RESUMO
The increasing extent of greenhouse gas emissions has necessitated the development of techniques for atmospheric carbon dioxide removal and storage. Various techniques are being explored for carbon storage including geological sequestration. The geological sequestration has various avenues such as depleted oil and gas reservoirs, coal-bed methane reservoirs, and mafic and ultramafic rocks. Different trapping mechanisms are in play in these subsurface storage systems. In these sequestration sites, the mafic and ultramafic rocks are best suited for long-term and effective sequestration as they comprise minerals, conducive for chemical alteration, forming stable carbonates. However, these sites often suffer from distinct disadvantages of injectivity issues due to their low permeability and porosity. This study investigates the potential of sequestration in the rock samples obtained from one such site located in India. The rock samples are first characterized using various techniques including X-ray fluorescence, X-ray diffraction, Raman spectroscopy, and field emission scanning electron microscopy (FESEM). The mineralogical characterization shows that the rock sample contains approximately 10% of diopside. The samples were put in the reactor chamber comprising CO2, which were then investigated using FESEM analysis. Additionally, a reservoir block simulation using commercial software was conducted with the representative minerals in the sample to evaluate the CO2 sequestration potential. The simulation result suggests the formation of magnesite which corresponds to a major part of CO2 mineral trapping. The reduced injectivity due to low porosity and permeability in this rock can be addressed using hydraulic fracturing. The geomechanical behavior of the rock sample for hydraulic fracturing is studied using the Brazilian disc test. The Monte Carlo-based uncertainty analysis was conducted using the tensile strength data of the sample. Results suggest that the most likely fracturing pressure is 2100 psi for this rock sample.
RESUMO
Purpose: To describe the long-term outcomes of transcutaneous retrobulbar amphotericin B (TRAMB) in COVID-19-associated mucormycosis. Methods: In total, 18 cases of COVID-19-associated mucormycosis were reviewed. In addition to the recommended treatment protocol, all patients were to be given 3.5 mg/ml/day of TRAMB for five days. Results: Of the 18 patients, 2 presented with stage 3a disease, 13 had stage 3c disease, and 3 patients had central nervous system (CNS) involvement (stage 4a and 4c). In addition to planned retrobulbar doses, five patients were given more while two patients received fewer injections (i.e., <5). At the last mean follow-up of 34.67 (±8.88) weeks, 11 patients were in radiological regression and 4 had stable disease while 2 patients had to undergo exenteration; one mortality was observed because of disease progression. Clinical regression in terms of visual and ptosis improvement was seen in seven and nine patients, respectively. Conclusion: Rhino-orbito-cerebral mucormycosis is a serious condition which warrants an aggressive treatment strategy. In unprecedented situations witnessed recently, TRAMB turned out to be an effective and economical alternative. Though large randomized studies are needed to establish its efficacy, TRAMB still manages to halt progression and salvage the globe in significant number of patients, and hence its use should be encouraged on a case-to-case basis especially in developing countries with limited resources.