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https://www.readbyqxmd.com/read/28329435/face-shield-design-against-blast-induced-head-injuries
#1
Long Bin Tan, Kwong Ming Tse, Yuan Hong Tan, Mohamad Ali Bin Sapingi, Vincent Beng Chye Tan, Heow Pueh Lee
Blast-induced traumatic brain injury (TBI) has been on the rise in recent years due to the increasing use of improvised explosive devices (IEDs) in conflict zones. Our study investigates the response of a helmeted human head subjected to a blast of 1 atm peak overpressure, for cases with and without a standard polycarbonate (PC) face shield and for face shields comprising of composite PC and aerogel materials and with lateral edge extension. The novel introduction of aerogel into the laminate face shield is explored and its wave-structure interaction mechanics and performance in blast mitigation is analysed...
March 22, 2017: International Journal for Numerical Methods in Biomedical Engineering
https://www.readbyqxmd.com/read/28290006/exercise-testing-and-stress-imaging-in-mitral-valve-disease
#2
REVIEW
Damien Voilliot, Patrizio Lancellotti
Mitral valve disease represented by mitral stenosis and mitral regurgitation is the second most frequent valvulopathy. Mitral stenosis leads to an increased left atrial pressure whereas mitral regurgitation leads to an increased left atrial pressure associated with a volume overload. Secondary to an upstream transmission of this overpressure, both mitral stenosis and regurgitation lead to pulmonary hypertension and right heart failure. In addition, mitral regurgitation also leads to left ventricular dilatation and dysfunction with left heart failure...
March 2017: Current Treatment Options in Cardiovascular Medicine
https://www.readbyqxmd.com/read/28289914/firecracker-eye-exposure-experimental-study-and-simulation
#3
Chiara Clemente, Luca Esposito, Domenico Speranza, Nicola Bonora
Understanding the mechanisms of traumatic ocular injury is helpful to make accurate diagnoses before the symptoms emerge and to develop specific eye protection. The comprehension of the dynamics of primary blast injury mechanisms is a challenging issue. The question is whether the pressure wave propagation and reflection alone could cause ocular damage. To date, there are dissenting opinions and no conclusive evidence thereupon. A previous numerical investigation of blast trauma highlighted the dynamic effect of pressure propagation and its amplification by the geometry of the bony orbit, inducing a resonance cavity effect and a standing wave hazardous for eye tissues...
March 13, 2017: Biomechanics and Modeling in Mechanobiology
https://www.readbyqxmd.com/read/28273951/vein-networks-in-hydrothermal-systems-provide-constraints-for-the-monitoring-of-active-volcanoes
#4
Luigi Cucci, Francesca Di Luccio, Alessandra Esposito, Guido Ventura
Vein networks affect the hydrothermal systems of many volcanoes, and variations in their arrangement may precede hydrothermal and volcanic eruptions. However, the long-term evolution of vein networks is often unknown because data are lacking. We analyze two gypsum-filled vein networks affecting the hydrothermal field of the active Lipari volcanic Island (Italy) to reconstruct the dynamics of the hydrothermal processes. The older network (E1) consists of sub-vertical, N-S striking veins; the younger network (E2) consists of veins without a preferred strike and dip...
December 2017: Scientific Reports
https://www.readbyqxmd.com/read/28264063/acute-death-of-astrocytes-in-blast-exposed-rat-organotypic-hippocampal-slice-cultures
#5
Anna P Miller, Alok S Shah, Brandy V Aperi, Shekar N Kurpad, Brian D Stemper, Aleksandra Glavaski-Joksimovic
Blast traumatic brain injury (bTBI) affects civilians, soldiers, and veterans worldwide and presents significant health concerns. The mechanisms of neurodegeneration following bTBI remain elusive and current therapies are largely ineffective. It is important to better characterize blast-evoked cellular changes and underlying mechanisms in order to develop more effective therapies. In the present study, our group utilized rat organotypic hippocampal slice cultures (OHCs) as an in vitro system to model bTBI. OHCs were exposed to either 138 ± 22 kPa (low) or 273 ± 23 kPa (high) overpressures using an open-ended helium-driven shock tube, or were assigned to sham control group...
2017: PloS One
https://www.readbyqxmd.com/read/28184035/immediate-effects-of-angular-joint-mobilization-a-new-concept-of-joint-mobilization-on-pain-range-of-motion-and-disability-in-a-patient-with-shoulder-adhesive-capsulitis-a-case-report
#6
Younghoon Kim, GyuChang Lee
BACKGROUND Adhesive capsulitis is a common disabling condition, with reviews reporting up to 5.3% of the population being affected, the burden placed upon individuals and healthcare services may therefore be considered substantial. For recovering the normal extensibility of the capsule in individuals with adhesive capsulitis of the shoulder, passive stretching of the capsule through end-range mobilization has been suggested. Recently, the concept of joint mobilization into angular joint mobilization (AJM), which is rotational joint mobilization with joint axis shift, was proposed...
February 10, 2017: American Journal of Case Reports
https://www.readbyqxmd.com/read/28114174/case-report-lightning-induced-pneumomediastinum
#7
Ryan Blumenthal, Gert Saayman
We present the case of a 41-year-old woman who was fatally injured during a witnessed lightning strike event and in whom autopsy revealed the unusual keraunopathological finding of overt pneumomediastinum. The possible pathophysiological mechanism(s) of causation of this phenomenon are discussed, with specific reference also to the "Macklin" effect and the role of blast overpressures associated with lightning strike. It is suggested that the latter may lead to sudden alveolar rupture, with subsequent rapid tracking of air along bronchovascular sheaths in a centripetal manner toward the hilum of the lung and thus into the mediastinum...
January 21, 2017: American Journal of Forensic Medicine and Pathology
https://www.readbyqxmd.com/read/28107370/neuronal-injury-and-glial-changes-are-hallmarks-of-open-field-blast-exposure-in-swine-frontal-lobe
#8
Srinivasu Kallakuri, Alok Desai, Ke Feng, Sharvani Tummala, Tal Saif, Chaoyang Chen, Liying Zhang, John M Cavanaugh, Albert I King
With the rapid increase in the number of blast induced traumatic brain injuries and associated neuropsychological consequences in veterans returning from the operations in Iraq and Afghanistan, the need to better understand the neuropathological sequelae following exposure to an open field blast exposure is still critical. Although a large body of experimental studies have attempted to address these pathological changes using shock tube models of blast injury, studies directed at understanding changes in a gyrencephalic brain exposed to a true open field blast are limited and thus forms the focus of this study...
2017: PloS One
https://www.readbyqxmd.com/read/28103428/aqueous-biphasic-systems-for-the-synthesis-of-formates-by-catalytic-co2-hydrogenation-integrated-reaction-and-catalyst-separation-for-co2-scrubbing-solutions
#9
Martin Scott, Beatriz Blas Molinos, Christian Westhues, Giancarlo Franciò, Walter Leitner
Aqueous biphasic systems were investigated for the production of formate-amine adducts by metal-catalyzed CO2 hydrogenation, including typical scrubbing solutions as feedstocks. Different hydrophobic organic solvents and ionic liquids could be employed as the stationary phase for cis-[Ru(dppm)2 Cl2 ] (dppm=bis-diphenylphosphinomethane) as prototypical catalyst without any modification or tagging of the complex. The amines were found to partition between the two phases depending on their structure, whereas the formate-amine adducts were nearly quantitatively extracted into the aqueous phase, providing a favorable phase behavior for the envisaged integrated reaction/separation sequence...
March 22, 2017: ChemSusChem
https://www.readbyqxmd.com/read/28018003/refuge-alternatives-relief-valve-testing-and-design
#10
T J Lutz, P T Bissert, G T Homce, J A Yonkey
The U.S. National Institute for Occupational Safety and Health (NIOSH) has been researching refuge alternatives (RAs) since 2007. RAs typically have built-in pressure relief valves (PRVs) to prevent the unit from reaching unsafe pressures. The U.S. Mine Safety and Health Administration requires that these valves vent the chamber at a maximum pressure of 1.25 kPa (0.18 psi, 5.0 in. H2O), or as specified by the manufacturer, above mine atmospheric pressure in the RA. To facilitate PRV testing, an instrumented benchtop test fixture was developed using an off-the-shelf centrifugal blower and ductwork...
October 2016: Mining Engineering
https://www.readbyqxmd.com/read/27958428/barrier-layer-induced-channeling-effect-of-as-ion-implantation-in-hgcdte-and-its-influences-on-electrical-properties-of-p-n-junctions
#11
Changzhi Shi, Chun Lin, Yanfeng Wei, Lu Chen, Mingxing Zhu
The HgCdTe layers (x<sub>Cd</sub>∼0.285 and 0.225) were grown by molecular beam epitaxy and liquid phase epitaxy, respectively, followed by the deposition of CdTe and ZnS films as barrier layers by thermal evaporation. Then, the p-on-n photodiodes were fabricated by AS ion implantation, Hg overpressure annealing, passivation, and metallization. The secondary ion mass spectrometry and transmission electron microscopy results indicate that the evaporated CdTe layer with a column structure induces the channeling effect of As ion implantation causing the device performance degradation...
December 1, 2016: Applied Optics
https://www.readbyqxmd.com/read/27923561/neuropathology-and-neurobehavioral-alterations-in-a-rat-model-of-traumatic-brain-injury-to-occupants-of-vehicles-targeted-by-underbody-blasts
#12
Flaubert Tchantchou, William L Fourney, Ulrich H Leiste, Joshua Vaughan, Parisa Rangghran, Adam Puche, Gary Fiskum
Many victims of blast-induced traumatic brain injury are occupants of military vehicles targeted by land mines. Recently improved vehicle designs protect these individuals against blast overpressure, leaving acceleration as the main force potentially responsible for brain injury. We recently developed a unique rat model of under-vehicle blast-induced hyperacceleration where exposure to acceleration as low as 50G force results in histopathological evidence of diffuse axonal injury and astrocyte activation, with no evidence of neuronal cell death...
December 5, 2016: Experimental Neurology
https://www.readbyqxmd.com/read/27909479/atrial-fibrillation-ablation-in-adults-with-repaired-congenital-heart-disease
#13
REVIEW
Marta Acena Md, Ignasi Anguera Md PhD, Paolo D Dallaglio Md, Marcos Rodriguez Md, Xavier Sabaté Md PhD
The incidence of atrial fibrillation (AF) in congenital heart disease (CHD) adults has increased in the past decades due to a longer life expectancy of this population where the subjects are exposed to cardiac overflow, overpressure and structural changes for years. The literature regarding AF ablation in repaired CHD adults emphasizes the importance of intracardiac echocardiography (ICE) to perform the transseptal puncture and the ablation procedure in the left atrium (LA), both effectively and safely. In small case control studies, where the predominant congenital cardiomyopathy was the atrial septal defect, the most common strategy for ablation was antral isolation of the pulmonary veins showing results, at one year follow-up, similar to those in the general population...
February 2016: Journal of Atrial Fibrillation
https://www.readbyqxmd.com/read/27907158/effects-of-exposure-to-blast-overpressure-on-intracranial-pressure-and-blood-brain-barrier-permeability-in-a-rat-model
#14
Usmah Kawoos, Ming Gu, Jason Lankasky, Richard M McCarron, Mikulas Chavko
Exposure to blast overpressure (BOP) activates a cascade of pathological processes including changes in intracranial pressure (ICP) and blood-brain barrier (BBB) permeability resulting in traumatic brain injury (TBI). In this study the effect of single and multiple exposures at two intensities of BOP on changes in ICP and BBB permeability in Sprague-Dawley rats was evaluated. Animals were exposed to a single or three repetitive (separated by 0.5 h) BOPs at 72 kPa or 110 kPa. ICP was monitored continuously via telemetry for 6 days after exposure to BOP...
2016: PloS One
https://www.readbyqxmd.com/read/27907043/thermodynamic-simulation-of-carbonate-cements-water-carbon-dioxide-equilibrium-in-sandstone-for-prediction-of-precipitation-dissolution-of-carbonate-cements
#15
Yiping Duan, Mingshi Feng, Xinyan Zhong, Ruishu Shang, Lihong Huang
Carbonate cements, such as calcite, dolomite, ferrocalcite and ankerite, play important roles in the formation of pores in sandstones: precipitation of carbonate cements modifies pores and inhibits compaction, while dissolution creates secondary pores. This work proposed a precipitation-dissolution model for carbonate cements-CO2-H2O system by means of ion equilibrium concentration ([M2+], M = Ca, Mg, Fe or Mn) with different factors, such as temperature, depth, pH, [Formula: see text], variable rock composition and overpressure...
2016: PloS One
https://www.readbyqxmd.com/read/27885998/bi-ventricular-finite-element-model-of-right-ventricle-overload-in-the-healthy-rat-heart
#16
Fulufhelo Masithulela
BACKGROUND: The recognition of RV overpressure is critical to human life, as this may signify morbidity and mortality. Right ventricle (RV) dysfunction is understood to have an impact on the performance of the left ventricle (LV), but the mechanisms remain poorly understood. It is understood that ventricular compliance has the ability to affect cardiac performance. In this study, a bi-ventricular model of the rat heart was used in preference to other, single-ventricle models. Finite element analysis (FEA) of the bi-ventricular model provides important information on the function of the healthy heart...
November 25, 2016: Bio-medical Materials and Engineering
https://www.readbyqxmd.com/read/27882753/-hemangioblastoma-cerebellum-during-pregnancy
#17
E Bočková, S Pánková
OBJECTIVE: Authors describe a case of woman in the age of 27 years, 36th+0 week of pregnancy, who was hospitalized for headache and vomittin. Magnestic resonance showed the cystic expansion in the left hemisphere of cerebellum with the overpressure in the IV. ventricle and wiht the beginning obstructive hydrocephalus. STUDY TYPE: Case report. SETTING: Hospital of Uherské Hradiště, Inc., Gynecology and Maternity Department. METHOD: Own observation...
2016: Ceská Gynekologie
https://www.readbyqxmd.com/read/27876800/rapid-laccolith-intrusion-driven-by-explosive-volcanic-eruption
#18
Jonathan M Castro, Benoit Cordonnier, C Ian Schipper, Hugh Tuffen, Tobias S Baumann, Yves Feisel
Magmatic intrusions and volcanic eruptions are intimately related phenomena. Shallow magma intrusion builds subsurface reservoirs that are drained by volcanic eruptions. Thus, the long-held view is that intrusions must precede and feed eruptions. Here we show that explosive eruptions can also cause magma intrusion. We provide an account of a rapidly emplaced laccolith during the 2011 rhyolite eruption of Cordón Caulle, Chile. Remote sensing indicates that an intrusion began after eruption onset and caused severe (>200 m) uplift over 1 month...
November 23, 2016: Nature Communications
https://www.readbyqxmd.com/read/27867790/magma-injection-into-a-long-lived-reservoir-to-explain-geodetically-measured-uplift-application-to-the-2007-2014-unrest-episode-at-laguna-del-maule-volcanic-field-chile
#19
Hélène Le Mével, Patricia M Gregg, Kurt L Feigl
Moving beyond the widely used kinematic models for the deformation sources, we present a new dynamic model to describe the process of injecting magma into an existing magma reservoir. To validate this model, we derive an analytical solution and compare its results to those calculated using the Finite Element Method. A Newtonian fluid characterized by its viscosity, density, and overpressure (relative to the lithostatic value) flows through a vertical conduit, intruding into a reservoir embedded in an elastic domain, leading to an increase in reservoir pressure and time-dependent surface deformation...
August 2016: Journal of Geophysical Research. Solid Earth
https://www.readbyqxmd.com/read/27830938/quantitative-electroencephalography-in-a-swine-model-of-blast-induced-brain-injury
#20
Chaoyang Chen, Chengpeng Zhou, John M Cavanaugh, Srinivasu Kallakuri, Alok Desai, Liying Zhang, Albert I King
OBJECTIVE: Electroencephalography (EEG) was used to examine brain activity abnormalities earlier after blast exposure using a swine model to develop a qEEG data analysis protocol. METHODS: Anaesthetized swine were exposed to 420-450 Kpa blast overpressure and survived for 3 days after blast. EEG recordings were performed at 15 minutes before the blast and 15 minutes, 30 minutes, 2 hours and 1, 2 and 3 days post-blast using surface recording electrodes and a Biopac 4-channel data acquisition system...
2017: Brain Injury: [BI]
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