Effect of Charging Agents on Electrophoretic Deposition of Coarse Titanium Particles

The effects of aluminium (III) chloride (AlCl3), polyethyleneimine (PEI), and poly(diallyldimethylammonium chloride) (PDADMAC)] as charging agents on the electrophoretic deposition (EPD) of coarse (≤20 μm) titanium (Ti) particles onto low-carbon steel cathodic substrates were assessed through microstructural evaluation, deposit yield, electrophoretic mobility measurements, and electrolytic corrosion. Apart from the capacity to achieve high bonding strength and yield, PDADMAC resulted in lower electrolytic corrosion of the anode and introduced less anionic contamination than AlCl3 or PEI. The quality of the EPD deposit in terms of its bonding strength and deposit yield depended on the length scale of the charging agents used in addition to the intrinsic nature of the charging agent (ionic functional groups and sites). Minimisation of the PDADMAC addition level and PDADMAC of lower molecular weight are advantageous for surface hardening purposes owing to lower the carbon content introduced into the deposit yield

Recent advances in management of cryptococcal meningitis: commentary

Cryptococcal meningitis remains a substantial health burden with high morbidity, particularly in developing countries. Antifungal treatment regimens are guided by host factors, severity of illness (including presence of complications), and causative cryptococcal species. Recent clinical studies indicate the need for rapidly fungicidal induction therapy regimens using amphotericin B in combination with flucytosine for optimal outcomes. Maintenance therapy with fluconazole is necessary until recovery of immune function. Cryptococcus gattii meningitis requires prolonged induction/eradication therapy. Prompt control of raised intracranial pressure or hydrocephalus is essential. Clinicians should be vigilant for immune restoration-like features. Adjuvant surgery, corticosteroids, and/or recombinant interferon-gamma may be required for large cryptococcomas, cerebral edema, or refractory infection

Ab Initio Study of Phase Stability in Doped TiO2

Ab-initio density functional theory (DFT) calculations of the relative stability of anatase and rutile polymorphs of TiO2 were carried using all-electron atomic orbitals methods with local density approximation (LDA). The rutile phase exhibited a moderate margin of stability of ~ 3 meV relative to the anatase phase in pristine material. From computational analysis of the formation energies of Si, Al, Fe and F dopants of various charge states across different Fermi level energies in anatase and in rutile, it was found that the cationic dopants are most stable in Ti substitutional lattice positions while formation energy is minimised for F- doping in interstitial positions. All dopants were found to considerably stabilise anatase relative to the rutile phase, suggesting the anatase to rutile phase transformation is inhibited in such systems with the dopants ranked F>Si>Fe>Al in order of anatase stabilisation strength. Al and Fe dopants were found to act as shallow acceptors with charge compensation achieved through the formation of mobile carriers rather than the formation of anion vacancies

Instructor Perspectives: Transitioning from Face-to-Face to an Online or Hybrid Graduate Level Mathematics Education Course

In this paper, the authors reflect on their transitions from teaching a face-to-face mathematics education course for teachers to teaching using an online or hybrid model. As three veteran educators at two different universities, we share lessons learned in constructing and implementing an online or hybrid learning environment. For us, learning to be flexible in how students completed assignments was important. Although we faced many challenges, we looked at the experience through a novice learner’s lens, and recognized that each of us grew from teaching these classes. We found that the instructors’ experiences in working with mathematics specialist candidates in graduate courses are similar to the experiences of instructors teaching undergraduate level courses. Instructors\u27 perceptions are important as universities seek to provide more online and hybrid programs

Limited Activity Of Miltefosine In Murine Models Of Cryptococcal Meningoencephalitis And Disseminated Cryptococcosis

Miltefosine is an alkyl phosphocholine with good oral bioavailability and in vitro activity against Cryptococcus species that has gained interest as an additional agent for cryptococcal infections. Our objective was to further evaluate the in vivo efficacy of miltefosine in experimental in vivo models of cryptococcal meningoencephalitis and disseminated cryptococcosis. Mice were infected intracranially or intravenously with either C. neoformans USC1597 or H99. Miltefosine treatment (1.8 to 45 mg/kg of body weight orally once daily) began at either 1 h or 1 day postinoculation. Fluconazole (10 mg/kg orally twice daily) or amphotericin B deoxycholate (3 mg/kg intraperitoneally once daily) served as positive controls. In our standard models, miltefosine did not result in significant improvements in survival or reductions in fungal burden against either C. neoformans isolate. There was a trend toward improved survival with miltefosine at 7.2 mg/kg against disseminated cryptococcosis with the H99 strain but only at a low infecting inoculum. In contrast, both fluconazole and amphotericin B significantly improved survival in mice with cryptococcal meningoencephalitis and disseminated cryptococcosis due to USC1597. Amphotericin B also improved survival against both cryptococcal infections caused by H99. Combination therapy with miltefosine demonstrated neither synergy nor antagonism in both models. These results demonstrate limited efficacy of miltefosine and suggest caution with the potential use of this agent for the treatment of C. neoformans infections.Pharmac

TiO2 Coating by Gel Oxidation

Gel oxidation is a thermochemical method for the production of an oxide film on a metallic substrate, where the metallic substrate is subjected to gelation by immersion in NaOH solution, followed by oxidation.These films are prepared for biomedical implant coating. Continuous and discontinuous gelled and TiO2 films of submicron thickness were produced on high-purity Ti foil substrates (50μm thickness) by soaking in NaOH solutions (0.5M, 1.0M, 5.0M, and 10.0M). Gelation involved soaking at 60°C for 24 hours. After drying in air for 24 hours, the samples were heated at 300ºC/hour and soaked for 1 hour in air at 400ºC, 600ºC, and 800°C. The compositions, microstructures, and thicknesses of the films were determined using: glancing-angle X-ray diffraction, Raman microspectroscopy, and field emission scanning electron microscopy (FESEM). Raman microspectroscopy revealed the formation of an amorphous sodium titanate gel layer following chemical treatment. As expected, the thickness of the gel layer increased with increasing NaOH concentration. However, the two highest concentrations (5.0M and 10.0M) resulted in a cracking of the gel layer upon drying in air. TiO2 did not crystallize during heating at 400ºC but rutile formed directly upon heating at 600ºC and 800ºC. It can be concluded that the concentration of NaOH and the temperature change the thickness and phases of the titania