Molten Urea Transfer Pump Seal Failures

Case StudiesUrea melt pumps had been a reliability concern since commissioning (1992). Majority of the concerns were related to the failure of mechanical seal. Unexpected failures of seal were encountered during plant startups or during pump changeover. It resulted in a major reliability concern as the continuity of operation of plant had been at stake. Also huge expenses were incurred as damaged seal caused other parts to fail. A typical overhaul costs around USD 10,000. This Case Study highlights the identification of Failure Modes and steps taken to resolve the issues pertaining to seal reliability on this service

Paediatric inflammatory bowel disease: Clinical presentation and disease location

Objective: To determine different clinical presentationsand disease location demarcatedby upper and lower gastrointestinal endoscopyand relevant histopathologyin children diagnosed with inflammatory bowel disease (IBD).Methods: This is 5 years (2010 to 2015) retrospective studyconducted at the Aga Khan University Hospitalenrolling65admitted children between 6 months to 15years from either gender, diagnosed with IBD on clinical presentation, endoscopy and biopsy. Different clinical presentations at the time of diagnosis were noted in different categories of the disease. All patients underwent upper and lower (up to the terminal ileum) endoscopy with multiple punch biopsies and histologic assessment of mucosal specimens. All endoscopies were done by paediatric gastroenterologists at endoscopy suite of the hospital and all specimens were reported by the pathology department. ESPGHAN revised criteria for the diagnosis of inflammatory bowel disease in children and an adolescent was used to standardize our diagnosis. Extent of disease on endoscopy and relevant histopathology of the biopsy samples were noted at the time of diagnosis. Data was summarized using mean, standard deviation, numbers and percentages for different variables.Results: Total 56 children were enrolled according to inclusion criteria. There were 34children (61.53%) diagnosed with ulcerative colitis (UC), 10 patients (16.92%) had Crohn\u27sDisease (CD) and 11 (21.53%) patients were labeled as Indeterminate colitis (IC). Mean age at onset of symptoms was10.03±2.44 and mean age at diagnosis was11.10±2.36. Abdominal pain (80%) and chronic diarrhea (70%) were common symptoms in CD whereas bloody diarrhea (79.41%) and rectal bleeding(64.70%)were common presentation in UC. Patients diagnosed with indeterminate colitis(IC) had similar clinical features as in UC patients. Only 7% patients had some extra-intestinal features in the form of joint pain and/or uveitis. Aspartate aminotransferase level (95.18 ±12.89) was relatively high in patients withCD in comparison with other categories of IBD. Endoscopic findings and relevant histopathology of biopsy samples in UC showed 65% patient had pan-colitis and 13 % with disease restricted to rectum only whereas in CD 70% patient had disease in ileo-colon and only 10 % had involvement of ileum at the time diagnosis.Conclusion: Patients with UC dominated in our cohort. The most common clinical presentation in UC was bloody diarrhea and rectal bleeding and patients with CDhad abdominal pain and chronic diarrhea as predominant clinical features. Extraintestinal features were uncommon in our cohort. In endoscopic findings, pan-colitis was the mostfrequentfinding in UC and ileo-colonwas common location in CD. IC and UC shared common clinical features and disease location on endoscopy

Designing dual inhibitors for the treatment of Alzheimer’s disease as well as Type 2 diabetes mellitus via pharmacoinformatics approach: A step towards better medication for diabetes-associated neurological disorder

Purpose: To design dual inhibitors against Alzheimer’s disease (AD) and type 2 diabetes mellitus (T2DM) via pharmacoinformatics approach.Methods: Dual Drug Candidates (DDC) were designed and explored for their molecular interaction with several AD and T2DM targets. Pterostilbene, a natural anti-T2DM compound was coupled with different cholinesterase inhibitors to design DDC. Orisis Datawarrior online property calculator  tools, Autock 4.2 and Hex 5.1 were used to investigate the potency of all DDC relative to positive controls.Results: The study found that DDC2 (pterostilbene - methylene linker -octa hydro amino phenothiazine), DDC3 (pterostilbene - ethylene linker - N-phthalimide) and DDC5 (pterostilbene - carbonyl linker - 2-methyl-4-aminoquinoline) were the most promising out of all the DDCs. DDC2 showed strong molecular interaction with most of the AD and T2DM targets, including acetylcholinesterase, butrylcholinesterase, β-secretase, receptor for advanced glycation end products and ATP sensitive potassium channel, dipeptidyl peptidase IV and sodium glucose transport protien 2. The findings also revealed the amyloid anti-aggregation potential of DDC.Conclusion: The results show that DDC3 and DDC5 significantly interfer with the primary nucleation process of β amyloid. Thus, DDC2, DDC3 and DDC5 have strong anti-T2DM and anti-AD potential. Keywords: Type 2 Diabetes Mellitus, Alzheimer’s disease, Dual drug candidate, Amyloid-beta, Pterostilben

Targeting NF-κB signaling cascades of glioblastoma by a natural benzophenone, garcinol, via in vitro and molecular docking approaches

Glioblastoma multiforme (GBM) is regarded as the most aggressive form of brain tumor delineated by high cellular heterogeneity; it is resistant to conventional therapeutic regimens. In this study, the anti-cancer potential of garcinol, a naturally derived benzophenone, was assessed against GBM. During the analysis, we observed a reduction in the viability of rat glioblastoma C6 cells at a concentration of 30 µM of the extract (p < 0.001). Exposure to garcinol also induced nuclear fragmentation and condensation, as evidenced by DAPI-stained photomicrographs of C6 cells. The dissipation of mitochondrial membrane potential in a dose-dependent fashion was linked to the activation of caspases. Furthermore, it was observed that garcinol mediated the inhibition of NF-κB (p < 0.001) and decreased the expression of genes associated with cell survival (Bcl-XL, Bcl-2, and survivin) and proliferation (cyclin D1). Moreover, garcinol showed interaction with NF-κB through some important amino acid residues, such as Pro275, Trp258, Glu225, and Gly259 during molecular docking analysis. Comparative analysis with positive control (temozolomide) was also performed. We found that garcinol induced apoptotic cell death via inhibiting NF-κB activity in C6 cells, thus implicating it as a plausible therapeutic agent for GBM

OMAE2009-79347 RELIABILITY ANALYSIS OF COMPLIANT OFFSHORE TOWER UNDER EARTHQUAKE LOADS

ABSTRACT Articulated offshore tower with universal joints in the intermediate level leads to a multi-hinged configuration that can be used for a variety of deep water application. They are flexibly linked to the sea-bed by a universal joint and comply with the oscillatory environmental loads causing large fluctuating seismic demands at the articulating joints. This paper investigates the dynamic response and the reliability assessment of articulated joint (s) of such structures under seismic sea environment. The analysis includes the influence of sea bed shaking on the water-particle kinematics by using Californian earthquakes. The sea state is characterized by DNV version of Pierson Moskowitz spectrum. The dynamic equation of motion is derived using Lagrangian approach, taking into the account the nonlinearities associated with structure and loads. A limit-state function for seismic demand for a universal joint has been derived. Using the derived limit-state function and the responses obtained after time-domain seismic analysis, reliability assessment of the articulated joint has been carried out, using efficient MPPbased probabilistic methods. Design point, important for probabilistic design of articulated joint, located on the failure surface has been worked out. Stochastic sensitivity analysis has been performed to assess the relative importance of design parameter on the stochastic response of articulated joint

Prostate Apoptotic Induction and NFκB Suppression by Dammarolic Acid: Mechanistic Insight into Onco-Therapeutic Action of an Aglycone Asiaticoside

Prostate cancer (PCa) is addressed as the second most common form of onco-threat worldwide and is usually considered as the major cause of mortality in men. Recent times have seen a surge in exploration of plant-derived components for alternative therapeutical interventions against different oncological malignancies. Dammarolic acid or Asiatic acid (AsA) is an aglycone asiaticoside that has been reported for its efficacy in several ailments including cancer. The current study aimed to investigate the anti-proliferative potency of AsA against human prostate cancer PC-3 cells. Purified AsA was diluted and PC-3 cells were exposed to 20, 40, and 80 µM concentration and incubated for 24 h. Post-exposure, PC-3 cells showcased a substantial loss of their viability at 20 µM (p < 0.05), moreover, this reduction in cell viability escalated proportionally with an increase in AsA at concentrations of 40 and 80 µM (p < 0.01; p < 0.001) respectively. AsA-impelled loss of cellular viability was also evident from the acridine orange-stained photomicrographs, which was also used to quantify the viable and apoptotic cells using Image J software. Additionally, quantification of ROS within PC-3 cells also exhibited an increase in DCF-DA-mediated fluorescence intensity post-exposure to AsA in a dose-dependent manner. AsA-induced apoptosis in PC-3 cells was shown to be associated with augmented activity of caspase-3 proportionally to the AsA concentrations. Thus, initially, this exploratory study explicated that AsA treatment leads to anti-proliferative effects in PC-3 cells by enhancing oxidative stress and inciting apoptosis en route to onset of nuclear fragmentation

Molecular docking and dynamic simulation study to explore quercetin as a multi-potent candidate against gliomas

Purpose: To search for novel gliomas targets and their inhibitors using a molecular docking approach. Methods: Quercetin multi-targeting potential was investigated against some of the emerging gliomas targets such as epidermal growth factor receptor (EGFR), ephrin type-A receptor 2 (EphA2), nicotinamide phosphoribosyltransferase (NMRPTase) and plasminogen activator inhibitor-1 (PAI-1). Crucial biochemical interaction of quercetin with these targets were analyzed using molecular docking study. Results: Quercetin interacted strongly via hydrogen bonding with important active sites consisting of amino acid residues of EphA2 and PAI-1, and showed binding energy of -7.44 and -7.38 kcal/mol, respectively. Some crucial active site amino acids involved in the interaction of known EphA2 and PAI-1 inhibitors (Alw-II-41-27 and ACT001) were common in quercetin interactions as well, and both inhibitors as well as quercetin did not violate Lipinski rules. Importantly, the quercetin-EphA2 and quercetin-PAI-1 complexes were stable as minimal fluctuations within the permissible limit were observed during a 20 ns trajectory performed on desmond simulation platform. Conclusion: Despite the fact that quercetin has been studied extensively against various cancer pathways, its transformation from a long-time bench candidate into bedside medications still needs further exploration. Nevertheless, the present predictive biochemical interaction analysis against emerging glioma targets might pave way for the design of novel therapeutic agents based on quercetin scaffolds

Therapeutic Applications of Biostable Silver Nanoparticles Synthesized Using Peel Extract of Benincasa hispida: Antibacterial and Anticancer Activities

The purpose of this study was to fabricate biostable inorganic silver nanoparticles (AgNPs) using fresh peel (aqueous) extract of Benincasa hispida. A fast, robust, and eco-friendly approach was used for the synthesis of AgNPs, where bioactive components of peel extract of B. hispida acted as reducing and stabilizing agents. Synthesized AgNPs were characterized using a UV–Vis spectrophotometer, Fourier-transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), and electron microscopy. The synthesized nanoparticles exhibited maximum absorption at 418 nm under the typical AgNPs surface plasmon resonance band range. They depicted a mean size of 26 ± 2 nm with a spherical shape. Their therapeutic prospective was determined by evaluating their antimicrobial and anticancer potential. The bio-synthesized silver nanoparticles exhibited strong antimicrobial activity with minimum inhibitory concentration (MIC 50) values of 14.5, 8.6, 6.063, and 13.4 μg/mL against Staphylococcus aureus (ATCC 25923), Micrococcus luteus (ATCC 14593), Escherichia coli (ATCC 25922), and Klebsiella pneumonia (ATCC 13883), respectively. The biosynthesized AgNPs showed potent in vitro cytotoxicity against human cervical cancer cell line with a half maximal inhibitory concentration (IC50) value of 0.066 μg/mL; however, no cytotoxic effect was observed on normal human primary osteoblasts cell line. This study explored B. hispida extract and confirmed its effectiveness as a promising source in producing AgNPs that could be employed for several therapeutic applications

Oleuropein as a Potent Compound against Neurological Complications Linked with COVID-19: A Computational Biology Approach

The association of COVID-19 with neurological complications is a well-known fact, and researchers are endeavoring to investigate the mechanistic perspectives behind it. SARS-CoV-2 can bind to Toll-like receptor 4 (TLR-4) that would eventually lead to α-synuclein aggregation in neurons and stimulation of neurodegeneration pathways. Olive leaves have been reported as a promising phytotherapy or co-therapy against COVID-19, and oleuropein is one of the major active components of olive leaves. In the current study, oleuropein was investigated against SARS-CoV-2 target (main protease 3CLpro), TLR-4 and Prolyl Oligopeptidases (POP), to explore oleuropein potency against the neurological complications associated with COVID-19. Docking experiments, docking validation, interaction analysis, and molecular dynamic simulation analysis were performed to provide insight into the binding pattern of oleuropein with the three target proteins. Interaction analysis revealed strong bonding between oleuropein and the active site amino acid residues of the target proteins. Results were further compared with positive control lopinavir (3CLpro), resatorvid (TLR-4), and berberine (POP). Moreover, molecular dynamic simulation was performed using YASARA structure tool, and AMBER14 force field was applied to examine an 100 ns trajectory run. For each target protein-oleuropein complex, RMSD, RoG, and total potential energy were estimated, and 400 snapshots were obtained after each 250 ps. Docking analyses showed binding energy as −7.8, −8.3, and −8.5 kcal/mol for oleuropein-3CLpro, oleuropein-TLR4, and oleuropein-POP interactions, respectively. Importantly, target protein-oleuropein complexes were stable during the 100 ns simulation run. However, an experimental in vitro study of the binding of oleuropein to the purified targets would be necessary to confirm the present study outcomes