Venous gas embolism as a predictive tool for improving CNS decompression safety

A key process in the pathophysiological steps leading to decompression sickness (DCS) is the formation of inert gas bubbles. The adverse effects of decompression are still not fully understood, but it seems reasonable to suggest that the formation of venous gas emboli (VGE) and their effects on the endothelium may be the central mechanism leading to central nervous system (CNS) damage. Hence, VGE might also have impact on the long-term health effects of diving. In the present review, we highlight the findings from our laboratory related to the hypothesis that VGE formation is the main mechanism behind serious decompression injuries. In recent studies, we have determined the impact of VGE on endothelial function in both laboratory animals and in humans. We observed that the damage to the endothelium due to VGE was dose dependent, and that the amount of VGE can be affected both by aerobic exercise and exogenous nitric oxide (NO) intervention prior to a dive. We observed that NO reduced VGE during decompression, and pharmacological blocking of NO production increased VGE formation following a dive. The importance of micro-nuclei for the formation of VGE and how it can be possible to manipulate the formation of VGE are discussed together with the effects of VGE on the organism. In the last part of the review we introduce our thoughts for the future, and how the enigma of DCS should be approached

Physical Chemistry and Engineering for Adsorptive Gas Storage in Nanoporous Solids

© Springer Nature Singapore Pte Ltd. 2019. Adsorption gas storage is examined from physical chemistry point of view. Net, excess, and absolute adsorption are defined, and their relation to gas storage capacity is examined. Experimental techniques for measuring adsorption isotherms are detailed. Net adsorption particularly stands out among possible thermodynamic choices since it directly shows the advantage of having the adsorbent in a storage cylinder. In addition to storage capacity, engineering implications of Henry’s law constant, heat of adsorption, and multicomponent adsorption are examined with examples to inform material scientists who develop materials

Net Adsorption of Gas/Vapor Mixtures in Microporous Solids

Adsorption thermodynamics is based on Gibbs definition, which transforms the nonuniform interfacial region to a uniform three-phase system including a two-dimensional adsorbed phase on a hyper-surface. Gibbs definition is a pure mathematical construct applicable wherever the hyper-surface is located. On the other hand, physical quantification of adsorption and hence its applications require that the hyper-surface be located. Conceptually, the location of hyper-surface differentiates between so-called absolute, excess, and the recently introduced (Gumma and Talu, Langmuir 2010, 26 (22), 17013-17023) net adsorption thermodynamic frameworks. This article details net adsorption thermodynamic framework for mixtures. In addition, a thermodynamic inconsistency is recognized in the calculation of grand potential (or solid chemical potential) with commonly used implementation of excess adsorption in literature. The inconsistency is shown to have a substantial impact on further thermodynamic calculations such as mixture adsorption predictions for even a simple typical example as oxygen-nitrogen-zeolite SA system at 22 C and moderate pressures. Historically, this inconsistency seems to originate from adopting intuitive concepts for planar surfaces to microporous systems without regard to the differences in the physical nature of these two types of interfaces. Net adsorption framework Circumvents. the inconsistency as well as providing an unequivocal description of adsorption in micropores

Arthroscopy-assisted operative management of tibial plateau fractures

This retrospective review evaluated the results of arthroscopy-assisted surgery for tibial plateau fractures in 45 patients with closed tibial plateau fractures. The fracture involved articular depression in 27 patients in whom lifting and bone grafting with autogenous corticocan-cellous iliac bone graft was required. In 23 patients there were also meniscal lesions, which were treated by partial resection in 16 and repaired in 7. Internal fixation was performed using screws in 36 knees and plate in 10 knees. Radiological results were evaluated according to the Resnic-Niwoyama criteria; mean follow-up was 36 months (range 14-72). There was no intraoperative complication in the series, but postoperatively there were one infection and one loss of correction. Results were satisfactory in 89% of cases, according the Rasmussen criteria. Arthroscopy is thus an excellent and minimally invasive method for assessment and treatment of tibial plateau fractures. The advantages are complete and anatomical reduction in the fractured articular surface and evaluation of other concomitant intra-articular pathology and entails only little additional morbidity, especially compared to arthrotomy