Demonstration of the Gas Assisted Gravity Drainage (GAGD) Process in Carbonate Rocks.

The Gas Assisted Gravity Drainage (GAGD) process was developed and patented by Dr. Rao at LSU in the early 2000s. The process involves the use of several existing or new vertical injection wells to inject gas and use the natural segregation of reservoir fluids from the density difference and the gravitational forces to displace the trapped oil and mobilize the oil downwards to be produced by a horizontal producing well. The GAGD process can be implemented as a secondary or tertiary oil recovery method. Several physical model experiments have been conducted to demonstrate the effectiveness of the GAGD process for improving oil recovery. This research study is to expand the existing knowledge of the GAGD process and to apply it for carbonate rocks as more than 60% of world’s oil is held in carbonate reservoirs. In particular, this study focuses on the impact of type of gas injected, injection rate of gas, and the grain size of the porous media. A glass model similar to a Hele-Shaw type model was used for performing the experiments using carbonate rocks as the porous media, water and n-decane for oil. The results from this study show that using nitrogen gas provides slightly higher recovery for the GAGD process in carbonate rocks compared to carbon dioxide. Further, the optimal injection rate is at an intermediate injection rate that doesn’t disturb the stable front which can create an earlier breakthrough at higher injection rates. Finally, the larger grain size shows a significant improvement in overall oil recovery since increasing grain size diameter increases permeability and thus better overall oil recovery is obtained. The oil recovery from this study ranges from 70.9% to 87.7% of OOIP

The burden and characteristics of HIV-infected COVID-19 patients at a tertiary care hospital in sub-Saharan Africa—A retrospective cohort study

Background: After the first case of COVID-19 caused by the novel SARS-CoV-2 virus was discovered in Wuhan, China, in December 2019, the disease spread viciously throughout the world. Little is known about the impact of HIV infection on the clinical outcomes of patients co-infected with SARS-CoV-2. Studying the characteristics and outcomes of COVID-19 among HIV-positive patients is key to characterising the risk of morbidity and mortality of HIV-positive patients from COVID-19. Methods: In this retrospective cohort study, we included patients admitted to Aga Khan University Hospital, Nairobi, with laboratory-confirmed COVID-19 infection and who had consented to HIV screening. We compared the prevalence and characteristics of HIV patients with those of non-HIV patients and described the results for both groups. Results: In our sample of 582 patients, the mean age was 49.2 years (SD = 15.2), with 68% of the sample being men. The cumulative HIV prevalence was 3.7%, and the most common symptoms were cough (58.1%), fever (45.2%), difficulty in breathing (36.8%) and general body malaise (23.9%). The most common comorbidities included hypertension (28.5%), diabetes mellitus (26.1%), and heart disease (4.1%). Most participants (228 or 49.5%) had mild COVID-19, and the mortality rate was 5%. Overall, there were no statistically significant differences in demographic characteristics, clinical characteristics, and outcomes between HIV-positive and HIV-negative patients. Conclusions: There was a 3.7% prevalence of HIV in COVID-19 positive patients. Demographic characteristics and clinical outcomes were similar between the two groups. Future studies should seek to achieve larger samples, include multiple study sites and conduct subgroup analyses based on the immunologic status of HIV-positive patients

Software-based implementation of a frequency hopping two-way radio

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1997.Includes bibliographical references (p. 105-107).by Alok B. Shah.M.Eng

Primary Blast Traumatic Brain Injury in the Rat: Relating Diffusion Tensor Imaging and Behavior

The incidence of traumatic brain injury (TBI) among military personnel is at its highest point in U.S. history. Experimental animal models of blast have provided a wealth of insight into blast injury. The mechanisms of neurotrauma caused by blast, however, are still under debate. Specifically, it is unclear whether the blast shockwave in the absence of head motion is sufficient to induce brain trauma. In this study, the consequences of blast injury were investigated in a rat model of primary blast TBI. Animals were exposed to blast shockwaves with peak reflected overpressures of either 100 or 450 kPa (39 and 110 kPa incident pressure, respectively) and subsequently underwent a battery of behavioral tests. Diffusion tensor imaging (DTI), a promising method to detect blast injury in humans, was performed on fixed brains to detect and visualize the spatial dependence of blast injury. Blast TBI caused significant deficits in memory function as evidenced by the Morris Water Maze, but limited emotional deficits as evidenced by the Open Field Test and Elevated Plus Maze. Fractional anisotropy, a metric derived from DTI, revealed significant brain abnormalities in blast-exposed animals. A significant relationship between memory deficits and brain microstructure was evident in the hippocampus, consistent with its role in memory function. The results provide fundamental insight into the neurological consequences of blast TBI, including the evolution of injury during the sub-acute phase and the spatially dependent pattern of injury. The relationship between memory dysfunction and microstructural brain abnormalities may provide insight into the persistent cognitive difficulties experienced by soldiers exposed to blast neurotrauma and may be important to guide therapeutic and rehabilitative efforts

Recent trends in the pattern and long-term management strategy of patients diagnosed with acute coronary syndrome in India: an observational study

Background: The understanding of demographic patterns and the real-world management practices for patients with acute coronary syndrome (ACS) will facilitate optimizing the management strategies for ACS based on the patient’s clinical profile and the associated risk factors in Indian patients. Hence, this study determined the demographic details and the treatment patterns in Indian patients with ACS.Methods: The RECent trends in the pattern and lOng-term management stRategy of patients Diagnosed with acute coronary syndrome in India (RECORD ACS-2) study was a real-world, retrospective, cross-sectional, observational study conducted at various centres across India between 2021 and 2022. The study outcomes included the demographic profile and therapeutic management in patients with ACS.Results: A total of 9945 patients with a mean age of 59 years were included. The ACS was commonly observed in the age group of 41-70 years with highest incidence in the age group of 51-60 years. The ST-elevation myocardial infarction (STEMI) was most common (53.2%) presentation. Hypertension (37.2%) and dyslipidemia (29.3%) followed by diabetes (21.3%) were the most common comorbidities. Single vessel disease was the most common angiographic feature (58%). Percutaneous coronary intervention was the most preferred management strategy (57%). Ticagrelor was the most preferred loading (68.3%) as well as maintenance (71.2%) P2Y12 inhibitor in ACS patients. Most of the patients (81.8%) had received high intensity statin therapy for the secondary prevention of the disease.Conclusions: The prevalence of ACS was high between 51-60 years of age, more so in males, smokers, and physically less active patients. Associated comorbidities were hypertension, dyslipidemia and diabetes. Incidence of STEMI was high, and more than half of the patients underwent PCI. Ticagrelor was the most preferred P2Y12 inhibitor in ACS patients for loading as well as maintenance therapy

Real-world observational study to capture demographic details of newly diagnosed type 2 diabetes mellitus

Background: To understand the demographic profile of newly diagnosed type 2 diabetes mellitus (T2DM) patients and to evaluate the glycaemic status and initial treatment choices in this subset of T2DM patients.Methods: The ROD-IT-2 study was a real-world, retrospective, cross-sectional, observational study conducted at various centres across India between April 2021 and March 2022. The study outcomes included epidemiology, comorbidities, and management strategies preferred by Indian clinicians in these patients.Results: Data from 29,550 newly diagnosed T2DM patients were analyzed. The mean age of patients was 53.3 years, and majority were males (65%). Majority of patients (63.85%) were aged 40 to 60 years. More than half (53.11%) of the patients were either overweight (36.65%) or obese (16.76%). The mean glycated hemoglobin (HbA1c) was high (8.4%). Most (88.5%) patients had cardio-renal comorbidities. Hypertension was the most common comorbidity (45.7%) followed by dyslipidemia (32.1%). Chronic kidney disease (CKD) was also present in 31.2% patients. In the present study, 9.2% patients presented with microvascular complications at the time of diagnosis. Majority of newly diagnosed patients (79.7%) were treated with combination therapy. In patients who were prescribed dual drug combination therapy, metformin + dipeptidyl peptidase-4 inhibitor (DPP4i) was the preferred combination (42.71%)  followed by metformin + sulfonylurea (31.37%).Conclusions: ROD-IT-2 study showed that mean HbA1c levels in T2DM patients still remain high in our population and cardio-renal comorbidities remain prevalent in newly diagnosed patients. Indian clinicians were found to prefer the combination therapy in newly diagnosed T2DM patients