Elastomers in the Human Body

1966 ◽  
Vol 39 (4) ◽  
pp. 1288-1292 ◽  
Author(s):  
R. D. Falb ◽  
G. A. Grode ◽  
R. I. Leininger

Abstract Several problems arise when polymeric materials are placed in the body: (1) damage to the body such as blood coagulation, hemolysis, and protein denaturation, and (2) degradation of the polymers caused by exposure to the body's enzyme system. Several methods are presented in this paper to produce elastomeric materials that do not cause clotting of blood. This is accomplished by chemically binding a mucopolysaccharide (heparin) to their surfaces. The materials that have been treated in the work are silicone rubber, polyester polyurethan rubber, natural rubber, and butadiene pyridine rubber.

2020 ◽  
Author(s):  
IB Ushakov ◽  
AN Parfyonov ◽  
RA Bondarenko ◽  
VN Komarevtsev

The authors formulated a hypothesis about an important link in the pathogenesis of COVID-19, in which the increasing hypoxia and an acute response of the body like a general adaptation syndrome, accompanied by systemic pathological changes, including dangerous disorders of rheology and blood coagulation, play a key role.


2019 ◽  
pp. 3-13
Author(s):  
Alexandru Cîtea ◽  
George-Sebastian Iacob

Posture is commonly perceived as the relationship between the segments of the human body upright. Certain parts of the body such as the cephalic extremity, neck, torso, upper and lower limbs are involved in the final posture of the body. Musculoskeletal instabilities and reduced postural control lead to the installation of nonstructural posture deviations in all 3 anatomical planes. When we talk about the sagittal plane, it was concluded that there are 4 main types of posture deviation: hyperlordotic posture, kyphotic posture, rectitude and "sway-back" posture.Pilates method has become in the last decade a much more popular formof exercise used in rehabilitation. The Pilates method is frequently prescribed to people with low back pain due to their orientation on the stabilizing muscles of the pelvis. Pilates exercise is thus theorized to help reactivate the muscles and, by doingso, increases lumbar support, reduces pain, and improves body alignment.


Humaniora ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 83-90
Author(s):  
Anak Agung Ayu Wulandari ◽  
Ade Ariyani Sari Fajarwati

The research would look further at the representation of the human body in both Balinese and Javanese traditional houses and compared the function and meaning of each part. To achieve the research aim, which was to evaluate and compare the representation of the human body in Javanese and Balinese traditional houses, a qualitative method through literature and descriptive analysis study was conducted. A comparative study approach would be used with an in-depth comparative study. It would revealed not only the similarities but also the differences between both subjects. The research shows that both traditional houses represent the human body in their way. From the architectural drawing top to bottom, both houses show the same structure that is identical to the human body; head at the top, followed by the body, and feet at the bottom. However, the comparative study shows that each area represents a different meaning. The circulation of the house is also different, while the Balinese house is started with feet and continued to body and head area. Simultaneously, the Javanese house is started with the head, then continued to body, and feet area.


2021 ◽  
pp. 1354067X2110040
Author(s):  
Josefine Dilling ◽  
Anders Petersen

In this article, we argue that certain behaviour connected to the attempt to attain contemporary female body ideals in Denmark can be understood as an act of achievement and, thus, as an embodiment of the culture of achievement, as it is characterised in Præstationssamfundet, written by the Danish sociologist Anders Petersen (2016) Hans Reitzels Forlag . Arguing from cultural psychological and sociological standpoints, this article examines how the human body functions as a mediational tool in different ways from which the individual communicates both moral and aesthetic sociocultural ideals and values. Complex processes of embodiment, we argue, can be described with different levels of internalisation, externalisation and materialisation, where the body functions as a central mediator. Analysing the findings from a qualitative experimental study on contemporary body ideals carried out by the Danish psychologists Josefine Dilling and Maja Trillingsgaard, this article seeks to anchor such theoretical claims in central empirical findings. The main conclusions from the study are used to structure the article and build arguments on how expectations and ideals expressed in an achievement society become embodied.


Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 799
Author(s):  
Justyna Miedzianowska ◽  
Marcin Masłowski ◽  
Przemysław Rybiński ◽  
Krzysztof Strzelec

Increasingly, raw materials of natural origin are used as fillers in polymer composites. Such biocomposites have satisfactory properties. To ensure above-average functional properties, modifications of biofillers with other materials are also used. The presented research work aimed to produce and characterize elastomeric materials with a straw-based filler and four different types of montmorillonite. The main research goal was to obtain improved functional parameters of vulcanizates based on natural rubber. A series of composites filled with straw and certain types of modified and unmodified nano-clays in various ratios and amounts were prepared. Then, they were subjected to a series of tests to assess the impact of the hybrids used on the final product. It has been shown that the addition of optimal amounts of biofillers can, inter alia, increase the tensile strength of the composite, improve damping properties, extend the burning time of the material and affect the course of vulcanization or cross-linking density.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mayukh Nath ◽  
Shovan Maity ◽  
Shitij Avlani ◽  
Scott Weigand ◽  
Shreyas Sen

AbstractRadiative communication using electromagnetic fields is the backbone of today’s wirelessly connected world, which implies that the physical signals are available for malicious interceptors to snoop within a 5–10 m distance, also increasing interference and reducing channel capacity. Recently, Electro-quasistatic Human Body Communication (EQS-HBC) was demonstrated which utilizes the human body’s conductive properties to communicate without radiating the signals outside the body. Previous experiments showed that an attack with an antenna was unsuccessful at a distance more than 1 cm from the body surface and 15 cm from an EQS-HBC device. However, since this is a new communication modality, it calls for an investigation of new attack modalities—that can potentially exploit the physics utilized in EQS-HBC to break the system. In this study, we present a novel attack method for EQS-HBC devices, using the body of the attacker itself as a coupling surface and capacitive inter-body coupling between the user and the attacker. We develop theoretical understanding backed by experimental results for inter-body coupling, as a function of distance between the subjects. We utilize this newly developed understanding to design EQS-HBC transmitters that minimizes the attack distance through inter-body coupling, as well as the interference among multiple EQS-HBC users due to inter-body coupling. This understanding will allow us to develop more secure and robust EQS-HBC based body area networks in the future.


Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1431
Author(s):  
Ilkyu Kim ◽  
Sun-Gyu Lee ◽  
Yong-Hyun Nam ◽  
Jeong-Hae Lee

The development of biomedical devices benefits patients by offering real-time healthcare. In particular, pacemakers have gained a great deal of attention because they offer opportunities for monitoring the patient’s vitals and biological statics in real time. One of the important factors in realizing real-time body-centric sensing is to establish a robust wireless communication link among the medical devices. In this paper, radio transmission and the optimal characteristics for impedance matching the medical telemetry of an implant are investigated. For radio transmission, an integral coupling formula based on 3D vector far-field patterns was firstly applied to compute the antenna coupling between two antennas placed inside and outside of the body. The formula provides the capability for computing the antenna coupling in the near-field and far-field region. In order to include the effects of human implantation, the far-field pattern was characterized taking into account a sphere enclosing an antenna made of human tissue. Furthermore, the characteristics of impedance matching inside the human body were studied by means of inherent wave impedances of electrical and magnetic dipoles. Here, we demonstrate that the implantation of a magnetic dipole is advantageous because it provides similar impedance characteristics to those of the human body.


Nuncius ◽  
2011 ◽  
Vol 26 (1) ◽  
pp. 21-49
Author(s):  
Dario De Santis

AbstractThe scientific debate which developed during the eighteenth century, proposed and diffused new theories on the generation not only within the scientific community. Microscopic investigation and various experimental campaigns fostered daring models attempting to unveil the natural phenomena from which life originates. Besides the famous scientific and philosophical works that marked the age, in the second part of the century two pamphlets appeared that well represent the importance of the querelle about embryological systems defining the concept of generation as a voyage within the human body. Lucina sine concubitu and Juno abortans, respectively published in England and in Germany between 1750 and 1760, narrate the odd and imaginary adventures of two doctors who are trying to interrupt and modify the embryos' journey towards the body of the mother.


2015 ◽  
Vol 2015 ◽  
pp. 1-9
Author(s):  
Young-Doo Kwon ◽  
Seong-Hwa Jun ◽  
Ji-Min Song

Most machines and instruments constantly require elastomeric materials like rubber for the purposes of shock absorption, noise attenuation, and sealing. The material properties and accurate lifetime prediction of rubber are closely related to the quality of machines, especially their durability and reliability. The properties of rubber-like elastomers are influenced by ambient conditions, such as temperature, environment, and mechanical load. Moreover, the initial properties of rubber gaskets must be sustained under working conditions to satisfy their required function. Because of its technical merits, as well as its low cost, the highly accelerated life test (HALT) is used by many researchers to predict the long-term lifetime of rubber materials. Methyl vinyl silicone rubber (VMQ) has recently been adopted to improve the lifetime of automobile radiator gaskets. A four-parameter method of determining the recovery ability of the gaskets was recently published, and two revised methods of obtaining the recovery were proposed for polyacrylate (ACM) rubber. The recovery rate curves for VMQ were acquired using the successive zooming genetic algorithm (SZGA). The gasket lifetime for the target recovery (60%) of a compressed gasket was computed somewhat differently depending on the selected regression model.


Author(s):  
Katarzyna Zadka ◽  
Ewelina Pałkowska-Goździk ◽  
Danuta Rosołowska-Huszcz

The percentage of children with vitamin D deficiency in Poland is alarming. The aim of the study was to assess the knowledge about sources of food and the function of vitamin D, as well as the frequency of its supplementation. A survey was conducted among the parents of children from Central Poland attending primary schools, and a questionnaire containing mainly open-ended questions was used to collect the data. Most mothers knew at least one of the functions of vitamin D in the body but had a low level of knowledge about its dietary sources. Only a small group of respondents supplemented themselves and their children with vitamin D. Statistically significant influences on the level of knowledge about the functions and sources of vitamin D were place of residence (i.e., better knowledge in the countryside) and mothers’ level of education (i.e., the better educated, the greater knowledge). In the case of monthly income level, such impact was observed only in relation to the knowledge of vitamin D functions. Concerning the frequency of supplementation, only maternal level of education had a statistically significant effect (i.e., the higher the education level, the higher the frequency of supplementation). In addition, mothers who were aware of functions of vitamin D and nutritional sources, significantly more frequently supplemented vitamin D.


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