Synthesis and Reactions of Aromatic Ethers as Model Compounds for Coal

o-Anisic acid and o-ethoxybenzoic acid were reacted with pyridine hydriodide in pyridine at 115° for 3 days to yield 81% and 18% salicylic acid respectively. o-Anisic acid with KI in pyridine at 115° for 3 days gave 58% salicylic acid while o-anisic acid with LiI·3H2O in pyridine at 85° for 3 days gave 54% salicylic acid. p-Anisic acid and o-phenoxybenzoic acid did not undergo cleavage reactions with pyridine hydriodide under similar conditions. Beta-methylnaphthyl beta-naphthyl ether(I) or alpha-methylnaphthyl alpha-naphthyl ether(II) with pyridine hydriodide in pyridine at 100-115° for 3 days showed no cleavage. Ether I with pyridine hydriodide in the presence of pyridine insoluble Illinois No.6 coal fraction at 115° for 7 days or with added iron salts, such as FeCl2, FeS and FeS2 also showed no cleavage. Recovered ether averaged 98 ± 3%. Since pyridine hydriodide or lithium iodide in pyridine increases the free phenolic content and reduces the apparent molecular weight of pre-asphaltene fraction of Illinois No.6 coal, presumably by ether cleavage, the coal structures reacting are not well-modeled by ethers I and II. It is proposed that oxygen atoms of the reacting ether linkages in the coal fraction are hydrogen bonded by phenol groups either on the same or adjacent aromatic cluster which activates them toward SN2 cleavage by iodide ion under mild conditions

Synthesis and Reactions of Aromatic Ethers as Model Compounds for Coal

o-Anisic acid and o-ethoxybenzoic acid were reacted with pyridine hydriodide in pyridine at 115° for 3 days to yield 81% and 18% salicylic acid respectively. o-Anisic acid with KI in pyridine at 115° for 3 days gave 58% salicylic acid while o-anisic acid with LiI·3H2O in pyridine at 85° for 3 days gave 54% salicylic acid. p-Anisic acid and o-phenoxybenzoic acid did not undergo cleavage reactions with pyridine hydriodide under similar conditions. Beta-methylnaphthyl beta-naphthyl ether(I) or alpha-methylnaphthyl alpha-naphthyl ether(II) with pyridine hydriodide in pyridine at 100-115° for 3 days showed no cleavage. Ether I with pyridine hydriodide in the presence of pyridine insoluble Illinois No.6 coal fraction at 115° for 7 days or with added iron salts, such as FeCl2, FeS and FeS2 also showed no cleavage. Recovered ether averaged 98 ± 3%. Since pyridine hydriodide or lithium iodide in pyridine increases the free phenolic content and reduces the apparent molecular weight of pre-asphaltene fraction of Illinois No.6 coal, presumably by ether cleavage, the coal structures reacting are not well-modeled by ethers I and II. It is proposed that oxygen atoms of the reacting ether linkages in the coal fraction are hydrogen bonded by phenol groups either on the same or adjacent aromatic cluster which activates them toward SN2 cleavage by iodide ion under mild conditions

Nebulised amphotericin B to eradicate Candida colonisation from the respiratory tract in critically ill patients receiving selective digestive decontamination: a cohort study

INTRODUCTION: Colonisation of the lower respiratory tract with Candida species occurs in 25% of mechanically ventilated critically ill patients, and is associated with increased morbidity. Nebulised amphotericin B has been used to eradicate Candida as part of selective decontamination of the digestive tract (SDD) protocols, but its effectiveness is unknown. We aimed to determine the effectiveness of nebulised amphotericin B in eradicating Candida respiratory tract colonisation in patients receiving SDD. METHODS: We included consecutive mechanically ventilated patients during a four-year period. Microbiological screening was performed upon admission and twice weekly thereafter according to a standardised protocol. A colonisation episode was defined as the presence of Candida species in two consecutive sputum samples taken at least one day apart. To correct for time-varying bias and possible confounding, we used a multistate approach and performed time-varying Cox regression with adjustment for age, disease severity, Candida load at baseline and concurrent corticosteroid use. RESULTS: Among 1,819 patients, colonisation with Candida occurred 401 times in 363 patients; 333 of these events were included for analysis. Decolonisation occurred in 51 of 59 episodes (86%) and in 170 of 274 episodes (62%) in patients receiving and not receiving nebulised amphotericin B, respectively. Nebulised amphotericin B was associated with an increased rate of Candida eradication (crude HR 2.0; 95% CI 1.4 to 2.7, adjusted HR 2.2; 95% CI 1.6 to 3.0). Median times to decolonisation were six and nine days, respectively. The incidence rate of ventilator-associated pneumonia, length of stay and mortality did not differ between both groups. CONCLUSIONS: Nebulised amphotericin B reduces the duration of Candida colonisation in the lower respiratory tracts of mechanically ventilated critically ill patients receiving SDD, but data remain lacking that this is associated with a meaningful improvement in clinical outcomes. Until more evidence becomes available, nebulised amphotericin B should not be used routinely as part of the SDD protocol

A Cost-Effective Alternative for Lateral Femoral Wall Perforation in Anterior Cruciate Ligament (ACL) Reconstruction: A Case Report

Lateral femoral wall perforation is a rare intra-operative complication in anterior cruciate ligament (ACL) reconstruction surgery. However, it can be challenging to manage if it occurs. We share our experience on lateral femoral wall perforation managed by a large fragment washer. A 25-year-old man with right ACL injury presented with knee instability despite physiotherapy. Anterior drawer test (ADT) and Lachman test were grade 3, glide on pivot shift was positive. During ACL reconstruction, the lateral femoral wall was perforated. Due to unavailability of the rescue endobutton and budget constraint, we passed the endobutton through a washer and allowed it to sit on the washer over the lateral femoral wall. ADT and Lachman test on post-operative 6, 12 and 24 weeks were grade 1, with a negative pivot shift test. Lysholm knee score improved from 69 pre-operatively to 98 post-operatively. Conventionally, lateral femoral wall perforation can be managed by rescue endobutton, or screw and washer post technique. As this complication is rare, the rescue endobutton may not be available at all times, and the cost of the implant is also another important factor to consider. A washer can be used as an alternative technique to manage lateral femoral wall perforation in ACL reconstruction as it is not only costeffective but also provides stable fixation with good functional outcom

Cultivation of human values among gifted students through the implementation of the spiritual circle module in efforts of humanizing digital learning: a case study

The COVID-19 pandemic has changed the education system with the distinctive rise of e-learning. A sudden shift away from the physical classroom resulted in significant learning loss for students both academically and in their social-emotional progress. Also, the unwillingness of students to engage in virtual classrooms due to low self-esteem, lack of motivation, and self-appreciation has resulted in poor academic achievement. This phenomenon calls for the need to cultivate human values in the virtual classroom that helps to foster character building thus contributing to academic excellence. Thus, in this research, we aim to study the impact of the cultivation of human values in virtual classrooms and how it helps improve the teaching-learning environment through implementing the spiritual circle module. A total of 111 students participated in this study. The study used 21 close-ended questions assessed using a 5-point Likert scale. The study employed descriptive and inferential analyses using SPSS. The analysis revealed that the majority of the students agreed that the spiritual circle module has helped them to engage effectively in the classroom as well as contributed to their personal growth. Also, the Spearman correlation test revealed that there is a strong correlation between the cultivation of human values and student engagement and personal growth respectively. Hence, this study concludes that implementation of the spiritual circle module helps to humanize digital learning by fostering human values which contribute to the improvement of virtual class engagement and personal growth

Applying metaheuristics to feeder bus network design problem

Master'sMASTER OF ENGINEERIN

Selective patterning of ZnO nanorods on silicon substrates using nanoimprint lithography

In this research, nanoimprint lithography (NIL) was used for patterning crystalline zinc oxide (ZnO) nanorods on the silicon substrate. To fabricate nano-patterned ZnO nanorods, patterning of an n-octadecyltrichlorosilane (OTS) self-assembled monolayers (SAMs) on SiO2 substrate was prepared by the polymer mask using NI. The ZnO seed layer was selectively coated only on the hydrophilic SiO2 surface, not on the hydrophobic OTS SAMs surface. The substrate patterned with the ZnO seed layer was treated with the oxygen plasma to oxidize the silicon surface. It was found that the nucleation and initial growth of the crystalline ZnO were proceeded only on the ZnO seed layer, not on the silicon oxide surface. ZnO photoluminescence spectra showed that ZnO nanorods grown from the seed layer treated with plasma showed lower intensity than those untreated with plasma at 378 nm, but higher intensity at 605 nm. It is indicated that the seed layer treated with plasma produced ZnO nanorods that had a more oxygen vacancy than those grown from seed layer untreated with plasma. Since the oxygen vacancies on ZnO nanorods serve as strong binding sites for absorption of various organic and inorganic molecules. Consequently, a nano-patterning of the crystalline ZnO nanorods grown from the seed layer treated with plasma may give the versatile applications for the electronics devices

Hypoxia increases neutrophil-driven matrix destruction after exposure to Mycobacterium tuberculosis.

The importance of neutrophils in the pathology of tuberculosis (TB) has been recently established. We demonstrated that TB lesions in man are hypoxic, but how neutrophils in hypoxia influence lung tissue damage is unknown. We investigated the effect of hypoxia on neutrophil-derived enzymes and tissue destruction in TB. Human neutrophils were stimulated with M. tuberculosis (M.tb) or conditioned media from M.tb-infected monocytes (CoMTB). Neutrophil matrix metalloproteinase-8/-9 and elastase secretion were analysed by luminex array and gelatin zymography, gene expression by qPCR and cell viability by flow cytometry. Matrix destruction was investigated by confocal microscopy and functional assays and neutrophil extracellular traps (NETs) by fluorescence assay. In hypoxia, neutrophil MMP-8 secretion and gene expression were up-regulated by CoMTB. MMP-9 activity and neutrophil elastase (NE) secretion were also increased in hypoxia. Hypoxia inhibited NET formation and both neutrophil apoptosis and necrosis after direct stimulation by M.tb. Hypoxia increased TB-dependent neutrophil-mediated matrix destruction of Type I collagen, gelatin and elastin, the main structural proteins of the human lung. Dimethyloxalylglycin (DMOG), which stabilizes hypoxia-inducible factor-1α, increased neutrophil MMP-8 and -9 secretion. Hypoxia in our cellular model of TB up-regulated pathways that increase neutrophil secretion of MMPs that are implicated in matrix destruction