| 1. |
- Huang, Daming, et al.
(författare)
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A Modified Charge-Pumping Method for the Characterization of Interface-Trap Generation in MOSFETs
- 2009
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Ingår i: IEEE Transactions on Electron Devices. - 0018-9383. ; 56:2, s. 267-274
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Tidskriftsartikel (refereegranskat)abstract
- A novel recovery-free interface-trap measurement method is presented in detail. This method is the modification of the conventional charge pumping (CP) by extending the pulse low level to the stress-bias and minimizing the pulse high-level duty cycle to suppress the recovery effect. The method is applied to study the negative-bias temperature instability in p-MOSFETs. As compared with the conventional CP, a much larger interface-trap generation under stress is observed by the new method. A power law time dependence (similar to t(n)) of interface-trap generation is observed. The index n. is less than that derived from conventional CP and increases with temperature, demonstrating a dispersive process involved in the trap generation dynamics.
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| 2. |
- Ambring, Anneli, 1964-, et al.
(författare)
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Mediterranean-inspired diet lowers the ratio of serum phospholipid n-6 to n-3 fatty acids, the number of leukocytes and platelets, and vascular endothelial growth factor in healthy subjects.
- 2006
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Ingår i: The American journal of clinical nutrition. - 0002-9165. ; 83:3, s. 575-81
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Reduced cardiovascular mortality and morbidity have been shown in persons adhering to Mediterranean-inspired diets (MIDs). Although the underlying mechanisms of this association are poorly understood, the importance of increasing dietary amounts of polyunsaturated fatty acids of the n-3 series has been emphasized. OBJECTIVE: We investigated whether a MID provided to healthy subjects would affect 1) the inflammatory process and endothelial indexes such as vasoregulation and vascular endothelial growth factor (VEGF) and 2) serum phospholipid fatty acid composition. DESIGN: A total of 22 subjects (10 women) received a MID or an ordinary Swedish diet (OSD) for 4 wk in a crossover fashion. Concentrations of lipids and fatty acids, high-sensitivity C-reactive protein, and interleukin 6, both before and after lipopolysaccharide stimulation; the number of leukocytes and platelets; and VEGF and monocyte chemoattractant protein 1 were analyzed. RESULTS: The plasma ratio of n-6 to n-3 fatty acids was substantially lower after the MID than after the OSD (x +/- SEM: 4.72 +/- 0.19 and 2.60 +/- 0.17, respectively; P < 0.0001). Neither C-reactive protein nor interleukin 6 concentrations changed significantly after the MID compared with the OSD. The total number of leukocytes and platelets was 10% (P < 0.05) and 15% (P < 0.001) lower, respectively, after the MID than after the OSD. Serum VEGF concentrations were lower after the MID than after the OSD (237 +/- 30 and 206 +/- 25 pg/mL, respectively; P = 0.0014). CONCLUSIONS: A MID reduces the number of platelets and leukocytes and VEGF concentrations in healthy subjects. This may be linked to higher serum concentrations of n-3 fatty acids, which promote a favorable composition of phospholipids.
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| 3. |
- Andersson, Irene, 1978-, et al.
(författare)
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Endothelial dysfunction in growth hormone transgenic mice
- 2006
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Ingår i: Clin Sci (Lond). - 0143-5221. ; 110:2, s. 217-25
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Tidskriftsartikel (refereegranskat)abstract
- Acromegaly [overproduction of GH (growth hormone)] is associated with cardiovascular disease. Transgenic mice overexpressing bGH (bovine GH) develop hypertension and hypercholesterolaemia and could be a model for cardiovascular disease in acromegaly. The aims of the present study were to investigate the effects of excess GH on vascular function and to test whether oxidative stress affects endothelial function in bGH transgenic mice. We studied the ACh (acetylcholine)-induced relaxation response in aortic and carotid rings of young (9-11 weeks) and aged (22-24 weeks) female bGH transgenic mice and littermate control mice, without and with the addition of a free radical scavenger {MnTBAP [Mn(III)tetrakis(4-benzoic acid)porphyrin chloride]}. We also measured mRNA levels of eNOS (endothelial nitric oxide synthase) and EC-SOD (extracellular superoxide dismutase). Intracellular superoxide anion production in the vascular wall was estimated using a dihydroethidium probe. Carotid arteries from bGH transgenic mice had an impaired ACh-induced relaxation response (young, 46 +/- 7% compared with 69 +/- 8%; aged, 52 +/- 5% compared with 80 +/- 3%; P < 0.05), whereas endothelial function in aorta was intact in young but impaired in aged bGH transgenic mice. Endothelial dysfunction was corrected by addition of MnTBAP in carotid arteries from young mice and in aortas from aged mice; however, MnTBAP did not correct endothelial dysfunction in carotid arteries from aged bGH transgenic mice. There was no difference in intracellular superoxide anion production between bGH transgenic mice and control mice, whereas mRNA expression of EC-SOD and eNOS was increased in aortas from young bGH transgenic mice compared with control mice (P < 0.05). We interpret these data to suggest that bGH overexpression is associated with a time- and vessel-specific deterioration in endothelial function, initially caused by increased oxidative stress and later by other alterations in vascular function.
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| 4. |
- Andersson, Irene, 1978-, et al.
(författare)
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Increased atherosclerotic lesion area in apoE deficient mice overexpressing bovine growth hormone
- 2006
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Ingår i: Atherosclerosis. - 0021-9150. ; 188:2, s. 331-40
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Tidskriftsartikel (refereegranskat)abstract
- Human growth hormone (GH) excess is linked to increased cardiovascular morbidity and mortality. However, little is known about the effect of GH excess on atherosclerosis. We developed a new mouse model to assess the hypothesis that GH overexpression accelerates atherosclerotic lesion formation. apoE(-/-) mice were crossed with bovine GH (bGH) transgenic mice to yield apoE(-/-) mice overexpressing bGH (apoE(-/-)/bGH). The mice were fed either standard or Western diet. At 22 weeks, atherosclerotic lesion area of thoracic aorta was larger in apoE(-/-)/bGH mice compared with littermate apoE(-/-) mice fed either diet (standard: +161+/-50%, Western: +430+/-134%). Aortic sinus lesions were more severe in apoE(-/-)/bGH mice fed standard diet compared with littermate apoE(-/-) mice. apoE(-/-)/bGH mice had lower (VLDL+LDL)/HDL ratios compared with littermate apoE(-/-) mice, while systolic blood pressure was higher in apoE(-/-)/bGH mice, irrespective of diet. The levels of serum amyloid A and hepatic CRP mRNA were higher in apoE(-/-)/bGH mice than in littermate apoE(-/-) mice. In conclusion, this study shows that excess GH augments the development of atherosclerosis in apoE(-/-) mice. The mechanisms could be direct effects of GH on cellular processes in the vessel wall or the result of concomitant processes such as hypertension or a general inflammatory state.
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| 5. |
- Bernberg, Evelina, 1981-, et al.
(författare)
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Effects of social isolation and environmental enrichment on atherosclerosis in ApoE-/- mice.
- 2008
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Ingår i: Stress (Amsterdam, Netherlands). - 1607-8888. ; 11:5, s. 381-9
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Tidskriftsartikel (refereegranskat)abstract
- Social support and a stimulating environment have been suggested to reduce stress reactions and cardiovascular risk. The aim of this study was to assess the role of environmental enrichment and social interaction for development of atherosclerosis in atherosclerosis prone mice. Male ApoE-/- mice were divided into four groups and followed during 20 weeks: (i) enriched environment (E, n=12), (ii) deprived environment (ED, n=12), (iii) enriched environment with exercise (E-Ex, n=12) and (iv) socially deprived by individual housing (SD, n=10). Plasma lipid and cytokine concentrations were measured. Atherosclerosis was quantified in cross-sections of innominate artery and en face in thoracic aorta. Plaque area was significantly increased in SD mice in the innominate artery (P<0.05 vs. all other groups), but not in the thoracic aorta. Plasma lipids were increased in SD mice (P<0.001 vs. all for total cholesterol, P<0.05 vs. E and P<0.01 vs. ED for triglycerides). Plasma concentration of granulocyte-colony stimulating factor (G-CSF) was decreased in SD mice compared to E mice (P<0.05). Thus, social isolation increased atherosclerosis and plasma lipids in ApoE-/- mice. Reduction in plasma G-CSF levels may hamper endothelial regeneration in the atherosclerotic process. While environmental enrichment did not affect atherosclerosis, social isolation accelerated atherosclerosis.
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| 6. |
- Chen, Yun, 1966-, et al.
(författare)
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High levels of soluble intercellular adhesion molecule-1, insulin resistance and saturated fatty acids are associated with endothelial dysfunction in healthy adolescents.
- 2010
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Ingår i: Atherosclerosis. - 1879-1484. ; 211:2, s. 638
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Atherosclerosis begins and progresses during childhood and adolescence. Endothelial dysfunction is one of the earliest abnormalities that can be detected in the development of atherosclerosis. As the determinants of endothelial function in childhood are unknown, we investigated the influence of cardiovascular risk factors on endothelial function in a cohort of healthy adolescents. METHODS: A total of 257 adolescents (age: 14.5+/-1.0 years, 138 girls) participated in this study. Endothelial function was measured as reactive hyperemic index (RHI) using a fingertip peripheral arterial tonometry device. Blood samples were collected for analysis of lipids, insulin, glucose, fatty acid composition of plasma phospholipids, and markers of inflammation and endothelial function. RESULTS: There was no gender difference in RHI. Boys had higher plasma level of vascular cellular adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), P-selectin and monocyte chemoattractant protein-1, and lower level of insulin, total cholesterol, high-density lipoprotein-cholesterol (HDL), low-density lipoprotein-cholesterol (LDL), ApoA1, ApoB, and docosahexaenoic acid of plasma phospholipids than girls. There was no gender difference regarding triacylglycerol, triacylglycerol/HDL, LDL/HDL and ApoB/ApoA. The RHI was inversely associated with plasma ICAM-1 (p=0.0003), HOMA index for insulin resistance (HOMA-IR, p=0.001) and saturated fatty acids of plasma phospholipids (SFA, p=0.001). The associations remained significant after adjusting for age, height, BMI-z-score, sex, blood pressure, HDL and smoking. CONCLUSION: In healthy adolescents impaired endothelial function is significantly associated with high level of soluble ICAM-1, HOMA-IR and SFA.
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| 7. |
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| 8. |
- Dangardt, Frida, 1977-, et al.
(författare)
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Omega-3 fatty acid supplementation improves vascular function and reduces inflammation in obese adolescents.
- 2010
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Ingår i: Atherosclerosis. - 1879-1484. ; 212:2, s. 580
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Tidskriftsartikel (refereegranskat)abstract
- Compared to normal weight adolescents, obese adolescents have lower serum omega-3 (n-3) polyunsaturated fatty acid (PUFA) concentrations, augmented inflammatory activity and endothelial dysfunction. We wanted to assess whether n-3 supplementation increases the serum n-3 PUFA concentration, improves vascular function and morphology, and lowers inflammation in obese adolescents.
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| 9. |
- Gabrielsson, Britt G., 1957-, et al.
(författare)
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Dietary herring improves plasma lipid profiles and reduces atherosclerosis in obese low-density lipoprotein receptor-deficient mice
- 2012
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Ingår i: International Journal of Molecular Medicine. - 1107-3756. ; 29:3, s. 331-37
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Tidskriftsartikel (refereegranskat)abstract
- Diet is a significant modifiable risk factor for cardiovascular disease and high fish intake has been associated with vascular health in population studies. However, intervention studies have been inconclusive. In this study, male low-density lipoprotein receptor-deficient mice were given 16-week high fat/high sucrose diets, supplemented with either minced herring fillets or minced beef. The diets were matched in total fat and cholesterol content; taurine content and fatty acid composition was analysed. Body weights were recorded throughout the study; plasma lipids were analysed at week 8 and 16. Body composition and adipocyte size were evaluated at study end. Atherosclerosis was evaluated at week 12 (ultrasound) and at termination (en face histology). Herring-fed mice had a higher proportion of long-chain n-3 polyunsaturated fatty acids in the hepatic triacylglycerides (TAG) and phospholipid fractions. The herring-fed mice had increased body weight (P=0.007), and reduced epididymal adipocyte size (P=0.009), despite similar food intake and body composition as the beef-fed mice. The herring-fed mice had lower plasma TAG and very-low-density lipoprotein (VLDL)-cholesterol concentrations throughout the study (TAG; P=0.0012 and 0.004, VLDL-cholesterol; P=0.006 and 0.041, week 8 and 16, respectively). At week 16, the herring-fed had higher plasma concentrations of HDL-cholesterol (P=0.004) and less atherosclerotic lesions in the aortic arch (P=0.007) compared with the beef-fed mice. In conclusion, dietary herring in comparison to beef markedly improved vascular health in this mouse model, suggesting that herring provides an added value beyond its content of macronutrients.
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| 10. |
- Gan, Li-Ming, 1969-, et al.
(författare)
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A short period of apnoea causes a marked increase in coronary flow velocity: a transthoracic pulsed wave Doppler study.
- 2005
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Ingår i: Clinical physiology and functional imaging. - 1475-0961. ; 25:3, s. 148-51
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Tidskriftsartikel (refereegranskat)abstract
- Coronary artery flow velocity during a short period of apnoea was investigated by transthoracic Doppler recording in 10 healthy men, aged 24-52. During breath holding for 29 +/- 6 s the oxygen saturation in the finger, measured by pulse oxymetry, decreased from 97.5 +/- 0.8 to 90.0 +/- 3.2% (P < 0.001). The maximal coronary blood flow velocity in the left anterior descending artery increased by 62% from 0.26 +/- 0.09 to 0.42 +/- 0.10 m s(-1) and the mean diastolic flow velocity by 47% from 0.19 +/- 0.04 to 0.28 +/- 0.08 m s(-1) (P < 0.001). In most subjects the increase of velocity started already after a few seconds of apnoea. Besides theoretical implications the results show that it is very important to be aware of the higher velocity during apnoea in order to avoid misinterpretation when using breath holding during magnetic resonance imaging or Doppler recording of coronary flow.
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