7 research outputs found

    Deep dive into net pay layers: An in-depth study in Abadan Plain, South Iran

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    This study focuses on the intricate process of discerning productive layers within reservoir formations, taking the Sarvak Formation as a primary case. The employed methodology combines geology, comprehensive log interpretations, and petrophysical analyses to facilitate the evaluation of these productive layers. Initially, routine well logs are interpreted to determine key petrophysical parameters such as shale content, porosity, and water saturation. Subsequently, core measurement results are utilized for calibrating these log interpretations. The study further determines cut-off values through a calculated method of 5% cumulative hydrocarbon volume against porosity, shale content, and water saturation. These cut-off values are then applied to the petrophysical results to enhance their reliability. To resolve any inconsistencies or uncertainties in petrophysical evaluation, petrographical analyses, including scanning electron microscope imaging and thin section studies, are employed. The Sarvak Formation is categorized into seven distinct subzones, each thoroughly investigated to ascertain their respective productivity potential. The final results illustrate a substantial heterogeneity within the Sarvak Formation, revealing a range of diagenetic processes including compaction, dissolution, and cementation. Despite this complexity, three subzones are identified as the most productive layers with the maximum net pay, demonstrating the efficacy of the integrated approach

    A case of ankylosing spondylitis presenting with fever of unknown origin diagnosed as aortitis: A case report

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    Key Clinical Message Clinicians should be aware of rare manifestations of AS, while considering a low threshold for screening vascular involvement in an axial SpA/nrxSpA/AS presenting with unexplained fevers and significant constitutional symptoms and elevated markers. Abstract Ankylosing spondylitis (AS) is a chronic inflammatory disease from the spondyloarthritis complex, which usually affects young men and primarily involves sacroiliac joints and the spine. It can also present with non‐joint involvement, such as cardiovascular manifestations. Aortitis is a rare yet critical cardiovascular complication associated with AS, which can lead to life‐threatening outcomes when undiagnosed. Here we report a 34‐year‐old man with intermittent fevers and significant weight loss, myalgia, and arthralgia for 1 year before being referred to our hospital due to undefinable causes despite multiple diagnostic efforts. The patient presented with elevated inflammatory markers and involvement of sacroiliac joints in favor of the AS. A positron emission tomography scan was also done to rule out underlying malignancy, which led to the detection of inflammation in ascending aorta, compatible with aortitis. The patient was treated with nonsteroidal anti‐inflammatory drugs, prednisolone, and infliximab, and his signs and symptoms significantly improved. Our case reports a rare but substantial complication of AS, in a young patient without a history of prolonged disease presenting with unspecific manifestations. The implantation of a thorough examination of AS patients, including cardiac examinations, could contribute to faster and more efficient diagnosis and treatment

    Cryo-EM structures of pentameric autoinducer-2 exporter from Escherichia coli reveal its transport mechanism

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    Bacteria utilize small extracellular molecules to communicate in order to collectively coordinate their behaviors in response to the population density. Autoinducer-2 (AI-2), a universal molecule for both intra- and inter-species communication, is involved in the regulation of biofilm formation, virulence, motility, chemotaxis, and antibiotic resistance. While many studies have been devoted to understanding the biosynthesis and sensing of AI-2, very little information is available on its export. The protein TqsA from Escherichia coli, which belongs to the AI-2 exporter superfamily, has been shown to export AI-2. Here, we report the cryogenic electron microscopic structures of two AI-2 exporters (TqsA and YdiK) from E. coli at 3.35 Å and 2.80 Å resolutions, respectively. Our structures suggest that the AI-2 exporter exists as a homo-pentameric complex. In silico molecular docking and native mass spectrometry experiments were employed to demonstrate the interaction between AI-2 and TqsA, and the results highlight the functional importance of two helical hairpins in substrate binding. We propose that each monomer works as an independent functional unit utilizing an elevator-type transport mechanism

    GlycoVHH : optimal sites for introducing N-glycans on the camelid VHH antibody scaffold and use for macrophage delivery

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    As small and stable high-affinity antigen binders, VHHs boast attractive characteristics both for therapeutic use in various disease indications, and as versatile reagents in research and diagnostics. To further increase the versatility of VHHs, we explored the VHH scaffold in a structure-guided approach to select regions where the introduction of an N-glycosylation N-X-T sequon and its associated glycan should not interfere with protein folding or epitope recognition. We expressed variants of such glycoengineered VHHs in the Pichia pastoris GlycoSwitchM5 strain, allowing us to pinpoint preferred sites at which Man(5)GlcNAc(2)-glycans can be introduced at high site occupancy without affecting antigen binding. A VHH carrying predominantly a Man(5)GlcNAc(2) N-glycan at one of these preferred sites showed highly efficient, glycan-dependent uptake by Mf4/4 macrophages in vitro and by alveolar lung macrophages in vivo, illustrating one potential application of glyco-engineered VHHs: a glycan-based targeting approach for lung macrophage endolysosomal system delivery. The set of optimal artificial VHH N-glycosylation sites identified in this study can serve as a blueprint for targeted glyco-engineering of other VHHs, enabling site-specific functionalization through the rapidly expanding toolbox of synthetic glycobiology

    Famotidine inhibits toll-like receptor 3-mediated inflammatory signaling in SARS-CoV-2 infection

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    Apart from prevention using vaccinations, the management options for COVID-19 remain limited. In retrospective cohort studies, use of famotidine, a specific oral H2 receptor antagonist (antihistamine), has been associated with reduced risk of intubation and death in patients hospitalized with COVID-19. In a case series, nonhospitalized patients with COVID-19 experienced rapid symptom resolution after taking famotidine, but the molecular basis of these observations remains elusive. Here we show using biochemical, cellular, and functional assays that famotidine has no effect on viral replication or viral protease activity. However, famotidine can affect histamine-induced signaling processes in infected Caco2 cells. Specifically, famotidine treatment inhibits histamine-induced expression of Toll-like receptor 3 (TLR3) in SARS-CoV-2 infected cells and can reduce TLR3-dependent signaling processes that culminate in activation of IRF3 and the NF-κB pathway, subsequently controlling antiviral and inflammatory responses. SARS-CoV-2-infected cells treated with famotidine demonstrate reduced expression levels of the inflammatory mediators CCL-2 and IL6, drivers of the cytokine release syndrome that precipitates poor outcome for patients with COVID-19. Given that pharmacokinetic studies indicate that famotidine can reach concentrations in blood that suffice to antagonize histamine H2 receptors expressed in mast cells, neutrophils, and eosinophils, these observations explain how famotidine may contribute to the reduced histamine-induced inflammation and cytokine release, thereby improving the outcome for patients with COVID-19
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