scholarly journals Corneal Biomechanical Properties in Different Ocular Conditions and New Measurement Techniques

2014 ◽  
Vol 2014 ◽  
pp. 1-19 ◽  
Author(s):  
Nery Garcia-Porta ◽  
Paulo Fernandes ◽  
Antonio Queiros ◽  
Jose Salgado-Borges ◽  
Manuel Parafita-Mato ◽  
...  
Keyword(s):  
New Technologies ◽  
Measurement Techniques ◽  
Biomechanical Properties ◽  
The Body ◽  
Mechanical Resistance ◽  
Fundamental Properties ◽  
Visual Science ◽  
Clinical Tools ◽  
Corneal Biomechanical Properties

Several refractive and therapeutic treatments as well as several ocular or systemic diseases might induce changes in the mechanical resistance of the cornea. Furthermore, intraocular pressure measurement, one of the most used clinical tools, is also highly dependent on this characteristic. Corneal biomechanical properties can be measured now in the clinical setting with different instruments. In the present work, we review the potential role of the biomechanical properties of the cornea in different fields of ophthalmology and visual science in light of the definitions of the fundamental properties of matter and the results obtained from the different instruments available. The body of literature published so far provides an insight into how the corneal mechanical properties change in different sight-threatening ocular conditions and after different surgical procedures. The future in this field is very promising with several new technologies being applied to the analysis of the corneal biomechanical properties.

Living with Barren Truths: A Tale of Triumphalism and Tribulations of a Technology

2021 ◽  
pp. 097168582110159
Author(s):  
Sital Mohanty ◽  
Subhasis Sahoo ◽  
Pranay Kumar Swain
Keyword(s):  
Gender Discrimination ◽  
New Technologies ◽  
The Body ◽  
Social Scientists ◽  
Social Fact ◽  
Science Technology ◽  
The Subject ◽  
And Gender ◽  
The Relationship

Science, technology and human values have been the subject of enquiry in the last few years for social scientists and eventually the relationship between science and gender is the subject of an ongoing debate. This is due to the event of globalization which led to the exponential growth of new technologies like assisted reproductive technology (ART). ART, one of the most iconic technological innovations of the twentieth century, has become increasingly a normal social fact of life. Since ART invades multiple human discourses—thereby transforming culture, society and politics—it is important what is sociological about ART as well as what is biological. This article argues in commendation of sociology of technology, which is alert to its democratic potential but does not concurrently conceal the historical and continuing role of technology in legitimizing gender discrimination. The article draws the empirical insights from local articulations (i.e., Odisha state in eastern India) for the understandings of motherhood, freedom and choice, reproductive right and rights over the body to which ART has contributed. Sociologically, the article has been supplemented within the broader perspectives of determinism, compatibilism alongside feminism.

scholarly journals Role of corneal biomechanical properties in predicting of speed of myopic progression in children wearing orthokeratology lenses or single-vision spectacles

2018 ◽  
Vol 3 (1) ◽  
pp. e000204 ◽  
Author(s):  
Kin Wan ◽  
Sin Wan Cheung ◽  
James S Wolffsohn ◽  
Janis B Orr ◽  
Pauline Cho
Keyword(s):  
Axial Length ◽  
Corneal Thickness ◽  
Significant Negative Correlation ◽  
Biomechanical Properties ◽  
Corneal Hysteresis ◽  
Axial Elongation ◽  
Single Vision ◽  
Length Data ◽  
Corneal Biomechanical Properties

ObjectiveTo determine the characteristics of children who were likely to progress rapidly and gain the greatest benefit from orthokeratology (ortho-k) treatment.Methods and analysisThe files of 113 children who participated in two myopia control studies and wore either ortho-k lenses (n=62) or single-vision spectacles (SVS) (n=51) were reviewed. Baseline cycloplegic subjective refraction, central corneal thickness, axial length, keratometry, intraocular pressure, corneal biomechanical properties and 24-month axial length data were retrieved and analysed.ResultsMultivariate analysis showed that there was significant negative correlation between axial elongation and baseline age and corneal hysteresis (p<0.05) in the SVS group. In the ortho-k group, only baseline age was significantly and negatively associated with axial elongation (p<0.01).ConclusionCorneal biomechanical properties and baseline age can predict the rate of axial elongation in myopic children. It may be beneficial for younger myopic children with low corneal hysteresis to commence ortho-k treatment as early as possible.

scholarly journals Molecular Politics, Wearables, and the Aretaic Shift in Biopolitical Governance

2020 ◽  
Vol 37 (3) ◽  
pp. 71-96
Author(s):  
Peter Lindner
Keyword(s):  
Human Body ◽  
Common Ground ◽  
New Technologies ◽  
Expert Knowledge ◽  
The Body ◽  
Life Itself ◽  
The Common ◽  
The Individual ◽  
Individual Body

Since the publication of Nikolas Rose’s ‘The Politics of Life Itself’ (2001) there has been vivid discussion about how biopolitical governance has changed over the last decades. This article uses what Rose terms ‘molecular politics’, a new socio-technical grip on the human body, as a contrasting background to ask anew his question ‘What, then, of biopolitics today?’ – albeit focusing not on advances in genetics, microbiology, and pharmaceutics, as he does, but on the rapid proliferation of wearables and other sensor-software gadgets. In both cases, new technologies providing information about the individual body are the common ground for governance and optimization, yet for the latter, the target is habits of moving, eating and drinking, sleeping, working and relaxing. The resulting profound differences are carved out along four lines: ‘somatic identities’ and a modified understanding of the body; the role of ‘expert knowledge’ compared to that of networks of peers and self-experimentation; the ‘types of intervention’ by which new technologies become effective in our everyday life; and the ‘post-discipline character’ of molecular biopolitics. It is argued that, taken together, these differences indicate a remarkable shift which could be termed aretaic: its focus is not ‘life itself’ but ‘life as it is lived’, and its modality are new everyday socio-technical entanglements and their more-than-human rationalities of (self-)governance.

scholarly journals Corneocytes: Relationship between Structural and Biomechanical Properties

2021 ◽  
pp. 1-16
Author(s):  
Ana S. Évora ◽  
Michael J. Adams ◽  
Simon A. Johnson ◽  
Zhibing Zhang
Keyword(s):  
Surface Area ◽  
Barrier Function ◽  
Biomechanical Properties ◽  
The Body ◽  
Mechanical Resistance ◽  
Cornified Envelope ◽  
Skin Cells ◽  
Exposed Skin ◽  
Immature Cells ◽  
The Relationship

<b><i>Background:</i></b> Skin is the interface between an organism and the external environment, and hence the stratum corneum (SC) is the first to withstand mechanical insults that, in certain conditions, may lead to integrity loss and the development of pressure ulcers. The SC comprises corneocytes, which are vital elements to its barrier function. These cells are differentiated dead keratinocytes, without organelles, composed of a cornified envelope and a keratin-filled interior, and connected by corneodesmosomes (CDs). <b><i>Summary:</i></b> The current review focusses on the relationship between the morphological, structural, and topographical features of corneocytes and their mechanical properties, to understand how they assist the SC in maintaining skin integrity and in responding to mechanical insults. <b><i>Key Messages:</i></b> Corneocytes create distinct regions in the SC: the inner SC is characterized by immature cells with a fragile cornified envelope and a uniform distribution of CDs; the upper SC has resilient cornified envelopes and a honeycomb distribution of CDs, with a greater surface area and a smaller thickness than cells from the inner layer. The literature indicates that this upward maturation process is one of the most important steps in the mechanical resistance and barrier function of the SC. The morphology of these cells is dependent on the body site: the surface area in non-exposed skin is about 1,000–1,200 μm<sup>2</sup>, while for exposed skin, for example, the cheek and forehead, is about 700–800 μm<sup>2</sup>. Corneocytes are stiff cells compared to other cellular types, for example, the Young’s modulus of muscle and fibroblast cells is typically a few kPa, while that of corneocytes is reported to be about hundreds of MPa. Moreover, these skin cells have 2 distinct mechanical regions: the cornified envelope (100–250 MPa) and the keratin matrix (250–500 MPa).

scholarly journals Levels of lactoferrin, lysozyme and albumin in the tear film of keratoconus patients and their correlations with important parameters of the disease

2020 ◽  
Vol 28 (2) ◽  
pp. 153-161
Author(s):  
Miruna Gabriela Burcel ◽  
Mihaela Constantin ◽  
Gabriela Ionita ◽  
Dana Dascalescu ◽  
Catalina Ionescu ◽  
...  
Keyword(s):  
Prospective Study ◽  
Tear Film ◽  
Protein Composition ◽  
Normal Subjects ◽  
Biomechanical Properties ◽  
Inflammatory Factors ◽  
Enzyme Linked Immunosorbent Assay ◽  
Ophthalmological Examination ◽  
Corneal Biomechanical Properties

AbstractBackground: Despite the fact that keratoconus has been tipically defined as a noninflammatory condition, recent research has promoted the role of inflammatory factors and protein changes of tear film in disease progression.Aims: to determine the level of serum albumin, lactoferrin and lyzozyme in tears of keratoconic patients and their correlations with corneal biomechanical properties.Subjects and methods: 16 eyes of keratoconus patients and 14 eyes of control cases were enrolled in an observational prospective study. We performed a complete ophthalmological examination on all participants. In order to determine the concentration of tear film proteins, a minimum of 20 microlitres of tears from the lower conjunctival fornix were collected from each subject and measured by enzyme-linked immunosorbent assay (ELISA) analysis.Results: The level of lactoferrin measured in the tear film was significantly decreased in the keratoconus group compared to the normal subjects in all cases (p<0.05). We also found an increased level of lyzozyme and albumin in the keratoconus patients when compared to the controls, only the lyzozyme beeing statistically significant. In the keratoconus group, the correlations between proteins and important parameters such as keratometry, pachymetry and corneal biomechanics were statistically relevant in our study.Conclusions: We can state that the protein composition of tears is modified in keratoconus by increased levels of protein with inflammatory properties such as albumin or by decreased levels of protein with anti-inflammatory properties such as lactoferrin.

scholarly journals Losing Touch: An Embodiment Perspective on Coordination in Robotic Surgery

2020 ◽  
Vol 31 (5) ◽  
pp. 1248-1271 ◽  
Author(s):  
Anastasia V. Sergeeva ◽  
Samer Faraj ◽  
Marleen Huysman
Keyword(s):  
New Technologies ◽  
Da Vinci ◽  
New Technology ◽  
The Body ◽  
Da Vinci Robot ◽  
Joint Task ◽  
Knowledge Emergence ◽  
And Shifts ◽  
Embodied Action

Because new technologies allow new performances, mediations, representations, and information flows, they are often associated with changes in how coordination is achieved. Current coordination research emphasizes its situated and emergent nature, but seldom accounts for the role of embodied action. Building on a 25-month field study of the da Vinci robot, an endoscopic system for minimally invasive surgery, we bring to the fore the role of the body in how coordination was reconfigured in response to a change in technological mediation. Using the robot, surgeons experienced both an augmentation and a reduction of what they can do with their bodies in terms of haptic, visual, and auditory perception and manipulative dexterity. These bodily augmentations and reductions affected joint task performance and led to coordinative adaptations (e.g., spatial relocating, redistributing tasks, accommodating novel perceptual dependencies, and mounting novel responses) that, over time, resulted in reconfiguration of roles, including expanded occupational knowledge, emergence of new specializations, and shifts in status and boundaries. By emphasizing the importance of the body in coordination, this paper suggests that an embodiment perspective is important for explaining how and why coordination evolves following the introduction of a new technology.

Role of Corneal Biomechanical Properties in Applanation Tonometry Measurements

2009 ◽  
Vol 26 (7) ◽  
pp. 512-519 ◽  
Author(s):  
Tae-Hyun Kwon ◽  
Jamshid Ghaboussi ◽  
David A. Pecknold ◽  
Youssef M.A. Hashash
Keyword(s):  
Biomechanical Properties ◽  
Applanation Tonometry ◽  
Corneal Biomechanical Properties

Meiotic CENP-C is a shepherd: bridging the space between the centromere and the kinetochore in time and space

2020 ◽  
Vol 64 (2) ◽  
pp. 251-261
Author(s):  
Jessica E. Fellmeth ◽  
Kim S. McKim
Keyword(s):  
Chromosome Segregation ◽  
New Technologies ◽  
Early Prophase ◽  
Unique Role ◽  
Kinetochore Assembly ◽  
M Phase ◽  
In Vivo Analysis ◽  
Meiosis I

Abstract While many of the proteins involved in the mitotic centromere and kinetochore are conserved in meiosis, they often gain a novel function due to the unique needs of homolog segregation during meiosis I (MI). CENP-C is a critical component of the centromere for kinetochore assembly in mitosis. Recent work, however, has highlighted the unique features of meiotic CENP-C. Centromere establishment and stability require CENP-C loading at the centromere for CENP-A function. Pre-meiotic loading of proteins necessary for homolog recombination as well as cohesion also rely on CENP-C, as do the main scaffolding components of the kinetochore. Much of this work relies on new technologies that enable in vivo analysis of meiosis like never before. Here, we strive to highlight the unique role of this highly conserved centromere protein that loads on to centromeres prior to M-phase onset, but continues to perform critical functions through chromosome segregation. CENP-C is not merely a structural link between the centromere and the kinetochore, but also a functional one joining the processes of early prophase homolog synapsis to late metaphase kinetochore assembly and signaling.

The Role of Polyphenols in the Modulation of Plasma Non-Enzymatic Antioxidant Capacity (NEAC)

2012 ◽  
Vol 82 (3) ◽  
pp. 228-232 ◽  
Author(s):  
Mauro Serafini ◽  
Giuseppa Morabito
Keyword(s):  
Antioxidant Capacity ◽  
Dietary Intervention ◽  
Ex Vivo ◽  
The Body ◽  
Dietary Polyphenols ◽  
Enzymatic Antioxidant ◽  
Endogenous Antioxidant

Dietary polyphenols have been shown to scavenge free radicals, modulating cellular redox transcription factors in different in vitro and ex vivo models. Dietary intervention studies have shown that consumption of plant foods modulates plasma Non-Enzymatic Antioxidant Capacity (NEAC), a biomarker of the endogenous antioxidant network, in human subjects. However, the identification of the molecules responsible for this effect are yet to be obtained and evidences of an antioxidant in vivo action of polyphenols are conflicting. There is a clear discrepancy between polyphenols (PP) concentration in body fluids and the extent of increase of plasma NEAC. The low degree of absorption and the extensive metabolism of PP within the body have raised questions about their contribution to the endogenous antioxidant network. This work will discuss the role of polyphenols from galenic preparation, food extracts, and selected dietary sources as modulators of plasma NEAC in humans.

The Role of Computer Modeling in Electrocardiography

1990 ◽  
Vol 29 (04) ◽  
pp. 282-288 ◽  
Author(s):  
A. van Oosterom
Keyword(s):  
Electrical Activity ◽  
Computer Modeling ◽  
Body Surface ◽  
Electrical Current ◽  
The Body ◽  
Volume Conductor ◽  
Current Generator ◽  
Cardiac Electrical Activity ◽  
Source Models

AbstractThis paper introduces some levels at which the computer has been incorporated in the research into the basis of electrocardiography. The emphasis lies on the modeling of the heart as an electrical current generator and of the properties of the body as a volume conductor, both playing a major role in the shaping of the electrocardiographic waveforms recorded at the body surface. It is claimed that the Forward-Problem of electrocardiography is no longer a problem. Several source models of cardiac electrical activity are considered, one of which can be directly interpreted in terms of the underlying electrophysiology (the depolarization sequence of the ventricles). The importance of using tailored rather than textbook geometry in inverse procedures is stressed.

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