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Thermal Imaging for Arthritis Evaluation in a Small Animal Model
Published in U. Snekhalatha, K. Palani Thanaraj, Kurt Ammer, Artificial Intelligence-Based Infrared Thermal Image Processing and Its Applications, 2023
U. Snekhalatha, K. Palani Thanaraj, Kurt Ammer
Pristane is a non-antigenic chemical substance which induces delayed occurrence of arthritis in rats. CD4+ T-cells, heat shock protein 65, and lymphocytes cause chronic arthritis in rats. The chronic arthritis is onset from 60 to 200 days in the rodent by inducing intra-peritoneal injection of pristane. Hence, this chronic arthritis induced due to PIA resembles RA. The clinical characteristic of PIA involves joint swelling followed by pannus formation in affected joints and infiltration of polymorphonuclear cells. The arthritis development is observed by following a macroscopic scoring system which produces the scoring ranging from 0 to 4 in four limbs. PIA is a kind of autoimmune arthritis model in which the onset of the disease occurs four days after the induction. The authors used DA rats to detect the pre-clinical synovitis and histological findings. 150 μL of pristane (2,6,10,14-tetramethyl pentadecane) was injected at the base of the tail in DA rats. They followed an arthritis-scoring system to evaluate the individual joints in various regions such as wrist, mid-fore paw, ankle, and mid-foot joints according to scores ranging from 0 to 4. They obtained the maximum score at each extremity and total joint per rat as 20 and 80, respectively.
Rheological behavior of crude oil and its dependence on the composition and chemical structure of oil components
Published in Petroleum Science and Technology, 2022
Ekaterina E. Barskaya, Ekaterina S. Okhotnikova, Yulia M. Ganeeva, Tatiana N. Yusupova
The chromatograms of oils are shown in Figure 2. In both Oil 1 (Figure 2a) and Oil 2 (Figure 2b), n-alkanes with the number of carbon atoms from C8 to C34 and isoprenoid alkanes with the number of carbon atoms from C13* to C20* were identified. Isoprenoid alkanes C19* and C20* in the chromatogram are designated as Pr is pristane and Ph is phytane, respectively. In both samples, phytane predominated over pristane. It is believed (Hunt 1996) that this is typical for oils of marine origin associated with organic matter of the sapropel type. Welte and Waples (1973) note the predominance of phytane in oils formed in highly reducing environments in the carbonate strata. The distribution of alkanes in both samples is almost identical. Thus, there is no significant difference in the hydrocarbon composition of alkanes.
Relationship between viscosity and biodegradation of oils from the Eastern Venezuelan Basin
Published in Petroleum Science and Technology, 2022
Liliana López, Guillermo Fernández, René Rojas, Salvador Lo Mónaco
In analyzed oils from Junín area, there is no evidence of oil mixtures (López 2014). But in Socororo field, the presence of pristane and phytane, along with alteration of hopanes and steranes, and the presence of 25-norhopanes, is observed (López, Lo Mónaco, and Volkman 2015). Moreover, Ayacucho oils are characterized by three n-alkanes distribution: (a) a complete set of n-alkanes between n-C15 and n-C35, (b) deplete in n-alkanes with presence of pristane and phytane, and c) depleted in n-alkanes, pristane and phytane. Additionally, all oils from Ayacucho show traces of 25-norhopanes together with alteration of hopanes and steranes (Figure 2). Therefore, in oils from Socororo and Ayacucho, the presence of compounds with different levels of susceptibility to biodegradation indicates that they must be mixtures of oil charges subjected to biodegradation.
Evaluation of the source rock potential of the Unyazah Formation (late Carboniferous-Early Permian) in Dukhan Field, Qatar
Published in Petroleum Science and Technology, 2019
Hamad Al-Saad, Amer Jassim Al-Khafaji, Fadhil N. Sadooni
Gas chromatography fingerprints used in this study to indicate the types of source organic matter input, depositional environment and maturity. A suite of many ratios was applied to assess the redox potential including; Pristane/Phytane (Pr/Ph), Isoprenoids/n-alkanes (Pristane/nC17 and Phytane/nC18) (Figure 5a). These compounds are affected by secondary processes e.g. biodegradation, maturation, and migration. The studied samples have pr/nC17 and ph/nC18 rations ranging from 0.15 to 1.08 and 0.12 to 0.63 respectively. The acyclic isoprenoid (Pr/Ph) ratio is considered as the most common indicator of the redox conditions of the source depositional environment (Didyk et al. 1978). Pr/Ph ratios in the range of 0.20–0.82, and usually increases with thermal maturation. Pr/ph >1 indicates oxic depositional conditions. The pristane/nC17 and phytane/nC18 ratios decrease with thermal maturity and increase with biodegradation because aerobic bacteria usually attack the n-alkanes before the isoprenoids. The samples have a ratios range of 0.14 to 0.63 and from 0.15 to 1.08 respectively.