Rheological Properties of Anisotropic Tissues at Large Amplitude Oscillatory Shear

2012 ◽  
Author(s):  
Kristy Tan ◽  
Shaokoon Cheng ◽  
Lynne E. Bilston
Keyword(s):  
Mechanical Properties ◽  
Load Transfer ◽  
Biological Tissues ◽  
The Body ◽  
Accurate Information ◽  
Soft Biological Tissues ◽  
The Past ◽  
Crash Testing ◽  
Car Crash ◽  
The Brain

The mechanical properties of soft biological tissues have been widely investigated over the past five decades [1–5]. Reported measurements of soft biological tissues such as the brain, spinal cord, liver and muscle vary by orders of magnitude, depending on the sample preparation, anisotropy and loading regime. Knowing the accurate mechanical properties of biological tissues is important for many applications, for example car crash testing and simulations require accurate information on how different parts of the body deform due to a combination of loads. Deformation of tissues around prosthetics and artificial limbs are critical in understanding load transfer at interfaces with the body. The recent use of Magnetic Resonance Elastography (MRE) in diagnostic imaging has resulted in a surge of interest in accurate measurements of mechanical properties of tissues [6].

scholarly journals Численное моделирование миграции фотонов в однородных и неоднородных цилиндрических фантомах

2020 ◽  
Vol 128 (6) ◽  
pp. 832
Author(s):  
А.Ю. Потлов ◽  
С.В. Фролов ◽  
С.Г. Проскурин
Keyword(s):  
Radiation Transfer ◽  
Biological Tissues ◽  
Photon Density ◽  
Radiation Transfer Equation ◽  
Scattering Media ◽  
Soft Biological Tissues ◽  
Photon Diffusion ◽  
Low Coherence ◽  
The Brain ◽  
Pulsed Irradiation

The specific features of photon diffusion of low-coherence pulsed irradiation in phantoms of soft biological tissues (blood-saturated tissues of the brain, breast, etc.) are described. The results of photon migration simulation using the Diffusion Approximation to the Radiation Transfer Equation (RTE) are compared with ones of the Monte Carlo simulations. It has been confirmed that the Photon Density Normalized Maximum (PDNM) moves towards the center of the investigated object in case of relatively uniform and strongly scattering media. In the presence of inhomogeneities, type of the PDNM motion changes drastically. Presence of an absorbing inhomogeneity in the medium directs trajectory of the PDNM motion of towards the point symmetric to the inhomogeneity relative to the geometric center of the investigated object. In case of scattering the PDNM moves toward the direction of the center of the scattering inhomogeneity.

Corticotrophin Releasing Hormone: Chemistry and Recent Developments

2004 ◽  
Vol 57 (5) ◽  
pp. 393 ◽  
Author(s):  
James Garner ◽  
Paul A. Keller ◽  
Adam McCluskey
Keyword(s):  
Neurological Disorders ◽  
Biological Clock ◽  
The Body ◽  
Exciting Field ◽  
Releasing Hormone ◽  
The Past ◽  
Corticotrophin Releasing Factor ◽  
Recent Developments ◽  
Fight Or Flight Response ◽  
The Brain

Corticotrophin Releasing Hormone [CRH; also known as Corticotrophin Releasing Factor (CRF)], a 41-amino-acid hormone, is one of the body’ major modulators of the stress response. CRH coordinates the endocrine, autonomic, and behavioural responses to stress through actions in both the brain and the periphery activating the ‘fight or flight’ response. CRH is also implicated in various neurological disorders including Alzheimer’s, Parkinson’s, and anorexia nervosa, and it has been described as a biological clock controlling the length of gestation in humans and other higher-order primates. In the past decade there has been an enormous effort expended in the design and development of new therapeutic agents targetting CRHs in the central nervous and peripheral systems. In this review, we examine the chemistry and recent developments in this exciting field.

scholarly journals A Survey in Implementation and Applications of Electroencephalograph (EEG)-Based Brain-Computer Interface

2021 ◽  
Vol 39 (7) ◽  
pp. 1117-1132
Author(s):  
Samaa S. Abdulwahab ◽  
Hussain K. Khleaf ◽  
Manal H. Jassim
Keyword(s):  
Brain Computer Interface ◽  
Physical World ◽  
The Body ◽  
Computer Interface ◽  
Signal Acquisition ◽  
Rule Based ◽  
The Past ◽  
Brain Signals ◽  
Translation Systems ◽  
The Brain

A Brain-Computer Interface (BCI) is an external system that controls activities and processes in the physical world based on brain signals. In Passive BCI, artificial signals are automatically generated by a computer program without any input from nerves in the body. This is useful for individuals with mobility issues. Traditional BCI has been dependent only on recording brain signals with Electroencephalograph (EEG) and has used a rule-based translation algorithm to generate control commands. These systems have developed very accurate translation systems. This paper is about the different methods for adapting the signals from the brain. It has been mentioned that various kinds of surveys in the past to serve the purpose of the present research. This paper shows a simple and easy analysis of each technique and its respective benefits and drawbacks, including signal acquisition, signal pre-processing, feature classification and classification. Finally,  discussed is the application of EEG-based BCI.

scholarly journals The ACE2/Angiotensin-(1–7)/MAS Axis of the Renin-Angiotensin System: Focus on Angiotensin-(1–7)

2018 ◽  
Vol 98 (1) ◽  
pp. 505-553 ◽  
Author(s):  
Robson Augusto Souza Santos ◽  
Walkyria Oliveira Sampaio ◽  
Andreia C. Alzamora ◽  
Daisy Motta-Santos ◽  
Natalia Alenina ◽  
...  
Keyword(s):  
Current Knowledge ◽  
Renin Angiotensin System ◽  
The Body ◽  
Biologically Active ◽  
Ang Ii ◽  
Angiotensin System ◽  
Renin Angiotensin ◽  
The Past ◽  
The Brain ◽  
System Focus

The renin-angiotensin system (RAS) is a key player in the control of the cardiovascular system and hydroelectrolyte balance, with an influence on organs and functions throughout the body. The classical view of this system saw it as a sequence of many enzymatic steps that culminate in the production of a single biologically active metabolite, the octapeptide angiotensin (ANG) II, by the angiotensin converting enzyme (ACE). The past two decades have revealed new functions for some of the intermediate products, beyond their roles as substrates along the classical route. They may be processed in alternative ways by enzymes such as the ACE homolog ACE2. One effect is to establish a second axis through ACE2/ANG-(1–7)/MAS, whose end point is the metabolite ANG-(1–7). ACE2 and other enzymes can form ANG-(1–7) directly or indirectly from either the decapeptide ANG I or from ANG II. In many cases, this second axis appears to counteract or modulate the effects of the classical axis. ANG-(1–7) itself acts on the receptor MAS to influence a range of mechanisms in the heart, kidney, brain, and other tissues. This review highlights the current knowledge about the roles of ANG-(1–7) in physiology and disease, with particular emphasis on the brain.

scholarly journals Embodied Interaction and Spatial Skills: A Systematic Review of Empirical Studies

2020 ◽  
Author(s):  
Serena Lee-Cultura ◽  
Michail Giannakos
Keyword(s):  
Systematic Review ◽  
Empirical Studies ◽  
The Body ◽  
Human Interaction ◽  
Embodied Interaction ◽  
Spatial Skills ◽  
Successful Management ◽  
The Past ◽  
Future Work ◽  
The Brain

Abstract Embodied interaction describes the interplay between the brain and the body and its influence on the sharing, creation and manipulation of meaningful interactions with technology. Spatial skills entail the acquisition, organization, utilization and revision of knowledge about spatial environments. Embodied interaction is a rapidly growing topic in human–computer interaction with the potential to amplify human interaction and communication capacities, while spatial skills are regarded as key enablers for the successful management of cognitive tasks. This work provides a systematic review of empirical studies focused on embodied interaction and spatial skills. Thirty-six peer-reviewed articles were systematically collected and analysed according to their main elements. The results summarize and distil the developments concerning embodied interaction and spatial skills over the past decade. We identify embodied interaction capacities found in the literature review that help us to enhance and develop spatial skills. Lastly, we discuss implications for research and practice and highlight directions for future work.

scholarly journals Predictive constitutive modelling of arteries by deep learning

2021 ◽  
Vol 18 (182) ◽  
pp. 20210411
Author(s):  
Gerhard A. Holzapfel ◽  
Kevin Linka ◽  
Selda Sherifova ◽  
Christian J. Cyron
Keyword(s):  
Mechanical Properties ◽  
Deep Learning ◽  
Second Harmonic ◽  
Biological Tissues ◽  
Constitutive Modelling ◽  
Coefficient Of Determination ◽  
Soft Biological Tissues ◽  
Tissue Samples ◽  
Hybrid Modelling ◽  
Modelling Framework

The constitutive modelling of soft biological tissues has rapidly gained attention over the last 20 years. Current constitutive models can describe the mechanical properties of arterial tissue. Predicting these properties from microstructural information, however, remains an elusive goal. To address this challenge, we are introducing a novel hybrid modelling framework that combines advanced theoretical concepts with deep learning. It uses data from mechanical tests, histological analysis and images from second-harmonic generation. In this first proof of concept study, our hybrid modelling framework is trained with data from 27 tissue samples only. Even such a small amount of data is sufficient to be able to predict the stress–stretch curves of tissue samples with a median coefficient of determination of R 2 = 0.97 from microstructural information, as long as one limits the scope to tissue samples whose mechanical properties remain in the range commonly encountered. This finding suggests that deep learning could have a transformative impact on the way we model the constitutive properties of soft biological tissues.

Structurally Motivated Models of the Arterial Wall Tissue

2013 ◽  
Vol 05 (04) ◽  
pp. 1330002 ◽  
Author(s):  
Hadi Taghizadeh ◽  
Mohammad Tafazzoli Shadpour
Keyword(s):  
Mechanical Properties ◽  
Blood Pressure ◽  
Arterial Wall ◽  
Mechanical Characteristics ◽  
Biological Tissues ◽  
Soft Biological Tissues ◽  
Mechanical Environment ◽  
Highly Sensitive ◽  
Mechanical Models ◽  
Mechanical Factors

Mechanical characteristics of soft biological tissues mostly depend on their hierarchy at different scales from nano- to macro-structure. It is shown that arterial wall tissue is highly sensitive to its mechanical environment and any alteration in mechanical factors such as blood pressure, triggers physio- pathological processes within arterial wall. Quantification of these mechanical properties will provide us with deeper insights of ongoing biological events. In this context, mechanical contributions of wall constituents in health and diseases are of growing interest. Hence, this review is concerned with mechanical models of arterial wall tissue with a focus on microstructurally motivated representations.

scholarly journals Cullen, a Cautionary Tale

2015 ◽  
Vol 59 (2) ◽  
pp. 222-240 ◽  
Author(s):  
Sean Dyde
Keyword(s):  
The Body ◽  
Cautionary Tale ◽  
The Past ◽  
Original Meaning ◽  
Practice Of Medicine ◽  
Big Ideas ◽  
History Of ◽  
William Cullen ◽  
The Brain ◽  
Silver Bullet

AbstractSome ideas return after the briefest of exiles: reductionism is back in vogue. Existential questions – about who we are, about our origins and future, about what is valuable – no longer require difficult soul searching, especially when straightforward answers are expected from the neurosciences. History is being rewritten with the brain as its centrepiece; the search for great men and big ideas of the past begins again. William Cullen (1710–90), whose work on neurosis was once part of the history of psychoanalysis, is now well placed to become part of such a neuro-history. This article attempts to subvert this process, by rebuilding the original meaning of neurosis through Cullen’s physiological and medical works, in comparison with his predecessor, Robert Whytt (1714–66), and illustrating this meaning using one particular neurosis: hypochondriasis. The result is a more complicated version of neurosis which, importantly, carries significant insights into the nature and practice of medicine. Moreover, this article examines how Cullen’s standing fell in the 1820s as British physicians and surgeons turned to an idea which promised to reform medicine: pathological anatomy. When these hopes faded, Cullen became a figure obsessed with the nerves. This image has survived to the present, a blank canvas onto which any theory can be projected. It also values precisely what Cullen warned against: simplistic explanations of the body and disease, and unthinking confidence in the next big idea or silver bullet. Neurosis was not simply a nervous ailment, but it is a warning against reductionism in history making.

scholarly journals A compressive survey on different image processing techniques to identify the brain tumor

2018 ◽  
Vol 7 (2.7) ◽  
pp. 1081 ◽  
Author(s):  
K Bhagavan ◽  
Dr S. Sagar Imambi ◽  
Dr Shahana Bano
Keyword(s):  
The Body ◽  
Ct Scanner ◽  
Internal Organs ◽  
X Ray ◽  
The Past ◽  
After Effect ◽  
Magnetic Resonance Imaging Mri ◽  
Processing Techniques ◽  
The Brain ◽  
Improve Patient

Medical imaging technology has revolutionized health care over the past three decades allowing doctors to detect, cure and improve patient outcomes. Medicinal imaging makes picture of the internal organs, parts, tissues and bones for therapeutic examination and research pur-poses. It can likewise be utilized to think about elements of a few organs. X-ray and CT scanner are the two greatest after-effect of headway of imaging methods supplanting 2D procedures. X-ray is the standout amongst the most critical pre-processing ventures in tumor discovery. Magnetic resonance imaging (MRI) is really an imaging procedure in the restorative field. It is utilized as a part of radiology for imagining interior structures of the body and furthermore how they work. X-ray gives you the 3D picture of the inside bits of the body which enables the specialist to dissect the infection or tumor effortlessly though old imaging procedures like x-beam imaging gives you 2D pictures. In this paper we are introducing distinctive systems for distinguishing, preparing restorative pictures. 

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