust run-to-run control algorithm, with the deposition time selected as the manipulated (or controlled) variable. For that purpose, during a 10 wafer run, a systematic process drift was introduced as a -5 °C processing temperature change for each successive wafer, in an otherwise unchanged process recipe. Without adjustment of the deposition time the W film weight (thickness) would have declined by about 50% by the 10th wafer. With the aid of the process control algorithm, an adjusted deposition time was computed so as to maintain constant HF sensing signal, resulting in weight (thickness) control comparable to the accuracy of the thickness metrology. These results suggest that in-situ chemical sensing, and particularly mass spectrometry, provide the basis for wafer state metrology as needed to achieve run-to-run control. Furthermore, since the control accuracy was consistent with the metrology accuracy, we anticipate significant improvements for processes as used in manufacturing, where conversion rates are much higher (40-50%) and corresponding signals for metrology will be much larger.

Cognitive vulnerability to depression during middle childhood: Stability and associations with maternal affective styles and parental depression

PubMed Central

Hayden, Elizabeth P.; Olino, Thomas M.; Mackrell, Sarah V.M.; Jordan, Patricia L.; Desjardins, Jasmine; Katsiroumbas, Patrice

2014-01-01

Theories of cognitive vulnerability to depression (CVD) imply that CVD is early-emerging and trait-like; however, little longitudinal work has tested this premise in middle childhood, or examined theoretically relevant predictors of child CVD. We examined test–retest correlations of self-referent encoding task performance and self-reported attributional styles and their associations with parental characteristics in 205 seven-year-olds. At baseline, child CVD was assessed, structured clinical interviews were conducted with parents, and ratings of observed maternal affective styles were made. Children’s CVD was re-assessed approximately one and two years later. Both measures of children’s CVD were prospectively and concurrently associated with children’s depressive symptoms and showed modest stability. Multilevel modeling indicated that maternal criticism and paternal depression were related to children’s CVD. Findings indicate that even early-emerging CVD is a valid marker of children’s depression risk. PMID:25392596

The role of the apelinergic and vasopressinergic systems in the regulation of the cardiovascular system and the pathogenesis of cardiovascular disease.

PubMed

Czarzasta, Katarzyna; Cudnoch-Jedrzejewska, Agnieszka

2014-01-01

Research studies indicate a role of the apelinergic and vasopressinergic systems both in the regulation of the cardiovascular system and the pathogenesis of CVD, including in such settings as obesity and stress. Based on these data, it may be suggested that interactions between these systems underlie numerous physiological and pathophysiological processes, some of them related to the cardiovascular system. Better understanding of the role of these systems and their interactions, both physiological and related to the pathogenesis of CVD, will allow further advances in prevention and drug therapy.

Synthesis and Application of Graphene Based Nanomaterials

NASA Astrophysics Data System (ADS)

Peng, Zhiwei

Graphene, a two-dimensional sp2-bonded carbon material, has recently attracted major attention due to its excellent electrical, optical and mechanical properties. Depending on different applications, graphene and its derived hybrid nanomaterials can be synthesized by either bottom-up chemical vapor deposition (CVD) methods for electronics, or various top-down chemical reaction methods for energy generation and storage devices. My thesis begins with the investigation of CVD synthesis of graphene thin films in Chapter 1, including the direct growth of bilayer graphene on insulating substrates and synthesis of "rebar graphene": a hybrid structure with graphene and carbon or boron nitride nanotubes. Chapter 2 discusses the synthesis of nanoribbon-shaped materials and their applications, including splitting of vertically aligned multi-walled carbon nanotube carpets for supercapacitors, synthesis of dispersable ferromagnetic graphene nanoribbon stacks with enhanced electrical percolation properties in magnetic field, graphene nanoribbon/SnO 2 nanocomposite for lithium ion batteries, and enhanced electrocatalysis for hydrogen evolution reactions from WS2 nanoribbons. Next, Chapter 3 discusses graphene coated iron oxide nanomaterials and their use in energy storage applications. Finally, Chapter 4 introduces the development, characterization, and fabrication of laser induced graphene and its application as supercapacitors.

Carbon Coated Boron Nitride Nanosheets for Polymer Nanocomposites with Enhanced Dielectric Performance

PubMed Central

Yang, Minhao; Zhao, Hang; He, Delong; Hu, Chaohe; Chen, Haowei; Bai, Jinbo

2017-01-01

Carbon coated boron nitride nanosheets (BNNSs@C) hybrids with different carbon contents were synthesized by a chemical vapor deposition (CVD) method. The content of carbon in as-obtained BNNSs@C hybrids could be precisely adjusted from 2.50% to 22.62% by controlling the carbon deposition time during the CVD procedure. Afterward, the BNNSs@C hybrids were subsequently incorporated into the polyvinylidene fluoride (PVDF) matrix to fabricate the BNNSs@C/PVDF nanocomposites through a combination of solution and melting blending methods. The dielectric properties of the as-obtained BNNSs@C/PVDF nanocomposites could be accurately tuned by adjusting the carbon content. The resultant nanocomposites could afford a high dielectric constant about 39 (103 Hz) at BNNSs@C hybrids loading of 30 vol %, which is 4.8 times larger than that of pristine BNNSs-filled ones at the same filler loading, and 3.5 times higher than that of pure PVDF matrix. The largely enhanced dielectric performance could be ascribed to the improved interfacial polarizations of BNNSs/carbon and carbon/PVDF interfaces. The approach reported here offers an effective and alternative method to fabricate high-performance dielectric nanocomposites, which could be potentially applied to the embedded capacitors with high dielectric performance. PMID:28773105

Low-temperature formation of crystalline Si:H/Ge:H heterostructures by plasma-enhanced CVD in combination with Ni-nanodots seeding nucleation

NASA Astrophysics Data System (ADS)

Lu, Yimin; Makihara, Katsunori; Takeuchi, Daichi; Ikeda, Mitsuhisa; Ohta, Akio; Miyazaki, Seiichi

2017-06-01

Hydrogenated microcrystalline (µc) Si/Ge heterostructures were prepared on quartz substrates by plasma-enhanced chemical vapor deposition (CVD) from VHF inductively coupled plasma of SiH4 just after GeH4 employing Ni nanodots (NDs) as seeds for crystalline nucleation. The crystallinity of the films and the progress of grain growth were characterized by Raman scattering spectroscopy and atomic force microscopy (AFM), respectively. When the Ge films were grown on Ni-NDs at 250 °C, the growth of µc-Ge films with crystallinity as high as 80% was realized without an amorphous phase near the Ge film/quartz substrate interface. After the subsequent Si film deposition at 250 °C, fine grains were formed in the early stages of film growth on µc-Ge films with compositional mixing (µc-Si0.85Ge0.15:H) caused by the release of large lattice mismatch between c-Si and c-Ge. With further increase in Si:H film thickness, the formation of large grain structures accompanied by fine grains was promoted. These results suggest that crystalline Si/Ge heterojunctions can be used for efficient carrier collection in solar cell application.

Screening for Cardiovascular Disease Risk With Electrocardiography: US Preventive Services Task Force Recommendation Statement.

PubMed

Curry, Susan J; Krist, Alex H; Owens, Douglas K; Barry, Michael J; Caughey, Aaron B; Davidson, Karina W; Doubeni, Chyke A; Epling, John W; Kemper, Alex R; Kubik, Martha; Landefeld, C Seth; Mangione, Carol M; Silverstein, Michael; Simon, Melissa A; Tseng, Chien-Wen; Wong, John B

2018-06-12

Cardiovascular disease (CVD), which encompasses atherosclerotic conditions such as coronary heart disease, cerebrovascular disease, and peripheral arterial disease, is the most common cause of death among adults in the United States. Treatment to prevent CVD events by modifying risk factors is currently informed by CVD risk assessment with tools such as the Framingham Risk Score or the Pooled Cohort Equations, which stratify individual risk to inform treatment decisions. To update the 2012 US Preventive Services Task Force (USPSTF) recommendation on screening for coronary heart disease with electrocardiography (ECG). The USPSTF reviewed the evidence on whether screening with resting or exercise ECG improves health outcomes compared with the use of traditional CVD risk assessment alone in asymptomatic adults. For asymptomatic adults at low risk of CVD events (individuals with a 10-year CVD event risk less than 10%), it is very unlikely that the information from resting or exercise ECG (beyond that obtained with conventional CVD risk factors) will result in a change in the patient's risk category as assessed by the Framingham Risk Score or Pooled Cohort Equations that would lead to a change in treatment and ultimately improve health outcomes. Possible harms are associated with screening with resting or exercise ECG, specifically the potential adverse effects of subsequent invasive testing. For asymptomatic adults at intermediate or high risk of CVD events, there is insufficient evidence to determine the extent to which information from resting or exercise ECG adds to current CVD risk assessment models and whether information from the ECG results in a change in risk management and ultimately reduces CVD events. As with low-risk adults, possible harms are associated with screening with resting or exercise ECG in asymptomatic adults at intermediate or high risk of CVD events. The USPSTF recommends against screening with resting or exercise ECG to prevent CVD events in asymptomatic adults at low risk of CVD events. (D recommendation) The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of screening with resting or exercise ECG to prevent CVD events in asymptomatic adults at intermediate or high risk of CVD events. (I statement).

Tungsten Contact and Line Resistance Reduction with Advanced Pulsed Nucleation Layer and Low Resistivity Tungsten Treatment

NASA Astrophysics Data System (ADS)

Chandrashekar, Anand; Chen, Feng; Lin, Jasmine; Humayun, Raashina; Wongsenakhum, Panya; Chang, Sean; Danek, Michal; Itou, Takamasa; Nakayama, Tomoo; Kariya, Atsushi; Kawaguchi, Masazumi; Hizume, Shunichi

2010-09-01

This paper describes electrical testing results of new tungsten chemical vapor deposition (CVD-W) process concepts that were developed to address the W contact and bitline scaling issues on 55 nm node devices. Contact resistance (Rc) measurements in complementary metal oxide semiconductor (CMOS) devices indicate that the new CVD-W process for sub-32 nm and beyond - consisting of an advanced pulsed nucleation layer (PNL) combined with low resistivity tungsten (LRW) initiation - produces a 20-30% drop in Rc for diffused NiSi contacts. From cross-sectional bright field and dark field transmission electron microscopy (TEM) analysis, such Rc improvement can be attributed to improved plugfill and larger in-feature W grain size with the advanced PNL+LRW process. More experiments that measured contact resistance for different feature sizes point to favorable Rc scaling with the advanced PNL+LRW process. Finally, 40% improvement in line resistance was observed with this process as tested on 55 nm embedded dynamic random access memory (DRAM) devices, confirming that the advanced PNL+LRW process can be an effective metallization solution for sub-32 nm devices.

Fabrication of high quality carbonaceous coating on Cu nanoparticle using poly(vinyl pyrrolidone) and its application for oxidation prevention

NASA Astrophysics Data System (ADS)

Pyo, Youngjun; Choi, Dahyun; Son, Yeon-Ho; Kang, Suhee; Yoon, Eric H.; Jung, Seung-Boo; Kim, Yongil; Sunyong Lee, Caroline

2016-05-01

A novel method of carbonaceous coating on the surface of copper particles was developed through a chemical vapor deposition (CVD) process to prevent the oxidation of copper nanoparticles (CNPs). The types of poly(vinyl pyrrolidone) (PVP) used were K-12 (M W 3,500) and K-30 (M W 45,000). The amounts of PVP used ranged from 10 to 50 wt %. Additionally, processing temperatures of 900 and 875 °C were tested and compared. The optimum CVD process conditions for the carbonaceous coating were as follows: 875 °C processing temperature, 50 wt % K12 PVP solution, and gas conditions of \\text{Ar}:\\text{H}2 = 1:1. The resistivity change in the fabricated copper pattern was confirmed that the initial resistivity value of the ink with a mixing ratio of carbonaceous-coated CNPs to 1-octanethiol-coated CNPs of 4:6 (w/w) maintained its initial resistivity value of 2.93 × 10-7 Ω·m for more than 210 days.

Development Status of a CVD System to Deposit Tungsten onto UO2 Powder via the WCI6 Process

NASA Technical Reports Server (NTRS)

Mireles, O. R.; Kimberlin, A.; Broadway, J.; Hickman, R.

2014-01-01

Nuclear Thermal Propulsion (NTP) is under development for deep space exploration. NTP's high specific impulse (> 850 second) enables a large range of destinations, shorter trip durations, and improved reliability. W-60vol%UO2 CERMET fuel development efforts emphasize fabrication, performance testing and process optimization to meet service life requirements. Fuel elements must be able to survive operation in excess of 2850 K, exposure to flowing hydrogen (H2), vibration, acoustic, and radiation conditions. CTE mismatch between W and UO2 result in high thermal stresses and lead to mechanical failure as a result UO2 reduction by hot hydrogen (H2) [1]. Improved powder metallurgy fabrication process control and mitigated fuel loss can be attained by coating UO2 starting powders within a layer of high density tungsten [2]. This paper discusses the advances of a fluidized bed chemical vapor deposition (CVD) system that utilizes the H2-WCl6 reduction process.

Graphene growth on Ge(100)/Si(100) substrates by CVD method.

PubMed

Pasternak, Iwona; Wesolowski, Marek; Jozwik, Iwona; Lukosius, Mindaugas; Lupina, Grzegorz; Dabrowski, Pawel; Baranowski, Jacek M; Strupinski, Wlodek

2016-02-22

The successful integration of graphene into microelectronic devices is strongly dependent on the availability of direct deposition processes, which can provide uniform, large area and high quality graphene on nonmetallic substrates. As of today the dominant technology is based on Si and obtaining graphene with Si is treated as the most advantageous solution. However, the formation of carbide during the growth process makes manufacturing graphene on Si wafers extremely challenging. To overcome these difficulties and reach the set goals, we proposed growth of high quality graphene layers by the CVD method on Ge(100)/Si(100) wafers. In addition, a stochastic model was applied in order to describe the graphene growth process on the Ge(100)/Si(100) substrate and to determine the direction of further processes. As a result, high quality graphene was grown, which was proved by Raman spectroscopy results, showing uniform monolayer films with FWHM of the 2D band of 32 cm(-1).

Correlates for cardiovascular diseases among diabetic/hypertensive patients attending outreach clinics in two Nairobi slums, Kenya

PubMed Central

Mugure, Gladys; Karama, Mohamed; Kyobutungi, Catherine; Karanja, Simon

2014-01-01

Introduction Cardiovascular diseases (CVD) are the leading cause of death in the world. Over 80% of CVD related deaths occur in low- and middle-income countries (LMICs). Diabetes and hypertension, whose prevalence in Kenya is on the rise, are major risk factors for CVD. Despite this, studies indicate that awareness on the management of risk factors for CVD among diabetic/hypertensive patients in African populations is generally low. The aim of the study was to determine the risk factors for CVD among diabetic and/or hypertensive patients attending diabetes and hypertension management clinics in Korogocho and Viwandani slums of Nairobi. Methods Data were collected using questionnaires administered to 206 diabetic/hypertensive patients attending the clinics between July 2010 and February 2011. A review of these patients’ medical records was done to determine the history of CVD outcomes such as hypertensive heart diseases, stroke and peripheral arterial diseases. Results Majority (66.5%) of the study participants were females mainly in the 51-65 age category. The study findings revealed that 73 (33.4%) respondents had CVD outcomes. In addition, 41.8% of the respondents were not aware of the causes of diabetes/hypertension. Age category 51-65 years had the highest (43.8%) number of respondents with CVD. Sex of the respondents and awareness of the link between hypertension and CVD were significantly associated with CVD outcomes (p<0.05) among the respondents. Conclusion Measures to improve awareness levels among patients at high risk of CVD outcomes are needed to complement other measures to reduce CVD risk among such patients. PMID:25852804

Gender/Sex as a Social Determinant of Cardiovascular Risk.

PubMed

O'Neil, Adrienne; Scovelle, Anna J; Milner, Allison J; Kavanagh, Anne

2018-02-20

The social gradient for cardiovascular disease (CVD) onset and outcomes is well established. The American Heart Association's Social Determinants of Risk and Outcomes of Cardiovascular Disease Scientific Statement advocates looking beyond breakthroughs in biological science toward a social determinants approach that focuses on socioeconomic position, race and ethnicity, social support, culture and access to medical care, and residential environments to curb the burden of CVD going forward. Indeed, the benefits of this approach are likely to be far reaching, enhancing the positive effects of advances in CVD related to prevention and treatment while reducing health inequities that contribute to CVD onset and outcomes. It is disappointing that the role of gender has been largely neglected despite being a critical determinant of cardiovascular health. It is clear that trajectories and outcomes of CVD differ by biological sex, yet the tendency for sex and gender to be conflated has contributed to the idea that both are constant or fixed with little room for intervention. Rather, as distinct from biological sex, gender is socially produced. Overlaid on biological sex, gender is a broad term that shapes and interacts with one's cognition to guide norms, roles, behaviors, and social relations. It is a fluid construct that varies across time, place, and life stage. Gender can interact with biological sex and, indeed, other social determinants, such as ethnicity and socioeconomic position, to shape cardiovascular health from conception, through early life when health behaviors and risk factors are shaped, into adolescence and adulthood. This article will illustrate how gender shapes the early adoption of health behaviors in childhood, adolescence, and young adulthood by focusing on physical activity, drinking, and smoking behaviors (including the influence of role modeling). We will also discuss the role of gender in psychosocial stress with a focus on trauma from life events (childhood assault and intimate partner violence) and work, home, and financial stresses. We conclude by exploring potential biological pathways, with a focus on autonomic functioning, which may underpin gender as a social determinant of cardiovascular health. Finally, we discuss implications for cardiovascular treatment and awareness campaigns and consider whether gender equality strategies could reduce the burden of CVD for men and women at the population level. © 2018 American Heart Association, Inc.

Dietary B Vitamin Intake Is Associated with Lower Urinary Monomethyl Arsenic and Oxidative Stress Marker 15-F2t-Isoprostane among New Hampshire Adults.

PubMed

Howe, Caitlin G; Li, Zhigang; Zens, Michael S; Palys, Thomas; Chen, Yu; Channon, Jacqueline Y; Karagas, Margaret R; Farzan, Shohreh F

2017-12-01

Background: Arsenic exposure has been associated with an increased risk of cardiovascular disease (CVD). Growing evidence suggests that B vitamins facilitate arsenic metabolism and may protect against arsenic toxicity. However, to our knowledge, few studies have evaluated this in US populations. Objective: Our objective was to examine whether higher B vitamin intake is associated with enhanced arsenic metabolism and lower concentrations of preclinical markers of CVD among New Hampshire adults. Methods: We used weighted quantile sum (WQS) regression to evaluate the collective impact of 6 dietary B vitamins (thiamin, riboflavin, folate, niacin, and vitamins B-6 and B-12) on 1 ) the proportion of arsenic metabolites in urine and 2 ) 6 CVD-related markers [including urinary 15-F 2t -isoprostane (15-F 2t -IsoP)] among 418 participants (26-75 y of age) from the New Hampshire Health Study. Contributions of arsenic metabolites to B vitamin-CVD marker associations were also explored in structural equation models. Results: In WQS models, the weighted sum of B vitamin intakes from food sources was inversely associated with the proportion of monomethyl arsenic species in urine (uMMA) (β: -1.03; 95% CI: -1.91, -0.15; P = 0.02). Thiamin and vitamins B-6 and B-12 contributed the most to this association, whereas riboflavin had a negligible effect. Higher overall B vitamin intake was also inversely associated with 15-F 2t -IsoP (β: -0.21; 95% CI: -0.32, -0.11; P < 0.01), with equal contributions from the 6 B vitamins, which was partially explained by differences in the proportion of uMMA (indirect effect β: -0.01; 95% CI: -0.04, -0.00). Conclusions: Among New Hampshire adults, higher intakes of certain B vitamins (particularly thiamin and vitamins B-6 and B-12 from food sources) may reduce the proportion of uMMA, an intermediate of arsenic metabolism that has been associated with an increased risk of CVD. Higher overall B vitamin intake may also reduce urinary 15-F 2t -IsoP, a marker of oxidative stress and potential risk factor for CVD, in part by reducing the proportion of uMMA. © 2017 American Society for Nutrition.

Development of Cardiovascular Quality Indicators for Rheumatoid Arthritis: Results from an International Expert Panel Using a Novel Online Process

PubMed Central

Barber, Claire E. H.; Marshall, Deborah A; Alvarez, Nanette; John Mancini, G. B.; Lacaille, Diane; Keeling, Stephanie; Aviña-Zubieta, J. Antonio; Khodyakov, Dmitry; Barnabe, Cheryl; Faris, Peter; Smith, Alexa; Noormohamed, Raheem; Hazlewood, Glen; Martin, Liam O.; Esdaile, John M.

2016-01-01

Objective Patients with rheumatoid arthritis (RA) have a high risk of premature cardiovascular disease (CVD). We developed CVD quality indicators (QIs) for screening and use in Rheumatology clinics. Methods A systematic review of the literature on CVD risk reduction in RA and the general population was conducted. Based on the best practices identified from this review, a draft set of 12 candidate QIs were presented to a Canadian panel of rheumatologists and cardiologists (n=6) from three academic centers to achieve consensus on the QI specifications. The resulting 11 QIs were then evaluated by an online modified-Delphi panel of multidisciplinary health professionals and patients (n = 43) to determine their relevance, validity and feasibility in three rounds of online voting and threaded discussion using a modified RAND/UCLA Appropriateness Methodology. Results Response rates for the online panel were 86%. All 11 QIs were rated as highly relevant, valid and feasible (median rating ≥7 on a 1–9 scale) with no significant disagreement. The final QI set addresses the following themes: communication to primary care about increased CV risk in RA, CV risk assessment, defining smoking status and providing cessation counseling, screening and addressing hypertension, dyslipidemia and diabetes, exercise recommendations, body mass index screening and lifestyle counseling, minimizing corticosteroid use and communicating to patients at high risk of CVD about the risks/benefits of non-steroidal anti-inflammatory drugs. Conclusion Eleven QIs for CVD care in RA patients have been developed and are rated as highly relevant, valid and feasible by an international multidisciplinary panel. PMID:26178275

Photochemical CVD of Ru on functionalized self-assembled monolayers from organometallic precursors

NASA Astrophysics Data System (ADS)

Johnson, Kelsea R.; Arevalo Rodriguez, Paul; Brewer, Christopher R.; Brannaka, Joseph A.; Shi, Zhiwei; Yang, Jing; Salazar, Bryan; McElwee-White, Lisa; Walker, Amy V.

2017-02-01

Chemical vapor deposition (CVD) is an attractive technique for the metallization of organic thin films because it is selective and the thickness of the deposited film can easily be controlled. However, thermal CVD processes often require high temperatures which are generally incompatible with organic films. In this paper, we perform proof-of-concept studies of photochemical CVD to metallize organic thin films. In this method, a precursor undergoes photolytic decomposition to generate thermally labile intermediates prior to adsorption on the sample. Three readily available Ru precursors, CpRu(CO)2Me, (η3-allyl)Ru(CO)3Br, and (COT)Ru(CO)3, were employed to investigate the role of precursor quantum yield, ligand chemistry, and the Ru oxidation state on the deposition. To investigate the role of the substrate chemistry on deposition, carboxylic acid-, hydroxyl-, and methyl-terminated self-assembled monolayers were used. The data indicate that moderate quantum yields for ligand loss (φ ≥ 0.4) are required for ruthenium deposition, and the deposition is wavelength dependent. Second, anionic polyhapto ligands such as cyclopentadienyl and allyl are more difficult to remove than carbonyls, halides, and alkyls. Third, in contrast to the atomic layer deposition, acid-base reactions between the precursor and the substrate are more effective for deposition than nucleophilic reactions. Finally, the data suggest that selective deposition can be achieved on organic thin films by judicious choice of precursor and functional groups present on the substrate. These studies thus provide guidelines for the rational design of new precursors specifically for selective photochemical CVD on organic substrates.

Strain transfer across grain boundaries in MoS2 monolayers grown by chemical vapor deposition

NASA Astrophysics Data System (ADS)

Niehues, Iris; Blob, Anna; Stiehm, Torsten; Schmidt, Robert; Jadriško, Valentino; Radatović, Borna; Čapeta, Davor; Kralj, Marko; Michaelis de Vasconcellos, Steffen; Bratschitsch, Rudolf

2018-07-01

Monolayers of transition metal dichalcogenides (TMDC) mechanically exfoliated from bulk crystals have exceptional mechanical and optical properties. They are extremely flexible, sustaining mechanical strain of about 10% without breaking. Their optical properties dramatically change with applied strain. However, the fabrication of a large number of mechanical devices is tedious due to the micromechanical exfoliation process. Alternatively, monolayers can be grown by chemical vapor deposition (CVD) on the wafer scale, with the drawback of cracks and grain boundaries in the material. Therefore, it is important to investigate the mechanical properties of CVD-grown material and its potential as a material for mass production of nanomechanical devices. Here, we measure the optical absorption of CVD-grown MoS2 monolayers with applied uniaxial tensile strain. We derive a strain-dependent shift for the A exciton of  ‑42 meV/%. This value is identical to MoS2 monolayers, which are mechanically exfoliated from natural molybdenite crystals. Using angle-resolved second-harmonic generation spectroscopy, we find that the applied uniaxial tensile strain is fully transferred across grain boundaries of the CVD-grown monolayer. Our work demonstrates that large-area artificially grown MoS2 monolayers are promising for mass-produced nanomechanical devices.

Nutritional approach for designing meat-based functional food products with nuts.

PubMed

Olmedilla-Alonso, B; Granado-Lorencio, F; Herrero-Barbudo, C; Blanco-Navarro, I

2006-01-01

Meat and meat products are essential components of diets in developed countries and despite the convincing evidence that relate them to an increased risk for CVD, a growing consumption of meat products is foreseen. Epidemiological studies show that regular consumption of nuts, in general, and walnuts in particular, correlates inversely with myocardial infarction and ischaemic vascular disease. We assess the nutritional basis for and technological approach to the development of functional meat-based products potentially relevant in cardiovascular disease (CVD) risk reduction. Using the available strategies in the meat industry (reformulation processes) and a food-based approach, we address the design and development of restructured beef steak with added walnuts, potentially functional for CVD risk reduction. Its adequacy as a vehicle for active nutrients is confirmed by a pharmacokinetic pilot study in humans using gamma-tocopherol as an exposure biomarker in chylomicrons during the post-prandial state. Effect and potential "functionality" is being assessed by a dietary intervention study in subjects at risk and markers and indicators related to CVD are being evaluated. Within the conceptual framework of evidence-based medicine, development of meat-based functional products may become a useful approach for specific applications, with a potential market and health benefits of great importance at a population level.

Ultrasensitive label-free detection of DNA hybridization by sapphire-based graphene field-effect transistor biosensor

NASA Astrophysics Data System (ADS)

Xu, Shicai; Jiang, Shouzhen; Zhang, Chao; Yue, Weiwei; Zou, Yan; Wang, Guiying; Liu, Huilan; Zhang, Xiumei; Li, Mingzhen; Zhu, Zhanshou; Wang, Jihua

2018-01-01

Graphene has attracted much attention in biosensing applications for its unique properties. Because of one-atom layer structure, every atom of graphene is exposed to the environment, making the electronic properties of graphene are very sensitive to charged analytes. Therefore, graphene is an ideal material for transistors in high-performance sensors. Chemical vapor deposition (CVD) method has been demonstrated the most successful method for fabricating large area graphene. However, the conventional CVD methods can only grow graphene on metallic substrate and the graphene has to be transferred to the insulating substrate for further device fabrication. The transfer process creates wrinkles, cracks, or tears on the graphene, which severely degrade electrical properties of graphene. These factors severely degrade the sensing performance of graphene. Here, we directly fabricated graphene on sapphire substrate by high temperature CVD without the use of metal catalysts. The sapphire-based graphene was patterned and make into a DNA biosensor in the configuration of field-effect transistor. The sensors show high performance and achieve the DNA detection sensitivity as low as 100 fM (10-13 M), which is at least 10 times lower than prior transferred CVD G-FET DNA sensors. The use of the sapphire-based G-FETs suggests a promising future for biosensing applications.

Vertical heterostructures of MoS2 and graphene nanoribbons grown by two-step chemical vapor deposition for high-gain photodetectors.

PubMed

Yunus, Rozan Mohamad; Endo, Hiroko; Tsuji, Masaharu; Ago, Hiroki

2015-10-14

Heterostructures of two-dimensional (2D) layered materials have attracted growing interest due to their unique properties and possible applications in electronics, photonics, and energy. Reduction of the dimensionality from 2D to one-dimensional (1D), such as graphene nanoribbons (GNRs), is also interesting due to the electron confinement effect and unique edge effects. Here, we demonstrate a bottom-up approach to grow vertical heterostructures of MoS2 and GNRs by a two-step chemical vapor deposition (CVD) method. Single-layer GNRs were first grown by ambient pressure CVD on an epitaxial Cu(100) film, followed by the second CVD process to grow MoS2 over the GNRs. The MoS2 layer was found to grow preferentially on the GNR surface, while the coverage could be further tuned by adjusting the growth conditions. The MoS2/GNR nanostructures show clear photosensitivity to visible light with an optical response much higher than that of a 2D MoS2/graphene heterostructure. The ability to grow a novel 1D heterostructure of layered materials by a bottom-up CVD approach will open up a new avenue to expand the dimensionality of the material synthesis and applications.

THE MITOCHONDRIAL PARADIGM FOR CARDIOVASCULAR DISEASE SUSCEPTIBILITY AND CELLULAR FUNCTION: A COMPLEMENTARY CONCEPT TO MENDELIAN GENETICS

PubMed Central

Kryzwanski, David M.; Moellering, Douglas; Fetterman, Jessica L.; Dunham-Snary, Kimberly J.; Sammy, Melissa J.; Ballinger, Scott W.

2013-01-01

While there is general agreement that cardiovascular disease (CVD) development is influenced by a combination of genetic, environmental, and behavioral contributors, the actual mechanistic basis of how these factors initiate or promote CVD development in some individuals while others with identical risk profiles do not, is not clearly understood. This review considers the potential role for mitochondrial genetics and function in determining CVD susceptibility from the standpoint that the original features that molded cellular function were based upon mitochondrial-nuclear relationships established millions of years ago and were likely refined during prehistoric environmental selection events that today, are largely absent. Consequently, contemporary risk factors that influence our susceptibility to a variety of age-related diseases, including CVD were probably not part of the dynamics that defined the processes of mitochondrial – nuclear interaction, and thus, cell function. In this regard, the selective conditions that contributed to cellular functionality and evolution should be given more consideration when interpreting and designing experimental data and strategies. Finally, future studies that probe beyond epidemiologic associations are required. These studies will serve as the initial steps for addressing the provocative concept that contemporary human disease susceptibility is the result of selection events for mitochondrial function that increased chances for prehistoric human survival and reproductive success. PMID:21647091

ZnO synthesis by high vacuum plasma-assisted chemical vapor deposition using dimethylzinc and atomic oxygen

NASA Astrophysics Data System (ADS)

Barnes, Teresa M.; Hand, Steve; Leaf, Jackie; Wolden, Colin A.

2004-09-01

Zinc oxide thin films were produced by high vacuum plasma-assisted chemical vapor deposition (HVP-CVD) from dimethylzinc (DMZn) and atomic oxygen. HVP-CVD is differentiated from conventional remote plasma-enhanced CVD in that the operating pressures of the inductively coupled plasma (ICP) source and the deposition chamber are decoupled. Both DMZn and atomic oxygen effuse into the deposition chamber under near collisionless conditions. The deposition rate was measured as a function of DMZn and atomic oxygen flux on glass and silicon substrates. Optical emission spectroscopy and quadrupole mass spectrometry (QMS) were used to provide real time analysis of the ICP source and the deposition chamber. The deposition rate was found to be first order in DMZn pressure and zero order in atomic oxygen density. All films demonstrated excellent transparency and were preferentially orientated along the c-axis. The deposition chemistry occurs exclusively through surface-mediated reactions, since the collisionless transport environment eliminates gas-phase chemistry. QMS analysis revealed that DMZn was almost completely consumed, and desorption of unreacted methyl radicals was greatly accelerated in the presence of atomic oxygen. Negligible zinc was detected in the gas phase, suggesting that Zn was efficiently consumed on the substrate and walls of the reactor.

Indices of paraoxonase and oxidative status do not enhance the prediction of subclinical cardiovascular disease in mixed-ancestry South Africans.

PubMed

Macharia, M; Kengne, A P; Blackhurst, D M; Erasmus, R T; Hoffmann, M; Matsha, T E

2014-01-01

We evaluated the association of indices of paraoxonase (PON1) and oxidative status with subclinical cardiovascular disease (CVD) in mixed-ancestry South Africans. Participants were 491 adults (126 men) who were stratified by diabetes status and body mass index (BMI). Carotid intima-media thickness (CIMT) was used as a measure of subclinical CVD. Indices of PON1 and oxidative status were determined by measuring levels and activities (paraoxonase and arylesterase) of PON1, antioxidant activity (ferric reducing antioxidant power and trolox equivalent antioxidant capacity), and lipid peroxidation markers (malondialdehyde and oxidized LDL). Diabetic subjects (28.9%) displayed a significant decrease in PON1 status and antioxidant activity as well as increase in oxidized LDL and malondialdehyde. A similar profile was apparent across increasing BMI categories. CIMT was higher in diabetic than nondiabetic subjects (P < 0.0001) but showed no variation across BMI categories. Overall, CIMT correlated negatively with indices of antioxidant activity and positively with measures of lipid oxidation. Sex, age, BMI, and diabetes altogether explained 29.2% of CIMT, with no further improvement from adding PON1 and/or antioxidant status indices. Though indices of PON1 and oxidative status correlate with CIMT, their measurements may not be useful for identifying subjects at high CVD risk in this population.

Effects of Thickness and Amount of Carbon Nanofiber Coated Carbon Fiber on Improving the Mechanical Properties of Nanocomposites

PubMed Central

Ghaemi, Ferial; Ahmadian, Ali; Yunus, Robiah; Ismail, Fudziah; Rahmanian, Saeed

2016-01-01

In the current study, carbon nanofibers (CNFs) were grown on a carbon fiber (CF) surface by using the chemical vapor deposition method (CVD) and the influences of some parameters of the CVD method on improving the mechanical properties of a polypropylene (PP) composite were investigated. To obtain an optimum surface area, thickness, and yield of the CNFs, the parameters of the chemical vapor deposition (CVD) method, such as catalyst concentration, reaction temperature, reaction time, and hydrocarbon flow rate, were optimized. It was observed that the optimal surface area, thickness, and yield of the CNFs caused more adhesion of the fibers with the PP matrix, which enhanced the composite properties. Besides this, the effectiveness of reinforcement of fillers was fitted with a mathematical model obtaining good agreement between the experimental result and the theoretical prediction. By applying scanning electronic microscope (SEM), transmission electron microscope (TEM), and Raman spectroscopy, the surface morphology and structural information of the resultant CF-CNF were analyzed. Additionally, SEM images and a mechanical test of the composite with a proper layer of CNFs on the CF revealed not only a compactness effect but also the thickness and surface area roles of the CNF layers in improving the mechanical properties of the composites. PMID:28344263

Air pollution, cardiovascular endpoints and susceptibility by stress and material resources: a systematic review of the evidence.

PubMed

Fuller, Christina H; Feeser, Karla R; Sarnat, Jeremy A; O'Neill, Marie S

2017-06-14

Evidence shows that both the physical and social environments play a role in the development of cardiovascular disease. The purpose of this systematic review is two-fold: First, we summarize research from the past 12 years from the growing number of studies focused on effect modification of the relationships between air pollution and cardiovascular disease (CVD) outcomes by socioeconomic position (SEP) and; second, we identify research gaps throughout the published literature on this topic and opportunities for addressing these gaps in future study designs. We identified 30 articles that examined the modifying effects of either material resources or psychosocial stress (both related to SEP) on associations between short and long-term air pollution exposure and CVD endpoints. Although 18 articles identified at least one interaction between an air pollutant and material resource indicator, 11 others did not. Support for susceptibility to air pollution by psychosocial stress was weaker; however, only three articles tested this hypothesis. Further studies are warranted to investigate how air pollution and SEP together may influence CVD. We recommend that such research include thorough assessment of air pollution and SEP correlations, including spatial correlation; investigate air pollution indices or multi-pollutant models; use standardized metrics of SEP to enhance comparability across studies; and evaluate potentially susceptible populations.

Anxiety sensitivity in smokers with indicators of cardiovascular disease.

PubMed

Farris, Samantha G; Abrantes, Ana M

2017-09-01

There is growing recognition of the importance of understanding the nature of the associations between anxiety and cardiovascular disease (CVD), although limited research has examined mechanisms that may explain the anxiety-CVD link. Anxiety sensitivity (fear of anxiety-relevant somatic sensations) is a cognitive-affective risk factor implicated in the development of anxiety psychopathology and various behavioral risk factors for CVD, although has not been examined among individuals with CVD. Adult daily smokers (n = 619; 50.9% female; M age  = 44.0, SD = 13.67) completed an online survey that included the Anxiety Sensitivity Index-3 (ASI-3) and the Patient Health Questionnaire (PHQ). The presence of CVD was assessed via the presence of ≥1 of the following: heart attack, heart murmur, positive stress test, heart valve abnormality, angina, and heart failure. Smokers with CVD indicators (n = 66, 10.7%) had significantly higher scores on the ASI-3 (M = 33.5, SD = 22.15), relative to smokers without CVD (M = 22.0, SD = 17.92; Cohen's d = .57). Those with CVD were significantly more likely to have moderate or high anxiety sensitivity (66.7%) relative to those without CVD (49.4%). Physical and social concerns about the meaning of somatic sensations were common among smokers with CVD.

Predicting timing of clinical outcomes in patients with chronic kidney disease and severely decreased glomerular filtration rate.

PubMed

Grams, Morgan E; Sang, Yingying; Ballew, Shoshana H; Carrero, Juan Jesus; Djurdjev, Ognjenka; Heerspink, Hiddo J L; Ho, Kevin; Ito, Sadayoshi; Marks, Angharad; Naimark, David; Nash, Danielle M; Navaneethan, Sankar D; Sarnak, Mark; Stengel, Benedicte; Visseren, Frank L J; Wang, Angela Yee-Moon; Köttgen, Anna; Levey, Andrew S; Woodward, Mark; Eckardt, Kai-Uwe; Hemmelgarn, Brenda; Coresh, Josef

2018-06-01

Patients with chronic kidney disease and severely decreased glomerular filtration rate (GFR) are at high risk for kidney failure, cardiovascular disease (CVD) and death. Accurate estimates of risk and timing of these clinical outcomes could guide patient counseling and therapy. Therefore, we developed models using data of 264,296 individuals in 30 countries participating in the international Chronic Kidney Disease Prognosis Consortium with estimated GFR (eGFR)s under 30 ml/min/1.73m 2 . Median participant eGFR and urine albumin-to-creatinine ratio were 24 ml/min/1.73m 2 and 168 mg/g, respectively. Using competing-risk regression, random-effect meta-analysis, and Markov processes with Monte Carlo simulations, we developed two- and four-year models of the probability and timing of kidney failure requiring kidney replacement therapy (KRT), a non-fatal CVD event, and death according to age, sex, race, eGFR, albumin-to-creatinine ratio, systolic blood pressure, smoking status, diabetes mellitus, and history of CVD. Hypothetically applied to a 60-year-old white male with a history of CVD, a systolic blood pressure of 140 mmHg, an eGFR of 25 ml/min/1.73m 2 and a urine albumin-to-creatinine ratio of 1000 mg/g, the four-year model predicted a 17% chance of survival after KRT, a 17% chance of survival after a CVD event, a 4% chance of survival after both, and a 28% chance of death (9% as a first event, and 19% after another CVD event or KRT). Risk predictions for KRT showed good overall agreement with the published kidney failure risk equation, and both models were well calibrated with observed risk. Thus, commonly-measured clinical characteristics can predict the timing and occurrence of clinical outcomes in patients with severely decreased GFR. Copyright © 2018 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

The obesity paradox and incident cardiovascular disease: A population-based study

PubMed Central

Langa, Kenneth M.; Weir, David; Iwashyna, Theodore J.

2017-01-01

Background Prior work suggests that obesity may confer a survival advantage among persons with cardiovascular disease (CVD). This obesity “paradox” is frequently studied in the context of prevalent disease, a stage in the disease process when confounding from illness-related weight loss and selective survival are especially problematic. Our objective was to examine the association of obesity with mortality among persons with incident CVD, where biases are potentially reduced, and to compare these findings with those based on prevalent disease. Methods We used data from the Health and Retirement Study, an ongoing, nationally representative longitudinal survey of U.S. adults age 50 years and older initiated in 1992 and linked to Medicare claims. Cox proportional hazard models were used to estimate the association between weight status and mortality among persons with specific CVD diagnoses. CVD diagnoses were established by self-reported survey data as well as Medicare claims. Prevalent disease models used concurrent weight status, and incident disease models used pre-diagnosis weight status. Results We examined myocardial infarction, congestive heart failure, stroke, and ischemic heart disease. A strong and significant obesity paradox was consistently observed in prevalent disease models (hazard of death 18–36% lower for obese class I relative to normal weight), replicating prior findings. However, in incident disease models of the same conditions in the same dataset, there was no evidence of this survival benefit. Findings from models using survey- vs. claims-based diagnoses were largely consistent. Conclusion We observed an obesity paradox in prevalent CVD, replicating prior findings in a population-based sample with longer-term follow-up. In incident CVD, however, we did not find evidence of a survival advantage for obesity. Our findings do not offer support for reevaluating clinical and public health guidelines in pursuit of a potential obesity paradox. PMID:29216243

Friction and Wear of Ion-Beam-Deposited Diamondlike Carbon on Chemical-Vapor-Deposited, Fine-Grain Diamond

NASA Technical Reports Server (NTRS)

Miyoshi, Kazuhisa; Wu, Richard L. C.; Lanter, William C.

1996-01-01

Friction and wear behavior of ion-beam-deposited diamondlike carbon (DLC) films coated on chemical-vapor-deposited (CVD), fine-grain diamond coatings were examined in ultrahigh vacuum, dry nitrogen, and humid air environments. The DLC films were produced by the direct impact of an ion beam (composed of a 3:17 mixture of Ar and CH4) at ion energies of 1500 and 700 eV and an RF power of 99 W. Sliding friction experiments were conducted with hemispherical CVD diamond pins sliding on four different carbon-base coating systems: DLC films on CVD diamond; DLC films on silicon; as-deposited, fine-grain CVD diamond; and carbon-ion-implanted, fine-grain CVD diamond on silicon. Results indicate that in ultrahigh vacuum the ion-beam-deposited DLC films on fine-grain CVD diamond (similar to the ion-implanted CVD diamond) greatly decrease both the friction and wear of fine-grain CVD diamond films and provide solid lubrication. In dry nitrogen and in humid air, ion-beam-deposited DLC films on fine-grain CVD diamond films also had a low steady-state coefficient of friction and a low wear rate. These tribological performance benefits, coupled with a wider range of coating thicknesses, led to longer endurance life and improved wear resistance for the DLC deposited on fine-grain CVD diamond in comparison to the ion-implanted diamond films. Thus, DLC deposited on fine-grain CVD diamond films can be an effective wear-resistant, lubricating coating regardless of environment.

Crystal-proven Gout and Characteristic Gout Severity Factors are Associated with Cardiovascular Disease.

PubMed

Disveld, Iris J M; Fransen, Jaap; Rongen, Gerard A; Kienhorst, Laura B E; Zoakman, Sahel; Janssens, Hein J E M; Janssen, Matthijs

2018-04-15

Our aim was to examine the prevalence of cardiovascular disease (CVD) in patients with crystal-proven gout compared to arthritis controls. Further, we analyzed the association between characteristic gout severity factors and CVD to provide further support for a pathogenetic relationship between gout and CVD. Patients with arthritis referred for diagnosis were consecutively included in the Gout Arnhem-Liemers cohort. Joint fluid analysis was performed in all referred patients; controls were negative for crystals. Patients' characteristics and different manifestations of CVD and gout severity factors (disease duration, attack frequency, tophi, affected joints, high serum urate acid level, joint damage) were collected. Gout patients were compared with controls for the prevalence of CVD. In addition, the association between characteristic gout severity factors and presence of CVD was analyzed. Data from 700 gout patients and 276 controls were collected. CVD was present in 47% (95% CI 44%-51%) and 24% (95% CI 19%-29%) of gout patients and controls, respectively. Corrected for confounders, gout was still strongly associated with an increased prevalence of CVD compared to controls (OR 3.39, 95% CI 2.37-4.84). In patients with gout, disease duration ≥ 2 years, oligo- or polyarthritis, serum urate acid > 0.55 mmol/l at presentation, and joint damage were independently (p < 0.05) associated with prevalent CVD. Crystal-proven gout was strongly associated with an increased prevalence of CVD. In patients with gout, characteristic gout severity factors were associated with CVD.

Density of calcium in the ascending thoracic aorta and risk of incident cardiovascular disease events.

PubMed

Thomas, Isac C; McClelland, Robyn L; Michos, Erin D; Allison, Matthew A; Forbang, Nketi I; Longstreth, W T; Post, Wendy S; Wong, Nathan D; Budoff, Matthew J; Criqui, Michael H

2017-10-01

The volume and density of coronary artery calcium (CAC) both independently predict cardiovascular disease (CVD) beyond standard risk factors, with CAC density inversely associated with incident CVD after accounting for CAC volume. We tested the hypothesis that ascending thoracic aorta calcium (ATAC) volume and density predict incident CVD events independently of CAC. The Multi-Ethnic Study of Atherosclerosis (MESA) is a prospective cohort study of participants without clinical CVD at baseline. ATAC and CAC were measured from baseline cardiac computed tomography (CT). Cox regression models were used to estimate the associations of ATAC volume and density with incident coronary heart disease (CHD) events and CVD events, after adjustment for standard CVD risk factors and CAC volume and density. Among 6811 participants, 234 (3.4%) had prevalent ATAC and 3395 (49.8%) had prevalent CAC. Over 10.3 years, 355 CHD and 562 CVD events occurred. One-standard deviation higher ATAC density was associated with a lower risk of CHD (HR 0.48 [95% CI 0.29-0.79], p<0.01) and CVD (HR 0.56 [0.37-0.84], p<0.01) after full adjustment. ATAC volume was not associated with outcomes after full adjustment. ATAC was uncommon in a cohort free of clinical CVD at baseline. However, ATAC density was inversely associated with incident CHD and CVD after adjustment for CVD risk factors and CAC volume and density. Copyright © 2017 Elsevier B.V. All rights reserved.

Mortality from cardiovascular diseases in Bavi District, Vietnam.

PubMed

Minh, Hoang Van; Byass, Peter; Wall, Stig

2003-01-01

Like other developing countries, Vietnam is undergoing epidemiological transition, which is characterized by many changes in terms of morbidity and mortality patterns. The fact that cardiovascular diseases (CVD) are leading causes of death in hospitals in the whole country was ascertained from annual statistics. However, the magnitude of the burden of mortality from CVD at the community level remained unknown. The aims of the study were to outline CVD mortality during health transition in a rural community in the north of Vietnam and to examine associations between CVD mortality and the socioeconomic status of the population. Within an established demographic surveillance system (DSS), verbal autopsy (VA) was used to identify the burden of mortality from CVD. Cohort analysis was used in this study to measure associations between CVD mortality and socioeconomic determinants. CVD emerged as a leading cause of death in the study area, accounting for more than infectious and parasitic diseases combined. CVD killed many people among the most economically productive age group, both men and women, in all socioeconomic groups. Occupational status was shown to be significantly associated with CVD mortality. Already at this point in the epidemiological transition, there is evidence of a substantial burden of CVD in rural Vietnam. Although this study was not able to show trends, the current situation is a cause for concern in health policy and planning. Verbal autopsy methods and CVD risk factor evaluations will form important parts of future research agendas.

Saturated Fatty Acids and Cardiovascular Disease: Replacements for Saturated Fat to Reduce Cardiovascular Risk

PubMed Central

Briggs, Michelle A.; Petersen, Kristina S.; Kris-Etherton, Penny M.

2017-01-01

Dietary recommendations to decrease the risk of cardiovascular disease (CVD) have focused on reducing intake of saturated fatty acids (SFA) for more than 50 years. While the 2015–2020 Dietary Guidelines for Americans advise substituting both monounsaturated and polyunsaturated fatty acids for SFA, evidence supports other nutrient substitutions that will also reduce CVD risk. For example, replacing SFA with whole grains, but not refined carbohydrates, reduces CVD risk. Replacing SFA with protein, especially plant protein, may also reduce CVD risk. While dairy fat (milk, cheese) is associated with a slightly lower CVD risk compared to meat, dairy fat results in a significantly greater CVD risk relative to unsaturated fatty acids. As research continues, we will refine our understanding of dietary patterns associated with lower CVD risk. PMID:28635680

Process research of non-cz silicon material. Low cost solar array project, cell and module formation research area

NASA Technical Reports Server (NTRS)

1982-01-01

Liquid diffusion masks and liquid applied dopants to replace the CVD Silox masking and gaseous diffusion operations specified for forming junctions in the Westinghouse baseline process sequence for producing solar cells from dendritic web silicon were investigated.

Cardiovascular Disease is Associated with COPD Severity and Reduced Functional Status and Quality of Life

PubMed Central

Black-Shinn, Jennifer L.; Kinney, Gregory L.; Wise, Anastasia L.; Regan, Elizabeth A.; Make, Barry; Krantz, Mori J.; Barr, R. Graham; Murphy, James R.; Lynch, David; Silverman, Edwin K.; Crapo, James D.; Hokanson, John E.

2015-01-01

Introduction Smoking is a major risk factor for both cardiovascular disease (CVD) and chronic obstructive pulmonary disease (COPD). More individuals with COPD die from CVD than respiratory causes and the risk of developing CVD appears to be independent of smoking burden. Although CVD is a common comorbid condition within COPD, the nature of its relationships to COPD affection status and severity, and functional status is not well understood. Methods The first 2,500 members of the COPDGene cohort were evaluated. Subjects were current and former smokers with a minimum 10 pack year history of cigarette smoking. COPD was defined by spirometry as an FEV1/FVC < lower limit of normal (LLN) with further identification of severity by FEV1 percent of predicted (GOLD stages 2, 3, and 4) for the main analysis. The presence of physician-diagnosed self-reported CVD was determined from a medical history questionnaire administered by a trained staff member. Results A total of 384 (15%) had pre-existing CVD. Self-reported CVD was independently related to COPD (Odds Ratio=1.61, 95% CI=1.18–2.20, p=0.01) after adjustment for covariates with CHF having the greatest association with COPD. Within subjects with COPD, pre-existing self-reported CVD placed subjects at greater risk of hospitalization due to exacerbation, higher BODE index, and greater St. George’s questionnaire score. The presence of self-reported CVD was associated with a shorter six-minute walk distance in those with COPD (p<0.05). Conclusions Self-reported CVD was independently related to COPD with presence of both self-reported CVD and COPD associated with a markedly reduced functional status and reduced quality of life. Identification of CVD in those with COPD is an important consideration in determining functional status. PMID:24831864

Racial disparities in age at time of cardiovascular events and cardiovascular-related death in patients with systemic lupus erythematosus.

PubMed

Scalzi, Lisabeth V; Hollenbeak, Christopher S; Wang, Li

2010-09-01

To determine whether racial disparities exist with regard to the age at which patients with systemic lupus erythematosus (SLE) experience cardiovascular disease (CVD) and CVD-associated death. Using the 2003-2006 Nationwide Inpatient Sample, we calculated the age difference between patients with SLE and their race- and sex-matched controls at the time of hospitalization for a cardiovascular event and for CVD-associated death. In addition, we calculated the age difference between white patients with SLE and sex-matched controls for each minority group for the same outcomes. The mean age difference between women with and those without SLE at the time of admission for a CVD event was 10.5 years. All age differences between women with SLE (n = 3,627) and women without SLE admitted for CVD were significant (P < 0.0001). Among different racial groups with SLE, black women were the youngest to be admitted with CVD (53.9 years) and to have a CVD-associated in-hospital death (52.8 years; n = 218). Black women with SLE were 19.8 years younger than race- and sex-matched controls at the time of CVD-associated death. Admission trends for CVD were reversed for black women, such that the highest proportions of these patients were admitted before age 55 years, and then the proportions steadily decreased across age categories. Among the 805 men with SLE who were admitted with a CVD event, those who were black or Hispanic were youngest. There are significant racial disparities with regard to age at the time of hospital admission for CVD events and CVD-related hospitalization resulting in death in patients with SLE.

Perceived and actual risk of cardiovascular disease in patients with rheumatoid arthritis in Korea: A cross-sectional study.

PubMed

Boo, Sunjoo; Froelicher, Erika S; Yun, Ju-Hui; Kim, Ye-Won; Jung, Ju-Yang; Suh, Chang-Hee

2016-10-01

The purposes of this study were to compare the perceived and actual 10-year risk for cardiovascular disease (CVD) and to evaluate the influence of cardiovascular risk factors on perceived CVD risk in patients with rheumatoid arthritis (RA) in Korea. Additionally, the attainment of CVD prevention guideline goals by 3 levels of CVD risk (low, moderate, and high) was presented.For this cross-sectional study, data were collected from 208 patients with RA. Actual CVD risk was estimated with the Systematic Coronary Risk Evaluation (SCORE), and goal attainment was assessed based on the European League Against Rheumatism guidelines. Actual CVD risk and perceived risk were compared with cross-tabulation. Chi-square tests were used to evaluate differences in cardiovascular risk factors by perceived risk. Levels of goal attainment were presented in percentages.Among patients with RA, 13.9% were identified as being at high risk for CVD, whereas 39.9% were at moderate risk, and 46.2% were at low risk. The majority of those at high risk (96.6%) underestimated their risk for CVD. The use of antihypertensive or lipid-lowering medications and having a parental history of CVD significantly increased the likelihood that subjects with RA would perceive themselves as being at high risk for CVD. Diabetes, smoking, physical inactivity, and obesity did not affect perceived risk. A substantial proportion of the subjects with RA did not meet the prevention guideline goals.Patients with RA who are at increased risk of developing CVD must be managed as soon as possible to attain the guideline goals and, accordingly, lower their risk of future CVD.

Effect of gender on awareness of cardiovascular risk factors, preventive action taken, and barriers to cardiovascular health in a group of Austrian subjects.

PubMed

Haidinger, Teresa; Zweimüller, Martin; Stütz, Lena; Demir, Dondue; Kaider, Alexandra; Strametz-Juranek, Jeanette

2012-04-01

The incidence of cardiovascular disease (CVD) is increasing in industrialized countries. Preventive action is an important factor in minimizing CVD-associated morbidity and mortality. However, it is not known whether gender differences affect CVD or risk factor awareness influencing self-assessment of personal risk and preventive action. This study was performed to assess individual CVD and risk factor awareness, preventive action taken, and barriers to cardiovascular health. The study included 573 women and 336 men, randomly chosen to complete an anonymous questionnaire to assess individual CVD and risk factor awareness, preventive action taken, and barriers to cardiovascular health. The data were analyzed using SAS software. Cardiovascular disease was identified in 75% of patients, in both sexes, as the leading cause of death; however, both groups showed significant lack of knowledge about CVD risk factors. Type 2 diabetes was identified correctly in only 27.5%. Preventive action was linked more often to family members in 66.5% of women and 62.8% of men. The primary barrier to cardiovascular health in adults was incorrect assessment of personal CVD risk. More than half of female respondents (56.4%) and male respondents (52.7%) underestimated their risk of CVD. Knowledge about risk factors for CVD needs to be improved in members of both sexes. Because women, in particular, have difficulty in correctly assessing their personal CVD risk, future education programs are warranted to inform both women and men about CVD and its risk factors, thereby helping them to correctly assess their individual risk. However, greater effort is needed to inform men, compared with women, about the various ways in which to prevent CVD and to motivate them to take preventive action. Copyright © 2012 Elsevier HS Journals, Inc. All rights reserved.

Rheumatoid Arthritis, Anti-CCP Positivity, and Cardiovascular Disease Risk in the Women’s Health Initiative

PubMed Central

Mackey, Rachel H.; Kuller, Lewis H.; Deane, Kevin D.; Walitt, Brian T.; Chang, Yuefang F.; Holers, V. Michael; Robinson, William H.; Tracy, Russell P.; Hlatky, Mark A.; Eaton, Charles; Liu, Simin; Freiberg, Matthew S.; Talabi, Mehret Birru; Schelbert, Erik B.; Moreland, Larry W.

2015-01-01

Objective This report evaluates incidence of cardiovascular disease (CVD) morbidity and mortality over 10 years among the >160,000 postmenopausal women in the Women’s Health Initiative (WHI) in relation to self-reported RA, disease modifying anti-rheumatic drugs (DMARD) use, anti-CCP+, RF+, CVD risk factors, joint pain, and inflammation (white blood cell (WBC) count and IL-6.) Methods Anti-CCP and RF were measured on a sample (n=9,988) of WHI participants with self-reported RA. RA was classified as self-reported RA plus anti-CCP+ positivity and/or use of DMARDs. Self-reported RA that was both anti-CCP− and DMARD− was classified as “unverified RA.” Results Age-adjusted rates of coronary heart disease (CHD), stroke, CVD, fatal CVD and total mortality were higher for women with RA vs. no RA, with multivariable-adjusted HR(95%CI) of 1.46(1.17, 1.83) for CHD, and 2.55(1.86, 3.51) for fatal CVD. Within RA, anti-CCP+ and RF+ were not significantly associated with higher risk of any outcomes, despite slightly higher risk of fatal CVD and death for anti-CCP+ vs. anti-CCP− RA. Joint pain severity and CVD risk factors were strongly associated with CVD risk, even for women with no RA. CVD incidence was increased for RA vs. no RA at almost all risk factor levels, except low levels of joint pain or inflammation. Within RA, inflammation was more strongly associated with fatal CVD and total mortality than CHD or CVD. Conclusion Among postmenopausal women, RA was associated with 1.5-2.5 higher CVD risk, strongly associated with CV risk factors, joint pain severity, and inflammation, but similar for anti-CCP+ and RF+. Clinical Trial Registration clinicaltrials.gov identifier: NCT00000611 PMID:25988241

Australian community pharmacists' awareness and practice in supporting secondary prevention of cardiovascular disease.

PubMed

Puspitasari, Hanni Prihhastuti; Aslani, Parisa; Krass, Ines

2013-12-01

Pharmacists are well placed to identify, prevent and resolve medicine related problems as well as monitor the effectiveness of treatments in cardiovascular disease (CVD). Pharmacists' interventions in CVD secondary prevention have been shown to improve outcomes for clients with established CVD. To explore the scope of pharmacists' activities in supporting CVD secondary prevention. Community pharmacies in New South Wales, Australia. Twenty-one in-depth, semi-structured interviews with a range of community pharmacists were conducted. All interviews were audio-recorded and transcribed ad verbatim. Data were analyzed using a 'grounded-theory' approach by applying methods of constant comparison. Community pharmacists' awareness and current practice in supporting secondary prevention of CVD. Four key themes identified included 'awareness', 'patient counselling', 'patient monitoring', and 'perceptions of the role of pharmacists in CVD secondary prevention'. The pharmacists demonstrated a moderate understanding of CVD secondary prevention. There was considerable variability in the scope of practice among the participants, ranging from counselling only about medicines to providing continuity of care. A minority of pharmacists who had negative beliefs about their roles in CVD secondary prevention offered limited support to their clients. The majority of pharmacists, however, believed that they have an important role to play in supporting clients with established CVD. Community pharmacists in Australia make a contribution to the care of clients with established CVD despite the gap in their knowledge and understanding of CVD secondary prevention. The scope of practice in CVD secondary prevention ranged from only counselling about medicines to offering continuity of care. The extent of pharmacists' involvement in offering disease management appears to be influenced by their beliefs regarding what is required within their scope of practice.

Intake of grape procyanidins during gestation and lactation impairs reverse cholesterol transport and increases atherogenic risk indexes in adult offspring.

PubMed

Del Bas, Josep Maria; Crescenti, Anna; Arola-Arnal, Anna; Oms-Oliu, Gemma; Arola, Lluís; Caimari, Antoni

2015-12-01

Cardiovascular disease (CVD) is one of the most prevalent noncommunicable diseases in humans. Different studies have identified dietary procyanidins as bioactive compounds with beneficial properties against CVD by improving lipid homeostasis, among other mechanisms. The aim of this work was to assess whether grape seed procyanidin consumption at a physiological dose during the perinatal period could influence the CVD risk of the offspring. Wistar rat dams were treated with a grape seed procyanidin extract (GSPE; 25mg/kg of body weight per day) or vehicle during gestation and lactation. The adult male offspring of GSPE-treated dams presented decreased high-density lipoprotein cholesterol (HDL-C) levels, increased total cholesterol-to-HDL-C ratios and an exacerbated fasting triglyceride-to-HDL-C ratios (atherogenic index of plasma) compared to the control group. Impaired reverse cholesterol transport (RCT) was evidenced by the accumulation of cholesterol in skeletal muscle and by decreased fecal excretion of cholesterol and bile acids, which was consistent with the observed mRNA down-regulation of the rate-limiting enzyme in the hepatic bile acid synthesis pathway Cyp7A1. Conversely, GSPE programming also resulted in up-regulated gene expression of different key components of the RCT process, such as hepatic Npc1, Abcg1, Abca1, Lxra, Srebp2, Lcat, Scarb1 and Pltp, and the repression of microRNA miR-33a expression, a key negative controller of hepatic RCT at the gene expression level. Our results show that maternal intake of grape procyanidins during the perinatal period impacts different components of the RCT process, resulting in increased CVD risk in the adult offspring. Copyright © 2015 Elsevier Inc. All rights reserved.

Identification and comparative analyses of myocardial miRNAs involved in the fetal response to maternal obesity.

PubMed

Maloyan, Alina; Muralimanoharan, Sribalasubashini; Huffman, Steven; Cox, Laura A; Nathanielsz, Peter W; Myatt, Leslie; Nijland, Mark J

2013-10-01

Human and animal studies show that suboptimal intrauterine environments lead to fetal programming, predisposing offspring to disease in later life. Maternal obesity has been shown to program offspring for cardiovascular disease (CVD), diabetes, and obesity. MicroRNAs (miRNAs) are small, noncoding RNA molecules that act as key regulators of numerous cellular processes. Compelling evidence links miRNAs to the control of cardiac development and etiology of cardiac pathology; however, little is known about their role in the fetal cardiac response to maternal obesity. Our aim was to sequence and profile the cardiac miRNAs that are dysregulated in the hearts of baboon fetuses born to high fat/high fructose-diet (HFD) fed mothers for comparison with fetal hearts from mothers eating a regular diet. Eighty miRNAs were differentially expressed. Of those, 55 miRNAs were upregulated and 25 downregulated with HFD. Twenty-two miRNAs were mapped to human; 14 of these miRNAs were previously reported to be dysregulated in experimental or human CVD. We used an Ingenuity Pathway Analysis to integrate miRNA profiling and bioinformatics predictions to determine miRNA-regulated processes and genes potentially involved in fetal programming. We found a correlation between miRNA expression and putative gene targets involved in developmental disorders and CVD. Cellular death, growth, and proliferation were the most affected cellular functions in response to maternal obesity. Thus, the current study reveals significant alterations in cardiac miRNA expression in the fetus of obese baboons. The epigenetic modifications caused by adverse prenatal environment may represent one of the mechanisms underlying fetal programming of CVD.

N-terminal pro-brain-type natriuretic peptide (NT-pro-BNP) and mortality risk in early inflammatory polyarthritis: results from the Norfolk Arthritis Registry (NOAR)

PubMed Central

Mirjafari, Hoda; Welsh, Paul; Verstappen, Suzanne M M; Wilson, Paddy; Marshall, Tarnya; Edlin, Helena; Bunn, Diane; Chipping, Jacqueline; Lunt, Mark; Symmons, Deborah P M; Sattar, Naveed; Bruce, Ian N

2014-01-01

Background We measured N-terminal pro-brain natriuretic peptide (NT-pro-BNP), a marker of cardiac dysfunction, in an inception cohort with early inflammatory polyarthritis (IP) and assessed its association with disease phenotype, cardiovascular disease (CVD), all-cause and CVD related mortality. Methods Subjects with early IP were recruited to the Norfolk Arthritis Register from January 2000 to December 2008 and followed up to death or until March 2010 including any data from the national death register. The associations of baseline NT-pro-BNP with IP related factors and CVD were assessed by linear regression. Cox proportional hazards models examined the independent association of baseline NT-pro-BNP with all-cause and CVD mortality. Results We studied 960 early IP subjects; 163 (17%) had prior CVD. 373 (39%) patients had a baseline NT-pro-BNP levels ≥100 pg/ml. NT-pro-BNP was associated with age, female gender, HAQ score, CRP, current smoking, history of hypertension, prior CVD and the presence of carotid plaque. 92 (10%) IP subjects died including 31 (3%) from CVD. In an age and gender adjusted analysis, having a raised NT-pro-BNP level (≥100 pg/ml) was associated with both all-cause and CVD mortality (adjusted HR (95% CI) 2.36 (1.42 to 3.94) and 3.40 (1.28 to 9.03), respectively). These findings were robust to adjustment for conventional CVD risk factors and prevalent CVD. Conclusions In early IP patients, elevated NT-pro-BNP is related to HAQ and CRP and predicts all-cause and CVD mortality independently of conventional CVD risk factors. Further study is required to identify whether NT-pro-BNP may be clinically useful in targeting intensive interventions to IP patients at greatest risk of CVD. PMID:23511225

Validation of a model to investigate the effects of modifying cardiovascular disease (CVD) risk factors on the burden of CVD: the rotterdam ischemic heart disease and stroke computer simulation (RISC) model.

PubMed

van Kempen, Bob J H; Ferket, Bart S; Hofman, Albert; Steyerberg, Ewout W; Colkesen, Ersen B; Boekholdt, S Matthijs; Wareham, Nicholas J; Khaw, Kay-Tee; Hunink, M G Myriam

2012-12-06

We developed a Monte Carlo Markov model designed to investigate the effects of modifying cardiovascular disease (CVD) risk factors on the burden of CVD. Internal, predictive, and external validity of the model have not yet been established. The Rotterdam Ischemic Heart Disease and Stroke Computer Simulation (RISC) model was developed using data covering 5 years of follow-up from the Rotterdam Study. To prove 1) internal and 2) predictive validity, the incidences of coronary heart disease (CHD), stroke, CVD death, and non-CVD death simulated by the model over a 13-year period were compared with those recorded for 3,478 participants in the Rotterdam Study with at least 13 years of follow-up. 3) External validity was verified using 10 years of follow-up data from the European Prospective Investigation of Cancer (EPIC)-Norfolk study of 25,492 participants, for whom CVD and non-CVD mortality was compared. At year 5, the observed incidences (with simulated incidences in brackets) of CHD, stroke, and CVD and non-CVD mortality for the 3,478 Rotterdam Study participants were 5.30% (4.68%), 3.60% (3.23%), 4.70% (4.80%), and 7.50% (7.96%), respectively. At year 13, these percentages were 10.60% (10.91%), 9.90% (9.13%), 14.20% (15.12%), and 24.30% (23.42%). After recalibrating the model for the EPIC-Norfolk population, the 10-year observed (simulated) incidences of CVD and non-CVD mortality were 3.70% (4.95%) and 6.50% (6.29%). All observed incidences fell well within the 95% credibility intervals of the simulated incidences. We have confirmed the internal, predictive, and external validity of the RISC model. These findings provide a basis for analyzing the effects of modifying cardiovascular disease risk factors on the burden of CVD with the RISC model.

Exercise and cardiovascular outcomes by hypertensive status: NHANES I epidemiological follow-up study, 1971-1992.

PubMed

Fang, Jing; Wylie-Rosett, Judith; Alderman, Michael H

2005-06-01

A favorable effect of exercise on cardiovascular longevity has been repeatedly demonstrated in the general population. The association of exercise and cardiovascular disease (CVD) outcome among persons with different blood pressure (BP) status is less well known. We examined the epidemiologic follow-up of the First National Health and Nutrition Examination Survey (NHANES I) (1971-1992). Of 14,407 participants, 9791 subjects aged 25 to 74 years met inclusion criteria. All cause, CVD, and non-CVD mortality rates, as well as CVD incidence rates were determined. The associations of levels of exercise and outcomes by BP status were examined. Age- and gender-adjusted rates, as well as Cox proportional hazard models were determined. During 17 years of follow-up, there were 3069 deaths, 1465 of which were CVD. In addition, 2808 subjects had incident CVD events. Overall, CVD incidence and mortality rates increased as BP rose. The association of exercise with CVD events differed by BP status (normal, prehypertension, and hypertension). Age- and gender-adjusted CVD mortality rate per 1000 person-years for least, moderate, and most exercise were 5.0, 3.6, and 2.4 among normotensive subjects (P > .05), 6.3, 4.7, and 5.2 among prehypertensive subjects (P > .05), and 11.8, 9.8, and 8.7 among hypertensive subjects (P < .01), respectively. In fact, exercise was a significant independent predictor of reduced CVD event only among hypertensive subjects, after adjusting for other CVD risk factors. Among prehypertensive and normotensive subjects, where events were fewer, those who exercise more vigorously also had lower mortality, but these differences did not reach statistical significance. This study, consistent with previous observational data, demonstrates that increased exercise is associated with decreased CVD event. Interestingly, this effect is most robust among hypertensive subjects, whereas for prehypertensive and normotensive subjects, a significant benefit of exercise on CVD outcome, perhaps because of lack of power, was not found.

Plasma and blood viscosity in the prediction of cardiovascular disease and mortality in the Scottish Heart Health Extended Cohort Study.

PubMed

Peters, Sanne Ae; Woodward, Mark; Rumley, Ann; Tunstall-Pedoe, Hugh D; Lowe, Gordon DO

2017-01-01

Background There is increasing evidence that blood viscosity and its major determinants (haematocrit and plasma viscosity) are associated with increased risks of cardiovascular disease (CVD) and premature mortality; however, their predictive value for CVD and mortality is not clear. Methods We prospectively assessed the added predictive value of plasma viscosity and whole blood viscosity and haematocrit in 3386 men and women aged 30-74 years participating in the Scottish Heart Health Extended Cohort study. Results Over a median follow-up of 17 years, 819 CVD events and 778 deaths were recorded. Hazard ratios (95% confidence intervals) for a 1 SD increase in plasma viscosity, adjusted for major CVD risk factors, were 1.12 (1.04-1.20) for CVD and 1.20 (1.12-1.29) for mortality. These remained significant after further adjustment for plasma fibrinogen: 1.09 (1.01-1.18) and 1.13 (1.04-1.22). The corresponding results for blood viscosity were 0.99 (0.90, 1.09) for CVD, and 1.11 (1.01, 1.22) for total mortality after adjustment for major CVD risk factors; and 0.97 (0.88, 1.08) and 1.06 (0.96, 1.18) after further adjustment for fibrinogen. Haematocrit showed similar associations to blood viscosity. When added to classical CVD risk factors, plasma viscosity improved the discrimination of CVD and mortality by 2.4% (0.7-4.4%) and 4.1% (2.0-6.5%). Conclusions Although plasma and blood viscosity may have a role in the pathogenesis of CVD and mortality, much of their association with CVD and mortality is due to the mutual effects of major CVD risk factors. However, plasma viscosity adds to the discrimination of CVD and mortality and might be considered for inclusion in multivariable risk scores.

Global progress in prevention of cardiovascular disease

PubMed Central

2017-01-01

Although there is measurable global progress in prevention of cardiovascular disease (CVD), it has been highly uneven and inadequate, particularly in low- and middle-income countries. Voluntary global targets have helped to galvanize attention, resources and accountability on tobacco use, harmful use of alcohol, unhealthy diet and physical inactivity which are the major behavioural drivers of CVD. Many obstacles and challenges continue to impede the progress of cardiovascular prevention. The inclusion of noncommunicable diseases (NCDs) in the sustainable development agenda as a specific target, offers an unprecedented opportunity to further advance the global progress of cardiovascular prevention. In order to seize this opportunity, a paradigm shift is required in the way key challenges to cardiovascular prevention are addressed. Such an approach must provide leadership for intersectoral policy coherence, identify effective means of tackling commercial determinants of behavioural risk factors, use rights based arguments, enhance public engagement and ensure accountability. PMID:28529920

Controlling the ripple density and heights: a new way to improve the electrical performance of CVD-grown graphene.

PubMed

Park, Won-Hwa; Jo, Insu; Hong, Byung Hee; Cheong, Hyeonsik

2016-05-14

We report a new way to enhance the electrical performances of large area CVD-grown graphene through controlling the ripple density and heights after transfer onto SiO2/Si substrates by employing different cooling rates during fabrication. We find that graphene films prepared with a high cooling rate have reduced ripple density and heights and improved electrical characteristics such as higher electron/hole mobilities as well as reduced sheet resistance. The corresponding Raman analysis also shows a significant decrease of the defects when a higher cooling rate is employed. We suggest a model that explains the improved morphology of the graphene film obtained with higher cooling rates. From these points of view, we can suggest a new pathway toward a relatively lower density and heights of ripples in order to reduce the flexural phonon-electron scattering effect, leading to higher lateral carrier mobilities.

EDC-mediated DNA attachment to nanocrystalline CVD diamond films.

PubMed

Christiaens, P; Vermeeren, V; Wenmackers, S; Daenen, M; Haenen, K; Nesládek, M; vandeVen, M; Ameloot, M; Michiels, L; Wagner, P

2006-08-15

Chemical vapour deposited (CVD) diamond is a very promising material for biosensor fabrication owing both to its chemical inertness and the ability to make it electrical semiconducting that allows for connection with integrated circuits. For biosensor construction, a biochemical method to immobilize nucleic acids to a diamond surface has been developed. Nanocrystalline diamond is grown using microwave plasma-enhanced chemical vapour deposition (MPECVD). After hydrogenation of the surface, 10-undecenoic acid, an omega-unsaturated fatty acid, is tethered by 254 nm photochemical attachment. This is followed by 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide (EDC)-mediated attachment of amino (NH(2))-modified dsDNA. The functionality of the covalently bound dsDNA molecules is confirmed by fluorescence measurements, PCR and gel electrophoresis during 35 denaturation and rehybridisation steps. The linking method after the fatty acid attachment can easily be applied to other biomolecules like antibodies and enzymes.

Simulating Colour Vision Deficiency from a Spectral Image.

PubMed

Shrestha, Raju

2016-01-01

People with colour vision deficiency (CVD) have difficulty seeing full colour contrast and can miss some of the features in a scene. As a part of universal design, researcher have been working on how to modify and enhance the colour of images in order to make them see the scene with good contrast. For this, it is important to know how the original colour image is seen by different individuals with CVD. This paper proposes a methodology to simulate accurate colour deficient images from a spectral image using cone sensitivity of different cases of deficiency. As the method enables generation of accurate colour deficient image, the methodology is believed to help better understand the limitations of colour vision deficiency and that in turn leads to the design and development of more effective imaging technologies for better and wider accessibility in the context of universal design.

Risk scoring for the primary prevention of cardiovascular disease.

PubMed

Karmali, Kunal N; Persell, Stephen D; Perel, Pablo; Lloyd-Jones, Donald M; Berendsen, Mark A; Huffman, Mark D

2017-03-14

The current paradigm for cardiovascular disease (CVD) emphasises absolute risk assessment to guide treatment decisions in primary prevention. Although the derivation and validation of multivariable risk assessment tools, or CVD risk scores, have attracted considerable attention, their effect on clinical outcomes is uncertain. To assess the effects of evaluating and providing CVD risk scores in adults without prevalent CVD on cardiovascular outcomes, risk factor levels, preventive medication prescribing, and health behaviours. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library (2016, Issue 2), MEDLINE Ovid (1946 to March week 1 2016), Embase (embase.com) (1974 to 15 March 2016), and Conference Proceedings Citation Index-Science (CPCI-S) (1990 to 15 March 2016). We imposed no language restrictions. We searched clinical trial registers in March 2016 and handsearched reference lists of primary studies to identify additional reports. We included randomised and quasi-randomised trials comparing the systematic provision of CVD risk scores by a clinician, healthcare professional, or healthcare system compared with usual care (i.e. no systematic provision of CVD risk scores) in adults without CVD. Three review authors independently selected studies, extracted data, and evaluated study quality. We used the Cochrane 'Risk of bias' tool to assess study limitations. The primary outcomes were: CVD events, change in CVD risk factor levels (total cholesterol, systolic blood pressure, and multivariable CVD risk), and adverse events. Secondary outcomes included: lipid-lowering and antihypertensive medication prescribing in higher-risk people. We calculated risk ratios (RR) for dichotomous data and mean differences (MD) or standardised mean differences (SMD) for continuous data using 95% confidence intervals. We used a fixed-effects model when heterogeneity (I²) was at least 50% and a random-effects model for substantial heterogeneity (I² > 50%). We evaluated the quality of evidence using the GRADE framework. We identified 41 randomised controlled trials (RCTs) involving 194,035 participants from 6422 reports. We assessed studies as having high or unclear risk of bias across multiple domains. Low-quality evidence evidence suggests that providing CVD risk scores may have little or no effect on CVD events compared with usual care (5.4% versus 5.3%; RR 1.01, 95% confidence interval (CI) 0.95 to 1.08; I² = 25%; 3 trials, N = 99,070). Providing CVD risk scores may reduce CVD risk factor levels by a small amount compared with usual care. Providing CVD risk scores reduced total cholesterol (MD -0.10 mmol/L, 95% CI -0.20 to 0.00; I² = 94%; 12 trials, N = 20,437, low-quality evidence), systolic blood pressure (MD -2.77 mmHg, 95% CI -4.16 to -1.38; I² = 93%; 16 trials, N = 32,954, low-quality evidence), and multivariable CVD risk (SMD -0.21, 95% CI -0.39 to -0.02; I² = 94%; 9 trials, N = 9549, low-quality evidence). Providing CVD risk scores may reduce adverse events compared with usual care, but results were imprecise (1.9% versus 2.7%; RR 0.72, 95% CI 0.49 to 1.04; I² = 0%; 4 trials, N = 4630, low-quality evidence). Compared with usual care, providing CVD risk scores may increase new or intensified lipid-lowering medications (15.7% versus 10.7%; RR 1.47, 95% CI 1.15 to 1.87; I² = 40%; 11 trials, N = 14,175, low-quality evidence) and increase new or increased antihypertensive medications (17.2% versus 11.4%; RR 1.51, 95% CI 1.08 to 2.11; I² = 53%; 8 trials, N = 13,255, low-quality evidence). There is uncertainty whether current strategies for providing CVD risk scores affect CVD events. Providing CVD risk scores may slightly reduce CVD risk factor levels and may increase preventive medication prescribing in higher-risk people without evidence of harm. There were multiple study limitations in the identified studies and substantial heterogeneity in the interventions, outcomes, and analyses, so readers should interpret results with caution. New models for implementing and evaluating CVD risk scores in adequately powered studies are needed to define the role of applying CVD risk scores in primary CVD prevention.

Fish consumption and its motives in households with versus without self-reported medical history of CVD: A consumer survey from five European countries

PubMed Central

Pieniak, Zuzanna; Verbeke, Wim; Perez-Cueto, Federico; Brunsø, Karen; De Henauw, Stefaan

2008-01-01

Background The purpose of this study was to explore the cross-cultural differences in the frequency of fish intake and in motivations for fish consumption between people from households with (CVD+) or without (CVD-) medical history of cardiovascular disease, using data obtained in five European countries. Methods A cross-sectional consumer survey was carried out in November-December 2004 with representative household samples from Belgium, the Netherlands, Denmark, Poland and Spain. The sample consisted of 4,786 respondents, aged 18–84 and who were responsible for food purchasing and cooking in the household. Results Individuals from households in the CVD+ group consumed fish more frequently in Belgium and in Denmark as compared to those in the CVD- group. The consumption of fatty fish, which is the main sources of omega-3 PUFA associated with prevention of cardiovascular diseases, was on the same level for the two CVD groups in the majority of the countries, except in Belgium where CVD+ subjects reported to eat fatty fish significantly more frequently than CVD- subjects. All respondents perceived fish as a very healthy and nutritious food product. Only Danish consumers reported a higher subjective and objective knowledge related to nutrition issues about fish. In the other countries, objective knowledge about fish was on a low level, similar for CVD+ as for CVD- subjects, despite a higher claimed use of medical information sources about fish among CVD+ subjects. Conclusion Although a number of differences between CVD- and CVD+ subjects with respect to their frequency of fish intake are uncovered, the findings suggest that fish consumption traditions and habits – rather than a medical history of CVD – account for large differences between the countries, particularly in fatty fish consumption. This study exemplifies the need for nutrition education and more effective communication about fish, not only to the people facing chronic diseases, but also to the broader public. European consumers are convinced that eating fish is healthy, but particular emphasis should be made on communicating benefits especially from fatty fish consumption. PMID:18783593

Sex and family history of cardiovascular disease influence heart rate variability during stress among healthy adults.

PubMed

Emery, Charles F; Stoney, Catherine M; Thayer, Julian F; Williams, DeWayne; Bodine, Andrew

2018-07-01

Studies of sex differences in heart rate variability (HRV) typically have not accounted for the influence of family history (FH) of cardiovascular disease (CVD). This study evaluated sex differences in HRV response to speech stress among men and women (age range 30-49 years) with and without a documented FH of CVD. Participants were 77 adults (mean age = 39.8 ± 6.2 years; range: 30-49 years; 52% female) with positive FH (FH+, n = 32) and negative FH (FH-, n = 45) of CVD, verified with relatives of participants. Cardiac activity for all participants was recorded via electrocardiogram during a standardized speech stress task with three phases: 5-minute rest, 5-minute speech, and 5-minute recovery. Outcomes included time domain and frequency domain indicators of HRV and heart rate (HR) at rest and during stress. Data were analyzed with repeated measures analysis of variance, with sex and FH as between subject variables and time/phase as a within subject variable. Women exhibited higher HR than did men and greater HR reactivity in response to the speech stress. However, women also exhibited greater HRV in both the time and frequency domains. FH+ women generally exhibited elevated HRV, despite the elevated risk of CVD associated with FH+. Although women participants exhibited higher HR at rest and during stress, women (both FH+ and FH-) also exhibited elevated HRV reactivity, reflecting greater autonomic control. Thus, enhanced autonomic function observed in prior studies of HRV among women is also evident among FH+ women during a standardized stress task. Copyright © 2018 Elsevier Inc. All rights reserved.

A diet rich in high-glucoraphanin broccoli interacts with genotype to reduce discordance in plasma metabolite profiles by modulating mitochondrial function123

PubMed Central

Armah, Charlotte N; Traka, Maria H; Dainty, Jack R; Defernez, Marianne; Janssens, Astrid; Leung, Wing; Doleman, Joanne F; Potter, John F

2013-01-01

Background: Observational and experimental studies suggest that diets rich in cruciferous vegetables and glucosinolates may reduce the risk of cancer and cardiovascular disease (CVD). Objective: We tested the hypothesis that a 12-wk dietary intervention with high-glucoraphanin (HG) broccoli would modify biomarkers of CVD risk and plasma metabolite profiles to a greater extent than interventions with standard broccoli or peas. Design: Subjects were randomly assigned to consume 400 g standard broccoli, 400 g HG broccoli, or 400 g peas each week for 12 wk, with no other dietary restrictions. Biomarkers of CVD risk and 347 plasma metabolites were quantified before and after the intervention. Results: No significant differences in the effects of the diets on biomarkers of CVD risk were found. Multivariate analyses of plasma metabolites identified 2 discrete phenotypic responses to diet in individuals within the HG broccoli arm, differentiated by single nucleotide polymorphisms associated with the PAPOLG gene. Univariate analysis showed effects of sex (P < 0.001), PAPOLG genotype (P < 0.001), and PAPOLG genotype × diet (P < 0.001) on the plasma metabolic profile. In the HG broccoli arm, the consequence of the intervention was to reduce variation in lipid and amino acid metabolites, tricarboxylic acid (TCA) cycle intermediates, and acylcarnitines between the 2 PAPOLG genotypes. Conclusions: The metabolic changes observed with the HG broccoli diet are consistent with a rebalancing of anaplerotic and cataplerotic reactions and enhanced integration of fatty acid β-oxidation with TCA cycle activity. These modifications may contribute to the reduction in cancer risk associated with diets that are rich in cruciferous vegetables. This trial was registered at clinicaltrials.gov as NCT01114399. PMID:23964055

Development and Evaluation of Die Materials for Use in the Growth of Silicon Ribbons by the Inverted Ribbon Growth Process. Task 2: LSSA Project

NASA Technical Reports Server (NTRS)

Duffy, M. T.; Berkman, S.; Moss, H. I.; Cullen, G. W.

1978-01-01

Several ribbon growth experiments were performed from V-shaped dies coated with CVD Si3N4. The most significant result was the ability to perform five consecutive growth runs from the same die without mechanical degradation of the die through temperature cycling. The die was made from vitreous carbon coated with CVD Si3N4. Silicon oxynitride, Si2N2O, was examined with respect to thermal stability in contact with molten silicon. The results of X-ray analysis indicate that this material is converted to both alpha - and beta-Si3N4 in the presence of molten silicon. Experiments on the stability of CVD SiOxNy shoe that this material can be maintained in contact with molten silicon (sessile drop test) for greater than 30 h at 1450 C without total decompositon. These layers are converted mainly to beta-Si3N4.

Influence of low energy argon plasma treatment on the moisture barrier performance of hot wire-CVD grown SiNx multilayers

NASA Astrophysics Data System (ADS)

Majee, Subimal; Fátima Cerqueira, Maria; Tondelier, Denis; Geffroy, Bernard; Bonnassieux, Yvan; Alpuim, Pedro; Bourée, Jean Eric

2014-01-01

The reliability and stability are key issues for the commercial utilization of organic photovoltaic devices based on flexible polymer substrates. To increase the shelf-lifetime of these devices, transparent moisture barriers of silicon nitride (SiNx) films are deposited at low temperature by hot wire CVD (HW-CVD) process. Instead of the conventional route based on organic/inorganic hybrid structures, this work defines a new route consisting in depositing multilayer stacks of SiNx thin films, each single layer being treated by argon plasma. The plasma treatment allows creating smoother surface and surface atom rearrangement. We define a critical thickness of the single layer film and focus our attention on the effect of increasing the number of SiNx single-layers on the barrier properties. A water vapor transmission rate (WVTR) of 2 × 10-4 g/(m2·day) is reported for SiNx multilayer stack and a physical interpretation of the plasma treatment effect is given.

Globalization, Work, and Cardiovascular Disease.

PubMed

Schnall, Peter L; Dobson, Marnie; Landsbergis, Paul

2016-10-01

Cardiovascular disease (CVD), a global epidemic, is responsible for about 30% of all deaths worldwide. While mortality rates from CVD have been mostly declining in the advanced industrialized nations, CVD risk factors, including hypertension, obesity, and diabetes, have been on the increase everywhere. Researchers investigating the social causes of CVD have produced a robust body of evidence documenting the relationships between the work environment and CVD, including through the mechanisms of psychosocial work stressors. We review the empirical evidence linking work, psychosocial stressors, and CVD. These work stressors can produce chronic biologic arousal and promote unhealthy behaviors and thus, increased CVD risk. We offer a theoretical model that illustrates how economic globalization influences the labor market and work organization in high-income countries, which, in turn, exacerbates job characteristics, such as demands, low job control, effort-reward imbalance, job insecurity, and long work hours. There is also a growing interest in "upstream" factors among work stress researchers, including precarious employment, downsizing/restructuring, privatization, and lean production. We conclude with suggestions for future epidemiologic research on the role of work in the development of CVD, as well as policy recommendations for prevention of work-related CVD. © The Author(s) 2016.

Association Between Hospitalization for Pneumonia and Subsequent Risk of Cardiovascular Disease

PubMed Central

Corrales-Medina, Vicente F.; Alvarez, Karina N.; Weissfeld, Lisa A.; Angus, Derek C.; Chirinos, Julio A.; Chang, Chung-Chou H.; Newman, Anne; Loehr, Laura; Folsom, Aaron R.; Elkind, Mitchell S.; Lyles, Mary F.; Kronmal, Richard A.; Yende, Sachin

2015-01-01

IMPORTANCE The risk of cardiovascular disease (CVD) after infection is poorly understood. OBJECTIVE To determine whether hospitalization for pneumonia is associated with an increased short-term and long-term risk of CVD. DESIGN, SETTINGS, AND PARTICIPANTS We examined 2 community-based cohorts: the Cardiovascular Health Study (CHS, n = 5888; enrollment age, ≥65 years; enrollment period, 1989–1994) and the Atherosclerosis Risk in Communities study (ARIC, n = 15 792; enrollment age, 45-64 years; enrollment period, 1987–1989). Participants were followed up through December 31, 2010. We matched each participant hospitalized with pneumonia to 2 controls. Pneumonia cases and controls were followed for occurrence of CVD over 10 years after matching. We estimated hazard ratios (HRs) for CVD at different time intervals, adjusting for demographics, CVD risk factors, subclinical CVD, comorbidities, and functional status. EXPOSURES Hospitalization for pneumonia. MAIN OUTCOMES AND MEASURES Incident CVD (myocardial infarction, stroke, and fatal coronary heart disease). RESULTS Of 591 pneumonia cases in CHS, 206 had CVD events over 10 years after pneumonia hospitalization. Compared with controls, CVD risk among pneumonia cases was highest during the first year after hospitalization and remained significantly higher than among controls through 10 years. In ARIC, of 680 pneumonia cases, 112 had CVD events over 10 years after hospitalization. After the second year, CVD risk among pneumonia cases was not significantly higher than among controls. Pneumonia Cases Controls HR (95% CI) CHS No. of participants 591 1182 CVD events  0-30 d 54 6 4.07 (2.86-5.27)  31-90 d 11 9 2.94 (2.18-3.70)  91 d-1 y 22 55 2.10 (1.59-2.60)  9-10 y 4 12 1.86 (1.18-2.55) ARIC No. of participants 680 1360 CVD events  0-30 d 4 3 2.38 (1.12-3.63)  31-90 d 4 0 2.40 (1.23-3.47)  91 d-1 y 11 8 2.19 (1.20-3.19)  1-2 y 8 7 1.88 (1.10-2.66) CONCLUSIONS AND RELEVANCE Hospitalization for pneumonia was associated with increased short-term and long-term risk of CVD, suggesting that pneumonia may be a risk factor for CVD. PMID:25602997

Sick Populations and Sick Subpopulations: Reducing Disparities in Cardiovascular Disease Between Blacks and Whites in the United States.

PubMed

Lu, Yuan; Ezzati, Majid; Rimm, Eric B; Hajifathalian, Kaveh; Ueda, Peter; Danaei, Goodarz

2016-08-09

Cardiovascular disease (CVD) death rates are much higher in blacks than whites in the United States. It is unclear how CVD risk and events are distributed among blacks versus whites and how interventions reduce racial disparities. We developed risk models for fatal and for fatal and nonfatal CVD using 8 cohorts in the United States. We used 6154 adults who were 50 to 69 years of age in the National Health and Nutrition Examination Survey 1999 to 2012 to estimate the distributions of risk and events in blacks and whites. We estimated the total and disparity impacts of a range of population-wide, targeted, and risk-based interventions on 10-year CVD risks and event rates. Twenty-five percent (95% confidence interval [CI], 22-28) of black men and 12% (95% CI, 10-14) of black women were at ≥6.67% risk of fatal CVD (almost equivalent to 20% risk of fatal or nonfatal CVD) compared with 10% (95% CI, 8-12) of white men and 3% (95% CI, 2-4) of white women. These high-risk individuals accounted for 55% (95% CI, 49-59) of CVD deaths among black men and 42% (95% CI, 35-46) in black women compared with 30% (95% CI, 24-35) in white men and 18% (95% CI, 13-22) in white women. We estimated that an intervention that treated multiple risk factors in high-risk individuals could reduce black-white difference in CVD death rate from 1659 to 1244 per 100 000 in men and from 1320 to 897 in women. Rates of fatal and nonfatal CVD were generally similar between black and white men. In women, a larger proportion of women were at ≥7.5% risk of CVD (30% versus 19% in whites), and an intervention that targeted multiple risk factors among this group was estimated to reduce black-white differences in CVD rates from 1688 to 1197 per 100 000. A substantially larger proportion of blacks have a high risk of fatal CVD and bear a large share of CVD deaths. A risk-based intervention that reduces multiple risk factors could substantially reduce overall CVD rates and racial disparities in CVD death rates. © 2016 American Heart Association, Inc.

Synthesis and characterization of catalysts based on mesoporous silica partially hydrophobized for technological applications.

PubMed

Martins, Amanda R; Salviano, Adriana B; Oliveira, Aline A S; Mambrini, Raquel V; Moura, Flávia C C

2017-03-01

In this work, mesoporous silica mobil composition of matter no. 41 (MCM-41) was synthesized by the sol-gel method. Two different surface modifications were made to transform this material into a very active adsorbent and catalyst support: (i) impregnation of iron nanoparticles and (ii) hydrophobization via chemical vapor deposition (CVD) with ethanol. The materials prepared with different iron contents, i.e., 2.5, 5, and 10 %, after hydrophobization, were characterized by several techniques. CHN analysis and Raman spectroscopy proved that approximately 15 % of carbon is deposited during CVD process mainly as organized carbonaceous structures. The specific surface area was determined by the BET method as up to 1080 m 2  g -1 , which explains the excellent results of the materials in the adsorption of model dyes methylene blue and indigo carmine. Mössbauer spectroscopy, thermogravimetric (TG)/DTG analysis, and transmission electron microscopy (TEM) images showed that the iron supported may be partially reduced during the CVD process to Fe 2+ species, which are stabilized by the carbon coating. This iron species plays an important role in the oxidation of different contaminants, such as quinoline and methylene blue. The results obtained in the catalytic tests showed to be very promising.

A wearable smartphone-based platform for real-time cardiovascular disease detection via electrocardiogram processing.

PubMed

Oresko, Joseph J; Duschl, Heather; Cheng, Allen C

2010-05-01

Cardiovascular disease (CVD) is the single leading cause of global mortality and is projected to remain so. Cardiac arrhythmia is a very common type of CVD and may indicate an increased risk of stroke or sudden cardiac death. The ECG is the most widely adopted clinical tool to diagnose and assess the risk of arrhythmia. ECGs measure and display the electrical activity of the heart from the body surface. During patients' hospital visits, however, arrhythmias may not be detected on standard resting ECG machines, since the condition may not be present at that moment in time. While Holter-based portable monitoring solutions offer 24-48 h ECG recording, they lack the capability of providing any real-time feedback for the thousands of heart beats they record, which must be tediously analyzed offline. In this paper, we seek to unite the portability of Holter monitors and the real-time processing capability of state-of-the-art resting ECG machines to provide an assistive diagnosis solution using smartphones. Specifically, we developed two smartphone-based wearable CVD-detection platforms capable of performing real-time ECG acquisition and display, feature extraction, and beat classification. Furthermore, the same statistical summaries available on resting ECG machines are provided.

Complement Activation: An Emerging Player in the Pathogenesis of Cardiovascular Disease

PubMed Central

Carter, Angela M.

2012-01-01

A wealth of evidence indicates a fundamental role for inflammation in the pathogenesis of cardiovascular disease (CVD), contributing to the development and progression of atherosclerotic lesion formation, plaque rupture, and thrombosis. An increasing body of evidence supports a functional role for complement activation in the pathogenesis of CVD through pleiotropic effects on endothelial and haematopoietic cell function and haemostasis. Prospective and case control studies have reported strong relationships between several complement components and cardiovascular outcomes, and in vitro studies and animal models support a functional effect. Complement activation, in particular, generation of C5a and C5b-9, influences many processes involved in the development and progression of atherosclerosis, including promotion of endothelial cell activation, leukocyte infiltration into the extracellular matrix, stimulation of cytokine release from vascular smooth muscle cells, and promotion of plaque rupture. Complement activation also influences thrombosis, involving components of the mannose-binding lectin pathway, and C5b-9 in particular, through activation of platelets, promotion of fibrin formation, and impairment of fibrinolysis. The participation of the complement system in inflammation and thrombosis is consistent with the physiological role of the complement system as a rapid effector system conferring protection following vessel injury. However, in the context of CVD, these same processes contribute to development of atherosclerosis, plaque rupture, and thrombosis. PMID:24278688

Thermal barrier coatings on gas turbine blades: Chemical vapor deposition (Review)

NASA Astrophysics Data System (ADS)

Igumenov, I. K.; Aksenov, A. N.

2017-12-01

Schemes are presented for experimental setups (reactors) developed at leading scientific centers connected with the development of technologies for the deposition of coatings using the CVD method: at the Technical University of Braunschweig (Germany), the French Aerospace Research Center, the Materials Research Institute (Tohoku University, Japan) and the National Laboratory Oak Ridge (USA). Conditions and modes for obtaining the coatings with high operational parameters are considered. It is established that the formed thermal barrier coatings do not fundamentally differ in their properties (columnar microstructure, thermocyclic resistance, thermal conductivity coefficient) from standard electron-beam condensates, but the highest growth rates and the perfection of the crystal structure are achieved in the case of plasma-chemical processes and in reactors with additional laser or induction heating of a workpiece. It is shown that CVD reactors can serve as a basis for the development of rational and more advanced technologies for coating gas turbine blades that are not inferior to standard electron-beam plants in terms of the quality of produced coatings and have a much simpler and cheaper structure. The possibility of developing a new technology based on CVD processes for the formation of thermal barrier coatings with high operational parameters is discussed, including a set of requirements for industrial reactors, high-performance sources of vapor precursors, and promising new materials.

Synthesis of graphene by cobalt-catalyzed decomposition of methane in plasma-enhanced CVD: Optimization of experimental parameters with Taguchi method

NASA Astrophysics Data System (ADS)

Mehedi, H.-A.; Baudrillart, B.; Alloyeau, D.; Mouhoub, O.; Ricolleau, C.; Pham, V. D.; Chacon, C.; Gicquel, A.; Lagoute, J.; Farhat, S.

2016-08-01

This article describes the significant roles of process parameters in the deposition of graphene films via cobalt-catalyzed decomposition of methane diluted in hydrogen using plasma-enhanced chemical vapor deposition (PECVD). The influence of growth temperature (700-850 °C), molar concentration of methane (2%-20%), growth time (30-90 s), and microwave power (300-400 W) on graphene thickness and defect density is investigated using Taguchi method which enables reaching the optimal parameter settings by performing reduced number of experiments. Growth temperature is found to be the most influential parameter in minimizing the number of graphene layers, whereas microwave power has the second largest effect on crystalline quality and minor role on thickness of graphene films. The structural properties of PECVD graphene obtained with optimized synthesis conditions are investigated with Raman spectroscopy and corroborated with atomic-scale characterization performed by high-resolution transmission electron microscopy and scanning tunneling microscopy, which reveals formation of continuous film consisting of 2-7 high quality graphene layers.

Synthesis of graphene by cobalt-catalyzed decomposition of methane in plasma-enhanced CVD: Optimization of experimental parameters with Taguchi method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mehedi, H.-A.; Baudrillart, B.; Gicquel, A.

2016-08-14

This article describes the significant roles of process parameters in the deposition of graphene films via cobalt-catalyzed decomposition of methane diluted in hydrogen using plasma-enhanced chemical vapor deposition (PECVD). The influence of growth temperature (700–850 °C), molar concentration of methane (2%–20%), growth time (30–90 s), and microwave power (300–400 W) on graphene thickness and defect density is investigated using Taguchi method which enables reaching the optimal parameter settings by performing reduced number of experiments. Growth temperature is found to be the most influential parameter in minimizing the number of graphene layers, whereas microwave power has the second largest effect on crystalline qualitymore » and minor role on thickness of graphene films. The structural properties of PECVD graphene obtained with optimized synthesis conditions are investigated with Raman spectroscopy and corroborated with atomic-scale characterization performed by high-resolution transmission electron microscopy and scanning tunneling microscopy, which reveals formation of continuous film consisting of 2–7 high quality graphene layers.« less

Acarbose Treatment and the Risk of Cardiovascular Disease in Type 2 Diabetic Patients: A Nationwide Seven-Year Follow-Up Study

PubMed Central

Chen, Jui-Ming; Chang, Cheng-Wei; Lin, Ying-Chieh; Horng, Jorng-Tzong; Sheu, Wayne H.-H.

2014-01-01

Objective. To investigate the potential benefits of acarbose treatment on cardiovascular disease (CVD) in patients with type 2 diabetes by using nationwide insurance claim dataset. Research Design and Methods. Among 644,792 newly diagnosed type 2 diabetic patients without preexisting CVD in a nationwide cohort study, 109,139 (16.9%) who had received acarbose treatment were analyzed for CVD risk. Those with CVD followed by acarbose therapy were also subjected to analysis. Result. During 7 years of follow-up, 5,081 patients (4.7%) developed CVD. The crude hazard ratio (HR) and adjusted HR were 0.66 and 0.99, respectively. The adjusted HR of CVD was 1.19, 0.70, and 0.38 when the duration of acarbose use was <12 months, 12–24 months, and >24 months, respectively. Adjusted HR was 1.14, 0.64, and 0.41 with acarbose cumulative doses <54,750 mg, 54,751 to 109,500 mg, and >109,500 mg, respectively. Conclusion. In patients with type 2 diabetes without preexisting CVD, treatment with acarbose showed a transient increase in incidence of CVD in the initial 12 months followed by significant reductions of CVD in prolonged acarbose users. After the first CVD events, continuous use of acarbose revealed neutral effect within the first 12 months. The underlying mechanisms require further investigations. PMID:25197673

Acarbose treatment and the risk of cardiovascular disease in type 2 diabetic patients: a nationwide seven-year follow-up study.

PubMed

Chen, Jui-Ming; Chang, Cheng-Wei; Lin, Ying-Chieh; Horng, Jorng-Tzong; Sheu, Wayne H-H

2014-01-01

To investigate the potential benefits of acarbose treatment on cardiovascular disease (CVD) in patients with type 2 diabetes by using nationwide insurance claim dataset. Among 644,792 newly diagnosed type 2 diabetic patients without preexisting CVD in a nationwide cohort study, 109,139 (16.9%) who had received acarbose treatment were analyzed for CVD risk. Those with CVD followed by acarbose therapy were also subjected to analysis. During 7 years of follow-up, 5,081 patients (4.7%) developed CVD. The crude hazard ratio (HR) and adjusted HR were 0.66 and 0.99, respectively. The adjusted HR of CVD was 1.19, 0.70, and 0.38 when the duration of acarbose use was <12 months, 12-24 months, and >24 months, respectively. Adjusted HR was 1.14, 0.64, and 0.41 with acarbose cumulative doses <54,750 mg, 54,751 to 109,500 mg, and >109,500 mg, respectively. In patients with type 2 diabetes without preexisting CVD, treatment with acarbose showed a transient increase in incidence of CVD in the initial 12 months followed by significant reductions of CVD in prolonged acarbose users. After the first CVD events, continuous use of acarbose revealed neutral effect within the first 12 months. The underlying mechanisms require further investigations.

Small artery elasticity predicts future cardiovascular events in chinese patients with angiographic coronary artery disease.

PubMed

Wan, Zhaofei; Liu, Xiaojun; Wang, Xinhong; Liu, Fuqiang; Liu, Weimin; Wu, Yue; Pei, Leilei; Yuan, Zuyi

2014-04-01

Arterial elasticity has been shown to predict cardiovascular disease (CVD) in apparently healthy populations. The present study aimed to explore whether arterial elasticity could predict CVD events in Chinese patients with angiographic coronary artery disease (CAD). Arterial elasticity of 365 patients with angiographic CAD was measured. During follow-up (48 months; range 6-65), 140 CVD events occurred (including 34 deaths). Univariate Cox analysis demonstrated that both large arterial elasticity and small arterial elasticity were significant predictors of CVD events. Multivariate Cox analysis indicated that small arterial elasticity remained significant. Kaplan-Meier analysis showed that the probability of having a CVD event/CVD death increased with a decrease of small arterial elasticity (P < .001, respectively). Decreased small arterial elasticity independently predicts the risk of CVD events in Chinese patients with angiographic CAD.

Evolution of Cardiovascular Disease During the Transition to End-Stage Renal Disease.

PubMed

Bansal, Nisha

2017-03-01

Cardiovascular disease (CVD) remains the leading cause of morbidity and mortality in patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD). The rate of death in incident dialysis patients remains high. This has led to interest in the study of the evolution of CVD during the critical transition period from CKD to ESRD. Understanding the natural history and risk factors of clinical and subclinical CVD during this transition may help guide the timing of appropriate CVD therapies to improve outcomes in patients with kidney disease. This review provides an overview of the epidemiology of subclinical and clinical CVD during the transition from CKD to ESRD and discusses clinical trials of CVD therapies to mitigate risk of CVD in CKD and ESRD patients. Copyright © 2017 Elsevier Inc. All rights reserved.

Surface passivation of InGaP/GaAs HBT using silicon-nitride film deposited by ECR CVD plasma

NASA Astrophysics Data System (ADS)

Manera, L. T.; Zoccal, L. B.; Diniz, J. A.; Tatsch, P. J.; Doi, I.

2008-07-01

In this paper we have developed a passivation technique with silicon-nitride (SiN X) film that requires no surface pre-treatment, and is fully compatible to monolithic microwave integrated circuits (MMICs). The nitride depositions were carried out by ECR-CVD (electron cyclotron resonance-chemical vapor deposition) directly over InGaP/GaAs heterojunction structures, which are used for heterojunction bipolar transistors (HBTs). Optical emission spectrometry (OES) was used for plasma characterization, and low formation of H and NH molecules in the gas phase was detected at pressure of 2.5 mTorr. These molecules can degrade III-V semiconductor surfaces due to the preferential loss of As or P and hydrogen incorporation at the substrate. The substrates were cleaned with organic solvents using a Sox-let distillate. The ECR depositions were carried out at a fixed substrate temperature of 20 °C, SiH 4/N 2 flow ratio of 1, Ar flow of 5 sccm pressure of 2.5 mTorr and microwave (2.45 GHz) power of 250 W and RF (13.56 MHz) power of 4 W. We have applied this film for InGaP/GaAs HBT fabrication process with excellent results, where two major contribuiton is related to this passivation technique, the enhancement in the transistor dc gain β and the improvement in the signal-to-noise ratio when compared unpassivated and passivated devices.

Growth and Characterization of Epitaxial Piezoelectric and Semiconductor Films.

DTIC Science & Technology

1980-07-01

quality epitaxial films at low growth rates. This process is limited to films up to a few microns thickness. The aluminum chloride/ ammonia CVD process has... scrubber through a rotary Vacuum pump maintaining Reactions.-DEZ is an electron deficient compound a pressure of about 400 Torr inside the reaction chain

Diamond Technology Initiative

DTIC Science & Technology

1994-05-01

thermal stresses of 10 million Watts per meter, 1,000 times better than Zerodur *. This property is also important for many thermal management...products UTD has coated to date include: • Optical windows, lenses, and mirrors . Zinc sulfide infrared windows coated with a 2.5 micron-thick...implants 16, 49 microwave plasma-enhanced CVD 2 mirrors , diamond-coated 49 models of diamond growth 10, 25, 33, 34, 39 moderators 10

Augmenting static and dynamic mechanical strength of carbon nanotube/epoxy soft nanocomposites via modulation of purification and functionalization routes.

PubMed

Billing, Beant Kaur; Dhar, Purbarun; Singh, Narinder; Agnihotri, Prabhat K

2018-01-03

A detailed experimental investigation was carried out to establish the relationship between CNT purification and functionalization routes and the average response of CNT/epoxy nanocomposites under static and dynamic loading. It was shown that the relative improvement in the mechanical properties of the epoxy matrix due to the addition of CNTs depends on the choice of purification and functionalization steps. A better dispersion of CNTs was recorded for the functionalized CNTs as compared to the oxidized and CVD grown CNTs. Moreover, tensile, 3-point bending and nanoDMA testing performed on nanocomposites processed with CVD-grown, oxidized and functionalized CNTs revealed that COOH functionalization after the oxidation of CNTs at 350 °C is the optimized processing route to harness the excellent properties of CNTs in CNT/epoxy nanocomposites.

Role of hydrogen in the chemical vapor deposition growth of MoS2 atomic layers

NASA Astrophysics Data System (ADS)

Li, Xiao; Li, Xinming; Zang, Xiaobei; Zhu, Miao; He, Yijia; Wang, Kunlin; Xie, Dan; Zhu, Hongwei

2015-04-01

Hydrogen plays a crucial role in the chemical vapor deposition (CVD) growth of graphene. Here, we have revealed the roles of hydrogen in the two-step CVD growth of MoS2. Our study demonstrates that hydrogen acts as the following: (i) an inhibitor of the thermal-induced etching effect in the continuous film growth process; and (ii) a promoter of the desulfurization reaction by decreasing the S/Mo atomic ratio and the oxidation reaction of the obtained MoSx (0 < x < 2) films. A high hydrogen content of more than 100% in argon forms nano-sized circle-like defects and damages the continuity and uniformity of the film. Continuous MoS2 films with a high crystallinity and a nearly perfect S/Mo atomic ratio were finally obtained after sulfurization annealing with a hydrogen content in the range of 20%-80%. This insightful understanding reveals the crucial roles of hydrogen in the CVD growth of MoS2 and paves the way for the controllable synthesis of two-dimensional materials.Hydrogen plays a crucial role in the chemical vapor deposition (CVD) growth of graphene. Here, we have revealed the roles of hydrogen in the two-step CVD growth of MoS2. Our study demonstrates that hydrogen acts as the following: (i) an inhibitor of the thermal-induced etching effect in the continuous film growth process; and (ii) a promoter of the desulfurization reaction by decreasing the S/Mo atomic ratio and the oxidation reaction of the obtained MoSx (0 < x < 2) films. A high hydrogen content of more than 100% in argon forms nano-sized circle-like defects and damages the continuity and uniformity of the film. Continuous MoS2 films with a high crystallinity and a nearly perfect S/Mo atomic ratio were finally obtained after sulfurization annealing with a hydrogen content in the range of 20%-80%. This insightful understanding reveals the crucial roles of hydrogen in the CVD growth of MoS2 and paves the way for the controllable synthesis of two-dimensional materials. Electronic supplementary information (ESI) available: Low-magnification optical images; Raman spectra of 0% and 5% H2 samples; AFM characterization; Schematic of the film before and after sulfurization annealing; Schematic illustrations of two typical Raman-active phonon modes (E12g, A1g); Raman (mapping) spectra for 40% and 80% H2 samples before and after sulfurization annealing; PL spectra. See DOI: 10.1039/c5nr00904a

Chemical vapor deposition of epitaxial silicon

DOEpatents

Berkman, Samuel

1984-01-01

A single chamber continuous chemical vapor deposition (CVD) reactor is described for depositing continuously on flat substrates, for example, epitaxial layers of semiconductor materials. The single chamber reactor is formed into three separate zones by baffles or tubes carrying chemical source material and a carrier gas in one gas stream and hydrogen gas in the other stream without interaction while the wafers are heated to deposition temperature. Diffusion of the two gas streams on heated wafers effects the epitaxial deposition in the intermediate zone and the wafers are cooled in the final zone by coolant gases. A CVD reactor for batch processing is also described embodying the deposition principles of the continuous reactor.

Virgin coconut oil and its potential cardioprotective effects.

PubMed

Babu, Abraham Samuel; Veluswamy, Sundar Kumar; Arena, Ross; Guazzi, Marco; Lavie, Carl J

2014-11-01

Emphasis on diet to improve the cardiovascular (CV) risk profile has been the focus of many studies. Recently, virgin coconut oil (VCO) has been growing in popularity due to its potential CV benefits. The chemical properties and the manufacturing process of VCO make this oil healthier than its copra-derived counterpart. This review highlights the mechanism through which saturated fatty acids contribute to CV disease (CVD), how oils and fats contribute to the risk of CVD, and the existing views on VCO and how its cardioprotective effects may make this a possible dietary intervention in isolation or in combination with exercise to help reduce the burden of CVDs.

Evaluating Periodontal Treatment to Prevent Cardiovascular Disease: Challenges and Possible Solutions.

PubMed

Merchant, Anwar T; Virani, Salim S

2017-01-01

Periodontal disease is correlated with cardiovascular disease (CVD) in observational studies, but a causal connection has not been established. The empirical evidence linking periodontal disease and CVD consists of a large body of observational and mechanistic studies, but a limited number of clinical trials evaluating the effects of periodontal treatment on surrogate CVD endpoints. No randomized controlled trial has been conducted to evaluate the effect of periodontal treatment on CVD risk. In this review, we have summarized these data, described possible biological mechanisms linking periodontal disease and CVD, discussed barriers to conducting a randomized controlled trial to evaluate this hypothesis, and provided an alternative analytical approach using causal inference methods to answer the question. The public health implications of addressing this question can be significant because periodontal disease is under-treated, and highly prevalent among adults at risk of CVD. Even a small beneficial effect of periodontal treatment on CVD risk can be important.

Cardiovascular Disease Prevention: Training Opportunities, the Challenges, and Future Directions.

PubMed

Saeed, Anum; Dabhadkar, Kaustubh; Virani, Salim S; Jones, Peter H; Ballantyne, Christie M; Nambi, Vijay

2018-05-21

Cardiovascular diseases (CVDs) are a leading cause of morbidity and mortality worldwide, necessitating major efforts in prevention. This review summarizes the currently available training opportunities in CVD prevention for fellows-in-training (FITs) and residents. We also highlight the challenges and future directions for CVD prevention as a field and propose a structure for an inclusive CVD prevention training program. At present, there is a lack of centralized training resources for FITs and residents interested in pursuing a career in CVD prevention. Training in CVD prevention is not an accredited subspecialty fellowship by the American Council of Graduate Medical Education (ACGME). Although there are several independent training programs under the broad umbrella of CVD prevention focusing on different aspects of prevention, there is no unified curriculum or training. More collaborative efforts are needed to identify CVD prevention as an ACGME-accredited subspecialty fellowship. Providing more resources can encourage and produce more leaders in this essential field.

Assessment of Cardiovascular Disease Risk in South Asian Populations

PubMed Central

Hussain, S. Monira; Oldenburg, Brian; Zoungas, Sophia; Tonkin, Andrew M.

2013-01-01

Although South Asian populations have high cardiovascular disease (CVD) burden in the world, their patterns of individual CVD risk factors have not been fully studied. None of the available algorithms/scores to assess CVD risk have originated from these populations. To explore the relevance of CVD risk scores for these populations, literature search and qualitative synthesis of available evidence were performed. South Asians usually have higher levels of both “classical” and nontraditional CVD risk factors and experience these at a younger age. There are marked variations in risk profiles between South Asian populations. More than 100 risk algorithms are currently available, with varying risk factors. However, no available algorithm has included all important risk factors that underlie CVD in these populations. The future challenge is either to appropriately calibrate current risk algorithms or ideally to develop new risk algorithms that include variables that provide an accurate estimate of CVD risk. PMID:24163770

Prevalence of undiagnosed cardiovascular risk factors and 10-year CVD risk in male steel industry workers.

PubMed

Gray, Benjamin J; Bracken, Richard M; Turner, Daniel; Morgan, Kerry; Mellalieu, Stephen D; Thomas, Michael; Williams, Sally P; Williams, Meurig; Rice, Sam; Stephens, Jeffrey W

2014-05-01

To assess the prevalence of undiagnosed cardiovascular disease (CVD) in a cohort of male steelworkers in South Wales, UK. Male steel industry workers (n = 221) with no prior diagnosis of CVD or diabetes accepted a CVD risk assessment within the work environment. Demographic, anthropometric, family, and medical histories were all recorded and capillary blood samples obtained. The 10-year CVD risk was predicted using the QRISK2-2012 algorithm. Up to 81.5% of workers were either overweight or obese. More than 20% of workers were found to have diastolic hypertension, high total cholesterol, and/or a total cholesterol/high-density lipoprotein ratio of six or more. Over one quarter of workers assessed had an increased 10-year CVD risk. Despite a physically demanding occupation, risk assessment in the workplace uncovered significant occult factors in CVD risk in a sample of male heavy industry workers.

Association of educational status with cardiovascular disease: Teheran Lipid and Glucose Study.

PubMed

Hajsheikholeslami, Farhad; Hatami, Masumeh; Hadaegh, Farzad; Ghanbarian, Arash; Azizi, Fereidoun

2011-06-01

The aim of this study was to evaluate the associations between educational level and cardiovascular disease (CVD) in an older Iranian population. To estimate the odds ratio (OR) of educational level in a cross-sectional study, logistic regression analysis was used on 1,788 men and 2,204 women (222 men and 204 women positive based on their CVD status) aged ≥ 45 years. In men, educational levels of college degree and literacy level below diploma were inversely associated with CVD in the multivariate model [0.52 (0.28-0.94), 0.61 (0.40-0.92), respectively], but diploma level did not show any significant association with CVD, neither in the crude model nor in the multivariate model. In women, increase in educational level was inversely associated with risk of CVD in the crude model, but in the multivariate adjusted model, literacy level below diploma decreased risk of CVD by 39%, compared with illiteracy. Our findings support those of developed countries that, along with other CVD risk factors, educational status has an inverse association with CVD among a representative Iranian population of older men and women.

Cardiovascular risk-factor knowledge and risk perception among HIV-infected adults.

PubMed

Cioe, Patricia A; Crawford, Sybil L; Stein, Michael D

2014-01-01

Cardiovascular disease (CVD) has emerged as a major cause of morbidity and mortality in HIV-infected adults. Research in noninfected populations has suggested that knowledge of CVD risk factors significantly influences perceptions of risk. This cross-sectional study describes CVD risk factor knowledge and risk perception in HIV-infected adults. We recruited 130 HIV-infected adults (mean age = 48 years, 62% male, 56% current smokers, mean years since HIV diagnosis, 14.7). The mean CVD risk factor knowledge score was fairly high. However, controlling for age, CVD risk factor knowledge was not predictive of perceived risk [F(1, 117) = 0.13, p > .05]. Estimated risk and perceived risk were weakly but significantly correlated; r (126) = .24, p = .01. HIV-infected adults are at increased risk for CVD. Despite having adequate risk-factor knowledge, CVD risk perception was inaccurate. Improving risk perception and developing CVD risk reduction interventions for this population are imperative. Copyright © 2014 Association of Nurses in AIDS Care. Published by Elsevier Inc. All rights reserved.

Methodologic quality of meta-analyses and systematic reviews on the Mediterranean diet and cardiovascular disease outcomes: a review.

PubMed

Huedo-Medina, Tania B; Garcia, Marissa; Bihuniak, Jessica D; Kenny, Anne; Kerstetter, Jane

2016-03-01

Several systematic reviews/meta-analyses published within the past 10 y have examined the associations of Mediterranean-style diets (MedSDs) on cardiovascular disease (CVD) risk. However, these reviews have not been evaluated for satisfying contemporary methodologic quality standards. This study evaluated the quality of recent systematic reviews/meta-analyses on MedSD and CVD risk outcomes by using an established methodologic quality scale. The relation between review quality and impact per publication value of the journal in which the article had been published was also evaluated. To assess compliance with current standards, we applied a modified version of the Assessment of Multiple Systematic Reviews (AMSTARMedSD) quality scale to systematic reviews/meta-analyses retrieved from electronic databases that had met our selection criteria: 1) used systematic or meta-analytic procedures to review the literature, 2) examined MedSD trials, and 3) had MedSD interventions independently or combined with other interventions. Reviews completely satisfied from 8% to 75% of the AMSTARMedSD items (mean ± SD: 31.2% ± 19.4%), with those published in higher-impact journals having greater quality scores. At a minimum, 60% of the 24 reviews did not disclose full search details or apply appropriate statistical methods to combine study findings. Only 5 of the reviews included participant or study characteristics in their analyses, and none evaluated MedSD diet characteristics. These data suggest that current meta-analyses/systematic reviews evaluating the effect of MedSD on CVD risk do not fully comply with contemporary methodologic quality standards. As a result, there are more research questions to answer to enhance our understanding of how MedSD affects CVD risk or how these effects may be modified by the participant or MedSD characteristics. To clarify the associations between MedSD and CVD risk, future meta-analyses and systematic reviews should not only follow methodologic quality standards but also include more statistical modeling results when data allow. © 2016 American Society for Nutrition.

Association between diet-related inflammation, all-cause, all-cancer, and cardiovascular disease mortality, with special focus on prediabetics: findings from NHANES III.

PubMed

Deng, Fang Emily; Shivappa, Nitin; Tang, YiFan; Mann, Joshua R; Hebert, James R

2017-04-01

Chronic inflammation is associated with increased risk of cancer, cardiovascular disease (CVD), and diabetes. The role of pro-inflammatory diet in the risk of cancer mortality and CVD mortality in prediabetics is unclear. We examined the relationship between diet-associated inflammation, as measured by dietary inflammatory index (DII) score, and mortality, with special focus on prediabetics. This prospective cohort study used data from the Third National Health and Nutrition Examination Survey (NHANES III). We categorized 13,280 eligible participants, ages 20-90 years, according to glycosylated hemoglobin (HgbA1c) level and identified 2681 with prediabetes, defined as a glycosylated hemoglobin percentage of 5.7-6.4. Computation of DII scores and all statistical analyses were conducted in 2015. The DII was computed based on baseline dietary intake assessed using 24-h dietary recalls (1988-1994). Mortality was determined from the National Death Index records through 2006. Over follow-up ranging between 135 and 168 person-months, a total of 3016 deaths were identified, including 676 cancer, 192 lung cancer, 176 digestive-tract cancer, and 1328 CVD deaths. Cox proportional hazard regression was used to estimate hazard ratios. The prevalence of prediabetes was 20.19 %. After controlling for age, sex, race, HgbA1c, current smoking, physical activity, BMI, and systolic blood pressure, DII scores in tertile III (vs tertile I) was significantly associated with mortality from all causes (HR 1.39, 95 % CI 1.13, 1.72), CVD (HR 1.44, 95 % CI 1.02, 2.04), all cancers (HR 2.02, 95 % CI 1.27, 3.21), and digestive-tract cancer (HR 2.89, 95 % CI 1.08, 7.71). Findings for lung cancer (HR 2.01, 95 % CI 0.93, 4.34) suggested a likely effect. These results were moderately enhanced after additional adjustment for serum low-density lipoprotein and triglyceride and following eliminating deaths during the first year. A pro-inflammatory diet, as indicated by higher DII scores, is associated with an increased risk of all-cause, CVD, all-cancer, and digestive-tract cancer mortality among prediabetic subjects.

Prediction of cardiovascular disease risk among low-income urban dwellers in metropolitan Kuala Lumpur, Malaysia.

PubMed

Su, Tin Tin; Amiri, Mohammadreza; Mohd Hairi, Farizah; Thangiah, Nithiah; Bulgiba, Awang; Majid, Hazreen Abdul

2015-01-01

We aimed to predict the ten-year cardiovascular disease (CVD) risk among low-income urban dwellers of metropolitan Malaysia. Participants were selected from a cross-sectional survey conducted in Kuala Lumpur. To assess the 10-year CVD risk, we employed the Framingham risk scoring (FRS) models. Significant determinants of the ten-year CVD risk were identified using General Linear Model (GLM). Altogether 882 adults (≥30 years old with no CVD history) were randomly selected. The classic FRS model (figures in parentheses are from the modified model) revealed that 20.5% (21.8%) and 38.46% (38.9%) of respondents were at high and moderate risk of CVD. The GLM models identified the importance of education, occupation, and marital status in predicting the future CVD risk. Our study indicated that one out of five low-income urban dwellers has high chance of having CVD within ten years. Health care expenditure, other illness related costs and loss of productivity due to CVD would worsen the current situation of low-income urban population. As such, the public health professionals and policy makers should establish substantial effort to formulate the public health policy and community-based intervention to minimize the upcoming possible high mortality and morbidity due to CVD among the low-income urban dwellers.

Obesity-related inflammation & cardiovascular disease: efficacy of a yoga-based lifestyle intervention.

PubMed

Sarvottam, Kumar; Yadav, Raj Kumar

2014-06-01

Obesity is a global health burden and its prevalence is increasing substantially due to changing lifestyle. Chronic adiposity is associated with metabolic imbalance leading to dyslipidaemia, diabetes, hypertension and cardiovascular diseases (CVD). Adipose tissue acts as an endocrine organ releasing several adipocytokines, and is associated with increased levels of tissue and circulating inflammatory biomolecules causing vascular inflammation and atherogenesis. Further, inflammation is also associated independently with obesity as well as CVD. Keeping this in view, it is possible that a reduction in weight may lead to a decrease in inflammation, resulting in CVD risk reduction, and better management of patients with CVD. Lifestyle intervention has been endorsed by several health authorities in prevention and management of chronic diseases. A yoga-based lifestyle intervention appears to be a promising option in reducing the risk for CVD as well as management of patients with CVD as it is simple to follow and cost-effective with high compliance. The efficacy of such lifestyle intervention programmes is multifaceted, and is achieved via reduction in weight, obesity-related inflammation and stress, thereby culminating into risk reduction towards several chronic diseases including CVD. In this review, the association between obesity-related inflammation and CVD, and the role of yoga-based lifestyle intervention in prevention and management of CVD are discussed.

Genetic variation associated with cardiovascular risk in autoimmune diseases

PubMed Central

Perrotti, Pedro P.; Aterido, Adrià; Fernández-Nebro, Antonio; Cañete, Juan D.; Ferrándiz, Carlos; Tornero, Jesús; Gisbert, Javier P.; Domènech, Eugeni; Fernández-Gutiérrez, Benjamín; Gomollón, Fernando; García-Planella, Esther; Fernández, Emilia; Sanmartí, Raimon; Gratacós, Jordi; Martínez-Taboada, Víctor Manuel; Rodríguez-Rodríguez, Luís; Palau, Núria; Tortosa, Raül; Corbeto, Mireia L.; Lasanta, María L.; Marsal, Sara; Julià, Antonio

2017-01-01

Autoimmune diseases have a higher prevalence of cardiovascular events compared to the general population. The objective of this study was to investigate the genetic basis of cardiovascular disease (CVD) risk in autoimmunity. We analyzed genome-wide genotyping data from 6,485 patients from six autoimmune diseases that are associated with a high socio-economic impact. First, for each disease, we tested the association of established CVD risk loci. Second, we analyzed the association of autoimmune disease susceptibility loci with CVD. Finally, to identify genetic patterns associated with CVD risk, we applied the cross-phenotype meta-analysis approach (CPMA) on the genome-wide data. A total of 17 established CVD risk loci were significantly associated with CVD in the autoimmune patient cohorts. From these, four loci were found to have significantly different genetic effects across autoimmune diseases. Six autoimmune susceptibility loci were also found to be associated with CVD risk. Genome-wide CPMA analysis identified 10 genetic clusters strongly associated with CVD risk across all autoimmune diseases. Two of these clusters are highly enriched in pathways previously associated with autoimmune disease etiology (TNFα and IFNγ cytokine pathways). The results of this study support the presence of specific genetic variation associated with the increase of CVD risk observed in autoimmunity. PMID:28982122

Comparison of the quality of single-crystal diamonds grown on two types of seed substrates by MPCVD

NASA Astrophysics Data System (ADS)

Zhao, Yun; Guo, Yanzhao; Lin, Liangzhen; Zheng, Yuting; Hei, Lifu; Liu, Jinlong; Wei, Junjun; Chen, Liangxian; Li, Chengming

2018-06-01

Microwave plasma chemical vapor deposition (MPCVD) was used to grow single-crystal diamonds on two types of single-crystal diamond seed substrates prepared by high-pressure, high-temperature (HPHT) and chemical vapor deposition (CVD) methods. The quality of diamonds grown on the different seed substrates was compared. Fluorescence characteristics showed that the sectors of the HPHT seed substrates were obviously partitioned. Raman and absorption spectra showed that the CVD seed substrate produced higher-quality crystals with fewer nitrogen impurities. X-ray topography showed that the HPHT seed substrate had obvious growth sector boundaries, inclusions, dislocations, and stacking faults. The polarization characteristics of HPHT seed substrate were obvious, and the stress distribution was not uniform. When etching HPHT and CVD seed substrates using the same parameters, the etching morphology and extent of different growth sectors of the two substrates differed. Although extended defects were inevitably formed at the interface and propagated in the CVD layer, the dislocation density of a 1 mm-thick CVD layer grown on a CVD seed substrate was only half that of a 1 mm-thick CVD layer grown on an HPHT seed substrate. Therefore, the use of CVD seed substrate enabled the growth of a relatively higher-quality CVD single-crystal diamond.

Cardiovascular Disease in Latin American Patients with Systemic Lupus Erythematosus: A Cross-Sectional Study and a Systematic Review

PubMed Central

Amaya-Amaya, Jenny; Caro-Moreno, Julián; Molano-González, Nicolás; Mantilla, Rubén D.; Rojas-Villarraga, Adriana; Anaya, Juan-Manuel

2013-01-01

Objective. This study was performed to determine the prevalence of and associated risk factors for cardiovascular disease (CVD) in Latin American (LA) patients with systemic lupus erythematosus (SLE). Methods. First, a cross-sectional analytical study was conducted in 310 Colombian patients with SLE in whom CVD was assessed. Associated factors were examined by multivariate regression analyses. Second, a systematic review of the literature on CVD in SLE in LA was performed. Results. There were 133 (36.5%) Colombian SLE patients with CVD. Dyslipidemia, smoking, coffee consumption, and pleural effusion were positively associated with CVD. An independent effect of coffee consumption and cigarette on CVD was found regardless of gender and duration of disease. In the systematic review, 60 articles fulfilling the eligibility criteria were included. A wide range of CVD prevalence was found (4%–79.5%). Several studies reported ancestry, genetic factors, and polyautoimmunity as novel risk factors for such a condition. Conclusions. A high rate of CVD is observed in LA patients with SLE. Awareness of the observed risk factors should encourage preventive population strategies for CVD in patients with SLE aimed at facilitating the suppression of cigarette smoking and coffee consumption as well as at the tight control of dyslipidemia and other modifiable risk factors. PMID:24294522

Prediction of Cardiovascular Disease Risk among Low-Income Urban Dwellers in Metropolitan Kuala Lumpur, Malaysia

PubMed Central

Su, Tin Tin; Amiri, Mohammadreza; Mohd Hairi, Farizah; Thangiah, Nithiah; Majid, Hazreen Abdul

2015-01-01

We aimed to predict the ten-year cardiovascular disease (CVD) risk among low-income urban dwellers of metropolitan Malaysia. Participants were selected from a cross-sectional survey conducted in Kuala Lumpur. To assess the 10-year CVD risk, we employed the Framingham risk scoring (FRS) models. Significant determinants of the ten-year CVD risk were identified using General Linear Model (GLM). Altogether 882 adults (≥30 years old with no CVD history) were randomly selected. The classic FRS model (figures in parentheses are from the modified model) revealed that 20.5% (21.8%) and 38.46% (38.9%) of respondents were at high and moderate risk of CVD. The GLM models identified the importance of education, occupation, and marital status in predicting the future CVD risk. Our study indicated that one out of five low-income urban dwellers has high chance of having CVD within ten years. Health care expenditure, other illness related costs and loss of productivity due to CVD would worsen the current situation of low-income urban population. As such, the public health professionals and policy makers should establish substantial effort to formulate the public health policy and community-based intervention to minimize the upcoming possible high mortality and morbidity due to CVD among the low-income urban dwellers. PMID:25821810

Sarcopenic-obesity and cardiovascular disease risk in the elderly.

PubMed

Stephen, W C; Janssen, I

2009-05-01

To determine: 1) whether sarcopenic-obesity is a stronger predictor of cardiovascular disease (CVD) than either sarcopenia or obesity alone in the elderly, and 2) whether muscle mass or muscular strength is a stronger marker of CVD risk. Prospective cohort study. Participants included 3366 community-dwelling older (>or= 65 years) men and women who were free of CVD at baseline. Waist circumference (WC), bioimpedance analysis, and grip strength were used to measure abdominal obesity, whole-body muscle mass, and muscular strength, respectively. Subjects were classified as normal, sarcopenic, obese, or sarcopenic-obese based on measures of WC and either muscle mass or strength. Participants were followed for 8 years for CVD development and proportional hazard regression models were used to compare risk estimates for CVD in the four groups after adjusting for age, sex, race, income, smoking, alcohol, and cognitive status. Compared with the normal group, CVD risk was not significantly elevated within the obese, sarcopenic, or sarcopenic-obese groups as determined by WC and muscle mass. When determined by WC and muscle strength, CVD risk was not significantly increased in the sarcopenic or obese groups, but was increased by 23% (95% confidence interval: 0.99-1.54, P=0.06) within the sarcopenic-obese group. Sarcopenia and obesity alone were not sufficient to increase CVD risk. Sarcopenic-obesity, based on muscle strength but not muscle mass, was modestly associated with increased CVD risk. These findings imply that strength may be more important than muscle mass for CVD protection in old age.

Canada's contribution to global research in cardiovascular diseases.

PubMed

Nguyen, Hai V; de Oliveira, Claire; Wijeysundera, Harindra C; Wong, William W L; Woo, Gloria; Grootendorst, Paul; Liu, Peter P; Krahn, Murray D

2013-06-01

The burden of cardiovascular disease (CVD) in Canada and other developed countries is growing, in part because of the aging of the population and the alarming rise of obesity. Studying Canada's contribution to the global body of CVD research output will shed light on the effectiveness of investments in Canadian CVD research and inform if Canada has been responding to its CVD burden. Search was conducted using the Web-of-Science database for publications during 1981 through 2010 on major areas and specific interventions in CVD. Search was also conducted using Canadian and US online databases for patents issued between 1981 and 2010. Search data were used to estimate the proportions of the world's pool of research publications and of patents conducted by researchers based in Canada. The results indicate that Canada contributed 6% of global research in CVD during 1981 through 2010. Further, Canada's contribution shows a strong upward trend during the period. Based on patent data, Canada's contribution level was similar (5%-7%). Canada's contribution to the global pool of CVD research is on par with France and close to the UK, Japan, and Germany. Canada's contribution in global CVD research is higher than its average contribution in all fields of research (6% vs 3%). As the burden of chronic diseases including CVD rises with Canada's aging population, the increase in Canadian research into CVD is encouraging. Copyright © 2013 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

"Ikigai", Subjective Wellbeing, as a Modifier of the Parity-Cardiovascular Mortality Association　- The Japan Collaborative Cohort Study.

PubMed

Yasukawa, Sumiyo; Eguchi, Eri; Ogino, Keiki; Tamakoshi, Akiko; Iso, Hiroyasu

2018-04-25

Nulliparity is associated with an excess risk of cardiovascular disease (CVD). "Ikigai", subjective wellbeing in Japan, is associated with reduced risk of CVD. The impact of ikigai on the association between parity and the risk of CVD, however, has not been reported.Methods and Results:A total of 39,870 Japanese women aged 40-79 years without a history of CVD, cancer or insufficient information at baseline in 1988-1990, were enrolled and followed until the end of 2009. They were categorized into 7 groups according to parity number 0-≥6. Using Cox regression hazard modeling, the associations between parity and mortality from stroke, coronary artery disease, and total CVD were investigated. During the follow-up period, 2,121 total CVD deaths were documented. No association was observed between parity and stroke and CVD mortality in women with ikigai, but there was an association in those without ikigai. The multivariable hazard ratios of stroke and total CVD mortality for nulliparous women without ikigai vs. those with 1 child were 1.87 (95% CI: 1.15-3.05) and 1.46 (95% CI: 1.07-2.01), respectively, and that for stroke mortality in high parity women without ikigai was 1.56 (95% CI: 1.00-2.45). Nulliparous or high parity women without ikigai had higher mortality from stroke and/or total CVD, suggesting that ikigai attenuated the association between parity and CVD mortality in Japanese women.

Cocoa Polyphenols: Evidence from Epidemiological Studies.

PubMed

Matsumoto, Chisa

2018-01-01

Accumulating evidence suggests potential preventive effects of chocolate/cocoa on the risk of cardio vascular disease (CVD). However, cocoa products also contain high levels of sugar and fat, which increase CVD risk factors. Even, the identity of the substance in chocolate/cocoa that has a favorable effect on CVD and CVD risk factors remains unclear, growing evidence from experimental studies suggests that cocoa polyphenols might be a major contributor to cardiovascular-protective effects. However, epidemiological studies, which are necessary to evaluate an association between the risk of CVD and cocoa polyphenol, remain sparse. We will discuss recent evidence regarding the association between cocoa polyphenol consumption and the risks of CVD and its risk factors by reviewing recent epidemiological studies. We shall also provide some guidance for patient counseling and will discuss the public health implications for recommending cocoa polyphenol consumption to prevent CVD. Epidemiological studies evaluating the association between cocoa polyphenol itself and the risk of CVD are sparse. However, evidence from limited epidemiological studies suggests that cocoa polyphenol consumption may lower the risk of CVD. Given the potential adverse effects of the consumption of cocoa products with high fat and sugar and the fact that the most appropriate dose of cocoa polyphenol for cardio-protective effects has not yet been established, health care providers should remain cautious about recommending cocoa/cocoa polyphenol consumption to their patients to reduce the risk of CVD, taking the characteristics of individual patients into careful consideration. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Association of resting heart rate and cardiovascular disease mortality in hypertensive and normotensive rural Chinese.

PubMed

Zhang, Ming; Han, Chengyi; Wang, Chongjian; Wang, Jinjin; Li, Linlin; Zhang, Lu; Wang, Bingyuan; Ren, Yongcheng; Zhang, Hongyan; Yang, Xiangyu; Zhao, Yang; Zhou, Junmei; Pang, Chao; Yin, Lei; Feng, Tianping; Zhao, Jingzhi; Luo, Xinping; Hu, Dongsheng

2017-05-01

Studies have demonstrated an increased risk of cardiovascular disease (CVD)-associated death (CVD death) with increased resting heart rate (RHR); however, whether the association is consistent in rural Chinese with hypertension and normotension is unknown. We examined the association of RHR and CVD death by hypertension and normotension status in rural Chinese people. Baseline data for 20,069 participants ≥18 years old were collected during July to August of 2007 and July to August of 2008; 17,151 (85.5%) participants were followed up in July to August of 2013 and July to October of 2014. The association of RHR and CVD death was determined by Cox proportional hazards regression. During a mean of 5.88 years (100,889 person-years) of follow-up, we recorded 479 CVD deaths (309 in hypertensive participants). CVD death increased significantly with increasing RHR, beginning from 80 beats per minute (bpm), for hypertensive and normotensive participants. After adjusting for pulse pressure and other covariates, for hypertensive participants, risk of CVD death was increased with RHR 80-89 and ≥90bpm. However, for normotensive participants, risk of CVD death was increased with only RHR≥90bpm. Risk of CVD death was associated with elevated RHR for both hypertensive and normotensive rural Chinese, and for hypertensive participants, even slightly elevated RHR was associated with CVD death. Copyright © 2016 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

Physical Therapists’ Perceptions of Knowledge and Clinical Behavior Regarding Cardiovascular Disease Prevention

PubMed Central

Van Zant, R Scott; Cape, Kelly Jo; Roach, Katrina; Sweeney, Janie

2013-01-01

Purpose The study purpose was to assess perceptions of physical therapists (PTs) regarding the role of physical therapy in cardiovascular disease (CVD) prevention. Methods A 25-item survey, validated by expert cardiovascular/pulmonary (CVP) PTs, was sent electronically to 2,673 PTs. Each item represented an element of clinical practice behavior: education of CVD/risk factors (EDCVD), administration of primary CVD prevention (PRECVD), identifying underlying CVD/risk factors (IDCVD), monitoring CV status in patients with CVD (MONCVD). Responses were assigned numeric values (strongly agree = 5 to strongly disagree = 1), and mean element scores were analyzed. Results Most of the 516 respondents were APTA Section members (34% CVP Section, 42% other Section membership) and worked in academia (53%). Items showing a high (> 95%) level of agreement included patient education of smoking (97%) and monitoring exercise intensity (99%), assessing exercise benefits (99%), clinically identifying obesity (97%) and hypertension (97%), and monitoring CV response to exercise (99%). Items failing to reach 80% overall agreement were patient education of CVD medications (79%) and blood chemistry (72%), and assessing CVD family history (75%), patient BMI (60%), and body composition (33%). Identifying underlying CVD (77.2%) was the only practice behavior failing to reach 80% agreement. Outpatient PTs agreed significantly less to all elements vs. academics, and to IDCVD vs. all PTs except home health. Conclusions Physical therapists support most CVD prevention behaviors, but not given elements of patient education and identifying underlying CVD/risk factors. PMID:23801901

Circulating interleukin-10 and risk of cardiovascular events: a prospective study in the elderly at risk.

PubMed

Welsh, Paul; Murray, Heather M; Ford, Ian; Trompet, Stella; de Craen, Anton J M; Jukema, J Wouter; Stott, David J; McInnes, Iain B; Packard, Chris J; Westendorp, Rudi G J; Sattar, Naveed

2011-10-01

The goal of this study was to examine the association of the antiinflammatory interleukin-10 (IL-10) with risk of cardiovascular disease (CVD). In the PROSPER (PROspective Study of Pravastatin in the Elderly at Risk) cohort, we related baseline concentrations of circulating IL-10 to risk of CVD events in a nested case (n=819)-control (n=1618) study of 3.2 years of follow-up. Circulating IL-10 showed few strong associations with classical risk factors but was positively correlated with IL-6 and C-reactive protein. IL-10 was positively associated with risk of CVD events (odds ratio [OR] 1.17, 95% CI 1.05 to 1.31 per unit increase in log IL-10) after adjusting for classical risk factors and C-reactive protein. Furthermore, IL-10 was associated more strongly with CVD risk among those with no previous history of CVD (OR 1.42, 95% CI 1.18 to 1.70), compared with those with previous CVD (OR 1.04, 95% CI 0.90 to 1.19; P=0.018). Overall, IL-10 showed a modest ability to add discrimination to classical risk factors (C-statistic +0.005, P=0.002). Baseline circulating levels of the antiinflammatory IL-10 are positively associated with risk of CVD among the elderly without prior CVD events, although the association is less evident in those with a history of CVD. Additional epidemiological and mechanistic studies investigating the role of IL-10 in CVD are warranted.

The health effects of US unemployment insurance policy: does income from unemployment benefits prevent cardiovascular disease?

PubMed

Walter, Stefan; Glymour, Maria; Avendano, Mauricio

2014-01-01

Previous studies suggest that unemployment predicts increased cardiovascular disease (CVD) risk, but whether unemployment insurance programs mitigate this risk has not been assessed. Exploiting US state variations in unemployment insurance benefit programs, we tested the hypothesis that more generous benefits reduce CVD risk. Cohort data came from 16,108 participants in the Health and Retirement Study (HRS) aged 50-65 at baseline interviewed from 1992 to 2010. Data on first and recurrent CVD diagnosis assessed through biennial interviews were linked to the generosity of unemployment benefit programmes in each state and year. Using state fixed-effect models, we assessed whether state changes in the generosity of unemployment benefits predicted CVD risk. States with higher unemployment benefits had lower incidence of CVD, so that a 1% increase in benefits was associated with 18% lower odds of CVD (OR:0.82, 95%-CI:0.71-0.94). This association remained after introducing US census regional division fixed effects, but disappeared after introducing state fixed effects (OR:1.02, 95%-CI:0.79-1.31).This was consistent with the fact that unemployment was not associated with CVD risk in state-fixed effect models. Although states with more generous unemployment benefits had lower CVD incidence, this appeared to be due to confounding by state-level characteristics. Possible explanations are the lack of short-term effects of unemployment on CVD risk. Future studies should assess whether benefits at earlier stages of the life-course influence long-term risk of CVD.

Health effects resulting from exercise versus those from body fat loss.

PubMed

Williams, P T

2001-06-01

The purpose of this review was to assess whether body weight confounds the relationships between physical activity and its health benefits. The review includes 80 reports from population-based studies (Evidence Category C) of physical activity or fitness and cardiovascular disease (CVD) or coronary heart disease (CHD). Eleven of 64 reports on activity found no relationship between physical activity and disease. Of the remaining 53 reports, 11 did not address the possible confounding effects of body weight, nine cited reasons that weight differences should not explain their observed associations, and 33 statistically adjusted for weight (as required). Only three of these changed their associations from significant to nonsignificant when adjusted. Ten of 16 reports on cardiorespiratory fitness and CHD or CVD used statistical adjustment, and none of these changed their findings to nonsignificant. Population studies show that vigorously active individuals also have higher high-density lipoprotein (HDL)-cholesterol concentration, a major risk factor for CHD and CVD, than sedentary individuals when statistically adjusted for weight. In contrast, intervention studies, which relate dynamic changes in weight and HDL, suggest that adjustment for weight loss largely eliminates the increase in HDL-cholesterol in sedentary men who begin exercising vigorously. Adjusting the cross-sectional HDL-cholesterol differences for the dynamic effects of weight loss eliminates most of the HDL-cholesterol difference between active and sedentary men. Population studies show that the lower incidence of CHD and CVD and higher HDL of fit, active individuals are not because of lean, healthy individuals choosing to be active (i.e., self-selection bias). Nevertheless, metabolic processed associated weight loss may be primarily responsible for the HDL differences between active and sedentary men, and possibly also their differences in CHD and CVD.

Projected Impact of Salt Restriction on Prevention of Cardiovascular Disease in China: A Modeling Study

PubMed Central

Liu, Jing; Coxson, Pamela G.; Penko, Joanne; Goldman, Lee; Bibbins-Domingo, Kirsten; Zhao, Dong

2016-01-01

Objectives To estimate the effects of achieving China’s national goals for dietary salt (NaCl) reduction or implementing culturally-tailored dietary salt restriction strategies on cardiovascular disease (CVD) prevention. Methods The CVD Policy Model was used to project blood pressure lowering and subsequent downstream prevented CVD that could be achieved by population-wide salt restriction in China. Outcomes were annual CVD events prevented, relative reductions in rates of CVD incidence and mortality, quality-adjusted life-years (QALYs) gained, and CVD treatment costs saved. Results Reducing mean dietary salt intake to 9.0 g/day gradually over 10 years could prevent approximately 197 000 incident annual CVD events [95% uncertainty interval (UI): 173 000–219 000], reduce annual CVD mortality by approximately 2.5% (2.2–2.8%), gain 303 000 annual QALYs (278 000–329 000), and save approximately 1.4 billion international dollars (Int$) in annual CVD costs (Int$; 1.2–1.6 billion). Reducing mean salt intake to 6.0 g/day could approximately double these benefits. Implementing cooking salt-restriction spoons could prevent 183 000 fewer incident CVD cases (153 000–215 000) and avoid Int$1.4 billion in CVD treatment costs annually (1.2–1.7 billion). Implementing a cooking salt substitute strategy could lead to approximately three times the health benefits of the salt-restriction spoon program. More than three-quarters of benefits from any dietary salt reduction strategy would be realized in hypertensive adults. Conclusion China could derive substantial health gains from implementation of population-wide dietary salt reduction policies. Most health benefits from any dietary salt reduction program would be realized in adults with hypertension. PMID:26840409

Predictive Properties of Plasma Amino Acid Profile for Cardiovascular Disease in Patients with Type 2 Diabetes

PubMed Central

Kume, Shinji; Araki, Shin-ichi; Ono, Nobukazu; Shinhara, Atsuko; Muramatsu, Takahiko; Araki, Hisazumi; Isshiki, Keiji; Nakamura, Kazuki; Miyano, Hiroshi; Koya, Daisuke; Haneda, Masakazu; Ugi, Satoshi; Kawai, Hiromichi; Kashiwagi, Atsunori; Uzu, Takashi; Maegawa, Hiroshi

2014-01-01

Prevention of cardiovascular disease (CVD) is an important therapeutic object of diabetes care. This study assessed whether an index based on plasma free amino acid (PFAA) profiles could predict the onset of CVD in diabetic patients. The baseline concentrations of 31 PFAAs were measured with high-performance liquid chromatography-electrospray ionization-mass spectrometry in 385 Japanese patients with type 2 diabetes registered in 2001 for our prospective observational follow-up study. During 10 years of follow-up, 63 patients developed cardiovascular composite endpoints (myocardial infarction, angina pectoris, worsening of heart failure and stroke). Using the PFAA profiles and clinical information, an index (CVD-AI) consisting of six amino acids to predict the onset of any endpoints was retrospectively constructed. CVD-AI levels were significantly higher in patients who did than did not develop CVD. The area under the receiver-operator characteristic curve of CVD-AI (0.72 [95% confidence interval (CI): 0.64–0.79]) showed equal or slightly better discriminatory capacity than urinary albumin excretion rate (0.69 [95% CI: 0.62–0.77]) on predicting endpoints. A multivariate Cox proportional hazards regression analysis showed that the high level of CVD-AI was identified as an independent risk factor for CVD (adjusted hazard ratio: 2.86 [95% CI: 1.57–5.19]). This predictive effect of CVD-AI was observed even in patients with normoalbuminuria, as well as those with albuminuria. In conclusion, these results suggest that CVD-AI based on PFAA profiles is useful for identifying diabetic patients at risk for CVD regardless of the degree of albuminuria, or for improving the discriminative capability by combining it with albuminuria. PMID:24971671

Developing a synthetic national population to investigate the impact of different cardiovascular disease risk management strategies: A derivation and validation study

PubMed Central

Jackson, Rod

2017-01-01

Background Many national cardiovascular disease (CVD) risk factor management guidelines now recommend that drug treatment decisions should be informed primarily by patients’ multi-variable predicted risk of CVD, rather than on the basis of single risk factor thresholds. To investigate the potential impact of treatment guidelines based on CVD risk thresholds at a national level requires individual level data representing the multi-variable CVD risk factor profiles for a country’s total adult population. As these data are seldom, if ever, available, we aimed to create a synthetic population, representing the joint CVD risk factor distributions of the adult New Zealand population. Methods and results A synthetic population of 2,451,278 individuals, representing the actual age, gender, ethnicity and social deprivation composition of people aged 30–84 years who completed the 2013 New Zealand census was generated using Monte Carlo sampling. Each ‘synthetic’ person was then probabilistically assigned values of the remaining cardiovascular disease (CVD) risk factors required for predicting their CVD risk, based on data from the national census national hospitalisation and drug dispensing databases and a large regional cohort study, using Monte Carlo sampling and multiple imputation. Where possible, the synthetic population CVD risk distributions for each non-demographic risk factor were validated against independent New Zealand data sources. Conclusions We were able to develop a synthetic national population with realistic multi-variable CVD risk characteristics. The construction of this population is the first step in the development of a micro-simulation model intended to investigate the likely impact of a range of national CVD risk management strategies that will inform CVD risk management guideline updates in New Zealand and elsewhere. PMID:28384217

Long-term coffee consumption and risk of cardiovascular disease: a systematic review and a dose-response meta-analysis of prospective cohort studies.

PubMed

Ding, Ming; Bhupathiraju, Shilpa N; Satija, Ambika; van Dam, Rob M; Hu, Frank B

2014-02-11

Considerable controversy exists on the association between coffee consumption and cardiovascular disease (CVD) risk. A meta-analysis was performed to assess the dose-response relationship of long-term coffee consumption with CVD risk. PubMed and EMBASE were searched for prospective cohort studies of the relationship between coffee consumption and CVD risk, which included coronary heart disease, stroke, heart failure, and CVD mortality. Thirty-six studies were included with 1 279 804 participants and 36 352 CVD cases. A nonlinear relationship of coffee consumption with CVD risk was identified (P for heterogeneity=0.09, P for trend <0.001, P for nonlinearity <0.001). Compared with the lowest category of coffee consumption (median, 0 cups per day), the relative risk of CVD was 0.95 (95% confidence interval, 0.87-1.03) for the highest category (median, 5 cups per day) category, 0.85 (95% confidence interval, 0.80-0.90) for the second highest category (median, 3.5 cups per day), and 0.89 (95% confidence interval, 0.84-0.94) for the third highest category (median, 1.5 cups per day). Looking at separate outcomes, coffee consumption was nonlinearly associated with both coronary heart disease (P for heterogeneity=0.001, P for trend <0.001, P for nonlinearity <0.001) and stroke (P for heterogeneity=0.07, P for trend <0.001, P for nonlinearity <0.001; P for trend differences >0.05) risks. A nonlinear association between coffee consumption and CVD risk was observed in this meta-analysis. Moderate coffee consumption was inversely significantly associated with CVD risk, with the lowest CVD risk at 3 to 5 cups per day, and heavy coffee consumption was not associated with elevated CVD risk.

Cardiorespiratory Fitness Cutoff Points for Early Detection of Present and Future Cardiovascular Risk in Children: A 2-Year Follow-up Study.

PubMed

Castro-Piñero, José; Perez-Bey, Alejandro; Segura-Jiménez, Víctor; Aparicio, Virginia A; Gómez-Martínez, Sonia; Izquierdo-Gomez, Rocio; Marcos, Ascensión; Ruiz, Jonatan R

2017-12-01

To examine the association between cardiorespiratory fitness (CRF) at baseline and cardiovascular disease (CVD) risk in 6- to 10-year-olds (cross-sectional) and 2 years later (8- to 12-year-olds [longitudinal]) and whether changes with age in CRF are associated with CVD risk in children aged 8 to 12 years. Spanish primary schoolchildren (n=236) aged 6 to 10 years participated at baseline. Of the 23 participating primary schools, 22% (n=5) were private schools and 78% (n=18) were public schools. The dropout rate at 2-year follow-up was 9.7% (n=23). The 20-m shuttle run test was used to estimate CRF. The CVD risk score was computed as the mean of 5 CVD risk factor standardized scores: sum of 2 skinfolds, systolic blood pressure, insulin/glucose, triglycerides, and total cholesterol/high-density lipoprotein cholesterol. At baseline, CRF was inversely associated with single CVD risk factors (all P<.05) and CVD risk score at baseline and follow-up (P<.001). Cardiorespiratory fitness cutoff points of 39.0 mL/kg per minute or greater in boys and 37.5 mL/kg per minute or greater in girls are discriminative to identify CVD risk in childhood (area under the curve, >0.85; P<.001) and to predict CVD risk 2 years later (P=.004). Persistent low CRF or the decline of CRF from 6-10 to 8-12 years of age is associated with increased CVD risk at age 8 to 12 years (P<.001). During childhood, CRF is a strong predictor of CVD risk and should be monitored to identify children with potential CVD risk. Copyright © 2017 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

Impact of Renal Impairment on Cardiovascular Disease Mortality After Liver Transplantation for Nonalcoholic Steatohepatitis Cirrhosis

PubMed Central

VanWagner, Lisa B.; Lapin, Brittany; Skaro, Anton I.; Lloyd-Jones, Donald M.; Rinella, Mary E.

2016-01-01

BACKGROUND & AIMS Non-alcoholic steatohepatitis (NASH) is an independent risk factor for cardiovascular disease (CVD) morbidity after liver transplantation, but its impact on CVD mortality is unknown. We sought to assess the impact of NASH on CVD mortality after liver transplantation and to predict which NASH recipients are at highest risk of a CVD-related death following a liver transplant. METHODS Using the Organ Procurement and Transplantation Network database we examined associations between NASH and post liver transplant CVD mortality, defined as primary cause of death from thromboembolism, arrhythmia, heart failure, myocardial infarction, or stroke. A physician panel reviewed cause of death. RESULTS Of 48,360 liver transplants (2/2002–12/2011), 5,057 (10.5%) were performed for NASH cirrhosis. NASH recipients were more likely to be older, female, obese, diabetic, and have history of renal failure or prior CVD versus non-NASH (p<0.001 for all). Although there was no difference in overall all-cause mortality (log-rank p=0.96), both early (30-day) and long-term CVD-specific mortality was increased among NASH recipients (Odds ratio=1.30, 95% Confidence interval (CI): 1.02–1.66; Hazard ratio=1.42, 95% CI: 1.07–1.41, respectively). These associations were no longer significant after adjustment for pre-transplant diabetes, renal impairment or CVD. A risk score comprising age ≥ 55, male sex, diabetes and renal impairment was developed for prediction of post liver transplant CVD mortality (c-statistic 0.60). CONCLUSION NASH recipients have an increased risk of CVD mortality after liver transplantation explained by a high prevalence of co-morbid cardiometabolic risk factors that in aggregate identify those at highest risk of post-transplant CVD mortality. PMID:25977117

Left Ventricular Structure and Risk of Cardiovascular Events: A Framingham Heart Study Cardiac Magnetic Resonance Study

PubMed Central

Tsao, Connie W; Gona, Philimon N; Salton, Carol J; Chuang, Michael L; Levy, Daniel; Manning, Warren J; O’Donnell, Christopher J

2015-01-01

Background Elevated left ventricular mass index (LVMI) and concentric left ventricular (LV) remodeling are related to adverse cardiovascular disease (CVD) events. The predictive utility of LV concentric remodeling and LV mass in the prediction of CVD events is not well characterized. Methods and Results Framingham Heart Study Offspring Cohort members without prevalent CVD (n=1715, 50% men, aged 65±9 years) underwent cardiovascular magnetic resonance for LVMI and geometry (2002–2006) and were prospectively followed for incident CVD (myocardial infarction, coronary insufficiency, heart failure, stroke) or CVD death. Over 13 808 person-years of follow-up (median 8.4, range 0.0 to 10.5 years), 85 CVD events occurred. In multivariable-adjusted proportional hazards regression models, each 10-g/m2 increment in LVMI and each 0.1 unit in relative wall thickness was associated with 33% and 59% increased risk for CVD, respectively (P=0.004 and P=0.009, respectively). The association between LV mass/LV end-diastolic volume and incident CVD was borderline significant (P=0.053). Multivariable-adjusted risk reclassification models showed a modest improvement in CVD risk prediction with the incorporation of cardiovascular magnetic resonance LVMI and measures of LV concentricity (C-statistic 0.71 [95% CI 0.65 to 0.78] for the model with traditional risk factors only, improved to 0.74 [95% CI 0.68 to 0.80] for the risk factor model additionally including LVMI and relative wall thickness). Conclusions Among adults free of prevalent CVD in the community, greater LVMI and LV concentric hypertrophy are associated with a marked increase in adverse incident CVD events. The potential benefit of aggressive primary prevention to modify LV mass and geometry in these adults requires further investigation. PMID:26374295

Developing a synthetic national population to investigate the impact of different cardiovascular disease risk management strategies: A derivation and validation study.

PubMed

Knight, Josh; Wells, Susan; Marshall, Roger; Exeter, Daniel; Jackson, Rod

2017-01-01

Many national cardiovascular disease (CVD) risk factor management guidelines now recommend that drug treatment decisions should be informed primarily by patients' multi-variable predicted risk of CVD, rather than on the basis of single risk factor thresholds. To investigate the potential impact of treatment guidelines based on CVD risk thresholds at a national level requires individual level data representing the multi-variable CVD risk factor profiles for a country's total adult population. As these data are seldom, if ever, available, we aimed to create a synthetic population, representing the joint CVD risk factor distributions of the adult New Zealand population. A synthetic population of 2,451,278 individuals, representing the actual age, gender, ethnicity and social deprivation composition of people aged 30-84 years who completed the 2013 New Zealand census was generated using Monte Carlo sampling. Each 'synthetic' person was then probabilistically assigned values of the remaining cardiovascular disease (CVD) risk factors required for predicting their CVD risk, based on data from the national census national hospitalisation and drug dispensing databases and a large regional cohort study, using Monte Carlo sampling and multiple imputation. Where possible, the synthetic population CVD risk distributions for each non-demographic risk factor were validated against independent New Zealand data sources. We were able to develop a synthetic national population with realistic multi-variable CVD risk characteristics. The construction of this population is the first step in the development of a micro-simulation model intended to investigate the likely impact of a range of national CVD risk management strategies that will inform CVD risk management guideline updates in New Zealand and elsewhere.

Long-Term Coffee Consumption and Risk of Cardiovascular Disease: A Systematic Review and a Dose-Response Meta-Analysis of Prospective Cohort Studies

PubMed Central

Ding, Ming; Bhupathiraju, Shilpa N; Satija, Ambika; van Dam, Rob M; Hu, Frank B

2013-01-01

Background Considerable controversy exists regarding the association between coffee consumption and cardiovascular disease (CVD) risk. A meta-analysis was performed to assess the dose-response relationship of long-term coffee consumption with CVD risk. Methods and Results Pubmed and EMBASE were searched for prospective cohort studies of the relationship between coffee consumption and CVD risk, which included coronary heart disease, stroke, heart failure, and CVD mortality. Thirty-six studies were included with 1,279,804 participants and 36,352 CVD cases. A non-linear relationship of coffee consumption with CVD risk was identified (P for heterogeneity = 0.09, P for trend < 0.001, P for non-linearity < 0.001). Compared with the lowest category of coffee consumption (median: 0 cups/d), the relative risk of CVD was 0.95 (95% CI, 0.87 to 1.03) for the highest (median: 5 cups/d) category, 0.85 (0.80 to 0.90) for the second highest (median: 3.5 cups/d), and 0.89 (0.84 to 0.94) for the third highest category (median: 1.5 cups/d). Looking at separate outcomes, coffee consumption was non-linearly associated with both CHD (P for heterogeneity = 0.001, P for trend < 0.001, P for non-linearity < 0.001) and stroke risks (P for heterogeneity = 0.07, P for trend < 0.001, P for non-linearity< 0.001) (P for trend differences > 0.05). Conclusions A non-linear association between coffee consumption with CVD risk was observed in this meta-analysis. Moderate coffee consumption was inversely significantly associated with CVD risk, with the lowest CVD risk at 3 to 5 cups/d, and heavy coffee consumption was not associated with elevated CVD risk. PMID:24201300

Outdoor temperature, blood pressure, and cardiovascular disease mortality among 23 000 individuals with diagnosed cardiovascular diseases from China.

PubMed

Yang, Ling; Li, Liming; Lewington, Sarah; Guo, Yu; Sherliker, Paul; Bian, Zheng; Collins, Rory; Peto, Richard; Liu, Yun; Yang, Rong; Zhang, Yongrui; Li, Guangchun; Liu, Shumei; Chen, Zhengming

2015-05-14

Blood pressure is a major cause of cardiovascular disease (CVD) and both may increase as outdoor temperatures fall. However, there are still limited data about seasonal variation in blood pressure and CVD mortality among patients with prior-CVD. We analysed data on 23 000 individuals with prior-CVD who were recruited from 10 diverse regions into the China Kadoorie Biobank during 2004-8. After 7 years of follow-up, 1484 CVD deaths were recorded. Baseline survey data were used to assess seasonal variation in systolic blood pressure (SBP) and its association with outdoor temperature. Cox regression was used to examine the association of usual SBP with subsequent CVD mortality, and seasonal variation in CVD mortality was assessed by Poisson regression. All analyses were adjusted for age, sex, and region. Mean SBP was significantly higher in winter than in summer (145 vs. 136 mmHg, P < 0.001), especially among those without central heating. Above 5°C, each 10°C lower outdoor temperature was associated with 6.2 mmHg higher SBP. Systolic blood pressure predicted subsequent CVD mortality, with each 10 mmHg higher usual SBP associated with 21% (95% confidence interval: 16-27%) increased risk. Cardiovascular disease mortality varied by season, with 41% (21-63%) higher risk in winter compared with summer. Among adult Chinese with prior-CVD, there is both increased blood pressure and CVD mortality in winter. Careful monitoring and more aggressive blood pressure lowering treatment in the cold months are needed to help reduce the winter excess CVD mortality in high-risk individuals. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Cardiology.