Flame-retardant Cotton Fabric Through Graft Copolymerisation

In an attempt to impart flame-retarding properties to the cotton fabric, post-graftingphosphorylation reactions on grafted cotton fabric were carried out. Photochemical graftcopolymerisation of 4-vinyl pyridine (4-VP) onto cotton fabric using benzophenone asphotosensitiser was carried out. Maximum percentage of grafting Pg, (18.50 %) was obtainedunder optimum  conditions; irradiation time 75 min, 0.5 ml of  benzophenone,  [4-VP]=748.71 x10-2 mole/l and 5 ml of water in the reaction mixture. Aliphatic alcohols of varying chain lengthdecreased percentage of grafting. The pendant pyridine rings of the 4-VP grafted cotton fabricwere converted to pyridinium chloride followed by the reaction with acrylamide to give 2-amido-ethylpyridiniumchloride. This was subjected to phosphorylation reaction with PCl3/petroleumether. The phosphorylated grafted cotton fabric burns only in the presence of flame with veryslow propagation of the flame (only 3.8 cm2) was found to burn of the total area of 147 cm2 with0.12 g of the ash content. Characterisation of gray cotton fabric and modified cotton fabric wascarried out by FTIR, thermogravimetric analysis, crease recovery, and moisture absorption studies

Propagation of Rayleigh waves in non-homogeneous orthotropic elastic media under the effect of magnetic field

The influence of magnetic field on the propagation of Rayleigh waves in an inhomogeneous, orthotropic elastic solid medium has been discussed. The method of separation of variable is used to find the frequency equation of the surface waves. The obtained dispersion equations are in agreement with the classical results when magnetic field and non-homogeneity are neglected   Keywords: Inhomogeneity, Orthotropic elastic solid,   field, Magnetic field

The relationship between patient volume and mortality in NSW major trauma service hospitals

Introduction: Conventional wisdom is that Major Trauma Services (MTS) treating larger volumes of severe trauma patients will have better outcomes than lower volume centres, but recent studies from Europe have questioned this relationship. We aimed to determine if there is a relationship between patient volume and outcome in New South Wales (NSW) MTS hospitals. Materials and Methods: Retrospective observational study using data from the NSW State Trauma Registry from 2010 to 2019 inclusive. Adult patients with Injury Severity Score &gt;15 transported directly to a NSW MTS were included. Outcome measures were mortality at hospital discharge, and intensive care unit and hospital length of stay. Generalised estimating equation models were created to determine the adjusted relationship between patient volume and the main outcome measures. Results: The mean annual patient volume of the MTS ranged from 127.4 to 282.0 patients whilst the observed mortality rates p.a. ranged from 10.4 % to 17.19 %. Multivariate analysis, using low volume MTS as the reference, did not demonstrate a significant difference in mortality between high and low volume MTS (adjusted OR: 1.14 95 % CI: 0.98–1.25, P = 0.087). There was however a significant correlation between volume and length of hospital stay (adjusted β; 0.024, 95 % CI, 0.182 – 1.089, P = 0.006). Conclusions: There was no mortality difference between high and low volume MTS demonstrated. Length of hospital stay significantly increased with increasing volume however.</p

Engineered atherosclerosis-specific zinc ferrite nanocomplex-based MRI contrast agents

BACKGROUND: Cardiovascular diseases are the most prevalent cause of morbidity and mortality affecting millions of people globally. The most effective way to counter cardiovascular complications is early diagnosis and the safest non-invasive diagnostic approach is magnetic resonance imaging (MRI). In this study, superparamagnetic ferrite nanoparticles doped with zinc, exhibiting highly enhanced saturation magnetization and T2 and computed tomography (CT) contrast were synthesized. These nanoparticles have been strategically engineered using bovine lactoferrin (Lf), polyethylene glycol (PEG), and heat shock protein (Hsp)-70 antibody specifically targeting atherosclerosis with potential therapeutic value. The nanocomplexes were further validated in vitro to assess their cytotoxicity, internalization efficiency, effects on cellular proliferation and were assessed for MRI as well as X-ray CT in ex vivo Psammomys obesus rat model. RESULTS: Optimized zinc doped ferrite nanoparticles (Zn0.4Fe2.6O4) with enhanced value of maximum saturation magnetization value on 108.4&nbsp;emu/g and an average diameter of 24&nbsp;&plusmn;&nbsp;2&nbsp;nm were successfully synthesized. Successfully incorporation with bovine lactoferrin, PEG and Hsp-70 (70&nbsp;kDa) antibody led to synthesis of spherical nanocomplexes (size 224.8&nbsp;nm, PDI 0.398). A significantly higher enhancement in T2 (p&nbsp;&lt;&nbsp;0.05, 1.22-fold) and slightly higher T1 (1.09-fold) and CT (1.08-fold) contrast compared to commercial ferrite nanoparticles was observed. The nanocomplexes exhibited effective cellular internalization within 2&nbsp;h in both THP-1 and Jurkat cells. MRI scans of contrast agent injected animal revealed significant arterial narrowing and a significantly higher T2 (p&nbsp;&lt;&nbsp;0.05, 1.71-fold) contrast in adult animals when compared to juvenile and control animals. The excised heart and aorta agar phantoms exhibited weak MRI contrast enhancement in juvenile animal but significant contrast enhancement in adult animal specifically at the aortic arch, descending thoracic aorta and iliac bifurcation region with X-ray CT scan. Histological investigation of the contrast agent injected aorta and heart confirmed site target-specific accumulation at the atherosclerotic aortic arch and descending thoracic aorta of the adult animal with severely damaged intima full of ruptured microatheromas. CONCLUSION: Overall, the study demonstrates the strategic development of nanocomplex based bimodal MRI and CT contrast agents and its validation on Psammomys obesus for atherosclerosis diagnostics

Designing artificial electron transfer pathways in dioxygen-activating metalloenzymes

This thesis describes efforts to introduce new redox reactivity into two classes of dioxygen-activating enzymes. First, I investigated modified cytochrome c peroxidase (CcP). Here, a series of Trp residues were introduced between the heme active site and the surface of the enzyme to serve as a hole transfer wire. The addition of two mutations (A193W and Y229W) introduced new oxidation chemistry to CcP, as evaluated using aromatic substrate oxidation assays. This enzyme is a functional model for lignin peroxidase enzymes and provides a strong foundation for the development of new protein-based oxidation catalysts. Second, we investigated cyanobacterial aldehyde deformylating oxygenase (cAdo) enzymes. Here, we characterized and investigated three Ru-cAdo models. To provide the four electrons required for catalysis, we introduced a Ru-tris(diimine) photosensitizer to solvent exposed cysteine residues. Through NMR and GC-MS, we gained an insight into the catalytic activity of Ru-cAdo. This work highlights the nature of protein based electron transfer and points toward other underlying factors that dictate catalytic efficiency