scholarly journals Age-related increase in wall stress of the human abdominal aorta: An in vivo study

2005 ◽  
Vol 42 (5) ◽  
pp. 926-931 ◽  
Author(s):  
Håkan Åstrand ◽  
Åsa Rydén-Ahlgren ◽  
Tomas Sandgren ◽  
Toste Länne
2011 ◽  
Vol 110 (1) ◽  
pp. 176-187 ◽  
Author(s):  
H. Åstrand ◽  
J. Stålhand ◽  
J. Karlsson ◽  
M. Karlsson ◽  
B. Sonesson ◽  
...  

The mechanical properties of the aorta affect cardiac function and are related to cardiovascular morbidity/mortality. This study was designed to evaluate the isotropic (mainly elastin, elastiniso) and anisotropic (mainly collagen, collagenani) material parameters within the human aorta in vivo. Thirty healthy men and women in three different age categories (23–30, 41–54, and 67–72 yr) were included. A novel mechanical model was used to identify the mechanical properties and the strain field with aid of simultaneously recorded pressure and radius in the abdominal aorta. The magnitudes of the material parameters relating to both the stiffness of elastiniso and collagenani were in agreement with earlier in vitro studies. The load-bearing fraction attributed to collagenani oscillated from 10 to 30% between diastolic and systolic pressures during the cardiac cycle. With age, stiffness of elastiniso increased in men, despite the decrease in elastin content that has been found due to elastolysis. Furthermore, an increase in stiffness of collagenani at high physiological pressure was found. This might be due to increased glycation, as well as changed isoforms of collagen in the aortic wall with age. A marked sex difference was observed, with a much less age-related effect, both on elastiniso and collagenani stiffness in women. Possible factors of importance could be the effect of sex hormones, as well as differing collagen isoforms, between the sexes.


2017 ◽  
Vol 139 ◽  
pp. 412-428 ◽  
Author(s):  
Rosana Leiva ◽  
Christian Griñan-Ferré ◽  
Constantí Seira ◽  
Elena Valverde ◽  
Andrew McBride ◽  
...  

Author(s):  
М.А. ЗАЗИМКО ◽  
Н.Н. ЗАБАШТА ◽  
Е.Н. ГОЛОВКО ◽  
И.А. СИНЕЛЬЩИКОВА ◽  
Е.П. ЛИСОВИЦКАЯ

Изучено влияние обогащения рациона бычков калмыцкой породы наноразмерными частицами микроэлементов в составе ультрадисперсных порошков металлов на мясное сырье. Нанопорошок железа получен химико-металлургическим способом низкотемпературного восстановления в потоке водорода гидроксидов и оксидов железа в ультрадисперсном состоянии до наночастиц с последующей пассивацией. По принципу пар-аналогов сформировали 2 группы бычков по 12 голов ― контрольную и опытную с живой массой молодняка, соответственно, 175,5±7,5 и 173,5±5,2 кг. Введение в рацион добавки, содержащей 0,08 мг железа на 1 кг живой массы в состав комбикорма для бычков на откорме в возрасте 6―18 мес путем его опрыскивания, позволило обогатить мышечную ткань животных эссенциальным железом, улучшить нутриентный состав говядины для детского и функционального питания. Установлено возрастное увеличение содержания общего белка в сыворотке крови бычков в контроле ― от 79,0±1,4 г/л в 6 мес до 85,0±1,1 в 18 мес и в опытной группе ― от 80,0±1,4 до 86,0±1,1 г/л соответственно. Количество альбуминов с возрастом увеличивалось: в контроле ― от 48,01±1,05 г/л в 6 мес до 52,03±1,10 в 18 мес и в опытной группе ― от 49,02±1,14 г/л в 6 мес до 52,02±1,13 г/л в 18 мес. Установлено двукратное повышение содержания железа в длиннейшей мышце туш опытных бычков, которое составило 89,29 мг/кг железа. Установлена возможность прижизненного обогащения говядины железом более, чем в 2 раза. The influence of enriching the diet of Kalmyk gobies with nanosized particles of microelements in the composition of ultra-dispersed metal powders meat raw materials has been studied. Iron nanopowder was obtained by the chemical-metallurgical method of low-temperature reduction in a hydrogen flow of hydroxides and iron oxides in an ultradispersed state to nanoparticles with subsequent passivation. According to the principle of analog pairs, 2 groups of gobies 12 heads each were formed ― control and experimental ― with the live weight of young animals, respectively, 175.5±7.5 and 173.5±5.2 kg. The introduction into the diet of an additive containing 0.08 mg of iron per 1 kg of live weight in the composition of feed for fattening bulls at the age of 6―18 months by spraying it, made it possible to enrich the muscle tissue of animals with essential iron, improve the nutrient composition of beef for baby and functional nutrition. An age-related increase in the concentration of total protein in the blood serum of gobies in the control was determined ― from 79.0±1.4 g/l at 6 months to 85.0±1.1 g/l at 18 months and in the experimental group ― from 80.0±1.4 to 86.0±1.1 g/l, respectively. The number of albumin increased with the age: in the control ― from 48.0±1.17 g/l at 6 months to 52.0±1.19 g/l at 18 months and in the experimental group ― from 49.0±1.16 g/l at 6 months to 52,0±1.18 g/l at 18 months A twofold increase in the iron content in the longest muscle of the back of experimental gobies was determined, which amounted to 89.29 mg/kg of iron. The possibility of in vivo enrichment of beef with iron by more than 2 times has been determined.


2013 ◽  
Vol 126 (8) ◽  
pp. 581-592 ◽  
Author(s):  
Gwenael Layec ◽  
Joel D. Trinity ◽  
Corey R. Hart ◽  
Seong-Eun Kim ◽  
Henderik Jonathan Groot ◽  
...  

The present study reveals that impaired skeletal muscle efficiency potentially contributes to the age-related decline in exercise capacity and may explain the altered haemodynamic response to exercise in the elderly.


2012 ◽  
Vol 83 (6) ◽  
pp. 875-888 ◽  
Author(s):  
Lukas Horny ◽  
Tomas Adamek ◽  
Rudolf Zitny

2009 ◽  
Vol 25 (2) ◽  
pp. 269-274 ◽  
Author(s):  
Mihaela Antonina Calin ◽  
S. V. Parasca

1989 ◽  
Vol 93 (3) ◽  
pp. 353-357 ◽  
Author(s):  
Catherine Escoffier ◽  
Jean de Rigal ◽  
Annie Rochefort ◽  
Regis Vasselet ◽  
Jean-Luc Leveque ◽  
...  

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