Simulation of Phase Behavior of Crude Oil using Different Equations of State (EOS)

The knowledge and understanding of the phase behavior of crude oil is essential in order to know the changes of fluid behavior with respect to changes of temperature and pressure. Phase behavior of hydrocarbon mixture can be modeled using equation of state (EOS). It offers the advantage of an improved fluid property prediction over conventional black oil model and can be used to predict behavior of the entire composition path and pressure range of the process. The purpose of this study is to investigate the modeling of crude oil phase behavior using four different EOS which are Peng-Robinson (PR), Redlich-Kwong (RK), Soave-Redlich-Kwong (SRK), and Zudkevitch-Joffe-Redlich-Kwong (Z.TRK). The phase behavior of crude oil are examined and compared among three commercial softwares which are PVTi (ECLIPSE), PVTx (TEMPEST) and PVTp (Petroleum Expert). This work investigated the equation that best simulated the experimental Pressure, Volume and Temperature (PVT) data and described the phase behavior of crude oil accurately. Adjustment on the parameters of the chosen EOS, known as tuning or regression, is made to improve the prediction of chosen EOS model to match a variety of experimental fluid data. The work focused on the comparison using different EOS cross checked using three commercial PVT simulation softwares to test for the accuracy. Statistical error analysis along are used to evaluate the accuracy and applicability of the result generated. The results indicated PR EOS is the most accurate EOS in describing the phase behavior of crude oil. It fitted good and provided good representation of PVT experimental data. The tuning of the equation further resulted in greater accuracy. An efficient way of tuning strategy has been developed in this work which emphasis on the critical importance of sequence. It is concluded that the sequence of tuning which started with critical properties followed by BIC and omega properties resulted in greater accuracy

Polycystic kidney disease in a Persian cat

A 6-year-old intact Persian cat was presented for the primary complaint of inappetence and weight loss. Irregular surface of kidneys was palpated during physical examination. Abdominal radiograph findings were indicative of renomegaly. Ultrasonography revealed multiple anaechoic structures within the renal parenchyma. The cortex, medulla and renal pelvis were unable to be differentiated. Both radiographic and ultrasonographic findings were suggestive of polycystic kidney disease. Blood test revealed normochromic, normocytic anaemia with azotaemia whereas urinalys is findings were hypostenuria and proteinuria, consistent of chronic kidney disease due to polycystic kidney. Ultrasound is a useful antemortem diagnostic tool to diagnose polycystic kidney disease in cats

Optimizing patient risk stratification for colonoscopy screening and surveillance of colorectal cancer: The role for linked data

No abstract available for this article

Gelsolin induces colorectal tumor cell invasion via modulation of the urokinase-type plasminogen activator cascade

Gelsolin is a cytoskeletal protein which participates in actin filament dynamics and promotes cell motility and plasticity. Although initially regarded as a tumor suppressor, gelsolin expression in certain tumors correlates with poor prognosis and therapy-resistance. In vitro, gelsolin has anti-apoptotic and pro-migratory functions and is critical for invasion of some types of tumor cells. We found that gelsolin was highly expressed at tumor borders infiltrating into adjacent liver tissues, as examined by immunohistochemistry. Although gelsolin contributes to lamellipodia formation in migrating cells, the mechanisms by which it induces tumor invasion are unclear. Gelsolin’s influence on the invasive activity of colorectal cancer cells was investigated using overexpression and small interfering RNA knockdown. We show that gelsolin is required for invasion of colorectal cancer cells through matrigel. Microarray analysis and quantitative PCR indicate that gelsolin overexpression induces the upregulation of invasion-promoting genes in colorectal cancer cells, including the matrix-degrading urokinase-type plasminogen activator (uPA). Conversely, gelsolin knockdown reduces uPA levels, as well as uPA secretion. The enhanced invasiveness of gelsolin-overexpressing cells was attenuated by treatment with function-blocking antibodies to either uPA or its receptor uPAR, indicating that uPA/uPAR activity is crucial for gelsolin-dependent invasion. In summary, our data reveals novel functions of gelsolin in colorectal tumor cell invasion through its modulation of the uPA/uPAR cascade, with potentially important roles in colorectal tumor dissemination to metastatic sites

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

Background: The EMPA KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population. Methods: EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110. Findings: Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5–2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62–0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16–1·59), representing a 50% (42–58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1). Interpretation: In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease. Funding: Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council

Simulation of Phase Behavior of Crude Oil using Different Equations of State (EOS)

The knowledge and understanding of the phase behavior of crude oil is essential in order to know the changes of fluid behavior with respect to changes of temperature and pressure. Phase behavior of hydrocarbon mixture can be modeled using equation of state (EOS). It offers the advantage of an improved fluid property prediction over conventional black oil model and can be used to predict behavior of the entire composition path and pressure range of the process. The purpose of this study is to investigate the modeling of crude oil phase behavior using four different EOS which are Peng-Robinson (PR), Redlich-Kwong (RK), Soave-Redlich-Kwong (SRK), and Zudkevitch-Joffe-Redlich-Kwong (Z.TRK). The phase behavior of crude oil are examined and compared among three commercial softwares which are PVTi (ECLIPSE), PVTx (TEMPEST) and PVTp (Petroleum Expert). This work investigated the equation that best simulated the experimental Pressure, Volume and Temperature (PVT) data and described the phase behavior of crude oil accurately. Adjustment on the parameters of the chosen EOS, known as tuning or regression, is made to improve the prediction of chosen EOS model to match a variety of experimental fluid data. The work focused on the comparison using different EOS cross checked using three commercial PVT simulation softwares to test for the accuracy. Statistical error analysis along are used to evaluate the accuracy and applicability of the result generated. The results indicated PR EOS is the most accurate EOS in describing the phase behavior of crude oil. It fitted good and provided good representation of PVT experimental data. The tuning of the equation further resulted in greater accuracy. An efficient way of tuning strategy has been developed in this work which emphasis on the critical importance of sequence. It is concluded that the sequence of tuning which started with critical properties followed by BIC and omega properties resulted in greater accuracy