Reabsorption Of Gases Research Articles

The long-term outcome of eyes with unexplained visual loss after gas tamponade for macula-on retinal detachment.

To analyze the long-term outcome of eyes suffering from unexplained visual loss after gas tamponade for primary macula-sparing rhegmatogenous retinal detachment (RRD). Cross-sectional analysis of all eyes with macula-on RRD experiencing an unexplained loss of vision after gas reabsorption that were treated and followed from 2010 to 2019. The investigational work-up included: best-corrected visual acuity (BCVA), clinical examination, spectral-domain optical coherence tomography (SD-OCT) and automated computerized perimetry. The 9 eyes of the 9 patients were analyzed after 5.9±2.4 years. BCVA improved by 0.54±0.50 logMAR from baseline, achieving a final value of 1.17±0.52 logMAR (∼20/320; p=0.0115). The thicknesses of the macula, of the macular ganglion cells and of the retinal nerve fiber layers were unchanged compared to the baseline, as well as the rate of ellipsoid zone defects (22.2%). The proportion of eyes with microcystoid macular edema (MME) significantly decreased to 44.4% (p=0.0294). Perimetry mean deviation increased from a baseline value of -18.06±2.72 to -17.23±2.29 dB (p=0.0390), with an unchanged pattern standard deviation (p=0.1289). In general, a reduction of the scotomata relative depth from baseline was evident in all eyes. Eyes with macula-on RRD suffering from unexplained visual loss after gas reabsorption, despite disclosing an overall unchanged structural macular morphology, showed a moderate, but significant, visual and perimetric improvement in the long-term.

Human amniotic membrane for failed macular hole. A case of initial unsuccessful outcome that resolved after amniotic membrane exchange.

We described a case of initial unsuccessful outcome of failed macular hole treated with amniotic membrane, that resolved after amniotic membrane exchange and silicone oil injection. a woman affected by a high myopic macular hole that had failed to close after multiple surgeries, had been treated using an amniotic membrane graft and 20% sulfur hexafluoride but, after the gas reabsorption, the macular hole was still open, and the amnioticmembrane. A second surgery with a second amniotic membrane patch and silicone oil was carried out. Two weeks after the procedure the macular hole closed, and the final visual acuity improved from 20/400 to 20/100. In this case, a second surgery, using a new amniotic membrane graft and a longer-lasting endotamponade, closed the hole and improved the visual acuity.

Warming Power of CO2 and H2O: Correlations with Temperature Changes

The dramatic and threatening environmental changes announced for the next decades are the result of models whose main drive factor of climatic changes is the increasing carbon dioxide in the atmosphere. Although taken as a premise, the hypothesis does not have verifiable consistence. The comparison of temperature changes and CO2 changes in the atmosphere is made for a large diversity of conditions, with the same data used to model climate changes. Correlation of historical series of data is the main approach. CO2 changes are closely related to temperature. Warmer seasons or triennial phases are followed by an atmosphere that is rich in CO2, reflecting the gas solving or exsolving from water, and not photosynthesis activity. Interannual correlations between the variables are good. A weak dominance of temperature changes precedence, relative to CO2 changes, indicate that the main effect is the CO2 increase in the atmosphere due to temperature rising. Decreasing temperature is not followed by CO2 decrease, which indicates a different route for the CO2 capture by the oceans, not by gas re-absorption. Monthly changes have no correspondence as would be expected if the warming was an important absorption-radiation effect of the CO2 increase. The anthropogenic wasting of fossil fuel CO2 to the atmosphere shows no relation with the temperature changes even in an annual basis. The absence of immediate relation between CO2 and temperature is evidence that rising its mix ratio in the atmosphere will not imply more absorption and time residence of energy over the Earth surface. This is explained because band absorption is nearly all done with historic CO2 values. Unlike CO2, water vapor in the atmosphere is rising in tune with temperature changes, even in a monthly scale. The rising energy absorption of vapor is reducing the outcoming long wave radiation window and amplifying warming regionally and in a different way around the globe.

Resorption of gas trapped in body cavities: comparison of alveolar and pleural space with inner ear and paranasal sinuses

This paper describes our attempt to devise a short text aimed at improving students' understanding of gas resorption in body cavities. Students are expected to understand the mechanisms behind paranasal sinusitis, otitis media, closed pneumothorax, and atelectasis of collapsed lung tissue, all used as examples. On the basis of the interpretation that during pneumothorax resorption, gas diffuses down pressure gradients into the blood, students are encouraged to calculate tables of pressure gradients for the above-mentioned pathological conditions. After answering a few questions, students need to analyze and eventually accept the following conclusion: in cases of air trapping in collapsible body cavities, all gases will be fully reabsorbed without pain. Air trapping in bone cavities leads only to partial reabsorption of gases and results in subatmospheric intracavity pressure. Partial vacuum causes painful mucosal edema and free fluid secretion.

Quantitative recovery of expired nitrogen and nitrous oxide from venous gas emboli.

It has not been previously established whether venous gas emboli dissolve from pulmonary blood vessels into adjacent airways, or pass as microbubbles directly into the systemic circulation. We reported here the quantitative recovery of embolized gases from the airways, in amounts which substantiate the complete elimination of such gases by dissolution. A computer controlled quadrupole mass spectrometer was used to measure the net expired volumes of N2 or N2O following the injection of 40 ml boluses of these gases into the airways (AW) or right ventricles (RV) of 5 mongrel dogs. Every 20 ms, linearized flow signals were multiplied by gas concentrations, and the products summed for inspired and expired volumes of each breath. Intubated dogs were ventilated with 100% oxygen under Na-pentobarbital and either succinylcholine chloride or pancuronium bromide anesthesia; Swan-Ganz catheters were used for RV injections and for monotoring cardiovascular parameters. The overall mean % volume recoveries were 70.4 for AW-N2O, 68.2 for RV-N2O, 83.7 for AW-N2, and 46.7 for RV-N2. As expected, the AW percent volume recoveries increased with decreasing aqueous solubilities, and represented maximal values obtainable for RV emboli, due to alveolar reabsorption of gases excreted from the pulmonary circulation. Although all RV-N2O could thus be accounted for, RV-N2 recoveries were significantly less than AW-N2. The remaining RV-N2 did not pass as bubbles into the pulmonary veins, but continued to obstruct the pulmonary arterioles, as demonstrated with the use of nitrous oxide challenges in the inspired gas mixture.

The physiology of the swimbladder in the eel, Anguilla vulgaris. II. The reabsorption of gases.

AbstractSteen, J. B. The physiology of the swimbladder in the eel Anguilla vulgaris. II. The reabsorption of gases. Acta physiol. scand. 1963. 58. 138–149. — Gas reabsorption from the reabsorbent swimbladder has been investigated with the micro‐blood analyzer and gas analyzer of Scholander and coworkers. It was shown that O2 moves both from blood to gas and vice versa. The rate of O2 reabsorption depends upon blood flow and the O2 gradient between gas and blood. All the observations support the view that O2 is reabsorbed by diffusion. Blood flow is much increased by anoxia. The reabsorbed O2 is hardly of any respiratory use during O2 shortage of the water, but may be important when the eel is in the air. The increased O2 reabsorption during O2 shortage may also guide the eel to a more O2 rich environment. Fishes have less hydrostatic problems the deeper they live. The reabsorbent bladder of the eel seems to have about the same diffusion characteristics as has the human lung, the functional superiority of the latter beeing due primarily to its favourable surface to volume ratio.