The effect of age on the unfolding of elastin lamellae and collagen fibers with stretch in human carotid arteries

1981 ◽  
Vol 59 (10) ◽  
pp. 1050-1057 ◽  
Author(s):  
Zenon J. Samila ◽  
Stefan A. Carter
Keyword(s):  
Elastic Properties ◽  
Carotid Arteries ◽  
Collagen Fibers ◽  
Low Degrees ◽  
First Time ◽  
The Relationship ◽  
Effect Of Age ◽  
Human Carotid

We measured folding of elastin lamellae and collagen fibers in human carotid arteries and correlated the results with the elastic properties of the vessels. Specimens cut into circumferential strips were stretched to various degrees, fixed, and stained for elastin and collagen. Folding was measured on photographic projections. Elastin lamellae unfolded quickly with initial stretch. In old vessels they did not straighten as much as in the young suggesting that the content of the interlamellar space may interfere with the unfolding. Collagen fibers straightened more during stretch in stiffer older vessels than in the young, already at low degrees of stretch. Young's modulus at extension of 5% appeared to correlate with unfolding of elastin lamellae in young extensible vessels. The modulus correlated significantly with unfolding of collagen fibers at extensions of 15% and greater, and the slope of the regression of the modulus on folding increased with stretch. Our findings provide for the first time morphologic evidence for the role of elastin lamellae in the determination of the elastic properties at low extensions, for the importance of collagen fibers in increasing stiffness with further stretch, and for the relationship between increased stiffness with age and the earlier recruitment of the collagen fibers.

scholarly journals Exploring Secondary Metabolite Profiles of Stachybotrys spp. by LC-MS/MS

Toxins ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 133 ◽  
Author(s):  
Annika Jagels ◽  
Viktoria Lindemann ◽  
Sebastian Ulrich ◽  
Christoph Gottschalk ◽  
Benedikt Cramer ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Future Research ◽  
Structural Modifications ◽  
Metabolite Profiles ◽  
The Individual ◽  
First Time ◽  
Analytical Standards ◽  
Respective Species

The genus Stachybotrys produces a broad diversity of secondary metabolites, including macrocyclic trichothecenes, atranones, and phenylspirodrimanes. Although the class of the phenylspirodrimanes is the major one and consists of a multitude of metabolites bearing various structural modifications, few investigations have been carried out. Thus, the presented study deals with the quantitative determination of several secondary metabolites produced by distinct Stachybotrys species for comparison of their metabolite profiles. For that purpose, 15 of the primarily produced secondary metabolites were isolated from fungal cultures and structurally characterized in order to be used as analytical standards for the development of an LC-MS/MS multimethod. The developed method was applied to the analysis of micro-scale extracts from 5 different Stachybotrys strains, which were cultured on different media. In that process, spontaneous dialdehyde/lactone isomerization was observed for some of the isolated secondary metabolites, and novel stachybotrychromenes were quantitatively investigated for the first time. The metabolite profiles of Stachybotrys species are considerably influenced by time of growth and substrate availability, as well as the individual biosynthetic potential of the respective species. Regarding the reported adverse effects associated with Stachybotrys growth in building environments, combinatory effects of the investigated secondary metabolites should be addressed and the role of the phenylspirodrimanes re-evaluated in future research.

scholarly journals MIGRATION, WAR, AND THE MAKING OF A TRANSNATIONAL LEBANESE SHIʿI COMMUNITY IN SENEGAL

2010 ◽  
Vol 42 (2) ◽  
pp. 269-290 ◽  
Author(s):  
Mara A. Leichtman
Keyword(s):  
National Identity ◽  
Public Opinion ◽  
Turning Point ◽  
West African ◽  
Local Responses ◽  
Religious Rituals ◽  
Political Ties ◽  
First Time ◽  
The Relationship

The July 2006 Lebanon war was an important turning point for West African Lebanese. For the first time since their formation as a community, the Lebanese in Senegal organized a demonstration in Dakar displaying solidarity with Lebanon. This protest illuminates the dynamics between global forces and local responses. Hizbullah's effectiveness in winning the international public opinion of both Sunni and Shiʿi Muslims in the war against Israel led to a surge in Lebanese diaspora identification, even among communities who had not been similarly affected by previous Lebanese wars. By analyzing the role of a Lebanese shaykh in bringing religious rituals and a Lebanese national identity to the community in Senegal, this article explores how members of the community maintain political ties to Lebanon even when they have never visited the “homeland” and sheds new light on the relationship among religion, migration, and (trans)nationalism.

The Role of Locally Produced and Digitally Animated Cartoons in the Process of Acquisition of Social Values

2019 ◽  
pp. 195-208
Author(s):  
Pınar Özgökbel Bilis ◽  
Ali Emre Bilis
Keyword(s):  
Qualitative Analysis ◽  
Social Values ◽  
Moral Values ◽  
Analysis Method ◽  
Television Channel ◽  
The Social ◽  
The Media ◽  
The Relationship

Television channels for children contain many cartoons and programs. These productions reach the viewers via both the television and the channel's official website. TRT Çocuk, broadcasting for children as a government television channel, presents many locally produced animated cartoons to the viewers. A product of the modern and digital technology, these locally produced cartoons carry importance in terms of transfer of social values. This study focuses on locally produced animation cartoons that have an important potential especially in the transfer of national and moral values. Determination of values conveyed via cartoons that bear importance in the transformation of television into an educational tool allows the media and child relationships to become visible. This work aims to examine the relationship between media and values by defining the concept of “value.” After creating a corporate frame, the study brings to light the social values conveyed in locally produced cartoons aired on TRT Çocuk television channel via qualitative analysis method.

scholarly journals Skin Electrical Resistance Measurement of Oxygen-Containing Terpenes as Penetration Enhancers: Role of Stratum Corneum Lipids

Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 523 ◽  
Author(s):  
Xue-min Zhu ◽  
Yu Li ◽  
Fei Xu ◽  
Wei Gu ◽  
Guo-jun Yan ◽  
...  
Keyword(s):  
Stratum Corneum ◽  
Electrical Resistance ◽  
Attenuated Total Reflection ◽  
Penetration Enhancers ◽  
Rapid Screening ◽  
Factors Affecting ◽  
Skin Cell ◽  
First Time

The measurement of skin electrical resistance (SER) has drawn a great deal of attention for the rapid screening of transdermal penetration enhancers (PEs). However, the mechanisms underlying the SER measurement are still unclear. This study was to investigate the effects and mechanisms of seven oxygen-containing terpenes on the SER kinetics. Stratum corneum (SC) lipids were proved to play a key role in SER measurement. Then, the factors affecting the SER measurement were optimized. By the determination of SER kinetics, cyclic terpenes (1,8-cineole, terpinen-4-ol, menthol and α-terpineol) were demonstrated to possess higher enhancement ratio (ER) values compared with linear terpenes (linalool, geraniol and citral). For the first time, the linear correlation was found between ER of terpenes and the interaction energy of terpene–ceramide complexes revealed by molecular simulation. The attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) analysis revealed that the effect of cyclic terpenes on SC lipid arrangement was obviously stronger than that of linear terpenes. In addition, by evaluating HaCaT skin cell viability, little difference was found between the toxicities of cyclic and linear terpenes. In conclusion, measurement of SER could be a feasible approach for the efficient evaluation of the PEs that mainly act on SC lipids.

An increase in activated NKT-CD8+ cells is associated with the presence of hypoechoic carotid plaques

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
V Genkel ◽  
I Baturina ◽  
I Emelyanov ◽  
I Shaposhnik ◽  
I Dolgushin
Keyword(s):  
Carotid Arteries ◽  
Roc Analysis ◽  
Carotid Atherosclerosis ◽  
Duplex Ultrasound ◽  
Atherosclerotic Plaques ◽  
Carotid Plaques ◽  
Cd8 Cells ◽  
The Relationship ◽  
Pro Inflammatory Cytokines

Abstract Background The role of NK-cells and NKT-cells and their subtypes at various stages of the development of atherosclerosis is poorly understood. It was previously shown that CD3+CD56+CD8+ cells can secrete pro-inflammatory cytokines and an increase in their number has been established in patients with active Behçet's Disease and Multiple Sclerosis. Purpose To study the relationship between the number of activated CD3+CD56+CD8+ cells and the echogenicity of plaques in patients with carotid atherosclerosis. Methods The study included 40 patients, 21 (52.5%) men and 19 (47.5%) women who underwent carotid ultrasound and immunological studies. The median age was 53.5 (46.7; 57.0) years. All patients underwent duplex ultrasound scanning of the carotid arteries. If an atherosclerotic plaque was detected, its image was saved and exported to Adobe Photoshop CS6® followed by analysis of the gray-scale median (GSM) of the plaque. Hypoechoic was considered a carotid plaque whose GSM values were less than 50. The number of CD3+CD56+CD8+CD11b+ cells was evaluated by flow cytometry using a flow cytometer. Results Among the examined patients, carotid plaques were detected in 31 (77.5%) participants. The average values of GSM visualized plaques were 58.0 (46.0; 71.5). Atherosclerotic plaques with GSM <50 were detected in 11 (35.5%) patients. In patients with hypoechoic carotid plaques, the number of CD3+CD56+CD8+CD11b+ cells was statistically significantly higher – 352 (55.0; 505) cells/uL versus 66.0 (15.5; 138) cells/uL in patients with plaques whose GSM values were more than 50 (p=0.020). Based on the results of correlation analysis it was established inverse relationship between number of CD3+CD56+CD8+CD11b+ cells and GSM of plaques (r=−0.427; p=0.016). According to the results of the ROC-analysis, an increase in the number of activated NKT-CD8+ cells over 46.5 cells/uL was a predictor of the presence of hypoechogenic carotid plaques with a sensitivity of 81.8% and a specificity of 45.0% (see Figure 1). Conclusion In patients with hypoechoic carotid plaques, the number of CD3+CD56+CD8+CD11b+ cells was significantly higher in comparison with other patients. An increase in the number of activated NKT-CD8+ cells over 46.5 cells/uL was a predictor of the presence of hypoechoic carotid plaques with sensitivity of 81.8% and specificity of 45.0% Figure 1 Funding Acknowledgement Type of funding source: None

The mediating role of maladaptive perfectionism in the association between psychological control and learned helplessness

2017 ◽  
Vol 20 (2) ◽  
pp. 113-126 ◽  
Author(s):  
Pina Filippello ◽  
Rosalba Larcan ◽  
Luana Sorrenti ◽  
Caterina Buzzai ◽  
Susanna Orecchio ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Learned Helplessness ◽  
Psychological Control ◽  
Parental Psychological Control ◽  
Mediating Role ◽  
Maladaptive Perfectionism ◽  
Relevant Role ◽  
First Time ◽  
The Relationship

Despite the extensive research on parental psychological control, no study has explored the relation between parental and teacher psychological control, maladaptive perfectionism and learned helplessness (LH). The purpose of this study was to investigate (1) whether perceived teacher psychological control predicts positively LH, (2) whether perceived parental psychological control predicts maladaptive perfectionism, and (3) whether the association between perceived parental and teacher psychological control and LH is mediated by maladaptive perfectionism. In a sample of 433 participants, 268 females (61.9%) and 165 males (38.1%), ranged in age from 13 to 19 years ( M = 15.38, standard deviation (SD) = 1.18), it was found that teacher psychological control has a more relevant role in the prediction of LH than parental control. Moreover, maladaptive perfectionism was a full mediator of the relationship between perceptions of teacher psychological control and LH. These results extend previous studies on teacher psychological control and, for the first time, provide evidence for the relation with LH, identifying maladaptive perfectionism as a variable that accounts for the relation between teacher psychological control and LH.

Filament Fragmentation Phenomena

1989 ◽  
Vol 170 ◽  
Author(s):  
Juan C. Figueroa ◽  
Linda S. Schadler ◽  
Campbell Laird
Keyword(s):  
Strain Energy ◽  
Stress Transfer ◽  
Fiber Surface ◽  
Yield Information ◽  
The Matrix ◽  
Two Parameters ◽  
The Relationship

AbstractThe effect of fiber surface treatments on the relationship between the tensile strength of a filament and the shear strength of its interphase is one of the central issues facing composite materials technologists today. We demonstrate here that analysis of fragmentation phenomena in monofilament composites can simultaneously yield information about these two parameters. Characterization of shear stress transfer zones in non-critical fragments has led us to the determination of interphase strength.A phenomenological treatment that highlights the role of the matrix in the fragmentation process is presented here. This analysis considers issues such as the strain energy exchange between a failing fiber and the matrix, as well as interphase relaxation due to the viscoelastic nature of the matrix. Our observations of the fragmentation phenomena in AU4/polycarbonate monofilament composites indicate that the fiber/matrix interaction in this system is governed by micromechanical locking.

scholarly journals Ultrasonic estimation of gestation age in goats via placentomes diameter

2017 ◽  
Vol 40 (2) ◽  
pp. 100-106
Author(s):  
Yaseen Mahmood Rasheed
Keyword(s):  
Linear Array ◽  
Early Recognition ◽  
Array Transducer ◽  
Gestation Age ◽  
Starting Point ◽  
Linear Probe ◽  
Significant Difference ◽  
First Time ◽  
The Relationship

     The aim of the present study is to establish the relationship between gestational age and placentome measurement via real-time ultrasound. This study is conducted in the college of Veterinary Medicine at Diyala University. Seventeen multiparous does were synchronized for estrus and naturally served to obtain pregnancy and subsequently scanned using both transducers. Ultrasonic (U.S) examination was performed transabdominally (TA) with sector-probe (5MHz) and transrectally (TR) with linear-probe (7.5MHz), in 10 day interval done started from day 35-135 post mating. The placentome was observed for the first time on day 35 by using TR ultrasonic examination (7.5MHz) linear transducer, as echogenic densities on the surface of endometrium. The results showed a significant increased (P≤0.05) in placentomes growth with gestation age. The placentome diameter (PD) reached maximized size around days 126 (39.6±2.37mm). Also, the results indicated significant difference between placentome diameter (PD) size in single and twin-pregnant does at (P≤0.05). The average of PD size in the single and twin-pregnant does was, respectively, 7.5±0.41mm and 9.2±0.74 mm at the day 35 and 45 of gestation. The maximal size of PD was 39.2±2.50mm in singleton-bearing does during 116-125 day and 41.0±2.19 mm in twin-bearing does during 126-135 day of gestation. In conclusion, the determination of gestation age according to placentome measurement was not reliable after day 90. Also, the use of 7.5 MHz linear array transducer for TR examination was found to be efficient, for early recognition of placentomes starting point from 35 days of gestation, as well as, the larger placentomes are expected in twins-bearing does. 

scholarly journals Event History Analysis for Investigating the Likelihood and Timing of Changing Majors

2018 ◽  
Vol 38 (1) ◽  
pp. 47-60 ◽  
Author(s):  
Jeffrey C. Sklar
Keyword(s):  
Event History Analysis ◽  
Student Characteristics ◽  
Event History ◽  
First Year ◽  
First Year Students ◽  
History Analysis ◽  
Enrollment Data ◽  
First Time ◽  
The Relationship

Students change their majors for various reasons, and academic advisors often assume the role of facilitating that change through institutional agreements or contracts. Therefore, advisors need to identify time periods during enrollment with the greatest likelihood that students will seek to change majors. They must also examine the student characteristics associated with changing majors so that advisors can identify students to avoid delays to graduation. The relationship between student characteristics and the likelihood of changing majors over time was studied through event history analysis techniques applied to enrollment data for a cohort of first-time first-year students.

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