UNASSIGNED: Simultaneous bilateral rhegmatogenous retinal detachment (RRD) is a rare and challenging condition in ophthalmology. This case report focuses on a modified pneumatic retinopexy technique, designed to improve treatment outcomes for this difficult condition.
UNASSIGNED: A 59-year-old male presented with decreased visual acuity in his right eye for one week. Examination revealed extensive retinal detachment in the right eye with multiple superior breaks and macula off, separated by approximately 3 clock hours. The left eye exhibited one quartile of retinal detachment with superior breaks and macula on. Bilateral simultaneous PR was performed for retinal repair. In the modified PR procedure, 0.7 ml of low-concentration perfluoropropane and 0.7 ml of filtered pure air were intravitreally injected into the right and left eyes, respectively. A head position maneuver was then employed to sequentially close retinal breaks, followed by laser photocoagulation once the surrounding retina reattached. Two days after gas injection, both retinas were completely reattached. Best corrected visual acuity improved to 0.6 in the right eye and 0.9 in the left eye at the 8-month follow-up.
UNASSIGNED: The innovative modified pneumatic retinopexy technique presented in this case report offers a promising new approach for effectively treating simultaneous bilateral rhegmatogenous retinal detachment.

Among the Enhanced Oil Recovery (EOR) methods, gas-based EOR methods are very popular all over the world. The gas injection has a high ability to increase microscopic sweep efficiency and can increase production efficiency well. However, it should be noted that in addition to all the advantages of these methods, they have disadvantages such as damage due to asphaltene deposition, unfavorable mobility ratio, and reduced efficiency of macroscopic displacement. In this paper, the gas injection process and its challenges were investigated. Then the overcoming methods of these challenges were investigated. To inhibit asphaltene deposition during gas injection, the use of nanoparticles was proposed, which were examined in two categories: liquid-soluble and gas-soluble, and the limitations of each were examined. Various methods were used to overcome the problem of unfavorable mobility ratio and their advantages and disadvantages were discussed. Gas-phase modification has the potential to reduce the challenges and limitations of direct gas injection and significantly increase recovery efficiency. In the first part, the introduction of gas injection and the enhanced oil recovery mechanisms during gas injection were mentioned. In the next part, the challenges of gas injection, which included unfavorable mobility ratio and asphaltene deposition, were investigated. In the third step, gas-phase mobility control methods investigate, emphasizing thickeners, thickening mechanisms, and field applications of mobility control methods. In the last part, to investigate the effect of nanoparticles on asphaltene deposition and reducing the minimum miscible pressure in two main subsets: 1- use of nanoparticles indirectly to prevent asphaltene deposition and reduce surface tension and 2- use of nanoparticles as a direct asphaltene inhibitor and Reduce MMP of the gas phase in crude oil was investigated.

OBJECTIVE: To investigate the outcomes of intravitreal aflibercept and gas injections for submacular hemorrhage (SMH) associated with polypoidal choroidal vasculopathy (PCV).
METHODS: We retrospectively reviewed the medical records of 22 eyes with SMH secondary to PCV that underwent intravitreal aflibercept and 100% perfluoropropane (0.3-0.5 mL) followed by 3-day prone positioning from August 2013 through November 2020. The primary outcome measure was best-corrected visual acuity (BCVA) at 12 months.
RESULTS: The average SMH size was 13.0 ± 9.7 (range, 2.0-37.8) disc diameter. The complete, partial, and no displacement of the SMH was observed in 8 (36%) eyes, 9 (41%) eyes, and 5 (23%) eyes, respectively. The BCVA (logarithm of the minimum angle of resolution) continuously improved significantly from 0.81 ± 0.41 (Snellen equivalent, 20/125) at baseline to 0.48 ± 0.44 (20/60), 0.33 ± 0.39 (20/43), and 0.28 ± 0.45 (20/38), at 3, 6, and 12 months, respectively (P = 0.01 for 3 months; P < 0.001 for 6 and 12 months). The BCVA improved by 3 or more lines in 14 eyes (64%). Two eyes (9%) developed visually significant vitreous hemorrhage, and 1 (5%) eye developed rhegmatogenous retinal detachment; all were successfully treated with vitrectomy. The better BCVA at 12 months tended to be associated with lower height of the SMH at baseline (R2 = 0.171, P = 0.056) and a greater displacement of SMH (R2 = 0.244, P = 0.069). Worse BCVA at 12 months was associated with anticoagulant medication (P < 0.001).
CONCLUSIONS: Intravitreal aflibercept and gas injections are effective and relatively safe for SMH associated with PCV, resulting in significant visual improvement.

OBJECTIVE: This study aimed to report a case of intravitreal gas injection in the supine position for hypotony after intrascleral intraocular lens (IOL) fixation in a patient with Vogt-Koyanagi-Harada (VKH) disease.
METHODS: A 72-year-old Japanese female patient presented with blurred vision in her right eye. Both eyes exhibited a sunset glow fundus due to VKH disease. The right IOL was dislocated; therefore, IOL fixation was performed. The patient\'s hypotony and choroidal effusion persisted postoperatively and her intraocular pressure (IOP) remained 2-4 mmHg despite the performance of two steroid courses. C3F8 (perfluoro pane gas) was injected into the vitreous cavity on postoperative day 35. The patient was instructed to assume a supine position on the third day after injection. At 6 days post-injection, her IOP began to rise; her IOP remained within the normal range until 1 year later.
CONCLUSIONS: This is the first report of successful intravitreal gas injection in a supinated patient with VKH disease to treat postoperative hypotony.

Underwater plasma has been long recognized as a \"green\" alternative to conventional chemicals in the wastewater treatment processes. However, practical application of underwater plasma is still challenging due to insufficient treatment performance. Recently, we proposed a novel process named ACAP utilizing acoustic cavitation in order to stabilize the plasma generation and to enlarge the plasma processing region. This work continues our investigation regarding the ACAP treatment process focusing on effects of gas injection. Experiments were performed using an ultrasonic installation equipped with a specially designed sonotrode (Diam. 48 mm) operated at a frequency of 20 kHz and acoustic power of 120 W. The results revealed that the degradation efficiency of Rhodamine B, which was used as a model wastewater pollutant, remains almost unchangeable in the case of air injection, but it is doubled when argon is injected into the ACAP reactor. It was found that the argon injection enhances the degradation efficiency significantly even without ultrasound irradiation. Results of additional measurements suggest that the effect of argon is attributed to its ability to yield high temperature during cavitation, comparatively good solubility in water and a better ability to reduce the breakdown voltage in water compared to the air case.

Poor solubility of high protein milk powders can be an issue during the production of nutritional formulations, as well as for end-users. One possible way to improve powder solubility is through the creation of vacuoles and pores in the particle structure using high pressure gas injection during spray drying. The aim of this study was to determine whether changes in particle morphology effect physical properties, such as hydration, water sorption, structural strength, glass transition temperature, and α-relaxation temperatures. Four milk protein concentrate powders (MPC, 80%, w/w, protein) were produced, i.e., regular (R) and agglomerated (A) without nitrogen injection and regular (RN) and agglomerated (AN) with nitrogen injection. Electron microscopy confirmed that nitrogen injection increased powder particles\' sphericity and created fractured structures with pores in both regular and agglomerated systems. Environmental scanning electron microscopy (ESEM) showed that nitrogen injection enhanced the moisture uptake and solubility properties of RN and AN as compared with non-nitrogen-injected powders (R and A). In particular, at the final swelling at over 100% relative humidity (RH), R, A, AN, and RN powders showed an increase in particle size of 25, 20, 40, and 97% respectively. The injection of nitrogen gas (NI) did not influence calorimetric glass transition temperature (Tg), which could be expected as there was no change to the powder composition, however, the agglomeration of powders did effect Tg. Interestingly, the creation of porous powder particles by NI did alter the α-relaxation temperatures (up to ~16 °C difference between R and AN powders at 44% RH) and the structural strength (up to ~11 °C difference between R and AN powders at 44% RH). The results of this study provide an in-depth understanding of the changes in the morphology and physical-mechanical properties of nitrogen gas-injected MPC powders.

We use synchrotron X-ray micro-tomography to investigate the displacement dynamics during three-phase-oil, water and gas-flow in a hydrophobic porous medium. We observe a distinct gas invasion pattern, where gas progresses through the pore space in the form of disconnected clusters mediated by double and multiple displacement events. Gas advances in a process we name three-phase Haines jumps, during which gas re-arranges its configuration in the pore space, retracting from some regions to enable the rapid filling of multiple pores. The gas retraction leads to a permanent disconnection of gas ganglia, which do not reconnect as gas injection proceeds. We observe, in situ, the direct displacement of oil and water by gas as well as gas-oil-water double displacement. The use of local in situ measurements and an energy balance approach to determine fluid-fluid contact angles alongside the quantification of capillary pressures and pore occupancy indicate that the wettability order is oil-gas-water from most to least wetting. Furthermore, quantifying the evolution of Minkowski functionals implied well-connected oil and water, while the gas connectivity decreased as gas was broken up into discrete clusters during injection. This work can be used to design CO2 storage, improved oil recovery and microfluidic devices.

OBJECTIVE: To report the outcomes of pneumatic retinopexy (PR) performed as a primary surgical procedure for rhegmatogenous retinal detachment (RRD) or as a secondary procedure for recurrent RRD.
METHODS: We retrospectively analyzed case records of 54 patients (54 eyes) who underwent PR for RRD by injecting 0.3 ml of perfluoropropane (C3F8) in the vitreous cavity and cryopexy to break in the same sitting, followed by positioning.
RESULTS: A total 54 eyes of 54 patients aged between 17 and 84 years (mean - 51.3, median - 53 years) were included in the study. Except five eyes, all had breaks in the superior quadrants. The RRD ranged from 1 quadrant to 4 quadrants. Twenty-eight eyes (51.8%) were phakic and 26 (48.1%) were pseudophakic. The follow-up ranged from 6 to 144 months. In 25 eyes (46.2%), PR was the primary intervention and was successful in 15 (60%) eyes with a significant visual improvement (P = 0.023). Twenty-nine eyes (52.7%) with failed scleral buckle or failed pars plana vitrectomy underwent PR with a success rate of 65.5% and significant visual improvement (P = 0.0017). Progression of proliferative vitreoretinopathy changes (40%) was the most common cause of failure. The success rate was higher in phakic eyes, eyes with attached macula, superior breaks, superior RRD, and RRD limited to 3 quadrants or less.
CONCLUSIONS: PR remains a minimally invasive procedure which can be used primarily or as a salvage procedure in failed surgery with moderately good success rate and minimal complications. One-step procedure reduces patient visits and ensures adequate treatment of the break.

Xanthan gum is widely used as a model fluid for sludge to mimic the rheological behaviour under various conditions including impact of gas injection in sludge. However, there is no study to show the influence of gas injection on rheological properties of xanthan gum specifically at the concentrations at which it is used as a model fluid for sludge with solids concentration above 2%. In this paper, the rheological properties of aqueous xanthan gum solutions at different concentrations were measured over a range of gas injection flow rates. The effect of gas injection on both the flow and viscoelastic behaviour of Xanthan gum (using two different methods - a creep test and a time sweep test) was evaluated. The viscosity curve of different solid concentrations of digested sludge and waste activated sludge were compared with different solid concentrations of Xanthan gum and the results showed that Xanthan gum can mimic the flow behaviour of sludge in flow regime. The results in linear viscoelastic regime showed that increasing gas flow rate increases storage modulus (G\'), indicating an increase in the intermolecular associations within the material structure leading to an increase in material strength and solid behaviour. Similarly, in creep test an increase in the gas flow rate decreased strain%, signifying that the material has become more resistant to flow. Both observed behaviour is opposite to what occurs in sludge under similar conditions. The results of both the creep test and the time sweep test indicated that choosing Xanthan gum aqueous solution as a transparent model fluid for sludge in viscoelastic regime under similar conditions involving gas injection in a concentration range studied is not feasible. However Xanthan gum can be used as a model material for sludge in flow regime; because it shows a similar behaviour to sludge.

Pneumatic vitreolysis (PVL) is the intravitreal injection of a small quantity of expansile gas for the purpose of achieving focal vitreomacular traction (VMT) release for eyes with symptomatic VMT, or inducing VMT release and closure of the macular defect for eyes with a small stage-2 macular hole (MH). Initially, there was limited interest in this technique upon its introduction for clinical treatment in human eyes in 1993. With the advent of optical coherence tomography allowing detailed observation of vitreomacular interface changes and rising importance of medical economics in recent years, there has been increasing interest in PVL, a low-cost procedure for managing symptomatic VMT. The success rates of VMT release in the literature have ranged from 60% to 100% and the rates of closure of small macular holes have ranged from 50% to 80% following PVL. In a recent retrospective consecutive series of 56 eyes in two centers undergoing C3F8 gas injection, Chan and Mein reported an overall success of 86% in VMT release and 60% closure of small macular holes with few adverse events (7% with retinal breaks, retinal detachment, or progression of VMT). Multiple recent studies have shown superior outcome utilizing C3F8 gas compared with SF6 gas for PVL. In conclusion, PVL is a promising, low-cost therapeutic option, with the potential for managing symptomatic focal VMT on a global scale.