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Sample records for absolute cvd risk

  1. Nutrition and CVD risk

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is a wide range of dietary approaches purported to decrease the risk of developing cardiovascular disease (CVD). Some were first identified early in the 20th century whereas others have been recognized more recently. Some have stood the test of time and others have not. None are without contro...

  2. Comparative assessment of absolute cardiovascular disease risk characterization from non-laboratory-based risk assessment in South African populations

    PubMed Central

    2013-01-01

    Background All rigorous primary cardiovascular disease (CVD) prevention guidelines recommend absolute CVD risk scores to identify high- and low-risk patients, but laboratory testing can be impractical in low- and middle-income countries. The purpose of this study was to compare the ranking performance of a simple, non-laboratory-based risk score to laboratory-based scores in various South African populations. Methods We calculated and compared 10-year CVD (or coronary heart disease (CHD)) risk for 14,772 adults from thirteen cross-sectional South African populations (data collected from 1987 to 2009). Risk characterization performance for the non-laboratory-based score was assessed by comparing rankings of risk with six laboratory-based scores (three versions of Framingham risk, SCORE for high- and low-risk countries, and CUORE) using Spearman rank correlation and percent of population equivalently characterized as ‘high’ or ‘low’ risk. Total 10-year non-laboratory-based risk of CVD death was also calculated for a representative cross-section from the 1998 South African Demographic Health Survey (DHS, n = 9,379) to estimate the national burden of CVD mortality risk. Results Spearman correlation coefficients for the non-laboratory-based score with the laboratory-based scores ranged from 0.88 to 0.986. Using conventional thresholds for CVD risk (10% to 20% 10-year CVD risk), 90% to 92% of men and 94% to 97% of women were equivalently characterized as ‘high’ or ‘low’ risk using the non-laboratory-based and Framingham (2008) CVD risk score. These results were robust across the six risk scores evaluated and the thirteen cross-sectional datasets, with few exceptions (lower agreement between the non-laboratory-based and Framingham (1991) CHD risk scores). Approximately 18% of adults in the DHS population were characterized as ‘high CVD risk’ (10-year CVD death risk >20%) using the non-laboratory-based score. Conclusions We found a high level of

  3. Changes in CVD risk factors in the activity counseling trial

    PubMed Central

    Baruth, Meghan; Wilcox, Sara; Sallis, James F; King, Abby C; Marcus, Bess H; Blair, Steven N

    2011-01-01

    Primary care facilities may be a natural setting for delivering interventions that focus on behaviors that improve cardiovascular disease (CVD) risk factors. The purpose of this study was to examine the 24-month effects of the Activity Counseling Trial (ACT) on CVD risk factors, to examine whether changes in CVD risk factors differed according to baseline risk factor status, and to examine whether changes in fitness were associated with changes in CVD risk factors. ACT was a 24-month multicenter randomized controlled trial to increase physical activity. Participants were 874 inactive men and women aged 35–74 years. Participants were randomly assigned to one of three arms that varied by level of counseling, intensity, and resource requirements. Because there were no significant differences in change over time between arms on any of the CVD risk factors examined, all arms were combined, and the effects of time, independent of arm, were examined separately for men and women. Time × Baseline risk factor status interactions examined whether changes in CVD risk factors differed according to baseline risk factor status. Significant improvements in total cholesterol, high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol, the ratio of total cholesterol to HDL-C, and triglycerides were seen in both men and women who had high (or low for HDL-C) baseline levels of risk factors, whereas significant improvements in diastolic blood pressure were seen only in those men with high baseline levels. There were no improvements in any risk factors among participants with normal baseline levels. Changes in fitness were associated with changes in a number of CVD risk factors. However, most relationships disappeared after controlling for changes in body weight. Improvements in lipids from the ACT interventions could reduce the risk of coronary heart disease in people with already high levels of lipids by 16%–26% in men and 11%–16% in women

  4. Underestimating risk in women delays diagnosis of CVD.

    PubMed

    Keteepe-Arachi, Tracey; Sharma, Sanjay

    2016-03-01

    CVD remains the most common cause of mortality in women. In 2007, the annual mortality in women secondary to CAD was 4.7 times that of breast cancer. Around 2.8 million women are living with CVD in the UK. There has been an increase in the prevalence of MI in women aged 35 to 54, while a decline in prevalence was observed in age-matched men. Difficulty in evaluating symptoms of ischaemic heart disease in women is well documented and remains challenging because of their atypical nature. The main gender difference is that women tend to present less frequently with exertional symptoms of chest pain before an AMI. Although men and women share classic cardiovascular risk factors the relative importance of each risk factor may be gender specific. The impact of smoking is greater in women than men, especially in those under 50. Diabetes is a more potent risk factor for fatal CHD in women than men. Risk factors specific to women include postmenopausal status, hysterectomy and complications during pregnancy. Women who develop gestational diabetes mellitus or pre-eclampsia more than double their risk of CVD later in life. Transition to the menopause is associated with a worsening CHD risk profile. After the menopause women may experience an increase in weight, alteration in fat distribution and an increase in other CVD risk factors such as diabetes and a more adverse lipid profile. Pharmacological stress testing is preferred for diagnosing CAD in females with lower exercise capacity. Stress cardiomyopathy is triggered by intense, unexpected emotional or physical stress and is characterised by transient apical systolic dysfunction or ballooning of the left ventricle. The syndrome predominantly affects postmenopausal women. Women presenting with STEMI have worse outcomes compared with men. However, in those presenting with NSTEMI there were no differences in outcomes. PMID:27214974

  5. Blood pressure targets and absolute cardiovascular risk.

    PubMed

    Odutayo, Ayodele; Rahimi, Kazem; Hsiao, Allan J; Emdin, Connor A

    2015-08-01

    In the Eighth Joint National Committee guideline on hypertension, the threshold for the initiation of blood pressure-lowering treatment for elderly adults (≥60 years) without chronic kidney disease or diabetes mellitus was raised from 140/90 mm Hg to 150/90 mm Hg. However, the committee was not unanimous in this decision, particularly because a large proportion of adults ≥60 years may be at high cardiovascular risk. On the basis of Eighth Joint National Committee guideline, we sought to determine the absolute 10-year risk of cardiovascular disease among these adults through analyzing the National Health and Nutrition Examination Survey (2005-2012). The primary outcome measure was the proportion of adults who were at ≥20% predicted absolute cardiovascular risk and above goals for the Seventh Joint National Committee guideline but reclassified as at target under the Eighth Joint National Committee guideline (reclassified). The Framingham General Cardiovascular Disease Risk Score was used. From 2005 to 2012, the surveys included 12 963 adults aged 30 to 74 years with blood pressure measurements, of which 914 were reclassified based on the guideline. Among individuals reclassified as not in need of additional treatment, the proportion of adults 60 to 74 years without chronic kidney disease or diabetes mellitus at ≥20% absolute risk was 44.8%. This corresponds to 0.8 million adults. The proportion at high cardiovascular risk remained sizable among adults who were not receiving blood pressure-lowering treatment. Taken together, a sizable proportion of reclassified adults 60 to 74 years without chronic kidney disease or diabetes mellitus was at ≥20% absolute cardiovascular risk. PMID:26056340

  6. COMPARATIVE EVALUATION OF RISK FACTORS FOR CARDIOVASCULAR DISEASE (CVD) IN GENETICALLY PREDISPOSED RATS

    EPA Science Inventory

    Rodent CVD models are increasingly used for understanding individual differences in susceptibility to environmental stressors such as air pollution. We characterized pathologies and a number of known human risk factors of CVD in genetically predisposed, male young adult Spontaneo...

  7. Effects of Light Intensity Activity on CVD Risk Factors: A Systematic Review of Intervention Studies

    PubMed Central

    Batacan, Romeo B.; Duncan, Mitch J.; Dalbo, Vincent J.; Tucker, Patrick S.; Fenning, Andrew S.

    2015-01-01

    The effects of light intensity physical activity (LIPA) on cardiovascular disease (CVD) risk factors remain to be established. This review summarizes the effects of LIPA on CVD risk factors and CVD-related markers in adults. A systematic search of four electronic databases (PubMed, Academic Search Complete, SPORTDiscus, and CINAHL) examining LIPA and CVD risk factors (body composition, blood pressure, glucose, insulin, glycosylated hemoglobin, and lipid profile) and CVD-related markers (maximal oxygen uptake, heart rate, C-reactive protein, interleukin-6, tumor necrosis factor-alpha, and tumor necrosis factor receptors 1 and 2) published between 1970 and 2015 was performed on 15 March 2015. A total of 33 intervention studies examining the effect of LIPA on CVD risk factors and markers were included in this review. Results indicated that LIPA did not improve CVD risk factors and CVD-related markers in healthy individuals. LIPA was found to improve systolic and diastolic blood pressure in physically inactive populations with a medical condition. Reviewed studies show little support for the role of LIPA to reduce CVD risk factors. Many of the included studies were of low to fair study quality and used low doses of LIPA. Further studies are needed to establish the value of LIPA in reducing CVD risk. PMID:26543862

  8. Effects of Light Intensity Activity on CVD Risk Factors: A Systematic Review of Intervention Studies.

    PubMed

    Batacan, Romeo B; Duncan, Mitch J; Dalbo, Vincent J; Tucker, Patrick S; Fenning, Andrew S

    2015-01-01

    The effects of light intensity physical activity (LIPA) on cardiovascular disease (CVD) risk factors remain to be established. This review summarizes the effects of LIPA on CVD risk factors and CVD-related markers in adults. A systematic search of four electronic databases (PubMed, Academic Search Complete, SPORTDiscus, and CINAHL) examining LIPA and CVD risk factors (body composition, blood pressure, glucose, insulin, glycosylated hemoglobin, and lipid profile) and CVD-related markers (maximal oxygen uptake, heart rate, C-reactive protein, interleukin-6, tumor necrosis factor-alpha, and tumor necrosis factor receptors 1 and 2) published between 1970 and 2015 was performed on 15 March 2015. A total of 33 intervention studies examining the effect of LIPA on CVD risk factors and markers were included in this review. Results indicated that LIPA did not improve CVD risk factors and CVD-related markers in healthy individuals. LIPA was found to improve systolic and diastolic blood pressure in physically inactive populations with a medical condition. Reviewed studies show little support for the role of LIPA to reduce CVD risk factors. Many of the included studies were of low to fair study quality and used low doses of LIPA. Further studies are needed to establish the value of LIPA in reducing CVD risk. PMID:26543862

  9. Is the risk and nature of CVD the same in type 1 and type 2 diabetes?

    PubMed

    Duca, Lindsey; Sippl, Rachel; Snell-Bergeon, Janet K

    2013-06-01

    The incidence of both type 1 and type 2 diabetes is increasing globally, most likely explained by environmental changes, such as changing exposures to foods, viruses, and toxins, and by increasing obesity. While cardiovascular disease (CVD) mortality has been declining recently, this global epidemic of diabetes threatens to stall this trend. CVD is the leading cause of death in both type 1 and type 2 diabetes, with at least a two- to fourfold increased risk in patients with diabetes. In this review, the risk factors for CVD are discussed in the context of type 1 and type 2 diabetes. While traditional risk factors such as dyslipidemia, hypertension, and obesity are greater in type 2 patients than in type 1 diabetes, they explain only about half of the increased CVD risk. The role for diabetes-specific risk factors, including hyperglycemia and kidney complications, is discussed in the context of new study findings. PMID:23519720

  10. Applicability of the Existing CVD Risk Assessment Tools to Type II Diabetics in Oman: A Review

    PubMed Central

    Al-Rawahi, Abdulhakeem; Lee, Patricia

    2015-01-01

    Patients with type II diabetes (T2DM) have an elevated risk for cardiovascular disease (CVD), and it is considered to be a leading cause of morbidity and premature mortality in these patients. Many traditional risk factors such as age, male sex, hypertension, dyslipidemia, glycemic control, diabetes duration, renal dysfunction, obesity, and smoking have been studied and identified as independent factors for CVD. Quantifying the risk of CVD among diabetics using the common risk factors in order to plan the treatment and preventive measures is important in the management of these patients as recommended by many clinical guidelines. Therefore, several risk assessment tools have been developed in different parts of the world for this purpose. These include the tools that have been developed for general populations and considered T2DM as a risk factor, and the tools that have been developed for T2DM populations specifically. However, due to the differences in sociodemographic factors and lifestyle patterns, as well as the differences in the distribution of various CVD risk factors in different diabetic populations, the external applicability of these tools on different populations is questionable. This review aims to address the applicability of the existing CVD risk models to the Omani diabetic population. PMID:26421110

  11. Linkage Mapping of CVD Risk Traits in the Isolated Norfolk Island Population

    PubMed Central

    Bellis, C.; Cox, H.C; Dyer, T. D.; Charlesworth, J. C.; Begley, K.N; Quinlan, S.; Lea, R.A; Heath, S.C; Blangero, J.; Griffiths, L.R

    2009-01-01

    To understand the underlying genetic architecture of cardiovascular disease (CVD) risk traits, we undertook a genome-wide linkage scan to identify CVD quantitative trait loci (QTLs) in 377 individuals from the Norfolk Island population. The central aim of this research focused on the utilization of a genetically and geographically isolated population of individuals from Norfolk Island for the purposes of variance component linkage analysis to identify QTLs involved in CVD risk traits. Substantial evidence supports the involvement of traits such as systolic and diastolic blood pressures (SBP and DBP), high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C), body mass index (BMI) and triglycerides (TG) as important risk factors for CVD pathogenesis. In addition to the environmental influences of poor diet, reduced physical activity, increasing age, cigarette smoking and alcohol consumption, many studies have illustrated a strong involvement of genetic components in the CVD phenotype through family and twin studies. We undertook a genome scan using 400 markers spaced approximately 10cM in 600 individuals from Norfolk Island. Genotype data was analyzed using the variance components methods of SOLAR. Our results gave a peak LOD score of 2.01 localizing to chromosome 1p36 for systolic blood pressure and replicated previously implicated loci for other CVD relevant QTLs. PMID:18975005

  12. Population-based absolute risk estimation with survey data.

    PubMed

    Kovalchik, Stephanie A; Pfeiffer, Ruth M

    2014-04-01

    Absolute risk is the probability that a cause-specific event occurs in a given time interval in the presence of competing events. We present methods to estimate population-based absolute risk from a complex survey cohort that can accommodate multiple exposure-specific competing risks. The hazard function for each event type consists of an individualized relative risk multiplied by a baseline hazard function, which is modeled nonparametrically or parametrically with a piecewise exponential model. An influence method is used to derive a Taylor-linearized variance estimate for the absolute risk estimates. We introduce novel measures of the cause-specific influences that can guide modeling choices for the competing event components of the model. To illustrate our methodology, we build and validate cause-specific absolute risk models for cardiovascular and cancer deaths using data from the National Health and Nutrition Examination Survey. Our applications demonstrate the usefulness of survey-based risk prediction models for predicting health outcomes and quantifying the potential impact of disease prevention programs at the population level. PMID:23686614

  13. Absolute Risk Aversion and the Returns to Education.

    ERIC Educational Resources Information Center

    Brunello, Giorgio

    2002-01-01

    Uses 1995 Italian household income and wealth survey to measure individual absolute risk aversion of 1,583 married Italian male household heads. Uses this measure as an instrument for attained education in a standard-log earnings equation. Finds that the IV estimate of the marginal return to schooling is much higher than the ordinary least squares…

  14. Blood glucose may be an alternative to cholesterol in CVD risk prediction charts

    PubMed Central

    2013-01-01

    Background Established risk models for the prediction of cardiovascular disease (CVD) include blood pressure, smoking and cholesterol parameters. The use of total cholesterol for CVD risk prediction has been questioned, particularly for primary prevention. We evaluated whether glucose could be used instead of total cholesterol for prediction of fatal CVD using data with long follow-up. Methods We followed-up 6,095 men and women aged ≥16 years who participated 1977-79 in a community based health study and were anonymously linked with the Swiss National Cohort until the end of 2008. During follow-up, 727 participants died of CVD. Based on the ESC SCORE methodology (Weibull regression), we used age, sex, blood pressure, smoking, and fasting glucose or total cholesterol. The mean Brier score (BS), area under the receiver-operating characteristic curve (AUC) and integrated discrimination improvement (IDI) were used for model comparison. We validated our models internally using cross-validation and externally using another data set. Results In our models, the p-value of total cholesterol was 0.046, that of glucose was p < 0.001. The model with glucose had a slightly better predictive capacity (BS: 2216x10-5 vs. 2232x10-5; AUC: 0.9181 vs. 0.9169, IDI: 0.009 with p-value 0.026) and could well discriminate the overall risk of persons with high and low concentrations. The external validation confirmed these findings. Conclusions Our study suggests that instead of total cholesterol glucose can be used in models predicting overall CVD mortality risk. PMID:23351551

  15. Development of Health Parameter Model for Risk Prediction of CVD Using SVM

    PubMed Central

    Unnikrishnan, P.; Kumar, H.; Mitchell, P.; Kawasaki, R.

    2016-01-01

    Current methods of cardiovascular risk assessment are performed using health factors which are often based on the Framingham study. However, these methods have significant limitations due to their poor sensitivity and specificity. We have compared the parameters from the Framingham equation with linear regression analysis to establish the effect of training of the model for the local database. Support vector machine was used to determine the effectiveness of machine learning approach with the Framingham health parameters for risk assessment of cardiovascular disease (CVD). The result shows that while linear model trained using local database was an improvement on Framingham model, SVM based risk assessment model had high sensitivity and specificity of prediction of CVD. This indicates that using the health parameters identified using Framingham study, machine learning approach overcomes the low sensitivity and specificity of Framingham model. PMID:27594895

  16. Development of Health Parameter Model for Risk Prediction of CVD Using SVM.

    PubMed

    Unnikrishnan, P; Kumar, D K; Poosapadi Arjunan, S; Kumar, H; Mitchell, P; Kawasaki, R

    2016-01-01

    Current methods of cardiovascular risk assessment are performed using health factors which are often based on the Framingham study. However, these methods have significant limitations due to their poor sensitivity and specificity. We have compared the parameters from the Framingham equation with linear regression analysis to establish the effect of training of the model for the local database. Support vector machine was used to determine the effectiveness of machine learning approach with the Framingham health parameters for risk assessment of cardiovascular disease (CVD). The result shows that while linear model trained using local database was an improvement on Framingham model, SVM based risk assessment model had high sensitivity and specificity of prediction of CVD. This indicates that using the health parameters identified using Framingham study, machine learning approach overcomes the low sensitivity and specificity of Framingham model. PMID:27594895

  17. Application of two versions of the WHO/international society of hypertension absolute cardiovascular risk assessment tools in a rural Bangladeshi population

    PubMed Central

    Fatema, Kaniz; Zwar, Nicholas Arnold; Milton, Abul Hasnat; Rahman, Bayzidur; Ali, Liaquat

    2015-01-01

    Objectives To estimate the absolute cardiovascular disease (CVD) risk burden in a remote rural Bangladeshi population using the ‘With’ and ‘Without’ Cholesterol versions of the WHO/International Society of Hypertension (WHO/ISH) CVD risk assessment chart (particularly suitable for low and middle-income countries due to less reliance on laboratory testing) and to evaluate the agreement between the two approaches. Design Cross-sectional study using data from a large prospective cohort of the North Bengal Non-Communicable Disease Programme (NB-NCDP) of Bangladesh. Setting General rural population from Thakurgaon district of Bangladesh. Participants 563 individuals who were categorised as having ‘no CVDs’ on screening by a questionnaire-based survey using the ‘WHO CVD-Risk Management Package’ developed in 2002. Main outcome measures Absolute CVD risk burden assessed using two versions of the WHO/ISH risk assessment charts for the South-East Asian Region-D. Results 10-year risk (moderate, high and very high) positivity was present among 21.5% and 20.2% of participants, respectively, using with and without cholesterol versions of the tool. The overall concordance rate for the two versions was 89.5% and they did not differ significantly in estimating the proportion of overall participants having higher levels of CVD. The projected drug requirement, however, showed a significant overestimation in the proportion of participants at both the threshold levels (p<0.002) on using ‘without’ as compared to ‘with’ cholesterol versions. Conclusions About one-fifth of the adult population in Bangladesh, even in a remote rural area, seem to be at risk of developing CVDs (25% of them at high risk and 25% at very high risk) within 10 years with males and females being almost equally vulnerable. PMID:26463220

  18. Relationship between early growth and CVD risk factors in adolescents.

    PubMed

    Musa, M G; Kagura, J; Pisa, P T; Norris, S A

    2016-04-01

    Low birth weight and a rapid weight gain in early childhood may lead to an increased risk for developing cardiovascular disease later in life, such as hypertension and dyslipidaemia. In this study, we examined the associations between size at birth, relative weight gain in infancy and childhood with specific cardiovascular disease risk factors in early adulthood. Adolescents (n=1935) from the Birth to Twenty plus (BT20+) cohort were included in the analysis. The following were treated as exposure variables: weight at birth, and relative conditional weight gain (CW), independent of height, between ages 0-24 months and 24-48 months. Outcomes were serum lipids and body composition variables at age 18 years. After adjusting for sex and other confounders, early life exposures were not associated with adolescent lipid profile. Following adjustment for sex and height (body size), birth weight [β=0.704 (0.40, 1.01)], CW 0-24 [β=1.918 (1.56, 2.28)] and CW24-48 [β=1.485 (1.14, 1.82)] accounted for 48% of the variance in fat mass. However, birth weight [β=0.773 (0.54, 1.01)], CW 0-24 [β=1.523 (1.24, 1.80)] and CW24-48 [β=1.226 (0.97, 1.49)] were also positively predicted and accounted for 71% of the variance in fat mass in adolescence (P<0.05). Our data suggests that birth weight and weight gain during infancy and early childhood independent of linear growth are related to adolescent body composition but not blood lipid profiles in an urban African population. PMID:26810380

  19. Early community contexts, race/ethnicity and young adult CVD risk factors: the protective role of education.

    PubMed

    Wickrama, K A S; O'Neal, Catherine Walker; Lott, Ryan E

    2012-08-01

    Using a sample of 13,500 adolescents (53% female and 47% male) who participated in all four waves of the National Longitudinal Study of Adolescent Health, this study used multilevel regression to examine the influence of early structural community adversity (as measured by rates of community poverty, single-parent headed families, and two indicators of employment) and racial/ethnic status on cardiovascular disease (CVD) risk factors of young adults (systolic blood pressure, diastolic blood pressure, and mean arterial pressure). The moderating role of youth's socioeconomic attainment was also examined. Results indicate that early community adversity and African American racial status place young adults at risk for CVD. Youth's socioeconomic attainment does not erase the persistent influences of early community adversity and African American racial status on CVD risk. However, the level of education attained can protect African American young adults and those experiencing early community adversity from CVD risk factors. PMID:22101680

  20. Vitamin D and risk of CVD: a review of the evidence.

    PubMed

    Fry, Catherine M; Sanders, Thomas A B

    2015-08-01

    This review summarises evidence for an association between vitamin D status and CVD and the mechanisms involved. Vitamin D3 is predominantly provided by the action of UVB from sunlight on skin. Average UK diets supply 2-3 μg/d vitamin D but diets containing at least one portion of oily fish per week supply about 7 μg/d. Pharmacological doses of vitamin D2 (bolus injection of 7500 μg or intakes >50 μg/d) result in a smaller increase in plasma 25(OH)D than those of D3 but physiological doses 5-25 μg/d seem equivalent. Plasma 25(OH)D concentrations are also influenced by clothing, obesity and skin pigmentation. Up to 40 % of the population have plasma 25(OH)D concentrations <25 nmol/l in the winter compared with <10 % in the summer. The relative risk of CVD death is 1·41 (95 % CI 1·18, 1·68) greater in the lowest quintile of plasma 25(OH)D according to meta-analysis of prospective cohort studies. Acute deficiency may inhibit insulin secretion and promote inflammation thus increasing the risk of plaque rupture and arterial thrombosis. Chronic insufficiency may increase arterial stiffness. There is no evidence to support claims of reduced CVD from existing trials with bone-related health outcomes where vitamin D was usually co-administered with calcium. Although several trials with cardiovascular endpoints are in progress, these are using pharmacological doses. In view of the potential toxicity of pharmacological doses, there remains a need for long-term trials of physiological doses of D2 and D3 with CVD incidence as the primary outcome. PMID:25697289

  1. Joint association of physical activity/screen time and diet on CVD risk factors in 10-year-old children.

    PubMed

    Drenowatz, Clemens; Carlson, Joseph J; Pfeiffer, Karin A; Eisenmann, Joey C

    2012-12-01

    The increasing prevalence of childhood overweight and obesity has been associated with an increased risk for cardiovascular disease (CVD). While several studies examined the effect of single behaviors such as physical activity (PA), sedentary behavior or diet on CVD risk, there is a lack of research on combined associations, specifically in children. Therefore, the purpose of this study was to examine the joint association of PA or screen time (ST) and diet on CVD risk factors in children. PA, STand diet were assessed via questionnaire in 210 fifth grade students (age: 10.6 ± 0.4 years). The healthy eating index (HEI) was subsequently calculated as indicator for diet quality. Height, weight, % body fat, and resting blood pressure were measured according to standard procedures and blood samples obtained via fingerprick were assayed for blood lipids. Total cholesterol HDL ratio (TC:HDL), mean arterial pressure (MAP), and % body fat were used as indicators of CVD risk. 55% of children did not meet current PA recommendations on at least 5 days/week and 70% exceeded current recommendations for ST. Further, only 2.5% possessed a "good" diet (HEI> 80). There was no significant association of PA or STand diet on CVD risk score. Neither TC:HDL, MAP, and % body fat nor the total CVD risk score was significantly correlated with diet, PA, or ST. Children in the high PA group, however, had significantly better diet scores. Despite the fact that self-reported PA, ST, or dietary intake were not directly related to CVD risk in this sample, higher activity levels were associated with a healthier diet and lower ST indicating an overall healthier lifestyle of this subgroup. PMID:23224418

  2. Traditional CVD risk factors and socio-economic deprivation in Roma minority population of Croatia.

    PubMed

    Zeljko, Hrvojka; Skarić-Jurić, Tatjana; Narancic, Nina Smolej; Salihović, Marijana Pericić; Klarić, Irena Martinović; Barbalić, Maja; Starcević, Boris; Lauc, Lovorka Barać; Janićijević, Branka

    2008-09-01

    Researches into health inequalities consistently show disadvantages in health status, morbidity and mortality for various ethnic minority groups. Current knowledge about prevention of cardiovascular diseases (CVD) mainly derives from studies carried out in populations of European origin while the evidences involving Roma population are scarce. Roma, an ethnic minority of northern Indian origin, live in many countries throughout the world and are well known for preserved traditions and resistance to assimilation. They are most often marginalized economically, spatially, politically and in terms of culture. In order to assess the health status and health-related lifestyle attributes, a multidisciplinary anthropological and epidemiological community-based study was carried out including a total of 423 members of the Bayash Roma minority population living in two regions of Croatia (144 men and 279 women, aged 18-84 yrs). Hypertension (HT) was found in 24.8% Bayash Roma (21.5% men and 26.5% women) using standard diagnostic criteria (i.e. BP > or = 140/90 mm Hg or taking antihypertensive therapy). The prevalence increases from 5.9% in the age group 18-34 yrs; 35.0% in the age group 35-64 yrs, and 51.4% in the age group 65+ yrs. The prevalence of hypertension in the Bayash Roma is almost half of the magnitude of what is usually reported for the general population of Croatia. It is also lower when compared with other European populations and this finding is not due to comparatively younger average age of the Bayash sample. The significant association of hypertension with age and BMI was confirmed in this study and the importance of non-traditional SES-related CVD risk factors was highlighted. Smoking is a part of traditional Roma life-style and with 70% of smokers almost the entire population is equally exposed to this risk factor in their family environment. Since homogenously distributed, this risk factor did not show to be a significant predictor of hypertension. The

  3. Assessing absolute changes in breast cancer risk due to modifiable risk factors.

    PubMed

    Quante, Anne S; Herz, Julia; Whittemore, Alice S; Fischer, Christine; Strauch, Konstantin; Terry, Mary Beth

    2015-07-01

    Clinical risk assessment involves absolute risk measures, but information on modifying risk and preventing cancer is often communicated in relative terms. To illustrate the potential impact of risk factor modification in model-based risk assessment, we evaluated the performance of the IBIS Breast Cancer Risk Evaluation Tool, with and without current body mass index (BMI), for predicting future breast cancer occurrence in a prospective cohort of 665 postmenopausal women. Overall, IBIS's accuracy (overall agreement between observed and assigned risks) and discrimination (AUC concordance between assigned risks and outcomes) were similar with and without the BMI information. However, in women with BMI > 25 kg/m(2), adding BMI information improved discrimination (AUC = 63.9 % and 61.4 % with and without BMI, P < 0.001). The model-assigned 10-year risk difference for a woman with high (27 kg/m(2)) versus low (21 kg/m(2)) BMI was only 0.3 % for a woman with neither affected first-degree relatives nor BRCA1 mutation, compared to 4.5 % for a mutation carrier with three such relatives. This contrast illustrates the value of using information on modifiable risk factors in risk assessment and in sharing information with patients of their absolute risks with and without modifiable risk factors. PMID:26012643

  4. Flavonoid intake and the risk of ischaemic stroke and CVD mortality in middle-aged Finnish men: the Kuopio Ischaemic Heart Disease Risk Factor Study.

    PubMed

    Mursu, Jaakko; Voutilainen, Sari; Nurmi, Tarja; Tuomainen, Tomi-Pekka; Kurl, Sudhir; Salonen, Jukka T

    2008-10-01

    The role of flavonoids in CVD, especially in strokes, is unclear. Our aim was to study the role of flavonoids in CVD. We studied the association between the intakes of five subclasses (flavonols, flavones, flavanones, flavan-3-ols and anthocyanidins), a total of twenty-six flavonoids, on the risk of ischaemic stroke and CVD mortality. The study population consisted of 1950 eastern Finnish men aged 42-60 years free of prior CHD or stroke as part of the prospective population-based Kuopio Ischaemic Heart Disease Risk Factor Study. During an average follow-up time of 15.2 years, 102 ischaemic strokes and 153 CVD deaths occurred. In the Cox proportional hazards model adjusted for age and examination years, BMI,systolic blood pressure, hypertension medication, serum HDL- and LDL-cholesterol, serum TAG, maximal oxygen uptake, smoking, family history of CVD, diabetes, alcohol intake, energy-adjusted intake of folate, vitamin E, total fat and saturated fat intake (percentage of energy), men in the highest quartile of flavonol and flavan-3-ol intakes had a relative risk of 0.55 (95% CI 0.31, 0.99) and 0.59 (95% CI 0.30, 1.14) for ischaemic stroke, respectively, as compared with the lowest quartile. After multivariate adjustment, the relative risk for CVD death in the highest quartile of flavanone and flavone intakes were 0.54 (95% CI 0.32, 0.92) and 0.65 (95% CI 0.40, 1.05), respectively. The present results suggest that high intakes of flavonoids may be associated with decreased risk of ischaemic stroke and possibly with reduced CVD mortality. PMID:18377681

  5. Associations of Pregnancy Complications with Calculated CVD Risk and Cardiovascular Risk Factors in Middle Age: The Avon Longitudinal Study of Parents and Children

    PubMed Central

    Fraser, Abigail; Nelson, Scott M.; Macdonald-Wallis, Corrie; Cherry, Lynne; Butler, Elaine; Sattar, Naveed; Lawlor, Debbie A.

    2012-01-01

    Background The nature and contribution of different pregnancy related complications to future cardiovascular disease (CVD) and its risk factors, as well as mechanisms underlying these associations remain unclear. Methods and Results We studied associations of pregnancy diabetes, hypertensive disorders of pregnancy (HDP), preterm delivery and size for gestational age with calculated 10 year CVD risk (based on the Framingham score) and a wide range of cardiovascular risk factors measured 18 years after pregnancy (mean age at outcome assessment: 48 years) in a prospective cohort of 3,416 women. Gestational diabetes (GDM) was positively associated with fasting glucose and insulin, even after adjusting for potential confounders whilst HDP were associated with BMI, waist circumference, blood pressure, lipids and insulin. Large for gestational age (LGA) was associated with greater waist circumference and glucose concentrations, whilst small for gestational age (SGA) and preterm delivery were associated with higher blood pressure. The association with the calculated 10 year CVD risk based on the Framingham prediction score was OR=1.31 (95%CI: 1.11, 1.53) for preeclampsia and 1.26 (0.95, 1.68) for GDM compared to women without preeclampsia and GDM respectively. Conclusions HDP and pregnancy diabetes are independently associated with an increased calculated 10 year CVD risk. Preeclampsia may be the better predictor of future CVD since it was associated with a wider range of cardiovascular risk factors. Our results suggest that pregnancy may be an important opportunity for early identification of women at increased risk of CVD later in life. PMID:22344039

  6. Effect of RAAS blockers on adverse clinical outcomes in high CVD risk subjects with atrial fibrillation

    PubMed Central

    Chaugai, Sandip; Sherpa, Lhamo Yanchang; Sepehry, Amir A.; Arima, Hisatomi; Wang, Dao Wen

    2016-01-01

    Abstract Recent studies have demonstrated that atrial fibrillation significantly increases the risk of adverse clinical outcomes in high cardiovascular disease risk subjects. Application of renin–angiotensin–aldosterone system blockers for prevention of recurrence of atrial fibrillation and adverse clinical outcomes in subjects with atrial fibrillation is a theoretically appealing concept. However, results of clinical trials evaluating the effect of renin–angiotensin–aldosterone blockers on adverse clinical outcomes in high cardiovascular disease risk subjects with atrial fibrillation remain inconclusive. A pooled study of 6 randomized controlled trials assessing the efficacy of renin–angiotensin–aldosterone blockers on subjects with atrial fibrillation was performed. A total of 6 randomized controlled trials enrolled a total of 53,510 patients followed for 1 to 5 years. RAAS blockade therapy was associated with 14% reduction in the incidence of heart failure (OR: 0.86, [95%CI: 0.76– 0.97], P=0.018) and 17% reduction in the incidence of CVE (OR: 0.83, [95%CI: 0.70–0.99], P = 0.038). The corresponding decline in absolute risk against heart failure (ARR: 1.4%, [95%CI: 0.2–2.6%], P = 0.018) and CVE (ARR: 3.5%, [95%CI: 0.0–6.9%], P = 0.045) in the AF group was much higher than the non-AF group for heart failure (ARR: 0.4%, [95%CI: 0.0–0.7%], P = 0.057) and CVE (ARR: 1.6%, [95%CI: –0.1% to 3.3%], P = 0.071). No significant effect was noted on all-cause or cardiovascular mortality, stroke, or myocardial infarction. This study suggests that RAAS blockade offers protection against heart failure and cardiovascular events in high cardiovascular disease risk subjects with atrial fibrillation. PMID:27368043

  7. Community Cardiovascular Disease Risk From Cross-Sectional General Practice Clinical Data: A Spatial Analysis

    PubMed Central

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

    2015-01-01

    Introduction 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. Methods 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. Results 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. Conclusion 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. PMID:25719216

  8. Associations between flavan-3-ol intake and CVD risk in the Norfolk cohort of the European Prospective Investigation into Cancer (EPIC-Norfolk).

    PubMed

    Vogiatzoglou, Anna; Mulligan, Angela A; Bhaniani, Amit; Lentjes, Marleen A H; McTaggart, Alison; Luben, Robert N; Heiss, Christian; Kelm, Malte; Merx, Marc W; Spencer, Jeremy P E; Schroeter, Hagen; Khaw, Kay-Tee; Kuhnle, Gunter G C

    2015-07-01

    Dietary intervention studies suggest that flavan-3-ol intake can improve vascular function and reduce the risk of cardiovascular diseases (CVD). However, results from prospective studies failed to show a consistent beneficial effect. Associations between flavan-3-ol intake and CVD risk in the Norfolk arm of the European Prospective Investigation into Cancer and Nutrition (EPIC-Norfolk) were investigated. Data were available from 24,885 (11,252 men; 13,633 women) participants, recruited between 1993 and 1997 into the EPIC-Norfolk study. Flavan-3-ol intake was assessed using 7-day food diaries and the FLAVIOLA Flavanol Food Composition database. Missing data for plasma cholesterol and vitamin C were imputed using multiple imputation. Associations between flavan-3-ol intake and blood pressure at baseline were determined using linear regression models. Associations with CVD risk were estimated using Cox regression analyses. Median intake of total flavan-3-ols was 1034mg/d (range: 0-8531mg/d) for men and 970mg/d (0-6695mg/d) for women, median intake of flavan-3-ol monomers was 233mg/d (0-3248mg/d) for men and 217 (0-2712mg/d) for women. There were no consistent associations between flavan-3-ol monomer intake and baseline systolic and diastolic blood pressure (BP). After 286,147 person-years of follow-up, there were 8463 cardiovascular events and 1987 CVD related deaths; no consistent association between flavan-3-ol intake and CVD risk (HR 0.93, 95% CI: 0.87; 1.00; Q1 vs Q5) or mortality was observed (HR 0.93, 95% CI: 0.84; 1.04). Flavan-3-ol intake in EPIC-Norfolk is not sufficient to achieve a statistically significant reduction in CVD risk. PMID:25795512

  9. Associations between flavan-3-ol intake and CVD risk in the Norfolk cohort of the European Prospective Investigation into Cancer (EPIC-Norfolk)

    PubMed Central

    Vogiatzoglou, Anna; Mulligan, Angela A.; Bhaniani, Amit; Lentjes, Marleen A.H.; McTaggart, Alison; Luben, Robert N.; Heiss, Christian; Kelm, Malte; Merx, Marc W.; Spencer, Jeremy P.E.; Schroeter, Hagen; Khaw, Kay-Tee; Kuhnle, Gunter G.C.

    2015-01-01

    Dietary intervention studies suggest that flavan-3-ol intake can improve vascular function and reduce the risk of cardiovascular diseases (CVD). However, results from prospective studies failed to show a consistent beneficial effect. Associations between flavan-3-ol intake and CVD risk in the Norfolk arm of the European Prospective Investigation into Cancer and Nutrition (EPIC-Norfolk) were investigated. Data were available from 24,885 (11,252 men; 13,633 women) participants, recruited between 1993 and 1997 into the EPIC-Norfolk study. Flavan-3-ol intake was assessed using 7-day food diaries and the FLAVIOLA Flavanol Food Composition database. Missing data for plasma cholesterol and vitamin C were imputed using multiple imputation. Associations between flavan-3-ol intake and blood pressure at baseline were determined using linear regression models. Associations with CVD risk were estimated using Cox regression analyses. Median intake of total flavan-3-ols was 1034 mg/d (range: 0–8531 mg/d) for men and 970 mg/d (0–6695 mg/d) for women, median intake of flavan-3-ol monomers was 233 mg/d (0–3248 mg/d) for men and 217 (0–2712 mg/d) for women. There were no consistent associations between flavan-3-ol monomer intake and baseline systolic and diastolic blood pressure (BP). After 286,147 person-years of follow-up, there were 8463 cardiovascular events and 1987 CVD related deaths; no consistent association between flavan-3-ol intake and CVD risk (HR 0.93, 95% CI: 0.87; 1.00; Q1 vs Q5) or mortality was observed (HR 0.93, 95% CI: 0.84; 1.04). Flavan-3-ol intake in EPIC-Norfolk is not sufficient to achieve a statistically significant reduction in CVD risk. PMID:25795512

  10. In cross-sectional observations, dietary quality is not associated with CVD risk in women; in men the positive association is accounted for by BMI

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The role that BMI plays in the association between dietary quality and CVD risk is not known. We aimed to better understand this relationship using statistical methods which correct for sex-specific underreporting of dietary intake. Overall, dietary quality was assessed using the Healthy Eating Inde...

  11. A community assessment to inform a multi-level intervention to reduce CVD risk and risk disparities in a rural community

    PubMed Central

    Vu, Maihan B.; Garcia, Beverly A.; McGuirt, Jared T.; Braxton, Danielle; Hengel, Constance E.; Huff, Joey V.; Keyserling, Thomas C.; Ammerman, Alice S.

    2014-01-01

    In order to complete a formative evaluation to identify community-level assets and barriers to healthy lifestyle choices, we conducted qualitative interviews, community audits, and secondary data analyses. We solicited local leaders’ perspectives regarding ‘win-ability’ of obesity prevention policy options. Participants noted that many resources were available, yet a barrier was high cost. There were more parks per capita in low-income areas, but they were of lower quality. The most winnable obesity prevention policy was incentives for use of food from local farms. Results are being used to inform an intervention to reduce CVD risk in a rural eastern North Carolina. PMID:23455684

  12. Absolute and Comparative Cancer Risk Perceptions Among Smokers in Two Cities in China

    PubMed Central

    2014-01-01

    Introduction: Knowledge about health effects of smoking motivates quit attempts and sustained abstinence among smokers and also predicts greater acceptance of tobacco control efforts such as cigarette taxes and public smoking bans. We examined whether smokers in China, the world’s largest consumer of cigarettes, recognized their heightened personal risk of cancer relative to nonsmokers. Methods: A sample of Chinese people (N = 2,517; 555 current smokers) from 2 cities (Beijing and Hefei) estimated their personal risk of developing cancer, both in absolute terms (overall likelihood) and in comparative terms (relative to similarly aged people). Results: Controlling for demographics, smokers judged themselves to be at significantly lower risk of cancer than did nonsmokers on the comparative measure. No significant difference emerged between smokers and nonsmokers in absolute estimates. Conclusions: Smokers in China did not recognize their heightened personal risk of cancer, possibly reflecting ineffective warning labels on cigarette packs, a positive affective climate associated with smoking in China, and beliefs that downplay personal vulnerability among smokers (e.g., I don’t smoke enough to increase my cancer risk; I smoke high-quality cigarettes that won’t cause cancer). PMID:24668289

  13. The Association between a Vegetarian Diet and Cardiovascular Disease (CVD) Risk Factors in India: The Indian Migration Study

    PubMed Central

    Shridhar, Krithiga; Dhillon, Preet Kaur; Bowen, Liza; Kinra, Sanjay; Bharathi, Ankalmadugu Venkatsubbareddy; Prabhakaran, Dorairaj; Reddy, Kolli Srinath; Ebrahim, Shah

    2014-01-01

    Background Studies in the West have shown lower cardiovascular disease (CVD) risk among people taking a vegetarian diet, but these findings may be confounded and only a minority selects these diets. We evaluated the association between vegetarian diets (chosen by 35%) and CVD risk factors across four regions of India. Methods Study participants included urban migrants, their rural siblings and urban residents, of the Indian Migration Study from Lucknow, Nagpur, Hyderabad and Bangalore (n = 6555, mean age-40.9 yrs). Information on diet (validated interviewer-administered semi-quantitative food frequency questionnaire), tobacco, alcohol, physical history, medical history, as well as blood pressure, fasting blood and anthropometric measurements were collected. Vegetarians ate no eggs, fish, poultry or meat. Using robust standard error multivariate linear regression models, we investigated the association of vegetarian diets with blood cholesterol, low density lipoprotein (LDL), high density lipoprotein (HDL), triglycerides, fasting blood glucose (FBG), systolic (SBP) and diastolic blood pressure (DBP). Results Vegetarians (32.8% of the study population) did not differ from non-vegetarians with respect to age, use of smokeless tobacco, body mass index, and prevalence of diabetes or hypertension. Vegetarians had a higher standard of living and were less likely to smoke, drink alcohol (p<0.0001) and were less physically active (p = 0.04). In multivariate analysis, vegetarians had lower levels of total cholesterol (β = −0.1 mmol/L (95% CI: −0.03 to −0.2), p = 0.006), triglycerides (β = −0.05 mmol/L (95% CI: −0.007 to −0.01), p = 0.02), LDL (β = −0.06 mmol/L (95% CI: −0.005 to −0.1), p = 0.03) and lower DBP (β = −0.7 mmHg (95% CI: −1.2 to −0.07), p = 0.02). Vegetarians also had decreases in SBP (β = −0.9 mmHg (95% CI: −1.9 to 0.08), p = 0.07) and FBG level (β = −0.07 mmol/L (95% CI:

  14. Examining associations between dietary patterns and metabolic CVD risk factors: a novel use of structural equation modelling.

    PubMed

    Castro, Michelle Alessandra; Baltar, Valéria Troncoso; Marchioni, Dirce Maria; Fisberg, Regina Mara

    2016-05-01

    The association between dietary patterns and metabolic cardiovascular risk factors has long been addressed but there is a lack of evidence towards the effects of the overall diet on the complex net of biological inter-relationships between risk factors. This study aimed to derive dietary patterns and examine their associations with metabolic cardiovascular risk factors following a theoretic model for the relationship between them. Participants included 417 adults of both sexes, enrolled to the cross-sectional population-based study performed in Brazil. Body weight, waist circumference, high-sensitivity C-reactive protein, blood pressure, total cholesterol:HDL-cholesterol ratio, TAG:HDL-cholesterol ratio, fasting plasma glucose and serum leptin were evaluated. Food consumption was assessed by two non-consecutive 24-h dietary recalls adjusted for the within-person variation of intake. A total of three dietary patterns were derived by exploratory structural equation modelling: 'Traditional', 'Prudent' and 'Modern'. The 'Traditional' pattern had a negative and direct effect on obesity indicators (serum LEP, body weight and waist circumference) and negative indirect effects on total cholesterol:HDL-cholesterol ratio, TAG:HDL-cholesterol ratio and fasting plasma glucose. The 'Prudent' pattern had a negative and direct effect on systolic blood pressure. No association was observed for the 'Modern' pattern and metabolic risk factors. In conclusion, the 'Traditional' and 'Prudent' dietary patterns were negatively associated with metabolic cardiovascular risk factors among Brazilian adults. Their apparent protective effects against obesity and high blood pressure may be important non-pharmacological strategies for the prevention and control of obesity-related metabolic disorders and CVD. PMID:26931638

  15. Prevalence of obesity and hypertension among University students’ and their knowledge and attitude towards risk factors of Cardiovascular Disease (CVD) in Jeddah, Saudi Arabia

    PubMed Central

    Baig, Mukhtiar; Gazzaz, Zohair J; Gari, Mamdooh A; Al-Attallah, Haidar G; Al-Jedaani, Khaled S; Mesawa, Amjad TA; Al-Hazmi, Abdulrahman A

    2015-01-01

    Objectives: To investigate the prevalence of obesity and hypertension among University students’ and their knowledge and attitude towards risk factors of cardiovascular disease (CVD) in Jeddah,: Saudi Arabia. Methods: A total of 610 male students were selected for present cross sectional study and their blood pressure (BP) and body mass index (BMI) was determined, other data was gathered through a questionnaire, and SPSS-16 was used for analyzing data. Results: Out of 610 students, 7.5% were hypertensive (systolic 2.6% and diastolic 6.3%) while the BMI of 51.6% was in the normal range, 29.8% were overweight and 10.7% were moderately obese and 7.9% were severely obese. Majority of the participants considered that smoking, increased fatty food intake, obesity, high BP, and increased LDL-cholesterol level, are the main causes of the CVD. Most of the participants agreed that one should know his BP, blood sugar, serum cholesterol and one should maintain normal body weight and should do regular exercise. They were also aware that healthy lifestyle could prevent CVD. However, majority of the participants were not practicing healthy lifestyle. Conclusion: A huge gap exists in the knowledge, attitude and practice regarding risk factors of CVD among the university students. PMID:26430410

  16. Lipid-Lowering Drug Therapy for CVD Prevention: Looking into the Future.

    PubMed

    Stein, Evan A; Raal, Frederick J

    2015-11-01

    Over the past three decades, statins have become first-line treatment for reducing LDL cholesterol (LDL-C) and cardiovascular disease (CVD). They have provided a clear, robust, and reproducible relationship between the absolute LDL-C reduction and the decrease in CVD; every 1 mmol/L (~40 mg/dL) in LDL-C reduction results in a 22 % decrease in CVD events. This relationship has recently been extended to reduction in LDL-C with a non-statin, ezetimibe, on top of statin therapy, further consolidating LDL-C as the cornerstone in CVD risk reduction. Despite these two effective and safe LDL-C-lowering drugs, there remains a need for additional drugs to reduce LDL-C, the focus of this review which covers agents which produce sufficient LDL-C reduction to potentially help address this unmet need and are either recently approved or currently in clinical trials. PMID:26385394

  17. Whole-grain consumption and the risk of all-cause, CVD and cancer mortality: a meta-analysis of prospective cohort studies.

    PubMed

    Wei, Honglei; Gao, Zong; Liang, Rui; Li, Zengqiang; Hao, Hong; Liu, Xu

    2016-08-01

    Results of the relationships between dietary whole-grain consumption and the risk of all-cause, CVD and cancer-specific mortality are mixed. We summarised the evidence based on a meta-analysis of prospective cohort studies. Pertinent studies were identified by searching articles in the MEDLINE and EMBASE databases up to 20 January 2016 and by reviewing the reference lists of the retrieved articles. Random-effects models were used to calculate summary relative risks (SRR) and 95 % CI. In all, eleven prospective studies (ten publications) were included in the meta-analysis. There were a total of 816 599 subjects and 89 251 cases of all-cause mortality. On the basis of the highest v. the lowest categories of intake, whole grains may be associated with a lower risk of mortality from all causes (SRR 0·87; 95 % CI 0·84, 0·90), CVD (SRR 0·81; 95 % CI 0·75, 0·89) and all cancers (SRR 0·89; 95 % CI 0·82, 0·96). For each 3 servings/d increase in whole-grain intake, there was a 19 % reduction in the risk of all-cause mortality (SRR 0·81; 95 % CI 0·76, 0·85), a 26 % reduction in CVD mortality (SRR 0·74; 95 % CI 0·66, 0·83) and a 9 % reduction in cancer mortality (SRR 0·91; 95 % CI 0·84, 0·98). The current meta-analysis provides some evidence that high intake of whole grains was inversely associated with the risk of all-cause, CVD and cancer-specific mortality. Further well-designed studies, including clinical trials and in different populations, are required to confirm our findings. PMID:27215285

  18. Diabetes and CVD risk during angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker treatment in hypertension: a study of 15 990 patients

    PubMed Central

    Hasvold, L P; Bodegård, J; Thuresson, M; Stålhammar, J; Hammar, N; Sundström, J; Russell, D; Kjeldsen, S E

    2014-01-01

    Differences in clinical effectiveness between angiotensin-converting enzyme inhibitors (ACEis) and angiotensin receptor blockers (ARBs) in the primary treatment of hypertension are unknown. The aim of this retrospective cohort study was to assess the prevention of type 2 diabetes and cardiovascular disease (CVD) in patients treated with ARBs or ACEis. Patients initiated on enalapril or candesartan treatment in 71 Swedish primary care centers between 1999 and 2007 were included. Medical records data were extracted and linked with nationwide hospital discharge and cause of death registers. The 11 725 patients initiated on enalapril and 4265 on candesartan had similar baseline characteristics. During a mean follow-up of 1.84 years, 36 482 patient-years, the risk of new diabetes onset was lower in the candesartan group (hazard ratio (HR) 0.81, 95% confidence interval (CI) 0.69–0.96, P=0.01) compared with the enalapril group. No difference between the groups was observed in CVD risk (HR 0.99, 95% CI 0.87–1.13, P=0.86). More patients discontinued treatment in the enalapril group (38.1%) vs the candesartan group (27.2%). In a clinical setting, patients initiated on candesartan treatment had a lower risk of new-onset type 2 diabetes and lower rates of drug discontinuation compared with patients initiated on enalapril. No differences in CVD risk were observed. PMID:25211055

  19. Behavioral Counseling to Promote a Healthful Diet and Physical Activity for CVD Prevention in Adults with Risk Factors

    MedlinePlus

    ... Task Force learned about the potential benefits and harms of behavioral counseling to prevent CVD in overweight ... the end of this document). Potential Benefits and Harms of Behavioral Counseling to Prevent Cardiovascular Disease The ...

  20. Realized volatility and absolute return volatility: a comparison indicating market risk.

    PubMed

    Zheng, Zeyu; Qiao, Zhi; Takaishi, Tetsuya; Stanley, H Eugene; Li, Baowen

    2014-01-01

    Measuring volatility in financial markets is a primary challenge in the theory and practice of risk management and is essential when developing investment strategies. Although the vast literature on the topic describes many different models, two nonparametric measurements have emerged and received wide use over the past decade: realized volatility and absolute return volatility. The former is strongly favored in the financial sector and the latter by econophysicists. We examine the memory and clustering features of these two methods and find that both enable strong predictions. We compare the two in detail and find that although realized volatility has a better short-term effect that allows predictions of near-future market behavior, absolute return volatility is easier to calculate and, as a risk indicator, has approximately the same sensitivity as realized volatility. Our detailed empirical analysis yields valuable guidelines for both researchers and market participants because it provides a significantly clearer comparison of the strengths and weaknesses of the two methods. PMID:25054439

  1. The Ethics of Information: Absolute Risk Reduction and Patient Understanding of Screening

    PubMed Central

    Meslin, Eric M.

    2008-01-01

    Some experts have argued that patients should routinely be told the specific magnitude and absolute probability of potential risks and benefits of screening tests. This position is motivated by the idea that framing risk information in ways that are less precise violates the ethical principle of respect for autonomy and its application in informed consent or shared decision-making. In this Perspective, we consider a number of problems with this view that have not been adequately addressed. The most important challenges stem from the danger that patients will misunderstand the information or have irrational responses to it. Any initiative in this area should take such factors into account and should consider carefully how to apply the ethical principles of respect for autonomy and beneficence. PMID:18421509

  2. Cereal fibre intake and risk of mortality from all causes, CVD, cancer and inflammatory diseases: a systematic review and meta-analysis of prospective cohort studies.

    PubMed

    Hajishafiee, Maryam; Saneei, Parvane; Benisi-Kohansal, Sanaz; Esmaillzadeh, Ahmad

    2016-07-01

    Dietary fibre intake has been associated with a lower risk of mortality; however, findings on the association of different sources of dietary fibre with mortality are conflicting. We performed a systematic review and meta-analysis of the prospective cohort studies to assess the relation between cereal fibre intake and cause-specific mortality. Medline/PubMed, SCOPUS, EMBASE, ISI web of Science and Google scholar were searched up to April 2015. Eligible prospective cohort studies were included if they provided hazard ratios (HR) or relative risks (RR) and corresponding 95 % CI for the association of cereal fibre intake and mortality from all causes, CVD, cancer and inflammatory diseases. The study-specific HR were pooled by using the random-effects model. In total, fourteen prospective studies that examined the association of cereal fibre intake with mortality from all causes (n 48 052 death), CVD (n 16 882 death), cancer (n 19 489 death) and inflammatory diseases (n 1092 death) were included. The pooled adjusted HR of all-cause mortality for the highest v. the lowest category of cereal fibre intake was 0·81 (95 % CI 0·79, 0·83). Consumption of cereal fibre intake was associated with an 18 % lower risk of CVD mortality (RR 0·82; 95 % CI 0·78, 0·86). Moreover, an inverse significant association was observed between cereal fibre intake and risk of death from cancer (RR 0·85; 95 % CI 0·81, 0·89). However, no significant association was seen between cereal fibre intake and inflammation-related mortality. This meta-analysis provides further evidence that cereal fibre intake was protectively associated with mortality from all causes, CVD and cancer. PMID:27193606

  3. Next generation of weight management medications: implications for diabetes and CVD risk.

    PubMed

    Wharton, S; Serodio, K J

    2015-05-01

    Since the 1980s, the prevalence of obesity has almost doubled worldwide. Treatments for obesity include lifestyle modification, medications and surgery. Newer anti-obesity medications have been shown to be effective at inducing initial weight management in addition to successful long-term weight maintenance. Historically, weight management medications have been associated with public safety concerns that have resulted in the majority being withdrawn from the market or never receiving medicinal authorization. Recently, several countries have approved some newer generation weight management medications which may be beneficial to combat obesity. These medications have varying effects on cardiometabolic parameters, both positive and potentially negative. This review will outline the mechanisms of action of these medications and their implications for both diabetes and cardiovascular risks. PMID:25894803

  4. External Validation of the Garvan Nomograms for Predicting Absolute Fracture Risk: The Tromsø Study

    PubMed Central

    Ahmed, Luai A.; Nguyen, Nguyen D.; Bjørnerem, Åshild; Joakimsen, Ragnar M.; Jørgensen, Lone; Størmer, Jan; Bliuc, Dana; Center, Jacqueline R.; Eisman, John A.; Nguyen, Tuan V.; Emaus, Nina

    2014-01-01

    Background Absolute risk estimation is a preferred approach for assessing fracture risk and treatment decision making. This study aimed to evaluate and validate the predictive performance of the Garvan Fracture Risk Calculator in a Norwegian cohort. Methods The analysis included 1637 women and 1355 aged 60+ years from the Tromsø study. All incident fragility fractures between 2001 and 2009 were registered. The predicted probabilities of non-vertebral osteoporotic and hip fractures were determined using models with and without BMD. The discrimination and calibration of the models were assessed. Reclassification analysis was used to compare the models performance. Results The incidence of osteoporotic and hip fracture was 31.5 and 8.6 per 1000 population in women, respectively; in men the corresponding incidence was 12.2 and 5.1. The predicted 5-year and 10-year probability of fractures was consistently higher in the fracture group than the non-fracture group for all models. The 10-year predicted probabilities of hip fracture in those with fracture was 2.8 (women) to 3.1 times (men) higher than those without fracture. There was a close agreement between predicted and observed risk in both sexes and up to the fifth quintile. Among those in the highest quintile of risk, the models over-estimated the risk of fracture. Models with BMD performed better than models with body weight in correct classification of risk in individuals with and without fracture. The overall net decrease in reclassification of the model with weight compared to the model with BMD was 10.6% (p = 0.008) in women and 17.2% (p = 0.001) in men for osteoporotic fractures, and 13.3% (p = 0.07) in women and 17.5% (p = 0.09) in men for hip fracture. Conclusions The Garvan Fracture Risk Calculator is valid and clinically useful in identifying individuals at high risk of fracture. The models with BMD performed better than those with body weight in fracture risk prediction. PMID:25255221

  5. The Influence of Absolute and Comparative Risk Perceptions on Cervical Cancer Screening and the Mediating Role of Cancer Worry.

    PubMed

    Zhao, Xinyan; Nan, Xiaoli

    2016-01-01

    This research investigates the interrelationships between cancer risk perceptions (absolute and comparative risk perceptions), cancer worry, and cervical cancer screening. Using a nationally representative survey data set (N = 2,304) from the 2012 Health Information National Trends Survey Circle 1, we found that although neither absolute risk perceptions nor comparative risk perceptions exerted a direct impact on women's compliance with the cervical cancer screening recommendation (i.e., that women ages 21 to 65 obtain Pap smear every 3 years; U.S. Preventive Services Task Force, 2012 ), both types of risk perceptions had an indirect effect on cervical cancer screening through the mediation of cancer worry. These results suggest a primal role of affect in health decision making. Implications of the findings for cancer risk communication are discussed. PMID:26312444

  6. A model for predicting individuals' absolute risk of esophageal adenocarcinoma: Moving toward tailored screening and prevention.

    PubMed

    Xie, Shao-Hua; Lagergren, Jesper

    2016-06-15

    Esophageal adenocarcinoma (EAC) is characterized by rapidly increasing incidence and poor prognosis, stressing the need for preventive and early detection strategies. We used data from a nationwide population-based case-control study, which included 189 incident cases of EAC and 820 age- and sex-matched control participants, from 1995 through 1997 in Sweden. We developed risk prediction models based on unconditional logistic regression. Candidate predictors included established and readily identifiable risk factors for EAC. The performance of model was assessed by the area under receiver operating characteristic curve (AUC) with cross-validation. The final model could explain 94% of all case patients with EAC (94% population attributable risk) and included terms for gastro-esophageal reflux symptoms or use of antireflux medication, body mass index (BMI), tobacco smoking, duration of living with a partner, previous diagnoses of esophagitis and diaphragmatic hernia and previous surgery for esophagitis, diaphragmatic hernia or severe reflux or gastric or duodenal ulcer. The AUC was 0.84 (95% confidence interval [CI] 0.81-0.87) and slightly lower after cross-validation. A simpler model, based only on reflux symptoms or use of antireflux medication, BMI and tobacco smoking could explain 91% of the case patients with EAC and had an AUC of 0.82 (95% CI 0.78-0.85). These EAC prediction models showed good discriminative accuracy, but need to be validated in other populations. These models have the potential for future use in identifying individuals with high absolute risk of EAC in the population, who may be considered for endoscopic screening and targeted prevention. PMID:26756848

  7. The Contribution of Stress to the Social Patterning of Clinical and Subclinical CVD Risk Factors in African Americans: The Jackson Heart Study

    PubMed Central

    Gebreab, Samson Y.; Diez-Roux, Ana V.; Hickson, DeMarc A.; Boykin, Shawn; Sims, Mario; Sarpong, Daniel F.; Taylor, Herman A.; Wyatt, Sharon B.

    2012-01-01

    It is often hypothesized that psychosocial stress may contribute to associations of socioeconomic position (SEP) with risk factors for cardiovascular disease (CVD). However, few studies have investigated this hypothesis among African Americans, who may be more frequently exposed to stressors due to social and economic circumstances. Cross-sectional data from the Jackson Heart Study (JHS), a large population-based cohort of African Americans, were used to examine the contributions of stressors to the association of SEP with selected cardiovascular (CVD) risk factors and subclinical atherosclerotic disease. Among women, higher income was associated with lower prevalence of hypertension, obesity, diabetes and carotid plaque and lower levels of stress. Higher stress levels were also weakly, albeit positively, associated with hypertension, diabetes, and obesity, but not with plaque. Adjustment for the stress measures reduced the associations of income with hypertension, diabetes and obesity by a small amount that was comparable to, or larger, than the reduction observed after adjustment for behavioral risk factors. In men, high income was associated with lower prevalence of diabetes and stressors were not consistently associated with any of the outcomes examined. Overall, modest mediation effects of stressors were observed for diabetes (15.9%), hypertension (9.7%), and obesity (5.1%) among women but only results for diabetes were statistically significant. No mediation effects of stressors were observed in men. Our results suggest that stressors may partially contribute to associations of SEP with diabetes and possibly hypertension and obesity in African American women. Further research with appropriate study designs and data is needed to understand the dynamic and interacting effects of stressors and behaviors on CVD outcomes as well as sex differences in these effects. PMID:22841454

  8. Treatment with DPP-4I Anagliptin or α-GI Miglitol Reduces IGT Development and the Expression of CVD Risk Factors in OLETF Rats.

    PubMed

    Imai, Chihiro; Harazaki, Tomomi; Inoue, Seiya; Mochizuki, Kazuki; Goda, Toshinao

    2015-01-01

    It has been reported that postprandial hyperglycemia from the pre-diabetic stage, especially from the impaired glucose tolerance (IGT) stage, is positively associated with subsequent incidences of cardiovascular diseases (CVD) and type 2 diabetes. In this study, we aimed to investigate whether treatment with a dipeptidyl peptidase-4 inhibitor (DPP-4I) or an α-glucosidase inhibitor (α-GI), either of which suppresses postprandial hyperglycemia, reduces the expression of CVD risk factors in an IGT animal model. A DPP-4I, anagliptin (1,200 ppm), or an α-GI, miglitol (600 ppm), in the diet was administered for 47 wk to Otsuka Long-Evans Tokushima Fatty (OLETF) rats, a model for spontaneously-developed type 2 diabetes, at the IGT stage. We examined whether each treatment reduced the expression of CVD risk factors such as inflammatory cytokines/cytokine-like factors in peripheral leukocytes and adhesion molecules in the aortic tissues and circulation. Treatment with either drug reduced IGT development and repressed expression of the interleukin-1β, tumor necrosis factor-α, S100a9, and S100a11 genes in peripheral leukocytes in the fasting state at weeks 25 and 39. The mRNA levels of E-selectin in aortic tissues and protein levels of the soluble forms of E-selectin and ICAM-1 in arterial blood were significantly lower in the anagliptin and miglitol groups than in the control group. Our results suggest that long-term treatment with anagliptin or miglitol in OLETF rats at the IGT stage suppresses the expression of inflammatory cytokines in peripheral leukocytes and adhesion molecules in aortic tissues. PMID:26440638

  9. Decision-making using absolute cardiovascular risk reduction and incremental cost-effectiveness ratios: a case study

    PubMed Central

    Ker, J A; Oosthuizen, H; Rheeder, P

    2008-01-01

    Summary Background Many clinical guidelines have adopted a multifactorial cardiovascular risk assessment to identify high-risk individuals for treatment. The Framingham risk chart is a widely used risk engine to calculate the absolute cardiovascular risk of an individual. Cost-effective analyses are typically used to evaluate therapeutic strategies, but it is more problematic for a clinician when faced with alternative therapeutic strategies to calculate cost effectiveness. Aim We used a single simulated-patient model to explore the effect of different drug treatments on the calculated absolute cardiovascular risk. Methods The Framingham risk score was calculated on a hypothetical patient, and drug treatment was initiated. After every drug introduced, the score was recalculated. Single-exit pricing of the various drugs in South Africa was used to calculate the cost of reducing predicted cardiovascular risk. Results The cost-effective ratio of an antihypertensive treatment strategy was calculated to be R21.35 per percentage of risk reduction. That of a statin treatment strategy was R22.93 per percentage of risk reduction. Using a high-dose statin, the cost-effective ratio was R12.81 per percentage of risk reduction. Combining the antihypertensive and statin strategy demonstrated a cost-effective ratio of R23.84 per percentage of risk reduction. A combination of several drugs enabled the hypothetical patient to reduce the risk to 14% at a cost-effective ratio of R17.18 per percentage of risk reduction. Conclusion This model demonstrates a method to compare different therapeutic strategies to reduce cardiovascular risk with their cost-effective ratios. PMID:18516355

  10. Easy Absolute Values? Absolutely

    ERIC Educational Resources Information Center

    Taylor, Sharon E.; Mittag, Kathleen Cage

    2015-01-01

    The authors teach a problem-solving course for preservice middle-grades education majors that includes concepts dealing with absolute-value computations, equations, and inequalities. Many of these students like mathematics and plan to teach it, so they are adept at symbolic manipulations. Getting them to think differently about a concept that they…

  11. Nuts and CVD.

    PubMed

    Ros, Emilio

    2015-04-01

    Nuts are nutrient-dense foods with complex matrices rich in unsaturated fatty acids and other bioactive compounds, such as l-arginine, fibre, healthful minerals, vitamin E, phytosterols and polyphenols. By virtue of their unique composition, nuts are likely to beneficially affect cardiovascular health. Epidemiological studies have associated nut consumption with a reduced incidence of CHD in both sexes and of diabetes in women, but not in men. Feeding trials have clearly demonstrated that consumption of all kinds of nuts has a cholesterol-lowering effect, even in the context of healthy diets. There is increasing evidence that nut consumption has a beneficial effect on oxidative stress, inflammation and vascular reactivity. Blood pressure, visceral adiposity and the metabolic syndrome also appear to be positively influenced by nut consumption. Contrary to expectations, epidemiological studies and clinical trials suggest that regular nut consumption is not associated with undue weight gain. Recently, the PREvención con DIeta MEDiterránea randomised clinical trial of long-term nutrition intervention in subjects at high cardiovascular risk provided first-class evidence that regular nut consumption is associated with a 50 % reduction in incident diabetes and, more importantly, a 30 % reduction in CVD. Of note, incident stroke was reduced by nearly 50 % in participants allocated to a Mediterranean diet enriched with a daily serving of mixed nuts (15 g walnuts, 7.5 g almonds and 7.5 g hazelnuts). Thus, it is clear that frequent nut consumption has a beneficial effect on CVD risk that is likely to be mediated by salutary effects on intermediate risk factors. PMID:26148914

  12. Reducing salt intake for prevention of cardiovascular diseases in high-risk patients by advanced health education intervention (RESIP-CVD study), Northern Thailand: study protocol for a cluster randomized trial

    PubMed Central

    2012-01-01

    Background Decreasing salt consumption can prevent cardiovascular diseases (CVD). Practically, it is difficult to promote people’s awareness of daily salt intake and to change their eating habits in terms of reducing salt intake for better cardiovascular health. Health education programs visualizing daily dietary salt content and intake may promote lifestyle changes in patients at high risk of cardiovascular diseases. Methods/Design This is a cluster randomized trial. A total of 800 high-CVD-risk patients attending diabetes and hypertension clinics at health centers in Muang District, Chiang Rai province, Thailand, will be studied with informed consent. A health center recruiting 100 participants is a cluster, the unit of randomization. Eight clusters will be randomized into intervention and control arms and followed up for 1 year. Within the intervention clusters the following will be undertaken: (1) salt content in the daily diet will be measured and shown to study participants; (2) 24-hour salt intake will be estimated in overnight-collected urine and the results shown to the participants; (3) a dietician will assist small group health education classes in cooking meals with less salt. The primary outcome is blood pressure change at the 1-year follow-up. Secondary outcomes at the 1-year follow-up are estimated 24-hoursalt intake, incidence of CVD events and CVD death. The intention-to-treat analysis will be followed. Blood pressure and estimated 24-hour salt intake will be compared between intervention and control groups at the cluster and individual level at the 1-year follow-up. Clinical CVD events and deaths will be analyzed by time-event analysis. Retinal blood vessel calibers of CVD-risk patients will be assessed cross-sectionally. Behavioral change to reduce salt intake and the influencing factors will be determined by structured equation model (SEM). Multilevel regression analyses will be applied. Finally, the cost effectiveness of the intervention

  13. Association between dietary fibre intake and fruit, vegetable or whole-grain consumption and the risk of CVD: results from the PREvención con DIeta MEDiterránea (PREDIMED) trial.

    PubMed

    Buil-Cosiales, Pilar; Toledo, Estefania; Salas-Salvadó, Jordi; Zazpe, Itziar; Farràs, Marta; Basterra-Gortari, Francisco Javier; Diez-Espino, Javier; Estruch, Ramon; Corella, Dolores; Ros, Emilio; Marti, Amelia; Gómez-Gracia, Enrique; Ortega-Calvo, Manuel; Arós, Fernando; Moñino, Manuel; Serra-Majem, Lluis; Pintó, Xavier; Lamuela-Raventós, Rosa Maria; Babio, Nancy; Gonzalez, Jose I; Fitó, Montserrat; Martínez-González, Miguel A

    2016-08-01

    Prospective studies assessing the association between fibre intake or fibre-rich food consumption and the risk of CVD have often been limited by baseline assessment of diet. Thus far, no study has used yearly repeated measurements of dietary changes during follow-up. Moreover, previous studies included healthy and selected participants who did not represent subjects at high cardiovascular risk. We used yearly repeated measurements of diet to investigate the association between fibre intake and CVD in a Mediterranean cohort of elderly adults at high cardiovascular risk. We followed-up 7216 men (55-80 years) and women (60-80 years) initially free of CVD for up to 7 years in the PREvención con DIeta MEDiterránea study (registered as ISRCTN35739639). A 137-item validated FFQ was repeated yearly to assess diet. The primary end point, confirmed by a blinded ad hoc Event Adjudication Committee, was a composite of cardiovascular death, myocardial infarction and stroke. Time-dependent Cox's regression models were used to estimate the risk of CVD according to baseline dietary exposures and to their yearly updated changes. We found a significant inverse association for fibre (P for trend=0·020) and fruits (P for trend=0·024) in age-sex adjusted models, but the statistical significance was lost in fully adjusted models. However, we found a significant inverse association with CVD incidence for the sum of fruit and vegetable consumption. Participants who consumed in total nine or more servings/d of fruits plus vegetables had a hazard ratio 0·60 (95 % CI 0·40, 0·96) of CVD in comparison with those consuming <5 servings/d. PMID:27264785

  14. Predicting Absolute Risk of Type 2 Diabetes Using Age and Waist Circumference Values in an Aboriginal Australian Community

    PubMed Central

    2015-01-01

    Objectives To predict in an Australian Aboriginal community, the 10-year absolute risk of type 2 diabetes associated with waist circumference and age on baseline examination. Method A sample of 803 diabetes-free adults (82.3% of the age-eligible population) from baseline data of participants collected from 1992 to 1998 were followed-up for up to 20 years till 2012. The Cox-proportional hazard model was used to estimate the effects of waist circumference and other risk factors, including age, smoking and alcohol consumption status, of males and females on prediction of type 2 diabetes, identified through subsequent hospitalisation data during the follow-up period. The Weibull regression model was used to calculate the absolute risk estimates of type 2 diabetes with waist circumference and age as predictors. Results Of 803 participants, 110 were recorded as having developed type 2 diabetes, in subsequent hospitalizations over a follow-up of 12633.4 person-years. Waist circumference was strongly associated with subsequent diagnosis of type 2 diabetes with P<0.0001 for both genders and remained statistically significant after adjusting for confounding factors. Hazard ratios of type 2 diabetes associated with 1 standard deviation increase in waist circumference were 1.7 (95%CI 1.3 to 2.2) for males and 2.1 (95%CI 1.7 to 2.6) for females. At 45 years of age with baseline waist circumference of 100 cm, a male had an absolute diabetic risk of 10.9%, while a female had a 14.3% risk of the disease. Conclusions The constructed model predicts the 10-year absolute diabetes risk in an Aboriginal Australian community. It is simple and easily understood and will help identify individuals at risk of diabetes in relation to waist circumference values. Our findings on the relationship between waist circumference and diabetes on gender will be useful for clinical consultation, public health education and establishing WC cut-off points for Aboriginal Australians. PMID:25876058

  15. Validation of Biomarkers of CVD Risk from Dried Blood Spots in Community-Based Research: Methodologies and Study-Specific Serum Equivalencies.

    PubMed

    Samuelsson, Laura B; Hall, Martica H; McLean, Shakir; Porter, James H; Berkman, Lisa; Marino, Miguel; Sembajwe, Grace; McDade, Thomas W; Buxton, Orfeu M

    2015-01-01

    Dried blood spot (DBS) methodology offers significant advantages over venipuncture in studies of vulnerable populations or large-scale studies, including reduced participant burden and higher response rates. Uncertainty about the validity of cardiovascular disease (CVD) risk biomarkers remains a barrier to wide-scale use. We determined the validity of DBS-derived biomarkers of CVD risk versus gold-standard assessments, and study-specific, serum-equivalency values for clinical relevance of DBS-derived values. Concurrent venipuncture serum and DBS samples (n = 150 adults) were assayed in Clinical Laboratory Improvement Amendments-certified and DBS laboratories, respectively. Time controls of DBS standard samples were assayed single-blind along with test samples. Linear regression analyses evaluated DBS-to-serum equivalency values; agreement and bias were assessed via Bland-Altman plots. Linear regressions of venipuncture values on DBS-to-serum equivalencies provided R(2) values for total cholesterol, high-density lipoprotein cholesterol (HDL-C), and C-reactive protein (CRP) of 0.484, 0.118, and 0.666, respectively. Bland-Altman plots revealed minimal systematic bias between DBS-to-serum and venipuncture values; precision worsened at higher mean values of CRP. Time controls revealed little degradation or change in analyte values for HDL-C and CRP over 30 weeks. We concluded that DBS-assessed biomarkers represent a valid alternative to venipuncture assessments. Large studies using DBS should include study-specific serum-equivalency determinations to optimize individual-level sensitivity, the viability of detecting intervention effects, and generalizability in community-level primary prevention interventions. PMID:26652683

  16. Association between fish and shellfish, and omega-3 PUFAs intake and CVD risk factors in middle-aged female patients with type 2 diabetes

    PubMed Central

    Kim, Hyesook; Park, Seokyung; Yang, Hyesu; Choi, Young Ju; Huh, Kap Bum

    2015-01-01

    BACKGROUND/OBJECTIVES This study was performed to investigate the association between the dietary intake of fish and shellfish, and omega-3 polyunsaturated fatty acids (PUFAs) and cardiovascular disease (CVD) risk factors in the middle-aged Korean female patients with Type 2 diabetes (T2D). SUBJECTS/METHODS A cross-sectional analysis was performed with 356 female patients (means age: 55.5 years), who were recruited from the Huh's Diabetes Clinic in Seoul, Korea between 2005 and 2011. The dietary intake was assessed by a validated semi-quantitative food frequency questionnaire and analyzed using the Computer Aided Nutritional Analysis program (CAN-Pro) version 4.0 software. RESULTS In a multiple regression analysis after the adjustment for confounding factors such as age, BMI, duration of diagnosed T2D, alcohol consumption, fiber intake, sodium intake, and total energy intake, fish and shellfish intake of the subjects was negatively associated with triglyceride and pulse wave velocity (PWV). Omega-3 PUFAs intake was negatively associated with triglyceride, systolic blood pressures, diastolic blood pressures, and PWV. The multiple logistic regression analysis with the covariates showed a significant inverse relationship between the omega-3 PUFAs consumption and prevalence of hypertriglyceridemia [OR (95% CI) for greater than the median compared to less than the median: 0.395 (0.207-0.753)]. CONCLUSIONS These results suggest that the consumption of fish and shellfish, good sources of omega-3 PUFAs, may reduce the risk factors for CVD in the middle-aged female patients with T2D. PMID:26425279

  17. Long-term Absolute Risk of Cervical Intraepithelial Neoplasia Grade 3 or Worse Following Human Papillomavirus Infection: Role of Persistence

    PubMed Central

    Frederiksen, Kirsten; Munk, Christian; Iftner, Thomas

    2010-01-01

    Background Infection with high-risk human papillomavirus (HPV) is the main cause of high-grade cervical intraepithelial neoplasia (CIN) and cancer. It has been suggested that information about high-risk HPV type–specific infection might make cervical cancer screening more effective. Persistent HPV infection could also be a useful screening marker. We estimated the long-term risk of high-grade CIN after one-time detection of high-risk HPV DNA and after persistent infection with individual high-risk HPV types. Methods A cohort of 8656 women from the general population of Denmark was examined twice, 2 years apart (first study examination: May 15, 1991, to January 31, 1993; second study examination: October 1, 1993, to January 31, 1995). The women underwent a gynecological examination and cervical cytology and had swabs taken for HPV DNA analysis by the Hybrid Capture 2 and line probe assays. The women were followed up through the nationwide Danish Pathology Data Bank for cervical neoplasia for up to 13.4 years. The absolute risk of developing cervical lesions before a given time was estimated as a function of time. Results For women with normal cytological findings who were concurrently HPV16 DNA positive at the second examination, the estimated probability of developing CIN grade 3 (CIN3) or worse within 12 years of follow-up was 26.7% (95% confidence interval [CI] = 21.1% to 31.8%). The corresponding risks among those infected with HPV18 was 19.1% (95% CI = 10.4% to 27.3%), with HPV31 was 14.3% (95% CI = 9.1% to 19.4%), and with HPV33 was 14.9% (95% CI = 7.9% to 21.1%). The absolute risk of CIN3 or worse after infection with high-risk HPV types other than HPV16, HPV18, HPV31, or HPV33 was 6.0% (95% CI = 3.8% to 8.3%). The estimated absolute risk for CIN3 or cancer within 12 years of the second examination among women who were HPV16 DNA positive at both examinations was 47.4% (95% CI = 34.9% to 57.5%); by contrast, the risk of CIN3 or worse following a negative

  18. Validation of biomarkers of CVD risk from dried blood spots in community-based research: Methodologies and study-specific serum equivalencies

    PubMed Central

    Samuelsson, Laura B.; Hall, Martica H.; McLean, Shakir; Porter, James H.; Berkman, Lisa; Marino, Miguel; Sembajwe, Grace; McDade, Thomas W.; Buxton, Orfeu M.

    2016-01-01

    Objective Dried blood spot (DBS) methodology offers significant advantages over venipuncture in vulnerable populations or large-scale studies, including reduced participant burden and higher response rates. Uncertainty about validity of cardiovascular risk biomarkers remains a barrier to wide-scale use. We determined the validity of DBS-derived biomarkers of CVD risk versus gold-standard assessments, and study-specific, serum-equivalency values for clinical relevance of DBS-derived values. Methods Concurrent venipuncture serum and DBS samples (n=150 adults) were assayed in CLIA-certified and DBS laboratories, respectively. Time controls of DBS standard samples were assayed single-blind along with test samples. Linear regression analyses evaluated DBS-to-serum equivalency values; agreement and bias were assessed via Bland-Altman plots. Results Linear regressions of venipuncture values on DBS-to-serum equivalencies provided R2 values for TC, HDL-C, CRP of 0.484, 0.118, 0.666, respectively. Bland-Altman plots revealed minimal systematic bias between DBS-to-serum and venipuncture values; precision worsened at higher mean values of CRP. Time controls reveal little degradation or change in analyte values for HDL-C and CRP over 30 weeks. Conclusions DBS-assessed biomarkers represent a valid alternative to venipuncture assessments. Large studies using DBS should include study-specific serum-equivalency determinations to optimize individual-level sensitivity, viability of detecting intervention effects, and generalizability in community-level, primary prevention interventions. PMID:26652683

  19. Possible association between ocular chloramphenicol and aplastic anaemia—the absolute risk is very low

    PubMed Central

    Laporte, Joan-Ramon; Vidal, Xavier; Ballarín, Elena; Ibáñez, Luisa

    1998-01-01

    Aims To determine whether topical ocular chloramphenicol increases the risk of aplastic anaemia and to estimate the magnitude of this risk, if any. Methods Population-based prospective case-control surveillance of aplastic anaemia in a community of 4.2 million inhabitants from 1980 to 1995 (67.2 million person-years) plus case-population estimate of the risk, based on sales figures of ocular chloramphenicol in the study area during the study period. Results One hundred and forty-five patients with aplastic anaemia and 1,226 controls were included in the analysis. Three cases (2.1%) and 5 controls (0.4%) had been exposed to ocular chloramphenicol during the relevant etiological period. The adjusted odds ratio was 3.77 (95% confidence interval, 0.84–16.90). Two cases had also been exposed to other known causes of aplastic anaemia. The incidence of aplastic anaemia among users of ocular chloramphenicol was 0.36 cases per million weeks of treatment. The incidence among non users was 0.04 cases per million weeks. Conclusions An association between ocular chloramphenicol and aplastic anaemia cannot be excluded. However, the risk is less than one per million treatment courses. PMID:9723830

  20. Childhood obesity: the impact on long-term risk of metabolic and CVD is not necessarily inevitable.

    PubMed

    McMullen, Sarah

    2014-08-01

    The worldwide prevalence of overweight and obesity in the adult population is estimated to be 35%. These trends are reflected in childhood obesity prevalence, and the potential impact of early-onset obesity is of great concern. The aim of this review was to investigate the long-term implications of childhood obesity for metabolic and cardiovascular health, focusing on the independent contribution of childhood obesity to adult disease risk, as distinct from associations mediated by tracking of obesity across the lifespan. The data systematically reviewed provide little evidence to suggest that childhood overweight and obesity are independent risk factors for metabolic and cardiovascular risk during adulthood. Instead, the data demonstrate that the relationships observed are dependent on tracking of BMI between childhood and adulthood, alongside persistence of dietary patterns and physical activity. Adjustment for adult BMI uncovers unexpected negative associations between childhood BMI and adult disease, suggesting a protective effect of childhood obesity at any given level of adult BMI. Further work is required to explain these findings, both in terms of pathways and statistical artefacts. To conclude, it must be stressed that it is not suggested that childhood obesity is without negative consequence. Childhood obesity is clearly associated with a range of adverse physical and psychological outcomes. However, the data are important in supporting a positive message that the long-term consequences of childhood obesity are avoidable; and that there remains opportunity for intervention across the lifespan. This nuance in understanding long-term risk is important when considering the effectiveness of interventions at different stages of the lifespan. PMID:25027289

  1. Predicted 10-year risk of cardiovascular disease is influenced by the risk equation adopted: a cross-sectional analysis

    PubMed Central

    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

    2014-01-01

    Background Validated risk equations are currently recommended to assess individuals to determine those at ‘high risk’ of cardiovascular disease (CVD). However, there is no longer a risk ‘equation of choice’. Aim This study examined the differences between four commonly-used CVD risk equations. Design and setting Cross-sectional analysis of individuals who participated in a workplace-based risk assessment in Carmarthenshire, south Wales. Method Analysis of 790 individuals (474 females, 316 males) with no prior diagnosis of CVD or diabetes. Ten-year CVD risk was predicted by entering the relevant variables into the QRISK2, Framingham Lipids, Framingham BMI, and JBS2 risk equations. Results The Framingham BMI and JBS2 risk equations predicted a higher absolute risk than the QRISK2 and Framingham Lipids equations, and CVD risk increased concomitantly with age irrespective of which risk equation was adopted. Only a small proportion of females (0–2.1%) were predicted to be at high risk of developing CVD using any of the risk algorithms. The proportion of males predicted at high risk ranged from 5.4% (QRISK2) to 20.3% (JBS2). After age stratification, few differences between isolated risk factors were observed in males, although a greater proportion of males aged ≥50 years were predicted to be at ‘high risk’ independent of risk equation used. Conclusions Different risk equations can influence the predicted 10-year CVD risk of individuals. More males were predicted at ‘high risk’ using the JBS2 or Framingham BMI equations. Consideration should also be given to the number of isolated risk factors, especially in younger adults when evaluating CVD risk. PMID:25267049

  2. Health Benefits of Reducing Sugar-Sweetened Beverage Intake in High Risk Populations of California: Results from the Cardiovascular Disease (CVD) Policy Model

    PubMed Central

    Mekonnen, Tekeshe A.; Odden, Michelle C.; Coxson, Pamela G.; Guzman, David; Lightwood, James; Wang, Y. Claire; Bibbins-Domingo, Kirsten

    2013-01-01

    Background Consumption of sugar-sweetened beverage (SSB) has risen over the past two decades, with over 10 million Californians drinking one or more SSB per day. High SSB intake is associated with risk of type 2 diabetes, obesity, hypertension, and coronary heart disease (CHD). Reduction of SSB intake and the potential impact on health outcomes in California and among racial, ethnic, and low-income sub-groups has not been quantified. Methods We projected the impact of reduced SSB consumption on health outcomes among all Californians and California subpopulations from 2013 to 2022. We used the CVD Policy Model – CA, an established computer simulation of diabetes and heart disease adapted to California. We modeled a reduction in SSB intake by 10–20% as has been projected to result from proposed penny-per-ounce excise tax on SSB and modeled varying effects of this reduction on health parameters including body mass index, blood pressure, and diabetes risk. We projected avoided cases of diabetes and CHD, and associated health care cost savings in 2012 US dollars. Results Over the next decade, a 10–20% SSB consumption reduction is projected to result in a 1.8–3.4% decline in the new cases of diabetes and an additional drop of 0.5–1% in incident CHD cases and 0.5–0.9% in total myocardial infarctions. The greatest reductions are expected in African Americans, Mexican Americans, and those with limited income regardless of race and ethnicity. This reduction in SSB consumption is projected to yield $320–620 million in medical cost savings associated with diabetes cases averted and an additional savings of $14–27 million in diabetes-related CHD costs avoided. Conclusions A reduction of SSB consumption could yield substantial population health benefits and cost savings for California. In particular, racial, ethnic, and low-income subgroups of California could reap the greatest health benefits. PMID:24349119

  3. Applying Health Locus of Control and Latent Class Modelling to food and physical activity choices affecting CVD risk.

    PubMed

    Grisolía, José M; Longo, Alberto; Hutchinson, George; Kee, Frank

    2015-05-01

    Health Locus of Control (HLC) classifies our beliefs about the connection between our actions and health outcomes (Skinner, 1996) into three categories: "internal control", corresponding to health being the result of an individual's effort and habits; "control by powerful others", whereby health depends on others, such as doctors; and "chance control", according to which health depends on fate and chance. Using Choice Experiments we investigate the relationship between HLC and willingness to change lifestyle, in terms of eating habits, physical activity and associated cardiovascular disease risk, in a 384 person sample representative of the 40-65 aged population of Northern Ireland administered between February and July 2011. Using latent class analysis we identify three discrete classes of people based on their HLC: the first class is sceptical about their capacity to control their health and certain unhealthy habits. Despite being unsatisfied with their situation, they are reluctant to accept behaviour changes. The second is a group of individuals unhappy with their current situation but willing to change through exercise and diet. Finally, a group of healthy optimists is identified, who are satisfied with their current situation but happy to take more physical activity and improve their diet. Our findings show that any policy designed to modify people's health related behaviour should consider the needs of this sceptical class which represents a considerable proportion of the population in the region. PMID:25779694

  4. Using image-based flow cytometry to measure monocyte oxidized LDL phagocytosis: A potential risk factor for CVD?

    PubMed

    Henning, Andrea L; Venable, Adam S; Prado, Eric A; Best Sampson, Jill N; McFarlin, Brian K

    2015-08-01

    Obesity and cardiovascular disease is a worldwide health concern that has been a major focus in research for several decades. Among these diseases, atherosclerosis is one of the leading causes of death and disability nationwide. Circulating monocytes are believed to be primary cells responsible for foam cell formation. The present report describes a novel method for measuring monocyte oxLDL phagocytosis capacity using image-based flow cytometry. Human venous blood monocytes were incubated with different concentrations of oxLDL for different lengths of time to optimize the assay. High (post-meal) and low (pre-meal) responder samples were generated by feeding human subjects a high-fat (~85% of daily fat allowance), high-calorie (~65% of daily calorie needs) meal. This is a relevant model with respect to obesity and risk of developing atherogenesis. After the functional assay, classic (CD14+/CD16-) and pro-inflammatory (CD14+/CD16+) monocytes were assessed for oxLDL uptake, adhesion molecule expression (CD11b and CD18), and scavenger receptor expression (CD36) using an image-based flow cytometer (FlowSight). The present method represents a novel advance in methods available to detect the propensity of circulating monocytes to become intima foam cells. We found the assay to be most effective at separating high from low responder samples when using a fixed oxLDL concentration (120 μL/mL) and incubation length (1-h). In a clinical application, this method demonstrated that consuming a single high-fat meal causes an increase in the proportion of monocyte oxLDL phagocytosis and their adhesion capacity, suggesting a higher propensity to become foam cells. PMID:25858228

  5. The effect of dietary changes on distinct components of the metabolic syndrome in a young Sri Lankan population at high risk of CVD.

    PubMed

    Guess, Nicola; Wijesuriya, Mahen; Vasantharajah, Laksha; Gulliford, Martin; Viberti, Giancarlo; Gnudi, Luigi; Karalliedde, Janaka

    2016-08-01

    South Asian populations are predisposed to early onset of the metabolic syndrome. Lifestyle intervention programmes have demonstrated a reduction in the metabolic syndrome and CVD risk; however, the most effective components of the multi-faceted lifestyle interventions are unknown. We studied 2637 Sri Lankan males (n 1237) and females (n 1380), with a mean BMI of 23·9 (sd 4·2) kg/m2, aged 22·5 (sd 10·0) years, who had participated in a 5-year lifestyle-modification programme to examine the effect of dietary changes on distinct components of the metabolic syndrome. The dietary intervention comprised advice to replace polished starches with unpolished starches, high-fat meat and dairy products with low-fat products and high-sugar beverages and snacks with low-sugar varieties. For the purposes of this analysis, data from the control and intensive lifestyle groups were combined. Anthropometric and biochemical data were recorded, and a FFQ was completed annually. Multiple regression was used to determine the effect of the dietary changes on distinct components of the metabolic syndrome. The ratio unpolished:polished rice was inversely related to change in fasting glucose (β=-0·084, P=0·007) and TAG (β=-0·084, P=0·005) and positively associated with change in HDL-cholesterol (β=0·066, P=0·031) at the 5-year follow-up after controlling for relevant confounders. Red meat intake was positively associated with fasting glucose concentrations (β=0·05, P=0·017), whereas low-fat (β=-0·046, P=0·018) but not high-fat dairy products (β=0·003, P=0·853) was inversely related to glucose tolerance at the follow-up visit. Replacement of polished with unpolished rice may be a particularly effective dietary advice in this and similar populations. PMID:27358019

  6. Diet and lifestyle in CVD prevention and treatment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in developed countries and more recently in developing countries. Modifications to habitual dietary patterns and lifestyle behaviors (physical activity and tobacco use) can strongly influence the risk of developing CVD. Thi...

  7. Effect of RAAS blockers on adverse clinical outcomes in high CVD risk subjects with atrial fibrillation: A meta-analysis and systematic review of randomized controlled trials.

    PubMed

    Chaugai, Sandip; Sherpa, Lhamo Yanchang; Sepehry, Amir A; Arima, Hisatomi; Wang, Dao Wen

    2016-06-01

    Recent studies have demonstrated that atrial fibrillation significantly increases the risk of adverse clinical outcomes in high cardiovascular disease risk subjects. Application of renin-angiotensin-aldosterone system blockers for prevention of recurrence of atrial fibrillation and adverse clinical outcomes in subjects with atrial fibrillation is a theoretically appealing concept. However, results of clinical trials evaluating the effect of renin-angiotensin-aldosterone blockers on adverse clinical outcomes in high cardiovascular disease risk subjects with atrial fibrillation remain inconclusive.A pooled study of 6 randomized controlled trials assessing the efficacy of renin-angiotensin-aldosterone blockers on subjects with atrial fibrillation was performed.A total of 6 randomized controlled trials enrolled a total of 53,510 patients followed for 1 to 5 years. RAAS blockade therapy was associated with 14% reduction in the incidence of heart failure (OR: 0.86, [95%CI: 0.76- 0.97], P=0.018) and 17% reduction in the incidence of CVE (OR: 0.83, [95%CI: 0.70-0.99], P = 0.038). The corresponding decline in absolute risk against heart failure (ARR: 1.4%, [95%CI: 0.2-2.6%], P = 0.018) and CVE (ARR: 3.5%, [95%CI: 0.0-6.9%], P = 0.045) in the AF group was much higher than the non-AF group for heart failure (ARR: 0.4%, [95%CI: 0.0-0.7%], P = 0.057) and CVE (ARR: 1.6%, [95%CI: -0.1% to 3.3%], P = 0.071). No significant effect was noted on all-cause or cardiovascular mortality, stroke, or myocardial infarction.This study suggests that RAAS blockade offers protection against heart failure and cardiovascular events in high cardiovascular disease risk subjects with atrial fibrillation. PMID:27368043

  8. Absolute quantification of the pretreatment PML-RARA transcript defines the relapse risk in acute promyelocytic leukemia.

    PubMed

    Albano, Francesco; Zagaria, Antonella; Anelli, Luisa; Coccaro, Nicoletta; Tota, Giuseppina; Brunetti, Claudia; Minervini, Crescenzio Francesco; Impera, Luciana; Minervini, Angela; Cellamare, Angelo; Orsini, Paola; Cumbo, Cosimo; Casieri, Paola; Specchia, Giorgina

    2015-05-30

    In this study we performed absolute quantification of the PML-RARA transcript by droplet digital polymerase chain reaction (ddPCR) in 76 newly diagnosed acute promyelocytic leukemia (APL) cases to verify the prognostic impact of the PML-RARA initial molecular burden. ddPCR analysis revealed that the amount of PML-RARA transcript at diagnosis in the group of patients who relapsed was higher than in that with continuous complete remission (CCR) (272 vs 89.2 PML-RARA copies/ng, p = 0.0004, respectively). Receiver operating characteristic analysis detected the optimal PML-RARA concentration threshold as 209.6 PML-RARA/ng (AUC 0.78; p < 0.0001) for discriminating between outcomes (CCR versus relapse). Among the 67 APL cases who achieved complete remission after the induction treatment, those with >209.6 PML-RARA/ng had a worse relapse-free survival (p = 0.0006). At 5-year follow-up, patients with >209.6 PML-RARA/ng had a cumulative incidence of relapse of 50.3% whereas 7.5% of the patients with suffered a relapse (p < 0.0001). Multivariate analysis identified the amount of PML-RARA before induction treatment as the sole independent prognostic factor for APL relapse.Our results show that the pretreatment PML-RARA molecular burden could therefore be used to improve risk stratification in order to develop more individualized treatment regimens for high-risk APL cases. PMID:25944686

  9. 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…

  10. 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

    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. PMID:27005878

  11. High post-treatment absolute monocyte count predicted hepatocellular carcinoma risk in HCV patients who failed peginterferon/ribavirin therapy.

    PubMed

    Chen, Tsung-Ming; Lin, Chun-Che; Huang, Pi-Teh; Wen, Chen-Fan

    2016-06-01

    Salient studies have investigated the association between host inflammatory response and cancer. This study was conducted to test the hypothesis that peripheral absolute monocyte counts (AMC) could impart an increased risk of hepatocellular carcinoma (HCC) development in hepatitis C virus (HCV)-infected patients after a failed peginterferon/ribavirin (PR) combination therapy. A total of 723 chronic HCV-infected patients were treated with PR, of which 183 (25.3 %) patients did not achieve a sustained virological response (non-SVR). Post-treatment AMC values were measured at 6 months after end of PR treatment. Fifteen (2.8 %) of 540 patients with an SVR developed HCC during a median follow-up period of 41.4 months, and 14 (7.7 %) of 183 non-SVR patients developed HCC during a median follow-up of 36.8 months (log rank test for SVR vs. non-SVR, P = 0.002). Cox regression analysis revealed that post-treatment AFP level (HR 1.070; 95 % CI = 1.024-1.119, P = 0.003) and post-treatment aspartate aminotransferase (AST)-to-platelet ratio index (APRI) ≥0.5 (HR 4.401; 95 % CI = 1.463-13.233, P = 0.008) were independent variables associated with HCC development for SVR patients. For non-SVR patients, diabetes (HR 5.750; 95 % CI = 1.387-23.841, P = 0.016), post treatment AMC ≥370 mm(-3) (HR 5.805; 95 % CI = 1.268-26.573, P = 0.023), and post-treatment APRI ≥1.5 (HR 10.905; 95 % CI = 2.493-47.697, P = 0.002) were independent risks associated with HCC. In conclusion, post-treatment AMC has a role in prognostication of HCC development in HCV-infected patients who failed to achieve an SVR after PR combination therapy. PMID:26662957

  12. Corresponding waist circumference and body mass index values based on 10-year absolute type 2 diabetes risk in an Australian Aboriginal community

    PubMed Central

    Adegbija, Odewumi; Hoy, Wendy E; Wang, Zhiqiang

    2015-01-01

    Objective There is a lack of waist circumference (WC) thresholds to identify Aboriginal individuals at high risk of type 2 diabetes. We generated gender-specific WC values with equivalent 10-year absolute risk of type 2 diabetes as body mass index (BMI) points in an Australian Aboriginal community to contribute to guidelines needed for establishing WC cut-off points for Aboriginals. Research design and methods A cohort of 803 adult participants free from type 2 diabetes in an Aboriginal community was followed up for up to 20 years. We derived WC values with absolute risks equivalent for the development of type 2 diabetes as BMI values (20–35 kg/m2) using the Weibull accelerated failure-time model. Results After a mean follow-up of 15.7 years, 110 participants developed type 2 diabetes. Absolute risk of type 2 diabetes increased as WC increased, ranging from 3.52% (WC=77.5 cm) to 14.14% (WC=119.9 cm) in males, and 5.04% (WC=79.5 cm) to 24.25% (WC=113.7 cm) in females. In males, WC values with same absolute risks of type 2 diabetes as BMI values were 77.5 cm for BMI=20 kg/m2, 91.5 cm for BMI=25 kg/m2 (overweight threshold), 105.7 cm for BMI=30 kg/m2 (obesity threshold) and 119.9 cm for BMI=35 kg/m2. In females, WC values were 79.5 cm for BMI=20 kg/m2, 90.9 cm for BMI=25 kg/m2, 102.3 cm for BMI=30 kg/m2 and 113.7 cm for BMI=35 kg/m2. Interaction between WC and gender was not statistically significant (p=0.53). Conclusions The absolute risk of type 2 diabetes increased with higher WC measured at baseline screening. Males were not significantly different from females in the association between WC and type 2 diabetes. Our findings are useful contributions for future establishment of WC cut-off points for identifying high-risk individuals in Aboriginal people. PMID:26405557

  13. CVD amorphous silicon solar cells

    SciTech Connect

    Hegedus, S.S.; Baron, B.N.; Rocheleau, R.E.

    1984-05-01

    Development of all-CVD TCO/p-i-n/metal/substrate a-Si devices made by CVD from disilane is reported. The reactor and conditions for depositing device quality CVD a-Si at growth rates up to 10 A/sec are described. Conductivity, optical properties and density of states of CVD i layers are described. Photovoltaic device characteristics of all - CVD and hybrid (CVD/GD) pin and nip devices are compared. Efficiencies up to 4% were achieved. An analysis of collection efficiency indicates a hole ..mu../tau/ of 1 - 4 X 10/sup -9/ cm/sup 2//V. Cell performance is consistent with a series connected double junction model.

  14. Absolute Zero

    NASA Astrophysics Data System (ADS)

    Donnelly, Russell J.; Sheibley, D.; Belloni, M.; Stamper-Kurn, D.; Vinen, W. F.

    2006-12-01

    Absolute Zero is a two hour PBS special attempting to bring to the general public some of the advances made in 400 years of thermodynamics. It is based on the book “Absolute Zero and the Conquest of Cold” by Tom Shachtman. Absolute Zero will call long-overdue attention to the remarkable strides that have been made in low-temperature physics, a field that has produced 27 Nobel Prizes. It will explore the ongoing interplay between science and technology through historical examples including refrigerators, ice machines, frozen foods, liquid oxygen and nitrogen as well as much colder fluids such as liquid hydrogen and liquid helium. A website has been established to promote the series: www.absolutezerocampaign.org. It contains information on the series, aimed primarily at students at the middle school level. There is a wealth of material here and we hope interested teachers will draw their student’s attention to this website and its substantial contents, which have been carefully vetted for accuracy.

  15. Homocysteine, B-vitamins and CVD.

    PubMed

    McNulty, Helene; Pentieva, Kristina; Hoey, Leane; Ward, Mary

    2008-05-01

    There is considerable interest in plasma homocysteine (tHcy) as a CVD risk factor. Although the secondary prevention trials published to date have been inconclusive in confirming a benefit of tHcy-lowering treatment with B-vitamins on CVD events generally, such studies are widely recognised to have been insufficiently powered to detect a significant effect for the predicted magnitude of association between tHcy and heart disease risk, and therefore cannot be interpreted as evidence that no relationship exists. In fact, a recent meta-analysis of clinical trials has confirmed that folic acid supplementation reduces the risk of stroke, particularly in individuals without a history of stroke. Evidence supporting a causal relationship between elevated tHcy and heart disease also comes from genetic studies. The most important genetic determinant of tHcy in the general population is the common C677T variant in methylenetetrahydrofolate reductase (MTHFR) that results in higher tHcy. Individuals with the homozygous mutant (TT) genotype have a significantly higher (14-21%) risk of heart disease. Plasma tHcy is very responsive to intervention with the B-vitamins required for its metabolism, in particular folic acid, and to a lesser extent vitamins B12 and B6. Thus, although primarily aimed at reducing neural-tube defects, folic acid fortification may have an important role in the primary prevention of CVD via tHcy lowering. Besides folate, riboflavin is required as a cofactor for MTHFR and enhanced riboflavin status results in a marked lowering in tHcy specifically in individuals with the TT genotype, presumably by neutralising the variant form of the enzyme. About 10% of the UK and Irish populations have the TT genotype. In the present paper the potential role of folate and related B-vitamins in the primary prevention of CVD and the implications for nutrition policy are explored. PMID:18412997

  16. Absolute Summ

    NASA Astrophysics Data System (ADS)

    Phillips, Alfred, Jr.

    Summ means the entirety of the multiverse. It seems clear, from the inflation theories of A. Guth and others, that the creation of many universes is plausible. We argue that Absolute cosmological ideas, not unlike those of I. Newton, may be consistent with dynamic multiverse creations. As suggested in W. Heisenberg's uncertainty principle, and with the Anthropic Principle defended by S. Hawking, et al., human consciousness, buttressed by findings of neuroscience, may have to be considered in our models. Predictability, as A. Einstein realized with Invariants and General Relativity, may be required for new ideas to be part of physics. We present here a two postulate model geared to an Absolute Summ. The seedbed of this work is part of Akhnaton's philosophy (see S. Freud, Moses and Monotheism). Most important, however, is that the structure of human consciousness, manifest in Kenya's Rift Valley 200,000 years ago as Homo sapiens, who were the culmination of the six million year co-creation process of Hominins and Nature in Africa, allows us to do the physics that we do. .

  17. Effects of Cardiovascular Disease Risk Communication for Patients With Type 2 Diabetes on Risk Perception in a Randomized Controlled Trial

    PubMed Central

    Welschen, Laura M.C.; Bot, Sandra D.M.; Kostense, Piet J.; Dekker, Jacqueline M.; Timmermans, Daniëlle R.M.; van der Weijden, Trudy; Nijpels, Giel

    2012-01-01

    OBJECTIVE Patients with type 2 diabetes mellitus (T2DM) underestimate their risk of developing severe complications, and they do not always understand the risk communication by their caregivers. The aim of this study was to investigate the effects of an intervention focused on the communication of the absolute 10-year risk of developing cardiovascular disease (CVD) in patients with T2DM. RESEARCH DESIGN AND METHODS A randomized controlled trial was performed in T2DM patients newly referred to the Diabetes Care System (DCS) West-Friesland, a managed-care system in the Netherlands. The intervention group (n = 131) received a six-step CVD risk communication. Control subjects (n = 130) received standard managed care. The primary outcome measure was appropriateness of risk perception (difference between actual CVD risk calculated by the UK Prospective Diabetes Study risk engine and risk perception). Secondary outcome measures were illness perceptions, attitude and intention to change behavior, satisfaction with the communication, and anxiety and worry about CVD risk. Patients completed questionnaires at baseline, at 2 weeks (immediately after the intervention), and at 12 weeks. RESULTS Appropriateness of risk perception improved between the intervention and control groups at 2 weeks. This effect disappeared at 12 weeks. No effects were found on illness perceptions, attitude and intention to change behavior, or anxiety and worry about CVD risk. Patients in the intervention group were significantly more satisfied with the communication. CONCLUSIONS This risk communication method improved patients’ risk perception at 2 weeks but not at 12 weeks. Negative effects were not found, as patients did not become anxious or worried after the CVD risk communication. PMID:22923669

  18. C(1) metabolism and CVD outcomes in older adults.

    PubMed

    McNulty, Helene; Strain, J J; Pentieva, Kristina; Ward, Mary

    2012-05-01

    CVD is the most common cause of death in people over 65 years. This review considers the latest evidence for a potential protective effect of C(1) donors (folate and the metabolically related B-vitamins) in CVD. Such an effect may or may not be mediated via the role of these nutrients in maintaining plasma homocysteine concentrations within a desirable range. Despite predictions from epidemiological studies that lowering plasma homocysteine would reduce cardiovascular risk, several secondary prevention trials in at-risk patients published since 2004 have failed to demonstrate a benefit of homocysteine-lowering therapy with B-vitamins on CVD events generally. All these trials were performed in CVD patients with advanced disease; thus current evidence suggests that intervention with high-dose folic acid is of no benefit in preventing another event, at least in the case of heart disease. The evidence at this time, however, is stronger for stroke, with meta-analyses of randomised trials showing that folic acid reduces the risk of stroke, particularly in people with no history of stroke. Genetic studies provide convincing evidence to support a causal relationship between sub-optimal B-vitamin status and CVD. People homozygous for the common C677T variant in the gene encoding the folate-metabolising enzyme, methylenetetrahydrofolate reductase (MTHFR), typically have a 14-21% higher risk of CVD. Apart from folate, riboflavin is required as a co-factor for MTHFR. New evidence shows that riboflavin intervention results in marked lowering of blood pressure, specifically in patients with the MTHFR 677TT genotype. This novel gene-nutrient interaction may provide insights as to the mechanism that links C(1) metabolism with CVD outcomes. PMID:22152927

  19. Cardiovascular disease risk factors in relation to smoking behaviour and history: a population-based cohort study

    PubMed Central

    Keto, Jaana; Ventola, Hanna; Jokelainen, Jari; Linden, Kari; Keinänen-Kiukaanniemi, Sirkka; Timonen, Markku; Ylisaukko-oja, Tero; Auvinen, Juha

    2016-01-01

    Objective To investigate how individual risk factors for cardiovascular disease (CVD) (blood pressure, lipid levels, body mass index, waist and hip circumference, use of antihypertensive or hypolipidemic medication, and diagnosed diabetes) differ in people aged 46 years with different smoking behaviour and history. Methods This population-based cohort study is based on longitudinal data from the Northern Finland Birth Cohort 1966 project. Data were collected at the 31-year and 46-year follow-ups, when a total of 5038 and 5974 individuals participated in clinical examinations and questionnaires. Data from both follow-ups were available for 3548 participants. In addition to individual CVD risk factors, Framingham and Systematic Coronary Risk Evaluation (SCORE) algorithms were used to assess the absolute risk of a CVD event within the next decade. Results The differences in individual risk factors for CVD reached statistical significance for some groups, but the differences were not consistent or clinically significant. There were no clinically significant differences in CVD risk as measured by Framingham or SCORE algorithms between never smokers, recent quitters and former smokers (7.5%, 7.4%, 8.1% for men; 3.3%, 3.0%, 3.2% for women; p<0.001). Conclusions The effect of past or present smoking on individual CVD risk parameters such as blood pressure and cholesterol seems to be of clinically minor significance in people aged 46 years. In other words, smoking seems to be above all an independent risk factor for CVD in the working-age population. Quitting smoking in working age may thus reduce calculated CVD risk nearly to the same level with people who have never smoked. PMID:27493759

  20. Prediction of absolute risk of fragility fracture at 10 years in a Spanish population: validation of the WHO FRAX ™ tool in Spain

    PubMed Central

    2011-01-01

    Background Age-related bone loss is asymptomatic, and the morbidity of osteoporosis is secondary to the fractures that occur. Common sites of fracture include the spine, hip, forearm and proximal humerus. Fractures at the hip incur the greatest morbidity and mortality and give rise to the highest direct costs for health services. Their incidence increases exponentially with age. Independently changes in population demography, the age - and sex- specific incidence of osteoporotic fractures appears to be increasing in developing and developed countries. This could mean more than double the expected burden of osteoporotic fractures in the next 50 years. Methods/Design To assess the predictive power of the WHO FRAX™ tool to identify the subjects with the highest absolute risk of fragility fracture at 10 years in a Spanish population, a predictive validation study of the tool will be carried out. For this purpose, the participants recruited by 1999 will be assessed. These were referred to scan-DXA Department from primary healthcare centres, non hospital and hospital consultations. Study population: Patients attended in the national health services integrated into a FRIDEX cohort with at least one Dual-energy X-ray absorptiometry (DXA) measurement and one extensive questionnaire related to fracture risk factors. Measurements: At baseline bone mineral density measurement using DXA, clinical fracture risk factors questionnaire, dietary calcium intake assessment, history of previous fractures, and related drugs. Follow up by telephone interview to know fragility fractures in the 10 years with verification in electronic medical records and also to know the number of falls in the last year. The absolute risk of fracture will be estimated using the FRAX™ tool from the official web site. Discussion Since more than 10 years ago numerous publications have recognised the importance of other risk factors for new osteoporotic fractures in addition to low BMD. The extension of a

  1. [The significance of high sensitive C reactive protein as a risk factor for cardiovascular diseases].

    PubMed

    Meguro, Shu; Ishibashi, Midori; Takei, Izumi

    2012-04-01

    Chronic inflammation is involved in the pathogenesis of cardiovascular diseases (CVD). Several prospective studies have indicated that an elevated high sensitive C-reactive protein (hs-CRP) level is a risk factor for CVD. These results were also confirmed by prospective studies in Japan both for primary and secondary prevention. A randomized control study using statins also revealed that lower levels of both LDL cholesterol and hs-CRP were independently related to the incidence of CVD. Recent meta-analysis revealed that hs-CRP was a risk factor not only for CVD but for other diseases including cancers. It revealed that the absolute value of hs-CRP varied among the study populations. The mechanism of how hs-CRP is associated with the pathogenesis of CVD is not fully understood. Generally, inflammation in the vascular wall and the release of inflammatory cytokines from macrophages was considered to the main mechanism, but infection with such as chlamydia or Helicobacter pylori, and periodontal disease have been postulated as the causes of systemic inflammation. Recently, visceral fat accumulation and its cross-interaction with inflammatory cells have been proposed as the cause of systemic inflammation as "innate inflammation". Our original cross sectional studies also showed the correlations of hs-CRP with BMI and triglyceride. Although there is no specific therapy for the reduction of hs-CRP, we have to consider hs-CRP as a risk factor for CVD which complements other classical risk factors. PMID:22686046

  2. CVD Diamond Dielectric Accelerating Structures

    SciTech Connect

    Schoessow, P.; Kanareykin, A.; Gat, R.

    2009-01-22

    The electrical and mechanical properties of diamond make it an ideal candidate material for use in dielectric accelerating structures: high RF breakdown field, extremely low dielectric losses and the highest available thermoconductive coefficient. Using chemical vapor deposition (CVD) cylindrical diamond structures have been manufactured with dimensions corresponding to fundamental TM{sub 01} mode frequencies in the GHz to THz range. Surface treatments are being developed to reduce the secondary electron emission (SEE) coefficient below unity to reduce the possibility of multipactor. The diamond CVD cylindrical waveguide technology developed here can be applied to a variety of other high frequency, large-signal applications.

  3. Exploring the Life Expectancy Increase in Poland in the Context of CVD Mortality Fall: The Risk Assessment Bottom-Up Approach, From Health Outcome to Policies.

    PubMed

    Kobza, Joanna; Geremek, Mariusz

    2015-01-01

    Life expectancy at birth is considered the best mortality-based summary indicator of the health status of the population and is useful for measuring long-term health changes. The objective of this article was to present the concept of the bottom-up policy risk assessment approach, developed to identify challenges involved in analyzing risk factor reduction policies and in assessing how the related health indicators have changed over time. This article focuses on the reasons of the significant life expectancy prolongation in Poland over the past 2 decades, thus includes policy context. The methodology details a bottom-up risk assessment approach, a chain of relations between the health outcome, risk factors, and health policy, based on Risk Assessment From Policy to Impact Dimension project guidance. A decline in cardiovascular disease mortality was a key factor that followed life expectancy prolongation. Among basic factors, tobacco and alcohol consumption, diet, physical activity, and new treatment technologies were identified. Poor health outcomes of the Polish population at the beginning of 1990s highlighted the need of the implementation of various health promotion programs, legal acts, and more effective public health policies. Evidence-based public health policy needs translating scientific research into policy and practice. The bottom-up case study template can be one of the focal tools in this process. Accountability for the health impact of policies and programs and legitimization of the decisions of policy makers has become one of the key questions nowadays in European countries' decision-making process and in EU public health strategy. PMID:26546595

  4. A comparison of Australian rural and metropolitan cardiovascular risk and mortality: the Greater Green Triangle and North West Adelaide population surveys

    PubMed Central

    Tideman, Philip; Taylor, Anne W; Janus, Edward; Philpot, Ben; Clark, Robyn; Peach, Elizabeth; Laatikainen, Tiina; Vartiainen, Erkki; Tirimacco, Rosy; Montgomerie, Alicia; Grant, Janet; Versace, Vincent; Dunbar, James A

    2013-01-01

    Objectives Cardiovascular (CVD) mortality disparities between rural/regional and urban-dwelling residents of Australia are persistent. Unavailability of biomedical CVD risk factor data has, until now, limited efforts to understand the causes of the disparity. This study aimed to further investigate such disparities. Design Comparison of (1) CVD risk measures between a regional (Greater Green Triangle Risk Factor Study (GGT RFS, cross-sectional study, 2004–2006) and an urban population (North West Adelaide Health Study (NWAHS, longitudinal cohort study, 2004–2006); (2) Australian Bureau of Statistics (ABS) CVD mortality rates between these and other Australian regions; and (3) ABS CVD mortality rates by an area-level indicator of socioeconomic status, the Index of Relative Socioeconomic Disadvantage (IRSD). Setting Greater Green Triangle (GGT, Limestone Coast, Wimmera and Corangamite Shires) of South-Western Victoria and North-West Adelaide (NWA). Participants 1563 GGT RFS and 3036 NWAHS stage 2 participants (aged 25–74) provided some information (self-administered questionnaire +/− anthropometric and biomedical measurements). Primary and secondary outcome measures Age-group specific measures of absolute CVD risk, ABS CVD mortality rates by study group and Australian Standard Geographical Classification (ASGC) region. Results Few significant differences in CVD risk between the study regions, with absolute CVD risk ranging from approximately 5% to 30% in the 35–39 and 70–74 age groups, respectively. Similar mean 2003–2007 (crude) mortality rates in GGT (98, 95% CI 87 to 111), NWA (103, 95% CI 96 to 110) and regional Australia (92, 95% CI 91 to 94). NWA mortality rates exceeded that of other city areas (70, 95% CI 69 to 71). Lower measures of socioeconomic status were associated with worse CVD outcomes regardless of geographic location. Conclusions Metropolitan areas do not always have better CVD risk factor profiles and outcomes than rural

  5. Low absolute lymphocyte count and addition of rituximab confer high risk for interstitial pneumonia in patients with diffuse large B-cell lymphoma.

    PubMed

    Huang, Yu-Chung; Liu, Chia-Jen; Liu, Chun-Yu; Pai, Jih-Tung; Hong, Ying-Chung; Teng, Hao-Wei; Hsiao, Liang-Tsai; Chao, Ta-Chung; Gau, Jyh-Pyng; Liu, Jin-Hwang; Hsu, Hui-Chi; Chiou, Tzeon-Jye; Chen, Po-Min; Yu, Yuan-Bin; Tzeng, Cheng-Hwai

    2011-10-01

    Several small-scale studies have reported pulmonary toxicity among patients with diffuse large B-cell lymphoma (DLBCL) receiving rituximab-containing chemotherapy, though whether the use of rituximab predisposes to interstitial pneumonia (IP) remains unclear. This retrospective study was intended to identify the characteristics and risk factors of IP in patients with DLBCL. Between 2000 and 2009, 529 consecutive patients with DLBCL receiving first-line tri-weekly COP- or CHOP-based chemotherapy with or without rituximab were enrolled as subjects. IP was defined as diffuse pulmonary interstitial infiltrates found on computed tomography scans in conjunction with respiratory symptoms. IP was observed in 26 patients (4.9%), six of whom were confirmed with Pneumocystis jirovecii pneumonia. The median number of chemotherapy courses before IP was four cycles. Using multivariate analysis, absolute lymphocyte count less than 1×10(9)/l at diagnosis [odds ratio (OR) 2.75, p=0.014] and the addition of rituximab to chemotherapy (OR 4.56, p=0.003) were identified as independent risk factors for IP. In conclusion, the incidence of IP is increased in patients with DLBCL receiving rituximab-containing chemotherapy. Specific subgroups with lymphopenia at diagnosis may justify close scrutiny to detect pulmonary complications. PMID:21647583

  6. Teaching Absolute Value Meaningfully

    ERIC Educational Resources Information Center

    Wade, Angela

    2012-01-01

    What is the meaning of absolute value? And why do teachers teach students how to solve absolute value equations? Absolute value is a concept introduced in first-year algebra and then reinforced in later courses. Various authors have suggested instructional methods for teaching absolute value to high school students (Wei 2005; Stallings-Roberts…

  7. A methodological survey of the analysis, reporting and interpretation of Absolute Risk ReductiOn in systematic revieWs (ARROW): a study protocol

    PubMed Central

    2013-01-01

    Background Clinicians, providers and guideline panels use absolute effects to weigh the advantages and downsides of treatment alternatives. Relative measures have the potential to mislead readers. However, little is known about the reporting of absolute measures in systematic reviews. The objectives of our study are to determine the proportion of systematic reviews that report absolute measures of effect for the most important outcomes, and ascertain how they are analyzed, reported and interpreted. Methods/design We will conduct a methodological survey of systematic reviews published in 2010. We will conduct a 1:1 stratified random sampling of Cochrane vs. non-Cochrane systematic reviews. We will calculate the proportion of systematic reviews reporting at least one absolute estimate of effect for the most patient-important outcome for the comparison of interest. We will conduct multivariable logistic regression analyses with the reporting of an absolute estimate of effect as the dependent variable and pre-specified study characteristics as the independent variables. For systematic reviews reporting an absolute estimate of effect, we will document the methods used for the analysis, reporting and interpretation of the absolute estimate. Discussion Our methodological survey will inform current practices regarding reporting of absolute estimates in systematic reviews. Our findings may influence recommendations on reporting, conduct and interpretation of absolute estimates. Our results are likely to be of interest to systematic review authors, funding agencies, clinicians, guideline developers and journal editors. PMID:24330779

  8. Electronic properties of CVD diamond

    NASA Astrophysics Data System (ADS)

    Nebel, C. E.

    2003-03-01

    The electronic properties of chemical vapour deposited (CVD) diamond are reviewed based on data measured by transient and spectrally resolved photoconductivity experiments, photo-thermal deflection spectroscopy (PDS) and electron paramagnetic resonance (EPR) where substitutional nitrogen (P1-centre) and carbon defects (H1-centre) are detected. The results show that nominally undoped high quality polycrystalline CVD diamond is a n-type semiconductor due to the presence of substitutional nitrogen. The sub-band-gap optical absorption is governed by amorphous graphite present at grain boundaries. Spectrally resolved photoconductivity experiments measured in the same regime are partially dominated by diamond bulk properties which are comparable to single crystalline Ib and IIa diamond and partially by grain boundaries. Mobilities and drift length of carriers are discussed and compared to properties of single crystalline diamond.

  9. Premature menopause linked to CVD and osteoporosis.

    PubMed

    Park, Claire; Overton, Caroline

    2010-03-01

    Premature menopause affects 1% of women under the age of 40, the usual age of the menopause is 51. Most women will present with irregular periods or no periods at all with or without climacteric symptoms. Around 10% of women present with primary amenorrhoea. A careful history and examination are required. It is important to ask specifically about previous chemotherapy or radiotherapy and to look for signs of androgen excess e.g. polycystic ovarian syndrome, adrenal problems e.g. galactorrhoea and thyroid goitres. Once pregnancy has been excluded, a progestagen challenge test can be performed in primary care. Norethisterone 5 mg tds po for ten days or alternatively medroxyprogesterone acetate 10 mg daily for ten days is prescribed. A withdrawal bleed within a few days of stopping the norethisterone indicates the presence of oestrogen and bleeding more than a few drops is considered a positive withdrawal bleed. The absence of a bleed indicates low levels of oestrogen, putting the woman at risk of CVD and osteoporosis. FSH levels above 30 IU/l are an indicator that the ovaries are failing and the menopause is approaching or has occurred. It should be remembered that FSH levels fluctuate during the month and from one month to the next, so a minimum of two measurements should be made at least four to six weeks apart. The presence of a bleed should not exclude premature menopause as part of the differential diagnosis as there can be varying and unpredictable ovarian function remaining. The progestagen challenge test should not be used alone, but in conjunction with FSH, LH and oestradiol. There is no treatment for premature menopause. Women desiring pregnancy should be referred to a fertility clinic and discussion of egg donation. Women not wishing to become pregnant should be prescribed HRT until the age of 50 to control symptoms of oestrogen deficiency and reduce the risks of osteoporosis and CVD. PMID:20408329

  10. Eosinophil count - absolute

    MedlinePlus

    Eosinophils; Absolute eosinophil count ... the white blood cell count to give the absolute eosinophil count. ... than 500 cells per microliter (cells/mcL). Normal value ranges may vary slightly among different laboratories. Talk ...

  11. Methodology to predict long-term cancer survival from short-term data using Tobacco Cancer Risk and Absolute Cancer Cure models

    NASA Astrophysics Data System (ADS)

    Mould, R. F.; Lederman, M.; Tai, P.; Wong, J. K. M.

    2002-11-01

    Three parametric statistical models have been fully validated for cancer of the larynx for the prediction of long-term 15, 20 and 25 year cancer-specific survival fractions when short-term follow-up data was available for just 1-2 years after the end of treatment of the last patient. In all groups of cases the treatment period was only 5 years. Three disease stage groups were studied, T1N0, T2N0 and T3N0. The models are the Standard Lognormal (SLN) first proposed by Boag (1949 J. R. Stat. Soc. Series B 11 15-53) but only ever fully validated for cancer of the cervix, Mould and Boag (1975 Br. J. Cancer 32 529-50), and two new models which have been termed Tobacco Cancer Risk (TCR) and Absolute Cancer Cure (ACC). In each, the frequency distribution of survival times of defined groups of cancer deaths is lognormally distributed: larynx only (SLN), larynx and lung (TCR) and all cancers (ACC). All models each have three unknown parameters but it was possible to estimate a value for the lognormal parameter S a priori. By reduction to two unknown parameters the model stability has been improved. The material used to validate the methodology consisted of case histories of 965 patients, all treated during the period 1944-1968 by Dr Manuel Lederman of the Royal Marsden Hospital, London, with follow-up to 1988. This provided a follow-up range of 20- 44 years and enabled predicted long-term survival fractions to be compared with the actual survival fractions, calculated by the Kaplan and Meier (1958 J. Am. Stat. Assoc. 53 457-82) method. The TCR and ACC models are better than the SLN model and for a maximum short-term follow-up of 6 years, the 20 and 25 year survival fractions could be predicted. Therefore the numbers of follow-up years saved are respectively 14 years and 19 years. Clinical trial results using the TCR and ACC models can thus be analysed much earlier than currently possible. Absolute cure from cancer was also studied, using not only the prediction models which

  12. Absolute nuclear material assay

    DOEpatents

    Prasad, Manoj K.; Snyderman, Neal J.; Rowland, Mark S.

    2012-05-15

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  13. Absolute nuclear material assay

    DOEpatents

    Prasad, Manoj K.; Snyderman, Neal J.; Rowland, Mark S.

    2010-07-13

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  14. Diamond film by hot filament CVD method

    NASA Technical Reports Server (NTRS)

    Hirose, Y.

    1988-01-01

    Diamond synthesis by the hot filament CVD method is discussed. A hot filament decomposes gas mixtures and oxygen containing organic compounds such as alcohols. which are carbon sources. The resulting thin films, growth mechanisms, and characteristics and problems associated with the hot filament CVD method are analyzed and evaluated.

  15. FTIR monitoring of industrial scale CVD processes

    NASA Astrophysics Data System (ADS)

    Hopfe, V.; Mosebach, H.; Meyer, M.; Sheel, D.; Grählert, W.; Throl, O.; Dresler, B.

    1998-06-01

    The goal is to improve chemical vapour deposition (CVD) and infiltration (CVI) process control by a multipurpose, knowledge based feedback system. For monitoring the CVD/CVI process in-situ FTIR spectroscopic data has been identified as input information. In the presentation, three commonly used, and distinctly different, types of industrial CVD/CVI processes are taken as test cases: (i) a thermal high capacity CVI batch process for manufacturing carbon fibre reinforced SiC composites for high temperature applications, (ii) a continuously driven CVD thermal process for coating float glass for energy protection, and (iii) a laser stimulated CVD process for continuously coating bundles of thin ceramic fibers. The feasibility of the concept with FTIR in-situ monitoring as a core technology has been demonstrated. FTIR monitoring sensibly reflects process conditions.

  16. Electronic properties of CVD and synthetic diamond

    NASA Astrophysics Data System (ADS)

    Nebel, C. E.; Müautnz, J.; Stutzmann, M.; Zachai, R.; Güautttler, H.

    1997-04-01

    Transport and contact properties of synthetic IIb- and intrinsic chemical vapor deposition (CVD) -diamond films are discussed. The samples have been investigated by time-of-flight and transient photoconductivity experiments using Cr/Au contacts. A hole depletion layer at the Cr/Au-IIb-diamond interface and an electron depletion layer at the Cr/Au-CVD-diamond interface is detected. The data indicate that our normally undoped CVD-diamond films are n-type semiconductors. In IIb diamond the mobilities of electrons and holes have been measured, while in CVD diamond no carrier transit can be detected due to the short Schubweg less than or equal to 1 μm. Two trap levels located approximately 190 meV below the conduction band and 670 meV above the valence band are deduced. Electron spin resonance experiments demonstrate that these CVD films are highly defective, containing about 1018 cm-3 carbon related defects (g=2.0029).

  17. CVD diamond layers for electrochemistry

    NASA Astrophysics Data System (ADS)

    Kowalska, M.; Fabisiak, K.; Wrzyszczyński, A.; Banaszak, A.; Szybowicz, M.; Paprocki, K.; Bała, W.; Bylicki, F.

    2014-09-01

    Diamond electrodes of different morphologies and qualities were manufactured by hot filament chemical deposition (HF CVD) techniques by changing the parameters of diamond growth process. The estimation of diamond quality and identification of different carbon phases was performed by Raman spectroscopy measurements. The effect of diamond quality and amorphous carbon phase content on the electrochemical response of an obtained diamond electrode in 0.5 M H2SO4 as supporting electrolyte was investigated by cyclic voltammetry with [Fe(CN)6]4-/3- as a redox probe. The kinetic parameters such as catalytic reaction rate constant k0 and electron transfer coefficient α were determined. The obtained results show that the analytical performance of undoped diamond electrodes can be implemented just by the change of diamond layers quality.

  18. Prevalence of peripheral arterial disease in subjects with moderate cardiovascular risk: Italian results from the PANDORA study Data from PANDORA (Prevalence of peripheral Arterial disease in subjects with moderate CVD risk, with No overt vascular Diseases nor Diabetes mellitus)

    PubMed Central

    2011-01-01

    Background The PANDORA study has recently examined the prevalence of low ankle brachial index (ABI) in subjects with moderate risk of cardiovascular disease. This sub-analysis of the PANDORA study examines the prevalence of asymptomatic peripheral arterial disease (PAD), as determined by ABI, in Italian subjects presenting with moderate cardiovascular risk, in the absence of diabetes or overt vascular disease. Methods PANDORA is a non-interventional, cross-sectional study that was performed in 6 European countries, involving subjects with at least one cardiovascular (CV) risk factor. The primary objective was to evaluate the prevalence of asymptomatic PAD using ABI. For this post-hoc sub-analysis, data were extracted for subjects enrolled in Italy, comprising 51.5% (n = 5298) of subjects from the original PANDORA study. Secondary objectives were to establish the prevalence and treatment of CV risk factors. Results The mean age was 63.9 years and 22.9% (95% CI 21.7-24.0) of subjects presented with asymptomatic PAD. A range of risk factors comprising smoking, hypertension, low HDL-cholesterol, family history of coronary heart disease and habit of moderate-high alcohol intake were significantly associated with asymptomatic PAD (p < 0.0001). Statin treatment had the lowest incidence in Italian subjects. Furthermore, patients treated with statins were significantly less likely to have asymptomatic PAD than those who were not (p = 0.0001). Conclusions Asymptomatic PAD was highly prevalent in Italian subjects, the majority of whom were not candidates for ABI assessment according to current guidelines. Findings from this study suggest that these patients should be carefully examined in clinical practice and ABI measured so that therapeutic interventions known to decrease their CV risk may be offered. Trial registration number ClinicalTrials.gov: NCT00689377 PMID:21981988

  19. CVD silicon carbide mirrors for EUV applications

    NASA Astrophysics Data System (ADS)

    Keski-Kuha, Ritva A.; Osantowski, John F.; Leviton, Douglas B.; Saha, Timo T.; Wright, Geraldine A.; Boucarut, Rene A.; Fleetwood, Charles M.; Madison, Timothy J.

    1995-10-01

    Advances in optical coating and materials technology have made possible the development of instruments with substantially improved efficiency in the extreme ultraviolet (EUV). For example, the development of chemical vapor deposited (CVD) SiC mirrors provides an opportunity to extend the range of normal incidence instruments down to 60 nm. CVD-SiC is a highly polishable material yielding low scatter surfaces. High UV reflectivity and desirable mechanical and thermal properties make CVD-SiC an attractive mirror and/or coating material for EUV applications. The EUV performance of SiC mirrors as well as some strengths and problem areas are discussed.

  20. Saturation of CVD Diamond Detectors

    SciTech Connect

    Lucile S. Dauffy; Richard A. Lerche; Greg J. Schmid; Jeffrey A. Koch; Christopher Silbernagel

    2005-01-01

    A 5 x 0.25 mm Chemical Vapor Deposited (CVD) diamond detector, with a voltage bias of + 250V, was excited by a 400 nm laser (3.1 eV photons) in order to study the saturation of the wafer and its surrounding electronics. In a first experiment, the laser beam energy was increased from a few tens of a pJ to about 100 µJ, and the signal from the diamond was recorded until full saturation of the detection system was achieved. Clear saturation of the detection system was observed at about 40 V, which corresponds with the expected saturation at 10% of the applied bias (250V). The results indicate that the interaction mechanism of the 3.1 eV photons in the diamond (Ebandgap = 5.45 eV) is not a multi-photon process but is linked to the impurities and defects of the crystal. In a second experiment, the detector was irradiated by a saturating first laser pulse and then by a delayed laser pulse of equal or smaller amplitude with delays of 5, 10, and 20 ns. The results suggest that the diamond and associated electronics recover within 10 to 20 ns after a strong saturating pulse.

  1. Fracture Characteristics of Monolayer CVD-Graphene

    PubMed Central

    Hwangbo, Yun; Lee, Choong-Kwang; Kim, Sang-Min; Kim, Jae-Hyun; Kim, Kwang-Seop; Jang, Bongkyun; Lee, Hak-Joo; Lee, Seoung-Ki; Kim, Seong-Su; Ahn, Jong-Hyun; Lee, Seung-Mo

    2014-01-01

    We have observed and analyzed the fracture characteristics of the monolayer CVD-graphene using pressure bulge testing setup. The monolayer CVD-graphene has appeared to undergo environmentally assisted subcritical crack growth in room condition, i.e. stress corrosion cracking arising from the adsorption of water vapor on the graphene and the subsequent chemical reactions. The crack propagation in graphene has appeared to be able to be reasonably tamed by adjusting applied humidity and stress. The fracture toughness, describing the ability of a material containing inherent flaws to resist catastrophic failure, of the CVD-graphene has turned out to be exceptionally high, as compared to other carbon based 3D materials. These results imply that the CVD-graphene could be an ideal candidate as a structural material notwithstanding environmental susceptibility. In addition, the measurements reported here suggest that specific non-continuum fracture behaviors occurring in 2D monoatomic structures can be macroscopically well visualized and characterized. PMID:24657996

  2. Absolute biological needs.

    PubMed

    McLeod, Stephen

    2014-07-01

    Absolute needs (as against instrumental needs) are independent of the ends, goals and purposes of personal agents. Against the view that the only needs are instrumental needs, David Wiggins and Garrett Thomson have defended absolute needs on the grounds that the verb 'need' has instrumental and absolute senses. While remaining neutral about it, this article does not adopt that approach. Instead, it suggests that there are absolute biological needs. The absolute nature of these needs is defended by appeal to: their objectivity (as against mind-dependence); the universality of the phenomenon of needing across the plant and animal kingdoms; the impossibility that biological needs depend wholly upon the exercise of the abilities characteristic of personal agency; the contention that the possession of biological needs is prior to the possession of the abilities characteristic of personal agency. Finally, three philosophical usages of 'normative' are distinguished. On two of these, to describe a phenomenon or claim as 'normative' is to describe it as value-dependent. A description of a phenomenon or claim as 'normative' in the third sense does not entail such value-dependency, though it leaves open the possibility that value depends upon the phenomenon or upon the truth of the claim. It is argued that while survival needs (or claims about them) may well be normative in this third sense, they are normative in neither of the first two. Thus, the idea of absolute need is not inherently normative in either of the first two senses. PMID:23586876

  3. CVD diamond for nuclear detection applications

    NASA Astrophysics Data System (ADS)

    Bergonzo, P.; Brambilla, A.; Tromson, D.; Mer, C.; Guizard, B.; Marshall, R. D.; Foulon, F.

    2002-01-01

    Chemically vapour deposited (CVD) diamond is a remarkable material for the fabrication of radiation detectors. In fact, there exist several applications where other standard semiconductor detectors do not fulfil the specific requirements imposed by corrosive, hot and/or high radiation dose environments. The improvement of the electronic properties of CVD diamond has been under intensive investigations and led to the development of a few applications that are addressing specific industrial needs. Here, we report on CVD diamond-based detector developments and we describe how this material, even though of a polycrystalline nature, is readily of great interest for applications in the nuclear industry as well as for physics experiments. Improvements in the material synthesis as well as on device fabrication especially concern the synthesis of films that do not exhibit space charge build up effects which are often encountered in CVD diamond materials and that are highly detrimental for detection devices. On a pre-industrial basis, CVD diamond detectors have been fabricated for nuclear industry applications in hostile environments. Such devices can operate in harsh environments and overcome limitations encountered with the standard semiconductor materials. Of these, this paper presents devices for the monitoring of the alpha activity in corrosive nuclear waste solutions, such as those encountered in nuclear fuel assembly reprocessing facilities, as well as diamond-based thermal neutron detectors exhibiting a high neutron to gamma selectivity. All these demonstrate the effectiveness of a demanding industrial need that relies on the remarkable resilience of CVD diamond.

  4. Evaluation of Cardiovascular Risk Scores Applied to NASA's Astronant Corps

    NASA Technical Reports Server (NTRS)

    Jain, I.; Charvat, J. M.; VanBaalen, M.; Lee, L.; Wear, M. L.

    2014-01-01

    In an effort to improve cardiovascular disease (CVD) risk prediction, this analysis evaluates and compares the applicability of multiple CVD risk scores to the NASA Astronaut Corps which is extremely healthy at selection.

  5. The Chinese physicians' CardiovAscular Risk Evaluation (CARE) survey: an assessment of physicians' own cardiovascular risks

    PubMed Central

    Hu, D-Y; Yu, J-M; Chen, F; Sun, Y-H; Jiang, Q-W

    2010-01-01

    Objective To estimate the 10-year risk of cardiovascular disease (CVD)/coronary heart disease (CHD) in physicians using two models (the Chinese and Framingham models). Methods This was a multicentre, cross-sectional survey, which recruited cardiovascular physicians from 386 medical centres in all 31 provinces and municipalities in China. Cardiovascular risk factors such as body mass index, blood pressure and cholesterol were recorded during enrolment. Control rates (%) of hypertension, hypercholesterolaemia and diabetes were defined according to guidelines. Participants aged ≥35 years completed the Framingham model and participants aged ≤59 years completed the Chinese prediction model. Results A total of 820 (41.5%) women and 1598 (78.7%) men had ≥1 markedly raised CVD risk factors. The Chinese prediction model showed that 22 (1.2%) women and 143 (7.6%) men had a 10-year risk of ischaemic CVD ≥5%, and an above-average level of 10-year ischaemic CVD risk factors was found in 20.6% of women and in 54.6% of men. When the Framingham model was used, 268 (13.6%) women and 724 (35.7%) men had a 10-year absolute risk of CHD ≥5%. Hypertension, diabetes and hypercholesterolaemia were only controlled in 58.2%, 46.6% and 38.5% of participants, respectively. Only 30.3% of physicians with a 10-year risk of CHD ≥10% were using aspirin. Conclusions The results show suboptimal awareness in physicians of their own cardiovascular risks, and low use of prophylactic agents. Improvement of physicians' risk factors in will improve their ability to act as role models in the promotion of primary and secondary prevention initiatives. PMID:27325952

  6. Movers and stayers: The geography of residential mobility and CVD hospitalisations in Auckland, New Zealand.

    PubMed

    Exeter, Daniel J; Sabel, Clive E; Hanham, Grant; Lee, Arier C; Wells, Susan

    2015-05-01

    The association between area-level disadvantage and health and social outcomes is unequivocal. However, less is known about the health impact of residential mobility, particularly at intra-urban scales. We used an encrypted National Health Index (eNHI) number to link individual-level data recorded in routine national health databases to construct a cohort of 641,532 participants aged 30+ years to investigate the association between moving and CVD hospitalisations in Auckland, New Zealand. Residential mobility was measured for participants according to changes in the census Meshblock of usual residence, obtained from the Primary Health Organisation (PHO) database for every calendar quarter between 1/1/2006 and 31/12/2012. The NZDep2006 area deprivation score at the start and end of a participant's inclusion in the study was used to measure deprivation mobility. We investigated the relative risk of movers being hospitalised for CVD relative to stayers using multi-variable binomial regression models, controlling for age, gender, deprivation and ethnicity. Considered together, movers were 1.22 (1.19-1.26) times more likely than stayers to be hospitalised for CVD. Using the 5×5 deprivation origin-destination matrix to model a patient's risk of CVD based on upward, downward or sideways deprivation mobility, movers within the least deprived (NZDep2006 Quintile 1) areas were 10% less likely than stayers to be hospitalised for CVD, while movers within the most deprived (NZDep2006 Q5) areas were 45% more likely than stayers to have had their first CVD hospitalisation in 2006-2012 (RR: 1.45 [1.35-1.55]). Participants who moved upward also had higher relative risks of having a CVD event, although their risk was less than those observed for participants experiencing downward deprivation mobility. This research suggests that residential mobility is an important determinant of CVD in Auckland. Further investigation is required to determine the impact moving has on the risk of

  7. The absolute path command

    2012-05-11

    The ap command traveres all symlinks in a given file, directory, or executable name to identify the final absolute path. It can print just the final path, each intermediate link along with the symlink chan, and the permissions and ownership of each directory component in the final path. It has functionality similar to "which", except that it shows the final path instead of the first path. It is also similar to "pwd", but it canmore » provide the absolute path to a relative directory from the current working directory.« less

  8. The absolute path command

    SciTech Connect

    Moody, A.

    2012-05-11

    The ap command traveres all symlinks in a given file, directory, or executable name to identify the final absolute path. It can print just the final path, each intermediate link along with the symlink chan, and the permissions and ownership of each directory component in the final path. It has functionality similar to "which", except that it shows the final path instead of the first path. It is also similar to "pwd", but it can provide the absolute path to a relative directory from the current working directory.

  9. CVD 908, CVD 908-htrA, and CVD 909 live oral typhoid vaccines: a logical progression.

    PubMed

    Tacket, Carol O; Levine, Myron M

    2007-07-15

    Typhoid fever remains an important public health problem in many parts of the world. Despite the availability of oral Ty21a (Vivotif; Berna Biotech) and parenteral Vi polysaccharide vaccine (Typhim Vi; Aventis Pasteur), improved typhoid fever vaccines have been sought. These include a series of vaccine candidates developed at the Center for Vaccine Development, University of Maryland, based on attenuation of Salmonella enterica serovar Typhi by deletions in the aroC, aroD, and htrA genes. These vaccine candidates, designated "CVD 908," "CVD 908-htrA," and "CVD 909," have been developed and tested in volunteers with variable success. This review summarizes the clinical data that directed the logical progression of this vaccine development strategy. PMID:17582563

  10. High prevalence of aspirin resistance in elderly patients with cardiovascular disease (CVD) and hyperhomocysteinaemia.

    PubMed

    Zhang, Huaxin; Chen, Xiuying; Liu, Lin; Fan, Li; Cao, Jian; Li, Xiaoli; Hu, Guoliang; Hu, Yixin; Zhu, Bingpo; Liu, Xianfeng; Gao, Yan; Ma, Cong; Leng, Wenxiu

    2014-01-01

    Although aspirin resistance is well reported in CVD, little is known about aspirin response in elderly patients with hyperhomocysteinaemia. The aim of the present study was to explore the prevalence of aspirin resistance in elderly patients with CVD and hyperhomocysteinaemia. A total of 370 elderly patients with CVD were recruited. The study included 216 patients with hyperhomocysteinaemia and 154 patients with normohomocysteinaemia receiving daily aspirin therapy (≥ 75 mg) over 1 month. The effect of aspirin was assessed using by light transmission aggregometry (LTA). Aspirin resistance was defined as ≥ 20% arachidonic acid induced aggregation according to LTA. Aspirin resistance was defined in 48 (13.0%) of 370 patients. The prevalence of aspirin resistance was higher in hyperhomocysteinaemic patients than normohomocysteinaemic patients (16.7% vs. 7.8%, odds ratio (OR)=2.367; 95% confidence interval (CI)=1.188-4.715, p=0.012). In the multivariate logistic regression analysis, hyperhomocysteinaemia (OR=2.406, 95% CI=1.201-4.820, p=0.013) was a significant risk factor for aspirin resistance. A significant number of CVD patients with hyperhomocysteinemia are resistant to aspirin therapy. Hyperhomocysteinemia is a significant risk factor for aspirin resistance in elderly patients with CVD. PMID:24880196

  11. Dietary flavonoid intakes and CVD incidence in the Framingham Offspring Cohort.

    PubMed

    Jacques, Paul F; Cassidy, Aedin; Rogers, Gail; Peterson, Julia J; Dwyer, Johanna T

    2015-11-14

    This study examines the relationship between long-term intake of six flavonoid classes and incidence of CVD and CHD, using a comprehensive flavonoid database and repeated measures of intake, while accounting for possible confounding by components of a healthy dietary pattern. Flavonoid intakes were assessed using a FFQ among the Framingham Offspring Cohort at baseline and three times during follow-up. Cox proportional hazards regression was used to characterise prospective associations between the natural logarithms of flavonoid intakes and CVD incidence using a time-dependent approach, in which intake data were updated at each examination to represent average intakes from previous examinations. Mean baseline age was 54 years, and 45 % of the population was male. Over an average 14·9 years of follow-up among 2880 participants, there were 518 CVD events and 261 CHD events. After multivariable adjustment, only flavonol intake was significantly associated with lower risk of CVD incidence (hazard ratios (HR) per 2·5-fold flavonol increase=0·86, P trend=0·05). Additional adjustment for total fruit and vegetable intake and overall diet quality attenuated this observation (HR=0·89, P trend=0·20 and HR=0·92, P trend=0·33, respectively). There were no significant associations between flavonoids and CHD incidence after multivariable adjustment. Our findings suggest that the observed association between flavonol intake and CVD risk may be a consequence of better overall diet. However, the strength of this non-significant association was also consistent with relative risks observed in previous meta-analyses, and therefore a modest benefit of flavonol intake on CVD risk cannot be ruled out. PMID:26334117

  12. The relationship between Lp(a) and CVD outcomes: a systematic review.

    PubMed

    Forbes, Carol A; Quek, Ruben G W; Deshpande, Sohan; Worthy, Gill; Wolff, Robert; Stirk, Lisa; Kleijnen, Jos; Gandra, Shravanthi R; Djedjos, Stephen; Wong, Nathan D

    2016-01-01

    Robust associations between lipoprotein(a) [Lp(a)] and CVD outcomes among general populations have been published in previous studies. However, associations in high risk primary prevention and secondary prevention populations are less well defined. In order to investigate this further, a systematic review was performed including prospective studies, which assessed the relationship between Lp(a) and CVD outcomes using multivariable analyses. Additional information was gathered on Lp(a) assays, multivariable modelling and population characteristics. Literature searches from inception up to December 2015 retrieved 2850 records. From these 60 studies were included. Across 39 primary prevention studies in the general population (hazard ratios ranged from 1.16 to 2.97) and seven high risk primary prevention studies (hazard ratios ranged from 1.01 to 3.7), there was evidence of a statistically significant relationship between increased Lp(a) and an increased risk of future CVD. Results in 14 studies of secondary prevention populations were also suggestive of a modest statistically significant relationship (hazard ratios ranged from 0.75 to 3.7).Therefore current evidence would suggest that increased Lp(a) levels are associated with modest increases in the risk of future CVD events in both general and higher risk populations. However, further studies are required to confirm these findings. PMID:27184891

  13. Solution based CVD of main group materials.

    PubMed

    Knapp, Caroline E; Carmalt, Claire J

    2016-02-21

    This critical review focuses on the solution based chemical vapour deposition (CVD) of main group materials with particular emphasis on their current and potential applications. Deposition of thin films of main group materials, such as metal oxides, sulfides and arsenides, have been researched owing to the array of applications which utilise them including solar cells, transparent conducting oxides (TCOs) and window coatings. Solution based CVD processes, such as aerosol-assisted (AA)CVD have been developed due to their scalability and to overcome the requirement of suitably volatile precursors as the technique relies on the solubility rather than volatility of precursors which vastly extends the range of potentially applicable compounds. An introduction into the applications and precursor requirements of main group materials will be presented first followed by a detailed discussion of their deposition reviewed according to this application. The challenges and prospects for further enabling research in terms of emerging main group materials will be discussed. PMID:26446057

  14. Iridium-coated rhenium thrusters by CVD

    NASA Technical Reports Server (NTRS)

    Harding, J. T.; Kazaroff, J. M.; Appel, M. A.

    1989-01-01

    Operation of spacecraft thrusters at increased temperature reduces propellant requirements. Inasmuch as propellant comprises the bulk of a satellite's mass, even a small percentage reduction makes possible a significant enhancement of the mission in terms of increased payload. Because of its excellent high temperature strength, rhenium is often the structural material of choice. It can be fabricated into free-standing shapes by chemical vapor deposition (CVD) onto an expendable mandrel. What rhenium lacks is oxidation resistance, but this can be provided by a coating of iridium, also by CVD. This paper describes the process used by Ultramet to fabricate 22-N (5-lbf) and, more recently, 445-N (100-lbf) Ir/Re thrusters; characterizes the CVD-deposited materials; and summarizes the materials effects of firing these thrusters. Optimal propellant mixture ratios can be employed because the materials withstand an oxidizing environment up to the melting temperature of iridium, 2400 C (4350 F).

  15. Iridium-coated rhenium thrusters by CVD

    NASA Technical Reports Server (NTRS)

    Harding, John T.; Kazaroff, John M.; Appel, Marshall A.

    1988-01-01

    Operation of spacecraft thrusters at increased temperature reduces propellant requirements. Inasmuch as propellant comprises the bulk of a satellite's mass, even a small percentage reduction makes possible a significant enhancement of the mission in terms of increased payload. Because of its excellent high temperature strength, rhenium is often the structural material of choice. It can be fabricated into free-standing shapes by chemical vapor deposition (CVD) onto an expendable mandrel. What rhenium lacks is oxidation resistance, but this can be provided by a coating of iridium, also by CVD. This paper describes the process used by Ultramet to fabricate 22-N (5-lbf) and, more recently, 445-N (100-lbf) Ir/Re thrusters; characterizes the CVD-deposited materials; and summarizes the materials effects of firing these thrusters. Optimal propellant mixture ratios can be employed because the materials withstand an oxidizing environment up to the meltimg temperature of iridium, 2400 C (4350 F).

  16. Reducing Cardiovascular and Cancer Risk: How to Address Global Primary Prevention in Clinical Practice.

    PubMed

    Battistoni, Allegra; Mastromarino, Vittoria; Volpe, Massimo

    2015-06-01

    Emerging evidence suggesting the possibility that interventions able to prevent cardiovascular disease (CVD) may also be effective in the prevention of cancer have recently stimulated great interest in the medical community. In particular, data from both experimental and observational studies have demonstrated that aspirin may play a role in preventing different types of cancer. Although the use of aspirin in the secondary prevention of CVD is well established, aspirin in primary prevention is not systematically recommended because the absolute cardiovascular event reduction is similar to the absolute excess in major bleedings. By adding to its cardiovascular prevention benefits, the potential beneficial effect of aspirin in reducing the incidence of mortality and cancer could tip the balance between risks and benefits of aspirin therapy in primary prevention in favor of the latter and broaden the indication for treatment with aspirin in populations at average risk. Prospective and randomized studies are currently investigating the effect of aspirin in prevention of both cancer and CVD; however, clinical efforts at the individual level to promote the use of aspirin in global (or total) primary prevention already could be made on the basis of a balanced evaluation of the benefit/risk ratio. PMID:25873555

  17. AB006. Erectile dysfunction (ED) as a marker for cardiovascular diseases (CVD)

    PubMed Central

    Torres, Luiz Otavio

    2015-01-01

    In 1973 V. Michal, a vascular surgeon said “Erectile dysfunction (ED) is related to diseases of the vascular bed”. And this makes sense since ED and cardiovascular diseases (CVD) share many risk factors like aging, obesity, inactivity, smoking, depression, dyslipidemia, hypertension, diabetes/insuline resistance. These conditions may lead to an oxidative stress which ultimately can promote vasoconstriction, thrombosis, atherosclerosis and finally ED and CVD. One of the most accepted Idea is that small vessels plug earlier, it means, small arteries when have for example 50% of obstruction will probably have a clinical manifestation before bigger arteries!

  18. Thin CVD Coating Protects Titanium Aluminide Alloys

    NASA Technical Reports Server (NTRS)

    Clark, Ronald; Wallace, Terryl; Cunnington, George; Robinson, John

    1994-01-01

    Feasibility of using very thin CVD coatings to provide both protection against oxidation and surfaces of low catalytic activity for thin metallic heat-shield materials demonstrated. Use of aluminum in compositions increases emittances of coatings and reduces transport of oxygen through coatings to substrates. Coatings light in weight and applied to foil-gauge materials with minimum weight penalties.

  19. Pericardial Fat is Associated with All-Cause Mortality but not Incident CVD: The Rancho Bernardo Study

    PubMed Central

    Larsen, Britta A.; Laughlin, Gail A.; Saad, Sarah D.; Barrett-Connor, Elizabeth; Allison, Matthew A.; Wassel, Christina L.

    2015-01-01

    Objective Pericardial and intra-thoracic fat are associated with prevalent cardiovascular disease (CVD) and CVD risk factors. However, it is unclear if these fat depots predict incident CVD events and/or all-cause mortality. We examined prospective associations between areas of pericardial and intra-thoracic fat and incident CVD and mortality over a 12-year follow-up in a subset of participants without baseline clinical CVD from the Rancho Bernardo Study (RBS). Methods Participants were 343 community-dwelling older adults (mean baseline age=67) who completed a clinic visit in 2001–02, including a computed tomography scan of the chest. Incident CVD and mortality were recorded through January 2013. Results Over a 12.6-year median follow-up, there were 60 incident CVD events and 49 deaths. Pericardial fat was associated with all-cause mortality, such that each standard deviation increment predicted a 34% higher chance of death after adjusting for demographics, lifestyle factors, comorbidities, and visceral fat (95% CI=1.01–1.78). When categorized by tertile, those in the middle tertile of pericardial fat showed no increased risk of mortality, while those in the highest tertile had 2.6 times the risk (95% CI=1.10–5.97) compared to the lowest tertile. There was a marginal association between intra-thoracic fat and mortality (p=0.06). Neither pericardial nor intra-thoracic fat was significantly associated with incident CVD. There were no significant interactions by sex. Conclusions Higher pericardial, but not intra-thoracic, fat was associated with earlier all-cause mortality in older adults over a 12-year follow-up. This association was primarily driven by a higher mortality rate in those in the highest tertile of pericardial fat. PMID:25702617

  20. Microbiota and the nitrogen cycle: Implications in the development and progression of CVD and CKD.

    PubMed

    Briskey, David; Tucker, Patrick S; Johnson, David W; Coombes, Jeff S

    2016-07-01

    Chronic kidney disease (CKD) is associated with an increased risk of death from cardiovascular disease (CVD). One factor involved in CVD development is nitric oxide (NO), which acts as a powerful vasodilator. NO is produced via the nitrogen cycle, through the reduction of nitrate to nitrite with the process mainly occurring in the mouth by commensal microbiota. People with CKD have compromised microbiota (dysbiosis) with an increased abundance of potentially pathogenic and pro-inflammatory bacteria capable of producing uremic toxins that contribute to CKD development and reduce enzymatic NO production. However, to date, few studies have comprehensively documented the gut or saliva microbiota in the CKD population or investigated the role of NO in people with CKD. This review will discuss NO pathways that are linked to the progression of CKD and CVD and therapeutic options for targeting these pathways. PMID:27164294

  1. Electronic Absolute Cartesian Autocollimator

    NASA Technical Reports Server (NTRS)

    Leviton, Douglas B.

    2006-01-01

    An electronic absolute Cartesian autocollimator performs the same basic optical function as does a conventional all-optical or a conventional electronic autocollimator but differs in the nature of its optical target and the manner in which the position of the image of the target is measured. The term absolute in the name of this apparatus reflects the nature of the position measurement, which, unlike in a conventional electronic autocollimator, is based absolutely on the position of the image rather than on an assumed proportionality between the position and the levels of processed analog electronic signals. The term Cartesian in the name of this apparatus reflects the nature of its optical target. Figure 1 depicts the electronic functional blocks of an electronic absolute Cartesian autocollimator along with its basic optical layout, which is the same as that of a conventional autocollimator. Referring first to the optical layout and functions only, this or any autocollimator is used to measure the compound angular deviation of a flat datum mirror with respect to the optical axis of the autocollimator itself. The optical components include an illuminated target, a beam splitter, an objective or collimating lens, and a viewer or detector (described in more detail below) at a viewing plane. The target and the viewing planes are focal planes of the lens. Target light reflected by the datum mirror is imaged on the viewing plane at unit magnification by the collimating lens. If the normal to the datum mirror is parallel to the optical axis of the autocollimator, then the target image is centered on the viewing plane. Any angular deviation of the normal from the optical axis manifests itself as a lateral displacement of the target image from the center. The magnitude of the displacement is proportional to the focal length and to the magnitude (assumed to be small) of the angular deviation. The direction of the displacement is perpendicular to the axis about which the

  2. Cardiovascular Disease Risk Factors among Emerging Adults in College

    ERIC Educational Resources Information Center

    Abshire, Demetrius Alexander

    2014-01-01

    The purpose of this dissertation was to examine factors associated with cardiovascular disease (CVD) risk among emerging adults in college aged 18-25 years. CVD risks that develop during this period often persist into adulthood making it an ideal time to target CVD prevention. The specific aims of this dissertation were to 1) explore perceptions…

  3. ABSOLUTE POLARIMETRY AT RHIC.

    SciTech Connect

    OKADA; BRAVAR, A.; BUNCE, G.; GILL, R.; HUANG, H.; MAKDISI, Y.; NASS, A.; WOOD, J.; ZELENSKI, Z.; ET AL.

    2007-09-10

    Precise and absolute beam polarization measurements are critical for the RHIC spin physics program. Because all experimental spin-dependent results are normalized by beam polarization, the normalization uncertainty contributes directly to final physics uncertainties. We aimed to perform the beam polarization measurement to an accuracy Of {Delta}P{sub beam}/P{sub beam} < 5%. The absolute polarimeter consists of Polarized Atomic Hydrogen Gas Jet Target and left-right pairs of silicon strip detectors and was installed in the RHIC-ring in 2004. This system features proton-proton elastic scattering in the Coulomb nuclear interference (CNI) region. Precise measurements of the analyzing power A{sub N} of this process has allowed us to achieve {Delta}P{sub beam}/P{sub beam} = 4.2% in 2005 for the first long spin-physics run. In this report, we describe the entire set up and performance of the system. The procedure of beam polarization measurement and analysis results from 2004-2005 are described. Physics topics of AN in the CNI region (four-momentum transfer squared 0.001 < -t < 0.032 (GeV/c){sup 2}) are also discussed. We point out the current issues and expected optimum accuracy in 2006 and the future.

  4. CVD-Enabled Graphene Manufacture and Technology.

    PubMed

    Hofmann, Stephan; Braeuninger-Weimer, Philipp; Weatherup, Robert S

    2015-07-16

    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

  5. 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

  6. Picosecond photoconductivity of natural and CVD diamonds

    NASA Astrophysics Data System (ADS)

    Garnov, Serge V.; Pimenov, Sergej M.; Ralchenko, Victor G.; Klimentov, Sergei M.; Konov, Vitali I.; Korotoushenko, K. G.; Obraztsova, E. D.; Plotnikova, S. P.; Sagatelyan, D. M.; Holly, Sandor

    1995-07-01

    Photoexcitation and recombination of nonequilibrium charge carriers in both natural gemstone diamonds and CVD (chemical vapor deposition) polycrystalline diamond films in UV spectrum regions have been investigated. Transient picosecond photoconductivity technique applied permitted to conduct measurements with the time resolution better than 200 picoseconds and to register a charge carrier concentration value as low as 1020 - 1013 cm-3. The dependencies of photocurrent amplitude as a function of incident laser radiation intensity in the range from 103 to 1010 W/cm2 have been obtained. Charge carrier lifetimes had been measured and charge carrier drift mobility were estimated. It is shown that the electronic properties of high quality thick CVD diamond films are comparable to those of the most perfect natural type IIa crystals. Investigation of Raman and luminescence spectra of diamonds have been performed along with scanning electron microscopy studies to characterize bulk and surface structure of tested specimens.

  7. Scrolling of Suspended CVD Graphene Sheets

    NASA Astrophysics Data System (ADS)

    Martynov, Oleg; Yeom, Sinchul; Bockrath, Marc; UC: Riverside Team

    Carbon Nanoscrolls, one dimensional spiral forms of graphitic carbon, have attracted recent interest due to their novel proposed properties. Although various production methods and studies of carbon nanoscrolls have been performed, low yield and poor controllability of their synthesis have slowed progress in this field. Suspended graphene membranes and carbon nanotubes have been predicted as promising systems for the formation of graphene scrolls. We have suspended chemical vapor deposition (CVD)-grown graphene over large holes in a Si/SiO2 substrate to make suspended membranes upon which nanotubes are placed. Initial experiments have been performed showing that tears or cuts of the suspended sheet can initiate scrolling. Our latest progress towards carbon nanotube initiated formation of graphene scrolls and suspended CVD graphene scrolling, along with measurements of these novel structures will be presented.

  8. Implants as absolute anchorage.

    PubMed

    Rungcharassaeng, Kitichai; Kan, Joseph Y K; Caruso, Joseph M

    2005-11-01

    Anchorage control is essential for successful orthodontic treatment. Each tooth has its own anchorage potential as well as propensity to move when force is applied. When teeth are used as anchorage, the untoward movements of the anchoring units may result in the prolonged treatment time, and unpredictable or less-than-ideal outcome. To maximize tooth-related anchorage, techniques such as differential torque, placing roots into the cortex of the bone, the use of various intraoral devices and/or extraoral appliances have been implemented. Implants, as they are in direct contact with bone, do not possess a periodontal ligament. As a result, they do not move when orthodontic/orthopedic force is applied, and therefore can be used as "absolute anchorage." This article describes different types of implants that have been used as orthodontic anchorage. Their clinical applications and limitations are also discussed. PMID:16463910

  9. Absolute Equilibrium Entropy

    NASA Technical Reports Server (NTRS)

    Shebalin, John V.

    1997-01-01

    The entropy associated with absolute equilibrium ensemble theories of ideal, homogeneous, fluid and magneto-fluid turbulence is discussed and the three-dimensional fluid case is examined in detail. A sigma-function is defined, whose minimum value with respect to global parameters is the entropy. A comparison is made between the use of global functions sigma and phase functions H (associated with the development of various H-theorems of ideal turbulence). It is shown that the two approaches are complimentary though conceptually different: H-theorems show that an isolated system tends to equilibrium while sigma-functions allow the demonstration that entropy never decreases when two previously isolated systems are combined. This provides a more complete picture of entropy in the statistical mechanics of ideal fluids.

  10. The relationship between calcium intake, obesity, and cardiovascular disease risk factors: the jackson heart study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cardiovascular disease (CVD) is a major health risk in the United States. Major indicators of CVD risk include obesity, blood lipids, and blood pressure. Modifiable risk factors associated with CVD include body composition (body mass index and waist circumference), serum lipids, and blood pressure. ...

  11. Worldwide Exposures to Cardiovascular Risk Factors and Associated Health Effects: Current Knowledge and Data Gaps.

    PubMed

    Tzoulaki, Ioanna; Elliott, Paul; Kontis, Vasilis; Ezzati, Majid

    2016-06-01

    Information on exposure to, and health effects of, cardiovascular disease (CVD) risk factors is needed to develop effective strategies to prevent CVD events and deaths. Here, we provide an overview of the data and evidence on worldwide exposures to CVD risk factors and the associated health effects. Global comparative risk assessment studies have estimated that hundreds of thousands or millions of CVD deaths are attributable to established CVD risk factors (high blood pressure and serum cholesterol, smoking, and high blood glucose), high body mass index, harmful alcohol use, some dietary and environmental exposures, and physical inactivity. The established risk factors plus body mass index are collectively responsible for ≈9.7 million annual CVD deaths, with high blood pressure accounting for more CVD deaths than any other risk factor. Age-standardized CVD death rates attributable to established risk factors plus high body mass index are lowest in high-income countries, followed by Latin America and the Caribbean; they are highest in the region of central and eastern Europe and central Asia. However, estimates of the health effects of CVD risk factors are highly uncertain because there are insufficient population-based data on exposure to most CVD risk factors and because the magnitudes of their effects on CVDs in observational studies are likely to be biased. We identify directions for research and surveillance to better estimate the effects of CVD risk factors and policy options for reducing CVD burden by modifying preventable risk factors. PMID:27267538

  12. NHS health checks through general practice: randomised trial of population cardiovascular risk reduction

    PubMed Central

    2012-01-01

    . Conclusions The NHS Health Check service in Stoke on Trent resulted in significant reduction in estimated population CVD risk. There was no evidence of further benefit of the additional lifestyle support services in terms of absolute CVD risk reduction. PMID:23116213

  13. Absolute neutrino mass measurements

    NASA Astrophysics Data System (ADS)

    Wolf, Joachim

    2011-10-01

    The neutrino mass plays an important role in particle physics, astrophysics and cosmology. In recent years the detection of neutrino flavour oscillations proved that neutrinos carry mass. However, oscillation experiments are only sensitive to the mass-squared difference of the mass eigenvalues. In contrast to cosmological observations and neutrino-less double beta decay (0v2β) searches, single β-decay experiments provide a direct, model-independent way to determine the absolute neutrino mass by measuring the energy spectrum of decay electrons at the endpoint region with high accuracy. Currently the best kinematic upper limits on the neutrino mass of 2.2eV have been set by two experiments in Mainz and Troitsk, using tritium as beta emitter. The next generation tritium β-experiment KATRIN is currently under construction in Karlsruhe/Germany by an international collaboration. KATRIN intends to improve the sensitivity by one order of magnitude to 0.2eV. The investigation of a second isotope (137Rh) is being pursued by the international MARE collaboration using micro-calorimeters to measure the beta spectrum. The technology needed to reach 0.2eV sensitivity is still in the R&D phase. This paper reviews the present status of neutrino-mass measurements with cosmological data, 0v2β decay and single β-decay.

  14. Absolute neutrino mass measurements

    SciTech Connect

    Wolf, Joachim

    2011-10-06

    The neutrino mass plays an important role in particle physics, astrophysics and cosmology. In recent years the detection of neutrino flavour oscillations proved that neutrinos carry mass. However, oscillation experiments are only sensitive to the mass-squared difference of the mass eigenvalues. In contrast to cosmological observations and neutrino-less double beta decay (0v2{beta}) searches, single {beta}-decay experiments provide a direct, model-independent way to determine the absolute neutrino mass by measuring the energy spectrum of decay electrons at the endpoint region with high accuracy.Currently the best kinematic upper limits on the neutrino mass of 2.2eV have been set by two experiments in Mainz and Troitsk, using tritium as beta emitter. The next generation tritium {beta}-experiment KATRIN is currently under construction in Karlsruhe/Germany by an international collaboration. KATRIN intends to improve the sensitivity by one order of magnitude to 0.2eV. The investigation of a second isotope ({sup 137}Rh) is being pursued by the international MARE collaboration using micro-calorimeters to measure the beta spectrum. The technology needed to reach 0.2eV sensitivity is still in the R and D phase. This paper reviews the present status of neutrino-mass measurements with cosmological data, 0v2{beta} decay and single {beta}-decay.

  15. 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

  16. Role of sulodexide in the treatment of CVD.

    PubMed

    Andreozzi, G M

    2014-06-01

    Treatment of vascular diseases should be based on established pathophysiological concepts, and this also applies to chronic venous disease (CVD). On the basis of the latest research in this field, this paper summarizes the most advanced pathophysiological knowledge regarding the hemodynamics of the large veins and of the microcirculation, the endothelial function and inflammation, and the use of sulodexide in the treatment of CVD. The emerging theories on the pathophysiology of CVD consider inflammation, endothelial glycocalyx dysfunction, and the consequent changes in the extracellular matrix to play key roles in the development of CVD, and support a renewed interest in the research and application of sulodexide. As part of active approach to the treatment of CVD including edema and trophic venous alterations, sulodexide could help to alleviate progressive signs and symptoms of disease in any clinical CEAP class of CVD, from C1 to C6. PMID:24936534

  17. CVD diamond as an optical material for adverse environments

    NASA Astrophysics Data System (ADS)

    Snail, Keith A.

    A status report is presented on the obstacles and current research related to using CVD diamond as an optical material. Problems discussed include properties of CVD carbon deposits, including structure, thermal conductivity and oxidation resistance, which are relevant to the optical uses of diamond; absorption coefficient measurements on CVD diamond in the visible and IR; and a review of various aspects of the synthesis of CVD diamond, including the growth of transparent and translucent diamond, efforts to grow diamond at low substrate temperatures, and approches to reducing the optical scatter of as grown polycrystalline diamond films and windows. Particular attention is given to techniques for reducing optical scatter which involve modifying materials morphologies during the growth process by controlling nucleation density, renucleaton frequency, and/or the orientation of crystal faces at film surfaces; techniques for postdeposition polishing of the surface of CVD diamond films and windows; and optical applications for CVD diamond.

  18. CVD diamond as an optical material for adverse environments

    NASA Astrophysics Data System (ADS)

    Snail, Keith A.

    1991-01-01

    A status report is presented on the obstacles and current research related to using CVD diamond as an optical material. Problems discussed include properties of CVD carbon deposits, including structure, thermal conductivity and oxidation resistance, which are relevant to the optical uses of diamond; absorption coefficient measurements on CVD diamond in the visible and IR; and a review of various aspects of the synthesis of CVD diamond, including the growth of transparent and translucent diamond, efforts to grow diamond at low substrate temperatures, and approches to reducing the optical scatter of as grown polycrystalline diamond films and windows. Particular attention is given to techniques for reducing optical scatter which involve modifying materials morphologies during the growth process by controlling nucleation density, renucleaton frequency, and/or the orientation of crystal faces at film surfaces; techniques for postdeposition polishing of the surface of CVD diamond films and windows; and optical applications for CVD diamond.

  19. Modeling for CVD of Solid Oxide Electrolyte

    SciTech Connect

    Starr, T.L.

    2002-09-18

    Because of its low thermal conductivity, high thermal expansion and high oxygen ion conductivity yttria-stabilized zirconia (YSZ) is the material of choice for high temperature electrolyte applications. Current coating fabrication methods have their drawbacks, however. Air plasma spray (APS) is a relatively low-cost process and is suitable for large and relatively complex shapes. it is difficult to produce uniform, relatively thin coatings with this process, however, and the coatings do not exhibit the columnar microstructure that is needed for reliable, long-term performance. The electron-beam physical vapor deposition (EB-PVD) process does produce the desirable microstructure, however, the capital cost of these systems is very high and the line-of-sight nature of the process limits coating uniformity and the ability to coat large and complex shapes. The chemical vapor deposition (CVD) process also produces the desirable columnar microstructure and--under proper conditions--can produce uniform coatings over complex shapes. CVD has been used for many materials but is relatively undeveloped for oxides, in general, and for zirconia, in particular. The overall goal of this project--a joint effort of the University of Louisville and Oak Ridge National Laboratory (ORNL)--is to develop the YSZ CVD process for high temperature electrolyte applications. This report describes the modeling effort at the University of Louisville, which supports the experimental work at ORNL. Early work on CVD of zirconia and yttria used metal chlorides, which react with water vapor to form solid oxide. Because of this rapid gas-phase reaction the water generally is formed in-situ using the reverse water-gas-shift reaction or a microwave plasma. Even with these arrangements gas-phase nucleation and powder formation are problems when using these precursors. Recent efforts on CVD of zirconia and YSZ have focused on use of metal-organic precursors (MOCVD). These are more stable in the gas

  20. Vitamin B6: a challenging link between nutrition and inflammation in CVD.

    PubMed

    Lotto, Valentina; Choi, Sang-Woon; Friso, Simonetta

    2011-07-01

    The objective of the present review is to highlight the relationship between low vitamin B6 status and CVD through its link with inflammation. While overt vitamin B6 deficiency is uncommon in clinical practice, increasing evidence suggests that marginal vitamin B6 deficiency is rather frequent in a consistent proportion of the population and is related to an increased risk of inflammation-related diseases. Ample evidence substantiates the theory of atherosclerosis as an inflammatory disease, and low plasma vitamin B6 concentrations have been related to increased CVD risk. Several studies have also shown that low vitamin B6 status is associated with rheumatoid arthritis and chronic inflammatory bowel diseases, both of which hold an underlying chronic inflammatory condition. Furthermore, the inverse association observed between inflammation markers and vitamin B6 supports the notion that inflammation may represent the common link between low vitamin B6 status and CVD risk. In addition to the epidemiological evidence, there are a number of cell culture and animal studies that have suggested several possible mechanisms relating impaired vitamin B6 status with chronic inflammation. A mild vitamin B6 deficiency characterises, in most cases, a subclinical at-risk condition in inflammatory-linked diseases which should be addressed by an appropriate individually tailored nutritional preventive or therapeutic strategy. PMID:21486513

  1. Antioxidant Status before and after Dietary Intervention in Cardiovascular Disease (CVD) Patients.

    PubMed

    Karajibani, M; Hashemi, M; Montazerifar, F; Dikshit, M

    2010-12-01

    There is some evidence showing an inverse correlation between dietary sources including natural antioxidant vitamins and the risk of cardiovascular disease (CVD). The aim of this study was to evaluate the effect of dietary antioxidants on oxidative stress in CVD patients. This study was carried out on 31 CVD patients and 63 healthy individuals. Nutritional status and dietary antioxidant vitamins were assessed by 48-hour recall. Superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities as well as the levels of vitamins A, E, C, total antioxidant capacity (TAC) and malondialdehyde (MDA) were determined before and after serving fresh fruits and vegetables for 3 months. Before intervention intake, levels of vitamins A, E and C were significantly lower in patients than in normal individuals (P<0.001). The serum levels of vitamins A, E and C were significantly lower in the cases than in the control subjects. After intervention, the serum levels of vitamins A, E and C were increased significantly (P<0.0001). Similarly, the levels of TAC as well as the activities of SOD and GPx were found to increase by end of 3 months. In addition, a significant increase of TAC and a decrease in MDA levels were observed. In conclusion, the findings show that dietary supplementation improves the antioxidant defense system in CVD patients. PMID:22691986

  2. 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.

  3. Absolute Identification by Relative Judgment

    ERIC Educational Resources Information Center

    Stewart, Neil; Brown, Gordon D. A.; Chater, Nick

    2005-01-01

    In unidimensional absolute identification tasks, participants identify stimuli that vary along a single dimension. Performance is surprisingly poor compared with discrimination of the same stimuli. Existing models assume that identification is achieved using long-term representations of absolute magnitudes. The authors propose an alternative…

  4. Be Resolute about Absolute Value

    ERIC Educational Resources Information Center

    Kidd, Margaret L.

    2007-01-01

    This article explores how conceptualization of absolute value can start long before it is introduced. The manner in which absolute value is introduced to students in middle school has far-reaching consequences for their future mathematical understanding. It begins to lay the foundation for students' understanding of algebra, which can change…

  5. CVD growth of graphene at low temperature

    NASA Astrophysics Data System (ADS)

    Zeng, Changgan

    2012-02-01

    Graphene has attracted a lot of research interest owing to its exotic properties and a wide spectrum of potential applications. Chemical vapor deposition (CVD) from gaseous hydrocarbon sources has shown great promises for large-scale graphene growth. However, high growth temperature, typically 1000^oC, is required for such growth. In this talk, I will show a revised CVD route to grow graphene on Cu foils at low temperature, adopting solid and liquid hydrocarbon feedstocks. For solid PMMA and polystyrene precursors, centimeter-scale monolayer graphene films are synthesized at a growth temperature down to 400^oC. When benzene is used as the hydrocarbon source, monolayer graphene flakes with excellent quality are achieved at a growth temperature as low as 300^oC. I will also talk about our recent progress on low-temperature graphene growth using paraterphenyl as precursor. The successful low-temperature growth can be qualitatively understood from the first principles calculations. Our work might pave a way to economical and convenient growth route of graphene, as well as better control of the growth pattern of graphene at low temperature.

  6. Comparative evaluation of CVD diamond technologies

    SciTech Connect

    Anthony, T.R.

    1993-01-01

    Chemical vapor deposition (CVD) of diamonds occurs from hydrogen-hydrocarbon gas mixtures in the presence of atomic hydrogen at subatmospheric pressures. Most CVD methods are based on different means of generating and transporting atomic hydrogen in a particular system. Evaluation of these different techniques involves their capital costs, material costs, energy costs, labor costs and the type and quality of diamond that they produce. Currently, there is no universal agreement on which is the best technique and technique selection has been largely driven by the professional background of the user as well as the particular application of interest. This article discusses the criteria for evaluating a process for low-pressure deposition of diamond. Next, a brief history of low-pressure diamond synthesis is reviewed. Several specific processes are addressed, including the hot filament process, hot filament electron-assisted chemical vapor deposition, and plasma generation of atomic hydrogen by glow discharge, microwave discharge, low pressure radio frequency discharge, high pressure DC discharge, high pressure microwave discharge jets, high pressure RF discharge, and high and low pressure flames. Other types of diamond deposition methods are also evaluated. 101 refs., 15 figs.

  7. CVD boron on calcium chromate powder

    SciTech Connect

    Coonen, R.M.

    1984-09-01

    This study was an experimental effort to improve the compositional homogeneity of a pyrotechnic mixture of boron and calcium chromate (CaCrO/sub 4/). Boron was deposited onto calcium chromate powders at 350/sup 0/C from a diborane and hydrogen gas mixture at a pressure of 40 torr by Chemical Vapor Deposition (CVD). The B:CaCrO/sub 4/ ratio of the coated powders was analyzed by inductively-coupled plasma spectroscopy and the distribution of the two phases was observed by electron microprobe analysis. The pyrotechnic activity was determined by differential thermal analysis. In addition to varying the composition of the mixture, an attempt was made to vary the boron distribution by coating both sized and unsized CaCrO/sub 4/ powders. Boron was deposited for 2 h onto sized CaCrO/sub 4/ powder, which resulted in a higher weight percentage of boron in comparison to the unsized powder. CVD coated CaCrO/sub 4/ powders began their pyrotechnic activity at an auto ignition temperature that was lower than the auto ignition temperature observed for mechanically blended mixtures. The coating of sized CaCrO/sub 4/ powder improved the uniformity of boron deposition of CaCrO/sub 4/, but it also decreased the pyrotechnic activity.

  8. Synthesis of Carbon Nanotubes Array by CVD

    NASA Technical Reports Server (NTRS)

    Zhu, S.; Su, C.; Cochrane, J. C.; Lehoczky, S. L.; Muntele, I.; Ila, D.; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    Since the properties of multi-wall carbon nanotubes (MWCNT) are superior in many devices such as electronics and sensors, many efforts have been involved in synthesizing particular structural or dimensional MWCNT. Uniform aligned MWCNT array is one of the prototype structures for devices such as filed emission device and microelectromechanical systems in which a large length to diameter ratio may also be required. Most aligned MWCNT recently synthesized by plasma enhanced chemical vapor deposition (CVD) have cone shaped structures. This presentation will illustrate aligned MWCNT array synthesized on silicon substrates using thermal CVD that could produce MWCNT with uniform diameter. An array of nickel particles was used as catalyst for MWCNT growth. A thin Ti or Au buffer layer was coated on the substrate prior to depositing nickel particles. Because the MWCNT size depends on the catalyst particle size, the nickel particle size annealed at various temperatures was investigated. MWCNT were grown on the substrate in the temperature range of 700 C - 1000 C and the pressure range of 1 to 300 torr. Methane and hydrogen gases with methane content of 1 - 10 % were used for the MWCNT synthesis. Morphology, length and diameter of MWCNT were determined by scanning electron microscopy and Raman spectroscopy. The detailed results of synthesis and characterizations will be discussed in the presentation.

  9. 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.

  10. Cardiovascular disease risk in young people with type 1 diabetes.

    PubMed

    Snell-Bergeon, Janet K; Nadeau, Kristen

    2012-08-01

    Cardiovascular disease (CVD) is the most frequent cause of death in people with type 1 diabetes (T1D), despite modern advances in glycemic control and CVD risk factor modification. CVD risk identification is essential in this high-risk population, yet remains poorly understood. This review discusses the risk factors for CVD in young people with T1D, including hyperglycemia, traditional CVD risk factors (dyslipidemia, smoking, physical activity, hypertension), as well as novel risk factors such as insulin resistance, inflammation, and hypoglycemia. We present evidence that adverse changes in cardiovascular function, arterial compliance, and atherosclerosis are present even during adolescence in people with T1D, highlighting the need for earlier intervention. The methods for investigating cardiovascular risk are discussed and reviewed. Finally, we discuss the observational studies and clinical trials which have thus far attempted to elucidate the best targets for early intervention in order to reduce the burden of CVD in people with T1D. PMID:22528676

  11. Why simulations of colour for CVD observers might not be what they seem

    NASA Astrophysics Data System (ADS)

    Green, Phil

    2015-01-01

    A common task in universal design is to create a 'simulation' of the appearance of a colour image as it appears to a CVD observer. Although such simulations are useful in illustrating the particular problems that a CVD observer has in discriminating between colours in an image, it may not be reasonable to assume that such a simulation accurately conveys the experience of the CVD observer to an observer with normal vision. Two problems with this assumption are discussed here. First, it risks confusing appearance with sensation. A colour appearance model can more or less accurately predict the change in appearance of a colour when it is viewed under different conditions, but does not define the actual sensation. Such a sensation cannot be directly communicated but merely located on a scale with other related sensations. In practice we avoid this epistemological problem by asking observers to judge colour matches, relations and differences, none of which requires examination of the sensation itself. Since we do not truly know what sensation a normal observer experiences, it seems unscientific to suppose that we can do so for CVD observers. Secondly, and following from the above, the relation between stimulus and corresponding sensation is established as part of neural development during infancy, and while we can determine the stimulus we cannot readily determine what sensation the stimulus is mapped to, or what the available range of sensations is for a given observer. It is suggested that a similar range of sensations could be available to CVD observers as to normal observers.

  12. Cold Vacuum Drying (CVD) Set Point Determination

    SciTech Connect

    PHILIPP, B.L.

    2000-01-12

    This document provides the calculations used to determine the error of safety class signals used for the CVD process These errors are used with the Parameter limits to arrive at the initial set point. The Safety Class Instrumentation and Control (SCIC) system provides active detection and response to process anomalies that, if unmitigated would result in a safety event. Specifically actuation of the SCIC system includes two portions. The portion which isolates the MCO and initiates the safety-class helium (SCHe) purge, and the portion which detects and stops excessive heat input to the MCO on high tempered water MCO inlet temperature. For the MCO isolation and purge the SCIC receives signals from MCO pressure (both positive pressure and vacuum) helium flow rate, bay high temperature switches, seismic trips and time under vacuum trips.

  13. High-temperature oxidation of CVD silicon-based ceramics

    SciTech Connect

    Goto, Takashi; Hirai, Toshio; Iguchi, Yasutaka

    1996-12-31

    Oxidation behavior of CVD SiC and CVD Si{sub 3}N{sub 4} was studied at 1773 to 2023 K in Ar-O{sub 2}, N{sub 2}-O{sub 2} and CO-CO{sub 2} atmospheres. In Ar-O{sub 2} and N{sub 2}-O{sub 2} atmospheres, the active oxidation rates for CVD SiC and CVD Si{sub 3}N{sub 4} were dominated by oxygen diffusion through a gas boundary layer. The active-to-passive transition oxygen partial pressures for CVD SiC were slightly greater than those for CVD Si{sub 3}N{sub 4}. In CO-CO{sub 2} atmospheres, at PCO{sub 2}/PCO < 10{sup -3} inward diffusion of CO{sub 2} gas controlled the active oxidation rates for CVD SiC; however, a chemical reaction controlled the rates for CVD Si{sub 3}N{sub 4}. At PCO{sub 2}/PCO > 10 {sup -2}, SiO{sub 2} particles or layers formed during the active oxidation; the decomposition of SiO{sub 2} could control the active oxidation rates. The Wagner model can be used to explain the active-to-passive transition in these atmospheres for both CVD SiC and CVD Si{sub 3}N{sub 4}. The volatility diagram and thermodynamic calculation, including mass balance relationship, were also useful to understand the transition behavior.

  14. Nanoelectronic biosensors based on CVD grown graphene

    NASA Astrophysics Data System (ADS)

    Huang, Yinxi; Dong, Xiaochen; Shi, Yumeng; Li, Chang Ming; Li, Lain-Jong; Chen, Peng

    2010-08-01

    Graphene, a single-atom-thick and two-dimensional carbon material, has attracted great attention recently. Because of its unique electrical, physical, and optical properties, graphene has great potential to be a novel alternative to carbon nanotubes in biosensing. We demonstrate the use of large-sized CVD grown graphene films configured as field-effect transistors for real-time biomolecular sensing. Glucose or glutamate molecules were detected by the conductance change of the graphene transistor as the molecules are oxidized by the specific redox enzyme (glucose oxidase or glutamic dehydrogenase) functionalized onto the graphene film. This study indicates that graphene is a promising candidate for the development of real-time nanoelectronic biosensors.Graphene, a single-atom-thick and two-dimensional carbon material, has attracted great attention recently. Because of its unique electrical, physical, and optical properties, graphene has great potential to be a novel alternative to carbon nanotubes in biosensing. We demonstrate the use of large-sized CVD grown graphene films configured as field-effect transistors for real-time biomolecular sensing. Glucose or glutamate molecules were detected by the conductance change of the graphene transistor as the molecules are oxidized by the specific redox enzyme (glucose oxidase or glutamic dehydrogenase) functionalized onto the graphene film. This study indicates that graphene is a promising candidate for the development of real-time nanoelectronic biosensors. Electronic supplementary information (ESI) available: AFM images of graphene film before and after functionalization, transfer curves of graphene after every step, SEM image of CNT-net, and detection results using CNT-net devices. See DOI: 10.1039/c0nr00142b

  15. Perceptions of risk: understanding cardiovascular disease

    PubMed Central

    Webster, Ruth; Heeley, Emma

    2010-01-01

    Cardiovascular disease (CVD) is still the leading cause of death and disability worldwide despite the availability of well-established and effective preventive options. Accurate perception of a patient’s risk by both the patient and the doctors is important as this is one of the components that determine health-related behavior. Doctors tend to not use cardiovascular (CV) risk calculators and underestimate the absolute CV risk of their patients. Patients show optimistic bias when considering their own risk and consistently underestimate it. Poor patient health literacy and numeracy must be considered when thinking about this problem. Patients must possess a reasonably high level of understanding of numerical processes when doctors discuss risk, a level that is not possessed by large numbers of the population. In order to overcome this barrier, doctors need to utilize various tools including the appropriate use of visual aids to accurately communicate risk with their patients. Any intervention has been shown to be better than nothing in improving health understanding. The simple process of repeatedly conveying risk information to a patient has been shown to improve accuracy of risk perception. Doctors need to take responsibility for the accurate assessment and effective communication of CV risk in their patients in order to improve patient uptake of cardioprotective lifestyle choices and preventive medications. PMID:22312218

  16. Population Specific and Up to Date Cardiovascular Risk Charts Can Be Efficiently Obtained with Record Linkage of Routine and Observational Data

    PubMed Central

    Faeh, David; Braun, Julia; Rufibach, Kaspar; Puhan, Milo A.; Marques-Vidal, Pedro; Bopp, Matthias

    2013-01-01

    Background Only few countries have cohorts enabling specific and up-to-date cardiovascular disease (CVD) risk estimation. Individual risk assessment based on study samples that differ too much from the target population could jeopardize the benefit of risk charts in general practice. Our aim was to provide up-to-date and valid CVD risk estimation for a Swiss population using a novel record linkage approach. Methods Anonymous record linkage was used to follow-up (for mortality, until 2008) 9,853 men and women aged 25–74 years who participated in the Swiss MONICA (MONItoring of trends and determinants in CVD) study of 1983–92. The linkage success was 97.8%, loss to follow-up 1990–2000 was 4.7%. Based on the ESC SCORE methodology (Weibull regression), we used age, sex, blood pressure, smoking, and cholesterol to generate three models. We compared the 1) original SCORE model with a 2) recalibrated and a 3) new model using the Brier score (BS) and cross-validation. Results Based on the cross-validated BS, the new model (BS = 14107×10−6) was somewhat more appropriate for risk estimation than the original (BS = 14190×10−6) and the recalibrated (BS = 14172×10−6) model. Particularly at younger age, derived absolute risks were consistently lower than those from the original and the recalibrated model which was mainly due to a smaller impact of total cholesterol. Conclusion Using record linkage of observational and routine data is an efficient procedure to obtain valid and up-to-date CVD risk estimates for a specific population. PMID:23457516

  17. Shared Genetic Aetiology between Cognitive Ability and Cardiovascular Disease Risk Factors: Generation Scotland's Scottish Family Health Study

    ERIC Educational Resources Information Center

    Luciano, Michelle; Batty, G. David; McGilchrist, Mark; Linksted, Pamela; Fitzpatrick, Bridie; Jackson, Cathy; Pattie, Alison; Dominiczak, Anna F.; Morris, Andrew D.; Smith, Blair H.; Porteous, David; Deary, Ian J.

    2010-01-01

    People with higher general cognitive ability in early life have more favourable levels of cardiovascular disease (CVD) risk factors in adulthood and CVD itself. The mechanism of these associations is not known. Here we examine whether general cognitive ability and CVD risk factors share genetic and/or environmental aetiology. In this large,…

  18. Alcohol Consumption and Risk of Cardiovascular Disease and Mortality in Women: Potential Mediating Mechanisms

    PubMed Central

    Djoussé, Luc; Lee, I-Min; Buring, Julie E; Gaziano, J. Michael

    2009-01-01

    Background: Although an association between moderate alcohol consumption and decreased cardiovascular disease (CVD) and mortality has been reported, limited data are available on potential mediating mechanisms. We examined the association between alcohol and CVD and mortality in 26,399 women and estimated the proportion of reduced risk of CVD/mortality explained by a series of intermediate factors. Methods and Results: Alcohol consumption was self-reported at baseline and CVD events and deaths were ascertained via follow-up questionnaires and medical records. Baseline levels of hemoglobin A1c, inflammatory markers, hemostatic factors, and lipids were measured. Blood pressure and hypercholesterolemia; and treatment for lipids were self-reported. During a mean follow up of 12.2 years, 1039 CVD events, 785 deaths (153 CVD deaths) occurred. There was a J-shaped relation between alcohol consumption and incident CVD, total and CVD mortality in a multivariable model. Compared with abstainers, alcohol intake of 5-14.9 g/d was associated with 26%, 35%, and 51% lower risk of CVD, total and CVD mortality, respectively, in a multivariable model. For CVD risk reduction, lipids made the largest contribution to the lower risk of CVD (28.7%), followed by hemoglobin A1c/diabetes (25.3%), inflammatory/hemostatic factors (5%), and blood pressure factors (4.6%). All these mediating factors together explained 86.3%, 18.7%, and 21.8% of the observed lower risk of CVD, total and CVD mortality, respectively. Conclusions: These data suggest that alcohol effects on lipids and insulin sensitivity may account for a large proportion of the lower risk of CVD/mortality observed with moderate drinking under the assumption that the alcohol-CVD association is causal. PMID:19597054

  19. How Gene Networks Can Uncover Novel CVD Players

    PubMed Central

    Parnell, Laurence D; Casas-Agustench, Patricia; Iyer, Lakshmanan K; Ordovas, Jose M

    2014-01-01

    Cardiovascular diseases (CVD) are complex, involving numerous biological entities from genes and small molecules to organ function. Placing these entities in networks where the functional relationships among the constituents are drawn can aid in our understanding of disease onset, progression and prevention. While networks, or interactomes, are often classified by a general term, say lipids or inflammation, it is a more encompassing class of network that is more informative in showing connections among the active entities and allowing better hypotheses of novel CVD players to be formulated. A range of networks will be presented whereby the potential to bring new objects into the CVD milieu will be exemplified. PMID:24683432

  20. How Gene Networks Can Uncover Novel CVD Players.

    PubMed

    Parnell, Laurence D; Casas-Agustench, Patricia; Iyer, Lakshmanan K; Ordovas, Jose M

    2014-01-01

    Cardiovascular diseases (CVD) are complex, involving numerous biological entities from genes and small molecules to organ function. Placing these entities in networks where the functional relationships among the constituents are drawn can aid in our understanding of disease onset, progression and prevention. While networks, or interactomes, are often classified by a general term, say lipids or inflammation, it is a more encompassing class of network that is more informative in showing connections among the active entities and allowing better hypotheses of novel CVD players to be formulated. A range of networks will be presented whereby the potential to bring new objects into the CVD milieu will be exemplified. PMID:24683432

  1. Chiral electron transport in CVD bilayer graphene

    NASA Astrophysics Data System (ADS)

    Lee, Kyunghoon; Eo, Yun Suk; Kurdak, Cagliyan; Zhong, Zhaohui

    2014-03-01

    Charge carriers in bilayer graphene have a parabolic energy spectrum. Due to this band structure they are massive quasiparticles having a finite density of state at zero energy like other non-relativistic charge carriers in conventional two dimensional materials. However, they are massive Dirac fermions which have a chiral nature similar to the case of massless Dirac fermions in single layer graphene. Coupling of pseudospin and motion of charge carrier via chirality can result in dramatic consequence for transport in bipolar regime like Klein tunneling, Fabry-Perot interference, collimation of charge carrier, Veslago lens, etc. However, little attention has been paid to chiral dependent electron transport in bilayer graphene. Here we study these properties by probing phase coherent transport behavior in CVD bilayer graphene devices with sub-200nm channel length. Complex Fabry-Perot interference patterns are observed in resonant cavities defined by local gating. By applying Fourier analysis technique, we successfully analyze and identify the origin of each individual interference pattern in bipolar and monopolar regime. Our initial results also hint at the observation of cloaking of electronic states against chiral electrons in bilayer graphene.

  2. Photo-electronic properties of CVD amorphous silicon

    NASA Astrophysics Data System (ADS)

    Salau, Akinola Muritala

    1983-12-01

    D.c. conductivity, thermoelectric power and photoconductivity of amorphous silicon films prepared by chemical vapor deposition (CVD) have been measured as functions of operating and annealing temperatures. Several interpretations of the results obtained have been suggested.

  3. CVD facility electrical system captor/dapper study

    SciTech Connect

    SINGH, G.

    1999-10-28

    Project W-441, CVD Facility Electrical System CAPTOWDAPPER Study validates Meier's hand calculations. This study includes Load flow, short circuit, voltage drop, protective device coordination, and transient motor starting (TMS) analyses.

  4. Absolute transition probabilities of phosphorus.

    NASA Technical Reports Server (NTRS)

    Miller, M. H.; Roig, R. A.; Bengtson, R. D.

    1971-01-01

    Use of a gas-driven shock tube to measure the absolute strengths of 21 P I lines and 126 P II lines (from 3300 to 6900 A). Accuracy for prominent, isolated neutral and ionic lines is estimated to be 28 to 40% and 18 to 30%, respectively. The data and the corresponding theoretical predictions are examined for conformity with the sum rules.-

  5. Ion beam figuring of CVD silicon carbide mirrors

    NASA Astrophysics Data System (ADS)

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

    2004-06-01

    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 μm 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.

  6. Awareness and Knowledge of Cardiovascular Risk through Blood Pressure and Cholesterol Testing in College Freshmen

    ERIC Educational Resources Information Center

    Melnyk, J. A.; Panza, G.; Zaleski, A.; Taylor, B.

    2015-01-01

    Background: Cardiovascular disease (CVD) is the leading cause of death in the United States, yet knowledge of CVD risk factors is surprisingly low in college students. Purpose: The purpose of this study was to determine the effectiveness of an individualized blood pressure, cholesterol, and CVD education intervention on college freshmen. Methods:…

  7. The Prognostic Value of Family History for the Estimation of Cardiovascular Mortality Risk in Men: Results from a Long-Term Cohort Study in Lithuania

    PubMed Central

    Tamosiunas, Abdonas; Radisauskas, Ricardas; Klumbiene, Jurate; Bernotiene, Gailute; Petkeviciene, Janina; Luksiene, Dalia; Virviciute, Dalia; Malinauskiene, Vilija; Vikhireva, Olga; Grabauskas, Vilius

    2015-01-01

    Aim To evaluate the additional prognostic value of family history for the estimation of cardiovascular (CVD) mortality risk in middle-aged urban Lithuanian men. Methods The association between family history of CVD and the risk of CVD mortality was examined in a population-based cohort of 6,098 men enrolled during 1972–1974 and 1976–1980 in Kaunas, Lithuania. After up to 40 years of follow-up, 2,272 deaths from CVD and 1,482 deaths from coronary heart disease (CHD) were identified. Multivariate Cox proportional hazards models were used to estimate hazard ratios (HR) for CVD and CHD mortality. Results After adjustment for traditional CVD risk factors, the HR for CVD mortality was 1.24 (95% CI 1.09–1.42) and for CHD mortality 1.20 (1.02–1.42) in men with first-degree relatives having a history of myocardial infarction (MI), compared to men without positive family history. A significant effect on the risk of CVD and CHD mortality was also observed for the family history of sudden cardiac death and any CVD. Addition of family history of MI, sudden death, and any CVD to traditional CVD risk factors demonstrated modest improvement in the performance of Cox models for CVD and CHD mortality. Conclusions Family history of CVD is associated with a risk of CVD and CHD mortality significantly and independently of other risk factors in a middle-aged male population. Addition of family history to traditional CVD risk factors improves the prediction of CVD mortality and could be used for identification of high-risk individuals. PMID:26630455

  8. Actual cardiovascular disease risk and related factors: a cross-sectional study of Korean blue collar workers employed by small businesses.

    PubMed

    Won, Jong Uk; Hong, Oi Saeng; Hwang, Won Ju

    2013-04-01

    Actual cardiovascular disease (CVD) risk and related factors among blue collar workers employed by small businesses were investigated. This cross-sectional study of 238 Korean blue collar workers used surveys, anthropometric and blood pressure measurements, and blood sampling for lipid and glucose levels to answer the research questions. Multiple regression techniques were used to analyze study data. The prevalence of actual CVD risk among blue collar workers was 32 cases per 100 workers. A multiple regression model showed that a combination of individual, psychosocial, and work-related factors explained 34% of the variance in actual CVD risk. The significant predictors of actual CVD risk included knowledge of CVD risk, risk perception, job stress, and waist-to-hip ratio. It is important for clinicians to consider all of these significant predictors of actual CVD risk when designing an intervention program to reduce CVD among Korean blue collar workers. PMID:23557345

  9. Optomechanics for absolute rotation detection

    NASA Astrophysics Data System (ADS)

    Davuluri, Sankar

    2016-07-01

    In this article, we present an application of optomechanical cavity for the absolute rotation detection. The optomechanical cavity is arranged in a Michelson interferometer in such a way that the classical centrifugal force due to rotation changes the length of the optomechanical cavity. The change in the cavity length induces a shift in the frequency of the cavity mode. The phase shift corresponding to the frequency shift in the cavity mode is measured at the interferometer output to estimate the angular velocity of absolute rotation. We derived an analytic expression to estimate the minimum detectable rotation rate in our scheme for a given optomechanical cavity. Temperature dependence of the rotation detection sensitivity is studied.

  10. The Absolute Spectrum Polarimeter (ASP)

    NASA Technical Reports Server (NTRS)

    Kogut, A. J.

    2010-01-01

    The Absolute Spectrum Polarimeter (ASP) is an Explorer-class mission to map the absolute intensity and linear polarization of the cosmic microwave background and diffuse astrophysical foregrounds over the full sky from 30 GHz to 5 THz. The principal science goal is the detection and characterization of linear polarization from an inflationary epoch in the early universe, with tensor-to-scalar ratio r much greater than 1O(raised to the power of { -3}) and Compton distortion y < 10 (raised to the power of{-6}). We describe the ASP instrument and mission architecture needed to detect the signature of an inflationary epoch in the early universe using only 4 semiconductor bolometers.

  11. Absolute calibration of optical flats

    DOEpatents

    Sommargren, Gary E.

    2005-04-05

    The invention uses the phase shifting diffraction interferometer (PSDI) to provide a true point-by-point measurement of absolute flatness over the surface of optical flats. Beams exiting the fiber optics in a PSDI have perfect spherical wavefronts. The measurement beam is reflected from the optical flat and passed through an auxiliary optic to then be combined with the reference beam on a CCD. The combined beams include phase errors due to both the optic under test and the auxiliary optic. Standard phase extraction algorithms are used to calculate this combined phase error. The optical flat is then removed from the system and the measurement fiber is moved to recombine the two beams. The newly combined beams include only the phase errors due to the auxiliary optic. When the second phase measurement is subtracted from the first phase measurement, the absolute phase error of the optical flat is obtained.

  12. Gender and age-specific focus needed for cardiovascular outcome measures to improve life-time prevention in high risk women.

    PubMed

    Maas, Angela H E M; Leiner, Tim

    2016-04-01

    Cardiovascular diseases (CVD) have a large variety of clinical manifestations with multiple medical professionals involved. The focus of clinical endpoint trials has often been restricted to limited vascular territories, ignoring many other common manifestations of CVD. In addition, the lack of sex and gender- awareness among healthcare professionals has contributed to the underestimation of CVD risk in especially younger women. We plead for a more multidisciplinary and life-course approach to CVD risk assessment. PMID:26921932

  13. Evaluation of CVD silicon carbide for synchrotron radiation mirrors

    SciTech Connect

    Takacs, P.Z.

    1981-07-01

    Chemical vapor deposited silicon carbide (CVD SiC) is a recent addition to the list of materials suitable for use in the harsh environment of synchrotron radiation (SR) beam lines. SR mirrors for use at normal incidence must be ultrahigh vacuum compatible, must withstand intense x-ray irradiation without surface damage, must be capable of being polished to an extremely smooth surface finish, and must maintain surface figure under thermal loading. CVD SiC exceeds the performance of conventional optical materials in all these areas. It is, however, a relatively new optical material. Few manufacturers have experience in producing optical quality material, and few opticians have experience in figuring and polishing the material. The CVD material occurs in a variety of forms, sensitively dependent upon reaction chamber production conditions. We are evaluating samples of CVD SiC obtained commercially from various manufacturers, representing a range of deposition conditions, to determine which types of CVD material are most suitable for superpolishing. At the time of this writing, samples are being polished by several commercial vendors and surface finish characteristics are being evaluated by various analytical methods.

  14. 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

  15. Cardiovascular Update: Risk, Guidelines, and Recommendations.

    PubMed

    Pearson, Tamera

    2015-09-01

    This article provides an update of the current status of cardiovascular disease (CVD) in the United States, including a brief review of the underlying pathophysiology and epidemiology. This article presents a discussion of the latest American Heart Association guidelines that introduce the concept of promoting ideal cardiovascular health, defined by seven identified metrics. Specific CVD risk factors and utilization of the 10-year CVD event prediction calculator are discussed. In addition, current management recommendations of health-related conditions that increase risk for CVD, such as hypertension and hypercholesterolemia, are provided. Finally, a discussion of detailed evidence-based lifestyle recommendations to promote cardiovascular health and reduce CVD risks concludes the update. PMID:26156147

  16. Development and initial validation of the Cardiovascular Disease Acceptance and Action Questionnaire (CVD-AAQ) in an Italian sample of cardiac patients

    PubMed Central

    Spatola, Chiara A. M.; Cappella, Emanuele A. M.; Goodwin, Christina L.; Baruffi, Matteo; Malfatto, Gabriella; Facchini, Mario; Castelnuovo, Gianluca; Manzoni, Gian Mauro; Molinari, Enrico

    2014-01-01

    Psychological inflexibility refers to the attempt to decrease internal distress even when doing so is inconsistent with life values, and has been identified as a potential barrier to making and maintaining health behavior changes that are consistent with a heart-healthy lifestyle. Disease- and behavior-specific measures of psychological inflexibility have been developed and utilized in treatment research. However, no specific measure has been created for patients with heart disease. Thus, the CardioVascular Disease Acceptance and Action Questionnaire (CVD-AAQ) was developed. The present study is aimed to evaluate the psychometric properties of the CVD-AAQ and to explore its association with measures of psychological adjustment and cardiovascular risk factors in an Italian sample of 275 cardiac patients. Exploratory factor analysis showed a structural one-factor solution with satisfactory internal consistency and test–retest reliability. The relation with other measures was in the expected direction with stronger correlations for the theoretically consistent variables, supporting convergent and divergent validity. CVD-AAQ scores were associated with general psychological inflexibility, anxiety and depression and inversely correlated with psychological well-being. Moreover, the results showed that CVD-AAQ scores are associated with two relevant risk factors for cardiac patients, namely low adherence to medication and being overweight. In sum, results suggest that the CVD-AAQ is a reliable and valid measure of heart disease-specific psychological inflexibility with interesting clinical applications for secondary prevention care. PMID:25452737

  17. Nutrigenetics, plasma lipids, and cardiovascular risk

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cardiovascular disease (CVD) results from complex interactions between genetic and environmental factors. The evidence supports that gene-environment interactions modulate plasma lipid concentrations and potentially CVD risk. Several genes (eg, apolipoprotein A-I and A-IV, apolipoprotein E, and he...

  18. The AFGL absolute gravity program

    NASA Technical Reports Server (NTRS)

    Hammond, J. A.; Iliff, R. L.

    1978-01-01

    A brief discussion of the AFGL's (Air Force Geophysics Laboratory) program in absolute gravity is presented. Support of outside work and in-house studies relating to gravity instrumentation are discussed. A description of the current transportable system is included and the latest results are presented. These results show good agreement with measurements at the AFGL site by an Italian system. The accuracy obtained by the transportable apparatus is better than 0.1 microns sq sec 10 microgal and agreement with previous measurements is within the combined uncertainties of the measurements.

  19. Electron diffraction studies on CVD grown bi-layered graphene

    NASA Astrophysics Data System (ADS)

    Lingam, Kiran; Karakaya, Mehmet; Podila, Ramakrishna; Quin, Haijun; Rao, Apparao; Dept. of Physics and Astronomy, Clemson University, Clemson, SC USA 29634. Team; Advanced Materials Research Laboratories, Clemson University, Anderson, SC USA 29625 Collaboration

    2013-03-01

    Graphene has generated enormous interest in the scientific community due to its peculiar properties like electron mobility, thermal conductivity etc. Several recent reports on exfoliated graphene emphasized the role of layer stacking on the electronic and optical properties of graphene in case of bi-layered and few layered graphene and several synthesis techniques like chemical vapor deposition (CVD) on Copper foils are employed to prepare graphene for applications at a large scale. However, a correlated study pertinent to the stacking order in CVD grown graphene is still unclear. In this work, using a combination of Raman spectroscopy and selected area electron diffraction analysis we analyzed the preferred misorientation angles in a CVD grown bi-layered graphene and also the role of Cu crystal facets on the graphene stacking order will be presented.

  20. Characterization of interfaces in mosaic CVD diamond crystal

    NASA Astrophysics Data System (ADS)

    Muchnikov, Anatoly B.; Radishev, Dmitry B.; Vikharev, Anatoly L.; Gorbachev, Alexei M.; Mitenkin, Anatoly V.; Drozdov, Mikhail N.; Drozdov, Yuri N.; Yunin, Pavel A.

    2016-05-01

    Detailed description of a way to accrete diamond single crystals in one plate using the CVD method is presented. It was found that each region of the mosaic CVD diamond crystal grown over a certain seed substrate "inherits" the crystallographic orientation of its substrate. No correlation was found between the value of misorientation of the accreted crystals and entrance of hydrogen to the boundary. It is shown that successful accretion of single crystal diamond plates in a single mosaic crystal occurs even in the case of great misorientation of crystals. The mechanical stresses appear during the fabrication of the mosaic CVD diamond crystal. Stresses accumulate during accretion of the regions, which grow over substrates with different orientations, in a common structure.

  1. Characteristics of CVD ternary refractory nitride diffusion barriers

    SciTech Connect

    Fleming, J.G.; Smith, P.M.; Custer, J.S.

    1996-11-01

    A range of different ternary refractory nitride compositions have been deposited by CVD (chemical vapor deposition) for the systems TiSiN, WBN, and WSiN. The precursors used are readily available. The structure, electrical, and barrier properties of the films produced by CVD are similar to those observed for films with similar compositions deposited by PVD (physical vapor deposition). The step coverage of the CVD processes developed is good and in some cases, exceptional. A combination of desirable resistivity, step coverage, and barrier properties exists simultaneously over a reasonable range of compositions for each system. Initial attempts to integrate WSiN films into a standard 0.5 micrometer CMOS process flow in place of a sputtered Ti/TiN stack were successful.

  2. The relationship between periodontal disease (pd) and cardiovascular disease (cvd).

    PubMed

    Trevisan, Maurizio; Dorn, Joan

    2010-01-01

    The recent focus on the potential link between periodontal and cardiovascular disease (PD and CVD) is part of the larger renewed interest on the role of infection and inflammation in the etiology of atherosclerosis and its clinical manifestations. Periodontal Disease is an inflammatory process affecting the periodontium, the tissue that surrounds and supports the teeth. The process usually starts with an inflammatory process of the gum (gingivitis) but it may progress with an extensive involvement of the gum, as well as the periodontal ligament and the bone surrounding the teeth resulting in substantial bone loss. Periodontal disease is a common oral pathological condition in the adult age and represents the leading cause of tooth loss. PD prevalence increases with age and there are estimates that up to 49,000,000 Americans may suffer from some form of gum disease. The gingival plaque associated with PD is colonized by a number of gram-positive and gram-negative bacteria that have been shown to affect the initiation and development of PD and have been associated with the potential etiological role of PD in CVD and other chronic conditions. A potential etiological link between PD and CVD may have important public health implications as both the exposure (PD) and the outcomes (CVD) are highly prevalent in industrialized societies. In situations in which both the exposure and the outcome are highly prevalent even modest associations, like those observed in the studies reporting on the link between PD and CVD outcomes, may have relevance. There are not definite data on the effect of periodontal treatment on CVD clinical outcomes (either in primary or secondary prevention) however it should be pointed out that the limited (both in terms of numbers and study design) experimental evidence in humans suggests a possible beneficial effect of periodontal treatment of indices of functional and structural vascular health. PMID:21415980

  3. The extended growth of graphene oxide flakes using ethanol CVD

    NASA Astrophysics Data System (ADS)

    Huang, Jingfeng; Larisika, Melanie; Fam, W. H. Derrick; He, Qiyuan; Nimmo, Myra A.; Nowak, Christoph; Tok, I. Y. Alfred

    2013-03-01

    We report the extended growth of Graphene Oxide (GO) flakes using atmospheric pressure ethanol Chemical Vapor Deposition (CVD). GO was used to catalyze the deposition of carbon on a substrate in the ethanol CVD with Ar and H2 as carrier gases. Raman, SEM, XPS and AFM characterized the growth to be a reduced GO (RGO) of <5 layers. This newly grown RGO possesses lower defect density with larger and increased distribution of sp2 domains than chemically reduced RGO. Furthermore this method without optimization reduces the relative standard deviation of electrical conductivity between chips, from 80.5% to 16.5%, enabling RGO to be used in practical electronic devices.We report the extended growth of Graphene Oxide (GO) flakes using atmospheric pressure ethanol Chemical Vapor Deposition (CVD). GO was used to catalyze the deposition of carbon on a substrate in the ethanol CVD with Ar and H2 as carrier gases. Raman, SEM, XPS and AFM characterized the growth to be a reduced GO (RGO) of <5 layers. This newly grown RGO possesses lower defect density with larger and increased distribution of sp2 domains than chemically reduced RGO. Furthermore this method without optimization reduces the relative standard deviation of electrical conductivity between chips, from 80.5% to 16.5%, enabling RGO to be used in practical electronic devices. Electronic supplementary information (ESI) available: The ethanol CVD setup, TEM of CVD treated RGO, graphite 2D Raman spectra, GO synthesis, transfer and reduction methods and details of characterization techniques are described in the document. See DOI: 10.1039/c3nr33704a

  4. Pantethine, a derivative of vitamin B(5) used as a nutritional supplement, favorably alters low-density lipoprotein cholesterol metabolism in low- to moderate-cardiovascular risk North American subjects: a triple-blinded placebo and diet-controlled investigation.

    PubMed

    Rumberger, John A; Napolitano, Joseph; Azumano, Isao; Kamiya, Toshikazu; Evans, Malkanthi

    2011-08-01

    Safety and efficacy of a biologically active derivative of vitamin B(5) (pantethine) on total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) metabolism was studied in North American subjects at conventional low to moderate cardiovascular disease (CVD) risk. A total of 120 subjects initiated a therapeutic lifestyle change (TLC) diet 4 weeks before randomization (baseline) and maintained the diet throughout a 16-week study period; at baseline, subjects were randomized in a triple-blinded manner to either pantethine (600 mg/d, baseline to week 8, and 900 mg/d, weeks 9-16) or identically labeled, nonbiologically active placebo (n = 60 per group). We hypothesized that pantethine would lower TC and low-density lipoprotein in low-CVD-risk North American subjects in a similar manner as reported in high-CVD-risk subjects studied mainly in Italy and Japan. While sustaining a TLC diet and in comparison with placebo, pantethine demonstrated significant (P < .005) and sustained reductions (from baseline to week 16) in TC (6 mg/dL, 0.16 mmol/L, 3%), LDL-C (4 mg/dL, 0.10 mmol/L, 4%), and apolipoprotein B (4 mg/dL, 0.04 g/L, 5%). Our data suggest that pantethine supplementation for 16 weeks (600 mg/d for weeks 1-8 then 900 mg/d for weeks 9-16) is safe and significantly lowers TC and LDL-C over and above the effect of TLC diet alone. Although the absolute magnitude of these effects was small in these low- to moderate-risk North Americans (4-6 mg/dL), the results are noteworthy as prior studies have shown that, for each 1 mg/dL (0.026 mmol/L) reduction in LDL-C, there is a concomitant 1% reduction in overall future CVD risk. PMID:21925346

  5. Origin of residual particles on transferred graphene grown by CVD

    NASA Astrophysics Data System (ADS)

    Yasunishi, Tomohiro; Takabayashi, Yuya; Kishimoto, Shigeru; Kitaura, Ryo; Shinohara, Hisanori; Ohno, Yutaka

    2016-08-01

    Large-area single-layer graphene can be grown on Cu foil by CVD, but for device applications, the layer must to be transferred onto an insulating substrate. As residual particles are often observed on transferred graphene, we investigated their origin using scanning electron microscopy and energy-dispersive X-ray spectrometry (EDX). The results show that these residual particles are composed either of silicon or an alloy of a few metals, and hence, likely originate from the quartz tube of the CVD furnace and the impurities contained in the Cu foil.

  6. Tractable Chemical Models for CVD of Silicon and Carbon

    NASA Technical Reports Server (NTRS)

    Blanquet, E.; Gokoglu, S. A.

    1993-01-01

    Tractable chemical models are validated for the CVD of silicon and carbon. Dilute silane (SiH4) and methane (CH4) in hydrogen are chosen as gaseous precursors. The chemical mechanism for each systems Si and C is deliberately reduced to three reactions in the models: one in the gas phase and two at the surface. The axial-flow CVD reactor utilized in this study has well-characterized flow and thermal fields and provides variable deposition rates in the axial direction. Comparisons between the experimental and calculated deposition rates are made at different pressures and temperatures.

  7. Schottky barrier solar cells of weakly hydrogenated CVD amorphous silicon

    NASA Astrophysics Data System (ADS)

    Nakashita, T.; Hirose, M.; Osaka, Y.

    1981-01-01

    Electronic properties of CVD a-Si were remarkably improved by hydrogen plasma annealing. As a result, the Schottky-barrier solar cells without an antireflection coating have provided a conversion efficiency of 2.7% at 100 mW/sq cm, and no Staebler-Wronski effect has been observed in the hydrogenated CVD a-Si cell. It is also found that the fill factor is dependent on incident light intensity, because of changes in its series and parallel resistances by light illumination.

  8. 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.

  9. Associations between pre-diabetes, by three different diagnostic criteria, and incident CVD differ in South Asians and Europeans

    PubMed Central

    Eastwood, Sophie V; Tillin, Therese; Sattar, Naveed; Forouhi, Nita G; Hughes, Alun D; Chaturvedi, Nish

    2016-01-01

    Objective We examined longitudinal associations between pre-diabetes and cardiovascular disease (CVD) (coronary heart disease (CHD) and stroke) in Europeans and South Asians. Research design and methods UK cohort study of 1,336 Europeans and 1,139 South Asians, aged 40-69 years at baseline (1988-91). Assessment included blood pressure, blood tests, anthropometry and questionnaires. Pre-diabetes was determined by OGTT or HbA1c, using either International Expert Committee (IEC, HbA1c 6.0-6.5% (42-48 mmol/mol)) or American Diabetes Association (ADA, HbA1c 5.7-6.5% (39-48 mmol/mol)) cut-points. Incident CHD and stroke were established at 20 years from death certification, hospital admission, primary care record review and participant report. Results Compared to normoglycaemic individuals, IEC-defined pre-diabetes was related to both CHD and CVD risk in Europeans but not South Asians (sub-hazards ratio[95% CI]: CHD;1.68[1.19,2.37] vs. 0.99[0.74,1.33], ethnicity interaction p=0.008, CVD; 1.49[1.08,2.07] vs. 1.03[0.79,1.36], ethnicity interaction p=0.04). Conversely, IEC-defined pre-diabetes was associated with stroke risk in South Asians but not Europeans (1.75 [1.04,2.93] vs. 0.85[0.45,1.64], ethnicity interaction p=0.11). Risks were adjusted for age, sex, smoking, total/HDL-cholesterol ratio, waist/hip ratio, systolic blood pressure and anti-hypertensive use. . Associations were weaker for OGTT or ADA-defined pre-diabetes. Conversion from pre-diabetes to diabetes was greater in South Asians, but accounting for time to conversion did not account for these ethnic differences. Conclusions Associations between pre-diabetes and CVD differed by pre-diabetes diagnostic criterion, type of CVD and ethnicity, with associations being present for overall CVD in Europeans but not South Asians. Substantiation of these findings and investigation of potential explanations are required. PMID:26486189

  10. Cardiovascular disease risk factors in native Americans: a literature review.

    PubMed

    Ellis, J L; Campos-Outcalt, D

    1994-01-01

    Cardiovascular disease (CVD) has become the leading cause of death for Native Americans and Alaska Natives. CVD risk factors (diabetes, hypertension, obesity, hypercholesterolemia, smoking, and sedentary lifestyle) have been studied in a number of Native American tribes, and such studies are increasing as the CVD mortality rate rises. This article reviews the literature between 1980 and 1991 concerning the prevalence of CVD risk factors in this population. In addition to summarizing the data, we describe limitations inherent in comparison and address the need for standardization of methodology in future studies. PMID:7848673

  11. Prevalence of 10-Year Risk of Cardiovascular Diseases and Associated Risks in Canadian Adults: The Contribution of Cardiometabolic Risk Assessment Introduction

    PubMed Central

    Setayeshgar, Solmaz; Whiting, Susan J.

    2013-01-01

    Background. Cardiovascular disease (CVD) is the leading cause of death in adult Canadians. Cardiometabolic risk (CMR) derived from 10-year risk of cardiovascular diseases and metabolic syndrome (MetS) needs to be evaluated in Canadian adults. Objective. To determine CMR among Canadian adults by sociodemographic and lifestyle characteristics. Subjects and Methods. Data from the Canadian Health Measures Survey (CHMS), Cycle 1, 2007–2009, was used. Framingham Risk Score (FRS) was implemented to predict 10-year risk of CVD, and metabolic syndrome was identified using the most recent criteria. The 10-year risk of CVD was multiplied by 1.5 in individuals with MetS to obtain CMR. Data were weighted and bootstrapped to be able to generalize the results nationally. Results and Conclusion. CMR gave more accurate estimation of 10-year risk of CVD in Canadian adults from 30 to 74 years than using only FRS. The 10-year risk of CVD in Canadian adults significantly increased when CMR was taken into account from 8.10% to 9.86%. The CVD risk increased by increase in age, decrease in education, and decrease in physical activity and in smokers. Canadians with medium risk of CVD consumed significantly less fruit and vegetable juice compared to Canadians with low risk. No other dietary differences were found. PMID:23738053

  12. Prevalence of 10-year risk of cardiovascular diseases and associated risks in canadian adults: the contribution of cardiometabolic risk assessment introduction.

    PubMed

    Setayeshgar, Solmaz; Whiting, Susan J; Vatanparast, Hassanali

    2013-01-01

    Background. Cardiovascular disease (CVD) is the leading cause of death in adult Canadians. Cardiometabolic risk (CMR) derived from 10-year risk of cardiovascular diseases and metabolic syndrome (MetS) needs to be evaluated in Canadian adults. Objective. To determine CMR among Canadian adults by sociodemographic and lifestyle characteristics. Subjects and Methods. Data from the Canadian Health Measures Survey (CHMS), Cycle 1, 2007-2009, was used. Framingham Risk Score (FRS) was implemented to predict 10-year risk of CVD, and metabolic syndrome was identified using the most recent criteria. The 10-year risk of CVD was multiplied by 1.5 in individuals with MetS to obtain CMR. Data were weighted and bootstrapped to be able to generalize the results nationally. Results and Conclusion. CMR gave more accurate estimation of 10-year risk of CVD in Canadian adults from 30 to 74 years than using only FRS. The 10-year risk of CVD in Canadian adults significantly increased when CMR was taken into account from 8.10% to 9.86%. The CVD risk increased by increase in age, decrease in education, and decrease in physical activity and in smokers. Canadians with medium risk of CVD consumed significantly less fruit and vegetable juice compared to Canadians with low risk. No other dietary differences were found. PMID:23738053

  13. Cosmology with negative absolute temperatures

    NASA Astrophysics Data System (ADS)

    Vieira, J. P. P.; Byrnes, Christian T.; Lewis, Antony

    2016-08-01

    Negative absolute temperatures (NAT) are an exotic thermodynamical consequence of quantum physics which has been known since the 1950's (having been achieved in the lab on a number of occasions). Recently, the work of Braun et al. [1] has rekindled interest in negative temperatures and hinted at a possibility of using NAT systems in the lab as dark energy analogues. This paper goes one step further, looking into the cosmological consequences of the existence of a NAT component in the Universe. NAT-dominated expanding Universes experience a borderline phantom expansion (w < ‑1) with no Big Rip, and their contracting counterparts are forced to bounce after the energy density becomes sufficiently large. Both scenarios might be used to solve horizon and flatness problems analogously to standard inflation and bouncing cosmologies. We discuss the difficulties in obtaining and ending a NAT-dominated epoch, and possible ways of obtaining density perturbations with an acceptable spectrum.

  14. THE RELATIONSHIP BETWEEN OZONE-INDUCED LUNG INJURY, ANTIOXIDANT COMPENSATION AND UNDERLYING CARDIOVASCULAR DISEASE (CVD).

    EPA Science Inventory

    Increased levels of oxidants and compromised compensatory response are associated with CVD susceptibility. We hypothesized that rat strains demonstrating genetic CVD will have lower levels of antioxidants and greater ozone-induced pulmonary injury relative to healthy strains. Mal...

  15. Enhancing the mechanical properties of single-crystal CVD diamond.

    PubMed

    Liang, Qi; Yan, Chih-Shiue; Meng, Yufei; Lai, Joseph; Krasnicki, Szczesny; Mao, Ho-Kwang; Hemley, Russell J

    2009-09-01

    Approaches for enhancing the strength and toughness of single-crystal diamond produced by chemical vapor deposition (CVD) at high growth rates are described. CVD processes used to grow single-crystal diamond in high density plasmas were modified to incorporate boron and nitrogen. Semi-quantitative studies of mechanical properties were carried out using Vickers indentation techniques. The introduction of boron in single-crystal CVD diamond can significantly enhance the fracture toughness of this material without sacrificing its high hardness (∼78 GPa). Growth conditions were varied to investigate its effect on boron incorporation and optical properties by means of photoluminescence, infrared, and ultraviolet-visible absorption spectroscopy. Boron can be readily incorporated into single-crystal diamond by the methods used, but with nitrogen addition, the incorporation of boron was hindered. The spectroscopic measurements indicate that nitrogen and boron coexist in the diamond structure, which helps explain the origin of the enhanced fracture toughness of this material. Further, low pressure/high temperature annealing can enhance the intrinsic hardness of single-crystal CVD diamond by a factor of two without appreciable loss in fracture toughness. This doping and post-growth treatment of diamond may lead to new technological applications that require enhanced mechanical properties of diamond. PMID:21832321

  16. Agreement Between Cardiovascular Disease Risk Scores in Resource-Limited Settings: Evidence from 5 Peruvian Sites

    PubMed Central

    Bazo-Alvarez, Juan Carlos; Quispe, Renato; Peralta, Frank; Poterico, Julio A.; Valle, Giancarlo A.; Burroughs, Melissa; Pillay, Timesh; Gilman, Robert H.; Checkley, William; Malaga, Germán; Smeeth, Liam; Bernabé-Ortiz, Antonio

    2015-01-01

    It is unclear how well currently available risk scores predict cardiovascular disease (CVD) risk in low-income and middle-income countries. We aim to compare the American College of Cardiology/American Heart Association (ACC/AHA) Pooled Cohort risk equations (ACC/AHA model) with 6 other CVD risk tools to assess the concordance of predicted CVD risk in a random sample from 5 geographically diverse Peruvian populations. We used data from 2 Peruvian, age and sex-matched, population-based studies across 5 geographical sites. The ACC/AHA model were compared with 6 other CVD risk prediction tools: laboratory Framingham risk score for CVD, non-laboratory Framingham risk score for CVD, Reynolds risk score, systematic coronary risk evaluation, World Health Organization risk charts, and the Lancet chronic diseases risk charts. Main outcome was in agreement with predicted CVD risk using Lin’s concordance correlation coefficient. Two thousand one hundred and eighty-three subjects, mean age 54.3 (SD ± 5.6) years, were included in the analysis. Overall, we found poor agreement between different scores when compared with ACC/AHA model. When each of the risk scores was used with cut-offs specified in guidelines, ACC/AHA model depicted the highest proportion of people at high CVD risk predicted at 10 years, with a prevalence of 29.0% (95% confidence interval, 26.9–31.0%), whereas prevalence with World Health Organization risk charts was 0.6% (95% confidence interval, 0.2–8.6%). In conclusion, poor concordance between current CVD risk scores demonstrates the uncertainty of choosing any of them for public health and clinical interventions in Latin American populations. There is a need to improve the evidence base of risk scores for CVD in low-income and middle-income countries. PMID:26102017

  17. Agreement Between Cardiovascular Disease Risk Scores in Resource-Limited Settings: Evidence from 5 Peruvian Sites.

    PubMed

    Bazo-Alvarez, Juan Carlos; Quispe, Renato; Peralta, Frank; Poterico, Julio A; Valle, Giancarlo A; Burroughs, Melissa; Pillay, Timesh; Gilman, Robert H; Checkley, William; Malaga, Germán; Smeeth, Liam; Bernabé-Ortiz, Antonio; Miranda, J Jaime

    2015-06-01

    It is unclear how well currently available risk scores predict cardiovascular disease (CVD) risk in low-income and middle-income countries. We aim to compare the American College of Cardiology/American Heart Association (ACC/AHA) Pooled Cohort risk equations (ACC/AHA model) with 6 other CVD risk tools to assess the concordance of predicted CVD risk in a random sample from 5 geographically diverse Peruvian populations. We used data from 2 Peruvian, age and sex-matched, population-based studies across 5 geographical sites. The ACC/AHA model were compared with 6 other CVD risk prediction tools: laboratory Framingham risk score for CVD, non-laboratory Framingham risk score for CVD, Reynolds risk score, systematic coronary risk evaluation, World Health Organization risk charts, and the Lancet chronic diseases risk charts. Main outcome was in agreement with predicted CVD risk using Lin's concordance correlation coefficient. Two thousand one hundred and eighty-three subjects, mean age 54.3 (SD ± 5.6) years, were included in the analysis. Overall, we found poor agreement between different scores when compared with ACC/AHA model. When each of the risk scores was used with cut-offs specified in guidelines, ACC/AHA model depicted the highest proportion of people at high CVD risk predicted at 10 years, with a prevalence of 29.0% (95% confidence interval, 26.9-31.0%), whereas prevalence with World Health Organization risk charts was 0.6% (95% confidence interval, 0.2-8.6%). In conclusion, poor concordance between current CVD risk scores demonstrates the uncertainty of choosing any of them for public health and clinical interventions in Latin American populations. There is a need to improve the evidence base of risk scores for CVD in low-income and middle-income countries. PMID:26102017

  18. Audit of Cardiovascular Disease Risk Factors among Supported Adults with Intellectual Disability Attending an Ageing Clinic

    ERIC Educational Resources Information Center

    Wallace, Robyn A.; Schluter, Philip

    2008-01-01

    Background: Little is known about the cardiovascular disease (CVD) risk factor profile for older adults with intellectual disability (ID). As many CVD risk factors are treatable by lifestyle changes, confirmation of the risk factor profile for older adults with ID could substantially impact upon preventive health practices for this group. Method:…

  19. Joint Effect of Early Microvascular Damage in the Eye & Kidney on Risk of Cardiovascular Events

    PubMed Central

    Yip, Wanfen; Sabanayagam, Charumathi; Ong, Peng Guan; Patel, Uptal D; Chow, Khuan Yew; Tai, E Shyong; Ling, Lieng H; Wong, Tien Yin; Cheung, Carol Yim-lui

    2016-01-01

    Microalbuminuria is associated with an increased risk of cardiovascular disease (CVD), but not all individuals require treatment. Retinal microvascular abnormalities and microalbuminuria reflect early systemic microvascular changes. We examined the joint effect of retinal abnormalities and microalbuminuria on CVD risk in an Asian cohort. We conducted a prospective, population-based study. Retinal abnormalities were defined as presence of retinopathy and/or retinal venular widening. Microalbuminuria was defined as urinary albumin: creatinine ratio between 30–300 mg/g. Incident CVD was defined as newly diagnosed clinical stroke, acute myocardial infarction or CVD death. Cox regression models were performed to determine the associations between retinal abnormalities and microalbuminuria with risk of CVD, while controlling for established risk factors. 3,496 participants (aged ≥ 40) were free of prevalent CVD. During the follow-up (5.8 years), 126 (3.60%) participants developed CVD. Persons presenting with both retinal abnormalities and microalbuminuria were 6.71 times (95% CI, 2.68, 16.79) as likely to have incident CVD compared with those without either abnormalities. There was a significant interaction effect between retinal abnormalities and microalbuminuria on incident CVD. Assessment of retinal abnormalities in patients with microalbuminuria may provide additional value in identifying persons at risk of developing CVD. PMID:27273133

  20. Joint Effect of Early Microvascular Damage in the Eye &Kidney on Risk of Cardiovascular Events.

    PubMed

    Yip, Wanfen; Sabanayagam, Charumathi; Ong, Peng Guan; Patel, Uptal D; Chow, Khuan Yew; Tai, E Shyong; Ling, Lieng H; Wong, Tien Yin; Cheung, Carol Yim-Lui

    2016-01-01

    Microalbuminuria is associated with an increased risk of cardiovascular disease (CVD), but not all individuals require treatment. Retinal microvascular abnormalities and microalbuminuria reflect early systemic microvascular changes. We examined the joint effect of retinal abnormalities and microalbuminuria on CVD risk in an Asian cohort. We conducted a prospective, population-based study. Retinal abnormalities were defined as presence of retinopathy and/or retinal venular widening. Microalbuminuria was defined as urinary albumin: creatinine ratio between 30-300 mg/g. Incident CVD was defined as newly diagnosed clinical stroke, acute myocardial infarction or CVD death. Cox regression models were performed to determine the associations between retinal abnormalities and microalbuminuria with risk of CVD, while controlling for established risk factors. 3,496 participants (aged ≥ 40) were free of prevalent CVD. During the follow-up (5.8 years), 126 (3.60%) participants developed CVD. Persons presenting with both retinal abnormalities and microalbuminuria were 6.71 times (95% CI, 2.68, 16.79) as likely to have incident CVD compared with those without either abnormalities. There was a significant interaction effect between retinal abnormalities and microalbuminuria on incident CVD. Assessment of retinal abnormalities in patients with microalbuminuria may provide additional value in identifying persons at risk of developing CVD. PMID:27273133

  1. Pharmacological Targeting of the Atherogenic Dyslipidemia Complex: The Next Frontier in CVD Prevention Beyond Lowering LDL Cholesterol.

    PubMed

    Xiao, Changting; Dash, Satya; Morgantini, Cecilia; Hegele, Robert A; Lewis, Gary F

    2016-07-01

    Notwithstanding the effectiveness of lowering LDL cholesterol, residual CVD risk remains in high-risk populations, including patients with diabetes, likely contributed to by non-LDL lipid abnormalities. In this Perspectives in Diabetes article, we emphasize that changing demographics and lifestyles over the past few decades have resulted in an epidemic of the "atherogenic dyslipidemia complex," the main features of which include hypertriglyceridemia, low HDL cholesterol levels, qualitative changes in LDL particles, accumulation of remnant lipoproteins, and postprandial hyperlipidemia. We briefly review the underlying pathophysiology of this form of dyslipidemia, in particular its association with insulin resistance, obesity, and type 2 diabetes, and the marked atherogenicity of this condition. We explain the failure of existing classes of therapeutic agents such as fibrates, niacin, and cholesteryl ester transfer protein inhibitors that are known to modify components of the atherogenic dyslipidemia complex. Finally, we discuss targeted repurposing of existing therapies and review promising new therapeutic strategies to modify the atherogenic dyslipidemia complex. We postulate that targeting the central abnormality of the atherogenic dyslipidemia complex, the elevation of triglyceride-rich lipoprotein particles, represents a new frontier in CVD prevention and is likely to prove the most effective strategy in correcting most aspects of the atherogenic dyslipidemia complex, thereby preventing CVD events. PMID:27329952

  2. [Cardiovascular risk assessment and risk stratification- guided therapy: predict, prevent and individualize].

    PubMed

    Ural, Dilek

    2011-09-01

    Modern concept in primary prevention of cardiovascular diseases (CVD) entails assessing the person's global risk and making the right management in accordance with these results. Correspondingly, 3 steps recommended for the prevention of CVD under risk guidance are: (a) risk assessment via a proper system like Framingham Risk Score, SCORE, QRISK, PROCAM; (b) decision-making in the proper management in terms of informing the patient about lifestyle changes that he or she can cope and drug selection; and (c) evaluation of treatment decision in terms of cost effectiveness. Although, a significant decline is observed in CVD morbidity and mortality, particularly in the western countries, we still are trying to approach to competent quality measures about management under CV risk guidance. This review summarizes the main challenges regarding risk stratification-guided management strategy in primary prevention of CVD. PMID:21821497

  3. Shared Risk Factors in Cardiovascular Disease and Cancer.

    PubMed

    Koene, Ryan J; Prizment, Anna E; Blaes, Anne; Konety, Suma H

    2016-03-15

    Cardiovascular disease (CVD) and cancer are the 2 leading causes of death worldwide. Although commonly thought of as 2 separate disease entities, CVD and cancer possess various similarities and possible interactions, including a number of similar risk factors (eg, obesity, diabetes mellitus), suggesting a shared biology for which there is emerging evidence. Although chronic inflammation is an indispensable feature of the pathogenesis and progression of both CVD and cancer, additional mechanisms can be found at their intersection. Therapeutic advances, despite improving longevity, have increased the overlap between these diseases, with millions of cancer survivors now at risk of developing CVD. Cardiac risk factors have a major impact on subsequent treatment-related cardiotoxicity. In this review, we explore the risk factors common to both CVD and cancer, highlighting the major epidemiological studies and potential biological mechanisms that account for them. PMID:26976915

  4. Body Composition Indices and Single and Clustered Cardiovascular Disease Risk Factors in Adolescents: Providing Clinical-Based Cut-Points.

    PubMed

    Gracia-Marco, Luis; Moreno, Luis A; Ruiz, Jonatan R; Ortega, Francisco B; de Moraes, Augusto César Ferreira; Gottrand, Frederic; Roccaldo, Romana; Marcos, Ascensión; Gómez-Martínez, Sonia; Dallongeville, Jean; Kafatos, Anthony; Molnar, Denes; Bueno, Gloria; de Henauw, Stefaan; Widhalm, Kurt; Wells, Jonathan C

    2016-01-01

    The aims of the present study in adolescents were 1) to examine how various body composition-screening tests relate to single and clustered cardiovascular disease (CVD) risk factors, 2) to examine how lean mass and body fatness (independently of each other) relate to clustered CVD risk factors, and 3) to calculate specific thresholds for body composition indices associated with an unhealthier clustered CVD risk. We measured 1089 European adolescents (46.7% boys, 12.5-17.49years) in 2006-2007. CVD risk factors included: systolic blood pressure, maximum oxygen uptake, homeostasis model assessment, C-reactive protein (n=748), total cholesterol/high density lipoprotein cholesterol and triglycerides. Body composition indices included: height, body mass index (BMI), lean mass, the sum of four skinfolds, central/peripheral skinfolds, waist circumference (WC), waist-to-height ratio (WHtR) and waist-to-hip ratio (WHR). Most body composition indices are associated with single CVD risk factors. The sum of four skinfolds, WHtR, BMI, WC and lean mass are strong and positively associated with clustered CVD risk. Interestingly, lean mass is positively associated with clustered CVD risk independently of body fatness in girls. Moderate and highly accurate thresholds for the sum of four skinfolds, WHtR, BMI, WC and lean mass are associated with an unhealthier clustered CVD risk (all AUC>0.773). In conclusion, our results support an association between most of the assessed body composition indices and single and clustered CVD risk factors. In addition, lean mass (independent of body fatness) is positively associated with clustered CVD risk in girls, which is a novel finding that helps to understand why an index such as BMI is a good index of CVD risk but a bad index of adiposity. Moderate to highly accurate thresholds for body composition indices associated with a healthier clustered CVD risk were found. Further studies with a longitudinal design are needed to confirm these findings

  5. Inflammatory arthritis as a novel risk factor for cardiovascular disease.

    PubMed

    John, Holly; Kitas, George

    2012-10-01

    Cardiovascular disease (CVD) comorbidity is a significant issue for the inflammatory arthritides (IA). There is a wealth of mortality studies showing increased cardiovascular mortality in rheumatoid arthritis (RA) and the evidence suggests that the same is likely to be true of psoriatic arthritis (PsA) and ankylosing spondylitis (AS). CVD co-morbidity is due to ischaemic pathologies driven by accelerated atherosclerosis and relates to the increased prevalence and clustering of classical risk factors, which may also be affected by treatments for IA, and their interplay with novel risk factors, namely systemic inflammation. Currently we are unable to quantify the contribution that classical and novel risk factors make to an individuals' CVD risk and specific algorithms need to be developed and validated in RA, PsA and AS to facilitate clinical management. Furthermore, large clinical trials are required to assess the effect of lifestyle modifications, primary prevention strategies and effective immunosuppression on hard CVD endpoints. However, in the meantime, a pragmatic approach should be adopted towards CVD risk management. Consensus opinion has generated guidelines for the management of CVD risk in IA and we discuss the importance of assessing each individual for CVD risk and establishing a system for routine risk factor identification alongside a commitment to treat identified risk factors to specific targets. PMID:22841864

  6. Improving HST Pointing & Absolute Astrometry

    NASA Astrophysics Data System (ADS)

    Lallo, Matthew; Nelan, E.; Kimmer, E.; Cox, C.; Casertano, S.

    2007-05-01

    Accurate absolute astrometry is becoming increasingly important in an era of multi-mission archives and virtual observatories. Hubble Space Telescope's (HST's) Guidestar Catalog II (GSC2) has reduced coordinate error to around 0.25 arcsecond, a factor 2 or more compared with GSC1. With this reduced catalog error, special attention must be given to calibrate and maintain the Fine Guidance Sensors (FGSs) and Science Instruments (SIs) alignments in HST to a level well below this in order to ensure that the accuracy of science product's astrometry keywords and target positioning are limited only by the catalog errors. After HST Servicing Mission 4, such calibrations' improvement in "blind" pointing accuracy will allow for more efficient COS acquisitions. Multiple SIs and FGSs each have their own footprints in the spatially shared HST focal plane. It is the small changes over time in primarily the whole-body positions & orientations of these instruments & guiders relative to one another that is addressed by this work. We describe the HST Cycle 15 program CAL/OTA 11021 which, along with future variants of it, determines and maintains positions and orientations of the SIs and FGSs to better than 50 milli- arcseconds and 0.04 to 0.004 degrees of roll, putting errors associated with the alignment sufficiently below GSC2 errors. We present recent alignment results and assess their errors, illustrate trends, and describe where and how the observer sees benefit from these calibrations when using HST.

  7. Absolute oral bioavailability of ciprofloxacin.

    PubMed

    Drusano, G L; Standiford, H C; Plaisance, K; Forrest, A; Leslie, J; Caldwell, J

    1986-09-01

    We evaluated the absolute bioavailability of ciprofloxacin, a new quinoline carboxylic acid, in 12 healthy male volunteers. Doses of 200 mg were given to each of the volunteers in a randomized, crossover manner 1 week apart orally and as a 10-min intravenous infusion. Half-lives (mean +/- standard deviation) for the intravenous and oral administration arms were 4.2 +/- 0.77 and 4.11 +/- 0.74 h, respectively. The serum clearance rate averaged 28.5 +/- 4.7 liters/h per 1.73 m2 for the intravenous administration arm. The renal clearance rate accounted for approximately 60% of the corresponding serum clearance rate and was 16.9 +/- 3.0 liters/h per 1.73 m2 for the intravenous arm and 17.0 +/- 2.86 liters/h per 1.73 m2 for the oral administration arm. Absorption was rapid, with peak concentrations in serum occurring at 0.71 +/- 0.15 h. Bioavailability, defined as the ratio of the area under the curve from 0 h to infinity for the oral to the intravenous dose, was 69 +/- 7%. We conclude that ciprofloxacin is rapidly absorbed and reliably bioavailable in these healthy volunteers. Further studies with ciprofloxacin should be undertaken in target patient populations under actual clinical circumstances. PMID:3777908

  8. Absolute Instability in Coupled-Cavity TWTs

    NASA Astrophysics Data System (ADS)

    Hung, D. M. H.; Rittersdorf, I. M.; Zhang, Peng; Lau, Y. Y.; Simon, D. H.; Gilgenbach, R. M.; Chernin, D.; Antonsen, T. M., Jr.

    2014-10-01

    This paper will present results of our analysis of absolute instability in a coupled-cavity traveling wave tube (TWT). The structure mode at the lower and upper band edges are respectively approximated by a hyperbola in the (omega, k) plane. When the Briggs-Bers criterion is applied, a threshold current for onset of absolute instability is observed at the upper band edge, but not the lower band edge. The nonexistence of absolute instability at the lower band edge is mathematically similar to the nonexistence of absolute instability that we recently demonstrated for a dielectric TWT. The existence of absolute instability at the upper band edge is mathematically similar to the existence of absolute instability in a gyroton traveling wave amplifier. These interesting observations will be discussed, and the practical implications will be explored. This work was supported by AFOSR, ONR, and L-3 Communications Electron Devices.

  9. Cardiovascular Risk Profile at the Onset of Psoriatic Arthritis: a Population-based, Cohort Study

    PubMed Central

    Ernste, F.C.; Sánchez-Menéndez, M.; Wilton, K. M.; Crowson, C.S.; Matteson, E.L.; Kremers, H. Maradit

    2015-01-01

    Objective The role of cardiovascular disease (CVD) risk factors in psoriatic arthritis (PsA) is poorly understood. We examined the prevalence of CVD risk factors at initial onset of PsA and compared the observed incidence of CVD events with that predicted by the Framingham risk score (FRS) to determine its applicability in this patient population. Methods A population-based incidence cohort of 158 patients with PsA who fulfilled ClASsification of Psoriatic ARthritis (CASPAR) criteria for PsA in 1989–2008 was assembled. Medical records were reviewed to ascertain CVD risk factors and CVD events. Future risk of CVD disease was estimated using the FRS algorithm. Results Mean age was 43.4 years (range: 19–74 years), 61% were men and 44% were obese (body mass index ≥30kg/m2). Fifty-four (34%) patients presented with ≥2 CVD risk factors at PsA incidence. Among 126 patients aged ≥ 30 years at PsA incidence with no prior history of CVD, 33% had FRS ≥10% with 11% having FRS ≥ 20% and 18 experienced a CVD event in the first 10 years of disease duration. The 10 year cumulative incidence of CVD events was 17% (95% confidence interval [CI]: 10–24%), almost twice as high as the predicted incidence based on the FRS (Standardized incidence ratio: 1.80; 95% CI: 1.14–2.86; p=0.012). Conclusion The majority of newly diagnosed PsA patients have a >10% risk of CVD disease within 10 years of PsA incidence. The CVD risk in these patients is higher than expected and underestimated by the FRS. PMID:25581120

  10. Multiwalled carbon nanotube CVD synthesis, modification, and composite applications

    NASA Astrophysics Data System (ADS)

    Qian, Dali

    Well-aligned carbon multiwall nanotube (MWNT) arrays have been continuously synthesized by a floating catalytic chemical vapor deposition (CVD) method involving the pyrolysis of xylene-ferrocene mixtures. The CVD parameters have been studied to selectively synthesize nanotubes with required dimensions. A mixed tip-root growth model has been proposed for the floating catalytic CVD synthesis. Coarsening of the catalyst particle at the root end promoted MWNT wall coarsening (addition of new concentric graphene shells), while the smaller catalyst particle at the tip contributed to MWNT elongation. A two-step process in which ferrocene was fed for only five minutes to nucleate the DTs was developed to understand if a continuous supply of catalyst was necessary for continued growth. The results show that the ferrocene was only necessary for initial nucleation. To simplify the CVD process further, another two-step synthesis method was developed in which the ferrocene was pre-decomposed so that the nanotube nucleation could be isolated from the growth, enabling quantification of growth mechanisms and kinetics. Mass spectra and hydrocarbon analyses of the CVD reactor tail gas were performed to understand the pyrolysis chemistry. Well-aligned N-doped and Ru-doped MWNT arrays have been produced by pyrolysis of pyridine ferrocene mixtures and xylene-ferrocene-ruthenocene mixtures, respectively. Various material characterization techniques were used to measure the dopant distributions and correlate the catalyst phase with the novel nanotube structures. High-temperature annealing has been shown to be a viable means to remove both the catalyst particles and certain microstructural defects within the CVD-derived DTs. The phase transformation of catalyst during annealing has also been studied. Homogeneous distribution of MWNTs in polystyrene matrices was achieved by an ultrasonic assisted solution-evaporation method. Addition of only 1 wt % DTs to polystyrene increased the polymer

  11. Large-scale quantification of CVD graphene surface coverage

    NASA Astrophysics Data System (ADS)

    Ambrosi, Adriano; Bonanni, Alessandra; Sofer, Zdeněk; Pumera, Martin

    2013-02-01

    The extraordinary properties demonstrated for graphene and graphene-related materials can be fully exploited when a large-scale fabrication procedure is made available. Chemical vapor deposition (CVD) of graphene on Cu and Ni substrates is one of the most promising procedures to synthesize large-area and good quality graphene films. Parallel to the fabrication process, a large-scale quality monitoring technique is equally crucial. We demonstrate here a rapid and simple methodology that is able to probe the effectiveness of the growth process over a large substrate area for both Ni and Cu substrates. This method is based on inherent electrochemical signals generated by the underlying metal catalysts when fractures or discontinuities of the graphene film are present. The method can be applied immediately after the CVD growth process without the need for any graphene transfer step and represents a powerful quality monitoring technique for the assessment of large-scale fabrication of graphene by the CVD process.The extraordinary properties demonstrated for graphene and graphene-related materials can be fully exploited when a large-scale fabrication procedure is made available. Chemical vapor deposition (CVD) of graphene on Cu and Ni substrates is one of the most promising procedures to synthesize large-area and good quality graphene films. Parallel to the fabrication process, a large-scale quality monitoring technique is equally crucial. We demonstrate here a rapid and simple methodology that is able to probe the effectiveness of the growth process over a large substrate area for both Ni and Cu substrates. This method is based on inherent electrochemical signals generated by the underlying metal catalysts when fractures or discontinuities of the graphene film are present. The method can be applied immediately after the CVD growth process without the need for any graphene transfer step and represents a powerful quality monitoring technique for the assessment of large

  12. 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

  13. Challenges and Opportunities in the Management of Cardiovascular Risk Factors in Youth With Type 1 Diabetes: Lifestyle and Beyond.

    PubMed

    Katz, Michelle; Giani, Elisa; Laffel, Lori

    2015-12-01

    Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in persons with type 1 diabetes (T1D). Specific risk factors associated with diabetes, such as hyperglycemia and kidney disease, have been demonstrated to increase the incidence and progression of CVD. Nevertheless, few data exist on the effects of traditional risk factors such as dyslipidemia, obesity, and hypertension on CVD risk in youth with T1D. Improvements in understanding and approaches to the evaluation and management of CVD risk factors, specifically for young persons with T1D, are desirable. Recent advances in noninvasive techniques to detect early vascular damage, such as the evaluation of endothelial dysfunction and aortic or carotid intima-media thickness, provide new tools to evaluate the progression of CVD in childhood. In the present review, current CVD risk factor management, challenges, and potential therapeutic interventions in youth with T1D are described. PMID:26520142

  14. Absolute negative mobility of interacting Brownian particles

    NASA Astrophysics Data System (ADS)

    Ou, Ya-li; Hu, Cai-tian; Wu, Jian-chun; Ai, Bao-quan

    2015-12-01

    Transport of interacting Brownian particles in a periodic potential is investigated in the presence of an ac force and a dc force. From Brownian dynamic simulations, we find that both the interaction between particles and the thermal fluctuations play key roles in the absolute negative mobility (the particle noisily moves backwards against a small constant bias). When no the interaction acts, there is only one region where the absolute negative mobility occurs. In the presence of the interaction, the absolute negative mobility may appear in multiple regions. The weak interaction can be helpful for the absolute negative mobility, while the strong interaction has a destructive impact on it.

  15. Is Implantation of a Left Ventricular Assist Device in Patients With Critical or Impending Cardiogenic Shock an Absolute Contraindication? Looking Back at Our Past Experience Trying to Identify Contraindicative Risk Factors.

    PubMed

    Dell'Aquila, Angelo Maria; Schneider, Stefan R B; Risso, Paolo; Welp, Henryk; Glockner, David G; Alles, Sebastian; Sindermann, Jürgen R; Scherer, Mirela

    2015-12-01

    Poor survival has been demonstrated after ventricular assist device (VAD) implantation for Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) profile 1 and 2 patients compared with more stable levels. However, risk factors within this high-risk cohort have not been determined so far. The aim of the present study was to identify risk factors associated with this very high mortality rate. Between February 1993 and January 2013, 298 patients underwent VAD implantation in our institution. One hundred nine patients were in INTERMACS level 1 and 49 patients were in INTERMACS level 2 and were therefore defined as hemodynamically critical (overall 158 patients). Assist devices implanted were: HVAD HeartWare n = 18; Incor n = 11; VentrAssist n = 2; DeBakey n = 22; and pulsatile systems n = 105. After cumulative support duration of 815.35 months, Kaplan-Meier analysis revealed a survival of 63.9, 48.8, and 40.3% at 1, 6, and 12 months, respectively. Cox regression analyses identified age > 50 (P = 0.001, odds ratio [OR] 2.48), white blood cell count > 13.000/μL (P = 0.01, OR 2.06), preoperative renal replacement therapy (P = 0.001, OR 2.63), and postcardiotomy failure (P < 0.001, OR 2.79) as independent predictors of mortality. Of note, last generation VADs were not associated with significantly better 6-month survival (P = 0.59). Patients without the aforementioned risk factors could yield a survival of 79.2% at 6 months. This single-center experience shows that VAD implantation in hemodynamically unstable patients generally results in poor early outcome, even in third-generation pumps. However, avoiding the aforementioned risk factors could result in improved outcome. PMID:26011007

  16. Cold Vacuum Drying (CVD) OCRWM Loop Error Determination

    SciTech Connect

    PHILIPP, B.L.

    2000-07-26

    Characterization is specifically identified by the Richland Operations Office (RL) for the Office of Civilian Radioactive Waste Management (OCRWM) of the US Department of Energy (DOE), as requiring application of the requirements in the Quality Assurance Requirements and Description (QARD) (RW-0333P DOE 1997a). Those analyses that provide information that is necessary for repository acceptance require application of the QARD. The cold vacuum drying (CVD) project identified the loops that measure, display, and record multi-canister overpack (MCO) vacuum pressure and Tempered Water (TW) temperature data as providing OCRWM data per Application of the Office of Civilian Radioactive Waste Management (OCRWM) Quality Assurance Requirements to the Hanford Spent Nuclear Fuel Project HNF-SD-SNF-RPT-007. Vacuum pressure transmitters (PT 1*08, 1*10) and TW temperature transmitters (TIT-3*05, 3*12) are used to verify drying and to determine the water content within the MCO after CVD.

  17. Characterisation of scCVD diamond detectors with γ sources

    NASA Astrophysics Data System (ADS)

    Caiffi, B.; Amapane, N.; Argirò, S.; Battaglieri, M.; Beolé, S.; De Vita, R.; Masera, M.; Mila, G.; Osipenko, M.; Ripani, M.; Taiuti, M.

    2014-08-01

    A single-crystal CVD (Chemical Vapor Deposition) diamond detector was used to measure γ rays in order to assess its performance in terms of energy resolution and linearity. For this purpose, 57Co, 133Ba, 22Na, 207Bi and 137Cs γ sources were used. Electrons scattered by the backward Compton process were detected in the diamond, in coincidence with (backscattered) γs measured in a NaI detector, placed at 180° from the CVD diamond detector with respect to the source. The resulting calibration shows a linear dependence of the charge deposited in the diamond and a resolution of about 24 keV FWHM for the energy of the incident γs between 40 keV (57Co) and 477 keV (137Cs), comparable with the resolution of our electronic chain.

  18. THERMAL DIFFUSIVITY/CONDUCTIVITY OF IRRADIATED MONOLITHIC CVD-SIC

    SciTech Connect

    Youngblood, Gerald E.; Senor, David J.; Jones, Russell H.

    2003-03-31

    Several thermal diffusivity disc samples of high purity CVD-SiC were neutron-irradiated to equivalent doses of about 5-8 dpa-SiC at temperatures from 252 up to 800 C. For this temperature range, the degradation in the thermal diffusivity ranged from about 95 percent down to 89 percent, respectively. The reciprocal thermal diffusivity method was used to estimate the phonon mean free paths and defect concentrations before and after the irradiations for these materials. Even though the CVD-SiC material is an excellent monitor of certain neutron irradiation effects, the degradation in the thermal diffusivity (conductivity) appears to be more than a factor of two greater than predicted by recent theoretical model simulations.

  19. Single crystal and polycrystalline CVD diamond for demanding optical applications

    NASA Astrophysics Data System (ADS)

    Dodson, J. M.; Brandon, J. R.; Dhillon, H. K.; Friel, I.; Geoghegan, S. L.; Mollart, T. P.; Santini, P.; Scarsbrook, G. A.; Twitchen, D. J.; Whitehead, A. J.; Wilman, J. J.; de Wit, H.

    2011-06-01

    Diamond's extremely wide transparency, combined with its other exceptional properties including hardness, strength and thermal conductivity make it a desirable material for optical windows. Polycrystalline diamond grown by chemical vapour deposition (CVD) has become the preferred window material for high power CO2 laser systems since its development in the 1990s. The range and availability of diamond materials is expanding, and in recent years has been extended to include CVD single crystal diamond. This paper reviews the quality of these materials, looking at optical scatter and absorption around 1 and 10 microns, along with their thermal and mechanical properties. We also discuss selection of appropriate grades and how they may best be integrated into demanding optical applications.

  20. Designed CVD growth of graphene via process engineering.

    PubMed

    Yan, Kai; Fu, Lei; Peng, Hailin; Liu, Zhongfan

    2013-10-15

    Graphene, the atomic thin carbon film with honeycomb lattice, holds great promise in a wide range of applications, due to its unique band structure and excellent electronic, optical, mechanical, and thermal properties. Scientists are researching this star material because of the development of various emerging preparation techniques, among which chemical vapor deposition (CVD) has received the fastest advances in the past few years. For the CVD growth of graphene, the ultimate goal is to achieve the highest quality in the largest scale and lowest cost with a precise control of layer thickness, stacking order, and crystallinity. To meet this goal, researchers need a comprehensive understanding and effective controlling of the growth process, especially to its elementary steps. In this Account, we focus on our recent progresses toward the controlled surface growth of graphene and its two-dimensional (2D) hybrids via rational designs of CVD elementary processes, namely, process engineering. A typical CVD process consists of four main elementary steps: (A) adsorption and catalytic decomposition of precursor gas, (B) diffusion and dissolution of decomposed carbon species into bulk metal, (C) segregation of dissolved carbon atoms onto the metal surface, and finally, (D) surface nucleation and growth of graphene. Absence or enhancement of each elementary step would lead to significant changes in the whole growth process. Metals with certain carbon solubility, such as nickel and cobalt, involve all four elementary steps in a typical CVD process, thus providing us an ideal system for process engineering. The elementary segregation process can be completely blocked if molybdenum is introduced into the system as an alloy catalyst, yielding perfect monolayer graphene almost independent of growth parameters. On the other hand, the segregation-only process of predissolved solid carbons is also capable of high-quality graphene growth. By using a synergetic Cu-Ni alloy, we are

  1. Electronic properties of CVD graphene grown on copper

    NASA Astrophysics Data System (ADS)

    Cao, Helin; Yu, Qingkai; Jauregui, Luis A.; Tian, Jifa; Wu, Wei; Liu, Zhihong; Jalilian, Romaneh; Benjamin, Daniel K.; Jiang, Zhigang; Bao, Jiming; Pei, Steven S.; Chen, Yong P.

    2010-03-01

    We report the electronic properties of graphene grown by chemical vapor deposition (CVD) on copper foils at ambient pressure. Large size graphene films (4 inch*4 inch) are synthesized and transferred to SiO2/Si substrate. Raman mapping demonstrates that the films consist primarily of monolayer graphene (up to ˜90% area coverage). Low temperature transport measurements are performed on devices made from such CVD graphene. The ``half-integer'' quantum Hall effect, which is the hall-mark of mono-layer graphene, has been observed in these devices. We also observe the ambipolar field effect and weak localization, which allow us to extract carrier mobility ˜3000cm^2/Vs and phase coherence length ˜300nm at 1.5K.

  2. CVD diamond screens for photon beam imaging at PETRA III

    NASA Astrophysics Data System (ADS)

    Degenhardt, M.; Aprigliano, G.; Schulte-Schrepping, H.; Hahn, U.; Grabosch, H.-J.; Wörner, E.

    2013-03-01

    PETRA III, the most brilliant storage-ring-based synchrotron radiation source in the world, started its operation in 2009. It features 14 undulator beamlines and will be extended by further 10 beamlines in the PETRA III extension project. During the startup phase of the 14 PETRA III beamlines, fluorescence monitors based on CVD diamond screens have proven to be a very powerful tool for the monitoring of the attenuated undulator beams and for the commissioning of the optical components, e.g. slit systems and monochromators. They served as the essential instrument for the initial setup of the positron beam orbit to align the undulator photon beam along the beamline. The application of CVD diamond screens for the beam imaging at PETRA III beamlines is presented. Images taken during the beam adjustment and the beamline commissioning are shown.

  3. Argan oil improves surrogate markers of CVD in humans.

    PubMed

    Sour, Souad; Belarbi, Meriem; Khaldi, Darine; Benmansour, Nassima; Sari, Nassima; Nani, Abdelhafid; Chemat, Farid; Visioli, Francesco

    2012-06-01

    Limited - though increasing - evidence suggests that argan oil might be endowed with potential healthful properties, mostly in the areas of CVD and prostate cancer. We sought to comprehensively determine the effects of argan oil supplementation on the plasma lipid profile and antioxidant status of a group of healthy Algerian subjects, compared with matched controls. A total of twenty healthy subjects consumed 15 g/d of argan oil - with toasted bread - for breakfast, during 4 weeks (intervention group), whereas twenty matched controls followed their habitual diet, but did not consume argan oil. The study lasted 30 d. At the end of the study, argan oil-supplemented subjects exhibited higher plasma vitamin E concentrations, lower total and LDL-cholesterol, lower TAG and improved plasma and cellular antioxidant profile, when compared with controls. In conclusion, we showed that Algerian argan oil is able to positively modulate some surrogate markers of CVD, through mechanisms which warrant further investigation. PMID:22082585

  4. Infrared absorption of fs-laser textured CVD diamond

    NASA Astrophysics Data System (ADS)

    Calvani, P.; Bellucci, A.; Girolami, M.; Orlando, S.; Valentini, V.; Polini, R.; Mezzetti, A.; Di Fonzo, F.; Trucchi, D. M.

    2016-03-01

    Nanoscale periodic texturing on polycrystalline CVD diamond surface was performed to obtain a significant increase in optical absorptance to visible and near-infrared radiation. Surface texturing, obtained by the use of fs-laser ultrashort pulses, has been demonstrated to induce a controlled periodicity of ripples of about 170 nm and length of several µm, able to drastically increase the diamond capability of interacting with solar radiation from its intrinsic visible blindness. Ultraviolet and visible Raman spectroscopy has been used to confirm the absence of non-diamond phases resulting from the process for the fs-laser-textured sample. Moreover, here we investigate the optical properties in the range 200 nm-25 µm. Absorbance of fs-laser-textured CVD diamond is considerably higher than the untreated one at every wavelength, resulting in a remarkable increase in the emittance: It points out the need for an optimization of process parameters to enhance the selective absorption capability.

  5. 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. PMID:25821810

  6. 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

  7. Electroluminescent and photosensitive films prepared by DTC-CVD method

    NASA Astrophysics Data System (ADS)

    Zavyalova, Ludmila V.; Svechnikov, George S.

    1997-08-01

    The original chemical vapor deposition (CVD) method used in fabrication A2B6 films, photodetectors and electro- luminescent emitters based on these films have been reported. The basic idea behind this method is thermal decomposition of dithiocarbamates (DTC). The proposed method does not require expensive materials and vacuum equipment. Moreover, the DTC-CVD method differs from the known CVD methods in source material delivery method, a low deposition temperature and a non-sealed reactor geometry. Both CdS and CdS1-xSex were obtained at temperature of 240- 280 degrees C and were activated directly in the grown process by Cu and In, or by annealing in mixture CdS: Cu, Cl. Photodetectors with absorption maxima at 500-750 nm have dark conductivity (sigma) D EQ 10-9 divided by 10-8 (Omega) -1 cm-1 and photoconductivity (sigma) ph equals 10-2 divided by 10-1 (Omega) -1 cm-1 at 200 lux. CdS films with thickness of 6 divided by 12 micrometers have been used as sandwich-type photoconductor detectors. Electroluminescence ZnS:Mn films prepared by DTC-CVD method at the substrate temperature of 200 DIV 300 degrees C without additional annealing have high luminance and luminous efficiency. Deposition at a law temperature makes it possible to use flexible polymer films or low cost glasses as substrates. Because the technique is rather simple and can be applied to obtain all types of thin film electroluminescence structure layers, we expect a low price of light sources based on these films.

  8. Electrochromic behavior in CVD grown tungsten oxide films

    NASA Astrophysics Data System (ADS)

    Gogova, D.; Iossifova, A.; Ivanova, T.; Dimitrova, Zl; Gesheva, K.

    1999-03-01

    Solid state electrochemical devices (ECDs) for smart windows, large area displays and automobile rearview mirrors are of considerable technological and commercial interest. In this paper, we studied the electrochromic properties of amorphous and polycrystalline CVD carbonyl tungsten oxide films and the possibility for sol-gel thin TiO 2 film to play the role of passive electrode in an electrochromic window with solid polymer electrolyte.

  9. Ultra-high Burst Strength of CVD Graphene Membranes

    NASA Astrophysics Data System (ADS)

    Wang, Luda; Boutilier, Michael; Kidambi, Piran; Karnik, Rohit; Microfluidics; Nanofluidics Research Lab Team

    2015-11-01

    Porous graphene membranes have significant potential in gas separation, water desalination and nanofiltration. Understanding the mechanical strength of porous graphene is crucial because membrane separations can involve high pressures. We studied the burst strength of CVD graphene membrane placed on porous support at applied pressures up to 100 bar by monitoring the gas flow rate across the membrane as a function of pressure. Increase of gas flow rate with pressure allowed for extraction of the burst fraction of graphene as it failed under increasing pressure. We also studied the effect of sub-nanometer pores on the ability of graphene to withstand pressure. The results showed that porous graphene membranes can withstand pressures comparable to or even higher than the >50 bar pressures encountered in water desalination, with non-porous CVD graphene exhibiting even higher mechanical strength. Our study shows that porous polycrystalline CVD graphene has ultra-high burst strength under applied pressure, suggesting the possibility for its use in high-pressure membrane separations. Principal Investigator

  10. CVD silicon carbide characterization. Final report, August 1992-October 1993

    SciTech Connect

    Graves, G.A.; Iden, D.

    1994-08-01

    Chemically vapor deposited (CVD) silicon carbide is a candidate material for high quality ground and space-based mirror substrates and high quality reflective optics. Statistically valid material property data has not been available, however, to make durability and lifetime predictions for such optics. The primary purpose of this study was to determine the Weibull and slow crack growth parameters for CVD silicon carbide. Specimens were cut from various locations in a 25 mm thick, 50 cm diameter piece of SiC to analyze bulk material property homogeneity. Flexural strength was measured using a four-point bend technique. In addition to mechanical testing for strength, hardness, and fracture toughness, the material crystallography and microstructure were studied. Thermal expansion, thermal diffusivity, specific heat, optical absorption, and infrared reflectivity measurements were also conducted. Raman spectroscopy was used to check for any residual stress. Test results show this CVD silicon carbide is a high-purity, homogeneous, fine-grained substrate material with very good mechanical, optical, and thermal properties.

  11. Large-scale quantification of CVD graphene surface coverage.

    PubMed

    Ambrosi, Adriano; Bonanni, Alessandra; Sofer, Zdeněk; Pumera, Martin

    2013-03-21

    The extraordinary properties demonstrated for graphene and graphene-related materials can be fully exploited when a large-scale fabrication procedure is made available. Chemical vapor deposition (CVD) of graphene on Cu and Ni substrates is one of the most promising procedures to synthesize large-area and good quality graphene films. Parallel to the fabrication process, a large-scale quality monitoring technique is equally crucial. We demonstrate here a rapid and simple methodology that is able to probe the effectiveness of the growth process over a large substrate area for both Ni and Cu substrates. This method is based on inherent electrochemical signals generated by the underlying metal catalysts when fractures or discontinuities of the graphene film are present. The method can be applied immediately after the CVD growth process without the need for any graphene transfer step and represents a powerful quality monitoring technique for the assessment of large-scale fabrication of graphene by the CVD process. PMID:23396554

  12. Deposition of moisture barrier films by catalytic CVD using hexamethyldisilazane

    NASA Astrophysics Data System (ADS)

    Ohdaira, Keisuke; Matsumura, Hideki

    2014-01-01

    Hexamethyldisilazane (HMDS) is utilized to deposit moisture barrier films by catalytic chemical vapor deposition (Cat-CVD). An increase in the thickness of silicon oxynitride (SiOxNy) films leads to a better water-vapor transmission rate (WVTR), indicating that Cat-CVD SiOxNy films deposited using HMDS do not severely suffer from cracking. A WVTR on the order of 10-3 g m-2 day-1 can be realized by a Cat-CVD SiOxNy film formed using HMDS on a poly(ethylene terephthalate) (PET) substrate without any stacking structures at a substrate temperature of as low as 60 °C. X-ray reflectivity (XRR) measurement reveals that a film density of >2.0 g/cm3 is necessary for SiOxNy films to demonstrate an effective moisture barrier ability. The use of HMDS will give us safer production of moisture barrier films because of its non-explosive and non-toxic nature.

  13. Controlled CVD growth of Cu-Sb alloy nanostructures

    NASA Astrophysics Data System (ADS)

    Chen, Jing; Yin, Zongyou; Sim, Daohao; Tay, Yee Yan; Zhang, Hua; Ma, Jan; Hng, Huey Hoon; Yan, Qingyu

    2011-08-01

    Sb based alloy nanostructures have attracted much attention due to their many promising applications, e.g. as battery electrodes, thermoelectric materials and magnetic semiconductors. In many cases, these applications require controlled growth of Sb based alloys with desired sizes and shapes to achieve enhanced performance. Here, we report a flexible catalyst-free chemical vapor deposition (CVD) process to prepare Cu-Sb nanostructures with tunable shapes (e.g. nanowires and nanoparticles) by transporting Sb vapor to react with copper foils, which also serve as the substrate. By simply controlling the substrate temperature and distance, various Sb-Cu alloy nanostructures, e.g. Cu11Sb3 nanowires (NWs), Cu2Sb nanoparticles (NPs), or pure Sb nanoplates, were obtained. We also found that the growth of Cu11Sb3 NWs in such a catalyst-free CVD process was dependent on the substrate surface roughness. For example, smooth Cu foils could not lead to the growth of Cu11Sb3 nanowires while roughening these smooth Cu foils with rough sand papers could result in the growth of Cu11Sb3 nanowires. The effects of gas flow rate on the size and morphology of the Cu-Sb alloy nanostructures were also investigated. Such a flexible growth strategy could be of practical interest as the growth of some Sb based alloy nanostructures by CVD may not be easy due to the large difference between the condensation temperature of Sb and the other element, e.g. Cu or Co.

  14. Laser velocimetry measurements in non-isothermal CVD systems

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

    Researchers at the NASA Langley Research Center are applying laser velocimetry (LV) techniques to characterize the fluid dynamics of non-isothermal flows inside fused silica chambers designed for chemical vapor deposition (CVD). Experimental issues involved in the application of LV techniques to this task include thermophoretic effects on the LV seed particles, seeding the hazardous gases, index of refraction gradients in the flow field and surrounding media, optical access, relatively low flow velocities, and analysis and presentation of sparse data. An overview of the practical difficulties these issues represent to the use of laser velocimetry instrumentation for CVD applications is given. A fundamental limitation on the application of LV techniques in non-isothermal systems is addressed which involves a measurement bias due to the presence of thermal gradients. This bias results from thermophoretic effects which cause seed particle trajectories to deviate from gas streamlines. Data from a research CVD reactor are presented which indicate that current models for the interaction of forces such as Stokes drag, inertia, gravity, and thermophoresis are not adequate to predict thermophoretic effects on particle-based velocimetry measurements in arbitrary flow configurations.

  15. Engineered CVD Diamond Coatings for Machining and Tribological Applications

    NASA Astrophysics Data System (ADS)

    Dumpala, Ravikumar; Chandran, Maneesh; Ramachandra Rao, M. S.

    2015-07-01

    Diamond is an allotropes of carbon and is unique because of its extreme hardness (~100 GPa), low friction coefficient (<0.05), high thermal conductivity (~2000 Wm-1 K-1), and high chemical inertness. Diamond is being synthesized artificially in bulk form as well as in the form of surface coatings for various engineering applications. The mechanical characteristics of chemical vapor deposited (CVD) diamond coatings such as hardness, adhesion, friction coefficient, and fracture toughness can be tuned by controlling the grain size of the coatings from a few microns to a few nanometers. In this review, characteristics and performance of the CVD diamond coatings deposited on cemented tungsten carbide (WC-Co) substrates were discussed with an emphasis on WC-Co grade selection, substrate pretreatment, nanocrystallinity and microcrystallinity of the coating, mechanical and tribological characteristics, coating architecture, and interfacial adhesion integrity. Engineered coating substrate architecture is essential for CVD diamond coatings to perform well under harsh and highly abrasive machining and tribological conditions.

  16. Investigation of the Millimeter-Wave Plasma Assisted CVD Reactor

    SciTech Connect

    Vikharev, A; Gorbachev, A; Kozlov, A; Litvak, A; Bykov, Y; Caplan, M

    2005-07-21

    A polycrystalline diamond grown by the chemical vapor deposition (CVD) technique is recognized as a unique material for high power electronic devices owing to unrivaled combination of properties such as ultra-low microwave absorption, high thermal conductivity, high mechanical strength and chemical stability. Microwave vacuum windows for modern high power sources and transmission lines operating at the megawatt power level require high quality diamond disks with a diameter of several centimeters and a thickness of a few millimeters. The microwave plasma-assisted CVD technique exploited today to produce such disks has low deposition rate, which limits the availability of large size diamond disk windows. High-electron-density plasma generated by the millimeter-wave power was suggested for enhanced-growth-rate CVD. In this paper a general description of the 30 GHz gyrotron-based facility is presented. The output radiation of the gyrotron is converted into four wave-beams. Free localized plasma in the shape of a disk with diameter much larger than the wavelength of the radiation is formed in the intersection area of the wave-beams. The results of investigation of the plasma parameters, as well as the first results of diamond film deposition are presented. The prospects for commercially producing vacuum window diamond disks for high power microwave devices at much lower costs and processing times than currently available are outlined.

  17. Consequences of Obstructive Sleep Apnea: Cardiovascular Risk of Obstructive Sleep Apnea and Whether Continuous Positive Airway Pressure Reduces that Risk.

    PubMed

    Khayat, Rami; Pleister, Adam

    2016-09-01

    Obstructive sleep apnea (OSA) is present in up to 25% of otherwise healthy individuals. OSA is associated with intermittent hypoxia, oxidative stress, sympathetic activation, and an inflammatory response. These perturbations mediate the role of OSA as an independent and modifiable risk factor for cardiovascular disease (CVD). OSA can induce CVD or accelerate the progression of CVD into an end-stage disorder, including heart failure and stroke. Current clinical recommendations are based on existing clinical trial data and the clinical experience of our program; current and future clinical trials will help to optimize management of OSA in the setting of CVD. PMID:27542874

  18. Cardiovascular Disease Risk amongst African Black Patients with Rheumatoid Arthritis: The Need for Population Specific Stratification

    PubMed Central

    Solomon, Ahmed; Tsang, Linda; Woodiwiss, Angela J.; Millen, Aletta M. E.; Norton, Gavin R.; Dessein, Patrick H.

    2014-01-01

    Rheumatoid arthritis (RA) enhances the risk of cardiovascular disease to a similar extent as diabetes. Whereas atherogenesis remains poorly elucidated in RA, traditional and nontraditional risk factors associate similarly and additively with CVD in RA. Current recommendations on CVD risk stratification reportedly have important limitations. Further, reported data on CVD and its risk factors derive mostly from data obtained in the developed world. An earlier epidemiological health transition is intrinsic to persons living in rural areas and those undergoing urbanization. It is therefore conceivable that optimal CVD risk stratification differs amongst patients with RA from developing populations compared to those from developed populations. Herein, we briefly describe current CVD and its risk factor profiles in the African black population at large. Against this background, we review reported data on CVD risk and its potential stratification amongst African black compared to white patients with RA. Routinely assessed traditional and nontraditional CVD risk factors were consistently and independently related to atherosclerosis in African white but not black patients with RA. Circulating concentrations of novel CVD risk biomarkers including interleukin-6 and interleukin-5 adipokines were mostly similarly associated with both endothelial activation and atherosclerosis amongst African black and white RA patients. PMID:25157371

  19. Inequalities, Absolute Value, and Logical Connectives.

    ERIC Educational Resources Information Center

    Parish, Charles R.

    1992-01-01

    Presents an approach to the concept of absolute value that alleviates students' problems with the traditional definition and the use of logical connectives in solving related problems. Uses a model that maps numbers from a horizontal number line to a vertical ray originating from the origin. Provides examples solving absolute value equations and…

  20. Absolute optical metrology : nanometers to kilometers

    NASA Technical Reports Server (NTRS)

    Dubovitsky, Serge; Lay, O. P.; Peters, R. D.; Liebe, C. C.

    2005-01-01

    We provide and overview of the developments in the field of high-accuracy absolute optical metrology with emphasis on space-based applications. Specific work on the Modulation Sideband Technology for Absolute Ranging (MSTAR) sensor is described along with novel applications of the sensor.

  1. Monolithically integrated absolute frequency comb laser system

    DOEpatents

    Wanke, Michael C.

    2016-07-12

    Rather than down-convert optical frequencies, a QCL laser system directly generates a THz frequency comb in a compact monolithically integrated chip that can be locked to an absolute frequency without the need of a frequency-comb synthesizer. The monolithic, absolute frequency comb can provide a THz frequency reference and tool for high-resolution broad band spectroscopy.

  2. Introducing the Mean Absolute Deviation "Effect" Size

    ERIC Educational Resources Information Center

    Gorard, Stephen

    2015-01-01

    This paper revisits the use of effect sizes in the analysis of experimental and similar results, and reminds readers of the relative advantages of the mean absolute deviation as a measure of variation, as opposed to the more complex standard deviation. The mean absolute deviation is easier to use and understand, and more tolerant of extreme…

  3. Investigating Absolute Value: A Real World Application

    ERIC Educational Resources Information Center

    Kidd, Margaret; Pagni, David

    2009-01-01

    Making connections between various representations is important in mathematics. In this article, the authors discuss the numeric, algebraic, and graphical representations of sums of absolute values of linear functions. The initial explanations are accessible to all students who have experience graphing and who understand that absolute value simply…

  4. Absolute Income, Relative Income, and Happiness

    ERIC Educational Resources Information Center

    Ball, Richard; Chernova, Kateryna

    2008-01-01

    This paper uses data from the World Values Survey to investigate how an individual's self-reported happiness is related to (i) the level of her income in absolute terms, and (ii) the level of her income relative to other people in her country. The main findings are that (i) both absolute and relative income are positively and significantly…

  5. Absolute instability of the Gaussian wake profile

    NASA Technical Reports Server (NTRS)

    Hultgren, Lennart S.; Aggarwal, Arun K.

    1987-01-01

    Linear parallel-flow stability theory has been used to investigate the effect of viscosity on the local absolute instability of a family of wake profiles with a Gaussian velocity distribution. The type of local instability, i.e., convective or absolute, is determined by the location of a branch-point singularity with zero group velocity of the complex dispersion relation for the instability waves. The effects of viscosity were found to be weak for values of the wake Reynolds number, based on the center-line velocity defect and the wake half-width, larger than about 400. Absolute instability occurs only for sufficiently large values of the center-line wake defect. The critical value of this parameter increases with decreasing wake Reynolds number, thereby indicating a shrinking region of absolute instability with decreasing wake Reynolds number. If backflow is not allowed, absolute instability does not occur for wake Reynolds numbers smaller than about 38.

  6. Adverse pregnancy outcomes and cardiovascular risk factor management.

    PubMed

    Mehta, Puja K; Minissian, Margo; Bairey Merz, C Noel

    2015-06-01

    Cardiovascular disease (CVD) is the leading health threat to American women. In addition to establish risk factors for hypertension, hyperlipidemia, diabetes, smoking, and obesity, adverse pregnancy outcomes (APOs) including pre-eclampsia, eclampsia, and gestational diabetes are now recognized as factors that increase a woman's risk for future CVD. CVD risk factor burden is disproportionately higher in those of low socioeconomic status and in ethnic/racial minority women. Since younger women often use their obstetrician/gynecologist as their primary health provider, this is an opportune time to diagnose and treat CVD risk factors early. Embedding preventive care providers such as nurse practitioners or physician assistants within OB/GYN practices can be considered, with referral to family medicine or internist for ongoing risk assessment and management. The American Heart Association (AHA)/American Stroke Association (ASA) stroke prevention guidelines tailored to women recommend that women with a history of pre-eclampsia can be evaluated for hypertension and other CVD risk factors within 6 months to 1-year post-partum. Given the burden and impact of CVD on women in our society, the entire medical community must work to establish feasible practice and referral patterns for assessment and treatment of CVD risk factors. PMID:26159741

  7. Adverse Pregnancy Outcomes and Cardiovascular Risk Factor Management

    PubMed Central

    Mehta, Puja K.; Minissian, Margo; Merz, C. Noel Bairey

    2015-01-01

    Cardiovascular disease (CVD) is the leading health threat to American women. In addition to established risk factors for hypertension, hyperlipidemia, diabetes, smoking, and obesity, adverse pregnancy outcomes (APOs) including pre-eclampsia, eclampsia, and gestational diabetes are now recognized as factors that increase a woman’s risk for future CVD. CVD risk factor burden is disproportionately higher in those of low socioeconomic status and in ethnic/racial minority women. Since younger women often use their obstetrician/gynecologist as their primary health provider, this is an opportune time to diagnose and treat CVD risk factors early. Embedding preventive care providers such as nurse practitioners or physician assistants within OB/GYN practices can be considered, with referral to family medicine or internist for ongoing risk assessment and management. The American Heart Association (AHA)/American Stroke Association (ASA) stroke prevention guidelines tailored to women recommend that women with a history of pre-eclampsia be evaluated for hypertension and other CVD risk factors within 6 months to 1 year post-partum. Given the burden and impact of CVD on women our society, the entire medical community must work to establish feasible practice and referral patterns for assessment and treatment of CVD risk factors. PMID:26159741

  8. Fatty acids linked to cardiovascular mortality are associated with risk factors

    PubMed Central

    Ebbesson, Sven O. E.; Voruganti, Venkata S.; Higgins, Paul B.; Fabsitz, Richard R.; Ebbesson, Lars O.; Laston, Sandra; Harris, William S.; Kennish, John; Umans, Benjamin D.; Wang, Hong; Devereux, Richard B.; Okin, Peter M.; Weissman, Neil J.; MacCluer, Jean W.; Umans, Jason G.; Howard, Barbara V.

    2015-01-01

    Background Although saturated fatty acids (FAs) have been linked to cardiovascular mortality, it is not clear whether this outcome is attributable solely to their effects on low-density lipoprotein cholesterol (LDL-C) or whether other risk factors are also associated with FAs. The Western Alaskan Native population, with its rapidly changing lifestyles, shift in diet from unsaturated to saturated fatty acids and dramatic increase in cardiovascular disease (CVD), presents an opportunity to elucidate any associations between specific FAs and known CVD risk factors. Objective We tested the hypothesis that the specific FAs previously identified as related to CVD mortality are also associated with individual CVD risk factors. Methods In this community-based, cross-sectional study, relative proportions of FAs in plasma and red blood cell membranes were compared with CVD risk factors in a sample of 758 men and women aged ≥35 years. Linear regression analyses were used to analyze relations between specific FAs and CVD risk factors (LDL-C, high-density lipoprotein cholesterol, triglycerides, C-reactive protein, systolic blood pressure, diastolic blood pressure, heart rate, body mass index, fasting glucose and fasting insulin, 2-hour glucose and 2-hour insulin). Results The specific saturated FAs previously identified as related to CVD mortality, the palmitic and myristic acids, were adversely associated with most CVD risk factors, whereas unsaturated linoleic acid (18:2n-6) and the marine n-3 FAs were not associated or were beneficially associated with CVD risk factors. Conclusions The results suggest that CVD risk factors are more extensively affected by individual FAs than hitherto recognized, and that risk for CVD, MI and stroke can be reduced by reducing the intake of palmitate, myristic acid and simple carbohydrates and improved by greater intake of linoleic acid and marine n-3 FAs. PMID:26274054

  9. Prevalence of cardiovascular disease risk factors among older Puerto Rican adults living in Massachusetts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There remains limited research on cardiovascular disease (CVD) risk factors in Puerto Rican adults. We compared lifestyle and CVD risk factors in Puerto Rican men and women with normal fasting glucose (NFG), impaired fasting glucose (IFG), or type 2 diabetes (T2D), and investigated achievement of Am...

  10. Absolute optical instruments without spherical symmetry

    NASA Astrophysics Data System (ADS)

    Tyc, Tomáš; Dao, H. L.; Danner, Aaron J.

    2015-11-01

    Until now, the known set of absolute optical instruments has been limited to those containing high levels of symmetry. Here, we demonstrate a method of mathematically constructing refractive index profiles that result in asymmetric absolute optical instruments. The method is based on the analogy between geometrical optics and classical mechanics and employs Lagrangians that separate in Cartesian coordinates. In addition, our method can be used to construct the index profiles of most previously known absolute optical instruments, as well as infinitely many different ones.

  11. Four Years of Absolute Gravity in the Taiwan Orogen (AGTO)

    NASA Astrophysics Data System (ADS)

    Mouyen, Maxime; Masson, Frédéric; Hwang, Cheinway; Cheng, Ching-Chung; Le Moigne, Nicolas; Lee, Chiung-Wu; Kao, Ricky; Hsieh, Nicky

    2010-05-01

    AGTO is a scientific project between Taiwanese and French institutes, which aim is to improve tectonic knowledge of Taiwan primarily using absolute gravity measurements and permanent GPS stations. Both tools are indeed useful to study vertical movements and mass transfers involved in mountain building, a major process in Taiwan located at the convergent margin between Philippine Sea plate and Eurasian plate. This convergence results in two subductions north and south of Taiwan (Ryukyu and Manilla trenches, respectively), while the center is experiencing collision. These processes make Taiwan very active tectonically, as illustrated by numerous large earthquakes and rapid uplift of the Central Range. High slopes of Taiwan mountains and heavy rains brought by typhoons together lead to high landslides and mudflows risks. Practically, absolute gravity measurements have been yearly repeated since 2006 along a transect across south Taiwan, from Penghu to Lutao islands, using FG5 absolute gravimeters. This transect contains ten sites for absolute measurements and has been densified in 2008 by incorporating 45 sites for relative gravity measurements with CG5 gravimeters. The last relative and absolute measurements have been performed in November 2009. Most of the absolute sites have been measured with a good accuracy, about 1 or 2 ?Gal. Only the site located in Tainan University has higher standard deviation, due to the city noise. We note that absolute gravity changes seem to follow a trend in every site. However, straightforward tectonic interpretation of these trends is not valuable as many non-tectonic effects are supposed to change g with time, like groundwater or erosion. Estimating and removing these effects leads to a tectonic gravity signal, which has theoretically two origins : deep mass transfers around the site and vertical movements of the station. The latter can be well constrained by permanent GPS stations located close to the measurement pillar. Deep mass

  12. Four Years of Absolute Gravity in the Taiwan Orogen (AGTO)

    NASA Astrophysics Data System (ADS)

    Mouyen, M.; Masson, F.; Hwang, C.; Cheng, C.; Le Moigne, N.; Lee, C.; Kao, R.; Hsieh, N.

    2009-12-01

    AGTO is a scientific project between Taiwanese and French institutes which aim is to improve tectonic knowledge of Taiwan primarily using absolute gravity measurements and permanent GPS stations. Both tools are indeed useful to study vertical movements and mass transfers involved in mountain building, a major process in Taiwan located at the convergent margin between Philippine Sea plate and Eurasian plate. This convergence results in two subductions north and south of Taiwan (Ryukyu and Manilla trenches, respectively), while the center is experiencing collision. These processes make Taiwan very active tectonically, as illustrated by numerous large earthquakes and rapid uplift of the Central Range. High slopes of Taiwan mountains and heavy rains brought by typhoons together lead to high landslides and mudflows risks. Practically, absolute gravity measurements have been yearly repeated since 2006 along a transect across south Taiwan, from Penghu to Lutao island, using FG5 absolute gravimeters. This transect contains ten sites for absolute measurements and has been densified in 2008 by incorporating 45 sites for relative gravity measurements with CG5 gravimeters. At the end of 2009, the relative gravity network will be densified again in its eastern part, i.e. in the Longitudinal Valley and the Central Range. A fourth set of absolute gravity measurements will also be performed at the same period. Most of the absolute sites have been measured with a good accuracy, about 1 or 2 μGal. Only the site located in Tainan University has higher standard deviation, due to the city noise. The stronger change in gravity reaches -7 μGal a -1 west of the Longitudinal Valley and might be explained by tectonic movement along a fault. A large decrease of -5 μGal a-1 is also measured in Tainan city and could be correlated with uplift of this region, also denoted by InSAR, leveling and GPS. Changes occurring in the Central Range are more difficult to interpret due to the small

  13. 25th anniversary article: CVD polymers: a new paradigm for surface modification and device fabrication.

    PubMed

    Coclite, Anna Maria; Howden, Rachel M; Borrelli, David C; Petruczok, Christy D; Yang, Rong; Yagüe, Jose Luis; Ugur, Asli; Chen, Nan; Lee, Sunghwan; Jo, Won Jun; Liu, Andong; Wang, Xiaoxue; Gleason, Karen K

    2013-10-11

    Well-adhered, conformal, thin (<100 nm) coatings can easily be obtained by chemical vapor deposition (CVD) for a variety of technological applications. Room temperature modification with functional polymers can be achieved on virtually any substrate: organic, inorganic, rigid, flexible, planar, three-dimensional, dense, or porous. In CVD polymerization, the monomer(s) are delivered to the surface through the vapor phase and then undergo simultaneous polymerization and thin film formation. By eliminating the need to dissolve macromolecules, CVD enables insoluble polymers to be coated and prevents solvent damage to the substrate. CVD film growth proceeds from the substrate up, allowing for interfacial engineering, real-time monitoring, and thickness control. Initiated-CVD shows successful results in terms of rationally designed micro- and nanoengineered materials to control molecular interactions at material surfaces. The success of oxidative-CVD is mainly demonstrated for the deposition of organic conducting and semiconducting polymers. PMID:24115244

  14. Cardiovascular diseases in grandparents and the risk of congenital heart diseases in grandchildren.

    PubMed

    Wijnands, K P J; Obermann-Borst, S A; Sijbrands, E J G; Wildhagen, M F; Helbing, W A; Steegers-Theunissen, R P M

    2014-04-01

    Hyperglycemia, dyslipidemia and hyperhomocysteinemia are associated with both adult cardiovascular disease (CVD) and having a child with a congenital heart disease (CHD). We investigated associations between CVD in grandparents and the risk of CHD in grandchildren. In a case-control family study, we obtained detailed questionnaire information on CVD and CHD in 247 families with a CHD child and 203 families without a CHD child. Grandparents with CVD or intermittent claudication (IC) were significantly associated with an increased risk for CHD in grandchildren [OR 1.39 (95% CI 1.03-1.89) and OR 2.77 (95% CI 1.02-7.56), respectively]. The risk of CHD grandchildren was particularly increased in paternal grandfathers with CVD [OR 1.85 (95% CI 1.01-3.37)]. Overall, having a grandparent with CVD increased the risk for CHD in the grandchild by 1.65 (95% CI 1.12-2.41). After adjustment for potential maternal confounders, this risk was 1.44 (95% CI 0.94-2.21). Having two or more grandparents with CVD was associated with an approximately threefold risk for CHD grandchildren [OR adjusted 2.72 (95% CI 1.08-6.89)]. Our data suggest that CVD and IC in grandparents are associated with an increased risk of having a CHD grandchild. These first findings may be explained by shared causality of derangements in metabolic pathways and are in line with the fetal origins of health and disease. PMID:24847701

  15. Controlled CVD growth of Cu-Sb alloy nanostructures.

    PubMed

    Chen, Jing; Yin, Zongyou; Sim, Daohao; Tay, Yee Yan; Zhang, Hua; Ma, Jan; Hng, Huey Hoon; Yan, Qingyu

    2011-08-12

    Sb based alloy nanostructures have attracted much attention due to their many promising applications, e.g. as battery electrodes, thermoelectric materials and magnetic semiconductors. In many cases, these applications require controlled growth of Sb based alloys with desired sizes and shapes to achieve enhanced performance. Here, we report a flexible catalyst-free chemical vapor deposition (CVD) process to prepare Cu-Sb nanostructures with tunable shapes (e.g. nanowires and nanoparticles) by transporting Sb vapor to react with copper foils, which also serve as the substrate. By simply controlling the substrate temperature and distance, various Sb-Cu alloy nanostructures, e.g. Cu(11)Sb(3) nanowires (NWs), Cu(2)Sb nanoparticles (NPs), or pure Sb nanoplates, were obtained. We also found that the growth of Cu(11)Sb(3) NWs in such a catalyst-free CVD process was dependent on the substrate surface roughness. For example, smooth Cu foils could not lead to the growth of Cu(11)Sb(3) nanowires while roughening these smooth Cu foils with rough sand papers could result in the growth of Cu(11)Sb(3) nanowires. The effects of gas flow rate on the size and morphology of the Cu-Sb alloy nanostructures were also investigated. Such a flexible growth strategy could be of practical interest as the growth of some Sb based alloy nanostructures by CVD may not be easy due to the large difference between the condensation temperature of Sb and the other element, e.g. Cu or Co. PMID:21757793

  16. Pathway analysis of body mass index genome-wide association study highlights risk pathways in cardiovascular disease

    PubMed Central

    Zhao, Xin; Gu, Jinxia; Li, Ming; Xi, Jie; Sun, Wenyu; Song, Guangmin; Liu, Guiyou

    2015-01-01

    Cardiovascular disease (CVD) is a class of diseases that involve the heart or blood vessels. It is reported that body mass index (BMI) is risk factor for CVD. Genome-wide association studies (GWAS) have recently provided rapid insights into genetics of CVD and its risk factors. However, the specific mechanisms how BMI influences CVD risk are largely unknown. We think that BMI may influences CVD risk by shared genetic pathways. In order to confirm this view, we conducted a pathway analysis of BMI GWAS, which examined approximately 329,091 single nucleotide polymorphisms from 4763 samples. We identified 31 significant KEGG pathways. There is literature evidence supporting the involvement of GnRH signaling, vascular smooth muscle contraction, dilated cardiomyopathy, Gap junction, Wnt signaling, Calcium signaling and Chemokine signaling in CVD. Collectively, our study supports the potential role of the CVD risk pathways in BMI. BMI may influence CVD risk by the shared genetic pathways. We believe that our results may advance our understanding of BMI mechanisms in CVD. PMID:26264282

  17. Absolute magnitudes of trans-neptunian objects

    NASA Astrophysics Data System (ADS)

    Duffard, R.; Alvarez-candal, A.; Pinilla-Alonso, N.; Ortiz, J. L.; Morales, N.; Santos-Sanz, P.; Thirouin, A.

    2015-10-01

    Accurate measurements of diameters of trans- Neptunian objects are extremely complicated to obtain. Radiomatric techniques applied to thermal measurements can provide good results, but precise absolute magnitudes are needed to constrain diameters and albedos. Our objective is to measure accurate absolute magnitudes for a sample of trans- Neptunian objects, many of which have been observed, and modelled, by the "TNOs are cool" team, one of Herschel Space Observatory key projects grantes with ~ 400 hours of observing time. We observed 56 objects in filters V and R, if possible. These data, along with data available in the literature, was used to obtain phase curves and to measure absolute magnitudes by assuming a linear trend of the phase curves and considering magnitude variability due to rotational light-curve. In total we obtained 234 new magnitudes for the 56 objects, 6 of them with no reported previous measurements. Including the data from the literature we report a total of 109 absolute magnitudes.

  18. A New Gimmick for Assigning Absolute Configuration.

    ERIC Educational Resources Information Center

    Ayorinde, F. O.

    1983-01-01

    A five-step procedure is provided to help students in making the assignment absolute configuration less bothersome. Examples for both single (2-butanol) and multi-chiral carbon (3-chloro-2-butanol) molecules are included. (JN)

  19. Thermal Analysis of Cold Vacuum Drying (CVD) of Spent Nuclear Fuel (SNF)

    SciTech Connect

    PIEPHO, M.G.

    2000-03-23

    The thermal analysis examined transient thermal and chemical behavior of the Multi-Canister Overpack (MCO) container for a broad range of cases that represent the Cold Vacuum Drying (CVD) processes. The cases were defined to consider both normal and off-normal operations at the CVD Facility for an MCO with N Reactor spent fuel. This analysis provides the basis for the MCO thermal behavior at the CVD Facility in support of the safety basis documentation.

  20. Thirty-year risk of cardiovascular disease in senior medical students – based on the StudHeart study

    PubMed Central

    Morawiec, Robert; Janikowski, Kamil

    2016-01-01

    Introduction Long-term risk functions highlight the need of prophylaxis in youth before the first symptoms of cardiovascular disease (CVD) occur. Aim On the basis of data obtained in the StudHeart study, the aim of this report was to evaluate the 30-year risk of CVD based on the risk scale developed by the Framingham Heart Study (FHS). Material and methods Seven hundred and one students aged 22–27 (mean age: 24 ±1.42) from the 5th and 6th year of the medical faculties of the Medical University of Lodz were included in the study. The StudHeart study was based on an anonymous survey comprising 12 questions. Based on the answers the authors evaluated the 30-year risk of CVD in each respondent using an on-line calculator that allows one to evaluate: general CVD risk including coronary death, myocardial infarction, coronary insufficiency, angina, ischemic stroke, hemorrhagic stroke, transient ischemic attack, peripheral artery disease, heart failure and hard CVD risk including coronary death, myocardial infarction and stroke. Results Elevated general 30-year CVD risk occurred in 23.18% of students, while hard CVD risk was elevated in 16.91% of respondents. In both cases elevated risk occurred more often in men (general CVD risk: 43.46% male vs. 8.93% female, p < 0.001 and hard CVD risk: 29.33% male vs. 8.19% female, p < 0.001). Elevation of the risk was mainly caused by overweight, obesity and smoking cigarettes. Conclusions Based on FHS 30-Year CVD risk, elevated risk occurred in almost one-fourth of students. Prophylactic actions should be performed, especially in men. PMID:27516798

  1. 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.

  2. Gravitational and thermal effects in CVD flow and deposition

    NASA Technical Reports Server (NTRS)

    Clark, I. O.; Black, L. R.; Johnson, E. J.; Hyer, P. V.; Gerdes, W. K.; Culotta, P. W.; Jesser, W. A.; Kui, J.

    1992-01-01

    A three-phased approach is used to investigate the transport phenomena occurring in horizontal CVD reactors. The three phases are made up of laser velocimetry experimental investigations, numerical CFD modeling, and metal-organic chemical vapor deposition experimental studies. Laser velocimetry measurements of flow in a horizontal reactor with a cylindrical flow channel and tilted susceptor demonstrate velocity components arising from thermal expansion and buoyancy effects that significantly exceed the velocity components due to the external applied flow. MOCVD of InP and GaAs thin films in a horizontal reactor channel with a rectangular cross section and a tilted susceptor has also been examined.

  3. Selective, pulsed CVD of platinum on microfilament gas sensors

    SciTech Connect

    Manginell, R.P.; Smith, J.H.; Ricco, A.J.; Moreno, D.J.; Hughes, R.C.; Huber, R.J.; Senturia, S.D.

    1996-05-01

    A post-processing, selective micro-chemical vapor deposition (``micro-CVD``) technology for the deposition of catalytic films on surface-micromachined, nitride-passivated polysilicon filaments has been investigated. Atmospheric pressure deposition of Pt on microfilaments was accomplished by thermal decomposition of Pt acetylacetonate; deposition occurs selectively only on those filaments which are electrically heated. Catalyst morphology, characterized by SEM, can be controlled by altering deposition time, filament temperature, and through the use of pulsed heating of the filament during deposition. Morphology plays an important role in determining the sensitivity of these devices when used as combustible gas sensors.

  4. Development of CVD Mullite Coatings for SiC Fibers

    SciTech Connect

    Sarin, V.K.; Varadarajan, S.

    2000-03-15

    A process for depositing CVD mullite coatings on SiC fibers for enhanced oxidation and corrosion, and/or act as an interfacial protective barrier has been developed. Process optimization via systematic investigation of system parameters yielded uniform crystalline mullite coatings on SiC fibers. Structural characterization has allowed for tailoring of coating structure and therefore properties. High temperature oxidation/corrosion testing of the optimized coatings has shown that the coatings remain adherent and protective for extended periods. However, preliminary tests of coated fibers showed considerable degradation in tensile strength.

  5. Facility for continuous CVD coating of ceramic fibers

    NASA Technical Reports Server (NTRS)

    Moore, Arthur W.

    1992-01-01

    An inductively heated CVD furnace of pilot-plant scale, whose hot zone is 150 mm in diameter x 300 mm in length, has been adapted for continuous coating of ceramic yarns. Coatings at very low pressures are possible in this facility due to the fact that the entire apparatus, including yarn feeding and collecting equipment, is under vacuum. SiC yarn has been coated with 0.1-0.2 microns of BN at yarn speeds of 60 cm/min; a 500-m spool; was coated in about 14 hrs. Coating capacity was tripled by adding pulleys to allow three yarn passes through the furnace.

  6. Ultratough CVD single crystal diamond and three dimensional growth thereof

    DOEpatents

    Hemley, Russell J.; Mao, Ho-kwang; Yan, Chih-shiue

    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.

  7. CVD Of Thin Films From Single Organometallic Precursors

    NASA Technical Reports Server (NTRS)

    Hepp, Aloysius F.; Barron, Andrew R.; Power, Michael B.; Macinnes, Andrew N.; Jenkins, Phillip P.

    1996-01-01

    Method of forming thin inorganic films involves chemical vapor deposition (CVD) from single organometallic precursors. No toxic constituents, minimizes impurities, and yields films having substantially uniform crystal structure and composition. Especially suitable for depositing high-quality passivating or buffer layers of GaS on GaAs semiconductor substrates. Also applicable to formation of high-quality films for purposes other than buffering or passivation, and to different materials in which another element from same group in periodic table of elements substituted for all or portion of each element in GaS/GaAs system.

  8. Healing defective CVD-graphene through vapor phase treatment

    NASA Astrophysics Data System (ADS)

    van Lam, Do; Kim, Sang-Min; Cho, Youngji; Kim, Jae-Hyun; Lee, Hak-Joo; Yang, Jun-Mo; Lee, Seung-Mo

    2014-05-01

    Structural defects present on chemical vapor deposition (CVD)-graphene have usually originated from the growth stage and transfer process. They limit the electronic transport properties of graphene and degrade performance of related devices. Here we report that these inherent atomic defects could be selectively healed by a simple vapor phase treatment performed in equipment conventionally used for atomic layer deposition (ALD). The unique chemistry of Al2O3 ALD facilitated selective depositions of AlxOy compounds on the defects, which could be readily probed and visualized using AFM imaging. The healing agent, AlxOy, was observed to bind tightly to the defects and lead to doping of the CVD-graphene, which was reflected in the noticeable improvement in electrical sheet resistance. In contrast with the chemically doped graphene, the ALD-treated graphenes revealed notable long-term stability under environmental conditions. Our approach promises selective healing of defects present in most materials and possibly ensures considerable improvement in electrical and mechanical properties. ALD with a broad spectrum of material selection could be a versatile tool for upgrading properties of materials.Structural defects present on chemical vapor deposition (CVD)-graphene have usually originated from the growth stage and transfer process. They limit the electronic transport properties of graphene and degrade performance of related devices. Here we report that these inherent atomic defects could be selectively healed by a simple vapor phase treatment performed in equipment conventionally used for atomic layer deposition (ALD). The unique chemistry of Al2O3 ALD facilitated selective depositions of AlxOy compounds on the defects, which could be readily probed and visualized using AFM imaging. The healing agent, AlxOy, was observed to bind tightly to the defects and lead to doping of the CVD-graphene, which was reflected in the noticeable improvement in electrical sheet resistance

  9. The Oxidation of CVD Silicon Carbide in Carbon Dioxide

    NASA Technical Reports Server (NTRS)

    Opila, Elizabeth J.; Nguyen, QuynchGiao N.

    1997-01-01

    Chemically-vapor-deposited silicon carbide (CVD SiC) was oxidized in carbon dioxide (CO2) at temperatures of 1200-1400 C for times between 100 and 500 hours at several gas flow rates. Oxidation weight gains were monitored by thermogravimetric analysis (TGA) and were found to be very small and independent of temperature. Possible rate limiting kinetic laws are discussed. Oxidation of SiC by CO2 is negligible compared to the rates measured for other oxidants typically found in combustion environments: oxygen and water vapor.

  10. Paralinear Oxidation of CVD SiC in Water Vapor

    NASA Technical Reports Server (NTRS)

    Opila, Elizabeth J.; Hann, Raiford E., Jr.

    1997-01-01

    The oxidation kinetics of CVD SiC were monitored by thermogravimetric analysis (TGA) in a 50% H2O/50% O2 gas mixture flowing at 4.4 cm/s for temperatures between 1200 and 1400 C. Paralinear weight change kinetics were observed as the water vapor oxidized the SiC and simultaneously volatilized the silica scale. The long-term degradation rate of SiC is determined by the volatility of the silica scale. Rapid SiC surface recession rates were estimated from these data for actual aircraft engine combustor conditions.

  11. ECR Plasma CVD in Different Magnetic Field Configurations

    NASA Astrophysics Data System (ADS)

    Murata, Masayoshi; Uchida, Satoshi; Kishimoto, Kengo; Tanaka, Masayoshi; Komori, Akio; Kawai, Yoshinobu

    1992-05-01

    An electron cyclotron resonance (ECR) plasma is produced with a slotted Lisitano coil, and the axial distribution of the plasma parameters is measured in detail for different magnetic field configurations. It is found that the plasma density in uniform magnetic fields axially decreases more slowly than that in divergent magnetic fields. Furthermore, carbon films are formed by ECR plasma chemical vapor deposition (CVD), and the deposition rate obtained in the uniform magnetic fields is found to be larger than that obtained in the divergent magnetic fields.

  12. An absolute scale for measuring the utility of money

    NASA Astrophysics Data System (ADS)

    Thomas, P. J.

    2010-07-01

    Measurement of the utility of money is essential in the insurance industry, for prioritising public spending schemes and for the evaluation of decisions on protection systems in high-hazard industries. Up to this time, however, there has been no universally agreed measure for the utility of money, with many utility functions being in common use. In this paper, we shall derive a single family of utility functions, which have risk-aversion as the only free parameter. The fact that they return a utility of zero at their low, reference datum, either the utility of no money or of one unit of money, irrespective of the value of risk-aversion used, qualifies them to be regarded as absolute scales for the utility of money. Evidence of validation for the concept will be offered based on inferential measurements of risk-aversion, using diverse measurement data.

  13. CVD-associated non-coding RNA, ANRIL, modulates expression of atherogenic pathways in VSMC

    SciTech Connect

    Congrains, Ada; Kamide, Kei; Katsuya, Tomohiro; Yasuda, Osamu; Oguro, Ryousuke; Yamamoto, Koichi; Ohishi, Mitsuru; Rakugi, Hiromi

    2012-03-23

    Highlights: Black-Right-Pointing-Pointer ANRIL maps in the strongest susceptibility locus for cardiovascular disease. Black-Right-Pointing-Pointer Silencing of ANRIL leads to altered expression of tissue remodeling-related genes. Black-Right-Pointing-Pointer The effects of ANRIL on gene expression are splicing variant specific. Black-Right-Pointing-Pointer ANRIL affects progression of cardiovascular disease by regulating proliferation and apoptosis pathways. -- Abstract: ANRIL is a newly discovered non-coding RNA lying on the strongest genetic susceptibility locus for cardiovascular disease (CVD) in the chromosome 9p21 region. Genome-wide association studies have been linking polymorphisms in this locus with CVD and several other major diseases such as diabetes and cancer. The role of this non-coding RNA in atherosclerosis progression is still poorly understood. In this study, we investigated the implication of ANRIL in the modulation of gene sets directly involved in atherosclerosis. We designed and tested siRNA sequences to selectively target two exons (exon 1 and exon 19) of the transcript and successfully knocked down expression of ANRIL in human aortic vascular smooth muscle cells (HuAoVSMC). We used a pathway-focused RT-PCR array to profile gene expression changes caused by ANRIL knock down. Notably, the genes affected by each of the siRNAs were different, suggesting that different splicing variants of ANRIL might have distinct roles in cell physiology. Our results suggest that ANRIL splicing variants play a role in coordinating tissue remodeling, by modulating the expression of genes involved in cell proliferation, apoptosis, extra-cellular matrix remodeling and inflammatory response to finally impact in the risk of cardiovascular disease and other pathologies.

  14. Transfer of CVD-grown monolayer graphene onto arbitrary substrates.

    PubMed

    Suk, Ji Won; Kitt, Alexander; Magnuson, Carl W; Hao, Yufeng; Ahmed, Samir; An, Jinho; Swan, Anna K; Goldberg, Bennett B; Ruoff, Rodney S

    2011-09-27

    Reproducible dry and wet transfer techniques were developed to improve the transfer of large-area monolayer graphene grown on copper foils by chemical vapor deposition (CVD). The techniques reported here allow transfer onto three different classes of substrates: substrates covered with shallow depressions, perforated substrates, and flat substrates. A novel dry transfer technique was used to make graphene-sealed microchambers without trapping liquid inside. The dry transfer technique utilizes a polydimethylsiloxane frame that attaches to the poly(methyl methacrylate) spun over the graphene film, and the monolayer graphene was transferred onto shallow depressions with 300 nm depth. The improved wet transfer onto perforated substrates with 2.7 μm diameter holes yields 98% coverage of holes covered with continuous films, allowing the ready use of Raman spectroscopy and transmission electron microscopy to study the intrinsic properties of CVD-grown monolayer graphene. Additionally, monolayer graphene transferred onto flat substrates has fewer cracks and tears, as well as lower sheet resistance than previous transfer techniques. Monolayer graphene films transferred onto glass had a sheet resistance of ∼980 Ω/sq and a transmittance of 97.6%. These transfer techniques open up possibilities for the fabrication of various graphene devices with unique configurations and enhanced performance. PMID:21894965

  15. Chemical vapor deposition (CVD) of cubic silicon carbide. Patent Application

    SciTech Connect

    Addamiano, A.

    1985-07-02

    This invention relates to the growth of cubic silicon carbide crystals. More specifically, this invention relates to the growth of cubic silicon carbide by Chemical Vapor Deposition (CVD). One object of the present invention is to provide a novel method for the production of cubic SiC for high temperature electronic devices. Another object of the present invention is to provide a novel method for the production of highly pure, single crystal cubic SiC that is duplicable. Another object of the present invention is to provide a novel method for the production of large-area single-crystal wafers of cubic SiC. These and other objects of the present invention can be achieved by a method for chemical vapor deposition (CVD) of cubic Silicon Carbide (SiC) comprising the steps of etching silicon substrated having one mechanically polished face; depositing a thin buffer layer of cubic SiC formed by reaction between a heated Si substrate and a H2-C3H8 gas mixuture; and depositing SiC on the buffer layer at high temperature using H2+C3HY+SiH4 mixture.

  16. Predicted Variations in Flow Patterns in a Horizontal CVD Reactor

    NASA Technical Reports Server (NTRS)

    Kuczmarski, Maria A.

    1999-01-01

    Expressions in terms of common reactor operating parameters were derived for the ratio of the Grashof number to the Reynolds number, Gr/Re, the ratio of the Grashof to the square of 2 the Reynolds number, Gr/Re(exp 2), and the Rayleigh number, Ra. Values for these numbers were computed for an example horizontal CVD reactor and compared to numerical simulations to gauge their effectiveness as predictors of the presence or absence of transverse and longitudinal rolls in the reactor. Comparisons were made for both argon and hydrogen carrier gases over the pressure range 2- 101 kPa. Reasonable agreement was achieved in most cases when using Gr/Re to predict the presence of transverse rolls and Ra to predict the presence of longitudinal rolls. The ratio Gr/Re(exp 2) did not yield useful predictions regarding the presence of transverse rolls. This comparison showed that the ratio of the Grashof number to the Reynolds number, as well as the Rayleigh number, can be used to predict the presence or absence of transverse and longitudinal rolls in a horizontal CVD reactor for a given set of reactor conditions. These predictions are approximate, and care must be exercised when making predictions near transition regions.

  17. CVD of silicon carbide on structural fibers - Microstructure and composition

    NASA Technical Reports Server (NTRS)

    Veitch, Lisa C.; Terepka, Francis M.; Gokoglu, Suleyman A.

    1992-01-01

    Structural fibers are currently being considered as reinforcements for intermetallic and ceramic materials. Some of these fibers, however, are easily degraded in a high temperature oxidative environment. Therefore, coatings are needed to protect the fibers from environmental attack. Silicon carbide (SiC) was chemically vapor deposited (CVD) on Textron's SCS6 fibers. Fiber temperatures ranging from 1350 to 1500 C were studied. Silane (SiH4) and propane (C2H8) were used for the source gases and different concentrations of these source gases were studied. Deposition rates were determined for each group of fibers at different temperatures. Less variation in deposition rates were observed for the dilute source gas experiments than the concentrated source gas experiments. A careful analysis was performed on the stoichiometry of the CVD SiC coating using electron microprobe. Microstructures for the different conditions were compared. At 1350 C, the microstructures were similar; however, at higher temperatures, the microstructure for the more concentrated source gas group were porous and columnar in comparison to the cross sections taken from the same area for the dilute source gas group.

  18. Thermoluminescence in CVD diamond films: application to actinometric dosimetry.

    PubMed

    Barboza-Flores, M; Meléndrez, R; Chernov, V; Castañeda, B; Pedroza-Montero, M; Gan, B; Ahn, J; Zhang, Q; Yoon, S F

    2002-01-01

    Diamond is considered a tissue-equivalent material since its atomic number (Z =6) is close to the effective atomic number of biological tissue (Z =7.42). Such a situation makes it suitable for radiation detection purposes in medical applications. In the present work the analysis is reported of the thermoluminescence (TL) and dosimetric features of chemically vapour deposited (CVD) diamond film samples subjected to ultraviolet (UV) irradiation in the actinometric region. The TL glow curve shows peaks at 120, 220), 320 and 370 degrees C. The 120 and 370 degrees C peaks are too weak and the first one fades away in a few seconds after exposure. The overall room temperature fading shows a 50% TL decay 30 min after exposure. The 320 degrees C glow peak is considered to be the most adequate for dosimetric applications due to its low fading and linear TL behaviour as a function of UV dose in the 180-260 nm range. The TL excitation spectrum presents a broad band with at least two overlapped components around 205 and 220 nm. The results indicate that the TL behaviour of CVD diamond film can be a good alternative to the currently available dosemeter and detector in the actinometric region as well as in clinical and medical applications. PMID:12382917

  19. Native NIR-emitting single colour centres in CVD diamond

    NASA Astrophysics Data System (ADS)

    Gatto Monticone, D.; Traina, P.; Moreva, E.; Forneris, J.; Olivero, P.; Degiovanni, I. P.; Taccetti, F.; Giuntini, L.; Brida, G.; Amato, G.; Genovese, M.

    2014-05-01

    Single-photon sources are a fundamental element for developing quantum technologies, and sources based on colour centres in diamonds are among the most promising candidates. The well-known nitrogen vacancy centres are characterized by several limitations, and thus few other defects have recently been considered. In the present work, we characterize, in detail, native efficient single colour centres emitting in the near infra-red (λ = 740-780 nm) in both standard IIa single-crystal and electronic-grade polycrystalline commercial chemical vapour deposited (CVD) diamond samples. In the former case, a high-temperature (T > 1000 °C) annealing process in vacuum is necessary to induce the formation/activation of luminescent centres with good emission properties, while in the latter case the annealing process has marginally beneficial effects on the number and performance of native centres in commercially available samples. Although displaying significant variability in several photo-physical properties (emission wavelength, emission rate instabilities, saturation behaviours), these centres generally display appealing photophysical properties for applications as single photon sources: short lifetimes (0.7-3 ns), high emission rates (˜50-500 × 103 photons s-1) and strongly (>95%) polarized light. The native centres are tentatively attributed to impurities incorporated in the diamond crystal during the CVD growth of high-quality type-IIa samples, and offer promising perspectives in diamond-based photonics.

  20. Oxide Dispersion Strengthened Iron Aluminide by CVD Coated Powders

    SciTech Connect

    Asit Biswas Andrew J. Sherman

    2006-09-25

    This I &I Category2 program developed chemical vapor deposition (CVD) of iron, aluminum and aluminum oxide coated iron powders and the availability of high temperature oxidation, corrosion and erosion resistant coating for future power generation equipment and can be used for retrofitting existing fossil-fired power plant equipment. This coating will provide enhanced life and performance of Coal-Fired Boilers components such as fire side corrosion on the outer diameter (OD) of the water wall and superheater tubing as well as on the inner diameter (ID) and OD of larger diameter headers. The program also developed a manufacturing route for readily available thermal spray powders for iron aluminide coating and fabrication of net shape component by powder metallurgy route using this CVD coated powders. This coating can also be applid on jet engine compressor blade and housing, industrial heat treating furnace fixtures, magnetic electronic parts, heating element, piping and tubing for fossil energy application and automotive application, chemical processing equipment , heat exchanger, and structural member of aircraft. The program also resulted in developing a new fabrication route of thermal spray coating and oxide dispersion strengthened (ODS) iron aluminide composites enabling more precise control over material microstructures.

  1. Healing defective CVD-graphene through vapor phase treatment.

    PubMed

    Van Lam, Do; Kim, Sang-Min; Cho, Youngji; Kim, Jae-Hyun; Lee, Hak-Joo; Yang, Jun-Mo; Lee, Seung-Mo

    2014-06-01

    Structural defects present on chemical vapor deposition (CVD)-graphene have usually originated from the growth stage and transfer process. They limit the electronic transport properties of graphene and degrade performance of related devices. Here we report that these inherent atomic defects could be selectively healed by a simple vapor phase treatment performed in equipment conventionally used for atomic layer deposition (ALD). The unique chemistry of Al2O3 ALD facilitated selective depositions of AlxOy compounds on the defects, which could be readily probed and visualized using AFM imaging. The healing agent, AlxOy, was observed to bind tightly to the defects and lead to doping of the CVD-graphene, which was reflected in the noticeable improvement in electrical sheet resistance. In contrast with the chemically doped graphene, the ALD-treated graphenes revealed notable long-term stability under environmental conditions. Our approach promises selective healing of defects present in most materials and possibly ensures considerable improvement in electrical and mechanical properties. ALD with a broad spectrum of material selection could be a versatile tool for upgrading properties of materials. PMID:24756318

  2. CVD of silicon carbide on structural fibers: Microstructure and composition

    NASA Technical Reports Server (NTRS)

    Veitch, Lisa C.; Terepka, Francis M.; Gokoglu, Suleyman A.

    1992-01-01

    Structural fibers are currently being considered as reinforcements for intermetallic and ceramic materials. Some of these fibers, however, are easily degraded in a high temperature oxidative environment. Therefore, coatings are needed to protect the fibers from environmental attack. Silicon carbide (SiC) was chemically vapor deposited (CVD) on Textron's SCS6 fibers. Fiber temperatures ranging from 1350 to 1500 C were studied. Silane (SiH4) and propane (C2H8) were used for the source gases and different concentrations of these source gases were studied. Deposition rates were determined for each group of fibers at different temperatures. Less variation in deposition rates were observed for the dilute source gas experiments than the concentrated source gas experiments. A careful analysis was performed on the stoichiometry of the CVD SiC coating using electron microprobe. Microstructures for the different conditions were compared. At 1350 C, the microstructures were similar; however, at higher temperatures, the microstructure for the more concentrated source gas group were porous and columnar in comparison to the cross sections taken from the same area for the dilute source gas group.

  3. Dopant Incorporation Efficiency in CVD Silicon Carbide Epilayers

    NASA Technical Reports Server (NTRS)

    Larkin, D. J.

    1996-01-01

    In order to ensure reproducible and reliable SiC semiconductor device characteristics, controlled dopant incorporation must be accomplished. Some of the many factors which greatly influence dopant incorporation are the site-competition effect, SiC(0001) substrate polarity, substrate temperature, and the dopant-source reactor concentration. In this paper, dopant incorporation is considered and compared for various dopants in the context of dopant incorporation efficiency. By using secondary ion mass spectrometry (SIMS), the relative dopant incorporation efficiencies were calculated by dividing the SIMS determined dopant concentration in the resulting epitaxial layer by the intentional gas phase dopant concentration used during the SiC CVD. Specifically, the relative magnitudes of dopant incorporation efficiencies for nitrogen, phosphorus, and boron in 6H-SiC (0001) Si-face epitaxial layers are compared as a function of the site-competition effect and the dopant-source reactor concentrations. This serves as a first approximation for comparison of the relative 'doping potencies' of some common dopants used in SiC CVD epitaxial growth.

  4. CVD Rhenium Engines for Solar-Thermal Propulsion Systems

    NASA Technical Reports Server (NTRS)

    Williams, Brian E.; Fortini, Arthur J.; Tuffias, Robert H.; Duffy, Andrew J.; Tucker, Stephen P.

    1999-01-01

    Solar-thermal upper-stage propulsion systems have the potential to provide specific impulse approaching 900 seconds, with 760 seconds already demonstrated in ground testing. Such performance levels offer a 100% increase in payload capability compared to state-of-the-art chemical upper-stage systems, at lower cost. Although alternatives such as electric propulsion offer even greater performance, the 6- to 18- month orbital transfer time is a far greater deviation from the state of the art than the one to two months required for solar propulsion. Rhenium metal is the only material that is capable of withstanding the predicted thermal, mechanical, and chemical environment of a solar-thermal propulsion device. Chemical vapor deposition (CVD) is the most well-established and cost-effective process for the fabrication of complex rhenium structures. CVD rhenium engines have been successfully constructed for the Air Force ISUS program (bimodal thrust/electricity) and the NASA Shooting Star program (thrust only), as well as under an Air Force SBIR project (thrust only). The bimodal engine represents a more long-term and versatile approach to solar-thermal propulsion, while the thrust-only engines provide a potentially lower weight/lower cost and more near-term replacement for current upper-stage propulsion systems.

  5. Crystallographic anisotropy of growth and etch rates of CVD diamond

    SciTech Connect

    Wolfer, M; Biener, J; El-dasher, B S; Biener, M M; Hamza, A V; Kriele, A; Wild, C

    2008-08-05

    The investigation of orientation dependent crystal growth and etch processes can provide deep insights into the underlying mechanisms and thus helps to validate theoretical models. Here, we report on homoepitaxial diamond growth and oxygen etch experiments on polished, polycrystalline CVD diamond wafers by use of electron backscatter diffraction (EBSD) and white-light interferometry (WLI). Atomic force microscopy (AFM) was applied to provide additional atomic scale surface morphology information. The main advantage of using polycrystalline diamond substrates with almost random grain orientation is that it allows determining the orientation dependent growth (etch) rate for different orientations within one experiment. Specifically, we studied the effect of methane concentration on the diamond growth rate, using a microwave plasma CVD process. At 1 % methane concentration a maximum of the growth rate near <100> and a minimum near <111> is detected. Increasing the methane concentration up to 5 % shifts the maximum towards <110> while the minimum stays at <111>. Etch rate measurements in a microwave powered oxygen plasma reveal a pronounced maximum at <111>. We also made a first attempt to interpret our experimental data in terms of local micro-faceting of high-indexed planes.

  6. Jasminum flexile flower absolute from India--a detailed comparison with three other jasmine absolutes.

    PubMed

    Braun, Norbert A; Kohlenberg, Birgit; Sim, Sherina; Meier, Manfred; Hammerschmidt, Franz-Josef

    2009-09-01

    Jasminum flexile flower absolute from the south of India and the corresponding vacuum headspace (VHS) sample of the absolute were analyzed using GC and GC-MS. Three other commercially available Indian jasmine absolutes from the species: J. sambac, J. officinale subsp. grandiflorum, and J. auriculatum and the respective VHS samples were used for comparison purposes. One hundred and twenty-one compounds were characterized in J. flexile flower absolute, with methyl linolate, benzyl salicylate, benzyl benzoate, (2E,6E)-farnesol, and benzyl acetate as the main constituents. A detailed olfactory evaluation was also performed. PMID:19831037

  7. A Path Analysis of a Randomized "Promotora de Salud" Cardiovascular Disease-Prevention Trial among At-Risk Hispanic Adults

    ERIC Educational Resources Information Center

    de Heer, Hendrik Dirk; Balcazar, Hector G.; Castro, Felipe; Schulz, Leslie

    2012-01-01

    This study assessed effectiveness of an educational community intervention taught by "promotoras de salud" in reducing cardiovascular disease (CVD) risk among Hispanics using a structural equation modeling (SEM) approach. Model development was guided by a social ecological framework proposing CVD risk reduction through improvement of protective…

  8. Risk.

    PubMed

    Cole, Stephen R; Hudgens, Michael G; Brookhart, M Alan; Westreich, Daniel

    2015-02-15

    The epidemiologist primarily studies transitions between states of health and disease. The purpose of the present article is to define a foundational parameter for such studies, namely risk. We begin simply and build to the setting in which there is more than 1 event type (i.e., competing risks or competing events), as well as more than 1 treatment or exposure level of interest. In the presence of competing events, the risks are a set of counterfactual cumulative incidence functions for each treatment. These risks can be depicted visually and summarized numerically. We use an example from the study of human immunodeficiency virus to illustrate concepts. PMID:25660080

  9. Novel risk factors for cardiovascular disease in rheumatoid arthritis.

    PubMed

    Amaya-Amaya, Jenny; Sarmiento-Monroy, Juan Camilo; Mantilla, Ruben-Dario; Pineda-Tamayo, Ricardo; Rojas-Villarraga, Adriana; Anaya, Juan-Manuel

    2013-07-01

    Since cardiovascular disease (CVD) is the most common cause of mortality in patients with rheumatoid arthritis (RA), we aimed to determine factors associated with such a complication in a large series of Colombian patients. This was a cross-sectional analytical study in which 800 consecutive Colombian patients with RA were assessed for variables associated with CVD. Furthermore, a systematic literature review was performed to address the state of the art about non-traditional risk factors for CVD in RA. The preferred reporting items for systematic reviews and meta-analyses guidelines were followed in data extraction, analysis, and reporting of articles selected. Hypercholesterolemia, type 2 diabetes mellitus, abnormal body mass index, abdominal obesity, and current smoking were all traditional risk factors significantly associated with CVD in Colombians. As non-traditional risk factors, familial autoimmunity, more than 10 years of duration of the disease, patients working on household duties, use of systemic steroids, and low education level were associated with CVD in the studied population. Out of a total of 9,812 articles identified in PubMed and Scopus databases, 140 fulfilled the eligibility criteria and were included. Through this systematic review, several factors and outcomes related to CVD were confirmed and identified. These were categorized into genetics, RA-related, and others. Traditional risk factors do not completely explain the high rates of CVD in patients with RA; thus, novel risk factors related to autoimmunity are now recognized predicting the presence of CVD as strong as traditional risk factors. Our results may assist health professionals and policymakers in making decisions about CVD in patients with RA. PMID:23584985

  10. Universal Cosmic Absolute and Modern Science

    NASA Astrophysics Data System (ADS)

    Kostro, Ludwik

    The official Sciences, especially all natural sciences, respect in their researches the principle of methodic naturalism i.e. they consider all phenomena as entirely natural and therefore in their scientific explanations they do never adduce or cite supernatural entities and forces. The purpose of this paper is to show that Modern Science has its own self-existent, self-acting, and self-sufficient Natural All-in Being or Omni-Being i.e. the entire Nature as a Whole that justifies the scientific methodic naturalism. Since this Natural All-in Being is one and only It should be considered as the own scientifically justified Natural Absolute of Science and should be called, in my opinion, the Universal Cosmic Absolute of Modern Science. It will be also shown that the Universal Cosmic Absolute is ontologically enormously stratified and is in its ultimate i.e. in its most fundamental stratum trans-reistic and trans-personal. It means that in its basic stratum. It is neither a Thing or a Person although It contains in Itself all things and persons with all other sentient and conscious individuals as well, On the turn of the 20th century the Science has begun to look for a theory of everything, for a final theory, for a master theory. In my opinion the natural Universal Cosmic Absolute will constitute in such a theory the radical all penetrating Ultimate Basic Reality and will substitute step by step the traditional supernatural personal Absolute.

  11. Absolute isotopic abundances of TI in meteorites

    NASA Astrophysics Data System (ADS)

    Niederer, F. R.; Papanastassiou, D. A.; Wasserburg, G. J.

    1985-03-01

    The absolute isotope abundance of Ti has been determined in Ca-Al-rich inclusions from the Allende and Leoville meteorites and in samples of whole meteorites. The absolute Ti isotope abundances differ by a significant mass dependent isotope fractionation transformation from the previously reported abundances, which were normalized for fractionation using 46Ti/48Ti. Therefore, the absolute compositions define distinct nucleosynthetic components from those previously identified or reflect the existence of significant mass dependent isotope fractionation in nature. The authors provide a general formalism for determining the possible isotope compositions of the exotic Ti from the measured composition, for different values of isotope fractionation in nature and for different mixing ratios of the exotic and normal components.

  12. Molecular iodine absolute frequencies. Final report

    SciTech Connect

    Sansonetti, C.J.

    1990-06-25

    Fifty specified lines of {sup 127}I{sub 2} were studied by Doppler-free frequency modulation spectroscopy. For each line the classification of the molecular transition was determined, hyperfine components were identified, and one well-resolved component was selected for precise determination of its absolute frequency. In 3 cases, a nearby alternate line was selected for measurement because no well-resolved component was found for the specified line. Absolute frequency determinations were made with an estimated uncertainty of 1.1 MHz by locking a dye laser to the selected hyperfine component and measuring its wave number with a high-precision Fabry-Perot wavemeter. For each line results of the absolute measurement, the line classification, and a Doppler-free spectrum are given.

  13. Stimulus probability effects in absolute identification.

    PubMed

    Kent, Christopher; Lamberts, Koen

    2016-05-01

    This study investigated the effect of stimulus presentation probability on accuracy and response times in an absolute identification task. Three schedules of presentation were used to investigate the interaction between presentation probability and stimulus position within the set. Data from individual participants indicated strong effects of presentation probability on both proportion correct and response times. The effects were moderated by the ubiquitous stimulus position effect. The accuracy and response time data were predicted by an exemplar-based model of perceptual cognition (Kent & Lamberts, 2005). The bow in discriminability was also attenuated when presentation probability for middle items was relatively high, an effect that will constrain future model development. The study provides evidence for item-specific learning in absolute identification. Implications for other theories of absolute identification are discussed. (PsycINFO Database Record PMID:26478959

  14. Absolute calibration in vivo measurement systems

    SciTech Connect

    Kruchten, D.A.; Hickman, D.P.

    1991-02-01

    Lawrence Livermore National Laboratory (LLNL) is currently investigating a new method for obtaining absolute calibration factors for radiation measurement systems used to measure internally deposited radionuclides in vivo. Absolute calibration of in vivo measurement systems will eliminate the need to generate a series of human surrogate structures (i.e., phantoms) for calibrating in vivo measurement systems. The absolute calibration of in vivo measurement systems utilizes magnetic resonance imaging (MRI) to define physiological structure, size, and composition. The MRI image provides a digitized representation of the physiological structure, which allows for any mathematical distribution of radionuclides within the body. Using Monte Carlo transport codes, the emission spectrum from the body is predicted. The in vivo measurement equipment is calibrated using the Monte Carlo code and adjusting for the intrinsic properties of the detection system. The calibration factors are verified using measurements of existing phantoms and previously obtained measurements of human volunteers. 8 refs.

  15. Combined single-crystalline and polycrystalline CVD diamond substrates for diamond electronics

    SciTech Connect

    Vikharev, A. L. Gorbachev, A. M.; Dukhnovsky, M. P.; Muchnikov, A. B.; Ratnikova, A. K.; Fedorov, Yu. Yu.

    2012-02-15

    The fabrication of diamond substrates in which single-crystalline and polycrystalline CVD diamond form a single wafer, and the epitaxial growth of diamond films on such combined substrates containing polycrystalline and (100) single-crystalline CVD diamond regions are studied.

  16. AN INCREASE IN RISK FACTORS FOR CARDIOVASCULAR DISEASE IN YOGYAKARTA, INDONESIA: A COMPARISON OF TWO CROSS-SECTIONAL SURVEYS.

    PubMed

    Dewi, F S T; Stenlund, H; Hakimi, M; Weinehall, L

    2015-07-01

    This paper aims to describe changes in risk factors for cardiovascular disease (CVD) over a five year period in urban Indonesia. In 2004 (n = 3,205) and 2009 (n = 2,467) we conducted cross-sectional surveys of residents in Yogjakarta City, Indonesia evaluating risk factors for CVD. Smoking habits, fruit and vegetable intake, physical activity, blood pressure, weight, and height were recorded. The results of these 2 surveys conducted 5 years apart were then compared. The risk for having a CVD event was also calculated. Behavioral CVD risk factors were more common among men. The predicted risk of having a CVD event increased from 8.4% to 11.3% among men between 2004 and 2009. Effective measures need to be taken to change these behaviors among men in Yogyakarta, Indonesia. PMID:26867398

  17. Precise Measurement of the Absolute Fluorescence Yield

    NASA Astrophysics Data System (ADS)

    Ave, M.; Bohacova, M.; Daumiller, K.; Di Carlo, P.; di Giulio, C.; San Luis, P. Facal; Gonzales, D.; Hojvat, C.; Hörandel, J. R.; Hrabovsky, M.; Iarlori, M.; Keilhauer, B.; Klages, H.; Kleifges, M.; Kuehn, F.; Monasor, M.; Nozka, L.; Palatka, M.; Petrera, S.; Privitera, P.; Ridky, J.; Rizi, V.; D'Orfeuil, B. Rouille; Salamida, F.; Schovanek, P.; Smida, R.; Spinka, H.; Ulrich, A.; Verzi, V.; Williams, C.

    2011-09-01

    We present preliminary results of the absolute yield of fluorescence emission in atmospheric gases. Measurements were performed at the Fermilab Test Beam Facility with a variety of beam particles and gases. Absolute calibration of the fluorescence yield to 5% level was achieved by comparison with two known light sources--the Cherenkov light emitted by the beam particles, and a calibrated nitrogen laser. The uncertainty of the energy scale of current Ultra-High Energy Cosmic Rays experiments will be significantly improved by the AIRFLY measurement.

  18. A food pattern predicting prospective weight change is associated with risk of fatal but not with nonfatal cardiovascular disease.

    PubMed

    Drogan, Dagmar; Hoffmann, Kurt; Schulz, Mandy; Bergmann, Manuela M; Boeing, Heiner; Weikert, Cornelia

    2007-08-01

    Recently, a food pattern predictive for prospective weight change was identified within the European Prospective Investigation into Cancer and Nutrition-Potsdam cohort. Given the possible impact of weight change on cardiovascular disease (CVD) risk, we examined the association between the above mentioned food pattern and risk of CVD. The analyzed food pattern was defined by a high consumption of whole-grain bread, fruits, fruit juices, grain flakes and/or cereals, and raw vegetables, and a low consumption of processed meat, butter, high-fat cheese, margarine, and meat other than poultry. The associations between quartiles of the food pattern score and CVD morbidity and mortality were examined in 26,238 subjects of the European Prospective Investigation into Cancer and Nutrition-Potsdam cohort using a Cox's Proportional Hazards model for competing risks. During 6.4 y of follow-up, 379 incident cases of CVD were identified, of which 68 were fatal events. The food pattern was not associated with risk of nonfatal CVD. After adjusting for cardiovascular risk factors, the hazard ratios for fatal CVD across increasing quartiles of the score were 1.00, 0.85, 0.31, and 0.47, respectively (P for trend = 0.016). The association of the food pattern with CVD risk differed between fatal and nonfatal events (P for difference = 0.05). These findings from a large German cohort indicate that a food pattern predicting prospective weight change may be associated with the risk of fatal CVD. PMID:17634271

  19. Absolutely relative or relatively absolute: violations of value invariance in human decision making.

    PubMed

    Teodorescu, Andrei R; Moran, Rani; Usher, Marius

    2016-02-01

    Making decisions based on relative rather than absolute information processing is tied to choice optimality via the accumulation of evidence differences and to canonical neural processing via accumulation of evidence ratios. These theoretical frameworks predict invariance of decision latencies to absolute intensities that maintain differences and ratios, respectively. While information about the absolute values of the choice alternatives is not necessary for choosing the best alternative, it may nevertheless hold valuable information about the context of the decision. To test the sensitivity of human decision making to absolute values, we manipulated the intensities of brightness stimuli pairs while preserving either their differences or their ratios. Although asked to choose the brighter alternative relative to the other, participants responded faster to higher absolute values. Thus, our results provide empirical evidence for human sensitivity to task irrelevant absolute values indicating a hard-wired mechanism that precedes executive control. Computational investigations of several modelling architectures reveal two alternative accounts for this phenomenon, which combine absolute and relative processing. One account involves accumulation of differences with activation dependent processing noise and the other emerges from accumulation of absolute values subject to the temporal dynamics of lateral inhibition. The potential adaptive role of such choice mechanisms is discussed. PMID:26022836

  20. Oxidation behavior of CVD and single crystal SiC at 1100 C

    SciTech Connect

    Ramberg, C.E.; Spear, K.E.; Tressler, R.E.; Chinone, Yoshiharu

    1995-11-01

    High purity chemical vapor deposition (CVD) silicon carbide fabricated by a commercial process was examined and oxidized at 1,100 C along with high purity single crystal silicon carbide. The freestanding CVD thick films had a highly textured polycrystalline microstructure, with the <111> directions of the crystals parallel to the growth direction. This texturing maintained the polarity of the 43m crystal structure, implying that either the [111] or the [1{und 1}1] direction grew significantly faster during the CVD process. The (111) face of the cubic, CVD-SiC oxidized at the same rate as the (0001) face of the single crystal SiC. The (111) face of the CVD-SiC oxidized at nominally the same rat as the (0001) face of the single crystal SiC.

  1. CHILDHOOD ADVERSITY AND PUBERTAL TIMING: UNDERSTANDING THE ORIGINS OF ADULTHOOD CARDIOVASCULAR RISK

    PubMed Central

    Bleil, Maria E.; Adler, Nancy E.; Appelhans, Bradley M.; Gregorich, Steven E.; Sternfeld, Barbara; Cedars, Marcelle I.

    2013-01-01

    Objective To determine whether greater childhood adversity relates to younger menarcheal age; whether younger menarcheal age relates to increased CVD risk; and whether greater childhood adversity relates to increased CVD risk, directly or indirectly (mediated by menarcheal age). Methods Among 650 pre-menopausal women (ages 25-45; M=34.9[5.6]), SEM was performed to estimate relations between childhood adversity, menarcheal age, and CVD risk. Results Results supported a covariate-adjusted model (RMSEA=0.035; CFI=0.983) in which greater childhood adversity was related to younger menarcheal age (β=−.13, p<.01) and younger menarcheal age was related to greater CVD risk (β=−.18, p<.05). Direct and indirect effects of childhood adversity on CVD risk were non-significant. Re-evaluation of the same model with additional covariate-adjustment for adulthood body composition showed the relation between menarcheal age and CVD risk attenuated (β=−.03, p=.376). Conclusions Cross-sectional evidence suggests family-related adversity experiences in childhood confer risk for earlier menarche which, in turn, relates to increased CVD risk in adulthood, possibly via post-pubertal body size. PMID:23428374

  2. No Absolutism Here: Harm Predicts Moral Judgment 30× Better Than Disgust-Commentary on Scott, Inbar, & Rozin (2016).

    PubMed

    Gray, Kurt; Schein, Chelsea

    2016-05-01

    Moral absolutism is the idea that people's moral judgments are insensitive to considerations of harm. Scott, Inbar, and Rozin (2016, this issue) claim that most moral opponents to genetically modified organisms are absolutely opposed-motivated by disgust and not harm. Yet there is no evidence for moral absolutism in their data. Perceived risk/harm is the most significant predictor of moral judgments for "absolutists," accounting for 30 times more variance than disgust. Reanalyses suggest that disgust is not even a significant predictor of the moral judgments of absolutists once accounting for perceived harm and anger. Instead of revealing actual moral absolutism, Scott et al. find only empty absolutism: hypothetical, forecasted, self-reported moral absolutism. Strikingly, the moral judgments of so-called absolutists are somewhat more sensitive to consequentialist concerns than those of nonabsolutists. Mediation reanalyses reveal that moral judgments are most proximally predicted by harm and not disgust, consistent with dyadic morality. PMID:27217244

  3. Study of magnetotransport across the neutrality point in CVD graphene

    NASA Astrophysics Data System (ADS)

    Mani, Ramesh G.

    Hall effect compensation and a residual resistivity ρxx ~ h / 4e2 are experimentally examined over the p <-->n transition about the nominal Dirac point in CVD graphene. The observed characteristics are reproduced in a model with a parabolic distribution f (VN) of neutrality potentials, VN, and simultaneous electron- and hole- conduction. The results suggest that, broadly about the gate-induced n <--> p transition, charge transport is characterized by domain confined ambipolar currents, which leads to compensation in the global Hall effect and the observed residual resistivity. DOE-BES, Mat'l. Sci. & Eng. Div., DE-SC0001762; ARO W911NF-14-2-0076; ARO W911NF-15-1-0433.

  4. Thermal stability of CVD-SiC lightweight optics

    NASA Astrophysics Data System (ADS)

    Goela, Jitendra S.; Desai, Hemant D.; Taylor, Raymond L.; Olson, Steven E.

    1995-10-01

    The lightweight SiC mirrors that are fabricated by the CVD process at Morton Advanced Materials contain graphite core enclosed in the SiC backstructure. A finite element analysis of a lightweight SiC model mirror was performed to assess the effect of the graphite core on the thermal stability of the SiC mirror in the temperature range of 77 - 1623 K. The results indicate that for both no-slip (SiC deposit adhered to graphite core) and slip cases, the maximum stresses in the SiC mirror structure are significantly less than the flexural strength of SiC. Further, the maximum stress in graphite core is close to the tensile strength of graphite indicating that graphite core will probably fracture. Finally, the SiC faceplate figure distortion due to the presence of the graphite core is quite small, on the order of a few tens of nanometers.

  5. Tip-based patterning of HOPG and CVD graphene

    NASA Astrophysics Data System (ADS)

    Hicks, Bryan T.; Yoshimizu, Norimasa; O'Connell, Christopher; Lal, Amit; Pollock, Clifford R.

    2011-06-01

    Nanometer-scale patterning of graphite and graphene has been accomplished through local anodic oxidation using an AFM tip. The underlying mechanism is explained. To date, protrusions, holes, trenches, and even words have been patterned in HOPG over scales ranging from 1nm2 to 1mm2 and depths ranging from sub nm to as deep as 200nm with less than 5 nm variation on the feature size and placement. This same method has also been applied to CVD-grown graphene providing a resist-free process for patterning graphene at the single nanometer scale. This capability could provide a method to rival e-beam lithography resolution but without any pre- or post-processing.

  6. Electronic and Atomic-Scale Properties of Ultraflat CVD Graphene

    NASA Astrophysics Data System (ADS)

    Gutierrez, Christopher; Rosenthal, Ethan; Dadgar, Ali; Brown, Lola; Lochocki, Edward; Shen, Kyle; Park, Jiwoong; Pasupathy, Abhay

    2014-03-01

    Chemical vapor deposition (CVD) growth on copper foils has proven to be a reliable and cost-effective method for the production of graphene. However, most films grown by this method suffer from misoriented graphene grains as well as topographic roughness due to the polycrystallinity of the underlying copper foil substrate. Recent methods of copper foil treatment have allowed for the growth of graphene predominantly on large single crystal Cu(111) facets. In this talk we discuss scanning tunneling microscope (STM) measurements on such samples that reveal large terraces and atomically-resolved images that allow us to analyze the graphene-copper interaction during the growth. Scanning tunneling spectroscopy (STS) measurements and mapping are further employed to probe the electronic interaction between the graphene and copper substrate.

  7. Dimensionless Numbers Expressed in Terms of Common CVD Process Parameters

    NASA Technical Reports Server (NTRS)

    Kuczmarski, Maria A.

    1999-01-01

    A variety of dimensionless numbers related to momentum and heat transfer are useful in Chemical Vapor Deposition (CVD) analysis. These numbers are not traditionally calculated by directly using reactor operating parameters, such as temperature and pressure. In this paper, these numbers have been expressed in a form that explicitly shows their dependence upon the carrier gas, reactor geometry, and reactor operation conditions. These expressions were derived for both monatomic and diatomic gases using estimation techniques for viscosity, thermal conductivity, and heat capacity. Values calculated from these expressions compared well to previously published values. These expressions provide a relatively quick method for predicting changes in the flow patterns resulting from changes in the reactor operating conditions.

  8. Hydrogen and hydrogen-related defects in CVD diamond

    SciTech Connect

    Rutledge, K.M.M.

    1998-12-31

    Hydrogen is a detrimental impurity in many chemical vapor deposited (CVD) materials, particularly those involved in electronic or optical applications. For example, active hydrogen defects have been observed in materials such as silicon, Si, gallium arsenide, GaAs, and diamond, C, thin films. Hydrogen and its related defects can be identified, quantified, and observed using magnetic resonance techniques. These techniques allow a unique quantitative, non-destructive view of hydrogen in the solid-state. Nuclear magnetic resonance (NMR) is used to study hydrogenated defects directly, while electron paramagnetic resonance (EPR) is used to observe hydrogen associated with paramagnetic defects. These observations can enhance understanding of the effects of hydrogen incorporation on the properties of such materials.

  9. Interfaces in nano-/microcrystalline multigrade CVD diamond coatings.

    PubMed

    Almeida, Flávia A; Salgueiredo, Ermelinda; Oliveira, Filipe J; Silva, Rui F; Baptista, Daniel L; Peripolli, Suzana B; Achete, Carlos A

    2013-11-27

    The interfaces of multilayered CVD diamond films grown by the hot-filament technique were characterized with high detail using HRTEM, STEM-EDX, and EELS. The results show that at the transition from micro- (MCD) to nanocrystalline diamond (NCD), a thin precursor graphitic film is formed, irrespectively of the NCD gas chemistry used (with or without argon). On the contrary, the transition of the NCD to MCD grade is free of carbon structures other than diamond, the result of a higher substrate temperature and more abundant atomic H in the gas chemistry. At those transitions WC nanoparticles could be found due to contamination from the filament, being also present at the first interface of the MCD layer with the silicon nitride substrate. PMID:24164667

  10. Tests of Hercules/Ultramet CVD coatings in hot hydrogen

    SciTech Connect

    Vanier, P.E.; Barletta, R.E.; Svandrlik, J.; Adams, J.

    1992-12-31

    The effort by Hercules and Ultramet to produce CVD NbC coatings, which protect carbon-carbon substrates from hot hydrogen, has had some success but with some limitations. The coatings increase the survival time at atmospheric pressure and low flow rate of hydrogen by about a factor of 40 over uncoated graphite at 3000 K. However, the grain structure is not stable at these temperatures, and after about 10--20 minutes, the coating is subject to rapid degradation by spalling in visible chunks. Further experiments would have to be performed to determine the effects of higher pressures and flow rates, for it is not clear how these factors would affect the survival time, considering that one of the main failure mechanisms is independent of the atmosphere.

  11. Tests of Hercules/Ultramet CVD coatings in hot hydrogen

    SciTech Connect

    Vanier, P.E.; Barletta, R.E.; Svandrlik, J.; Adams, J.

    1992-01-01

    The effort by Hercules and Ultramet to produce CVD NbC coatings, which protect carbon-carbon substrates from hot hydrogen, has had some success but with some limitations. The coatings increase the survival time at atmospheric pressure and low flow rate of hydrogen by about a factor of 40 over uncoated graphite at 3000 K. However, the grain structure is not stable at these temperatures, and after about 10--20 minutes, the coating is subject to rapid degradation by spalling in visible chunks. Further experiments would have to be performed to determine the effects of higher pressures and flow rates, for it is not clear how these factors would affect the survival time, considering that one of the main failure mechanisms is independent of the atmosphere.

  12. ECR Plasma CVD Using a Slotted Lisitano Coil

    NASA Astrophysics Data System (ADS)

    Kawai, Yoshinobu; Komori, Akio; Ikeda, Hidehiko; Kishimoto, Kengo; Murata, Masayoshi; Uchida, Satoshi

    1990-11-01

    An ECR plasma is produced at relatively high pressures up to 25 mTorr with a slotted Lisitano coil 140 mm in diameter, and the radial distributions of plasma parameters are measured. It is found that the plasma is almost radially uniform even at pressures higher than 10 mTorr. Carbon films are formed on silicon wafers by introducing methane gas into the ECR plasma and the deposition rate is examined as a function of concentration of methane gas and substrate temperature. Furthermore, the physical properties of the films are analyzed by X-ray diffraction and Raman scattering. These results show that a slotted Lisitano coil is very useful for the ECR plasma CVD.

  13. Leakage current measurements of a pixelated polycrystalline CVD diamond detector

    NASA Astrophysics Data System (ADS)

    Zain, R. M.; Maneuski, D.; O'Shea, V.; Bates, R.; Blue, A.; Cunnigham, L.; Stehl, C.; Berderman, E.; Rahim, R. A.

    2013-01-01

    Diamond has several desirable features when used as a material for radiation detection. With the invention of synthetic growth techniques, it has become feasible to look at developing diamond radiation detectors with reasonable surface areas. Polycrystalline diamond has been grown using a chemical vapour deposition (CVD) technique by the University of Augsburg and detector structures fabricated at the James Watt Nanofabrication Centre (JWNC) in the University of Glasgow in order to produce pixelated detector arrays. The anode and cathode contacts are realised by depositing gold to produce ohmic contacts. Measurements of I-V characteristics were performed to study the material uniformity. The bias voltage is stepped from -1000V to 1000V to investigate the variation of leakage current from pixel to pixel. Bulk leakage current is measured to be less than 1nA.

  14. Textures and morphologies of chemical vapor deposited (CVD) diamond

    SciTech Connect

    Clausing, R.E.; Heatherly, L.; Horton, L.L.; Specht, E.D.; Begun, G.M. ); Wang, Z.L. )

    1991-01-01

    The textures, surface morphologies, structural perfection, and properties of diamond films grown by activated chemical vapor deposition (CVD) vary greatly with the growth conditions. The evolution of two commonly observed polycrystalline morphologies, which give rise to <110> textures, will be described as well as the development of four films grown to produce <100>, <111>, and near <100>'' textures with various combinations of growth facets. These films were grown to test models of texture development. Films free of twins, microtwins, and stacking faults are deposited when only (100) facets are permitted to grow. In polycrystalline materials, special conditions must be met to avoid the formation of planar defects at the peripheries of individual crystallites. The planar defects grow from (111) or mixed microfaceted surfaces. Twinning plays an important role in growth of (111) faceted surfaces. The films have been characterized with Raman spectroscopy, x-ray diffraction, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and optical methods. 13 refs., 7 figs.

  15. Low temperature CVD of TaB/sub 2/

    SciTech Connect

    Randich, E.

    1980-01-01

    Crystalline TaB/sub 2/ has been deposited using the CVD reaction of TaCl/sub 5/ and B/sub 2/H/sub 6/ in the temperature range of 773-1200/sup 0/K. Thermodynamic calculations have been made which compare the use of both B/sub 2/H/sub 6/ and BCl/sub 3/ as B source gases. The deposits obtained with B/sub 2/H/sub 6/ exhibited extremely small crystal size and contained amorphous B when the deposition temperature was below approx. 873/sup 0/K but were substoichiometric in B above this temperature. Carbon analysis indicated that C may substitute for B and thereby stabilize the diboride structure at high deposition temperatures. Microhardness of the coatings decreased with increasing B/Ta ratio and decreasing crystal size.

  16. A controlled atmosphere tube furnace was designed for thermal CVD

    NASA Astrophysics Data System (ADS)

    Rashid, M.; Bhatti, J. A.; Hussain, F.; Imran, M.; Khawaja, I. U.; Chaudhary, K. A.; Ahmad, S. A.

    2013-06-01

    High quality materials were used for the fabrication of hi-tech tube furnace. The furnace was especially suitable for thermal Chemical Vapor Deposition (CVD). High density alumina tube was used for the fabrication of furnace. The tube furnace was found to have three different temperature zones with maximum temperature at central zone was found to be 650°C. The flexible heating tape with capacity of 760°C was wrapped on the tube. To minimize the heat losses, asbestos and glass wool were used on heating tape. The temperature of the tube furnace was controlled by a digital temperature controller had accuracy of ±1°C. Methanol was taken as the representative of hydrocarbon sources, to give thin film of carbon. The a-C: H structure was investigated by conventional techniques using optical microscopy, FT-IR and SEM.

  17. Cardiovascular Risk Factors of Taxi Drivers.

    PubMed

    Elshatarat, Rami Azmi; Burgel, Barbara J

    2016-06-01

    In the United States (U.S.), cardiovascular disease (CVD) is a major leading cause of death. Despite the high mortality rate related to CVD, little is known about CVD risk factors among urban taxi drivers in the U.S. A cross-sectional design was used to identify the predictors of high cardiovascular risk factors among taxi drivers. Convenience sampling method was used to recruit 130 taxi drivers. A structured questionnaire was used to obtain the data. The sample was male (94 %), age mean (45 ± 10.75) years, married (54 %), born outside of the USA (55 %), had some college or below (61.5 %), night drivers (50.8 %), and driving on average 9.7 years and 41 h/week. About 79 % of them were eligible for CVD prevention, and 35.4 % had high CVD risk factors (4-9 risk factors). A CVD high-risk profile had a significant relationship with the subjects who were ≥55 years old; had hypertension, diabetes, or hyperlipidemia; were drinking alcohol ≥2 times/week; and had insufficient physical activity. Subjects who worked as a taxi driver for more than 10 years (OR 4.37; 95 % CI 1.82, 10.50) and had mental exertion from cab driving >5 out of 10 (OR 2.63; 95 % CI 1.05, 6.57) were more likely to have a CVD high-risk profile. As a conclusion, system-level or worksite interventions include offering healthy food at taxi dispatching locations, creating a work culture of frequent walking breaks, and interventions focusing on smoking, physical activity, and weight management. Improving health insurance coverage for this group of workers is recommended. PMID:27151321

  18. Underutilisation of cardiovascular medications among at-risk individuals

    PubMed Central

    Lewis, S J; Robinson, J G; Fox, K M; Grandy, S

    2010-01-01

    Aims: Guidelines recommend antihypertensive, lipid-lowering and/or antiplatelet therapy for prevention of cardiovascular disease (CVD). This study examined the utilisation of cardiovascular therapies among individuals at CVD risk to assess adherence to guidelines. Methods: Respondents to the SHIELD study were classified based on National Cholesterol Education Program Adult Treatment Panel III risk categories. High coronary heart disease (CHD) risk (n = 7510) was defined as self-reported diagnosis of heart disease/heart attack, narrow or blocked arteries, stroke or diabetes; moderate risk (n = 4823) included respondents with ≥ 2 risk factors (i.e., men > 45 years, women > 55 years, hypertension, low high-density lipoprotein cholesterol, smoking and family history of CHD); and low risk (n = 5307) was 0–1 risk factor. Respondents reporting a myocardial infarction, stroke or revascularisation at baseline (prior CVD event) (n = 3777), those reporting a new CVD event during 2 years of follow up (n = 953), and those with type 2 diabetes mellitus (n = 3937) were evaluated. The proportion of respondents reporting treatment with lipid-lowering, antiplatelet or antihypertensive agents was calculated. Results: Utilisation of lipid-lowering therapy was low (≤ 25%) in each group. Prescription antithrombotic therapy was minimal among respondents with prior CVD events, but 47% received antihypertensive medication. No use before or after a new CVD event was reported by 36% of respondents for lipid-lowering, 32% for antithrombotic and > 50% for antihypertensive medications. Conclusions: More than 50% of at-risk respondents and > 33% of respondents with new CVD events were not taking CVD therapy as recommended by guidelines. PMID:19909379

  19. Menthol cigarettes and the cardiovascular risks of people living with HIV

    PubMed Central

    Míguez-Burbano, María José; Vargas, Mayra; Quiros, Clery; Lewis, John E.; Espinoza, Luis; Asthana, Deshratan

    2014-01-01

    The possibility that menthol cigarettes add to the deleterious cardiovascular effects of smoking has been barely discussed. Although cardiovascular diseases (CVD) are at the forefront of medical concerns of people living with HIV (PLWH), an important, yet unknown, issue for clinicians and public health authorities is whether use of menthol-flavored cigarettes heightens CVD risk factors. Our study aims to assess traditional (10-year risk using the Framingham Risk Model) and nontraditional CVD risk factors and to contrast the effects of menthol-flavored versus non-menthol flavored cigarettes on these risk factors. Compared to controls, menthol smokers were twice as likely to have hypertension. Users of menthol-flavored cigarettes had higher body mass index values, and increased risk of abdominal obesity. Multivariate analyses indicated that menthol smokers doubled the odds of having moderate to high CVD risk. This finding is highly significant given the widespread use of menthol-flavored cigarettes, particularly among women, minorities, and PLWH. PMID:24581861

  20. Transfer printing of CVD graphene FETs on patterned substrates

    NASA Astrophysics Data System (ADS)

    Abhilash, T. S.; de Alba, R.; Zhelev, N.; Craighead, H. G.; Parpia, J. M.

    2015-08-01

    We describe a simple and scalable method for the transfer of CVD graphene for the fabrication of field effect transistors. This is a dry process that uses a modified RCA-cleaning step to improve the surface quality. In contrast to conventional fabrication routes where lithographic steps are performed after the transfer, here graphene is transferred to a pre-patterned substrate. The resulting FET devices display nearly zero Dirac voltage, and the contact resistance between the graphene and metal contacts is on the order of 910 +/- 340 Ω μm. This approach enables formation of conducting graphene channel lengths up to one millimeter. The resist-free transfer process provides a clean graphene surface that is promising for use in high sensitivity graphene FET biosensors.We describe a simple and scalable method for the transfer of CVD graphene for the fabrication of field effect transistors. This is a dry process that uses a modified RCA-cleaning step to improve the surface quality. In contrast to conventional fabrication routes where lithographic steps are performed after the transfer, here graphene is transferred to a pre-patterned substrate. The resulting FET devices display nearly zero Dirac voltage, and the contact resistance between the graphene and metal contacts is on the order of 910 +/- 340 Ω μm. This approach enables formation of conducting graphene channel lengths up to one millimeter. The resist-free transfer process provides a clean graphene surface that is promising for use in high sensitivity graphene FET biosensors. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr03501e

  1. 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

  2. Absolute partial photoionization cross sections of ozone.

    SciTech Connect

    Berkowitz, J.; Chemistry

    2008-04-01

    Despite the current concerns about ozone, absolute partial photoionization cross sections for this molecule in the vacuum ultraviolet (valence) region have been unavailable. By eclectic re-evaluation of old/new data and plausible assumptions, such cross sections have been assembled to fill this void.

  3. Solving Absolute Value Equations Algebraically and Geometrically

    ERIC Educational Resources Information Center

    Shiyuan, Wei

    2005-01-01

    The way in which students can improve their comprehension by understanding the geometrical meaning of algebraic equations or solving algebraic equation geometrically is described. Students can experiment with the conditions of the absolute value equation presented, for an interesting way to form an overall understanding of the concept.

  4. Teaching Absolute Value Inequalities to Mature Students

    ERIC Educational Resources Information Center

    Sierpinska, Anna; Bobos, Georgeana; Pruncut, Andreea

    2011-01-01

    This paper gives an account of a teaching experiment on absolute value inequalities, whose aim was to identify characteristics of an approach that would realize the potential of the topic to develop theoretical thinking in students enrolled in prerequisite mathematics courses at a large, urban North American university. The potential is…

  5. Increasing Capacity: Practice Effects in Absolute Identification

    ERIC Educational Resources Information Center

    Dodds, Pennie; Donkin, Christopher; Brown, Scott D.; Heathcote, Andrew

    2011-01-01

    In most of the long history of the study of absolute identification--since Miller's (1956) seminal article--a severe limit on performance has been observed, and this limit has resisted improvement even by extensive practice. In a startling result, Rouder, Morey, Cowan, and Pfaltz (2004) found substantially improved performance with practice in the…

  6. On Relative and Absolute Conviction in Mathematics

    ERIC Educational Resources Information Center

    Weber, Keith; Mejia-Ramos, Juan Pablo

    2015-01-01

    Conviction is a central construct in mathematics education research on justification and proof. In this paper, we claim that it is important to distinguish between absolute conviction and relative conviction. We argue that researchers in mathematics education frequently have not done so and this has lead to researchers making unwarranted claims…

  7. Absolute Points for Multiple Assignment Problems

    ERIC Educational Resources Information Center

    Adlakha, V.; Kowalski, K.

    2006-01-01

    An algorithm is presented to solve multiple assignment problems in which a cost is incurred only when an assignment is made at a given cell. The proposed method recursively searches for single/group absolute points to identify cells that must be loaded in any optimal solution. Unlike other methods, the first solution is the optimal solution. The…

  8. Nonequilibrium equalities in absolutely irreversible processes

    NASA Astrophysics Data System (ADS)

    Murashita, Yuto; Funo, Ken; Ueda, Masahito

    2015-03-01

    Nonequilibrium equalities have attracted considerable attention in the context of statistical mechanics and information thermodynamics. Integral nonequilibrium equalities reveal an ensemble property of the entropy production σ as = 1 . Although nonequilibrium equalities apply to rather general nonequilibrium situations, they break down in absolutely irreversible processes, where the forward-path probability vanishes and the entropy production diverges. We identify the mathematical origins of this inapplicability as the singularity of probability measure. As a result, we generalize conventional integral nonequilibrium equalities to absolutely irreversible processes as = 1 -λS , where λS is the probability of the singular part defined based on Lebesgue's decomposition theorem. The acquired equality contains two physical quantities related to irreversibility: σ characterizing ordinary irreversibility and λS describing absolute irreversibility. An inequality derived from the obtained equality demonstrates the absolute irreversibility leads to the fundamental lower bound on the entropy production. We demonstrate the validity of the obtained equality for a simple model.

  9. Stimulus Probability Effects in Absolute Identification

    ERIC Educational Resources Information Center

    Kent, Christopher; Lamberts, Koen

    2016-01-01

    This study investigated the effect of stimulus presentation probability on accuracy and response times in an absolute identification task. Three schedules of presentation were used to investigate the interaction between presentation probability and stimulus position within the set. Data from individual participants indicated strong effects of…

  10. Precision absolute positional measurement of laser beams.

    PubMed

    Fitzsimons, Ewan D; Bogenstahl, Johanna; Hough, James; Killow, Christian J; Perreur-Lloyd, Michael; Robertson, David I; Ward, Henry

    2013-04-20

    We describe an instrument which, coupled with a suitable coordinate measuring machine, facilitates the absolute measurement within the machine frame of the propagation direction of a millimeter-scale laser beam to an accuracy of around ±4 μm in position and ±20 μrad in angle. PMID:23669658

  11. Community-responsive interventions to reduce cardiovascular risk in American Indians.

    PubMed

    Jobe, Jared B; Adams, Alexandra K; Henderson, Jeffrey A; Karanja, Njeri; Lee, Elisa T; Walters, Karina L

    2012-08-01

    American Indian and Alaska Native (AI/AN) populations bear a heavy burden of cardiovascular disease (CVD), and they have the highest rates of risk factors for CVD, such as cigarette smoking, obesity, and diabetes, of any U.S. population group. Yet, few randomized controlled trials have been launched to test potential preventive interventions in Indian Country. Five randomized controlled trials were initiated recently in AI/AN communities to test the effectiveness of interventions targeting adults and/or children to promote healthy behaviors that are known to impact biological CVD risk factors. This article provides a context for and an overview of these five trials. The high burden of CVD among AI/AN populations will worsen unless behaviors and lifestyles affecting CVD risk can be modified. These five trials, if successful, represent a starting point in addressing these significant health disparities. PMID:22983753

  12. Management of Cardiovascular Risk in Patients with Chronic Inflammatory Diseases: Current Evidence and Future Perspectives.

    PubMed

    Lindhardsen, Jesper; Kristensen, Søren Lund; Ahlehoff, Ole

    2016-02-01

    An increased risk of cardiovascular disease (CVD) has been observed in a range of chronic inflammatory diseases (CID), including rheumatoid arthritis (RA), psoriasis, inflammatory bowel diseases (IBD), and systemic lupus erythematosus (SLE). The increased risk of CVDs and reduced life expectancy in these conditions has stimulated considerable research and started an ongoing discussion on the need for a multidisciplinary approach and dedicated guidelines on CVD prevention in these patients. In addition, the possibility of inhibiting inflammation as a means to preventing CVD in these patients has gained considerable interest in recent years. We briefly summarize the current level of evidence of the association between CIDs and CVD and cardiovascular risk management recommendations. Perspectives of ongoing and planned trials are discussed in consideration of potential ways to improve primary and secondary CVD prevention in patients with CID. PMID:26293235

  13. Community-Responsive Interventions to Reduce Cardiovascular Risk in American Indians

    ERIC Educational Resources Information Center

    Jobe, Jared B.; Adams, Alexandra K.; Henderson, Jeffrey A.; Karanja, Njeri; Lee, Elisa T.; Walters, Karina L.

    2012-01-01

    American Indian and Alaska Native (AI/AN) populations bear a heavy burden of cardiovascular disease (CVD), and they have the highest rates of risk factors for CVD, such as cigarette smoking, obesity, and diabetes, of any U.S. population group. Yet, few randomized controlled trials have been launched to test potential preventive interventions in…

  14. Patient and general practitioner attitudes to taking medication to prevent cardiovascular disease after receiving detailed information on risks and benefits of treatment: a qualitative study

    PubMed Central

    2011-01-01

    Background There are now effective drugs to prevent cardiovascular disease and guidelines recommend their use. Patients do not always choose to accept preventive medication at levels of risk reduction recommended in guidelines. The purpose of the study was to identify and explore the attitudes of patients and general practitioners towards preventative medication for cardiovascular disease (CVD) after they have received information about it; to identify implications for practice and prescribing. Methods Qualitative interviews with GPs and patients following presentation of in depth information about CVD risks and the absolute effects of medication. Setting: GP practices in Birmingham, United Kingdom. Results In both populations: wide variation on attitudes to preventative medication; concerns about unnecessary drug taking & side effects; preferring to consider lifestyle changes first. In patient population: whatever their attitudes to medication were, the vast majority explained that they would ultimately do what their GP recommended; there was some misunderstanding of the distinction between curative and preventative medication. A common theme was the degree of trust in their doctors' judgement and recommendations, which contrasted with scepticism of the role of pharmaceutical companies and academics. Scepticism in guidelines was also common among doctors although many nevertheless recommended treatment for their patients Conclusions A guideline approach to prescribing preventative medication could be against the interests and preferences of the patient. GPs must take extra care to explain what preventative medication is and why it is recommended, attempt to discern preferences and make recommendations balancing these potentially conflicting concerns. PMID:21703010

  15. CARDIOVASCULAR DISEASE RISK FACTORS AMONG RURAL KAZAKH POPULATION

    PubMed Central

    KULKAYEVA, GULNARA; HARUN-OR-RASHID, MD.; YOSHIDA, YOSHITOKU; TULEBAYEV, KAZBEK; SAKAMOTO, JUNICHI

    2012-01-01

    ABSTRACT Cardiovascular diseases (CVDs) have remained a leading cause of mortality in Kazakhstan. The objectives of the present study were to estimate the prevalence of CVD risk factors (RFs) among the Kazakh population, and their ability to identify those CVD RFs. We interviewed 611 subjects aged 25–65 years using a structured self-administered questionnaire from April to July, 2008. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated to determine associations between CVD RFs and its correlations, such as socioeconomic status and level of knowledge of CVD RFs through a logistic regression model. Mean age of the respondents was 43.2 years, and 49.8% were male. Tobacco smoking, overweight (body mass index ≥ 25.0), hypertension (systolic blood pressure ≥ 140 mm Hg and diastolic blood pressure ≥ 90 mm Hg), and alcohol drinking were identified as important CVD RFs. Risk of overweight was greatest among the population aged 45–54 years, with an OR of 5.3 (95% CI=3.1–9.2). The overweight population was significantly associated with higher income (OR=1.6, 95% CI=1.1–2.4) and knowledge of RF (OR=1.7, 95% CI=1.2–2.4), with p<0.05. Only 25.0% of respondents had good knowledge about CVD RFs. Alcohol drinking was inversely related to the level of knowledge about CVD RFs (OR=0.7, 95% CI=0.5–0.9). We concluded that CVD RFs were very high among the Kazakh population, although their level of knowledge to identify those RFs was very low. Increasing knowledge about CVD RFs through awareness campaign activities can reduce CVD-related morbidity and mortality and ensure a better quality of life for the Kazakh population. PMID:22515111

  16. Combined Use of Absolute and Differential Seismic Arrival Time Data to Improve Absolute Event Location

    NASA Astrophysics Data System (ADS)

    Myers, S.; Johannesson, G.

    2012-12-01

    Arrival time measurements based on waveform cross correlation are becoming more common as advanced signal processing methods are applied to seismic data archives and real-time data streams. Waveform correlation can precisely measure the time difference between the arrival of two phases, and differential time data can be used to constrain relative location of events. Absolute locations are needed for many applications, which generally requires the use of absolute time data. Current methods for measuring absolute time data are approximately two orders of magnitude less precise than differential time measurements. To exploit the strengths of both absolute and differential time data, we extend our multiple-event location method Bayesloc, which previously used absolute time data only, to include the use of differential time measurements that are based on waveform cross correlation. Fundamentally, Bayesloc is a formulation of the joint probability over all parameters comprising the multiple event location system. The Markov-Chain Monte Carlo method is used to sample from the joint probability distribution given arrival data sets. The differential time component of Bayesloc includes scaling a stochastic estimate of differential time measurement precision based the waveform correlation coefficient for each datum. For a regional-distance synthetic data set with absolute and differential time measurement error of 0.25 seconds and 0.01 second, respectively, epicenter location accuracy is improved from and average of 1.05 km when solely absolute time data are used to 0.28 km when absolute and differential time data are used jointly (73% improvement). The improvement in absolute location accuracy is the result of conditionally limiting absolute location probability regions based on the precise relative position with respect to neighboring events. Bayesloc estimates of data precision are found to be accurate for the synthetic test, with absolute and differential time measurement

  17. Cardiovascular Risk Factors (Diabetes, Hypertension, Hypercholesterolemia and Metabolic Syndrome) in Older People with Intellectual Disability: Results of the HA-ID Study

    ERIC Educational Resources Information Center

    de Winter, C. F.; Bastiaanse, L. P.; Hilgenkamp, T. I. M.; Evenhuis, H. M.; Echteld, M. A.

    2012-01-01

    Hypertension, diabetes, hypercholesterolemia and the metabolic syndrome are important risk factors for cardiovascular disease (CVD). In older people with intellectual disability (ID), CVD is a substantial morbidity risk. The aims of the present study, which was part of the Healthy Ageing in Intellectual Disability (HA-ID) study, were (1) to…

  18. Adherence index based on the American Heart Association 2006 diet and lifestyle recommendations: associations with cardiovascular disease risk factors in the Boston Puerto Rican health study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2006, the AHA released diet and lifestyle recommendations (AHA-DLR) for cardiovascular disease (CVD) risk reduction. The effect of adherence to these recommendations on CVD risk is unknown. Our objective was to develop a unique diet and lifestyle score based on the AHA-DLR and to evaluate this sc...

  19. Tree nut consumption is associated with better adiposity measures and cardiovascular and metabolic syndrome health risk factors in U.S adults: NHANES 2005-2010

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous research has shown inconsistencies in the association of tree nut consumption with risk factors for cardiovascular disease (CVD) and metabolic syndrome (MetS). To determine the association of tree nut consumption with risk factors for CVD and for MetS in adults. NHANES 2005-2010 data were u...

  20. Racial/ethnic residential segregation and cardiovascular disease risk

    PubMed Central

    Kershaw, Kiarri N.; Albrecht, Sandra S.

    2015-01-01

    A growing body of research has examined whether racial/ethnic residential segregation contributes to health disparities, but recent findings in the literature, particularly with respect to cardiovascular disease (CVD) risk, have not been summarized. This review provides an overview of findings from studies of racial/ethnic residential segregation of non-Hispanic blacks and Hispanics with CVD risk published between January 2011 and July 2014. The majority of studies of black segregation showed higher segregation was related to higher CVD risk, although relationships were less clear for certain outcomes. Relationships among Hispanics were more mixed and appeared to vary widely by factors such as gender, country of origin, racial identity, and acculturation. Implications for research on racial/ethnic disparities in CVD and lingering gaps in the literature are discussed as well. PMID:25893031

  1. Characterisation of CVD diamond detectors used for fast neutron flux monitoring

    NASA Astrophysics Data System (ADS)

    Foulon, F.; Bergonzo, P.; Amosov, V. N.; Kaschuck, Yu.; Frunze, V.; Tromson, D.; Brambilla, A.

    2002-01-01

    Natural diamond detectors (NDD) have been successfully used for fast neutron spectrometry on various fusion installations in plasma diagnostics. These detectors can work at high temperature, are radiation hard and exhibit a high energy resolution. However, the use of NDD is limited by the availability of IIa type diamonds exhibiting high electronic properties. With the recent advance in the growth of high quality chemically vapour deposited (CVD) diamond at LETI, CVD diamond appears to be a very promising material for plasma diagnostics. We present here for the first time results of the use of CVD diamond detectors for fast neutron flux monitoring on a neutron generator. The characteristics of CVD diamond detectors are compared with that of high quality NDD made by TRINITI. Pulse height spectra have been measured with CVD detectors and NDD under both 5.5 MeV alpha particles and 14.1 MeV neutrons. The quality of CVD diamond enables the recording of structured spectra allowing the distinction between the different neutron reactions on carbon. The efficiency of CVD diamond monitors and their actual limitations are analysed and discussed.

  2. Development of Micro and Nano Crystalline CVD Diamond TL/OSL Radiation Detectors for Clinical Applications

    NASA Astrophysics Data System (ADS)

    Barboza-Flores, Marcelino

    2015-03-01

    Modern radiotherapy methods requires the use of high photon radiation doses delivered in a fraction to small volumes of cancer tumors. An accurate dose assessment for highly energetic small x-ray beams in small areas, as in stereotactic radiotherapy, is necessary to avoid damage to healthy tissue surrounding the tumor. Recent advances on the controlled synthesis of CVD diamond have demonstrated the possibility of using high quality micro and nano crystalline CVD as an efficient detector and dosimeter suitable for high energy photons and energetic particle beams. CVD diamond is a very attractive material for applications in ionizing radiation dosimetry, particularly in the biomedical field since the radiation absorption by a CVD diamond is very close to that of soft tissue. Furthermore, diamond is stable, non-toxic and radiation hard. In the present work we discuss the CVD diamond properties and dosimeter performance and discuss its relevance and advantages of various dosimetry methods, including thermally stimulated luminescence (TL) as well as optically stimulated luminescence (OSL). The recent CVD improved method of growth allows introducing precisely controlled impurities into diamond to provide it with high dosimetry sensitivity. For clinical dosimetry applications, high accuracy of dose measurements, low fading, high sensitivity, good reproducibility and linear dose response characteristics are very important parameters which all are found in CVD diamonds specimens. In some cases, dose linearity and reproducibility in CVD diamond have been found to be higher than standard commercial TLD materials like LiF. In the present work, we discuss the state-of-the art developments in dosimetry applications using CVD diamond. The financial support from Conacyt (Mexico) is greatly acknowledged

  3. Rolling-contact fatigue and wear of CVD-SiC with residual surface compression

    SciTech Connect

    Chao, L.Y.; Lakshminarayanan, R.; Shetty, D.K.; Cutler, R.A.

    1995-09-01

    The rolling-contact fatigue life and wear of CVD-SiC coatings with surface compression were studied using a three-ball-on-rod rolling-contact fatigue (RCF) tester. Two levels of surface compression in the coatings, approximately 190 {micro}m thick, were introduced by using substrates of a liquid-phase sintered SiC and a SiC-30 vol% TiC to obtain desired thermal-expansion mismatches with the CVD-SiC. Residual surface compressions of 250 and 680 MPa were measured in the CVD-SiC coatings on SiC and SiC-30 vol% TiC substrates, respectively, by a strain-gage technique. In the RCF test, the fatigue life of the CVD-SiC coating with the moderate surface compression was limited by severe wear by a brittle fracture mechanism at a Hertzian contact stress of 5.5 GPa. The CVD-SiC coating on the SiC-30 vol% TiC composite, on the other hand, did not show measurable wear. A majority of the tests (11 out of 16) were suspended at 100 h or stopped due to failure of the steel balls. Five tests stopped due to spalling of the CVD-SiC coating at weak interfaces 10 to 15 {micro}m below the contact surface. Examination of the microstructure of the CVD-SiC coating in cross sections revealed that the weak interfaces that led to the spalling were related to discontinuous growth of the CVD-SiC in the form of nodules or growth regions. Elimination of these defective structures is likely to enhance the tribological performance of surface-toughened CVD-SiC.

  4. A faith-based screening/education program for diabetes, CVD, and stroke in rural African Americans.

    PubMed

    Frank, Deborah; Grubbs, Laurie

    2008-01-01

    The purpose of this study was to examine the effectiveness of a faith-based health screening/education program to ultimately reduce risk factors for diabetes (DM), cardiovascular disease (CVD), and stroke (CVA) in a southern, rural, African-American population. Over 120 parishioners from four rural African-American churches attended health education/screening programs offered as a part of their Bible Study. The majority of participants were female, married, with a mean age of 45 years. The program included education about prevention of cardiovascular disease (CVD), diabetes (DM), and stroke (CVA) followed by health screening, individual counseling, and healthy snacks. Pre/post test surveys for health knowledge were given. While the pre/post health knowledge scores showed some improvement, they were not statistically significant indicating the need for more than one program. Participants under age 30 and over age 60 years had the least knowledge on the pretest about these illnesses compared to the middle-age group. Almost 50% were found to have high blood pressure, and 14% had high blood sugar levels of which they were unaware. Participant and pastor feedback was positive and supported the feasibility of ongoing faith-based screening/ education programs as one way to meet the health needs of a rural African-American population. PMID:18717208

  5. Characterization of CVD micrometer-size diamond (abstract)

    NASA Astrophysics Data System (ADS)

    Ohsumi, K.; Hagiya, K.; Miyamoto, M.; Matsuda, J.; Ohmasa, M.

    1989-07-01

    formed from carbonaceous materials by impact shock or directly formed from vapor. Recent discovery of vapor-growth diamonds in carbonaceous chondrites has generated a renewed interest in the origin of ureilite diamonds. Two types of micrometer-size diamonds were prepared. One of them was grown under low pressure by chemical vapor deposition (CVD) from gaseous mixtures of H2 and CH4, and another was synthesized by shock effect (kindly offered by Nippon Oil & Fats Co., Ltd.) The micro-Laue method was applied to them in order to get information about their microstructures. Two characteristics are recognized in profiles of reflections themselves and in whole patterns of the Laue photographs. The reflections of CVD diamonds are elongated but symmetric in their profiles and are distributed regularly as they are indexed by the diamond lattice, while those of shock effect are also elongated and asymmetric, and are distributed at random as they cannot be indexed. The characteristics observed by the method may be useful to ascribe the origin to CVD or shock effect.

  6. A Novel Al/TiN/CVD-W Structure to Eliminate Resistance Anomaly in Deep Submicron Al/CVD-W Interconnects

    NASA Astrophysics Data System (ADS)

    Sekiguchi, Mitsuru; Fujii, Toyokazu; Yamanaka, Michinari; Fukumoto, Masanori

    1995-02-01

    The sheet resistance increase of Al/chemical vapor deposition (CVD)-W interconnects after low-temperature annealing has been investigated. Anomalous sheet resistance increase depending on the linewidth in sub-half-micron Al-Si-Cu/CVD-W lines after 450° C annealing is found for the first time. The sheet resistance increase of the Al/CVD-W lines becomes larger for narrower linewidth after annealing. It is considered that this anomalous sheet resistance increase is due to more nonuniform high-resistivity WAl12 formation in the narrower lines. Using a TiN interlayer to eliminate WAl12 formation, sub-half-micron lines of a new Al-Si-Cu/TiN/CVD-W structure have demonstrated sufficiently low line resistance even after 450° C annealing for 300 min and exhibited 6 times longer electromigration (EM) lifetime compared with the previous Al-Si-Cu/CVD-W structure. This longer EM lifetime is also attributed to the suppression of WAl12 formation. This structure is one of the most promising interconnect structures for realizing sub-half-micron interconnects in future ULSIs.

  7. Preventing CVD in resource-poor areas: perspectives from the 'real-world'.

    PubMed

    Stewart, Simon; Sliwa, Karen

    2009-07-01

    An evolving epidemic of cardiovascular disease (CVD) is having a profound effect on the health of vulnerable populations in low-to-middle income countries with limited resources. Despite some encouraging signs (particularly initiatives from the WHO), global and regional apathy towards noncommunicable forms of CVD adds to the complexity of issues to consider when establishing cost-effective prevention programs. We present our perspective on overcoming the myriad of barriers to providing cost-effective measures for CVD prevention in a resource-poor environment through the 'prism' of our experiences in establishing the Heart of Soweto Study in South Africa. PMID:19554008

  8. Controlled incorporation of mid-to-high Z transition metals in CVD diamond

    SciTech Connect

    Biener, M M; Biener, J; Kucheyev, S O; Wang, Y M; El-Dasher, B; Teslich, N E; Hamza, A V; Obloh, H; Mueller-Sebert, W; Wolfer, M; Fuchs, T; Grimm, M; Kriele, A; Wild, C

    2010-01-08

    We report on a general method to fabricate transition metal related defects in diamond. Controlled incorporation of Mo and W in synthetic CVD diamond was achieved by adding volatile metal precursors to the diamond chemical vapor deposition (CVD) growth process. Effects of deposition temperature, grain structure and precursor exposure on the doping level were systematically studied, and doping levels of up to 0.25 at.% have been achieved. The metal atoms are uniformly distributed throughout the diamond grains without any indication of inclusion formation. These results are discussed in context of the kinetically controlled growth process of CVD diamond.

  9. Radiation monitoring with CVD Diamonds and PIN Diodes at BaBar

    SciTech Connect

    Bruinsma, M.; Burchat, P.; Curry, S.; Edwards, A.J.; Kagan, H.; Kass, R.; Kirkby, D.; Majewski, S.; Petersen, B.A.; /UC, Irvine /SLAC /Ohio State U.

    2008-02-13

    The BaBar experiment at the Stanford Linear Accelerator Center has been using two polycrystalline chemical vapor deposition (pCVD) diamonds and 12 silicon PIN diodes for radiation monitoring and protection of the Silicon Vertex Tracker (SVT). We have used the pCVD diamonds for more than 3 years, and the PIN diodes for 7 years. We will describe the SVT and SVT radiation monitoring system as well as the operational difficulties and radiation damage effects on the PIN diodes and pCVD diamonds in a high-energy physics environment.

  10. Absolute and relative dosimetry for ELIMED

    SciTech Connect

    Cirrone, G. A. P.; Schillaci, F.; Scuderi, V.; Cuttone, G.; Candiano, G.; Musumarra, A.; Pisciotta, P.; Romano, F.; Carpinelli, M.; Presti, D. Lo; Raffaele, L.; Tramontana, A.; Cirio, R.; Sacchi, R.; Monaco, V.; Marchetto, F.; Giordanengo, S.

    2013-07-26

    The definition of detectors, methods and procedures for the absolute and relative dosimetry of laser-driven proton beams is a crucial step toward the clinical use of this new kind of beams. Hence, one of the ELIMED task, will be the definition of procedures aiming to obtain an absolute dose measure at the end of the transport beamline with an accuracy as close as possible to the one required for clinical applications (i.e. of the order of 5% or less). Relative dosimetry procedures must be established, as well: they are necessary in order to determine and verify the beam dose distributions and to monitor the beam fluence and the energetic spectra during irradiations. Radiochromic films, CR39, Faraday Cup, Secondary Emission Monitor (SEM) and transmission ionization chamber will be considered, designed and studied in order to perform a fully dosimetric characterization of the ELIMED proton beam.

  11. Probing absolute spin polarization at the nanoscale.

    PubMed

    Eltschka, Matthias; Jäck, Berthold; Assig, Maximilian; Kondrashov, Oleg V; Skvortsov, Mikhail A; Etzkorn, Markus; Ast, Christian R; Kern, Klaus

    2014-12-10

    Probing absolute values of spin polarization at the nanoscale offers insight into the fundamental mechanisms of spin-dependent transport. Employing the Zeeman splitting in superconducting tips (Meservey-Tedrow-Fulde effect), we introduce a novel spin-polarized scanning tunneling microscopy that combines the probing capability of the absolute values of spin polarization with precise control at the atomic scale. We utilize our novel approach to measure the locally resolved spin polarization of magnetic Co nanoislands on Cu(111). We find that the spin polarization is enhanced by 65% when increasing the width of the tunnel barrier by only 2.3 Å due to the different decay of the electron orbitals into vacuum. PMID:25423049

  12. Absolute-magnitude distributions of supernovae

    SciTech Connect

    Richardson, Dean; Wright, John; Jenkins III, Robert L.; Maddox, Larry

    2014-05-01

    The absolute-magnitude distributions of seven supernova (SN) types are presented. The data used here were primarily taken from the Asiago Supernova Catalogue, but were supplemented with additional data. We accounted for both foreground and host-galaxy extinction. A bootstrap method is used to correct the samples for Malmquist bias. Separately, we generate volume-limited samples, restricted to events within 100 Mpc. We find that the superluminous events (M{sub B} < –21) make up only about 0.1% of all SNe in the bias-corrected sample. The subluminous events (M{sub B} > –15) make up about 3%. The normal Ia distribution was the brightest with a mean absolute blue magnitude of –19.25. The IIP distribution was the dimmest at –16.75.

  13. Absolute radiometry and the solar constant

    NASA Technical Reports Server (NTRS)

    Willson, R. C.

    1974-01-01

    A series of active cavity radiometers (ACRs) are described which have been developed as standard detectors for the accurate measurement of irradiance in absolute units. It is noted that the ACR is an electrical substitution calorimeter, is designed for automatic remote operation in any environment, and can make irradiance measurements in the range from low-level IR fluxes up to 30 solar constants with small absolute uncertainty. The instrument operates in a differential mode by chopping the radiant flux to be measured at a slow rate, and irradiance is determined from two electrical power measurements together with the instrumental constant. Results are reported for measurements of the solar constant with two types of ACRs. The more accurate measurement yielded a value of 136.6 plus or minus 0.7 mW/sq cm (1.958 plus or minus 0.010 cal/sq cm per min).

  14. Asteroid absolute magnitudes and slope parameters

    NASA Technical Reports Server (NTRS)

    Tedesco, Edward F.

    1991-01-01

    A new listing of absolute magnitudes (H) and slope parameters (G) has been created and published in the Minor Planet Circulars; this same listing will appear in the 1992 Ephemerides of Minor Planets. Unlike previous listings, the values of the current list were derived from fits of data at the V band. All observations were reduced in the same fashion using, where appropriate, a single basis default value of 0.15 for the slope parameter. Distances and phase angles were computed for each observation. The data for 113 asteroids was of sufficiently high quality to permit derivation of their H and G. These improved absolute magnitudes and slope parameters will be used to deduce the most reliable bias-corrected asteroid size-frequency distribution yet made.

  15. Absolute calibration of TFTR helium proportional counters

    SciTech Connect

    Strachan, J.D.; Diesso, M.; Jassby, D.; Johnson, L.; McCauley, S.; Munsat, T.; Roquemore, A.L.; Barnes, C.W. |; Loughlin, M. |

    1995-06-01

    The TFTR helium proportional counters are located in the central five (5) channels of the TFTR multichannel neutron collimator. These detectors were absolutely calibrated using a 14 MeV neutron generator positioned at the horizontal midplane of the TFTR vacuum vessel. The neutron generator position was scanned in centimeter steps to determine the collimator aperture width to 14 MeV neutrons and the absolute sensitivity of each channel. Neutron profiles were measured for TFTR plasmas with time resolution between 5 msec and 50 msec depending upon count rates. The He detectors were used to measure the burnup of 1 MeV tritons in deuterium plasmas, the transport of tritium in trace tritium experiments, and the residual tritium levels in plasmas following 50:50 DT experiments.

  16. Absolute enantioselective separation: optical activity ex machina.

    PubMed

    Bielski, Roman; Tencer, Michal

    2005-11-01

    The paper describes methodology of using three independent macroscopic factors affecting molecular orientation to accomplish separation of a racemic mixture without the presence of any other chiral compounds, i. e., absolute enantioselective separation (AES) which is an extension of a concept of applying these factors to absolute asymmetric synthesis. The three factors may be applied simultaneously or, if their effects can be retained, consecutively. The resulting three mutually orthogonal or near orthogonal directors constitute a true chiral influence and their scalar triple product is the measure of the chirality of the system. AES can be executed in a chromatography-like microfluidic process in the presence of an electric field. It may be carried out on a chemically modified flat surface, a monolithic polymer column made of a mesoporous material, each having imparted directional properties. Separation parameters were estimated for these media and possible implications for the natural homochirality are discussed. PMID:16342798

  17. An absolute measure for a key currency

    NASA Astrophysics Data System (ADS)

    Oya, Shunsuke; Aihara, Kazuyuki; Hirata, Yoshito

    It is generally considered that the US dollar and the euro are the key currencies in the world and in Europe, respectively. However, there is no absolute general measure for a key currency. Here, we investigate the 24-hour periodicity of foreign exchange markets using a recurrence plot, and define an absolute measure for a key currency based on the strength of the periodicity. Moreover, we analyze the time evolution of this measure. The results show that the credibility of the US dollar has not decreased significantly since the Lehman shock, when the Lehman Brothers bankrupted and influenced the economic markets, and has increased even relatively better than that of the euro and that of the Japanese yen.

  18. From Hubble's NGSL to Absolute Fluxes

    NASA Technical Reports Server (NTRS)

    Heap, Sara R.; Lindler, Don

    2012-01-01

    Hubble's Next Generation Spectral Library (NGSL) consists of R-l000 spectra of 374 stars of assorted temperature, gravity, and metallicity. Each spectrum covers the wavelength range, 0.18-1.00 microns. The library can be viewed and/or downloaded from the website, http://archive.stsci.edu/prepds/stisngsll. Stars in the NGSL are now being used as absolute flux standards at ground-based observatories. However, the uncertainty in the absolute flux is about 2%, which does not meet the requirements of dark-energy surveys. We are therefore developing an observing procedure that should yield fluxes with uncertainties less than 1 % and will take part in an HST proposal to observe up to 15 stars using this new procedure.

  19. Trajectories of Metabolic Risk Factors and Biochemical Markers prior to the Onset of Cardiovascular Disease – The Doetinchem Cohort Study

    PubMed Central

    Hulsegge, Gerben; Spijkerman, Annemieke M. W.; van der Schouw, Yvonne T.; Bakker, Stephan J. L.; Gansevoort, Ron T.; Smit, Henriette A.; Verschuren, W. M. Monique

    2016-01-01

    Risk factors often develop at young age and are maintained over time, but it is not fully understood how risk factors develop over time preceding cardiovascular disease (CVD). Our objective was to examine how levels and trajectories of metabolic risk factors and biochemical markers prior to diagnosis differ between people with and without CVD over a period of up to 15–20 years. A total of 449 incident non-fatal and fatal CVD cases and 1,347 age- and sex-matched controls were identified in a prospective cohort between 1993 and 2011. Metabolic risk factors and biochemical markers were measured at five-year intervals prior to diagnosis. Trajectories of metabolic risk factors and biochemical markers were analysed using random coefficient analyses. Although not always statistically significant, participants with CVD had slightly more unfavourable levels for most metabolic risk factors and biochemical markers 15–20 years before diagnosis than controls. Subsequent trajectories until diagnosis were similar in participants with incident CVD and controls for body mass index, diastolic blood pressure, total cholesterol, HDL cholesterol, random glucose, triglycerides, gamma glutamyltransferase, C-reactive protein and uric acid. Trajectories were more unfavourable in participants with CVD than controls for systolic blood pressure, waist circumference and estimated glomerular filtration rate (p≤0.05). For example, among participants with CVD, systolic blood pressure increased on average by 9 mmHg over the 18-year period preceding diagnosis, whereas the increase among controls was 4 mmHg. In conclusion, unfavourable levels of metabolic risk factors and biochemical markers are present long before CVD, which indicates that the risk of CVD is already partly determined in young adulthood. This underscores the need for early prevention to reduce the burden of CVD. PMID:27203599

  20. Cell aging in relation to stress arousal and cardiovascular disease risk factors.

    PubMed

    Epel, Elissa S; Lin, Jue; Wilhelm, Frank H; Wolkowitz, Owen M; Cawthon, Richard; Adler, Nancy E; Dolbier, Christyn; Mendes, Wendy B; Blackburn, Elizabeth H

    2006-04-01

    We previously reported that psychological stress is linked to and possibly accelerates cellular aging, as reflected by lower PBMC telomerase and shortened telomeres. Psychological stress is a major risk factor for cardiovascular disease (CVD), with multiple behavioral and physiological mediators. Telomere shortness has been associated with CVD, but the relationship between low telomerase activity, a potential precursor to telomere shortening, and CVD risk factors has not been examined in humans. Here we examine whether telomere length and telomerase in leukocytes are associated with physiological signs of stress arousal and CVD risk factors in 62 healthy women. Low telomerase activity in leukocytes was associated with exaggerated autonomic reactivity to acute mental stress and elevated nocturnal epinephrine. Further, low telomerase activity was associated with the major risk factors for CVD -smoking, poor lipid profile, high systolic blood pressure, high fasting glucose, greater abdominal adiposity-as well as to a composite Metabolic Syndrome variable. Telomere length was related only to elevated stress hormones (catecholamines and cortisol). Thus, we propose that low leukocyte telomerase constitutes an early marker of CVD risk, possibly preceding shortened telomeres, that results in part from chronic stress arousal. Possible cellular mechanisms by which low telomerase may link stress and traditional risk factors to CVD are discussed. These findings may implicate telomerase as a novel and important mediator of the effects of psychological stress on physical health and disease. PMID:16298085

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

    PubMed

    Li, Ling-Jun; Ikram, Mohammad Kamran; Wong, Tien Yin

    2016-04-15

    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

  2. The Prevalence of Cardiovascular Disease Risk Factors and Obesity in Firefighters

    PubMed Central

    Smith, Denise L.; Fehling, Patricia C.; Frisch, Adam; Haller, Jeannie M.; Winke, Molly; Dailey, Michael W.

    2012-01-01

    Obesity is associated with increased risk of cardiovascular disease (CVD) mortality. CVD is the leading cause of duty-related death among firefighters, and the prevalence of obesity is a growing concern in the Fire Service. Methods. Traditional CVD risk factors, novel measures of cardiovascular health and a measurement of CVD were described and compared between nonobese and obese career firefighters who volunteered to participate in this cross-sectional study. Results. In the group of 116 men (mean age 43 ± 8 yrs), the prevalence of obesity was 51.7%. There were no differences among traditional CVD risk factors or the coronary artery calcium (CAC) score (criterion measure) between obese and nonobese men. However, significant differences in novel markers, including CRP, subendocardial viability ratio, and the ejection duration index, were detected. Conclusions. No differences in the prevalence of traditional CVD risk factors between obese and nonobese men were found. Additionally, CAC was similar between groups. However, there were differences in several novel risk factors, which warrant further investigation. Improved CVD risk identification among firefighters has important implications for both individual health and public safety. PMID:22888409

  3. Risk factors for cardiovascular disease in women: relationship to lipid peroxidation and oxidative stress.

    PubMed

    Castelao, J Esteban; Gago-Dominguez, Manuela

    2008-01-01

    Many risk factors that promote cardiovascular disease (CVD) have been identified. These include hypertension, hypercholesterolemia, diabetes, decreased estrogen in post-menopausal women, increased homocysteine, and cigarette smoking. It has recently become clear that a mechanism common to these risk factors is oxidative stress. CVD risk factors specific to women are parity, oophorectomy, pre-eclampsia, and menopause. There are several proposed mechanisms to explain these women-specific associations, such as reduced lifetime exposure to estrogen and insulin resistance, but the underlying mechanism is still unclear. One fact that did not receive much attention is the role of the oxidation hypothesis in these reproductive factors-CVD associations. In fact, pregnant, oophorectomized, and post-menopausal women exhibit higher levels of lipid peroxidation than non-pregnant, non-oophorectomized and pre-menopausal women, respectively. We propose that the increased levels of lipid peroxidation during these states are responsible, at least in part, for their increased risk of CVD. This review extends the concept of the oxidation hypothesis of CVD to reproductive risk factors in women. It also addresses the potential role of oxidative stress in the hyperthyroidism-CVD relationship, as hyperthyroidism is a common disorder that most frequently occurs in women. We also discuss how screening human populations for reactive oxygen species (ROS) levels could help identify groups with a high level of ROS that may be at risk of developing CVD. PMID:18308480

  4. Metallic Magnetic Calorimeters for Absolute Activity Measurement

    NASA Astrophysics Data System (ADS)

    Loidl, M.; Leblanc, E.; Rodrigues, M.; Bouchard, J.; Censier, B.; Branger, T.; Lacour, D.

    2008-05-01

    We present a prototype of metallic magnetic calorimeters that we are developing for absolute activity measurements of low energy emitting radionuclides. We give a detailed description of the realization of the prototype, containing an 55Fe source inside the detector absorber. We present the analysis of first data taken with this detector and compare the result of activity measurement with liquid scintillation counting. We also propose some ways for reducing the uncertainty on the activity determination with this new technique.

  5. Absolute photoionization cross sections of atomic oxygen

    NASA Technical Reports Server (NTRS)

    Samson, J. A. R.; Pareek, P. N.

    1985-01-01

    The absolute values of photoionization cross sections of atomic oxygen were measured from the ionization threshold to 120 A. An auto-ionizing resonance belonging to the 2S2P4(4P)3P(3Do, 3So) transition was observed at 479.43 A and another line at 389.97 A. The experimental data is in excellent agreement with rigorous close-coupling calculations that include electron correlations in both the initial and final states.

  6. Absolute photoionization cross sections of atomic oxygen

    NASA Technical Reports Server (NTRS)

    Samson, J. A. R.; Pareek, P. N.

    1982-01-01

    The absolute values of photoionization cross sections of atomic oxygen were measured from the ionization threshold to 120 A. An auto-ionizing resonance belonging to the 2S2P4(4P)3P(3Do, 3So) transition was observed at 479.43 A and another line at 389.97 A. The experimental data is in excellent agreement with rigorous close-coupling calculations that include electron correlations in both the initial and final states.

  7. Silicon Absolute X-Ray Detectors

    SciTech Connect

    Seely, John F.; Korde, Raj; Sprunck, Jacob; Medjoubi, Kadda; Hustache, Stephanie

    2010-06-23

    The responsivity of silicon photodiodes having no loss in the entrance window, measured using synchrotron radiation in the 1.75 to 60 keV range, was compared to the responsivity calculated using the silicon thickness measured using near-infrared light. The measured and calculated responsivities agree with an average difference of 1.3%. This enables their use as absolute x-ray detectors.

  8. Relative errors can cue absolute visuomotor mappings.

    PubMed

    van Dam, Loes C J; Ernst, Marc O

    2015-12-01

    When repeatedly switching between two visuomotor mappings, e.g. in a reaching or pointing task, adaptation tends to speed up over time. That is, when the error in the feedback corresponds to a mapping switch, fast adaptation occurs. Yet, what is learned, the relative error or the absolute mappings? When switching between mappings, errors with a size corresponding to the relative difference between the mappings will occur more often than other large errors. Thus, we could learn to correct more for errors with this familiar size (Error Learning). On the other hand, it has been shown that the human visuomotor system can store several absolute visuomotor mappings (Mapping Learning) and can use associated contextual cues to retrieve them. Thus, when contextual information is present, no error feedback is needed to switch between mappings. Using a rapid pointing task, we investigated how these two types of learning may each contribute when repeatedly switching between mappings in the absence of task-irrelevant contextual cues. After training, we examined how participants changed their behaviour when a single error probe indicated either the often-experienced error (Error Learning) or one of the previously experienced absolute mappings (Mapping Learning). Results were consistent with Mapping Learning despite the relative nature of the error information in the feedback. This shows that errors in the feedback can have a double role in visuomotor behaviour: they drive the general adaptation process by making corrections possible on subsequent movements, as well as serve as contextual cues that can signal a learned absolute mapping. PMID:26280315

  9. Absolute distance measurements by variable wavelength interferometry

    NASA Astrophysics Data System (ADS)

    Bien, F.; Camac, M.; Caulfield, H. J.; Ezekiel, S.

    1981-02-01

    This paper describes a laser interferometer which provides absolute distance measurements using tunable lasers. An active feedback loop system, in which the laser frequency is locked to the optical path length difference of the interferometer, is used to tune the laser wavelengths. If the two wavelengths are very close, electronic frequency counters can be used to measure the beat frequency between the two laser frequencies and thus to determine the optical path difference between the two legs of the interferometer.

  10. Does Sufficient Evidence Exist to Support a Causal Association between Vitamin D Status and Cardiovascular Disease Risk? An Assessment Using Hill’s Criteria for Causality

    PubMed Central

    Weyland, Patricia G.; Grant, William B.; Howie-Esquivel, Jill

    2014-01-01

    Serum 25-hydroxyvitamin D (25(OH)D) levels have been found to be inversely associated with both prevalent and incident cardiovascular disease (CVD) risk factors; dyslipidemia, hypertension and diabetes mellitus. This review looks for evidence of a causal association between low 25(OH)D levels and increased CVD risk. We evaluated journal articles in light of Hill’s criteria for causality in a biological system. The results of our assessment are as follows. Strength of association: many randomized controlled trials (RCTs), prospective and cross-sectional studies found statistically significant inverse associations between 25(OH)D levels and CVD risk factors. Consistency of observed association: most studies found statistically significant inverse associations between 25(OH)D levels and CVD risk factors in various populations, locations and circumstances. Temporality of association: many RCTs and prospective studies found statistically significant inverse associations between 25(OH)D levels and CVD risk factors. Biological gradient (dose-response curve): most studies assessing 25(OH)D levels and CVD risk found an inverse association exhibiting a linear biological gradient. Plausibility of biology: several plausible cellular-level causative mechanisms and biological pathways may lead from a low 25(OH)D level to increased risk for CVD with mediators, such as dyslipidemia, hypertension and diabetes mellitus. Experimental evidence: some well-designed RCTs found increased CVD risk factors with decreasing 25(OH)D levels. Analogy: the association between serum 25(OH)D levels and CVD risk is analogous to that between 25(OH)D levels and the risk of overall cancer, periodontal disease, multiple sclerosis and breast cancer. Conclusion: all relevant Hill criteria for a causal association in a biological system are satisfied to indicate a low 25(OH)D level as a CVD risk factor. PMID:25184368

  11. Absolute dosimetry for extreme-ultraviolet lithography

    NASA Astrophysics Data System (ADS)

    Berger, Kurt W.; Campiotti, Richard H.

    2000-06-01

    The accurate measurement of an exposure dose reaching the wafer on an extreme ultraviolet (EUV) lithographic system has been a technical challenge directly applicable to the evaluation of candidate EUV resist materials and calculating lithography system throughputs. We have developed a dose monitoring sensor system that can directly measure EUV intensities at the wafer plane of a prototype EUV lithographic system. This sensor system, located on the wafer stage adjacent to the electrostatic chuck used to grip wafers, operates by translating the sensor into the aerial image, typically illuminating an 'open' (unpatterned) area on the reticle. The absolute signal strength can be related to energy density at the wafer, and thus used to determine resist sensitivity, and the signal as a function of position can be used to determine illumination uniformity at the wafer plane. Spectral filtering to enhance the detection of 13.4 nm radiation was incorporated into the sensor. Other critical design parameters include the packaging and amplification technologies required to place this device into the space and vacuum constraints of a EUV lithography environment. We describe two approaches used to determine the absolute calibration of this sensor. The first conventional approach requires separate characterization of each element of the sensor. A second novel approach uses x-ray emission from a mildly radioactive iron source to calibrate the absolute response of the entire sensor system (detector and electronics) in a single measurement.

  12. Dietary Intake Is Related to Multifactor Cardiovascular Risk Score in Obese Boys

    PubMed Central

    Schumacher, Tracy L.; Burrows, Tracy L.; Cliff, Dylan P.; Jones, Rachel A.; Okely, Anthony D.; Baur, Louise A.; Morgan, Philip J.; Callister, Robin; Boggess, May M.; Collins, Clare E.

    2014-01-01

    Cardiovascular disease (CVD) originates in childhood and early identification of risk factors provides an early intervention opportunity. The aim was to identify children at higher risk using a CVD risk score, developed from factors known to cluster in childhood. Risk was scored as very high (≥97.5th centile), high (≥95th), moderate (≥90th) or threshold (<90th) using normal pediatric reference ranges for 10 common biomedical risk factors. These were summed in a multifactor CVD risk score and applied to a sample of 285 observations from 136 overweight Australian children (41% male, aged 7–12 years). Strength of associations between CVD risk score and individual biomedical and dietary variables were assessed using univariate logistic regression. High waist circumference (Odds Ratio: 5.48 [95% CI: 2.60–11.55]), body mass index (OR: 3.22 [1.98–5.26]), serum insulin (OR: 3.37 [2.56–4.42]) and triglycerides (OR: 3.02 [2.22–4.12]) were all significantly related to CVD risk score. High intakes of total fat (OR: 4.44 [1.19–16.60]), sugar (OR: 2.82 [1.54–5.15]) and carbohydrate (OR 1.75 [1.11–2.77]) were significantly related to CVD risk score in boys only. This multifactor CVD risk score could be a useful tool for researchers to identify elevated risk in children. Further research is warranted to examine sex-specific dietary factors related to CVD risk in children.

  13. Chronic Pain, Body Mass Index and Cardiovascular Disease Risk Factors: Tests of Moderation, Unique and Shared Relationships in the Study of Women's Health Across the Nation (SWAN)

    PubMed Central

    Burns, John W.; Quartana, Phillip J.; Bruehl, Stephen; Janssen, Imke; Dugan, Sheila A.; Appelhans, Bradley; Matthews, Karen A.; Kravitz, Howard M.

    2015-01-01

    Chronic pain may be related to cardiovascular disease (CVD) risk. The current study examined whether persistent bodily pain was related to cardiovascular disease risk factors, whether these effects were moderated by body mass index (BMI), and, if not, whether chronic pain accounted for unique variance in CVD risk factors. Participants were women (N=2135) in the Study of Women's Health Across the Nation. A High Pain Frequency variable (high pain in 0 through 4 assessments) was coded to reflect the frequency of high levels of bodily pain across the first 3 years of the study. Six CVD risk factors and BMI were measured at follow-up year 3. High Pain Frequency and BMI were correlated significantly with risk factors, although effects for the former were small. Hierarchical multiple regressions revealed High Pain Frequency × BMI interactions for 5 of 6 CVD risk factors. Dissecting the interactions revealed a similar pattern across 4 risk factors: for women with normal BMI, there was a “dose-response” in which increasing frequency of high pain revealed increasingly worse CVD risk factor levels, whereas for women with obese BMI, high pain frequency was unrelated to risk factors. For obese women, increasing frequency of high pain was associated with higher blood glucose. Although BMI is a well-established CVD risk factor, evaluation of CVD risk level may be improved by considering the incidence of persistent pain, particularly in normal weight women (BMI<25kg/m2) lower BMI. PMID:25427423

  14. Influence of growth pressure on filling 4H-SiC trenches by CVD method

    NASA Astrophysics Data System (ADS)

    Ji, Shiyang; Kojima, Kazutoshi; Kosugi, Ryoji; Saito, Shingo; Sakuma, Yuuki; Tanaka, Yasunori; Yoshida, Sadafumi; Himi, Hiroaki; Okumura, Hajime

    2016-01-01

    To construct a superjunction structure consisting of p/n columns, narrow stripe-shaped trenches (∼1.5 µm wide and ∼4.7 µm deep) preformed on an n+ 4H-SiC substrate were filled by the hot-wall CVD method using a conventional gas reaction system, SiH4:C3H8:H2. The influences of growth pressure on the coverage distribution of epilayers and the corresponding filling efficiency (the thickness ratio of epilayers on trench bottom and mesa top) were investigated. Two benefits of increasing the growth pressure from 10 to 38 kPa were found: one is the reduced growth around the mesa surface, which lessens the risk of void formation; the other is a high filling rate as well as an improved filling efficiency up to ∼7. By supplying source gases at high flow rates, a void-free trench filling with a filling rate of ∼1.3 µm/h was successfully achieved at 38 kPa.

  15. Successful comeback of the single-dose live oral cholera vaccine CVD 103-HgR.

    PubMed

    Herzog, Christian

    2016-01-01

    Effective and easy to administer cholera vaccines are in need more than ever, for at risk populations and travellers alike. In many parts of the world cholera is still endemic, causing outbreaks and constituting repeatedly serious public health problems. The oral live cholera vaccine CVD 103-HgR (Orochol, Mutachol), the first genetically modified organism (GMO) used as vaccine, was in its time (launched 1993, Switzerland) the ideal cholera vaccine: single-dose, protective efficacy of 80-100% against moderate to severe cholera, acting within 8 days and exhibiting excellent safety, indiscernible from placebo. However, there were strong headwinds: In the 1990s the indication for cholera vaccines was generally downplayed by experts and in 1997 the European Commission called for a moratorium of GMOs which blocked the registration in the European Union. Thus, demand for this vaccine remained low and in 2003 it was taken off the market for economic reasons. After a decade in obscurity it (Vaxchora) has resurfaced again, now produced in the U.S. and equipped with a U.S. FDA license (June 10, 2016). What had happened? This commentary gives a critical account of an almost unbelievable string of misadventures, emerging adverse circumstances and man-made failures which nearly killed this single-dose live oral cholera vaccine. The good news is that patience and persistence lead to success in the end, allowing good science to prevail for the benefit of those in need. PMID:27425792

  16. Optimization of a Wcl6 CVD System to Coat UO2 Powder with Tungsten

    NASA Technical Reports Server (NTRS)

    Belancik, Grace A.; Barnes, Marvin W.; Mireles, Omar; Hickman, Robert

    2015-01-01

    In order to achieve deep space exploration via Nuclear Thermal Propulsion (NTP), Marshall Space Flight Center (MSFC) is developing W-UO2 CERMET fuel elements, with focus on fabrication, testing, and process optimization. A risk of fuel loss is present due to the CTE mismatch between tungsten and UO2 in the W-60vol%UO2 fuel element, leading to high thermal stresses. This fuel loss can be reduced by coating the spherical UO2 particles with tungsten via H2/WCl6 reduction in a fluidized bed CVD system. Since the latest incarnation of the inverted reactor was completed, various minor modifications to the system design were completed, including an inverted frit sublimer. In order to optimize the parameters to achieve the desired tungsten coating thickness, a number of trials using surrogate HfO2 powder were performed. The furnace temperature was varied between 930 C and 1000degC, and the sublimer temperature was varied between 140 C and 200 C. Each trial lasted 73-82 minutes, with one lasting 205 minutes. A total of 13 trials were performed over the course of three months, two of which were re-coatings of previous trials. The powder samples were weighed before and after coating to roughly determine mass gain, and Scanning Electron Microscope (SEM) data was also obtained. Initial mass results indicated that the rate of layer deposition was lower than desired in all of the trials. SEM confirmed that while a uniform coating was obtained, the average coating thickness was 9.1% of the goal. The two re-coating trials did increase the thickness of the tungsten layer, but only to an average 14.3% of the goal. Therefore, the number of CVD runs required to fully coat one batch of material with the current configuration is not feasible for high production rates. Therefore, the system will be modified to operate with a negative pressure environment. This will allow for better gas mixing and more efficient heating of the substrate material, yielding greater tungsten coating per trial.

  17. Recovery of CVD Diamond Detectors using Laser Double Pulses

    SciTech Connect

    Dauffy, L S; Lerche, R A; Schmid, G J; Koch, J A; Silbenagel, C

    2005-09-27

    A 5 x 0.25 mm Chemical Vapor Deposited (CVD) diamond detector, with a voltage bias of + 250V, was excited by a 400 nm laser (3.1 eV photons) in order to study the saturation of the wafer and its associated electronics. In a first experiment, the laser beam energy was increased from a few tens of a pJ to about 100 {micro}J, and the signal from the diamond was recorded until full saturation of the detection system was achieved. Clear saturation of the detection system was observed at about 40 V, which corresponds with the expected saturation at 10% of the applied bias (250V). The results indicate that the interaction mechanism of the 3.1 eV photons in the diamond (E{sub bandgap} = 5.45 eV) is not a multi-photon process but is linked to the impurities and defects of the crystal. In a second experiment, the detector was irradiated by a saturating first laser pulse and then by a delayed laser pulse of equal or smaller amplitude with delays of 5, 10, and 20 ns. The results suggest that the diamond and associated electronics recover within 10 to 20 ns after a strong saturating pulse.

  18. The evaluation of radiation damage parameter for CVD diamond

    NASA Astrophysics Data System (ADS)

    Grilj, V.; Skukan, N.; Jakšić, M.; Pomorski, M.; Kada, W.; Kamiya, T.; Ohshima, T.

    2016-04-01

    There are a few different phenomenological approaches that aim to track the dependence of signal height in irradiated solid state detectors on the fluence of damaging particles. However, none of them are capable to provide a unique radiation hardness parameter that would reflect solely the material capability to withstand high radiation environment. To extract such a parameter for chemical vapor deposited (CVD) diamond, two different diamond detectors were irradiated with proton beams in MeV energy range and subjected afterwards to ion beam induced charge (IBIC) analysis. The change in charge collection efficiency (CCE) due to defects produced was investigated in context of a theoretical model that was developed on the basis of the adjoint method for linearization of the continuity equations of electrons and holes. Detailed modeling of measured data resulted with the first known value of the kσ product for diamond, where k represents the number of charge carriers' traps created per one simulated primary lattice vacancy and σ represents the charge carriers' capture cross section. As discussed in the text, this product could be considered as a true radiation damage parameter.

  19. Quantum Hall effect in polycrystalline CVD graphene: grain boundaries impact

    NASA Astrophysics Data System (ADS)

    Ribeiro-Palau, Rebeca; Lafont, Fabien; Schopfer, Felicien; Poirier, Wilfrid; Bouchiat, Vincent; Han, Zhen; Cresti, Alessandro; Cummings, Aron; Roche, Stephan

    2014-03-01

    It was demonstrated by Janssen et al. (New J. Phys. 2011) that graphene could surpass GaAs for quantum Hall resistance standards with an accuracy better than 10-10. Graphene should render possible the realization of a standard operating at T > 4 K and B < 4 T, easing its dissemination towards industry. To materialize this goal scalable graphene with outstanding electronic transport properties is required. We present measurements performed in large area Hall bars made of polycrystalline CVD graphene on Si/SiO2, with a carrier mobility of 0.6 T-1. Even at 20.2 T and 300 mK, the Hall resistance plateaus are insufficiently quantized at ν = +/- 2 and +/- 6 . This is due to a high dissipation manifested by a longitudinal resistance which does not drop to zero. We pointed out unusual power-law temperature dependencies of Rxx and an exponential magnetic field dependence. We do not observe the common thermally activated or VRH behaviors. This can be attributed to the grain boundaries in the sample that short-circuit the edge states, as supported by our numerical simulations. This reveals new and peculiar aspects of the quantum Hall effect in polycrystalline systems. Another unexpected feature is the observation of the ν = 0 and 1 states in such low mobility systems.

  20. High Efficiency CVD Graphene-lead (Pb) Cooper Pair Splitter.

    PubMed

    Borzenets, I V; Shimazaki, Y; Jones, G F; Craciun, M F; Russo, S; Yamamoto, M; Tarucha, S

    2016-01-01

    Generation and manipulation of quantum entangled electrons is an important concept in quantum mechanics, and necessary for advances in quantum information processing; but not yet established in solid state systems. A promising device is a superconductor-two quantum dots Cooper pair splitter. Early nanowire based devices, while efficient, are limited in scalability and further electron manipulation. We demonstrate an optimized, high efficiency, CVD grown graphene-based Cooper pair splitter. Our device is designed to induce superconductivity in graphene via the proximity effect, resulting in both a large superconducting gap Δ = 0.5 meV, and coherence length ξ = 200 nm. The flat nature of the device lowers parasitic capacitance, increasing charging energy EC. Our design also eases geometric restrictions and minimizes output channel separation. As a result we measure a visibility of up to 86% and a splitting efficiency of up to 62%. This will pave the way towards near unity efficiencies, long distance splitting, and post-splitting electron manipulation. PMID:26971450

  1. High Efficiency CVD Graphene-lead (Pb) Cooper Pair Splitter

    NASA Astrophysics Data System (ADS)

    Borzenets, I. V.; Shimazaki, Y.; Jones, G. F.; Craciun, M. F.; Russo, S.; Yamamoto, M.; Tarucha, S.

    2016-03-01

    Generation and manipulation of quantum entangled electrons is an important concept in quantum mechanics, and necessary for advances in quantum information processing; but not yet established in solid state systems. A promising device is a superconductor-two quantum dots Cooper pair splitter. Early nanowire based devices, while efficient, are limited in scalability and further electron manipulation. We demonstrate an optimized, high efficiency, CVD grown graphene-based Cooper pair splitter. Our device is designed to induce superconductivity in graphene via the proximity effect, resulting in both a large superconducting gap Δ = 0.5 meV, and coherence length ξ = 200 nm. The flat nature of the device lowers parasitic capacitance, increasing charging energy EC. Our design also eases geometric restrictions and minimizes output channel separation. As a result we measure a visibility of up to 86% and a splitting efficiency of up to 62%. This will pave the way towards near unity efficiencies, long distance splitting, and post-splitting electron manipulation.

  2. Experimental Study of the Flow in a Rotating CVD Reactor

    NASA Astrophysics Data System (ADS)

    Wong, Sun; Meng, Jiandong; Jaluria, Yogesh

    2013-11-01

    An experimental model is developed to study the rotating, vertical, impinging chemical vapor deposition reactor. Deposition occurs only when the system has enough thermal energy. Therefore, understanding the fluid flow and thermal characteristics of the system would provide a good basis to model the thin film deposition process. The growth rate and the uniformity of the film are the two most important factors in the CVD process and these depend strongly on the flow and the thermal transport within the system. Operating parameters, such as inflow velocity, susceptor temperature and rotational speed, are used to create different design simulations. Fluid velocities and temperature distributions are recorded to obtain the effects of different operating parameters. Velocities are recorded by using a rotameter and a hot wire anemometer. The temperatures are recorded by using thermocouples and an infrared thermometer. The effects of buoyancy and rotation are examined. The expermental study is also coupled with a numerical study for validation of the numerical model and to expand the domain. Comparisons between the two models are presented, indicating fair agreement. The numerical model also includes simulation of Gallium Nitride (GaN) thin film deposition. This simulation thus includes mass transport and gas kinetics, along with the flow and heat transfer within the system. A three dimensional simulation is needed due to the rotation of the susceptor. The results obtained as well as the underlying fluid flow phenomena are discussed.

  3. Excimer Laser Beam Analyzer Based on CVD Diamond

    NASA Astrophysics Data System (ADS)

    Girolami, Marco; Salvatori, Stefano; Conte, Gennaro

    2010-11-01

    1-D and 2-D detector arrays have been realized on CVD-diamond. The relatively high resistivity of diamond in the dark allowed the fabrication of photoconductive "sandwich" strip (1D) or pixel (2D) detectors: a semitransparent light-receiving back-side contact was used for detector biasing. Cross-talk between pixels was limited by using intermediate guard contacts connected at the same ground potential of the pixels. Each pixel photocurrent was conditioned by a read-out electronics composed by a high sensitive integrator and a Σ-Δ ADC converter. The overall 500 μs conversion time allowed a data acquisition rate up to 2 kSPS. The measured fast photoresponse of the samples in the ns time regime suggests to use the proposed devices for fine tuning feedback of high-power pulsed-laser cavities, whereas solar-blindness guarantees high performance in UV beam diagnostics also under high intensity background illumination. Offering unique properties in terms of thermal conductivity and visible-light transparency, diamond represents one of the most suitable candidate for the detection of high-power UV laser emission. The technology of laser beam profiling is evolving with the increase of excimer lasers applications that span from laser-cutting to VLSI and MEMS technologies. Indeed, to improve emission performances, fine tuning of the laser cavity is required. In such a view, the development of a beam-profiler, able to work in real-time between each laser pulse, is mandatory.

  4. Atomistic modelling of CVD synthesis of carbon nanotubes and graphene

    NASA Astrophysics Data System (ADS)

    Elliott, James A.; Shibuta, Yasushi; Amara, Hakim; Bichara, Christophe; Neyts, Erik C.

    2013-07-01

    We discuss the synthesis of carbon nanotubes (CNTs) and graphene by catalytic chemical vapour deposition (CCVD) and plasma-enhanced CVD (PECVD), summarising the state-of-the-art understanding of mechanisms controlling their growth rate, chiral angle, number of layers (walls), diameter, length and quality (defects), before presenting a new model for 2D nucleation of a graphene sheet from amorphous carbon on a nickel surface. Although many groups have modelled this process using a variety of techniques, we ask whether there are any complementary ideas emerging from the different proposed growth mechanisms, and whether different modelling techniques can give the same answers for a given mechanism. Subsequently, by comparing the results of tight-binding, semi-empirical molecular orbital theory and reactive bond order force field calculations, we demonstrate that graphene on crystalline Ni(111) is thermodynamically stable with respect to the corresponding amorphous metal and carbon structures. Finally, we show in principle how a complementary heterogeneous nucleation step may play a key role in the transformation from amorphous carbon to graphene on the metal surface. We conclude that achieving the conditions under which this complementary crystallisation process can occur may be a promising method to gain better control over the growth processes of both graphene from flat metal surfaces and CNTs from catalyst nanoparticles.

  5. Fabrication of graphene-based films using remote plasma CVD

    NASA Astrophysics Data System (ADS)

    Hiramatsu, Mineo; Tsukada, Ryosuke; Kashima, Yohei; Naito, Masateru; Kondo, Hiroki; Hori, Masaru

    2012-10-01

    Plasma-enhanced CVD (PECVD) employing methane/hydrogen gases has been used to grow diamond, diamond-like carbon, and carbon nanotubes. In the case of microwave PECVD with methane/hydrogen system without catalyst nanoparticles at temperatures of 700--850 ^oC, where the substrate is exposed to the plasma, vertical nano-graphenes and carbon nanoflakes have been easily grown even on Cu substrate due to the ion bombardment and local electric field forces. In this work, we demonstrate the synthesis of planar few-layer graphene-based film using PECVD with remote plasma configuration. In the case using microwave plasma of cylindrical resonant cavity type, by simply installing grounded grid over the substrate plate for obtaining remote plasma configuration, we have successfully fabricated graphene-based films on Cu substrate, which was confirmed by the Raman spectrum and SEM image of deposit. Similar method will be applied to other plasmas such as low-pressure inductively coupled plasma, in order to verify the effectiveness of remote plasma configuration for the growth of planar graphene using PECVD technique. We will discuss the planar graphene growth mechanism in terms of precursors and their surface reaction.

  6. Atomistic modelling of CVD synthesis of carbon nanotubes and graphene.

    PubMed

    Elliott, James A; Shibuta, Yasushi; Amara, Hakim; Bichara, Christophe; Neyts, Erik C

    2013-08-01

    We discuss the synthesis of carbon nanotubes (CNTs) and graphene by catalytic chemical vapour deposition (CCVD) and plasma-enhanced CVD (PECVD), summarising the state-of-the-art understanding of mechanisms controlling their growth rate, chiral angle, number of layers (walls), diameter, length and quality (defects), before presenting a new model for 2D nucleation of a graphene sheet from amorphous carbon on a nickel surface. Although many groups have modelled this process using a variety of techniques, we ask whether there are any complementary ideas emerging from the different proposed growth mechanisms, and whether different modelling techniques can give the same answers for a given mechanism. Subsequently, by comparing the results of tight-binding, semi-empirical molecular orbital theory and reactive bond order force field calculations, we demonstrate that graphene on crystalline Ni(111) is thermodynamically stable with respect to the corresponding amorphous metal and carbon structures. Finally, we show in principle how a complementary heterogeneous nucleation step may play a key role in the transformation from amorphous carbon to graphene on the metal surface. We conclude that achieving the conditions under which this complementary crystallisation process can occur may be a promising method to gain better control over the growth processes of both graphene from flat metal surfaces and CNTs from catalyst nanoparticles. PMID:23774798

  7. High Efficiency CVD Graphene-lead (Pb) Cooper Pair Splitter

    PubMed Central

    Borzenets, I. V.; Shimazaki, Y.; Jones, G. F.; Craciun, M. F.; Russo, S.; Yamamoto, M.; Tarucha, S.

    2016-01-01

    Generation and manipulation of quantum entangled electrons is an important concept in quantum mechanics, and necessary for advances in quantum information processing; but not yet established in solid state systems. A promising device is a superconductor-two quantum dots Cooper pair splitter. Early nanowire based devices, while efficient, are limited in scalability and further electron manipulation. We demonstrate an optimized, high efficiency, CVD grown graphene-based Cooper pair splitter. Our device is designed to induce superconductivity in graphene via the proximity effect, resulting in both a large superconducting gap Δ = 0.5 meV, and coherence length ξ = 200 nm. The flat nature of the device lowers parasitic capacitance, increasing charging energy EC. Our design also eases geometric restrictions and minimizes output channel separation. As a result we measure a visibility of up to 86% and a splitting efficiency of up to 62%. This will pave the way towards near unity efficiencies, long distance splitting, and post-splitting electron manipulation. PMID:26971450

  8. Carbon Nanotubes Grown By CVD in Various Conditions

    NASA Technical Reports Server (NTRS)

    Zhu, S.; Su, C.; Cochrane, J. C.; Lehoczky. S. L.; Muntele, I.; Ila, D.; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    Since the superior properties of multi-wall carbon nanotubes (MWCNT) could be used in numerous devices such as electronics and sensors, many efforts have been engaged in synthesizing particular structural or dimensional MWCNT. This presentation will illustrate MWCNT synthesized on silicon substrates by thermal CVD. On the substrate, an array of catalysts is coated using sputtering deposition. A thin Ti buffer layer is also coated on some Si substrates prior to depositing catalyst particles. Nickel, cobalt or iron transition metals are used as catalysts for the MWCNT growth. Since the diameter of MWCNT depends on the size of catalyst particles, the catalyst particle size is investigated after annealed at various temperatures. MWCNT are grown on the substrate in the temperature range of 700 to 1000 C and the pressure range of 100 torr to one atmosphere. Methane and hydrogen gases with methane content of 10% to 100% are used for the MWCNT synthesis. Morphology, length and diameter of these MWCNT are determined by scanning electron microscopy and Raman spectroscopy. The detailed results of syntheses and characterizations will be discussed in the presentation.

  9. Carbon Nanotubes Growth by CVD on Graphite Fibers

    NASA Technical Reports Server (NTRS)

    Zhu, Shen; Su, Ching-Hua; Cochrane, J. C.; Lehoczky, S. L.; Muntele, I.; Ila, D.; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    Due to the superior electrical and mechanical properties of carbon nanotubes (CNT), synthesizing CNT on various substances for electronics devices and reinforced composites have been engaged in many efforts for applications. This presentation will illustrate CNT synthesized on graphite fibers by thermal CVD. On the fiber surface, iron nanoparticles as catalysts for CNT growth are coated. The growth temperature ranges from 600 to 1000 C and the pressure ranges from 100 Torr to one atmosphere. Methane and hydrogen gases with methane content of 10% to 100% are used for the CNT synthesis. At high growth temperatures (greater than or equal to 900 C), the rapid inter-diffusion of the transition metal iron on the graphite surface results in the rough fiber surface without any CNT grown on it. When the growth temperature is relative low (650-800 C), CNT with catalytic particles on the nanotube top ends are fabricated on the graphite surface. (Methane and hydrogen gases with methane content of 10% to 100% are used for the CNT synthesis.) (By measuring the samples) Using micro Raman spectroscopy in the breath mode region, single-walled or multi-walled CNT (MWCNT), depending on growth concentrations, are found. Morphology, length and diameter of these MWCNT are determined by scanning electron microscopy and Raman spectroscopy. The detailed results of syntheses and characterizations will be discussed in the presentation.

  10. Carbon Nanotubes Growth by CVD in Various Conditions

    NASA Technical Reports Server (NTRS)

    Zhu, S.; Su, C. H.; Cochrane, J. C.; Lehoczky, S. L.; Gorti, S.; Muntele, I.; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    Since the superior properties of multi-wall carbon nanotubes (MWCNT could be used in numerous devices such as electronics and sensors, many efforts have been engaged in synthesizing particular structural or dimensional MWCNT. This presentation will illustrate MWCNT synthesized on silicon substrates by thermal CVD. On the substrate, an array of catalysts is coated using sputtering deposition. A thin Ti buffer layer is also coated on some Si substrates prior to depositing catalyst particles. Nickel, cobalt or iron transition metals are used as catalysts for the MWCNT growth. Since the diameter of MWCNT depends on the size of catalyst particles, the catalyst particle size is investigated after annealed at various temperatures. MWCNT are grown on the substrate in the temperature range of 700 to 1000 C and the pressure range of 100 torr to one atmosphere. Methane and hydrogen gases with methane content of 10% to 100% are used for the MWCNT synthesis. Morphology, length and diameter of these MWCNT are determined by scanning electron microscopy and Raman spectroscopy. The detailed results of syntheses and characterizations will be discussed in the presentation.

  11. Vitamin D nutritional status and the risk for cardiovascular disease

    PubMed Central

    LIU, MIN; LI, XIANCHI; SUN, RONGRONG; ZENG, YI; CHEN, SHUANG; ZHANG, PEIYING

    2016-01-01

    Cardiovascular disease (CVD) is the leading cause of morbidity and mortality. CVD has a significant impact on health care systems worldwide and over 23 million individuals are expected to succumb to the disease by 2030. Early onset of atherosclerosis in childhood along with other risk factors of CVD, including elevated circulating lipids, have been shown to persist in adulthood and lead to CVD. Vitamin D deficiency is considered a risk factor for the pathogenesis of CVD, with childhood nutritional status of vitamin D being an important determinant of the development of CVD. Low levels of 25-hydroxyvitamin D can arise due to reduced intake as well as geographical location, and other diseases/conditions such as chronic kidney disease and obesity. Childhood vitamin D deficiency can progress and lead to atherosclerosis and other CVDs in adulthood. Early intervention with vitamin D supplementation is an ideal approach towards preventive therapy. However, there is no clear consensus regarding the role of vitamin D in childhood CVD. In the present study, we reviewed the available evidence in favor of and against such a role for this vitamin. PMID:27073421

  12. Enhanced thermal conductivity of CVD SiC via beryllium and boron dopings

    SciTech Connect

    Kowbel, W.; Gao, F.; Withers, J.C.

    1995-10-01

    SiC-SiC composites exhibit excellent mechanical and corrosion properties, which are desired for a variety of advanced applications including fusion reactors, heat exchangers and advanced turbine engines. However, SiC-SiC composites fabricated by the CVI methods have unacceptably low through-the-thickness thermal conductivity, which limits their use in these applications. CVD SiC co-deposition with either beryllium or boron compounds significantly enhanced the thermal conductivity of CVD SiC at temperatures up to 1,000 C. Results pertinent to the doping processes and the measured thermal conductivity of doped CVD SiC are reported. Mechanisms for the enhanced thermal conductivity of the CVD SiC are discussed based on the microstructural characteristics of the doped specimens.

  13. A platform for large-scale graphene electronics--CVD growth of single-layer graphene on CVD-grown hexagonal boron nitride.

    PubMed

    Wang, Min; Jang, Sung Kyu; Jang, Won-Jun; Kim, Minwoo; Park, Seong-Yong; Kim, Sang-Woo; Kahng, Se-Jong; Choi, Jae-Young; Ruoff, Rodney S; Song, Young Jae; Lee, Sungjoo

    2013-05-21

    Direct chemical vapor deposition (CVD) growth of single-layer graphene on CVD-grown hexagonal boron nitride (h-BN) film can suggest a large-scale and high-quality graphene/h-BN film hybrid structure with a defect-free interface. This sequentially grown graphene/h-BN film shows better electronic properties than that of graphene/SiO2 or graphene transferred on h-BN film, and suggests a new promising template for graphene device fabrication. PMID:23576235

  14. Statin combination therapy and cardiovascular risk reduction.

    PubMed

    Toth, Peter P; Farnier, Michel; Tomassini, Joanne E; Foody, JoAnne M; Tershakovec, Andrew M

    2016-05-01

    In numerous clinical trials, lowering LDL-C with statin therapy has been demonstrated to reduce the risk of cardiovascular disease (CVD) in primary and secondary prevention settings. Guidelines recommend statins for first-line therapy in cholesterol-lowering management of patients with CVD risk. Despite increased statin monotherapy use over the last decade, a number of patients with high CVD risk do not achieve optimal LDL-C lowering. Guidelines recommend consideration of statin combination therapy with nonstatin agents for these patients. However, combination therapy approaches have been hampered by neutral findings. Recently, ezetimibe added to simvastatin therapy reduced cardiovascular events in acute coronary syndrome patients, more than simvastatin alone. This article provides an overview of various agents in combination with statin therapy on cardiovascular outcomes. Other lipid-lowering agents in development, including PCSK9 and CETP inhibitors in development, are also described. PMID:27079178

  15. CVD Diamond, DLC, and c-BN Coatings for Solid Film Lubrication

    NASA Technical Reports Server (NTRS)

    Miyoshi, Kazuhisa

    1998-01-01

    When the main criteria for judging coating performance were coefficient of friction and wear rate, which had to be less than 0.1 and 10(exp -6) mm(exp 3)/N-m, respectively, carbon- and nitrogen-ion-implanted, fine-grain CVD diamond and DLC ion beam deposited on fine-grain CVD diamond met the requirements regardless of environment (vacuum, nitrogen, and air).

  16. CVD Diamond, DLC, and c-BN Coatings for Solid Film Lubrication

    NASA Technical Reports Server (NTRS)

    Miyoshi, Kazuhisa; Murakawa, Masao; Watanabe, Shuichi; Takeuchi, Sadao; Miyake, Shojiro; Wu, Richard L. C.

    1998-01-01

    The main criteria for judging coating performance were coefficient of friction and wear rate, which had to be less than 0.1 and 10(exp -6) cubic MM /(N*m), respectively. Carbon- and nitrogen-ion-implanted, fine-grain, chemical-vapor-deposited (CVD) diamond and diamondlike carbon (DLC) ion beam deposited on fine-grain CVD diamond met the criteria regardless of environment (vacuum, nitrogen, and air).

  17. Tribological Characteristics and Applications of Superhard Coatings: CVD Diamond, DLC, and c-BN

    NASA Technical Reports Server (NTRS)

    Miyoshi, Kazuhisa; Murakawa, Masao; Watanabe, Shuichi; Takeuchi, Sadao; Wu, Richard L. C.

    1999-01-01

    Results of fundamental research on the tribological properties of chemical-vapor-deposited (CVD) diamond, diamondlike carbon, and cubic boron nitride films in sliding contact with CVD diamond in ultrahigh vacuum, dry nitrogen, humid air, and water are discussed. Furthermore, the actual and potential applications of the three different superhard coatings in the field of tribology technology, particularly for wear parts and tools, are reviewed.

  18. Cardiovascular risk assessment in diabetes mellitus: comparison of the general Framingham risk profile versus the World Health Organization/International Society of Hypertension risk prediction charts in Arabs--clinical implications.

    PubMed

    Al-Lawati, Jawad A; Barakat, Mohammed N; Al-Lawati, Najla A; Al-Maskari, Masoud Y; Elsayed, Medhat K; Mikhailidis, Dimitri P; Al-Zakwani, Ibrahim S

    2013-07-01

    We estimated the prevalence of cardiovascular disease (CVD) risk and its clinical implications among 1 110 Omani patients with type 2 diabetes mellitus (DM) using 2 different CVD risk tools: the general Framingham risk profile (GFRP) and the joint World Health Organization/International Society of Hypertension (WHO/ISH) risk prediction charts. The GFRP tool identified higher proportion of patients compared with joint WHO/ISH tool at 10-year CVD risk 10% to <20% and at 20% to <30%. At CVD risk ≥30%, both assessment tools identified similar proportions of patients (22% vs 24%; P=.120). Compared with WHO/ISH charts, the GFRP identified almost double the number of men eligible for aspirin treatment at CVD risk thresholds of ≥10% (86% vs 43%). In women, the proportions were, 66% and 45%, respectively. For statins, the figures were, 60% and 37%, for men and 28% and 36%, for women. In conclusion, the GFRP overestimates the number of patients eligible for primary prevention of CVD compared with the joint WHO/ISH method. PMID:22942129

  19. Clock time is absolute and universal

    NASA Astrophysics Data System (ADS)

    Shen, Xinhang

    2015-09-01

    A critical error is found in the Special Theory of Relativity (STR): mixing up the concepts of the STR abstract time of a reference frame and the displayed time of a physical clock, which leads to use the properties of the abstract time to predict time dilation on physical clocks and all other physical processes. Actually, a clock can never directly measure the abstract time, but can only record the result of a physical process during a period of the abstract time such as the number of cycles of oscillation which is the multiplication of the abstract time and the frequency of oscillation. After Lorentz Transformation, the abstract time of a reference frame expands by a factor gamma, but the frequency of a clock decreases by the same factor gamma, and the resulting multiplication i.e. the displayed time of a moving clock remains unchanged. That is, the displayed time of any physical clock is an invariant of Lorentz Transformation. The Lorentz invariance of the displayed times of clocks can further prove within the framework of STR our earth based standard physical time is absolute, universal and independent of inertial reference frames as confirmed by both the physical fact of the universal synchronization of clocks on the GPS satellites and clocks on the earth, and the theoretical existence of the absolute and universal Galilean time in STR which has proved that time dilation and space contraction are pure illusions of STR. The existence of the absolute and universal time in STR has directly denied that the reference frame dependent abstract time of STR is the physical time, and therefore, STR is wrong and all its predictions can never happen in the physical world.

  20. Achieving Climate Change Absolute Accuracy in Orbit

    NASA Technical Reports Server (NTRS)

    Wielicki, Bruce A.; Young, D. F.; Mlynczak, M. G.; Thome, K. J; Leroy, S.; Corliss, J.; Anderson, J. G.; Ao, C. O.; Bantges, R.; Best, F.; Bowman, K.; Brindley, H.; Butler, J. J.; Collins, W.; Dykema, J. A.; Doelling, D. R.; Feldman, D. R.; Fox, N.; Huang, X.; Holz, R.; Huang, Y.; Jennings, D.; Jin, Z.; Johnson, D. G.; Jucks, K.; Kato, S.; Kratz, D. P.; Liu, X.; Lukashin, C.; Mannucci, A. J.; Phojanamongkolkij, N.; Roithmayr, C. M.; Sandford, S.; Taylor, P. C.; Xiong, X.

    2013-01-01

    The Climate Absolute Radiance and Refractivity Observatory (CLARREO) mission will provide a calibration laboratory in orbit for the purpose of accurately measuring and attributing climate change. CLARREO measurements establish new climate change benchmarks with high absolute radiometric accuracy and high statistical confidence across a wide range of essential climate variables. CLARREO's inherently high absolute accuracy will be verified and traceable on orbit to Système Internationale (SI) units. The benchmarks established by CLARREO will be critical for assessing changes in the Earth system and climate model predictive capabilities for decades into the future as society works to meet the challenge of optimizing strategies for mitigating and adapting to climate change. The CLARREO benchmarks are derived from measurements of the Earth's thermal infrared spectrum (5-50 micron), the spectrum of solar radiation reflected by the Earth and its atmosphere (320-2300 nm), and radio occultation refractivity from which accurate temperature profiles are derived. The mission has the ability to provide new spectral fingerprints of climate change, as well as to provide the first orbiting radiometer with accuracy sufficient to serve as the reference transfer standard for other space sensors, in essence serving as a "NIST [National Institute of Standards and Technology] in orbit." CLARREO will greatly improve the accuracy and relevance of a wide range of space-borne instruments for decadal climate change. Finally, CLARREO has developed new metrics and methods for determining the accuracy requirements of climate observations for a wide range of climate variables and uncertainty sources. These methods should be useful for improving our understanding of observing requirements for most climate change observations.

  1. Cardiovascular risk factors following renal transplant

    PubMed Central

    Neale, Jill; Smith, Alice C

    2015-01-01

    Kidney transplantation is the gold-standard treatment for many patients with end-stage renal disease. Renal transplant recipients (RTRs) remain at an increased risk of fatal and non-fatal cardiovascular (CV) events compared to the general population, although rates are lower than those patients on maintenance haemodialysis. Death with a functioning graft is most commonly due to cardiovascular disease (CVD) and therefore this remains an important therapeutic target to prevent graft failure. Conventional CV risk factors such as diabetes, hypertension and renal dysfunction remain a major influence on CVD in RTRs. However it is now recognised that the morbidity and mortality from CVD are not entirely accounted for by these traditional risk-factors. Immunosuppression medications exert a deleterious effect on many of these well-recognised contributors to CVD and are known to exacerbate the probability of developing diabetes, graft dysfunction and hypertension which can all lead on to CVD. Non-traditional CV risk factors such as inflammation and anaemia have been strongly linked to increased CV events in RTRs and should be considered alongside those which are classified as conventional. This review summarises what is known about risk-factors for CVD in RTRs and how, through identification of those which are modifiable, outcomes can be improved. The overall CV risk in RTRs is likely to be multifactorial and a complex interaction between the multiple traditional and non-traditional factors; further studies are required to determine how these may be modified to enhance survival and quality of life in this unique population. PMID:26722646

  2. Cardiovascular risk in climacteric women: focus on diet.

    PubMed

    Hernández-Angeles, C; Castelo-Branco, C

    2016-06-01

    A literature search was made using PubMed. The proportion of postmenopausal women has been continually increasing because of enhanced life expectancy. However, accompanying this trend, there is an observed increase in mortality due to cardiovascular disease (CVD). All over the world, obesity rates are increasing and this fact is associated with expanded rates of hypertension, dyslipidemia, and diabetes. Many of these well-known risk factors for CVD can be modified by lifestyle changes. For this reason, nutritional strategies to prevent CVD in this population should be a primary objective for health-care providers. Any attempt at lifestyle modification should include behavioral changes and the implementation of healthy diets and physical activity. The Mediterranean diet is comparable with other interventions such as aspirin, statins, physical activity, and even antihypertensives in terms of reducing the risk of CVD morbidity, mortality and events. The aim of this review is to analyze the effect of dietary advice on postmenopausal women's health. PMID:27112972

  3. The National Geodetic Survey absolute gravity program

    NASA Astrophysics Data System (ADS)

    Peter, George; Moose, Robert E.; Wessells, Claude W.

    1989-03-01

    The National Geodetic Survey absolute gravity program will utilize the high precision afforded by the JILAG-4 instrument to support geodetic and geophysical research, which involves studies of vertical motions, identification and modeling of other temporal variations, and establishment of reference values. The scientific rationale of these objectives is given, the procedures used to collect gravity and environmental data in the field are defined, and the steps necessary to correct and remove unwanted environmental effects are stated. In addition, site selection criteria, methods of concomitant environmental data collection and relative gravity observations, and schedule and logistics are discussed.

  4. An absolute radius scale for Saturn's rings

    NASA Technical Reports Server (NTRS)

    Nicholson, Philip D.; Cooke, Maren L.; Pelton, Emily

    1990-01-01

    Radio and stellar occultation observations of Saturn's rings made by the Voyager spacecraft are discussed. The data reveal systematic discrepancies of almost 10 km in some parts of the rings, limiting some of the investigations. A revised solution for Saturn's rotation pole has been proposed which removes the discrepancies between the stellar and radio occultation profiles. Corrections to previously published radii vary from -2 to -10 km for the radio occultation, and +5 to -6 km for the stellar occultation. An examination of spiral density waves in the outer A Ring supports that the revised absolute radii are in error by no more than 2 km.

  5. Characterization of the DARA solar absolute radiometer

    NASA Astrophysics Data System (ADS)

    Finsterle, W.; Suter, M.; Fehlmann, A.; Kopp, G.

    2011-12-01

    The Davos Absolute Radiometer (DARA) prototype is an Electrical Substitution Radiometer (ESR) which has been developed as a successor of the PMO6 type on future space missions and ground based TSI measurements. The DARA implements an improved thermal design of the cavity detector and heat sink assembly to minimize air-vacuum differences and to maximize thermal symmetry of measuring and compensating cavity. The DARA also employs an inverted viewing geometry to reduce internal stray light. We will report on the characterization and calibration experiments which were carried out at PMOD/WRC and LASP (TRF).

  6. Absolute calibration of the Auger fluorescence detectors

    SciTech Connect

    Bauleo, P.; Brack, J.; Garrard, L.; Harton, J.; Knapik, R.; Meyhandan, R.; Rovero, A.C.; Tamashiro, A.; Warner, D.

    2005-07-01

    Absolute calibration of the Pierre Auger Observatory fluorescence detectors uses a light source at the telescope aperture. The technique accounts for the combined effects of all detector components in a single measurement. The calibrated 2.5 m diameter light source fills the aperture, providing uniform illumination to each pixel. The known flux from the light source and the response of the acquisition system give the required calibration for each pixel. In the lab, light source uniformity is studied using CCD images and the intensity is measured relative to NIST-calibrated photodiodes. Overall uncertainties are presently 12%, and are dominated by systematics.

  7. Absolute angular positioning in ultrahigh vacuum

    SciTech Connect

    Schief, H.; Marsico, V.; Kern, K.

    1996-05-01

    Commercially available angular resolvers, which are routinely used in machine tools and robotics, are modified and adapted to be used under ultrahigh-vacuum (UHV) conditions. They provide straightforward and reliable measurements of angular positions for any kind of UHV sample manipulators. The corresponding absolute reproducibility is on the order of 0.005{degree}, whereas the relative resolution is better than 0.001{degree}, as demonstrated by high-resolution helium-reflectivity measurements. The mechanical setup and possible applications are discussed. {copyright} {ital 1996 American Institute of Physics.}

  8. Absolute method of measuring magnetic susceptibility

    USGS Publications Warehouse

    Thorpe, A.; Senftle, F.E.

    1959-01-01

    An absolute method of standardization and measurement of the magnetic susceptibility of small samples is presented which can be applied to most techniques based on the Faraday method. The fact that the susceptibility is a function of the area under the curve of sample displacement versus distance of the magnet from the sample, offers a simple method of measuring the susceptibility without recourse to a standard sample. Typical results on a few substances are compared with reported values, and an error of less than 2% can be achieved. ?? 1959 The American Institute of Physics.

  9. Absolute Priority for a Vehicle in VANET

    NASA Astrophysics Data System (ADS)

    Shirani, Rostam; Hendessi, Faramarz; Montazeri, Mohammad Ali; Sheikh Zefreh, Mohammad

    In today's world, traffic jams waste hundreds of hours of our life. This causes many researchers try to resolve the problem with the idea of Intelligent Transportation System. For some applications like a travelling ambulance, it is important to reduce delay even for a second. In this paper, we propose a completely infrastructure-less approach for finding shortest path and controlling traffic light to provide absolute priority for an emergency vehicle. We use the idea of vehicular ad-hoc networking to reduce the imposed travelling time. Then, we simulate our proposed protocol and compare it with a centrally controlled traffic light system.

  10. Gene-centric Association Signals for Lipids and Apolipoproteins Identified via the HumanCVD BeadChip

    PubMed Central

    Talmud, Philippa J.; Drenos, Fotios; Shah, Sonia; Shah, Tina; Palmen, Jutta; Verzilli, Claudio; Gaunt, Tom R.; Pallas, Jacky; Lovering, Ruth; Li, Kawah; Casas, Juan Pablo; Sofat, Reecha; Kumari, Meena; Rodriguez, Santiago; Johnson, Toby; Newhouse, Stephen J.; Dominiczak, Anna; Samani, Nilesh J.; Caulfield, Mark; Sever, Peter; Stanton, Alice; Shields, Denis C.; Padmanabhan, Sandosh; Melander, Olle; Hastie, Claire; Delles, Christian; Ebrahim, Shah; Marmot, Michael G.; Smith, George Davey; Lawlor, Debbie A.; Munroe, Patricia B.; Day, Ian N.; Kivimaki, Mika; Whittaker, John; Humphries, Steve E.; Hingorani, Aroon D.

    2009-01-01

    Blood lipids are important cardiovascular disease (CVD) risk factors with both genetic and environmental determinants. The Whitehall II study (n = 5592) was genotyped with the gene-centric HumanCVD BeadChip (Illumina). We identified 195 SNPs in 16 genes/regions associated with 3 major lipid fractions and 2 apolipoprotein components at p < 10−5, with the associations being broadly concordant with prior genome-wide analysis. SNPs associated with LDL cholesterol and apolipoprotein B were located in LDLR, PCSK9, APOB, CELSR2, HMGCR, CETP, the TOMM40-APOE-C1-C2-C4 cluster, and the APOA5-A4-C3-A1 cluster; SNPs associated with HDL cholesterol and apolipoprotein AI were in CETP, LPL, LIPC, APOA5-A4-C3-A1, and ABCA1; and SNPs associated with triglycerides in GCKR, BAZ1B, MLXIPL, LPL, and APOA5-A4-C3-A1. For 48 SNPs in previously unreported loci that were significant at p < 10−4 in Whitehall II, in silico analysis including the British Women's Heart and Health Study, BRIGHT, ASCOT, and NORDIL studies (total n > 12,500) revealed previously unreported associations of SH2B3 (p < 2.2 × 10−6), BMPR2 (p < 2.3 × 10−7), BCL3/PVRL2 (flanking APOE; p < 4.4 × 10−8), and SMARCA4 (flanking LDLR; p < 2.5 × 10−7) with LDL cholesterol. Common alleles in these genes explained 6.1%–14.7% of the variance in the five lipid-related traits, and individuals at opposite tails of the additive allele score exhibited substantial differences in trait levels (e.g., >1 mmol/L in LDL cholesterol [∼1 SD of the trait distribution]). These data suggest that multiple common alleles of small effect can make important contributions to individual differences in blood lipids potentially relevant to the assessment of CVD risk. These genes provide further insights into lipid metabolism and the likely effects of modifying the encoded targets therapeutically. PMID:19913121

  11. Physical Activity Level Improves the Predictive Accuracy of Cardiovascular Disease Risk Score: The ATTICA Study (2002–2012)

    PubMed Central

    Georgousopoulou, Ekavi N.; Panagiotakos, Demosthenes B.; Bougatsas, Dimitrios; Chatzigeorgiou, Michael; Kavouras, Stavros A.; Chrysohoou, Christina; Skoumas, Ioannis; Tousoulis, Dimitrios; Stefanadis, Christodoulos; Pitsavos, Christos

    2016-01-01

    Background: Although physical activity (PA) has long been associated with cardiovascular disease (CVD), assessment of PA status has never been used as a part of CVD risk prediction tools. The aim of the present work was to examine whether the inclusion of PA status in a CVD risk model improves its predictive accuracy. Methods: Data from the 10-year follow-up (2002–2012) of the n = 2020 participants (aged 18–89 years) of the ATTICA prospective study were used to test the research hypothesis. The HellenicSCORE (that incorporates age, sex, smoking, total cholesterol, and systolic blood pressure levels) was calculated to estimate the baseline 10-year CVD risk; assessment of PA status was based on the International Physical Activity Questionnaire. The estimated CVD risk was tested against the observed 10-year incidence (i.e., development of acute coronary syndromes, stroke, or other CVD according to the World Health Organization [WHO]-International Classification of Diseases [ICD]-10 criteria). Changes in the predictive ability of the nested CVD risk model that contained the HellenicSCORE plus PA assessment were evaluated using Harrell's C and net reclassification index. Results: Both HellenicSCORE and PA status were predictors of future CVD events (P < 0.05). However, the estimating classification bias of the model that included only the HellenicSCORE was significantly reduced when PA assessment was included (Harrel's C = 0.012, P = 0.032); this reduction remained significant even when adjusted for diabetes mellitus and dietary habits (P < 0.05). Conclusions: CVD risk scores seem to be more accurate by incorporating individuals’ PA status; thus, may be more effective tools in primary prevention by efficiently allocating CVD candidates. PMID:27076890

  12. Determination of the absolute contours of optical flats

    NASA Technical Reports Server (NTRS)

    Primak, W.

    1969-01-01

    Emersons procedure is used to determine true absolute contours of optical flats. Absolute contours of standard flats are determined and a comparison is then made between standard and unknown flats. Contour differences are determined by deviation of Fizeau fringe.

  13. CVD diamond for optics applications in high heat flux environments

    SciTech Connect

    Klein, C.A.

    1996-12-31

    Diamond has a cubic lattice structure and a very wide bandgap, which suggests that this material should exhibit excellent optical properties at wavelengths ranging from the far infrared to the near ultraviolet. Since diamond also exhibits unusually favorable properties in terms of mechanical strength, chemical stability, and thermal conductivity, there is considerable interest in using diamond for optics applications that involve adverse environmental conditions. The purpose of this paper is to provide an updated assessment of some of the issues that arise in connection with the use of chemically vapor-deposited (CVD) diamond for applications such as missile system windows or domes, and for designing components that must function in the high photon flux of high-power lasers. Specifically, since the flight velocities of future air-intercept missiles are projected to far exceed those of contemporary systems, this raises the issue of how to assess the capability of window/dome material candidates in an aero-thermal shock environment. In this context, it can be demonstrated that, compared to other candidate materials, diamond windows promise to deliver superior performances and should be able to meet any foreseeable requirement. Operation at high speeds, however, imposes limits on the tolerable window emittance to prevent blinding the seeker, and this issue leads to the conclusion that diamond is intrinsically unsuitable for operation in the 3- to 5-{micro}m spectral band. Concerning high-energy lasers, note that operational systems always include an optical train consisting of mirrors and windows, which must be capable of transporting and directing the beam without seriously degrading the nominal performance of the laser. In this regard, mirror-faceplate material candidates can be ranked on the basis of appropriate figures of merit, which demonstrate that diamond is of particular promise for high-heat-load applications that require efficient cooling.

  14. Challenges and Opportunities for the implementation of interventions to prevent and control CVD in low resource settings in Argentina

    PubMed Central

    Rubinstein, Adolfo; Irazola, Vilma E.; Poggio, Rosana; Gulayin, Pablo; Nejamis, Analía; Beratarrechea, Andrea

    2015-01-01

    In Argentina, Cardiovascular diseases are estimated to cause about 100,000 deaths and more than 250,000 coronary heart disease and stroke events annually, at a cost of more than one billion international dollars. Despite progress in the implementation of several programs to combat non-communicable diseases in Argentina over the last years, most health resources are still dedicated to infectious disease and maternal and child health. The Institute for Clinical Effectiveness and Health Policy, an independent academic institution affiliated to the University of Buenos Aires medical school, runs CESCAS (South American Centre of Excellence in Cardiovascular Health), a center devoted to epidemiological, implementation and policy research. At CESCAS there are three ongoing randomized clinical trials focused on implementation science: 1) A Mobile health intervention to prevent progression of pre-hypertension in poor urban settings in Argentina, Guatemala and Peru; 2) A Comprehensive Approach for Hypertension Prevention and Control in low-resource settings in Argentina; and 3) An Educational Approach to Improve Physician Effectiveness in the Detection, Treatment and Control for patients with Hypercholesterolemia and high Cardiovascular Disease (CVD) risk in low-resource settings in Argentina. All these studies involve the design and implementation of complex interventions to change behaviors of providers and patients. The rationale of each of the three studies, the design of the interventions and the evaluation of processes and outcomes are described in this article together with the barriers and enabling factors associated with implementation research studies. There is a strong need in Argentina and the region at large to build the health research capacity and infrastructure necessary to undertake implementation studies to translate evidence from research findings into improvements in health policy and practice to address CVD and their risk factors. PMID:25754563

  15. Long-term effects of a lifestyle intervention on weight and cardiovascular risk factors in individuals with type 2 diabetes mellitus: Four-year results of the Look AHEAD trial

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lifestyle interventions produce short-term improvements in glycemia and cardiovascular disease (CVD) risk factors in individuals with type 2 diabetes mellitus, but no long-term data are available. We examined the effects of lifestyle intervention on changes in weight, fitness, and CVD risk factors d...

  16. Predicted 10-year risk of cardiovascular disease among Canadian adults using modified Framingham Risk Score in association with dietary intake.

    PubMed

    Setayeshgar, Solmaz; Whiting, Susan J; Pahwa, Punam; Vatanparast, Hassanali

    2015-10-01

    Initial risk assessment to estimate 10-year risk of cardiovascular disease (CVD) is completed by Framingham Risk Score (FRS). In 2012 2 modifications were added to FRS by the Canadian Cardiovascular Society: FRS is doubled in subjects aged 30-59 years who have CVD present in a first-degree relative before 55 years of age for men and 65 years of age for women; and cardiovascular age is calculated for each individual. Our aim was to implement these modifications and evaluate differences compared with traditional FRS. Further, we evaluated the association between dietary intake and 10-year risk. The Canadian Health Measures Survey data cycle 1 was used among participants aged 30-74 years (n = 2730). Descriptive and logistic regression analyses were conducted using STATA SE 11. Using modified FRS for predicting 10-year risk of CVD significantly increased the estimated risk compared with the traditional approach, 8.66% ± 0.35% versus 6.06% ± 0.18%, respectively. Greater impact was observed with the "cardiovascular age" modification in men versus women. The distribution of Canadians in low- (<10%) and high-risk (≥20%) categories of CVD show a significant difference between modified and traditional FRS: 67.4% versus 79.6% (low risk) and 13.7% versus 4.5% (high risk), respectively. The odds of having risk ≥10% was significantly greater in low-educated, abdominally obese individuals or those with lower consumption of breakfast cereal and fruit and vegetable and greater potato and potato products consumption. In conclusion, the traditional FRS method significantly underestimates CVD risk in Canadians; thus, applying modified FRS is beneficial for screening. Additionally, fibre consumption from fruit and vegetable or breakfast cereals might be beneficial in reducing CVD risks. PMID:26417841

  17. Standardization of the cumulative absolute velocity

    SciTech Connect

    O'Hara, T.F.; Jacobson, J.P. )

    1991-12-01

    EPRI NP-5930, A Criterion for Determining Exceedance of the Operating Basis Earthquake,'' was published in July 1988. As defined in that report, the Operating Basis Earthquake (OBE) is exceeded when both a response spectrum parameter and a second damage parameter, referred to as the Cumulative Absolute Velocity (CAV), are exceeded. In the review process of the above report, it was noted that the calculation of CAV could be confounded by time history records of long duration containing low (nondamaging) acceleration. Therefore, it is necessary to standardize the method of calculating CAV to account for record length. This standardized methodology allows consistent comparisons between future CAV calculations and the adjusted CAV threshold value based upon applying the standardized methodology to the data set presented in EPRI NP-5930. The recommended method to standardize the CAV calculation is to window its calculation on a second-by-second basis for a given time history. If the absolute acceleration exceeds 0.025g at any time during each one second interval, the earthquake records used in EPRI NP-5930 have been reanalyzed and the adjusted threshold of damage for CAV was found to be 0.16g-set.

  18. Absolute rates of hole transfer in DNA.

    PubMed

    Senthilkumar, Kittusamy; Grozema, Ferdinand C; Guerra, Célia Fonseca; Bickelhaupt, F Matthias; Lewis, Frederick D; Berlin, Yuri A; Ratner, Mark A; Siebbeles, Laurens D A

    2005-10-26

    Absolute rates of hole transfer between guanine nucleobases separated by one or two A:T base pairs in stilbenedicarboxamide-linked DNA hairpins were obtained by improved kinetic analysis of experimental data. The charge-transfer rates in four different DNA sequences were calculated using a density-functional-based tight-binding model and a semiclassical superexchange model. Site energies and charge-transfer integrals were calculated directly as the diagonal and off-diagonal matrix elements of the Kohn-Sham Hamiltonian, respectively, for all possible combinations of nucleobases. Taking into account the Coulomb interaction between the negative charge on the stilbenedicarboxamide linker and the hole on the DNA strand as well as effects of base pair twisting, the relative order of the experimental rates for hole transfer in different hairpins could be reproduced by tight-binding calculations. To reproduce quantitatively the absolute values of the measured rate constants, the effect of the reorganization energy was taken into account within the semiclassical superexchange model for charge transfer. The experimental rates could be reproduced with reorganization energies near 1 eV. The quantum chemical data obtained were used to discuss charge carrier mobility and hole-transport equilibria in DNA. PMID:16231945

  19. Transient absolute robustness in stochastic biochemical networks.

    PubMed

    Enciso, German A

    2016-08-01

    Absolute robustness allows biochemical networks to sustain a consistent steady-state output in the face of protein concentration variability from cell to cell. This property is structural and can be determined from the topology of the network alone regardless of rate parameters. An important question regarding these systems is the effect of discrete biochemical noise in the dynamical behaviour. In this paper, a variable freezing technique is developed to show that under mild hypotheses the corresponding stochastic system has a transiently robust behaviour. Specifically, after finite time the distribution of the output approximates a Poisson distribution, centred around the deterministic mean. The approximation becomes increasingly accurate, and it holds for increasingly long finite times, as the total protein concentrations grow to infinity. In particular, the stochastic system retains a transient, absolutely robust behaviour corresponding to the deterministic case. This result contrasts with the long-term dynamics of the stochastic system, which eventually must undergo an extinction event that eliminates robustness and is completely different from the deterministic dynamics. The transiently robust behaviour may be sufficient to carry out many forms of robust signal transduction and cellular decision-making in cellular organisms. PMID:27581485

  20. Absolute Electron Extraction Efficiency of Liquid Xenon

    NASA Astrophysics Data System (ADS)

    Kamdin, Katayun; Mizrachi, Eli; Morad, James; Sorensen, Peter

    2016-03-01

    Dual phase liquid/gas xenon time projection chambers (TPCs) currently set the world's most sensitive limits on weakly interacting massive particles (WIMPs), a favored dark matter candidate. These detectors rely on extracting electrons from liquid xenon into gaseous xenon, where they produce proportional scintillation. The proportional scintillation from the extracted electrons serves to internally amplify the WIMP signal; even a single extracted electron is detectable. Credible dark matter searches can proceed with electron extraction efficiency (EEE) lower than 100%. However, electrons systematically left at the liquid/gas boundary are a concern. Possible effects include spontaneous single or multi-electron proportional scintillation signals in the gas, or charging of the liquid/gas interface or detector materials. Understanding EEE is consequently a serious concern for this class of rare event search detectors. Previous EEE measurements have mostly been relative, not absolute, assuming efficiency plateaus at 100%. I will present an absolute EEE measurement with a small liquid/gas xenon TPC test bed located at Lawrence Berkeley National Laboratory.

  1. Sentinel-2/MSI absolute calibration: first results

    NASA Astrophysics Data System (ADS)

    Lonjou, V.; Lachérade, S.; Fougnie, B.; Gamet, P.; Marcq, S.; Raynaud, J.-L.; Tremas, T.

    2015-10-01

    Sentinel-2 is an optical imaging mission devoted to the operational monitoring of land and coastal areas. It is developed in partnership between the European Commission and the European Space Agency. The Sentinel-2 mission is based on a satellites constellation deployed in polar sun-synchronous orbit. It will offer a unique combination of global coverage with a wide field of view (290km), a high revisit (5 days with two satellites), a high resolution (10m, 20m and 60m) and multi-spectral imagery (13 spectral bands in visible and shortwave infra-red domains). CNES is involved in the instrument commissioning in collaboration with ESA. This paper reviews all the techniques that will be used to insure an absolute calibration of the 13 spectral bands better than 5% (target 3%), and will present the first results if available. First, the nominal calibration technique, based on an on-board sun diffuser, is detailed. Then, we show how vicarious calibration methods based on acquisitions over natural targets (oceans, deserts, and Antarctica during winter) will be used to check and improve the accuracy of the absolute calibration coefficients. Finally, the verification scheme, exploiting photometer in-situ measurements over Lacrau plain, is described. A synthesis, including spectral coherence, inter-methods agreement and temporal evolution, will conclude the paper.

  2. Absolute Spectrophotometry of 237 Open Cluster Stars

    NASA Astrophysics Data System (ADS)

    Clampitt, L.; Burstein, D.

    1994-12-01

    We present absolute spectrophotometry of 237 stars in 7 nearby open clusters: Hyades, Pleiades, Alpha Persei, Praesepe, Coma Berenices, IC 4665, and M 39. The observations were taken using the Wampler single-channel scanner (Wampler 1966) on the Crossley 0.9m telescope at Lick Observatory from July 1973 through December 1974. 21 bandpasses spanning the spectral range 3500 Angstroms to 7780 Angstroms were observed for each star, with bandwiths ranging from 32Angstroms to 64 Angstroms. Data are standardized to the Hayes--Latham (1975) system. Our measurements are compared to filter colors on the Johnson BV, Stromgren ubvy, and Geneva U V B_1 B_2 V_1 G systems, as well as to spectrophotometry of a few stars published by Gunn, Stryker & Tinsley and in the Spectrophotometric Standards Catalog (Adelman; as distributed by the NSSDC). Both internal and external comparisons to the filter systems indicate a formal statistical accuracy per bandpass of 0.01 to 0.02 mag, with apparent larger ( ~ 0.03 mag) differences in absolute calibration between this data set and existing spectrophotometry. These data will comprise part of the spectrophotometry that will be used to calibrate the Beijing-Arizona-Taipei-Connecticut Color Survey of the Sky (see separate paper by Burstein et al. at this meeting).

  3. A Conceptual Approach to Absolute Value Equations and Inequalities

    ERIC Educational Resources Information Center

    Ellis, Mark W.; Bryson, Janet L.

    2011-01-01

    The absolute value learning objective in high school mathematics requires students to solve far more complex absolute value equations and inequalities. When absolute value problems become more complex, students often do not have sufficient conceptual understanding to make any sense of what is happening mathematically. The authors suggest that the…

  4. Using, Seeing, Feeling, and Doing Absolute Value for Deeper Understanding

    ERIC Educational Resources Information Center

    Ponce, Gregorio A.

    2008-01-01

    Using sticky notes and number lines, a hands-on activity is shared that anchors initial student thinking about absolute value. The initial point of reference should help students successfully evaluate numeric problems involving absolute value. They should also be able to solve absolute value equations and inequalities that are typically found in…

  5. 20 CFR 404.1205 - Absolute coverage groups.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Absolute coverage groups. 404.1205 Section... INSURANCE (1950- ) Coverage of Employees of State and Local Governments What Groups of Employees May Be Covered § 404.1205 Absolute coverage groups. (a) General. An absolute coverage group is a...

  6. Cardiovascular diseases and risk factors among Chinese immigrants.

    PubMed

    Gong, Zhizhong; Zhao, Dong

    2016-04-01

    The aim of this study is to identify the prevalence of cardiovascular disease (CVD) and major CVD risk factors, including diabetes, hypertension, dyslipidemia, obesity and smoking among Chinese immigrants by a systematic review of studies from various countries. PubMed and the China National Knowledge Infrastructure databases were searched for studies of the prevalence of major CVDs and risk factors, and of CVD mortality among Chinese immigrants. The search identified 386 papers, 16 of which met the inclusion criteria for this review. In mainland China, there is a pattern of high stroke prevalence but low coronary heart disease (CHD) prevalence. Among Chinese immigrants, there is a much lower prevalence and mortality of stroke, but a higher prevalence and mortality of CHD, even though these are lower than the rates in immigrants of other ethnicities in the host country. The prevalence of CVD risk factors is also markedly different in immigrants. Compared with mainland Chinese, Chinese immigrants have a higher prevalence of diabetes and hypertension, higher serum cholesterol, poorer dietary patterns, and higher prevalence of obesity and smoking. Thus, the epidemiological pattern of CVD among Chinese immigrants changes compared with resident mainland Chinese. The less healthy environmental factor after immigration may be a major trigger in the adverse CVD status of Chinese immigrants. It is important for policy-makers to pay more attention to specific minority immigrant groups, and to implement more effective preventive measures to improve the health of immigrant populations. PMID:26350421

  7. Low serum testosterone increases mortality risk among male dialysis patients.

    PubMed

    Carrero, Juan Jesús; Qureshi, Abdul Rashid; Parini, Paolo; Arver, Stefan; Lindholm, Bengt; Bárány, Peter; Heimbürger, Olof; Stenvinkel, Peter

    2009-03-01

    Men treated with hemodialysis (HD) have a very poor prognosis and an elevated risk of premature cardiovascular disease (CVD). In the general population, associations between low testosterone concentrations and cardiovascular risk have been suggested. We performed a prospective observational study involving a well characterized cohort of 126 men treated with HD to examine the relationship between testosterone concentration and subsequent mortality during a mean follow-up period of 41 mo. Independent of age, serum creatinine, and sexual hormone binding globulin (SHBG), testosterone levels inversely and strongly associated with the inflammatory markers IL-6 and CRP. Patients with a clinical history of CVD had significantly lower testosterone levels. During follow up, 65 deaths occurred, 58% of which were a result of CVD. Men with testosterone values in the lowest tertile had increased all-cause and CVD mortality (crude hazard ratios [HRs] 2.03 [95% CI 1.24 to 3.31] and 3.19 [1.49 to 6.83], respectively), which persisted after adjustment for age, SHBG, previous CVD, diabetes, ACEi/ARB treatment, albumin, and inflammatory markers, but was lost after adjustment for creatinine. In summary, among men treated with HD, testosterone concentrations inversely correlate with all-cause and CVD-related mortality, as well as with markers of inflammation. Hypogonadism may be an additional treatable risk factor for patients with chronic kidney disease. PMID:19144759

  8. Novel Risk Factors of Cardiovascular Disease and Their Associations Between Obesity, Physical Activity And Physical Fitness

    PubMed Central

    Buchan, Duncan S.; Thomas, Non E.; Baker, Julien S.

    2012-01-01

    The prevalence of cardiovascular disease (CVD) is increasing around the globe and is the leading cause of death around the world. Though once thought of as an adult problem, it is now recognised that the early manifestations of disease may occur during childhood. Numerous risk factors have been linked to CVD with much of the research focusing on understanding the prevalence and relationship of traditional risk factors such as dyslipidemia, smoking, diabetes mellitus, hypertension, obesity, psychosocial stress, poor diet, physical inactivity and alcohol consumption to the early etiology of disease. While this line of investigation has greatly enhanced our understanding of the relationship between these risk factors and disease, they do not fully explain all cardiovascular events. To enhance our understanding and help with the management of CVD, investigations that involve the measurement of traditional as well as novel risk factors may be necessary. Public health strategies that aim to reduce the prevalence of obesity and overweight encourage youth to increase their physical activity levels as a means of protecting against poor cardiometabolic profiles. Interventions that increase physical activity levels and improve cardiorespiratory fitness cause a reduction in certain CVD risk factors but the lack of agreement between findings makes it impossible to give precise recommendations that will ensure CVD risk reduction. Yet it is important that research continues in order to establish the most appropriate means of improving the health and well-being of those at most risk of future CVD. PMID:25170447

  9. Surface morphology and resistivity of aluminum oxide films prepared by plasma CVD combined with ion beam irradiation

    NASA Astrophysics Data System (ADS)

    Nakai, H.; Shinohara, J.; Sassa, T.; Ikegami, Y.

    1997-01-01

    Plasma CVD combined with simultaneous ion beams has been developed in order to prepare ceramic insulating films which have strong force of adhesion and higher electric resistivity at high temperatures. Aluminum oxide (Al 2O 3) films were deposited on nickel based superalloy (Inconel 718) by thermal CVD, plasma CVD and ion beam assisted plasma CVD at the several substrate temperatures. The surface morphology of these films was analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). It was confirmed that, by ion beam irradiation, the extent of crystallization was enhanced at lower substrate temperature and grain size became smaller. The electric resistivity was measured in the temperature range of RT to 800°C. The film, deposited by ion beam assisted plasma CVD at 800°C, had higher electric resistivity than the films by conventional CVD.

  10. CVD mullite coatings in high-temperature, high-pressure air-H{sub 2}O[Chemical Vapor Deposition

    SciTech Connect

    Haynes, J.A.; Lance, M.J.; Cooley, K.M.; Ferber, M.K.; Lowden, R.A.; Stinton, D.P.

    2000-03-01

    Crystalline mullite was deposited by chemical vapor deposition (CVD) onto SiC/SiC composites overlaid with CVD SiC. Specimens were exposed to isothermal oxidation tests in high-pressure air +H{sub 2}O at 1,200 C. Unprotected CVD SiC formed silica scales with a dense amorphous inner layer and a thick, porous, outer layer of cristobalite. Thin coatings ({approximately}2{mu}m) of dense CVD mullite effectively suppressed the rapid oxidation of CVD SiC. No microstructural evidence of mullite volatility was observed under these temperature, pressure, and low-flow-rate conditions. Results of this preliminary study indicate that dense, crystalline, high-purity CVD mullite is stable and protective in low-velocity, high-pressure, moisture-containing environments.

  11. Use of Absolute and Comparative Performance Feedback in Absolute and Comparative Judgments and Decisions

    ERIC Educational Resources Information Center

    Moore, Don A.; Klein, William M. P.

    2008-01-01

    Which matters more--beliefs about absolute ability or ability relative to others? This study set out to compare the effects of such beliefs on satisfaction with performance, self-evaluations, and bets on future performance. In Experiment 1, undergraduate participants were told they had answered 20% correct, 80% correct, or were not given their…

  12. Magneto Transport of CVD Carbon in Artificial Opals

    NASA Astrophysics Data System (ADS)

    Wang, Lei; Yin, Ming; Arammash, Fauzi; Datta, Timir

    2014-03-01

    Magneto-transport of carbon inverse opal structures were investigated in the 2.5 to 300 K temperatures and magnetic fields in the 0-10T regime. Qualitatively, our observations lie between those reported by previous researchers. Over this temperature range, transport (in zero magnetic field) is non-metallic; the resistance decreased with rising temperature however the temperature dependent behavior is not activated, as observed with variable range hopping. In three-dimensions, such behavior can also be the result of weak localization and electron-electron interactions; in particular the change in conductivity is a polynomial in fractional powers of absolute temperature. At sub-helium temperature regimes the relative magneto resistance is measured to be ~ 0.1 percent per Tesla. Results of data analysis for several different scenarios will be reported. DOD award #60177-RT-H from the ARO.

  13. Effects of nutrition and exercise health behaviors on predicted risk of cardiovascular disease among workers with different body mass index levels.

    PubMed

    Huang, Jui-Hua; Huang, Shu-Ling; Li, Ren-Hau; Wang, Ling-Hui; Chen, Yu-Ling; Tang, Feng-Cheng

    2014-05-01

    Workplace health promotion programs should be tailored according to individual needs and efficient intervention. This study aimed to determine the effects of nutrition and exercise health behaviors on predicted risk for cardiovascular disease (CVD) when body mass index (BMI) is considered. In total, 3350 Taiwanese workers were included in this cross-sectional study. A self-reported questionnaire was used to measure their nutrition and exercise behaviors. Data on anthropometric values, biochemical blood determinations, and predicted CVD risk (using the Framingham risk score) were collected. In multiple regression analyses, the nutrition behavior score was independently and negatively associated with CVD risk. Exercise was not significantly associated with the risk. However, the interactive effect of exercise and BMI on CVD risk was evident. When stratified by BMI levels, associations between exercise and CVD risk were statistically significant for ideal weight and overweight subgroups. In conclusion, nutrition behavior plays an important role in predicting the CVD risk. Exercise behavior is also a significant predictor for ideal weight and overweight workers. Notably, for underweight or obese workers, maintaining health-promoting exercise seems insufficient to prevent the CVD. In order to improve workers' cardiovascular health, more specific health-promoting strategies should be developed to suit the different BMI levels. PMID:24785541

  14. Effects of Nutrition and Exercise Health Behaviors on Predicted Risk of Cardiovascular Disease among Workers with Different Body Mass Index Levels

    PubMed Central

    Huang, Jui-Hua; Huang, Shu-Ling; Li, Ren-Hau; Wang, Ling-Hui; Chen, Yu-Ling; Tang, Feng-Cheng

    2014-01-01

    Workplace health promotion programs should be tailored according to individual needs and efficient intervention. This study aimed to determine the effects of nutrition and exercise health behaviors on predicted risk for cardiovascular disease (CVD) when body mass index (BMI) is considered. In total, 3350 Taiwanese workers were included in this cross-sectional study. A self-reported questionnaire was used to measure their nutrition and exercise behaviors. Data on anthropometric values, biochemical blood determinations, and predicted CVD risk (using the Framingham risk score) were collected. In multiple regression analyses, the nutrition behavior score was independently and negatively associated with CVD risk. Exercise was not significantly associated with the risk. However, the interactive effect of exercise and BMI on CVD risk was evident. When stratified by BMI levels, associations between exercise and CVD risk were statistically significant for ideal weight and overweight subgroups. In conclusion, nutrition behavior plays an important role in predicting the CVD risk. Exercise behavior is also a significant predictor for ideal weight and overweight workers. Notably, for underweight or obese workers, maintaining health-promoting exercise seems insufficient to prevent the CVD. In order to improve workers’ cardiovascular health, more specific health-promoting strategies should be developed to suit the different BMI levels. PMID:24785541

  15. Absolute calibration of ultraviolet filter photometry

    NASA Technical Reports Server (NTRS)

    Bless, R. C.; Fairchild, T.; Code, A. D.

    1972-01-01

    The essential features of the calibration procedure can be divided into three parts. First, the shape of the bandpass of each photometer was determined by measuring the transmissions of the individual optical components and also by measuring the response of the photometer as a whole. Secondly, each photometer was placed in the essentially-collimated synchrotron radiation bundle maintained at a constant intensity level, and the output signal was determined from about 100 points on the objective. Finally, two or three points on the objective were illuminated by synchrotron radiation at several different intensity levels covering the dynamic range of the photometers. The output signals were placed on an absolute basis by the electron counting technique described earlier.

  16. MAGSAT: Vector magnetometer absolute sensor alignment determination

    NASA Technical Reports Server (NTRS)

    Acuna, M. H.

    1981-01-01

    A procedure is described for accurately determining the absolute alignment of the magnetic axes of a triaxial magnetometer sensor with respect to an external, fixed, reference coordinate system. The method does not require that the magnetic field vector orientation, as generated by a triaxial calibration coil system, be known to better than a few degrees from its true position, and minimizes the number of positions through which a sensor assembly must be rotated to obtain a solution. Computer simulations show that accuracies of better than 0.4 seconds of arc can be achieved under typical test conditions associated with existing magnetic test facilities. The basic approach is similar in nature to that presented by McPherron and Snare (1978) except that only three sensor positions are required and the system of equations to be solved is considerably simplified. Applications of the method to the case of the MAGSAT Vector Magnetometer are presented and the problems encountered discussed.

  17. Absolute geostrophic currents in global tropical oceans

    NASA Astrophysics Data System (ADS)

    Yang, Lina; Yuan, Dongliang

    2016-03-01

    A set of absolute geostrophic current (AGC) data for the period January 2004 to December 2012 are calculated using the P-vector method based on monthly gridded Argo profiles in the world tropical oceans. The AGCs agree well with altimeter geostrophic currents, Ocean Surface Current Analysis-Real time currents, and moored current-meter measurements at 10-m depth, based on which the classical Sverdrup circulation theory is evaluated. Calculations have shown that errors of wind stress calculation, AGC transport, and depth ranges of vertical integration cannot explain non-Sverdrup transport, which is mainly in the subtropical western ocean basins and equatorial currents near the Equator in each ocean basin (except the North Indian Ocean, where the circulation is dominated by monsoons). The identified non-Sverdrup transport is thereby robust and attributed to the joint effect of baroclinicity and relief of the bottom (JEBAR) and mesoscale eddy nonlinearity.

  18. Absolute Measurement of Electron Cloud Density

    SciTech Connect

    Covo, M K; Molvik, A W; Cohen, R H; Friedman, A; Seidl, P A; Logan, G; Bieniosek, F; Baca, D; Vay, J; Orlando, E; Vujic, J L

    2007-06-21

    Beam interaction with background gas and walls produces ubiquitous clouds of stray electrons that frequently limit the performance of particle accelerator and storage rings. Counterintuitively we obtained the electron cloud accumulation by measuring the expelled ions that are originated from the beam-background gas interaction, rather than by measuring electrons that reach the walls. The kinetic ion energy measured with a retarding field analyzer (RFA) maps the depressed beam space-charge potential and provides the dynamic electron cloud density. Clearing electrode current measurements give the static electron cloud background that complements and corroborates with the RFA measurements, providing an absolute measurement of electron cloud density during a 5 {micro}s duration beam pulse in a drift region of the magnetic transport section of the High-Current Experiment (HCX) at LBNL.

  19. Absolute instability of a viscous hollow jet

    NASA Astrophysics Data System (ADS)

    Gañán-Calvo, Alfonso M.

    2007-02-01

    An investigation of the spatiotemporal stability of hollow jets in unbounded coflowing liquids, using a general dispersion relation previously derived, shows them to be absolutely unstable for all physical values of the Reynolds and Weber numbers. The roots of the symmetry breakdown with respect to the liquid jet case, and the validity of asymptotic models are here studied in detail. Asymptotic analyses for low and high Reynolds numbers are provided, showing that old and well-established limiting dispersion relations [J. W. S. Rayleigh, The Theory of Sound (Dover, New York, 1945); S. Chandrasekhar, Hydrodynamic and Hydromagnetic Stability (Dover, New York, 1961)] should be used with caution. In the creeping flow limit, the analysis shows that, if the hollow jet is filled with any finite density and viscosity fluid, a steady jet could be made arbitrarily small (compatible with the continuum hypothesis) if the coflowing liquid moves faster than a critical velocity.

  20. Stitching interferometry: recent results and absolute calibration

    NASA Astrophysics Data System (ADS)

    Bray, Michael

    2004-02-01

    Stitching Interferometry is a method of analysing large optical components using a standard "small" interferometer. This result is obtained by taking multiple overlapping images of the large component, and numerically "stitching" these sub-apertures together. We have already reported the industrial use our Stitching Interferometry systems (Previous SPIE symposia), but experimental results had been lacking because this technique is still new, and users needed to get accustomed to it before producing reliable measurements. We now have more results. We will report user comments and show new, unpublished results. We will discuss sources of error, and show how some of these can be reduced to arbitrarily small values. These will be discussed in some detail. We conclude with a few graphical examples of absolute measurements performed by us.

  1. Swarm's Absolute Scalar Magnetometer metrological performances

    NASA Astrophysics Data System (ADS)

    Leger, J.; Fratter, I.; Bertrand, F.; Jager, T.; Morales, S.

    2012-12-01

    The Absolute Scalar Magnetometer (ASM) has been developed for the ESA Earth Observation Swarm mission, planned for launch in November 2012. As its Overhauser magnetometers forerunners flown on Oersted and Champ satellites, it will deliver high resolution scalar measurements for the in-flight calibration of the Vector Field Magnetometer manufactured by the Danish Technical University. Latest results of the ground tests carried out to fully characterize all parameters that may affect its accuracy, both at instrument and satellite level, will be presented. In addition to its baseline function, the ASM can be operated either at a much higher sampling rate (burst mode at 250 Hz) or in a dual mode where it also delivers vector field measurements as a by-product. The calibration procedure and the relevant vector performances will be discussed.

  2. Absolute nonlocality via distributed computing without communication

    NASA Astrophysics Data System (ADS)

    Czekaj, Ł.; Pawłowski, M.; Vértesi, T.; Grudka, A.; Horodecki, M.; Horodecki, R.

    2015-09-01

    Understanding the role that quantum entanglement plays as a resource in various information processing tasks is one of the crucial goals of quantum information theory. Here we propose an alternative perspective for studying quantum entanglement: distributed computation of functions without communication between nodes. To formalize this approach, we propose identity games. Surprisingly, despite no signaling, we obtain that nonlocal quantum strategies beat classical ones in terms of winning probability for identity games originating from certain bipartite and multipartite functions. Moreover we show that, for a majority of functions, access to general nonsignaling resources boosts success probability two times in comparison to classical ones for a number of large enough outputs. Because there are no constraints on the inputs and no processing of the outputs in the identity games, they detect very strong types of correlations: absolute nonlocality.

  3. Social Support and Cardiovascular Risk Factors among Black Adults

    PubMed Central

    Hernandez, Daphne C.; Reitzel, Lorraine R.; Wetter, David W.; McNeill, Lorna H.

    2016-01-01

    Objective Cardiovascular disease (CVD) risk factors are prevalent among Black adults. Studies have demonstrated that functional social support buffers CVD risk. The objective of this study is to assess whether specific types of functional social support or their cumulative total buffers CVD risk factors among a convenience sample of Black adults, and whether these associations differ by gender or partner status. Design Cross-sectional study using self-reported survey data. Setting Large church in Houston, TX. Participants A total of 1,381 Black adults reported their perceived social support using appraisal, belonging, and tangible subscales of the Interpersonal Support Evaluation List-12. A cumulative score was created based on the three subscales. Participants also reported on a number of socio-demographic characteristics. Main Outcome Measures Three self-reported CVD risk factors: diabetes, high blood pressure, and high cholesterol (yes versus no). Results A series of multivariate logistic regressions controlling for socio-demographic characteristics were used to calculate adjusted odds ratios (aOR) and 95% confidence intervals (CI) for CVD risk factors. Cumulative social support, rather than any specific type of social support, was significantly related to diabetes and high blood pressure. Higher cumulative social support was associated with lower odds of experiencing diabetes (aOR = 0.97, 95% CI = 0.94, 0.99) and high blood pressure (aOR = 0.98, 95% CI = 0.95, 0.99). Neither gender nor partner status moderated associations. Conclusion In a high risk population for CVD, increasing all types of social support - appraisal, belonging, and tangible - might be useful in preventing or delaying the onset of CVD. PMID:25417427

  4. Metal oxide growth, spin precession measurements and Raman spectroscopy of CVD graphene

    NASA Astrophysics Data System (ADS)

    Matsubayashi, Akitomo

    The focus of this dissertation is to explore the possibility of wafer scale graphene-based spintronics. Graphene is a single atomic layer of sp 2 bonded carbon atoms that has attracted much attention as a new type of electronic material due to its high carrier mobilities, superior mechanical properties and extremely high thermal conductivity. In addition, it has become an attractive material for use in spintronic devices owing to its long electron spin relaxation time at room temperature. This arises in part from its low spin-orbit coupling and negligible nuclear hyperfine interaction. In order to realize wafer scale graphene spintronics, utilization of CVD grown graphene is crytical due to its scalability. In this thesis, a unique fabrication method of the metal oxide layers on CVD graphene is presented. This is motivated by theoretical work showing that an ultra thin metal oxide film used as a tunnel barrier improves the spin injection efficiency. Introducing a titanium seed layer prior to the aluminum oxide growth showed improved surface and film uniformity and resulted in a completely oxidized film. Utilizing this unique metal oxide film growth process, lateral spin valve devices using CVD graphene as a channel are successfully fabricated. Hanle spin precession measurements are demonstrated on these CVD graphene spin devices. A non-local Hanle voltage model based upon the diffusive spin transport in a solid is utilized to find the spin diffusion length and spin relaxation time of CVD graphene. The measured spin relaxation times in CVD graphene were compatible with the values found in the literature. However, they are an order of magnitude shorter than the theoretical values expected in graphene. To investigate possible origins of this order of magnitude shorter spin relaxation time in graphene, crystal and electrical modifications in CVD graphene are studied throughout the entire device fabrication process. Raman spectroscopy is utilized to track CVD graphene

  5. Overview of Risk-Estimation Tools for Primary Prevention of Cardiovascular Diseases in European Populations.

    PubMed

    Gorenoi, Vitali; Hagen, Anja

    2015-06-01

    To identify persons with a high risk for cardiovascular diseases (CVD) special tools (scores, charts, graphics or computer programs) for CVD-risk assessment based on levels of the certain risk factors have been constructed. The applicability of these instruments depends on the derivation cohorts, considered risk factors and endpoints, applied statistical methods as well as used formats. The review addresses the risk-estimation tools for primary prevention of CVD potentially relevant for European populations. The risk-estimation tools were identified using two previously published systematic reviews as well as conducting a literature search in MEDLINE and a manual search. Only instruments were considered which were derived from cohorts of at least 1,000 participants of one gender without pre-existing CVD, enable risk assessment for a period of at least 5 years, were designed for an age-range of at least 25 years and published after the year 2000. A number of risk-estimation tools for CVD derived from single European, several European and from non-European cohorts were identified. From a clinical perspective, seem to be preferable instruments for risk of CVD contemporary developed for the population of interest, which use easily accessible measures and show a high discriminating ability. Instruments, restricting risk-estimation to certain cardiovascular events, recalibrated high-accuracy tools or tools derived from European populations with similar risk factors distribution and CVD-incidence are the second choice. In younger people, calculating the relative risk or cardiovascular age equivalence measures may be of more benefit. PMID:26851417

  6. Application of CVD diamonds as dosimeters of soft X-ray emission from plasma sources

    NASA Astrophysics Data System (ADS)

    Krása, J.; Juha, L.; Vorlíček, V.; Cejnarová, A.

    2004-05-01

    The thermoluminescent properties of polycrystalline chemical vapour deposition (CVD) diamond, as free-standing CVD cutting tool material, type CVDITE-CDM (De Beers Company), were studied with respect to its use in the dosimetry of soft X-ray emission from laser-produced plasma. The range of linearity for 5.9-keV radiation was measured to be only two orders of magnitude, ranging from a sensitivity threshold of ˜0.01 to ˜2 Gy. In this linearity range, the sensitivity of CVD diamonds is about 65 times lower than the sensitivity of TLD-100 dosimeters. The unpolished (grained) face of CVD diamonds shows ˜1.5-times higher thermoluminescence (TL) response after irradiation than the polished face, in the high-temperature range, but the polished face shows slightly higher TL response in the low-temperature range. A strong TL sensitivity to the blue portion of the visible light spectrum was measured. Simultaneous irradiation of TLD-100 dosimeters and CVD diamonds by soft X-rays emitted from a laser-produced plasma showed that CVDITE-CDM diamonds can be applied as detectors of intense soft X-ray radiation.

  7. 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/). PMID:27164589

  8. Enhanced cold wall CVD reactor growth of horizontally aligned single-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Mu, Wei; Kwak, Eun-Hye; Chen, Bingan; Huang, Shirong; Edwards, Michael; Fu, Yifeng; Jeppson, Kjell; Teo, Kenneth; Jeong, Goo-Hwan; Liu, Johan

    2016-05-01

    HASynthesis of horizontally-aligned single-walled carbon nanotubes (HA-SWCNTs) by chemical vapor deposition (CVD) directly on quartz seems very promising for the fabrication of future nanoelectronic devices. In comparison to hot-wall CVD, synthesis of HA-SWCNTs in a cold-wall CVD chamber not only means shorter heating, cooling and growth periods, but also prevents contamination of the chamber. However, since most synthesis of HA-SWCNTs is performed in hot-wall reactors, adapting this well-established process to a cold-wall chamber becomes extremely crucial. Here, in order to transfer the CVD growth technology from a hot-wall to a cold-wall chamber, a systematic investigation has been conducted to determine the influence of process parameters on the HA-SWCNT's growth. For two reasons, the cold-wall CVD chamber was upgraded with a top heater to complement the bottom substrate heater; the first reason to maintain a more uniform temperature profile during HA-SWCNTs growth, and the second reason to preheat the precursor gas flow before projecting it onto the catalyst. Our results show that the addition of a top heater had a significant effect on the synthesis. Characterization of the CNTs shows that the average density of HA-SWCNTs is around 1 - 2 tubes/ μm with high growth quality as shown by Raman analysis. [Figure not available: see fulltext.

  9. Attitudes and beliefs regarding cardiovascular risk factors among Bangladeshi immigrants in the US.

    PubMed

    Patel, Mihir; Phillips-Caesar, Erica; Boutin-Foster, Carla

    2014-10-01

    The US has increasingly growing Bangladeshi population, a South Asian sub-ethnic group with a high prevalence of cardiovascular disease (CVD). We conducted a qualitative study using individual in-depth interviews to explore attitudes towards and difficulties with modifying CVD related behaviors among a Bangladeshi cohort. We interviewed 55 patients before reaching data saturation. Bangladeshis discussed the meaning of health and heart disease in the context of how disease can potentially impact their ability to care for their family. Behavioral and psychological factors were discussed as the causes of CVD. Internal forces and external forces were brought up to explain difficulties addressing the causes of CVD. Bangladeshi individuals in our study were aware of CVD, but felt unable to address behavioral risk factors. They cite a combination of internal and external factors as barriers to lifestyle modification. Interventions to address these barriers must simultaneously addressing self-efficacy and work-life balance. PMID:23861069

  10. Cardiovascular Disease and Associated Risk Factors in Cuba: Prospects for Prevention and Control

    PubMed Central

    Cooper, Richard S.; Orduñez, Pedro; Iraola Ferrer, Marcos D.; Munoz, Jose Luis Bernal; Espinosa-Brito, Alfredo

    2006-01-01

    Objectives. An adequate description of the trends in cardiovascular disease (CVD) is not available for most of the developing world. Cuba provides an important exception, and we sought to use available data to offer insights into the changing patterns of CVD there. Methods. We reviewed Cuban public health statistics, surveys, and reports of health services. Results. CVD has been the leading cause of death since 1970. A 45% reduction in heart disease deaths was observed from 1970 to 2002; the decline in stroke was more limited. There are moderate prevalences of all major risk factors. Conclusions. The Cuban medical care system has responded vigorously to the challenge of CVD; levels of control of hypertension are the highest in the world. Nonindustrialized countries can decisively control CVD. PMID:16317211

  11. Association of Risk Estimates of Three Different Cardiovascular Risk Assessment Tools with Carotid Intima Media Thickness in Patients with Type 2 Diabetes

    PubMed Central

    Weerarathna, Thilak Priyantha; Dulanjalee, Ranasinghe Bethmi Arachige Thilini; Jayawardana, Madumekala Rupasinghe; Edirisingha, Udara Priyadarshani; Rathnayake, Madushanka

    2016-01-01

    Introduction Risk assessment tools used to calculate the Cardiovascular Disease (CVD) risk such as the Framingham Risk Score (FRS), United Kingdom Prospective Diabetes study (UKPDS) risk engine and the World Health Organization (WHO) risk score have not been tested on their ability to detect subclinical atherosclerosis in most developing countries. Aim To study the association between the calculated CVD risk scores using each of these tools and Carotid Intima Medial Thickness (CIMT), a surrogate marker of atherosclerosis, in a group of patients with Type 2 diabetes (T2DM) in Sri Lanka. Materials and Methods We calculated CVD risk scores of 68 randomly selected patients with T2DM with no history or symptoms of CVD and measured their CIMT using B-mode ultrasonography (USS). Carotid USS was considered positive when the maximum carotid IMT was 0.9mm or when arteriosclerotic plaques were detected. The 10-year CVD risk was calculated using the FRS, the UKPDS risk engine and the WHO risk score. Pearson correlation was used to study the association between CVD risk scores with CIMT. Results Of the 68 patients studied, 50% were males and their mean age (SD) was 56.9 (±9.6) years. The mean age at onset and duration of diabetes were 44.3(±9.1) and 12.2(±7.6) years respectively. Of the scoring methods, UKPDS tool had weak, but significantly positive (r = 0.26, p < 0.05) and FRS had positive but not significant association (r= 0. 21) with CIMT. There was a negative association between CIMT and WHO risk score (r= - 0.07). Conclusion Of the three CVD risk assessment tools, both UKPDS risk engine and FRS have almost equal ability (former being marginally superior) in predicting underlying atherosclerotic vascular disease in patients with T2DM. Negative association of the WHO risk score with CIMT argues against its utility for CVD screening. These findings highlight the need for developing more sensitive and reliable CVD risk assessment tools for developing countries.

  12. The Rationale and Design of the Pharmacist Intervention for Low Literacy in Cardiovascular Disease (PILL-CVD) Study

    PubMed Central

    Schnipper, Jeffrey L.; Roumie, Christianne L.; Cawthon, Courtney; Businger, Alexandra; Dalal, Anuj K.; Mugalla, Ileko; Eden, Svetlana; Jacobson, Terry A.; Rask, Kimberly J.; Vaccarino, Viola; Gandhi, Tejal K.; Bates, David W.; Johnson, Daniel C.; Labonville, Stephanie; Gregory, David; Kripalani, Sunil

    2010-01-01

    Background Medication errors and adverse drug events are common after hospital discharge, due to changes in medication regimens, suboptimal discharge instructions, and prolonged time to follow-up. Pharmacist-based interventions may be effective in promoting the safe and effective use of medications, especially among high risk patients such as those with low health literacy. Methods and Results The Pharmacist Intervention for Low Literacy in Cardiovascular Disease (PILL-CVD) study is a randomized controlled trial conducted at 2 academic centers – Vanderbilt University Hospital and Brigham and Women’s Hospital. Patients admitted with acute coronary syndrome or acute decompensated heart failure were randomized to usual care or intervention. The intervention consisted of pharmacist-assisted medication reconciliation, inpatient pharmacist counseling, low-literacy adherence aids, and tailored telephone follow-up after discharge. The primary outcome is the occurrence of serious medication errors in the first 30 days after hospital discharge. Secondary outcomes are health care utilization, disease-specific quality of life, and cost effectiveness. Enrollment was completed September 2009. A total of 862 patients were enrolled, and 430 patients were randomized to receive the intervention. Analyses will determine whether the intervention was effective in reducing serious medication errors, particularly in patients with low health literacy. Conclusions The PILL-CVD study was designed to reduce serious medication errors after hospitalization through a pharmacist-based intervention. The intervention, if effective, will inform health care facilities on the use of pharmacist-assisted medication reconciliation, inpatient counseling, low-literacy adherence aids, and patient follow-up after discharge. Clinical Trial Registration http://clinicaltrials.gov/ct2/show/NCT00632021, NCT00632021 PMID:20233982

  13. Adherence to the 2006 American Heart Association Diet and Lifestyle Recommendations for cardiovascular disease risk reduction is associated with bone health in older Puerto Ricans

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cardiovascular disease (CVD) and osteoporosis are 2 major public health problems that share common pathophysiological mechanisms. It is possible that strategies to reduce CVD risk may also benefit bone health. We tested the hypothesis that adherence to the 2006 American Heart Association Diet and Li...

  14. Effects of diets differing in glycemic index and glycemic load on cardiovascular risk factors: review of randomized controlled-feeing trials

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Despite a considerable amount of data available on the relationship between dietary glycemic index (GI) or load (GL) and cardiovascular disease (CVD) risk factors, in aggregate, the area remains unsettled. The aim of the present review was to summarize the effect of diets differing in GI/GL on CVD r...

  15. Reduction in weight and cardiovascular diasease risk factors in individuals with type 2 diabetes: One-year results of the Look AHEAD trial

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effectiveness of intentional weight loss in reducing cardiovascular disease (CVD) events in type 2 diabetes is unknown. This report describes 1-year changes in CVD risk factors in a trial designed to examine the long-term effects of an intensive lifestyle intervention on the incidence of major C...

  16. Metabolically Healthy Obesity and the Risk of Cardiovascular Disease in the Elderly Population

    PubMed Central

    Koolhaas, Chantal M.; van Rossum, Elisabeth F. C.; Ikram, M. Arfan; Hofman, Albert; Kavousi, Maryam; Franco, Oscar H.

    2016-01-01

    Background Whether being metabolically healthy obese (MHO)—defined by the presence of obesity in the absence of metabolic syndrome—is associated with subsequent cardiovascular disease (CVD) remains unclear and may depend on the participants’ age. We examined the association of being MHO with CVD risk in the elderly. Methods and Findings This study included 5,314 individuals (mean age 68 years) from the prospective population-based Rotterdam Study. We categorized our population in groups according to body mass index (BMI) and presence and absence of metabolic syndrome, and estimated the hazard ratio (HR) and 95% confidence interval (95%CI) for every group by using Cox proportional hazard models. Among 1048 (19.7%) obese individuals we identified 260 (24.8%) MHO subjects. Over 14 years of follow-up there were 861 incident CVD cases. In the multivariable adjusted analysis, we did not observe an increased CVD risk in MHO individuals (HR 1.07, 95%CI 0.75–1.53), compared to normal weight individuals without metabolic syndrome. CVD risk was increased by the presence of metabolic syndrome in normal weight (HR 1.35, 95%CI 1.02–1.80), overweight (HR 1.32, 95%CI 1.09–1.60) and obese (HR 1.33, 95%CI 1.07–1.66) individuals, compared to those with normal weight without metabolic syndrome. In a mediation analysis, 71.3% of the association between BMI and CVD was explained by the presence of metabolic syndrome. Conclusions In our elderly population, we found that the presence of obesity without metabolic syndrome did not confer a higher CVD risk. However, metabolic syndrome was strongly associated with CVD risk, and was associated with an increased risk in all BMI categories. Therefore, preventive interventions targeting cardiometabolic risk factors could be considered in elderly, regardless of weight status. PMID:27100779

  17. Cardiovascular risk prediction: a comparative study of Framingham and quantum neural network based approach

    PubMed Central

    Narain, Renu; Saxena, Sanjai; Goyal, Achal Kumar

    2016-01-01

    Purpose Currently cardiovascular diseases (CVDs) are the main cause of death worldwide. Disease risk estimates can be used as prognostic information and support for treating CVDs. The commonly used Framingham risk score (FRS) for CVD prediction is outdated for the modern population, so FRS may not be accurate enough. In this paper, a novel CVD prediction system based on machine learning is proposed. Methods This study has been conducted with the data of 689 patients showing symptoms of CVD. Furthermore, the dataset of 5,209 CVD patients of the famous Framingham study has been used for validation purposes. Each patient’s parameters have been analyzed by physicians in order to make a diagnosis. The proposed system uses the quantum neural network for machine learning. This system learns and recognizes the pattern of CVD. The proposed system has been experimentally evaluated and compared with FRS. Results During testing, patients’ data in combination with the doctors’ diagnosis (predictions) are used for evaluation and validation. The proposed system achieved 98.57% accuracy in predicting the CVD risk. The CVD risk predictions by the proposed system, using the dataset of the Framingham study, confirmed the potential risk of death, deaths which actually occurred and had been recorded as due to myocardial infarction and coronary heart disease in the dataset of the Framingham study. The accuracy of the proposed system is significantly higher than FRS and other existing approaches. Conclusion The proposed system will serve as an excellent tool for a medical practitioner in predicting the risk of CVD. This system will be serving as an aid to medical practitioners for planning better medication and treatment strategies. An early diagnosis may be effectively made by using this system. An overall accuracy of 98.57% has been achieved in predicting the risk level. The accuracy is considerably higher compared to the other existing approaches. Thus, this system must be used

  18. Effect of current stress during thermal CVD of multilayer graphene on cobalt catalytic layer

    NASA Astrophysics Data System (ADS)

    Ueno, Kazuyoshi; Ichikawa, Hiroyasu; Uchida, Takaki

    2016-04-01

    To improve the crystallinity of multilayer graphene (MLG) by CVD at a low temperature, the effect of current stress during thermal CVD on a cobalt (Co) catalytic layer was investigated. The crystallinity of MLG obtained by CVD with current was higher than that without current at the same temperature. This indicates that current has effects besides the Joule heating effect. The current effects on the Co catalytic layer and the MLG growth reaction were investigated, and it was found that current had small effects on the grain size and crystal structure of the Co catalyst and large effects on the MLG growth reaction such as large grain growth and a low activation energy of 0.49 eV, which is close to the value reported for carbon surface diffusion on Co. It is considered that the enhancement of MLG growth reaction by current leads to the improved crystallinity of MLG at a relatively low temperature.

  19. Polymer Adsorption on Graphite and CVD Graphene Surfaces Studied by Surface-Specific Vibrational Spectroscopy.

    PubMed

    Su, Yudan; Han, Hui-Ling; Cai, Qun; Wu, Qiong; Xie, Mingxiu; Chen, Daoyong; Geng, Baisong; Zhang, Yuanbo; Wang, Feng; Shen, Y R; Tian, Chuanshan

    2015-10-14

    Sum-frequency vibrational spectroscopy was employed to probe polymer contaminants on chemical vapor deposition (CVD) graphene and to study alkane and polyethylene (PE) adsorption on graphite. In comparing the spectra from the two surfaces, it was found that the contaminants on CVD graphene must be long-chain alkane or PE-like molecules. PE adsorption from solution on the honeycomb surface results in a self-assembled ordered monolayer with the C-C skeleton plane perpendicular to the surface and an adsorption free energy of ∼42 kJ/mol for PE(H(CH2CH2)nH) with n ≈ 60. Such large adsorption energy is responsible for the easy contamination of CVD graphene by impurity in the polymer during standard transfer processes. Contamination can be minimized with the use of purified polymers free of PE-like impurities. PMID:26367247

  20. 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. PMID:26785633

  1. Onset conditions for gas phase reaction and nucleation in the CVD of transition metal oxides

    NASA Technical Reports Server (NTRS)

    Collins, J.; Rosner, D. E.; Castillo, J.

    1992-01-01

    A combined experimental/theoretical study is presented of the onset conditions for gas phase reaction and particle nucleation in hot substrate/cold gas CVD of transition metal oxides. Homogeneous reaction onset conditions are predicted using a simple high activation energy reacting gas film theory. Experimental tests of the basic theory are underway using an axisymmetric impinging jet CVD reactor. No vapor phase ignition has yet been observed in the TiCl4/O2 system under accessible operating conditions (below substrate temperature Tw = 1700 K). The goal of this research is to provide CVD reactor design and operation guidelines for achieving acceptable deposit microstructures at the maximum deposition rate while simultaneously avoiding homogeneous reaction/nucleation and diffusional limitations.

  2. Epitaxial thin film GaAs solar cells using OM-CVD techniques. [Organometallics

    NASA Technical Reports Server (NTRS)

    Stirn, R. J.; Wang, K. L.; Yeh, Y. C. M.

    1981-01-01

    A new approach has been initiated at JPL to fabricate thin-film, high efficiency GaAs solar cells on low-cost, single-crystal Si substrates having a thin CVD interlayer of Ge to minimize the lattice and thermal expansion mismatch. For initial experiments, n(+)/p GaAs cells were grown by OM-CVD on single-crystal GaAs and Ge wafers. Details of the growths and performance results will be presented. Subsequently, a combined epitaxial structure of OM-CVD GaAs on a strongly adherent Ge interlayer on (100) Si was grown. This is the first report of the successful growth of this composite structure. Low module costs projected by JPL SAMICS methodology calculations and the potential for 400-600W/kg space solar arrays will be discussed.

  3. Cold Vacuum Dryer (CVD) Facility Fire Protection System Design Description (SYS 24)

    SciTech Connect

    SINGH, G.

    2000-10-17

    This system design description (SDD) addresses the Cold Vacuum Drying (CVD) Facility fire protection system (FPS). The primary features of the FPS for the CVD are a fire alarm and detection system, automatic sprinklers, and fire hydrants. The FPS also includes fire extinguishers located throughout the facility and fire hydrants to assist in manual firefighting efforts. In addition, a fire barrier separates the operations support (administrative) area from the process bays and process bay support areas. Administrative controls to limit combustible materials have been established and are a part of the overall fire protection program. The FPS is augmented by assistance from the Hanford Fire Department (HED) and by interface systems including service water, electrical power, drains, instrumentation and controls. This SDD, when used in conjunction with the other elements of the definitive design package, provides a complete picture of the FPS for the CVD Facility.

  4. A direct comparison of CVD-grown and exfoliated MoS2 using optical spectroscopy

    NASA Astrophysics Data System (ADS)

    Plechinger, G.; Mann, J.; Preciado, E.; Barroso, D.; Nguyen, A.; Eroms, J.; Schüller, C.; Bartels, L.; Korn, T.

    2014-06-01

    MoS2 is a highly interesting material, which exhibits a crossover from an indirect band gap in the bulk crystal to a direct gap for single layers. Here, we perform a direct comparison between large-area MoS2 films grown by chemical vapor deposition (CVD) and MoS2 flakes prepared by mechanical exfoliation from mineral bulk crystal. Raman spectroscopy measurements show differences between the in-plane and out-of-plane phonon mode positions in CVD-grown and exfoliated MoS2. Photoluminescence (PL) mapping reveals large regions in the CVD-grown films that emit strong PL at room-temperature, and low-temperature PL scans demonstrate a large spectral shift of the A exciton emission as a function of position. Polarization-resolved PL measurements under near-resonant excitation conditions show a strong circular polarization of the PL, corresponding to a valley polarization.

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

    SciTech Connect

    Koynov, S.; Grebner, S.; Schwarz, R.; Vassilev, L.; Sieber, I.; Schmidt, M.; Fuhs, W.

    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 characterized 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.

  6. Association between the Family Nutrition and Physical Activity screening tool and cardiovascular disease risk factors in 10-year old children

    NASA Astrophysics Data System (ADS)

    Yee, Kimbo Edward

    Purpose. To examine the association of the Family Nutrition and Physical Activity (FNPA) screening tool, a behaviorally based screening tool designed to assess the obesogenic family environment and behaviors, with cardiovascular disease (CVD) risk factors in 10-year old children. Methods. One hundred nineteen children were assessed for body mass index (BMI), percent body fat (%BF), waist circumference (WC), total cholesterol, HDL-cholesterol, and resting blood pressure. A continuous CVD risk score was created using total cholesterol to HDL-cholesterol ratio (TC:HDL), mean arterial pressure (MAP), and WC. The FNPA survey was completed by parents. The associations between the FNPA score and individual CVD risk factors and the continuous CVD risk score were examined using correlation analyses. Results. Approximately 35% of the sample were overweight (19%) or obese (16%). The mean FNPA score was 24.6 +/- 2.5 (range 18 to 29). Significant correlations were found between the FNPA score and WC (r = -.35, p<.01), BMI percentile (r = -.38, p<.01), %BF (r = -.43, p<.01), and the continuous CVD risk score (r = -.22, p = .02). No significant association was found between the FNPA score and TC:HDL (r=0.10, p=0.88) or MAP (r=-0.12, p=0.20). Conclusion. Children from a high-risk, obesogenic family environment as indicated with a lower FNPA score have a higher CVD risk factor profile than children from a low-risk family environment.

  7. Construction, genotypic and phenotypic characterization, and immunogenicity of attenuated DeltaguaBA Salmonella enterica serovar Typhi strain CVD 915.

    PubMed

    Wang, J Y; Pasetti, M F; Noriega, F R; Anderson, R J; Wasserman, S S; Galen, J E; Sztein, M B; Levine, M M

    2001-08-01

    A promising live attenuated typhoid vaccine candidate strain for mucosal immunization was developed by introducing a deletion in the guaBA locus of pathogenic Salmonella enterica serovar Typhi strain Ty2. The resultant DeltaguaBA mutant, serovar Typhi CVD 915, has a gene encoding resistance to arsenite replacing the deleted sequence within guaBA, thereby providing a marker to readily identify the vaccine strain. CVD 915 was compared in in vitro and in vivo assays with wild-type strain Ty2, licensed live oral typhoid vaccine strain Ty21a, or attenuated serovar Typhi vaccine strain CVD 908-htrA (harboring mutations in aroC, aroD, and htrA). CVD 915 was less invasive than CVD 908-htrA in tissue culture and was more crippled in its ability to proliferate after invasion. In mice inoculated intraperitoneally with serovar Typhi and hog gastric mucin (to estimate the relative degree of attenuation), the 50% lethal dose of CVD 915 (7.7 x 10(7) CFU) was significantly higher than that of wild-type Ty2 (1.4 x 10(2) CFU) and was only slightly lower than that of Ty21a (1.9 x 10(8) CFU). Strong serum O and H antibody responses were recorded in mice inoculated intranasally with CVD 915, which were higher than those elicited by Ty21a and similar to those stimulated by CVD 908-htrA. CVD 915 also elicited potent proliferative responses in splenocytes from immunized mice stimulated with serovar Typhi antigens. Used as a live vector, CVD 915(pTETlpp) elicited high titers of serum immunoglobulin G anti-fragment C. These encouraging preclinical data pave the way for phase 1 clinical trials with CVD 915. PMID:11447145

  8. 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. PMID:26908050

  9. Cardiovascular risk, chronic obstructive pulmonary disease and pulmonary rehabilitation: Can we learn from cardiac rehabilitation?

    PubMed

    Triest, Filip Jj; Singh, Sally J; Vanfleteren, Lowie Egw

    2016-08-01

    Patients with chronic obstructive pulmonary disease (COPD) who participate in pulmonary rehabilitation (PR) often have concomitant cardiovascular disease (CVD), which is a frequently undiagnosed and undertreated comorbidity. CVD contributes to the burden of the disease and is associated with an increased risk for hospitalizations and mortality. Optimizing the diagnosis and management of cardiovascular risk and disease should be considered as part of the holistic approach of PR. In addition, we need to consider similarities and differences in cardiac and PR programs, in order to improve personalized care in patients with both diseases. The current review addresses the burden of CVD in COPD patients who participate in PR, how CVD and its risk factors affect PR and should be managed during PR, and extends on what we can learn of the organization of cardiac rehabilitation programs. PMID:27081189

  10. Behavioral Interventions and Cardiovascular Risk in Obese Youth: Current Findings and Future Directions

    PubMed Central

    Vannucci, Anna; Wilfley, Denise E.

    2012-01-01

    The identification and early intervention of pediatric obesity is critical to reducing cardiovascular disease (CVD). Family-based behavioral interventions have consistently demonstrated efficacy in reducing adiposity and CVD risk factors (i.e., blood pressure, cholesterol, fasting glucose levels, insulin resistance, metabolic syndrome). Even modest weight loss in severely obese youth can lead to sustained improvement in CVD risk factors. However, weight regain following treatment cessation remains a challenge in the contemporary obesogenic environment. Intensive family-based interventions spanning socioenvironmental contexts (i.e., home, peer, community) show promise in sustaining weight loss in the long-term. Despite having effective treatments for pediatric obesity and CVD risk factors, families rarely have access to these programs and so increasing the role of healthcare providers in screening and referral efforts is imperative. Moving forward, it is also essential to establish communication and cooperative networks across sectors build sustainable prevention and intervention programs and to provide cohesive health messages. PMID:23336013

  11. System for the growth of bulk SiC crystals by modified CVD techniques

    NASA Technical Reports Server (NTRS)

    Steckl, Andrew J.

    1994-01-01

    The goal of this program was the development of a SiC CVD growth of films thick enough to be useful as pseudo-substrates. The cold-walled CVD system was designed, assembled, and tested. Extrapolating from preliminary evaluation of SiC films grown in the system at relatively low temperatures indicates that the growth rate at the final temperatures will be high enough to make our approach practical. Modifications of the system to allow high temperature growth and cleaner growth conditions are in progress. This program was jointly funded by Wright Laboratory, Materials Directorate and NASA LeRC and monitored by NASA.

  12. A facile process for soak-and-peel delamination of CVD graphene from substrates using water

    PubMed Central

    Gupta, Priti; Dongare, Pratiksha D.; Grover, Sameer; Dubey, Sudipta; Mamgain, Hitesh; Bhattacharya, Arnab; Deshmukh, Mandar M.

    2014-01-01

    We demonstrate a simple technique to transfer chemical vapour deposited (CVD) graphene from copper and platinum substrates using a soak-and-peel delamination technique utilizing only hot deionized water. The lack of chemical etchants results in cleaner CVD graphene films minimizing unintentional doping, as confirmed by Raman and electrical measurements. The process allows the reuse of substrates and hence can enable the use of oriented substrates for growth of higher quality graphene, and is an inherently inexpensive and scalable process for large-area production. PMID:24457558

  13. A facile process for soak-and-peel delamination of CVD graphene from substrates using water

    NASA Astrophysics Data System (ADS)

    Gupta, Priti; Dongare, Pratiksha D.; Grover, Sameer; Dubey, Sudipta; Mamgain, Hitesh; Bhattacharya, Arnab; Deshmukh, Mandar M.

    2014-01-01

    We demonstrate a simple technique to transfer chemical vapour deposited (CVD) graphene from copper and platinum substrates using a soak-and-peel delamination technique utilizing only hot deionized water. The lack of chemical etchants results in cleaner CVD graphene films minimizing unintentional doping, as confirmed by Raman and electrical measurements. The process allows the reuse of substrates and hence can enable the use of oriented substrates for growth of higher quality graphene, and is an inherently inexpensive and scalable process for large-area production.

  14. Effects of Operating Conditions on the Deposition of GaAs in a Vertical Cvd Reactor

    NASA Astrophysics Data System (ADS)

    Baek, Jae-Sang; Boo, Jin-Hyo; Kim, Youn-Jea

    A numerical study is needed to gain insight into the growth mechanism and improve the reactor design or optimize the deposition condition in chemical vapor deposition (CVD). In this study, we have performed a numerical analysis of the deposition of gallium arsenide (GaAs) from trimethyl gallium (TMG) and arsine in a vertical CVD reactor. The effects of operating parameters, such as the rotation velocity of susceptor, inlet velocity, and inlet TMG fraction, are investigated and presented. The three-dimensional model which is used in this investigation includes complete coupling between the thermal-fluid transport and species transport with chemical reaction.

  15. Physics and applications of novel structures with CVD graphene: edges, grain boundaries, twisted bilayers, and hybrids

    NASA Astrophysics Data System (ADS)

    Chen, Yong P.

    2014-03-01

    In this talk, I will discuss experimental studies (including electronic transport, optical/Raman, and STM) of physical properties of various novel synthetic graphene structures formed in CVD graphene grown on Cu, including edges of graphene single crystals, grain boundaries between such single crystals, and twisted bilayer graphene. Such synthetic graphene structures could be used as playground to explore novel physics and engineer new functionalities in graphene based electronic devices. Furthermore, I will discuss graphene based ``hybrid'' materials combining CVD graphene with semiconductor and metallic nanostructures for potential optoelectronic and plasmonics applications.

  16. A numerical and experimental analysis of reactor performance and deposition rates for CVD on monofilaments

    NASA Technical Reports Server (NTRS)

    Gokoglu, S. A.; Kuczmarski, M.; Veitch, L.; Tsui, P.; Chait, A.

    1990-01-01

    The computational fluid dynamics (CFD) code FLUENT is adopted to simulate a cylindrical upflow reactor designed for chemical vapor deposition (CVD) on monofilaments. Equilibrium temperature profiles along the fiber and quartz reactor wall are experimentally measured and used as boundary conditions in numerical simulations. Two-dimensional axisymmetric flow and temperature fields are calculated for hydrogen and argon; the effect of free convection is assessed. The gas and surface chemistry is included for predicting silicon deposition from silane. The model predictions are compared with experimentally measured silicon CVD rates. Inferences are made for optimum conditions to obtain uniformity.

  17. Raman spectroscopic investigation of polycrystalline structures of CVD-grown graphene by isotope labeling

    NASA Astrophysics Data System (ADS)

    Wang, Shengnan; Suzuki, Satoru; Hibino, Hiroki

    2014-10-01

    Topological defects, such as point defects, dislocations and grain boundaries, have a dramatic influence on the chemical and physical properties of large-scale graphene grown by chemical vapor deposition (CVD) method. Here we demonstrate the Raman visualization of polycrystalline structures in an isotopically modified CVD graphene. By means of the reversible reaction of methane on a copper catalyst, the etching of 12C-lattice and surface deposition of 13C-atoms occur in CVD graphene by sequentially introducing hydrogen and isotopic methane after standard growth of graphene with full monolayer coverage. Spatial Raman spectroscopic mapping on labeled graphene reveals pronounced network-like 13C-rich regions, which are further identified to exist along the grain boundaries of graphene by low-energy electron microscopy. The structural defects inside the graphene grains are also targeted in the isotope labeling process. Our work opens a new way to investigate multiple grain structures in CVD graphene with a simple spectroscopic technique.Topological defects, such as point defects, dislocations and grain boundaries, have a dramatic influence on the chemical and physical properties of large-scale graphene grown by chemical vapor deposition (CVD) method. Here we demonstrate the Raman visualization of polycrystalline structures in an isotopically modified CVD graphene. By means of the reversible reaction of methane on a copper catalyst, the etching of 12C-lattice and surface deposition of 13C-atoms occur in CVD graphene by sequentially introducing hydrogen and isotopic methane after standard growth of graphene with full monolayer coverage. Spatial Raman spectroscopic mapping on labeled graphene reveals pronounced network-like 13C-rich regions, which are further identified to exist along the grain boundaries of graphene by low-energy electron microscopy. The structural defects inside the graphene grains are also targeted in the isotope labeling process. Our work opens a new

  18. Hot-Wire CVD Amorphous Si Materials for Solar Cell Application

    SciTech Connect

    Wang, Q.

    2009-01-01

    Hydrogenated amorphous silicon (a-Si:H) thin films and their application to solar cells fabricated using the hot-wire chemical vapor deposition (HWCVD) or (CAT)-CVD will be reviewed. This review will focus on the comparison to the standard plasma enhance (PE) CVD in the terms of deposition technique, film properties, and solar cell performance. The advantages of using HWCVD for a-Si:H solar cell research as well as the criteria for industry's adaptation of this technique for mass production will be addressed.

  19. Temperature threshold and water role in CVD growth of single-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Geng, Junfeng; Motta, Marcelo; Angels, Volker; Luo, Jikui; Johnson, Brian

    2016-02-01

    An in-depth understanding of the growth process of single walled carbon nanotubes is of vital importance to the control of the yield of the material and its carbon structure. Using a nickel/silica (Ni/SiOx) catalyst we have conducted a series of growth experiments with a chemical vapour deposition (CVD) system. We find that there is a temperature threshold in the CVD process, and if the reaction temperature sets above this threshold there will be no growth of the nanotubes. In association with this temperature effect, water plays an important role in the promotion or termination of the growth of single walled carbon nanotubes.

  20. Mediation of Cardiovascular Risk Factor Effects Through Subclinical Vascular Disease: The Multi-Ethnic Study of Atherosclerosis

    PubMed Central

    Yeboah, Joseph; Delaney, Joseph A; Nance, Robin; McClelland, Robyn L; Polak, Joseph F.; Sibley, Christopher T.; Bertoni, Alain; Burke, Gregory L; Carr, J. Jeffery; Herrington, David M.

    2015-01-01

    Objective It is unclear to what extent subclinical cardiovascular disease (CVD) such as coronary artery calcium (CAC), carotid intima-media thickness (CIMT) and brachial flow mediated dilation (FMD) are mediators of the known associations between traditional cardiovascular risk factors and incident CVD events. We assessed the portion of the effects of risk factors on incident CVD events that are mediated through CAC, CIMT and FMD. Approach and Results 6355 out of 6814 MESA participants were included. Nonlinear implementation of structural equation modeling (STATA mediation package) were used to assess whether CAC, CIMT or FMD are mediators of the association between traditional risk factors and incident CVD event. Mean age of 62, with 47% males, 12% diabetics and 13% current smokers. Mean follow up of 7.5 years, 539 CVD events were adjudicated. CAC showed the highest mediation while FMD showed the least. Age had the highest percent of total effect mediated via CAC for CVD outcomes while current cigarette smoking had the least percent of total effect mediated via CAC [percent (95%CI: 80.2(58.8, 126.7) % vs. 10.6(6.1, 38.5) % respectively). BMI showed the highest percent of total effect mediated via CIMT [17.7(11.6, 38.9) %], only a negligible amount of the association between traditional risk factors and CVD was mediated via FMD. Conclusion Many of the risk factors for incident CVD (other than age, sex and BMI) showed a modest level of mediation via CAC, CIMT and FMD suggesting that current subclinical CVD markers may not be optimal intermediaries for gauging upstream risk factor modification PMID:24876350

  1. Gyrokinetic Statistical Absolute Equilibrium and Turbulence

    SciTech Connect

    Jian-Zhou Zhu and Gregory W. Hammett

    2011-01-10

    A paradigm based on the absolute equilibrium of Galerkin-truncated inviscid systems to aid in understanding turbulence [T.-D. Lee, "On some statistical properties of hydrodynamical and magnetohydrodynamical fields," Q. Appl. Math. 10, 69 (1952)] is taken to study gyrokinetic plasma turbulence: A finite set of Fourier modes of the collisionless gyrokinetic equations are kept and the statistical equilibria are calculated; possible implications for plasma turbulence in various situations are discussed. For the case of two spatial and one velocity dimension, in the calculation with discretization also of velocity v with N grid points (where N + 1 quantities are conserved, corresponding to an energy invariant and N entropy-related invariants), the negative temperature states, corresponding to the condensation of the generalized energy into the lowest modes, are found. This indicates a generic feature of inverse energy cascade. Comparisons are made with some classical results, such as those of Charney-Hasegawa-Mima in the cold-ion limit. There is a universal shape for statistical equilibrium of gyrokinetics in three spatial and two velocity dimensions with just one conserved quantity. Possible physical relevance to turbulence, such as ITG zonal flows, and to a critical balance hypothesis are also discussed.

  2. Absolute surface energy for zincblende semiconductors

    NASA Astrophysics Data System (ADS)

    Zhang, S. B.; Wei, Su-Huai

    2003-03-01

    Recent advance in nanosciences requires the determination of surface (or facet) energy of semiconductors, which is often difficult due to the polar nature of some of the most important surfaces such as the (111)A/(111)B surfaces. Several approaches have been developed in the past [1-3] to deal with the problem but an unambiguous division of the polar surface energies is yet to come [2]. Here we show that an accurate division is indeed possible for the zincblende semiconductors and will present the results for GaAs, ZnSe, and CuInSe2 [4], respectively. A general trend emerges, relating the absolute surface energy to the ionicity of the bulk materials. [1] N. Chetty and R. M. Martin, Phys. Rev. B 45, 6074 (1992). [2] N. Moll, et al., Phys. Rev. B 54, 8844 (1996). [3] S. Mankefors, Phys. Rev. B 59, 13151 (1999). [4] S. B. Zhang and S.-H. Wei, Phys. Rev. B 65, 081402 (2002).

  3. Climate Absolute Radiance and Refractivity Observatory (CLARREO)

    NASA Technical Reports Server (NTRS)

    Leckey, John P.

    2015-01-01

    The Climate Absolute Radiance and Refractivity Observatory (CLARREO) is a mission, led and developed by NASA, that will measure a variety of climate variables with an unprecedented accuracy to quantify and attribute climate change. CLARREO consists of three separate instruments: an infrared (IR) spectrometer, a reflected solar (RS) spectrometer, and a radio occultation (RO) instrument. The mission will contain orbiting radiometers with sufficient accuracy, including on orbit verification, to calibrate other space-based instrumentation, increasing their respective accuracy by as much as an order of magnitude. The IR spectrometer is a Fourier Transform spectrometer (FTS) working in the 5 to 50 microns wavelength region with a goal of 0.1 K (k = 3) accuracy. The FTS will achieve this accuracy using phase change cells to verify thermistor accuracy and heated halos to verify blackbody emissivity, both on orbit. The RS spectrometer will measure the reflectance of the atmosphere in the 0.32 to 2.3 microns wavelength region with an accuracy of 0.3% (k = 2). The status of the instrumentation packages and potential mission options will be presented.

  4. Absolute decay width measurements in 16O

    NASA Astrophysics Data System (ADS)

    Wheldon, C.; Ashwood, N. I.; Barr, M.; Curtis, N.; Freer, M.; Kokalova, Tz; Malcolm, J. D.; Spencer, S. J.; Ziman, V. A.; Faestermann, Th; Krücken, R.; Wirth, H.-F.; Hertenberger, R.; Lutter, R.; Bergmaier, A.

    2012-09-01

    The reaction 126C(63Li, d)168O* at a 6Li bombarding energy of 42 MeV has been used to populate excited states in 16O. The deuteron ejectiles were measured using the high-resolution Munich Q3D spectrograph. A large-acceptance silicon-strip detector array was used to register the recoil and break-up products. This complete kinematic set-up has enabled absolute α-decay widths to be measured with high-resolution in the 13.9 to 15.9 MeV excitation energy regime in 16O; many for the first time. This energy region spans the 14.4 MeV four-α breakup threshold. Monte-Carlo simulations of the detector geometry and break-up processes yield detection efficiencies for the two dominant decay modes of 40% and 37% for the α+12C(g.s.) and a+12C(2+1) break-up channels respectively.

  5. Absolute calibration of forces in optical tweezers

    NASA Astrophysics Data System (ADS)

    Dutra, R. S.; Viana, N. B.; Maia Neto, P. A.; Nussenzveig, H. M.

    2014-07-01

    Optical tweezers are highly versatile laser traps for neutral microparticles, with fundamental applications in physics and in single molecule cell biology. Force measurements are performed by converting the stiffness response to displacement of trapped transparent microspheres, employed as force transducers. Usually, calibration is indirect, by comparison with fluid drag forces. This can lead to discrepancies by sizable factors. Progress achieved in a program aiming at absolute calibration, conducted over the past 15 years, is briefly reviewed. Here we overcome its last major obstacle, a theoretical overestimation of the peak stiffness, within the most employed range for applications, and we perform experimental validation. The discrepancy is traced to the effect of primary aberrations of the optical system, which are now included in the theory. All required experimental parameters are readily accessible. Astigmatism, the dominant effect, is measured by analyzing reflected images of the focused laser spot, adapting frequently employed video microscopy techniques. Combined with interface spherical aberration, it reveals a previously unknown window of instability for trapping. Comparison with experimental data leads to an overall agreement within error bars, with no fitting, for a broad range of microsphere radii, from the Rayleigh regime to the ray optics one, for different polarizations and trapping heights, including all commonly employed parameter domains. Besides signaling full first-principles theoretical understanding of optical tweezers operation, the results may lead to improved instrument design and control over experiments, as well as to an extended domain of applicability, allowing reliable force measurements, in principle, from femtonewtons to nanonewtons.

  6. Absolute spectrophotometry of northern compact planetary nebulae

    NASA Astrophysics Data System (ADS)

    Wright, S. A.; Corradi, R. L. M.; Perinotto, M.

    2005-06-01

    We present medium-dispersion spectra and narrowband images of six northern compact planetary nebulae (PNe): BoBn 1, DdDm 1, IC 5117, M 1-5, M 1-71, and NGC 6833. From broad-slit spectra, total absolute fluxes and equivalent widths were measured for all observable emission lines. High signal-to-noise emission line fluxes of Hα, Hβ, [Oiii], [Nii], and HeI may serve as emission line flux standards for northern hemisphere observers. From narrow-slit spectra, we derive systemic radial velocities. For four PNe, available emission line fluxes were measured with sufficient signal-to-noise to probe the physical properties of their electron densities, temperatures, and chemical abundances. BoBn 1 and DdDm 1, both type IV PNe, have an Hβ flux over three sigma away from previous measurements. We report the first abundance measurements of M 1-71. NGC 6833 measured radial velocity and galactic coordinates suggest that it is associated with the outer arm or possibly the galactic halo, and its low abundance ([O/H]=1.3× 10-4) may be indicative of low metallicity within that region.

  7. Dietary behaviors of adults born prematurely may explain future risk for cardiovascular disease.

    PubMed

    Sharafi, Mastaneh; Duffy, Valerie B; Miller, Robin J; Winchester, Suzy B; Huedo-Medina, Tania B; Sullivan, Mary C

    2016-04-01

    Being born prematurely associates with greater cardiovascular disease (CVD) risk in adulthood. Less understood are the unique and joint associations of dietary patterns and behaviors to this elevated risk among adults who are born prematurely. We aimed to model the associations between term status, dietary and lifestyle behaviors with CVD risk factors while accounting for the longitudinal effects of family protection, and medical or environmental risks. In wave-VIII of a longitudinal study, 23-year olds born prematurely (PT-adults, n = 129) and full term (FT-adults, n = 38) survey-reported liking for foods/beverages and activities, constructed into indexes of dietary quality and sensation-seeking, dietary restraint and physical activity. Measured CVD risk factors included fasting serum lipids and glucose, blood pressure and adiposity. In bivariate relationships, PT-adults reported lower dietary quality (including less affinity for protein-rich foods and higher affinity for sweets), less liking for sensation-seeking foods/activities, and less restrained eating than did FT-adults. In comparison to nationally-representative values and the FT-adults, PT-adults showed greater level of CVD risk factors for blood pressure and serum lipids. In structural equation modeling, dietary quality completely mediated the association between term status and HDL-cholesterol (higher quality, lower HDL-cholesterol) yet joined term status to explain variability in systolic blood pressure (PT-adults with lowest dietary quality had highest blood pressures). Through lower dietary quality, being born prematurely was indirectly linked to higher cholesterol/HDL, higher LDL/HDL and elevated waist/hip ratios. The relationship between dietary quality and CVD risk was strongest for PT-adults who had developed greater cumulative medical risk. Protective environments failed to attenuate relationships between dietary quality and elevated CVD risk among PT-adults. In summary, less healthy dietary

  8. Absolute nuclear material assay using count distribution (LAMBDA) space

    DOEpatents

    Prasad, Mano K.; Snyderman, Neal J.; Rowland, Mark S.

    2015-12-01

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  9. Absolute nuclear material assay using count distribution (LAMBDA) space

    DOEpatents

    Prasad, Manoj K.; Snyderman, Neal J.; Rowland, Mark S.

    2012-06-05

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  10. Association Between Physical Activity and Risk of All-Cause Mortality and Cardiovascular Disease in Patients With Diabetes

    PubMed Central

    Kodama, Satoru; Tanaka, Shiro; Heianza, Yoriko; Fujihara, Kazuya; Horikawa, Chika; Shimano, Hitoshi; Saito, Kazumi; Yamada, Nobuhiro; Ohashi, Yasuo; Sone, Hirohito

    2013-01-01

    OBJECTIVE The association between habitual physical activity (PA) and lowered risk of all-cause mortality (ACM) and cardiovascular disease (CVD) has been suggested in patients with diabetes. This meta-analysis summarizes the risk reduction in relation to PA, focusing on clarifying dose-response associations. RESEARCH DESIGN AND METHODS Electronic literature searches were conducted for cohort studies that examined relative risk (RR) of ACM or CVD in relation to PA in patients with diabetes. For the qualitative assessment, RR for the highest versus the lowest PA category in each study was pooled with a random-effects model. We added linear and spline regression analyses to assess the quantitative relationship between increases in PA and ACM and CVD risk. RESULTS There were 17 eligible studies. Qualitatively, the highest PA category had a lower RR [95% CI] for ACM (0.61 [0.52–0.70]) and CVD (0.71 [0.60–0.84]) than the lowest PA category. The linear regression model indicated a high goodness of fit for the risk of ACM (adjusted R2 = 0.44, P = 0.001) and CVD (adjusted R2 = 0.51, P = 0.001), with the result that a 1 MET-h/day incrementally higher PA was associated with 9.5% (5.0–13.8%) and 7.9% (4.3–11.4%) reductions in ACM and CVD risk, respectively. The spline regression model was not significantly different from the linear model in goodness of fit (P = 0.14 for ACM risk; P = 0.60 for CVD risk). CONCLUSIONS More PA was associated with a larger reduction in future ACM and CVD risk in patients with diabetes. Nevertheless, any amount of habitual PA was better than inactivity. PMID:23349151

  11. Impact of socioeconomic deprivation on screening for cardiovascular disease risk in a primary prevention population: a cross-sectional study

    PubMed Central

    Abel, Gary A; Mant, Jonathan; Mullis, Ricky

    2016-01-01

    Objectives Investigate the association between socioeconomic deprivation and completeness of cardiovascular disease (CVD) risk factor recording in primary care, uptake of screening in people with incomplete risk factor recording and with actual CVD risk within the screened subgroup. Design Cross-sectional study. Setting Nine UK general practices. Participants 7987 people aged 50–74 years with no CVD diagnosis. Methods CVD risk was estimated using the Framingham equation from data extracted from primary care electronic health records. Where there was insufficient information to calculate risk, patients were invited to attend a screening assessment. Analysis Proportion of patients for whom clinical data were sufficiently complete to enable CVD risk to be calculated; proportion of patients invited to screening who attended; proportion of patients who attended screening whose 10-year risk of a cardiovascular event was high (>20%). For each outcome, a set of logistic regression models were run. Crude and adjusted ORs were estimated for person-level deprivation, age, gender and smoking status. We included practice-level deprivation as a continuous variable and practice as a random effect to account for clustering. Results People who had lower Indices of Multiple Deprivation (IMD) scores (less deprived) had significantly worse routine CVD risk factor recording (adjusted OR 0.97 (0.95 to 1.00) per IMD decile; p=0.042). Screening attendance was poorer in those with more deprivation (adjusted OR 0.89 (0.86 to 0.91) per IMD decile; p<0.001). Among those who attended screening, the most deprived were more likely to have CVD risk >20% (OR 1.09 (1.03 to 1.15) per IMD decile; p=0.004). Conclusions Our data suggest that those who had the most to gain from screening were least likely to attend, potentially exacerbating existing health inequalities. Future research should focus on tailoring the delivery of CVD screening to ensure engagement of socioeconomically deprived groups

  12. Estimation of the burden of cardiovascular disease attributable to modifiable risk factors and cost-effectiveness analysis of preventative interventions to reduce this burden in Argentina

    PubMed Central

    2010-01-01

    Background Cardiovascular disease (CVD) is the primary cause of mortality and morbidity in Argentina representing 34.2% of deaths and 12.6% of potential years of life lost (PYLL). The aim of the study was to estimate the burden of acute coronary heart disease (CHD) and stroke and the cost-effectiveness of preventative population-based and clinical interventions. Methods An epidemiological model was built incorporating prevalence and distribution of high blood pressure, high cholesterol, hyperglycemia, overweight and obesity, smoking, and physical inactivity, obtained from the Argentine Survey of Risk Factors dataset. Population Attributable Fraction (PAF) of each risk factor was estimated using relative risks from international sources. Total fatal and non-fatal events, PYLL and Disability Adjusted Life Years (DALY) were estimated. Costs of event were calculated from local utilization databases and expressed in international dollars (I$). Incremental cost-effectiveness ratios (ICER) were estimated for six interventions: reducing salt in bread, mass media campaign to promote tobacco cessation, pharmacological therapy of high blood pressure, pharmacological therapy of high cholesterol, tobacco cessation therapy with bupropion, and a multidrug strategy for people with an estimated absolute risk > 20% in 10 years. Results An estimated total of 611,635 DALY was lost due to acute CHD and stroke for 2005. Modifiable risk factors explained 71.1% of DALY and more than 80% of events. Two interventions were cost-saving: lowering salt intake in the population through reducing salt in bread and multidrug therapy targeted to persons with an absolute risk above 20% in 10 years; three interventions had very acceptable ICERs: drug therapy for high blood pressure in hypertensive patients not yet undergoing treatment (I$ 2,908 per DALY saved), mass media campaign to promote tobacco cessation amongst smokers (I$ 3,186 per DALY saved), and lowering cholesterol with statin drug therapy

  13. Fire Hazard Analysis for the Cold Vacuum Drying (CVD) Facility

    SciTech Connect

    JOHNSON, B.H.

    1999-08-19

    This Fire Hazard Analysis assesses the risk from fire within individual fire areas in the Cold Vacuum Drying Facility at the Hanford Site in relation to existing or proposed fire protection features to ascertain whether the objectives of DOE Order 5480.7A Fire Protection are met.

  14. The absolute disparity anomaly and the mechanism of relative disparities.

    PubMed

    Chopin, Adrien; Levi, Dennis; Knill, David; Bavelier, Daphne

    2016-06-01

    There has been a long-standing debate about the mechanisms underlying the perception of stereoscopic depth and the computation of the relative disparities that it relies on. Relative disparities between visual objects could be computed in two ways: (a) using the difference in the object's absolute disparities (Hypothesis 1) or (b) using relative disparities based on the differences in the monocular separations between objects (Hypothesis 2). To differentiate between these hypotheses, we measured stereoscopic discrimination thresholds for lines with different absolute and relative disparities. Participants were asked to judge the depth of two lines presented at the same distance from the fixation plane (absolute disparity) or the depth between two lines presented at different distances (relative disparity). We used a single stimulus method involving a unique memory component for both conditions, and no extraneous references were available. We also measured vergence noise using Nonius lines. Stereo thresholds were substantially worse for absolute disparities than for relative disparities, and the difference could not be explained by vergence noise. We attribute this difference to an absence of conscious readout of absolute disparities, termed the absolute disparity anomaly. We further show that the pattern of correlations between vergence noise and absolute and relative disparity acuities can be explained jointly by the existence of the absolute disparity anomaly and by the assumption that relative disparity information is computed from absolute disparities (Hypothesis 1). PMID:27248566

  15. The absolute disparity anomaly and the mechanism of relative disparities

    PubMed Central

    Chopin, Adrien; Levi, Dennis; Knill, David; Bavelier, Daphne

    2016-01-01

    There has been a long-standing debate about the mechanisms underlying the perception of stereoscopic depth and the computation of the relative disparities that it relies on. Relative disparities between visual objects could be computed in two ways: (a) using the difference in the object's absolute disparities (Hypothesis 1) or (b) using relative disparities based on the differences in the monocular separations between objects (Hypothesis 2). To differentiate between these hypotheses, we measured stereoscopic discrimination thresholds for lines with different absolute and relative disparities. Participants were asked to judge the depth of two lines presented at the same distance from the fixation plane (absolute disparity) or the depth between two lines presented at different distances (relative disparity). We used a single stimulus method involving a unique memory component for both conditions, and no extraneous references were available. We also measured vergence noise using Nonius lines. Stereo thresholds were substantially worse for absolute disparities than for relative disparities, and the difference could not be explained by vergence noise. We attribute this difference to an absence of conscious readout of absolute disparities, termed the absolute disparity anomaly. We further show that the pattern of correlations between vergence noise and absolute and relative disparity acuities can be explained jointly by the existence of the absolute disparity anomaly and by the assumption that relative disparity information is computed from absolute disparities (Hypothesis 1). PMID:27248566

  16. Importance of cardiovascular disease risk management in patients with type 2 diabetes mellitus

    PubMed Central

    Lorber, Daniel

    2014-01-01

    Type 2 diabetes mellitus (T2DM) is commonly accompanied by other cardiovascular disease (CVD) risk factors, such as hypertension, obesity, and dyslipidemia. Furthermore, CVD is the most common cause of death in people with T2DM. It is therefore of critical importance to minimize the risk of macrovascular complications by carefully managing modifiable CVD risk factors in patients with T2DM. Therapeutic strategies should include lifestyle and pharmacological interventions targeting hyperglycemia, hypertension, dyslipidemia, obesity, cigarette smoking, physical inactivity, and prothrombotic factors. This article discusses the impact of modifying these CVD risk factors in the context of T2DM; the clinical evidence is summarized, and current guidelines are also discussed. The cardiovascular benefits of smoking cessation, increasing physical activity, and reducing low-density lipoprotein cholesterol and blood pressure are well established. For aspirin therapy, any cardiovascular benefits must be balanced against the associated bleeding risk, with current evidence supporting this strategy only in certain patients who are at increased CVD risk. Although overweight, obesity, and hyperglycemia are clearly associated with increased cardiovascular risk, the effect of their modification on this risk is less well defined by available clinical trial evidence. However, for glucose-lowering drugs, further evidence is expected from several ongoing cardiovascular outcome trials. Taken together, the evidence highlights the value of early intervention and targeting multiple risk factors with both lifestyle and pharmacological strategies to give the best chance of reducing macrovascular complications in the long term. PMID:24920930

  17. Reducing the modifiable risks of cardiovascular disease in Turkish patients with type 2 diabetes: the effectiveness of training.

    PubMed

    Bayındır Çevik, Ayfer; Özcan, Şeyda; Satman, İlhan

    2015-06-01

    Our goal was to reduce the number of modifiable risk factors for cardiovascular disease (CVD) through providing lifestyle adjustment training and counseling to patients with type 2 diabetes. In this pre-post intervention study, 139 patients with diabetes were provided with training to reduce the modifiable risks of CVD. One hundred three patients attended the post-training evaluation. Two phone counseling sessions were provided with 1-month intervals. Consumption of red meat and processed food decreased and water consumption, carrying on the recommended diet, and the frequency of exercise increased (p = .000), A1C decreased (p = .05), and the use of aspirin increased (p = .03). Thus, a contribution to the reduction of CVD risk factors in patients with type 2 diabetes was achieved. The training program for reducing CVD risk factors in patients with type 2 diabetes was effective in improving nutrition and lifestyle behaviors and decreasing glycemic control. PMID:24789940

  18. Orion Absolute Navigation System Progress and Challenge

    NASA Technical Reports Server (NTRS)

    Holt, Greg N.; D'Souza, Christopher

    2012-01-01

    The absolute navigation design of NASA's Orion vehicle is described. It has undergone several iterations and modifications since its inception, and continues as a work-in-progress. This paper seeks to benchmark the current state of the design and some of the rationale and analysis behind it. There are specific challenges to address when preparing a timely and effective design for the Exploration Flight Test (EFT-1), while still looking ahead and providing software extensibility for future exploration missions. The primary onboard measurements in a Near-Earth or Mid-Earth environment consist of GPS pseudo-range and delta-range, but for future explorations missions the use of star-tracker and optical navigation sources need to be considered. Discussions are presented for state size and composition, processing techniques, and consider states. A presentation is given for the processing technique using the computationally stable and robust UDU formulation with an Agee-Turner Rank-One update. This allows for computational savings when dealing with many parameters which are modeled as slowly varying Gauss-Markov processes. Preliminary analysis shows up to a 50% reduction in computation versus a more traditional formulation. Several state elements are discussed and evaluated, including position, velocity, attitude, clock bias/drift, and GPS measurement biases in addition to bias, scale factor, misalignment, and non-orthogonalities of the accelerometers and gyroscopes. Another consideration is the initialization of the EKF in various scenarios. Scenarios such as single-event upset, ground command, and cold start are discussed as are strategies for whole and partial state updates as well as covariance considerations. Strategies are given for dealing with latent measurements and high-rate propagation using multi-rate architecture. The details of the rate groups and the data ow between the elements is discussed and evaluated.

  19. Evaluation of the Absolute Regional Temperature Potential

    NASA Technical Reports Server (NTRS)

    Shindell, D. T.

    2012-01-01

    The Absolute Regional Temperature Potential (ARTP) is one of the few climate metrics that provides estimates of impacts at a sub-global scale. The ARTP presented here gives the time-dependent temperature response in four latitude bands (90-28degS, 28degS-28degN, 28-60degN and 60-90degN) as a function of emissions based on the forcing in those bands caused by the emissions. It is based on a large set of simulations performed with a single atmosphere-ocean climate model to derive regional forcing/response relationships. Here I evaluate the robustness of those relationships using the forcing/response portion of the ARTP to estimate regional temperature responses to the historic aerosol forcing in three independent climate models. These ARTP results are in good accord with the actual responses in those models. Nearly all ARTP estimates fall within +/-20%of the actual responses, though there are some exceptions for 90-28degS and the Arctic, and in the latter the ARTP may vary with forcing agent. However, for the tropics and the Northern Hemisphere mid-latitudes in particular, the +/-20% range appears to be roughly consistent with the 95% confidence interval. Land areas within these two bands respond 39-45% and 9-39% more than the latitude band as a whole. The ARTP, presented here in a slightly revised form, thus appears to provide a relatively robust estimate for the responses of large-scale latitude bands and land areas within those bands to inhomogeneous radiative forcing and thus potentially to emissions as well. Hence this metric could allow rapid evaluation of the effects of emissions policies at a finer scale than global metrics without requiring use of a full climate model.

  20. Absolute optical surface measurement with deflectometry

    NASA Astrophysics Data System (ADS)

    Li, Wansong; Sandner, Marc; Gesierich, Achim; Burke, Jan

    Deflectometry utilises the deformation and displacement of a sample pattern after reflection from a test surface to infer the surface slopes. Differentiation of the measurement data leads to a curvature map, which is very useful for surface quality checks with sensitivity down to the nanometre range. Integration of the data allows reconstruction of the absolute surface shape, but the procedure is very error-prone because systematic errors may add up to large shape deviations. In addition, there are infinitely many combinations for slope and object distance that satisfy a given observation. One solution for this ambiguity is to include information on the object's distance. It must be known very accurately. Two laser pointers can be used for positioning the object, and we also show how a confocal chromatic distance sensor can be used to define a reference point on a smooth surface from which the integration can be started. The used integration algorithm works without symmetry constraints and is therefore suitable for free-form surfaces as well. Unlike null testing, deflectometry also determines radius of curvature (ROC) or focal lengths as a direct result of the 3D surface reconstruction. This is shown by the example of a 200 mm diameter telescope mirror, whose ROC measurements by coordinate measurement machine and deflectometry coincide to within 0.27 mm (or a sag error of 1.3μm). By the example of a diamond-turned off-axis parabolic mirror, we demonstrate that the figure measurement uncertainty comes close to a well-calibrated Fizeau interferometer.