Explaining Outcome Differences between Men and Women following Mild Traumatic Brain Injury

Abstract

Research on soft artificial muscles (SAMs) is rapidly growing, both in developing new actuation ideas and improving existing structures with multifunctionality. The human body has more than 600 muscles that drive organs and joints to achieve desired functions. Inspired by the human muscles, this article presents a new type of SAM fiber formed from twisting and braiding soft hydraulic filament artificial muscles with high aspect ratio, high strain, and high energy efficiency. We systematically investigated the relationship between input pressure and output elongation as well as contraction force of the new muscles using different configurations in terms of an array of single and multiple muscles arranged in nontwisting (or straight), twisting, and braiding variants. Experimental results revealed that the twisting and braiding configurations greatly enhanced the muscle elongation and generated force compared with their nontwisting/braiding counterparts. To demonstrate the new muscles' usability, we implemented several muscle variants to bidirectionally manipulate 3D-printed human fingers and elbow, mimicking the human upper limb with a full range of motion. We also created a bioinspired growing soft tubular muscle that could simultaneously exert longitudinal and radial expansion upon pressurization, similar to that of auxetic metamaterial structures. The new growing soft tubular muscles were experimentally validated and the results showed that they could be potentially implemented in several emerging applications, including smart compression garments, stent-like supporting devices, and tubular grippers for medical use.

Optimization of a Translational Murine Model of Closed-head Traumatic Brain Injury

“…In a recent retrospective study of mild traumatic brain injury (TBI), females had a worse outcome than males 3, 4 . These sex related differences in outcome are not explained by sociodemographic or care pathways, and have yet to be identified 3, 5, 6 . Clinically relevant animal models of TBI can provide insight into the mechanisms that underlie the brain response to injury, factors contributing to pathological outcomes, and facilitate screening of therapeutics to improve functional recovery.…”

“…The worse outcome could not be explained by sociodemographic or care pathways, and have yet to be identified 3,5,6 . Animal models of TBI can provide insight into the mechanisms that underlie the brain response to injury, factors contributing to pathological outcomes, and facilitate screening of therapeutics to improve functional recovery.…”

“…Patients with TBI are stratified into mild (GCS[13][14][15], moderate (GCS 9-13) and severe(3)(4)(5)(6)(7)(8) injury based on the score. While relatively crude, this tool is predictive of outcome for moderate to severe injury patients[24][25][26] .…”

Persistent Hypersomnia Following Repetitive Mild Experimental Traumatic Brain Injury: Roles of Chronic Stress and Sex Differences

“…Complex experiences of repetitive mild TBI with environmental and/or emotional stressors are particularly relevant to military service members, who may experience events of head impact and/or acceleration, blast exposure, and stress due to traumatic experiences, adverse conditions and sleep deficiency. Natural history studies in military and civilian patients with TBI will continue to be important for understanding the heterogeneity of events, including stress and blast exposures, and patient factors such as age and sex/gender that influence symptom expression [2, 7, 8]. To complement these clinical studies in understanding factors contributing to TBI outcomes, specific components of the stress and mild TBI events can be modeled in animals.…”

“…The study design is for each component (environmental stressors, repetitive blast and mild brain injury, or isolation stress) to be mild so as not to independently produce significant symptoms but rather to result in persistent symptom expression when experienced in combination over a prolonged period of time. In studies of mild TBI, significant differences have been observed in outcomes between men and women [7, 8]. Therefore, sex was evaluated for the response to stress and head injury exposures.…”