Clathrate Hydrate-Solid Surface Adhesive Shear Strength Measurements on Carbon Steel Surfaces.

Oil and gas flowlines operating in subsea or cold terrestrial environments face the risk of forming hydrate deposits and plugs. The pressure differential across a hydrate plug can cause the plug to detach from the pipe wall and travel through the pipeline, potentially impacting a bend or inline equipment, causing damage or injury to personnel. Therefore, the hydrate-solid adhesive shear strength is of interest in estimating the maximum allowable differential pressure across a plug during depressurization procedures before the plug is likely to detach from the pipe wall. Quantifying the changes in adhesive shear strength with time and operational conditions is essential in estimating the potential of hydrate deposits to slough from the pipe wall. This work used a force meter with a cylindrical "pig-style" probe mounted to a single axis motorized test stand to measure the force required to dislodge model THF structure II hydrate plugs in carbon steel pipes. Profilometry measurements were used to quantify the mean surface roughness and relative peak frequency of the pipe surfaces. Contact angle measurements were performed of a water droplet on pristine, sanded, and corroded pipe surfaces immersed in nonpolar solvents. The adhesive shear strength of the hydrate plugs was measured for different subcoolings, solid surface roughness, and surface wettabilities. Subcooling was shown to impact the hydrate-solid adhesive shear strength, and a mixed adhesive/cohesive failure mechanism was observed at the highest subcooling tested. The surface roughness and wettability were also shown to influence the hydrate-solid adhesive shear strength, with readily wetting corroded and sanded carbon steel surfaces resulting in greater interface adhesive strength than the pristine carbon steel system. This is likely due to a Wenzel wetting mode at the interface, resulting in a higher ratio of actual to apparent wetted area as well as establishing a mechanical interlocking mechanism.

Development and validation of algorithms to identify patients with chronic kidney disease and related chronic diseases across the Northern Territory, Australia.

BACKGROUND: Electronic health records can be used for population-wide identification and monitoring of disease. The Territory Kidney Care project developed algorithms to identify individuals with chronic kidney disease (CKD) and several commonly comorbid chronic diseases. This study aims to describe the development and validation of our algorithms for CKD, diabetes, hypertension, and cardiovascular disease. A secondary aim of the study was to describe data completeness of the Territory Kidney Care database. METHODS: The Territory Kidney Care database consolidates electronic health records from multiple health services including public hospitals (n = 6) and primary care health services (> 60) across the Northern Territory, Australia. Using the database (n = 48,569) we selected a stratified random sample of patients (n = 288), which included individuals with mild to end-stage CKD. Diagnostic accuracy of the algorithms was tested against blinded manual chart reviews. Data completeness of the database was also described. RESULTS: For CKD defined as CKD stage 1 or higher (eGFR of any level with albuminuria or persistent eGFR < 60 ml/min/1.732, including renal replacement therapy) overall algorithm sensitivity was 93% (95%CI 89 to 96%) and specificity was 73% (95%CI 64 to 82%). For CKD defined as CKD stage 3a or higher (eGFR < 60 ml/min/1.732) algorithm sensitivity and specificity were 93% and 97% respectively. Among the CKD 1 to 5 staging algorithms, the CKD stage 5 algorithm was most accurate with > 99% sensitivity and specificity. For related comorbidities - algorithm sensitivity and specificity results were 75% and 97% for diabetes; 85% and 88% for hypertension; and 79% and 96% for cardiovascular disease. CONCLUSIONS: We developed and validated algorithms to identify CKD and related chronic diseases within electronic health records. Validation results showed that CKD algorithms have a high degree of diagnostic accuracy compared to traditional administrative codes. Our highly accurate algorithms present new opportunities in early kidney disease detection, monitoring, and epidemiological research.

Phosphorylation of ERK and dystrophin S3059 protects against inflammation-associated C2C12 myotube atrophy.

The dystrophin-glycoprotein complex (DGC) is a multiprotein structure required to maintain muscle fiber membrane integrity, transmit force by linking the actin cytoskeleton with the extracellular matrix, and maintain muscle homeostasis. Membrane localization of dystrophin is perturbed in muscles wasting as a consequence of cancer cachexia, tenotomy, and advanced aging, which are all associated with low level, chronic inflammation. Strategies to preserve dystrophin expression at the sarcolemma might therefore combat muscle wasting. Phosphorylation of dystrophin serine 3059 (S3059) enhances the interaction between dystrophin and ß-dystroglycan. To test the contribution of amino acid phosphorylation to muscle fiber size changes, dystrophin constructs with phospho-null and phosphomimetic mutations were transfected into C2C12 muscle cells or AAV-293 cells in the presence or absence of kinase inhibitors/activators to assess effects on myotube diameter and protein function. Overexpression of a dystrophin construct with a phospho-null mutation at S3059 in vitro reduced myotube size in healthy C2C12 cells. Conversely overexpression of a phosphomimetic mutation at S3059 attenuated inflammation-induced myotube atrophy. Increased ERK activation by addition of phorbol myristate acetate (PMA) also reduced inflammation-associated myotube atrophy and increased the interaction between dystrophin and ß-dystroglycan. These findings demonstrate a link between increased ERK activation, dystrophin S3059 phosphorylation, stabilization of the DGC, and the regulation of muscle fiber size. Interventions that increase dystrophin S3059 phosphorylation to promote stronger binding of dystrophin to ß-dystroglycan may have therapeutic potential for attenuation of inflammation-associated muscle wasting.

Defining new barriers to mobilisation in a highly active intensive care unit - have we found the ceiling? An observational study.

BACKGROUND: Mobilisation of intensive care (ICU) patients attenuates ICU-acquired weakness, but the prevalence is low (12-54%). Better understanding of barriers and enablers may inform practice. OBJECTIVES: To identify barriers to mobilisation and factors associated with successful mobilisation in our medical /surgical /trauma ICU where mobilisation is well-established. METHODS: 4-week prospective study of frequency and intensity of mobilisation, clinical factors and barriers (extracted from electronic database). Generalized linear mixed models were used to describe associations between demographics, clinical factors and successful mobilisation. RESULTS: 202 patients accounted for 742 patient days. Patients mobilised on 51% of patient days. Most frequent barriers were drowsiness (18%), haemodynamic/respiratory contraindications (17%), and medical orders (14%). Predictors of successful mobilisation included high Glasgow Coma Score (OR = 1.44, 95%CI=[1.29-1.60]), and male sex (OR = 2.29, 95%CI=[1.40-3.75]) but not age (OR = 1.05, 95%CI=[1.01-1.08]). CONCLUSIONS: Our major barriers (drowsiness, haemodynamic/respiratory contraindications) may be unavoidable, indicating an upper limit of feasible mobilisation therapy in ICU.

A novel system for rapid and cost-effective production of detection and diagnostic reagents of West Nile virus in plants.

The threat of West Nile virus (WNV) epidemics necessitates the development of a technology platform that can produce reagents to support detection and diagnosis rapidly and inexpensively. A plant expression system is attractive for protein production due to its low-cost and high-scalability nature and its ability to make appropriate posttranslational modifications. Here, we investigated the feasibility of using plants to produce two WNV detection and diagnostic reagents to address the current cost and scalability issues. We demonstrated that WNV DIII antigen and E16 monoclonal antibody are rapidly produced at high levels in two plant species and are easily purified. Furthermore, they are effective in identifying WNV and in detecting human IgM response to WNV infection. E16 mAb does not cross-react with other flaviviruses, therefore, is valuable for improving diagnostic accuracy. This study provides a proof of principle for using plants as a robust and economical system to produce diagnostic reagents for arboviruses.