Archive for month: August, 2020

Drawing heavily upon nature for inspiration, a team of researchers has created a new artificial lens that is nearly identical to the natural lens of the human eye. This innovative lens, which is made up of thousands of nanoscale polymer layers, may one day provide a more natural performance in implantable lenses to replace damaged or diseased human eye lenses, as well as consumer vision products; it also may lead to superior ground and aerial surveillance technology.
This work, which the Case Western Reserve University, Rose-Hulman Institute of Technology, U.S. Naval Research Laboratory, and PolymerPlus team also provides a new material approach for fabricating synthetic polymer lenses.
The fundamental technology behind this new lens is called ‘GRIN’ or gradient refractive index optics. In GRIN, light gets bent, or refracted, by varying degrees as it passes through a lens or other transparent material. This is in contrast to traditional lenses, like those found in optical telescopes and microscopes, which use their surface shape or single index of refraction to bend light one way or another.
‘The human eye is a GRIN lens,’ said Michael Ponting, polymer scientist and president of PolymerPlus, an Ohio-based Case Western Reserve spin-off launched in 2010. ‘As light passes from the front of the human eye lens to the back, light rays are refracted by varying degrees. It’s a very efficient means of controlling the pathway of light without relying on complicated optics, and one that we attempted to mimic.’
The first steps along this line were taken by other researchers and resulted in a lens design for an ageing human eye, but the technology did not exist to replicate the gradual evolution of refraction.
The research team’s new approach was to follow nature’s example and build a lens by stacking thousands and thousands of nanoscale layers, each with slightly different optical properties, to produce a lens that gradually varies its refractive index, which adjusts the refractive properties of the polymer.
‘Applying naturally occurring material architectures, similar to those found in the layers of butterfly wing scales, human tendons, and even in the human eye, to multi-layered plastic systems has enabled discoveries and products with enhanced mechanical strength, novel reflective properties, and optics with enhanced power,’ explains Ponting.
To make the layers for the lens, the team used a multi-layer-film co-extrusion technique (a common method used to produce multi-layer structures). This fabrication technique allows each layer to have a unique refractive index that can then be laminated and shaped into GRIN optics.
It also provides the freedom to stack any combination of the unique refractive index nanolayered films. This is extremely significant and enabled the fabrication of GRIN optics previously unattainable through other fabrication techniques.
GRIN optics may find use in miniaturised medical imaging devices or implantable lenses. ‘A copy of the human eye lens is a first step toward demonstrating the capabilities, eventual biocompatible and possibly deformable material systems necessary to improve the current technology used in optical implants,’ Ponting says. EurekAlert

The World Health Organization has launched the first global strategy on health policy and systems research (HPSR) at the Second Global Symposium on Health Systems Research. This document represents a unique milestone in the evolution of health policy and systems research and has three broad aims. First, it seeks to unify the worlds of research and decision-making and connect the various disciplines of research that generate knowledge to inform and strengthen health systems. Second, the strategy contributes to a broader understanding of this field by clarifying the scope and role of HPSR. It provides insight into the dynamic processes through which HPSR evidence is generated and used in decision-making. Finally, it is hoped that this strategy will serve as an agent for change and calls for a more prominent role for HPSR at a time when the health systems mandate is evolving towards broader goals of universal health coverage and equity. This strategy on health policy and systems research is intended to augment and amplify WHO

Psychological factors can have as much-or more-impact on pediatric chest pain as physical ones, a University of Georgia study found recently. UGA psychologists discovered pediatric patients diagnosed with non-cardiac chest pain have higher levels of anxiety and depression than patients diagnosed with innocent heart murmurs-the noise of normal turbulent blood flow in a structurally normal heart.
The UGA research was done in collaboration with Children’s Healthcare of Atlanta and Emory University.
‘The fact that these psychological symptoms are higher in non-cardiac chest pain patients suggests the psychological symptoms may be playing a role in the presentation of chest pain,’ said Jennifer Lee, a doctoral candidate in the UGA Franklin College of Arts and Sciences and the study’s lead author.
The results of the study show a statistically significant increase in anxiety and depression among patients who are later diagnosed with non-cardiac chest pain when compared to patients diagnosed with innocent heart murmurs. Lee said it is not clear if the anxiety is a cause of the pain or if pain caused the anxiety in the sample group.
‘The higher levels weren’t so high as to cause a clinical diagnosis on their own, but when you contrast the two groups, there were statistically significant differences,’ said study co-author Ronald Blount, a psychology professor in the Franklin College.
The study included 129 patients ages 8 to 18. The group completed surveys prior to diagnosis. All patients were essentially in the same situation-sitting in a cardiology office awaiting their unknown medical diagnosis.
‘We are highlighting that psychology has a part in these symptoms,’ Blount said, ‘and screening for psychological, as well as medical factors, is one implication we foresee coming from this investigation.’
Chest pain can indicate serious medical conditions that require a doctor’s evaluation. In adults, pain in the chest is often linked to a cardiac problem. In children, however, less than 2 percent of patients receive a cardiac diagnosis for their pain.
The Sibley Heart Center at Children’s Healthcare of Atlanta is one of the largest pediatric heart centres in the world, seeing an average of 2,500 new patients with acute chest pain each year.
‘We know up front that 99 percent of these patients will not have a heart complication at all. The trick is, it is not zero, and I cannot miss the one patient with heart disease because the consequences could be catastrophic,’ said Dr. Robert Campbell, chief of the Sibley Heart Center and division director of the department of pediatrics at the Emory University School of Medicine.
The study also observed that non-cardiac chest pain patients have a higher level of functional disability-or the inability to participate in everyday activities like running across a football field or making it through a day without a nap. They also spent less time at school and were less involved in extra-curricular activities.
‘These kids also report greater levels of physical symptoms with unclear causes, like joint pain, stomach aches, head aches,’ Lee said. ‘These symptoms are believed to be psychological manifestations of stress. Sometimes your brain doesn’t tell you that you are stressed out, but your body does, so you will experience symptoms like these.’
Pediatric patients with non-cardiac chest pain also reported higher levels of anxiety sensitivity, a fear of experiencing physical symptoms and additionally fearing that those symptoms are related to a catastrophic health issue.
‘Psychological functioning is heavily related to pain,’ Blount said. ‘Pain is a sensory experience, but your attention to one thing or another and your emotions can impact your experience of pain. And how debilitating the pain is for you can be determined by psychological and social factors. That is what we were interested in looking at.’
Previous studies have shown reducing emotional symptoms can lead to better coping ability with pain, Lee said. ‘A goal with these patients would be to create a clearer, more comprehensive picture of what is going on and determine a better way to help these kids and adolescents.’
Campbell said the UGA research helps him serve the majority of his patients who leave his office with a clean bill of health but unexplained chest pain.
‘Most importantly what we’ve learned is that after a physical evaluation of the patient, we take the time to sit down with the family and find out what they are most worried about so we can address their psychological issues,’ Campbell said. ‘We’ve learned to pay attention and to be confident and reassuring. I need to make it clear to my patients and their parents that I’m not saying you are not having pain, but that the pain is not caused by your heart.’ University of Georgia

The father acts as an intermediary for dentist fear between both mother and children
Fear of visiting the dentist is a frequent problem in paediatric dentistry. A new study confirms the emotional transmission of dentist fear among family members and analyses the different roles that mothers and fathers might play.
A new study conducted by scientists at the Rey Juan Carlos University of Madrid highlights the important role that parents play in the transmission of dentist fear in their family.
Previous studies had already identified the association between the fear levels of parents and their children, but they never explored the different roles that the father and the mother play in this phenomenon.
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